199 research outputs found
Solid Oxide Fuel Cells with both High Voltage and Power Output by Utilizing Beneficial Interfacial Reaction
An intriguing cell concept by applying proton-conducting oxide as the ionic conducting phase in the anode and taking advantage of beneficial interfacial reaction between anode and electrolyte is proposed to successfully achieve both high open circuit voltage (OCV) and power output for SOFCs with thin-film samarium doped ceria (SDC) electrolyte at temperatures higher than 600 °C. The fuel cells were fabricated by conventional route without introducing an additional processing step. A very thin and dense interfacial layer (2–3 μm) with compositional gradient was created by in situ reaction between anode and electrolyte although the anode substrate had high surface roughness (\u3e5 μm), which is, however, beneficial for increasing triple phase boundaries where electrode reactions happen. A fuel cell with Ni–BaZr0.4Ce0.4Y0.2O3 anode, thin-film SDC electrolyte and Ba0.5Sr0.5Co0.8Fe0.2O3–δ (BSCF) cathode has an OCV as high as 1.022 V and delivered a power density of 462 mW cm−2 at 0.7 V at 600 °C. It greatly promises an intriguing fuel cell concept for efficient power generation
Synthesis of silicalite-poly(furfuryl alcohol) composite membranes for oxygen enrichment from air
Silicalite-poly(furfuryl alcohol) [PFA] composite membranes were prepared by solution casting of silicalite-furfuryl alcohol [FA] suspension on a porous polysulfone substrate and subsequent in situ polymerization of FA. X-ray diffraction, nitrogen sorption, thermogravimetric analysis, scanning electron microscopy, and energy-dispersive X-ray spectroscopy were used to characterize silicalite nanocrystals and silicalite-PFA composite membranes. The silicalite-PFA composite membrane with 20 wt.% silicalite loading exhibits good oxygen/nitrogen selectivity (4.15) and high oxygen permeability (1,132.6 Barrers) at 50°C. Silicalite-PFA composite membranes are promising for the production of oxygen-enriched air for various applications
Achieving both high selectivity and current density for CO2 reduction to formate on nanoporous tin foam electrocatalysts
Currently, low catalytic activity, selectivity and stability are the biggest challenges which restrict the large scale applications of CO2 electrochemical reduction. Formic acid, one of the highest value-added products from electrochemical reduction of CO2, has gathered much interest. Here, we develop nanoporous tin foam catalysts which exhibit significantly high selectivity and faster production rate to formate. In a 0.1 M NaHCO3 solution, the maximum Faradaic efficiency for formate production reaches above 90% with a current density over 23 mA cm-2 , which are among the highest reported value to date under ambient conditions. The improved production rate can be attributed to the high surface area and porous structure. Moreover, the electrocatalysts are quite stable, namely, the Faradaic efficiency remains unchanged during 16 hour electrolysis. This is a promising technology to convert CO2 into useful hydrocarbons
Der Einfluss unzureichender prothetischer Versorgung auf den Ernährungszustand und die Lebensqualität geriatrischer Patienten
Ziel der Untersuchung: Mit dieser Studie sollen Zusammenhänge zwischen der Versorgung älterer Patienten mit Zahnersatz und ihrem Ernährungszustand sowie der Lebensqualität analysiert werden.
Hintergrund: Es gibt zahlreiche Hinweise darauf, dass der Gebisszustand einen entscheidenden Einfluss auf den Ernährungszustand älterer Patienten hat und verantwortlich für eine Mangelernährung sein kann. Des Weiteren deuten aktuelle Untersuchungen daraufhin, dass ebenfalls Zusammenhänge zwischen Gebisszustand und mundgesundheitsbezogener Lebensqualität (MLQ) bestehen.
Material und Methode: In das Untersuchungsvorhaben wurden insgesamt 100 Probanden einbezogen, welche mindestens 60 Jahre alt und mit festsitzendem oder herausnehmbaren Zahnersatz versorgt waren. Die Probanden wurden nach der zahnärztlichen Untersuchung in zwei Gruppen aufgeteilt. Bei den Probanden der einen Gruppe lag eine akzeptable bis gute prothetische Versorgung vor, eine zahnärztliche Intervention war nicht erforderlich. Bei den Probanden der andren Gruppe war eine Reparatur oder Erneuerung des Zahnersatzes notwendig. Der Ernährungszustand wurde mittels Mini Nutritional Assessment (MNA) und der Untersuchung einiger wichtiger Ernährungsmarker im Blut analysiert. Die MLQ wurde mittels der Fragebögen OHIP-G, OHIP-G14 und "Anamnestischer Index nach Dworkin" bewertet. Zusätzlich wurde ein einfacher Kaufunktionstest durchgeführt, bei dem die Patienten Karottenwürfel definierter Größe möglichst fein zerkauen sollten.
Ergebnisse: Zeigten sich beim MNA hochsignifikante Unterschiede zwischen den Gruppen, so konnten bei der Analyse der Blutparameter keine signifikanten Unterschiede festgestellt werden. Beim OHIP-G zeigte sich ein signifikanter, bei den Kautestergebnissen ein hochsignifikanter Unterschied zwischen den beiden Gruppen.
Konklusion: Eine eindeutige, negative Auswirkung eines insuffizienten Zahnersatzes auf MLQ und Ernährungszustand konnte nicht nachgewiesen werden. Der Komplex Lebensqualität und Ernährung wird durch multiple Faktoren beeinflusst, die Kauleistung repräsentiert nur einen Teilaspekt
Directly growing hierarchical nickel-copper hydroxide nanowires on carbon fibre cloth for efficient electrooxidation of ammonia
Ammonia is an attractive carbon-free chemical for electrochemical energy conversion and storage. However, the sluggish kinetic rates of the ammonia electrooxidation reaction, and high cost and poisoning of Pt-based catalysts still remain challenges. This also limits the development of direct ammonia fuel cells. In this work, we directly grew hierarchical mixed NiCu layered hydroxides (LHs) nanowires on carbon fibre cloth electrodes by a facile one-step hydrothermal synthesis method for efficient electro-oxidation of ammonia. This catalyst achieves a current density of 35 mA cm−2 at 0.55 V vs. Ag/AgCl, which is much higher than that of bare Ni(OH)2 catalyst (5 mA cm−2). This is due to abundant active sites and a synergistic effect between Ni and Cu, possibly due to the formation of Ni1−xCuxOOH on the surface of the catalysts through the electrochemical activation of the mixture of Cu(OH)2 and α-Ni(OH)2. In the investigated first row transition elements, it is found that Cu is the sole first-row transition metal to effectively improve activity of Ni(OH)2 for ammonia electrooxidation. This mixed NiCu LHs nano-wire catalyst outperforms commercial Pt/C catalyst in the aspects of ammonia oxidation current and stability, demonstrating it to be a promising low-cost and stable catalyst for efficient ammonia electrooxidation in alkaline condition, which is a potential electrode for ammonia fuel cells for power generation or electrolysis of ammonia for ammonia-containing wastewater treatment
Pironetin reacts covalently with cysteine-316 of α-tubulin to destabilize microtubule
This work was funded by grants to C.L. from the National Natural Science Foundation of
China (81373283 and U1402222). J.H.N. is supported as an award holder of Chinese National
Thousand Talents Program, Wellcome Trust Senior Investigator Award (WT100209MA) and
Royal Society Wolfson Merit Award. X.Z. is supported by Sichuan Province Thousand Talents
Scheme in China and the State Key Program of National Natural Science of China (21534008).Molecules which alter the normal dynamics of microtubule assembly and disassembly
include many anticancer drugs in clinical use. So far all such therapeutics target β-tubulin
and structural biology has explained the basis of their action and permitted design of new
drugs. However by shifting the profile of β-tubulin isoforms, cancer cells become resistant to
treatment. Compounds that bind to α-tubulin are less well characterized and unexploited.
The natural product pironetin is known to bind to α-tubulin and is a potent inhibitor of
microtubule polymerization. Previous reports had identified that pironetin reacts with lysine-352
residue however analogues designed on this model had much lower potency which was
difficult to explain, hindering further development. We report crystallographic and mass
spectrometric data that reveal that pironetin forms a covalent bond to cysteine-316 in α-tubulin
via a Michael addition reaction. These data provide a basis for the rational design of α-tubulin targeting chemotherapeutics.Publisher PDFPeer reviewe
Seeded growth of ZIF-8 on the surface of carbon nanotubes towards self-supporting gas separation membranes
Graphene/titanium carbide composites prepared by sol-gel infiltration and spark plasma sintering
Graphene/titanium carbide composites were synthesized by means of sol-gel infiltration and spark plasma sintering (SPS). The graphene used in this research was casted into a sponge-like shape, composed of a three-dimensional (3D) network of graphene sheets. The sol-gel infiltration synthesis method allowed the formation of nanostructured ceramics inside the porous structure of graphene networks, thus forming composites. The compositions and microstructures of the Ti-O-C composites changed with the amount of the polymerizable carbon source (i.e. furfuryl alcohol (FA)) in the solution. A high carbon ratio was required to maintain the structure of the graphene network, as the graphene sheets could become a carbon source to react with TiO2 resulting in a lamellar-shaped grain morphology. Samples after SPS showed some toughening effects, such as de-bonding, bridging and formation of microcracks. Vickers hardness, electrical resistivity and thermal conductivity were examined for the composites. (C) 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved
Tailoring molecular interactions between microporous polymers in high performance mixed matrix membranes for gas separations
Boosting oxygen evolution reaction by activation of lattice‐oxygen sites in layered Ruddlesden‐Popper oxide
Emerging anionic redox chemistry presents new opportunities for enhancing oxygen evolution reaction (OER) activity considering that lattice-oxygen oxidation mechanism (LOM) could bypass thermodynamic limitation of conventional metal-ion participation mechanism. Thus, finding an effective method to activate lattice-oxygen in metal oxides is highly attractive for designing efficient OER electrocatalysts. Here, we discover that the lattice-oxygen sites in Ruddlesden-Popper (RP) crystal structure can be activated, leading to a new class of extremely active OER catalyst. As a proof-of-concept, the RP Sr3(Co0.8Fe0.1Nb0.1)2O7-δ (RP-SCFN) oxide exhibits outstanding OER activity (eg, 334 mV at 10 mA cm−2 in 0.1 M KOH), which is significantly higher than that of the simple SrCo0.8Fe0.1Nb0.1O3-δ perovskite and benchmark RuO2. Combined density functional theory and X-ray absorption spectroscopy studies demonstrate that RP-SCFN follows the LOM under OER condition, and the activated lattice oxygen sites triggered by high covalency of metal-oxygen bonds are the origin of the high catalytic activity.This work was financially supported by the Australian Research Council (Discovery Early Career Researcher Award No. DE190100005)
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