bluuebunny/crossref_metadata_2025_split huggingface dataset:
A microtubule associated protein (hNUDC) binds to the extracellular domain of thrombopoietin receptor (Mpl)
Authors: Pan Rui‐Min , Yang Yan , Wei Ming‐Xu , Yu Xiao‐Bin , Ge Yi‐Chen , Xu Peilin 
Published: August 2005

AbstractHuman NUDC (hNUDC) was initially characterized as a nuclear migration protein based on the similarity of its C‐terminus to that of fungal NUDC from Aspergillus nidulans. However, hNUDC is a 331 amino acid protein whereas fungal NUDC is 198 amino acids in length. The extra N‐terminal portion of hNUDC has no known function or homology to other proteins. In this study, we report the binding of hNUDC to the extracellular domain of the thrombopoietin receptor (Mpl) as detected by the yeast two‐hybrid system, GST pull‐down, and co‐immunoprecipitation. Our deletion analysis demonstrated that amino acids between positions 100 and 238 as the critical domain mediating the hNUDC and Mpl interactions as detected by the two‐hybrid system and GST pull‐down assay. Immunofluorescence staining of human megakaryocyte cells indicated that hNUDC and Mpl colocalized at all stages of megakaryocyte development. Substantial colocalization of hNUDC with microtubules was also detected around nuclei and elongated microtubular structures, especially in proplatelet extensions. © 2005 Wiley‐Liss, Inc.
Cyclic AMP‐dependent modification of gonad‐selective TAFII105 in a human ovarian granulosa cell line
Authors: Wu Yimin , Lu Yunzhe , Hu Yanfen , Li Rong 
Published: August 2005

AbstractIn response to gonadotropins, the elevated level of intracellular‐cyclic AMP (cAMP) in ovarian granulosa cells triggers an ordered activation of multiple ovarian genes, which in turn promotes various ovarian functions including folliculogenesis and steroidogenesis. Identification and characterization of transcription factors that control ovarian gene expression are pivotal to the understanding of the molecular basis of the tissue‐specific gene regulation programs. The recent discovery of the mouse TATA binding protein (TBP)‐associated factor 105 (TAFII105) as a gonad‐selective transcriptional co‐activator strongly suggests that general transcription factors such as TFIID may play a key role in regulating tissue‐specific gene expression. Here we show that the human TAFII105 protein is preferentially expressed in ovarian granulosa cells. We also identified a novel TAFII105 mRNA isoform that results from alternative exon inclusion and is predicted to encode a dominant negative mutant of TAFII105. Following stimulation by the adenylyl cyclase activator forskolin, TAFII105 in granulosa cells undergoes rapid and transient phosphorylation that is dependent upon protein kinase A (PKA). Thus, our work suggests that pre‐mRNA processing and post‐translational modification represent two important regulatory steps for the gonad‐specific functions of human TAFII105. © 2005 Wiley‐Liss, Inc.
During male pronuclei formation chromatin remodeling is uncoupled from nucleus decondensation
Authors: Monardes Antonia , Iribarren Claudio , Morin Violeta , Bustos Paula , Puchi Marcia , Imschenetzky María 
Published: August 2005

AbstractMale pronucleus formation involves sperm nucleus decondensation and sperm chromatin remodeling. In sea urchins, male pronucleus decondensation was shown to be modulated by protein kinase C and a cdc2‐like kinase sensitive to olomoucine in vitro assays. It was further demonstrated that olomoucine blocks SpH2B and SpH1 phosphorylation. These phosphorylations were postulated to participate in the initial steps of male chromatin remodeling during male pronucleus formation. At final steps of male chromatin remodeling, all sperm histones (SpH) disappear from male chromatin and are subsequently degraded by a cysteine protease. As a result of this remodeling, the SpH are replaced by maternal histone variants (CS). To define if sperm nucleus decondensation is coupled with sperm chromatin remodeling, we have followed the loss of SpH in zygotes treated with olomoucine. SpH degradation was followed with anti‐SpH antibodies that had no cross‐reactivity with CS histone variants. We found that olomoucine blocks SpH1 and SpH2B phosphorylation and inhibits male pronucleus decondensation in vivo. Interestingly, the normal schedule of SpH degradation remains unaltered in the presence of olomoucine. Taken together these results, it was concluded that male nucleus decondensation is uncoupled from the degradation of SpH associated to male chromatin remodeling. From these results, it also emerges that the phosphorylation of SpH2B and SpH1 is not required for the degradation of the SpH that is concurrent to male chromatin remodeling. © 2005 Wiley‐Liss, Inc.
Inhibitory effects of thioredoxin reductase antisense RNA on the growth of human hepatocellular carcinoma cells
Authors: Gan Lu , Yang Xiang‐Liang , Liu Qiong , Xu Hui‐Bi 
Published: August 2005

AbstractThioredoxin reductase (TrxR) in conjunction with thioredoxin (Trx) is a ubiquitous intracellular oxidoreductase system with antioxidant and redox regulatory roles. In some human tumors, the thioredoxin system is found overexpressed. We have used an antisense approach to investigate whether inhibition of TrxR overexpression can suppress the growth of human hepatocellular carcinoma SMMC‐7721 cells. TrxR cDNA fragment was inserted in the antisense direction into pcDNA3.1/myc‐His and SMMC‐7721 cells were stably transfected with the plasmid construct. The results showed that TrxR antisense RNA could significantly reduce TrxR mRNA level and activity, and suppress the growth of SMMC‐7721 cells. Cell‐cycle analysis showed G2/M phase arrest in SMMC‐7721 cells transfected with TrxR antisense plasmid. TrxR antisense RNA could significantly increase p53 mRNA level and decrease Bcl‐2 mRNA level by reverse transcriptase‐polymerase chain reaction (RT‐PCR). Furthermore a significant decrease in human telomerase reverse transcriptase (hTERT) mRNA level was found in SMMC‐7721 cells transfected with TrxR antisense plasmid. Flow cytometry and telomere fluorescence in situ hybridization (Flow FISH) showed that TrxR antisense RNA could significantly reduce the telomere fluorescence in SMMC‐7721 cells. The results suggested that TrxR antisene RNA inhibited the growth of SMMC‐7721 cells through an accumulation of cell cycle at G2/M phase, an increase in p53 mRNA level and a reduction in telomere fluorescence and Bcl‐2, hTERT mRNA levels. © 2005 Wiley‐Liss, Inc.
Protein structure prediction with the UNRES force‐field using Replica‐Exchange Monte Carlo‐with‐Minimization; Comparison with MCM, CSA, and CFMC
Authors: Nanias Marian , Chinchio Maurizio , Ołdziej Stanisław , Czaplewski Cezary , Scheraga Harold A. 
Published: August 2005

AbstractTwo current methods of global optimization are coupled to produce the Replica‐Exchange method together with Monte Carlo‐with‐Minimization (REMCM). Its performance is compared with each separate component and with other global optimization techniques. REMCM was applied to search the conformational space of coarse grain protein systems described by the UNRES force field. The method consists of several noninteracting copies of Monte Carlo simulation, and minimization was used after every perturbation to enhance the sampling of low‐energy conformations. REMCM was applied to five proteins of different topology, and the results were compared to those from other optimization methods, namely Monte Carlo‐with‐Minimization (MCM), Conformational Space Annealing (CSA), and Conformational Family Monte Carlo (CFMC). REMCM located global minima for four proteins faster and more consistently than either MCM or CFMC, and it converged faster than CSA for three of the five proteins tested. A performance comparison was also carried out between REMCM and the traditional Replica Exchange method (REM) for one protein, with REMCM showing a significant improvement. Moreover, because of its simplicity, REMCM was easy to implement, thereby offering an alternative to other global optimization methods used in protein structure prediction. © 2005 Wiley Periodicals, Inc. J Comput Chem 26: 1472–1486, 2005
Minimum vertex‐diameter‐2‐critical graphs
Authors: Chen Ya‐Chen , Füredi Zoltán 
Published: August 2005

AbstractWe prove that the minimum number of edges in a vertex‐diameter‐2‐critical graph on n ≥ 23 vertices is (5n − 17)/2 if n is odd, and is (5n/2) − 7 if n is even. © 2005 Wiley Periodicals, Inc. J Graph Theory
Two‐dimensional numerical simulation of short‐gate‐length gaAs MESFETs and application to the travelling gunn domain phenomenon
Authors: El‐Ghazaly Samir , Itoh Tatsuo 
Published: August 2005

AbstractThe Boltzmann transport equation is used to derive a set of conservation equations which is capable of describing the electron transport phenomena in a single‐valley semiconductor. These conservation equations are averaged over the different valleys of the conduction band to develop another set of equations that can be used to describe accurately the electron transport phenomena in a multi‐valley semiconductor, such as GaAs, using the equivalent single‐electron gas model whose characteristics are the average weighted characteristics of the constituent gases. The nonstationary effects are included by using energy dependent mobility and electron temperature functions. This program is used to simulate a GaAs MESFET with a 0·5 μm gate length and a 0.2 μm thick active layer. The active layer is doped at 1017 cm−3. A travelling Gunn domain is observed between the gate and the drain. The domain oscillation frequency is much higher than the normal operating frequency of the MESFET. The domain formation's dependence on the gate bias and the active layer thickness are also presented.
Coupling between electromagnetic fields and multiconductor transmission systems using TLM
Authors: Christopoulos C. , Naylor P. 
Published: August 2005

AbstractThe coupling between incident electromagnetic fields and lossless multiconductor transmission systems is studied using transmission‐line modelling‐(TLM) and the impedance parameters of the transmission system. This calculation is a two‐stage procedure:firstly, the field problem is solved, with no conductors present, to give the incident fields; secondly, the multiconductor transmission‐line problem is solved using equivalent voltage and current sources representing coupling from the incident fields. Comparison of these results with previously published work shows excellent agreement. The numerical model presented is particularly suitable for studying electromagnetic compatibility problems.
Characterization of coupled finlines by generalized transverse resonance method
Authors: Schiavon Giovanni , Sorrentino Roberto , Tognolatti Piero 
Published: August 2005

AbstractThe conventional transverse resonance method, which has been widely used for the approximate characterization of a number of guiding structures and leaky wave antennas, is formulated in a generalized form. The transverse resonance viewpoint combined with the generalized matrix representation of discontinuities yields a rigorous transverse equivalent circuit of the guiding structure.This technique is used to compute the characteristics of both symmetrical and asymmetrical double slot unilateral finlines in terms of phase constant and characteristic impedance of the dominant as well as higher‐order modes. Numerical aspects of this method are discussed.In a double‐slot finline structure, a coupled‐mode regime is established with the onset of the first higher‐order mode in addition to the dominant quasi‐TEM mode. Symmetrical structures are simply modelled in terms of even and odd mode characteristics, but a more general coupled‐line model, in terms of the C‐mode and the II‐mode must be applied to asymmetrical coupled finlines.
Application of the symmetrized transmission‐line matrix method to the cold modelling of magnetrons
Authors: Allen R. , Clark M. J. 
Published: August 2005

AbstractTwo‐ and three‐dimensional electromagnetic resonance calculations have been performed on rising‐sun magnetron structures. These calculations have been made using the transmission‐line matrix method. Cylindrical coordinates have been used in order to facilitate modelling of the essentially cylindrical device. Recent improvements to the TLM technique, such as the development of the symmetric condensed node for electromagnetics, have been fully exploited. The numerical procedure is described, the modelling process is discussed, and the results obtained are evaluated in comparisons with corresponding empirical data.
Weighted Gaussian quadratures for singular and near ‐singular integrands
Authors: Silvester Peter P. 
Published: August 2005

AbstractNumerical quadratures encountered in solving integral equations and in finite element analysis often involve singular integrands, or integrands with very rapid local variation whose numerical stability resembles that of singularities. It is shown that specialized quadrature formulae of Gauss–Christoffel type can be generated for such integrands, using a recursive procedure based on the properties of the underlying orthogonal polynomials. Quadrature formulae of moderately high degree can be computed rapidly enough to allow them to be constructed as needed. An algorithm for generating quadrature formulae is given in detail. Singular or near ‐singular functions encountered in finite element analysis typically require three ‐point or four ‐point quadratures; such formulae are readily obtained, to seven ‐figure accuracy, in computing times short enough to regard the formulae as disposable and not worth preserving in tables.
Efficient direct and iterative electrodynamic analysis of geometrically complex MIC and MMIC structures
Authors: Wertgen W. , Jansen R. H. 
Published: August 2005

AbstractRigorous full ‐wave analysis techniques are presently receiving much attention in the design of MICs and, in particular, of MMICs due to increasing circuit packing densities and structural complexity. In this paper, the problems associated with such techniques and previous related work are briefly outlined in the introduction. To obtain self ‐consistency, the electrodynamic Green's functions and related terms are then formulated for the shielded (M)MIC problem. The final operator equation for the numerical solutions derived and the associated functions space are presented and discussed. The central portion of the paper describes a new numerical solution using a discretized Green's function database technique. The resulting linear system of equations is solved by direct inversion for geometrical complexities involving up to about 1000 unknowns; for a higher number of unknowns, an iterative solution is generated. As an alternative to the database technique developed, a variety of spectral domain iterative solutions has been written and tested as well. This includes application of the conjugate gradient method to the normal operator equation (CGN algorithm), an implicit iterative Galerkin approximation called the modified planar conjugate gradient technique (MPCG) and monotonically convergent iteration procedure being a version of the conjugate residual algorithm (CR). Supplementary to this, the extraction of (M)MIC design data from the numerical 3D solutions obtained and error considerations are presented. The paper concludes with a variety of analysis examples of medium to high geometrical complexity and with verification of some results by comparison with measurements and with numerical data from other sources.CPU times required on typical workstations (Micro VAX, HP 9000, etc.) are moderate, thus rendering the techniques presented as useful in the solution of MIC and MMIC design problems.
Computation of the electromagnetic field distribution inside enclosures with apertures using 3‐D FEM
Authors: Ladd Darcy N. , Costache George I. 
Published: August 2005

AbstractKnowledge of the electromagnetic field distribution inside electronic enclosures due to incident fields is of interest to EMC design engineers. In this paper, a three‐dimensional formulation of the finite element method was developed to solve the electromagnetic field distribution inside metal enclosures with apertures. The formulation was developed using a three‐component vector magnetic potential and a scalar electric potential. The displacement current as well as the conduction current term was included. The region of interest was discretized using eight‐node isoparametric hexahedrons and the potential functions were defined using linear first‐order basis functions. The penetration of a steady‐state electromagnetic field through an aperture into a simple cavity was analysed with the 3‐D FEM program.
Time‐domain calculation of electromagnetic plane‐wave induced surges on overhead transmission lines
Authors: Seltner Ph. , Pardo‐Gibson O. , Auriol Ph. 
Published: August 2005

AbstractThis paper presents a time‐domain method to calculate electromagnetic plane wave induced surges on overhead multiconductor transmission lines. By means of some particular line impulse responses, the method takes into account the distributed nature of the coupling with plane wave radiated fields. A comparison of measured plane‐wave induced voltages reported in the literature and calculated voltages shows a very close agreement.
Propagation of picosecond pulses in superconducting microstrip interconnections on integrated circuits
Authors: Sali S. 
Published: August 2005

AbstractStudies on the propagation of picosecond pulses in coupled microstrip line interconnections on silicon integrated circuit substrates are presented. The effects of conductor and dielectric losses in the transmission line on the distortion, delay and attenuation of picosecond pulses are studied in detail. A direct comparison is made with the propagation characteristics of interconnects using ordinary metals and high‐temperature superconductors such as YBa2Cu3O7. The results generally show the advantages of using high‐temperature superconductor tracks on low‐loss integrated circuit substrates such as GaAs. However, even in this case, geometrical dispersion can cause distortion on the pulses and it is therefore an important factor to be considered.
Calculation of radiated electromagnetic fields from electronic systems
Authors: Öing S. , John W. , Mrozynski G. 
Published: August 2005

AbstractThe electromagnetic radiation from electronic systems is formulated in terms of an integral equation for the electric and the equivalent magnetic current density, which is numerically solved by the method of moments. The electromagnetic coupling to conducting thin wires, thin plates, and aperture fitted cabinets is taken into account by appropriate operator equations.In order to solve the integral equation of electrically large conducting structures, suitable basis functions are needed to minimize the computation time. B‐spline functions of the second and third degree are used as a basis in the moment method, which lead to a decrease of the computation time.A second way to decrease the computation time is given by the possibility of determining which parts of the structure of a printed circuit board (PCB) have to be considered and which parts can be neglected. Examples show that the influence of near source conducting areas to the radiated emissions is strong. It will be shown that this influence depends on the geometrical symmetry, the shape, and the distance of the scattering body.
Efficient analytical‐numerical modelling of ultra‐wideband pulsed plane wave scattering
Authors: Carin Lawrence , Felsen Leopold B. 
Published: August 2005

AbstractUltra‐wideband (UWB) pulsed plane wave scattering from a large but finite strip grating in free space is analysed in the frequency domain via decomposition into plane wave spectra, implemented numerically by the method of moments, and then inverted into the time domain (TD). To make this procedure practical under UWB conditions, closed form expressions are derived for interaction integrals involving widely separated expansion and testing functions. These closed forms are based on a judicious choice of the basis functions, and on asymptotic methods for reducing the integrals. Although large separation distances are assumed, the expressions have been found to be accurate for separations as small as 0·1 wavelengths. The TD self terms can also be evaluated efficiently. To test the frequency domain algorithm, comparisons are made with available data in the literature for surface currents and far‐field scattering from multiple strips. New short pulse TD results are shown as well.
Spatially weighted numerical models for the two‐dimensional wave equation: FD algorithm and synthesis of the equivalent TLM model
Authors: Simons N. R. S. , Sebak A. A. 
Published: August 2005

AbstractIn this paper a new TLM model for the two‐dimensional wave equation is introduced. It is synthesized directly from a FD algorithm. The FD algorithm is second‐order‐accurate in both space and time, and is explicitly time‐stepped. The spatial derivatives in the FD algorithm are approximated by the weighted combination of two standard central difference stencils, one oriented as usual, the other rotated by 45° with its arms extended by a factor of (2)1/2. The TLM model is realized as the weighted connection of two original models (with the same geometrical configuration as the FD algorithm). The weighting in the TLM model is accomplished by using a variable intrinsic impedance for specific elemental transmission lines. The FD and TLM methods possess identical dispersion relations if the former is operated at its upper limit of stability. Therefore, under these conditions both represent identical models for the simulation of wave propagation. The propagation characteristics of the new model are investigated and the conditions for approximate numerical isotropy are provided. The numerical implementation (scattering matrix and transfer event) is described. To validate the new model, the calculation of cutoff frequencies of various modes in rectangular waveguide is performed. Comparison with analytical results (for an unfilled waveguide) and other numerical results (for a waveguide partially filled with a dielectric) validate the implementation of the model.
Multiport approach for the analysis of microwave non‐linear networks
Authors: Sobhy M. I. , Hosny E. A. , Nassef M. A. 
Published: August 2005

AbstractThe state and output equations of the overall networks are derived from the state and output equations of individual multiports and knowledge of the interconnections between them. A generalized lumped‐distributed L/D multiport is described by its associated state, output and non‐linear equations in the time domain. Any network can be considered as composed of a set of multiports and independent sources. These equations have been incorporated into a computer‐aided procedure for the analysis of L/D networks. The procedure can be used for the simulation of any non‐linear microwave circuit and offers the facility of developing a multiport equivalent circuit for any linear or non‐linear device or subcircuit. Several examples are successfully analysed using the developed general program.
Circuit model for a symmetrical condensed TLM node
Authors: Mlakar J. 
Published: August 2005

AbstractAn equivalent circuit for a symmetrical condensed TLM node is presented. The basic circuit has twelve ports and consists of 24 1:1 ideal transformers. Three additional conductances model the conductivity of the medium. The circuit is extended with additional ideal transformers giving six ports for short‐circuit and open‐circuit stubs which model the permittivity and permeability of the inhomogeneous medium. The scattering matrix of the 18‐port network is determined symbolically by solving a set of linear circuit equations. The matrix agrees with previously published results for a symmetrical condensed TLM node, obtained from Maxwell's equations.