• Asian Pacific Journal of Cancer Prevention
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• v.15 no.17
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• pp.7395-7399
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• 2014

Background: Persistent human papillomavirus (HPV) infection, especially with high-risk types such as HPV16 and HPV18, has been identified as the primary cause of cervical cancer. E6 and E7 are the major onco-proteins of high-risk HPVs, which are consistently expressed in HPV infected tissues but absent in normal tissues and represent ideal therapeutic targets for immunotherapy of cervical cancer. Materials and Methods: In this study, the optimized fusion gene HPV18 E6E7 (HPV18 ofE6E7) was constructed according to genetic codon usage for human genes. At the same time, for safety future clinical application, a mutant of HPV18 ofE6E7 fusion gene was generated by site-directed mutagenesis at L52G for the E6 protein and C98G for the E7 protein. Results: HPV18-E6E7 mutant (HPV18 ofmE6E7) constructed in this work not only lost the transformation capability for NIH 3T3 cells and tumorigenicity in BALB/c nude mice, but also maintained very good stability and antigenicity. Conclusion: These results suggest that the mutant should undergo further study for application as a safe antigenspecific therapeutic vaccine for HPV18-associated tumors.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.1
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• pp.9-21
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• 2015

Cancer, a serious public health problem in worldwide, results from an excessive and uncontrolled proliferation of the body cells without obvious physiological demands of organs. The gastrointestinal tract, including the esophagus, stomach and intestine, is a unique organ system. It has the highest cancer incidence and cancer-related mortality in the body and is influenceed by both genetic and environmental factors. Among the various chemical elements recognized in the nature, some of them including zinc, iron, cobalt, and copper have essential roles in the various biochemical and physiological processes, but only at low levels and others such as cadmium, lead, mercury, arsenic, and nickel are considered as threats for human health especially with chronic exposure at high levels. Cadmium, an environment contaminant, cannot be destroyed in nature. Through impairment of vitamin D metabolism in the kidney it causes nephrotoxicity and subsequently bone metabolism impairment and fragility. The major mechanisms involved in cadmium carcinogenesis could be related to the suppression of gene expression, inhibition of DNA damage repair, inhibition of apoptosis, and induction of oxidative stress. In addition, cadmium may act through aberrant DNA methylation. Cadmium affects multiple cellular processes, including signal transduction pathways, cell proliferation, differentiation, and apoptosis. Down-regulation of methyltransferases enzymes and reduction of DNA methylation have been stated as epigenetic effects of cadmium. Furthermore, increasing intracellular free calcium ion levels induces neuronal apoptosis in addition to other deleterious influence on the stability of the genome.

• Journal of the Korean Institute of Intelligent Systems
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• v.23 no.5
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• pp.479-486
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• 2013

There exist two major difficulties in developing flight control system: nonlinear dynamic characteristics and time-varying properties of parameters of aircraft. Instead of the difficulties, many high reliable and efficient control methodologies have been developed. But, most of the developed control systems are based on the exact mathematical modelling of aircraft and, in the absence of such a model, it is very difficult to derive performance, robustness and nominal stability. From these aspects, recently, some approaches to utilizing the intelligent control theories such as fuzzy logic control, neural network and genetic algorithm have appeared. In this paper, one advanced intelligent lateral control system of a high speed fight has been developed utilizing type-2 fuzzy logic, which can deduce the uncertainty problem of the conventional fuzzy logic. The results will be verified through computer simulation.

• Journal of Power Electronics
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• v.13 no.4
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• pp.679-691
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• 2013

High-power electromagnetic transmitter power supplies are an important part of deep geophysical exploration equipment. This is especially true in complex environments, where the ability to produce a highly accurate and stable output and safety through redundancy have become the key issues in the design of high-power electromagnetic transmitter power supplies. To solve these issues, a high-frequency switching power cascade based emission power supply is designed. By combining the circuit averaged model and the equivalent controlled source method, a modular mathematical model is established with the on-state loss and transformer induction loss being taken into account. A triple-loop control including an inner current loop, an outer voltage loop and a load current forward feedback, and a digitalized voltage/current sharing control method are proposed for the realization of the rapid, stable and highly accurate output of the system. By using a new algorithm referred to as GAPSO, which integrates a genetic algorithm and a particle swarm algorithm, the parameters of the controller are tuned. A multi-module cascade helps to achieve system redundancy. A simulation analysis of the open-loop system proves the accuracy of the established system and provides a better reflection of the characteristics of the power supply. A parameter tuning simulation proves the effectiveness of the GAPSO algorithm. A closed-loop simulation of the system and field geological exploration experiments demonstrate the effectiveness of the control method. This ensures both the system's excellent stability and the output's accuracy. It also ensures the accuracy of the established mathematical model as well as its ability to meet the requirements of practical field deep exploration.

• Microbiology and Biotechnology Letters
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• v.14 no.3
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• pp.213-218
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• 1986

Hybrid plasmid pEA24, shuttle vector YRp7 carrying amylase gene of Bacillus amyloliquefaciens, was transformed to yeast Saccharomyces cerevisiae, and the expression of B. amyloliquefaciens amylase gene in yeast was investigated. The frequency of transformation to S. cerevisiae DBY747 with YRp7 was increased by treatment of 40% polyethylene glycol (MW 4, 000), PH 7.0, at 3$0^{\circ}C$, and by regeneration used 2% top agar. The amount of cellular amylase activity produced by S. cerevisiae containing pEA24 was 2% of that secreted from B. amyloliquefaciens, but in case of S. cerevisiae transformant, the amylase secreted was not detected. A comparison of genetic stability of pEA24 and YRp7 plasmids in yeast was carried out by cultivation of transformants in tryptophan-supplement-medium. The pEA24 plasmid was more unstable than YRp7 in S. cerevisiae. The size of pEA24 extracted from S. cerevisiae transformants was found to be identical with that from E. coli transformants by agarose gel electrophoresis.

• Applied Biological Chemistry
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• v.31 no.3
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• pp.274-283
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• 1988

Aqualysin I is an alkaline serine protease which is secretet into the culture medium by Thermus aquaticus YT-1, an extreme thermophile. Aqualysin I was purified, and its partial amino acid sequence was determined. The gene encoding aqualysin I was cloned into E. coli using synthetic oligodeoxyribonucleotides as hybridization probes. The nucleotide sequence of the cloned DNA was determined. The primary structure of aqualysin I, deduced from the nucleotide sequenc, agreed with the determid amino acid sequences, including the $NH_2-$ and COOH terminal sequence of the tryptides derived from aqualysin I. Aqualysin I comprised 281 amino acid residues and its molecular mass was determined to be 28350. On alignment of the whole amino acid sequence, aqualysin I showed high sequence homology with the subtilisin type serine protease, and 43% identity with proteinase K, 37-30% with subtilisins and 34% with thermitase. Extremely high sequence identity was observed in the regions containing the active-site residues, corresponding to Asp32, His64 and Ser221 of subtilisin BPN'. Aqualysin I contains two disulfide bonds, Cys67-Cys99 and Cys163-Cys194, and these disulfide bonds seem to contribute to the heat stability of the enzyme. The determined positions of the twe disulfide bonds of aqualysin I agreed with those predicted previously on the basis of computer graphics of the crystallographic data for subtilisin BPN'. Therefore, these findings sugests that the three-dimensional structure of aqualysin I is similar to that of subtilisin BPN' Aqualysin I is produced as a lage precursor, which contains $NH_2-$ and COOH- terminal portions besides the mature protease sequence.

• Korean Journal of Agricultural and Forest Meteorology
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• v.3 no.4
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• pp.220-237
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• 2001

Over the 20th century global temperature increase has been 0.6$^{\circ}C$. The globally averaged surface temperature is projected to increase by 1.4 to 5.8$^{\circ}C$ over the period 1990 to 2100. Nearly all land areas will have higher maximum temperature and minimum temperature, and fewer cold days and frost days. More intense precipitation events will take plate over many areas. Over most mid-latitude continental interiors will have increased summer continental drying and associated risk of drought. By 2100, if the annual surface temperature increase is 3.5$^{\circ}C$, we will have 15.9$^{\circ}C$ from 12.4$^{\circ}C$ at present. Also the annual precipitation will range 1,118-2,447 mm from 972-1,841 mm at present in Korea. Consequently the average crop periods for summer crops will be 250 days that prolonged 32 days than at present. In the case of gradual increase of global warming, an annual crop can be adapted to the changing climate through the selection of filial generations in breeding process. The perennial crops such as an apple should be shifted the chief producing place to northern or high latitude areas where below 13.5$^{\circ}C$ of the annual surface temperature. If global warming happens suddenly over the threshold atmospheric greenhouse gases, then all ecosystems will have tremendous disturbance. Agricultural land-use plan, which state that farmers decide what to plant, based on their climate-based advantages. Therefore, farmers will mitigate possible negative imparts associated with the climate change. The farmers will have application to use agricultural meteorological information system, and agricultural long-range weather forecast system for their agroecosystems management. The ideal types of crops under $CO_2$ increase and climate change conditions are considered that ecological characteristics need indispensable to accomplish the sustainable agriculture as the diversification of genetic resources from yield-oriented to biomass-oriented characteristics with higher potential of $CO_2$ absorption and primary production. In addition, a heat-and-cold tolerance, a pest resistance, an environmental adaptability, and production stability should be also incorporated collectively into integrated agroecosystem.

• Korean Journal of Animal Reproduction
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• v.25 no.2
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• pp.171-180
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• 2001

Compared to other gene transfer system, the advantages of retrovirus-mediated gene transfer are technical ease, efficient expression and genetic stability. Despite the high potency of the retrovirus vector system in gene transfer, one of the drawbacks is a difficulty in concentration of virus stock. To overcome this problem, we tested a new retrovirus vector system producing the progeny retrovirus particles encapsidated with VSV-G (vesicular stomatitis virus G glycoprotein). The infectivity of this virus was not sacrificed by ultracentrifugal concentration and the host cell range extended from all mammalian to fish embryos. Virus titer after 1,000 x concentration was more than 10$^{8}$ CFU/ $m\ell$ on most of the target cell lines. We applied this pantropic viruses in transgenic chicken production by injecting the concentrated (100$\times$) stock into subgerminal cavity of stage X chicken embryos. The survival rate of chicken embryos after injection was about 20% and gene integration rate in surviving embryos was scored almost 100%. Analyses of RT-PCR and fluorescence microscopy, however, showed no evidence of the transgene expression.

• Economic and Environmental Geology
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• v.25 no.1
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• pp.41-50
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• 1992

Mineral assemblages, mineral chemistries and stable isotope compositions of altered rocks of the Ogmae, Seongsan, Haenam and Gusi mines near the Haenam volcanic field in the southwestern part of the Korea peninsula were studied. Characteristic hydrothermal alteration zones in these deposits occurring in the Cretaceous volcanics and volcanogenic sediments, acidic tuff, and rhyolite, were outlined. Genetic environment with particular reference to the spatial and temporal relationships for these deposits were considered. The alteration zones defined by a mineral assemblage in the Ogmae and Seongsan deposits can be classified as alunite, pyrophyllite, kaolinite or dickite, quartz, illite or illite/smectite. Alunite was not developed in the Gusi and Haenam deposits. Boundaries between the adjacent zones are always gradational except for vein-type alunite. Alteration zones are superimposed upon each other in some localities. These deposits formed $71.8{\pm}2.8{\sim}76.6{\pm}2.9$ Ma ago, which is the almost same age of later volcanic rocks $79.4{\pm}1.7{\sim}82.8{\pm}1.2$ Ma, the Haenam Group, corresponding to Campanian. It indicates that hydrothermal alteration of these deposits appeared to be related to felsic volcanism in the area. Consideration of the stability between kaolinite, alunite, pyrite and pyrophyllite, and the geothermometry based on the mineral chemistry of illite and chlorite suggests that the maximum formation temperature for alunite and pyrophyllite can be estimated at about $250^{\circ}C$ and $240{\sim}290^{\circ}C$, respectively. It also suggests that these deposits were formed by acidic sulfate solution with high aqueous silica and potassium activity in a shallow depth environment. Compositional variation of alunite also suggests that the physico-chemical conditions fluctulated considerably during alteration processes, indicating shallow depth environment. The Haenam deposit was formed at a relatively greater depth than the others. The sulfur isotope composition of alunite and pyrite indicates that sulfur probably had a magmatic source, and the oxygen isotope composition for kaolinite indicates that the magmatic hydrothermal solution was diluted by circulating meteoric water.

• Korean Journal of Microbiology
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• v.38 no.2
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• pp.96-102
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• 2002

The S-phase checkpoint mechanisms response to DNA damage or inhibition of DNA replication for maintenance of genetic stability in eukaryotic cells. These roles include cell cycle control arrest at S-phase and Iranscriptional induction of repair genes. To characterize the defects of dpbll mutant for both these responses, we examined the over-expression effect of DPBll gene, the sensitivity to HU, MMS, and the transcriptional pattern by DNA damage agent for RNRS mRNA. RNRS transcript is induced in response to a wide variety of agents that either damage D7A directly through chemical modification or induce stress by blocking DNA synthesis. As results, dpbll-1 cells are sensitive to DNA damage agents and the level of RNR3 mRNA is reduced approximately 40% than wild type cells. Moreover, we found the same results in dpb2-1 cells. Therefore, we propose that DPB2 and DPBll act as a sensor of replication that coordinates the transcriptional and cell cycle responses to replication blocks.