The basic reproduction number of an infectious agent is the average number of infections one case can generate over the course of the infectious period,in a naïve,uninfected population.It is well-known that the e...The basic reproduction number of an infectious agent is the average number of infections one case can generate over the course of the infectious period,in a naïve,uninfected population.It is well-known that the estimation of this number may vary due to several methodological issues,including different assumptions and choice of parameters,utilized models,used datasets and estimation period.With the spreading of the novel coronavirus(2019-nCoV)infection,the reproduction number has been found to vary,reflecting the dynamics of transmission of the coronavirus outbreak as well as the case reporting rate.Due to significant variations in the control strategies,which have been changing over time,and thanks to the introduction of detection technologies that have been rapidly improved,enabling to shorten the time from infection/symptoms onset to diagnosis,leading to faster confirmation of the new coronavirus cases,our previous estimations on the transmission risk of the 2019-nCoV need to be revised.By using time-dependent contact and diagnose rates,we refit our previously proposed dynamics transmission model to the data available until January 29th,2020 and re-estimated the effective daily reproduction ratio that better quantifies the evolution of the interventions.We estimated when the effective daily reproduction ratio has fallen below 1 and when the epidemics will peak.Our updated findings suggest that the best measure is persistent and strict self-isolation.The epidemics will continue to grow,and can peak soon with the peak time depending highly on the public health interventions practically implemented.展开更多
Pneumoconiosis refers to a spectrum of pulmonary diseases caused by inhalation of mineral dust,usually as the result of certain occupations.The main pathological features include chronic pulmonary inflammation and pro...Pneumoconiosis refers to a spectrum of pulmonary diseases caused by inhalation of mineral dust,usually as the result of certain occupations.The main pathological features include chronic pulmonary inflammation and progressive pulmonary fibrosis,which can eventually lead to death caused by respiratory and/or heart failure.Pneumoconiosis is widespread globally,seriously threatening global public health.Its high incidence and mortality lie in improper occupational protection,and in the lack of early diagnostic methods and effective treatments.This article reviews the epidemiology,safeguard procedures,diagnosis,and treatment of pneumoconiosis,and summarizes recent research advances and future research prospects.展开更多
Severe fever with thrombocytopenia syndrome(SFTS) is an emerging hemorrhagic fever in rural areas of China and is caused by a new bunyavirus,SFTSV,named after the disease.The transmission vectors and animal hosts of S...Severe fever with thrombocytopenia syndrome(SFTS) is an emerging hemorrhagic fever in rural areas of China and is caused by a new bunyavirus,SFTSV,named after the disease.The transmission vectors and animal hosts of SFTSV are unclear.Ticks are the most likely transmission vectors and domestic animals,including goats,dogs,and cattle,are potential amplifying hosts of SFTSV.The clinical symptoms of SFTS are nonspecific,but major symptoms include fever,gastrointestinal symptoms,myalgia,dizziness,joint pain,chills,and regional lymphadenopathy.The most common abnormalities in laboratory test results are thrombocytopenia(95%),leukocytopenia(86%),and elevated levels of serum alanine aminotransferase,aspartate aminotransferase,creatine kinase,and lactate dehydrogenase.The fatality rate for SFTS is 12% on average,and the annual incidence of the disease is approximately five per 100000 of the rural population.展开更多
For the past several decades, the infectious disease profile in China has been shifting with rapid developments in social and economic aspects, environment, quality of food, water, housing, and public health infrastru...For the past several decades, the infectious disease profile in China has been shifting with rapid developments in social and economic aspects, environment, quality of food, water, housing, and public health infrastructure. Notably, 5 notifiable infectious diseases have been almost eradicated, and the incidence of 18 additional notifiable infectious diseases has been significantly reduced. Unexpectedly, the incidence of over 10 notifiable infectious diseases, including HIV, brucellosis, syphilis, and dengue fever, has been increasing. Nevertheless, frequent infectious disease outbreaks/events have been reported almost every year, and imported infectious diseases have increased since 2015. New pathogens and over 100 new genotypes or serotypes of known pathogens have been identified. Some infectious diseases seem to be exacerbated by various factors, including rapid urbanization, large numbers of migrant workers, changes in climate, ecology, and policies, such as returning farmland to forests. This review summarizes the current experiences and lessons from China in managing emerging and re-emerging infectious diseases, especially the effects of ecology, climate, and behavior, which should have merits in helping other countries to control and prevent infectious diseases.展开更多
This review highlights recent progresses in seed germination and dormancy research.Research on the weakening of the endosperm during germination,which is almost a classic theme in seed biology,was resumed byα-xylosid...This review highlights recent progresses in seed germination and dormancy research.Research on the weakening of the endosperm during germination,which is almost a classic theme in seed biology,was resumed byα-xylosidase studies.Strong genetic evidence was presented to suggest that the quality control of xyloglucan biosynthesis in the endosperm(and the embryo)plays a critical role in germination.Further analyses on the endosperm and the adjace nt layers have suggested that the cutin coat in the endosperm-testa interphase negatively affects germination while the en dosperm-embryo in terphase produces a sheath that facilitates germination.These progresses significantly advanced our understanding of seed germination mechanisms.A breakthrough in dormancy research,on the other hand,revealed the unique abscisic acid signaling pathway that is regulated by DELAY OF GERMINATION1(DOG1).The detailed analysis of DOC1 expression uncovered the intriguing story of reciprocal regulation of the sensean tisense pair,which gen erated new questions.Recent studies also suggested that the DOG1 function is not limited to dormancy but extended through general seed maturation,which provokes questions about the evolution of DOG1 family proteins.Seed biology is becoming more exciting with the classic stories being revitalized and new puzzles emerging from the frontier.展开更多
There is growing concern in Sub-Saharan Africa about the spread of the Ebola virus disease(EVD),formerly known as Ebola haemorrhagic fever,and the public health burden that it ensues.Since 1976,there have been 885,343...There is growing concern in Sub-Saharan Africa about the spread of the Ebola virus disease(EVD),formerly known as Ebola haemorrhagic fever,and the public health burden that it ensues.Since 1976,there have been 885,343 suspected and laboratory confirmed cases of EVD and the disease has claimed 2,512 cases and 932 fatality in West Africa.There are certain requirements that must be met when responding to EVD outbreaks and this process could incur certain challenges.For the purposes of this paper,five have been identified:(i)the deficiency in the development and implementation of surveillance response systems against Ebola and others infectious disease outbreaks in Africa;(ii)the lack of education and knowledge resulting in an EVD outbreak triggering panic,anxiety,psychosocial trauma,isolation and dignity impounding,stigmatisation,community ostracism and resistance to associated socio-ecological and public health consequences;(iii)limited financial resources,human technical capacity and weak community and national health system operational plans for prevention and control responses,practices and management;(iv)inadequate leadership and coordination;and(v)the lack of development of new strategies,tools and approaches,such as improved diagnostics and novel therapies including vaccines which can assist in preventing,controlling and containing Ebola outbreaks as well as the spread of the disease.Hence,there is an urgent need to develop and implement an active early warning alert and surveillance response system for outbreak response and control of emerging infectious diseases.Understanding the unending risks of transmission dynamics and resurgence is essential in implementing rapid effective response interventions tailored to specific local settings and contexts.Therefore,the following actions are recommended:(i)national and regional inter-sectorial and trans-disciplinary surveillance response systems that include early warnings,as well as critical human resources development,must be quickly adopted by allied ministries 展开更多
Like RNA viruses in general,coronaviruses(CoV)exhibit high mutation rates which,in combination with their strong tendency to recombine,enable them to overcome the host species barrier and adapt to new hosts.It is curr...Like RNA viruses in general,coronaviruses(CoV)exhibit high mutation rates which,in combination with their strong tendency to recombine,enable them to overcome the host species barrier and adapt to new hosts.It is currently known that six CoV are able to infect pigs.Four of them belong to the genus Alphacoronavirus[transmissible gastroenteritis coronavirus(TEGV),porcine respiratory coronavirus(PRCV),porcine epidemic diarrhea virus(PEDV),swine acute diarrhea syndrome coronavirus(SADS-CoV)],one of them to the genus Betacoronavirus[porcine hemagglutinating encephalomyelitis virus(PHEV)]and the last one to the genus Deltacoronavirus(PDCoV).PHEV was one of the first identified swine CoV and is still widespread,causing subclinical infections in pigs in several countries.PRCV,a spike deletion mutant of TGEV associated with respiratory tract infection,appeared in the 1980 s.PRCV is considered nonpathogenic since its infection course is mild or subclinical.Since its appearance,pig populations have become immune to both PRCV and TGEV,leading to a significant reduction in the clinical and economic importance of TGEV.TGEV,PEDV and PDCoV are enteropathogenic CoV and cause clinically indistinguishable acute gastroenteritis in all age groups of pigs.PDCoV and SADS-CoV have emerged in 2014(US)and in 2017(China),respectively.Rapid diagnosis is crucial for controlling CoV infections and preventing them from spreading.Since vaccines are available only for some porcine CoV,prevention should focus mainly on a high level of biosecurity.In view of the diversity of CoV and the potential risk factors associated with zoonotic emergence,updating the knowledge concerning this area is essential.展开更多
Enzymes are biological catalysts that can convert substrates into products in biochemical reactions.In 1926,the first enzyme,urease,was determined to be a protein by James B.Sumner who won the Nobel Prize in 1946.Sinc...Enzymes are biological catalysts that can convert substrates into products in biochemical reactions.In 1926,the first enzyme,urease,was determined to be a protein by James B.Sumner who won the Nobel Prize in 1946.Since then,enzymes have been considered to be proteins,which allows them to achieve their high catalytic activity with high specific activity under mild conditions.However,in general,the enzyme activity of proteins is lost after exposure to extremes of p H and high temperature,and proteins are also susceptible to digestion by proteases in the environment,which dramatically hinders their practical applications in展开更多
基金This research was funded by the National Natural Science Foundation of China(grant numbers:11631012(YX,ST),61772017(ST))by the Canada Research Chair Program(grant number:230720(JW)the Natural Sciences and Engineering Research Council of Canada(Grant number:105588-2011(JW).
文摘The basic reproduction number of an infectious agent is the average number of infections one case can generate over the course of the infectious period,in a naïve,uninfected population.It is well-known that the estimation of this number may vary due to several methodological issues,including different assumptions and choice of parameters,utilized models,used datasets and estimation period.With the spreading of the novel coronavirus(2019-nCoV)infection,the reproduction number has been found to vary,reflecting the dynamics of transmission of the coronavirus outbreak as well as the case reporting rate.Due to significant variations in the control strategies,which have been changing over time,and thanks to the introduction of detection technologies that have been rapidly improved,enabling to shorten the time from infection/symptoms onset to diagnosis,leading to faster confirmation of the new coronavirus cases,our previous estimations on the transmission risk of the 2019-nCoV need to be revised.By using time-dependent contact and diagnose rates,we refit our previously proposed dynamics transmission model to the data available until January 29th,2020 and re-estimated the effective daily reproduction ratio that better quantifies the evolution of the interventions.We estimated when the effective daily reproduction ratio has fallen below 1 and when the epidemics will peak.Our updated findings suggest that the best measure is persistent and strict self-isolation.The epidemics will continue to grow,and can peak soon with the peak time depending highly on the public health interventions practically implemented.
基金the CAMS Innovation Fund for Medical Sciences(CIFMS)(No.2018-I2M-1-001)the Basic Scientific Research Business Expense Project of Chinese Academy of Medical Sciences(No.20180709).
文摘Pneumoconiosis refers to a spectrum of pulmonary diseases caused by inhalation of mineral dust,usually as the result of certain occupations.The main pathological features include chronic pulmonary inflammation and progressive pulmonary fibrosis,which can eventually lead to death caused by respiratory and/or heart failure.Pneumoconiosis is widespread globally,seriously threatening global public health.Its high incidence and mortality lie in improper occupational protection,and in the lack of early diagnostic methods and effective treatments.This article reviews the epidemiology,safeguard procedures,diagnosis,and treatment of pneumoconiosis,and summarizes recent research advances and future research prospects.
文摘Severe fever with thrombocytopenia syndrome(SFTS) is an emerging hemorrhagic fever in rural areas of China and is caused by a new bunyavirus,SFTSV,named after the disease.The transmission vectors and animal hosts of SFTSV are unclear.Ticks are the most likely transmission vectors and domestic animals,including goats,dogs,and cattle,are potential amplifying hosts of SFTSV.The clinical symptoms of SFTS are nonspecific,but major symptoms include fever,gastrointestinal symptoms,myalgia,dizziness,joint pain,chills,and regional lymphadenopathy.The most common abnormalities in laboratory test results are thrombocytopenia(95%),leukocytopenia(86%),and elevated levels of serum alanine aminotransferase,aspartate aminotransferase,creatine kinase,and lactate dehydrogenase.The fatality rate for SFTS is 12% on average,and the annual incidence of the disease is approximately five per 100000 of the rural population.
基金This work was supported by grants from the National Natural Science Foundation of China （Nos. L1522033, 81290340, and 81290345） and the National Key Research and Development Program of China （No. 2016YFC1201903）. We thank the two anonymous reviewers for the improvement of this study. We also extend our gratitude to Dr. Hualiang Lin and Prof. Xinhe Lai for the revision and discussion.
文摘For the past several decades, the infectious disease profile in China has been shifting with rapid developments in social and economic aspects, environment, quality of food, water, housing, and public health infrastructure. Notably, 5 notifiable infectious diseases have been almost eradicated, and the incidence of 18 additional notifiable infectious diseases has been significantly reduced. Unexpectedly, the incidence of over 10 notifiable infectious diseases, including HIV, brucellosis, syphilis, and dengue fever, has been increasing. Nevertheless, frequent infectious disease outbreaks/events have been reported almost every year, and imported infectious diseases have increased since 2015. New pathogens and over 100 new genotypes or serotypes of known pathogens have been identified. Some infectious diseases seem to be exacerbated by various factors, including rapid urbanization, large numbers of migrant workers, changes in climate, ecology, and policies, such as returning farmland to forests. This review summarizes the current experiences and lessons from China in managing emerging and re-emerging infectious diseases, especially the effects of ecology, climate, and behavior, which should have merits in helping other countries to control and prevent infectious diseases.
文摘This review highlights recent progresses in seed germination and dormancy research.Research on the weakening of the endosperm during germination,which is almost a classic theme in seed biology,was resumed byα-xylosidase studies.Strong genetic evidence was presented to suggest that the quality control of xyloglucan biosynthesis in the endosperm(and the embryo)plays a critical role in germination.Further analyses on the endosperm and the adjace nt layers have suggested that the cutin coat in the endosperm-testa interphase negatively affects germination while the en dosperm-embryo in terphase produces a sheath that facilitates germination.These progresses significantly advanced our understanding of seed germination mechanisms.A breakthrough in dormancy research,on the other hand,revealed the unique abscisic acid signaling pathway that is regulated by DELAY OF GERMINATION1(DOG1).The detailed analysis of DOC1 expression uncovered the intriguing story of reciprocal regulation of the sensean tisense pair,which gen erated new questions.Recent studies also suggested that the DOG1 function is not limited to dormancy but extended through general seed maturation,which provokes questions about the evolution of DOG1 family proteins.Seed biology is becoming more exciting with the classic stories being revitalized and new puzzles emerging from the frontier.
文摘There is growing concern in Sub-Saharan Africa about the spread of the Ebola virus disease(EVD),formerly known as Ebola haemorrhagic fever,and the public health burden that it ensues.Since 1976,there have been 885,343 suspected and laboratory confirmed cases of EVD and the disease has claimed 2,512 cases and 932 fatality in West Africa.There are certain requirements that must be met when responding to EVD outbreaks and this process could incur certain challenges.For the purposes of this paper,five have been identified:(i)the deficiency in the development and implementation of surveillance response systems against Ebola and others infectious disease outbreaks in Africa;(ii)the lack of education and knowledge resulting in an EVD outbreak triggering panic,anxiety,psychosocial trauma,isolation and dignity impounding,stigmatisation,community ostracism and resistance to associated socio-ecological and public health consequences;(iii)limited financial resources,human technical capacity and weak community and national health system operational plans for prevention and control responses,practices and management;(iv)inadequate leadership and coordination;and(v)the lack of development of new strategies,tools and approaches,such as improved diagnostics and novel therapies including vaccines which can assist in preventing,controlling and containing Ebola outbreaks as well as the spread of the disease.Hence,there is an urgent need to develop and implement an active early warning alert and surveillance response system for outbreak response and control of emerging infectious diseases.Understanding the unending risks of transmission dynamics and resurgence is essential in implementing rapid effective response interventions tailored to specific local settings and contexts.Therefore,the following actions are recommended:(i)national and regional inter-sectorial and trans-disciplinary surveillance response systems that include early warnings,as well as critical human resources development,must be quickly adopted by allied ministries
基金supported by the National Science Centre,Poland,under research project(DEC-2014/13/B/NZ6/02566)statutory funding 506.514.05.00 of the Department of Preclinical Sciences and Infectious Diseases,Faculty of Veterinary Medicine and Animal Science,Poznan University of Life Sciences,Poznan,Poland。
文摘Like RNA viruses in general,coronaviruses(CoV)exhibit high mutation rates which,in combination with their strong tendency to recombine,enable them to overcome the host species barrier and adapt to new hosts.It is currently known that six CoV are able to infect pigs.Four of them belong to the genus Alphacoronavirus[transmissible gastroenteritis coronavirus(TEGV),porcine respiratory coronavirus(PRCV),porcine epidemic diarrhea virus(PEDV),swine acute diarrhea syndrome coronavirus(SADS-CoV)],one of them to the genus Betacoronavirus[porcine hemagglutinating encephalomyelitis virus(PHEV)]and the last one to the genus Deltacoronavirus(PDCoV).PHEV was one of the first identified swine CoV and is still widespread,causing subclinical infections in pigs in several countries.PRCV,a spike deletion mutant of TGEV associated with respiratory tract infection,appeared in the 1980 s.PRCV is considered nonpathogenic since its infection course is mild or subclinical.Since its appearance,pig populations have become immune to both PRCV and TGEV,leading to a significant reduction in the clinical and economic importance of TGEV.TGEV,PEDV and PDCoV are enteropathogenic CoV and cause clinically indistinguishable acute gastroenteritis in all age groups of pigs.PDCoV and SADS-CoV have emerged in 2014(US)and in 2017(China),respectively.Rapid diagnosis is crucial for controlling CoV infections and preventing them from spreading.Since vaccines are available only for some porcine CoV,prevention should focus mainly on a high level of biosecurity.In view of the diversity of CoV and the potential risk factors associated with zoonotic emergence,updating the knowledge concerning this area is essential.
文摘Enzymes are biological catalysts that can convert substrates into products in biochemical reactions.In 1926,the first enzyme,urease,was determined to be a protein by James B.Sumner who won the Nobel Prize in 1946.Since then,enzymes have been considered to be proteins,which allows them to achieve their high catalytic activity with high specific activity under mild conditions.However,in general,the enzyme activity of proteins is lost after exposure to extremes of p H and high temperature,and proteins are also susceptible to digestion by proteases in the environment,which dramatically hinders their practical applications in
