대구지역 가로수잎의 중금속

이찬형,윤현숙,박연준,권종대,노기철,장성환 한국환경과학회 2002 한국환경과학회지 Vol.11 No.12

This study was conducted to determine the contents of heavy metals in leaves of roadside trees according to different growth stages in Daegu city. The orders of heavy metal contents in leaves of roadside tree and soil were Fe〉Mn〉Zn〉Pb〉Cu〉Cr〉Cd and Fe〉Mn〉Zn〉Cu〉Pb〉Cr〉Cd, respectively. The contents of heavy metals in leaves of roadside trees and soil showed an increasing tendency as the levels of traffic volume increased. The contents of heavy metals in leaves on October were higher than those on May.

갈륨액체금속 이온원과 인듐액체금속 이온원의 빔 특성에 대한 연구

현정우,임연찬,정강원,정원희,박철우,이종향,강승언 한국공작기계학회 2005 한국공작기계학회 춘계학술대회논문집 Vol.2005 No.-

본 연구에서는 인듐 액체금속이온원을 제작하여 빔 특성에 대해 연구를 하였으며, 기존에 연구를 하였던 갈륨 액체금속이온원의 빔특성과 비교 분석 하였다. 빔특성 분석을 위해 빔 안정도, 전류-전압특성곡선, 에너지 퍼짐을 측정하였다. 액체금속이온원에 사용되는 액체금속 저장소 및 바늘전극(tip)은 500μm의 직경을 갖는 텅스텐을 사용하였으며, 국내에서 제작된 제품을 사용하였다. 액체금속 저장소의 구조는 이전에 구상하여 연구가 이루어진 6개의 pre-etching된 텅스텐와이어(wire)가 묶여진 형태를 사용하였다.

HFC-134a와 대체냉매 HFC-152a에 CF_3I를 혼합한 자동차냉매 특성

권일욱,박찬수,홍경한,문기선,최운수,서의경,윤갑식,이종인,하옥남 朝鮮大學校 機械技術硏究所 2002 機械技術硏究 Vol.5 No.1

These days, an attention of environment has been increasing all over the world. to prevent the green house effect and destruction of an ozone layer, an ozone destruction potential(ODP) be zero and a refrigerant for low global warming potential(GWP) is needed. HFC-134a, in which hydrogen is mixed instead of chlorine is a refrigerant used for automobile conditioners and its destruction potential is ecologically zero. However, it is not considered as a perfect substitutive refrigerant as its GWP is high. It is studied refrigerant mixtures in which HFC-134a, HFC-152a and CF_3I with low GWP and zero ODP are mixed by experimentally and concluded as follows; 1. with the variation of speed of compressor outside temperature and flow rate, the heat of evaporator and compressor and coefficient of performance was varied, and influenced the air conditioner. 2. The pressure of evaporator was decreased with increasing the speed of compressor and that of the refrigerant HFC-134a was higher 21% than that of azotrope refrigerant mixed with CF_3I. The overall capacity of condensor and evaporator was increased and HGC-134a was higher than azotrope refrigerant mixed with CF_3I 3. The capacity of evaporator with the refrigerant HFC-134a was higher 6% than azotrope refrigerant mixed with CF31 and the required power with zaotrope refrigerant mixed with CF_3I was higher 11% than that of HFC-134a. 4. The COP of the refrigerant FHC-134a was higher 31% in 1000RPM. when outside temperature was increased, COP was decreased. 5. Performance of HFC-134a is better than azotrope refrigerant mixed with CF_3I but prefered zaotrope refrigerant mixed with CF_3I considering the environment.

출력귀환과 스카이 훅 제어 방식에 의한 차량 현가 장치의 성능에 관한 연구

김재열,이규태,송찬일,정동화,서윤종,유신 한국공작기계학회 1996 한국생산제조학회지 Vol.5 No.4

The dynamic model of the suspension system is developed by using both sky-hook control and output feedback control techniques, based on the performance sensitivity index. Many vehicles use sky-hook control theory operated with only one sensor, due to relatively low cost and easy implementation. On the other hand, output feedback control implemented with state variables has difficulties in measuring such as tire deflection, etc.

인슐린 비의존성 당뇨병에 동반된 심상성 천포창 1 례

이상준,박진용,임태형,윤영호,권순대,남창욱,허규찬,박근용,구본식,김상표,장종억 啓明大學校 醫科大學 1997 계명의대학술지 Vol.16 No.3

저자들은 인슐린 비의존형 당뇨병 환자에서 통증성 구강내 미란 및 전신성 수포성 미란을 동반한 심상성 천포창 1예를 경험하였기에 문헌고찰과 함께 보고하는 바이다. Various skin conditions such as diabetic dermopathy, necrobiosis lipoidica diabeticorum, bullosis diabeticorum, granuloma annulare occur frequently in diabetes, although common lesions may be associated by chance. Pemphigus vulgaris(PV) is a blistering skin disease seen predominantly in elderly patients. This disorder is characterized by the loss of cohesion between epidermal cells with the resultant formation of intraepidermal blisters. These blisters rupture easily, leaving denuded areases that may crust and enlarge peripherally. In half or more of patients, lesions begin in the mouth: approximately 90% of patients have oromucosal involvement at some time during the course of their disease. But the relationship of this disorder with diabetes is not clear. We experienced a case of pemphigus vulgaris associated with NIDDM in 67 years old woman who was admitted due to painful oral ulcer and control of blood glucose, so we present this case with a review of literatures.

Diagnosis and Management of Heart Failure in Chronic Liver Disease

( Jong-chan Youn ) 대한간학회 2016 Postgraduate Courses (PG) Vol.2016 No.1

There is a mutual interaction between the heart and the liver and understanding these mutual relationship between the liver and the heart is important for both hepatologists and cardiologists. Hepato-cardiac diseases can be classified into heart diseases affecting the liver, liver diseases affecting the heart, and conditions affecting the heart and the liver at the same time. Acute and chronic heart failure may lead to acute ischemic hepatitis or chronic congestive hepatopathy. Treatment in these cases should be directed to the primary heart disease. In patients with advanced liver disease, cirrhotic cardiomyopathy may develop including hemodynamic changes, diastolic and systolic dysfunctions, reduced cardiac performance and electrophysiological abnormalities. Cardiac evaluation is important for patients with liver diseases especially before and after liver transplantation. Liver transplantation may lead to the improvement of all cardiac changes and the reversal of cirrhotic cardiomyopathy. There are systemic diseases that may affect both the liver and the heart concomitantly including congenital, metabolic and inflammatory diseases as well as alcoholism. Here, we will briefly review the clinical significance of cirrhotic cardiomyopathy and the cardiovascular challenges in liver transplantation candidates, as well as evidence-based recommendations for their evaluation and management.

Severe Hypothyroidism Induced by Thyroid Metastasis of Colon Adenocarcinoma: A Case Report and Review of the Literature

YOUN, Jong Chan,RHEE, Yumie,PARK, Soo Young,KIM, Won Ho,KIM, Soo Jung,CHUNG, Hyun Cheol,HONG, Soon Won,LIM, Sung-Kil The Japan Endocrine Society 2006 Endocrine journal Vol.53 No.3

<P>An 85-year-old man who had undergone a right hemicolectomy for colon cancer presented with severe hypothyroidism and hoarseness 21 months after the operation. The serum thyrotropin (TSH) was markedly elevated to 118.14 μIU/mL and serum free thyroxine (fT4) level was markedly suppressed to 0.34 ng/dL. Symptoms of hoarseness and neck swelling were already evident 4 months prior at which time tests for normal thyroid function were performed. The patient was referred due to aggravated pain on his diffusely enlarged hard goiter. An enlarged thyroid with some calcification was noticed in the neck ultrasonography with multiple cervical lymphadenopathies. Core biopsy of the thyroid gland showed invasion of poorly differentiated adenocarcinoma cells. Immunohistochemical studies showed positive staining only for carcinoembryonic antigen (CEA). There were multiple lung parenchymal nodules and adrenal masses at the time of evaluation. The patient was started on palliative chemotherapy with thyroid hormone replacement and gradually became euthyroid. From these findings and the clinical observations, thyroid metastasis with hypothyroidism developing acutely from metastatic colon adenocarcinoma was diagnosed.</P>

Korean Society of Heart Failure Guidelines for the Management of Heart Failure: Treatment

Jong-Chan Youn,Darae Kim,Jae Yeong Cho,Dong-Hyuk Cho,Sang Min Park,Mi-Hyang Jung,Junho Hyun,Hyun-Jai Cho,Seong-Mi Park,Jin-Oh Choi,Wook-Jin Chung,Byung-Su Yoo,Seok-Min Kang 대한심장학회 2023 Korean Circulation Journal Vol.53 No.4

The Korean Society of Heart Failure (KSHF) guidelines aim to provide physicians with evidence-based recommendations for the management of patients with heart failure (HF). After the first introduction of the KSHF guidelines in 2016, newer therapies for HF with reduced ejection fraction, HF with mildly reduced ejection fraction, and HF with preserved ejection fraction have since emerged. The current version has been updated based on international guidelines and research data on Korean patients with HF. Herein, we present Part II of these guidelines, which comprises treatment strategies to improve the outcomes of patients with HF.

Increased Risk with Older Donor Age and More Frequent Pre-transplant ECMO: the Second Official KOTRY Report

Jong-Chan Youn,In-Cheol Kim,Nam-Hee Park,Hyungseop Kim 대한심장학회 2019 Korean Circulation Journal Vol.49 No.8

Adiponectin and progression of arterial stiffness in hypertensive patients

Youn, Jong-Chan,Kim, Changsoo,Park, Sungha,Lee, Sang-Hak,Kang, Seok-Min,Choi, Donghoon,Son, Nak Hoon,Shin, Dong-Jik,Jang, Yangsoo Elsevier 2013 INTERNATIONAL JOURNAL OF CARDIOLOGY Vol.163 No.3

<P><B>Abstract</B></P> <P><B>Background</B></P> <P>Recent studies suggest that adiposity is associated with arterial stiffness. However, it is unclear which adipokine or what adiposity related parameters are related with the progression of arterial stiffness. We hypothesized that in hypertensive patients, initial levels of adipokines such as adiponectin and resistin are related to the progression of arterial stiffness, which has been proven to be associated with increased risk of cardiovascular events.</P> <P><B>Methods</B></P> <P>One hundred forty one consecutive patients with treated essential hypertension (81 men, 57.7±8.2years) were enrolled. Pulse wave velocity (PWV) was measured at baseline, and after 24months. Clinical variables and laboratory findings at the time of initial enrollment were analyzed to reveal the determinants of arterial stiffening.</P> <P><B>Results</B></P> <P>Mean heart to femoral PWV (hfPWV) was 992±202cm/s at baseline, and 1021±263cm/s at 24months follow up. hfPWV progressed in seventy two patients (51.1%) during follow up period. In patients with hfPWV progression, mean plasma adiponectin level was significantly lower than patients with nonprogression (progressor: 5.18±3.21μg/ml, non-progressor: 7.02±5.19μg/ml, <I>p</I> =0.013). Multivariate regression analysis revealed plasma adiponectin level to being an independent predictor of hfPWV changes (ß=−0.018, <I>p</I> =0.032) when controlled for age, gender, SBP changes, BP control and HOMA.</P> <P><B>Conclusions</B></P> <P>Plasma adiponectin levels are associated with progression of arterial stiffness in hypertensive patients. These findings may be one explanation for the high association between adiposity and arterial stiffness in hypertensive patients.</P> <P><B>Research Highlights</B></P> <P>► The association between adiposity and hypertension has been well documented. ► We sought to reveal what adipokine is related with arterial stiffening. ► Plasma adiponectin levels are associated with arterial stiffening in hypertensive patients. ► These findings may partly explain the high association between adiposity and hypertension.</P>