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Gas-involving electrochemical reactions, like oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER), are critical processes for energy-saving, environment-friendly energy conversion and storage technologies which gain increasing attention. The development of according electrocatalysts is key to boost their electrocatalytic performances. Dramatic efforts have been put into the development of advanced electrocatalysts to overcome sluggish kinetics. On the other hand, the electrode interfaces-architecture construction plays an equally important role for practical applications because these imperative electrode reactions generally proceed at triple-phase interfaces of gas, liquid electrolyte, and solid electrocatalyst. A desirable architecture should facilitate the complicate reactions occur at the triple-phase interfaces, which including mass diffusion, surface reaction and electron transfer. In this review, we will summarize some design principles and synthetic strategies for optimizing triple-phase interfaces of gas-involving electrocatalysis systematically, based on the electrode reaction process at the three-phase interfaces. It can be divided into three main optimization directions: exposure of active sites, promotion of mass diffusion and acceleration of electron transfer. Furthermore, we especially highlight several remarkable works with comprehensive optimization about specific energy conversion devices, including metal-air batteries, fuel cells, and water-splitting devices are demonstrated with superb efficiency. In the last section, the perspectives and challenges in the future are proposed.

The use of nitrogen fertilizers has been estimated to have supported 27% of the world’s population over the past century. Urea (CO(NH2)2) is conventionally synthesized through two consecutive industrial processes, N2 + H2 → NH3 followed by NH3 + CO2 → urea. Both reactions operate under harsh conditions and consume more than 2% of the world’s energy. Urea synthesis consumes approximately 80% of the NH3 produced globally. Here we directly coupled N2 and CO2 in H2O to produce urea under ambient conditions. The process was carried out using an electrocatalyst consisting of PdCu alloy nanoparticles on TiO2 nanosheets. This coupling reaction occurs through the formation of C–N bonds via the thermodynamically spontaneous reaction between *N=N* and CO. Products were identified and quantified using isotope labelling and the mechanism investigated using isotope-labelled operando synchrotron-radiation Fourier transform infrared spectroscopy. A high rate of urea formation of 3.36 mmol g–1 h–1 and corresponding Faradic efficiency of 8.92% were measured at –0.4 V versus reversible hydrogen electrode.Conventionally, urea is synthesized via two consecutive processes, N2 + H2 → NH3 followed by NH3 + CO2. Now, an electrocatalyst consisting of PdCu alloy nanoparticles on TiO2 nanosheets has been shown to directly couple N2 and CO2 in H2O to produce urea under ambient conditions.

Hydrogen production through water electrolysis is of considerable interest for converting the intermittent electricity generated by renewable energy sources into storable chemical energy, but the typical water electrolysis process requires a high working voltage (>1.23 V) and produces oxygen at the anode in addition to hydrogen at the cathode. Here we report a hydrogen production system that combines anodic and cathodic H 2 production from low-potential aldehyde oxidation and the hydrogen evolution reaction, respectively, at a low voltage of ~0.1 V. Unlike conventional aldehyde electrooxidation, in which the hydrogen atom of the aldehyde group is oxidized into H 2 O at high potentials, the low-potential aldehyde oxidation enables the hydrogen atom to recombine into H 2 gas. The assembled electrolyser requires an electricity input of only ~0.35 kWh per m 3 of H 2 , in contrast to the ~5 kWh per m 3 of H 2 required for conventional water electrolysis. This study provides a promising avenue for the safe, efficient and scalable production of high-purity hydrogen. Hydrogen production from water electrolysis requires high working voltages and produces H 2 only at the cathode. Now, H 2 generation during the oxidation of biomass-derived aldehydes is combined with the hydrogen evolution reaction on the cathode for low-voltage H 2 production.

High-temperature proton-exchange membrane fuel cells (HT-PEMFCs) have shown a broad prospect of applications due to the enhanced reaction kinetics and simplified supporting system. However, the proton conductor, phosphoric acid, tends to poison the active sites of Pt, resulting in high Pt consumption. Herein, Pt nanoparticles anchored on SiO 2 -modified carbon nanotubes (CNT@SiO 2 -Pt) are prepared as high-performance cathode catalysts for HT-PEMFCs. The SiO 2 in CNT@SiO 2 -Pt can induce the adsorption of phosphoric acid transferring from Pt active sites in the catalytic layer, avoiding the poisoning of the Pt, and the phosphate fixed by SiO 2 provide a high-speed proton conduction highway for oxygen reduction reactions. Accordingly, The CNT@SiO 2 -Pt cathode achieve superior power density of 765 mW cm −2 (160 °C) and 1,061 mW cm −2 (220 °C) due to the rapid proton-coupled electron process and outstanding stability in HT-PEMFCs. This result provides a new road to resolve the phosphate poisoning for the commercialization of HT-PEMFCs.

Polyelectrolyte membrane fuel cell (PEMFC) is a kind of clean energy conversion device with great potential. The development of related hydrogen-oxygen fuel cell catalysts is still one of the key issues. Single atoms have high surface areas but weak metal synergies. Nanoparticles have good metal synergies but a large surface area. Cluster materials are in between, but as the research moves from single atoms to nanoclusters, the relationship between structure and reaction properties becomes complex. Focusing on fuel cells' hydrogen oxidation and oxygen reduction reactions, this review introduces the supported catalysts of hydrogen-oxygen fuel cell from synthesis, structural activity relationship, evolution of structural properties, mechanism and synergistic strategy. The main catalyst types are mainly concentrated in zero-dimensional materials (single atoms, clusters, nanoparticles), co-catalyst/support materials mainly non-metallic base alloys (C/Si/N/P, etc.) and metal oxides. By introducing some robust interaction strategies, the importance of support materials for synergistic enhancement of the overall performance of catalysts is emphasized, and the importance of advanced in situ characterization techniques for structure-property and mechanism studies is introduced. Finally, the challenge and prospect for developing the fuel cell electrocatalysts were concluded for commercial applications. [Display omitted]

Phosphoric acid (PA) is a vital proton-conducting medium for high-temperature proton exchange membrane fuel cells (HT-PEMFCs); however, regulating its distribution to decrease poisoning on the electrocatalysts and maintain elevated reactivity durability remains a significant challenge. In this work, defective g-C 3 N 4 (D-C 3 N 4 ) was incorporated into Pt/C catalyst layers to promote PA distribution for enhancing the intrinsic reactivity expression of catalysts. Following decoration of D-C 3 N 4 , HT-PEMFCs with low Pt loading in both the anode (0.20 mg Pt cm −2 ) and the cathode (0.40 mg Pt cm −2 ) exhibited a high peak power density of 672 mW cm −2 and excellent high reactivity durability (above 620 mW cm −2 ) after accelerated 3500 cycles, which is far superior to previously published results. This work first reveals that the acid/base interaction of D-C 3 N 4 with PA modulates PA distribution in the catalytic layer, thereby enhancing the intrinsic reactivity expression and utilization efficiency of catalysts in HT-PEMFCs.

Gonadotrophin-releasing hormone (GnRH), also known as luteinizing hormone-releasing hormone, is the main regulator of the reproductive system, acting on gonadotropic cells by binding to the GnRH1 receptor (GnRH1R). The GnRH-GnRH1R system is a promising therapeutic target for maintaining reproductive function; to date, a number of ligands targeting GnRH1R for disease treatment are available on the market. Here, we report the crystal structure of GnRH1R bound to the small-molecule drug elagolix at 2.8 Å resolution. The structure reveals an interesting N-terminus that could co-occupy the enlarged orthosteric binding site together with elagolix. The unusual ligand binding mode was further investigated by structural analyses, functional assays and molecular docking studies. On the other hand, because of the unique characteristic of lacking a cytoplasmic C-terminal helix, GnRH1R exhibits different microswitch structural features from other class A GPCRs. In summary, this study provides insight into the ligand binding mode of GnRH1R and offers an atomic framework for rational drug design. The human gonadotropin-releasing hormone receptor GnRH1R is a GPCR with an important role in the human reproductive system and of interest as a drug target. Here, the authors present the 2.8 Å crystal structure of human GnRH1R with the high affinity antagonist drug Elagolix and the observed unusual ligand binding mode was further analysed with functional assays and molecular docking studies.

Hair follicle development and hair growth are regulated by multiple factors and multiple signalling pathways. The hair follicle, as an important skin appendage, is the basis for hair growth, and it has the functions of safeguarding the body, perceiving the environment and regulating body temperature. Hair growth undergoes a regular hair cycle, including anagen, catagen and telogen. A small amount of physiological shedding of hair occurs under normal conditions, always in a dynamic equilibrium. Hair loss occurs when the skin or hair follicles are stimulated by oxidative stress, inflammation or hormonal disorders that disrupt the homeostasis of the hair follicles. Numerous researches have indicated that oxidative stress is an important factor causing hair loss. Here, we summarize the signalling pathways and intervention mechanisms by which oxidative stress affects hair follicle development and hair growth, discuss existing treatments for hair loss via the antioxidant pathway and provide our own insights. In addition, we collate antioxidant natural products promoting hair growth in recent years and discuss the limitations and perspectives of current hair loss prevention and treatment.

The rapid emergence of SARS-CoV-2 variants of concern, the complexity of infection, and the functional redundancy of host factors, underscore an urgent need for broad-spectrum antivirals against the continuous COVID-19 pandemic, with drug repurposing as a viable therapeutic strategy. Here we report the potential of RNA G-quadruplex (RG4)-targeting therapeutic strategy for SARS-CoV-2 entry. Combining bioinformatics, biochemical and biophysical approaches, we characterize the existence of RG4s in several SARS-CoV-2 host factors. In silico screening followed by experimental validation identify Topotecan (TPT) and Berbamine (BBM), two clinical approved drugs, as RG4-stabilizing agents with repurposing potential for COVID-19. Both TPT and BBM can reduce the protein level of RG4-containing host factors, including ACE2, AXL, FURIN, and TMPRSS2. Intriguingly, TPT and BBM block SARS-CoV-2 pseudovirus entry into target cells in vitro and murine tissues in vivo . These findings emphasize the significance of RG4 in SARS-CoV-2 pathogenesis and provide a potential broad-spectrum antiviral strategy for COVID-19 prevention and treatment.

Acute ultraviolet (UV)-B radiation is the major external factor causing photodamage. In this study, we aimed to determine the effects of Dendrobium nobile Lindl. polysaccharides (DNPs) on photodamage in HaCaT keratinocytes after UVB irradiation and the underlying mechanisms. We found that DNPs significantly attenuated the decline in the viability and proliferation of HaCaT cells after UVB irradiation. Moreover, DNPs scavenged reactive oxygen species (ROS), improved the activities of endogenous antioxidant enzymes, including superoxide dismutase, catalase, and glutathione peroxidase, and reduced the levels of malondialdehyde, while partially attenuating cell cycle arrest, suggesting their antioxidant and anti-apoptotic properties. The mitogen-activated protein kinase (MAPK) pathway was found to be important for the attenuation of UVB-induced photodamage in the HaCaT cells. Furthermore, DNPs exerted cytoprotective effects by downregulating UVB-induced ROS-mediated phosphorylation of MAPKs, including p38, c-Jun N-terminal kinase, and extracellular signal-regulated kinase, and by inhibiting p53 expression as well as the apoptotic cascade response. Therefore, DNPs ameliorated UVB-induced oxidative damage and apoptosis in HaCaT cells via the regulation of MAPKs. Our findings thus highlight the Dendrobium nobile Lindl polysaccharides as promising therapeutic candidates for UVB-induced photodamage.