Objective To analyze the technical movement characteristics of female table tennis play-ers with shoulder impingement syndrome when hitting a forehand topspin loop ball,in order to explore the reasons for shoulder impingement syndrome.Methods Thirteen female table tennis athletes with shoulder impingement syndrome were recruited for the shoulder impingement group(age 20.31±2.56 years,height 165.69±4.00 cm,weight 56.62±6.00 kg)and 13 healthy female table tennis athletes(age 21.54±2.78 years,height 165.54±4.45 cm,weight 60.08±8.02 kg)were selected for the healthy group.Kinematic and electromyographic data of the upper limbs were collected during six tri-als of forehand topspin strokes using a three-dimensional motion capture system and a wireless surface electromyographic system.The data were then averaged and compared between the groups.Results The shoulder impingement group had a greater shoulder flexion angular velocity at the end of the forward swing compared to the healthy group(t=-3.689,P=0.001).In addition,the shoulder impingement group showed significantly smaller trunk torsion angular amplitude(t=2.614,P=0.015)and average an-gular velocity of trunk torsion(t=3.958,P=0.001).Furthermore,the peak activation level of the anteri-or serratus muscle was smaller in the shoulder impingement group compared to the healthy group(t=2.363,P=0.027).Finally,the deactivation duration of both the triceps brachii and brachioradialis mus-cles was shorter in the shoulder impingement group compared to the latter(t=3.705,P=0.002;t=3.29,P=0.004).Conclusion Female table tennis players with shoulder impingement syndrome exhibit the fol-lowing characteristics in their forehand topspin:1)insufficient trunk rotation and premature deactiva-tion of the brachioradialis muscle,which lead to excessive loading on the shoulder during flexion;2)inadequate activation of the serratus anterior muscle,resulting in compromised scapular stability;3)premature deactivation of the triceps brachii muscle,which negatively affects the control of eccentric contraction velocity at the shoulder joint.

BACKGROUND:The sports medicine community has widely called for the use of machine learning technology to efficiently process the huge and complicated sports data resources,and construct intelligent sports injury prediction models,enabling accurate early warning of sports injuries.It is of great significance to comprehensively summarize and review such research results so as to grasp the direction of early warning model improvement and to guide the construction of sports injury prediction models in China. OBJECTIVE:To systematically review and analyze relevant research on sports injury prediction models based on machine learning technology,thereby providing references for the development of sports injury prediction models in China. METHODS:Literature search was conducted on CNKI,Web of Science and EBSCO databases,which mainly searched for literature related to machine learning techniques and sports injuries.Finally,61 articles related to sports injury prediction models were included for analysis. RESULTS AND CONCLUSION:(1)In terms of external risk feature indicators,there is a lack of competition scenario indicators,and the inclusion of related feature indicators needs to be further improved to further enrich the dimensions of the dataset for model training.In addition,the inclusion feature weighting methods of the sports injury prediction model are mainly based on filtering methods and the use of embedding and wrapping weighting methods needs to be strengthened in order to enhance the analysis of the interaction effects of multiple risk factors.(2)In terms of model body training,supervised learning algorithms become the mainstream choice.Such algorithms have higher requirements for the completeness of sample labeling information,and the application scenarios are easily limited.Therefore,the application of unsupervised and semi-supervised algorithms can be increased in the later stage.(3)In terms of model performance evaluation and optimization,the current studies mainly adopt two verification methods:HoldOut crossover and k-crossover.The range of AUC values is(0.76±0.12),the range of sensitivity is(75.92±11.03)%,the range of specificity is(0.03±4.54)%,the range of F1 score is(80.60±10.63)%,the range of accuracy is(69.96±13.10)%,and the range of precision is(70±14.71)%.Data augmentation and feature optimization are the most common model optimization operations.The accuracy and precision of the current sports injury prediction model are about 70%,and the early warning effect is good.However,the model optimization operation is relatively single,and data augmentation methods are often used to improve model performance.Further adjustments to the model algorithm and hyperparameters are needed to further improve model performance.(4)In terms of model feature extraction,most of the internal risk profile indicators included are mainly based on anthropometrics,training load,years of training,and injury history,but there is a lack of sports recovery and physical function indicators.

Objective: To analyze the changing trend and distribution characteristics of hepatitis C virus (HCV) infection among blood donors in Hebei, thereby providing data to support strategy and procedure adjustment for blood collection and supply institutions. Methods: Data from 12 blood stations in Hebei Province from 2012 to 2021 were collected. These data were analyzed to determine trends in anti-HCV antibody double reagent reactive rate and to characterize its distribution among different donor categories, genders and birth cohorts. Results: During the period from 2012 to 2021, a total of 7.4576 million samples were tested at 12 blood stations in Hebei Province, with 3.4659 million (46.47%) from first-time donors, and 3.9917 million (53.53%) from repeat donors. The number (of anti-HCV double reagent reactive samples was 7167 (9.61/10 000). The anti-HCV double reagent reactive rate showed a annual downward trend (P<0.05), from 17.40/10 000 at the beginning to 4.95/10 000 at the end of the study period. Additionally, the double reagent reactive rate of repeat blood donors had remained below 1/10 000 since 2017. The double reagent reactive rate of first-time blood donors (19.42/10 000) was higher than in repeat donors (1.09/10 000) (P<0.05), and the double-reagent reactive rate of female first-time blood donors (20.98/10 000) was higher than that of male first-time blood donors (18.49/10 000) (P<0.05). The anti-HCV double reagent reactive rate among first-time donors exhibited two distinct peaks within the pre-1976 and 1989-1994 birth cohorts, with notable gender differences observed in both peak periods. The rate of double reagent reactive in females born before 1976 (52.22/10 000) was higher than that in males (32.28/10 000) (P<0.05), while that of males born in 1989-1994 was higher (25.75/10 000) than that of females (14.28/10 000) (P<0.05). Conclusion: The prevalenc of HCV infection among blood donors in Hebei Province has shown a consistent year-over-year decline over the study period. The majority of infected individuals are found among the first-time blood donors born before 1995. These trends and characteristics provide valuable insights for developing pre-blood collection screening strategies, analyzing nucleic acid test data in blood screening, adjusting blood screening procedures, and provide evidence for targeted screening of high-risk populations as part of public health initiatives to eliminate hepatitis C.

Objective:To investigate the adjunctive diagnostic value of retinal imaging structural parameters combined with apolipoprotein E (ApoE) gene polymorphisms for Alzheimer′s disease (AD).Methods:It was a case-control study, 71 confirmed AD patients who attended the Department of Neurology in Sichuan Provincial People′s Hospital from May 2023 to June 2024 and 156 healthy medical checkups who participated in medical checkups in the Health Management Center were continuously with convenience sampling method; the subjects were included as the AD case group and healthy control group, respectively. Optical coherence tomography (OCT) was used to measure the structural parameters of retinal imaging such as the thickness of the retinal nerve fiber layer (RNFL) and the retinal nerve fiber layer-inner plexiform layer (RNFL-IPL) in the study subjects. Information on demographic characteristics and disease history of the study participants were collected through a questionnaire, and venous blood was collected to test for ApoE gene polymorphisms. The retinal imaging structural parameters, ApoE gene polymorphisms and other related indicators were included in a multifactorial logistic regression model to analyze the main factors affecting the risk of AD. Based on the results of the multifactorial analysis, the receiver operating characteristic (ROC) curves were plotted and the areas under the curve (AUC) were calculated to evaluate the efficacy of different models in the adjunctive diagnosis of AD.Results:Of the 227 study subjects included in the analysis, 153 were females and 74 were males; there were 71 cases in the AD case group with a mean age of (66.73±8.83) years, and there were 156 subjects in the healthy control group with an average age of (61.95±8.21) years. Educational attainment of elementary school and below ( OR=4.683, 95% CI: 2.133-10.282), living visual acuity<0.5 ( OR=2.716, 95% CI: 1.12-6.583), and carrying ≥1 ApoE ε4 genes ( OR=5.331, 95% CI: 2.309-11.891) were positively correlated with the risk of AD. RNFL thickening ( OR=0.923, 95% CI: 0.854-0.998) was negatively associated with the risk of AD (all P<0.05). The AD risk assessment model (Model 4), which included fundus imaging features and ApoE gene polymorphisms, had the highest predictive efficacy (AUC=0.857, P<0.001). Conclusion:Retinal imaging structural parameters differ significantly between AD patients and healthy examinees, and a risk assessment model combining retinal imaging structural parameters and ApoE gene polymorphisms has high predictive value and is expected to serve as an auxiliary diagnostic tool for AD.

AIM:To investigate the protective ef-fect of plumbagin(PL)against pulmonary fibrosis(PF)and its possible mechanisms.METHODS:Sixty male C57BL/6 mice were randomly divided into control,bleomycin group(BLM),low dose PL group(1 mg/kg)and high dose PL group(2 mg/kg).The mice PF model was replicated using intratracheal injection of BLM(3 mg/kg),and then PL(1 or 2 mg/kg)was injected intraperitoneally for 3 weeks and the animals were executed.HE and Masson staining were used to observe morphological changes in lung tissue and collagen deposition.The activities or levels of superoxide dismutase(SOD),glutathione(GSH),malondialdehyde(MDA)and hy-droxyproline(HYP)were measured in mouse lung tissue;ELISA for interleukin-6(IL-6)in mouse lung tissue.Immunohistochemical detection of nuclear factor-related factor 2(Nrf2)and reduced nicotin-amide adenine dinucleotide phosphate oxidase 4(NOX4)positive cell expression in mouse lung tis-sue.The expression levels of α-smooth muscle ac-tin(α-SMA),collagen Ⅰ(Col Ⅰ),collagen Ⅲ(Col Ⅲ),IL-6,transforming growth factor-β1(TGF-β1),p-Smad2,Nrf2 and NOX4 were detected by Western blotting.RESULTS:Compared with the BLM group,PL treatment attenuated lung parenchymal and in-terstitial injury and extracellular matrix deposition in mice,reduced HYP content(P＜0.01,P＜0.05),de-creased protein expression of α-SMA,collagen Ⅰand Ⅲ(P＜0.01,P＜0.05),diminished IL-6 secretion(P＜0.01);improved the body's antioxidant capacity(increased SOD and GSH activity and decreased MDA content,P＜0.01,P＜0.05),significantly down-regulated TGF-β1,p-Smad2 and NOX4-positive cells and protein expression(P＜0.01,P＜0.05)and up-regulated Nrf2-positive cells and protein expression(P＜0.01,P＜0.05).CONCLUSION:PL may slow down the PF process by modulating the TGF-β1/Smad2 and Nrf2/NOX4 pathways to attenuate inflammato-ry responses and collagen deposition and improve the body's antioxidant capacity.

Objective To analyze the technical movement characteristics of female table tennis play-ers with shoulder impingement syndrome when hitting a forehand topspin loop ball,in order to explore the reasons for shoulder impingement syndrome.Methods Thirteen female table tennis athletes with shoulder impingement syndrome were recruited for the shoulder impingement group(age 20.31±2.56 years,height 165.69±4.00 cm,weight 56.62±6.00 kg)and 13 healthy female table tennis athletes(age 21.54±2.78 years,height 165.54±4.45 cm,weight 60.08±8.02 kg)were selected for the healthy group.Kinematic and electromyographic data of the upper limbs were collected during six tri-als of forehand topspin strokes using a three-dimensional motion capture system and a wireless surface electromyographic system.The data were then averaged and compared between the groups.Results The shoulder impingement group had a greater shoulder flexion angular velocity at the end of the forward swing compared to the healthy group(t=-3.689,P=0.001).In addition,the shoulder impingement group showed significantly smaller trunk torsion angular amplitude(t=2.614,P=0.015)and average an-gular velocity of trunk torsion(t=3.958,P=0.001).Furthermore,the peak activation level of the anteri-or serratus muscle was smaller in the shoulder impingement group compared to the healthy group(t=2.363,P=0.027).Finally,the deactivation duration of both the triceps brachii and brachioradialis mus-cles was shorter in the shoulder impingement group compared to the latter(t=3.705,P=0.002;t=3.29,P=0.004).Conclusion Female table tennis players with shoulder impingement syndrome exhibit the fol-lowing characteristics in their forehand topspin:1)insufficient trunk rotation and premature deactiva-tion of the brachioradialis muscle,which lead to excessive loading on the shoulder during flexion;2)inadequate activation of the serratus anterior muscle,resulting in compromised scapular stability;3)premature deactivation of the triceps brachii muscle,which negatively affects the control of eccentric contraction velocity at the shoulder joint.

AIM:To investigate the protective ef-fect of plumbagin(PL)against pulmonary fibrosis(PF)and its possible mechanisms.METHODS:Sixty male C57BL/6 mice were randomly divided into control,bleomycin group(BLM),low dose PL group(1 mg/kg)and high dose PL group(2 mg/kg).The mice PF model was replicated using intratracheal injection of BLM(3 mg/kg),and then PL(1 or 2 mg/kg)was injected intraperitoneally for 3 weeks and the animals were executed.HE and Masson staining were used to observe morphological changes in lung tissue and collagen deposition.The activities or levels of superoxide dismutase(SOD),glutathione(GSH),malondialdehyde(MDA)and hy-droxyproline(HYP)were measured in mouse lung tissue;ELISA for interleukin-6(IL-6)in mouse lung tissue.Immunohistochemical detection of nuclear factor-related factor 2(Nrf2)and reduced nicotin-amide adenine dinucleotide phosphate oxidase 4(NOX4)positive cell expression in mouse lung tis-sue.The expression levels of α-smooth muscle ac-tin(α-SMA),collagen Ⅰ(Col Ⅰ),collagen Ⅲ(Col Ⅲ),IL-6,transforming growth factor-β1(TGF-β1),p-Smad2,Nrf2 and NOX4 were detected by Western blotting.RESULTS:Compared with the BLM group,PL treatment attenuated lung parenchymal and in-terstitial injury and extracellular matrix deposition in mice,reduced HYP content(P＜0.01,P＜0.05),de-creased protein expression of α-SMA,collagen Ⅰand Ⅲ(P＜0.01,P＜0.05),diminished IL-6 secretion(P＜0.01);improved the body's antioxidant capacity(increased SOD and GSH activity and decreased MDA content,P＜0.01,P＜0.05),significantly down-regulated TGF-β1,p-Smad2 and NOX4-positive cells and protein expression(P＜0.01,P＜0.05)and up-regulated Nrf2-positive cells and protein expression(P＜0.01,P＜0.05).CONCLUSION:PL may slow down the PF process by modulating the TGF-β1/Smad2 and Nrf2/NOX4 pathways to attenuate inflammato-ry responses and collagen deposition and improve the body's antioxidant capacity.

Objective:To investigate the adjunctive diagnostic value of retinal imaging structural parameters combined with apolipoprotein E (ApoE) gene polymorphisms for Alzheimer′s disease (AD).Methods:It was a case-control study, 71 confirmed AD patients who attended the Department of Neurology in Sichuan Provincial People′s Hospital from May 2023 to June 2024 and 156 healthy medical checkups who participated in medical checkups in the Health Management Center were continuously with convenience sampling method; the subjects were included as the AD case group and healthy control group, respectively. Optical coherence tomography (OCT) was used to measure the structural parameters of retinal imaging such as the thickness of the retinal nerve fiber layer (RNFL) and the retinal nerve fiber layer-inner plexiform layer (RNFL-IPL) in the study subjects. Information on demographic characteristics and disease history of the study participants were collected through a questionnaire, and venous blood was collected to test for ApoE gene polymorphisms. The retinal imaging structural parameters, ApoE gene polymorphisms and other related indicators were included in a multifactorial logistic regression model to analyze the main factors affecting the risk of AD. Based on the results of the multifactorial analysis, the receiver operating characteristic (ROC) curves were plotted and the areas under the curve (AUC) were calculated to evaluate the efficacy of different models in the adjunctive diagnosis of AD.Results:Of the 227 study subjects included in the analysis, 153 were females and 74 were males; there were 71 cases in the AD case group with a mean age of (66.73±8.83) years, and there were 156 subjects in the healthy control group with an average age of (61.95±8.21) years. Educational attainment of elementary school and below ( OR=4.683, 95% CI: 2.133-10.282), living visual acuity<0.5 ( OR=2.716, 95% CI: 1.12-6.583), and carrying ≥1 ApoE ε4 genes ( OR=5.331, 95% CI: 2.309-11.891) were positively correlated with the risk of AD. RNFL thickening ( OR=0.923, 95% CI: 0.854-0.998) was negatively associated with the risk of AD (all P<0.05). The AD risk assessment model (Model 4), which included fundus imaging features and ApoE gene polymorphisms, had the highest predictive efficacy (AUC=0.857, P<0.001). Conclusion:Retinal imaging structural parameters differ significantly between AD patients and healthy examinees, and a risk assessment model combining retinal imaging structural parameters and ApoE gene polymorphisms has high predictive value and is expected to serve as an auxiliary diagnostic tool for AD.

Objective To analyze the risk of return to sport in athletes using their gait data following anterior cruciate ligament re-construction(ACLR). Methods From May to June,2023,39 athletes after ACLR were recruited in Wuhan Sports University.Their data on sta-ble gait and tandem gait were recorded using a three-dimensional motion capture system,surface electromyogra-phy and a three-dimensional ergometer table.Additionally,return-to-sport scores were calculated using the K-STARTS test.The relationship between each gait indicator and the total score of the K-STARTS test was ana-lyzed with Pearson correlation analysis.Furthermore,the key indicators related to the risk of return to sport were analyzed using linear regression. Results In the stable gait test,the step time was negatively correlated with the total score of K-STARTS(r=-0.479,P=0.002),and the peak amplitude symmetry index of rectus femoris(r=0.448,P=0.004)and vastus lateralis(r=0.595,P=0.001)were positively correlated with the total score of K-STARTS.In the tandem gait test,the lateral displacement distance of the center of gravity was negatively correlated with the total score of K-STARTS(r=-0.341,P=0.034),and the time symmetry index of peak amplitude of vastus lateralis was positively correlated with the total score of K-STARTS(r=0.320,P=0.047).Regression analysis showed that the interpretation of the model based on stable gait(F=15.818,P=0.001,R2=0.650)was better than that based on tandem gait(F=7.692,P=0.001,R2=0.397). Conclusion In stable gait,gait rhythm variability and symmetry are correlated with return to sport risk.In tandem gait,gait balance and symmetry indexes are correlated with return-to-sport risk.Compared with tandem gait,the inter-pretation of return-to-sport risk assessment model based on stable gait information is better,and may be more suitable as a simple return-to-sport risk test method.

ObjectiveTo investigate the difference in bilateral lower limb muscle synergy mode during gait in patients after unilateral anterior cruciate ligament reconstruction. MethodsElectromyography from bilateral lower limb muscles during gait were collected from twelve male and eight female patients after unilateral anterior cruciate ligament reconstruction in Affiliated Hospital of Wuhan Sports University, from April to June, 2023. The data were analyzed using non-negative matrix decomposition algorithm to extract the number of muscle synergies in the affected and unaffected legs, the time to peak activation of muscle synergies and the relative weights of the muscles. ResultsSix types of muscle synergy were identified in the unaffected leg of males during gait, while five types were identified in the affected leg, lacking synergy 2 that mainly from the tibialis anterior muscle. Six types of muscle synergy were identified in both legs in females during gait. There was no significant difference in the time to peak activation of muscle synergies between both legs in males (P > 0.05). However, the time to peak activation of muscle synergies increased in females in the affected leg for synergy 3 and synergy 5 (P < 0.05). The relative weight of the rectus femoris was lower in synergy 1 in the affected leg in males (P < 0.05). For female, the relative weight of the vastus lateralis was higher and the relative weight of the biceps femoris was lower in synergy 2 in the affected leg in females (P < 0.05); while the relative weight of the rectus femoris was lower in synergy 3 (P < 0.05), and the relative weight of the biceps femoris was lower in synergy 6 (P < 0.05). ConclusionMales would freeze the muscle synergy dominating ankle dorsiflexion in affected leg to enhance ankle stability, and reduce the relative weight of rectus femoris during the loading response phase to weaken the knee landing cushioning. However, females would delay the activation of synergies dominating in loading response phase and the mid-stance phase, enhance the relative weight of vastus lateralis during the loading response phase, and reduce the relative weights of rectus femoris in the loading response phase and the relative weight of biceps femoris in the mid-stance phase, to limit knee flexion.