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1.
佛洞地遗址位于云南省临沧市耿马傣族佤族自治县勐简乡勐简村大军赛村民小组燕子洞,坐落于一处东南开口的二叠纪灰岩穿洞,南临南汀河。2016~2017年,临沧市文物管理所在公路考古调勘期间发现该遗址;为进一步认识滇西地区旧石器时代晚期文化,2017~2018年对该遗址开展考古发掘工作。发掘区域位于洞内第四台面到第五台面间,共发掘20 m2,出土了包括石制品、动植物化石等在内的大量遗物。初步地层年代学分析显示,遗址时代为距今18400~14000年,共包含3期连续文化,文化遗物以石制品为主,总数达到9735件。佛洞地遗址作为一处热带-亚热带生境下的史前遗址,为我们构建旧石器时代晚期滇西地区文化序列、探讨特定自然生态背景下史前人类的文化适应提供了重要参考。  相似文献   
2.
为探讨无乳链球菌对四环素类的敏感性及其与耐药基因、多位点序列分型(multilocus sequence typing,MLST)之间的关系,本研究收集2014—2017年深圳市南山区人民医院分离自患者的136株无乳链球菌临床分离株,采用琼脂平板稀释法分析四环素类最低抑菌浓度(minimum inhibitory co...  相似文献   
3.
More than 170 million individuals worldwide are infected with hepatitis C virus (HCV), and up to an estimated 30% of chronically infected individuals will go on to develop progressive liver disease. Despite the recent advances in antiviral treatment of HCV infection, it remains a major public health problem. Thus, development of an effective vaccine is urgently required. In this study, we constructed novel adeno-associated virus (AAV) vectors expressing the full-length NS3 or NS3/4 protein of HCV genotype 1b. The expression of the NS3 or NS3/4 protein in HepG2 cells was confirmed by western blotting. C57BL/6 mice were intramuscularly immunised with a single injection of AAV vectors, and the resultant immune response was investigated. The AAV2/rh32.33.NS3/4 vaccine induced stronger humoral and cellular responses than did the AAV2/rh32.33.NS3 vaccine. Our results demonstrate that AAV-based vaccines exhibit considerable potential for the development of an effective anti-HCV vaccine.  相似文献   
4.
Introduction: It has been suggested that allergies are inversely associated with glioma risk. Single nucleotide polymorphisms in two allergy-related genes [interleukin (IL)-4Rα, IL-13] have been implicated in susceptibility to glioma; however, results from the published studies remained inconclusive. Methods: To derive a more precise relationship, we conducted a meta-analysis including seven case–control studies that investigated the influence of IL-4Rα rs1801275 and IL13 rs20541 polymorphisms on glioma risk. Data were extracted from these studies and pooled odds ratios (OR) with 95% confidence intervals (CI) were used to investigate the strength of the association. Results: Overall, the pooled analysis showed that there was no significant association between the IL-4Rα rs1801275 polymorphism and glioma risk (OR = 0.99, 95%CI: 0.79–1.25, AG/GG vs. AA). However, we found that the IL13 rs20541 variant genotypes (GA/AA) were significantly associated with reduced risk for glioma (OR = 0.85, 95%CI: 0.75–0.97, GA/AA vs. GG). In the stratified analyses by ethnicity, marginally significant association between the IL13 rs20541 polymorphism and decreased glioma risk was found among Asian populations in dominant models (OR = 0.84, 95%CI: 0.70–1.00, GA/AA vs. GG). Conclusions: This meta-analysis suggests that the IL13 rs20541 but not the IL-4Rα rs1801275 polymorphism may be a genetic predictor for glioma. More studies with larger sample size are warranted to further elucidate the impact of the IL13 rs20541 polymorphism on glioma risk.  相似文献   
5.
Current methods to derive induced pluripotent stem cell (iPSC) lines from human dermal fibroblasts by viral infection rely on expensive and lengthy protocols. One major factor contributing to the time required to derive lines is the ability of researchers to identify fully reprogrammed unique candidate clones from a mixed cell population containing transformed or partially reprogrammed cells and fibroblasts at an early time point post infection. Failure to select high quality colonies early in the derivation process results in cell lines that require increased maintenance and unreliable experimental outcomes. Here, we describe an improved method for the derivation of iPSC lines using fluorescence activated cell sorting (FACS) to isolate single cells expressing the cell surface marker signature CD13NEGSSEA4POSTra-1-60POS on day 7–10 after infection. This technique prospectively isolates fully reprogrammed iPSCs, and depletes both parental and “contaminating” partially reprogrammed fibroblasts, thereby substantially reducing the time and reagents required to generate iPSC lines without the use of defined small molecule cocktails. FACS derived iPSC lines express common markers of pluripotency, and possess spontaneous differentiation potential in vitro and in vivo. To demonstrate the suitability of FACS for high-throughput iPSC generation, we derived 228 individual iPSC lines using either integrating (retroviral) or non- integrating (Sendai virus) reprogramming vectors and performed extensive characterization on a subset of those lines. The iPSC lines used in this study were derived from 76 unique samples from a variety of tissue sources, including fresh or frozen fibroblasts generated from biopsies harvested from healthy or disease patients.  相似文献   
6.
Earlier studies have demonstrated that aldose reductase (AR) plays a key role in mediating ischemia-reperfusion (I/R) injury. Our objective was to investigate if AR mediates I/R injury by influencing phosphorylation of glycogen synthase kinase-3β (p-GSK3β). To investigate this issue, we used three separate models to study the effects of stress injury on the heart. Hearts isolated from wild-type (WT), human expressing AR transgenic (ARTg), and AR knockout (ARKO) mice were perfused with/without GSK3β inhibitors (SB-216763 and LiCl) and subjected to I/R. Ad-human AR (Ad-hAR)-expressing HL-1 cardiac cells were exposed to hypoxia (0.5% O(2)) and reoxygenation (20.9% O(2)) conditions. I/R in a murine model of transient occlusion and reperfusion of the left anterior descending coronary artery (LAD) was used to study if p-GSK3β was affected through increased AR flux. Lactate dehydrogenase (LDH) release and left ventricular developed pressure (LVDP) were measured. LVDP was decreased in hearts from ARTg mice compared with WT and ARKO after I/R, whereas LDH release and apoptotic markers were increased (P < 0.05). p-GSK3β was decreased in ARTg hearts compared with WT and ARKO (P < 0.05). In ARKO, p-GSK3β and apoptotic markers were decreased compared with WT (P < 0.05). WT and ARTg hearts perfused with GSK3β inhibitors improved p-GSK3β expression and LVDP and exhibited decreased LDH release, apoptosis, and mitochondrial pore opening (P < 0.05). Ad-hAR-expressing HL-1 cardiac cells, exposed to hypoxia (0.5% O(2)) and reoxygenation (20.9% O(2)), had greater LDH release compared with control HL-1 cells (P < 0.05). p-GSK3β was decreased and correlated with increased apoptotic markers in Ad-hAR HL-1 cells (P < 0.05). Treatment with phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) inhibitor increased injury demonstrated by increased LDH release in ARTg, WT, and ARKO hearts and in Ad-hAR-expressing HL-1 cells. Cells treated with protein kinase C (PKC) α/β inhibitor displayed significant increases in p-Akt and p-GSK3β expression, and resulted in decreased LDH release. In summary, AR mediates changes in p-GSK3β, in part, via PKCα/β and Akt during I/R.  相似文献   
7.
Himalayan hemlock (Tsuga dumosa) experienced a recolonization event during the Quaternary period; however, the specific dispersal routes are remain unknown. Recently, the least cost path (LCP) calculation coupled with population genetic data and species distribution models has been applied to reveal the landscape connectivity. In this study, we utilized the categorical LCP method, combining species distribution of three periods (the last interglacial, the last glacial maximum, and the current period) and locality with shared chloroplast, mitochondrial, and nuclear haplotypes, to identify the possible dispersal routes of T. dumosa in the late Quaternary. Then, both a coalescent estimate of migration rates among regional groups and establishment of genetic divergence pattern were conducted. After those analyses, we found that the species generally migrated along the southern slope of Himalaya across time periods and genomic makers, and higher degree of dispersal was in the present and mtDNA haplotype. Furthermore, the direction of range shifts and strong level of gene flow also imply the existence of Himalayan dispersal path, and low area of genetic divergence pattern suggests that there are not any obvious barriers against the dispersal pathway. Above all, we inferred that a dispersal route along the Himalaya Mountains could exist, which is an important supplement for the evolutionary history of T. dumosa. Finally, we believed that this integrative genetic and geospatial method would bring new implications for the evolutionary process and conservation priority of species in the Tibetan Plateau.  相似文献   
8.
Tissue engineering has brought new possibilities for the treatment of spinal cord injury. Two important components for tissue engineering of the spinal cord include a suitable cell source and scaffold. In our study, we investigated induced mouse embryonic fibroblasts (MEFs) directly reprogrammed into neural stem cells (iNSCs), as a cell source. Three-dimensional (3D) electrospun poly (lactide-co-glycolide)/polyethylene glycol (PLGA-PEG) nanofiber scaffolds were used for iNSCs adhesion and growth. Cell growth, survival and proliferation on the scaffolds were investigated. Scanning electron microcopy (SEM) and nuclei staining were used to assess cell growth on the scaffolds. Scaffolds with iNSCs were then transplanted into transected rat spinal cords. Two or 8 weeks following transplantation, immunofluorescence was performed to determine iNSC survival and differentiation within the scaffolds. Functional recovery was assessed using the Basso, Beattie, Bresnahan (BBB) Scale. Results indicated that iNSCs showed similar morphological features with wild-type neural stem cells (wt-NSCs), and expressed a variety of neural stem cell marker genes. Furthermore, iNSCs were shown to survive, with the ability to self-renew and undergo neural differentiation into neurons and glial cells within the 3D scaffolds in vivo. The iNSC-seeded scaffolds restored the continuity of the spinal cord and reduced cavity formation. Additionally, iNSC-seeded scaffolds contributed to functional recovery of the spinal cord. Therefore, PLGA-PEG scaffolds seeded with iNSCs may serve as promising supporting transplants for repairing spinal cord injury (SCI).  相似文献   
9.
土壤中重金属形态分析及其环境学意义   总被引:112,自引:6,他引:112  
介绍了土壤重金属的形态及各种分析方法,重点说明了土壤中重金属形态分布及影响因素;讨论了影响土壤环境中重金属形态转化的因素,重金属形态与重金属在土壤中的迁移性、可给性、活性的关系,重金属污染土壤修复与重金属形态分布的关系.形态分析在一定程度上反映自然与人为作用对土壤中重金属来源的贡献,并反映重金属的生物毒性.重金属可以因形态中某一个或几个方面不同而表现出不同的毒性和环境行为.  相似文献   
10.
基于等级层次分析法的金沙江下游地区生态功能分区   总被引:5,自引:0,他引:5  
金沙江下游地区是我国西南重要的生态环境保护区域,也是我国未来水电建设的重要区域,在西南民族经济和区域可持续发展等方面都具有十分重要的战略意义。该地区水能资源开发潜力巨大,是我国重要的能源基地,但是该地区生态环境相对脆弱。为了保护这些脆弱生态环境的地区,尽管国家和大多数省级层次的生态功能分区已经制定并颁布和实施,但是如何探索和制定区域、流域尺度的生态功能分区研究却为数不多。而大尺度的生态功能分区研究并不一定非常适合这一具体流域实际情况,所以小尺度典型流域的生态功能分区探索是非常必要的。基于金沙江下游地区的生态环境特征,运用空间分析的方法和技术,采用定性和定量分析相结合的等级层次分析法,对金沙江下游地区进行了生态功能分区。结果表明:金沙江下游地区可划分为2个生态区、6个生态亚区和29个生态功能区;以流域尺度上水源涵养、水土保持和生物多样性保护为主导生态系统功能,进行了重要生态功能分区,确定了金沙江下游地区具有重要意义的19个重要生态功能区域。该重点区域的划分对金沙江下游地区生态安全具有重要生态意义,可用于指导金沙江下游地区自然资源的有序开发利用和产业布局的合理配置,为金沙江下游地区生态环境保护提供科学依据,对维护金沙江下游地区的水电生态安全提供重要指导。  相似文献   
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