BACKGROUND:It has been found that internal factors such as anatomical structure,hormone level and neuromuscular function of athletes are closely related to the risk of anterior cruciate ligament injuries,and external factors such as the material of the playing field also become one of the risk factors affecting the occurrence of non-contact anterior cruciate ligament injuries,but they are relatively under-attended in the current studies. OBJECTIVE:To explore effects of artificial turf versus natural grass on the biomechanical performance of the lower limbs in young females during jump-landing. METHODS:According to the test needs,artificial turf and natural grass in accordance with the standards of GB/T 20033.3-2006 and GB/T 19995.1-2005 were leveled and fixed on two three-dimensional force measuring platforms.Twenty-one young females were voluntarily recruited and completed the jump-landing task on the artificial turf and natural grass.Subjects stood on the steps and then jumped forward,jumped down to the force measuring platform and immediately jumped with full force to the force measuring platform again.The two landings were required to fall to the two force measuring platforms,and the whole jumping action was considered successful without any pause.The kinematic,kinetic and electromyographic data of the lower limbs during the landing process were collected synchronously to compare and analyze the differences between the two. RESULTS AND CONCLUSION:In terms of kinetics,posterior and vertical ground reaction force at the initial landing moment during jump-landing on the natural grass were significantly lower than those on the artificial turf(P＜0.05,P＜0.01),as well as at the peak ground reaction force moment(P＜0.05,P＜0.05).Additionally,the knee flexion moment when jump-landing on the natural grass was higher than that on the artificial turf(P＜0.01).In terms of electromyography,within 100 ms after the initial landing moment,the electromyography activity levels of medial femoris muscle,lateral femoris muscle and anterior tibialis muscle when jump-landing on the natural grass were significantly lower than those on the artificial turf(P＜0.05,P＜0.01,P＜0.05).To conclude,compared with the natural grass,jump-landing on the artificial turf leads to an change in biomechanical performance that will cause an increase in anterior cruciate ligament tension.

Objective To observe the reproducibility of radiomics feature(RF)extracted from virtual monoenergetic image(VMI)of rabbit VX2 hepatoma models obtained with 3 different dual-energy CT(DECT)systems,and to explore relationship of reproducibility and diagnostic performance of RF.Methods Fifteen rabbits with VX2 hepatoma were randomly divided into 3 groups(each n=5).Contrast-enhanced abdominal CT scanning under volume CT dose index(CTDIvol)levels of 6,9 and 12 mGy were performed with dual-source DECT(dsDECT),rapid kV switching DECT(rsDECT)and dual-layer detector DECT(dlDECT),respectively.VMI were reconstructed at 10 keV increments from 40 to 140 keV.RF were extracted from VMI,the reproducibility was assessed using intra-class correlation coefficient(ICC),and those with ICC≥0.8 were considered as reproducible RF.The percentage of reproducible features(denoted by R)were compared among different scanner pairings and different CTDIvol levels.Within each CTDIvol group,the reconstruction energy levels yielding the maximum number(denoted by N)of common RF across different scanner pairings were identified.The receiver operating characteristic(ROC)curve was drawn,the area under the curve(AUC)was calculated,and the diagnostic efficacies of reproducible RF and other RF were compared under optimal reproducible conditions.Spearman correlation coefficient between ICC and the corresponding AUC of RF were calculated.Results RrsDECT-dsDECT(6.45％,95％CI[2.36％,8.87％])was higher than RdlDECT-dsDECT(0.72％,95％CI[0.15％,1.79％])and RrsDECT-dlDECT(1.43％,95％CI[0.60％,4.06％])(all adjusted P＜0.05),R9mGy(3.70％,95％CI[1.31％,5.73％])and R12mGy(2.63％,95％CI[0.60％,6.69％])were higher than R6mGy(1.31％,95％CI[0.12％,1.55％])(all adjusted P＜0.05).The optimal reproducible reconstruction energy levels of RF under CTDIvol of 6,9 and 12 mGy concentrated at 50-70 keV.AUC of reproducible RFs were higher than of other RF(all adjusted P＜0.05)and had certain correlation with the reproducibility(rs=0.102-0.516,P＜0.05).Conclusion The reproducibility of RF extracted from contrast-enhanced VMI CT images of rabbit VX2 hepatoma models associated with DECT scanner,CTDIvol level and reconstruction energy level.RF with higher reproducibility might have better diagnostic performance.

Objective This study was performed to establish and compare guinea pig models of tuberculosis using intranasal and aerosol infection routes at different doses.The overall goal was to provide a foundation for establishing a standardized guinea pig model of tuberculosis for the study of respiratory tract infection.Methods Twenty-four female guinea pigs were randomly divided into six groups of four guinea pigs each.They were then infected with two doses of Mycobacterium tuberculosis through either the aerosol route(groups A,B,and C)or intranasal route(groups D,E,and F).Aerosol infection groups consist of 3 groups:group A(Aerosol control group,uninfected control group),group B(Aerosol low-dose group,5×102 CFU),and group C(Aerosol high-dose group,5×103 CFU)Intranasal infection groups also consist of 3 groups:group D(Intranasal control group,uninfected control group),group E(Intranasal low-dose group,1×104 CFU),and group F(Intranasal high-dose group,5×104 CFU).The clinical manifestations of the guinea pigs were observed after infection.All guinea pigs were euthanized on day 14.Lung,spleen,and liver tissues were obtained for gross examination and histopathological analysis using hematoxylin-eosin staining to identify characteristic lesions associated with tuberculosis.Acid-fast staining was performed on in situ tissues and organs followed by bacterial culture to analyze the bacterial load.Results The guinea pigs in four infection groups(B,C,E,and F)exhibited macroscopic tuberculosis lesions in the lung,spleen,and liver.Histopathological examination revealed the presence of tuberculous granuloma lesions.Acid-fast staining and bacterial load analysis demonstrated that the bacteria were primarily localized in the lung tissue of aerosol-infected groups B and C,with a few also present in the spleen and liver,and the bacterial load was 104～105 CFU/mL.In intranasal infection groups E and F,bacteria were found in the lung,spleen,and liver with a similar bacterial load of 104～105 CFU/mL.There was no significant difference in lesion severity or bacterial load among groups B,C,E,and F;however,groups B,C,and F showed low standard deviations for both pathology and etiology.Conclusions A guinea pig model of acute tuberculosis was successfully established using two doses administered through distinct routes of infection.Pathological examination and pathogenic analysis demonstrated that an aerosol dose of 5×102 CFU of Mtb effectively established a homogeneous model of acute tuberculosis with good consistency among the animals.Additionally,intranasal infection with 5×104 CFU of Mtb produced a relatively uniform model of tuberculosis.Notably,however,aerosol infection at 5×102 CFU progressed to an acute tuberculosis model more rapidly than intranasal infection at 5×104 CFU.

Objective:To explore the impact of whole blood organophosphate esters (OPEs) flame retardant exposure on thyroid function-related hormones in healthy older adults.Methods:In this panel study, five repeated population-based epidemiological surveys and biological sample collection were conducted from September 2018 to January 2019, with 76 healthy older adults aged 60-69 years in the Dianliu Community of Jinan, Shandong Province. Information on the sociodemographic characteristics, diet, and health status of the respondents was systematically gathered through questionnaires and physical examinations. Fasting venous blood was collected to determine the levels of OPEs, thyroid-stimulating hormone (TSH), triiodothyronine (T 3), and thyroxine (T 4). A linear mixed-effects model was used to analyze the impact of OPEs exposure on thyroid function-related hormones in healthy older adults. Results:Each of the 76 subjects participated in at least two follow-up visits, resulting in a total of 350 person visits. The age of the study participants was (65.07±2.76) years, with 38 participants of both sexes. A total of eight OPEs were included with a detection rate exceeding 50%, and the M ( Q 1, Q3) for ∑OPEs was 3.85 (2.33, 5.74) ng/ml, with alkyl-OPEs being the major type of OPEs with an M ( Q 1, Q3) of 1.27 (0.64, 2.50) ng/ml. The M ( Q 1, Q3) for TSH, T 3, and T 4 was 3.74 (2.55, 5.69) μIU/ml, 1.32 (1.10, 1.60) ng/ml, and 45.04 (36.96, 53.27) ng/ml, respectively. Linear mixed-effects model showed that TSH was significantly decreased by 9.93% (95% CI:-15.17%, -4.36%) and 11.14% (95% CI:-15.94%, -6.06%) in older adults for each quartile level increase in TnBP and TEHP exposures, respectively. Gender-stratified analysis indicated that TEHP exposure was negatively associated with TSH levels in male older adults, whereas a decrease in TSH levels among female older adults was associated with TnBP exposure. Conclusion:Exposure to whole blood OPEs is associated with decreased TSH levels among healthy older adults, with notable gender differences.

Objective:To explore the impact of whole blood organophosphate esters (OPEs) flame retardant exposure on thyroid function-related hormones in healthy older adults.Methods:In this panel study, five repeated population-based epidemiological surveys and biological sample collection were conducted from September 2018 to January 2019, with 76 healthy older adults aged 60-69 years in the Dianliu Community of Jinan, Shandong Province. Information on the sociodemographic characteristics, diet, and health status of the respondents was systematically gathered through questionnaires and physical examinations. Fasting venous blood was collected to determine the levels of OPEs, thyroid-stimulating hormone (TSH), triiodothyronine (T 3), and thyroxine (T 4). A linear mixed-effects model was used to analyze the impact of OPEs exposure on thyroid function-related hormones in healthy older adults. Results:Each of the 76 subjects participated in at least two follow-up visits, resulting in a total of 350 person visits. The age of the study participants was (65.07±2.76) years, with 38 participants of both sexes. A total of eight OPEs were included with a detection rate exceeding 50%, and the M ( Q 1, Q3) for ∑OPEs was 3.85 (2.33, 5.74) ng/ml, with alkyl-OPEs being the major type of OPEs with an M ( Q 1, Q3) of 1.27 (0.64, 2.50) ng/ml. The M ( Q 1, Q3) for TSH, T 3, and T 4 was 3.74 (2.55, 5.69) μIU/ml, 1.32 (1.10, 1.60) ng/ml, and 45.04 (36.96, 53.27) ng/ml, respectively. Linear mixed-effects model showed that TSH was significantly decreased by 9.93% (95% CI:-15.17%, -4.36%) and 11.14% (95% CI:-15.94%, -6.06%) in older adults for each quartile level increase in TnBP and TEHP exposures, respectively. Gender-stratified analysis indicated that TEHP exposure was negatively associated with TSH levels in male older adults, whereas a decrease in TSH levels among female older adults was associated with TnBP exposure. Conclusion:Exposure to whole blood OPEs is associated with decreased TSH levels among healthy older adults, with notable gender differences.

Esophagogastric variceal bleeding (EGVB) is one of the main complications of decompensated portal hypertension, especially in patients with liver cirrhosis, and it often has a high mortality rate. Medication combined with endoscopy is the main prevention and treatment method for EGVB, while transjugular intrahepatic portosystemic shunt (TIPS) combined with variceal embolization can also be selected for some high-risk patients, and individualized diagnosis and treatment of portal hypertension based on hepatic venous pressure gradient should become the latest consensus and the main strategy. This article mainly reviews endoscopic therapy and TIPS for the prevention and treatment of EGVB patients with decompensated portal hypertension in terms of selection of indications, incidence rate of complications, and respective advantages and disadvantages.

Thymoma complicated with polymyositis and myasthenia gravis is a rare case, which can be clearly diagnosed and given symptomatic treatment according to its own diagnostic criteria, imaging and laboratory examinations. This paper reports the clinical data of a thymoma patient with polymyositis and myasthenia gravis admitted to the Seventh Affiliated Hospital of Sun Yat-Sen University, and discusses the possible pathogenesis and treatment methods.

【Objective】 To study the incidence and risk factors of bone loss in ulcerative colitis （UC） patients and understand the characteristics of fecal microbiota so as to provide new ideas for the mechanism and new treatment of bone loss in UC patients. 【Methods】 We chose adult UC patients from Department of Gastroenterology in The First Affiliated Hospital of Xi’an Jiaotong University as research subjects. We collected the patients’ related data and divided them into two groups. Then we analyzed the data to understand the incidence of and risk factors for bone loss in the UC patients. Furthermore， we collected the feces of the patients. Based on high-throughput sequencing technology， we analyzed the fecal microbiota’s diversity， species composition and metabolic pathways to understand the differences between the two groups. 【Results】 In the 24 UC patients， the incidence of bone loss was 62.5%. The incidence of bone loss was significantly higher in chronic relapsing UC patients than in initial patients， and the incidence of bone loss increased with the severity of UC. Serum calcium and 25-hydroxyvitamin D concentrations in the normal group were significantly higher than those in the bone loss group. β diversity significantly differed and the species composition of fecal microbiota significantly differed at the levels of phylum， class， order， family and genus between the two groups. Compared with the normal group， the expression abundance of Shigellosis， Geraniol degradation， Steroid hormone biosynthesis pathways was significantly increased in the bone loss group. 【Conclusion】 There is a high incidence of bone loss in UC patients. The clinical type， disease severity， serum calcium and 25-hydroxyvitamin D concentrations are related to bone loss in these patients. In the bone loss group， the diversity of fecal microbiota， especially the proportion of probiotics， is reduced， and the abundance of many disease-related metabolic pathways is significantly upregulated.

Objective:To explore the value of multiphasic CT-based radiomics signature in predicting the invasive behavior of pancreatic solid pseudopapillary neoplasm (pSPN).Methods:The multiphasic CT images of patients with pSPN confirmed by postoperative pathology in the First Affiliated Hospital of Zhengzhou University from January 2012 to January 2021 were analyzed retrospectively. There were 23 cases of invasiveness and 59 cases of non-invasiveness. The region of interest(ROI) was artificially delineated layer by layer in the plain scan, arterial-phase and venous-phase images, respectively. The 1 316 image features were extracted from each ROI. The data set was divided into training and validation sets with a ratio of 7∶3 by stratified random sampling, and synthetic minority oversampling technique (SMOTE) algorithm was used for oversampling in the training set to generate invasive and non-invasive balanced data for building the training model. The constructed model was validated in the validation set. The receiver operating characteristic(ROC) analysis was used to evaluate model performance and the Delong′s test was applied to compare the area under the ROC curve (AUC) of different predict models. The improvement for classification efficiency of each independent model or their combinations were also assessed by net reclassification improvement (NRI) and integrated discrimination improvement (IDI) indices.Results:After feature extraction, 2, 6 and 3 features were retained to construct plain-scanned model, arterial-phase and venous-phase models, respectively. Seven independent-phase and combined-phase models were established. Except the plain-scanned model, the AUC values of other models were greater than 0.800. The arterial-phase model had the best efficiency for classification among all independent-phase models. The AUC values of arterial-phase model in the SMOTE training and validation sets were 0.913 and 0.873, respectively. By combining the radiomics signature of the arterial-phase and venous-phase models, the AUC values of training and validation sets increased to 0.934 and 0.913 respectively. There were no significant differences of the AUC values between the scan-arterial venous-phase model and arterial venous-phase model in both training and validation sets (both P>0.05). The NRI and IDI indexes showed that the combined form of plain-scan model and arterial-venous-phase model could not significantly improve the classification efficiency in the validation set (both NRI and IDI<0). Conclusions:The arterial-phase CT-based radiomics model has a good predictive performance in the invasive behavior of pSPN, and the combination with a venous-phase radiomics model can further improve the model performance.

Objective:To investigate the impact of a reduced portacaval shunt on hepatic myelopathy (HM) in patients with cirrhosis after a transjugular intrahepatic portosystemic shunt (TIPS).Methods:Patients who developed HM after receiving TIPS at the First Affiliated Hospital of Xi'an Jiaotong University from January 2013 to June 2018 were retrospectively analyzed. HM severity was quantified by clinical spasticity index (CSI) and Fugl-Meyer Assessment (FMA) of the lower extremity. Clinical manifestations were combined with grades Ⅰ-Ⅳ. HM patients were divided into drug treatment (group A) and flow restriction group (group B) according to different treatment methods. The changes in CSI and FMA of the lower extremity after treatment were statistically analyzed in the two groups. P<0.05 was considered a statistically significant difference. Results:A total of 421 cases of cirrhosis who underwent TIPS were enrolled. Among them, 30 developed HM, with 22 in group A and 8 in group B. The incidence of HM after TIPS surgery was about 7.13%. After treatment, CSI was gradually increased and FMA of lower extremity was gradually decreased in group A, while vice-versa in group B. CSI in the two groups were differed significantly at 6, 12, 18, and 24 months after treatment ( P<0.05), while the difference in FMA of the lower extremity was statistically significant at 12, 18, and 24 months after treatment ( P<0.05). CSI was decreased and FMA of lower extremity was increased after treatment in patients with group A HM grade I. CSI, and FMA of lower extremity changes were statistically significant ( P<0.05) when compared with patients with HM grades Ⅱ-Ⅳ. The incidence of hepatic encephalopathy was significantly lower in group B than that in group A ( P=0.034), but there was no statistically significant difference between the two groups in the incidence of gastrointestinal bleeding, ascites, infection, MELD score and mortality. Conclusion:A reduced portacaval shunt can improve HM in patients with liver cirrhosis after TIPS, and drug therapy alone is effective for patients with early HM grade I.