The sustainable production and efficient utilization of hydrogen are central to achieving global carbon neutrality.

The unclear decisive factors make it tricky to realize high activity and selectivity for the methanol oxidation reaction (MOR) at an industrial-level current. Using Ni-based hydroxides as model catalysts, we reveal that Ni sites undergo a progressive dehydrogenation from NiO2H2 to low-hydrogen-coverage NiO2H1-x species, which serve as the active centers under high current densities. This transformation shifts the rate-determining step from catalyst dehydrogenation (NOR mechanism) to *CH3O dehydrogenation, while the adsorption behavior of *HCOO dictates product selectivity. Guided by these insights, a Fe-NiCo ternary hydroxide catalyst was rationally designed to modulate intermediate adsorption energetics. The optimized Fe-NiCo-TH catalyst delivers industrially relevant MOR performance, achieving >500 mA cm(-2) at 1.47 V, >90% formate selectivity, and excellent long-term durability. This study establishes hydrogen-coverage-dependent active sites as a decisive factor in MOR and provides a mechanistic foundation for designing Ni-based electrocatalysts for coupled hydrogen production.

High oxygen reduction reaction (ORR) activity and stability of cathode catalyst is one of key issues to obtain high performance proton-exchange membrane fuel cells. The most successful ORR catalysts are Pt/C based composites for their stable ORR activity in acidic electrolyte in practical application. Heteroatoms doped carbon materials especially nitrogen doped carbon supports for Pt are found to be highly effective in improving ORR activity of Pt/ C based catalysts. However, research on distribution of doped nitrogen in carbon materials and its influence on ORR activity and stability is rare. In this work, we report a nitrogen doped carbon nanosheet (NC) with nonuniform distribution of doped nitrogen. Nitrogen enriched microporous regions are found to be favorable for selective anchoring Pt nanoparticles by the strong Pt-N interaction. The influence of non-uniform doped nitrogen on ORR activity and stability of Pt/NC catalysts via statistical analysis changes of Pt nanoparticles' size and their distribution before and after accelerated durability test (ADT) is carried out. It is found that NC with appropriate non-uniform doped nitrogen can well tune disperse anchoring of Pt nanoparticles and their size on NC surface and effectively improving and stabilizing activity of Pt in acidic electrolyte environment than commercial Pt/C catalyst.

The electrocatalytic nitrogen reduction reaction (NRR) is recognized as a promising next-generation technology for efficient and environmentally friendly nitrogen fixation, attracting significant research interest. However, significant hydrogen evolution reaction (HER) frequently accompanies the electrocatalytic NRR, and substituting the electrolyte with a neutral solution that provides limited protons can substantially reduce HER kinetics. Consequently, the development of NRR electrocatalysts tailored for neutral media becomes essential. Here we design and synthesize a FeS2/MoS2 catalyst to enable effective NRR catalysis in neutral media. The asymmetric electron distribution between FeS2 and MoS2 generates localized electrophilic and nucleophilic regions at their interface in the catalyst. Specifically, electron transfer from FeS2 to MoS2 leads to the formation of electrondeficient regions near the FeS2 side, which facilitate the adsorption of nitrogen molecules by accepting their lone pair electrons. Experimental results indicate that the FeS2/MoS2-1 nanocomposite catalyst achieves an ammonia yield of 76.65 mu g h- 1 mgcat -1 and a Faradaic efficiency of 18.37 % in 0.1 M PBS electrolyte, demonstrating outstanding catalytic performance for NRR under neutral electrolyte.

The electrochemical oxygen evolution reaction (OER) can be combined with various reactions to fabricate electrochemical energy conversion and storage devices while the slow kinetics and poor mass transfer capability at high current densities are the key constraints to its large-scale application. Therefore, this review primarily focuses on design and optimization of mass transfer structures of TM-metal-based OER catalysts. Nanostructuring, porous design, and the creation of hierarchical architectures have been applied during catalyst synthesis to enhance the surface area and accessibility, thereby improving mass transfer and catalytic OER efficiency. Strategies including doping, substrate invitation, soft/hard templating have been utilized to accelerate mass transfer as well as the ion/electron conduction efficiency for the overall improvement of OER performance of the catalysts. These developments underline the critical role of advanced material design in achieving high-performance OER catalysts and highlight the potential of TM-based materials in cost-effective and scalable applications.

Aiming to boosting the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) efficiency on the cost-effective transition metal catalysts, an in-situ mass transfer channel construction strategy is proposed for the carbon encapsulated Fe catalyst synthesis. By using Zn as sacrificial porogen and controlling the pyrolysis temperature during the catalyst synthesis, space left in the porous N-C encapsulated Fe (ZnFe-NC) catalyst due to the Zn evaporated can act as oxygen/water transfer channel for effective triple-phase boundary construction. Therefore, overpotential to deliver 10 mA cm-2 OER is low to 295 mV while half-slope potential of ORR is high to 0.88 V vs. RHE. Zinc-air battery using ZnFe-NC as the bi-functional oxygen catalyst exhibits both significantly improved power density and stability compared with that with the Pt/C-IrO2 2 catalysts, indicating the great application potential of the ZnFe-NC catalyst with in-situ constructed mass transfer channels.

AbstractThe electrochemical alcohol oxidation reaction (AOR) is pivotal for the development of sustainable energy. The complete oxidation of alcohols has attracted extensive attention as a vital process in fuel cells. Moreover, as an alternative reaction to the oxygen evolution reaction, the selective oxidation of alcohols emerges as an effective means to lower the energy expenditure associated with electrolytic hydrogen production while yielding high‐value products. Nonprecious metal materials have been widely applied in the selective oxidation catalysis of alcohols due to their cost‐effectiveness and excellent durability. In recent years, leveraging the advantages of nonprecious metal materials in electrocatalytic AOR, researchers have delved into catalytic mechanisms and various efficient catalysts have been fabricated and evaluated. This review provides an overview of the current advancements in the electrocatalytic selective oxidation of diverse alcohols and the catalytic systems centered around nonprecious metal materials. It systematically summarizes the shared traits and distinctions in catalytic reaction characteristics across various systems, thereby laying the theoretical foundation for developing novel catalyst systems that are efficient, stable, and highly selective. This review will facilitate the utilization of nonprecious metal catalysts further toward the electrocatalytic oxidation of alcohols.

Developing highly active oxygen evolution reaction（OER） electrocatalysts with robust durability is essential in producing high-purity hydrogen through water electrolysis. Layered double hydroxide（LDH） based catalysts have demonstrated efficient catalytic performance toward the relatively sluggish OER. By considering the promotion effect of phosphate（Pi） on proton transfer, herein, a facile phosphate acid（PA）surface-neutralization strategy is developed to in-situ construct NiCo-LDH/NiCoPi hetero-sheets toward OER catalysis. OER activity of NiCoLDH is significantly boosted due to the proton promotion effect and the electronic modulation effect of NiCoPi. As a result, the facilely prepared NiCo-LDH/NiCoPi catalyst displays superior OER catalytic activity with a low overpotential of 300 mV to deliver 100 mA cm -2 OER and a Tafel slope of 73 mV dec -1 . Furthermore, no visible activity decay is detected after a 200-h continuous OER operation. The present work,therefore, provides a promising strategy to exploit robust OER electrocatalysts for commercial water electrolysers.

Gastrointestinal bleeding (GIB) after heart transplantation (HT) remains a significant clinical issue. This study aimed to explore the incidence, trends, outcomes, and clinical predictors of GIB in HT patients. Adult patients who underwent HT between 2015 and 2021 at Union Hospital were recruited and divided into two groups based on the presence or absence of postoperative GIB. The primary outcomes were evaluated at follow-up. Independent predictors of GIB after HT were identified using a logistic regression analysis. A nomogram prediction model was constructed according to these independent variables, and the accuracy of the model was assessed using the receiver operating characteristic (ROC) curve and the calibration curve. Among the 461 patients, 40 (8.7%) developed GIB post-HT. HT patients with postoperative GIB exhibited higher in-hospital, 30-day, 90-day, and 1-year mortality (all p < 0.05). A multivariate analysis was used to identify age, preoperative warfarin, postoperative continuous renal replacement therapy, and postoperative nasogastric tubes as independent risk factors for GIB following HT. A nomogram prediction model was applied using the four variables. The area under the curve (AUC) of this model was 0.852 (95% CI: 0.787–0.917, p < 0.001), and the calibration curve was close to the ideal diagonal line. GIB following HT is associated with a poor clinical prognosis. The constructed nomogram demonstrated a favorable predictive value for GIB.

In situ regeneration is a promising strategy for constructing tissue engineering heart valves (TEHVs). Currently, the decellularized heart valve (DHV) is extensively employed as a TEHV scaffold. Nevertheless, DHV exhibits limited blood compatibility and notable difficulties in endothelialization, resulting in thrombosis and graft failure. The red blood cell membrane (RBCM) exhibits excellent biocompatibility and prolonged circulation stability and is extensively applied in the camouflage of nanoparticles for drug delivery; however, there is no report on its application for large-scale modification of decellularized extracellular matrix (ECM). For the first time, we utilized a layer-by-layer assembling strategy to immobilize RBCM on the surface of DHV and construct an innovative TEHV scaffold. Our findings demonstrated that the scaffold significantly improved the hemocompatibility of DHV by effectively preventing plasma protein adsorption, activated platelet adhesion, and erythrocyte aggregation, and induced macrophage polarization toward the M2 phenotype in vitro. Moreover, RBCM modification significantly enhanced the mechanical properties and enzymatic stability of DHV. The rat models of subcutaneous embedding and abdominal aorta implantation showed that the scaffold regulated the polarization of macrophages into the anti-inflammatory and pro-modeling M2 phenotype and promoted endothelialization and ECM remodeling in the early stage without thrombosis and calcification. The novel TEHV exhibits excellent performance and can overcome the limitations of commonly used clinical prostheses.

In response to the increase in retired lithium-ion batteries (LIBs), there is a rising trend in lithium recycling, which can not only address the scarcity of lithium resources but also mitigate environmental pollution caused by battery waste. In this study, we present an electrocatalytic strategy for formate oxidation reaction (FOR) aimed at facilitating lithium recovery coupled hydrogen production. The obtained results have indicated that the synthesized Cu-based oxide can efficiently catalyze FOR, achieving a current density of 500 mA cm- 2 at only 1.534 V vs. RHE. According to density functional theory calculations, the adsorption strength of the intermediate specie HCOO on Cu-based oxide is reduced (-0.36 eV) compared to Ni-based oxide (-2.27 eV), resulting in a thermodynamically favorable step for the rate-determining HCOO dehydrogenation reaction. Assembling a FOR coupled hydrogen evolution reaction (HER) electrolysis system can achieve hydrogen production and Li recovery (Li recovery product is Li2CO3) by electrolyzing alkaline raffinate containing lithium. This approach eliminates the need for additional formic acid and sodium carbonate, thereby reducing material consumption and ultimately enhancing the economic efficiency of the lithium battery recovery strategy.

Background and Aims Valve interstitial cells (VICs) undergo a transition to intermediate state cells before ultimately transforming into the osteogenic cell population, which is a pivotal cellular process in calcific aortic valve disease (CAVD). Herein, this study successfully delineated the stages of VIC osteogenic transformation and elucidated a novel key regulatory role of lumican (LUM) in this process.Methods Single-cell RNA-sequencing (scRNA-seq) from nine human aortic valves was used to characterize the pathological switch process and identify key regulatory factors. The in vitro, ex vivo, in vivo, and double knockout mice were constructed to further unravel the calcification-promoting effect of LUM. Moreover, the multi-omic approaches were employed to analyse the molecular mechanism of LUM in CAVD.Results ScRNA-seq successfully delineated the process of VIC pathological transformation and highlighted the significance of LUM as a novel molecule in this process. The pro-calcification role of LUM is confirmed on the in vitro, ex vivo, in vivo level, and ApoE-/-//LUM-/- double knockout mice. The LUM induces osteogenesis in VICs via activation of inflammatory pathways and augmentation of cellular glycolysis, resulting in the accumulation of lactate. Subsequent investigation has unveiled a novel LUM driving histone modification, lactylation, which plays a role in facilitating valve calcification. More importantly, this study has identified two specific sites of histone lactylation, namely, H3K14la and H3K9la, which have been found to facilitate the process of calcification. The confirmation of these modification sites' association with the expression of calcific genes Runx2 and BMP2 has been achieved through ChIP-PCR analysis.Conclusions The study presents novel findings, being the first to establish the involvement of lumican in mediating H3 histone lactylation, thus facilitating the development of aortic valve calcification. Consequently, lumican would be a promising therapeutic target for intervention in the treatment of CAVD. Structured Graphical Abstract Single-cell RNA-sequencing (scRNA-seq) delineated the process of valve interstitial cell (VIC) pathological transformation and highlighted the significance of lumican (LUM) as a novel molecule in this process. The pro-calcification role of LUM was confirmed in the in vitro, ex vivo, and ApoE-/-//LUM-/- double knockout mice. The LUM induced osteogenesis in VICs via augmentation of cellular glycolysis, resulting in the accumulation of lactate. Subsequent multi-omic approaches and molecular biological verification unveiled a novel LUM driving H3 histone modification, lactylation, which plays a role in facilitating valve calcification

Nucleophile oxidation reactions, represented by the incomplete methanol oxidation reaction (i-MOR) to formic acid, can effectively lower the potential of electrolytic hydrogen production while generating high-value products.

BACKGROUND: A main obstacle in current valvular heart disease research is the lack of high-quality homogeneous functional heart valve cells. Human induced pluripotent stem cells (hiPSCs)-derived heart valve cells may help with this dilemma. However, there are no well-established protocols to induce hiPSCs to differentiate into functional heart valve cells, and the networks that mediate the differentiation have not been fully elucidated. METHODS: To generate heart valve cells from hiPSCs, we sequentially activated the Wnt, BMP4, VEGF (vascular endothelial growth factor), and NFATc1 signaling pathways using CHIR-99021, BMP4, VEGF-165, and forskolin, respectively. The transcriptional and functional similarity of hiPSC-derived heart valve cells compared with primary heart valve cells were characterized. Longitudinal single-cell RNA sequencing was used to uncover the trajectory, switch genes, pathways, and transcription factors of the differentiation. RESULTS: An efficient protocol was developed to induce hiPSCs to differentiate into functional hiPSC-derived valve endothelial-like cells and hiPSC-derived valve interstitial-like cells. After 6-day differentiation and CD144 magnetic bead sorting, ≈70% CD144 + cells and 30% CD144 – cells were obtained. On the basis of single-cell RNA sequencing data, the CD144 + cells and CD144 – cells were found to be highly similar to primary heart valve endothelial cells and primary heart valve interstitial cells in gene expression profile. Furthermore, CD144 + cells had the typical function of primary heart valve endothelial cells, including tube formation, uptake of low-density lipoprotein, generation of endothelial nitric oxide synthase, and response to shear stress. Meanwhile, CD144 – cells could secret collagen and matrix metalloproteinases, and differentiate into osteogenic or adipogenic lineages like primary heart valve interstitial cells. Therefore, we identified CD144 + cells and CD144 – cells as hiPSC-derived valve endothelial-like cells and hiPSC-derived valve interstitial-like cells, respectively. Using single-cell RNA sequencing analysis, we demonstrated that the trajectory of heart valve cell differentiation was consistent with embryonic valve development. We identified the main switch genes (NOTCH1, HEY1, and MEF2C), signaling pathways (TGF-β, Wnt, and NOTCH), and transcription factors (MSX1, SP5, and MECOM) that mediated the differentiation. Finally, we found that hiPSC-derived valve interstitial-like cells might derive from hiPSC-derived valve endothelial-like cells undergoing endocardial-mesenchymal transition. CONCLUSIONS: In summary, this is the first study to report an efficient strategy to generate functional hiPSC-derived valve endothelial-like cells and hiPSC-derived valve interstitial-like cells from hiPSCs, as well as to elucidate the differentiation trajectory and transcriptional dynamics of hiPSCs differentiated into heart valve cells.

Realizing rapid transformation of hydroxide to high-active oxyhydroxide species in layered double hydroxide (LDH) catalyst plays a significant role in enhancing its activity toward oxygen evolution reaction (OER) for hydrogen production from water. Here, a scalable strategy is developed to synthesize defect-rich few-layered NiFe-LDH nanosheets (f-NiFe-LDH-B) with in situ borate modified for boosted and stable OER due to that the borate can narrow the bandgap for Ni sites to realize a more conductive electronic structure. Besides, the adsorbed borate can tune the d band center of Ni sites to promote of hydroxide transformation and facilitate the adsorption of the OER intermediates. The f-NiFe-LDH-B catalyst, therefore, requires only 209 and 249 mV overpotential to deliver 10 and 100 mA cm-2 OER, respectively, with a Tafel slope of 43.5 mV dec-1. Moreover, only 1.8 V cell voltage is required to reach Ampere-level overall water splitting for 500 h at room temperature. A facile and scalable strategy to fabricating borate modified few-layered NiFe-LDH is proposed for efficient OER. Benefiting from the in situ adsorbed borate and the defect-rich structure, the as-prapared f-NiFe-LDH-B catalyst only requires 209 mV overpotential to deliver 10 mA cm-2, with a low Tafel slope of 43.5 mV dec-1. When coupled with NiMoN, the water electrolysis cell only requires 1.8 V to reach Ampere-level overall water splitting for 500 h at room temperature.image

Due to its low equilibrium potential, urea oxidation reaction (UOR) is an advantageous alternative to the conventional anodic water oxidation reaction (OER) for energy-saving hydrogen production. Developing energyand time-saving methods to synthesize active and stable UOR catalysts is significant. Herein, we present a simple and time-efficient method for the direct growth of defect-rich few-layered NiMn-layered double hydroxide (NiMn-LDH) nanosheets on nickel foam at ambient temperature and pressure. The defect-rich, few-layered structure exposes numerous active sites, promoting the formation of high -oxidation state Ni species at low overpotentials. Additionally, the introduction of Mn facilitates Ni oxidation and stabilizes in-situ formed NiOOH species. The optimized f-NiMn-LDH catalyst exhibits compelling UOR activity, requiring only 1.310/1.330/ 1.387 V for 10/100/400 mA cm -2 UOR, respectively. When used directly in urea-assisted hydrogen production, it achieves a low cell voltage of 1.436 V for a high current density of 100 mA cm -2, representing a substantial 249 mV reduction compared to water electrolysis. This work offers a simple strategy for preparing highperformance electrocatalysts for energy-efficient hydrogen production via urea-assisted water splitting.

Tissue engineered heart valves (TEHVs) demonstrates the potential for tissue growth and remodel, offering particular benefit for pediatric patients. A significant challenge in designing functional TEHV lies in replicating the anisotropic mechanical properties of native valve leaflets. To establish a biomimetic TEHV model, we employed melt-electrowriting (MEW) technology to fabricate an anisotropic PCL scaffold. By integrating the anisotropic MEW-PCL scaffold with bioactive hydrogels (GelMA/ChsMA), we successfully crafted an elastic scaffold with tunable mechanical properties closely mirroring the structure and mechanical characteristics of natural heart valves. This scaffold not only supports the growth of valvular interstitial cells (VICs) within a 3D culture but also fosters the remodeling of extracellular matrix of VICs. The in vitro experiments demonstrated that the introduction of ChsMA improved the hemocompatibility and endothelialization of TEHV scaffold. The in vivo experiments revealed that, compared to their non-hydrogel counterparts, the PCL-GelMA/ChsMA scaffold, when implanted into SD rats, significantly suppressed immune reactions and calcification. In comparison with the PCL scaffold, the PCL-GelMA/ChsMA scaffold exhibited higher bioactivity and superior biocompatibility. The amalgamation of MEW technology and biomimetic design approaches provides a new paradigm for manufacturing scaffolds with highly controllable microstructures, biocompatibility, and anisotropic mechanical properties required for the fabrication of TEHVs.

BackgroundFasting blood glucose (FBG) variability, an emerging marker of glycemic control, has been shown to be related to the risk of cardiovascular events and all-cause mortality in subjects with or without diabetes. However, whether FBG variability is independently associated with a higher all-cause mortality in heart transplant recipients remains unknown. MethodsWe performed a retrospective cohort study including 373 adult recipients who survived for at least 1 year after heart transplantation with a functioning graft and measured FBG more than three times within first year after transplantation. Multivariable adjusted Cox regression analyses were performed to assess the association between FBG variability and all-cause mortality. ResultsPatients were categorized into three groups according to the coefficient of variation of FBG level: <= 7.0%, 7.0%-13.5%, and >13.5%. During a median follow-up of 44.4 months (interquartile range [IQR], 22.6-63.3 months), 31 (8.3%) participants died. In univariate analyses, FBG variability was associated with an increased all-cause mortality (hazard ratio [HR]: 3.00, 95% confidence interval [CI]: 1.67, 5.38; p < .001). This association remained materially unchanged in the multivariable model adjusted for components of demographics, cardiovascular history and lifestyle, hospital information, immunosuppressive therapy, and post-transplant renal function (HR: 2.75, 95% CI: 1.43, 5.28; p = .004). ConclusionsAfter heart transplantation, high FBG variability is strongly and independently associated with an increased risk of all-cause mortality. Our findings suggest that FBG variability is a novel risk factor and prognostic marker for heart transplantation recipients in outpatient clinic.

Hydrogen peroxide (H2O2) is an important chemical with a diverse array of applications. However, the existing scenario of centralized high-concentration production is in contrast with the demand for low-concentration decentralized production. In this context, the on-site green and efficient two-electron oxygen reduction reaction (ORR) for H2O2 production has developed into a promising synthetic approach. The development of low-cost, highly active, and durable advanced catalysts is the core requirement for realizing this approach. In recent years, single-atom catalysts (SACs) have become a research hotspot owing to their maximum atom utilization efficiency, tunable electronic structure, and exceptional catalytic performance. The coordination engineering of SACs is one of the key strategies to unlock their full potential for electrocatalytic H2O2 synthesis and holds significant research value. Despite considerable efforts, precisely controlling the electronic structure of active sites in SACs remains challenging. Therefore, this review summarizes the latest progress in coordination engineering strategies for SACs, aiming to elucidate the relevance between structure and performance. Our goal is to provide valuable guidance and insights to aid in the design and development of high-performance SACs for electrocatalytic H2O2 synthesis.

Developing high-efficiency and cost-effective electrocatalysts for oxygen evolution reaction (OER) is crucial for hydrogen production from electrolysis. Herein, a facile and universal strategy for fabricating organophosphorus (OP) layer encapsulated layered double hydroxide (LDH) is proposed for robust freshwater/seawater oxidation. This approach is based on a self-growing strategy using phytic acid (PA) to realize superb OER activity due to the electron transfer from metal ions in LDH to the phosphate groups in the OP layer. The phosphate group enriched OP layer can also efficiently avoid chloride corrosion via “physical blocking” and “electrostatic repelling”, enabling the OP-NiCo-LDH catalyst to show durable seawater oxidation catalysis performance. It requires an overpotential of 330 mV to deliver a 500 mA cm-2 seawater oxidation with excellent durability for 500 h. Moreover, only 1.59 V is required to achieve a 500 mA cm-2 overall seawater splitting for OP-NiCo-LDH||NiMoN cell. The refore, this work provides a strategy to design robust OER catalysts for industrial water/seawater electrolysis.