移动图书馆情景感知信息推荐服务用户接受行为研究

[目的/意义]基于多理论假设,为移动图书馆平台提供基于情景感知的信息推荐服务提供理论和实证依据,以丰富移动图书馆个性化服务的内容。[方法/过程]结合技术接受行为理论、创新扩散理论和感知风险理论,构建基于情景感知的信息推荐服务用户接受行为影响因素模型,并运用逻辑回归方法进行实证研究。[结果/结论]情景感知信息推荐服务作为移动图书馆信息服务的新方式,有着个性化的显著优势。同时,技术和设备的兼容为移动图书馆情景感知信息推荐服务提供了外部动力和重要保障。     

承德市森林植被净初级生产力的遥感估算

以承德市的森林分布区为研究区域,基于改进的光能利用率模型,利用2008年MODIS/NDVI产品和地面气象站点数据,结合土地覆被类型,估算承德市森林植被的年净初级生产力,并分析其时空分布格局.研究结果表明:2008年承德市森林NPP的总量为1.075×108 g.a-1,年平均值为424.59 g.m-2.a-1,NPP最高值为656.78 g.m-2.a-1.总体空间分布趋势是东南高,西北低,其季节变化较明显,呈单峰型.     

中埃电气领域职业标准比较研究

以两国职业标准内容为指导,列举分析了中国维修电工高级职业标准和埃塞工业电子及控制技术五级标准的异同,旨在为两国职业标准的执行者和相关领域教师提供一定的借鉴。     

旅行社业务运作流程再造研究

旅行社普遍存在着业务流程运作相对混乱、运作效率不高、业务流程操作成本较高等问题,需要对当前阶段旅行社业务流程运作状况进行研究,结果表明：企业组织结构、人力资本缺乏、旅行社发展阶段性特征以及旅行社信息化发展水平是影响旅行社流程效率提高的主要因素。     

破解城市建设融资难题的思考

随着城市化进程的加快,城市建设融资面临着重重困难。针对当前融资现状中的矛盾,应该要增强城市经营理念,进一步深化和开拓投融资渠道：要丰富拓宽融资渠道,创新金融产品,凋动社会资本积极性;蛰完善基础设施价格体系;要完善城市投融资相关的法律、政策和机制等,来破解当前城市建发面临着诸多的融资难题。     

阿尔茨海默病发病机理的研究进展

阿尔茨海默病(Alzheimer’s disease,AD)病因及发病机制尚未完全阐明,有关其发病机制有β-淀粉样蛋白假说、Tau 蛋白假说、炎症学说和氧化应激学说等多种.本文就现有较公认的发病机制研究进展作一综述.     

Ds-echinoside A, a new triterpene glycoside derived from sea cucumber, exhibits antimetastatic activity via the inhibition of NF-κB-dependent MMP-9 and VEGF expressions

Ds-echinoside A (DSEA), a non-sulfated triterpene glycoside, was isolated from the sea cucumber Pearsonothuria graeffei. In vitro and in vivo investigations were conducted on the effects of DSEA on tumor cell adhesion, migration, invasion, and angiogenesis. In this study, we found that DSEA inhibited the proliferation of human hepatocellular liver carcinoma cells Hep G2, with a half-maximal inhibitory concentration (IC₅₀) of 2.65 μmol/L, and suppressed Hep G2 cell adhesion, migration, and invasion in a dose-dependent manner. DSEA also reduced tube formation of human endothelial cells ECV-304 on matrigel in vitro and attenuated neovascularization in the chick embryo chorioallantoic membrane (CAM) assay in vivo. Immunocytochemical analysis revealed that DSEA significantly decreased the expression of matrix metalloproteinase-9 (MMP-9), which plays an important role in the degradation of basement membrane in tumor metastasis and angiogenesis. DSEA also increased the protein expression level of tissue inhibitor of metalloproteinase-1 (TIMP-1), an important regulator of MMP-9 activation. From the results of Western blotting, the expressions of nuclear factor-kappa B (NF-κB) and vascular endothelial growth factor (VEGF) were found to be remarkably reduced by DSEA. These findings suggest that DSEA exhibits a significant antimetastatic activity through the specific inhibition of NF-κB-dependent MMP-9 and VEGF expressions.     

An efficient method of addressing ectopic beats: new insight into data preprocessing of heart rate variability analysis

Heart rate variability (HRV) analysis is affected by ectopic beats. An efficient method was proposed to deal with the ectopic beats. The method was based on trend correlation of the heart timing signal. Predictor of R-R interval (RRI) value at ectopic beat time was constructed by the weight calculation and the slope estimation of preceding normal RRI. The type of ectopic beat was detected and replaced by the predictor of RRI. The performance of the simulated signal after ectopic correction was tested by the standard value using power spectrum density (PSD) estimation, whereas the results of clinical data with ectopic beats were compared with the adjacent ectopic-free data. The result showed the frequency indexes after ectopy corrected had less error than other methods with the test of simulated signal and clinical data. It indicated our method could improve the PSD estimation in HRV analysis. The method had advantages of high accuracy and real time properties to recover the sinus node modulation.     

RRM1 gene expression in peripheral blood is predictive of shorter survival in Chinese patients with advanced non-small-cell lung cancer treated by gemcitabine and platinum

Objective  

To evaluate the predictive values of gene expressions of ribonucleotide reductase M1 (RRM1) and breast cancer susceptibility gene 1 (BRCA1) in peripheral blood from Chinese patients with non-small-cell lung cancer (NSCLC) treated with gemcitabine plus platinum.