Objective: To investigate the status of heat illness, knowledge awareness and adaptive behaviors of heat wave knowledge among food delivery riders, so as to provide a basis for optimizing heat wave response measures for food delivery riders. Methods: In November 2022, food delivery riders from a large food delivery platform in Ningbo City, Zhejiang Province were selected as survey subjects using a cluster sampling method. A self-designed electronic questionnaire was used to select demographic information, work status, lifestyle behaviors and disease history, heat illness status, knowledge awareness and adaptive behaviors of heatwave. Results: A total of 911 questionnaires were distributed, and 830 valid questionnaires were recovered, resulting in a valid response rate of 91.11%. Among the respondents, 796 (95.90%) were male, and 818 (98.55%) worked full-time. The mean age was (27.75±8.00) years. A total of 470 respondents (56.63%) had a work tenure of less than 1 year. The primary working hours were 8-<12 hours, with 504 people accounting for 60.72%. There were 108 cases of heatstroke, with an occurrence rate of 13.01%. And 286 people reported heat-related symptoms, with an occurrence rate of 34.46%. The overall awareness rate of heat wave knowledge was 73.22%, while the awareness rate of heat warning signal classification was relatively low at 9.04%. The heat wave cognition score was (5.86±1.31) points. There were statistically significant differences in heat wave cognition scores among food delivery riders of different ages, educational levels, family annual income, work tenures, and work durations (all P<0.05). Regarding positive adaptive behaviors, the number of riders paying attention to weather forecasts and actively learning about preventive measures was higher (734 people each, accounting for 88.43%). Regarding negative adaptive behaviors, the number of riders who often drank ice-cold beverages was higher (509 people, accounting for 61.33%). The heat wave adaptive behavior score was (6.88±1.77) points. There were statistically significant differences in adaptive behavior scores among riders with different educational levels, family annual income, work tenures, and smoking frequency (all P<0.05). Conclusions The occurrence rates of heatstroke and heat-related symptoms among food delivery riders are relatively high. The knowledge awareness and adaptive behaviors regarding heat wave are at a moderate level. It is suggested to strengthen health education, reinforce risk cognition of heat wave, and promote positive adaptive behaviors among food delivery riders.

Background Metals and metalloids in fine particulate matter (PM_2.5) may cause damage to the respiratory and circulatory systems of the human body, and long-term exposure is prone to causing chronic poisoning, cancer, and other adverse effects. Objective To assess the distribution characteristics of metals and metalloids in outdoor PM_2.5 in a southern city of China, conduct source apportionment, and evaluate the associated health risks, thereby providing theoretical support for further pollution control measures. Methods PM_2.5 samples were collected in districts A, B, and C of a southern China city, and the concentrations of 17 metals and metalloids were detected by inductively coupled plasma-mass spectrometry (ICP-MS). Pollution sources were assessed through enrichment factor and principal components analysis, and the main pollution sources were quantified using absolute principal component scores-multivariate linear regression (APCS-MLR). Health risks were evaluated based on the Technical guide for environmental health risk assessment of chemical exposure (WS/T777—2021). Results The ambient air PM_2.5 concentrations in the city were higher in winter and spring, and lower in summer and autumn. The annual average concentrations of ambient PM_2.5 in districts A, B, and C were 36.7, 31.9, and 24.4 μg·m⁻³, respectively. The ambient PM_2.5 levels in districts B and C were below the second-grade limit set by the Ambient air quality standards (GB 3095—2012). The enrichment factors of cadmium (Cd), aluminum (Al), and antimony (Sb) were greater than 10, those of copper (Cu), lead (Pb), arsenic (As), nickel (Ni), mercury (Hg), and molybdenum (Mo) fell between 1 and 10, and those of manganese (Mn), vanadium (V), chromium (Cr), cobalt (Co), barium (Ba), beryllium (Be), and uranium (U) were below or equal to 1. The comprehensive evaluation of source analysis showed that the main pollution sources in districts A and C and the whole city were coal-burning. In district B, the main pollution source was also coal combustion, followed by industrial process sources and dust sources. The carcinogenic risks of As and Cr were between 1×10⁻⁶ and 1×10⁻⁴. However, the hazard quotients for 15 metals and metalloids in terms of non-carcinogenic risk were below 1. Conclusion Cr and As in the atmospheric PM_2.5 of the city present a certain risk of cancer and should be paid attention to. In addition, preventive control measures should be taken against relevant pollution sources such as industrial emission, dust, and coal burning.

Cemental tear is a rare and indetectable condition unless obvious clinical signs present with the involvement of surrounding periodontal and periapical tissues. Due to its clinical manifestations similar to common dental issues, such as vertical root fracture, primary endodontic diseases, and periodontal diseases, as well as the low awareness of cemental tear for clinicians, misdiagnosis often occurs. The critical principle for cemental tear treatment is to remove torn fragments, and overlooking fragments leads to futile therapy, which could deteriorate the conditions of the affected teeth. Therefore, accurate diagnosis and subsequent appropriate interventions are vital for managing cemental tear. Novel diagnostic tools, including cone-beam computed tomography (CBCT), microscopes, and enamel matrix derivatives, have improved early detection and management, enhancing tooth retention. The implementation of standardized diagnostic criteria and treatment protocols, combined with improved clinical awareness among dental professionals, serves to mitigate risks of diagnostic errors and suboptimal therapeutic interventions. This expert consensus reviewed the epidemiology, pathogenesis, potential predisposing factors, clinical manifestations, diagnosis, differential diagnosis, treatment, and prognosis of cemental tear, aiming to provide a clinical guideline and facilitate clinicians to have a better understanding of cemental tear.
Humans ; Dental Cementum/injuries* ; Consensus ; Diagnosis, Differential ; Cone-Beam Computed Tomography ; Tooth Fractures/therapy*

With the growing emphasis on maternal and child oral health, the significance of managing oral health across preconception, pregnancy, and infancy stages has become increasingly apparent. Oral health challenges extend beyond affecting maternal well-being, exerting profound influences on fetal and neonatal oral development as well as immune system maturation. This expert consensus paper, developed using a modified Delphi method, reviews current research and provides recommendations on maternal and child oral health management. It underscores the critical role of comprehensive oral assessments prior to conception, diligent oral health management throughout pregnancy, and meticulous oral hygiene practices during infancy. Effective strategies should be seamlessly integrated across the life course, encompassing preconception oral assessments, systematic dental care during pregnancy, and routine infant oral hygiene. Collaborative efforts among pediatric dentists, maternal and child health workers, and obstetricians are crucial to improving outcomes and fostering clinical research, contributing to evidence-based health management strategies.
Humans ; Pregnancy ; Female ; Infant ; Consensus ; Mouth Diseases/therapy* ; Pregnancy Complications/therapy* ; Oral Health ; Infant, Newborn ; Delphi Technique ; Oral Hygiene

Objective:To discuss the effect of exosomes(Exos)loaded with microRNA-520a-5p(miR-520a-5p)on the pregnancy outcomes in fetal mice with intrauterine growth restriction(FGR),and to clarify its mechanism.Methods:The mouse placental mesenchymal stem cells(MSCs)were cultured in vitro and transfected with miR-520a-5p adenovirus vector(Ad-miR-520a-5p)to obtain the Exos with high miR-520a-5p load(miR-520a-5p-MSCs-Exos),which were then identified.The C57BL/6 mice were mated in cages at a female∶male ratio of 2∶1 to achieve successful pregnancy.Forty pregnant mice were divided into control group,FGR group,NC-MSCs-Exos group,and miR-520a-5p-MSCs-Exos group,with 10 mice in each group.Except for control group,the mice in other groups were exposed to excessive dexamethasone(DEX)during pregnancy to induce FGR models in the pregnant mice.The body weights of the fetal mice at birth and at 1,2,3,and 4 weeks after birth were detected;real-time fluorescence quantitative PCR(RT-qPCR)method was used to detect the expression levels of miR-520a-5p,DNA methyltransferase 3b(DNMT3b),and vascular endothelial growth factor(VEGF)mRNA in placenta tissue of the mice in various groups;Western blotting method was used to detect the expression levels of DNMT3b and VEGF proteins in placenta tissue of the mice in various groups;methylation-specific PCR(MSP)was used to analyze the methylation rates of VEGF promoter in placenta tissue of the mice in various groups;dual-luciferase reporter gene assay was used to verify the targeting relationship between miR-520a-5p and DNMT3b.Results:The results of transmission electron microscope(TEM)and nanoparticle tracking analysis(NTA)showed that the Exos were spherical with particle size concentrated near 100 nm;the Western blotting method results showed that the surface biomarkers CD63 and CD81 of Exos were positively expressed.The RT-qPCR results showed that compared with NC-MSCs-Exos and Ad-NC-MSCs-Exos,the expression level of miR-520a-5p in Ad-miR-520a-5p-MSCs-Exos was increased(P＜0.001).The differences in birth body weight and the body weights at 1,2,and 3 weeks after birth of the fetal mice among four groups were statistically significant(F=36.084,F=19.851,F=77.755,F=103.223;P＜0.001).Compared with control group,the birth body weight and the body weights at 1,2,and 3 weeks after birth of the fetal mice in FGR group were decreased(P＜0.05);compared with FGR group and NC-MSCs-Exos group,the birth body weight and the body weights at 1,2,and 3 weeks after birth of the fetal mice in miR-520a-5p-MSCs-Exos group were increased(P＜0.05).The One-way ANOVA results showed that the differences in the expression levels of miR-520a-5p,DNMT3b,and VEGF mRNA in placenta tissue of the mice among four groups were statistically significant(F=103.224,F=856.460,F=214.563;P＜0.001).The pairwise comparison between groups showed that compared with control group,the expression levels of miR-520a-5p and VEGF mRNA in placenta tissue of the mice in FGR group were decreased(P＜0.05),and the expression level of DNMT3b mRNA was increased(P＜0.05);compared with FGR group and NC-MSCs-Exos group,the expression levels of miR-520a-5p and VEGF mRNA in placenta tissue of the mice in miR-520a-5p-MSCs-Exos group were increased(P＜0.05),and the expression level of DNMT3b mRNA was decreased(P＜0.05).The One-way ANOVA results showed that the differences in the expression levels of DNMT3b and VEGF proteins in placenta tissue of the mice among four groups were statistically significant(F=245.601,F=149.360;P＜0.001).The pairwise comparison between groups showed that compared with control group,the expression level of DNMT3b protein in placenta tissue of the mice in FGR group was increased(P＜0.05),and the expression level of VEGF protein was decreased(P＜0.05);compared with FGR group and NC-MSCs-Exos group,the expression level of DNMT3b protein in placenta tissue of the mice in miR-520a-5p-MSCs-Exos group was decreased(P＜0.05),and the expression level of VEGF protein was increased(P＜0.05).The One-way ANOVA results showed that the difference in the methylation rate of VEGF promoter in placenta tissue of the mice among four groups was statistically significant(F=687.096,P＜0.001).The pairwise comparison between groups showed that compared with control group,the methylation rate of VEGF promoter in placenta tissue of the mice in FGR group was increased(P＜0.05);compared with FGR group and NC-MSCs-Exos group,the methylation rate of VEGF promoter in placenta tissue of the mice in miR-520a-5p-MSCs-Exos group was decreased(P＜0.05).Dual-luciferase reporter gene assay results showed that compared with miR-NC group,the luciferase activity in the cells containing DNMT3b-WT reporter vector in miR-520a-5p group was decreased(P＜0.05);compared with miR-NC group,the luciferase activity in the cells containing DNMT3b-MUT reporter vector in miR-520a-5p group had no change,no significant difference was observed(P＞0.05).Conclusion:The MSCs-derived Exos highly loaded with miR-520a-5p may improve the pregnancy outcomes of FGR fetal mice by targeting and down-regulating the expression of DNMT3b,inhibiting VEGF methylation,and promoting VEGF expression.

Objective To analyze the risk of return to sport in athletes using their gait data following anterior cruciate ligament re-construction(ACLR). Methods From May to June,2023,39 athletes after ACLR were recruited in Wuhan Sports University.Their data on sta-ble gait and tandem gait were recorded using a three-dimensional motion capture system,surface electromyogra-phy and a three-dimensional ergometer table.Additionally,return-to-sport scores were calculated using the K-STARTS test.The relationship between each gait indicator and the total score of the K-STARTS test was ana-lyzed with Pearson correlation analysis.Furthermore,the key indicators related to the risk of return to sport were analyzed using linear regression. Results In the stable gait test,the step time was negatively correlated with the total score of K-STARTS(r=-0.479,P=0.002),and the peak amplitude symmetry index of rectus femoris(r=0.448,P=0.004)and vastus lateralis(r=0.595,P=0.001)were positively correlated with the total score of K-STARTS.In the tandem gait test,the lateral displacement distance of the center of gravity was negatively correlated with the total score of K-STARTS(r=-0.341,P=0.034),and the time symmetry index of peak amplitude of vastus lateralis was positively correlated with the total score of K-STARTS(r=0.320,P=0.047).Regression analysis showed that the interpretation of the model based on stable gait(F=15.818,P=0.001,R2=0.650)was better than that based on tandem gait(F=7.692,P=0.001,R2=0.397). Conclusion In stable gait,gait rhythm variability and symmetry are correlated with return to sport risk.In tandem gait,gait balance and symmetry indexes are correlated with return-to-sport risk.Compared with tandem gait,the inter-pretation of return-to-sport risk assessment model based on stable gait information is better,and may be more suitable as a simple return-to-sport risk test method.

Objective:To investigate the cognition and learning habits of different types of postgraduates and evaluate learning effect and its potential risk factors on clinical epidemiology in a medical college, so as to provide relevant data for improving the teaching method and learning effect of clinical research methods for postgraduates.Methods:A cross-sectional study design was conducted to enroll all the postgraduates of Grade 2020 in a military medical school. A self-filled questionnaire was adopted to collect data. The discrepancy of cognition and learning habits between different types of postgraduates was evaluated by univariate analysis. Discussion was conducted to clarify the potential risk factors of learning effect. t tests or Mann-Whitney U tests were conducted to test the differences between groups for continuous variables. Chi-squared tests or McNemar tests were applied to evaluate the difference between groups for categorical variables. Results:A total of 652 postgraduate students were enrolled for analysis, including 409 master students (62.7) and 243 doctoral students (37.3). The proportion of doctoral students who have heard of clinical epidemiology ( χ2=19.99, P<0.001), who have learned clinical epidemiology ( χ2=9.20, P=0.002), who are interested in ( χ2=11.41, P=0.001) and think the course is important ( χ2=10.71, P=0.001), who previewed before class( χ2=11.21, P=0.001), reviewed after class ( χ2=3.29, P=0.001) and actively discuss in class ( χ2=11.64, P=0.001) is significantly higher than that of master students, the difference was statistically significance. The average score of all the postgraduates was (5.50±1.62) points before teaching and (7.47±1.90) points after teaching, the difference was statistically significant ( t=-23.49, P<0.001). After teaching, the grades of full-time students improved more than that of part-time graduate students, there was statistical significance in the master group ( t=4.41, P<0.001), while not in the doctor group ( t=0.94, P=0.351). Conclusions:The mastery of key points on clinical epidemiology have significantly improved after teaching among the postgraduates of different types. Different teaching methods and processes should be adopted to the variety of postgraduates according to their knowledge foundations and shortcomings. Besides, standardizing their learning habits are of certain significance to improve the learning effect.

ObjectiveTo investigate the effects of Linggui Zhugantang on mitochondrial fission and fusion and silencing information regulator 3（Sirt3）/adenosine monophosphate dependent protein kinase （AMPK） signaling pathway in chronic heart failure （CHF） rats after myocardial infarction （MI）. MethodSD rats randomly divide into sham operation group （normal saline ，thread only without ligature）， model group （normal saline， ligation of the left anterior descending coronary artery proximal to the heart）， Linggui Zhugantang group （4.8 g·kg^-1） and Captopril group （0.002 57 g·kg^-1）， with 10 rats in each group. Administere drug continuously for 28 days. Echocardiography detected cardiac function parameters. Hematoxylin eosin （HE） staining observed the pathological changes of the heart. Immunofluorescence detected the levels of reactive oxygen species （ROS）. JC-1 detect mitochondrial membrane potential. Colorimetry measure adenosine triphosphate （ATP）， superoxide dismutase （SOD）， malondialdehyde （MDA）， mitochondrial respiratory chain complex activity （Ⅰ-Ⅳ）. TdT-mediated dUTP nick end labeling （TUNEL） staining detected the apoptosis rate of myocardial tissue. Western blot detected protein expression levels of Sirt3， phosphorylated AMPK （p-AMPK）， phosphorylated dynamic-related protein 1（p-Drp1）， mitochondrial fission protein 1（Fis1）， mitochondrial fission factor （MFF）， optic atrophy protein 1（OPA1）. ResultCompared to the sham group， the left ventricular end diastolic diameter （LVIDd） and left ventricular end systolic diameter （LVIDs） were significantly increased in model group （P<0.01）， while the left ventricular short axis shortening rate （LVFS） and left ventricular ejection fraction （LVEF） were significantly decreased （P<0.01）. There were inflammatory cell infiltration and obvious pathological injury in myocardial tissue. ROS， MDA levels and myocardial cell apoptosis rate were significantly increased （P<0.01）， SOD level， ATP content， and membrane potential were significantly decreased （P<0.01）. The activity of mitochondrial respiratory chain complexes （Ⅰ-Ⅳ） was significantly decreased （P<0.01）. Levels of p-Drp1， Fis1， MFF proteins were significantly up-regulated （P<0.01）， while Sirt3， p-AMPK， OPA1 proteins level were significantly down-regulated （P<0.01）. Compared with model group， LVIDd and LVIDs were significantly decreased （P<0.01）， LVEF and LVFS were significantly increased （P<0.01）. Inflammatory cell infiltration and pathological damage of myocardial tissue were significantly relieved. ROS， MDA levels and myocardial cell apoptosis rate were significantly decreased in Linggui Zhugantang group and Captopril group （P<0.01）， SOD level， ATP content， and membrane potential significantly increased （P<0.01）. The activity of mitochondrial respiratory chain complexes （Ⅰ-Ⅳ） increased significantly （P<0.01），and p-Drp1， Fis1， MFF protein levels were significantly down-regulated （P<0.01）， Sirt3， p-AMPK， OPA1 protein were significantly up-regulated （P<0.01）. ConclusionLinggui Zhugantang can alleviate oxidative stress and apoptosis damage of myocardial cells， maintain mitochondrial function stability， and its effect may be related to mitochondrial mitosis fusion and Sirt3/AMPK signaling pathway.

ObjectiveTo investigate the levels of serum antibodies against novel coronavirus （SARS-CoV-2） in healthcare workers after one month of natural infection， to explore the influencing factors and their correlations with the levels of antibodies， and to provide reference for strengthening the protection of healthcare workers and preventive intervention in Pudong New Area in Shanghai. MethodsVenous blood samples were collected from 1 102 medical staff in Pudong hospitals one month after infection. The serum levels of new coronavirus specific antibodies IgM， IgG and neutralizing antibodies were detected by chemiluminescent immunoassay. The information of gender， age， position， infection severity， vaccination， basic diseases and use of immunosuppressants were obtained by questionnaire to explore the influencing factors and their correlation with the antibody level. ResultsOne month after natural infection， 99.00% （1 091/1 102） of the subjects were found to be positive for IgG antibody against the new coronavirus， 17.79% （196/1 102） of the subjects were IgM antibody positive， and 99.00% （1 091/1 102） of the samples were positive for the neutralizing antibody. The level of antibody might be influenced by the severity of infection， the time of the last dose of vaccination， and the long-term use of immunosuppressants. The more severe the disease， the stronger the neutralizing antibody response. The antibody level in the people who received the final dose of vaccine within 6 months was higher than that of the people who received the vaccine 6 months ago， and the difference was statistically significant. The antibody levels were low in the subjects who received long-term immunosuppressants. ConclusionThe specific IgM， IgG and neutralizing antibody were found， one month after infection， in the medical workers in Pudong New Area， Shanghai， and the antibody titers were high， which had a good protective effect. The antibody level of the people who were vaccinated within 6 months was higher， it is recommended that people who receive the last vacination more than 6 months should be re-vaccinated with the booster vaccine， to improve the autoimmunity against the novel coronavirus.