PCSK9 inhibitors ameliorate arterial stiffness in ACS patients: evidences from Mendelian randomization, a retrospective study and basic experiments.

Background: Current evidences suggest that Proprotein Convertase Subtilisin/kexin Type 9 inhibitors (PCSK9i) exhibit a protective influence on acute coronary syndrome (ACS). Nevertheless, further investigation is required to comprehend the impact and mechanisms of these pharmaceutical agents on inflammatory factors and arterial stiffness (AS) in patients with ACS. Consequently, the objective of this study is to ascertain the influence of PCSK9i on arterial stiffness in ACS patients and elucidate the underlying mechanisms behind their actions. Methods: This study employed Mendelian randomization (MR) analysis to examine the association between genetic prediction of PCSK9 inhibition and arterial stiffness. Data of 71 patients with ACS were retrospectively collected, including PCSK9i group (n = 36, PCSK9 inhibitors combined with statins) and control group (n = 35, statins only). Blood lipid levels, inflammatory markers and pulse wave velocity (PWV) data were collected before treatment and at 1 and 6 months after treatment for analysis. Additionally, cell experiments were conducted to investigate the impact of PCSK9i on osteogenesis of vascular smooth muscle cells (VSMCs), utilizing western blot (WB), enzyme-linked immunosorbent assay (ELISA), and calcification index measurements. Results: The results of the MR analysis suggest that genetic prediction of PCSK9 inhibition has potential to reduce the PWV. Following treatment of statins combined with PCSK9 inhibitors for 1 and 6 months, the PCSK9i group exhibited significantly lower levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), C-reactive protein (CRP), interleukin-6 (IL-6), fibrinogen (FIB) and procalcitonin (PCT) compared to the control group (p < 0.05). Additionally, PWV in the PCSK9i group demonstrated significant reduction after 6 months of treatment and was found to be associated with the circulating CRP level. In cell experiments, PCSK9i pretreatment ameliorated osteogenesis of VSMCs through reducing the deposition of calcium ions, alkaline phosphatase (ALP) activity, and expression of runt-related transcription factor 2 (RUNX2). Conclusion: PCSK9i have potential to enhance arterial stiffness in ACS patients. Specifically, at the clinical level, this impact may be attributed to alterations in circulating CRP levels. At the cellular level, it is associated with the signaling pathway linked to RUNX2.

CFD modeling of ethylene degradation in gas-phase photocatalytic reactors.

Photocatalytic oxidation is a promising technology to degrade volatile organic compounds. The performance of photocatalytic reactors is affected by the hydrodynamics, radiation transfer, mass transfer and reaction kinetics. Baffles may improve the hydrodynamics. The effect of baffles on heterogeneous photocatalytic oxidation of gas-phase ethylene in three annular reactors is simulated using computational fluid dynamics. ANSYS Fluent is used to solve all governing equations. Baffles can improve the uniformity of flow and prolong the residence time. The residence time of the C-type reactor and B-type reactor is 0.5% greater than the unbaffled reactor. Baffles have little effect on the radiation distribution. The concentric arrangement of lamp and the reactor leads to a radial dominance of radiation. The effect of baffles on the diffusion of ethylene is complex. The effective diffusion coefficient at the catalyst surface in the C-type reactor decreases 9.5% and that in the B-type reactor increases 3% with respect to the unbaffled reactor. The outlet ethylene concentration is 4.19 ppmv for the U-type reactor, 3.93 ppmv for the C-type reactor and 3.62 ppmv for the B-type reactor. The optimal performance in the B-type reactor is due to the large diffusion coefficient of ethylene. The arrangement of baffles should enlarge the effective diffusion coefficient at the catalyst surface as far as possible.

Salt inhibition on partial nitritation performance of ammonium-rich saline wastewater in the zeolite biological aerated filter.

Influences of various concentrations of salinity (NaCl 0-25.0 g/L) on partial nitritation performance in a zeolite biological aerated filter (ZBAF) were investigated. The highest nitrite production rate (NPR) of 1.357 kg/(m3·d) and nitrite accumulation rate (NAR) of 99.0% was achieved with salt free wastewater. While after adding extra salt, NPR and ammonium removal efficiency (ARE) presented an obvious decline trend. The lowest NPR (0.599 kg/(m3·d)) and ARE (34.2%) were obtained with salinity of 25.0 g/L NaCl. It has been confirmed that addition of salt resulted in the increase of free ammonia (FA), and then further inhibited ammonium oxidizing bacteria (AOB). High-throughput sequencing analysis results further revealed that the relative abundance of AOB decreased in ZBAF. All results demonstrated that AOB was inhibited not only by high osmotic pressure caused by salt, but also by high FA.