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排序方式: 共有568条查询结果,搜索用时 34 毫秒
1.
Colleen Varaidzo Manyumwa
zlem Tastan Bishop 《International journal of molecular sciences》2021,22(6)
Carbonic anhydrases (CAs) have been identified as ideal catalysts for CO2 sequestration. Here, we report the sequence and structural analyses as well as the molecular dynamics (MD) simulations of four γ-CAs from thermophilic bacteria. Three of these, Persephonella marina, Persephonella hydrogeniphila, and Thermosulfidibacter takaii originate from hydrothermal vents and one, Thermus thermophilus HB8, from hot springs. Protein sequences were retrieved and aligned with previously characterized γ-CAs, revealing differences in the catalytic pocket residues. Further analysis of the structures following homology modeling revealed a hydrophobic patch in the catalytic pocket, presumed important for CO2 binding. Monitoring of proton shuttling residue His69 (P. marina γ-CA numbering) during MD simulations of P. hydrogeniphila and P. marina’s γ-CAs (γ-PhCA and γ-PmCA), showed a different behavior to that observed in the γ-CA of Escherichia coli, which periodically coordinates Zn2+. This work also involved the search for hotspot residues that contribute to interface stability. Some of these residues were further identified as key in protein communication via betweenness centrality metric of dynamic residue network analysis. T. takaii’s γ-CA showed marginally lower thermostability compared to the other three γ-CA proteins with an increase in conformations visited at high temperatures being observed. Hydrogen bond analysis revealed important interactions, some unique and others common in all γ-CAs, which contribute to interface formation and thermostability. The seemingly thermostable γ-CA from T. thermophilus strangely showed increased unsynchronized residue motions at 423 K. γ-PhCA and γ-PmCA were, however, preliminarily considered suitable as prospective thermostable CO2 sequestration agents. 相似文献
2.
V. A. Zheligovsky 《Journal of scientific computing》1993,8(1):41-68
The article discusses computational aspects of the kinematic problem of magnetic field generation by a Beltrami flow in a sphere. Galerkin's method is applied with a functional basis consisting of Laplace operator eigenfunctions. Dominant eigenvalues of the magnetic induction operator and associated magnetic eigenmodes are obtained numerically for a certain Beltrami flow for magnetic Reynolds numbers up to 100. The eigenvalue problem is solved by a highly optimized iterative procedure, which is quite general and can be applied to numerical treatment of arbitrary linear stability problems. 相似文献
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对交替行对角化(ARD)算法收敛性进行分析.基于收敛性分析,给出了一些关于如何选取初始矩阵的策略,提出了算法终止的新准则.通过3个数值例子来说明所提出的分析策略的有效性. 相似文献
5.
一种网络社团划分的评价及改进方法 总被引:1,自引:0,他引:1
主要从节点在所属群体内的相对重要程度出发, 尝试性地给出一种网络社团结构的新定义, 并在此基础上构建了一种网络社团划分的评价及改进方法。该方法既可以与现有的社团划分算法进行组合, 形成新的网络社团划分算法, 也可以独立使用, 对网络社团的划分结果进行评价与改进。最后, 通过MCL、GN、Factions等方法及算例对提出的算法进行了验证与分析。 相似文献
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PSN(pocket switched network)网络作为一种特殊的DTN(Delay Tolerance Network)网络,除了具有不包含持续端到端连接、高传输时延及节点资源受限的特点以外,具有更强的社会规律性.本文在研究了现有的算法的基础上,提出了一种基于社会信息的路由算法—BridgingCom.为使消息尽快从本地传递到目标节点,我们选择桥接中心度(Bridging Centrality)作为中继节点的选择依据.实验结果表明,与已有相关算法相比,本改进算法能够在网络负载较低的情况下获得较高的传输效率,较低的传输延迟. 相似文献
8.
Xiangmao MENG Wenkai LI Xiaoqing PENG Yaohang LI Min LI 《Frontiers of Computer Science》2021,15(6):156902
In the post-genomic era, proteomics has achieved significant theoretical and practical advances with the development of high-throughput technologies. Especially the rapid accumulation of protein-protein interactions (PPIs) provides a foundation for constructing protein interaction networks (PINs), which can furnish a new perspective for understanding cellular organizations, processes, and functions at network level. In this paper, we present a comprehensive survey on three main characteristics of PINs: centrality, modularity, and dynamics. 1) Different centrality measures, which are used to calculate the importance of proteins, are summarized based on the structural characteristics of PINs or on the basis of its integrated biological information; 2) Different modularity definitions and various clustering algorithms for predicting protein complexes or identifying functional modules are introduced; 3) The dynamics of proteins, PPIs and sub-networks are discussed, respectively. Finally, the main applications of PINs in the complex diseases are reviewed, and the challenges and future research directions are also discussed. 相似文献
9.
As a great challenge of network virtualization, virtual network embedding/mapping is increasingly important. It aims to successfully and efficiently assign the nodes and links of a virtual network (VN)... 相似文献
10.
张文丹 《长春理工大学学报(自然科学版)》2014,(3):147-150
为了克服具有N重特征值的状态矩阵发生亏损现象后对灵敏度分析的制约,本文基于亏损矩阵的若当标准形理论,引入广义特征向量及其伴随向量系,提出了广义特征向量灵敏度的全模态算法。求解亏损矩阵广义特征向量的灵敏度时,发现除一个灵敏度系数为非精确解外,其余灵敏度系数均为精确解。针对非精确解,通过引入松驰因子获得了较好的近似解。数值算例证实该算法适用于N重亏损状态矩阵的灵敏度分析。 相似文献