BACKGROUND:We have successfully established an animal model of small ear pig in southern Yunnan province with internal tension relieving technique combined with autologous Achilles tendon for anterior cruciate ligament reconstruction,and verified the stability and reliability of the model.However,whether internal tension relieving technique can promote the ligamentalization process of autologous Achilles tendon graft has not been studied. OBJECTIVE:To investigate the differences in the process of ligamentalization between conventional reconstruction and internal reduction reconstruction of the anterior cruciate ligament by gross view,histology and electron microscopy. METHODS:Thirty adult female small ear pigs in southern Yunnan province were selected.Anterior cruciate ligament reconstruction was performed on the left knee joint with the ipsilateral knee Achilles tendon(n=30 in the normal group),and anterior cruciate ligament reconstruction was performed on the right knee joint with the ipsilateral knee Achilles tendon combined with the internal relaxation and enhancement system(n=30 in the relaxation group).The autogenous right forelimb was used as the control group;the anterior cruciate ligament was exposed but not severed or surgically treated.At 12,24,and 48 weeks after surgery,10 animals were sacrificed,respectively.The left and right knee joint specimens were taken for gross morphological observation to evaluate the graft morphology.MAS score was used to evaluate the excellent and good rate of the ligament at each time point.Hematoxylin-eosin staining was used to evaluate the degree of ligament graft vascularization.Collagen fibers and nuclear morphology were observed,and nuclear morphology was scored.Ultrastructural remodeling was evaluated by scanning electron microscopy and transmission electron microscopy. RESULTS AND CONCLUSION:(1)The ligament healing shape of the relaxation group was better at various time points after surgery,and the excellent and good rate of MAS score was higher(P<0.05).Moreover,the relaxation group could obtain higher ligament vascularization score(P<0.05).(2)The arrangement of collagen bundles and fiber bundles in the two groups gradually tended to be orderly,and the transverse fiber connections between collagen gradually increased and thickened,suggesting that the strength and shape degree of the grafts were gradually improved,but the ligament remodeling in the relaxation group was always faster than that in the normal group at various time points after surgery.(3)The diameter,distribution density,and arrangement degree of collagen fibers in the relaxation group were better than those in the normal group at all time points,especially in the comparison of collagen fiber diameter between and within the relaxation group(P<0.05).

Objective:To investigate the application of the parameters of multimodal ultrasound elastography in differential diagnosis for thyroid nodules of patients with diffuse thyroid lesions.Methods:A total of 103 patients with diffuse thyroid lesions who underwent treatment at Affiliated Baoji Hospital of Xi′an Medical University from January 2023 to January 2024 were retrospectively selected,whose thyroid nodules were confirmed by fine needle aspiration biopsy or surgical pathology.They were grouped according to the benign or malignant nodules.56 patients with benign nodules were included in the benign nodule group,while the other 47 patients were included in the malignant nodule group.All patients were examined by conventional ultrasound and multimodal ultrasound elastography,and the relevant parameters were recorded to compare the differences between the two groups.The value of each indicator in diagnosing benign and malignant thyroid nodules was investigated.Results:There were no statistically significant differences between the benign and malignant nodule groups in terms of gender,length diameter of nodule,nodule location,functional abnormalities of thyroid,exposure history of radiation,and the presence of acoustic halos(P＞0.05),the age of patients in the malignant nodule group was lower than that of the benign nodule group(t=-3.121,P＜0.05),and the percentage of nodules with blood flow(14.89%),the percentage of aspect ratio＜1(74.47%),and the percentage of nodules with clear boundary(27.66%)in the malignant nodule group were all lower than those of the benign nodule group,with statistically significant differences(x2=25.634,5.112,12.465,P＜0.05).The ratio of lymphatic metastasis(27.66%)and that of calcification(65.96%)in the malignant nodule group were lower than those in the benign nodule group,and the differences were all statistically significant(x2=11.917,9.350,P＜0.05).The ratios of centripetal enhancement(76.60%),inhomogeneous enhancement(68.09%),low/equal enhancement(87.23%),early obvious discharge(63.83%),unclear boundary after enhancement(91.49%),and fast discharge(59.57%)in the malignant nodule group were higher than that of the benign nodule group,and the differences were statistically significant(x2=33.409,26.695,9.079,12.853,17.798,12.649,P＜0.05),respectively.The intensity and time to peak of the malignant nodule group were respectively lower and long than these of the benign nodule group,and the differences were statistically significant(t=-12.381,4.958,P＜0.05).However,the mean passage time of the two groups was not statistically significant(P＞0.05).The maximum value,minimum value and mean value of Young's modulus,the maximum value of vertical section,mean value of vertical section,maximum value of cross section,mean value of cross section in the malignant nodule group were all higher than those in the benign nodule group,and the differences were statistically significant(t=13.997,9.100,12.191,7.616,6.310,4.679,5.355,P＜0.05).The result of receiver operating characteristic(ROC)curve analysis indicated that both ultrasonography parameters and shear wave elastography(SWE)parameters had higher diagnostic value for the benign and malignant nature of thyroid nodules in patients.The area under curve(AUC)values of intensity to peak,time to peak,and the maximum value,minimum value and mean value of Young's modulus,and the maximum value of vertical section,mean value of vertical section,maximum value of cross section,mean value of cross section were respectively 0.976,0.759,0.974,0.837,0.989,0.872,0.805,0.732 and 0.749.Conclusion:Multimodal ultrasound elastography parameters has significant application value in differential diagnosis for thyroid nodules in patients with diffuse thyroid lesions.In these parameters,the diagnostic AUC values of intensity to peak,time to peak,and the maximum value and mean value of Young's modulus are higher for malignant thyroid nodules of patients,which have higher diagnostic efficiency.It can effectively help clinical doctor to accurately identify the benign and malignant nodules for patients with diffuse thyroid lesions.

Objective:To investigate the application of the parameters of multimodal ultrasound elastography in differential diagnosis for thyroid nodules of patients with diffuse thyroid lesions.Methods:A total of 103 patients with diffuse thyroid lesions who underwent treatment at Affiliated Baoji Hospital of Xi′an Medical University from January 2023 to January 2024 were retrospectively selected,whose thyroid nodules were confirmed by fine needle aspiration biopsy or surgical pathology.They were grouped according to the benign or malignant nodules.56 patients with benign nodules were included in the benign nodule group,while the other 47 patients were included in the malignant nodule group.All patients were examined by conventional ultrasound and multimodal ultrasound elastography,and the relevant parameters were recorded to compare the differences between the two groups.The value of each indicator in diagnosing benign and malignant thyroid nodules was investigated.Results:There were no statistically significant differences between the benign and malignant nodule groups in terms of gender,length diameter of nodule,nodule location,functional abnormalities of thyroid,exposure history of radiation,and the presence of acoustic halos(P＞0.05),the age of patients in the malignant nodule group was lower than that of the benign nodule group(t=-3.121,P＜0.05),and the percentage of nodules with blood flow(14.89%),the percentage of aspect ratio＜1(74.47%),and the percentage of nodules with clear boundary(27.66%)in the malignant nodule group were all lower than those of the benign nodule group,with statistically significant differences(x2=25.634,5.112,12.465,P＜0.05).The ratio of lymphatic metastasis(27.66%)and that of calcification(65.96%)in the malignant nodule group were lower than those in the benign nodule group,and the differences were all statistically significant(x2=11.917,9.350,P＜0.05).The ratios of centripetal enhancement(76.60%),inhomogeneous enhancement(68.09%),low/equal enhancement(87.23%),early obvious discharge(63.83%),unclear boundary after enhancement(91.49%),and fast discharge(59.57%)in the malignant nodule group were higher than that of the benign nodule group,and the differences were statistically significant(x2=33.409,26.695,9.079,12.853,17.798,12.649,P＜0.05),respectively.The intensity and time to peak of the malignant nodule group were respectively lower and long than these of the benign nodule group,and the differences were statistically significant(t=-12.381,4.958,P＜0.05).However,the mean passage time of the two groups was not statistically significant(P＞0.05).The maximum value,minimum value and mean value of Young's modulus,the maximum value of vertical section,mean value of vertical section,maximum value of cross section,mean value of cross section in the malignant nodule group were all higher than those in the benign nodule group,and the differences were statistically significant(t=13.997,9.100,12.191,7.616,6.310,4.679,5.355,P＜0.05).The result of receiver operating characteristic(ROC)curve analysis indicated that both ultrasonography parameters and shear wave elastography(SWE)parameters had higher diagnostic value for the benign and malignant nature of thyroid nodules in patients.The area under curve(AUC)values of intensity to peak,time to peak,and the maximum value,minimum value and mean value of Young's modulus,and the maximum value of vertical section,mean value of vertical section,maximum value of cross section,mean value of cross section were respectively 0.976,0.759,0.974,0.837,0.989,0.872,0.805,0.732 and 0.749.Conclusion:Multimodal ultrasound elastography parameters has significant application value in differential diagnosis for thyroid nodules in patients with diffuse thyroid lesions.In these parameters,the diagnostic AUC values of intensity to peak,time to peak,and the maximum value and mean value of Young's modulus are higher for malignant thyroid nodules of patients,which have higher diagnostic efficiency.It can effectively help clinical doctor to accurately identify the benign and malignant nodules for patients with diffuse thyroid lesions.

Objective:To explore the application value of Superb microvascular imaging(SMI)technique in diagnosing diffuse thyroid disease with thyroid nodules,and the assessment for treatment efficacy.Methods:A total of 100 patients with diffuse thyroid disease with thyroid nodules(132 nodules),who were treated at the Baoji Hospital Affiliated to Xi'an Medical University from March 2020 to November 2024,were selected.The dual examination of SMI and conventional Color Doppler Flow Imaging(CDFI)were conducted on them.The nature of the nodules was confirmed by pathological examination.The diagnostic sensitivity,specificity and predictive value of SMI and CDFI were analyzed by using the receiver operating characteristic(ROC)curve.A series of conventional indicators,including blood flow volume,blood flow velocity,pattern of blood flow distribution,and vascular morphology,between the two imaging techniques were compared and analyzed.Results:In the 132 thyroid nodules that were detected by pathological examination,SMI identified 94 benign lesions(71.21%)and 38 malignant lesions(28.79%).The sensitivity and specificity of SMI were respectively 94.68%and 89.47%in diagnosing diffuse thyroid disease with thyroid nodules,both of them were higher than those(84.05%and 78.95%)of CDFI,and the sensitivity of SMI diagnosis was significantly higher than that of CDFI diagnosis,and the difference was statistically significant(x2=5.595,P<0.05).The nodule size as SMI diagnosis was(14.62±2.36)mm,which was significantly smaller than(16.35±4.45)mm as CDFI diagnosis,and the difference was statistically significant(x2=3.330,P<0.05).Blood flow velocity and blood flow volume of SMI diagnosis were significantly higher than those of CDFI diagnosis,and the differences were statistically significant(t=5.718,6.567,P<0.05).The detection rates of blood flow distribution mode and vascular morphology of SMI mode were significantly higher than those of CDFI mode,and the differences were statistically significant(x2=9.192,4.776,P<0.05).However,there were not statistically significant differences were observed between the two imaging techniques in terms of the shape,echo type and internal calcification of nodules(P>0.05).Conclusion:SMI technique has a significant advantage in diagnosis and assessment for diffuse thyroid disease with thyroid nodules.It can more accurately assess the hemodynamic changes of the nodules,and provide more reliable diagnostic information for clinical treatment.

Objective:To analyze the value advantages of multimodal ultrasound in the diagnosis of benign and malignant nodules of 4a grade of nodules of Chinese thyroid imaging reporting and data system (C-TIRADS) of diffuse thyroid nodules. Methods:A total of 227 diffuse thyroid nodules (116 malignant nodules and 111 benign nodules) from 219 patients who admitted to Baoji Hospital Affiliated to Xi'an Medical University between January 2020 to December 2023 were retrospectively selected. Two-dimensional ultrasound and multimodal ultrasound were used to diagnose diffuse thyroid nodules,and to perform data analysis. There were 49 males and 170 females,ranging in age from 24 to 72 years old,whose average age was 52.31±10.08 years. The result of pathological diagnosis was used as the "gold standard",and the results of pathological diagnosis and the parameters of multimodal ultrasound for diffuse thyroid nodules were compared. The diagnostic efficiency of the results of multimodal ultrasound and two-dimensional ultrasound for diffuse thyroid nodules was compared and analyzed. Results:As the results of pathological diagnosis,the scores of contrast-enhanced ultrasound,micro blood flow imaging,elastography and malignant risk score of multimodal ultrasound technique of malignant diffuse thyroid nodules were significantly higher than those of benign nodules (Z=-4.258,-5.007,-5.631,P<0.05),respectively. The sensitivity (92.24％) and specificity (92.79％) of multimodal ultrasound were significantly higher than those (75.00％ and 83.78％) of two-dimensional ultrasound (x2=12.588,4.356,P<0.05),respectively. The positively predictive values (93.04％) and negatively predictive values (91.96％) of multimodal ultrasound were significantly higher than those (82.86％ and 76.23％) of two-dimensional ultrasound (x2=5.465,10.629,P<0.05),respectively. Conclusion:For the judgment of benign and malignant nodules of C-TIRADS 4a in the background of diffuse thyroid nodules,the application of multimodal ultrasound technique,especially the combined use of contrast-enhanced ultrasound,elastography and micro blood flow imaging,can greatly improve the accuracy of ultrasonic diagnosis of these diseases.

Objective To investigate the distribution and antimicrobial resistance profiles of common pathogens isolated from cerebrospinal fluid(CSF)in CHINET program from 2015 to 2021.Methods The bacterial strains isolated from CSF were identified in accordance with clinical microbiology practice standards.Antimicrobial susceptibility test was conducted using Kirby-Bauer method and automated systems per the unified CHINET protocol.Results A total of 14 014 bacterial strains were isolated from CSF samples from 2015 to 2021,including the strains isolated from inpatients(95.3％)and from outpatient and emergency care patients(4.7％).Overall,19.6％of the isolates were from children and 80.4％were from adults.Gram-positive and Gram-negative bacteria accounted for 68.0％and 32.0％,respectively.Coagulase negative Staphylococcus accounted for 73.0％of the total Gram-positive bacterial isolates.The prevalence of MRSA was 38.2％in children and 45.6％in adults.The prevalence of MRCNS was 67.6％in adults and 69.5％in children.A small number of vancomycin-resistant Enterococcus faecium(2.2％)and linezolid-resistant Enterococcus faecalis(3.1％)were isolated from adult patients.The resistance rates of Escherichia coli and Klebsiella pneumoniae to ceftriaxone were 52.2％and 76.4％in children,70.5％and 63.5％in adults.The prevalence of carbapenem-resistant E.coli and K.pneumoniae(CRKP)was 1.3％and 47.7％in children,6.4％and 47.9％in adults.The prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)and Pseudomonas aeruginosa(CRPA)was 74.0％and 37.1％in children,81.7％and 39.9％in adults.Conclusions The data derived from antimicrobial resistance surveillance are crucial for clinicians to make evidence-based decisions regarding antibiotic therapy.Attention should be paid to the Gram-negative bacteria,especially CRKP and CRAB in central nervous system(CNS)infections.Ongoing antimicrobial resistance surveillance is helpful for optimizing antibiotic use in CNS infections.

Objective To investigate the antimicrobial resistance of clinical isolates from elderly patients(≥65 years)in major medical institutions across China.Methods Bacterial strains were isolated from elderly patients in 52 hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program during the period from 2015 to 2021.Antimicrobial susceptibility test was carried out by disk diffusion method and automated systems according to the same CHINET protocol.The data were interpreted in accordance with the breakpoints recommended by the Clinical and Laboratory Standards Institute(CLSI)in 2021.Results A total of 514 715 nonduplicate clinical isolates were collected from elderly patients in 52 hospitals from January 1,2015 to December 31,2021.The number of isolates accounted for 34.3％of the total number of clinical isolates from all patients.Overall,21.8％of the 514 715 strains were gram-positive bacteria,and 78.2％were gram-negative bacteria.Majority(90.9％)of the strains were isolated from inpatients.About 42.9％of the strains were isolated from respiratory specimens,and 22.9％were isolated from urine.More than half(60.7％)of the strains were isolated from male patients,and 39.3％isolated from females.About 51.1％of the strains were isolated from patients aged 65-＜75 years.The prevalence of methicillin-resistant strains(MRSA)was 38.8％in 32 190 strains of Staphylococcus aureus.No vancomycin-or linezolid-resistant strains were found.The resistance rate of E.faecalis to most antibiotics was significantly lower than that of Enterococcus faecium,but a few vancomycin-resistant strains(0.2％,1.5％)and linezolid-resistant strains(3.4％,0.3％)were found in E.faecalis and E.faecium.The prevalence of penicillin-susceptible S.pneumoniae(PSSP),penicillin-intermediate S.pneumoniae(PISP),and penicillin-resistant S.pneumoniae(PRSP)was 94.3％,4.0％,and 1.7％in nonmeningitis S.pneumoniae isolates.The resistance rates of Klebsiella spp.(Klebsiella pneumoniae 93.2％)to imipenem and meropenem were 20.9％and 22.3％,respectively.Other Enterobacterales species were highly sensitive to carbapenem antibiotics.Only 1.7％-7.8％of other Enterobacterales strains were resistant to carbapenems.The resistance rates of Acinetobacter spp.(Acinetobacter baumannii 90.6％)to imipenem and meropenem were 68.4％and 70.6％respectively,while 28.5％and 24.3％of P.aeruginosa strains were resistant to imipenem and meropenem,respectively.Conclusions The number of clinical isolates from elderly patients is increasing year by year,especially in the 65-＜75 age group.Respiratory tract isolates were more prevalent in male elderly patients,and urinary tract isolates were more prevalent in female elderly patients.Klebsiella isolates were increasingly resistant to multiple antimicrobial agents,especially carbapenems.Antimicrobial resistance surveillance is helpful for accurate empirical antimicrobial therapy in elderly patients.

Objective To examine the changing prevalence and antimicrobial resistance profiles of Burkholderia cepacia in 52 hospitals across China from 2015 to 2021.Methods A total of 9 261 strains of B.cepacia were collected from 52 hospitals between January 1,2015 and December 31,2021.Antimicrobial susceptibility of the strains was tested using Kirby-Bauer method or automated antimicrobial susceptibility testing systems according to a unified protocol.The results were interpreted according to the breakpoints released in the Clinical & Laboratory Standards Institute(CLSI)guidelines(2023 edition).Results A total of 9 261 strains of B.cepacia were isolated from all age groups,especially elderly patients.The proportion was 11.1％(1 032 strains)in children,significantly lower than the proportion in adults.About half(46.5％,4 310/9 261)of the strains were isolated from patients at least 60 years old and 42.3％(3 919/9 261)of the strains were isolated from young adults.Most isolates(71.1％)were isolated from sputum and respiratory secretions,followed by urine(10.7％)and blood samples(8.1％).B.cepacia isolates were highly susceptible to the five antimicrobial agents recommended in the CLSI M100 document(33rd edition,2023).B.cepacia isolates showed relatively higher resistance rates to meropenem and levofloxacin.However,the resistance rates to ceftazidime,trimethoprim-sulfamethoxazole,and minocycline remained below 8.1％.The percentage of B.cepacia strains resistant to levofloxacin was the highest compared to other antibiotics in any of the three age groups(from 12.4％in the patients＜18 years old to 20.6％in the patients aged 60 years or older).Conclusions B.cepacia is one of the clinically important non-fermenting gram-negative bacteria.Accurate and timely reporting of antimicrobial susceptibility test results and ongoing antimicrobial resistance surveillance are helpful for rational prescription of antimicrobial agents and proper prevention and control of nosocomial infections.

Objective To explore the predictive value of automated breast ultrasound(ABUS)features combined with Ki-67 in predicting pathological complete response(pCR)after neoadjuvant chemotherapy(NAC)in triple-negative breast cancer(TNBC).Methods A retrospective analysis was conducted on 127 female TNBC patients treated at Xijing Hospital,Air Force Medical University from March 2019 to December 2023.All patients underwent NAC and surgical treatment after ABUS examination.Based on postoperative pathological results,patients were divided into pCR group(n=60)and non-pathological complete response(npCR)group(n=67).Differences in various parameters before NAC were compared between the two groups.LASSO regression was used to identify independent factors influencing pCR after NAC in TNBC patients,and a predictive model was constructed using multivariate logistic regression.The prediction model was internally validated using the Bootstrap method(1000 resamples).The discriminative ability of the model was evaluated using receiver operating characteristic(ROC)curves,and the area under the curves(AUCs)of different prediction models were compared using De-long's test.The accuracy of the model was assessed using calibration curves,and the clinical benefit of the model was evaluated using clinical decision curve analysis(DCA).Results Significant differences were observed between two groups in terms of age,Ki-67,menopausal status,tumor type,posterior echo,coronal plane convergence sign,coronal plane skip sign,and coronal plane white wall sign before NAC(P<0.05).LASSO regression analysis showed that Ki-67,coronal plane convergence sign,and coronal plane white wall sign were independent influencing factors of pCR after NAC in TNBC patients(P<0.05).The AUC of the multivariate logistic regression model based on Ki-67 was 0.733(95%CI 0.646-0.819),the AUC of ABUS model was 0.777(95%CI 0.695-0.858),and the AUC of ABUS combined with Ki-67 model was 0.816(95%CI 0.741-0.890).De-long's test showed that the AUC of the combined model was higher than those of ABUS feature model and Ki-67 model,with statistically significant differences(P<0.05).There was no significant difference in the AUC between ABUS feature model and Ki-67 model(P=0.40).Hosmer-Lemeshow test indicated that the combined model had a good fit(P=0.304).Internal validation results showed that the combined model had a good stability with a consistency index(C-index)of 0.820(95%CI 0.726-0.879).The calibration curve demonstrated good consistency between the predicted and actual probabilities of the combined prediction model,and the DCA curve indicated that the model had favorable clinical benefit.Conclusion The combined ABUS feature and Ki-67 model can be used to predict the probability of pCR after NAC in TNBC patients,providing a reference for the formulation of clinical treatment plans in TNBC patients.

Objective To develop a predictive model for postoperative mortality risk in patients with acute aortic dissection(AAD)using the Extreme Gradient Boosting(XGBoost)algorithm combined with Shapley Additive Explanation(SHAP),and to establish a prediction website to serve as a diagnostic and therapeutic support platform for clinicians and patients.Methods A retrospective cohort study design was adopted.Data from 782 AAD patients who underwent surgical treatment at the Fourth Hospital of Hebei Medical University from January 2013 to December 2023 were collected,including basic information and initial serum biomarker test results.Patients were randomly divided into training and test sets at a 7:3 ratio.An external validation set consisting of 313 AAD patients admitted to the Second Hospital of Hebei Medical University from January 2020 to December 2023 was also established for further model validation.Variables were screened using LASSO regression,and an XGBoost machine learning model was constructed and interpreted using SHAP.The predictive performance of the model was evaluated using receiver operating characteristic(ROC)curve analysis.Using the Shiny package,the XGBoost model was deployed to shinyapps.io to create a prediction website for postoperative mortality risk in AAD patients.One patient was selected by simple random sampling from the test set and the external validation set respectively for the prediction example on the Shiny webpage.Results The XGBoost model demonstrated high predictive performance for postoperative mortality in AAD patients,with area under the ROC curve(AUC)values of 0.928(95%CI 0.901-0.956)in the training set,0.919(95%CI 0.891-0.949)in the test set,and 0.941(95%CI 0.915-0.967)in the external validation set.SHAP values indicated the following order of variable importance in the model(from highest to lowest):"lactate dehydrogenase""blood chlorine""multiple organ injury""carbon dioxide combining power""prothrombin time""α-hydroxybutyric acid""creatine kinase isoenzyme""Stanford classification""combined use of bedside blood purification""gender""acute kidney injury""gastrointestinal bleeding""brain injury"and"shock".A risk prediction website for adverse postoperative outcomes in AAD patients was developed using XGBoost-SHAP method(https://dun-dunxiaolu.shinyapps.io/document/)and validated with examples.One randomly selected patient from each of the test and external validation sets was applied:the predicted mortality risk value for patient 1(who died postoperatively)was 0.9539,and that for patient 2(who survived postoperatively)was 0.0206.Conclusions The XGBoost-SHAP model demonstrates high accuracy in predicting postoperative mortality risk for AAD patients.The online prediction tool established based on this model enhances the identification efficiency of high-risk postoperative mortality patients.