This paper presents a novel approach for assessing the precision of the wet refractivity field using BDS （BeiDou navigation satellite system） simulations only,GPS,and BDS＋GPS for the Shenzhen and Hongkong GNSS netw...This paper presents a novel approach for assessing the precision of the wet refractivity field using BDS （BeiDou navigation satellite system） simulations only,GPS,and BDS＋GPS for the Shenzhen and Hongkong GNSS network.The simulations are carried out by adding artificial noise to a real observation dataset.Instead of using the δ and σ parameters computed from slant wet delay,as in previous studies,we employ the Bias and RMS parameters,computed from the tomography results of total voxels,in order to obtain a more direct and comprehensive evaluation of the precision of the refractivity field determination.The results show that：（1） the precision of tropospheric wet refractivity estimated using BDS alone （only 9 satellites used） is basically comparable to that of GPS; （2） BDS＋GPS （as of current operation） may not be able to significantly improve the data＇s spatial density for the application of refractivity tomography; and （3） any slight increase in the precision of refractivity tomography,particularly in the lower atmosphere,bears great significance for any applications dependent on the Chinese operational meteorological service.展开更多
The global outbreak of the coronavirus disease 2019(COVID-19) led to the suspension of most treatments with assisted reproductive technique(ART). However, with the recent successful control of the pandemic in China, t...The global outbreak of the coronavirus disease 2019(COVID-19) led to the suspension of most treatments with assisted reproductive technique(ART). However, with the recent successful control of the pandemic in China, there is an urgent public need to resume full reproductive care. To determine whether the COVID-19 pandemic had any adverse effects on female fertility and the pregnancy outcomes of women undergoing ART, a systematic review and meta-analysis was conducted using the electronic Chinese and English databases. Dichotomous outcomes were summarized as prevalence, and odds ratios(ORs)and continuous outcomes as standardized mean difference(SMD) with 95% confidence interval(CI). The risk of bias and subgroup analyses were assessed using Stata/SE 15.1 and R 4.1.2. The results showed that compared with women treated by ART in the pre-COVID-19 time frame, women undergoing ART after the COVID-19 pandemic exhibited no significant difference in the clinical pregnancy rate(OR 1.07, 95% CI 0.97 to 1.19;I^(2)=0.0%), miscarriage rate(OR 0.95, 95% CI 0.79 to1.14;I^(2)=38.4%), embryo cryopreservation rate(OR 2.90, 95% CI 0.17 to 48.13;I^(2)=85.4%), and oocyte cryopreservation rate(OR 0.30, 95% CI 0.03 to 3.65;I^(2)=81.6%). This review provided additional evidence for gynecologists to guide the management of women undergoing ART treatment during the COVID-19 pandemic timeframe.展开更多
基金supported by the National Basic ResearchDevelopment (973) Program of China (Grant No. 2012CB955903)+1 种基金the National Natural Science Foundation of China (Grant No. 20907047 and Grant No. 71373131)National Industry-specific Topics (Grant No.GYHY 201406078)
文摘This paper presents a novel approach for assessing the precision of the wet refractivity field using BDS （BeiDou navigation satellite system） simulations only,GPS,and BDS＋GPS for the Shenzhen and Hongkong GNSS network.The simulations are carried out by adding artificial noise to a real observation dataset.Instead of using the δ and σ parameters computed from slant wet delay,as in previous studies,we employ the Bias and RMS parameters,computed from the tomography results of total voxels,in order to obtain a more direct and comprehensive evaluation of the precision of the refractivity field determination.The results show that：（1） the precision of tropospheric wet refractivity estimated using BDS alone （only 9 satellites used） is basically comparable to that of GPS; （2） BDS＋GPS （as of current operation） may not be able to significantly improve the data＇s spatial density for the application of refractivity tomography; and （3） any slight increase in the precision of refractivity tomography,particularly in the lower atmosphere,bears great significance for any applications dependent on the Chinese operational meteorological service.
基金supported by the Health High-Level Talent Training Project (Innovative Talents)the Health Commission of Zhejiang Province (File [2021] 40)+1 种基金the 151 Talent Project (Second Level)Zhejiang Province Human Resources and Social Security Department (File [2018] 126), China。
文摘The global outbreak of the coronavirus disease 2019(COVID-19) led to the suspension of most treatments with assisted reproductive technique(ART). However, with the recent successful control of the pandemic in China, there is an urgent public need to resume full reproductive care. To determine whether the COVID-19 pandemic had any adverse effects on female fertility and the pregnancy outcomes of women undergoing ART, a systematic review and meta-analysis was conducted using the electronic Chinese and English databases. Dichotomous outcomes were summarized as prevalence, and odds ratios(ORs)and continuous outcomes as standardized mean difference(SMD) with 95% confidence interval(CI). The risk of bias and subgroup analyses were assessed using Stata/SE 15.1 and R 4.1.2. The results showed that compared with women treated by ART in the pre-COVID-19 time frame, women undergoing ART after the COVID-19 pandemic exhibited no significant difference in the clinical pregnancy rate(OR 1.07, 95% CI 0.97 to 1.19;I^(2)=0.0%), miscarriage rate(OR 0.95, 95% CI 0.79 to1.14;I^(2)=38.4%), embryo cryopreservation rate(OR 2.90, 95% CI 0.17 to 48.13;I^(2)=85.4%), and oocyte cryopreservation rate(OR 0.30, 95% CI 0.03 to 3.65;I^(2)=81.6%). This review provided additional evidence for gynecologists to guide the management of women undergoing ART treatment during the COVID-19 pandemic timeframe.
