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951.
本文简要介绍了叶围烟煤菌的研究概况,报道了采自广东省境内的叶围烟煤菌5科11属29种,其中23种为我国新记录种.所有标本保存于广东省微生物研究所。 相似文献
952.
十二指肠上皮细胞转铁蛋白受体表达调控的免疫组织化学观察与铁吸收机制的探讨 总被引:1,自引:0,他引:1
转铁蛋白受体(TfR)在细胞的铁转运方面起重要作用。本研究用免疫组织化学法比较铁缺乏(甲组)、铁过剩(乙组)与对照组(丙组)Wistar系大鼠活体十二指肠上皮细胞TfR的表达调控及其在铁吸收过程中的意义。结果表明:甲组十二指肠上皮细胞内TfR表达明显强于雨组,乙组TfR表达最弱。可见TfR的表达在一定范围内随体内铁含量的增高或降低而减弱或增强,受铁状态的负调节。丙组TfR主要位于细胞基底部,游离面TfR表达不明显。甲组细胞TfR表达增强,基底部可见线状TfR高强度表达。乙组虽TfR表达明显减弱,但在细胞基底部仍可见线状TfR表达。提示十二指肠上皮细胞基底部有TfR介导的铁转运,而铁从上皮的游离面进入细胞内并非由TfR介导。三组动物小肠粘膜固有层中均可见TfR阳性的巨噬细胞。在铁过剩组、此巨噬细胞数量增加,且TfR表达未受明显抑制。认为铁过剩时,粘膜固有层的巨噬细胞内可贮存过量的铁,减少其对实质细胞、组织的损伤。 相似文献
953.
Zhenli Sun Yahong Lu Hao Zhang Dhiraj Kumar Bo Liu Yongchang Gong Min Zhu Liyuan Zhu Zi Liang Sulan Kuang Fei Chen Xiaolong Hu Guangli Cao Renyu Xue Chengliang Gong 《PloS one》2016,11(1)
The gut microbiota has a crucial role in the growth, development and environmental adaptation in the host insect. The objective of our work was to investigate the microbiota of the healthy silkworm Bombyx mori gut and changes after the infection of B. mori cypovirus (BmCPV). Intestinal contents of the infected and healthy larvae of B. mori of fifth instar were collected at 24, 72 and 144 h post infection with BmCPV. The gut bacteria were analyzed by pyrosequencing of the 16S rRNA gene. 147(135) and 113(103) genera were found in the gut content of the healthy control female (male) larvae and BmCPV-infected female (male) larvae, respectively. In general, the microbial communities in the gut content of healthy larvae were dominated by Enterococcus, Delftia, Pelomonas, Ralstonia and Staphylococcus, however the abundance change of each genus was depended on the developmental stage and gender. Microbial diversity reached minimum at 144 h of fifth instar larvae. The abundance of Enterococcus in the females was substantially lower and the abundance of Delftia, Aurantimonas and Staphylococcus was substantially higher compared to the males. Bacterial diversity in the intestinal contents decreased after post infection with BmCPV, whereas the abundance of both Enterococcus and Staphylococcus which belongs to Gram-positive were increased. Therefore, our findings suggested that observed changes in relative abundance was related to the immune response of silkworm to BmCPV infection. Relevance analysis of plenty of the predominant genera showed the abundance of the Enterococcus genus was in negative correlation with the abundance of the most predominant genera. These results provided insight into the relationship between the gut microbiota and development of the BmCPV-infected silkworm. 相似文献
954.
Yumei Zhang Yu Pan Zhixiang Bian Peihua Chen Shijian Zhu Huiyi Gu Liping Guo Chun Hu 《PloS one》2016,11(1)
Here, we studied the underlying mechanism of aldosterone (Aldo)-induced vascular endothelial cell damages by focusing on ceramide. We confirmed that Aldo (at nmol/L) inhibited human umbilical vein endothelial cells (HUVEC) survival, and induced considerable cell apoptosis. We propose that ceramide (mainly C18) production might be responsible for Aldo-mediated damages in HUVECs. Sphingosine-1-phosphate (S1P), an anti-ceramide lipid, attenuated Aldo-induced ceramide production and following HUVEC damages. On the other hand, the glucosylceramide synthase (GCS) inhibitor PDMP or the ceramide (C6) potentiated Aldo-induced HUVEC apoptosis. Eplerenone, a mineralocorticoid receptor (MR) antagonist, almost completely blocked Aldo-induced C18 ceramide production and HUVEC damages. Molecularly, ceramide synthase 1 (CerS-1) is required for C18 ceramide production by Aldo. Knockdown of CerS-1 by targeted-shRNA inhibited Aldo-induced C18 ceramide production, and protected HUVECs from Aldo. Reversely, CerS-1 overexpression facilitated Aldo-induced C18 ceramide production, and potentiated HUVEC damages. Together, these results suggest that C18 ceramide production mediates Aldo-mediated HUVEC damages. MR and CerS-1 could be the two signaling molecule regulating C18 ceramide production by Aldo. 相似文献
955.
956.
厦门同安湾定置网捕获鱼类的多样性及营养级特征 总被引:1,自引:0,他引:1
利用2012年4月至2013年3月在同安湾进行的定置网渔业资源调查资料, 探讨了该海域鱼类多样性及平均营养级特征。结果表明, 周年逐月共鉴定鱼类112种, 隶属于15目53科88属。渔获物组成以沿岸小型底层鱼类为主, 其中中上层鱼类15种, 中下层鱼类18种, 底层鱼类79种; 暖水性种类84种, 暖温性种类28种, 亚热带动物区系特征明显; 杂食性鱼类8种, 低级肉食性鱼类71种, 中级肉食性鱼类30种, 高级肉食性鱼类3种, 以低级肉食性鱼类为主。中华海鲶(Tachysurus sinensis)是夏、秋、冬三季的优势种, 六指多指马鲅(Polydactylus sextarius)、锯脊塘鳢(Butis koilomatodon)和髭缟鰕虎鱼(Tridentiger barbatus)是春、冬两季的优势种。重量和尾数多样性指数最高值均在11月, 分别为3.26和3.29; 最低值均在2月, 分别为1.78和1.77。鱼类种类存在明显的季节更替现象, 其月更替率6月最低, 为40.1%; 3月最高, 达68.6%。鱼类平均营养级也存在明显的季节变化, 其中3月最低, 为3.02; 1月最高, 为3.92; 周年平均营养级为3.52。与2003年调查资料相比, 鱼类种类数明显减少, 鱼类组成和优势种发生了很大的变化, 导致变化的主要原因可能是过度捕捞、栖息地破坏和环境污染等。 相似文献
957.
Five new and seven known mono‐sesquiterpenoids ( 1 – 5 and 6 – 12 , resp.) together with five known lindenane‐type disesquiterpenoids, 13 – 17 , were isolated from the whole plant of Chloranthus henryi. Based on spectroscopic methods, the new structures were established to be (5S,6R,8S,10R)‐6‐hydroxyeudesma‐4(15),7(11)‐diene‐12,8‐olide ( 1 ), 6α‐hydroxyeudesma‐4(15),7(11),8(9)‐triene‐12,8‐olide ( 2 ), 8,12‐epoxy‐1β‐hydroxyeudesma‐4(15),7,11‐trien‐6‐one ( 3 ), 12‐oxochloraniolide A ( 4 ), and (4α)‐8‐hydroxy‐12‐norcardina‐6,8,10‐trien‐11‐one ( 5 ), respectively. Among the isolates, compound 2 , zederone epoxide ( 8 ), spicachlorantin G ( 13 ), chloramultilide A ( 14 ), shizukaol B ( 15 ), and spicachlorantin B ( 17 ) showed significant anti‐neuroinflammatory effects by inhibiting nitric‐oxide (NO) production in lipopolysaccharide (LPS)‐stimulated murine BV‐2 microglial cells with relatively low cytotoxicity. 相似文献
958.
959.
960.
Single‐Crystalline Ultrathin Co3O4 Nanosheets with Massive Vacancy Defects for Enhanced Electrocatalysis 下载免费PDF全文
Zhao Cai Yongmin Bi Enyuan Hu Wen Liu Nico Dwarica Yang Tian Xiaolin Li Yun Kuang Yaping Li Xiao‐Qing Yang Hailiang Wang Xiaoming Sun 《Liver Transplantation》2018,8(3)
The role of vacancy defects is demonstrated to be positive in various energy‐related processes. However, introducing vacancy defects into single‐crystalline nanostructures with given facets and studying their defect effect on electrocatalytic properties remains a great challenge. Here this study deliberately introduces oxygen defects into single‐crystalline ultrathin Co3O4 nanosheets with O‐terminated {111} facets by mild solvothermal reduction using ethylene glycol under alkaline condition. As‐prepared defect‐rich Co3O4 nanosheets show a low overpotential of 220 mV with a small Tafel slope of 49.1 mV dec?1 for the oxygen evolution reaction (OER), which is among the best Co‐based OER catalysts to date and even more active than the state‐of‐the‐art IrO2 catalyst. Such vacancy defects are formed by balancing with reducing environments under solvothermal conditions, but are surprisingly stable even after 1000 cycles of scanning under OER working conditions. Density functional theory plus U calculation attributes the enhanced performance to the oxygen vacancies and consequently exposed second‐layered Co metal sites, which leads to the lowered OER activation energy of 2.26 eV and improved electrical conductivity. This mild solvothermal reduction concept opens a new door for the understanding and future designing of advanced defect‐based electrocatalysts. 相似文献