Background Operation and maintenance work in the power grid industry often involving climbing, manual handling, and poor postures causing serious problems like work-related musculoskeletal disorders (WMSDs). The influencing factors of WMSDs are not very clear, but the problem has been widely concerned in this industry. Objective To understand the prevalence and influencing factors of WMSDs among climbing task-involved workers in power supply enterprises. Methods Using a cross-sectional design, a total of 702 workers involving climbing task from 10 power supply enterprises in Jilin Province, Tianjin Municipality, and Shandong province were selected as study subjects using cluster sampling. The Musculoskeletal Disorders Questionnaire which was revised by Lei Yang was used to estimate the prevalence and identify related factors of WMSDs. \begin{document}$ {\chi ^2} $\end{document} test and multiple logistic regression were used to analyze the data. Results A total of 702 subjects were approached, 649 valid questionnaires were recovered, and the effective recovery rate was 92.45%. The prevalence of WMSDs was 81.2%, and neck (65.0%), low back (59.0%), and shoulders (54.4%) were areas of high prevalence of WMSDs. The multiple logistic regression analysis results showed that sometimes and often/very often holding awkward postures were the risk factors of neck, shoulders, low back, knees, upper back, hands/wrists, ankles/feet, elbows, and hips/thighs WMSDs; the OR (95%CI) values were 1.931 (1.260-2.959) and 3.145 (1.810-15.465), 2.700 (1.694-4.305) and 3.888 (2.224-6.798), 1.860 (1.213-2.852) and 3.150 (1.833-5.414), 2.348 (1.456-3.785) and 3.689 (2.130-6.388), 1.782 (1.128-2.815) and 3.274 (1.935-5.538), 1.710 (1.014-2.884) and 2.595 (1.455-4.630), 1.836 (1.019-3.305) and 2.860 (1.526-5.358), 2.250 (1.185-4.275) and 3.032 (1.505-6.108), 2.080 (1.048-4.128) and 3.127 (1.501-6.516), respectively. Department staff shortage was the risk factor of neck, shoulders, low back, upper back, hands/wrists, and ankles/feet WMSDs; the OR (95%CI) values were 1.791 (1.038-3.093), 2.000 (1.119-3.573), 2.506 (1.429-4.394), 2.063 (1.113-3.822), 2.256 (1.069-4.762), and 2.699 (1.103-6.601), respectively. Frequent knee bending was the risk factor of knees, upper back, and hands/wrists WMSDs; the OR (95%CI) values were 1.895 (1.327-2.704), 1.586 (1.131-2.224), and 2.026 (1.390-2.951), respectively. Often pushing/pulling heavy objects was the risk factor of shoulders, low back, and hips/thighs WMSDs; the OR (95%CI) values were 1.485 (1.066-2.192), 1.547 (1.064-2.749), and 1.822 (1.160-2.862), respectively. Long-time heavily neck tilting forward was the risk factor of elbows and hips/thighs WMSDs; the OR (95%CI) values were 1.649 (1.068-2.546) and 2.005 (1.285-3.129) respectively. Long-time ankle or foot bending was the risk factor of ankles/feet and elbows WMSDs; the OR (95%CI) values were 2.481 (1.685-3.655) and 1.655 (1.065-2.571) respectively. Cold or changes in temperature was the risk factor of neck and shoulders WMSDs; the OR (95%CI) values were 2.182 (1.072-4.443) and 2.116 (1.010-4.431) respectively. Exercise was the protective factor of neck, shoulders, low back, upper back, and ankles/feet WMSDs; the OR (95%CI) values were 0.493 (0.363-0.666), 0.625 (0.438-0.888), 0.404 (0.283-0.576), 0.570 (0.408-0.797), and 0.639 (0.436-0.937), respectively. Conclusion The prevalence of WMSDs is high among workers involving climbing task in power supply enterprises, and neck, low back, and shoulders are the most commonly affected body parts. The influencing factors involve awkward postures, repetitive movements, repetitive tasks, pushing/pulling heavy objects, staff shortage, poor working environment, and exercise.

Background Power grid is a basic industry of national economy. The occupational health problems among operation and maintenance workers in this industry have become increasingly prominent in recent years, and they should receive enough attention. Objective To estimate the prevalence of work-related musculoskeletal disorders (WMSDs) of neck and shoulder among operation and maintenance workers of power supply enterprises, and analyze related influencing factors. Methods From March to June 2021, a total of 1433 operation and maintenance worker from 10 power supply enterprises in three provinces of North China were selected as research subjects using cluster sampling method. A revised Musculoskeletal Disorders Questionnaire was used to investigate the prevalence and ergonomic factors of neck and shoulder pain in the past year. χ² test and logistic regression model were used to explore influencing factors of neck and shoulder pain among operation and maintenance workers. Results A total of 1343 valid questionnaires were recovered and the effective recovery rate was 93.72%. The neck pain prevalence was 66.0% (886 cases) and the shoulder pain prevalence was 54.1% (727 cases). The multiple logistic regression analysis results showed that often/very often long-time sitting (OR=1.864, 95%CI: 1.236-2.811; OR=1.659, 95%CI: 1.091-2.524), sometimes holding awkward postures (OR=1.695, 95%CI: 1.294-2.219; OR=1.596, 95%CI: 1.218-2.092), often/very often holding awkward postures (OR=2.416, 95%CI: 1.618-3.607; OR=2.058, 95%CI: 1.405-3.015), long-time slight neck tilting forward (OR=1.327, 95%CI: 1.023-1.722; OR=1.571, 95%CI: 1.221-2.022), long-time elbows bending (OR=1.327, 95%CI: 1.023-1.722; OR=1.506, 95%CI: 1.112-2.040) and department or team staff shortages (OR=1.578, 95%CI: 1.153-2.161; OR=1.831, 95%CI: 1.320-2.539) were associated with higher neck and shoulder pain prevalence rates. While exercise (OR=0.630, 95%CI: 0.492-0.809; OR=0.707, 95%CI: 0.557-0.899) was associated with lower neck and shoulder pain prevalence rates. Doing same work every day (OR=1.704, 95%CI: 1.305-2.225) was associated with a higher neck pain prevalence rate. Awkward postures with ineffectual force (OR=1.808, 95%CI: 1.226-2.665) and often keeping arms above shoulders (OR=1.424, 95%CI: 1.017-1.992) were associated with a higher shoulder pain prevalence rate. Conclusion The prevalence rates of neck and shoulder pian are high among operation and maintenance workers of power supply enterprises in selected three provinces of North China, and the main associated factors include individual factors, awkward work postures, and labor organization.

Background Long working hours is harmful to the physical and mental health of occupational groups, and should receive active attention. Objective To evaluate the current status of long working hours among operation and maintenance workers of power supply enterprises, and explore its effects on work-related musculoskeletal disorders (WMSDs) of the population. Methods From March to June 2021, a cross-sectional survey was conducted among 1433 operation and maintenance workers from 10 power supply enterprises in Jilin Province, Shandong Province, and Tianjin Municipality using cluster sampling. A total of 1433 copies of revised Mus-culoskeletal Disorders Questionnaire were distributed, 1343 questionnaires were recovered, and the recovery rate was 93.72%. The questionnaire included general information, personal health behaviors, weekly working hours, work-related factors, and musculoskeletal pain or discomfort in nine body parts in the past 12 months. χ² test and multiple logistic regression models were used to investigate the relationships between long working hours (>40 h per week) and WMSDs. Results The average age of the workers was (39.42±9.89) years, and the average work experience was 11.00 (5.00, 21.00) years. There were 1158 males (86.22%) and 185 females (13.78%). The average weekly working hours of the workers were (47.98±11.35) h, and the proportion of long working hours (>40 h per week) was 61.06% (820/1343). The proportions of long working hours were higher among the workers with characteristics of male, power distribution, shift work, often/very often long-time standing, often/very often holding awkward postures, often handling heavy objects, limited space to operate, long-time neck tilting backward, keeping arms above shoulders, frequent elbow bending, repeating knee movement every minute, and repeating lower limb or foot movement every minute (all P<0.05). The prevalence rate of WMSDs was 81.53% (1095/1343) among the workers. The results of multiple logistic regression showed that after adjusting education, smoking, exercise, awkward postures, often handling heavy objects, limited space to operate, long-time heavy trunk bending, long-time neck tilting backward, and keeping arms above shoulders, compared with working ≤40 h per week, the risk of WMSDs among workers working >49 h per week was higher (OR=1.406, 95%CI: 1.011-1.955). Conclusion Long working hours is prominent among operation and maintenance workers of power supply enterprises, and increases the risk of reporting WMSDs.

Background Climbing pylons during high-voltage cable maintenance is not only a labor-intensive task, but also a challenge bringing about heat stress and mental pressure from working at height, which may lead to accumulation of muscle fatigue and work-related musculoskeletal disorders. Objective To record the local muscle fatigue during a simulated climbing task by high-voltage cable electricians based on surface electromyography (sEMG) signals, explore the characteristic changes in sEMG signals and their relationship with subjective fatigue evaluation of the task, and provide data support for developing task specific objective assessment tools for local muscle fatigue and prevention of work-related musculoskeletal disorders. Methods Ten male college students were recruited to conduct a test of a simulated pylon climbing task. The climbing distance was 60 m, and a task segment was set for every 20 m (about 100 s), recorded as T1, T2, and T3, respectively. After completing each task segment, the subjects were required to rate their subjective fatigue using the Borg's RPE Scale. Fatigue was defined by rating of perceived exertion (RPE) score ≥ 14 in this study. The sEMG signals of trapezius, erector spinae, rectus femoris, and gastrocnemius muscles were recorded wirelessly. The standardized maximal voluntary electrical activation (MVE) obtained by standardizing the root mean square (RMS) of the time domain index and the median frequency (MF) of the frequency domain index were estimated for the recorded sEMG signals, and joint amplitude and spectrum analysis (JASA) was used to evaluate local muscle fatigue of target muscles involving in the climbing task. Results The RPE scores of T1, T2, and T3 were 11.9, 15.3, and 17.4, respectively. Subjective fatigue was found in T2 and T3 but not in T1. With the extension of climbing time, the MVE values of left and right erector spinae muscles, left and right rectus femoris, and right gastrocnemius muscle increased gradually, while the MVE values of left and right trapezius muscles and left gastrocnemius muscle increased first and then decreased. The MF values of left and right rectus femoris increased at first, then remained unchanged, while the MF values of the other muscles remained basically unchanged. In T1, three muscles, including left trapezius muscle and both side of erector spinae muscles, showed fatigue; in T2, five muscles, including both sides of erector spina muscles, right trapezius muscle, and both sides of gastrocnemius muscle appeared fatigue; in T3 , except for left rectus femoris, the other seven muscles were fatigue. Conclusion The characteristic changes of electromyography signals in the simulated climbing task are not completely consistent with the typical amplitude increase and left shift of the frequency spectrum of sEMG signals in static tasks, indicating that the application of time-domain and frequency-domain analysis methods in the evaluation of muscle fatigue in climbing tasks needs further discussion. Trapezius muscles and erector spinae muscles are the first to show fatigue in the simulation, and may be the sensitive muscle groups of muscle fatigue associated with climbing movement. Compared with subjective evaluation, surface electromyography is more sensitive in the assessment of body fatigue. Fatigue is reported about 100 s of climbing (the climbing length is about 20 m).

With the continuous advancement of health informatization and the wide application of medical big data, electronic health records came into being and spread rapidly. However, because electronic health records contain a large amount of private information, privacy protection is the primary consideration for the sustainable development of electronic health records. By analyzing the shortcomings of privacy protection of electronic health records in law, technology, management and protection consciousness, this paper put forward some countermeasures, such as perfecting the relevant laws and regulations of privacy protection of electronic health records, improving the technical level, improving the management defects of electronic health records, and cultivating the privacy protection consciousness of professionals and the public, so as to improve the overall privacy protection level of China’s health records information management system and provide effective protection for the privacy information of Chinese residents’ electronic health records.

Objective:To investigate the predictive value of abnormal heart rate circadian rhythm for all-cause mortality in stage 5 chronic kidney disease (CKD 5) patients.Methods:The retrospective study was performed in CKD 5 patients enrolled from the First Affiliated Hospital of Nanjing Medical University (Jiangsu Province Hospital) and the Affiliated BenQ Hospital of Nanjing Medical University from February, 2011 to December, 2019. A total of 159 healthy volunteers were enrolled as the healthy control group during the same period. The circadian rhythm of heart rate was monitored by 24-hour Holter. Related indices (including 24-hour, daytime and nighttime mean heart rate, night/day heart rate ratio, 24-hour maximum heart rate, 24-hour minimum heart rate and difference between maximum and minimum of 24-hour heart rate) were calculated. Non-dipping heart rate was defined as night/day heart rate ratio greater than 0.9. Cox regression model was used to analyze the risk factors of all-cause mortality in CKD 5 patients. Kaplan-Meier survival curve and Log-rank test were used to compare the differences of cumulative mortality between high ratio group (night/day heart rate ratio>0.91) and low ratio group (night/day heart rate ratio≤0.91). The nonlinear relationship between night/day heart rate ratio and all-cause mortality was analyzed by restricted cubic spline plot. Time-dependent receiver operating characteristic (ROC) curve was used to analyze the predictive value of night/day heart rate ratio for all-cause mortality in CKD 5 patients.Results:A total of 159 healthy volunteers and 221 CKD 5 patients were included in this study. There were 123 males (55.66%) and the age was (52.72±13.13) years old in CKD 5 patients. The total median follow-up time was 50.0 months. Compared with controls, 24-hour, nighttime mean heart rate, 24-hour minimum heart rate in CKD 5 patients were increased (all P<0.05), furthermore, the night/day heart rate ratio was higher [(0.91±0.09) vs (0.81±0.08), P<0.001], showing "non-dipping heart rate". However, the 24-hour maximum heart rate and the difference between maximum and minimum of 24-hour heart rate in CKD 5 patients were lower than controls (both P<0.05). Multivariate Cox regression analysis showed that the increased night/day heart rate ratio (per 0.1 increase, HR=1.557, 95% CI 1.073-2.258, P=0.020) was an independent influencing factor for all-cause mortality in CKD 5 patients. Kaplan-Meier survival curve analysis showed that the cumulative mortality of the high ratio group was significantly increased than that of the low ratio group (Log-rank test χ 2=7.232, P=0.007). From the restricted cubic spline plot, there was a linear effect between night/day heart rate ratio and all-cause mortality ( P=0.141), and when night/day heart rate ratio was above 0.91, the risk of all-cause mortality was significantly increased in CKD 5 patients. According to time-dependent ROC curve, the accuracy of night/day heart rate ratio in predicting all-cause mortality was 70.90% even when the survival time was up to 70.0 months. Conclusions:The circadian rhythm of heart rate in CKD 5 patients displays "non-dipping" state. High night/day heart rate ratio is an independent influencing factor for all-cause mortality in CKD 5 patients.

Objective:To observe heart rate circadian rhythm in patients with chronic kidney disease (CKD) stage 5 and to analyze the effects of parathyroidectomy (PTX) on heart rate circadian rhythm in severe secondary hyperparathyroidism (SHPT) patients.Methods:A cross-sectional observation was performed in 213 patients with CKD stage 5 and 96 controls, and the patients were divided into those with severe SHPT (PTX group, n=70) and without severe SHPT (non-PTX group, n=143). Forty-six PTX patients were followed up prospectively. The baseline data were compared among these groups. Holter electrocardiogram was performed for each participant. Non-dipping heart rate was defined as night/day heart rate ratio greater than 0.9. Multiple linear regression analysis was used to analyze the related factors of heart rate circadian rhythm in patients with CKD stage 5. Results:The 24-hour, daytime and nighttime mean heart rate in patients with CKD stage 5 were all higher than those in controls, especially in PTX group (all P<0.05). The night/day heart rate ratios of controls and CKD stage 5 patients were (0.81±0.08) and (0.91±0.08) respectively ( P<0.01). Correlation analysis showed 24-hour and daytime or nighttime mean heart rate in patients with CKD stage 5 were positively correlated with serum levels of phosphorus and ln(alkaline phosphatase), while nighttime mean heart rate and night/day heart rate ratio were positively related with serum intact parathyroid hormone level. After adjusting with postoperative follow-up period (median time: 10.9 months), 24-hour and nighttime mean heart rate, and night/day heart rate ratio in PTX patients all decreased significantly (all P<0.01). Conclusions:Heart rate is increased and circadian rhythm is abnormal in patients with CKD stage 5, which are related with mineral and bone disorder. PTX significantly decreases 24-hour and nighttime mean heart rate in severe SHPT patients, and improves the heart rate circadian rhythm.

Objective:To evaluate the volume status of hemodialysis patients with hypertension by bioelectrical impedance vector analysis, and investigate the effect of high volume status on the prognosis of patients with hypertension.Methods:The study subjects came from the patients with pre-dialysis systolic blood pressure>160 mmHg (mean systolic blood pressure of 6 times of treatment) in the Affiliated BenQ Hospital of Nanjing Medical University. According to the volume status assessed by bioelectrical impedance vector analysis, patients were divided into two groups: fluid overload group and non-overload group (including normal fluid status and fluid decline). The clinical data, laboratory test results, ratio of intracellular and extracellular water (ICW and ECW), body cell mass, lean body mass and the percentage of total body weight, fat percentage of body weight, resistance/height, reactance/height, phase angle and illmarker were compared between two groups. Kaplan-Meier survival curve was used to compare the difference of survival rate between the two groups.Results:A total of 51 hemodialysis patients with hypertension were enrolled in this study, including 19 patients in fluid overload group and 32 patients in non-overload group (27 patients with normal volume status and 5 patients with decreased volume). The levels of albumin, prealbumin, hemoglobin, hematocrit and serum phosphorus in patients with fluid overload decreased significantly compared with non-overload patients (all P<0.05), and the proportion of lymphocytes increased in fluid-overload patients ( P<0.05). The ratio of extracellular water and illmarker index in fluid overload group were significantly higher than those in the other group (both P<0.01). However, phase angle, resistance/height, reactance/height were lower than those in patients with non-overload (all P<0.01). After 20 months of clinical observation, the control rate of blood pressure (pre-dialysis systolic blood pressure<160 mmHg) in fluid overload group was lower than that in the non-overload group (26.3% vs 43.8%), but not statistically significant ( P=0.218). The all-cause mortality rate of patients in the fluid overload group was higher than non-overload group (26.3% vs 15.6%). Kaplan-Meier survival curve analysis suggested that the difference in survival rate between the two groups was not statistically significant. Conclusions:The extracellular fluid of hemodialysis patients with hypertension and fluid overload increases significantly, and the nutritional status evaluation index decreases compared with that of patients without increased volume. Increased proportion of lymphocytes may be related to the micro-inflammatory status. Blood pressure is more difficult to control in hypertensive patients with fluid overload and the clinical prognosis can be worse in patients without increased volume.

Objective:To explore the potential mechanism of sorafenib resistance associated long non-coding RNA (lncRNA-SRLR) promoted invasion and metastasis in U2OS osteosarcoma cells.Methods:We transfected U2OS cells with negative control lentivirus (LV-NC) or lncRNA-SRLR overexpressed lentivirus (LV-over/SRLR) particles. LV-NC and LV-over/SRLR stable transfected cells (U20S/NC and U20S/SRLR) were selected by primary cell culture medium containing puromycin. The mRNA expressions of lncRNA-SRLR and procollagen-lysine, procollagen-lysine 2-oxoglutarate 5-dioxygenase 2 (PLOD2) were detected by quantitative real-time polymerase chain reaction (qRT-PCR). The effect of lncRNA-SRLR on the invasion of U2OS cells were determined by wound-healing assay and Transwell migration assay. The effect of SRLR on the interleukin-6 (IL-6) secretion of U2OS cells was evaluated by enzyme-linked immunosorbent assay (ELISA) analysis. The subcellular distribution of SRLR in U2OS cells was detected by fluorescence in situ hybridization (FISH) analysis.The expression of PLOD2 in cells was detected by immunofluorescence (IF). The expressions of PLOD2 and focal adhesion kinase (FAK)/signal transducer and activator of transcription 3 (STAT3) signal pathway related proteins in U2OS/NC and U2OS/SRLR cells were detected by western blotting.Results:qRT-PCR assay showed that mRNA expressions of lncRNA-SRLR and PLOD2 in U2OS/SRLR cells were (3 964.97±0.05) and (2.77±0.11), respectively, significantly higher than those in U2OS/NC cells ( P<0.001 or P<0.01). The results of wound-healing and Transwell migration assay showed that over-expression of SRLR markedly promoted the invasion ability of U2OS cells ( P<0.05). The result of ELISA analysis showed that the IL-6 secretions in U2OS/NC or U2OS/SRLR cells were (125.38±11.22) pg/ml or (119.97±13.43) pg/ml, without statistical significance ( P>0.05). The subcellular distribution assay revealed that lncRNA-SRLR is predominately located in the nucleus. The result of IF showed that compared with U2OS/NC cells, the expression of PLOD2 was up-regulated in U2OS/SRLR cells. The result of western blotting showed that over-expression of SRLR significantly increased the expression levels of PLOD2, phosphorylation (p)-FAK and p-STAT3 in U2OS cells ( P<0.01). Conclusion:lncRNA-SRLR promotes invasion and metastasis of osteosarcoma by activating PLOD2-FAK/STAT3 signal axis.

Objective:To explore the potential mechanism of sorafenib resistance associated long non-coding RNA (lncRNA-SRLR) promoted invasion and metastasis in U2OS osteosarcoma cells.Methods:We transfected U2OS cells with negative control lentivirus (LV-NC) or lncRNA-SRLR overexpressed lentivirus (LV-over/SRLR) particles. LV-NC and LV-over/SRLR stable transfected cells (U20S/NC and U20S/SRLR) were selected by primary cell culture medium containing puromycin. The mRNA expressions of lncRNA-SRLR and procollagen-lysine, procollagen-lysine 2-oxoglutarate 5-dioxygenase 2 (PLOD2) were detected by quantitative real-time polymerase chain reaction (qRT-PCR). The effect of lncRNA-SRLR on the invasion of U2OS cells were determined by wound-healing assay and Transwell migration assay. The effect of SRLR on the interleukin-6 (IL-6) secretion of U2OS cells was evaluated by enzyme-linked immunosorbent assay (ELISA) analysis. The subcellular distribution of SRLR in U2OS cells was detected by fluorescence in situ hybridization (FISH) analysis.The expression of PLOD2 in cells was detected by immunofluorescence (IF). The expressions of PLOD2 and focal adhesion kinase (FAK)/signal transducer and activator of transcription 3 (STAT3) signal pathway related proteins in U2OS/NC and U2OS/SRLR cells were detected by western blotting.Results:qRT-PCR assay showed that mRNA expressions of lncRNA-SRLR and PLOD2 in U2OS/SRLR cells were (3 964.97±0.05) and (2.77±0.11), respectively, significantly higher than those in U2OS/NC cells ( P<0.001 or P<0.01). The results of wound-healing and Transwell migration assay showed that over-expression of SRLR markedly promoted the invasion ability of U2OS cells ( P<0.05). The result of ELISA analysis showed that the IL-6 secretions in U2OS/NC or U2OS/SRLR cells were (125.38±11.22) pg/ml or (119.97±13.43) pg/ml, without statistical significance ( P>0.05). The subcellular distribution assay revealed that lncRNA-SRLR is predominately located in the nucleus. The result of IF showed that compared with U2OS/NC cells, the expression of PLOD2 was up-regulated in U2OS/SRLR cells. The result of western blotting showed that over-expression of SRLR significantly increased the expression levels of PLOD2, phosphorylation (p)-FAK and p-STAT3 in U2OS cells ( P<0.01). Conclusion:lncRNA-SRLR promotes invasion and metastasis of osteosarcoma by activating PLOD2-FAK/STAT3 signal axis.