Objective: To prepare an inactivated hepatitis A vaccine using a attenuated strain of hepatitis A virus (HAV) H2 and to analyze its immunizing dose, so as to provide the reference for development and production of inactivated hepatitis A vaccines. Methods: Human embryonic lung diploid cells (KMB17) were infected with attenuated HAV H2 strain to proliferate the virus, then the cells containing viruses were harvested, extracted and purified. The obtained virus concentrate was prepared into vaccine bulk and test vaccines with 1 280 EU/mL antigen content. Vaccine testing was carried out according to the inactivated hepatitis A vaccine standards specified in the Part Ⅲ of the Pharmacopoeia of the People's Republic of China (2020 edition). A total of 110 mice were randomly divided into 11 groups, including 5 dose groups (80, 160, 320, 640 and 1 280 EU/dose) of the test vaccine and the reference vaccine, as well as the adjuvant control group. Mice were immunized twice by intraperitoneal injection, their serum HAV antibodies were detected, and the geometric mean titer (GMT) and positive conversion rate of antibodies were analyzed to evaluate the immunising dose of the vaccine. Results: The antigen content and viral titer of the virus harvest solution were 5 120 EU/mL and 8.33 lgCCID50/mL, respectively. The removal rate of foreign protein reached 98.05% and the recovery rate of antigen was 66.25%. The test vaccine met the requirements of Part Ⅲ of the Pharmacopoeia of the People's Republic of China (2020 edition). The GMTs of HAV antibodies in the test vaccine and the reference vaccine dose groups after the second immunization were more than twice higher than those after the first immunization. Regardless of primary immunization or secondary immunization, the GMTs (log2) of HAV antibodies in the test vaccine groups with doses of 160 EU/dose and above were higher than those in the 80 EU/dose group (all P<0.05), while there was no statistically significant differences between the dose groups of 160 EU/dose and above (all P>0.05). The antibody positive conversion rate of 160 EU/dose and above of the test vaccine was 100.00% after the secondary immunization. Conclusions The inactivated hepatitis A vaccine of attenuated H2 strain tested in this study demonstrates strong immunogenicity in mice, suggesting its potential as a candidate vaccine. The preliminary analysis indicates an immunizing dose of 320 EU/dose for children and 640 EU/dose for adults.

Objective To develop an intelligent model for differential diagnosis of atrioventricular nodal re-entrant tachycardia(AVNRT)and atrioventricular re-entrant tachycardia(AVRT)using 12-lead wearable electrocardiogram devices.Methods A total of 356 samples of 12-lead supraventricular tachycardia(SVT)electrocardiograms recorded by wearable devices were randomly divided into training and validation sets using 5-fold cross validation to establish the intelligent classification model,and 101 patients with the diagnosis of SVT undergoing electrophysiological studies and radiofrequency ablation from October,2021 to March,2023 were selected as the testing set.The changes in electrocardiogram parameters before and during induced tachycardia were compared.Based on multiscale deep neural network,an intelligent diagnosis model for classifying SVT mechanisms was constructed and validated.The 3-lead electrocardiogram signals from Ⅱ,Ⅲ,and V1 were extracted to build new classification models,whose diagnostic efficacy was compared with that of the 12-lead model.Results Of the 101 patients with SVT in the testing set,68 were diagnosed with AVNRT and 33 were diagnosed with AVRT by electrophysiological study.The pre-trained model achieved a high area under the precision-recall curve(0.9492)and F1 score(0.8195)for identifying AVNRT in the validation set.The total F1 scores of the lead Ⅱ,Ⅲ,V1,3-lead and 12-lead intelligent diagnostic models in the testing set were 0.5597,0.6061,0.3419,0.6003 and 0.6136,respectively.Compared with the 12-lead classification model,the lead-Ⅲ model had a net reclassification index improvement of-0.029(P=0.878)and an integrated discrimination index improvement of-0.005(P=0.965).Conclusion The intelligent diagnostic model based on multiscale deep neural network using wearable electrocardiogram devices has an acceptable accuracy for classifying SVT mechanisms.

Objective To develop an intelligent model for differential diagnosis of atrioventricular nodal re-entrant tachycardia(AVNRT)and atrioventricular re-entrant tachycardia(AVRT)using 12-lead wearable electrocardiogram devices.Methods A total of 356 samples of 12-lead supraventricular tachycardia(SVT)electrocardiograms recorded by wearable devices were randomly divided into training and validation sets using 5-fold cross validation to establish the intelligent classification model,and 101 patients with the diagnosis of SVT undergoing electrophysiological studies and radiofrequency ablation from October,2021 to March,2023 were selected as the testing set.The changes in electrocardiogram parameters before and during induced tachycardia were compared.Based on multiscale deep neural network,an intelligent diagnosis model for classifying SVT mechanisms was constructed and validated.The 3-lead electrocardiogram signals from Ⅱ,Ⅲ,and V1 were extracted to build new classification models,whose diagnostic efficacy was compared with that of the 12-lead model.Results Of the 101 patients with SVT in the testing set,68 were diagnosed with AVNRT and 33 were diagnosed with AVRT by electrophysiological study.The pre-trained model achieved a high area under the precision-recall curve(0.9492)and F1 score(0.8195)for identifying AVNRT in the validation set.The total F1 scores of the lead Ⅱ,Ⅲ,V1,3-lead and 12-lead intelligent diagnostic models in the testing set were 0.5597,0.6061,0.3419,0.6003 and 0.6136,respectively.Compared with the 12-lead classification model,the lead-Ⅲ model had a net reclassification index improvement of-0.029(P=0.878)and an integrated discrimination index improvement of-0.005(P=0.965).Conclusion The intelligent diagnostic model based on multiscale deep neural network using wearable electrocardiogram devices has an acceptable accuracy for classifying SVT mechanisms.

Clinical research reports serve as the presentation of scientific research findings and directly reflect the quality of the research. This article describes the writing of different types of clinical research reports， such as observational studies and randomized controlled trial studies， with a particular focus on randomized controlled trials. Each scientific research design has its reporting focus， and the writing of scientific research papers has uniform requirements and a specific writing format. Mastering the proper format of drafting research reports is of practical value and significant importance for conduction high-quality clinical research.

Objective:To explore the interleukin-31 protein expression in the hypertrophic scar of incision tissue after surgery and its underlying pathological impact.Methods:From February 2022 to February 2023, three HS patients scar tissue (HS) and their normal skin tissue (Control, NS) were obtained. Two patients were female and one patient was male. The tissues were fixed in 4% formalin and embedded in paraffin. Haematoxylin-eosin (HE) stain and immunohistochemical stain were used to evaluate the epidermal thickness, myofibroblasts of dermis and the expression level of IL-31 between HS and NS.Results:The epidermis thickness was (303.88±46.03) μm in HS group, while (133.02±17.40) μm in NS group ( t=12.60, P<0.001). The expression level of IL-31 protein was measured by IRS score and positive cell density. The IRS score was 9.89±2.03 of the basal layer in HS group and was 4.33±1.66 of the basal layer in NS group. The positive cell density was 786 343.83±159 627.97 of the basal layer in HS group ( P<0.001) and was 555 457.61±128 097.21 of the basal layer in NS group ( P=0.014). In the dermis layer, the IRS score was 7.11±1.05 in HS group and was 4.33±0.71 in NS group, the positive cell density was 156 760.97±26 046.10 in HS group ( P<0.001) and was 49 576.01±52 369.33 in NS group ( P<0.001). In the dermis layer, the count of myofibroblasts was 120.44±15.75 in HS group while was 27.39±14.89 in NS group ( t=23.79, P<0.001). Conclusions:Our study demonstrates that both myofibroblast count and IL-31 protein expression level are notably increased in HS patients. The expression of IL-31 protein is prominent in the cytoplasm of myofibroblasts, basal cells, macrophages and mast cells which could implicate that IL-31 may be a potential therapeutic target to enhance the resolution of HS.

Statistics plays an important role in medical research， and the selection of appropriate statistical methods is crucial for drawing reliable and valuable conclusions. This paper provides a brief introduction to commonly used statistical analysis methods for medical data， covering descriptive analysis， parametric test， nonparametric test， correlation analysis， regression analysis， and analysis of survival data. It focuses on discussing the assumptions of multiple linear regression， logistic regression and Cox proportional risk regression， as well as how to choose the appropriate statistical methods for analyzing and interpreting medical data based on different research objectives and data types.

Macrophages are important cell types involved in skin wound healing. In this article, recent advances in macrophage-mediated regulation of skin wound healing and the abnormal polarization of macrophages in diabetic refractory wounds are reviewed. Studies have shown that macrophages in skin wounds can be categorized into two types, M1 and M2. These two types exhibit different functions, including anti-inflammatory effects, angiogenesis promotion, fibroblast promotion and tissue shaping. The dysfunctions of macrophages, cytokine secretion and epigenetic modifications in diabetes mellitus can lead to abnormal polarization of macrophages. Targeting the regulation of macrophage polarization may be an effective approach to addressing skin refractory wounds.

Macrophages are important cell types involved in skin wound healing. In this article, recent advances in macrophage-mediated regulation of skin wound healing and the abnormal polarization of macrophages in diabetic refractory wounds are reviewed. Studies have shown that macrophages in skin wounds can be categorized into two types, M1 and M2. These two types exhibit different functions, including anti-inflammatory effects, angiogenesis promotion, fibroblast promotion and tissue shaping. The dysfunctions of macrophages, cytokine secretion and epigenetic modifications in diabetes mellitus can lead to abnormal polarization of macrophages. Targeting the regulation of macrophage polarization may be an effective approach to addressing skin refractory wounds.

BACKGROUND: As a contour-supporting material, the cartilage has a significant application value in plastic surgery.Since the development of hydrogel scaffolds with sufficient biomechanical strength and high biocompatibility, cell-laden hydrogels have been widely studied for application in cartilage bioengineering. This systematic review summarizes the latest research on engineered cartilage constructed using cell-laden hydrogel scaffolds in plastic surgery. METHODS: A systematic review was performed by searching the PubMed and Web of Science databases using selected keywords and Medical Subject Headings search terms. RESULTS: Forty-two studies were identified based on the search criteria. After full-text screening for inclusion and exclusion criteria, 18 studies were included. Data collected from each study included culturing form, seed cell types and sources, concentration of cells and gels, scaffold materials and bio-printing structures, and biomechanical properties of cartilage constructs. These cell-laden hydrogel scaffolds were reported to show some feasibility of cartilage engineering, including better cell proliferation, enhanced deposition of glycosaminoglycans and collagen type II in the extracellular matrix, and better biomechanical properties close to the natural state. CONCLUSION Cell-laden hydrogels have been widely used in cartilage bioengineering research. Through 3-dimensional (3D) printing, the cell-laden hydrogel can form a bionic contour structure. Extracellular matrix expression was observed in vivo and in vitro, and the elastic modulus was reported to be similar to that of natural cartilage. The future direction of cartilage tissue engineering in plastic surgery involves the use of novel hydrogel materials and more advanced 3D printing technology combined with biochemistry and biomechanical stimulation.

ObjectiveTo investigate epidemiological characteristics and influencing factors of non-suicidal self-injury （NSSI） behaviors among middle school students in Jiangmen. MethodsA total of 1 220 middle school students in Jiangmen were selected for the study through stratified random sampling from November to December 2020. The self-compiled general demographic questionnaire， Coping Style Scale for Middle School Students， Olweus Bully/Victim Questionnaire （BVQ）， Social Support Scale for Adolescents， and Center for Epidemiologic Studies-Depression Scale （CES-D） were used for the assessment. Then binary Logistic regression analysis was performed to screen the factors influencing NSSI behaviors in students. ResultsA total of 204 middle school students （16.72%） were found to be engaged in NSSI behaviors， of whom 67 were male and 137 were female. There were statistically significant differences between the NSSI group and the non-NSSI group in terms of gender， school period， lodging， peer relationship and academic performance （χ²=22.162， 7.247， 6.541， 45.787， 25.097， P<0.05 or 0.01）. Compared with the non-NSSI group， the NSSI group scored higher on CES-D （t=-14.240） and BVQ （t=-5.952）， lower on Social Support Scale for Adolescents （t=9.238）. Within the Coping Style Scale for Middle School Students， NSSI group had lower problem-focused coping score （t=7.148） and higher emotion-focused coping score （t=-7.038） than those of non-NSSI group. The detection rates of school bullying， verbal and relational bullying were higher in NSSI group compared with non-NSSI group （χ²=34.215， 29.785，16.465）. The differences were statistically significant （P<0.01）. Binary Logistic regression showed that depression （OR=1.090， P<0.01） and school bullying （OR=1.492， P<0.05） entered into the regression model. ConclusionThe situation of NSSI behaviors of middle school students in Jiangmen is serious， and depression and school bullying are risk factors affecting NSSI behaviors in students.