The grid-cell-culture technique: the direct examination of virus-infected cells and progeny viruses

We describe a method for the structural analysis and identification of viruses, without purification or concentration steps which could alter virus morphology. Virus-infected cells grown on carbon-Parlodion-coated electron microscope grids release large numbers of progeny viruses which adsorb to the surface of the grid and are revealed by negative staining. The technique is rapid, sensitive and can be used at three levels. (1) Negative staining of whole cell preparations revealed both extracellular and intracellular viruses or nucleocapsids beneath the plasma membrane; (2) non-ionic detergent extraction of cells infected with certain viruses reveals cytoskeleton-associated, virus-specific structures normally only observed after thin sectioning; (3) cultures prepared by either procedure are suitable for colloidal gold immunological studies. Extracellular and cytoskeletal-associated viruses were heavily and specifically labelled with gold. The results indicate that the technique may be used to rapidly identify unknown viruses on the basis of size, topography, morphology and mode of maturation from the infected cell, as well as the presence of characteristic intracellular cytoskeletal-associated structures. The technique also has potential use in the sero-grouping and sero-typing of viruses with specific monoclonal antibodies.     

如何建立一个全封闭的信息管理系统

本文论述了建立全封闭系统对防范电脑病毒、保护保密数据、实现专机专用的作用,提出了从软件、硬件方面建立全封闭系统的方法,并给出了软件实现技巧和主控程序实例.     

新冠肺炎疫情背景下聚集性传染风险智能监测模型

新型冠状病毒肺炎疫情严重威胁人们的生命安全,对于聚集性人群密度及口罩佩戴情况的监管是控制病毒扩散的重要途经。公共场所具有人流密集且流动性大的特点,人工监测易增加感染风险,而现有基于深度学习的口罩检测算法存在功能及场景单一的问题,不能在多场景下实现多类别检测,同时精度也有待提升。提出Cascade-Attention R-CNN目标检测算法,实现对聚集区域、行人和口罩佩戴情况的自动检测。针对任务中目标尺度变化过大的问题,选取高精度两阶段Cascade R-CNN目标检测算法作为基础检测框架。通过设计多个级联的候选分类-回归网络并加入空间注意力机制,突出候选区域特征中的重要特征并抑制噪声特征,从而提高检测精度。在此基础上,构建聚集性传染风险智能监测模型,结合Cascade-Attention R-CNN算法的输出结果确定传染风险等级。实验结果表明,该模型对于不同场景和视角的多类别目标图片具有较高的准确性和鲁棒性,Cascade-Attention R-CNN算法平均精度均值达到89.4%,较原始Cascade RCNN算法提升2.6个百分点,较经典的两阶段目标检测算法Faster R-CNN和单阶段目标检测框架RetinaNet分别提升10.1和8.4个百分点。     

E.coli表达HEV ORF2编码蛋白第112～607氨基酸片段的免疫原性及其诱生抗体的病毒中和活性

目的 探讨E.coli表达的戊型肝炎病毒(HEV)ORF2编码蛋白第112～607氨基酸片段(pORF2-56K)的免疫原性及其诱生抗体的病毒中和活性。方法 pORF2-56K免疫小鼠和豚鼠,用ELISA检测血清抗体效价。将HEV毒种与高效价豚鼠灭活血清在体外孵育后,接种于2BS细胞,用RT-PCR检测病毒RNA的复制情况。结果E.coli表达的pORF2-56K可诱导机体产生高水平的HEV特异性抗体和强烈的免疫记忆。该抗体可在体外有效中和HEV,使之失去在2BS细胞中有效复制的能力。结论 E-coli表达的pORF2-56K具有良好的免疫原性,且其诱生抗体具有中和HEV的能力,可作为HEV重组疫苗的候选抗原。     

计算机局域网ARP病毒攻击机理及防护方法

ARP病毒是一种特殊病毒,它利用了网络缺陷实施对网络的攻击,一般的杀毒软件和防火墙很难起到防护作用。防止ARP病毒攻击,应以预防为主,迅速查杀为辅。IP/MAC地址静态绑定、软件硬件结合防护是预防ARP病毒攻击的主要手段;一旦发生ARP病毒攻击,通过查找在网络中重复出现的MAC地址,可迅速发现攻击源,及时用专杀工具进行查杀可达到迅速处理ARP病毒攻击的目的。     

Ozone Disinfection Of Urban Storm Drain Water

Concerns regarding bacteria in runoff entering Santa Monica Bay were validated by the isolation of human enteric virus in storm drain effluents. As an alternative to chlorination, ozonation was investigated for disinfection of dry-weather urban runoff. Ozone at 10-20 mg/L reduced coliform counts an average of 3.4-logs, with 6-log maximal disinfection. Although varying contaminant concentrations complicate the analyses, total organic carbon predicted ozone demand, and effluent coliform counts were correlated with ozone residuals.     

纤维蛋白原制剂灭活病毒工艺的初步研究

在纤维蛋白原(简称纤原)常规生产工艺中增加“有机溶剂/表面活性剂(S/D)”灭活病毒步骤·TNBP及Tween-80浓度分别为0.3％及1％,在24℃处理6小时,能有效灭活标志病毒VSV(7.31g_(10))及Sindbis V(6.831g_(10))。残余的TNBP及Tween-80可通过两次8％乙醇沉淀去除。病毒灭活后纤原的可凝固蛋白纯度由原来的70.9±8.5％提高至85.5±6.0％,回收率可保持在64.7±3.8％。PAGE电泳显示来出现新的蛋白区带。     

反病毒引擎可扩展框架的研究与实现*

针对当前反病毒软件中引擎对特征码数据库过分依赖和各功能模块间耦合度大的问题。提出了一个可扩展的引擎框架,利用智能特征码和分解复合检测活动的方法实现了功能与数据的解耦合,应用控制反转的思想将功能模块之间控制耦合转换为接口耦合。该引擎框架不仅解决当前反病毒引擎缺乏可扩展性的问题,而且能方便地应用到嵌入式安全设备的设计中。原型系统验证了设计方案和核心算法的有效性,实验结果表明具有较好的检测性能。     

基于VB的Excel宏表病毒专杀工具设计与实现

基于VB的Excel宏表病毒专杀工具,具有清除硬盘、移动磁盘及用户指定目录中已知的Bookl宏表病毒及其他未知的Excel宏表病毒功能。本文分析宏表病毒的感染症状与原理,论述了程序的设计与实现。     

Particle-surface interaction in thin vitrified films for cryo-electron microscopy

The concentration of particles in thin vitrified films of suspensions is described as a function of various parameters such as the type of particles observed, the time the sample is left on the grid and the effect of different washing procedures. The thin films are prepared for cryo-electron microscopy by the classical, single-side blotting method or by blotting both sides of the grid simultaneously. The two-side blotting method gives the most faithful representation of the bulk solution. The single-side blotting method results in particles preferentially adsorbing to the non-blotted surface. This has the advantage that the concentration of particles in the thin vitrified film is higher than in the original suspension. The energy involved in adhesion of particles to the surface seems to be generally small. In most cases, it does not cause significant deformation of the particles or of the surface of the film. However, there are cases, as for example with lipid vesicles, where the particles are broken as a result of adsorption. Since particles remain adsorbed to the air-liquid interface, it is possible to wash or dialyse the solution directly on the grid with negligible loss of particles. This represents a very rapid and handy method for micro-dialysis. A thin film is then formed by blotting the specimen and vitrified by rapid cooling.