Three-dimensional microwell arrays for cell culture

We propose the concept of three-dimensional (3D) microwell arrays for cell culture applications and highlight the importance of oxygen diffusion through pores in all three dimensions to enhance cell viability.     

Chiral ligand-exchange chromatography of amino acids using porous graphitic carbon coated with a dinaphthyl derivative of neamine

In this paper, we describe the preparation and the evaluation of a porous graphitic carbon (PGC) column coated with a new dinaphthyl derivative of neamine for chiral ligand-exchange (LE) chromatography. It was shown that the graphitic surface/dinaphthyl anchor system efficiently (1.15 μmol/m²) and stably (three months of intensive use) adsorbs the neamine template onto the chromatographic support. The resulting coated PGC stationary phase showed appreciable LE-based enantioselective properties towards several native amino acids. Chromatographic separation of methionine enantiomers using a dinaphtyl neamine-based ligand-exchange chiral stationary phase     

Unification of Bessel Functions of Different Orders

We investigate the internal space of Bessel functions which is associated to thegroup Z of positive and negative integers defining their orders. As a result wepropose and prove a new unifying formula (to be added to the huge literatureon Bessel functions) generating Bessel functions of real orders out of integerorder ones. The unifying formula is expected to be of great use in appliedmathematics. Some applications of the formula are given for illustration     

A fully discrete H 1-Galerkin method with quadrature for nonlinear advection–diffusion–reaction equations

We propose and analyze a fully discrete H ¹-Galerkin method with quadrature for nonlinear parabolic advection–diffusion–reaction equations that requires only linear algebraic solvers. Our scheme applied to the special case heat equation is a fully discrete quadrature version of the least-squares method. We prove second order convergence in time and optimal H ¹ convergence in space for the computer implementable method. The results of numerical computations demonstrate optimal order convergence of scheme in H ^k for k = 0, 1, 2. Support of the Australian Research Council is gratefully acknowledged.     

Hypothetical <Emphasis Type="Italic">Hypercloso</Emphasis> Octahedral M<Subscript>4</Subscript>N<Subscript>2</Subscript> Clusters: A New Mode of Dinitrogen Coordination?

Density functional theory (DFT) calculations carried out on a series of [M₄(CO)₁₂N₂]²⁺ and M₄(CO)₁₂N₂ (M=Fe, Ru, Os) predict that the M₄N₂ square bipyramidal (octahedral) architecture should be stable for the particular electron count of 6 skeletal electron pairs (or 60 metal valence electrons). This octahedral architecture is electron-deficient with respect to the Wade-Mingos rules and exhibits a through-cage N–N bond of order one. Thus, these hypothetical clusters present a new coordination mode of dinitrogen.     

Substituent effect on structure,electron density,and intramolecular hydrogen bonding in nitroso‐oxime methane

Density functional calculations with Beck's three‐parameter hybrid method using the correlation functional of Lee, Yang, and Parr (B3LYP) were carried out for investigation of the intramolecular hydrogen bond strength in Nitroso‐oxime methane and its derivatives. Also, vibrational frequencies for them were calculated at the same level of theory. The π‐electron delocalization parameter (Q) and as a geometrical indicator of a local aromaticity, the geometry‐based harmonic oscillator measure of aromaticity index has been applied. Additionally, the linear correlation coefficients between substituent constants and selected parameters in R position have calculated. The obtained results show that the hydrogen bond strength is mainly governed by the resonance variations inside the chelate ring induced by the substituent groups. The topological properties of the electron density distributions for O? H ··· O intramolecular bridges have been analyzed in terms of the Bader theory of atoms in molecules (AIM). Correlations between the H‐bond strength and topological parameters have been also studied. The electron density (ρ) and Laplacian (?²ρ) properties, estimated by AIM calculations, show that O ··· H bond have low ρ and negative (?²ρ) values (consistent with covalent character of the HBs), whereas O? H bond have positive (?²ρ) Furthermore, the analysis of hydrogen bond in this molecule and its derivatives by quantum theory of natural bond orbital (NBO) methods fairly support the ab initio results. Natural population analysis data, the electron density, and Laplacian properties as well as υ(O? H) and γ(O? H) were further used for estimation of the hydrogen bonding interactions and the forces driving their formation. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011     

Thermodynamical and structural insights of orange II adsorption by MgRAlNO3 layered double hydroxides

[Mg_1−x Al_x(OH)₂][(NO₃)_x, nH₂O] Layered Double Hydroxide (LDH) sorbents with variable Mg/Al molar (R=(1−x)/x) ratios were investigated for adsorption of azo dye, orange II (OII) at various pH and temperature conditions. Mg₂AlNO₃ displays the highest adsorption capacity with 3.611 mmol of OII per gram of Mg₂AlNO₃ at 40 °C. Adsorption isotherms have been fitted using the Langmuir model and free energy of adsorption (ΔG°), enthalpy (ΔH°) and entropy (ΔS°) were calculated. The experimental values for ΔG° in temperature range between 10 and 40 °C were found to be negative indicating that a spontaneous process occurred. Positive calculated enthalpy values, characteristic of an endothermic process were found. Characterization of solids (PXRD, FTIR, UV-vis, TGA/DTA, adsorption isotherm BET analysis, SEM and Zetametry) before and after adsorption showed that adsorption proceeds in two steps. First, adsorption occurs at the LDH surface, followed by intercalation via anion exchange.     

Degree centrality of combustion reaction networks for analysing and modelling combustion processes

Combustion research still needs more advanced fundamental understanding of combustion chemistry and dynamics from molecule scale to particle. The latter is also needed for soot and nanoparticles formation and combustion system control such as homogeneous charge compression ignition engine, and flame regimes and instability. The complex interactions between hundreds of species linked within thousands of reactions continue to be a challenge to analyse and model. The focus on this paper is to develop a method to facilitate the modelling and analysing of the detailed kinetics chemistry of fuels combustion. Through the use of combustion reaction networks (CRNs) analysis of degree centrality, principal species are identified during a combustion process by exploiting the introduced definition of principal species. A principal, central or the more active species of a combustion process, at a specific time step or cell of area/volume mesh, is the more tied up to other species in the CRN and so have the largest value of degree centrality. The accuracy of the dynamic identification of principal species, locally adapted to the thermochemical conditions at each time step/cell of the simulated combustion process, used by the employed directed relation graphs method of mechanisms reduction, is proved. The simulations were carried out using an adjusted dynamic adaptive chemistry approach of detailed chemistry implementing. It is demonstrated that an ‘active’ species in a combustion system would not necessary be considered as a part of important species set needed for its predictive simulations.     

Total Fluorescence Fingerprinting of Pesticides: A Reliable Approach for Continuous Monitoring of Soils and Waters

The present work relates to the creation/extension of a database of Total Excitation-Emission and Total Synchronous Fluorescence Matrices (TEEMs and TSFMs) along with optimal Synchronous Fluorescence Spectra (SFS) to fingerprint pesticides widely used in Morocco. This spectrometric multi-component fingerprinting may permit the direct detection of pesticides persisting in soil or water. The objective of the current investigation is to detect four pesticide remains in agricultural soils by applying the spectrometric fingerprinting results. They are the commercial: i) insecticide Axlera 5G (carbamate), ii) fungicide Orsalis 5% SC (triazole), iii) insecticide Force 0,5 G (pyrethrinoid) and iv) insecticide Proclaim 05 SG (non-assigned). The agricultural plantations monitored are located in the great agricultural Doukkala region at the western Atlantic side of Morocco, where these chemicals are in large sale and use.