Insight into the Catalytic Oxidation Mechanism of Hydrogen Isotopes by Pt Clusters Confined by Silicalite-1.

Highly efficient removal of low concentrations of hydrogen isotope gas in air is crucial for the safe operation of nuclear energy plants. Herein, silicalite-1-confined Pt cluster catalysts were used for the catalytic oxidation of hydrogen isotopes, and the related catalytic mechanism was revealed. Increased temperature in direct hydrogen reduction treatment slightly increased the size of Pt clusters from 1.6 nm at 400 °C to 1.8 nm at 600 °C. The catalyst reduced at 600 °C exhibited excellent performance (99%) in hydrogen isotope oxidation at 75 °C, as well as high stability and catalytic efficiency in continuous and intermittent operation for 7200 min. X-ray absorbance spectroscopy confirmed the existence of Pt clusters in the catalysts, and the theoretical results showed that the total net charge was -0.07 e, indicating a slight charge transfer from the zeolite to the Pt atoms. The metal-support interaction thermally stabilized Pt clusters and altered the metal electronic structure, which enhanced the catalytic activity following a hydroperoxyl (OOH)-mediated route. Based on the low reaction temperature, efficient hydrogen conversion rate, and high stability, the silicalite-1-confined Pt cluster catalyst is expected to be used in hydrogen isotope oxidation treatment to achieve nuclear safety.

Rational design and construction of hierarchical porous quasi-hexagonal Co2P nanosheets/Co heterostructures as highly efficient bifunctional electrocatalysts for overall water splitting.

Constructing heterostructured electrocatalysts has proven effective in enhancing intrinsic catalytic activity. Herein, under guidance of theoretical calculations, hierarchical porous quasi-hexagonal Co2P nanosheets/Co heterostructures supported on carbon cloth (Co2P/Co/CC) with a high surface area were rationally designed and elaborately constructed through electroless Co plating, electrochemical oxidation, and phosphidation process, which showed significant electrocatalytic performance toward water electrolysis. Specifically, theoretical calculations revealed that the Co2P/Co heterostructure adjusted the electronic structure of Co2P and Co, reducing the energy barrier for target reactions and thereby boosting electrocatalytic activities for the hydrogen evolution reaction (HER). Notably, the typical Co2P/Co/CC catalyst demonstrated impressive HER performance, with low overpotentials of only 52 and 48 mV to achieve a current density of 10 mA/cm2 in 0.5 M H2SO4 and 1.0 M KOH solutions, respectively. The remarkable electrocatalytic performance of the catalyst can be attributed to the improved intrinsic activity resulting from the Co2P/Co heterostructures and the highly exposed active sites provided by the hierarchical porous structures. Furthermore, the Co2P/Co/CC catalyst exhibited excellent oxygen evolution reaction (OER) performance in alkaline electrolyte, requiring a low overpotential of only 306 mV to achieve a current density of 100 mA/cm2. Additionally, a two-electrode electrolyzer assembled with the Co2P/Co/CC electrodes achieved a current density of 10 mA/cm2 at a low cell voltage of 1.54 V and demonstrated excellent long-term stability. This work presents a novel and feasible strategy for constructing hierarchical heterostructured electrocatalysts that enable efficient water electrolysis. By combining rational design and theoretical guidance, our approach offers promising prospects for advancing the field of electrocatalysis and facilitating sustainable energy conversion.

Highly Effective H2/D2 Separation within the Stable Cu(I)Cu(II)-BTC: The Effect of Cu(I) Structure on Quantum Sieving.

Realizing ideal deuterium separation from isotopic mixtures remains a daunting challenge because of their almost identical sizes, shapes, and physicochemical properties. Using the quantum sieving effect in porous materials with suitable pore size and open metal sites (OMSs) enables efficient hydrogen isotope separation. Herein, synthetic HKUST-1-derived microporous mixed-valence Cu(I)Cu(II)-BTC (BTC = benzene-1,3,5-tricarboxylate), featuring a unique network of distinct Cu(I) and Cu(II) coordination sites, can remarkably boost the D2/H2 isotope separation, which has a high selectivity (SD2/H2) of 37.9 at 30 K, in comparison with HKUST-1 and other porous materials. Density functional theory (DFT) calculations indicate that the introduction of Cu(I) macrocycles in the framework decreases the pore size and further leads to relatively enhanced interaction of H2/D2 molecules on Cu(II) sites. The significantly enhanced selectivity of Cu(I)Cu(II)-BTC at 30 K can be mainly attributed to the synergistic effect of kinetic quantum sieving (KQS) and chemical affinity quantum sieving (CAQS). The results reveal that Cu(I) OMSs exhibit counterintuitive behaviors and play a crucial role in tuning quantum sieving without a complex structural design, which provides a deeper insight into quantum sieving mechanisms and a new strategy for the intelligent design of highly efficient isotope systems.

miRNA-150-5p associate with antihypertensive effect of epigallocatechin-3-gallate revealed by aorta miRNome analysis of spontaneously hypertensive rat.

AIMS: The antihypertensive mechanism (s) of the epigallocatechin-3-gallate (EGCG), a major effective component in green tea, might associate with microRNAs (miRNAs). Here, we aimed to investigate which microRNA in aorta of spontaneously hypertensive rats (SHRs) were modulated by administration of EGCG and its mechanism. MAIN METHODS: The pharmacokinetic behaviors of EGCG and epigallocatechin (EGC) in Sprague-Dawley rats were analyzed by HPLC and DRUG AND STATISTICS software. Blood pressure of SHRs was monitored by the tail-cuff method, the miRNomes of aorta from SHRs was analyzed with deep sequencing, and expression of hypertension-associated miRNAs with significant change and their host genes and target genes were validated by real-time PCR and Western blot. KEY FINDINGS: The plasma deposition of EGCG and EGC best fitted a mono-compartmental model with maximum plasma concentration post-dose (Cmax, 6.65 vs 4.45 µg/ml) and the corresponding time (Tmax, 15 vs 10 min). Systolic blood pressure (SBP) of SHRs decreased to the lowest point by 34.04 mmHg and recovered by 23.39 mmHg after 15 and 30 min of administration at dose of 300 mg/kg BW EGCG, respectively, and it decreased again at 60 min and recovered at time 2 h. Total 35 upregulated and 18 downregulated miRNAs were identified compared to the control group (p < .01) after EGCG administration. Expression of hypertension-associated miRNA-126a-3p and miRNA-150-5p were further validated. In turn, their host gene and target genes were up-regulated and down-regulated, respectively. SIGNIFICANCE: Our results indicated that miRNA-150-5p might be involved in the antihypertensive effect of EGCG through SP1/AT1R pathway.

P2X7 receptor regulates sympathoexcitatory response in myocardial infarction rats via NF-κB and MAPK pathways.

Previous studies have provided evidence for the regulatory effect of P2X7 receptor (P2X7R) on cardiovascular activities. Our study focused on exploring the function and fundamental mechanism of microglial P2X7R in controlling sympathoexcitatory response using rats with acute myocardial infarction (AMI). Coronary artery ligation was used in rats to cause AMI. And before that, rats were administrated with P2X7R siRNA that targeted P2X7R mRNA into paraventricular nucleus (PVN) or BBG (Brilliant Blue G, a P2X7 receptor antagonist). Increased expression levels of P2X7R and adenosine triphosphate (ATP) were observed in the hypothalamic PVN of AMI rats. Moreover, the knockdown of P2X7R expression by P2X7-siRNA or suppression of P2X7 receptor by BBG attenuated the elevation of both vasopressin and oxytocin levels in the PVNs of AMI rats. There was also a decrease in renal sympathetic nerve activity (RSNA) by P2X7-siRNA and BBG. Besides, inflammation was alleviated by P2X7-siRNA and BBG through suppressing pro-inflammatory cytokines IL-1ß and IL-6 in PVN of AMI rats. Furthermore, blockade of P2X7R moderated the process of cardiac remodeling. This was achieved due to the regulatory effect of P2X7R on sympathoexcitatory response by influencing NF-κB and mitogen-activated protein kinase (MAPK) signaling. These findings suggest that P2X7R can act as a new regulator of sympathoexcitatory response via NF-κB and MAPK signaling pathways in AMI rats.

VPPIPP and IPPVPP: two hexapeptides innovated to exert antihypertensive activity.

In this study, two hexapeptides of IPPVPP and VPPIPP were innovated by using two commercial antihypertensive peptides IPP and VPP as two domains cis-linked and trans-linked, respectively. The IPPVPP and VPPIPP were chemically synthesized and evaluated for the antihypertensive activity in vitro/vivo. The in vitro ACE-inhibitory study showed that VPPIPP (34.71 ± 4.38%) has a significantly stronger activity than that of IPPVPP (13.17 ± 0.25%) at a treatment concentration of 10 µmol/L, but it was weaker than the commercial IPP (56.97 ± 2.40%) (P<0.05). However, VPPIPP, IPPVPP, and IPP lowered the systolic blood pressure by 21 ± 0.9%, 17.4 ± 1.3% and 17.5 ± 0.9%, respectively, in rats at 1.5 mg/kg body weight dosage. The result was consistent with the mRNA level of sarcoplasmic reticulum Ca(2+), Mg(2+) -ATPase Gene (SERCA 2a) in rat hearts. Additionally, VPPIPP and IPPVPP showed no negative impact on blood glycometabolism. The results suggested that the two hexapeptides could be potent bioactive peptides in functional foods for people with high blood pressure.