bluuebunny/crossref_metadata_2025 huggingface dataset:
High‐resolution imaging of the intracranial arterial and venous systems following a single contrast injection
Authors: Al‐Kwifi Osama , Shelef Ilan , Farb Richard I. , Stainsby Jeffrey , Wright Graham A.
Published: June 2006

Purpose

To generate two separate three‐dimensional (3D) high spatial resolution images of the intracranial arterial and venous systems using a single contrast injection.

Materials and Methods

A 3D contrast‐enhanced (CE) magnetic resonance angiography (MRA) acquisition was modified to create two separate k‐space data sets to encode the arterial and venous enhancement signals individually after contrast agent injection. Following an automated detection of contrast arrival, the central k‐space views corresponding to the arterial phase were acquired for the first eight seconds. A full elliptical‐centric acquisition was then acquired for the venous phase and the missing views in the periphery of the first k‐space data set were copied from the venous phase. A total of 18 patients underwent this study. Image quality, signal‐to‐noise ratio (SNR), and contrast‐to‐noise ratio (CNR) were determined in both intracranial systems.

Results

Two 3D image sets were generated for the arterial and venous intracranial systems. Both sets have high quality images that are clinically diagnostic. SNR and CNR were high in both sets, so that all the major vessels were visible.

Conclusion

This technique provides images with high spatial resolution for both arterial and venous intracranial systems using a single contrast injection. J. Magn. Reson. Imaging 2006;9999:000–000. © 2006 Wiley‐Liss, Inc.
Modulations of VEGF and iNOS in the rat heart by low level laser therapy are associated with cardioprotection and enhanced angiogenesis
Authors: Tuby Hana , Maltz Lidya , Oron Uri
Published: June 2006

Background and Objectives

It has been shown previously that low‐level laser therapy (LLLT) significantly reduces infarct size following induction of myocardial infarction in rats and dogs. The aim of the present study was to investigate the effect of LLLT on the expression of vascular endothelial growth factor (VEGF) and inducible nitric oxide synthase (iNOS).

Study Design and Material and Methods

Myocardial infarction was induced by occlusion of the left descending artery in 87 rats. LLLT was applied to intact and post‐infarction. VEGF, iNOS, and angiogenesis were determined.

Results

Both the laser‐irradiated rat hearts post‐infarction and intact hearts demonstrated a significant increase in VEGF and iNOS expression compared to non‐laser‐irradiated hearts. LLLT also caused a significant elevation in angiogenesis.

Conclusions

It is concluded that VEGF and iNOS expression in the infarcted rat heart is markedly upregulated by LLLT and is associated with enhanced angiogenesis and cardioprotection. Lasers Surg. Med. © 2006 Wiley‐Liss, Inc.
On the Laplacian vector fields theory in domains with rectifiable boundary
Authors: Abreu‐Blaya R. , Bory‐Reyes J. , Shapiro M.
Published: June 2006

Given a domain Ω in ℝ3 with rectifiable boundary, we consider main integral, and some other, theorems for the theory of Laplacian (sometimes called solenoidal and irrotational, or harmonic) vector fields paying a special attention to the problem of decomposing a continuous vector field, with an additional condition, u on the boundary Γof Ω ⊂ ℝ3 into a sum u = u++u− were u± are boundary values of vector fields which are Laplacian in Ω and its complement respectively. Our proofs are based on the intimate relations between Laplacian vector fields theory and quaternionic analysis for the Moisil–Theodorescu operator. Copyright © 2006 John Wiley & Sons, Ltd.
Time and wavelength domain contention resolution in an optical packet routing node
Authors: Olmos J. J. Vegas , Chi N. , Monroy I. Tafur , Koonen A. M. J. , Yu S.
Published: June 2006

We experimentally demonstrate an optical packet routing node with contention resolution in the time and wavelength contention domain. The node comprises an optical buffer and a wavelength converter. Although the experimental results are shown at 10 Gb/s, the bitrate can be increased substantially. Bit‐error rate measurements are shown, sustaining only 3.5 dB power penalty after 10 μs of optical buffering and wavelength conversion over 5 nm wavelength span. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1728–1729, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21745
On the circularly polarized hemi‐ellipsoidal dielectric resonator antenna
Authors: Li Bin , Leung Kwok Wa
Published: June 2006

The circularly polarized cross‐slot‐coupled hemi‐ellipsoidal dielectric resonator antenna (HEDRA) is studied in this letter. Reasonable agreement between simulation and measurement is obtained. A HEDRA is demonstrated, which has a 10‐dB impedance bandwidth (S11 < −10 dB) of 15.4% and a 3‐dB axial ratio bandwidth of 3.9%. The characteristics of the HEDRA are found. In addition, a comparison between the straight‐ and cross‐slot feeds is made in this letter. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1763–1766, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21749
A novel defected ground structure and its application to a lowpass filter
Authors: Li Guo‐Hui , Jiang Xin‐Hua , Zhong Xiao‐Ming
Published: June 2006

A novel defected ground structure (DGS) with two semicircular defected areas is investigated for low pass filter (LPF) applications. An equivalent lumped L‐C circuit model is presented and its corresponding L‐C parameters are also extracted by using parametric relationships. With this structure, the effect of the defected parameters on performance is detailed. Based on the equivalent circuit model, a 3‐pole LPF, using 2 DGS units, is optimally designed and implemented. The results from experiments confirm that the designed LPF can provide a very wide stop band, which is approximately 3.7 times of the cutoff frequency. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1760–1763, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21750
Semi‐analytical computation and 3D modeling of the microwave photo‐induced load in CPW technology
Authors: Gary René , Arnould Jean‐Daniel , Vilcot Anne
Published: June 2006

To be faster and more precise than the numerical technique for the computation of the photo‐induced plasma in semiconductor, an analytical solution has to be developed. In this article, the Hankel transform is used to simplify the solution of the differential equation of second order with nonsconstant coefficient, known as the diffusion equations. The resulting expression of the 3D carrier density includes all the physical parameters of the substrate and the laser beam as well. A parametric study was also feasible using the developed expressions. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1718–1721, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21754
The SSOR‐preconditioned inner outer flexible GMRES method for the FEM analysis of EM problems
Authors: Ping X. W. , Chen R. S. , Tsang K. F. , Yung Edward K.N.
Published: June 2006

When solving electromagnetic problems by finite element method, the resulting linear systems are ill‐conditioned when the PML absorbing layers are adopted. Traditional Krylov iterative algorithms usually converge slowly or may even stagnate. In this paper, the combination of the inner–outer Flexible Generalized Minimum Residual Method (GMRES) and the symmetric successive overrelaxation (SSOR) preconditioning scheme is used to accelerate the iteration for solving a large sparse system of linear equations resulting from the analysis of EM problems by use of edge‐based finite element method (FEM). The numerical results show that tens of times convergence improvement can be achieved compared with the conventional GMRES solver. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1708–1712, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21758
Study of an L‐shaped EMC chip antenna for UMTS operation in a PDA phone with the user's hand
Authors: Lin Chun‐I , Wong Kin‐Lu , Yeh Shih‐Huang , Tang Chia‐Lun
Published: June 2006

A new L‐shaped foam‐base chip antenna having an electromagnetic compatibility property for UMTS operation is presented. With the L‐shaped structure, the proposed chip antenna is very suitable to be placed at the corner of the system ground plane of a mobile phone or PDA phone. With the electromagnetic compatibility property, the antenna can be placed close to or in direct contact with the possible nearby conducting elements, with negligible effects on the antenna performances. The proposed L‐shaped chip antenna can be with various aspect ratios and provide a wide operating bandwidth for UMTS (1920 ∼ 2170 MHz) operation. Further, in this study, the user's hand effects on the performances of the proposed antenna are also analyzed. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1746–1749, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21759
Experimental investigation on chemical sensor based on a multimode fiber Bragg grating
Authors: Sang Xinzhu , Yu Chongxiu , Yan Binbin , Mayteevarunyoo T. , Wang Kuiru , Lu Naiguang
Published: June 2006

A chemical sensor based on a Bragg grating in the multimode fiber has been demonstrated experimentally. Experimental results indicate that the reflection peak of high‐order mode P2 exhibits a much higher concentration sensitivity of the chemical solution than the reflection peak P1 of the high‐order mode. The sensor has been used to measure the concentrations of propylene glycol solutions and sugar solutions, which could detect 0.05% and 0.04% concentration change for them with the wavelength interrogation module of 1‐pm resolution. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1739–1741, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21761
High‐power narrow line width tunable cladding pumped Er:Yb co‐doped fiber laser
Authors: Zhang Shu‐min , Lu Fu‐yun , Wang Jian
Published: June 2006

A narrow line width, tunable, and highly efficient fiber laser based on Er3+/Yb3+ co‐doped double‐clad fiber with the maximum output power of 438 mW and a slope efficiency of ∼16% has been demonstrated. By using a fiber Bragg grating (FBG) as a narrow band reflector, 3‐dB line width of the output laser could be as narrow as 0.04 nm over the whole tuning range, and by compressing or stretching the FBG, wavelength tunable range of 4.0 nm was realized. In the experiment, we also found that there existed an optimum splitting ratio of the output coupler, at which the maximum output power could reach ∼647 mW. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1736–1739, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21762
Design of metamaterial superstrates and substrates for directivity and port isolation enhancement of a dual‐frequency dual‐polarization microstrip antenna
Authors: Lee Dong H. , Lee Young J. , Yeo Junho , Mittra Raj , Park Wee S.
Published: June 2006

In this paper, we propose a novel design for enhancing the directivity and port isolation of a dual‐frequency dual‐polarization (DFDP) microstrip antenna by using metamaterial superstrates and substrates. To enhance the directivity of this without a complex feed network, we first design a strip‐mesh type of Frequency Selective Surface (FSS) type superstrate as a cover for a DFDP antenna, which supports two orthogonal polarizations at two different resonant frequencies. Next, a 2D anisotropic uniplanar compact bandgap type ground plane is introduced to enhance the isolation between the two ports of the DFDP antenna. It is demonstrated that the directivity at two frequency bands is enhanced by about 13 dB in the first band and by ∼12 dB at the second one, when compared with the patch antenna alone. Also, the isolation between the two ports is shown to be −35 dB, which is −15 dB lower than that of a conventional patch antenna. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1873–1876, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21764
Substructuring approach to optimization of matching for photonic crystal waveguides
Authors: Steinberg Ben Z. , Boag Amir , Hershkoviz Orli
Published: June 2006

A substructuring approach for numerical optimization of photonic crystal devices is proposed and demonstrated. Specifically, we consider the matching of coupled cavity waveguides (CCW's)—known also as coupled resonators optical waveguides (CROWs)—to free space. In this approach, one separates a priori between the invariant main structure that consists most of the PhC and the CCW, and the substructure that consists of a small portion of the CCW and evolves along the optimization course. Specific examples of matching configurations with insertion loss as low as few percent are presented. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1866–1871, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21766
On the performance of dichroic mirrors with hexagonal holes
Authors: Besso Piermario , Bozzi Maurizio , Formaggi Marco , Germani Simone , Perregrini Luca
Published: June 2006

This article presents an innovative design of a 45°‐incidence S/X/Ka‐band inductive dichroic mirror, intended for the upgrade of a ground station antenna of the European Space Agency supporting deep‐space missions. The dichroic mirror consists of a thick metal plate perforated periodically with hexagonal holes. The use of hexagonal shapes allows for tightly packing the holes and provides a large number of degrees of freedom. This permits to improve the electrical performance of the dichroic mirror and to increase its mechanical stiffness. To highlight the advantages of this shape, first we report the simulated and measured performance of a dichroic mirror with rectangular holes, with the aim of validating the analysis tool and of providing a comparison for the new design. Afterward, we discuss the design of the new dichroic mirror based on hexagonal holes, and systematically compare the performance obtained in the two cases, namely with rectangular and hexagonal holes. It is shown that the use of the new dichroic mirror with hexagonal holes permits to preserve the radiation pattern of the feed horn and does not significantly increase the cross‐polar level. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1858–1862, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21767
Design of microstrip filter and diplexer with a multiple harmonics suppression for mobile communication
Authors: Chen Yu‐Wei , Ho Min‐Hua
Published: June 2006

A folded hybrid coupled‐line microstrip bandpass filter with multiple harmonics suppression and wide stopband bandwidth is proposed in this research. A simple design rule together with the usage of an over‐ and an under‐coupled structure is adopted in this filter to eliminate the first two spurious responses from using circuit's zeros. Then, the coupled straight lines are transformed to a folded‐line layout to save the circuit space and to tune the third transmission zero for the removal of an extra spurious response. An experiment is conducted for validation and good agreement between simulation and measurement is observed. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1812–1816, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21769
Design of UWB lowpass filter using a novel defected ground structure
Authors: Zhang Fei , Gu Jiangzhong , Shi Lina , Li Chengfang , Sun Xiaowei
Published: June 2006

In this study, firstly, a novel U‐shaped defected ground structure(UDGS) cell is proposed to hold both wide band gap and excellent slow‐wave characteristic. The design, simulation, and fabrication of compact ultra wideband(UWB) low pass filters (LPFs) using two UDGSs and a compensated microstrip line are reported. No open stubs, high impedance lines, and tee‐/cross‐junction are required, which makes the proposed LPFs smaller in size and suitable for high power application. Investigations on the slow‐wave effects and scattering/radiation levels for a microstrip with the UDGS are also included. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1805–1807, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21772
Electromagnetic field sensor using Mach‐Zehnder waveguide modulator
Authors: Lee Tsung‐Hsin , Hwang Fu‐Tsai , Shay Wen‐Tron , Lee Ching‐Ting
Published: June 2006

An electromagnetic field sensor linking a LiNbO3electrooptical modulator with a circular antenna was studied. In this sensor, a Mach‐Zehnder electrooptical modulator was used as one of the fundamental building blocks. The frequency response was flat from 50 MHz to 3 GHz. The minimum detectable electromagnetic field intensity is 0.7 mV/m at 50 MHz and 1.2 mV/m at 3 GHz, respectively. © 2006 Wiley Periodicals,Inc.Microwave Opt Technol Lett 48:1897–1899, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21776
A domain decomposition scheme based on equivalence theorem
Authors: Li Mao‐Kun , Chew Weng C. , Jiang Li J.
Published: June 2006

A domain decomposition scheme based on the equivalence theorem and the method of moments is introduced. The unknowns on every subscatterer are transferred to the unknowns on its surrounding equivalent surface. With this scheme, both the number of unknowns and the memory usage are reduced. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1853–1857, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21777
Reduced‐size reconfigurable tri‐band printed antenna with CPW tapered‐feed and shorting post
Authors: Evans J. A. , Ammann M. J.
Published: June 2006

A multiband printed monopole antenna is presented, operating primarily in the 900 MHz, 2.4 GHz bands, and 5 GHz bands. A coplanar waveguide feed arrangement is deployed, simplifying the antenna structure to a single side of a printed substrate material. Despite the small size of the antenna, a lower‐edge frequency of 650 MHz is achieved. An impedance bandwidth of 63% is achieved in the 2.4‐GHz band. The low profile antenna presented is potentially suitable for applications in modern mobile and portable radio systems that require operation over widely separated bands, combining multi‐band operation with small size and low profile. With the application of a shorting post, the antenna has the potential for reconfigurable applications. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1850–1853, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21778
Arrayed‐waveguide‐grating‐based correlator for optical header recognition
Authors: Aljada Muhsen , Alameh Kamal E. , Al‐Begain Khalid
Published: June 2006

We propose an incoherent optical correlator for header recognition in optical packet‐switched networks, employing two arrayed waveguide grating and waveguide delay lines. The operation is demonstrated experimentally for 4‐bit patterns at 2.5 Gb/s. Results show that the proposed optical correlator generates autocorrelation and cross‐correlation signals that can easily be recognized using a simple threshold detector. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1839–1843, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21782
Loss characteristics of silicon substrate with different resistivities
Authors: Yang Ru‐Yuan , Hung Cheng‐Yuan , Su Yan‐Kuin , Weng Min‐Hang , Wu Hung‐Wei
Published: June 2006

In the design of high‐speed and high frequency IC's, the influence of the substrate on the circuit performance must be considered carefully. This work investigates the loss characteristic of silicon substrate with different resistivities and distinguishes theoretically and experimentally the dielectric losses into the intrinsic loss of silicon (tan δD) and the extrinsic substrate leakage loss (tan δL) caused by the finite conductivity of the substrate. The dielectric relaxation (cut off) frequency as a function of silicon substrate resistivity are calculated as considering the conditions of substrate noise isolation and RF passive device design. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1773–1776, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21786
Design of a frequency tripler using a novel bandpass filter for Ku‐band application
Authors: Min Jun‐Ki , Kim Hyun‐Jin , Kim Yong‐Hwan , Yu Hyung‐Soo , Lee Jong‐Chul , Hong Ui‐Seok
Published: June 2006

This study presents a frequency tripler using APDP (anti‐parallel diode pair) in which a new structure of bandpass filter (BPF) with low insertion loss and small size is adopted instead of a conventional coupled line BPF. The tripler using the proposed filter is measured and compared with the one using a conventional coupled line BPF. This BPF shows the insertion loss of less than 0.7 dB within the bandwidth of 16.41–19.23 GHz. The conversion loss of the tripler is about 16.6–18.5 dB with flatness of less than ±1 dB at the fundamental frequency of 5.72–6.28 GHz. The suppression characteristics for the first and fifth harmonic signals at 6.1 GHz are −32.16 and −44.6 dBc, respectively, and its phase noise attenuation is about 9.5 dB at 100 kHz offset. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1770–1773, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21787
Locally‐conformal perfectly matched layer implementation for finite element mesh truncation
Authors: Ozgun Ozlem , Kuzuoglu Mustafa
Published: June 2006

In this article, we introduce the locally conformal perfectly matched layer (PML) technique, which is an easily implementable conformal PML implementation, obtained via complex coordinate transformation, for the purpose of mesh truncation in the finite element method. After deriving the governing equations, we test this technique using electromagnetic scattering problems. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1836–1839, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21788
DC or pulse I(V) measurements to simulate transmission line class E power amplifiers
Authors: Loo‐Yau J. R. , Ascencio‐Ramírez Hugo , Reynoso‐Hernández J. A.
Published: June 2006

In FET I(V) nonlinear modeling, the I(V) experimental data are important because they allow one to determine the initial values of the empirical nonlinear model. Pulsed I(V) are preferred over DC measurements because of dispersion phenomena. However, the simulation of a class E PA using I(V) empirical nonlinear model constructed from DC or pulsed measurements to predicts values of PAE, gain, and efficiency are similar. Although this fact can be predictable or evident, because the transistor works in the region where heating and dispersion effects are small, this has not been experimentally demonstrated yet. Therefore the main purpose of this work is to determine whether pulse or DC I(V) measurements are suitable to develop the nonlinear model in order to predict the main features of a transmission line class E PA as Pout, drain efficiency, and PAE. The simulations using both types of data were compared with two experimental transmission line class E PA, designed at 0.8 and 1.9 GHz. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48:1886–1890, 2006; Published online in Wiley InterScience (www.interscience.wiley.com(. DOI 10.1002/mop.21794
Moment method analysis of rectangular waveguide as near‐field measuring probe
Authors: Paramesha Sri , Chakrabarty Ajay
Published: June 2006

The aperture in an infinite ground plane backed by a rectangular waveguide is used as near‐field probe. The reflection coefficient of the radiator, which is also an open‐end of a rectangular waveguide, is computed and compared with the reflection coefficients, when the probe is at different positions in the near‐field. Computations have also been carried out to find the induced probe voltage, when the probe scanning in transverse plane (planar scanning) is at a distance z1 from the radiator. Good agreement is obtained between measured and MOM results. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1802–1805, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21798
Beam‐squint minimization in series‐slotted waveguide array antennas using double negative materials
Authors: Oh Soon‐Soo , Shafai Lotfollah
Published: June 2006

A 5 × 1 series‐slotted waveguide array antenna partly filled with double positive (DPS) and double negative (DNG) materials is investigated. The DNG material has a negative wave vector and its guided‐wavelength equals that of the DPS material. Two simple straight slotted waveguides, one filled only with the DPS material and the other with both DPS and DNG materials, are designed and studied. It is found that the latter waveguide has repeated voltage standing wave shapes. This unique characteristic is utilized to minimize the beam squinting effect in the series‐fed array antennas. It is shown that in a 5 × 1 array using both DPS and DNG materials, the variation in the direction of its beam and boresight gain are limited to 0.5 ° and 0.8 dB, respectively, within a 10% frequency band. In the corresponding conventional array these parameters were 5 ° beam tilt and 3.3 dB boresight gain loss. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1789–1792, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21800
A dual‐band antenna with coplanar ring and patch
Authors: Chang The Nan , Sun Hsu Hsien
Published: June 2006

In this paper, a coplanar ring and patch antenna for dual‐band operation is presented. The patch is placed inside a rectangular ring. A coupling strip located in between the rectangular ring and the patch is used to excite them through a 50‐Ω coaxial cable. The proposed antenna was built on a two‐layer (FR4 and air) substrate with an area of 28 mm by 28 mm designed for WLAN in 2.4‐ and 5.2‐GHz bands. The size of the conducting ground plane is 65 mm by 65 mm. It has a gain of about 5 dBi for both frequencies. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1785–1789, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21801
Simple analysis of wide annular slot antennas
Authors: Kucharski Andrzej A.
Published: June 2006

A simple moment method solution to analyze so‐called annular slot antennas positioned at the interface between two homogeneous half‐spaces is given. The formulation takes into account radial magnetic currents and enables easy analysis of slots that are not necessarily narrow. The generalization into more challenging case of multilayered environment is straightforward. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1679–1683, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21802
Multiband antenna using a half‐wavelength loaded line structure for mobile handheld systems
Authors: Jung Byungwoon , Shin Hoo , Harackiewicz Frances J. , Park Myun‐Joo , Lee Byungje
Published: June 2006

A novel multiband internal antenna is proposed, which can be applied for GSM(880–960 MHz), GPS(1575.42 MHz), DCS(1710–1880 MHz), PCS(1850–1990 MHz), and WCDMA(1920–2170 MHz) band mobile handheld systems, by using a half‐wavelength loaded line structure (HWLLS). The proposed antenna is a combined structure of HWLLS and a shorted monopole. A gap is cut between the antenna shorting pad and the PCB ground plane of system. Then this gap is connected by a chip inductor in order to easily control the upper frequency bands, DCS, PCS, and WCDMA without degradation of resonant characteristics in the lower bands, GSM and GPS. Simulation and experimental results show that the proposed antenna provides enough effective bandwidth (VSWR <2.5) to cover all five bands with the peak gain variation of less than 0.53 dB with varying the chip inductance of less than 3.3 nH. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1683–1687, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21803
Development of ultra wideband planar stepped‐fat dipole antenna
Authors: Park Young‐Jin , Song Jong‐Hwa
Published: June 2006

An ultra wideband (UWB) planar stepped‐fat dipole antenna is developed. The antenna consists of two stepped‐fat arms used for improving the bandwidth of a fat dipole antenna using only two square arms. A prototype antenna is designed and fabricated for high‐resolution UWB image radars. For verification of the performance, reflection coefficient and radiation patterns are measured. Also, the impulse response of the antenna is obtained. It is shown that return loss of the antenna between 0.5 and 2.7 GHz is better than 10 dB. From the impulse response, ringing and dispersion are observed. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1698–1701, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21806
Micromachined interdigital filter on silicon
Authors: Thomson Neil , Hong Jia‐Sheng
Published: June 2006

This article presents a microwave interdigital filter manufactured on high resistive silicon substrate. Two filter designs are referenced in this article; both filters are five pole interdigital filters with one using uniform impedance resonators and the other using stepped impedance resonators. The fabrication of the filters on silicon has been possible with the use of micromachining. This therefore enables filters to be manufactured with smaller footprints and gives rise to further development with micro‐electro‐mechanical systems technology. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1862–1866, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21810
Substituent effects on 15N and 13C NMR chemical shifts of 3‐phenylisoxazoles: a theoretical and spectroscopic study
Authors: Schofield Mark H. , Sorel Marie‐Adele , Manalansan Ryan J. , Richardson David P. , Markgraf J. Hodge
Published: June 2006

The synthesis and assignment of 15N and 13C NMR signals of the isoxazole ring in a series of para‐substituted 3‐phenyl derivatives are reported. DFT calculations of 15N and 13C chemical shifts are presented and compared to observed values. Substituent effects are interpreted in terms of the Hammett correlation and calculated bond orders. Copyright © 2006 John Wiley & Sons, Ltd.
Hexose‐specificity of hexokinase and ADP‐dependence of pyruvate kinase play important roles in the control of monosaccharide utilization in freshly diluted boar spermatozoa
Authors: Medrano Antonio , García‐Gil Núria , Ramió Laura , Montserrat Rivera Ma. , Fernández‐Novell Josep Ma. , Ramírez Alfredo , Peña Alejandro , Dolors Briz Ma. , Pinart Elisabet , Concha Ilona I. , Bonet Sergi , Rigau Teresa , Rodríguez‐Gil Joan E.
Published: June 2006

Incubation of boar sperm from fresh ejaculates in a minimal medium with 10 mM glucose induced a fast and intense activation of glycolysis, as indicated by the observed increases in the intracellular levels of glucose 6‐phosphate (G 6‐P) and ATP and the rate of formation of extracellular L‐lactate. The effect of glucose was much more intense than that induced by fructose, sorbitol, and mannose. The greater utilization of glucose was related to a much greater sensitivity to hexokinase when compared with the other monosaccharides. Thus, the presence of 0.5 mM glucose induced total hexokinase activity in supernatants from sperm extracts of 1.7 ± 0.1 mIU/mg protein, while the same concentration of both fructose, mannose, and sorbitol induced total hexokinase activity from 0.3 ± 0.1 mIU/mg protein to 0.60 ± 1 mIU/mg protein. Kinetic analysis of the total pyruvate kinase activity indicated that this activity was greatly dependent on the presence of ADP and also showed a great affinity for PEP, with an estimated Km in supernatants of 0.15–0.20 mM. Immunological location of proteins closely related to glycolysis, like GLUT‐3 hexose transporter and hexokinase‐I, indicated that these proteins showed the trend to be distributed around or in the cellular membranes of both head and midpiece in a grouped manner. We conclude that glycolysis is regulated by both the specific availability of a concrete sugar and the internal equilibrium between ATP and ADP levels. Furthermore, localization of proteins involved in the control of monosaccharide uptake and phosphorylation suggests that glycolysis starts at concrete points in the boar‐sperm surface. Mol. Reprod. Dev. 1179–1194, 2006. © 2006 Wiley‐Liss, Inc.
A potential role for triglyceride as an energy source during bovine oocyte maturation and early embryo development
Authors: Ferguson Elizabeth M. , Leese Henry J.
Published: June 2006

The potential role of endogenous triglyceride in bovine oocyte maturation and preimplantation development has been investigated. Bovine immature oocytes were recovered from abattoir‐derived ovaries, matured and fertilised in vitro and the zygotes grown to the blastocyst stage in SOFaaBSA. Methyl palmoxirate (MP) blocks the oxidation of fatty acids by inhibiting mitochondrial carnitine palmitoyltransferase A. The development of zygotes exposed to MP during oocyte maturation, and of zygotes exposed to MP during embryo culture has been assessed in terms of oxygen consumption by oocytes and embryos during a 4–6 hr incubation period in the presence of MP and as blastocyst formation and cell number. Immature oocytes exposed to MP during maturation had reduced capacity to form blastocysts after fertilisation; the same effect was apparent, but to a lesser extent, in zygotes exposed to MP during embryo development. Oxygen consumption values of oocytes and blastocysts in the absence of exogenous substrates were similar to those in control medium containing nutrients. MP‐inhibited oxygen consumption of immature oocytes, mature oocytes, cleavage stages embryos and blastocysts by 64, 45, 12 and 13%, respectively. The data are consistent with a role for triglyceride as a key energy source during bovine oocyte maturation and potentially, during preimplantation embryo development. Mol. Reprod. Dev. 1195–1201, 2006. © 2006 Wiley‐Liss, Inc.
Suppression of endogenous estrogen during development affects porcine epididymal sperm maturation
Authors: McCarthy Megan J. , At‐Taras Eeman E. , Pearl Christopher A. , Nitta‐Oda Barbara S. , Roser Janet F. , Conley Alan J. , Berger Trish
Published: June 2006

Estrogen plays an important role in male reproduction, critical for sustained fertility in some species. Reducing estrogen's interaction with its receptor(s) in monkey and mouse models is associated with reduced sperm motility and, in some cases, documented elimination of sperm fertilizing ability, suggesting that normal epididymal function may be estrogen dependent. The objective of these experiments was to evaluate the effects of reduced endogenous estrogen on development of epididymal function in the pig, a species in which males have very high levels of endogenous estrogen. Letrozole, a potent inhibitor of estrogen synthesis, was administered to neonatal boars from 1 week of age and markedly suppressed estrogen production. Epididymal function assessed as acquisition of sperm fertilizing ability (in vitro fertilization of zona‐free oocytes) was reduced in Letrozole‐treated animals at 24 and 28 weeks of age (23% and 30% fertilization, respectively compared with 37% and 54% in vehicle controls) but had recovered by 32 weeks of age. Cauda epididymal sperm numbers were reduced in treated animals (35% of control values at 20 weeks of age) but appeared to be recovering at 32 weeks of age. Reduction of endogenous estrogen had no effect on other aspects of epididymal function (percentage of motile sperm, sperm motion parameters, sperm head morphometrics, or ability of sperm to undergo an acrosome reaction). Reducing endogenous estrogen during postnatal development appears to have transient effects on porcine epididymal function. These transient effects suggest that the pig, with its high endogenous estrogen, may respond differently than other species to reduced estrogen synthesis. Mol. Reprod. Dev. 1122–1128, 2006. © 2006 Wiley‐Liss, Inc.
Expression of genes associated with allantois emergence in ovine and bovine conceptuses
Authors: Ledgard A.M. , Lee R.S‐F. , Peterson A.J.
Published: June 2006

In the development of ruminant embryos, the emergence and growth of the allantois is critical for the establishment of the chorioallantoic placenta. The allantoic membrane contributes to all the vasculature that perfuses the placental tissues and the fetal membranes. Using suppressive subtractive hybridization to compare mRNA from Day 13 ovine preimplantation conceptuses (prior to allantoic emergence) with Day 17 allantoic membrane, we identified nine genes whose expression was associated with the emergence of the allantoic sac. Collagen alpha 1 type XII, collagen alpha 2 type I, collagen alpha 2 type V, epsilon 4 beta‐globin, osteonectin, and uroplakin were expressed at significantly greater levels in ovine Day 17 allantois compared to Day 13 conceptuses. These genes are associated with the extracellular matrix and most likely are involved in establishing and strengthening the structural integrity of the allantoic sac and in the development of the blood vessels. RalB expression increased with development although at significantly greater levels in the allantois only at Day 19. Hoxa‐10 and RhoA showed no differential expression during this period. All these genes showed a similar temporal pattern of expression in bovine conceptuses at equivalent stages of development with significantly greater expression of all these genes, except for Hoxa‐10, found in Day 24 allantois compared to Day 14 conceptuses. This suggests that the role they play in allantoic emergence, growth and function is conserved in both ruminant species and that their expression is regulated in a similar manner. The interactions and regulation of this process remains to be fully explained. Mol. Reprod. Dev. 1084–1093, 2006. © 2006 Wiley‐Liss, Inc.
Partial field‐of‐view spiral phase‐contrast imaging using complex difference processing
Authors: Nezafat Reza , Thompson Richard B. , Derbyshire J. Andrew , McVeigh Elliot R.
Published: June 2006

Rapid flow imaging was achieved with a partial field of view (pFOV) spiral motion‐encoded technique. The FOV and the acquisition time were reduced by a factor of 2 by undersampling k‐space. The pFOV spiral k‐space trajectory aliased signals from outside a circular ring whose radius was inversely proportional to the distance between adjacent spirals in k‐space. In this study the FOV was adjusted so that all of the moving spins were located inside the inner half circle of the full FOV. Complex subtraction of two differentially flow‐encoded images was used to remove the spurious phase sources and provide an accurate measurement of flow. The complex subtraction process also serves to eliminate aliasing artifacts that are generated by static tissue from outside the reduced FOV. Experiments in a flow phantom and volunteers showed that the flow estimates obtained by pFOV spiral motion encoding are in good agreement with the estimates reconstructed using complex difference processing. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Effect of the potassium channel opener WAY‐133537 on the overactive bladder of spinalized rats
Authors: Elzayat Ehab , Khaled Sabri , Kashiwabara Takeshi , Elhilali Mostafa , Corcos Jacques
Published: June 2006

Aims

To test the efficacy of WAY‐133537 for the treatment of overactive bladder (OAB) in a chronic paraplegic rat model.

Materials and Methods

Forty‐eight female Sprague–Dawley rats were used in this study. Six animals served as normal controls (without spinal cord transaction (ST)), while 42 rats underwent ST at the 10th thoracic vertebra. Two weeks after ST, cystometrogram (CMG) was performed in six randomly chosen animals to ensure the development of neurogenic detrusor overactivity. The remaining 36 rats were divided into three equal groups, 12 received the vehicle as “paraplegic controls,” 12 received WAY‐133537 0.3 mg/kg, and 12 received WAY‐133537 3 mg/kg. Each “paraplegic control” and treatment group was further divided into two sub‐groups (n = 6), with CMG at 3 and 4 weeks after ST, respectively.

Results

Two weeks after ST, all “vehicle control” rats developed detrusor overactivity with a mean frequency of 0.96 and 1.48 contractions/min and amplitude of 22.96 and 31.22 cm H2O with 1‐ and 2‐week treatment, respectively. Neurogenic detrusor overactivity disappeared from 50% of rats that received WAY‐133537 0.3 mg/kg for 1 week, and frequency decreased to 0.41 contractions/min. After 2 weeks of treatment, detrusor overactivity vanished from 67% of the animals with even further reduction in the frequency of detrusor overactivity (0.22 contractions/min,P < 0.01). In rats that received 3 mg/kg of the drug for 1 week, detrusor overactivity disappeared from only one animal with a non‐significant decline in frequency. Fifty percent of rats given WAY‐133537 at the dose of 3 mg/kg/day for 2 weeks manifested no detrusor overactivity.

Conclusions

WAY‐133537 shows efficacy in increasing bladder capacity and reducing the frequency of spontaneous bladder contractions after ST in rats without decreasing voiding pressure. Neurourol. Urodynam. 25:808–814, 2006. © 2006 Wiley‐Liss, Inc.
State‐space partition techniques for multiterminal flows in stochastic networks
Authors: Daly Matthew S. , Alexopoulos Christos
Published: June 2006

This article develops state‐space partition methods for computing performance measures for stochastic networks with demands between multiple pairs of nodes. The chief concern is the evaluation of the probability that there exist separate, noninteracting flows that satisfy all demands. This relates to the multiterminal maximum flow problem discussed in the classic article of Gomory and Hu. The network arcs are assumed to have independent, discrete random capacities. We refer to the probability that all demands can be satisfied as the network reliability (with the understanding that its definition is application dependent). In addition, we also consider the calculation of secondary measures, such as the probability that a particular subset of demands can be met, and the probability that a particular arc lies on a minimum cut. The evaluation of each of these probabilities is shown to be NP‐hard. The proposed methods are based on an iterative partition of the system state space, with each iteration tightening the bounds on the measure of interest. This last property allows the design of increasingly efficient Monte Carlo sampling plans that yield substantially more precise estimators than the standard Monte Carlo method that draws samples from the original capacity distribution. © 2006 Wiley Periodicals, Inc. NETWORKS, Vol. 48(2), 90–111 2006
Studies on Jacobi–Davidson, Rayleigh quotient iteration, inverse iteration generalized Davidson and Newton updates
Authors: Zhou Yunkai
Published: June 2006

We study Davidson‐type subspace eigensolvers. Correction equations of Jacobi–Davidson and several other schemes are reviewed. New correction equations are derived. A general correction equation is constructed, existing correction equations may be considered as special cases of this general equation. The main theme of this study is to identify the essential common ingredient that leads to the efficiency of a diverse form of Davidson‐type methods. We emphasize the importance of the approximate Rayleigh‐quotient‐iteration direction. Copyright © 2006 John Wiley & Sons, Ltd.
Films of chitosan and N‐carboxymethylchitosan. Part II: effect of plasticizers on their physiochemical properties
Authors: Lamim Roberta , de Freitas Rilton Alves , Rudek Elimar Ivan , Wilhelm Helena Maria , Cavalcanti Osvaldo Albuquerque , Bresolin Tania Mari Bellé
Published: June 2006

Chitosan (Ch) and N‐carboxymethylchitosan (N‐CMCh) films were prepared by the casting method at concentrations of 1% and 2% of polymer, with or without plasticizer: polyethylene glycol (PEG‐400) and glycerol (G), at 15% (w/w). The influence of composition on mechanical properties, water vapour transmission rate (WVTR), water saturation, and aqueous dissolution of the films was analysed. The thermal stability of the mixture (polymer:plasticizer, 1:1) was evaluated by thermogravimetric analysis (TGA). In general, all the properties were affected by the plasticizers. The plasticized films showed lower strength and a higher percentage of elongation (%E), in the following order: G > PEG‐400 > unplasticized film. The total WVTR increased with Ch concentration, with a different WVTR profile for Ch and N‐CMCh. While the PEG‐400 addition did not significantly modify the WVTR profile of films, the glycerol enhanced the transport of water vapour through both polymers. The plasticizer addition increased the time of water film saturation, in the following order: G > PEG‐400 > unplasticized film; this was more pronounced in the N‐CMCh films, probably due to the formation of hydrogen bonds. The solubility of the films was also affected by their composition. Copyright © 2006 Society of Chemical Industry
Preparation and properties of ternary polyimide/SiO2/polydiphenylsiloxane composite films
Authors: Shang Zhenping , Lü Changli , Gao Lianxun
Published: June 2006

A series of novel ternary polyimide/SiO2/polydiphenylsiloxane (PI/SiO2/PDPhS) composite films were prepared through co‐hydrolysis and condensation between tetramethoxysilane, diphenyldimethoxysilane (DDS) and aminopropyltriethoxysilane‐terminated polyamic acid, using an in situ sol–gel method. The composite films exhibited good optical transparency up to 30 wt% of total content of DDS and SiO2. SEM analysis showed that the PDPhS and SiO2 were well dispersed in the PI matrix without macroscopic separation of the composite films. TGA analysis indicated that the introduction of SiO2 could improve the thermal stability of the composite films. Dynamic mechanical thermal analysis showed that the composite films with low DDS content (5 wt%) had a higher glass transition temperature (Tg) than pure PI matrix. When the content of DDS was above 10 wt%, the Tg of the composite decreased slightly due to the plasticizing effect of flexible PDPhS linkages on the rigid PI chains. The composite films with high SiO2 content exhibited higher values of storage modulus. Tensile measurements also showed that the modulus and tensile strength of the composite films increased with increasing SiO2 content, and the composite films still retained a high elongation at break due the introduction of DDS. The density and water absorption of the composite films were also characterized. Copyright © 2006 Society of Chemical Industry
Effect of side‐chain length of succinic anhydride on coefficient of thermal expansion behavior of epoxy resins
Authors: Jin Fan‐Long , Han Mijeong , Park Soo‐Jin
Published: June 2006

The effect of an alkenyl side‐chain of succinic anhydride (SA) on the thermal behavior and the coefficient of thermal expansion (CTE) of diglycidylether of bisphenol A (DGEBA) epoxy resins was studied. The number of carbons in the side‐chain of SA was varied from 6 to 14 and N,N‐Dimethylbenzylamine was used as an accelerator. As a result, the reactivity of SA with epoxide groups was decreased on increasing the length of the alkenyl side‐chain of SA. The thermal stabilities of cured DGEBA/SA samples were approximately constant with varying alkenyl side‐chain of SA. Also, the CTE of the systems was increased as the length of the alkenyl side‐chain of SA increased. This could be attributed to the increased motion of the chain segments in the epoxy network structure induced by the longer alkenyl side‐chain of SA. The effect of amount anhydride, thermoplastics, and fillers on the CTE of the epoxy resins was also discussed. Copyright © 2006 Society of Chemical Industry