排序方式: 共有121条查询结果,搜索用时 31 毫秒
1.
研究了层理鞭枝藻藻胆体在不同浓度磷酸缓冲溶液中解离过程中荧光发射光谱的变化和光能传递。完整藻胆体的77K荧光光谱中只有一个峰,位于685nm它是末端发射体(核心-膜连接多肽和别藻蓝蛋白-B)的荧光峰。部分解离藻胆体的荧光光谱的主峰位移至652nm:次峰位于685nm;660nm为一弱荧光发射肩。它们依次为C-藻蓝蛋白,末端发射体和别藻蓝蛋白的荧光。严重解离藻胆体的荧光主峰移644nm;次峰由685nm移至682nm;660nm荧光发射肩消失。这表明C-藻蓝蛋白所捕获的光能已不能传递给别藻蓝蛋白,但可传递给末端发射体洞时又表明C-藻蓝蛋白不仅与别藻蓝蛋白相连接而且还与末端发射体相连接。提出该藻胆体光能传递链如下:核心-膜连接多肽藻红蓝蛋白→C-藻蓝蛋白→别藻蓝蛋白别藻蓝蛋白-B 相似文献
2.
Lei Xu Guang-Chao Zhuang Andrew Montgomery Qianyong Liang Samantha B. Joye Fengping Wang 《Environmental microbiology》2021,23(2):641-651
Methane is a potent greenhouse gas; methane production and consumption within seafloor sediments has generated intense interest. Anaerobic oxidation of methane (AOM) and methanogenesis (MOG) primarily occur at the depth of the sulfate–methane transition zone or underlying sediment respectively. Methanogenesis can also occur in the sulfate-reducing sediments through the utilization of non-competitive methylated compounds; however, the occurrence and importance of this process are not fully understood. Here, we combined a variety of data, including geochemical measurements, rate measurements and molecular analyses to demonstrate the presence of a cryptic methane cycle in sulfate-reducing sediments from the continental shelf of the northern South China Sea. The abundance of methanogenic substrates as well as the high MOG rates from methylated compounds indicated that methylotrophic methanogenesis was the dominant methanogenic pathway; this conclusion was further supported by the presence of the methylotrophic genus Methanococcoides. High potential rates of AOM were observed in the sediments, indicating that methane produced in situ could be oxidized simultaneously by AOM, presumably by ANME-2a/b as indicated by 16S rRNA gene analysis. A significant correlation between the relative abundance of methanogens and methanotrophs was observed over sediment depth, indicating that methylotrophic methanogenesis could potentially fuel AOM in this environment. In addition, higher potential rates of AOM than sulfate reduction rates at in situ methane conditions were observed, making alternative electron acceptors important to support AOM in sulfate-reducing sediment. AOM rates were stimulated by the addition of Fe/Mn oxides, suggesting AOM could be partially coupled to metal oxide reduction. These results suggest that methyl-compounds driven methane production drives a cryptic methane cycling and fuels AOM coupled to the reduction of sulfate and other electron acceptors. 相似文献
3.
Alberto J. León David Banner Luoling Xu Longsi Ran Zhiyu Peng Kang Yi Chao Chen Fengping Xu Jinrong Huang Zhen Zhao Zhen Lin Stephen H. S. Huang Yuan Fang Alyson A. Kelvin Ted M. Ross Amber Farooqui David J. Kelvin 《Journal of virology》2013,87(4):1957-1966
Ferrets have become an indispensable tool in the understanding of influenza virus virulence and pathogenesis. Furthermore, ferrets are the preferred preclinical model for influenza vaccine and therapeutic testing. Here we characterized the influenza infectome during the different stages of the infectious process in ferrets with and without prior specific immunity to influenza. RNA from lung tissue and lymph nodes from infected and naïve animals was subjected to next-generation sequencing, followed by de novo data assembly and annotation of the resulting sequences; this process generated a library comprising 13,202 ferret mRNAs. Gene expression profiles during pandemic H1N1 (pdmH1N1) influenza virus infection were analyzed by digital gene expression and solid support microarrays. As expected during primary infection, innate immune responses were triggered in the lung tissue; meanwhile, in the lymphoid tissue, genes encoding antigen presentation and maturation of effector cells of adaptive immunity increased dramatically. After 5 days postinfection, the innate immune gene expression was replaced by the adaptive immune response, which correlates with viral clearance. Reinfection with homologous pandemic influenza virus resulted in a diminished innate immune response, early adaptive immune gene regulation, and a reduction in clinical severity. The fully annotated ferret infectome will be a critical aid to the understanding of the molecular events that regulate disease severity and host-influenza virus interactions among seasonal, pandemic, and highly pathogenic avian influenzas. 相似文献
4.
滨海白首乌(耳叶牛皮消)药理活性研究进展 总被引:1,自引:0,他引:1
滨海白首乌(耳叶牛皮消)是一种传统中药材,为萝藦科鹅绒藤属植物耳叶牛皮消的块根。耳叶牛皮消具有抗肿瘤、调节免疫、抗氧化、抗衰老、调血脂、促进毛发生长、保护脏器等多种药理活性。本文分析了耳叶牛皮消药理活性,提出了今后耳叶牛皮消研究与开发利用方向。 相似文献
5.
Erpeng Liu Lei Lv Yonghao Zhan Yuan Ma Jinjin Feng Yulin He Yibo Wen Yanping Zhang Qingsong Pu Fengping Ji Xinghuan Yang Jian Guo Wen 《Journal of cellular and molecular medicine》2021,25(16):7660
Renal fibrosis induced by urinary tract obstruction is a common clinical occurrence; however, effective treatment is lacking, and a deeper understanding of the mechanism of renal fibrosis is needed. Previous studies have revealed that miR‐21 impacts liver and lung fibrosis progression by activating the SPRY1/ERK/NF‐kB signalling pathway. However, whether miR‐21 mediates obstructive renal fibrosis through the same signalling pathway has not been determined. Additionally, studies have shown that N6‐methyladenosine (m6A) modification‐dependent primary microRNA (pri‐microRNA) processing is essential for maturation of microRNAs, but its role in the maturation of miR‐21 in obstructive renal fibrosis has not yet been investigated in detail. To address these issues, we employed a mouse model of unilateral ureteral obstruction (UUO) in which the left ureters were ligated for 3, 7 and 14 days to simulate the fibrotic process. In vitro, human renal proximal tubular epithelial (HK‐2) cells were transfected with plasmids containing the corresponding sequence of METTL3, miR‐21‐5p mimic or miR‐21‐5p inhibitor. We found that the levels of miR‐21‐5p and m6A modification in the UUO model groups increased significantly, and as predicted, the SPRY1/ERK/NF‐kB pathway was activated by miR‐21‐5p, confirming that miR‐21‐5p plays an important role in obstructive renal fibrosis by enhancing inflammation. METTL3 was found to play a major catalytic role in m6A modification in UUO mice and drove obstructive renal fibrosis development by promoting miR‐21‐5p maturation. Our research is the first to demonstrate the role of the METTL3‐m6A‐miR‐21‐5p‐SPRY1/ERK/NF‐kB axis in obstructive renal fibrosis and provides a deeper understanding of renal fibrosis. 相似文献
6.
7.
Construction and preliminary analysis of a metagenomic library from a deep-sea sediment of east Pacific Nodule Province 总被引:1,自引:0,他引:1
The Pacific Nodule Province is a unique ocean area containing an abundance of polymetallic nodules. To explore more genetic information and discover potentially industrial useful genes of the microbial community from this particular area, a cosmid library with an average insert of about 35 kb was constructed from the deep-sea sediment. The bacteria in the cosmid library were composed mainly of Proteobacteria including Alphaproteobacteria, Gammaproteobacteria and Deltaproteobacteria. The end sequences of some cosmid clones were determined and the complete insert sequences of two cosmid clones, 10D02 and 17H9, are presented. 10D02 has a length of 40.8 kb and contains 40 predicted encoding genes. It contains a partial 16S rRNA gene of Alphaproteobacteria. 17H9 is 36.8 kb and predicted to have 31 encoding genes and a 16S-23S-5S rRNA gene operon. Phylogenetic analysis of 16S and 23S rRNA gene sequence on the 17H9 both reveals that the inserted DNA from 17H9 came from a novel Alphaproteobacteria and is closely related to Magnetospirillum species. The predicted proteins of ORF 1-11 also have high identity to those of Magnetospirillum species, and the organization of these genes is highly conserved among known Magnetospirillum species. The data suggest that the retrieved DNA in 17H9 might be derived from a novel Magnetospirillum species. 相似文献
8.
Photobacterium damsela is a marine pathogen to both fish and human beings. The bacterium can shift between the ambient seawater and hosts, suggesting the existence of proteins rapidly responding to salt concentration. In the current study, proteomic methodologies were applied to screen the outer membrane proteins (OMPs) related to salt stress. OmpW and OmpV were determined in the response in this bacterium as OmpC and OmpF did in E. coli. Furthermore, the two genes were overexpressed in E. coli Top10F and complemented in V. paraheamolyticus mutants. The ability in salt-tolerance was elevated in the E. coli overexpressed OmpW and reduced in the cells overexpressed OmpV. These V. paraheamolyticus mutants could recover their response to environmental salt concentration when they were complemented by P. damsela OmpW and OmpV. These findings indicate that OmpW and OmpV are required for environmental salt regulation in P. damsela, in which OmpW and OmpV, respectively, elevate and reduce the ability in salinity-tolerance. 相似文献
9.
10.