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【Objective】 The ecological functions of a river are manifold; and how to determine river flow rates which are ecologically sustainable is important but not trivial. In this paper, we proposed a new approach to model river habitat. 【Method】 The model is based on multiple indicator species and considers their competition as well as the consequence for growth of individual species. The model is constructed based on the fuzzy logic method to establish the quantitative relationship between river habitat quality and runoff conditions. We applied the model to the Xinyang section of the Shihe River. 【Result】 The sustainable ecological water flow in this section of the river calculated by the model is 160~260 m3/s, and the minimum ecological flow rate is 60 m3/s. The result interval is stricter than that calculated from the single indicator species model using crucian carp as the indicator. 【Conclusion】 Multiple indicator species model we proposed for determining ecologically sustainable river flow is robust and accurate. It can be used for designing sustainable development and utilization of river water resources.

Exploring non-precious oxygen reduction reaction (ORR) catalysts is essential to fuel cells and seawater metal–air batteries. Transition metal nitrides are promising ORR catalysts with high corrosion resistance but fail to render satisfactory ORR performance. Herein, we introduce a novel method for the synthesis of carbon nanosheet-supported transition metal nitrides. Using dicyandiamine (DCDA) as the nitrogen and carbon source, we prepared carbon nanosheet-supported CrN nanoparticles (CrN/CNS) via a two-step pyrolysis method. The optimal CrN/CNS material has an ORR half-wave potential (E1/2) of 0.76 V vs. reversible hydrogen electrode (RHE) in acidic media and 0.50 V vs. RHE in simulated seawater, which is one of the best among those reported for transition metal nitrides. Furthermore, the optimal material has remarkable ORR stability in both acidic media and simulated seawater. Its ORR E1/2 shows 27 mV decay in acidic media and 20 mV increase in simulated seawater after stability tests, outperforming a commercial Pt/C catalyst and many transition metal nitrides. More importantly, the optimal CrN/CNS material-based seawater Zn–air batteries (ZABs) exhibit good stability within 200 h constant discharging. It is found that both the proportion of the Cr–N valence state and the Cr content in surfaces played a key role in the ORR activity of CrN/CNS materials. [ABSTRACT FROM AUTHOR]

Although anion exchange membrane water electrolyzer (AEMWE) is an emerging device in the green hydrogen production industry, the use of alkaline electrolyte tackles the practicality due to the issues of lowering system efficiency and environmental impacts. State‐of‐the‐art technology using pure water as an electrolyte is advancing to overcome the current challenges of AEMWE. In particular, the development of this technology requires a comprehensive evaluation of techno‐economic aspects, aiming to balance innovation with cost considerations. This involves the critical development of advanced catalysts, membranes, and devices designed for efficiency, as well as assessing their economic viability amidst prevailing technological challenges. This review delves into the timely technical challenges of developing pure water‐fed AEMWE, highlights current progress and research prospects, and suggests opportunities for advancing AEMWE technology. This review also emphasizes the importance of advanced characterization techniques for effective analysis and evaluation in this context. [ABSTRACT FROM AUTHOR]

In the electrocatalytic CO2 reduction reaction (CO2RR), metal catalysts with an oxidation state generally demonstrate more favorable catalytic activity and selectivity than their corresponding metallic counterparts. However, the persistence of oxidative metal sites under reductive potentials is challenging since the transition to metallic states inevitably leads to catalytic degradation. Herein, a thorough review of research on oxidation-state stabilization in the CO2RR is presented, starting from fundamental concepts and highlighting the importance of oxidation state stabilization while revealing the relevance of dynamic oxidation states in product distribution. Subsequently, the functional mechanisms of various oxidation-state protection strategies are explained in detail, and in situ detection techniques are discussed. Finally, the prevailing and prospective challenges associated with oxidation-state protection research are discussed, identifying innovative opportunities for mechanistic insights, technology upgrades, and industrial platforms to enable the commercialization of the CO2RR. [ABSTRACT FROM AUTHOR]

The aim of the present study was to investigate the role and mechanism of microRNA-204-5p (miR-204-5p) in atherosclerosis (AS)-related abnormal human vascular smooth muscle cells (hVSMCs) function. Firstly, we analyzed the expression of miR-204-5p and found that the miR-204-5p expression level was clearly downregulated in atherosclerotic plaque tissues and blood samples compared to the normal controls. Then, matrix metallopeptidase-9 (MMP-9) was predicted to be the potential target of miR-204-5p by TargetScan and this prediction was confirmed by luciferase assays. Besides, we observed that miR-204-5p could negatively regulate the expression of MMP-9 in hVSMCs. Subsequently, Thiazolyl Blue Tetrazolium Bromide (MTT) assay, transwell assay and flow cytometry were performed to detect the proliferation, migration and apoptosis of hVSMCs. Down-expression of miR-204-5p led to the promotion of proliferation and migration accompanied with the suppression of apoptosis in hVSMCs, and these effects were reversed by MMP-9-siRNA. In addition, overexpressed miR-204-5p could inhibit hVSMC proliferation and migration and promote the apoptosis of hVSMCs. However, the effects were also abrogated by overexpressed MMP-9. Together, our findings showed that miR-204-5p plays an important role in the growth and migration of hVSMCs by targeting MMP-9, which might be a novel biomarker and promising therapeutic target for AS.

Comprehensive Summary: Seawater electrolysis holds great promise for hydrogen production in the future, while the development of anodic catalysts has been severely hampered by the side‐reaction, chloride evolution reaction. In this work, nano‐flower‐cluster structured CoO@FeSe2/CF catalysts are synthesized via a scalable electrodeposition technique, and the performance is systematically studied. The oxygen evolution reaction (OER) overpotential of CoO@FeSe2/CF is 267 mV at 100 mA·cm−2, which is significantly lower than that of the IrO2 catalyst (435 mV). Additionally, the catalyst shows high selectivity for OER (97.9%) and almost no loss of activity after a durability test for 1100 h. The impressive performance is attributed to the dense rod‐like structure with abundant active centers after electrochemical activation and the in‐situ generated CoOOH and FeOOH that improve the catalytic activity of the catalyst. The synergistic effect induced by the non‐uniform structure endows the catalyst with excellent stability. [ABSTRACT FROM AUTHOR]

Electrochemical structural reconstruction of catalysts may generate real active sites that differ from the initial catalyst, but is often ignored. Herein, combining in situ and ex situ techniques, it is identified that the bismuth nanosheets (NS) dotted with large numbers of coordinatively unsaturated pit sites is produced via the in situ structural reconstruction of Bi(OH)3 NS. Such reconstructed Bi NS shows greatly improved catalytic activity toward CO2 electroreduction, with a 2.6‐fold increase in current density compared with intact Bi NS, high Faradaic efficiency for HCOO− production (>95%), and an extraordinary turnover frequency of 0.35 s−1 at −0.98 VRHE. In addition, it delivers industrial‐relevant current density of 325 mA cm−2 without compromising selectivity in a flow cell. The mechanistic studies demonstrate that these coordinatively unsaturated sites acting as the real active sites favor the stabilization of key intermediate *OCHO, which thus facilitate the reaction kinetics for HCOO− production. This work not only provides a unique perspective on the construction of efficient catalysts for CO2 electroreduction, but also implies the importance in recognition of structural reconstruction. [ABSTRACT FROM AUTHOR]