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271.
Li-Li Zhao Tong Zhang Li-Wei Zhuang Bing-Zhu Yan Rui-Feng Wang Bing-Rong Liu 《Molecular biology reports》2014,41(7):4697-4704
Pancreatic cancer is a uniformly lethal disease that can be difficult to diagnose at its early stage. Thus, our present study aimed to explore the underlying mechanism and identify new targets for this disease. The data GSE16515, including 36 tumor and 16 normal samples were available from Gene Expression Omnibus. Differentially expressed genes (DEGs) were screened out using Robust Multichip Averaging and LIMMA package. Moreover, gene ontology and pathway enrichment analyses were performed to DEGs. Followed with protein–protein interaction (PPI) network construction by STRING and Cytoscape, module analysis was conducted using ClusterONE. Finally, based on PubMed, text mining about these DEGs was carried out. Total 274 up-regulated and 93 down-regulated genes were identified as the common DEGs and these genes were discovered significantly enriched in cell adhesion and extracellular region terms, as well as ECM-receptor interaction pathway. In addition, five modules were screened out from the up-regulated PPI network with none in down-regulated network. Finally, the up-regulated genes, including MIA, MET and CEACAMS, and down-regulated genes, such as FGF, INS and LAPP, had the most references in text mining analysis. Our findings demonstrate that the up- and down-regulated genes play important roles in pancreatic cancer development and might be new targets for the therapy. 相似文献
272.
菘蓝多倍体育种的研究 总被引:39,自引:0,他引:39
本文报道药用植物菘蓝(Isatis indigotica Foft.)同源四倍体的诱发、鉴定、选育的研究。用0.05-0.5%浓度的秋水仙碱水溶液处理萌发的种子,或用0.05-0.3%浓度的此溶液处理幼苗的生长点,均可以获得四倍体植株。最适宜的处理时间为6-12小时。除用直接的细胞学技术鉴定多倍体植株外,一些重要的间接鉴定特征,如叶表皮保卫细胞中叶绿体数,花粉沟数可作为鉴定本种多倍体植株的可靠指标。比较了四倍体植株和二倍体亲本的生物学特性。经过数代选育,获得了性状稳定、繁殖力正常、根与叶中活性成分均有较大幅度提高、生产性能良好的品系。 相似文献
273.
Flood control engineering system risk assessment entails fuzziness. An assessment model is developed, based on the improved fuzzy comprehensive assessment method that developed a new index (Sfin ) to judge the assessment class. The model is used to assess the flood control engineering risk of a case in China. The results show that the proposed model in the present article can rationally determine the risk status of a flood control engineering system, and has higher resolution compared to the two conventional methods, fuzzy comprehensive assessment and matter-element model method. The proposed model is flexible and adaptable for determining flood control engineering system risk status. 相似文献
274.
Adiantum reniforme var. sinensis (Adiantaceae) is an endangered fern endemic to the Three Gorges region in southwest China. To elucidate possible ecophysiological mechanisms restricting its distribution, effects of the availability of light (28%, 14% and 7% of open field) and soil moisture (60% and 40% of field capacity) on dry matter production and allocation, leaf morphology and water use efficiency (WUE) were examined in A. reniforme var. sinensis and its widespread congener A. capillus‐veneris. Both species had lower root/shoot ratio (R/S) and higher specific leaf area (SLA) when grown at low light. However, A. reniforme var. sinensis showed less plasticity for total leaf area (LA) and leaf area ratio (LAR) than A. capillus‐veneris, and its root mass, total mass and WUE decreased as light availability decreased. Under water stress, all traits of both species except WUE were significantly affected. However, drought stress decreased total mass of A. capillus‐veneris but did not have a significant effect on A. reniforme var. sinensis. Compared with A. capillus‐veneris, A. reniforme var. sinensis had significantly higher R/S but lower values for other analyzed traits. These results suggest that A. reniforme var. sinensis is relatively superior in drought tolerance but inferior at low light, allowing it to persist in habitats with low soil moisture and high light availability but with few coexisting species present. 相似文献
276.
Wei Wang Huange Xi Qirui Bi Ying Hu Yang Zhang Mengxiang Ni 《Microbiological research》2013,168(6):360-366
d-Aminoacylase catalyzes the conversion of N-acyl-d-amino acids to d-amino acids and fatty acids. The aim of this study was to identify the d-aminoacylase gene from Achromobacter xylosoxidans subsp. denitrificans ATCC 15173 and investigate the biochemical characterization of the enzyme. A previously uncharacterized d-aminoacylase gene (ADdan) from this organism was cloned and sequenced. The open reading frame (ORF) of ADdan was 1467 bp in size encoding a 488-amino acid polypeptide. ADdan, with a high amino acid similarity to N-acyl-d-aspartate amidohydrolase from Alcaligenes A6, showed relatively low sequence similarities to other characterized d-aminoacylases. The recombinant ADdan protein was expressed in Escherichia coli BL21 (DE3) using pET-28a with a T7 promoter. The enzyme was purified in a single chromatographic step using nickel affinity gel column. The molecular mass of the expressed protein, calculated by SDS–PAGE, was about 52 kDa. The purified ADdan showed optimal activity at pH 8.0 and 50 °C, and was stable at pH 6.0–8.0 and up to 45 °C. Its activity was inhibited by Cu2+, Fe2+, Ca2+, Mn2+, Ni2+, Zn2+ and Hg2+, whereas Mg2+ had no significant influence on this recombinant d-aminoacylase. This is the first report on the characterization of d-aminoacylase with activity towards both N-acyl derivatives of neutral d-amino acids and N-acyl-d-aspartate. The characteristics of ADdan could prove to be of interest in industrial production of d-amino acids. 相似文献
277.
鸭源鸡杆菌(Gallibacterium anatis,G.anatis)是家禽中常见的条件性致病菌,主要引起蛋鸡生殖道疾病,造成产蛋量下降。【目的】为探究RTX样毒素GtxA及外膜蛋白(OmpW)对鸭源鸡杆菌生物学特性和致病力的影响。【方法】本研究采用自然转化法对突变株RZ△ompW进一步缺失gtxA构建突变株RZ△ompW△gtxA,通过分析其生长特性、黏附能力、引起细胞凋亡程度及对小鼠致病性等,探究其与生物学特性及致病性可能的关系。【结果】结果显示,RZ△ompW△gtxA能稳定遗传gtxA的缺失;单双基因突变株溶血活性均消失、与RZ株相比菌落形态及生长速率并未出现显著改变;相比RZ、RZ△ompW和RZ△gtxA,双基因缺失株RZ△ompW△gtxA在不同时段对鸡原代输卵管上皮细胞的黏附能力显著降低(P0.05),诱导鸡输卵管上皮原代细胞发生凋亡的能力明显减弱,对小鼠的致病力显著降低。【结论】GtxA毒素和外膜蛋白OmpW在鸭源鸡杆菌毒力、黏附宿主细胞及诱导其细胞凋亡中起重要作用,且可能存在明显的协同关系。本研究为鸭源鸡杆菌感染机制的阐明奠定基础。 相似文献
278.
BiLing Yang Yan Ge Yang Zhou Jia Wang Xi Xie Shu Li Mengshi Tang LiChang Xu Jing Tian 《Cell biochemistry and function》2019,37(4):208-215
Abnormal hyperplasia of fibroblast‐like synoviocytes (FLS) leads to the progression of rheumatoid arthritis (RA). This study aimed to investigate the role of miR‐124a in the pathogenesis of RA. The viability and cell cycle of FLS in rheumatoid arthritis (RAFLS) were evaluated by Cell Counting Kit 8 and flow cytometry assay. The expression of PIK3CA, Akt, and NF‐κB in RAFLS was examined by real‐time PCR and Western blot analysis. The production of tumour necrosis factor (TNF)‐α and interleukin (IL)‐6 was detected by ELISA. The joint swelling and inflammation in collagen‐induced arthritis (CIA) mice were examined by histological and immunohistochemical analysis. We found that miR‐124a suppressed the viability and proliferation of RAFLS and increased the percentage of cells in the G1 phase. miR‐124a suppressed PIK3CA 3'UTR luciferase reporter activity and decreased the expression of PIK3CA at mRNA and protein levels. Furthermore, miR‐124a inhibited the expression of the key components of the PIK3/Akt/NF‐κB signal pathway and inhibited the expression of pro‐inflammatory factors TNF‐α and IL‐6. Local overexpression of miR‐124a in the joints of CIA mice inhibited inflammation and promoted apoptosis in FLS by decreasing PIK3CA expression. In conclusion, miR‐124a inhibits the proliferation and inflammation in RAFLS via targeting PIK3/NF‐κB pathway. miR‐124a is a promising therapeutic target for RA. 相似文献
279.
280.