bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tyrosine hydroxylase deficiency: Clinical manifestations of catecholamine insufficiency in infancy
Authors: Grattan‐Smith Padraic J. , Wevers Ron A. , Steenbergen‐Spanjers Gerry C. , Fung Victor S.C. , Earl John , Wilcken Bridget 
Published: August 2002

AbstractInborn errors of catecholamine biosynthesis are rare but of great interest as they are genetic disorders, and in some, treatment may completely reverse severe neurological abnormalities. They also provide insights into the action of the biogenic amines in the developing brain. We describe the clinical course of an infant with tyrosine hydroxylase (TOH) deficiency over a 30‐month period. The parents are consanguineous, and genetic analysis revealed the infant to be homozygous for the common G698A mutation in the TOH gene. TOH deficiency can be seen as a model of pure catecholamine deficiency. Experimental evidence, reports of other disorders of biogenic amines, and our experience with this infant suggest that the symptoms of catecholamine deficiency in infancy can be broadly subdivided. Signs of dopamine deficiency include tremor, hypersensitivity to levadopa (L‐dopa) therapy, oculogyric crises, akinesia, rigidity, and dystonia. Manifestations of norepinephrine deficiency include ptosis, miosis, profuse oropharyngeal secretions, and postural hypotension. Hypersensitivity to L‐dopa was a particular management problem in this infant. © 2002 Movement Disorder Society.
Bereitschaftspotential in depressed and non‐depressed patients with Parkinson's disease
Authors: Filipović Saša R. , Šternić Nadežda , Svetel Marina , Dragašević Nataša , Lečic Dušica , Kostić Vladimir S. 
Published: August 2002

AbstractImpaired initiation and slowed execution of movements are two of the principal characteristics of Parkinson's disease (PD). A similar pattern of movement impairments (psychomotor retardation) can be seen frequently in patients with idiopathic depression. In addition, affective disorders have been frequently reported in patients with different basal ganglia disorders. The aim of this study was to determine whether there are some particularities in the cerebral electrical activity during the preparation and execution of voluntary internally paced movements (i.e., Bereitschaftspotential, BP) in depressed PD patients, which can distinguish them from non‐depressed PD patients, as well as from healthy controls. The BPs were recorded in 16 patients with idiopathic PD, eight of whom were depressed (PD‐D), and eight of whom were not (PD‐ND). Additional recordings were taken from a group of eight age‐ and sex‐matched healthy subjects. Depression was classified using the Research Diagnostic Criteria and the two PD groups were matched for age, disease severity, and disease duration. The amplitudes and slopes of the BPs from PD patients were generally smaller than in controls, but there was no specific pattern of BP changes that distinguished depressed from non‐depressed PD patients. In addition, there was no particular association between measures of depression severity and BP parameters. The data suggest that presence of depression in PD might not have any additional deteriorating influence on already impaired preparation for self‐paced spontaneous movements. © 2001 Movement Disorder Society.
Neuroprostheses for the upper extremity
Authors: Keith Michael W. 
Published: August 2002

AbstractFunctional electrical stimulation (FES) neuroprostheses can be used to replace lost motor and sensory function in persons with neurological disorders. FES technology has subsequently been shown effective and safe in restoring hand function in adults with spinal cord injury. The freehand system consists of an implanted receiver‐stimulator, an external shoulder position sensor, and an external control unit. Commands are originated by voluntary movement of the contralateral shoulder and are measured by the sensor. There are several types of electrodes: epimysial, intramuscular, nerve cuff, and intraneural. Neuroprostheses are recommended within the context of all available reconstructive options for the upper limbs. Voluntary tendon transfers are the first choice. The clinical outcomes as measured by improvement on scales of impairment, activities of daily living, and satisfaction are rewarding. The next step in improvement of the motor function of person with spinal cord injury will be the addition of a controllable second upper extremity and the elimination of additional external hardware. © 2001 Wiley‐Liss, Inc. MICROSURGERY 21:256‐263 2001
Generation of far‐infrared radiation in a frozen‐wave photoswitched semiconductor structure
Authors: Scherbatko Igor V. , Nerukh Alexander G. 
Published: August 2002

AbstractThe generation of radiation in the far‐infrared (FIR) range by the interaction of a moving photoconducting front with an electrostatic “frozen‐wave” configuration in a semiconductor is considered. Numerical simulations of FIR generation are discussed using the estimations of semiconductor layer parameters. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 277–282, 2001.
Wideband dual‐frequency stacked microstrip patch antenna
Authors: de Haaij D. M. , Joubert J. , Odendaal W. 
Published: August 2002

AbstractResults for a stacked microstrip patch antenna for dual‐band applications are presented. The aim is to cover the frequency bands 890–960 MHz and 1.71–1.88 GHz, respectively. Impedance bandwidths (VSWR <2 : 1) of 20.1 and 14.8% were obtained for the respective frequency bands. Simulated as well as measured results for the antenna are presented. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 289–292, 2001.
Equivalent transmission‐line model for optically controlled microstrip slow‐wave structures
Authors: Bhadauria Avanish , Sharma Enakshi Khular , Verma Anand K. 
Published: August 2002

AbstractThis paper presents equivalent transmission‐line circuit models for an optically controlled microstrip slow‐wave MIS structure which are valid over all regions of operation, namely, lossy dielectric, slow wave, and skin effect. The models take into account both capacitance and inductance due to the skin effect. The results for the phase constant (slowing factor) and attenuation by the equivalent‐circuit models compare well with those obtained by an exact wave analysis. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 292–298, 2001.
Analytical evaluation of optical system impairments caused by high‐order polarization‐mode dispersion effects
Authors: Orlandini Alessandra , Vincetti Luca 
Published: August 2002

AbstractThe differential equation that relates the Jones matrix of a polarization‐mode dispersion fiber to its output dispersion vector is solved for a dispersion vector that moves on a circumference in the Stokes space. It yields a new simple model that can be usefully exploited to calculate the pulse‐broadening analytical expression and to evaluate the system performance in terms of outage probability. A comparison among the results obtained with it, with other models proposed in literature, and with the numerical DRW model show its best accuracy. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 449–453, 2001.
Calculation of radio loss in forest environments by an empirical formula
Authors: Chen Hsing‐Yi , Kuo Yu‐Yui 
Published: August 2002

AbstractThis paper focuses on the calculation of radio loss in forest environments. In the study, an optimum four‐layered forest model is proposed for the calculation of radio loss in forest environments. This optimum four‐layered forest model is obtained by modifying a commonly used model consisting of homogeneous and isotropic dielectric layers placed over a conducting flat earth. The dielectric constant of tree trunks is obtained from published papers, and the equivalent dielectric constant of the tree canopy is calculated with the equivalent dielectric constant technique. After comparing the numerical results with those obtained from measurement data, it is found that there is good agreement between the numerical results and the measurement data. Based on the numerical results, an empirical formula is developed by using the least square curve‐fitting method. This empirical formula is suitable for the calculations of radio loss in forest environments in a frequency range of 1–100 GHz. This formula also provides a simple, fast, accurate, and inexpensive method for calculating the radio loss in forest environments. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 474–480, 2001.
Reflection‐suppressing technique for nonresonant microwave probing
Authors: Soukhov Andrei V. , Jung Sun‐Shin , Park Gun‐Sik 
Published: August 2002

AbstractThe interference decoys produced by the reflections in the nonresonant microwave probing of material properties is suppressed by using the measured S‐parameters for the sensor with and without the test material. Experimental verification showed a very effective suppression of decoys, even when the sensor's voltage standing‐wave ratio exceeded 7. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 287–290, 2002.
Direction‐of‐arrival (DOA) estimation using a single snapshot of voltages induced in a real array operating in any environment
Authors: Kim Kyungjung , Sarkar Tapan K. 
Published: August 2002

AbstractThis paper investigates an electromagnetic preprocessing technique that transforms the voltages that are induced in a nonuniformly spaced array containing real antenna elements to a set of voltages that will be produced in a uniform linear virtual array (ULVA) containing omnidirectional isotropic point radiators. The objective here is that, in the processing methodology, we would like to include various electromagnetic effects like mutual coupling between the antenna elements, the presence of near‐field scatterers, and the platform effects on which the antenna array is mounted. The preprocessing is carried out using a least squares method, which generates a transformation matrix for the set of induced voltages in the real array. This transformation matrix, when applied to the actual measured voltages, yields an equivalent set of voltages that will be induced in the ULVA. Then, a direct data domain superresolution technique like the matrix pencil method is applied to the processed voltages to yield the DOA for the various signals of interest. Numerical results are presented to illustrate the efficiency and accuracy of this method. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 335–340, 2002.
Application of PBG microstrip circuits for enhancing the performance of high‐density substrate patch antennas
Authors: Andrenko Andrey S. , Ikeda Yukio , Ishida Osami 
Published: August 2002

AbstractWe present EM simulation results of a high‐density substrate patch antenna integrated with a microstrip photonic bandgap (PBG) circuit. It is demonstrated that application of such a circuit in an active integrated antenna eliminates undesired high‐order frequency harmonics and patch radiation modes, and improves the return‐loss level at the fundamental‐mode frequency of the patch. Optimization of the PBG periodic element geometry provides harmonics filtering in a wide frequency band. The surface current density on the microstrip PBG circuit integrated antenna has been calculated in illustrating the mechanism of the high‐order radiation harmonics tuning. It is noted that making use of a high‐density dielectric substrate allows easy integration of antenna elements and MMIC circuitry for novel active integrated transmitter front ends. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 340–344, 2002.
Analysis of one‐dimensional photonic bandgap structures with pseudonoise organization of layers in the primitive periodic cell
Authors: Hattori Haroldo T. , Cazo Rogério M. , Barbosa Carmem L. 
Published: August 2002

AbstractIn this paper, we analyze finite one‐dimensional photonic crystals in which the layers in the primitive cell follow a pseudonoise sequence pattern. In this analysis, the layers are composed of two different materials, but the organization of the layers in the primitive cell is varied. The focus of this paper is to analyze how the reflectivity spectrum is affected by different combinations of layers. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 370–373, 2002.
Modified Goell method for the calculation of uniaxial anisotropic rectangular dielectric waveguides
Authors: Dudorov Sergey N. , Lioubtchenko Dmitri V. , Mallat Juha A. , Räisänen Antti V. 
Published: August 2002

AbstractThe Goell method for the calculation of the propagation constant of rectangular dielectric rod waveguides has been modified for a uniaxial anisotropic dielectric material. Experimental results for an anisotropic sapphire waveguide show good agreement with those calculated by our approach. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 373–376, 2002.
Design of a tapered impedance‐matching line using inverse scattering
Authors: Song Choongho , Lee Sangseol 
Published: August 2002

AbstractA new design method for a tapered impedance‐matching line is proposed. The accurate characteristic impedance profile of the desired matching line is obtained through the accurate profile inversion of a virtual dielectric medium which is equivalent to the matching line in view of the reflection characteristic. Then, the matching line is synthesized according to the characteristic impedance profile. The method can be applied to design impedance‐matching lines with arbitrary passband characteristics without any equivalent‐circuit analysis. In this method, the inevitable errors in the method using the time‐domain reflection coefficient can be avoided by using the frequency‐domain reflection coefficient. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 393–396, 2002.
Microstrip lines on annular‐ring photonic bandgap structures
Authors: Karmakar Nemai C. , Mollah Mohammad N. 
Published: August 2002

AbstractWith the advent of planar photonic bandgap (PBG) materials, different topologies of PBG structures have been proposed to improve the bandgap performances of microwave signals. Conventional circular‐patterned PBGs have constraints in the broadband stopband performance due to the high ripple heights inS‐parameters. In this paper, we suggest a novel annular‐ring‐patterned PBG to improve the stopband bandwidth and the ripples. The aspect ratio of the annular‐ring‐patterned PBG plays an important role in controlling the bandwidth of the rejection band, as well as the ripple heights in theS‐parameters of the PBG‐engineered transmission lines. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 32: 431–433, 2002.
The Cramer‐Rao bound for the estimation of angles of arrival in on‐board array antennas
Authors: Castro I. T. , Landesa L. , Taboada J. M. , Obelleiro F. 
Published: August 2002

AbstractArray antennas mounted on aircraft, ships, or any other complex platform suffer from mutual coupling and coupling with the platform in the transmission or reception of electromagnetic waves. These coupling effects affect the estimation of the direction of arrival (DOA) of plane waves performed with on‐board antennas. With the use of the method of moments (MoM) to model these electromagnetic (EM) coupling terms, closed‐matrix expressions for the Cramer–Rao bound (CRB) are obtained for on‐board array antennas considering both mutual coupling and platform coupling effects. Some significant differences in the CRB have been found when this bound is compared with the same bound calculated in an ideal free coupling environment. Numerical results are shown to illustrate these effects. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 119–123, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10249
Integrated F‐shaped monopole antenna for 2.4/5.2 GHz dual‐band operation
Authors: Yeh Shih‐Huang , Wong Kin‐Lu 
Published: August 2002

AbstractA novel dual‐band F‐shaped monopole antenna is proposed. The antenna comprises a vertical metal line and two (one upper and one lower) horizontal metal lines of different lengths, which are used for tuning the antenna's first two resonant frequencies to achieve desired dual‐band operation. The proposed antenna is very suitable to be printed on a microwave substrate and can be easily integrated with the associated circuitry on the same substrate. A constructed prototype suitable for wireless LAN applications in the 2.4‐ and 5.2‐GHz bands is demonstrated. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 34: 24–26, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10362
Direction‐of‐arrival statistics of urban propagation channel at 1.9 GHz based on measurement and ray tracing
Authors: Su Tao , Ling Hao , Foltz Heinrich 
Published: August 2002

AbstractThe statistics of direction of arrival (DOA) in an urban environment are generated based on measurement and ray tracing simulation. The angular power distributions at different locations of the city are fit into the Gaussian angle‐of‐arrival model. The following four quantities are then extracted as model parameters: The number of incoming DOA, the normalized amplitude of each incoming signal, the mean direction of the incoming signals, and the standard deviation of the incoming signals about the mean direction. It is shown that the statistics of the above four quantities resulting from the simulation are in good agreement with those from the measurement data. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 34: 31–35, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10364
A novel active array antenna using a transmission‐line coupling network and a voltage‐controlled oscillator with a varactor diode
Authors: Seo Chulhun , Kim Minseok 
Published: August 2002

AbstractIn this paper, a 1×4 active phased‐array antenna is designed using a voltage‐controlled oscillator (VCO) with a varactor diode and a transmission‐line network. The varactor diode was connected in parallel to the FET for the wide tuning range of the VCO, and the transmission‐line network was composed of the transmission line,the open stub, and the chip resistor. The scan range, −20 to 22° at 2.44 GHz, was controlled by the applied varactor diode voltage and the transmission‐line coupling network. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 148–150, 2001.
Broadband tunable (Cr–Cu–Au) resonator using ferrite substrate
Authors: Srivastava G. P. , Dubey Ashish , Tyagi G. S. 
Published: August 2002

AbstractAn X‐band, end‐coupled ring resonator has been fabricated photolithographically by depositing Cr–Cu–Au film on an LiZnTi polycrystalline ferrite substrate. Resonator characteristics have been studied by keeping it in the magnetic field, which was varied from 0 to 3.0 kG. Broadband tunability of 3.1 GHz was achieved with a minimum insertion loss of −11.17 dB when the direction of the magnetic field was changed from transverse to longitudinal to the wave propagation in coupling lines. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 161–163, 2001.
Low‐bias BAR‐mode HEAP transmitting antennas
Authors: González V. , Rodríguez J. M. , Rueda C. , Segovia D. , Rajo E. , Martin Pascual C. 
Published: August 2002

AbstractThis paper describes the design and construction of a BAR‐mode high‐efficiency active transmitting patch antenna (HEAP). The dimensions, shape, and location of the feeding point in the antenna are chosen to obtain an input impedance so the transistor works in the BAR mode at 1650 MHz with high collector efficiency and low bias voltage. A HEAP antenna with an efficiency of about 60%, Vcc=3 V, and EIRP=2.5 W has been developed. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 163–167, 2001.
Indoor radio‐wave propagation modeling by multilevel fast multipole algorithm
Authors: Lu C. C. 
Published: August 2002

AbstractThree‐dimensional indoor radio‐wave propagation is accurately modeled by solving the volume electric‐field integral equation (VEFIE). The integral equation is discretized by the method of moments (MoM), in which the building walls, ceilings, floors, as well as any internal obstacles are represented by a collection of small volumetric cells. This discretization is capable of modeling a 3‐D room structure to fine details. The solution to the MoM matrix equation is facilitated by the multilevel fast multipole algorithm (MLFMA), which significantly reduces memory requirements and CPU time. Numerical examples are shown to demonstrate the accuracy of the solution and the capability of modeling dielectric structures of nearly realistic sizes. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 168–175, 2001.
Multilayered chiral filter response at oblique incidence
Authors: Cory Haim , Rosenhouse Isaac 
Published: August 2002

AbstractThe response of multilayered chiral filters is investigated at oblique incidence. It is found that there is a slight degradation with respect to the same filter operating at normal incidence. A possible application is proposed for this device: a reflector or a subreflector fed at two different frequencies by two feeds situated on each side of a multilayered chiral filter functioning as a frequency‐selective surface. The response of this device is well behaved, and is similar for TE and TM modes. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 192–195, 2001.
Dual‐frequency rectangular microstrip antenna with double π‐shaped slots
Authors: Chen Hua‐Ming , Sze Jia‐Yi , Lin Yi‐Fang , Kuo Chin‐Chun 
Published: August 2002

AbstractA dual‐frequency rectangular microstrip antenna with a pair of π‐shaped narrow slots close to the nonradiating edges of the patch is experimentally studied. By varying the length and spacing of the two arms of each π‐shaped slot, the proposed antenna provides a tunable frequency ratio from about 1.03 to 1.19. Details of the antenna design and experimental results are presented and discussed. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 195–197, 2001.
Helix wire tolerances in TWT small‐signal gain prediction
Authors: D'agostino Stefano , Paoloni Claudio 
Published: August 2002

AbstractSmall‐signal gain is an important characteristic within the framework of overall traveling‐wave tube (TWT) performance. The fabrication tolerances can determine different performances with respect to the required ones. In this letter, an accurate evaluation of the effect of the helix wire tolerances on the TWT small‐signal gain is proposed. The study is applied to a measured five‐section TWT working in the 10–13 GHz frequency band. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 208–209, 2001.
Stacked shorted microstrip antenna for low cross polarization and wide‐band
Authors: Baligar J. S. , Revankar U. K. , Acharya K. V. 
Published: August 2002

AbstractA novel structure to improve the cross‐polarization characteristics of the shorted square microstrip antenna is presented. The square‐ring patch is used as a parasitic element in the stacked position to tune the input impedance, resonant frequency, cross polarization, and bandwidth of the shorted square microstrip antenna. As a result, 11% bandwidth and better than −14.5 dB cross‐polarization levels have been achieved. The theoretical results are compared with the experimental results. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 73–75, 20.
Optimum compensating susceptance and position for quadrature directional coupler
Authors: Yu Cheng‐Cheh , Chuang Sheng‐Chieh 
Published: August 2002

AbstractThe optimum susceptance and position for compensation of the match and isolation performances of a quadrature directional coupler are perspicuously derived in this paper. Furthermore, various frequency responses of the coupler with either capacitive or inductive loading are given to elucidate the characteristics of a susceptance‐loaded quadrature directional coupler as well. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 90–95, 2001.