Transient risk of ambient fine particulate matter on hourly cardiovascular events in Tainan City, Taiwan.

BackgroundThe association between daily changes in ambient fine particulate matter (PM2.5) and cardiovascular diseases have been well established in mechanistic, epidemiologic and exposure studies. Only a few studies examined the effect of hourly variations in air pollution on triggering cardiovascular events. Whether the current PM2.5 standards can protect vulnerable individuals with chronic cardiovascular diseases remain uncertain.Methodswe conducted a time-stratified, case-crossover study to assess the associations between hourly changes in PM2.5 levels and the vascular disease onset in residents of Tainan City, Taiwan, visiting Emergency Room of Chi Mei Medical Center between January 2006 and December 2016. There were 26,749 cases including 10,310 females (38.5%) and 16,439 males (61.5%) identified. The time of emergency visit was identified as the onset for each case and control cases were selected as the same times on other days, on the same day of the week in the same month and year respectively. Residential address was used to identify the ambient air pollution exposure concentrations from the closest station. Conditional logistic regression with the stepwise selection method was used to estimate adjusted odds ratios (ORs) for the association.ResultsWhen we only included cases occurring at PM2.5>10 μg/m3 and PM2.5>25 μg/m3, very significant ORs could be observed for 10 μg/m3 increases in PM2.5 at 0 and 1 hour, implying fine particulate exposure could promptly trigger vascular disease events. Moreover, a very clear increase in risk could be observed with cumulative exposure from 0 to 48 hours, especially in those cases where PM2.5>25 μg/m3.ConclusionsOur study demonstrated that transient and low concentrations of ambient PM2.5 trigger adult vascular disease events, especially cerebrovascular disease, regardless of age, sex, and exposure timing. Warning and delivery systems should be setup to protect people from these prompt adverse health impacts

Precise Sn-Doping Modulation for Optimizing CdWO₄ Nanorod Photoluminescence

The cadmium tungstate rods have been given much attention due to their potential for usage in numerous luminescent applications. We have prepared single crystalline Sn-doped Cd1−xSnxWO4 (where x = 0, 1, 3, and 5%) nanorods (NRDs) and characterized them using refined X-ray diffraction and TEM analysis, revealing a monoclinic phase and a crystallite size that decreased from 62 to 38 nm as Sn concentration increased. Precise Sn doping modulation in CdWO4 NRDs causes surface recombination of electrons and holes, which causes the PL intensity to decrease as the Sn content rises. The chromaticity diagram shows that an increase in the Sn content caused a change in the emission color from sky blue to light green, which was attributed to the increased defect density. The photoluminescence time decay curve of all samples fit well with double-order exponential decay, and the average decay lifetime was found to be 1.11, 0.93, and 1.16 ns for Cd1−xSnxWO4, x = 0, 1, and 5%, respectively. This work provides an understanding of the behavior of Sn-doped CdWO4 NRDs during electron transitions and the physical nature of emission that could be used in bio-imaging, light sources, displays, and other applications

Modulation of Magnetic and Luminescence Properties via Control Cu-Doped in CdWO₄ Nanorods for Photocatalytic Applications

Monoclinic CdWO4 is a member of the tungstate family with great potential in diverse applications. However, CdWO4 exhibits a diamagnetic property with a wideband gap of 3.7 eV, limiting its widespread applications. This study reports significant modulation of magnetic and optical properties of hydrothermally grown single-crystalline CdWO4 nanorods with controllable substitution of Cu2+ ions at the Cd2+ site. The chemical environment of Cu and the magnetic and luminescence of nanorods were thoroughly investigated using synchrotron-based powder X-ray diffraction, temperature-dependent photoluminescence, X-ray absorption, element selective X-ray excited optical luminescence spectroscopies, a magnetometer, and micro-Raman spectroscopy. The main feature of this study is an astonishing redshift of ∼0.8 eV in the bandgap energy accompanied by a relative ∼46% drop in the internal quantum efficiency and a progressive transition from diamagnetic to an enhanced magnetization concerning the Cu content. The experimental findings show that significant modulation in optical and magnetic properties is correlated with Cu-doping-induced intermediate energy states and [CuO6] ferromagnetic clusters. The outcome of this study provides important insight into designing doped nanomaterials for photocatalytic applications