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191.
192.
Central nervous system (CNS) maintains a high level of metabolism, which leads to the generation of large amounts of free radicals, and it is also one of the most vulnerable organs to oxidative stress. Emerging evidences have shown that, as the key homeostatic cells in CNS, astrocytes are deeply involved in multiple aspects of CNS function including oxidative stress regulation. Besides, the redox level in CNS can in turn affect astrocytes in morphology and function. The complex and multiple roles of astrocytes indicate that their correct performance is crucial for the normal functioning of the CNS, and its dysfunction may result in the occurrence and progression of various neurological disorders. To date, the influence of astrocytes in CNS oxidative stress is rarely reviewed. Therefore, in this review we sum up the roles of astrocytes in redox regulation and the corresponding mechanisms under both normal and different pathological conditions.  相似文献   
193.
进化历史和气候条件共同影响中国木本植物花色的分布 本研究以中国木本植物为研究对象,主要探讨两个问题:(1)不同生活型物种花色组成的差异;(2)生物地理区、进化年龄和气候条件对不同花色地理分布格局的影响。研究使用7673种木本植物的物种分布数据和花色信息(分为白色、红色、黄色、黄绿色、绿色和蓝紫色),并结合属级系统进化树来比较不同生活型(包括灌木、乔木和藤本)物种花色组成的差异,分析不同生物地理区、进化年龄和现代气候对花色地理格局的影响。研究结果表明,与乔木和藤本植物相比,灌木具有更高比例 的由花青素着色的红色花和蓝紫色花物种。中国木本植物的花色地理格局受到区域效应和现代气候(尤其是降水和UVB辐射)的共同影响。倾向于蜂媒传粉的黄色花和蓝紫色花物种和由花青素着色、耐环境胁迫的红色花和蓝紫色花物种比例在中国西北部地区更高。绿色花物种的进化起源更早,但进化时间对花色地理格局的解释力很弱。这些结果说明中国木本植物花色的地理格局受到进化历史和现代环境的共同影响。  相似文献   
194.
以飞龙掌血(Toddalia asiatica(L.)Lam.)的根为实验材料,以总生物碱的含量为检测指标,应用响应面法对飞龙掌血中总生物碱的提取工艺进行了优化。结果显示,当提取条件为乙醇体积分数74.76%、料液比20∶1和提取时间32.87 min时,飞龙掌血提取物中总生物碱的理论含量值可达11.09 mg/g,总生物碱含量达到最高值。按照最佳提取工艺条件进行验证,3次平行实验的均值为(10.74 ±0.18)mg/g,与理论值差异较小,表明利用响应面法来优化飞龙掌血中总生物碱的最佳提取工艺模型拟合良好,具有一定实用价值。  相似文献   
195.
Pancreatic ductal adenocarcinoma (PDAC) is an invasive and aggressive cancer that remains a major threat to human health across the globe. Despite advances in cancer treatments and diagnosis, the prognosis of PDAC patients remains poor. New and more effective PDAC therapies are therefore urgently required. In this study, we identified a novel host factor, namely the LncRNA TP73-AS1, as overexpressed in PDAC tissues compared to adjacent healthy tissue samples. The overexpression of TP-73-AS1 was found to correlate with both PDAC stage and lymph node metastasis. To reveal its role in PDCA, we targeted TP73-AS1 using LnRNA inhibitors in a range of pancreatic cancer (PC) cell lines. We found that the inhibition of TP73-AS1 led to a loss of MMP14 expression in PC cells and significantly inhibited their migratory and invasive capacity. No effects of TP73-AS1 on cell survival or proliferation were observed. Mechanistically, we found that TP73-AS1 suppressed the expression of the known oncogenic miR-200a. Taken together, these data highlight the prognostic potential of TP73-AS1 for PC patients and highlight it as a potential anti-PDAC therapeutic target.  相似文献   
196.
Advances in high-throughput sequencing(HTS)have fostered rapid developments in the field of microbiome research,and massive microbiome datasets are now being generated.However,the diversity of software tools and the complexity of analysis pipelines make it difficult to access this field.Here,we systematically summarize the advantages and limitations of micro-biome methods.Then,we recommend specific pipelines for amplicon and metagenomic analyses,and describe commonly-used software and databases,to help researchers select the appropriate tools.Furthermore,we introduce statistical and visualization methods suit-able for microbiome analysis,including alpha-and beta-diversity,taxonomic composition,difference compar-isons,correlation,networks,machine learning,evolu-tion,source tracing,and common visualization styles to help researchers make informed choices.Finally,a step-by-step reproducible analysis guide is introduced.We hope this review will allow researchers to carry out data analysis more effectively and to quickly select the appropriate tools in order to efficiently mine the bio-logical significance behind the data.  相似文献   
197.
198.
Parental age at first pregnancy is increasing worldwide. The offspring of aged father has been associated with higher risk of several neuropsychiatric disorders, such as schizophrenia and autism, but the underlying mechanism remains elusive. Here we report that advanced paternal age in mice alters the profile of transfer RNA‐derived small RNAs (tsRNAs). Injection of sperm tsRNAs from aged male mice into zygotes induced anxiety‐like behaviors in F1 males. RNA sequencing of the cerebral cortex and hippocampus of those F1 male mice altered the gene expression of dopaminergic synapse and neurotrophin. tsRNAs from aged male mice injection also altered the neuropsychiatry‐related gene expression in two‐cell and blastocyst stage embryos. More importantly, the sperm tsRNA profile changes significantly during aging in human. The up‐regulated sperm tsRNA target genes were involved in neurogenesis and nervous system development. These results suggest that aging‐related changes of sperm tsRNA may contribute to the intergenerational transmission of behavioral traits.  相似文献   
199.
Mikania micrantha (Asteraceae) is one of the 10 most invasive weeds in the world and has caused tremendous economic and environmental losses in southern China. The dodder Cuscuta campestris (Convolvulaceae) is a native holoparasite that can parasitize and suppress M. micrantha, and thus is recommended as an effective control agent. However, the natural growth of dodder lags behind that of M. micrantha and fails to exert direct year-round suppression. To verify the effective parasitic distance, we placed a dodder seedling at a designated distance from the stem of M. micrantha and monitored coiling, haustorium formation, and survival. To verify suitable host stems for the parasite, we grew M. micrantha for more than 6 months to form stems of different sizes, taped dodder seedlings to the stems, and monitored. We used various temperatures to determine the effect on dodder seed germination and M. micrantha sprouting. The results showed that a dodder–host distance of 4 cm decreased the probability of successful parasitism to 0; dodder seedlings cannot parasitize M. micrantha stem diameters ≥0.3 cm; and the temperatures for the highest dodder seed germination and M. micrantha sprouting are 26 and 30 °C, respectively. We conclude that the lack of suitable M. micrantha parts within the dodder’s effective parasitism distance is the major cause of restricted dodder parasitism and that the lower temperature for the highest dodder germination compared to that for the highest M. micrantha sprouting may decrease the possibility of parasitism. To acquire aggressive parasitism, dodder should be manually assisted by dispersing its vegetative form.  相似文献   
200.
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