bluuebunny/crossref_metadata_2025_split huggingface dataset:
Early detection of prostate cancer with low PSA cut‐off values leads to significant stage migration in radical prostatectomy specimens
Authors: Berger Andreas P. , Spranger Robert , Kofler Kurt , Steiner Hannes , Bartsch Georg , Horninger Wolfgang 
Published: August 2003

AbstractBACKGROUNDThe introduction of prostate‐specific antigen (PSA) contributed to a shift in tumor stage at diagnosis in patients with prostate cancer. The aim of the present study was to evaluate the effects of PSA screening with low PSA cut‐off values on mean total and percent‐free PSA levels in patients with prostate cancers at the time of diagnosis as well as on pathologic stage and mean Gleason scores in positive biopsies and radical prostatectomy specimens.METHODSData of 875 patients who were diagnosed with prostate cancers between 1996 and 2001 were analyzed. Patients were stratified into six groups according to the year of biopsy. Annual changes in total and percent‐free PSA values, in Gleason scores of biopsies and radical prostatectomy specimens, and in pathologic stages of radical prostatectomy specimens were assessed.RESULTSMean PSA of patients diagnosed with prostate cancer decreased from 13.11 ng/ml (percent‐free PSA: 11.89%) in 1996 to 7.33 ng/ml (percent‐free PSA: 12.58%) in 2001 (P < 0.05). The percentage of organ‐confined prostatectomy specimens increased from 64.3% in 1996 to 81.5% in 2001 (P < 0.05). However, mean Gleason scores increased from 5.23 to 6.33 over the 6 years (P < 0.05). The percentage of patients with biopsy‐proven prostate cancers and PSA values below 4 ng/ml increased from 14.0% in 1996 to 39.2% in 2001. In the group with PSA values below 4 ng/ml organ‐confined cancers were found in 80.0–95.2% of patients.CONCLUSIONSPSAg screening with low cut‐off levels has led to a significant reduction of mean baseline PSA levels in prostate cancer patients and to a significant increase in the percentage of organ‐confined radical prostatectomy specimens, whereas mean Gleason scores have remained relatively constant. Prostate 57: 93–98, 2003. © 2003 Wiley‐Liss, Inc.
TR2 orphan receptor functions as negative modulator for androgen receptor in prostate cancer cells PC‐3
Authors: Mu Xiaomin , Chang Chawnshang 
Published: August 2003

AbstractBACKGROUNDBoth androgen receptor (AR) and orphan receptor TR2 (TR2) belong to the steroid nuclear receptor superfamily and are expressed in prostate cancer tissue and cell lines. AR has been known to be involved in prostate proliferation and prostate cancer progression. AR binds to androgen response elements and regulates target gene expression via a mechanism involving coregulators. However, the function of TR2 in prostate and prostate cancer and the relationship between TR2 and AR in the prostate cancer is unclear.METHODSTransient transfection and CAT reporter gene assays were employed to assess AR‐mediated transactivation. The expression level of prostate specific antigen (PSA) was measured by Northern blot analysis. The interaction between AR and TR2 was assessed by glutathione‐S‐transferase (GST) pull‐down assay and mammalian two‐hybrid system assay.RESULTSOrphan nuclear receptor TR2 suppressed androgen‐mediated transactivation in prostate cancer PC‐3 cells, and over‐expression of TR2 suppressed PSA expression. The suppression of AR mediated transactivation by TR2 is not due to competition for the limited coregulator availability by these two receptors, but possibly through the interaction between TR2 and AR nuclear receptors.CONCLUSIONSTR2 may function as a negative modulator to suppress AR function in prostate cancer. Further studies on how to control TR2 function may result in the ability to modulate AR function in prostate cancer. Prostate 57: 129–133, 2003. © 2003 Wiley‐Liss, Inc.
Effect of carbohydrate moieties on the folate hydrolysis activity of the prostate specific membrane antigen
Authors: Ghosh Arundhati , Heston Warren D.W. 
Published: August 2003

AbstractBACKGROUNDProstate specific membrane antigen or PSMA has been recognized as one of the important cellular markers for prostate cancer, the expression of which is enhanced many fold in prostate cancer and other tumor neovasculature. PSMA is a type II membrane glycoprotein with a short cytoplasmic N‐terminal region, a transmembrane domain, and a 701 amino acid extracellular portion with 10 potential N‐linked glycosylation sites. PSMA is a folate hydrolase, which cleaves terminal glutamates from poly‐ and gamma‐glutamated folates; and NAALADase, which hydrolyses alpha‐glutamate‐linked dipeptide, N‐acetyl‐aspartyl‐glutamate (NAAG) and is a glutamate carboxypeptidase.METHODSIn our study we have used various enzymes or site directed mutagenesis to remove sugar molecules from PSMA protein and studied its folate hydrolase function. We have performed a biochemical characterization of N‐linked glycosylation of the various mutant proteins.RESULTSPSMA protein expressed in different prostate cancer cell lines is differentially glycosylated. Removal of sugar residues either enzymatically or by mutagenesis abolishes the enzyme activity of PSMA protein completely.CONCLUSIONN‐linked carbohydrate structures are important for the folate hydrolase function of the protein. Removal of sugars partially or completely causes PSMA to be enzymatically inactive, improperly folded, resulting in increased rate of degradation. Prostate 57: 140–151, 2003. © 2003 Wiley‐Liss, Inc.
Electronic properties of the metallic zigzag single‐walled carbon nanotube ropes
Authors: Chen Jiangwei , Wan Xiangang , Dong Jinming 
Published: August 2003

AbstractUsing Slater–Koster tight‐binding calculations, we found that, due to the coexistence of the π–σ electron hybridization and the inter‐tube interactions, the electronic properties of the rope formed by small‐radius metallic zigzag single‐walled carbon nanotubes (SWNTs) have some unique characters: for the rope formed by (9,0) SWNTs, its electronic properties near the Fermi level are mainly affected by the π–σ electron hybridization; and for the rope formed by (12,0) SWNTs, both factors affect the electronic properties significantly. With increasing SWNT radius, the effect of the π–σ electron hybridization decreases quickly. Finally, boundary effects of the finite sized rope have also been investigated, which reduce the pseudogap generally.
Temperature and pressure dependence of phonon frequencies in GeS2, GeSe2, and SnGeS3
Authors: Jakšić Z. M. 
Published: August 2003

AbstractThe Raman spectra of β‐GeS2, β‐GeSe2, and SnGeS3 crystals have been investigated as a function of temperature (18 to 300 K) at ambient pressure, and as a function of hydrostatic pressure, up to 4.9 GPa, at room temperature. Our aim was to separate the phonon–excitation–driven (“explicit”) and the thermal–expansion–driven (“implicit”) contribution to the total observed temperature coefficient (dν/dT). β‐GeS2 exhibits a regular behavior: when its “external” modes are excited the coefficient is dominated by the implicit effect, while in the case of excited “internal” modes by the explicit effect. In the cases of β‐GeSe2 and SnGeS3 a clear separation into external and internal modes was not possible, as in the case of β‐GeS2. For β‐GeSe2 the explicit–implicit contributions to (dν/dT) were determined for five “internal” modes. For most of the modes in SnGeS3 “explicit” and “implicit” contributions to (dν/dT) are of comparable magnitude.
Classical limit for electronic disordered systems: spectral tails and thermodynamical properties
Authors: Flores J. C. 
Published: August 2003

AbstractWe consider the classical limit for the density of states of an electron in a disordered one‐dimensional chain. The low energy tail of the density of states is analytically studied and we evaluate the thermodynamical properties of this system. For the Boltzmann distribution the heat capacity grows when disorder increases. On the other hand in the quantum case, corresponding to the Fermi‐Dirac statistic, the heat capacity diminishes when disorder increases.
Correlation effects and Pekar bipolaron (arbitrary electron–phonon interaction)
Authors: Kashirina N. I. , Lakhno V. D. , Sychyov V. V. 
Published: August 2003

AbstractThe Buimistrov–Pekar method of canonical transformation was used to calculate the energies of the lowest singlet and triplet terms of bipolarons in crystals with ionic binding. An arbitrary electron–phonon interaction described by the Fröhlich Hamiltonian was considered. It was shown that, in the whole parametric range of electron–phonon interaction, the value of the free bipolaron ground state energy obtained by the Buimistrov–Pekar method is lower than all those found by Adamowski and Bednarek in the framework of direct variational approaches, and only slightly exceeds (relative error <0.3%) those obtained by Verbist, Peeters, and Devreese by integration over trajectories for α ≤ 7. The calculations have shown that any metastable triplet states corresponding to the lowest triplet term of a bipolaron are absent for all the parameters of the electron–phonon interaction, the results being in complete analogy with Hill's theorem about the absence of any bound excited states for an H− ion. Study of a wave function of more general form has demonstrated that a two‐center bipolaron is energetically less advantageous than a one‐center one for all the parameters of the electron–phonon interaction. Control calculations performed with the system of functions used in this paper have yielded 1.173 a.u. for the hydrogen molecule energy, which is in good agreement with the experimental value.
Optical band gap in relation to the average coordination number in Ge—S—Bi thin films
Authors: Saffarini G. , Schmitt H. , Shanak H. , Nowoczin J. , Müller J. 
Published: August 2003

AbstractChalcogenide glasses belonging to the GexS94 − xBi6 system (14 ≤ x ≤ 28.33 at%) have been prepared from high purity constituent elements. Thin films of the same materials have been deposited by vacuum thermal evaporation. Optical absorbance measurements have been performed on the as‐deposited films. The allowed optical transition is found to be indirect and the corresponding optical gaps, Eg, are determined. The variation of Eg with the average coordination number, 〈r〉, is also investigated. The observed Eg − 〈r〉 dependence is discussed on the basis of the chemical bonding between the constituents and the rigidity percolation threshold behavior of the network.
Vibrational dynamics at a surface atomic well
Authors: Tigrine R. , Khater A. , Rafil O. , Belhadi M. , Hardy J. 
Published: August 2003

AbstractWe investigate the dynamical phenomena at the inhomogeneous boundary of an extended atomic well in crystalline solid surfaces. The surfaces are considered as a semi‐infinite slab of two coupled atomic layers, and the well as a single atomic chain. This simplified geometric configuration models an atomic well in a surface. The breakdown of translation symmetry in the direction parallel to the surface and normal to the extended well gives rise to localized vibrational modes in its neighborhood. The matching method is used in this study, it may be applied to analyze both the vibrational and the scattering dynamical phenomena for surface inhomogeneities. Characteristic vibrational Green functions and spectral densities are calculated for this system, in particular for the atomic sites which constitute a representative ensemble for the well. The variations of these spectra are presented as a function of the variation of the elastic parameters of the well. This illustrates the variation of the spectra for the softening and the hardening situations of the surface atomic well. The calculated spectra could yield, in comparison with experimental results to come, useful information concerning the elastic parameters of such a surface atomic well.
Cyclotron resonance on anisotropic energy surfaces analyzed for a magnetic field tilted with respect to the crystallographic axes
Authors: Olszewski S. , Baszczak M. 
Published: August 2003

AbstractParameters characterizing the electron motion performed in the cyclotron resonance effect, especially the electron gyration frequency, are calculated as functions of the angle with which the direction of a constant magnetic field is tilted with respect to the direction of one of the crystallographic axes. Tightly bound s electrons forming bands of states in simple cubic and body‐centered cubic lattices have been chosen for the calculations as examples for the electron and crystal. In each lattice case an equation for the electron motion performed along a closed anisotropic surface of constant energy has been derived and solved on the basis of a semi‐classical theory.
Theory and simulation of dopant implantation and diffusion in SiGe
Authors: Liu Chun‐Li , Orlowski Marius , Thean Aaron , Beardmore Keith , Barr Alex , White Ted , Nguyen Bich‐Yen , Rueda Hernan , Liu Xiang‐Yang 
Published: August 2003

AbstractStrained Si‐based technology has imposed a new challenge for understanding dopant implantation and diffusion in SiGe that is often used as the buffer layer for a strained Si cap layer. In this work, we describe our latest modeling effort investigating the difference in dopant implantation and diffusion between Si and SiGe. A lattice expansion theory was developed to account for the volume change due to Ge in Si and its effect on defect formation enthalpy. The theory predicts that As diffusion in SiGe is enhanced by a factor of ∼10, P diffusion by a factor of ∼2, and B diffusion is retarded by a factor of ∼6, when compared to bulk Si. These predictions are consistent with experiment. Dopant profiles for As, P, and B were simulatedusing process simulators FLOOPS and DIOS. The simulated profiles are in good agreement with experiment. Dopant implantation was simulated using REED‐MD. The results showed a noticeable difference in peak and tail positions SiGe compared to Si. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthesis dynamics of passivated silicon nanoclusters
Authors: Draeger Erik W. , Grossman Jeffrey C. , Williamson Andrew J. , Galli Giulia 
Published: August 2003

AbstractThe effect of preparation conditions on the structural and optical properties of silicon nanoparticles is investigated using first‐principles molecular dynamics and quantum Monte Carlo techniques. We find that high‐temperature synthesis processes can produce kinetically‐limited nanostructures with different core structures than bulk‐derived crystalline clusters. These nanoparticles have optical gaps in better agreement with experimental measurements than crystalline clusters of the same size. The type of core structure that forms from a given synthesis process may depend on the passivation mechanism and time scale. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electric field effects on the octanedithiol wire
Authors: Li Jun , Tomfohr John K. , Sankey Otto F. 
Published: August 2003

AbstractWe theoretically study the electric field profile and the voltage profile across a model molecule in a metal‐molecule‐metal junction under bias. The model system is octanedithiol (S–(CH2)8–S) sandwiched between two gold electrodes (Au[111]). We use a simple, but approximate, method to investigate the voltage profile across the molecule and the change of electronic states under a given bias. The key simplification is to artificially shift the two metal (Au) Hamiltonians relative to each other within a closed system to simulate the external bias of an open system. The Hamiltonian of the closed system is calculated within density functional theory using local orbitals and the electronic structure of the entire system is determined self‐consistently. In the final step after charge transfer has taken place, we remove the artificial metal Hamiltonian shifts to reveal an oppositely biased system with a built‐in electric field across the molecule. The electric field effects on the electronic structure of the molecule are analyzed by tracking the on‐site orbital energies (diagonal Hamiltonian matrix elements) and the projected electronic density of states onto atoms along the molecular wire. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Short‐wavelength charge oscillations in semiconducting carbon nanotubes
Authors: Léonard François 
Published: August 2003

AbstractSelf‐consistent tight‐binding calculations for Carbon Nanotube devices have shown large oscillations of the charge from atom to atom. To explain this effect, we present a linear response theory for semiconducting carbon nanotubes subject to an external electrostatic potential perturbation. Within tight‐binding theory, it is demonstrated that the large charge oscillations originate from the polyatomic nature of the unit cell. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Rattling guest atoms in Si, Ge, and Sn‐based type‐II clathrate materials
Authors: Myles Charles W. , Dong Jianjun , Sankey Otto F. 
Published: August 2003

AbstractWe have studied the vibrational properties of some of the compounds based on the Type II silicon, germanium, and tin‐based clathrate materials using LDA electronic structure methods. The lattices in these framework materials have open cages which can contain weakly bound guest impurities, and these guests produce local (“rattling”) vibrational modes. Such modes may scatter the extended, heat carrying acoustic vibrational modes of the framework, potentially reducing the thermal conductivity. We present results for the vibrational spectra of the Type II clathrate compounds Na16Cs8Si136, Na16Cs8Ge136, and Cs24Sn136. We discuss trends in the vibrational spectra of the framework host material and of the localized, rattling frequencies of the guest modes as the host changes from Si to Ge to Sn. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Reaction enthalpies as selection criteria for tribological coatings
Authors: Ooi N. , Adams James B. , Singisetti Uttam 
Published: August 2003

AbstractA wide range of coatings are used for a variety of applications. Selection criteria for these coatings include coating‐substrate adhesion, hardness, melting temperature, coefficient of thermal expansion mismatch, corrosion resistance, and cost. A factor often ignored is the possibility of reaction between the coating and the other surface which it contacts during use. This is especially important when frictional forces produce enough heat to locally melt asperities or even cause friction welding, as that heat will enhance the likelihood of chemical reactions at the interface. One aspect of this is to consider the reaction enthalpies between coatings and the surfaces they contact during operation. We explore the use of reaction enthalpies between coatings and opposing surfaces as a criteria for selecting coatings. Simple thermodynamic calculations are presented for several couples of coating – opposing surfaces. Conclusions are drawn about the relevance based on experimental evidence. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Non‐equilibrium Green function implementation of boundary conditions for full band simulations of substrate‐nanowire structures
Authors: Rivas Cristian , Lake Roger 
Published: August 2003

AbstractThe density of states of a nanowire exhibits peaks at energies in which the individual transverse modes begin to propagate. Under ideal conditions these modes are eigenstates solely determined by the cross sectional size and shape of the nanowire. However, for realistic nanowires, which are grown on semiconductor substrates, the density of states of the subsrate‐nanowire structure is dependent on the distance from the nanowire endpoints. Near the substrate, the density of states is is nonzero far below the energy corresponding to the first eigenstate of the ideal nanowire. This initial increase in the density of states occurs at energies near the conduction and valence band edges of the semiconductor substrate on which the nanowire is grown. Away from the substrate, the density of states begins to acquire ideal nanowire characteristics. In the present work this effect is captured by imposing boundary conditions, with properties of bulk material, at the nanowire base. The calculations utilize a first neighbor sp3s*d5 orbital basis within the non‐equilibrium Green function formalism. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Difficulties of the microscopic theory of leakage current through ultra‐thin oxide barriers: point defects
Authors: Fonseca Leonardo R. C. , Demkov Alexander A. , Knizhnik Andrey 
Published: August 2003

AbstractWe use a combination of first‐principles density functional theory and non‐perturbative scattering theory to investigate the effect of point defects on the hole leakage current through ultra thin oxide films. In particular, we consider O vacancies and B interstitial in monoclinic HfO2; five different defects are considered: (1) O vacancy at a three‐ and (2) a four‐coordinated O site located in the HfO2 region, (3) O vacancy along a Hf–O–Si bond and (4) along a Si–O–Si bond at the Si/HfO2 interface, and (5) an interstitial Batom in the HfO2 region. We find that the neutral bulk vacancies and an interface vacancy along theSi–O–Si bond have little impact on the leakage current. On the contrary, an interface vacancy along the Hf–O–Si bridge and an interstitial B atom in the HfO2 region introduce states in the Si band gap and in the region just below the Si valence band edge thus strongly enhancing the leakage current at a low bias. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Quality Improvement from the Viewpoint of Statistical Method
Authors: De Mast Jeroen 
Published: August 2003

AbstractWith the purpose of guiding professionals in conducting improvement projects in industry, several quality improvement strategies have been proposed which strongly rely on statistical methods. Examples are the Six Sigma programme, the Shainin System and Taguchi's methods. This paper seeks to make a rational reconstruction of these types of improvement strategies, which results in a methodological framework.The paper gives a demarcation of the subject of study and proposes a reconstruction research approach. Thereupon, the elements of the methodological framework are listed and briefly discussed. Finally, the effectiveness of the framework is illustrated by showing to what extent it reconstructs Six Sigma's Breakthrough Cookbook. Copyright © 2003 John Wiley & Sons, Ltd.
The Use of Observational Data to Implement an Optimal Experimental Design
Authors: Berni Rossella 
Published: August 2003

AbstractThis paper is focused on observational data and on the use of large data sets to implement an experimental design without additional runs, for an efficient use of these data. More specifically, the proposed procedure is based on several steps, aimed at avoiding some problems, such as lack of randomization and efficiency, obtaining a final experimental design that can be assumed as optimal from the point of view of a sequential optimality. Copyright © 2003 John Wiley & Sons, Ltd.
Robust Design Methodology: Status in the Swedish Manufacturing Industry
Authors: Gremyr Ida , Arvidsson Martin , Johansson Per 
Published: August 2003

AbstractWhile robust design methodology is a fairly common subject in the literature on quality and statistics, this paper shows that only 17% of Swedish manufacturing companies apply robust design methodology. The low level of use of robust design methodology is surprising since a majority of the companies think it is important to minimize performance variation. However, although knowledge and use of robust design methodology is poor, methods suitable in robust design methodology are often used. For example, 53% of the companies use design of experiments to some extent. The data presented in this paper were collected in a telephone survey of 105 companies in the Swedish manufacturing industry; the response rate was 83%. The sample was stratified with respect to company size, and it is shown that robust design methodology and related methods are used to a greater extent in large companies than in small and medium‐sized ones. Copyright © 2003 John Wiley & Sons, Ltd.