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61.
Curcumin exhibits both immunomodulatory properties and anticarcinogenic effects which have been investigated in different experimental tumor models and cancer types. Its interactions with multiple signaling pathways have been documented through proteomic studies on malignant cells in culture; however, in vivo approaches are scarce. In this study, we used a rat model of highly invasive peritoneal mesothelioma to analyze the residual tumor proteomes of curcumin-treated rats in comparison with untreated tumor-bearing rats (G1) and provide insights into the modifications in the tumor microenvironment/malignant cell crosstalk. The cross-comparing analyses of the histological sections of residual tumors from two groups of rats given curcumin twice on days 21 and 26 after the tumor challenge (G2) or four times on days 7, 9, 11 and 14 (G3), in comparison with G1, identified a common increase in caveolin-1 which linked with significant abundance changes affecting 115 other proteins. The comparison of G3 vs. G2 revealed additional features for 65 main proteins, including an increase in histidine-rich glycoprotein and highly significant abundance changes for 22 other proteins regulating the tumor microenvironment, linked with the presence of numerous activated T cells. These results highlight new features in the multiple actions of curcumin on tumor microenvironment components and cancer cell invasiveness.  相似文献   
62.
In the paper the aim and meaning of traffic microscopic simulation is discussed first, and then three sub-models of the system are established, e. i. the model for random generation of the vehicles, the model for car-following and lane change influenced by an adjacent vehicle, and the model for control and optimization of intersection with signal. Optimization of the traffic signal timing with a genetic algorithm and a microscopic simulation is carried out. It represents a novel approach to solving optimal signal timing.  相似文献   
63.
The discovery of new antibiotic adjuvants is an attractive option for overcoming antimicrobial resistance. We have previously reported the discovery of a bis-6-bromoindolglyoxylamide derivative of spermine as being able to enhance the action of antibiotics against Gram-negative bacteria but suffers from being cytotoxic and red-blood cell haemolytic. A series of analogues was prepared exploring variation of the indolglyoxylamide unit, to include indole-3-acrylic, indole-3-acetic and indole-3-carboxylate units, and evaluated for antibiotic enhancing properties against a range of Gram-negative bacteria, and for intrinsic antimicrobial, cytotoxic and haemolytic properties. Two spermine derivatives, bearing 5-bromo-indole-3-acetic acid ( 17 ) and 5-methoxy-indole-3-acrylic acid ( 14 ) end groups were found to exhibit good to moderate antibiotic adjuvant activities for doxycycline towards the Gram-negative bacteria Pseudomonas aeruginosa, Escherichia coli and Klebsiella pneumoniae, but with more modest intrinsic antimicrobial activity and greatly reduced cytotoxic and haemolytic properties. The mechanism of action of the latter derivative identified its ability to disrupt the outer membranes of bacteria and to inhibit the AcrAB-TolC efflux pump directly or by inhibiting the proton gradient.  相似文献   
64.
65.
Using a 34 years database consisting of sea level pressure and sea ice concentration, the relationship between Antarctic Oscillation (AAO) and Antarctic Sea-ice Oscillation (ASO) was investigated. Firstly, Empirical Orthogonal Function (EOF) analysis depicts the spatial variability of AAO and ASO and Antarctic Sea-ice Oscillation Index (ASOI) was defined for the first time. Secondly, power spectrum and headlag correlation analysis show that ASO and AAO have the same periods of quasi-three years, quasi-one year and quasihalf a year. Corresponding to AAO, ASO has an evident antioscillation after one and half a year.  相似文献   
66.
Large-scale hydropower development disrupts local livelihoods and resource access. Adverse impacts are often greater for women than men, but also large for children, the elderly, poorer households and ethnic minorities. Burdens of resettlement often fall disproportionately on already disadvantaged individuals. The purpose of this study was to evaluate how international, national and local civil society organizations (CSOs) have addressed gender in hydropower development in the Mekong Region. Four CSO orientations are distinguished: communitarian, environmentalist, knowledge-based and feminist. Common activities of CSOs were to share information, to expand participation and to mobilize development. The extent to which these activities were promoted and appear to be making space for women depended on the types of CSOs and women and men targeted or otherwise involved.  相似文献   
67.
Nanofiltration separation has become a popular technique for removing large organic molecules and inorganic substances from water. It is achieved by a combination of three mechanisms: electrostatic repulsion, sieving and diffusion. In the present work, a modei based on irreversible thermodynamics is extended and used to estimate rejection of inorganic salts and organic substances. Binary systems are modeled, where the feed contains an ion that is much less permeable to the membrane as compared with the other ion. The two modei parameters are estimated by fitting the modei to the experimental data. Variation of these parameters with the composition of the feed is described by an empirical correlation. This work attempts to describe transport through the nanofiltration membranes by a simple model.  相似文献   
68.
自主水下航行器 (Autonomous underwater vehicle, AUV) 的协同导航是解决水下导航定位问题的重要方法, 其中导航系统的定位误差增长特性是衡量其定位性能的关键指标. 本文针对单领航者相对位置测量的多 AUV 协同导航系统, 利用扩展卡尔曼滤波方法建立了导航系统的整体定位误差关于相对位置量测误差的传递方程. 在此基础上, 通过求解系统定位误差随时间演化的代数黎卡提方程, 得到了其在稳态情形下的方差上界估计. 理论分析表明, 单领航 AUV 协同导航系统的整体定位误差有界收敛且与初始化滤波方差无关, 具有良好的综合性能. 最后, 仿真实例验证了文中理论分析结果的正确性.  相似文献   
69.
Recursive partitioning methods are among the most popular techniques in machine learning. The purpose of this paper is to investigate how to adapt this methodology to the bipartite ranking problem. Following in the footsteps of the TreeRank approach developed in Clémençon and Vayatis (Proceedings of the 2008 Conference on Algorithmic Learning Theory, 2008 and IEEE Trans. Inf. Theory 55(9):4316–4336, 2009), we present tree-structured algorithms designed for learning to rank instances based on classification data. The main contributions of the present work are the following: the practical implementation of the TreeRank algorithm, well-founded solutions to the crucial issues related to the splitting rule and the choice of the “right” size for the ranking tree. From the angle embraced in this paper, splitting is viewed as a cost-sensitive classification task with data-dependent cost. Hence, up to straightforward modifications, any classification algorithm may serve as a splitting rule. Also, we propose to implement a cost-complexity pruning method after the growing stage in order to produce a “right-sized” ranking sub-tree with large AUC. In particular, performance bounds are established for pruning schemes inspired by recent work on nonparametric model selection. Eventually, we propose indicators for variable importance and variable dependence, plus various simulation studies illustrating the potential of our method.  相似文献   
70.
检波器组内高差对高频信息压制的理论分析   总被引:1,自引:0,他引:1  
 在地震勘探野外采集中,目前普遍采用地表低速带的速度〖WTBX〗V0〖WTBZ〗乘以目的层反射波主频的1/4视周期来计算检波器组内高差允许值,即使在沙漠及山地的地震资料采集中也是如此。本文通过理论计算与模型试验证明:在主频不是很高而次生干扰波非常发育的一些工区,采用降速带的速度〖WTBX〗V1〖WTBZ〗乘以最浅目的层反射波主频的1/2视周期计算组内高差,就可以得到信噪比较高的用于构造解释的低频剖面;相反,如果在这类地区拘泥于原先关于组内高差的规定,就会因为强烈的次生干扰波没有得到有效压制而导致地震剖面的信噪比大大降低,进而使得企图通过减小组内高差、保护高频信息、提高分辨率的初衷也无法实现。  相似文献   
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