bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inhibition of SULT2B1b expression alters effects of 3β‐hydroxysteroids on cell proliferation and steroid hormone receptor expression in human LNCaP prostate cancer cells
Authors: He Dongning , Falany Charles N. 
Published: July 2007

AbstractBACKGROUNDSulfation is an important steroid inactivation in human tissues. Sulfotransferase (SULT) 2B1b selectively conjugates 3β‐hydroxysteroids and is expressed in epithelial cells of normal and cancerous prostate tissues. Dehydroepiandrosterone (DHEA) and Δ5‐androstenediol (Δ5‐Adiol) sulfation prevents their conversion to more potent androgens and estrogens in tissues although both compounds may also be biologically active.METHODSSULT2B1b expression and activity were inhibited >85% in human LNCaP prostate adenocarcinoma cells using short interference RNA (siRNA). The effects of treating control and SULT2B1b‐deficient LNCaP cells with DHEA, Δ5‐Adiol, and 5α‐androstane‐3β‐17β‐diol (Anstane‐diol) on cellular proliferation, estrogen receptors (ERs), androgen receptor (AR), and prostate specific antigen protein levels were examined.RESULTSPhysiological concentrations of DHEA and Δ5‐Adiol increased proliferation of control cells and the proliferative effects were significantly increased in SULT2B1b‐siRNA cells. DHEA, but not Δ5‐Adiol increased AR levels at concentrations ≥1,000 nM in SULT2B1b‐siRNA cells but not in control LNCaP cells. ER‐α levels were not affected with any of the compounds tested. Physiological concentrations of DHEA and Δ5‐A‐diol decreased ER‐β levels in control cells and had significantly greater effects in SULT2B1b‐siRNA cells. In contrast, Anstane‐diol had no effect on AR or ER‐α levels but induced more elevation of ER‐β levels in SULT2B1b‐siRNA cells at concentrations ≥1,000 nM.CONCLUSIONSSULT2B1b is involved in regulating prostate cell responsiveness to DHEA and Δ5‐Adiol. Inhibition of SULT2B1b increased cell proliferation and ER‐β repression after treatment with physiological levels of DHEA and Δ5‐Adiol indicating that SULT2B1b has an inhibitory effect on DHEA and Δ5‐Adiol activity. Prostate 67: 1318–1329, 2007. © 2007 Wiley‐Liss, Inc.
Development of an androgen‐deprivation induced and androgen suppressed human prostate cancer cell line
Authors: Lee Soo Ok , Dutt Smitha S. , Nadiminty Nagalakshmi , Pinder Elaine , Liao Hongtao , Gao Allen C. 
Published: July 2007

AbstractBACKGROUNDEmergence of recurrent cells during androgen‐deprivation therapy and intermittent androgen suppression therapy suggest that a subset of prostate cancer cells survive and proliferate in the androgen deprivation condition. Some of the recurrent cells that emerge during the androgen‐deprivation therapy and intermittent androgen suppression therapy could be suppressed by replacement of androgen. In an attempt to recapitulate the clinical phenomenon, we developed an androgen‐deprivation induced and androgen suppressed human prostate cancer cell line.METHODSLNCS, an androgen‐deprivation induced and androgen suppressed human prostate cancer cell line, was generated from an androgen‐sensitive LNCaP cells cultured in PRMI‐1640 media containing charcoal‐stripped FBS for a prolong period for more than a year. The responsiveness to androgen in vitro and in vivo was examined. The characteristics of this subline including activation of signaling pathways were investigated.RESULTSLNCS, an androgen‐deprivation induced and androgen suppressed human prostate cancer cell line, was developed. LNCS cells express considerably lower levels of androgen receptor than LNCaP cells and grow vigorously in androgen deprived condition in vitro, and develop tumors in castrated male mice in vivo. Addition of androgen inhibits cell growth in vitro and tumor growth in vivo. LNCS cells are more resistant to etoposide, a typical apoptotic inducing agent. Although AR signaling is less active in LNCS cells, Stat3 is constitutively activated. Down regulation of Stat3 activation inhibits LNCS cell growth in vitro.CONCLUSIONSWe have developed an androgen‐deprivation induced and androgen suppressed human prostate cancer cell line. This cell line is a valuable tool to study molecular mechanisms of the progression of androgen refractory prostate cancer and intermittent androgen suppression therapy. Prostate 67: 1293–1300, 2007. © 2007 Wiley‐Liss, Inc.
Change of expression levels of alpha1‐adrenoceptor subtypes by administration of alpha1d‐adrenoceptor‐subtype‐selective antagonist naftopidil in benign prostate hyperplasia patients
Authors: Kojima Yoshiyuki , Sasaki Shoichi , Shinoura Hitomi , Hayase Masa , Kubota Yasue , Hayashi Yutaro , Tsujimoto Gozoh , Kohri Kenjiro 
Published: July 2007

AbstractBACKGROUNDWe examined whether the change of alpha1‐adrenoceptor (α1‐AR) subtype expression levels in the prostate occurred by administration of the α1d‐AR‐subtype‐selective antagonist naftopidil to benign prostate hyperplasia (BPH) patients, and discussed the possible alternation of its effectiveness by the chronic administration of α1‐AR antagonists.METHODSFifteen patients with untreated BPH aged 58–76 (mean age, 68.2 ± 7.4 years) underwent prostate biopsy from the transition zone before and after 50 mg naftopidil administration daily for 12 weeks. Taqman quantitative reverse transcription polymerase chain reaction was performed using these biopsy specimens to estimate the expression level of each α1‐AR subtype. Comparison was made of the expression level of α1‐AR subtypes before and after naftopidil administration. We also examined the correlation between the change of α1‐AR subtype expression levels and the short‐term efficacy of naftopidil.RESULTSNaftopidil administration for 12 weeks down‐regulated the expression of α1a‐AR and α1b‐AR mRNA and up‐regulated the expression of α1d‐AR mRNA without a change in the total α1‐AR mRNA expression level. There was no correlation between the change of α1‐AR subtype expression levels and the short‐term efficacy of naftopidil for BPH patients.CONCLUSIONThe change of α1d‐AR expression level may be regarded as a compensatory adaptation to chronic α1d‐AR antagonist naftopidil administration. This may mean that long‐term use of the same α1‐AR antagonist for BPH patients induces therapeutic tolerance. Prostate 67: 1285–1292, 2007. © 2007 Wiley‐Liss, Inc.
Current optimum management of dyspepsia and ulcers
Authors: Anderson Simon , Wilkinson Mark 
Published: July 2007

AbstractSeveral protocols and management guide lines for dyspepsia have been produced in recent years. This Drug review outlines the current recommendations on the investiga tion and treatment of dyspepsia, GORD and peptic ulceration, followed by sources of further information and the Datafile. Copyright © 2007 Wiley Interface Ltd
Parameters of band structure in surface layers of zero‐gap semiconductors (CdHg)Te
Authors: Yafyasov A. , Bogevolnov V. , Perepelkin A. 
Published: July 2007

AbstractThe field‐effect method in electrolytes is used for finding the band structure parameters in surface layers of zero‐gap semiconductors (ZGS) (CdHg)Te. It is found that the conduction band both in surface layers and in the volume of ZGS (CdHg)Te obeys the ultrarelativistic dispersion relation. The electron effective mass in surface layers of ZGS (CdHg)Te is close to the electron effective mass in the volume of ZGS (CdHg)Te. It is stated that the heavy‐hole valence band both in surface layers and in the volume of ZGS (CdHg)Te has a non‐parabolic dispersion relation, and that the heavy‐hole effective mass is less than 0.5m0 and depends on the composition of (CdHg)Te. It is found that the position of the Fermi level in ZGS (CdHg)Te is described in the model of zero‐gap semiconductors with fluctuating potential. The “step” structure in the dependences of the differential capacitance of the space‐charge layer in ZGS (CdHg)Te on temperature at fixed values of the surface potential is observed experimentally for the first time.
The properties of surface polarons in polar crystals
Authors: Xiao Jing‐Lin , Xing Tong‐Hai , Sun Bao‐Quan , Xiao Wei 
Published: July 2007

AbstractSome properties of a surface polaron in polar crystals are studied. The effective Hamiltonian of the surface polaron is derived using a perturbation method. If we consider the interaction between phonons of different wave vectors in the recoil process, the influence on the effective Hamiltonian, effective potential, and effective mass are discussed. Numerical calculations for GaAs, ZnS, and AgBr crystals, as examples, are performed.
Temperature dependence of the excitonic transitions in GaAsGaAlAs superlattices under a weak electric field
Authors: Depeyrot J. , Tronc P. , Umdenstock E. , Palmier J. F. , Etienne B. 
Published: July 2007

AbstractThe temperature variations (between 9 and 80 K) of the ratio ϱ = I−1/I0 of the intensities of the −1 and 0 peaks of the Wannier‐Stark ladder in a GaAsGa0.65Al0.35 As superlattice under an electric field are interpreted. The model is based on the thermal equilibrium between the two populations of excitons. The filling rate of every excitonic levels is given by the Maxwell‐Boltzmann distribution function. A discrepancy appears at low temperatures (T < 50 K); the excitons are trapped into the direct state rather than in the crossed one, showing that the equilibrium statistics are not respected.
On the theory of shallow acceptor states in real semiconductors
Authors: Zubkova S. M. , Filin V. G. , Smelyanskaya E. V. , Tolpygo K. B. 
Published: July 2007

AbstractShallow acceptor states in crystals with diamond and sphalerite type structures are investigated by analytical and numerical methods, proposed by the authors for an exciton problem previously. The complicated valence band structure and the chemical nature of the impurity are taken into account. The obtained results for B and Al in Ge, Si, Zn Te, SiC, and GaAs are in good agreement with available experimental data and theoretical calculations of other works.
Antiferromagnetic interaction between two easy‐plane ferromagnetic heisenberg chains
Authors: Diaz V. , Gutiérrez G. , Ferrer R. 
Published: July 2007

AbstractNonlinear magnetic excitations in the Heisenberg magnetic system CsNiF3, when an antiferromagnetic interchain interaction is present between two neighboring easy‐plane ferromagnetic chains, are studied. Using a two‐lattice model and defining coherent states on each site for the two chains the discrete coupled equation for the averages of the spin components are given. In the easy‐plane limit it is found that three kinds of static magnetic excitations can exist, depending on the value of the antiferromagnetic interchain exchange interaction J2. The inclusion of this antiferromagnetic interchain interaction makes the problem of the nonlinear magnetic excitations appear in a new light.
Effective‐field renormalization‐group approach for quenched site‐dilute ising models
Authors: Bobák A. , Jaščur M. , Mockovčiak S. 
Published: July 2007

AbstractThe quenched site‐dilute Ising model in two and three dimensions is studied by employing the effective‐field renormalization‐group method. The concentration dependence of the critical temperature and values of the critical concentration are obtained and compared to other different methods. Quite good results for a honeycomb lattice are achieved even by considering the smallest possible clusters. In particular, it is shown that the present formalism is able to distinguish between lattices of the same coordination number but of different dimensions.
Mercury Diffusion in Cadmium Telluride
Authors: Sadaiyandi K. , Karthikeyan P. , Ramachandran K. 
Published: July 2007

AbstractTheoretical calculations are carried out for the slow diffusion of mercury in cadmium telluride. Single vacancy, single interstitial, and divacancy mechanisms are tried. The results suggest that the most possible mechanism for Hg diffusion in CdTe is the single vacancy mechanism.
Porous Silicon Photoluminescence Enhancement and Saturation Resulting from Thermal Annealing in Nitrogen Gas
Authors: Chen Zhiliang , Bosman Gijs 
Published: July 2007

AbstractThe results of thermal annealing at 800 and 900 °C of porous silicon samples in N2 ambient conditions are discussed as a function of annealing time, annealing procedure, and sample preparation. The results show that N2 annealing plays an important role in surface passivation and nanostructure feature size shrinkage and may result in photoluminescence (PL) intensity enhancement and saturation with annealing time under appropriate conditions. The experimental results strongly support the quantum confinement model for PL in porous silicon.
Bulk and Interface Polarons in Quantum Wires and Dots
Authors: Klimin S. N. , Pokatilov E. P. , Fomin V. M. 
Published: July 2007

AbstractThe vibrational modes of inertial polarization in the multilayer wire‐like and dot‐like structures are determined. The bulk confinement modes and the interface ones are separated exactly by a unitary transformation, various additional boundary conditions for the inertial polarization vector being taken into account. The Hamiltonian of the electron‐phonon interaction is deduced. The polaron ground state energy as well as the effective mass in the cylindrical quantum wire and polaronic shift of electron energy levels in the spherical quantum dot are calculated.
Electrodynamic Properties of an Edged High‐Temperature Superconducting Film
Authors: Saif A. G. , El‐Sabagh M. A. 
Published: July 2007

AbstractThe structure of the surface barrier and the effect of a transport current on the annihilation of this barrier are investigated for a high‐temperature type‐II superconducting film of arbitrary thickness. It is found that the surface barrier depends on the external field strength, the value of the transport current flowing through the sample, and the orientation of the external field. The results obtained are found in agreement with some previous ones.
Photoluminescence of Anodically Oxidized Porous Silicon
Authors: Filippov V. V. , Pershukevich P. P. , Bondarenko V. P. , Dorofeev A. M. 
Published: July 2007

AbstractA photoluminescence (PL) study is carried out on porous silicon (PS) layers of 50 to 60% porosity which are anodically oxidized in ethylenglycol NH4NO3 electrolyte. Such oxidation is found to make the PL intensity stronger and the peak wavelength shorter. The emission of partially linearly polarized light is observed for PS samples under linearly polarized light excitation. Transmission IR and reflectance spectra are recorded to characterize porous silicon. As a result, a strong shift of the absorption band edge and high silicon oxide content are found in PS sampl. This shift is supposed to be due to the quantum confinement mechanism, but the features of PL speak in favour of the important role of oxide in the light emission from PS. In particular, the polarization of the emitted light can be due to the oxide‐induced elastic strains.
Aggregation of Lead Ions Doped in CsBr Crystal
Authors: Asada H. 
Published: July 2007

AbstractThe absorption spectrum of a CsBr : Pb2+ crystal shows remarkable isothermal changes. In the temperature range near 80 °C, the absorption constants of most of the component bands decay with time, while the 316 nm band grows. The change is caused by second‐order kinetics. Reaction velocities classify the bands into two groups, the defects responsible for the spectrum consist of two types of defects including I–V dipoles.
Electron–Phonon Interaction Influence on Electron and Phonon Excitations in Amorphous Metals
Authors: Vakarchuk I. O. , Myhal V. M. , Tkachuk V. M. 
Published: July 2007

AbstractThe influence of electron‐phonon interaction on electron and phonon excitations in amorphous metals is examined. The equation for the gap in the electron spectrum for the transition to the superconducting state is obtained. The renormalization of the energy spectrum and damping of electron and phonon excitations due to electron‐phonon interaction is considered.
Phonons in Ni31Dy69 Glass
Authors: Pratap A. , Bhandari D. , Saxena N. S. , Saksena M. P. 
Published: July 2007

AbstractThe effective interatomic potential in Ni31Dy69 glass is obtained with the experimental structure factor S(Q). This potential is compared with those computed using Percus‐Yevick (PY) and hypernetted chain (HNC) approximations. A theory of phonons in amorphous solids is employed to compute the eigenfrequencies of the longitudinal and transverse phonon modes with these diffcrcnt potentials and the results are compared with each other. The elastic and thermodynamic properties of this glass are also studied using the longitudinal and transverse sound velocities estimated from the slope of the long‐wavelength limit of the dispersion relations.
Correlation between the Ionicity Character and the Charge Density in Semiconductors
Authors: Zaoui A. , Ferhat M. , Khelifa B. , Dufour J. P. , Aourag H. 
Published: July 2007

AbstractUsing the electronic charge densities obtained by the empirical pseudopotential method for tetrahedrally bonded semiconductors, an ionicity scale is established that is in good agreement with the Phillips ionicity scale.
Theoretical X‐ray Emission Study of High‐ Tc Superconductor YBa2Cu3O7 Thin Films
Authors: Kurganskii S. I. , Kharchenko M. A. , Dubrovskii O. I. , Bugakov A. M. , Domashevskaya E. P. 
Published: July 2007

AbstractThe energy spectrum of YBa2Cu3O7 thin films is investigated by the film linearized augmented plane wave method (LAPW). On the basis of the results of the energy band structure calculation, theoretical calculations of X‐ray emission spectra are performed. The calculated spectra are compared with the results of other calculations and experimental researches. The reason of the observed systematic discrepancies in the fine structure is analysed. The obtained spectra confirm the resonance character of the interaction of copper d‐states with the nearest oxygen p‐states.
Study of the Critical Behaviour for the S = 5/2 Transverse Ising Model in a Random Field
Authors: Song W. J. , Yang C. Z. 
Published: July 2007

AbstractWith the mean‐field renormalization group theory (MFRG) and the discretized path‐integral representation (DPIR), a spin S = 5/2 transverse Ising model in a random field (RFTIM) is studied. The phase diagram and the other critical properties are investigated.
Experimental and Theoretical Investigation of Spin‐Hamiltonian Parameters for the Low Symmetry Fe3+ Centre in LiNbO3
Authors: Yeom T. H. , Chang Y. M. , Choh S. H. , Rudowicz C. 
Published: July 2007

AbstractX‐band EPR spectra of Fe3+ in LiNbO3 single crystals at room temperature are analyzed with a spin‐Hamiltonian of C3 symmetry. First the zero‐field splitting (ZFS) parameters b, b, b, and b−34 are calculated using the superposition model (SPM). The SPM‐ZFS results for Fe3+ at the Nb site agree better with the experimental ones than those for Fe3+ at the Li site. Next the crystal field (CF) parameters are predicted using SPM and two sets of available structural data for LiNbO3. Diagonalization of the full Hamiltonian, including the CF Hamiltonian, within the whole 3d5 configuration yields the ZF splittings for Fe3+ centres. The ZF splittings obtained from the theoretical SPM‐CF calculations for Fe3+ at the Nb site agree better with the experimental EPR data than those for Fe3+ at the Li site. The present results indicate that the observed EPR spectra of Fe3+ : LiNbO3 can be attributed to Fe3+ ions at the Nb sites.
Quantum Boltzmann Transport Equation in the Presence of Interactions; Application to the 2D Hall Effect
Authors: van Vliet C. M. , Samson Th. 
Published: July 2007

AbstractThe quantum Boltzmann equation (QBE), derived in previous papers, is extended to systems with strong interparticle interactions. In particular, the non‐diagonal hierarchy of kinetic equations for [ℒ︁hin]N ccζ, N = 0, 1,…, ∞, where ℒ︁in is the interaction Liouvillian, is solved by iteration in order to obtain a generalized non‐diagonal QBE. The application to the 2D quantum Hall effect, integral and fractional, is discussed.
Strong Ultraviolet and Visible Radiative Channels of Nd3+ ‐Doped Insulating Fluoride Crystals. A New Laser Potentiality
Authors: Kaminskii A. A. , Mironov V. S. , Bagaev S. N. , Boulon G. , Djeu N. 
Published: July 2007

AbstractFor three Nd3+ ‐doped anisotropic LiKYF5, LiYF4, and KYF4 laser crystals, the main intensity characteristics of their intermanifold radiative transitions from the 2F(2)5/2, 2H(l)9/2, 4D3/2. 2P3/2, and 4F3/2 states are calculated and analyzed. Several strong ultraviolet and visible channels promising stimulated emission excitation that can considerably enhance the generating potentiality of those fluorides, are revealed. The analysis performed permits also to establish general regularities of the luminescence density distribution among intermanifold channels between high‐lying emitting states of Nd3+ ions both in the investigated fluorides and other crystals.
Analysis of Exciton Absorption Peak Broadening Contributions in InGaAs/InP Multi Quantum Wells
Authors: Arena C. , Rotelli B. , Tarricone L. 
Published: July 2007

AbstractThe excitonic absorption of InGaAs/InP multi quantum wells prepared by chemical beam epitaxy with different growth conditions and structure parameters are studied in the temperature range 8 to 300 K and in the spectral region where the heavy hole to electron (hh–e) transition corresponding to n = 1 arises. In particular, a lineshape modelling is attempted using a Gaussian function. The temperature variation of the full width at half maximum (FWHM) is discussed in terms of an intrinsic contribution Γ0 plus a thermal broadening due to the interaction with longitudinal optical (LO) phonons. The Γ0 value may be considered as a helpful parameter to investigate the structural quality of the samples studied, leading to the observation that absorption spectroscopy is a simple and powerful characterization technique of MQW.
The Effect of an Elliptic Hole on the Elastic Interaction between Screw Dislocations and a Macrocrack
Authors: Shiue Sham‐Tsong 
Published: July 2007

AbstractThe effect of an elliptic hole on the elastic interaction between a screw dislocation and a macrocrack is investigated by the conformal mapping technique. The stress field, the stress intensity factor at the crack tip, and the force on the dislocation are derived. Both the stress intensity factor at the crack tip and the force on the dislocation are strongly influenced by the elliptic hole, and are dependent on the positions of the lattice screw dislocation, the dislocations in the elliptic hole, and the geometry of the elliptic hole. If the lattice dislocation arises from the macrocrack or infinity, the lattice dislocation always has a shielding effect on the propagation of the crack. It is also found that an elliptic hole with a smaller minor semi‐axis b will induce a larger magnitude of the negative stress intensity factor at the crack tip, so it has a larger shielding effect on the crack propagation. Finally, several special cases of the results are also discussed.