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Purification and Characterization of an Extracellular Protease from Bacillus pumilus CN8
Jin, Yong-Guo,Li, Hao-Li,Mal, Mei-Hu,Wang, Jun,Kim, Ha-Na,Oh, Deog-Hwan The Korean Society of Food Hygiene and Safety 2011 한국식품위생안전성학회지 Vol.26 No.1
The protease produced by a Bacillus pumilus CN8 strain was purified by DEAE-Cellulose-52 ion exchange. It has a molecular weight of approximately 96,920 Dalton. In the present study, this protease showed strong activity over a broad range of pH (6.5-9.5) and temperature from $40^{\circ}C$ to $60^{\circ}C$, and the protease performed the maximal activity at pH 7.3 at $42^{\circ}C$. The effect of metal ions on protease activity showed that $K^+$ could slightly increase the protease activity, and other ions such as $Zn^{2+}$, $Fe^{2+}$, $Na^+$, $Ca^{2+}$, $Mg^{2+}$ had no significant activation or inhibition to the protease (P> 0.05), and the more important is that $Cu^{2+}$, $Mn^{2+}$, $Sn^{2+}$, $Cd^{2+}$ had a strong inhibitory effect on the protease activity.
Wu, Yong,Jin, Lu,Xue, Ying,Xie, Dai Qian,Kim, Chan Kyung,Guo, Yong,Yan, Guo Sen Wiley Subscription Services, Inc., A Wiley Company 2008 Journal of computational chemistry Vol.29 No.8
<P>The hydrolysis reaction of N,N-dimethyl-N′-(2-oxo-1, 2-dihydro-pyrimidinyl)formamidine (DMPFA), a model compound of the antivirus drug amidine-3TC (3TC = 2′, 3′-dideoxy-3′-thiacytidine), is investigated by the hybrid density functional theory B3LYP/6-31+G (d,p) method. The hydrolysis reaction of the title compound is predicted to undergo via two pathways, each of which is a stepwise process. Path A is the addition of H<SUB>2</SUB>O to the C&n.dbond;N double bond in the amidine group to form a tetrahedral structure in its first step, and then the transfer of the H atom of hydroxyl leads to the corresponding products via four possible channels. Path B simultaneously involves the nucleophilic attack of H<SUB>2</SUB>O to the C atom of the C&n.dbond;N bond and the proton transfer to the N atom of amino group leading to the cleavage of the C&n.bond;N single bond in the amidine group. The results indicate that path A is more favorable than path B in the gas phase. Moreover, to simulate the title reaction in aqueous solution, water-assisted mechanism and the cluster-continuum model, based on the SCRF/CPCM model, are taken into account in our work. The results indicate that it is rational for two water molecules served as a bridge to assist in the first step of path A and that cytosine rather than the cytosine-substituted formamide should be released from the tetrahedral intermediate via s six-membered cycle transition state (channel 2). Our calculations exhibit that the process toward the tetrahedral intermediate is the rate-determining step both in the gas phase and in aqueous solution. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2008</P> <B>Graphic Abstract</B> <P> <img src='wiley_img/01928651-2008-29-8-JCC20883-gra001.gif' alt='wiley_img/01928651-2008-29-8-JCC20883-gra001'> </P>
Guo-jin Tan,Yong-chun Cheng,Han-bing Liu,Long-lin Wang 국제구조공학회 2011 Structural Engineering and Mechanics, An Int'l Jou Vol.38 No.3
Input excitation and output response of structure are needed in conventional modal analysis methods. However, input excitation is often difficult to be obtained in the dynamic load test of bridge structures. Therefore, what attracts engineers’ attention is how to get dynamic parameters from the output response. In this paper, a structural experimental modal analysis method is introduced, which can be used to conveniently obtain dynamic parameters of the structure from the free decay response. With known damping coefficients, this analysis method can be used to identify the natural frequencies and the mode shapes of MDOF structures. Based on the modal analysis theory, the mathematical relationship of damping ratio and frequency is obtained. By using this mathematical relationship to improve the previous method, an improved experimental modal analysis method is proposed in this paper. This improved method can overcome the deficiencies of the previous method, which can not identify damping ratios and requires damping coefficients in advance. Additionally, this improved method can also identify the natural frequencies, mode shapes and damping ratios of the bridge only from the free decay response, and ensure the stability of identification process by using modern mathematical means. Finally, the feasibility and effectiveness of this method are demonstrated by a numerical example of a simply supported reinforced concrete beam.
Synthesis and Evaluation of Antitumor Activity
Jin, Guang-Zhu,Song, Gyu-Yong,Zheng, Xiang-Guo,Kim, Yong,Sok, Dai-Eun,Ahn, Byung-Zun The Pharmaceutical Society of Korea 1998 Archives of Pharmacal Research Vol.21 No.2
Fourty eight derivatives of 2-(1-oxyalkyl)-1,4-dioxy-9,10-anthraquinone were synthesized, and their antitumor activity was evaluated. On the whole, 2-(1-hydroxyalkyl)-1,4-dihydroxy-9,10-anthraquinones (DHAQ=1,4-dihydroxy-9,10-anthraquinone) showed stronger cytotoxic activity against L1210 cells than 2-(l-hydroxyalkyl)-1,4-dimethoxy-9,10-anthraquinones(DMAQ =1,4-dimethoxy-9,10-anthraquinone), implying that free hydroxy groups at C-1 and C-4 of the anthraquinone structure are necessary for the cytotoxic activity. The bioactivity of 2-(lhydroxyalkyl)-DHAQ derivatives differed according to the size of alkyl group at C-1;while the elongation of alkyl group over 7 carbon atoms failed to enhance the bioactivity, the derivatives possessing alkyl moiety of 1-6 carbon atoms showed an increase in the cytotoxicity and the antitumor activity in Sarcoma-180; 2-hydroxymethyl-DHAQ ($ED_{50}$, $15\mu\textrm{g}$/ml; T/C, 125%), 2-(1 -hydroxyethyl)-DHAQ($1.9{\mu}g/ml;139.2%)$;, 2-(1-hydroxypropyl)-DHAQ ($7.2{\mu}g$/ml; 135.1%), 2-(1-hydroxybutyl)-DHAQ ($10.2{\mu}g/ml; 125.3%)$, 2-(1-hydroxypentyl)-DHAQ ($23.7{\mu}g/ml; 110.1%$). and 2-(1-hydroxyhexyl)-DHAQ ($58{\mu}g/ml;108%$). Next, 2-(1-Hydroxyalkyl)-DHAQ derivatives were acetylated to produce 2-(1-acetoxyalkyl)-DHAQ analogues. Although the acetylation somewhat enhanced the cytotoxicity, but not the antitumor action. In addition, the presence of phenyl group at $C-1^{l}$ enhanced the cytotoxicity and the T/C value, compared to alkyl groups of same size; 2-(1-hydroxy-1-phenyl)-DHAQ ($ED_{50}$, $5.6{\mu}g$, T/C, 137%).
Radiation Hybrid Mapping and mRNA Expression of Chicken N- myc downregulated gene 4
Yong Tian,Li Zhi Lu,Yan Fu,Ai Ping Yuan,Guo Qin Li,Qing Yan Yuan,Zheng Rong Tao,Jin Zhao 한국유전학회 2007 Genes & Genomics Vol.29 No.4
N-myc downregulated gene 4 (NDRG4) is a member of the N-myc downregulated gene family which belongs to the alpha/beta hydrolase superfamily. The protein encoded by this gene is a cytoplasmic protein that may be involved in the regulation of mitogenic signalling in vascular smooth muscle cells. To map NDRG4 gene in chicken chromosome, a 6,000 rads chicken- hamster radiation hybrid panel was used. Primers were designed according to the published human sequence for amplification of chicken NDRG4. We compared the corresponding human mRNA sequence with the predicted coding sequence of chicken NDRG4, and found that the assembled contig shared a high percentage of similarity with that of human gene. PCR of samples from ChickRH6 revealed the locations of NDRG4 to be linked to the maker PARD6G (5 cR away) with a LOD score 20.46. In addition, we detected the mRNA expression and distribution of chicken NDRG4 in various tissues by RT-PCR, and found that NDRG4 was highly expressed in chicken brain and heart, whereas lowly but detectable in thymus. The mRNA expression of this gene in chicken liver, spleen, lung and muscle was rarely detectable under present experimental conditions.
林蛙(Rana temporaria chinesis David) 皮膚 色素細胞의 徵細構造
金龍勳,文仁祜,嚴昌國,盧鏞泰,朴仁峰 建國大學校基礎科學硏究所 1992 理學論集 Vol.17 No.-
林蛙의 皮膚色素胞인 멜라닌色素胞,黃色素胞 및 紅色素胞를 電子顯微鏡으로 觀察하여 다음과 같은 結果를 얻었다. 멜라닌色素胞 : 멜라닌色素胞의 全 細胞質에는 電子密度가 같은 멜라닌 色素顆粒으로 충만되어 있으며, 核은 細胞質 한쪽으로 치우쳤고 楕圓形이거나 不定形이다. 대부분의 멜라닌色素胞는 細胞質突起를 가지며 黃色素胞와 紅色素胞 사이에 나타나는 경우가 많았다. 黃色素胞 : 黃色素胞는 다수의 pterinosome과 소수의 carotenoid vesicle의 色素小器官으로 構成되었다. 그중 pterinosomem 은 小囊 속의 內容物質에 따라, 內容物質이 없는 것을 第1型 pterinosome, 小囊 속에 纖維質이 散在한 것을 第 2 型 pterinosome. 小囊 속에 소수의 lamel-lae層을 形成한 것을 第 3 型 pterinosome,그리고 小囊 속에 다수의 lamellae를 形成한 것을 第 4 型 pterinosome으로 區別.觀察하였다. 紅色素胞 : 紅色素胞는 長方形 等 不定形의 反射小板으로 채워져 있다. 黃色素胞와 멜라닌色素胞,멜라닌色素胞와 멜라닌色素胞 사이 等에 連接하였다. The ultrastructures of the pigment cells in the Rana temporaria chinensis dorsal skin were observed with electron microscope. The results of the fine structure in the melanophores,xanthophores and iridophores were as follow: Melanophores:Epidermal melanophores were filled with melanin granules which ap-peared as the same electron density. A few melanin granules were observed in a cornified cell. Dermal melanophores contained numerous melanin granules extended up the lateral sides of the xanthophores and iridophores. Xanthophores:Xanthophores were filled with pterinosomes and carotenoid vesicles. Type I pterinosomes had a clear limiting membrane. Type Ⅱ pterinosomes had the inner fibrous structure. Type Ⅲ pterinosomes were charavterized by a few superficial lamellae and Type Ⅳ pterinosomes by multiple concentric lamellae. Iridophores:Iridophores were filled with reflective platelets,each of which is rectangle and shapelessness.
IN SITU UNZIPPING OF CARBON NANOTUBES TO FORM GRAPHENE NANORIBBONS
YONG-SHENG ZHOU,PAN JIN,TENG GUO,YING-CHUN ZHU,GAO-HUI DU,BING-SHE XU 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2014 NANO Vol.9 No.1
We report the one step facile synthesis of graphene nanoribbons (GNRs) by unzipping carbonnanotubes (CNTs) from glucose (C 6 H 12 O 6 ) precursor, using a simple chemical vapor depositionmethod. Some nanotubes are partially cut resulting in a GNR – CNT hybrid whereas others arefully cut to form GNRs. The average length of GNRs achieved by this method is typically in therange of 1 – 10 ? m. The formation of GNRs is ascribed to the in situ oxygen-driven unzipping ofCNTs. The process is free from aggressive oxidants and utilizes the in situ unzipping. Thismethod o®ers an alternative approach for making GNRs, compared to previously used techniquesto synthesize GNRs.