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261.
鼠肝癌淋巴道转移细胞模型的蛋白质组学研究   总被引:1,自引:1,他引:1  
对2株来源于同一亲本细胞但淋巴道转移力显著不同的小鼠肝癌腹水型细胞株Hca-F(淋巴结转移率75%)和Hca-P(淋巴结转移率25%), 采用荧光差异双向凝胶电泳(2D DIGE)和DeCyder定量分析软件及HPLC-nESI-MS/MS技术, 定量分析和鉴定了小鼠肝癌细胞Hca-F和Hca-P的差异表达蛋白. 结果显示, 有116个蛋白质点表达水平存在明显差异(p<0.05), 在Hca-F中表达上调蛋白质点62个, 下调蛋白质点54个. 对所有116个蛋白质点进行了电喷雾串联质谱鉴定, 共鉴定出109种单一(Unique)蛋白. 其中部分蛋白已被报道与不同类型肿瘤的发生、浸润和转移相关, 多数蛋白质被首次报道与肝癌的淋巴道转移过程直接相关.  相似文献   
262.
In recent years, the identification of the essential nodes in complex networks has attracted significant attention because of their theoretical and practical significance in many applications, such as preventing and controlling epidemic diseases and discovering essential proteins. Several importance measures have been proposed from diverse perspectives to identify crucial nodes more accurately. In this paper, we propose a novel importance metric called node propagation entropy, which uses a combination of the clustering coefficients of nodes and the influence of the first- and second-order neighbor numbers on node importance to identify essential nodes from an entropy perspective while considering the local and global information of the network. Furthermore, the susceptible–infected–removed and susceptible–infected–removed–susceptible epidemic models along with the Kendall coefficient are used to reveal the relevant correlations among the various importance measures. The results of experiments conducted on several real networks from different domains show that the proposed metric is more accurate and stable in identifying significant nodes than many existing techniques, including degree centrality, betweenness centrality, closeness centrality, eigenvector centrality, and H-index.  相似文献   
263.
Recently, amorphous materials have gained great attention as an emerging kind of functional material, and their characteristics such as isotropy, absence of grain boundaries, and abundant defects are very likely to outrun the disadvantages of crystalline counterparts, such as low conductivity, and ultimately lead to improved charge transfer efficiency. Herein, we investigated the effect of amorphization on the charge transfer process and photocatalytic performance with a phosphonate-based metal–organic framework (FePPA) as the research object. Comprehensive experimental results suggest that compared to crystalline FePPA, amorphous FePPA has more distorted metal nodes, which affects the electron distribution and consequently improves the photogenerated charge separation efficiency. Meanwhile, the distorted metal nodes in amorphous FePPA also greatly promote the adsorption and activation of O2. Hence, amorphous FePPA exhibits a better performance of photocatalytic C(sp3)−H bond activation for selective oxidation of toluene to benzaldehyde. This work illustrates the advantages of amorphous MOFs in the charge transfer process, which is conducive to the further development of high performance MOFs-based photocatalysts.  相似文献   
264.
To create both greener and high-power metal-ion batteries, it is of prime importance to invent an unprecedented electrode material that will be able to store a colossal amount of charge carriers by a redox mechanism. Employing periodic DFT calculations, we modeled a new metal-organic framework, which displays energy density exceeding that of conventional inorganic and organic electrodes, such as Li- and Na-rich oxides and anthraquinones. The designed MOF has a rhombohedral unit cell in which an Ni(II) node is coordinated by 2,5-dicyano-p-benzoquinone linkers in such a way that all components participate in the redox reaction upon lithiation, sodiation and magnesiation. The spatial and electronic changes occurring in the MOF after the interaction with Li, Na and Mg are discussed on the basis of calculated electrode potentials versus Li0/Li+, Na0/Na+ and Mg0/Mg2+, respectively. In addition, the specific capacities and energy densities are calculated and used as a measure for the electrode applicability of the designed material. Although the highest capacity and energy density are predicted for Li storage, the greater structural robustness toward Na and Mg uptake suggests a higher cycling stability in addition to lower cost. The theoretical results indicate that the MOF is a promising choice for a green electrode material (with <10% heavy metal content) and is well worth experimental testing.  相似文献   
265.
具有星形结点的平面五次系统的全局结构分析   总被引:1,自引:1,他引:1       下载免费PDF全文
该文对具有星形结点的平面五次系统的全局结构的拓扑分类应用Ⅰ Ⅳ型区域(见[2]),讨 论了平面五次系统(1)的全局结构的拓扑分类,并得到93种全局结构及其右边多项式系统的判定方法。   相似文献   
266.
刘凯  吴寒  张纯  李凡 《力学季刊》2016,37(3):502-512
针对正交各向异性织物,本文提出了一种含附加节点的三角形弹簧质点模型.通过冗余自由度的引入和缩聚,能够实现有限元模型和弹簧质点模型三角形单元刚度矩阵的精确相等;据此,针对一般正交各向异性材料常数和单元形状,推导出弹簧质点模型中弹簧刚度系数及附加节点位置的解析表达式,有效解决了传统弹簧质点模型在正交各向异性织物仿真中存在的计算精度不高、弹簧参数选取随意等缺陷;并进一步完善了基于弹簧质点模型的柔性织物空间变形算法.数值模拟表明本文提出的弹簧质点模型和变形算法在进行织物仿真计算时,具有精度好、通用性强等优点.  相似文献   
267.
We show that the problem of packing edges and triangles in a graph in order to cover the maximum number of nodes can be solved in polynomial time. More generally we present results for the problem of packing edges and a family of hypomatchable subgraphs.  相似文献   
268.
本文讨论了R~2上的弧线型结点组之一:双曲线型结点组上插值的适定性问题。  相似文献   
269.
采用衰减全反射(ATR)探头和傅里叶变换红外光谱(FTIR)仪测定了新鲜离体的甲状腺癌微转移颈部淋巴结(16枚)和非转移性淋巴结(16枚)的FTIR光谱, 配对比较了两组光谱13个谱带的峰位、相对峰强及半高宽等38个FTIR参数, 明确了甲状腺癌微转移淋巴结的光谱特征.结果表明, 与非转移性淋巴结相比, 微转移淋巴结光谱中与蛋白、脂质、糖类和核酸相关的谱带均发生了明显变化:与蛋白质相关的谱带的相对峰强I3280/I1460和I1640/I1460显著升高, 半高宽F1640显著增宽, 而F1546则变窄; 与脂类相关的相对峰强I1400/I1460明显增高; 与糖类相关的1165 cm-1处谱带的相对峰强I1165/I1460显著降低; 与核酸相关的1240 cm-1处谱带的相对峰强I1240/I1460显著升高.结果表明, FTIR能够检测出甲状腺癌的微转移淋巴结, 可能应用于甲状腺癌病人的精准手术治疗.  相似文献   
270.
泡泡布点方法能够在复杂区域内生成高质量的节点集,但是其计算效率仍有待提高,为此本文做了两方面的改进。一是种子填充算法思想应用于节点的初始布置中,从而生成数目合适的节点集,省去了原布点方法中的节点增删过程,有效地节约模拟时间;二是简化了泡泡运动模拟的控制方程,使得运动模拟更加简单。数值算例表明,改进的泡泡布点方法生成的网格平均质量均高于0.94,且计算效率相比原布点方法提高90%以上。因此,改进的泡泡布点方法是一种高质量、高效率且适宜求解大规模问题的节点布置方法。  相似文献   
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