Arthroscopic Treatment of Elbow Osteoarthritis and Arthroscopic Ulnar Nerve Decompression

Seok Won Chung 대한견주관절의학회 2016 대한견주관절의학회지 Vol.19 No.4

Although arthroscopic surgery has been used conventionally, it has not been widely adopted yet due to the risks of complications, including nerve damage, technical difficulties, and limited indications. As shown in other joints, however, the use of an arthroscope will gradually increased in the elbow joint (‘Arthroscopy always wins’). Herein, arthroscopic treatments and arthroscopic ulnar nerve decompression will be discussed in cases of elbow osteoarthritis.

Superconducting MgB2 Wire Drawing Considering Anisotropic Hardening Behavior and Hydrostatic Effect

Young‑Seok Oh,Ho Won Lee,Kook‑Chae Chung,Duck‑Young Hwang,Seong‑Hoon Kang,Jeong Whan Yoon 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.7

Numerical modeling was conducted to investigate the deformation behavior of powder mixture during multi-pass drawingprocesses for multi-filamentary MgB2wire. A modified Drucker-Prager Cap (DPC) model with an elliptical cap surface usingthe new material characterization method was developed to capture the anisotropic hardening behavior and hydrostatic effectof the powder mixture. A number of uniaxial die compaction, cold isostatic pressing, diametrical compression, and uniaxialcompression tests were conducted using different powder densities to characterize the modified DPC model. A commercialfinite element software ABAQUS with a user subroutine was used to simulate the drawing of the MgB2wire. The densityand area fraction of the powder mixture during the wire-drawing process were verified with experimental results. The differencein packing density at the inner and outer filaments of the MgB2wire was successfully captured by simulation. Inaddition, the effect of the initial packing density on the superconducting properties of MgB2wire was numerically studied. It is shown that the increase in the superconducting area, which results from a high initial packing density, should be moreeffective compared to the increase in the grain connectivity in enhancing the critical current properties for the MgB2wirewhen the final packing density is saturated after a number of drawing processes.

Cystic Medullary Thyroid Carcinoma: A Case of Undergoing Endoscopic Thyroid Lobectomy

Dong Hae Chung,Jae Yeon Seok,Yoo Seung Chung1,Eun Mee Oh1,Jung Won Ryu1,Young Don Lee1 대한갑상선-내분비외과학회 2015 The Koreran journal of Endocrine Surgery Vol.15 No.1

On ultrasonography, medullary thyroid carcinoma (MTC) shows hypoechogenicity, an irregular margin, a predominantly solid composition, and microcalcifications, similar to those observed in papillary thyroid carcinoma (PTC). MTC presenting as a cystic lesion is rare, and endoscopic thyroidectomy can be performed for benign thyroid masses and early stage PTC, however it is inappropriate for MTC regardless of cystic change. The authors report a case of cystic MTC found after endoscopic thyroid lobectomy and provide a review of the literature on this topic.

산업장 근로자의 스트레스에 대한 한의계 연구경향

차윤엽 ( Yun Yeop Cha ),고연석 ( Youn Seok Ko ),이정한 ( Jung Han Lee ),정원석 ( Won Suk Chung ),신병철 ( Byung Cheul Shin ),전찬용 ( Chan Yong Jeon ),고호연 ( Ho Yeon Go ),선승호 ( Seong Ho Sun ),장보형 ( Bo Hyoung Jang ),송윤경 한방재활의학과학회 2013 한방재활의학과학회지 Vol.23 No.2

Objectives : The purpose of this study is to explore the trends of Korean medical study on stress in the industrial worker. Methods : We received numbers of the studies about stress in the industrial worker from 6 Korean web databases, using key words such as ‘Industry AND Stress’, ‘Oriental medicine AND Stress’, ‘Worker AND Stress’, ‘Workplace AND Stress’. We received 12 research papers and they were analyzed and the journals, the authors, the contents of 3 classification of those research papers. Results : Among them, we had 6 reviews of Dept. of preventive medicine and Dept. of third medicine, college of Korean Medicine, Won-kwang University, and the rest of them were 6 reviews. We had 4 reviews of Korean Journal of Oriental Preventive Medical Society, 2 reviews of the Journal of Traditional Korean Medicine, 2 reviews of Journal of Oriental Neuropsychiatry and so on. According to the contents of reviews, we had 7 reviews of correlation of industrial worker and stress, 4 reviews of cause on the industrial worker’s stress and 1 case report. Conclusions : We reviewed the trends of Korean medical study on stress in the industrial worker. The stress in the industrial workers were related with the type of occupation, social psychology, drinking, smoking, the satisfaction of job, the harmony of organization.And we knew that the musculoskeletal pain was related to the industrial worker’s stress. In the future, abundant case studies, follow-up trials and RCTs should be done about the industrial worker’s stress.

우황청심원 관련 최근 연구 동향 : 국내 논문에 대한 고찰

이제원,백경민,백영두,임은영,장우석,전우현,정인권,Lee, Je-Won,Baek, Kyung-Min,Baek, Young-Doo,Im, Eun-Young,Chang, Woo-Seok,Cheon, Woo-Hyun,Chung, In-Kwon 대한한방내과학회 2010 大韓韓方內科學會誌 Vol.31 No.4

Objectives : Woohwangchungsim-won has been used for acute diseases such as cerebrovascular disease (stroke), heart disease. The aim of this study was to determine the effects, significance & necessity of Woohwangchungsim-won in acute stages of these disease by reviewing Korean articles about Woohwangchungsim-won. Methods : Article searches were performed on 8 major Korean web article search engine from January 1980 to August 2010. There were no restrictions on the types of publication, including grey articles. Results : Forty-three articles were included. Twenty one were efficacy tests, thirteen were comparative efficacy tests, eight were toxicity tests, and one was new method development. Eighteen articles were multicenter studies and twenty five were single center studies. Thirty two articles were animal testing, only ten articles were clinical articles. Thirty seven articles presented the composition and quantity of Woohwangchungsim-won, but six did not. Conclusions : The results of Korean articles about Woohwangchungsim-won can not strongly support the effects, significance & necessity of Woohwangchungsim-won. More rigorous studies are required for determination of the effects of Woohwangchungsim-won.

A Fuel Cell Generation System with a New Active Clamp Sepic-Flyback Converter

Won-Cheol Lee,Su-Jin Jang,Soo-Seok Kim,Su-Won Lee,Chung-Yuen Won 전력전자학회 2009 JOURNAL OF POWER ELECTRONICS Vol.9 No.1

A high efficiency active clamp sepic-flyback converter is presented for fuel cell generation systems. The proposed converter is a superposition of a sepic converter mode and flyback converter mode. The output voltages of the sepic converter mode and flyback converter mode can be regulated by the same PWM technique with constant frequency. By merging the sepic and flyback topologies, they can share the transformer, power MOSFET and active clamp circuit. The result has outstanding advantages over conventional active clamp DC-DC converters: high efficiency, high power density, and component utilization. Simulation results and experimental results are presented to verify the principles of operation for the proposed converter.

Characterization of Methylammonium Lead Iodide Perovskite Solar Cells by Surface Morphology Changes

Chung, Taewon,Kim, Seongtak,Bae, Soohyun,Lee, Sang-Won,Cho, Kyungjin,Lee, Seunghun,Kang, Yoonmook,Lee, Hae-Seok,Kim, Donghwan American Scientific Publishers 2017 Journal of Nanoscience and Nanotechnology Vol.17 No.7

<P>Organic-inorganic halide Perovskite solar cells have extremely high power conversion efficiencies of 22.1%, as officially recognized by the US National Renewable Energy Laboratory (NREL). These solar cells are therefore attractive candidates for use in next generation photovoltaic applications. Perovskite materials for incorporation into solar cells are prepared by a two-step solution fabrication process to generate polycrystalline structures with diverse grain sizes. PbI2 is the main material used in the synthesis of organic-inorganic hybrid perovskite, particularly when the sequential deposition method is employed, as it facilitates the formation of a well-organized perovskite layer. To improve the performance of these devices, the properties of PbI2 properties need to be investigated. We therefore examined the effects of PbI2 concentration in mesoporous perovskite solar cells prepared using a two-step solution deposition method. Samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), UV-Vis spectrometry, and atomic force microscopy (AFM). The results of this work confirm the importance of the PbI2 layer in high efficiency perovskite solar cells.</P>

25-Hydroxyvitamin D Status Is Associated With Chronic Cerebral Small Vessel Disease

Chung, Pil-Wook,Park, Kwang-Yeol,Kim, Jeong-Min,Shin, Dong-Woo,Park, Moo-Seok,Chung, Yun Jae,Ha, Sam-Yeol,Ahn, Suk-Won,Shin, Hae-Won,Kim, Yong Bum,Moon, Heui-Soo American Heart Association, Inc. 2015 Stroke Vol.46 No.1

<P><B>Background and Purpose—</B></P><P>The aim of this study was to determine the association between 25-hydroxyvitamin D (25(OH)D) and neuroimaging correlates of cerebral small vessel disease.</P><P><B>Methods—</B></P><P>We identified 759 consecutive patients with acute ischemic stroke or transient ischemic attack. Lacunes, white matter hyperintensity, and cerebral microbleed (CMB) were assessed using MR images. Deep CMB was defined as the presence of CMB in basal ganglia, thalamus, or brain stem. The association between 25(OH)D and small vessel disease was tested using linear and logistic regression analyses.</P><P><B>Results—</B></P><P>Mean age was 68 (±13) years. Mean level of 25(OH)D was 34.1±17.8 nmol/L. On bivariate analysis, a 25-nmol/L decrease in 25(OH)D was associated with lacunes (regression coefficient, 0.23; 95% confidence interval [CI], 0.02–0.45), severe white matter hyperintensity (odds ratio, 2.05; 95% CI, 1.41–3.08), and deep CMB (odds ratio, 1.28; 95% CI, 1.01–1.63). Also, 25(OH)D deficiency (≤25 nmol/L) was associated with lacunes (regression coefficient, 0.5; 95% CI, 0.04–0.95), severe white matter hyperintensity (odds ratio, 2.74; 95% CI, 1.31–6.45), and deep CMB (odds ratio, 1.68; 95% CI, 1.03–2.78). The association remained significant even after multivariable adjustment and in the subgroup of previously healthy patients.</P><P><B>Conclusions—</B></P><P>25(OH)D is inversely associated with lacunes, white matter hyperintensity, and deep CMB. Our findings suggest that 25(OH)D is linked to small vessel disease, and in future trials it should be tested whether 25(OH)D supplementation can prevent small vessel disease.</P>

The Adenylyl Cyclase Encoded by rutabaga Is Required for Larval Molting in Drosophila

Won Seok Son,Pyung Lim Han,Yun Doo Chung 한국유전학회 2008 Genes & Genomics Vol.30 No.2

Hormonal control of insect growth and metamorphosis by neuroendocrine system is well established, yet the cellular mechanism underlying the synthesis and release of insect hormones is not clearly understood. Here we report that a novel enhancer detection line, rutlethal-1096, failed to molt from second to third instar larvae, thus showing a lethal phenotype. Molecular cloning indicated that the enhancer detector was inserted in the proximal promoter region of the rut-encoded adenylyl cyclase (AC) gene. Similarly, the known rut alleles, rut1 and rut1084, were also found to be affected mildly in their larval and pupal development. The enriched expression of the reporter gene lacZ was detected in the ring gland that is an insect larval glandular organ secreting various hormones involved in ecdysis. Taken together, our data suggest the rut-encoded AC plays a vital role in larval molting, probably by regulating the function of ring glands.

Recurrence of Equinus Foot Deformity After Tendo-Achilles Lengthening in Patients With Cerebral Palsy

Chung, Chin Youb,Sung, Ki Hyuk,Lee, Kyoung Min,Lee, Seung Yeol,Choi, In Ho,Cho, Tae-Joon,Yoo, Won Joon,Park, Moon Seok Wolters Kluwer Health, Inc. All rights reserved. 2015 Journal of pediatric orthopedics Vol.35 No.4

BACKGROUND:: Recurrence of equinus deformity after surgery is common in patients with cerebral palsy. This retrospective study was undertaken to estimate the recurrence rate of the equinus deformity after tendo-Achilles lengthening (TAL) in patients with cerebral palsy and to investigate the risk factors associated with the recurrence. METHODS:: Two-hundred forty three ambulatory patients with cerebral palsy, who underwent TAL for equinus foot deformity since 1995, and had undergone a preoperative and postoperative 3-dimensional gait analysis, were included. Cox proportional hazards model was used to determine the significant contributing factor for the recurrence of equinus foot deformity. RESULTS:: The mean patient age at surgery was 7.8±2.7 years and the mean follow-up duration was 8.1±3.4 years. Equinus deformity recurred in 22 of the 243 patients (9.1%) and the Kaplan-Meier survival estimate was shown to be 89.4% at 10 years not needing repeat surgery. According to the multivariate analysis using the Cox proportional hazard model, preoperative ankle dorsiflexion at initial contact (P=0.016) was the only significant factor for recurrence of equinus deformity after surgery. Age at surgery and the type of limb involvement were not associated with the recurrence (P=0.433 and 0.269). The cutoff values of preoperative gait kinematics between the nonrecurrence and recurrence groups were −19 degrees of ankle dorsiflexion at initial contact (P=0.018). CONCLUSIONS:: This study showed that the severity of preoperative equinus deformity was a risk factor associated with recurrence after TAL in patients with cerebral palsy. Therefore, surgeons should consider the recurrence and later revision surgery for the patients with severe equinus foot deformity. LEVEL OF EVIDENCE:: Therapeutic level III.