bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tunable bandstop filter‐based defected ground structure using a metal plate
Authors: Sung Yongje 
Published: November 2008

AbstractTo obtain the electromagnetic bandgap structure with a wide stopband, this article presents a novel approach for realizing a tunable bandstop filter using defected ground structure (DGS) section. To change the rejection band of DGS section, a movable conducting plate is applied in parallel over an H‐shaped defect on the ground plane. The measured results show that the proposed bandstop filter with one cell etched hole has a 30 dB rejection bandwidth of 27.96%, whereas a conventional DGS section of the same dimension has a 30 dB rejection bandwidth of below 1%. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 160–163, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23995
Microwave multi‐level band‐pass filter using discrete‐time Yule‐Walker method
Authors: Hsue Ching‐Wen , Hsu Jer‐Wei , Chen Yen‐Jen , Chen Kuo‐Lung 
Published: November 2008

AbstractThe modified Yule‐Walker scheme is employed to define arbitrary transmission scattering parameter of a multiple‐level band‐pass filter in the discrete‐time domain. Equal‐length microstrips including single‐ and double‐section stubs are used to implement the multiple‐level band‐pass filter. Experimental results are presented to illustrate the validity of this design method. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 225–229, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24006
Human pericardial fluid at microwave frequencies
Authors: Lonappan Anil , Paul Benzy , Thimothy V. O. , Rajasekaran C. , Thomas Vinu , Jacob Joe , Mathew K. T. 
Published: November 2008

AbstractThis article reports a new method of analyzing pericardial fluid based on the measurement of the dielectric properties at microwave frequencies. The microwave measurements were performed by rectangular cavity perturbation method in the S‐band of microwave frequency with the pericardial fluid from healthy persons as well as from patients suffering from pericardial effusion. It is observed that a remarkable change in the dielectric properties of patient samples with the normal healthy samples and these measurements were in good agreement with clinical analysis. This measurement technique and the method of extraction of pericardial fluid are simple. These results give light to an alternative in‐vitro method of diagnosing onset pericardial effusion abnormalities using microwaves without surgical procedure. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 155–158, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24010
A novel control scheme for four‐plate retardation polarization controller
Authors: Liu Yang , Chi Hao , Zhang Xianmin , Jin Xiaofeng , Zheng Shilie 
Published: November 2008

AbstractIn this letter, a control scheme with novel algorithm is proposed and experimentally demonstrated for a four‐plate retardation polarization controller. The presented control scheme consists of two steps. In the first step, a fast localization algorithm (FLA) is applied to transform the input state of polarization (SOP) into a relatively close state to the desired output state; in the second step, an ordinary gradient search algorithm is used to finely tune the wave plates and search for the optimum SOP from the current SOP. The mathematic description on the presented algorithm is presented with the help of Poincaré sphere. Experimental results demonstrate that the efficiency is greatly increased due to the application of the FLA. The performance of the given control scheme is compared with that without the FLA in an experiment with 200 randomly chosen input SOPs. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 124–128, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24011
Impedance matrix generation by using the fast matrix generation technique
Authors: Kwon Soon Jae , Mittra Raj 
Published: November 2008

AbstractThe computation of impedance matrix for layered structures is time‐consuming because each element requires the evaluation of quadruple integrals. To increase the efficiency, we propose a technique referred to as the fast matrix generation. In this method, conventional and rigorous numerical methods are still used for generating the impedance matrix elements that are associated with the near‐field interactions, whereas a more efficient scheme is employed where the separation distance between basis and testing functions exceeds a threshold value. A significant saving in computation time, sometimes over 90%, can be achieved via the application of this approach, as is demonstrated by numerical results for a number of typical microwave circuits. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 204–213, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24015
Control of phase centre location in circular microstrip antennas operating at TM11 and TM02 modes
Authors: Pour Zahra Allahgholi , Shafai Lotfollah 
Published: November 2008

AbstractThe phase centre of a dual‐mode circular microstrip antenna is investigated when the fundamental TM11 and higher order TM02 modes are excited. It is shown that the location of the phase centre can be controlled by the excitation amplitude and phase of these modes. The problem is treated analytically using the cavity model. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 166–169, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24017
Detection of biliary functional problems using microwaves
Authors: Lonappan Anil , Paul Benzy , Thimothy V. O. , Rajasekaran C. , Thomas Vinu , Jacob Joe , Mathew K. T. 
Published: November 2008

AbstractThis article reports a new in vitro bile analysis based on the measurement of the dielectric properties at microwave frequencies. The measurements were made using rectangular cavity perturbation technique at the S‐band of microwave frequency with the different samples of bile obtained from healthy persons as well as from patients. It is observed that an appreciable change in the dielectric properties of patient's samples with the normal healthy samples and these measurements were in good agreement with clinical analysis. These results prove an alternative in‐vitro method of detecting bile abnormalities based on the measurement of the dielectric properties of bile samples using microwaves without surgical procedure. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 101–103, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24021
A compact wideband bandpass filter using single asymmetric SIR with low loss and high selectivity
Authors: Chang Yu‐Chi , Kao Chia‐Hsiung , Weng Min‐Hang 
Published: November 2008

AbstractIn this letter, a novel compact wideband bandpass filter (BPF) using single asymmetric stepped‐impedance resonator with one‐step discontinuity is designed and fabricated. The first two resonant modes of the asymmetric SIR are coupled together and applied to create a wide passband. The proposed filter at center frequency f0 of 4.2 GHz has very good measured characteristics including the bandwidth of 2.9–5.05 GHz (3‐dB fractional bandwidth of 52%), average low insertion loss of 0.2 dB, and sharp rejection of 53 and 88 dB/GHz in lower and higher passband edges. Additionally, the wideband BPF has a smaller circuit size in comparison of previous works. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 242–244, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24023
Methotrexate‐associated alterations of the folate and methyl‐transfer pathway in the CSF of ALL patients with and without symptoms of neurotoxicity
Authors: Vezmar Sandra , Schüsseler Patrick , Becker Achim , Bode Udo , Jaehde Ulrich 
Published: November 2008

AbstractBackgroundSevere neurotoxicity has been observed after systemic high‐dose and intrathecal methotrexate (MTX) treatment. The role of biochemical MTX‐induced alterations of the folate and methyl‐transfer pathway in the development of neurotoxic symptoms is not yet fully elucidated.ProcedureMTX, 5‐methyltetrahydrofolate, calcium folinate, S‐adenosylmethionine, and S‐adenosylhomocysteine were measured in the cerebrospinal fluid (CSF) of 29 patients with acute lymphoblastic leukemia (ALL) who were treated with high‐dose MTX (5 g/m2) followed by calcium folinate rescue (3 × 15 mg/m2) and/or intrathecal (8–12 mg) MTX. Two patients developed subacute MTX‐associated neurotoxicity. CSF was obtained by lumbal puncture 1–3 weeks after administration of MTX and shortly after the occurrence of neurotoxicity. The analytes were measured using HPLC assays with UV and/or fluorescence detection.ResultsIn non‐toxic patients, CSF concentrations of 5‐methyltetrahydrofolate and S‐adenosylmethionine were in the normal range 2 weeks after administration of high‐dose and intrathecal MTX followed by rescue. In contrast, when these patients received intrathecal MTX without rescue, 5‐methyltetrahydrofolate concentrations were significantly decreased 12 days after the first MTX administration. S‐adenosylmethionine concentrations were significantly decreased up to 45 days. The two patients suffering from neurotoxicity had decreased levels of 5‐methyltetrahydrofolate and S‐adenosylmethionine during or following toxicity. S‐adenosylhomocysteine was determined in all samples of neurotoxic patients but was below the limit of quantification in most samples of non‐toxic patients. Calcium folinate was not detected; MTX was present only in samples obtained during its infusion.ConclusionIntrathecal MTX without folinate rescue as well as MTX‐associated neurotoxicity are likely to be associated with specific alterations of the folate and methyl‐transfer pathway. Pediatr Blood Cancer 2009;52:26–32. © 2008 Wiley‐Liss, Inc.
Synthesis and characterization of soluble polyimides functionalized with carbazole moieties
Authors: Mathews Anu Stella , Kim Dongjo , Kim Youngkyoo , Kim Il , Ha Chang‐Sik 
Published: November 2008

AbstractHere, we report the synthesis and characterization of new soluble polyimides that are functionalized using carbazole moieties in their side chain. As a monomer for synthesizing the polyimides, 4″‐carbazole‐9‐yl‐[1,1′;2′,1″] terphenyl‐4‐4′‐diamine and 2‐(3‐carbazol‐9‐yl‐propyl)‐biphenyl‐4,4′‐diamine were synthesized and then characterized using 1H NMR, 13C NMR, FTIR, UV–visible and photoluminescence spectroscopy, differential scanning calorimetry (DSC), and elemental analysis. The polyimides synthesized via chemical imidization processes were characterized with X‐ray photoelectron spectroscopy, gel permeation chromatography, wide angle X‐ray diffraction, thermogravimetric analysis, DSC, tensile strength measurement, and dielectric property measurement. Results showed that the synthesized polyimides were soluble in a variety of organic solvents, optically transparent in a visible range, thermally stable, mechanically strong, and considerably low dielectric. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 8117–8130, 2008
Y‐shaped poly(ethylene glycol) and poly(trimethylene carbonate) amphiphilic copolymer: Synthesis and for drug delivery
Authors: Zhang Huai‐Hong , Huang Zi‐Qun , Sun Bai‐Wang , Guo Jia‐Xiu , Wang Jian‐Li , Chen Yao‐Qiang 
Published: November 2008

AbstractNew Y‐shaped (AB2‐type) amphiphilic copolymers of poly(ethylene glycol) (PEG) with poly(trimethylene carbonate) (PTMC), PEG‐b‐(PTMC)2, were successfully synthesized by the ring‐opening polymerization (ROP) of TMC with bishydroxy‐modified monomethoxy‐PEG (mPEG). First, a bishydroxy functional ROP initiator was synthesized by esterification of acryloyl bromide with mPEG, followed by Michael addition using excess diethanolamine. A series of Y‐shaped amphiphilic PEG‐(PTMC)2 block copolymers were obtained via ROP of TMC using this PEG with bishydroxyl end groups as macroinitiator and ZnEt2 as catalyst. The amphiphilic block copolymers with different compositions were characterized by gel permeation chromatography (GPC) and 1H NMR, and their molecular weight was measured by GPC. The results showed that the molecular weight of Y‐shaped copolymers increased with the increase of the molar ratio of TMC to mPEG‐(OH)2 initiator in feed while the PEG chain length was kept constant. The Y‐shaped copolymer mPEG‐(PTMC)2 could self‐assemble into micelles in aqueous medium and the critical micelle concentration values of the micelles decrease with increase in hydrophobic PTMC block length of mPEG‐(PTMC)2. The in vitro cytotoxicity and controlled drug release properties of the Y‐shaped amphiphilic block copolymers were also investigated. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 8131–8140, 2008
Control of a Pilot‐Scale, Solid‐Liquid Separation Plant Using Electrical Impedance Tomography Measurements
Authors: Gutierrez‐Gnecchi J. A. , Marroquín‐Pineda E. 
Published: November 2008

AbstractThis paper describes the design and construction of a pilot‐scale, solid‐liquid separation plant. The system includes conventional measurements, e.g., inlet feed flow rate and pressure etc., as well as Electrical Impedance Tomography (EIT) measurements to determine the separation status of the separator, by measuring the air core size and position. Image and feature extraction procedures are shown for obtaining the air core measurements. The different aspects in the construction of the plant are described. Tests show that the air core size can be maintained automatically using EIT images over the operating range. The resulting equipment can then be used for testing different implementations of data acquisition systems, EIT image reconstruction procedures and control strategies. The equipment is self‐contained, does not require special facilities and can be used for teaching different aspects of electronics design and control theory to undergraduate students.
Genetic variations in inflammatory mediators influence lung disease progression in cystic fibrosis
Authors: Corvol Harriet , Boelle Pierre‐Yves , Brouard Jacques , Knauer Nicola , Chadelat Katarina , Henrion‐Caude Alexandra , Flamant Cyril , Muselet‐Charlier Celine , Boule Michele , Fauroux Brigitte , Vallet Christelle , Feingold Josue , Ratjen Felix , Grasemann Hartmut , Clement Annick 
Published: November 2008

AbstractThe clinical course of cystic fibrosis (CF) varies considerably among patients carrying the same CF‐causing gene mutation. Additional genetic modifiers may contribute to this variability. As airway inflammation is a key component of CF pathophysiology, we investigated whether major cytokine variants represent such modifiers in young CF patients. We tested 13 polymorphisms in 8 genes that play a key role in the inflammatory response: tumor necrosis factor, lymphotoxin alpha, interleukin (IL) 1B, IL1 receptor antagonist, IL6, IL8, IL10 and transforming growth factor beta 1 (TGFB1), for an association with lung disease progression and nutritional status in 329 CF patients. Variants in the TGFB1 gene at position +869T/C demonstrated a significant association with lung function decline. A less pronounced rate of decline in forced expiratory volume in 1 sec (FEV1) and forced vital capacity (FVC) were observed in patients heterozygous for TGFB1 +869 (+869CT), when compared to patients carrying either TGFB1 +869TT or +869CC genotypes. These findings support the concept that TGFB1 gene variants appear to be important genetic modifiers of lung disease progression in CF. Pediatr. Pulmonol. 2008; 43:1224–1232. © 2008 Wiley‐Liss, Inc.
The EPICure study: Comparison of pediatric spirometry in community and laboratory settings
Authors: Kirkby J. , Welsh L. , Lum S. , Fawke J. , Rowell V. , Thomas S. , Marlow N. , Stocks J. 
Published: November 2008

AbstractRationaleAccuracy of spirometry testing is a prerequisite for its use as an objective outcome measure in large epidemiological studies. We compared spirometry measurements obtained by trained pediatricians in a variety of school settings with those obtained in the laboratory by respiratory physiologists.MethodsFollowing a 3‐day training course, three pediatricians carried out spirometry in children born extremely preterm (EP) and age matched controls in schools across the UK and Ireland (The EPICure study). A subgroup had repeated measurements in the laboratory. Spirometric flows and volumes were expressed as Z‐scores. Bland–Altman analysis was used to calculate within‐subject differences.ResultsFifty children (40% boys), 37 (74%) of whom were born EP, with a mean age 10.8 years had paired spirometry results (average interval between tests: 20.3 weeks). There was no statistically significant difference between any of the outcome variables: mean (95% CI of difference) in Z‐scores [school–laboratory]) being 0.0 (−0.1; 0.1) for FEV1, 0.1 (−0.1; 0.3) for FVC, −0.1 (−0.3; 0.1) for FEF25–75, and 0.0 (−0.3; 0.1) for FEV1/FVC. Within individuals, the 95% limits of agreement for repeated measures were within ± 1 Z‐score for FEV1 and FVC, and within ± 1.5 Z‐score for FEF25–75 and FEV1/FVC.ConclusionWith appropriate training, quality control, and support, pediatric spirometry can reliably be performed outside the lung function laboratory. Pediatr. Pulmonol. 2008; 43:1233–1241. © 2008 Wiley‐Liss, Inc.
Detailed balance and reciprocity in solar cells
Authors: Kirchartz Thomas , Rau Uwe 
Published: November 2008

AbstractThe limiting efficiency of photovoltaic devices follows from the detailed balance of absorption and emission of a diode according to the Shockley–Queisser theory. However, the principle of detailed balance has more implications for the understanding of photovoltaic devices than only defining the efficiency limit. We show how reciprocity relations between carrier collection and dark carrier injection, between electroluminescence emission and photovoltaic quantum efficiency and between open circuit voltage and light emitting diode quantum efficiency all follow from the principle of detailed balance. We also discuss the validity range of the Shockley–Queisser limit and the reciprocity relations. Discussing the validity of the reciprocity relations helps to deepen the understanding of photovoltaic devices and allows us to identify interrelationships between the superposition principle, the diode ideality and the reciprocity relations. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A rapid and precise method for determination of D/H ratios of plant methoxyl groups
Authors: Greule Markus , Mosandl Armin , Hamilton John T. G. , Keppler Frank 
Published: November 2008

AbstractStable hydrogen isotope ratio measurements of specific plant components are increasingly used in numerous fields of research, including sample origin verification and climate research. A recently suggested method with considerable potential in this context is the D/H isotope ratio (δ2H value) analysis of plant matter methoxyl groups. The method entails ether or ester cleavage with hydriodic acid (HI) to form the gaseous compound methyl iodide (CH3I) and measurement of the δ2H value of this gas. Here we describe a method for the rapid and precise δ2H analysis of plant matter methoxyl groups using gas chromatography/pyrolysis/isotope ratio mass spectrometry (GC/P/IRMS). The conditions for sample preparation were investigated for isotope discrimination effects, the GC conditions were optimized, the reproducibility of the measurement of standards was studied, and the precision of the method was defined. The reproducibility of δ2H values determined for a CH3I standard on 20 consecutive measurements was found to be 2‰. The method was also tested on four methoxyl‐rich plant components: vanillin, lignin, wood and pectin. The analytical precision obtained, when expressed as the average standard deviation for these compounds, was better than 1.6‰. The described method is rapid, allowing preparation and analysis of a sample within 1 h, and produces accurate and reproducible isotopic measurements. Copyright © 2008 John Wiley & Sons, Ltd.
Stability conditions for integral delay systems
Authors: Melchor‐Aguilar Daniel , Kharitonov Vladimir , Lozano Rogelio 
Published: November 2008

AbstractIn this paper we consider a special class of integral delay systems arising in several stability problems of time‐delay systems. For these integral systems we derive stability and robust stability conditions in terms of Lyapunov–Krasovskii functionals. More explicitly, after providing the stability conditions we compute quadratic functionals and apply them to derive exponential estimates for solutions, and robust stability conditions for perturbed integral delay systems. Copyright © 2008 John Wiley & Sons, Ltd.
Modeling email use: a case of email system transition
Authors: Kanungo Shivraj , Jain Vikas 
Published: November 2008

AbstractA large urban university expected its transition to a new and improved email system to result in higher productivity than before. However, email productivity did not show significant improvement after the transition. To understand this lack of improvement in productivity, we modeled the relations among variables that affect email use and productivity using system dynamics. The results show that in non‐volitional use situations stress related to email use and email productivity are significantly influenced by the levels of tolerable email backlog and steady incoming emails. Users react to changes in email backlog by calibrating their level of use. This adjustment, in turn, depends on each user's level of email self‐efficacy and the rate at which users learn to adapt to changes. The contribution of this paper lies in showing that email productivity can improve if users develop a stable pattern of email use. This can minimize variations in email use and in so doing is likely to leverage email use. Copyright © 2008 John Wiley & Sons, Ltd.
Nutritive value of different varieties and morphological fractions of oats harvested at the soft dough stage
Authors: Feyissa Fekede , Tolera Adugna , Melaku Solomon 
Published: November 2008

AbstractChemical composition and in vitro organic matter digestibility (IVOMD) were measured in whole forage and morphological fractions of 20 varieties of oats (Avena sativa) harvested at the soft dough stage. Among the varieties, crude protein (CP) varied from 48 to 76 g kg−1 dry matter (DM), neutral detergent fibre (NDF) from 586 to 683 g kg−1 DM, acid detergent fibre (ADF) from 370 to 482 g kg−1 DM and lignin from 54 to 83 g kg−1 DM. The IVOMD of the whole forage ranged from 43 to 62%. Among the morphological fractions, leaf blades had the highest CP content and IVOMD, whereas the fibre constituents (NDF, ADF and lignin) were highest in the stems. The results revealed considerable variation in chemical composition and IVOMD among the oat varieties and morphological fractions. This implies that there are opportunities for improving forage production and quality from oats through appropriate exploitation of varietal differences. However, manipulation of management practices (such as choice of harvesting stage, use of mixed cropping with compatible legumes and fertiliser application) may still be needed for further improvement. Copyright © 2008 John Wiley & Sons, Ltd