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排序方式: 共有739条查询结果,搜索用时 15 毫秒
731.
Olivier Jeannin 《Inorganica chimica acta》2007,360(13):3820-3824
Two closely related 1:1 salts are obtained upon electrocrystallization of BEDT-TTF (BEDT-TTF: bis(ethylenedithio)tetrathiafulvalene) in the presence of the isosteric [M(tfadt)2]− dithiolene complexes (tfadt: 1-trifluoromethyl-2-cyano-1,2-dithiolato), which essentially differ by their spin state, S = 0 in [Au(tfadt)2]−, S = 1/2 in [Ni(tfadt)2]−. In both [BEDT-TTF][M(tfadt)2] salts, the BEDT-TTF radical cations form chains with a strong lateral overlap and strong antiferromagnetic interactions while the paramagnetic anions in the nickel-containing salt [BEDT-TTF][Ni(tfadt)2] are essentially non-interacting. The structural differences between the nickel and gold complexes are analyzed and discussed. 相似文献
732.
Photosensitized efficacy of tetrasulfonated phthalocyanines of zinc, aluminum and nickel (ZnPcS4, AlPcS4 and NiPcS4, respectively) as studied by gramicidin channel (gA) photoinactivation was compared with adsorption of the dyes on the surface of a bilayer lipid membrane as measured by the inner field compensation method. The adsorption of the negatively charged phthalocyanines on diphytanoylphosphatidylcholine (DPhPC) membranes led to formation of a negative boundary potential difference between the membrane/water interfaces. Good correlation was shown between the photodynamic activity and the membrane binding of the three metallophthalocyanines. ZnPcS4 appeared to be the most potent of these photosensitizers, while NiPcS4 was completely ineffective. All of these phthalocyanines displayed no binding and negligible gA photoinactivation with membranes formed of glycerol monooleate (GMO), whereas Rose Bengal exhibited significant binding and photodynamic efficacy with GMO membranes. Gramicidin photoinactivation in the presence of AlPcS4, being insensitive to the ionic strength of the bathing solution, was inhibited by fluoride and attenuated by phosphate ions. A blue shift of the fluorescence peak position of ZnPcS4 dissolved in ethanol was elicited by phosphate, similarly to fluoride, which was indicative of the coordination interaction of these ions with the central metal atom of the phthalocyanine macrocycle. This interaction was enhanced in the medium modeling the water-membrane interface. The results obtained imply that binding of tetrasulfonated metallophthalocyanines to phospholipid membranes is determined primarily by metal-phosphate coordination. 相似文献
733.
Christian Schulze Danny Vogel Manuela Sander Rainer Bader 《Computer methods in biomechanics and biomedical engineering》2019,22(1):25-37
Polyurethane (PU) foam is a material often used in biomechanical experiments and demands for the definition of crushable foam plasticity (CFP) in numerical simulations of the primary stability and deformation of implants, to describe the crushing behaviour appropriately. Material data of PU foams with five different densities (10–40 pounds per cubic foot were ascertained experimentally in uniaxial compression test and used to calibrate CFP models for finite element modelling. Additionally, experimental and numerical deformation, push-out and lever-out tests of press-fit acetabular cups were carried out to assess the influence of the chosen material definition (linear elastic and CFP) on the numerical results. Comparison of the experimentally and numerically determined force–displacement curves of the uniaxial compression test showed a mean deviation of less than 3%. In primary stability testing, the deviation between the experimental and numerical results was in a range of 0%–27% for CFP modelling and 64%–341% for the linear elastic model. The material definition selected, highly influenced the numerical results in the current study. The use of a CFP model is recommended for further numerical simulations, when a deformation of the foam beyond the yield strength is likely to occur. 相似文献
734.
735.
Graciele de Oliveira Kuhn Marceli Fernandes Silva Jéssica Mulinari Simone Golunski Rogério Marcos Dallago Clarissa Dalla Rosa 《Biocatalysis and Biotransformation》2016,34(6):291-294
Inulinase from Aspergillus niger was immobilized in polyurethane foam (PU). Immobilized catalyst was treated in pressurized liquefied petroleum gas (LPG) system. This biocatalyst was used in the fructooligosaccharide production using sucrose as substrate in aqueous system. The main objective of this study was to evaluate the reaction yield and productivity by using polyurethane foam as a low-cost support for enzyme immobilization in an alternative processes for fructooligosaccharide production in pressurized LPG system with potential for industrial application. The total FOS concentration obtained were 31% as a result of sucrose concentration reduction, and formation of FOS long chain (GF3 and GF4) from kestose (GF2). FOS concentrations of 5%, 22%, and 3% were obtained for GF2, GF3, and GF4, respectively. The methodology suggested in this research work, enzyme immobilization in a low-cost support, and treatment in LPG, showed potential technology for fructooligosaccharide synthesis. 相似文献
736.
The 1:1 condensation of 1,2-diaminopropane and 1-phenylbutane-1,3-dione at high dilution gives a mixture of two positional isomers of terdentate mono-condensed Schiff bases 6-amino-3-methyl-1-phenyl-4-aza-2-hepten-1-one (HAMPAH) and 6-amino-3,5-dimethyl-1-phenyl-4-aza-2-hexen-1-one (HADPAH). The mixture of the terdentate ligands has been used for further condensation with pyridine-2-carboxaldehyde or 2-acetylpyridine to obtain the unsymmetrical tetradentate Schiff base ligands. The tetradentate Schiff bases are then allowed to react with the methanol solution of copper(II) and nickel(II) perchlorate separately. The X-ray diffraction confirms the structures of two of the complexes and shows that the condensation site of the diamine with 1-phenylbutane-1,3-dione is the same. 相似文献
737.
738.
Fazilet Vardar-Sukan 《Biotechnology advances》1998,16(5-6):913-948
This review examines the significance of foaming in bioprocesses, the mechanics of foam formation and destruction, and the methods of foam control and suppression. Emphasis is given to chemical antifoaming agents and characterization of their efficiencies. Criteria for selecting antifoaming agents are discussed. 相似文献
739.
A droplet fractionation method was previously developed to concentrate a dilute nonfoaming protein solution. In that earlier
study with invertase, it was demonstrated that droplets created by ultrasonic energy waves could be enriched up to 8 times
that of the initial dilute invertase solution. In this study, a mixture of bromelain (a foaming protein) and invertase (a
nonfoaming protein) is investigated as a preliminary step to determine if droplet fractionation can also be used to separate
a non-foaming protein from foaming proteins. The foaming mixture containing bromelain is first removed by bubbling the binary
mixture with air. After the foam is removed, the protein rich air-water interfacial layer is skimmed off (prior to droplet
fractionation) so as not to interfere with the subsequent droplet production from the remaining bulk liquid, rich in non-foaming
protein. Finally, sonic energy waves are then applied to this residual bulk liquid to recover droplets containing the non-foaming
protein, presumed to be invertase. The primary control variable used in this droplet fractionation process is the pH, which
ranged for separate experiments between 2 and 9. It was observed that the maximum overall protein partition coefficients of
5 and 4 were achieved at pH 2 and 4, respectively, for the initial foaming experiment followed by the post foaming droplet
fractionation experiment. 相似文献