Practice of Infection Prevention and Control Strategies in Risk Departments during the COVID-19 Epidemic

Objective: To explore the practice and application of infection prevention and control strategies in risk departments during the COVID-19 epidemic, and to formulate the infection prevention and control measures to provide advice and guidance in risk departments. Methods: According to the latest plan of diagnosis and treatment, prevention and control issued by the National Health Commission, expert advice and consensus, combined with the actual situation in our hospital, a series of infection prevention and control measures of COVID-19 in risk department was formulated. Results: During the epidemic period, the prevention and control measures of nine risk departments including emergency operation, anesthesiology, endoscopy center, blood purification center, otolaryngology, stomatology, medical imaging department, medical cosmetology department and pulmonary function room were established from six aspects, including pre-examination and screening, medical technology control, personnel management, personal protection, environmental disinfection, medical waste disposal, etc. Conclusion: During the epidemic period, the infection prevention and control strategy of risk departments is one of the key links to control the spread of the epidemic, and risk departments must pay attention to and strictly implement various infection prevention and control measures.

Design and development of a synchronized operation control system for Thomson scattering diagnostic on J-TEXT

A Thomson scattering diagnostic system is under construction at the Joint Texas Experimental Tokamak（J-TEXT）. A 1064 nm Nd：YAG laser with 50 Hz repetition rate is used as the laser source. We have used a software for careful and precise control of the laser through serial communication. A time sequence operating system has been developed to synchronize the laser control and data acquisition system with the central control system（CSS）. The system operates commands from the CSS of J-TEXT and generates triggers for the laser and data acquisition system in the proper sequence. It also measures an asynchronous time value that is needed for accurate time stamping. All functions are served by a field-programmable gate array development platform that is suitable for high-speed data and signal processing applications.Several embedded peripherals, including Ethernet and USB 2.0, provide communication with the CSS and the server.

Control measures during the COVID-19 outbreak reduced the transmission of hand,foot,and mouth disease

Control measures during the coronavirus disease 2019(COVID-19)outbreak may have limited the spread of infectious diseases.This study aimed to analyze the impact of COVID-19 on the spread of hand,foot,and mouth disease(HFMD)in China.A mathematical model was established to fit the reported data of HFMD in six selected cities in China's Mainland from 2015 to 2020.The absolute difference(AD)and relative difference(RD)between the reported incidence in 2020,and simulated maximum,minimum,or median incidence of HFMD in 2015-2019 were calculated.The incidence and R effof HFMD have decreased in six selected cities since the outbreak of COVID-19,and in the second half of 2020,the incidence and R effof HFMD have rebounded.The results show that the total attack rate(TAR)in 2020 was lower than the maximum,minimum,and median TAR fitted in previous years in six selected cities(except Changsha City).For the maximum,median,minimum fitted TAR,the range of RD(%)is 42·20-99·20%,36·35-98·41%48·35-96·23%(except Changsha City)respectively.The preventive and control measures of COVID-19 have significantly contributed to the containment of HFMD transmission.

Modelling the Emerging COVID-19 Epidemic and Estimating Intervention Effectiveness—Taiwan,China,2021

Introduction:The coronavirus disease 2019(COVID-19)pandemic recently affected Taiwan,China.This study aimed to calculate the transmissibility of COVID-19 to predict trends and evaluate the effects of interventions.Methods:The data of reported COVID-19 cases was collected from April 20 to May 26,2021,which included daily reported data(Scenario I)and reported data after adjustment(Scenario II).A susceptibleexposed-symptomatic-asymptomatic-recovered model was developed to fit the data.The effective reproductive number(Reff)was used to estimate the transmissibility of COVID-19.Results:A total of 4,854 cases were collected for the modelling.In Scenario I,the intervention has already taken some effects from May 17 to May 26(the Reff reduced to 2.1).When the Reff was set as 0.1,the epidemic was projected to end on July 4,and a total of 1,997 cases and 855 asymptomatic individuals would have been reported.In Scenario II,the interventions were projected as having been effective from May 24 to May 26(the Reff reduced to 0.4).When the Reff was set as 0.1,the epidemic was projected to end on July 1,and a total of 1,482 cases and 635 asymptomatic individuals would have been reported.Conclusion:The epidemic of COVID-19 was projected to end after at least one month,even if the most effective interventions were applied in Taiwan,China.Although there were some positive effects of intervention in Taiwan,China.

Feasibility of Booster Vaccination in High-Risk Populations for Controlling Coronavirus Variants—China,2021

Introduction:Vaccination booster shots are completely necessary for controlling breakthrough infections of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)in China.The study aims to estimate effectiveness of booster vaccines for high-risk populations(HRPs).Methods:A vaccinated Susceptible-Exposed-Symptomatic-Asymptomatic-Recovered/Removed(SEIAR)model was developed to simulate scenarios of effective reproduction number(Reff)from 4 to 6.Total number of infectious and asymptomatic cases were used to evaluated vaccination effectiveness.Results:Our model showed that we could not prevent outbreaks when covering 80%of HRPs with booster unless Reff=4.0 or the booster vaccine had efficacy against infectivity and susceptibility of more than 90%.The results were consistent when the outcome index was confirmed cases or asymptomatic cases.Conclusions:An ideal coronavirus disease 2019(COVID-19)booster vaccination strategy for HRPs would be expected to reach the initial goal to control the transmission of the Delta variant in China.Accordingly,the recommendation for the COVID-19 booster vaccine should be implemented in HRPs who are already vaccinated and could prevent transmission to other groups.

Generation of ultrafast radially polarized pulses through chirp-assisted femtosecond optical parametric amplification

Radially polarized beams characterized by an axially symmetric polarization distribution can be sharply focused to produce strong longitudinal fields in the vicinity.Future applications of these beams will be facilitated by the availability of higher powers and shorter durations.Currently,the ultrafast radially polarized pulse is typically generated via wavefront reconstruction from conventional linearly polarized states.Achievable pulse duration and intensity limits are strictly dependent on extra-cavity optics.Herein,a chirp-assisted near-degenerate type-II parametric process is presented as a pulse-energy-scalable method of accessing ultrafast radially polarized pulses.In a proof-of-principle experiment,the broadband gain balance between the orthogonally polarized signal components was realized via controlling the chirp of the pump pulse.Through an analogous pulseduration transfer effect,the radially polarized signal inherited the temporal and spectral characteristics of the pump pulse and maintained the radial polarization state of each frequency component of the signal.With a shorter pump pulse,the generation of few-cycle radially polarized pulses should be achievable,which may facilitate a wide range of ultrafast applications such as vacuum electron acceleration and high-harmonic generation.

Natural history and cycle threshold values analysis of COVID-19 in Xiamen City,China

Objective:This study elaborated the natural history parameters of Delta variant,explored the differences in detection cycle thresholds(Ct)among cases.Methods:Natural history parameters were calculated based on the different onset time and exposure time of the cases.Intergenerational relationships between generations of cases were calculated.Differences in Ct values of cases by gender,age,and mode of detection were analyzed statistically to assess the detoxification capacity of cases.Results:The median incubation period was 4 days;the detection time for cases decreased from 25 to 7 h as the outbreak continued.The average generation time(GT),time interval between transmission generations(TG)and serial interval(SI)were 3.6±2.6 days,1.67±2.11 days and 1.7±3.0 days.Among the Ct values,we found little differences in testing across companies,but there were some differences in the gender of detected genes.The Ct values continuous to decreased with age,but increased when the age was greater than 60.Conclusion:This epidemic was started from aggregation of factories.It is more reasonable to use SI to calculate the effective reproduction number and the time-varying reproduction number.And the analysis of Ct values can improve the positive detection rate and improve prevention and control measures.