This study was aimed at identifying the pathogenic bacteria responsible for the death of a young tiger at the Fujian Meihua Mountain South China Tiger Breeding Research Institute.Tissue samples from the lungs,liver,and intestines of the deceased tiger were collected,and the bacteria were cultured inasterile environment.The bacterial strains were characterized according to their morphological and molecular biological properties,including assessment of virulence genes and antibiotic resistance genes,mouse lethality tests,and antibiotic susceptibility evaluations.A predominant bacterial strain isolated from the liver of the deceased tiger was identified as enterotoxigenic Escherichia coli(ETEC)strain Tiger22513F.Phylogenetic analysis of the 16S rRNA gene revealed that the Tiger22513F strain exhibited close genetic similarity to the reference strain ETEC(MF919609.1),with 99.9%nucleotide similarity,and resided on the same evolutionary branch.The Tiger22513F strain contained 11 antibiotic resistance genes(tetA,sul1,sul3,cmlA,floR,blaTEM,blaSHV,blaCMY-2,qnrA,qnrS,and qnrD)along with five virulence genes(VT1,fyuA,tsh,iucD,and ST).Mouse lethality tests indicated significant pathogenicity toward mice,affecting primarily the lungs,liver,and intestines.Antibiotic susceptibility testing demonstrated that this strain exhibited resistance to various classes of beta-lactam antibiotics,as well as quinolones and aminoglycosides.This investigation successfully isolated a multi-drug resistant enterotoxigenic Escherichia coli strain with pronounced pathogenicity from the liver of a deceased tiger;thus providing valuable scientific insights for clinical diagnosis,as well as prevention and control measures,against ETEC infections in South China tigers.

The aim of this study is to identify the cause of death of a South China tiger cub at the Meihuashan breeding institute of Fujian Province.Pathogenic bacteria were isolated and cultured from liver,spleen,lung and other tissue samples of the dead South China tiger aseptically.The iso-lated bacteria were identified through morphological observation,biochemical characterization,sequence analysis of housekeeping gene gyrB,virulence gene detection,animal pathogenicity test and drug sensitivity test.A pathogenic Aeromonas hydrophila strain,designated FJ/Tiger-201809 was successfully isolated from the trachea of dead South China tiger.The nucleotide sequence ho-mology between the isolate and 11 strains of Aeromonas gyrB ranged from 91.2％to 99.1％,with the highest homology of 99.1％observed with Aeromonas hydrophila(AF208251.1).Genetic evo-lution analysis showed that the isolated strain FJ/Tiger-201809 was in the same evolutionary branch as other reference strains of Aeromonas hydrophila and was closely related.The pathoge-nicity test in mice showed artificial infection of mice with the strain resulted in varying degrees of lesions in several organs of the mice,and the median lethal dose(LD50)was 1 × 107.8 CFU/mL.Virulence gene test results showed that the isolate FJ/Tiger-201809 carried two virulence genes,aer and act.The results of drug sensitivity test showed that FJ/Tiger-201809 was highly sensitive to enrofloxacin and ampicillin among 18 commonly used antibiotics,relatively sensitive to penicil-lin G and doxycycline,and resistant to the other 14 antibiotics.In conclusion,this study isolated and identified a strain of Aeromonas hydrophila from a dead South China tiger with multiple drug resistance and strong pathogenicity,which provided an important reference for the prevention and control of bacterial diseases in South China tiger.

Objective:To analyze the transition patterns of anal sex and unprotected anal intercourse (UAI), estimate the transition intensity and probability, and identify factors influencing the transition patterns in men who have sex with men (MSM) in Shandong Province.Methods:In August 2019, MSM aged ≥18 years old were recruited as subjects from 11 cities in Shandong Province. The baseline survey were completed in December 2019, and followup surveys were conducted once every 3 mouths from June 2020 to March 2021. Time-continuous, state-discrete multi-state reversible Markov model was constructed based on the status of MSM's sexual behaviors with different types of sexual partners [anal sex occurred or not (S1=No, S2=Yes) and UAI occurred or not (S1=No,S2=Yes)] to analyze the transition patterns and the influencing factors.Results:A total of 735 MSM were included. The transition intensity of starting anal sex with stable and casual partners was 1.935 times and 0.595 times higher than that of discontinuing this behavior, respectively. While the transition intensity to start UAI with stable and casual partners was 0.430 times and 0.169 times higher than that of discontinuing it, respectively. During the follow-up, the transition probabilities of anal sex and UAI with both stable and casual partners increased first and then stabilized. For stable partners, the transition probability of starting anal sex was higher than that of discontinuing it at the same period, for casual partners, it was just the reverse. For both stable and casual partners, the transition probabilities of discontinuing UAI were higher than starting it at the same time. The results of multivariate analysis showed that participants who received intervention materials ( HR=1.47), had an associate degree ( HR=1.77) or a bachelor's degree and above ( HR=1.47) were at higher risk of starting anal sex with stable partners. Those who received intervention materials ( HR=1.39) were at higher risk of discontinuing anal sex with stable partners, while participants identified themselves as non-male gender ( HR=0.49) were at lower risk of discontinuing anal sex with stable partners. Participants received intervention materials ( HR=1.75) were at higher risk of starting UAI with stable partners. Those who lived apart, divorced, or widowed ( HR=3.22) were at higher risk of starting UAI with casual partners, whereas had a bachelor's degree and above ( HR=0.58) were at lower risk of starting UAI with casual partners. Participants identified themselves as non-male gender ( HR=0.45) at lower risk of discounting UAI with casual partners. Conclusions:The transition patterns of homosexual behavior in MSM are different. Marital status, gender identity, educational level and other factors are the influencing factors of sexual behavior status transitions. Future researches should develop targeted interventions for different types of sexual partners and characteristics of MSM.

Objective This study aimed to investigate the value of PET/CT radiomics combined with machine learning in differentia-ting primary central nervous system lymphoma(PCNSL)from brain metastases(BM).Methods Sixty-nine patients with 127 lesions(including 43 PCNSL lesions and 84 BM lesions)who attended the Department of Nuclear Medicine of Lanzhou University Second Hospi-tal from January 2019 to November 2024 were selected and divided into a training set(n=88)and a validation set(n=39)in a 7∶3 rati-o.Radiomics features of PET and CT were extracted using the 3D slicer,and feature dimensionality reduction was performed using least absolute shrinkage and selection operator(LASSO)regression combined with 5-fold cross-validation to construct three classical machine learning models-Logistic regression(LR),decision tree(DT),and support vector machine(SVM),and the diagnostic efficacy of each model was evaluated using receiver operating characteristic(ROC)curves and confusion matrices.Results The SVM model based on PET imaging performed best in the validation set[area under the curve(AUC)=0.917,sensitivity=84.6％,specificity=92.3％]and was significantly better than the CT model(AUC=0.787,sensitivity=73.1％,specificity=76.9％).Conclusion The support vector machine model constructed based on PET radiomics metabolic features demonstrated high diagnostic value in the preoperative differentia-tion between PCNSL and BM,showing potential for clinical application as a non-invasive auxiliary diagnostic tool.

Objective To explore practical pathways for the connotation quality control of Zhuang medical records by le-veraging the reform of DRG-based medical insurance payment systems as an opportunity,thereby enhancing record quality and fostering the coordinated development of ethnic medicine with modern medical insurance payment systems.Methods By analy-zing the requirements imposed by the DRG-based payment reform on the quality management of Zhuang medical records,a quality control management system focused on the connotation quality control of these records was established.A scoring standard for the connotation quality of Zhuang medical records,supplemented by DRG,was developed.Dynamic quality control was implemented through a combination of information-based intelligent review and expert manual review to ensure rectification.Results Key in-dicators,such as the qualification rate of the first page of medical records,the A-level rate of inpatient records,and the DRG en-rollment rate,showed significant improvements.The documentations of surgical and procedural records were standardized,and the records of ward rounds and case discussions by senior physicians were comprehensive and detailed,accurately reflecting the diagnostic and therapeutic methods and outcomes of Zhuang medicine.Conclusion The DRG-based quality control model for Zhuang medical records effectively aligns medical insurance payment with the unique characteristics of ethnic medicine,offering a replicable model for the quality management of medical records in ethnic medicine institutions under DRG-based reforms.

Objective:The aim of this study was to explore the risk factors that affect implementation of the innovative technique of single-incision laparoscopic appendectomy (solo-SLA) without assistance in patients with complicated appendicitis, the goal being improving surgical success rates and reducing the incidence of complications.Methods:This was an observational study. Indications for solo-SLA surgery were as follows: (1) computed tomography or ultrasound findings suggestive of acute appendicitis, accompanied by a high white blood cell count and C-reactive protein concentration; (2) disease course exceeding 72 hours, standard anti-infection treatment ineffective, inflammatory reaction not localized, surgery mainly aimed at abscess drainage, and the appendix removed if indicated intraoperatively; (3) acute onset stabilized for more than 3 months after conservative treatment; and (4) recurrent chronic appendicitis. Relative contraindications comprised: (1) cardiopulmonary insufficiency, extremely high risk for general anesthesia for laparoscopic surgery; (2) severe coagulation dysfunction; and (3) imaging findings suggestive of formation of a peri-appendiceal abscess, stable after anti-infection treatment, and a tendency for the inflammatory reaction to localize. We retrospectively collected clinical data of 106 patients with complicated appendicitis who had undergone solo-SLA in the Department of Emergency Surgery, Peking University People's Hospital from February to October 2023. Preoperative computed tomography showed appendiceal fecaliths, blurring of the tissue surrounding fat, intra- and extra-luminal gas and exudate, peri-appendiceal abscess, ascites, and intestinal obstruction by appendicitis. The study cohort comprised 53 male and 53 female patients aged (41.4±17.4) years. The median body mass index was (24.2±3.6) kg/m 2 and median preoperative body temperature (37.3±0.9)℃ Appendicitis had been present for >3 days in 21 of the patients (19.8%) and the maximum diameter of the appendix was (12.4±3.8) mm. The efficacy of the surgery was assessed and logistic regression analysis used to explore the factors affecting the duration of the procedure. The relationship between the maximum diameter of the appendix and duration of surgery was non-linear and was explored using a logistic regression model with restricted cubic spline (RCS). Results:Only one patient required conversion to open surgery; all the other patients successfully completed solo-SLA with a median intraoperative blood loss of 10 (1-100) ml and a surgical time of (65.4±31.7) minutes. Pain scores on postoperative Day 1 and 7 were (3.4±3.2) points and (1.5±1.7) points, respectively. There were no significant postoperative complications .The postoperative hospital stay was (3.5±1.5) days and the interval to resuming normal activities 14 (2-40) days. According to univariate and multivariate analyses, disease course >3 days (OR=5.19, 95%CI: 1.59-16.98, P=0.006) and C-reactive protein >10 mg/L (OR=1.01,95%CI: 1.00-1.02, P=0.003) were independent risk factors for surgical duration >60 minutes, whereas the maximum diameter of the appendix was not independently associated with duration of surgery (OR=1.10, 95%CI: 0.97-1.25, P=0.119). RCS analysis results showed a "U-shaped" association between the maximum diameter of the appendix and duration of surgery, the inflection point of the RCS curve being at a diameter of 10 mm. When the maximum diameter of the appendix was <10 mm, increases in diameter were not associated with longer duration of surgery (OR=1.15,95%CI: 0.55-2.58, P=0.710); whereas when the diameter was ≥10 mm, the maximum diameter of the appendix was associated with increased duration of surgery (OR=1.20, 95% CI: 1.04-1.42, P=0.022). Conclusion:The solo-SLA procedure can be performed to treat complicated appendicitis. A disease course >3 days, C-reactive protein concentration >10 mg/L, and maximum diameter of the appendix ≥10 mm are all associated with greater difficulty of solo-SLA surgery.

This study was aimed at identifying the pathogenic bacteria responsible for the death of a young tiger at the Fujian Meihua Mountain South China Tiger Breeding Research Institute.Tissue samples from the lungs,liver,and intestines of the deceased tiger were collected,and the bacteria were cultured inasterile environment.The bacterial strains were characterized according to their morphological and molecular biological properties,including assessment of virulence genes and antibiotic resistance genes,mouse lethality tests,and antibiotic susceptibility evaluations.A predominant bacterial strain isolated from the liver of the deceased tiger was identified as enterotoxigenic Escherichia coli(ETEC)strain Tiger22513F.Phylogenetic analysis of the 16S rRNA gene revealed that the Tiger22513F strain exhibited close genetic similarity to the reference strain ETEC(MF919609.1),with 99.9%nucleotide similarity,and resided on the same evolutionary branch.The Tiger22513F strain contained 11 antibiotic resistance genes(tetA,sul1,sul3,cmlA,floR,blaTEM,blaSHV,blaCMY-2,qnrA,qnrS,and qnrD)along with five virulence genes(VT1,fyuA,tsh,iucD,and ST).Mouse lethality tests indicated significant pathogenicity toward mice,affecting primarily the lungs,liver,and intestines.Antibiotic susceptibility testing demonstrated that this strain exhibited resistance to various classes of beta-lactam antibiotics,as well as quinolones and aminoglycosides.This investigation successfully isolated a multi-drug resistant enterotoxigenic Escherichia coli strain with pronounced pathogenicity from the liver of a deceased tiger;thus providing valuable scientific insights for clinical diagnosis,as well as prevention and control measures,against ETEC infections in South China tigers.

Objective:To analyze the transition patterns of anal sex and unprotected anal intercourse (UAI), estimate the transition intensity and probability, and identify factors influencing the transition patterns in men who have sex with men (MSM) in Shandong Province.Methods:In August 2019, MSM aged ≥18 years old were recruited as subjects from 11 cities in Shandong Province. The baseline survey were completed in December 2019, and followup surveys were conducted once every 3 mouths from June 2020 to March 2021. Time-continuous, state-discrete multi-state reversible Markov model was constructed based on the status of MSM's sexual behaviors with different types of sexual partners [anal sex occurred or not (S1=No, S2=Yes) and UAI occurred or not (S1=No,S2=Yes)] to analyze the transition patterns and the influencing factors.Results:A total of 735 MSM were included. The transition intensity of starting anal sex with stable and casual partners was 1.935 times and 0.595 times higher than that of discontinuing this behavior, respectively. While the transition intensity to start UAI with stable and casual partners was 0.430 times and 0.169 times higher than that of discontinuing it, respectively. During the follow-up, the transition probabilities of anal sex and UAI with both stable and casual partners increased first and then stabilized. For stable partners, the transition probability of starting anal sex was higher than that of discontinuing it at the same period, for casual partners, it was just the reverse. For both stable and casual partners, the transition probabilities of discontinuing UAI were higher than starting it at the same time. The results of multivariate analysis showed that participants who received intervention materials ( HR=1.47), had an associate degree ( HR=1.77) or a bachelor's degree and above ( HR=1.47) were at higher risk of starting anal sex with stable partners. Those who received intervention materials ( HR=1.39) were at higher risk of discontinuing anal sex with stable partners, while participants identified themselves as non-male gender ( HR=0.49) were at lower risk of discontinuing anal sex with stable partners. Participants received intervention materials ( HR=1.75) were at higher risk of starting UAI with stable partners. Those who lived apart, divorced, or widowed ( HR=3.22) were at higher risk of starting UAI with casual partners, whereas had a bachelor's degree and above ( HR=0.58) were at lower risk of starting UAI with casual partners. Participants identified themselves as non-male gender ( HR=0.45) at lower risk of discounting UAI with casual partners. Conclusions:The transition patterns of homosexual behavior in MSM are different. Marital status, gender identity, educational level and other factors are the influencing factors of sexual behavior status transitions. Future researches should develop targeted interventions for different types of sexual partners and characteristics of MSM.

Objective:The aim of this study was to explore the risk factors that affect implementation of the innovative technique of single-incision laparoscopic appendectomy (solo-SLA) without assistance in patients with complicated appendicitis, the goal being improving surgical success rates and reducing the incidence of complications.Methods:This was an observational study. Indications for solo-SLA surgery were as follows: (1) computed tomography or ultrasound findings suggestive of acute appendicitis, accompanied by a high white blood cell count and C-reactive protein concentration; (2) disease course exceeding 72 hours, standard anti-infection treatment ineffective, inflammatory reaction not localized, surgery mainly aimed at abscess drainage, and the appendix removed if indicated intraoperatively; (3) acute onset stabilized for more than 3 months after conservative treatment; and (4) recurrent chronic appendicitis. Relative contraindications comprised: (1) cardiopulmonary insufficiency, extremely high risk for general anesthesia for laparoscopic surgery; (2) severe coagulation dysfunction; and (3) imaging findings suggestive of formation of a peri-appendiceal abscess, stable after anti-infection treatment, and a tendency for the inflammatory reaction to localize. We retrospectively collected clinical data of 106 patients with complicated appendicitis who had undergone solo-SLA in the Department of Emergency Surgery, Peking University People's Hospital from February to October 2023. Preoperative computed tomography showed appendiceal fecaliths, blurring of the tissue surrounding fat, intra- and extra-luminal gas and exudate, peri-appendiceal abscess, ascites, and intestinal obstruction by appendicitis. The study cohort comprised 53 male and 53 female patients aged (41.4±17.4) years. The median body mass index was (24.2±3.6) kg/m 2 and median preoperative body temperature (37.3±0.9)℃ Appendicitis had been present for >3 days in 21 of the patients (19.8%) and the maximum diameter of the appendix was (12.4±3.8) mm. The efficacy of the surgery was assessed and logistic regression analysis used to explore the factors affecting the duration of the procedure. The relationship between the maximum diameter of the appendix and duration of surgery was non-linear and was explored using a logistic regression model with restricted cubic spline (RCS). Results:Only one patient required conversion to open surgery; all the other patients successfully completed solo-SLA with a median intraoperative blood loss of 10 (1-100) ml and a surgical time of (65.4±31.7) minutes. Pain scores on postoperative Day 1 and 7 were (3.4±3.2) points and (1.5±1.7) points, respectively. There were no significant postoperative complications .The postoperative hospital stay was (3.5±1.5) days and the interval to resuming normal activities 14 (2-40) days. According to univariate and multivariate analyses, disease course >3 days (OR=5.19, 95%CI: 1.59-16.98, P=0.006) and C-reactive protein >10 mg/L (OR=1.01,95%CI: 1.00-1.02, P=0.003) were independent risk factors for surgical duration >60 minutes, whereas the maximum diameter of the appendix was not independently associated with duration of surgery (OR=1.10, 95%CI: 0.97-1.25, P=0.119). RCS analysis results showed a "U-shaped" association between the maximum diameter of the appendix and duration of surgery, the inflection point of the RCS curve being at a diameter of 10 mm. When the maximum diameter of the appendix was <10 mm, increases in diameter were not associated with longer duration of surgery (OR=1.15,95%CI: 0.55-2.58, P=0.710); whereas when the diameter was ≥10 mm, the maximum diameter of the appendix was associated with increased duration of surgery (OR=1.20, 95% CI: 1.04-1.42, P=0.022). Conclusion:The solo-SLA procedure can be performed to treat complicated appendicitis. A disease course >3 days, C-reactive protein concentration >10 mg/L, and maximum diameter of the appendix ≥10 mm are all associated with greater difficulty of solo-SLA surgery.

Objective This study aimed to investigate the value of PET/CT radiomics combined with machine learning in differentia-ting primary central nervous system lymphoma(PCNSL)from brain metastases(BM).Methods Sixty-nine patients with 127 lesions(including 43 PCNSL lesions and 84 BM lesions)who attended the Department of Nuclear Medicine of Lanzhou University Second Hospi-tal from January 2019 to November 2024 were selected and divided into a training set(n=88)and a validation set(n=39)in a 7∶3 rati-o.Radiomics features of PET and CT were extracted using the 3D slicer,and feature dimensionality reduction was performed using least absolute shrinkage and selection operator(LASSO)regression combined with 5-fold cross-validation to construct three classical machine learning models-Logistic regression(LR),decision tree(DT),and support vector machine(SVM),and the diagnostic efficacy of each model was evaluated using receiver operating characteristic(ROC)curves and confusion matrices.Results The SVM model based on PET imaging performed best in the validation set[area under the curve(AUC)=0.917,sensitivity=84.6％,specificity=92.3％]and was significantly better than the CT model(AUC=0.787,sensitivity=73.1％,specificity=76.9％).Conclusion The support vector machine model constructed based on PET radiomics metabolic features demonstrated high diagnostic value in the preoperative differentia-tion between PCNSL and BM,showing potential for clinical application as a non-invasive auxiliary diagnostic tool.