Recent studies found that the circulating high-mobility group box 1 (HMGB1) levels could reflect the disease activity of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). HMGB1 ...could prime neutrophils by increasing ANCA antigens translocation for ANCA-mediated respiratory burst and degranulation. The current study aimed to investigate whether HMGB1 participates in ANCA-induced neutrophil extracellular traps (NETs) formation, which is one of the most important pathogenic aspects in the development of AAV.
NETs were induced by treating neutrophils with HMGB1 and ANCA-positive IgG in vitro. NETs formation was assessed using immunofluorescence microscopy and fluorescence probe. Antagonist for relevant receptors Toll-like receptor (TLR)2, TLR4 and the receptor for advanced glycation end products (RAGE), as well as NADPH oxidase molecules were employed.
The percentage of NETs formation was significantly higher in neutrophils stimulated with HMGB1 plus ANCA-positive IgG than that in neutrophils incubated with HMGB1 or ANCA-positive IgG alone. Consistently, compared with the nonstimulated neutrophils, the cell-free DNA (cfDNA) concentration of NETs was significantly increased from 334.09 ± 46.89 ng/ml to 563.32 ± 122.07 ng/ml in the neutrophils incubated with HMGB1 plus MPO-ANCA-positive IgG (P < 0.001), and from 303.44 ± 37.14 ng/ml to 563.79 ± 145.94 ng/ml in the neutrophils incubated with HMGB1 plus PR3-ANCA-positive IgG (P < 0.001). The aforementioned effect was significantly attenuated by antagonist for relevant receptors TLR2, TLR4 and RAGE, as well as blocking NADPH oxidase.
HMGB1 can potentiate ANCA-inducing NETs formation and may be involved in the pathogenesis of AAV. HMGB1 exerts effects on NETs formation through interaction with TLR2, TLR4 and RAGE, and the process is NADPH oxidase dependent.
Photocatalytic hydrogen production is crucial for solar‐to‐chemical conversion process, wherein high‐efficiency photocatalysts lie in the heart of this area. A photocatalyst of hierarchically ...mesoporous titanium phosphonate based metal–organic frameworks, featuring well‐structured spheres, a periodic mesostructure, and large secondary mesoporosity, are rationally designed with the complex of polyelectrolyte and cathodic surfactant serving as the template. The well‐structured hierarchical porosity and homogeneously incorporated phosphonate groups can favor the mass transfer and strong optical absorption during the photocatalytic reactions. Correspondingly, the titanium phosphonates exhibit significantly improved photocatalytic hydrogen evolution rate along with impressive stability. This work can provide more insights into designing advanced photocatalysts for energy conversion and render a tunable platform in photoelectrochemistry.
A multi‐structured photocatalyst: A metal–organic framework (MOF) nanostructure synthesized by a surfactant‐directed strategy features a stable framework of titanium phosphates, a well‐defined sphere, and hierarchical nanopores. These features ensure competitive photoactivity in evolving hydrogen under both visible light and full‐spectrum simulator irradiation, along with high durability.
Rational design and exploration of robust and low‐cost bifunctional oxygen reduction/evolution electrocatalysts are greatly desired for metal–air batteries. Herein, a novel high‐performance oxygen ...electrode catalyst is developed based on bimetal FeCo nanoparticles encapsulated in in situ grown nitrogen‐doped graphitic carbon nanotubes with bamboo‐like structure. The obtained catalyst exhibits a positive half‐wave potential of 0.92 V (vs the reversible hydrogen electrode, RHE) for oxygen reduction reaction, and a low operating potential of 1.73 V to achieve a 10 mA cm−2 current density for oxygen evolution reaction. The reversible oxygen electrode index is 0.81 V, surpassing that of most highly active bifunctional catalysts reported to date. By combining experimental and simulation studies, a strong synergetic coupling between FeCo alloy and N‐doped carbon nanotubes is proposed in producing a favorable local coordination environment and electronic structure, which affords the pyridinic N‐rich catalyst surface promoting the reversible oxygen reactions. Impressively, the assembled zinc–air batteries using liquid electrolytes and the all‐solid‐state batteries with the synthesized bifunctional catalyst as the air electrode demonstrate superior charging–discharging performance, long lifetime, and high flexibility, holding great potential in practical implementation of new‐generation powerful rechargeable batteries with portable or even wearable characteristic.
Bamboo‐like FeCo alloy encapsulated in nitrogen‐doped carbon nanotubes exhibits superior catalytic oxygen reduction and oxygen evolution performance than that of noble metal benchmarks, which benefits from the nitrogen‐rich and defect‐rich catalyst surface. The all‐solid‐state zinc–air batteries equipped by the synthesized materials show low charging/discharging overpotentials, long lifetime, and high flexibility, suitable for practical application.
Tuning the catalytic active sites plays a crucial role in developing low cost and highly durable oxygen electrode catalysts with precious metal‐competitive activity. In an attempt to engineer the ...active sites in Co3O4 spinel for oxygen electrocatalysis in alkaline electrolyte, herein, controllable synthesis of surface‐tailored Co3O4 nanocrystals including nanocube (NC), nanotruncated octahedron (NTO), and nanopolyhedron (NP) anchored on nitrogen‐doped reduced graphene oxide (N‐rGO), through a facile and template‐free hydrothermal strategy, is provided. The as‐synthesized Co3O4 NC, NTO, and NP nanostructures are predominantly enclosed by {001}, {001} + {111}, and {112} crystal planes, which expose different surface atomic configurations of Co2+ and Co3+ active sites. Electrochemical results indicate that the unusual {112} plane enclosed Co3O4 NP on rGO with abundant Co3+ sites exhibit superior bifunctional activity for oxygen reduction and evolution reactions, as well as enhanced metal–air battery performance in comparison with other counterparts. Experimental and theoretical simulation studies demonstrate that the surface atomic arrangement of Co2+/Co3+ active sites, especially the existence of octahedrally coordinated Co3+ sites, optimizes the adsorption, activation, and desorption features of oxygen species. This work paves the way to obtain highly active, durable, and cost‐effective electrocatalysts for practical clean energy devices through regulating the surface atomic configuration and catalytic active sites.
An unusual {112} facet enclosed Co3O4 nanopolyhedron supported on N‐doped graphene exhibits superior oxygen reduction reaction/oxygen evolution reaction bifunctional and Zn–air battery performance than those of {100} and {100} + {111} surrounded Co3O4 nanocubes and nanotruncated octahedron owning to the unique surface atomic configuration of Co2+/Co3+ active sites, which favors the adsorption, activation of oxygen species, and the kinetics of O22−/OH− displacement.
ZnCo2O4 quantum dots anchored on nitrogen‐doped carbon nanotubes (N‐CNT) retain the high catalytic activity of ZnCo2O4 to oxidize water while enabling an efficient oxygen reduction performance ...thereby combining these desirable features. These advantages realize a bifunctional catalytic activity for ZnCo2O4/N‐CNT that can be used in rechargeable zinc–air batteries.
A new class of highly efficient oxygen evolution catalysts has been synthesized through the self‐assembly of graphitic carbon nitride nanosheets and carbon nanotubes, driven by π–π stacking and ...electrostatic interactions. Remarkably, the catalysts exhibit higher catalytic oxygen evolution activity and stronger durability than Ir‐based noble‐metal catalysts and display the best performance among the reported nonmetal catalysts. This good result is attributed to the high nitrogen content and the efficient mass and charge transfer in the porous three‐dimensional nanostructure.
Combining C and N to make O: 3D porous graphitic carbon nitride nanosheet–carbon nanotube composites have been synthesized through a spontaneous assembly process. The high nitrogen content, enhanced electron conductivity, and improved mass transport result in excellent catalytic oxygen evolution activity and strong durability, superior to those reported for other nonmetal catalysts and noble‐metal catalysts (see figure; OER: oxygen evolution reaction).
Abstract
Scalable and sustainable solar hydrogen production through photocatalytic water splitting requires highly active and stable earth-abundant co-catalysts to replace expensive and rare ...platinum. Here we employ density functional theory calculations to direct atomic-level exploration, design and fabrication of a MXene material, Ti
3
C
2
nanoparticles, as a highly efficient co-catalyst. Ti
3
C
2
nanoparticles are rationally integrated with cadmium sulfide via a hydrothermal strategy to induce a super high visible-light photocatalytic hydrogen production activity of 14,342 μmol h
−1
g
−1
and an apparent quantum efficiency of 40.1% at 420 nm. This high performance arises from the favourable Fermi level position, electrical conductivity and hydrogen evolution capacity of Ti
3
C
2
nanoparticles. Furthermore, Ti
3
C
2
nanoparticles also serve as an efficient co-catalyst on ZnS or Zn
x
Cd
1−
x
S. This work demonstrates the potential of earth-abundant MXene family materials to construct numerous high performance and low-cost photocatalysts/photoelectrodes.
Atomically and electronically coupled Pt and CoO hybrid nanocatalysts are fabricated for electrocatalytic oxygen reduction reaction. The atomic coupling between the Pt and the CoO endows precise ...control of the atomic interface between the Pt and the CoO, which directly results in electron donation from the CoO to the Pt, and thus favorable tuning of the electronic structure of the Pt.
Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a group of life-threatening disorders, and frequently affects the kidneys. This study investigated whether the circulating ...neutrophil extracellular traps (NETs) levels were associated with disease activity of AAV. We collected serum samples from 34 patients with AAV in active stage and 62 patients with AAV in remission. Cell free DNA in serum was quantified using the Quant-iT PicoGreen assay. NETs associated MPO-DNA complexes, citrullinated-histone H3-DNA (cit-H3-DNA) complexes and the concentration of deoxyribonuclease I (DNase I) were quantified using ELISA. The activity of DNase I was quantified using radial enzyme-diffusion method. Associations between circulating levels of NETs with clinico-pathological parameters were analyzed. Serum levels of NETs in active AAV patients were significantly higher than those in healthy controls, and the level of cell free DNA correlated with C-reactive protein (CRP). However, no correlation was found between MPO-DNA complexes or cit-H3-DNA complexes level and CRP. Also there was no significant correlation between NETs level and initial serum creatinine, estimated glomerular filtration rate (eGFR), crescents formation or Birmingham Vasculitis Activity Score (BVAS). Furthermore, there was no significant difference of serum levels of cell free DNA or MPO-DNA complexes between active stage and remission of AAV. In conclusion, circulating levels of NETs cannot be used as a biomarker to assess disease activity in AAV patients.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In spite of recent advances in the synthesis of hollow micro/nanostructures, the fabrication of three‐dimensional electrodes on the basis of these structures remains a major challenge. Herein, we ...develop an electrochemical sacrificial‐template strategy to fabricate hollow Co3O4 microtube arrays with hierarchical porosity. The resultant unique structures and integrated electrode configurations impart enhanced mass transfer and electron mobility, ensuring high activity and stability in catalyzing oxygen and hydrogen evolution reactions. Impressively, the apparent performance can rival that of state‐of‐the‐art noble‐metal and transition‐metal electrocatalysts. Furthermore, this bifunctional electrode can be used for highly efficient overall water splitting, even competing with the integrated performance of Pt/C and IrO2/C.
Hollow and hierarchical: An electrochemical self‐templating strategy was developed for the fabrication of hollow Co3O4 microtube arrays with hierarchical porosity. The resultant structures showed excellent electrocatalytic activity and durability towards oxygen and hydrogen evolution and are thus capable of catalyzing full water splitting.
PDF
