Listar QFA_Articles por fecha de publicación
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Two state reactivity mechanism for the rearrangement of hydrogen peroxynitrite to nitric acid
Elsevier (2008)For the isomerization of HOONO to nitric acid, a spin triplet reactive intermediate <sup>3</sup>HOONO<sup>*</sup> was identified on a two state reactivity (TSR) potential energy surface. This bi-radical is postulated as ... -
Ionic liquids in separation techniques
Elsevier (2008)The growing interest in ionic liquids (ILs) has resulted in an exponentially increasing production of analytical applications. The potential of ILs in chemistry is related to their unique properties as non-molecular solvents: ... -
Direct quantification of steroid glucuronides in human urine by liquid chromatography-electrospray tandem mass spectrometry
Elsevier (2008)A method based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the direct quantification of glucuronides of testosterone (TG), epitestosterone (EPG), androsterone (AG) and etiocholanolone (ETG) has been ... -
Pesticide residues and transformation products in groundwater from a Spanish agricultural region on the Mediterranean Coast
Taylor & Francis (2008)An overview is given on the presence and changes over time of pesticide residues in groundwater from the Valencia region, one of the most important citrus cultivation sites of southern Europe. A multiresidue LC-MS/MS ... -
Isospin phases of vertically coupled double quantum rings under the influence
American Physical Society (2008)Vertically coupled double quantum rings submitted to a perpendicular magnetic field B are addressed within the local spin-density-functional theory. We describe the structure of quantum ring molecules containing up to 40 ... -
Intercalation processes and diffusion paths of lithium ions in spinel-type structured Li1+xTi2O4: density functional theory study
American Physical Society (2008)Intercalation processes and corresponding diffusion paths of Li ions into spinel-type structured Li1+xTi2O4 0 x 0.375 are systematically studied by means of periodic density functional theory calculations for different ... -
Crystal structure and theoretical study of IR and 1H and 13C NMR spectra of cordatin, a natural product with antiulcerogenic activity
Wiley (2008)Cordatin is a furan diterpenoid with a clerodane skeleton isolated from Croton palanostigma Klotzsch (Euphorbiaceae). This natural product shows significant antiulcerogenic activity, similar to cimetidine (Tagamet®), a ... -
Understanding reaction mechanisms in organic chemistry from catastrophe theory applied to the electron localization function topology
American Chemical Society (2008)Thomʼs catastrophe theory applied to the evolution of the topology of the electron localization function (ELF) gradient field constitutes a way to rationalize the reorganization of electron pairing and a powerful tool for ... -
Investigating the presence of pesticide transformation products in water by using liquid chromatography-mass spectrometry with different mass analyzers
John Wiley & Sons (2008)Many pesticide transformation products (TPs) can reach environmental waters as a consequence of their normally having a higher polarity than their parent pesticides. This makes the development of analytical methodology ... -
Tetranuclear Lanthanide Aqua Hydroxo Complexes with Macrocyclic Ligand Cucurbit[6]uril
WILEY-VCH Verlag (2008)Tetranuclear lanthanide aqua hydroxo complexes with two structural types of core – {Ln4(μ3-OH)4(μ2-OH)4}4+ [Ln = Pr (1), Nd (2), Eu (3), Gd (4), Tb (5)] and {Ln4(μ3-OH)4(μ2-OH)2}6+ [Ln = Er (6), Yb (7)] – were prepared by ... -
Combined 13C NMR and DFT/GIAO studies of the polyketides Aurasperone A and Fonsecinone A
Wiley (2008)Structural characterization by NMR spectroscopy and DFT calculations was performed for two dimeric naphtho-γ-pyrones, the polyketides Aurasperone A and Fonsecinone A. Experimental data (13C NMR chemical shifts and interatomic ... -
Characteristic molecular properties of one-electron double quantum rings under magnetic fields
Institute of Physics (2008)The molecular states of conduction electrons in laterally coupled quantum rings are investigated theoretically. The states are shown to have a distinct magnetic field dependence, which gives rise to periodic fluctuations ... -
Fast determination of toxic diethylene glycol in toothpaste by ultra-performance liquid chromatography–time of flight mass spectrometry
Springer Verlag (2008)A rapid method for determining diethylene glycol (DEG) in toothpaste based on the use of ultraperformance liquid chromatography (UPLC) coupled to time-of-flight mass spectrometry (TOF-MS) has been developed. The method ... -
An electron localization function and catastrophe theory analysis on the molecular mechanism of gas-phase identity SN2 reactions
Springer Verlag (2008)A set of four reactions, XCH3+X− (X=F, Cl, Br) and ClSiH3+Cl−, is investigated by means of the joint use of the electron localization function (ELF) and catastrophe theory (CT) analysis in order to obtain newinsights ... -
A Quantum Mechanics / Molecular Mechanics Study of the Protein-Ligand Interaction of two potent inhibitors of human O-GlcNAcase: PUGNAc and NAG-thiazoline
American Chemical Society (2008)O-glycoprotein 2-acetamino-2-deoxy-β-D-glucopyranosidase (O-GlcNAcase) hydrolyzes 2-acetamido-2-deoxy-β-D-glucopyranose (O-GlcNAc) residues of serine/threonine residues of modified proteins. O-GlcNAc is present in many ... -
Development and validation of a method to determine amoxicillin in physiological fluids using micellar liquid chromatography
Wiley-Blackwell (2008)A simple and robust method was developed for the routine identification and quantification of amoxicillin by micellar liquid chromatography. Amoxicillin, a β-lactamase inhibitor, is one of the most commonly prescribed ... -
Theoretical site-directed mutagenesis. The Asp168Ala mutant of L-Lactate Dehydrogenase
Royal Society (Gran Bretanya) (2008)The reduction of pyruvate to lactate catalyzed by the L-Lactate dehydrogenase has been studied in this paper by means of hybrid Quantum Mechanical / Molecular Mechanical simulations. A very flexible molecular model ... -
Strain behavior of lanthanum modified BiFeO3 thin films prepoared via soft chemical method
American Institute of Physics (2008)Pure and lanthanum modified BFO LaxBi1−xFeO3, x=0.0, 0.08, 0.15, 0.30 thin films were fabricated on Pt 111 /Ti/SiO2 / Si substrates by the soft chemical method. The effect of La substitution on the structural and ... -
Characterization of the Salinisation Processes in Aquifers Using Boron Isotopes; Application to South-Eastern Spain
Springer Netherlands (2008)Use of δ11B provides a solid tool for discriminating hydrogeochemical processes in complex coastal aquifers. Its efficiency increases markedly when it is applied along with other major or minor constituents. Nevertheless, ... -
Origin of the absorption maxima of the photoactive yellow protein resolved via ab initio multiconfigurational methods
American Chemical Society (2008)We discuss the role of the protein in controlling the absorption spectra of photoactive yellow protein (PYP), the archetype xanthopsin photoreceptor, using quantum mechanics/molecular mechanics (QM/MM) methods based on ab ...