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Xiaoqiang Yu, Lei He, Yuting Hu, Jiajie Li, Xiao Liu, Yuhan Wang, Chunji Li, Munan Yang, and Zhenchen Zhong
- Journal of Magnetics. 2022-06 27(2):155-163
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Jiajie Li, Jingda Huang, Yanqing Lv, and Huifan Ji
- Frontiers in Nutrition, Vol 10 (2023)
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B vitamins, postmenopausal women, NAFLD, liver fibrosis, National Health and Nutrition Examination Survey, Nutrition. Foods and food supply, and TX341-641
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BackgroundNon-alcoholic fatty liver disease (NAFLD) is increasingly common globally, particularly among postmenopausal women. Diet plays a fundamental role in the treatment of NAFLD. However, clinical research on the dietary intakes of B vitamins, specifically in postmenopausal women, is scant. Hence, it is imperative to study the impact of B vitamin dietary intake in postmenopausal women.MethodsThis study utilized National Health and Nutrition Examination Survey (NHANES) data for 668 postmenopausal women. Logistic regression analysis was conducted to investigate the association of the intakes of B vitamins with hepatic steatosis and liver fibrosis prevalence. The analysis accounted for various covariates and employed restricted cubic spline analysis to examine potential nonlinear relationships. Additionally, interactions among age, diabetes, and B-vitamin intakes, as well as the interaction between folate and vitamin B12 intake, were explored.ResultsHigher intakes of folate [0.30 (0.10–0.88)], choline [0.26 (0.07–0.95)], vitamin B1, and vitamin B2 were associated with a reduced risk of hepatic steatosis in postmenopausal women. The associations of niacin (P-nonlinear = 0.0003), vitamin B1 (P-nonlinear = 0.036), and vitamin B2 (P-nonlinear
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3. Mechanism of stress-loaded rockburst in fully mechanized top-coal caving stope with deep overburden [2023]
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Xiang ZHANG, Sitao ZHU, Fuxing JIANG, Xiufeng ZHANG, Shidong LI, Chao WANG, Jinhai LIU, Yang CHEN, Tao ZHOU, Jiajie LI, and Chun ZHU
- Meitan xuebao, Vol 48, Iss 5, Pp 2092-2105 (2023)
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rockburst, deep topsoil, stress-loaded, overburden structure, collapse arch, pressure arch, Geology, QE1-996.5, Mining engineering. Metallurgy, and TN1-997
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The stress-loaded rockburst is a unique type of rockburst that occurs in some fully mechanized top-coal caving stopes with deep thick overburden, its occurrence mechanism is still unclear, leading to the failure to effective prevention and even serious accidents when the coal mine is faced with this type of rock burst. This study focuses on the stress-loaded rockburst that occurred in the 3304 fully mechanized top-coal caving face of the Zhaolou Coal Mine, Juye Coalfield, which lasted for 38 days and had a large range of impact warning (100 m ahead). Through material tests, theoretical analysis, numerical simulations, and field measurements, the study investigates the occurrence mechanism of stress-loaded rockburst in the fully mechanized top-coal caving stopes with deep thick overburden. The study proposes the spatial movement characteristics of overburden in the fully mechanized top-coal caving stopes with deep thick overburden through simulation tests and theoretical analysis. The contour expressions of collapse arch and pressure arch of thick overburden are derived based on the arching property and time-dependent loading property of thick overburden when the bearing bedrock is first broken. An estimation model for the transfer stress of overlying strata along the strike of the fully mechanized top-coal caving stopes with deep thick overburden is established. The mechanism of stress-loaded rockburst in the fully mechanized top-coal caving stopes with deep thick overburden is revealed through the study. When the bearing bedrock reaches the hanging limit and breaks and rotates, the thick overburden moves and sinks to form an earth pressure arch structure. The weight of the overlying thick overburden is transferred to the coal seam through the arch foot, resulting in a large range of coal seam stress in front of the coal wall that continues to rise in a short time, which can induce stress-loaded rockburst. The numerical simulation results show that after the bearing bedrock of fully mechanized top-coal caving stopes with deep thick overburden breaks, the thick overburden presents the movement characteristics of progressive breaking and collapse from the bottom to the top. The stope forms two pressure arches with the rock and soil contact surface as the boundary. The weight of the overburden pressure arches causes the high concentration of stress in the large range of coal seams in front of the coal wall. The field measurement shows that the dynamic load release level of the stope is low after the stress loading effect occurs, and the micro-earthquake concentration zone is fixed. The formation of the earth pressure arch will limit the rapid subsidence of the topsoil. The working face is located in the fulcrum area of the earth pressure arch for mining. When the working face pushes over the fulcrum loading area, the destruction of the earth pressure arch will lead to the overall large subsidence of the stope surface. The study proposes a prevention and control plan for the stress-loaded rockburst in the fully mechanized top-coal caving stopes with deep thick overburden, including underground ground joint monitoring and early warning, high-strength borehole weakening of surrounding rock, reinforcement of support system in the exposed area, and “monitoring and pressure relief” critical pushing speed control.
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Gaoang Wang, Sitao Zhu, Xiufeng Zhang, Yingyuan Wen, Zhijie Zhu, Quanjie Zhu, Liangfu Xie, Jiajie Li, Yi Tan, Tao Yang, Yuanyuan Pu, and Chun Zhu
- Frontiers in Earth Science, Vol 11 (2023)
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thick and hard key stratum, overlying strata spatial structure, prediction of mininginduced seismicity, vibration damage, the temporal and spatial distribution law, and Science
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Thick and hard key stratum working faces are characterized by frequent mine tremors and significant ground tremors during mining which seriously threaten the safety production of the mine. With working face (4-5) 06 of Xinjiang Liuhuanggou Coal Mine as the engineering background, using field investigation, microseismic monitoring, and theoretical analysis, a mining-induced seismicity prediction method and damage assessment of surface buildings for thick and hard key stratum working faces is proposed, which is based on the evolution characteristics of overlying strata spatial structure and the motion state of the key stratum. The results of the study are as follows: 1) The movement law of overlying strata is the basis of mining-induced seismicity prediction for working faces. The magnitude of the risk of mining-induced seismicity occurrence is mainly related to the boundary conditions of the working face, the thickness of the key stratum, the distance from the coal seam to the key stratum, the height of the overlying strata spatial structure, and the fracture step of the key stratum. 2) The mining-induced seismicity energy contains the original accumulation elastic energy of the key stratum, the transfer elastic energy of low rock strata, and the accumulation elastic energy of gravity work. Based on this, a mechanical model of surface building damage induced by the release of mining-induced seismicity energy was established. A ground vibration damage boundary and vibration induction boundary under the action of strong mining-induced seismicity were proposed, and the service life of buildings when they reach the critical damage value under the action of frequent mining-induced seismicity was obtained. 3) The temporal and spatial distribution law of mining-induced seismicity activities in thick and hard key stratum working faces was revealed. According to the results of micro-seismic monitoring, the “zonality” characteristics of the time series and the “transition” law of spatial distribution of mining-induced seismicity verified the reliability of the mining-induced seismicity prediction method. The research results provide a theoretical basis for predicting mining-induced seismicity and assessing the risk of induced disasters during the mining process of thick and hard key stratum working faces, and can provide technical support for mining-induced seismicity prevention and control and safety production in mines with similar conditions.
- Full text View record in DOAJ
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Jiajie Li, Yan Wang, Riyun Yang, Wenjun Ma, JunGuo Yan, Yi Li, Gang Chen, and Jingying Pan
- Frontiers in Aging Neuroscience, Vol 15 (2023)
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Huntington disease, pain, prevalence, neuropathology, pain symptoms, Neurosciences. Biological psychiatry. Neuropsychiatry, and RC321-571
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Pain is common and frequent in many neurodegenerative diseases, although it has not received much attention. In Huntington’s disease (HD), pain is often ignored and under-researched because attention is more focused on motor and cognitive decline than psychiatric symptoms. In HD progression, pain symptoms are complex and involved in multiple etiologies, particularly mental issues such as apathy, anxiety and irritability. Because of psychiatric issues, HD patients rarely complain of pain, although their bodies show severe pain symptoms, ultimately resulting in insufficient awareness and lack of research. In HD, few studies have focused on pain and pain-related features. A detailed and systemic pain history is crucial to assess and explore pain pathophysiology in HD. This review provides an overview concentrating on pain-related factors in HD, including neuropathology, frequency, features, affecting factors and mechanisms. More attention and studies are still needed in this interesting field in the future.
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Hengrui Liu, Zhenghong Tian, Yuanshan Ma, Junzheng Xiang, Xiao Sun, JiaJie Li, and Xian Zuo
- Case Studies in Construction Materials, Vol 18, Iss , Pp e02091- (2023)
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Attapulgite, Mechanical strength, Pore structure, Microstructure, Mechanism of hydration, Materials of engineering and construction. Mechanics of materials, and TA401-492
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In this paper, the effects of attapulgite processed by two different methods, burning and grinding attapulgite (BGA) and grinding and burning attapulgite (GBA), on the macroscopic mechanical properties and microscopic hydration mechanism of cement paste were systematically studied. The application potential of these two materials in the field of cement-based materials was analyzed and evaluated. The results indicated that both BGA and GBA inhibited the hydration of cement to varying degrees at 7th day of age. Due to the competitive adsorption of water by the nanorod crystal structure of BGA and GBA, the amount of water used for cement hydration decreased, thus reducing the hydration degree of cement. The decrease of hydration product content increased the porosity and leaded to the decrease of mechanical strength. At the age of 28th days, due to the slow-release effect of the nanorod crystal structure and the pozzolanic effect, the macroscopic mechanical strength of the admixture ratio except for 20 % BGA all exceeded that of control paste. The mass generation of hydration products of the paste formed a dense micro structure and thus reduced the porosity. The structure and morphology of Calcium silicate hydrate (CSH) formed by BGA and GBA were distinctive by SEM-EDS at 28th days, because Ca/Si in CSH decreased to different degrees. In general, the performance of GBA on cement hydration kinetics and macroscopic mechanical strength was better than that of BGA at 7th and 28th day, and 20 % GBA was the optimal ratio of all mixture ratios.
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Baoyu ZHU, Dan ZHANG, Zhanhui LIANG, Yang GAO, Hongyan LI, Jiajie LI, and Qingsong CHEN
- 环境与职业医学, Vol 40, Iss 1, Pp 55-61 (2023)
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power supply enterprises, operation and maintenance worker, long working hours, work-related musculoskeletal disorders, prevalence, Medicine (General), R5-920, Toxicology. Poisons, and RA1190-1270
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BackgroundLong working hours is harmful to the physical and mental health of occupational groups, and should receive active attention. ObjectiveTo 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. MethodsFrom 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. ResultsThe 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 P49 h per week was higher (OR=1.406, 95%CI: 1.011-1.955). ConclusionLong working hours is prominent among operation and maintenance workers of power supply enterprises, and increases the risk of reporting WMSDs.
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Dan ZHANG, Baoyu ZHU, Zhanhui LIANG, Tao CHEN, Hongyan LI, Yang GAO, Jiajie LI, and Qingsong CHEN
- 环境与职业医学, Vol 40, Iss 1, Pp 21-26 (2023)
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power supply enterprise, climbing task, work-related musculoskeletal disorders, influencing factor, relationship, Medicine (General), R5-920, Toxicology. Poisons, and RA1190-1270
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BackgroundOperation 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. ObjectiveTo understand the prevalence and influencing factors of WMSDs among climbing task-involved workers in power supply enterprises. MethodsUsing 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. ResultsA 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. ConclusionThe 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.
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Zhanhui LIANG, Jiajie LI, Dan ZHANG, Baoyu ZHU, Hongyan LI, Yang GAO, and Qingsong CHEN
- 环境与职业医学, Vol 40, Iss 1, Pp 62-67 (2023)
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operation inspection personnel, climbing operation, electromyography signal, muscle fatigue, ergonomics, Medicine (General), R5-920, Toxicology. Poisons, and RA1190-1270
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BackgroundClimbing 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. ObjectiveTo 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. MethodsTen 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. ResultsThe 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. ConclusionThe 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).
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Guanlin LI, Xin SUN, Meibian ZHANG, Huadong ZHANG, Ruijie LING, Yimin LIU, Gang LI, Nengzhou CHEN, Zaoliang REN, Yan YIN, Hua SHAO, Hengdong ZHANG, Jiajie LI, Bing QIU, Dayu WANG, Qiang ZENG, Zhanhui LIANG, Rugang WANG, Jianchao CHEN, Danying ZHANG, Liangying MEI, Yongquan LIU, Jixiang LIU, Chengyun ZHANG, Tianlai LI, Ning JIA, Junyi WANG, Zhongxu WANG, and Qingsong CHEN
- 环境与职业医学, Vol 40, Iss 1, Pp 49-54 (2023)
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occupational population, wrist joint posture, wrist pain, Medicine (General), R5-920, Toxicology. Poisons, and RA1190-1270
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BackgroundProlonged awkward postures during occupational activities can lead to excessive musculoskeletal load on the wrist of workers and symptoms such as wrist pain or discomfort.ObjectiveTo survey the prevalence of wrist pain among workers in 10 key industries and analyze its correlation with wrist working postures.MethodsBy using stratified cluster sampling method, workers from 10 key industries, such as footwear manufacturing industry, shipbuilding manufacturing industry, and automobile manufacturing industry, were selected from seven regions in North China, East China, Central China, South China, Southwest China, Northwest China, and Northeast China. The demographic information, wrist working postures, pain in wrist of the workers were collected through a cross-sectional survey. Pearson χ2 test was used to compare prevalence by selected factors, trend χ2 test for between group comparison, and unconditional logistic regression models for the association of wrist working postures with wrist pain.ResultsThere were 64052 workers enrolled in this survey, and 56286 provided valid questionnaires (the effective rate was 87.8%). According to the survey, the prevalence of wrist pain was 23.3% (13112/56286), and the industries with higher prevalences were footwear manufacturing (27.1%, 1927/7106), automobile manufacturing (24.9%, 5378/21560), and shipbuilding and related equipment manufacturing (24.4%, 850/3488) industries. Finger pinching (OR=2.09, 95%CI: 1.95-2.24), frequent wrist bending (OR=2.03, 95%CI: 1.92-2.15), fixed wrist bending (OR=1.77, 95%CI: 1.69-1.85), wrist on hard edge (OR=1.34, 95%CI: 1.28-1.40), and arms over shoulders (OR=1.11, 95%CI: 1.05-1.17) increased the risk of reporting wrist pain.ConclusionAwkward postures are related to wrist pain among workers in selected 10 key industries. The related factors are wrist on hard edge, frequent wrist bending, finger pinching, fixed wrist bending, and arms over shoulders.
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11. Neck and shoulder pain among operation and maintenance workers of selected power supply enterprises [2023]
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Dan ZHANG, Baoyu ZHU, Jiajie LI, Hongyan LI, Yang GAO, Zhanhui LIANG, and Qingsong CHEN
- 环境与职业医学, Vol 40, Iss 1, Pp 34-42 (2023)
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power supply enterprise, operation and maintenance worker, work-related musculoskeletal disorder, neck, shoulder, influencing factor, Medicine (General), R5-920, Toxicology. Poisons, and RA1190-1270
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BackgroundPower 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. ObjectiveTo 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. MethodsFrom 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. ResultsA 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. ConclusionThe 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.
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Qian Cao, Yueyang Zhai, Binyue Huang, Renjie Li, and Jiajie Li
- Frontiers in Physics, Vol 11 (2023)
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spin exchange relaxation free atomic magnetometer, pumping effect, probe laser system, degree of polarization, quarter wave plate, Physics, and QC1-999
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Introduction: A spin exchange relaxation free atomic magnetometer, as an ultra-highly sensitive magnetic field sensor, is limited by the performance of the probe laser system. The probe laser pumping effect (PLPE) hinders the increase in the performance of probe laser system.Methods: This study investigated the PLPE and proposed a method for suppressing the same. Through changes to the angle of a quarter wave plate and the addition of a triangular modulated magnetic field to the alkali atoms, the suppression point was determined.Results and discussion: Further, related parameters were measured for different degree of polarizations of the probe laser, which confirmed that the influence of PLPE on the magnetic field was the least at the suppressed point.
- Full text View record in DOAJ
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Jiajie Li, Lin Liu, Junmin Xing, Dianhui Chen, Chao Fang, Feng Mo, Yumei Gong, Zhengrong Tan, Guikuan Liang, Wei Xiao, Shanni Tang, Haixia Wei, Shan Zhao, Hongyan Xie, Xingfei Pan, Xiaomao Yin, and Jun Huang
- Frontiers in Immunology, Vol 14 (2023)
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malaria, TLR7, extramedullary splenic erythropoiesis, IFN-γ, macrophages, iron metabolism, Immunologic diseases. Allergy, and RC581-607
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Splenomegaly is a prominent clinical manifestation of malaria and the causes remain incompletely clear. Anemia is induced in malaria and extramedullary splenic erythropoiesis is compensation for the loss of erythrocytes. However, the regulation of extramedullary splenic erythropoiesis in malaria is unknown. An inflammatory response could facilitate extramedullary splenic erythropoiesis in the settings of infection and inflammation. Here, when mice were infected with rodent parasites, Plasmodium yoelii NSM, TLR7 expression in splenocytes was increased. To explore the roles of TLR7 in splenic erythropoiesis, we infected wild-type and TLR7-/- C57BL/6 mice with P. yoelii NSM and found that the development of splenic erythroid progenitor cells was impeded in TLR7-/- mice. Contrarily, the treatment of the TLR7 agonist, R848, promoted extramedullary splenic erythropoiesis in wild-type infected mice, which highlights the implication of TLR7 on splenic erythropoiesis. Then, we found that TLR7 promoted the production of IFN-γ that could enhance phagocytosis of infected erythrocytes by RAW264.7. After phagocytosis of infected erythrocytes, the iron metabolism of RAW264.7 was upregulated, evidenced by higher iron content and expression of Hmox1 and Slc40a1. Additionally, the neutralization of IFN-γ impeded the extramedullary splenic erythropoiesis modestly and reduced the iron accumulation in the spleen of infected mice. In conclusion, TLR7 promoted extramedullary splenic erythropoiesis in P. yoelii NSM-infected mice. TLR7 enhanced the production of IFN-γ, and IFN-γ promoted phagocytosis of infected erythrocytes and the iron metabolism of macrophages in vitro, which may be related to the regulation of extramedullary splenic erythropoiesis by TLR7.
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Huimin HUANG, Yan BAI, Ziyu CHEN, Zhishan LIANG, Lyurong LI, Hansheng LIN, Jiajie LI, Yuan WEI, Hongyu YANG, and Qingsong CHEN
- 环境与职业医学, Vol 39, Iss 11, Pp 1198-1203 (2022)
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hand-transmitted vibration, hand-arm vibration disease, prevalence rate, cumulative vibration exposure level, Medicine (General), R5-920, Toxicology. Poisons, and RA1190-1270
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BackgroundHand-arm vibration disease is harmful to human body, but there are no effective diagnosis and treatment so far, and current occupational exposure limits underestimate the health damage caused by high-frequency vibration exposure. ObjectiveTo evaluate and compare the damage to workers' peripheral circulation and peripheral nerve caused by different frequencies of vibration operation. MethodsDrilling workers (n=187) from a mining company in Shandong Province and golf club head grinding workers (n=228) from a sports equipment factory in Guangdong Province were selected as study subjects. Hand symptoms were investigated. SV106 vibration meter was used to measure the target operation-associated vibration frequency spectrum. The 8 h energy-equivalent frequency weighted acceleration, cumulative vibration exposure level (CVEL), and the working age related to causing white finger in 10% of an exposed group were calculated.ResultThe study subjects were all male. More grinding workers reported hand symptoms than the drilling workers, e.g. peripheral circulation injury (52.6% vs 19.3%), peripheral nerve injury (71.5% vs 23.0%), hand stiffness (64.0% vs 7.0%), and deformed fingers (69.7% vs 4.3%) (all P
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Xiuwen HU, Ziyu CHEN, Jiajie LI, Yuan WEI, Yun XIA, Qingsong CHEN, and Hongyu YANG
- 环境与职业医学, Vol 39, Iss 11, Pp 1204-1208 (2022)
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hand-arm vibration disease, leukotriene b4, interleukin-1β, vascular endothelial growth factor, 5-hydroxy tryptamine, receiver operator characteristic curve, Medicine (General), R5-920, Toxicology. Poisons, and RA1190-1270
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BackgroundHand-arm vibration disease (HAVD) is a chronic progressive disease caused by long-term exposure to hand-transmitted vibration, but the mechanism by which vibration affects peripheral vascular function of fingers is not completely clear. ObjectiveTo study the association between vasoactive factors and HAVD, and to screen specific indicators for its early diagnosis and prevention. MethodsJudgmental sampling method was used to select workers with (HAVD group) and without HAVD (vibration contact group), and non-hand-transmitted vibration operation workers (control group), with 60 workers in each group. The levels of leukotriene B4 (LTB4), vascular endothelial growth factor (VEGF), 5-hydroxy tryptamine (5-HT), interleukin-1β (IL-1β), and calcitonin gene-related peptide (CGRP) in plasma of the three groups were measured by enzyme-linked immunosorbent assay. The association between vasoactive factors and HAVD was analyzed using logistic regression, and the diagnostic HAVD indicators were screened by receiver operator characteristic (ROC) curve of a multivariate model indicator \begin{document}$ \widehat{Y} $\end{document}. ResultsThe hand symptom rates of the HAVD group, the vibration contact group, and the control group were 26.7%, 66.7%, and 96.7% respectively, with a significant difference (P0.05). The logistic regression results showed that higher levels of LTB4 (OR=1.048, 95%CI: 1.022-1.076), 5-HT (OR=1.011, 95%CI: 1.004-1.018), IL-1β (OR=1.148, 95%CI: 1.071-1.230), and CGRP (OR=1.055, 95%CI: 1.008-1.104) were associated with a higher risk of HAVD (P IL-1β (0.907) > LTB4 (0.876) > 5-HT (0.858) > CGRP (0.836). ConclusionThe expression levels of LTB4, 5-HT, IL-1β, and CGRP are altered with occupational exposure in hand-transmitted vibration operations and may be associated with HAVD; VEGF is not found to be associated with HAVD. The accuracy of early screening for HAVD can be improved by combining the monitoring of various biochemical indicators.
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16. Mineral Carbonation Potential (MCP) of Mine Waste Material: Derivation of an MCP Parameter [2023]
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Anthony Jacobs, Michael Hitch, Sara Mosallanejad, Tejas Bhatelia, Jiajie Li, and Faezeh Farhang
- Minerals, Vol 13, Iss 9, p 1129 (2023)
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mineral carbonation, ultramafic rocks, mine waste material, carbonation potential, CCUS tools, Mineralogy, and QE351-399.2
- Abstract
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The heterogenous mineralogy of ultramafic deposits hosting mining operations makes it challenging to accurately determine the waste rock’s mineral carbonation potential (MCP). Additionally, the significantly higher carbonation capabilities of olivine than serpentine add to the difficulty. To address this issue, in this work, a new and unique tool called the MCP calculator was developed as a Microsoft ExcelTM spreadsheet to accurately determine the amount of anthropogenic CO2 that a given rock mass can sequester through mineral carbonation. The program estimates the modal mineral abundance of ultramafic rocks to aid in MCP estimation. This tool is designed to be cost-effective and tailored for use by the mining industry, utilising abundant lithogeochemical data to evaluate their deposit as a potential substrate for industrial mineral carbonation operations. The paper introduces the MCP calculator, outlines a framework for developing the MCP parameter, and presents an example of its application. The calculator is specific to the mineral assemblage investigated at the Turnagain ultramafic complex in northern British Columbia but can be adjusted to study comparable deposits. The paper acknowledges that using waste rock in a mineral carbonation operation requires economic and practical decisions beyond the scope of the research.
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Amer Baras, Jiajie Li, Wen Ni, Zahid Hussain, and Michael Hitch
- Processes, Vol 11, Iss 9, p 2590 (2023)
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steel slag, accelerated carbonation, carbonation curing, steel slag carbonations’ influencing factors, Chemical technology, TP1-1185, Chemistry, and QD1-999
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Steel slag is a solid waste product generated during the carbonation stage of steelmaking. It has high levels of heavy metals and substantial amounts of free calcium and magnesium oxide, making it unsuitable for use as a cement material. Furthermore, the disposal of steel slag in landfills requires many resources and can seriously contaminate the surrounding environment. One method of reducing its negative environmental impact is carbonation, which involves reacting steel slag with carbon dioxide to form stable minerals. However, many parameters influence the carbonation efficiency of steelmaking slag, including temperature, time, particle size, pressure, CO2 concentration, liquid-to-solid ratio, moisture content, humidity, additives, etc. To this end, this paper comprehensively reviews the most important steel slag carbonation-influencing factors. Moreover, it compares the characteristics from two perspectives based on their causes and effects on carbonation. Finally, this article reviews earlier studies to identify the factors that affect steel slag carbonation and the potential of carbonated steel slag as a sustainable construction material. Based on previous research, it systematically examines all the elements for future work that need to be improved.
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Xin Qin, Lirong Xiao, Ni Li, Chen Hou, Wenman Li, Jiajie Li, Naihong Yan, and Yunfeng Lin
- Bioactive Materials, Vol 14, Iss , Pp 134-144 (2022)
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Choroidal neovascularization, Tetrahedral framework nucleic acid, Macrophages, MicroRNA-155, Immunity therapy, Materials of engineering and construction. Mechanics of materials, TA401-492, Biology (General), and QH301-705.5
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Choroidal neovascularization (CNV) is a common pathological feature of various eye diseases and an important cause of visual impairment in middle-aged and elderly patients. In previous studies, tetrahedral framework nucleic acids (tFNAs) showed good carrier performance. In this experiment, we developed microRNA-155-equipped tFNAs (T-155) and explored its biological effects on CNV. Based on the results of in-vitro experiments, T-155 could regulate macrophages into the antiangiogenic M1 type. Then, we injected T-155 into the vitreous of laser-induced CNV model mice and found that T-155 significantly reduced the size and area of CNV, inhibited blood vessel leakage. In summary, we prove that T-155 could regulate the inflammatory process of CNV by polarizing macrophages, thereby improving the symptoms of CNV. Thus, T-155 might become a new DNA-based drug with great potential for treating CNV.
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Shan Wu, Lvrong Li, Guiyuan Ji, Xiaohui Xing, Jiajie Li, Anping Ma, Yuan Wei, Dongwei Zhao, Huimin Huang, Wenjun Ma, Banghua Wu, Ming Dong, Tao Liu, and Qingsong Chen
- Frontiers in Public Health, Vol 11 (2023)
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multiple metals, hypertension, blood pressure, obesity, interaction, BKMR analysis, Public aspects of medicine, and RA1-1270
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BackgroundEnvironmental exposure to multiple metals have been inconsistently associated with hypertension. Obesity is an important independent risk factor for hypertension, and few studies have assessed the interaction between obesity and metals in this context. We aimed to clarify their association and interaction.MethodsThis cross-sectional study included 3,063 adults from 11 districts or counties, Guangdong. We measured the whole blood levels of 13 metals and used multipollutant-based statistical methods to analyze the association of metals with hypertension. The interaction between metals and obesity on hypertension was assessed on additive and multiplicative scales.ResultsFour metals (manganese, arsenic, cadmium, and lead) were significantly associated with hypertension risk, five metals (manganese, zinc, arsenic, cadmium, and lead) were related to elevated SBP levels, five metals (manganese, zinc, selenium, cadmium, and lead) were associated with elevated DBP levels in single-metal model. Manganese remained significantly related to hypertension risk [odds ratio, 1.35 (1.02–1.78)] after adjusting for these four metals. Significant positive dose-response relationships between manganese, arsenic, cadmium, lead and hypertension risk were observed (P for overall < 0.001, P for non-linearity > 0.05). Compared with those in the lowest quartile, participants in the highest manganese quartile had a 2.83 mmHg (95% Cl: 0.71–4.96) (PFDR = 0.040) higher level of SBP. Individuals in the highest quartiles of zinc and lead had a 1.45 mmHg (0.10–2.81) (PFDR = 0.033) and 2.06 mmHg (0.59–3.53) (PFDR = 0.020) higher level of DBP, respectively. The negative interactions between cadmium, lead and obesity influences hypertension risk. BKMR analysis showed a significant joint effect of manganese, arsenic, cadmium and lead on hypertension when the concentrations of four metals were at or above their 55th percentile compared to their median values.ConclusionsThe combined effect of four metals (manganese, arsenic, cadmium and lead) were associated with the prevalence of hypertension. Potential interaction effects of cadmium, lead and obesity on hypertension risk may exist. Further cohort studies in larger population are needed to clarify these findings.
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Zhuotong Bai, Hui Wang, Lin Yang, Jiajie Li, and Huapu Lu
- Journal of Advanced Transportation, Vol 2023 (2023)
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Transportation engineering, TA1001-1280, Transportation and communications, and HE1-9990
- Abstract
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Since unexpected event occurrences are inevitable, an efficient and effective rescheduling approach is critical in freight railway day-to-day operations. Represented by the minimal-delay objectives, the most commonly used efficiency-oriented approach ignores the role of train priority and poses equity problems in rescheduling. For equity, different train priority also reflects the preference in deciding train orders; i.e., the high-priority train is likely to be favorable. However, a conflict may be laid between reducing delays and emphasizing train priority. Hence, it is critical to decide the criteria in train order for freight railway, especially with heterogeneous priority in a competitive resource. To make a tradeoff between equity and efficiency, this paper makes train priority evolutionary and proposed the dynamic train priority considering delay time and static priority. We formulate an optimization model based on the rescheduling strategies such as retime, reorder, and retrack in a complex railway network containing single-track, double-track, and quadruple-track sections. An integrated two-dimension genetic algorithm (ITGA) approach is developed to reobtain an optimized timetable of sufficient quality while meeting the time requirements for real-time rescheduling. In the experiment, the effectiveness of the ITGA approach was employed in a simple case and a real-world case in the Netherlands freight railway. The result shows that there is a synergy between delay time and train priority, where the threshold to upgrade the evolutionary train priority plays an important role. The proposed approach is compared with the benchmark solution first-in-first-out (FIFO) approach in a real-world case to verify the performance and efficiency. Our work extends the rescheduling approach considering both equity and efficiency and provides auxiliary operation support for the dispatcher’s operation rescheduling.
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