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51.
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为分析夏尔巴人的体质特征,2016年在西藏测量了182例(男性98例,女性84例)夏尔巴人成人的头面部及体部指标。运用Excel 2010和SPSS 21.0对数据进行统计分析。夏尔巴人的分析结果显示,根据头面部指标均数,夏尔巴人男性和女性属于圆头型、高头型、阔头型、中鼻型。根据体部指标均数,夏尔巴人男性和女性属于中躯干型、中肩型、窄骨盆型和亚中等身高,男性为亚长腿型,女性为中腿型。与其他族群对比发现,夏尔巴人体质特征与门巴族最接近,其次是珞巴族,属于藏彝走廊类型。国内目前尚无夏尔巴人的体质特征报道,本研究丰富了民族体质数据资料库,为研究夏尔巴人的族源提供了一定的数据支持。 相似文献
53.
Regulation of tissue-type plasminogen activator and plasminogen activator inhibitor type-1 in cultured rat Sertoli and Leydig cells 总被引:3,自引:0,他引:3
New data are provided to show that (i) rat Sertoli cells produce two types of plasminogen activators, tissue type (tPA) and urokinase type (uPA), and a plasminogen activator inhibitor type-1 (PAI-1); (ii) both tPA (but not uPA) and PAI-1 secretion in the culture are modified by FSH, forskolin, dbcAMP, GnRH, PMA and growth factors (EGF and FGF), but not by hCG and androstenedione (△4); (iii) in vitro secretion of tPA and PA-PAI-1 complexes of Sertoli cells are greatly enhanced by presence of Leydig cells which produce negligible tPA but measurable PAI-1 activity;(iv) combination culture of Sertoli and Leydig cells remarkably increases FSH-induced PAI-1 activity and decreases hCG- and forskolin-induced inhibitor activity as compared with that of two cell types cultured alone. These data suggest that rat Sertoli cells, similar to ovarian granulosa cells, are capable of secreting both tPA and uPA, as well as PAI-1. The interaction of Sertoli cells and Leydig cells is essential for the cells to response to 相似文献
54.
Herpes simplex virus-1 US11 is a RNA-binding protein with a novel RNA-binding domain. US11 has been reported to exhibit sequence- and conformation-specific RNA-binding, but the sequences and conformations important for binding are not known. US11 has also been described as a double-stranded RNA (dsRNA)-binding protein. To investigate the US11–RNA interaction, we performed in vitro selection of RNA aptamers that bind US11 from a RNA library consisting of >1014 80 base sequences which differ in a 30 base randomized region. US11 bound specifically to selected aptamers with an affinity of 70 nM. Analysis of 23 selected sequences revealed a strong consensus sequence. The US11 RNA-binding domain and ≤46 bases of selected RNA containing the consensus sequence were each sufficient for binding. US11 binding protected the consensus motif from hydroxyl radical cleavage. RNase digestions of a selected aptamer revealed regions of both single-stranded RNA and dsRNA. We observed that US11 bound two different dsRNAs in a sequence non-specific manner, but with lower affinity than it bound selected aptamers. The results define a relatively short specific sequence that binds US11 with high affinity and indicate that dsRNA alone does not confer high-affinity binding. 相似文献
55.
Hongming Lou Meilu Lin Meijun Zeng Cheng Cai Yuxia Pang Dongjie Yang Xueqing Qiu 《Bioenergy Research》2018,11(2):456-465
Effect of hydrogen bond breaker (urea) addition on the enzymatic hydrolysis of Avicel and eucalyptus pretreated by dilute acid (Eu-DA) was investigated. Urea enhanced the enzymatic hydrolysis of Eu-DA at 50 or 30 °C when the concentration of urea was below 60 g/L, while it inhibited the hydrolysis of Avicel. Low concentration urea (<?240 g/L) had little effect on the cellulase spatial structure and its activity. But it decreased cellulase binding to cellulose surface to inhibit the cellulose hydrolysis. Meanwhile, urea obviously prevented the adsorption of cellobiohydrolase I (CBHI) on the lignin in spite of little effect on the adsorption of β-glucosidase (BGL) and two endoglucanases (EGIII and EGV) on lignin. It was proposed that urea enhanced the enzymatic efficiency of Eu-DA by decreasing the cellulase adsorption on lignin surface. 相似文献
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Li Huixian Huang Yali Zhang Jiong Du Jikun Tan Hongming Lu Yongjun Zhou Shining 《World journal of microbiology & biotechnology》2011,27(11):2729-2736
World Journal of Microbiology and Biotechnology - A putative methionine γ-lyase (MGL) gene was identified from a deep-sea sediment metagenomic library. The gene (mgl_deepsea), consisting of... 相似文献
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Surface plasmon resonance imaging (SPRi) is an intriguing technique for immunoassay with the inherent advantages of being high throughput, real time, and label free, but its sensitivity needs essential improvement for practical applications. Here, we report a dual signal amplification strategy using functional gold nanoparticles (AuNPs) followed by on-chip atom transfer radical polymerization (ATRP) for sensitive SPRi immunoassay of tumor biomarker in human serum. The AuNPs are grafted with an initiator of ATRP as well as a recognition antibody, where the antibody directs the specific binding of functional AuNPs onto the SPRi sensing surface to form immunocomplexes for first signal amplification and the initiator allows for on-chip ATRP of 2-hydroxyethyl methacrylate (HEMA) from the AuNPs to further enhance the SPRi signal. High sensitivity and broad dynamic range are achieved with this dual signal amplification strategy for detection of a model tumor marker, α-fetoprotein (AFP), in 10% human serum. 相似文献
60.
Aharoni A Thieme K Chiu CP Buchini S Lairson LL Chen H Strynadka NC Wakarchuk WW Withers SG 《Nature methods》2006,3(8):609-614
Engineering of glycosyltransferases (GTs) with desired substrate specificity for the synthesis of new oligosaccharides holds great potential for the development of the field of glycobiology. However, engineering of GTs by directed evolution methodologies is hampered by the lack of efficient screening systems for sugar-transfer activity. We report here the development of a new fluorescence-based high-throughput screening (HTS) methodology for the directed evolution of sialyltransferases (STs). Using this methodology, we detected the formation of sialosides in intact Escherichia coli cells by selectively trapping the fluorescently labeled transfer products in the cell and analyzing and sorting the resulting cell population using a fluorescence-activated cell sorter (FACS). We screened a library of >10(6) ST mutants using this methodology and found a variant with up to 400-fold higher catalytic efficiency for transfer to a variety of fluorescently labeled acceptor sugars, including a thiosugar, yielding a metabolically stable product. 相似文献