Three‐dimensional (3D) networks of graphitic carbon are promising materials for energy storage and conversion devices because of their high electrical conductivity, which is promoted by the good ...interconnection between the carbon particles. However, it is still difficult to directly synthesize such carbon networks. Herein, we report the novel synthesis of 3D graphitic carbon networks through the pyrolysis of nanosized ZIF‐67 crystals. Interestingly, the unusual effect of downsizing the ZIF‐67 crystals and the incorporation of catalytic Co nanoparticles was the spontaneous formation of graphitic networks. The obtained graphitic carbon networks show excellent electrochemical performance for the insertion and extraction of potassium ions.
Networking skills: A facile method has been developed to synthesize continuous 3D carbon networks by pyrolysis of nanosized metal‐organic frameworks (MOFs). The synthesized continuous 3D carbon networks show excellent electrochemical performance for potassium‐ion batteries, with long cycling stability and good capacity retention at high rates.
Metal cyanide coordination compounds are recognized as promising candidates for broad applications because of their tailorable and adjustable frameworks. Developing the nanostructure of a ...coordination compound may be an effective way to enhance the performance of that material in application‐based roles. A controllable preferential etching method is described for synthesis of monocrystalline Prussian blue analogue (PBA) nanoframes, without the use of organic additives. The PBA nanoframes show remarkable rate performance and cycling stability for sodium/lithium ion insertion/extraction.
A preferential etching method is reported for the synthesis of monocrystalline nanoframes of a Prussian blue analogue, without use of organic additives. The nanoframes showed remarkable rate performance and cycling stability as a cathode material for alkaline ion batteries.
This paper designs a novel adaptive robust optimal sliding mode control (SMC) strategy for constrained input missile system with uncertain input and unknown disturbance. First, a smooth function is ...employed to map the constrained input. Based on SMC theory, a fast adaptive SMC scheme is designed to reduce the effects of unknown input and approximate error which has two advantages. One is that the proposed scheme is independent of the uncertain information. The other is that the proposed scheme forces the states to converge with exponential rate as they are far away from the sliding mode surface, and the states move with linear rate when they are closed to the sliding mode surface. Then, a zero-sum differential games strategy-based adaptive dynamic programming (ADP) technique is employed to obtain the optimal performance of sliding mode dynamics system. The loop-system and estimation weight error can be proved stable by utilising Lyapunov theory. Finally, the missile autopilot system is used to indicate the effectiveness of the designed approach.
Electrocatalytic oxidation of organics using water as the oxygen source is a prospective but challenging method to produce high‐value‐added chemicals; especially, the competitive oxygen evolution ...reaction (OER) limits its efficiency. Herein, a tandem catalysis strategy based on a single‐atom catalyst with Cr atoms atomically dispersed at a CoSe2 support (Cr1/CoSe2) is presented. Thereinto, Co and Cr sites are endowed with a specific function to activate water and styrene respectively, and the competition between the OER and styrene oxidation is turned into mutual benefits via cooperated active sites. Under a potential of 1.6 VAg/AgCl, excellent selectivity of 95% to benzaldehyde and a high conversion rate of styrene at 88% without any exogenous oxidizing reagent are achieved. Isotopic tracing, isotope‐labeled in situ Raman spectra, and detailed theoretical calculation further reveal the tandem mechanism, showing that the transfer of *OOH intermediates from the Co to the Cr sites serves as a bridge to link the oxidation of water and styrene. This work develops a new strategy for the co‐oxidation of multi‐species based on tandem catalysis, providing novel insights for the design of single‐atom catalysts.
A tandem oxidation strategy based on a Co–Cr cooperated single‐atom Cr1/CoSe2 electrocatalyst is presented, turning the competition between the oxygen evolution reaction and styrene oxidation into mutual benefits via the migration of the *OOH intermediate from the Co to the Cr site, achieving an efficient and mild selective oxidation of styrene without any exogenous oxidizing reagent.
Based on the material property exhibiting a sublinear dependence of friction on load, a new mechanism of texturing for friction reduction has been identified and explored. In this, the nominal ...contact area is reduced by textures, the load of the non-concave area thus increases, and the friction coefficient is reduced by the sublinear dependence. Non-textured and textured samples were tested by a reciprocating tribometer to obtain the friction coefficient between polytetrafluoroethylene (PTFE) and steel. An empirical equation for the sublinear dependence was found, and used in a numerical mixed lubrication model to evaluate the mechanism. The results show that this mechanism explains well for the friction reduction of textured surface in dry conditions, and is still beneficial under mixed lubrication.
•A new mechanism of texturing for friction reduction is identified, and explored under dry/mixed lubrication conditions.•In this, texturing is used to artificially control the contact pressure distribution, and achieve a lower friction.•This mechanism explains well for the friction reduction of textured surface in dry conditions.•A numerical model is established to evaluate the friction reduction from this mechanism under mixed lubrication.•This mechanism may supplement the hydrodynamic theory to design the texturing appliable in multi lubrication conditions.
A novel tri‐culture model for neuroinflammation Zheng, Yan‐Fang; Zhou, Xian; Chang, Dennis ...
Journal of neurochemistry,
January 2021, 2021-01-00, 20210101, Letnik:
156, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Neuroinflammation is believed to play a primary role in the pathogenesis of most neurodegenerative diseases including Alzheimer's disease, Parkinson's disease and schizophrenia. Currently, suitable ...in vitro neuroinflammation models for studying cellular interactions and inflammatory mechanisms at the neurovascular unit are still scarce. In this study, we established an experimentally flexible tri‐culture neuroinflammation model combining murine microglial cells (N11), mouse neuroblastoma Nuro2A cell lines and brain microvascular endothelial MVEC(B3) cells in a transwell co‐culture system stimulated with lipopolysaccharides. Neuroinflammation was induced in this tri‐culture model as manifested by activated N11 cells via toll‐like receptor 4, resulting in increased release of proinflammatory mediators (nitric oxide, interleukin‐6 and tumour necrosis factor‐α) through the activation of nuclear factor‐κB signalling pathway. The released inflammatory cytokines from N11 in turn, damaged the tight junction in microvascular endothelial MVEC(B3) cells, increased permeability of endothelial barrier, and induced tau phosphorylation and up‐regulated caspase‐3 expression in mouse neuroblastoma Nuro2A cell lines, leading to neuroinflammation injury. In summary, this tri‐culture inflammation model mimics the microenvironment, the cellular crosstalk and the molecular events that take place during neuroinflammation. It provides a robust in vitro model for studying neuroinflammation mechanisms and screening for potential therapeutics to treat various neurodegenerative diseases.
We have established a novel neuroinflammation tri‐culture model that combines N11 microglia, N2A neurons and brain endothelial MVEC (B3) cells in a transwell tri‐culture system under the stimulation of lipopolysaccharides. By binding to the toll‐like receptor 4, lipopolysaccharides provoked IKK‐NFκB pathway which triggered the release of pro‐inflammatory mediators, and that diminished the endothelial barrier and induced tau phosphorylation and caspase‐3 expressions in neurons. We believe this experimentally flexible tri‐culture model mimicking the microvascular unit in vivo and could be extensively used for drug screening and discovery for potential therapeutic compounds against neuroinflammation induced neurodegenerative diseases.
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We report on buckling structures observed on tantalum films deposited by sputtering on silicon wafers. It is shown that, above a critical diameter, the circular blisters evolve to ...ring-shaped buckles, whatever the smooth or undulating type of their edges. The experimental results have been compared to finite element simulations. In particular, the polygonal collapsed part at the center of the buckles can be well understood by taking into account the pressure mismatch between the inside and outside parts of the buckles.
The poly(butylene succinate) (PBS) copolyesters modified by 2‐methyl‐1,3‐propanediol (MPO), that is poly(butylene succinate‐co‐methyl propylene succinate) (PBMS), were synthesized by direct ...esterification‐melt polycondensation method. 1H NMR showed the PBMS molecules contain two repeating structural units, the butylene succinate (BS) and the 2‐methyl‐1,3‐propylene succinate (MS). The crystalline properties of PBMS were characterized by DSC, POM, and XRD. The results showed the relative crystallinity of PBMS decreases from 45.12% to 38.2%, the size of spherulites also decreases, and the crystallization ability becomes weaker compared with PBS. The water contact angle test proved the surface hydrophilicity of PBMS is improved. The impact strength of PBMS increases from 3.9 to 24.6 kJ/m2, and its elongation at break increases from 10.5% to 71.2%, and the transition from brittle fracture to ductile fracture is achieved. The study of enzymatic degradation found that the enzymatic degradation rate of PBMS copolyesters increases significantly with the increase of MPO content. Within 25 days of degradation, the weight loss rate of PBS after degradation is 38.18%, while that of PBMS reaches 100%. Finally, it was also observed the enzymatic degradation of PBS and PBMS starts from the amorphous region and abides by the regular pattern from the periphery to the middle and from the surface to the interior.
Synthetic pathway of PBMS, enzymatic degradation rate, and surface morphology during degradation of PBS and PBMS.
Hepatocyte tight junctions (TJ) constituted blood–biliary barrier is the most important hepatic barrier for separating bile from the bloodstream, disruption or dysfunction of TJ barrier is involved ...in hepatobiliary manifestations of colitis, but the underlying mechanism is still not clear. This study aims to investigate the effect and underlying mechanism of tumor necrosis factor alpha (TNF-α) on hepatic TJ protein expression in blood–biliary barrier and identify its role in the pathogenesis of acute colitis-related cholestasis. Acute colitis rat model was induced by trinitrobenzene sulfonic acid (TNBS) intra-colonic administration. TJs expression of blood–biliary barrier was tested in colitis rats, the serum TNF-α level was also determined in order to elucidate the correlation of TNF-α and TJs. HepaRG cells were used to investigate the effect of TNF-α on TJs, and the phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signaling pathway were also evaluated in rats and TNF-α treated HepaRG cells. Acute colitis was induced in rats at 5 d post TNBS, which is accompanied with cholestasis-like alteration. Serum TNF-α level was increased in colitis rats and positively correlated with the alteration of total bile acids and bilirubin, marked decrease in TJs was found in TNF-α treated HepaRG cells and the rats, down-regulated PI3K/AKT signaling pathway were also identified in TNF-α treated HepaRG cells and the rats. The study concluded that serum TNF-α mediated the down-regulation of PI3K/AKT signaling pathway, which contributed to the reduction of TJ protein expression in acute colitis-related intrahepatic cholestasis. These findings suggest that TNF-α plays an important role in the pathogenesis of intrahepatic cholestasis of colitis.
The objective of this investigation is to analyze the levels and clinical relevance of serum PYCARD (Pyrin and CARD domain-containing protein, commonly known as ASC-apoptosis-associated speck-like ...protein containing a caspase activation and recruitment domain), interleukin-38 (IL-38), and interleukin-6 (IL-6) in individuals afflicted with rheumatoid arthritis (RA).
Our study comprised 88 individuals diagnosed with RA who sought medical attention at the Affiliated Hospital of Chengde Medical University during the period spanning November 2021 to June 2023, constituting the test group. Additionally, a control group of 88 individuals who underwent health assessments at the same hospital during the aforementioned timeframe was included for comparative purposes. The study involved the assessment of IL-38, IL-6, PYCARD, anti-cyclic citrullinated peptide antibody (anti-CCP), and erythrocyte sedimentation rate (ESR) levels in both groups. The research aimed to explore the correlations and diagnostic efficacy of these markers, employing pertinent statistical analyses for comprehensive evaluation.
The test group had higher expression levels of PYCARD, IL-6, and IL-38 than the control group (P < 0.05). Based on the correlation analysis, there was a strong relationship between PYCARD and IL-38 (P < 0.01). The receiver operating characteristic (ROC) curve analysis revealed area under the curve (AUC) values of 0.97, 0.96, and 0.96 when using combinations of PYCARD and anti-CCP, IL-38 and anti-CCP, and IL-6 and anti-CCP for predicting RA, respectively. Importantly, all three of these pairs demonstrated superior AUC values compared to PYCARD, IL-38, IL-6, ESR, or anti-CCP used as standalone diagnostic indicators.
PYCARD, IL-6, and IL-38 exhibit promising potential as novel diagnostic markers and may constitute valuable tools for supporting the diagnosis of RA.
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