378 results on '"Hyun-su Kim"'
Search Results
2. Clinicopathologic implications of Myb and Beta-catenin expression in adenoid cystic carcinoma
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Susan Park, Manali Vora, Annemieke van Zante, Joseph Humtsoe, Hyun-Su Kim, Sue Yom, Shweta Agarwal, and Patrick Ha
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Adenoid cystic carcinoma ,Myb ,Beta-catenin ,Prognostic indicator ,Surgery ,RD1-811 - Abstract
Abstract Background Adenoid cystic carcinoma (ACC) is the second most common malignancy of the salivary glands, accounting for ~ 1% of malignant tumors of the head and neck region and 10% of salivary gland neoplasms. Predicting the long-term outcomes of patients with ACC is still challenging, as reliable prognostic biomarkers are not available. Among salivary gland tumors, Myb overexpression is highly specific for ACC. In addition, the MYB-NF1B fusion translocation is a hallmark of ACC, and although the detection of this translocation does not appear to impact prognosis, the MYB-NF1B fusion is also implicated in MYB upregulation. Myb has recently been identified as an activator of the Wnt/β-catenin signaling pathway, and aberrant cytoplasmic expression of β-catenin has been observed in many salivary gland malignancies. In this study, we aim to analyze the impact of Myb and β-catenin expression on prognosis in ACC. Methods A tissue microarray constructed from archival tissue from 64 patients with ACC was stained for Myb and β-catenin; both localization and intensity were evaluated. In parallel, we abstracted demographic data, tumor characteristics, survival data, and outcomes, including local recurrence, regional recurrence, and distant metastasis from the medical record. Statistical analysis was performed. Results Our analysis supports that ACC patients negative for Myb by immunohistochemical methods have a higher risk of developing metastasis than patients with Myb staining (HR: 4.06, 95% CI: 1.02–14.96, p-value: 0.03). Although not statistically significant, cytoplasmic localization of β-catenin is may suggest a diminished rate of relapse-free survival (HR 2.45, 95%CI: 0.9–6.7, p = 0.08). Furthermore, Myb expression correlated with β-catenin expression, increasing 1.69 in staining intensity units with each increase in β-catenin staining intensity (p-value: 0.04). Conclusions Our study suggests that Myb expression is protective; Myb positive patients have diminished risk of distant metastasis. In contrast, there is a trend towards increased hazard of death in ACC patients with cytoplasmic β-catenin expression. Additional analyses will be necessary to establish Myb and β-catenin as independent protective and adverse biomarkers, respectively.
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- 2020
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3. Development of a Control Algorithm for a Semi-Active Mid-Story Isolation System Using Reinforcement Learning
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Hyun-Su Kim and Uksun Kim
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semi-active mid-story isolation system ,control algorithm ,reinforcement learning ,seismic response reduction ,magnetorheological damper ,deep q-network ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
The semi-active control system is widely used to reduce the seismic response of building structures. Its control performance mainly depends on the applied control algorithms. Various semi-active control algorithms have been developed to date. Recently, machine learning has been applied to various engineering fields and provided successful results. Because reinforcement learning (RL) has shown good performance for real-time decision-making problems, structural control engineers have become interested in RL. In this study, RL was applied to the development of a semi-active control algorithm. Among various RL methods, a Deep Q-network (DQN) was selected because of its successful application to many control problems. A sample building structure was constructed by using a semi-active mid-story isolation system (SMIS) with a magnetorheological damper. Artificial ground motions were generated for numerical simulation. In this study, the sample building structure and seismic excitation were used to make the RL environment. The reward of RL was designed to reduce the peak story drift and the isolation story drift. Skyhook and groundhook control algorithms were applied for comparative study. Based on numerical results, this paper shows that the proposed control algorithm can effectively reduce the seismic responses of building structures with a SMIS.
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- 2023
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4. Facile Gram-Scale Synthesis of Co3O4 Nanocrystal from Spent Lithium Ion Batteries and Its Electrocatalytic Application toward Oxygen Evolution Reaction
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Jaegon Kim, Ho-Geun Kim, Hyun-Su Kim, Cu Dang Van, Min Hyung Lee, and Ki-Wan Jeon
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recycling spent lithium ion battery ,Co3O4 nanoparticle ,oxygen evolution reaction ,electrocatalyst ,alkali leaching ,Chemistry ,QD1-999 - Abstract
In this study, we demonstrate a new approach to easily prepare spinel Co3O4 nanoparticles (s-Co3O4 NPs) in the gram-scale from the cathode of spent lithium ion batteries (SLIBs) by the alkali leaching of hexaamminecobalt(III) complex ions. As-obtained intermediate and final products were characterized with powder X-ray diffraction (PXRD), Ultraviolet-Visible (UV–Vis), Fourier transform infrared (FTIR), and Transmission electron microscopy (TEM). Additionally, the synthesized s-Co3O4 NPs showed better electrocatalytic properties toward the oxygen evolution reaction (OER) in comparison to previously reported Co3O4 NPs and nanowires, which could be due to the more exposed electrocatalytic active sites on the s-Co3O4 NPs. Moreover, the electrocatalytic activity of the s-Co3O4 NPs was comparable to the previously reported RuO2 catalysts. By taking advantage of the proposed recycling route, we would expect that various valuable transition metal oxide NPs could be prepared from SLIBs.
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- 2022
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5. Thermal Degradation Behavior of Ag Nanowire-Coated Transparent Conductive Film for Flexible Display Applications
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Jae-Yeon Kim, Hye-Young Kim, Hyun-Su Kim, Ki-Tae Yoo, Won-Jon Yang, and Jai-Won Byeon
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silver nanowire ,isothermal degradation ,electrical resistance ,overcoating ,Mining engineering. Metallurgy ,TN1-997 ,Materials of engineering and construction. Mechanics of materials ,TA401-492 - Abstract
For the reliable applications of silver nanowires, AgNW, which is used as a conductive transparent film in electronic devices, the isothermal degradation behaviors of AgNW films with and without overcoating were investigated. Accelerated isothermal degradation was performed as a function of temperature, time, and atmosphere. Electrical resistance and optical transmittance were measured and correlated with the microstructural damages, such as formation of oxide particles and fragmentations of AgNW, which were quantitatively determined from the scanning electron micrographs. The overcoating retarded the formation of oxide particles and subsequent fragmentations as well as resulting degradation in electrical resistance without affecting the optical transmittance.
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- 2019
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6. Heart rate recovery and blood pressure response during exercise testing in patients with microvascular angina
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Bong-Joon Kim, Eun-Ah Jo, Sung-Il Im, Hyun-Su Kim, Jung Ho Heo, and Kyoung-Im Cho
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Microvascular angina ,Cardiac autonomic function ,Heart rate recovery ,Medicine ,Internal medicine ,RC31-1245 - Abstract
Abstract Background Angina pectoris with a normal coronary angiogram, termed microvascular angina (MVA), is an important clinical entity; however, its causes remain unclear. Autonomic dysfunction is one of the possible causes. Therefore, this study aimed to investigate parasympathetic dysfunction assessed by heart rate recovery (HRR) and increased sympathetic activity assessed by exaggerated blood pressure (BP) response (EBPR) to exercise in MVA. Methods The study participants were consecutive patients with anginal chest pain who underwent both coronary angiography with an ergonovine provocation test and a treadmill exercise test between January 2008 and February 2015. Patients with significant coronary artery disease (coronary artery stenosis ≥50%) or significant coronary artery spasm (≥90%) were excluded. Based on the treadmill exercise test, patients were categorized into the microvascular angina (MVA) group (patients with uniform ST depression ≥1 mm) and the control group. HRR was defined as peak heart rate minus heart rate after a 1 min recovery; blunted HRR was defined as ≤12 beats/min. EBPR was defined as a peak exercise systolic BP ≥210 mmHg in men and ≥ 190 mmHg in women. These parameters were compared between patients with MVA and the controls. Results Among the 970 enrolled patients (mean age 53.1 years; female 59.0%), 191 (20.0%) were diagnosed with MVA. In baseline characteristics, the MVA group had older participants, female predominance, and a higher prevalence of hypertension. The MVA group showed significantly lower HRR 1 min (24.9 ± 15.9 vs. 31.3 ± 22.7, p
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- 2019
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7. Anti-hepatofibrosis effect of Allium senescens in activated hepatic stellate cells and thioacetamide-induced fibrosis rat model
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Gwang-Mo Shin, Sushruta Koppula, Yun-Jin Chae, Hyun-Su Kim, Jae-Dong Lee, Myong-Ki Kim, and MinDong Song
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liver fibrosis ,thioacetamide ,extracellular matrix ,apoptosis ,hydroxyproline ,Therapeutics. Pharmacology ,RM1-950 - Abstract
Context: Allium senescens Linn. (Liliaceae) (ASL) has been traditionally used in Korea and other Asian countries for improving digestive and liver functions. Objective: The anti-hepatofibrosis effect of ASL ethanol extract in cellular and experimental fibrosis rat model was investigated. Materials and methods: In vitro cell viability, cell cycle and apoptosis in hepatic stellate cells (HSCs) were studied using MTT assay, flow cytometry and Annexin V-FITC/PI staining. Thioacetamide (TAA; 200 mg/kg, i.p.)-induced liver fibrosis model using Sprague Dawley rats (n = 10) was developed in vivo by injecting TAA twice per week for 13 weeks. ASL (25 and 100 mg/kg) and silymarin (50 mg/kg) were administered through oral gavage 2 times per week from 7th to 13th week. Specific fibrotic-related biomarkers such as aspartate transaminase (AST), alanine transaminase (ALT), glutathione and hydroxyproline levels in serum were analyzed by spectrophotometer using commercial kits. Morphological, histopathological and fibrotic-related gene expression such as TGF-β, Col1α1 and α-SMA in liver tissues was estimated by hematoxylin and eosin staining, Picrosirius red stain and quantitative real-time polymerase chain reaction, respectively. Results: ASL (0.1 mg/mL) and silymarin (0.05 mg/mL) treatment induced apoptosis (4.06% and 8.67%) in activated HSC-T6 cells, compared with control group (3.7%). The altered morphology in activated primary HSCs was also restored by ASL (0.1 mg/mL) treatment. Further, ASL (100 and 25 mg/kg) ameliorated the TAA-induced altered fibrotic-related biomarkers, histopathological changes and fibrotic-related gene expression significantly (p
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- 2018
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8. Semi-active Outrigger Damping System for Seismic Protection of Building Structure
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Hyun-Su Kim and Joo-Won Kang
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damped outrigger system ,mr damper ,seismic response control ,fuzzy logic controller ,multi-objective optimization ,Architecture ,NA1-9428 ,Building construction ,TH1-9745 - Abstract
The outrigger structural system is one of the most widely used lateral load-resisting structural systems for high-rise buildings. To increase the energy dissipation capacity of the outrigger system, an outrigger damping system has been proposed as a novel energy dissipation system. In this system, the outrigger and perimeter columns are separate and vertical viscous dampers are equipped between the outrigger and perimeter columns. In this study, the control performance of a semi-active outrigger damping system for the seismic protection of a building structure was investigated. Semi-active damping devices, such as magnetorheological (MR) dampers instead of passive dampers, are installed vertically between the outrigger and perimeter columns to achieve large and adaptable energy dissipation. A fuzzy logic control algorithm was used to generate a command voltage sent to the semi-active MR dampers. A genetic algorithm was used to optimize the fuzzy logic controller. An artificial earthquake load was generated for the numerical simulation and a simplified numerical model of a damped outrigger system was developed. Numerical analyses showed that the semi-active damped outrigger system could effectively reduce both the displacement and acceleration responses of the tall buildings compared to a passive outrigger damper system.
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- 2017
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9. Application of quantitative light-induced fluorescence to determine the depth of demineralization of dental fluorosis in enamel microabrasion: a case report
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Tae-Young Park, Han-Sol Choi, Hee-Won Ku, Hyun-Su Kim, Yoo-Jin Lee, and Jeong-Bum Min
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Dentistry ,RK1-715 - Abstract
Enamel microabrasion has become accepted as a conservative, nonrestorative method of removing intrinsic and superficial dysmineralization defects from dental fluorosis, restoring esthetics with minimal loss of enamel. However, it can be difficult to determine if restoration is necessary in dental fluorosis, because the lesion depth is often not easily recognized. This case report presents a method for analysis of enamel hypoplasia that uses quantitative light-induced fluorescence (QLF) followed by a combination of enamel microabrasion with carbamide peroxide home bleaching. We describe the utility of QLF when selecting a conservative treatment plan and confirming treatment efficacy. In this case, the treatment plan was based on QLF analysis, and the selected combination treatment of microabrasion and bleaching had good results.
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- 2016
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10. Development of Seismic Response Simulation Model for Building Structures with Semi-Active Control Devices Using Recurrent Neural Network
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Hyun-Su Kim
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recurrent neural network ,seismic response simulation ,semi-active control device ,magnetorheological damper ,deep learning ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
A structural analysis model to represent the dynamic behavior of building structure is required to develop a semi-active seismic response control system. Although the finite element method (FEM) is the most widely used method for seismic response analysis, when the FEM is applied to the dynamic analysis of building structures with nonlinear semi-active control devices, the computational effort required for the simulation for optimal design of the semi-active control system can be considerable. To solve this problem, this paper used recurrent neural network (RNN) to make a time history response simulation model for building structures with a semi-active control system. Example structures were selected of an 11-story building structure with a semi-active tuned mass damper (TMD), and a 27-story building having a semi-active mid-story isolation system. A magnetorheological damper was used as the semi-active control device. Five historical earthquakes and five artificial ground motions were used as ground excitations to train the RNN model. Two artificial ground motions and one historical earthquake, which were not used for training, were used to verify the developed the RNN model. Compared to the FEM model, the developed RNN model could effectively provide very accurate seismic responses, with significantly reduced computational cost.
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- 2020
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11. Restorative Self-Image of Rough-Line Grids: Application to Coherent EUV Talbot Lithography
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Hyun-su Kim, Wei Li, Mario C. Marconi, William S. Brocklesby, and Larissa Juschkin
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Applied optics. Photonics ,TA1501-1820 ,Optics. Light ,QC350-467 - Abstract
Self-imaging is a well-known optical phenomenon produced by diffraction of a coherent beam in a periodic structure. The self-imaging effect (or Talbot effect) replicates the field intensity at a periodic mask in certain planes, effectively producing in those planes an image of the mask. However, the effect has not been analyzed for a rough-line grid from the point of view of the fidelity of the image. In this paper, we investigate the restorative effect of the self-image applied to the lithography of gratings with rough lines. This paper is applied to characterize a Talbot lithography experiment implemented in the extreme ultraviolet. With the self-imaging technique, a mask with grid patterns having bumps randomly placed along the line edges reproduces a grid pattern with smoothed line edges. Simulation explores the approach further for the cases of sub-100-nm pitch grids.
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- 2016
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12. CoAP-Based Mobility Management for the Internet of Things
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Seung-Man Chun, Hyun-Su Kim, and Jong-Tae Park
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IoT mobility management ,web-based mobility management ,WoT mobility management ,Chemical technology ,TP1-1185 - Abstract
Most of the current mobility management protocols such as Mobile IP and its variants standardized by the IETF may not be suitable to support mobility management for Web-based applications in an Internet of Things (IoT) environment. This is because the sensor nodes have limited power capacity, usually operating in sleep/wakeup mode in a constrained wireless network. In addition, sometimes the sensor nodes may act as the server using the CoAP protocol in an IoT environment. This makes it difficult for Web clients to properly retrieve the sensing data from the mobile sensor nodes in an IoT environment. In this article, we propose a mobility management protocol, named CoMP, which can effectively retrieve the sensing data of sensor nodes while they are moving. The salient feature of CoMP is that it makes use of the IETF CoAP protocol for mobility management, instead of using Mobile IP. Thus CoMP can eliminates the additional signaling overhead of Mobile IP, provides reliable mobility management, and prevents the packet loss. CoMP employs a separate location management server to keep track of the location of the mobile sensor nodes. In order to prevent the loss of important sensing data during movement, a holding mode of operation has been introduced. All the signaling procedures including discovery, registration, binding and holding have been designed by extending the IETF CoAP protocol. The numerical analysis and simulation have been done for performance evaluation in terms of the handover latency and packet loss. The results show that the proposed CoMP is superior to previous mobility management protocols, i.e., Mobile IPv4/v6 (MIPv4/v6), Hierarchical Mobile IPv4/v6 (HMIPv4/v6), in terms of the handover latency and packet loss.
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- 2015
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13. The Clinical Report on 2 Cases of Lateral Epicondylitis Treated by Scolopendrid Aquacupucture Therapy
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Jang-Woo Park, Jae-Pil Hwang, Jun-Hyuk Kang, Hyun-Su Kim, Dong-Seok Heo, Il-Ji Yoon, and Min-Seok Oh
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Scolopendrid aquacupucture ,Lateral epicondylitis ,Injection ,Pressure pain threshold ,Medicine ,Miscellaneous systems and treatments ,RZ409.7-999 ,Therapeutics. Pharmacology ,RM1-950 - Abstract
Objective : The purpose of this study is to examine if scolopendrid acuacupucture may be effective to the lateral epicondylitis. Methods : Using scolopendrid aquacupucture, we injected a small dose of it to the affected area and operated 2 pre and post treatment test; VAS(visual analogue scale), PPT(pressure pain threshold). Results : The scolopendrid aquacupucture treatment led to improvement in the pain and symptom of lateral epicondylitis by all efficacy measures. After scolopendrid aquacupucture treatment, there was improvement in VAS, PPT. Conclusion : This results suggest that scolopendrid aquacupucture is good method for treatment of lateral epicondylitis. so we suggest the possibility to use this new remedy for the lateral epicondylitis.
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- 2006
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14. Impact of Gender on the Association of Epicardial Fat Thickness, Obesity, and Circadian Blood Pressure Pattern in Hypertensive Patients
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In Kyoung Shim, Kyoung-Im Cho, Hyun-Su Kim, Jung-Ho Heo, and Tae Joon Cha
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Diseases of the endocrine glands. Clinical endocrinology ,RC648-665 - Abstract
This study aimed to investigate the effects of gender on the association between epicardial fat thickness (EFT) and circadian blood pressure (BP) changes in patients with recently diagnosed essential hypertension (EH). A total of 441 patients with EH (male/female: 236/205, mean age: 50.7 ± 13.8) and 83 control patients underwent 24-hour ambulatory BP monitoring and echocardiography. Obese EH patients had higher circadian BP profile with BP variability, wall thickness, and left ventricular mass than nonobese EH patients and controls (all p’s
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- 2015
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15. Attenuation of acetylcholine activated potassium current (I KACh) by simvastatin, not pravastatin in mouse atrial cardiomyocyte: possible atrial fibrillation preventing effects of statin.
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Kyoung-Im Cho, Tae-Joon Cha, Su-Jin Lee, In-Kyeung Shim, Yin Hua Zhang, Jung-Ho Heo, Hyun-Su Kim, Sung Joon Kim, Kyoung-Lyoung Kim, and Jae-Woo Lee
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Medicine ,Science - Abstract
Statins, 3-hydroxy-3-methyl-glutaryl-CoA reductase inhibitors, are associated with the prevention of atrial fibrillation (AF) by pleiotropic effects. Recent clinical trial studies have demonstrated conflicting results on anti-arrhythmia between lipophilic and hydrophilic statins. However, the underlying mechanisms responsible for anti-arrhythmogenic effects of statins are largely unexplored. In this study, we evaluated the different roles of lipophilic and hydrophilic statins (simvastatin and pravastatin, respectively) in acetylcholine (100 µM)-activated K+ current (IKACh, recorded by nystatin-perforated whole cell patch clamp technique) which are important for AF initiation and maintenance in mouse atrial cardiomyocytes. Our results showed that simvastatin (1-10 µM) inhibited both peak and quasi-steady-state IKACh in a dose-dependent manner. In contrast, pravastatin (10 µM) had no effect on IKACh. Supplementation of substrates for the synthesis of cholesterol (mevalonate, geranylgeranyl pyrophosphate or farnesyl pyrophosphate) did not reverse the effect of simvastatin on IKACh, suggesting a cholesterol-independent effect on IKACh. Furthermore, supplementation of phosphatidylinositol 4,5-bisphosphate, extracellular perfusion of phospholipase C inhibitor or a protein kinase C (PKC) inhibitor had no effect on the inhibitory activity of simvastatin on IKACh. Simvastatin also inhibits adenosine activated IKACh, however, simvastatin does not inhibit IKACh after activated by intracellular loading of GTP gamma S. Importantly, shortening of the action potential duration by acetylcholine was restored by simvastatin but not by pravastatin. Together, these findings demonstrate that lipophilic statins but not hydrophilic statins attenuate IKACh in atrial cardiomyocytes via a mechanism that is independent of cholesterol synthesis or PKC pathway, but may be via the blockade of acetylcholine binding site. Our results may provide important background information for the use of statins in patients with AF.
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- 2014
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16. The Impact of Slow Infusion Intermittent Feeding on Gavage Feeding-Associated Cardiorespiratory Deterioration in Neonatal Intensive Care Unit Infants
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Mi Jin Kim, Hyun Su Kim, Young Hwa Jung, and Chang Won Choi
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General Medicine - Abstract
Purpose: Infants in the neonatal intensive care unit (NICU) often show cardiorespiratory deterioration during gavage feeding. We aimed to determine whether slow infusion intermittent feeding (SIIF) can reduce respiratory deterioration during gavage feeding in preterm infants in the NICU.Methods: Data on preterm infants whose gavage feeding method was changed to SIIF (1-hour infusion with an infusion pump and 2-hour rest within a 3-hour interval) from bolus gravity feeding (2- or 3-hour interval) due to feeding-associated cardiorespiratory deterioration were retrospectively reviewed. A significant cardiorespiratory event was defined as a saturation level below 80% or heart rate below 80 bpm. We compared the frequency of cardiorespiratory events and the level of respiratory support 24 hours before and after the application of SIIF.Results: A total of 34 infants were enrolled and analyzed. The total frequency of desaturation or bradycardia significantly decreased after SIIF application (8.94 vs. 5.03, P=0.001). The frequency of feedingrelated bradycardia and desaturation also significantly decreased (4.15 vs. 1.68, P=0.008). Out of 34 patients, 11 (32.4%) had a decreased level of ventilator support within 1 day after SIIF. The respiratory severity scores of the 10 patients who received invasive ventilator support decreased significantly after SIIF (5.24 vs. 4.59, P=0.032).Conclusion: SIIF significantly decreased gavage feedingassociated cardiorespiratory events and reduced respiratory support in approximately onethird of subjects. Therefore, SIIF may be a therapeutic option for gavage feedassociated respiratory deterioration in preterm infants in the NICU.
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- 2023
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17. Stable mode-locking region analysis of all normal dispersion optical fiber laser by measuring polarization state inside a resonator
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Myeongjae Jang, Jeonghyun Jang, Sumin Moon, and Hyun Su Kim
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General Physics and Astronomy - Published
- 2022
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18. Effect of numerical truncation error on implicit finite difference methods in groundwater transport models
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Sruthi, K. V. and Hyun-su, Kim
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- 2016
19. Structural Congeners of Izenamides Responsible for Cathepsin D Inhibition: Insights from Synthesis-Derived Elucidation
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Hyun Su Kim, Hyejin Kong, Taewoo Kim, Changjin Lim, Seungbeom Lee, Seok-Ho Kim, and Young-Ger Suh
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marine cyanobacteria ,izenamides ,cathepsin D ,linear depsipeptides ,statine ,Drug Discovery ,Pharmaceutical Science ,Pharmacology, Toxicology and Pharmaceutics (miscellaneous) - Abstract
This study aimed to elucidate the structural congeners of natural izenamides A, B, and C (1–3) responsible for cathepsin D (CTSD) inhibition. Structurally modified izenamides were synthesized and biologically evaluated, and their biologically important core structures were identified. We confirmed that the natural statine (Sta) unit (3S,4S)-γ-amino-β-hydroxy acid is a requisite core structure of izenamides for inhibition of CTSD, which is closely related to the pathophysiological roles in numerous human diseases. Interestingly, the statine-incorporated izenamide C variant (7) and 18-epi-izenamide B variant (8) exhibited more potent CTSD-inhibitory activities than natural izenamides.
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- 2023
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20. Data from Newly Identified Members of FGFR1 Splice Variants Engage in Cross-talk with AXL/AKT Axis in Salivary Adenoid Cystic Carcinoma
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Patrick K. Ha, Hyunseok Kang, Elana J. Fertig, Alexander V. Favorov, Michael Considine, Bahman Afsari, Luigi Marchionni, Bhumsuk Keam, Shizhang Ling, Brandon Leonard, Hyun-Su Kim, and Joseph O. Humtsoe
- Abstract
Adenoid cystic carcinoma (ACC) is the second most common malignancy of the salivary gland. Although characterized as an indolent tumor, ACC often leads to incurable metastatic disease. Patients with ACC respond poorly to currently available therapeutic drugs and factors contributing to the limited response remain unknown. Determining the role of molecular alterations frequently occurring in ACC may clarify ACC tumorigenesis and advance the development of effective treatment strategies. Applying Splice Expression Variant Analysis and outlier statistics on RNA sequencing of primary ACC tumors and matched normal salivary gland tissues, we identified multiple alternative splicing events (ASE) of genes specific to ACC. In ACC cells and patient-derived xenografts, FGFR1 was a uniquely expressed ASE. Detailed PCR analysis identified three novel, truncated, intracellular domain-lacking FGFR1 variants (FGFR1v). Cloning and expression analysis suggest that the three FGFR1v are cell surface proteins, that expression of FGFR1v augmented pAKT activity, and that cells became more resistant to pharmacologic FGFR1 inhibitor. FGFR1v-induced AKT activation was associated with AXL function, and inhibition of AXL activity in FGFR1v knockdown cells led to enhanced cytotoxicity in ACC. Moreover, cell killing effect was increased by dual inhibition of AXL and FGFR1 in ACC cells. This study demonstrates that these previously undescribed FGFR1v cooperate with AXL and desensitize cells to FGFR1 inhibitor, which supports further investigation into combined FGFR1 and AXL inhibition as an effective ACC therapy.This study identifies several FGFR1 variants that function through the AXL/AKT signaling pathway independent of FGF/FGFR1, desensitizing cells to FGFR1 inhibitor suggestive of a potential resistance mechanism in ACC.Significance:This study identifies several FGFR1 variants that function through the AXL/AKT signaling pathway independent of FGF/FGFR1, desensitizing cells to FGFR1 inhibitor, suggestive of a potential resistance mechanism in ACC.
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- 2023
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21. Supplementary Data from Newly Identified Members of FGFR1 Splice Variants Engage in Cross-talk with AXL/AKT Axis in Salivary Adenoid Cystic Carcinoma
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Patrick K. Ha, Hyunseok Kang, Elana J. Fertig, Alexander V. Favorov, Michael Considine, Bahman Afsari, Luigi Marchionni, Bhumsuk Keam, Shizhang Ling, Brandon Leonard, Hyun-Su Kim, and Joseph O. Humtsoe
- Abstract
Supplemental Data S1 provides description on the ACC-01-XP xenograft development using ACC-01 cell line and shows list of PCR primers and other reagents used in the study. Supplemental Data S2 shows list of alternative splicing events identified in ACC compared to normal salivary gland tissue. Supplemental Data S3 shows nucleotides and corresponding amino acid composition of the three novel FGFR1 splice variants. Figure S1 shows ASE genes in PI3K-AKT signaling pathway enrichment using the Enrichr web tool. Figure S2 shows characterization of FGFR1v and impact on cell growth following siRNA-mediated knockdown. Figure S3 shows FGFR1v stability analysis and its effect on signaling and resistance to FGFR1 inhibitor. Figure S4 shows FGFR1v-mediated AKT signaling is independent on EGFR but supports the involvement of AXL. Figure S5 shows supportive expression and activities of FGFR1v in HACC-2A cells.
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- 2023
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22. The evaluation of effect on extracurricular self-development program : Focused on cadaver anatomy programs and language study abroad
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Hyun Su Kim, Hyun Jung Lee, and Dae Hu Kim
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- 2021
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23. Effects of the beta-blocker carvedilol on arrhythmia and long-term clinical outcomes in benign prostate hypertrophy patients.
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Soo Jin Kim, Han Su Park, Pil Moon Kang, Bong Joon Kim, Hyun Su Kim, Jung Ho Heo, Taek Sang Kim, and Sung Il Im
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- 2023
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24. Magnetic resonance imaging-based lower limb muscle evaluation in Charcot-Marie-Tooth disease type 1A patients and its correlation with clinical data
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Yeo Jin Kim, Hyun Su Kim, Ji Hyun Lee, Young Cheol Yoon, and Byung-Ok Choi
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Multidisciplinary ,Lower Extremity ,Thigh ,Charcot-Marie-Tooth Disease ,Muscles ,Humans ,Magnetic Resonance Imaging - Abstract
We aimed to derive comprehensive MRI parameters that reflect intramuscular fat infiltration severity for designated lower extremity levels, based on semiquantitative analyses in Charcot-Marie-Tooth disease type 1A (CMT1A) patients. We reviewed lower extremity MRIs of 116 CMT1A patients. Intramuscular fat infiltration grading using the Mercuri scale was performed for the non-dominant lower extremity at three levels (proximal, mid, and distal) for the thigh and at two levels (proximal and distal) for the lower leg. Based on MRI results, the following parameters were calculated for each level and for entire muscles: fat infiltration proportion (FIP), significant fat infiltration proportion (SigFIP), and severe fat infiltration proportion (SevFIP). The relationships between the MRI parameters and clinical data were evaluated using Spearman’s correlation analysis. FIP, SigFIP, and SevFIP measured for entire muscles significantly correlated with Charcot-Marie-Tooth Neuropathy Score (p p p = 0.0003, 0.0010, and 0.0011), and disease duration (p
- Published
- 2022
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25. Diffusion-weighted and dynamic contrast-enhanced magnetic resonance imaging after radiation therapy for bone metastases in patients with hepatocellular carcinoma
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Gyu Sang Yoo, Ji Hyun Lee, Hee Chul Park, Young Cheol Yoon, and Hyun Su Kim
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Adult ,Male ,Carcinoma, Hepatocellular ,Intraclass correlation ,medicine.medical_treatment ,Science ,Contrast Media ,Bone Neoplasms ,Article ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,Image Processing, Computer-Assisted ,medicine ,Humans ,Effective diffusion coefficient ,Prospective Studies ,Prospective cohort study ,Aged ,Multidisciplinary ,Radiotherapy ,medicine.diagnostic_test ,business.industry ,Liver Neoplasms ,Magnetic resonance imaging ,Middle Aged ,Prognosis ,medicine.disease ,Radiation therapy ,Diffusion Magnetic Resonance Imaging ,Tumor progression ,030220 oncology & carcinogenesis ,Hepatocellular carcinoma ,Disease Progression ,Medicine ,Female ,Cancer imaging ,Dose Fractionation, Radiation ,business ,Nuclear medicine ,Progressive disease - Abstract
The objectives of this study were to assess changes in apparent diffusion coefficient (ADC) and dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) parameters after radiation therapy (RT) for bone metastases from hepatocellular carcinoma (HCC) and to evaluate their prognostic value. This prospective study was approved by the Institutional Review Board. Fourteen patients with HCC underwent RT (30 Gy in 10 fractions once daily) for bone metastases. The ADC and DCE-MRI parameters and the volume of the target lesions were measured before (baseline) and one month after RT (post-RT). The Wilcoxon signed-rank test was used to compare the parameters between the baseline and post-RT MRI. The parameters were compared between patients with or without disease progression in RT fields using the Mann–Whitney test. Intraclass correlation coefficients were used to evaluate the interobserver agreement. The medians of the ADC, rate constant [kep], and volume fraction of the extravascular extracellular matrix [ve] in the baseline and post-RT MRI were 0.67 (range 0.61–0.72) and 0.75 (range 0.63–1.43) (× 10–3 mm2/s) (P = 0.027), 836.33 (range 301.41–1082.32) and 335.80 (range 21.86–741.87) (× 10–3/min) (P = 0.002), and 161.54 (range 128.38–410.13) and 273.99 (range 181.39–1216.95) (× 10–3) (P = 0.027), respectively. The medians of the percent change in the ADC of post-RT MRI in patients with progressive disease and patients without progressive disease were − 1.35 (range − 6.16 to 6.79) and + 46.71 (range 7.71–112.81) (%) (P = 0.011), respectively. The interobserver agreements for all MRI parameters were excellent (intraclass correlation coefficients > 0.8). In conclusion, the ADC, kep, and ve of bone metastases changed significantly after RT. The percentage change in the ADC was closely related to local tumor progression.
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- 2021
26. Stabilization of the Q-switching pulse energy of a composite YAG/Yb:YAG/Cr:YAG laser used as a laser ignitor
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Youngin Park, Jeonghyun Chang, Hyun Su Kim, and Seongsoo Kim
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010302 applied physics ,Materials science ,business.industry ,Physics::Optics ,General Physics and Astronomy ,02 engineering and technology ,021001 nanoscience & nanotechnology ,IGNITOR ,Laser ,01 natural sciences ,Q-switching ,Signal ,Noise (electronics) ,law.invention ,Resonator ,Interference (communication) ,Physics::Plasma Physics ,law ,0103 physical sciences ,Optoelectronics ,0210 nano-technology ,business ,Fabry–Pérot interferometer - Abstract
We propose a stabilization method for a Q-switched composite YAG/Yb:YAG/Cr:YAG laser configured for use as a laser igniter. The method is based on reducing the fluctuations in the magnitude of the initial seed signal caused by interference of the initial resonator modes. We have shown that a stable laser output could be achieved using a Fabry-Perot etalon, which can reduce the number of modes, to reduce the initial noise fluctuation in a resonator.
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- 2021
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27. Collective Syntheses of Guaiane Sesquiterpenes: Stereoselective Syntheses of (+)-Dysodensiol F, (+)-10β,14-Dihydroxy-allo-aromadendrane, and (−)-Dendroside C Aglycon
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Young-Ger Suh, Seungbeom Lee, Jaehoon Sim, Changjin Lim, Hyun Jin Choi, Hyunkyung Park, Juhee Lim, Tae Woo Kim, Joonseong Hur, and Hyun Su Kim
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Tsuji–Trost reaction ,Cyclopropanation ,Stereochemistry ,Chemistry ,Intramolecular force ,Organic Chemistry ,Total synthesis ,Stereoselectivity ,Key features ,Dieckmann condensation ,Conjugate - Abstract
A collective synthetic route for tricyclic guaiane sesquiterpenes and total syntheses of (+)-dysodensiol F, (+)-10β,14-dihydroxy-allo-aromadendrane, and (-)-dendroside C aglycon starting from a versatile hydroazulene intermediate were accomplished. The key features of these syntheses involve late-stage carbene-mediated diastereoselective cyclopropanation, construction of an unusual cis-fused-hydroazulene skeleton via intramolecular Dieckmann condensation, and highly stereoselective tandem conjugate addition/intramolecular allylic alkylation to afford a 5/7/3 tricyclic skeleton of guaiane natural products. The synthesis of (-)-dendroside C aglycon and the first total synthesis of (+)-dysodensiol F and (+)-10β,14-dihydroxy-allo-aromadendrane are described in detail. Activation of the Nrf2/ARE signaling pathway by (-)-dendroside C aglycon is also disclosed via our synthesis.
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- 2020
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28. Hepatoprotective Effects ofStreptococcus thermophilusLM1012 in Mice Exposed to Air Pollutants
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Ji Yeon Lee, Donghyuck Bae, Chulyung Choi, Yong Pil Hwang, Wilhelm H. Holzapfel, Tae-Rahk Kim, Hyun-Su Kim, Yosep Ji, and Min-Gyu Jeon
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Streptococcus thermophilus ,Nutrition and Dietetics ,biology ,Medicine (miscellaneous) ,Interleukin ,Pharmacology ,biology.organism_classification ,medicine.disease_cause ,Proinflammatory cytokine ,chemistry.chemical_compound ,chemistry ,In vivo ,Lactate dehydrogenase ,medicine ,Viability assay ,Cytotoxicity ,Oxidative stress - Abstract
In this study, we explored whether the use of Streptococcus thermophilus LM1012 (TL-LM1012) as a safe probiotic exerts hepatoprotective effects by suppressing oxidative stress and inflammation in vitro and alleviating aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH) production in vivo. In a series of safety tests, TL-LM1012 was found to have a negative response to hemolysis and biogenic amines, as well as susceptibility to antibiotics. TL-LM1012 protected cell viability and suppressed cytotoxicity by inhibiting oxidative stress and induced heme oxygenase-1 and superoxide dismutase activity in a dose-dependent manner in diesel exhaust particulate matter (DEPM)-treated HepG2 cells. Moreover, proinflammatory cytokines, including tumor necrosis factor-α, interleukin (IL)-6, and IL-1β, were suppressed in DEPM-treated splenocytes. In DEPM-treated mice, oral administration of TL-LM1012 regulated AST, ALT, and LDH production in the serum after 14 days of treatment. These findings indicate that TL-LM1012, a safe probiotic, provides a potent preventive or therapeutic effect against liver disease caused by air pollution.
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- 2020
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29. The Effects of Child Care Teachers’ Positive Psychological Capital and Organizational Commitment on Teacher-Child Interaction
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Hyun-Su Kim, Sunghee Lee, and Young-Sun Choi
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Child care ,Organizational commitment ,Positive psychological capital ,Psychology ,Social psychology - Published
- 2020
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30. Introduction: Topics in Musical Interpretation
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Sezi Seskir and David Hyun-su Kim
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History ,Feature (computer vision) ,Musical education ,Interpretation (philosophy) ,Musical ,Schism ,Music ,Linguistics - Abstract
A telling feature of modern musical education is the well-established schism between theory and practice. This dichotomy is most directly observed in the two currently prevailing institutions for m...
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- 2020
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31. Nusinersen Administration in Spinal Muscular Atrophy Patients with Severe Scoliosis: Interlaminar Approaches at the Lumbar Level
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Se-Jun Park, Jeehun Lee, Hyun Su Kim, Joo Young Song, and Ji Won Lee
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scoliosis ,lcsh:Internal medicine ,business.industry ,nusinersen ,injections, spinal ,Spinal muscular atrophy ,Scoliosis ,SMA ,medicine.disease ,lcsh:RC346-429 ,fluoroscopy ,lcsh:RC321-571 ,Severe scoliosis ,Lumbar ,Neurology ,Anesthesia ,Pediatrics, Perinatology and Child Health ,medicine ,Nusinersen ,Neurology (clinical) ,business ,lcsh:RC31-1245 ,lcsh:Neurosciences. Biological psychiatry. Neuropsychiatry ,muscular atrophy, spinal ,lcsh:Neurology. Diseases of the nervous system - Abstract
Purpose Spinal muscular atrophy (SMA) is a genetic progressive neuromuscular disorder, and nusinersen has shown to improve its symptoms. Scoliosis is a frequent symptom in patients with SMA and complicates the intrathecal injection of nusinersen. The aim of this study was to investigate the safety and effectiveness of fluoroscopy-guided intrathecal injections in patients with SMA with severe scoliosis. Methods We retrospectively reviewed the medical records of 11 patients with SMA treated with nusinersen intrathecal injections at the Samsung Medical Center from 2018 to 2020. We assessed the type of SMA, genetic results, spine computed tomography or fluoroscopy findings, and adverse effects associated with the injection. Results Of 11 patients with SMA, six were diagnosed with severe scoliosis, four of whom underwent an operation for scoliosis. The six patients with severe scoliosis started receiving the nusinersen injection at a median age of 15.7 years. A total of 25 injections were completely performed with the interlaminar approach (ILA) at the lumbar level under C-arm fluoroscopy guidance. No adverse effects other than mild headache occurred. In one patient who underwent the complete fusion operation for scoliosis, laminectomy was performed for the nusinersen injection, and 3 doses were administered intrathecally via the interlaminar route at the lumbar level. Conclusion Fluoroscopy-guided ILA is a safe method for the intrathecal injection of nusinersen in patients with SMA with severe scoliosis. When defining the route, laminectomy might be necessary to open the window for the ILA route at the lumbar level.
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- 2020
32. Obesity is associated with improved postoperative overall survival, independent of skeletal muscle mass in lung adenocarcinoma
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Ji Hyun Lee, Young Cheol Yoon, Hyun Su Kim, Min Jae Cha, Jae‐Hun Kim, Kyunga Kim, and Hye Seung Kim
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Male ,Sarcopenia ,Lung Neoplasms ,Physiology (medical) ,Humans ,Orthopedics and Sports Medicine ,Adenocarcinoma of Lung ,Female ,Obesity ,Middle Aged ,Muscle, Skeletal ,Aged ,Retrospective Studies - Abstract
Although the obesity paradox is a topic of immense interest for oncologists and epidemiologists, the mechanism underlying this unexpected benefit of obesity is poorly understood. We explored the prognostic value of obesity and its association with skeletal muscle mass.This retrospective study evaluated the data of patients who underwent surgical excision for lung adenocarcinoma between January 2011 and December 2015. Body mass index was categorized according to the criteria of the Asia-Pacific classification. Cross-sectional areas of the skeletal muscle, subcutaneous fat, and visceral fat were measured. Skeletal muscle mass status was defined based on the cut-offs of skeletal muscle index (cmA total of 636 patients with a median age of 61 years (interquartile range, 54.0-68.5 years; 321 men and 315 women) were included. Obese patients (body mass index ≥ 25 kg/mObesity was associated with favourable overall survival, independent of skeletal muscle mass, after surgical excision of lung adenocarcinoma.
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- 2022
33. Association Between Pelvic Bone Computed Tomography-Derived Body Composition and Patient Outcomes in Older Adults With Proximal Femur Fracture
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Tae Ran Ahn, Young Cheol Yoon, Hyun Su Kim, Kyunga Kim, and Ji Hyun Lee
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Radiology, Nuclear Medicine and imaging - Published
- 2023
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34. Xanthohumol Interferes with the Activation of TGF-β Signaling in the Process Leading to Intestinal Fibrosis
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Sun-Mi Yun, Young-Min Han, Moon-Young Song, Da-Young Lee, Hyun Su Kim, Seok-Ho Kim, and Eun-Hee Kim
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Nutrition and Dietetics ,Xanthohumol ,intestinal fibrosis ,TGF-β signaling ,NF-κB signaling ,α-SMA ,Food Science - Abstract
Fibrosis has various biological processes and affects almost every organ, especially in patients with inflammatory bowel disease, including Crohn’s disease, who experience discomfort caused by intestinal fibrosis, which is a problem that needs to be resolved. TGF-β signaling is known to act as a key regulator of intestinal fibrosis, and its modulation could be an excellent candidate for fibrosis therapy. Xanthohumol (XN) has various effects, including anti-inflammation and anti-cancer; however, the detailed mechanism of TGF-β signaling has not yet been studied. The purpose of this study was to investigate the mechanism underlying the anti-fibrotic effect of XN on TGF-β1-induced intestinal fibrosis using primary human intestinal fibroblasts (HIFs). In this study, to check the anti-fibrotic effects of XN on intestinal fibrosis, we assessed the expression of fibrosis-related genes in TGF-β1-stimulated HIFs by qPCR, immunoblotting, and immunofluorescence staining. As a result, XN showed the ability to reduce the expression of fibrosis-associated genes increased by TGF-β1 treatment in HIFs and restored the cell shape altered by TGF-β1. In particular, XN repressed both NF-κB- and Smad-binding regions in the α-SMA promoter, which is important in fibrosis. In addition, XN inhibited NF-κB signaling, including phosphorylated-IkBα and cyclooxygenase-2 expression, and TNF-α-stimulated transcriptional activity of NF-κB. XN attenuated TGF-β1-induced phosphorylation of Smad2 and Smad3, and the transcriptional activity of CAGA. Particularly, XN interfered with the binding of TGF-Receptor I (TβRI) and Smad3 by binding to the kinase domain of the L45 loop of TβRI, thereby confirming that the fibrosis mechanism did not proceed further. In conclusion, XN has an inhibitory effect on TGF-β1-induced intestinal fibrosis in HIFs, significantly affecting TGF-β/Smad signaling.
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- 2022
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35. Discovery of new ERRγ agonists regulating dopaminergic neuronal phenotype in SH-SY5Y cells
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Taewoo Kim, Hyo In Kim, Haejun Oh, Yoonsu Jeon, Hyeyoung Shin, Hyun Su Kim, Juhee Lim, Changjin Lim, Jakyung Yoo, Young-Ger Suh, Woo Sung Son, Hyun Jin Choi, and Seok-Ho Kim
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Molecular Docking Simulation ,Phenotype ,Receptors, Estrogen ,Dopaminergic Neurons ,Organic Chemistry ,Drug Discovery ,Molecular Biology ,Biochemistry ,Up-Regulation - Abstract
The discovery of small molecules that regulate specific neuronal phenotypes is important for the development of new therapeutic candidates for neurological diseases. Estrogen-related receptor γ (ERRγ), an orphan nuclear receptor widely expressed in the central nervous system (CNS), is closely related to the regulation of neuronal metabolism and differentiation. We previously reported that upregulation of ERRγ could enhance dopaminergic neuronal phenotypes in the neuroblastoma cell line, SH-SY5Y. In this study, we designed and synthesized a series of new ERRγ agonists using the X-ray crystal structure of the GSK4716-bound ERRγ complex and known synthetic ligands. Our new ERRγ agonists exhibited increased transcriptional activities of ERRγ. In addition, our molecular docking results supported the experimental findings for ERRγ agonistic activity of the potent analogue, 5d. Importantly, 5d not only enhanced the expression of dopaminergic neuronal-specific molecules, TH and DAT but also activated the relevant signaling events, such as the CREB-mediated signaling pathway. The results of the present study may provide useful clues for the development of novel ERRγ agonists for neurological diseases related to the dopaminergic nervous system.
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- 2021
36. Intraepineurial fat quantification and cross-sectional area analysis of the sciatic nerve using MRI in Charcot-Marie-Tooth disease type 1A patients
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Min Jae Cha, Hojeong Won, Ji Hyun Lee, Young Cheol Yoon, Hyun Su Kim, Seonwoo Kim, Byung-Ok Choi, Soo Hyun Nam, and Hye Mi Kwon
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Adult ,Male ,medicine.medical_specialty ,congenital, hereditary, and neonatal diseases and abnormalities ,Adolescent ,Science ,Urology ,Thigh ,Fat quantification ,Article ,Fats ,Young Adult ,Charcot-Marie-Tooth Disease ,medicine ,Humans ,Clinical severity ,Proton density ,Child ,Fat fraction ,Multidisciplinary ,Musculoskeletal system ,business.industry ,Charcot-Marie-Tooth Disease Type 1A ,Magnetic Resonance Imaging ,Sciatic Nerve ,Demyelinating diseases ,medicine.anatomical_structure ,Cross-Sectional Studies ,Neurology ,Case-Control Studies ,Child, Preschool ,Medicine ,Female ,Sciatic nerve ,business - Abstract
The objectives of this study were to assess the fat fraction (FF) and cross-sectional area (CSA) of the sciatic nerve in Charcot-Marie-Tooth disease type 1A (CMT1A) patients using Dixon-based proton density fat quantification MRI and to elucidate its potential association with clinical parameters. Thigh MRIs of 18 CMT1A patients and 18 age- and sex-matched volunteers enrolled for a previous study were reviewed. Analyses for FF and CSA of the sciatic nerve were performed at three levels (proximal to distal). CSA and FF were compared between the two groups and among the different levels within each group. The relationship between the MRI parameters and clinical data were assessed in the CMT1A patients. The CMT1A patients showed significantly higher FF at level 3 (p = 0.0217) and significantly larger CSA at all three levels compared with the control participants (p < 0.0001). Comparisons among levels showed significantly higher FF for levels 2 and 3 than for level 1 and significantly larger CSA for level 2 compared with level 1 in CMT1A patients. CSA at level 3 correlated positively with the CMT Neuropathy Score version 2 (CMTNSv2). In conclusion, the sciatic nerve FF of CMT1A patients was significantly higher on level 3 compared with both the controls and the measurements taken on more proximal levels, suggesting the possibility of increased intraepineurial fat within the sciatic nerves of CMT1A patients, with a possible distal tendency. Sciatic nerve CSA at level 3 correlated significantly and positively with CMTNSv2, suggesting its potential value as an imaging marker for clinical severity.
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- 2021
37. An Efficient Ionic Liquid-Mediated Extraction and Enrichment of Isoimperatorin from Ostericum koreanum (Max.) Kitagawa
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Kiwon Jung, Tae Kon Kim, Young-Ger Suh, Alice Nguvoko Kiyonga, Gyu Hwan Park, and Hyun Su Kim
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enrichment ,Central composite design ,crystallization ,Pharmaceutical Science ,Raw material ,Plant Roots ,Article ,Analytical Chemistry ,law.invention ,ionic liquids ,chemistry.chemical_compound ,QD241-441 ,law ,Furocoumarins ,Drug Discovery ,Physical and Theoretical Chemistry ,Ostericum koreanum ,Crystallization ,Chromatography ,Molecular Structure ,Organic Chemistry ,Extraction (chemistry) ,isoimperatorin ,chemistry ,Chemistry (miscellaneous) ,Yield (chemistry) ,Ionic liquid ,extraction ,Molecular Medicine ,Separation method ,Apiaceae - Abstract
Ionic liquids (ILs) have attracted significant interest because of their desirable properties. These characteristics have improved their application to overcome the shortcomings of conventional separation techniques for phytochemicals. In this study, several ILs were investigated for their capacity to extract isoimperatorin, a bioactive furanocoumarin, from the roots of Ostericum koreanum. Herein, 1-Butyl-3-methylimidazolium tetrafluoroborate ([Bmim][BF4]) was selected as a promising IL for separating isoimperatorin. A central composite design was applied to optimize the extraction conditions. Under the optimal conditions, the yield of isoimperatorin reached 97.17 ± 1.84%. Additionally, the recovery of isoimperatorin from the [Bmim][BF4] solution was successfully achieved (87.73 ± 2.37%) by crystallization using water as an antisolvent. The purity of the isoimperatorin was greatly enhanced, from 0.26 ± 0.28% in the raw material to 26.94 ± 1.26% in the product, in a one-step crystallization process. Namely, an enhancement of approximately 103-folds was reached. The developed approach overcomes the shortcomings of conventional separation methods applied for gaining isoimperatorin by significantly reducing the laboriousness of the process and the consumption of volatile organic solvents. Moreover, the simplicity and effectiveness of the method are assumed to be valuable for producing isoimperatorin-enriched products and for promoting its purification. This work also confirms the efficiency of ILs as a promising material for the separation of phytochemicals.
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- 2021
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38. Which Parameter Influences Local Disease-Free Survival after Radiation Therapy Due to Osteolytic Metastasis? A Retrospective Study with Pre- and Post-Radiation Therapy MRI including Diffusion-Weighted Images
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Jiyeong Lee, Young Cheol Yoon, Ji Hyun Lee, and Hyun Su Kim
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body regions ,local disease progression-free survival ,diffusion-weighted imaging ,Medicine ,apparent diffusion coefficient ,General Medicine ,histogram ,radiation therapy ,bone metastasis ,Article - Abstract
Although radiation therapy (RT) plays an important role in the palliation of localized bone metastases, there is no consensus on a reliable method for evaluating treatment response. Therefore, we retrospectively evaluated the potential of magnetic resonance imaging (MRI) using apparent diffusion coefficient (ADC) maps and conventional images in whole-tumor volumetric analysis of texture features for assessing treatment response after RT. For this purpose, 28 patients who received RT for osteolytic bone metastasis and underwent both pre- and post-RT MRI were enrolled. Volumetric ADC histograms and conventional parameters were compared. Cox regression analyses were used to determine whether the change ratio in these parameters was associated with local disease progression-free survival (LDPFS). The ADCmaximum, ADCmean, ADCmedian, ADCSD, maximum diameter, and volume of the target lesions after RT significantly increased. Change ratios of ADCmean < 1.41, tumor diameter ≥ 1.17, and tumor volume ≥ 1.55 were significant predictors of poor LDPFS. Whole-tumor volumetric ADC analysis might be utilized for monitoring patient response to RT and potentially useful in predicting clinical outcomes.
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- 2021
39. Resolution limit and photon flux dependency in EUV ptychography
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Yasin Ekinci, Hyun-Su Kim, Ricarda Nebling, Atoosa Dejkameh, Iacopo Mochi, and Tao Shen
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Diffraction ,Materials science ,Microscope ,business.industry ,Image quality ,Extreme ultraviolet lithography ,Detector ,Mask inspection ,Coherent diffraction imaging ,Ptychography ,law.invention ,Optics ,law ,business - Abstract
With the transition of EUV lithography to high volume manufacturing, EUV mask metrology has become a critical requirement. At PSI, we are developing RESCAN, a lensless actinic microscope dedicated to EUV mask inspection. RESCAN is based on coherent diffraction imaging (CDI), a method that reconstructs the complex image of the sample through its diffraction spectrum measured with a CCD detector. While this approach can overcome the cons and limitations of traditional optical imaging systems, in CDI, the quality of the recorded diffraction data is crucial for the reliable reconstruction of a high-resolution image. Ultimately, the signal-to-noise ratio of the recorded diffraction data depends on several parameters, such as the reflectance of the sample, the quantum efficiency of the detector, its full well capacity, and the intensity of the illumination. This paper investigates the optimal photon flux for RESCAN and analyzes the relation between the image quality and the EUV illumination intensity for a CDI-based imaging tool dedicated to EUV mask inspection and review.
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- 2021
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40. The Contribution of Ecosystem Regulating Services Based on Their Interrelationship in the Urban Ecosystem
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Kyushik Oh, Dongwoo Lee, and Hyun-Su Kim
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Technology ,QH301-705.5 ,QC1-999 ,Population ,Land cover ,ecosystem regulating services ,Ecosystem services ,contribution ,Agricultural land ,General Materials Science ,Ecosystem ,interrelationship ,Biology (General) ,education ,Instrumentation ,QD1-999 ,Fluid Flow and Transfer Processes ,Service (business) ,education.field_of_study ,Land use ,business.industry ,Process Chemistry and Technology ,Physics ,Environmental resource management ,General Engineering ,technology, industry, and agriculture ,ecosystem services balance ,Engineering (General). Civil engineering (General) ,Computer Science Applications ,ecosystem services assessment ,Chemistry ,Geography ,pairwise comparison ,Urban ecosystem ,TA1-2040 ,business - Abstract
The urban ecosystem provides many services that help humans lead physically and mentally healthy lives. The quality of such urban ecosystem services is closely related to various urban forms, such as land cover, land use, buildings, infrastructure, population, and type and scale of green space. This study aims to promote the overall improvement and balance of an urban ecosystem’s regulating services. Initially, ecosystem regulating services are assessed according to the type of the urban space, and their contributions are analyzed based on linear regression slope and pairwise comparison of the ecosystem services. The contribution of ecosystem regulating services of Suwon City in South Korea was assessed through the following process: (1) selection of assessment indices and assessment methods for urban ecosystem regulating services, (2) urban space classification, (3) ecosystem regulating service assessment by type of urban space, and (4) pairwise comparison of ecosystem regulating services by type and for the entire study area. The study areas are classified into six type areas: forests (type A), agricultural land (type B), low-rise residential areas (type C), mid-rise mixed (residential and commercial) areas (type D), high-rise residential areas (type E), and industrial and barren land (type F). By studying representative regulating services, such as vegetation vitality, flood reduction capacity, carbon storage capacity, and heat reduction capacity, this study confirmed that type A provided the best service, while type C provided the worst. In addition, the relative contribution analysis between the regulating services based on pairwise comparison showed that the standard deviation between the contributions was 0.04 when diagnosing the entire study area, but apparently no types except type A were balanced. The reason such regulating services are imbalanced is that their vegetation vitality was calculated to be the lowest compared with the assessment indices of type A. Additionally, this imbalance was found to be most severe in the mid-rise mixed (residential and commercial) districts. Through this study, the spatial types in which the ecosystem regulating services in Suwon City are imbalanced could be determined. It was also revealed that regulating services should be prioritized for improvement in order to achieve greater balance in urban ecosystem. Such pairwise comparison results can be effectively utilized in determining the area and supply needed when formulating urban greening plans and forest restoration plans.
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- 2021
41. A priori information in ptychographic image reconstruction for EUV mask metrology
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Tao Shen, Ricarda Nebling, Yasin Ekinci, Hyun-Su Kim, Iacopo Mochi, and Atoosa Dejkameh
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Signal-to-noise ratio ,Extreme ultraviolet lithography ,Shot noise ,Iterative reconstruction ,Photomask ,Phase retrieval ,Algorithm ,Ptychography ,Metrology - Abstract
EUV photomasks define the lithographic layers of chips, which are binary structures of relatively low versatility in contrast to specimen in biology or materials science. This knowledge can be used in EUV photomask imaging and inspection methods to improve the speed or sensitivity. We present here a total variation-based phase retrieval algorithm similar to previous methods by Chang et al. and Enfedaque et al. for EUV mask imaging and metrology. Total variation (TV) regularization exploits the binary structure of the reticles, enforcing a sparse sample gradient. We compare the TV regularized algorithm, PtychoADMM, to a standard phase retrieval approach, the difference map (DM). For simulated data containing Poisson noise, we do not observe a benefit from using the TV based PtychoADMM algorithm. The reconstructed image quality is similar, while PtychoADMM being a computationally more demanding method. In future, we will investigate if TV can recover information where the standard DM approach fails, e.g. for relaxed measurement requirements like a lower signal to noise ratio or less probe overlap in the ptychography scan.
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- 2021
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42. Medical Humanities in Edmund D. Pellegrino
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Hyun-su Kim
- Subjects
Philosophy of medicine ,Modeling and Simulation ,Philosophy ,Medical humanities ,Bioethics ,Classics - Published
- 2020
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43. Spatiotemporal Distribution of Algae and Characteristics of Algal Abundance in Lake Okjung, Korea
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Ye-eun Moon and Hyun-su Kim
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Algae ,biology ,Abundance (ecology) ,business.industry ,Ecology ,Environmental science ,Distribution (economics) ,biology.organism_classification ,business - Published
- 2019
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44. Micronized, Heat-Treated Lactobacillus plantarum LM1004 Alleviates Cyclophosphamide-Induced Immune Suppression
- Author
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Jeon Min Gyu, Ye Jin Jung, Hyun-Su Kim, Chulyung Choi, Da Som Oh, Yong Pil Hwang, Yu-Jin Kim, Gyeong-Eun Lee, Jung Il Seon, and Donghyuck Bae
- Subjects
0301 basic medicine ,030109 nutrition & dietetics ,Nutrition and Dietetics ,Chemistry ,medicine.medical_treatment ,Medicine (miscellaneous) ,Interleukin ,Spleen ,Immunosuppression ,Pharmacology ,03 medical and health sciences ,0302 clinical medicine ,medicine.anatomical_structure ,Immune system ,Cytokine ,Interferon ,030220 oncology & carcinogenesis ,medicine ,Splenocyte ,Tumor necrosis factor alpha ,medicine.drug - Abstract
The present study investigated the immunomodulatory activity and associated mechanisms of heat-treated Lactobacillus plantarum LM1004 (HT-LM1004) in a cyclophosphamide (CTX)-induced mouse model of immunosuppression. HT-LM1004 induced phagocytic activity and nitric oxide production in RAW264.7 macrophages and stimulated the release of tumor necrosis factor (TNF)-α, interferon (IFN)-γ, interleukin (IL)-2, and IL-12p70. In mice with CTX-induced immunosuppression, oral HT-LM1004 administration restored thymus and spleen indices, including spleen weight. Consistent with the in vitro results, HT-LM1004 increased TNF-α, IFN-γ, IL-2, and IL-12p70 levels in mice after 14 days of treatment and enhanced the natural killer (NK) cell activity of splenocytes from mice with CTX-induced immunosuppression against YAC-1 lymphoma cells. The method of HT-LM1004 generation influenced this activity: L. plantarum LM1004 grown in a membrane bioreactor, which reduced the size of the cells to
- Published
- 2019
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45. Passive, Ultrashort Pulse, Coherent Beam Combination Using a Polarization Michelson Interferometer Geometry and Two-pass Amplifier
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Jun Young Seong, Young Hun Cho, and Hyun Su Kim
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010302 applied physics ,Physics ,Optical autocorrelation ,business.industry ,Amplifier ,General Physics and Astronomy ,Signal Width ,Michelson interferometer ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Polarization (waves) ,01 natural sciences ,law.invention ,Optics ,law ,Fiber laser ,0103 physical sciences ,Physics::Accelerator Physics ,0210 nano-technology ,business ,Ultrashort pulse ,Beam (structure) - Abstract
We propose a passively coherent combined polarization beam system composed of a polarization Michelson interferometer and a two-pass amplifier. We investigate the output characteristics, such as the output power, spectrum, and intensity autocorrelation signal of the two-pulse combined beam, and compare the results with one of the two divided pulses utilized for the beam combination. We found that the intensity autocorrelation signal width difference between the two compared beams was less than 1%.
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- 2019
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46. Muscle fat quantification using magnetic resonance imaging: case–control study of Charcot–Marie–Tooth disease patients and volunteers
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Young Cheol Yoon, Byung-Ok Choi, Jang Gyu Cha, Wook Jin, and Hyun Su Kim
- Subjects
0301 basic medicine ,Adult ,Male ,lcsh:Diseases of the musculoskeletal system ,Intraclass correlation ,Thigh ,Charcot–Marie–Tooth disease ,lcsh:QM1-695 ,03 medical and health sciences ,Young Adult ,0302 clinical medicine ,Imaging, Three-Dimensional ,Magnetic resonance imaging ,Region of interest ,Charcot-Marie-Tooth Disease ,Physiology (medical) ,Muscle fat ,Medicine ,Humans ,Orthopedics and Sports Medicine ,Prospective Studies ,Muscle, Skeletal ,Reproducibility ,medicine.diagnostic_test ,business.industry ,Case-control study ,Multiple gradient echo Dixon ,Reproducibility of Results ,Original Articles ,lcsh:Human anatomy ,Healthy Volunteers ,Muscle fat quantification ,030104 developmental biology ,medicine.anatomical_structure ,Adipose Tissue ,030220 oncology & carcinogenesis ,Case-Control Studies ,Original Article ,Female ,Intramuscular fat ,lcsh:RC925-935 ,business ,Nuclear medicine - Abstract
Background This study aimed to evaluate the potential value of 3D multiple gradient echo Dixon‐based magnetic resonance imaging (MRI) sequence as a tool for thigh intramuscular fat quantification in Charcot–Marie–Tooth disease (CMT) patients. Methods A prospective comparison study comprising 18 CMT patients and 18 age/sex‐matched volunteers was performed. MRI including 3D multiple gradient echo Dixon‐based imaging was performed for each subject. Region of interest analyses were performed at the upper and lower third of both thighs. The two‐sample t‐test or Wilcoxon rank sum test was used for intergroup comparison of the mean muscle fat fraction. Intraclass correlation coefficients were used to evaluate the interobserver agreement and test–retest reproducibility. Semiquantitive analysis using the Goutallier classification (Grades 0–4) was performed on T1‐weighted images in upper thigh muscles. For Goutallier Grade 0 muscles, comparison of the mean intramuscular fat fraction between volunteers and CMT patients was performed. Results The interobserver agreements were excellent for all measurements (intraclass correlation coefficients > 0.8). Mean muscle fat fractions were significantly higher in all the measured muscles of CMT patients (P
- Published
- 2019
47. Inter-Annual and Seasonal Variations of Water Quality and Trophic Status of a Reservoir with Fluctuating Monsoon Precipitation
- Author
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Ye-eun Moon and Hyun-su Kim
- Subjects
reservoir ,Nitrogen ,Health, Toxicology and Mutagenesis ,Atmospheric sciences ,Monsoon ,Article ,Nutrient ,nutrients ,Water Quality ,Organic matter ,Trophic state index ,Precipitation ,Drainage ,trophic state index ,drainage ratio ,Trophic level ,organic matter ,chemistry.chemical_classification ,Public Health, Environmental and Occupational Health ,Phosphorus ,Eutrophication ,chemistry ,Medicine ,Environmental science ,Water quality ,Seasons ,Environmental Monitoring - Abstract
Long-term evaluation from 2000 to 2020 of a temperate reservoir indicated that water quality and trophic status were not critically controlled by the inter-annual dynamics of monsoon precipitation. The fluctuation of annual concentrations of TP, TSS, and EC did not always correlate with the variation of precipitation. BOD and COD demonstrated monotonically increasing trends with Sen’s slope of 0.02 and 0.01, respectively, while Chl-a manifested a decreasing trend (slope = −0.23). The increases of different magnitudes in the levels of TP, TSS, and Chl-a in the monsoon and the early post-monsoon periods were observed in the drought, flood, and normal years. The drought years showed distinct seasonal variations in many parameters, while those in the flood and the normal years were very similar. Pearson correlation and empirical regression analyses resulted in weaker correlation between water quality and hydrological parameters than other reservoirs, which, along with low impact of precipitation, was attributed to the low drainage ratio (28.8) of the study area. BOD/COD ratios were higher than 0.5 in the reservoir, indicating the presence of a significant fraction of biodegradable organic matter. The ratio increased in the longitudinal flow direction (>, 50% in the drought years), implying the possibility of autochthonous sources of organic matter. TSID evaluation resulted in variation of limiting factors not related to the fluctuation of annual precipitation. The loadings of the significant principal components were very similar among the different precipitation groups, supporting the other findings that annual precipitation governed by monsoon intensity would not solely control the water quality dynamics of the study area.
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- 2021
48. Assessment of Trophic Responses of a Reservoir to Seasonal and Annual Variations in Monsoon
- Author
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Su-mi Kim and Hyun-su Kim
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reservoir ,010504 meteorology & atmospheric sciences ,Geography, Planning and Development ,Population ,010501 environmental sciences ,Aquatic Science ,Atmospheric sciences ,Monsoon ,01 natural sciences ,Biochemistry ,trophic state ,Nutrient ,nutrients ,Phytoplankton ,monsoon ,Trophic state index ,Precipitation ,education ,TD201-500 ,0105 earth and related environmental sciences ,Water Science and Technology ,Trophic level ,education.field_of_study ,Water supply for domestic and industrial purposes ,Hydraulic engineering ,phytoplankton ,Environmental science ,Eutrophication ,TC1-978 - Abstract
The variations in water quality parameters and trophic status of a multipurpose reservoir in response to changing intensity of monsoon rain was investigated by applying a trophic state index deviation (TSID) analysis and an empirical regression model to the data collected in two periods from 2014 to 2017. The reservoir in general maintained mesotrophic conditions, and Carlson’s trophic state index (TSIc) was affected most by TSITP. Nutrient concentrations, particularly phosphorus, did not show strong correlations with precipitation, particularly in the period with weak monsoon, and a significant increase in total phosphorus (TP) was observed in Spring 2015, indicating the possibility of internal phosphorus loading under decreased depth and stability of water body due to a lack of precipitation. TSIChl was higher than TSISD in most data in period 1 when a negligible increase in precipitation was observed in the monsoon season while a significant fraction in period 2 showed the opposite trend. Phytoplankton growth was not limited by nutrient limitation although nutrient ratios (N/P) of most samples were significantly higher than 20, indicating phosphorus-limited condition. TSID and regression analysis indicated that phytoplankton growth was limited by zooplankton grazing in the Spring, and that cell concentrations and community structure in the monsoon and post-monsoon season were controlled by the changing intensity of the monsoon, as evidenced by the positive and negative relationships between community size and cyanobacterial population with the amount of precipitation in the Summer, respectively. The possibility of contribution from internal loading and an increase in cyanobacterial population associated with weak monsoon, in addition to potential for nutrient enrichment in the post-monsoon season, implies a need for the application of more stringent water quality management in the reservoir that can handle all potential scenarios of eutrophication.
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- 2021
49. Concise syntheses and anti-inflammatory effects of isocorniculatolide B and corniculatolide B and C
- Author
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Hyun Su Kim, Joonseong Hur, Dongyun Shin, Dong-Jun Kim, Da-Young Lee, Yoonsu Jeon, Hyuk Bang Kwon, Eun-Hee Kim, Seok-Ho Kim, Hyeyoung Shin, Changjin Lim, and Tae Woo Kim
- Subjects
Stereochemistry ,IκB kinase ,Biochemistry ,Cell Line ,chemistry.chemical_compound ,Lactones ,Structure-Activity Relationship ,Nucleophilic aromatic substitution ,Drug Discovery ,Animals ,Molecular Biology ,Dose-Response Relationship, Drug ,Molecular Structure ,Organic Chemistry ,Anti-Inflammatory Agents, Non-Steroidal ,NF-kappa B ,Total synthesis ,NF-κB ,Epithelial Cells ,Desmethyl ,Rats ,Claisen rearrangement ,chemistry ,Phosphorylation ,Macrolides ,Signal transduction - Abstract
The first total syntheses of isocorniculatolide B, corniculatolide B, and corniculatolide C, consisting of isomeric corniculatolide skeletons, have been accomplished in a divergent manner. The key features of the synthesis involve the construction of diaryl ether linkages by nucleophilic aromatic substitution, installation of a C14-substituted alkyl side chain via a sequence of Baeyer-Villiger reaction and Claisen rearrangement, and efficient construction of corniculatolide and isocorniculatolide frameworks, including 17-membered (exterior) macrolactone skeletons from a versatile diaryl ether intermediate by Mitsunobu macrolactonization. Moreover, we prepared the structural congeners of isomeric corniculatolides via diverted total synthesis approach including desmethyl analogues and related dimeric macrolides. The anti-inflammatory activities of the synthesized natural products, analogues and synthetic intermediates were also investigated. In particular, corniculatolide B significantly inhibited the protein expression of COX-2 and the mRNA expressions of TNF-α, IL-1β and IL-6 by inhibiting of NF-κB signaling in intestinal epithelial cells induced by lipopolysaccharide treatment. It also significantly inhibited the promoter activity and the phosphorylation of subunits p50 and p65 of NF-κB to the same extent as Bay 11-7082, a potent IκB kinase inhibitor. These results suggest that corniculatolide B might have therapeutic potential in inflammatory bowel disease via NF-κB signaling pathway.
- Published
- 2021
50. Si–OH Nest and Al Distribution of Silicalite-1 Core/Al-ZSM-5 Shell Zeolites for Methane Dehydroaromatization Reaction
- Author
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Hyun Su Kim, Haoxiang Zhang, Su Kyung Kang, Do-Young Hong, Pyung Soo Lee, and Elsa Tsegay Tikue
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Al-ZSM-5 ,Period (periodic table) ,General Chemical Engineering ,Shell (structure) ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Methane ,Catalysis ,Inorganic Chemistry ,chemistry.chemical_compound ,silicalite-1 ,General Materials Science ,zeolite ,Zeolite ,acid distribution ,Crystallography ,Coke ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,0104 chemical sciences ,core-shell ,chemistry ,Chemical engineering ,QD901-999 ,ZSM-5 ,0210 nano-technology ,Layer (electronics) - Abstract
Silicalite-1 core/Al-ZSM-5 shell zeolite crystals were prepared in various sizes for use as catalysts in methane dehydroaromatization (MDA), and the growth kinetics and corresponding physicochemical properties of this core–shell zeolite were investigated. Al-ZSM-5 was grown on silicalite-1 seeds at various Si/Al ratios. Core–shell catalysts of all size variations exhibited similar deactivation trends in the MDA reaction, with minor changes in aromatic yields despite clear differences in reaction channel lengths and acid-site properties. This outcome was shown to originate from the unique growth kinetics of the Al-ZSM-5 layer on silicalite-1 seeds, in which the Al species in the sol used in the synthesis were consumed quickly during the early aggregative growth period. This led to an interesting spatial distribution of Al in the Al-ZSM-5 layer, in that the inner layer was relatively Al-rich. This distribution is advantageous because it can inhibit coke deactivation, which often occurs at the catalyst surface during MDA. However, a substantial quantity of Si–OH nests, which inhibit the effective loading of Mo species at the acid sites of the crystals, were detected in the microstructural analysis of large crystals. Therefore, this study shows that silicalite-1 core/Al-ZSM-5 shell zeolites can be prepared for use as coke-resistant catalysts for the MDA reaction. Further work is required, however, to design a synthesis method which reduces the number of Si–OH nests formed.
- Published
- 2021
- Full Text
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