Objective To investigate the prevalence and influencing factors of work-related musculoskeletal disorders (WMSDs) in neck, shoulders and lower back among power grid workers. Methods A total of 371 workers from a power grid enterprise in Guangdong Province were selected as the research subjects using the convenience sampling method. A cross-sectional survey of WMSDs in the neck, shoulders and waist of the workers was conducted using the modified Musculoskeletal Disorders Questionnaire. Results The overall prevalence of WMSDs among the power grid workers was 62.8%, with prevalence of 37.2%, 33.7% and 32.1% for WMSDs in neck, shoulders and lower back, respectively. Binary logistic regression analysis showed that power grid workers who did not maintain a good sitting posture or were unable to maintain good sitting posture over prolonged periods had a higher risk of neck WMSDs than those who maintained a good sitting posture (both P<0.01). A higher frequency of head-down posture during work was associated with an increased risk of neck WMSDs (both P<0.05). Female workers had a higher risk of shoulder WMSDs than male workers (P<0.05). A higher frequency of early awakening with inability to fall back asleep, as well as a higher frequency of head-down posture during work, were both associated with an increased risk of shoulder WMSDs (all P<0.05). Workers with a sedentary habit had a higher risk of shoulder WMSDs than those without (P<0.01). Workers with insufficient rest time had a higher risk of shoulder WMSDs than those with sufficient rest time (P<0.01). Both maintenance workers and managers had a higher risk of lower back WMSDs than workers in other occupational categories (all P<0.05). Workers who experienced nocturnal awakening with difficulty falling back asleep at frequency of several times per year, ≥1 time /month, ≥1 time /week, had higher risk of lower back WMSDs than those who never experienced such problem (all P<0.05). Workers with a sedentary habit and those uncertain about having a sedentary habit both had a higher risk of lower back WMSDs than those without (both P<0.05). Greater forward neck flexion during work was associated with an increased risk of lower back WMSDs (both P<0.05). Workers who occasionally tilted their necks to the side while working had a higher risk of lower back WMSDs than those who did not (P<0.05). Conclusion WMSDs are highly prevalent among power grid workers, particularly affecting the neck, shoulder, and waist. Influencing factors include individual characteristics, behavioral habits, work organization, work posture, and workload. Maintaining proper posture and adequate rest may reduce the risk of WMSDs.

Objectives:To investigate the clinical value of cardiac magnetic resonance imaging(CMR)feature-tracking strain analysis in risk stratification of diabetic heart failure with preserved ejection fraction(HFpEF).Methods:In this retrospective study,a total of 215 patients with diabetic HFpEF who underwent CMR at Chinese Academy of Medical Sciences Fuwai Hospital from January 2012 to December 2018 were included.Myocardial strain parameters were calculated using CMR feature-tracking technology.Patients were followed up by medical records or telephone calls.Composite endpoint event,all-cause death or heart failure hospitalization during follow-up were recorded.Patients were divided into event group and event-free group.Univariable and multivariable Cox proportional hazard regression analyses were performed to determine the risk factors for the outcomes in diabetic HFpEF.The effects of hypertension and obesity on the prognosis of diabetic HFpEF patients and whether they affect the prognostic value of CMR feature-tracking strain analysis were also analyzed.Results:During a follow-up of(7.1±1.8)years,93(43.3%)patients had endpoint events(event group),including 28 all-cause deaths and 65 heart failure hospitalization.Compared with the event-free group(n=122),patients in the event group had significantly lower left ventricular ejection fraction,higher prevalence and extent of late gadolinium enhancement,and significantly reduced global longitudinal strain(GLS),global circumferential strain,global radial strain,and global systolic longitudinal strain rate(all P<0.05).The absolute GLS value was significantly lower in event group than in event-free group,regardless of the presence of hypertension and obesity.Multivariate Cox regression analysis showed that estimated glomerular filtration rate(HR=0.983,95%CI:0.972-0.993,P=0.001),left atrial volume index(HR=1.015,95%CI:1.005-1.026,P=0.004),and GLS(HR=1.142,95%CI:1.060-1.231,P<0.001)were independent risk factors for adverse cardiovascular events in diabetic HFpEF patients.However,adjusted N-terminal pro-brain natriuretic peptide was not an independent prognostic factor.The cut-offvalue of GLS to predict outcome was-14.09%from ROC curve analysis.The Kaplan-Meier curve showed that in patients with and without hypertension and obesity,patients with the GLS>-14.09%had lower event-free survival compared to patients with GLS≤-14.09%(all P<0.05),and the ability of GLS to predict adverse outcomes was not affected by hypertension and obesity.Conclusions:GLS obtained by CMR feature-tracking strain analysis is an independent predictor of adverse outcomes in diabetic HFpEF,and its ability to predict adverse outcomes is independent of hypertension and obesity.

[Objective]To establish a risk recognition model for coronary artery stenosis by using a machine learning method and to identify the key causative factors.[Methods]Patients aged≥18 years,diagnosed with coronary heart disease through coronary angiography from January 2013 to May 2020 in two prominent hospitals in Shanxi Province,were continuously enrolled.Logistic regression,back propagation neural network(BPNN),and random forest(RF)algorithms were used to construct models for detecting the causative factors of coronary artery stenosis.Sensitivity(TPR),specificity(TNR),accuracy(ACC),positive predictive value(PV+),negative predictive value(PV-),area under subject operating characteristic curve(AUC),and calibration curve were used to compare the discrimination and calibration performance of the models.The best model was then employed to predict the main risk variables associated with coronary stenosis.[Results]The RF model exhibited superior comprehensive performance compared to logistic regression and BPNN models.The TPR values for logistic regression,BPNN,and RF models were 75.76%,74.30%,and 93.70%,while ACC values were 74.05%,72.30%,and 79.49%,respectively.The AUC values were:logistic regression 0.739 9;BPNN 0.723 1;RF 0.752 2.Manifestations such as chest pains,abnormal ST segments on ECG,ventricular premature beats with hypertension,atrial fibrillation,regional wall motion abnormalities(RWMA)by color echocardiography,aortic regurgitation(AR),pulmonary insufficiency(PI),family history of cardiovascular diseases,and body mass index(BMI)were identified as top ten important variables affecting coronary stenosis according to the RF model.[Conclusions]Random forest model shows the best comprehensive performance in identification and accurate assessment of coronary artery stenosis.The prediction of risk factors affecting coronary artery stenosis can provide a scientific basis for clinical intervention and help to formulate further diagnosis and treatment strategies so as to delay the disease progression.

Objective:To study the effect of repetitive facilitative exercise (RFE) combined with repetitive transcranial magnetic stimulation (rTMS) on upper limb motor function in subacute stroke patients.Methods:A total of 80 patients with subacute stroke diagnosed and treated in the First Affiliated Hospital of Wenzhou Medical University from November 2023 to March 2024 were prospectively selected and divided into control group, RFE group, RFE+ low frequency rTMS group and RFE+ high frequency rTMS group by random number table method, with 20 cases in each group. The control group received conventional rehabilitation therapy, the RFE group received conventional rehabilitation therapy +RFE, the RFE+ low frequency rTMS group received conventional rehabilitation therapy +RFE+ low frequency (1 Hz) rTMS therapy, and the RFE+ high frequency rTMS group received conventional rehabilitation therapy +RFE+ high frequency (10 Hz) rTMS therapy. All of four groups were treated continuously for 2 weeks. The changes of Fugl-Meyer Scale (Motor Function) Upper Limb (FMA-UE) score, Modified Ashworth Scale (MAS) score, Modified Barthel Index (MBI) score, hemiplegic hand grip strength and BrunnstromScale (BRSS) score before and after treatment were compared among the four groups.Results:There were no statistical differences in the FMA-UE score, MAS grade, MBI score and hemiplegic hand grip strength among the four groups before treatment ( P>0.05). After treatment, the FMA-UE, MBI scores and hemiplegic hand grip strength were increased in the four groups, and MAS grade were decreased, there were statistical differences ( P<0.05). RFE+ low-frequency rTMS group had the highest FMA-UE, MBI score and hemiplegic hand grip strength, and MAS grade was the lowest, and compared with RFE+ high-frequency rTMS group, there were statistical differences : (43.65 ± 2.11) scores vs. (40.95 ± 2.12) scores, (49.20 ± 4.06) scores vs. (44.80 ± 2.48) scores, (32.45 ± 2.59) kg vs. (29.30 ± 2.94) kg, (0.37 ± 0.09) grade vs. (0.56 ± 0.10) grade, P<0.01. The BRSS unupgradingrate among the four groups after treatment were 10/20, 8/20, 2/20, 5/20, there was statistical difference ( χ2 = 8.65, P = 0.031), and the RFE+ low-frequency rTMS group had the lowest number of BRSS unupgraded cases. Conclusions:The efficacy of RFE combined with low-frequency rTMS in the treatment of subacute stroke is obvious, which is conducive to promoting the recovery of muscle strength, grip strength and motor function of the hemiplegic side of the patients.

Objective:To investigate the essential determinants that are critical to initiating the assembly of outer membrane proteins by replacing the POTRA domains of the translocator protein FhaC and the insertase protein TtOmp85 of the Omp85 family. Methods:FhaC, TtOmp85 proteins and their recombinant chimeric proteins after replacing the POTRA domain were obtained by overexpression and purification in vitro. An in vitro reconstitution system was used to investigate the effects of the different domains on the transport efficiency of the substrate outer membrane protein FhaB and the membrane insertion efficiency of OmpA. Results:Replacing the POTRA domain of FhaC with that of TtOmp85 led to the loss of the transport function of FhaB. During the membrane insertion process of OmpA, the FhaC mutant containing the POTRA of TtOmp85 protein acquired the ability to assemble OmpA. Conclusion:The compositional differences in the POTRA domain of Omp85 family proteins determine their abilities to recognize their substrate proteins.

Objective:To study the effect of repetitive facilitative exercise (RFE) combined with repetitive transcranial magnetic stimulation (rTMS) on upper limb motor function in subacute stroke patients.Methods:A total of 80 patients with subacute stroke diagnosed and treated in the First Affiliated Hospital of Wenzhou Medical University from November 2023 to March 2024 were prospectively selected and divided into control group, RFE group, RFE+ low frequency rTMS group and RFE+ high frequency rTMS group by random number table method, with 20 cases in each group. The control group received conventional rehabilitation therapy, the RFE group received conventional rehabilitation therapy +RFE, the RFE+ low frequency rTMS group received conventional rehabilitation therapy +RFE+ low frequency (1 Hz) rTMS therapy, and the RFE+ high frequency rTMS group received conventional rehabilitation therapy +RFE+ high frequency (10 Hz) rTMS therapy. All of four groups were treated continuously for 2 weeks. The changes of Fugl-Meyer Scale (Motor Function) Upper Limb (FMA-UE) score, Modified Ashworth Scale (MAS) score, Modified Barthel Index (MBI) score, hemiplegic hand grip strength and BrunnstromScale (BRSS) score before and after treatment were compared among the four groups.Results:There were no statistical differences in the FMA-UE score, MAS grade, MBI score and hemiplegic hand grip strength among the four groups before treatment ( P>0.05). After treatment, the FMA-UE, MBI scores and hemiplegic hand grip strength were increased in the four groups, and MAS grade were decreased, there were statistical differences ( P<0.05). RFE+ low-frequency rTMS group had the highest FMA-UE, MBI score and hemiplegic hand grip strength, and MAS grade was the lowest, and compared with RFE+ high-frequency rTMS group, there were statistical differences : (43.65 ± 2.11) scores vs. (40.95 ± 2.12) scores, (49.20 ± 4.06) scores vs. (44.80 ± 2.48) scores, (32.45 ± 2.59) kg vs. (29.30 ± 2.94) kg, (0.37 ± 0.09) grade vs. (0.56 ± 0.10) grade, P<0.01. The BRSS unupgradingrate among the four groups after treatment were 10/20, 8/20, 2/20, 5/20, there was statistical difference ( χ2 = 8.65, P = 0.031), and the RFE+ low-frequency rTMS group had the lowest number of BRSS unupgraded cases. Conclusions:The efficacy of RFE combined with low-frequency rTMS in the treatment of subacute stroke is obvious, which is conducive to promoting the recovery of muscle strength, grip strength and motor function of the hemiplegic side of the patients.

Objectives:To investigate the clinical value of cardiac magnetic resonance imaging(CMR)feature-tracking strain analysis in risk stratification of diabetic heart failure with preserved ejection fraction(HFpEF).Methods:In this retrospective study,a total of 215 patients with diabetic HFpEF who underwent CMR at Chinese Academy of Medical Sciences Fuwai Hospital from January 2012 to December 2018 were included.Myocardial strain parameters were calculated using CMR feature-tracking technology.Patients were followed up by medical records or telephone calls.Composite endpoint event,all-cause death or heart failure hospitalization during follow-up were recorded.Patients were divided into event group and event-free group.Univariable and multivariable Cox proportional hazard regression analyses were performed to determine the risk factors for the outcomes in diabetic HFpEF.The effects of hypertension and obesity on the prognosis of diabetic HFpEF patients and whether they affect the prognostic value of CMR feature-tracking strain analysis were also analyzed.Results:During a follow-up of(7.1±1.8)years,93(43.3%)patients had endpoint events(event group),including 28 all-cause deaths and 65 heart failure hospitalization.Compared with the event-free group(n=122),patients in the event group had significantly lower left ventricular ejection fraction,higher prevalence and extent of late gadolinium enhancement,and significantly reduced global longitudinal strain(GLS),global circumferential strain,global radial strain,and global systolic longitudinal strain rate(all P<0.05).The absolute GLS value was significantly lower in event group than in event-free group,regardless of the presence of hypertension and obesity.Multivariate Cox regression analysis showed that estimated glomerular filtration rate(HR=0.983,95%CI:0.972-0.993,P=0.001),left atrial volume index(HR=1.015,95%CI:1.005-1.026,P=0.004),and GLS(HR=1.142,95%CI:1.060-1.231,P<0.001)were independent risk factors for adverse cardiovascular events in diabetic HFpEF patients.However,adjusted N-terminal pro-brain natriuretic peptide was not an independent prognostic factor.The cut-offvalue of GLS to predict outcome was-14.09%from ROC curve analysis.The Kaplan-Meier curve showed that in patients with and without hypertension and obesity,patients with the GLS>-14.09%had lower event-free survival compared to patients with GLS≤-14.09%(all P<0.05),and the ability of GLS to predict adverse outcomes was not affected by hypertension and obesity.Conclusions:GLS obtained by CMR feature-tracking strain analysis is an independent predictor of adverse outcomes in diabetic HFpEF,and its ability to predict adverse outcomes is independent of hypertension and obesity.

Objective:To investigate the essential determinants that are critical to initiating the assembly of outer membrane proteins by replacing the POTRA domains of the translocator protein FhaC and the insertase protein TtOmp85 of the Omp85 family. Methods:FhaC, TtOmp85 proteins and their recombinant chimeric proteins after replacing the POTRA domain were obtained by overexpression and purification in vitro. An in vitro reconstitution system was used to investigate the effects of the different domains on the transport efficiency of the substrate outer membrane protein FhaB and the membrane insertion efficiency of OmpA. Results:Replacing the POTRA domain of FhaC with that of TtOmp85 led to the loss of the transport function of FhaB. During the membrane insertion process of OmpA, the FhaC mutant containing the POTRA of TtOmp85 protein acquired the ability to assemble OmpA. Conclusion:The compositional differences in the POTRA domain of Omp85 family proteins determine their abilities to recognize their substrate proteins.

Objectives:To investigate the clinical feasibility of three-dimensional(3D)high-resolution late gadolinium enhancement(LGE)MRI in accessing left atrial myocardial fibrosis in patients with atrial fibrillation(AF). Methods:A total of 34 AF patients referred for hybrid surgical ablation were retrospectively enrolled in this study.3D-LGE-MRI images were acquired by Siemens 3.0 T machine and analyzed by ADAS post-processing software by two experienced radiologists to obtain parameters such as the area and the area percentage of LGE.Regional analysis was performed by one of the two radiologists at ten left atrial segments.The Kappa test was used to assess the agreement for scoring image quality,and the interclass correlation coefficient(ICC)was used to evaluate the interobserver agreement of LGE parameters.The parameters of left atrial morphology,area(and area percentage)of LGE,and location of LGE were compared between patients with persistent AF and paroxysmal AF. Results:Images of all 34 patients were considered to have diagnostic value.The scores of the overall image quality and the clarity of the left atrial wall evaluated by two radiologists were(2.88±0.64)points and(3.26±0.75)points(radiologist 1),(2.97±0.58)points and(3.24±0.70)points(radiologist 2),respectively.The corresponding Kappa values were 0.724 and 0.859.Both the area and the area percentage of LGE showed good consistency among observers,and the ICCs were 0.969 and 0.950,respectively.The difference in the area of LGE and the area percentage of LGE between patients with paroxysmal and persistent atrial fibrillation was similar(both P＞0.05).Compared with patients with paroxysmal AF,patients with persistent AF had a higher Utah stage and more severe myocardial fibrosis in the right inferior pulmonary vein antrum and the left atrial septum(all P＜0.05). Conclusions:3D high-resolution LGE-MRI provides a non-invasive way to visualize and quantify left atrial myocardial fibrosis.The extent of left atrial fibrosis in patients with persistent AF is more severe than that in patients with paroxysmal AF,with a preferential distribution in the right inferior pulmonary vein antrum and the left atrial septum.

Objectives:To analyze the consistency of evaluating left ventricular hemodynamics (HDF) based on single plane and multi plane cine sequences of magnetic resonance mitral valve orifice.Methods:A prospective study was conducted on 48 healthy adults, and two methods were used to measure the mitral valve diameter and calculate HDF parameters. The first method was to measure the diameter of the mitral valve opening in the left ventricular three chamber cine sequence; The second method is to measure the mitral valve diameter using cine sequences of two chamber, three chamber, and four chamber hearts, and then take the average value. Paired t-tests were used to compare the differences in HDF measured by two methods, and Pearson correlation coefficient ( r), intra group correlation coefficient ( ICC), and Bland-Altman analysis were used to test the consistency and reproducibility of the two methods. Results:The root mean square (RMS) of longitudinal HDF calculated using single plane and multi plane mitral valve diameters were [(17.28±4.41)% vs (17.21±4.61)%] ( P=0.379) for the entire cardiac cycle, [(21.45±5.54)% vs (21.49±5.68)%] ( P=0.646) for systolic phase, and [(12.78±4.10)% vs (12.54±4.24)%] ( P=0.106) for diastolic phase, respectively. The difference in the calculation results of HDF parameters related to ventricular function was not statistically significant (all P>0.05), and there was good consistency ( r=0.924-0.996, ICC=0.924-0.995). The two HDF parameters related to atrial function were sensitive to the measurement method of mitral valve orifice diameter [RMS of longitudinal HDF during active atrial emptying: (3.26±1.51)% vs (3.32±1.55)%, P=0.006; longitudinal HDF pulse during active atrial emptying: (-2.60±1.28)% vs (-2.76±1.30)%, P<0.001]. Conclusions:The ventricular function related HDF parameters obtained from the analysis of mitral valve orifice diameter using single plane and multi plane methods have good consistency, and can be evaluated using relatively simple single plane methods for left ventricular HDF.