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Lee HJ, Choi JW. Association between waist circumference change after smoking cessation and incidence of hypertension in Korean adults. Public Health 2024; 229:73-79. [PMID: 38402666 DOI: 10.1016/j.puhe.2024.01.028] [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: 08/09/2023] [Revised: 12/14/2023] [Accepted: 01/26/2024] [Indexed: 02/27/2024]
Abstract
OBJECTIVES This study investigates the association between smoking cessation and hypertension incidence, as well as the association between waist circumference change after smoking cessation and hypertension incidence. STUDY DESIGN This was a nationwide population-based cohort study. METHODS We used the Korean Health Screening Cohort data and included 158,505 participants who had undergone two or more health examinations between 2008 and 2011, with follow-ups throughout 2019. Smoking cessation and waist changes were captured based on difference between first and follow-up screening dates. Hazard ratio (HR) and 95% confidence interval (CI) for hypertension risk were estimated using multivariable Cox proportional hazard regression models. RESULTS There were 31,270 cases of hypertension during a median follow-up of 8.50 years. After adjusting for potential confounding factors, HR for hypertension were 1.01 (95% CI: 0.97-1.05), 0.91 (95% CI: 0.87-0.95), and 0.88 (95% CI: 0.85-0.91) for recent quitters, long-term quitters, and non-smokers, respectively, compared with current smokers. HR for hypertension, compared with current smokers, were 0.89 (95% CI: 0.84-0.94), 0.91 (95% CI: 0.85-0.97), and 0.99 (95% CI: 0.91-1.08) for long-term quitters with no waist gain, long-term quitters with waist gain of 0.1-5.0 cm, and long-term quitters with waist gain of ≥5.0 cm, respectively. CONCLUSIONS Long-term smoking cessation was significantly associated with decreased risk of hypertension, and long-term smoking cessation with no waist gain or less than 5.0 cm of waist gain was significantly associated with decreased risk of hypertension. However, more than 5.0 cm of waist gain can attenuate the effect of long-term smoking cessation on lowering the risk of hypertension.
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Affiliation(s)
- H J Lee
- Department of Statistics and Data Science, Yonsei University, Seoul, Republic of Korea
| | - J W Choi
- Health Insurance Research Institute, National Health Insurance Service, Wonju, Republic of Korea.
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Choi JW, Park JW, Choi WJ. Effects of hip joint kinematics on the effective pelvis stiffness and hip impact force during simulated sideways falls. J Biomech 2024; 162:111885. [PMID: 38039920 DOI: 10.1016/j.jbiomech.2023.111885] [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: 03/29/2023] [Revised: 11/21/2023] [Accepted: 11/23/2023] [Indexed: 12/03/2023]
Abstract
Improved understanding is required on how hip fracture risk is influenced by landing configuration. We examined how hip impact dynamics was affected by hip joint kinematics during simulated sideways falls. Twelve young adults (7 males, 5 females) of mean age 23.5 (SD = 1.5) years, participated in pelvis release experiments. Trials were acquired with the hip flexed 15° and 30° for each of three hip rotations: +15° ("external rotation"), 0°, and -15° ("internal rotation"). During falls, force-deformation data of the pelvis were recorded. Outcome variables included the peak hip impact force (Fexperimental) and effective stiffness of the pelvis (k1st, ksecant, and kms) determined with different methods suggested in literature, and predicted hip impact force during a fall from standing height (F1st, Fsecant and Fms). The two-way repeated-measures ANOVA was used to test whether these variables were associated with hip joint angles. The Fexperimental, ksecant and Fsecant were associated with hip rotation (F = 5.587, p = 0.005; F = 9.278, p < 0.0005; F = 5.778, p = 0.004, respectively), and 15 %, 31 % and 17 % smaller in 15° external than internal rotation (848 versus 998 N; 24.6 versus 35.6 kN/m; 2,637 versus 3,170 N, respectively). However, none of the outcome variables were associated with hip flexion (p > 0.05). Furthermore, there were no interactions between the hip rotation and flexion for all outcome variables (p > 0.05). Our results provide insights on hip impact dynamics, which may help improve a hip model to assess hip fracture risk during a fall.
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Affiliation(s)
- J W Choi
- Injury Prevention and Biomechanics Laboratory, Department of Physical Therapy, Yonsei University, Wonju, Gangwon-do, South Korea
| | - J W Park
- Injury Prevention and Biomechanics Laboratory, Department of Physical Therapy, Yonsei University, Wonju, Gangwon-do, South Korea
| | - W J Choi
- Injury Prevention and Biomechanics Laboratory, Department of Physical Therapy, Yonsei University, Wonju, Gangwon-do, South Korea.
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Park SM, Yoon HG, Lee DB, Choi JW, Kwon HY, Won C. Topological magnetic structure generation using VAE-GAN hybrid model and discriminator-driven latent sampling. Sci Rep 2023; 13:20377. [PMID: 37989882 PMCID: PMC10663506 DOI: 10.1038/s41598-023-47866-3] [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: 09/04/2023] [Accepted: 11/19/2023] [Indexed: 11/23/2023] Open
Abstract
Recently, deep generative models using machine intelligence are widely utilized to investigate scientific systems by generating scientific data. In this study, we experiment with a hybrid model of a variational autoencoder (VAE) and a generative adversarial network (GAN) to generate a variety of plausible two-dimensional magnetic topological structure data. Due to the topological properties in the system, numerous and diverse metastable magnetic structures exist, and energy and topological barriers separate them. Thus, generating a variety of plausible spin structures avoiding those barrier states is a challenging problem. The VAE-GAN hybrid model can present an effective approach to this problem because it brings the advantages of both VAE's diversity and GAN's fidelity. It allows one to perform various applications including searching a desired sample from a variety of valid samples. Additionally, we perform a discriminator-driven latent sampling (DDLS) using our hybrid model to improve the quality of generated samples. We confirm that DDLS generates various plausible data with large coverage, following the topological rules of the target system.
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Affiliation(s)
- S M Park
- Department of Physics, Kyung Hee University, Seoul, 02447, South Korea
| | - H G Yoon
- Department of Physics, Kyung Hee University, Seoul, 02447, South Korea
| | - D B Lee
- Department of Physics, Kyung Hee University, Seoul, 02447, South Korea
- Department of Battery-Smart Factory, Korea University, Seoul, 02841, South Korea
| | - J W Choi
- Center for Spintronics, Korea Institute of Science and Technology, Seoul, 02792, South Korea
| | - H Y Kwon
- Center for Spintronics, Korea Institute of Science and Technology, Seoul, 02792, South Korea.
| | - C Won
- Department of Physics, Kyung Hee University, Seoul, 02447, South Korea.
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Mearaj S, Ajaz AM, Kim TM, Choi JW. Bioactive and Hemocompatible PLA/Lignin Bio-Composites: Assessment of In Vitro Antioxidant Activity for Biomedical Applications. ACS Appl Bio Mater 2023; 6:3648-3660. [PMID: 37584640 DOI: 10.1021/acsabm.3c00210] [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: 08/17/2023]
Abstract
In this study, acetylated soda lignin (ASL) and non-acetylated soda lignin (SL) were extruded with PLA in different concentrations to fabricate antioxidant polylactic acid (PLA)/lignin composites for potential biomedical applications. After lignin acetylation, good compatibility was observed between PLA and lignin in scanning electron microscopy images. All the PLA/ASL composites displayed higher mechanical properties than PLA/SL composites. PLA/ASL5 displayed the highest mechanical characteristics with elongation at break of 10% and tensile strength of 57 MPa, while PLA/SL15 and PLA/SL20 demonstrated superior UV-blocking potential with UV transmittance less than 10%. Addition of ASL in PLA lead to an increase in the hydrophobic character, with all the PLA/ASL displaying a higher water contact angle. The antioxidant test using 2,2-diphenyl-1-picrylhydrazyl assay showed that PLA/SL composites rendered superior radical scavenging activity (RSA), with PLA/SL20 composites displaying an RSA of 80%. Furthermore, in vitro antioxidant activity and cytocompatibility were analyzed using human colon cancer cells (HCT-15) and gastric epithelial cells (NCC-24). In vitro antioxidant activity, evaluated by H2O2 exposure was confirmed by a live/dead assay. PLA/SL composites protected both types of cells from oxidative stress. In addition, all PLA/SL and PLA/ASL composites promoted cell proliferation compared to PLA. PLA/SL5 and PLA/SL10 displayed the highest cell proliferation of all composites. Lastly, all PLA/SL and PLA/ASL composites had a hemoglobin release less than 2%. The antioxidant properties, cytocompatibility, and hemocompatibility of lignin/PLA demonstrated in our study indicate that these lignin/PLA composites possess the desirable attributes for potential biomedical applications.
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Affiliation(s)
- Sadaf Mearaj
- Graduate School of International Agricultural Technology, Department of Green Eco System Engineering, Seoul National University, Pyeongchang 25354, Gangwon-do, South Korea
| | - Ahmed Muhammad Ajaz
- Graduate School of International Agricultural Technology, Department of Green Eco System Engineering, Seoul National University, Pyeongchang 25354, Gangwon-do, South Korea
| | - Tae Min Kim
- Graduate School of International Agricultural Technology, Department of Green Eco System Engineering, Seoul National University, Pyeongchang 25354, Gangwon-do, South Korea
- Institute of Green-Bio Science and Technology, Seoul National University, Pyeongchang 25354, Gangwon-do, South Korea
| | - Joon Weon Choi
- Graduate School of International Agricultural Technology, Department of Green Eco System Engineering, Seoul National University, Pyeongchang 25354, Gangwon-do, South Korea
- Institute of Green-Bio Science and Technology, Seoul National University, Pyeongchang 25354, Gangwon-do, South Korea
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Lee DB, Yoon HG, Park SM, Choi JW, Chen G, Kwon HY, Won C. Super-resolution of magnetic systems using deep learning. Sci Rep 2023; 13:11526. [PMID: 37460591 DOI: 10.1038/s41598-023-38335-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 07/06/2023] [Indexed: 07/20/2023] Open
Abstract
We construct a deep neural network to enhance the resolution of spin structure images formed by spontaneous symmetry breaking in the magnetic systems. Through the deep neural network, an image is expanded to a super-resolution image and reduced to the original image size to be fitted with the input feed image. The network does not require ground truth images in the training process. Therefore, it can be applied when low-resolution images are provided as training datasets, while high-resolution images are not obtainable due to the intrinsic limitation of microscope techniques. To show the usefulness of the network, we train the network with two types of simulated magnetic structure images; one is from self-organized maze patterns made of chiral magnetic structures, and the other is from magnetic domains separated by walls that are topological defects of the system. The network successfully generates high-resolution images highly correlated with the exact solutions in both cases. To investigate the effectiveness and the differences between datasets, we study the network's noise tolerance and compare the networks' reliabilities. The network is applied with experimental data obtained by magneto-optical Kerr effect microscopy and spin-polarized low-energy electron microscopy.
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Affiliation(s)
- D B Lee
- Department of Physics, Kyung Hee University, Seoul, 02447, South Korea
- Department of Battery-Smart Factory, Korea University, Seoul, 02841, South Korea
| | - H G Yoon
- Department of Physics, Kyung Hee University, Seoul, 02447, South Korea
| | - S M Park
- Department of Physics, Kyung Hee University, Seoul, 02447, South Korea
| | - J W Choi
- Center for Spintronics, Korea Institute of Science and Technology, Seoul, 02792, South Korea
| | - G Chen
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing, 210093, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing, 210093, China
| | - H Y Kwon
- Center for Spintronics, Korea Institute of Science and Technology, Seoul, 02792, South Korea.
| | - C Won
- Department of Physics, Kyung Hee University, Seoul, 02447, South Korea.
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Han M, Choi JW, Jung WS, Lee JS. Isolated posterior inferior cerebellar artery dissection with ischaemic stroke: evaluating the radiological features and diagnostic feasibility of high-resolution vessel wall imaging. Clin Radiol 2022; 77:584-591. [PMID: 35676104 DOI: 10.1016/j.crad.2022.05.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 05/06/2022] [Indexed: 11/29/2022]
Abstract
AIM To evaluate the radiological features of isolated posterior inferior cerebellar artery dissection (PICAD) and the feasibility of using high-resolution vessel-wall imaging (HR-VWI) for diagnosing PICAD. MATERIALS AND METHODS Three hundred and nine patients with arterial dissection involving the posterior cerebral circulation, who underwent HR-VWI between March 2012 and July 2019 were reviewed retrospectively. Among them, 44 patients (14.2%) were diagnosed with isolated PICAD in consensus among a neuroradiologist, a neurointerventionist, and a neurologist. Two neuroradiologists reviewed the vessel wall images independently for evidence of dissection (dissection flap, outer diameter enlargement on T2-weighted imaging [WI], mural haematoma). Diagnostic confidence was also scored on a five-point scale. Intra- and interobserver agreement for diagnosing PICAD and detecting evidence of dissection were evaluated. RESULTS Dissection flaps were seen on T2WI in all cases (100%) and on contrast-enhanced T1WI in 34 patients (79.1%). Outer diameter enlargement of the steno-occlusive lesions on angiography was detected in most cases (97.7%). A mural haematoma was detected on three-dimensional (3D) contrast-enhanced motion-sensitised driven-equilibrium T1WI in 97.1% of the cases. The mean diagnostic confidence score derived by two neuroradiologists was 4.72. The two reviewers showed substantial to almost perfect agreement (weighted kappa coefficient: 0.62-0.97). CONCLUSION Use of HR-VWI as a diagnostic tool for PICAD is feasible, and a dissection flap with outer wall enlargement on HR-T2WI allows confident dissection diagnosis. The present data suggest that PICAD might be considered as a stroke aetiology in patients with unexplained ischaemic stroke in the PICA territory, and that PICA evaluation with HR-VWI is both necessary and feasible.
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Affiliation(s)
- M Han
- Department of Radiology, Ajou University School of Medicine, Ajou University Hospital, Suwon, Republic of Korea; Department of Radiology, Graduate School of Kangwon National University, Chuncheon, Republic of Korea
| | - J W Choi
- Department of Radiology, Ajou University School of Medicine, Ajou University Hospital, Suwon, Republic of Korea.
| | - W S Jung
- Department of Radiology, Ajou University School of Medicine, Ajou University Hospital, Suwon, Republic of Korea; Department of Radiology, Graduate School of Kangwon National University, Chuncheon, Republic of Korea
| | - J S Lee
- Department of Neurology, Ajou University School of Medicine, Ajou University Hospital, Suwon, Republic of Korea
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Kim KH, Jin X, Ji A, Aui A, Mba-Wright M, Yoo CJ, Choi JW, Ha JM, Kim CS, Yoo CG, Choi JW. Catalytic conversion of waste corrugated cardboard into lactic acid using lanthanide triflates. Waste Manag 2022; 144:41-48. [PMID: 35306464 DOI: 10.1016/j.wasman.2022.03.005] [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: 11/22/2021] [Revised: 03/02/2022] [Accepted: 03/08/2022] [Indexed: 06/14/2023]
Abstract
The efficient strategy for waste conversion and resource recovery is of great interest in the sustainable bioeconomy context. This work reports on the catalytic upcycling of waste corrugated cardboard (WCC) into lactic acid using lanthanide triflates catalysts. WCC, a primary contributor to municipal solid wastes, has been viewed as a feedstock for producing a wide range of renewable products. Hydrothermal conversion of WCC was carried out in the presence of several lanthanide triflates. The reaction with erbium(III) triflate (Er(OTf)3) and ytterbium(III) triflate (Yb(OTf)3) resulted in high lactic acid yields, 65.5 and 64.3 mol%, respectively. In addition, various monomeric phenols were readily obtained as a co-product stream, opening up opportunities in waste management and resource recovery. Finally, technoeconomic analysis was conducted based on the experimental results, which suggests a significant economic benefit of chemocatalytic upcycling of WCC into lactic acid.
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Affiliation(s)
- Kwang Ho Kim
- Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea; Department of Wood Science, University of British Columbia, 2424 Main Mall, Vancouver, BC V6T 1Z4, Canada.
| | - Xuanjun Jin
- Graduate School of International Agricultural Technology, Seoul National University, Pyeongchang 25354, Republic of Korea
| | - Anqi Ji
- Department of Chemical Engineering, State University of New York College of Environmental Science and Forestry, Syracuse, NY 13210, USA
| | - Alvina Aui
- Department of Mechanical Engineering, Iowa State University, Ames, IA 50010, USA
| | - Mark Mba-Wright
- Department of Mechanical Engineering, Iowa State University, Ames, IA 50010, USA
| | - Chun-Jae Yoo
- Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
| | - Jae-Wook Choi
- Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
| | - Jeong-Myeong Ha
- Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
| | - Chang Soo Kim
- Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
| | - Chang Geun Yoo
- Department of Chemical Engineering, State University of New York College of Environmental Science and Forestry, Syracuse, NY 13210, USA; The Michael M. Szwarc Polymer Research Institute, Syracuse, NY 13210, USA
| | - Joon Weon Choi
- Graduate School of International Agricultural Technology, Seoul National University, Pyeongchang 25354, Republic of Korea
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Bang SW, Choi S, Jin X, Jung SE, Choi JW, Seo JS, Kim J. Transcriptional activation of rice CINNAMOYL-CoA REDUCTASE 10 by OsNAC5, contributes to drought tolerance by modulating lignin accumulation in roots. Plant Biotechnol J 2022; 20:736-747. [PMID: 34786790 PMCID: PMC8989508 DOI: 10.1111/pbi.13752] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 11/09/2021] [Accepted: 11/11/2021] [Indexed: 05/17/2023]
Abstract
Drought is a common abiotic stress for terrestrial plants and often affects crop development and yield. Recent studies have suggested that lignin plays a crucial role in plant drought tolerance; however, the underlying molecular mechanisms are still largely unknown. Here, we report that the rice (Oryza sativa) gene CINNAMOYL-CoA REDUCTASE 10 (OsCCR10) is directly activated by the OsNAC5 transcription factor, which mediates drought tolerance through regulating lignin accumulation. CCR is the first committed enzyme in the monolignol synthesis pathway, and the expression of 26 CCR genes was observed to be induced in rice roots under drought. Subcellular localisation assays revealed that OsCCR10 is a catalytically active enzyme that is localised in the cytoplasm. The OsCCR10 transcript levels were found to increase in response to abiotic stresses, such as drought, high salinity, and abscisic acid (ABA), and transcripts were detected in roots at all developmental stages. In vitro enzyme activity and in vivo lignin composition assay suggested that OsCCR10 is involved in H- and G-lignin biosynthesis. Transgenic rice plants overexpressing OsCCR10 showed improved drought tolerance at the vegetative stages of growth, as well as higher photosynthetic efficiency, lower water loss rates, and higher lignin content in roots compared to non-transgenic (NT) controls. In contrast, CRISPR/Cas9-mediated OsCCR10 knock-out mutants exhibited reduced lignin accumulation in roots and less drought tolerance. Notably, transgenic rice plants with root-preferential overexpression of OsCCR10 exhibited higher grain yield than NT controls plants under field drought conditions, indicating that lignin biosynthesis mediated by OsCCR10 contributes to drought tolerance.
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Affiliation(s)
- Seung Woon Bang
- Crop Biotechnology InstituteGreenBio Science and TechnologySeoul National UniversityPyeongchangKorea
| | - Seowon Choi
- Crop Biotechnology InstituteGreenBio Science and TechnologySeoul National UniversityPyeongchangKorea
- Graduate School of International Agricultural TechnologySeoul National UniversityPyeongchangKorea
| | - Xuanjun Jin
- Graduate School of International Agricultural TechnologySeoul National UniversityPyeongchangKorea
- Institute of Green Eco EngineeringGreenBio Science and TechnologySeoul National UniversityPyeongchangKorea
| | - Se Eun Jung
- Crop Biotechnology InstituteGreenBio Science and TechnologySeoul National UniversityPyeongchangKorea
- Graduate School of International Agricultural TechnologySeoul National UniversityPyeongchangKorea
| | - Joon Weon Choi
- Graduate School of International Agricultural TechnologySeoul National UniversityPyeongchangKorea
- Institute of Green Eco EngineeringGreenBio Science and TechnologySeoul National UniversityPyeongchangKorea
| | - Jun Sung Seo
- Crop Biotechnology InstituteGreenBio Science and TechnologySeoul National UniversityPyeongchangKorea
| | - Ju‐Kon Kim
- Crop Biotechnology InstituteGreenBio Science and TechnologySeoul National UniversityPyeongchangKorea
- Graduate School of International Agricultural TechnologySeoul National UniversityPyeongchangKorea
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Hwang H, Ajaz AM, Choi JW. A study on activation mechanism in perspective of lignin structures and applicability of lignin-derived activated carbons for pollutant absorbent and supercapacitor electrode. Chemosphere 2022; 291:133045. [PMID: 34843833 DOI: 10.1016/j.chemosphere.2021.133045] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 11/04/2021] [Accepted: 11/21/2021] [Indexed: 06/13/2023]
Abstract
In this study activated carbons were produced from the biorefinery waste lignin (Asian lignin (AL) USA & Inbicon lignin (IL) Denmark) to evaluate their potential in waste water treatment and as energy storage devices. These products were studied for their surface characteristics as a function of reaction temperature, time, and catalyst loading accordingly. Under the conditions with a temperature lower than 750 °C and within a reaction time of 1 h, the catalytic reaction of alkali-carbon bonding occurred from the external surface, and a turbostratic disorder structure with a large aromatic ring system was formed. More severe reaction conditions accelerated the volatile release of de-alkylated aromatics such as benzene and naphthalene, along with structure and surface collapse. The maximum BET surface area of 2782 m2/g was obtained at 750 °C, 2 h and catalyst ratio of 4. Lignin-derived activated carbon was more efficient for the removal of organic pollutants (<50% adsorption capacity) rather than heavy metals (adsorption capacity >90%) due to interaction of π-π bonding. Furthermore, the activated carbon has a potential to be used as a supercapacitor electrode with high specific capacitance (214.0 F/g AL lignin) and an excellent cyclic stability (95% of their initial capacity). The results of this study demonstrate that lignin is an attractive precursor to produce activated carbons with diverse applications both as biosorbent and as a carbon electrode material even so with acceptable performance.
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Affiliation(s)
- Hyewon Hwang
- Department of Forest Sciences, Seoul National University, 599 Gwanak-ro, Gwanak-gu, Seoul, 08826, South Korea
| | - Ahmed Muhammad Ajaz
- Graduate School of International Agricultural Technology and Institute of Green-Bio Science and Technology, Seoul National University, Pyeongchang, Gangwon-do, 25354, South Korea
| | - Joon Weon Choi
- Graduate School of International Agricultural Technology and Institute of Green-Bio Science and Technology, Seoul National University, Pyeongchang, Gangwon-do, 25354, South Korea.
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Lee DB, Yoon HG, Park SM, Choi JW, Kwon HY, Won C. Estimating the effective fields of spin configurations using a deep learning technique. Sci Rep 2021; 11:22937. [PMID: 34824339 PMCID: PMC8616938 DOI: 10.1038/s41598-021-02374-0] [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: 09/24/2021] [Accepted: 11/15/2021] [Indexed: 11/09/2022] Open
Abstract
The properties of complicated magnetic domain structures induced by various spin-spin interactions in magnetic systems have been extensively investigated in recent years. To understand the statistical and dynamic properties of complex magnetic structures, it is crucial to obtain information on the effective field distribution over the structure, which is not directly provided by magnetization. In this study, we use a deep learning technique to estimate the effective fields of spin configurations. We construct a deep neural network and train it with spin configuration datasets generated by Monte Carlo simulation. We show that the trained network can successfully estimate the magnetic effective field even though we do not offer explicit Hamiltonian parameter values. The estimated effective field information is highly applicable; it is utilized to reduce noise, correct defects in the magnetization data, generate spin configurations, estimate external field responses, and interpret experimental images.
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Affiliation(s)
- D B Lee
- Department of Physics, Kyung Hee University, Seoul, 02447, South Korea
| | - H G Yoon
- Department of Physics, Kyung Hee University, Seoul, 02447, South Korea
| | - S M Park
- Department of Physics, Kyung Hee University, Seoul, 02447, South Korea
| | - J W Choi
- Center for Spintronics, Korea Institute of Science and Technology, Seoul, 02792, South Korea
| | - H Y Kwon
- Center for Spintronics, Korea Institute of Science and Technology, Seoul, 02792, South Korea.
| | - C Won
- Department of Physics, Kyung Hee University, Seoul, 02447, South Korea.
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Hwang H, Lee JH, Ahmed MA, Choi JW. Evaluation of pyrochar and hydrochar derived activated carbons for biosorbent and supercapacitor materials. J Environ Manage 2021; 298:113436. [PMID: 34358935 DOI: 10.1016/j.jenvman.2021.113436] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [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: 04/11/2021] [Revised: 07/07/2021] [Accepted: 07/28/2021] [Indexed: 06/13/2023]
Abstract
This study investigated effects of different thermal processes on characteristics of activated carbon to produce efficient biosorbents or supercapacitors using biomass resources. Pyrolysis char and hydrochar obtained from woody biomass were used as precursors for activated carbon under different atmospheric conditions (N2 and air). In order to provide functional groups on the carbon surface, activated carbon under N2 condition was subsequently acidified by HNO3 and the other was simultaneously acidified under air condition. Additionally, potential for application as Pb2+ adsorbent and supercapacitor was evaluated. Thermochemical behaviors such as bonding cleavage and dehydration during activation processes were observed by TG and Py-GCMS analysis. Elemental analysis, FT-IR, Raman spectroscopy, and XPS analysis were carried out to confirm changes in structures of each carbon products. New plausible reaction mechanism for this observation was suggested with respect to the formation of a key intermediate in the presence of excess air. As for performance in applications, air activated carbon using hydrochar exhibited high versatility to function as both Pb2+ adsorbent (~41.1 mg/g) and energy storage material (~185.9 F/g) with high specific surface area, mesopore ratio, surface functional groups.
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Affiliation(s)
- Hyewon Hwang
- Department of Forest Sciences, Seoul National University, 599 Gwanak-ro, Gwanak-gu, Seoul, 08826, South Korea
| | - Jae-Hoon Lee
- Department of Forest Sciences, Seoul National University, 599 Gwanak-ro, Gwanak-gu, Seoul, 08826, South Korea
| | - Muhammad Ajaz Ahmed
- Institute of Green-Bio Science andTechnology, Seoul National University, Pyeongchang, Gangwon-do, 25354, South Korea
| | - Joon Weon Choi
- Institute of Green-Bio Science andTechnology, Seoul National University, Pyeongchang, Gangwon-do, 25354, South Korea; Graduate School of International Agricultural Technology, Seoul National University, Pyeongchang, Gangwon-do, 25354, South Korea.
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Jang SH, Sohn SI, Park H, Lee SJ, Kim YW, Hong JM, Kim CH, Choi JW, Kang DH, Kim YS, Hwang YH, Lee JS, Hong JH. The Safety of Intra-arterial Tirofiban during Endovascular Therapy after Intravenous Thrombolysis. AJNR Am J Neuroradiol 2021; 42:1633-1637. [PMID: 34301637 DOI: 10.3174/ajnr.a7203] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Accepted: 04/07/2021] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE The safety and efficacy of tirofiban during endovascular therapy in patients undergoing intravenous thrombolysis with recombinant IV tPA remain unclear. This study aimed to investigate the safety and efficacy of intra-arterial tirofiban use during endovascular therapy in patients treated with IV tPA. MATERIALS AND METHODS Using a multicenter registry, we enrolled patients with acute ischemic stroke who underwent endovascular therapy. Safety outcomes included postprocedural parenchymal hematoma type 2 and/or thick subarachnoid hemorrhage, intraventricular hemorrhage, and 3-month mortality. Efficacy outcomes included the successful reperfusion rate, postprocedural reocclusion, and good outcomes at 3 months (mRS scores of 0-2). The tirofiban effect on the outcomes was evaluated using a multivariable analysis while adjusting for potential confounders. RESULTS Among enrolled patients, we identified 314 patients with stroke (279 and 35 patients in the no tirofiban and tirofiban groups, respectively) due to an intracranial artery occlusion who underwent endovascular therapy with intravenous thrombolysis. A multivariable analysis revealed no association of intra-arterial tirofiban with postprocedural parenchymal hematoma type and/or thick subarachnoid hemorrhage (adjusted OR, 1.07; 95% CI, 0.20-4.10; P = .918), intraventricular hemorrhage (adjusted OR, 0.43; 95% CI, 0.02-2.85; P = .467), and 3-month mortality (adjusted OR, 0.38; 95% CI, 0.04-1.87; P = .299). Intra-arterial tirofiban was not associated with good outcome (adjusted OR, 2.22; 95% CI, 0.89 -6.12; P = .099). CONCLUSIONS Using intra-arterial tirofiban during endovascular therapy after IV tPA could be safe.
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Affiliation(s)
- S H Jang
- From the Departments of Neurology (S.H.J., S.-I.S., H.P., J.-H.H.)
| | - S-I Sohn
- From the Departments of Neurology (S.H.J., S.-I.S., H.P., J.-H.H.)
| | - H Park
- From the Departments of Neurology (S.H.J., S.-I.S., H.P., J.-H.H.)
| | - S-J Lee
- Department of Neurology (S.-J.L., J.M.H., J.S.L.)
| | - Y-W Kim
- Department of Neurology (Y.-W.K., Y.-H.H.)
| | - J M Hong
- Department of Neurology (S.-J.L., J.M.H., J.S.L.)
| | - C-H Kim
- Neurosurgery (C.-H.K.), School of Medicine Keimyung University, Daegu, South Korea
| | - J W Choi
- Radiology (J.W.C.), School of Medicine, Ajou University, Suwon, South Korea
| | | | - Y-S Kim
- Radiology (Y.-S.K.), School of Medicine, Kyungpook National University, Daegu, South Korea
| | - Y-H Hwang
- Department of Neurology (Y.-W.K., Y.-H.H.)
| | - J S Lee
- Department of Neurology (S.-J.L., J.M.H., J.S.L.)
| | - J-H Hong
- From the Departments of Neurology (S.H.J., S.-I.S., H.P., J.-H.H.)
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Lee JH, Kim TM, Choi IG, Choi JW. Phenolic Hydroxyl Groups in the Lignin Polymer Affect the Formation of Lignin Nanoparticles. Nanomaterials (Basel) 2021; 11:nano11071790. [PMID: 34361177 PMCID: PMC8308409 DOI: 10.3390/nano11071790] [Citation(s) in RCA: 9] [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] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 07/06/2021] [Accepted: 07/06/2021] [Indexed: 12/11/2022]
Abstract
Alkaline soda lignin (AL) was sequentially fractionated into six fractions of different molecular size by means of solvent extraction and their phenolic hydroxyl groups were chemoselectively methylated to determine their effect on nanoparticle formation of lignin polymers. The effect of the lignin structure on the physical properties of nanoparticles was also clarified in this study. Nanoparticles were obtained from neat alkaline soda lignin (ALNP), solvent-extracted fractions (FALNPs, i.d. 414–1214 nm), and methylated lignins (MALNPs, i.d. 516–721 nm) via the nanoprecipitation method. Specifically, the size properties of MALNPs showed a high negative correlation (R2 = 0.95) with the phenolic hydroxyl group amount. This indicates that the phenolic hydroxyl groups in lignin could be influenced on the nucleation or condensation during the nanoprecipitation process. Lignin nanoparticles exhibited high colloidal stability, and most of them also showed good in vitro cell viability. This study presents a possible way to control nanoparticle size by blocking specific functional groups and decreasing the interaction between hydroxyl groups of lignin.
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Affiliation(s)
- Jae Hoon Lee
- Department of Agriculture, Forestry and Bioresources, Seoul National University, Seoul 08826, Korea; (J.H.L.); (I.-G.C.)
| | - Tae Min Kim
- Institute of Green-Bio Science and Technology, Seoul National University, Pyeongchang 25354, Korea;
- Graduate School of International Agricultural Technology, Seoul National University, Pyeongchang 25354, Korea
| | - In-Gyu Choi
- Department of Agriculture, Forestry and Bioresources, Seoul National University, Seoul 08826, Korea; (J.H.L.); (I.-G.C.)
- Institute of Green-Bio Science and Technology, Seoul National University, Pyeongchang 25354, Korea;
| | - Joon Weon Choi
- Institute of Green-Bio Science and Technology, Seoul National University, Pyeongchang 25354, Korea;
- Graduate School of International Agricultural Technology, Seoul National University, Pyeongchang 25354, Korea
- Correspondence: ; Tel.: +82-3-3339-5840; Fax: +82-3-3339-5689
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14
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Oh S, Choi IG, Choi JW. Pretreatment of bio-oil with ion exchange resin to improve fuel quality and reduce char during hydrodeoxygenation upgrading with Pt/C. Environ Technol 2021; 42:1132-1144. [PMID: 31429387 DOI: 10.1080/09593330.2019.1658810] [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: 07/18/2018] [Accepted: 08/14/2019] [Indexed: 06/10/2023]
Abstract
To obtain high-quality biofuel, bio-oil obtained from fast pyrolysis of woody biomass was pretreated with ion exchange resin (amberlyst 36) at 50°C, 100°C, and 150°C, and then the recovered liquid product was upgraded using hydrodeoxygenation (HDO) with Pt/C at 300°C. After the two-stage upgrading, 4 types of products (gas, light oil, heavy oil, and char) were obtained. Two-immiscible liquid products were consisted of organic heavy oil, derived from bio-oil, and aqueous light oil, based on the ethanol. The mass balances of the HDO products were influenced by the pretreatment temperature. Ion exchange pretreatment of bio-oil was effective in reducing the char formation during the hydrodeoxygenation (HDO) process. The pretreatment also improved the following heavy oil properties: the water content, heating value, viscosity, acidity, and oxygen level. As a parameter used to indicate the biofuel acidity, the total acid number (TAN) value, was clearly reduced from 114.5 (bio-oil) to 34.1-78.2 (heavy oils). Furthermore, the water and oxygen contents of bio-oil (21.1 and 52.6 wt%, respectively) declined after the pretreatment followed by HDO (ranged 5.1-6.9 and 19.0-25.5 wt%, respectively), thereby improving its higher heating value (HHV) from 17.2 MJ/kg (bio-oil) to 26.2-28.1 MJ/kg (heavy oils). The degree of deoxygenation (DOD) increased as the pretreatment temperature decreased, and the highest energy efficiency (79.8%) was observed after pretreatment at 100°C. In terms of catalyst deactivation during the reaction, both carbon deposition and surface cracking intensified with increasing pretreatment temperatures.
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Affiliation(s)
- Shinyoung Oh
- Department of Forest Sciences, Seoul National University, Seoul, Korea
| | - In-Gyu Choi
- Department of Forest Sciences, Seoul National University, Seoul, Korea
| | - Joon Weon Choi
- Graduate School of International Agricultural Technology and Institute of Green-Bio Science and Technology, Seoul National University, Seoul, Korea
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15
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Kim JC, Kim YC, Choi JW. Use of hydrochlorothiazide and risk of nonmelanoma skin cancer in Koreans: a retrospective cohort study using administrative healthcare data. Clin Exp Dermatol 2021; 46:680-686. [PMID: 33215728 DOI: 10.1111/ced.14520] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 11/11/2020] [Accepted: 11/17/2020] [Indexed: 01/01/2023]
Abstract
BACKGROUND The incidence of skin cancer is increasing because of the ageing population and ultraviolet exposure, and previous studies have revealed that long-term use of hydrochlorothiazide (HCTZ), an antihypertensive agent, has been associated with an increased risk of nonmelanoma skin cancer (NMSC). However, the association of NMSC and HCTZ within East Asian populations is unclear. AIM To investigate the risk of NMSC in Korean subjects using HCTZ. METHODS A retrospective cohort study was conducted using the administrative healthcare data. The study enrolled 62 243 patients exposed to HCTZ with a cumulative dose of ≥ 2500 mg and 62 243 unexposed subjects matched 1 : 1 with the patients for age, sex and income level. RESULTS There was a significant difference in the cumulative incidence of NMSC between the two groups (log-rank P < 0.01). Cox regression analysis was conducted after adjusting for potential confounders, and showed the risk for NMSC in the group exposed to HCTZ was significantly higher than that of the unexposed group (hazard ratio = 1.48; 95% CI 1.03-2.13). In the subgroup analysis, the oldest age group (≥ 70 years) showed increased cumulative incidence of NMSC with statistical significance compared with the unexposed control group (log-rank P < 0.01). CONCLUSIONS In this study, we revealed that the cumulative use of HCTZ (≥ 2500 mg) could increase the risk of NMSC in Koreans, especially the older age group. Thus, HCTZ could be a risk factor for NMSC in East Asian as well as white populations.
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Affiliation(s)
- J C Kim
- Department of Dermatology, Ajou University School of Medicine, Suwon, Korea
| | - Y C Kim
- Department of Dermatology, Ajou University School of Medicine, Suwon, Korea
| | - J W Choi
- Department of Dermatology, Ajou University School of Medicine, Suwon, Korea
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16
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Kwon HY, Yoon HG, Lee C, Chen G, Liu K, Schmid AK, Wu YZ, Choi JW, Won C. Magnetic Hamiltonian parameter estimation using deep learning techniques. Sci Adv 2020; 6:6/39/eabb0872. [PMID: 32978161 PMCID: PMC7518863 DOI: 10.1126/sciadv.abb0872] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 08/10/2020] [Indexed: 05/16/2023]
Abstract
Understanding spin textures in magnetic systems is extremely important to the spintronics and it is vital to extrapolate the magnetic Hamiltonian parameters through the experimentally determined spin. It can provide a better complementary link between theories and experimental results. We demonstrate deep learning can quantify the magnetic Hamiltonian from magnetic domain images. To train the deep neural network, we generated domain configurations with Monte Carlo method. The errors from the estimations was analyzed with statistical methods and confirmed the network was successfully trained to relate the Hamiltonian parameters with magnetic structure characteristics. The network was applied to estimate experimentally observed domain images. The results are consistent with the reported results, which verifies the effectiveness of our methods. On the basis of our study, we anticipate that the deep learning techniques make a bridge to connect the experimental and theoretical approaches not only in magnetism but also throughout any scientific research.
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Affiliation(s)
- H Y Kwon
- Center for Spintronics, Korea Institute of Science and Technology, Seoul 02792, South Korea.
| | - H G Yoon
- Department of Physics, Kyung Hee University, Seoul 02447, South Korea
| | - C Lee
- Department of Physics, Kyung Hee University, Seoul 02447, South Korea
| | - G Chen
- Department of Physics, University of California, Davis, Davis, CA 95616, USA
| | - K Liu
- Department of Physics, University of California, Davis, Davis, CA 95616, USA
- Physics Department, Georgetown University, Washington, DC 20057, USA
| | - A K Schmid
- National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Y Z Wu
- Department of Physics, State Key Laboratory of Surface Physics and Advanced Materials Laboratory, Fudan University, Shanghai 200433, China
| | - J W Choi
- Center for Spintronics, Korea Institute of Science and Technology, Seoul 02792, South Korea
| | - C Won
- Department of Physics, Kyung Hee University, Seoul 02447, South Korea.
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17
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Yang M, Li Q, Chopdekar RV, Dhall R, Turner J, Carlström JD, Ophus C, Klewe C, Shafer P, N'Diaye AT, Choi JW, Chen G, Wu YZ, Hwang C, Wang F, Qiu ZQ. Creation of skyrmions in van der Waals ferromagnet Fe 3GeTe 2 on (Co/Pd) n superlattice. Sci Adv 2020; 6:6/36/eabb5157. [PMID: 32917619 PMCID: PMC7473669 DOI: 10.1126/sciadv.abb5157] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 07/15/2020] [Indexed: 05/27/2023]
Abstract
Magnetic skyrmions are topological spin textures, which usually exist in noncentrosymmetric materials where the crystal inversion symmetry breaking generates the so-called Dzyaloshinskii-Moriya interaction. This requirement unfortunately excludes many important magnetic material classes, including the recently found two-dimensional van der Waals (vdW) magnetic materials, which offer unprecedented opportunities for spintronic technology. Using photoemission electron microscopy and Lorentz transmission electron microscopy, we investigated and stabilized Néel-type magnetic skyrmion in vdW ferromagnetic Fe3GeTe2 on top of (Co/Pd) n in which the Fe3GeTe2 has a centrosymmetric crystal structure. We demonstrate that the magnetic coupling between the Fe3GeTe2 and the (Co/Pd) n could create skyrmions in Fe3GeTe2 without the need of an external magnetic field. Our results open exciting opportunities in spintronic research and the engineering of topologically protected nanoscale features by expanding the group of skyrmion host materials to include these previously unknown vdW magnets.
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Affiliation(s)
- M Yang
- Department of Physics, University of California, Berkeley, CA 94720, USA
| | - Q Li
- Department of Physics, University of California, Berkeley, CA 94720, USA.
| | - R V Chopdekar
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - R Dhall
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - J Turner
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - J D Carlström
- Department of Physics, University of California, Berkeley, CA 94720, USA
| | - C Ophus
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - C Klewe
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - P Shafer
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - A T N'Diaye
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - J W Choi
- Center for Spintronics, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
| | - G Chen
- Department of Physics, University of California, Davis, CA 95616, USA
| | - Y Z Wu
- Department of Physics and State Key Laboratory of Surface Physics, Fudan University, Shanghai 200433, China
| | - C Hwang
- Korea Research Institute of Standards and Science, Yuseong, Daejeon 305-340, Republic of Korea
| | - F Wang
- Department of Physics, University of California, Berkeley, CA 94720, USA
| | - Z Q Qiu
- Department of Physics, University of California, Berkeley, CA 94720, USA.
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18
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Choi JW, Lee ES. Response to 'The incidence and survival of melanoma and nonmelanoma skin cancer in patients with vitiligo: a nationwide population-based matched cohort study in Korea'. Br J Dermatol 2020; 183:1149-1150. [PMID: 32762038 DOI: 10.1111/bjd.19464] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 07/31/2020] [Indexed: 12/12/2022]
Affiliation(s)
- J W Choi
- Department of Dermatology, Ajou University School of Medicine, Suwon, Korea
| | - E-S Lee
- Department of Dermatology, Ajou University School of Medicine, Suwon, Korea
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19
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Park J, Hwang H, Kim JY, Choi JW. Applicability of lignin polymers for automobile brake pads as binder and filler materials and their performance characteristics. Environ Technol 2020; 41:488-497. [PMID: 30028240 DOI: 10.1080/09593330.2018.1503338] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 07/17/2018] [Indexed: 06/08/2023]
Abstract
We present environmentally friendly brake pads produced with three different types of lignin, soda lignin (SL), sulphuric acid lignin (SAL) and heat-treated SAL (HL), as frictional materials to replace phenol formaldehyde resin (PFR, binder) and cashew nut shell liquid (CNSL, filler) in commercial automobile brake pad. Then the performance characteristics of the lignin-added brake pads were tested and compared using several fundamental tests. The results showed that lignin-added brake pads adhered to the SAE standard (0.25) for friction coefficient, which is the primary contributor to the performance of a braking system. In particular, the replacement of PFR with SL demonstrated a better friction coefficient than did replacement with SAL or HL, reaching up to 0.6. On the other hand, when lignin was substituted for CNSL as filler, HL-added brake pads showed a significant improvement in wear resistance of 0.12 g (dust generation) compared to SL and SAL, which had a resistance of approximately 0.25 g.
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Affiliation(s)
- Jeesu Park
- Department of Forest Sciences, Seoul National University, Seoul, Korea
| | - Hyewon Hwang
- Department of Forest Sciences, Seoul National University, Seoul, Korea
| | - Jae Young Kim
- Graduate School of International Agricultural Technology and Institute of Green-Bio Science and Technology, Seoul National University, Pyeongchang, Korea
| | - Joon Weon Choi
- Graduate School of International Agricultural Technology and Institute of Green-Bio Science and Technology, Seoul National University, Pyeongchang, Korea
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20
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Gao N, Je SG, Im MY, Choi JW, Yang M, Li Q, Wang TY, Lee S, Han HS, Lee KS, Chao W, Hwang C, Li J, Qiu ZQ. Creation and annihilation of topological meron pairs in in-plane magnetized films. Nat Commun 2019; 10:5603. [PMID: 31811144 PMCID: PMC6898613 DOI: 10.1038/s41467-019-13642-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 11/18/2019] [Indexed: 11/10/2022] Open
Abstract
Merons which are topologically equivalent to one-half of skyrmions can exist only in pairs or groups in two-dimensional (2D) ferromagnetic (FM) systems. The recent discovery of meron lattice in chiral magnet Co8Zn9Mn3 raises the immediate challenging question that whether a single meron pair, which is the most fundamental topological structure in any 2D meron systems, can be created and stabilized in a continuous FM film? Utilizing winding number conservation, we develop a new method to create and stabilize a single pair of merons in a continuous Py film by local vortex imprinting from a Co disk. By observing the created meron pair directly within a magnetic field, we determine its topological structure unambiguously and explore the topological effect in its creation and annihilation processes. Our work opens a pathway towards developing and controlling topological structures in general magnetic systems without the restriction of perpendicular anisotropy and Dzyaloshinskii–Moriya interaction. A meron is one half of a skyrmion but whether a single meron pair can be created and stabilized remains a challenging question. Here, Gao et al. develop a method to create and stabilize individual pairs of merons in a continuous Py film by local vortex imprinting from Co disks.
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Affiliation(s)
- N Gao
- Key Laboratory of Microelectronic Devices and Integrated Technology, Institute of Microelectronics of Chinese Academy of Sciences, Beijing, 100029, China.,Department of Physics, University of California at Berkeley, Berkeley, CA, 94720, USA
| | - S -G Je
- Center for X-ray Optics, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - M -Y Im
- Center for X-ray Optics, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.,Department of Emerging Materials Science, DGIST, Daegu, Korea
| | - J W Choi
- Center for Spintronics, Korea Institute of Science and Technology, Seoul, 02792, Korea
| | - M Yang
- Department of Physics, University of California at Berkeley, Berkeley, CA, 94720, USA
| | - Q Li
- Department of Physics, University of California at Berkeley, Berkeley, CA, 94720, USA
| | - T Y Wang
- Department of Physics, University of California at Berkeley, Berkeley, CA, 94720, USA
| | - S Lee
- School of Materials Science and Engineering, Ulsan National Institute of Science and Technology, Ulsan, 44919, Korea
| | - H -S Han
- School of Materials Science and Engineering, Ulsan National Institute of Science and Technology, Ulsan, 44919, Korea
| | - K -S Lee
- School of Materials Science and Engineering, Ulsan National Institute of Science and Technology, Ulsan, 44919, Korea
| | - W Chao
- Center for X-ray Optics, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - C Hwang
- Korea Research Institute of Standards and Science, Yuseong, Daejeon, 305-340, Korea
| | - J Li
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China.
| | - Z Q Qiu
- Department of Physics, University of California at Berkeley, Berkeley, CA, 94720, USA.
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21
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Kwon HY, Kim NJ, Lee CK, Yoon HG, Choi JW, Won C. An innovative magnetic state generator using machine learning techniques. Sci Rep 2019; 9:16706. [PMID: 31723230 PMCID: PMC6853879 DOI: 10.1038/s41598-019-53411-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [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: 04/12/2019] [Accepted: 10/28/2019] [Indexed: 12/02/2022] Open
Abstract
We propose a new efficient algorithm to simulate magnetic structures numerically. It contains a generative model using a complex-valued neural network to generate k-space information. The output information is hermitized and transformed into real-space spin configurations through an inverse fast Fourier transform. The Adam version of stochastic gradient descent is used to minimize the magnetic energy, which is the cost of our algorithm. The algorithm provides the proper ground spin configurations with outstanding performance. In model cases, the algorithm was successfully applied to solve the spin configurations of magnetic chiral structures. The results also showed that a magnetic long-range order could be obtained regardless of the total simulation system size.
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Affiliation(s)
- H Y Kwon
- Department of Physics, Kyung Hee University, Seoul, 02447, South Korea
- Center for Spintronics, Korea Institute of Science and Technology, Seoul, 02792, South Korea
| | - N J Kim
- Department of Physics, Kyung Hee University, Seoul, 02447, South Korea
| | - C K Lee
- Department of Physics, Kyung Hee University, Seoul, 02447, South Korea
| | - H G Yoon
- Department of Physics, Kyung Hee University, Seoul, 02447, South Korea
| | - J W Choi
- Center for Spintronics, Korea Institute of Science and Technology, Seoul, 02792, South Korea
| | - C Won
- Department of Physics, Kyung Hee University, Seoul, 02447, South Korea.
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22
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Lee SH, Hosseindoust A, Laxman Ingale S, Rathi PC, Yoon SY, Choi JW, Kim JS. Thermostable xylanase derived from Trichoderma citrinoviride increases growth performance and non-starch polysaccharide degradation in broiler chickens. Br Poult Sci 2019; 61:57-62. [PMID: 31559842 DOI: 10.1080/00071668.2019.1673316] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [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: 12/18/2022]
Abstract
1. The aim of this trial was to determine the optimal supplementation level of a xylanase enzyme from Trichoderma citrinoviride on growth performance, apparent ileal and total tract nutrient retention, intestinal morphology, and intestinal concentration of volatile fatty acids in broiler chickens.2. A total of 600 broiler chickens (Ross 308) of mixed sex were randomly allotted to four treatments, on the basis of similar body weight. The dietary treatments were made from a corn-wheat-soy based diet supplemented with either 0, 3750, 7500, or 11 250 XU/kg xylanase and were fed to 32 d of age.3. A linear response to increasing dietary xylanase was demonstrated for overall weight gain (P < 0.05) and feed conversion ratio (P < 0.05). The apparent total tract digestibility of dry matter and gross energy, and the coefficient of apparent ileal digestibility (CIAD) of N and soluble non-starch polysaccharides were linearly improved when xylanase was added to the diet (P < 0.05). Moreover, a linear increase (P < 0.05) was observed in the CIAD of Arg, Lys, and Try with increasing dietary levels of xylanase.4. The viscosity of digesta in ileum was linearly decreased when dietary xylanase level increased (P < 0.05).5. An increase in villus height of the duodenum and jejunum were observed with increasing dietary levels of xylanase (linear, P < 0.05).6. Overall, the results showed that the effects of dietary xylanase supplementation on broiler performance was determined through effects on nutrient availability and intestinal morphology.
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Affiliation(s)
- S H Lee
- Department of Swine Science, Korea National College of Agriculture and Fisheries, Jeonju, Republic of Korea
| | - A Hosseindoust
- Department of Animal Life Science, Kangwon National University, Chuncheon, Republic of Korea
| | | | - P C Rathi
- Advanced Enzyme Technologies Ltd., Thane, India
| | - S Y Yoon
- Department of Animal Life Science, Kangwon National University, Chuncheon, Republic of Korea
| | - J W Choi
- Department of Animal Life Science, Kangwon National University, Chuncheon, Republic of Korea
| | - J S Kim
- Department of Animal Life Science, Kangwon National University, Chuncheon, Republic of Korea
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23
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Park SY, Kim JY, Youn HJ, Choi JW. Utilization of lignin fractions in UV resistant lignin-PLA biocomposites via lignin-lactide grafting. Int J Biol Macromol 2019; 138:1029-1034. [DOI: 10.1016/j.ijbiomac.2019.07.157] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 07/18/2019] [Accepted: 07/24/2019] [Indexed: 11/25/2022]
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Kim DY, Jung WS, Choi JW, Choung J, Kim HG. Evaluating Tissue Contrast and Detecting White Matter Injury in the Infant Brain: A Comparison Study of Synthetic Phase-Sensitive Inversion Recovery. AJNR Am J Neuroradiol 2019; 40:1406-1412. [PMID: 31345940 DOI: 10.3174/ajnr.a6135] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2019] [Accepted: 06/17/2019] [Indexed: 12/17/2022]
Abstract
BACKGROUND AND PURPOSE Synthetic MR imaging enables the acquisition of phase-sensitive inversion recovery images. The aim of this study was to compare the image quality of synthetic phase-sensitive inversion recovery with that of other sequences in infants. MATERIALS AND METHODS Brain MR imaging with 3D T1-weighted fast-spoiled gradient recalled, synthetic T1WI, and synthetic phase-sensitive inversion recovery of 91 infants was compared. Contrast between unmyelinated WM and myelinated WM and between unmyelinated WM and cortical GM was calculated. Qualitative evaluation of image quality and myelination degree was performed. In infants with punctate white matter injuries, the number of lesions was compared. RESULTS The contrast between unmyelinated WM and myelinated WM was higher in synthetic phase-sensitive inversion recovery compared with fast-spoiled gradient recalled or synthetic T1WI (P < .001). Compared with synthetic T1WI, synthetic phase-sensitive inversion recovery showed higher gray-white matter differentiation (P < .001) and myelination degree in the cerebellar peduncle (P < .001). The number of detected punctate white matter injuries decreased with synthetic phase-sensitive inversion recovery compared with fast-spoiled gradient recalled sequences (1.2 ± 3.2 versus 3.4 ± 3.6, P = .001). CONCLUSIONS Synthetic phase-sensitive inversion recovery has the potential to improve tissue contrast and image quality in the brain MR imaging of infants. However, we have to be aware that synthetic phase-sensitive inversion recovery has limited value when assessing punctate white matter injuries compared with 3D fast-spoiled gradient recalled imaging.
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Affiliation(s)
- D Y Kim
- From the Department of Radiology (D.Y.K., W.S.J., J.W.C., H.G.K.)
| | - W S Jung
- From the Department of Radiology (D.Y.K., W.S.J., J.W.C., H.G.K.)
| | - J W Choi
- From the Department of Radiology (D.Y.K., W.S.J., J.W.C., H.G.K.)
| | - J Choung
- Biomedical Informatics (J.C.), Ajou University School of Medicine, Suwon, Republic of Korea.,Office of Biostatistics (J.C.), Ajou Research Institute for Innovative Medicine, Ajou University Medical Center, Suwon, Republic of Korea
| | - H G Kim
- From the Department of Radiology (D.Y.K., W.S.J., J.W.C., H.G.K.) .,Department of Radiology (H.G.K.), Eunpyeong St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
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Park HS, Choi JW. Combined surgical approach to intralabyrinthine schwannoma. Eur Ann Otorhinolaryngol Head Neck Dis 2019; 137:223-226. [PMID: 31208878 DOI: 10.1016/j.anorl.2018.09.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [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: 06/03/2018] [Revised: 09/11/2018] [Accepted: 09/27/2018] [Indexed: 11/19/2022]
Abstract
INTRODUCTION Intralabyrinthine schwannoma (ILS) is a tumor originating from the Schwann cells in the inner ear. Various surgical approaches can be used for the resection of ILS. The aim of this report is to describe a case involving a 60-year-old man who was treated successfully with a combined surgical approach. CASE REPORT The patient underwent a combined microscopic (transmastoid labyrinthectomy) and endoscopic procedure for surgical excision of ILS involving the vestibule and the lower half of the cochlear basal turn. The combined surgical technique enabled a complete removal of the ILS without removal of the unaffected cochlea as well as the external auditory canal. Besides additional exclusion of the middle ear, blind-sac closure of the external auditory canal and cavity obliteration were avoided. No postoperative complications were observed. DISCUSSION A combined microscopic and endoscopic approach to surgery enables removal of the ILS involving the vestibule and the lower half of the cochlear basal turn while helping to reduce surgical radicality.
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Affiliation(s)
- H-S Park
- Department of Otorhinolaryngology-Head and Neck Surgery, College of Medicine, Chungnam National University, 282 Munhwa-ro, Jung-gu, Daejeon 35015, South Korea
| | - J W Choi
- Department of Otorhinolaryngology-Head and Neck Surgery, College of Medicine, Chungnam National University, 282 Munhwa-ro, Jung-gu, Daejeon 35015, South Korea.
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Roh HG, Kim EY, Kim IS, Lee HJ, Park JJ, Lee SB, Choi JW, Jeon YS, Park M, Kim SU, Kim HJ. A Novel Collateral Imaging Method Derived from Time-Resolved Dynamic Contrast-Enhanced MR Angiography in Acute Ischemic Stroke: A Pilot Study. AJNR Am J Neuroradiol 2019; 40:946-953. [PMID: 31097431 DOI: 10.3174/ajnr.a6068] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 04/12/2019] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Assessment of the collateral status has been emphasized for appropriate treatment decisions in patients with acute ischemic stroke. The purpose of this study was to introduce a multiphase MRA collateral imaging method (collateral map) derived from time-resolved dynamic contrast-enhanced MRA and to verify the value of the multiphase MRA collateral map in acute ischemic stroke by comparing it with the multiphase collateral imaging method (MRP collateral map) derived from dynamic susceptibility contrast-enhanced MR perfusion. MATERIALS AND METHODS From a prospectively maintained registry of acute ischemic stroke, MR imaging data of patients with acute ischemic stroke caused by steno-occlusive lesions of the unilateral ICA and/or the M1 segment of the MCA were analyzed. We generated collateral maps using dynamic signals from dynamic contrast-enhanced MRA and DSC-MRP using a Matlab-based in-house program and graded the collateral scores of the multiphase MRA collateral map and the MRP collateral map independently. Interobserver reliabilities and intermethod agreement between both collateral maps for collateral grading were tested. RESULTS Seventy-one paired multiphase MRA and MRP collateral maps from 67 patients were analyzed. The interobserver reliabilities for collateral grading using multiphase MRA or MRP collateral maps were excellent (weighted κ = 0.964 and 0.956, respectively). The agreement between both collateral maps was also excellent (weighted κ = 0.884; 95% confidence interval, 0.819-0.949). CONCLUSIONS We demonstrated that the dynamic signals of dynamic contrast-enhanced MRA could be used to generate multiphase collateral images and showed the possibility of the multiphase MRA collateral map as a useful collateral imaging method in acute ischemic stroke.
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Affiliation(s)
- H G Roh
- From the Departments of Radiology (H.G.R., J.W.C.)
| | - E Y Kim
- Department of Radiology (E.Y.K.), Gachon University Gil Medical Center, Incheon, Korea
| | - I S Kim
- Siemens Healthineers Ltd (I.S.K.), Seoul, Korea
| | - H J Lee
- Departments of Neurosurgery (H.J.L., S.U.K.)
| | | | | | - J W Choi
- From the Departments of Radiology (H.G.R., J.W.C.)
| | - Y S Jeon
- Neurosurgery (Y.S.J.), Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Korea
| | - M Park
- Department of Radiology (M.P.), Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - S U Kim
- Departments of Neurosurgery (H.J.L., S.U.K.)
| | - H J Kim
- Radiology (H.J.K.), Daejeon St. Mary's Hospital, The Catholic University of Korea, Daejeon, Korea
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Hwang H, Lee JH, Choi IG, Choi JW. Comprehensive characterization of hydrothermal liquefaction products obtained from woody biomass under various alkali catalyst concentrations. Environ Technol 2019; 40:1657-1667. [PMID: 29333927 DOI: 10.1080/09593330.2018.1427799] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [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: 08/11/2017] [Accepted: 01/10/2018] [Indexed: 06/07/2023]
Abstract
Hydrothermal liquefaction (HTL) of lignocellulosic biomass has been widely investigated for the production of renewable and alternative bio-crude oil. In this study, catalytic hydrothermal processing of two biomasses (larch and Mongolian oak) was performed using different K2CO3 concentrations (0, 0.1, 0.5, 1.0 wt% of solvent) to improve fuel yield and properties. HTL oil, hydrochar, water-soluble fraction (WSF) and gas were characterized, and carbon balance was investigated. As a result, the maximum yield of HTL oil, 27.7 wt% (Mongolian oak) and 25.7 wt% (larch), and the highest carbon conversion ratio was obtained with 0.5 wt% of catalyst. The high catalyst concentration also resulted in an increase in higher heating values up to 31.9 MJ/kg. In addition, the amount of organic compounds in HTL oil also increased, specifically for lignin-derived compounds including catechol and hydroquinone which can be derived from secondary hydrolysis of lignin. On the other hand, formation of hydrochar was suppressed with the addition of alkali catalyst and the yield dramatically decreased from 30.7-40.8 wt.% to 20.0-21.8 wt.%. Furthermore, it was revealed that WSF had low organic carbon content less than 3.4% and high potassium content mostly derived from alkali catalyst, indicating that it may be reusable with simple purification. This work suggests that the addition of the proper amount of alkali catalyst can improve the production efficiency and quality of bio-crude oil, and another potential of WSF to be recyclable in further work.
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Affiliation(s)
- Hyewon Hwang
- a Department of Forest Sciences , Seoul National University , Seoul , Korea
| | - Jae Hoon Lee
- a Department of Forest Sciences , Seoul National University , Seoul , Korea
| | - In-Gyu Choi
- a Department of Forest Sciences , Seoul National University , Seoul , Korea
| | - Joon Weon Choi
- b Graduate School of International Agricultural Technology and Institute of Green-Bio Science and Technology , Seoul National University , Pyeongchang , Korea
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Lee SC, Tran TMT, Choi JW, Won K. Lignin for white natural sunscreens. Int J Biol Macromol 2019; 122:549-554. [DOI: 10.1016/j.ijbiomac.2018.10.184] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Revised: 10/23/2018] [Accepted: 10/25/2018] [Indexed: 12/14/2022]
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Kim YS, Kim Y, Choi JW, Oh HE, Lee JH. Genetic variants and risk of prostate cancer using pathway analysis of a genome-wide association study. Neoplasma 2019; 63:629-34. [PMID: 27268928 DOI: 10.4149/neo_2016_418] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
This study explored candidate causal single nucleotide polymorphisms (SNPs) to clarify the biological mechanism of prostate cancer (PCa). Identify candidate Causal SNPs and Pathways (ICSNPathway) analysis was applied using a PCa genome-wide association study (GWAS) dataset that included 473,736 SNPs in 1151 cases of PCa and 1156 controls of European ancestry. Five candidate causal SNPs, three candidate causal genes, and two candidate causal pathways were identified using integrating linkage disequilibrium analysis, functional SNP annotation, and pathway-based analysis. The ICSNPathway analysis suggested three hypothetical mechanisms of PCa. The first was rs13112390, rs13112358, rs2048074 to nei-like DNA glycosylase 3 (NEIL3) gene to damaged DNA binding. The second was rs3087386 to REV1, DNA directed polymerase (REV1) gene to damaged DNA binding. The third was rs1063134 to potassium channel, inwardly rectifying subfamily J, member 4 (KCNJ4) gene to inward rectifier potassium channel activity.
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Kim HG, Lee JH, Choi JW, Han M, Gho SM, Moon Y. Multidelay Arterial Spin-Labeling MRI in Neonates and Infants: Cerebral Perfusion Changes during Brain Maturation. AJNR Am J Neuroradiol 2018; 39:1912-1918. [PMID: 30213808 DOI: 10.3174/ajnr.a5774] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 07/08/2018] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Arterial spin-labeling with multiple postlabeling delays can correct transit times. We tried to evaluate CBF in neonates and infants using multidelay arterial spin-labeling. MATERIALS AND METHODS Multidelay arterial spin-labeling was applied to 13 preterm neonates (mean postmenstrual age, 34.9 weeks), 13 term-equivalent-age neonates (mean postmenstrual age, 39.2 weeks), and 6 infants (mean postmenstrual age, 57.8 weeks). Transit time-corrected CBF in the caudate, thalamus, frontal GM, occipital GM, frontal WM, and occipital WM was measured, and relative CBF compared with the whole-brain CBF was calculated. Inter- and intragroup comparisons were performed among the 3 age groups. A correlation and nonlinear regression analysis were performed between postmenstrual age and CBF. RESULTS Intergroup comparisons showed significantly higher whole-brain CBF in infants (38.3 mL/100 g/min) compared with preterm (15.5 mL/100 g/min) and term-equivalent-age (18.3 mL/100 g/min) neonates (P < .001). In the intragroup comparison, all 3 groups showed significantly higher relative CBF values in the occipital WM (63.6%-90.3%) compared with the frontal WM (46.3%-73.9%). In term-equivalent-age neonates, the occipital GM (120.8%) had significantly higher relative CBF values than the frontal GM (103.5%). There was a significant negative correlation between postmenstrual age and the relative CBF of the thalamus (r = - 0.449, P = .010). There were significant positive relationships between postmenstrual age and the relative CBF of the frontal WM (R 2 = 0.298, P = .001) and occipital WM (R 2 = 0.452, P < .001). CONCLUSIONS Multidelay arterial spin-labeling with transit time-corrected CBF showed developmental changes and regional differences of CBF in neonates and infants.
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Affiliation(s)
- H G Kim
- From the Departments of Radiology (H.G.K., J.W.C., M.H.)
| | | | - J W Choi
- From the Departments of Radiology (H.G.K., J.W.C., M.H.)
| | - M Han
- From the Departments of Radiology (H.G.K., J.W.C., M.H.)
| | - S-M Gho
- MR Clinical Research and Development (S.-M.G.), GE Healthcare Korea, Seoul, Korea
| | - Y Moon
- Office of Biostatistics (Y.M.), Institute of Medical Sciences, Ajou University School of Medicine, Ajou University Medical Center, Suwon, Korea
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Lim YH, Choi YW, Park JY, Lee YG, Choi JW, Park HK, Cho SH, Cho SH. P4423Non-contact heart beat monitoring using impulse-radio ultra-wide band radar technology. Eur Heart J 2018. [DOI: 10.1093/eurheartj/ehy563.p4423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Y.-H Lim
- Hanyang University, Seoul, Korea Republic of
| | - Y W Choi
- Hanyang University, Seoul, Korea Republic of
| | - J Y Park
- Hanyang University, Seoul, Korea Republic of
| | - Y G Lee
- Hanyang University, Seoul, Korea Republic of
| | - J W Choi
- Hanyang University, Seoul, Korea Republic of
| | - H K Park
- Hanyang University, Seoul, Korea Republic of
| | - S.-H Cho
- Hanyang University, Seoul, Korea Republic of
| | - S H Cho
- Hanyang University, Seoul, Korea Republic of
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32
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Huiting LN, Samaha Y, Zhang GL, Roderick JE, Li B, Anderson NM, Wang YW, Wang L, Laroche F, Choi JW, Liu CT, Kelliher MA, Feng H. UFD1 contributes to MYC-mediated leukemia aggressiveness through suppression of the proapoptotic unfolded protein response. Leukemia 2018; 32:2339-2351. [PMID: 29743725 PMCID: PMC6202254 DOI: 10.1038/s41375-018-0141-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 03/11/2018] [Accepted: 03/15/2018] [Indexed: 02/07/2023]
Abstract
Despite the pivotal role of MYC in tumorigenesis, the mechanisms by which it promotes cancer aggressiveness remain incompletely understood. Here we show that MYC transcriptionally upregulates the ubiquitin fusion degradation 1 (UFD1) gene in T-cell acute lymphoblastic leukemia (T-ALL). Allelic loss of ufd1 in zebrafish induces tumor-cell apoptosis and impairs MYC-driven T-ALL progression but does not affect general health. As the E2 component of an endoplasmic reticulum (ER)-associated degradation (ERAD) complex, UFD1 facilitates the elimination of misfolded/unfolded proteins from the ER. We found that UFD1 inactivation in human T-ALL cells impairs ERAD, exacerbates ER stress, and induces apoptosis. Moreover, we show that UFD1 inactivation promotes the proapoptotic unfolded protein response (UPR) mediated by protein kinase RNA-like ER kinase (PERK). This effect is demonstrated by an upregulation of PERK and its downstream effector C/EBP homologous protein (CHOP), as well as a downregulation of BCL2 and BCLxL. Indeed, CHOP inactivation or BCL2 overexpression is sufficient to rescue tumor-cell apoptosis induced by UFD1 knockdown. Together, our studies identify UFD1 as a critical regulator of the ER stress response and a novel contributor to MYC-mediated leukemia aggressiveness, with implications for targeted therapy in T-ALL and likely other MYC-driven cancers.
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Affiliation(s)
- L N Huiting
- Departments of Pharmacology and Medicine, Cancer Research Center, Section of Hematology and Medical Oncology, Boston University School of Medicine, Boston, MA, USA
| | - Y Samaha
- Departments of Pharmacology and Medicine, Cancer Research Center, Section of Hematology and Medical Oncology, Boston University School of Medicine, Boston, MA, USA
| | - G L Zhang
- Department of Computer Science, Metropolitan College, Boston University, Boston, MA, USA.,Cancer Vaccine Center, Dana-Farber Cancer Institute, Boston, MA, USA
| | - J E Roderick
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts School of Medicine, Worcester, MA, USA
| | - B Li
- Departments of Pharmacology and Medicine, Cancer Research Center, Section of Hematology and Medical Oncology, Boston University School of Medicine, Boston, MA, USA
| | - N M Anderson
- Departments of Pharmacology and Medicine, Cancer Research Center, Section of Hematology and Medical Oncology, Boston University School of Medicine, Boston, MA, USA
| | - Y W Wang
- Departments of Pharmacology and Medicine, Cancer Research Center, Section of Hematology and Medical Oncology, Boston University School of Medicine, Boston, MA, USA.,Department of Anatomy and Embryology, Wuhan University School of Basic Medical Sciences, Wuhan, Hubei, P. R. China
| | - L Wang
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
| | - Fjf Laroche
- Departments of Pharmacology and Medicine, Cancer Research Center, Section of Hematology and Medical Oncology, Boston University School of Medicine, Boston, MA, USA
| | - J W Choi
- Departments of Pharmacology and Medicine, Cancer Research Center, Section of Hematology and Medical Oncology, Boston University School of Medicine, Boston, MA, USA
| | - C T Liu
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
| | - M A Kelliher
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts School of Medicine, Worcester, MA, USA
| | - H Feng
- Departments of Pharmacology and Medicine, Cancer Research Center, Section of Hematology and Medical Oncology, Boston University School of Medicine, Boston, MA, USA.
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Kang SP, Kim NJ, Kwon HY, Choi JW, Min BC, Won C. The spin structures of interlayer coupled magnetic films with opposite chirality. Sci Rep 2018; 8:2361. [PMID: 29402938 PMCID: PMC5799310 DOI: 10.1038/s41598-018-20800-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 01/22/2018] [Indexed: 11/21/2022] Open
Abstract
Using Monte-Carlo simulations and micromagnetic simulations, we reveal how the spin structural correlation and the skyrmion dynamics are affected by the interlayer coupling in a chiral magnetic bilayer system, in which the two layers have opposite chirality. The interaction through interlayer coupling between chiral magnetic structures influences the static and dynamics properties profoundly. The competition between the Dzyaloshinskii-Moriya interaction and the interlayer interaction allows multiple magnetic structures to be energetically stable, which includes sole skyrmion states (skyrmion appears in only one of the layers) and skyrmion pair states (coupled skyrmions in top and bottom layers). When current driven spin transfer torques are applied to each state, the sole skyrmion state is mainly propelled by a spin transfer torque causing the skyrmion hall effect, but the skyrmion pair state is propelled by a torque from skyrmion-skyrmion interaction and not influenced by the skyrmion hall effect. Also upon application of an external magnetic field, we found the skyrmions in a skyrmion pair state extinguish in an exclusive way, as the annihilation of a skyrmion in one of the layers stabilizes the once paired skyrmion in the other layer, i.e. the skyrmion lattice sites have only one skyrmion in either layer.
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Affiliation(s)
- S P Kang
- Department of Physics, Kyung Hee University, Seoul, 02447, Korea
| | - N J Kim
- Department of Physics, Kyung Hee University, Seoul, 02447, Korea
| | - H Y Kwon
- Department of Physics, Kyung Hee University, Seoul, 02447, Korea
| | - J W Choi
- Center for Spintronics Research, Korea Institute of Science and Technology, Seoul, 02792, Korea
| | - B C Min
- Center for Spintronics Research, Korea Institute of Science and Technology, Seoul, 02792, Korea
| | - C Won
- Department of Physics, Kyung Hee University, Seoul, 02447, Korea.
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Kim YK, Choi JW, Kim HJ, Kim HY, Park GM, Ko YH, Cha J, Kim ST. Melanoma of the Sinonasal Tract: Value of a Septate Pattern on Precontrast T1-Weighted MR Imaging. AJNR Am J Neuroradiol 2018; 39:762-767. [PMID: 29371259 DOI: 10.3174/ajnr.a5539] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 11/20/2017] [Indexed: 12/22/2022]
Abstract
BACKGROUND AND PURPOSE Various tumors of the sinonasal tract can exhibit high signal intensity on T1WI. The purpose of this study was to determine the value of a septate pattern on precontrast T1WI for diagnosing sinonasal melanoma. MATERIALS AND METHODS Retrospectively, 3 observers independently reviewed MR images of 31 histologically proved sinonasal melanomas with special attention to the presence or absence of a septate pattern on precontrast T1WI, defined as alternating hyperintense and hypointense striations on precontrast T1WI. For comparison, we evaluated the prevalence of a septate pattern on precontrast T1WI in 106 nonmelanomatous sinonasal malignant tumors with 16 different histologic types. We also tried to identify the histopathologic features responsible for the septate pattern on precontrast T1WI. RESULTS Twenty-seven (87.1%) of 31 sinonasal melanomas showed hyperintense foci on T1WI, among which a septate pattern on precontrast T1WI was seen in 23 (74.2%), while 22 (20.8%) of 106 nonmelanomatous malignant tumors demonstrated hyperintense foci on T1WI, among which only 3 (2.8%) showed a septate pattern on precontrast T1WI. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of a septate pattern on precontrast T1WI for the diagnosis of sinonasal melanoma were 74%, 97%, 88%, 93%, and 92%, respectively. Although limited due to the retrospective nature, 4 of 23 histologically reviewed sinonasal melanomas revealed an uneven distribution of melanin with alternating melanin and fibrous bands within the tumors. CONCLUSIONS A septate pattern on precontrast T1WI might be an adjunctive imaging finding for the diagnosis of sinonasal melanoma. This might be attributed histologically to an uneven distribution of melanin and hemorrhage within the tumors.
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Affiliation(s)
- Y-K Kim
- From the Departments of Radiology (Y.-K.K., H.-J.K., H.Y.K., G.M.P., J.C., S.T.K.)
| | - J W Choi
- Department of Radiology (J.W.C.), Ajou University School of Medicine, Suwon, Korea
| | - H-J Kim
- From the Departments of Radiology (Y.-K.K., H.-J.K., H.Y.K., G.M.P., J.C., S.T.K.)
| | - H Y Kim
- From the Departments of Radiology (Y.-K.K., H.-J.K., H.Y.K., G.M.P., J.C., S.T.K.)
| | - G M Park
- From the Departments of Radiology (Y.-K.K., H.-J.K., H.Y.K., G.M.P., J.C., S.T.K.).,Department of Radiology (G.M.P.), Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Korea
| | - Y-H Ko
- Pathology (Y.-H.K.), Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - J Cha
- From the Departments of Radiology (Y.-K.K., H.-J.K., H.Y.K., G.M.P., J.C., S.T.K.).,Department of Radiology and Research Institute of Radiological Science (J.C.), College of Medicine, Yonsei University College of Medicine, Seoul, Korea
| | - S T Kim
- From the Departments of Radiology (Y.-K.K., H.-J.K., H.Y.K., G.M.P., J.C., S.T.K.)
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Park SY, Kim JY, Youn HJ, Choi JW. Fractionation of lignin macromolecules by sequential organic solvents systems and their characterization for further valuable applications. Int J Biol Macromol 2018; 106:793-802. [DOI: 10.1016/j.ijbiomac.2017.08.069] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 08/07/2017] [Accepted: 08/10/2017] [Indexed: 10/19/2022]
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Lim JM, Choi JH, Choi JW, Yun JW, Park TJ, Park JP. Cloning, Expression, and Production of Xylo-Oligosaccharides by Using a Newly Screened Xylanase Isolated from Bovine Rumen. Appl Biochem Biotechnol 2017; 184:1347-1357. [PMID: 29027104 DOI: 10.1007/s12010-017-2623-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 10/02/2017] [Indexed: 10/18/2022]
Affiliation(s)
- J M Lim
- Department of Pharmaceutical Engineering, Daegu Haany University, 290 Yugok-dong, Gyeongsan, 38610, Republic of Korea
| | - J H Choi
- Microbial Biotechnology Research Center, Jeonbuk Branch Institute, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 181 Ipsin-gil, Jeongeup-si, 28116, Republic of Korea
| | - J W Choi
- Department of Bioindustry, Daegu University, Gyeongsan, 38453, Republic of Korea
| | - J W Yun
- Department of Biotechnology, Daegu University, Gyeongsan, 38453, Republic of Korea
| | - T J Park
- Department of Chemistry, Institute of Interdisciplinary Convergence Research, Research Institute of Halal Industrialization Technology, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul, 06974, Republic of Korea
| | - J P Park
- Department of Pharmaceutical Engineering, Daegu Haany University, 290 Yugok-dong, Gyeongsan, 38610, Republic of Korea.
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Jeong WS, Choi JW, Kim DY, Lee JY, Kwon SM. Corrigendum to "Can a surgery-first orthognathic approach reduce the total treatment time?" [Int. J. Oral Maxillofac. Surg. 46 (2017) 473-482]. Int J Oral Maxillofac Surg 2017. [PMID: 28623044 DOI: 10.1016/j.ijom.2017.05.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- W S Jeong
- Department of Plastic and Reconstructive Surgery, University of Ulsan, College of Medicine, Seoul Asan Medical Center, Seoul, Republic of Korea
| | - J W Choi
- Department of Plastic and Reconstructive Surgery, University of Ulsan, College of Medicine, Seoul Asan Medical Center, Seoul, Republic of Korea.
| | - D Y Kim
- Department of Plastic and Reconstructive Surgery, University of Ulsan, College of Medicine, Seoul Asan Medical Center, Seoul, Republic of Korea
| | - J Y Lee
- Smile Again Orthodontic Center, Seoul, Republic of Korea
| | - S M Kwon
- Eastman Dental Clinic, Seoul, Republic of Korea
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Bak SH, Roh HG, Moon WJ, Choi JW, An HS. Appropriate Minimal Dose of Gadobutrol for 3D Time-Resolved MRA of the Supra-Aortic Arteries: Comparison with Conventional Single-Phase High-Resolution 3D Contrast-Enhanced MRA. AJNR Am J Neuroradiol 2017; 38:1383-1390. [PMID: 28473338 DOI: 10.3174/ajnr.a5176] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 02/13/2017] [Indexed: 01/25/2023]
Abstract
BACKGROUND AND PURPOSE The development of nephrogenic systemic fibrosis and neural tissue deposition is gadolinium dose-dependent. The purpose of this study was to determine the appropriate minimal dose of gadobutrol with time-resolved MRA to assess supra-aortic arterial stenosis with contrast-enhanced MRA as a reference standard. MATERIALS AND METHODS Four hundred sixty-two consecutive patients underwent both standard-dose contrast-enhanced MRA and low-dose time-resolved MRA and were classified into 3 groups; group A (a constant dose of 1 mL for time-resolved MRA), group B (2 mL), or group C (3 mL). All studies were independently evaluated by 2 radiologists for image quality by using a 5-point scale (from 0 = failure to 4 = excellent), grading of arterial stenosis (0 = normal, 1 = mild [<30%], 2 = moderate [30%-69%], 3 = severe to occlusion [≥70%]), and signal-to-noise ratio. RESULTS The image quality of time-resolved MRA was similar to that of contrast-enhanced MRA in groups B and C, but it was inferior to contrast-enhanced MRA in group A. For the grading of arterial stenosis, there was an excellent correlation between contrast-enhanced MRA and time-resolved MRA (R = 0.957 for group A, R = 0.988 for group B, R = 0.991 for group C). The SNR of time-resolved MRA tended to be lower than that of contrast-enhanced MRA in groups A and B. However, SNR was higher for time-resolved MRA compared with contrast-enhanced MRA in group C. CONCLUSIONS Low-dose time-resolved MRA is feasible in the evaluation of supra-aortic stenosis and could be used as an alternative to contrast-enhanced MRA for a diagnostic technique in high-risk populations.
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Affiliation(s)
- S H Bak
- From the Department of Radiology (S.H.B., H.G.R., W.-J.M., J.W.C.), Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Korea.,Department of Radiology (S.H.B.), Kangwon National University Hospital, Chuncheon, Korea
| | - H G Roh
- From the Department of Radiology (S.H.B., H.G.R., W.-J.M., J.W.C.), Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Korea
| | - W-J Moon
- From the Department of Radiology (S.H.B., H.G.R., W.-J.M., J.W.C.), Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Korea
| | - J W Choi
- From the Department of Radiology (S.H.B., H.G.R., W.-J.M., J.W.C.), Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Korea
| | - H S An
- Department of Radiology (H.S.A.), Armed Forces Yangju Hospital, Yangju, Korea
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Seo K, Choi JW, Kim DW, Han D, Noh SJ, Jung HS. Aminophylline Effect on Renal Ischemia-Reperfusion Injury in Mice. Transplant Proc 2017; 49:358-365. [PMID: 28219599 DOI: 10.1016/j.transproceed.2016.11.043] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 10/01/2016] [Accepted: 11/16/2016] [Indexed: 01/25/2023]
Abstract
BACKGROUND Aminophylline increases the intracellular concentration of cAMP and exerts an anti-inflammatory effect. The aim of this study was to investigate the effect of aminophylline on renal ischemia-reperfusion (I/R) injury in mice. METHODS Thirty C57BL/6 mice were divided into 3 groups. In the sham group (group S, n = 10), only right nephrectomy was performed. In the control group (group C, n = 10), after right nephrectomy, the mice were subjected to 30 minutes of left renal ischemia. In the aminophylline group (group A, n = 10), an intraperitoneal injection of aminophylline (5 mg/kg) was performed before renal ischemia. Twenty-four hours after reperfusion, the mice were euthanized, and plasma and kidney samples were obtained to analyze the serum creatinine, renal histology, and expression levels of nuclear factor-kappa B (NF-kB) and pro-inflammatory cytokines. RESULTS The serum creatinine concentration in group C was markedly elevated at 24 hours after reperfusion. Aminophylline treatment significantly reduced serum creatinine, compared with group C. Aminophylline also reduced the histological evidence of renal damage. The expression levels of NF-kB, tumor necrosis factor-α (TNF-α), monocyte chemoattractant protein-1 (MCP-1), macrophage inflammatory protein-2 (MIP-2), and intercellular adhesion molecule-1 (ICAM-1) mRNA were significantly increased in group C (P < .001). Group A showed lower expression of NF-kB, TNF-α, MCP-1, MIP-2, and ICAM-1 mRNA than group C (P < .01). CONCLUSIONS Aminophylline treatment improved the renal function and indexes of renal inflammation, which suggests that it provided reno-protection against renal I/R injury.
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Affiliation(s)
- K Seo
- Department of Anesthesiology and Pain Medicine, St Vincent's Hospital, The Catholic University of Korea, Seoul, Korea
| | - J W Choi
- Department of Anesthesiology and Pain Medicine, St Vincent's Hospital, The Catholic University of Korea, Seoul, Korea
| | - D-W Kim
- Department of Anesthesiology and Pain Medicine, St Vincent's Hospital, The Catholic University of Korea, Seoul, Korea
| | - D Han
- Department of Anesthesiology and Pain Medicine, St Vincent's Hospital, The Catholic University of Korea, Seoul, Korea
| | - S J Noh
- The Research Institute of Medical Science, St Vincent's Hospital, The Catholic University of Korea, Seoul, Korea
| | - H S Jung
- Department of Anesthesiology and Pain Medicine, St Vincent's Hospital, The Catholic University of Korea, Seoul, Korea.
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Kim UJ, Lee YR, Kang TH, Choi JW, Kimura S, Wada M. Protein adsorption of dialdehyde cellulose-crosslinked chitosan with high amino group contents. Carbohydr Polym 2017; 163:34-42. [DOI: 10.1016/j.carbpol.2017.01.052] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2016] [Revised: 01/09/2017] [Accepted: 01/14/2017] [Indexed: 10/20/2022]
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Choi JW, Lee D, Hyun SH, Han M, Kim JH, Lee SJ. Intratumoural heterogeneity measured using FDG PET and MRI is associated with tumour-stroma ratio and clinical outcome in head and neck squamous cell carcinoma. Clin Radiol 2017; 72:482-489. [PMID: 28285707 DOI: 10.1016/j.crad.2017.01.019] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 01/02/2017] [Accepted: 01/31/2017] [Indexed: 11/28/2022]
Abstract
AIM To evaluate the association between the tumour-stroma ratio and intratumoural heterogeneity measured using 2-[18F]-fluoro-2-deoxy-d-glucose (FDG) positron-emission tomography (PET) and magnetic resonance imaging (MRI), and further investigate the prognostic significance of imaging biomarkers in head and neck squamous cell carcinoma (HNSCC). MATERIALS AND METHODS Textural-based imaging parameters of the primary tumour were extracted in 44 patients. In addition, the difference between the minimum and maximum apparent diffusion coefficient (ADC) values (ADCdiff) was calculated on MRI. The relationships between the tumour-stroma ratio and imaging parameters were evaluated. The associations between imaging parameters and recurrence-free survival (RFS) were assessed using Cox proportional hazard regression models. RESULTS Coarseness (r=-0.382) on PET and ADCdiff (r=0.534) on MRI were significantly correlated with the proportion of stroma. The best imaging biomarkers for the 2-year RFS prediction were coarseness (AUC=0.741) and ADCdiff (AUC=0.779). Multivariate analysis showed that coarseness (hazard ratio=10.549, 95% confidence interval=2.544-43.748, p=0.001) was an independent prognostic factor for RFS. CONCLUSION Heterogeneity imaging parameters are significantly associated with the tumour-stroma ratio. These imaging biomarkers may help to facilitate the risk stratification for tumour recurrence in HNSCC.
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Affiliation(s)
- J W Choi
- Department of Radiology, Ajou University School of Medicine, Suwon, Republic of Korea
| | - D Lee
- Department of Pathology, Ajou University School of Medicine, Suwon, Republic of Korea
| | - S H Hyun
- Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - M Han
- Department of Radiology, Ajou University School of Medicine, Suwon, Republic of Korea
| | - J-H Kim
- Department of Pathology, Ajou University School of Medicine, Suwon, Republic of Korea
| | - S J Lee
- Department of Nuclear Medicine, Ajou University School of Medicine, Suwon, Republic of Korea.
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Jeong H, Jang SK, Hong CY, Kim SH, Lee SY, Lee SM, Choi JW, Choi IG. Levulinic acid production by two-step acid-catalyzed treatment of Quercus mongolica using dilute sulfuric acid. Bioresour Technol 2017; 225:183-190. [PMID: 27889477 DOI: 10.1016/j.biortech.2016.11.063] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [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: 09/20/2016] [Revised: 11/14/2016] [Accepted: 11/15/2016] [Indexed: 06/06/2023]
Abstract
The objectives of this research were to produce a levulinic acid by two-step acid-catalyzed treatment of Quercus mongolica and to investigate the effect of treatment parameter (reaction temperature range: 100-230°C; sulfuric acid (SA) concentration range: 0-2%) on the levulinic acid yield. After 1st step acid-catalyzed treatment, most of the hemicellulosic C5 sugars (15.6gg/100gbiomass) were released into the liquid hydrolysate at the reaction temperature of 150°C in 1% SA; the solid fraction, which contained 53.5% of the C6 sugars, was resistant to further loss of C6 sugars. Subsequently, 2nd step acid-catalyzed treatment of the solid fractions was performed under more severe conditions. Finally, 16.5g/100g biomass of levulinic acid was produced at the reaction temperature of 200°C in 2% SA, corresponding to a higher conversion rate than during single-step treatment.
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Affiliation(s)
- Hanseob Jeong
- Division of Wood Chemistry & Microbiology, Department of Forest Products, National Institute of Forest Science, Seoul 02455, Republic of Korea
| | - Soo-Kyeong Jang
- Department of Forest Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Chang-Young Hong
- Division of Wood Chemistry & Microbiology, Department of Forest Products, National Institute of Forest Science, Seoul 02455, Republic of Korea
| | - Seon-Hong Kim
- Department of Forest Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Su-Yeon Lee
- Division of Wood Chemistry & Microbiology, Department of Forest Products, National Institute of Forest Science, Seoul 02455, Republic of Korea
| | - Soo Min Lee
- Division of Wood Chemistry & Microbiology, Department of Forest Products, National Institute of Forest Science, Seoul 02455, Republic of Korea
| | - Joon Weon Choi
- Graduate School of International Agricultural Technology, Seoul National University, Pyeongchang 25354, Republic of Korea; Institute of Green-Bio Science and Technology, Seoul National University, Pyeongchang 25354, Republic of Korea
| | - In-Gyu Choi
- Department of Forest Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea; Institute of Green-Bio Science and Technology, Seoul National University, Pyeongchang 25354, Republic of Korea; Research Institute of Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea.
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Oh S, Choi HS, Choi IG, Choi JW. Evaluation of hydrodeoxygenation reactivity of pyrolysis bio-oil with various Ni-based catalysts for improvement of fuel properties. RSC Adv 2017. [DOI: 10.1039/c7ra01166k] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
To improve bio-oil quality, deoxygenation degree and energy efficiency of the process, Ni/C, Ni/SBA-15 and Ni/Al-SBA-15 were synthesized and subjected to hydrodeoxgygenative upgrading process of bio-oil.
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Affiliation(s)
- Shinyoung Oh
- Department of Forest Sciences
- Seoul National University
- Seoul
- Korea
| | - Hang Seok Choi
- Department of Environmental Engineering
- Yonsei University
- Wonju 220-710
- Korea
| | - In-Gyu Choi
- Department of Forest Sciences
- Seoul National University
- Seoul
- Korea
| | - Joon Weon Choi
- Graduate School of International Agricultural Technology
- Institute of Green-Bio Science and Technology
- Seoul National University
- Pyeongchang 232-916
- Korea
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Kim JY, Park SY, Lee JH, Choi IG, Choi JW. Sequential solvent fractionation of lignin for selective production of monoaromatics by Ru catalyzed ethanolysis. RSC Adv 2017. [DOI: 10.1039/c7ra11541e] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The purpose of this study was to investigate the impact of lignin structure, especially its average molecular weight (Mw) on the distribution of catalytically depolymerized products.
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Affiliation(s)
- Jae-Young Kim
- Department of Forest Sciences
- Research Institute for Agriculture and Life Science
- Seoul National University
- Seoul
- Republic of Korea
| | - Shin Young Park
- Department of Forest Sciences
- Research Institute for Agriculture and Life Science
- Seoul National University
- Seoul
- Republic of Korea
| | - Jae Hoon Lee
- Department of Forest Sciences
- Research Institute for Agriculture and Life Science
- Seoul National University
- Seoul
- Republic of Korea
| | - In-Gyu Choi
- Department of Forest Sciences
- Research Institute for Agriculture and Life Science
- Seoul National University
- Seoul
- Republic of Korea
| | - Joon Weon Choi
- Graduate School of International Agricultural Technology
- Institute of Green-Bio Science and Technology
- Seoul National University
- Pyeongchang 232-916
- Republic of Korea
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Hwang H, Sahin O, Choi JW. Manufacturing a super-active carbon using fast pyrolysis char from biomass and correlation study on structural features and phenol adsorption. RSC Adv 2017. [DOI: 10.1039/c7ra06910c] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
An in-depth study of activated carbon using fast pyrolysis char and correlation between its properties and phenol adsorption were discussed.
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Affiliation(s)
- Hyewon Hwang
- Department of Forest Sciences
- Seoul National University
- Seoul
- Korea
| | - Olga Sahin
- Institute of Catalytic Research (IKFT)
- Karlsruhe Institute of Technology
- Germany
| | - Joon Weon Choi
- Graduate School of International Agricultural Technology
- Institute of Green-Bio Science and Technology
- Seoul National University
- Pyeongchang
- Korea
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Kim SS, Han GS, Kim GN, Koo DS, Kim IG, Choi JW. Advanced remediation of uranium-contaminated soil. J Environ Radioact 2016; 164:239-244. [PMID: 27522327 DOI: 10.1016/j.jenvrad.2016.08.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [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: 03/29/2016] [Revised: 08/02/2016] [Accepted: 08/03/2016] [Indexed: 06/06/2023]
Abstract
The existing decontamination method using electrokinetic equipment after acidic washing for uranium-contaminated soil requires a long decontamination time and a significant amount of electric power. However, after soil washing, with a sulfuric acid solution and an oxidant at 65 °C, the removal of the muddy solution using a 100 mesh sieve can decrease the radioactivity of the remaining coarse soil to the clearance level. Therefore, only a small amount of fine soil collected from the muddy solution requires the electrokinetic process for its decontamination. Furthermore, it is found that the selective removal of uranium from the sulfuric washing solution is not obtained using an anion exchanger but rather using a cation exchanger, unexpectedly. More than 90% of the uranium in the soil washing solutions is adsorbed on the S-950 resin, and 87% of the uranium adsorbed on S-950 is desorbed by washing with a 0.5 M Na2CO3 solution at 60 °C.
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Affiliation(s)
- S S Kim
- Decontamination and Decommissioning Research Div., Korea Atomic Energy Research Institute, 1045 Daedeok-daero, Yusong-gu, Daejeon, 305-353, Republic of Korea.
| | - G S Han
- Decontamination and Decommissioning Research Div., Korea Atomic Energy Research Institute, 1045 Daedeok-daero, Yusong-gu, Daejeon, 305-353, Republic of Korea
| | - G N Kim
- Decontamination and Decommissioning Research Div., Korea Atomic Energy Research Institute, 1045 Daedeok-daero, Yusong-gu, Daejeon, 305-353, Republic of Korea
| | - D S Koo
- Decontamination and Decommissioning Research Div., Korea Atomic Energy Research Institute, 1045 Daedeok-daero, Yusong-gu, Daejeon, 305-353, Republic of Korea
| | - I G Kim
- Decontamination and Decommissioning Research Div., Korea Atomic Energy Research Institute, 1045 Daedeok-daero, Yusong-gu, Daejeon, 305-353, Republic of Korea
| | - J W Choi
- Decontamination and Decommissioning Research Div., Korea Atomic Energy Research Institute, 1045 Daedeok-daero, Yusong-gu, Daejeon, 305-353, Republic of Korea
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Kim KH, Tandi TE, Choi JW, Moon JM, Kim MS. Middle East respiratory syndrome coronavirus (MERS-CoV) outbreak in South Korea, 2015: epidemiology, characteristics and public health implications. J Hosp Infect 2016; 95:207-213. [PMID: 28153558 PMCID: PMC7114867 DOI: 10.1016/j.jhin.2016.10.008] [Citation(s) in RCA: 184] [Impact Index Per Article: 23.0] [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: 08/24/2016] [Accepted: 10/07/2016] [Indexed: 12/31/2022]
Abstract
Background Since the first case of Middle East respiratory syndrome coronavirus (MERS-CoV) in South Korea was reported on 20th May 2015, there have been 186 confirmed cases, 38 deaths and 16,752 suspected cases. Previously published research on South Korea's MERS outbreak was limited to the early stages, when few data were available. Now that the outbreak has ended, albeit unofficially, a more comprehensive review is appropriate. Methods Data were obtained through the MERS portal by the Ministry for Health and Welfare (MOHW) and Korea Centres for Disease Control and Prevention, press releases by MOHW, and reports by the MERS Policy Committee of the Korean Medical Association. Cases were analysed for general characteristics, exposure source, timeline and infection generation. Sex, age and underlying diseases were analysed for the 38 deaths. Findings Beginning with the index case that infected 28 others, an in-depth analysis was conducted. The average age was 55 years, which was a little higher than the global average of 50 years. As in most other countries, more men than women were affected. The case fatality rate was 19.9%, which was lower than the global rate of 38.7% and the rate in Saudi Arabia (36.5%). In total, 184 patients were infected nosocomially and there were no community-acquired infections. The main underlying diseases were respiratory diseases, cancer and hypertension. The main contributors to the outbreak were late diagnosis, quarantine failure of ‘super spreaders’, familial care-giving and visiting, non-disclosure by patients, poor communication by the South Korean Government, inadequate hospital infection management, and ‘doctor shopping’. The outbreak was entirely nosocomial, and was largely attributable to infection management and policy failures, rather than biomedical factors.
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Affiliation(s)
- K H Kim
- Institute for Occupational and Environmental Health, Korea University, Seoul, Korea
| | - T E Tandi
- Institute for Occupational and Environmental Health, Korea University, Seoul, Korea; Graduate School of Public Health, Korea University, Seoul, Korea; Department of Preventive Medicine, Korea University College of Medicine, Seoul, Korea; Ministry of Public Health Yaounde, Yaounde, Cameroon
| | - J W Choi
- Institute for Occupational and Environmental Health, Korea University, Seoul, Korea; Graduate School of Public Health, Korea University, Seoul, Korea; Department of Preventive Medicine, Korea University College of Medicine, Seoul, Korea; MERS Policy Committee of the Korean Medical Association, Seoul, Korea.
| | - J M Moon
- Institute for Occupational and Environmental Health, Korea University, Seoul, Korea; Graduate School of Public Health, Korea University, Seoul, Korea
| | - M S Kim
- Institute for Occupational and Environmental Health, Korea University, Seoul, Korea; Graduate School of Public Health, Korea University, Seoul, Korea
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Kim YW, Hong JM, Park DG, Choi JW, Kang DH, Kim YS, Zaidat OO, Demchuk AM, Hwang YH, Lee JS. Effect of Intracranial Atherosclerotic Disease on Endovascular Treatment for Patients with Acute Vertebrobasilar Occlusion. AJNR Am J Neuroradiol 2016; 37:2072-2078. [PMID: 27313131 DOI: 10.3174/ajnr.a4844] [Citation(s) in RCA: 105] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2015] [Accepted: 04/24/2016] [Indexed: 02/01/2023]
Abstract
BACKGROUND AND PURPOSE Although intracranial atherosclerotic disease is often encountered during endovascular treatment for acute vertebrobasilar occlusions, its clinical implication is not well-known. We aimed to evaluate whether intracranial atherosclerotic disease influences the clinical outcomes following endovascular treatment of acute vertebrobasilar occlusive stroke. MATERIALS AND METHODS Fifty-one patients with acute vertebrobasilar occlusive stroke were included. The onset-to-groin puncture time was ≤12 hours, and aspiration- or stent-based thrombectomy was used as the primary treatment method. Following primary endovascular treatment, intracranial atherosclerotic disease (IAD group) was angiographically diagnosed when a fixed focal stenosis was observed at the occlusion site, whereas embolism (embolic group) was diagnosed if no stenosis was observed. Clinical and treatment variables were compared in both groups, and IAD was evaluated as a prognostic factor for clinical outcomes. RESULTS The baseline NIHSS score tended to be lower (14 versus 22, P = .097) in the IAD group (n = 19) than in the embolic group (n = 32). The procedural time was longer in the IAD group (96 versus 61 minutes, P = .002), despite similar rates of TICI 2b-3 (89.5% versus 87.5%, P = 1.000). The NIHSS score at 7 days was higher (21 versus 8, P = .060) and poor outcomes (mRS 4-6 at 3 months) were more frequent in the IAD group (73.7% versus 43.8%, P = .038). IAD (odds ratio, 5.469; 95% CI, 1.09-27.58; P = .040) was independently associated with poor outcomes. CONCLUSIONS An arterial occlusion related to IAD was associated with a longer procedural time and poorer clinical outcome. Further studies are warranted to elucidate the appropriate endovascular strategy.
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Affiliation(s)
- Y W Kim
- From the Departments of Neurology (Y.W.K., Y.H.H.).,Radiology (Y.W.K., D.-H.K., Y.S.K.)
| | - J M Hong
- Departments of Neurology (J.M.H., D.G.P., J.S.L.)
| | - D G Park
- Departments of Neurology (J.M.H., D.G.P., J.S.L.)
| | - J W Choi
- Radiology (J.W.C.), Ajou University School of Medicine and Hospital, Suwon, Republic of Korea
| | - D-H Kang
- Radiology (Y.W.K., D.-H.K., Y.S.K.).,Neurosurgery (D.-H.K.), Kyungpook National University School of Medicine and Hospital, Daegu, Republic of Korea
| | - Y S Kim
- Radiology (Y.W.K., D.-H.K., Y.S.K.)
| | - O O Zaidat
- Radiology (J.W.C.), Ajou University School of Medicine and Hospital, Suwon, Republic of Korea
| | - A M Demchuk
- Radiology (J.W.C.), Ajou University School of Medicine and Hospital, Suwon, Republic of Korea
| | - Y H Hwang
- From the Departments of Neurology (Y.W.K., Y.H.H.)
| | - J S Lee
- Departments of Neurology (J.M.H., D.G.P., J.S.L.)
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Patra JK, Das G, Choi JW, Baek KH. Antibacterial Effects of Pyrolysis Oil Against Salmonella Typhimurium and Escherichia coli. Foodborne Pathog Dis 2016; 13:13-20. [DOI: 10.1089/fpd.2015.2040] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
| | - Gitishree Das
- School of Biotechnology, Yeungnam University, Gyeongsan, Gyeongbuk, Korea
| | - Joon Weon Choi
- Graduate School of International Agricultural Technology and Institute of Green-Bio Science and Technology, Seoul National University, Pyeongchang, Korea
| | - Kwang-Hyun Baek
- School of Biotechnology, Yeungnam University, Gyeongsan, Gyeongbuk, Korea
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50
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Park J, Oh S, Kim JY, Park SY, Song IK, Choi JW. Comparison of degradation features of lignin to phenols over Pt catalysts prepared with various forms of carbon supports. RSC Adv 2016. [DOI: 10.1039/c5ra21875f] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Soda lignin separated from wheat straw was successfully depolymerized to produce a phenol-rich oil fraction over various carbon-supported platinum (Pt) catalysts.
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Affiliation(s)
- Jeesu Park
- Department of Forest Sciences
- College of Agricultural and Life Science
- Seoul National University
- Seoul
- Republic of Korea
| | - Shinyoung Oh
- Department of Forest Sciences
- College of Agricultural and Life Science
- Seoul National University
- Seoul
- Republic of Korea
| | - Jae-Young Kim
- Department of Forest Sciences
- College of Agricultural and Life Science
- Seoul National University
- Seoul
- Republic of Korea
| | - Shin Young Park
- Department of Forest Sciences
- College of Agricultural and Life Science
- Seoul National University
- Seoul
- Republic of Korea
| | - In Kyu Song
- School of Chemical and Biological Engineering
- Institute of Chemical Processes
- Seoul National University
- Seoul
- Korea
| | - Joon Weon Choi
- Graduate School of International Agricultural Technology and Institute of Green-Bio Science and Technology
- Seoul National University
- Pyeongchang 232-916
- Republic of Korea
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