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口腔各种产黑色素类杆菌外膜结构的电镜观察
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作者 陈晖 苏宇辙 杨圣辉 《中国微生态学杂志》 CAS CSCD 1992年第2期12-15,共4页
本文对从根管中分离的产黑色素类杆菌群的部分菌株:牙髓类杆菌、牙龈类杆菌、中间型类杆菌、产黑色素类杆菌的表面结构进行了电镜观察。观察发现牙髓类杆菌、牙龈类杆菌表面有放射状排列的菌毛样结构;牙龈类杆菌表面有荚膜;多数细菌的... 本文对从根管中分离的产黑色素类杆菌群的部分菌株:牙髓类杆菌、牙龈类杆菌、中间型类杆菌、产黑色素类杆菌的表面结构进行了电镜观察。观察发现牙髓类杆菌、牙龈类杆菌表面有放射状排列的菌毛样结构;牙龈类杆菌表面有荚膜;多数细菌的细胞膜外有多个小泡状结构;这些结构可能在细菌吸附于组织的过程中起着重要的作用。 展开更多
关键词 外膜结构 产黑色素杆菌 口腔细菌
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革兰氏阴性细菌β-桶状结构外膜蛋白体外折叠的研究进展 被引量:3
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作者 代先祝 邵娜娜 罗峰 《微生物学报》 CAS CSCD 北大核心 2014年第11期1241-1247,共7页
除了细胞质膜,革兰氏阴性细菌细胞还有一层组成细胞壁的外膜(Outer Membrane)。膜蛋白是外膜的主要组成成分之一,绝大多数外膜蛋白是由反向平行的β-折叠(β-Strands)通过相邻的氢键结合形成的β-桶状结构蛋白(β-Barrel Proteins)。这... 除了细胞质膜,革兰氏阴性细菌细胞还有一层组成细胞壁的外膜(Outer Membrane)。膜蛋白是外膜的主要组成成分之一,绝大多数外膜蛋白是由反向平行的β-折叠(β-Strands)通过相邻的氢键结合形成的β-桶状结构蛋白(β-Barrel Proteins)。这些蛋白既可作为通道蛋白、转运蛋白、酶、受体、毒力因子,也可作为结构蛋白发挥稳定外膜的重要作用,它们是否正确折叠并整合到外膜对革兰氏阴性细菌的生存至关重要。大多数外膜蛋白易于重组表达和体外重折叠(in vitro refolding),并且折叠状态可通过多种方法测定,因此β-桶状结构外膜蛋白被当着模式蛋白来研究各类生物和非生物因子对膜蛋白折叠的影响,是膜蛋白研究的一大热点。本文将从β-桶状结构外膜蛋白体外折叠的研究方法和影响折叠的因素角度对近年相关研究进展进行综合述评,最后总结了外膜蛋白体外折叠模式,并结合作者的相关研究结果和观点对该领域的研究前景进行了展望。 展开更多
关键词 β-桶状结构外膜蛋白 体外重折叠 折叠效率
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Observation of nuclei reassembled from demembranatedXenopus sperm nuclei and analysis of their laminacomponents
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作者 QUJIAN CHUANMAOZHANG 《Cell Research》 SCIE CAS CSCD 1994年第2期163-172,共10页
A cell-free preparation obtained from extracts of activated Xenopus laevis eggs induced chromatin decondensation and nuclear formation from demembranated Xenopus sperm nuclei. Electron microscopy revealed that the rea... A cell-free preparation obtained from extracts of activated Xenopus laevis eggs induced chromatin decondensation and nuclear formation from demembranated Xenopus sperm nuclei. Electron microscopy revealed that the reassembled nucleus had a double-layered nuclear membrane, nuclear pore complexes, and decondensed chromatin etc. Indirect immunofluorescence analysis demonstrated the presence of lamina in newly assembled nuclei. Western-blotting results showed that lamin LII was present in egg extracts and in lamina of the reassembled nuclei which were previously reported to contain only eggderived lamin LIII. 展开更多
关键词 Nuclear assembly in vitro Xenopus laevis LAMINA
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Establishment of antenna membrane states FEM on analogue method
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作者 姜文辉 曹喜滨 赵阳 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2008年第5期635-637,共3页
On the basis of choosing the basic element as the bar and choosing the basic mesh as the triangle as well as supposing the conditions of the element, the membrane states of an antenna reflector were researched by the ... On the basis of choosing the basic element as the bar and choosing the basic mesh as the triangle as well as supposing the conditions of the element, the membrane states of an antenna reflector were researched by the analogue method, because the membrane effect was not omitted during the ending deployment process of the radial rib antenna. The expressions of the bar element’s section area and density were obtained, while the expression of the stress state during the ending deployment process of antenna was attained. During the establishment process of the analogue method, the analysis method of the net shell structure was employed. Moreover, during the backward deduction of membrane stress, the continuation method was adopted. Because the expression of the membrane stress state can realize the analysis on the antenna membrane state, this research has great significance of theoretical direction to the normal operation of the space deployable antenna. 展开更多
关键词 radial rib antenna analogue method net shell structure continuation method membrane states
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Microcrystallin eStructure and Luminescence of ZnS Thin Films
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作者 WANGYu-jiang LIURui-tang 《Semiconductor Photonics and Technology》 CAS 2000年第1期20-22,共3页
The electroluminescence thin films doped with erbium, fabricated by thermal evaporation with two boats, are analyzed by X-ray diffraction (XRD). The relationship between electroluminescence brightness and microstructu... The electroluminescence thin films doped with erbium, fabricated by thermal evaporation with two boats, are analyzed by X-ray diffraction (XRD). The relationship between electroluminescence brightness and microstructure of the thin films is obtained. The results reveal that the large grain size in high index plane of deposited microcrystalline film has an effect on electroluminescence characteristics of the film devices. 展开更多
关键词 ELECTROLUMINESCENCE Thin film MICROSTRUCTURE
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壳聚糖对幽门螺杆菌外膜屏障功能的影响
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作者 谢勇 谢正兴 +5 位作者 周南进 周小江 龚燕锋 陈江 吕农华 王崇文 《中华微生物学和免疫学杂志》 CAS CSCD 北大核心 2004年第8期623-623,共1页
关键词 壳聚糖 幽门螺杆菌 外膜屏障功能 外膜结构
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RLKs orchestrate the signaling in plant male-female interaction 被引量:9
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作者 Hongju Li Wei-Cai Yang 《Science China(Life Sciences)》 SCIE CAS CSCD 2016年第9期867-877,共11页
Different from animals, sessile plants are equipped with a large receptor-like kinase(RLK) superfamily. RLKs are a family of single trans-membrane proteins with divergent N-terminal extracellular domains capped by a s... Different from animals, sessile plants are equipped with a large receptor-like kinase(RLK) superfamily. RLKs are a family of single trans-membrane proteins with divergent N-terminal extracellular domains capped by a signal peptide and C-terminal intracellular kinase. Researches in the last two decades have uncovered an increasing number of RLKs that regulate plant development, stress response and sexual reproduction, highlighting a dominant role of RLK signaling in cell-to-cell communications. Sexual reproduction in flowering plants is featured by interactions between the male gametophyte and the female tissues to facilitate sperm delivery and fertilization. Emerging evidences suggest that RLKs regulate almost every aspect of plant reproductive process, especially during pollination. Therefore, in this review we will focus mainly on the function and signaling of RLKs in plant male-female interaction and discuss the future prospects on these topics. 展开更多
关键词 RLK SIGNALING plant reproduction pollen tube female gametophyte male-female interaction pollen tube growth and guidance pollen tube reception
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Diverse roles of SERK family genes in plant growth, development and defense response. 被引量:7
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作者 Min Fan Minmin Wang Ming-Yi Bai 《Science China(Life Sciences)》 SCIE CAS CSCD 2016年第9期889-896,共8页
Plant receptor-like protein kinases(RLKs) are transmembrane proteins with an extracellular domain and an intracellular kinase domain, which enable plant perceiving diverse extracellular stimuli to trigger the intracel... Plant receptor-like protein kinases(RLKs) are transmembrane proteins with an extracellular domain and an intracellular kinase domain, which enable plant perceiving diverse extracellular stimuli to trigger the intracellular signal transduction. The somatic embryogenesis receptor kinases(SERKs) code the leucine-rich-repeat receptor-like kinase(LRR-RLK), and have been demonstrated to associate with multiple ligand-binding receptors to regulate plant growth, root development, male fertility, stomatal development and movement, and immune responses. Here, we focus on the progress made in recent years in understanding the versatile functions of Arabidopsis SERK proteins, and review SERK proteins as co-receptor to perceive different endogenous and environmental cues in different signaling pathway, and discuss how the kinase activity of SERKs is regulated by various modification. 展开更多
关键词 RLK SERK signal transduction
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High-temperature interface superconductivity in bilayer copper oxide films by pulsed laser deposition 被引量:1
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作者 Jia-hao Deng Tian-shuang Ren +4 位作者 Le-le Ju Hong-rui Zhang Ji-rong Sun Bao-gen Shen Yan-wu Xie 《Science China Materials》 SCIE EI CSCD 2020年第1期128-135,共8页
In a seminal work, Gozar et al. reported on the high-temperature interface superconductivity in bilayers of insulating La2Cu O4 and metallic La2-xSrxCuO4(x=0.45). An interesting question to address is how general and ... In a seminal work, Gozar et al. reported on the high-temperature interface superconductivity in bilayers of insulating La2Cu O4 and metallic La2-xSrxCuO4(x=0.45). An interesting question to address is how general and robust this interface superconductivity is. In the past, the cuprate bilayers were grown in a unique atomic-layer molecular beam epitaxy system, with a Sr doping range of x≤0.47, and the atomically flat interface was thought to be indispensable. Here, we have fabricated bilayers of La2CuO4 and La2-xSrxCuO4 by pulsed laser deposition. We have tried to extend the nominal doping range of Sr from the previous maximum of 0.47 to the present1.70(the nominal Sr content in the targets). X-ray diffraction result indicates that our La2-xSrxCuO4 films with x≤0.60 have very high crystalline quality;but the film crystalline structure degrades gradually with further increasing x, and finally the structure is fully lost when x reaches 1.40 and higher. Although the film quality scatters dramatically, our experiments show that there exists superconductivity for bilayers in nearly the entire over-doped Sr range, except for a non-superconducting region at x^0.80. These observations demonstrate that the interface superconductivity in copper oxides is very general and robust. 展开更多
关键词 CUPRATE SUPERCONDUCTIVITY interface pulsed laser deposition high temperature superconductivity
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