• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제28권5호
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• pp.364-371
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• 2002

Many chemical compopunds are converted into reactive electrophilic metabolites by the oxidative(Phase I) enzymes, which are mainly cytochrome P-450 enzyme(CYPs). Phase II conjugating enzymes, such as glutathione S-transferase(GST), usually act as inactivation of enzymes. Genetic polymorphisms have been found to be associated with increased susceptibility to cancer of the lung, bladder, breast and colorectal. Many of the polymorphic genes of carcinogen metabolism show considerably different type of cancer among different ethnic groups as well as individuals within the same group. The aim of this study is (1) to establish the frequencies of genetic polymorphisms of GSTM1 and CYP1A1 in Korean oral squamous cell carcinoma(SCC), (2) to associate oral SCC with the risk of these genetic polymorphisms. The genetic polymorphisms of the GSTM1 and the CYP1A1 genes among 50 Korean oral SCC were analyzed using polymerase chain reaction(PCR). The results suggest that the homozygote and the mutant type of CYP1A1 MspI polymorphisms may be associated with genetic susceptibility to oral SCC in Korean. A combination of the GSTM1 null type with the homozygote(m1/m1), and the mutant(m2/m2) type of CYP1A1 MspI polymorphisms showed a relatively high risk of oral SCC in Korean. In the smoking group, the GSTM1 wild genotype may be the high risk factor of oral SCC in Korean. These data coincide with the hypothesis which states that different susceptibility to cancer of genetic polymorphisms exist among different ethnic group and different types of human cancer.

• 농업과학연구
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• 제47권2호
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• pp.361-373
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• 2020

Integrins such as lymphocyte function-associated antigen -1 (LFA-1) have an essential role in T cell immunity. Integrin activation, namely, the transition from the inactive conformation to the active one, takes place when an intracellular signal is generated by specific receptors such as T cell receptors (TCRs) and chemokine receptors in T cells. In an effort to explore the molecular mechanisms underlying the TCR-mediated LFA-1 activation, we had previously established a high-throughput cell-based assay and screened a chemical library deposited in the National Institute of Health in the United States. As a result, several hits had been isolated including HIKS-1 (Benzo[b]thiophene-3-carboxylic acid, 2-[3-[(2-carboxyphenyl) thio]-2,5-dioxo-1-pyrrolinyl]-4,5,6,7-tetrahydro-,3-ethyl ester). In an attempt to reveal the mode of action of HIKS-1, in this study, we did drug affinity responsive target stability (DARTS) assay finding that HIKS-1 interacted with the IQ motif containing GTPase activating protein 1 (IQGAP1), a 189 kDa multidomain scaffold protein critically involved in various signaling mechanisms. Furthermore, the cellular thermal shift assay (CETSA) provided compelling evidence that HIKS-1 also interacted with IQGAP1 in vivo. Taken together, it can be concluded that HIKS-1 interferes with the TCR-mediated LFA-1 activation by interacting with IQGAP1 and thereby disrupting the signaling pathway for LFA-1 activation.

• 한국진공학회:학술대회논문집
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• 한국진공학회 1995년도 제9회 학술발표회 논문개요집
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• pp.154-154
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• 1995

The Xu-Tec process is also called the double glow surface alloying technology and is a new method of surface metallurgy which can produce an alloy layers with sp ecial phisical and chemical properties on the surface of common and inexpensive mater ials. Many super alloys and alloy steels, sueh as nickel base alloys, high speed steels and staiinless steels, have been produced by Xu-Tee Process on the surfaces of carbon steels. The depth of the alloy lasyers may vary from several microns up to 300 micr ons with alloying elements in a concentration of few percentage to 100%. World wide patents for Xu-Tec process have been granted in the United states, Canada, United Ki ngdom, Australia and Japan. High performance saw blades have been successfully produced by the Xu-Tee process with much simper processing steps and less cost than bimetal high speed saw blades. A comparison of the cutting times and wear rates of the Xu-Tee blades with the conventional bimetal blades has been made. The Xu-Tee bIases demonstrates sim ilar or better performance than bimetal blades. A Xu-Tec Unit for the commercial pr oduction of Xu-Tec saw blades has been designed and manufactured. This Unit can t reat 10,000 haek saw blades at one time. Three Xu-Tec hack saw blades production I ines have been set up in China. China.

• Journal of Electrical Engineering and information Science
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• 제2권5호
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• pp.65-71
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• 1997

We present heterojunction solar cells with a structure of metal/a-Si:H(n-i-p)/poly-Si(n-p)/metal for the terrestrial applications. This cell consists fo two component cells: a top n-i-p junction a-Si:Hi cell with wide-bandgap 1.8eV and a bottom n-p junction poly-Si cell with narrow-bandgap 1.1eV. The efficiency influencing factors of the solar cell were investigated in terms of simulation an experiment. Three main topics of the investigated study were the bottom cell with n-p junction poly-Si, the top a-Si:H cell with n-i-p junction, and the interface layer effects of heterojunction cell. The efficiency of bottom cell was improved with a pretreatment temperature of 900$^{\circ}C$, surface polishing, emitter thickness of 0.43$\mu\textrm{m}$, top Yb metal, and grid finger shading of 7% coverage. The process optimized cell showed a conversion efficiency about 16%. Top cell was grown by suing a photo-CVD system which gave an ion damage free and good p/i-a-Si:H layer interface. The heterojunction interface effect was examined with three different surface states; a chemical passivation, thermal oxide passivation, and Yb metal. the oxide passivated cell exhibited the higher photocurrent generation and better spectral response.

• 한국한의학연구원논문집
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• 제12권1호
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• pp.13-22
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• 2006

Background and Aims: Herbal drugs and traditional medicines have lately attracted considerable attention by global pharmaceutical corporations because the conventional chemical drugs didn't work well for many chronic diseases or intractable diseases. The government of Korea is also supporting to develop the new drug which is high value added product, and the natural medicine including herbal medicine(or Traditional Korean Medicine) have a significant presence in this field. non-clinical pharmacology/toxicology study and clinical trial are the two major criteria which estimate efficacy and safety for registration of new drugs. All of the pharmaceutical companies producing herbal medicine and the academic and the academic world of Tradition Korean Medicine have the will to develop new herbal drugs, but there are obstacles that they have neither experience nor guideline about clinical trial. Therefore for developing new herbal drugs, it is necessary to research the present conditions and comprehensive systems about clinical trial in Northeast Asian countries China, Taiwan and Japan because they have the common background with Korea in traditional medicine fields. Methods : The present state of clinical trial for herbal medicine in Korea was investigated. And then, those in China, Taiwan, Japan was also investigated. Results and conclusions : There are significant differences among 4 Southeast Asian countries Korea, China, Taiwan and Japan each in present condition, purpose, involved comprehensive system including legislation, and actual operation of clinical trial for traditional medicine.

• 대한환경공학회지
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• 제31권7호
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• pp.499-504
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• 2009

Erythrosine은 식용색소와 염료로 사용되지만 독성 때문에 미국에서는 거의 사용되지 않는 물질이다. 본 연구에서는 입상활성탄에 의한 erythrosine의 흡착특성을 회분식 및 흡착칼럼실험을 통하여 조사하였다. erythrosine에 대한 활성탄의 흡착능은 pH조절에 의해 크게 개선되었으며 pH 11에서 초기농도 1,000 mg/L의 98%를 제거할 수 있었다. 회분식흡착실험을 통해 흡착등온선을 구한 결과 erythrosine의 평형흡착관계는 10~1,000 mg/L의 농도범위에서 Freundlich식이 잘 적용되었다. 고정층 실험을 통하여 얻은 파과곡선으로부터 초기유입농도, 유입속도, 충전층의 높이가 흡착탑 운전에 중요한 설계변수가 될 수 있음을 알았다.

• 정보화연구
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• 제11권2호
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• pp.157-173
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• 2014

기지방어, 대공방어 그리고 화생방방호 모델은 공군의 지상 작전 모델로써 참가 노드간 음성통신 중심의 체계로 설계되어 있어 정확한 의사전달에 문제가 있다. 이러한 문제를 해결하기 위해 최근 국방 분야에서는 데이터통신 기술을 이용하여 지휘통제 능력을 향상시키고 있다. 본 논문에서는 데이터통신에 기반한 차세대 기지방어작전 모델을 통해 기지방어 임무 성능향상을 극대화할 수 있는 새로운 모델을 제안한다. 현재까지 연구된 논문을 참고하여 새로운 모델을 개발하였고, 제안한 기지방어작전 모델을 비행기지내에 기존 정비통제용으로 구축되어 있던 와이브로 네트워크상에서 적용하여 실제실험을 하였다. 새로운 기지방어작전 모델의 분석 및 실험 결과 본 논문에서 제안한 모델이 성능개선에 효과가 있다는 결론에 도달한다.

• 보존과학연구
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• 통권23호
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• pp.41-57
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• 2002

It has been proved that pollutants stuck on the surface of stone architecture have significant direct and indirect harmful effects on them. Among them some do not look evidently harmful, but they have potentials to ruin stone architecture as time goes on. Since the cultural assets have magnificent meanings as historical aspects, their future states should be considered seriously as well as that of the presence. The past method to get rid of the pollutants from the surface of cultural properties has been changed a lot till the present along with scientific development of technology on this field. Existing method to eliminating pollutants are based on physical and chemical processing, which can make damages on them too. Recently cleansing using LASER has been developed in Europe and proved as effective and relatively less harmful to remove pollutants, and it has been adopted widely. After the success of the way by LASER, there are several trials to adopt the way to our cultural properties which have similar materials. Those showed satisfactory results and studies for developing the securer and more dependable ways to apply. From now on the report will show the effective ways to apply the method using LASER on to the similar materials and different materials as well and discuss about the pros and cons about the method.

• 폴리머
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• 제37권6호
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• pp.717-721
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• 2013

실크 피브로인과 poly(vinyl alcohol)(PVA)는 뛰어난 생체적합성과 수용성을 가져 생체의학 분야에서 주목하는 재료이다. 본 연구에서는 실크 피브로인과 PVA를 초음파와 동결/융해 방법으로 드레싱제로서 사용 가능한 하이드로젤을 제조하고자 하였다. 실크와 PVA를 100/0, 75/25, 50/50, 25/75, 0/100 비율로 혼합하였다. 제작한 하이드로젤을 FE-SEM, TGA, FTIR, 압축 강도 측정 등을 통해 물성을 분석하였다. 실크/PVA 하이드로젤은 PVA 함량이 증가할수록 공극 크기와 팽윤도는 감소하였으며, 젤의 강도는 증가하였다. PVA를 첨가함으로써 실크의 기계적 물성이 향상되는 것을 확인하였다. 본 연구에서 제조된 실크/PVA 하이드로젤은 드레싱제로서 사용 가능성을 제시하였다.

• 상하수도학회지
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• 제25권1호
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• pp.1-5
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• 2011

Arsenic is one of the most abundant contaminant found in waste mine tailings and soil around refinery, Because of its carcinogenic property, the countries like United States of America and Europe have made stringent regulations which govern the concentration of arsenic in soil. The study focuses on solidification/stabilization for removal of arsenic from soil. Cement was used to solidify/stabilize the abandoned soil primarily contaminated with arsenic (up to 68.92 mg/kg) in and around refinery. Solidified/stabilized (s/s) forms in the range of cement contents 5-30 wt % were evaluated to determine the optimal binder content. Revised Korean standard leaching tests (KSLT), toxicity characteristic leaching procedures (TCLP), Old Korea standard leaching test and revised Korea standard leaching test were used for chemical characterization of the S/S forms. The addition of 10 % cement remarkably reduced the leachability of arsenic in contaminated soil. The concentration of As in leachate of TCLP, KSLT, and old KSLT for soil are below the standard. However that in leachate of revised KSLT is above the standard. Because of extraction fluid used in revised KSLT is very strong acid. It is arsenic in s/s with binder should be exhaustingly leached. Therefore S/S process would not be available for As treatment in soil in Korea.