bluuebunny/crossref_metadata_2025 huggingface dataset:
Synergistic genotoxicity caused by low concentration of titanium dioxide nanoparticles andp,p′‐DDT in human hepatocytes
Authors: Shi Yun , Zhang Jiang‐Hua , Jiang Ming , Zhu Li‐Hua , Tan He‐Qing , Lu Bin
Published: August 2009

The use of titanium dioxide nanoparticles (nano‐TiO2) for the degradation of dichlorodiphenyltrichloroethane (p,p′‐DDT) increases the risk of exposure to trace nano‐TiO2andp,p′‐DDT mixtures. The interaction ofp,p′‐DDT and nano‐TiO2at low concentrations may alter toxic response relative to nano‐TiO2orp,p′‐DDT alone. In this work, the combined genotoxicity of trace nano‐TiO2andp,p′‐DDT on human embryo L‐02 hepatocytes without photoactivation was studied. Nano‐TiO2(0.1 g/L) was mixed with 0.01–1 mmol/Lp,p′‐DDT to determine adsorption isotherms. L‐02 cells were exposed to different levels ofp,p′‐DDT (0, 0.001, 0.01, and 0.1 μmol/L) and nano‐TiO2(0, 0.01, 0.1, and 1 μg/mL) respectively. The adsorption ofp,p′‐DDT by nano‐TiO2was approximately 0.3 mmol/g. Cell viability, apoptosis, and DNA double strand breaks were similar among all test groups. Nano‐TiO2alone (0.01–1 μg/mL) increased the levels of oxidative stress and oxidative DNA adducts (8‐OHdG), but it did not induce DNA breaks or chromosome damage. Addition of trace nano‐TiO2with tracep,p′‐DDT synergistically enhanced genotoxicity via increasing oxidative stress, oxidative DNA adducts, DNA breaks, and chromosome damage in L‐02 cells. Low concentrations of nano‐TiO2andp,p′‐DDT increased oxidativestress by reactive oxygen species (ROS) formation and lipid oxidation. Oxidative stress is a major pathway for DNA and chromosome damage. Dose‐dependent synergistic genotoxicity induced by combined exposure of tracep,p′‐DDT and nano‐TiO2suggests a potential environmental risk of nano‐TiO2assisted photocatalysis. Environ. Mol. Mutagen., 2010. © 2009 Wiley‐Liss, Inc.
Wind generation curtailment to relieve line overload in an on‐line environment
Authors: Acharya Naresh , Liu Chen‐Ching , Djukanovic Miodrag B.
Published: August 2009

In areas with high wind power penetration, the protection of transmission lines from overload during critical contingencies is an important issue. The objective of this research is to formulate the technical problem and develop a methodology to solve the problem associated with overloading of transmission facilities in high wind generation areas. The proposed method is to curtail the wind turbine outputs through the Energy Management System facilities in the on‐line operational environment. The proposed method, which is based on linear optimization, sends the calculated control signals via the Supervisory Control and Data Acquisition (SCADA) system to wind farm controllers. The necessary ramping of the wind farm outputs is implemented by the appropriate blade pitch angle control at the turbine level. The curtailment strategy is tested with an equivalent system model of MidAmerican Energy Company (MEC). The results show that the line overload in high wind generation areas can be alleviated by controlling the outputs of the wind farms step‐by‐step over an allowable period of time. Copyright © 2008 John Wiley & Sons, Ltd.
FEM analysis of electromagnetic transients in linear networks
Authors: Lucic Rino , Juric‐Grgic Ivica , Jovic Vinko
Published: August 2009

This paper describes a new general solution method when modeling electromagnetic transients in single networks with linear lossy transmission lines in the time domain using the finite element method. Based on FEM and the generalized trapezoidal rule a novel numerical procedure for the system of the telegraph equations is presented. The presented technique enables to make a simple algorithm for the analysis of electrical network with linear lossy transmission lines. The proposed method for electrical network transient's analysis including lossy transmission lines in time domain has been successfully tested and compared to the analytical solution. Copyright © 2008 John Wiley & Sons, Ltd.
Optimal selection of artificial neural network parameters for the prediction of a karstic aquifer's response
Authors: Trichakis Ioannis C. , Nikolos Ioannis K. , Karatzas George P.
Published: August 2009

The simulation of karstic aquifers is difficult using traditional groundwater numerical simulators, as the exact knowledge of the hydraulic characteristics of the physical system in small scale is rarely available and the numerical simulators produce results of limited reliability. In the present work, artificial neural networks (ANNs) are utilized to predict the response of a karstic aquifer, using the hydraulic head change per time step rather than the hydraulic head itself as output parameter of the network. As it will be demonstrated, in the first case a better approximation of the physical system's response is achieved as the change of the hydraulic head is more naturally connected to the input parameters of the network, which model the aquatic equilibrium of the system. The correlation of rainfall and hydraulic head change per time step was initially used to determine the time lag of the rainfall input data, which represents the time needed by the rainfall to percolate and reach the water table. In a second step, a differential evolution (DE) algorithm is utilized for the optimal selection of rainfall time lag as well as ANN's architecture and training parameters. Although a time consuming procedure, the improvement obtained suggests that the empirical determination of the ANN parameters and structure is not always sufficient and an optimization procedure, which minimizes the training and evaluation errors of the ANN, may provide substantially better simulation results. The optimized networks were finally used for midterm predictions (30 to 90 days ahead) of the hydraulic head, showing the ability of the ANN with hydraulic head change as output parameter to provide predictions with high accuracy at the end of the considered time period. Copyright © 2009 John Wiley & Sons, Ltd.
Precipitation variability and its relationship to hydrologic variability in Alberta
Authors: Mwale Davison , Gan Thian Yew , Devito Kevin , Mendoza Carl , Silins Uldis , Petrone Richard
Published: August 2009

By applying wavelet‐based empirical orthogonal function (WEOF) analysis to gridded precipitation (P) and empirical orthogonal function (EOF) analysis to gridded air temperature (T), potential evapotranspiration (PET), net precipitation (P‐PET) and runoff (Q), this paper examines the spatial, temporal and frequency patterns of Alberta's climate variability. It was found that only WEOF‐based precipitation patterns, possibly modulated by El Nino Southern Oscillation (ENSO) and Pacific Decadal Oscillation(PDO), delineated Alberta into four major regions which geographically represent northern Alberta Boreal forests, southern Alberta grasslands and Aspen Parklands and the Rocky Mountains and Foothills. The leading mode of wavelet‐based precipitation variability WPC1 showed that between 1900 and 2000, a wet climate dominated northern Alberta with significant 4–8, 11 and 25‐year periodic cycles, while the second mode WPC2 showed that between 1960 and 2000, southern Alberta grasslands were characterized by decreasing precipitation, dominated by 11‐year cycles, and the last two modes WPC3 and WPC4 were characterized by 4–7 and 25‐year cycles and both delineated regions where moisture from the Pacific Ocean penetrated the Rocky Mountains, accounted for much of the sub‐alpine climate. These results show that WEOF is superior to EOF in delineating Alberta precipitation variability to sub‐regions that more closely agree with its eco‐climate regions. Further, it was found that while WPC2 could not explain runoff variations in southern Alberta, WPC1, WPC3 and WPC4 accounted for runoff variability in their respective sub‐regions. Copyright © 2009 John Wiley & Sons, Ltd.
Bayesian analysis of stage–fall–discharge models for gauging stations affected by variable backwater
Authors: Petersen‐Øverleir Asgeir , Reitan Trond
Published: August 2009

Parsimonious stage–fall–discharge rating curve models for gauging stations subject to backwater complications are developed from simple hydraulic theory. The rating curve models are compounded in order to allow for possible shifts in the hydraulics when variable backwater becomes effective. The models provide a prior scientific understanding through the relationship between the rating curve parameters and the hydraulic properties of the channel section under study. This characteristic enables prior distributions for the rating curve parameters to be easily elicited according to site‐specific information and the magnitude of well‐known hydraulic quantities. Posterior results from three Norwegian and one American twin‐gauge stations affected by variable backwater are obtained using Markov chain Monte Carlo simulation techniques. The case studies demonstrate that the proposed Bayesian rating curve assessment is appropriate for developing rating procedures for gauging stations that are subject to variable backwater. Copyright © 2009 John Wiley & Sons, Ltd.
Architecture of the nervous system in mystacocarida (Arthropoda, crustacea)—An immunohistochemical study and 3D reconstruction
Authors: Brenneis Georg , Richter Stefan
Published: August 2009

Mystacocarida is a species‐poor group of minute crustaceans with unclear phylogenetic affinities. Previous studies have highlighted the putative “primitiveness” of several mystacocarid features, including the architecture of the nervous system. Recent studies on arthropod neuroarchitecture have provided a wealth of characters valuable for phylogenetic reconstructions. To permit and facilitate comparison with these data, we used immunohistochemical labeling (against acetylated α‐tubulin, serotonin and FMRFamide) on the mystacocarid Derocheilocaris remanei, analyzing it with confocal laser‐scanning microscopy and 3D reconstruction. The mystacocarid brain is fairly elongated, exhibiting a complicated stereotypic arrangement of neurite bundles. However, none of the applied markers provided evidence of structured neuropils such as a central body or olfactory glomeruli. A completely fused subesophageal ganglion is not present, all segmental soma clusters of the respective neuromeres still being delimitable. The distinct mandibular commissure comprises neurite bundles from more anterior regions, leading us to propose that it may have fused with an ancestral posterior tritocerebral commissure. The postcephalic ventral nervous system displays a typical ladder‐like structure with separated ganglia which bears some resemblance to larval stages in other crustaceans. Ganglia and commissures are also present in the first three limbless “abdominal” segments, which casts doubt on the notion of a clear‐cut distinction between thorax and abdomen. An unpaired longitudinal median neurite bundle is present and discussed as a potential tetraconate autapomorphy. Additionally, a paired latero‐longitudinal neurite bundle extends along the trunk. It is connected to the intersegmental nerves and most likely fulfils neurohemal functions. We report the complete absence of serotonin‐ir neurons in the ventral nervous system, which is a unique condition in arthropods and herein interpreted as a derived character. J. Morphol., 2010. © 2009 Wiley‐Liss, Inc.
The median‐fin skeleton of the Eastern Atlantic and Mediterranean clingfishes Lepadogaster lepadogaster (Bonnaterre) and Gouania wildenowi (Risso) (Teleostei: Gobiesocidae)
Authors: Konstantinidis Peter , Conway Kevin W.
Published: August 2009

Previous research on the osteology of the Gobiesocidae focused mostly on the neurocranium and the thoracic sucking disc (formed by the paired‐fin girdles). Little attention has been paid to the skeleton of the median fins. The dorsal‐ and anal‐fin skeleton of Lepadogaster lepadogaster and other gobiesocids (excluding Alabes, which lacks these fins) are characterized by the absence of spines, branched fin‐rays, and middle radials. In gobiesocids, the distal radials never ossify and consist of elastic hyaline‐cell cartilage. Gouania wildenowi is unique among gobiesocids in having further reductions of the dorsal‐ and anal‐fin skeleton, including a notable decrease in the size of the proximal‐middle radials in an anterior–posterior direction. Unlike L. lepadogaster, which exhibits a one‐to‐one relationship between the dorsal‐ and anal‐fin rays and proximal‐middle radials, G. wildenowi has a higher number of proximal‐middle radials than distal radial cartilages and fin rays in the dorsal and anal fins. In G. wildenowi, the dorsal‐ and anal‐fin rays do not articulate with the distal tip of the proximal‐middle radials but are instead positioned between proximal‐middle radials, which is unusual for teleosts. Previously unrecognized dorsal and ventral pads of elastic hyaline‐cell cartilage are also present in the caudal skeleton of L. lepadogaster, G. wildenowi, and all other gobiesocids examined. J. Morphol., 2010. © 2009 Wiley‐Liss, Inc.
Surface‐enhanced Raman micro‐spectroscopy of DNA/RNA bases adsorbed on pyroxene rocks as a test ofin situsearch for life traces on Mars
Authors: Muniz‐Miranda Maurizio , Gellini Cristina , Salvi Pier Remigio , Pagliai Marco
Published: August 2009

SERS spectroscopy with 785‐nm laser excitation minimizing fluorescence emission is exploited for remote analysis of life traces in an extraterrestrial environment. Adenine and guanine, nucleobases present in both DNA and RNA strands, and microRNA containing adenine and guanine have been used as testing ligands for identifying traces of nucleic acids in Martian rocks and sediments. SERS spectra of these nucleobase samples adsorbed on pyroxene substrates have been investigated with micro‐Raman apparatus in the absence of sample manipulation and inducing the signal enhancement by deposition of silver colloidal nanoparticles over the pyroxene/nucleobase substrates. An order‐of‐magnitude estimate of the sample amount responsible for the SERS spectra is given. Copyright © 2009 John Wiley & Sons, Ltd.
A predictive model of minimally invasive bipolar fractional radiofrequency skin treatment
Authors: Berube Dany , Renton Bradley , Hantash Basil M.
Published: August 2009

Background

A novel bipolar fractional radiofrequency (FRF) system with temperature feedback was recently developed for facial laxity and rhytid treatment. The study objective was to develop a model based on published in vivo human skin data that could be extrapolated to aid physicians in making future dosimetry choices under clinically relevant conditions.

Methods

A standard electrode pair designed for use with the FRF system was modeled using finite element analysis (FEA). The model incorporated temperature feedback from sensors within the electrodes, selectable target dermal temperatures, and an epidermal cooling plate. The model was validated using data obtained during clinical treatments. Thermal injury as a function of target temperatures and electrical conductivity was simulated and then validated using in vivo histology results.

Results

Lesion size predicted by the model matched histology samples. Lesion width and height were 1.65 and 1.24 mm compared to 1.75 and 1.21 mm for the model versus in vivo, respectively. The thermal profile remained confined between the proximal and distal ends of the electrodes. Ninety‐six percent of power was deposited in the dermis. Dose–response curves showed a nonlinear volume increase to 1.7 and 4.7 mm3 at target temperatures of 65 and 75°C, respectively, and a low sensitivity to electrical conductivity variation.

Conclusion

FEA of the Bipolar FRF system revealed that isotherms were mainly within the dermis. Lesion volume was found to be less sensitive to changes in electrical conductivity than to target temperature and duration. Simulation results matched well the in vivo lesion dimensions. To our knowledge, this is the first model of bipolar FRF treatment capable of accurately predicting the thermal response of human skin in vivo. The findings of this study allow for the development of accurate dose–response curves to aid physicians in parameter selection and achieving efficacy and safety profiles. Lasers Surg. Med. 41:473–478, 2009. © 2009 Wiley‐Liss, Inc.
In vitro large diameter bowel anastomosis using a temperature controlled laser tissue soldering system and albumin stent
Authors: Spector David , Rabi Yaron , Vasserman Irena , Hardy Amos , Klausner Joseph , Rabau Micha , Katzir Abraham
Published: August 2009

Background and Objective

In today's age of advancing surgical technology, there is a need for better and simpler methods of tissue bonding. The use of lasers for tissue welding or soldering is one of these sutureless methods. In 30 years of laser tissue bonding (LTB) research, published reports of cylindrical organ anastomosis were limited to small diameters. The tension resisted by the anastomosis, which is caused by the intraluminal pressure, is also proportional to the organ diameter. Therefore the anastomosis of large diameter organs requires significantly stronger mechanical strength. The aim of this study is to demonstrate such an anastomosis.

Materials and Methods

In vitro anastomosis of porcine small bowel was performed by either LTB or sutures. Anastomosis in the laser group (number of samples, n = 15) included two main stages of soldering. The bowel edges were approximated over a solid albumin stent and heated with a temperature controlled GaAs laser system to 75°C. This was followed by spreading liquid albumin on the anastomotic line and heating by the same system again to 75°C. The control group (n = 5) was sutured anastomosis. All anastomoses were assessed by burst pressure measurement.

Results

The burst pressure of the laser group attained 170±40 mmHg which was significantly higher than that of the sutured group 83±37 mmHg (P < 0.001).

Conclusion

This report describes the in vitro LTB anastomosis of a large diameter cylindrical organ. The immediate bond strength, as estimated by burst pressure measurements, was double compared to sutured anastomosis. Lasers Surg. Med. 41:504–508, 2009. © 2009 Wiley‐Liss, Inc.
Ex vivo and in vivo evaluation of laser‐induced thermotherapy for nodular thyroid disease
Authors: Ritz Jörg‐P. , Lehmann Kai S. , Zurbuchen Urte , Knappe Verena , Schumann Thomas , Buhr Heinz J. , Holmer Christoph
Published: August 2009

Background and Objective

The prevalence of thyroid nodules ranges between 2% and 60% depending on the population studied. However, minimally invasive procedures like laser‐induced thermotherapy (LITT) are increasingly used to treat tumors of parenchymatous organs and seem to be suitable for singular thyroid nodules as well. Their successful clinical application depends on the induction of sufficiently large lesions and a knowledge of the energy parameters required for complete thermal ablation. The aim of this study was to establish a dose–response relationship for LITT of thyroid nodules.

Materials and Methods

Thermal lesions were induced in healthy porcine thyroid glands ex vivo (n = 110) and in vivo (n = 10) using an Nd:YAG laser (1,064 nm). Laser energy was applied for 300 seconds in a power range of 10–20 W. During the ablation, continuous temperature measurement at a distance of 5 and 10 mm from the applicator was performed. The lesions were longitudinally and transversally measured, and the volume was calculated. Furthermore, enzyme histochemical analysis of the thyroid tissue was performed.

Results

The maximum inducible lesion volumes were between 0.74 ± 0.18 cm3 at a laser power of 10 W and 3.80 ± 0.41 cm3 at 20 W. The maximum temperatures after ablation were between 72.9 ± 2.9°C (10 W) and 112.9 ± 9.2°C (20 W) at a distance of 5 mm and between 49.5 ± 2.2°C (10 W) and 73.2 ± 6.7°C (20 W) at a distance of 10 mm from the applicator. The histochemical analysis demonstrates a complete loss of NADPH dehydrogenase activity in thermal lesions as a sign of irreversible cell damage.

Conclusions

This study is the first to demonstrate a dose–response relationship for LITT of thyroid tissue. LITT is suitable for singular thyroid nodules and induces reproducible clinically relevant lesions with irreversible cell damage in an appropriate application time. Lasers Surg. Med. 41:479–486, 2009. © 2009 Wiley‐Liss, Inc.
Electrospinning of Novel Poly(ester amide)s
Authors: Garg Priya , Klee Doris , Keul Helmut , Möller Martin
Published: August 2009

Novel PEAs derived from 1,4‐butanediol, dimethyl adipate and a preformed α,ω‐amino alcohol were synthesised and successfully electrospun from solution. The effects of increasing the ratio of amide/ester groups in the copolymer, polymer concentration, solvent mixtures and applied voltage on fibre morphology and diameter were investigated. The obtained fibres (diameter 180–450 nm) were randomly oriented. The fibre quality and homogeneity increased with increasing amide concentration. The solvent mixture CHCl3/HCOOH gave the best electrospinning results. The ultra‐fine fibres were characterised using SEM, DSC and FT‐IR, showing that the electrospun fibres are amorphous as compared to the pristine samples. These fibres are potential candidates for use as scaffolds in tissue engineering.

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A new method for scoring additive multi‐attribute value models using pairwise rankings of alternatives
Authors: Hansen Paul , Ombler Franz
Published: August 2009

We present a new method for determining the point values for additive multi‐attribute value models with performance categories. The method, which we refer to as PAPRIKA (Potentially All Pairwise RanKings of all possible Alternatives), involves the decision‐maker pairwise ranking potentially all undominated pairs of all possible alternatives represented by the value model. The number of pairs to be explicitly ranked is minimized by the method identifying all pairs implicitly ranked as corollaries of the explicitly ranked pairs. We report on simulations of the method's use and show that if the decision‐maker explicitly ranks pairs defined on just two criteria at‐a‐time, the overall ranking of alternatives produced by the value model is very highly correlated with the true ranking. Therefore, for most practical purposes decision‐makers are unlikely to need to rank pairs defined on more than two criteria, thereby reducing the elicitation burden. We also describe a successful real‐world application involving the scoring of a value model for prioritizing patients for cardiac surgery in New Zealand. We conclude that although the new method entails more judgments than traditional scoring methods, the type of judgment (pairwise rankings of undominated pairs) is arguably simpler and might reasonably be expected to reflect the preferences of decision‐makers more accurately. Copyright © 2009 John Wiley & Sons, Ltd.
Polarimetric multilongitudinal‐mode distributed Bragg reflector fiber laser sensor for strain measurement
Authors: Zhang Hao , Luo Jianhua , Liu Bo , Wang Shuangxia , Jia Chenglai , Ma Xiurong
Published: August 2009

A polarimetric multilongitudinal‐mode distributed Bragg reflector fiber laser sensor is proposed and experimentally demonstrated. We have theoretically analyzed the mode beat mechanism of this laser sensor, which is verified by the experimental observation, and its application in strain measurement has also been studied. Experimental results indicate that both of the longitudinal mode beat (LMB) and birefringence‐induced polarization mode beat signals have linear strain dependence, and the coefficients of determination reach 0.9991 and 0.9908, respectively. One possible way to improve the sensitivity of LMB‐based sensing has been investigated as well. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2559–2563, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24671
Wideband impedance‐transforming three‐port power divider using lumped elements
Authors: Cho Seung‐Hyun , Park Chan Hyeong , Chung In‐Young , Jeong Jinho
Published: August 2009

In this article, we propose a new wideband impedance‐transforming three‐port power divider using lumped elements. Instead of a π‐network used in the conventional lumped Wilkinson power divider, an L‐type matching network is employed in the new design, which keeps quality(Q)‐factors low during impedance transformation, allowing wideband performance. The simulation proves that the proposed power divider achieves wider bandwidth than the conventional one in the performance of return loss, isolation and insertion loss. A 2 GHz power divider which transforms the impedance from 25 to 50 Ω was designed using the derived equations. The measurement showed the insertion loss of −3.3 dB, return loss of −27.1 dB and isolation of −24.7 dB at 1.9 GHz with broadband performance. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2570–2573, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24675
Integrated CMOS impulse UWB receiver front‐end design
Authors: Miao Meng , Nguyen Cam
Published: August 2009

A single‐chip broadband CMOS receiver front‐end, integrating a low‐noise amplifier (LNA), a correlator, and a template pulse generator, was investigated in nonsinusoidal time‐domain environment for possible use as an impulse‐type ultra‐wideband (UWB) receiver front‐end. Particularly, the CMOS LNA and the multiplier making up the core component of the correlator were designed, fabricated, and tested to verify operation in the UWB range. Time‐domain results of the integrated CMOS receiver front‐end demonstrate its workability as a receiver for nonsinusoidal UWB applications. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2590–2595, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24682
A compact wideband PIFA
Authors: Chung K. L. , Tam W. Y. , Kan H. K.
Published: August 2009

In this article we present a modified planar inverted‐F antenna that is compact and has a wide impedance bandwidth. The antenna incorporates a T‐shaped slot on the antenna and a folded patch to increase the path length of the antenna and hence improve its bandwidth. The 10‐dB return loss bandwidth of the antenna is 81.3% and exhibits quasi omni‐directional far‐field patterns. The overall dimension of the compact antenna is 34 mm × 8.0 mm × 8.0 mm. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2554–2556, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24684
UWB bandpass filters using short‐circuited shunt stub‐embedded multiple‐mode resonators
Authors: Wong Sai Wai , Zhu Lei
Published: August 2009

An ultra‐wideband (UWB) bandpass filter with good out‐of‐band rejection is presented in this work. As a starting part of designing UWB filter, a shunt short‐circuited stub is introduced at the center of a half‐wavelength resonator and it can generate two transmission zeros near the lower and upper cutoff frequencies. With the use of even‐ and odd‐mode approach, this initial multiple‐mode resonator is characterized and designed to build up a bandpass filter with good UWB passband and highly attenuated out‐of‐band skirt. Next, a coupled‐line section with cross‐coupling property is formed in this short‐circuited stub so as to widen the concerned upper‐stopband due to excitation of two more transmission zeros. Finally, a UWB bandpass filter prototype is fabricated to experimentally validate the attractive in‐band and out‐of‐band performances as predicted in theory. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2556–2559, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24687
Signal reshaping in a transmission line with negative group velocity behavior
Authors: Monti Giuseppina , Tarricone Luciano
Published: August 2009

An analytical, numerical, and experimental study of the dispersion of a transmission line with negative group velocity is presented. The propagation of amplitude‐modulated signals in the transmission line anomalous dispersion region is specifically analyzed, investigating the effects on the pulse reshaping of the system losses. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2627–2633, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24688
A micromachined SiGe HBT ultra‐wideband low‐noise amplifier by BiCMOS compatible ICP deep‐trench technology
Authors: Huang Pen‐Li , Lin Yu‐Tso , Wang Tao , Lin Yo‐Sheng , Lu Shey‐Shi
Published: August 2009

In this article, we demonstrate that the power gain (S21) and noise figure (NF) performances of a SiGe HBT Ultra‐Wideband Low‐Noise Amplifier (UWB LNA) can be remarkably improved by removing the silicon underneath the UWB LNA with BiCMOS‐process compatible backside inductively‐coupled‐plasma (ICP) deep trench technology. The results show that increases of 1.9 dB (from 11.2 dB to 13.1 dB) and 4.2 dB (from 7.7 dB to 11.9 dB) in S21, and decreases of 0.59 dB (from 5.08 dB to 4.49 dB) and 0.74 dB (from 6.2 dB to 5.46 dB) in NF were achieved at 10 GHz and 13 GHz, respectively, for the SiGe HBT UWB LNA after the backside ICP dry etching. The excellent performances of the SiGe HBT UWB LNA with suspended inductors suggest that it is very suitable for UWB system applications. Besides, the BiCMOS‐process compatible backside ICP etching technique is very promising for BiCMOS integrated circuit (IC) applications. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2598–2601, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24691
The RF characteristics of micromachined coplanar waveguide in 0.13 μm CMOS technology by CMOS compatible ICP dry etching
Authors: Wang Tao , Lu Shey‐Shi , Lin Yo‐Sheng , Juang Yin‐Zong , Huang Guo‐Wei
Published: August 2009

A coplanar waveguide (CPW) was implemented in 0.13 μm CMOS technology and then postprocessed by CMOS compatible inductively‐coupled plasma etching, which removed the silicon underneath the coplanar strips. Transmission line parameters such as characteristic impedance ZO, attenuation constant α, substrate capacitance/conductance C/G, series inductance/resistance L/R, as a function of frequency were extracted. It is found that α, C, and G can be greatly improved after silicon removal. Specifically, a 0.45 dB/mm reduction (from 0.5 to 0.05 dB/mm) in α, a 1.6 mS/mm reduction (from 1.6 to ∼0 mS/mm) in G, and a 43.9% reduction (from 92.8 to 52.1 fF/mm) in C were achieved at 20 GHz. In addition, this work also investigates the dielectric loss αdand conductive loss αcof the CPW. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2665–2668, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24693
Very‐low‐profile monopole antennas for concurrent 2.4‐ and 5‐GHz WLAN access‐point applications
Authors: Su Saou‐Wen
Published: August 2009

In this article, a very‐low‐profile, six‐antenna multiple‐input multiple‐output (MIMO) system aimed at operating in the concurrent 2.4 and 5 GHz bands for WLAN access‐point applications is proposed. The MIMO system mainly consists of an antenna ground plane and six short‐circuited monopole 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, and the 2.4 and 5 GHz antennas are facing each other one by one. The results show that well port isolation can be obtained together with good radiation characteristics. With a low profile of 6 mm in height, the proposed design can easily fit into wireless access points or routers and allow the 2.4‐ and 5‐GHz band signals to be simultaneously received and transmitted with no need of external diplexer. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2614–2617, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24700
Fractal Koch dipole antenna for UHF band application
Authors: Karim Mohd Nazri A. , Rahim Mohamad Kamal A. , Masri Thelaha
Published: August 2009

The fractal Koch curve is one of the popular fractals shape. This article discussed the analysis of the fractal Koch dipole antenna (FKDA) using log periodic technique. The effect of flare angle of the antenna has been described to reduce the antenna size. The antenna is operated at ultrahigh frequency (UHF) band frequency between 460 MHz and 4 GHz. The analysis is based on the number of elements, degree of flare angle, current distribution, and radiation pattern of the antennas. The antenna has been designed and simulated using computer simulation technology (CST) and fabricated using FR4 board. The performance of the antennas has been measured, analyzed, and discussed in this article. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2612–2614, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24702
A dual‐band split‐ring monopole antenna for WLAN applications
Authors: Cumhur Basaran Siddik , E. Erdemli Yunus
Published: August 2009

In this article, a novel dual‐band microstrip monopole antenna based on split‐ring elements is proposed for WLAN (2.4/5 GHz) applications. The antenna fed by a two‐stage microstrip line has fairly small dimensions and provides 7.5 and 25.5% impedance bandwidth performance at the respective bands. Also, the antenna exhibits almost uniform radiation patterns at each frequency band. The measurement results of the fabricated antenna are in good agreement with the simulations. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2685–2688, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24708
Design of a band‐stop UWB antenna with two L‐shaped stubs
Authors: Shin Jaekon , Hong Seokjin , Choi Jaehoon
Published: August 2009

In this article, a novel ultra‐wideband (UWB) antenna with band‐stop characteristic is proposed. The UWB characteristic of the proposed antenna is achieved by adopting two spiral elements. By attaching two L‐shaped stubs along the microstrip feed line, the band‐stop performance can be achieved. The designed antenna has a small size and operates across the frequency range from 3.17 to over 11 GHz to meet a 10‐dB return loss requirement while providing band‐stop performance in the frequency band from 5.14 to 5.96 GHz. Measured results reveal that the proposed antenna has good radiation performance and is suitable for UWB applications. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2656–2660, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24710
Coupling‐fed circular‐patch antenna for on‐body communication system
Authors: Ma Da , Zhang Wenxun X.
Published: August 2009

A new scheme of antenna for wireless body area networks is proposed. A coupling‐fed circular‐patch antenna with TM01 mode is designed, simulated, and tested, which radiates omni‐directional pattern along the body surface and has linear polarization normal to the surface. Both simulated and measured results show this antenna satisfies the expected 9% bandwidth (5.725–5.875 GHz) for return‐loss ≤ −10 dB, and it is suitable for on‐body communication application. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2623–2627, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24712
0.13‐μM CMOS Q‐band leveled‐LO subharmonic mixer with injection‐locked frequency‐divider quadrature generator
Authors: Su Jen‐Yi , Meng Chinchun , Wu Po‐Yi , Huang Guo‐Wei
Published: August 2009

In this article, a 40‐GHz subharmonic Gilbert down‐conversion mixer with an accurate quadrature local oscillator (LO) input is demonstrated using a standard 0.13‐μm CMOS technology. The quadrature‐output frequency divider is realized by injection‐locked oscillators and is used at the LO port to replace conventional RC‐CR polyphase filters at higher frequencies. Furthermore, the proper Marchand balun at an RF stage is suitable for the standard Si‐based process to generate precisely balanced signals despite the substrate loss. The measured conversion gain is 4 dB at 40 GHz. The IP1dB and IIP3 of −7 dBm and 2 dBm, respectively, are achieved. The measured 3‐dB RF bandwidth is very broad and about 12‐GHz bandwidth when the 10‐MHz IF frequency is fixed. The die size is about 1 mm × 1 mm. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2663–2665, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24714
Resonant homogenization of a dielectric metamaterial
Authors: Felbacq D. , Guizal B. , Bouchitté G. , Bourel C.
Published: August 2009

We investigate numerically and theoretically the homogeneous properties of a metamaterial made of nanorods with a high dielectric constant. The rods have inner resonances leading to an effective magnetic behavior. The influence of various parameters, such as the wavelength, the angle of incidence, and the filling ratio is quantified by means of rigorous numerical computations. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2695–2701, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24717
Photonic bandgap modification in hollow optical fibers integrated with single walled carbon nanotubes
Authors: Pisco Marco , Consales Marco , Penza Michele , Aversa Patrizia , Giordano Michele , Cutolo Antonello , Cusano Andrea
Published: August 2009

Single‐walled carbon nanotubes (SWCNTs) have been infiltrated within the holes of hollow‐core optical fibers (HOFs) by Langmuir‐Blodgett method in order to develop new in‐fiber active and passive optoelectronic devices. Far field transmission characterizations demonstrated HOF's holes successful filling and the SWCNTs' capability to modify the guiding properties of HOFs. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2729–2732, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24725
An adaptive spectroellipsometer for ecological monitoring
Authors: Mkrtchyan F. A. , Krapivin V. F. , Kovalev V. I. , Klimov V. V.
Published: August 2009

In this article, the creation of multichannel polarization optical instrumentation and the use of spectroellipsometric technology for the real‐time ecological control of aquatic environment is discussed. It was shown that spectroellipsometric devices give high precision of measurements of water quality characteristics. Spectroellipsometric multichannel measurements in an aquatic environment are conducted by the algorithms for the recognition and identification of pollutants. Some results of an adaptive spectroellipsometer applications are given. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2792–2795, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24730
Miniaturized high impedance surfaces with angular stability by using zirconium tin titanate substrates and convoluted FSS elements
Authors: Genovesi S. , Costa F. , Cioni B. , Miceli V. , Annino G. , Gallone G. , Levita G. , Lazzeri A. , Monorchio A. , Manara G.
Published: August 2009

A new approach for obtaining metasurfaces realized by using frequency selective surfaces with reduced periodicity printed on a new class of high dielectric constant materials is presented. The proposed engineered ad‐hoc materials and the innovative electromagnetic design provide an improvement of the overall device in terms of compactness and angular stability, as shown by the use of our novel band vs. incidence angles chart. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2753–2758, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24731
Conventional and microwave curing process of epoxy systems: Kinetic analysis and characterization
Authors: Saccone Guido , Amendola Eugenio , Acierno Domenico
Published: August 2009

An investigation about the kinetic of the curing process of an epoxy resin and its mechanical characterization has been performed. An assessment about the existence of the “specific microwave effect” has been carried out and the possible improvement of the microwave absorption of the epoxy resins by the addition of a suscepting material has been studied. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2777–2783, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24735
Numerical and experimental investigation of basic properties of wire medium‐based shortened horn antennas
Authors: Hrabar Silvio , Bonefacic Davor , Muha Damir
Published: August 2009

Recent numerical study predicted a phenomenon of gain increase of a shortened horn antenna by embedding a wire medium‐based slab. Here, we report an experimental verification of this idea by the development of two shortened horn antennas that operate in 10 GHz band: the horn with embedded single‐wire ENZ slab and the horn with embedded double‐wire ENZ slab. These two horn antennas had lengths of 52% and 33% of the length of the optimal horn, respectively. Measured gain was found to be very similar to the gain of the full‐length optimal horn (within 0.1 dB), but in a narrow band (5–12%). In addition, we present numerical results that show that a Drude model is a good starting point for the initial design of a shortened horn, while the required antenna characteristics should be achieved by an additional numerical optimization. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2748–2753, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24736
A stub‐loaded SIR filter with an ultra‐wide rejection band
Authors: Wang Huan , Chu Qing‐Xin
Published: August 2009

A stub‐loaded stepped‐impedance resonator (SIR) filter with an ultra‐wide upper stopband is proposed. For a 20‐dB rejection level, by properly choosing the number and lengths of the stubs, the second, third, and fourth resonances of the SIR filter are pushed to left and the seventh resonance is pushed to right, and all of them show low S21 levels due to the improper external coupling values, while the fifth and sixth resonances are greatly suppressed by a transmission zero. The measured 20‐dB rejection band of a three‐stub SIR filter achieves 17.4 times the designed frequency. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2660–2662, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24740
A high‐pass filter based on modified double‐sided parallel‐strip lines
Authors: Misan S. , Haviv R. , Ackerman D. , Matzner H. , Haridim M.
Published: August 2009

We present a 6th order pseudo high‐pass filter implemented by a modified version of the double‐sided parallel‐strip line, in which the width of the dielectric substrate is identical to the width of the conducting strips. The filter, the associated compact circular balun, and the SMA connectors are designed and simulated by means of the CST Microwave Studio, and implemented on a Rogers 4003C substrate. The experimental results are in good agreement with the simulations, and good scattering properties are achieved. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2691–2694, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24741
A heuristic two‐phase solution approach for the multi‐objective dial‐a‐ride problem
Authors: Parragh Sophie N. , Doerner Karl F. , Hartl Richard F. , Gandibleux Xavier
Published: August 2009

In this article, we develop a heuristic two‐phase solution procedure for the dial‐a‐ride problem with two objectives. Besides the minimum cost objective a client centered objective has been defined. Phase one consists of an iterated variable neighborhood search‐based heuristic, generating approximate weighted sum solutions; phase two is a path relinking module, computing additional efficient solutions. Results for two sets of benchmark instances are reported. For the smaller instances, exact efficient sets are generated by means of the ϵ‐constraint method. Comparison shows that the proposed two‐phase method is able to generate high‐quality approximations of the true Pareto frontier. © 2009 Wiley Periodicals, Inc. NETWORKS, 2009
Good people: a work in progress
Authors: Clayton Alan
Published: August 2009

This article provides some evidence, some insight and some opinion based on a continuously evolving research programme conducted by the Good Agency which attempts to define the reasons that people give to charity. Conclusions are drawn from a variety of research resources and live testing across a wide client base over the last 8 years

Copyright © 2009 John Wiley & Sons, Ltd.
Design of pheromone releasing nanofibers for plant protection
Authors: Hellmann Christoph , Greiner Andreas , Wendorff Joachim H.
Published: August 2009

Plants tend to attract diseases quite similar to human beings. Pesticides tend to be used to control such diseases. An alternative route, at least as far as damages from insects is concerned, envisions the application of pheromones. These cause a disorientation of male insects so that they are no longer able to locate the females, which finally gives rise to suppression of reproduction. The approach considered in this paper is based on the release of pheromones from polymer carriers, in particular, from nanofibers webs as obtained by electrospinning. These may be distributed across the field quite similar to spider webs. The pheromones are required to be incorporated in sufficiently high concentrations in the nanofibers via electrospinning and to be released from the nanofibers for a sufficiently long time expanding over several weeks to months. Polyamide 6 as well as cellulose acetate was used as a polymer carrier in the investigations reported in this contribution. Studies reveal that fluid pheromones can, in fact, be incorporated in the nanofibers to more than 33 wt%. They may undergo a nanoscalar phase separation within the fibers during electrospinning. Furthermore, thermogravimetric studies revealed viain vitrorelease studies that the pheromones are released from the nanofibers in a nearly linear fashion over a period covering many weeks. Copyright © 2009 John Wiley & Sons, Ltd.
Ginkgo‐Extrakt bei Personen mit nachlassender mentaler Leistungsfähigkeit. Studienergebnisse differenziert betrachten
Authors: Kaschel Reiner
Published: August 2009

Ginkgo biloba ist eine der am besten dokumentierten Arzneipflanzen. Ihre größte Verbreitung haben Ginkgo‐Extrakte zur Verbesserung nachlassender Gedächtnisleistungen gefunden. Standardisierte Spezialextrakte wie EGb 761® sind als Arzneimittel zugelassen zur symptomatischen Behandlung von hirnorganisch bedingten geistigen Leistungseinbußen im Rahmen eines therapeutischen Gesamtkonzepts bei dementiellem Syndrom mit der Leitsymptomatik: Gedächtnis‐ und Konzentrationsstörungen, depressive Verstimmung, Schwindel, Ohrensausen, Kopfschmerzen.

Indes weisen zahlreiche Studien darauf hin, dass der Extrakt auch bei Personen ohne jede Hirnleistungsstörung günstige Effekte auf die kognitive Leistung und die emotionale Belastbarkeit hat. Dennoch erscheint eine umfassende Zusammenschau der bisherigen Studienergebnisse zu Ginkgo zunächst verwirrend und widersprüchlich. Es lässt sich jedoch zeigen, dass dies nicht zuletzt auf methodische Probleme einzelner Studien zurückgeht, die sich an der Anwendung und Auswertung psychometrischer Tests festmachen lassen: Häufig hatte Ginkgo keine adäquate Chance, seine Wirksamkeit unter Beweis zu stellen.

Das zeigt die hier referierte aktuelle Übersicht zu Ginkgo, welche Ergebnisse von objektiven psychometrischen Test aus 28 Studien zusammenfasst. Darüber hinaus zeigt die Analyse, dass Ginkgo‐Extrakt sehr spezifische Effekte auf kognitive Funktionen hat, die über die Verbesserung allgemeiner Gedächtnisleistungen hinausgehen: Komplexe Aufmerksamkeits‐ und Intelligenzleistungen werden gefördert, und die Handlungssteuerung verbesserte sich deutlicher als unter Placebo.

Eine neuere Studie von Grass‐Kapanke und Mitarbeitern fand bei Personen mittleren Alters mit sehr leichten kognitiven Einbußen (vMCI) Verbesserungen in eben solchen alltagsrelevanten Gedächtnis‐ und Aufmerksamkeits‐Tests.

Obligate Voraussetzungen einer jeden pharmakologischen Intervention bei gesunden Menschen sind die Sicherheit und gute Verträglichkeit. Diese Conditio sine qua non erfüllt EGb 761®. Die Behandlung mit Dosen bis 240 mg täglich war sicher und gut verträglich.