bluuebunny/crossref_metadata_2025_split huggingface dataset:
A wideband Gilbert cell mixer with an integrated Marchand balun using 0.5‐μm GaAs enhancement‐mode pHEMT technology
Authors: Fu Jeffrey S. , Kuo Che‐Yu , Lin Shao‐Wei , Ke Po‐Yu , Chiu Hsien‐Chin 
Published: March 2010

AbstractIn this study, a fully integrated active Gilbert cell mixer with two Marchand baluns was proposed.The proposed circuit was designed at 12 GHz with bandwidth from 7.5 to 19 GHz and fabricated in a 0.5‐μm pHEMT process. In addition, the “current bleeding” technique was also provided in the Gilbert cell mixer to boost the conversion gain. The greatest conversion gain of 4.5 dB can be achieved in the designed circuit under LO input power of −2 dBm. Both RF‐IF and LO‐IF isolations were better than 30 dB. The third order intercept point input power, IIP3, achieved as high as 2 dBm. The mixer works from 7.5 to 19 GHz. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1302–1306, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25174
Miniaturized band‐pass filters using closed‐loop microstrip ring resonator with parallel‐coupled feed
Authors: Athukorala L. , Budimir D. 
Published: March 2010

AbstractNovel compact band‐pass filters and diplexer using microstrip ring resonator with parallel‐coupled feed are presented. Overall size reductions depend on the amount of meandering used and 56% size reduction is achieved. The proposed filters and diplexer are designed and tested. The experimental and simulation results are presented to validate the argument. Good agreement between simulated and measured result is observed. The filters and diplexer are relatively easy to manufacture and are very suitable for broadband communication systems where size and weight minimization are essential. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1277–1280, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25188
Design of a broadband balun based on composite right/left handed structure
Authors: Cao Weiping , Guo Feng , Wang Bingzhong 
Published: March 2010

AbstractA new printed Wilkinson balun based on the nonlinear phase characteristics of composite right/left handed (CRLH) structure is presented.The new device, which differs from the traditional CRLH balun, is composed of a Wilkinson power divider, a distributed CRLH transmission line (TL), and a conventional TL. It can be easily applied to MIC/MMIC circuits. Full‐wave simulations and measurement results verify the effectiveness of the new structure. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1310–1313, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25189
Characteristics of a 60 GHz MMIC mixer with an open stub microstrip line
Authors: Lee Sang‐Heung , Lim Jong‐Won , Ahn Hokyun , Chang Woojin , Ji Hong Gu , Kim Haecheon , Nam Eun Soo 
Published: March 2010

AbstractIn this article, 60 GHz MMIC down‐conversion mixers for a 60 GHz communication system are designed and fabricated on‐chip using a 0.12 μm GaAs PHEMT process technology with an fT of 78 GHz and fmax of 190 GHz.The characteristics of a 60 GHz monolithic cascode mixer with an open stub microstrip line are compared with those of a 60 GHz monolithic cascode mixer without an open stub microstrip line, which are integrated on‐chip including matching and bias circuits. The 60 GHz monolithic cascode mixer with an open stub microstrip line measured at RF 60 GHz show a conversion gain of −16 dB, LO to RF isolation of 21.5 dB, and LO to IF isolation of 40.5 dB. Especially in the case of the mixer, the LO to IF isolation characteristic is much better than that of the 60 GHz monolithic cascode mixer without an open stub microstrip line. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1341–1345, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25191
Drain efficiency amplifier of 50% with optimized power range for CDMA base station
Authors: Zheng Guangming , Lin Weigan 
Published: March 2010

AbstractA novel high‐efficiency Doherty amplifier is presented here.A carrier amplifier and a peak amplifier are set to asymmetrical drain voltages to extend the power range where a high efficiency of the amplifier is maintained. In Doherty amplifier, matching circuits of the carrier amplifier and peak amplifier are designed for each drain voltage so that the efficiency and signal linearity of the amplifier at a 7.2 dB back‐off point from its saturated output power become higher than those of a conventional amplifier. A Doherty amplifier containing laterally‐diffused metal‐oxide semiconductor field‐effect transistors achieves an adjacent channel leakage power ratio of −30.89 dBc and a drain efficiency of 50% at an output power of 49.3 dBm. This is the highest drain efficiency of a Doherty amplifier for a CDMA signal to the best of the authors' knowledge. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1244–1246, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25195
A coupling‐fed multiband antenna for WLAN/WiMAX applications
Authors: Zuo Shaoli , Yin Yingzeng , Zhang Zhiya 
Published: March 2010

AbstractA coupling‐fed printed monopole antenna applied to wireless local area network/worldwide interoperability for microwave access (WLAN/WiMAX) applications is proposed. By using a pair of branch‐shaped strips, which are symmetrical with a gradual changing strip, the proposed antenna exhibits multiband performance to meet the requirements of WLAN in the 2.4/5.2/5.8 GHz bands and WiMAX in the 2.5/3.5/5.5 GHz bands. The proposed antenna has good omnidirectional radiation characteristic owing to its symmetric structure and achieves gains to be 2.44, 3.74, 3.3, and 2.02 dBi at 2.4, 3.5, 5.2, and 5.8 GHz, respectively. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1283–1286, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25197
Methodology for all‐fiber optical active devices by composing the stimulated Brillouin scattering spectra
Authors: Galindez C. A. , Madruga F.J. , López‐Higuera J. M. 
Published: March 2010

AbstractThe methodology for reshaping and enlarging the Brillouin gain spectral response is proposed in this article as a technique to develop all‐fiber optical active devices. It is based on the superposition of the Brillouin scattering spectra from several optical fibers, which are connected in serial, parallel, or both. Additionally, the overall Brillouin gain spectral response can be tailored or customized by tuning the temperature or the strain on the fiber. To experimentally demonstrate the method, we propose a fiber device with a tailored like “W” spectral response. The bandwidth is 190 MHz at 3 dB, centered in 10.765 GHz from the pump wavelength. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1316–1318, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25199
Optical fiber arterial pulse wave sensor
Authors: Eom Sunghoon , Park Jaehee , Lee Jonghun 
Published: March 2010

AbstractAn optical fiber arterial pulse wave sensor is proposed using an in‐line Michelson interferometer that is a hollow optical fiber spliced to a single‐mode fiber at one end and cleaved at the other end. The proposed optical fiber arterial pulse wave sensor consists of an in‐line Michelson interferometer and steel reinforcement enclosed in a heat‐shrinkable tube. The sensor was directly attached onto a wrist and signals corresponding to arterial pulse waves successfully obtained. The signal‐to‐noise ratio of the sensor signals was better than 20 dB. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1318–1321, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25200
Concurrent dual‐band six‐loop‐antenna system with wide 3‐dB beamwidth radiation for MIMO access points
Authors: Su Saou‐Wen 
Published: March 2010

AbstractA high‐gain, wide‐beamwidth, six‐loop‐antenna MIMO system suited for wireless access points in the concurrent WLAN 2.4 and 5 GHz bands is presented.The antenna system mainly comprises an antenna ground plane and single‐band loop antennas, among which the three antennas are designated for 2.4 and 5 GHz operation, respectively. The antennas are set in a sequential, rotating arrangement on the ground plane with an equal inclination angle of 60° to form a symmetrical structure, and the 2.4 and 5 GHz loops are facing each other one by one. The experimental results show that good port isolation can be obtained between antenna ports. High‐gain, directional radiation patterns with wide 3‐dB beamwidth in elevation planes are also observed. Details of a design prototype are described and discussed in the article. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1253–1258, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25208
Trifluoromethylated (tetrahydropyrrolo) quinazolinones by a new three‐component reaction and facile assignment of the regio‐ and stereoisomers formed by NMR spectroscopy
Authors: Dolenský Bohumil , Kvíčala Jaroslav , Paleta Oldřich , Lang Jan , Dvořáková Hana , Čejka Jan 
Published: March 2010

AbstractA new three‐component cyclisation reactions of methyl 3,3,3‐trifluoropyruvate, 2‐aminobenzylamine and oxo compounds afforded tetrahydropyrroloquinazolinones of the types 4 and 5 as mixtures of regio‐ and stereoisomers. Whereas standard 1D NMR spectroscopy was used for a facile assignment of the cyclization regioisomers, a combination of homo (proton–proton) and heteronuclear (proton–fluorine) NOE experiments allowed the determination of the relative configuration on stereogenic centres. The structure of some compounds was also confirmed by the X‐ray diffraction. Adaptation of the 1D double‐pulsed field‐gradient spin‐echo NOE for a heteronuclear case is presented. Copyright © 2010 John Wiley & Sons, Ltd.
Relative acidities and structure analysis of cis and trans isomers of 1,5‐oxazaspiro[5.5] undecane derivatives by multinuclear magnetic resonance
Authors: Guerrero‐Álvarez Jorge Antonio , Mas‐Ku Wendy Paloma , Garcías‐Morales Cesar , Ariza‐Castolo Armando 
Published: March 2010

AbstractThe relative acidities of the cis and trans isomers of a series of 1,5‐oxazaspiro[5.5]undecane derivatives were determined by measuring ΔpK in acid‐base titrations followed by 1 H NMR. Relative structural stabilities were determined by measuring substituent chemical shift and γ‐gauche effects in 13C, 15N, and 17O NMR. Crystallographic characterization of a model spiro[5.5]undecane is presented to support the basicity in solid state. Copyright © 2010 John Wiley & Sons, Ltd.
Synthesis, 1H and 13C NMR assignment and electrochemical properties of novel thiophene–thiazolothiazole oligomers and polymers
Authors: Van Mierloo S. , Chambon S. , Boyukbayram A. E. , Adriaensens P. , Lutsen L. , Cleij T. J. , Vanderzande D. 
Published: March 2010

AbstractNovel hexyl‐substituted bisthiophene compounds containing a thiazolothiazole(5,4‐d) unit have been explored. The molecules are soluble in common organic solvents, which would enhance their chance of possible integration in printable electronics. Synthesis and complete elucidation of the chemical structures by detailed 1D/2D NMR spectroscopy are described. This provides interesting input for chemical shift prediction software, because few experimental data on this type of compounds are available. Furthermore, the potential n‐type character of these derivatives is verified using electrochemical measurements. In addition, the low‐bandgap character of conjugated polymers containing the thiazolothiazole unit is demonstrated by performing an electropolymerization. Copyright © 2010 John Wiley & Sons, Ltd.
Kinetic Modeling of Surface‐Initiated Atom Transfer Radical Polymerization
Authors: Gao Xiang , Feng Wei , Zhu Shiping , Sheardown Heather , Brash John L. 
Published: March 2010

AbstractA kinetic model has been developed using the method of moment for surface‐initiated atom transfer radical polymerization (s‐ATRP) from flat solid surfaces based on a moving boundary physical model. The model is verified with the experimental data of 2‐methacryloyloxyethyl phosphorylcholine from silicon wafer, which were carried out by either adding free initiator (Method I) or excess deactivator (Method II) to the solution. It is shown through the modeling that Method II gives better control over polymer molecular weight and thicker graft layer under similar conditions than Method I. A new mechanism is proposed for the radical termination based on the fact that the rapid activation/deactivation cycle reactions facilitate “migration” of radical centers on the surface. The rate constant of “migration termination” is thus catalyst concentration dependent with higher catalyst concentration resulting in higher termination. Lowering catalyst concentration suppressed migration termination that could improve the control and livingness of s‐ATRP. However, there exists a catalyst concentration for the optimal control performance.magnified image
Teaching medical students about chronic disease: patient‐led teaching in rheumatoid arthritis
Authors: Phillpotts Clare , Creamer Paul , Andrews Tanya 
Published: March 2010

AbstractObjectives: To evaluate the effectiveness of patient‐led teaching compared with doctor‐led teaching, regarding the impact of chronic disease (rheumatoid arthritis [RA]).Methods: A set of learning objectives regarding the impact of RA on patient and family was designed. Students (n = 42) attached to the academy for their musculoskeletal diseases module were randomized to teaching either by a doctor or a patient. Outcome was assessed using a knowledge test, feedback forms and qualitative written interview.Results: In the knowledge test, the groups performed equally. The patient‐taught group scored 24.5 ± 3.5 (max 35); the doctor‐taught group scored 24.6 ± 4.1 (p > 0.05; NS). Feedback was completed by 40/42 students. Mean scores for the overall grading of teaching (1–5, where 1 = worst, 5 = best) were: patient teaching 4.36 (95% confidence interval [CI] 4.11, 4.61); doctor teaching 3.69 (95% CI 3.52, 3.92).The difference between the average scores was 0.42 (p = 0.005). Qualitative feedback showed recurring themes that students appreciated the personal nature of the patient's teaching, enabling them to understand the impact of the disease on patients and their families. The doctors' teaching was also appreciated, particularly the interactive style and opportunity to participate in role play.Conclusions: We have demonstrated that our patient was at least as good as a doctor at teaching about the impact of chronic disease on patients. Furthermore, this experience is valued by students who appreciate the personal insight that a patient can offer. Copyright © 2010 John Wiley & Sons, Ltd.
Homogenization and two‐scale simulations of granular materials for different microstructural constraints
Authors: Miehe C. , Dettmar J. , Zäh D. 
Published: March 2010

AbstractThe paper presents a new method for quasi‐static homogenization of granular microstructures and its embedding into two‐scale simulations. On the coarse scale, a homogenized standard continuum is considered where the granular microstructures are locally attached at each point. These representative volumes are defined by aggregates of discrete solid particles, which may come into contact. On the micromechanical side, the interparticle contact mechanisms between particles is governed by a Coulomb‐type frictional contact. In particular, elliptical‐shaped plane particles are investigated. A consistent extension of classical stiff, soft and periodic boundary conditions from continuous to granular microstructures induce new classes of micro‐to‐macro transitions for granular aggregates. These include constraints not only for particle center displacements but also for particle rotations at a driving boundary frame. The stiff and soft constraints at the driving frame of the particle aggregate induce upper and lower bounds of the particle aggregate's stiffness. On the computational side, we outline a unified implementation of the displacement and rotational constraints by penalty methods that proves to be convenient for straightforward integration into discrete element codes. Representative numerical examples with elliptical‐shaped particles are investigated, where the macroscopic stress responses for different boundary constraints are comparatively discussed. Finally, we embed the granular microstructures into a coarse graining discrete‐to‐finite element model, where they govern the micromechanical behavior of a two‐scale simulation. Copyright © 2010 John Wiley & Sons, Ltd.
Frequent genomic structural alterations at HPV insertion sites in cervical carcinoma
Authors: Peter Martine , Stransky Nicolas , Couturier Jérôme , Hupé Philippe , Barillot Emmanuel , de Cremoux Patricia , Cottu Paul , Radvanyi Francois , Sastre‐Garau Xavier 
Published: March 2010

AbstractTo investigate whether integration of HPV DNA in cervical carcinoma is responsible for structural alterations of the host genome at the insertion site, a series of 34 primary cervical carcinomas and eight cervical cancer‐derived cell lines were analysed. DNA copy number profiles were assessed using the Affymetrix GeneChip Human Mapping 250K Sty array. HPV 16, 18 or 45 integration sites were determined using the DIPS‐PCR technique. The genome status at integration sites was classified as follows: no change, amplification, transition normal/gain, normal/loss or gain/LOH. A single HPV integration site was found in 34 cases; two sites were found in seven cases; and three sites in one case (51 sites). Comparison between integration sites and DNA copy number profiles showed that the genome status was altered at 17/51 (33%) integration sites, corresponding to 16/42 cases (38%). Alterations detected were amplification in nine cases, transition normal/loss in four cases, normal/gain in three cases, and gain/LOH in one case. A highly significant association was found between genomic rearrangement and integration of HPV DNA (p < 10−10). Activation of the replication origin located in viral integrated sequences in a cell line derived from one of the primary cervical carcinomas induced an increase of the amplification level of both viral and cellular DNA sequences flanking the integration locus. This mechanism may be implicated in the triggering of genome amplification at the HPV integration site in cervical carcinoma. Structural alterations of the host genome are frequently observed at the integration site of HPV DNA in cervical cancer and may act in oncogenesis. Copyright © 2010 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Anaplastic plasmacytoma of mouse—establishing parallels between subtypes of mouse and human plasma cell neoplasia
Authors: de Jong Daphne , Janz Siegfried 
Published: March 2010

AbstractMouse models may provide an important tool for basic and applied research on human diseases. An ideal tumour model should replicate the phenotypic and molecular characteristics of human malignancy as well as the typical physiological effects and dissemination patterns. The histopathological and molecular genetic characterization of anaplastic plasmacytoma (APCT) in strain NSF.V+ mice provides an example to achieve this goal for a specific lymphoma subtype. Firstly, it demonstrates that, like plasma‐cell neoplasms in humans, those in mice occur as distinct subtypes. Secondly, it shows that mouse APCT exhibits striking parallels to possible human tumour counterparts for which good mouse models of de novo tumour development are sorely needed: IgM+ multiple myeloma and Waldenström's macroglobulinaemia. Thirdly, it strongly suggests that insertional somatic mutagenesis, by either a murine leukaemia virus or an oncogenic transposon, would be an effective experimental approach to accelerating malignant transformation of mature B cells and plasma cells in mice and, thereby, tagging and uncovering cancer driver genes that may be of great relevance for the tumour initiation and progression in lymphoma. Copyright © 2010 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Issues in multiple imputation of missing data for large general practice clinical databases
Authors: Marston Louise , Carpenter James R. , Walters Kate R. , Morris Richard W. , Nazareth Irwin , Petersen Irene 
Published: March 2010

AbstractPurposeMissing data are a substantial problem in clinical databases. This paper aims to examine patterns of missing data in a primary care database, compare this to nationally representative datasets and explore the use of multiple imputation (MI) for these data.MethodsThe patterns and extent of missing health indicators in a UK primary care database (THIN) were quantified using 488 384 patients aged 16 or over in their first year after registration with a GP from 354 General Practices. MI models were developed and the resulting data compared to that from nationally representative datasets (14 142 participants aged 16 or over from the Health Survey for England 2006 (HSE) and 4 252 men from the British Regional Heart Study (BRHS)).ResultsBetween 22% (smoking) and 38% (height) of health indicator data were missing in newly registered patients, 2004–2006. Distributions of height, weight and blood pressure were comparable to HSE and BRHS, but alcohol and smoking were not. After MI the percentage of smokers and non‐drinkers was higher in THIN than the comparison datasets, while the percentage of ex‐smokers and heavy drinkers was lower. Height, weight and blood pressure remained similar to the comparison datasets.ConclusionsGiven available data, the results are consistent with smoking and alcohol data missing not at random whereas height, weight and blood pressure missing at random. Further research is required on suitable imputation methods for smoking and alcohol in such databases. Copyright © 2010 John Wiley & Sons, Ltd.
Crystallization and spherulitic growth kinetics of poly(trimethylene terephthalate)/polycarbonate blends
Authors: Shafee Ez El , Naguib Halla F. , Li Longfei , Jiang Shichun , An Lijia 
Published: March 2010

AbstractThe macroscopic and microscopic melt‐crystallization kinetics of poly(trimethylene terphthalate) (PTT)/polycarbonate (PC) blends have been measured by differential scanning calorimetry (DSC), and optical microscopy (OM). The results are analyzed in terms of the Avrami equation and the Hoffman–Lauritzen crystallization theory (HL model). Blending with PC did not change the crystallization mechanism of PTT, but reduced the crystallization rate compared with that of neat PTT at the same crystallization temperature. The crystallization rate decreased with increasing crystallization temperature. The spherulitic morphology of PTT was influenced apparently by the crystallization temperature and by the addition of PC. X‐ray diffraction shows no change in the unit cell dimension of PTT was observed after blending. Through the HL theory, the classical regime II→III transition was detected for the neat PTT and the blends. The nucleation parameter (Kg), the fold‐surface free energy (σe), and the work of chain folding (q) were calculated. Blending with PC decreased all the aforementioned parameters compared with those of neat PTT. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers