Introduction:Detecting poliovirus infections proves to be highly challenging due to their asymptomatic nature and infectious potential,highlighting the crucial importance of effective detection methods in the context ...Introduction:Detecting poliovirus infections proves to be highly challenging due to their asymptomatic nature and infectious potential,highlighting the crucial importance of effective detection methods in the context of polio eradication efforts.In many countries,including China,the primary approach for identifying polio outbreaks has been through acute flaccid paralysis(AFP)surveillance.In this study,we conducted an evaluation spanning three decades(1993–2022)to assess the effectiveness of AFP surveillance in China.Methods:Data on all AFP cases identified since 1993 and national-level AFP surveillance system quality indicators aligned with the World Health Organization(WHO)standards were collected for analysis.The quality indicators assess surveillance sensitivity,completeness,timeliness of detection notification,case investigation,and laboratory workup.Surveillance sensitivity is determined by the non-polio AFP(NPAFP)detection rate among children under 15 years of age.Results:Between 1993 and 2022,a total of 150,779 AFP cases were identified and reported.Within this pool,surveillance identified 95 cases of wild poliovirus(WPV)and 24 cases due to vaccinederived poliovirus.From 1995 onwards,the detection rate of NPAFP cases consistently adhered to the WHO and national standards of≥1 case per 100,000,falling between 1.38 and 2.76.Starting in 1997,all timeliness indicators consistently achieved the criteria of 80%,apart from the consistency in meeting standards set for the rate of positive specimens sent to the national laboratory.Conclusions:AFP surveillance has been instrumental in China’s accomplishment of maintaining a polio-free status.The ongoing adherence to key performance indicators,ensuring sensitivity and prompt specimen collection,demonstrates that AFP surveillance is proficient in detecting poliovirus in China.As we move into the post-eradication phase,AFP surveillance remains crucial for the sustained absence of polioviruses in the long term.展开更多
Introduction:In recent years,the incidence of measles in China has consistently remained below 1 per 100,000 population,yet the disease has not been eliminated.This study aims to comprehensively analyze the epidemiolo...Introduction:In recent years,the incidence of measles in China has consistently remained below 1 per 100,000 population,yet the disease has not been eliminated.This study aims to comprehensively analyze the epidemiological characteristics of measles from 2005 to 2022,identify high-risk populations and areas,and propose targeted interventions.Methods:We utilized data from the China Disease Prevention and Control Information System for our comprehensive analysis.Spatial autocorrelation was employed to examine the spatial clustering of measles,while spatiotemporal scanning analysis was used to detect spatiotemporal clustering to describe measles epidemiology during the study period.Results:Between 2005 and 2022,732,218 measles cases were reported in China.Overall,the incidence of measles exhibited a downward trend,particularly during the periods of 2008-2011 and 2015-2022.In 2022,the incidence rate reached its historical low at 0.039 per 100,000 population.Measles predominantly affects young children.Since 2017,global spatial clustering has diminished,although hotspot areas persist in the western provinces.Spatial-temporal scanning identified a high-incidence cluster from 2005 to 2008,comprising 15 provinces in the western,central,and northern regions of China.Conversely,from 2016 to 2022,a low-incidence cluster was detected in the southern and central provinces.Conclusions:China has made significant progress in measles prevention and control.The recent low incidence and absence of substantial spatiotemporal clustering indicate that China is nearing measles elimination.However,there is a continuing need to enhance prevention and control efforts among very young children and in historic incidence hotspots in western provinces.Additionally,improving the diagnosis of vaccine-associated rash illnesses is essential.展开更多
What is already known about this topic?The incidences of vaccine-preventable diseases(VPDs)included in the Expanded Program on Immunization in China have decreased significantly in recent decades.What is added by this...What is already known about this topic?The incidences of vaccine-preventable diseases(VPDs)included in the Expanded Program on Immunization in China have decreased significantly in recent decades.What is added by this report?This study summarizes the national incidences of nine VPDs and the seroprevalence of hepatitis B surface antigen(HBsAg)under different immunization strategies from 1950 through 2021 in China.The sharpest decreases in VPD incidence and under-5-year HBsAg seroprevalence occurred during the latest stage of the National Immunization Program.The decreases in VPD incidence were most prominent among children under five years of age.What are the implications for public health practice?These findings provide valuable insights for vaccine value assessment and emphasize the importance of implementing immunization strategies in targeted populations.展开更多
We present a high-energy,hundred-picosecond(ps)pulsed mid-ultraviolet solid-state laser at 266 nm by a direct second harmonic generation(SHG)in a barium borate(BaB_(2)O_(4),BBO)nonlinear crystal.The green pump source ...We present a high-energy,hundred-picosecond(ps)pulsed mid-ultraviolet solid-state laser at 266 nm by a direct second harmonic generation(SHG)in a barium borate(BaB_(2)O_(4),BBO)nonlinear crystal.The green pump source is a 710 mJ,330 ps pulsed laser at a wavelength of 532 nm with a repetition rate of 1 Hz.Under a green pump energy of 710 mJ,a maximum output energy of 253.3 mJ at 266 nm is achieved with 250 ps pulse duration resulting in a peak power of more than 1 GW,corresponding to an SHG conversion efficiency of 35.7%from 532 to 266 nm.The experimental data were well consistent with the theoretical prediction.To the best of our knowledge,this laser exhibits both the highest output energy and highest peak power ever achieved in a hundred-ps/ps regime at 266 nm for BBO-SHG.展开更多
Herbicide tolerance has been the dominant trait introduced during the global commercialization of genetically modified(GM)crops.Herbicide-tolerant crops,especially glyphosate-resistant crops,offer great advantages for...Herbicide tolerance has been the dominant trait introduced during the global commercialization of genetically modified(GM)crops.Herbicide-tolerant crops,especially glyphosate-resistant crops,offer great advantages for weed management;however,despite these benefits,glyphosate-resistant maize(Zea mays L.)has not yet been commercially deployed in China.To develop a new bio-breeding resource for glyphosate-resistant maize,we introduced a codon-optimized glyphosate N-acetyltransferase gene,gat,and the enolpyruvyl-shikimate-3-phosphate synthase gene,gr79-epsps,into the maize variety B104.We selected a genetically stable high glyphosate resistance(GR)transgenic event,designated GG2,from the transgenic maize population through screening with high doses of glyphosate.A molecular analysis demonstrated that single copy of gat and gr79-epsps were integrated into the maize genome,and these two genes were stably transcribed and translated.Field trials showed that the transgenic event GG2 could tolerate 9000 g acid equivalent(a.e.)glyphosate per ha with no effect on phenotype or yield.A gas chromatography-mass spectrometry(GC–MS)analysis revealed that,shortly after glyphosate application,the glyphosate(PMG)and aminomethylphosphonic acid(AMPA)residues in GG2 leaves decreased by more than 90%compared to their levels in HGK60 transgenic plants,which only harbored the epsps gene.Additionally,PMG and its metabolic residues(AMPA and N-acetyl-PMG)were not detected in the silage or seeds of GG2,even when far more than the recommended agricultural dose of glyphosate was applied.The co-expression of gat and gr79-epsps,therefore,confers GG2 with high GR and a low risk of herbicide residue accumulation,making this germplasm a valuable GR event in herbicide-tolerant maize breeding.展开更多
In bone tissue engineering,scaffolds with excellent mechanical and bioactive properties play prominent roles in space maintaining and bone regeneration,attracting increasingly interests in clinical practice.In this st...In bone tissue engineering,scaffolds with excellent mechanical and bioactive properties play prominent roles in space maintaining and bone regeneration,attracting increasingly interests in clinical practice.In this study,strontium-incorporatedβ-tricalcium phosphate(β-TCP),named Sr-TCP,bioceramic triply periodic minimal surface(TPMS)structured scaffolds were successfully fabricated by digital light processing(DLP)-based 3D printing technique,achieving high porosity,enhanced strength,and excellent bioactivity.The Sr-TCP scaffolds were first characterized by element distribution,macrostructure and microstructure,and mechanical properties.Notably,the compressive strength of the scaffolds reached 1.44 MPa with porosity of 80%,bringing a great mechanical breakthrough to porous scaffolds.Furthermore,the Sr-TCP scaffolds also facilitated osteogenic differentiation of mouse osteoblastic cell line(MC3T3-E1)cells in both gene and protein aspects,verified by alkaline phosphatase(ALP)activity and polymerase chain reaction(PCR)assays.Overall,the 3D-printed Sr-TCP bioceramic TPMS structured scaffolds obtained high porosity,boosted strength,and superior bioactivity at the same time,serving as a promising approach for bone regeneration.展开更多
Introduction:In the early stages of the coronavirus disease 2019(COVID-19)epidemic in China,the highest level of public health emergency response(Level 1 Response)was launched in all province-level administrative divi...Introduction:In the early stages of the coronavirus disease 2019(COVID-19)epidemic in China,the highest level of public health emergency response(Level 1 Response)was launched in all province-level administrative divisions(PLADs)across the country.Provision of vaccination services was selectively suspended due to the physical distancing and gathering restrictions required of Level 1 Response.The purpose of this paper is to evaluate the impact of COVID-19 on vaccination services and the effectiveness of selective vaccination service suspension and catch-up vaccinations in China.Methods:Vaccine doses administered,routine vaccination coverage levels,catch-up vaccine doses administered,and coverage levels after the catch-up campaign were determined from individual vaccination records in sampled clinics,standard routine immunization administrative coverage reports,and catch-up vaccination activity reports submitted by PLADs between October 2019 and October 2020.Results:National Immunization Program(NIP)and non-NIP vaccine doses administered in sampled clinics decreased by 80% and 90%,respectively,compared with doses administered before the COVID-19 pandemic.Coverage with the birth dose of hepatitis B vaccine(HepB1)and the Bacillus Calmette-Guérin vaccine(BCG)—two vaccinations recommended to continue throughout the epidemic due to their timecritical nature—were maintained at over 85%,while coverage of other NIP vaccines decreased to below 60%by February 2020.Catch-up vaccination coverage of the 29 PLADs,excluding Xinjiang and Xizang(Tibet),began in April 2020 and exceeded 90%;Hubei catch-up coverage was 95% by October 2020.Conclusions and Implications for Public Health Practice:The COVID-19 pandemic had a great impact on China’s vaccination services.During the epidemic and time of local transmission of the coronavirus,HepB1,BCG,rabies vaccine for postexposure prophylaxis,and tetanus antitoxin(TAT)for wound prophylaxis were maintained at high levels.Of the 69 million vaccine doses postponed during the time of local transmission of the coronavirus,94% were administered in the catch-up campaign.China’s pandemic immunization practices may provide evidence for other countries’immunization programs.展开更多
A novel Mg-1.5Zn-0.6Zr-0.2Sc （denoted as ZK21-0.2Sc） alloy was developed as potential biodegrad- able implant materials. The microstructure, mechanical properties, and in vitro degradation behavior of the as-cast ZK...A novel Mg-1.5Zn-0.6Zr-0.2Sc （denoted as ZK21-0.2Sc） alloy was developed as potential biodegrad- able implant materials. The microstructure, mechanical properties, and in vitro degradation behavior of the as-cast ZK21-0.2Sc alloy were investigated and compared with ZK21 alloy and pure Mg. The ZK21 -0.2Sc alloy showed a single-phase structure with fine equiaxed grains. The alloy exhibited a good balance between strength and ductility. Both immersion tests and electrochemical tests showed that the ZK21-0.2Sc alloy had the lowest degradation rate in Hank＇s solution. The excellent degradation behavior of ZK21-0.2Sc alloy could be explained by the single-phase and fine grain structure, the more effective protection corrosion film, and the beneficial alloying effects of Zn, Zr and Sc.展开更多
What is already known about this topic?After the type 2 strain of the live,attenuated poliovirus vaccine was withdrawn globally in 2016,any identification of a type 2 poliovirus is a Public Health Emergency of Interna...What is already known about this topic?After the type 2 strain of the live,attenuated poliovirus vaccine was withdrawn globally in 2016,any identification of a type 2 poliovirus is a Public Health Emergency of International Concern.A vaccinederived type 2 poliovirus(VDPV2)was identified in Sichuan,prompting an urgent,comprehensive investigation and response.What is added by this report?Type 2 monovalent,live,attenuated oral poliovirus vaccine(mOPV2)is being used to respond to the numerous VDPV2 outbreaks seen around the world.In contrast,the response in Sichuan used Sabin strain inactivated poliovirus(sIPV)to stop circulation of the VDPV2.In the 6 months following the vaccination response,there have been no VDPV2s detected in Sichuan,despite extensive search.What are the implications for public health practices?Further search for the VDPV2 must continue in order to determine whether transmission has been stopped.The ongoing investigation and response to the Sichuan VDPV2 is providing evidence to the Global Polio Eradication Initiative on managing VDPV2 outbreaks.展开更多
What is already known about this topic?China has historically had high measles incidence and many associated deaths.A comprehensive measles elimination plan during 2006-2012 substantially reduced measles incidence;how...What is already known about this topic?China has historically had high measles incidence and many associated deaths.A comprehensive measles elimination plan during 2006-2012 substantially reduced measles incidence;however,a resurgence occurred during 2013-2015.What is added by this report?In China,measles surveillance,outbreak response,research,and program evaluation were used to strengthen routine immunization and target immunization activities for eliminating measles.Measles incidence declined from 31 per million in 2015 to 2.8 in 2018;only one measles-associated death has been reported during 2018-June 2019.What are the implications for public health practice?The World Health Organization-recommended strategy to eliminate measles can be effective,including in large,densely populated countries like China.展开更多
In late December 2019,clinicians in Hubei Province noticed and reported to health authorities a cluster of cases of pneumonia of unknown etiology(PUE)that turned out to be the start of the coronavirus disease 2019(COV...In late December 2019,clinicians in Hubei Province noticed and reported to health authorities a cluster of cases of pneumonia of unknown etiology(PUE)that turned out to be the start of the coronavirus disease 2019(COVID-19)pandemic(1).By January 29,2020,all provincial-level administrative divisions(PLADs)across the country had launched their highest public health emergency responses(Level 1 responses)(2-3).展开更多
Introduction:Poliomyelitis is a highly contagious,seasonal viral disease caused by any of three poliovirus(PV)serotypes(types 1,2,or 3).Oral poliovirus vaccine(OPV)on rare occasions causes vaccineassociated paralytic ...Introduction:Poliomyelitis is a highly contagious,seasonal viral disease caused by any of three poliovirus(PV)serotypes(types 1,2,or 3).Oral poliovirus vaccine(OPV)on rare occasions causes vaccineassociated paralytic poliomyelitis(VAPP)in recipients of OPV and close contacts of recently vaccinated individuals.This study describes the epidemiology of VAPP when an all OPV schedule was used in the Expanded Program on Immunization(EPI).Methods:VAPP cases were identified using standardized diagnostic criteria from data reported by 8 provincial-level administrative divisions(PLADs)to the National Acute Flaccid Paralysis(AFP)Surveillance System in an 18-month period between October 2012 and March 2014.Results:During this period,28 VAPP cases were reported.Using the number of births as a denominator,the estimated incidence of VAPP was 2.47 cases per million births.Using the number of OPV doses administered through routine immunization,the VAPP incidence was 0.55 cases per million doses.Among vaccine-recipient VAPP cases,22(85%)were associated with the first dose of OPV;3 were associated with the second OPV dose.The relative risk of VAPP following the first dose compared with the second dose was 7.07.Conclusions and Implications for Public Health Practice:The per-dose and per-child incidences of VAPP were consistent with incidence estimates by the World Health Organization(WHO).The vast majority(85%)of VAPP in China was associated with the first dose of OPV in an all-OPV schedule.Because inactivated polio vaccine(IPV)is known to prevent VAPP from subsequent doses of OPV in immunocompetent children,this association provided strong evidence for using an IPV-first,sequential IPVOPV polio vaccination schedule in China during the globally-synchronized cessation of type 2 OPV and introduction of IPV in 2016.展开更多
Background:China has been polio-free since 2000 and maintains an acute flaccid paralysis(AFP)surveillance system.Residual paralysis(RP)in children with acute flaccid paralysis can be caused by Sabinstrain poliovirus(P...Background:China has been polio-free since 2000 and maintains an acute flaccid paralysis(AFP)surveillance system.Residual paralysis(RP)in children with acute flaccid paralysis can be caused by Sabinstrain poliovirus(PV)and non-polio enteroviruses(NPEV).Methods:The national AFP surveillance data was analyzed to describe AFP cases with RP in the mainland of China during 2001 to 2010.Epidemiological patterns and virus detection of AFP cases with RP were described.Results:Annual incidence of AFP with RP among children aged<15 years old ranged between 0.22-0.35 cases per 100,000.The peak age for AFP with RP and PV was 2 to 4 months.Among cases with viral Sabinstrain viral isolates,types Ⅱ and Ⅲ were the most common.A summer season peak in RP cases was similar to cases with NPEV isolated.Conclusions and Implications for Public Health Practice:The first ten years after polio eradication of AFP surveillance data for the occurrence of RP can serve as a baseline rate for poliovirus vaccine changes in the routine immunization system to help detect vaccine safety signals in a timely manner and to support the routine polio immunization program switch in China.展开更多
Introduction:All countries face the potential threat of imported polioviruses,including both wild type and circulating vaccine-derived polioviruses.In response,we conducted a province-level assessment in China to eval...Introduction:All countries face the potential threat of imported polioviruses,including both wild type and circulating vaccine-derived polioviruses.In response,we conducted a province-level assessment in China to evaluate the risk of importation and transmission of type 1 wild poliovirus(WPV1)and type 2 vaccine-derived poliovirus(VDPV2).Methods:Distinct risk assessment tools for WPV1 and VDPV2 were employed,incorporating three primary indicators—population immunity,poliovirus surveillance,and importation risk.WPV1 was assessed using 13 secondary indicators,whereas VDPV2 utilized 21 secondary indicators.Assessments used comprehensive provincial data from the preceding five years.Scores(S-values)were derived from the secondary indicators’criteria and ratings,and used to classify the provincial-level administrative divisions(PLADs)into three risk categories:high,medium,and low.The top 10%of PLADs were designated as highrisk,with the remaining provinces equally distributed into medium-and low-risk categories.Results:In 2023,Xizang,Qinghai,and Xinjiang PLADs faced the highest risk of WPV1 importation and transmission;Xizang,Shaanxi,and Hainan PLADs were at the greatest risk for VDPV2 importation and transmission.Conclusions:Risk assessment for VDPV2 importation and transmission has identified a distinct set of high-risk provinces compared to those identified by WPV1 risk assessment.Preventive and proactive response measures tailored to the specific risks should be implemented to maintain China’s polio-free status.展开更多
基金Supported by the public health emergency response mechanism operated by the Chinese Center for Disease Control and Prevention(No.102393220020010000017).
文摘Introduction:Detecting poliovirus infections proves to be highly challenging due to their asymptomatic nature and infectious potential,highlighting the crucial importance of effective detection methods in the context of polio eradication efforts.In many countries,including China,the primary approach for identifying polio outbreaks has been through acute flaccid paralysis(AFP)surveillance.In this study,we conducted an evaluation spanning three decades(1993–2022)to assess the effectiveness of AFP surveillance in China.Methods:Data on all AFP cases identified since 1993 and national-level AFP surveillance system quality indicators aligned with the World Health Organization(WHO)standards were collected for analysis.The quality indicators assess surveillance sensitivity,completeness,timeliness of detection notification,case investigation,and laboratory workup.Surveillance sensitivity is determined by the non-polio AFP(NPAFP)detection rate among children under 15 years of age.Results:Between 1993 and 2022,a total of 150,779 AFP cases were identified and reported.Within this pool,surveillance identified 95 cases of wild poliovirus(WPV)and 24 cases due to vaccinederived poliovirus.From 1995 onwards,the detection rate of NPAFP cases consistently adhered to the WHO and national standards of≥1 case per 100,000,falling between 1.38 and 2.76.Starting in 1997,all timeliness indicators consistently achieved the criteria of 80%,apart from the consistency in meeting standards set for the rate of positive specimens sent to the national laboratory.Conclusions:AFP surveillance has been instrumental in China’s accomplishment of maintaining a polio-free status.The ongoing adherence to key performance indicators,ensuring sensitivity and prompt specimen collection,demonstrates that AFP surveillance is proficient in detecting poliovirus in China.As we move into the post-eradication phase,AFP surveillance remains crucial for the sustained absence of polioviruses in the long term.
基金Supported by the operation of the public health emergency response mechanism of the Chinese Center for Disease Control and Prevention(102393220020010000017).
文摘Introduction:In recent years,the incidence of measles in China has consistently remained below 1 per 100,000 population,yet the disease has not been eliminated.This study aims to comprehensively analyze the epidemiological characteristics of measles from 2005 to 2022,identify high-risk populations and areas,and propose targeted interventions.Methods:We utilized data from the China Disease Prevention and Control Information System for our comprehensive analysis.Spatial autocorrelation was employed to examine the spatial clustering of measles,while spatiotemporal scanning analysis was used to detect spatiotemporal clustering to describe measles epidemiology during the study period.Results:Between 2005 and 2022,732,218 measles cases were reported in China.Overall,the incidence of measles exhibited a downward trend,particularly during the periods of 2008-2011 and 2015-2022.In 2022,the incidence rate reached its historical low at 0.039 per 100,000 population.Measles predominantly affects young children.Since 2017,global spatial clustering has diminished,although hotspot areas persist in the western provinces.Spatial-temporal scanning identified a high-incidence cluster from 2005 to 2008,comprising 15 provinces in the western,central,and northern regions of China.Conversely,from 2016 to 2022,a low-incidence cluster was detected in the southern and central provinces.Conclusions:China has made significant progress in measles prevention and control.The recent low incidence and absence of substantial spatiotemporal clustering indicate that China is nearing measles elimination.However,there is a continuing need to enhance prevention and control efforts among very young children and in historic incidence hotspots in western provinces.Additionally,improving the diagnosis of vaccine-associated rash illnesses is essential.
基金Supported by Operation of the CDC Public Health Emergency Response Mechanism in China(131031001000150001).
文摘What is already known about this topic?The incidences of vaccine-preventable diseases(VPDs)included in the Expanded Program on Immunization in China have decreased significantly in recent decades.What is added by this report?This study summarizes the national incidences of nine VPDs and the seroprevalence of hepatitis B surface antigen(HBsAg)under different immunization strategies from 1950 through 2021 in China.The sharpest decreases in VPD incidence and under-5-year HBsAg seroprevalence occurred during the latest stage of the National Immunization Program.The decreases in VPD incidence were most prominent among children under five years of age.What are the implications for public health practice?These findings provide valuable insights for vaccine value assessment and emphasize the importance of implementing immunization strategies in targeted populations.
基金This work was supported by the Instrument Developing Project of the Chinese Academy of Sciences(CAS)(No.GJJSTD2020007)。
文摘We present a high-energy,hundred-picosecond(ps)pulsed mid-ultraviolet solid-state laser at 266 nm by a direct second harmonic generation(SHG)in a barium borate(BaB_(2)O_(4),BBO)nonlinear crystal.The green pump source is a 710 mJ,330 ps pulsed laser at a wavelength of 532 nm with a repetition rate of 1 Hz.Under a green pump energy of 710 mJ,a maximum output energy of 253.3 mJ at 266 nm is achieved with 250 ps pulse duration resulting in a peak power of more than 1 GW,corresponding to an SHG conversion efficiency of 35.7%from 532 to 266 nm.The experimental data were well consistent with the theoretical prediction.To the best of our knowledge,this laser exhibits both the highest output energy and highest peak power ever achieved in a hundred-ps/ps regime at 266 nm for BBO-SHG.
基金supported by the National Transgenic Major Program of China(2016ZX08003001),。
文摘Herbicide tolerance has been the dominant trait introduced during the global commercialization of genetically modified(GM)crops.Herbicide-tolerant crops,especially glyphosate-resistant crops,offer great advantages for weed management;however,despite these benefits,glyphosate-resistant maize(Zea mays L.)has not yet been commercially deployed in China.To develop a new bio-breeding resource for glyphosate-resistant maize,we introduced a codon-optimized glyphosate N-acetyltransferase gene,gat,and the enolpyruvyl-shikimate-3-phosphate synthase gene,gr79-epsps,into the maize variety B104.We selected a genetically stable high glyphosate resistance(GR)transgenic event,designated GG2,from the transgenic maize population through screening with high doses of glyphosate.A molecular analysis demonstrated that single copy of gat and gr79-epsps were integrated into the maize genome,and these two genes were stably transcribed and translated.Field trials showed that the transgenic event GG2 could tolerate 9000 g acid equivalent(a.e.)glyphosate per ha with no effect on phenotype or yield.A gas chromatography-mass spectrometry(GC–MS)analysis revealed that,shortly after glyphosate application,the glyphosate(PMG)and aminomethylphosphonic acid(AMPA)residues in GG2 leaves decreased by more than 90%compared to their levels in HGK60 transgenic plants,which only harbored the epsps gene.Additionally,PMG and its metabolic residues(AMPA and N-acetyl-PMG)were not detected in the silage or seeds of GG2,even when far more than the recommended agricultural dose of glyphosate was applied.The co-expression of gat and gr79-epsps,therefore,confers GG2 with high GR and a low risk of herbicide residue accumulation,making this germplasm a valuable GR event in herbicide-tolerant maize breeding.
基金supported by the National Natural Science Foundation of China(Nos.51972339 and 51802350).
文摘In bone tissue engineering,scaffolds with excellent mechanical and bioactive properties play prominent roles in space maintaining and bone regeneration,attracting increasingly interests in clinical practice.In this study,strontium-incorporatedβ-tricalcium phosphate(β-TCP),named Sr-TCP,bioceramic triply periodic minimal surface(TPMS)structured scaffolds were successfully fabricated by digital light processing(DLP)-based 3D printing technique,achieving high porosity,enhanced strength,and excellent bioactivity.The Sr-TCP scaffolds were first characterized by element distribution,macrostructure and microstructure,and mechanical properties.Notably,the compressive strength of the scaffolds reached 1.44 MPa with porosity of 80%,bringing a great mechanical breakthrough to porous scaffolds.Furthermore,the Sr-TCP scaffolds also facilitated osteogenic differentiation of mouse osteoblastic cell line(MC3T3-E1)cells in both gene and protein aspects,verified by alkaline phosphatase(ALP)activity and polymerase chain reaction(PCR)assays.Overall,the 3D-printed Sr-TCP bioceramic TPMS structured scaffolds obtained high porosity,boosted strength,and superior bioactivity at the same time,serving as a promising approach for bone regeneration.
基金funded by grants from the Vaccine Preventable Diseases and Immunization(VDI)of World Health Organization Office in China(No.2020/1017283-0).
文摘Introduction:In the early stages of the coronavirus disease 2019(COVID-19)epidemic in China,the highest level of public health emergency response(Level 1 Response)was launched in all province-level administrative divisions(PLADs)across the country.Provision of vaccination services was selectively suspended due to the physical distancing and gathering restrictions required of Level 1 Response.The purpose of this paper is to evaluate the impact of COVID-19 on vaccination services and the effectiveness of selective vaccination service suspension and catch-up vaccinations in China.Methods:Vaccine doses administered,routine vaccination coverage levels,catch-up vaccine doses administered,and coverage levels after the catch-up campaign were determined from individual vaccination records in sampled clinics,standard routine immunization administrative coverage reports,and catch-up vaccination activity reports submitted by PLADs between October 2019 and October 2020.Results:National Immunization Program(NIP)and non-NIP vaccine doses administered in sampled clinics decreased by 80% and 90%,respectively,compared with doses administered before the COVID-19 pandemic.Coverage with the birth dose of hepatitis B vaccine(HepB1)and the Bacillus Calmette-Guérin vaccine(BCG)—two vaccinations recommended to continue throughout the epidemic due to their timecritical nature—were maintained at over 85%,while coverage of other NIP vaccines decreased to below 60%by February 2020.Catch-up vaccination coverage of the 29 PLADs,excluding Xinjiang and Xizang(Tibet),began in April 2020 and exceeded 90%;Hubei catch-up coverage was 95% by October 2020.Conclusions and Implications for Public Health Practice:The COVID-19 pandemic had a great impact on China’s vaccination services.During the epidemic and time of local transmission of the coronavirus,HepB1,BCG,rabies vaccine for postexposure prophylaxis,and tetanus antitoxin(TAT)for wound prophylaxis were maintained at high levels.Of the 69 million vaccine doses postponed during the time of local transmission of the coronavirus,94% were administered in the catch-up campaign.China’s pandemic immunization practices may provide evidence for other countries’immunization programs.
基金financially supported by the National Natural Science Foundation of China(No.51174025)Specialized Research Fund for the Doctoral Program of Higher Education of China(No.20110006130004)
文摘A novel Mg-1.5Zn-0.6Zr-0.2Sc （denoted as ZK21-0.2Sc） alloy was developed as potential biodegrad- able implant materials. The microstructure, mechanical properties, and in vitro degradation behavior of the as-cast ZK21-0.2Sc alloy were investigated and compared with ZK21 alloy and pure Mg. The ZK21 -0.2Sc alloy showed a single-phase structure with fine equiaxed grains. The alloy exhibited a good balance between strength and ductility. Both immersion tests and electrochemical tests showed that the ZK21-0.2Sc alloy had the lowest degradation rate in Hank＇s solution. The excellent degradation behavior of ZK21-0.2Sc alloy could be explained by the single-phase and fine grain structure, the more effective protection corrosion film, and the beneficial alloying effects of Zn, Zr and Sc.
基金supported by National Science and Technology Major Project of China(2018ZX10101002-003).
文摘What is already known about this topic?After the type 2 strain of the live,attenuated poliovirus vaccine was withdrawn globally in 2016,any identification of a type 2 poliovirus is a Public Health Emergency of International Concern.A vaccinederived type 2 poliovirus(VDPV2)was identified in Sichuan,prompting an urgent,comprehensive investigation and response.What is added by this report?Type 2 monovalent,live,attenuated oral poliovirus vaccine(mOPV2)is being used to respond to the numerous VDPV2 outbreaks seen around the world.In contrast,the response in Sichuan used Sabin strain inactivated poliovirus(sIPV)to stop circulation of the VDPV2.In the 6 months following the vaccination response,there have been no VDPV2s detected in Sichuan,despite extensive search.What are the implications for public health practices?Further search for the VDPV2 must continue in order to determine whether transmission has been stopped.The ongoing investigation and response to the Sichuan VDPV2 is providing evidence to the Global Polio Eradication Initiative on managing VDPV2 outbreaks.
文摘What is already known about this topic?China has historically had high measles incidence and many associated deaths.A comprehensive measles elimination plan during 2006-2012 substantially reduced measles incidence;however,a resurgence occurred during 2013-2015.What is added by this report?In China,measles surveillance,outbreak response,research,and program evaluation were used to strengthen routine immunization and target immunization activities for eliminating measles.Measles incidence declined from 31 per million in 2015 to 2.8 in 2018;only one measles-associated death has been reported during 2018-June 2019.What are the implications for public health practice?The World Health Organization-recommended strategy to eliminate measles can be effective,including in large,densely populated countries like China.
文摘In late December 2019,clinicians in Hubei Province noticed and reported to health authorities a cluster of cases of pneumonia of unknown etiology(PUE)that turned out to be the start of the coronavirus disease 2019(COVID-19)pandemic(1).By January 29,2020,all provincial-level administrative divisions(PLADs)across the country had launched their highest public health emergency responses(Level 1 responses)(2-3).
文摘Introduction:Poliomyelitis is a highly contagious,seasonal viral disease caused by any of three poliovirus(PV)serotypes(types 1,2,or 3).Oral poliovirus vaccine(OPV)on rare occasions causes vaccineassociated paralytic poliomyelitis(VAPP)in recipients of OPV and close contacts of recently vaccinated individuals.This study describes the epidemiology of VAPP when an all OPV schedule was used in the Expanded Program on Immunization(EPI).Methods:VAPP cases were identified using standardized diagnostic criteria from data reported by 8 provincial-level administrative divisions(PLADs)to the National Acute Flaccid Paralysis(AFP)Surveillance System in an 18-month period between October 2012 and March 2014.Results:During this period,28 VAPP cases were reported.Using the number of births as a denominator,the estimated incidence of VAPP was 2.47 cases per million births.Using the number of OPV doses administered through routine immunization,the VAPP incidence was 0.55 cases per million doses.Among vaccine-recipient VAPP cases,22(85%)were associated with the first dose of OPV;3 were associated with the second OPV dose.The relative risk of VAPP following the first dose compared with the second dose was 7.07.Conclusions and Implications for Public Health Practice:The per-dose and per-child incidences of VAPP were consistent with incidence estimates by the World Health Organization(WHO).The vast majority(85%)of VAPP in China was associated with the first dose of OPV in an all-OPV schedule.Because inactivated polio vaccine(IPV)is known to prevent VAPP from subsequent doses of OPV in immunocompetent children,this association provided strong evidence for using an IPV-first,sequential IPVOPV polio vaccination schedule in China during the globally-synchronized cessation of type 2 OPV and introduction of IPV in 2016.
文摘Background:China has been polio-free since 2000 and maintains an acute flaccid paralysis(AFP)surveillance system.Residual paralysis(RP)in children with acute flaccid paralysis can be caused by Sabinstrain poliovirus(PV)and non-polio enteroviruses(NPEV).Methods:The national AFP surveillance data was analyzed to describe AFP cases with RP in the mainland of China during 2001 to 2010.Epidemiological patterns and virus detection of AFP cases with RP were described.Results:Annual incidence of AFP with RP among children aged<15 years old ranged between 0.22-0.35 cases per 100,000.The peak age for AFP with RP and PV was 2 to 4 months.Among cases with viral Sabinstrain viral isolates,types Ⅱ and Ⅲ were the most common.A summer season peak in RP cases was similar to cases with NPEV isolated.Conclusions and Implications for Public Health Practice:The first ten years after polio eradication of AFP surveillance data for the occurrence of RP can serve as a baseline rate for poliovirus vaccine changes in the routine immunization system to help detect vaccine safety signals in a timely manner and to support the routine polio immunization program switch in China.
基金Supported by the Evaluation of 2 Polio Vaccine Strategy Switches in China(JY22-3-10).
文摘Introduction:All countries face the potential threat of imported polioviruses,including both wild type and circulating vaccine-derived polioviruses.In response,we conducted a province-level assessment in China to evaluate the risk of importation and transmission of type 1 wild poliovirus(WPV1)and type 2 vaccine-derived poliovirus(VDPV2).Methods:Distinct risk assessment tools for WPV1 and VDPV2 were employed,incorporating three primary indicators—population immunity,poliovirus surveillance,and importation risk.WPV1 was assessed using 13 secondary indicators,whereas VDPV2 utilized 21 secondary indicators.Assessments used comprehensive provincial data from the preceding five years.Scores(S-values)were derived from the secondary indicators’criteria and ratings,and used to classify the provincial-level administrative divisions(PLADs)into three risk categories:high,medium,and low.The top 10%of PLADs were designated as highrisk,with the remaining provinces equally distributed into medium-and low-risk categories.Results:In 2023,Xizang,Qinghai,and Xinjiang PLADs faced the highest risk of WPV1 importation and transmission;Xizang,Shaanxi,and Hainan PLADs were at the greatest risk for VDPV2 importation and transmission.Conclusions:Risk assessment for VDPV2 importation and transmission has identified a distinct set of high-risk provinces compared to those identified by WPV1 risk assessment.Preventive and proactive response measures tailored to the specific risks should be implemented to maintain China’s polio-free status.
