bluuebunny/crossref_metadata_2025 huggingface dataset:
Atmospheric flow indices, regional climate, and Glacier mass balance in the Canadian Rocky mountains
Authors: Shea Joseph M. , Marshall Shawn J.
Published: September 2006

Glacier mass balance is governed by cumulative temperature and precipitation patterns in a region, making it a sensitive indicator of climate variability and trends. Many studies have drawn the link between local meteorological conditions and glacier mass balance, but these statistical relationships are difficult to extrapolate to other sites or to apply in sensitivity studies of future climate change. In this paper, we explore the ability to predict regional climate anomalies and glacier mass balance in the Canadian Rockies on the basis of 500‐mb circulation indices derived from the NCEP‐NCAR reanalysis dataset. Daily precipitation amounts and variance‐weighted seasonal temperature and precipitation anomalies at a suite of six long‐term meteorological stations in the Canadian Rockies (1953–2002) demonstrate a coherent dependence on the daily and mean seasonal atmospheric flow indices. The Peyto Glacier, Alberta, Canada offers the best available mass balance time‐series in the Canadian Rockies (1966–2004). Regression models for Peyto Glacier winter, summer, and annual mass balance variability were constructed from (1) Jasper climate anomalies, (2) regional climate anomalies, and (3) atmospheric flow indices. Model performance was examined in terms of the multiple coefficient of determination and of the variables retained in the stepwise regression analysis. Flow indices were the stronger predictors of mass balance. This offers important advantages for mass balance forecasts, because large‐scale circulation patterns are better captured than surface weather in mountain regions, in both reanalysed climatology and model‐generated climate change scenarios. Copyright © 2006 Royal Meteorological Society.
Systematic errors in the simulation of european climate (1961–2000) with RegCM3 driven by NCEP/NCAR reanalysis
Authors: Bergant Klemen , Belda Michal , Halenka Tomáš
Published: September 2006

Systematic errors of a European climate simulation (1961–2000) with RegCM3 were analyzed. Model results were compared to Climate Research Unit (CRU) observations. Average (AveB) and annual cycle biases (CycB) were evaluated for three surface variables: air temperature (TMP), water vapor pressure (VAP), and precipitation (PRE). The model shows a cold AveB over Europe with the exception of the northern part. It also shows a prevailing wet AveB. Annual PRE is underestimated only in regions with high average values, while VAP is overestimated over the entire European continent. The AveB is between − 1.2 °C and + 1.0 °C for TMP, 0.4 mb and 1.4 mb for VAP and − 15% and + 33% for PRC on annual/subcontinental scale. Most of the TMP and VAP CycB is related to the amplitude of annual cycle (CycA). The CycA of the TMP is underestimated over most of Europe. The CycA of the VAP is underestimated in some coastal regions and overestimated over the continental regions. The distinction between coastal and inland regions can also be seen in the CycB of the PRE. In coastal regions, with a PRE maximum in late autumn/early winter and minimum in summer, the CycA is underestimated. In some continental regions, with a precipitation maximum in summer and minimum in late autumn/early winter, the CycA is overestimated. The annual cycle pattern is not captured well by RegCM3 over the Alps and European Russia. Most of systematic errors in the RegCM3 simulation can be related to boundary conditions. Although the bias in NCEP/NCAR reanalysis is reflected in RegCM3 simulation, the RegCM3 enriches large‐scale information with regional details and with the more realistic description of annual cycles, especially for PRE. Because of these advantages and the overall relatively good performance of RegCM3, the model is seen as a valuable tool in regional projections of future climate change. Copyright © 2006 Royal Meteorological Society
Development of a three‐tier in vitro system, using Caco‐2 cells, to assess the effects of lactate on iron uptake and transport from rye bread following in vitro digestion
Authors: Bering Stine , Bukhave Klaus , Henriksen Marianne , Sandström Brittmarie , Pariagh Sandra , Fairweather‐Tait Susan J. , Lund Elizabeth K.
Published: September 2006

A three‐tier Caco‐2 cell system was developed to assess simultaneously iron dialysability, uptake and transport across the Caco‐2 monolayer from an in vitro digested food matrix. The effect of lactate (0–200 mmol L−1) on iron absorption from rye bread subjected to simulated peptic (pH 5.5) and pancreatic digestion (pH 6.5) was investigated to model absorption pre and post the sphincter of Oddi. Lactate increased dialysability (11.8%, P < 0.05) in peptic digests whereas it reduced it in pancreatic digests (4.9%, P < 0.001). Iron uptake from the peptic digests was in the region of 39–76 pmol mg−1 protein whereas it decreased from 281 to 51 pmol mg−1 protein in pancreatic digests. Iron transport was calculated for the peptic digests from [14C]polyethylene glycol movement and only at 200 mmol L−1 lactate was there any detectable transcellular transport (180 pmol mg−1 protein, P < 0.05). Iron absorption was positively correlated to dialysable iron for both digests (R2 = 0.48 and 0.41, respectively, P < 0.01) and the effect of lactate was therefore associated mainly with iron bioaccessibility. The three‐tier system showed the potential to obtain detailed insight into each step involved in iron transport across the monolayer from a food mixture. Copyright © 2006 Society of Chemical Industry
Beneficial effects of berry fruit polyphenols on neuronal and behavioral aging
Authors: Lau Francis C , Shukitt‐Hale Barbara , Joseph James A
Published: September 2006

It is becoming increasingly clear that although there is a great deal of research being devoted to elucidating the molecular mechanisms involved in aging, practical information on how to forestall or reverse the deleterious effects of aging may be years away. Therefore, it may be beneficial to determine other methods to improve the quality of life in the aging population. A plethora of epidemiological studies have indicated that individuals who consume a diet containing high amounts of fruits and vegetables may have a reduced incidence of age‐associated diseases such as cardiovascular or neurodegenerative diseases. Research from our laboratory has suggested that supplementation with fruit or vegetable extracts high in antioxidants can decrease the enhanced vulnerability to oxidative stress and inflammation that occurs in aging, and that these reductions are expressed as improvements in behavior. In addition to research indicating the antioxidant or anti‐inflammatory functions of the polyphenolic compounds found in these fruits and vegetables, further studies have suggested that other mechanisms such as cellular signaling may contribute to the beneficial effects of these compounds on aging. Copyright © 2006 Society of Chemical Industry
A microstrip‐fed cavity‐backed circularly polarized horn antenna
Authors: Seong Nak‐Seon , Park Seong‐Ook
Published: September 2006

A 20 GHz 2 × 2 subarray radiator of microstrip‐fed cavity‐backed circularly polarized horn is presented. Since horn antennas incorporating waveguide types of circular polarizers have big size of radiator height, microstrip feeding and polarization is proposed and cavity‐backed introduced to improve radiation performance. Two approaches of single and 2 × 2 subarray of horn are compared to be a basic radiation element of an array antenna. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2454–2456, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21952
A 80–100 GHz image‐reject passive‐HEMT mixer
Authors: Archer John W.
Published: September 2006

This paper describes a single‐sideband, subharmonically pumped, passive‐HEMT integrated circuit mixer developed for use in transceivers for point‐to‐point telecommunications in the 83–87 GHz band. The gallium arsenide (GaAs) monolithic microwave integrated circuit (MMIC) can readily be fabricated using a standard commercial process. The mixer performs equally well for either up‐ or down‐ conversion. For RF signals in the range 80–100 GHz, the conversion loss is typically 20 dB with LO drive in the range 40–50 GHz. Under these conditions, high rejection of the undesired sideband (>18 dB), relative to the desired signal, is achieved. For up‐conversion, 1 dB compression of the mixer gain typically occurs at −12 dBm RF output power. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2429–2433, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21953
Band‐notched ultra‐wideband slot antenna
Authors: Pan Chin‐Ju , Lee Chungnan , Huang Chih‐Yu , Lin Hsiao‐Cheng
Published: September 2006

This work presents a band‐notched ultra‐wideband (UWB) circular slot antenna free from interference with existing wireless systems. The antenna has an indented circular stub embedded inside the circular slot. The desired band‐notched UWB operation can be obtained by choosing the size of the pie‐slot cut in the circular stub. Details of the proposed design and experimental results of the constructed antennas are presented. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2444–2446, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21958
Electromagnetic interaction between resonant loop antenna and simulated biological tissue
Authors: Curto S. , Ammann M. J.
Published: September 2006

The electromagnetic interaction between a resonant loop antenna in proximity to biological tissue is examined in terms of field components, wave impedance, return loss, efficiency, and specific absorption rate (SAR). Various loop orientations are investigated with respect to the tissue, in order to provide the best coupling and power deposition into the body. An evaluation in terms of antenna detuning is also made. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2418–2421, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21959
CPW‐fed octave band slot antenna
Authors: Rao Patnam Hanumantha
Published: September 2006

In this paper, a compact coplanar waveguide‐fed slot antenna that can operate over an octaveband (1.75–3.7 GHz) is presented. The novelty of this antenna is the wideband operation with the radial stub loading. The front‐to‐back ratio of the antenna with a back plate is better than 25dB in H‐plane and better than 18 dB in E‐plane. The cross polarization level is around −20 dB over the band and the worst being at −15 dB. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2405–2408, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21963
Efficient near‐field to far‐field transformation from plane‐polar samples
Authors: Costanzo Sandra , Di Massa Giuseppe
Published: September 2006

The problem of rapid far‐field computation from near‐field samples acquired on a plane‐polar geometry is addressed in this paper. A fast processing algorithm is developed which uses the fast Fourier transform and the related shift theorem, by exploiting the convolution property of the radiation integral giving the antenna far‐field pattern. Numerical and experimental examples are discussed to prove the effectiveness of the proposed procedure. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2433–2436, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21964
Band‐notched ultra‐wideband square slot antenna
Authors: Chen Horng‐Dean , Li Jui‐Ni , Huang Yuh‐Fung
Published: September 2006

An ultra‐wideband (UWB) square slot antenna with a band‐notched characteristic is presented. The proposed antenna has a simple configuration and is easy to construct. The ultra‐wideband operation is realized by loading an offset rectangular stub at the end of the microstrip feed line. The band‐notched characteristic is achieved by embedding an U‐like slot in the rectangular stub. The notched frequency band can be controlled by adjusting the length of the U‐like slot. A design example for an UWB (3.1–10.6 GHz) square slot antenna with a notched frequency band at 5 GHz is demonstrated. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2427–2429, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21966
Patch‐type radio frequency identification tag antenna mountable on metallic platforms
Authors: Kim Sung‐Joo , Yu Byunggil , Chung Young‐Seek , Harackiewicz France J. , Lee Byungje
Published: September 2006

The simple and compact passive radio frequency identification (RFID) tag antenna mountable on metallic platforms is proposed. Without major modification of the radiating element and for easy impedance matching with various microchip impedances, an antenna is inductively coupled to a novel feeding structure placed on the side of a radiating patch. Using the commercial RFID system, radiation pattern and maximum distance are measured. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2446–2448, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21969
A new planar circular disc‐and‐ring monopole antenna for UMTS/UWB dual‐network applications
Authors: Kang Yu‐Cheng , Chiu Cheng‐Nan , Deng Sheng‐Ming
Published: September 2006

A new, low‐profile planar circular disc‐and‐ring monopole antenna is proposed for dual‐band and ultra‐wideband (UWB) operations. The first band is specified for the universal mobile telecommunication system (UMTS, 1.92–2.17 GHz) and the second is for the FCC‐defined UWB system (3.1–10.6 GHz). A prototype of the antenna has been constructed and demonstrates optimal performance. Measured and simulated return loss and measured radiation patterns have been obtained. Sufficient impedance bandwidth and omni‐directional radiation performance in both bands have been observed and show promise for the UMTS/UWB dual‐network applications. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2396–2399, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21970
Stable ns pulses generation from cladding‐pumped Yb‐doped fiber laser
Authors: Shuling Hu , Guangrong Yang , Yu Jing , Chunqing Gao , Guanghui Wei , Fuyun Lu
Published: September 2006

In this paper the generation of stable ns pulses by a laser diode pumped Yb‐doped double‐clad fiber laser is demonstrated. The fiber laser with two‐mirror cavity operates in a self‐Q‐switching regime, the Q‐switch mechanism of which is based on stimulated Brillouin scattering (SBS). With different reflectivity of the second mirror, stable, pulse width ranging of 10 ns to less than 2 ns pulses are obtained. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2442–2444, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21973
Internal GSM/DCS/PCS antenna for USB dongle application
Authors: Wong Kin‐Lu , Kuo Cheng‐Hao
Published: September 2006

A GSM/DCS/PCS internal antenna suitable to be embedded at the widened end portion of a promising USB dongle for wireless network access in a laptop computer is presented. The proposed internal antenna uses two separate resonant strips folded into a compact structure to generate two wide operating bands at about 900 and 1800 MHz to cover the GSM and DCS/PCS operations. In addition, although in a compact structure, the antenna's two resonant strips are designed to be less coupled, thus allowing the antenna's lower and upper bands to be adjusted separately, without affecting each other. Details of the USB dongle embedded with the proposed internal antenna are described, and experimental results are presented and discussed. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2408–2412, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21974
Generic microstrip structure for the realization of all‐type broadband filters
Authors: Gündüz Sibel , Çakir Gonca , Sevgi Levent
Published: September 2006

A generic microstrip structure is used for the design of all‐type broadband filters, based on the analogy between wave and transmission line theories. A Matlab‐based lumped (LC) and scattered (microstrip line) filter design tool is developed for the automation of the filter design. Sample lowpass, highpass, bandpass, and bandstop filters are designed and their operational characteristics are validated via in‐house prepared FDTD‐based virtual microstrip circuit simulator. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2390–2393, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21975
A microstrip‐fed quasi‐rhombus shape double dipole antenna for wideband phased array applications
Authors: Eldek Abdelnasser A. , Zheng Guiping
Published: September 2006

In this paper, the regular microstrip dipole antenna shape is modified by adding upper and lower triangular patches, which makes it look like a rhombus. The rhombus shape is chosen because of its wideband characteristics over the rectangular one. The presented antenna provides a wide bandwidth of more than 100%. The measured and computed VSWR and radiation patterns for one element and the mutual coupling for two elements are presented in the paper. The proposed antenna provides endfire radiation patterns with wide beamwidth and low cross polarization level which make it a good candidate for phased arrays and radar systems. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2461–2464, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21978
Ultra wideband embedded planar inverted conical antenna
Authors: Gupta Sachin , Ramesh M. , Kalghatgi A. T.
Published: September 2006

A compact CPW fed planar inverted conical antenna with coplanar ground embedding the radiator has been studied with regard to its suitability for the UWB transceivers operating over 3.1–10.6 GHz. Performance of planar inverted conical antenna embedded in a similar shaped ground plane is compared with the planar inverted conical antenna having ground in plane with the radiator. Results from the simulations have been validated through experimentations. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2465–2468, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21980
Metamaterial inclusions based on grid‐graph Hamiltonian paths
Authors: Pierro Vincenzo , McVay John , Galdi Vincenzo , Hoorfar Ahmad , Engheta Nader , Pinto Innocenzo M.
Published: September 2006

This article deals with a study of novel classes of metamaterial inclusions based on space‐filling curves. The graph–theoretic Hamiltonian‐path (HP) concept is exploited to construct a fairly broad class of space‐filling curve geometries that include as special cases the well‐known Hilbert an Peano curves whose application to metamaterial inclusions has recently been proposed. In this framework, the basic properties of HP are briefly reviewed, and a full‐wave study of the electromagnetic properties of representative grid‐graph HP geometries is carried out. Applications to metamaterial inclusions are explored, with focus on artificial magnetic conductors with reduced polarization‐sensitivity. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48:2520–2524, 2006; Published online in Wiley InterScience (www.interscience.wiley.com).DOI 10.1002/mop.21982
Switching of electrical and magnetic resonances in Omega structures by a reflection operation experimental studies
Authors: Varadan Vasundara V. , Ro Ruyen , Penumarthy Sravanthi
Published: September 2006

Omega shaped metallization on a dielectric substrate if appropriately designed will exhibit plasmonic resonances when excited by microwaves. We present experimental results for the complex S‐parameters for four types of metamaterial slabs constructed with discrete omega shapes in a rectangular lattice. A double layer of omega shapes in a rectangular lattice is obtained by reflecting the pattern of one strip by +180° (Omega A), the third sample is realized by reflecting one strip by −180° (Omega B) and the fourth sample (Omega C) is realized by an alternate arrangement of the Omega A and Omega B samples in a rectangular lattice. The single layer sample is asymmetric (S11 ≠ S22), the two mirror image pair samples are perfectly symmetric with S11 = S22. Plasmonic resonances and band gaps were observed. The complex S‐parameters were used to extract the complex permittivity and permeability of the symmetric samples by inverting Fresnel formulae for the reflection and transmission coefficients of a planar slab normally illuminated by a plane wave. The data of the asymmetric sample was inverted with this procedure to obtain two sets of data, one set using S11 and S21 and another set using S22 and S12 for the extraction of complex parameters. A reflection operation on the Omega geometry by ±180° results in the switching of the electric and magnetic properties in certain frequency ranges. Band gaps have been observed for both Omega A and Omega B that coincide with short circuit regions for the real part of the impedance. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2624–2629, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21984
High‐gain wideband low‐profile antenna
Authors: Mateos Rosa M. , Craeye Christophe , Toso Giovanni
Published: September 2006

When trying to increase the bandwidth of antennas based on high‐impedance surfaces, the radiation pattern tends to split near the resonance frequency of the artificial perfect magnetic conductor (PMC). This problem is solved here by reducing the size of the PMC in the E‐plane and by making it nonperiodic in the H‐plane. Using a dual‐dipole as a radiating element, a 30% impedance bandwidth is achieved with directivity larger than 9 dB over the whole useful band. In view of the antenna's horizontal dimensions, this is close to the maximum achievable directivity. The total antenna height is 0.15λ, where λ corresponds to the wavelength at the highest frequency. A study of the surface currents on the patches supports the phenomena observed on the radiation patterns. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2615–2619, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21987
FMM and FDTD analysis of a woodpile 3D‐EBG superstrate for patch antennas
Authors: Frezza F. , Nocito P. , Pajewski L. , Schettini G.
Published: September 2006

A fast and accurate modeling of the transmission and reflection properties of 3D‐EBGs can be performed by exploiting a Fourier modal method (FMM), which in the literature is regarded as the most efficient and prevailing rigorous technique for the analysis of doubly‐periodic gratings. Putting a woodpile EBG superstrate on a customary microstrip‐patch feed, an antenna with highly directional radiation pattern can be obtained. The ensemble constituted by the perfectly conducting plane and the woodpile EBG can be schematized by means of an equivalent resonating all‐dielectric structure, which has been studied by using our FMM tool for 3D‐EBGs. Subsequently, the behavior of the whole radiating device has been checked with a finite difference time domain technique. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2595–2598, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21991
Modeling of spatial gap solitons in nonlinear waveguide arrays
Authors: Armaroli A. , Valentini S. , Bellanca G. , Trillo S.
Published: September 2006

We discuss the modeling of self‐trapping in arrays of evanescently coupled optical waveguides with Kerr nonlinear response, contrasting two different approaches. Our results show that the coupled mode equations describe with good accuracy, in a wide range of the parameter values of physical interest, the gap soliton self‐trapped solutions that can propagate from beams interfering at Bragg angles. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2591–2595, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21992
Basic radiation properties of waveguides filled with uniaxial single‐negative metamaterials
Authors: Hrabar Silvio , Jankovic Gordan
Published: September 2006

Basic radiation properties of miniaturized open‐ended waveguide radiators based on anisotropic, either mu‐negative (MNG) or epsilon‐negative (ENG) fillings, have been investigated experimentally. It was found that a resonant MNG filling offers a high degree of antenna miniaturization with narrowband operation and pronounced losses, a wire‐based ENG filling offers low degree of miniaturization with very low losses, while the ENG filling based on inductively loaded wires offers both high degree of miniaturization and low‐loss operation. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2587–2591, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21993
MEMS‐based high‐impedance surfaces for millimeter and submillimeter wave applications
Authors: Chicherin Dmitry , Dudorov Sergey , Lioubtchenko Dmitri , Ovchinnikov Victor , Tretyakov Sergei , Räisänen Antti V.
Published: September 2006

The authors propose to use microelectromechanical systems (MEMS) to produce novel phase shifters based on an electronically reconfigurable high‐impedance surface (HIS). Typically, HIS is a textured metal surface with reactive impedance varying from an initial value to a very high value. Such phase shifters can be developed with introducing a surface with variable impedance in, e.g., a rectangular metal or dielectric rod waveguide. Placed along narrow walls of the rectangular metal waveguide or adjacent to the dielectric waveguide, the HIS affects the propagation constant, which results in changing the phase of the propagating wave. The authors manufactured a prototype of the microelectromechanical systems‐based HIS consisting of a dielectric layer placed on a ground plane, and two arrays of metal patches. The gap between the upper and lower arrays of patches was fixed and filled with SiO2. The measured phase of the wave reflected from the prototype HIS varies in the range of 50°, and its insertion loss is below 0.5 dB (out of resonance). © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2570–2573, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21997
Microwave harmonic emission in MgB2 superconductor: Comparison with YBA2CU3O7
Authors: Gallitto A. Agliolo , Bonsignore G. , Di Gennaro E. , Giunchi G. , Vigni M. Li , Manfrinetti P.
Published: September 2006

We report results of microwave second‐harmonic generation in ceramic samples of MgB2, prepared by different methods. The SH signal has been investigated as a function of the temperature and the static magnetic field. The results are discussed in the framework of models reported in the literature. We show that the peculiarities of the SH signal are related to the specific properties of the sample. A comparison with the results obtained in ceramic and crystalline YBa2Cu3O7 shows that the second‐harmonic emission in MgB2 is weaker than that observed in ceramic YBa2Cu3O7. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2482–2486, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22001
High directivity in low‐permittivity metamaterial slabs: Ray‐optic vs. leaky‐wave models
Authors: Lovat Giampiero , Burghignoli Paolo , Capolino Filippo , Jackson David R.
Published: September 2006

A study is presented on the directivity of grounded low‐permittivity metamaterial slab structures that achieve highly directive broadside radiation. Two‐dimensional (2D) configurations excited by electric line sources are considered, adopting a scalar plasma‐like dispersive permittivity for the metamaterial medium that suitably models a wire medium in the presence of a 2D electromagnetic field, with the electric field directed along the wire axes. The role of leaky waves in producing the high directivity attainable with such structures is illustrated by comparing it with a simple ray‐optic model for the radiation mechanism. We show how for increasing substrate heights, the leaky‐wave effect (dominant for “optimal” thicknesses, and responsible for the very high directivity) evolves into a lensing effect purely explained with ray‐optics, when losses are present. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2542–2548, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22004
Multiband planar antennas on electromagnetic bandgap substrates: Complex global optimization of the structure
Authors: Horák Jiří , Chmela Petr , Oliva Lukáš , Raida Zbyněk
Published: September 2006

The paper presents a complex global optimization of a four‐band planar antenna on an electromagnetic bandgap substrate. As a typical representative of such antennas, a triple U‐slot patch antenna is chosen. The full‐wave model of the antenna is developed in CST Microwave Studio. Simulation results are exported to macros in Visual Basic, and the structure is optimized by the particle swarm algorithm, which simultaneously changes parameters of the substrate and the layout. As an optimization criterion, impedance matching in the GSM bands and the Bluetooth one is considered. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48:2532–2534, 2006; Published online in Wiley InterScience (www.interscience.wiley.com).DOI 10.1002/mop.22006
Time‐domain characterization of antennas in metamaterial media
Authors: Raida Zbyněk , Láčík Jaroslav , Horák Jiří , Chmela Petr , Oliva Lukáš
Published: September 2006

In this article, a wire dipole embedded within a double‐negative medium is numerically analyzed using the time‐domain integral equation method. The antenna is excited by a narrow Gaussian pulse to obtain responses within a wider frequency band. The transient current distribution on the antenna is processed so as to obtain a time‐domain radiation pattern and to compute the gain. Time‐domain parameters are obtained by calculating mean‐value quantities, which are then compared with the conventional frequency‐domain parameters, using Parseval's theorem. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48:2530–2532, 2006; Published online in Wiley InterScience (www.interscience.wiley.com).DOI 10.1002/mop.22007
New physical effects at an air pseudochiral omega interface: Surface polaritons and proper leaky‐modes
Authors: Matos Sérgio A. , Paiva Carlos R. , Canto João R. , Barbosa Afonso M.
Published: September 2006

Surface polaritons are guided electromagnetic waves propagating along a single interface, with the amplitude of the field decreasing along the direction that is normal to the interface. These modes can propagate along interfaces separating a conventional (double‐positive) isotropic medium either from a single‐negative or from a double‐negative medium. They were also found to propagate along isotropic–uniaxial and isotropic–biaxial interfaces. In this paper we show, for the first time, that surface polaritons can also occur at an interface between air and a pseudochiral omega medium. It is also shown, furthermore, that proper leaky‐modes can also exist in this special type of isotropic–bianisotropic interface—a completely new physical effect for a single interface between two lossless media. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48:2517–2520, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22009
Transparent‐ferromagnetic thermoplastic polymers for optical components
Authors: Carotenuto G. , Pepe G. , Davino D. , Martorana B. , Perlo P. , Acierno D. , Nicolais L.
Published: September 2006

Optical plastics filled by nanosized magnetic particles may have important applications in the optical field (e.g. magneto–optics, etc.). Amorphous polystyrene filled by acicular magnetite particles of nanosized dimension (ca. 10 nm × 50 nm) has been obtained by thermal decomposition (at 200°C) of iron(II) mercaptide dissolved in the polymer. This nanocomposite material is quite transparent to visible light and shows ferromagnetic characteristics at room temperature. In particular, magnetic properties behaves anisotropically in the material and are related to the magnetite content. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2505–2508, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22012
Metamaterial transmission lines with extreme impedance values
Authors: Gil Marta , Gil Ignacio , Bonache Jordi , García‐García Joan , Martín Ferran
Published: September 2006

In this work, it is demonstrated that it is possible to synthesize the metamaterial transmission lines with extreme characteristic impedances. The structures consist on left‐handed microstrip lines based on the combination of complementary split rings resonators (CSRRs), which are etched in the ground plane, and series capacitive gaps. By means of an adequate design, it is possible to tailor the characteristic impedance of the lines over a wide margin. The realizable impedance values are not easily achievable through conventional transmission lines implemented in commercial microwave substrates. Several illustrative examples are provided and the limitations of the technique (relative to the maximum and minimum achievable impedances) are discussed. The compact dimensions of these artificial lines, related to the small electrical size of CSRRs, are also pointed out. These structures can be applied to the design of microwave components with severe requirements concerning characteristic impedance. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2499–2506, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22013
Performance evaluations of microwave power amplifiers with single‐ and multi‐carrier quadrature amplitude modulations
Authors: Huang Chien‐Chang , Chen Kuan‐Yu
Published: September 2006

This article presents the performance evaluations of microwave power amplifiers (PAs) for different kinds of quadrature amplitude modulation (QAM) schemes including π/4‐DQPSK and 16‐QAM for single‐carrier formats and orthogonal frequency division multiplexing (OFDM) for multi‐carrier configuration, by using the time‐domain signal processing technique and the hybrid Volterra analysis. The influences due to various peak‐to‐average power ratios (PAPRs) of the modulation signals for the PA performances such as output powers, adjacent channel power ratios (ACPRs), and error vector magnitudes (EVMs) are shown with experimental verifications. A figure‐of‐merit of PAs based on linearity and efficiency is presented to establish a criterion for choosing the best working condition. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2375–2378, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22020
A multi‐centre evaluation of absorbent products for men with light urinary incontinence
Authors: Fader Mandy , Macaulay Margaret , Pettersson Lena , Brooks Rodney , Cottenden Alan
Published: September 2006

Aims

This study compared the performance of the four main designs of absorbents for men with light incontinence: pouches (shields), leafs (guards), washable pant with integral pad (pantegral), and small disposable pad.

Materials and Methods

We did a multiple crossover trial. Men with light urinary incontinence were recruited. All pouches and leafs available in the UK were identified for inclusion. A single pantegral and small pad were selected based on previous evaluations for design comparison. Products were tested in random order for up to 1 week. Performance criteria (e.g., leakage and comfort) were rated using a validated product performance questionnaire. Wet product weights and amount of leakage were recorded in pad leakage diaries. “Overall opinion” for design performance was used as the primary outcome indicator.

Results

Seventy‐four men tested six leafs, six pouches, one pantegral, and one small pad. Leakage data was taken from 3,386 wet pads. The pouches generally performed poorly with few significant differences between products. The leafs were more variable with large and significant differences in ratings. Overall the leaf, pantegral, and small pad designs performed significantly better than the pouch (P ≤ 0.01) and the pantegral design performed significantly worse than the leaf (P = 0.01). One leaf product was outstanding and performed significantly better than all other designs (P ≤ 0.001).

Conclusion

This is the first published trial of absorbent products specifically designed for men. Results show that one particular leaf product works best, the pantegral is most suitable only for very light incontinence and the pouches are least successful. Neurourol. Urodynam. 25:689–695, 2006. © British Crown Copyright 2006/DERA—Published with the Permission of the Controller of Her Majesty's Stationery Office.
Cytokine production following experimental implantation of xenogenic dermal collagen and polypropylene grafts in mice
Authors: Zheng Fang , Xu Luo , Verbiest Lieve , Verbeken Eric , De Ridder Dirk , Deprest Jan
Published: September 2006

Aim

We earlier showed that xenogenic Pelvicol (Bard, Olen, Belgium) implants induce a lesser inflammatory response than Prolene (Johnson and Johnson, Dilbeek, Belgium). The purpose of this study was to determine cytokine profiles in the host immune responses to Pelvicol in a mouse model. The hypothesis was that Pelvicol would induce a “T‐helper2” (Th2) rather than T‐helper1 (Th1) type of inflammatory response.

Methods

Mice were implanted subcutaneously with Pelvicol or Prolene and the graft sites were harvested at 3 to 28 days. Histopathology was done and cytokine levels were determined by immunohistochemistry and RT‐PCR. Flow cytometry was used to identify which cell population contributed to the observed cytokine production profiles.

Results

Pelvicol induced a decreased inflammation and displayed an increase in IL‐10 and TGF‐β, but reduce of TNF‐α and IFN‐γ, indicating a Th2 type dominated response as examined by immunohistochemistry and RT‐PCR. Flow cytometry showed that the monocytes/maceophages were the main cell population responsible for production of these cytokines. Monocytes/maceophages from Pelvicol explants showed upregulated expression of IL‐10 while Prolene explants expressed TNF‐α.

Conclusion

Pelvicol induced a Th2 type cytokine‐dominated immune response after subcutaneous implantation in mice. Neurourol. Urodynam. 26:280–289, 2007. © 2006 Wiley‐Liss, Inc.
In patients undergoing neuromodulation for intractable urge incontinence a reduction in 24‐hr pad weight after the initial test stimulation best predicts long‐term patient satisfaction
Authors: Foster Raymond T. , Anoia Elizabeth J. , Webster George D. , Amundsen Cindy L.
Published: September 2006

Aims

To evaluate long‐term patient satisfaction of sacral neuromodulation and to correlate satisfaction with incontinence parameters.

Methods

Patients at least 1‐year remote from sacral neuromodulation were mailed a questionnaire to evaluate satisfaction and assess incontinence symptoms.

Results

Fifty‐two patients were consecutively enrolled in the study. Forty‐nine questionnaires (94.2%) were returned. The average interval between implantation and questionnaire completion was 27.2 (range 12–52) months. 83.7% of respondents were satisfied and 79.6% of patients would “do it all over again.” Compared to dissatisfied subjects during test stimulation, the satisfied patients had a significant decrease in 24‐hr pad weight (84.5% vs. 60.6%, P = 0.002) but did not differ in daily pad usage (4.5 fewer pads per day vs. 3.4, P = 0.190). At long‐term follow‐up, satisfied patients noted significantly greater improvement in their Incontinence Impact Questionnaire score versus dissatisfied patients (mean improvement 53 vs. 10 points, P = 0.0003). Using multiple logistic regression, change in 24‐hr pad weight, but not change in average daily pad usage, was correlated with long‐term satisfaction.

Conclusions

Eighty‐four percent of patients were satisfied with sacral neuromodulation at a mean of 27 months. An 84.5% reduction in 24‐hr pad weight correlated with long‐term patient satisfaction. In addition to lack of efficacy, device pain was a contributing factor to dissatisfaction. Neurourol. Urodynam. 26:213–217, 2007. © 2006 Wiley‐Liss, Inc.
Use of albumin in three French university hospitals: is prescription monitoring still useful in 2004?
Authors: Pradel Vincent , Tardieu Sophie , Micallef Joëlle , Signoret Anne , Villano Philippe , Gauthier Laurence , Vanelle Patrice , Blin Olivier ,   For the Albumin Study Group
Published: September 2006

Purpose

Use of albumin (indications and quantities involved) has not been assessed in France since major changes occurred after the publication of Cochrane group meta‐analysis. The objectives of this study were to measure the repartition of albumin indications in three French university hospitals in 2004 and to assess the feasibility and usefulness to implement a prescription‐monitoring program.

Methods

Exhaustive record of albumin prescription during 2 months in three French university hospitals of Marseille. Inclusion of all patients with a first prescription of albumin between 15 March 2004 and 15 May 2004. Indication, formulation and quantity prescribed were recorded for each prescription.

Results

One hundred and eighty‐seven patients received a total of 426 prescriptions for a total quantity of 21 094 g of albumin during the study. The first indications were hypoalbuminemia (33% of total quantity), plasmapheresis (30.2%) and ascites or hepatorenal syndrome (13.7%). Fifty per cent of total quantity was used by 14 patients (7.5% of included patients).

Conclusions

Most of albumin consumption in our study is concentrated on recognized indications or indications without alternative to albumin. The different levels of analysis (number of patient treated, number of prescription and quantities used) must be taken into account when analyzing medications such as albumin. Only a marginal proportion of consumption is expected to be saved with close monitoring of indications. Copyright © 2006 John Wiley & Sons, Ltd.
Novel doubly polymerizable functional norbornene: Its synthesis, reactivity, and macromolecular architectures from a dual cure via ring‐opening metathesis polymerization and radical photopolymerization
Authors: Liaw Der‐Jang , Huang Ching‐Cheng , Hong Shou‐Mau
Published: September 2006

A novel doubly polymerizable functional norbornene, 5‐(methacryloyloxyethylamino carboxylmethyl)bicyclo[2.2.1]hept‐2‐ene (NBMOACM), was prepared. The ring‐opening metathesis polymerization (ROMP) of NBMOACM was carried out to prepare polymers with crosslinkable side chains with the Grubbs catalyst. No gel formation occurred during the ROMP of NBMOACM. The 1H NMR spectrum of poly(NBMOACM) showed broad signals between 5.10 and 5.40 ppm, corresponding to the vinyl protons of the cis and trans double bonds of the ring‐opened polymer. Increasing the ratio of the monomer concentration to the catalyst concentration resulted in the formation of higher molecular weight polymers. Poly(NBMOACM) was incorporated into poly(methyl methacrylate) [poly(MMA)] to produce AB crosslinked materials. These crosslinked materials [1 wt % poly(NBMOACM), 10% weight loss temperature = 300 °C in air] had higher thermal stability than pure poly(MMA) (10% weight loss temperature = 276 °C in air). © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6287–6298, 2006
A novel synthesis of polymer brush on multiwall carbon nanotubes bearing terminal monomeric unit
Authors: Ha Jin Uk , Kim Myunghun , Lee Jeongwoo , Choe Soonja , Cheong In Woo , Shim Sang Eun
Published: September 2006

A novel approach to fabricate polymer brushes on the surface of carbon nanotubes (CNTs) is proposed. Carboxyl groups on the surface of chemically oxidized CNTs were reacted with hexamethylene diisocyanate, followed by a reaction with methacrylamide to give terminal vinyl groups‐functionalized CNTs, so called “CNT‐mer.” The synthetic procedure was investigated step‐by‐step and the synthesized CNT‐mer was used to grow polystyrene (PS) from CNTs by a simple in situ polymerization in the presence of a thermal initiator. By employing 1H NMR, X‐ray photoelectron spectroscopy, thermogravimetric analysis, scanning electron microscopy, transmission electron microscopy, and light scattering, the experimental results were verified. Using this approach, 45% PS with respect to CNTs are grafted on the surface of CNTs with about 4.0 nm thickness. This novel technique would provide a facile route to prepare tailor‐made polymer brushes on the surface of CNTs. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44:6394–6401, 2006
Relaxational behavior of poly(4‐tetrahydropyranyl) methacrylate
Authors: Sanchis Maria J. , Domínguez‐Espinosa Gustavo , Díaz‐Calleja Ricardo , Alegría Luz , Gargallo Ligia , Radić Deodato
Published: September 2006

Complex permittivity of poly(4‐tetrahydropyranyl methacrylate) (P4THPMA) was measured by dielectric spectroscopy. The spectra obtained show several relaxation processes labeled as δ, γ, β, and α in increasing order of temperature. These processes have been characterized and assigned to specific molecular motions. Comparison of the dielectric activity obtained for P4THPMA with those reported for poly(1,3‐dioxan‐5‐yl‐methacrylate) (PDMA) and poly(cyclohexyl methacrylate) (PCHMA) was performed. In fact, these three polymers have similar chemical structures with aliphatic rings in the ester residue. However, significant differences between the dielectric behavior of these polymers have been observed. In addition, complementary molecular mechanic (MM) calculations have been carried out. The energy barriers obtained by these calculations lead to energy barriers which are in relatively good agreement with those derived from the dielectric measurement by means Arrhenius plots. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 3135–3147, 2006
Predisposition of the dark state of rhodopsin to functional changes in structure
Authors: Isin Basak , Rader A. J. , Dhiman Harpreet Kaur , Klein‐Seetharaman Judith , Bahar Ivet
Published: September 2006

As the only member of the family of G‐protein‐coupled receptors for which atomic coordinates are available, rhodopsin is widely studied for insight into the molecular mechanism of G‐protein‐coupled receptor activation. The currently available structures refer to the inactive, dark state, of rhodopsin, rather than the light‐activated metarhodopsin II (Meta II) state. A model for the Meta II state is proposed here by analyzing elastic network normal modes in conjunction with experimental data. Key mechanical features and interactions broken/formed in the proposed model are found to be consistent with the experimental data. The model is further tested by using a set of Meta II fluorescence decay rates measured to empirically characterize the deactivation of rhodopsin mutants. The model is found to correctly predict 93% of the experimentally observed effects in 119 rhodopsin mutants for which the decay rates and misfolding data have been measured, including a systematic analysis of Cys→Ser replacements reported here. Based on the detailed comparison between model and experiments, a cooperative activation mechanism is deduced that couples retinal isomerization to concerted changes in conformation, facilitated by the intrinsic dynamics of rhodopsin. A global hinge site is identified near the retinal‐binding pocket that ensures the efficient propagation of signals from the central transmembrane region to both cytoplasmic and extracellular ends. The predicted activation mechanism opens the transmembrane helices at the critical G‐protein binding cytoplasmic domain. This model provides a detailed, mechanistic description of the activation process, extending experimental observations and yielding new insights for further tests. Proteins 2006. © 2006 Wiley‐Liss, Inc.