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排序方式: 共有2493条查询结果,搜索用时 31 毫秒
931.
The effect of addition of Nigella sativa L. oil on the quality and shelf life of pork patties 下载免费PDF全文
932.
Control of Rhizopus soft rot and quality responses in plums (Prunus domestica L.) coated with gum arabic,oregano and rosemary essential oils 下载免费PDF全文
933.
934.
L. Christoffer Johansson Marta Wolf Anders Hedenstr?m 《Journal of the Royal Society Interface》2010,7(42):61-66
Qualitative comparison of bird and bat wakes has demonstrated significant differences in the structure of the far wake. Birds have been found to have a unified vortex wake of the two wings, while bats have a more complex wake with gradients in the circulation along the wingspan, and with each wing generating its own vortex structure. Here, we compare quantitative measures of the circulation in the far wake of three bird and one bat species. We find that bats have a significantly stronger normalized circulation of the start vortex than birds. We also find differences in how the circulation develops during the wingbeat as demonstrated by the ratio of the circulation of the dominant start vortex and the total circulation of the same sense. Birds show a more prominent change with changing flight speed and a relatively weaker start vortex at minimum power speed than bats. We also find that bats have a higher normalized wake loading based on the start vortex, indicating higher relative induced drag and therefore less efficient lift generation than birds. Our results thus indicate fundamental differences in the aerodynamics of bird and bat flight that will further our understanding of the evolution of vertebrate flight. 相似文献
935.
Bally M Bailey K Sugihara K Grieshaber D Vörös J Städler B 《Small (Weinheim an der Bergstrasse, Germany)》2010,6(22):2481-2497
Sensitive and selective biosensors for high-throughput screening are having an increasing impact in modern medical care. The establishment of robust protein biosensing platforms however remains challenging, especially when membrane proteins are involved. Although this type of proteins is of enormous relevance since they are considered in >60% of the pharmaceutical drug targets, their fragile nature (i.e., the requirement to preserve their natural lipid environment to avoid denaturation and loss of function) puts strong additional prerequisites onto a successful biochip. In this review, the leading approaches to create lipid membrane-based arrays towards the creation of membrane protein biosensing platforms are described. Liposomes assembled in micro- and nanoarrays and the successful set-ups containing functional membrane proteins, as well as the use of liposomes in networks, are discussed in the first part. Then, the complementary approaches to create cell-mimicking supported membrane patches on a substrate in an array format will be addressed. Finally, the progress in assembling free-standing (functional) lipid bilayers over nanopore arrays for ion channel sensing will be reported. This review illustrates the rapid pace by which advances are being made towards the creation of a heterogeneous biochip for the high-throughput screening of membrane proteins for diagnostics, drug screening, or drug discovery purposes. 相似文献
936.
Marta Feroci Isabella Chiarotto Leucio Rossi Achille Inesi 《Advanced Synthesis \u0026amp; Catalysis》2008,350(17):2740-2746
The activation of elemental sulfur (S8) has been achieved by means of electrogenerated cyanomethyl anion [easily obtained by galvanostatic reduction from acetonitrile/tetraethylammonium hexafluorophosphate (MeCN‐Et4NPF6)]. The “activated” sulfur reacted with ylidenemalononitriles to give substituted 2‐aminothiophenes in very high yields. This variation of the Gewald reaction has been carried out using only catalytic amounts of electricity and supporting electrolyte. A proposed mechanism for the interaction between S8 and cyanomethyl anion is described. 相似文献
937.
Nicola Della Ca' Elena Motti Marta Catellani 《Advanced Synthesis \u0026amp; Catalysis》2008,350(16):2513-2516
Selectively substituted phenanthridine derivatives are obtained by a facile reaction of o‐alkylated aryl iodides, o‐bromoarenesulfonylanilines and activated olefins in the presence of palladium and norbornene as catalysts. The reaction takes place under mild conditions to give the products in satisfactory yields using readily available starting materials. 相似文献
938.
Annatto seeds are known as the only natural source of bixin, a carotenoid widely used in the food industry as colourant. Thus, the aim of this study was to obtain annatto extracts with different solvents and use statistical multivariate analysis to correlate the antioxidant and colourant properties of these extracts. According to the Principal Component Analysis, PC1 was associated to colour and PC2 to antioxidant capacity. Extracts with similar polarities were joined together by Cluster Analysis. The annatto extracts obtained with methanol/water and ethanol/water were characterized by their low bixin levels and a soft yellowish colour, whilst those obtained with methanol, ethanol and ethyl acetate showed red colour and higher bixin contents. The best solvent for bixin extraction was ethyl acetate (4.9 mg bixin/g seeds), whereas the highest total phenolic levels were verified in the most polar extracts, achieving maximum of 1.84 gallic acid equivalent/g seeds in the methanol/water extract. On the other hand, the hexane extract showed both low phenolic and bixin contents, as well as low free radical scavenging activity. Taking into consideration the antioxidant and colourant properties, solvents with medium polarity, especially methanol, should be used to obtain functional annatto extracts. 相似文献
939.
Chiara Vitale-Brovarone Francesco Baino Marta Miola Renato Mortera Barbara Onida Enrica Verné 《Journal of materials science. Materials in medicine》2009,20(3):809-820
Glass–ceramic macroporous scaffolds were prepared using glass powders and polyethylene (PE) particles of two different sizes.
The starting glass, named as Fa-GC, belongs to the system SiO2–P2O5–CaO–MgO–Na2O–K2O–CaF2 and was synthesized by a traditional melting-quenching route. The glass was ground and sieved to obtain powders of specific
size which were mixed with PE particles and then uniaxially pressed in order to obtain crack-free green samples. The compact
of powders underwent a thermal treatment to remove the organic phase and to sinter the Fa-GC powders. Fa-GC scaffolds were
characterized by means of X-Ray Diffraction, morphological observations, density measurements, image analysis, mechanical
tests and in vitro tests. Composite systems were then prepared combining the drug uptake-delivery properties of MCM-41 silica
micro/nanospheres with the Fa-GC scaffold. The system was prepared by soaking the scaffold into the MCM-41 synthesis batch.
The composite scaffolds were characterized by means of X-Ray Diffraction, morphological observations, mechanical tests and
in vitro tests. Ibuprofen was used as model drug for the uptake and delivery analysis of the composite system. In comparison
with the MCM-41-free scaffold, both the adsorption capacity and the drug delivery behaviour were deeply affected by the presence
of MCM-41 spheres inside the scaffold. 相似文献
940.
Anna Lizo Joanna Tisoczyk Marta Gajewska Ryszard Drod 《International journal of molecular sciences》2021,22(18)
Some misfolded proteins, e.g., immunoglobulin monoclonal free light chains (FLC), tend to form fibrils. Protein deposits in tissue may lead to amyloidosis and dysfunction of different organs. There is currently no technique allowing for the identification of FLC that are prone to aggregate. The development of such a method would enable the early selection of patients at high risk of developing amyloidosis. The aim of this study was to investigate whether silver nanoparticles (AgNPs) could be a useful tool to study the process of aggregation of FLC and their susceptibility to form the protein deposits. Mixtures of AgNPs and urine samples from patients with multiple myeloma were prepared. To evaluate the aggregation process of nanoparticles coated with proteins, UV-visible spectroscopy, transmission electron microscopy, and the original laser light scattering method were used. It has been shown that some clones of FLC spontaneously triggered aggregation of the nanoparticles, while in the presence of others, the nanoparticle solution became hyperstable. This is probably due to the structure of the chains themselves, unique protein-AgNPs interactions and perhaps correlates with the tendency of some FLC clones to form deposits. Nanoparticle technology has proven to be helpful in identifying clones of immunoglobulin FLC that tend to aggregate. 相似文献