BACKGROUND:In recent years,the study of single-cell RNA sequencing technology in spinal cord injury has provided new insights into cellular and molecular heterogeneity as well as structural changes in the central nervous system after trauma.OBJECTIVE:To review the research progress of single-cell RNA sequencing technology in spinal cord injury,comprehensively and deeply expound the application of single-cell RNA sequencing technology in spinal cord injury.METHODS:A computerized system was used to search the articles published from 2009 to 2023 in PubMed,Web of Science,CNKI,and WanFang databases with the Chinese and English search terms of "single-cell RNA sequencing,spinal cord injury,sequencing technology." Articles with poor quality,repetitive content,and non-relevance were excluded,and 57 articles were finally included for review and analysis.RESULTS AND CONCLUSION:At present,the research of single-cell RNA sequencing technology in spinal cord injury can be summarized as follows:(1) Cell subsets such as microglia,astrocytes,oligodendrocytes,macrophages,B cells,neurons,and neural stem cells were identified,and specific marker genes of these subsets were identified.(2) Microglia remain permanently active after spinal cord injury and coordinate the early stages after spinal cord injury through proliferation,immunity,and homeostatic function.Astrocytes play many important functions in spinal cord injury in an activated manner,including maintaining microenvironment balance,removing necrotic tissue,forming a protective barrier,and glial scars.Both macrophages and microglia play an important role in chronic neuroinflammation following spinal cord injury.(3) Neural stem cells and neuronal subsets can self-renew after spinal cord injury.Newly discovered neuronal subsets such as SCVsx2::Hoxa7:Zfhx3 → lumbar and SCVsx2:Hoxa10 can regenerate to natural targets and facilitate the recovery of motor function.(4) The discovery of dynamic changes in cell subsets improves our understanding of the course of spinal cord injury lesions and provides new insights into the treatment of spinal cord injury at different time points.Up to now,more basic research and sufficient clinical experiments are needed to validate the results of single-cell RNA sequencing in these studies.In the future,single-cell RNA sequencing technology is expected to open a new window for the diagnosis and treatment of spinal cord injury by interdisciplinary collaboration with bioinformatics,computer science,tissue engineering,and clinical medicine.

BACKGROUND:In recent years,the study of single-cell RNA sequencing technology in spinal cord injury has provided new insights into cellular and molecular heterogeneity as well as structural changes in the central nervous system after trauma.OBJECTIVE:To review the research progress of single-cell RNA sequencing technology in spinal cord injury,comprehensively and deeply expound the application of single-cell RNA sequencing technology in spinal cord injury.METHODS:A computerized system was used to search the articles published from 2009 to 2023 in PubMed,Web of Science,CNKI,and WanFang databases with the Chinese and English search terms of "single-cell RNA sequencing,spinal cord injury,sequencing technology." Articles with poor quality,repetitive content,and non-relevance were excluded,and 57 articles were finally included for review and analysis.RESULTS AND CONCLUSION:At present,the research of single-cell RNA sequencing technology in spinal cord injury can be summarized as follows:(1) Cell subsets such as microglia,astrocytes,oligodendrocytes,macrophages,B cells,neurons,and neural stem cells were identified,and specific marker genes of these subsets were identified.(2) Microglia remain permanently active after spinal cord injury and coordinate the early stages after spinal cord injury through proliferation,immunity,and homeostatic function.Astrocytes play many important functions in spinal cord injury in an activated manner,including maintaining microenvironment balance,removing necrotic tissue,forming a protective barrier,and glial scars.Both macrophages and microglia play an important role in chronic neuroinflammation following spinal cord injury.(3) Neural stem cells and neuronal subsets can self-renew after spinal cord injury.Newly discovered neuronal subsets such as SCVsx2::Hoxa7:Zfhx3 → lumbar and SCVsx2:Hoxa10 can regenerate to natural targets and facilitate the recovery of motor function.(4) The discovery of dynamic changes in cell subsets improves our understanding of the course of spinal cord injury lesions and provides new insights into the treatment of spinal cord injury at different time points.Up to now,more basic research and sufficient clinical experiments are needed to validate the results of single-cell RNA sequencing in these studies.In the future,single-cell RNA sequencing technology is expected to open a new window for the diagnosis and treatment of spinal cord injury by interdisciplinary collaboration with bioinformatics,computer science,tissue engineering,and clinical medicine.

OBJECTIVE To understand the epidemiological characteristics and change of drug resistance of Klebsiel-la pneumoniae strains from a hospital so as to adjust the use of antibiotics and control the transmission of hospital-associated infection caused by the K.pneumoniae.METHODS The K.pneumoniae strains were isolated from the patients who were hospitalized in The 305 Hospital of PLA from 2018 to 2022.The data of drug susceptibility tes-ting were exported by using WHONET 5.6,the clinical data and changing trend of drug resistance were retro-spectively analyzed with the use of SPSS 25.0 software.RESULTS Totally 9157 strains of bacteria were isolated from the patients who were hospitalized from 2018 to 2022,1502(16.40％)of which were K.pneumoniae,and the isolation rate showed a downward trend(x2=15.054,P＜0.001).Sputum(77.16％)was the major type of specimen;the strains were mainly isolated from intensive care unit(55.26％).The patients aged more than 79 years old were dominant,accounting for 65.58％.The result of drug susceptibility testing showed that there were significant differences in the drug resistance rates to the commonly used antibiotics from 2018 to 2022(P＜0.05).The drug resistance rates to aztreonam,ertapenem and tigecycline showed upward trends with the years(P＜0.05),while the drug resistance rates to the rest of drugs such as cefoperazone-sulbactam,ceftazidime and amika-cin showed downward trends(P＜0.05).CONCLUSIONS There is significant difference in the clinical distribution of the K.pneumoniae strains in recent 5 years.The key populations and departments should be attached great im-portance to.The drug resistance rates of the K.pneumoniae strains to many types of antibiotics show downward trends,but the situation of drug resistance is still serious.It is necessary to continue to implement the prevention and control policies for drug resistance and reasonably use antibiotics based on the result of drug susceptibility testing.

OBJECTIVE To understand the epidemiological characteristics and change of drug resistance of Klebsiel-la pneumoniae strains from a hospital so as to adjust the use of antibiotics and control the transmission of hospital-associated infection caused by the K.pneumoniae.METHODS The K.pneumoniae strains were isolated from the patients who were hospitalized in The 305 Hospital of PLA from 2018 to 2022.The data of drug susceptibility tes-ting were exported by using WHONET 5.6,the clinical data and changing trend of drug resistance were retro-spectively analyzed with the use of SPSS 25.0 software.RESULTS Totally 9157 strains of bacteria were isolated from the patients who were hospitalized from 2018 to 2022,1502(16.40％)of which were K.pneumoniae,and the isolation rate showed a downward trend(x2=15.054,P＜0.001).Sputum(77.16％)was the major type of specimen;the strains were mainly isolated from intensive care unit(55.26％).The patients aged more than 79 years old were dominant,accounting for 65.58％.The result of drug susceptibility testing showed that there were significant differences in the drug resistance rates to the commonly used antibiotics from 2018 to 2022(P＜0.05).The drug resistance rates to aztreonam,ertapenem and tigecycline showed upward trends with the years(P＜0.05),while the drug resistance rates to the rest of drugs such as cefoperazone-sulbactam,ceftazidime and amika-cin showed downward trends(P＜0.05).CONCLUSIONS There is significant difference in the clinical distribution of the K.pneumoniae strains in recent 5 years.The key populations and departments should be attached great im-portance to.The drug resistance rates of the K.pneumoniae strains to many types of antibiotics show downward trends,but the situation of drug resistance is still serious.It is necessary to continue to implement the prevention and control policies for drug resistance and reasonably use antibiotics based on the result of drug susceptibility testing.

The conidia of Pseudomonas Migula Y 1were mutagenized by NTG, Co 60 and UV respectively. Chitosanase-producing mutant of Pseudomonas Migula Y 8 was obtained by screening with the method of transparent zones . Its chitosanase activity was 3.0 U?mL, -1 which has increased by six times approximately. The method of UV was better than others.