bluuebunny/crossref_metadata_2025 huggingface dataset:
Factors predictive for long‐term survival of male patients with hepatocellular carcinoma after curative resection
Authors: Zhou Li , Rui Jing‐An , Wang Shao‐Bin , Chen Shu‐Guang , Qu Qiang , Chi Tian‐Yi , Wei Xue , Han Kai , Zhang Ning , Zhao Hai‐Tao
Published: February 2007

Background and Objectives

Curative hepatic resection (CHR) was a modality that provides possibility of long‐term survival for hepatocellular carcinoma (HCC). So far, prognostic factors of male patients with HCC after CHR remain unclear. Purposes of the present study were to identify these factors and to compare them with those for females.

Methods

Consecutive 151 male and 23 female patients with HCC undergoing CHR were enrolled in this retrospective study. Their prognostic factors were identified by uni‐ and multi‐variate statistical analysis.

Results

One‐, three‐ and five‐year overall and disease‐free survival of male patients were 82.4, 51.5, and 43.6%, and 65.8, 33.7, and 21.7%, respectively, with no significant differences compared to females. Univariate analysis showed that tumor size, TNM staging, Edmondson‐Steiner grade, serum α‐fetoprotein (AFP) level, presence of portal vein tumor thrombosis (PVTT) and satellite nodule were significant for males with HCC, but only Edmondson‐Steiner grade, presence of PVTT and satellite nodule were independent. For females, Edmondson‐Steiner grade was the single potential indicator for survival.

Conclusions

Malignant degree and invasive phenotypes were main factors that independently influenced survival of male patients with HCC after CHR. Among them, histological grade, which was also potentially significant for females, was the most powerful survival predictor. J. Surg. Oncol. 2007;95:298–303. © 2007 Wiley‐Liss, Inc.
Understanding Multicompartment Micelles Using Dissipative Particle Dynamics Simulation
Authors: Zhong Chongli , Liu Dahuan
Published: February 2007

Multicompartment micelles are a new class of nanomaterials that may find wide applications in the fields of drug delivery, nanotechnology and catalysis. Due to their structural complexity, as well as the wide parameter space to explore, experimental investigations are a difficult task, to which molecular simulation may contribute greatly. In this paper, the application of the dissipative particle dynamics simulation technique to the understanding of multicompartment micelles is introduced, illustrating that DPD is a powerful tool for identifying new morphologies by varying block length, block ratio and solvent quality in a systematic way. The formation process of multicompartment micelles, as well as shear effects and the self‐assembly of nanoparticle mixtures in multicompartment micelles, can also be studied well by DPD simulation. The present work shows that DPD, as well as other simulation techniques and theories, can complement experiments greatly, not only in exploring properties in a wider parameter space, but also by giving a preview of phenomena prior to experiments. DPD, as a mesoscopic dynamic simulation technique, is particularly useful for understanding the dynamic processes of multicompartment micelles at a microscopic level.

magnified image
Bank monitoring, managerial ownership and Tobin's Q: an empirical analysis for India
Authors: Ghosh Saibal
Published: February 2007

The paper examines how banking relationships and managerial ownership relate to firm valuation. It is argued that both the number of banking relationships (which serves as an external monitoring function) and managerial ownership (which serves as an internal monitoring function) affect firm value, while internal monitoring by managers and external monitoring by banks were viewed as substitutes or complements. After controlling for the effect of exogenous variables, the results reveal the existence of a complementary monitoring effect between banks and the managerial group. On the other hand, the results indicate that increased external monitoring by banks will simultaneously raise the incentive on the part of managers to engage in internal monitoring. Also, firm valuation is found to be a significant determinant of managerial ownership. A disaggregated analysis of firms according to size and leverage suggests the existence of a complementary monitoring effect between banks and managers, except for small‐sized firms. Copyright © 2007 John Wiley & Sons, Ltd.
Instep free flap for plantar soft tissue reconstruction: Indications and options
Authors: Scheufler Oliver , Kalbermatten Daniel , Pierer Gerhard
Published: February 2007

Pedicled instep flaps are frequently used in weight‐bearing plantar reconstruction, but may not be available after severe foot injuries. Although free instep flaps offer a viable option, they have scarcely been reported. A posttraumatic plantar forefoot defect was reconstructed with a sensate, instep free flap, because local flaps were not available and defect size did not require a distant free flap, and the current literature was reviewed for therapeutic options. The instep free flap yielded an excellent functional and aesthetic long‐term result. In the literature, pedicled instep flaps are advocated for moderate size defects of the weight‐bearing heel and sole, while free flaps from distant sites are preferred for large defects. Although skin‐grafted muscle flaps and fasciocutaneous flaps yield similar results, reconstruction by like tissues appears favorable. We suggest the instep free flap for weight‐bearing plantar foot reconstruction, when pedicled instep flaps are not available and distant free flaps are avoidable. © 2007 Wiley‐Liss, Inc. Microsurgery, 2007.
One‐stage reconstruction of complicated thumb injury with combination of microsurgical transplantations
Authors: Cong Hai‐Bo , Chang Shi‐Min , Qiao Yong‐Ping , Wang Chen‐Lin , Sui Hai‐Ming , Cong Lu
Published: February 2007

Complicated thumb loss of the hand still remains a great challenge to hand and microsurgeons. In this article, we report our technique and outcomes in 10 cases using one‐stage microsurgical procedures. In each case, three tissue transplants in combination with a sequential vascular anastomoses was performed, i.e. the second toe for the thumb, the extensor digitorum brevis for thenar opponent muscle, and the anterolateral thigh flap for the first web space, and adjacent soft tissue defects. All the transplants survived eventually. After an average of 6 years follow‐up, the results were very inspiring. Combined tissue transfer can hasten patient recovery and improve functional outcomes. However, this method needs meticulous technique and great experience in microsurgery. © 2007 Wiley‐Liss, Inc. Microsurgery, 2007.
Chimerism induction in vascularized bone marrow transplants augmented with bone marrow cells
Authors: Arslan Emrah , Klimczak Aleksandra , Siemionow Maria
Published: February 2007

Composite tissue allografts (CTAs) are currently accepted in the clinic; however, long‐term immunosuppression is still needed for allograft survival. The presence of donor‐specific chimerism may induce tolerance. Thirty‐six vascularized bone marrow transplantation (VBMT) allotransplantation were performed across MHC barrier under short‐term protocol of 7‐day αβ‐TCRmAb and Cyclosporin A therapy to determine the efficacy of VBMT alone and VBMT augmented with donor bone marrow transplantation (BMT) in chimerism induction. Flow cytometry analysis revealed that VBMT supported with donor BMT directly into the bone resulted in chimerism augmentation and maintenance compared to VBMT. In vivo and in vitro tolerance testing showed prolonged survival of donor skin graft up to 35 days and moderate reactivity in MLR assay that suggests only tolerance induction. Transplantation of vascularized bone without chronic immunosuppression provides a substantial source of bone marrow cells, leading to the development of stable donor‐specific chimerism. © 2007 Wiley‐Liss, Inc. Microsurgery, 2007.
Effects of supplementation of BH4 after prolonged ischemia in skeletal muscle
Authors: Wang Wei Z. , Fang Xin‐Hua , Stephenson Linda L. , Khiabani Kayvan T. , Zamboni William A.
Published: February 2007

Purpose: To determine whether the supplementation of tetrahydrobiopterin (BH4, an essential cofactor of nitric oxide synthase; NOS) could attenuate endothelial dysfunction and improve NOS activity and cell viability in skeletal muscle after ischemia/reperfusion (I/R). Methods:A vascular pedicle isolated rat cremaster muscle model was used. Cremaster muscles were subjected to 4 h of ischemia followed by 2 h of reperfusion. Rats were given either normal saline or BH4 by intravenous injection at 1 min prior to reperfusion. After reperfusion, average arteriole diameter, capillary perfusion, endothelial‐dependent/‐independent vasodilatation, NOS activity, and muscle cell viability were evaluated. Results: Supplementation of BH4 prior to reperfusion significantly attenuated reperfusion‐induced vasoconstriction, poor capillary perfusion, and endothelial dysfunction and enhanced cNOS activity and slightly improved cell viability in the skeletal muscle after I/R. Conclusion: Supplementation of BH4 during reperfusion provided a significant protection against I/R injury in rat skeletal muscle. © 2007 Wiley‐Liss, Inc. Microsurgery, 2007.
Using high permittivity ceramic substrates to design a bandpass filter with open stub
Authors: Huang Cheng‐Liang , Wang Jun‐Jie , Chang Yu‐Pin
Published: February 2007

The advantage of using high permittivity ceramic substrates is to miniaturize the sizes of microstrip bandpass filters. The selectivity and stopband rejection of the designed filters can be improved significantly by utilizing open stubs. The designed filter with appropriate open stub can create tunable transmission zero. These factors will reduce the size of the filter and increase its performance. The responses of the filters using Al2O3(εr= 9.8, tanδ = 0.0001) and 0.96(Mg0.95Zn0.05) TiO3‐0.04SrTiO3(εr= 20.7, tanδ = 0.00007) ceramic substrates are designed at a center frequency of 2.45 GHz. Finally, the open stub and high permittivity ceramic substrates are applied to the design of a direct‐coupled hairpin filter. The compact size, low‐loss, sharp response, and performance of the filter are presented in this article. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 771–773, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22252
A novel schema to design a compact, low loss, high rejection LTCC bandpass filter
Authors: Lee Wen‐His , Su Chi‐Yi , Yi Ching‐Chnag
Published: February 2007

A novel design of compact comb‐line LTCC filter to have three attenuation poles including two attenuation poles in the lower stopband and an attenuation pole in the higher stopband is presented. The proposed filter has been implemented in 5‐layer ceramic tapes using LTCC technology and shows very promising electric properties performance. The insertion loss is less than 2 dB from 5.15 to 5.25 GHz in passband and the rejection of filter is very shape in the passband edge. The filter with novel schema design and implementing by LTCC has been demonstrated to possess simultaneously the low insertion loss and the high attenuation EM simulation results are well agreed with the measured results. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 896–898, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22254
Compact wide stopband low‐pass filter using rectangular patch compact microstrip resonant cell and defected ground structure
Authors: Dwari Santanu , Sanyal Subrata
Published: February 2007

A new compact microstrip low‐pass filter (LPF) is presented using a novel rectangular patch compact microstrip resonant cell (RPCMRC) and square‐head defected ground structure (DGS). It exhibits wide, high stopband, and sharp rejection. A demonstration LPF having 3 dB cutoff frequency of 2.65 GHz was fabricated and measured. Measured rejection is better than 20 dB from 2.8 to 16 GHz. Electrical length of the filter is less than 20% of the guided wavelength at 3 dB cutoff frequency. Measured passband to stopband attenuation slope is more than 56 dB/GHz. Good match between experimental and simulated results are obtained. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 798–800, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22259
Design of parallel coupled‐line microstrip wideband bandpass filter using stepped‐impedance resonators
Authors: Hung Cheng‐Yuan , Weng Min‐Hang , Su Yan‐Kuin , Yang Ru‐Yuan
Published: February 2007

In this article, a parallel coupled‐line microstrip wideband bandpass filter (PCM‐WBF) using stepped‐impedance resonators (SIRs) is designed and implemented on commercial printed circuit board (PCB) of RT/Duroid 5880 substrate. The first two resonant modes of the SIR are coupled together and they are applied to create a wide passband. The proposed filter at center frequency f0 of 5.76 GHz has very good measured characteristics including a bandwidth of 3.63–7.92 GHz (3‐dB fractional bandwidth of 74%) and a low insertion loss of −1 ± 0.9 dB. Experimental results of the fabricated filter show a good agreement with the predict results. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 795–798, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22260
Fiber optic displacement sensing monitored by an OTDR and referenced by Fresnel reflection and by fiber Bragg gratings
Authors: Mendonça S. , Frazão O. , Baptista J. M. , Santos J. L.
Published: February 2007

This work presents a study of displacement sensing based on a fiber eight geometry shape monitored by an optical time domain reflectometer. The displacement sensor is referenced by Fresnel reflection or by a fiber Bragg grating structure located after the sensor. One of the advantages of the fiber Bragg grating as referencing device is its capability to be multiplexed by a number of displacement sensors in series along the optical fiber. This concept is also demonstrated using two Bragg gratings. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 768–770, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22261
Double‐cladding Yb3+ fiber for free‐space optical communication
Authors: Kong Yong , Wang Chunyu
Published: February 2007

The experiment result of Nd:YVO4 laser pumped by laser diode that was amplified by double‐cladding Yb3+ fiber is reported. Stable mode‐locking pulses are obtained at repetition rate of 320 MHz and the output power is 15 mW. When laser power is amplified by Yb3+‐doped double‐cladding fiber amplifier, its power can get to 600 mW. Based on these, experiment of double‐frequency is carried out, and green laser with power of 4 mW is obtained. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 889–892, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22264
Using efficient ray‐tracing techniques to predict propagation losses in indoor environments
Authors: Alves F. A. , Albuquerque M. R. M. L. , Silva S. G. , d'Assunção A. G.
Published: February 2007

This paper addresses an efficient implementation of the 2.5D ray‐tracing propagation model to predict propagation losses in indoor environments. The analysis is based on the Shooting and Bouncing Rays technique and Uniform Theory of Diffraction. Besides the line‐of‐sight propagation, we consider that the radio waves may experience reflection, refraction, and diffraction (NLOS). The simulated results are validated by the measurement carried out in a teaching building at 1.8 GHz. Validation is also provided by comparisons with published data. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 854–858, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI.10.1002/mop.22266
Microstrip‐line‐fed rectangular microstrip antenna with open end meandering slots in the ground plane for compact broadband operation
Authors: Kiran Usha , Vani R. M. , Yadahalli Ravi M. , Hunagund P. V. , Farida Sara F.
Published: February 2007

In this paper, microstrip‐line‐fed rectangular microstrip antenna with open‐end meandering slots in the ground plane for compact broadband operation is presented. The proposed design consists of a rectangular patch which is fed by a 50‐Ω center fed microstrip‐line feed. Three identical narrow open‐end meandering slots were embedded in the antenna's ground plane parallel to the rectangular patch's radiating edge. Experimental study is carried out by varying the length of the open‐end meandering slots. Using open‐end meandering slots in the ground plane, the resonant frequency of the antenna is greatly lowered with large enhancement in bandwidth when compared with conventional microstrip antenna. With the proposed design, an extreme reduction of 82.9% in the antenna size is obtained with a wide bandwidth of 40%. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 824–827, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22267
Internal meandered loop antenna for GSM/DCS/PCS multiband operation in a mobile phone with the user's hand
Authors: Lin Chun‐I , Wong Kin‐Lu
Published: February 2007

A novel internal meandered loop antenna for application in a mobile phone for Global System for Mobile Communication/Digital Communication System/Personal Communication System (GSM/DCS/PCS) multiband operation is presented. Along the symmetric metal‐strip loop structure of the antenna, there are meandered sections for adjusting the antenna's resonant frequencies and widened sections for improving the impedance matching. The antenna's first and second resonant modes (half‐ and one‐wavelength modes) excited at about 900 and 1800 MHz for GSM/DCS operation. With the meandered sections in the loop structure, the antenna's third resonant mode (1.5‐wavelength mode) can be adjusted to be close to the second resonant mode at 1800 MHz to achieve a wider upper band for DCS/PCS operation. In addition, the central region of the proposed loop antenna is unoccupied, which can be used to accommodate possible nearby electronic components, such as the lens of a digital camera. Furthermore, effects of the user's hand holding the mobile phone with the proposed loop antenna are analyzed in this study. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 759–765, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22271
Broadband coplanar waveguide‐fed slot antenna for wireless local area networks and microwave imaging applications
Authors: Ali Mohammod , Tailor Ashit
Published: February 2007

A broadband CPW‐fed semicircular slot antenna is proposed for 2–6 GHz WLAN (wireless local area networks) and microwave imaging applications. The total dimension of the bidirectional slot antenna is 80 mm by 50 mm and is designed on a 0.5‐mm‐thick Duroid 5880 substrate (dielectric constant = 2.2). The antenna operates from 2 to 6 GHz within VSWR of 2.5:1. The same antenna on a combination rectangular cylindrical cavity with cavity depth of 10 mm provides a directional beam, 11 dB front‐to‐back (F/B) ratio and a bandwidth of 63% (2.8–5.4 GHz). © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 846–852, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22276
A CMOS wideband linear‐in‐dB VGA for UWB applications
Authors: Lee Hui Dong , Lee Kyung‐Ai , Hong Songcheol
Published: February 2007

A CMOS wideband variable gain amplifier (VGA) with an exponential gain control characteristic is presented. The exponential gain control function is realized by changing the tail currents a differential gain stage. The bandwidth is extended by using an inductive peaking technique. The gain (in dB) of the VGA is varied linearly from −41 dB to 31 dB with respect to a control voltage from 1.38 V to 1.1 V. The bandwidth of the proposed VGA is larger than 1 GHz with a gain control range of 72 dB. A DC offset cancellation loop is included so as to avoid amplification of the DC offset. The VGA is powered by 1.8 V with 13.5 mA. The VGA chip occupies an area of 220 μm × 620 μm. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 812–817, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22278
Compact angularly stable AMCs utilizing skewed cross‐shaped FSSS
Authors: Hosseini M. , Pirhadi A. , Hakkak M.
Published: February 2007

This paper presents an innovative methodology for designing three new Artificial Magnetic Conductors (AMC) with very little sensitivity to the angle of incidence and compact size. The AMC structures are composed of a Frequency Selective Surface (FSS) placed at the interface of a metal‐backed dielectric slab. The FSSs used belong to the family of Skewed Crosses (SC). The paper begins by investigating the properties of a GA‐designed AMC presented in a previous literature. After that, a basic SC‐based AMC is extracted from this AMC and is modified step by step to improve the desired features. The modifications are performed not based on time‐consuming optimization methods, but by utilizing the theoretical clues presented in another literature for similar structures. Taking these strategies, such AMCs are obtained that have very good angular stability, compact size, and acceptable bandwidth. Periodic Method of Moments (PMM) is used to analyze and study the proposed periodic structure. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 781–786, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22280
A broadband microstrip Marchand balun with vertical coupling structure
Authors: Nam Hee , Yun Tae‐Soon , Lee Jong‐Chul
Published: February 2007

In this paper, a broadband microstrip Marchand balun is presented. It is implemented by new vertical coupled structure, which is suggested to improve the coupling effect in the conventional coupler. Using this vertical coupling structure, the Marchand balun shows broad bandwidth of larger than 115% at the center frequency of 2.3 GHz. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 752–755, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22281
Tunable flat‐top fiber Bragg grating filters fabricated in hydrogen‐loaded graded‐index multimode fibers
Authors: Fu Hong‐Yan , Liu Wei‐Sheng , Shao Li‐Yang
Published: February 2007

We propose an experimental realization of flat‐top filters by fabricating fiber Bragg gratings in graded‐index multimode fibers (GI‐MMF). Two types of GI‐MMFs were used to make this kind of filters, and their spectra and polarization properties were experimentally investigated. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 841–843, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22286
Planar monopole antenna with wide impedance bandwidth for mobile handset application
Authors: Kim Wonseob , Hong Seokjin , Park Hoon , Choi Jaehoon
Published: February 2007

Design of a planar monopole antenna with wide impedance bandwidth characteristic for mobile handset application is presented. To enhance the impedance bandwidth characteristic, a beveling technique has been implemented on the radiating patch and two notches are formed along the edge of the ground plane. The proposed antenna has 10 dB return loss impedance bandwidth of about 9.8 GHz (1.66–11.5 GHz). © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 779–781, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22289
Mutual coupling study on meander line antenna elements for use in active‐phased array
Authors: Beenamole K. S. , Kutiyal Prem N. S. , Revankar U. K. , Pandharipande V. M.
Published: February 2007

Mutual coupling study has been carried out on microstrip Meander line antenna elements for use in active‐phased array radars. The basic Meander line antenna element has been designed to obtain linear horizontal polarization with a wide bandwidth and wide beamwidth in S‐band frequency. The elements are fabricated on a low cost glass epoxy (FR4) substrate with array interelement spacing of approximately half wavelength. The mutual coupling study has been carried out in a linear and planar array environment and the results show no performance degradation of the array element impedance and patterns due to mutual coupling. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 745–749, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22291
A 2.4 GHz ultra low power subthreshold CMOS low‐noise amplifier
Authors: Meng Lim Kok , Yong Ng Choon , Seng Yeo Kiat , Anh Do Manh
Published: February 2007

A 2.4 GHz subthreshold CMOS low‐noise amplifier (LNA) employing current‐reuse technique is presented for the first time. The circuit measuring 1050 × 723 μm2is designed using CHRT's 0.18 μm RF CMOS technology. With the push–pull configuration, the amplifier simulated using Spectre® has a gain of 9.8 dB, IIP3 of −2.7 dBm, and NF of 3.6 dB, while consuming a mere 650 μA from a 1 V supply. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 743–744, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22292
Comparison of two wavelength conversion schemes by exploiting cascaded harmonic and difference frequency generation in PPLN
Authors: Luo Chuanhong , Sun Junqiang , Wang Jian
Published: February 2007

The comparison of two wavelength conversion schemes under the continuous‐wave (CW) and pulsed pumping condition based on cascaded harmonic and difference frequency generation is theoretically analyzed and experimentally demonstrated using a periodically poled lithium niobate waveguide. The difference of bit‐transferring road and conversion process between two schemes loads to the difference of the spectrum and waveform of converted pulse. The CW pumping wavelength conversion presents a good performance in copying the spectrum, waveform, bit rate, and phase of the information carried by signal wavelength onto converted wavelength. In pulsed pumping wavelength conversion the spectrum change and waveform distortion of converted pulse occurs due to group velocity mismatch between pump, second harmonic, and converted pulse, so the pulsed pumping wavelength conversion is only a process that converted pulses replicate the bit rate of signal pulses. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 905–910, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22293
All‐optical on–off switch based on bismuth‐based highly nonlinear fiber
Authors: Qureshi K. K. , Wai P. K. A. , Tam H. Y. , Chao L. , Sugimoto N.
Published: February 2007

We propose a simple and compact all‐optical on–off switch working at 10 Gb/s. The operation of the switch is based on four‐wave mixing in only 1.9 m of bismuth‐based highly nonlinear fiber. The proposed switch has a fast response time, high ON/OFF switching ratio, and potential to work beyond 10 Gb/s. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 838–841, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22295
Analytical model for electromagnetic bandgap structures embedded in power/ground plane
Authors: Wu Xin
Published: February 2007

This study presents an analytical model to calculate the stop band of the electromagnetic bandgap (EBG) materials embedded in PCB power/ground plane to mitigate power/ground plane noise. By treating the EBG structure as lumped elements at each unit, the currents flowing through the EBG patches may be analytically computed for the modes in the power/ground plane. An analytical model is derived based on the superposition of the local EBG currents' effects on the modal field distribution in the substrate. Comparisons with measurements are also presented to validate the derived model. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 835–838, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22296
Novel rectangular waveguide resonant cavity constructed in dielectric substrate with arc corners
Authors: Wang Dapeng , Che Wenquan , Yung Edward K. N.
Published: February 2007

A novel substrate‐integrated waveguide resonant cavity with four‐arc corners has been investigated, which is constructed into the thin dielectric substrate. The theoretical length equivalence formulas for the resonant cavity have been obtained on the basis of analytical method of moment. It has been found that the resonant frequency can be kept constant when the shape factor of the cavity is small. On the other hand, the resonant frequencies of the cavity can also be tuned a little when the shape factor of the cavity is big. The empirical formula of resonant frequencies for the cavity with arc corners has been obtained. Several resonant cavities with different radius of arc corners have been designed and fabricated to demonstrate the proposed theoretical analysis. Good agreement can be observed between the theoretical analysis and experiments. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 804–808, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22297
The design of a compact quasi‐elliptic filter using stepped impedance resonators with harmonic suppression
Authors: Chen Yu‐Wei , Ho Min‐Hua , Liu Yen‐Ju
Published: February 2007

A bandpass filter is designed at 2.4 GHz using two end‐connected quarter‐wavelength stepped impedance resonators. The quarter‐wavelength stepped impedance resonators having one end shorted are formed by a half‐wavelength stepped impedance resonator with its middle shorting to ground. The modes that the shorted‐end λ/4 stepped impedance resonator supports are the (1 + 2n)/4. An enhanced U‐shape coupling feed is adopted in the filter design to reduce the insertion losses as well as to suppress the first higher harmonic. A dual‐path design is implemented in the proposed filter to create a quasi‐elliptic frequency response. The equivalent circuit model is developed and the experiments are conducted for circuit design verification. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 800–804, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22298
An improved approximate gain formula for conical horn
Authors: Tan Chin Yeng , Selvan Krishnasamy T.
Published: February 2007

The conical horn gain is expected to increase with increasing flare angle until it reaches a maximum and then should decrease. The available closed‐form approximation for conical horn loss factor, and hence gain, is examined in this paper in this background. It turns out that this approximation is not consistent with the normal conical horn gain pattern for aperture phase deviation s > ∼ 0.5. A new approximation is presented based on available data that results in “normal” gain pattern, and also improves the accuracy of the predicted gain values. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 971–973, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22300
Compact ultrawideband wide‐slot antenna
Authors: Kong K. C. , Luk K. M. , Lau K. L.
Published: February 2007

A printed wide‐slot antenna for portable ultrawideband application is presented in this article. It consists of a staircase‐shape patch and an arc‐shape slot etched on different sides of a thin microwave substrate. By using a microstrip feedline with matching stubs to excite the patch and placing a thin conductor‐backed absorber under the slot, wide impedance bandwidth (SWR < 2) of 132.8% and broadside radiation patterns are obtained. This antenna has a peak gain and an average gain of 4.7 and 3.7 dBi, respectively. Moreover, it has a low profile of 0.18λ, where λ is the free space wavelength referring to the center frequency of the operating bandwidth. The antenna is very suitable for the portable devices of nowadays UWB wireless communication systems. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 968–971, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22304
Design of a 3–5‐GHz ultrawideband BiFET mixer using 0.35‐μm SiGE BiCMOS technology
Authors: Ruifeng Song , Huailin Liao , Ru Huang , Yangyuan Wang
Published: February 2007

A fully integrated ultrawideband (UWB) bipolar cascode with metal oxide semiconductor field effect transistor (BiFET) mixer using standard commercial 0.35‐μm silicon germanium bipolar complementary metal oxide semiconductor technology was first proposed and fabricated in this study. This presented BiFET mixer using bipolar junction transistor as the transconductor stage and metal oxide semiconductor field effect transistor as the switch stage to achieve noise power and linearity trade‐off. This 3–5‐GHz UWB mixer achieves a conversion gain of 4.5 ± 0.5 dB at the designed band. The mixer core draws a current of 2.5 mA from a supply voltage of 3 V, while consumes chip area of 0.9 × 0.9 mm2. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 965–968, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22305
Wide band low profile linear microstrip antenna array with cosecant square‐shaped beam pattern
Authors: Kedar Ashutosh , Kutiyal Prem N. S. , Garg M. , Revankar U. K.
Published: February 2007

A wide band, low profile linear microstrip antenna array with cosecant square‐shaped beam pattern is presented. Array synthesis has been done using Orchard Elliott's and genetic algorithm methods. An air‐dielectric U‐slot rectangular patch element has been chosen as an array element for wide bandwidth. Simulated results have shown a good agreement with the measured results of the antenna array realized over 15% bandwidth in L‐band. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 963–965, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22309
Electromagnetic assessment on human safety of RFID system at Hong Kong International Airport
Authors: Fung L. C. , Chan K. H. , Lam W. K. , Leung S. W. , Wong Y. F. , Wu Paul W. K. , Tang C. K.
Published: February 2007

Radio Frequency Identification (RFID) technology has been widely used in different business sector. Recently, Hong Kong International Airport has adopted the RFID technology, replacing the traditional infra‐red bar code system with a new 900 MHz RFID baggage handling system. Besides the technological challenges in the design and the installation, safety issue of workers due to the radiated emission from the RFID system is also an important concern. An electromagnetic assessment of the RFID system is carried out in the post‐installation phase, and is presented here. The result shows that the in‐situ E‐field level recorded for the whole system is well below the ICNIRP guideline reference level. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 924–928, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22311
Analysis and design of class E power amplifier with nonlinear parasitic capacitance at any duty ratio
Authors: Zhang Hao , Ma Xikui , Wong Siu Chung , Tse Chi K.
Published: February 2007

The nominal operating condition of Class E power amplifiers with parallel‐connected nonlinear parasitic capacitance and linear capacitance at any duty ratio has been studied in this article. Basic design equations are derived analytically. Using these equations, the component values for ensuring nominal operation at any given duty ratio can be conveniently found. Furthermore, the design equations highlight several important practical constraints, which help develop effective designs for improving the performance of practical Class E amplifiers. Finally, a design example is provided for verification. Both PSPICE simulation and experimental measurements are presented. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 920–923, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22312
A novel LTCC patch filter with sharp transition bands
Authors: Deng Jianhua , Wang Bing‐Zhong , Gan Tiguo
Published: February 2007

A novel compact low temperature co‐fired ceramic (LTCC) patch filter is designed with sharp transition bands. The design is based on modified resonators, which can be used to provide transmission zeros located at arbitrary stopband frequency. Simple design procedure of the filter is also described. Good simulation and experimental results are obtained with insertion loss 1.2 dB and return loss of 15 dB at passband. This filter has a compact size of 2.5 mm × 4 mm. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 989–991, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22313
Compact meander monopole antenna for tri‐band WLAN application
Authors: Zhang Li‐Na , Zhong Shun‐Shi , Liang Xian‐Ling , Li Chun‐Hui
Published: February 2007

A novel printed meander monopole antenna for tri‐band wireless local area network (WLAN) applications is presented. The antenna is composed of a meander strip and a straight strip with a gap between the ends of them, both printed on an inexpensive FR4 substrate, and is fed by a 50 Ω microstrip feeder with the notched ground plane. The operation bandwidth of the proposed antenna covers 2.4, 5.2, and 5.8 GHz WLAN bands with light weight and compact radiator size of only 12 × 7 mm2. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 986–988, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22314
Novel electromagnetic bandgap‐fed tri‐band coplanar slot antenna
Authors: Ooi B. L.
Published: February 2007

A novel tri‐band electromagnetic bandgap (EBG) fed coplanar slot antenna is proposed and adopted for this investigation. With the integration of the EBG as an impedance matching element, a wider impedance bandwidth response is obtained for all the bands. Analytical expression for designing the coplanar EBG unit cells are derived for the first time. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 954–960, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22315
Pearson‐IV type doping distribution‐based analytical modeling of dual‐material double‐gate fully‐depleted silicon‐on‐insulator MOSFET
Authors: Kushwaha Alok , Pandey Manoj K , Gupta A. K
Published: February 2007

A new two‐dimensional model for dual material double gate fully depleted SOI MOSFET is presented. An investigation of potential distribution in the silicon film is carried out with Pearson‐IV type doping distribution as it is essential to establish proper profiles to get the optimum performance of the device. The proposed structure is such that the work function of the gate metal (both sides) near the source is higher than the one near the drain. The analytical model so developed shows a step‐function in the potential along the channel, which screens the drain potential variation by the gate near the drain thereby suppressing the short channel effects (SCEs). The results predicted by the model are compared with those obtained by 2‐D device simulator ATLAS to verify the accuracy of the proposed model. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 979–986, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22319
Performance of LDPC‐coded optical on‐off keying communication systems
Authors: Tseng Shu‐Ming , Hsieh Chih‐Hung , Wang Yung‐Chung , Tsai Fu‐Hsiang , Lin Kuen‐Cherng
Published: February 2007

In this letter, we study the performance of low‐density parity‐check (LDPC) codes in a Poisson optical channel with on–off keying modulation. We modify the iterative decoding algorithm used in binary phase‐shift keying modulation and additive white Gaussian noise channels. The simulation results show that the LDPC codes has performance improvements over parallel concatenated convolutional codes. Therefore, LDPC codes is well suited for optical channels with signal energy constraints. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 976–979, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22320
Internal shorted monopole antenna for the watch‐type wireless communication device for Bluetooth operation
Authors: Wu Chih‐Hsien , Wong Kin‐Lu , Lin Yuan‐Chih , Su Saou‐Wen
Published: February 2007

An internal shorted monopole antenna suitable to be embedded within the watch‐type wireless communication device is presented. The antenna generally has a planar configuration and is mounted conformal along the side surfaces of the wireless device to operate as an internal or concealed antenna. The antenna also shows a low profile of 4 mm only, yet providing a wide bandwidth for Bluetooth operation in the 2.4 GHz band (2400–2484 MHz). In addition, the antenna is designed to be short‐circuited to an upper ground plane mounted above the main system ground plane of the wireless device. With the proposed arrangement, reduced coupling between the antenna and the nearby lossy medium can be achieved. Hence, when the wireless device with the proposed antenna is worn around the user's wrist or forearm, which functions as a lossy medium, the antenna's radiation efficiency can still reach about 50% over the operating band. Details of the proposed antenna and the promising watch‐type wireless communication device are presented. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 942–946, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22322
Genes, language development, and language disorders
Authors: Smith Shelley D.
Published: February 2007

Genetic factors are important contributors to language and learning disorders, and discovery of the underlying genes can help delineate the basic neurological pathways that are involved. This information, in turn, can help define disorders and their perceptual and processing deficits. Initial molecular genetic studies of dyslexia, for example, appear to converge on defects in neuronal and axonal migration. Further study of individuals with abnormalities of these genes may lead to the recognition of characteristic cognitive deficits attributable to the neurological dysfunction. Such abnormalities may affect other disorders as well, and studies of co‐morbidity of dyslexia with attention deficit disorder and speech sound disorder are helping to define the scope of these genes and show the etiological and cognitive commonalities between these conditions. The genetic contributions to specific language impairment (SLI) are not as well defined at this time, but similar molecular approaches are being applied to identify genes that influence SLI and comorbid disorders. While there is co‐morbidity of SLI with dyslexia, it appears that most of the common genetic effects may be with the language characteristics of autism spectrum disorders rather than with dyslexia and related disorders. Identification of these genes and their neurological and cognitive effects should lay out a functional network of interacting genes and pathways that subserve language development. Understanding these processes can form the basis for refined procedures for diagnosis and treatment. © 2007 Wiley‐Liss, Inc. MRDD Research Reviews 2007;13:96–105.
Word‐attack skills in individuals with mental retardation
Authors: Saunders Kathryn J.
Published: February 2007

This article assesses the state of the literature on word‐attack skills and phonological awareness (PA) in individuals with mental retardation, in light of progress towards the development of effective teaching procedures. The literature contains promising findings. Studies have shown PA to be correlated with word‐attack skills in individuals with mental retardation, as has been shown conclusively in typically developing children. This suggests that instruction in PA would facilitate the acquisition of word‐attack skills in individuals with mental retardation, as it does with typically developing children. As of yet, however, very few experimental studies designed to demonstrate effective teaching procedures for PA and word‐attack skills have been published. This research field might evolve most effectively and efficiently by following a two‐step research program. First, test new teaching procedures in a series of small‐N studies, each study incorporating modifications of teaching procedures based on the results of the previous study. Once procedures prove effective at this level, the resources necessary to pursue large‐scale studies can be used to their best advantage. © 2007 Wiley‐Liss, Inc. MRDD Research Reviews 2007;13:78–84.
Differential treatment intensity research: A missing link to creating optimally effective communication interventions
Authors: Warren Steven F. , Fey Marc E. , Yoder Paul J.
Published: February 2007

Research over the past 50 years has yielded several promising approaches and many specific intervention techniques designed to enhance the communication and language development of young children with intellectual and developmental delays and disabilities. Yet virtually no systematic research has been conducted on the effects of different treatment intensities. We review how intervention intensity has been defined in the literature and propose a set of terms borrowed from medicine that are intended to capture the dynamic aspects of this concept as an aid to further investigation. On the basis of this approach, we propose four types of knowledge that can be generated through the systematic study of treatment intensity and discuss appropriate methods for investigating the effects of differential treatment intensities. We conclude with three recommendations for the field. © 2007 Wiley‐Liss, Inc. MRDD Research Reviews 2007;13:70–77.
Language development and fragile X syndrome: Profiles, syndrome‐specificity, and within‐syndrome differences
Authors: Abbeduto Leonard , Brady Nancy , Kover Sara T.
Published: February 2007

Fragile X syndrome (FXS) is the leading inherited cause of mental retardation. In this article, we review what is known about the language and related problems of individuals with FXS. In doing so, we focus on the syndrome‐specific features of the language phenotype and on the organismic (i.e., genetic and individual neurocognitive and behavioral) and environmental factors associated with within‐syndrome variation in the phenotype. We also briefly review those aspects of the behavioral phenotype of FXS that are relevant for understanding syndrome‐specific features of, and within‐syndrome variability in, language. The review includes summaries of research on the prelinguistic foundations for language development and on each of the major components of language (i.e., vocabulary, morphosyntax, and pragmatics). Throughout the review, we point out implications of existing research for intervention as well as directions for future research. © 2007 Wiley‐Liss, Inc. MRDD Research Reviews 2007;13:36–46.
Partial k‐space reconstruction in single‐shot diffusion‐weighted echo‐planar imaging
Authors: Storey Pippa , Frigo Fred J. , Hinks R. Scott , Mock Bryan J. , Collick Bruce D. , Baker Nicole , Marmurek Jonathan , Graham Simon J.
Published: February 2007

Partial k‐space sampling is frequently used in single‐shot diffusion‐weighted echo‐planar imaging (DW‐EPI) to reduce the TE and thereby improve the SNR. However, it increases the sensitivity of the technique to bulk rotational motion, which introduces a phase gradient across the tissue that shifts the echo in k‐space. If the echo is displaced into the high spatial frequencies, conventional homodyne reconstruction fails, causing intensity oscillations across the image. Zero‐padding, on the other hand, compromises the image resolution and may cause truncation artifacts. We present an adaptive version of the homodyne algorithm that detects the location of the echo in k‐space and adjusts the center and width of the homodyne filters accordingly. The adaptive algorithm produces artifact‐free images when the echo is shifted into the high positive k‐space range, and reduces to the standard homodyne algorithm in the absence of bulk motion. Magn Reson Med 57:614–619, 2007. © 2007 Wiley‐Liss, Inc.