Meta-analysis of the prevalence of Giardia duodenalis in sheep and goats in China.

Giardia duodenum (G. duodenalis) can cause giardiasis and infect a variety of hosts. So far, there have been no detailed data regarding the positive rate of G. duodenalis in sheep and goats in China. Here, a systematic literature review was carried out to investigate the epidemiology of G. duodenalis in sheep and goats in China. To perform the meta-analysis, the databases CNKI, VIP, WanFang, PubMed, Web of science and ScienceDirect were employed for screening studies related to the prevalence of G. duodenalis in sheep and goats in China. The total prevalence of G. duodenalis in sheep and goats was estimated to be 7.00% (95% CI: 4.00-10.00). In the age subgroup, the prevalence of G. duodenalis in sheep and goats of >12 months (11.29%; 95% CI: 8.08-14.97) was higher than that in sheep and goats of ≤12 months (7.57%; 95% CI: 3.95-12.24). An analysis based on seasons showed that the prevalence of G. duodenalis in sheep and goats was higher in summer (11.90%; 95% CI: 0.50-35.05) than that in other seasons. The prevalence of G. duodenalis in sheep and goats after 2016 was 8.57% (95% CI: 5.34-11.79), which was higher than others. The highest prevalence of G. duodenalis in sheep and goats was 13.06% (95% CI: 6.26-19.86) recorded in Southwestern China. The prevalence of Giardia infection in sheep (7.28%; 95% CI: 2.30-14.73) was higher than that in goats (5.43%; 95% CI: 2.73-8.98). The NOAA's National Center for Environmental Information (https://gis.ncdc.noaa.gov/maps/ncei/cdo/monthly) was used to extract relevant geoclimatic data (latitude, longitude, elevation, temperature, precipitation, humidity, and climate). By analyzing the data of each subgroup, it was shown that region, genetype, and climate were potential risk factors for giardiasis prevalence in sheep and goats. Based on the analysis of common factors and geographical factors, it is recommended to strengthen effective management measures (e.g. ventilation and disinfection in warm and humid areas) and formulate relevant policies according to local conditions. Breeders should strengthen the detection of G. duodenalis in sheep and goats, customize corresponding control measures according to the diet and living habits of sheep and goats, and strengthen the protection of sheep and lamb calves, so as to reduce the incidence rate and reduce the economic loss of China's animal husbandry.

The interplays among meteorology, source, and chemistry in high particulate matter pollution episodes in urban Shanghai, China.

High particulate matter (PM) pollution episodes still occur occasionally in urban China, despite of improvements in recent years. Investigating the influencing factors of high-PM episodes is beneficial in the formulation of effective control measures. We herein present the effects of weather condition, emission source, and chemical conversion on the occurrence of high-PM episodes in urban Shanghai using multiple online measurements. Three high-PM episodes, i.e., locally-accumulated, regionally-transported, and dust-affected ones, as well as a clean period were selected. Stagnant air with temperature inversion was found in both locally-accumulated and regionally-transported high-PM episodes, but differences in PM evolution were observed. In the more complicated dust-affected episode, the weather condition interacted with the emission/transport sources and chemical conversion, resulting in consecutive stages with different PM characteristics. Specifically, there were (1) stronger local accumulation in the pre-dust period, (2) dust-laden air with aged organic aerosol (OA) upon dust arrival, (3) pollutants being swept into the ocean, and (4) back to the city with aged OA. Our results suggest that (a) local emissions could be rapidly oxidized in some episodes but not all, (b) aged OA from long-range transport (aged in space) had a similar degree of oxygenation compared to the prolonged local oxidation (aged in time), and (c) OA aged over land and over the ocean were similar in chemical characteristics. The findings help better understand the causes and evolution of high-PM episodes, which are manifested by the interplays among meteorology, source, and chemistry, providing a scientific basis for control measures.

Iterative Synthesis of 2-Deoxyoligosaccharides Enabled by Stereoselective Visible-Light-Promoted Glycosylation.

The photoinitiated intramolecular hydroetherification of alkenols has been used to form C-O bonds, but the intermolecular hydroetherification of alkenes with alcohols remains an unsolved challenge. We herein report the visible-light-promoted 2-deoxyglycosylation of alcohols with glycals. The glycosylation reaction was completed within 2 min in a high quantum yield (ϕ=28.6). This method was suitable for a wide array of substrates and displayed good reaction yields and excellent stereoselectivity. The value of this protocol was further demonstrated by the iterative synthesis of 2-deoxyglycans with α-2-deoxyglycosidic linkages up to a 20-mer in length and digoxin with ß-2-deoxyglycosidic linkages. Mechanistic studies indicated that this reaction involved a glycosyl radical cation intermediate and a photoinitiated chain process.

Study on the influencing factors of turnover intention of pre-hospital emergency nurses in Beijing / 中华医院管理杂志

Objective:To explore the influencing factors of turnover intention of pre-hospital emergency nurses in Beijing, and provide references for reducing the turnover rate of pre-hospital emergency nurses and stabilizing the pre-hospital emergency nursing team.Methods:Pre-hospital emergency nurses from 2 emergency centers in Beijing were selected as the survey objects, and a self-designed questionnaire was used to conduct an online survey in September 2019. The questionnaire covered such aspects as the main demographic characteristics, workload, doctor-patient relationship, professional identity, job burnout and turnover intention. Descriptive analysis was conducted for the data, while rank-sum test and Kappa consistency test were used for univariate analysis, and ordered logistic regression analysis was used for multivariate analysis.Results:A total of 340 valid questionnaires were received, among which 41.5% (141) of the nurses said that they occasionally considered quitting, 11.7% (40) said they often considered quitting, while the scoring of professional identity was (33.29±6.00), and that of job burnout was (63.70±14.90). Univariate analysis showed that age, work units, self-rated health status, professional identity, job burnout, seniority, workload, doctor-patient relationship, and pressure of title promotion were significant ( P<0.05). The results of multivariate analysis showed that job burnout, average number of car trips per shift, and self-rated health status were positively correlated with turnover intention, while professional identity was negatively correlated with turnover intention ( P<0.05). Conclusions:The turnover intention of pre-hospital emergency nurses in Beijing was found at a high level. The authorities are recommended to rationalize the scheduling system and increase the staffing of pre-hospital emergency nurses; establish the diversion policy, title promotion system and post risk special allowance for such nurses; and train medical aid workers to undertake the transfer and lifting of patients, so as to reduce the turnover intention of these nurses.

Mechanism of Cordycepin Inhibiting Proliferation and Promoting Apoptosis of Hepatoma Cells by Regulating Gli1 / 中国实验方剂学杂志

ObjectiveTo investigate the molecular mechanism of cordycepin inhibiting proliferation and promoting apoptosis of human hepatoma cells （HCCs）. MethodGlioma-associated oncogene homolog 1 （Gli1） gene was silenced by small interfering RNA （siRNA） and transfected into SMMC-7721 cells， and then cell proliferation was detected by cell counting kit-8 （CCK-8） assay and cell cloning assay. SMMC-7721 cells were treated with different concentration of cordycepin， and the cell proliferation and apoptosis were examined. The expression of Gli1 and the downstream related genes was determined by Real-time polymerase chain reaction（PCR） and Western blot. ResultThe mRNA and protein expression of Gli1 in SMMC-7721 cells was higher than that in normal liver cells （P<0.01）. The proliferation rate of SMMC-7721 with silenced Gli1 decreased at 72 and 96 h （P<0.05， P<0.01）， and the colony-forming capacity lowered （P<0.01） compared with those in the blank group. Compared with the control， 80 μmol·L-1 and 120 μmol·L-1 cordycepin significantly inhibited the proliferation of SMMC-7721 cells at 72 and 96 h （P<0.05， P<0.01）， and promoted the apoptosis of them （P<0.01）. Moreover， 80 and 120 μmol·L-1 cordycepin restrained the mRNA and protein expression of Gli1 in SMMC7721 cells （P<0.05， P<0.01）. At 120 μmol·L-1， cordycepin led to the decrease in the mRNA and protein levels of B-cell lymphoma-2 （Bcl-2） and c-Myc （P<0.05， P<0.01）， and the increase in the mRNA and protein expression of cysteine-aspartic acid protease-3 （Caspase-3） （P<0.05）. ConclusionGli1 is highly expressed in HCCs， and cordycepin can suppress the proliferation and enhance the apoptosis of HCCs by regulating Gli1 and the downstream apoptosis-related factors.

Temporal Patterns of Bacterial and Viral Communities during Algae Blooms of a Reservoir in Macau.

Compositions of microbial communities associated with blooms of algae in a storage reservoir in Macau, China were investigated between 2013 and 2016. Algae were enumerated by visible light microscopy. Profiles of organisms in water were examined by 16S rRNA sequences and viral metagenomics, based on next generation sequencing. Results of 16S rRNA sequencing indicated that majority of the identified organisms were bacteria closely related to Proteobacteria, Cyanobacteria, Verrucomicrobia, Bacteroidetes, and Actinobacteria. Metagenomics sequences demonstrated that the dominant virus was Phycodnavirus, accounting for 70% of the total population. Patterns of relative numbers of bacteria in the microbial community and their temporal changes were determined through alpha diversity indices, principal coordinates analysis (PCoA), relative abundance, and visualized by Venn diagrams. Ways in which the bacterial and viral communities are influenced by various water-related variables were elucidated based on redundancy analysis (RDA). Relationships of the relative numbers of bacteria with trophic status in a reservoir used for drinking water in Macau, provided insight into associations of Phycodnavirus and Proteobacteria with changes in blooms of algae.

Enhanced Nitrite Production from the Aqueous Photolysis of Nitrate in the Presence of Vanillic Acid and Implications for the Roles of Light-Absorbing Organics.

A prominent source of hydroxyl radicals (•OH), nitrous acid (HONO) plays a key role in tropospheric chemistry. Apart from direct emission, HONO (or its conjugate base nitrite, NO2-) can be formed secondarily in the atmosphere. Yet, how secondary HONO forms requires elucidation, especially for heterogeneous processes involving numerous organic compounds in atmospheric aerosols. We investigated nitrite production from aqueous photolysis of nitrate for a range of conditions (pH, organic compound, nitrate concentration, and cation). Upon adding small oxygenates such as ethanol, n-butanol, or formate as •OH scavengers, the average intrinsic quantum yield of nitrite [Φ(NO2-)] was 0.75 ± 0.15%. With near-UV-light-absorbing vanillic acid (VA), however, the effective Φ(NO2-) was strongly pH-dependent, reaching 8.0 ± 2.1% at a pH of 8 and 1.5 ± 0.39% at a more atmospherically relevant pH of 5. Our results suggest that brown carbon (BrC) may greatly enhance the nitrite production from the aqueous nitrate photolysis through photosensitizing reactions, where the triplet excited state of BrC may generate solvated electrons, which reduce nitrate to NO2 for further conversion to nitrite. This photosensitization process by BrC chromophores during nitrate photolysis under mildly acidic conditions may partly explain the missing HONO in urban environments.

Metagenomic Analysis of Fecal Archaea, Bacteria, Eukaryota, and Virus in Przewalski's Horses Following Anthelmintic Treatment.

Intestinal microbiota is involved in immune response and metabolism of the host. The frequent use of anthelmintic compounds for parasite expulsion causes disturbance to the equine intestinal microbiota. However, most studies were on the effects of such treatment on the intestinal bacterial microbes; none is on the entire microbial community including archaea and eukaryotic and viral community in equine animals. This study is the first to explore the differences of the microbial community composition and structure in Przewalski's horses prior to and following anthelmintic treatment, and to determine the corresponding changes of their functional attributes based on metagenomic sequencing. Results showed that in archaea, the methanogen of Euryarchaeota was the dominant phylum. Under this phylum, anthelmintic treatment increased the Methanobrevibacter genus and decreased the Methanocorpusculum genus and two other dominant archaea species, Methanocorpusculum labreanum and Methanocorpusculum bavaricum. In bacteria, Firmicutes and Bacteroidetes were the dominant phyla. Anthelmintic treatment increased the genera of Clostridium and Eubacterium and decreased those of Bacteroides and Prevotella and dominant bacteria species. These altered genera were associated with immunity and digestion. In eukaryota, anthelmintic treatment also changed the genera related to digestion and substantially decreased the relative abundances of identified species. In virus, anthelmintic treatment increased the genus of unclassified_d__Viruses and decreased those of unclassified_f__Siphoviridae and unclassified_f__Myoviridae. Most of the identified viral species were classified into phage, which were more sensitive to anthelmintic treatment than other viruses. Furthermore, anthelmintic treatment was found to increase the number of pathogens related to some clinical diseases in horses. The COG and KEGG function analysis showed that the intestinal microbiota of Przewalski's horse mainly participated in the carbohydrate and amino acid metabolism. The anthelmintic treatment did not change their overall function; however, it displaced the population of the functional microbes involved in each function or pathway. These results provide a complete view on the changes caused by anthelmintic treatment in the intestinal microbiota of the Przewalski's horses.

Secondary Metabolite Production Potential of Mangrove-Derived Streptomyces olivaceus.

Mangroves are intertidal extreme environments with rich microbial communities. Actinobacteria are well known for producing antibiotics. The search for biosynthetic potential of Actinobacteria from mangrove environments could provide more possibilities for useful secondary metabolites. In this study, whole genome sequencing and MS/MS analysis were used to explore the secondary metabolite production potential of one actinobacterial strain of Streptomyces olivaceus sp., isolated from a mangrove in Macau, China. The results showed that a total of 105 gene clusters were found in the genome of S. olivaceus sp., and 53 known secondary metabolites, including bioactive compounds, peptides, and other products, were predicted by genome mining. There were 28 secondary metabolites classified as antibiotics, which were not previously known from S. olivaceus. ISP medium 2 was then used to ferment the S. olivaceus sp. to determine which predicted secondary metabolite could be truly produced. The chemical analysis revealed that ectoine, melanin, and the antibiotic of validamycin A could be observed in the fermentation broth. This was the first observation that these three compounds can be produced by a strain of S. olivaceus. Therefore, it can be concluded that Actinobacteria isolated from the mangrove environment have unknown potential to produce bioactive secondary metabolites.

Effects of Gasterophilus pecorum infestation on the intestinal microbiota of the rewilded Przewalski's horses in China.

Horse botflies have been a threat to the Przewalski's horses in the Kalamaili Nature Reserve in Xinjiang of China since their reintroduction to the original range. As larvae of these parasites could infest the intestine of a horse for months, they could interact with and alter the structure and composition of its intestinal microbiota, affecting adversely its health. Nonetheless, there are no such studies on the rewilded Przewalski's horses yet. For the first time, this study characterizes the composition of the intestinal microbiota of 7 rewilded Przewalski's horses infected severely by Gasterophilus pecorum following and prior to their anthelmintic treatment. Bioinformatics analyses of the sequence data obtained by amplicon high throughput sequencing of bacterial 16S rRNA genes showed that G. pecorum infestation significantly increased the richness of the intestinal microbial community but not its diversity. Firmicutes and Bacteroidetes were found the dominant phyla as in other animals, and the parasitic infestation decreased the F/B ratio largely by over 50%. Large reduction in relative abundances of the two genera Streptococcus and Lactobacillus observed with G. pecorum infestation suggested possible changes in colic and digestion related conditions of the infected horses. Variations on the relative abundance of the genus groups known to be pathogenic or symbiotic showed that adverse impact of the G. pecorum infestation could be associated with reduction of the symbiotic genera Lactobacillus and Bifidobacterium that are probiotics and able to promote immunity against parasitic infection.

Emission Inventories and Particulate Matter Air Quality Modeling over the Pearl River Delta Region.

The Pearl River Delta (PRD) region is located on the southeast coast of mainland China and it is an important economic hub. The high levels of particulate matter (PM) in the atmosphere, however, and poor visibility have become a complex environmental problem for the region. Air quality modeling systems are useful to understand the temporal and spatial distribution of air pollution, making use of atmospheric emission data as inputs. Over the years, several atmospheric emission inventories have been developed for the Asia region. The main purpose of this work is to evaluate the performance of the air quality modeling system for simulating PM concentrations over the PRD using three atmospheric emission inventories (i.e., EDGAR, REAS and MIX) during a winter and a summer period. In general, there is a tendency to underestimate PM levels, but results based on the EDGAR emission inventory show slightly better accuracy. However, improvements in the spatial and temporal disaggregation of emissions are still needed to properly represent PRD air quality. This study's comparison of the three emission inventories' data, as well as their PM simulating outcomes, generates recommendations for future improvements to atmospheric emission inventories and our understanding of air pollution problems in the PRD region.

Analysis on the equity of pediatrician resource allocation in Beijing / 中华医院管理杂志

Objective:To analyze the equity of pediatrician resource allocation in Beijing from 2010 to 2019, and to provide a reference for optimizing their allocation.Methods:The data of pediatrician resources in Beijing in 2010, 2014, and 2019 were collected. The resource agglomeration degree, Gini coefficient and Theil index method were used to analyze the fairness of resource allocation of pediatricians in functional areas in Beijing.Results:In 2010, 2014, and 2019, the Gini coefficients of Beijing′s overall pediatrician resources by the dimension of the number of children were 0.386, 0.276 and 0.286, respectively, an allocation relatively reasonable. But the Gini coefficients by that of geographic areas were 0.681, 0.578 and 0.537 respectively, still unreasonable. The resource allocation of pediatricians in the four regions was fair, but the aggregation degree of pediatricians in the central area of Beijing were 70.327, 59.243, and 53.220 in the three years, far higher than that in the urban functional development area, urban development new area and ecological conservation development area of the city.Conclusions:Beijing should rationally plan and allocate pediatrician resources, in order to minimize unequal resources allocation induced by regional differences. Such means as advancing the hierarchical diagnosis and treatment system and strengthening the construction of medical alliances are expected to gradually alleviate the conflicts between the growing demand for pediatrician resources and their unreasonable allocation.

Research on the organizational capability and maturity status of private hospitals in China / 中华医院管理杂志

Objective:To evaluate the current organizational capacity and maturity of private hospitals in China, in references improving their organizational capacity and promoting their sustainable development.Methods:The purposive sampling method was used from May to November 2019, and private hospitals of continuous operation for 5 years or above were selected for a questionnaire survey. Self-evaluation was made on the organization capacity of these hospitals in such 12 aspects as positioning, normalization, decision making, execution, supervision, marketing, coerciveness, risk exposure, innovation, learning capacity and leadership. Based on existing models, five levels of maturity models from low to high were established, namely that of business in difficulty, that of basic stable operation, that of stable development, that of expanding business, and that of independent branding.Factor analysis was used for structural efficiency analysis, the questionnaires were subject to a descriptive analysis, and a maturity scoring was obtained based on self-evaluation of organizational capacity.Results:A total of 45 non-public hospitals were investigated in this study, and 450 valid questionnaires were recovered. The factor analysis classified the organizational capacity into basic capacity, core capacity and development capacity. The organizational capability of the hospitals scored in average 4.14 points; the development capacity scoring(3.87 points) was lower than basic capacity(4.16 points) and core capacity(4.06 points). 80% of the private hospitals were in the basic stable stage or stable development stage.Conclusions:Private hospitals feature in general lower maturity, good basic capacity and core capacity, while they tend to have weak development capacity, not to mention innovation and construction of learning organizations.

Allogeneic Hematopoietic Stem Cell Transplantation for Paroxysmal Nocturnal Hemoglobinuria / 中国实验血液学杂志

OBJECTIVE@#To analyze the clinical efficacy and safety of allogeneic hematopoietic stem cell transplantation (allo-HSCT) for paroxysmal nocturnal hemoglobinuria (PNH), and preliminarily explore the role of an improved post-transplantation cyclophosphamide (PTCy) based conditioning regimen in PNH patients receiving transplantation.@*METHODS@#Clinical related data of PNH sufferers receiving allo-HSCT in Department of Hematology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology were collected, and hematopoietic reconstitution, chimerism, PNH cloning, graft-versus-host disease (GVHD), infection, and survival were analyzed.@*RESULTS@#Totally five PNH patients receiving allo-HSCT were enrolled, including 1 case with classic PNH, 3 cases with aplastic anemia-PNH syndrome, 1 case with myelodysplastic syndrome, three of them (case 1-3) received the improved PTCy based conditioning regimen before HSCT. All sufferers engrafted successfully within 28 days, the median time of neutrophil and platelet engraftment was 11 days and 12 days, respectively, no patient occurred acute or chronic GVHD, after a median follow-up of 16 months, all recipients survived and completely eliminated PNH cloning.@*CONCLUSION@#Allo-HSCT can completely clear PNH cloning and restore hematopoietic function with controllable complications, and the improved PTCy based conditioning regimen is proved to be effective in PNH transplantation.

Application and thoughts of team-based learning combined with flipped classroom in physiological teaching / 中华医学教育探索杂志

Objective:To explore the application and effect of team-based learning (TBL) combined with flipped classroom in the teaching of physiology.Methods:A total of 70 medical students were selected and randomly divided into two groups, experimental group ( n=34) and control group ( n=36). Both groups studied digestion physiology by different method. In the experimental group, the students were taught by TBL combined with flipped classroom. The control group was given traditional teaching. The students studied and discussed problems in a team, and shared the answers in the flipped classroom. The effects of teaching were evaluated by the final test scores and the self-made questionnaire. SPSS 17.0 was used for t test on data comparison between the two groups. Results:The test scores of digestion physiology in the experimental group were (5.47±1.02) points, which were significantly higher than those of the control group (4.42±1.63) points, with significant differences ( P=0.020). A total of 34 questionnaires were issued and 34 valid questionnaires were collected, with an effective rate of 100%. The questionnaire results showed that TBL combined with flipped classroom was accepted and approved by about 82% of students in the experimental group who agreed that the teaching model helps enhance students' initiative and interest in learning, develop their sense of cooperation and comprehensive application ability. Conclusion:TBL combined with flipped classroom is feasible and effective in the physiological teaching, and it can be popularized in medical courses.

Evaluation of homogenization effect of standardized residency training base of internal medicine in Beijing based on competency index / 中华医学教育探索杂志

Objective:To evaluate the homogenization effect of standardized residency training base of internal medicine and to provide reference for further improving the standardized residency training system.Methods:Taking all "unit residents" who took part in the standardized residency training test of Beijing resident physicians in 2015 and 2016 as the research objects, the self-assessment questionnaire survey of resident competency was carried out to analyze the training effect on competency. SPSS 21.0 was used to statistically analyze the collected data.Results:There are differences in self-assessment scores among the four system bases. From high to low, the overall self-assessment score are PUMCH, CCMU, the military, PUHSC. Among the eight abilities, the abilities of teaching and scientific research were the lowest.Conclusion:The training effect of Beijing internal medicine training base has not achieved homogenization. In order to improve the comprehensive ability of residents, it is suggested to strengthen the weak links in the standardized residency training from three aspects: teachers, training process and increasing support.

Power Management IC for a Dual-Input-Triple-Output Energy Harvester.

We present the design of a power management integrated circuit that processes harvested energy from radio frequency waves and piezoelectric vibrations. The rectification of piezoelectric and RF sources has a power conversion efficiency (PCE) of 87.73% and 74.70%, respectively. The asynchronous and microcontroller-less integrated circuit (IC) is designed to be low power, so the bulk of the harvested energy goes to three loads. The output peak powers of 111 µW, 156 µW, and 128 µW will be sufficient to run small devices for RF communication systems.

Exploring the Potential of Antibiotic Production From Rare Actinobacteria by Whole-Genome Sequencing and Guided MS/MS Analysis.

Actinobacteria are well recognized for their production of structurally diverse bioactive secondary metabolites, but the rare actinobacterial genera have been underexploited for such potential. To search for new sources of active compounds, an experiment combining genomic analysis and tandem mass spectrometry (MS/MS) screening was designed to isolate and characterize actinobacterial strains from a mangrove environment in Macau. Fourteen actinobacterial strains were isolated from the collected samples. Partial 16S sequences indicated that they were from six genera, including Brevibacterium, Curtobacterium, Kineococcus, Micromonospora, Mycobacterium, and Streptomyces. The isolate sp.01 showing 99.28% sequence similarity with a reference rare actinobacterial species Micromonospora aurantiaca ATCC 27029T was selected for whole genome sequencing. Organization of its gene clusters for secondary metabolite biosynthesis revealed 21 clusters encoded to antibiotic production, which is higher than other Micromonospora species. Of the genome-predicted antibiotics, kanamycin was found through guided MS/MS analysis producible by the M. aurantiaca strain for the first time. The present study highlighted that genomic analysis combined with MS/MS screening is a promising method to discover potential of antibiotic production from rare actinobacteria.

Knowledge, attitudes, and practices towards COVID-19 among primary and middle school students during the COVID-19 outbreak period in Beijing: An online cross-sectional survey

PurposeThis study investigated the KAP towards COVID-19 and their influencing factors among primary and middle school students during the self-quarantine period in Beijing. MethodsThis was a cross-sectional study among students from 18 primary and middle schools in Beijing during March 2020. Stratified cluster sampling was conducted. Demographic and KAP-related COVID-19 information was collected through an online questionnaire. The influencing factors were analyzed by multivariable logistic regression. ResultsA total of 7,377 students were included. The overall correct rate for COVID-19 knowledge was 74.1%, while only 31.5% and 40.5% could identify the high-risk places of cross-infection and warning body temperature. Although 94.5% of respondents believed the epidemic could be controlled, over 50% expressed various concerns about the epidemic. The compliance rates for basic preventing behaviors were all over 80%, while those for "rational and effective ventilation" (39.2%) and "dinning separately" (38.6%) were low. The KAP levels were significantly differed according to various school categories of students. The COVID-19 knowledge (OR= 3.309, 95% CI: 2.921, 3.748) and attitude (OR=1.145, 95% CI: 1.003, 1.308) were associated with preventive practices. Besides, female, urban students, those with a healthy lifestyle, and those with the willingness to engage in healthcare tended to have better preventive practices. ConclusionMost students in Beijing hold a high level of knowledge, optimistic attitudes and have appropriate practices towards COVID-19. However, targeted interventions are still necessary, especially for students with high-risk characteristics. Implications and contributionsThe performance and the potential factors of COVID-19-related knowledge, attitudes and practices (KAP) among students in primary and middle schools is still unclear. This study investigates the characteristics and the level of KAP among students. The results of the study may contribute to the targeted education and interventions for students.

Associations of ambient air pollutants and meteorological factors with COVID-19 transmission in 31 Chinese provinces: A time-series study

BackgroundEvidence regarding the effects of ambient air pollutants and meteorological factors on COVID-19 transmission is limited. ObjectivesTo explore the associations of air pollutants and meteorological factors with COVID-19 confirmed cases across 31 Chinese provinces during the outbreak period. MethodsThe number of COVID-19 confirmed cases, air pollutant concentrations and meteorological factors in 31 Chinese provinces from January 25 to February 29, 2020 were extracted from authoritative electronic databases. The associations were estimated for a single-day lag (lag0-lag6) as well as moving averages lag (lag01-lag05) using generalized additive mixed models (GAMMs), adjusted for time trends, day of the week, holidays and meteorological variables. Region-specific analyses and meta-analysis were conducted in five selected regions with diverse air pollution levels and weather conditions. Nonlinear exposure-response analyses were performed. ResultsWe examined 77,578 COVID-19 confirmed cases across 31 Chinese provinces during the study period. An increase of each interquartile range in PM2.5, PM10, SO2, NO2, O3 and CO at lag4 corresponded to 1.40 (1.37-1.43), 1.35 (1.32-1.37), 1.01 (1.00-1.02), 1.08 (1.07-1.10), 1.28 (1.27-1.29) and 1.26 (1.24-1.28) odds ratios (ORs) of daily COVID-19 confirmed new cases, respectively. For 1 {degrees}C, 1% and 1 m/s increase in temperature, relative humidity and wind velocity, the ORs were 0.97 (0.97-0.98), 0.96 (0.96-0.97), and 0.94 (0.92-0.95), respectively. The estimates of PM2.5, PM10, NO2 and all meteorological factors remained statistically significant after meta-analysis for the five selected regions. The exposure-response relationships showed that higher concentrations of air pollutants and lower meteorological factors were associated with daily COVID-19 confirmed new cases increasing. ConclusionsHigher air pollutant concentrations and lower temperature, relative humidity and wind velocity may favor COVID-19 transmission. As summer months are arriving in the Northern Hemisphere, the environmental factors and implementation of public health control measures may play an optimistic role in controlling COVID-19 epidemic.