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        검색결과 162

        141.
        2009.03 KCI 등재 서비스 종료(열람 제한)
        스테로이드 함유 표시가 없는 화장품에서 항염증 효과가 있는 글루코코티코스테로이드인 베타메타손프로피오네이트 성분이 검출되었다. 이 화장품은 외용스프레이 및 샴푸로서 주성분으로 아연피리치온을 함유하는 것으로 표기되어 있었다. 화장품에서 스테로이드 구조와 활성을 갖는 물질의 존재를 확인하기 위하여 실리카겔 박층판을 이용한 박층크로마토그래프를 사용하였으며 이 성분을 분리하기 위해 high-performance liquid chromatography (HPLC)를 이용하여 확인 및 정량을 수행하였다. 분취용 HPLC를 이용하여 스테로이드를 함유한 것으로 판단되는 분획을 모은 다음 nuclear magnetic resonance (NMR) 및 mass spectrometry (MS)를 이용하여 스테로이드 성분을 확인하였다. 스테로이드 표준물질로 베타메타손 17-프로피오네이트 및 베타메타손 21-프로피오네이트를 합성하여 사용하였고 이 표준물질과 HPLC 크로마토그램을 비교하여 스테로이드 성분의 함량을 분석하였다. 이 방법으로 아연피리치온 제제와 같은 일부 시판 화장품에서 스테로이드 성분을 확인하였고 reversed-phase high-performance liquid chromatography (RP HPLC) 상의 유지시간 비교를 통하여 스테로이드 성분을 정량한 결과 시험한 총 8종의 화장품 시료 중 2개 제품에서 0.005 ∼ 0.02 %의 베타메타손프로피오네이트가 검출되었다.
        143.
        2008.10 KCI 등재 서비스 종료(열람 제한)
        The C3HC4 zinc RING finger proteins seem to be a family of protein-protein interactions. Little is information regarding the role of the C3HC4 zinc RING finger proteins in rice plant. We have attempted to assess their genome localization, phylogenetic relationship and expression patterns of members via in silico analysis as well as semi-quantitative RT-PCR. A total of 132 genes encoding C3HC4 zinc RING finger proteins appear to be distributed over 12 rice chromosomes, reflecting evolutionary dynamics of the rice genome, e.g. whole genome duplication and tandem duplications. A genome-wide dataset including 155 gene expression omnibus sample (GSM) plates evidenced a high degree of functional specialization of the rice C3HC4 zinc RING finger proteins, especially during developmental stages and against abiotic stresses. We have retrieved co-expression genes with each of the rice C3HC4 zinc RING finger proteins, probably providing some clues on specialized functions of individual genes. Expression patterns of 13 co-expression genes with one gene encoding C3HC4 zinc RING finger protein (Os04g51400) against salt and dehydration stresses were evaluated in crown tissues and leaf tissues, evidencing highly similar patterns among members. These findings might provide clues to shed further light on comprehensive functions of C3HC4 zinc RING finger proteins.
        144.
        2008.06 KCI 등재 서비스 종료(열람 제한)
        The germplasm of 246 rice cultivars was analysed  for iron and zinc contents using a Inductively Coupled Argon Plasma (ICP) at International Rice Research Institute (IRRI) Philippines. Iron contents ranged from 2.0 to 12.0, and zinc ranged from 10.0 to 33.0 (mg/kg), showing with the mean values of 4.3 and 22.8 (mg/kg), respectively. In genotypes tested, there was approximately a two-fold difference in iron and zinc concentrations, suggesting a genetic potential to increase these micronutrients in rice grain. A highly significant positive correlation (r2=0.503) was found between iron and zinc contents. Iron contents decreased drastically as polishing time increased, whereas zinc decreased only slightly. In the interaction between genotype and environment on iron contents, genotype (G), environment (E), and the G × E interactions accounted for 69%, 5% and 26% of the sums of squares, respectively. Indicating that genotype is would be the most significant factor for the to improve iron contents of rice in rice breeding, suggesting that therefore identifying genotypes with relatively stable performance across various environments is important as staple food crops.
        153.
        2006.12 KCI 등재 서비스 종료(열람 제한)
        The characteristics of photocatalytic degradation of tar colorants such as brilliant blue FCF(BBF) and tartrazine(TTZ) with zinc oxide suspension was studied in a batch reactor under irradiation of ultra-violet ray. Photocatalytic degradation of TTZ with ZnO was more higher than that of BBF, and was increased with dosage of ZnO below 5g, but was nearly affected with initial pH of two tar colorants aqueous solution. Ammonium persulfate was more effective oxidant than potassium bromate which slightly increased the degradation of BBF, but not increased the degradation of TTZ. The photocatalytic degradation rates of BBF and TTZ were pseudo-first order with rate constants of 0.0066, 0.0092 and 0.015min-1 for BBF, 0.042, 0.077 and 0.110min-1 for TTZ at the dosage of 1, 2 and 5g ZnO, respectively.
        156.
        2000.04 KCI 등재 서비스 종료(열람 제한)
        For the purpose of development of a liquid membrane permeator which separates metal ions from aqueous solutions continuously and effectively, a continuous membrane permeator with the membrane solution trapped between extraction and stripping phases by two micro-porous hydrophilic films was manufactured. Experimental researches on the separation of zinc ion from aqueous solutions were performed in the liquid membrane permeator with 30 vol % D2EHPA solution in kerosine as liquid membrane. As results, the liquid membrane permeator separates zinc ion from aqueous solutions continuously and effectively in the wide range of operating conditions. A simple mass transfer rate model using equilibrium constant of the extraction reaction for the system used were proposed, and the model was compared with experimental results of separation of zinc ion in the permeator. And the effects of operating factors, such as space time, pH of extraction solution, extraction temperature, on the separation rate of zinc ion in the permeator were experimentally examined.
        157.
        1999.12 KCI 등재 서비스 종료(열람 제한)
        Effects of surface conditions (temperature and roughness) of test specimens, when measuring emissive power of far-infrared ray, have been investigated using FT-IR spectrometer. Element metal zinc (Zn) was selected in this study as representative specimen of materials consisting of simple element. The zinc specimens were heated to four temperatures, i.e., 333K, 353K, .373K, and also their surface was finished with SiC abrasive papers of 100, 220, 360, 400, 600, 800, and 1000 mesh in size. The results shows that the emissive power (W/㎡) of the far-infrared ray increases with temperature for a given roughness and its relationship may be expressed by the following equations: Yη=1.0=0.142.T-0.937 for η=1.0, and Yη=10=0.016.T-1.286 for η=10. The emissive power is also known to increase with surface roughness for a given temperature. Their relationship can be represented by the following equations: YT=313K=0.234.ln(η)+3.53, at 313K, YT=353K=0.234.ln(η)+4.02 at 353K and YT=393K=0.243.ln(η)+4.62 at 393K.
        158.
        1999.06 KCI 등재 서비스 종료(열람 제한)
        The study was conducted to find the critical concentrations of zinc toxicity and to determine the changes of the contents of free proline and organic acids with treatment of different zinc chloride concentrations during rice germination and seedlings grown for seven days. The concentration of zinc chloride, 140 ppm, inhibited root elongation as much as 46 times compared with the control, and the germination rate was also decreased in all treatments of zinc chloride, showing that the germination rate decreased more with increasing concentrations of zinc chloride. Its rate was only 13% with treatment of 140 ppm zinc chloride. The content of free proline with treatment of zinc chloride, 140 ppm, was highest about 4,873 ~mu M at 3 days compared with the control. Malic acid concentration with treatment of zinc chloride, 140 ppm, increased to approximately 4 times compared to the control. Citric and succinic acid content were also slightly increased in all treatments of zinc chloride
        159.
        1998.06 KCI 등재 서비스 종료(열람 제한)
        An experimental research was preformed for the development of an effective process for zinc oxide waste(zinc ash) reuse. Zinc was selectively leached from zinc ash by 30 vol.% D_2EHPA in kerosine solution, and the leaching velocity was quite fast. Zinc leached was stripped by sulfuric acid solutions, and the amount of zinc stripped was linearly increased with the amount of sulfuric acid used. Zinc oxide fine particles were obtained by dropwise adding of sodium hydroxide solution to the resultant aqueous zinc solution at 85℃.
        160.
        1996.06 KCI 등재 서비스 종료(열람 제한)
        This study was performed to develop the biological treatment technology of wastewater polluted with heavy metals. Zinc-tolerant microorganism, such as Pseudomonas chlororaphis which possessed the ability to accumulate zinc, was isolated from industrial wastewaters polluted with various heavy metals. The characteristics of zinc accumulation in the cells, recovery of the zinc from the cells accumulating zinc, were investigated. Removal rate of zinc from the solution containing 100 ㎎/ℓ of zinc by zinc-tolerant microorganism was more than 90% at 48 hours after inoculation of the microorganisms. A large number of the electron-dense granules were found mainly on the cell wall and membrane fractions, when determined by transmission electron microscope. Energy dispersive X-ray spectroscopy revealed that the electron-dense granules were zinc complex with the substances binding heavy metals. The zinc accumulated into cells was not desorbed by distilled water, but more than 80% of the zinc accumulated was desorbed by 0.1M-EDTA. The residues of the cells after combustion at 550℃ amounted to about 21% of the dry weight of the cells. EDS analysis showed that the residues were comparatively pure zinc compounds containing more than 79% of zinc.
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