Association of VEGFR-2 Gene Polymorphisms With Clopidogrel Resistance in Patients With Coronary Heart Disease.

Vascular endothelial growth factor receptor 2 (VEGFR-2) plays a central role in atherogenesis. We investigated the correlation between VEGFR-2 polymorphisms and the risk of clopidogrel resistance (CR) in patients with coronary heart disease (CHD). The study involved 275 patients with CHD undergoing percutaneous coronary intervention and on antiplatelet clopidogrel therapy. The participants were divided into CR group (n = 59) and non-CR group (NCR, n = 216) based on maximum platelet aggregation measurements. VEGFR-2 gene polymorphisms, +1192C>T (rs2305948), +1416T>A (rs1870377), and -271A>G (rs7667298), were genotyped using polymerase chain reaction-restriction fragment length polymorphism. Enzyme-linked immunosorbent assay was used to measure serum transforming growth factor, beta receptor 2 levels. CR was found in 59 patients (20.45%). A significantly higher proportion of patients in the CR group had a history of diabetes mellitus compared with the NCR group (P < 0.05). Genotype and allele frequency of VEGFR-2 +1192C>T (rs2305948) was significantly higher in the CR group than in the NCR group (all P < 0.01). In the VEGFR-2 +1192C>T (rs2305948), the angina pectoris, recurrent myocardial infarction, and combined end point events were significantly more prevalent in the TT carriers than in the CC + CT carriers. In VEGFR-2 -271A>G (rs7667298), the GG carriers had a lower proportion of target lesion revascularization and angina pectoris in contrast to the AA + AG carriers (all P < 0.05). Based on our results, VEGFR-2 +1192C>T (rs2305948) polymorphism is strongly associated with increased CR and main adverse cardiovascular event incidence in patients with CHD undergoing percutaneous coronary intervention. Additionally, patients with CHD with diabetes mellitus history were more likely to develop CR. The associations of +1416T>A (rs1870377) and -271A>G (rs7667298) polymorphisms with CR were inconclusive and will need to be examined further.

Dual roles of sub-nanometer NiO in alkaline hydrogen evolution reaction: breaking the Volmer limitation and optimizing d-orbital electronic configuration.

Pt-based nanoclusters toward the hydrogen evolution reaction (HER) remain the most promising electrocatalysts. However, the sluggish alkaline Volmer-step kinetics and the high-cost have hampered progress in developing high-performance HER catalysts. Herein, we propose to construct sub-nanometer NiO to tune the d-orbital electronic structure of nanocluster-level Pt for breaking the Volmer-step limitation and reducing the Pt-loading. Theoretical simulations firstly suggest that electron transfer from NiO to Pt nanoclusters could downshift the Ed-band of Pt and result in the well-optimized adsorption/desorption strength of the hydrogen intermediate (H*), therefore accelerating the hydrogen generation rate. NiO and Pt nanoclusters confined into the inherent pores of N-doped carbon derived from ZIF-8 (Pt/NiO/NPC) were designed to realize the structure of computational prediction and boost the alkaline hydrogen evolution. The optimal 1.5%Pt/NiO/NPC exhibited an excellent HER performance and stability with a low Tafel slope (only 22.5 mv dec-1) and an overpotential of 25.2 mV at 10 mA cm-2. Importantly, the 1.5%Pt/NiO/NPC possesses a mass activity of 17.37 A mg-1 at the overpotential of 20 mV, over 54 times higher than the benchmark 20 wt% Pt/C. Furthermore, DFT calculations illustrate that the Volmer-step could be accelerated owing to the high OH- attraction of NiO nanoclusters, leading to the Pt nanoclusters exhibiting a balance of H* adsorption and desorption (ΔGH* = -0.082 eV). Our findings provide new insights into breaking the water dissociation limit of Pt-based catalysts by coupling with a metal oxide.

Pt3Sn nanoparticles enriched with SnO2/Pt3Sn interfaces for highly efficient alcohol electrooxidation.

Pt3Sn nanoparticles (NPs) enriched with Pt3Sn/ultra-small SnO2 interfaces (Pt3Sn@u-SnO2/NG) were synthesized through a thermal treatment of Pt2Sn/NG in a H2 atmosphere, followed by annealing under H2 and air conditions. The unique structure of Pt3Sn NPs enriched with Pt3Sn/SnO2 interfaces was observed on the Pt3Sn@u-SnO2/NG catalyst based on HRTEM. The optimized Pt3Sn@u-SnO2/NG catalyst achieves high catalytic activity with an ethanol oxidation reaction (EOR) activity of 366 mA mgPt -1 and a methanol oxidation reaction (MOR) activity of 503 mA mgPt -1 at the potential of 0.7 V, which are eight-fold and five-fold higher than those for the commercial Pt/C catalyst (44 and 99 mA mgPt -1, respectively). The Pt3Sn@u-SnO2/NG catalyst is found to be 3 times more stable and have higher CO tolerance than Pt/C. The outstanding performance of the Pt3Sn@u-SnO2/NG catalyst should be ascribed to the synergetic effect induced by the unique structure of Pt3Sn NPs enriched with Pt3Sn/SnO2 interfaces. The synergetic effect between Pt3Sn NPs and ultra-small SnO2 increases the performance for alcohol oxidation because the Sn in both Pt3Sn and SnO2 favors the removal of COads on the nearby Pt by providing OHads species at low potentials. The present work suggests that the Pt3Sn@u-SnO2 is indeed a unique kind of efficient electrocatalyst for alcohol electrooxidation.

Enhancement of the performance of Pd nanoclusters confined within ultrathin silica layers for formic acid oxidation.

The optimized design of highly active and stable anode electrocatalysts is essential for high performance direct formic acid fuel cells (DFAFCs). Herein, a facile and cost-effective strategy was proposed to fabricate a robust ultrasmall Pd nanocluster confined within ultrathin protective silica layers anchored on nitrogen doped reduced GO (NrGO) through generating amine functionalized graphene oxide with 3-aminopropyl triethoxysilane (APTES), followed by tuning the thickness of protective silica layers by precisely controlling the amount of tetraethylorthosilicate (TEOS). Amine functionalized graphene oxide generated by using APTES favors the formation of ultrasmall Pd nanoclusters due to the coordination of amine to PdCl24- while the confinement effect of ultrathin protective silica layers stabilizes ultrasmall Pd nanoclusters and impedes the agglomeration and sintering of ultrasmall Pd nanoclusters during electrocatalysis. As a result, the ultrasmall Pd nanoclusters (∼1.4 nm) confined in silica layers on NrGO (Pd/NrGO@SiO2) demonstrate a very high forward peak current density for formic acid oxidation (FAO) of 2.37 A mg-1, outperforming the Pd/C catalyst (0.30 A mg-1) and the Pd/rGO catalyst obtained by a conventional method (0.42 A mg-1). More importantly, our confined Pd catalysts show the highest stability of only 5% inconspicuous degradation of the initial mass activity after 1000 cycles, compared with Pd/C (almost 100% loss), Pd/rGO (61.5% loss) and Pd/NrGO (73.2% loss). These strategies in this work provide a new prospect for the design of excellent noble catalysts to overcome the challenges in the practical application of DFAFCs.

Resveratrol protects H9c2 cells against hypoxia-induced apoptosis through miR-30d-5p/SIRT1/NF-κB axis.

Previous studies have demonstrated the cardioprotective role of resveratrol (Res). However, the underlying molecular mechanisms involved in the protective role of Res are still largely unknown. H9c2 cells were distributed into five groups: normal condition (Control), DMSO, 20 mMRes (dissolved with DMSO), hypoxia (Hyp), and Res+Hyp. Cell apoptosis was evaluated using flow cytometry and protein analysis of cleaved caspase 3 (cle-caspase 3). qRT-PCR assay was performed to measure the expression of microRNA-30d-5p (miR-30d-5p). MTT assay was performed to evaluate the cell proliferation. The relationship between miR-30d- 5p and silent information regulator 1 (SIRT1) was confirmed by luciferase reporter, RNA immunoprecipitation (RIP), and western blot assays. Western blot was performed to analyze NF-κB/p65 and I-κBα expressions. Our data showed that hypoxia enhanced apoptosis and NF-κB signaling pathway, which was alleviated by Res treatment. Hypoxia increased the expression of miR-30d-5p while decreased the SIRT1expression, which was also attenuated by Res treatment. Furthermore, miR-30d-5p depletion inhibited the proliferation, reduced apoptosis and decreased the expression of cle-caspase 3 in H9c2 cells with hypoxia treatment. Luciferase reporter, RIP, and western blot assays further confirmed that miR-30d-5p negatively regulated the expression of SIRT1. Interestingly, the rescue-of-function experiments further indicated that knockdown of SIRT1 attenuated the effect of miR-30d-5p depletion on proliferation, apoptosis NF-κB signaling pathway inH9c2 cells with hypoxia treatment. In addition, the suppression of NF-κB signaling pathway increased cell viability while decreased cell apoptosis in hypoxia-mediatedH9c2 cells. Our data suggested Res mayprotectH9c2 cells against hypoxia-induced apoptosis through miR-30d-5p/SIRT1/NF-κB axis.

Structurally ordered PtSn intermetallic nanoparticles supported on ATO for efficient methanol oxidation reaction.

The development of cost-effective methanol oxidation reaction (MOR) catalysts with a high activity and stability is highly desirable for direct methanol fuel cells. In this study, the structurally ordered PtSn intermetallic nanoparticles supported on Sb-doped SnO2 (ATO) have been successfully synthesized in ethylene glycol (EG) solution at 200 °C. Pt NPs were firstly formed on ATO, followed by the transformation from Pt into hexagonal PtSn on the surface of ATO. The obtained structurally ordered PtSn intermetallic NPs supported on ATO demonstrate significantly enhanced MOR activity and durability in comparison with commercial Pt/C. Our PtSn intermetallic NPs supported on ATO show a MOR activity 4.1 times higher than that of commercial Pt/C catalysts. Accelerated durability tests indicate that the commercial Pt/C catalysts lose about 50% of their initial current density after 500 cycles while the Pt/ATO-200-3 h catalyst loses only about 15% of its initial current density. Our PtSn intermetallic NPs supported on ATO are also found to have higher CO tolerance than commercial Pt/C. This work demonstrates an important strategy to rationally design high-performance structurally ordered Pt-based intermetallic NP catalysts for fuel cells and other applications.