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Fujita S, Gagoski B, Hwang KP, Hagiwara A, Warntjes M, Fukunaga I, Uchida W, Saito Y, Sekine T, Tachibana R, Muroi T, Akatsu T, Kasahara A, Sato R, Ueyama T, Andica C, Kamagata K, Amemiya S, Takao H, Hoshino Y, Tomizawa Y, Yokoyama K, Bilgic B, Hattori N, Abe O, Aoki S. Cross-vendor multiparametric mapping of the human brain using 3D-QALAS: A multicenter and multivendor study. Magn Reson Med 2024; 91:1863-1875. [PMID: 38192263 DOI: 10.1002/mrm.29939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 11/06/2023] [Accepted: 11/06/2023] [Indexed: 01/10/2024]
Abstract
PURPOSE To evaluate a vendor-agnostic multiparametric mapping scheme based on 3D quantification using an interleaved Look-Locker acquisition sequence with a T2 preparation pulse (3D-QALAS) for whole-brain T1, T2, and proton density (PD) mapping. METHODS This prospective, multi-institutional study was conducted between September 2021 and February 2022 using five different 3T systems from four prominent MRI vendors. The accuracy of this technique was evaluated using a standardized MRI system phantom. Intra-scanner repeatability and inter-vendor reproducibility of T1, T2, and PD values were evaluated in 10 healthy volunteers (6 men; mean age ± SD, 28.0 ± 5.6 y) who underwent scan-rescan sessions on each scanner (total scans = 100). To evaluate the feasibility of 3D-QALAS, nine patients with multiple sclerosis (nine women; mean age ± SD, 48.2 ± 11.5 y) underwent imaging examination on two 3T MRI systems from different manufacturers. RESULTS Quantitative maps obtained with 3D-QALAS showed high linearity (R2 = 0.998 and 0.998 for T1 and T2, respectively) with respect to reference measurements. The mean intra-scanner coefficients of variation for each scanner and structure ranged from 0.4% to 2.6%. The mean structure-wise test-retest repeatabilities were 1.6%, 1.1%, and 0.7% for T1, T2, and PD, respectively. Overall, high inter-vendor reproducibility was observed for all parameter maps and all structure measurements, including white matter lesions in patients with multiple sclerosis. CONCLUSION The vendor-agnostic multiparametric mapping technique 3D-QALAS provided reproducible measurements of T1, T2, and PD for human tissues within a typical physiological range using 3T scanners from four different MRI manufacturers.
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Affiliation(s)
- Shohei Fujita
- Department of Radiology, Juntendo University, Tokyo, Japan
- Department of Radiology, The University of Tokyo, Tokyo, Japan
- Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, Massachusetts, USA
- Department of Radiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Borjan Gagoski
- Department of Radiology, Harvard Medical School, Boston, Massachusetts, USA
- Fetal Neonatal Neuroimaging and Developmental Science Center, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Ken-Pin Hwang
- Department of Imaging Physics, MD Anderson Cancer Center, Houston, Texas, USA
| | | | - Marcel Warntjes
- SyntheticMR, Linköping, Sweden
- Center for Medical Imaging Science and Visualization (CMIV), Linköping University, Linköping, Sweden
| | - Issei Fukunaga
- Department of Radiology, Juntendo University, Tokyo, Japan
| | - Wataru Uchida
- Department of Radiology, Juntendo University, Tokyo, Japan
| | - Yuya Saito
- Department of Radiology, Juntendo University, Tokyo, Japan
| | - Towa Sekine
- Department of Radiology, Juntendo University, Tokyo, Japan
| | - Rina Tachibana
- Department of Radiology, Juntendo University, Tokyo, Japan
| | - Tomoya Muroi
- Department of Radiology, Juntendo University, Tokyo, Japan
| | - Toshiya Akatsu
- Department of Radiology, Juntendo University, Tokyo, Japan
| | | | - Ryo Sato
- Department of Radiology, The University of Tokyo, Tokyo, Japan
| | - Tsuyoshi Ueyama
- Department of Radiology, The University of Tokyo, Tokyo, Japan
| | - Christina Andica
- Department of Radiology, Juntendo University, Tokyo, Japan
- Faculty of Health Data Science, Juntendo University, Chiba, Japan
| | - Koji Kamagata
- Department of Radiology, Juntendo University, Tokyo, Japan
| | - Shiori Amemiya
- Department of Radiology, The University of Tokyo, Tokyo, Japan
| | - Hidemasa Takao
- Department of Radiology, The University of Tokyo, Tokyo, Japan
| | | | - Yuji Tomizawa
- Department of Neurology, Juntendo University, Tokyo, Japan
| | | | - Berkin Bilgic
- Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, Massachusetts, USA
- Department of Radiology, Harvard Medical School, Boston, Massachusetts, USA
- Harvard/MIT Health Sciences and Technology, Cambridge, Massachusetts, USA
| | | | - Osamu Abe
- Department of Radiology, The University of Tokyo, Tokyo, Japan
| | - Shigeki Aoki
- Department of Radiology, Juntendo University, Tokyo, Japan
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Mochizuki A, Udagawa A, Miwa Y, Oda Y, Yoneyama K, Okuda C. Blood compatibility of poly(propylene glycol diester) and its water structure observed by differential scanning calorimetry and 2H-nuclear magnetic resonance spectroscopy. J Biomater Sci Polym Ed 2024:1-15. [PMID: 38457333 DOI: 10.1080/09205063.2024.2324505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2023] [Accepted: 11/17/2023] [Indexed: 03/10/2024]
Abstract
Recently, we applied solution 2H-nuclear magnetic resonance spectroscopy (2H NMR) to analyze the water (deuterium oxide, D2O) structure in several biopolymers at ambient temperature. We established that polymers with good blood compatibility (i.e. poly(2-methoxyethyl acrylate) (PMEA)) have water observed at high magnetic fields (upfield) compared with bulk water. Polymers containing poly(propylene glycol) (PPG) or poly(propylene oxide) (PPO) exhibit good compatibility; however, the reason for this remains unclear. In addition, reports on the blood compatibility of PPO/PPG are limited. Therefore, PPG diester (PPGest) was prepared as a model polymer, and its blood compatibility and water structure were investigated. PPGest exhibited excellent blood compatibility. The water in PPGest was observed upfield by 2H NMR, and it was defined as non-freezing water via differential scanning calorimetry. Based on these observations, the relationship between the blood compatibility and water structure of PPGest is discussed by comparing with those of PMEA, and the reason for the good performance of PPG/PPO-based polymers is discussed.
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Affiliation(s)
- Akira Mochizuki
- Department of Bio-Medical Engineering, School of Engineering, Tokai University, Isehara, Japan
| | - Ayaka Udagawa
- Department of Bio-Medical Engineering, School of Engineering, Tokai University, Isehara, Japan
| | | | - Yoshiki Oda
- Technology Joint Management Office of Tokai University, Hiratsuka, Japan
| | - Konatsu Yoneyama
- Department of Bio-Medical Engineering, School of Engineering, Tokai University, Isehara, Japan
| | - Chihiro Okuda
- Department of Bio-Medical Engineering, School of Engineering, Tokai University, Isehara, Japan
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Guo L, Zhang R, Xu Y, Wu W, Zheng Q, Li J, Wang J, Niu J. Predicting the status of lymphovascular space invasion using quantitative parameters from synthetic MRI in cervical squamous cell carcinoma without lymphatic metastasis. Front Oncol 2024; 14:1304793. [PMID: 38380361 PMCID: PMC10876895 DOI: 10.3389/fonc.2024.1304793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Accepted: 01/16/2024] [Indexed: 02/22/2024] Open
Abstract
Purpose To investigate the value of quantitative longitudinal relaxation time (T1), transverse relaxation time (T2), and proton density (PD) maps derived from synthetic magnetic resonance imaging (MRI) for evaluating the status of lymphovascular space invasion (LVSI) in cervical squamous cell carcinoma (CSCC) without lymph node metastasis (LNM). Material and methods Patients with suspected cervical cancer who visited our hospital from May 2020 to March 2023 were collected. All patients underwent preoperative MRI, including routine sequences and synthetic MRI. Patients with pathologically confirmed CSCC without lymphatic metastasis were included in this study. The subjects were divided into negative- and positive-LVSI groups based on the status of LVSI. Quantitative parameters of T1, T2, and PD values derived from synthetic MRI were compared between the two groups using independent samples t-test. Receiver operating characteristic curves were used to determine the diagnostic efficacy of the parameters. Results 59 patients were enrolled in this study and were classified as positive (n = 32) and negative LVSI groups (n = 27). T1 and T2 values showed significant differences in differentiating negative-LVSI from positive-LVSI CSCC (1307.39 ± 122.02 vs. 1193.03 ± 107.86, P<0.0001; 88.42 ± 7.24 vs. 80.99 ± 5.50, P<0.0001, respectively). The area under the curve (AUC) for T1, T2 values and a combination of T1 and T2 values were 0.756, 0.799, 0.834 respectively, and there is no statistically significant difference in the diagnostic efficacy between individual and combined diagnosis of each parameter. Conclusions Quantitative parameters derived from synthetic MRI can be used to evaluate the LVSI status in patients with CSCC without LNM.
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Affiliation(s)
| | | | | | | | | | | | | | - Jinliang Niu
- Department of Radiology, The Second Hospital of Shanxi Medical University, Taiyuan, Shanxi, China
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Cai J, Yuan Y, Xi X, Ukrainczyk N, Pan L, Wang Y, Pan J. Unveiling the Remarkable Potential of Geopolymer-Based Materials by Harnessing Manganese Dioxide Incorporation. Small 2024; 20:e2305360. [PMID: 37786291 DOI: 10.1002/smll.202305360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 09/20/2023] [Indexed: 10/04/2023]
Abstract
Thermoelectric (TE) building materials have the potential to revolutionize sustainable architecture by converting temperature differences into electrical energy. This study introduces geopolymeric TE materials enhanced with manganese dioxide (MnO2 ) as a modifying agent. Calorimetric experiments examine the impact of MnO2 on geopolymerization. Mechanical tests show that adding MnO2 (up to 5% by weight) improves the geopolymer composite's strength, achieving a peak compressive strength of 36.8 MPa. The Seebeck effect of the MnO2 -modified geopolymeric composite is also studied. The inclusion of MnO2 boosts the Seebeck coefficient of the geopolymer, reaching a notable 4273 µV C-1 at a 5% MnO2 dosage. This enhancement is attributed to an increase in the density of states (DOS) and a reduction in relaxation time. However, excessive MnO2 or high alkali levels may adversely affect the Seebeck coefficient by lengthening the relaxation time.
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Affiliation(s)
- Jingming Cai
- Key Laboratory of Concrete and Prestressed Concrete Structures of Ministry of Education, Southeast University, Nanjing, 211102, China
| | - Yujin Yuan
- Key Laboratory of Concrete and Prestressed Concrete Structures of Ministry of Education, Southeast University, Nanjing, 211102, China
| | - Xiang Xi
- College of Mechanics and Materials, Hohai University, Nanjing, 211100, China
| | - Neven Ukrainczyk
- Institute of Construction and Building Materials, Technical University of Darmstadt, Franziska-Braun-Str 7, 64287, Darmstadt, Germany
| | - Lin Pan
- College of Materials Science and Engineering, Nanjing Tech University, Nanjing, 210009, China
| | - Yifeng Wang
- College of Materials Science and Engineering, Nanjing Tech University, Nanjing, 210009, China
| | - Jinlong Pan
- Key Laboratory of Concrete and Prestressed Concrete Structures of Ministry of Education, Southeast University, Nanjing, 211102, China
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Gomasu S, Saha S, Ghosh S, Bhowmik R, Das D. High Energy Density Achieved in Novel Lead-Free BiFeO 3-CaTiO 3 Ferroelectric Ceramics for High-Temperature Energy Storage Applications. ACS Appl Mater Interfaces 2024; 16:3654-3664. [PMID: 38211324 DOI: 10.1021/acsami.3c13860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2024]
Abstract
The development of high-performance electrostatic energy storage dielectrics is essential for various applications such as pulsed-power technologies, electric vehicles (EVs), electronic devices, and the high-temperature aviation sector. However, the usage of lead as a crucial component in conventional high-performance dielectric materials has raised severe environmental concerns. As a result of this, there is an urgent need to explore lead-free alternatives. Ferroelectric ceramics offer high energy density but lack stability at high temperatures. Here we present a lead-free (1 - x)BiFeO3-xCaTiO3 (x = 0.6, 0.7, and 0.8; BFO-CTO) ceramic capacitor with low dielectric loss, high thermal stability, and high energy density up to ∼200 °C. The introduction of CTO (x = 0.7) to the BFO matrix triggers a transition from the normal ferroelectrics to the relaxor ferroelectrics state, resulting in a high recoverable energy density of 1.18 J cm-3 at 190 °C with an ultrafast dielectric relaxation time of 44 μs. These results offer a promising, environmentally friendly, high-capacity ceramic capacitor material for high-frequency and high-temperature applications.
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Affiliation(s)
- Sreenu Gomasu
- School of Engineering Sciences and Technology, University of Hyderabad, Hyderabad 500046, India
| | - Subhadeep Saha
- School of Engineering Sciences and Technology, University of Hyderabad, Hyderabad 500046, India
| | - Siddhartha Ghosh
- Department of Physics, SRM University─Andhra Pradesh, Amaravati, Andhra Pradesh 522502, India
| | - Rabindranath Bhowmik
- Department of Physics, Pondicherry University, R. V. Nagar, Kalapet, Pondicherry 605014, India
| | - Dibakar Das
- School of Engineering Sciences and Technology, University of Hyderabad, Hyderabad 500046, India
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Sirucek L, Zoelch N, Schweinhardt P. Improving magnetic resonance spectroscopy in the brainstem periaqueductal gray using spectral registration. Magn Reson Med 2024; 91:28-38. [PMID: 37800387 DOI: 10.1002/mrm.29832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 07/08/2023] [Accepted: 07/31/2023] [Indexed: 10/07/2023]
Abstract
PURPOSE Functional understanding of the periaqueductal gray (PAG), a clinically relevant brainstem region, can be advanced using 1 H-MRS. However, the PAG's small size and high levels of physiological noise are methodologically challenging. This study aimed to (1) improve 1 H-MRS quality in the PAG using spectral registration for frequency and phase error correction; (2) investigate whether spectral registration is particularly useful in cases of greater head motion; and (3) examine metabolite quantification using literature-based or individual-based water relaxation times. METHODS Spectra were acquired in 33 healthy volunteers (50.1 years, SD = 17.19, 18 females) on a 3 T Philipps MR system using a point-resolved spectroscopy (PRESS) sequence optimized with very selective saturation pulses (OVERPRESS) and voxel-based flip angle calibration (effective volume of interest size: 8.8 × 10.2 × 12.2 mm3 ). Spectra were fitted using LCModel and SNR, NAA peak linewidths and Cramér-Rao lower bounds (CRLBs) were measured after spectral registration and after minimal frequency alignment. RESULTS Spectral registration improved SNR by 5% (p = 0.026, median value post-correction: 18.0) and spectral linewidth by 23% (p < 0.001, 4.3 Hz), and reduced the metabolites' CRLBs by 1% to 15% (p < 0.026). Correlational analyses revealed smaller SNR improvements with greater head motion (p = 0.010) recorded using a markerless motion tracking system. Higher metabolite concentrations were detected using individual-based compared to literature-based water relaxation times (p < 0.001). CONCLUSION This study demonstrates high-quality 1 H-MRS acquisition in the PAG using spectral registration. This shows promise for future 1 H-MRS studies in the PAG and possibly other clinically relevant brain regions with similar methodological challenges.
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Affiliation(s)
- Laura Sirucek
- Department of Chiropractic Medicine, Integrative Spinal Research Group, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
| | - Niklaus Zoelch
- Department of Forensic Medicine and Imaging, Institute of Forensic Medicine, University of Zurich, Zurich, Switzerland
- Department of Psychiatry, Psychotherapy, and Psychosomatics, Psychiatric University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Petra Schweinhardt
- Department of Chiropractic Medicine, Integrative Spinal Research Group, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
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Amemiya T, Yokosawa S, Taniguchi Y, Sato R, Soutome Y, Ochi H, Shirai T. Simultaneous Arterial and Venous Imaging Using 3D Quantitative Parameter Mapping. Magn Reson Med Sci 2024; 23:56-65. [PMID: 36543227 PMCID: PMC10838721 DOI: 10.2463/mrms.mp.2021-0170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 10/10/2022] [Indexed: 01/05/2024] Open
Abstract
PURPOSE To increase the number of images that can be acquired in MR examinations using quantitative parameters, we developed a method for obtaining arterial and venous images with mapping of proton density (PD), RF inhomogeneity (B1), longitudinal relaxation time (T1), apparent transverse relaxation time (T2*), and magnetic susceptibility through calculation, all with the same spatial resolution. METHODS The proposed method uses partially RF-spoiled gradient echo sequences to obtain 3D images of a subject with multiple scan parameters. The PD, B1, T1, T2*, and magnetic susceptibility maps are estimated using the quantification method we previously developed. Arterial images are obtained by adding images using optimized weights to emphasize the arteries. A morphology filter is used to obtain venous images from the magnetic susceptibility maps. For evaluation, images obtained from four out of five healthy volunteers were used to optimize the weights used in the arterial-image calculation, and the optimized weights were applied to the images from the fifth volunteer to obtain an arterial image. Arterial images of the five volunteers were calculated using the leave-one-out method, and the contrast between the arterial and background regions defined using the reference time-of-flight (TOF) method was evaluated using the area under the receiver operation characteristic curve (AUC). The contrast between venous and background regions defined by a reference quantitative susceptibility mapping (QSM) method was also evaluated for the venous image. RESULTS The AUC to discriminate blood vessels and background using the proposed method was 0.905 for the arterial image and 0.920 for the venous image. CONCLUSION The results indicate that the arterial images and venous images have high signal intensity at the same region as determined from the reference TOF and QSM methods, demonstrating the possibility of acquiring vasculature images with quantitative parameter mapping through calculation in an integrated manner.
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Affiliation(s)
- Tomoki Amemiya
- Innovative Technology Laboratory, FUJIFILM Healthcare Corporation, Kokubunji, Tokyo, Japan
| | - Suguru Yokosawa
- Innovative Technology Laboratory, FUJIFILM Healthcare Corporation, Kokubunji, Tokyo, Japan
| | - Yo Taniguchi
- Innovative Technology Laboratory, FUJIFILM Healthcare Corporation, Kokubunji, Tokyo, Japan
| | - Ryota Sato
- Innovative Technology Laboratory, FUJIFILM Healthcare Corporation, Kokubunji, Tokyo, Japan
| | - Yoshihisa Soutome
- Innovative Technology Laboratory, FUJIFILM Healthcare Corporation, Kokubunji, Tokyo, Japan
| | - Hisaaki Ochi
- Innovative Technology Laboratory, FUJIFILM Healthcare Corporation, Kokubunji, Tokyo, Japan
| | - Toru Shirai
- Innovative Technology Laboratory, FUJIFILM Healthcare Corporation, Kokubunji, Tokyo, Japan
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Taniguchi Y, Yokosawa S, Shirai T, Sato R, Amemiya T, Soutome Y, Bito Y, Ochi H. Three-dimensional Multi-parameter Mapping of Relaxation Times and Susceptibility Using Partially RF-spoiled Gradient Echo. Magn Reson Med Sci 2023; 22:459-468. [PMID: 35908880 PMCID: PMC10552665 DOI: 10.2463/mrms.mp.2021-0045] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 05/27/2022] [Indexed: 11/09/2022] Open
Abstract
PURPOSE MR parameter mapping is a technique that obtains distributions of parameters such as relaxation time and proton density (PD) and is starting to be used for disease quantification in clinical diagnoses. Quantitative susceptibility mapping is also promising for the early diagnosis of brain disorders such as degenerative neurological disorders. Therefore, we developed an MR quantitative parameter mapping (QPM) method to map four tissue-related parameters (T1, T2*, PD, and susceptibility) and B1 simultaneously by using a 3D partially RF-spoiled gradient echo (pRSGE). We verified the accuracy and repeatability of QPM in phantom and volunteer experiments. METHODS Tissue-related parameters are estimated by varying four scan parameters of the 3D pRSGE: flip angle, RF-pulse phase increment, TR and TE, performing multiple image scans, and finding a least-squares fit for an intensity function (which expresses the relationship between the scan parameters and intensity values). The intensity function is analytically complex, but by using a Bloch simulation to create it numerically, the least-squares fitting can be used to estimate the quantitative values. This has the advantage of shortening the image-reconstruction processing time needed to estimate the quantitative values than with methods using pattern matching. RESULTS A 1.1-mm isotropic resolution scan covering the whole brain was completed with a scan time of approximately 12 minutes, and the reconstruction time using a GPU was approximately 1 minute. The phantom experiments confirmed that both the accuracy and repeatability of the quantitative values were high. The volunteer scans also confirmed that the accuracy of the quantitative values was comparable to that of conventional methods. CONCLUSION The proposed QPM method can map T1, T2*, PD, susceptibility, and B1 simultaneously within a scan time that can be applied to human subjects.
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Affiliation(s)
- Yo Taniguchi
- Innovative Technology Laboratory, FUJIFILM Healthcare Corporation, Tokyo, Japan
| | - Suguru Yokosawa
- Innovative Technology Laboratory, FUJIFILM Healthcare Corporation, Tokyo, Japan
| | - Toru Shirai
- Innovative Technology Laboratory, FUJIFILM Healthcare Corporation, Tokyo, Japan
| | - Ryota Sato
- Innovative Technology Laboratory, FUJIFILM Healthcare Corporation, Tokyo, Japan
| | - Tomoki Amemiya
- Innovative Technology Laboratory, FUJIFILM Healthcare Corporation, Tokyo, Japan
| | - Yoshihisa Soutome
- Innovative Technology Laboratory, FUJIFILM Healthcare Corporation, Tokyo, Japan
| | | | - Hisaaki Ochi
- Innovative Technology Laboratory, FUJIFILM Healthcare Corporation, Tokyo, Japan
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Fukunaga K, Fujiwara Y, Enzaki M, Komi M, Hirai T, Azuma M. [Usefulness of Voxel-Based Quantification (VBQ) Smoothing in Relaxation Time Mapping]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2023; 79:913-922. [PMID: 37544734 DOI: 10.6009/jjrt.2023-1378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
PURPOSE Voxel-based quantification (VBQ) smoothing is a technique used to smooth quantitative parametric maps in the Montreal Neurological Institute standard space. Although VBQ smoothing could suppress changes in quantitative values at tissue boundaries, its effectiveness on relaxation time (T1 and T2 values and proton density PD) maps has not been investigated. The purpose of this study was to clarify the usefulness of VBQ smoothing in relaxation time mapping. METHOD T1 and T2 values and PD maps of the brains of 20 healthy participants were obtained using a two-dimensional multi-dynamic multi-echo sequence. VBQ and Gaussian smoothing were applied to the relaxation time maps by varying the kernel size by 1 mm from 1 to 6 mm. Changes in relaxation time before and after VBQ and Gaussian smoothing for the putamen, caudate nucleus, substantia nigra, and corpus callosum on the relaxation time maps were evaluated. RESULT The changes in relaxation time after VBQ smoothing application were smaller than those in that after Gaussian smoothing application. Although the differences in the relaxation time for all tissues before and after VBQ and Gaussian smoothing applications increased with increasing kernel size for all relaxation times for both methods, the changes in the relaxation time for VBQ smoothing were smaller than those in that for Gaussian smoothing. CONCLUSION VBQ smoothing can suppress the change in the relaxation time on the boundary of the tissue and is thus a useful smoothing technique in relaxation time mapping.
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Affiliation(s)
- Kota Fukunaga
- Graduate School of Health Sciences, Kumamoto University
| | - Yasuhiro Fujiwara
- Department of Medical Image Sciences, Faculty of Life Sciences, Kumamoto University
| | | | | | - Toshinori Hirai
- Department of Diagnostic Radiology, Faculty of Medicine, Kumamoto University
| | - Minako Azuma
- Department of Radiology, Faculty of Medicine, University of Miyazaki
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Bouhsina N, Tur L, Hardel JB, Madec S, Rouleau D, Etienne F, Guicheux J, Clouet J, Fusellier M. Variable flip angle T1 mapping and multi-echo T2 and T2* mapping magnetic resonance imaging sequences allow quantitative assessment of canine lumbar disc degeneration. Vet Radiol Ultrasound 2023; 64:864-872. [PMID: 37549962 DOI: 10.1111/vru.13288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 07/20/2023] [Accepted: 07/21/2023] [Indexed: 08/09/2023] Open
Abstract
Magnetic resonance imaging is the gold standard for diagnosing intervertebral disc (IVD) degeneration in dogs. However, published methods for quantifying severity or progression of IVD degeneration are currently limited. Mapping MRI sequences are used in humans for quantifying IVD degeneration but have rarely been applied in dogs. The objective of this prospective, method comparison study was to evaluate variable flip angle T1 mapping and multiecho T2 and T2* mapping as methods for quantifying canine lumbar IVD degeneration in twenty canine patients without clinical signs of spinal disease. Ventral and dorsal lumbar IVD widths were measured on radiographs, and lumbar IVDs were assigned a qualitative Pfirrmann grade based on standard T2-weighted sequences. T1, T2, and T2* relaxation times of the nucleus pulposus (NP) were measured on corresponding maps using manual-drawn ROIs. Strong intra- and interrater agreements were found (P < 0.01) for NP relaxation times. Radiographic IVD widths and T1, T2, and T2* mapping NP relaxation times were negatively correlated with Pfirrmann grading (P < 0.01). Significant differences in T1 NP relaxation times were found between Pfirrmann grade I and the other grades (P < 0.01). Significant differences in T2 and T2* NP relaxation times were found between grade I and the other grades and between grades II and III (P < 0.01). Findings indicated that T1, T2, and T2* MRI mapping sequences are feasible in dogs. Measured NP relaxation times were repeatable and decreased when Pfirrmann grades increased. These methods may be useful for quantifying the effects of regenerative treatment interventions in future longitudinal studies.
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Affiliation(s)
- Nora Bouhsina
- Nantes Université, Oniris, CHU Nantes, INSERM, Regenerative Medicine and Skeleton, RMeS, Nantes, France
- Department of Diagnostic Imaging, CRIP, ONIRIS, College of Veterinary Medicine, Food Science and Engineering, Nantes, France
| | - Léa Tur
- Department of Diagnostic Imaging, CRIP, ONIRIS, College of Veterinary Medicine, Food Science and Engineering, Nantes, France
| | - Jean-Baptiste Hardel
- Department of Diagnostic Imaging, CRIP, ONIRIS, College of Veterinary Medicine, Food Science and Engineering, Nantes, France
| | - Stéphane Madec
- Nantes Université, Oniris, CHU Nantes, INSERM, Regenerative Medicine and Skeleton, RMeS, Nantes, France
- Department of Diagnostic Imaging, CRIP, ONIRIS, College of Veterinary Medicine, Food Science and Engineering, Nantes, France
| | - Dominique Rouleau
- Nantes Université, Oniris, CHU Nantes, INSERM, Regenerative Medicine and Skeleton, RMeS, Nantes, France
- Department of Diagnostic Imaging, CRIP, ONIRIS, College of Veterinary Medicine, Food Science and Engineering, Nantes, France
| | - Floriane Etienne
- Nantes Université, Oniris, CHU Nantes, INSERM, Regenerative Medicine and Skeleton, RMeS, Nantes, France
- Department of Diagnostic Imaging, CRIP, ONIRIS, College of Veterinary Medicine, Food Science and Engineering, Nantes, France
| | - Jérôme Guicheux
- Nantes Université, Oniris, CHU Nantes, INSERM, Regenerative Medicine and Skeleton, RMeS, Nantes, France
| | - Johann Clouet
- Nantes Université, Oniris, CHU Nantes, INSERM, Regenerative Medicine and Skeleton, RMeS, Nantes, France
| | - Marion Fusellier
- Nantes Université, Oniris, CHU Nantes, INSERM, Regenerative Medicine and Skeleton, RMeS, Nantes, France
- Department of Diagnostic Imaging, CRIP, ONIRIS, College of Veterinary Medicine, Food Science and Engineering, Nantes, France
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11
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Ye F, Kiani F, Huang Y, Xia Q. Diffusive Memristors with Uniform and Tunable Relaxation Time for Spike Generation in Event-Based Pattern Recognition. Adv Mater 2023; 35:e2204778. [PMID: 36036786 DOI: 10.1002/adma.202204778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 08/05/2022] [Indexed: 06/15/2023]
Abstract
A diffusive memristor is a promising building block for brain-inspired computing hardware. However, the randomness in the device relaxation dynamics limits the wide-range adoption of diffusive memristors in large arrays. In this work, the device stack is engineered to achieve a much-improved uniformity in the relaxation time (standard deviation σ reduced from ≈12 to ≈0.32 ms). The memristor is further connected with a resistor or a capacitor and the relaxation time is tuned between 1.13 µs and 1.25 ms, ranging from three orders of magnitude. The hierarchy of time surfaces (HOTS) algorithm, to utilize the tunable and uniform relaxation behavior for spike generation, is implemented. An accuracy of 77.3% is achieved in recognizing moving objects in the neuromorphic MNIST (N-MNIST) dataset. The work paves the way for building emerging neuromorphic computing hardware systems with ultralow power consumption.
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Affiliation(s)
- Fan Ye
- Department of Electrical and Computer Engineering, University of Massachusetts Amherst, Amherst, MA, 01003, USA
| | - Fatemeh Kiani
- Department of Electrical and Computer Engineering, University of Massachusetts Amherst, Amherst, MA, 01003, USA
| | - Yi Huang
- Department of Electrical and Computer Engineering, University of Massachusetts Amherst, Amherst, MA, 01003, USA
| | - Qiangfei Xia
- Department of Electrical and Computer Engineering, University of Massachusetts Amherst, Amherst, MA, 01003, USA
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12
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Chfii H, Bouich A, Andrio A, Torres JC, Soucase BM, Palacios P, Lefdil MA, Compañ V. The Structural and Electrochemical Properties of CuCoO 2 Crystalline Nanopowders and Thin Films: Conductivity Experimental Analysis and Insights from Density Functional Theory Calculations. Nanomaterials (Basel) 2023; 13:2312. [PMID: 37630896 PMCID: PMC10459735 DOI: 10.3390/nano13162312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 08/07/2023] [Accepted: 08/09/2023] [Indexed: 08/27/2023]
Abstract
A novel manufacturing process is presented for producing nanopowders and thin films of CuCoO2 (CCO) material. This process utilizes three cost-effective synthesis methods: hydrothermal, sol-gel, and solid-state reactions. The resulting delafossite CuCoO2 samples were deposited onto transparent substrates through spray pyrolysis, forming innovative thin films with a nanocrystal powder structure. Prior to the transformation into thin films, CuCoO2 powder was first produced using a low-cost approach. The precursors for both powders and thin films were deposited onto glass surfaces using a spray pyrolysis process, and their characteristics were examined through X-ray diffraction, scanning electron microscopy, HR-TEM, UV-visible spectrophotometry, and electrochemical impedance spectroscopy (EIS) analyses were conducted to determine the conductivity in the transversal direction of this groundbreaking material for solar cell applications. On the other hand, the sheet resistance of the samples was investigated using the four-probe method to obtain the sheet resistivity and then calculate the in-plane conductivity of the samples. We also investigated the aging characteristics of different precursors with varying durations. The functional properties of CuCoO2 samples were explored by studying chelating agent and precursor solution aging periods using Density Functional Theory calculations (DFT). A complementary Density Functional Theory study was also performed in order to evaluate the electronic structure of this compound. Resuming, this study thoroughly discusses the synthesis of delafossite powders and their conversion into thin films, which hold potential as hole transport layers in transparent optoelectronic devices.
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Affiliation(s)
- Hasnae Chfii
- Escuela Técnica Superior de Ingeniería del Diseño, Universitat Politècnica de València, 46022 València, Spain (B.M.S.)
| | - Amal Bouich
- Escuela Técnica Superior de Ingeniería del Diseño, Universitat Politècnica de València, 46022 València, Spain (B.M.S.)
- Instituto de Energía Solar, ETSI Telecomunicación, Universidad Politécnica de Madrid, Ciudad Universitaria, 28040 Madrid, Spain (P.P.)
| | - Andreu Andrio
- Departamento de Física, Universitat Jaume I, 12080 Castellón de la Plana, Spain;
| | - Joeluis Cerutti Torres
- Instituto de Energía Solar, ETSI Telecomunicación, Universidad Politécnica de Madrid, Ciudad Universitaria, 28040 Madrid, Spain (P.P.)
- Departamento Física Aplicada a las Ingenierías Aeronáutica y Naval, ETSI Aeronáutica y del Espacio, Universidad Politécnica de Madrid, Pz. Cardenal Cisneros, 3, 28040 Madrid, Spain
| | - Bernabé Mari Soucase
- Escuela Técnica Superior de Ingeniería del Diseño, Universitat Politècnica de València, 46022 València, Spain (B.M.S.)
| | - Pablo Palacios
- Instituto de Energía Solar, ETSI Telecomunicación, Universidad Politécnica de Madrid, Ciudad Universitaria, 28040 Madrid, Spain (P.P.)
- Departamento Física Aplicada a las Ingenierías Aeronáutica y Naval, ETSI Aeronáutica y del Espacio, Universidad Politécnica de Madrid, Pz. Cardenal Cisneros, 3, 28040 Madrid, Spain
| | | | - Vicente Compañ
- Departamento de Termodinámica Aplicada, Universitat Politècnica de Valencia, 46022 Valencia, Spain
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13
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Kubovcikova M, Sobotova R, Zavisova V, Antal I, Khmara I, Lisnichuk M, Bednarikova Z, Jurikova A, Strbak O, Vojtova J, Mikolka P, Gombos J, Lokajova A, Gazova Z, Koneracka M. N-Acetylcysteine-Loaded Magnetic Nanoparticles for Magnetic Resonance Imaging. Int J Mol Sci 2023; 24:11414. [PMID: 37511170 PMCID: PMC10380599 DOI: 10.3390/ijms241411414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 07/04/2023] [Accepted: 07/06/2023] [Indexed: 07/30/2023] Open
Abstract
Acute respiratory distress syndrome (ARDS) is a life-threatening condition characterized by the rapid onset of lung inflammation Therefore, monitoring the spatial distribution of the drug directly administered to heterogeneously damaged lungs is desirable. In this work, we focus on optimizing the drug N-acetylcysteine (NAC) adsorption on poly-l-lysine-modified magnetic nanoparticles (PLLMNPs) to monitor the drug spatial distribution in the lungs using magnetic resonance imaging (MRI) techniques. The physicochemical characterizations of the samples were conducted in terms of morphology, particle size distributions, surface charge, and magnetic properties followed by the thermogravimetric quantification of NAC coating and cytotoxicity experiments. The sample with the theoretical NAC loading concentration of 0.25 mg/mL was selected as an optimum due to the hydrodynamic nanoparticle size of 154 nm, the surface charge of +32 mV, good stability, and no cytotoxicity. Finally, MRI relaxometry confirmed the suitability of the sample to study the spatial distribution of the drug in vivo using MRI protocols. We showed the prevailing transverse relaxation with high transverse relaxivity values and a high r2(*)/r1 ratio, causing visible hypointensity in the final MRI signal. Furthermore, NAC adsorption significantly affects the relaxation properties of PLLMNPs, which can help monitor drug release in vitro/in vivo.
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Affiliation(s)
- Martina Kubovcikova
- Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 04001 Kosice, Slovakia
| | - Radka Sobotova
- Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 04001 Kosice, Slovakia
| | - Vlasta Zavisova
- Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 04001 Kosice, Slovakia
| | - Iryna Antal
- Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 04001 Kosice, Slovakia
| | - Iryna Khmara
- Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 04001 Kosice, Slovakia
| | - Maksym Lisnichuk
- Faculty of Science, Pavol Jozef Safarik University, Park Angelinum 9, 04001 Kosice, Slovakia
| | - Zuzana Bednarikova
- Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 04001 Kosice, Slovakia
| | - Alena Jurikova
- Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 04001 Kosice, Slovakia
| | - Oliver Strbak
- Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Mala Hora 4, 03601 Martin, Slovakia
| | - Jana Vojtova
- Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Mala Hora 4, 03601 Martin, Slovakia
| | - Pavol Mikolka
- Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Mala Hora 4, 03601 Martin, Slovakia
| | - Jan Gombos
- Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Mala Hora 4, 03601 Martin, Slovakia
| | - Alica Lokajova
- Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Mala Hora 4, 03601 Martin, Slovakia
| | - Zuzana Gazova
- Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 04001 Kosice, Slovakia
| | - Martina Koneracka
- Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 04001 Kosice, Slovakia
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14
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Feng X, Jia G, Peng J, Huang L, Liang X, Zhang H, Liu Y, Zhang B, Zhang Y, Sun M, Li P, Miao Q, Wang Y, Xi L, Hu K, Li T, Hui H, Tian J. Relaxation spectral analysis in multi-contrast vascular magnetic particle imaging. Med Phys 2023. [PMID: 37293867 DOI: 10.1002/mp.16551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 05/01/2023] [Accepted: 05/19/2023] [Indexed: 06/10/2023] Open
Abstract
BACKGROUND Magnetic nanoparticles (MNPs) are used as tracers without ionizing radiation in vascular imaging, molecular imaging, and neuroimaging. The relaxation mechanisms of magnetization in response to excitation magnetic fields are important features of MNPs. The basic relaxation mechanisms include internal rotation (Néel relaxation) and external physical rotation (Brownian relaxation). Accurate measurement of these relaxation times may provide high sensitivity for predicting MNP types and viscosity-based hydrodynamic states. It is challenging to separately measure the Néel and Brownian relaxation components using sinusoidal excitation in conventional MPI. PURPOSE We developed a multi-exponential relaxation spectral analysis method to separately measure the Néel and Brownian relaxation times in the magnetization recovery process in pulsed vascular MPI. METHODS Synomag-D samples with different viscosities were excited using pulsed excitation in a trapezoidal-waveform relaxometer. The samples were excited at different field amplitudes ranging from 0.5 to 10 mT at intervals of 0.5 mT. The inverse Laplace transform-based spectral analysis of the relaxation-induced decay signal in the field-flat phase was performed by using PDCO, a primal-dual interior method for convex objectives. Néel and Brownian relaxation peaks were elucidated and measured on samples with various glycerol and gelatin concentrations. The sensitivity of viscosity prediction of the decoupled relaxation times was evaluated. A digital vascular phantom was designed to mimic a plaque with viscous MNPs and a catheter with immobilized MNPs. Spectral imaging of the digital vascular phantom was simulated by combining a field-free point with homogeneous pulsed excitation. The relationship between the Brownian relaxation time from different tissues and the number of periods for signal averages was evaluated for a scan time estimation in the simulation. RESULTS The relaxation spectra of synomag-D samples with different viscosity levels exhibited two relaxation time peaks. The Brownian relaxation time had a positive linear relationship with the viscosity in the range 0.9 to 3.2 mPa · s. When the viscosity was >3.2 mPa · s, the Brownian relaxation time saturated and did not change with increasing viscosity. The Néel relaxation time decreased slightly with an increase in the viscosity. The Néel relaxation time exhibited a similar saturation effect when the viscosity level was >3.2 mPa · s for all field amplitudes. The sensitivity of the Brownian relaxation time increased with the field amplitude and was maximized at approximately 4.5 mT. The plaque and catheter regions were differentiated from the vessel region in the simulated Brownian relaxation time map. The simulation results show that the Néel relaxation time was 8.33±0.09 μs in the plaque region, 8.30±0.08 μs in the catheter region, and 8.46±0.11 μs in the vessel region. The Brownian relaxation time was 36.60±2.31 μs in the plaque region, 30.17±1.24 μs in the catheter region, and 31.21±1.53 μs in the vessel region. If we used 20 excitation periods for image acquisition in the simulation, the total scan time of the digital phantom was approximately 100 s. CONCLUSION Quantitative assessment of the Néel and Brownian relaxation times through inverse Laplace transform-based spectral analysis in pulsed excitation, highlighting their potential for use in multi-contrast vascular MPI.
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Affiliation(s)
- Xin Feng
- CAS Key Laboratory of Molecular Imaging, Beijing Key Laboratory of Molecular Imaging, The State Key Laboratory of Management and Control for Complex Systems, Institute of Automation, Chinese Academy of Sciences, Beijing, China
| | - Guang Jia
- School of Computer Science and Technology, Xidian University, Xi'an, Shaanxi, China
| | - Jiaming Peng
- School of Life Science and Technology, Xidian University, Xi'an, Shaanxi, China
| | - Liyu Huang
- School of Life Science and Technology, Xidian University, Xi'an, Shaanxi, China
| | - Xiaofeng Liang
- School of Computer Science and Technology, Xidian University, Xi'an, Shaanxi, China
| | - Haoran Zhang
- School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Yanjun Liu
- School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Bo Zhang
- School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Yifei Zhang
- School of Computer Science and Technology, Xidian University, Xi'an, Shaanxi, China
| | - Meng Sun
- School of Computer Science and Technology, Xidian University, Xi'an, Shaanxi, China
| | - Peng Li
- School of Computer Science and Technology, Xidian University, Xi'an, Shaanxi, China
| | - Qiguang Miao
- School of Computer Science and Technology, Xidian University, Xi'an, Shaanxi, China
| | - Ying Wang
- School of Physical Science and Technology, Lanzhou University, Lanzhou, Gansu, China
| | - Li Xi
- School of Physical Science and Technology, Lanzhou University, Lanzhou, Gansu, China
| | - Kai Hu
- School of Physics, Xidian University, Xi'an, Shaanxi, China
| | - Tanping Li
- School of Physics, Xidian University, Xi'an, Shaanxi, China
| | - Hui Hui
- CAS Key Laboratory of Molecular Imaging, Beijing Key Laboratory of Molecular Imaging, The State Key Laboratory of Management and Control for Complex Systems, Institute of Automation, Chinese Academy of Sciences, Beijing, China
| | - Jie Tian
- CAS Key Laboratory of Molecular Imaging, Beijing Key Laboratory of Molecular Imaging, The State Key Laboratory of Management and Control for Complex Systems, Institute of Automation, Chinese Academy of Sciences, Beijing, China
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15
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Antal I, Strbak O, Zavisova V, Vojtova J, Kubovcikova M, Jurikova A, Khmara I, Girman V, Džunda R, Kovaľ K, Koneracka M. Development of Positively Charged Poly-L-Lysine Magnetic Nanoparticles as Potential MRI Contrast Agent. Nanomaterials (Basel) 2023; 13:1831. [PMID: 37368261 DOI: 10.3390/nano13121831] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 06/05/2023] [Accepted: 06/06/2023] [Indexed: 06/28/2023]
Abstract
A colloidal solution of magnetic nanoparticles (MNPs) modified with biocompatible positively charged poly-L-lysine (PLL) with an oleate (OL) layer employed as an initial coating was produced as a potential MRI contrast agent. The effect of various PLL/MNPs' mass ratios on the samples' hydrodynamic diameter, zeta potential, and isoelectric point (IEP) was studied by the dynamic light-scattering method. The optimal mass ratio for MNPs' surface coating was 0.5 (sample PLL0.5-OL-MNPs). The average hydrodynamic particle size in the sample of PLL0.5-OL-MNPs was 124.4 ± 1.4 nm, and in the PLL-unmodified nanoparticles, it was 60.9 ± 0.2 nm, indicating that the OL-MNPs' surface became covered by PLL. Next, the typical characteristics of the superparamagnetic behavior were observed in all samples. In addition, the decrease in saturation magnetizations from 66.9 Am2/kg for MNPs to 35.9 and 31.6 Am2/kg for sample OL-MNPs and PLL0.5-OL-MNPs also confirmed successful PLL adsorption. Moreover, we show that both OL-MNPs and PLL0.5-OL-MNPs exhibit excellent MRI relaxivity properties and a very high r2(*)/r1 ratio, which is very desirable in biomedical applications with required MRI contrast enhancement. The PLL coating itself appears to be the crucial factor in enhancing the relaxivity of MNPs in MRI relaxometry.
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Affiliation(s)
- Iryna Antal
- Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 04001 Kosice, Slovakia
| | - Oliver Strbak
- Biomedical Center Martin, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Mala Hora 4, 03601 Martin, Slovakia
| | - Vlasta Zavisova
- Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 04001 Kosice, Slovakia
| | - Jana Vojtova
- Biomedical Center Martin, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Mala Hora 4, 03601 Martin, Slovakia
| | - Martina Kubovcikova
- Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 04001 Kosice, Slovakia
| | - Alena Jurikova
- Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 04001 Kosice, Slovakia
| | - Iryna Khmara
- Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 04001 Kosice, Slovakia
| | - Vladimir Girman
- Institute of Physics, Faculty of Sciences, Pavol Jozef Safarik University in Kosice, Park Angelinum 9, 04154 Kosice, Slovakia
| | - Róbert Džunda
- Institute of Materials Research, Slovak Academy of Sciences, Watsonova 47, 04001 Kosice, Slovakia
| | - Karol Kovaľ
- Institute of Materials Research, Slovak Academy of Sciences, Watsonova 47, 04001 Kosice, Slovakia
| | - Martina Koneracka
- Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 04001 Kosice, Slovakia
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Fukunaga K, Enzaki M, Komi M, Azuma M, Hirai T, Fujiwara Y. [Evaluation of the Accuracy of Relaxation Time Measurements Using 3D-QALAS at 3.0 T MRI and Comparison with 2D-MDME]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2023:2023-1343. [PMID: 37211403 DOI: 10.6009/jjrt.2023-1343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
PURPOSE Three-dimensional (3D) quantification using an interleaved Look-Locker acquisition sequence with a T2 preparation pulse (QALAS) is a quantitative sequence used to measure relaxation times. The accuracy of the relaxation time measurement of 3D-QALAS at 3.0 T and the bias of 3D-QALAS have not yet been assessed. The purpose of this study was to clarify the accuracy of the relaxation time measurements using 3D-QALAS at 3.0 T MRI. METHODS The accuracy of the T1 and T2 values for 3D-QALAS was evaluated using a phantom. Subsequently, the T1 and T2 values and proton density of the brain parenchyma in healthy subjects were measured using 3D-QALAS and compared with those of 2D multi-dynamic multi-echo (MDME). RESULTS In the phantom study, the average T1 value of 3D-QALAS was 8.3% prolonged than that for conventional inversion recovery spin-echo; the average T2 value for 3D-QALAS was 18.4% shorter than that for multi-echo spin-echo. The in vivo assessment showed that the mean T1 and T2 values and PD for 3D-QALAS were prolonged by 5.3%, shortened by 9.6%, and increased by 7.0%, respectively, compared with those for 2D-MDME. CONCLUSION Although 3D-QALAS at 3.0 T has high accuracy T1 value, which is less than 1000 ms, the T1 value could be overestimated for tissues with it longer than that T1 value. The T2 value for 3D-QALAS could be underestimated for tissues with T2 values, and this tendency increases with longer T2 values.
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Affiliation(s)
- Kota Fukunaga
- Graduate School of Health Sciences, Kumamoto University
| | | | | | - Minako Azuma
- Department of Radiology, Faculty of Medicine, University of Miyazaki
| | - Toshinori Hirai
- Department of Diagnostic Radiology, Faculty of Medicine, Kumamoto University
| | - Yasuhiro Fujiwara
- Department of Medical Image Sciences, Faculty of Life Sciences, Kumamoto University
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Tanaka F. Gelation Time of Network-Forming Polymer Solutions with Reversible Cross-Link Junctions of Variable Multiplicity. Gels 2023; 9:gels9050379. [PMID: 37232971 DOI: 10.3390/gels9050379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 04/30/2023] [Accepted: 05/02/2023] [Indexed: 05/27/2023] Open
Abstract
The gelation time tg necessary for a solution of functional (associating) molecules to reach its gel point after a temperature jump, or a sudden concentration change, is theoretically calculated on the basis of the kinetic equation for the stepwise cross-linking reaction as a function of the concentration, temperature, functionality f of the molecules, and multiplicity k of the cross-link junctions. It is shown that quite generally tg can be decomposed into the product of the relaxation time tR and a thermodynamic factor Q. They are functions of a single scaled concentration x≡λ(T)ϕ, where λ(T) is the association constant and ϕ is the concentration. Therefore, the superposition principle holds with λ(T) as a shift factor of the concentration. Additionally, they all depend on the rate constants of the cross-link reaction, and hence it is possible to estimate these microscopic parameters from macroscopic measurements of tg. The thermodynamic factor Q is shown to depend on the quench depth. It generates a singularity of logarithmic divergence as the temperature (concentration) approaches the equilibrium gel point, while the relaxation time tR changes continuously across it. Gelation time tg obeys a power law tg-1∼xn in the high concentration region, whose power index n is related to the multiplicity of the cross-links. The retardation effect on the gelation time due to the reversibility of the cross-linking is explicitly calculated for some specific models of cross-linking to find the rate-controlling steps in order for the minimization of the gelation time to be easier in the gel processing. For a micellar cross-linking covering a wide range of the multiplicity, as seen in hydrophobically-modified water-soluble polymers, tR is shown to obey a formula similar to the Aniansson-Wall law.
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Affiliation(s)
- Fumihiko Tanaka
- Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Kyoto 615-8510, Japan
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18
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Reuben RL, Hammer SJ, Johnson O, Good DW, Palacio-Torralba J, Candito A, Chen Y, Phipps S, Shu W, McNeill SA. Mechanical mapping of the prostate in vivo using Dynamic Instrumented Palpation; towards an in vivo strategy for cancer assessment. Proc Inst Mech Eng H 2023:9544119231154305. [PMID: 37062899 DOI: 10.1177/09544119231154305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/18/2023]
Abstract
A calibrated palpation sensor has been developed for making instrumented Digital Rectal Examinations (iDREs) with a view to assessing patients for prostate cancer. The instrument measures the dynamic stiffness of the palpable surface of the prostate, and has been trialled on 12 patients in vivo. The patients had been diagnosed with prostate cancer and were scheduled for radical prostatectomy. As far as possible, patients with asymmetric disease were chosen so as to give a variation in gland condition over the palpable surface. The device works by applying an oscillating pressure (force) to a flexible probe whose displacement into the tissue is also measured in order to yield a dynamic stiffness, the static stiffness being incidentally measured at the mean oscillatory force. The device was deployed mounted on the index finger of a urologist and measurements taken at 12-16 positions on each patient using light and firm pressure and palpation frequencies of 1 or 5 Hz. In parallel, conventional DRE assessments were made by a consultant urologist for cancer. After in vivo measurement, the glands were removed and examined histologically with each palpation point being classified as cancerous (C) or not (NC). The work has established the first measurements of static modulus of living prostate tissue to be: 26.8 (13.3) kPa for tissue affected by prostate cancer (C classification), and 24.8 kPa (11.9) for tissue unaffected by cancer (NC classification), values quoted as median (interquartile range). The dynamic properties were characterised by: dynamic modulus, 5.15 kPa (4.86) for the C classification and 4.61 kPa (3.08) for the NC classification and the time lag between force and displacement at 5 Hz palpation frequency, 0.0175 s (0.0078) for the C classification and 0.0186 s (0.0397) for the NC classification, values again quoted as median (interquartile range). With the limited set of features that could be generated, an Artificial Neural Network (ANN) classification yielded a sensitivity of 97%, negative predictive value of 86%, positive predictive value of 67% and accuracy of 70% but with relatively poor specificity (30%). Besides extending the feature set, there are a number of changes in probe design, probing strategy and in mechanics analysis, which are expected to improve the diagnostic capabilities of the method.
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Affiliation(s)
- Robert L Reuben
- Institute for Mechanical, Process and Energy Engineering, School of Engineering and Physical Sciences, Heriot Watt University, Edinburgh, UK
| | - Steven J Hammer
- Institute for Mechanical, Process and Energy Engineering, School of Engineering and Physical Sciences, Heriot Watt University, Edinburgh, UK
| | - Olufemi Johnson
- Institute for Mechanical, Process and Energy Engineering, School of Engineering and Physical Sciences, Heriot Watt University, Edinburgh, UK
| | - Daniel W Good
- Department of Urology, Western General Hospital, Edinburgh, UK
- Edinburgh Urological Cancer Group, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Javier Palacio-Torralba
- Institute for Mechanical, Process and Energy Engineering, School of Engineering and Physical Sciences, Heriot Watt University, Edinburgh, UK
| | - Antonio Candito
- Institute for Mechanical, Process and Energy Engineering, School of Engineering and Physical Sciences, Heriot Watt University, Edinburgh, UK
| | - Yuhang Chen
- Institute for Mechanical, Process and Energy Engineering, School of Engineering and Physical Sciences, Heriot Watt University, Edinburgh, UK
| | - Simon Phipps
- Department of Urology, Western General Hospital, Edinburgh, UK
- Edinburgh Urological Cancer Group, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Will Shu
- Institute for Mechanical, Process and Energy Engineering, School of Engineering and Physical Sciences, Heriot Watt University, Edinburgh, UK
| | - S Alan McNeill
- Department of Urology, Western General Hospital, Edinburgh, UK
- Edinburgh Urological Cancer Group, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
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Li F, Zhang H, Li Y, Zhao Y, Liu M, Yang Y, Yao J, Min S, Kan E, Wan Y. Interface Engineering Modulated Valley Polarization in MoS 2/ hBN Heterostructure. Nanomaterials (Basel) 2023; 13:861. [PMID: 36903739 PMCID: PMC10004763 DOI: 10.3390/nano13050861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 02/15/2023] [Accepted: 02/24/2023] [Indexed: 06/18/2023]
Abstract
Layered transition metal dichalcogenides (TMDs) provide a favorable research platform for the advancement of spintronics and valleytronics because of their unique spin-valley coupling effect, which is attributed to the absence of inversion symmetry coupled with the presence of time-reversal symmetry. To maneuver the valley pseudospin efficiently is of great importance for the fabrication of conceptual devices in microelectronics. Here, we propose a straightforward way to modulate valley pseudospin with interface engineering. An underlying negative correlation between the quantum yield of photoluminescence and the degree of valley polarization was discovered. Enhanced luminous intensities were observed in the MoS2/hBN heterostructure but with a low value of valley polarization, which was in stark contrast to those observed in the MoS2/SiO2 heterostructure. Based on the steady-state and time-resolved optical measurements, we reveal the correlation between exciton lifetime, luminous efficiency, and valley polarization. Our results emphasize the significance of interface engineering for tailoring valley pseudospin in two-dimensional systems and probably advance the progression of the conceptual devices based on TMDs in spintronics and valleytronics.
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Affiliation(s)
- Fang Li
- MIIT Key Laboratory of Semiconductor Microstructure and Quantum Sensing, Department of Applied Physics, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Hui Zhang
- Institute of Physics and Electronic Information, Yunnan Normal University, Kunming 650500, China
| | - You Li
- MIIT Key Laboratory of Semiconductor Microstructure and Quantum Sensing, Department of Applied Physics, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Yibin Zhao
- MIIT Key Laboratory of Semiconductor Microstructure and Quantum Sensing, Department of Applied Physics, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Mingyan Liu
- MIIT Key Laboratory of Semiconductor Microstructure and Quantum Sensing, Department of Applied Physics, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Yunwei Yang
- MIIT Key Laboratory of Semiconductor Microstructure and Quantum Sensing, Department of Applied Physics, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Jiamin Yao
- MIIT Key Laboratory of Semiconductor Microstructure and Quantum Sensing, Department of Applied Physics, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Shaolong Min
- MIIT Key Laboratory of Semiconductor Microstructure and Quantum Sensing, Department of Applied Physics, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Erjun Kan
- MIIT Key Laboratory of Semiconductor Microstructure and Quantum Sensing, Department of Applied Physics, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Yi Wan
- MIIT Key Laboratory of Semiconductor Microstructure and Quantum Sensing, Department of Applied Physics, Nanjing University of Science and Technology, Nanjing 210094, China
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20
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Murzalinov D, Kemelbekova A, Seredavina T, Spivak Y, Serikkanov A, Shongalova A, Zhantuarov S, Moshnikov V, Mukhamedshina D. Self-Organization Effects of Thin ZnO Layers on the Surface of Porous Silicon by Formation of Energetically Stable Nanostructures. Materials (Basel) 2023; 16:838. [PMID: 36676575 PMCID: PMC9860583 DOI: 10.3390/ma16020838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 12/29/2022] [Accepted: 01/10/2023] [Indexed: 06/17/2023]
Abstract
The formation of complex surface morphology of a multilayer structure, the processes of which are based on quantum phenomena, is a promising domain of the research. A hierarchy of pore of various sizes was determined in the initial sample of porous silicon by the atomic force microscopy. After film deposition by spray pyrolysis, ZnO nanoclusters regularly distributed over the sample surface were formed. Using the electron paramagnetic resonance (EPR) method it was determined that the localization of paramagnetic centers occurs more efficiently as a result of the ZnO deposition. An increase in the number of deposited layers, leads to a decrease in the paramagnetic center relaxation time, which is probably connected with the formation of ZnO nanocrystals with energetically stable properties. The nucleation and formation of nanocrystals is associated with the interaction of particles with an uncompensated charge. There is no single approach to determine the mechanism of this process. By the EPR method supplemented with the signal cyclic saturation, spectral manifestations from individual centers were effectively separated. Based on electron paramagnetic resonance and photoluminescence studies it was revealed that the main transitions between energy levels are due to oxygen vacancies and excitons.
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Affiliation(s)
- Danatbek Murzalinov
- Institute of Physics and Technology, Satbayev University, Almaty 050013, Kazakhstan
| | - Ainagul Kemelbekova
- Institute of Physics and Technology, Satbayev University, Almaty 050013, Kazakhstan
| | - Tatyana Seredavina
- Institute of Physics and Technology, Satbayev University, Almaty 050013, Kazakhstan
| | - Yulia Spivak
- Microelectronics Department, Saint-Petersburg State Electrotechnical University, 5 Professora Popova Street, 197376 Saint-Petersburg, Russia
| | - Abay Serikkanov
- Institute of Physics and Technology, Satbayev University, Almaty 050013, Kazakhstan
| | - Aigul Shongalova
- Institute of Physics and Technology, Satbayev University, Almaty 050013, Kazakhstan
| | - Sultan Zhantuarov
- Institute of Physics and Technology, Satbayev University, Almaty 050013, Kazakhstan
| | - Vyacheslav Moshnikov
- Microelectronics Department, Saint-Petersburg State Electrotechnical University, 5 Professora Popova Street, 197376 Saint-Petersburg, Russia
| | - Daniya Mukhamedshina
- Institute of Physics and Technology, Satbayev University, Almaty 050013, Kazakhstan
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21
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Roy S, Vaippully R, Lokesh M, Nalupurackal G, Edwina P, Bajpai S, Roy B. Comparison of translational and rotational modes towards passive rheology of the cytoplasm of MCF-7 cells using optical tweezers. Front Phys 2023; 10:1099958. [PMID: 36685106 PMCID: PMC7614090 DOI: 10.3389/fphy.2022.1099958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
A colloidal particle placed inside the cell cytoplasm is enmeshed within a network of cytoskeletal fibres immersed in the cytosolic fluid. The translational mode is believed to yield different rheological parameters than the rotational mode, given that these modes stretch the fibers differently. We compare the parameters for Michigan Cancer Foundation-7 (MCF-7) cells in this manuscript and find that the results are well comparable to each other. At low values of 0 Hz viscosity, the rotational and translational viscoelasticity matches well. However, discrepancies appear at higher values which may indicate that the cytoskeletal modes involved in rotation and translation of the particle are getting invoked. We also show that the 0 Hz viscosity increases as the cell ages under the conditions of constant room temperature of 25°C on the sample chamber.
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Affiliation(s)
- Srestha Roy
- Department of Physics, Indian Institute of Technology Madras, Chennai, India
| | - Rahul Vaippully
- Department of Physics, Indian Institute of Technology Madras, Chennai, India
| | - Muruga Lokesh
- Department of Physics, Indian Institute of Technology Madras, Chennai, India
| | - Gokul Nalupurackal
- Department of Physics, Indian Institute of Technology Madras, Chennai, India
| | - Privita Edwina
- Department of Applied Mechanics, Indian Institute of Technology Madras, Chennai, India
| | - Saumendra Bajpai
- Department of Applied Mechanics, Indian Institute of Technology Madras, Chennai, India
| | - Basudev Roy
- Department of Physics, Indian Institute of Technology Madras, Chennai, India
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22
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Okada K. [Time-Domain NMR Study to Evaluate Physical Properties of Pharmaceutical Dosage Forms for Process Analysis]. YAKUGAKU ZASSHI 2023; 143:897-903. [PMID: 37914336 DOI: 10.1248/yakushi.23-00115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2023]
Abstract
Here, we sought to investigate the usefulness of time-domain NMR (TD-NMR) for evaluating the physical properties of drug formulations. TD-NMR measures NMR relaxation and is mainly performed using a bench-top low-field NMR system (e.g., 20 MHz); thus, it does not require any specific sample shape for measurement if the sample is not gas. Taking advantage of these features, TD-NMR has been widely used for quality control in food science. However, it has rarely been used in the pharmaceutical field. The T1 and T2 relaxations are not spectra like those obtained by a high-field NMR system (e.g., 300-600 MHz) but only curves in which the NMR signal recovers or decays according to a specific rule. Therefore, selecting the equation used in the fitting analysis is crucial to estimate the time constants, T1 and T2 relaxation times. As the result of a series of studies, the T1 relaxation measurement by TD-NMR was shown to help evaluate the crystallinity of drugs in solid dosage forms and the miscibility of a drug and excipient in a binary mixture. The T2 relaxation measurement was also helpful for quantitatively evaluating the solid form of drugs in a physical mixture with or without moisture adsorption. TD-NMR is an excellent technique widely applied to evaluating the physical properties of various formulations, whether solid or liquid, and is expected to be applied to process analysis and quality control in the pharmaceutical field.
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Affiliation(s)
- Kotaro Okada
- Faculty of Pharmaceutical Sciences, University of Toyama
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23
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Luo XW, Li QX, Shen LS, Zhou X, Zou FY, Tang WJ, Guo RM. Quantitative association of cerebral blood flow, relaxation times and proton density in young and middle-aged primary insomnia patients: A prospective study using three-dimensional arterial spin labeling and synthetic magnetic resonance imaging. Front Neurosci 2023; 17:1099911. [PMID: 37025376 PMCID: PMC10070794 DOI: 10.3389/fnins.2023.1099911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 03/03/2023] [Indexed: 04/08/2023] Open
Abstract
Objectives To quantitatively measure the T1 value, T2 value, proton density (PD) value, and cerebral blood flow (CBF) in young and middle-aged primary insomnia (PI) patients, and analyze the correlations between relaxation times, PD, and CBF to explore potential brain changes. Methods Cranial magnetic resonance (MR) images of 44 PI patients and 30 healthy subjects were prospectively collected for analysis. The T1, T2, PD, and CBF values of the frontal lobe, parietal lobe, temporal lobe, and occipital lobe were independently measured using three-dimensional arterial spin labeling (3D-ASL), synthetic magnetic resonance imaging (syMRI) and a whole-brain automatic segmentation method. The differences of these imaging indices were compared between PI patients and healthy subjects. Follow-up MR images were obtained from PI patients after 6 months to compare with pre-treatment images. The Wilcoxon signed rank test and Spearman rank were used for statistical analysis. Results Bilateral CBF asymmetry was observed in 38 patients, with significant differences in both the T2 value and CBF between the four lobes of the brain (p < 0.01). However, no significant difference was found in the T1 and PD values between the bilateral lobes. A negative correlation was found between CBF and T2 values in the right four lobes of patients with primary insomnia (PI). During follow-up examinations, five PI patients showed a disappearance of insomnia symptoms and a decrease in CBF in both brain lobes. Conclusion Insomnia symptoms may be associated with high CBF, and most PI patients have higher CBF and lower T2 values in the right cerebral hemispheres. The right hemisphere appears to play a critical role in the pathophysiology of PI. The 3D-ASL and syMRI technologies can provide a quantitative imaging basis for investigating the brain conditions and changes in young and middle-aged PI patients.
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24
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Kinnertová E, Slovák V, Zelenka T, Vaulot C, Delmotte L. Carbonaceous Materials Porosity Investigation in a Wet State by Low-Field NMR Relaxometry. Materials (Basel) 2022; 15:9021. [PMID: 36556827 PMCID: PMC9788483 DOI: 10.3390/ma15249021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 12/09/2022] [Accepted: 12/14/2022] [Indexed: 06/17/2023]
Abstract
The porosity of differently wetted carbonaceous material with disordered mesoporosity was investigated using low-field 1H NMR relaxometry. Spin−spin relaxation (relaxation time T2) was measured using the CPMG pulse sequence. We present a non-linear optimization method for the conversion of relaxation curves to the distribution of relaxation times by using non-specialized software. Our procedure consists of searching for the number of components, relaxation times, and their amplitudes, related to different types of hydrogen nuclei in the sample wetted with different amounts of water (different water-to-carbon ratio). We found that a maximum of five components with different relaxation times was sufficient to describe the observed relaxation. The individual components were attributed to a tightly bounded surface water layer (T2 up to 2 ms), water in small pores especially supermicropores (2 < T2 < 7 ms), mesopores (7 < T2 < 20 ms), water in large cavities between particles (20−1500 ms), and bulk water surrounding the materials (T2 > 1500 ms). To recalculate the distribution of relaxation times to the pore size distribution, we calculated the surface relaxivity based on the results provided by additional characterization techniques, such as thermoporometry (TPM) and N2/−196 °C physisorption.
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Affiliation(s)
- Eva Kinnertová
- Department of Chemistry, Faculty of Science, University of Ostrava, 30. Dubna 22, 701 03 Ostrava, Czech Republic
| | - Václav Slovák
- Department of Chemistry, Faculty of Science, University of Ostrava, 30. Dubna 22, 701 03 Ostrava, Czech Republic
| | - Tomáš Zelenka
- Department of Chemistry, Faculty of Science, University of Ostrava, 30. Dubna 22, 701 03 Ostrava, Czech Republic
| | - Cyril Vaulot
- Institut de Science des Matériaux de Mulhouse (IS2M), CNRS UMR 7361, Université de Haute-Alsace, 15 Rue Jean Starcky, 68057 Mulhouse, France
| | - Luc Delmotte
- Institut de Science des Matériaux de Mulhouse (IS2M), CNRS UMR 7361, Université de Haute-Alsace, 15 Rue Jean Starcky, 68057 Mulhouse, France
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25
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Ma HJ, Ma DH, Liu ZP, Zhang JB, Jiang XW, Lu RS. [Effects of paramagnetic material on the characteristics of low field nuclear magnetic resonance signals and water measurement in different textured soils.]. Ying Yong Sheng Tai Xue Bao 2022; 33:3037-3045. [PMID: 36384838 DOI: 10.13287/j.1001-9332.202211.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Nuclear magnetic resonance (NMR) technology has been applied in soil science due to the characte-ristics of high efficiency, rapidity, no damage to soil structure, and harmlessness to the human body. However, the effect of the presence of paramagnetic materials in soils on the characteristics of NMR signals was still unclear. In this study, we investigated the effects of paramagnetic material on the low field nuclear magnetic (LF-NMR) signals and soil water content measurement in soils with different texture. The results showed that the LF-NMR signal of soil water could reach about 150, while that of all the solid materials including soil minerals, organic matter and microbes was less than 0.3, which was relatively negligible. Compared with the NMR signals produced by solid materials in soils, soil texture and paramagnetic material had stronger impact on the measured LF-NMR signals of soil water. LF-NMR equipment had a relaxation time monitoring blind area, and the loss of NMR signal was mainly due to the acceleration of the relaxation process of hydrogen protons in water by magnetic materials, resulting in extremely fast LF-NMR signals feed back by water in small pores that could not be captured by monitoring equipment. For loamy fluvo-aquic soil (1.2%) and clay loamy black soil (1.3%) with low paramagnetic material contents, the loss of LF-NMR signals was not large, which was linearly related to soil water content. For clayey red soil with high content of clay (45.3%) and paramagnetic materials (4.0%), a part of the LF-NMR signals would be lost in the measurement, and the monitored LF-NMR signal was not linearly related to the soil water content. In addition, external addition of paramagnetic materials (3.0 g·L-1 MnCl2 solution) would further reduce the LF-NMR signals that could be monitored in black and red soils. The maximum signal loss rates of black soil and red soil were 41.0% and 46.7%, respectively, which greatly changed the quantitative relationship between it and soil water content. Therefore, the influence of paramagnetic materials on the LF-NMR signals should be reduced first through correction when using LF-NMR to measure the water content of clay soil with rich internal paramagnetic materials (>1.3%) or external addition of paramagnetic materials. Our results would provide valuable insights into the study of soil water content measurement and soil pore structure analysis using low field nuclear magnetic resonance technology.
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Affiliation(s)
- Hong-Jiao Ma
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Dong-Hao Ma
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
| | - Zhi-Peng Liu
- College of Resources and Environmental Science, Nanjing Agricultural University, Nanjing 210095, China
| | - Jia-Bao Zhang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
| | - Xiao-Wen Jiang
- Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, Southeast University, Nanjing 211189, China
| | - Rong-Sheng Lu
- Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, Southeast University, Nanjing 211189, China
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26
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Weber A, Benitez R, Toca‐Herrera JL. Measuring biological materials mechanics with atomic force microscopy - Determination of viscoelastic cell properties from stress relaxation experiments. Microsc Res Tech 2022; 85:3284-3295. [PMID: 35736395 PMCID: PMC9796732 DOI: 10.1002/jemt.24184] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 06/03/2022] [Accepted: 06/06/2022] [Indexed: 01/07/2023]
Abstract
Cells are complex, viscoelastic bodies. Their mechanical properties are defined by the arrangement of semiflexible cytoskeletal fibers, their crosslinking, and the active remodeling of the cytoskeletal network. Atomic force microscopy (AFM) is an often-used technique for the study of cell mechanics, enabling time- and frequency-dependent measurements with nanometer resolution. Cells exhibit time-dependent deformation when stress is applied. In this work, we have investigated the stress relaxation of HeLa cells when subjected to a constant strain. We have varied the applied force (1, 2, 4, and 8 nN) and pause time (1, 10, and 60 s) to check for common assumptions for the use of models of linear viscoelasticity. Then, we have applied three models (standard linear solid, five element Maxwell, power law rheology) to study their suitability to fit the datasets. We show that the five element Maxwell model captures the stress relaxation response the best while still retaining a low number of free variables. This work serves as an introduction and guide when performing stress relaxation experiments on soft matter using AFM. RESEARCH HIGHLIGHTS: Cells exhibit linear viscoelastic properties when subjected to stress relaxation measurements at the studied different forces and times. The stress relaxation is best described by a five element Maxwell model. All three used models capture a softening and fluidization of cells when disrupting actin filaments.
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Affiliation(s)
- Andreas Weber
- Institute of Biophysics, Department of NanobiotechnologyUniversity of Natural Resources and Life Sciences Vienna (BOKU)ViennaAustria
| | - Rafael Benitez
- Departamento de Matemáticas para la Economía y la EmpresaFacultad de Economía, Universidad de ValenciaValenciaSpain
| | - José L. Toca‐Herrera
- Institute of Biophysics, Department of NanobiotechnologyUniversity of Natural Resources and Life Sciences Vienna (BOKU)ViennaAustria
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27
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El Sabbagh N, Bonny JM, Clerjon S, Chassain C, Pagés G. Characterization of the sodium binding state in several food products by 23 Na nuclear magnetic resonance spectroscopy. Magn Reson Chem 2022; 60:597-605. [PMID: 35037331 DOI: 10.1002/mrc.5250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 01/12/2022] [Accepted: 01/13/2022] [Indexed: 06/14/2023]
Abstract
In food, salt has several key roles including conservative and food perception. For this latter, it is well-known that the interaction of sodium with the food matrix modifies the consumer perception. It is then critical to characterize these interactions in various real foods. For this purpose, we exploited the information obtained on both single and double quantum 23 Na nuclear magnetic resonance (NMR) spectroscopies. All salted food samples studied showed strong interactions with the food matrix leading to quadrupolar interactions. However, for some of them, the single quantum analysis did not match the theoretical prediction. This was explained by the presence of another type of sodium population, which did not produce quadrupolar interactions. This finding is of critical importance to perform quantitative magnetic resonance imaging (MRI) and to understand the consumer salty taste perception.
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Affiliation(s)
- Nour El Sabbagh
- UR QuaPA, INRAE, Saint-Gènes-Champanelle, France
- PROBE Research Infrastructure, AgroResonance Facility, INRAE, Saint-Genès-Champanelle, France
- CHU, CNRS, Clermont Auvergne INP, Institut Pascal, Université Clermont Auvergne, Clermont-Ferrand, France
| | - Jean-Marie Bonny
- UR QuaPA, INRAE, Saint-Gènes-Champanelle, France
- PROBE Research Infrastructure, AgroResonance Facility, INRAE, Saint-Genès-Champanelle, France
| | - Sylvie Clerjon
- UR QuaPA, INRAE, Saint-Gènes-Champanelle, France
- PROBE Research Infrastructure, AgroResonance Facility, INRAE, Saint-Genès-Champanelle, France
| | - Carine Chassain
- UR QuaPA, INRAE, Saint-Gènes-Champanelle, France
- PROBE Research Infrastructure, AgroResonance Facility, INRAE, Saint-Genès-Champanelle, France
- CHU, CNRS, Clermont Auvergne INP, Institut Pascal, Université Clermont Auvergne, Clermont-Ferrand, France
| | - Guilhem Pagés
- UR QuaPA, INRAE, Saint-Gènes-Champanelle, France
- PROBE Research Infrastructure, AgroResonance Facility, INRAE, Saint-Genès-Champanelle, France
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28
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Clerjon S, El Sabbagh N, Pages G, Traore A, Bonny JM. Quantitative sodium magnetic resonance imaging in food: Addressing sensitivity issues using single quantum chemical shift imaging at high field. Magnetic Reson in Chemistry 2022; 60:628-636. [PMID: 34907589 DOI: 10.1002/mrc.5239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 12/10/2021] [Accepted: 12/11/2021] [Indexed: 06/14/2023]
Abstract
According to various health organizations, the global consumption of salt is higher than recommended and needs to be reduced. Ideally, this would be achieved without losing the taste of the salt itself. In order to accomplish this goal, both at the industrial and domestic levels, we need to understand the mechanisms that govern the final distribution of salt in food. The in-silico solutions in use today greatly over-simplify the real food structure. Measuring the quantity of sodium at the local level is key to understanding sodium distribution. Sodium magnetic resonance imaging (MRI), a non-destructive approach, is the ideal choice for salt mapping along transformational process. However, the low sensitivity of the sodium nucleus and its short relaxation times make this imaging difficult. In this paper, we show how sodium MRI can be used to highlight salt heterogeneities in food products, provided that the temporal decay is modeled, thus correcting for differences in relaxation speeds. We then propose an abacus which shows the relationship between the signal-to-noise ratio of the sodium MRI, the salt concentration, the B0 field, and the spatial and temporal resolutions. This abacus simplifies making the right choices when implementing sodium MRI.
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Affiliation(s)
- Sylvie Clerjon
- INRAE, UR QuaPA, St Genes Champanelle, France
- INRAE, PROBE Research Infrastructure, AgroResonance Facility, St Genes Champanelle, France
| | - Nour El Sabbagh
- INRAE, UR QuaPA, St Genes Champanelle, France
- INRAE, PROBE Research Infrastructure, AgroResonance Facility, St Genes Champanelle, France
- Institute Pascal, Clermont Auvergne University, CHU, CNRS, Clermont Auvergne INP, Clermont-Ferrand, France
| | - Guilhem Pages
- INRAE, UR QuaPA, St Genes Champanelle, France
- INRAE, PROBE Research Infrastructure, AgroResonance Facility, St Genes Champanelle, France
| | - Amidou Traore
- INRAE, UR QuaPA, St Genes Champanelle, France
- INRAE, PROBE Research Infrastructure, AgroResonance Facility, St Genes Champanelle, France
| | - Jean-Marie Bonny
- INRAE, UR QuaPA, St Genes Champanelle, France
- INRAE, PROBE Research Infrastructure, AgroResonance Facility, St Genes Champanelle, France
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Rondeau-Mouro C, Cambert M, Blondel L, Diascorn Y, Mbaya L, Binti Ahmad Nazari NN, Helary S, Lucas T. Portable single-sided NMR measurements at variable temperatures: Implementation of a thermo-controlled device and application to the heating of bread dough. Magn Reson Chem 2022; 60:678-691. [PMID: 35092067 DOI: 10.1002/mrc.5254] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 01/24/2022] [Accepted: 01/25/2022] [Indexed: 06/14/2023]
Abstract
A temperature control unit was implemented to vary the temperature of samples studied on a commercial Mobile Universal Surface Explorer nuclear magnetic resonance (MOUSE-NMR) apparatus. The device was miniaturized to fit the maximum MOUSE sampling depth (25 mm). It was constituted by a sample holder sandwiched between two heat exchangers placed below and above the sample. Air was chosen as the fluid to control the temperature at the bottom of the sample, at the interface between the NMR probe and the sample holder, in order to gain space. The upper surface of the sample was regulated by the circulation of water inside a second heat exchanger placed above the sample holder. The feasibility of using such a device was demonstrated first on pure water and then on several samples of bread dough with different water contents. For this, T1 relaxation times were measured at various temperatures and depths and were then compared with those acquired with a conventional compact closed-magnet spectrometer. Discussion of results was based on biochemical transformations in bread dough (starch gelatinization and gluten heat denaturation). It was demonstrated that, within a certain water level range, and because of the low magnetic field strength of the MOUSE, a linear relationship could be established between T1 relaxation times and the local temperature in the dough sample.
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30
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Wu G, Liu L, Wang T, Pan C. T1 mapping is useful for staging deep venous thrombosis in the lower extremities. Acta Radiol 2022; 63:489-496. [PMID: 33910379 DOI: 10.1177/02841851211004425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND The discrimination of acute and chronic deep venous thrombosis (DVT) is of great importance. Quantitative imaging is an urgent requirement in reflecting intrinsic characteristics of thrombosis. PURPOSE To investigate the feasibility of T1 mapping in staging DVT in the lower extremities. MATERIAL AND METHODS A total of 57 patients with DVT in the lower extremities (26 men, 31 women; mean age = 53.3 years) underwent T1-weighted imaging and T1 mapping for obtaining T1 signal intensity (SI) and T1 time of thrombus. The relative SI (rSI) of DVT was obtained by calculating the ratio of thrombus SI to muscle SI. The Mann-Whitney U test was used to compare rSI and T1 time of DVT between acute group (patients with limb edema ≤ 2 weeks) and chronic group (patients with limb edema > 2 weeks). A receiver operator characteristic (ROC) curve was constructed for further evaluation. RESULTS DVT rSI was significantly higher in the acute group versus the chronic group (2.8 ± 1.2 vs. 1.4 ± 0.6; P<0.05). DVT T1 time was significantly lower in the acute group versus the chronic group (819.4 ± 223.7 ms vs. 1264.8 ± 270.7 ms; P<0.05). The area under the curve (AUC) was 0.93 for T1 time and 0.75 for rSI. When using 1015 ms as the cut-off, the sensitivity and specificity of T1 time were 91% (32/35) and 86% (19/22), respectively. CONCLUSION T1 mapping is a potential technique in discriminating acute from chronic DVT in the lower extremities and warrants further investigation.
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Affiliation(s)
- Gang Wu
- Department of Radiology, Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology, Wuhan, PR China
| | - Liangjin Liu
- Department of Radiology, Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology, Wuhan, PR China
| | - Ting Wang
- Department of Ultrasound, Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology, Wuhan, PR China
| | - Chu Pan
- Department of Radiology, Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology, Wuhan, PR China
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Yamashiro A, Saito T, Miyati T. Development of a novel task-based functional magnetic resonance imaging phantom based on a bubble-compression approach. Med Phys 2022; 49:3717-3728. [PMID: 35287246 DOI: 10.1002/mp.15599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 01/25/2022] [Accepted: 03/02/2022] [Indexed: 11/12/2022] Open
Abstract
PURPOSE Phantoms used in previous functional magnetic resonance imaging (fMRI) studies have drawbacks, such as a complicated circuit and equipment use, a single signal-change rate, and T2 * values that do not correspond to those of living human brains. We aimed to develop a phantom for use in task-based fMRI studies (gradient-echo echo-planar imaging; GRE-EPI) with bioequivalent T1 and T2 * values, using an innovative method to control the rate of signal change. METHODS A gel phantom with T1 and T2 * values equivalent to that of the living brain gray matter was fixed in a 150 mm diameter container, with five holes, each of which could hold a 30-mL syringe. The gel phantom contained microscopic air bubbles; this made it possible to control the percent signal change by injector-induced water pressure changes. Using this phantom, we investigated the percent signal change, derived an equation that can approximately reproduce an arbitrary percent signal change, compared different gel phantom samples, investigated the change in relaxation time and bubble size during signal change, and assessed the change in values in each sample over time. RESULTS The relaxation time of the gel phantom was similar to the literature values for gray matter. The percent signal change achieved was approximately 0-13.51% and was dependent on the water pressure change. The derived equation was y = 0.000008x3 - 0.000771x2 + 0.034222x - 0.026054, with y being the percent signal change and x being the pressure in kPa; the reproducibility was high. No significant difference was detected among samples of gray matter gel phantoms (P > 0.05). The change in the rate of signal change with the change in water pressure was due to the change in T2 * value with the change in bubble size. With pressure increasing from 0 to 151.7 kPa, the T2 * value increased from 52 ms to 85 ms. The newly developed gel phantom was stable for 60 days, but its bubble size changed after 21 days. CONCLUSION We developed a novel phantom for use in fMRI, which could reproduce minute signal changes similar to the blood-oxygen-level-dependent effect and with bioequivalent T1 and T2 * values, and used an innovative method to control the percent signal change by compressing the air contained in the phantom for validation of fMRI using GRE-EPI. This phantom reproduced the percent signal change due to changes in T2 * values, which is very similar to scanning a human body. This phantom is expected to be a powerful tool for advancing the study of task-based fMRI. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Akihiro Yamashiro
- Department of Radiology, Nagano Red Cross Hospital, 5-22-1 Wakasato, Nagano-City, Nagano, 380-8582, Japan.,Division of Health Sciences, Graduate School of Medical Sciences, Kanazawa University, 5-11-80 Kodatuno, Kanazawa-City, Ishikawa, 920-0942, Japan
| | - Takaaki Saito
- Department of Radiology, Iiyama Red Cross Hospital, 226-1 Iiyama, Iiyama-City, Nagano, 389-2295, Japan
| | - Tosiaki Miyati
- Division of Health Sciences, Graduate School of Medical Sciences, Kanazawa University, 5-11-80 Kodatuno, Kanazawa-City, Ishikawa, 920-0942, Japan
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Sahoo A, Paul T, Maiti S, Banerjee R. Temperature-dependent dielectric properties of CsPb 2Br 5: a 2D inorganic halide perovskite. Nanotechnology 2022; 33:195703. [PMID: 35090144 DOI: 10.1088/1361-6528/ac4fe5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 01/28/2022] [Indexed: 06/14/2023]
Abstract
Two dimensional (2D) CsPb2Br5have been successfully synthesized via the chemical precipitation method. Detailed structural, morphological, optical, and dielectric studies of these materials have been performed. These 2D CsPb2Br5plates (of thickness around 200-300 nm) are ascribed to a tetragonal lattice system withI4/mcmspace group. The dielectric attributes such as dielectric constant, electrical modulus, loss factor, and the DC, and AC conductivities, are observed to be varying appreciably with temperature over an extensive frequency window of 10 Hz-50 MHz. The Nyquist plots are investigated using the Maxwell-Wagner equivalent circuit model, which shows the impact of grains and grain boundaries on the overall impedance. Both the free charge conductivity and space charge increase with an increment in temperature, as revealed from the modified Cole-Cole plot. The relaxation time and relaxation mechanism of 2D CsPb2Br5are estimated using the Kohlrausch-Williams-Watts equation. Variation in DC conductivity and relaxation time, as a function of temperature, closely resembles Arrhenius' behavior. Value of activation energy calculated from the DC conductivity corroborates with the same derived from relaxation time. The observation of high dielectric constant and nominal dielectric loss for CsPb2Br5perovskite offers enormous potential in energy harvesting and storage devices.
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Affiliation(s)
- Aditi Sahoo
- CSIR-Central Glass & Ceramic Research Institute, Kolkata 700032, India
| | - Tufan Paul
- Department of Physics, Indian Institute of Technology Gandhinagar, Palaj, Gandhinagar 382355, India
| | - Soumen Maiti
- St. Thomas Colleges of Engineering & Technology, Kolkata 700023, India
| | - Rupak Banerjee
- Department of Physics, Indian Institute of Technology Gandhinagar, Palaj, Gandhinagar 382355, India
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Lomovskoy VA, Shatokhina SA, Chalykh AE, Matveev VV. Spectra of Internal Friction in Polyethylene. Polymers (Basel) 2022; 14:675. [PMID: 35215586 DOI: 10.3390/polym14040675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 01/28/2022] [Accepted: 01/31/2022] [Indexed: 02/01/2023] Open
Abstract
The study of spectra of internal friction λ=fT and temperature dependencies of frequency of freely damped ν=fT oscillatory process excited in investigated samples of polyethylene with different degree of crystallinity in the temperature range from −150 °C to +150 °C. It is established that four local dissipative processes of different intensity shown in different temperature intervals are observed on the spectra λ=fT. These are μ, β, α, βk processes. The theoretical analysis of the relationship between the anomalous changes of the vibrational process frequency ν=fT and the shift modulus defect ΔG=fT and the internal friction mechanisms for each of the dissipative loss processes detected on the spectrum λ=fT is carried out. The influence of supramolecular structures on local dissipative βk process in polyethylene is estimated.
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Sun SY, Ding Y, Li Z, Nie L, Liao C, Liu Y, Zhang J, Zhang D. Multiparameter MRI Model With DCE-MRI, DWI, and Synthetic MRI Improves the Diagnostic Performance of BI-RADS 4 Lesions. Front Oncol 2021; 11:699127. [PMID: 34722246 PMCID: PMC8554332 DOI: 10.3389/fonc.2021.699127] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 09/27/2021] [Indexed: 11/22/2022] Open
Abstract
Objectives To evaluate the value of synthetic magnetic resonance imaging (syMRI), diffusion-weighted imaging (DWI), DCE-MRI, and clinical features in breast imaging–reporting and data system (BI-RADS) 4 lesions, and develop an efficient method to help patients avoid unnecessary biopsy. Methods A total of 75 patients with breast diseases classified as BI-RADS 4 (45 with malignant lesions and 30 with benign lesions) were prospectively enrolled in this study. T1-weighted imaging (T1WI), T2WI, DWI, and syMRI were performed at 3.0 T. Relaxation time (T1 and T2), apparent diffusion coefficient (ADC), conventional MRI features, and clinical features were assessed. “T” represents the relaxation time value of the region of interest pre-contrast scanning, and “T+” represents the value post-contrast scanning. The rate of change in the T value between pre- and post-contrast scanning was represented by ΔT%. Results ΔT1%, T2, ADC, age, body mass index (BMI), menopause, irregular margins, and heterogeneous internal enhancement pattern were significantly associated with a breast cancer diagnosis in the multivariable logistic regression analysis. Based on the above parameters, four models were established: model 1 (BI-RADS model, including all conventional MRI features recommended by BI-RADS lexicon), model 2 (relaxation time model, including ΔT1% and T2), model 3 [multi-parameter (mp)MRI model, including ΔT1%, T2, ADC, margin, and internal enhancement pattern], and model 4 (combined image and clinical model, including ΔT1%, T2, ADC, margin, internal enhancement pattern, age, BMI, and menopausal state). Among these, model 4 has the best diagnostic performance, followed by models 3, 2, and 1. Conclusions The mpMRI model with DCE-MRI, DWI, and syMRI is a robust tool for evaluating the malignancies in BI-RADS 4 lesions. The clinical features could further improve the diagnostic performance of the model.
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Affiliation(s)
- Shi Yun Sun
- Department of Radiology, Yunnan Cancer Center, The Third Affiliated Hospital of Kunming Medical University, Yunnan Cancer Hospital, Kunming, China
| | - Yingying Ding
- Department of Radiology, Yunnan Cancer Center, The Third Affiliated Hospital of Kunming Medical University, Yunnan Cancer Hospital, Kunming, China
| | - Zhuolin Li
- Department of Radiology, Yunnan Cancer Center, The Third Affiliated Hospital of Kunming Medical University, Yunnan Cancer Hospital, Kunming, China
| | - Lisha Nie
- Magnetic Resonance Imaging Research, General Electric Healthcare (China), Beijing, China
| | - Chengde Liao
- Department of Radiology, Yunnan Cancer Center, The Third Affiliated Hospital of Kunming Medical University, Yunnan Cancer Hospital, Kunming, China
| | - Yifan Liu
- Department of Radiology, Yunnan Cancer Center, The Third Affiliated Hospital of Kunming Medical University, Yunnan Cancer Hospital, Kunming, China
| | - Jia Zhang
- Department of Radiology, Third People's Hospital of Yunnan Province, Kunming, China
| | - Dongxue Zhang
- Department of Radiology, Yunnan Cancer Center, The Third Affiliated Hospital of Kunming Medical University, Yunnan Cancer Hospital, Kunming, China
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Zhang M, Tian Z, Cheng Y, Liu H, Nan Q. [Application of hyperbolic heat transfer model in atrial fibrillation microwave ablation]. Sheng Wu Yi Xue Gong Cheng Xue Za Zhi 2021; 38:885-892. [PMID: 34713656 DOI: 10.7507/1001-5515.202009084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The effect of relaxation time in hyperbolic heat transfer model on the temperature field of microwave ablation of atrial fibrillation was investigated. And the results were compared with those calculated by Pennes model. A three-dimensional model of microwave ablation of atrial fibrillation was constructed. The relaxation time ( τ) was 0, 1, 5, 8, 10, 15 and 20 s, respectively. And the temperature field of myocardial tissue was obtained. The results showed that the highest temperature of the hyperbolic model was 21.8 ℃ lower than that of the Pennes model at the beginning of ablation. With the increase of ablation time, the highest temperature tended to be the same. The lesion dimensions appeared at 3, 4, 6, 7, 8, 9, and 10 s, respectively after ablation. Therefore, the influence of hyperbolic model on temperature will decrease with the increase of the ablation time. At the beginning of ablation, the relaxation time will hinder the speed of myocardial thermal diffusion. The larger the relaxation time is, the slower the speed of thermal diffusion is. This study provides a reference for the application of hyperbolic model in microwave ablation of atrial fibrillation.
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Affiliation(s)
- Meng Zhang
- Department of Biomedical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, P.R.China.,Intelligent Physiological Measurement and Clinical Translation, Beijing International Base for Scientific and Technological Cooperation, Beijing 100124, P.R.China
| | - Zhen Tian
- Department of Biomedical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, P.R.China.,Intelligent Physiological Measurement and Clinical Translation, Beijing International Base for Scientific and Technological Cooperation, Beijing 100124, P.R.China
| | - Yanyan Cheng
- Department of Biomedical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, P.R.China.,Intelligent Physiological Measurement and Clinical Translation, Beijing International Base for Scientific and Technological Cooperation, Beijing 100124, P.R.China
| | - Hongxing Liu
- Department of Biomedical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, P.R.China.,Intelligent Physiological Measurement and Clinical Translation, Beijing International Base for Scientific and Technological Cooperation, Beijing 100124, P.R.China
| | - Qun Nan
- Department of Biomedical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, P.R.China.,Intelligent Physiological Measurement and Clinical Translation, Beijing International Base for Scientific and Technological Cooperation, Beijing 100124, P.R.China
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Sasaki T, Tsuzuki Y, Nakane T. A Dynamically Correlated Network Model for the Collective Dynamics in Glass-Forming Molecular Liquids and Polymers. Polymers (Basel) 2021; 13:3424. [PMID: 34641239 PMCID: PMC8512962 DOI: 10.3390/polym13193424] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Revised: 10/02/2021] [Accepted: 10/03/2021] [Indexed: 11/23/2022] Open
Abstract
The non-Arrhenius behavior of segmental dynamics in glass-forming liquids is one of the most profound mysteries in soft matter physics. In this article, we propose a dynamically correlated network (DCN) model to understand the growing behavior of dynamically correlated regions during cooling, which leads to the viscous slowdown of supercooled liquids. The fundamental concept of the model is that the cooperative region of collective motions has a network structure that consists of string-like parts, and networks of various sizes interpenetrate each other. Each segment undergoes dynamical coupling with its neighboring segments via a finite binding energy. Monte Carlo simulations showed that the fractal dimension of the DCNs generated at different temperatures increased and their size distribution became broader with decreasing temperature. The segmental relaxation time was evaluated based on a power law with four different exponents for the activation energy of rearrangement with respect to the DCN size. The results of the present DCN model are consistent with the experimental results for various materials of molecular and polymeric liquids.
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Affiliation(s)
- Takashi Sasaki
- Department of Materials Science and Engineering, University of Fukui, Fukui 9108507, Japan; (Y.T.); (T.N.)
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Bogaert J, Claessen G, Dresselaers T, Masci PG, Belge C, Delcroix M, Symons R. Magnetic resonance relaxometry of the liver - a new imaging biomarker to assess right heart failure in pulmonary hypertension. J Heart Lung Transplant 2021; 41:86-94. [PMID: 34686407 DOI: 10.1016/j.healun.2021.09.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 08/22/2021] [Accepted: 09/07/2021] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Right heart failure (RHF) in pulmonary hypertension (PH) patients is manifested by increased right atrial (RA) pressure. We hypothesized liver relaxation times measured at cardiovascular magnetic resonance (CMR) can be used to noninvasively assess increased right-sided filling pressure. METHODS Forty-five consecutive patients, that is, 37 PH patients and 8 chronic thromboembolic pulmonary disease patients without PH underwent right heart catheterization and CMR. CMR findings were compared to 40 control subjects. Native T1, T2, and extracellular volume (ECV) liver values were measured on the cardiac maps. RESULTS Patients with increased RA pressure (i.e.,≥8 mm Hg)(n = 19, RA+ group) showed higher NT-proBNP and CRP values, lower LVEF, MAPSE values, larger atrial size, and higher native T1 and T2 values of the myocardium than patients with normal RA pressure (RA- group, n = 26). Liver T1, T2 and ECV was significantly higher in RA+ than RA- patients and controls, that is, T1: 684 ± 129 ms vs 563 ± 72 ms and 540 ± 34 ms; T2: 60 ± 10 ms vs 49 ± 6 ms and 46 ± 4 ms; ECV: 36 ± 8% vs 29 ± 4% and 30 ± 3%. A positive correlation was found between liver T1, T2 and ECV and RA pressure, that is, r2 of 0.61, 0.82, and 0.58, respectively (p < 0.001). ROC analysis to depict increased RA pressure showed an AUC of 0.847, 0.904, 0.816, and 0.645 for liver T1, T2, NT-proNBP and gamma-glutamyl transpeptidase, respectively. Excellent intra- and inter-observer agreement was found for assessment of T1/T2/ECV liver values. CONCLUSIONS Assessment of liver relaxation times as part of a comprehensive CMR exam in PH patients may provide valuable information with regard to the presence of passive liver congestion.
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Affiliation(s)
- Jan Bogaert
- Dept of Imaging and Pathology, KU Leuven and Dept of Radiology, University Hospitals Leuven, Leuven, Belgium.
| | - Guido Claessen
- Dpt of Cardiovascular Sciences, KU Leuven and Dept of Cardiovascular Diseases, University Hospitals Leuven, Leuven, Belgium
| | - Tom Dresselaers
- Dept of Imaging and Pathology, KU Leuven and Dept of Radiology, University Hospitals Leuven, Leuven, Belgium
| | - Pier Giorgio Masci
- School of Biomedical Engineering and Imaging Sciences, King's College London, St Thomas Hospital, London, United Kingdom
| | - Catharina Belge
- Clinical Department of Respiratory Diseases, Centre of Pulmonary Vascular Diseases, University Hospitals of Leuven, Leuven, Belgium; BREATHE, department of CHROMETA, KU Leuven, Leuven, Belgium
| | - Marion Delcroix
- Clinical Department of Respiratory Diseases, Centre of Pulmonary Vascular Diseases, University Hospitals of Leuven, Leuven, Belgium; BREATHE, department of CHROMETA, KU Leuven, Leuven, Belgium
| | - Rolf Symons
- Dept of Imaging and Pathology, KU Leuven and Dept of Radiology, University Hospitals Leuven, Leuven, Belgium
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Kalous T, Holec P, Erben J, Bilek M, Batka O, Pokorny P, Chaloupek J, Chvojka J. The Optimization of Alternating Current Electrospun PA 6 Solutions Using a Visual Analysis System. Polymers (Basel) 2021; 13:2098. [PMID: 34202197 DOI: 10.3390/polym13132098] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 06/16/2021] [Accepted: 06/24/2021] [Indexed: 12/31/2022] Open
Abstract
The electrospinning process that produces fine nanofibrous materials have a major disadvantage in the area of productivity. However, alternating current (AC) electrospinning might help to solve the problem via the modification of high voltage signal. The aforementioned productivity aspect can be observed via a camera system that focuses on the jet creation area and that measures the average lifespan. The paper describes the optimization of polyamide 6 (PA 6) solutions and demonstrates the change in the behavior of the process following the addition of a minor dose of oxoacid. This addition served to convert the previously unspinnable (using AC) solution to a high-quality electrospinning solution. The visual analysis of the AC electrospinning of polymeric solutions using a high-speed camera and a programmable power source was chosen as the method for the evaluation of the quality of the process. The solutions were exposed to high voltage applying two types of AC signal, i.e., the sine wave and the step change. All the recordings presented in the paper contained two sets of data: firstly, camera recordings that showed the visual expression of electrospinning and, secondly, signal recordings that provided information on the data position in the signal function.
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Mochizuki A, Oda Y, Miwa Y. Comparative study on water structures of poly(tetrahydrofurfuryl acrylate) and poly(2-hydroxyethyl methacrylate) by nuclear magnetic resonance spectroscopy. J Biomater Sci Polym Ed 2021; 32:1754-1769. [PMID: 34075853 DOI: 10.1080/09205063.2021.1938356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
It is well known that poly(2-methoxyethyl acrylate) (PMEA) has good blood compatibility and its performance is attributed to its water structure. Recently, we applied solution nuclear magnetic resonance spectroscopy (solution-NMR) for analyzing the water structure in PMEA at ambient temperature and concluded that this method is useful because of the clear observation of the resonance peaks at low and high magnetic field (downfield and upfield, respectively) areas indicating the existence of more than two types of water. The present study was performed to compare the water structure of poly(tetrahydrofurfuryl acrylate) (PTHFA) and poly(2-hydroxyethyl methacrylate) (PHEMA) using solution 2H-NMR and deuterium oxide as water at the temperature range 15-45 °C. It was found that PTHFA has a different water structure from that of PHEMA. Water in PTHFA clearly showed two resonance peaks at downfield and upfield areas, with different spin-lattice relaxation times, T12H (high and low values, respectively). These observations are similar to those of PMEA. In contrast, PHEMA showed only one broad resonance peak (at downfield) with a low T12H value. Based on these observations, this study discusses the effect of water structures on the blood compatibility of these polymers.
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Affiliation(s)
- Akira Mochizuki
- Department of Bio-Medical Engineering, School of Engineering, Tokai University, Isehara, Kanagawa, Japan
| | - Yoshiki Oda
- Technology Joint Management Office of Tokai University, Hiratsuka, Kanagawa, Japan
| | - Yuko Miwa
- Toray Research Center Inc., Otsu, Shiga, Japan
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Lavoisier A, Shreeram S, Jedwab M, Ramaioli M. Effect of the rheological properties of the liquid carrier on the in vitro swallowing of solid oral dosage forms. J Texture Stud 2021; 52:623-637. [PMID: 34118071 DOI: 10.1111/jtxs.12618] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 05/23/2021] [Accepted: 06/06/2021] [Indexed: 11/29/2022]
Abstract
Solid oral dosage forms (SODF) are the most popular oral drug delivery forms, but they can be difficult to swallow, especially for patients suffering from swallowing disorders. This study investigated the dynamics of different combinations of liquid carriers and SODF during the oral phase of swallowing using an in vitro model. The rheological properties of the carriers were characterized using shear and extensional rheometry, and their effect on bolus velocity, bolus shape, post-swallow residues, and SODF position within the bolus was evaluated. The latter has been identified as a novel and promising variable to discriminate between alternative formulations. When swallowed with water, capsules and tablets did not impact significantly the velocity of the bolus, but they lagged behind the liquid bolus, suggesting that low viscosity Newtonian fluids are not efficient carriers for SODF. Increasing the viscosity of the carrier at high shear rates improved the ability of the liquid to transport the SODF but also increased the amount of post-swallow residues. At equivalent shear viscosity, elastic and extensional properties of carriers influenced positively the position of the SODF in the bolus. Capsules and tablets were transported toward the front of these boluses, during the oral phase of swallowing, which is considered beneficial to avoid SODF sticking to the mucosa in the following stages of swallowing. Thin elastic liquids appear as an interesting option to promote safe swallowing of capsules and tablets. Clinical studies are, however, necessary to confirm this positive effect in healthy and dysphagic patients.
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Affiliation(s)
- Anaïs Lavoisier
- Paris-Saclay Food and Bioproduct Engineering research unit, INRAE, AgroParisTech, Massy, France
| | | | | | - Marco Ramaioli
- Paris-Saclay Food and Bioproduct Engineering research unit, INRAE, AgroParisTech, Massy, France
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Fan Q, Yang J, Cao J, Liu C. Thermoelectric performances for both p- and n-type GeSe. R Soc Open Sci 2021; 8:201980. [PMID: 34113450 PMCID: PMC8188002 DOI: 10.1098/rsos.201980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 05/12/2021] [Indexed: 06/12/2023]
Abstract
In this paper, the thermoelectric properties of p-type and n-type GeSe are studied systematically by using first principles and Boltzmann transport theory. The calculation includes electronic structure, electron relaxation time, lattice thermal conductivity and thermoelectric transport properties. The results show that GeSe is an indirect band gap semiconductor with band gap 1.34 eV. Though p-type GeSe has a high density of states near Fermi level, the electronic conductivity is relative low because there is no carrier transport pathway along the a-axis direction. For n-type GeSe, a charge density channel is formed near conduction band minimum, which improves the electrical conductivity of n-type GeSe along the a-axis direction. At 700 K, the optimal ZT value reaches 2.5 at 4 × 1019 cm-3 for n-type GeSe, while that is 0.6 at 1 × 1020 cm-3 for p-type GeSe. The results show n-type GeSe has better thermoelectric properties than p-type GeSe, indicating that n-type GeSe is a promising thermoelectric material in middle temperature.
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Affiliation(s)
- Qiang Fan
- School of Electronic and Material Engineering, Leshan Normal University, Leshan 614004, Sichuan, People's Republic of China
| | - Jianhui Yang
- School of Mathematics and Physics, Leshan Normal University, Leshan 614004, Sichuan, People's Republic of China
| | - Jin Cao
- School of Mathematics and Physics, Leshan Normal University, Leshan 614004, Sichuan, People's Republic of China
| | - Chunhai Liu
- College of Materials and Chemistry and Chemical Engineering, Chengdu University of Technology, Chengdu 610059, People's Republic of China
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Lin-Wei O, Xian LLS, Shen VTW, Chuan CY, Halim SA, Ghani ARI, Idris Z, Abdullah JM. Deep Tendon Reflex: The Tools and Techniques. What Surgical Neurology Residents Should Know. Malays J Med Sci 2021; 28:48-62. [PMID: 33958960 PMCID: PMC8075597 DOI: 10.21315/mjms2021.28.2.5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Accepted: 12/07/2020] [Indexed: 11/04/2022] Open
Abstract
The deep tendon reflex (DTR) is a key component of the neurological examination. However, interpretation of the results is a challenge since there is a lack of knowledge on the important features of reflex responses such as the amount of hammer force, the strength of contraction, duration of the contraction and relaxation. The tools used to elicit the reflexes also play a role in the quality of the reflex contraction. Furthermore, improper execution techniques during the DTR assessment may alter the findings and cloud the true assessment of the nervous system. Therefore, understanding the basic principles and the key features of DTR allows for better interpretation of the reflex responses. This paper discusses the brief history of reflexes, the development of the reflex hammer, and also the key features of a reflex response encompassing the amplitude of force needed to elicit a reflex response, the velocity of contraction, the strength of contraction, and the duration of contraction and relaxation phases. The final section encloses the techniques of eliciting DTR in the upper extremities, trunk, and lower extremities, and the interpretation of these reflexes.
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Affiliation(s)
- Ooi Lin-Wei
- Department of Neurosciences, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia.,Hospital Universiti Sains Malaysia, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia.,Department of Neurosurgery, Hospital Umum Sarawak, Kuching, Sarawak, Malaysia
| | - Leonard Leong Sang Xian
- Department of Neurosciences, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia.,Hospital Universiti Sains Malaysia, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia.,Department of Neurosurgery, Hospital Sungai Buloh, Sungai Buloh, Selangor, Malaysia
| | - Vincent Tee Wei Shen
- Hospital Universiti Sains Malaysia, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia
| | - Chee Yong Chuan
- Department of Neurosciences, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia.,Neurology Unit, Department of Internal Medicine, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia.,Hospital Universiti Sains Malaysia, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia
| | - Sanihah Abdul Halim
- Department of Neurosciences, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia.,Neurology Unit, Department of Internal Medicine, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia.,Hospital Universiti Sains Malaysia, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia.,Brain Behaviour Cluster, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia
| | - Abdul Rahman Izani Ghani
- Department of Neurosciences, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia.,Hospital Universiti Sains Malaysia, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia.,Brain Behaviour Cluster, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia
| | - Zamzuri Idris
- Department of Neurosciences, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia.,Hospital Universiti Sains Malaysia, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia.,Brain Behaviour Cluster, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia
| | - Jafri Malin Abdullah
- Department of Neurosciences, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia.,Hospital Universiti Sains Malaysia, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia.,Brain Behaviour Cluster, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia
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Do TN, Huang D, Shih PH, Lin H, Gumbs G. Atomistic Band-Structure Computation for Investigating Coulomb Dephasing and Impurity Scattering Rates of Electrons in Graphene. Nanomaterials (Basel) 2021; 11:1194. [PMID: 34062735 DOI: 10.3390/nano11051194] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 04/27/2021] [Accepted: 04/28/2021] [Indexed: 11/17/2022]
Abstract
In this paper, by introducing a generalized quantum-kinetic model which is coupled self-consistently with Maxwell and Boltzmann transport equations, we elucidate the significance of using input from first-principles band-structure computations for an accurate description of ultra-fast dephasing and scattering dynamics of electrons in graphene. In particular, we start with the tight-binding model (TBM) for calculating band structures of solid covalent crystals based on localized Wannier orbital functions, where the employed hopping integrals in TBM have been parameterized for various covalent bonds. After that, the general TBM formalism has been applied to graphene to obtain both band structures and wave functions of electrons beyond the regime of effective low-energy theory. As a specific example, these calculated eigenvalues and eigen vectors have been further utilized to compute the Bloch-function form factors and intrinsic Coulomb diagonal-dephasing rates for induced optical coherence of electron-hole pairs in spectral and polarization functions, as well as the energy-relaxation time from extrinsic impurity scattering of electrons for non-equilibrium occupation in band transport.
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Hänninen NE, Nykänen O, Prakash M, Hanni M, Nieminen MT, Nissi MJ. Orientation anisotropy of quantitative MRI parameters in degenerated human articular cartilage. J Orthop Res 2021; 39:861-870. [PMID: 32543737 DOI: 10.1002/jor.24778] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 05/08/2020] [Accepted: 06/12/2020] [Indexed: 02/04/2023]
Abstract
Quantitative magnetic resonance (MR) relaxation parameters demonstrate varying sensitivity to the orientation of the ordered tissues in the magnetic field. In this study, the orientation dependence of multiple relaxation parameters was assessed in cadaveric human cartilage with varying degree of natural degeneration, and compared with biomechanical testing, histological scoring, and quantitative histology. Twelve patellar cartilage samples were imaged at 9.4 T MRI with multiple relaxation parameters, including T1 , T2 , CW - T1ρ , and adiabatic T1ρ , at three different orientations with respect to the main magnetic field. Anisotropy of the relaxation parameters was quantified, and the results were compared with the reference measurements and between samples of different histological Osteoarthritis Research Society International (OARSI) grades. T2 and CW - T1ρ at 400 Hz spin-lock demonstrated the clearest anisotropy patterns. Radial zone anisotropy for T2 was significantly higher for samples with OARSI grade 2 than for grade 4. The proteoglycan content (measured as optical density) correlated with the radial zone MRI orientation anisotropy for T2 (r = 0.818) and CW - T1ρ with 400 Hz spin-lock (r = 0.650). Orientation anisotropy of MRI parameters altered with progressing cartilage degeneration. This is associated with differences in the integrity of the collagen fiber network, but it also seems to be related to the proteoglycan content of the cartilage. Samples with advanced OA had great variation in all biomechanical and histological properties and exhibited more variation in MRI orientation anisotropy than the less degenerated samples. Understanding the background of relaxation anisotropy on a molecular level would help to develop new MRI contrasts and improve the application of previously established quantitative relaxation contrasts.
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Affiliation(s)
- Nina Elina Hänninen
- Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland.,Department of Applied Physics, University of Eastern Finland, Kuopio, Finland
| | - Olli Nykänen
- Department of Applied Physics, University of Eastern Finland, Kuopio, Finland
| | - Mithilesh Prakash
- Department of Applied Physics, University of Eastern Finland, Kuopio, Finland.,A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Matti Hanni
- Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland.,Medical Research Center Oulu, Oulu University Hospital, University of Oulu, Oulu, Finland.,Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland
| | - Miika Tapio Nieminen
- Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland.,Medical Research Center Oulu, Oulu University Hospital, University of Oulu, Oulu, Finland.,Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland
| | - Mikko Johannes Nissi
- Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland.,Department of Applied Physics, University of Eastern Finland, Kuopio, Finland
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Meisak D, Macutkevic J, Selskis A, Kuzhir P, Banys J. Dielectric Relaxation Spectroscopy and Synergy Effects in Epoxy/MWCNT/Ni@C Composites. Nanomaterials (Basel) 2021; 11:555. [PMID: 33672334 DOI: 10.3390/nano11020555] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 02/02/2021] [Accepted: 02/20/2021] [Indexed: 11/16/2022]
Abstract
The dielectric/electric properties of the Ni@C (carbon-coated Ni)/epoxy composites and Ni@C/MWCNTs (multi-walled carbon nanotubes)/epoxy composites loaded with fixed MWCNTs amount just below the percolation threshold (0.09 vol.%) and Ni@C at different concentrations up to 1 vol.% were investigated in broad frequency (20 Hz–40 GHz) and temperature (30 K–500 K) regions. In composites with the only Ni@C nanoparticles, the electrical percolation threshold was determined between 10 and 15 vol.%. Above the percolation threshold the dielectric permittivity (ε’) and the electrical conductivity (σ) of the composites loaded with Ni@C only are high enough, i.e., ε’ = 105 and σ = 0.6 S/m at 100 Hz for composites with 30 vol.% Ni@C, to be used for electromagnetic shielding applications. The annealing to 500 K was proved to be an effective and simple tool to decrease the percolation threshold in epoxy/Ni@C composites. For hybrid composites series an optimal concentration of Ni@C (0.2 vol.%) was determined, leading to the conductivity absolute values several orders of magnitude higher than that of a composite filled with MWCNTs only. The synergy effects of using both fillers have been discussed. Below room temperature the electrical transport is mainly governed by epoxy resin compression in all composites, while the electron tunnelling was observed only in hybrid composites below 200 K. At higher temperatures (above 400 K), in addition to the nanoparticles redistribution effects, the electrical conductivity of epoxy resin makes a significant contribution to the total composite conductivity. The dielectric relaxation spectroscopy allows estimating the nanoparticles distributions in polymer matrix and could be used as the non-destructive and fast alternate to microscopy techniques for general polymer composite fabrication control.
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Giannokostas K, Dimakopoulos Y, Anayiotos A, Tsamopoulos J. Advanced Constitutive Modeling of the Thixotropic Elasto-Visco-Plastic Behavior of Blood: Steady-State Blood Flow in Microtubes. Materials (Basel) 2021; 14:E367. [PMID: 33451107 PMCID: PMC7828603 DOI: 10.3390/ma14020367] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 01/02/2021] [Accepted: 01/09/2021] [Indexed: 12/15/2022]
Abstract
The present work focuses on the in-silico investigation of the steady-state blood flow in straight microtubes, incorporating advanced constitutive modeling for human blood and blood plasma. The blood constitutive model accounts for the interplay between thixotropy and elasto-visco-plasticity via a scalar variable that describes the level of the local blood structure at any instance. The constitutive model is enhanced by the non-Newtonian modeling of the plasma phase, which features bulk viscoelasticity. Incorporating microcirculation phenomena such as the cell-free layer (CFL) formation or the Fåhraeus and the Fåhraeus-Lindqvist effects is an indispensable part of the blood flow investigation. The coupling between them and the momentum balance is achieved through correlations based on experimental observations. Notably, we propose a new simplified form for the dependence of the apparent viscosity on the hematocrit that predicts the CFL thickness correctly. Our investigation focuses on the impact of the microtube diameter and the pressure-gradient on velocity profiles, normal and shear viscoelastic stresses, and thixotropic properties. We demonstrate the microstructural configuration of blood in steady-state conditions, revealing that blood is highly aggregated in narrow tubes, promoting a flat velocity profile. Additionally, the proper accounting of the CFL thickness shows that for narrow microtubes, the reduction of discharged hematocrit is significant, which in some cases is up to 70%. At high pressure-gradients, the plasmatic proteins in both regions are extended in the flow direction, developing large axial normal stresses, which are more significant in the core region. We also provide normal stress predictions at both the blood/plasma interface (INS) and the tube wall (WNS), which are difficult to measure experimentally. Both decrease with the tube radius; however, they exhibit significant differences in magnitude and type of variation. INS varies linearly from 4.5 to 2 Pa, while WNS exhibits an exponential decrease taking values from 50 mPa to zero.
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Affiliation(s)
- Konstantinos Giannokostas
- Laboratory of Fluid Mechanics and Rheology, Department of Chemical Engineering, University of Patras, 26504 Patras, Greece; (K.G.); (J.T.)
| | - Yannis Dimakopoulos
- Laboratory of Fluid Mechanics and Rheology, Department of Chemical Engineering, University of Patras, 26504 Patras, Greece; (K.G.); (J.T.)
| | - Andreas Anayiotos
- Department of Mechanical and Materials Engineering, Cyprus University of Technology, Limassol 3036, Cyprus;
| | - John Tsamopoulos
- Laboratory of Fluid Mechanics and Rheology, Department of Chemical Engineering, University of Patras, 26504 Patras, Greece; (K.G.); (J.T.)
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Abstract
The viscosity and the relaxation time of a glass-forming liquid vary over 15 orders of magnitude before the liquid freezes into a glass. The rate of the change with temperature is characterized by liquid fragility. The mechanism of such a spectacular behavior and the origin of fragility have long been discussed, but it remains unresolved because of the difficulty of carrying out experiments and constructing theories that bridge over a wide timescale from atomic (ps) to bulk (minutes). Through the x-ray diffraction measurement and molecular dynamics simulation for metallic liquids we suggest that large changes in viscosity can be caused by relatively small changes in the structural coherence which characterizes the medium-range order. Here the structural coherence does not imply that of atomic-scale structure, but it relates to the coarse-grained density fluctuations represented by the peaks in the pair-distribution function (PDF) beyond the nearest neighbors. The coherence length is related to fragility and increases with decreasing temperature, and it diverges only at a negative temperature. This analysis is compared with several current theories which predict a phase transition near the glass transition temperature.
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Affiliation(s)
- Takeshi Egami
- Department of Materials Science and Engineering, Shull-Wollan Center - Joint Institute for Neutron Sciences, University of Tennessee, Knoxville, Knoxville, TN, United States.,Department of Physics and Astronomy, University of Tennessee, Knoxville, Knoxville, TN, United States.,Materials Sciences and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Chae Woo Ryu
- Department of Materials Science and Engineering, Shull-Wollan Center - Joint Institute for Neutron Sciences, University of Tennessee, Knoxville, Knoxville, TN, United States
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Abstract
Random walks have been proven to be useful for constructing various algorithms to gain information on networks. Algorithm node2vec employs biased random walks to realize embeddings of nodes into low-dimensional spaces, which can then be used for tasks such as multi-label classification and link prediction. The performance of the node2vec algorithm in these applications is considered to depend on properties of random walks that the algorithm uses. In the present study, we theoretically and numerically analyse random walks used by the node2vec. Those random walks are second-order Markov chains. We exploit the mapping of its transition rule to a transition probability matrix among directed edges to analyse the stationary probability, relaxation times in terms of the spectral gap of the transition probability matrix, and coalescence time. In particular, we show that node2vec random walk accelerates diffusion when walkers are designed to avoid both backtracking and visiting a neighbour of the previously visited node but do not avoid them completely.
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Affiliation(s)
- Lingqi Meng
- Department of Mathematics, University at Buffalo, State University of New York, Buffalo, NY 14260-2900, USA
| | - Naoki Masuda
- Department of Mathematics, University at Buffalo, State University of New York, Buffalo, NY 14260-2900, USA
- Computational and Data-Enabled Science and Engineering Program, University at Buffalo, State University of New York, Buffalo, NY 14260-5030, USA
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Arai K, Shikata T. Hydration/Dehydration Behavior of Hydroxyethyl Cellulose Ether in Aqueous Solution. Molecules 2020; 25:molecules25204726. [PMID: 33076298 PMCID: PMC7587591 DOI: 10.3390/molecules25204726] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 10/05/2020] [Accepted: 10/12/2020] [Indexed: 12/03/2022] Open
Abstract
Hydroxyethyl cellulose (HeC) maintains high water solubility over a wide temperature range even in a high temperature region where other nonionic chemically modified cellulose ethers, such as methyl cellulose (MC) and hydroxypropylmethyl cellulose (HpMC), demonstrate cloud points. In order to clarify the reason for the high solubility of HeC, the temperature dependence of the hydration number per glucopyranose unit, nH, for the HeC samples was examined by using extremely high frequency dielectric spectrum measuring techniques up to 50 GHz over a temperature range from 10 to 70 °C. HeC samples with a molar substitution number (MS) per glucopyranose unit by hydroxyethyl groups ranging from 1.3 to 3.6 were examined in this study. All HeC samples dissolve into water over the examined temperature range and did not show their cloud points. The value of nH for the HeC sample possessing the MS of 1.3 was 14 at 20 °C and decreased gently with increasing temperature and declined to 10 at 70 °C. The nH values of the HeC samples are substantially larger than the minimum critical nH value of ca. 5 necessary to be dissolved into water for cellulose ethers such as MC and HpMC, even in a high temperature range. Then, the HeC molecules possess water solubility over the wide temperature range. The temperature dependence of nH for the HeC samples and triethyleneglycol, which is a model compound for substitution groups of HeC, is gentle and they are similar to each other. This observation strongly suggests that the hydration/dehydration behavior of the HeC samples was essentially controlled by that of their substitution groups.
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Affiliation(s)
- Kengo Arai
- Cellulose Research Unit, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan;
| | - Toshiyuki Shikata
- Cellulose Research Unit, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan;
- Division of Natural Resources and Eco-materials, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan
- Correspondence:
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Mastalska-Popławska J, Stempkowska A, Habina-Skrzyniarz I, Krzyżak AT, Rutkowski P, Izak P, Rudny J, Gawenda T. Water Interactions in Hybrid Polyacrylate-Silicate Hydrogel Systems. Materials (Basel) 2020; 13:E4092. [PMID: 32942635 PMCID: PMC7560421 DOI: 10.3390/ma13184092] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 09/09/2020] [Accepted: 09/11/2020] [Indexed: 11/16/2022]
Abstract
Hybrid polyacrylate-silicate hydrogels were obtained in the presence of N,N'-methylenebisacrylamide (NNMBA) as the cross-linking monomer and sodium thiosulphate/potassium persulphate (NTS/KPS) as the redox initiators. The results of the tests allowed us to conclude that a hybrid structure with a polyacrylate scaffolding and a silicate matrix had been obtained. The results of the rheological analysis revealed that the hydrogel sample with a 1:7 mass ratio of sodium water glass to the sodium polyacrylate is characterized by the highest complex viscosity. Thermal analysis (Thermogravimetry/Differential Scanning Calorimetry (TG/DSC)) showed that water begins to evaporate at higher temperatures, from 120 °C to even 180 °C. These results were confirmed by mid-infrared spectroscopy (MIR) and nuclear magnetic resonance spectroscopy (NMR) analysis. Differences in the intensity of the peaks derived from water in the MIR spectra indicate that most of the water is bounded. In turn, NMR results showed that the mobility of water molecules decreases as the amount of sodium water glass in the mixture increases.
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Affiliation(s)
- Joanna Mastalska-Popławska
- Faculty of Materials Science and Ceramics, AGH University of Science and Technology, Mickiewicza 30 Av., 30-059 Krakow, Poland; (P.R.); (P.I.); (J.R.)
| | - Agata Stempkowska
- Faculty of Mining and Geoengineering, AGH University of Science and Technology, Mickiewicza 30 Av., 30-059 Krakow, Poland; (A.S.); (T.G.)
| | - Iwona Habina-Skrzyniarz
- Faculty of Geology, Geophysics and Environmental Protection, AGH University of Science and Technology, Mickiewicza 30 Av., 30-059 Krakow, Poland; (I.H.-S.); (A.T.K.)
| | - Artur T. Krzyżak
- Faculty of Geology, Geophysics and Environmental Protection, AGH University of Science and Technology, Mickiewicza 30 Av., 30-059 Krakow, Poland; (I.H.-S.); (A.T.K.)
| | - Paweł Rutkowski
- Faculty of Materials Science and Ceramics, AGH University of Science and Technology, Mickiewicza 30 Av., 30-059 Krakow, Poland; (P.R.); (P.I.); (J.R.)
| | - Piotr Izak
- Faculty of Materials Science and Ceramics, AGH University of Science and Technology, Mickiewicza 30 Av., 30-059 Krakow, Poland; (P.R.); (P.I.); (J.R.)
| | - Jakub Rudny
- Faculty of Materials Science and Ceramics, AGH University of Science and Technology, Mickiewicza 30 Av., 30-059 Krakow, Poland; (P.R.); (P.I.); (J.R.)
| | - Tomasz Gawenda
- Faculty of Mining and Geoengineering, AGH University of Science and Technology, Mickiewicza 30 Av., 30-059 Krakow, Poland; (A.S.); (T.G.)
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