Abstract: Objective To explore the effect of optimal intervention on occupational stress in front-line workers of electronic manufacturing industry. Methods A total of 257 front-line workers in an electronic manufacturing industry were selected as the research subjects using the judgment sampling method. On the basis of the previous three-level prevention intervention model on occupational stress in labor-intensive enterprise workers，a two-year optimized "333" model of three-level prevention intervention on occupational stress was implemented in the research subjects. The pre-intervention and post-intervention occupational stress levels of job demand-control（JDC）and effort-reward imbalance（ERI）model in workers at this enterprise were evaluated using the Simple Job Stress Questionnaire and the ERI Questionnaire. Results Compared with those before intervention，the scores of job requirements dimension of JDC model，giving and intrinsic input dimensions of ERI model decreased after intervention（all P<0.01）；the scores of social support dimension of JDC model and that of return dimension of ERI model increased（all P<0.05），and the detection rates of occupational stress of both JDC and ERI models decreased （26.1% vs 10.1%，21.0% vs 8.9 % ，all P<0.01）. Conclusion Optimizing the "333" intervention mode for three-level prevention intervention of occupational stress can effectively alleviate the occupational stress levels of front-line workers in electronic manufacturing enterprises.

Objective:To compare the clinical efficacy and safety of single microneedle radiofrequency versus photodynamic therapy in the treatment of inflammatory lesions of moderate and severe facial acne vulgaris.Methods:Sixty patients with moderate to severe facial acne vulgaris were retrospectively collected from Guangzhou Institute of Dermatology between December 2021 and July 2022, including 30 patients who had received single microneedle radiofrequency treatment, and 30 patients who had received photodynamic therapy. There were no significant differences in the age, gender distribution, and severity of acne between the two groups (all P > 0.05). The patients in the microneedle radiofrequency group were treated with single microneedle radiofrequency once every 4 weeks for 2 sessions; those in the photodynamic therapy group received aminolevulinic acid-based photodynamic therapy once every 2 weeks for 3 sessions; patients in both groups were still treated with oral doxycycline for 8 weeks. After 8-week treatment, the efficacy, pain severity and incidence of adverse reactions were compared between the two groups. Statistical analysis was carried out by using chi-square test, two independent samples t-test and Mann-Whitney U test. Results:After 8-week treatment, there was no significant difference in the response rate between the microneedle radiofrequency group (93.33%, 28/30) and photodynamic therapy group (86.67%, 25/30; χ2 = 0.74, P = 0.389). No significant difference was observed in the pain severity score between the microneedle radiofrequency group (4.80 ± 2.08) and photodynamic therapy group (4.13 ± 1.86, t = 1.32, P = 0.194), and there was also no significant difference in the pain degree between the two groups ( Z = -1.13, P = 0.260). In the microneedle radiofrequency group, burning sensation occurred in 3 cases (10.00%), swelling and pain in 4 (13.33%), erythema in 2 (6.67%), and dryness and desquamation in 2 (6.67%), and no reactive acne or hyperpigmentation was observed; in the photodynamic therapy group, burning sensation occurred in 10 cases (33.33%), swelling and pain in 9 (30.00%), erythema in 8 (26.67%), reactive acne in 11 (36.67%), hyperpigmentation in 2 (6.67%), and dryness and desquamation in 11 (36.67%). Compared with the photodynamic therapy group, the microneedle radiofrequency group showed significantly decreased incidence rates of burning sensation, erythema, reactive acne, and dryness and desquamation ( χ2 = 4.81, 4.32, 13.47, 7.95, respectively, all P < 0.05) ; there was no significant difference in the incidence rates of swelling and pain as well as hyperpigmentation between the two groups ( χ2 = 2.46, 2.07, respectively, both P > 0.05) . Conclusion:Single microneedle radiofrequency showed marked efficacy equivalent to that of photodynamic therapy in the treatment of moderate to severe facial acne vulgaris, but higher safety, providing more clinical treatment options for moderate to severe facial acne vulgaris.

ObjectiveTo explore the effect of occupational stress on work-related musculoskeletal disorders (WMSDs) in electronics manufacturing workers. Methods A total of 392 front-line workers in two electronic manufacturing enterprises in Guangdong Province were selected as the research subjects using the judgment sampling method. The prevalence of WMSDs and the level of occupational stress of the research subjects were investigated using the Musculoskeletal Disorders Questionnaire and the Core Occupational Stress Scale. Results The total WMSDs detection rate was 39.5%, and the multi-site WMSDs detection rate was 30.6%. The detection rate of occupational stress was 14.8%. The total WMSDs detection rate and multi-site WMSDs detection rate in the occupational stress group were higher than those in the non-occupational stress group (65.5% vs 35.0%, 56.9% vs 26.0%, both P<0.01). Binary logistic regression analysis result showed that the risk of WMSDs in the occupational stress group was higher than that in the non-occupational stress group after adjusting the effect of confounding factors such as age, gender, job type and work days per week (P<0.01). Conclusion The occupational stress may increase the risk of WMSDs in electronics manufacturing workers. Reducing the level of occupational stress among workers in electronic manufacturing enterprises is beneficial for reducing the risk of WMSDs.

Objective To analyze result of the external quality assessment for laboratories of toxicological pathology diagnosis in organizations in China. Methods A total of 86 organizations that participated in the 2020-2021 external quality assessment in laboratory of toxicological pathology diagnosis (hereinafter referred to as "reference units") were selected as research subjects using convenient sampling method, and the assessment results were analyzed. Results The median of total score was 92, and the 0-100 percentiles were 64-100 in these 86 reference units. Among these reference units, 76 were rated as excellent, 10 as qualified, with the excellent and the qualified rate of 88.4% and 11.6%, respectively. No reference unit was rated as unqualified. The rates of excellence of the reference units in public health institutions, pharmaceutical research institutions, drug safety evaluation centers and testing companies were 95.7%, 84.2%, 85.7% and 86.7%, and the qualified rates were 4.3%, 15.8%, 14.3% and 13.3%, respectively. The distribution of excellence and qualification among the four types of reference units showed no statistical difference (P>0.05). The distribution of sample scores according to the three grades of poor, good, and excellent were 4.9%, 20.7%, and 74.5% in public health institutions, 8.6%, 23.7%, and 67.8% in pharmaceutical research institutions, 12.5%, 25.0%, and 62.5% in drug safety evaluation centers, and 5.4%, 17.5%, and 77.1% in testing companies. The proportion of excellence unit in public health institutions was higher than that in pharmaceutical research institutions (P<0.05). Conclusion The overall toxicological pathology diagnostic capabilities in China are good, and various types of reference units demonstrate comparable technical capabilities. However, there is a need for standardization of diagnostic terminology.

{L-End}Objective To establish the norm of Core Occupational Stress Scale (COSS) for electronic manufacturing industry workers in China. {L-End}Methods A total of 3 049 workers from five electronic manufacturing enterprises in four prefecture-level cities concentrated distribution of the electronics manufacturing industry in China were selected as research subjects using a stratified sampling method. COSS was used to investigate occupational stress levels, and the mean norm, percentile norm and threshold norms were established. {L-End}Results The average score of COSS for the electronic manufacturing industry workers in China was (43.5±7.4) points, and the average scores of social support, organization and reward, demand and effort, and autonomy dimensions were (9.5±3.1), (15.1±3.9), (13.1±3.0), and (5.7±2.0) points, respectively. A total score of 0.0-<47.0 points was determined as no occupational stress, 47.0-<51.0 points as mild occupational stress, 51.0-≤54.0 points as moderate occupational stress, and >54.0 points as severe occupational stress. {L-End}Conclusion The norm of COSS for workers in China's electronics manufacturing industry has been established, which can provide a reference for the evaluation and intervention of their occupational stress levels.

OBJECTIVE: To investigate the effects of subacute systemic inhalation exposure of 1,2-dichloroethane(1,2-DCE) on learning and memory in NIH mice. METHODS: Forty-five specific pathogen free healthy 7-week-old NIH mice were randomly divided into control,low-dose and high-dose groups with 5 female mice and 10 male mice in each group. The mice were exposed to 1,2-DCE at dosages of 0. 00,100. 00 and 350. 00 mg/m3 for 6 hours per day for consecutive 28 days by dynamic systemic inhalation. The neurobehavioral tests of mice were performed before and after the first to fourth weeks of exposure using the Morris water maze test. RESULTS: There was no significant difference in body weight and swimming speed among the three groups of mice( P > 0. 05). The navigation experiment results showed that the escape latency of mice in both low-and high-dose groups were longer than that of the control group at the same time point(P < 0. 05) during 1-4 weeks after exposure. In the control group,the escape latency was shorter than that of the same group before exposure( P < 0. 05). The escape latency of high-dose group prolonged with the increase of exposure time,and in the 4 th week the escape latency was significantly higher than that of the same group before exposure( P < 0. 05).The experiment results of space exploration indicated that the first time of crossing platform in low-and high-dose groups were longer than that of the control group at the second to the fourth week( P < 0. 05). The target quadrant retention time and the number of crossing the platform in the low-and high-dose groups were lower than those in the control group( P <0. 05). CONCLUSION: Subacute inhalation exposure of 1,2-DCE can impair the learning and memory ability of NIH mice.The high-dose exposure may reduce learning ability in mice in a time-effect manner.

OBJECTIVE: To observe the diagnostic capacity and its influencing factors in the toxicologic pathology diagnostic laboratories in China. METHODS: Inter-laboratory comparison of toxicologic pathology diagnosis was cosponsored by Chinese Society of Toxicology-Toxicologic Pathology Specialty Section and Guangdong Province Hospital for Occupational Disease Prevention and Treatment. Nine digital slices of digestive system lesions were screened as comparison samples,and the reference institution with toxicologic pathology diagnostic laboratories completed the diagnosis within the prescribed time. According to the three grades of “excellent”,“satisfaction”and “dissatisfaction”,the evaluation was carried out.RESULTS: A total of 74 reference institution participated in this comparison,which distributed in 20 provinces and 4 municipalities and 156 pathologists. The reference institutions were mainly distributed in North China,Southern China and East China. There was an average of 2 pathologists per laboratory,and in the quantity of academic title,the junior,intermediate,and senior was 15,70 and 46 persons respectively. Parasitic hepatocyte cysts( 97. 3%),adenocarcinoma of small intestine( 95. 9%) and polyarteritis nodosa of the pancreas( 89. 2%) had the highest rate of “excellent”grade,while the duodenal gland inflammation( 67. 6%),foam cell aggregation in colonic propria( 40. 5%) and hepatoma adenoma( 32. 4%) had the highest rate of dissatisfaction grade in the evaluation of single case. In the overall evaluation,reference laboratories reached the “excellent”grade and the “satisfaction”grade were 78. 4% and 21. 6% respectively.The number of pathologists provided by each reference laboratory had impacts on the overall evaluation level and the single case evaluation( neoplastic lesions) in the evaluation of single case( P < 0. 05). The types of the reference laboratory,the regional distribution and the grade of the academic title had no effect on the diagnostic ability( P > 0. 05). CONCLUSION: The reference laboratory is superior in diagnosing the digestive system lesions in the inter-laboratory comparison activity.The number of pathologists in the reference laboratory is one of the influencing factors of its diagnostic ability.

OBJECTIVE: To explore the molecular mechanism underlying 1,2-dichloroethane(1,2-DCE) induced apoptosis by screening differentially expressed proteins in human astrocytes( HAs). METHODS: HAs were cultured in complete medium with 1,2-DCE at various concentrations of 0-80 or 0-40 mmol/L. After 24 hours,apoptosis of HAs was evaluated using flow cytometry and staining with annexin Ⅴ-fluoresce in isothiocyanate and propidium iodide. An AAH-APO-1-2 protein chip was used to screen differentially expressed proteins and quantitative real-time polymease chain reaction(qRT-PCR) was used to verify related differentially expressed genes(DEGs). RESULTS: At 1,2-DCE concentrations of0-80 mmol/L,the total apoptosis rate of HAs increased with 1,2-DCE concentrations in a dose-dependent manner( P <0. 01). Seven different kinds of proteins were screened out by apoptotic protein chip. Among them,the expression of insulin-like growth factor-binding protein( IGFBP)-1,IGFBP-4 and cytochrome C( Cyto C) were up-regulated,while the expression of P27,cysteine aspartic acid specific protease-3( Caspase-3),B-cell lymphoma-2 interacting mediator of cell death( BIM) and BH3 interacting domain death agonist( BID) were down-regulated compared with the control group. The result of DEGs verified by qRT-PCR showed that the expression of mRNA of IGFBP-1,IGFBP-4 and Cyto C at 1,2-DCE concentrations of 40 mmol/L was up-regulated. This result was in consistent with the trend of target expression in the protein chip. The mRNA expression of Caspase-3,BIM and BID was also up-regulated. CONCLUSION: 1,2-DCE induces apoptosis of HAs through mitochondrial pathway.

OBJECTIVE: To explore the effects of sub-acute inhalation of 1-bromopropane( 1-BP) on the ultrastructure of cerebral cortex,hippocampus,cerebellum,and brainstem in male rats. METHODS: Specific pathogen free healthy male Wistar rats were randomly divided into control group and exposure group with 6 rats in each group. The rats of exposure group received 1-BP vapor at a concentration of 5 000 mg/m3. The rats in the control group were given fresh air in a dynamic inhalation chamber system for 4 weeks(6 hours/day,5 days/week). After the end of the exposure,the cerebral cortex,hippocampus,cerebellum and brainstem of rats were collected and the ultrastructural changes were observed under transmission electron microscope( TEM). RESULTS: After 3 weeks of exposure to 1-BP,the rats in the exposure group began to have unresponsiveness and decreased muscle strength in hind limbs. The body weight of exposure group was lower than that of control group from the 1 st to the 4 th week( P < 0. 05). TEM results showed destroyed structure of the myelin sheath in the region of cerebral cortex, hippocampus, cerebellum and brainstem, and irregular nucleus, vacuolar degeneration,increased lysosome of endoplasmic reticulum,mitochondrion swelling of neuron cells,karyopyknosis of astrocytes and vacuolation in the neurite of astrocytes located in the blood brain barrier( BBB). CONCLUSION: 1-BP sub-acute inhalation exposure could damage the myelin,neuron,astrocyte and BBB in male rats. The demyelination of nerve fiber and decreased permeability of BBB was particularly noticeable.

OBJECTIVE: To evaluate the diagnostic ability of toxicity pathology in patho-toxicological testing institutions in China. METHODS: The institutions participated in the 2018 Interlaboratory Comparison Activity of Toxicity Pathology Testing(hereinafter referred to as reference unit) were selected as the research subjects. The heart, spleen, skin, soft tissue, liver and mammary gland of SD rats of different groups in the 2-year carcinogenesis test were selected. The femur, knee joint and nose of Beagle dogs in the 4-week toxicity test and a total of 10 pathological tissues were selected as the comparison samples. The pathological diagnosis was carried out by the pathological diagnostic personnel of the reference unit, and the diagnostic results were reported. The expert appointed by the Toxicology and Pathology Committee of Chinese Toxicology Association compared the diagnostic results with the appointed value. RESULTS: A total of 167 pathological diagnostic personnel from 75 reference units in 24 provinces and municipalities participated in the comparison activity. The reference units were mainly distributed in East China, South China and North China, accounting for 77.3%(58/75). Totally 75 reference units fed back 750 effective diagnostic results. The qualified rates of diagnosis on heart, spleen, skin, soft tissue and breast samples were higher than 60.0%. The qualified rates of diagnosis on femur and knee joint, and nose samples were low(30.7% and 6.7%, respectively). There were 1(1.3%), 46(61.4%) and 28(37.3%) reference units rated as unqualified, qualified and excellent, respectively. CONCLUSION: Most of the testing institutions in China have a high level of patho-toxicological diagnostic ability, that can provide reliable diagnostic results for toxicology safety evaluation tests.