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1.
绞股蓝属的染色体研究   总被引:11,自引:2,他引:9  
报道了葫芦科绞股蓝属(Gynostemma B1.)8种共20个居群的染色体数目,分别为2n=22,33,44,66,88多倍体现象极为普遍。两个亚属;绞股蓝亚属(Subgen.Gynostemma)和喙果藤亚属(Subgen.Triostellum)的染色体基数均为X=11,并结合该属植物形态特征、繁殖方式和地理分布,对普遍出现的多倍体现象进行了讨论。  相似文献   
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The enteric serotonin transporter (SERT) plays a critical role in modulating serotonin availability and thus has been implicated in the pathogenesis of various intestinal disorders. To date, SERT expression and function in the human intestine have not been investigated. Current studies were designed to characterize the function, expression, distribution, and membrane localization of SERT in the native human intestine. Real-time PCR studies showed relatively higher SERT mRNA expression in the human small intestine compared with colon (ileum > duodenum > jejunum). Northern blot analysis revealed three mRNA hybridizing species encoding SERT (3.0, 4.9, and 6.8 kb) in the human ileum. Consistent with SERT mRNA expression, SERT immunostaining was mainly detected in the epithelial cells of human duodenal and ileal resected tissues. Notably, SERT expression was localized predominantly to the apical and intracellular compartments and was distributed throughout the crypt-villus axis. Immunoblotting studies detected a prominent protein band ( approximately 70 kDa) in the ileal apical plasma membrane vesicles (AMVs) isolated from mucosa obtained from organ-donor intestine. Functional studies showed that uptake of [(3)H]serotonin (150 nM) in human ileal AMVs was 1) significantly increased in the presence of both Na(+) and Cl(-); 2) inhibited ( approximately 50%) by the neuronal SERT inhibitor, fluoxetine (10 microM) and by unlabeled 5-HT; and 3) exhibited saturation kinetics indicating the presence of a carrier-mediated process. Our studies demonstrated differential expression of SERT across various regions of the human intestine and provide evidence for the existence of a functional SERT capable of removing intraluminal serotonin in human ileal epithelial cells.  相似文献   
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烟草花叶病毒蚕豆株系基因组全序列分析及结构特征   总被引:4,自引:1,他引:3  
根据已报道的TMV-U1株系核苷酸序列合成引物 ,利用RT-PCR技术获得了覆盖整个烟草花叶病毒蚕豆株系 (TMV-B)基因组的cDNA重组克隆 .结合末端测序技术 ,完成了TMV-B全基因组序列测定 .TMV-B全基因组共有 6 395个核苷酸组成 ,包括 4个开读框 (ORF) ,分别编码 1 2 6ku(含 1 1 1 6个氨基酸 )、1 83ku(含 1 6 1 6个氨基酸 )、30ku(含 2 6 8个氨基酸 )和 1 7.5ku蛋白 (含 1 5 9个氨基酸 ) .TMV-B与TMV-U1相比全基因组同源率达 99.4% ,两病毒基因组 5′ ,3′非编码区和CP基因完全相同 .TMV-B与TMV-U1之间在 1 2 6ku蛋白中有 6个氨基酸差异 ,5 4ku蛋白中有 2个差异 ,30ku蛋白中有 3个差异 .对导致TMV-B侵染蚕豆的可能致病机理进行了分析 .  相似文献   
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Elevated CO(2) concentrations (hypercapnia) occur in patients with severe lung diseases. Here, we provide evidence that high CO(2) levels decrease O(2) consumption and ATP production and impair cell proliferation independently of acidosis and hypoxia in fibroblasts (N12) and alveolar epithelial cells (A549). Cells exposed to elevated CO(2) died in galactose medium as well as when glucose-6-phosphate isomerase was knocked down, suggesting mitochondrial dysfunction. High CO(2) levels led to increased levels of microRNA-183 (miR-183), which in turn decreased expression of IDH2 (isocitrate dehydrogenase 2). The high CO(2)-induced decrease in cell proliferation was rescued by α-ketoglutarate and overexpression of IDH2, whereas proliferation decreased in normocapnic cells transfected with siRNA for IDH2. Also, overexpression of miR-183 decreased IDH2 (mRNA and protein) as well as cell proliferation under normocapnic conditions, whereas inhibition of miR-183 rescued the normal proliferation phenotype in cells exposed to elevated levels of CO(2). Accordingly, we provide evidence that high CO(2) induces miR-183, which down-regulates IDH2, thus impairing mitochondrial function and cell proliferation. These results are of relevance to patients with hypercapnia such as those with chronic obstructive pulmonary disease, asthma, cystic fibrosis, bronchopulmonary dysplasia, and muscular dystrophies.  相似文献   
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目的:探讨全面质量管理模式时老年心血管疾病患者的生活质量的改善情况所起的积极作用,为临床护理提供参考。方法:选择2011年2月至2012年12月在我院心血管内科接受住院治疗的老年患者60例,随机分为常规组和全面管理组。常规组采取基础护理模式,全面管理组在常规护理的基础上对患者进行心理干预、健康教育及饮食管理等。对比两组患者干预前后生活质量改善情况,并对护理服务的满意度进行问卷调查。结果:全面管理组患者的生活质量较干预前明显改善,且患者的心理功能、生活能力及社交功能评分均显著优于常规组,差异具有统计学意义(P〈0.05)。全面管理组患者对心理护理、饮食管理、健康教育及护患沟通的满意度均高于常规护理组,差异具有统计学意义(P〈0.05)。结论:采取全面质量管理的模式对老年心血管疾病患者进行康复指导具有显著的效果,可明显改善患者的生活质量,并且能够提高患者对护理服务的满意度,值得临床推广。  相似文献   
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A new species of Phylloscopus warbler, which we name Phylloscopus calciatilis Limestone Leaf Warbler, is described from central and northern Vietnam and central and northern Laos; it probably also breeds in southernmost China. In morphology, the new species is very similar to Sulphur-breasted Warbler Phylloscopus ricketti , but it is smaller with a proportionately larger bill and rounder wing. Its song and calls are diagnostic. Based on mitochondrial and nuclear DNA, the new species is most closely related to P. ricketti and Yellow-vented Warbler Phylloscopus cantator , and it is inferred to be sister to the latter. The mitochondrial divergences between these three species are at the low end of the variation found in other species of Phylloscopus and Seicercus warblers, but greater than in other taxa generally treated as subspecies. Possible introgressive hybridization between the new species and P. ricketti is discussed, but more data are needed to establish whether it does occur and, if it does, to what extent. The new species appears to have a restricted breeding range in limestone karst environments, where it is locally common and therefore not under any immediate threat. In view of the recognition of the new species, all previous records of P. ricketti sensu lato need to be re-evaluated.  相似文献   
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随着科学的发展,人造卫星的发射成功,人类开始迈向空间,为揭示太空的真实情况,国内、外学者已进行了大量的探索工作(鲁子贤 1988)。我们利用我国发射的人造卫星进行了搭载试验。本文报道空间环境对微生物生长与遗传性状影响的  相似文献   
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Phloem injury triggers local sieve-plate occlusion including callose-mediated constriction and protein plugging of sieve pores. In intact plants, reversible sieve-plate occlusion is induced by electric potential waves (EPWs)—accompanied by Ca2+-influx—as result of distant burning. Here, we present additional results which pertain to (a) the variability of EPW-profiles in relation to forisome conformation in intact Vicia faba plants and (b) the differential occlusion reactions to burning and cutting in various plant species. A correlation between stimulus perception and mode of phloem loading is discussed.Key words: callose, electrical potential waves, forisome, membrane potential, phloem transport, sieve-element occlusion, wound potentials  相似文献   
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