Objective The biological characteristics and action mechanisms underlying the excellent performance of skeletal muscles were studied through experiments to provide a scientific basis for the development of flexible actuators with performance comparable to that of skeletal muscles.Methods A frog skeletal muscle sample was contracted by applying electrical stimulation,and then tensile load was applied to it to analyze the relationship between the driving properties(such as contraction length and output force)of skeletal muscle and its structure from three aspects:skeletal muscle dimensions,tendon,and epimysium.Results The contraction lengths of these skeletal muscle samples were approximately 28.92％and 20％under unloaded conditions and under 50％of their maximum output force,respectively.When the load on the skeletal muscles did not exceed 20％of their maximum output force,they also exhibited the property of rapid reduction(approximately 1.25 s).The active tendon increased contraction by approximately 19.68％compared with the inactive tendon,and the integrity of the epimysium protected the force transfer efficiency of skeletal muscles.Conclusions By simulating the structural and biomechanical properties of skeletal muscles,flexible actuators can achieve better driving performance,thus greatly promoting the development of bionic robots.

Objective The biological characteristics and action mechanisms underlying the excellent performance of skeletal muscles were studied through experiments to provide a scientific basis for the development of flexible actuators with performance comparable to that of skeletal muscles.Methods A frog skeletal muscle sample was contracted by applying electrical stimulation,and then tensile load was applied to it to analyze the relationship between the driving properties(such as contraction length and output force)of skeletal muscle and its structure from three aspects:skeletal muscle dimensions,tendon,and epimysium.Results The contraction lengths of these skeletal muscle samples were approximately 28.92％and 20％under unloaded conditions and under 50％of their maximum output force,respectively.When the load on the skeletal muscles did not exceed 20％of their maximum output force,they also exhibited the property of rapid reduction(approximately 1.25 s).The active tendon increased contraction by approximately 19.68％compared with the inactive tendon,and the integrity of the epimysium protected the force transfer efficiency of skeletal muscles.Conclusions By simulating the structural and biomechanical properties of skeletal muscles,flexible actuators can achieve better driving performance,thus greatly promoting the development of bionic robots.

Objective To investigate the impact of cardiomyocyte ferroptosis on acute myocardial infarction(AMI)and its relationship with the expression of long non-coding RNA(lncRNA)GAS5.Methods An AMI model was established in eighteen male SD rats(6-8 weeks old),and then the subjected rats were randomly divided into blank control group,sham operation group,and model group,6 animals in each group.In 2 weeks after surgery,echocardiography was used to evaluate heart function,and TTC staining,HE staining and TUNEL staining were employed re-spectively to observe myocardial infarct area,histopathological changes of myocardial tissues and apoptosis in cardiomyocytes.Serum Fe2+concentration was measured with an iron ion detection kit.The expression levels of lncRNA GAS5,nuclear factor erythroid-derived 2-like 2(Nrf2),and glutathione peroxidase 4(GPX4)in myocardial tissues were detected with QT-PCR.Linear corre-lation analysis was performed to investigate the relationship between the expression of lncRNA GAS5,Nrf2 and GPX4 with Fe2+concentration.Western blotting was conducted for the protein levels of ferroptosis-related proteins,glutathione peroxidase 4(GPX4),nuclear factor erythroid-derived 2-like 2(Nrf2),glucose-regulated protein 78(GRP78),and cysteinyl aspartate specific proteinase 12(Caspase-12)in myocardial tissues.Results Western blotting revealed obvious in-creases in the protein levels of ferroptosis related proteins GRP78(1.11±0.13 vs 0.51±0.08,P＜0.01)and Caspase-12(1.23±0.05 vs 0.92±0.07,P＜0.05)and a decrease in those of ferroptosis inhibitor GPX4(0.27±0.11 vs 0.68±0.10,P＜0.01)and Nrf2(0.30±0.12 vs 0.58±0.04,P＜0.05)in the model group than the sham operation group.Additionally,QT-PCR showed that the mRNA levels of GPX4 and Nrf2 were notably lower,indicating cardiomyocyte ferroptosis,while that of lncRNA GAS5 was remarkably higher in the myocardial tissues of the model group than the sham operation group(P＜0.01).What's more,the expression of lncRNA GAS5 had a positive correlation with serum Fe2+concentration(P＜0.05).Conclusion AMI is closely associated with cardiomyocyte ferroptosis.lncRNA GAS5 is involved in the regulation of ferroptosis by Nrf2/GPX4 signaling pathway,which thus mediating the occurrence of heart failure after AMI.

Objective:To investigate the clinical characteristics and potential predisposing factors of the external cervical resorption(ECR).Methods:22 ECR cases with 38 affected teeth from 2016 to 2022 were retrospectively reviwed.Descriptive analysis combined with single factor analysis was used to study the clinical characteristics and influencing factors of ECR.Results:Maxillary anterior teeth(34.2％)were the most affected by ECR.Univariate analysis showed that ECR was more commonly noted in teeth without percussion pain and palpation pain,the probing depth of the periodontal pocket was greater than 3mm,with pulp activity reaction,without forma-tion of abscess and/or sinus tract,and without periapical lesions.There were statistically significant differences in percussion tender-ness,palpation tenderness and probing depth among the different Heithersary stages(P＜0.05).In the advanced cases,deep periodon-tal pockets and abscess formation were observed.The most common related dental factors of ECR were orthodontic treatment(15.87％)and dental traumatic injury(28.57％).Conclusion:ECR affected teeth often lack of clinical signs and symptoms.Radiology is the key to early diagnosis.

Based on the management by objectives and developmental performance appraisal,Shanghai Tenth People's Hospital explored the performance appraisal scheme for attending,including disease-specific complexity,disease-specific difficulty,clinical risk-taking and comprehensive quality.Assessment and feedback work was imple-mented by the medical management department,which format a set of independent budget of the physician perfor-mance assessment system.It introduced incentive measures to encourage attending to treat difficult and critical cases,provided high quality medical services,and eventually enhance hospital management effectiveness to attending.

Based on the management by objectives and developmental performance appraisal,Shanghai Tenth People's Hospital explored the performance appraisal scheme for attending,including disease-specific complexity,disease-specific difficulty,clinical risk-taking and comprehensive quality.Assessment and feedback work was imple-mented by the medical management department,which format a set of independent budget of the physician perfor-mance assessment system.It introduced incentive measures to encourage attending to treat difficult and critical cases,provided high quality medical services,and eventually enhance hospital management effectiveness to attending.

Based on the management by objectives and developmental performance appraisal,Shanghai Tenth People's Hospital explored the performance appraisal scheme for attending,including disease-specific complexity,disease-specific difficulty,clinical risk-taking and comprehensive quality.Assessment and feedback work was imple-mented by the medical management department,which format a set of independent budget of the physician perfor-mance assessment system.It introduced incentive measures to encourage attending to treat difficult and critical cases,provided high quality medical services,and eventually enhance hospital management effectiveness to attending.

Based on the management by objectives and developmental performance appraisal,Shanghai Tenth People's Hospital explored the performance appraisal scheme for attending,including disease-specific complexity,disease-specific difficulty,clinical risk-taking and comprehensive quality.Assessment and feedback work was imple-mented by the medical management department,which format a set of independent budget of the physician perfor-mance assessment system.It introduced incentive measures to encourage attending to treat difficult and critical cases,provided high quality medical services,and eventually enhance hospital management effectiveness to attending.

Based on the management by objectives and developmental performance appraisal,Shanghai Tenth People's Hospital explored the performance appraisal scheme for attending,including disease-specific complexity,disease-specific difficulty,clinical risk-taking and comprehensive quality.Assessment and feedback work was imple-mented by the medical management department,which format a set of independent budget of the physician perfor-mance assessment system.It introduced incentive measures to encourage attending to treat difficult and critical cases,provided high quality medical services,and eventually enhance hospital management effectiveness to attending.

Based on the management by objectives and developmental performance appraisal,Shanghai Tenth People's Hospital explored the performance appraisal scheme for attending,including disease-specific complexity,disease-specific difficulty,clinical risk-taking and comprehensive quality.Assessment and feedback work was imple-mented by the medical management department,which format a set of independent budget of the physician perfor-mance assessment system.It introduced incentive measures to encourage attending to treat difficult and critical cases,provided high quality medical services,and eventually enhance hospital management effectiveness to attending.