Clinical characteristics of 310 SARS-CoV-2 Omicron variant patients and comparison with Delta and Beta variant patients in China

Although the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)Omicron variant has spread,data on the clinical characteristics of infected patients are limited.In this study,the demographic,clinical characteristics,and laboratory data of 310 SARS-CoV-2 Omicron variant patients treated at Haihe Hospital of Tianjin were collected and analyzed.Information on these patients was compared to 96 patients with the Delta variant of concern(VOC)and 326 patients with the Beta VOC during the previous coronavirus disease 2019(COVID-19)outbreak in Harbin.Of the 310 patients infected with the Omicron variant,the median age was 35 years.Most patients were clinically classified as mild(57.74%),and the most common symptoms were cough(48.71%),fever(39.35%),and sore throat(38.26%).The results for different vaccination groups in the Omicron group showed that the median of“SARS-CoV-2 specific IgG”after 2 or 3 doses of vaccination was higher than the unvaccinated group(all Ps<0.05).Older age was associated with a higher proportion of moderate cases and lower asymptomatic and mild cases based on clinical classifications.Compared to the Delta and Beta groups,the median age of the Omicron group was younger.The total number of asymptomatic patients and mild patients in the Omicron virus group was higher than the Delta and Beta groups(60.97%vs.54.17%vs.47.55%).This study presented the clinical characteristics of the first group of patients infected with the Omicron variant in Tianjin,China,and compared their clinical features with patients infected by the Delta and Beta variants,which would increase our understanding of the characteristics of SARS-CoV-2 Omicron variant.

Study on the influencing factors to reduce the recovery time of superconducting tapes and coils for the DC superconducting fault current limiter applications

Superconducting fault current limiters(SFCLs)are important in improving the stability of electrical power systems.However,the existing resistive-type DC SFCL has a long re-covery time,which cannot meet the requirements of power system auto-reclosure.Thus,it is necessary to investigate the methods of reducing recovery time of SFCLs.In the simulations on superconducting tapes,there is a lack of investigation about the effects of design factors of superconducting tapes and coils such as material,thickness,coil radius,coil winding method on recovery characteristics.The objective of this study is to obtain the effects of material and geometric properties of superconducting tapes and coils on recovery characteristics and obtain methods to reduce the recovery time.The recovery times under different conducting currents are also compared by simulations and exper-iments to verify simulation accuracy.The maximum error is below 40%and most of the cases have an error below 10%.Besides,by increasing tape thickness,the recovery time can be reduced by 22%.Tape materials and coil winding methods can be designed ac-cording to the auto-reclosure and current-limiting requirements of the power systems.The research provided directions for the design of superconducting tape and super-conducting coil for resistive-type DC SFCLs.