BACKGROUND:Rheumatoid arthritis is an inflammatory disease.Many studies have shown that wogonin has a good anti-inflammatory effect on rheumatoid arthritis,but its exact efficacy and specific mechanism of action remain to be clarified. OBJECTIVE:To investigate the mechanism of wogonin ameliorating joint inflammation by regulating endoplasmic reticulum stress pathway in rats with collagen-induced arthritis. METHODS:(1)At the animal level:Female Wistar rats were divided into healthy control group,arthritis model group and wogonin treatment group.Rat models of arthritis in the latter two groups were established by subcutaneous injection of bovine type Ⅱ collagen and adjuvant.In the wogonin group,wogonin was given by gavage for 28 consecutive days after modeling.During this period,the rats in each group were weighed,and arthritis score and ankle swelling were measured every 7 days.After the experiment,the pathological changes of the joint were observed,the mRNA and protein levels of endoplasmic reticulum stress pathway GRP78 and CHOP were detected by qRT-PCR,western blot,and immunohistochemistry.(2)At the cellular level,cell counting kit-8 was used to detect the cytotoxic effect of wogonin on fibroblast-like synoviocytes from rats with collagen-induced arthritis.The fibroblast-like synoviocytes induced by thapsigargin were treated with different concentrations of wogonin.The levels of interleukin-1β and tumor necrosis factor-α in the cell supernatant were detected by ELISA,and the intracellular reactive oxygen species in each group were determined by DCFH-DA probe method.The mRNA and protein levels of GRP78,IRE1α,XBP1s and CHOP were detected by qRT-PCR and western blot,respectively. RESULTS AND CONCLUSION:Compared with the healthy control group,arthritis index score and ankle swelling degree in the arthritis model group were increased(P<0.01),synovial hyperplasia,inflammatory cell infiltration,cartilage destruction and bone erosion were observed in pathological sections,and the mRNA and protein expressions of GRP78 and CHOP in the ankle were significantly increased(P<0.01),which were mainly located in synovial tissue and articular surface.Compared with the arthritis model group,the arthritis index score and ankle swelling degree in the wogonin treatment group were decreased(P<0.05),synovial hyperplasia and the number of inflammatory cells were decreased,cartilage destruction and bone erosion were alleviated,the mRNA and protein expression levels of GRP78 and CHOP in the ankle were decreased(P<0.05),particularly in synovial tissue and on the articular surface.There was no significant difference in body mass among the three groups(P>0.05).In the cell experiment,200 μmol/L wogonin significantly reduced the survival rate of fibroblast-like synoviocytes(P<0.01).Compared with the blank control group,the levels of interleukin-1β,tumor necrosis factor-α,content of reactive oxygen species,and mRNA and protein expression of GRP78,IRE1α,XBP1s,and CHOP in the thapsigargin group were significantly increased(P<0.05);compared with the thapsigargin group,50 and 100 μmol/L wogonin significantly reduced the levels of interleukin-1β and tumor necrosis factor-α in the cell supernatant(P<0.05,P<0.01),and 100 μmol/L wogonin significantly reduced the content of reactive oxygen species(P<0.01)and down-regulated the mRNA and protein expression levels of GRP78,IRE1α,XBP1s and CHOP(all P<0.05).These results suggest that wogonin can effectively alleviate joint inflammatory responses in rats with collagen-induced arthritis,and the endoplasmic reticulum stress pathway may be the key target of its intervention.

BACKGROUND:Troxerutin has been found to have a significant ameliorative effect on brain disorders,but there are fewer studies on the effects of troxerutin on the treatment of cerebral infarction and on neuronal cells. OBJECTIVE:To investigate the mechanism by which troxerutin regulates nuclear factor-κB signaling pathway to reduce brain injury and neuronal apoptosis in cerebral infarction rats. METHODS:Fifty clean grade rats were randomized into healthy group,model group,and troxerutin+nuclear factor-κB agonist group,troxerutin group,and nuclear factor-κB inhibitor group.Except for the healthy group,all other groups were used to establish a rat model of cerebral infarction by arterial ligation.The healthy and model groups were treated once a day with an equal amount of physiological saline by gavage.The troxerutin+nuclear factor-κB agonist group was intervened with 72 mg/kg troxerutin by gavage+20 mg/kg RANK intraperitoneally.The troxerutin group was treated with 72 mg/kg troxerutin by gavage.The nuclear factor κB inhibitor group was intervened intraperitoneally with 120 mg/kg nuclear factor κB inhibitor pyrrolidine disulfiram.Administration in each group was given once a day for 30 continuous days.Zea-longa was used to detect neurological damage in rats,hematoxylin-eosin staining was used to observe pathological changes,TUNEL was used to detect neuronal apoptosis,and immunoblotting and PCR were used to detect the expression of nuclear factor-κB p65 and nuclear factor-κB p50 at protein and mRNA levels,respectively. RESULTS AND CONCLUSION:Compared with the healthy group,the neurological function score,neuronal apoptosis rate,nuclear factor-κB p65,nuclear factor-κB p50 mRNA and protein expression levels were elevated in the model group(P＜0.05).Compared with the model group,the neurological function score,neuronal apoptosis rate,nuclear factor-κB p65 and nuclear factor-κB p50 mRNA and protein expression levels were decreased in the troxerutin+nuclear factor-κB agonist group(P＜0.05).Compared with the troxerutin+nuclear factor-κB agonist group,the neurological function score,neuronal apoptosis rate,nuclear factor-κB p65 and nuclear factor-κB p50 mRNA and protein expression levels were reduced in the troxerutin group and nuclear factor-κB inhibitor group(P＜0.05).In addition,there was no difference between the troxerutin group and the nuclear factor-κB inhibitor group(P＞0.05).In the model group,there was a large number of cytoplasmic vacuolation,obvious edema and necrosis,and a large number of inflammatory cell infiltrations.In the troxerutin+nuclear factor-κB agonist,the swelling of brain tissue was reduced,and reticulate structures and condensed cells were reduced,still with some edema.In the troxerutin group and nuclear factor-κB inhibitor group,brain tissue swelling,neuronal edema degeneration,cytoplasmic vacuolation and neuronal nucleus consolidation were reduced,and the inflammatory cell infiltration was significantly decreased.To conclude,troxrutin can reduce the expression of neurological impairment,inhibit neuronal apoptosis and improve the pathological injury of brain tissue in rats with cerebral infarction,and its mechanism of action may be related to the modulation of nuclear factor-κB expression and related signaling pathways.

BACKGROUND:The repair process of myocardial injury involves complex cellular and molecular mechanisms,especially mitochondrial calcium homeostasis,macrophage autophagy and pyroptosis pathways.Traditional Chinese medicine(TCM)has shown significant clinical efficacy in improving myocardial injury,but its mechanism of action needs to be thoroughly investigated. OBJECTIVE:To investigate the role of mitochondrial calcium homeostasis-mediated macrophage autophagy and pyroptosis pathways in myocardial injury,and to summarize the progress of TCM in this field. METHODS:A computerized search was performed for relevant literature from the database inception to March 2024 in the Web of Science,PubMed and CNKI.The search terms were"mitochondrial calcium homeostasis,macrophage autophagy,macrophage pyroptosis,traditional Chinese medicine,myocardial injury,myocardial injury reperfusion"in Chinese and English.Through literature review,we analyzed the relationship between mitochondrial calcium homeostasis and macrophage autophagy and pyroptosis,explored the mechanism of their roles in myocardial injury,and summarized the pathways of multi-targeted,multi-pathway effects of TCM. RESULTS AND CONCLUSION:The maintenance of mitochondrial calcium homeostasis has been found to be closely related to the normal function of cardiomyocytes.Macrophages can participate in the repair process of myocardial injury through autophagy and pyroptosis pathways.Autophagy contributes to cell clearance and regulation of inflammatory response,while pyroptosis affects myocardial repair by releasing inflammatory factors.TCM regulates mitochondrial calcium homeostasis and macrophage function through multiple mechanisms.For example,astragalosid regulates calcium homeostasis by lowering mitochondrial membrane potential and inhibiting cytochrome C,and epimedium glycoside plays a role in reducing β-amyloid deposition.In addition,herbal compounds and single drugs promote myocardial repair by activating or inhibiting specific signaling pathways,such as PI3K/AKT and nuclear factor-κB signaling pathways.Future studies should focus on the interactions between mitochondrial calcium homeostasis,autophagy and pyroptosis pathways,as well as how TCM can exert therapeutic effects through these pathways to provide new strategies and drugs for the treatment of myocardial injury.

BACKGROUND:The capability of repairing articular cartilage damage is very limited,and tissue engineering technology provides new therapeutic options for repairing damaged cartilage,in which the interaction and induction between chondrocytes,bone marrow mesenchymal stem cells,and synovial mesenchymal stem cells is the basis of autologous healing of cartilage damage. OBJECTIVE:To construct the chondrocyte-bone marrow mesenchymal stem cell-synovial mesenchymal stem cell co-culture system to simulate the in vitro microenvironment of chondrocytes,and to explore the optimal cell inoculation ratio,meanwhile to observe the effects of icariin-containing serum on the proliferation of chondrocytes and the chondrogenic differentiation of stem cells in the system. METHODS:Rat knee chondrocytes,bone marrow mesenchymal stem cells and synovial mesenchymal stem cells were extracted,cultured and identified,and a chondrocyte-bone marrow mesenchymal stem cell-synovial mesenchymal stem cell non-contact co-culture system was constructed according to different cell inoculation ratios.After 72 hours of co-culturing,the chondrocyte proliferative activity and phenotypic ability were observed,and the co-culture system with the best overall effect was selected.New Zealand white rabbits were gavaged with icariin solution(0.25 mg/mL)to prepare icariin-containing serum,and cultured in conventional complete medium(high sugar DMEM culture medium containing 10%fetal bovine serum and 1%double antibody by volume)as the control group,while the experimental group was intervened by adding 10%icariin-containing serum by volume on the basis of above.The proliferative activity of chondrocytes and the expression of collagen type II were tested for the two groups after 24 and 48 hours.The differentiation of bone marrow mesenchymal stem cells and synovial mesenchymal stem cells into chondrocytes in the co-culture system was tested by immunofluorescence staining after 14 days. RESULTS AND CONCLUSION:(1)The three kinds of cells grew normally adherently to the wall in different ratios of co-culture,where chondrocytes showed the best proliferative activity and phenotypic ability in the co-culture system when chondrocytes:bone marrow mesenchymal stem cells:synovial mesenchymal stem cells=2:1:1.(2)Compared with the control group,the proliferative activity and type II collagen expression of chondrocytes in the experimental group were significantly increased after 24 hours(P<0.01),and the two groups still had difference after 48 hours(P<0.05).The two groups showed obvious chondrogenic differentiation of bone marrow mesenchymal stem cells and synovial mesenchymal stem cells after 14 days(P<0.01),and some of the cells appeared round or oval,and the cytoplasmic type II collagen immunofluorescence staining was positive.The fluorescence intensity of the experimental group was significantly higher than that of the control group(P<0.01).(3)The results showed that the chondrocyte-bone marrow mesenchymal stem cell-synovial mesenchymal stem cell co-culture system could be successfully established by the non-contact co-culture method,and the best chondrocyte proliferative activity and phenotypic ability could be obtained when the cell ratio was 2:1:1.Icariin-containing serum had the promoting effect on chondrocyte proliferation,and chondrogenic differentiation of bone marrow mesenchymal stem cells and synovial mesenchymal stem cells in the system.

BACKGROUND:In recent years,with the rapid development of biomedicine,the study of brain aging and exosomes has attracted more and more attention,but there is no bibliometrics analysis in this field. OBJECTIVE:To objectively analyze domestic and foreign literature on brain aging and exosomes in the past 15 years,to summarize the research status,hot spots,and development trends in this field. METHODS:Using the core database of Web of Science as a search platform,we downloaded the literature on brain aging and exosomes published from the establishment of the database to December 28,2022,and analyzed the data from the aspects of country or region,institution,author,keywords,and co-cited literature using CiteSpace 6.1.R6 visualization software. RESULTS AND CONCLUSION:A total of 1 045 research articles were included,and the number of publications on brain aging and exosomes research both domestically and internationally was showing an increasing trend year by year.The United States ranked first with 429 papers,and China ranked second with 277 papers.Louisiana State University ranked first with 16 articles.Professor Lukiw Walter J from Louisiana State University in the United States was the author with the highest number of publications,and Professor Bartel DP from the Massachusetts Institute of Technology was the author with the most citations.The most prolific Journal was the International Journal of Molecular Sciences.Alzheimer's disease,microRNA,gene expression,extracellular vesicles,exosomes,oxidative stress,and biomarkers are the most relevant terms.According to the research on hot topics,biomarkers have become a new research hotspot.The above results indicate that the research on brain aging and exosomes has gradually increased in the past 15 years.The research direction has gradually shifted from the initial exploration of the expression of miRNAs in central nervous system diseases related to brain aging to the search for biomarkers that can identify and diagnose neurodegenerative diseases.The study of exocrine miRNAs to protect central nervous system from damage has emerged as promising therapeutic strategy.

OBJECTIVE:Although wearable electronic devices have demonstrated potential utility as intervention tools to enhance physical activity,comprehensive evaluations of their specific effects on the healthy adolescent population remain scarce.Consequently,this article aims to systematically explore and summarize the impact of interventions based on wearable electronic devices on the physical activity and sedentary behavior of healthy adolescents,thereby providing more precise and reliable evidence-based support for public health practices. METHODS:Randomized controlled trials assessing the effects of wearable electronic device-based interventions on the physical activity and sedentary behavior of healthy adolescents were retrieved from databases including Web of Science,PubMed,Scopus,The Cochrane Library,and EBSCO.Meta-analysis was conducted using Review Manager 5.4 and Stata 17,evaluating the effects of interventions on physical activity and sedentary behavior through the standardized mean difference.To ensure the robustness of the research findings,a Leave-One-Out sensitivity analysis was conducted,and subgroup analyses were carried out to explore the potential influence of different factors on the results.The review protocol was registered with the International Prospective Register of Systematic Reviews(CRD42023406645). RESULTS:(1)Twelve publications were ultimately included,consisting of three randomized controlled trials and nine cluster-randomized controlled trials,involving a total of 4 933 healthy adolescents.(2)Meta-analysis results revealed that interventions based on wearable electronic devices had a positive effect on moderate to vigorous physical activity[standardized mean difference(SMD)=0.10;95%confidence interval(CI):0.04 to 0.17;P<0.05).However,the interventions did not significantly improve low-intensity physical activity(SMD=-0.15;95%CI:-0.32 to 0.02;P>0.05),daily step count(SMD=0.13;95%CI:-0.65 to 0.91;P>0.05),and sedentary behavior(SMD=0.00;95%CI:-0.09 to 0.09;P>0.05).(3)Subgroup analyses indicated that short-term interventions(≤12 weeks)(SMD=0.11;95%CI:0.03 to 0.18;P=0.008),studies using pedometers worn at the waist or hip(SMD=0.10;95%CI:0.04 to 0.17;P=0.002),and experiments registered at clinical trial centers(SMD=0.11;95%CI:0.04 to 0.17;P=0.001)had a more significant effect on enhancing daily moderate to vigorous physical activity. CONCLUSION:The current evidence suggests that interventions based on wearable electronic devices possess certain advantages in enhancing the daily moderate-to-vigorous physical activity of healthy adolescents.It is recommended that interventions not exceeding 12 weeks and utilizing pedometers positioned at the waist or hip may yield more favorable results.However,the effects of these interventions on daily step count,low-intensity physical activity,and sedentary behavior exhibit some limitations.Consequently,future investigations necessitate higher-quality,larger-scale randomized controlled trials for further validation.

BACKGROUND:Traditional surgery for lumbar disc herniation involves extensive excision of tissue surrounding the nerve for decompression and removal of protruding lumbar intervertebral discs,which poses various risks and complications such as nerve damage causing paralysis,lumbar instability,herniation recurrence,intervertebral space infection,and adjacent vertebral diseases. OBJECTIVE:To propose the symmetrically adduction of lumbar decompression induced resorption of herniated nucleus pulpous technique for lumbar spine symmetrically decompression,showing the induced resorption of herniated nucleus pulpous phenomenon and early clinical efficacy,and then analyze its decompression mechanism. METHODS:214 patients with lumbar disc herniation at Department of Orthopedics,First Affiliated Hospital of Zhengzhou University from March 2021 to May 2023 were enrolled in this study.Among them,81 patients received conservative treatment as the control group,and 133 patients received symmetrically adduction of lumbar decompression induced resorption of herniated nucleus pulpous treatment as the trial group.Before surgery,immediately after surgery(7-14 days),and early after surgery(over 1 year),MRI images were used to measure the volume changes of lumbar disc herniation.CT images were used to measure the posterior displacement distance of the lumbar spinous process ligament complex,as well as the width and height of the lateral recess.Japanese Orthopaedic Association scores were used to evaluate the patient's neurological function recovery. RESULTS AND CONCLUSION:(1)Control group:81 patients with lumbar disc herniation were treated conservatively,with a total of 171 herniated lumbar discs.The average follow-up time was(22.7±23.1)months.The first and second MRI measurements of 171 herniated lumbar discs showed herniated lumbar disc volumes of(551.6±257.9)mm3 and(792.2±330.4)mm3,respectively,with an average volume increase rate of(53.2±44.4)%,showing statistically significant differences(P<0.001).Out of 171 herniated lumbar discs,4 experienced natural shrinkage,with an absorption ratio of 2.3%(4/171)and an absorption rate of(24.5±9.9)%.(2)Trial group:133 patients with lumbar disc herniation had a total of 285 herniated lumbar discs.(1)Immediately after surgery:All patients were followed up immediately after surgery.229 out of 285 herniated lumbar discs experienced retraction,with an absorption ratio of 80.3%(229/285)and an average absorption rate of(21.5±20.9)%,with significant and complete absorption accounting for 6.5%.There were a total of 70 herniated lumbar discs in the upper lumbar spine,with an absorption ratio of 85.7%(60/70),an average absorption rate of(23.1±19.5)%,and a maximum absorption rate of 86.6%.There were 215 herniated lumbar discs in the lower lumbar spine,with an absorption ratio of 78.6%(169/215),an average absorption rate of(21.0±21.3)%,and a maximum absorption rate of 83.2%.Significant and complete absorption of the upper and lower lumbar vertebrae accounted for 5.7%and 6.5%,respectively,with no statistically significant difference(P>0.05).The average distance of posterior displacement of the spinous process ligament complex immediately after surgery was(5.2±2.8)mm.There were no significant differences in the width and height of the left and right lateral recess before and immediately after surgery(P>0.05).The Japanese Orthopaedic Association score immediately after surgery increased from(10.1±3.4)before surgery to(17.0±4.8),and the immediate effective rate after surgery reached 95.6%.(2)Early postoperative period:Among them,46 patients completed the early postoperative follow-up.There were 101 herniated lumbar discs,with an absorption ratio of 94%(95/101)and an average absorption rate of(36.9±23.7)%.Significant and complete absorption accounted for 30.6%,with a maximum absorption rate of 100%.Out of 101 herniated lumbar discs,3 remained unchanged in volume,with a volume invariance rate of 2.97%(3/101).Out of 101 herniated lumbar discs,3 had an increased volume of herniated lumbar discs,with an increase ratio of 2.97%(3/101)and an increase rate of(18.5±18.4)%.The Japanese Orthopaedic Association score increased from preoperative(9.3±5.1)to(23.5±4.0),with an excellent and good rate of 93.4%.(3)The early postoperative lumbar disc herniation absorption ratios of the control group and trial group were 2.3%and 85.9%,respectively,with statistically significant differences(P<0.001).(4)Complications:There were two cases of incision exudation and delayed healing in the trial group.After conservative treatment such as dressing change,no nerve injury or death occurred in the incision healing,and no cases underwent a second surgery.(5)It is concluded that symmetrically adduction of lumbar decompression induced resorption of herniated nucleus pulpous is a new method for treating lumbar disc herniation that can avoid extensive excision of the"ring"nerve and achieve satisfactory early clinical efficacy.It does not damage the lumbar facet joints or alter the basic anatomical structure of the lateral recess,fully preserves the herniated lumbar discs,and can induce significant or even complete induced resorption of herniated nucleus pulpous.Symmetrically adduction of lumbar decompression induced resorption of herniated nucleus pulpous provides a new basis and method for the clinical treatment of lumbar disc herniation.

Objective: To explore the relationship between visual acuity and physical fitness of university freshmen, so as to provide reference for myopia prevention and control for freshmen. Methods: From October to November 2022, 2 160 college freshman without majoring in public safety administration, selected from Guangxi Police College in 2022 by using the stratified cluster random sampling method, were reviewed for the results of visual acuity test and physical fitness scores. The physical fitness indices were evaluated by using the Z scores of physical fitness test scores, and the strength of association between the level of physical fitness index and myopia was analyzed by using Logistic regression model. Results: Among 2 160 college freshman without majoring in public safety administration, 917 (42.5%) students were diagnosed screening myopia, including 66 (3.1%) cases of high myopia, 383 (17.7%) cases of moderate myopia and 468 (21.7%) cases of mild myopia. The differences in the distribution of visual acuity tests among students with different physical fitness indices, body mass index, and gender were statistically significant ( Z/H=54.50, 49.53, 15.51, P <0.01). Low level and low middle level physical fitness indices were associated with screening myopia among freshmen[ OR (95% CI )=2.81(1.93-4.08),1.87(1.38-2.54)], and low level physical fitness indexes were associated with high myopia [ OR (95% CI )=7.22(2.33-22.32)] ( P <0.01). Conclusions Screening myopia among college freshman without majoring in public safety administration is related to physical fitness, and low level and low middle level physical fitness index are risk factors for myopia. Improving the level of physical fitness might be effective in preventing myopia.

Objective: To construct a scientific and perfect evaluation index system of infectious disease prevention and control ability in colleges and universities, so as to provide reference tools for colleges and universities to effectively respond to infectious disease. Methods: The initial framework of the evaluation index system of infectious disease prevention and control ability in colleges and universities was constructed by using literature analysis method. Experts familiar with infectious disease prevention and control or school health work were selected to conduct two rounds( n =16，18) of Delphi expert consultation for determining the evaluation index system. Analytical hierarchy process was used to calculate the index weights and combined weights. About 198 prevention and control personnel were conveniently selected from 3 universities in Inner Mongolia Autonomous Region to comprehensively evaluate the evaluation indicators by using fuzzy comprehensive evaluation method. Results: After two rounds of Delphi consultation questionnaire, the effective recovery rates were 80.0% and 90.0%, the expert authority levels were 0.89 and 0.86, the expert harmony coefficients for Kendall W were 0.166 and 0.310, and the variation coefficient of each index was <0.25. Finally, the evaluation index system of infectious disease prevention and control ability of colleges and universities included 4 first level indicators, 14 second level indicators and 75 third level indicators. The weights of prevention and monitoring and early warning, organizational system guarantee, emergency management, rehabilitation and summary were 0.176, 0.476, 0.268 and 0.080, respectively. The top 3 weights of the secondary indexes were 0.623 for infectious disease surveillance and early warning, 0.595 for loss assessment and 0.370 for emergency response. The score of fuzzy comprehensive evaluation of the index system of infectious disease prevention and control ability in colleges and universities was 79.148, suggesting a high level. Conclusion The established evaluation index system of infectious disease prevention and control ability in colleges and universities is scientific and reasonable, which is conducive to provide tool reference for the evaluation of infectious disease prevention and control ability in colleges and universities.

Background China is the world's largest producer and consumer of cobalt. Skin exposure to excess cobalt can cause symptoms such as contact dermatitis. At present, there are few studies on skin contact of cobalt and its compounds. Objective To investigate the skin contact characteristics of cobalt and its compounds. Methods A cross-sectional study was conducted in February 2024 involving 70 workers from a hard metal tool manufacturing company and the workers were divided into four groups according to their job positions: powder mixing, sintering, automatic pressing, and grinding processing. General demographic information was collected through questionnaires. Workplace air samples were collected using personal samplers, and cobalt concentrations in workplace air were measured by inductively coupled plasma optical emission spectrometry (ICP-OES). Skin samples were collected from the workers' foreheads using cotton swabs, and urine samples were collected within 30 min after the end of their shift. Urine specific gravity was measured immediately after collection, and disqualified samples were discarded. Cobalt concentrations in the swab extracts and urine were determined by inductively coupled plasma mass spectrometry (ICP-MS). Statistical analysis was performed using Kruskal-Wallis test for multiple group comparisons, Mann-WhitneyU test for pairwise comparisons, Chi-square test for categorical variables, and Spearman's rank correlation analysis to examine the correlations among air, dermal, and urinary cobalt levels. Results The 8 h time-weighted average (TWA) cobalt concentration was (2.30±2.15) μg·m⁻³ (\begin{document}$ \bar{x}\pm s $\end{document}). The median skin exposure level was 53.8 ng·cm⁻², with a range of 4.25 ng·cm⁻² to 1090.2 ng·cm⁻². The median urinary cobalt level was 3.74 µg·L⁻¹, with a range of 0.83 to 382.9 µg·L⁻¹. Statistically significant differences in TWA cobalt concentration, skin exposure levels, and urinary cobalt levels were found between different work positions (H=9.012, P=0.029; H=16.348, P＜0.001; H=11.078, P=0.011). A positive correlation was observed between skin exposure levels and urinary cobalt levels (r=0.537, P＜0.01). Conclusion Skin contact may be one of the main sources of cobalt levels in urine. Therefore, it is essential for workers to improve skin protection and hygiene practices.