<i>In-Situ</i> Catalytic Pyrolysis of Waste Lignin Over Desilicated Beta

Jung, Jung Sul,Kim, Young-Min,Han, Tae Uk,Lee, In-Gu,Rhee, Gwang Hoon,Jung, Sang-Chul,Kim, Sang Chai,Park, Young-Kwon American Scientific Publishers 2019 Journal of Nanoscience and Nanotechnology Vol.19 No.2

Metal-agglomeration-suppressed growth of MoS₂ and MoSe₂ films with small sulfur and selenium molecules for high mobility field effect transistor applications

Jung, Kwang Hoon,Yun, Sun Jin,Choi, Yongsuk,Cho, Jeong Ho,Lim, Jung Wook,Chai, Hyun-Jun,Cho, Dae-Hyung,Chung, Yong-Duck,Kim, Gayoung The Royal Society of Chemistry 2018 Nanoscale Vol.10 No.32

<P>This work reports a breakthrough technique for achieving high quality and uniform molybdenum dichalcogenide (MoX2 where X = S, Se) films on large-area wafers <I>via</I> metal-agglomeration-suppressed growth (MASG) with small chalcogen (X-) molecules at growth temperatures (<I>T</I>G) of 600 °C or lower. In order to grow MoS2 films suitable for field effect transistors (FETs), S-molecules should be pre-deposited on Mo films at 60 °C prior to heating the substrate up to <I>T</I>G. The pre-deposited S-molecules successfully suppressed the agglomeration of Mo during sulfurization and prevented the formation of protruding islands in the resultant sulfide films. The small X-molecules supplied from a thermal cracker reacted with Mo-precursor film to form MoX2. The film quality strongly depends on the temperatures of cracking and reservoir zones, as well as <I>T</I>G. The MoS2 film grown at 570 °C showed a thickness variation of less than 3.3% on a 6 inch-wafer. The mobility and on/off current ratio of 6.1 nm-MoS2 FET at <I>T</I>G = 570 °C were 59.8 cm<SUP>2</SUP> V<SUP>−1</SUP> s<SUP>−1</SUP> and 10<SUP>5</SUP>, respectively. The most significant advantages of the MASG method proposed in this work are its expandability to various metal dichalcogenides on larger substrates as well as a lower <I>T</I>G enabled by using reactive small molecules supplied from a cracker, for which temperature is independently controlled.</P>

Tensiomyography를 이용한 중추 피로에 의한 근육 손상의 평가

채정훈 ( Jung Hoon Chai ),배상원 ( Sang-won Bae ) 대한스포츠의학회 2020 대한스포츠의학회지 Vol.38 No.4

This study compared muscle function pre- and post-central fatigue caused by a marathon, using maximal displacement (Dm), which indicates muscular stiffness in tensiomyography (TMG) results. Blood and noninvasive TMG test were performed on the 1st, 3rd, and 5th days before and immediately after the marathon. The muscles assessed were the vastus lateralis (VL), vastus medialis (VM), rectus femoris (RF), biceps femoris (BF), semitendinosus (ST), tibialis anterior, gastrocnemius lateralis, and gastrocnemius medialis. Lactate dehydrogenase levels (lactate dehydrogenase) increased sharply immediately after the competition and decreased to the pre-competition level after 5 days. Dm was the highest immediately post-competition at BF, ST, VL, VM, and RF muscles, with a tendency to decrease to pre-competition levels after 1 day. The application of TMG to identify muscle changes in central fatigue studies may be appropriate in the proximal region rather than in the distal region.

Tensiomyography 측정 방법의 신뢰도 평가

채정훈 ( Jung-hoon Chai ),김보경 ( Bo-kyeong Kim ),최혁재 ( Hyuk-jae Choi ),배상원 ( Sang-won Bae ) 대한스포츠의학회 2018 대한스포츠의학회지 Vol.36 No.3

Purpose: This study is designed to evaluate the reliability for studies of tensiomyography (TMG). TMG can evaluate muscle function noninvasively and selectively. Methods: We measured 12 male volunteers (age, 26.5±7.6 years; height, 175.3±4.7 cm; weight, 78.8±13.3 kg) in this study and measured TMG during three occasions over 3 consecutive days. None of the participants has had any history of neuromuscular disorders or muscle diseases. Vastus lateralis, vastus medialis (VM), rectus femoris (RF) in quadriceps and biceps femoris, semitendinosus in hamstrings muscles were measured. Coefficient of variation (CV%) and intraclass correlation coefficient (ICC) have been calculated about maximal displacement (Dm, mm) and contraction time (Tc, ms) which are main parameters. Results: Most of the ICC of Dm were over 0.8 and the highest among the muscles except both VM. And, most ICC of Tc was lower than Dm except both BF (right, 18.31; left, 15.03). But, the ICC of Tc was lower than Dm except left RF (0.890) and VM (0.859). Conclusion: This study has shown that the Dm is high levels of the ICC and CV(%) in thigh muscle except VM. In the future, we plan to establish the method of measurement more clearly for reducing the errors of measurements. The technique of correct palpation of measurable muscles using TMG devices is also necessary.

Tensiomyography를 이용한 보디빌더 근육의 특성 분석

채정훈 ( Jung Hoon Chai ),김보경 ( Bo Kyeong Kim ),김찬 ( Chan Kim ),김철현 ( Chul Hyun Kim ),배상원 ( Sang Won Bae ) 대한스포츠의학회 2016 대한스포츠의학회지 Vol.34 No.2

The aim of this study is to evaluate the contractile properties of thigh muscles in bodybuilders through tensiomyography (TMG). Our hypothesis is that maximal displacement (Dm) in bodybuilders would be lower than in controls because Dm is increased when the muscle is stiffed or hypertrophied. Nine bodybuilder athletes and 15 university students were assessed by TMG. The biceps femoris (BF), semitendinosus (ST), vastus lateralis, vastus medialis (VM), and rectus femoris (RF) were evaluated. The TMG parameters obtained for each muscle were Dm, contraction time (Tc). And we calculated contraction velocity (Vc) as the rate of the radial displacement occurring during the time period of Tc with respect to Tc. Dm values of all muscles in bodybuilders were significantly higher compared to the control group. There were no significant differences in Tc values of most muscles except right BF and ST muscles. Vc values of VM, RF, and ST muscles were lower in bodybuilders than in the control group. This is the first report about TMG assessment of muscle hypertrophy. We found that Dm was most effective in detecting muscle hypertrophy and muscle stiffness secondary to muscle hypertrophy could induce decrease in Dm and Vc.

Regulation of Stem Cell Fate by ROS-mediated Alteration of Metabolism

Ryu, Jung Min,Lee, Hyun Jik,Jung, Young Hyun,Lee, Ki Hoon,Kim, Dah Ihm,Kim, Jeong Yeon,Ko, So Hee,Choi, Gee Euhn,Chai, Ing Ing,Song, Eun Ju,Oh, Ji Young,Lee, Sei-Jung,Han, Ho Jae Korean Society for Stem Cell Research 2015 International journal of stem cells Vol.8 No.1

<P>Stem cells have attracted much attention due to their distinct features that support infinite self-renewal and differentiation into the cellular derivatives of three lineages. Recent studies have suggested that many stem cells both embryonic and adult stem cells reside in a specialized niche defined by hypoxic condition. In this respect, distinguishing functional differences arising from the oxygen concentration is important in understanding the nature of stem cells and in controlling stem cell fate for therapeutic purposes. ROS act as cellular signaling molecules involved in the propagation of signaling and the translation of environmental cues into cellular responses to maintain cellular homeostasis, which is mediated by the coordination of various cellular processes, and to adapt cellular activity to available bioenergetic sources. Thus, in this review, we describe the physiological role of ROS in stem cell fate and its effect on the metabolic regulation of stem cells.</P>

XML 뷰 기반의 생물 정보원 통합 시스템 개발

정재훈 ( Jae-hoon Jung ),박은경 ( Eun-koung Park ),정채영 ( Chai-young Jung ),김현주 ( Hyun-ju Kim ),배종민 ( Jong-min Bae ) 한국정보처리학회 2005 한국정보처리학회 학술대회논문집 Vol.12 No.1

생물정보원은 이질성이 높고 사용자의 요구사항이 다양하다. 본 논문은 이러한 이질성을 해결하고 사용자의 다양한 요구사항에 쉽게 대처할 수 있는 XML 기반의 생물정보원 통합시스템의 설계개념과 구조 및 구현결과를 제시한다. 제시하는 통합시스템은 관계형테이블, 객체, XML, 플랫파일 등 다양한 자료형을 지원하면서, 관계형, 객체관계형, 자원, 응용프로그램 등 데이터 관리모델에 무관한 뷰 정의 및 질의처리모델이다. 그리고 사용자정의 XML 뷰 기반의 뷰 관리 및 질의처리를 통하여 사용자의 다양한 요구사항에 쉽게 적응할 수 있는 미디에이터 질의처리 기반의 생물정보원 통합시스템을 제시한다.

출력밀도 향상을 위한 매입형 영구자석 동기전동기의 회전자 형상 변화

정영훈(Young-Hoon Jung),채승희(Seung-Hee Chai),윤명환(Myung-Hwan Yoon),홍정표(Jung-Pyo Hong) 한국자동차공학회 2014 한국자동차공학회 부문종합 학술대회 Vol.2014 No.5

This paper presents power density improvement in accordance with rotor shape change. Prototype has design specifications which are 8 pole/48 slot, 143Nm. Prototype’s permanent magnet is buried with single layer in rotor. Proposed double layer model is changed in rotor shape for improvement of reluctance torque. Double layer model is characterized by buried double layer permanent magnet in rotor. Armature current is decreased in same torque by increase of reluctance torque. Stack length is decreased as much as a reduction ratio of armature current. Therefore, motor weight is come down and efficiency is increased as compared with prototype because of reduction of coil resistance.

고령의 국소 진행된 식도암환자에서 동시 항암화학방사선치료

정배권(Bae Kwon Jung),강기문(Ki Mun Kang),이경원(Gyeong Won Lee),강정훈(Jung Hoon Kang),김훈구(Hoon Gu Kim),이원섭(Won Seob Lee),채규영(Gyu Young Chai) 대한방사선종양학회 2009 Radiation Oncology Journal Vol.27 No.2

목 적: 국소 진행된 식도암으로 동시 항암화학방사선치료를 시행한 고령의 환자들을 대상으로 동시 항암화학방사 선치료에 대한 효과를 알아보고자 하였다. 대상 및 방법: 2001년 1월부터 2007년 7월까지 병리학적 편평상피세포암으로 확인 된 65세 이상의 식도암 환자 중 동시 항암화학방사선치료를 받은 28명을 대상으로 후향적 분석을 하였다. 환자의 병기는 IIa 8명(28.8%), IIb 10명(35.7%), III 10명(35.7%)이었다. 방사선치료는 6 MV 또는 10 MV X-선으로 45∼63 Gy (중앙값: 59.4 Gy)를 분할 조사하였다. 항암화학요법은 방사선치료 시작과 동시에 Cisplatin 75 mg/m2을 제1일에 정주하였고, 5-FU는 1,000mg/m2을 제1일에서 제4일까지 4일간 지속적 정주하여 방사선치료 동안은 3주 간격으로 2회 시행하였고, 방사선치료 후 2회의 항암화학요법을 추가 시행하였다.결 과: 추적관찰기간은 3∼72개월(중앙값: 19개월)이었다. 동시 항암화학방사선치료 후 치료 반응은 완전관해가39.3% (11명), 부분반응은 50.0% (14명), 무반응이 10.7% (3명)로 치료 반응률은 89.3% (25명)이었다. 전체 환자의 1, 2, 3년 생존율은 각각 55.9%, 34.6%, 24.2%이었고 중앙 생존기간은 15개월이었다. 완전관해, 부분반응, 무반응의 종양 반응을 보인 환자들의 2년 생존율은 각각 46.2%, 33.%, 0%이었다. 생존율과 관련된 예후인자로서 병기와 방사선치료 후 종양 반응이 유의하였다. 치료에 의한 합병증으로 사망한 환자는 없었다. 결 론: 고령의 국소 진행된 식도암환자에 대한 동시 항암화학방사선치료는 심각한 부작용 없이 비교적 효과적이었다. Purpose: The effect of concurrent chemoradiotherapy was analyzed in elderly patients when used in the treatment of locally advanced esophageal cancer. Materials and Methods: The retrospective analysis included 28 elderly patients aged 65 or older, with histopathologically confirmed squamous cell carcinoma of the esophagus, underwent concurrent chemoradiotherapy from January 2001 to July 2007. The squamous cell carcinoma disease stages included 8 patients (28.8%) in stage IIa, 10 patients (35.7%) in stage IIb, and 10 patients (35.7%) in stage III. Fractionated radiotherapy was performed with a 6 MV or 10 MV X-ray for 45∼63 Gy (median: 59.4 Gy). Chemotherapy was applied concurrently with the initiation of radiotherapy. A 75 mg/m2 dose of Cisplatin was intravenously administered on day 1. Further, 5-FU 1,000 mg/m2 was continuously administered intravenously from days 1 to 4. This regimen was performed twice at 3-week intervals during radiotherapy. Two cycles of consolidation chemotherapy was performed after radiotherapy. Results: The follow-up period was 3∼72 months (median: 19 months). The treatment responses after concurrent chemoradiotherapy included a complete response in 11 patients (39.3%), a partial response in 14 patients (50.0%), and no response in 3 patients (10.7%). The overall response rate was 89.3% (25 patients). The overall 1-, 2- and 3-year survival rates were 55.9%, 34.6% and 24.2%, respectively. The median survival time was 15 months. Two-year survival rates of patients with a complete response, partial response, and no response were 46.2%, 33.0%, and 0%, respectively. The stage and tumor response after concurrent chemoradiotherapy were statistically significant prognostic factors related with survival. No treatment-related deaths occurred in this study. Conclusion: Concurrent chemoradiotherapy is a relatively effective treatment without serious complications in elderly patients with locally-advanced esophageal cancer.

Cardiac arrest associated with aortic valve regurgitation

Chai, Hyun Suk,Lee, Suk Woo,Park, Jung Soo,Kim, Sang Chul,Lee, Ji Han,Kim, Hoon Elsevier 2018 The American journal of emergency medicine Vol.36 No.2

<P><B>Abstract</B></P> <P>Blunt chest trauma can cause not only damage to the thoracic cage, but can also injure intracardiac structures including the papillary muscles, chordae tendineae, and valve leaflets. Aortic valve (AV) injury secondary to blunt chest trauma is a rare occurrence. Clinically, AV injury may be missed during the initial post-trauma assessment due to the lack of suspicion of cardiac involvement. Thus, the diagnosis of AV injury is often delayed or missed for a time interval of days to months. As a consequence, the traumatic AV regurgitation can rapidly or progressively lead to congestive heart failure unless surgically corrected. Therefore, emergency physicians should be aware of the possibility of intracardiac structure injury, such as valvular injuries, after blunt chest trauma. Guidelines for the appropriate use of bedside cardiac ultrasound (BCU) recommend BCU should be performed in all patients with new murmurs for clinically significant valvular lesions that could potentially change management.</P> <P>We described the case of a 73-year-old female patient with AV injury after blunt trauma. She experienced cardiac arrest (CA) secondary to a moderate-to-severe traumatic AR, which was successfully treated with emergency AV replacement. We discuss how to diagnose and manage a CA patient, aided by BCU, with ventricular failure associated with persistent AV regurgitation. To the best of our knowledge, this is the first case report on CA associated with isolated rupture of bicuspid AV rupture and AV regurgitation secondary to blunt chest trauma because of the lack of early suspicion of AV injury.</P>