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981.
细菌(Pseudomonas moltophilia)与hCG及LH有特异的亲和力,实验发现,细菌之生长曲线与hCG结合活性成平行关系,96小时达高峰,细菌之培养液中含有可溶性结合蛋白,该蛋白经硫酸铵沉淀(80%饱和度)、Sephadex G-100柱层析、DEAE-纤维素柱0.5mol/L NaCl梯度洗脱,再过Sepharose CL-AB柱,收集之活性部分经SDS电泳测得其分子量为70,000,凝胶层析测Stokes radius为41A,Schiff氏染色未见着色带。 相似文献
982.
阿维链霉菌中aveD基因缺失对阿维菌素合成的影响 总被引:11,自引:0,他引:11
利用aveD基因的缺失载体pCZ8(pKC1139∷△aveD)对阿维菌素(Avermectin)产生菌阿维链霉菌(Streptomyces avermitilis)76\|9的aveD基因进行缺失获得aveD缺失突变株。经摇瓶发酵和HPLC检测,发现该突变株只产生阿维菌素B组分。说明将阿维链霉菌的aveD基因缺失,并不影响下游aveF的表达。缺失突变株的阿维菌素的总产量与出发菌株的总产量基本相同,突变株中B1的产量略有提高,阿维菌素B2的含量显著提高。 相似文献
983.
984.
Mayank Singh Clayton R. Hunt Raj K. Pandita Rakesh Kumar Chin-Rang Yang Nobuo Horikoshi Robert Bachoo Sara Serag Michael D. Story Jerry W. Shay Simon N. Powell Arun Gupta Jessie Jeffery Shruti Pandita Benjamin P. C. Chen Dorothee Deckbar Markus L?brich Qin Yang Kum Kum Khanna Howard J. Worman Tej K. Pandita 《Molecular and cellular biology》2013,33(16):3390
985.
Li-Gang Yang Joseph D. Tucker Feng-Ying Liu Xu-Qi Ren Xuan Hong Cheng Wang Megan M. McLaughlin Cedric H. Bien Xiang-Sheng Chen Bin Yang 《PloS one》2013,8(8)
Objectives
To determine the prevalence and correlates of syphilis among pregnant women in rural areas of South China.Methods
Point-of-care syphilis testing was provided at 71 health facilities in less developed, rural areas of Guangdong Province. Positive samples were confirmed at a local referral center by toluidine red unheated serum tests (TRUST) and Treponema pallidum particle agglutination (TPPA) tests.Results
Altogether 27,150 pregnant women in rural Guangdong were screened for syphilis. 106 (0.39%) syphilis cases were diagnosed, of which 78 (73.6%) received treatment for syphilis. Multivariate analysis revealed that older pregnant women (31–35 years old, aOR 2.7, 95% CI 0.99–7.32; older than 35 years old, aOR 5.9, 95% CI 2.13–16.34) and those with a history of adverse pregnant outcomes (aOR 3.64, 95% CI 2.30–5.76) were more likely to be infected with syphilis.Conclusions
A high prevalence of syphilis exists among pregnant women living in rural areas of South China. Enhanced integration of syphilis screening with other routine women''s health services (OB GYN, family planning) may be useful for controlling China''s syphilis epidemic. 相似文献986.
Zhigang Ren Guangying Cui Haifeng Lu Xinhua Chen Jianwen Jiang Hui Liu Yong He Songming Ding Zhenhua Hu Weilin Wang Shusen Zheng 《PloS one》2013,8(10)
Background
Ischemia-reperfusion (I/R) injury is associated with intestinal microbial dysbiosis. The “gut-liver axis” closely links gut function and liver function in health and disease. Ischemic preconditioning (IPC) has been proven to reduce I/R injury in the surgery. This study aims to explore the effect of IPC on intestinal microbiota and to analyze characteristics of microbial structure shift following liver transplantation (LT).Methods
The LT animal models of liver and gut IPC were established. Hepatic graft function was assessed by histology and serum ALT/AST. Intestinal barrier function was evaluated by mucosal ultrastructure, serum endotoxin, bacterial translocation, fecal sIgA content and serum TNF-α. Intestinal bacterial populations were determined by quantitative PCR. Microbial composition was characterized by DGGE and specific bacterial species were determined by sequence analysis.Principal Findings
Liver IPC improved hepatic graft function expressed as ameliorated graft structure and reduced ALT/AST levels. After administration of liver IPC, intestinal mucosal ultrastructure improved, serum endotoxin and bacterial translocation mildly decreased, fecal sIgA content increased, and serum TNF-α decreased. Moreover, liver IPC promoted microbial restorations mainly through restoring Bifidobacterium spp., Clostridium clusters XI and Clostridium cluster XIVab on bacterial genus level. DGGE profiles indicated that liver IPC increased microbial diversity and species richness, and cluster analysis demonstrated that microbial structures were similar and clustered together between the NC group and Liver-IPC group. Furthermore, the phylogenetic tree of band sequences showed key bacteria corresponding to 10 key band classes of microbial structure shift induced by liver IPC, most of which were assigned to Bacteroidetes phylum.Conclusion
Liver IPC cannot only improve hepatic graft function and intestinal barrier function, but also promote restorations of intestinal microbiota following LT, which may further benefit hepatic graft by positive feedback of the “gut-liver axis”. 相似文献987.
Shengjun Wu Zhengyu Jin Jin Moon Kim Qunyi Tong Hanqing Chen 《Carbohydrate polymers》2009,77(4):750-753
pullulan, a water soluble extracellular polysaccharide, was produced by downstream fermentation employing the strain Aureobasidium pullulans. To obtain pure biopolymer from the fermentation broth, it is necessary to harvest cells, heat the broth, remove the melanin pigments co-produced during fermentation, concentration, precipitate and dry. Centrifugation of the fermentation broth at 10,000 rpm for 15 min gave cell pellets that were discarded and a green–black supernatant containing melanin pigment was subjected to the heat treatment at 80 °C for 20 min in order to remove the protein in the fermentation broth. The supernatant was demelanized by oxidation with hydrogen peroxide, concentrated under vacuum, precipitated with ethanol and dried at 60 °C for 30 min. This procedure produced high purity pullulan that was comparable in color and texture to the commercial samples. 相似文献
988.
The emerging view of smooth/nonmuscle myosin regulation suggests that the attainment of the completely inhibited state requires numerous weak interactions between components of the two heads and the myosin rod. To further examine the nature of the structural requirements for regulation, we engineered smooth muscle heavy meromyosin molecules that contained one complete head and truncations of the second head. These truncations eliminated the motor domain but retained two, one, or no light chains. All constructs contained 37 heptads of rod sequence. None of the truncated constructs displayed complete regulation of both ATPase and motility, reinforcing the idea that interactions between motor domains are necessary for complete regulation. Surprisingly, the rate of ADP release was slowed by regulatory light chain dephosphorylation of the truncated construct that contained all four light chains and one motor domain. These data suggest that there is a second step (ADP release) in the smooth muscle myosin-actin-activated ATPase cycle that is modulated by regulatory light chain phosphorylation. This may be part of the mechanism underlying "latch" in smooth muscle. 相似文献
989.
棉铃虫为马尾松毛虫多角体病毒 (DPCPV)理想的替代寄主。试验结果表明 ,不同接毒方法、接种浓度、接种温度及接种虫龄对棉铃虫增殖病毒有影响 ,以病毒涂在人工饲料表面的接毒方法、2 0~ 2 3℃温度及 3龄虫为最佳组合条件。由于利用棉铃虫生产出的病毒 (Ha DPCPV)容易诱发棉铃虫本身的多角体病毒 (NPV) ,尤其对那些带有NPV源的虫种 ,Ha DPCPV不宜作毒种 ,因此为慎重起见 ,最好用马尾松毛虫复制出的病毒作为生产毒种。 相似文献
990.
The fluorescence and the base pairing properties of 8-aza-7-deaza-2'-deoxyisoinosine (1) are described and compared with those of 2'-deoxyisoinosine (2). The corresponding phosphoramidites (11, 12) are synthesized using the diphenylcarbamoyl (DPC) residue for the 2-oxo group protection. The nucleosides 1 and 2 base pair with 2'-deoxy-5-methylisocytidine in DNA duplexes with antiparallel chain orientation and with 2'-deoxycytidine in a parallel DNA. These base pairs are less stable than the canonical dA-dT pair and that of 2'-deoxyinosine (4) with 2'-deoxycytidine. The fluorescence of the nucleosides 1 and 2 is quenched (approximately 95%) in duplex DNA. The residual fluorescence is used to determine the Tm-values, which are found to be the same as determined UV-spectrophotometrically. 相似文献