흰쥐에서 paraquat독성에 미치는 tumor necrosis factor-α의 영향

차종희,박정수,양성훈,박재윤,이병래 조선대학교 2000 The Medical Journal of Chosun University Vol.25 No.2

Background : The toxicity of paraquat is due to the oxygen-derived radicals formed by the reaction of oxygen with bipyridylium radical cations. Tumor necrosis factor (TNF)-α induces the synthesis of mitochondrial manganese superoxide dismutase (Mn-SOD) and other protective proteins in a variety of tumor cells and these protein contribute to a protect tumor cells from free radical injury. In this study, the effects of TNF-α on paraquat-induced toxicity were investigated in rats. Methods : Experimental animal used was Sprague-Dawley male rat, body weight 150-200g. The paraquat toxicity was determined by survival rate. The SOD, catalse, and glutathione peroxidase(GSHPx) activity were spectrophtomerically determined by Crapo method, Aebi method and Flohe method, respectively. Results : The survival rate of paraquat-intoxicated rats was decreased by subctaneous injection of TNF-α. However, the survival rate of paraquat injected rats were increased by pretreatment of TNF-α, comparing to saline pretreatment. The liver SOD activity was increased significantly by TNF-α treatment, but kidney and lung enzyme was unaltered in TNF-α treated-rats, comparing to normal control rats. The increment of liver SOD activity by TNF-α treatment was dose- and time-dependant SOD activity of kidney and lung of rats were not changed by TNF-α injection. The activities of catalase and glutathione peroxidase and contents of thiobarbituric acid reactive substance(TBARS) in liver were not changed by TNF-α treatment. Conclusion : From these result, TNF-α potentiate paraquat toxicity in rats but TNF-α pretreatment reduce paraquat induced toxicity. Protective effect may be resulted from the increased liver SOD activities by TNF-α.

Polaron Hopping in the K_(2)O · B_(2)O_(3) · V_(2)O_(5) Glasses

차유정,강재필,홍성덕,김복수,김영훈,서용문,송승기 명지대학교 자연과학연구소 2005 자연과학논문집 Vol.24 No.-

K_(2)O · B_(2)O_(3) · V_(2)O_(5) 계 유리의 조성비에 따른 밀도, 굴절율, 전이온도, 천이금속이온비율 등과 직류 전기 성질을 100~450K 온도영역에서 연구하였다. 실험결과를 비정질 반도체에 관한 전기전도에 대한 이론 모델을 이용하여 분석하였다. 고온 영역에서는 직류전도도의 온도 의존성을 Mott의 포논-도움껑충뛰기 전도모델로 분석할 수 있었다. 활성화에너지는 0.28~0.33 eV로 시료내 V_(2)O_(5) 의 양이 증가할수록 감소하는 경향을 보인다. 저온 영역에서 직류 전기전도도는 Mott의 가변거리 껑충뛰기(variable-range hopping)전기전도도와 잘 일치하며, N(E_(F))값은 국지화 상태에서와 같다. The dc conductivity of K_(2)O-B_(2)O_(3)-V_(2)O_(5) glasses has been investigated in the temperature range 100~450K and physical parameters such as density, refractive indices, glass transition temperature and fraction of reduced transition-metal ion, were observed for various compositions. The experimental results are analyzed with reference to theoretical models proposed for electrical conduction in amorphous semiconductors. The analysis shows that at high temperature region the temperature dependence of the dc conductivity is consistent with Mott's model of phonon-assisted hopping of small polarons. The values of activation energy are 0.28~0.33 eV and decrease with increasing V_(2)O_(5) content in the sample. The lowtemperature dc conductivity data can be well fitted to Mott's variable-range hopping conductivity and the values of N(E_(F)) are also reasonable for localized states.

우치 법랑질의 레이저 및 산부식처리 후 결합강도에 관한 실험적 연구

차경,김재곤,백병주,이승익 大韓小兒齒科學會 1996 大韓小兒齒科學會誌 Vol.23 No.1

The purpose of this study was to determine the optimal energy level to the enamel surface of bovine teeth when they are irradiated by pulsed Nd:YAG laser and was to compare acid etching with laser etching. For the study, the labial enamel surfaces of extracted intact bovine teeth were irradiated with normal pulsed Nd:YAG laser by six different energy of 30, 60, 80, 100, 120 and 160mJ. The author observed to enamel surface with a scanning electron microscope and measured the shear bond strength between etched enamel surface and composite resin by universal testing machine with a crosshead speed of 1mm/min. and investigated difference acid and laser etching group. The obtained results were as followng : 1. The shear bond strength were 24.26 MPa in Group Ⅰ, 5.50 MPa in Group Ⅱ, 5.77 MPa in Group Ⅲ, 5.90 MPa in Group Ⅳ, 6.01 MPa in Group Ⅴ, 6.34 MPa in Group Ⅵ, 6.24 MPa in Group Ⅶ. Acid etching Group(GroupⅠ) was showed higher bond strength than other laser etching groups(p<0.05). 2. In laser etching groups, the shear bond strength was highest in 120mJ energy level(Group Ⅵ). 3. Group Ⅱ, Ⅲ and Ⅳ, below 80mJ energy level were observed only microcrack and small projection in 80mJ energy level(Group Ⅳ) and group Ⅴ, Ⅵ and Ⅶ were observed small pore and crater in 5∼9㎛ diameter, especially in 120mJ energy level(Group Ⅵ).

자가 골수 중간엽줄기세포와 생분해성 고분자 스캐폴드를이용한 조직공학적 인공혈관 제조

조승우,김동익,박희정,임상현,전오주,김수현,김영하,최차용,이민재,김종성,장인성,김병수 대한혈관외과학회 2003 Vascular Specialist International Vol.19 No.2

ADP에 의해서 활성화된 인혈관세포의 Prothrombin과 골타액단백 부착에 관여하는 Integrin avβ3, avβ5, a5β1의 특성

주승재,최휘,김성만,차태준,이재우 고신대학교 의학부 2003 高神大學校 醫學部 論文集 Vol.18 No.1

Background : One of the most important features of integrins is that they exist in active and inactive states. Adenosine diphosphate (ADP), which is usually secreted from activated platelets, may activate integrins on vascular on vascular cells. Each integrin has its own activation-dependent ligands that have much higher affinity to active form than inactive one. Integrins that might mediate adhesion of human vascular cells to prothrombin(PT) and bone sialoprotein (BSP) after ADP stimulation were investigated. Methods : PT and BSP were used as activation-dependent ligands in adhesion assay. Adhesions of human umbilical vein endothelial cells (HUVEC) and human aortic smooth muscle cells (HASMC) were measured after stimulating with 100 μM of ADP, using ligand-coated 24-well plate and Fluorescence Multi-Well Plate Reader. Results : ADP activated HUVEC and HASMC to increase adhesions to PT and BSP in a dose-dependent manner. Adhesions of ADP-stimulated HUVEC to PT and BSP were almost completely inhibited by c7E3, a blocking monoclonal Ab to integrin β₃(96% and 92% inhibition, respectively), but not by P5H9, a blocking monoclonal Ab to integrin α_vβ_5. Adhesion of ADP-stimulated HASMC to PT was completely blocked by P5H9 (92% inhibition), but was not affected by c7E3. Adhesion of ADP-stimulated HASMC to BSP was partially inhibited either by P5H9 (46% inhibition) or by JBS5, a blocking monoclonal Ab to integrin inhibition), but was not affected by c7E3. However, it was completely blocked by cRGD (93% inhibition). Conclusion : These results indicate that the adhesion of ADP-stimulated HUVEC to PT or BSP was mediated by integrin α_vβ₃ and several integrins appeared to be involved in the adhesion of ADP-stimulated HASMC. While the adhesion of HASMC to PT was mediated by integrin α_vβ_5, the adhesion to BSP was associated with integrins α_vβ_5 and α_5β₁.

트리스디에틸아미노수소화알루미늄 리튬의 합성과 환원특성

이재철,박기석,차진순,정승원 嶺南大學校附設 基礎科學硏究所 1988 基礎科學硏究 Vol.8 No.-

The stoichiometries and approximate rates on the reaction of representative organic compounds with a new reducing agent, lithium tris(diethylamino)aluminum hydride (LTDEA), prepared from the reaction of lithium aluminum hydride and 3 equivdiethylamine, have been examined systematically under the standardized conditions(THF,0℃) in order to characterize its reducing power. The introduction of dialkylamino group to LiAIH₄modifies the reducing characteristics of parent hydride. The reagent appears to be a mild, selective reducing agent. Especially, the reagent shows the possibility to reduce carboxylic acids, esters, amides, and nitriles. If the full scope of the reducing characteristics of this reagent has been completed, the utility in organic synthesis should be widely spread.

흰쥐에서 염화비닐 폭로수준에 따른 소변내 thiodiglycolic acid 농도의 변화

왕승준,차봉석,노재훈,신동천,김명수,전근재 大韓産業醫學會 1999 대한직업환경의학회지 Vol.11 No.4

Objectives : It is the objective of this research to identify the variation of thiodiglycolic acid(TdGA) in urine with vinyl chloride monamer(VCM) exposure levels through methylation. Methods : After rats were exposed to vinyl chloride monomer of 4 levels, 0㎎/㎥, 50㎎/㎥, 150㎎/㎥, 500㎎/㎥, respectively, of which urine was sampled in each sampling time of 0 hour, 2 hours, 4 hours, 8 hours, 16 hours, 36 hours, 48 hours. After urine had been methylated with diazomethane in the preliminary experiment and the peak of 146 m/z had been verified, the main experiment was done. Results : In the variation of TdGA with sampling times, concentration of TdGA increased rapidly in 4 hours and then decreased after 8 hours. When the variation of urinary TdGA concentration in urine according to exposure level of VGM was verified through Kruskal-Wallis statistical method at each sampling time, the significant increment with the exposure levels at 2 hours, 4 hours, 8 hours after exposure was clarified. Conclusion : TdGA concentration in urine with increment of VCM exposure level increased, especially significantly at 2 hours, 4 hours, 8 hours of sampling time.

유도선수들의 스포츠자신감 수준이 귀인형태에 미치는 영향

홍재표,차정훈,전승훈 한국스포츠리서치 2005 한국 스포츠 리서치 Vol.16 No.2

The present study was designed to examine the effect of sport-confidence on attributional perceptions across male and female fencers. Judo athletes reported their sport-confidence, attribution perceptions on Sport-Confidence Inventory. CDSⅡ(Causal Dimension Scale Ⅱ) According to the previous research findings related to the theme of the study, it was hypothesized that the independent variables of trait sport-confidence. state sport-confidence influence the dependent variable of attributional perceptions. and the relationships between the two kinds of variables were examined using two-way ANCOVA. The implications of the study are as follows : Firstly. Trait sport-confidence and state sport-confidence of judo athletes significantly affected the locus of contorl dimension. Secondly. Trait sport-confidence and state sport-confidence of judo athletes significantly affected the stability dimension. Thirdly, Trait sport-confidence and state sport-confidence of judo athletes significantly affected the contro lability dimension.

좌각차단을 동반한 심부전증 환자에 실시한 양심실 심박조율기 치료 : 증례 보고

김찬욱,차태준,김성만,김민대,권성일,서수홍,최병주,주승재,이재우 고신대학교 의학부 2002 高神大學校 醫學部 論文集 Vol.17 No.1

Epidemiological studies suggest that 30-50% of patients diagnosed with symptomatic congestive heart failure(CHF) have electrocardiographic evidence of a major intraventricular conduction delay, which may worsen left ventricular systolic and diastolic dysfunction through asynchronous ventricular contraction and paradoxical interventricular septal wall motion. Biventricular pacing is an emerging therapy allowing simultaneous electrical stimulation of the both ventricles with an implantable pacing system and it improves hemodynamics and well-being of patient by reducing ventricular asynchrony. Recently, we underwent biventricular DDD pacemaker implantation in a patient with CHF and Left bundle branch block and was significantly improved exercise tolerance and quality of life in that patient.

RC 프레임면내 조적채움벽의 내진성능 평가에 관한 실험적 연구

이정한,차승렬,강대언,오상훈,이용재,이원호,김상대 대한건축학회 2004 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.24 No.1(구조계)

The objectives of this study are 1) to find out the shear behavior and shear capacity of RC bare frames, brick-infilled RC frames, 2) to evaluate the equation of the shear capacity of two types of RC frames by comparison the Japanese Standard and modified equation adopting the test results. The main variable is the absence of brick infill wall. The test results show that the shear capacity of specimen IF-4.2 is 2.3 times as high as that of the specimen IF-4.2.The shear behavior of RC bare frame which is governed by predominant flexural yielding is changed to predominant shear yielding by affection of the brick infill wall. A comparison of the results obtained by the Japanese Standard equation and the modified equation to the test data indicates that the proposed equation is compatible with the test results.