Müller glia (MG) are major retinal supporting cells that participate in retinal metabolism, function, maintenance, and protection. During the pathogenesis of diabetic retinopathy (DR), a ...neurovascular disease and a leading cause of blindness, MG modulate vascular function and neuronal integrity by regulating the production of angiogenic and trophic factors. In this article, I will (1) briefly summarize our work on delineating the role and mechanism of MG-modulated vascular function through the production of vascular endothelial growth factor (VEGF) and on investigating VEGF signaling-mediated MG viability and neural protection in diabetic animal models, (2) explore the relationship among VEGF and neurotrophins in protecting Müller cells in in vitro models of diabetes and hypoxia and its potential implication to neuroprotection in DR and hypoxic retinal diseases, and (3) discuss the relevance of our work to the effectiveness and safety of long-term anti-VEGF therapies, a widely used strategy to combat DR, diabetic macular edema, neovascular age-related macular degeneration, retinopathy of prematurity, and other hypoxic retinal vascular disorders.
Abstract
Tuning metal–support interaction has been considered as an effective approach to modulate the electronic structure and catalytic activity of supported metal catalysts. At the atomic level, ...the understanding of the structure–activity relationship still remains obscure in heterogeneous catalysis, such as the conversion of water (alkaline) or hydronium ions (acid) to hydrogen (hydrogen evolution reaction, HER). Here, we reveal that the fine control over the oxidation states of single-atom Pt catalysts through electronic metal–support interaction significantly modulates the catalytic activities in either acidic or alkaline HER. Combined with detailed spectroscopic and electrochemical characterizations, the structure–activity relationship is established by correlating the acidic/alkaline HER activity with the average oxidation state of single-atom Pt and the Pt–H/Pt–OH interaction. This study sheds light on the atomic-level mechanistic understanding of acidic and alkaline HER, and further provides guidelines for the rational design of high-performance single-atom catalysts.
As a promising two‐dimensional conjugated polymer, graphitic carbon nitride (g‐C3N4) has been utilized as a low‐cost, robust, metal‐free, and visible‐light‐active photocatalyst in the field of solar ...energy conversion. This Review mainly describes the latest advances in g‐C3N4 photocatalysts for water splitting. Their application in CO2 conversion, organosynthesis, and environmental purification is also briefly discussed. The methods to modify the electronic structure, nanostructure, crystal structure, and heterostructure of g‐C3N4, together with correlations between its structure and performance are illustrated. Perspectives on the challenges and opportunities for the future exploration of g‐C3N4 photocatalysts are provided. This Review will promote the utilization of g‐C3N4 materials in the fields of photocatalysis, energy conversion, environmental remediation, and sensors.
Metal‐free photocatalysis: Recent progress in g‐C3N4 photocatalysis is highlighted. The four fundamental approaches for modification of g‐C3N4 photocatalysts are discussed: electronic structure modulation, nanostructure design, crystal‐structure engineering, and heterostructure construction. The application of g‐C3N4 photocatalysts are briefly summarized and the opportunities and challenges in this field are discussed.
Background and Aims
The loss of liver regenerative capacity is the most dramatic age‐associated alteration. Because of an incomplete mechanistic understanding of the liver aging process, a successful ...therapeutic strategy to improve liver regeneration in the elderly has not been developed so far. Hepatocyte plasticity is a principal mechanism for producing new hepatocytes and cholangiocytes during regeneration. This study aims to promote the repopulation capacity of elderly hepatocytes by decoding the underlying mechanism about the regulation of aging on human hepatocyte plasticity.
Approach and Results
To understand the age‐related mechanisms, we established a hepatocyte aging model from human‐induced pluripotent stem cells and developed a method for ex vivo characterization of hepatocyte plasticity. We found that hepatocyte plasticity was gradually diminished with aging, and the impaired plasticity was caused by age‐induced histone hypoacetylation. Notably, selective inhibition of histone deacetylases could markedly restore aging‐impaired plasticity. Based on these findings, we successfully improved the plasticity of elderly primary human hepatocytes that enhanced their repopulation capacity in the liver injury model.
Conclusions
This study suggests that age‐induced histone hypoacetylation impairs hepatocyte plasticity, and hepatocyte plasticity might be a therapeutic target for promoting the regenerative capacity of the elderly liver.
Herein, the hydrothermal synthesis of porous ultrathin ternary NiFeV layer double hydroxides (LDHs) nanosheets grown on Nickel foam (NF) substrate as a highly efficient electrode toward overall water ...splitting in alkaline media is reported. The lateral size of the nanosheets is about a few hundreds of nanometers with the thickness of ≈10 nm. Among all molar ratios investigated, the Ni0.75Fe0.125V0.125‐LDHs/NF electrode depicts the optimized performance. It displays an excellent catalytic activity with a modest overpotential of 231 mV for the oxygen evolution reaction (OER) and 125 mV for the hydrogen evolution reaction (HER) in 1.0 m KOH electrolyte. Its exceptional activity is further shown in its small Tafel slope of 39.4 and 62.0 mV dec−1 for OER and HER, respectively. More importantly, remarkable durability and stability are also observed. When used for overall water splitting, the Ni0.75Fe0.125V0.125‐LDHs/NF electrodes require a voltage of only 1.591 V to reach 10 mA cm−2 in alkaline solution. These outstanding performances are mainly attributed to the synergistic effect of the ternary metal system that boosts the intrinsic catalytic activity and active surface area. This work explores a promising way to achieve the optimal inexpensive Ni‐based hydroxide electrocatalyst for overall water splitting.
Porous ultrathin Ni0.75Fe0.125V0.125 layer double hydroxide (LDHs) nanosheets grown on Ni foam (NF) are successfully prepared. The Ni0.75Fe0.125V0.125‐LDHs/NF electrode shows exceptional performance toward the oxygen evolution reaction and especially the hydrogen evolution reaction in alkaline solution. Interestingly, only a single battery unit of 1.5 V can drive water electrolysis, outperforming state‐of‐the‐art IrO2/NF||Pt/C/NF and indicating successful overall water splitting with barely 0.27 V overpotential.
Electrochemical Azidocyanation of Alkenes Zheng, Yun‐Tao; Xu, Hai‐Chao
Angewandte Chemie International Edition,
February 5, 2024, Volume:
63, Issue:
6
Journal Article
Peer reviewed
The difunctionalization of alkenes—a process that installs two functional groups in a single operation and transforms chemical feedstocks into value‐added products—is one of the most appealing ...synthetic methods in contemporary chemistry. However, the introduction of two distinct functional groups via two readily accessible nucleophiles remains a formidable challenge. Existing intermolecular alkene azidocyanation methods, which primarily focus on aryl alkenes and rely on stoichiometric chemical oxidants. We report herein an unprecedented electrochemical strategy for alkene azidocyanation that is compatible with both alkyl and aryl alkenes. This is achieved by harnessing the finely‐tuned anodic electron transfer and the strategic selection of copper/ligand complexes. The reactions of aryl alkenes were rendered enantioselective by employing a chiral ligand. Crucially, the mild conditions and well‐regulated electrochemical process assure exceptional tolerance for various functional groups and substrate compatibility with both terminal and internal alkyl alkenes.
An electrochemical alkene azidocyanation reaction that is compatible with both alkyl and aryl alkenes was developed. The reactions involving aryl alkenes could be obtained with good enantioselectivities by employing a chiral ligand. Notably, this method of alkene difunctionalization employs readily accessible reagents and is distinguished by its demonstrated functional group tolerance.
Dielectric capacitors are widely studied for power supply systems because they can quickly store and release electrical energy. Among various kinds of dielectric materials, antiferroelectrics show ...promising features of high energy‐storage density and efficiency. In this study, epitaxial antiferroelectric PbHfO3 films with different orientations are fabricated, in which remarkable anisotropies of polarization and energy storage properties are discovered. With the optimization of film orientation, much‐improved energy density and excellent high‐temperature efficiency are achieved in the PbHfO3 films. Moreover, the PbHfO3 films are fabricated onto flexible mica substrates, which exhibit excellent property robustness against mechanical bending. This study provides a fundamental understanding of the anisotropic antiferroelectric behaviors of epitaxial PbHfO3 films and provides a generalizable pathway for flexible energy‐storage dielectric capacitors.
In this study, epitaxial antiferroelectric PbHfO3 films with different orientations are fabricated. With the optimization of film orientation, excellent high‐temperature efficiency is achieved in the PbHfO3 films. Moreover, the PbHfO3 films are fabricated onto flexible mica substrates, which exhibit excellent property robustness against mechanical bending. This study provides a fundamental understanding of the anisotropic antiferroelectric behaviors of epitaxial PbHfO3 films.
All-solid-state lithium ion batteries (ASSLBs) are considered next-generation devices for energy storage due to their advantages in safety and potentially high energy density. As the key component in ...ASSLBs, solid-state electrolytes (SSEs) with non-flammability and good adaptability to lithium metal anodes have attracted extensive attention in recent years. Among the current SSEs, composite solid-state electrolytes (CSSEs) with multiple phases have greater flexibility to customize and combine the advantages of single-phase electrolytes, which have been widely investigated recently and regarded as promising candidates for commercial ASSLBs. Based on existing investigations, herein, we present a comprehensive overview of the recent developments in CSSEs. Initially, we introduce the historical development from solid-state ionic conductors to CSSEs, and then summarize the fundamentals including mechanisms of lithium ion transport, key evaluation parameters, design principles, and key materials. Four main types of advanced structures for CSSEs are classified and highlighted according to the recent progress. Moreover, advanced characterization and computational simulation techniques including machine learning are reviewed for the first time, and the main challenges and perspectives of CSSEs are also provided for their future development.
All-solid-state lithium ion batteries (ASSLBs) are considered next-generation devices for energy storage due to their advantages in safety and potentially high energy density.
The Hengduan Mountains (HDM) biodiversity hotspot exhibits exceptional alpine plant diversity. Here, we investigate factors driving intraspecific divergence within a HDM alpine species Salix ...brachista (Cushion willow), a common component of subnival assemblages. We produce a high-quality genome assembly for this species and characterize its genetic diversity, population structure and pattern of evolution by resequencing individuals collected across its distribution. We detect population divergence that has been shaped by a landscape of isolated sky island-like habitats displaying strong environmental heterogeneity across elevational gradients, combined with population size fluctuations that have occurred since approximately the late Miocene. These factors are likely important drivers of intraspecific divergence within Cushion willow and possibly other alpine plants with a similar distribution. Since intraspecific divergence is often the first step toward speciation, the same factors can be important contributors to the high alpine species diversity in the HDM.
The splitting of water into H2 and O2 using solar energy is one of the key steps in artificial photosynthesis for the future production of renewable energy. Here, we show the first use of CoP and Pt ...nanoparticles as dual co‐catalysts to modify graphitic carbon nitride (g‐C3N4) polymer to achieve overall water splitting under visible light irradiation. Our findings demonstrate that loading dual co‐catalysts on delaminated g‐C3N4 imparts surface redox sites on the g‐C3N4 nanosheets that can not only promote catalytic kinetics but also promote charge separation and migration in the soft interface, thus improving the photocatalytic efficiency for overall water splitting. This robust, abundant, and stable photocatalyst based on covalent organic frameworks is demonstrated to hold great promise by forming heterojunctions with CoP and Pt for catalyzing the direct splitting of water into stoichiometric H2 and O2 using energy from photons.
Two are better than one: Graphitic carbon nitride (g‐C3N4)‐modified co‐catalysts with two different functions are prepared to achieve overall water splitting under visible light irradiation in the absence of any sacrificial agent. CoP colloidal nanocrystals and Pt nanoparticles act as co‐catalysts that not only effectively suppress the recombination of carriers but also greatly enhance reaction kinetics. However, it is important to achieve pure water splitting that a suitable loading of the co‐catalysts is chosen.
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