Epidemiological investigation of a case of severe Chlamydia psittaci pneumonia in Jiujiang / 上海预防医学

To clarify the causal factors of a case with severe Chlamydia psittaci pneumonia in Jiujiang District， Jiangxi Province and provide a scientific basis for effective prevention and control. Basic information and epidemiological data of the case were collected by epidemiological survey， and the samples from the close contacts and environment were collected for pathogen detection. A 37-year-old female patient was admitted to the hospital due to "fever with cough for five days and worsening dyspnea". The results of targeted next-generation sequencing （tNGS） of pathogenic microorganisms in the bronchoalveolar lavage fluid of the case indicated that the patient was infected with Chlamydia psittaci. Our epidemiological investigation revealed a clear history of chicken and duck exposure. Four throat swab samples of close contacts and one spleen， liver and lung sample of sick chicken and duck were collected for testing. One of the duck tissue samples tested positive， while the other samples were negative. The severe pneumonia was likely caused by exposure to the external environment contaminated by Chlamydia psittaci. Poultry farming should be regulated to prevent the transmission infection from poultry to humans．Additionally， awareness among medical staff should be increased to prevent severe outcomes．

Construction and evaluation of risk prediction model for non suicidal self injury of middle school students / 中国学校卫生

Objective@#To construct a nonsuicidal selfinjury (NSSI) risk prediction model for middle school students using different machine learning algorithms and evaluate the models effectiveness, so as to provide guidance for the prevention and control of NSSI in campus.@*Methods@#In March 2023, a total of 3 372 middle and high school students from schools in Nanchang, Fuzhou and Shangrao cities in Jiangxi Province were selected by combining stratified random cluster sampling and convenient sampling methods. Questionnaire surveys were conducted using various instruments including general information questionnaire, Selfesteem Scale, Ottawa Selfinjury Scale, Social Support Assessment Scale, Chinese Version of the Olweus Bullying Questionnaire, Event Attribution Style Scale, Adolescent Resilience Scale, and Adolescent Life Events Scale. Data were divided into training set (n=2 361) and test set (n=1 011) at a ratio of 7∶3, and variables were selected based on univariate and LASSO regression results. Four machine learning algorithms including namely random forest, support vector machine, Logistic regression and XGBoost, were used to construct NSSI risk prediction models, and the models performance was evaluated and compared using metrics including area under curve (AUC), sensitivity, specificity, positive predictive value, negative predictive value and F1 score.@*Results@#The detection rate of NSSI among middle school students was 34.4%. Univariate analysis showed that there were statistically significant differences in NSSI detection rates among middle school students of different grades, genders, registered residence locations, whether they were class cadres and four types of bullying (physical, verbal, relational bullying and cyberbullying) (χ2=27.17, 15.81, 11.54, 4.63；68.22, 140.63, 77.81, 13.95, P<0.05). NSSI was included as the dependent variable in the LASSO regression model for variable screening, and the results regression identified 10 predictive variables including grade level, selfesteem, subjective support, support utilization, verbal bullying, emotional control, interpersonal relationships, punishment, loss of relatives and property, and health and adaptation issues. The AUC values of random forest, support vector machine, Logistic regression, and XGBoost algorithms were 0.76, 0.76, 0.76 and 0.77, respectively, with no statistically significant differences between pairwise comparisons (Z=-0.59-0.82, P>0.05). Sensitivity values were 0.62, 0.61, 0.62 and 0.61, respectively. Specificity values were 0.74, 0.78, 0.78 and 0.78, respectively. Positive predictive values were 0.56, 0.59, 0.60 and 0.59, respectively. Negative predictive values were 0.79, 0.79, 0.80 and 0.79, respectively. F1 scores were 0.59, 0.60, 0.61 and 0.60, respectively.@*Conclusions@#All four nonsuicidal selfinjury risk prediction models perform well, with the Logistic regression model slightly outperforming the others. Schools and parents should pay attention to the predictive factors corresponding to NSSI, so as to reduce the occurrence of NSSI among middle school students.

Effect of dexmedetomidine sedation on perioperative hemodynamics and heart rate variability in the aged patients with cataract operation / 中国医师进修杂志

Objective To investigate the effect of dexmedetomidine sedation on perioperative hemodynamics and heart rate variability (HRV) in the aged patients with cataract operation.Methods Fifty aged patients with cataract who accepted phacoemulsification operation in local anesthesia,were divided into experiment group(dexmedetomidine group) and control group (0.9％ sodium chloride group) by random digits table method with 25 cases each.The experiment group was given local anesthesia,after dexmedetomidine load at 0.5 μg/kg intravenous infusion,dexmedetomidine continuous pumping [0.2-0.3 μg/ (kg ·h)] to maintain the depth of anesthesia.The control group was given the same dose 0.9％ sodium chloride intravenous infusion.Local anesthesia method:2％ lidocaine and 0.75％ bupivacaine 3 ml mixing for retrobulbar anesthesia.The changes of HRV and hemodynamics in the 2 groups before operation (T0),beginning operation (T1),perioperative10min (T2),perioperative30min (T3),postoperative (T4) were recorded,and hemodynamies was analyzed.Results The normalized units of low frequency (LFnu) and low frequency (LF)/high frequency (HF) at T1,T2,T3 in control group were significantly higher than those at T0 [(73.9 ± 9.2)％,(74.5 ± 9.0)％,(75.8 ± 8.5)％ vs.(61.3 ± 7.5)％ and 2.4 ± 1.1,2.6 ± 1.3,2.7 ± 0.9 vs.1.6 ± 0.5],total frequency power (TP) was significantly lower than that at T0 [(1372 ± 419),(915 ± 243),(1389 ± 142) Hz vs.(2351 ± 608) Hz],there were statistical differences (P ＜ 0.05).The LFnu and LF/HF at T1,T2,T3 in experiment group were higher than those at T0,but there were no statistical differences (P ＞0.05).The TP at T1,T2,T3 in experiment group was significantly lower than that at T0 [(1458 ± 325),(983 ±272),(1497 ± 210) Hz vs.(2235 ± 513) Hz],there was statistical difference (P ＜ 0.05).There was no statistical difference in normalized units of HF at all time points between the 2 groups (P ＞ 0.05).The LFnu,LF/HF and TP at T1,T2,T3 in experiment group were better than those in control group,there were statistical differences (P ＜ 0.05).The fluctuation of hemodynamics in experiment group was significantly lower than that in control group,there was statistical difference (P ＜ 0.05).Conclusion Dexmedetomidine sedation little effects on HRV during perioperative period in aged patients with cataract operation,can significantly reduce the influence of operation stimulation on autonomic nervous system and hemodynamics.