排序方式: 共有57条查询结果,搜索用时 15 毫秒
21.
The novel agarose–nickel (Ag–Ni) expanded bed matrix was investigated with regard to suitability for practical recovery of nano-bioproducts (NBPs) such as protein nanoparticles as drug delivery carriers. The matrix was immobilized by Reactive Green 19 (RG19) dye–ligand and was subjected to biochemical evaluation through batch adsorption studies (isotherm and kinetic studies) and column chromatography of bovine serum albumin nanoparticles (BSA NPs) with average size of 85–95 nm as a model system. Based on adsorption isotherm investigations, the adsorption phenomenon appeared to follow the Langmuir isotherm model with maximum binding capacity of 24.9 mg/ml adsorbent. Subsequently adsorption data were modeled using the pseudo-first-order and pseudo-second-order kinetics equation. The results demonstrated that the adsorption process kinetics followed the pseudo-first-order kinetic model. The dynamic binding capacity (DBC) for BSA NP adsorption was calculated at various flow velocities which showed favorable column efficiency at relatively high flow rates. BSA NPs recovery was studied in the expanded bed column which resulted in 74 % recovery. The results indicated that the novel resin is a promising chromatographic medium for protein nanoparticle separation with high adsorption capacity and column efficiency at reasonably high flow rates. The generic application of such dye–ligand immobilized composite matrix for the adsorption and purification of BSA NPs as a nanoparticulate bioproduct was discussed. 相似文献
22.
Hamid Reza Shaterian Fahimeh Khorami Razieh Doostmohammadi Azita Amirzadeh Majid Ghashang 《Phosphorus, sulfur, and silicon and the related elements》2013,188(9):2227-2237
Silica-supported zinc chloride (SiO2-ZnCl2) and novel alumina-supported sodium hydrogensulfate (NaHSO4-Al2O3) as recyclable heterogeneous catalysts have been used for the mild trimethylsilylation of hydroxyl groups under ambient conditions. This procedure also allows for the selective protection of primary and secondary alcohols in the presence of tertiary alcohols. 相似文献
23.
In this study, non-Darcy inertial two-phase incompressible and non-stationary flow in heterogeneous porous media is analyzed
using numerical simulations. For the purpose, a 3D numerical tool was fully developed using a finite volume formulation, although
for clarity, results are presented in 1D and 2D configurations only. Since a formalized theoretical model confirmed by experimental
data is still lacking, our study is based on the widely used generalized Darcy–Forchheimer model. First, a validation is performed
by comparing numerical results of the saturation front kinetics with a semi-analytical solution inspired from the Buckley–Leverett
model extended to take into account inertia. Second, we highlight the importance of inertial terms on the evolution of saturation
fronts as a function of a suitable Reynolds number. Saturation fields are shown to have a structure markedly different from
the classical case without inertia, especially for heterogeneous media, thereby, emphasizing the necessity of a more complete
model than the classical generalized Darcy’s one when inertial effects are not negligible. 相似文献
24.
25.
Constituents of the essential oil of Scabiosa flavida from Iran 总被引:1,自引:0,他引:1
The composition of the essential oil of the aerial parts of Scabiosa flavida was investigated by GC and GC-MS. Forty-three components representing 94.2% of the essential oil were characterized. The
main components of the oil were tricosane (15.5%), rosifoliol (15.3%), (E)-caryophyllene (10.7%), and α-humulene (7.9%).
Published in Khimiya Prirodnykh Soedinenii, No. 5, pp. 426–427, September–October, 2006. 相似文献
26.
27.
Azita Mayeli 《Journal of Mathematical Analysis and Applications》2008,348(2):671-684
We present a notion of frame multiresolution analysis on the Heisenberg group, abbreviated by FMRA, and study its properties. Using the irreducible representations of this group, we shall define a sinc-type function which is our starting point for obtaining the scaling function. Further, we shall give a concrete example of a wavelet FMRA on the Heisenberg group which is analogous to the Shannon MRA on R. 相似文献
28.
Elbouyahyaoui Lakhdar Heyouni Mohammed Tajaddini Azita Saberi-Movahed Farid 《Numerical Algorithms》2021,87(3):1257-1299
Numerical Algorithms - The problem of shifted linear systems is an important and challenging issue in a number of research applications. Krylov subspace methods are effective techniques for... 相似文献
29.
A new, facile, and cost-effective process involving the solvent-free synthesis of amidoalkyl naphthols using a three-component, one-pot condensation reaction of β-naphthol, aromatic aldehyde, and amides in the presence of Al(H2PO4)3 as heterogeneous catalyst under thermal conditions and microwave irradiation has been described. This new approach has the advantage of consistently excellent yields and short reaction times. The catalyst has shown a very stable catalytic activity in the reaction conditions and also can be recovered and recycled. 相似文献
30.
Shabnam Fakhari Azita Nouri Mina Jamzad Samira Arab‐Salmanabadi Foujan Falaki 《中国化学会会志》2021,68(1):67-75
In this study, the density functional theory computational method is used to investigate the encapsulation process of metformin into three types of the cyclic peptides composed of eight serine (CP1), eight glycine (CP2), and four serine‐glycine (CP3) cyclic peptides as a new model in the process of drug delivery in the gas phase. The obtained results using the B3LYP/6‐31++G (d,p) method indicate that the complexes formed are energetically favored. Furthermore, results reveal that the drug encapsulation process is typically chemisorption. The natural bonding orbital analysis shows that the intermolecular interaction of the C2 complex (metformin/CP2) is stronger than the C1 (Metformin/CP1) and C3 (Metformin/CP3) complexes due to greater total charge transfer energy, and the C1 complex is found to be the most favored complex. The theory of atoms in molecule (AIM) method is used to analyze the nature of interactions in different molecular systems. The results show the investigated cyclic peptides as effective carriers of metformin in the nanomedicine field. 相似文献