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할로아세틸시코닌 유도체의 합성 및 항암성 평가 : Synthesis and Evaluation of Antitumor Activity
鄭相國,金光洙,송규용,조훈,안병준 충남대학교 약학대학 의약품개발연구소 1998 藥學論文集 Vol.14 No.-
The secondary hydroxy group at side chain of shikonin structure was selectively acylated with various haloacetic acids in presence of dicyclohexylcarbodiimide and 4-dimethylaminopyridine to produce haloacetylshikonin derivatives. The cytotoxicity of monohaloacetylshikonin derivatives against L1210 cells increased in the following order: monochloroacetylshikonin (ED_50, 0.142 ㎍/㎖) nonobromoacetylshikonin (ED_50, 0.158㎍/㎖)>monoiodoacetylshikonin (ED_50, 0.173 ㎍/㎖). Introduction of larger halogen atoms decreased the cytotoxic activity, presumably due to steric hinderance. The cytotoxicity of chloroacetylshikonin derivatives was dependent on the number of chlorine atom, thus increasing in the following order : trichloroacetylshikonin (0.032 ㎍/㎖)>dichloroacetylshikonin (0.059 ㎍/㎖)> monochloroacetylshikonin (ED_50, 0.142 ㎍/㎖). Thus, the electron-withdrawing effect seems to be important for the cytotoxicity of chloracetylshikonin derivatives. Consistent with the above, dichloracetylshikonin (T/C, 182%) and trifluoroacetylshikonin (195%) showed higher T/C values than monochloroacetyl-(T/C, 122%), monobromoacetyl-(T/C, 154%) and monoiodoacetylshikonin (T/C, 117%) derivatives. Haloacetylshikonin derivatives showing lower cytotoxic activities against L1210 cells exhibited lower T/C values. It seems that there is a relationship between the cytotoxicity of haloacetylshikonin and their antitumor activity.
Xiang, Jun-Yong,Lee, Sang-Ho,Kim, Jae-Kyeong 한국경영정보학회 2007 한국경영정보학회 학술대회논문집 Vol.2007 No.-
The importance of information technology (IT) has been emphasized in developing countries recently. Despite the importance of the topic area of the productivity of IT in developing countries, the literature to date is relatively sparse. The findings of almost all these studies are based on data collected in developed countries. Few studies have been conducted to validate these results and to see if they are still applicable in developing countries. This study tries to investigate the effects of IT investment on productivity in the electronics industry of China, which is a representative developing country, with production function model. The results show that there is a positive impact of IT investment on productivity in China similar to previous studies in developed countries.
Yong-Nan Xu,Sang-Jun Uhm,Bon-Chul Koo,Mo-Sun Kwon,Ji-Yeol Roh,Jung-Seok Yang,Hyun-Yong Choi,Young-Tae Heo,Xiang-Shun Cui,Joon-Ho Yoon,Dae-Hwan Ko,Teoan Kim,Nam-Hyung Kim 한국동물생명공학회(구 한국동물번식학회) 2013 Reproductive & Developmental Biology(Supplement) Vol.37 No.2s
The potential benefits of generating and using transgenic cattle range from im-provements in agriculture to the production of large quantities of pharmaceutically rele-vant proteins. Previous studies have attempted to produce transgenic cattle and other livestock by pronuclear injection and somatic cell nuclear transfer, but these approa-ches have been largely ineffective; however, a third approach, lentivirus-mediated trans-genesis, has successfully produced transgenic livestock. In this study, we generated transgenic (TG) Korean native cattle using perivitelline space injection of viral vectors, which expressed enhanced green fluorescent protein (EGFP) systemically. Two different types of lentiviral vectors derived from feline immunodeficiency virus (FIV) and human immunodeficiency virus (HIV) carrying EGFP were injected into the perivitelline space of MII oocytes. EGFP expression at 8-cell stage was significantly higher in the FIV group compared to the HIV group (47.5±2.2% vs. 22.9±2.9%). Eight- cell embryos that expressed EGFP were cultured into blastocysts and then transferred into 40 heifers. Ten heifers were successfully impregnated and delivered 10 healthy calves. All of these calves expressed EGFP as detected by in vivo imaging, PCR and Southern blotting. In addition, we established an EGFP-expressing cell line from TG calves, which was followed by nuclear transfer (NT). Recloned 8-cell embryos also expressed EGFP, and there were no differences in the rates of fusion, cleavage and development between cells derived from TG- and non-TG calves, which were subsequently used for NT. These results illustrate that FIV-based lentiviruses are useful for the production of TG cattle. Moreover, our established EGFP cell line can be used for additional studies that involve induced pluripotent stem cells.
Effects of combined BCG and DHEA treatment in preventing the development of asthma.
Cui, Yong,Choi, Inseon S,Koh, Young-Ah,Lin, Xiang-Hua,Cho, Yong-Bum,Won, Young-Ho Marcel Dekker 2008 Immunological investigations Vol.37 No.3
<P>Both BCG and dehydroepiandrosterone (DHEA) induce Th1 immune responses and suppress Th2 allergic reactions. To investigate whether the combination of BCG and DHEA has an additive effect on asthma prevention, BALB/c mice (n = 10 per group) were given an intraperitoneal injection of BCG at the beginning of sensitization, and fed mice chow containing DHEA throughout the study. In female mice, the combined administration of 2 x 10(4) CFUs BCG and 0.01% DHEA effectively suppressed the ovalbumin-induced increase in airway sensitivity to methacholine (56.5 vs. 8.2 mg/mL, p < 0.01), while BCG (13.9 mg/mL) or DHEA (17.9 mg/mL) alone did not. However, the addition of high dose (0.1%) DHEA decreased the efficacy of high dose (2 x 10(5) CFUs) BCG in suppressing the airway responsiveness and eosinophilia. In male mice, the treatments with BCG and/or DHEA were less effective, and the interferon-gamma/interleukin-4 ratio in the splenocyte supernatant was significantly higher and the ovalbumin-specific IgE concentration in the serum was significantly lower as compared to female mice. In conclusion, the combination of low doses of BCG and DHEA had an additive effect in suppressing the development of airway hypersensitivity. Androgens in males and DHEA overdose might reduce the efficacy of BCG.</P>