• Environmental Engineering Research
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• 제17권4호
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• pp.191-196
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• 2012

Analysis of hydrological safety as well as the determination of many substance concentrations are necessary when bioreactor systems are introduced to landfill operations. Therefore, hydrological and substance balance model was developed since it can be applied to various bioreactor landfill operation systems. For the final evaluation of the model's effectiveness, four different methods of injections (leachate alone, leachate and organic waste water, leachate and reverse osmosis concentrate, and all the above three combination) was applied to 1st landfill site of Sudokwon landfill. As a result, the water content of the hypothetical cases for four different systematic bioreactors is projected to be increased up to 35.5% in next 10 years, and this indicated that there will be no problems in meeting the hydrological safety. Also, the final $Cl^-$ concentration after 10-yr time period was projected to be between from minimum 126 to maximum 3,238 mg/L, which could be still a decrease from the original value of 3,278 mg/L. According to the proposed model, whether the substance concentration becomes increased or decreased largely depends on the ratio of initial quantity of inner landfill leachate and the rate of injection.

• 약학회지
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• 제49권6호
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• pp.495-504
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• 2005

In our study, osteoporosis was induced by ovariectomized in female Sprague-Daweley rats, and the prevention and treatment efficacy of the climacteric disease the postmenopausal Type I pattern was examined by using the experimental substance soybeans and arrowroot. After ovariectomy; the amount of estrogen was found to be reduced by 21.37$\%$ and it showed the tendency to be increased by 4.49$\%$ in T1 (extraction of soybeans group) and 7.62$\%$ in T2 (extraction of ferment soybeans group). The change of bone density, 14 weeks after ovariectomy in the femur, was decreased by 9.33$\%$ in N.C. group, and 5.46$\%$ in T3 (extraction of ferment arrowroot group). As pathological findings, the trabeculae of femur were detected to be abundant as normal and the frequency of the appearance of osteoclasts was very minimal. In the T3, the frequency of the appearance of the trabeculae of femur was increased to the level that could be distinguished. In regard to the accumulation of lipid in the bone marrow, the accumulation of lipid in the bone marrow was low as normal. However, in T3, the decrease to the level that could be distinguished was detected. In addition, in regard to the pathological findings of the uterus, normal uterine tissue findings were detected. In the T3, the minimal atrophy findings were detected. In conclusion, when the T3 was orally administered continuously for 14 weeks, it was thought that a certain proportion of the hormonal balance was maintained that functioned as a substance interfering the accumulation of fat, and it was considered to be of help in the treatment of not only osteoporosis Type I, but also for the prevention and treatment of various endocrinal diseases.

• 대한화학회지
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• 제18권2호
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• pp.138-142
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• 1974

透析係數가 常數로 나타날 수 있는 條件究明으로서 透析質의 種類에 따르는 外部內의 畜積限界量을 究明하였고, 한편 透析係數와 透析溫度사이의 相關關係를 아울러 究明하였다.

• 한국약용작물학회지
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• 제23권3호
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• pp.245-252
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• 2015

This study was carried out to investigate the effects of Salvia plebeia R. Br. ethanolic extract with different aspects (stem/leaf and whole plant) on differentiation and lipid accumulation in 3T3-L1 preadipocytes. The morphological changes and the degrees of lipid accumulation in 3T3-L1 cells were measured by Oil Red O staining and intra-cellular triglyceride (TG) assay. The mRNA expressions of special peroxisome proliferation activated receptor- genes (PPAR), CCAAT/ enhancer-binding protein (C/$EBP{\alpha}$), fatty acid synthase (FAS) and lipoprotein lipase (LPL) were detected by reverse transcriptase polymerase chain reaction (RT-PCR). The 50% ethanolic extracts ($100{\mu}g/mL$) of stem and leaf (SALE) and 30% ethanolic extracts (100 g/mL) of whole plant (SAE) from Salvia plebeia R. Br. were significantly attenuated lipid accumulation during adipogenesis in 3T3-L1 cells. Ethyl acetate-soluble fractions ($50{\mu}g/mL$) significantly inhibited lipid droplet accumulation in 3T3-L1 cells. In addition, SALE induced down-regulation of specific adipogenic transcriptional factors (C/$EBP{\alpha}$ and $PPAR{\gamma}$) and target genes (FAS and LPL) during adipogenesis. Salvia plebeia R. Br. may be used as a safe and efficient natural substance to manage obesity.

• 동아시아식생활학회지
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• 제11권1호
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• pp.1-10
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• 2001

Since the Industrial Revolution, people have enjoyed an abundant life, owing to the technological innovations of science. However, because of changes in the environment or polution to the environment, it has brought on many chronic diseases. Especially, even though it may be a small amount, if cadmium gets into a human body, because its biological half life is long, it fatally causes a kidney disease and damage to human organisms. It was reported that Metallothioneins(MT), a substance that is closely related with a free radical that comes from environmental pollution and the course of which cadmium, which causes chronic addition in the body, is formed, along with harmful metals, make the toxicity reduce. MT compound led into the body by cadmium indirectly functions as an antioxidation, supplied adequate amount of vitamin E, and suppresses the accumulation of cadmium in heart, liver and blood. Cadmium content found in Korean soil according to the test conducted from 1992 to 1996 was 0.02~0.03mg/kg in cereals, pulses, and potatoes. Free radical scavenger, finding solution for metal substance that comes from environmental pollution from food and natural substances implicates a better future for the study of food science.

• Journal of Microbiology and Biotechnology
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• 제33권3호
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• pp.310-318
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• 2023

Microalgae are attracting much attention as promising, eco-friendly producers of bioenergy due to their fast growth, absorption of carbon dioxide from the atmosphere, and production capacity in wastewater and salt water. However, microalgae can only accumulate large quantities of lipid in abiotic stress, which reduces productivity by decreasing cell growth. In this study, the strategy was investigated to increase cell viability and lipid production by overexpressing S-adenosylmethionine (SAM) synthetase (SAMS) in the microalga Chlamydomonas reinhardtii. SAM is a substance that plays an important role in various intracellular biochemical reactions, such as cell proliferation and stress response, and the overexpression of SAMS could allow cells to ithstand the abiotic stress and increase productivity. Compared to wild-type C. reinhardtii, recombinant cells overexpressing SAMS grew 1.56-fold faster and produced 1.51-fold more lipids in a nitrogen-depleted medium. Furthermore, under saline-stress conditions, the survival rate and lipid accumulation were 1.56 and 2.04 times higher in the SAMS-overexpressing strain, respectively. These results suggest that the overexpression of SAMS in recombinant C. reinhardtii has high potential in the industrial-scale production of biofuels and various other high-value-added materials.

• Journal of Microbiology and Biotechnology
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• 제20권1호
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• pp.71-77
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• 2010

The time, yield, and related genes expression of PHB accumulation of Acidiphilium cryptum DX1-1 were investigated under four different initial C/N ratios, 1.2, 2.4, 7.5, and 24. The results of time and yield of poly-$\beta$-hydroxybutyrate (PHB) accumulation show that the initial C/N ratio of 2.4 was optimum for strain DX1-1 to accumulate PHB, but both higher and lower initial C/N ratios did not favor that process. Based on the genome of Acidiphilium cryptum JF-5, 13 PHB accumulation related genes in strain JF-5 were chosen and successfully cloned from strain DX1-1. The differential expressions of the 13 functional genes, in different C/N ratios as cited above, were then studied by real-time PCR. The results show that all the 13 genes were most upregulated when the initial C/N ratio was 2.4, and among which the gene Acry_3030 encoding poly-$\beta$-hydroxybutyrate polymerase and Aery_0626 encoding acetyl-CoA synthetase were much more upregulated than the other genes, which proved that they play the most important role for PHB accumulation, and acetate is the main initial substance for PHB accumulation for strain DX1-1. Potential regulatory motifs analysis showed that the genes related to PHB accumulation are regulated by different promoters and that the motif had weak similarity to the model promoters, suggesting that PHB metabolism in Acidiphilium cryptum may be mediated by a different mechanism.

• 대한치과의사협회지
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• 제56권10호
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• pp.572-580
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• 2018

Adequate access cavity is the key to achieving endodontic success. The aims of the access cavity can be considered as follows: 1) Creation of a smooth unimpeded pathway for instruments to canal orifices 2) Removal of the entire roof of the pulp chamber in order to inspect the pulp floor, 3) Preservation of natural tooth substance consistent with the above. Recently, contracted endodontic cavities based on minimally invasive endodontics has introduced. This has the benefit of preserving the pericervical dentin more than traditional access cavity with achieving long-term success. However, some studies reported controversial results regarding root canal detection, instrumentation efficacy (noninstrumented canal area, hard tissue debris accumulation, canal transportation, and centering ratio) as well as fracture resistance. Therefore, further studies are required for accepting contracted access cavity, and modified form of traditional and contracted access cavity could be considered.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1997년도 제26회 추계학술대회
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• pp.66-75
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• 1997

This study was undertaken to investigate tribology characteristics of the alumina ceramics($Al_2O_3$) of the various purity for the variation of ambient condition such as air and vacuum. The wear test was carried out under different experimental condition using the wear test device, which was designed for this study, and in which the annular surface of wear testing specimens as well as mate specimen made of STB2 steel, were subjected to sliding speed, applied load and the sliding distance. The results obtained were as follows. As the ambient pressure decreases, the friction coefficient increases because the protective layer made of absorption due to decrease of the amount of ambient gas can not be formed. As the friction coefficient paticularly for 85% alumina lower than 95% and 99.7% in the alumina purity increases by an influence of heat accumulation caused by small elastic modulus and thermal conductivity. The friction surface of ceramics can be protected in the air by the influence of the oxides transfered from STB2. However, in the vacuum, the protective layer made of the absorption substance can not be formed due to the decrease of ambient gas.

• 한국작물학회지
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• 제45권1호
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• pp.32-37
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• 2000

The in vitro culture of rice panicles is a culturing technique only panicle without other organs in culture solution containing organic substance, so that would be useful to study how assimilate supply affects grain development and maturation. To find the optimum stage for in vitro culture, rice panicles grown in greenhouse were sampled periodically after anthesis and cultured in nutrient medium. The panicles older than 1 weeks after anthesis had produced normal grains. Grain-filling was apparently dependent upon sucrose concentration (8-12 %) in medium, but not affected by nitrogen concentration supplied with glutamine. As far as rice panicle was supplied with sucrose and N in nutrient medium, grains continued accumulation of dry matter and maturation regardless to light condition. Considerably, grain-filling was improved when panicles were positioned horizontally inside flask, so that each grain was partially submerged to nutrient medium.