Solid oxide cells (SOCs) have the potential to be the most efficient energy storage and conversion systems. To minimize energy loss due to charge and mass transport associated with the operation of ...SOC systems at intermediate temperatures, electrodes and electrolytes containing different types of heterointerfaces have been designed, fabricated, and tested under various conditions. While heterointerfaces can significantly enhance not only the ionic and/or electronic conductivity but also the electrocatalytic activity and stability of SOC components, as predicted by theoretical calculations and demonstrated by experimental results, the mechanisms of these enhancements are yet to be fully understood. In this review, we start with an overview of the techniques for fabrication of heterointerfaces with controlled composition, structure, and morphology. Then, the latest developments in performance enhancement of SOCs with heterointerfaces are summarized, including boosting the ionic conductivity of heterostructured electrolytes (oxygen ion conductors and proton conductors) and increasing the electrocatalytic activity and durability of heterostructured electrodes (oxygen electrodes and fuel electrodes). Subsequently, we will highlight the unique attributes of heterointerfaces in the enhancement of the SOC performance and provide important insights into the mechanisms of performance enhancement in order to establish the scientific basis for rational design of better electrolyte and electrode materials. Finally, the remaining challenges in design and fabrication of novel materials for advanced solid-state electrochemical systems will be discussed, together with possible strategies to overcome these critical issues, new research directions, and future perspectives.
This article overviews the latest developments in enhancing the conductivity, electro-catalytic activity, and stability of SOC materials through heterointerface engineering.
The rational design and synthesis of nonprecious, efficient, and stable electrocatalysts to replace precious noble metals are crucial to the future of hydrogen economy. Herein, a partial ...sulfurization/phosphorization strategy is proposed to synthesize a nonstoichiometric pyrrhotite-type cobalt monophosphosulfide material (Co0.9S0.58P0.42) with a hexagonal close-packed phase for electrocatalytic water splitting. By regulating the degree of sulfurization, the P/S atomic ratio in the cobalt monophosphosulfide can be tuned to activate the Co3+/Co2+ couples. The synergy between the nonstoichiometric nature and the tunable P/S ratio results in the strengthened Co3+/Co2+ couples and tunable electronic structure and thus efficiently promotes the oxygen/hydrogen evolution reaction (OER/HER) processes toward overall water splitting. Especially for OER, the Co0.9S0.58P0.42 material, featured with a uniform yolk–shell spherical morphology, shows a low overpotential of 266 mV at 10 mA cm–2 (η10) with a low Tafel slope of 48 mV dec–1 as well as high stability, which is comparable to that of the reported promising OER electrocatalysts. Coupled with the high HER activity of Co0.9S0.58P0.42, the overall water splitting is demonstrated with a low η10 at 1.59 V and good stability. This study shows that phase engineering and composition control can be the elegant strategy to realize the Co3+/Co2+ couple activation and electronic structure tuning to promote the electrocatalytic process. The proposed strategy and approaches allow the rational design and synthesis of transition metal monophosphosulfides toward advanced electrochemical applications.
A critical shortage of donor organs for treating end-stage organ failure highlights the urgent need for generating organs from human induced pluripotent stem cells (iPSCs). Despite many reports ...describing functional cell differentiation, no studies have succeeded in generating a three-dimensional vascularized organ such as liver. Here we show the generation of vascularized and functional human liver from human iPSCs by transplantation of liver buds created in vitro (iPSC-LBs). Specified hepatic cells (immature endodermal cells destined to track the hepatic cell fate) self-organized into three-dimensional iPSC-LBs by recapitulating organogenetic interactions between endothelial and mesenchymal cells. Immunostaining and gene-expression analyses revealed a resemblance between in vitro grown iPSC-LBs and in vivo liver buds. Human vasculatures in iPSC-LB transplants became functional by connecting to the host vessels within 48 hours. The formation of functional vasculatures stimulated the maturation of iPSC-LBs into tissue resembling the adult liver. Highly metabolic iPSC-derived tissue performed liver-specific functions such as protein production and human-specific drug metabolism without recipient liver replacement. Furthermore, mesenteric transplantation of iPSC-LBs rescued the drug-induced lethal liver failure model. To our knowledge, this is the first report demonstrating the generation of a functional human organ from pluripotent stem cells. Although efforts must ensue to translate these techniques to treatments for patients, this proof-of-concept demonstration of organ-bud transplantation provides a promising new approach to study regenerative medicine.
Indole is prevalent in bioactive compounds and natural products. The development of efficient and sustainable methods to access this privileged structural scaffold has been a long-standing interest ...of synthetic chemists. Herein, we report an electrocatalytic method for the synthesis of indoles through dehydrogenative cyclization of 2-vinylanilides. The reactions employ an organic redox catalyst and do not require any external chemical oxidant, providing speedy and efficient access to 3-substituted and 2,3-disubstituted indoles.
The 1,2-diamine motif is prevalent in natural products, small-molecule pharmaceuticals, and catalysts for asymmetric synthesis. Transition metal catalyzed alkene diazidation has evolved to be an ...attractive strategy to access vicinal primary diamines but remains challenging, especially for practical applications, due to the restriction to a certain type of olefins, the frequent use of chemical oxidants, and the requirement for high loadings of metal catalysts (1 mol % or above). Herein we report a scalable Cu-electrocatalytic alkene diazidation reaction with 0.02 mol % (200 ppm) of copper(II) acetylacetonate as the precatalyst without exogenous ligands. In addition to its use of low catalyst loading, the electrocatalytic method is scalable, compatible with a broad range of functional groups, and applicable to the diazidation of α,β-unsaturated carbonyl compounds and mono-, di-, tri-, and tetrasubstituted unactivated alkenes.
To fully decipher the immunogenicity of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Spike protein, it is essential to assess which part is highly immunogenic in a systematic way. ...We generate a linear epitope landscape of the Spike protein by analyzing the serum immunoglobulin G (IgG) response of 1,051 coronavirus disease 2019 (COVID-19) patients with a peptide microarray. We reveal two regions rich in linear epitopes, i.e., C-terminal domain (CTD) and a region close to the S2′ cleavage site and fusion peptide. Unexpectedly, we find that the receptor binding domain (RBD) lacks linear epitope. We reveal that the number of responsive peptides is highly variable among patients and correlates with disease severity. Some peptides are moderately associated with severity and clinical outcome. By immunizing mice, we obtain linear-epitope-specific antibodies; however, no significant neutralizing activity against the authentic virus is observed for these antibodies. This landscape will facilitate our understanding of SARS-CoV-2-specific humoral responses and might be useful for vaccine refinement.
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•A linear epitope landscape of the SARS-CoV-2 Spike from 1,051 COVID-19 patients•Responsive epitopes are highly variable among patients and correlate with severity•The RBD lacks linear epitopes, but two other regions are rich in linear epitopes•Little neutralization activity is observed for the linear-epitope-elicited antibodies
Li et al. construct a B cell linear epitope landscape of SARS-CoV-2 Spike protein, based on a large cohort of COVID-19 patients. The epitope responses were related to disease severity and outcome but mainly elicit non-neutralizing antibodies.
•Proposes the WA-FMCGP model, hybridising FGP, MCGP and WGP by taking a novel FGP+MCGP approach.•Validates the model using an exemplar in F-MODM literature having decision contexts with imprecise ...goals.•Compares the results with those using FP+MCGP modelling approach; identifies positive consequences of using FGP+MCGP.•Supports empirical decisions of selecting the best location for wind-farm expansion using meta WA-FMCGP.•Provides F-MODM methods for renewable-energy site-selection (RESS), compared to the MADM models used thus far.
This paper proposes a novel weighted-additive fuzzy multi-choice goal programming (WA-FMCGP) model for the imprecise decision context wherein several conflicting goals are present but each goal has multiple-choice aspiration levels (MCALs) and, around them, the fuzzinesses are expressed in terms of membership functions (MFs). The main contribution of this model is its use of an objective function that minimises the weighted-additive summation of the normalised deviations; thus, the model can adopt any minimisation process from any goal programming (GP) variant. The advantages of this FGP-MCGP (fuzzy GP – multi-choice GP) model are shown by using it to solve a numerical example from F-MODM (fuzzy MODM) literature and comparing the results with those of a recent FP-MCGP (fuzzy programming – multi-choice GP) study. The application of the model is also verified using real data (i.e., it can model and support renewable energy site selection (RESS) where the decision context is imprecise). As WA-FMCGP is largely a MODM model, through its application, this study also provides a supplementary method in contrast to the multi-attribute decision-making (MADM) model applications used thus far for RESS.
Vascular endothelial growth factor (VEGF-A or VEGF) is a major pathogenic factor and therapeutic target for diabetic retinopathy (DR). Since VEGF has been proposed as a survival factor for retinal ...neurons, defining the cellular origin of pathogenic VEGF is necessary for the effectiveness and safety of long-term anti-VEGF therapies for DR. To determine the significance of Müller cell-derived VEGF in DR, we disrupted VEGF in Müller cells with an inducible Cre/lox system and examined diabetes-induced retinal inflammation and vascular leakage in these conditional VEGF knockout (KO) mice.
Leukostasis was determined by counting the number of fluorescently labeled leukocytes inside retinal vasculature. Expression of biomarkers for retinal inflammation was assessed by immunoblotting of TNF-alpha, ICAM-1, and NF-kappaB. Vascular leakage was measured by immunoblotting of retinal albumin and fluorescent microscopic analysis of extravascular albumin. Diabetes-induced vascular alterations were examined by immunoblotting and immunohistochemistry for tight junctions, and by trypsin digestion assays for acellular capillaries. Retinal integrity was analyzed with morphologic and morphometric analyses.
Diabetic conditional VEGF KO mice exhibited significantly reduced leukostasis, expression of inflammatory biomarkers, depletion of tight junction proteins, numbers of acellular capillaries, and vascular leakage compared to diabetic control mice.
Müller cell-derived VEGF plays an essential and causative role in retinal inflammation, vascular lesions, and vascular leakage in DR. Therefore, Müller cells are a primary cellular target for proinflammatory signals that mediates retinal inflammation and vascular leakage in DR.
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