BACKGROUND:Exosomes,as a type of extracellular vesicle,have become a key medium for cell-to-cell communication due to their nanoscale size and enrichment of various bioactive substances.The study of exosome secretion regulation not only has important scientific value,but also has broad application prospects in clinical practice,and is of great significance for promoting medical progress and improving human health.OBJECTIVE:To review the biological characteristics,biological functions,biogenesis process and biochemical regulation mechanism of exosomes,and to explore the application prospects of exosomes in disease diagnosis,treatment and vaccine development,so as to provide theoretical basis and reference for basic research and clinical transformation of exosomes.METHODS:The first author searched PubMed and CNKI databases in October 2024 for relevant literature published from January 2010 to October 2024.Key words were"exosomes,biological functions,biogenesis,secretion or release,regulatory mechanisms,application prospects"in Chinese and English.Finally,92 articles were included for analysis.RESULTS AND CONCLUSION:The secretion level of exosomes can be regulated through physical or biochemical means.Exosomes show broad application prospects in the fields of disease diagnosis,treatment,and vaccine development,and may play a key role in the treatment of cardiovascular and cerebrovascular diseases as well as cancer.This review provides valuable information for the clinical translation and application research of exosomes,helping to promote future progress in exosome research and application.

BACKGROUND:Exosomes,as a type of extracellular vesicle,have become a key medium for cell-to-cell communication due to their nanoscale size and enrichment of various bioactive substances.The study of exosome secretion regulation not only has important scientific value,but also has broad application prospects in clinical practice,and is of great significance for promoting medical progress and improving human health.OBJECTIVE:To review the biological characteristics,biological functions,biogenesis process and biochemical regulation mechanism of exosomes,and to explore the application prospects of exosomes in disease diagnosis,treatment and vaccine development,so as to provide theoretical basis and reference for basic research and clinical transformation of exosomes.METHODS:The first author searched PubMed and CNKI databases in October 2024 for relevant literature published from January 2010 to October 2024.Key words were"exosomes,biological functions,biogenesis,secretion or release,regulatory mechanisms,application prospects"in Chinese and English.Finally,92 articles were included for analysis.RESULTS AND CONCLUSION:The secretion level of exosomes can be regulated through physical or biochemical means.Exosomes show broad application prospects in the fields of disease diagnosis,treatment,and vaccine development,and may play a key role in the treatment of cardiovascular and cerebrovascular diseases as well as cancer.This review provides valuable information for the clinical translation and application research of exosomes,helping to promote future progress in exosome research and application.

The synthetic PDCoV N protein gene was optimized and cloned into the pET-30a vector to obtain the pET-30a-N plasmid.Thenthe recombinant plasmid was transformed into three strains of BL21 E.coli using heat-shock to explore protein expression conditions.The expressed proteins was purified using Ni Focurose 6FF(IMAC)and used as antigen to immunize the New Zealand White rabbit to prepare the polyclonal antibody against the PDCoV N protein.The antibody titer was measured by indirect ELISA method.The specificity for the antibody was identified by West-ern blot and indirect immunofluorescence(IFA).The results showed that the pET-30a-N plasmid showed high expression level in BL21 StarTM(DE 3).The optimal expression condition was 37 ℃ 4 h.The purity of the target protein could reach 90.3％after purification.Indirect ELISA showed that the antibody titers was up to 1∶204 800.Western blot and IFA showed that the produced rabbit polyclonal antibody exhibited good specificity.In conclusion,the polyclonal antibody was prepared which specifically recognized the PDCoV N proteins.The results provided some references for the subsequent exploration of PDCoV N protein function and laid a foundation for establishing a diag-nostic method for PDCoV.

The synthetic PDCoV N protein gene was optimized and cloned into the pET-30a vector to obtain the pET-30a-N plasmid.Thenthe recombinant plasmid was transformed into three strains of BL21 E.coli using heat-shock to explore protein expression conditions.The expressed proteins was purified using Ni Focurose 6FF(IMAC)and used as antigen to immunize the New Zealand White rabbit to prepare the polyclonal antibody against the PDCoV N protein.The antibody titer was measured by indirect ELISA method.The specificity for the antibody was identified by West-ern blot and indirect immunofluorescence(IFA).The results showed that the pET-30a-N plasmid showed high expression level in BL21 StarTM(DE 3).The optimal expression condition was 37 ℃ 4 h.The purity of the target protein could reach 90.3％after purification.Indirect ELISA showed that the antibody titers was up to 1∶204 800.Western blot and IFA showed that the produced rabbit polyclonal antibody exhibited good specificity.In conclusion,the polyclonal antibody was prepared which specifically recognized the PDCoV N proteins.The results provided some references for the subsequent exploration of PDCoV N protein function and laid a foundation for establishing a diag-nostic method for PDCoV.

Objective To evaluate the application effect of modular management in technique and nursing of department of radiology. Methods 7 modules were divided: administrative management, quality management, equipment management, environment and emergency management, material cost management, education management and scientific research management. Each module was responsible for specially-assigned person reporting daily circumstance. Results After more than a year, 16 technical professionals, 8 educational professionals, 10 research professionals and 7 technicians were cultivated, 12 key performance indicators (KPI value) increased steadily were set up. Conclusions Modular management provided a novel concept for technique and medical care management of radiology department. Our practice suggests that modular management is alternative for development of technique and medical care in radiology department. Further research and application are needed.

Objective　Recombinant human pro-urokinase forms insoluble inclusion body when overexpressed in Escherichia coli. It must be denatured and renatured in vitro so that it can acquire activity. This study aimed at increasing the renaturation yield of denaturant pro-urokinase. Methods　We evaluated the basic renaturation conditions of pro-urokinase through qualitative and quantitative analysis of pH, temperature, denatured concentration, protein concentration, and the ratio of reduced and oxidized thiol reagents. We also compared the effects of nonspecific additives, step-wise dilution and urea gradient dialysis. Results　We defined the optimal conditions of pro-urokinase renaturation with a yield of about 20%-30%. Conclusion　Different recombinant denatured proteins have different renaturation conditions due to their different molecular sizes, molecular constructions, disulfide bond numbers, and hydrophobicity. The renaturation yield can be increased by optimizing the renaturation conditions of a specific protein.