Background Cooking oil fumes are closely related to immune response, and adipose tissue also plays an important role in immune regulation. At present, the biological effect and mechanism of inflammation of adipose tissue induced by oil fume exposure are not clear yet. Objective To investigate the inflammatory effect of different exposure duration of cooking fumes on adipose tissue in mice and explore the role of Nod-like receptor pyrin domain 3 (NLRP3)/cysteinyl aspartate specific proteinase 1 (Caspase 1)/interleukin (IL)-1β signaling pathway. Methods Forty 8-week-old female C57BL/6J mice were randomly divided into 3-day control group (CON₃ group), 7-day control group (CON₇ group), 3-day oil fume exposure group (COF₃ group), and 7-day oil fume exposure group (COF₇ group), with 10 mice in each group. The mice were exposed to oil fumes in a cooking oil fume formation and exposure equipment (COFFEE) for 20 min, followed by a 10-min pause, 1 h a day for consecutive 3 d or 7 d. General condition of mice was observed and body weight was measured every day. After exposure, blood was sampled from the eyeball. Serum levels of IL-6, IL-27, and IL-1β were detected by enzyme-linked immunosorbent assay (ELISA). The adipose tissue of mice was collected and observed after hematoxylin-eosin (HE) staining. The percentages of CD4⁺ and CD8⁺T cells in adipose tissue were detected by flow cytometry. Real-time quantitative PCR (RT-qPCR) was used to detect the expression levels of nuclear factor-κB (NF-κB), NLRP3, Caspase 1, and IL-1β in adipose tissue. Western blot was used to detect the expression levels of NLRP3, Caspase 1, and IL-1β in adipose. Results Compared with the corresponding control group, serum IL-6, IL-27, and IL-1β contents in the COF₃ group and the COF₇ group were significantly increased (P<0.05) except IL-6 in the COF₃ group, and the levels in the COF₇ group were significantly higher than those in the COF₃ group (P<0.05). Vacuolar lipid droplets in adipocytes decreased, cytoplasm shrank, and inflammatory cells infiltrated in the COF₇ group after HE staining. The flow cytometry results showed that the proportions of CD4⁺ and CD8⁺T cells in adipocytes of the COF₃ group and the COF₇ group were increased compared to the corresponding control group, with a significant increase in the COF₇ group (P<0.05), and the CD4⁺/CD8⁺T ratio also significantly increased progressively in the two groups (P<0.05). The results of RT-qPCR showed that compared with the corresponding control group, the mRNA expression levels of NF-κB, NLRP3, Caspase 1, and IL-1β in adipose tissue of mice in the COF₃ group and the COF₇ group were significantly increased (P<0.05, P<0.01). The mRNA expression levels of mice in each exposure group gradually increased over time. The Western blot results showed that compared with the corresponding control group, the protein expressions of NLRP3 and Caspase 1 in the COF₃ group were significantly increased (P<0.01), and the expression of IL-1β protein also increased but without statistical significance. The protein expressions of NLRP3, Caspase 1, and IL-1β in the COF₇ group were significantly higher than those in the CON₇ group (P<0.05, P<0.01). Conclusion Acute exposure to cooking oil fumes can induce significant inflammatory response in adipose tissue, and the effect gradually increases with the extension of exposure time. The mechanism of action may be related to the activation of NLRP3 inflammasome signaling pathway.

Background It is unclear if there is any combined effect of air pollutants and non-optimal temperature on metabolic syndrome, or any molecular mechanisms of related signaling pathways in the process, which requires urgent systematic research. Objective To observe the effects of combined exposure to PM_2.5 and non-optimal temperature on metabolic damage at gene and protein levels in mice, and elucidate the role of related signaling pathway in crucial organs. Methods A total of 60 six-week-old male C57BL/6J mice were randomly divided into six groups: a normal temperature-filter air group (T_N-FA), a normal temperature-concentrated PM_2.5 group (T_N-PM), a heat-filter air group (T_H-FA), a heat-concentrated PM_2.5 group (T_H-PM), a cold-filter air group (T_C-FA), and a cold-concentrated PM_2.5 group (T_C-PM). The Shanghai Meteorological and Environmental Animal Exposure System (Shanghai-METAS) was used to provide combined exposure settings of air types [concentrated PM_2.5 and filter air (FA)] and temperatures [normal (22°C), cold (4°C), and heat (30°C)] for 4 weeks. Skeletal muscle and white adipose tissue (WAT) of the mice were sampled at the end of exposure, and transcriptomics and Western blot (WB) assay were adopted to observe selected gene and protein expression levels in the samples respectively. Results The transcriptomics results indicated that the PM_2.5 exposure enhanced the number of differentially expressed genes. Specifically, 4820 genes were differentially expressed in the T_N-PM mice compared to the T_N-FA mice at normal temperature, and 1143 genes were differentially expressed in the Tc-PM mice compared to the Tc-FA mice in the cold environment. The phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signaling pathway and the endoplasmic reticulum protein processing pathway were identified as the most significant pathways in metabolic injury resulting from combined exposure to PM_2.5 and non-optimal temperature exposure. The WB results showed that exposure to PM_2.5 in the normal temperature and the cold environments led to a significant increase in the expression of p-AKT in WAT (P<0.01, P<0.05) and a significant decrease in the expression of GLUT4 (P<0.05, P<0.01). In skeletal muscle, exposure to PM_2.5 led to a significant decrease in GLUT4 (P<0.05) in all environments, with a consistent trend of change as observed in WAT. Conclusion Cold/heat exposure might promote PM_2.5-induced metabolic disorder through suppression of the AKT/GLUT4 pathway, aggravating metabolic damage.

Background Pulmonary fibrosis currently lacks screening and diagnostic methods in the early stages and effective treatments in the later stages, so there is an urgent need to explore the mechanisms and develop targeted treatments. Objective To screen the expression of differentially expressed circular RNA (circRNA) hsa_circUCK2 under pathological conditions and to explore its effect on pulmonary fibrosis. Methods In the cell-based experiments, hsa_circUCK2 was knocked down in HPF-a cells using small interfering RNA (siRNA), and HPF-a cells were stimulated by TGF-β1. Four groups were set up: si-NC group, si-circUCK2 group, si-NC+TGF-β1-treated group, and si-circUCK2+TGF-β1-treated group. Western blot assay was used to detect the expression of fibronectin (FN1) in HPF-a cells of the four groups, scratch assay was used to detect the migration ability of HPF-a cells, and CCK-8 assay was used to detect the proliferation ability of HPF-a cells in the two groups with TGF-β1 stimulation, the si-NC+TGF-β1-treated group and the si-circUCK2+TGF-β1-treated group. In the animal experiments, forty-eighty healthy SPF-grade male C57BL/6 mice were randomly divided into four groups: saline+si-con group, saline+si-circ_0000115 group, SiO₂+si-con group, and SiO₂+si-circ_0000115 group. Mouse lung circRNA mmu_circ_0000115 (mouse homolog of hsa_circUCK2) was knocked down by tracheal drip injection of siRNA, and a mouse lung fibrosis model was constructed by tracheal drip injection of SiO₂ suspension (0.2 g·kg⁻¹, 50 mg·mL⁻¹) after 48 h. Real-time fluorescence quantitative PCR was used to detect the knockout efficiency in each organ of the mouse, Western blot was applied to detect the expression of type I collagen α2 (COL1A2) in the lung tissues, and Sirius red was used to detect collagen synthesis in the lung tissues. Results In the cell-based experiments, after the knockdown of hsa_circUCK2, the Western blot results showed that the expression level of the FN1 protein in TGF-β1-stimulated HPF-a cells was significantly down-regulated (P <0.05); the CCK-8 assay and cell scratch assay showed that the down-regulation of hsa_circUCK2 gene significantly inhibited the proliferation and migration of HPF-a cells (P<0.01). In the animal experiments, the real-time fluorescence quantitative PCR results showed that among the detected organs, mmu_circ_0000115 was significantly knocked down only in the lung tissues (P<0.0001); the Western blot results showed that knocking down mmu_circ_0000115 significantly reduced the COL1A2 protein expression level when compared with the SiO₂+si-con group (P<0.0001); the Sirius red results showed that knocking down mmu_circ_0000115 significantly reduced collagen production and deposition in lung tissues of mice in the model group. Conclusion Knockdown of hsa_circUCK2 inhibits fibroblast activation and reduces collagen deposition in lung fibrosis model mice. It is suggested that the hsa_circUCK2 is involved in the process of pulmonary fibrosis and may be a potential therapeutic target for pulmonary fibrosis.

Background Long-term exposure to free silica particles will lead to fibrosis of lung tissue, and abnormal expression of microRNA (miRNA) may affect the occurrence and process of fibrosis. Objective To observed possible intervention effect of miR-204-3p overexpression adenovirus on silicosis fibrosis induced by silica dust using a silicosis rat model via non-exposed intratracheal instillation. Methods Forty SD rats were randomly divided into four groups: control group, silicosis model group, miRNA-NC group, and miR-204-3p intervention group. Under ether anesthesia, rats in the silicosis model group, miRNA-NC group, and miR-204-3p intervention group were injected with 1 mL (50 mg·mL⁻¹) of free silica dust suspension into the trachea, while the control group was injected with the same volume of normal saline. After 30 d of dust exposure, the miR-204-3p intervention group was injected with rno-mir-204 adenovirus vector to overexpress miR-204-3p, and the miRNA-NC group was given empty virus vector. After 30 d of normal feeding, the animals were sacrificed by chloral hydrate anesthesia, and the lung tissue was taken for subsequent experiments. The relative expression level of miR-204-3p in lung tissue of rats in each group was detected by real-time fluorescence quantitative PCR (RT-qPCR). HE staining, Masson staining, and Sirius red staining were used for pathological observation. Immunohistochemistry was used to detect the expression of Fibronectin and Collagen I in lung tissue of rats in each group. RT-qPCR was used to detect the relative gene expression levels of fibrosis markers Fibronectin, Vimentin, Collagen I, and Collagen III in lung tissue of rats in each group. Western blot was used to detect the protein expression levels of fibrosis markers Fibronectin, Vimentin, Collagen I, and Collagen III in lung tissue of rats in each group. Results The anatomical features of lung tissue in the control group were pink lung tissue with soft texture and smooth surface, while those in the silicosis model were grayish white tissue with hard texture and scars and grayish white silicon nodules on the surface. Compared with the silicosis model group, the color of lung tissue in the miR-204-3p intervention group became ruddy, the surface was smooth, and the texture became soft. The staining results showed that the alveolar wall of the control group was thin, there were a small number of capillaries in the alveoli, and the alveolar structure was clear and complete. In the silicosis model group, the alveolar wall became thicker, the pulmonary septum was partially broken, the alveolar structure was defective, and a large amount of collagen fibers were deposited. The alveolar structure of the miR-204-3p intervention group was relatively clear and there was a small amount of collagen fiber deposition. RT-qPCR results showed that compared with the control group, the relative expression levels of miR-204-3p in lung tissue of the silicosis model group and the miRNA-NC group were decreased (P<0.05), and the relative expression level of miR-204-3p in lung tissue of the miR-204-3p intervention group was increased (P＜0.05). The results of immunohistochemistry showed that compared with the control group, the expression levels of Fibronectin and Collagen I in lung tissue of the silicosis model group were increased (P＜0.05). Compared with the silicosis model group, the relative expression levels of Fibronectin and Collagen I in lung tissue of the rats in the miR-204-3p intervention group were significantly decreased (P<0.05). The results of RT-qPCR and Western blot showed that compared with the control group, the relative protein and gene expression levels of fibrosis factors Fibronectin, Vimentin, Collagen I, and Collagen III in lung tissue of the silicosis model group increased (P＜0.05). Compared with the silicosis model group, the relative gene and protein expression levels of fibrosis factors Fibronectin, Vimentin, Collagen I, and Collagen III in lung tissue of rats in the miR-204-3p intervention group were decreased (P＜0.05). Conclusion Silica dust can cause lung fibrosis in rats, and overexpression of miR-204-3P in vivo can reduce silicosis fibrosis in rats caused by silica dust.

Background Per- and polyfluoroalkyl substances (PFAS) are a class of persistent organic pollutants that possess potential toxicity to the human body. The production and utilization of diverse emerging PFAS have resulted in widespread human exposure. Therefore, it is imperative to establish a quantitative methodology encompassing a wide range of PFAS for a comprehensive assessment of human exposure to these compounds. Objective To establish a high-throughput quantitative method for the simultaneous determination of 53 PFAS in human serum based on ultra-high-performance liquid chromatography-Q Exactive high resolution mass spectrometry (UPLC-Q Exactive HRMS). Methods The extraction recoveries of hydrophilic-lipophilic balance (HLB) column, weak anionexchange (WAX) column, and 96-well WAX μElution plate were compared to select the SPE column with the highest recovery. The retention time and peak shape of the target compounds were compared between ACQUITY UPLC BEH C₁₈ column and Accucore aQ column, and the more cost-effective column was chosen. The effects of adding different levels of ammonium formate (0, 2, 5 and 10 mmol·L⁻¹) in mobile phase on peak shape and target response were compared to determine the optimal buffer salt concentration. The optimal spray voltage was obtained by comparing −2 kV and −4 kV. The proposed method was validated from the aspects of selectivity, standard curve, limits of detection, precision, accuracy, and matrix effect. The method was applied to 142 umbilical serum samples. Results The best recovery rate (64%-118%) was achieved by using 96-well WAX μElution plate. The optimal separation and peak shape were obtained by utilizing Accucore aQ column with H₂O-methanol (containing 5 mmol·L⁻¹ ammonium formate) as the mobile phase. Less in-source collision and better target response were observed when the spray voltage was set to −2 kV. All target analytes had a good linearity, with R² > 0.99. The limits of detection ranged from 0.01 to 0.50 μg·L⁻¹, and the recovery ranged from 69% to 127% with the precision less than 26%. A total of 31 PFAS were detected in the 142 actual samples, among which 14 PFAS had a detection frequency over 50%. Perfluorooctanoic acid showed the highest median concentration of 4.16 μg·L⁻¹, followed by 6:2 chlorinated polyfluorinated ether sulfonate and perfluorooctane sulfonates (3.50 μg·L⁻¹ and 1.59 μg·L⁻¹, respectively). Conclusion In this study, we establish a UPLC-Q Excative HRMS method for simutanious determination of 53 PFAS concentrations in serum. This method has the advantages of wide coverage of PFAS, good selectivity, and easy operation, and is suitable for biological detection with a large sample size.

Background In recent years, regional high-temperature weather in summer occurs frequently in China. Heat stroke is the most representative meteorological disease caused by high temperature. In order to improve monitoring, early warning, prevention, and control of heat stroke, it is of great significance to understand the epidemiological characteristics of heat stroke and the associated impact of heatwave. Objective To understand the epidemiological characteristics of heat stroke cases in Jinan City, and to explore the effects of heatwave exposure on heat stroke. Methods Case reports of heat stroke and daily data of meteorological factors in Jinan City from 2017 to 2022 were collected. We described the temporal, population, and regional distribution characteristics of heat stroke cases in Jinan City, and used a time-stratified case-crossover design combined with conditional logistic regression model to explore the effects of heatwave exposure on heat stroke under 12 heatwave definitions (different combinations of intensity and duration). The cut-off percentiles used for heatwave definitions were the 90th (P₉₀), 95th (P₉₅), 97.5th (P_97.5), and 99th (P₉₉) percentiles of daily mean temperature; the durations were ≥ 2 d, ≥ 3 d, and ≥ 4 d, respectively. P_i(k), where i is temperature threshold, and k is duration. For example, the definition of a heatwave was notated as P₉₀(2), indicating that the daily mean temperature is ≥ P₉₀ and lasts for ≥ 2 d. Alternatively, lag01 denotes the cumulative lag effect with a 1 d lag, and so on. Results A total of 1394 cases of heat stroke were reported in Jinan City from 2017 to 2022, including 581 mild cases and 813 severe cases, and 85 deaths were reported, with a cumulative fatality rate of 6.10%. The cases of heat stroke reported each year during the study period were concentrated from June to August and peaked in July (665 cases, 47.70%). The sex ratio of males to females in heat stroke cases was 2.02:1. A high incidence of heat stroke was in 50-89 years, with a smaller peak occurring in the age group of 50-59 years and a larger peak in the age group of 70-79 years, respectively. The high-incidence areas of heat stroke were distributed in the western part of Jinan City where city centers situated (Tianqiao District, 274 cases, 19.66%; Huaiyin District, 223 cases, 16.00%) and in the surrounding rural areas (Pingyin County, 254 cases, 18.22%). The effect of heatwave exposure on heat stroke was statistically significant during the study period. The largest effect estimates for the effect on heat stroke occurred under the heatwave definitions of P₉₉(2), P_97.5(3), and P_97.5(4) at lag04, lag03, and lag04, where corresponding OR (95%CI) values were 9.27 (4.71, 14.24), 8.95 (6.17, 12.98), and 8.22 (4.91, 13.78), respectively. The exposure-response curve showed that the risk of heat stroke tended to increase with the increase of average daily temperature. Conclusion July is the key period for the occurrence of heat stroke among Jinan City residents, while male cases are predominant, more serious cases, age concentration in the 50-89 years. The occurrence of heatwave can further increase the risk of heat stroke with a significant lag effect.

Background Under the guidance of achieving carbon peaking and carbon neutrality goals, the demand for lithium-ion batteries has increased significantly. However, during the production, use, and maintenance of lithium-ion batteries, workers are inevitably exposed to various occupational hazards, and some chemicals are nephrotoxic. Objective To evaluate the kidney function and potential determinants among male workers in a lithium-ion battery-related enterprise in Shanghai. Methods The data of occupational health examination carried out by an occupational disease prevention and control institution for workers in a lithium-ion battery-related enterprise in Shanghai were collected. The workers participating pre-employment occupational health examination were treated as a control group, and the other group was recruited from those participating periodic health examination. Serum creatinine, urea nitrogen, uric acid, and renal ultrasound were used to assess the kidney function of workers. Kidney function was classified according to the reference range of kidney function indicators in Diagnostics (9th Edition, national planning textbook for high education in medicine). Binary logistic regression and generalized linear regression were used to identify potential determinants of abnormal values in kidney function indicators in workers. Results There were 6184 workers in the control group (pre-employment) with a mean age of (27.40±4.50) years. There were 3526 workers on the job with a mean age of (29.40±4.99) years and the median time of service was 2.00 (1.00, 3.42) years. The prevalence rates of high serum creatinine, high urea nitrogen, and high uric acid, and abnormal kidney ultrasound among the control group were 0.66%, 2.47%, 30.32%, and 10.12%, respectively; the indicators in the on-the-job workers were 0.96%, 3.35%, 38.25%, and 12.68%, respectively, significantly higher than those in the control group (P<0.05). After adjusting for worker age, length of service, smoking status, drinking status, hypertension, and hyperglycemia, the binary logistic regression models showed that regular smokers had a higher risk of high urea nitrogen than nonsmokers (OR=1.411, 95%CI: 1.011, 1.969). The risk of high uric acid was lower in older workers (OR=0.966, 95%CI: 0.953, 0.979), and higher in workers with more years of service (≤1 year, OR=1.295, 95%CI: 1.093, 1.534; >1-3 years, OR=1.747, 95%CI: 1.494, 2.042; >3 years, OR=1.866, 95%CI: 1.511, 2.304), hypertension (OR=1.400, 95%CI: 1.055, 1.859), and hyperglycemia (OR=1.565, 95%CI: 1.221, 2.006). Workers who were older (OR=1.038, 95%CI: 1.022, 1.054) and had longer working years (>1-3 years, OR=1.518, 95%CI: 1.201, 1.920), occasional smoking habits (OR=1.239, 95%CI: 1.039, 1.478), regular drinking habits (OR=1.875, 95%CI: 1.139, 3.087), and hypertension (OR=1.465, 95%CI: 1.075, 1.998) were at a higher risk of renal ultrasound abnormalities. The generalized linear models showed that length of service (>1-3 years, β=1.120, 95%CI: 0.360, 1.880; >3 years, β=1.451, 95%CI: 0.543, 2.358), smoking status (occasional, β=0.818, 95%CI: 0.156, 1.479; regular, β=0.841, 95%CI: 0.066, 1.616), and hypertension (β=2.742, 95%CI: 1.390, 4.094) were the influencing factors of serum creatinine concentration in the workers. Age (β=0.014, 95%CI: 0.009, 0.019) and length of service (>1-3 years, β=0.079, 95%CI: 0.012, 0.146) were the influencing factors of urea nitrogen. Age (β=−1.759, 95%CI: −2.288, −1.231), length of service (≤1 year, β=10.676, 95%CI: 4.035, 17.316; >1-3 years, β=26.117, 95%CI: 19.962, 32.272; >3 years, β=34.558, 95%CI: 26.116, 43.001), hypertension (β=23.162, 95%CI: 11.617, 34.707), and hyperglycemia (β=15.017, 95%CI: 4.853, 25.180) were the influencing factors of uric acid. Conclusion The prevalence of abnormal kidney function of workers in selected lithium-ion battery-related enterprise is varied by age, length of service, smoking status, drinking status, hypertension, and hyperglycemia. There may be a trend that the longer the time working in a lithium-ion battery-related enterprise, the worse the workers' kidney function. Therefore, the enterprise should pay attention to the possible reasons for their changes and take targeted interventions.

Background As the population ages, there has been a growing focus on the decline in fertility. Research has identified age and fertility history as the primary influencing factors. Nevertheless, there is a deficiency in fundamental data regarding the fertility status among different industries. Objective To investigate the fertility status and influencing factors among female workers aged 22-35 years in different industries. Methods From July 2020 to February 2021, a cross-sectional survey was conducted using a staged sampling approach. This survey specifically targeted 22-35-year-old married female workers with a history of pregnancy in industries such as education, healthcare, finance, and telecommunications, totaling 22903 participants. The survey encompassed industry, demographic characteristics, pregnancy history, time to pregnancy (TTP), and other influencing factors. The influencing factors of decline in fertility were identified by chi-square test and Cox proportional hazards regression. Subsequent industry-specific Cox proportional hazards regression models were used to compared fertility decline patterns across a spectrum of industries after selected influencing factors were adjusted. Results Among the 22903 respondents, 19194 valid questionnaires were collected, with a valid recovery rate of 83.8%. The cumulative pregnancy rates (CRP) of 1-6 months and 1-12 months for the 22-35-year-old female workers were 67.23% and 91.33% respectively. The multivariate analysis showed that region, age, education level, personal annual income, housework time, coping style, gravidity, parity, and spontaneous abortion were influencing factors of fertility decline (P<0.05). Female workers with ≥3 gravidities and ≥2 spontaneous abortions had a higher risk of fertility decline, with hazard ratios (HR) and associated 95% confidence interval (95%CI) of 0.633 (0.582, 0.688) and 0.785 (0.670, 0.921) respectively (P<0.01). Compared to the education industry, the healthcare and finance industries showed a higher risk of fertility decline, with HR (95%CI) values of 0.876 (0.834, 0.920) and 0.909 (0.866, 0.954), respectively (P<0.05). These two HR (95%CI) values remained statistically significant [0.899 (0.852, 0.948) and 0.882 (0.833, 0.934) respectively, P<0.05)] after further adjustment with nine influencing factors such as region and age. Conclusion Regions, age, education level, personal annual income, housework time, coping style, pregnancy and childbirth times, and natural abortion times are influencing factors of fertility decline in female workers. Compared to the education industry, the healthcare and finance industries have a higher risk of declining fertility.

Background The staff in centers for disease control and prevention (CDC) were at a great risk for psychological distress when they were faced with outbreak-related prevention and control work and routine tasks during the COVID-19 period. Psychological resilience and burnout are two key influencing factors on psychological distress. Objective To explore the status and mechanisms of psychological resilience, burnout, and psychological distress among CDC staff. Methods From September to October 2022, a cross-sectional survey was conducted in all CDC staff in Beijing, and 2228 CDC staff from 17 units (including 1 municipality-level CDC and 16 district-level CDCs) participated the questionnaire survey. The basic information questionnaire, Connor-Davidson Resilience Scale (CD-RISC-10) Chinese version, Maslach Burnout Inventory-General Survey (MBI-GS) Chinese version, and the 10-item Kessler Psychological Distress Scale (Kessler10) Chinese version were selected in our study. Mann-Whitney U test or Kruskal-Wallis H test was used to analyze the differences in the scores of psychological resilience, burnout, and psychological distress by demographic and sociological characteristics. The correlations among the three elements were analyzed by Spearman correlation analysis. Potential influencing factors of psychological distress of the CDC staff were evaluated by multiple linear regression. A potential mediating effect of psychological resilience-burnout-psychological distress was analyzed by the mediation package of R 4.2.0, and validated by Bootstrap method. Results Of 2228 questionnaires distributed, 2022 valid questionnaires were collected, and the recovery rate was 90.75%. The median (P₂₅, P₇₅) psychological distress score of CDC staff was 13.00 (8.00, 24.00), and the number of participants with psychological distress levels of 1, 2, 3, and 4 was 358 (17.71%), 546 (27.00%), 362 (17.90%), and 756 (37.39%), respectively. The median (P₂₅, P₇₅) psychological resilience score was 24.00 (20.00, 30.00) and the median (P₂₅, P₇₅) burnout score was 38.00 (25.00, 50.00). The results of the multiple linear regression showed that psychological resilience, burnout, caring for the elderly, having a chronic disease, and monthly income had independent influences on psychological distress (P<0.05), and emotional exhaustion, cynicism, and reduced personal accomplishment (reversed) in the case of burnout had a great effect on psychological distress (P<0.05). After controlling general demographic characteristic variables, total burnout score exerted a partial mediation effect on the relationship between psychological resilience and psychological distress, with a mediation effect value of −0.439 (95%CI: −0.483, −0.397), and a total mediation effect contribution rate of 60.89%. The two dimensions of burnout (emotional exhaustion and cynicism) played a partial mediating role between psychological resilience and psychological distress, with mediating effect contribution rates of 42.44% and 41.41%, respectively. Conclusion Psychological distress among CDC staff in Beijing was prominent during COVID-19. Psychological resilience can act directly on psychological distress or indirectly on psychological distress through burnout. Both emotional exhaustion and cynicism dimensions of burnout have a partial mediating role between psychological resilience and psychological distress. Increasing psychological resilience and decreasing burnout may reduce the occurrence of psychological distress.

Background In recent years, the rising number of e-cigarette users among adolescents and the surging cases of lung injury related to e-cigarette use have attracted the attention of researchers in various fields. Objective To identify the research hotspots and trends of e-cigarette or vaping product use associated lung injury (EVALI) worldwide from 2013 to 2022 by bibliometric and visual analysis. Methods Web of Science Core Collection was selected to obtain literature related to EVALI from 2013 to 2022 across the world, statistics were calculated by country/region, institution, author, journal, cited literature, keyword, etc. CiteSpace 6.2.R1 was used for visual analysis to draw diagrams of publication trend, author cooperation network, co-citation clustering time distribution, and keyword cluster. Results A total of 888 EVALI-related papers published between 2013 and 2022 were retrieved. The number of publications was gradually increased, with a significant increase in 2020 and a decrease from 2021, but the number of citations was increased year by year. The most active country was the United States (631 articles). European and American countries cooperated closely and the centrality was prominent. Among the publishing institutions, the University of California system topped the list with 103 articles. Rahman I (27 articles) published the most articles and had a high degree of centrality; Goniewicz M L was the most cited author; and the network analysis diagram showed relatively weak collaboration between authors. The American Journal of Respiratory and Critical Care Medicine was the journal with the highest number of publications (94 articles). The top 5 cited articles were all cited more than 300 times. The leading high-frequency keywords of EVALI-related studies were nicotine (149 times), exposure (118 times), and oxidative stress (80 times). The cluster of key nodes in the co-citation network and the clustering time distribution diagram indicated youth e-cigarette addiction received widespread attention from society. From the top 25 keywords with the strongest bursts, the focus of research on the pathogenesis of EVALI gradually shifted from the oxidative stress damage associated with e-cigarette vapor to the oxidative effect of flavoring chemicals in the process of lung injury. The current research interests in this field were mainly the mechanisms of various chemicals in e-cigarettes and the heating elements that led to damage to the lungs. Conclusion EVALI is receiving continuous attention from researchers in government, medical institutions, and other organizations. A variety of e-cigarette ingredients such as flavoring chemicals may lead to varying degrees of cytotoxicity, inflammation, and lung damage. However, the pathophysiology of EVALI remains unclear. In the future, more Chinese scholars should be encouraged to participate in this field.