Background Fatigue among distribution network live-line workers in complex operational environments has become increasingly severe and requires widespread attention. Objective To investigate the positive rates of fatigue and associated influencing factors of live-line power distribution workers, and to make a reasonable strategy to reduce the fatigue of front-line workers. Methods Power supply companies in Guangdong, Guangxi, and Yunnan provinces were selected by cluster sampling in 2023, and all front-line live-line workers in the selected companies were recruited. The questionnaire used in this study consisted of two parts: one was the Fatigue Scale-14 (FS-14) for investigating fatigue status and the other was for associated influencing factors. A FS-14 score greater than 3 points was defined as fatigue. \begin{document}$ {\chi }^{2} $\end{document} test and logistic regression were employed to analyze the factors affecting fatigue. Results A total of 1341 questionnaires were distributed, and 1217 valid questionnaires were recovered, with a valid response rate of 90.75%. The average fatigue score of the participants was (6.84±3.79) points, and a total of 1054 participants scored over 3, resulting a fatigue positive rate of 86.6%. The logistic regression model showed that working under extreme weather (OR=2.03, 95%CI: 1.38, 2.98), overtime 2-3 times a week (OR=5.24, 95%CI: 1.28, 21.40), overtime everyday (OR=6.95, 95%CI: 1.71, 28.27), frequent wrist rotation (OR=1.95, 95%CI: 1.08, 3.51), and leaning back slightly (OR=2.94, 95%CI: 1.19, 7.28) associated with higher positive rates of fatigue. Conclusion The high positive rate of fatigue among live-line power distribution workers suggests severe fatigue issues. Extreme weather conditions, working overtime frequency, and maintaining wrist rotation and backward bending postures during work are main factors affecting their fatigue.

Background When live working line operators engage in upper limb operations, working for a long time with raising arms and the exposure to adverse ergonomic factors tend to increase muscle load, cause fatigue accumulation, and increase the risk of work-related musculoskeletal disorders (WMSDs). Objective To analyze work posture and associated muscle fatigue during executing breaking/connecting contact terminal, and identify adverse ergonomic factors of the work process. Methods This study recruited 10 volunteers to perform breaking/connecting contact terminal simulation. At a distance of 4.5, 3.5, and 2.5 m from the body to the wire, each performed the task 5 times. Visual 3D was used to analyze the kinematic data from motion capture. The surface electromyography (sEMG) signals of the deltoid, biceps, triceps, and brachioradialis were recorded during the simulation and analyzed for muscle fatigue using root mean square (RMS), median frequency (MF), and jointed EMG amplitude and spectrum analysis (JASA). After completion of each task, Borg scale was used to query the volunteers of their subjective fatigue. A 2-min rest was required between each distance. Results The kinematic data from motion capture showed that in the entire process of the task, the right upper limb was higher when lifting, with the right shoulder joint maintaining flexion and fluctuating periodically between abduction and adduction, external and internal rotation, the right elbow joint maintaining flexion and supination. The frequency of task cycle showed a significant effect on the Borg scale scores (P<0.001, partial \begin{document}$ {\eta }^{2} $\end{document}=0.464); the distance showed no significant effect on the Borg scale scores (P>0.05, partial \begin{document}$ {\eta }^{2} $\end{document}=0.002); their interaction effect was not significant (P>0.05, partial \begin{document}$ {\eta }^{2} $\end{document}=0.020). The results of the sEMG signals showed that at a distance of 4.5 m, the volunteers had the highest percentages of maximal voluntary electrical activation (MVE%) in the deltoid and right brachioradialis and the lowest MF values in the deltoid and left brachioradialis after completing 5 task cycles. The results of JASA showed that fatigue was observed in brachioradialis and deltoid after completing 5 task cycles at a distance of 4.5 m, the right deltoid and right brachioradialis at a distance of 3.5 m, in the brachioradialis, deltoid, and left bicep at a distance of 2.5 m. Conclusion The subjective fatigue of workers who engaged in breaking/connecting contact terminal elevates with more repetitive operations. Based on the sEMG and motion capture analysis, it can be found that improper distance between the workers and the target work area can increase the burden from poor posture and improper use of work equipment, and lead to muscle fatigue; the deltoid and brachioradialis are the key muscles of fatigue in this type of operation; changing the angle of the elbow joint and the shoulder joint during the process of the operation can affect the deltoid and brachioradialis exertion and loading.

Background Power grid is an important component of the national infrastructure. The occupational health issues among the workers in this industry are attracting great concern nationwide. Objective To investigate the prevalence of work-related musculoskeletal disorders (WMSDs) in neck and shoulder among the power distribution workers of power supply enterprises, and analyze the related influencing factors. Method In April 2023, a total of 1244 workers in 50 municipal power supply bureaus were randomly selected from the three provinces under China Southern Power Grid using cluster sampling method. The questionnaire used in the study was based on a revised Musculoskeletal Disorders Questionnaire and added ergonomic load of upper limb work. \begin{document}$ {\chi }^{2} $\end{document} test and logistic regression model were used to explore the influencing factors of neck pain and shoulder pain among the subjects. Results A total of 1244 valid questionnaires were recovered and the effective recovery rate was 90.87%(1244/1369). The positive rates of neck pain and shoulder pain were 45.5% (566 cases) and 36.3% (452 cases) respectively. The logistic regression analysis results showed that more than 20 years working age (OR=2.27, 95%CI: 1.39, 3.96; OR=2.56, 95%CI: 1.53, 4.26), often (OR=2.08, 95%CI: 1.35, 3.20; OR=2.40, 95%CI: 1.50, 3.58)/quite often (OR=2.96, 95%CI: 1.73, 5.04; OR=2.72, 95%CI: 1.49, 4.94) maintaining a forced posture, and working immediately after break (OR=1.72, 95%CI: 1.04, 2.85; OR=2.14, 95%CI: 1.19, 3.88) were associated with a higher positive rate of neck pain and shoulder pain respectively. Feeling sufficient rest (OR=0.61, 95%CI: 0.47, 0.80; OR=0.63, 95%CI: 0.50, 0.83) and opportunity to decide when to take breaks (OR=0.72, 95%CI: 0.53, 0.98; OR=0.62, 95%CI: 0.41, 0.93) were associated with a lower positive rate of neck pain and shoulder pain respectively. Conclusion The positive rates of neck pain and shoulder pain are high among power distribution workers. The main influencing factors included long working age, quite often maintaining a forced posture, and working immediately after break.

Objective To evaluate the clinical characteristics of human immunodeficiency virus (HIV) infected patients with peripheral lung masses (PLMs), and to assess the diagnostic utility of contrast-enhanced ultrasound (CEUS) in differentiating benign and malignant PLMs. Methods A retrospective analysis was performed on the clinical data of 69 patients with PLM treated in Shanghai Public Health Clinical Center from January 2020 to December 2023. All patients underwent percutaneous biopsy, and were categorized into benign group (n＝36) and malignant group (n＝33). 25 patients were HIV-positive and 44 patients were HIV-negative. The clinical features and CEUS parameters in patients were compared across these groups. Results Patients with malignant masses were significantly older than those with benign masses (P＜0.05). In the malignant group, HIV-negative patients exhibited significantly larger tumor diameters compared to HIV-positive patients (P＜0.05); in the HIV-positive patients, no significant difference in tumor size was observed between benign and malignant masses. 19 patients underwent CEUS. 10 malignant masses, irrespective of HIV status (10 positive and 9 negative), commonly presented with indistinct margins, delayed enhancement, heterogeneous perfusion, and delayed peak enhancement on CEUS. 9 benign masses showed earlier peak enhancement compared to 10 malignant masses (P＜0.05); no significant differences were observed in the initiation and washout time of enhancement between benign and malignant masses. In HIV-positive patients, 5 benign masses frequently demonstrated discrepancies between CEUS findings and pathological results. Conclusions The clinical and CEUS characteristics were different between benign and malignant PLMs. However, CEUS shows limited accuracy in distinguishing benign and malignant PLMs, underscoring the need for pathological confirmation.

ObjectiveTo investigate the processing technology of calcined Haematitum based on the concept of quality by design（QbD） and to assess its health risk. MethodsTaking whole iron content， Fe²⁺ dissolution content and looseness as critical quality attributes（CQAs）， and calcination temperature， calcination time， spreading thickness and particle size as critical process parameters（CPPs） determined by the failure mode and effect analysis（FMEA）， the processing technology of calcined Haematitum was optimized by orthogonal test combined with analytic hierarchy process-criteria importance through intercriteria correlation（AHP-CRITIC） hybrid weighting method. The contents of heavy metals and harmful elements were determined by inductively coupled plasma mass spectrometry， and the health risk assessment was carried out by daily exposure（EXP）， target hazard quotient（THQ） and lifetime cancer risk（LCR）， and the theoretical value of the maximum limit was deduced. ResultsThe optimal processing technology for calcined Haematitum was calcination at 650 ℃， calcination time of 1 h， particle size of 0.2-0.5 cm， spreading thickness of 1 cm， and vinegar quenching for 1 time［Haematitum-vinegar（10：3）］. The contents of 5 heavy metals and harmful elements in 13 batches of calcined Haematitum were all decreased with reductions of up to 5-fold. The cumulative THQ of 2 batches of samples was>1， while the cumulative THQ of all batches of Haematitum was>1. The LCR of As in 1 batches of Haematitum was 1×10^-6-1×10^-4， and the LCR of the rest was<1×10^-6， and the LCRs of calcined Haematitum were all<1×10^-6， indicating that the carcinogenic risk of calcined Haematitum was low， but special attention should still be paid to Haematitum medicinal materials. Preliminary theoretical values of the maximum limits of Cu， As， Cd， Pb and Hg were formulated as 1 014， 25， 17， 27， 7 mg·kg^-1. ConclusionThe optimized processing technology of calcined Haematitum is stable and feasible， and the contents of heavy metals and harmful elements are reduced after processing. Preliminary theoretical values of the maximum limits of Cu， As， Cd， Pb and Hg are formulated to provide a scientific basis for the formulation of standards for the limits of harmful elements in Haematitum.

ObjectiveBased on the concept of quality by design（QbD）， the processing process of calcined Pyritum was optimized， and its X-ray diffraction（XRD） fingerprint was established. MethodsThe safety， effectiveness and quality controllability of calcined Pyritum were taken as the quality profile（QTPP）， the color， hardness， metallic luster， phase composition， the contents of heavy metals and hazardous elements were taken as the critical quality attributes（CQAs）， and the calcination temperature， calcination time， paving thickness and particle size were determined as the critical process parameters（CPPs）. Differential thermal analysis， X-ray diffraction（XRD） and inductively coupled plasma mass spectrometry（ICP-MS） were used to analyze the correlation between the calcination temperature and CQAs of calcined Pyritum. Then， based on the criteria importance through intercriteria correlation（CRITIC）-entropy weight method， the optimal processing process of calcined Pyritum was optimized by orthogonal test. Powder XRD was used to analyze the phase of calcined Pyritum samples processed according to the best process， and the mean and median maps of calcined Pyritum were established by the superposition of geometric topological figures， and similarity evaluation and cluster analysis were carried out. ResultsThe results of single factor experiments showed that the physical phase of Pyritum changed from FeS₂ to Fe₇S₈ during the process of temperature increase， the color gradually deepened from dark yellow， and the contents of heavy metals and harmful elements decreased. The optimized processing process of calcined Pyritum was as follows：calcination temperature at 750 ℃， calcination time of 2.5 h， paving thickness of 3 cm， particle size of 0.8-1.2 cm， vinegar quenching 1 time［Pyritum-vinegar（10∶3）］. After calcination， the internal structure of Pyritum was honeycomb-shaped， which was conducive to the dissolution of active ingredients. XRD fingerprints of 13 batches of calcined Pyritum characterized by 10 common peaks were established. The similarities of the relative peak intensities of the XRD fingerprints of the analyzed samples were>0.96， and it could effectively distinguish the raw products and unqualified products. ConclusionTemperature is the main factor affecting the quality of calcined Pyritum. After processing， the dissolution of the effective components in Pyritum increases， and the contents of heavy metals and harmful substances decrease， reflecting the function of processing to increase efficiency and reduce toxicity. The optimized processing process is stable and feasible， and the established XRD fingerprint can be used as one of the quality control standards of calcined Pyritum.

ObjectiveTo investigate the processing technology of calcined Haematitum based on the concept of quality by design（QbD） and to assess its health risk. MethodsTaking whole iron content， Fe²⁺ dissolution content and looseness as critical quality attributes（CQAs）， and calcination temperature， calcination time， spreading thickness and particle size as critical process parameters（CPPs） determined by the failure mode and effect analysis（FMEA）， the processing technology of calcined Haematitum was optimized by orthogonal test combined with analytic hierarchy process-criteria importance through intercriteria correlation（AHP-CRITIC） hybrid weighting method. The contents of heavy metals and harmful elements were determined by inductively coupled plasma mass spectrometry， and the health risk assessment was carried out by daily exposure（EXP）， target hazard quotient（THQ） and lifetime cancer risk（LCR）， and the theoretical value of the maximum limit was deduced. ResultsThe optimal processing technology for calcined Haematitum was calcination at 650 ℃， calcination time of 1 h， particle size of 0.2-0.5 cm， spreading thickness of 1 cm， and vinegar quenching for 1 time［Haematitum-vinegar（10：3）］. The contents of 5 heavy metals and harmful elements in 13 batches of calcined Haematitum were all decreased with reductions of up to 5-fold. The cumulative THQ of 2 batches of samples was>1， while the cumulative THQ of all batches of Haematitum was>1. The LCR of As in 1 batches of Haematitum was 1×10^-6-1×10^-4， and the LCR of the rest was<1×10^-6， and the LCRs of calcined Haematitum were all<1×10^-6， indicating that the carcinogenic risk of calcined Haematitum was low， but special attention should still be paid to Haematitum medicinal materials. Preliminary theoretical values of the maximum limits of Cu， As， Cd， Pb and Hg were formulated as 1 014， 25， 17， 27， 7 mg·kg^-1. ConclusionThe optimized processing technology of calcined Haematitum is stable and feasible， and the contents of heavy metals and harmful elements are reduced after processing. Preliminary theoretical values of the maximum limits of Cu， As， Cd， Pb and Hg are formulated to provide a scientific basis for the formulation of standards for the limits of harmful elements in Haematitum.

ObjectiveBased on the concept of quality by design（QbD）， the processing process of calcined Pyritum was optimized， and its X-ray diffraction（XRD） fingerprint was established. MethodsThe safety， effectiveness and quality controllability of calcined Pyritum were taken as the quality profile（QTPP）， the color， hardness， metallic luster， phase composition， the contents of heavy metals and hazardous elements were taken as the critical quality attributes（CQAs）， and the calcination temperature， calcination time， paving thickness and particle size were determined as the critical process parameters（CPPs）. Differential thermal analysis， X-ray diffraction（XRD） and inductively coupled plasma mass spectrometry（ICP-MS） were used to analyze the correlation between the calcination temperature and CQAs of calcined Pyritum. Then， based on the criteria importance through intercriteria correlation（CRITIC）-entropy weight method， the optimal processing process of calcined Pyritum was optimized by orthogonal test. Powder XRD was used to analyze the phase of calcined Pyritum samples processed according to the best process， and the mean and median maps of calcined Pyritum were established by the superposition of geometric topological figures， and similarity evaluation and cluster analysis were carried out. ResultsThe results of single factor experiments showed that the physical phase of Pyritum changed from FeS₂ to Fe₇S₈ during the process of temperature increase， the color gradually deepened from dark yellow， and the contents of heavy metals and harmful elements decreased. The optimized processing process of calcined Pyritum was as follows：calcination temperature at 750 ℃， calcination time of 2.5 h， paving thickness of 3 cm， particle size of 0.8-1.2 cm， vinegar quenching 1 time［Pyritum-vinegar（10∶3）］. After calcination， the internal structure of Pyritum was honeycomb-shaped， which was conducive to the dissolution of active ingredients. XRD fingerprints of 13 batches of calcined Pyritum characterized by 10 common peaks were established. The similarities of the relative peak intensities of the XRD fingerprints of the analyzed samples were>0.96， and it could effectively distinguish the raw products and unqualified products. ConclusionTemperature is the main factor affecting the quality of calcined Pyritum. After processing， the dissolution of the effective components in Pyritum increases， and the contents of heavy metals and harmful substances decrease， reflecting the function of processing to increase efficiency and reduce toxicity. The optimized processing process is stable and feasible， and the established XRD fingerprint can be used as one of the quality control standards of calcined Pyritum.

Objective To investigate the screening results and factors affecting abnormal detection rates among high-risk groups of esophageal cancer and to explore effective intervention measures. Methods We investigated and collected the information on gender, education level, age, marital status, symptoms of reflux esophagitis (heartburn, acid reflux, belching, hiccup, foreign body sensation in the pharynx, and difficulty swallowing), consumption of pickled vegetables, salt use, and esophageal cancer incidence of villagers in a natural village in Wenfeng District, Anyang City, Henan Province. Changes in reflux esophagitis symptoms in the high-incidence area of esophageal cancer before and after 16 years were observed, and the relationship of such changes with esophageal cancer was analyzed. Results In 2008, 711 cases were epidemiologically investigated, including 213 cases with one of the symptoms of reflux esophagitis such as heartburn, acid reflux, belching, hiccups, foreign body sensation in the pharynx, and difficulty swallowing (sorted in accordance with the abovementioned symptoms; if there are multiple symptoms, then the former is taken); 55 cases with at least two related symptoms, among which the most symptom was heartburn in 108 cases (15.1%); followed by acid reflux, belching, etc. In 2024, the same group of people was investigated, and eight people were missing because of relocation. A total of 703 people were successfully investigated, of which 189 cases (26.8%) had one of the symptoms of reflux esophagitis, such as heartburn (sorted in accordance with relevant symptoms, if there are multiple symptoms, then the former will be selected); 167 cases (23.7%) had at least two related symptoms, among which the most symptom was heartburn in 139 cases (19.7%); followed by acid reflux. Over 16 years, among the 703 people investigated, 45 cases had esophageal cancer and they had one or more of the abovementioned symptoms. No significant differences in the reflux esophagitis-like symptoms were found between 2008 and 2024 (P=0.26); no significant differences in the composition of reflux esophagitis-like symptoms were found between 2008 and 2024 (P=0.299). Conclusion The detection rate of reflux esophagitis-related symptoms in the population in a high-risk area of esophageal cancer has not decreased in the past 16 years, and the high-risk factors still exist. Esophageal cancer is closely related to reflux esophagitis, and clinical practice can provide early diagnosis and treatment for high-risk population.

Objective To investigate the relationship between tooth loss and the occurrence of esophageal cancer in a natural village in Wenfeng District, Anyang City, Henan Province. Methods A prospective cohort study was conducted to observe the occurrence of tooth loss and esophageal cancer among the asymptomatic residents of the natural village for 16 years from January 2008 to July 2024. Data were analyzed by chi-square test, binary logistic regression, and restricted cubic spline. Results Among the total population of 711 cases, 136 cases were lost to follow-up and 575 cases were included in the final statistics, including 45 cases with esophageal cancer. Significant statistical difference was found between esophageal cancer patients with and without tooth loss (P<0.05). Logistic regression analysis showed that tooth loss was associated with the occurrence of esophageal cancer (OR=3.977, 95%CI: 1.543-10.255). After the adjustment for confounders, tooth loss remained significantly associated with the occurrence of esophageal cancer (OR=3.038, 95%CI: 1.035-8.914). A nonlinear dose-response relationship was observed between the number of teeth lost and the incidence of esophageal cancer. When the number of teeth lost was less than 12, the risk of esophageal cancer increased with the number of teeth lost. When more than 12 teeth were lost, the risk of esophageal cancer decreased as the number of teeth lost increased. Conclusion Tooth loss is a risk factor for the occurrence of esophageal cancer in this natural village. When the number of teeth lost is less than 12, the risk of esophageal cancer increases with the number of teeth lost.