bluuebunny/crossref_metadata_2025_split huggingface dataset:
A single‐feed wide‐ and dualband cavity‐backed slot antenna
Authors: Liu Yijun , Shen Zhongxiang , Chin H. C. , Lim W. L. 
Published: April 2007

AbstractA compact design for a single‐feed cavity‐backed slot antenna is presented for operating at GSM (900 MHz) and DCS (1800 MHz). With the use of a carefully designed power distribution network, a single‐feed design is realized for a dual‐ and wideband slot antenna with high gain and good radiation patterns. Measured results show that the antenna has a wide bandwidth at both frequency bands and it exhibits high gain and good radiation patterns, which is desirable for many dualband applications.© 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1570–1572, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22549
Broadband dual‐frequency CPW‐FED antenna with a cross‐shaped feeding line for WLAN application
Authors: Liu Wen‐Chung 
Published: April 2007

AbstractA novel and simple design of a coplanar waveguide‐fed planar monopole antenna with broadband dual‐frequency operation for wireless local area network (WLAN) application is proposed. Good impedance matching for dual‐resonance mode is obtained by feeding the radiating patch with a cross‐shaped strip line. Prototypes of the obtained design have been constructed and experimentally studied. The measured results explore broad dual‐frequency operation with (10 dB impedance bandwidths of 30%, ranging from 2.23 to 2.96 GHz, and 56.7%, ranging from 4.6 to 7.62 GHz, at bands of 2.43 and 5.33 GHz, respectively, which cover the 2.4/5.2/5.7 GHz WLAN operating bands, and show good agreement with the numerical prediction. Good monopole‐like radiation patterns and sufficient antenna gains over the operating bands have also been observed. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1739–1744, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22551
An ultra‐wideband stacked microstrip patch antenna
Authors: Ang Irene , Ooi B. L. 
Published: April 2007

AbstractA novel ultra‐wideband (UWB) stacked microstrip patch antenna suitable for UWB application is presented in this article. This compact and planar proposed antenna is found to have a very broad impedance bandwidth as compared to the conventional electromagnetic coupled antenna. The proposed antenna is able to achieve an impedance bandwidth of about 101.8% for VSWR less than 2, centred at around 7 GHz. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1659–1665, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22555
Fractal‐shaped stepped‐impedance transformers for wideband application
Authors: Chen Wen‐Ling , Wang Guang‐Ming , Qi Yi‐Na , Liang Jian‐Gang 
Published: April 2007

AbstractMicrostrip stepped‐impedance transformers using a Sierpinski fractal shape are proposed for the first time. The proposed fractal‐shaped stepped‐impedance transformers can greatly enhance the operating frequency bandwidth. Bandwidth up to 44.0% and 73.9% (S11≤−30 dB) have been achieved by the presented two‐section and three‐section fractal‐shaped maximal flat stepped‐impedance transformers, respectively. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1628–1630, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22557
All‐optical logic or gate using two cascaded semiconductor optical amplifiers
Authors: Hamié Ali , Sharaiha Ammar , Guégan Mikael , Le Bihan Jean , Hamzé Adnan 
Published: April 2007

AbstractA novel all‐optical logic OR gate based on cross‐gain modulation (XGM) using a two‐cascaded semiconductor optical amplifiers (SOAs) in a counterpropagating topology is presented. The attractive issue of the proposed method is that the logic OR gate can be obtained at a probe wavelength by taking advantage of the positive gain variation of one of the two used SOAs in the counterpropagating configuration. This reported feasibility study shows the all‐optical logic OR gate can be easily achieved with an extinction ratio higher than 7 dB.© 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1568–1570, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22560
Mechanism study of mechanical tuning in HTS filter application
Authors: Peng Huili , Zhang Xiaoping , Guo Xubo , Mu Lijuan , Wei Bin , Gao Baoxin , Cao Bisong 
Published: April 2007

AbstractMechanical tuning method using sapphire and copper rods for high temperature superconducting filters is presented. A three‐pole microstrip filter and a two‐pole patch filter were fabricated and tuned. Results show that the center frequency shifts toward lower end in dielectric tuning and toward either lower end or higher end in metallic tuning depending on the local electromagnetic field distribution.© 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1565–1568, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22561
Telomere length status of somatic cell sheep clones and their offspring
Authors: Alexander Basil , Coppola Gianfranco , Perrault Steven D. , Peura Teija T. , Betts Dean H. , King W. Allan 
Published: April 2007

AbstractThis study was carried out to determine the telomere length status of sheep clones and their offspring, and to examine telomere dynamics and chromosomal abnormalities in culture propagated donor cells. Skin samples were collected from somatic cell nuclear transfer‐derived sheep clones, and three of their progeny generated by natural mating. Samples were collected from control animals (n = 35), spanning in age from 1 month to 36 months of age. Genomic DNA was extracted from cell/tissue samples and their telomere lengths were assessed by terminal restriction fragment (TRF) analysis. Results revealed: that (a) sheep clones derived from cultured somatic cells have shortened telomere lengths compared to age‐matched controls; (b) the offspring derived from natural mating between clones had normal telomere lengths compared to their age‐matched counterparts; and donor cell cultures beyond 20 population doublings had significantly (P < 0.05) shortened telomeres and exhibited a higher numerical and structural chromosomal abnormalities. Mol. Reprod. Dev. 74: 1525–1537, 2007. © 2007 Wiley‐Liss, Inc.
Determining elastic constants of transversely isotropic rocks using Brazilian test and iterative procedure
Authors: Chou Yen‐Chin , Chen Chao‐Shi 
Published: April 2007

AbstractThe elastic constants of rocks are the basic parameters for rock mechanics, and play a very important role in engineering design. There are many laboratory methods to determine the elastic constants of transversely isotropic rocks, and the Brazilian test is a popular method. This paper presented a method combination of the Brazilian test, back calculation, and iterative procedure to evaluate the five independent elastic constants of transversely isotropic rocks in laboratory.
The strain data at the centre of discs were obtained using Brazilian test. The stresses at the centre of discs were computed using numerical programs. By using back calculation, the temporary elastic constants were computed after the stresses and stains were substituted into elastic mechanics equations. After iterative procedure, the convergent values of the elastic constants can be obtained. One numerical example and three experimental cases were proposed to show the applicability of this method. The convergent values of the five independent elastic constants can be obtained in no more than 10 iterative cycles. The results coming from numerical analysis method exhibited satisfactory outcome in accordance with those of generalized reduced gradient method. The merits of this method include convenient specimen preparation of the Brazilian test, simple iterative procedure, and readily available commercially numerical programs, so that this method can be easily popularized in research and engineering analysis. Copyright © 2007 John Wiley & Sons, Ltd.
The prevalence and risk factors of urinary incontinence and its influence on the quality of life among Egyptian women
Authors: El‐Azab Ahmed S. , Mohamed Eman M. , Sabra Hanaa I. 
Published: April 2007

AbstractAimsThe exact magnitude of the problem of urinary incontinence (UI) in Egypt is not yet reported. We studied the prevalence and potential risk factors associated with UI among a group of Egyptian women as taken from a representative sample from the population.MethodsDesign: A cross‐sectional, community‐based study. Setting: Assiut, Upper Egypt, Egypt. Participants: women, aged 20 years and older, selected randomly from the population. Measurements: Participants completed a previously validated questionnaire; Urogenital Distress Inventory‐short form (UDI‐6).ResultsA total of 1,652 women were included. The prevalence of UI among our study subjects is 54.8%. Aging, low educational level, menopause, higher parity (>3), vaginal delivery, and previous multiple abortions (>3) were found to be significantly associated with UI. The prevalence of urge, stress and mixed incontinence, mutually exclusive of each other, was 15%, 14.8%, and 25%, respectively. The prevalence of severe incontinence is 8.4%. Regarding the quality of life, the most distressing issues for sufferers were their inability to pray (90%).ConclusionsUI is quite common in Egypt and prevalence rates are higher when compared to other reports. Neurourol. Urodynam. 26:783–788, 2007. © 2007 Wiley‐Liss, Inc.
Elevating tensor rank increases anisotropy in brain areas associated with intra‐voxel orientational heterogeneity (IVOH): a generalised DTI (GDTI) study
Authors: Minati L. , Banasik T. , Brzezinski J. , Mandelli M.L. , Bizzi A. , Bruzzone M.G. , Konopka M. , Jasinski A. 
Published: April 2007

AbstractRank‐2 tensors are unable to represent multi‐modal diffusion associated with intra‐voxel orientational heterogeneity (IVOH), which occurs where axons are incoherently oriented, such as where bundles intersect or diverge. Under this condition, they are oblate or spheroidally shaped, resulting in artefactually low anisotropy, potentially masking reduced axonal density, myelinisation and integrity. Higher rank tensors can represent multi‐modal diffusion, and suitable metrics such as generalised anisotropy (GA) and scaled entropy (SE) have been introduced. The effect of tensor rank was studied through simulations, and analysing high angular resolution diffusion imaging (HARDI) data from two volunteers, fit with rank‐2, rank‐4 and rank‐6 tensors. The variation of GA and SE as a function of rank was investigated through difference maps and region of interest (ROI)‐based comparisons. Results were correlated with orientation distribution functions (ODF) reconstructed with q‐ball, and with colour‐maps of the principal and second eigenvectors. Simulations revealed that rank‐4 tensors are able to represent multi‐modal diffusion, and that increasing rank further has a minor effect on measurements. IVOH was detected in subcortical regions of the corona radiata, along the superior longitudinal fasciculus, in the radiations of the genu of the corpus callosum, in peritrigonal white matter and along the inferior fronto‐occipital and longitudinal fascicula. In these regions, elevating tensor rank increased anisotropy. This was also true for the corpus callosum, cingulum and anterior limb of the internal capsule, where increasing tensor rank resulted in patterns that, although mono‐modal, were more anisotropic. In these regions the second eigenvector was coherently oriented. As rank‐4 tensors have only 15 distinct elements, they can be determined without acquiring a large number of directions. By removing artefactual underestimation of anisotropy, their use may increase the sensitivity to pathological change. Copyright © 2007 John Wiley & Sons, Ltd.
Effects of AZD2171 and vandetanib (ZD6474, Zactima) on haemodynamic variables in an SW620 human colon tumour model: an investigation using dynamic contrast‐enhanced MRI and the rapid clearance blood pool contrast agent, P792 (gadomelitol)
Authors: Bradley D. P. , Tessier J. L. , Checkley D. , Kuribayashi H. , Waterton J. C. , Kendrew J. , Wedge S. R. 
Published: April 2007

AbstractThe effect of two novel therapeutic agents on tumour haemodynamics was investigated using a fast dynamic contrast‐enhanced (DCE)‐MRI protocol (0.5 s/image) sensitive to signal changes in both the vascular input function and tumour during the administration of the macromolecular rapid clearance blood pool agent (MM‐RCBPA), gadomelitol (P792, Vistarem). This enabled simultaneous measurement of the tumour blood flow per unit volume of tissue (F/VT, mL/s/mL), the fractional plasma volume (Vp, %), and the permeability surface area product per unit volume of tissue (PSρ, s−1) in subcutaneous SW620 human colorectal tumour xenografts grown in nude rats before and after (at 0 and 22 h; imaging at 24 h) acute treatment with AZD2171 (3 mg/kg) and vandetanib (ZD6474, Zactima; 50 mg/kg), which have inhibitory activity against vascular endothelial growth factor receptor‐2 (VEGFR‐2) tyrosine kinase. MRI was performed at 4.7 T using a single‐slice, modified, T1‐weighted, spoiled gradient‐echo technique. Both compounds reduced gadomelitol uptake into the tumour. AZD2171 and vandetanib, respectively, (a) greatly reduced PSρ to 19.7 ± 9.5% and 28.9 ± 14.1% of baseline (P = 0.007 and P = 0.02), (b) markedly reduced Vp to 31.2 ± 19.1% and 54.8 ± 21.2% of baseline (P = 0.015 and P = 0.09), and (c) had no significant effect on F/VT. There was no significant difference between groups treated with AZD2171 and vandetanib when each variable was compared. The reductions in PSρ and Vp are consistent with inhibition of VEGF signalling. AZD2171 (3 mg/kg) and vandetanib (50 mg/kg) were also found to produce a comparable chronic inhibition of SW620 tumour growth (89% for both). This study shows that DCE‐MRI using an MM‐RCPBA can be used to distinguish tumour vascular flow, volume, and permeability surface area product in a tumour model, and enables the acute effects of VEGF signalling inhibition to be examined in detail. Copyright © 2007 John Wiley & Sons, Ltd.
Viscoelasticity in polymers: Phenomenological to molecular mathematical modeling
Authors: Banks H.T. , Luke N.S. , Samuels J.R. 
Published: April 2007

AbstractWe report on two recent advances in the modeling of viscoelastic polymers: (i) a new constitutive model that combines the virtual stick‐slip continuum “molecular‐based” ideas of Johnson and Stacer with the Rouse bead chain ideas; (ii) a two‐dimensional version of a model that accounts for stenosis‐driven shear wave propagation in biotissue. © 2007 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 23: 817–831, 2007
Improving the performance of perfectly matched layers by means of hp‐adaptivity
Authors: Michler C. , Demkowicz L. , Kurtz J. , Pardo D. 
Published: April 2007

AbstractWe improve the performance of the Perfectly Matched Layer (PML) by using an automatic hp‐adaptive discretization. By means of hp‐adaptivity, we obtain a sequence of discrete solutions that converges exponentially to the continuum solution. Asymptotically, we thus recover the property of the PML of having a zero reflection coefficient for all angles of incidence and all frequencies on the continuum level. This allows us to minimize the reflections from the discrete PML to an arbitrary level of accuracy while retaining optimal computational efficiency. Since our hp‐adaptive scheme is automatic, no interaction with the user is required. This renders tedious parameter tuning of the PML obsolete. We demonstrate the improvement of the PML performance by hp‐adaptivity through numerical results for acoustic, elastodynamic, and electromagnetic wave‐propagation problems in the frequency domain and in different systems of coordinates. © 2007 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 23: 832–858, 2007
Modeling and numerical analysis of masonry structures
Authors: Ainsworth Mark , Mihai L. Angela 
Published: April 2007

AbstractWe model masonry structures as elastodynamic systems assembled from a large number of elastic bodies (bricks or stone‐blocks) in unilateral, frictional contact. The problem is formulated as a quasi‐variational inequality and discretised using piecewise polynomial finite elements in conjunction with an energy consistent time integration scheme. At each time‐step, the quasi‐variational inequality is reformulated as a nonlinear complementarity problem. An iterative splitting of the contact problem into normal contact and frictional contact, together with a primal‐dual active‐set method is employed to calculate deformations and openings in the model structures. Numerical results are presented to illustrate the efficiency of the resulting approach in predicting the mechanical behaviour of a bidimensional arch‐ring made of bricks, deformed due to body forces and surface tractions. © 2007 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 23: 798–816, 2007
Robust domain decomposition algorithms for multiscale PDEs
Authors: Graham I.G. , Scheichl R. 
Published: April 2007

AbstractIn this article, we describe a new class of domain decomposition preconditioners suitable for solving elliptic PDEs in highly fractured or heterogeneous media, such as arise in groundwater flow or oil recovery applications. Our methods employ novel coarsening operators, which are adapted to the heterogeneity of the media. In contrast to standard methods (based on piecewise polynomial coarsening), the new methods can achieve robustness with respect to coefficient discontinuities even when these are not resolved by a coarse mesh. This situation arises often in practical flow computation, in both the deterministic and (Monte‐Carlo simulated) stochastic cases. An example of a suitable coarsener is provided by multiscale finite elements. In this article, we explore the linear algebraic aspects of the multiscale algorithm, showing that it involves a blend of both classical overlapping Schwarz methods and nonoverlapping Schur methods. We also extend the algorithm and the theory from its additive variant to obtain new hybrid and deflation variants. Finally, we give extensive numerical experiments on a range of heterogeneous media problems illustrating the properties of the methods. © 2007 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 23: 859–878, 2007
Iteratively coupled mixed and Galerkin finite element methods for poro‐elasticity
Authors: Wheeler Mary F. , Gai Xiuli 
Published: April 2007

AbstractWe present a finite element formulation for coupled flow and geomechanics. We use mixed finite element spaces to approximate pressure and continuous Galerkin methods for displacements. In solving the coupled system, pressure and displacements can be solved either simultaneously in a fully coupled scheme or sequentially in a loosely coupled scheme. In this paper we formulate an iterative method where pressure and displacement solutions are staggered during a time step until a convergence tolerance is satisfied. A priori convergence results for the iterative coupling are also presented, along with a summary of the convergence results for the fully coupled scheme. © 2007 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 23: 785–797, 2007
Malaria Plasmodium agent induces alteration in the head proteome of their Anopheles mosquito host
Authors: Lefevre Thierry , Thomas Frédéric , Schwartz Alex , Levashina Elena , Blandin Stéphanie , Brizard Jean‐Paul , Le Bourligu Laure , Demettre Edith , Renaud François , Biron David G. 
Published: April 2007

AbstractDespite increasing evidence of behavioural manipulation of their vectors by pathogens, the underlying mechanisms causing infected vectors to act in ways that benefit pathogen transmission remain enigmatic in most cases. Here, 2‐D DIGE coupled with MS were employed to analyse and compare the head proteome of mosquitoes (Anopheles gambiae sensu stricto (Giles)) infected with the malarial parasite (Plasmodium berghei) with that of uninfected mosquitoes. This approach detected altered levels of 12 protein spots in the head of mosquitoes infected with sporozoites. These proteins were subsequently identified using MS and functionally classified as belonging to metabolic, synaptic, molecular chaperone, signalling, and cytoskeletal groups. Our results indicate an altered energy metabolism in the head of sporozoite‐infected mosquitoes. Some of the up‐/down‐regulated proteins identified, such as synapse‐associated protein, 14‐3‐3 protein and calmodulin, have previously been shown to play critical roles in the CNS of both invertebrates and vertebrates. Furthermore, a heat shock response (HSP 20) and a variation of cytoarchitecture (tropomyosins) have been shown. Discovery of these proteins sheds light on potential molecular mechanisms that underlie behavioural modifications and offers new insights into the study of intimate interactions between Plasmodium and its Anopheles vector.
Relaxation processes in PVAc‐HA nanocomposites
Authors: Kalfus J. , Jancar J. 
Published: April 2007

AbstractFundamental principles of polymer physics were used for description of relaxation behavior of polymer chain near solid surface. In a nanocomposite, considerable portion of polymer matrix is in contact with the filler surface even at very low filler loadings. In this study, nanocomposite was considered as a two component system consisting of (i) bulk polymer matrix and (ii) effective particles composed of adsorbed polymer shell and filler particle core. Both polymer phases, i.e., bulk and immobilized, are able to relax, however, each of them on a different time scale. Thus, above the neat matrix Tg, these two phases undergo (i) free and (ii) retarded reptation dynamics due to the adsorption processes on the filler surface, respectively. Relaxation time was calculated for each phase using the reptation theory. To calculate the mixed response of the whole polymer nanocomposite, a simple rule of mixtures model and percolation model were used. Calculated composite relaxation times were correlated with experimental modulus recovery data measured after the Payne effect in poly(vinylacetate)‐hydroxyapatite nanocomposite. Good agreement was found between theoretical predictions and experimental data. © 2007 Wiley Periodicals, Inc. JPolym Sci Part B: Polym Phys 45: 1380–1388, 2007
Isothermal crystallization studies of poly(butylene terephthalate) composites
Authors: Al‐Mulla Adam , Mathew Johnson , Shanks Robert 
Published: April 2007

AbstractDifferent crystallization kinetic models (Avrami and Tobin) have been applied to study the crystallization kinetics of virgin poly(butylene terephthalate) (PBT) and filled PBT systems under isothermal experimental conditions. The experimental data have been analyzed with a nonlinear, multivariable regression program. The kinetic parameters for the isothermal crystallization have been determined. The analysis results indicate that both models satisfactorily represent the isothermal crystallization kinetics. PBT crystallizes most slowly. The presence of nanoclays or nanofibers, added as fillers, enhances the crystallization rate of PBT composites. An analysis of the kinetic data with the Avrami and Tobin models has shown little change in the crystallization exponent compared with that of virgin PBT. The crystallization rate constant decreases with a rise in the temperature for the two models. This trend has been observed for similar polyester systems reported in the literature. The dispersion of the clay layers in the PBT nanocomposites has been characterized with wide‐angle X‐ray diffraction and transmission electron microscopy. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1344–1353, 2007