Associations of environmental cadmium exposure with kidney damage: Exploring mediating DNA methylation sites in Chinese adults.

Environmental exposure is widely recognized as the primary sources of Cadmium (Cd) in the human body, and exposure to Cd is associated with kidney damage in adults. Nevertheless, the role of DNA methylation in Cd-induced kidney damage remains unclear. This study aimed to investigate the epigenome-wide association of environmental Cd-related DNA methylation changes with kidney damage. We included 300 non-smoking adults from the China in 2019. DNA methylation profiles were measured with Illumina Infinium MethylationEPIC BeadChip array. Linear mixed-effect model was employed to estimate the effects of urinary Cd with DNA methylation. Differentially methylated positions (DMPs) associated with urinary Cd were then tested for the association with kidney damage indicators. The mediation analysis was further applied to explore the potential DNA methylation based mediators. The prediction model was developed using a logistic regression model, and used 1000 bootstrap resampling for the internal validation. We identified 27 Cd-related DMPs mapped to 20 genes after the adjustment of false-discovery-rate for multiple testing among non-smoking adults. 17 DMPs were found to be associated with both urinary Cd and kidney damage, and 14 of these DMPs were newly identified within the Chinese. Mediation analysis revealed that DNA methylation of cg26907612 and cg16848624 mediated the Cd-related reduced kidney damage. In addition, ten variables were selected using the LASSO regression analysis and were utilized to develop the prediction model. It found that the nomogram model predicted the risk of kidney damage caused by environmental Cd with a corrected C-index of 0.779. Our findings revealed novel DMPs associated with both environmental Cd exposure and kidney damage among non-smoking adults, and developed an easy-to-use nomogram-illustrated model using these novel DMPs. These findings could provide a theoretical basis for formulating prevention and control strategies for kidney damage from the perspective of environmental pollution and epigenetic regulation.

Catalytic Ozonation of Polluter Benzene from -20 to >50 °C with High Conversion Efficiency and Selectivity on Mullite YMn2O5.

Catalytic decomposition of aromatic polluters at room temperature represents a green route for air purification but is currently challenged by the difficulty of generating reactive oxygen species (ROS) on catalysts. Herein, we develop a mullite catalyst YMn2O5 (YMO) with dual active sites of Mn3+ and Mn4+ and use ozone to produce a highly reactive O* upon YMO. Such a strong oxidant species on YMO shows complete removal of benzene from -20 to >50 °C with a high COx selectivity (>90%) through the generated reactive species O* on the catalyst surface (60 000 mL g-1 h-1). Although the accumulation of water and intermediates gradually lowers the reaction rate after 8 h at 25 °C, a simple treatment by ozone purging or drying in the ambient environment regenerates the catalyst. Importantly, when the temperature increases to 50 °C, the catalytic performance remains 100% conversion without any degradation for 30 h. Experiments and theoretical calculations show that such a superior performance stems from the unique coordination environment, which ensures high generation of ROS and adsorption of aromatics. Mullite's catalytic ozonation degradation of total volatile organic compounds (TVOC) is applied in a home-developed air cleaner, resulting in high efficiency of benzene removal. This work provides insights into the design of catalysts to decompose highly stable organic polluters.

Association between meteorological factors and COVID-19 transmission in low- and middle-income countries: A time-stratified case-crossover study.

BACKGROUND: Evidence is limited regarding the association between meteorological factors and COVID-19 transmission in low- and middle-income countries (LMICs). OBJECTIVE: To investigate the independent and interactive effects of temperature, relative humidity (RH), and ultraviolet (UV) radiation on the spread of COVID-19 in LMICs. METHODS: We collected daily data on COVID-19 confirmed cases, meteorological factors and non-pharmaceutical interventions (NPIs) in 2143 city- and district-level sites from 6 LMICs during 2020. We applied a time-stratified case-crossover design with distributed lag nonlinear model to evaluate the independent and interactive effects of meteorological factors on COVID-19 transmission after controlling NPIs. We generated an overall estimate through pooling site-specific relative risks (RR) using a multivariate meta-regression model. RESULTS: There was a positive, non-linear, association between temperature and COVID-19 confirmed cases in all study sites, while RH and UV showed negative non-linear associations. RR of the 90th percentile temperature (28.1 °C) was 1.14 [95% confidence interval (CI): 1.02, 1.28] compared with the 50th percentile temperature (24.4 °C). RR of the10th percentile UV was 1.41 (95% CI: 1.29, 1.54). High temperature and high RH were associated with increased risks in temperate climate but decreased risks in tropical climate, while UV exhibited a consistent, negative association across climate zones. Temperature, RH, and UV interacted to affect COVID-19 transmission. Temperature and RH also showed higher risks in low NPIs sites. CONCLUSION: Temperature, RH, and UV appeared to independently and interactively affect the transmission of COVID-19 in LMICs but such associations varied with climate zones. Our results suggest that more attention should be paid to meteorological variation when the transmission of COVID-19 is still rampant in LMICs.

2 MeV proton irradiation effect on the performance of InAs/GaSb type-II superlattice long-wave infrared detectors.

In this work, we investigated the effect of 2 MeV proton irradiation on the performance of InAs/GaSb type-II superlattice long-wave infrared detectors by combining ground-based irradiation experiments with Stopping and Range of Ions in Matter (SRIM) computer simulations. We found that irradiation with 2 MeV protons significantly increases the dark current density of the detector by more than two orders of magnitude. At the same time, the quantum efficiency decreases by an order of magnitude. Moreover, proton irradiation degrades the device's performance by raising bulk and surface leakage currents. As the mesa size of the device increases, the proportion of surface leakage current in the total dark current drops. When the mesa size is smaller, the detector irradiation damage is greater. In addition, simulations indicate that the amount of damage produced by 2 MeV proton irradiation rises as irradiation fluences increase. The trends of the irradiation damage produced by the SRIM simulation results and the photocurrent measurements after proton irradiation are consistent, whereas the dark current measurements are identical only at small fluences.