bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bandstop characteristics of microstrip slotted patch without periodic elements
Authors: Görür Adnan , Karpuz Ceyhun , Tezekici B. Sami , Görür Hülya 
Published: October 2002

AbstractA rectangular microstrip slotted patch, which provides the bandgap with different manner of a PBG, is successfully demonstrated with the wideband tuning capability. Both experimental and simulated results confirm that the stopband characteristics can easily be controlled by the slot dimensions, especially by the slot length and the slot position. Moreover, the proposed structure is the simple and compact for MMIC applications. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 125–128, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10535
Surface‐mountable dual side‐feed circularly polarized ceramic chip antenna
Authors: Su Chih‐Ming , Wong Kin‐Lu 
Published: October 2002

AbstractA novel dual side‐feed circularly polarized ceramic chip antenna suitable for surface mounting on a system circuit board is presented. The antenna mainly comprises a square radiating patch, a square ground plane, and two vertical conformal strips for the dual side‐feed, which are printed on the top, bottom and side surfaces of a ceramic chip. For obtaining circular polarization (CP) radiation for global positioning system (GPS) operation at 1575 MHz, a prototype using a square‐disk ceramic chip of dimensions 4 × 17.5 × 17.5 mm3 and relative permittivity 45 was studied, and the experimental results are presented. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 137–138, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10538
An array of stagger‐tuned printed dipoles as a broadband frequency selective surface
Authors: Sarkar D. , Sarkar P. P. , Das S. , Chowdhury S. K. 
Published: October 2002

AbstractIn this paper, the frequency selective property of an array of rectangular dipole microstrip patches resonant at three different frequencies (within the same frequency band) is investigated. Experimental data indicate a prominent band separation between transmission and reflection bands of the F.S.S. in the normalized transmitted electric field vs. frequency plot. Investigation of the F.S.S. of an array of rectangular dipole microstrip patches resonant at a single frequency shows that the bandwidth of the reflection band is very narrow. In our present investigation resonance at triple frequencies within the same frequency band is used to broaden the bandwidth of the reflection band. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 138–140, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10539
A physical approach to generating time frequency distributions of dynamic CEM targets
Authors: Carr M. , Volakis J. L. 
Published: October 2002

AbstractGenerating accurate, high‐resolution time‐frequency distributions (TFD) is a critical aspect of dynamic radar scattering analysis. Well‐formed TFD's can be used for target identification, target acquisition in high‐noise environments, or extending the range of radar systems. In this paper, we diverge from traditional methods employing complex signal‐processing methods and propose a simple approach for constructing the TFD for computational electromagnetic (CEM) targets based on the physics of the problem. The proposed method allows for an arbitrarily high resolution at any single look angle. Several examples are presented to validate the method. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 186–189, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10552
Slotted ground plane for frequency tunable dielectric resonator antenna
Authors: Huang Chih‐Yu 
Published: October 2002

AbstractA technique for effectively tuning the resonant frequency of a microstripline feed dielectric resonator (DR) antenna is demonstrated. By embedding a pair of narrow slots in the antenna's ground plane, the resonant frequency of the DR antenna can be varied by adjusting the embedded slot length. Experimental results of the proposed frequency tunable DR antenna are presented and discussed. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 193–195, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10554
Neural network based time domain modelling of 0.18 μm MOSFETs
Authors: Toner B. , Alam M. S. , Fusco V. F. , Armstrong G. A. 
Published: October 2002

AbstractIn this paper a new time domain based neural network model of a 0.18 μm RF MOSFET will be demonstrated. The model consists of only three intrinsic non‐linear current sources, each being modelled by a neural network derived from large signal time domain voltage/current waveform measurements at the intrinsic device terminals. This approach negates the traditional method of multi‐bias S‐parameter measurement providing a fast and accurate method of modelling the transistor under large signal conditions. Full verification of the model will be provided against an 80 μm/0.18 μm MOSFET operating at 2.4 GHz. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 203–206, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10558
A procedure to design aperture‐coupled stacked‐microstrip antenna based on experiment
Authors: Zhang Yabin , Li Binhong , Liu Yijun 
Published: October 2002

AbstractThe aperture‐coupled stacked‐microstrip antenna (ACSMA) is an important type of broadband microstrip antenna. A simple and practical procedure for its design is presented in this letter. Utilizing the technique, one ACSMA of L‐band has been designed. The experiments have been carried out and the measurement results verified the applicability of the method. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 244–247, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10569
Full‐wave modelling of offset overlap and gap discontinuity for asymmetric strip conductors in multi‐layered MIC environment
Authors: Shukla Rajiv Kumar , Biswas Animesh 
Published: October 2002

AbstractA generalised model for characterising the frequency dependent properties of general offset overlap and gap discontinuity of asymmetric strip conductors in multi‐layered MIC environment is presented in this paper. The transverse resonance technique is applied in transformed domain to extract the equivalent PI‐circuit parameters of the discontinuity. The incorporation of options for offset between the strips and asymmetry in strip widths make the present model very general and useful for different structures in multi‐layered substrate environment. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 247–251, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10570
Transfection of embryonal carcinoma cells at high efficiency using liposome‐mediated transfection
Authors: Nowling Tamara , Desler Michelle , Kuszynski Charles , Rizzino Angie 
Published: October 2002

AbstractEmbryonal carcinoma (EC) cells are recognized as an excellent model system for studying the early stages of mammalian development. Many studies performed with EC cells involve transient transfection with promoter/reporter gene constructs and/or mammalian expression vectors. One of the limitations of working with EC cells is their inability to be transfected at high efficiency. In most cases, EC cells are transfected using the calcium phosphate method. The objective of this study was to identify protocols and culture conditions that significantly increase the transfection efficiency of EC cells. F9 EC cells were used for this purpose, because they are the EC cell line studied most commonly. We show that the transfection efficiency of F9 EC cells using the calcium phosphate method is less than 5%; whereas, their transfection efficiency can be improved ∼15‐fold using optimized culture conditions and liposome‐based transfection reagents. Specifically, we demonstrate that more than 50% of F9 EC cells can be transfected using LipofectAMINE 2000. In addition to higher levels of transfection, there is much less plate‐to‐plate variation with liposome‐based reagents as compared to transfection with calcium phosphate. Interestingly, transfection efficiency using these reagents was found to be inversely related to cell density. This contrasts sharply with the recommendation that transfection with LipofectAMINE 2000 or LipofectAMINE in conjunction with the PLUS reagent be performed at high cell densities. Given the improvements in transfection efficiency reported here, it will now be possible to perform studies with F9 EC cells that require transfection at significantly higher levels than that achieved using the calcium phosphate method. Overall, the highest transfection efficiencies were consistently obtained using LipofectAMINE 2000. Mol. Reprod. Dev. 63: 309–317, 2002. © 2002 Wiley‐Liss, Inc.
Developmental changes in inhibitory effects of arsenic and heat shock on growth of pre‐implantation bovine embryos
Authors: Krininger III C.E. , Stephens S.H. , Hansen P.J. 
Published: October 2002

AbstractAlthough sensitive to various disrupters, pre‐implantation embryos possess some cellular cytoprotective mechanisms that allow continued survival in the face of a deleterious environment. For stresses such as heat shock, embryonic resistance increases as development proceeds. Present objectives were to determine whether (1) arsenic compromises development of pre‐implantation bovine embryos, (2) developmental changes in embryonic resistance to arsenic mimic those seen for resistance to heat shock, and (3) developmental patterns in induction of apoptosis by arsenic are correlated with similar changes in resistance of embryos to inhibitory effects of arsenic on development. Bovine embryos produced by in vitro fertilization were exposed at the two‐cell stage or at day 5 after insemination (embryos ≥ 16‐cells in number) to either sodium arsenite (0, 1, 5, or 10 μM) or heat shock (exposure to 41°C for 0, 3, 4.5, 6, or 9 hr). Arsenic induced apoptosis and increased group 2 caspase activity for embryos at the ≥ 16‐cell stage, but not for embryos at the two‐cell stage. In contrast to these developmental changes in apoptosis responses, exposure to arsenic reduced cell number 24 hr after exposure for both two‐cell embryos and embryos ≥ 16‐cells. Similarly, the percentage of embryos that developed to the blastocyst stage at day 8 after fertilization was reduced by arsenic exposure at both stages of development. Heat shock, conversely, reduced development to the blastocyst stage when applied at the two‐cell stage, but not when applied to embryos ≥ 16‐cells at day 5 after insemination. In conclusion, arsenic can compromise development of bovine pre‐implantation embryos, the temporal window of sensitivity of embryos to arsenic is wider than for heat shock, and cellular cytoprotective responses that embryos acquire for thermal resistance are not sufficient to cause increased embryonic resistance to arsenic exposure. It is likely that despite common cellular pathologies caused by arsenic and heat shock, arsenic acts to reduce development in part through biochemical pathways not activated by heat shock. Moreover, the embryo does not acquire significant resistance to these perturbations within the time frame in development examined. Mol. Reprod. Dev. 63: 335–340, 2002. © 2002 Wiley‐Liss, Inc.
“Soap‐Bubble” visualization and quantitative analysis of 3D coronary magnetic resonance angiograms
Authors: Etienne Alex , Botnar René M. , van Muiswinkel Arianne M.C. , Boesiger Peter , Manning Warren J. , Stuber Matthias 
Published: October 2002

AbstractIn order to compare coronary magnetic resonance angiography (MRA) data obtained with different scanning methodologies, adequate visualization and presentation of the coronary MRA data need to be ensured. Furthermore, an objective quantitative comparison between images acquired with different scanning methods is desirable. To address this need, a software tool (“Soap‐Bubble”) that facilitates visualization and quantitative comparison of 3D volume targeted coronary MRA data was developed. In the present implementation, the user interactively specifies a curved subvolume (enclosed in the 3D coronary MRA data set) that closely encompasses the coronary arterial segments. With a 3D Delaunay triangulation and a parallel projection, this enables the simultaneous display of multiple coronary segments in one 2D representation. For objective quantitative analysis, frequently explored quantitative parameters such as signal‐to‐noise ratio (SNR); contrast‐to‐noise ratio (CNR); and vessel length, sharpness, and diameter can be assessed. The present tool supports visualization and objective, quantitative comparisons of coronary MRA data obtained with different scanning methods. The first results obtained in healthy adults and in patients with coronary artery disease are presented. Magn Reson Med 48:658–666, 2002. © 2002 Wiley‐Liss, Inc.
Fast 31P chemical shift imaging using SSFP methods
Authors: Speck O. , Scheffler K. , Hennig J. 
Published: October 2002

AbstractSteady‐state free precession (SSFP) methods have been very successful due to their high signal and short imaging times. These properties make them good candidates for applications that intrinsically suffer from low signal such as low gamma nuclei imaging. A new chemical shift imaging (CSI) technique based on the SSFP signal formation has been implemented and applied to 31P. The signal properties of the SSFP CSI method have been evaluated and the steady‐state signal of 31P has been measured in human muscles. Due to the T2 and T1 signal dependence of SSFP, the steady‐state signal mainly consists of phosphocreatine (PCr). The technique allows fast CSI acquisitions with high SNR of the PCr signal. The SNR gain for PCr over a FLASH‐based CSI method is approx. 4–5. Fast in vivo CSI of human muscle with subcentimeter resolution and high SNR is demonstrated at 2 T. Magn Reson Med 48:633–639, 2002. © 2002 Wiley‐Liss, Inc.
Somatosensory evoked potentials following stimulation of digital nerves
Authors: Kwast‐Rabben Olga , Libelius Rolf , Heikkilä Hannu 
Published: October 2002

AbstractCortical and spinal somatosensory evoked potentials (SEP) were recorded in healthy individuals following stimulation of digits I, III, and V with an intensity below discomfort level. Peak latency of the earliest cortical negativity (N1) was found to be the most consistent and easily measured parameter, whereas a spinal potential (Cv) was not elicited in all subjects. Descriptive statistics, Student's paired t‐test as well as simple and multiple regression, were used for computer analysis of N1 and Cv peak latencies and central conduction time. The results show a strong correlation between the peak latencies of spinal and cortical potentials and height and arm length of the subjects, with a mild but significant correlation with age. Using multiple regression for N1 and Cv latencies significantly improved the standard deviation. The data may provide reference values for neurophysiological evaluation of patients with cervical spine disorders. © 2002 Wiley Periodicals, Inc. Muscle Nerve 26: 533–538, 2002
Solving generalized transportation problems via pure transportation problems
Authors: Sterbin Gottlieb Elsie 
Published: October 2002

AbstractThis paper investigates certain issues of coefficient sensitivity in generalized network problems when such problems have small gains or losses. In these instances, it might be computationally advantageous to temporarily ignore these gains or losses and solve the resultant “pure” network problem. Subsequently, the optimal solution to the pure problem could be used to derive the optimal solution to the original generalized network problem. In this paper we focus on generalized transportation problems and consider the following question: Given an optimal solution to the pure transportation problem, under what conditions will the optimal solution to the original generalized transportation problem have the same basic variables? We study special cases of the generalized transportation problem in terms of convexity with respect to a basis. For the special case when all gains or losses are identical, we show that convexity holds. We use this result to determine conditions on the magnitude of the gains or losses such that the optimal solutions to both the generalized transportation problem and the associated pure transportation problem have the same basic variables. For more general cases, we establish sufficient conditions for convexity and feasibility. © 2002 Wiley Periodicals, Inc. Naval Research Logistics 49: 666–685, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/nav.10034
GPCG–generalized preconditioned CG method and its use with non‐linear and non‐symmetric displacement decomposition preconditioners
Authors: Blaheta Radim 
Published: October 2002

AbstractThe paper investigates a generalization of the preconditioned conjugate gradient method, which uses explicit orthogonalization of the search directions. This generalized preconditioned conjugate gradient (GPCG) method is suitable for solving the symmetric positive definite systems with preconditioners, which can be non‐symmetric or non‐linear. Such preconditioners can arise from computing of the pseudoresiduals by some additive or multiplicative space decomposition method with inexact solution of the auxiliary subproblems by inner iterations. The non‐linear and non‐symmetric preconditioners based on displacement decomposition for solving elasticity problems are described as an example of such preconditioners. Copyright © 2002 John Wiley & Sons, Ltd.
Relationship between morphology structure and composition of polycaprolactone/Poly(ethylene oxide)/Polylactide copolymeric microspheres
Authors: Li Guangming , Cai Qing , Bei Jianzhong , Wang Shenguo 
Published: October 2002

AbstractA novel tri‐component copolymer, polycaprolactone/poly(ethylene oxide)/polylactide (PCEL) was synthesized. The effect of the chemical composition on physical properties was investigated by using NMR, differential scanning calorimetry (DSC) and X‐ray diffraction. Both the soft segment poly(ethylene oxide) (PEO) and polycaprolactone (PCL) could enhance the mobility of polymer chains and decrease the crystallizability of the copolymers. The polymeric microspheres, which are of interest for drug delivery systems, were prepared using an emulsification‐solvent evaporation technique. By scanning electron microscopy (SEM) and atomic force microscopy (AFM), the surface morphology of the microspheres was studied. It was found that the presence of PEO segment could improve the hydrophilicity of the copolymers and the morphology of the polymeric microspheres could be altered by adjusting the chemical composition. The accumulation of PEO segments on the outer surface of the polymeric microspheres was proven by X‐ray photoelectron spectroscopy (XPS). It had also been proven that the PCL segment could facilitate the movement of PEO segment to the outer surface. Copyright © 2002 John Wiley & Sons, Ltd.
Preparation and characterization of conducting poly(acryloyl chloride)‐g‐ polypyrrole copolymer
Authors: Park Yun Heum , Kim Kwang Won , Jo Won Ho 
Published: October 2002

AbstractThe electroactive copolymer of poly(acryloyl chloride) (PAC) and polypyrrole (PPy) can be synthesized by electrochemical polymerization using a polymer precursor which contains a pyrrole moiety in its side chain. Poly(acryloyl pyrrole) (PAP) was synthesized chemically with acryloyl chloride and potassium pyrrole salt and characterized using FT‐IR and 1H‐NMR spectroscopy. PAP dissolved in dimethyl formamide (DMF), was spin‐coated on a platinum electrode and polymerized electrochemically in the electrolytic mixture solution consisting of acetonitrile, 0.1 M pyrrole, and 0.1 M lithium perchlorate. Constant potential electrolysis showed that pyrrole groups in the precursor were oxidized to form PPy, that is, they acted as grafting centers at which the PPy grew. Scanning electron microscopy (SEM) results and conductivity measurements supported the formation of the graft copolymer. The morphological feature of PAC‐g‐PPy copolymer films showed homogeneous structure, but that of PAC/PPy composite films showed irregular structure. The maximum conductivity of the final products was about 1 S/cm. Copyright © 2002 John Wiley & Sons, Ltd.
The spectrum of review articles published by The Journal of Pathology
Authors: Herrington Simon 
Published: October 2002

AbstractThe Journal of Pathology publishes a variety of types of ‘review’ material. This editorial describes the range of such material and identifies specific categories of contribution, namely editorial, commentary, perspective, and review. The editorial committee would welcome suggestions for topics and authors from the Journal's readership. Copyright © 2002 John Wiley & Sons, Ltd.
Birth defect classification by organ system: a novel approach to heighten teratogenic signalling in a pregnancy registry
Authors: Scheuerle Angela , Tilson Hugh 
Published: October 2002

AbstractThe Antiretroviral Pregnancy Registry (APR) is an ongoing international prospective exposure‐registration cohort study that monitors outcomes of pregnancies exposed to marketed antiretroviral medications. The population of women exposed to antiretrovirals remains relatively small, which limits the power of the registry. In order to maximize identification of a teratogenic signal, a special birth defect classification system was devised. Birth defects were organized based upon organ system and embryology, using the Metropolitan Atlanta Congenital Defects Program as a model. Grouping defects that share embryology and pathogenesis increases the likelihood that a teratogenic effect will be apparent. The result is a three‐tiered system: organ system, preferred defect term, and reported defect term. This system is text based, which eliminates the need to memorize codes and allows use by anyone familiar with medical terminology. Once established, the new APR Organ System Classification retains enough flexibility that categories may be collapsed or expanded as experience grows. Standardized nomenclature also minimizes variation introduced by collecting defect reports from many different sources. Copyright © 2002 John Wiley & Sons, Ltd.