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Cho JD, Jung S, Kim JI, Choi CH. Improvement of performance for flexible film dosimeter by incorporating additive agents. Phys Med Biol 2024. [PMID: 38565123 DOI: 10.1088/1361-6560/ad39c1] [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: 04/04/2024]
Abstract
OBJECTIVE To evaluate the reduction in energy dependence and aging effect of the lithium salt of pentacosa-10,-12-diynoic acid (LiPCDA) films with additives including aluminum oxide (Al2O3), propyl gallate (PG), and disodium ethylenediaminetetracetate (EDTA). APPROACH LiPCDA films exhibited energy dependence on kilovoltage (kV) and megavoltage (MV) photon energies and experienced deterioration over time. Evaluations were conducted with added Al₂O₃ and antioxidants to mitigate these issues, and films were produced with and without Al₂O₃ to assess energy dependence. The films were irradiated at doses of 0, 3, 6, and 12 cGy at photon energies of 75 kV, 105 kV, 6 MV, 10 MV, and 15 MV. For the energy range of 75 kV to 15 MV, the mean and standard deviation (std) were calculated and compared for the values normalized to the net optical density (netOD) at 6 MV, corresponding to identical dose levels. To evaluate the aging effect, PG and disodium EDTA were incorporated into the films: sample C with 1% PG, sample D with 2% PG, sample E with 0.62% disodium EDTA added to sample D, and sample F with 1.23% disodium EDTA added to sample D. MAIN RESULTS Films containing Al2O3 demonstrated a maximum 15.8% increase in mean normalized values and a 15.1% reduction in std, reflecting a greater netOD reduction at kV than MV energies, which indicates less energy dependence in these films. When the OD of sample 1-4 depending on the addition of PG and disodium EDTA, was observed for 20 weeks, the transmission mode decreased by 8.7%, 8.3%, 29.3%, and 27.3%, respectively, while the reflection mode was 5.4. %, 3.0%, 37.0%, and 34.5%, respectively. SIGNIFICANCE Al2O3 effectively reduced the voltage and MV energy dependence. PG was more effective than disodium EDTA in preventing the deterioration of film performance owing to the aging effect.
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Affiliation(s)
- Jin Dong Cho
- Department of Radiation Oncology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, JONGNO-GU, 29 Saemunan-ro, SEOUL, 03181, Korea (the Republic of)
| | - Seongmoon Jung
- Department of Radiation Oncology, Seoul National University Hospital, JONGNO-GU, 101 DAEHAK-RO, SEOUL, 03080, Korea (the Republic of)
| | - Jung-In Kim
- Department of Radiation Oncology, Seoul National University Hospital, JONGNO-GU, 101 DAEHAK-RO, SEOUL, 03080, Korea (the Republic of)
| | - Chang Heon Choi
- Department of Radiation Oncology, Seoul National University Hospital, JONGNO-GU, 101 DAEHAK-RO, SEOUL, 03080, Korea (the Republic of)
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Zhou L, Nguyen TD, Chiang GC, Wang XH, Xi K, Hu T, Tanzi EB, Butler TA, de Leon MJ, Li Y. Parenchymal CSF fraction is a measure of brain glymphatic clearance and positively associated with amyloid beta deposition on PET. Alzheimers Dement 2024; 20:2047-2057. [PMID: 38184796 PMCID: PMC10984424 DOI: 10.1002/alz.13659] [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: 09/15/2023] [Revised: 11/29/2023] [Accepted: 11/30/2023] [Indexed: 01/08/2024]
Abstract
INTRODUCTION Mapping of microscopic changes in the perivascular space (PVS) of the cerebral cortex, beyond magnetic resonance-visible PVS in white matter, may enhance our ability to diagnose Alzheimer's disease (AD) early. METHODS We used the cerebrospinal fluid (CSF) water fraction (CSFF), a magnetic resonance imaging-based biomarker, to characterize brain parenchymal CSF water, reflecting microscopic PVS in parenchyma. We measured CSFF and amyloid beta (Aβ) using 11 C Pittsburgh compound B positron emission tomography to investigate their relationship at both the subject and voxel levels. RESULTS Our research has demonstrated a positive correlation between the parenchymal CSFF, a non-invasive imaging biomarker indicative of parenchymal glymphatic clearance, and Aβ deposition, observed at both individual and voxel-based assessments in the posterior cingulate cortex. DISCUSSION This study shows that an increased parenchymal CSFF is associated with Aβ deposition, suggesting that CSFF could serve as a biomarker for brain glymphatic clearance, which can be used to detect early fluid changes in PVS predisposing individuals to the development of AD. HIGHLIGHTS Cerebrospinal fluid fraction (CSFF) could be a biomarker of parenchymal perivascular space. CSFF is positively associated with amyloid beta (Aβ) deposition at subject level. CSFF in an Aβ+ region is higher than in an Aβ- region in the posterior cingulate cortex. Correspondence is found between Aβ deposition and glymphatic clearance deficits measured by CSFF.
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Affiliation(s)
- Liangdong Zhou
- Department of RadiologyBrain Health Imaging Institute (BHII)Weill Cornell MedicineNew YorkNew YorkUSA
| | - Thanh D. Nguyen
- Department of RadiologyMRI Research Institute (MRIRI)Weill Cornell MedicineNew YorkNew YorkUSA
| | - Gloria C. Chiang
- Department of RadiologyBrain Health Imaging Institute (BHII)Weill Cornell MedicineNew YorkNew YorkUSA
- Department of RadiologyDivision of NeuroradiologyWeill Cornell MedicineNew York‐Presbyterian HospitalNew YorkNew YorkUSA
| | - Xiuyuan H. Wang
- Department of RadiologyBrain Health Imaging Institute (BHII)Weill Cornell MedicineNew YorkNew YorkUSA
| | - Ke Xi
- Department of RadiologyBrain Health Imaging Institute (BHII)Weill Cornell MedicineNew YorkNew YorkUSA
| | - Tsung‐Wei Hu
- Department of RadiologyBrain Health Imaging Institute (BHII)Weill Cornell MedicineNew YorkNew YorkUSA
| | - Emily B. Tanzi
- Department of RadiologyBrain Health Imaging Institute (BHII)Weill Cornell MedicineNew YorkNew YorkUSA
| | - Tracy A. Butler
- Department of RadiologyBrain Health Imaging Institute (BHII)Weill Cornell MedicineNew YorkNew YorkUSA
| | - Mony J. de Leon
- Department of RadiologyBrain Health Imaging Institute (BHII)Weill Cornell MedicineNew YorkNew YorkUSA
| | - Yi Li
- Department of RadiologyBrain Health Imaging Institute (BHII)Weill Cornell MedicineNew YorkNew YorkUSA
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Castilla A, Berthoz A, Urukalo D, Zaoui M, Perrochon A, Kronovsek T. Age and sex impact on visuospatial working memory (VSWM), mental rotation, and cognitive strategies during navigation. Neurosci Res 2022; 183:84-96. [PMID: 35905778 DOI: 10.1016/j.neures.2022.07.007] [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: 02/24/2022] [Revised: 06/12/2022] [Accepted: 07/24/2022] [Indexed: 11/30/2022]
Abstract
This study assessed the impact of sex and typical aging on visuospatial working memory (VSWM), mental rotations, and navigational strategies using behavioral information. Fifty healthy participants regrouped in older (OA) and young adults (YA) performed the Walking Corsi test (WalCT) and the Redrawn Mental Rotation Test (MRT) to explore mental rotation abilities. We recorded kinematic data such as locomotion trajectories, and spatial orientations during navigation. We created a new method of data analysis for the WalCT performances and compared it with the classical approach. This original method allowed us to identify cognitive strategies based on errors analysis. Our data suggested that VSWM and mental rotation capacities in locomotion were modulated by age (YA scored higher than OA), and sex (Young Adult Males (YA-M) having higher performance than Young Adult Females (YA-F). We observed a preferential use of cognitive strategies related to sex; YA-F relied more on egocentric strategies whereas YA-M relied more on allocentric strategies. The preferential use of cognitive strategies in the YA group was not observed in the OA group producing more random errors per sequence. The results suggest the effects that age and sex have on VSWM, cognitive strategies, and mental rotation during navigation and highlight the importance of navigational strategies training.
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Affiliation(s)
- Alexander Castilla
- Laboratoire de Psychologie du Développement et de l'Éducation de l'Enfant (LaPsyDÉ), Université de Paris Cité, Paris, France; Laboratoire Psychologie & Neurosciences Institut de Médecine Environnementale (IME), 114 Bd Malesherbes, 75017 Paris, France; Collège de France, Centre Interdisciplinaire de Biologie, 11 Place Marcelin Berthelot, 75005 Paris, France.
| | - Alain Berthoz
- Collège de France, Centre Interdisciplinaire de Biologie, 11 Place Marcelin Berthelot, 75005 Paris, France
| | | | - Mohamed Zaoui
- Collège de France, Centre Interdisciplinaire de Biologie, 11 Place Marcelin Berthelot, 75005 Paris, France
| | | | - Téo Kronovsek
- Université de Limoges, HAVAE, EA 6310, F-87000 Limoges, France
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Wang JJ, Chen XC, Li QD, Jin CJ, Huang YJ, Fan LJ, Zhang JY, Liu XH, Xu KQ. [Effects of Aging on the Cd Adsorption by Microplastics and the Relevant Mechanisms]. Huan Jing Ke Xue 2022; 43:2030-2038. [PMID: 35393826 DOI: 10.13227/j.hjkx.202107221] [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: 06/14/2023]
Abstract
It has been verified that, as an emerging contaminant, microplastics are capable of adsorbing certain traditional contaminants like the heavy metal Cd. However, the majority of previous studies only focused on certain types of virgin microplastics, especially for PE and PS. In addition, this adsorption process might be affected by microplastics inevitably undergoing aging and consequent changes in the natural environment. Unfortunately, the relevant reports on aging effects were mainly about organic pollutants, rather than heavy metals. By far, there have been few comprehensive and mechanistic studies on the key aging effects on the Cd adsorption by various types of microplastics. In this study, five representative types of microplastics (i.e., PS, ABS, PP, PVC, and PET) were selected for aging by ultraviolet radiation, and the physicochemical properties of virgin and aged microplastics were thoroughly compared, including specific surface area, crystallinity, surface functional groups, and surface elements. Accordingly, the changes in adsorption isotherms of Cd by microplastics were discussed. The results showed that:① aging induced non-significant changes in specific surface area but a significant decrease in crystallinity. Surface functional groups also changed, including the emergence of a C=O functional group on PS and ABS, the decrease in C=C absorption peak intensity on ABS, and the increase in absorption peak intensities of C=O, C-O, and polar ester groups on PET. Regarding surface C content, C=C/C-C decreased, whereas C-O and O-C=O increased. The total O content and O/C significantly increased as well. ② The Langmuir model well-fitted the adsorption isotherms of Cd by virgin and aged microplastics. Aging significantly expanded the adsorption capacity of Cd by microplastics, as the order of saturated adsorption capacity before aging was ABS (0.2284 mg·g-1)>PVC (0.1360 mg·g-1)>PS (0.1286 mg·g-1)>PP (0.1005 mg·g-1)>PET (0.0462 mg·g-1) and then became PS (0.2768 mg·g-1)>ABS (0.2586 mg·g-1)>PVC (0.1776 mg·g-1)>PP (0.1721 mg·g-1)>PET (0.0951 mg·g-1) after aging. ③ Both crystallinity and surface functional groups played key roles in the adsorption of Cd by microplastics. As for virgin microplastics, crystallinity was negatively correlated with the saturated adsorption capacity of Cd, because the amorphous regions contributed most to Cd adsorption. Aging brought about the decrease in crystallinity and the increase in amorphous regions, which further promoted the oxidation reaction on microplastics. Consequently, oxygen-containing functional groups increased on the surface and eventually expanded the adsorption capacity of Cd by microplastics. Note that certain specific functional groups of various microplastics also had impacts on the adsorption process. These results provide valuable information about the environmental behaviors and interactions of microplastics and heavy metals in nature.
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Affiliation(s)
- Jun-Jie Wang
- Fujian Provincial Engineering Research Center of Rural Waste Recycling Technology, College of Environment and Safety Engineering, Fuzhou University, Fuzhou 350108, China
| | - Xiao-Chen Chen
- Fujian Provincial Engineering Research Center of Rural Waste Recycling Technology, College of Environment and Safety Engineering, Fuzhou University, Fuzhou 350108, China
| | - Quan-da Li
- The Nuclear Industry 247 Brigade of Tianjin North China Geological Exploration Bureau, Tianjin 301800, China
| | - Cheng-Jun Jin
- Fujian Provincial Engineering Research Center of Rural Waste Recycling Technology, College of Environment and Safety Engineering, Fuzhou University, Fuzhou 350108, China
| | - Yi-Jia Huang
- Fujian Provincial Engineering Research Center of Rural Waste Recycling Technology, College of Environment and Safety Engineering, Fuzhou University, Fuzhou 350108, China
| | - Lu-Jian Fan
- College of New Energy and Environment, Jilin University, Changchun 130021, China
| | - Jian-Yu Zhang
- Jiangsu Longchang Chemical Co., Ltd., Rugao 226532, China
| | - Xian-Hua Liu
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Kai-Qin Xu
- Fujian Provincial Engineering Research Center of Rural Waste Recycling Technology, College of Environment and Safety Engineering, Fuzhou University, Fuzhou 350108, China
- Fujian Ospring Technology Development Co., Ltd., Fuzhou 350000, China
- National Institute for Environmental Studies, Tsukuba 305-8506, Japan
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Yang Z, Caldwell JZK, Cummings JL, Ritter A, Kinney JW, Cordes D. Sex Modulates the Pathological Aging Effect on Caudate Functional Connectivity in Mild Cognitive Impairment. Front Psychiatry 2022; 13:804168. [PMID: 35479489 PMCID: PMC9037326 DOI: 10.3389/fpsyt.2022.804168] [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] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 03/14/2022] [Indexed: 11/13/2022] Open
Abstract
Purpose To assess the pathological aging effect on caudate functional connectivity among mild cognitive impairment (MCI) participants and examine whether and how sex and amyloid contribute to this process. Materials and Methods Two hundred and seventy-seven functional magnetic resonance imaging (fMRI) sessions from 163 cognitive normal (CN) older adults and 309 sessions from 139 participants with MCI were included as the main sample in our analysis. Pearson's correlation was used to characterize the functional connectivity (FC) between caudate nuclei and each brain region, then caudate nodal strength was computed to quantify the overall caudate FC strength. Association analysis between caudate nodal strength and age was carried out in MCI and CN separately using linear mixed effect (LME) model with covariates (education, handedness, sex, Apolipoprotein E4, and intra-subject effect). Analysis of covariance was conducted to investigate sex, amyloid status, and their interaction effects on aging with the fMRI data subset having amyloid status available. LME model was applied to women and men separately within MCI group to evaluate aging effects on caudate nodal strength and each region's connectivity with caudate nuclei. We then evaluated the roles of sex and amyloid status in the associations of neuropsychological scores with age or caudate nodal strength. An independent cohort was used to validate the sex-dependent aging effects in MCI. Results The MCI group had significantly stronger age-related increase of caudate nodal strength compared to the CN group. Analyzing women and men separately revealed that the aging effect on caudate nodal strength among MCI participants was significant only for women (left: P = 6.23 × 10-7, right: P = 3.37 × 10-8), but not for men (P > 0.3 for bilateral caudate nuclei). The aging effects on caudate nodal strength were not significantly mediated by brain amyloid burden. Caudate connectivity with ventral prefrontal cortex substantially contributed to the aging effect on caudate nodal strength in women with MCI. Higher caudate nodal strength is significantly related to worse cognitive performance in women but not in men with MCI. Conclusion Sex modulates the pathological aging effects on caudate nodal strength in MCI regardless of amyloid status. Caudate nodal strength may be a sensitive biomarker of pathological aging in women with MCI.
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Affiliation(s)
- Zhengshi Yang
- Cleveland Clinic Lou Ruvo Center for Brain Health, Las Vegas, NV, United States
- Department of Brain Health, University of Nevada Las Vegas, Las Vegas, NV, United States
| | | | - Jeffrey L. Cummings
- Chambers-Grundy Center for Transformative Neuroscience, Department of Brain Health, School of Integrated Health Sciences, University of Nevada Las Vegas, Las Vegas, NV, United States
| | - Aaron Ritter
- Cleveland Clinic Lou Ruvo Center for Brain Health, Las Vegas, NV, United States
| | - Jefferson W. Kinney
- Chambers-Grundy Center for Transformative Neuroscience, Department of Brain Health, School of Integrated Health Sciences, University of Nevada Las Vegas, Las Vegas, NV, United States
| | - Dietmar Cordes
- Cleveland Clinic Lou Ruvo Center for Brain Health, Las Vegas, NV, United States
- Department of Brain Health, University of Nevada Las Vegas, Las Vegas, NV, United States
- Department of Psychology and Neuroscience, University of Colorado, Boulder, CO, United States
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Abdullin KA, Gabdullin MT, Zhumagulov SK, Ismailova GA, Gritsenko LV, Kedruk YY, Mirzaeian M. Stabilization of the Surface of ZnO Films and Elimination of the Aging Effect. Materials (Basel) 2021; 14:ma14216535. [PMID: 34772061 PMCID: PMC8585204 DOI: 10.3390/ma14216535] [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: 09/14/2021] [Revised: 10/17/2021] [Accepted: 10/26/2021] [Indexed: 01/11/2023]
Abstract
Zinc oxide is a promising multifunctional material. The practical use of nano- and polycrystalline ZnO devices faces a serious problem of instability of electrical and luminescent characteristics, due to the adsorption of oxygen by the surface during aging. In this paper, the aging effect in ZnO films and nanorod arrays was studied. It was found that ZnO samples demonstrate different behavior of the degradation process, which corresponds to at least two different types of adsorbing surface sites for O2, where O2 adsorption is of a different nature. The first type of surface sites is rapidly depassivated after hydrogen passivation and the aging effect takes place due to these centers. The second type of surface sites has a stable structure after hydrogen passivation and corresponds to HO-ZnO sites. The XPS components of these sites include the Zn2p3/2 peak at 1022.2 ± 0.2 eV and Zn2p1/2 peak at 1045.2 ± 0.2 eV, with a part of the XPS O1s peak at 531.5 ± 0.3 eV. The annealing transforms the first type of site into the second one, and the subsequent short-term plasma treatment in hydrogen results in steady passivation, where the degradation of characteristics is practically reduced to zero.
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Affiliation(s)
- Khabibulla A. Abdullin
- Department of Physics and Technology, Al-Farabi Kazakh National University, Al-Farabi Ave. 71, Almaty 050040, Kazakhstan; (S.K.Z.); (G.A.I.)
- Institute of Applied Science & Information Technology, Shashkin Str. 40–48, Almaty 050040, Kazakhstan
- Correspondence:
| | | | - Sultan K. Zhumagulov
- Department of Physics and Technology, Al-Farabi Kazakh National University, Al-Farabi Ave. 71, Almaty 050040, Kazakhstan; (S.K.Z.); (G.A.I.)
| | - Guzal A. Ismailova
- Department of Physics and Technology, Al-Farabi Kazakh National University, Al-Farabi Ave. 71, Almaty 050040, Kazakhstan; (S.K.Z.); (G.A.I.)
| | - Lesya V. Gritsenko
- School of General Education, Satbayev University, Almaty 050013, Kazakhstan; (L.V.G.); (Y.Y.K.)
| | - Yevgeniya Y. Kedruk
- School of General Education, Satbayev University, Almaty 050013, Kazakhstan; (L.V.G.); (Y.Y.K.)
| | - Mojtaba Mirzaeian
- School of Computing, Engineering and Physical Sciences, University of the West of Scotland, Paisley PA1 2BE, UK;
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Rubes J, Sipek J, Kopecka V, Musilova P, Vozdova M, Prinosilova P, Topinka J, Pastorkova A, Svecova V, Sram RJ. The effects of age on DNA fragmentation, the condensation of chromatin and conventional semen parameters in healthy nonsmoking men exposed to traffic air pollution. Health Sci Rep 2021; 4:e260. [PMID: 33732896 PMCID: PMC7942397 DOI: 10.1002/hsr2.260] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [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: 07/28/2020] [Revised: 01/04/2021] [Accepted: 01/20/2021] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND Numerous studies have investigated age-based declines in semen traits, but the impact of paternal age on semen parameter values remains inconclusive. OBJECTIVES The aim of this study was to detect an impact of age on semen quality was studied in healthy nonsmoking men exposed to traffic air pollution. METHODS Semen samples from 150 Prague City policemen aged 23 to 63 years were examined for standard semen parameters, sperm DNA fragmentation and high DNA stainability. RESULTS A significant positive correlation was found between age and %DFI (r = .359, P < .001), and negative correlations were found between age and sperm vitality (r = -.247, P < .001), the % acrosome-intact sperm (r = -.202, P = .013) and the % normal sperm heads (r = -.204, P = .012). A weak but significant negative correlation was found for high DNA stainability (% HDS) vs age (r = -.161, P = .050). No significant correlation was detected between male age and the other investigated semen quality parameters. At ages of 23 to 30, 31 to 40, 41 to 50, and 51 to 63 years, the mean %DFI values were 12.7 ± 7.18, 14.7 ± 7.42, 19.6 ± 11.25, and 34.2 ± 15.08, respectively. CONCLUSION Our study shows a strong relationship (P < .001) between the age of men and sperm DNA fragmentation in an occupational cohort at risk of exposure to heavy traffic-related air pollution in a large city center.
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Affiliation(s)
- Jiri Rubes
- Department of Genetics and ReproductionCentral European Institute of Technology‐Veterinary Research InstituteBrnoCzech Republic
| | - Jaroslav Sipek
- Department of Genetics and ReproductionCentral European Institute of Technology‐Veterinary Research InstituteBrnoCzech Republic
| | - Vera Kopecka
- Department of Genetics and ReproductionCentral European Institute of Technology‐Veterinary Research InstituteBrnoCzech Republic
| | - Petra Musilova
- Department of Genetics and ReproductionCentral European Institute of Technology‐Veterinary Research InstituteBrnoCzech Republic
| | - Miluse Vozdova
- Department of Genetics and ReproductionCentral European Institute of Technology‐Veterinary Research InstituteBrnoCzech Republic
| | - Petra Prinosilova
- Department of Genetics and ReproductionCentral European Institute of Technology‐Veterinary Research InstituteBrnoCzech Republic
| | - Jan Topinka
- Department of Genetic Toxicology and EpigeneticsInstitute of Experimental Medicine, Czech Academy of SciencePragueCzech Republic
| | - Anna Pastorkova
- Department of Genetic Toxicology and EpigeneticsInstitute of Experimental Medicine, Czech Academy of SciencePragueCzech Republic
| | - Vlasta Svecova
- Department of Genetic Toxicology and EpigeneticsInstitute of Experimental Medicine, Czech Academy of SciencePragueCzech Republic
| | - Radim J. Sram
- Department of Genetic Toxicology and EpigeneticsInstitute of Experimental Medicine, Czech Academy of SciencePragueCzech Republic
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Wang Z, Rankine L, Bier EA, Mummy D, Lu J, Church A, Tighe RM, Swaminathan A, Huang YCT, Que LG, Mammarappallil JG, Rajagopal S, Driehuys B. Using hyperpolarized 129Xe gas-exchange MRI to model the regional airspace, membrane, and capillary contributions to diffusing capacity. J Appl Physiol (1985) 2021; 130:1398-1409. [PMID: 33734831 DOI: 10.1152/japplphysiol.00702.2020] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [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: 12/28/2022] Open
Abstract
Hyperpolarized 129Xe MRI has emerged as a novel means to evaluate pulmonary function via 3D mapping of ventilation, interstitial barrier uptake, and RBC transfer. However, the physiological interpretation of these measurements has yet to be firmly established. Here, we propose a model that uses the three components of 129Xe gas-exchange MRI to estimate accessible alveolar volume (VA), membrane conductance, and capillary blood volume contributions to DLCO. 129Xe ventilated volume (VV) was related to VA by a scaling factor kV = 1.47 with 95% confidence interval [1.42, 1.52], relative 129Xe barrier uptake (normalized by the healthy reference value) was used to estimate the membrane-specific conductance coefficient kB = 10.6 [8.6, 13.6] mL/min/mmHg/L, whereas normalized RBC transfer was used to calculate the capillary blood volume-specific conductance coefficient kR = 13.6 [11.4, 16.7] mL/min/mmHg/L. In this way, the barrier and RBC transfer per unit volume determined the transfer coefficient KCO, which was then multiplied by image-estimated VA to obtain DLCO. The model was built on a cohort of 41 healthy subjects and 101 patients with pulmonary disorders. The resulting 129Xe-derived DLCO correlated strongly (R2 = 0.75, P < 0.001) with the measured values, a finding that was preserved within each individual disease cohort. The ability to use 129Xe MRI measures of ventilation, barrier uptake, and RBC transfer to estimate each of the underlying constituents of DLCO clarifies the interpretation of these images while enabling their use to monitor these aspects of gas exchange independently and regionally.NEW & NOTEWORTHY The diffusing capacity for carbon monoxide (DLCO) is perhaps one of the most comprehensive physiological measures used in pulmonary medicine. Here, we spatially resolve and estimate its key components-accessible alveolar volume, membrane, and capillary blood volume conductances-using hyperpolarized 129Xe MRI of ventilation, interstitial barrier uptake, and red blood cell transfer. This image-derived DLCO correlates strongly with measured values in 142 subjects with a broad range of pulmonary disorders.
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Affiliation(s)
- Ziyi Wang
- Department of Biomedical Engineering, Duke University, Durham, North Carolina.,Center for In Vivo Microscopy, Duke University Medical Center, Durham, North Carolina
| | - Leith Rankine
- Center for In Vivo Microscopy, Duke University Medical Center, Durham, North Carolina.,Medical Physics Graduate Program, Duke University, Durham, North Carolina
| | - Elianna A Bier
- Department of Biomedical Engineering, Duke University, Durham, North Carolina.,Center for In Vivo Microscopy, Duke University Medical Center, Durham, North Carolina
| | - David Mummy
- Center for In Vivo Microscopy, Duke University Medical Center, Durham, North Carolina
| | - Junlan Lu
- Center for In Vivo Microscopy, Duke University Medical Center, Durham, North Carolina.,Medical Physics Graduate Program, Duke University, Durham, North Carolina
| | - Alex Church
- Center for In Vivo Microscopy, Duke University Medical Center, Durham, North Carolina
| | - Robert M Tighe
- Department of Medicine, Duke University Medical Center, Durham, North Carolina
| | - Aparna Swaminathan
- Division of Pulmonary, Allergy, and Critical Care, Department of Medicine, Duke University Medical Center, Durham, North Carolina
| | - Yuh-Chin T Huang
- Division of Pulmonary, Allergy, and Critical Care, Department of Medicine, Duke University Medical Center, Durham, North Carolina
| | - Loretta G Que
- Division of Pulmonary, Allergy, and Critical Care, Department of Medicine, Duke University Medical Center, Durham, North Carolina
| | | | - Sudarshan Rajagopal
- Department of Medicine, Duke University Medical Center, Durham, North Carolina.,Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, North Carolina
| | - Bastiaan Driehuys
- Department of Biomedical Engineering, Duke University, Durham, North Carolina.,Center for In Vivo Microscopy, Duke University Medical Center, Durham, North Carolina.,Medical Physics Graduate Program, Duke University, Durham, North Carolina.,Department of Radiology, Duke University Medical Center, Durham, North Carolina
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G. Quiles L, Vidal J, Luzi F, Dominici F, Fernández Cuello Á, Castell P. Color Fixation Strategies on Sustainable Poly-Butylene Succinate Using Biobased Itaconic Acid. Polymers (Basel) 2020; 13:E79. [PMID: 33379171 PMCID: PMC7795375 DOI: 10.3390/polym13010079] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [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: 11/26/2020] [Revised: 12/22/2020] [Accepted: 12/23/2020] [Indexed: 02/06/2023] Open
Abstract
Biopo-lybutylene succinate (bioPBS) is gaining attention in the biodegradable polymer market due to its promising properties, such as high biodegradability and processing versatility, representing a potential sustainable replacement for fossil-based commodities. However, there is still a need to enhance its properties for certain applications, with aesthetical and mechanical properties being a challenge. The aim of the present work is to improve these properties by adding selected additives that will confer bioPBS with comparable properties to that of current counterparts such as polypropylene (PP) for specific applications in the automotive and household appliances sectors. A total of thirteen materials have been studied and compared, being twelve biocomposites containing combinations of three different additives: a commercial red colorant, itaconic acid (IA) to enhance color fixation and zirconia (ZrO2) nanoparticles to maintain at least native PBS mechanical properties. The results show that the combination of IA and the coloring agent tends to slightly yellowish the blend due to the absorbance spectra of IA and also to modify the gloss due to the formation of IA nanocrystals that affects light scattering. In addition, for low amounts of IA (4 wt %), Young's Modulus seems to be kept while elongation at break is even raised. Unexpectedly, a strong aging affect was found after four weeks. IA increases the hydrophilic behavior of the samples and thus seems to accelerate the hydrolization of the matrix, which is accompanied by an accused disaggregation of phases and an overall softening and rigidization effect. The addition of low amounts of ZrO2 (2 wt %) seems to provide the desired effect for hardening the surface while almost not affecting the other properties; however, higher amounts tends to form aggregates saturating the compounds. As a conclusion, IA might be a good candidate for color fixing in biobased polymers.
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Affiliation(s)
- Lidia G. Quiles
- Tecnopackaging, Polígono Industrial Empresarium C/Romero Nº, 12, 50720 Zaragoza, Spain
| | - Julio Vidal
- Fundación Aitiip, Polígono Industrial Empresarium C/Romero Nº, 12, 50720 Zaragoza, Spain;
| | - Francesca Luzi
- Department of Civil and Environmental Engineering, University of Perugia, 05100 Terni, Italy; (F.L.); (F.D.)
| | - Franco Dominici
- Department of Civil and Environmental Engineering, University of Perugia, 05100 Terni, Italy; (F.L.); (F.D.)
| | - Ángel Fernández Cuello
- Escuela de Ingeniería y Arquitectura, University of Zaragoza, Av. María de Luna, 3, 50018 Zaragoza, Spain;
| | - Pere Castell
- Fundación Aitiip, Polígono Industrial Empresarium C/Romero Nº, 12, 50720 Zaragoza, Spain;
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Aravind Shanmugasundaram S, Razmi J, Mian MJ, Ladani L. Mechanical Anisotropy and Surface Roughness in Additively Manufactured Parts Fabricated by Stereolithography (SLA) Using Statistical Analysis. Materials (Basel) 2020; 13:E2496. [PMID: 32486137 DOI: 10.3390/ma13112496] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 05/24/2020] [Accepted: 05/27/2020] [Indexed: 11/28/2022]
Abstract
In this study, the degree of mechanical anisotropy was investigated through tensile testing of specimens built in different orientations and designed according to the ASTM D638 standard. The mechanical properties that were evaluated include Young’s modulus, ultimate tensile strength (UTS), and percentage elongation. Additionally, physical properties, such as mean surface roughness (Ra), density and dimension of the cross-sectional area, were also measured. These properties were then compared with the available standard data to see how SLA performs comparing to the traditional manufacturing methods. The obtained modulus of elasticity and UTS values of the printed samples were 2481 ± 50 MPa and 51.9 ± 1.3 MPa respectively, which were very similar to the standard data (2550 and 52 MPa, respectively) as provided by the material suppliers. The percentage elongation values (4.8% ± 0.4%) were a bit lower than the expected value of 6%. However, the surfaces of all the printed samples were quite smooth, with a surface roughness range of 2.28 ± 0.59 µm. A design of experiments was created to study the influence of the independent variables such as build orientation and angular orientation on the mechanical properties. Extensive statistical analysis, using the Taguchi method and analysis of variance (ANOVA), was performed to examine the effect of these independent variables on the mechanical properties. The SLA printed parts can be classified as isotropic since the build orientation and the angular orientation did not have a statistically significant impact on the mechanical properties. The effect of aging on the mechanical properties was also evaluated and it shows that the specimens that had been aged for a longer time resulted in superior mechanical properties. For example, the UTS increased from 24 to 54 MPa when the sample aligned parallel to the XY plane was aged from 1 week to 6 months, respectively. This significant increase implies that aging has a substantial effect on the mechanical properties of the parts fabricated by stereolithography. The resin used for this study, Visijet Sl Clear, produced very consistent mechanical properties in different directions.
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11
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Ra HS, Lee AY, Kwak DH, Jeong MH, Lee JS. Dual-Gate Black Phosphorus Field-Effect Transistors with Hexagonal Boron Nitride as Dielectric and Passivation Layers. ACS Appl Mater Interfaces 2018; 10:925-932. [PMID: 29256593 DOI: 10.1021/acsami.7b16809] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Two-dimensional black phosphorus (BP) has attracted much attention recently because of its applicability in high-performance electronic and optoelectronic devices. BP field-effect transistors (FETs) with a tunable band gap (0.3-1.5 eV) have demonstrated a high on-off current ratio and a high hole mobility with an ambipolar behavior in global-gated devices. However, local-gated BP FETs for integrated circuits have been reported with only p-type behaviors and a low on-current compared with global-gated BP FETs. Furthermore, BP, which is not stable in air, forms sharp spikes on its surface when exposed to humid air. This phenomenon plays a role in accelerating the degradation of the electrical properties of BP devices, which can occur even within a day. In this paper, we first demonstrate the origin of transport limitations of local-gated BP FETs by comparing the transport properties of hexagonal boron nitride (h-BN)-based device architectures with those of a bottom-gated BP FET on a Si/SiO2 substrate. By using h-BN as passivation and dielectric layers, BP FETs with a low gate operating voltage were fabricated with two different transistor geometries: top-gated and bottom-gated FETs. The highest mobility extracted from the global-gated BP FETs was 249 cm2 V-1 s-1 with a subthreshold swing of 848 mV dec-1.
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Affiliation(s)
- Hyun-Soo Ra
- Department of Energy Science and Engineering, DGIST , Daegu 42988, Republic of Korea
| | - A-Young Lee
- Department of Energy Science and Engineering, DGIST , Daegu 42988, Republic of Korea
| | - Do-Hyun Kwak
- Department of Energy Science and Engineering, DGIST , Daegu 42988, Republic of Korea
| | - Min-Hye Jeong
- Department of Energy Science and Engineering, DGIST , Daegu 42988, Republic of Korea
| | - Jong-Soo Lee
- Department of Energy Science and Engineering, DGIST , Daegu 42988, Republic of Korea
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12
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Wei Z, Xu J, Liu P, Chen L, Li W, van Zijl P, Lu H. Quantitative assessment of cerebral venous blood T 2 in mouse at 11.7T: Implementation, optimization, and age effect. Magn Reson Med 2017; 80:521-528. [PMID: 29271045 DOI: 10.1002/mrm.27046] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [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: 08/18/2017] [Revised: 10/30/2017] [Accepted: 11/20/2017] [Indexed: 12/12/2022]
Abstract
PURPOSE To develop a non-contrast-agent MRI technique to quantify cerebral venous T2 in mice. METHODS We implemented and optimized a T2 -relaxation-under-spin-tagging (TRUST) sequence on an 11.7 Tesla animal imaging system. A flow-sensitive-alternating-inversion-recovery (FAIR) module was used to generate control and label images, pair-wise subtraction of which yielded blood signals. Then, a T2 -preparation module was applied to produce T2 -weighted images, from which blood T2 was quantified. We conducted a series of technical studies to optimize the imaging slice position, inversion slab thickness, post-labeling delay (PLD), and repetition time. We also performed three physiological studies to examine the venous T2 dependence on hyperoxia (N = 4), anesthesia (N = 3), and brain aging (N = 5). RESULTS Our technical studies suggested that, for efficient data acquisition with minimal bias in estimated T2 , a preferred TRUST protocol was to place the imaging slice at the confluence of sagittal sinuses with an inversion-slab thickness of 2.5-mm, a PLD of 1000 ms and a repetition time of 3.5 s. Venous T2 values under normoxia and hyperoxia (inhaling pure oxygen) were 26.9 ± 1.7 and 32.3 ± 2.2 ms, respectively. Moreover, standard isoflurane anesthesia resulted in a higher venous T2 compared with dexmedetomidine anesthesia (N = 3; P = 0.01) which is more commonly used in animal functional MRI studies to preserve brain function. Venous T2 exhibited a decrease with age (N = 5; P < 0.001). CONCLUSION We have developed and optimized a noninvasive method to quantify cerebral venous blood T2 in mouse at 11.7 T. This method may prove useful in studies of brain physiology and pathophysiology in animal models. Magn Reson Med 80:521-528, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Zhiliang Wei
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, Maryland, USA
| | - Jiadi Xu
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, Maryland, USA
| | - Peiying Liu
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, Maryland, USA
| | - Lin Chen
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, Maryland, USA
| | - Wenbo Li
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, Maryland, USA
| | - Peter van Zijl
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, Maryland, USA
| | - Hanzhang Lu
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, Maryland, USA.,Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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13
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Noda Y, Zomorrodi R, Cash RFH, Barr MS, Farzan F, Rajji TK, Chen R, Daskalakis ZJ, Blumberger DM. Characterization of the influence of age on GABA A and glutamatergic mediated functions in the dorsolateral prefrontal cortex using paired-pulse TMS-EEG. Aging (Albany NY) 2017; 9:556-572. [PMID: 28209926 PMCID: PMC5361681 DOI: 10.18632/aging.101178] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [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: 12/18/2016] [Accepted: 02/09/2017] [Indexed: 11/27/2022]
Abstract
Gamma-aminobutyric acid (GABA)ergic and glutamatergic neurotransmissions in the prefrontal cortex decreases with age. Further, cognitive function mediated through the dorsolateral prefrontal cortex (DLPFC) also declines with age. Although neuroimaging studies have demonstrated decreased levels of these substances, direct neurophysiological data investigating the effect of aging in the DLPFC in human subjects is lacking. The advent of transcranial magnetic stimulation (TMS) combined with electroencephalography (EEG) has allowed for the assessment of functional neurotransmission in vivo. In the present study, we examined short interval intracortical inhibition (SICI) and intracortical facilitation (ICF) in a group of older adults (> 60 yrs) to evaluate the strength of GABAA and glutamate-mediated neurotransmission in the DLPFC, compared to younger adults (18-59 yrs). Older adults showed an increase of amplitude of N100 by the SICI paradigm, while N45 amplitude was increased and N100 amplitude was decreased by ICF. Moreover, these modulations significantly correlated with age. Our findings provide evidence for age-related alterations of excitatory and inhibitory functions in the prefrontal cortex in healthy adults. Future studies may aim to explore these neurophysiological relationships in the DLPFC in pathological forms of aging that affect cortical functioning such as mild cognitive impairment and Alzheimer's disease.
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Affiliation(s)
- Yoshihiro Noda
- Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health, Toronto, Ontario, M6J 1H4, Canada.,Department of Psychiatry, University of Toronto, Toronto, Ontario, M5T 1R8, Canada
| | - Reza Zomorrodi
- Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health, Toronto, Ontario, M6J 1H4, Canada
| | - Robin F H Cash
- Monash Alfred Psychiatry Research Centre, Monash University Central Clinical School and the Alfred, Melbourne 3004, Australia
| | - Mera S Barr
- Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health, Toronto, Ontario, M6J 1H4, Canada.,Department of Psychiatry, University of Toronto, Toronto, Ontario, M5T 1R8, Canada.,Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8, Canada
| | - Faranak Farzan
- Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health, Toronto, Ontario, M6J 1H4, Canada.,Department of Psychiatry, University of Toronto, Toronto, Ontario, M5T 1R8, Canada.,Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8, Canada
| | - Tarek K Rajji
- Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health, Toronto, Ontario, M6J 1H4, Canada.,Department of Psychiatry, University of Toronto, Toronto, Ontario, M5T 1R8, Canada.,Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8, Canada
| | - Robert Chen
- Division of Neurology, Department of Medicine, University of Toronto, Division of Brain, Imaging and Behaviour - Systems Neuroscience, Krembil Research Institute, University Health Network, Toronto, M5T 2S8, Ontario, Canada
| | - Zafiris J Daskalakis
- Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health, Toronto, Ontario, M6J 1H4, Canada.,Department of Psychiatry, University of Toronto, Toronto, Ontario, M5T 1R8, Canada.,Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8, Canada
| | - Daniel M Blumberger
- Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health, Toronto, Ontario, M6J 1H4, Canada.,Department of Psychiatry, University of Toronto, Toronto, Ontario, M5T 1R8, Canada.,Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8, Canada
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Behzad K, Mat Yunus WM, Talib ZA, Zakaria A, Bahrami A. Preparation and Thermal Characterization of Annealed Gold Coated Porous Silicon. Materials (Basel) 2012; 5:157-68. [PMID: 28817037 DOI: 10.3390/ma5010157] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/09/2011] [Revised: 11/22/2011] [Accepted: 11/24/2011] [Indexed: 11/17/2022]
Abstract
Porous silicon (PSi) layers were formed on a p-type Si wafer. Six samples were anodised electrically with a 30 mA/cm² fixed current density for different etching times. The samples were coated with a 50-60 nm gold layer and annealed at different temperatures under Ar flow. The morphology of the layers, before and after annealing, formed by this method was investigated by scanning electron microscopy (SEM). Photoacoustic spectroscopy (PAS) measurements were carried out to measure the thermal diffusivity (TD) of the PSi and Au/PSi samples. For the Au/PSi samples, the thermal diffusivity was measured before and after annealing to study the effect of annealing. Also to study the aging effect, a comparison was made between freshly annealed samples and samples 30 days after annealing.
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