bluuebunny/crossref_metadata_2025 huggingface dataset:
RF optoelectronic oscillator using a directly modulated semiconductor laser and a fiber optical ring filter
Authors: Kotb H. E. , Safwat A. M. E. , Boghdady H. , Khalil D. A. M.
Published: December 2008

In this article we present an RF optoelectronic oscillator based on directly modulated laser diode and an all optical RF filter. The system is modeled and simulated using standard simulators. Using commercial modules and standard single mode fiber, the implemented system shows an RF oscillation with 9.8 dBm at 1.1 GHz. We also show that the use of an all optical RF filter allows a sidemode suppression ratio more than 50 dB without affecting the signal purity. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 470–475, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24069
Dual‐band square slot antenna with embedded crossed strips for wireless local area network applications
Authors: Sze Jia‐Yi , Chang Wei‐Shan
Published: December 2008

A new compact microstripline‐fed square slot antenna with embedded crossed strips is proposed for dual‐band wireless local area network (WLAN) applications. Connected to the two upper inner corners of the slotted ground, the crossed strips can extend the path of the current distributed on the ground plane, thus effectively lowering the first resonant band of the antenna. The ratio of the center frequencies of the first two resonant bands can be tuned within a range of 1.8–2.6 by adjusting the angle between the crossed strips and the length of the parts of the crossed strips below the intersection point. An antenna prototype suitable for 2.45/5.25‐GHz WLAN bands was successfully designed and fabricated for verification. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 435–439, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24070
Closed‐form expression of asymmetric stripline open‐end and its applications for analysis of LTCC components and circuits
Authors: Tang Wanchun , Yu Zhengyong , Nai Yu , Chow Y. Leonard
Published: December 2008

In this article, we have obtained simple excess capacitance formula for asymmetric stripline open‐end. The average error of the formula is less than 2%. On the basis of this formula and the field‐based equivalent circuit model obtained by the authors before, a low‐pass filter and an edge coupled stripline band‐pass filter are analyzed by the field‐based equivalent circuit together with the excess capacitance formula of this article. Compared with numerical results, the average errors of S parameters are less than 2%. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 406–408, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24072
Substrate integrated waveguide fed printed dipole array antenna for isolating the RF front‐end from the antenna
Authors: Yu Chen , Hong Wei , Kuai Z. Q. , Chen J. X. , Tian Ling , Yan P. P.
Published: December 2008

A novel feeding structure using substrate integrated waveguide technique for double side printed dipole antenna is presented in this article, which isolates the RF front‐end from the antenna effectively in an integrative radio access unit of distributed wireless communication systems. An array antenna with eight double side printed dipoles is designed and fabricated. The return losses and radiation patterns of the antenna element and the array antenna are measured, and the results are in good agreement with the simulated results. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 557–562, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24075
Design and implementation of planar ultra‐wideband antennas characterized by multiple notched bands
Authors: Dong Yuan Dan , Hong Wei , Zhou Jian Yi , Kuai Zhen Qi
Published: December 2008

A new approach for the design of planar ultra‐wideband (UWB) antennas having multiple band‐notched functions is studied and presented. In this approach, a planar dual‐stopband filter based on a dual‐mode resonator is first investigated carefully, which employs a half‐mode substrate‐integrated waveguide cavity to improve the quality (Q) factor. Then, this filter is applied to the design of a UWB antenna with dual band‐notched characteristics. Finally, two triple band‐notched antennas are implemented by incorporating two different resonators in the radiation element of the UWB antenna, respectively. Voltage standing wave ratio (VSWR), gain, and radiation pattern are measured. High and sharp band‐rejection characteristic for each of the frequency notch as well as a very wide impedance bandwidth is achieved. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 520–426, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24076
A compact wideband microstrip bandpass filter using parallel‐coupled‐lines with periodical grooves
Authors: Li Lin , Li Zheng‐Fan
Published: December 2008

A wideband bandpass filter using parallel‐coupled‐lines with periodical grooves is presented in this article. Owing to the slow wave effect brought by periodical grooves, the proposed structure's resonant frequency can be lowered effectively. This effect has been used in this article to realize wideband filter with compact size. Based on this theory, a two‐pole compact wideband bandpass filter using proposed structures is designed and fabricated as a sample. The simulated and measured results show the validity of the proposed structure. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 518–520, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24077
A right slotted patch dual‐mode dual band bandpass filter used for WLAN
Authors: Su Yan‐Kuin , Chen Jau‐Rung , Weng Min‐Hang , Hung Cheng‐Yuan
Published: December 2008

We proposed a novel dual‐mode dual band bandpass filter (BPF) operating at 2.4/5.7 GHz by using a right cross‐slotted patch resonator (RCSPR) combined with a pair of square etched areas (SEAs). A pair of right crossed slot embedded in the center of the patch resonator is used to tune the resonant modes having 2.4/5.7 GHz responses. In this design, a pair of SEAs etched within the RCSPR is provided to be the perturbation element to generate the filter performance with the transmission zeros near the passband edges. It is shown that the fabricated filter has good dual‐band performances at 2.4/5.7 GHz with high selectivity, narrow bandwidth, and very sharp attenuation rate due to the existence of the transmission zeros. Measured results of the fabricated BPF have a good agreement with the full‐wave simulation results. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 491–494, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24078
An integral equation‐fast Fourier transform‐based hybrid method for analysis of wire‐surface configurations on electrically large platforms
Authors: An Xiang , Lü Zhi‐Qing
Published: December 2008

This article presents an efficient hybrid method with the IE‐FFT algorithm for solving scattering and radiation problems of wire antennas mounted on electrically large platforms. To model arbitrary metallic structures, including wire antennas and both open and closed surfaces, in this method, the electric field integral equation (EFIE) and the magnetic field integral equation (MFIE) are applied separately to geometrically distinct regions of an object. The EFIE is used to represent wire antennas and open surfaces, while the MFIE is employed for closed surfaces to improve the convergence rate. The resulting matrix system is solved by an iterative algorithm, and the IE‐FFT method is adopted to reduce the memory requirements and computational complexity toO(N1.5) andO(N1.5logN), respectively, for three‐dimensional perfectly electric conductor problems. Some numerical examples are provided to demonstrate the accuracy and efficiency of the method. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 486–490, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24079
Multiband (WiBro/WCDMA/CDMA 2000 1×) voltage‐controlled oscillator for mobile communication
Authors: Lee Sangho , Lee Jaehyuk , Park Jihyun , Kim Hyeongdong
Published: December 2008

In this article, a fully integrated multiband voltage‐controlled oscillator (VCO) implemented in a 0.18‐μm CMOS process is presented. A complementary differential structure that consists of NMOS and PMOS transistors is used for low power consumption. To achieve good phase noise performance, no current source is used in the structure. MOS switches are employed for multiband selection. In addition, four MOS varactors are added for band fine tuning; the first pair of MOS varactors is employed for channel selection, and the second pair of MOS varactors and MOS switches is employed for band selection. The total chip area of the VCO is 1.2 mm × 0.85 mm. The measured phase noise levels of the VCO are −98.8 dBc at 100 kHz, −116.4 dBc at 1MHz, −135 dBc at 10 MHz for CDMA 2000 1×, WCDMA, and WiBro, respectively. The VCO draws 13 mA and consumes 23.4 mW with output buffers within the operating frequency of a 1.8 V supply. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 416–418, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24081
A novel P‐shaped printed monopole antenna for RFID applications
Authors: Yang Hanhua , Yan Shu
Published: December 2008

In this article, a novel p‐shaped printed monopole antenna is first proposed to operate simultaneously at the 2.45 and 5.8 GHz bands for radio frequency identification tag. Printed on a standard 1.6 mm FR4 substrate material, the printed monopole antenna has been demonstrated to provide an ultra wide 10 dB return loss bandwidth with satisfactory gains and radiation properties. The parameters which affect the performance of the antenna in terms of its frequency domain characteristics are investigated. A good agreement is achieved between the simulation and the experiment. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 554–556, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24083
The miniature microstrip square‐ring 2.4/5.2 GHz dual‐band bandpass filter
Authors: Kung Cheng‐Yuan , Chen Yin‐Chung , Yang Cheng‐Fu , Chen Hua‐Ming
Published: December 2008

A 2.4/5.2 GHz dual‐band bandpass filter is designed and printed on Al2O3 ceramic substrate. The filter is based on two square‐patch resonators and two T‐type input/output lines. The square‐ring structure is used to replace the square‐patch for minimization because of longer current path. Using the higher dielectric constant and loss tangent ceramic substrate, the proposed filters have the advantages of low insertion loss, high out‐of‐band rejection, mini size, and simple structure. As compared to the square‐patch filter, the proposed square‐ring filter has 51% size reduction. And the measured results of the fabricated filters have good agreement with the simulated values. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 515–518, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24085
Design concept of multiband antennas under the influence of the human body
Authors: Jung Byungwoon , Lee Hyunkyu , Byun Joonho , Won Jung Chang , Park Myun‐Joo , Chung Young‐Seek , Lee Byungje
Published: December 2008

A novel wideband antenna, consisting of a double T‐shaped element and a coaxial cable, is proposed for multiband applications including AMPS, GSM, DCS, PCS, UMTS, and WiBro bands. The proposed antenna also mitigates the degradation of an antenna performance due to the human body. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 513–515, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24086
Resonance frequency of hexagonal and half hexagonal microstrip antennas
Authors: Ray K. P. , Pandey M. D.
Published: December 2008

Closed form expressions for the accurate calculation of the resonance frequency of a hexagonal and half hexagonal microstrip antennas, based on their equivalence with rectangular microstrip antenna, have been presented. These proposed empirical formulae have been validated using simulations and experiments. Design curves, for the input impedance variation along the feed axis, have been presented for hexagonal and half hexagonal patches for two feed positions. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 448–452, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24087
A wideband GaN HEMT power amplifier based on the dual‐fed distributed structure for WiMAX applications
Authors: Lee Yong‐Sub , Lee Mun‐Woo , Jeong Yoon‐Ha
Published: December 2008

In this article, we propose a wideband GaN HEMT power amplifier (PA) based on the dual‐fed distributed structure for 2.6 GHz WiMAX applications. For a continuous wave, the distributed PA shows the wideband performance compared with the conventional balanced PA. When the distributed PA is optimized by controlling the gate bias voltages, the wideband performance over 150 MHz is achieved for a WiMAX signal with a PAR of 9.47 dB and the signal bandwidth of 28 MHz. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 574–577, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24090
Ultra‐wideband MIMO antenna with enhanced isolation
Authors: Lin Shun‐Yun , Huang Hong‐Ren
Published: December 2008

This article presents a four‐element multi‐input multi‐output (MIMO) antenna design. To enhance the mutual isolations for ultra‐wideband operation in 2–6 GHz, a circular slot antenna with a stepped ground plane was used as an element of the MIMO antenna. Such fabrications generate nonplanar connections and discontinuous interfaces between the elements and the system ground planes. This strategy effectively decreases the mutual coupling and provides 10 dB enhancements in isolation characteristics. Both theoretical and practical investigations on the adequate information for understanding the proposed antenna's characteristics are implemented and examined experimentally. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 570–573, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24091
Horseshoe‐shaped antenna for dual‐band WLAN communications with multi‐L slots
Authors: Kwak Kyung‐Sup , Choi Sun‐Ho
Published: December 2008

In this study, a novel horseshoe‐shaped antenna with multi‐L slots for 2.4/5‐GHz wireless local area network (WLAN) operations is designed and fabricated. To obtain sufficient bandwidth when return loss (RL) < −10dB, multi‐L slots are inserted (2.4 GHz) in the patch and a coaxial probe source is used. The measured result of the fabricated antenna is a 10.6% bandwidth from 2.38 to 2.51 GHz and a 28.4% bandwidth from 5.10 to 5.88 GHz (RL < −10dB), the gain 2.04–2.58 dBi. And a good radiation pattern is achieved over the WLAN band (2.4–2.484 GHz and 5.15–5.825 GHz) range. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 463–465, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24096
Effect of nonlinear wavelength scanning to Fourier transform white‐light interferometry
Authors: Jiang Yi , Tang Caijie
Published: December 2008

The effect of nonlinear wavelength scanning to Fourier transform white‐light interferometry was examined. A Mach‐Zehnder interferometer was interrogated, and the absolute optical path difference was measured. The experimental results show that the nonlinearity of the Fabry‐Perot tunable filter has no effect on the measurement. A measuring discrimination of 3 nm is achieved. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 426–432, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24097
A compact triangular patch bandpass filter
Authors: Kelly James R. , Seager Rob D.
Published: December 2008

This article describes an effective mechanism for miniaturizing a microstrip triangular patch resonator. Measurement results show that the technique can yield ∼56% size reduction. The article also provides design equations which can be used to determine the size of discontinuity required in order to achieve a specific resonant frequency. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 566–570, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24099
A method for characterization of intermodulation distortion produced in MEMS switches
Authors: Girbau D. , Pradell L. , Lázaro A. , Peyrou D. , Pons P. , Calmon P. , Plana R. , Coccetti F.
Published: December 2008

This article proposes an alternative method, based on reflection measurements, to characterize intermodulation distortion (IMD) in MEMS switches. Because of the low intermodulation level generated in MEMS switches, its characterization is problematic, requiring high‐power RF tones (high power amplifiers). Using the proposed reflection‐based method, IMD can be characterized saving up to 6 dB power when compared with that power required in a traditional 2‐tone intermodulation measurement set‐up in transmission. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 526–529, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24102
Implementation of high quality‐factor on‐chip tuned microwave resonators at 7 GHz
Authors: Melik Rohat , Demir Hilmi Volkan
Published: December 2008

We report on the design, analytical modeling, numerical simulation, fabrication, and experimental characterization of chip‐scale microwave resonators that exhibit high quality‐factors (Q‐factors) in the microwave frequency range. We demonstrate high Q‐factors by tuning these microwave resonators with the film capacitance of their LC tank circuits rather than the conventional approach of using external capacitors for tuning. Our chip‐scale resonator design further minimizes energy losses and reduces the effect of skin depth leading to high Q‐factors even for significantly reduced device areas. Using our new design methodology, we observe that despite the higher resonance frequency and smaller chip size, the Q‐factor is improved compared with the previous literature using traditional approaches. For our 540 μm × 540 μm resonator chip, we theoretically compute a Q‐factor of 52.40 at the calculated resonance frequency of 6.70 GHz and experimentally demonstrate a Q‐factor of 47.10 at the measured resonance frequency of 6.97 GHz. We thus achieve optimal design for microwave resonators with the highest Q‐factor in the smallest space for operation at 6.97 GHz. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 497–501, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24103
Low power size‐efficient CMOS UWB low‐noise amplifier design
Authors: Jhon Hee‐Sauk , Song Ickhyun , Jeon Jongwook , Koo MinSuk , Park Byung‐Gook , Lee Jong Duk , Shin Hyungcheol
Published: December 2008

The design and measurement results of 3–5 GHz fully integrated ultra‐wideband (UWB) CMOS LNA are presented. To boost the transconductance of the LNA and to reduce circuit area effectively, we eliminate a source degeneration inductor using resistive‐feedback cascode structure. The implemented UWB LNA shows peak gain of 10.8 dB, more than 10 dB of input return loss, and a noise figure of 3.3–4.2 dB from 3 to 5.1 GHz with power dissipation of 14 mW. The input P1dB and input IP3 (IIP3) at 4 GHz are about −6 dBm and +4 dBm, respectively. For low cost, the LNA has been fabricated using a 0.18‐μm thin metal CMOS process with top metal thickness of 0.84 μm. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 494–496, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24104
A bent, shorted, planar monopole antenna for 2.4 GHz WLAN applications
Authors: Su Saou‐Wen , Chang Fa‐Shian
Published: December 2008

A simple, bent monopole antenna well useful for WLAN applications in the 2.4 GHz band is presented. The monopole antenna has a rectangular radiating plate in general and is short‐circuited to a small antenna ground and an assembly plate. The assembly plate is not only used as a supporting plate for antenna installation but also regarded as antenna ground. With a low profile of the monopole and use of the coaxial‐line feed, the antenna has much flexibility in the placement inside a wireless device. Good radiation characteristics have been observed too. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 455–457, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24106
Post‐activation treatment with demecolcine improves development of somatic cell nuclear transfer embryos in pigs by modifying the remodeling of donor nuclei
Authors: Song Kilyoung , Hyun Sang‐Hwan , Shin Taeyoung , Lee Eunsong
Published: December 2008

The objective of this study was to examine the effect of cytochalasin B (CB) and/or demecolcine (Dc) on the remodeling of donor nuclei, nuclear ploidy, and development of somatic cell nuclear transfer (SCNT) and parthenogenetic (PA) pig embryos. SCNT and PA oocytes were either untreated (control), or treated with CB, Dc, or both CB and Dc after electric activation, and then cultured or transferred to surrogates. In SCNT, blastocyst formation was higher after treatment with CB and/or Dc (26–28%) than in the controls (16%). The number of oocytes that formed a single pronucleus (PN) was higher after treatment with Dc (86%) and CB + Dc (86%) than under control conditions (44%) or after treatment with CB (63%). In PA, blastocyst formation was higher after CB treatment (47%) than under control conditions (28%), while the formation of a single PN was higher after treatment with Dc (88%) and CB + Dc (84%) compared to controls (34%). The rate of formation of diploid embryos was higher after treatment with Dc and CB + Dc than under control conditions. Dc treatment resulted in a farrowing rate of 50% with 1.1% production efficiency, while controls showed a farrowing rate of 37.5% and a production efficiency of 0.7%. The results of our study demonstrate that post‐activation treatment with Dc improves preimplantation development and supports normal in vivo development of SCNT pig embryos, probably because Dc induces formation of a single PN and this leads to normal nuclear ploidy. Mol. Reprod. Dev. 76: 611–619, 2009. © 2008 Wiley‐Liss, Inc.
Investigation of relationships between transverse relaxation rate, diffusion coefficient, and labeled cell concentration in ischemic rat brain using MRI
Authors: Athiraman Hemanthkumar , Jiang Quan , Liang Ding Guang , Zhang Li , Gang Zhang Zheng , Wang Lei , Arbab Ali S. , Li Qingjiang , Panda Swayam , Ledbetter Karen , Rad Ali M. , Chopp Michael
Published: December 2008

MRI has been used to evaluate labeled cell migration and distribution. However, quantitative determination of labeled cell concentration using MRI has not been systematically investigated. In the current study, we investigated the relationships between labeled cell concentration and MRI parameters of transverse relaxation rate, R2, and apparent diffusion coefficient (ADC), in vitro in phantoms and in vivo in rats after stroke. Significant correlations were detected between iron concentration or labeled cell concentration and MRI measurements of R2, ADC, and ADC×R2 in vitro. In contrast, in vivo labeled cell concentration did not significantly correlate with R2, ADC, and ADC×R2. A major factor for the absence of a significant correlation between labeled cell concentration and MRI measurements in vivo may be attributed to background effects of ischemic tissue. By correcting the background effects caused by ischemic damage, ΔR2 (difference in R2 values in the ischemic tissue with and without labeled cells) exhibited a significant correlation to labeled cell concentration. Our study suggests that MRI parameters have the potential to quantitatively determine labeled cell concentration in vivo. Magn Reson Med, 2009. © 2008 Wiley‐Liss, Inc.
Nosologic imaging of the brain: segmentation and classification using MRI and MRSI
Authors: Luts Jan , Laudadio Teresa , Idema Albert J. , Simonetti Arjan W. , Heerschap Arend , Vandermeulen Dirk , Suykens Johan A. K. , Van Huffel Sabine
Published: December 2008

A new technique is presented to create nosologic images of the brain based on magnetic resonance imaging (MRI) and magnetic resonance spectroscopic imaging (MRSI). A nosologic image summarizes the presence of different tissues and lesions in a single image by color coding each voxel or pixel according to the histopathological class it is assigned to. The proposed technique applies advanced methods from image processing as well as pattern recognition to segment and classify brain tumors. First, a registered brain atlas and a subject‐specific abnormal tissue prior, obtained from MRSI data, are used for the segmentation. Next, the detected abnormal tissue is classified based on supervised pattern recognition methods. Class probabilities are also calculated for the segmented abnormal region. Compared to previous approaches, the new framework is more flexible and able to better exploit spatial information leading to improved nosologic images. The combined scheme offers a new way to produce high‐resolution nosologic images, representing tumor heterogeneity and class probabilities, which may help clinicians in decision making. Copyright © 2008 John Wiley & Sons, Ltd.
Absolute metabolite concentrations calibrated using the total water signal in brain 1H MRS
Authors: Brief E. E. , Moll R. , Li D. K. B. , MacKay A. L.
Published: December 2008

Magnetic resonance spectroscopy (MRS) has been coupled with a multi‐echo imaging sequence to determine the relaxation corrected signal areas of the metabolites and the tissue water. Stimulated echo acquisition mode (STEAM) spectra (TE/TM/TR 30/13.7/5000 ms) acquired from gray and white matter voxels in 43 healthy volunteers were fit using LCModel. Corresponding water signals, measured using a multi‐echo T2 imaging sequence, were fit with a Non‐Negative Least Squares algorithm. Using this approach the water area could be T1 and T2 corrected for all three water compartments: cerebrospinal fluid (CSF), intra‐ and extra‐cellular water, and myelin water. The image‐based water measurement is an improvement over spectroscopy methods because it can be more sensitive to water changes in diseased tissue. Metabolite areas were also corrected for relaxation losses. In occipital gray matter, the concentrations of Cho, Cr, and N‐acetyl aspartate (NAA) were 1.27 (0.06), 8.9 (0.3), and 9.3 (0.3) mmol/L tissue, respectively and in parietal white matter they were 1.90 (0.05), 7.9 (0.2), and 9.8 (0.2) mmol/L tissue. The Cho and Cr concentrations were different in occipital gray compared to parietal white matter (p < 0.0001 and <0.005, respectively). Copyright © 2008 John Wiley & Sons, Ltd.
An adaptive multi‐scale approach to the modelling of masonry structures
Authors: Ainsworth Mark , Mihai L. Angela
Published: December 2008

We present an adaptive multi‐scale approach for predicting the mechanical behaviour of masonry structures modelled as dynamic frictional multi‐body contact problems. In this approach, the iterative splitting of the contact problem into normal contact and frictional contact is combined with a semismooth Newton/primal‐dual active‐set procedure to calculate deformations and openings in the model structures. This algorithm is then coupled with a novel adaptive multi‐scale technique involving a macroscopic scale, which is the size of the masonry structure, and a mesoscopic scale, which is the size of the constituents (bricks, stone‐blocks), to predict appearance of dislocations and stress distribution in large‐scale masonry structures. Comparisons of the numerical results with data from experimental tests and from practical observations illustrate the predictive capability of the multi‐scale algorithm. Copyright © 2008 John Wiley & Sons, Ltd.
A finite deformation brick element with inhomogeneous mode enhancement
Authors: Mueller‐Hoeppe D. S. , Loehnert S. , Wriggers P.
Published: December 2008

In this paper we describe a new enhanced assumed strain finite element for finite deformations. The element is based on the split of the deformation of an element into a homogeneous and inhomogeneous part. The enhancement is applied to the inhomogeneous part only. For the homogeneous part a compressible Neo‐Hooke material is used, while for the inhomogeneous part linear elasticity is assumed. In several examples it is shown that the element is locking and hourglassing free as well as insensitive to initial element distortion. Copyright © 2008 John Wiley & Sons, Ltd.
Integration of singular enrichment functions in the generalized/extended finite element method for three‐dimensional problems
Authors: Park Kyoungsoo , Pereira Jeronymo P. , Duarte C. Armando , Paulino Glaucio H.
Published: December 2008

A mapping method is developed to integrate weak singularities, which result from enrichment functions in the generalized/extended finite element method. The integration scheme is applicable to 2D and 3D problems including arbitrarily shaped triangles and tetrahedra. Implementation of the proposed scheme in existing codes is straightforward. Numerical examples for 2D and 3D problems demonstrate the accuracy and convergence properties of the technique. Copyright © 2008 John Wiley & Sons, Ltd.
Approximate reanalysis in topology optimization
Authors: Amir Oded , Bendsøe Martin P. , Sigmund Ole
Published: December 2008

In the nested approach to structural optimization, most of the computational effort is invested in the solution of finite element analysis equations. In this study, the integration of an approximate reanalysis procedure into the framework of topology optimization of continuum structures is investigated. The nested optimization problem is reformulated to accommodate the use of an approximate displacement vector and the design sensitivities are derived accordingly. It is shown that relatively rough approximations are acceptable since the errors are taken into account in the sensitivity analysis. The implementation is tested on several small and medium scale problems, including 2‐D and 3‐D minimum compliance problems and 2‐D compliant force inverter problems. Accurate results are obtained and the savings in computation time are promising. Copyright © 2008 John Wiley & Sons, Ltd.
Occlusal microwear texture analysis and the diets of historical/prehistoric hunter‐gatherers
Authors: El‐Zaatari S.
Published: December 2008

With the exception of few studies, occlusal microwear of pre‐agricultural modern humans has not been documented. In this study, microwear fabrics of samples from seven historic/prehistoric hunter‐gatherer populations with known and diverse dietary habits, representing mostly meat‐eaters from different environments, arctic/tundra (Tigara from Point Hope), cold‐steppe (Fuegians) and Mediterranean (Chumash), and mixed‐diet hunter‐gatherers from tropical climates (Andamanese and Khoe‐San from Matjes River, Riet River, and Oakhurst Shelter), were analysed to better understand how dietary differences affect microwear in these groups and to establish a reasonable comparative database for interpreting fossil hominins microwear.

Significant microwear differences, related to diet and food preparation techniques, between the meat‐eaters and mixed‐diet hunter‐gatherers were detected. Finer scale differences within each of these dietary categories were also observed. Ethnographic accounts indicate that the Tigara and Andamanese ingested hard particles attached to their food as a result of their food preparation techniques; their microwear fabrics also reflect highly abrasive diets. On the other hand, as expected, the microwear signatures of the Chumash and Fuegians indicate a diet low in abrasives, reflecting their almost exclusive reliance on marine meat for subsistence and the low amounts of extraneous particles attached to this meat. The mixed‐diet Khoe‐San occupy an intermediate position between the Tigara and Andamanese on the one hand, and the Chumash and Fuegians on the other, with regard to the level of abrasives ingested. The Khoe‐San ate large amounts of hard plants, most likely responsible for abrading their enamel surface. Copyright © 2008 John Wiley & Sons, Ltd.
Gal‐3 is stimulated by gain‐of‐function p53 mutations and modulates chemoresistance in anaplastic thyroid carcinomas
Authors: Lavra Luca , Ulivieri Alessandra , Rinaldo Cinzia , Dominici Roberto , Volante Marco , Luciani Emidio , Bartolazzi Armando , Frasca Francesco , Soddu Silvia , Sciacchitano Salvatore
Published: December 2008

Galectin‐3 (Gal‐3) is an anti‐apoptotic molecule of the β‐galactoside‐binding lectin family. Gal‐3 is down‐regulated by wt‐p53 and this repression is required for p53‐induced apoptosis. Since poorly differentiated thyroid carcinomas (PDTCs) and anaplastic thyroid carcinomas (ATCs) frequently harbour p53 mutations, we asked whether Gal‐3 expression and activity could be influenced by such mutations in these tumours. We found a positive correlation between Gal‐3 expression and p53 mutation in human thyroids and in thyroid carcinoma cell lines (TCCLs) harbouring different p53 mutations. Gal‐3 was over‐expressed in most ATCs and TCCLs, especially those with the most frequently detected p53 mutation (p53R273H). Over‐expression of p53R273H in two p53‐null cells (SAOS‐2 and SW‐1736) as well as in two wt‐p53‐carrying TCCLs (TPC‐1 and K1), stimulated Gal‐3 expression, while interference with p53R273H endogenous expression in ARO cells down‐regulated Gal‐3 expression. Conversely, over‐expression of wt‐p53 in ARO cells restored the inhibitory effect on Gal‐3 expression. ARO cells are highly resistant to apoptosis and express both p53 and Gal‐3, which are increased upon cisplatin treatment. Interference with Gal‐3 expression in these cells stimulated their chemosensitivity. In conclusion, gain‐of‐function p53 mutant acquires the de novo ability to stimulate Gal‐3 expression and to increase chemoresistance in ATCs. Copyright © 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
UCH‐L1 expression of podocytes in diseased glomeruli and in vitro
Authors: Liu Yuan , Wu Jiajing , Wu Huijuan , Wang Tianzhan , Gan Hualei , Zhang Xin , Liu Ye , Li Ruixi , Zhao Zhonghua , Chen Qi , Guo Muyi , Zhang Zhigang
Published: December 2008

Ubiquitin C‐terminal hydrolase‐L1 (UCH‐L1), an important member of de‐ubiquitination enzyme families involved in the ubiquitin–proteasome pathway, is expressed mainly in neural and reproductive systems as well as in some tumours. Recently, expression of UCH‐L1 has been discovered in parietal epithelial cells of Bowman's capsules and some tubular epithelia in the kidney. However, whether UCH‐L1 is expressed in the capillary tufts of the glomeruli has not yet become clear. In this study, we used immunohistochemistry, double immunofluorescence labelling, immunoelectron microscopy in kidney biopsy tissues and western blot in cultured rat podocytes to investigate the expression of UCH‐L1 and the regulation of this expression in podocytes. The results demonstrated that UCH‐L1 was expressed in podocytes and its expression was significantly higher in acute proliferative glomerulonephritis (APGN), lupus nephritis (LN), membranous glomerulonephritis (MGN) and IgA nephropathy than that in focal segmental glomerulosclerosis (FSGS), minimal change disease (MCD), minor abnormality and normal kidney tissues (p < 0.05). In in vitro experiments, western blot showed that UCH‐L1 expression significantly increased in the two groups of podocytes co‐cultured with mesangial cells exposed to ATS 50 µl/ml and ATS 50 µl/ml with normal human serum 30 µl/ml, respectively (p < 0.05), while the other groups treated with TGFβ1 1 ng/ml, TNFα 10 ng/ml or IL‐1 10 ng/ml had little rise of UCH‐L1 expression, with no statistical significance compared with normal control (p > 0.05). Further tests indicated that the percentage of PCNA‐positive podocytes in LN, APGN and IgA nephropathy was significantly higher than that in MCD, FSGS and normal control (p < 0.05). These data show for the first time that podocytes do express UCH‐L1 and that its expression can be increased in these immunocomplex‐mediated nephrites. The immune injury is a main cause for stimulating podocytes to express UCH‐L1. The expression of UCH‐L1 may be associated with the regeneration of podocytes as a repair response to immunocomplex‐mediated injury. Copyright © 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Preparation and characterization of Pani and Pani‐Ag nanocomposites via interfacial polymerization
Authors: Bedre Mahesh D. , Basavaraja S. , Salwe Balaji D. , Shivakumar V. , Arunkumar Lagashetty , Venkataraman A.
Published: December 2008

Polyaniline (Pani) and Polyaniline‐silver nanocomposites (Pani‐Ag) were prepared by employing interfacial polymerization using ammonium persulphate as an oxidizing agent. During the polymerization, the Ag+ is reduced to Ag0, and the formations of regular nanocomposite materials were studied by Fourier transform infrared spectroscopy and UV–visible spectroscopy techniques. Scanning electron microscopy and transmission electron microscopy images were conducted to characterize the morphology. Thermogravimetric and differential thermal analysis were carried out to study the thermal stability of the resulting composites. Formation of conducting emeraldine salt form was concluded by electrical conductivity. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Structure and properties of poly(ethylene oxide)‐organo clay nanocomposite prepared via melt mixing
Authors: Abraham T.N. , Ratna D. , Siengchin S. , Karger‐Kocsis J.
Published: December 2008

Poly(ethylene oxide) (PEO)/organo clay nanocomposites were prepared by melt‐mixing using a laboratory kneader followed by compression molding. The nanocomposites were characterized by X‐ray diffraction, atomic force microscopy, and scanning electron microscopy. Their crystallization behavior in hot stage was investigated by polarized optical microscopy (POM). A decrease in size and regularity were observed as a result of incorporation of clay into the PEO matrix. The dynamic viscoelastic behavior of PEO/organo clay nanocomposites was assessed using a strain‐controlled parallel plate rheometer. The effects of clay concentration and the processing temperature on the rheological properties of the nanocomposites were extensively studied. A significant increase in the viscosity and storage modulus of the nanocomposites was found with the increasing clay content. The flow activation energy decreased with the incorporation of clay. The reinforcing effect of the organoclay was determined in dynamic mechanical analysis and tensile testing. POLYM. ENG. SCI., 2009. © 2008 Society of Plastics Engineers
Atmospheric‐Air Plasma Surface Modification of Polyethylene Powder
Authors: Píchal Jan , Hladík Jan , Špatenka Petr
Published: December 2008

The surface modification of polyethylene powder using a plasma reactor based on a dielectric barrier discharge in air at atmospheric pressure and ambient temperature is investigated. The process is inexpensive, and the necessity of any vacuum equipment and technical gases is alleviated. The efficiency of the modification process was successfully demonstrated by ESCA measurements that proved formation of new functional groups at the modified powder surface. The modification effect was also evaluated by means of dynamic capillarity rising measurements. Powder capillarity tests proved significant powder capillarity changes. The reduction of the modification effect was also limited (max. reduction of about 20% during 1 100 d after the modification date).

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Two‐dimensional gel electrophoresis and mass spectrometry for biomarker discovery
Authors: Penque Deborah
Published: December 2008

The proteome project, initiated in 1995, was made possible by 2‐DE combined with MS. The project main objective was and remains the identification of all proteins expressed by a cell, tissue or organism in a given time and condition. Following this objective, the global profiling of proteins in health versus pathological state by the 2‐DE/MS‐based proteomic approach has contributed to the elucidation of the basic mechanisms of disease by discovering candidate disease biomarkers and disease targets for new drug development. This review will briefly summarize the historical evolution of 2‐DE up to today, and review 2‐DE/MS technology and its specific methods of study of immunoresponse (immunoproteomics), PTM of proteins, complex protein–protein interactions (interactome), the proteome of cell membrane and intracellular proteome turnover in disease biomarker discovery.
Clinical screening of autonomic dysfunction in multiple sclerosis
Authors: Hale Leigh A. , Nukada Hitoshi , Du Plessis Lodewicus J. , Peebles Karen C.
Published: December 2008

Background and Purpose. Multiple sclerosis (MS) can affect the autonomic nervous system. Although exercise may be beneficial for people with MS, those with autonomic dysfunction may have altered heart rate responses to exercise. We investigated the hypothesis that the pattern of increase in heart rate on commencement of a simple cycle test would be different in those participants with MS who had been shown to have autonomic dysfunction on laboratory testing compared with both control participants and MS participants not exhibiting autonomic involvement. Method. A controlled cohort study with a volunteer sample of 31 adults with MS (26 women, 5 men) with a mean age of 46 ± 8.00 years (32–60 years), a median Expanded Disability Severity Scale of 3 (1–6) and a mean duration since diagnosis of 10.3 years (0.1–39 years). Thirty‐one age‐matched, non‐disabled, sedentary but healthy adults (26 women, 5 men) with a mean age of 45 ± 9.5 years (24–57) comprised the control group. Autonomic function was evaluated using continuous heart rate and blood pressure responses to rhythmical deep breathing, the Valsalva manoeuvre, passive postural change and a simple cycle test. Results. There were no significant differences in age, height or weight (p < 0.05) between the two groups or on any of the autonomic test results (p < 0.05). Five participants with MS (16%) had abnormal autonomic function on laboratory testing, two of whom demonstrated an abnormal heart rate response to the cycle test. Conclusions. It is suggested that physiotherapists monitor the heart rate response to a dynamic exercise test in people with MS prior to prescribing an exercise programme to ensure patients' safety. Should the response appear delayed or attenuated, referral for more formal autonomic laboratory testing is recommended. Copyright © 2008 John Wiley & Sons, Ltd.
Home or away? Community rehabilitation following traumatic brain injury: a case report
Authors: Mccormack Elaine , Liddiard Heather
Published: December 2008

Background and Purpose. A case report of AJ, a 25 year old man who had a severe traumatic brain injury and required ongoing rehabilitation. This study illustrates that community based rehabilitation can be the medium of choice to meet a client's rehabilitation needs. Method. 3 separated episodes of rehabilitation were given over a two year period. Meaningful goals were negotiated with client and main carer throughout; the supportive and effective care system provided by his family allowed abilities to be maintained and progress between sessions and episodes of care. Results. Goals were achieved in each rehabilitation episode, maintained and progressed in each treatment break, with incremental reduction in levels of dependency for AJ, and improvement in quality of life for him and his family. Conclusion. With a specialist professional team and good support network, the community is the environment of choice for rehabilitation of severely brain injured clients. Copyright © 2008 John Wiley & Sons, Ltd.
Use of information feedback and attentional focus of feedback in treating the person with a hemiplegic arm
Authors: Durham Katherine , Van Vliet Paulette M. , Badger Frances , Sackley Catherine
Published: December 2008

Background and Purpose. Feedback about motor performance can induce either an internal focus of attention (about body movement) or an external focus of attention (about the effects on the environment) in the learner. The main aim of this pilot study was to examine the attentional focus of feedback given by physiotherapists during treatment of the hemiplegic arm. A second aim was to examine the frequency of feedback about motor performance during treatment. Method. A multi‐methods design was used (quantitative and qualitative). Eight physiotherapists and eight patients with stroke were recruited from two hospitals. Data were collected by video recordings of treatment, interviews (both therapists and patients) and questionnaire (therapists). Information feedback, instructions and motivational statements were identified from the video recordings. Feedback and instructions were further grouped into internal focus, external focus or mixed focus of attention. Themes were drawn from the interview transcripts. Triangulation was used to provide corroborating information from the different data sets. Results. Two hundred and forty‐six of the total 1914 statements identified in the videos were feedback, the rest comprising instructions and statements of motivation. Of the feedback statements, 236 of the total 247 identified had an internal focus. Therapist interviews and questionnaires revealed more external focus communication than actual treatment. Conclusions. Physiotherapists used instructions and statements of motivation more than feedback and directed the patient's attention more to body movement than movement effects. The outcome of this study may prompt clinicians' to examine the amount and the attentional focus of the feedback they use in their clinical practice, and to consider whether it is a most effective approach in light of current evidence. Copyright © 2008 John Wiley & Sons, Ltd.
Virtual in vivo biopsy map of early prostate neoplasm in TRAMP mice by MRI
Authors: Kiss Pal , Eltoum Isam‐Eldin , Suranyi Pal , Zeng Huadong , Simor Tamas , Elgavish Ada , Elgavish Gabriel A.
Published: December 2008

BACKGROUND

The noninvasive, early detection of Prostate Intraepithelial Neoplasia (PIN), a precancerous neoplasia of the prostate, would be highly desirable. In our experiments, we used TRAMP mice to model PIN in the range of grade 1 through grade 4.

METHODS

Contrast enhanced pixel‐by‐pixel R1 mapping of the prostate was used to detect areas with the different prostate neoplasia grades. After anesthesia, Gd(ABE‐DTTA) was injected I.V. A series of MRI images with varying TI were then acquired to create R1 maps in a 2 mm transversal tomographic slice that included the prostate. After euthanasia and the excision of the prostate, a 2 mm slice, corresponding to the tomographic slice, was selected and prepared for histological analysis. The microscopic sections of this slice were scanned and analyzed along with the R1 maps. The R1 values were normalized to that measured in muscle tissue in each individual mouse to account for possible variations among the mice in contrast agent uptake (R1norm). The R1norm values and the histological grades in the corresponding areas were correlated.

RESULTS

A significant difference was found between the R1norm values measured in areas with grade 1–2 versus those observed in areas with grades 3–4. Also, a significant correlation was found between the area size of the ROIs differentiated by MRI, and those determined by histology.

CONCLUSION

This method has the potential for early noninvasive detection of developing prostate cancer. Prostate 69:449–458, 2009. © 2008 Wiley‐Liss, Inc.