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951.
The design and synthesis of new fluoroquinolone antibacterial agents having substituted piperidine rings at the C-7 position are described. Most of the new compounds demonstrated high in vitro antibacterial activity. Several of them exhibited significant activities against gram-positive organisms, which were more potent than those of gemifloxacin, Linezolid, and vancomycin. 相似文献
952.
Renslo AR Atuegbu A Herradura P Jaishankar P Ji M Leach KL Huband MD Dermyer MR Wu L Vara Prasad JV Gordeev MF 《Bioorganic & medicinal chemistry letters》2007,17(18):5036-5040
Oxazolidinone analogs bearing substituted piperidine or azetidine C-rings are described. Analogs with a methyl group at the 3-position of the azetidine ring or the 4-position of the piperidine ring exhibited reduced mitochondrial protein synthesis inhibition while retaining good antibacterial potency. 相似文献
953.
Role of follicle stimulating hormone and epidermal growth factor in the development of porcine preantral follicle in vitro 总被引:2,自引:0,他引:2
The aim of the present study was to assess the role of follicle stimulating hormone (FSH), epidermal growth factor (EGF) or a combination of EGF and FSH on the in vitro growth of porcine preantral follicles, estradiol secretion, antrum formation, oocyte maturation and subsequent embryonic development. Porcine preantral follicles were cultured for 3 days in the absence or in the presence of FSH or EGF. Oocytes from these follicles were then matured, fertilized in vitro and embryos were cultured. Estradiol secretion and histological analysis of cultured follicles were also carried out. The results showed that when FSH, or a combination of EGF and FSH, was added to the culture medium, most of preantral follicles grew to antral follicles with high estradiol secretion and the oocytes from these antral follicles could mature, fertilize and develop to the blastocyst stage. Without FSH, or a combination of EGF and FSH, preantral follicles were unable to develop to the antral stage. Histology demonstrated that the resulting follicles were nonantral, estradiol production was reduced and none of their oocytes matured after in vitro maturation. The results indicate the essential role of FSH in promoting in vitro growth of porcine preantral follicle, estradiol secretion, antrum formation, oocyte maturation and subsequent embryonic development. EGF with FSH treatment of porcine preantral follicles improves the quality of oocytes, shown by a higher frequency of embryonic development. 相似文献
954.
Park CH Lee J Jung HY Kim MJ Lim SH Yeo HT Choi EC Yoon EJ Kim KW Cha JH Kim SH Chang DJ Kwon DY Li F Suh YG 《Bioorganic & medicinal chemistry》2007,15(20):6517-6526
The quinolone analog SQ-4004 has been identified as a potentially excellent anti-ischemic agent, which exhibited highly potent efficacy in reducing infarct volume size in vivo rat MCAO model (32.1% at 0.01mg/kg) and potent cardioprotective effect at myocardial infarction in vivo model (26.6% at 0.01mg/kg) while it exhibited highly reduced anti-bacterial activity. The mechanistic study revealed that the anti-ischemic activity might exert via an anti-apoptotic pathway, which implies its therapeutic uses against the ischemic cell injuries including ischemic stroke and ischemic heart disease. 相似文献
955.
A series of novel bis(L-amino acid) ester prodrugs of 9-[2-(phosphonomethoxy)ethyl] adenine (PMEA) was synthesized and their anti-HBV activity was evaluated in HepG 2 2.2.15 cells. Compounds 11, 12, 21, 22, 26, and 27 demonstrated more potent anti-HBV activity and higher selective index (SI) than adefovir dipivoxil, which was used as a positive control. Compound 11, which was found to be the most potent one, was five times more potent than adefovir dipivoxil with EC50 value of 0.095 microM and CC50 value of 6636 microM. The SI value (>69,000) of compound 11 was 60 times and 24 times higher than those of adefovir dipivoxil and lamivudine, respectively. In vitro stability studies showed that compound 11 was relatively more stable than adefovir dipivoxil with t1/2 of 270 min. These findings suggested that compound 11 could be considered as a promising candidate for further in vivo studies. 相似文献
956.
中国西北地区松科和柏科气孔器形态 总被引:2,自引:0,他引:2
现代针叶树气孔器的研究为鉴定化石气孔器奠定了基础,对第四纪植被变化和古气候的研究起着很重要的作用,是第四纪孢粉学的一个重要补充。本文运用常规的标准的孢粉分析方法,对中国西北地区常见的松科3属8种和柏科3属4种植物气孔器进行了观察分析。结果表明凭气孔器大小可以区分松科与柏科。利用气孔器大小、T型结构的形状?上部木质片与气孔器茎之间的夹角进行属的鉴别,再结合茎的长度、宽度、中间木质部的宽、T型外角度和上部木质片外缘形状等可以进行种的鉴别,并编制了一个初步的检索表。 相似文献
957.
Polymorphisms in the 5′ regulatory region of myostatin gene are associated with early growth traits in Yorkshire pigs
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Yu LingZhi Tang Hui Wang JiYing Wu Ying Zou LiLi Jiang YunLiang Wu ChangXin Li Ning 《中国科学C辑(英文版)》2007,50(5):642-647
Myostatin is a negative regulator of skeletal muscle mass. The present study cloned the 5′ regulatory region of porcine myostatin
gene, screened its polymorphisms and analyzed their associations with early growth traits in Yorkshire pigs. The results indicated
that a fragment length polymorphism and a polymorphism concerning two nucleotide changes exist in the 5′ regulatory region
of porcine myostatin gene. At sites 435 and 447, allele A and allele B have the haplotypes of A-G and G-A, respectively. The
allelic frequency of B is 0.475 in Yorkshire pigs. No homozygous BB genotype was detected in 9 Laiwu Black pigs. Allele B
was found to have positive effect on body weight on day 21 (BW21) (P<0.01), body weight on day 28 (BW28) (P<0.05), body weight on day 70 (BW70) (P<0.05), average daily gain from birth to 21 d (ADG1) (P<0.01), average daily gain from birth to 28 d (ADG2) (P<0.05) and average daily gain from 21 d to 70 d (ADG3) (P<0.01), respectively. The additive effect of allele B on BW21, BW28, BW70, ADG1, ADG2 and ADG3 was 0.596±0.205 kg (P=0.0041), 0.498±0.200 kg (P=0.0136), 1.409±0.551 kg (P=0.0112), 28.39±9.74 g P=0.0041), 17.78±7.15 g (P=0.0136) and 37.00±16.92 g (P=0.0304), respectively, whereas its effect on average daily gain from 28 d to 70 d (ADG4) was not significant (P>0.1), although BB individuals are superior in average daily gain to AA and AB. 相似文献
958.
Ji Young Hyun Kodiveri Muthukalianan Gothandam Nam Kwon Baek Gongwei Wang Yong-Yoon Chung 《Journal of Plant Biology》2007,50(2):161-166
InBrassica, self-incompatibility (SI) can be overcome by CO2 application, an effective method for obtaining numerous inbred lines for F, commercial seed. We previously reported two different
S-alleles ofBrassica campestris, S733 and S734, with extremely different degrees of susceptibility to this gas. In the current study, we raised a cross-population between
those two genetic lines, and analyzed their reaction level of self-incompatibility to CO2 (RLSICO2). Here, all 40 of our progeny from the F1 cross-population were susceptible, maintaining high values of RLSICO2. This suggests that the susceptible line, S734, is dominant to the insusceptible line, S733. We also generated an F2 selfing-population of each crossed progeny, S733♀ S734♂ and S733♂ S734♀, to assess the RLSICO2 of each individual. PCR-RFLP analysis was performed to determine the S-genotype of the F2 population. The S734 allele segregated in a theoretical ratio of the dominant trait, and the RLSICO2 was consistent with the dominance relationship. Therefore, we have now demonstrated that high RLSICO2 in β.campestris is controlled by a dominant gene.
Both authors contributed equally to this work 相似文献
959.
960.