The relative contribution of PM2.5 components to the obstructive ventilatory dysfunction-insights from a large ventilatory function examination of 305,022 workers in southern China.

BACKGROUND: The new round of WHO/ILO Joint Estimates of the Work-related Burden of Disease assessment requires futher research to provide more evidence, especially on the health impact of ambient air pollution around the workplace. However, the evidence linking obstructive ventilatory dysfunction (OVD) to fine particulate matter (PM2.5) and its chemical components in workers is very limited. Evidence is even more scarce on the interactive effects between occupational factors and particle exposures. We aimed to fill these gaps based on a large ventilatory function examination of workers in southern China. METHODS: We conducted a cross-sectional study among 363,788 workers in southern China in 2020. The annual average concentration of PM2.5 and its components were evaluated around the workplace through validated spatiotemporal models. We used mixed-effect models to evaluate the risk of OVD related to PM2.5 and its components. Results were further stratified by basic characteristics and occupational factors. FINDINGS: Among the 305,022 workers, 119,936 were observed with OVD. We found for each interquartile range (IQR) increase in PM2.5 concentration, the risk of OVD increased by 27.8 (95 % confidence interval (CI): 26.5-29.2 %). The estimates were 10.9 % (95 %CI: 9.7-12.1 %), 15.8 % (95 %CI: 14.5-17.2 %), 2.6 % (95 %CI: 1.4-3.8 %), 17.1 % (95 %CI: 15.9-18.4 %), and 11 % (95 %CI: 9.9-12.2 %), respectively, for each IQR increment in sulfate, nitrate, ammonium salt, organic matter and black carbon. We observed greater effect estimates among females, younger workers, workers with a length of service of 24-45 months, and professional skill workers. Furthermore, it is particularly noteworthy that the noise-exposed workers, high-temperature-exposed workers, and less-dust-exposed workers were at a 5.7-68.2 % greater risk than others. INTERPRETATION: PM2.5 and its components were significantly associated with an increased risk of OVD, with stronger links among certain vulnerable subgroups.

Apelin Prevents and Alleviates Crystalline Silica-induced Pulmonary Fibrosis via Inhibiting Transforming Growth Factor Beta 1-triggered Fibroblast Activation.

Silicosis is a common and ultimately fatal occupational disease, yet the limited therapeutic option remains the major clinical challenge. Apelin, an endogenous ligand of the G-protein-coupled receptor (APJ), is abundantly expressed in diverse organs. The apelin-APJ axis helps to control pathological and physiological processes in lung. The role of apelin in the pathological process and its possible therapeutic effects on silicosis have not been elucidated. In this study, we found that lung expression and circulating levels of apelin were markedly decreased in silicosis patients and silica-induced fibrotic mice and associated with the severity. Furthermore, in vivo data demonstrated that pre-treatment from day 3 and post-treatment from day 15 with apelin could both alleviate silica-induced pulmonary fibrosis in mice. Besides, apelin inhibited pulmonary fibroblast activation via transforming growth factor beta 1 (TGF-ß1) signaling. Our study suggested that apelin could prevent and reverse silica-induced pulmonary fibrosis by inhibiting the fibroblast activation through TGF-ß1 signaling pathway, thus providing a new potential therapeutic strategy for silicosis and other pulmonary fibrosis.

Study on Permeability Characteristics of Porous Transparent Gels Based on Synthetic Materials.

Advanced knowledge of the permeability characteristics of transparent gels play a key role in providing a rational basis for the study of porous polymer permeability and the research on the migration behavior of superpolymer solutions. Thus, a new type of transparent gel was prepared to simulate porous media, with aim to observe and analyze the permeability characteristics of transparent gel under the conditions of our experimental design by combining a transparent soil test and simple particle image velocimetry. The experimental results showed that the permeability of the transparent gel was similar to that through actual soil. The permeability coefficients of the transparent gel under different pressure gradients varied greatly early in the experimental cycle, while changing only slightly afterward, showing an overall trend of decreasing first and then stabilizing. With the increase of the mass ratio, the permeability coefficient of the sample decreased, the distribution of the low-velocity zone of the intercepted section became wider and tended to move upward. Differences in spatial position also caused different patterns of velocity and direction. The findings presented in this paper contribute to providing a new direction for the study of porous polymer permeability and the porous migration of superpolymer solutions.

Spoofing Detection Algorithm Based on Pseudorange Differences.

Intentional spoofing interference can cause damage to the navigation terminal and threaten the security of a global navigation satellite system (GNSS). For spoofing interference, an anti-spoofing algorithm based on pseudorange differences for a single receiver is proposed, which can be used to detect simplistic and intermediate spoofing attacks, as well as meaconing attacks. Double-difference models using the pseudorange of two adjacent epochs are established followed by the application of Taylor expansion to the position relationship between the satellite and the receiver (or the spoofer). The authenticity of the signal can be verified by comparing the results of the proposed spoofing detection algorithm with the traditional least squares method. The results will differ when spoofing is present. The parameter setting of the proposed algorithm is introduced. The algorithm has the advantage of both simplicity and efficiency and needs only a single receiver and pseudorange data. A NovAtel receiver is adopted for the actual experiments. The Texas spoofing test battery (TEXBAT), as well as two other simulation experiments are used to verify the performance of the algorithm. The simulation results validate the feasibility and effectiveness of the algorithm.

[Epidemiological survey on bronchial asthma in Liaoning province].

OBJECTIVE: To survey the prevalence of asthma in urban and rural residents of Liaoning province in 1999 and evaluate the risk factors for asthma, providing data for research and preventive and therapeutic policies for control of asthma. METHODS: Stratified cluster disproportional random sampling survey was performed in 116 276 residents by common protocols and questionnaire. Asthma was diagnosed based upon case history, clinical signs and lung function tests. Univariate analysis was employed to evaluate the risk factors for asthma. RESULTS: The overall prevalence of asthma in Liaoning province was 1.25%, the male to female ratio being 1:1.64. The prevalence of asthma in adults was 1.39% and that in children was 0.48%. The onset of asthma occurring in children under the age of 14 accounted for 38.63% of the whole patients. The prevalence was higher in peasants, animal breeders and government officials. The prevalence in the rural area (1.89%) was higher than that in the urban area (0.81%) (P < 0.01). The prevalence in Shenyang city (1.66%) was higher than those in Dalian city (0.88%) (P < 0.01) and Jinzhou (0.71%) (P < 0.01) city. Risk factor analysis showed that 24.7% of the asthmatics had family history; 20.4% had allergic history, the OR of allergic rhinitis being 6.28; 26.0% had smoking history; the OR of cooking oil smoke exposure was 5.94. Asthmatic attack was induced by influenza, cold air, irritant gases and cooking oil smoke in 52.3% approximately 63.3% of the patients. Asthma induced by exercising, fatigue, emotion and allergy was found in more than 41.3% of the patients. CONCLUSIONS: Our epidemiologic data reflected the general distribution of asthma in Liaoning province. From the overall prevalence rate, it is estimated that there are about 529 700 asthmatics in the whole province. The data will be helpful for the mass prevention and treatment of asthma.