bluuebunny/crossref_metadata_2025_split huggingface dataset:
NF‐κB2/p52 enhances androgen‐independent growth of human LNCaP cells via protection from apoptotic cell death and cell cycle arrest induced by androgen‐deprivation
Authors: Nadiminty Nagalakshmi , Chun Jae Yeon , Lou Wei , Lin Xin , Gao Allen C. 
Published: September 2008

AbstractPURPOSEAndrogen‐deprivation therapy only causes a temporary regression of prostate cancer, as all tumors will eventually progress to refractory to hormonal therapy after 1–3 years of treatment. The underlying mechanisms of prostate cancer androgen refractory progression are incompletely understood. In this study, we employed in vitro as well as in vivo models to examine the role of NF‐κB2/p52 in prostate cancer growth and androgen independent progression.EXPERIMENTAL DESIGNThe effects of NF‐κB2/p52 on cell growth, androgen responsiveness, cell cycle and apoptosis were examined in androgen sensitive LNCaP cells. The effect of NF‐κB2/p52 on tumor growth was examined in intact and castrated male mice.RESULTSOverexpression of NF‐κB2/p52 enhances androgen‐sensitive LNCaP human prostate cancer cell growth and clonogenic ability in androgen‐deprived condition in vitro. NF‐κB2/p52 induced androgen‐independent growth is through protecting LNCaP cells from apoptotic cell death and cell cycle arrest induced by androgen‐deprivation. In addition, NF‐κB2/p52 stimulates Cyclin D1 expression and knock down of Cyclin D1 expression by siRNA abolished NF‐κB2/p52‐induced cell growth in vitro. Adenoviral mediated NF‐κB2/p52 expression in LNCaP cells enhances tumor growth in intact male nude mice and induces tumor growth in castrated male nude mice, suggesting that overexpression of NF‐κB2/p52 induces androgen‐independent growth of androgen‐sensitive LNCaP cells.CONCLUSIONSOverexpression of NF‐κB2/p52 protects androgen sensitive LNCaP cells from apoptotic cell death and cell cycle arrest induced by androgen‐deprivation. NF‐κB2/p52 activation induces androgen‐independent growth in vitro and in vivo. Prostate © 2008 Wiley‐Liss, Inc.
In pursuit of virtual lead optimization: Pruning ensembles of receptor structures for increased efficiency and accuracy during docking
Authors: Bolstad Erin S. D. , Anderson Amy C. 
Published: September 2008

AbstractRepresenting receptors as ensembles of protein conformations during docking is a powerful method to approximate protein flexibility and increase the accuracy of the resulting ranked list of compounds. Unfortunately, docking compounds against a large number of ensemble members can increase computational cost and time investment. In this article, we present an efficient method to evaluate and select the most contributive ensemble members prior to docking for targets with a conserved core of residues that bind a ligand moiety. We observed that ensemble members that preserve the geometry of the active site core are most likely to place ligands in the active site with a conserved orientation, generally rank ligands correctly and increase interactions with the receptor. A relative distance approach is used to quantify the preservation of the three‐dimensional interatomic distances of the conserved ligand‐binding atoms and prune large ensembles quickly. In this study, we investigate dihydrofolate reductase as an example of a protein with a conserved core; however, this method for accurately selecting relevant ensemble members a priori can be applied to any system with a conserved ligand‐binding core, including HIV‐1 protease, kinases, and acetylcholinesterase. Representing a drug target as a pruned ensemble during in silico screening should increase the accuracy and efficiency of high‐throughput analyses of lead analogs. Proteins 2009. © 2008 Wiley‐Liss, Inc.
Influence of the supporting salt concentration on the electrodeposition of ZnO/eosin Y hybrid films
Authors: Boeckler C. , Oekermann T. , Saruban M. , Ichinose K. , Yoshida T. 
Published: September 2008

AbstractZnO/eosin Y hybrid films were electrodeposited from O2‐saturated ZnCl2‐solution under variation of the concentration of the supporting salt KCl. The supporting salt concentration was found to have a significant influence on the amount of dye loading and the morphology of the ZnO/eosin Y films. By decreasing the supporting salt concentration to 0.01 M KCl, porous films with a high dye loading can be obtained at potentials of –0.8 V vs. SCE at low eosin Y concentrations in the electrodeposition bath, which usually only lead to porous films at potentials where eosin Y is reduced (< –0.9 V vs. SCE). (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electrochemical synthesis of macroporous zinc oxide layers by employing hydrogen peroxide as oxygen precursor
Authors: Ramirez Daniel , Bartlett Philip , Abdelsalam Mamdouh , Gomez Humberto , Lincot Daniel 
Published: September 2008

AbstractTwo‐ and three‐dimensional ordered porous zinc oxide (ZnO) films were prepared by electrodeposition on Indium Tin Oxide coated glass, using two‐ and three‐dimensional poly(styrene) opal templates. The oxide was formed by electrochemical reduction of hydrogen peroxide in aqueous zinc perchlorate solution. Scanning electron microscopy measurements showed well ordered inverse opal structures for macroporous ZnO. At high hydrogen peroxide concentration, dense inner conformal filling was achieved for 2D and 3D structures. The formation of nanocrystalline ZnO was checked by X‐ray diffraction. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
In‐situ observation on Raman spectra and transport properties of single‐wall carbon nanotubes
Authors: Liang Chen‐Wei , Lee Wei‐Yang , Tsai Cheun‐Horng , Roth Siegmar 
Published: September 2008

AbstractAn experimental study combining Raman spectra and transport measurements on single‐walled carbon nanotubes (SWNTs) is reported. Two SWNT ropes are monitored by Raman spectroscope while applying constant current. The application of the current causes a reduction of G‐band intensity in the Raman spectra of one of the devices while the other shows no effect. A model based on the self‐heating of the nanotubes is proposed to explain the observed phenomenon. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Drift effect of fluctuation enhanced gas sensing on carbon nanotube sensors
Authors: Heszler Peter , Gingl Zoltan , Mingesz Robert , Csengeri Attila , Haspel Henrik , Kukovecz Akos , Kónya Zoltan , Kiricsi Imre , Ionescu Radu , Mäklin Jani , Mustonen Tero , Tóth Géza , Halonen Niina , Kordás Krisztián , Vähäkangas Jouko , Moilanen Hannu 
Published: September 2008

AbstractA low‐noise electronic system is built and tested for fluctuation enhanced sensing. This latter is a new technique and based on the determination of the power spectral density of the stationary resistance fluctuations of semiconductor gas sensors. Its use is advantageous for improving the chemical selectivity of sensors. However, subsequent to an initial fast change of the sensor mean resistance, as a sensor is exposed to an analyte gas, a typical drift of the resistance can be observed. This effect hinders evolving stacionary conditions and thus acquiring fast measurements when applying fluctuation enhanced sensing. Therefore, this drift effect is studied both experimentally and theoretically. Functionalized carbon nanotube layers on silicon chips serve as active material for the experimental investigations. Power spectral density functions are measured and simulated numerically with and without drift conditions. The results are compared and the effect of resistive drift on fluctuation enhanced sensing is discussed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of the catalyst drying process and catalyst support particle size on the carbon nanotubes produced by CCVD
Authors: Mionic’︁ Marijana , Alexander Duncan T. L. , Forró László , Magrez Arnaud 
Published: September 2008

AbstractCatalytic Chemical Vapour Deposition (CCVD) is considered as the most suitable technique for the large scale and low‐cost production of multiwalled carbon nanotubes. We have studied the effect of the preparation process, and of the support particle size on the catalyst efficiency, conversion yield of the carbon source and diameter of the nanotubes produced. When 50 nm calcite CaCO3 particles support the Fe2Co nanoparticles and when the catalyst is freeze dried to avoid the particles agglomeration, 85% of acetylene is converted into MWCNTs; and by using our rotary tube furnace, 1200 g of MWCNTs can be produced per day. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Infrared spectroscopy on the fullerene C70 under pressure
Authors: Thirunavukkuarasu K. , Kuntscher C. A. , Borondics F. , Klupp G. , Kamarás K. 
Published: September 2008

AbstractWe present pressure‐dependent infrared transmittance measurements on fullerene C70 at room temperature in the pressure range up to 4 GPa. The vibrational modes of C70 exhibit a nearly linear pressure dependence with a sluggish anomaly at around 0.8 GPa. This anomaly could be attributed to the change in the orientational ordering of the C70 molecules. The sluggish character of the transition could be either due to the continuous change of the orientational order or the coexistence of two phases in the solid C70. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electron transmission through step‐ and barrier‐like potentials in graphene ribbons
Authors: Klymenko Yuriy , Malysheva Lyuba , Onipko Alexander 
Published: September 2008

AbstractThe list of textbook tunneling formulas is extended by deriving exact expressions for the transmission coefficient in graphene ribbons with armchair edges and the step‐like and barrier‐like profiles of site energies along the ribbon. These expressions are obtained by matching wave functions at the interfaces between the regions, where quasiparticles have constant but different potential energies. It is shown that for an U0 high barrier and low‐energy electrons and holes, the mode transmission of charge carriers in this type of ribbons is described by the textbook formula, where the constant barrier is replaced by an effective, energy‐dependent barrier, U0 → U (E). For the lowest/highest electron/hole mode, U (E) goes, respectively, to zero and nonzero value in metallic and semiconducting ribbons. This and other peculiarities of through‐barrier/step transmission in graphene are discussed and compared with related earlier results. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Theoretical study of the electronic structure and the totally symmetric vibrations of selected CoMoCat carbon nanotubes
Authors: Kürti Jenő , Koltai János , Zólyomi Viktor 
Published: September 2008

AbstractIn situ Raman spectroelectrochemical studies of CoMo‐Cat single‐walled carbon nanotubes enriched in (6,5) tubes have been carried out recently. We performed calculations on the density functional level using local density approximation for the electronic and vibrational properties of the most abundant tubes in these samples. The following chiral semiconducting tubes were investigated: (6,4), (7,3), (6,5), (9,1), (8,3) and (7,5). The calculated and the measured frequencies of the RBM and G– modes agree within several wave numbers. The calculated E11, E22 transition energies ‐after 30% and 20% upscaling, respectively‐ are comparable with the experimental values. The quenching of the RBM band with p‐ and n‐doping can be interpreted within the rigid band approximation. The validity of the rigid band approximation was shown by calculating the density of states for neutral and charged tubes. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Statistical analysis of atomic force microscopy and Raman spectroscopy data for estimation of graphene layer numbers
Authors: Obraztsova Ekaterina A. , Osadchy Alexander V. , Obraztsova Elena D. , Lefrant Serge , Yaminsky Igor V. 
Published: September 2008

AbstractIn this work we present the results on preparation and analysis of structural and electronic properties of graphene flakes with different number of layers. Since the material electronic properties depend strongly on the layer number, a simple and reliable way to estimate this parameter should be found. In this work we propose to perform a quantitative analysis based on the atomic force microscopy (AFM) which was exploited by another authors rather as an illustrative technique. The graphene flakes were prepared by a micromechanical cleavage of highly oriented pyrolytic graphite (HOPG). Numerous flakes have been studied with AFM in order to estimate the number of graphene layers in each of them. The thickness distribution over the individual graphene flake, averaged over the all flakes investigated, has exhibited a row of maxima: 0.7 nm, 1.1 nm, 1.4 nm, 1.7 nm, 2.1 nm, etc. These values correspond perfectly to the one‐, two, three‐, and etc layers of graphene. The flakes characterized by AFM were studied afterwards with a two‐phonon Raman spectroscopy. This method is known to be sensitive to the number of layers due to a “double resonance” mechanism. To interpret the Raman spectra the electronic structure of the graphene flakes of different thickness has been calculated using the density functional method. A perfect correspondence between the number of graphene layers in different flakes measured by AFM and by Raman techniques has been obtained. This demonstrates a possibility to estimate correctly the graphene layer number using the atomic force microscopy supplied with the statistical analysis. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Lattice anharmonicity in low‐dimensional carbon systems
Authors: Bonini Nicola , Rao Rahul , Rao Apparao M. , Marzari Nicola , Menéndez José 
Published: September 2008

AbstractThe anharmonic properties of low‐dimensional carbon crystal lattices are reviewed. The energy and crystal momentum conservation rules in two‐ and one‐dimensional crystals lead to a drastic reduction of the phase space available for anharmonic phonon decay. This is illustrated with first principles calculations of the anharmonic properties of graphite and graphene. Experimental Raman linewidth data for the Radial Breathing Mode (RBM) in suspended single‐walled carbon nanotubes are also interpreted in terms of a simple model in which a phonon decay bottleneck induced by the low dimensionality leads to a population time dependence in which a fast initial decay is followed by a slow decay determined by the decay rate of a large population of secondary phonons. These results are key to understanding the combined dynamics of electrons and phonons that determines the electrical transport properties in low‐dimensional carbon nanostructures. In the case of the RBM in carbon nanotubes, they raise the intriguing possibility of using the linewidth of the Raman peak to determine the chirality of the nanotube. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Growth characteristics of chloride‐based SiC epitaxial growth
Authors: Pedersen H. , Leone S. , Henry A. , Lundskog A. , Janzén E. 
Published: September 2008

AbstractIn this study some aspects of the chloride‐based CVD growth process have been investigated by using both the approach to add HCl to the standard precursors and by using the single molecule precursor methyltrichlorosilane (MTS). The efficiency of the process for different precursors, the growth rate stability and the effect that the C/Si and Cl/Si ratios have on the growth are studied. It is found that MTS is the most efficient precursor and that the growth becomes carbon limited at C/Si < 1. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Antimicrobial activity of chitosan attached to ethylene copolymer films
Authors: Joerger Rolf D. , Sabesan Subramaniam , Visioli Donna , Urian Dave , Joerger Melissa C. 
Published: September 2008

AbstractEthylene copolymer film was coated with chitosan by attachment of the polymer to the corona‐treated surface of the film, and the composite film was analysed for antimicrobial activity. The film was active against bacteria in 0.625 mM phosphate buffer; it reduced colony counts of Escherichia coli 25922 and of Listeria monocytogenes Scott A by 5 and 2–3 log10, respectively after 24 h exposure. The activity of the chitosan‐coated film against bacteria in buffer was increased when silver ions were incorporated into the films as demonstrated by complete killing of Escherichia coli O157:H7 DD3795 and the chicken exudate isolate Stenotrophomonas maltophilia within 2 h in buffer. The film was active against L. monocytogenes Scott A in 0.5% buffered peptone water up to a pH of about 7.0. Tests on beef and chicken meat exudates revealed antimicrobial activity of the film against Escherichia coli O157:H7 and L. monocytogenes Scott A of about 2 and 1–2 log10 reductions in colony‐forming units, respectively. The antimicrobial activity of the film against L. monocytogenes Scott A was also tested on turkey breast, and a log10 reduction of about 1.7 log10 units after 10 days and 1.2 log10 after 15 days at 4°C was achieved. Exposure to chitosan‐coated film and 350 MPa of pressure, 55°C or 1% sodium diacetate resulted in a synergistic effect. Copyright © 2008 John Wiley & Sons, Ltd
Correlation of Human and Animal Air‐to‐Blood Partition Coefficients With a Single Linear Free Energy Relationship Model
Authors: Sprunger Laura M. , Gibbs Jennifer , Acree William E. , Abraham Michael H. 
Published: September 2008

AbstractPartition coefficients,Kblood, for gases and volatile organic compounds from air‐to‐blood have been collected from the published literature for human blood, rat blood, mouse blood, dog blood, rabbit blood, guinea pig blood, hamster blood, horse blood, pig blood, sheep blood, and cat blood. In total 358 partition coefficients were collected. The experimental log Kblooddata were correlated with expressions based on both the Abraham model and Goss modified Abraham model. Species indicator variables were added to the basic models to provide for interspecies variability in the observed log Kblooddata. The derived correlations describe the experimental log Kblooddata to within an approximate standard deviation of 0.31 log units. Training and test set analyses were used to validate the derived correlation models.
Global stability results for systems under sampled‐data control
Authors: Karafyllis Iasson , Kravaris Costas 
Published: September 2008

AbstractIn this work sufficient conditions for uniform input‐to‐output stability and uniform input‐to‐state stability are presented for finite‐dimensional systems under feedback control with zero‐order hold. The conditions are expressed by means of single and vector Lyapunov functions. Copyright © 2008 John Wiley & Sons, Ltd.
A control energy approach for the stabilization of the rigid beam balanced by the cart
Authors: Aguilar‐Ibañez Carlos F. , Guzmán‐Aguilar F. , Lozano Rogelio , Chimal E Juan C. 
Published: September 2008

AbstractIn this paper we present a control strategy for the stabilization of a rigid beam balanced by a cart. The control problem consists of horizontally balancing the beam by moving the cart backwards and forwards along the beam. The cart movement is restricted to always remain over the beam. The control strategy is based on the interconnection and damping assignment passivity based controller. The stability analysis is carried out using LaSalles's theorem. Copyright © 2008 John Wiley & Sons, Ltd.
A homotopy method for exact output tracking of some non‐minimum phase nonlinear control systems
Authors: Consolini L. , Tosques M. 
Published: September 2008

AbstractThis paper presents a method for non‐causal exact dynamic inversion for a class of non‐minimum phase nonlinear systems, which seems to be an alternative to those existing in the literature. This method is based on a homotopy procedure that allows to find a ‘small’ periodic solution of a desired equation by a continuous deformation of a known periodic solution of a simpler auxiliary system. This method allows to face the exact output tracking problem for some non‐minimum phase systems that are well known in the literature, such as the inverted pendulum, the motorcycle and the CTOL aircraft. Copyright © 2008 John Wiley & Sons, Ltd.
Confidence intervals for a ratio of two independent binomial proportions
Authors: Price Robert M. , Bonett Douglas G. 
Published: September 2008

AbstractSeveral large‐sample confidence intervals for the ratio of independent binomial proportions are compared in terms of exact coverage probability and width. A non‐iterative approximate Bayesian interval is derived and its frequency properties are superior to all of the non‐iterative confidence intervals considered. The approximate Bayesian interval, which is very easy to compute, has performance characteristics that are very similar to the computationally intensive score method. Two sample size determination formulas are presented, one for desired absolute precision and the other for desired relative precision. Copyright © 2008 John Wiley & Sons, Ltd.
A class comparison method with filtering‐enhanced variable selection for high‐dimensional data sets
Authors: Lusa Lara , Korn Edward L. , McShane Lisa M. 
Published: September 2008

AbstractHigh‐throughput molecular analysis technologies can produce thousands of measurements for each of the assayed samples. A common scientific question is to identify the variables whose distributions differ between some pre‐specified classes (i.e. are differentially expressed). The statistical cost of examining thousands of variables is related to the risk of identifying many variables that truly are not differentially expressed, and many different multiple testing strategies have been used for the analysis of high‐dimensional data sets to control the number of these false positives. An approach that is often used in practice to reduce the multiple comparisons problem is to lessen the number of comparisons being performed by filtering out variables that are considered non‐informative ‘before’ the analysis. However, deciding which and how many variables should be filtered out can be highly arbitrary, and different filtering strategies can result in different variables being identified as differentially expressed. We propose the filtering‐enhanced variable selection (FEVS) method, a new multiple testing strategy for identifying differentially expressed variables. This method identifies differentially expressed variables by combining the results obtained using a variety of filtering methods, instead of using a pre‐specified filtering method or trying to identify an optimal filtering of the variables prior to class comparison analysis. We prove that the FEVS method probabilistically controls the number of false discoveries, and we show with a set of simulations and an example from the literature that FEVS can be useful for gaining sensitivity for the detection of truly differentially expressed variables. Published in 2008 by John Wiley & Sons, Ltd.
The exact distribution of Cochran's heterogeneity statistic in one‐way random effects meta‐analysis
Authors: Biggerstaff Brad J. , Jackson Dan 
Published: September 2008

AbstractThe presence and impact of heterogeneity in the standard one‐way random effects model in meta‐analysis are often assessed using the Q statistic due to Cochran. We derive the exact distribution of this statistic under the assumptions of the random effects model, and also suggest two moment‐based approximations and a saddlepoint approximation for Q. The exact and approximate distributions are then applied to obtain the corresponding distributions of the recently proposed heterogeneity measures I2 and H, the power of the standard test for the presence of heterogeneity and confidence intervals for the between‐study variance parameter when the DerSimonian–Laird or the Hartung–Makambi estimator is used. The methodology is illustrated by revisiting a recent simulation study concerning the heterogeneity measures and applying all the proposed methods to four published meta‐analyses. Published in 2008 by John Wiley & Sons, Ltd.