OBJECTIVE To explore the risk factors for polymyxin-and carbapenem-resistant Klebsiella pneumoni-ae(PR-CRKP)infection and establish the prediction model.METHODS The clinical data were retrospectively col-lected from the patients with CRKP infection who were treated in the First Affiliated Hospital of Xi'an Jiaotong University from Jan.2023 to Mar.2024.The enrolled patients were divided into the CRKP group and the PR-CRKP group according to the result of drug susceptibility testing for polymyxin B.Totally 203 patients who were treated from Jan.2023 to Dec.2023 were assigned as the modeling group,and 91 patients who were treated from Jan.2024 to Mar.2024 were assigned as the validation group.Multivariate logistic regression analysis was per-formed for the risk factors for PR-CRKP infection,nomogram was built up for prediction of PR-CRKP infection by R software,and the predictive efficacy of the model was evaluated by means of receiver operating characteristic(ROC)curves.RESULTS The result of univariate analysis showed that the proportions of patients who received fi-berobronchoscopy,endotracheal intubation/tracheotomy,were complicated with other carbapenem-resistant or-ganisms(CROs)infections,bloodstream infections,were treated in intensive care unit(ICU)and had the history of exposure to polymyxins and carbapenems 3 months before the admission were higher in the PR-CRKP group than in the CRKP group(P＜0.05);the length of hospital stay and duration of use of polymyxins and carbapene-ms were longer in the PR-CRKP group than in the CRKP group(P＜0.05).Multivariate logistic regression analy-sis indicated that complication with other CROs infections,history of exposure to polymyxins and carbapenems 3 months before the admission,duration of use of polymyxins and ICU stay were the risk factors for the PR-CRKP infection(P＜0.05).The area under the curve(AUC)of the predictive model was 0.898 in the modeling group,with the sensitivity 80.33％,the specificity 84.51％.ROC curve analysis showed that the AUC was 0.901 in the validation group,with the sensitivity 75.00％,the specificity 92.73％.CONCLUSION The prediction model that is established based on the result of multivariate analysis has high value in prediction of PR-CRKP infection.

OBJECTIVE To investigate the risk factors for carbapenem-resistant gram-negative bacteria(GNB)bloodstream infection(BSI)in patients with hematological malignancies(HMs)and their prognosis,and to devel-op a nomogram prediction model.METHODS A total of 316 patients with HMs and GNB-BSI admitted to the First Affiliated Hospital of Xi'an Jiaotong University from Jan.2017 to Dec.2022 were selected as the training set,and 106 patients admitted from Jan.2023 to Oct.2024 were selected as the validation set.Variables were selected by lasso regression and multifactor logistic regression,and a nomogram model was constructed.The prediction model was internally validated by the receiver operating characteristic(ROC)curve,calibration curve and decision curve analysis(DCA),respectively.RESULTS Granulocytopenia for ≥7 days(OR=14.525),use of cephalosporins/β-lactamase inhibitors within 30 days before BSI(OR=3.510),exposure history of carbapenem antibacterial drug(OR=4.840)and albumin＜30 g/L(OR=2.697)were risk factors for CR-GNB BSI in patients with HMs(P＜0.05).Septic shock(OR=6.934),central venous catheterization(OR=5.586),inappropriate empirical antibac-terial drug therapy(OR=4.744),CR-GNB infection(OR=2.916)and albumin＜30 g/L(OR=3.324)were risk factors for 30-day mortality in patients with HMs and GNB-BSI(P＜0.05).Based on these indicators,two nomogram models were constructed.The areas under the ROC curve(AUC)for the internal validation set were 0.775 and 0.849,respectively.The calibration curves demonstrated high predictive performance for the pre-diction models(P=0.998 and 0.660,respectively),and DCA showed high clinical application value for both models.CONCLUSION The nomogram prediction model constructed in this study based on multifactor analy-sis not only demonstrates good predictive value but also exhibits significant clinical efficacy,aiding in the early i-dentification of high-risk patients for targeted therapy.

OBJECTIVE To investigate the risk factors for carbapenem-resistant gram-negative bacteria(GNB)bloodstream infection(BSI)in patients with hematological malignancies(HMs)and their prognosis,and to devel-op a nomogram prediction model.METHODS A total of 316 patients with HMs and GNB-BSI admitted to the First Affiliated Hospital of Xi'an Jiaotong University from Jan.2017 to Dec.2022 were selected as the training set,and 106 patients admitted from Jan.2023 to Oct.2024 were selected as the validation set.Variables were selected by lasso regression and multifactor logistic regression,and a nomogram model was constructed.The prediction model was internally validated by the receiver operating characteristic(ROC)curve,calibration curve and decision curve analysis(DCA),respectively.RESULTS Granulocytopenia for ≥7 days(OR=14.525),use of cephalosporins/β-lactamase inhibitors within 30 days before BSI(OR=3.510),exposure history of carbapenem antibacterial drug(OR=4.840)and albumin＜30 g/L(OR=2.697)were risk factors for CR-GNB BSI in patients with HMs(P＜0.05).Septic shock(OR=6.934),central venous catheterization(OR=5.586),inappropriate empirical antibac-terial drug therapy(OR=4.744),CR-GNB infection(OR=2.916)and albumin＜30 g/L(OR=3.324)were risk factors for 30-day mortality in patients with HMs and GNB-BSI(P＜0.05).Based on these indicators,two nomogram models were constructed.The areas under the ROC curve(AUC)for the internal validation set were 0.775 and 0.849,respectively.The calibration curves demonstrated high predictive performance for the pre-diction models(P=0.998 and 0.660,respectively),and DCA showed high clinical application value for both models.CONCLUSION The nomogram prediction model constructed in this study based on multifactor analy-sis not only demonstrates good predictive value but also exhibits significant clinical efficacy,aiding in the early i-dentification of high-risk patients for targeted therapy.

OBJECTIVE To explore the risk factors for polymyxin-and carbapenem-resistant Klebsiella pneumoni-ae(PR-CRKP)infection and establish the prediction model.METHODS The clinical data were retrospectively col-lected from the patients with CRKP infection who were treated in the First Affiliated Hospital of Xi'an Jiaotong University from Jan.2023 to Mar.2024.The enrolled patients were divided into the CRKP group and the PR-CRKP group according to the result of drug susceptibility testing for polymyxin B.Totally 203 patients who were treated from Jan.2023 to Dec.2023 were assigned as the modeling group,and 91 patients who were treated from Jan.2024 to Mar.2024 were assigned as the validation group.Multivariate logistic regression analysis was per-formed for the risk factors for PR-CRKP infection,nomogram was built up for prediction of PR-CRKP infection by R software,and the predictive efficacy of the model was evaluated by means of receiver operating characteristic(ROC)curves.RESULTS The result of univariate analysis showed that the proportions of patients who received fi-berobronchoscopy,endotracheal intubation/tracheotomy,were complicated with other carbapenem-resistant or-ganisms(CROs)infections,bloodstream infections,were treated in intensive care unit(ICU)and had the history of exposure to polymyxins and carbapenems 3 months before the admission were higher in the PR-CRKP group than in the CRKP group(P＜0.05);the length of hospital stay and duration of use of polymyxins and carbapene-ms were longer in the PR-CRKP group than in the CRKP group(P＜0.05).Multivariate logistic regression analy-sis indicated that complication with other CROs infections,history of exposure to polymyxins and carbapenems 3 months before the admission,duration of use of polymyxins and ICU stay were the risk factors for the PR-CRKP infection(P＜0.05).The area under the curve(AUC)of the predictive model was 0.898 in the modeling group,with the sensitivity 80.33％,the specificity 84.51％.ROC curve analysis showed that the AUC was 0.901 in the validation group,with the sensitivity 75.00％,the specificity 92.73％.CONCLUSION The prediction model that is established based on the result of multivariate analysis has high value in prediction of PR-CRKP infection.

Objective To investigate the distribution and antimicrobial resistance of clinical isolates in the First Affiliated Hospital of Xi'an Jiaotong University in 2022 for rational use of antibiotics in clinical practice.Methods Nonduplicate clinical isolates were collected from January 1,2022 to December 31,2022.Antimicrobial susceptibility testing was carried out using Kirby-Bauer method and automated systems.The data were analyzed using WHONET 5.6 software and interpreted according to the Clinical and Laboratory Standards Institute(CLSI)breakpoints(2021 Edition).Results Of the 8 638 clinical isolates,gram negative bacteria and gram positive bacteria accounted for 60.8％(5 253/8 638)and 39.2％(3 385/8 638),respectively.The prevalence of methicillin-resistant strains was 33.0％in S.aureus(MRSA),75.8％in S.epidermidis(MRSE),and 51.9％in other coagulase-negative Staphylococcus(MRCNS).No staphylococcal strains were found resistant to vancomycin.The prevalence of vancomycin-resistant E.faecium was 0.6％,and no vancomycin-resistant E.faecalis was found.E.faecalis strains showed higher resistance rate to linezolid(5.2％)than E.faecium(0.7％).The prevalence of carbapenem-resistant Enterobacterales(CRE)was 7.9％,specifically 12.1％for carbapenem-resistant K.pneumoniae(CRKP)and 1.6％for carbapenem-resistant E.coli(CREC).The prevalence of carbapenem-resistant P.aeruginosa(CRPA)and carbapenem-resistant A.baumannii(CRAB)was 30.9％and 77.0％,respectively.Conclusions Clinical microbiology laboratories should strengthen the collection and testing of clinical specimens from the sites of infection in order to improve pathogenic diagnosis and antimicrobial resistance surveillance.This is conducive to the rational use of antibiotics and reduce the further spread of multidrug-resistant bacteria.

Objective To establish a quality control method for detecting impurities in chloral hydrate raw materials, improve the quality standards and control limits of raw materials. Methods The determination methods of chloroform and halogenated carboxylic acid in chloral hydrate were established to monitor the change of impurities in chloral hydrate through stability. Results The research and establishment of chloroform and halogenated carboxylic acid methods met the requirements of relevant regulations for analytical methodology verification, which could accurately detect four impurities in raw materials and preparations by one method. Conclusion The study provides technical support for the improvement and optimization of the quality standards of chloral hydrate and preparations. It is very necessary to implement the impurity monitoring in preparation research and production process by the chloral hydrate impurity detection and the stability comparison of this product at high temperature and light, which could largely promote the safety of medication.

Objective In order to solve the obvious adverse reactions of ribavirin, to develop ribavirin liposome inhalation powder and to evaluate its quality characteristics. Methods The ribavirin liposomes were prepared by the thin film dispersion method, and then lyophilized to prepare ribavirin liposome powder. The appearance, fluidity, bulk density, encapsulation efficiency, particle size of the complex solution, PDI, potential and hydrophilicity were examined. Results Ribavirin liposome powder has good morphology, particle size, potential, fluidity and hydrophilicity, which can meet the basic requirements of powder medicine for drug administration. Conclusion The technique of preparing ribavirin liposome powder aerosol preparation by this method is feasible, and it provides the basic technology for future in vivo and in vitro studies.

Objective To investigate the diagnostic value of serum anti-Müllerian hormone combined with sex hormones for polycystic ovary syndrome ( PCOS).Methods The serum levels of anti-Müllerian hormone ( AMH), testosterone ( T), luteinizing hormone ( LH), follicle-stimulating hormone (FSH) and the estradiol ( E2) were measured by electrochemiluminescence method in 82 patients with PCOS and 60 controls. The sensitivities, specificities and the areas under the receiver operating characteristic curves ( ROC-AUC) of the indicators and their combination for diagnosis of PCOS were compared by chi-square test and Z test separately.The correlations of serum AMH levels with age and sex hormones levels were analyzed separately by Spearman correlation analysis .Results The levels of serum AMH, T, LH and LH/FSH ratio in patients with PCOS were obviously higher than those in controls (62.19 pmol/L vs 27.63 pmol/L, 1.39 nmol/L vs 0.88 nmol/L, 12.72 IU/L vs 6.44 IU/L, 2.17 vs 1.17, U＝592.00, 1 096.00, 1 233.50, 1 134.00, all P＜0.01).The sensitivity of AMH (80.5%, 66/82) for diagnosis of PCOS was higher than that of LH (62.2%, 51/82) and LH/FSH ratio (54.9%, 45/82, χ2＝5.6, 13.79, all P＜0.05), but no significant difference was found when comparing with T (72%, 59/82, χ2＝1.71, P＞0.05 ) .The sensitivity of AMH ( 80.5%, 66/82 ) increased when combined with T (89.0%, 73/82), LH (87.8%, 72/82) and T+LH (95.10%, 78/82, χ2＝5.14, 4.17, 10.08, all P＜0.05), but no significant change by the combination of AMH +LH/FSH (85.4%, 70/82, χ2＝2.25, P＞0.05) .The specificity of AMH (80%, 48/60) for diagnosis of PCOS was no significant difference compared with that of T (71.7%, 43/60), LH (85%, 51/60), and LH/FSH ratio (91.7%, 55/60) (χ2＝3.20, 0.36, 2.77, all P＞0.05) .Also no increase when combined with T (71.7%, 43/60), LH (73.3%, 44/60), LH/FSH (75%, 45/60) and T +LH (66.7%, 40/60, χ2＝3.20, 2.25, 1.33, 3.38, all P＞0.05).The ROC-AUC of multiple indicators for diagnosis of PCOS were compared , AMH (0.880) was higher than T, LH and LH/FSH ratio (0.778, 0.760, 0.778, Z＝2.12, 2.46, 2.12, all P＜0.05), but no significant differences were found comparing with AMH and the combination of AMH +T, AMH+LH, AMH+LH/FSH and AMH+T+LH (0.892, 0.897, 0.898, 0.902, Z＝0.31, 0.45, 0.48, 0.59, all P＞0.05).Serum AMH levels were positively correlated with T , LH levels and LH/FSH ratio (r＝0.258, 0.241, 0.290, all P＜0.05), but not correlated with age in PCOS group (r＝-0.178, P＞0.05).In the control group, AMH levels had no correlations with T, LH levels and LH/FSH ratio (r＝0.025, 0.104, 0.111, P＞0.05), while negatively correlated with age (r＝-0.307, P＜0.05).The cutoff value of AMH for diagnosis of PCOS decreased with age .Conclusions The sensitivity of AMH for diagnosis of PCOS was higher than that of LH and LH /FSH ratio, and the sensitivity could be further improved by the combination with T or /and LH without reducing the specificity .Age-stratified cut-off values of AMH were better for accurate diagnosis of PCOS.