Objective:Rheumatoid arthritis(RA)is a common autoimmune disease characterized by multiple joint lesions and systemic complications.Danggui Niantong decoction(DGNTT)has been clinically used for RA treatment;however,it...Objective:Rheumatoid arthritis(RA)is a common autoimmune disease characterized by multiple joint lesions and systemic complications.Danggui Niantong decoction(DGNTT)has been clinically used for RA treatment;however,its beneficial effect on cardiopulmonary complications has not been reported.Methods:Female tumor necrosis factor-transgenic(TNF-Tg)mice were used to evaluate the therapeutic effects of DGNTT on arthritis and cardiopulmonary complications.Methotrexate(MTX)served as a positive control.Histopathological assessment of the joint sections was performed using hematoxylin and eosin(HE),Alcian Blue/Orange G,and tartrate-resistant acid phosphatase staining.Bone mass was assessed by micro-computed tomography,inflammatory infiltrates in the heart and lungs were evaluated by HE staining,cardiopulmonary fibrotic injury was identified by Masson’s trichrome staining,and hypertrophy of mouse cardiomyocytes was measured by wheat germ agglutinin(WGA)staining.Results:DGNTT mitigated the inflammation of the ankle joint synovium,decreased the number of osteoclasts,and increased the area of cartilage and bone mass in TNF-Tg mice.In addition,DGNTT decreased the infiltration of inflammatory cells into the lung and heart tissues,accompanied by a reduction in cardiopulmonary fibrosis and myocardial cell hypertrophy in TNF-Tg mice.As a positive control drug,MTX attenuated the pathological changes in joints,but had no beneficial effect on cardiopulmonary inflammation and fibrosis in TNF-Tg mice.Conclusions:DGNTT improved joint lesions and alleviated cardiopulmonary complications in TNF-Tg mice.展开更多
Coronavirus disease 2019(COVID-19)has become a worldwide pandemic.Hospitalized patients of COVID-19 suffer from a high mortality rate,motivating the development of convenient and practical methods that allow clinician...Coronavirus disease 2019(COVID-19)has become a worldwide pandemic.Hospitalized patients of COVID-19 suffer from a high mortality rate,motivating the development of convenient and practical methods that allow clinicians to promptly identify high-risk patients.Here,we have developed a risk score using clinical data from 1479 inpatients admitted to Tongji Hospital,Wuhan,China(development cohort)and externally validated with data from two other centers:141 inpatients from Jinyintan Hospital,Wuhan,China(validation cohort 1)and 432 inpatients from The Third People’s Hospital of Shenzhen,Shenzhen,China(validation cohort 2).The risk score is based on three biomarkers that are readily available in routine blood samples and can easily be translated into a probability of death.The risk score can predict the mortality of individual patients more than 12 d in advance with more than 90%accuracy across all cohorts.Moreover,the Kaplan-Meier score shows that patients can be clearly differentiated upon admission as low,intermediate,or high risk,with an area under the curve(AUC)score of 0.9551.In summary,a simple risk score has been validated to predict death in patients infected with severe acute respiratory syndrome coronavirus 2(SARS-CoV-2);it has also been validated in independent cohorts.展开更多
In response to problems of poor sampling quality,low sensitivity,and high demand for medical personnel regarding the current severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)oropharyngeal(OP)swab sampling us...In response to problems of poor sampling quality,low sensitivity,and high demand for medical personnel regarding the current severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)oropharyngeal(OP)swab sampling used in China,we aimed to evaluate the diagnostic performance and acceptability of saliva-based nucleic acid amplification tests(NAATs)in China.The results showed that,using nasopharyngeal(NP)swab results as the gold standard,the overall sensitivities for saliva specimens and OP swabs were 93.3%and 85.0%,the specificities were 92.6%and 93.8%,respectively.The results of an acceptability survey showed that the scores for saliva,OP,and NP samples were 9.46±1.69,8.11±2.42,and 4.58±3.82 out of 10,respectively,with significant differences among the three groups(P<0.05).With higher sensitivity,comparable specificity,and strong public preference,saliva-based NAATs represent a convenient and effective method for detecting SARS-CoV-2 in future epidemics.展开更多
Summary What is already known about this topic?Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)continues to evolve,the clinical manifestations resulting from different SARS-CoV-2 variants may demonstrate si...Summary What is already known about this topic?Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)continues to evolve,the clinical manifestations resulting from different SARS-CoV-2 variants may demonstrate significant variation.What is added by this report?We conducted a comparative analysis of the clinical features associated with SARS-CoV-2 Omicron subvariants BF.7.14 and BA.5.2.48 infections.The results of our study indicate that there are no substantial differences in clinical manifestations,duration of illness,healthcare-seeking behaviors,or treatment between these two subvariants.What are the implications for public health practice?Timely identification of alterations in the clinical spectrum is crucial for researchers and healthcare practitioners in order to enhance their comprehension of clinical manifestations,as well as the progression of SARS-CoV-2.Furthermore,this information is beneficial for policymakers in the process of revising and implementing appropriate countermeasures.展开更多
Intermittent rub-impact, during which the contact between rotor and stator is characterized by a ‘‘bouncing" or intermittent type of behavior, is one of the most common rubbing forms in rotating machinery. When the...Intermittent rub-impact, during which the contact between rotor and stator is characterized by a ‘‘bouncing" or intermittent type of behavior, is one of the most common rubbing forms in rotating machinery. When the intermittent rub-impact occurs, the non-smooth constraint, which is the phenomenon that the system stiffness changes with respect to the state of contact and noncontact, will appear. The paper aims at discovering the possible effects of the non-smooth constraint on the flexible rotor's modal characteristics by theoretical and experimental methods. The qualitative description for non-smooth constraint is given for the intermittent rub-impact process, and the dynamic modeling for a rotor system with non-smooth constraint is carried out. Meanwhile, the analysis method is developed by Floquet theory and Hill's method to obtain the rotor's modal characteristics. The results reveal that the non-smooth constraint produced by the intermittent rubimpact will increase the modal frequencies and critical speeds of the rotor system significantly.Due to the time-varying features of the constraint stiffness, the modal frequencies for the intermittent rub-impact rotor present fluctuant changes with the increase of rotation speed, which is different from the general linear rotor system. The non-smooth constraint is possible to lead the rotor's instability, and the rotor's instable regions can be expanded significantly for the increase of average constraint stiffness, constraint amplitude and contact time ratio. Non-smooth constraint could also expand the resonance speed and resonance sideband of the rotor system, which sometimes results in amplitude jump phenomenon.展开更多
Fan blade off(FBO) from a running turbofan rotor will introduce sudden unbalance into the dynamical system,which will lead to the rub-impact,the asymmetry of rotor and a series of interesting dynamic behavior.The pa...Fan blade off(FBO) from a running turbofan rotor will introduce sudden unbalance into the dynamical system,which will lead to the rub-impact,the asymmetry of rotor and a series of interesting dynamic behavior.The paper first presents a theoretical study on the response excited by sudden unbalance.The results reveal that the reaction force of the bearing located near the fan could always reach a very high value which may lead to the crush of ball,journal sticking,high stress on the other components and some other failures to endanger the safety of engine in FBO event.Therefore,the dynamic influence of a safety design named ‘‘fusing" is investigated by mechanism analysis.Meantime,an explicit FBO model is established to simulate the FBO event,and evaluate the effectiveness and potential dynamic influence of fusing design.The results show that the fusing design could reduce the vibration amplitude of rotor,the reaction force on most bearings and loads on mounts,but the sudden change of support stiffness induced by fusing could produce an impact effect which will couple with the influence of sudden unbalance.Therefore,the implementation of the design should be considered carefully with optimized parameters in actual aero-engine.展开更多
Capture of a strong elevated ducting event,especially its maintenance and sudden change,is of great value to airborne radar to achieve its beyond-the-line-of-sight detection.However,the knowledge is not easily accessi...Capture of a strong elevated ducting event,especially its maintenance and sudden change,is of great value to airborne radar to achieve its beyond-the-line-of-sight detection.However,the knowledge is not easily accessible over the open ocean and hence very rare.During the Air–Sea Interaction Survey(ASIS)over the western North Pacific(WNP)in May 2016,a strong elevated ducting event with a long-life period and sudden change in its evolution was observed.Measurements from the ASIS,images from the Himawari-8 satellite,reanalysis data from the ECMWF,and Weather Research and Forecasting(WRF)model,were used to analyze the maintenance and sudden change of this strong ducting event,together with the model performance on simulating it.The results showed that the maintenance of strong elevated ducts,with their tops ranging from 750 to 1050 m and average strength of approximately 38 M units,was caused by a strong dry air mass capping over the wet marine atmospheric boundary layer(MABL),together with the subsidence inversion associated with high pressure.The WRF model performs well in simulating them.However,a sudden increase in duct height with a slight decrease of strength was recorded by the subsequent GPS radiosonde,which was finally contributed to the mechanical turbulent inversion and hydrolapse associated with the marine low-level jet(MLLJ).The height of the maximum horizontal wind speed(Umh)of the MLLJ corresponds well with the bottom of the trapping layer.However,these jet-relevant ducts are generally weak and it is difficult to accurately simulate them by using the mesoscale numerical model,since the wind-shear produced eddies are too small to be properly parameterized.展开更多
On January 15,2022,a 26 years old female(Case A)went to a sampling site for coronavirus disease 2019(COVID-19)testing due to excessive fatigue and fever for two days.This patient preliminarily tested positive for seve...On January 15,2022,a 26 years old female(Case A)went to a sampling site for coronavirus disease 2019(COVID-19)testing due to excessive fatigue and fever for two days.This patient preliminarily tested positive for severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)using a quantitative real-time reverse transcription polymerase chain reaction(qRT-PCR)method.展开更多
Omicron(B.1.1.529),the fifth variant of concern(VOC)of severe acute respiratory syndrome coronavirus 2(SARS‐CoV‐2),was firstly identified in November 2021 in South Africa.Omicron contains far more genome mutations t...Omicron(B.1.1.529),the fifth variant of concern(VOC)of severe acute respiratory syndrome coronavirus 2(SARS‐CoV‐2),was firstly identified in November 2021 in South Africa.Omicron contains far more genome mutations than any other VOCs ever found,raising significant concerns about its increased transmissibility and immune evasion.Here,we report the importation of the Omicron variant into Beijing,China,in December 2021.Full‐length genome sequences of five imported strains were obtained,with their genetic features characterized.Each strain contained 57 to 61 nucleotide substitutions,39 deletions,and 9 insertions in the genome.Thirty to thirty‐two amino acid changes were found in the spike proteins of the five strains.The phylogenetic tree constructed by the maximum likelihood method showed that all five imported genomes belonged to Omicron(BA.1)(alias of B.1.1.529.1),which is leading to the current surge of coronavirus disease 2019(COVID‐19)cases worldwide.The globally increased COVID‐19 cases driven by the Omicron variant pose a significant challenge to disease prevention and control in China.Continuous viral genetic surveillance and increased testing among international travellers are required to contain this highly contagious variant.展开更多
Summary What is already known about this topic?Inhalational anthrax,also known as pulmonary anthrax,is an infectious disease caused by Bacillus anthracis.The patients are usually infected by inhaling aerosolized B.ant...Summary What is already known about this topic?Inhalational anthrax,also known as pulmonary anthrax,is an infectious disease caused by Bacillus anthracis.The patients are usually infected by inhaling aerosolized B.anthracis spores from dead animals or animal products.Compared to cutaneous anthrax,inhalational anthrax is rare and deadly and few cases in China were reported.What is added by this report?This report covers all information of clinical features,laboratory testing,and epidemiological characteristics as well as exposure history of a recent primary inhalational anthrax patient who was seeking medical treatment in Beijing Municipality in August 2021.New laboratory techniques,including second-generation sequencing,polymerase chain reaction,and rapid test for serum antibody,played an important role in the process.What are the implications for public health practice?The information provided in this report,including the correct sample type,epidemiological investigation details,and application of the new diagnostic criteria of anthrax,could assist public health professionals in dealing with anthrax epidemics.展开更多
As a typhoon approaches the continent,the position where anthropogenic aerosols penetrate,the convection competition between the eyewall and peripheral rainbands,and the separate contributions of direct aerosol-radiat...As a typhoon approaches the continent,the position where anthropogenic aerosols penetrate,the convection competition between the eyewall and peripheral rainbands,and the separate contributions of direct aerosol-radiation interactions(ARI)and indirect aerosol-cloud interactions(ACI),yield uncertainties in the convection intensification area and hence the typhoon intensity.Typhoon Lupit(2009)was simulated using the Weather Research and Forecasting Model with Chemistry(WRF-Chem)to investigate and isolate the direct and indirect effects of aerosols on the intensity,convection,and precipitation of the typhoon.Three simulations(CTL,CLEAN,and CTLARIOFF)were designed,representing a polluted case(CTL,considering the ingestion of anthropogenic aerosols with ARI and ACI),a clean maritime case(CLEAN,mainly with sea salt aerosols),and a polluted case without aerosol radiative forcing(CTLARIOFF,as per CTL but without ARI).The results showed that anthropogenic aerosols could penetrate into both the peripheral rainbands and the eyewall when the typhoon was approaching the Asian continent.Owing to the representation of the real aerosol scenario,the simulated typhoon intensity weakened and was closer to observed values in the CTL experiment.The ARI dominated over ACI with the opposite effects.Specifically,the ACI mainly enhanced the formation of ice-phase hydrometeors within the upper level of the eyewall with more freezing latent heat releases,leading to an invigoration of eyewall convection.These excess ice-phase particles melted after they descended into the warm layer below the 0°C level,which accelerated the accretion of cloud droplets by raindrops(Pcacr)and hence the mixed phase precipitation process in the eyewall.The dynamic feedback induced by the ACI enhanced the boundary layer inflow and the upper layer outflow,supporting the maintenance of strong eyewall convection and intensification of the typhoon.Inversely,the ARI heated the distant periphery low-level atmosphere at an altitude of 1-2 km by the absorbing polluted aerosols.The heated air,driven by the radial inflow,firstly went through the periphery rainbands of the typhoon and invigorated convection there due to the low-level warming.Then,the enhanced periphery convection inhibited the further transport of warm moist air into the eyewall,resulting in weakening of the eyewall convection and hence typhoon intensity.In sum,for the polluted scenario,as the typhoon approached the continent,ARI played a dominant role over ACI.The WRF-Chem model with full consideration of aerosol-cloud-radiation interactions is advantageous in terms of reliably simulating typhoon intensity and precipitation distribution.展开更多
Introduction COVID-19,caused by SARS-CoV-2,is a highly contagious disease.1 By April 8,2020,more than 1,350,000 patients were diagnosed with COVID-19 globally,with more than 79,000 deaths worldwide attributable to the...Introduction COVID-19,caused by SARS-CoV-2,is a highly contagious disease.1 By April 8,2020,more than 1,350,000 patients were diagnosed with COVID-19 globally,with more than 79,000 deaths worldwide attributable to the disease.2 Recent clinical data reported that mild and critical patients manifested different symptoms.Most of the mild patients with COVID-19 had symptoms such as fever,cough,and mild pneumonia,whereas the critical cases presented dyspnea,respiratory failure,sepsis,organ dysfunction,and even eventual death.展开更多
At present,severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)spread worldwide,which has emerged multiple variants and brought a threat to global public health.To analyze the genomic characteristics and variat...At present,severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)spread worldwide,which has emerged multiple variants and brought a threat to global public health.To analyze the genomic characteristics and variations of SARS-CoV-2 imported into Beijing,we collected the respiratory tract specimens of 112 cases of coronavirus disease 2019(COVID-19)from January to September 2021 in Beijing,China,including 40 local cases and 72 imported cases.The whole-genome sequences of the viruses were sequenced by the next-generation sequencing method.Variant markers and phylogenic features of SARS-CoV-2 were analyzed.Our results showed that in all 112 sequences,the mutations were concentrated in spike protein.D614G was found in all sequences,and mutations including L452R,T478K,P681R/H,and D950N in some cases.Furthermore,112 sequences belonged to 23 lineages by phylogenetic analysis.B.1.1.7(Alpha)and B.1.617.2(Delta)lineages were dominant.Our study drew a variation image of SARS-CoV-2 and could help evaluate the potential risk of COVID-19 for pandemic preparedness and response.展开更多
基金sponsored by the National Natural Science Foundation (81822050,81920108032)Young Qihuang Scholar of State Administration of Traditional Chinese Medicine of Qianqian Liang,Innovation Team Project of the Scientific Research Project of Traditional Chinese Medicine of Shanghai Health Committee (2022CX001)+2 种基金Shanghai Hospital Chinese Medicine Preparation Industry Transformation Synergy Innovation Center of Qianqian Liang,Program for Innovative Research Team of Ministry of Science and Technology of China (2015RA4002),“Innovation Team”Development Projects (IRT1270)Shanghai TCM Medical Center of Chronic Disease (2022ZZ01009)Jing’an District Health Research Project of Shanghai (2022MS03).
文摘Objective:Rheumatoid arthritis(RA)is a common autoimmune disease characterized by multiple joint lesions and systemic complications.Danggui Niantong decoction(DGNTT)has been clinically used for RA treatment;however,its beneficial effect on cardiopulmonary complications has not been reported.Methods:Female tumor necrosis factor-transgenic(TNF-Tg)mice were used to evaluate the therapeutic effects of DGNTT on arthritis and cardiopulmonary complications.Methotrexate(MTX)served as a positive control.Histopathological assessment of the joint sections was performed using hematoxylin and eosin(HE),Alcian Blue/Orange G,and tartrate-resistant acid phosphatase staining.Bone mass was assessed by micro-computed tomography,inflammatory infiltrates in the heart and lungs were evaluated by HE staining,cardiopulmonary fibrotic injury was identified by Masson’s trichrome staining,and hypertrophy of mouse cardiomyocytes was measured by wheat germ agglutinin(WGA)staining.Results:DGNTT mitigated the inflammation of the ankle joint synovium,decreased the number of osteoclasts,and increased the area of cartilage and bone mass in TNF-Tg mice.In addition,DGNTT decreased the infiltration of inflammatory cells into the lung and heart tissues,accompanied by a reduction in cardiopulmonary fibrosis and myocardial cell hypertrophy in TNF-Tg mice.As a positive control drug,MTX attenuated the pathological changes in joints,but had no beneficial effect on cardiopulmonary inflammation and fibrosis in TNF-Tg mice.Conclusions:DGNTT improved joint lesions and alleviated cardiopulmonary complications in TNF-Tg mice.
基金supported by the Special Fund for Novel Coronavirus Pneumonia from the Department of Science and Technology of Hubei Province(2020FCA035)the Fundamental Research Funds for the Central Universities,Huazhong University of Science and Technology(2020kfyXGYJ023).
文摘Coronavirus disease 2019(COVID-19)has become a worldwide pandemic.Hospitalized patients of COVID-19 suffer from a high mortality rate,motivating the development of convenient and practical methods that allow clinicians to promptly identify high-risk patients.Here,we have developed a risk score using clinical data from 1479 inpatients admitted to Tongji Hospital,Wuhan,China(development cohort)and externally validated with data from two other centers:141 inpatients from Jinyintan Hospital,Wuhan,China(validation cohort 1)and 432 inpatients from The Third People’s Hospital of Shenzhen,Shenzhen,China(validation cohort 2).The risk score is based on three biomarkers that are readily available in routine blood samples and can easily be translated into a probability of death.The risk score can predict the mortality of individual patients more than 12 d in advance with more than 90%accuracy across all cohorts.Moreover,the Kaplan-Meier score shows that patients can be clearly differentiated upon admission as low,intermediate,or high risk,with an area under the curve(AUC)score of 0.9551.In summary,a simple risk score has been validated to predict death in patients infected with severe acute respiratory syndrome coronavirus 2(SARS-CoV-2);it has also been validated in independent cohorts.
基金supported by Science Program of Beijing City[grant number Z221100007922019]the High Level Public Health Technical Talent Training Plan[grant number xuekegugan-01-019]National Key Research and Development Project of China[grant number 2023YFC0872400]。
文摘In response to problems of poor sampling quality,low sensitivity,and high demand for medical personnel regarding the current severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)oropharyngeal(OP)swab sampling used in China,we aimed to evaluate the diagnostic performance and acceptability of saliva-based nucleic acid amplification tests(NAATs)in China.The results showed that,using nasopharyngeal(NP)swab results as the gold standard,the overall sensitivities for saliva specimens and OP swabs were 93.3%and 85.0%,the specificities were 92.6%and 93.8%,respectively.The results of an acceptability survey showed that the scores for saliva,OP,and NP samples were 9.46±1.69,8.11±2.42,and 4.58±3.82 out of 10,respectively,with significant differences among the three groups(P<0.05).With higher sensitivity,comparable specificity,and strong public preference,saliva-based NAATs represent a convenient and effective method for detecting SARS-CoV-2 in future epidemics.
基金Supported by the National Key Research and Development Program of China(2021ZD0114103).
文摘Summary What is already known about this topic?Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)continues to evolve,the clinical manifestations resulting from different SARS-CoV-2 variants may demonstrate significant variation.What is added by this report?We conducted a comparative analysis of the clinical features associated with SARS-CoV-2 Omicron subvariants BF.7.14 and BA.5.2.48 infections.The results of our study indicate that there are no substantial differences in clinical manifestations,duration of illness,healthcare-seeking behaviors,or treatment between these two subvariants.What are the implications for public health practice?Timely identification of alterations in the clinical spectrum is crucial for researchers and healthcare practitioners in order to enhance their comprehension of clinical manifestations,as well as the progression of SARS-CoV-2.Furthermore,this information is beneficial for policymakers in the process of revising and implementing appropriate countermeasures.
基金the financial support from the National Natural Science Foundation of China(Nos.11772022,51575022 and 51475021)
文摘Intermittent rub-impact, during which the contact between rotor and stator is characterized by a ‘‘bouncing" or intermittent type of behavior, is one of the most common rubbing forms in rotating machinery. When the intermittent rub-impact occurs, the non-smooth constraint, which is the phenomenon that the system stiffness changes with respect to the state of contact and noncontact, will appear. The paper aims at discovering the possible effects of the non-smooth constraint on the flexible rotor's modal characteristics by theoretical and experimental methods. The qualitative description for non-smooth constraint is given for the intermittent rub-impact process, and the dynamic modeling for a rotor system with non-smooth constraint is carried out. Meanwhile, the analysis method is developed by Floquet theory and Hill's method to obtain the rotor's modal characteristics. The results reveal that the non-smooth constraint produced by the intermittent rubimpact will increase the modal frequencies and critical speeds of the rotor system significantly.Due to the time-varying features of the constraint stiffness, the modal frequencies for the intermittent rub-impact rotor present fluctuant changes with the increase of rotation speed, which is different from the general linear rotor system. The non-smooth constraint is possible to lead the rotor's instability, and the rotor's instable regions can be expanded significantly for the increase of average constraint stiffness, constraint amplitude and contact time ratio. Non-smooth constraint could also expand the resonance speed and resonance sideband of the rotor system, which sometimes results in amplitude jump phenomenon.
基金the financial support from the National Natural Science Foundation of China(Nos.51575022 and 51475021)
文摘Fan blade off(FBO) from a running turbofan rotor will introduce sudden unbalance into the dynamical system,which will lead to the rub-impact,the asymmetry of rotor and a series of interesting dynamic behavior.The paper first presents a theoretical study on the response excited by sudden unbalance.The results reveal that the reaction force of the bearing located near the fan could always reach a very high value which may lead to the crush of ball,journal sticking,high stress on the other components and some other failures to endanger the safety of engine in FBO event.Therefore,the dynamic influence of a safety design named ‘‘fusing" is investigated by mechanism analysis.Meantime,an explicit FBO model is established to simulate the FBO event,and evaluate the effectiveness and potential dynamic influence of fusing design.The results show that the fusing design could reduce the vibration amplitude of rotor,the reaction force on most bearings and loads on mounts,but the sudden change of support stiffness induced by fusing could produce an impact effect which will couple with the influence of sudden unbalance.Therefore,the implementation of the design should be considered carefully with optimized parameters in actual aero-engine.
基金Supported by the National Natural Science Foundation of China(41775017 and 41675058)。
文摘Capture of a strong elevated ducting event,especially its maintenance and sudden change,is of great value to airborne radar to achieve its beyond-the-line-of-sight detection.However,the knowledge is not easily accessible over the open ocean and hence very rare.During the Air–Sea Interaction Survey(ASIS)over the western North Pacific(WNP)in May 2016,a strong elevated ducting event with a long-life period and sudden change in its evolution was observed.Measurements from the ASIS,images from the Himawari-8 satellite,reanalysis data from the ECMWF,and Weather Research and Forecasting(WRF)model,were used to analyze the maintenance and sudden change of this strong ducting event,together with the model performance on simulating it.The results showed that the maintenance of strong elevated ducts,with their tops ranging from 750 to 1050 m and average strength of approximately 38 M units,was caused by a strong dry air mass capping over the wet marine atmospheric boundary layer(MABL),together with the subsidence inversion associated with high pressure.The WRF model performs well in simulating them.However,a sudden increase in duct height with a slight decrease of strength was recorded by the subsequent GPS radiosonde,which was finally contributed to the mechanical turbulent inversion and hydrolapse associated with the marine low-level jet(MLLJ).The height of the maximum horizontal wind speed(Umh)of the MLLJ corresponds well with the bottom of the trapping layer.However,these jet-relevant ducts are generally weak and it is difficult to accurately simulate them by using the mesoscale numerical model,since the wind-shear produced eddies are too small to be properly parameterized.
基金Funded by The Capital Health Development and Research of Special(2021-1G-3012)Beijing Science and Technology Planning Project(Z201100005420010)and(Z211100002521019)Beijing Talent Project(2020A050,2020A051).
文摘On January 15,2022,a 26 years old female(Case A)went to a sampling site for coronavirus disease 2019(COVID-19)testing due to excessive fatigue and fever for two days.This patient preliminarily tested positive for severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)using a quantitative real-time reverse transcription polymerase chain reaction(qRT-PCR)method.
基金supported by the Capital's Funds for Health Improvement and Research(Project No.2021-1G-3012,2022-2G-30115)the Beijing Science and Technology Planning Project of Beijing Science and Technology Commission(Project No.Z211100002521019).
文摘Omicron(B.1.1.529),the fifth variant of concern(VOC)of severe acute respiratory syndrome coronavirus 2(SARS‐CoV‐2),was firstly identified in November 2021 in South Africa.Omicron contains far more genome mutations than any other VOCs ever found,raising significant concerns about its increased transmissibility and immune evasion.Here,we report the importation of the Omicron variant into Beijing,China,in December 2021.Full‐length genome sequences of five imported strains were obtained,with their genetic features characterized.Each strain contained 57 to 61 nucleotide substitutions,39 deletions,and 9 insertions in the genome.Thirty to thirty‐two amino acid changes were found in the spike proteins of the five strains.The phylogenetic tree constructed by the maximum likelihood method showed that all five imported genomes belonged to Omicron(BA.1)(alias of B.1.1.529.1),which is leading to the current surge of coronavirus disease 2019(COVID‐19)cases worldwide.The globally increased COVID‐19 cases driven by the Omicron variant pose a significant challenge to disease prevention and control in China.Continuous viral genetic surveillance and increased testing among international travellers are required to contain this highly contagious variant.
文摘Summary What is already known about this topic?Inhalational anthrax,also known as pulmonary anthrax,is an infectious disease caused by Bacillus anthracis.The patients are usually infected by inhaling aerosolized B.anthracis spores from dead animals or animal products.Compared to cutaneous anthrax,inhalational anthrax is rare and deadly and few cases in China were reported.What is added by this report?This report covers all information of clinical features,laboratory testing,and epidemiological characteristics as well as exposure history of a recent primary inhalational anthrax patient who was seeking medical treatment in Beijing Municipality in August 2021.New laboratory techniques,including second-generation sequencing,polymerase chain reaction,and rapid test for serum antibody,played an important role in the process.What are the implications for public health practice?The information provided in this report,including the correct sample type,epidemiological investigation details,and application of the new diagnostic criteria of anthrax,could assist public health professionals in dealing with anthrax epidemics.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.41775017&41675058).
文摘As a typhoon approaches the continent,the position where anthropogenic aerosols penetrate,the convection competition between the eyewall and peripheral rainbands,and the separate contributions of direct aerosol-radiation interactions(ARI)and indirect aerosol-cloud interactions(ACI),yield uncertainties in the convection intensification area and hence the typhoon intensity.Typhoon Lupit(2009)was simulated using the Weather Research and Forecasting Model with Chemistry(WRF-Chem)to investigate and isolate the direct and indirect effects of aerosols on the intensity,convection,and precipitation of the typhoon.Three simulations(CTL,CLEAN,and CTLARIOFF)were designed,representing a polluted case(CTL,considering the ingestion of anthropogenic aerosols with ARI and ACI),a clean maritime case(CLEAN,mainly with sea salt aerosols),and a polluted case without aerosol radiative forcing(CTLARIOFF,as per CTL but without ARI).The results showed that anthropogenic aerosols could penetrate into both the peripheral rainbands and the eyewall when the typhoon was approaching the Asian continent.Owing to the representation of the real aerosol scenario,the simulated typhoon intensity weakened and was closer to observed values in the CTL experiment.The ARI dominated over ACI with the opposite effects.Specifically,the ACI mainly enhanced the formation of ice-phase hydrometeors within the upper level of the eyewall with more freezing latent heat releases,leading to an invigoration of eyewall convection.These excess ice-phase particles melted after they descended into the warm layer below the 0°C level,which accelerated the accretion of cloud droplets by raindrops(Pcacr)and hence the mixed phase precipitation process in the eyewall.The dynamic feedback induced by the ACI enhanced the boundary layer inflow and the upper layer outflow,supporting the maintenance of strong eyewall convection and intensification of the typhoon.Inversely,the ARI heated the distant periphery low-level atmosphere at an altitude of 1-2 km by the absorbing polluted aerosols.The heated air,driven by the radial inflow,firstly went through the periphery rainbands of the typhoon and invigorated convection there due to the low-level warming.Then,the enhanced periphery convection inhibited the further transport of warm moist air into the eyewall,resulting in weakening of the eyewall convection and hence typhoon intensity.In sum,for the polluted scenario,as the typhoon approached the continent,ARI played a dominant role over ACI.The WRF-Chem model with full consideration of aerosol-cloud-radiation interactions is advantageous in terms of reliably simulating typhoon intensity and precipitation distribution.
基金We thank the patients,nurses,and physicians who pro-vided care for the patients,and the investigators at the Third People's Hospital of Shenzhen.This work is supported by grants from the Science and Technology Innovation Committee of Shenzhen Municipality(202002073000001)National Key Research and Development Program(2020YFC0841700)+1 种基金High-level University Fund(no.G02386301,G02386401)Guangdong Natural Science Foundation Joint Fund(no.2019A1515111038).
文摘Introduction COVID-19,caused by SARS-CoV-2,is a highly contagious disease.1 By April 8,2020,more than 1,350,000 patients were diagnosed with COVID-19 globally,with more than 79,000 deaths worldwide attributable to the disease.2 Recent clinical data reported that mild and critical patients manifested different symptoms.Most of the mild patients with COVID-19 had symptoms such as fever,cough,and mild pneumonia,whereas the critical cases presented dyspnea,respiratory failure,sepsis,organ dysfunction,and even eventual death.
基金This study was funded by the National Key R&D Program of China(2021ZD0114100 and 2021ZD0114103)the Capital’s Funds for Health Improvement and Research(2021-1G-3012 and 2022-4G-30117)the Beijing Science and Technology Planning Project of Beijing Science and Technology Commission(Z211100002521015).In addition,we thank the health workers who contributed to the epidemiological survey,sample collection,and transportation.
文摘At present,severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)spread worldwide,which has emerged multiple variants and brought a threat to global public health.To analyze the genomic characteristics and variations of SARS-CoV-2 imported into Beijing,we collected the respiratory tract specimens of 112 cases of coronavirus disease 2019(COVID-19)from January to September 2021 in Beijing,China,including 40 local cases and 72 imported cases.The whole-genome sequences of the viruses were sequenced by the next-generation sequencing method.Variant markers and phylogenic features of SARS-CoV-2 were analyzed.Our results showed that in all 112 sequences,the mutations were concentrated in spike protein.D614G was found in all sequences,and mutations including L452R,T478K,P681R/H,and D950N in some cases.Furthermore,112 sequences belonged to 23 lineages by phylogenetic analysis.B.1.1.7(Alpha)and B.1.617.2(Delta)lineages were dominant.Our study drew a variation image of SARS-CoV-2 and could help evaluate the potential risk of COVID-19 for pandemic preparedness and response.