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        검색결과 31

        1.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A study on indigenous diatoms was carried out at 10 sites from May 2014 to December 2016 in marine and freshwater in Korea. Seventeen species of diatoms are new to Korea and they are divided into 3 classes, 4 subclasses, 10 orders, 14 families, and 16 genera. The nomenclatures, references, dimensions, specimens examined, local habitat, distribution in Korea, and photograph are reported here. Seventeen species found in marine, freshwater, and brackish water showed species-specific habitats.
        4,300원
        3.
        2017.03 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        Programmed cell death (PCD) is decisive in eliminating affected cells in human cancers, whereas there are increasing cases of cancer-related death due to side effects of modern treatment methods. There is an urge for new methods of growth inhibition and elimination of cancer cells with a lower cytotoxicity to normal cells. Irregularity along PCD pathways plays a crucial role in cancer cell carcinogenesis. Apoptosis is a distinct cell death mechanism occurring in multicellular organisms and also called type one programmed cell death. Autophagy and paraptosis are non-apoptotic PCD occurring in multicellular organisms. Natural compounds are the fundament of pharmacological treatments, and flavonoids are natural polyphenolic compounds which are unique due to their diverse chemical structures and various biological active mechanisms like anticancer, anti-inflammatory, antioxidative and much more. This gives an increasing number of studies indicating that some flavonoids from medicinal plants could be promising candidates for new natural anticancer drugs, which attract high interests of academic researchers and advanced users. An understanding of the underlying mechanism of PCD induced by flavonoids in cancer cells is important as it plays a pivotal role in the pathogenesis of many diseases. This systematic review is to report flavonoids and their derivatives as new anticancer candidates to stimulate PCD with a different mechanism based on the pharmacological evidence.
        4,000원
        4.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this paper, we propose a method for replaying game streaming video using informations of input-key and object states. Up to the present, the played game contents have been just recorded and replayed for game streaming video recording function provided by the game company, this required a large volume of storage device. By the proposed method, it is more efficient for sharing the game informations between the users and game companies, and between the users and other users because it need much less storage device than the present method. And also the game user can handle the additional game informations.
        4,000원
        5.
        2005.10 KCI 등재 구독 인증기관·개인회원 무료
        Hemangiomas are different from true vascular malformations in thei l‘ pathogenesis and cl inical prognosis. There are sti ll no standardized antibodies to distinguish hemangioma and vascular malformation apparently. We compared juvenile hemangioma and vascular malformation with immunohistochemjstry using va ri OllS antibodies, i.e. , ANG, bFGF, VEGF. EGFR, vWF. PCNA. p53. maspin, and TNF- . A very st rong positive expression of ANG and vWF was observed mainly in the vascular endothelial cells of juvenile hemangioma. VEGF s howed st rong positive reaction in the juveni le hemangioma, but p53 showed no positive reaction. Ancl a strong positive reaction of ANG was observed in the vascular endothelial walls of vascular malformation. p53 was frequently positive in the lining endothel ial cells in the vascular malformatJOn Using a ntiboclies such as VEG F'. ANG. vWF which a re related to the proliferation and matllrity of the vessel components. and p53 antibodies in order to confirm between juvenile hemangioma and vascular malformation would be helpful
        6.
        2002.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        학령전 아동의 zinc absorption, excretion, balance에 대하여 연구한 결과는 다음과 같다. Zinc absorption은 남자아동의 경우 29.7%, 여자 아동의 경우 23.3%, 평균 25.8%로 나타났다. 대상자의 zinc absorption은 zinc intake와는 상관성이 나타나지 않았으며, zinc balance와 유의적 상관 (p<0.01)을 보였다. Zinc balance는 남자 아동의 경우 평균 3.25mg/day, 여자 아동의 경우 1.78mg/day, 평균 2.34mg/day로 1명의 대상자를 제외하고 모두 positive balance를 보였다. Fecal zinc loss는 평균 6.31mg/day, nary zinc loss는 평균 0.16mg/day였다. zinc intake는 fecal zinc loss및 zinc balance에 유의적 영향을 미치는 것으로 나타났으며 (p<0.01), urinary zinc는 intake의 영향을 받지 않았다. 우리나라 학령전 아동의 zinc absorption 및 balance, 는 양호한 것으로 나타났다. 그러나 이 방면의 연구 자료가 많지 않아, 성장기 아동을 대상으로 한 zinc nutrition에 대한 구체적이고 지속적인 연구가 필요하다.
        4,000원
        9.
        1998.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We have made semi-analytical studies to investigate the configurations of caustics and the probability distribution of the flux factor K for the binary microlensing including external shears. A parametric equation of critical curve is derived in a 4th order complex polynomial. We present the topological dependencies of the caustics for selected gamma parameters (0, 0.3, 0.6, 1.3, 2.0, and 2.5) and convergence terms (0., 0.4, 0.8, 1.2, 1.6, and 2.0). For the purpose of analyzing the efficiency of High Amplification Event (HAE) on each caustics, we examine the probability distribution of the flux factor by a Monte Carlo method. Changing the separation of the binary system from 0.8 to 1.3 (in normalied unit), we examine the probability distribution of the K-values in various gamma parameters. The relationship between gamma parameters, seperations and their probabilties of the flux factor K have been studied. Our results show that the relatively higher K values (K>1.5) are increased as increasing the separation of the binary system. We therfore conclude that, in the N-body microlensing, the probabilities of higher HAEs are inversely proportional to the star density as well. We also point out that the present research might be used as a preliminary step toward investigating heavy N-body microlensing simulations.
        4,200원
        10.
        1997.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        토양으로부터 분리한 120 여종의 집락 중 응집제를 생산하는 집락을 선발하고 가장 응집력이 우수한 K-67 균주를 최종 선발하여 Agrobacterium sp KF-67로 동정하고 실험균주로 사용하였다. 응집제 생산시 최적 배지성분을 조사하기 위하여 응집활성을 kaolin과 활성탄현탁액에서 응집활성을 측정하였다. 최적 배지성분과 농도는 탄소원과 무기질소원은 glucose와 NH_4NO_3 각각 2%와 0.1%, 유기질소원은 yeast extract와 peptone 각 0.01%, 무기염으로 CaCO_3을 0.04%를 첨가하였을 때 응집활성이 가장 우수하였다. 배지 중 0.03% NaCl 첨가로 약 19%의 응집활성을 향상시킬 수 있었다. 이상과 같은 결과로 볼 때 Agrobacterium sp.에 의한 응집제 생산시 최적배지의 성분 조성과 함량은 2% glucose, 0.1% NH_4NO_3 0.01% yeast extract, 0.01% peptone, 0.04% CaCO_3, 0.03% NaCl이었고, 이때 기초배지에 비해 약 76.1%의 응집활성력이 증가하여 응집제 생산에 효과적인 배지성분 조건으로 조사되었다.
        4,000원
        13.
        2007.12 KCI 등재 서비스 종료(열람 제한)
        The aim of this study was to isolate chicken feather-degrading bacteria with high keratinolytic activity and to investigate cultural conditions affecting keratinolytic enzyme production by a selected isolate. A chicken feather-degrading bacterial strain CH3 was isolated from poultry wastes. Isolate CH3 degraded whole chicken feather completely within 3 days. On the basis of phenotypical and 16S rDNA studies, isolate CH3 was identified as Bacillus thuringiensis CH3. This strain is the first B. thuringiensis described as a feather degrader. The bacterium grew with an optimum at pH 8.0 and 37℃, where maximum keratinolytic activity was also observed. The composition of optimal medium for keratinolytic enzyme production was feather 0.1%, sucrose 0.7%, casein 0.3%, K2HPO4 0.03%, KH2PO4 0.04%, MgCl2 0.01% and NaCl 0.05%, respectively. The keratinolytic enzyme had a pH and temperature optima 9.0 and 45℃, respectively. The keratinolytic activity was inhibited ethylenediaminetetraacetic acid, phenylmethylsulfonyl fluoride, and metal ions like Hg2+, Cu2+ and Zn2+. The enzyme activated by Fe2+, dithiothreitol and 2-mercaptoethanol.
        14.
        2007.11 KCI 등재 서비스 종료(열람 제한)
        The removal of nitrogen compounds from a wastewater is essential and it is often accomplished by biological process. An aerobic nitrate-removing bacterium was isolated from a municipal sewage treatment plant and soil. On the basis of its morphological, cultural and physiological characteristics and 16S rRNA sequencing data, this strain was identified as Pseudomonas fluorescens, and named as P. fluorescens K4. The optimal conditions of the initial pH and temperature of media for its growth were 7.0~8.0 and 30℃, respectively. P. fluorescens K4 was able to remove 99.9% of nitrate after 24 h in a culture. The strain could grow with a nitrate concentration up to 800 mg/l and was able to remove 99.9% of nitrate after 104 h of incubation. The optimal electron donor was sodium citrate for a nitrate removal. The strain K4 showed a capability of a complete nitrate removal when the initial C/N ratio was 1.0. An effect of the initial seed concentration was observed for a cell of 10% (v/v) for a nitrate removal. Especially P. fluorescens K4 could completely remove 200 mg/l ammonium for 3 days.
        15.
        2007.10 KCI 등재 서비스 종료(열람 제한)
        Feathers are produced in huge quantities as a waste product at commercial poultry processing plants. Since feathers are almost pure keratin protein, feather wastes represent an alternative to more expensive dietary ingredients for animal feedstuffs. Generally they become feather meal used as animal feed after undergoing physical and chemical treatments. These processes require significant energy and also cause environmental pollutions. Therefore, biodegradation of feather by microorganisms represents an alternative method to prevent environment contamination. The aim of this study was to investigate cultural conditions affecting keratinolytic protease production by Bacillus pumilus RS7. We also assessed the nutritive value of microbial and alkaline feather hydrolysates. The composition of optimal medium for the keratinolytic protease was fructose 0.05%, yeast extract 0.3%, NaCl 0.05%, K2HPO4 0.03%, KH2PO4 0.04% and MgCl2ㆍ6H2O 0.01%, respectively. The optimal temperature and initial pH was 30℃ and 9.0, respectively. The keratinolytic protease production under optimal condition reached a maximum after 18 h of cultivation. Total amino acid content of feather hydrolysates treated by NaOH and B. pumilius RS7 was 113.8 ㎍/ml and 504.9 ㎍/ml, respectively. Essential amino acid content of feather hydrolysates treated by NaOH and B. pumilius RS7 was 47.2 ㎍/ml and 334.0 ㎍/ml, respectively. Thus, feather hydrolysates have the potential for utilization as an ingredient in animal feed.
        16.
        2007.09 KCI 등재 서비스 종료(열람 제한)
        The aim of this study was to isolate mesophilic chicken feather-degrading bacteria and to evaluate feather hydrolysate as alternative biofertilizer. Isolate RS7 was isolated from compost and identified as Bacillus pumilus according to API analysis and 16S rDNA sequencing analysis. Chicken feathers were completely degraded after 5 days of cultivation at 30℃. Feather hydrolysate treated by B. pumilius RS7 positively influenced Helianthus sannuus L. (sunflower) growth (e.g. growth rate, number and dry weight of leave, and flowering rate). These results suggest that feather hydrolysate prepared using B. pumilius RS7 could successfully be used as alternative biofertilizer, thereby reducing the environmental impact of feather waste from the poultry industry.
        17.
        2006.12 KCI 등재 서비스 종료(열람 제한)
        To investigate the influence of the mesophyll cells on stomatal opening in response to white light, the segments of isolated epidermis were transferred on partly exposed mesophyll cells of a leaf and stomatal apertures were measured. Transferring the isolated epidermis on partly exposed mesophyll cells of a leaf caused a marked increase on stomatal apertures while stomata in isolated epidermis incubated in MES buffer hardly opened. Mesophyll infiltration with photosynthetic inhibitors (DCMU, DCCD, NaN3) was performed to elucidate the correlation between stomatal apertures and the degree of photosynthetic activity. It was found that transferring the isolated epidermis on partly exposed mesophyll cells of a leaf caused an increase of stomatal apertures depending on the degree of photosynthetic activities. In NaN3 infiltrated leaf discs, transferring the fresh isolated epidermis on partly exposed mesophyll cells of a leaf showed no significant effect, but a slight increase on stomatal apertures. Isolated epidermis alone did not respond to the light properly, but if it was closely contacted with mesophyll cells, the stomata regained the ability of the light response. Therefore, it could be suggested that stomatal apertures were related with the degree of photosynthetic activity in the mesophyll cells.
        18.
        2006.10 KCI 등재 서비스 종료(열람 제한)
        The textile remains have been affected largely by environmental factors including microorganisms because they were composed of organic compounds to be easy to damage. So, we selected 8 strains of the 131 isolated strains from museum environments and textile remains by high protease activity, and identified them for measuring the antibacterial activity of Gingko biloba extracts. They were identified Genus Arthrobacter spp. 3 strains (Arthrobacter nicotiannae A12, Arthrobacter sp B12, Arthrobacter oxidans B13), Genus Bacillus spp. 2 strains (Bacillus licheniformis D9, Bacillus cereus D33), Genus Pseudomonas spp. 2 strains (Pseudomonas putida A24, Pseudomonas fluorescene C21) and a Genus Staphylococcus sp. 1 strain (Staphylococcus pasteuri D3) as closest strains through the blast search of NCBI. Though antibacterial activity of the extracts of Gingko biloba leaves as MIC was lower than that of other pharmaceutical antibiotics. However the extracts was crude extracts, the extracts might have good antibacterial against most of the isolates from museum. Especially, the antifungal activity of Gingko biloba is known previously, the extracts of Gingko biloba leaves has possibility of usage as a good natural material for conservation of remains.
        19.
        2002.03 KCI 등재 서비스 종료(열람 제한)
        A biosurfactant-producing microorganism was isolated from activated sludge by enrichment culture when grown on a minimal salt medium containing n-hexadecane as a sole carbon source. This microorganism was identified as Pseudomonas sp. and it was named Pseudomonas sp. EL-G527. It's optimal culture condition is 2% n-hexadecane, 0.2% NH4NO3, 0.3% KH2PO4, 0.3% K2HPO4, 0.02% MgSO4ㆍ7H2O, 0.0025% CaCl2ㆍ6H2O, 0.0015% FeSO4ㆍ7H2O in 1ℓ distilled water and initial pH 7.0. Cultivation was initiated with a 2% inoculum obtained from starter cultures grown in 30 ㎖ of the same medium in 250 ㎖ flask. They were cultivated at 30 ℃ in reciprocal shaking incubator and the highest biosurfactant production was observed after 4 days.
        20.
        2001.10 KCI 등재 서비스 종료(열람 제한)
        Pseudomonas sp. EL-04J was previously isolated from phenol-acclimated activated sludge. This bacterium was capable of degrading phenol and cometabolizing trichloroethylene (TCE). After precultivation in the mineral salts medium containing phenol as a sole carbon source, Pseudomonas EL-04J degraded 90% of TCE 25μM within 20 hours. Thus, phenol-induced Pseudomonas sp. EL-04J cells can degrade TCE. Following a transient lag period, Pseudomonas sp. EL-04J cells degraded TCE at concentrations of at least 250μM with no apparent retardation in rate, but the transformation capacity of such cells was limited and depended on the cell concentration. The degradation rate of TCE followed the Michaelis-Menten kinetic model. The maximum degradation rate (Vmax) and saturation constant (Km) were 7nmo ℓ/min·㎎ cell protein and 11μM, respectively. Cometabolism of TCE by phenol fed experiment was evaluated in 50·mℓ serum, vial that contained 10 ㎖ of meneral sals medium supplemented with 10μM TCE. TCE degradation was inhibited in the initial period of 1 mM phenol addition, but after that time Pseudomonas sp. EL-04J cells degraded TCE and showed cell growth.
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