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 assess the clinical value of conventional contrast enhanced CT(CECT),multi parameter energy spectrum CT,and contrast enhanced MR(CEMR)imaging methods in evaluating hepatocellular carcinoma(HCC)after TACE treatment.Methods The clinical data of 66 HCC patients,who underwent TACE treatment at authors' hospital and received CECT,multi parameter energy spectrum CT and CEMR in 1-3 months after treatment,were retrospectively analyzed.Taking DSA results as the gold standard,the recurrent or residual lesions detected by DSA were classified as positive lesions,while the lesions having no obvious recurrence or residues were classified as negative lesions.The positive lesions that were detected by both DSA and other imaging methods were regarded as true positive lesions.The accuracy,sensitivity,specificity,Kappa value were used to compare the values of CECT,multi parameter energy spectrum CT and CEMR in evaluating the positive/negative lesions of HCC after TACE treatment,and the number of detected lesions and accuracy rate were used to evaluate the values of the above imaging methods in demonstrating the iodine oil deposition status and in diagnosing true positive lesions.Results A total of 133 positive lesions and 35 negative lesions were detected by DSA.The accuracy of CEMR in diagnosing lesions was highest,the accuracy rate was 88.70％(both P＜0.05);CEMR and energy spectrum CT had the highest diagnostic efficiency,the sensitivity for positive lesions was 92.31％and 81.95％respectively,and the difference between the two methods was not statistically significant(P＞0.05).No statistically significant difference in the ability of diagnosing negative lesions existed between each other among the three groups(all P＞0.05).The Kappa value suggested that the ability for diagnosing lesions after TACE treatment of CEMR was stronger than that of energy spectrum CT(Kappa value was 0.68 and 0.56 respectively,both P＜0.05).CECT and multi parameter energy spectrum CT had the same accuracy in evaluating the iodine oil deposition status(both were 91.7％).No statistically significant difference in diagnosing even iodine oil deposition of the true positive lesions existed between each other among the three groups(all P＞0.05).For diagnosing uneven iodine oil deposition of the true positive lesions,CEMR had the highest accuracy(92.50％,all P＜0.05).Conclusion CEMR and multi parameter energy spectrum CT have more reliable diagnostic performance than conventional CECT,besides,CEMR has the highest diagnostic performance.However,multi parameter energy spectrum CT and CECT are the better choice for evaluating the deposition status of iodine oil.

Objective:To explore the efficacy and safety of endoscopic radial incision (ERI) for congenital membranous duodenal stenosis (MDS).Methods:The clinical data of 13 children with MDS receiving ERI in the Department of Gastroenterology of Xi'an Children's Hospital from May 2017 to December 2021 were reviewed and analyzed. The perioperative management, surgical procedures, postoperative complications and follow-up were summarized.Results:There were 5 boys and 8 girls with a median disease duration of 8 (2-20) months, and the median age of diagnosis was 13 months (5-30 months). The septum of 10 cases (10/13) was located in the descending part of the duodenum, and that of 3 cases (3/13) in the horizontal part. The papilla of 1 case (1/13) opened on the septum, that of 3 cases (3/13) within 5 cm of the mouth side of the septum, and that of 9 cases (9/13) within 5 cm of the anal side of the septum. The median diameter of the septal aperture was 3 mm (2-6 mm). All 13 children successfully underwent ERI with a median operation time of 20 min (15-32 min). The average surgical incision was 3 strokes (2-4 strokes), and the endoscope with outer diameter 9.9 mm could pass stenosis after ERI. The median incision diameter was 10 mm (10-12 mm). All patients achieved relief of clinical symptoms after ERI. One patient (1/13) suffered from the postoperative delayed bleeding, which was stopped by endoscopic titanium clamping. No intestinal perforation or duodenal papilla injury occurred, and median postoperative hospital stay was 6 days (5-10 days). The upper gastrointestinal angiogram and gastroscopy were repeated 3 months after ERI, and the median diameter of stenosis was 12 mm (10-15 mm), which was significantly dilated compared with before. The mean body weight increase at 1 month after ERI was 1.20 kg (0.50-1.80 kg), and the mean body weight increase at 3 months was 3.50 kg (2.50-4.00 kg), which reached the normal body weight of the same age.Conclusion:ERI is safe and effective for the treatment of MDS in children, and shows good clinical application and promotion value.

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.

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:To analyze the growth characteristics of different genotypes of Japanese encephalitis virus (JEV) in different cell lines, and to provide scientific basis for the selection of cell lines in the study of JEV.Methods:BHK-21, Vero, C6/36, PK-15, DF-1, N2a, SH-sy5y and MDCK cell lines were selected. The proliferation ability of genotype 1 (NX1889 strain), genotype 3 (P3 strain) and genotype 5 (XZ0934 strain) JEV in these cell lines was evaluated by plaque assay and RT-qPCR.Results:Significant cytopathogenic effects (CPE) were observed in BHK-21, Vero, C6/36, DF-1, N2a and PK-15 cell lines across all three JEV genotypes. However, no significant differences in CPE characteristics were observed within the same cell line. SH-sy5y and MDCK cell lines did not show significant CPE, but virus proliferation was detected in SH-sy5y cell line, while MDCK cell line were found to be insensitive to JEV. No significant difference was observed in the proliferation curves of G1, G3 and G5 JEV in BHK-21, Vero and SH-sy5y cell lines. In C6/36 and PK-15 cell lines, the titer of G1 JEV was higher than that of G3 and G5. In DF-1 cell line, G5 demonstrated a higher titer than the other two genotypes, whereas in N2a cell line, G5 showed a lower titer than the other two.Conclusions:There are differences in the proliferation of three different genotypes of JEV in different cell lines, which can provide reference for the study of JEV in different directions.

Objective:To elucidate the etiological and epidemiological characteristics and epidemiological patterns of viral acute respiratory infections (ARI) in Shanghai during 2023, with the aim of providing robust laboratory evidence for effective prevention and control strategies against related respiratory diseases and facilitating risk assessment.Methods:Respiratory pathogens were detected in the clinical surveillance specimens submitted by sentinel hospitals through multiplex PCR, as part of the multi-pathogen surveillance of acute respiratory infections in Shanghai during 2023. The obtained detection result were statistically analyzed in conjunction with sample information.Results:The positive detection rate of viral pathogens in 2023 was 21.17% (984/4 648), with rates of 33.53% (504/1 503) observed in ILI cases and 15.62% (480/3 145) in SARI cases. Influenza A virus (FluA) was the predominant virus detected, accounting for 13.7% (637/4 648). Other viruses identified in the surveillance samples included influenza B virus (Flu B), human rhinovirus/enterovirus (HRV/HEV), respiratory syncytial virus (RSV), human metapneumovirus (HMPV), parainfluenza virus (PIV), adenovirus (ADV) and human bocavirus (HBoV). Regarding temporal distribution, HRV/HEV and RSV exhibited the highest detection rates during the second quarter at 2.27% each (28/1 236). PIV had its peak during the third quarter at a rate of 2.49% (35/1 405), and HMPV showed prevalence mainly during the third and fourth quarters, with detection rates of 2.63% (37/1 405) and 2.35% (32/1 360), respectively.Conclusions:In acute respiratory infection surveillance cases in Shanghai in 2023, Flu A emerged as the predominant respiratory pathogen. The detection rate of HMPV ranked second only to Flu A, while other respiratory viruses such as HRV/HEV, RSV, and PIV were detected during different seasons and co-circulated. The prevalence of various respiratory viruses varied among different infected populations and over times.

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.