网络病毒的危害与防护

通过对计算机网络病毒危害性的描述,提出了计算机网络病毒的防治方法和技术。     

计算机网络病毒防治策略探析

计算机网络技术的发展为人们的工作生活带来了极大的便利,然而,计算机网络病毒也随之而产生,病毒对计算机网络的攻击性非常强,带来了网络数据的损坏,威胁着计算机网络的安全。在网络环境之下,病毒的传播范围更广,危害更大,为了保证计算机网络系统的安全,必须找出可行的措施来防止计算机网络病毒。本文就通过讨论计算机网络病毒防治的原则、管理策略、技术策略,为计算机网络病毒的防治提供一定的理论依据,从而帮助网络安全管理者加强安全管理工作,为计算机网络技术的发展提供一个安全可靠的环境。     

网络病毒的发展趋势及防治策略初探

随着计算机的飞速发展，电脑病毒借助网络的桥梁也随之越演越烈，它直接危害着计算机的数据安全。本文从黑客的构毒思维、网络病毒的发展趋势及防治对策入手，阐述如何防范病毒和保护数据。     

浅淡计算机网络病毒的危害与防治

如今,计算机病毒已进入网络时代,通常称之为网络病毒,这使得病毒的危害越来越大,治理越来越难,病毒的防治与反病毒技术面临着严峻的挑战。本文主要讲述了病毒的概述特征及分析了病毒的传统与新型危害,以及通过新的病毒检测技术与防治技术手段,对其进行有效防治。     

网络病毒防治技术在计算机管理中的应用

本文首先对计算机网络病毒进行了概述,包括网络病毒的类型、传播方式以及相关特点等内容,然后分析了危害计算机网络安全的风险因素,最后有针对性的提出了防治措施,以期加强网络病毒治理效果,避免黑客入侵等恶性事件的发生。     

基于WEB平台上安全协议的应用与分析

计算机的安全性历来都是人们讨论的主要话题之一。而计算机安全主要研究的是计算机病毒的防治和系统的安全。在计算机网络日益扩展和普及的今天，计算机安全的要求更高，涉及面更广。不但要求防治病毒，还要提高系统抵抗外来非法黑客入侵的能力，还要提高对远程数据传输的保密性，避免在传输途中遭受非法窃取。必须加上SSI安全技术加以保护。     

企业网络防病毒的五个误区

网络的发展给企业带来了广泛的应用，同时网络的发展也给企业网络带来了各种不安全的因素。黑客的攻击、计算机病毒的泛滥都严重影响着企业网络的正常应用和信息的安全，特别是近年计算机病毒的发展非常迅速，病毒的传播也从简单的介质传播方式向多样化的网络传播发展。当前人们对网络病毒的危害和防范方面存在着认识上的误区，本文将罗列以下误区供大家参考。     

浅谈Linux操作系统安全防范策略

随着网络的不断发展,网络安全是我们应该时刻注意的问题。Linux操作系统中维护信息安全的方法很多。本文主要从系统启动和登陆的安全性、限制网络访问、Linux病毒的防治、防止攻击和安装补丁方面探讨Linux操作系统安全防范的策略。     

乌鸡病毒性肝炎的防治

在夏季饲养的乌鸡，容易发生病毒性肝炎，应当采取合适的方法加以防治。乌鸡病毒性肝炎(DHV)是由乌鸡肝炎病毒引起的小乌鸡的一种急性接触性传染病，对于这类疾病要采取的预防措施有注射免疫疫苗，首先是在健康乌鸡群还没有发生病毒性肝炎之前预防接种。其次是在发生病毒性肝炎时而紧急接种。对病毒性肝炎治疗前我们要明确诊断，对于不同类型的乌鸡病毒性肝炎应该采取不同的治疗措施。乌鸡病毒性肝炎具有发病急、传播速度快和死亡率极高的特点。特别是三周龄内的小乌鸡发病，发病率能达到100%，7日龄内的小乌鸡死亡率高达85%~90%以上，7日龄到21日龄的死亡率是50%左右，经济损失较大，为了摸清乌鸡病毒性肝炎的防治办法，在查阅相关资料的基础上，结合我自身多年的实践经验，与大家共同探讨：     

浅谈江苏空管网络信息安全

近十几年来,计算机网络技术迅猛发展,在社会各个领域得到了广泛的推广和普及,并逐渐成为国家和企业发展的重要力量,但是,网络环境自身复杂和多变等特点,使得计算机网络面临黑客以及病毒的威胁。空管信息网络作为我国网络信息安全的重要组成部分,其中的信息资料是民航事业发展的命脉,如何保证空管信息网络安全成为越来越多的空管人所关注的重点。本文以江苏空管气象设备的系统网络构成为例,简要分析了空管系统网络存在的安全危险以及防治措施。     

计算机网络安全性分析

对计算机网络病毒及其特点 ,黑客及黑客程序对网络安全的威胁进行了分析 ,阐述了计算机网络的安全性问题并提出了提高网络安全性的基本策略 .     

公司局域网访问控制体系安全策略

公司局域网在运行过程中将会面临各种安全威胁,通过对公司局域网访问控制体系的安全问题进行分析,就存取控制技术、防火墙技术、病毒防治技术、数据加密和文件备份、文件和服务的共享访问和封锁系统安全漏洞几个方面提出基于访问控制的安全策略.     

Mosquitoes,birth rates and regional spillovers: Evidence from the Zika epidemic in Brazil

This paper investigates the impact of the incidence of the Zika virus on birth rates in Brazil. We estimated a difference-in-differences model that explicitly considers the spatial interaction of virus incidence, measuring its impact on the affected municipalities and their neighbours—not directly affected. Our results show that directly affected municipalities experienced a 1.7% decrease in birth rates in 2016 and 2.5% in 2017, while municipalities close to those affected—but not directly affected—showed reductions of 1.2% and 2.1% for the same periods. Moreover, the evidence shows that the effect was not guided by biological effects and was concentrated among younger women.     

Concentration of rotavirus by ultrafiltration

A hollow fibre ultrafiltration unit was evaluated for its capacity to concentrate human rotavirus from experimentally contaminated groundwater. The results of these experiments suggest that virus recovery is greatly improved by utilizing either a protein wash with beef extract or by backflushing the hollow fibres with phosphate buffered saline. An enzyme-linked immunosorbent assay (ELISA) was used to determine rotavirus recoveries after concentration.     

城镇污水系统中病毒特性和规律相关研究分析

根据新型冠状病毒的生物学特征,研究了病毒在水体中的赋存状态,分析总结了国内外污水处理中病毒的相关研究,认为污水处理厂只要保持正常稳定运行,就能够有效降低污水中病毒的浓度,可阻断肠道病毒和呼吸道病毒通过污水处理厂出水进行传播。对比分析了污水处理消毒过程中的臭氧消毒、氯消毒、紫外线消毒工艺,现有研究表明再生水处理过程的多级屏障作用可以有效去除病毒,结合工艺控制可以保障出水安全。此外,指出了污水处理工艺中可能产生气溶胶风险的位置,给出了相应的防护建议。这对新冠肺炎期间指导城镇污水处理厂安全稳定运行,防止新型冠状病毒进一步传播扩散有着重要参考意义。     

Chlorine dioxide reactivity with proteins

Studies were conducted to evaluate chlorine dioxide reactivity with proteins and the role of these reactions in the inactivation of the bacterial virus f2 with chlorine dioxide. The effect of chlorine dioxide on the ability of f2 to specifically attach to its host Escherichia coli K13 was compared to the inactivation of virus during the initial seconds of contact time. At pH 7.2 and and 5°C, the virus was rapidly inactivated with 0.6 mg l⁻¹ of chlorine dioxide. Approximately 2 log units of inactivation were observed within 30 s. The loss of protein specific attachment function nearly paralleled intact virus inactivation with 1.2 log units of attachment inhibition occurring within 30 s. The inactivation of virus and the inhibition of specific attachment both increased with increasing pH and increasing disinfectant concentration.Inactivation of f2 was hypothesized to occur as the result of chlorine dioxide reacting with discrete chemical moieties in the viral protein. Cysteine, tyrosine and tryptophan reacted with chlorine dioxide within a time frame that could affect viral inactivation. In denatured f2 capsid protein monomers, these amino acids were almost totally degraded within 2 min by chlorine dioxide. Only tyrosine reacted with chlorine dioxide following treatment of the intact virion with disinfectant. Even though the degradation of tyrosine residues occurred at a much slower rate than the rate of virus inactivation, the protein component of f2 virus appeared to be the site of the lethal lesion produced by chlorine dioxide. These tyrosine reactions with chlorine dioxide appeared to alter the virus such that specific attachment was inhibited.     

Concentration of hepatitis A virus

Cell culture adapted hepatitis A virus (HAV) in 10 and 50 l. of seeded distilled water was respectively concentrated approx. 3300 and 17,000 fold by adsorption-elution on cellulose membrane. HAV (strain CF 53) was adsorbed at pH 4.0 with 0.15 M NaCl to the cellulose filters and eluted by 3% beef-extract at pH 8.5. Eluted virus was further concentrated by precipitation by polyethylene glycol 6000. Hepatitis A antigen (HAAg) was detected by radioimmunoassay and infectious virus was quantified by cell culture titration. The average of HAAg recovery was 76% for 101. and 85% for 501., whereas the average recovery for infectious virus was respectively 89 and 97%. The sensitivity of the method was tested by contaminating 101. with 16 TCID₅₀ only; 63% of initial infectious virus were recovered.     

Novel measurement system for respiratory aerosols and droplets in indoor environments

The SARS-CoV-2 pandemic has created a great demand for a better understanding of the spread of viruses in indoor environments. A novel measurement system consisting of one portable aerosol-emitting mannequin (emitter) and a number of portable aerosol-absorbing mannequins (recipients) was developed that can measure the spread of aerosols and droplets that potentially contain infectious viruses. The emission of the virus from a human is simulated by using tracer particles solved in water. The recipients inhale the aerosols and droplets and quantify the level of solved tracer particles in their artificial lungs simultaneously over time. The mobile system can be arranged in a large variety of spreading scenarios in indoor environments and allows for quantification of the infection probability due to airborne virus spreading. This study shows the accuracy of the new measurement system and its ability to compare aerosol reduction measures such as regular ventilation or the use of a room air purifier.     

The cytotoxicity and antimicrobial efficiency of Moringa oleifera seeds extracts

The cytotoxicity and antimicrobial activity of different Moringa oleifera seeds extracts were tested against Scenedesmus obliquus (green algae), Escherichia coli ATCC 13706, Pseudomonas aeruginosa ATCC10145, Staphylococcus aureus NAMRU 3 25923, Bacillus sterothermophilus (bacterial strains) and Herpes Simplex virus type 1 (HSV 1) and Polio virus type 1 (sabin vaccine). Fixed oil extracted from the seeds was found to activate the growth of Scenedesmus obliquus with high algal biomass production. Aqueous methanolic extracts (LC50 207.5 mg/L) and water extract (LC50 287.5 mg/L) has a cytotoxicity effect on Scenedesmus growth. On the other hand, the antibacterial effects of fixed oil, aqueous methanolic extract and water extract concentrations showed a fluctuation in its effects. Although, Ps. aeruginosa was more resistant to all M. oleifera extracts, B. sterothermophilus was more sensitive than other organisms to all extracts. The effect of aqueous methanolic extract and fixed oil on HSV1 was highly similar, 52.22% and 45.2%. Very low activity was observed for fixed oil on PV1.     

Indigenous somatic coliphage removal from a real municipal wastewater by a submerged membrane bioreactor

The membrane bioreactor (MBR) features many advantages, such as its excellent effluent quality and compactness. Moreover, the MBR is well known for its disinfectant capacity. This paper investigates virus removal performance for municipal wastewater using a submerged MBR and the operational conditions affecting the virus removal using indigenous somatic coliphages (SC) as an indicator for viruses. The results revealed that the municipal wastewater acquired by the Qinghe Municipal Wastewater Treatment Plant, Beijing, contained an SC concentration of (2.81 ± 1.51) × 10⁴ PFU ml⁻¹, which varies seasonally due to spontaneous decay. In the MBR system, the biomass process dominates SC removal. Membrane rejection is an essential supplement of biomass process for SC removal. In this paper, the relative contributions of biomass process and membrane rejection during the start-up and steady operational periods are discussed in detail. The major factors affecting SC removal are biodegradation, membrane pore size, and gel layer formation on the membrane. During long-term experiments, it was demonstrated that high inoculated sludge concentration, long hydraulic retention time, moderate fouling layer, and non-frequent chemical cleaning are favorable for high SC removal in MBR systems.