In order to investigate the effects of porin genes ompW,ompS and ompD on the biological properties and virulence of Salmonella typhimurium,the corresponding mutant strains were con-structed using the λ Red homologous recombination system,and the growth curves,motility,bio-chemical properties,in vitro genetic stability,biofilm-forming ability,drug resistance,and lethal dose at half capacity(LD50)between the standard strain and each mutant strain were detected by comparative assays for Salmonella typhimurium.The results showed that,compared with the standard strain,the ompD and ompW mutation had less effect on the growth rate and motility of the bacteria,while the ompS mutation significantly reduced the growth rate and motility;none of the three genetic mutation affected the biochemical characteristics of Salmonella typhimurium,nor the genetic stability,but affected its susceptibility to a variety of commonly used antibiotics to varying degrees and caused a highly significant decrease(P＜0.01)in the ability to form a biofilm,and the results showed that the three mutant strains had a significant reduction in the ability to form a biofilm.The result of LD50 virulence assay showed that all three genetic mutation led to a decrease in the virulence of Salmonella typhimurium,among which the ompS mutant strain showed the most obvious decrease in virulence,LD50 was 25 times that of the standard strain.In conclusion,mutations of the pore protein ompW,ompS,and ompD genes can affect some biological properties of Salmonella typhimurium.The results of this study laid an experimental foundation for further research on the biological functions of the pore protein ompW,ompS and ompD genes and Salmonella pathogenicity.

Objective:To investigate the current status and quality and safety of radiation therapy resources in medical institutions in Hunan province.Methods:The basic situation questionnaire, quality and safety self-assessment form were designed according to the content of the survey, distributed and recovered through the network, and the survey was conducted on all medical institutions (excluding military hospitals) conducting radiotherapy in Hunan province in 2022, and the quality and safety evaluation was checked by the Hunan Radiotherapy Quality Control Center using stratified sampling field inspection. The differences between the self-evaluation scores of radiotherapy quality and safety and the on-site inspection scores of each unit was compared using Wilcoxon test.Results:By the end of 2022, there were 76 medical institutions (excluding military hospitals) conducting radiotherapy in Hunan province, including 62 tertiary hospitals and 14 secondary hospitals, with a total of 44 253 radiotherapy patients admitted annually. The total number of personnel engaged in radiotherapy was 1 381, including 746 physicians, 205 physicists, 397 technicians and 33 maintenance engineers. There were a total of 88 accelerators (including 3 tomotherapy units), 10 gamma knives, and 28 rear-loading machines, with 1.33 gas pedals per million population. There were 36 units that were carrying out three-dimensional conformal technology, 60 static intensity modulation technology, 20 volumetric rotational intensity modulation, 27 stereotactic radiotherapy, 44 image-guided radiotherapy, 33 respiratory motion management, and 27 rear-loading radiotherapy. In the quality and safety evaluation situation, the basic requirements of radiotherapy specialty scored high, with 2 units achieving full marks and no failing units. Radiotherapy personnel and organization, radiotherapy process, documentation record score and other aspects of no full-score units, the score was concentrated in 60~＜80 points, and all have part of the unit failed.Conclusions:The radiotherapy industry in Hunan province has been developed steadily in recent years in general, and the structure of radiotherapy personnel tends to be reasonable, but there still exists uneven distribution of radiotherapy resources, poor utilization of equipment in some areas, and inadequate development of technology. The overall quality and safety evaluation are good, but there are still many deficiencies in the organizational requirements of radiotherapy personnel, process requirements and documentation, which need to be continuously optimized and improved in the future, and at the same time, field inspections will be intensified to ensure the quality and safety of radiotherapy.

Objective To predict risk factors affecting the prognosis of HIV/AIDS patients with Candida infection, providing clinicians with predictors for early identifying high-risk patients. Methods Clinical data were collected from HIV/AIDS patients with Candida infection admitted to an infectious disease hospital in Guangxi from January 2012 to June 2019. Patients were divided into a death group and a survival group according to their different prognostic outcomes. Cases were randomly selected and matched using propensity score matching (PSM) at a ratio of 1∶3 (death: survival) to construct the model. The data were split into a training set and a testing set at a ratio of 7∶3. Various machine learning models were built, and the optimal model was selected as the final prediction model by comprehensively evaluating the model performance. Finally, the SHAP values were used to interpret the features of the model and analyze the influencing factors of patients' prognostic outcomes. Results A total of 3 098 HIV/AIDS patients with Candida infection were collected. From 2012 to June 2019, the in-hospital mortality rate of HIV/AIDS patients with Candida infection showed a linear and stable downward trend (P=0.043). After applying PSM, data from 1 620 cases were used to construct six different machine learning models, among which the XGBoost model had the best performance (training/testing set, AUC=0.98/0.85, sensitivity=0.93/0.75, specificity=0.93/0.84). Respiratory failure, urea, and LDH levels were thought to be the three major factors affecting the prognostic outcomes of HIV/AIDS patients with Candida infection. Conclusions The XGBoost model showed good predictive performance in predicting prognostic outcomes of HIV/AIDS patients with Candida infection. The model can provide early warning for the identification of high-risk patients and assist clinicians to take personalized treatment measures promptly, which is of great significance for guiding clinical decision-making.

Objective:To realize the automatic evaluation of the target conformity, dose overflow, dose drop and other indicators in stereotactic body radiation therapy (SBRT) plan for the early non-small cell lung cancer (NSCLC) in the Eclipse planning system.Methods:Eclipse Scripting API application development interface and C# programming language were used to develop it with script plug-ins combined with independent programs. According to the requirements of the NSCLC SBRT plan in Radiation Therapy Oncology Group (RTOG) 0915 report, the automatic evaluation of related indicators was realized. A rule of equal interval sampling and double thresholds was designed during the period, which could more accurately and conveniently evaluate the dose drop outside the target area.Results:13 clinical cases of NSCLC SBRT plans were randomly selected, the method in this study and the module equipped with the Eclipse system to were utilized to evaluate and compare the results. It was concluded that the results of the two methods were in line with the clinical requirements, and the former was more efficient ( P<0.05). Conclusions:The NSCLC SBRT plan evaluation software in this article has a friendly interface. It can not only realize the automatic evaluation of target conformity, dose overflow and dose drop, but also effectively improve work efficiency and better serve the clinical and scientific research work of radiotherapy.

Objective To analyze the spatial and temporal characteristics of hand, foot and mouth disease (HFMD) in Hunan Province from 2016 to 2020. Methods The data of HFMD in Hunan Province from 2016 to 2020 were collected from China's Disease Prevention and Control Information System. HFMD spatial autocorrelation analysis was conducted by ArcGIS 10.2 software at county level, and spatial-temporal scan statistical analysis was performed by SaTScan 9.7 software. Results A total of 714 157 cases was reported in Hunan Province during 2016-2020, with an average annual incidence rate of 208.36/100 000. Global spatial autocorrelation showed that HFMD had a positive spatial correlation on the county scale in Hunan Province during this period. Local spatial autocorrelation indicated that the hot spots were mainly concentrated in the north of central Hunan, the east of central Hunan and the west of Hunan. Spatial-temporal scanning analysis revealed the first class clusters (RR = 6.65, P< 0.001) covering 34 counties in northern and central Hunan, mainly distributed in Yueyang City, Changsha City, Zhuzhou City, Yiyang City and Xiangtan City from May 2018 to June, and the second class clusters (RR = 3.02, P < 0.001) covering 40 counties in western Hunan and central and southwest Hunan from April 2016 to June 2016. Conclusion HFMD incidence exhibits seasonal and regional characteristics in Hunan Province. The prevention and control of HFMD should be guided by combining the characteristics of spatial-temporal clustering.

Spinocerebellar ataxias are a high clinically and genetically heterogeneous group of neurodegenerative disorders, usually belongs to autosomal dominant hereditary cerebellar ataxia. Spinocerebellar ataxia type 5 (SCA5) is one of the extremely rare subtypes and caused by heterozygous mutation of SPTBN2 gene. A case of infant-onset SCA5 patient is reported, mainly manifested as global developmental delay, ataxia and dysarthria, carrying the heterozygous missense variant c.1438C>T (p. Arg480Trp) in the SPTBN2 gene. This mutation may have an important impact on functional regions of the β-Ⅲ spectrin, leading to the occurrence of disease.

Objective:To realize the interactive form evaluation of radiotherapy dose and the automatic calculation of conformity index (CI) and heterogeneity index (HI) in the Eclipse planning system.Methods:The Eclipse Scripting API application development interface and C# programming language were employed to develop it with script plug-ins combined with independent programs. The visual interface programming and call the relevant dose query function in the API were utilized to realize the interactive table dose evaluation and the automatic calculation of HI. The functions of calling dosage structure creation and structure Boolean operation in the API were adopted to realize the automatic calculation of CI.Results:15 clinical radiotherapy cases of nasopharyngeal carcinoma were selected. The dose evaluation results were statistically compared between this method and the module equipped in the Eclipse system. The results showed that the accuracy was consistent between these two methods ( P>0.05), whereas the evaluation efficiency of this method was significantly higher compared with that of the Eclipse system module ( P<0.05). Conclusions:The interactive evaluation form in this article has a friendly interface, which allows users to more conveniently perform dose assessment, multi-plan comparison, and calculation of CI and HI, which effectively improves work efficiency and can better serve the clinical and scientific research work of radiotherapy.

Objective:To observe the presence or absence of necroptosis in PC12 cells after radiation injury, and to detect the expression of receptor-interacting protein 3(RIP3) and evaluate its regulatory effect on necroptosis.Methods:PC12 cells were treated with different doses of irradiation and their necroptosis was detected by lactate dehydrogenase (LDH) release at different time points. After pretreatment with necroptosis inhibitor Necrostatin-1(Nec-1), the changes of cell necroptosis were detected by LDH. The expression level of RIP3 after irradiation intervention was detected by Western blot (WB). After pretreatment with the RIP3-specific inhibitor GSK′872, the changes of cell necroptosis were detected by LDH. The best transfection sequence of RIP3 knockout was screened by WB. The cells were divided into the control group, irradiation group, solvent control group, no-load control group and pretreatment group. WB, immunofluorescence staining, MTT, LDH and Annex V-fluorescein Isothiocyanate/Propidium Iodide (AnnexV-FITC/PI) flow cytometry were used for detection and analysis.Results:After 4 Gy irradiation, the degree of cell necrosis was the highest after 3 hours of culture, and the expression level of RIP3 protein was up-regulated. The cell necrosis was decreased after Nec-1, GSK′872 and RIP3 gene knockdown pretreatment.Conclusions:The radiation injury of 4 Gy can induce the necroptosis of PC12 cells, and the most significant effect can be observed when cultured for 3 hours after irradiation. RIP3 is involved in the process of necroptosis of PC12 cells induced by radiation injury, and plays a pivotal positive regulatory role.

Objective:To analyze the epidemiological and etiological characteristics of a dengue fever outbreak in Hunan province in 2018.Methods:Real-time PCR assay was performed for the laboratory diagnosis of 8 suspected dengue fever cases. Etiological surveillance was performed in 186 suspected dengue fever cases and fever cases who had close contacts with dengue fever patients. C6/36 cells was used for the virus isolation from acute phase serum. By sequencing the full length of E genes of 15 dengue virus strains, phylogenetic analysis was performed based on the sequences obtained, including reference sequences from the NCBI GenBank database, the serotypes and gene subtypes of the virus were analyzed to trace the possible source of transmission. An emergency monitoring of vector density and a retrospective survey of sero-epidemiology in healthy population were conducted in the epidemic area.Results:In the serum samples of 8 suspected patients, 6 were dengue virus RNA positive, and 4 were NS1 antigen positive. In 186 suspected patients, 96 were dengue virus nucleic acid, NS1 antigen or antibody positive in etiological test. A total of 64 dengue virus strains were isolated. The phylogenetic analysis showed that all the dengue virus strains belonged to type 2, which might be from Guangdong or Zhejiang provinces. The Bretub index was up to 65, indicating an extremely high risk of transmission. The positive rate of the dengue virus IgG antibody was 0.53%(2/377) in retrospective survey of 377 healthy people.Conclusion:The field epidemiologic and the molecular genetics analyses showed the outbreak of dengue fever in Hunan in 2018 was caused by imported cases and dengue virus 2.

Objective:To confirm the first imported Chikungunya fever (CHIK) epidemic in Hunan province.Methods:Serum samples of patients and colleagues were collected. The nucleic acids of Dengue virus (DENV), Yellow fever virus (YFV), Chikungunya virus (CHIKV) were detected by real- time fluorescent quantitative PCR. The positive PCR products were sequenced. Phylogenetic tree was constructed.Results:The serum samples of the patient and one of the five colleagues were positive for CHIKV. The Blast comparison of gene sequence showed 99% homology with CHIKV sequences. The infected CHIKV belonged to ECSA genotype in the phylogenetic tree.Conclusions:The first imported CHIK epidemic in Hunan province was confirmed through the epidemiological survey and etiologic detection.