排序方式: 共有147条查询结果,搜索用时 625 毫秒
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胰腺是一个重要的内外分泌混合腺, 胰腺发生损伤后能够再生。为了探讨胰腺活体细胞世系追踪的方法和胰腺损伤后再生细胞的来源,分别通过胰腺伤口涂抹并胰内注射、尾静脉注射及腹腔注射三种方法, 利用假型反转录病毒对成体小鼠大部分切除后胰腺的细胞进行世系追踪。结果发现在活体条件下, 与尾静脉注射及腹腔注射法相比, 胰腺伤口涂抹并胰腺内注射反转录病毒的方法能够更有效的标记胰腺细胞; 而且, 通过对标记细胞的世系追踪研究证明, 在胰腺损伤后, 胰腺腺泡细胞能够接受损伤信号刺激发生再生。为今后进一步利用反转录假病毒对活体胰腺进行细胞命运追踪研究奠定基础, 为利用反转录病毒载体进行胰腺疾病的基因治疗提供线索。 相似文献
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Chunbo Hao Hongxun Zhang Richard Haas Zhihui Bai Baoguo Zhang 《World journal of microbiology & biotechnology》2007,23(1):15-21
A sediment sample (pH 2.5) was collected at an acid mine drainage site in Anhui, China. The present acidophilic microbial
community in the sediment was studied with a 16S rRNA gene clone library. Small-subunit rRNA genes were PCR amplified, cloned
and screened by amplified rDNA restriction analysis (ARDRA). Subsequently, 10 different clones were identified and they were
affiliated with Acidobacteria, β/γ-Proteobacteria, δ-Proteobacteria, Nitrospira, Candidate division TM7, and Low G + C Gram-positives. Phylogenetic analysis of 16S rRNA gene sequences revealed a diversity
of acidophiles in the sediment that were mostly novel. Unexpectedly, 16S rRNA gene sequences affiliated with δ-Proteobacteria were found to constitute more than 60% of clone library. To our knowledge, this is the first occasion that bacteria of δ-Proteobacteria have been found dominant in the acidic habitat. Anaerobic sulfate- or metal reduction is the predominant physiological trait
of bacteria of this subdivision. The high sulfate, ferric iron and the presence of bioavailable carbon in the anaerobic microenvironment
may result in the dominance of bacteria of δ-Proteobacteria. 相似文献
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1981-2018年新疆草地归一化植被指数时空特征及其对气候变化的响应 总被引:1,自引:0,他引:1
在新疆开展长时间序列的草地监测,分析草地生长的时空变化特征,有利于草地环境压力分析和草地生态健康预测。以NOAA-AVHRR NDVI为数据源,采用最大值合成、一元回归分析与相关性分析,分别在年际尺度和多个空间尺度(全疆、南北疆与各地区及其11种草地类型)上探讨了1981—2018年新疆草地归一化植被指数(NDVI)时空特征及其对气温、降水的响应。结果表明:(1)1981—2018年,新疆草地NDVI多年均值0.326,变化范围0.259—0.386,具有轻微年际波动特征;(2)北疆、南疆草地NDVI均表现为轻微增加趋势;全疆占草地总面积41%的区域NDVI呈显著增加趋势,9%为显著减少区域,北疆草地NDVI显著增加的面积是南疆的1.7倍;(3)由于垂直地带性及区域差异,新疆草地NDVI由山区向盆地的荒漠降低;北疆草地NDVI是南疆1.4倍,总体上北疆各地区草地NDVI高于南疆各地区;(4)草地类型植被NDVI对降水的显著响应高于气温,其中温性荒漠类、温性荒漠草原类与温性草原类草地NDVI对降水变化的响应明显高于其余草地类型,降水对草地NDVI的影响更为显著,表明降水引起的地表水分变化... 相似文献
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Chunmei Zhang Xueju Zhang Chunbo Liu Junfeng Wang Xinghan Liu Hulun Li Jinghua Wang Changjun Wu 《Molecular biology reports》2010,37(4):1755-1762
Ultrasound (US)-mediated microbubble destruction is recognized to have considerable potential for gene delivery, whereas,
there is few report of its effect on enhancing liposomal transfection. In this study, we used pIRES2-EGFP/hES containing human
endostatin (hES) cDNA as target gene to test the hypothesis that US exposure with microbubbles could improve liposomal transfection,
and to investigate the possibility of intracellular delivery of ES gene using this method. Under the controlled US exposure
condition with microbubbles, the plasmid:liposome was transferred into COS-7 cells. The transfection rate, the expression
of endostatin and the inhibition effect of transfection-endostatin on endothelial cells were assessed. The results revealed
that US-mediated microbubble destruction together with liposome could significantly enhance gene transfection without obvious
cell damage. By this means, endostatin gene could be efficiently transferred into COS-7 cells and expressed. The transfection-endostatin
could inhibit endothelial proliferation and migration, which suggests that the non-viral method might be useful in anti-angiogenesis
therapy in the future. 相似文献
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