Introduction:Human immunodeficiency virus(HIV)voluntary counseling and testing(VCT)clinics play a critical role in identifying and diagnosing HIV cases.This study aimed to describe the trend of HIV positivity rate(HPR...Introduction:Human immunodeficiency virus(HIV)voluntary counseling and testing(VCT)clinics play a critical role in identifying and diagnosing HIV cases.This study aimed to describe the trend of HIV positivity rate(HPR)among Chinese VCT clinics between 2015 and 2022.Methods:This study utilized data from the China Information System for Disease Control and Prevention to analyze the trend in the HPR for VCT clinics from 2015 to 2022.The HPR was calculated by dividing the number of newly-reported HIV cases by the number of HIV tests,multiplied by 100%.To identify temporal and spatial trends in the HPR,we employed joinpoint regression analysis and the Getis-Ord hotspot analysis.Results:From 2015 to 2022,VCT clinics in China performed a total of 22,075,386 HIV tests,leading to the identification of 260,353 HIV cases,resulting in a HPR of 1.18%.The HPR consistently declined over the study period,with an average annual percent change(AAPC)of−7.5%(95%confidence interval:−12.6%,−2.2%,P<0.05).The number of HPR hotspots also decreased from 41 in 2015 to 23 in 2022.These HPR hotspots were primarily located in Yunnan,Sichuan,Guangdong,and Guangxi provincial-level administrative divisions(PLADs).Among the 31 PLADs,16 showed a significant decrease in HPR during the study period(AAPC<0,PAAPC<0.05).Conclusions:VCT clinics in China have played a significant role in identifying HIV cases.The declining HPR observed in these clinics may indicates the progress has been made in some degree in mitigating HIV among high-risk populations.Therefore,it is crucial to further improving the utilization of VCT clinics for HIV testing.展开更多
Summary What is already known about this topic?An estimated 1,400 new cases of human immunodeficiency virus(HIV)occur every day among youths globally.However,HIV distribution among youth aged 15–24 years in China has...Summary What is already known about this topic?An estimated 1,400 new cases of human immunodeficiency virus(HIV)occur every day among youths globally.However,HIV distribution among youth aged 15–24 years in China has not been researched extensively.展开更多
Summary What is already known about this topic?There are 4,000 new HIV infections every day worldwide,and 31%of which are in adolescents aged 15–24 years old.However,previous study is not aware of the distribution of...Summary What is already known about this topic?There are 4,000 new HIV infections every day worldwide,and 31%of which are in adolescents aged 15–24 years old.However,previous study is not aware of the distribution of out-of-school youth among this age group.展开更多
In this study,with La_(0.8)Sr_(0.2)Cr_(0.5)Fe_(0.5)O_(3-δ)(LSCrF)and Ce_(0.8)Sm_(0.2)O_(1.9)(SDC)taken as the electronic conducting phase and the oxide ion conductor,respectively,dual-phase composite ceramic membrane...In this study,with La_(0.8)Sr_(0.2)Cr_(0.5)Fe_(0.5)O_(3-δ)(LSCrF)and Ce_(0.8)Sm_(0.2)O_(1.9)(SDC)taken as the electronic conducting phase and the oxide ion conductor,respectively,dual-phase composite ceramic membranes with or without 3%(in mole)Y_(2)O_(3) stable ZrO_(2)(3YSZ)support were prepared and tested as oxygen separation membranes.Then,the oxygen transmission performance was tested by the electrochemical method based on the limiting current.The results obtained with this method coincide with those acquired by means of gas chromatography.Furthermore,the dependences of oxygen permeation rate on oxygen partial pressure,temperature and ceramic membrane thickness were analyzed.When air was used as the sweeping gas on the porous 3YSZ supported SDC-LSCrF dual-phase membrane,the oxygen permeation rate can reach 0.73,0.82,0.90 and 0.97 mL cm^(-2) min^(-1) at 650,700,750 and 800℃,respectively.展开更多
Oxygen surface exchange and oxygen chemical diffusion coefficients of LaNi_(0.4)Fe_(0.6)O_(3-δ)ceramics are determined via conductivity relaxation method after stepwise change of temperature in the range of 700-950℃...Oxygen surface exchange and oxygen chemical diffusion coefficients of LaNi_(0.4)Fe_(0.6)O_(3-δ)ceramics are determined via conductivity relaxation method after stepwise change of temperature in the range of 700-950℃in air and Ar/O2 gas flow at oxygen partial pressures(p_(o2))of 4 Pa,18 Pa,37 Pa,47 Pa and 59 Pa.The highest conductivity(about 160 S·cm^(-1))is found at 950℃in air.No oxygen exchange(δ=0)below 700℃is observed in the investigated p_(o2) range.The oxygen exchange coefficients determined in reduction mode are higher than those determined in oxidation mode.This is explained by clusterization of oxygen vacancies on the surface of the sample investigated in oxidation mode.The opposite tendency is found for chemical diffusion coefficients.Unlike surface,the oxygen vacancies of the volume region are probably not clustered and have predetermined the higher oxygen diffusion mobility of the sample treated in oxidation mode.展开更多
基金Supported by National Science and Technology Major Project of China(2017ZX10201101-002-006).
文摘Introduction:Human immunodeficiency virus(HIV)voluntary counseling and testing(VCT)clinics play a critical role in identifying and diagnosing HIV cases.This study aimed to describe the trend of HIV positivity rate(HPR)among Chinese VCT clinics between 2015 and 2022.Methods:This study utilized data from the China Information System for Disease Control and Prevention to analyze the trend in the HPR for VCT clinics from 2015 to 2022.The HPR was calculated by dividing the number of newly-reported HIV cases by the number of HIV tests,multiplied by 100%.To identify temporal and spatial trends in the HPR,we employed joinpoint regression analysis and the Getis-Ord hotspot analysis.Results:From 2015 to 2022,VCT clinics in China performed a total of 22,075,386 HIV tests,leading to the identification of 260,353 HIV cases,resulting in a HPR of 1.18%.The HPR consistently declined over the study period,with an average annual percent change(AAPC)of−7.5%(95%confidence interval:−12.6%,−2.2%,P<0.05).The number of HPR hotspots also decreased from 41 in 2015 to 23 in 2022.These HPR hotspots were primarily located in Yunnan,Sichuan,Guangdong,and Guangxi provincial-level administrative divisions(PLADs).Among the 31 PLADs,16 showed a significant decrease in HPR during the study period(AAPC<0,PAAPC<0.05).Conclusions:VCT clinics in China have played a significant role in identifying HIV cases.The declining HPR observed in these clinics may indicates the progress has been made in some degree in mitigating HIV among high-risk populations.Therefore,it is crucial to further improving the utilization of VCT clinics for HIV testing.
文摘Summary What is already known about this topic?An estimated 1,400 new cases of human immunodeficiency virus(HIV)occur every day among youths globally.However,HIV distribution among youth aged 15–24 years in China has not been researched extensively.
文摘Summary What is already known about this topic?There are 4,000 new HIV infections every day worldwide,and 31%of which are in adolescents aged 15–24 years old.However,previous study is not aware of the distribution of out-of-school youth among this age group.
基金The financial support from the National Natural Science Foundation of China(No.51672297 and No.51836004)is highly appreciated.
文摘In this study,with La_(0.8)Sr_(0.2)Cr_(0.5)Fe_(0.5)O_(3-δ)(LSCrF)and Ce_(0.8)Sm_(0.2)O_(1.9)(SDC)taken as the electronic conducting phase and the oxide ion conductor,respectively,dual-phase composite ceramic membranes with or without 3%(in mole)Y_(2)O_(3) stable ZrO_(2)(3YSZ)support were prepared and tested as oxygen separation membranes.Then,the oxygen transmission performance was tested by the electrochemical method based on the limiting current.The results obtained with this method coincide with those acquired by means of gas chromatography.Furthermore,the dependences of oxygen permeation rate on oxygen partial pressure,temperature and ceramic membrane thickness were analyzed.When air was used as the sweeping gas on the porous 3YSZ supported SDC-LSCrF dual-phase membrane,the oxygen permeation rate can reach 0.73,0.82,0.90 and 0.97 mL cm^(-2) min^(-1) at 650,700,750 and 800℃,respectively.
基金support of the European Union,the Government of Saxony,Germany(SAB Project 14252)HASYLAB/DESY for X-ray diffraction measurements with synchrotron radiation(Project I-20090287).
文摘Oxygen surface exchange and oxygen chemical diffusion coefficients of LaNi_(0.4)Fe_(0.6)O_(3-δ)ceramics are determined via conductivity relaxation method after stepwise change of temperature in the range of 700-950℃in air and Ar/O2 gas flow at oxygen partial pressures(p_(o2))of 4 Pa,18 Pa,37 Pa,47 Pa and 59 Pa.The highest conductivity(about 160 S·cm^(-1))is found at 950℃in air.No oxygen exchange(δ=0)below 700℃is observed in the investigated p_(o2) range.The oxygen exchange coefficients determined in reduction mode are higher than those determined in oxidation mode.This is explained by clusterization of oxygen vacancies on the surface of the sample investigated in oxidation mode.The opposite tendency is found for chemical diffusion coefficients.Unlike surface,the oxygen vacancies of the volume region are probably not clustered and have predetermined the higher oxygen diffusion mobility of the sample treated in oxidation mode.
