Study on the Effect of Behavioral Interventions Based on the Theory of“Knowledge,Attitude,Practice”on Tuberculosis Cognitive Level of Close Contacts

Objective:Based on the theory of“Knowledge,Attitude,Practice,”health education was carried out for close contact with tuberculosis(TB)at a university in Beijing,and its impact on the students’awareness of TB was studied.This study could provide a reference for effective health education interventions among close contacts of TB in undergraduates.Methods:102 undergraduates who had close contact with one confirmed case of pulmonary TB in April 2021 at a university were randomly divided into a control group and an intervention group.The intervention group was given the“Knowledge,Attitude,Practice”health education intervention by professionally trained doctors,and were asked to complete a self-designed TB-related questionnaire before and after the intervention.Both groups performed the Tuberculin Skin Test(TST)and chest X-ray(CR)examination.Results:The rate of the TST test was 18.6%,and CR examination showed 0 cases of pulmonary TB.The survey results showed that the TB awareness rate(96.1%,49/51)in the intervention group was significantly higher than that of the control group(51.0%,26/51),and the differences in awareness rate between the two groups were statistically significant(P<0.05).Regarding the attitude/skills toward TB,the prevalence rate of tuberculosis-related attitude/behavior in the intervention group(94.1%,47/51)was significantly higher than that of the control group(60.8%,31/51),and the differences between the two groups were statistically significant(P<0.05).Conclusion:Both self-controlled and parallel-controlled studies showed that the health education intervention of“Knowledge,Attitude,Practice”improved the awareness of TB among close contacts of TB in undergraduates.

Serological Study of An Imported Case of Middle East Respiratory Syndrome and His Close Contacts in China, 2015

The first imported Middle East respiratory syndrome （MERS） case in China was identified in May 2015. We determined the kinetics of antibody （IgG and IgM） and neutralizing antibodies against MERS-coronavirus （MERS-CoV） in this case before discharge. Moreover, no seroconversion was found among 53 close contacts by anti-MERS IgG antibody enzyme-linked immunosorbent assay （ELISA） of paired serum samples. These findings suggest that neither community nor nosocomial transmission of MERS-CoV occurred in China.

Suspected Close Contacts as the Pilot Indicator of the Growth Trend of Confirmed Population During the COVID-19 Pandemic: A Simulation Approach

Regarding to the actual situation of the new coronavirus disease 2019 epidemic,social factors should be taken into account and the increasing growth trend of confirmed populations needs to be explained.A proper model needs to be established,not only to simulate the epidemic,but also to evaluate the future epidemic situation and find a pilot indicator for the outbreak.The original susceptible-infectious-recover model is modified into the susceptible-infectious-quarantine-confirm-recover combined with social factors(SIDCRL)model,which combines the natural transmission with social factors such as external interventions and isolation.The numerical simulation method is used to imitate the change curve of the cumulative number of the confirmed cases and the number of cured patients.Furthermore,we investigate the relationship between the suspected close contacts(SCC)and the final outcome of the growth trend of confirmed cases with a simulation approach.This article selects four representative countries,that is,China,South Korea,Italy,and the United States,and gives separate numerical simulations.The simulation results of the model fit the actual situation of the epidemic development and reasonable predictions are made.In addition,it is analyzed that the increasing number of SCC contributes to the epidemic outbreak and the prediction of the United States based on the population of the SCC highlights the importance of external intervention and active prevention measures.The simulation of the model verifies its reliability and stresses that observable variable SCC can be taken as a pilot indicator of the coronavirus disease 2019 pandemic.

Clinical characteristics of 24 asymptomatic infections with COVID-19 screened among close contacts in Nanjing,China

Previous studies have showed clinical characteristics of patients with the 2019 novel coronavirus disease(COVID-19)and the evidence of person-to-person transmission.Limited data are available for asymptomatic infections.This study aims to present the clinical characteristics of 24 cases with asymptomatic infection screened from close contacts and to show the transmission potential of asymptomatic COVID-19 virus carriers.Epidemiological investigations were conducted among all close contacts of COVID-19 patients(or suspected patients)in Nanjing,Jiangsu Province,China,from Jan 28 to Feb 9,2020,both in clinic and in community.Asymptomatic carriers were laboratory-confirmed positive for the COVID-19 virus by testing the nucleic acid of the pharyngeal swab samples.Their clinical records,laboratory assessments,and chest CT scans were reviewed.As a result,none of the 24 asymptomatic cases presented any obvious symptoms while nucleic acid screening.Five cases(20.8%)developed symptoms(fever,cough,fatigue,etc.)during hospitalization.Twelve(50.0%)cases showed typical CT images of ground-glass chest and 5(20.8%)presented stripe shadowing in the lungs.The remaining 7(29.2%)cases showed normal CT image and had no symptoms during hospitalization.These 7 cases were younger(median age:14.0 years;P=0.012)than the rest.None of the 24 cases developed severe COVID-19 pneumonia or died.The median communicable period,defined as the interval from the first day of positive nucleic acid tests to the first day of continuous negative tests,was 9.5 days(up to 21 days among the 24 asymptomatic cases).Through epidemiological investigation,we observed a typical asymptomatic transmission to the cohabiting family members,which even caused severe COVID-19 pneumonia.Overall,the asymptomatic carriers identified from close contacts were prone to be mildly ill during hospitalization.However,the communicable period could be up to three weeks and the communicated patients could develop severe illness.These results highlighted the importance of close contact tracing and longitudinally surveillance via virus nucleic acid tests.Further isolation recommendation and continuous nucleic acid tests may also be recommended to the patients discharged.

My First Close Contact with Japanese Kagura

The first time that I heard the concept of the "Japanese Kagura" was in March, 2012 when a working group of the Chinese People’s Association for Peace and Disarmament was paying a visit to Hiroshima, Japan. When Mr. Sen Nakata, President of NPO "The World", an old friend of the Chinese Association for International Understanding (CAFIU), enthusiastically

Facilities for Centralized Isolation and Quarantine for the Observation and Treatment of Patients with COVID-19

The coronavirus disease 2019(COVID-19)pandemic increased the burden on many healthcare systems and in the process,exposed the need for medical resources and physical space.While few studies discussed the efficient utilization of medical resources and physical space so far.Therefore,this study aimed to summarize experiences related to facilities used for centralized isolation for medical observation and treatment during the COVID-19 pandemic in China and to provide suggestions to further improve the management of confirmed cases,suspected cases,and close contacts.In China,three types of facilities for centralized isolation(Fangcang shelter hospitals,refitted non-designated hospitals,and quarantine hotels)underwent retrofitting for the treatment and isolation of confirmed and suspected cases.These facilities mitigated the immediate high demand for space.Moreover,in order to minimize infection risks in these facilities,regulators and governmental agencies implemented new designs,management measures,and precautionary measures to minimize infection risk.Other countries and regions could refer to China’s experience in optimally allocating social resources in response to the COVID-19 pandemic.As a conclusion,government should allocate social resources and construct centralized isolation and quarantine facilities for an emergency response,health authorities should issue regulations for centralized isolation facilities and pay strict attention to the daily management of these facilities,a multidisciplinary administration team is required to support the daily operation of a centralized isolation facility,in-depth studies and international collaboration on the centralized isolation policy are encouraged.

INVESTIGATION OF ENERGY EQUILIBRIUM EQUATION ON CRACK FORMATION OF ELECTRICAL CONTACT SURFACE

Experiment investigations on crack propagation of silver based contact surface are carried out with various currents and contact closed forces.It is found that crack propagation of contact surface is caused by arc energy and contact closed forces.Meanwhile, the energy equilibrium equation of crack propagation of silver based contact material under arc energy and contact closed force is provided.

Predominance of inhalation route in short-range transmission of respiratory viruses:Investigation based on computational fluid dynamics

During the coronavirus disease 2019 pandemic,short-range virus transmission has been observed to have a higher risk of causing infection than long-range virus transmission.However,the roles played by the inhalation and large droplet routes cannot be distinguished in practice.A recent analytical study revealed the predominance of short-range inhalation over the large droplet spray route as causes of respiratory infections.In the current study,short-range exposure was analyzed via computational fluid dynamics(CFD)simulations using a discrete phase model.Detailed facial membranes,including eyes,nostrils,and a mouth,were considered.In CFD simulations,there is no need for a spherical approximation of the human head for estimating deposition nor the“anisokinetic aerosol sampling”approximation for estimating inhalation in the analytical model.We considered two scenarios(with two spheres[Scenario 1]and two human manikins[Scenario 2]),source-target distances of 0.2 to 2 m,and droplet diameters of 3 to 1,500μm.The overall CFD exposure results agree well with data previously obtained from a simple analytical model.The CFD results confirm the predominance of the short-range inhalation route beyond 0.2 m for expiratory droplets smaller than 50μm during talking and coughing.A critical droplet size of 87.5μm was found to differentiate droplet behaviors.The number of droplets deposited on the target head exceeded those exposed to facial membranes,which implies a risk of exposure through the immediate surface route over a short range.

Assessing the effectiveness of the intervention measures of COVID-19 in China based on dynamical method

Normalized interventions were implemented in different cities in China to contain the outbreak of COVID-19 before December 2022.However,the differences in the intensity and timeliness of the implementations lead to differences in final size of the infections.Taking the outbreak of COVID-19 in three representative cities Xi'an,Zhengzhou and Yuzhou in January 2022,as examples,we develop a compartmental model to describe the spread of novel coronavirus and implementation of interventions to assess concretely the effectiveness of Chinese interventions and explore their impact on epidemic patterns.After applying reported human confirmed cases to verify the rationality of the model,we apply the model to speculate transmission trend and length of concealed period at the initial spread phase of the epidemic(they are estimated as 10.5,7.8,8.2 days,respectively),to estimate the range of basic reproduction number(2.9,0.7,1.6),and to define two indexes(transmission rate vt and controlled rate vc)to evaluate the overall effect of the interventions.It is shown that for Zhengzhou,vc is always more than v t with regular interventions,and Xi'an take 8 days to achieve vc>v t twice as long as Yuzhou,which can interpret the fact that the epidemic situation in Xi'an was more severe.By carrying out parameter values,it is concluded that in the early stage,strengthening the precision of close contact tracking and frequency of large-scale nucleic acid testing of non-quarantined population are the most effective on controlling the outbreaks and reducing final size.And,if the close contact tracking strategy is sufficiently implemented,at the late stage largescale nucleic acid testing of non-quarantined population is not essential.

Mass screening is a key component to fight against SARS-CoV-2 and return to normalcy

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) had highly transmissible and pathogenic, which caused serious economic loss and hazard topublic health. Different countries have developed strategiesto deal with the COVID-19 pandemic that fit their epidemiological situations, capacities, and values. Mass screeningcombined with control measures rapidly reduced thetransmission of the SARS-CoV-2 infection. The COVID-19pandemic has dramatically highlighted the essential role ofdiagnostics capacity in the control of communicable diseases. Mass screening has been increasingly used to detectsuspected COVID-19 cases and their close contacts, asymptomatic case, patients attending fever clinics, high-riskpopulations, employees, even all population to identifyinfectious individuals. Mass screening is a key component tofight against SARS-CoV-2 and return to normalcy. Here wedescribe the history of mass screening, define the scope ofmass screening, describe its application scenarios, anddiscuss the impact and challenges of using this approach tocontrol COVID-19. We conclude that through a comprehension screening program and strong testing capabilities, massscreening could help us return to normalcy more quickly.

An Analytical Solution of Melting around a Moving Elliptical Heat Source

This paper studies the close-contact melting around a moving, horizontal elliptical heat source thatmelts its way through a phase change material under its own weight. The heat source velocity andthe volume of the material melted are obtained by analysis. The effects of compression coefficient andtemperature distribution in the melt are investigated. The results include that for melting around amoving cylindrical heat source.