煤烟型氟中毒的毒理-流行病学研究

煤烟型地方性氟中毒是国内近十年来提出的新的环境卫生问题。依据有关的调查研究报告,本文概述了煤烟型氟中毒的毒理-流行病学研究结果,为制订适合于这类病区的环境氟的卫生标准提供了参考资料。

Associated factors of professional identity among nursing undergraduates during COVID-19:A cross-sectional study

Objectives Professional identity plays an important role in the long-term development of nurses,and it will change when public health emergency occurs.The objective of this study is to investigate the factors associated with the professional identity of nursing undergraduates in the epidemic of COVID-19.Methods A cross-sectional survey design with convenience sampling was used.A total of 3,875 nursing undergraduates were recruited from seven universities across China from March to April 2020.A general information questionnaire was used to collect students’information,and the Professional Identity Questionnaire for Nurse Students was used to survey their professional identity during the early and later stages of the first wave of the COVID-19 epidemic.Results The score of professional identity in the later stage(59.49±12.41)was higher than that in the early stage(56.96±12.61).The stepwise regression indicated that several factors were associated with professional identity,including gender,residential area,major,impact of the epidemic on intention to work after graduation,reasons for choosing nursing major and students’scores of professional identity in early stage.Conclusions Nursing educators can utilize the positive impact of responding to public health emergencies to increase the professional identity of students.Meanwhile,educators should give those students with lower professional identity more targeted education to cultivate their professional identity after the occurrence of public health emergencies.

Inference of Global HIV-1 Sequence Patterns and Preliminary FeatureAnalysis

The epidemiology of HIV-1 varies in different areas of the world, and it is possible that this complexity may leave unique footprints in the viral genome. Thus, we attempted to find significant patterns in global HIV-1 genome sequences. By applying the rule inference algorithm RIPPER (Repeated Incremental Pruning to Produce Error Reduction) to multiple sequence alignments of Env sequences from four classes of compiled datasets, we generated four sets of signature patterns. We found that these patterns were able to distinguish southeastern Asian from non- southeastern Asian sequences with 97.5% accuracy, Chinese from non-Chinese sequences with 98.3% accuracy, African from non-African sequences with 88.4% accuracy, and southern African from non-southern African sequences with 91.2% accuracy. These patterns showed different associations with subtypes and with amino acid positions. In addition, some signature patterns were characteristic of the geographic area from which the sample was taken. Amino acid features corresponding to the phylogenetic clustering of HIV-1 sequences were consistent with some of the deduced patterns. Using a combination of patterns inferred from subtypes B, C, and all subtypes chimeric with CRF01_AE worldwide, we found that signature patterns of subtype C were extremely common in some sampled countries (for example, Zambia in southern Africa), which may hint at the origin of this HIV-1 subtype and the need to pay special attention to this area of Africa. Signature patterns of subtype B sequences were associated with different countries. Even more, there are distinct patterns at single position 21 with glycine, leucine and isoleucine corresponding to subtype C, B and all possible recombination forms chimeric with CRF01_AE, which also indicate distinct geographic features. Our method widens the scope of inference of signature from geographic, genetic, and genomic viewpoints. These findings may provide a valuable reference for epidemiological research or vaccine design.

Medical Virology in Malaysia

Virology is a branch of biological science dealing with the study of viruses,and medical virology focuses on the study and control of diseases due to viruses that is of medical importance. The development of medical virology in Malaysia has its beginning in the Institute for Medical Research(IMR) ,following the establishment of the Division of Medical Zoology and Virus Research in the institute on 23 March 1953. The second institution in the country to establish diagnostic and research work in medical virology was Department of Medical Microbiology,Faculty of Medicine,University Malaya. This was followed by University Kebangsaan Malaysia,University Sains Malaysia and University of Sarawak Malaysia. The National Public Health Laboratory(NPHL) is the latest institution to establish a laboratory in 2003 for virus isolation and services to support country surveillance and outbreak investigation of infectious diseases due to viruses. In the field of medical virology,Malaysia contributed substantially in the areas of virus diagnostic services,development and research ranging from survey and documentation on the existence and prevalence of viruses causing diseases in Malaysia,clinical presentation and epidemiological features of virus diseases,evaluation of new diagnostic tests to pathogenesis of viral diseases. Malaysia contributed to the discoveries of at least 12 new viruses in the world. ASEAN plus Three(China,Japan,Republic of Korea) Emerging Infectious Programme was established to overcome the challenges and impact of emerging and re-emerging infectious diseases in this region. Malaysia as the co-ordinator of the laboratory component of the programme,contributed to strengthen the regional laboratory capability,capacity,laboratory-based surveillance and networking. The future of medical virology in Malaysia in terms of integration of diagnostic,reference and research to support the country's need will be enhanced and strengthened with the on-going development of the National Centre for Disease Control and Prevention(CDC Malaysia) which also incorporates a futuristic Special Diagnostic and Reference Laboratory.

An overview of COVID-19

Pneumonia caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection emerged in Wuhan City,Hubei Province,China in December 2019.By Feb.11,2020,the World Health Organization(WHO)officially named the disease resulting from infection with SARS-Co V-2 as coronavirus disease 2019(COVID-19).COVID-19 represents a spectrum of clinical manifestations that typically include fever,dry cough,and fatigue,often with pulmonary involvement.SARS-CoV-2 is highly contagious and most individuals within the population at large are susceptible to infection.Wild animal hosts and infected patients are currently the main sources of disease which is transmitted via respiratory droplets and direct contact.Since the outbreak,the Chinese government and scientific community have acted rapidly to identify the causative agent and promptly shared the viral gene sequence,and have carried out measures to contain the epidemic.Meanwhile,recent research has revealed critical aspects of SARS-CoV-2 biology and disease pathogenesis;other studies have focused on epidemiology,clinical features,diagnosis,management,as well as drug and vaccine development.This review aims to summarize the latest research findings and to provide expert consensus.We will also share ongoing efforts and experience in China,which may provide insight on how to contain the epidemic and improve our understanding of this emerging infectious disease,together with updated guidance for prevention,control,and critical management of this pandemic.