Characterization of a Novel Agarose–Nickel Composite Matrix for Protein Nanoparticles Affinity Chromatography in Expanded Bed

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.     

Numerical Simulation of Two-Phase Inertial Flow in Heterogeneous Porous Media

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.     

Constituents of the essential oil of Scabiosa flavida from Iran

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.     

Shannon multiresolution analysis on the Heisenberg group

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.     

On restarted and deflated block FOM and GMRES methods for sequences of shifted linear systems

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...     

Environmentally Friendly Preparation of Amidoalkyl Naphthols

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.     

Alumina Perchloric Acid (Al 2 O 3 -HClO 4 ) as an Efficient Heterogeneous Catalyst for Modified Preparation of Trimethylsilyl Ethers

A highly efficient and mild procedure for the trimethylsilylation of a wide variety of alcohols, including primary, benzylic, secondary, hindered secondary, tertiary, phenols, and oximes with hexamethyldisilazane (HMDS) using alumina perchloric acid (Al ₂ O ₃ -HClO ₄ ) as recyclable heterogeneous catalyst in excellent yields with short reaction times (3?65 min) under ambient conditions is described.     

Synthesis of novel 2‐(2‐methylsulfonyl‐1‐methyl‐1H‐imidazol‐5‐yl)‐5‐(alkylsulfonyl)‐1,3,4‐thiadiazoles

Starting from 5‐hydroxymethyl‐2‐mercapto‐1‐methyl‐1H‐imidazole (1), a series of 2‐(1‐methyl‐2‐methylsulfonyl‐1H‐imidazol‐5‐yl)‐5‐alkylthio and 5‐alkylsulfonyl‐1,3,4‐thiadiazole derivatives ( 9a , 9b , 9c , 9d and 10a , 10b , 10c , 10d ) were prepared as potential antimicrobial agents. The structure of the obtained compounds was confirmed by NMR, IR, Mass spectroscopy, and elemental analysis. J. Heterocyclic Chem., (2010)     

Investigation of inclusion complex of metformin into selective cyclic peptides as novel drug delivery system: Structure,electronic properties,AIM, and NBO study via DFT

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.