Abstract
Developing active single-atom-catalyst (SAC) for alkaline hydrogen evolution reaction (HER) is a promising solution to lower the green hydrogen cost. However, the correlations are not clear ...between the chemical environments around the active-sites and their desired catalytic activity. Here we study a group of SACs prepared by anchoring platinum atoms on NiFe-layered-double-hydroxide. While maintaining the homogeneity of the Pt-SACs, various axial ligands (−F, −Cl, −Br, −I, −OH) are employed
via
a facile irradiation-impregnation procedure, enabling us to discover definite chemical-environments/performance correlations. Owing to its high first-electron-affinity, chloride chelated Pt-SAC exhibits optimized bindings with hydrogen and hydroxide, which favor the sluggish water dissociation and further promote the alkaline HER. Specifically, it shows high mass-activity of 30.6 A mgPt
−1
and turnover frequency of 30.3 H
2
s
−1
at 100 mV overpotential, which are significantly higher than those of the state-of-the-art Pt-SACs and commercial Pt/C catalyst. Moreover, high energy efficiency of 80% is obtained for the alkaline water electrolyser assembled using the above catalyst under practical-relevant conditions.
Electrochemical oxidation of 5-hydroxymethylfurfural (HMF) has shown promising prospects in producing highly valuable chemicals. Herein, we report the synthesis of ultrasmall Ag nanoclusters anchored ...on NiCo-layered double hydroxide (NiCo-LDH) nanosheet arrays (Ag
n
@NiCo-LDH)
via
a facile electrodeposition strategy. The prepared Ag
n
@NiCo-LDH nanosheet arrays exhibit excellent electrocatalytic HMF oxidation performance with a current density of 10 mA cm
−2
at 1.29 V
RHE
and the Faraday efficiency of nearly 100% for 2,5-furandicarboxylic acid production. This study offers an effective approach to rationally design nanoclusters to achieve high catalytic activity for sustainable energy conversion and production.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
To investigate the effect of Irbesartan on the changes of myocardial advanced glycation end products and their receptor (AGEs-RAGE), and matrix metalloproteinases (MMPs) systems in rat type 2 ...diabetes myocardial fibrosis model. All male Sprague-Dwaley rats were randomly divided into four groups: control (CON), high glucose and high-caloric diet (HC), type 2 diabetes (T2DM) and Irbesartan + T2DM (Ir+T2DM) groups. At 12th week, the fasting blood glucose (FBG) and fasting serum insulin (FINS) levels, insulin resistance index (IRI), insulin sensitivity index (ISI), body weight (BW), the ratio of heart weight/body weight (H/B), left ventricular weight index (LVWI), and cardiac col I, col III contents, plasma MMP-2, MMP-9 levels were evaluated. The protein expressions of col I, AGE, RAGE, MMP-2, MMP-14, and TIMP-2 were analyzed by Western blot. In the T2DM group, FBG, H/B, LVWI, IRI were increased (P < 0.01), while FINS, BW, ISI were decreased in contrast to the CON and HC groups (P < 0.05–0.01). In the Ir+ T2DM group, BW was higher, IRI, H/B, LVWI were lower than in the T2DM group. Compared with the CON and HC groups, the contents of col I and col III, the protein expressions of col I, AGE, RAGE, TIMP-2 and MMP-14 were increased, MMP-2 protein expression, the ratios of MMP-2/TIMP-2 and MMP-14/TIMP-2, MMP-2, and MMP-9 levels were decreased in the T2DM group (P < 0.01). After Irbesartan treatment, all parameters were reversed. Irbesartan can ameliorate myocardial fibrosis in type 2 diabetes rat model, the likely mechanisms may be related to the down-regulation of AGEs-RAGE system and changes of MMPs pathway.
Impact statement
There are about 425 million diabetes patients (20–79 years) in the world according to the International Diabetes Federation Diabetes Atlas – 8th Edition. The cardiovascular complication is one of the major causes of death in diabetes patients. Myocardial fibrosis is one of the serious pathological changes, so investigating the pathogenesis of myocardial fibrosis has the significant value. Our study aims to investigate the effect of Irbesartan (the angiotensin II receptor antagonist) on the changes of AGE-RAGE system and MMP family components, and analyzes the potential mechanisms in type 2 diabetes-induced myocardial fibrosis. Our results provide the theoretical base for better understanding the pathogenesis in type 2 diabetes-induced myocardial complication. It is useful for clinicians to select the effective therapeutic measures for treatment of type 2 diabetes-induced organ fibrosis.
Single‐atom catalysts (SACs) with rationally designed microenvironments (defined as coordination environments and electronic configurations) show superior catalytic activity, selectivity, and ...stability in a majority of reactions. However, the construction of isolated SACs with definite microenvironments to understand the microenvironment–activity relationship is still challenging. Herein, a facile strategy is developed to construct a series of Ru SACs with tunable geometric and electronic structures by employing NiFe‐layered double hydroxides (LDH) with different cation vacancies (MII or MIII) as supports. Detailed spectroscopic characterizations and theoretical calculations reveal that the Ru‐O coordination environments and electronic configurations of single‐atomic Ru can be easily tailored by the vacancy regulation. As a result, isolated Ru atoms anchored by MIII vacancies (denoted as Ru1/LDH‐VIII) with Ru‐O‐Ni coordination environments facilitate the desorption of benzaldehyde, thus leading to higher efficiency of benzyl alcohol oxidation with a superior turnover frequency of 1331 h−1.
A facile strategy is developed to construct Ru SACs with tunable microenvironments by employing NiFe‐LDH with different cation vacancies as supports. The Ru‐O coordination environments and electronic configurations of Ru1 can be easily tailored by the vacancy regulation. Hence, isolated Ru atoms anchored by MIII vacancies facilitate the desorption of benzaldehyde, thus leading to higher efficiency of benzyl alcohol oxidation.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Developing efficient nanozymes to mimic natural enzymes for scavenging reactive radicals remains a significant challenge owing to the insufficient activity of conventional nanozymes. Herein, we ...report a novel Ru single-atom nanozyme (SAE), featuring atomically dispersed Ru atoms on a biocompatible MgAl-layered double hydroxide (Ru
/LDH). The prepared Ru
/LDH SAE shows high intrinsic peroxidase (POD)-like catalytic activity, which outperforms the Ru nanoclusters (NCs) nanozyme by a factor of 20 and surpasses most SAEs. The density functional theory calculations reveal that the high intrinsic POD-like activity of Ru
/LDH can be attributed to a heterolytic path of H
O
dissociation on the single Ru sites, which requires lower free energy (0.43 eV) compared to the homolytic path dissociation on Ru NC (0.63 eV). In addition, the Ru
/LDH SAE shows excellent multiple free radicals scavenging ability, including superoxide anion radical (O
⋅
), hydroxyl radical (⋅OH), nitric oxide radical (NO⋅) and 2, 2-diphenyl-1-picrylhydrazyl radical (DPPH⋅). Given the advantages of Ru
/LDH with high enzymatic activities, biosafety, and ease to scale up, it paves the way for exploring SAEs in the practical biological immunity system.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Abstract The exploitation of effective and nontoxic materials with antioxidant activity to mitigate or inhibit the damage caused by elevated levels of free radicals has attracted considerable ...attention across diverse fields. Herein, this study demonstrates that a biocompatible MgAl‐layered double hydroxide (LDH) can be activated for multiple types of free radical scavenging with unexpected activity through amorphization (a‐MgAl‐LDH). Detailed characterization reveals that numerous oxygen defects are introduced after amorphization. Mechanistic studies and theoretical simulations indicate that amorphization‐induced oxygen defects in a‐MgAl‐LDH promote radical adsorption and reduce the reaction energy barriers, thereby resulting in enhanced radical scavenging activities. Consequently, a‐MgAl‐LDH demonstrated remarkable efficiency in mitigating the oxidative injury induced by Rosup in cells and provided thermal stabilization of polyvinyl chloride against degradation. This study demonstrates the transformation of inert MgAl‐LDH into a promising, nontoxic, and cost‐effective nano‐antioxidant option for antioxidative therapy or polymer stabilization and highlights the significance of crystallinity engineering of nanomaterials for efficient free radical scavenging.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Modulating the electronic metal‐support interaction (EMSI) of the single‐atomic sites against leaching via microenvironment regulation is critical to achieving high activity and stability but remains ...challenging. Herein, this work selectively confines Pt single atoms on CoFe layered double hydroxide (LDH) by three oxygen atoms around cation vacancy (Pt1/LDHV) or one oxygen atom at the regular surface (Pt1/LDH) via cation vacancy engineering. By characterizing the structural evolution of the obtained catalysts before and after vacancy construction and single‐atom anchoring, this work demonstrates how the microenvironments modulate the EMSI and the catalytic performance. Theoretical simulations further reveal a significantly enhanced EMSI effect by the three‐coordinated Pt1 atoms on cation vacancies in Pt1/LDHV, which endows a more prominent anti‐leaching feature than the one‐coordinated ones on the regular surface. As a result, the Pt1/LDHV catalyst shows exceptional performance in anti‐Markovnikov alkene hydrosilylation, with a turnover frequency of 1.3 × 105 h−1. More importantly, the enhanced EMSI of Pt1/LDHV effectively prevented the leaching of Pt atom from the catalyst surface and can be recycled at least ten times with only a 3.4% loss of catalytic efficiency with minimal Pt leaching, and reach a high turnover number of 1.0 × 106.
Pt single‐atom catalysts (SACs) with different microenvironments have been implemented by introducing cation vacancies into CoFe‐Layered double hydroxide (LDH). Compared with Pt anchored on the surface of CoFe‐LDH, Pt anchored on cobalt vacancies exhibits stronger electronic metal‐support interaction between the Pt atoms and the oxide atoms of CoFe‐LDH, which result in a superior activity and stability in the hydrosilylation.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Abstract
Developing efficient nanozymes to mimic natural enzymes for scavenging reactive radicals remains a significant challenge owing to the insufficient activity of conventional nanozymes. Herein, ...we report a novel Ru single‐atom nanozyme (SAE), featuring atomically dispersed Ru atoms on a biocompatible MgAl‐layered double hydroxide (Ru
1
/LDH). The prepared Ru
1
/LDH SAE shows high intrinsic peroxidase (POD)‐like catalytic activity, which outperforms the Ru nanoclusters (NCs) nanozyme by a factor of 20 and surpasses most SAEs. The density functional theory calculations reveal that the high intrinsic POD‐like activity of Ru
1
/LDH can be attributed to a heterolytic path of H
2
O
2
dissociation on the single Ru sites, which requires lower free energy (0.43 eV) compared to the homolytic path dissociation on Ru NC (0.63 eV). In addition, the Ru
1
/LDH SAE shows excellent multiple free radicals scavenging ability, including superoxide anion radical (O
2
⋅
−
), hydroxyl radical (⋅OH), nitric oxide radical (NO⋅) and 2, 2‐diphenyl‐1‐picrylhydrazyl radical (DPPH⋅). Given the advantages of Ru
1
/LDH with high enzymatic activities, biosafety, and ease to scale up, it paves the way for exploring SAEs in the practical biological immunity system.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
To investigate the therapeutic mechanism of resveratrol (RES) for Alzheimer's disease (AD) in light of network pharmacology.
We searched PubChem, BATMAN-TCM, Genecards, AD, TTD, String 11.0, AlzData, ...SwissTargetPrediction, Metascape and other databases for the therapeutic targets of RES and human AD-related targets. The intersection was determined using Venny 2.1 to obtain the therapeutic targets of RES for AD. The protein-protein interaction (PPI) network was constructed, the gene ontology (GO) was enriched and the Kyoto Encyclopedia of Genes and Genomes pathway (KEGG pathway) were analyzed. Cytoscape 3.7.1 software was used to construct a target-signaling pathway network of RES in the treatment of AD. Molecular docking verification was carried out on SwissDock (http://www.swissdock.ch/docking). We examined a 293Tau cell model of AD for changes in protein levels of pS396, pS199, Tau5, CDK5, glycogen synthase kinase 3β (GSK3β) and p-GSK3β in response to RES treatment using Western blotting.
We obtained 182 ta
PDF
