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1.
Small ; 19(36): e2301609, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37116125

RESUMO

NiFe-based (oxy)hydroxides are the benchmark catalysts for the oxygen evolution reaction (OER) in alkaline medium, however, it is still challenging to control their structures and compositions. Herein, molybdates (NiFe(MoO4 )x ) are applied as unique precursors to synthesize ultrafine Mo modified NiFeOx Hy (oxy)hydroxide nanosheet arrays. The electrochemical activation process enables the molybdate ions (MoO4 2- ) in the precursors gradually dissolve, and at the same time, hydroxide ions (OH- ) in the electrolyte diffuse into the precursor and react with Ni2+ and Fe3+ ions in confined space to produce ultrafine NiFeOx Hy (oxy)hydroxides nanosheets (<10 nm), which are densely arranged into microporous arrays and maintain the rod-like morphology of the precursor. Such dense ultrafine nanosheet arrays produce rich edge planes on the surface of NiFeOx Hy (oxy)hydroxides to expose more active sites. More importantly, the capillary phenomenon of microporous structures and hydrophilic hydroxyl groups induce the superhydrophilicity and the rough surface produces the superaerophobic characteristic for bubbles. With these advantages, the optimized catalyst exhibits excellent performance for OER, with a small overpotential of 182 mV at 10 mA cm-2 and long-term stability (200 h) at 200 mA cm-2 . Theoretical calculations show that the modification of Mo enhances the electron delocalization and optimizes the adsorption of intermediates.

2.
Chemistry ; 29(46): e202301124, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37296528

RESUMO

NiFe-layered double hydroxide (NiFe-LDH) is the benchmark catalyst for the oxygen evolution reaction (OER) in alkaline medium, however, it is still challenging to improve its activity and stability. Herein, NiFe-LDH macroporous array electrodes are demonstrated to significantly enhance the activity and stability for oxygen evolution reaction. The electrodes are fabricated by the chemical and electrochemical corrosion process of Ni foam induced by ferric nitrate, hydrochloric acid and oxygen. By optimizing the amount of iron salt and acid and selecting the appropriate reaction temperature and time, the NiFe-LDH electrodes only need the overpotential of 180 mV and 248 mV to reach the current density of 10 mA cm-2 and 500 mA cm-2 , respectively, and remain highly stable for 1000 h at 500 mA cm-2 . The unique macroporous array not only significantly increases the active area of NiFe-LDH catalyst, but also creates a stable nanostructure that avoids severe reconstruction.

3.
Small ; 18(18): e2107450, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35128790

RESUMO

Electrochemical CO2 reduction to valuable ethylene and ethanol offers a promising strategy to lower CO2 emissions while storing renewable electricity. Cu-based catalysts have shown the potential for CO2 -to-ethylene/ethanol conversion, but still suffer from low activity and selectivity. Herein, the effects of surface and interface structures in Cu-based catalysts for CO2 -to-ethylene/ethanol production are systematically discussed. Both reactions involve three crucial steps: formation of CO intermediate, CC coupling, and hydrodeoxygenation of C2 intermediates. For ethylene, the key step is CC coupling, which can be enhanced by tailoring the surface structures of catalyst such as step sites on facets, Cu0 /Cuδ+ species and nanopores, as well as the optimized molecule-catalyst and electrolyte-catalyst interfaces further promoting the higher ethylene production. While the controllable hydrodeoxygenation of C2 intermediate is important for ethanol, which can be achieved by tuning the stability of oxygenate intermediates through the metallic cluster induced special atomic configuration and bimetallic synergy induced the double active sites on catalyst surface. Additionally, constraining CO coverage by the complex-catalyst interface and stabilizing CO bond by N-doped carbon/Cu interface can also enhance the ethanol selectivity. The structure-performance relationships will provide the guidance for the design of Cu-based catalysts for highly efficient reduction of CO2 .

4.
Small ; 17(23): e2008052, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33887101

RESUMO

Hydrogenation of diesters to diols is a vital process for chemical industry. The inexpensive Cu+ /Cu0 -based catalysts are highly active for the hydrogenation of esters, however, how to efficiently tune the ratio of Cu+ /Cu0 and stabilize the Cu+ is a great challenge. In this work, it is demonstrated that doped Ti ions can tune the ratio of Cu+ /Cu0 and stabilize the Cu+ by the TiOCu bonds in Ti-doped SiO2 supported Cu nanoparticle (Cu/Ti-SiO2 ) catalysts for the high conversion of dimethyl adipate to 1,6-hexanediol. In the synthesis of the catalysts, the Ti4+ OCu2+ bonds promote the reduction of Cu2+ to Cu+ by forming Ti3+ OV Cu+ (OV : oxygen vacancy) bonds and the amount of Ti doping can tune the ratio of Cu+ /Cu0 . In the catalytic reaction, the O vacancy activates CO in the ester by forming new Ti3+ δ OR Cu1+ δ bonds (OR : reactant oxygen), and Cu0 activates hydrogen. After the products are desorbed, the Ti3+ δ OR Cu1+ δ bonds return to the initial state of Ti3+ OV Cu+ bonds. The reversible TiOCu bonds greatly improve the activity and stability of the Cu/Ti-SiO2 catalysts. When the content of Ti is controlled at 0.4 wt%, the conversion and selectivity can reach 100% and 98.8%, respectively, and remain stable for 260 h without performance degradation.

5.
Angew Chem Int Ed Engl ; 60(9): 4747-4755, 2021 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-33215803

RESUMO

A facile anisotropic surface modification and etching strategy is presented for the synthesis of hollow structured ZIF-67 nanoframes. The strategy uses structural and compositional distinctions between each crystallographic facet of truncated rhombic dodecahedrons ZIF-67 (tZIF-67 RDs) and the moderate coordinating and etching effects of cyanuric acid (CA). The CA can anisotropically modify and protect the {110} facets from etching, causing the six {100} facets be selectively etched via an inside-out manner, and finally forming the hollow nanoframes. The surface-modified hollow tZIF-67 RDs can be facet-selectively etched by metal salts in an outside-in manner to give metal-doped tZIF-67 nanoframes. After calcination, the metal-tZIF-67 hybrids are converted into metal-Co alloy/C composite catalysts with hollow nanoframed structures. The PtCo/C catalyst with only 5.9 wt % Pt exhibits high catalytic activities and stabilities in the hydrogen evolution reaction (HER) in acidic solutions.

6.
Chemistry ; 26(28): 6195-6204, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32077175

RESUMO

Developing efficient electrocatalysts for the hydrogen evolution reaction (HER) is crucial for establishing a sustainable and environmentally friendly energy system, but it is still a challenging issue. Herein, hierarchical tubular-structured CoS2 -MoS2 /C as efficient electrocatalysts are fabricated through a unique metal-organic framework (MOF) mediated self-sacrificial templating. Core-shell structured MoO3 @ZIF-67 nanorods are used both as a precursor and a sacrificial template to form the one-dimensional tubular heterostructure where vertically aligned two-dimensional CoS2 -MoS2 nanosheets are formed on the MOF-derived carbon tube. Trace amounts of noble metals (Pd, Rh, and Ru) are successfully introduced to enhance the electrocatalytic property of the CoS2 -MoS2 /C nanocomposites. The as-synthesized hierarchical tubular heterostructures exhibit excellent HER catalytic performance owing to the merits of the hierarchical hollow architecture with abundantly exposed edges and the uniformly dispersed active sites. Impressively, the optimal Pd-CoS2 -MoS2 /C-600 catalyst delivers a current density of 10 mA cm-2 at a low overpotential of 144 mV and a small Tafel slope of 59.9 mV/dec in 0.5 m H2 SO4 . Overall, this MOF-mediated strategy can be extended to the rational design and synthesis of other hollow heterogeneous catalysts for scalable hydrogen generation.

7.
Angew Chem Int Ed Engl ; 57(20): 5848-5852, 2018 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-29656420

RESUMO

The redox units of polyaniline (PAni) are used cooperatively, and in situ, to assemble ruthenium (Ru) nanoclusters in a hierarchically ordered carbon electrode. The oxidized quinonoid imine (QI) units in PAni bond Ru complex ions selectively, whereas reduced benzenoid amine (BA) units cannot. By electrochemically tuning the ratio of QI to BA, Ru complexes are spatially confined in the outer layer of hierarchical PAni frameworks. Carbonization of Ru-PAni hybrids induces nucleation on the outer surface of the carbon support, generating nearly monodisperse Ru nanoclusters. The optimized catalyst has a low loading of approximately 2 wt % Ru, but exhibits a mass activity for the hydrogen evolution reaction that is about 6.8 times better than commercial 20 wt % Pt/C catalyst.

8.
Angew Chem Int Ed Engl ; 56(43): 13508-13512, 2017 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-28941047

RESUMO

Mesoporous cobalt phosphide (meso-CoP) was prepared by the phosphorization of ordered mesoporous cobalt oxide (meso-Co3 O4 ). The electrical conductivity of meso-CoP is 37 times higher than that of nonporous CoP, and it displays semimetallic behavior with a negligibly small activation energy of 26 meV at temperatures below 296 K. Above this temperature, only materials with mesopores underwent a change in conductivity from semimetallic to semiconducting behavior. These properties were attributed to the coexistence of nanocrystalline Co2 P phases. The poor crystallinity of mesoporous materials has often been considered to be a problem but this example clearly shows its positive aspects. The concept introduced here should thus lead to new routes for the synthesis of materials with high electronic conductivity.

9.
J Am Chem Soc ; 137(48): 15070-3, 2015 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-26555852

RESUMO

Development of an efficient hydrogen evolution reaction (HER) catalyst composed of earth-abundant elements is scientifically and technologically important for the water splitting associated with the conversion and storage of renewable energy. Herein we report a new class of Co-C-N complex bonded carbon (only 0.22 at% Co) for HER with a self-supported and three-dimensional porous structure that shows an unexpected catalytic activity with low overpotential (212 mV at 100 mA cm(-2)) and long-term stability, better than that of most traditional-metal catalysts. Experimental observations in combination with density functional theory calculations reveal that C and N hybrid coordination optimizes the charge distribution and enhances the electron transfer, which synergistically promotes the proton adsorption and reduction kinetics.

10.
Chem Soc Rev ; 43(22): 7746-86, 2014 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-24056780

RESUMO

With the development of renewable energy and electrified transportation, electrochemical energy storage will be more important in the future than it has ever been in the past. Although lithium-ion batteries (LIBs) are traditionally considered to be the most likeliest candidate thanks to their relatively long cycle life and high energy efficiency, their limited energy density as well as cost are still causing a bottleneck for their long-term application. Alternatively, metal-air batteries have been proposed as a very promising large-scale electricity storage technology with the replacement of the intercalation reaction mechanism by the catalytic redox reaction of a light weight metal-oxygen couple. Generally, based on the electrolyte, these metal-air batteries can be divided into aqueous and nonaqueous systems, corresponding to two typical batteries of Zn-air and Li-air, respectively. The prominent feature of both batteries are their extremely high theoretical energy density, especially for nonaqueous Li-air batteries, which far exceeds the best that can be achieved with LIBs. In this review, we focus on the major obstacle of sluggish kinetics of the cathode in both batteries, and summarize the fundamentals and recent advances related to the oxygen catalyst materials. According to the electrolyte, the aqueous and nonaqueous electrocatalytic mechanisms of the oxygen reduction and evolution reactions are discussed. Subsequently, seven groups of oxygen catalysts, which have played catalytic roles in both systems, are selectively reviewed, including transition metal oxides (single-metal oxides and mixed-metal oxides), functional carbon materials (nanostructured carbons and doped carbons), metal oxide-nanocarbon hybrid materials, metal-nitrogen complexes (non-pyrolyzed and pyrolyzed), transition metal nitrides, conductive polymers, and precious metals (alloys). Nonaqueous systems have the advantages of energy density and rechargeability over aqueous systems and have gradually become the research focus of metal-air batteries. However, there are considerable challenges beyond catalysts from aqueous to nonaqueous electrolytes, which are also discussed in this review. Finally, several future research directions are proposed based on the results achieved in this field, with emphasis on nonaqueous Li-air batteries.

11.
Angew Chem Int Ed Engl ; 54(36): 10530-4, 2015 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-26218453

RESUMO

Identifying effective means to improve the electrochemical performance of oxygen-evolution catalysts represents a significant challenge in several emerging renewable energy technologies. Herein, we consider metal-nitrogen-carbon sheets which are commonly used for catalyzing the oxygen-reduction reaction (ORR), as the support to load NiO nanoparticles for the oxygen-evolution reaction (OER). FeNC sheets, as the advanced supports, synergistically promote the NiO nanocatalysts to exhibit superior performance in alkaline media, which is confirmed by experimental observations and density functional theory (DFT) calculations. Our findings show the advantages in considering the support effect for designing highly active, durable, and cost-effective OER electrocatalysts.

12.
Front Nutr ; 11: 1367086, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38606018

RESUMO

Background: Alzheimer's disease (AD) is an age-related neurodegenerative disorder with no effective interventions for curing or modifying its progression. However, emerging research suggests that vitamin A in the diet may play a role in both the prevention and treatment of AD, although the exact mechanisms are not fully understood. Objectives: This study aims to investigate the dietary vitamin A modifies the gut microbiota and intestinal tissue transcriptome, impacting intestinal permeability and the release of inflammatory factors, thereby influencing Aß pathology shedding light on its potential as a dietary intervention for AD prevention and treatment. Methods: The APP/PS1-AD mouse model was employed and divided into three dietary groups: vitamin A-deficient (VAD), normal vitamin A (VAN), and vitamin A-supplemented (VAS) for a 12-week study. Neurobehavioral functions were assessed using the Morris Water Maze Test (MWM). Enzyme-linked immunosorbent assay (ELISA) was used to quantify levels of Diamine Oxidase (DAO), D-lactate, IL-6, IL-1ß, and TNF-a cytokines. Serum vitamin A levels were analyzed via LC-MS/MS analysis. Immunohistochemical analysis and morphometry were performed to evaluate the deposition of Aß in brain tissue. The gut microbiota of APP/PS1 mice was analyzed using 16S rRNA sequencing analysis. Additionally, transcriptomic analysis was conducted on intestinal tissue from APP/PS1 mice. Results: No significant changes in food intake and body weight were observed among the groups. However, the VAD and VAS groups showed reduced food intake compared to the VAN group at various time points. In terms of cognitive function, the VAN group performed better in the Morris Water Maze Test, indicating superior learning and memory abilities. The VAD and VAS groups exhibited impaired performance, with the VAS group performing relatively better than the VAD group. Serum vitamin A concentrations differed significantly among the groups, with the VAS group having the highest concentration. Aß levels were significantly higher in the VAD group compared to both the VAN and VAS groups. Microbial analysis revealed that the VAS and VAN groups had higher microbial diversity than the VAD group, with specific taxa characterizing each group. The VAN group was characterized by taxa such as Actinohacteriota and Desulfovibrionaceae, while the VAD group was characterized by Parabacteroides and Tannerellaceae. The VAS group showed similarities with both VAN and VAD groups, with taxa like Desulfobacterota and Desulfovibrionaceae being present. The VAD vs. VAS, VAD vs. VAN, and VAS vs. VAN comparisons identified 571, 313, and 243 differentially expressed genes, respectively, which associated with cellular and metabolic processes, and pathway analysis revealed enrichment in pathways related to chemical carcinogenesis, drug metabolism, glutathione metabolism, and immune-related processes. The VAD group exhibited higher levels of D-lactate, diamine oxidase, and inflammatory cytokines (TNF-a, IL-1ß, IL-6) compared to the VAN and VAS groups. Conclusion: Dietary vitamin A supplementation modulates the gut microbiota, intestinal permeability, inflammatory factors, and Aß protein formation, offering insights into the pathogenesis of AD and potential therapeutic avenues for further exploration. This research highlights the intricate interplay between diet, gut microbiota, and neurodegenerative processes, emphasizing the importance of dietary interventions in managing AD-related pathologies.

13.
J Colloid Interface Sci ; 661: 966-976, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38330668

RESUMO

The Cu0-Cu+ interfaces play a key role in the electrochemical CO2 reduction reaction (CO2RR) to produce multi-carbon products (C2+), however, it is difficult for Cu+ to exist stably under reducing conditions. Herein, we construct highly dispersed and stable Cu-Cu2O-CeOx interface on reduced graphene oxide (rGO) for CO2 electroreduction to C2+ products. During the synthesis process, utilizing strong electrostatic interactions, the complex ions of Cu2+ and Ce3+ are uniformly adsorbed on the surface of graphene oxide. Then, under the solvothermal reaction of ethylene glycol and thiourea, the two metal complex ions are converted into highly dispersed and ultrafine Cu2S-CeOx nanocomposites on rGO. Interestingly, CeOx and thiourea synergistically regulate the generation of only Cu+. Under the CO2RR process, the reconstruction of Cu2S promotes the formation of Cu0 and Cu2O species. CeOx stabilizes partial Cu+ species and promotes the formation of Cu-Cu2O-CeOx composite interface. With the help of synergistic effect of Cu0, Cu+ and CeOx, the optimized reaction interface achieves the Faradaic efficiency (FE) of 74.5 % for C2+ products with the current density of 230 mA cm-2 at -0.9 V versus the reversible hydrogen electrode. In situ attenuate total reflectance-infrared absorption spectroscopy (ATR-IRAS) spectra show that the composite interfaces promote the adsorption and activation of H2O and CO2, improve the surface coverage of CO intermediates (*CO), and thus accelerate the CC coupling process.

14.
Mol Pharmacol ; 83(2): 389-98, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23160941

RESUMO

The evolutionary relationship and functional correlation between human formyl peptide receptors (FPRs) and their mouse counterparts remain incompletely understood. We examined three members of the mouse formyl peptide receptor subfamily (mFprs) and found that they differ in agonist preference and cellular distributions. When stably expressed in transfected rat basophilic leukemia (RBL-2H3) cells, mFpr1 was readily activated by N-formylated peptides derived from Listeria monocytogenes (fMIVTLF), Staphylococcus aureus (fMIFL), and mitochondria (fMMYALF). In contrast, the Escherichia coli-derived fMLF was 1000-fold less potent. The aforementioned peptides were much less efficacious at mFpr2, which responded better to the synthetic hexapeptide WKYMVm, the synthetic agonists Quin-C1 (a substituted quinazolinone), and compound 43 (a nitrosylated pyrazolone derivative). Saturation binding assays showed that mFpr1 and mFpr2 were expressed at similar levels on the cell surface, although their affinity for N-formyl-Met-Leu-Phe-Ile-Ile-Lys-fluorescein isothiocyanate varied by more than 1000-fold [dissociation constant (K(d)) values of 2.8 nM for mFpr1 and 4.8 µM for mFpr2]). Contrary to these receptors, mFpr-rs1 responded poorly to all the previously mentioned peptides that were tested. Fluorescent microscopy revealed an intracellular distribution pattern of mFpr-rs1. On the basis of these results, we conclude that mFpr1 is an ortholog of human FPR1 with certain pharmacologic properties of human FPR2/ALX, whereas mFpr2 has much lower affinity for formyl peptides. The intracellular distribution of mFpr-rs1 suggests an evolutionary correlation with human FPR3.


Assuntos
N-Formilmetionina Leucil-Fenilalanina/metabolismo , Receptores de Formil Peptídeo/metabolismo , Animais , Benzamidas/farmacologia , Cálcio/metabolismo , Linhagem Celular Tumoral , Escherichia coli/metabolismo , Leucemia Basofílica Aguda/metabolismo , Listeria monocytogenes/metabolismo , Camundongos , Mitocôndrias/metabolismo , Oligopeptídeos/farmacologia , Ligação Proteica , Quinazolinas/farmacologia , Ratos , Staphylococcus aureus/metabolismo , Transfecção/métodos
15.
Chem Sci ; 14(13): 3400-3414, 2023 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-37006690

RESUMO

Nickel-molybdenum (Ni-Mo) alloys are promising non-noble metal electrocatalysts for the hydrogen evolution reaction (HER) in alkaline water; however, the kinetic origins of their catalytic activities still remain under debate. In this perspective, we systematically summarize the structural characteristics of Ni-Mo-based electrocatalysts recently reported and find that highly active catalysts generally have alloy-oxide or alloy-hydroxide interface structures. Based on the two-step reaction mechanism under alkaline conditions, water dissociation to form adsorbed hydrogen and combination of adsorbed hydrogen into molecular hydrogen, we discuss in detail the relationship between the two types of interface structures obtained by different synthesis methods and their HER performance in Ni-Mo based catalysts. For the alloy-oxide interfaces, the Ni4Mo/MoO x composites produced by electrodeposition or hydrothermal combined with thermal reduction exhibit activities close to that of platinum. For only the alloy or oxide, their activities are significantly lower than that of composite structures, indicating the synergistic catalytic effect of binary components. For the alloy-hydroxide interfaces, the activity of the Ni x Mo y alloy with different Ni/Mo ratios is greatly improved by constructing heterostructures with hydroxides such as Ni(OH)2 or Co(OH)2. In particular, pure alloys obtained by metallurgy must be activated to produce a layer of mixed Ni(OH)2 and MoO x on the surface to achieve high activity. Therefore, the activity of Ni-Mo catalysts probably originates from the interfaces of alloy-oxide or alloy-hydroxide, in which the oxide or hydroxide promotes water dissociation and the alloy accelerates hydrogen combination. These new understandings will provide valuable guidance for the further exploration of advanced HER electrocatalysts.

16.
Chin Med ; 18(1): 140, 2023 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-37904166

RESUMO

BACKGROUND: More efficient instruments for body constitution identification are needed for clinical practice. We aimed to develop the short-form version of the Constitution in Chinese Medicine Questionnaire (CCMQ) and evaluate for health management. METHODS: First, the short forms were developed through expert survey, classical test theory (CTT), and modern item response (IRT) based on the CCMQ. A combination of e-mail and manual methods was used in expert survey. Then, five indexes of CTT including criteria value-critical ratio, correlation coefficient, discrete tendency, internal consistency, and factor loading were used. And, IRT method was used through analyzing the discrimination and difficulty parameters of items. Second, the three top-ranked items of each constitution scale were selected for the simplified CCMQ, based on the three combined methods of different conditions and weights. Third, The psychometric properties such as completion time, validity (Construct, criterion, and divergent validity), and reliability (test-retest and internal consistency reliability) were evaluated. Finally, the diagnostic validity of the best short-form used receiver operating characteristic (ROC) curve. RESULTS: Three short-form editions were developed, and retained items 27, 23 and 27, which are named as WangQi nine body constitution questionnaire of Traditional Chinese Medicine (short-form) (SF-WQ9CCMQ)- A, B, and C, respectively. SF-WQ9CCMQ- A is showed the best psychometric property on Construct validity, Criterion validity, test-retest reliability and internal consistency reliability. The diagnostic validity indicated that the area under the ROC curve was 0.928 (95%CI: 0.924-0.932) for the Gentleness constitution scale, and were 0.895-0.969 and 0.911-0.981 for unbalance constitution scales using the cut-off value of the original CCMQ as 40 ("yes" standard) and 30 ("tendency" standard), respectively. CONCLUSIONS: Our study successfully developed a well short-form which has good psychometric property, and excellent diagnostic validity consistent with the original. New and simplified instrument and opportunity are provided for body constitution identification, health management and primary care implementation.

17.
ACS Nano ; 16(12): 20851-20864, 2022 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-36458840

RESUMO

The application scope of metal-organic frameworks (MOFs) can be extended by rationally designing the architecture and components of MOFs, which can be achieved via a metal-containing solid templated strategy. However, this strategy suffers from low efficiency and provides only one specific MOF from one template. Herein, we present a versatile templated strategy in which organic ligands are weaved into hydrogen-bonded organic frameworks (HOFs) for the controllable and scalable synthesis of MOF nanotubes. HOF nanowires assembled from benzene-1,3,5-tricarboxylic acid and melamine via a simple sonochemical approach serve as both the template and precursor to produce MOF nanotubes with varied metal compositions. Hybrid nanotubes containing nanometal crystals and N-doped graphene prepared through a carbonization process show that the optimized NiRuIr alloy@NG nanotube exhibits excellent electrocatalytic HER activity and durability in alkaline media, outperforming most reported catalysts. The strategy proposed here demonstrates a pioneering study of combination of HOF and MOF, which shows great potential in the design of other nanosized MOFs with various architectures and compositions for potential applications.

18.
Naunyn Schmiedebergs Arch Pharmacol ; 395(8): 945-962, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35476142

RESUMO

Recently, hypoglycemic drugs belonging to sodium-glucose cotransporter 2 inhibitors (SGLT2i) have generated significant interest due to their clear cardiovascular benefits for heart failure with preserved ejection fraction (HFpEF) since there are no effective drugs that may improve clinical outcomes for these patients over a prolonged period. But, the underlying mechanisms remain unclear, particularly its effects on ferroptosis, a newly defined mechanism of iron-dependent non-apoptotic cell death during heart failure (HF). Here, with proteomics, we demonstrated that ferroptosis might be a key mechanism in a rat model of high-salt diet-induced HFpEF, characterized by iron overloading and lipid peroxidation, which was blocked following treatment with canagliflozin. Data are available via ProteomeXchange with identifier PXD029031. The ferroptosis was evaluated with the levels of acyl-CoA synthetase long-chain family member 4, glutathione peroxidase 4, ferritin heavy chain 1, transferrin receptor, Ferroportin 1, iron, glutathione, malondialdehyde, and 4-hydroxy-trans-2-nonenal. These findings highlight the fact that targeting ferroptosis may serve as a cardioprotective strategy for HFpEF prevention and suggest that canagliflozin may exert its cardiovascular benefits partly via its mitigation of ferroptosis.


Assuntos
Ferroptose , Insuficiência Cardíaca , Animais , Canagliflozina/farmacologia , Canagliflozina/uso terapêutico , Insuficiência Cardíaca/tratamento farmacológico , Ferro/metabolismo , Ratos , Volume Sistólico
19.
J Colloid Interface Sci ; 582(Pt A): 322-332, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-32827957

RESUMO

Electrochemical water oxidation is one of the thrust areas of research today in solving energy and environmental issues. The morphological control in the synthesis of nanomaterials plays a crucial role in designing efficient electrocatalyst. In general, various synthetic parameters can direct the morphology of nanomaterials and often this is the main driving force for the electrocatalyst in tuning the rate of the oxygen evolution reaction (OER) for the electrochemical water-splitting. Here, a facile and cost-effective synthesis of spinel cobalt oxides (Co3O4) via a one-pot hydrothermal pathway with tunable morphology has been demonstrated. Different kinds of morphologies have been obtained by systematically varying the reaction time i.e. nanospheres, hexagon and nanocubes. Their catalytic activity has been explored towards OER in 1.0 M alkaline KOH solution. The catalyst Co3O4-24 h nanoparticles synthesized in 24 h reaction time shows the lowest overpotential (η) value of 296 mV at 10 mA cm-2 current density, in comparison to that of other as-prepared catalysts i.e. Co3O4-pH9 (311 mV), Co3O4-12 h (337 mV), and Co3O4-6 h (342 mV) with reference to commercially available IrO2 (415 mV). Moreover, Co3O4-24 h sample shows the outstanding electrochemical stability up to 25 h time.

20.
Sheng Li Xue Bao ; 62(6): 489-94, 2010 Dec 25.
Artigo em Chinês | MEDLINE | ID: mdl-21170493

RESUMO

With the deepening research on pathogenesis of depression, the focus has diverted from the mechanism of regulating monoamines to the basic pathophysiology of depression and the long-term mechanism of antidepressant treatments. cAMP response element binding protein (CREB) in the brain, especially in the hippocampi, as a converging agent of many intracellular signaling transduction pathways is getting increasing attention. To better understand the basic pathophysiology of depression and the long-term mechanism of antidepressant treatments, it is significant to make clear the correlation between hippocampal CREB and antidepressant treatments. This review mainly refers to the formation of CREB and its distribution in hippocampi, the upstream signaling transduction pathways of hippocampal CREB and antidepressant treatments, and the possible antidepressant mechanisms by regulating hippocampal CREB.


Assuntos
Antidepressivos/uso terapêutico , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Depressão/tratamento farmacológico , Depressão/fisiopatologia , Hipocampo/metabolismo , Animais , Hipocampo/efeitos dos fármacos , Humanos , Transdução de Sinais
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