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排序方式: 共有1357条查询结果,搜索用时 15 毫秒
91.
A bacterium designated strain B113, able to degrade benzene, toluene, and ethylbenzene compounds (BTE), was isolated from gasoline-contaminated sediment at a gas station in Geoje, Korea. Phylogenetic analysis based on 16S rRNA gene sequences showed that the isolate belonged to the genus Acinetobacter. The biodegradation rates of benzene, toluene, and ethylbenzene were relatively low in MSB broth, but the addition of yeast extract had a substantial impact on the biodegradation of BTE compounds, which suggested that yeast extract might provide a factor that was necessary for its growth or BTE biodegradation activity. However, interestingly, the biodegradation of BTE compounds occurred very quickly in slurry systems amended with sterile soil. Moreover, if soil was combusted first to remove organic matters, the enhancement effect on BTE biodegradation was lost, indicating that some insoluble organic compounds were probably beneficial for BTE degradation in contaminated sediment. This study suggests that strain B113 may play an important role for biodegradation of BTE in the contaminated site.  相似文献   
92.
目的:研究吗啡对胎动、心率、孵化率、孵化时间、雏鸡体重等的影响。方法:以气室给药的方式给鸡胚注射吗啡,记录胎动、心率、孵化率、孵化时间、雏鸡体重。结果:吗啡可以缩短雏鸡的孵化时间,降低雏鸡的孵化率,并导致雏鸡出现运动障碍;20mg/kg吗啡剂量和12—16胚龄的给药时间,鸡胚孵化率最高,残疾率最低;吗啡导致胚胎心率加快,胎动减少(P〈0.05)。结论:吗啡对胚胎发育有损伤作用,损伤程度与吗啡剂量和给药时间有关。  相似文献   
93.
94.
The cholesterol side chain cleavage enzyme (CYP11A1) gene plays an important part in the synthesis of sex hormones and has been reported to be involved in the pathogenesis of polycystic ovary syndrome. A case-control study including 314 PCOS patients and 314 controls was conducted to assess the association of the SNPs rs4077582 and rs11632698 in CYP11A1 with PCOS using the polymerase chain reaction-restriction fragment length polymorphism method. Thereafter, 100 DNA samples were re-genotyped by direct sequencing for confirmation. The genotypic distribution of rs4077582 in women with PCOS differed from that in controls (P = 0.002). No such distributional difference was found in rs11632698 (P = 0.912). Data from our previous study of these two SNPs in another population including 290 PCOS patients and 344 controls was combined with the current data. Combined analysis (a total of 1262 participants, including 604 PCOS patients and 658 control women) showed a much more significant difference in the genotypic distribution of rs4077582 between PCOS and controls (P < 0.001). The T allele was more prevalent in PCOS patients (Odds ratio = 1.314; 95 % CI 1.122-1.540). The testosterone levels among the three genotypes for rs4077582 were different in the control group, as were the LH levels and the LH/FSH ratio. Therefore, SNP rs4077582 in CYP11A1 is strongly associated with susceptibility to PCOS and may alter the testosterone levels by the regulation of LH in different genotypes. No association was observed in rs11632698.  相似文献   
95.
The gene cluster composed of varicella-zoster virus (VZV) open reading frame 9 (ORF9) to ORF12 encodes four putative tegument proteins and is highly conserved in most alphaherpesviruses. In these experiments, the genes within this cluster were deleted from the VZV parent Oka (POKA) individually or in combination, and the consequences for VZV replication were evaluated with cultured cells in vitro and with human skin xenografts in SCID mice in vivo. As has been reported for ORF10, ORF11 and ORF12 were dispensable for VZV replication in melanoma and human embryonic fibroblast cells. In contrast, deletion of ORF9 was incompatible with the recovery of infectious virus. ORF9 localized to the virion tegument and formed complexes with glycoprotein E, which is an essential protein, in VZV-infected cells. Recombinants lacking ORF10 and ORF11 (POKADelta10/11), ORF11 and ORF12 (POKADelta11/12), or ORF10, ORF11 and ORF12 (POKADelta10/11/12) were viable in cultured cells. Their growth kinetics did not differ from those of POKA, and nucleocapsid formation and virion assembly were not disrupted. In addition, these deletion mutants showed no differences compared to POKA in infectivity levels for primary human tonsil T cells. Deletion of ORF12 had no effect on skin infection, whereas replication of POKADelta11, POKADelta10/11, and POKADelta11/12 was severely reduced, and no virus was recovered from skin xenografts inoculated with POKADelta10/11/12. These results indicate that with the exception of ORF9, the individual genes within the ORF9-to-ORF12 gene cluster are dispensable and can be deleted simultaneously without any apparent effect on VZV replication in vitro but that the ORF10-to-ORF12 cluster is essential for VZV virulence in skin in vivo.  相似文献   
96.
R Feng  X Zhou  PM Or  JY Ma  XS Tan  J Fu  C Ma  JG Shi  CT Che  Y Wang  JH Yeung 《Phytomedicine》2012,19(12):1125-1133
Halenia elliptica D. Don is a Tibetan herb and medicinal preparations containing Halenia elliptica have been commonly used for the treatment of hepatitis B virus infection in China. The metabolism of 1-hydroxy-2,3,5-trimethoxy-xanthone (HM-1) to its metabolites is mediated through cytochrome P450 enzymes. This study aimed to investigate the herb-drug interaction potential of HM-1 by studying its effects on the metabolism of model probe substrates of five major CYP450 isoforms in human liver microsomes. HM-1 showed moderate inhibitory effects on CYP1A2 (IC(50)=1.06μM) and CYP2C9 (IC(50)=3.89μM), minimal inhibition on CYP3A4 (IC(20)=11.94μM), but no inhibition on model CYP2D6 (dextromethorphan) and CYP2E1 (chlorzoxazone) probe substrates. Inhibition kinetic studies showed that the K(i) values of HM-1 on CYP1A2, CYP2C9 and CYP3A4 were 5.12μM, 2.00μM and 95.03μM, respectively. HM-1 competitively inhibited testosterone 6β-hydroxylation (CYP3A4) but displayed mixed type inhibitions for phenacetin O-deethylation (CYP1A2) and tolbutamide 4-hydroxylation (CYP2C9). Molecular docking study confirmed the inhibition modes of HM-1 on these human CYP isoforms.  相似文献   
97.
为解决柴胡及其体细胞杂种愈伤组织中次生代谢物多,同工酶粗提液粘稠、杂质多且呈混浊态,同工酶电泳谱带不清晰及易拖尾的问题,通过增加离心次数、调整酶粗提液上样体积等方法,得到了理想的酯酶同工酶电泳谱带。该法广泛适用于其它植物的同工酶聚丙烯酰胺凝胶电泳分析。  相似文献   
98.
聚羟基脂肪酸酯(Polyhydroxyalkanoates,简称PHA)是由微生物合成的天然高分子基材料,作为微生物碳源和能源的储备物质。目前,PHA的单体种类有150多种,致使PHA的品种繁多、材料学性质各不相同。PHA具有材料多变性、非线性光学性能、压电性能、气体阻隔性能、热塑性、生物可降解性、良好的生物相容性等特点,使其在塑料包装、化工、医药、农业、生物能源等诸多领域的具有很大的应用前景。文中系统介绍了目前PHA的应用和未来的发展。  相似文献   
99.
100.
A standard technique for static optical rotatory dispersion (ORD) measurements is adapted to the measurement of ORD changes on a nanosecond (ns) time scale, giving approximately a million-fold improvement in time-resolution over conventional instrumentation. The technique described here is similar in principle to a technique recently developed for ns time-resolved circular dichroism (TRCD) spectroscopy, although the time-resolved optical rotatory dispersion (TRORD) technique requires fewer optical components. As with static ORD, TRORD measurements may be interpreted by empirical comparisons or may be transformed, via the Kramers-Kronig relations, to more easily interpreted TRCD spectra. TRORD can offer experimental advantages over TRCD in studying kinetic processes effecting changes in the chiral structures of biological molecules. In particular, the wider dispersion of ORD bands compared with the corresponding CD bands means that ORD information may often be obtained outside of absorption bands, a signal-to-noise advantage for multichannel measurements. Demonstration of the technique by its application to ns TRORD and the transform-calculated TRCD of carboxy-hemoglobin (Hb-CO) after laser photolysis is presented.  相似文献   
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