• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.28 no.5
• /
• pp.364-371
• /
• 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.

• Korean Journal of Agricultural Science
• /
• v.47 no.2
• /
• pp.361-373
• /
• 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.

• Proceedings of the Korean Vacuum Society Conference
• /
• 1995.06a
• /
• pp.154-154
• /
• 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
• /
• v.2 no.5
• /
• pp.65-71
• /
• 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.

• Korean Journal of Oriental Medicine
• /
• v.12 no.1
• /
• pp.13-22
• /
• 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.

• Journal of Korean Society of Environmental Engineers
• /
• v.31 no.7
• /
• pp.499-504
• /
• 2009

Erythrosine is used a food coloring, ink and dye, etc. but erithrosine is rarely used in United States due to its known hazards. The adsorption characteristics of erythrosine by granular activated carbon were investigated in the batch adsorber and the packed column. The adsorptivity of activated carbon for erythrosine were largely improved by pH control. When the pH was 11 in the sample, the erythrosine could be removed 98% of initial concentration. It was estabilished that the adsorption equilibrium of erythrosine on granular activated carbon was successfully fitted by Freundlich isotherm equation in the concentration range from 10mg/L to 1,000mg/L. The characteristics of breakthrough curve of activated carbon packed column depend on the design variables such as initial concentration, bed height, and flow rate.

• Journal of Information Technology and Architecture
• /
• v.11 no.2
• /
• pp.157-173
• /
• 2014

As Air Base Defence, Anti-Aircraft Defence and Nuclear-Biological-Chemical Protection model considered as ground operation models in Republic of Korea Air Force are designed as the voice-centered system between participant nodes, there is a problem communicating accurately. In recent years, the military is developing a command and control capability using data communication technology to solve the problem. Therefore, this paper proposes new model to maximize efficiency of performance improvement through the Data Communication-based Future Air Base Defence Model. We refer to a research paper that is related existing and developed new model. and then we really experimented under WiBro Network that is constructed to Air Base for maintenance control. Based on the analysis and the test result of new Air Base Defence Model, we have concluded that the performance improvement effect is reached.

• 보존과학연구
• /
• s.23
• /
• pp.41-57
• /
• 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.

• Polymer(Korea)
• /
• v.37 no.6
• /
• pp.717-721
• /
• 2013

Biomaterials like silk fibroin (SF) and poly(vinyl alcohol) (PVA) have received increasing attention in biomedical applications because of their attractive properties such as hydrophobicity and biocompatibility. In this study, efficient systems consisting of interpenetrating SF/PVA hydrogels were prepared as potential candidate for wound dressing applications. A simple approach consisting of sonication and a freezing-thawing technique was adopted to fabricate the hydrogels. Different blend ratios consisting of SF (100, 75, 50, 25 and 0%) with respect to the weight of PVA were prepared. The produced hydrogels were characterized for physico-chemical investigations using various states of techniques like; FE-SEM, TGA, FTIR and tensile strength. The addition of PVA to SF was proved to be beneficial in terms of reducing the pore size and swelling ratio of hydrogels. The mechanical property of SF had been increased by addition of PVA. These results show that SF/PVA hydrogels may serve as potential candidates for wound dressing application.

• Journal of Korean Society of Water and Wastewater
• /
• v.25 no.1
• /
• pp.1-5
• /
• 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.