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排序方式: 共有737条查询结果,搜索用时 15 毫秒
721.
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Tomek Kopczyński Marek Loźynski Krystyna Prochaska Artur Burdzy Ryszard Cierpiszewski Jan Szymanowski 《溶剂提取与离子交换》2013,31(4):701-725
ABSTRACT Composition, structure and interfacial activity of alkanal oximes and kinetics of copper extraction from chloride solutions are discussed. Semiempirical self-consistent field calculations are used to study the structure of alkanal oximes and their mono- and dihydrates. These calculations are in a qualitative agreement with the ratio of alkanal (Z)-and (E)-isomers, interfacial activity and kinetics data. 相似文献
723.
Luana Zilz Martinho Rau Nelson Budag Mauro Scharf Artur Cavaco‐Paulo Jürgen Andreaus 《Coloration Technology》2013,129(1):49-54
Cellulases are widely applied in textile finishing, such as for the removal of protruding surface fibrils to reduce pilling propensity and to achieve the worn‐out look in denim garments. The main drawback of enzymatic denim processing is the back‐staining of indigo, which reduces the desired blue–white contrast. Alongside an accurate selection of the type of cellulase or vigorous post‐washing of the garments, the simultaneous application of auxiliaries in the enzymatic treatment may help to reduce back‐staining and improve cellulase efficiency. In the present work, the influence of additives such as surfactants and dispersing agents on indigo adsorption and on the treatment of an undyed cotton fabric with Hypocrea jecorina cellulases was investigated. Indigo adsorption was successfully reduced by more than 75% with ethoxylated nonionic surfactants at concentrations below 0.2 g l?1. The weight loss of cotton fabrics after 120 min treatment was significantly increased with nonionic surfactants and polyvinylpyrrolidone. It could be further shown that protein adsorption on the cotton fabric decreased with the increasing concentration of the additives, while the nonionic surfactants were more efficient than the polyvinylpyrrolidone. Adsorption of a complete cellulase mixture was affected differently by the surfactants than by an exoglucanase‐free endoglucanase‐rich preparation. 相似文献
724.
Helena Ferreira Teresa Matamá Raquel Silva Carla Silva Andreia C. Gomes Artur Cavaco-Paulo 《Reactive and Functional Polymers》2013,73(10):1328-1334
From ancientness, suitable materials have been developed to cover the wounds in order to prevent infections and promote proper wound healing. In this study, the successful development of functionalized nonwoven gauzes with liposomes entrapping anti-inflammatory piroxicam is reported. Piroxicam is a non-steroidal anti-inflammatory drug (NSAID) that can suppress a persistent inflammatory response, leading to improved wound healing. The results demonstrated that the highest NSAID concentration released is achieved when gauzes were previously cationized with poly(diallyldimethylammonium chloride) (PDDA) and high concentration of phospholipid (≈3000 μM) and multilamellar liposomes (MLVs) were used. MLVs were also the best vehicle considering their biocompatibility with skin human fibroblasts, where no toxicity was observed for neither of the tested conditions.The developed functionalized gauzes can be, therefore, a good strategy to treat chronic wounds. 相似文献
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726.
Wojciech Dro?d? Micha? Ko?odziejski Grzegorz Markiewicz Anna Jenczak Artur R. Stefankiewicz 《International journal of molecular sciences》2015,16(7):16300-16312
We describe here the generation of new donor-acceptor disulfide architectures obtained in aqueous solution at physiological pH. The application of a dynamic combinatorial chemistry approach allowed us to generate a large number of new disulfide macrocyclic architectures together with a new type of [2]catenanes consisting of four distinct components. Up to fifteen types of structurally-distinct dynamic architectures have been generated through one-pot disulfide exchange reactions between four thiol-functionalized aqueous components. The distribution of disulfide products formed was found to be strongly dependent on the structural features of the thiol components employed. This work not only constitutes a success in the synthesis of topologically- and morphologically-complex targets, but it may also open new horizons for the use of this methodology in the construction of molecular machines. 相似文献
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Nicolas Gaillard Yuancheng Chang Alexander DeAngelis Scott Higgins Artur Braun 《International Journal of Hydrogen Energy》2013
We report on the photoelectrochemical performances of a nanocomposite photoactive material made of copper tungstate (CuWO4) and multi-wall carbon nanotubes (MWCNT). The purpose of this work was to create a light absorber/charge collector composite material with tunable electronic transport properties to minimize the bulk resistance of CuWO4 material class. Nanocomposite thin films (typically 2.0 ± 0.1 μm) were fabricated by means of spray pyrolysis using solutions containing copper acetate, ammonium metatungstate and MWCNT. Spray-deposited polycrystalline CuWO4 films were found to be porous, though crack-free, and made of CuWO4 nanoparticles with dimensions in the 10–50 nm range. Tauc plots derived from UV–visible and photocurrent spectroscopy techniques led to a consistent band gap value of 2.20 (±0.05) eV. Electrochemical impedance spectroscopy performed in pH10 buffer solution under Air Mass 1.5 global (AM1.5G) at 0.8 V vs. saturated calomel electrode (1.63V vs. reversible hydrogen electrode) pointed out a bulk resistance reduction by 30% on nanocomposites photoanodes when compared to un-modified CuWO4 control samples. It is worth mentioning that the reduction in bulk resistance was achieved with an extremely low MWCNT:CuWO4 weight ratio (1:10,000), in which MWCNT absorbed less than 2% of incoming light. Subsequent linear scan voltammetry (LSV) performed in the same conditions revealed a photocurrent density increase of 26% at 0.8 VSCE (1.63 VRHE) compared to control samples. Additional LSV and incident photon-to-current efficiency measurements demonstrated that MWCNT served as effective electron collectors distributed throughout the entire CuWO4 bulk. 相似文献
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730.