bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of the alcohol extract of the seeds of Mucuna pruriens on free radicals and oxidative stress in albino rats
Authors: Tripathi Yamini B. , Upadhyay Anil K. 
Published: October 2002

AbstractIn vitro and in vivo studies were made with an alcohol extract of the seeds of Mucuna pruriens (Fabaceae) to investigate its antioxidant property. In vitro studies were carried out in rat liver homogenate to investigate the chemical interaction of various phytochemicals with different species of free radicals. The effect was also checked on iron‐induced lipid peroxidation, oxidation of GSH content, and its interaction with hydroxyl and superoxide radicals. There was no change on the rate of aerial oxidation of GSH content but it significantly inhibited FeSO4 induced lipid peroxidation. It also inhibited the specific chemical reactions induced by superoxides and hydroxyl radicals. The removal of these species was through direct chemical interaction. An in vivo study on albino rats for 30 days showed no toxic effect up to a dose of 600 mg/kg body weight, on oral administration. There was no change in the level of TBA‐reactive substances, reduced glutathione content and SOD activity in the liver. The activity of serum GOT, GPT and alkaline phosphatase was also unchanged. Thus it could be concluded that the alcohol extract of the seeds of M. pruriens has an antilipid peroxidation property, which is mediated through the removal of superoxides and hydroxyl radicals. Copyright © 2002 John Wiley & Sons, Ltd.
Glucose lowering efficacy of Ficus racemosa bark extract in normal and alloxan diabetic rats
Authors: Bhaskara Rao R. , Murugesan T. , Sinha Sanghamitra , Saha B. P. , Pal M. , Mandal Subhash C. 
Published: October 2002

AbstractThe glucose‐lowering efficacy of a methanol extract of the stem bark of Ficus racemosa Linn. (MEBFR) (Family Moraceae) was evaluated both in normal and alloxan‐induced diabetic rats. The MEBFR at the doses examined (200 and 400 mg/kg p.o.) exhibited significant hypoglycaemic activity in both experimental animal models when compared with the control group. The activity was also comparable to that of the effect produced by a standard antidiabetic agent, glibenclamide 10 mg/kg. The present investigation established pharmacological evidence to support the folklore claim that it is an antidiabetic agent. Copyright © 2002 John Wiley & Sons, Ltd.
In vitro Immunomodulatory activity of verbascoside from Nepeta ucrainica L.
Authors: Akbay Pinar , Calis Ihsan , Ündeger Ülkü , Basaran Nursen , Basaran A. Ahmet 
Published: October 2002

AbstractNepeta ucrainica L. is used as a herbal tea in Kazakhistan. Phytochemical investigations of the aerial parts of the plant resulted in the isolation of verbascoside (1) and 1,5,9‐epi‐deoxyloganic acid (2). The structures of the compounds were elucidated by spectral (UV, IR, 1H‐NMR and 13C‐NMR) methods and HPLC analysis. The in vitro immunomodulatory activity of verbascoside was investigated by assessing neutrophil function; chemotaxis and intracellular killing activity. Verbascoside showed an increased chemotactic activity in all doses applied compared with the medium used as a negative control and had a positive effect on respiratory burst of neutrophils, but there was an opposite effect with increasing doses, pointing to a possible suppression of neutrophil intracellular killing activity. Copyright © 2002 John Wiley & Sons, Ltd.
Process capability indices for skewed populations
Authors: Chang Young Soon , Choi In Su , Bai Do Sun 
Published: October 2002

AbstractThis paper proposes a new method of constructing process capability indices (PCIs) for skewed populations. It is based on a weighted standard deviation method which decomposes the standard deviation of a quality characteristic into upper and lower deviations and adjusts the value of the PCI using decomposed deviations in accordance with the skewness estimated from sample data. For symmetric populations, the proposed PCIs reduce to standard PCIs. The performance of the proposed PCIs is compared with those of standard and other PCIs, and finite sample properties of the estimates are investigated using Monte Carlo simulation. Numerical studies indicate that considerable improvements over existing methods can be achieved by the use of the weighted standard deviation method when the underlying distribution is skewed. Copyright © 2002 John Wiley & Sons, Ltd.
Systematic trends in E2 transitions along the sodium isoelectronic sequence
Authors: Charro E. , Martín I. 
Published: October 2002

AbstractOscillator strengths for E2‐forbidden spectral lines of sodium‐isoelectronic ions, from K IX (Z=19) to Cs XLV (Z=55), have been calculated in the LS‐coupling scheme using the relativistic quantum defect orbital (RQDO) method. The study of many of these sodiumlike ions is relevant to processes in fusion devices and in astrophysical objects. Our data are compared with the very few results available, and their systematic trend is analyzed for np 2P0–n′f 2F0 transitions. The influence of relativistic effects in E2 transitions along this sequence is also discussed. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001
Improved point‐charge model within the INDO/S‐CI method for describing the ligand excited states of lanthanide coordination compounds
Authors: Batista Hélcio J. , Longo Ricardo L. 
Published: October 2002

AbstractDue to the spatial extent of the 5s and 5p filled orbitals of lanthanide ions, the shielding of the nuclear charge is not perfect at close distances to the ion. Thus, ligand atoms should experience different effective charge depending upon their distance to the central ion. Using electrostatic arguments and ab initio calculations for Eu3+, we have proposed an improved model that describes the ion as an effective charge, q(r), whose value has the following radial dependence, q(r)=3+14e. This functional form of the point charge has been implemented into the ZINDO program and INDO/S‐CI calculations have been performed for the Eu(btfa)3bipy, Eu(btfa)3⋅2H2O, Eu(bzac)3bipy, and Eu(bzac)3⋅2H2O compounds. The comparison with the experimental absorption spectrum was used to optimize the exponent A parameter. Application of this model to several other Eu3+ coordination compounds yielded better results for the calculated absorption spectra than the fixed 3+ point‐charge model. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001
Hierarchical construction of finite diabatic sets by Mathieu functions
Authors: Englman R. , Yahalom A. , Baer M. 
Published: October 2002

AbstractAn extension is given for the standard two component model of adiabatic, Born–Oppenheimer (BO) electronic states in a polyatonic molecule, by use of Mathieu functions of arbitrary order. The curl or compatibility conditions for the construction of a diabatic set of states based on a finite‐dimensional subset of BO states are not satisfied exactly. It is shown, however, that, by successively adding higher order Mathieu functions to the BO set, the compatibility conditions are satisfied with increasingly better accuracy. We then generalize to situations in which the nonadiabatic couplings (the dynamic corrections to the BO approximation) are small (though not necessarily zero) between a finite‐dimensional BO subset and the rest of the BO states. We prove that approximate diabatic sets exist, with an error that is of the order of the square of the neglected nonadiabatic couplings. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001
Highly accurate Gaussian basis sets for some 14‐electron diatomic systems*
Authors: Neto A. Canal , Jorge F. E. , Centoducatte R. 
Published: October 2002

AbstractA molecular improved generator coordinate Hartree–Fock (HF) method is used to generate highly accurate Gaussian basis sets for N2, BF, CO, NO+, and CN−. For these molecular systems, sequences of basis sets of atom‐centred Gaussian‐type functions are employed to explore the accuracy achieved with this method. Our ground state HF total energies are lower than the corresponding ones calculated with other basis sets of primitive Gaussian‐type functions reported in the literature. For the molecular systems here studied, the differences between the HF total energy results obtained with our largest basis sets and with a numerical HF method are equals to 38.2, 13.9, 33.0, 76.7, and 55.7 μhartree for N2, BF, CO, NO+, and CN−, respectively. We have also calculated the multipole electric moments and compare them with the corresponding experimental values and with results computed by other approaches. © 2002 John Wiley & Sons, Inc. Int J Quantum Chem, 2002
Sulfur‐containing mesoionic compounds: Theoretical study on structure and properties
Authors: Fabian Jürgen , Hess B. Andes 
Published: October 2002

AbstractThe structure of the mesoionic 1,3‐dithiolylium‐4‐olate (2) and thiopyrylium‐3‐olate (3) and of their derivatives were calculated by first‐principles methods. The compounds are considered as cylic derivatives of open‐chain thione S‐ylides. The extent of cyclic electron delocalization was discussed in terms of the molecular charge distribution and nucleus‐independent chemical shift values (NICs). The calculated CS bond of SCO of 2 was found to be exceedingly long (>1.80 Å). This result suggests a facile CS ring opening of 2 to S‐ketenyl dithiomethylester. The transition structure of this reaction is nearly isoenergetic with the product of the reaction. The calculated reaction barrier amounts to about 12 kcal/mol and the ring‐to‐chain valence isomerization should therefore occur under thermal conditions. This result is in line with the chemical reactivity of diphenyl‐2. According to time‐dependent density functional theory calculations (TD‐DFT) the sulfur‐containing mesoionic compounds 2 and 3 should be colored. The intense long wavelength absorption of diphenyl‐2 at about 550 nm is well reproduced. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002
Ab initio study of bending modes in water cage clusters, (H2O)n, n6–10
Authors: Sadlej Joanna 
Published: October 2002

AbstractTheoretical investigation, employing MP2 level ab initio calculations, is presented of HOH bending modes in water cage clusters, (H2O)n, n6–10. The vibrational bending frequencies are blue‐shifted by 40–170 cm−1 with respect to H2O(g). The magnitude of bending frequency shift depends on the type of water molecules. The three coordinated water molecules with dangling H atoms (DAA) tend to have lower frequencies than do the three coordinated water molecules with dangling oxygen atom (DDA). In contrast to OH stretch, there is no evidence for strong changes in molecular dipole derivatives with respect to bending as a result of hydrogen bonding in the clusters. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002
Improved model core potentials: Application to the thermochemistry of organoxenon complexes
Authors: Lovallo Christopher C. , Klobukowski Mariusz 
Published: October 2002

AbstractWe recently developed new pseudopotentials for the main group elements, incorporating the L‐shell structure in the basis sets and reoptimizing the parameters. These improved model core potentials were used to study the energetics of reactions leading to compounds with XeIIC bonds. We found that many compounds are thermodynamically stable with respect to the reactants, and consequently they could possibly be formed under the right kinetic conditions. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002
Energies and widths of the resonance states of the He ion
Authors: Orlikowski Tadeusz 
Published: October 2002

AbstractResonance energies and widths are calculated for He in the X1 Σ electronic state using the lifetime matrix method. Nonadiabatic couplings with the first excited state are taken into account. The obtained energies are compared with some previous results. We found that for the considered system the nonadiabatic effects are small and lower the adiabatic energies by less than 0.5 cm−1. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002
Quantum mechanical and experimental infrared and Raman studies of 1‐methyluracil and its hydrogen‐bonded dimer
Authors: Person Willis B. , Szczepaniak Krystyna , Kwiatkowski Jozef S. 
Published: October 2002

AbstractDensity functional theory at the B3LYP/6‐31G(d,p) level has been used to calculate the structure, force field, and vibrational [infrared (IR) and Raman] spectra of the 1‐methyluracil monomer and its dimer with the cyclic N3H … OC4 hydrogen bonds. The experimental IR spectrum of the 1‐methyluracil monomer isolated in a low‐temperature Ar matrix and the IR and Raman spectra of its polycrystalline solid have been reinvestigated. The cyclic hydrogen bond for the calculated dimer is the same as that in the 1‐methyluracil crystal. It appears that calculation at this level of theory does provide IR and Raman spectra closely resembling the corresponding experimental spectra. We were amazed to find that the agreement between the calculated spectrum of the dimer and the experimental spectrum of the crystalline solid is not worse than the agreement between the calculated spectrum of the monomer and the experimental spectrum of 1‐methyluracil isolated in an Ar matrix. The results of calculation appear to be useful in the interpretation of the experimental spectra of the monomer and crystal. The close agreement found between the calculated and experimental spectra suggests that force constants and geometries of the monomer and dimer are also predicted well by the calculation at this level. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002
Normal mode analysis of the vibrational spectrum of tropolone—A molecule with seven‐membered ring
Authors: Rostkowska Hanna , Lapinski Leszek , Nowak Maciej J. , Adamowicz Ludwik 
Published: October 2002

AbstractInfrared spectra of tropolone (2‐hydroxy‐2,4,6‐cycloheptatriene‐1‐one) isolated in Ar and N2 matrices are compared with the spectra theoretically calculated at the DFT (density functional theory) Becke, Lee, Yang, Paar (B3LYP)/6‐31++G** and Møller–Plesset of the second order (MP2)/6‐31+G* levels. The good agreement between experimental spectrum and DFT results allowed assignment of the bands observed in the IR spectrum to the theoretically predicted normal modes described in terms of potential energy distribution (PED). Internal coordinates describing in‐plane and out‐of‐plane deformations of the seven‐membered ring of D7h symmetry (and for eight‐membered ring of D8h symmetry) were designed for the purpose of normal mode analysis. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002
New complete orthonormal sets of exponential‐type orbitals and their application to translation of Slater orbitals
Authors: Guseinov I. I. 
Published: October 2002

AbstractThe new complete orthonormal sets of exponential‐type orbitals (ETOs) are introduced in closed form as functions of the exponential, the complex or real regular solid spherical harmonic, and the generalized Laguerre polynomials,

where α=1,0,−1,−2,−3,… . These Ψα‐ETOs are represented as finite linear combinations of Slater‐type orbitals (STOs). The Coulomb Sturmian and Lambda ETOs are the special classes of Ψα‐ETOs for α=1 and α=0, respectively. By the use of Ψα‐ETOs the simpler expansion formulas for translation of STOs are derived. The translation coefficients are presented by a linear combination of overlap integrals. The final results are especially useful for machine computations of arbitrary multielectron multicenter molecular integrals over STOs that arise in the Hartree–Fock–Roothaan approximation and also in the Hylleraas correlated wave function method which play a significant role in theory and application to quantum mechanics of atoms, molecules, and solids. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002
Structural symmetry study of some bis‐adduct of an acceptor with two donors
Authors: Liao Hsin‐Yi , Chu San‐Yan 
Published: October 2002

AbstractThe protonated water dimer has a symmetric structure 1 in contrast to the asymmetric structure of protonated ammonia dimer 2. To make a general understanding of structural symmetry difference for these D–A–D systems, we carried out a systematic theoretical study with the B3LYP/6‐31+G** method. We considered the electron donors (D) of the lone pair on either side of BF, CO, and N2 molecules, as well as the electron acceptors (A) like Li+, CH3+, SiH3+, and PH2+ beside the proton. We found the magnitude of the first bonding energy between D and A [BE(1)] is decisive for the symmetry of the D–A–D system. A larger BE(1) leads to a smaller BE(2), the bonding energy of D–A with the second donor. This gives rise to a stronger tendency toward asymmetry. The magnitude of BE(1) correlates well with the difference in ionization potential (ΔIP) of the orbitals involved in the D–A interaction. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002
Ab initio and density functional theory calculations of the dipole polarizability and the second dipole hyperpolarizability of benzene
Authors: Soscún Humberto , Hernández Javier , Escobar Ramón , Toro‐Mendoza Carlos , Alvarado Ysaías , Hinchliffe Alan 
Published: October 2002

AbstractThe linear dipole polarizability α and nonlinear second dipole hyperpolarizability γ of benzene were calculated using the ab initio SCF–MO restricted Hartree–Fock (HF) method. The coupled perturbed HF and time‐dependent HF (TDHF) methods were used for the evaluation of the static and dynamic properties, respectively. The TDHF approach was applied at different optical frequencies, and the second hyperpolarizability γ was evaluated for different optical processes. Electron correlation was taken into account by using the Møller–Plesset perturbation theory (MP2) and the density functional theory B3LYP hybrid approach, with a finite field method, with electric fields of ±0.01, ±0.02, ±0.03, and ±0.04 a.u. used. Benzene was assumed to have a D6h geometry, and the standard STO/6‐31+G(d,p) (A) and optimized STO/6‐31+G(d*,p) (B) basis sets were employed for the calculations. In the optimized basis set, the d exponent of the C atomic function was varied in order to obtain a maximum static benzene γ at the TDHF level of theory. This optimized basis set was able to gives values for the (hyper)polarizabilities of benzene that agree excellently with experimental results and previous calculations. The calculated properties were analyzed in terms of the Laplacian of the electron density calculated using the atoms in molecules method due to Bader. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002
Quantum dynamical manifolds: Applications to excitonic coupled high temperature superconductivity
Authors: Scofield D. F. , Collins T. C. 
Published: October 2002

AbstractThe physical rationale supporting the introduction of many‐body differential geometric methods for self‐consistently calculating the properties of quantum systems is given. The methods are then used to determine new self‐consistent, self‐gauge field quantum dynamical manifold equations describing a high temperature superconductor. This includes itinerant electron screening of Coulomb repulsion and local electron, exciton‐mediated attraction. The article includes new quantum geometric equations for the paired electrons or holes (potential cooperons) of a superconductor. It is shown how other mechanisms can easily be incorporated into the calculation of the quasi‐particle geometry of the quantum dynamical manifold. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002
Quantum electrodynamical density‐matrix functional theory and group theoretical consideration of its solution
Authors: Ohsaku Tadafumi , Yamanaka Shusuke , Yamaki Daisuke , Yamaguchi Kizashi 
Published: October 2002

AbstractFor studying the group theoretical classification of the solutions of the density functional theory in relativistic framework, we propose quantum electrodynamical density‐matrix functional theory (QED–DMFT). QED–DMFT gives the energy as a functional of a local one‐body 4×4 matrix \documentclass{article}\pagestyle{empty}\begin{document}$Q(x)\equiv-\langle\psi(x)\bar{\psi}(x)\rangle$\end{document}, where \documentclass{article}\pagestyle{empty}\begin{document}$\psi$\end{document} and \documentclass{article}\pagestyle{empty}\begin{document}$\bar{\psi}$\end{document} are a 4‐component Dirac field and its Dirac conjugate, respectively. We examine some characters of QED–DMFT. After these preparations, by using Q(x), we classify the solutions of QED–DMFT under O(3) rotation, time reversal, and spatial inversion. The behavior of Q(x) under nonrelativistic and ultrarelativistic limits is also presented. Finally, we give plans for several extensions and applications of QED–DMFT. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002
Modified Slater potential and its application to the ground‐states and excited‐states of atomic systems
Authors: Harbola Manoj K. , Sen K. D. 
Published: October 2002

AbstractThe exact Slater potential (Slater, J. C. Phys Rev 1951, 81, 385) is calculated by treating the Fermi hole as a static charge distribution. However, the Fermi hole is a dynamic quantity and changes as an electron moves through an inhomogeneous electron gas. In this article, we follow the ideas of Harbola and Sahni (Phys Rev Lett 1989, 62, 489) to modify the Slater potential by adding to it a term that accounts for the dynamic nature of the Fermi hole in an approximate manner. The results obtained from this potential are shown to be highly accurate over a wide range of atomic systems. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002
Dissipative dynamics in many‐atom systems: A density matrix treatment
Authors: Micha David A. , Thorndyke Brian 
Published: October 2002

AbstractThe dynamics of a many‐atom system are described in terms of the density operator solution of the Liouville–von Neumann equation, for either isolated or dissipative (open) conditions. The treatment introduces a partial Wigner transform of the density operator of the isolated system or of a primary region of interest, respectively, classifying degrees of freedom as quantal or quasi‐classical. A secondary region (the medium) is treated as a stochastic environment leading to a dissipative dynamics of the primary region. Dissipative phenomena are described in terms of dissipative potentials and rate operators. The quantum and quasi‐classical degrees of freedom can be identified with the electronic and nuclear variables of a many‐atom system to provide a description of electronic rearrangement and excitations during dissipative phenomena. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002
Geometric picture for coupled electron–nuclear dynamics
Authors: Chernyak Vladimir , Mukamel Shaul 
Published: October 2002

AbstractEquations of coupled electron–nuclear dynamics (CEND) that describe molecular dynamics within a fully classical approach have been derived. Utilization of the language of fiber bundles and connections (gauge fields) allows one to represent the resulting classical Hamilton equations in an invariant (coordinate‐covariant) form. Applications of the CEND equations to calculations of off‐resonant nonlinear molecular polarizabilities are outlined. The CEND equations are shown to resemble the END equations derived earlier once the Thouless representation of single Slater determinants is adopted. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002