bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surface‐ and deep‐level diversity in workgroups: examining the moderating effects of team orientation and team process on relationship conflict
Authors: Mohammed Susan , Angell Linda C. 
Published: November 2004

AbstractThe increased use of teams in organizations, coupled with an increasingly diverse workforce, strongly suggests that we should learn more about how team diversity affects functioning and performance. The purpose of this study was to explore the differential impact of surface‐level diversity (gender, ethnicity), deep‐level diversity (time urgency, extraversion), and two moderating variables (team orientation, team process) on relationship conflict over time. Hypotheses were tested by tracking 45 student project teams in a longitudinal design. Results revealed that team orientation and team process moderated the diversity–conflict link. Specifically, team orientation helped to neutralize the negative effects of surface‐level (gender) diversity on relationship conflict. In a similar manner, team processes worked to weaken the deleterious effects of deep‐level diversity (time urgency) on relationship conflict. In addition, relationship conflict resulted in lower perceived performance by team members. Copyright © 2004 John Wiley & Sons, Ltd.
Client–project manager engagements, trust, and loyalty
Authors: Webber Sheila Simsarian , Klimoski Richard J. 
Published: November 2004

AbstractThis study addresses the behaviors of project managers under various conditions of cognitive and affective trust, and the implications for obtaining client loyalty. Theoretical foundations were drawn from interpersonal and interorganizational trust literature. A test of the proposed theoretical framework was conducted in a field setting utilizing a matched design of both project managers and their clients. The results show that reliable project performance positively impacted client loyalty intentions and service‐oriented OCBs positively impacted client secondary retention. An interaction showed that in low cognitive trust situations the project manager behavior of reliable project performance facilitated the obtainment of client loyalty intentions. Implications for research and practice are discussed. Copyright © 2004 John Wiley & Sons, Ltd.
Electro‐reaction‐diffusion systems with nonlocal constraints
Authors: Glitzky A. 
Published: November 2004

AbstractThe paper deals with equations modelling the redistribution of charged particles by reactions, drift and diffusion processes. The corresponding model equations contain parabolic PDEs for the densities of mobile species, ODEs for the densities of immobile species, a possibly nonlinear, nonlocal Poisson equation and some nonlocal constraints. Based on applications to semiconductor technology these equations have to be investigated for non‐smooth data and kinetic coefficients which depend on the state variables.In two space dimensions we discuss the steady states of the system, we prove energy estimates, global a priori estimates and give a global existence result. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A strongly degenerate diffusion equation with strong absorption
Authors: Winkler Michael 
Published: November 2004

AbstractIt is shown that the Cauchy problem in ℝ for the strongly degenerate parabolic equation

has a nonnegative weak solution for any nonnegative bounded continuous initial datum, provided that q ≤ p – 1, while there is no (continuous) weak solution for q > p – 1. The evolution of the spatial positivity set {u(t) > 0}, continuity of the free boundary and the extinction rate are also investigated. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A finite element formulation of the outlet gradient boundary condition for convective–diffusive transport problems
Authors: Cornaton Fabien , Perrochet Pierre , Diersch Hans‐Jörg 
Published: November 2004

AbstractA simple finite element formulation of the outlet gradient boundary condition is presented in the general context of convective–diffusive transport processes. Basically, the method is based on an upstream evaluation of the dependent variable gradient along open boundaries. Boundary normal unit vectors and gradient operators are evaluated using covariant bases and metric tensors, which allow handling finite elements of mixed dimensions. Even though the presented method has implications for many fields where diffusion processes are involved, discussion and illustrative examples address more particularly the framework of contaminant transport in porous media, in which the outlet gradient concentration is classically, but wrongly assumed to be zero. Copyright © 2004 John Wiley & Sons, Ltd.
Natural orbital functional for correlation in polymers
Authors: Piris Mario , Otto Peter 
Published: November 2004

AbstractWe extend a natural orbital functional to calculate correlation energies for periodic polymers. We generalize the proposed correlation matrix in a two‐particle reduced density matrix to achieve a size‐consistent functional. Because of the linearity in two‐electron integrals, our functional does not behave properly for weakly interacting systems. We separate the Coulomb operator into two parts and consider only the short‐range operator for the two‐electron integrals in the correlation term of the energy functional. The long‐range interactions will be included in the future development of the functional to consider dispersion interactions. Application is made to alternating trans‐polyacetylene. The experimentally observed reduction of the Hartree–Fock lattice spacing by the inclusion of electron correlation is correctly predicted. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Surface energies of simple metals from slabs: Comparison of exchange‐correlation density functionals
Authors: Fiolhais Carlos , Almeida L. M. 
Published: November 2004

AbstractSurface energies of some simple metals (Be, Al, Mg, Li, and Na) were calculated within density functional theory. Various approximations for the exchange and correlation were tested: local density approximation (LDA), generalized gradient approximations (GGA), and meta–generalized gradient approximation (MGGA). We used the Crystal98 code to calculate slabs with one to 10 layers using both all‐electron and pseudopotential approaches. The extraction of the surface energy from the series of slab energies was done by the linear‐fitting method. Our LDA and GGA results agree reasonably well with those from other authors. The MGGA values are, in general, close to LDA and higher than GGA ones, a pattern also observed in the jellium model. They also agree reasonably well with the experimental data. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Fractional occupation number approaches for CAS (2,2) systems based on second‐order density
Authors: Takeda Ryo , Yamanaka Shusuke , Yamaguchi Kizashi 
Published: November 2004

AbstractIn previous work, we applied a fractional occupation number (FON) approach within density functional theory (DFT) for twisted methylene and found that the applicability of FON‐DFT is limited for the neighborhood of the completely degenerate state, implying the necessity of the second‐order density (SOD) expression of the energy functional. In the succeeding work, we have derived the exact expression of SOD of CAS (2,2) by the natural orbitals (NOs) and their occupation numbers, which we call “one‐body representation of second‐order density” (ORSOD). We present here the FON scheme based on ORSOD by directly optimizing the NOs and their occupation numbers. In contrast to the previous FON‐DFT, this FON scheme is found to work well, in particular, the dissociation limit of the heteronuclear systems, showing that this scheme can be an alternative for complete active space self‐consistent field (2,2) methods for such cases. The current scheme provides a guideline for extension and approximations of the FON scheme to investigate mesoscopic systems with large active space. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Multiscale modeling of polymers on a surface: From ab initio density functional calculations of molecular adsorption to large‐scale properties
Authors: Delle Site Luigi , Kremer Kurt 
Published: November 2004

AbstractBy combining ab initio density functional calculations and polymer coarse‐grained models we study the interplay of adsorption energy and conformational entropy for polymer systems in contact with a surface. The central idea is to divide the chain or even the monomers into submolecules small enough to allow an ab initio study of molecular adsorption at the surface. By making appropriate considerations, this can then be incorporated into a coarse‐grained model for the polymer–surface interaction. The modeling procedure consists of applying a qualitative adsorption mechanism together with coarse‐grained polymer conformations. The main advantage of such an approach is that direct potential parameterizations are not required and that for the current purpose ab initio calculations are sufficiently accurate. Our method is rather general and can be applied to a large class of polymers interacting with surfaces. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Study of radical defects in crystalline lattices from first‐principles molecular dynamics simulations
Authors: Van Speybroeck V. , Pauwels E. , Stevens F. , Callens F. , Waroquier M. 
Published: November 2004

AbstractTheoretical calculations are presented to determine the structure of radical defects in crystalline lattices. The applications are concentrated on radical defects as they are induced by irradiation in organic crystals and paramagnetic molecular ions embedded in alkali halide lattices. Various approaches are possible to model the molecular environment: the single‐molecule approach, the cluster approach, and periodic calculations. The latter are based on a Car–Parrinello formalism in which the molecular orbitals are expanded in a plane‐wave basis set and in which the optimized structures at 0 K are obtained by a simulated annealing technique. The pros and cons of the various approaches are highlighted, and where possible comparison with experimental electron paramagnetic resonance data are given. Due to the different natures of ionic and organic crystals, specific computational procedures are needed to get good correspondence with the experimental data. In various cases there is experimental evidence that some radical structures are submitted to noticeable changes with increasing temperature. These effects were theoretically reproduced by performing molecular dynamics calculations at elevated temperatures. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Optimized effective potential method at finite temperature: An application to superconductivity
Authors: Shigeta Yasuteru 
Published: November 2004

AbstractTo deal with superconductivity without introducing an external pairing potential we extend the effective potential methodology into that at finite‐temperature cases, starting from Green's function theory based on the Sham–Schlüter (SS) equation. This extension corresponds to a Kohn–Sham–Bogoliubov equation that includes electron exchange‐correlation effects. Then we linearize the Dyson equation with respect to the anomalous Green function and adopt a linear response approximation to the SS equation. Numerical calculation is performed with a model Hamiltonian within the exchange‐only case. We compare the results obtained by the present optimized potential method with those by the exact Hartree–Fock–Bogoliubov method and confirm a good performance of the present method. We evaluate anomalous effective exchange potentials resulting from purely positive electron interactions and observe the singlet superconducting state due to multiband effects. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Bonding properties of the new zintl‐phase hydrides
Authors: Orgaz Emilio , Aburto Andrea 
Published: November 2004

AbstractWe investigated the electronic structure of three recently discovered Zintl‐phase hydrides: SrAl2H2, Ca3SnH2, and Ca5Sn3H. The energy bands and the total and partial densities of states were computed by means of the full‐potential linearized augmented‐plane‐wave method. We found the SrAl2H2and Ca5Sn3H hydrides are metallic and Ca3SnH2is a small‐gap semiconductor. We analyzed the chemical bonding features of this series of compounds. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Titanium oxides and silicates as high‐κ dielectrics: A first‐principles investigation
Authors: Rignanese G.‐M. , Rocquefelte X. , Gonze X. , Pasquarello Alfredo 
Published: November 2004

AbstractUsing density functional theory, we investigate the structural, vibrational, and dielectric properties of titanium oxides and silicates, which have attracted considerable attention in the framework of the quest for alternative high‐κ materials. For the oxides, three crystalline phases of titanium dioxide are considered. The first two are hypothetical; they are obtained by similarity with the cubic and tetragonal structure of zirconia ZrO2 or hafnia HfO2. The third is the rutile, a crystal that occurs naturally. For the silicates, we analyze a hypothetical TiSiO4 structure constructed by analogy with crystalline ZrSiO4 and HfSiO4 (zircon and hafnon). © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
DFT description of the magnetic structure of polynuclear transition‐metal clusters: The complexes [{Cu(bpca)2(H2O)2}{Cu(NO3)2}2], (bpca = Bis(2‐pyridylcarbonyl)amine), and [Cu(DBSQ)(C2H5O)]2, (DBSQ = 3,5‐di‐tert‐butyl‐semiquinonato)
Authors: Bencini Alessandro , Totti Federico 
Published: November 2004

AbstractBroken symmetry B3LYP‐DFT calculations on three‐ and four‐spin systems, namely the complexes [{Cu(bpca)2(H2O)2}{Cu(NO3)2}2], (bpca = Bis(2‐pyridylcarbonyl)amine), 1, and [Cu(DBSQ)(C2H5O)]2, (DBSQ = 3,5‐di‐tert‐butyl‐semiquinonato), 2, have been performed. A procedure to compute the exchange coupling constants through the use of a complete set of broken symmetry determinants is suggested. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Theoretical study of neutral and cationic complexes involving phenol
Authors: Tran Fabien , Wesołowski Tomasz A. 
Published: November 2004

AbstractGeometry and interaction energy in complexes of the Ph–L type (L = Ar, N2, CO, H2O, NH3, CH4, CH3OH, CH3F) involving neutral or cationic phenol were determined using the density functional theory formalism based on the minimization of the total energy bifunctional and gradient‐dependent approximations for its exchange‐correlation and nonadditive kinetic‐energy parts. For the neutral complexes the calculated interaction energies range from 1 kcal/mol for the Ph–Ar complex to about 10 kcal/mol for Ph–NH3. The interactions are stronger if the cationic phenol is involved (up to 25 kcal/mol). It is found, except for neutral Ph–Ar, that the hydrogen‐bonded structure is more stable than the π‐bound one. Calculated interaction energies (De) correlate well with the experimental dissociation energies (D0). © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Nesidioblastosis: An Old Term and a New Understanding
Authors: Kaczirek Klaus , Niederle Bruno 
Published: November 2004

AbstractNesidioblastosis is a clinically, pathologically, and genetically heterogeneous disease. Differences between well described forms in neonates with persistent hyperinsulinemic hypoglycemia of infancy (PHHI) and rare forms in adults are described. Histopathologic criteria include hypertrophic islets occasionally showing beta cells with pleomorphic nuclei, ductuloinsular complexes, and neoformation of islets from ducts. These changes can be found as diffuse or focal forms of nesidioblastosis. Although most cases occur sporadically, several genetic defects (SUR1, Kir6.2, GCK, and GLUD1 genes) have been described in neonates. In adults a higher rate of nesidioblastosis is observed in conjunction with multiple endocrine neoplasia type 1. The disease is diagnosed biochemically by a supervised fasting test in adults and in neonates by determining the glucose requirements to maintain normoglycemia, inappropriately high insulin and c‐peptide levels, low free fatty acid and ketone body concentrations, glycemic response to glucagons, and the absence of ketonuria. If all highly selective noninvasive imaging techniques fail to identify a tumor, selective arterial calcium stimulation testing for gradient‐guided surgery in adults and percutaneous transhepatic pancreatic venous sampling in neonates should be performed. a 95% pancreatectomy is necessary in neonates with a diffuse form of nesidioblastosis, whereas focal forms can be treated by partial pancreatectomy.
Prognostic Indications for Hürthle Cell Cancer
Authors: Kushchayeva Yevgeniya , Duh Quan‐Yang , Kebebew Electron , Clark Orlo H. 
Published: November 2004

AbstractHürthle cell carcinoma (HCC) has been reported to have variable clinical behavior. The objective of this study was to determine the important prognostic factors in patients with HCC. It was a retrospective investigation of 33 patients with HCC treated in our institution from 1976 to 2002. The average age of our 33 patients with HCC was 55.2 years (range 20–82 years; 23 women, 10 men). Fifteen patients (45.5%) presented with a T2 tumor, 7 (21.2%) with a T3 tumor, and 8 (24.2%) with a T4 tumor; the tumor stage was unknown in three patients. Coexisting papillary carcinoma occurred in six patients (18%), 9% of whom presented with metastatic disease. Twelve patients (36.4%) had metastases, four of whom (12.2%) had persistent HCC, and 8 (24.2%) developed recurrent HCC (range 1–9 years). Eight of these twelve patients (66.7%) died from the HCC. The average follow‐up time was 5.5 years (range 1–16 years). Altogether, 3 of 23 women and 5 of 10 men died from their HCC (p < 0.05). Of the 22 patients with T2‐T3 tumors, 5 (22.7%) developed metastases and 1 patient died; 5 of 8 patients (62.5%) with T4 tumors developed metastases and died (p < 0.01). Patients who were treated by less than total thyroidectomy had a worse prognosis by univariate analysis (p < 0.01) but not by multivariate analysis. Survival time for patients with persistent disease was shorter than for those with recurrent disease (p < 0.05). Multivariate analysis, however, revealed no difference for extent of operation or those with persistent and recurrent disease. The cause‐specific survivals were 74% and 49% at 5 and 10 years, respectively. Disease‐free survivals were 65.0% and 40.5% at 5 and 10 years, respectively. Our findings show that gender and stage of disease influence the prognosis of patients with HCC.
Modified Radical Neck Dissection for Differentiated Thyroid Cancer: Operative Technique
Authors: Uchino Shinya , Noguchi Shiro , Yamashita Hiroyuki , Watanabe Shin 
Published: November 2004

AbstractOur standard surgical approach to patients with papillary thyroid cancer is subtotal thyroidectomy with modified radical neck dissection (MRND) on the affected side. MRND preserves the jugular vein, the sternocleidomastoid muscle, and the accessory nerve, effectively conserving function and cosmesis. Knowledge of the anatomy of the neck, precise staging, prognostic evaluation, and experience are needed for a surgeon to perform MRND. Radical neck dissection should not be performed unless the tumor invades the jugular vein and sternocleidomastoid muscle. Berry picking is not indicated for patients with thyroid cancer. The skin incision used is an extended collar incision. If lymph node metastasis is present at the upper bifurcation of the carotid artery, a modified MacFee incision is used. Taping of the carotid artery or sternocleidomastoid muscle is avoided unless the tumor invades these tissues. MRND is a safe procedure when performed by skilled, experienced surgeons.
Resection and Reconstruction of the Airway in Patients with Advanced Thyroid Cancer
Authors: Nakao Kazuyasu , Kurozumi Kazushi , Nakahara Masaaki , Kido Tetsuo 
Published: November 2004

AbstractThe prognosis of patients with differentiated thyroid cancer is relatively fair, with a 10‐year survival rate above 80%. One of the important prognostic factors is cancer invasion to the airway. For the last 25 years we have been performing combined resection of the trachea and larynx and have reported a relatively good 10‐year survival (67.7%) and improved quality of life (QOL). However, operative complications associated with the procedure, especially insufficiency of the anastomosis and bleeding from large vessels, are life‐threatening. Of 40 patients who underwent resection of the trachea, insufficiency of the anastomosis occurred in 4 and subsequent massive bleeding from carotid artery due to neck infection in 2. Tracheal resection should be carried out carefully by avoiding insufficiency. We have concluded that combined resection is a good treatment choice for survival and good QOL when performed for local control in patients with differentiated thyroid cancer.
Laparoscopic Pancreatic Surgery for Islet Cell Tumors of the Pancreas
Authors: Assalia Ahmad , Gagner Michel 
Published: November 2004

AbstractThe experience with laparoscopic pancreatic surgery (LPS) in general, and pancreatic islet cell tumors (ICTs) in particular, is still limited. Because insulinoma is the most prevalent tumor and is mostly benign, single, and curable with surgical excision, it comprises most of the cases. Our experience with 17 cases (10 insulinomas, 2 gastrinomas, 1 nesidioblastoma, 4 nonfunctioning tumors) and those recorded in the literature (93 cases) show that laparoscopic surgery for small, solitary benign islet cell tumors located in the body and tail is feasible and safe and can result in rapid postoperative recuperation and a complication rate comparable or lower than that achieved with open surgery. It duplicates the success rate seen with conventional surgery regarding intraoperative localization and cure of disease. The main morbidity continues to be the occurrence of a fistula (18%), most often after enucleation, but the clinical course is benign in most instances. Preoperative imaging studies are required for localization, and the combined use of biphasic helical computed tomography and endoscopic ultrasonography (US) seems to be cost‐effective. The use of laparoscopic US is an integral part of the laparoscopic procedure, and the information achieved is valuable for both confirming localization and decision making concerning the most appropriate surgical procedure. In cases of distal pancreatectomy, splenic salvage, preferably with preservation of splenic vessels, is feasible albeit more demanding and can be achieved in most cases.