Efficient bifunctional electrocatalysts for hydrogen and oxygen evolution reactions are key to water electrolysis. Herein, we report a built‐in electric field (BEF) strategy to fabricate ...heterogeneous nickel phosphide‐cobalt nanowire arrays grown on carbon fiber paper (Ni2P‐CoCH/CFP) with large work function difference (ΔΦ) as bifunctional electrocatalysts for overall water splitting. Impressively, Ni2P‐CoCH/CFP exhibits a remarkable catalytic activity for hydrogen and oxygen evolution reactions to obtain 10 mA cm−2, respectively. Moreover, the assembled lab‐scale electrolyzer driven by an AAA battery delivers excellent stability after 50 h electrocatalysis with a 100 % faradic efficiency. Computational calculations combining with experiments reveal the interface‐induced electric field effect facilitates asymmetrical charge distributions, thereby regulating the adsorption/desorption of the intermediates during reactions. This work offers an avenue to rationally design high‐performance heterogeneous electrocatalysts.
By proposing and fabricating Ni2P‐CoCH heterostructure with large ΔΦ as a model catalyst for overall alkaline water electrolysis, the introduction of a strong built‐in electric field (BEF) is successfully realized to create the asymmetrical charge distributions on catalyst surfaces. The negative charge‐enriched Ni2P and positive charge‐enriched CoCH as active sites separately achieve high hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) activities.
Ultrathin metal–organic framework (MOF) nanosheets (NSs) offer potential for many applications, but the synthetic strategies are largely limited to top‐down, low‐yield exfoliation methods. Herein, ...Ni–M–MOF (M=Fe, Al, Co, Mn, Zn, and Cd) NSs are reported with a thickness of only several atomic layers, prepared by a large‐scale, bottom‐up solvothermal method. The solvent mixture of N,N‐dimethylacetamide and water plays key role in controlling the formation of these two‐dimensional MOF NSs. The MOF NSs can be directly used as efficient electrocatalysts for the oxygen evolution reaction, in which the Ni–Fe–MOF NSs deliver a current density of 10 mA cm−2 at a low overpotential of 221 mV with a small Tafel slope of 56.0 mV dec−1, and exhibit excellent stability for at least 20 h without obvious activity decay. Density functional theory calculations on the energy barriers for OER occurring at different metal sites confirm that Fe is the active site for OER at Ni–Fe–MOF NSs.
Ultrathin, binary MOF nanosheets (NSs) have been successfully prepared for the first time and directly used as efficient oxygen evolution reaction (OER) catalysts. The binary MOF NSs exhibit a highly composition‐dependent OER activity. The optimized Ni–Fe–MOF NSs are highly active and stable towards the OER.
Melatonin is widely involved in plant growth and stress responses as a master regulator. Melatonin treatment alters the levels of endogenous nitric oxide (NO) and NO affects endogenous melatonin ...content. Melatonin and NO may induce various plant physiological behavior through interaction mechanism. However, the interactions between melatonin and NO in plants are largely unknown. The review presented the metabolism of endogenous melatonin and NO and their relationship in plants. The interactions between melatonin and NO in plant growth and development and responses to environmental stress were summarized. The molecular mechanisms of interaction between melatonin and NO in plants were also proposed.
•The IQS was used as corrosion inhibitor for reinforced concrete for the first time.•The IQS presented a superior corrosion inhibition performance in SCPs.•The mechanism is due to its adsorption on ...steel surface, forming a protecting film.
In this study, the corrosion inhibition performance of steel reinforcement in the simulated concrete pore solution containing 3.5wt.% NaCl in the presence of a tailored cationic type of imidazoline quaternary ammonium salt corrosion inhibitor was characterized by electrochemical measurements and surface analysis. The results indicate that the IQS can significantly improve the polarization resistance and pitting potential and reduce the corrosion current density of reinforcement. The main inhibition mechanism is most likely due to the adsorption of the corrosion inhibitor on the steel surface, leading to a reduced corrosion current density of the steel reinforcement.
Increasing population and over-consumption are placing unprecedented demands on agriculture and natural resources. The Earth is suffering from global warning and environmental destruction while our ...agricultural systems are concurrently degrading land, water, biodiversity, and climate on a global scale. For a sustainable future, green certification, e-commerce, and environment education can boost low-carbon economy with decreasing carbon emissions, but very few researches address them for the hotel industry. This research studies the performance impact of e-commerce, international hotel chain, local hotel chain, and green certification for carbon emission reductions of international tourist hotels of Taiwan. It reveals that, after a sufficiently long time, there is an improvement in the environmental and economic performance of the green-certified hotel group. In addition, it reveals that, as recommended by the operation policy, the international hotel chain group together with e-commerce has better performance than local hotel chain. It is also discussed how to sustain the continuing improvement in low-carbon performance of the hotel industry.
•Previous researches about the relations between corporate environmental performance and brand value are controversial.•This research studied for international tourist hotels the environmental and ...economic performance impact by considering at the same time minimized undesired pollution and maximized revenue, which method can be a good business intelligence technique.•It reveals that the luxury hotel group with hotel chains has a significantly better performance than independent operators.•Better environmental performance influences brand value.
Stakeholders are increasingly aware of the potential of environmental performance to benefit their health; however, there is a paucity of sustainability studies addressing the relationship between corporate social responsibility (CSR) performance and the brand equity of hotel chains. Unlike traditional economics that treat undesired outputs such as carbon emissions as costless, this research presents an accurate, concise and clear empirical examination of hotel chain affiliation strategy through the Malmquist-Luenberger index to measure the brand competitiveness of the strategy while considering carbon emissions reduction using objective official panel data from Taiwan. The findings reveal that a group of hotel chains has a significantly higher average energy efficiency and branding value than those of a group of independent operators when holistic carbon emissions reduction is considered. Thus, this study encourages stakeholders to promote green hotel policies to independent hotel operators to achieve a higher brand value with lower carbon emissions and to adopt greater use of business intelligence to assist the decision-making of hotel operators in conformity with the United Nations (UN) Sustainable Development Goals (SDGs).
Regioselective photodimerization of trans‐4‐styrylpyridine (4‐spy) derivatives is performed using pseudorotaxane‐like Zn‐based metal organic frameworks MOFs as templates. The formation of rctt‐HT ...(head‐to‐tail) dimers is achieved by confining pairs of coordinated 4‐spy derivative ligands within hexagonal windows and then irradiating them with UV light. It is also possible to achieve a photodimerization reaction where two different substituted 4‐spy ligands are included in such a MOF material. The ether bond formation is employed to protect the sensitive ‐OH group of HO‐spy and the methyl group of CH3O‐spy is subsequently removed after the formation of cyclobutane derivative in the CH3O‐spy‐based MOF. Introducing substituents at the 2‐ or 3‐position of the phenyl group of 4‐spy does not significantly affect the rate of the dimerization process except in the case of the strongly electron‐withdrawing nitro group where the rate is significantly decreased. These results are in striking contrast to the mixtures of photoproducts and low yields obtained by untemplated photodimerization in organic solvents.
Template synthesis: Pairs of trans‐4‐styrylpyridine or its derivatives are oriented in a parallel and head‐to‐tail (HT) manner for the solid‐state photodimerization within a pseudorotaxane‐like MOF. The high selectivity for the rctt‐HT dimers provides a controlled photodimerization within a confined environment. These results are in striking contrast to the mixtures of products and low yields obtained by untemplated photodimerization in organic solvents.
ABSTRACT
Background
This study aimed to investigate the effect of systemic inflammation, assessed by high sensitivity C‐reactive protein (hs‐CRP) levels, on prediabetes progression and regression in ...middle‐aged and older adults based on the China Health and Retirement Longitudinal Study (CHARLS).
Methods
Participants with prediabetes from CHARLS were followed up 4 years later with blood samples collected for measuring fasting plasma glucose (FPG) and hemoglobin A1c (HbA1c). The level of hs‐CRP was assessed at baseline and categorized into tertiles (low, middle, and high groups). Prediabetes at baseline and follow‐up was defined primarily according to the American Diabetes Association (ADA) criteria. Logistic regression models were used to estimate the odds ratios (ORs) and confidence intervals (CIs). We also performed stratified analyses according to age, gender, BMI, the presence of hypertension, and the disease history of heart disease and dyslipidemia and sensitivity analyses excluding a subset of participants with incomplete data.
Results
Of the 2,874 prediabetes included at baseline, 834 participants remained as having prediabetes, 146 progressed to diabetes, and 1,894 regressed to normoglycemia based on ADA criteria with a 4 year follow‐up. After multivariate logistics regression analysis, prediabetes with middle (0.67–1.62 mg/L) and high (>1.62 mg/L) hs‐CRP levels had an increased incidence of progressing to diabetes compared with prediabetes with low hs‐CRP levels (<0.67 mg/L; OR = 1.846, 95%CI: 1.129–3.018; and OR = 1.632, 95%CI: 0.985–2.703, respectively), and the incidence of regressing to normoglycemia decreased (OR = 0.793, 95%CI: 0.645–0.975; and OR = 0.769, 95%CI: 0.623–0.978, respectively). Stratified analyses and sensitivity analyses showed consistent results.
Conclusions
Low levels of hs‐CRP are associated with a high incidence of regression from prediabetes to normoglycemia and reduced odds of progression to diabetes.
This study found that low levels of hs‐CRP are associated with a high incidence of regression from prediabetes to normoglycemia and reduced odds of progression to diabetes. Subgroup analyses showed a stronger association between hs‐CRP and type 2 diabetes in women than in men. Thus, prediabetes may need to be closely monitored in middle‐aged and older women with elevated hs‐CRP. In addition, whether a lower cutoff value for hs‐CRP elevation in women should be proposed is a question worthy of future research.
Pristine metal-organic frameworks (MOFs) have received much attention in recent years due to their high specific surface areas, large porosity, excellent pore size distributions, flexible structure, ...and remarkable catalytic properties. The design of functional MOFs that can function as efficient HER and OER catalysts is significant in solving the energy crisis but remains a big challenge. Tri-metallic metal-organic frameworks show a good application prospect in water oxidation. In this review, we are going to focus on the latest progress and future trends in the development of pristine trimetallic MOFs with respect to the OER. The synergistic effect between multi-metal active sites is effective at improving the intrinsic activity of MOFs toward the OER. By summarizing the synthesis method of tri-metallic MOFs and observing their performance toward the oxygen evolution reaction, we hope that this review will trigger new developments in coordination chemistry, electrochemistry, nanomaterials and energy materials.
This minireview summarizes the synthesis strategies to access trimetallic MOFs and their catalytic performances toward the oxygen evolution reaction.
The RNA polymerase inhibitor favipiravir is currently in clinical trials as a treatment for infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), despite limited information ...about the molecular basis for its activity. Here we report the structure of favipiravir ribonucleoside triphosphate (favipiravir-RTP) in complex with the SARS-CoV-2 RNA-dependent RNA polymerase (RdRp) bound to a template:primer RNA duplex, determined by electron cryomicroscopy (cryoEM) to a resolution of 2.5 Å. The structure shows clear evidence for the inhibitor at the catalytic site of the enzyme, and resolves the conformation of key side chains and ions surrounding the binding pocket. Polymerase activity assays indicate that the inhibitor is weakly incorporated into the RNA primer strand, and suppresses RNA replication in the presence of natural nucleotides. The structure reveals an unusual, nonproductive binding mode of favipiravir-RTP at the catalytic site of SARS-CoV-2 RdRp, which explains its low rate of incorporation into the RNA primer strand. Together, these findings inform current and future efforts to develop polymerase inhibitors for SARS coronaviruses.
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