ObjectiveTo construct a stable monoclonal human embryonic kidney 293 （HEK293） cell line expressing recombinant human coagulation factor Ⅶ （rhFⅦ） and evaluate the expression level and procoagulant bioactivity of rhFⅦ. MethodsThe plasmid pCDNA3.1-EGFP-FⅦ was transfected into HEK293 cells to verify the effectiveness of the transfection system. The plasmid pCDNA3.1-FⅦ was transfected into HEK293 cells， and monoclonal stable transfected cell lines were selected using geneticin （G418）. The transcription of the FⅦ gene was identified by reverse transcription polymerase chain reaction （RT-PCR）. The expression level of rhFⅦ in the supernatant of the monoclonal stable transfected cell line was detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot. The concentration of rhFⅦ was determined by enzyme-linked immunosorbent assay （ELISA）， and the procoagulant activity of rhFⅦ was measured by human coagulation factor Ⅶ potency assay. ResultsHEK293 cells transfected with pcDNA3.1-EGFP-FⅦ showed green fluorescence， indicating that rhFⅦ was successfully expressed in the supernatant of HEK293 cells after transient transfection with pcDNA3.1-FⅦ. The monoclonal stable transfected cell line was obtained by G418 screening. RT-PCR identified that the FⅦ gene was integrated into the genome of the monoclonal stable transfected cell line. The cell viability was good as detected by Cell Counting Kit-8， and a single band of rhFⅦ was obtained by purification of the cell supernatant. The highest rhFⅦ expression was （1.27±0.09） mg/L， and the highest procoagulant activity was （380.29±13.80）%. ConclusionThe monoclonal HEK293 cell lines which can express rhFⅦ protein efficiently and stably with excellent procoagulant bioactivity is successfully screened.

Objective To investigate the prevalence and influencing factors of work-related musculoskeletal disorders (WMSDs) in neck, shoulders and lower back among power grid workers. Methods A total of 371 workers from a power grid enterprise in Guangdong Province were selected as the research subjects using the convenience sampling method. A cross-sectional survey of WMSDs in the neck, shoulders and waist of the workers was conducted using the modified Musculoskeletal Disorders Questionnaire. Results The overall prevalence of WMSDs among the power grid workers was 62.8%, with prevalence of 37.2%, 33.7% and 32.1% for WMSDs in neck, shoulders and lower back, respectively. Binary logistic regression analysis showed that power grid workers who did not maintain a good sitting posture or were unable to maintain good sitting posture over prolonged periods had a higher risk of neck WMSDs than those who maintained a good sitting posture (both P<0.01). A higher frequency of head-down posture during work was associated with an increased risk of neck WMSDs (both P<0.05). Female workers had a higher risk of shoulder WMSDs than male workers (P<0.05). A higher frequency of early awakening with inability to fall back asleep, as well as a higher frequency of head-down posture during work, were both associated with an increased risk of shoulder WMSDs (all P<0.05). Workers with a sedentary habit had a higher risk of shoulder WMSDs than those without (P<0.01). Workers with insufficient rest time had a higher risk of shoulder WMSDs than those with sufficient rest time (P<0.01). Both maintenance workers and managers had a higher risk of lower back WMSDs than workers in other occupational categories (all P<0.05). Workers who experienced nocturnal awakening with difficulty falling back asleep at frequency of several times per year, ≥1 time /month, ≥1 time /week, had higher risk of lower back WMSDs than those who never experienced such problem (all P<0.05). Workers with a sedentary habit and those uncertain about having a sedentary habit both had a higher risk of lower back WMSDs than those without (both P<0.05). Greater forward neck flexion during work was associated with an increased risk of lower back WMSDs (both P<0.05). Workers who occasionally tilted their necks to the side while working had a higher risk of lower back WMSDs than those who did not (P<0.05). Conclusion WMSDs are highly prevalent among power grid workers, particularly affecting the neck, shoulder, and waist. Influencing factors include individual characteristics, behavioral habits, work organization, work posture, and workload. Maintaining proper posture and adequate rest may reduce the risk of WMSDs.

Objective To explore the application value of distortion product otoacoustic emission (DPOAE) and speech in noise(SIN) testing in occupational health surveillance of noise-exposed workers. Methods A total of 220 noise-exposed workers was selected as the study subjects using the convenient sampling method. The study subjects participated questionnaire survey, personal noise exposure assessment, acoustic immittance testing, pure tone audiometry (PTA), DPOAE and SIN testing. According to PTA results, workers were enrolled into a high-frequency hearing loss (HFHL) group and a non-HFHL group. Results The detection rate of HFHL among the study subjects was 41.4%, and the detection rate of speech-frequency hearing loss was 15.9%. Workers′ bilateral DPOAE response amplitudes and signal-to-noise ratios at frequencies of 2.0-8.0 kHz in the HFHL group were lower than those in the non-HFHL group (all P<0.05). The DPOAE amplitudes at frequencies of 1.0-8.0 kHz in both ears of the study subjects were negatively correlated with the PTA threshold (all P<0.01), and were negatively correlated with age (all P<0.01). The signal-to-noise ratio loss score was higher among worker in the HFHL group than in the non-HFHL group (P<0.01) and was positively correlated with PTA thresholds (P<0.05). Conclusion DPOAE and SIN testing can detect early cochlear outer hair cell impairment and reduction of noise-related speech recognition ability in noise-exposed workers and may serve as an effective supplementary tool to routine PTA in occupational hearing surveillance.

Objective To understand the instrument distribution and capacities of inter-laboratory comparisons among occupational medical examination (OME) institutions in Guangdong Province. Methods A total of 291 OME institutions in Guangdong Province that were within the validity period of filing in June 2024 and 101 OME institutions that participated in inter-laboratory comparisons in 2023 were selected as the study subjects. Their filing categories, instrument distribution and external quality assessment in laboratories were collected and analyzed. Results The location of 291 OME institutions distributed in 21 prefectural-level cities in the province, mainly in the Pearl River Delta (PRD) region, accounting for 68.4% of the total. The public hospitals, private medical institutions, the center for disease control and prevention and occupational disease prevention and treatment institutions (hereinafter referred to as "occupational prevention institutions") accounted for 61.2%, 28.5% and 10.3%, respectively. The filing rates for physical factors, chemical factors, and dust categories among OME institutions were 91.1%, 86.9%, and 86.6%, respectively. The average number of institutional instruments, from high to low, was 53.8, 38.8 and 38.2 per unit in occupational prevention institutions, private medical institutions and public hospitals, respectively. The passing rates of inter-laboratory comparisons among OME institutions of external quality assessment in laboratories among OME institutes in Guangdong Province, from high to low were occupational prevention institutions, public hospitals and private medical institutions (96.2% vs 86.8% vs 73.0%, P<0.05). Conclusion The regional distribution of OME institutes in Guangdong Province is unbalanced, mainly concentrated in the PRD region. Low overall level of OME capacity is found in public hospitals and private medical institutions. Leading by the occupational prevention institutions, public hospitals and private medical institutions should strengthen the development and investment in OME hardware, in order to improve the OME level.

Objective To analyze the status and its influencing factors of high-frequency hearing loss (HFHL) among occupational noise-exposed workers. Methods A total of 6 764 noise-exposed workers who participated in occupational medical examinations during their employment were selected as the study subjects using the judgmental sampling method. Their pure-tone audiometry results were analyzed. Results The detection rate of HFHL among the study subjects was 10.3%. Binary logistic regression analysis result revealed that males had a higher risk of HFHL than females (P<0.05). The HFHL risk of workers increased with age (all P<0.01). Workers with longer noise exposure durations had a higher risk of HFHL (all P<0.01). Smokers had a higher detection rate of HFHL than non-smokers (P<0.01). Workers in the mining industry, electricity/heat/gas and water production and supply industry, and other industries had a higher HFHL detection rate compared with manufacturing workers (all P<0.05). Medium-sized enterprise workers had a lower HFHL detection rate compared with micro-sized enterprise workers (P<0.05), while workers in private enterprises had a higher HFHL detection rate compared with those in state-owned enterprises (P<0.05). Workers who exposed to noise combined with dust, lead, high temperature, or multiple factors had a higher HFHL risk than those only exposed to noise (all P<0.05). Conclusion Gender, age, noise exposure duration, smoking, industry, and exposure to noise combined with other occupational hazard factors are all influencing factors for HFHL among noise-exposed workers. Targeted occupational health education on noise hazard prevention and occupational medical surveillance should be strengthened for key populations in priority industries, including male workers, older employees, individuals with prolonged noise exposure, smokers, and those concurrently exposed to noise and one of the following: dust, lead, high temperatures, or multiple occupational factors.

The lung function of patients with occupational pneumoconiosis (hereinafter referred to as "pneumoconiosis") combined with chronic obstructive pulmonary disease (COPD) declines rapidly. Inhaled pharmacotherapy is crucial in the treatment of patients with pneumoconiosis combined with COPD. At present, pressurized metered-dose inhalers, dry powder inhalers, and soft mist inhalers are commonly used to deliver bronchodilators (including long-acting β2-adrenergic agonists, long-acting muscarinic antagonists, or their fixed-dose combinations) in inhaled pharmacotherapy. Peak inspiratory flow (PIF) is a commonly used indicator for evaluating the effectiveness of inhalation therapy. Patients with good coordination of hand and mouth, and a high PIF (≥30 L/min) can be treated with pressurized metered-dose inhalers or dry powder inhalers, whereas patients with poor coordination or insufficient PIF (<30 L/min) should be treated with pressurized metered-dose inhalers combined with a spacer or with nebulizers. In addition, the effectiveness of inhalation therapy is affected by individual factors, such as treatment adherence and pulmonary function, as well as drug-related factors, including the use of inhaled corticosteroids and the selection of bronchodilators. Inhaled pharmacotherapy appears to have substantial potential in the treatment of pneumoconiosis complicated with COPD. Future efforts should focus on the development of more effective inhaled drugs with fewer adverse effects and more user-friendly inhalation devices, as well as on optimizing inhalation treatment regimens to enable precision therapy and improve therapeutic efficacy.

BACKGROUND: Tissue engineering holds promise for vascular repair and regeneration by mimicking the extracellular matrix of blood vessels. However, achieving a functional and thick vascular wall with aligned fiber architecture by electrospinning remains a significant challenge. METHODS: A novel electrospinning setup was developed that utilizes an auxiliary electrode and a spring. The impact of process parameters on fiber size and morphology was investigated. The structure and functions of the scaffolds were evaluated through material characterization and assessments of cellular biocompatibility. RESULTS: The new setup enabled controlled deposition of fibers in different designed orientations. The fabricated small-diameter vascular scaffolds consisted of an inner layer of longitudinally oriented fibers and an outer layer of circumferentially oriented fibers (L + C vascular scaffold). Key parameters, including rotational speed, the utilization of the auxiliary electrode, and top-to-collector distance (TCD) significantly influenced fiber orientation. Additionally, voltage, TCD, feed rate, needle size, auxiliary electrode and collector-auxiliary electrode distance affected fiber diameter and distribution. Mechanical advantages and improved surface wettability of L + C vascular scaffold were confirmed through tensile testing and water contact angle. Cellular experiments indicated that L + C vascular scaffold facilitated cell adhesion and proliferation, with human umbilical vein endothelial cells and smooth muscle cells attaching and elongating along the fiber direction of the inner and outer layer, respectively. CONCLUSION This study demonstrated the feasibility of fabricating fiber-aligned, thick-walled vascular scaffolds using a modified electrospinning setup. The findings provided insights into how the auxiliary electrode, specific collector influenced fiber deposition, potentially advancing biomimetic vascular scaffold engineering.

Objective To investigate the situation and influencing factors of preserved ratio impaired spirometry (PRISm) among dust-exposed workers in a wooden furniture manufacturing enterprise. Methods A total of 562 dust-exposed workers from a wooden furniture enterprise in Guangdong Province were selected as the study subjects using the convenience sampling method. The result of health-status questionnaire and occupational medical examinations among the participants were studied, and the influencing factors of PRISm were studied using the binary logistic regression analysis method. Results The detection rate of PRISm was 22.1% (124/562) among the study subjects. Binary logistic regression result showed that male workers had a higher risk of PRISm than female workers (P<0.01). Current smokers had a higher risk of PRISm than non-smokers (P<0.05). Workers with longer duration of exposure to occupational hazards had a higher risk of PRISm (P<0.05), those with higher grade of small-airway dysfunction had a higher risk of PRISm (P<0.01). In terms of body mass index, overweight or obese workers showed a higher detection rate of PRISm than those with normal weight (P<0.01). Greater amount of smoking pack per year had a higher risk of PRISm (P<0.01). Conclusion Dust-exposed workers in the wooden furniture manufacturing industry show a relatively high detection rate of PRISm. Male, current smoker, longer duration of exposure to occupational hazards, small airway dysfunction, overweight or obese, and smoking pack per year are influencing factors of PRISm among the dust-exposed workers in the wooden furniture manufacturing industry.

BACKGROUND: Tissue engineering holds promise for vascular repair and regeneration by mimicking the extracellular matrix of blood vessels. However, achieving a functional and thick vascular wall with aligned fiber architecture by electrospinning remains a significant challenge. METHODS: A novel electrospinning setup was developed that utilizes an auxiliary electrode and a spring. The impact of process parameters on fiber size and morphology was investigated. The structure and functions of the scaffolds were evaluated through material characterization and assessments of cellular biocompatibility. RESULTS: The new setup enabled controlled deposition of fibers in different designed orientations. The fabricated small-diameter vascular scaffolds consisted of an inner layer of longitudinally oriented fibers and an outer layer of circumferentially oriented fibers (L + C vascular scaffold). Key parameters, including rotational speed, the utilization of the auxiliary electrode, and top-to-collector distance (TCD) significantly influenced fiber orientation. Additionally, voltage, TCD, feed rate, needle size, auxiliary electrode and collector-auxiliary electrode distance affected fiber diameter and distribution. Mechanical advantages and improved surface wettability of L + C vascular scaffold were confirmed through tensile testing and water contact angle. Cellular experiments indicated that L + C vascular scaffold facilitated cell adhesion and proliferation, with human umbilical vein endothelial cells and smooth muscle cells attaching and elongating along the fiber direction of the inner and outer layer, respectively. CONCLUSION This study demonstrated the feasibility of fabricating fiber-aligned, thick-walled vascular scaffolds using a modified electrospinning setup. The findings provided insights into how the auxiliary electrode, specific collector influenced fiber deposition, potentially advancing biomimetic vascular scaffold engineering.

Objective To explore the effect of platelet-rich fibrin(PRF)combined with sulfadiazine silver dressing on healing time and curative effect of chronic refractory wounds.Methods A total of 126 patients with chronic refractory wounds who were treated in Ningde City Hospital from December 1,2022 to December 1,2023 were selected as research objects.They were randomly divided into control group and experimental group according to odd-even number,with 63 cases in each group.The control group was treated with sulfadiazine silver dressing,and the experimental group was treated with PRF and sulfadiazine silver dressing.The curative effect,wound recovery,serum inflammatory cytokine levels and complications were compared between the two groups.Results The total effective rate of the experimental group was significantly higher than that of the control group([96.83%,61/63]vs[77.78%,49/63],χ2=10.309,P<0.05).The frequency of dressing changes and wound healing time in the experimental group were significantly less than those in the control group([4.44±1.53]times vs[9.16±2.23]times,[15.35±2.29]d vs[20.25±3.24]d,P<0.05).The reduction of wound area in the experimental group was significantly higher than that in the control group([14.95±2.80]cm2 vs[11.21±2.35]cm2,P<0.05).There was no significant difference in serum inflammatory cytokine levels between the two groups before treatment(t=0.209,0.295,0.088,P>0.05).After 14 of treatment,the levels of CRP,PCT,and IL-6 were decreased in both groups,and the levels of CRP,PCT,and IL-6 in the experimental group were significantly lower than those in the control group([1.14±0.86]mg/L vs[2.11±0.75]mg/L,[4.07±0.56]μg/L vs[4.96±0.71]μg/L,[61.54±25.33]ng/L vs[84.48±24.76]ng/L,t=6.748,7.809,5.140,P<0.05).The total incidence of complications in the experimental group was significantly lower than that in the control group(9.52%vs 25.40%,χ2=5.507,P<0.05).Conclusion PRF combined with sulfadiazine silver dressing can increase curative effects,accelerate wound healing,improve serum inflammatory markers,and reduce complications in patients with chronic refractory wounds.