African swine fever(ASF)is an acute and highly pathogenic hemorrhagic disease of pigs,causing huge economic losses to pig industry.In order to quantitatively detect clinical samples of ASF and inactivated ASFV antigens,the IgG of ASF positive serum was used as capture anti-body and the HRP-labeled p72 monoclonal antibody was used as detecting antibody.The standard curve was drawn with the cell-cultured ASFV,and a sandwich ELISA detection of antigen was es-tablished.The specificity,sensitivity and stability of the method were evaluated.The effects of dif-ferent inactivation methods and adjuvant addition on antigen detection were further evaluated.The results showed that the minimum detection limits of the recombinant protein and the ASFV were 0.1 mg/L and 103.7 TCID50/mL,respectively.There was no cross-reaction with five common porcine pathogenic viruses,and the coefficient variations between batches was less than 10％.The total co-incidence rate with real-time fluorescence quantitative PCR was 92％(23/25).The sensitivity of antigen detection was significantly reduced when antigen was treated by BEI inactivation,and the detection results were severely interfered by aluminum adjuvant and nano-adjuvant.In summary,the sandwich ELISA antigen detection method established is specific,sensitive,and repeatable,with a good consistency to the qPCR method,which provides an effective clinical diagnostic meth-od for ASFV antigen.

Medical image is a powerful tool to assist doctors in the diagnosis and treatment planning.Nowadays,the segmentation of medical images is no longer limited to manual segmentation methods.Traditional methods and deep learning methods have been used to achieve more accurate results in medical image segmentation.Herein some innovative medical image segmentation methods in recent years are reviewed.By elaborating on the innovations of deep learning methods(SAM,SegNet,Mask R-CNN,and U-NET)and traditional methods(active contour model and threshold segmentation model),the differences and similarities between them are compared.The summary of medical image segmentation methods and the prospect is expected to help researchers better grasp and familiarize themselves with research status and development trend.

BACKGROUND:Mesenchymal stem cell-derived exosomes may play a crucial role in tissue damage repair,and miRNA is an important component of exosomes for therapeutic effects.Among them,miR-29b-3p has the effect of reducing cell apoptosis,promoting axonal regeneration,and angiogenesis. OBJECTIVE:To study the protective effect of adipose-derived mesenchymal stem cell-derived exosome via miR-29b-3p on a neural cell injury model simulated by H2O2-treated PC12 cells,and explore the relevant mechanisms. METHODS:(1)First,the collagenase digestion method was used to extract rat adipose-derived mesenchymal stem cells.Adipose-derived mesenchymal stem cells were transfected with miR-29b-3p mimics and inhibitors.Exosomes were extracted from the culture supernatant by ultracentrifugation and identified so as to construct adipose-derived mesenchymal stem cell-derived exosomes with high expression and knockdown miR-29b-3p.(2)By constructing a neural cell injury model simulated by PC12 cells treated with H2O2,the relevant mechanisms of the protective effect of adipose-derived mesenchymal stem cell-derived exosome via miR-29b-3p on the simulated neuronal cell injury model were studied. RESULTS AND CONCLUSION:(1)Adipose-derived mesenchymal stem cell-derived exosome had a typical cup-shaped shape and a diameter distribution in the range of 50-140 nm,expressed membrane proteins Alix,CD63,and TSG101,which were specific markers on the surface of exosomes,and could be successfully ingested by PC12 cells.(2)Adipose-derived mesenchymal stem cell-derived exosome pretreatment could reduce cell apoptosis induced by H2O2 treatment in PC12 cells,and this protective effect was enhanced with the increase of miR-29b-3p expression in the exosomes and weakened with the decrease of miR-29b-3p expression in the exosomes.The mechanism of its effect was related to adipose-derived mesenchymal stem cell-derived exosome via miR-29b-3p promoting the expression of anti-apoptotic protein Bcl-2 and inhibiting the expression of apoptotic protein Bax.

Heat shock proteins (HSPs) are a group of highly conserved and functionally diverse molecular chaperones that play a crucial role in maintaining cellular homeostasis and coping with a variety of stress responses. HSP70 is one of the important members of the HSPs family, which is involved in the correct folding of proteins, preventing aggregation, and plays a key role in the formation of germ cells, DNA damage repair, fertilization process and embryo implantation in early embryonic development. HSP70 maintains the healthy development of embryos and protects cells from injury under various stress conditions by promoting the normal development and cellular homeostasis of fertilized eggs after fertilization. Through in-depth study of the complex functions and potential mechanisms of HSP70, it is expected to reveal its role in unexplained infertility, recurrent implantation failure, recurrent abortion and other diseases.

Heat shock proteins (HSPs) are a group of highly conserved and functionally diverse molecular chaperones that play a crucial role in maintaining cellular homeostasis and coping with a variety of stress responses. HSP70 is one of the important members of the HSPs family, which is involved in the correct folding of proteins, preventing aggregation, and plays a key role in the formation of germ cells, DNA damage repair, fertilization process and embryo implantation in early embryonic development. HSP70 maintains the healthy development of embryos and protects cells from injury under various stress conditions by promoting the normal development and cellular homeostasis of fertilized eggs after fertilization. Through in-depth study of the complex functions and potential mechanisms of HSP70, it is expected to reveal its role in unexplained infertility, recurrent implantation failure, recurrent abortion and other diseases.

Objective:To explore urological nurses' knowledge, attitude and behavior about early activities in patients undergoing radical cystectomy and the influencing factors, and provide a reference for early activities to be successfully carried out in patients undergoing radical cystectomy.Methods:Totally 240 urological nurses from 10 hospitals in Guangdong Province were selected using convenient sampling and investigated with the general information questionnaire and the urological nurse's knowledge, attitude and behavior about early activities in patients undergoing radical cystectomy questionnaire between October and December 2018. Multiple linear regression was used to analyze the influencing factors.Results:The urological nurses' knowledge, attitude, and behavior scores about early activities of patients undergoing radical cystectomy were (3.42±1.23) , (30.40±3.18) and (10.65±2.20) . Multiple linear regression showed that job title was the influencing factor of urological nurses' knowledge towards early activities in patients undergoing radical cystectomy ( P<0.05) ; working years in urology department, job title and whether they received early activity-related training were the influencing factors of urological nurses' attitude towards early activities in patients undergoing radical cystectomy ( P<0.05) ; whether their department carried out accelerated rehabilitation surgery and whether they received early activity-related training were the influencing factors of urological nurses' behavior about early activities in patients undergoing radical cystectomy ( P< 0.05) . Conclusions:Nurses have a good attitude towards early activities of patients undergoing radical cystectomy, but their knowledge reserves and behaviors are not satisfying. It is necessary to strengthen the training of nurses on the knowledge of early activities, formulate an early activity plan based on multi-disciplinary cooperation, and promote the proper and effective implementation of early activities in clinical practice.