一起戊型肝炎暴发的血清流行病学调查

目的 了解一起戊型肝炎暴发的血清学特点。方法 对某单位在10 d内先后发病的5例急性黄疸性肝炎患者、在该单位食堂就餐的1 675人(暴发人群)及未就餐的邻近单位883人(对照人群)的血清在首发病例26 d后进行抗-HEV IgM和IgG检测,数据进行统计学分析。结果5例患者抗-HEV IgM和IgG均为阳性。暴发人群抗-HEV IgM和IgG的阳性率分别为8.7％和38.4％,而对照人群仅分别为0.1％和28.6％,差别均有非常显著意义。暴发人群145例抗-HEV IgM(+)中,ALT增高32例,明显高于IgM(-)及对照;而抗-HEV IgM(-)的ALT增高比例并不高于对照人群。4例患者系列血清检测见抗-HEV IgM逐渐下降,感染后4个月多数转阴,而IgG在感染后第2-3个月达高峰,随后缓慢下降。暴发人群中抗-HEV IgM(+)的IgG平均水平最高,IgM(-)而IgG(+)的IgC平均水平亦明显高于对照,提示暴发人群中既往感染者受到了免疫加强。暴发人群中抗-HEV IgM(+)者在性别及年龄组间差异无显著意义,但其中ALT增高男性的比例显著高于女性,而与年龄无关。结论 本次急性黄疸性肝炎的暴发由戊型肝炎病毒引起,与食源有关;抗-HEV IgM和IgG不仅可用于临床病例诊断,也可用于人群调查;感染危险性与年龄及性别无关,但男性ALT增高更常见

基于空间算子代数理论的被动步行机器人局部稳定性分析

为了方便实现机器人稳定控制，利用空间算子代数理论构建了该被动步行机器人稳定性分析中的庞加莱映射函数，推导了其摆动相态和碰撞相态的动力学方程。利用数值分析的方法求解映射函数的稳定不动点，分析了该被动模型的局部稳定性。结果表明，空间算子代数理论在被动步行机器人稳定性分析中能有效快速地建立庞加莱映射函数，避免了拉格朗日力学在建模过程中求解偏导数的复杂计算；同时，局部稳定性分析中得知，该被动步行机器人只有在“稳定”不动点的时候才具备周期稳定步态，否则，会出现周期分岔现象

Using electrochemistry-total internal reflection imaging ellipsometry to monitor biochemical oxygen demand with polyaniline modified electrode

Biochemical oxygen demand (BOD) is an important indicator for characterizing organic pollution in water. So various BOD sensors have been developed for BOD detection. BOD sensors based on a Clark electrode have the problem of signal drift. To overcome this problem, a combined electrochemical and total internal reflection imaging ellipsometry sensor has been proposed. To improve the sensitivity, polyaniline (PAn) and PAn incorporated with Fe(III) meso-tetra (4-sulfonatophenyl) porphyrin (FeTSPP) have been introduced on the working electrode. The results show that the combination system is effective for BOD detection with PAn. By incorporating FeTSPP, the optical and electrochemical responses of a PAn modified gold chip to BOD are improved significantly. Finally, the relationship between the optical and electrochemical signals is investigated by establishing a glass/Au/PAn-based film/liquid model. The analysis reveals that both signals represent the ratio change of the oxidized state of PAn in a similar way

Imaging ellipsometry biosensor: Basic theory, principles of operation, and applications

The imaging ellipsometry biosensor (IEB), first proposed in 1995, has advanced from a simple concept to a powerful biosensor with high throughput, high sensitivity, high specificity, and low sample consumption. By combining the technique with surface plasmon resonance, IEBs operating under total internal reflection conditions can perform real-time multisample detection of biomolecule interactions. In this paper, the authors discuss the basic theory, principles of operation, design requirements, sensing chip modifications, methodologies and performance, and applications of IEBs