ObjectiveTo understand the seropositivity of neutralizing antibodies (NAb) and low-level NAb against SARS-CoV-2 infection in the community residents, and to explore the impact of COVID-19 vaccination and SARS-CoV-2 infection on the levels of NAb in human serum. MethodsOn the ground of surveillance cohort for acute infectious diseases in community populations in Shanghai, a proportional stratified sampling method was used to enroll the subjects at a 20% proportion for each age group (0‒14, 15‒24, 25‒59, and ≥60 years old). Blood samples collection and serum SARS-CoV-2 NAb concentration testing were conducted from March to April 2023. Low-level NAb were defined as below the 25^th percentile of NAb. ResultsA total of 2 230 participants were included, the positive rate of NAb was 97.58%, and the proportion of low-level NAb was 25.02% (558/2 230). Multivariate logistic regression analysis indicated that age, infection history and vaccination status were correlated with low-level NAb (all P<0.05). Individuals aged 60 years and above had the highest risk of low-level NAb. There was a statistically significant interaction between booster vaccination and one single infection (aOR=0.38, 95%CI: 0.19‒0.77). Compared to individuals without vaccination, among individuals infected with SARS-CoV-2 once, both primary immunization (aOR=0.23, 95%CI: 0.16‒0.35) and booster immunization (aOR=0.12, 95%CI: 0.08‒0.17) significantly reduced the risk of low-level NAb; among individuals without infections, only booster immunization (aOR=0.28, 95%CI: 0.14‒0.52) showed a negative correlation with the risk of low-level NAb. ConclusionsThe population aged 60 and above had the highest risk of low-level NAb. Regardless of infection history, a booster immunization could reduce the risk of low-level NAb. It is recommended that eligible individuals , especially the elderly, should get vaccinated in a timely manner to exert the protective role of NAb.

OBJECTIVES: We propose a new melanoma segmentation model, SG-UNet, to enhance the precision of melanoma segmentation in dermascopy images to facilitate early melanoma detection. METHODS: We utilized a U-shaped convolutional neural network, UNet, and made improvements to its backbone, skip connections, and downsampling pooling sections. In the backbone, with reference to the structure of VGG, we increased the number of convolutions from 10 to 13 in the downsampling part of UNet to achieve a deepened network hierarchy that allowed capture of more refined feature representations. To further enhance feature extraction and detail recognition, we replaced the traditional convolution the backbone section with self-calibrated convolution to enhance the model's ability to capture both spatial and channel dimensional features. In the pooling part, the original pooling layer was replaced by Haar wavelet downsampling to achieve more effective multi-scale feature fusion and reduce the spatial resolution of the feature map. The global attention mechanism was then incorporated into the skip connections at each layer to enhance the understanding of contextual information of the image. RESULTS: The experimental results showed that the SG-UNet model achieved significantly improved segmentation accuracy on ISIC 2017 and ISIC 2018 datasets as compared with other current state-of-the-art segmentation models, with Dice reached 92.41% and 86.62% and IoU reaching 92.31% and 86.48% on the two datasets, respectively. CONCLUSIONS The proposed model is capable of effective and accurate segmentation of melanoma from dermoscopy images.
Melanoma/diagnosis* ; Humans ; Neural Networks, Computer ; Dermoscopy/methods* ; Skin Neoplasms ; Image Processing, Computer-Assisted/methods* ; Calibration ; Algorithms

Objective To clarify the influencing factors of defensive medicine and provide ideas for preventing and re-solving defensive medicine.Methods Literature related to defensive medicine was searched,personnel related to de-fensive medicine were interviewed,and literature and interview data were coded with the method of grounded theo-ry,and related concepts and categories were summarized.Results After three levels of coding,52 initial concepts,23 initial categories,7 sub-categories and 3 main categories were sorted out,and the correlation among influencing factors was analyzed to build a three-dimensional model of"doctor-patient relationship-institutional system-social environment"influencing factors and their mechanism of action.Conclusion The influencing factors of defensive medi-cine mainly include doctor-patient relationship,institutional system and social environment.The three factors have an impact on defensive medicine through different mechanisms of action,which provides qualitative evidence for comprehensive analysis of factors in related studies of defensive medicine.

Objective To understand the status of behavioral intentions of defensive medical treatment in medical students,and explore the relationship between practice environment and behavioral intentions of defensive medical treatment.To provide reference for reducing the tendency of defensive medicine(DM)behavior of medical students and improving the negative effects of DM.Methods A web-based questionnaire survey was conducted among medi-cal students in four medical colleges in Heilongjiang Province.The structural equation modeling of the relationship be-tween practice environment and behavioral intentions of defensive medical treatment in medical students was con-structed by Amos 26.0 software.Results The mean score of medical students'behavioral intentions of positive and negarive defensive medical treatment was 44.49-6.90 and 20.06-6.83,respectively.The behavioral intention of posi-tively defensive medical treatment was positively associated(β=0.892,P＜0.05)with cognition of doctor-patient relationship.While the behavioral intention of negative defensive medical treatment was positively correlated(β=0.403,0.343,P＜0.05)with environment cognition,perception of risk and negatively correlated(β=-0.726,P＜0.05)with cognition of doctor-patient relationship.As an intermediary variable,the direct and indirect effects of cog-nition of doctor-patient relationship on negative defensive medical behavior tendency were-0.470 and 0.043,the difference was statistically significant(P＜0.05).Conclusion Improving cognition of medical students'doctor-pa-tient relationship is beneficial to understand defensive medical treatment for medical students.The negative defen-sive medical behavior tendency of medical students should be reduced by reducing their negative cognition of environ-ment or improving their cognition of doctor-patient relationship.

Objective Genotypes(G)1,3,and 5 of the Japanese encephalitis virus(JEV)have been isolated in China,but the dominant genotype circulating in Chinese coastal areas remains unknown.We searched for G5 JEV-infected cases and attempted to elucidate which JEV genotype was most closely related to human Japanese encephalitis(JE)in the coastal provinces of China. Methods In this study,we collected serum specimens from patients with JE in three coastal provinces of China(Guangdong,Zhejiang,and Shandong)from 2018 to 2020 and conducted JEV cross-neutralization tests against G1,G3,and G5. Results Acute serum specimens from clinically reported JE cases were obtained for laboratory confirmation from hospitals in Shandong(92 patients),Zhejiang(192 patients),and Guangdong(77 patients),China,from 2018 to 2020.Seventy of the 361 serum specimens were laboratory-confirmed to be infected with JEV.Two cases were confirmed to be infected with G1 JEV,32 with G3 JEV,and two with G5 JEV. Conclusion G3 was the primary infection genotype among JE cases with a definite infection genotype,and the infection caused by G5 JEV was confirmed serologically in China.

OBJECTIVE To investigate the effect and mechanism of picroside Ⅱ on the malignant progression of non-small cell lung cancer （NSCLC）. METHODS A549 cells were divided into the control group， picroside Ⅱ low-， medium- and high- concentration groups， K6PC-5 [sphingosine kinase 1 （SPHK1） activator] group， and picroside Ⅱ high-dose+K6PC-5 group. Cell proliferation， migration and invasion were detected. Besides， the expression of proliferating cell nuclear antigen （PCNA）， matrix metalloproteinase-2 （MMP-2）， MMP-9， SPHK1， sphingosine-1-phosphate receptor 3 （S1PR3） and extracellular signal-regulated kinase 1/2 （ERK1/2） protein in the cells were also observed. BALB/c nude mice were subcutaneously inoculated with A549 cell suspension to establish NSCLC xenograft models. Then they were assigned to the nude mouse-control group， nude mouse-picroside Ⅱ low-， medium- and high-dose groups， nude mouse-K6PC-5 group， and nude mouse-picroside Ⅱ high-dose+K6PC-5 group （with 5 mice in each group） to investigate the effect of picroside Ⅱ on their tumor mass and volume. RESULTS Compared with the control group， the OD450 values， EdU-positive cell rates， scratch healing rates， cell invasion number， and the relative expression levels of PCNA， MMP-2， MMP-9， SPHK1， S1PR3 and ERK1/2 protein in the low-， medium- and high-concentration groups of picroside Ⅱ were significantly decreased. Compared with the nude mouse-control group， the tumor mass and volume in the nude mouse-low-， medium- and high-dose groups of picroside Ⅱ were significantly decreased or shrunk. The changes of above indicators were concentration/dose-dependent （P＜0.05）. The changing trend of the corresponding indicators in the K6PC-5 ZYTS181） group and the nude mouse-K6PC-5 group was opposite （P＜0.05）. Compared with the picroside Ⅱ high-concentration group or the nude mice-picroside Ⅱ high-dose group， the above quantitative indicators in the picroside Ⅱ high- concentration+K6PC-5 group cells and the nude mouse-picroside Ⅱ high-dose+K6PC-5 group nude mice were significantly increased or enlarged （P＜0.05）. CONCLUSIONS Picroside Ⅱ may inhibit the malignant progression of NSCLC by inhibiting SPHK1/sphingosine-1-phosphate/S1PR3 signaling pathway.

The West Nile virus (WNV), a mosquito-borne arbovirus, is also a zoonotic pathogen first isolated in the 1930s in Africa, followed by the identification of the prevalence of febrile illness caused by West Nile virus infections. In 1999, the West Nile virus was first introduced into New York City of the United States, and caused the outbreak of viral encephalitis in adults. This marked the first reported outbreak of mass adult viral encephalitis caused by West Nile virus. Subsequently, West Nile virus and its infections in humans and animals spread rapidly throughout the United States, causing a worldwide sensation. West Nile virus is currently considered the most widely distributed emerging mosquito-borne arboviruses worldwide. Humans or animals infected by mosquito bites can develop symptoms such as fever, encephalitis (meningitis), and in rare cases, present with severe pancreatitis, hepatitis, myocarditis, miscarriage, or even death, posing a huge global public health burden. This review introduces China's progress in the isolation and identification of West Nile virus, the prevalence of adult viral encephalitis, and the field surveys and laboratory investigations of the coinfection of West Nile virus and typhoid bacteria, aiming to promote the research work and control and prevention of West Nile virus and its infection in China.

Objective To investigate the prevalence of parasitic infections in market-sold aquatic products in Shanghai Municipality, and to understand the knowledge and practice towards food-borne parasitic diseases among residents, so as to provide insights into the surveillance and control of food-borne parasitic diseases. Methods Freshwater products, seawater products and pickled products were randomly obtained from agricultural trade markets, supermarkets, retail stores and restaurants in Huangpu, Putuo, Minhang and Qingpu districts of Shanghai Municipality from 2020 to 2023. Parasite metacercariae and larvae were detected in these aquatic products using pressing method, digestion method and the dissection method, and the detection of parasitic infection was compared in different types of aquatic products. In addition, the knowledge and practice towards food-borne parasitic diseases were investigated among residents aged 10-80 years old who randomly selected from agricultural trade markets, supermarkets, community streets and other population concentration areas in these four districts by questionnaire in 2023, and the awareness of food-borne parasitic diseases knowledge and percentage of healthy behaviors formation were analyzed. Results A total of 2 109 aquatic products sampled from Huangpu, Putuo, Minhang and Qingpu districts of Shanghai Municipality from 2020 to 2023 were detected, and there were 317 products detected with parasitic infections, with an overall detection rate of 15.03%. There were 8 products detected with parasitic infections in 1 221 freshwater products, with a detection rate of 0.66%, and Clonorchis sinensis was the predominant parasite, which was detected in Pseudorasbora parva, Rhodeus amarus and Carassius auratus. There were 82 products detected with parasitic infections in 501 seawater products, with a detection rate of 16.37%, and Anisakis was the predominant parasite, which was detected in Trichiurus lepturus, Larimichthys polyactis, Pneumatophorus japonicus, Collchthys lucidus, Mugil cephalus, Larimichthys crocea, Scomberomorus niphonius, Stromateoides argenteus and Cololabis saira. There were 227 products detected with parasitic infections in 387 pickled products, with a detection rate of 58.66%, and the prevalence rates of Echinostoma metacercariae were 76.27% (225/295) in Bullacta exarata and 11.11% (2/18) in crab pastes, respectively (χ² = 159.511, P < 0.05). No Paragonimus infection was found in freshwater shrimps, crabs and pickled products, and no Diphyllobothrium latum larvae infection was detected in freshwater and seawater fish. Questionnaire surveys showed that the awareness of food-borne parasitic diseases knowledge was 79.00% (222/281), and the percentages of washing hands before and after meals, not drinking filtered water or tap water directly, not eating raw or semi-raw food, being willing to change special dietary preferences or bad living habits for health, and being willing to learn more about food-borne parasitic diseases knowledge were 99.64% (280/281), 72.24% (203/281), 56.23% (158/281), 96.80% (272/281) and 97.51% (274/281) among residents living in Huangpu, Putuo, Minhang and Qingpu districts, respectively. Conclusions There are food-borne parasite contaminations in market-sold aquatic products in Shanghai Municipality. Although residents are aware of food-borne parasitic diseases knowledge, sustainable surveillance of food-borne parasitic diseases and improved health education are required to minimize the risk of human parasitic infections.

Objective To clarify the influencing factors of defensive medicine and provide ideas for preventing and re-solving defensive medicine.Methods Literature related to defensive medicine was searched,personnel related to de-fensive medicine were interviewed,and literature and interview data were coded with the method of grounded theo-ry,and related concepts and categories were summarized.Results After three levels of coding,52 initial concepts,23 initial categories,7 sub-categories and 3 main categories were sorted out,and the correlation among influencing factors was analyzed to build a three-dimensional model of"doctor-patient relationship-institutional system-social environment"influencing factors and their mechanism of action.Conclusion The influencing factors of defensive medi-cine mainly include doctor-patient relationship,institutional system and social environment.The three factors have an impact on defensive medicine through different mechanisms of action,which provides qualitative evidence for comprehensive analysis of factors in related studies of defensive medicine.

Objective To understand the status of behavioral intentions of defensive medical treatment in medical students,and explore the relationship between practice environment and behavioral intentions of defensive medical treatment.To provide reference for reducing the tendency of defensive medicine(DM)behavior of medical students and improving the negative effects of DM.Methods A web-based questionnaire survey was conducted among medi-cal students in four medical colleges in Heilongjiang Province.The structural equation modeling of the relationship be-tween practice environment and behavioral intentions of defensive medical treatment in medical students was con-structed by Amos 26.0 software.Results The mean score of medical students'behavioral intentions of positive and negarive defensive medical treatment was 44.49-6.90 and 20.06-6.83,respectively.The behavioral intention of posi-tively defensive medical treatment was positively associated(β=0.892,P＜0.05)with cognition of doctor-patient relationship.While the behavioral intention of negative defensive medical treatment was positively correlated(β=0.403,0.343,P＜0.05)with environment cognition,perception of risk and negatively correlated(β=-0.726,P＜0.05)with cognition of doctor-patient relationship.As an intermediary variable,the direct and indirect effects of cog-nition of doctor-patient relationship on negative defensive medical behavior tendency were-0.470 and 0.043,the difference was statistically significant(P＜0.05).Conclusion Improving cognition of medical students'doctor-pa-tient relationship is beneficial to understand defensive medical treatment for medical students.The negative defen-sive medical behavior tendency of medical students should be reduced by reducing their negative cognition of environ-ment or improving their cognition of doctor-patient relationship.