目的调查空军某部地面机务人员下腰痛(low back pain,LBP)的发生率及相关致病因素,为有针对性地做好下腰痛防治工作提供依据。方法采用流行病学问卷调查及查体相结合的方法,自行设计《空军部队机务人员下腰痛调查问卷》,抽取某部机务人...目的调查空军某部地面机务人员下腰痛(low back pain,LBP)的发生率及相关致病因素,为有针对性地做好下腰痛防治工作提供依据。方法采用流行病学问卷调查及查体相结合的方法,自行设计《空军部队机务人员下腰痛调查问卷》,抽取某部机务人员261名,对下腰痛的发病情况和相关影响因素进行多因素Logistic回归分析。结果在接受调查的机务人员中,63名诊断为下腰痛,发病率为24.1%;下腰痛的发生与工作年限及每次进场工作时间有明显的相关性,装挂副油箱、挂弹、抬弹及发动机舱内操作等工作被认为是容易诱发下腰痛的训练项目。结论空军机务人员中下腰痛发病率较高,针对其职业特点,应加强防护措施的研究,同时增加腰背肌功能锻炼,以降低其发病率,提高飞行训练保障能力。展开更多
The coronavirus disease 2019(COVID-19)pandemic caused by frequently mutating severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has had a worldwide impact.However,detailed data on the potential aerosol transmi...The coronavirus disease 2019(COVID-19)pandemic caused by frequently mutating severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has had a worldwide impact.However,detailed data on the potential aerosol transmission of SARS-CoV-2 in real-world and controlled laboratory settings remain sparse.During the COVID-19 pandemic in Shanghai,China in 2022,samples were collected in a Fangcang shelter hospital,a large-scale temporary hospital rapidly built by converting the existing National Exhibition and Convention Center(Shanghai)into a health care facility.Aerosol samples at different sites and intervals around patients and in public areas,surface samples,and pharyngeal swab samples from corresponding patients were included.Samples were tested for SARS-CoV-2 using real-time quantitative polymerase chain reaction(RT-qPCR)assays,followed by sequencing if the cycle threshold(Ct)value was<30.The positivity rate for SARS-CoV-2 in aerosol samples was high in contaminated zones(37.5%,104/277),especially around the bed(41.2%,68/165)and near ventilation inlets(45.2%,14/31).The prevalence of SARS-CoV-2 around the bed,public areas,and air inlets of exhaust vents fluctuated and was closely related to the positivity rate among patients at corresponding sampling sites.Some surface samples of different personal protective equipment from medical staff had high positivity rates.Sixty sequences of joined ORF1ab and spike genes obtained from sixty samples represented two main clusters of Omicron SARS-CoV-2.There was consistency in virus sequences from the same patient and their environment,and the detected virus sequences matched those of virus strains in circulation during the collection periods,which indicated a high likelihood of cross-contamination in the Fangcang shelter hospital.In summary,the results provide a quantitative and real landscape of the aerosol transmission of SARS-CoV-2 and a patient-centered view of contamination in large and enclosed spaces and offer a useful guide for taking targeted measures to avoid nosocomi展开更多
Stimuli-responsive macrocycles are of importance for synthetic chemistry and smart materials. In this manuscript, we report two novel organoborane cyclophanes, which were successfully synthesized by ruthenium-catalyze...Stimuli-responsive macrocycles are of importance for synthetic chemistry and smart materials. In this manuscript, we report two novel organoborane cyclophanes, which were successfully synthesized by ruthenium-catalyzed olefin metathesis. They are composed of one/two boron-doped helicene π-skeletons and flexible alkyl chain linkers, thus representing a new kind of non-conjugated organoborane macrocycles. Their cyclic structures and photophysical properties, as well as Lewis acidity were theoretically and experimentally investigated. Notably, two enantiomers in one single crystal are observed for one organoborane cyclophane, owning to the presence of helical π-framework in its cyclic structure. Moreover, their Lewis acid-base adducts may dissociate in the excited state and thus display intriguing photo-responsive fluorescence properties, which can be further modulated by temperature. This study thus provides a novel design strategy for non-conjugated organoborane macrocycles, which may promote the development of stimuli-responsive macrocyclic materials with fascinating properties.展开更多
文摘目的调查空军某部地面机务人员下腰痛(low back pain,LBP)的发生率及相关致病因素,为有针对性地做好下腰痛防治工作提供依据。方法采用流行病学问卷调查及查体相结合的方法,自行设计《空军部队机务人员下腰痛调查问卷》,抽取某部机务人员261名,对下腰痛的发病情况和相关影响因素进行多因素Logistic回归分析。结果在接受调查的机务人员中,63名诊断为下腰痛,发病率为24.1%;下腰痛的发生与工作年限及每次进场工作时间有明显的相关性,装挂副油箱、挂弹、抬弹及发动机舱内操作等工作被认为是容易诱发下腰痛的训练项目。结论空军机务人员中下腰痛发病率较高,针对其职业特点,应加强防护措施的研究,同时增加腰背肌功能锻炼,以降低其发病率,提高飞行训练保障能力。
基金supported by National Key Research and Development Program of China(2019YFC1200500)supported by Emergency Key Program of Guangzhou Laboratory(EKPG21-01)supported by National Natural Science Foundation of China(32070166)。
文摘The coronavirus disease 2019(COVID-19)pandemic caused by frequently mutating severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has had a worldwide impact.However,detailed data on the potential aerosol transmission of SARS-CoV-2 in real-world and controlled laboratory settings remain sparse.During the COVID-19 pandemic in Shanghai,China in 2022,samples were collected in a Fangcang shelter hospital,a large-scale temporary hospital rapidly built by converting the existing National Exhibition and Convention Center(Shanghai)into a health care facility.Aerosol samples at different sites and intervals around patients and in public areas,surface samples,and pharyngeal swab samples from corresponding patients were included.Samples were tested for SARS-CoV-2 using real-time quantitative polymerase chain reaction(RT-qPCR)assays,followed by sequencing if the cycle threshold(Ct)value was<30.The positivity rate for SARS-CoV-2 in aerosol samples was high in contaminated zones(37.5%,104/277),especially around the bed(41.2%,68/165)and near ventilation inlets(45.2%,14/31).The prevalence of SARS-CoV-2 around the bed,public areas,and air inlets of exhaust vents fluctuated and was closely related to the positivity rate among patients at corresponding sampling sites.Some surface samples of different personal protective equipment from medical staff had high positivity rates.Sixty sequences of joined ORF1ab and spike genes obtained from sixty samples represented two main clusters of Omicron SARS-CoV-2.There was consistency in virus sequences from the same patient and their environment,and the detected virus sequences matched those of virus strains in circulation during the collection periods,which indicated a high likelihood of cross-contamination in the Fangcang shelter hospital.In summary,the results provide a quantitative and real landscape of the aerosol transmission of SARS-CoV-2 and a patient-centered view of contamination in large and enclosed spaces and offer a useful guide for taking targeted measures to avoid nosocomi
基金supported by the National Natural Science Foundation of China (Nos. 22175074, 21822507)。
文摘Stimuli-responsive macrocycles are of importance for synthetic chemistry and smart materials. In this manuscript, we report two novel organoborane cyclophanes, which were successfully synthesized by ruthenium-catalyzed olefin metathesis. They are composed of one/two boron-doped helicene π-skeletons and flexible alkyl chain linkers, thus representing a new kind of non-conjugated organoborane macrocycles. Their cyclic structures and photophysical properties, as well as Lewis acidity were theoretically and experimentally investigated. Notably, two enantiomers in one single crystal are observed for one organoborane cyclophane, owning to the presence of helical π-framework in its cyclic structure. Moreover, their Lewis acid-base adducts may dissociate in the excited state and thus display intriguing photo-responsive fluorescence properties, which can be further modulated by temperature. This study thus provides a novel design strategy for non-conjugated organoborane macrocycles, which may promote the development of stimuli-responsive macrocyclic materials with fascinating properties.
