Objective:To propose a functional method for locating the shoulder joint center of rotation aimed at rapid estimation of the upper limb reachable domain envelope, thereby informing ergonomic design and task optimization.Methods:In March 2024, shoulder kinematics during gait were recorded from ten adults using a three-dimensional motion-capture system. Assuming the existence of a point near the glenohumeral joint that maintains a fixed spatial relationship to the humerus and the acromion, we estimated both static and dynamic centers of rotation. Localization accuracy was quantified by the standard deviation of distance residuals to upper-arm markers. Upper-limb joint angles and anthropometric parameters were modeled via regression; combined with maximal joint ranges of motion, these were used to infer the reachable domain envelope.Results:The static center of rotation was located approximately twenty-two millimeters medial to the acromial landmark in the coronal plane and thirty-seven millimeters inferior to it. The standard deviation of the residuals for the distances from the dynamic shoulder joint center of rotation to upper-arm markers averaged 1.02 mm, which was 47.42% lower than that of the static center of rotation and 66.56% lower than that of the acromion. Moreover, the trajectory of this dynamic center showed a strong correlation with upper-limb joint angles ( R2>0.7) . Conclusion:The proposed method enables rapid and accurate estimation of the upper limb reachable domain envelope to support ergonomic design and may help reduce the risk of work-related musculoskeletal disorders.

Objective To develop a three-compartment kinetic fatigue model for the isometric muscle endurance of the hip,knee,and ankle joints at 50％IPT(isometric peak torque),so as to provide a theoretical basis for simulation-based assessments and load evaluations in biomechanics and sports science.Methods The IPT of the hip,knee,and ankle joints was measured in 40 male university students.Isometric endurance tests were then performed on all three joints at 50％IPT until exhaustion.Electromyography data and endurance time(ET)of major lower limb muscles were collected concurrently.The differences between ETs predicted by models based on previously recommended F and R parameters and actual ETs were analyzed.Subsequently,experimental ETs were used in a grid search to optimize Fand R parameters,allowing for the development of an accurate three-compartment kinetic model.Results The ET of the hip and ankle joints was significantly longer than that of the knee joint(P＜0.001).Models using previously recommended Fand R parameters overestimated ET,with significantly higher predicted values than experimentally measured ET(P＜0.001),as well as elevated root mean squared error(RMSE)and mean relatvie error(MRE)values.The grid search successfully identified Fand R parameters for the three-compartment model in isometric endurance tests of lower limb joints,with no statistical difference between model-predicted ET and experimental ET(P＞0.05).Conclusions The developed model in this study can serve as an indirect measurement tool for evaluating load in similar activities.

2-substituted quinolines are the building blocks for the synthesis of natural products and pharmaceuticals. In comparison with classical methods, dehydroaromatization of 2-substituted-1,2,3,4-tetrahydroquinolines has emerged in recent years as an efficient and straightforward method to synthesize quinolines due to its high atom economy and sustainability. However, existing chemical methods need transition metal catalysts and harsh reaction conditions. Biocatalysis with high efficiency, high selectivity, and mild reaction conditions has become an important method of organic synthesis. We mined a strain Pseudomonas monteilii ZMU-T06 capable of producing monoamine oxidase for the dehydroaromatization of 2-substituted-1,2,3,4-tetrahydroquinolines to synthesize 2-substituted quinolines (8 substrates, yields of 45.7%-48.4%) and then hypothesized the catalytic mechanism, providing a new method for green synthesis of 2-substituted quinolines.
Quinolines/chemistry* ; Pseudomonas/classification* ; Oxidation-Reduction ; Monoamine Oxidase/biosynthesis* ; Biocatalysis

Objective:To investigate the clinical characteristics of patients with hepatitis B virus（HBV）-related primary hepatocellular carcinoma（HCC）who were treated in a multidisciplinary team（MDT）for liver cancer，so as to provide a basis for clinical optimization of the diagnosis and treatment of patients with chronic hepatitis B（CHB）.Methods:A retrospective analysis was performed for 482 HBV-related HCC patients who were treated with HCC-MDT every Thursday afternoon in The First Affiliated Hospital of the Army Medical University from January 2022 to May 2024，aged 18-87（55.54±10.84）years，86.93%（419/482）males and 13.07%（63/482）females. According to the different underlying liver diseases at the time of initial medical treatment and the different prognostic outcomes at the later follow-up，the differences in clinical characteristics between groups under different conditions were compared and analyzed，and the influencing factors of HCC prognosis were understood by Logistic regression analysis. Results:At the time of MDT presentation，the differences in HBeAg status（ χ2=6.311 ，P=0.043），γ-glutamyl traspeptidase（GGT）（ Z=6.277， P=0.043），alkaline phosphatase（ALP）（ Z=7.236 ，P=0.027），and model for end-stage liver disease（MELD）scores（ Z=6.111， P=0.047）among patients with different underlying liver diseases were statistically significant. At follow-up，6.75%（11/163）of HBV-related HCC patients who presented to MDT had a family history of HCC，and their cumulative mortality rate was as high as 60.8%（205/337）at least for 1 year. Mulitivariate Logistic regression analysis showed that different underlying liver disease at the time of initial medical treatment，HBV DNA replication level，MELD score and choice of anti-cancer treatment regimen were the influencing factors for the prognosis of HCC（all P<0.05）. The worse the degree of cirrhosis at the initial presentation，the higher the level of HBV DNA replication，and the higher the MELD score，the worse the prognosis for HCC. Conclusion:Advancing the diagnosis and treatment of CHB，maximizing the inhibition of HBV DNA replication，reducing the MELD score，and optimizing the anti-cancer treatment regimen can reduce the mortality rate of HBV-related HCC.

Objective:To analyze the efficacy of combination of peginterferon α-2b（Peg-IFN α-2b）with nucleos（t）ide analogues（NAs）on antiviral therapy in children with chronic hepatitis B（CHB）and to provide an optimized clinical treatment strategies for CHB children.Methods:A retrospective analysis was conducted on 30 CHB children treated in The First Affiliated Hospital of the Army Medical University（Southwest Hospital）from January 2022 to January 2025 with treatment duration at least 48 weeks. The enrolled children were aged between 2 and 17 years and divided into the NAs combined with Peg-IFN α-2b（NPI）group（n=13）and NAs group（n=17）by their therapy regimens. The characteristics of baseline，week 12，week 24，week 48 and week 96 were compared between groups，as well as the differences in response to biochemical，immune and viral indicators at each observation point. Logistic regression analysis and receiver operating characteristic（ROC）curve analysis were performed to identify factors influencing the HBsAg seroclearance. Results:At baseline of treatment，the proportion of HBeAg positivity in the NPI group and the NAs group was high（76.9% vs 86.6%， χ2=0.679， P=0.628），and the alanine aminotransferase（ALT）and aspartate aminotransferase（AST）in the NPI group were significantly lower than those in the NAs group（ P<0.001）. At 24 weeks，the decrease in HBsAg in the NPI group was also significantly higher than that in the NAs group（ Z=-3.161， P=0.002）. Finally，the cumulative seroclearance rate of HBsAg at 96 weeks in the NPI group was significantly higher than that in the NAs group（46.15% vs 5.88%， χ2=0.679， P=0.025）. Mulitivariate Logistic regression analysis showed that treatment regimen and gender were risk factors affecting the outcome of HBsAg（ P<0.05）. ROC curve analysis showed that the increase in ALT at 12 weeks compared with baseline（AUC=0.857，Cutoff value=3.615 IU/L），the decrease in ALT at 24 weeks（AUC=0.870，Cutoff value=47.85 IU/L），and the decrease in HBsAg at 12 weeks and especially at 24 weeks（AUC=0.885，Cutoff value=0.97log IU/ml）were effective predictors of HBsAg prognosis at 96 weeks. Conclusion:In CHB children，antiviral regimen Peg-IFN α-2b combined with NAs was more effective than NAs alone in improving the HBsAg seroclearance rate of CHB，and the effects in female were better than in male. The decline of HBsAg and the fluctuation of ALT in the early treatment period are valid predictors of HBsAg clearance.

BACKGROUND:Surface electromyography has been extensively utilized for monitoring muscle fatigue. However,traditional electromyographic metrics typically focus on individual muscles and fail to assess the variations in a muscle group during the fatigue process. OBJECTIVE:To establish a muscle functional network to extract complex network parameters and investigate the topological property changes of the muscle functional network under different levels of fatigue,aiming to provide theoretical and methodological foundations for fatigue monitoring and prevention. METHODS:Eleven participants performed single-leg leg press exercise at 50％ of one-repetition maximum until exhaustion. Simultaneously,electromyographic signals of seven muscles (rectus femoris,vastus lateralis,vastus medialis,biceps femoris,tibialis anterior,lateral gastrocnemius,and medial gastrocnemius),electrocardiographic signals,and Borg CR-10 scale scores were collected. The Borg CR-10 scale was used to categorize three fatigue stages:mild,moderate,and severe. Heart rate and heart rate variability were calculated to validate the effective division of fatigue stages. Using the coherence of muscle signals,a muscle functional network was constructed with the seven muscles as nodes,and four complex network parameters (clustering coefficient,average weighted degree,global efficiency,and eigenvector centrality) were extracted. Additionally,four electromyographic indices (root mean square,median frequency,instantaneous mean frequency,and co-activation ratio) were extracted and compared under the three levels of fatigue. RESULTS AND CONCLUSION:(1) Differences in heart rate and heart rate variability were observed across three fatigue stages,indicating the effectiveness of fatigue stage delineation. (2) Electromyographic indicators for different muscles under three levels of fatigue:root mean square and co-activation ratio showed no differences;however,median frequency exhibited robust fatigue trends in vastus lateralis,vastus medialis,and biceps femoris,while instantaneous mean frequency demonstrated robust fatigue trends in rectus femoris,vastus lateralis,vastus medialis,and biceps femoris. Instantaneous mean frequency outperformed median frequency and root mean square,yet all three indicators showed robust trends only for the major working muscle groups,unaffected by fatigue factors,unlike the co-activation ratio. (3) The connectivity strength between vastus lateralis and vastus medialis,vastus lateralis and biceps femoris,vastus lateralis and gastrocnemius medialis,and vastus medialis and biceps femoris gradually increased,showing significant differences in average weighted degree,clustering coefficient,and global efficiency post-fatigue,significantly correlated with fatigue levels. To conclude,changes in connectivity strength reflect the synergy and complementarity among muscles during fatigue. Clustering coefficient,average weighted degree,and global efficiency serve as fatigue markers reflecting overall muscle changes.

Objective:To propose a functional method for locating the shoulder joint center of rotation aimed at rapid estimation of the upper limb reachable domain envelope, thereby informing ergonomic design and task optimization.Methods:In March 2024, shoulder kinematics during gait were recorded from ten adults using a three-dimensional motion-capture system. Assuming the existence of a point near the glenohumeral joint that maintains a fixed spatial relationship to the humerus and the acromion, we estimated both static and dynamic centers of rotation. Localization accuracy was quantified by the standard deviation of distance residuals to upper-arm markers. Upper-limb joint angles and anthropometric parameters were modeled via regression; combined with maximal joint ranges of motion, these were used to infer the reachable domain envelope.Results:The static center of rotation was located approximately twenty-two millimeters medial to the acromial landmark in the coronal plane and thirty-seven millimeters inferior to it. The standard deviation of the residuals for the distances from the dynamic shoulder joint center of rotation to upper-arm markers averaged 1.02 mm, which was 47.42% lower than that of the static center of rotation and 66.56% lower than that of the acromion. Moreover, the trajectory of this dynamic center showed a strong correlation with upper-limb joint angles ( R2>0.7) . Conclusion:The proposed method enables rapid and accurate estimation of the upper limb reachable domain envelope to support ergonomic design and may help reduce the risk of work-related musculoskeletal disorders.

Objective To develop a three-compartment kinetic fatigue model for the isometric muscle endurance of the hip,knee,and ankle joints at 50％IPT(isometric peak torque),so as to provide a theoretical basis for simulation-based assessments and load evaluations in biomechanics and sports science.Methods The IPT of the hip,knee,and ankle joints was measured in 40 male university students.Isometric endurance tests were then performed on all three joints at 50％IPT until exhaustion.Electromyography data and endurance time(ET)of major lower limb muscles were collected concurrently.The differences between ETs predicted by models based on previously recommended F and R parameters and actual ETs were analyzed.Subsequently,experimental ETs were used in a grid search to optimize Fand R parameters,allowing for the development of an accurate three-compartment kinetic model.Results The ET of the hip and ankle joints was significantly longer than that of the knee joint(P＜0.001).Models using previously recommended Fand R parameters overestimated ET,with significantly higher predicted values than experimentally measured ET(P＜0.001),as well as elevated root mean squared error(RMSE)and mean relatvie error(MRE)values.The grid search successfully identified Fand R parameters for the three-compartment model in isometric endurance tests of lower limb joints,with no statistical difference between model-predicted ET and experimental ET(P＞0.05).Conclusions The developed model in this study can serve as an indirect measurement tool for evaluating load in similar activities.

BACKGROUND:Surface electromyography has been extensively utilized for monitoring muscle fatigue. However,traditional electromyographic metrics typically focus on individual muscles and fail to assess the variations in a muscle group during the fatigue process. OBJECTIVE:To establish a muscle functional network to extract complex network parameters and investigate the topological property changes of the muscle functional network under different levels of fatigue,aiming to provide theoretical and methodological foundations for fatigue monitoring and prevention. METHODS:Eleven participants performed single-leg leg press exercise at 50％ of one-repetition maximum until exhaustion. Simultaneously,electromyographic signals of seven muscles (rectus femoris,vastus lateralis,vastus medialis,biceps femoris,tibialis anterior,lateral gastrocnemius,and medial gastrocnemius),electrocardiographic signals,and Borg CR-10 scale scores were collected. The Borg CR-10 scale was used to categorize three fatigue stages:mild,moderate,and severe. Heart rate and heart rate variability were calculated to validate the effective division of fatigue stages. Using the coherence of muscle signals,a muscle functional network was constructed with the seven muscles as nodes,and four complex network parameters (clustering coefficient,average weighted degree,global efficiency,and eigenvector centrality) were extracted. Additionally,four electromyographic indices (root mean square,median frequency,instantaneous mean frequency,and co-activation ratio) were extracted and compared under the three levels of fatigue. RESULTS AND CONCLUSION:(1) Differences in heart rate and heart rate variability were observed across three fatigue stages,indicating the effectiveness of fatigue stage delineation. (2) Electromyographic indicators for different muscles under three levels of fatigue:root mean square and co-activation ratio showed no differences;however,median frequency exhibited robust fatigue trends in vastus lateralis,vastus medialis,and biceps femoris,while instantaneous mean frequency demonstrated robust fatigue trends in rectus femoris,vastus lateralis,vastus medialis,and biceps femoris. Instantaneous mean frequency outperformed median frequency and root mean square,yet all three indicators showed robust trends only for the major working muscle groups,unaffected by fatigue factors,unlike the co-activation ratio. (3) The connectivity strength between vastus lateralis and vastus medialis,vastus lateralis and biceps femoris,vastus lateralis and gastrocnemius medialis,and vastus medialis and biceps femoris gradually increased,showing significant differences in average weighted degree,clustering coefficient,and global efficiency post-fatigue,significantly correlated with fatigue levels. To conclude,changes in connectivity strength reflect the synergy and complementarity among muscles during fatigue. Clustering coefficient,average weighted degree,and global efficiency serve as fatigue markers reflecting overall muscle changes.

Objective:To investigate the clinical characteristics of patients with hepatitis B virus（HBV）-related primary hepatocellular carcinoma（HCC）who were treated in a multidisciplinary team（MDT）for liver cancer，so as to provide a basis for clinical optimization of the diagnosis and treatment of patients with chronic hepatitis B（CHB）.Methods:A retrospective analysis was performed for 482 HBV-related HCC patients who were treated with HCC-MDT every Thursday afternoon in The First Affiliated Hospital of the Army Medical University from January 2022 to May 2024，aged 18-87（55.54±10.84）years，86.93%（419/482）males and 13.07%（63/482）females. According to the different underlying liver diseases at the time of initial medical treatment and the different prognostic outcomes at the later follow-up，the differences in clinical characteristics between groups under different conditions were compared and analyzed，and the influencing factors of HCC prognosis were understood by Logistic regression analysis. Results:At the time of MDT presentation，the differences in HBeAg status（ χ2=6.311 ，P=0.043），γ-glutamyl traspeptidase（GGT）（ Z=6.277， P=0.043），alkaline phosphatase（ALP）（ Z=7.236 ，P=0.027），and model for end-stage liver disease（MELD）scores（ Z=6.111， P=0.047）among patients with different underlying liver diseases were statistically significant. At follow-up，6.75%（11/163）of HBV-related HCC patients who presented to MDT had a family history of HCC，and their cumulative mortality rate was as high as 60.8%（205/337）at least for 1 year. Mulitivariate Logistic regression analysis showed that different underlying liver disease at the time of initial medical treatment，HBV DNA replication level，MELD score and choice of anti-cancer treatment regimen were the influencing factors for the prognosis of HCC（all P<0.05）. The worse the degree of cirrhosis at the initial presentation，the higher the level of HBV DNA replication，and the higher the MELD score，the worse the prognosis for HCC. Conclusion:Advancing the diagnosis and treatment of CHB，maximizing the inhibition of HBV DNA replication，reducing the MELD score，and optimizing the anti-cancer treatment regimen can reduce the mortality rate of HBV-related HCC.