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:In chronic hepatitis B (CHB) patients with previous 96-week treatment with tenofovir amibufenamide (TMF) or tenofovir disoproxil fumarate (TDF), we investigated the efficacy of sequential TMF treatment from 96 to 144 weeks.Methods:Enrolled subjects who were previously assigned (2:1) to receive either 25 mg TMF or 300 mg TDF with matching placebo for 96 weeks received extended or switched TMF treatment for 48 weeks. Efficacy was evaluated based on virological, serological, biological parameters, and fibrosis staging. Statistical analysis was performed using the McNemar test, t-test, or Log-Rank test according to the data. Results:593 subjects from the initial TMF group and 287 subjects from the TDF group were included at week 144, with the proportions of HBV DNA<20 IU/ml at week 144 being 86.2% and 83.3%, respectively, and 78.1% and 73.8% in patients with baseline HBV DNA levels ≥8 log10 IU/ml. Resistance to tenofovir was not detected in both groups. For HBeAg loss and seroconversion rates, both groups showed a further increase from week 96 to 144 and the 3-year cumulative rates of HBeAg loss were about 35% in each group. However, HBsAg levels were less affected during 96 to 144 weeks. For patients switched from TDF to TMF, a substantial further increase in the alanine aminotransferase (ALT) normalization rate was observed (11.4%), along with improved FIB-4 scores.Conclusion:After 144 weeks of TMF treatment, CHB patients achieved high rates of virological, serological, and biochemical responses, as well as improved liver fibrosis outcomes. Also, switching to TMF resulted in significant benefits in ALT normalization rates (NCT03903796).

Objective:In chronic hepatitis B (CHB) patients with previous 96-week treatment with tenofovir amibufenamide (TMF) or tenofovir disoproxil fumarate (TDF), we investigated the safety profile of sequential TMF treatment from 96 to 144 weeks.Methods:Enrolled subjects that previously assigned (2:1) to receive either 25 mg TMF or 300 mg TDF with matching placebo for 96 weeks received extending or switching TMF treatment for 48 weeks. Safety profiles of kidney, bone, metabolism, body weight, and others were evaluated.Results:666 subjects from the initial TMF group and 336 subjects from TDF group with at least one dose of assigned treatment were included at week 144. The overall safety profile was favorable in each group and generally similar between extended or switched TMF treatments from week 96 to 144. In subjects switching from TDF to TMF, the non-indexed estimated glomerular filtration rate (by non-indexed CKD-EPI formula) and creatinine clearance (by Cockcroft-Gault formula) were both increased, which were (2.31±8.33) ml/min and (4.24±13.94) ml/min, respectively. These changes were also higher than those in subjects with extending TMF treatment [(0.91±8.06) ml/min and (1.30±13.94) ml/min]. Meanwhile, switching to TMF also led to an increase of the bone mineral density (BMD) by 0.75% in hip and 1.41% in spine. On the other side, a slight change in TC/HDL ratio by 0.16 (IQR: 0.00, 0.43) and an increase in body mass index (BMI) by (0.54±0.98) kg/m 2 were oberved with patients switched to TMF, which were significantly higher than that in TMF group. Conclusion:CHB patients receiving 144 weeks of TMF treatment showed favorable safety profile. After switching to TMF, the bone and renal safety was significantly improved in TDF group, though experienceing change in metabolic parameters and weight gain (NCT03903796).

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 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.