• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2013.05a
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• pp.183-183
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• 2013

본 연구는 전착법으로 형성된 $Cu_2O$ 박막의 광특성 변화를 고찰한 것이다. 0.3M $CuSO_4$과 4M Lactic acid에 4M NaOH로 전해액의 pH를 조절하여 $Cu_2O$ 박막의 결정성 및 극성을 조절하였다. $Cu_2O$ 박막의 결정성 및 극성에 따른 광특성을 고찰한 결과, 극성인 (111)면에서 광특성이 우수함을 확인하였다. 하지만, 측정시간의 증가에 따라 표면에 Cu 금속이 형성되어 광전류가 감소함을 확인 할 수 있었다. rGO는 페르미전위가 $Cu_2O$ 환원 전위보다 위쪽에 위치한다. 따라서 $Cu_2O$ 박막위에 rGO를 형성시켜 Cu 발생반응을 제한하고 광전류를 증가시키고자한다.

• 건강소식
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• v.13 no.3 s.124
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• pp.2-7
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• 1989

예부터 농민은 가진 것이 땅밖에 없다고 얘기되어져 왔다. 도시의 사시사철 흥청거림과는 무관한 듯 가을 추수가 끝나야 비로소 돈을 만져보게 되는 농민들. 그들의 얼굴엔 부유함이나 깔끔한 보다는 부지런함과, 흙과 함께 살아온 텁텁함이 강하게 배어있다. 그러나 그들 역시 발달되는 문명 속에서 현대인이면 누구나 직면하게 되는 질병과 재해를, 그 흥청거림을 외면하듯 등져버릴 수는 없다. 그러나 그들에겐 그 위험으로부터 자신을 보호하기 위해 무엇을 준비한다는 것이 사실상 어렵다. 농협중앙회의 공제사업은 이런 처지의 농민을 위해 시작되었다고 볼 수 있다. 농협공제사업은 그 동안 다양한 복지환원사업을 실시해, 이제는 대다수의 농민에게 많은 호응을 받고 있다. 그것은 지난 ‘86년부터 실시되어온 무료건강검사의 과정 속에서 농민의 입을 통해 입증되어지고 있다. ’1인은 만인을 위해, 만인은 1인을 위해‘라는 모토아래 실시되고 있는 농협공제사업이 왜 농민으로부터 좋은 반응을 얻고 있는지, 농민이 진정으로 원하는 것이 무엇인지를 알아보기로 한다.

• Korean Journal of Materials Research
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• v.7 no.5
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• pp.374-380
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• 1997

열전재료 분말을 AI관에 진공봉입하고 형틀가입한 후 소결하는 새로운 방법으로 n형 B $i_{2}$T $e_{2.4}$S $e_{0.6}$를 제조하여 소결조건에 따른 소결성과 열전특성을 조사.분석하였다. AI은 소결시 열전재료와 반응하지 않아 보호 용기로 적합하였으며, 평균입도 195$\mu\textrm{m}$의 분말을 사용하여 성형압 280 MPa, 온도 400에서 50$0^{\circ}C$에서 소결할 경우 성능지수는 1.9x $10^{-3}$K였다.다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.11a
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• pp.432-435
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• 1997

In AC PDP, electrodes are covered with dielectric layer and the discharge is formed on the surface of the dielectric layer. MgO protection layer on the dielectric layer in PDP prevents a dielectric layer from sputtering and lowers the firing voltage due to a large secondary electron emission yield( ${\gamma}$ ). Until now, the MgO protection layer is mainly prepared by E-beam evaporation. However, there are some problems that is easy pollution and change of its characteristics with time and delamination. Therefore, in this study, MgO protection layer is prepared on dielectric layer by reactive R.F. magnetron sputtering with MgO target. Discharge characteristics and secondary electron emission coefficients of PDP are studied as a parameter of preparation conditions. Discharge voltage characteristics of the prepared MgO layer can be stable and improved by the annealing process in vacuum chamber.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2007.04a
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• pp.159-160
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• 2007

본 연구에서는 Si 타겟과 반응성 마그네트론 스퍼터링법을 적용하여 $SiO_xN_y$ 박막을 PET 필름상에 증착하였다. PET 필름상에 밀착력 증진 및 기판 표면 거칠기 제어를 위해 이온빔을 이용한 플라즈마 전처리를 수행하였다. 플라즈마 전처리 조건과 질소 가스 유량비에 따른 $SiO_xN_y$ 박막의 광학적 특성과 수분의 투습성에 대한 영향을 관찰하였다. 광학적 투과율은 전처리 및 조성비에 관계없이 95% 이상의 높은 광투과율을 보여주었다. 수분에 대한 투습 특성은 플라즈마 전처리 조건에 따라 다소 향상됨을 확인하였고, 질소 유량비가 증가함에 따라 투습 특성이 향상되었다.

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.6 s.165
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• pp.955-965
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• 2007

Safety helmets are used widely in various industries by workers since they are legally required to wear them. However, thermal discomfort is one of the major complaints from helmet users. To relieve this problem, frozen gelled packs can be considered for use inside the helmets. In this paper, tests were performed on humans to evaluate the physiological strains of wearing safety helmets and to investigate the effects of using frozen gelled packs inside the helmets. Experiments were conducted in a climatic chamber of WBGT $33{\pm}1^{\circ}C$ under four differed experimental conditions: 1) not wearing a safety helmet(NH); 2) wearing a safety helmet with frozen gelled pack A(HA); 3) wearing a safety helmet with frozen gelled pack B(HB); and 4) wearing only a safety helmet(OH). The results were as follows. First, when comparing NH with OH, physiological responses such as $\bar{T}_{sk},\;T_r$, HR and sweat rate were significantly higher in OH and subjective sensations were reported as less hot and more comfortable than NH(p<.05). Second, in regard to the frozen gelled packs inserted inside the safety helmets, some physiological responses in HA were different from those in HB, according to the two different types of packs. HA was hotter, more uncomfortable and less exhausted than HB. However, result from both HA and HB were lower than those from OH in terms of temperature and humidity inside safety helmet, sweat rate, $T_r$ increase, heat storage(p<.05). When wearing safety helmets with frozen gelled packs, it was shown that heat strain can be alleviated. These results are expected to help millions of workers who complain that wearing safety helmets is uncomfortable and messy.

• Pediatric Infection and Vaccine
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• v.25 no.1
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• pp.35-44
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• 2018

Purpose: This study aimed to evaluate the immunogenicity and safety of a trivalent inactivated influenza vaccine (TIV) among healthy Korean children and adolescents. Methods: From October to December 2008, 65 healthy patients aged 6 months to 18 years who visited Korea University Ansan Hospital for influenza vaccination were enrolled in this study. We measured the hemagglutinin inhibition antibody titers at baseline and 30 days after vaccinating enrollees with split influenza vaccine and calculated the seroprotection rates, geometric mean titers, and seroconversion rates. Local and systemic adverse events were assessed after vaccination. Results: The seroprotection rates against all three viral strains (A/H1N1, A/H3N2, B) were 87.7%, 89.2%, and 89.2% (${\geq}70%$), respectively; seroconversion rates were 44.6%, 73.8%, and 63.1% (${\geq}40%$), respectively; and seroconversion factors were 4.5, 8.4, and 10.5 (>2.5), respectively. The TIV immunogenicity was acceptable according to the CPMP (Committee for Proprietary Medicinal Products) criteria. Although 48 patients (73.8%) reported one or more adverse events, no severe adverse events such as anaphylaxis and convulsion were observed. Forty-two patients (64.6%) reported a local skin reaction, including redness (29.2%), pain (43.1%), or swelling (41.5%) of the injected site, and 26 (40.0%) reported a systemic reaction: fatigue (23.1%), myalgia (20.0%), headache (10.8%), arthralgia (10.8%), chills (9.2%), or fever (7.7%). Conclusions: This study shows that the immunogenicity of the TIV vaccine is acceptable. As there were no serious adverse events aside from local reactions and mild systemic reactions, this vaccine can be safely used among healthy Korean children and adolescents.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.4
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• pp.393-401
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• 2016

Ultraviolet (UV) irradiation from the sun is the primary environmental factor that causes skin damages including skin cancer and premature skin aging. Because, even the most powerful sunscreen can't always afford enough protection, it is necessary to enhance the defensive power of skin against UV. Recently, constitutive photomorphogenic protein-1 (COP1) has shown to contribute to the regulation of UVB response of keratinocytes. In this study, we represent that COP1 and its associated protein, de-etiolated 1 (DET1), might participate in photoaging process in human skin as Arabidopsis COP1 does sun-protective function in plants. After UVB irradiation, the decrease of COP1 and DET1 mRNA expression was followed by the increase of c-Jun total protein. Moreover, transfection with DNA vectors expressing COP1 and DET1 down-regulated the c-Jun total protein. We found that Zanthoxylum piperitum extract (ZE) up-regulated the expression of COP1 and DET1 on human keratinocytes, and inhibited the expression of MMP1 which is one of the genes regulated by c-Jun signal. In addition, ZE has been reported to stimulate PPAR-${\alpha}$ and strengthen the skin barrier. We found that ZE decreased the UVB-induced IL-6 and IL-8 in NHEK cells. In human study, ZE protected skin against UV-B induced erythema and erythema-induced pigmentation. These results indicate that ZE could be useful for the protection against the adverse effects of UV irradiation through various mechanisms.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.12
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• pp.1753-1760
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• 2010

This study was designed to investigate the protective effects of Sasa borealis leaves on high glucose-induced oxidative stress in human umbilical vein endothelial cells (HUVECs). Freeze-dried Sasa borealis leaves were extracted with 70% methanol and followed by a sequential fractionation with dicholoromethan, ethyl acetate, butanol and water. The ethyl acetate fraction from Sasa borealis leaves extract (ESLE) was used in this study because it possessed the strongest antioxidant activity among the various solvent fractions. Exposure of HUVECs to 30 mM high glucose for 48 hr resulted in a significant (p<0.05) decrease in cell viability, glutathion (GSH) concentration, activities of antioxidant enzymes including superoxide dimutase (SOD), glutathion peroxidase (GSH-px) and catalase, and a significant (p<0.05) increase in intracellular ROS and lipid peroxidation formation in comparison to the cells treated with 5.5 mM glucose. ESLE treatment decreased intracellular ROS and lipid peroxidation formation and increased cell viability, GSH concentration and expressions of SOD and catalase in HUVECs. These results suggest that ESLE may be able to protect HUVECs from high glucose-induced oxidative stress, partially through the antioxidative defense systems.

• Korean Journal of Oriental Medicine
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• v.5 no.1
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• pp.111-117
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• 1999

Free radicals are thought to be the most important cause of the reperfusion injury subsequent to ischemia. The antioxidant status of the tissue affected by ischemia-reperfusion is of great importance for the primary endogenous defense against the free radical induced injury. Therefore, antioxidant therapy has been shown to be beneficial in neurological disorders such as Alzheimer's disease and cerebral ischemia. In this study, the protective effects of Chungpesagan-tang (CST) was investigated against ischemia/reperfusion-induced cytotoxicity in SK-N-MC neuronal cells It was found out that low concentration of CST was highly effective in protecting neuronal cells against ischemia/reperfusion-induced cytotoxicity. The inhibitory effect of CST on malondialdehyde formation during ischemia/reperfusion-induced oxidative stress in SK-N-MC cells showed obvious dose-dependent responses. Also, CST showed relatively high inhibitory activity to xanthine oxidase induced by ischemia/reperfusion environment Therefore, it is thought that CST has both antioxidant and xanthine oxidase inhibitory effect and can be used for clinical applications for protection of neuronal cells from ischemia-reperfusion injury.