A series of S-allyl-l-cysteine (SAC) with garlic acid conjugates as anti-inflammatory agents were designed and synthesized. Among the 40 tested compounds, SMU-8c exhibited the most potent inhibitory ...activity to Pam3CSK4-induced nitric oxide (NO) in RAW264.7 macrophages with IC50 of 22.54 ± 2.60 μM. The structure-activity relationship (SAR) study suggested that the esterified carboxyl group, carbon chain extension and methoxylation phenol hydroxy could improve the anti-inflammatory efficacy. Preliminary anti-inflammatory mechanism studies showed that SMU-8c significantly down-regulated the levels of Pam3CSK4 triggered TNF-α cytokine in human THP-1 cells, mouse RAW 264.7 macrophages, as well as in ex-vivo human peripheral blood mononuclear cells (PBMC) with no influence on cell viability. SMU-8c specifically blocked the Pam3CSK4 ignited secreted embryonic alkaline phosphatase (SEAP) signaling with no influence to Poly I:C or LPS triggered TLR3 or TLR4 signaling. Moreover, SMU-8c suppressed TLR2 in HEK-Blue hTLR2 cells and inhibited the formation of TLR1-TLR2, and TLR2-TLR6 complex in human PBMC. In summary, SMU-8c inhibited the TLR2 signaling pathway to down-regulate the inflammation cytokines, such as NO, SEAP and TNF-α, to realize its anti-inflammatory activity.
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•Novel SAC-Garlic Acid natural product conjugates were designed and synthesized.•The optimized compound SMU-8c exhibit potent inhibition to TLR2, not TLR3 and TLR4.•SMU-8c inhibited the formation of TLR1-TLR2, and TLR2-TLR6 complex in human PBMC.•SMU-8c provides a novel molecule probe for anti-inflammatory applications.
Continuous capacity increase in electrochemical cycling, termed as electrochemical activation, is a frequently observed but rarely systematically studied phenomenon. Such phenomenon is noted in a ...preliminary study of carbon cathode for dual ion battery, showing gradual discharge capacity growth from 186 mAh g−1 (the 1st) to 320 mAh g−1 (the 300th). Systematical characterizations are carried out to investigate this phenomenon occurred on the carbon cathode, hydrothermally reduced graphene oxide (HrGO). The electrochemical activation comes from surface area increment, originated from multilayer reduced graphene oxide rolls formation and accumulation and structural order increase in cycling. The formation of rolls is plausibly a result of strain release of reduced graphene layers after electrochemical interaction with PF6−. Additionally, charge storage mechanism of HrGO is revealed. At active surface sites of HrGO, PF6− is consistently stored in a pseudocapacitive manner. In contrast, at well-crystallized domains, pseudocapacitive PF6− uptake occurs at low voltage region while PF6− intercalation dominates at higher potentials. Supportive lithium storage also contributes to total capacity. Comprehensively, this work offers valuable insights of electrochemical activation and carbon cathodes’ electrochemical behaviors and will facilitate the construction of high-capacity carbon cathodes.
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The binding of cell integrins to proteins adsorbed on the material surface is a highly dynamic process critical for guiding cellular responses. However, temporal dynamic regulation of adsorbed ...proteins to meet the spatial conformation requirement of integrins for a certain cellular response remains a great challenge. Here, an active CoFe2O4/poly(vinylidene fluoride-trifluoroethylene) nanocomposite film, which was demonstrated to be an obvious surface potential variation (ΔV ≈ 93 mV) in response to the applied magnetic field intensity (0–3000 Oe), was designed to harness the dynamic binding of integrin-adsorbed proteins by in situ controlling of the conformation of adsorbed proteins. Experimental investigation and molecular dynamics simulation confirmed the surface potential-induced conformational change in the adsorbed proteins. Cells cultured on nanocomposite films indicated that cellular responses in different time periods (adhesion, proliferation, and differentiation) required distinct magnetic field intensity, and synthetically programming the preferred magnetic field intensity of each time period could further enhance the osteogenic differentiation through the FAK/ERK signaling pathway. This work therefore provides a distinct concept that dynamically controllable modulation of the material surface property fitting the binding requirement of different cell time periods would be more conducive to achieving the desired osteogenic differentiation.
The highly porous electrode of a crisscrossed CoNi nanosheets array grown on reduced graphene oxide decorated Ni foam (CoNi/rGO@Ni foam) is fabricated through a facile dip and dry method followed by ...electroreduction and electrodeposition methods. The phase composition and morphology of the electrode are characterized by XRD, SEM, TEM, and EDS. In single electrode tests, CoNi/rGO@Ni foam electrode displays an excellent catalytic performance (330 mA cm−2 at 0.6 V) and stability towards urea electrooxidation when comparing to Ni foam and CoNi nanosheets modified Ni foam (CoNi@Ni foam) electrode. Besides, a low initial oxidation potential of urea electro-oxidation to 0.14 V is achieved on the CoNi/rGO@Ni foam electrode. The introducing of rGO to the electrode greatly reduced the reaction activation energy from 14.47 to 10.35 kJ mol−1. Besides, large active surface area (261.67 cm2) is also obtained from the electrode. The CoNi/rGO@Ni foam anode exhibits a maximum power density of 12.58 mW cm−2 in direct urea-hydrogen peroxide fuel cell tests. Excellent performance shows in single electrode tests and fuel cell tests suggest that addition of rGO to the electrode is an easy and feasible method to enhance the performance of the catalyst.
•Highly porous electrode: crisscrossed nanosheets array grows on rGO modified Ni foam.•The influence of rGO on the catalytic performance of the electrode was researched.•Low initial oxidation potential towards urea electro-oxidation was obtained.•Achieved an excellent performance and stability when practical use in DUHPFC.
•A gas foaming strategy is adopted to prepare the 3D hierarchical porous carbon.•NaHCO3 is used as activator based on its multistep pyrolysis process.•The HPC shows high specific capacitance and ...outstanding stability.
Inspired by people to make flour food, a one-pot, low-cost, green and environmental friendly gas foaming strategy is adopted here to prepare the three-dimensional hierarchical porous carbon (HPC) by introducing NaHCO3 as foaming and activation agent. During the pyrolysis process, the CO2 gas produced during the transforms from NaHCO3 into Na2CO3 will resulted in the producers of the macro-pores and meso-pores, meanwhile, the as-produced Na2CO3 further reactor with the carbon intermediate at a high temperature, and finally result in forming a micro-pores porous structure. Such intimate structural interconnectivities provide three-dimensional continuous pathway for electron rapid transfer and the interconnected pores allow for the ion to penetrate and evenly contact the electrode material quickly. The electrochemical performance of HPC exhibits a high specific capacitance of 350 F g−1 at 1 A g−1 and outstanding electrochemical stability with capacitance retention up to 97% after 10,000 cycles. Moreover, the as-assembled symmetric supercapacitor exhibits an ultrahigh energy density of 27.4 Wh kg−1, much higher than most of carbon-based supercapacitors. These results demonstrate a straightforward environment friendly method to mass-produce economical, robust carbon materials as promising candidates for supercapacitor application.
Fuel reforming is an attractive method for performance enhancement of internal combustion engines fueled by natural gas, since the syngas can be generated inline from the reforming process. In this ...study, 1D and 2D steady‐state modeling of exhaust gas reforming of natural gas in a catalytic fixed‐bed reactor were conducted under different conditions. With increasing engine speed, methane conversion and hydrogen production increased. Similarly, increasing the fraction of recirculated exhaust gas resulted in higher consumption of methane and generation of H2 and CO. Steam addition enhanced methane conversion. However, when the amount of steam exceeded that of methane, less hydrogen was produced. Increasing the wall temperature increased the methane conversion and reduced the H2/CO ratio.
Exhaust gas reforming is a fuel conversion technology that can enhance engine efficiency and reduce emissions in internal combustion engines. A catalytic reactor integrated in the exhaust recirculation loop uses exhaust heat and gas for on‐board production of hydrogen‐rich syngas. Herein, exhaust gas reforming of natural gas in a catalytic fixed‐bed reactor was modeled under different conditions.
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•A facile preparation of PDA/TiO2 composite films on polymeric substrate.•Strongly adhered films derived through capillary effect and PDA chemistry.•Effective light-induced cell sheet ...harvesting on PDA/TiO2 composite films.
This study presents a convenient and versatile way to prepare functionalized composite polydopamine/titanium dioxide (PDA/TiO2) film on polystyrene (PS). First, polystyrene substrate was immersed in dopamine chloride solution, and then collosol containing TiO2 and water was spun on it, to produce uniform, continuous PDA/TiO2 composite films. The thickness of film was controllable by adjustment of the spin speed. It was found that the films were strongly adhered on the PS substrate, with peel strength and shear strength of 2.78 MPa and 37.78 MPa, respectively. After 20 min of ultraviolet (365 nm) illumination, over 90% of fibroblasts and 77% of osteoblasts detached from the PDA/TiO2 composite film. Additionally, the detached cells showed good viability, allowing further culture and applications. This preparation method could be widely applied for cell and cell sheet harvesting directly from PS-based culture wares.
Production of CO-rich hydrogen gas from methane dry reforming was investigated over CeO2-supported Co catalyst. The catalyst was synthesized by wet impregnation and subsequently characterized by ...field emission scanning electron microscope (FESEM), energy dispersion X-ray spectroscopy (EDX), liquid N2 adsorption-desorption, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) for the structure, surface and thermal properties. The catalytic activity test of the Co/CeO2 was investigated between 923-1023 K under reaction conditions in a stainless steel fixed bed reactor. The composition of the products (CO2 and H2) from the methane dry reforming reaction was measured by gas chromatography (GC) coupled with thermal conductivity detector (TCD). The effects of feed ratios and reaction temperatures were investigated on the catalytic activity toward product selectivity, yield, and syngas ratio. Significantly, the selectivity and yield of both H2 and CO increases with feed ratio and temperature. However, the catalyst shows higher activity towards CO selectivity. The highest H2 and CO selectivity of 19.56% and 20.95% respectively were obtained at 1023 K while the highest yield of 41.98% and 38.05% were recorded for H2 and CO under the same condition.
An original three-dimensional self-supported reduced graphene oxide (rGO) foam is successfully prepared in this work. This novel support material, modified with Co nanosheets and Au nanoparticles, is ...employed as a high-performance catalyst for NaBH4 electrooxidation under alkaline condition. The surface chemical component and morphology of the catalyst is characterized by X-ray diffraction pattern, X-ray photoelectron spectroscopy, scanning electron microscope. The synthesized electrode exhibits excellent performance (1.35 A cm−2 at 0 V) towards NaBH4 electrooxidation. The unique structure of rGO foam caused a large electrochemical active surface area (EASA(Au) = 390 m2 g−1), low electrochemical impedance, as well as 55.4% utilization efficiency of NaBH4. Also, catalytic kinetic parameters during the electrooxidation reaction of NaBH4 in a low NaBH4 concentration are investigated. Results indicate that oxidation of BH4− is a first-order reaction, and the exchanged number of electrons obtained at the CoAu/rGO foam electrode is 6.9. Finally, we practically apply it to a direct borohydride-hydrogen peroxide fuel cell (DBHPFC). This work suggests that the prepared rGO foam is an excellent current collector, and CoAu/rGO foam electrode is a promising anode catalyst to apply in DBHPFC.
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The current paper reports on the kinetics of syngas production from glycerol pyrolysis over the alumina-supported nickel catalyst that was promoted with samarium, a rare earth element. The catalysts ...were synthesized via wet-impregnation method and its physicochemical properties were subsequently characterized. Reaction studies were performed in a 10 mm-ID stainless steel fixed bed reactor with reaction temperatures maintained at 973, 1023 and 1073 K, respectively, employing weight-hourly-space-velocity of 4.5 × 104 ml g−1 h−1. The textural property examination showed that BET specific surface area was 2.09 m2 g−1 for the unpromoted catalyst while the samarium promoted catalyst has 2.68 m2 g−1. Interestingly, the results were supported by the FESEM images which showed that the promoted catalyst has smaller particle size compared to the unpromoted catalyst. Furthermore, the NH3- and CO2-TPD analyses proved that the strong and weak acid-basic sites were present. During glycerol pyrolysis, the syngas was produced directly from the glycerol decomposition. This has created H2:CO ratios that were always lower than 2.0, which is suitable for Fischer-Tropsch synthesis. The activation energy based on power law modeling for the unpromoted catalyst was 35.8 kJ mol−1 and 23.4 kJ mol−1 for Sm-promoted catalyst with reaction order 1.20 and 1.10, respectively. Experimental data were also fitted to the Langmuir–Hinshelwood model. Upon subjected to both statistical and thermodynamics consistency criteria, it can be conclusively proved that single-site mechanisms with associative adsorption of glycerol best describe the glycerol pyrolysis over both unpromoted and Sm promoted catalyst in the current work, with regression coefficient values of more than 0.9.
•3wt%Sm-20wt%Ni/77wt%Al2O3 catalyst was synthesized.•H2:CO ratio that averaged 1.60 was obtained.•The activation energy the unpromoted catalyst was 35.8 kJ mol−1•The activation energy for the Sm-promoted catalyst was 23.4 kJ mol−1
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