Search

High-cholesterol diet (HCD) and fine particulate matter (PM2.5) are related to stroke. However, little is known about the combined effects of stroke, especially for females. This study investigated the brain injuries in Apolipoprotein E−/− (ApoE−/−) female mice exposed to HCD plus PM2.5 for 6 months. The protein levels of the genes related to stroke and the blood–brain barrier (BBB) in different groups of mice were measured. The molecular regulation mechanisms were explored. The results showed that HCD and PM2.5 co-exposure altered brain–body weight ratio, behavior, brain pathology, and inflammatory markers in mice relative to exposure to HCD or PM2.5 alone. Co-exposure significantly changed the expressions of HIF-1α and the key genes in its signaling pathway in the brains of mice compared to the single exposure. It suggests that the HIF-1α pathway exerts an important regulatory role in brain injury and behavioral abnormality in female mice after 6-month exposure to HCD plus PM2.5, which are potential mechanisms for HCD and PM2.5-triggering stroke in female individuals. [ABSTRACT FROM AUTHOR]

Climate warming and air pollution are atmospheric environmental problems that have aroused broad concern worldwide. Greenhouse gas emissions are the main cause of global warming. In addition to reducing carbon emissions, increasing carbon sink capacity and improving environmental quality are essential for building green and low-carbon enterprises under carbon peak and carbon neutrality goals. Currently, the research on the methods and application of carbon sink capacity assessment in coal mining enterprises is limited. Given this, this study estimated the carbon absorption, carbon storage, and net ecosystem productivity of a typical coal mining area in Taiyuan City, China, and compared the characteristics and applicability of the three methods. The results showed the following: (1) The total carbon absorption (carbon sink) of the mining area in 2021 was 117.39 t, the primary source of which is forest land. (2) The total carbon storage in the mining area in 2021 was 29,561.96 t. From different land use types, the carbon storage in the mining area mainly came from forest land (27,867.73 t); from the perspective of carbon pool, soil carbon storage (21,970.96 t) had the most significant contribution to the carbon storage of mining areas. (3) The net ecosystem productivity of the mining area in 2021 was 781.97 g/(m2·a), indicating that the ecosystem of the mining area was a carbon sink. (4) The three estimation methods differed in the current case. The estimation method for carbon absorption is the simplest, and the results are the most intuitive. The estimation method for net ecosystem productivity is the most complex. The carbon sink estimation via carbon storage needs to collect two years of data. Enterprises should assess the carbon sink capacity of mining areas based on existing conditions and data. This study proposes methods for estimating carbon sink capacity in mining areas, which have positive practical significance for the low-carbon green development of coal mine enterprises. [ABSTRACT FROM AUTHOR]

The atmosphere's fine particulate matter (PM2.5) can enter the liver through the circulatory system, leading to hepatic inflammation and fibrosis. As a non-flavonoid polyphenolic compound, resveratrol (RES) has anti-oxidant, anti-inflammatory and hepatoprotective effects, but the molecular mechanisms of liver fibrosis induced by PM2.5 exposure are still limited. In this study, we established an in vitro cell model to investigate the intervention effect of RES with different concentrations (5 and 20 μmol/mL) on mouse hepatic stellate cells (mHSCs) injury induced by PM2.5 (100 μg/mL). We determined the cell viability in mHSCs after treatment with PM2.5 or/and RES for 24 h. We investigated the intracellular oxidative stress by detecting the changes in reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD) and lactate dehydrogenase (LDH) levels. We also measured the protein expressions of fibrosis-related genes (α-SMA, Collagen I and Collagen III) and key genes (SIRT1, NF-κB, NLRP3, Cleaved-Caspase1, IL-1β) in the NLRP3 pathway in mHSCs exposed to PM2.5 with or without RES. The results showed that (1) PM2.5 has cytotoxic effects on mHSCs, whereas RES (5 μmol/L and 20 μmol/L) inhibited PM2.5-induced cytotoxicity and LDH leakage; (2) RES effectively reduces ROS and MDA production caused by PM2.5 while concurrently enhancing SOD levels, thereby improving cellular anti-oxidant capacity; (3) the expression of α-SMA, Collagen I and Collagen III were notably downregulated in the PM2.5 plus RES treatment group compared to the PM2.5-exposed group; (4) RES significantly increased SIRT1 expression and decreased the expression of NF-κB, NLRP3, Cleaved-Caspase1 and IL-1β in mHSCs exposure to PM2.5 compared to the PM2.5 group. These results demonstrate that RES can up-regulate SIRT1 and mitigate PM2.5-induced fibrosis by suppressing oxidative stress in mHSCs and the SIRT1/NF–κB/NLRP3 pathway activated by PM2.5. [ABSTRACT FROM AUTHOR]

Fine particulate matter (PM2.5) is a common pollutant, and its health risk has attracted much attention. Studies have shown that PM2.5 exposure is associated with liver disease. The composition of PM2.5 is complex, and its hepatotoxic effects and lipid metabolism process are not well understood. In this study, we detected the concentrations of PM2.5 and its components (metals and polycyclic aromatic hydrocarbon (PAHs)) in the winter in Taiyuan, Shanxi Province, China, from 2017 to 2020 and then assessed the health risks. We also investigated the effects of different components (whole particles (WP), water-soluble particles (WSP), organic particles (OP)) of PM2.5 on the cytotoxicity and lipid metabolism in human liver cell line (HepG2) after 24 h of treatment. The changes in cytotoxicity indexes (LDH, IL-6, reactive oxygen species (ROS)) and lipids (triglyceride (TG), free fatty acid (FFA)) were measured after 24 h. The mRNA expression of lipid metabolism-related factors (SREBP1, CD36, MTTP) was determined by real-time quantitative RT-qPCR. Finally, the correlation between metals and PAHs with higher PM2.5 content in 4 years and biomarkers was analyzed. The results showed that: (1) The PM2.5 pollution was severe in Taiyuan during winter in 2017 and the subsequent four years. The calculation results of the metal enrichment factor (EF) value and PAHs characteristic ratio of PM2.5 showed that PM2.5 pollution sources differed in different years. (2) Exposure to metals and PAHs in PM2.5 did not cause a non-carcinogenic risk. Metals had no cancer risk, while PAHs inhaled in PM2.5 in 2017 and 2018 had a potential cancer risk. The atmospheric PM2.5 pollution in Taiyuan has had a downward trend, but the PAHs in the PM2.5 of 2017–18, when the pollution is relatively serious, have a potential carcinogenic risk. (3) WP, OP and WSP inhibited cell survival rate from 2017 to 2020, and OP had higher cytotoxicity at the same concentration. (4) WP, OP and WSP increased the levels of LDH, IL-6, TNF-α, ROS, MDA, TG and FFA, and inhibited SOD activity in a dose-effect relationship. The organic components in PM2.5 are more toxic to HepG2 cells and affect the expression of lipid metabolism-related factors at the transcriptional level. (5) The mRNA expressions of factors related to lipid synthesis, uptake, oxidation and output were up-regulated after treatment with PM2.5 and its components, suggesting a lipid metabolism disorder. (6) The biomarkers were associated with certain metals (Zn, Pb, Cu and Cr) and PAHs in PM2.5. These suggested that PM2.5- and PM2.5-bound organic matter caused HepG2 cytotoxicity and affected lipid metabolism. [ABSTRACT FROM AUTHOR]

To realize high-precision and high-frequency unattended site calibration and detection of satellites, automatic direction adjustment must be implemented in mirror arrays. This paper proposes a high-precision automatic calibration model based on a novel point light source tracking system for mirror arrays. A camera automatically observes the solar vector, and an observation equation coupling the image space and local coordinate systems is established. High-precision calibration of the system is realized through geometric error calculation of multipoint observation data. Moreover, model error analysis and solar tracking verification experiments are conducted. The standard deviations of the pitch angle and azimuth angle errors are 0.0176° and 0.0305°, respectively. The root mean square errors of the image centroid contrast are 2.0995 and 0.8689 pixels along the x- and y-axes, respectively. The corresponding pixel angular resolution errors are 0.0377° and 0.0144°, and the comprehensive angle resolution error is 0.0403°. The calculated model values are consistent with the measured data, validating the model. The proposed point light source tracking system can satisfy the requirements of high-resolution, high-precision, high-frequency on-orbit satellite radiometric calibration and modulation transfer function detection. [ABSTRACT FROM AUTHOR]