The histone deacetylase inhibitor SAHA exerts a protective effect against myocardial ischemia/reperfusion injury by inhibiting sodium-calcium exchanger.

Calcium overload performs a crucial function in the pathogenesis of myocardial ischemia-reperfusion (I/R) damage, which contributes to mitochondrial impairment and apoptosis of cardiomyocytes. Suberoylanilide hydroxamic acid (SAHA), a small molecule histone deacetylases inhibitor with modulatory capacity on Na+-Ca2+ exchanger (NCX), is proven to have protective potential towards cardiac remodeling and injury, but the mechanism remains unclear. Hence, Hence, our present research explored the modulation of NCX-Ca2+-CaMKII by SAHA in myocardial I/R damage. Our outcomes indicate that in vitro hypoxia and reoxygenation models of myocardial cells, SAHA treatment inhibited the increase in expression of NCX1, intracellular Ca2+ concentration, expression of CaMKII and self-phosphorylated CaMKII, and cell apoptosis. In addition, SAHA treatment improved myocardial cell mitochondrial swelling inhibited mitochondrial membrane potential diminution and the openness of the mitochondrial permeability transition pore, and protected against mitochondrial dysfunction following I/R injury. In vivo, SAHA treatment alleviated the decrease in FS% and EF%, the increase in the myocardial infarct area, and myocardial enzyme levels caused by I/R injury, while also reducing myocardial cell apoptosis, and inhibiting mitochondrial fission and mitochondrial membrane rupture. These results indicated that SAHA treatment alleviated myocardial cell apoptosis as well as mitochondrial dysfunction resulting from myocardial I/R impairment, and contributed to myocardial function recovery by inhibiting the NCX-Ca2+-CaMKII pathway. These findings offered additional theoretical support to explore the mechanism of SAHA as a therapeutic agent in cardiac I/R damage and develop new treatment strategies.

Atomically ordered Rh2P catalysts anchored within hollow mesoporous carbon for efficient hydrogen production.

Atomically ordered Rh2P nanoclusters encapsulated within a high-surface-area hollow mesoporous carbon nanoreactor are catalytically active for hydrogen production via the electrocatalytic hydrogen evolution reaction and the room-temperature dehydrogenation of ammonia borane.

Ultrathin and Wavy PdB Alloy Nanowires with Controlled Surface Defects for Enhanced Ethanol Oxidation Electrocatalysis.

Engineering crystalline structures/defects and elemental compositions is synthetically critical to optimize surface features of noble metal nanocrystals and thus improve their catalytic performances in various reactions. In this manuscript, we report a facile one-step aqueous synthesis of one-dimensional (1D) noble metal-metalloid alloy nanowires (NWs) with an ultrathin and wavy morphology, controlled crystalline defects, and binary PdB compositions as a highly efficient catalyst toward the electrochemical ethanol oxidation reaction (EOR). We show that the utilization of hexadecylpyridinium chloride as functional surfactant is of great importance to confine in-the-columnar epitaxial nucleation of anisotropic ultrathin PdB NWs, while the attachment growth precisely controls their surface crystalline defects with a wavy morphology. Meanwhile, this strategy is synthetically universal and can be readily extended to engineer an ultrathin wavy morphology and crystalline defect of ternary PdMB (M = Cu and Pt) alloy NWs. Owing to multiple structural and compositional merits, resultant PdB alloy NWs synergistically expose more electrocatalytically active sites and also kinetically accelerate the removal of CO-related poisons, remarkably improving electrocatalytic EOR activity and stability compared to their counterpart catalysts. Besides, wavy PdB alloy NWs are also electrochemically more active for electrocatalytic oxidation of other alcohols (methanol, glycerol, and glucose). The findings reported here thus shed a bright light on rational design of the high-performance metal alloy catalysts for their potential applications in fine chemical synthesis, fuel cells, and beyond.

Mesoporous Palladium-Boron-Sulfur Alloy Nanospheres for Efficient Hydrogen Evolution.

Ternary noble metal-metalloid-nonmetal PdBS alloy mesoporous nanospheres (MSs) with three-dimensional central-radial pore channels were prepared for an electrocatalytic hydrogen evolution reaction. The synthesis was performed via precise control in the reduction and nucleation growth of ternary PdBS alloy MSs along confined cylinder mesophases assembled by amphiphilic dioctadecyldimethylammonium chloride. The resultant PdBS alloy MSs disclosed a remarkably improved electrocatalytic performance due to their structural and compositional synergies. This finding extended our knowledge on the rational design and targeted synthesis of novel noble metal-metalloid-nonmetal alloys with desired structures and morphologies for catalysis and other applications.

Synergistic Catalysis of Binary RuP Nanoclusters on Nitrogen-Functionalized Hollow Mesoporous Carbon in Hydrogen Production from the Hydrolysis of Ammonia Borane.

Exploring highly efficient nanocatalysts for hydrogen (H2) production from catalytic hydrolysis of ammonia borane (AB) under ambient conditions and further unveiling their catalytic mechanism are of critical importance for renewable energy conversion technologies but remain big challenges. Herein, ultrafine binary RuP alloy nanoclusters homogeneously encapsulated onto nitrogen-functionalized hollow mesoporous carbon supports (RuP@NHMCs) are reported as a high-performance platinum (Pt)-free nanocatalyst for catalytic hydrolysis of AB at room temperature. Remarkable catalytic activity with a very high turnover frequency of 1774 molH2 molRu-1 min-1 and a low activation energy of 36.3 kJ mol-1 is observed based on compositional and structural synergies of RuP@NHMCs. Results of control experiments and catalytic kinetics studies reveal that the rate-determining step of catalytic hydrolysis of AB is the oxidation cleavage of a covalently stable H-OH bond, while RuP@NHMCs result in multiple electronic, functional, size, and support effects that kinetically accelerate the cleavage of attacked H-OH. Furthermore, RuP@NHMCs exhibit a good catalytic activity with a high yield of >99% for tandem hydrogenation of nitroarenes coupled with the hydrolysis of AB. We strongly believe that the catalyst design principle reported here could provide a new opportunity for synthesizing other Pt-free high-performance nanocatalysts.

Strong positive allosteric cooperativity in ternary complexes based on hydrogen-bonded aromatic amide macrocycles.

Three new hydrogen-bonded aromatic amide macrocycles with eight residues were synthesized. The first single crystal structure of this class of larger macrocycles was obtained, which reveals a saddle-like conformation. Interestingly, in sharp contrast to previous negative cooperativity in binding paraquat with cyclo[6]aramide, strong positive allosteric cooperativity in ternary complexes was observed. This may open an avenue for the construction of mechanically interlocked molecules with these larger H-bonded macrocycles.