• Proceedings of the Korean Society of Applied Pharmacology
• /
• 1995.04a
• /
• pp.95-95
• /
• 1995

뇌신경 변성 / 퇴행과 관련된 중요한 병인론 중의 하나는 변성 과정에서 형성된 유리기(free radical)로 인한 항산화계의 평형 소실로 알려져 있다. Aspalatone (APT)의 예상되는 항산화 효능을 검정하기 위하여 본 실험에서는 Kainic acid (KA) 유발 뇌변성 모델을 적용하였다. KA 모델은 변연계의 간질성 경련과 신경세포 변성에 대하여 재현성 있는 병변 모델을 제공해 주며, 이와 같은 신경세포의 병독 기전에 산소 유리기가 관여함이 강력히 시사되고 있기 때문이다. KA 투여로 인하여 지속적이고도 전형적인 간질성 경련이 관찰되고 1일 이내에 높은 치사율을 보였으나 APT으로 인하여 그 간질성 경련 행위와 비율이 억제되고 KA 유발 치사율도 억제되었다. 최종 KA 투여 3일 후에 얻어진 흰쥐 해마 및 대뇌 피질에서 항산화 효소인 Superoxide dismutase (SOD), Catalase (Cat.), Glutathione peroxidase (GSH-PX) 및 과산화지질의 지표인 Malondialdehyde (MDA)를 검정하였다. 대조군에 비하여 KA는 뇌조직의 SOD-1을 유도하였으나, Cat.와 GSH-PX의 활성은 현저히 유도되지 않았고, 반면에 MDA 치는 현저히 증가하였다. 즉, Cat., GSH-PX와 같은 $H_2O$$_2$중화제가 동반 유도하지 않는 SOD의 유도는 세포내 축적되는 $H_2O$$_2$로 인하여 Fenton/Haber-Weiss 반응을 가속화하여 과산화지질화를 촉진함을 시사한다. APT 병용 투여로 SOD는 현저히 유도되지 않았으나 특히 Cat.가 현저히 유도되어지고 MDA는 억제되었다. 이와 같은 생화학적인 결과는 다음의 형태학적인 소견과 일치한다. Fos 관련 항원 (FRA)와 SOD-1을 면역세포화학 (Immunocytochemistry)적 방법으로 이중 표식 (double-labelling) 하였다. FRA는 KA로 인한 신경세포의 자극에 대한 지표로 응용하였고, SOD-1은 퇴행성 뇌질환에서 산화적 손상의 지표로 사용하였다. KA 투여로 해마의 dentate gyrus (DG) 내에 강한 면역환성 (immunoreactivity)이 나타났고 pyramidal cell layer (PCL)와 glia에 SOD-1이 강하게 염색되었다. APT 병용 투여로 상당수의 경련이 일어나지 않은 흰쥐는 해마의 DG에 FRA가 경미하게 염색되었고, PCL에 SOD-1도 경미하게 나타났으나, 경련이 나타난 쥐에서는 KA만을 투여한 흰쥐와 구별되지 않았다. 이상의 APT의 항산화 효과는 KA로 인한 뇌세포 변성 개선에 중요한 인자로 작용할 것으로 사료되나, 보다 명확한 APT의 기전을 검색하고 직접 임상에 응응하기 위하여는 보다 다양한 실험 조건이 보완되어야 찰 것으로 생각된다.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2012.02a
• /
• pp.281-281
• /
• 2012

연꽃잎 효과(Lotus effect)라 불리는 자가 세정 효과(self cleaning effect)는 연꽃이 항상 깨끗한 상태를 유지하는 것이 관찰되면서 꾸준히 관심에 대상이 되어 왔었다. 자가 세정 효과는 접촉각 $150^{\circ}$ 이상의 초소수성 표면에서 구현이 가능하며 이런 표면을 일상생활부터 산업분야까지 응용하고자 하는 많은 노력들이 있었다. 물질의 친수성 또는 소수성은 표면의 거칠기(roughness)와 표면에너지(surface energy)의 두 가지 특성에 의해 결정된다. 하지만 낮은 표면에너지 물질을 사용해도 접촉각 $150^{\circ}$ 이상의 초소수성 표면을 얻긴 힘들며, 표면의 거칠기를 증가시켜야 한다. PTFE (polytetrafluoroethylene)는 낮은 표면에너지를 가진 소수성 물질로 bulk일 경우 접촉각이 약 $108^{\circ}$이지만 거친 표면을 가진 박막으로 만들 경우 접촉각이 $150^{\circ}$ 이상의 값을 가지는 초수수성 표면이 가능한 물질이다. 특히, 초소수성 표면 이외에 우수한 내열성 및 내화학성 특성을 가지고 있어 디스플레이 및 태양전지 등의 자가세정(self cleaning) 보호막으로써 응용이 기대되고 있다. 본 연구에서는 HFPO (hexafluoropropylene)를 원료 가스로 이용하여, Si(100)과 유리 기판위에 Cat-CVD (Catalytic Chemical Vapor Deposition)법으로 PTFE 박막을 증착하였다. 텅스텐(W)을 촉매로 사용하였으며, 촉매온도가 $850^{\circ}C$이상인 조건에서 접촉각이 $150^{\circ}$ 이상인 초소수성 PTFE 표면을 쉽게 얻을 수 있었다. 특히 본 연구에서는 제막압력을 300 mTorr에서 700 mTorr까지 변화시켜 가며 유리와 Si 기판위에 증착하였다. Cat-CVD 제막압력을 변화시켜가며 증착된 PTFE 박막의 접촉각을 측정한 결과, 제막압력이 300 mTorr일 때 glass와 Si 기판위에 증착된 PTFE박막 표면에서의 접촉각은 각각 133, $117^{\circ}$였지만, 제막압력이 400 mTorr이상일 땐 $150^{\circ}$ 이상의 높은 접촉각을 갖는 초소수성 표면을 얻을 수 있었다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2005.11b
• /
• pp.140-143
• /
• 2005

The hybrid CAE/CAT methods are widely applied to product development in various fields because this method can predict the response of the whole system when a part of the system is changed. Especially, the hybrid CAE/CAT method is very useful to predict tile vehicle NVH characteristics after changing some parts of the vehicle. Target parts can be established on the basis of test models and FE models of the prototype constructed in the planning stage of car development. In this study, the topic was focused on the proper test-based FBS application process to predict vehicle NVH characteristic. First, the test-based FBS method was apply to vehicle substructure and car-body. And then the test-based model was replaced with FE model to apply hybrid CAE/CAT method. The replaced FE model was modified through the optimization process. The interior noise in vehicle during the drive was predicted with Modified FE model, then the predicted results were verified by experimenting with actual modified model.

• The Bulletin of The Korean Astronomical Society
• /
• v.44 no.2
• /
• pp.78.2-78.2
• /
• 2019

The temperature control of a scientific device is essential because extreme temperature conditions can cause hazard issues for the operation. We developed a software which can interact with the temperature sensor using the GMT SDK(Giant Magellan Telescope Software Development Kit) version 1.6.0. The temperature sensor interacts with the EtherCAT(Ethernet for Control Automation Technology) slave via the hardware adapter, sending and receiving data by a packet. The PDO(Process Data Object) and SDO(Service Data Object), which are the packet interacts with each EtherCAT slave, are defined on the TwinCAT program that enables the real-time control of the devices. The user can receive data from the device via grs(GMT Runtime System) tools and log service. Besides, we programmed the software to print an alert message on the log when the temperature condition changes to certain conditions.

• Journal of Veterinary Clinics
• /
• v.38 no.4
• /
• pp.174-178
• /
• 2021

A nine-year-old neutered male cat was presented with chronic cough and vomiting. Thoracic radiography showed regions of fatty opacity in the right caudoventral region. On positive contrast celiography, contrast agent did not move into thoracic cavity. Computed tomography revealed 7-mm diameter of defect at the right diaphragmatic crus and a 2-mm diameter defect at the left ventral diaphragmatic crus. Through the right diaphragmatic defect omental herniation was confirmed by the presence of contrast enhanced omental vessel running across the diaphragm. On exploratory thoracotomy, the omentum protruded into the thorax through the right diaphragmatic defect, and it contained a yellowish lipomatous mass. The protruded omentum containing a mass in the thorax was removed, and the right diaphragmatic defect was closed. Histopathologic examination revealed that the protruded omentum showed normal omental structure and the adipose mass showed lipoma surrounded by fibrous tissue. In conclusion, a thorough examination is necessary to confirm the origin of the mass located near the diaphragm.

• Journal of Nutrition and Health
• /
• v.29 no.7
• /
• pp.729-737
• /
• 1996

Activieties of hepatic cysteine desulfhydration was assessed in cats fed one of the following diets for 5 weeks : 20% protein, 0% taurine diet(LPOT) ; 20% protein, 0.15% taurine diet (LPNT) ; 60% protein, 0% taurine diet(HPOT) ; and 60% protein, 0.15% taurine diet(HPNT). Cats fed LPOT and HPOT had been maintained on a taurine-free diet for 6 weeks prior to the experiment in order to deplete body taurine. Activities of cysteine desulfhydration were determined by measuring the production of H235S from 35S-cysteine in the presence and absence of $\alpha$-ketoglutarate ($\alpha$-KG) in the incubation medium. The direct pathway via cysteine desulfhydrase appears to account for the major route of cysteine desulfhydration in the cat liver since the values obtained in the absence of $\alpha$-KG were between 81 and 88% of those obtained in the presence of $\alpha$-KG. Mean$\pm$SEM of the hepatic total desulfhydration activities(umol H2S.min-1.kg body wt-1)in cats fed LPOT, LPNT, HPOT and HPNT were 117$\pm$6, 135$\pm$10, 137$\pm$10, and 190$\pm$9, respectively. The capacity of hepatic cysteine desulfhydration (UA/kg body wt) was positively cerrelated not only with the dietary concentration of taurine but also with the concentration of protein.

• Korean Journal of Soil Science and Fertilizer
• /
• v.44 no.1
• /
• pp.53-57
• /
• 2011

The MuSI is known as a multiple stress resistant gene with several lines. A previous study using RT-PCR showed that the expression of MuSI gene in tobacco plant induced its tolerance to Cd stress. This study was conducted to examine the enhanced Cd tolerance of the MuSI transgenic tobacco plant through germination test and to understand the role of the involved antioxidant enzymes for the exhibited tolerance. Germination rate of MuSI transgenic tobacco was more than 10% higher than that of wild-type tobacco, and seedlings of MuSI transgenic tobacco grew up to 1.6 times larger and greener than seedlings of wild-type tobacco at 200 and 300 ${\mu}M$ Cd. From the third to the fifth day, CAT activities at 100 and 200 ${\mu}M$ Cd and APX activities at 100, 200 and 300 ${\mu}M$ Cd of MuSI transgenic tobacco were up to two times higher than those of wild-type tobacco. MuSI gene is shown to enhance the activities of antioxidant enzymes resulting in higher tolerance to oxidative stress compared with the control plant.

• KIEAE Journal
• /
• v.11 no.2
• /
• pp.59-65
• /
• 2011

To analyze changes in the water-balance before and after using decentralized rainwater management facilities, this study carried out hydrologic modeling based on data including roof planting, rainwater use, infiltration and detention facilities applied to the sites. The results of the analysis are as follows: First, the total runoff quantity after facility installation was about 24% less than before. In particular, it showed that the surface runoff declined significantly. Second, the analysis of the effects of different decentralized rainwater management facilities revealed that the rooftop planting contributed to about a 3.5 times increase in actual evaporation than before. Third, the analysis of the effect of decentralized management facilities by different rainfall events showed that it turned to have about a 30% decreasing effect after facility installation for a monthly rainfall over 500mm or so and about 50% declining effect for a monthly rainfall about 200mm. As discussed above, the study confirmed that it is important to implement decentralized rainwater management facilities to improve inevitable changes in water-balance arising from development as it would be a significant alternative for sustainable urban development.

• Journal of Veterinary Clinics
• /
• v.37 no.6
• /
• pp.350-354
• /
• 2020

Feline chronic lymphocytic leukemia (CLL) is a rare disease. Its diagnosis is not simple because of the absence of clinical signs and the presence of mature lymphocytosis. An 11-year-old female spayed Russian Blue cat was referred to the veterinary medical teaching hospital for lethargy, diarrhea, weight loss, and inappetence. Marked lymphocytic leukocytosis and a significantly increased number of small-to-intermediate-sized lymphocytes in the peripheral blood were found on hematological examination. The results of the feline leukemia virus and immunodeficiency virus test were negative. Further, mild splenomegaly was detected. Bone marrow aspirate analysis revealed mature lymphocytosis and a clonally rearranged T cell receptor gene with the polymerase chain reaction (PCR) for antigen receptor rearrangement assay. Flow cytometric immunophenotyping showed a homogeneous population of CD5+/CD21-T-cells in the peripheral blood and bone marrow. According to the results of the aforementioned examinations, CLL was diagnosed. Treatment was not initiated at the time of diagnosis because the clinical signs were mild and did not affect the quality of life. This report describes the clinical findings and use of advanced diagnostic tools such as molecular clonality analysis and immunophenotyping for the diagnosis of feline CLL.

• CELLMED
• /
• v.4 no.4
• /
• pp.26.1-26.9
• /
• 2014

Reactive oxygen species are known to mediate various pathological conditions associated with malaria. In this study, the antioxidant potential of Clerodendrum violaceum leaf extracts, an indigenous antimalarial remedy, was evaluated. Total phenol, flavonoid, selenium, vitamins C and E contents of Clerodendrum violaceum leaf extracts were determined. The free radical scavenging activities of the extracts against DPPH, superoxide anion and hydrogen peroxide coupled with their reducing power were also evaluated in vitro. Moreover, responses of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR) in a rodent malaria model to a 4-day administration of Clerodendrum violaceum leaf extracts were also evaluated. The methanolic extract was found to contain the highest amounts of antioxidant compounds/element and also demonstrated the highest free radical scavenging activity in vitro. The results showed a significant decrease (p < 0.05) in SOD and CAT activities with a concurrent significant (p < 0.05) increase in GPx and GR activities in both erythrocytes and liver of untreated Plasmodium berghei NK65-infected animals compared to the uninfected animals. The extracts were able to significantly increase (p < 0.05) SOD and CAT activities and significantly reduce (p < 0.05) GPx and GR activities in both the liver and erythrocytes compared to those observed in the untreated infected animals. The results suggest the augmentation of the antioxidant system as one of the possible mechanisms by which Clerodendrum violaceum extract ameliorates secondary effects of malaria infection, alongside its antiplasmodial effect in subjects.