Numerical simulation study on pore clogging of pervious concrete pavement based on different aggregate gradation

Pervious concrete (PC) pavements can effectively reduce surface runoff, but it will be clogged with time and its service life will be affected. In this study, based on three groups of PC specimens with different aggregate gradations optimized by previous experiments, the pavement-clogging simulation test is carried out using the two-way coupling of the particle flow code with computational fluid dynamics (PFC-CFD). The results show that when the gradation of aggregates in the pervious pavement is different, the volume fraction of clogging material in the pavement and the time when the volume fraction of the clogging material reaches the maximum are also different. It is related to the zigzag degree and size of the pore in the pervious pavement. The smaller the particle size of coarse aggregate in the pervious pavement, the easier it is to be clogged, and the discontinuous graded coarse aggregate has a good shielding effect on the clogging material. Different clogging material gradations have different effects on the clogging of pervious pavements. According to the aforementioned research results, researchers can select different mix ratios of anti-clogging PC according to different areas of use. The law obtained from the experiment can provide a reference for further study of the double-layer pervious pavement structure design

Cadmium exposure promotes ferroptosis by upregulating Heat Shock Protein 70 in vascular endothelial damage of zebrafish

Cadmium (Cd) exposure is a risk factor for endothelial dysfunction and cardiovascular disease. Ferroptosis is a type of cell death that relies on lipid peroxidation. Whether ferroptosis acts in Cd-induced vascular endothelial damage and the underlying mechanisms remain unclear. Herein, we found that Cd resulted in ferroptosis of vascular endothelial cells (ECs) in vivo and in vitro. In the visualized zebrafish embryos, Cd accumulated in vascular ECs, ROS and lipid peroxidation levels were increased, and the oxidoreductase system was disturbed after exposure. Moreover, Cd decreased Gpx4 in ECs and caused smaller mitochondria with increased membrane density. Accompanied by ferroptosis, the number of ECs and the area of the caudal venous plexus in zebrafish embryos were reduced, and the survival rate of HUVECs decreased. These effects were partially reversed by ferrostatin-1 and aggravated by erastin. Mechanistically, an excessive increase in Heat Shock Protein 70 (Hsp70) was identified by transcriptomics after Cd exposure. Inhibition of Hsp70 by VER-155008 or siRNA ameliorated Cd-induced ferroptosis, thereby alleviating endothelial injury. Furthermore, Hsp70 regulated Cd-induced ferroptosis by targeting multiple targets, including Gpx4, Fth1, Nrf2 and Acsl4. Our findings provide a new approach to investigating the endothelial damage of Cd and indicate that regulation of Hsp70 is an important target for alleviating this process

Engineering nanomedicines using stimuli-responsive biomaterials

The ability to engineer particles has the potential to shift the paradigm in the creation of new medicines and diagnostics. Complete control over particle characteristics, such as size, shape, mechanical property, and surface chemistry, can enable rapid translation and facilitate the US Food and Drug Administration (FDA) approval of particle technologies for the treatment of cancer, infectious diseases, diabetes, and a host of other major illnesses. The incorporation of natural and artificial external stimuli to trigger the release of drugs enables exquisite control over the release profiles of drugs in a given environment. In this article, we examine several readily scalable top-down methods for the fabrication of shape-specific particles that utilize stimuli-responsive biomaterials for controlled drug delivery. Special attention is given to Particle Replication In Nonwetting Templates (PRINT(®)) technology and the application of novel triggered-release synthetic and natural polymers