Effect of incubation period on epidemic spreading in complex networks

We study the effect of incubation period on epidemic spreading in the Barabasi-Albert scale-free network and the Watts-Strogatz small world network by using a Suspectable-Incubated-Infected-Suspectable model. Our analytical investigations show that the epidemic threshold is independent of incubation period in both networks, which is verified by our large-scale simulation results. We also investigate the effect of incubation period on the epidemic dynamics in a supercritical regime. It is found that with the increase of incubation period Ω, a damped oscillation evolution of ρT （the ratio of persons in incubated state） appears and the time needed to reach a saturation value increases. Moreover, the steady value of ρT increases and approaches to an asymptotic constant with the value of Ω increasing. As a result, the infected ratio ρI decreases with the increase of Ω according to a power law.

Asymptotic Periodicity in the Fecally-Orally Epidemic Model in a Heterogeneous Environment

To understand the influence of seasonal periodicity and environmental heterogeneity on the transmission dynamics of an infectious disease, we consider asymptotic periodicity in the fecally-orally epidemic model in a heterogeneous environment. By using the next generation operator and the related eigenvalue problems, the basic reproduction number is introduced and shows that it plays an important role in the existence and non-existence of a positive T-periodic solution. The sufficient conditions for the existence and non-existence of a positive T-periodic solution are provided by applying upper and lower solutions method. Our results showed that the fecally-orally epidemic model in a heterogeneous environment admits at least one positive T-periodic solution if the basic reproduction number is greater than one, while no T-periodic solution exists if the basic reproduction number is less than or equal to one. By means of monotone iterative schemes, we construct the true positive solutions. The asymptotic behavior of periodic solutions is presented. To illustrate our theoretical results, some numerical simulations are given. The paper ends with some conclusions and future considerations.

Investigation and Research on the Psychological Status of Children and Adolescents During the Epidemic Period of COVID-19

Objective:The paper was to analyze the investigation and study of the psychological status of children and adolescents during the epidemic period of COVID-19.Methods:From March 5th to 11th,2020,1766 students from 8 to 18 years old in Yan'an area were taken as the research objects,and the psychological characteristics of this group of people during the epidemic period of COVID-19 were analyzed by the online questionnaires.Results:In the questionnaire,all children and adolescents were in good psychological conditions,and they had not shown serious negative psychological emotions,and they attached great importance to COVID-19.Conclusion:The psychological changes of children and adolescents during the epidemic period of COVID-19 are diverse.Most children and adolescents have a good mental state,and a few have negative psychological emotions.It can strengthen the psychological management of children and adolescents during the epidemic,and promote the healthy growth of children and adolescents clinically.

STABILITY OF AN SEIS EPIDEMIC MODEL WITH CONSTANT RECRUITMENT AND A VARYING TOTAL POPULATION SIZE

This paper considers an SEIS epidemic model with infectious force in the latent period and a general population-size dependent contact rate. A threshold parameter R is identified. If R≤1, the disease-free equilibrium O is globally stable. If R〉1, there is a unique endemic equilibrium and O is unstable. For two important special cases of bilinear and standard incidence ,sufficient conditions for the global stability of this endemic equilibrium are given. The same qualitative results are obtained provided the threshold is more than unity for the corresponding SEIS model with no infectious force in the latent period. Some existing results are extended and improved.

Stochastic SIR Household Epidemic Model with Misclassification

In this work, we developed a theoretical framework leading to misclassification of the final size epidemic data for the stochastic SIR (Susceptible-Infective-Removed), household epidemic model, with false negative and false positive misclassification probabilities. Maximum likelihood based algorithm is then employed for its inference. We then analyzed and compared the estimates of the two dimensional model with those of the three and four dimensional models associated with misclassified final size data over arrange of theoretical parameters, local and global infection rates and corresponding proportion infected in the permissible region, away from its boundaries and misclassification probabilities. The adequacies of the three models to the final size data are examined. The four and three-dimensional models are found to outperform the two dimensional model on misclassified final size data.

The Effect of State-Dependent Control for an SIRS Epidemic Model with Varying Total Population

Based on the mechanism of prevention and control of infectious disease, we propose, in this paper, an SIRS epidemic model with varying total population size and state-dependent control, where the fraction of susceptible individuals in population is as the detection threshold value. By the Poincaré map, theory of differential inequalities and differential equation geometry, the existence and orbital stability of the disease-free periodic solution are discussed. Theoretical results show that by state-dependent pulse vaccination we can make the proportion of infected individuals tend to zero, and control the transmission of disease in population.

基于风险评估模型的传染病预警体系的建立

目的建立一套基于风险评估模型的传染病预警体系,推动传染病管理水平的提升。方法通过搜集、整理最新的研究成果,参考相关的传染病预警评价指标体系的理论框架,构建基于风险评估模型的传染病预警体系。结果本次研究共纳入了12名专家,筛选出了三个一级指标,涉及流行前期指标、典型症状期指标、非典型症状期指标等,同时涉及7个二级指标。体系的必要性平均得分为8.27±0.24分,可获得性平均得分为7.74±0.34分。结论基于风险评估模型的传染病预警体系的建立有利于当地及时掌握传染病流行趋势,并进行调查指标分布趋势分析,然后提出相应的预警方案,可为有效预防传染病提供相关的依据。

小麦条锈病跨区域全周期绿色防控技术体系的构建与应用

小麦条锈病是我国小麦生产上一种跨区域流行的重大病害。1949年以来,我国小麦条锈病研究,治理能力明显提升,发病面积、流行程度、流行频率明显降低,但由于条锈菌Puccinia striiformis f.sp.tritici新毒性小种不断产生和气候异常变化等因素的影响,近年来其流行规律和成灾机制出现了新的变化,发生危害加重,严重威胁小麦生产和国家粮食安全。基于“十二五”以来我国在小麦条锈病菌毒性新小种产生、有性生殖、侵染循环和大区流行规律等方面的最新研究成果,作者在学习和实践以往病害治理经验的基础上,坚持长短结合、标本兼治、分区治理、综合防治的指导思想,制定了“以绿色防控为基础,以全周期管理为重点,以跨区域联防联控为保障”的防控策略,提出了精准监测预报、毒性小种变异监测、早期菌源控制、抗病品种合理布局和应急防控等关键技术,集成构建了全国小麦条锈病跨区域全周期绿色防控技术体系,制定了越夏易变区、冬季繁殖区(越冬区)和春季流行区分区防控技术体系。经在小麦条锈病主要流行区大面积试验示范,取得了防控效果85%以上,化学农药用量减少10%以上,小麦单产提高5%以上的成效。2022年-2023年在全国小麦主产区大范围组织推广应用,有效控制了小麦条锈病严重流行势头,全国病害发生面积出现了新低,有效减轻了灾害损失,保障了国家粮食安全。

后疫情时期线上线下精准衔接的融合式教学模式的探索

随着信息化教学的发展,后疫情时期线上线下教学的衔接与融合势在必行。以成人护理学课程实践为例,以成果导向教育理论为指导,设计并实施线上线下精准衔接的融合式教学模式,并收集其应用反馈。通过课程实践发现,线上线下深度融合教学的必要性得到学生认可,可以形成优势互补,线上学习活动有助于提高课堂教学效果,同时将信息化手段嵌入线下课堂授课,有助于丰富课程的过程性评价。在后续护理学课程教学中,可以进一步验证线上线下融合式教学模式的应用效果,进而推动混合式教学新范式的形成,提高人才培养质量。

后疫情时期动物诊断学课程新形态教学改革探索

在我国高等教育“新农科”建设的新阶段、新形势下,为全面提高教学效果以及应对“后疫情时期”的教学需求,针对动物诊断学课程以往的教学实践中出现的若干问题,展开了一系列的教学改革探索。基于“新形态”教学的动物诊断学课程的教学效果及满意度得到了明显改善,满足了“后疫情时期”教学活动的顺利开展,能够更好地服务于推进动物医学专业“产-学-研-用”体系建设,并具备为行业、为社会培养更多目前急需的具有使命感、责任感的实践型、服务型专业人才的能力,最终服务于国家畜牧兽医产业、生态文明建设等领域的健康可持续发展。

灾后社会景气变动趋势:基于后疫情期的考察

灾后社会景气作为表征性因素,是实质性恢复重建工作中长期潜在的隐蔽公理,对于更好促进灾后恢复重建具有重要的社会意义。通过对原有文献中社会景气概念的修复性界定,指出它不仅仅是主观满意度和信心的问题,更涉及客观景象的整体状况。基于后疫情期主客观社会景气的案例,通过实证比较分析进行具体考察,从而揭示疫灾过后经济社会恢复发展和社会景气回升繁荣的艰难之因。在此基础上,提出加强灾后社会景气研究和监测分析,着眼于宏观、中观、微观层面促进灾后恢复重建和社会景气回升。

Periodic Solution and Ergodic Stationary Distribution of Stochastic SIRI Epidemic Systems with Nonlinear Perturbations

This paper formulates two stochastic nonautonomous SIRI epidemic systems with nonlinear perturbations.The main aim of this study is to investigate stochastic dynamics of the two SIRI epidemic systems and obtain their thresholds.For the nonautonomous stochastic SIRI epidemic system with white noise,the authors provide analytic results regarding the stochastic boundedness,stochastic permanence and persistence in mean.Moreover,the authors prove that the system has at least one nontrivial positive T-periodic solution by using Lyapunov function and Hasminskii’s theory.For the system with Markov conversion,the authors establish sufficient conditions for positive recurrence and existence of ergodic stationary distribution.In addition,sufficient conditions for the extinction of disease are obtained.Finally,numerical simulations are introduced to illustrate the main results.

后疫情时期韧性卫生系统的挑战及建设策略

目的 了解国内外后疫情时期韧性卫生系统面临的现状,为建设我国高韧性卫生系统提出策略。方法 通过回顾国内外文献,总结国内外卫生系统韧性建设中所遭遇的瓶颈及挑战,对卫生系统的弱点与结构性缺陷进行深入分析,提出建议。结果 我国疫情时期韧性卫生系统面临卫生人力资源短缺、应急物资储备体系不完善、卫生筹资结构不合理、卫生信息系统资源冗杂、管理与合作能力不足、医疗卫生服务中断等问题,从卫生人力资源、医疗产品与技术、卫生筹资、卫生信息系统、领导与治理、医疗卫生服务为核心的卫生系统发展等方面对我国韧性卫生系统建设与管理提出建议。结论 在总结国内外后疫情时期卫生系统韧性的基础上,完善我国关于高韧性卫生系统的研究,对建立更加全面而有韧性的卫生服务模式具有重要意义。

民国时期东北中医防治疫病研究述评

民国时期东北地区疫病频发。综合报刊、杂志、档案等相关史料,回顾并总结该时期疫病防治的经验,以期为中医药防治疫病提供参考。疫病流行之际,东北中医传承古道、制定专方、针药并用以防治疫病,重视六气与体质的影响,强调固护正气、激发自愈,注重病后调护与预防,以西医药理与中医思维相融合的方式中西汇通。中医药在当时的疫病防治中发挥了重要作用,回顾并总结早期疫病防治的经验,对于中医药防治疫病具有重要的参考意义。

一类时间周期SIRS扩散传染病模型的渐近传播速度

利用渐近传播速度理论,研究了一类模拟时间周期变化传播环境中疾病传播的SIRS反应扩散传染病模型的渐近传播性质。区别于已有针对SI二维系统的传播速度的结果,该模型中R仓室无法解耦于整个系统,为此需要克服高维和非自治性耦合带来的困难,以证明高维系统渐近传播速度的存在性。首先,借助单调系统渐近传播速度的抽象理论和比较原理证明了染病者I仓室在疾病未入侵区域的传播性质,以此结论为基础,利用整体解结合最大值原理进一步验证了恢复者R仓室在未入侵区域具有类似的传播性质。其次,分别对I和R方程运用比较原理结合一致持久思想和最大值原理分析了其在疾病已入侵区域的一致持久性。由此,得到了划分这两个变化区域的渐近传播速度阈值,即证明了整个系统渐近传播速度的存在性。最后,利用数值方法进一步模拟了时间周期传播环境下疾病已入侵区域更具体的传播动态。

后疫情时代公众新冠疫情威胁感知对心理焦虑的影响机制

尽管世界卫生组织宣布新冠疫情不再是构成国际关注的突发公共卫生事件,但有研究表明疫情对心理健康的危害会长期存在,因此有必要对后疫情时代公众的心理健康问题予以重点关注。本研究采用随机抽样的方法对412名参与者进行了问卷调查,探讨公众对新冠病毒感染的威胁评估是否以及如何对焦虑产生影响。结果表明:(1)公众对新冠感染威胁严重性的感知正向影响心理焦虑,反应效能和自我效能在其中发挥着中介作用;(2)威胁易感性仅能通过反应效能和自我效能的中介作用对焦虑产生正向影响;(3)领悟社会支持能显著缓和威胁严重性对焦虑的影响关系。

平疫结合社区通风系统设计及卫生通过风量平衡计算分析

以河南省郑州市某平疫结合社区为例,介绍了平疫转换涉及的主要建筑功能布局和通风系统设计要求。根据风量平衡公式,计算并分析了在门窗缝隙为0.004m,一脱防护服房间换气次数20h^(-1)条件下,卫生通过区相邻相通房间压差对通风量的影响。在穿防护服房间压力为5Pa,更衣室房间压力为10Pa,二脱防护服房间压力为-5Pa,一脱防护服房间压力为-25Pa时,各房间通风量最小,更衣室送风换气次数为22.9h-1,穿防护服房间送风换气次数为3.4h^(-1),一脱防护服房间送风换气次数为6.9h^(-1),二脱防护服房间排风换气次数为4.2h^(-1)。

梅州市某传染病医院通风系统设计

以梅州市某传染病医院通风系统设计为例,探讨了传染病医院“三区两通道”机械送排风系统的设计原则。从空气处理、压力梯度、气流组织、风量平衡等方面介绍了传染病医院平疫结合下的通风系统设计,为类似项目设计提供参考。

A Prediction Framework for Turning Period Structures in COVID-19 Epidemic and Its Application to Practical Emergency Risk Management

The aim of this paper is first to establish a general prediction framework for turning(period)term structures in COVID-19 epidemic related to the implementation of emergency risk management in the practice,which allows us to conduct the reliable estimation for the peak period based on the new concept of“Turning Period”(instead of the traditional one with the focus on“Turning Point”)for infectious disease spreading such as the COVID-19 epidemic appeared early in year 2020.By a fact that emergency risk management is necessarily to implement emergency plans quickly,the identification of the Turning Period is a key element to emergency planning as it needs to provide a time line for effective actions and solutions to combat a pandemic by reducing as much unexpected risk as soon as possible.As applications,the paper also discusses how this“Turning Term(Period)Structure”is used to predict the peak phase for COVID-19 epidemic in Wuhan from January/2020 to early March/2020.Our study shows that the predication framework established in this paper is capable to provide the trajectory of COVID-19 cases dynamics for a few weeks starting from Feb.10/2020 to early March/2020,from which we successfully predicted that the turning period of COVID-19 epidemic in Wuhan would arrive within one week after Feb.14/2020,as verified by the true observation in the practice.The method established in this paper for the prediction of“Turning Term(Period)Structures”by applying COVID-19 epidemic in China happened early 2020 seems timely and accurate,providing adequate time for the government,hospitals,essential industry sectors and services to meet peak demands and to prepare aftermath planning,and associated criteria for the Turning Term Structure of COVID-19 epidemic is expected to be a useful and powerful tool to implement the so-called“dynamic zero-COVID-19 policy”ongoing basis in the practice.

建筑策划视角下的社区服务中心设计初探

随着新冠疫情防控的常态化,社区服务中心日渐成为防控关键节点。在“平疫结合”及平遥古城更新的背景下,文章对社区服务中心设计进行了深入探讨,并运用建筑策划“信息矩阵法”相关理论,结合功能关系分析工具与平台,旨在解决建筑设计前期阶段从概念到空间转换的问题,即策划阶段建筑空间布局的合理性。信息矩阵法可以衔接建筑概念阶段和建筑空间构想阶段,实现多专业协同设计;提出了建筑策划体系之下的具体的建筑设计路径,包括建筑策划的工具和方法等。