Search results for " Affinity"
showing 10 items of 188 documents
A Comparative Analysis of the Electrophilicity of Organic Molecules between the Computed IPs and EAs and the HOMO and LUMO energies
2007
[EN] The electrophilicity index, omega, of a series of substituted ethylenes used in some relevant organic reactions has been evaluated from the ionization potential JP) and the electron affinity (EA) computed by vertical ionization at the B3LYP/aug-cc-PVTZ level. The corresponding electrophilicity values are well correlated with those obtained from the HOMO and LUMO energies of the neutral molecules. The good linear correlation found between omega(I,A) and omega(H,L)(LBS), and between omega(H,L)(LBS) and omega(H,L)(SBS) allows to confirm the use of the easily available B3LYP/6-31G(*) HOMO and LUMO energies to obtain reasonable values of the global electrophilicity index of organic molecule…
A semi-empirical extrapolation technique for atomic and molecular properties derived from correlated wavefunctions
1976
Abstract A semi-empirical extrapolation technique is suggested for recovering the correlation defect remaining in atomic and molecular properties calculated from highly correlated wavefunctions. These procedures are applied to PNO-CEPA and PNO-IPPA calculations on F, F + , F − , and HF in order to obtain “exact” estimates of the ionization potential, electron affinity, and dissociation energy.
Soluble oligo(phenylenevinylene)s with electron withdrawing substituents for the use in light emitting diodes
2000
Poly(p-phenylenevinylene) (PPV) and its derivatives are one of the most widely used classes of phosphors in light emitting diodes. Central problems are the imbalanced charge carrier injection and transport properties due to the high lying conduction band. A series of good soluble oligo(phenylenevinylene)s (OPV) with five benzene rings and a variety of electron withdrawing and accepting substituents have been prepared and may serve as model compounds for PPV with increased electron affinity. The central ring of the OPVs is substituted with two octyloxy groups to ensure good solubility and the lateral styrene units carry further chromophoric groups of different electronic character. The synth…
An automatic multidimensional chromatography system for purification of human uterine progesterone receptor and induction of polyclonal antibodies.
1986
Abstract This paper reports on the synthesis of Org2058-bonded microparticulate silicas and their use in affinity chromatography as the first step for the purification of human progesterone receptor. The development of microprocessor-controlled instruments allows all the various steps to be performed automatically. The various steps used for the purification of human progesterone receptor were carried out with the FPLC system: (1) affinity chromatography, (2) desalting of eluate on Sephadex G-25, (3) anion-exchange chromatography using a Mono Q column. With this procedure the receptor was purified approx. 10,000-fold within 24 h. The yield of receptor was generally 85–95%. Investigations wi…
Optical studies on the specific interaction of dipyridamole with alpha 1-acid glycoprotein (orosomucoid).
1982
Abstract The interaction of dipyridamole with α1-acid glycoprotein was investigated by circular dichroism and ultraviolet absorbance measurements as well as by equilibrium dialysis experiments. Dipyridamole is bound to the protein via one site of extremely high affinity and by at least one site of considerably lower affinity. Only the association of dipyridamole with the high affinity site produces typical extrinsic Cotton effects. As a result of experimental observations it is concluded that the high affinity site is located in a hydrophobic protein structure of the glycoprotein.
Strategies for improving production and purification of a recombinant protein: rP30 of Toxoplasma gondii expressed in the yeast Schizosaccharomyces p…
2007
Abstract Many problems concerned with the production and the purification of recombinant proteins must be addressed prior to launching an industrial production process. Among these problems, attention is focused on low-level expression that complicates the purification step and can jeopardise the process. The expression of a membrane protein, rP30, of Toxoplasma gondii in the yeast Schizosaccharomyces pombe led to a secretion of only 0.5 μg ml−1. In order to obtain a sufficient quantity for biochemical characterization and evaluation in vitro diagnostic test development, strategies for both production and purification had to be optimized. First, the influence of four nitrogen sources (three…
Chiral separation of oxprenolol by affinity electrokinetic chromatography-partial filling technique using human serum albumin as chiral selector
2005
The intrinsic characteristics of capillary electrophoresis have made this technique a powerful tool in the chiral separation field. The present paper deals with the enantiomeric separation of oxprenolol enantiomers by affinity electrokinetic chromatography-partial filling technique using human serum albumin (HSA) as chiral selector. Several experimental conditions and variables affecting the separation such as pH, HSA concentration and plug length, background electrolyte concentration, temperature and voltage were studied. Baseline separation of oxprenolol enantiomers was obtained in less than 8 min under the following selected conditions: electrophoretic buffer composed of 50 mM Tris-(hydr…
Evaluation of Structural and Temporal Properties of Ego Networks for Data Availability in DOSNs
2017
The large diffusion of Online Social Networks (OSNs) has influenced the way people interact with each other. OSNs present several drawbacks, one of the most important is the problem of privacy disclosures. Distributed Online Social Networks (DOSNs) have been proposed as a valid alternative solution to solve this problem. DOSNs are Online Social Networks implemented on a distributed platform, such as a P2P system or a mobile network. However, the decentralization of the control presents several challenges, one of the main ones is guaranteeing data availability without relying on a central server. To this aim, users’ data allocation strategies have to be defined and this requires the knowledg…
Nanomaterials and new biorecognition molecules based surface plasmon resonance biosensors for mycotoxin detection
2019
Mycotoxins are highly toxic secondary metabolites, which may contaminate many types of food and feeds. These toxins have serious health risks for both human and animals. One of the effective ways to prevent food contamination and protect people against mycotoxins is based on timely detection. Several methods like enzyme-linked immunosorbent assay and affinity chromatography are commercially available for this purpose. Nevertheless, sensitive, fast, simple, low-cost, and portable devices are absolutely required for a fast point-of care information and making decisions. Application of biosensors appears to be a possible technique to meet this need for mycotoxins analyze. The present study has…
A G2 study of H3BXHn (X=N, O, F, P, S, and Cl) donor–acceptor complexes
1999
Abstract Complexation energies of H3BXHn complexes (X=N, O, F, P, S, and Cl; n=1, 2, 3) have been computed at the G2 level of theory. G2 results show that the H3BXH3 (X=N, P) complexes are more stable than H3BXH2 (X=O, S) and H3BXH (X=F, Cl) ones. This stability was related completely either to the nature of donor compounds, and to the pyramidalization of the monoborane. Two linear correlations were established. The first one is between experimental proton affinity of the XHn donor compounds, and complexation energies of the H3BXHn complexes. The second correlation is between the ∠HBH bond angles and the complexation energies of the H3BXHn complexes calculated at the G2 level of theory.