bluuebunny/crossref_metadata_2025_split huggingface dataset:
The value of power Doppler imaging to predict the histologic components of benign prostatic hyperplasia
Authors: Hayami Shinsuke , Ushiyama Tomomi , Kurita Yutaka , Kageyama Shinji , Suzuki Kazuo , Fujita Kimio 
Published: October 2002

AbstractBACKGROUNDThe response of symptoms caused by benign prostate hypertrophy (BPH) to alpha blockade is related to the area density of the smooth muscle of the prostate. If this density could be determined by ultrasound examination, ultrasound might be useful in predicting the efficacy of alpha‐blocker therapy. In this study, various ultrasonographic parameters obtained by transrectal method (TRUS) were compared with histologically measured components.METHODSBefore surgery, ultrasonic power Doppler imaging (PDI) of the prostate was performed using a transrectal probe. The volume of total prostate, transition zone (TZ), and the presumed circle area ratio (PCAR) [1,2] were calculated. Pulsatile blood flow was recorded, and the resistive index (RI) was calculated. Based on the serum concentration of total prostate specific antigen (PSA), ratio of PSA to prostate volume (PSAD), and ratio of PSA to TZ (PSAT) were calculated. Prostate tissues were obtained from 26 patients undergoing transurethral resection, suprapubic prostatectomy, or radical cystectomy, and were analyzed by quantitative morphometry. Computer image analysis was used to determine the mean area densities of the smooth muscle (SM), connective tissue (CT), glandular epithelium (GE) and lumen (GL), and vascular lumen (V). Correlations between ultrasonographic parameters and morphometric data were studied.RESULTSOn microscopic examination, the specimens showed a wide variety, ranging from normal prostate to typical glandular hyperplasia. There was a correlation between RI and the ratios of the four components (SM: r = −0.42 P = 0.034; CT: r = −0.42 P = 0.030; GE: r = 0.42 P = 0.032; GL: r = 0.46 P = 0.018). However, correlations between the other five transrectal parameters and the composition of the prostate were not so clear. This may have been because the blood vessels are compressed within the surgical capsule together with the urethra.CONCLUSIONSThe present study demonstrates that when RI is calculated by PDI, it can be quite useful for predicting component ratios, thereby making it possible to predict the therapeutic efficacy of alpha‐blockers in individual patients. Prostate 53: 168–174, 2002. © 2002 Wiley‐Liss, Inc.
Influence of solvent molecules on the stereochemical code of glycyl residues in proteins
Authors: Eswar Narayanan , Nagarajaram H.A. , Ramakrishnan C. , Srinivasan N. 
Published: October 2002

AbstractThe Ramachandran steric map and energy diagrams of the glycyl residue are symmetric. A plot of (ϕ,ψ) angles of glycyl residues in 250 nonhomologous and high‐resolution protein structures is also largely symmetric. However, there is a clear aberration in the symmetry. Although there is a cluster of points corresponding to the right‐handed α‐helical region, the “equivalent” cluster is clearly shifted to in and around the (ϕ,ψ) values of (90°, 0°) instead of being centered at the left‐handed α‐helical region of (60°, 40°). This lack of symmetry exists even in the (ϕ,ψ) distribution of residues from non‐α‐helical regions in proteins. Here we provide an explanation for this observation. An analysis of glycyl conformations in small peptide structures and in “coil” proteins, which are largely devoid of helical and sheet regions, shows that glycyl residues prefer to adopt conformations around (±90°, 0°) instead of right‐ and left‐handed α‐helical regions. By using theoretical calculations, such conformations are shown to have highest solvent accessibility in a system of two‐linked peptide units with glycyl residue at the central Cα atom. This finding is consistent with the observations from 250 nonhomologous protein structures where glycyl residues with conformations close to (±90°, 0°) are seen to have high solvent accessibility. Analysis of a subset of nonhomologous structures with very high resolution (1.5 Å or better) shows that water molecules are indeed present at distances suitable for hydrogen bond interaction with glycyl residues possessing conformations close to (±90°, 0°). It is suggested that water molecules play a key role in determining and stabilizing these conformations of glycyl residues and explain the aberration in the symmetry of glycyl conformations in proteins. Proteins 2002;49:326–334. © 2002 Wiley‐Liss, Inc.
Allosteric effects of chloride ions at the intradimeric α1β1 and α2β2 interfaces of human hemoglobin
Authors: Rujan Iulian N. , Russu Irina M. 
Published: October 2002

AbstractThe structural transition induced by ligand binding in human hemoglobin encompasses quaternary structure changes at the interfaces between the two αβ dimers. In contrast, the interfaces between α and β subunits within the same dimer (i.e., α1β1 and α2β2 interfaces) are structurally invariant. Previous work from this laboratory using NMR spectroscopy has identified four sites at the intradimeric α1β1 and α2β2 interfaces that, although structurally invariant, experience significant changes in the rates of proton exchange upon ligand binding. These sites are Hisα103(G10) and Hisα122(H5) in each α subunit of the hemoglobin tetramer. In the present work, we show that the proton exchange at the Hisα103(G10) sites is affected by the interactions of hemoglobin with chloride ions. Increasing concentrations of chloride ions at pH 6.45 and at 37°C enhance the exchange rate of the Hisα103(G10) Nε2 proton. The enhancement is greater in deoxygenated than in ligated hemoglobin. In the framework of the local unfolding model for proton exchange, these results suggest that the structural free energy and/or the proton transfer reactions at the Hisα103(G10) sites depend on the concentration of chloride ions. Therefore, the ligand‐induced changes at the Hisα103(G10) sites are modulated by the allosteric effect of chloride ions on hemoglobin. Proteins 2002;49:413–419. © 2002 Wiley‐Liss, Inc.
Emamectin, a novel insecticide for controlling field crop pests
Authors: Ishaaya Isaac , Kontsedalov Svetlana , Horowitz A Rami 
Published: October 2002

AbstractEmamectin is a macrocyclic lactone insecticide with low toxicity to non‐target organisms and the environment, and is considered an important component in pest‐management programmes for controlling field crop pests. It is a powerful compound for controlling the cotton bollworm Helicoverpa armigera (Hübner). A spray concentration of 25 mg AI litre−1 in a cotton field resulted in over 90% suppression of H armigera larvae up to day 28 after treatment, while similar mortality of the Egyptian cotton leafworm Spodoptera littoralis Boisduval, under the same conditions, was maintained for 3 days only. Emamectin is a potent compound for controlling the western flower thrips Frankliniella occidentalis (Pergande) under both laboratory and field conditions and its activity on adults was over 10‐fold greater than that of abamectin. Spray concentrations of 10 and 50 mg AI litre−1 in Ageratum houstonianum Mill flowers resulted in total suppression of adults up to day 11 and of larvae up to day 20 after treatment. Under standard laboratory conditions, emamectin exhibits a considerable activity on the whitefly Bemisia tabaci (Gennadius) and the leafminer Liriomyza huidobrensis (Blanchard). Further studies are required to evaluate its potential activity on the latter pests under field conditions.© 2002 Society of Chemical Industry
Dynamics of insecticide resistance in Bemisia tabaci: a case study with the insect growth regulator pyriproxyfen
Authors: Horowitz A Rami , Kontsedalov Svetlana , Denholm Ian , Ishaaya Isaac 
Published: October 2002

AbstractThe dynamics of pyriproxyfen resistance in Bemisia tabaci (Gennadius) have been studied intensively in cotton fields and greenhouses in Israel. High resistance to pyriproxyfen evolved one year after its introduction for use on flowers in greenhouses, after three successive applications. After ten years of pyriproxyfen use in cotton fields, with only one application per season, a high level of resistance was observed, but its rate of development differed among localities. It is hypothesized that these differences reflect temporal and spatial variations in the availability of alternative host plants for B tabaci, and that pyriproxyfen resistance evolved most readily in geographically isolated areas. It is also likely that the occurrence and development of resistance is partially biotype‐related. Pyriproxyfen use has ceased in high‐resistance localities, but in areas with low frequencies of resistance, cotton growers have continued to achieve acceptable control of B tabaci with pyriproxyfen. Due to the absence of applications of pyriproxyfen in some cotton fields, resistance levels tended to decline between 1998 and 2001. Laboratory experiments support the hypothesis that this decline reflects, in part, fitness costs associated with pyriproxyfen resistance.© 2002 Society of Chemical Industry
A comparative study of different crude extracts of Ocimum sanctum on noise stress
Authors: Archana R. , Namasivayam A. 
Published: October 2002

AbstractOur previous studies have shown that the ethanolic extract of Ocimum sanctum (OS) leaves was effective in alleviating the noise stress induced changes. Hence in this study, we have investigated the effectiveness of different types of crude OS extracts on some of the stress parameters after noies stress. The results of this study has shown that the active pinciple responsible for antistressor effect of ethanolic extract is also present in cold homogenised leaf extract of OS also. Hot extracts slightly decrease the potency of the active principle in normalizing corticosteroid level. Copyright © 2002 John Wiley & Sons, Ltd.
Keishi‐bukuryo‐gan preserves the endothelium dependent relaxation of thoracic aorta in cholesterol‐fed rabbit by limiting superoxide generation
Authors: Sekiya Nobuyasu , Goto Hirozo , Tazawa Kenji , Oida Shoko , Shimada Yutaka , Terasawa Katsutoshi 
Published: October 2002

AbstractFormerly, we have reported that keishi‐bukuryo‐gan prevents the progression of atherosclerosis in cholesterol‐fed rabbits and inhibits the free radical‐induced RBC haemolysis in rats.The present study was performed to investigate how keishi‐bukuryo‐gan (KBG) inhibits the early stage of atherosclerosis. Plasma lipid concentration and hydroxyl radical generation during respiratory burst in neutrophils were evaluated at the start and end of the study. The protective effect of KBG against endothelium disorder due to hypercholesterolaemia was examined. Twelve male Japanese white rabbits (2 kg body weight) were divided into two groups. Group A (n = 6) was fed standard rabbit chow containing 1% cholesterol for 4 weeks. Group B (n = 6) was fed standard rabbit chow containing 1% cholesterol and 1% KBG for 4 weeks. In the plasma lipid concentration, only the lipid peroxide concentration of group A was significantly higher than that of group B. At the end of the study, DMPO‐OH, the spin‐trapped adduct of hydroxyl radicals generated by neutrophils, was increased in both groups, and this increase was marked in group B. Endothelium‐dependent vasodilatation by acetylcholine increased significantly in group B compared with group A. Thus, KBG protects the vascular endothelium function by its antioxidative effect and by inhibiting the release of free radicals from neutrophils in vivo. Copyright © 2002 John Wiley & Sons, Ltd.
Combining preventive replacement and burn‐in procedures
Authors: Drapella Antoni , Kosznik Sylwia 
Published: October 2002

AbstractThis paper considers a non‐homogeneous population of items. Most of the items fail due to a wear‐out process. Therefore it is reasonable to employ a procedure of preventive maintenance. Some items, however, are of short life due to intrinsic defects. When used as replacement parts they may spoil results of planned prevention. The paper seeks for equilibrium of burn‐in and preventive replacement periods. Copyright © 2002 John Wiley & Sons, Ltd.
Partition experimental designs for sequential processes: Part II—second‐order models
Authors: Perry Leonard A. , Montgomery Douglas C. , Fowler John W. 
Published: October 2002

AbstractSecond‐order experimental designs are employed when an experimenter wishes to fit a second‐order model to account for response curvature over the region of interest. Partition designs are utilized when the output quality or performance characteristics of a product depend not only on the effect of the factors in the current process, but the effects of factors from preceding processes. Standard experimental design methods are often difficult to apply to several sequential processes. We present an approach to building second‐order response models for sequential processes with several design factors and multiple responses. The proposed design expands current experimental designs to incorporate two processes into one partitioned design. Potential advantages include a reduction in the time required to execute the experiment, a decrease in the number of experimental runs, and improved understanding of the process variables and their influence on the responses. Copyright © 2002 John Wiley & Sons, Ltd.
Autocorrelated process monitoring using triggered cuscore charts
Authors: Shu Lianjie , Apley Daniel W. , Tsung Fugee 
Published: October 2002

AbstractSome of the most widely‐investigated control charting techniques for autocorrelated data are based on time series residuals. If the mean shift in the autocorrelated process is a sudden step shift, the resulting mean shift in the residuals is time varying and has been referred to as the fault signature. Traditional residual based charts, such as a Shewhart, CUSUM, or EWMA on the residuals, do not make use of the information contained in the dynamics of the fault signature. In contrast, methods such as the Cuscore chart or Generalized Likelihood Ratio Test (GLRT) do incorporate this information. In order for the Cuscore chart to fully benefit from this, its detector coefficients should coincide with the fault signature. This is impossible to ensure, however, since the exact form of the fault signature depends on the time of occurrence of the mean shift, which is generally not known a priori. Any mismatch between the detector and the fault signature will adversely affect the Cuscore performance. This paper proposes a CUSUM‐triggered Cuscore chart to reduce the mismatch between the detector and fault signature. A variation to the CUSUM‐triggered Cuscore chart that uses a GLRT to estimate the mean shift time of occurrence is also discussed. It is shown that the triggered Cuscore chart performs better than the standard Cuscore chart and the residual‐based CUSUM chart. Examples are provided to illustrate its use. Copyright © 2002 John Wiley & Sons, Ltd.
INDO/S parameters for gold
Authors: Shapley Warwick A. , Reimers Jeffrey R. , Hush Noel S. 
Published: October 2002

AbstractTwo INDO/S parameter sets, designed for use in conjunction with 6s and 6s+6p+5d basis sets, have been determined for gold. These basis sets are comprised of Slater‐type orbitals with exponents chosen to best reproduce the radial expectation values r, r2, and r3 of the gold Hartree–Fock atomic orbitals. The adjustable parameters in the model were optimized to maximize agreement with experimental atomic ionization potentials and electron affinities, molecular ionization potentials and dipole moments obtained using density‐functional theory, and molecular excitation energies obtained using multireference configuration interaction methods. For the 6s basis, the optimal value of the (only) freely adjustable parameter βs is −2.5 eV while for the larger basis we determine βs=−4.0 eV and βd=−50.0 eV. We find the small basis set to be most appropriate for calculations on very large clusters and for dipole moment analysis, while the large basis is most appropriate for small complexes and spectral simulation. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001
Calculation of matrix elements in relativistic quantum mechanics
Authors: Ilarraza‐Lomelí A. C. , Valdés‐Martínez M. N. , Salas‐Brito A. L. , Martínez‐y‐Romero R. P. , Núñez‐Yépez H. N. 
Published: October 2002

AbstractEmploying a relativistic version of a hypervirial result, recurrence relations for arbitrary nondiagonal radial hydrogenic matrix elements have recently been obtained in Dirac relativistic quantum mechanics. In this contribution honoring Professor Löwdin, we report on a new relation we have recently discovered between the matrix elements 〈2∣rλ∣1〉 and 〈2∣βrλ∣1〉—where β is a Dirac matrix and the numbers distiguish between different radial eigenstates—that allow for a simplification and hence for a more convenient way of expressing the recurrence relations. We additionally derive another relation that can be employed for simplifying two‐center matrix element calculations in relativistic atomic or molecular calculations. © 2002 John Wiley & Sons, Inc. Int J Quantum Chem, 2002
Ab initio calculations and modeling of three‐body forces in Ar2H2O
Authors: Burcl Rudolf , Szczȩśniak M. M. , Kłos Jacek , Chałasiński Grzegorz , Cybulski Sławomir M. 
Published: October 2002

AbstractThe nonadditive interactions in the Ar2H2O cluster, in a variety of geometries, are studied using the supermolecular Møller–Plesset (MP) perturbation theory in conjunction with the perturbation theory of intermolecular forces. The three‐body effect is dissected into several components: the Heitler–London exchange, induction, dispersion, and second‐order supermolecular MP perturbation nonadditivity. The latter term is further analyzed within the framework of pseudodimer treatment. The Heitler–London exchange is dissected into the SE (single exchange) and TE (triple exchange) parts. Analytical representations of the nonadditive terms are discussed. For the exchange (SE) and induction, the multicenter expansions work very well. However, in the case of the three‐body dispersion term, the single‐center dipole‐dipole‐dipole plus dipole‐dipole‐quadrupole expression proves to be more suitable. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002
Ab initio calculations and modeling of three‐dimensional adiabatic and diabatic potential energy surfaces of F(2P)···H2(1Σ+) Van der Waals complex
Authors: Kłos Jacek , Chałasiński Grzegorz , Szczȩśniak M. M. 
Published: October 2002

AbstractThree lowest diabatic potential energy surfaces for the F(2P) + H2 Van der Waals complex are derived from accurate ab initio calculations of the T‐shaped (C2v) and collinear geometries (C∞v), at the coupled‐cluster single, double, and noniterative triple excitations [CCSD(T)] level of theory with a large basis set. For the intermediate geometries the angular dependence is modeled by a simple Legendre‐polynomial interpolation. The nonadiabatic coupling (off‐diagonal derivative) matrix element, and the fourth, off‐diagonal, diabatic surface are determined by separate multireference configuration interaction (MR‐CI) calculations with a somewhat smaller basis set. Three adiabatic potential energy surfaces (PESs) are also obtained, by diagonalizing the total Hamiltonian in the diabatic basis. Both the nonrelativistic and relativistic (including spin‐orbit coupling) PESs are evaluated. They are found to be in very good agreement with the entrance channel of the ASW PESs (Alexander, Manolopoulos, and Werner, J Chem Phys 2000, 113, 11084). The dependence of the PESs on the H2 stretching coordinate is also incorporated and analyzed. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002
Artificial molecules
Authors: Jaskólski W. , Bryant G. W. , Planelles J. , Zieliński M. 
Published: October 2002

AbstractDouble semiconductor nanocrystals, called artificial molecules by analogy to artificial atoms (quantum dots), are investigated. Empirical tight‐binding and k · p theories are used to obtain electronic structure, charge density distributions, and optical absorption spectra for single and double nanocrystals. We show how the bonding and antibonding molecular orbitals are formed from the wavefunctions of individual nanocrystals when the nanocrystals are joined together to form an artificial molecule. Formation of quantum dot lattices and interpretation of experimental data for close‐packed solids of nanocrystals are discussed. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002
Partitioning technique and transport across molecular interfaces: Many‐body effects
Authors: Mujica Vladimiro , Ratner Mark A. , Goscinski Osvaldo 
Published: October 2002

AbstractWe review the theory of transport across molecular interfaces within the framework of the partitioning and inner projection techniques, developed by Per‐Olov Löwdin. Using a one‐particle approximation to the many‐body equation for the current in a system consisting of a molecular bridge and two electrodes, it is shown that the idea of partitioning can be used advantageously to define a self‐energy that contains the coupling of the molecule to the electrodes. Inner projections are then introduced as a systematic way of including electron correlation effects in the transport across molecular junctions. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002
On the interaction between manganese cation (Mn2+) and the nucleic acid bases (T, U, C, A, G) in the gas phase
Authors: Russo Nino , Sicilia Emilia , Toscano Marirosa , Grand Andrè 
Published: October 2002

AbstractThe coordination modes, the equilibrium geometrical structures, and the gas‐phase metal ion affinity for the Mn2+ metal cation interacting with uracil, thymine, cytosine, adenine, and guanine were determined considering different low energy tautomers for the free nucleic acid bases and by using the density functional theory. For uracil and thymine, the mono‐coordinated complexes coming from the metalation of the oxo tautomers are not minima, whereas the manganese ion forms stable compounds with high energy tautomers for which the bi‐coordination is possible. Also for cytosine, adenine, and guanine the bi‐coordination is the favored binding mode. Despite the cytosine and guanine free bases have different tautomers lying in a very narrow range of energy, the stabilities of the corresponding metalated complexes differ significantly. A reverse situation occurs for uracil and thymine for which we obtain manganese complexes of comparable stability, while the tautomeric forms of the isolated free bases are well separated in energy. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002
Cumulant 2‐matrix of the high‐density electron gas and the density matrix functional theory
Authors: Ziesche P. 
Published: October 2002

AbstractThe cumulant 2‐matrix χ is that part of the two‐body reduced density matrix γ2, which cannot be reduced to products of the one‐body reduced density matrix (1‐matrix) γ. This irreducible part χ is calculated perturbatively for the high‐density electron gas (EG) in its ground state, such that the pair densities and the interaction energy are correctly reproduced in their high‐density limits, which are exactly known and summarized here. From the thus available cumulant 2‐matrix the pair density in momentum space can be derived and used for a fluctuation analysis and compared with the analog analysis in position space, where it is concluded that “correlation suppresses fluctuations”. The perturbatively available cumulant 2‐matrix χ can be used also for the high‐density electron gas to start the iterative solution of the Yasuda integral equation of density matrix functional theory (DMFT), which is a nonlinear functional relation between the cumulant 2‐matrix χ and the 1‐matrix γ recently derived from the contracted Schrödinger equation approach: χY[γ]. From the perturbatively determined χ one can find another functional χ[γ] as an alternative approximation for a DMFT. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002