PtCoNi ternary intermetallic compounds anchored on Co,Ni and N co-doped mesoporous carbon:Synergetic effect between PtCoNi nanoparticles and doped mesoporous carbon promotes the catalytic activity

Highly active and robust electrocatalysts are desired for proton exchange membrane fuel cells.Pt-based intermetallic compounds(IMCs) have been recognized as one of the most promising low-platinum catalysts for fuel cells(FCs).Herein,we report a high-performance IMCs by anchoring ordered PtCoNi ternary nanoparticles on the N,Co and Ni co-doped dodecahedral mesoporous carbon(DMC).While the introduced Co and Ni participate in the formation of PtCoNi IMCs,some of them are doped in the mesoporous carbon and coordinated by N to form Co-N_(y)/Ni-N_(z)dual active centers,which further enhances the electrocatalytic activity towards oxygen reduction reaction.Moreover,the addition of Ni results in a negative shift of the d-band center of Pt as compared to the Pt/DMC and Pt_(3)Co/DMC,making it easier to adsorb oxygen on the surface.As expected,our optimal sample Pt_(3)Co_(0.7)Ni_(0.3)/DMC exhibits excellent performance with mass activity and specific activity of 1.32 A mgPt-1and 1.98 mA cm^(-2)at 0.9 V,which are 7.33and 6.19 times that of commercial Pt/C,respectively.The Pt_(3)Co_(0.7)Ni_(0.3)/DMC also reveals much better cathodic performance in an H2-air single fuel cell than commercial Pt/C catalyst with a power density of0.802 W cm^(-2).This work provides critical sights into constructing efficient catalysts by ternary intermetallic strategy and synergetic effect between active components and support.

Mediating Role of Glucose-Lipid Metabolism in the Association between the Increased Risk of Coronary Heart Disease and Exposure to Organophosphate Esters,Phthalates,and Polycyclic Aromatic Hydrocarbons

There is a lack of human evidence concerning the cardiovascular effects of combined exposure to endocrine disruptors.This case-control study sought to investigate coronary heart disease(CHD)associations with exposure to organophosphate flame retardants(OFRs),phthalates(PAEs),and polycyclic aromatic hydrocarbons(PAHs)among 148 adults with coronary-angiography-diagnosed CHD and 320 healthy adults from southern China.The mediating role of glucose-lipid metabolism was also explored.Bayesian kernel machine regression suggested that when exposure status was fixed to the 75th percentile with the median value as the reference,exposure to OFRs,PAEs,and PAHs was associated with an 84%(95%CI:36%−134%),132%(12%−252%),and 214%(89%−331%)increased risk of developing CHD,respectively.Weighted quantile sum regression indicated urinary bis(2-butoxyethyl)phosphate(BBOEP),dibutyl phosphate(DBP),monoisononyl phthalate(miNP),and metabolites of phenanthrene may be major contributors to the overall effect of mixtures.In further analyses on identified chemical risk factors,mediation analyses suggested exposure to phenanthrene may increase the risk of CHD via elevating total cholesterol and blood glucose,while exposure to DiNP mainly associates with serum lipids.Besides,we observed a slight mediation effect of oxidative DNA damage between urinary BBOEP and risk of CHD.These results provide potential direction for further experimental studies.Longitudinal evidence is needed to clarify the causation of the results.

Emerging Evidence Linking the Liver to the Cardiovascular System: Liver-derived Secretory Factors

Cardiovascular diseases(CVDs)remain the leading cause of morbidity and mortality worldwide.Recently,accumulating evidence has revealed hepatic mediators,termed as liverderived secretory factors(LDSFs),play an important role in regulating CVDs such as atherosclerosis,coronary artery disease,thrombosis,myocardial infarction,heart failure,metabolic cardiomyopathy,arterial hypertension,and pulmonary hypertension.LDSFs presented here consisted of microbial metabolite,extracellular vesicles,proteins,and microRNA,they are primarily or exclusively synthesized and released by the liver,and have been shown to exert pleiotropic actions on cardiovascular system.LDSFs mainly target vascular endothelial cell,vascular smooth muscle cells,cardiomyocytes,fibroblasts,macrophages and platelets,and further modulate endothelial nitric oxide synthase/nitric oxide,endothelial function,energy metabolism,inflammation,oxidative stress,and dystrophic calcification.Although some LDSFs are known to be detrimental/beneficial,controversial findings were also reported for many.Therefore,more studies are required to further explore the causal relationships between LDSFs and CVDs and uncover the exact mechanisms,which is expected to extend our understanding of the crosstalk between the liver and cardiovascular system and identify potential therapeutic targets.Furthermore,in the case of patients with liver disease,awareness should be given to the implications of these abnormalities in the cardiovascular system.These studies also underline the importance of early recognition and intervention of liver abnormalities in the practice of cardiovascular care,and a multidisciplinary approach combining hepatologists and cardiologists would be more preferable for such patients.

钾离子电池及其最新研究进展

钾元素在地壳中的储量丰富、来源广泛,且物理化学性质与锂元素相似,在离子电池领域中具有广阔的发展前景。但相比于锂离子,钾离子半径较大,在材料体相中的迁移速度较慢,并使得材料承受较大的结构应力,从而导致钾离子电池的电化学性能优势不足。因此,开发具有稳定结构、能够可逆嵌脱的正负极材料和与之相匹配的电解液,成为钾离子电池目前研究的热点话题。本文主要从钾离子电池的正极材料、负极材料以及电解液三方面来介绍钾离子电池在国内外最新研究进展,并对钾离子电池未来发展方向做出一定的展望。

三元镍钴锰正极材料的制备及改性

三元镍钴锰正极材料是一类非常重要的正极材料,具有性能优于钴酸锂而成本远远低于钴酸锂、能量密度远远高于磷酸铁锂等重要优点,正在逐渐成为汽车动力电池的主流正极材料。但是,三元镍钴锰正极材料也存在循环稳定性不足、大电流密度放电性能不佳等问题。围绕解决这些问题并进一步提升三元镍钴锰正极材料的性能,近年来国内外在材料制备技术以及改性技术方面开展了大量的研究工作,取得了若干令人瞩目的研究成果。本文从材料制备方法、包覆修饰和掺杂改性三个方面,介绍了三元镍钴锰正极材料制备技术及改性技术的研究进展,在此基础上,对三元镍钴锰正极材料的未来发展方向作出展望。