bluuebunny/crossref_metadata_2025 huggingface dataset:
Texture‐based tissue characterization for high‐resolution CT scans of coronary arteries
Authors: Papadakis Manos , Bodmann Bernhard G. , Alexander Simon K. , Vela Deborah , Baid Shikha , Gittens Alex A. , Kouri Donald J. , Gertz S. David , Jain Saurabh , Romero Juan R. , Li Xiao , Cherukuri Paul , Cody Dianna D. , Gladish Gregory W. , Aboshady Ibrahim , Conyers Jodie L. , Casscells S. Ward
Published: January 2009

We analyze localized textural consistencies in high‐resolution X‐ray (computed tomography) CT scans of coronary arteries to identify the appearance of diagnostically relevant changes in tissue. For the efficient and accurate processing of CT volume data, we use fast wavelet algorithms associated with three‐dimensional isotropic multiresolution wavelets that implement a redundant, frame‐based image encoding without directional preference. Our algorithm identifies textural consistencies by correlating coefficients in the wavelet representation. Copyright © 2009 John Wiley & Sons, Ltd.
Arbitrary Lagrangian Eulerian approximation with remeshing for Navier–Stokes equations
Authors: Murea C. M.
Published: January 2009

An algorithm that allows remeshing in the arbitrary Lagrangian Eulerian (ALE) framework is presented. At every time step, we could triangulate the domain using either uniform size meshes or adapted meshes. We analyze the conditions when two time‐advancing algorithms based on the backward Euler scheme provide identical approximations. Numerical results are presented for Navier–Stokes equations on moving domain. For three academic tests presented in this paper, the uniform size mesh technique provides more accurate results than the classical ALE method, in particular when the domain is expanding particularly fast. Copyright © 2009 John Wiley & Sons, Ltd.
EEAODR: An energy‐efficient ad hoc on‐demand routing protocol for mobile ad hoc networks
Authors: Dhurandher Sanjay Kumar , Misra Sudip , Obaidat Mohammad S. , Bansal Vikrant , Singh Prithvi Raj , Punia Vikas
Published: January 2009

Mobile ad hoc networks (MANETs) are characterized by random, multi‐hop topologies that do not have a centralized coordinating entity or a fixed infrastructure that may change rapidly over time. In addition, mobile nodes operate with portable and finite power sources. In this work, we propose an energy‐efficient routing protocol for MANETs to minimize energy consumption and increase the network's consistency. Traditional works mainly focused on the shortest path‐based schemes to minimize energy, which might result into network failure because some nodes might exhaust fast as they are used repetitively, while some other nodes might not be used at all. This can lead to energy imbalance and to network life reduction. We propose an energy‐efficient ad hoc on‐demand routing protocol that balances energy load among nodes so that a minimum energy level is maintained among nodes and the network life increases. We focused on increasing the network longevity by distributing energy consumption in the network. We also compared the simulation results with a popular existing on‐demand routing protocol in this area, AODV, to establish the superiority of our approach. Copyright © 2009 John Wiley & Sons, Ltd.
On the characteristics of queueing and scheduling at encoding nodes for network coding
Authors: Ma Yi , Li Wei , Fan Pingyi , Letaief K. B. , Liu Xuming
Published: January 2009

Synchronization can greatly influence the performance of network coding. In this paper, we shall investigate the synchronization issue based on the use of queueing theory. We shall first propose a queueing model, referred to as the classic model, to investigate the characteristics of the encoding process. It will be proved that given the packet arrival processes are stationary, i.e. the distribution of the arrival processes does not depend on time, and obey independently and identically Poisson distribution and that the encoding time is exponentially distributed, the output flow will be an asymptotically Poisson flow with the same parameter. Through simulation we shall show that the network is sensitive to the arrival rate of input flows and becomes unstable with the input queue size increasing to infinity. This indicates that the classic coding scheme would impose strict requirements on synchronization over the whole network. In order to address this, we shall propose a combined opportunistic scheduling and encoding (COSE) strategy, in which the classic coding scheme and the traditional forwarding algorithm are well integrated. Theoretical analysis and simulation will demonstrate that the COSE strategy is able to control the input queue sizes and keep the network operating in a stable state while maintaining a relatively high throughput, low blocking probability and small waiting delay under various levels of traffic load. Copyright © 2009 John Wiley & Sons, Ltd.
Stenotrophomonas maltophilia bacteremia in end‐stage renal disease patients receiving maintenance hemodialysis
Authors: Gnanasekaran Isaiarasi , Bajaj Rishi
Published: January 2009

Stenotrophomonas maltophilia is typically a low‐virulence gram‐negative bacterium but can become pathogenic in patients in immunocompromised states and can cause nosocomial infections in the presence of invasive medical devices such as central venous catheters, peritoneal catheters, endotracheal/tracheostomy tubes, and urinary catheters, resulting in a variety of infections. End‐stage renal disease patients are immunocompromised, and S. maltophilia bacteremia has been reported in patients receiving peritoneal dialysis via peritoneal catheters. A significant number of patients receive hemodialysis via central venous catheters, which present a high risk for S. maltophilia infection, but to our knowledge, no case has been reported.
Computer‐based undernutrition screening tool for hemodialysis patients
Authors: Elliott Hazel A. , Robb Lianne
Published: January 2009

BACKGROUND

The purpose of this study was to develop and validate a computer‐based screening tool to identify hemodialysis (HD) patients at risk of undernutrition. The computer‐based undernutrition screening tool identifies HD patients at risk of undernutrition as accurately as subjective global assessment (SGA) carried out by an experienced dietitian.

METHODS

This was an observational study of 122 HD patients from the Royal Infirmary Haemodialysis Unit and the Western General Satellite Haemodialysis Unit, Edinburgh, Scotland. SGA of all participants was carried out, and the results were compared with the results from the computer‐based screening tool, which looked at the following parameters: pre‐dialysis urea <15 mmol/L, albumin <35 g/L, C‐reactive protein (CRP) >10 mg/L, indicating acute phase response, total cholesterol <3.5 mmol/L, >5% weight loss over 3 months, body mass index <20 kg/m2, midarm muscle circumference (MAMC; muscle mass) <10th percentile, tricep skinfold thickness (fat mass) <10th percentile, sex, age, and time on dialysis.

RESULTS

Correlations with SGA results were performed for pre‐dialysis urea (p < 0.001), pre‐dialysis albumin (p < 0.001), CRP (p = 0.005), percentage weight loss (p < 0.001), BMI (p < 0.001), TSF (p < 0.001), and MAMC (p = 0.001). Cholesterol did not reach statistical significance. For clinical reasons, TSF and MAMC were omitted from the final version of the computer‐based screening tool, which comprised pre‐dialysis urea, albumin, CRP, percentage weight loss, and BMI and accounted for 41% of the variability of SGA.

DISCUSSION

The computer‐based screening tool correlated with SGA across the whole range of undernutrition scores (R2 = 0.3406). As the results were based on quantitative data and therefore reproducible with a minimum chance of error, this new tool provides a rapid and easy method of assessing the risk of undernutrition. An outcome study looking at its ability to predict mortality and morbidity is now underway.
Cycle analysis using exhaust heat of SOFC and turbine combined cycle by absorption chiller
Authors: Takezawa Shinya , Wakahara Kenji , Araki Takuto , Onda Kazuo , Nagata Susumu
Published: January 2009

The power generating efficiency of solid oxide fuel cell (SOFC) and gas turbine combined cycle is fairly high. However, the exhaust gas temperature of the combined cycle is still high, about 300°C. Thus, it should be recovered for energy saving, for example, by absorption chiller. The energy demand for refrigeration cooling is recently increasing year by year in Japan. We propose here a cogeneration system by series connection of SOFC, gas turbine and LiBr absorption chiller to convert the exhaust heat to the cooling heat. As a result of cycle analysis of the combined system with 500‐kW‐class SOFC, the bottoming single‐effect absorption chiller can produce a refrigerating capacity of about 120 kW, and the double‐effect absorption chiller can produce a little higher refrigerating capacity of about 130 kW without any additional fuel. But the double‐effect absorption chiller became more expensive and complex than the single‐effect chiller. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 167(1): 49– 55, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20578
Calculation of parameters of equivalent circuit of permanent magnet synchronous motor using PSO with grouped agents
Authors: Zanma Tadanao , Kawamura Tomoya , Ishida Muneaki
Published: January 2009

This paper presents a calculation method for the parameters of high‐frequency equivalent circuits in inverter‐driven permanent magnet synchronous motors (PMSM). The high‐frequency oscillatory current, such as leakage current to the motor frame (common‐mode current) and high‐frequency oscillatory line current (normal‐mode current), are a result of switching in inverter transistors. A parameter search method based on the particle swarm optimization algorithm is proposed. Agents in the algorithm are grouped so that convergence performance is improved. Some simulation results illustrate the effectiveness of the proposed algorithm. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 167(1): 82– 91, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20766
Kinematic transformations for planar multi‐directional pseudodynamic testing
Authors: Mercan Oya , Ricles James M. , Sause Richard , Marullo Thomas
Published: January 2009

The pseudodynamic (PSD) test method imposes command displacements to a test structure for a given time step. The measured restoring forces and displaced position achieved in the test structure are then used to integrate the equations of motion to determine the command displacements for the next time step. Multi‐directional displacements of the test structure can introduce error in the measured restoring forces and displaced position. The subsequently determined command displacements will not be correct unless the effects of the multi‐directional displacements are considered. This paper presents two approaches for correcting kinematic errors in planar multi‐directional PSD testing, where the test structure is loaded through a rigid loading block. The first approach, referred to as the incremental kinematic transformation method, employs linear displacement transformations within each time step. The second method, referred to as the total kinematic transformation method, is based on accurate nonlinear displacement transformations. Using three displacement sensors and the trigonometric law of cosines, this second method enables the simultaneous nonlinear equations that express the motion of the loading block to be solved without using iteration. The formulation and example applications for each method are given. Results from numerical simulations and laboratory experiments show that the total transformation method maintains accuracy, while the incremental transformation method may accumulate error if the incremental rotation of the loading block is not small over the time step. A procedure for estimating the incremental error in the incremental kinematic transformation method is presented as a means to predict and possibly control the error. Copyright © 2009 John Wiley & Sons, Ltd.
Modelling hyperconcentrated flow in the Yellow River
Authors: van Maren D. S. , Winterwerp J. C. , Wu B. S. , Zhou J. J.
Published: January 2009

A large amount of the total sediment load in the Chinese Yellow River is transported during hyperconcentrated floods. These floods are characterized by very high suspended sediment concentrations and rapid morphological changes with alternating sedimentation and erosion in the main channel, and persistent sedimentation on the floodplain. However, the physical mechanisms driving these hyperconcentrated floods are still poorly understood. Numerical modelling experiments of these floods reveal that sedimentation is largely caused by large vertical concentration gradients, both in the channel during the rising stage of the flood, as well as on the floodplains, during a later stage of the flood. These vertical concentration gradients are large because the turbulent mixing rates are reduced by the increased sediment‐induced density gradients, resulting in a positive feedback mechanism that produces high deposition rates. Erosion prevails when the sediment is largely held in suspension due to hindered settling, and is strengthened by the reduced wetted cross‐section caused by massive sedimentation on the floodplain. Observed patterns of erosion and sedimentation during these floods can be qualitatively reproduced with a numerical model in which sediment‐induced density effects and hindered settling are included. Copyright © 2009 John Wiley & Sons, Ltd.
Rituximab therapy for chronic lymphocytic leukaemia
Authors: Chaplin Steve
Published: January 2009

Chronic lymphocytic leukaemia (CLL) can vary in severity, with some patients requiring chemotherapy while others may not require treatment at all. Rituximab has been evaluated as a first‐line treatment option for CLL in combination with fludarabine and cyclophos‐phamide in patients requiring chemotherapy, and a licence application has been made. In this article, we consider the evidence for rituximab, and its potential place in therapy. Copyright © 2008 John Wiley & Sons, Ltd.
Response of hydrological processes to land‐cover and climate changes in Kejie watershed, south‐west China
Authors: Ma Xing , Xu Jianchu , Luo Yi , Prasad Aggarwal Shiv , Li Jiatong
Published: January 2009

Land‐cover/climate changes and their impacts on hydrological processes are of widespread concern and a great challenge to researchers and policy makers. Kejie Watershed in the Salween River Basin in Yunnan, south‐west China, has been reforested extensively during the past two decades. In terms of climate change, there has been a marked increase in temperature. The impact of these changes on hydrological processes required investigation: hence, this paper assesses aspects of changes in land cover and climate. The response of hydrological processes to land‐cover/climate changes was examined using the Soil and Water Assessment Tool (SWAT) and impacts of single factor, land‐use/climate change on hydrological processes were differentiated. Land‐cover maps revealed extensive reforestation at the expense of grassland, cropland, and barren land. A significant monotonic trend and noticeable changes had occurred in annual temperature over the long term. Long‐term changes in annual rainfall and streamflow were weak; and changes in monthly rainfall (May, June, July, and September) were apparent. Hydrological simulations showed that the impact of climate change on surface water, baseflow, and streamflow was offset by the impact of land‐cover change. Seasonal variation in streamflow was influenced by seasonal variation in rainfall. The earlier onset of monsoon and the variability of rainfall resulted in extreme monthly streamflow. Land‐cover change played a dominant role in mean annual values; seasonal variation in surface water and streamflow was influenced mainly by seasonal variation in rainfall; and land‐cover change played a regulating role in this. Surface water is more sensitive to land‐cover change and climate change: an increase in surface water in September and May due to increased rainfall was offset by a decrease in surface water due to land‐cover change. A decrease in baseflow caused by changes in rainfall and temperature was offset by an increase in baseflow due to land‐cover change. Copyright © 2009 John Wiley & Sons, Ltd.
Termination as a therapeutic intervention when treating children who have experienced multiple losses
Authors: Many Michele M.
Published: January 2009

Children who have endured traumatizing events often have a history of prior disruptions and losses which also have been experienced as traumatic. Termination of therapy with these children, therefore, provides a unique opportunity for the clinician to provide the traumatized child and his or her caregiver with a new experience of loss; one that is controlled, predictable, and paced. Through this experience, the child and caregiver can develop a new model for loss, one that permits for losses that are a natural part of healthy growth and change. This article outlines one approach to utilizing termination as an integral component of the therapeutic process with infants, toddlers, and preschoolers and their caregivers. Using a psychodynamic model and working dyadically with the child and the caregiver, termination is approached as a primary intervention, pivotal to the successful treatment of this vulnerable population.
Land and water management of tidal lowlands: Experiences in Telang and Saleh, South Sumatra
Authors: Suprianto Hartoyo , Ravaie Erwin , Irianto Sumarjo Gatot , Susanto Robiyanto H. , Schultz Bart , Suryadi F. X. , Van Den Eelaart Ad
Published: January 2009

Indonesia has available over 20 million ha of tidal lowlands. In their natural state these are generally waterlogged areas that may be regularly inundated for prolonged periods. Almost 4 million ha of these tidal lowlands have been reclaimed, partly by spontaneous settlers and partly by the government. While the reclaimed areas mainly consist of clay and especially the government schemes have a rational layout, they generally have a good potential for agricultural development, with a rice crop in the wet season and a second rice crop, or a dry food crop, in the dry season.

For successful tidal lowland management there is, however, a need for an integrated approach, based on effective water management in combination with adequate farming systems technology and post‐harvest activities. In order to investigate and promote such an integrated approach the programme Land and Water Management Tidal Lowlands (LWMTL) was implemented in the period 2004–06 in three pilot areas in the Musi delta, South Sumatra. It turned out that high yields of field dry husked rice (gabah) up to 8 t ha−1 could be obtained. The paper gives an overview of the programme and the main results. Copyright © 2009 John Wiley & Sons, Ltd.
The immunoglobulin‐like cell adhesion molecule hepaCAM modulates cell adhesion and motility through direct interaction with the actin cytoskeleton
Authors: Moh Mei Chung , Tian Qifeng , Zhang Ting , Lee Lay Hoon , Shen Shali
Published: January 2009

Previously, we reported the identification of a novel immunoglobulin‐like cell adhesion molecule hepaCAM that promotes cell–extracellular matrix (ECM) interactions including cell adhesion and motility. Cell–ECM interactions are known to be directed by the actin cytoskeleton. In this study, we examined the association of hepaCAM with the actin cytoskeleton. We found that hepaCAM was partially insoluble in Triton X‐100 and colocalized with the actin cytoskeleton on the plasma membrane. Disruption of F‐actin decreased the detergent insolubility and disturbed the subcellular localization of hepaCAM. Coimmunoprecipitation and F‐actin cosedimentation assays revealed that hepaCAM directly bound to F‐actin. In addition, we constructed three N‐ and C‐terminal domain‐deleted mutants of hepaCAM to determine the actin‐binding region as well as to evaluate the effect of the domains on the biological function of hepaCAM. Detergent solubility assays showed that the cytoplasmic domain of hepaCAM might be required for actin association. However, deletion of either the extracellular or the cytoplasmic domain of hepaCAM abolished actin coprecipitation as well as delayed cell–ECM adhesion and cell motility. The data suggest that an intact hepaCAM protein is critical for establishing a stable physical association with the actin cytoskeleton; and such association is important for modulating hepaCAM‐mediated cell adhesion and motility. J. Cell. Physiol. 219: 382–391, 2009. © 2009 Wiley‐Liss, Inc.
Thermodynamic and NMR investigations on the adsorption mechanism of puerarin with oligo‐β‐cyclodextrin‐coupled polystyrene‐based matrix
Authors: Yang Li , Zhang Haiyang , Tan Tianwei , Rahman Ata Ur
Published: January 2009

BACKGROUND: Adsorption of puerarin on native resin polystyrene (PS) and oligo‐β‐cyclodextrin‐coupled matrix (PS‐CDP) was studied for interactions between the adsorbents and the adsorbates. The sorption mechanism on PS‐CDP was investigated using the isosteric heat approach and nuclear magnetic resonance (NMR) spectroscopy.

RESULTS: The equilibrium adsorption data of puerarin on the two matrices PS and PS‐CDP (polystyrene‐based matrix before and after coupling by oligo‐β‐cyclodextrin) in the temperature range 288–318 K were well fitted to the Freundlich adsorption isotherm model. The energetic heterogeneity of the media was observed based on the result that the values of isosteric enthalpy were quantitatively correlated with the fractional loading of puerarin adsorption. The more heterogeneous surface of PS‐CDP compared with PS was attributed to the complexation between puerarin and β‐cyclodextrin (β‐CD). NMR studies validated the formation of an inclusion complex puerarin/β‐CD.

CONCLUSION: Thermodynamic and NMR studies confirmed that multi‐interaction cooperatively governed the isolation of puerarin from aqueous solution on PS‐CDP matrix. Copyright © 2009 Society of Chemical Industry
Atmospheric centres of action associated with the Atlantic ITCZ position
Authors: Souza Paula , Cavalcanti Iracema Fonseca Albuquerque
Published: January 2009

Relationships between Atlantic extra‐tropical features and Intertropical Convergence Zone (ITCZ) position close to Northeast Brazil are discussed, on the basis of atmosphere and ocean patterns in DJF and April. Composites for three situations were analysed. In the first composite, years with extreme positive North Atlantic Oscillation Index (NAOI) in DJF and the ITCZ displaced southward in April were selected. The other two composites were related only to anomalous ITCZ positions—either south or north of the equator—in April. The physical mechanism for the relation between the NAOI and the ITCZ is the influence of the southern North Atlantic Oscillation (NAO) centre on the North Atlantic subtropical high, the sea surface temperature (SST) and the intensity of the trade winds; however, this situation occurred in only a few years. Analysis of the other situations indicated the influence of a dominant mode of variability over the North and South Atlantic Oceans that affects the ITCZ position. Over the North Atlantic, this mode was related to a shifting of the NAO pattern, which modified the position of the North Atlantic subtropical high. Over the South Atlantic, this mode indicated an extra‐tropical centre of action associated with displacement of the South Atlantic subtropical high. A proposed index for monitoring ITCZ position, named the North Atlantic Index (NAI), was calculated from sea level pressure (SLP) anomalies in the two centres of action of the North Atlantic in DJF, which are related to the shifting of the NAO. Although the NAO index is related to atmospheric/oceanic features associated with ITCZ displacement, the new index presented higher and more organized correlations with atmospheric and oceanic conditions linked to ITCZ behaviour and can be useful even when the NAO is not extreme. Copyright © 2009 Royal Meteorological Society
Combination of large volume sample stacking and reversed pH junction in capillary electrophoresis for online preconcentration of glycoforms of recombinant human erythropoietin
Authors: Liu Jing , Liu Zhen , Kang Mingchao , Liu Sichang , Chen Hong‐Yuan
Published: January 2009

Resolution of glycoforms of a glycoprotein is usually a challenge for an analytical chemist, which is often associated with the difficulty of detecting a large number of glycoforms with sufficient sensitivity. CE is the main workhorse for the analysis of glycoproteins; however, the current methods are only applicable to high concentration samples. Therefore, the development of online preconcentration approaches is important for the CE analysis of glycoproteins. In this study, we present a combined strategy for online preconcentrating glycoforms of glycoproteins, which couples two individual online preconcentration techniques, i.e., large volume sample stacking (LVSS) and reversed pH junction (RPHJ). LVSS allows for compressing a large injected sample volume into a narrow sample zone, contributing to the main sensitivity improvement, while RPHJ coordinates the preconcentration process to improve the resolution. This strategy was verified with recombinant human erythropoietin (rhEPO), a typical glycoprotein, as the test analyte, and the effects of experimental conditions were investigated. It was found that there is a compromise between sensitivity enhancement and resolution for online preconcentration of glycoprotein glycoforms. By using this strategy, the detection sensitivity can be improved by 50–100 times for rhEPO.
Pressurized CEC with gradient elution for separation of flavonoids from corn
Authors: Wang Shujuan , Jia Li , Chen Deping
Published: January 2009

A pressurized CEC (pCEC) method with gradient elution was developed for the analysis of flavonoids in two genetically modified corns and five nongenetically modified corns. The pCEC separation of flavonoids was performed on a monolithic silica‐ODS column with UV detection at 270 nm. The effects of the concentration of organic solvent in the mobile phase, pH of the electrolyte buffer, applied voltage, and the gradient elution conditions were evaluated systematically. Gradient elution mode was used as an online concentration method to improve the detection sensitivity of flavonoids. Compared to the conventional injection (0.2 μL), there were 9‐ to 20‐fold improvements in the detection sensitivity at the injection volume of 5 μL without adverse effect on the band broadening and the separation resolution. The LODs for the six flavonoids were in the range of 6.5–46 ng/mL under the gradient elution conditions. The developed gradient pCEC method was applied to evaluate flavonoids in various types of corns. The contents of flavonoids in genetically modified corns and nongenetically modified corns were compared.
Multigrid methods for the symmetric interior penalty method on graded meshes
Authors: Brenner S. C. , Cui J. , Sung L.‐Y.
Published: January 2009

The symmetric interior penalty (SIP) method on graded meshes and its fast solution by multigrid methods are studied in this paper. We obtain quasi‐optimal error estimates in both the energy norm and the L2 norm for the SIP method, and prove uniform convergence of the W‐cycle multigrid algorithm for the resulting discrete problem. The performance of these methods is illustrated by numerical results. Copyright © 2009 John Wiley & Sons, Ltd.
Vacuum filling process for electrolyte in enhancing electrochromic polymer window assembly
Authors: Xu Chunye , Ma Chao , Kong Xiangxing , Taya Minoru
Published: January 2009

The electrochromic (EC) smart window developed in our group is based on EC polymers. This is a multilayer structured device, with an ion conductive electrolyte sandwiched between the EC and ion storage layers. Achieving a void free and uniform electrolyte layer without damaging the EC polymer thin film is the key process, which strongly affects the mass production of large sized electrochromic window (ECW). We developed a vacuum filling station system for ECW. A specially shaped ECW with inlet port was designed and used in the test. Dimension of the cavity between two layers was controlled by glass beads spacer (30–50 µm). Using the principle of fluid capillary effect, low vacuum pressure (∼100 µm Hg) helps to accelerate liquid electrolyte (propylene carbonate dissolved with lithium perchlorate) filling into the cavity without bubbles. The developed vacuum filling station system demonstrated enhancing ECW assembly. Copyright © 2009 John Wiley & Sons, Ltd.
Synthesis and characterization of new poly(ether amide)s based on a new cardo monomer
Authors: Maji Samarendra , Sen Suman Kumar , Dasgupta Barnali , Chatterjee Shyambo , Banerjee Susanta
Published: January 2009

A new cardo diamine monomer 3, 3‐bis‐[4‐{2′trifluoromethyl 4′‐(4″‐aminophenyl) phenoxy} phenyl]‐2‐phenyl‐2, 3‐dihydro‐isoindole‐1‐one (4) has been synthesized from potentially cheap phenolphthalein as the starting material. This diamine was used for the synthesis of a new poly(ether amide) and two co‐poly(ether amide)s using 4, 4′‐diaminodiphenyl ether (ODA) as co‐monomer by direct solution polycondensation with 5‐t‐butyl iso‐phthalic acid. These new polymers showed inherent viscosities of 0.48–0.62 dL g−1. The resulting poly(ether amide) and co‐poly(ether amide)s were readily soluble in polar aprotic solvents like NMP, DMF, DMAc, DMSO, and pyridine. The polymers have been fully characterized by 1H and 13C NMR, FTIR spectroscopy, and elemental analysis. These polymers showed glass transition temperatures in the range of 267–310°C. Thermogravimetric analysis indicated high thermal stability of these polymers at 5 and 10% weight loss temperature in air above 357°C and 419°C, respectively. The poly(ether amide) films cast from DMAc were flexible with tensile strength up to 91 MPa, elongations at break up to 11%, and modulus of elasticity up to 1.82 GPa. X‐ray diffraction measurements indicate the amorphous nature of the poly(ether amide)s. Copyright © 2009 John Wiley & Sons, Ltd.
Using the protein chip interface with quadrupole time‐of‐flight mass spectrometry to directly identify peaks in SELDI profiles – initial evaluation using low molecular weight serum peaks
Authors: Peng Jianhe , Stanley Anthea J. , Cairns David , Selby Peter J. , Banks Rosamonde E.
Published: January 2009

Mass spectrometric profiling, particularly in the form of SELDI, has been used in many studies, particularly in attempts to generate diagnostic serum profiles. Several studies have generated promising results but one of the limitations is the inability to identify easily potential discriminatory peaks. This may enable specific assays to be developed and increased biological insight. We describe the first systematic technical evaluation of the ProteinChip interface coupled to a tandem mass spectrometer which allows direct sequencing of peptides <6000 Da, and describe the direct sequence identification of 21 peaks commonly observed in serum samples. Additionally we describe for the first time the use of on‐chip acetylation to assist in the validation of sequence identification.
Health‐related quality‐of‐life in patients with head‐and‐neck cancer in Sri Lanka: psychometric properties of the ‘Sinhala’ version of the EORTC QLQ‐H&N35
Authors: Jayasekara Harindra , Rajapaksa Lalini C. , Aaronson Neil K.
Published: January 2009

Objective: To translate and validate the ‘Sinhala’ language version of the European Organization for Research and Treatment of Cancer head‐and‐neck cancer‐specific health‐related quality‐of‐life questionnaire module, the QLQ‐H&N35, for use in Sri Lanka.

Methods: Psychometric testing assessed the hypothesized scale structure, scale reliability, construct validity and acceptability of the translated version of the QLQ‐H&N35 in a consecutive series of 196 newly diagnosed head‐and‐neck cancer patients, recruited from tertiary‐care oncology treatment centres in Sri Lanka.

Results: Compliance was high (97.5%), although nearly 40% of patients required assistance with completion of the questionnaire. Twenty‐four sexually inactive patients declined to answer one or both items of the sexuality scale. Multi‐trait scaling confirmed the overall scale structure, with good item‐convergent (100%) and ‐discriminant (93.8%) validity, and scaling success (86.8%) rates. Cronbach's alpha coefficients exceeded 0.70 for all scales, except problems with sexuality (0.60) and problems with senses (0.61), which also evidenced a lower scaling success rate (50%). Confirmation of construct validity included satisfactory results for inter‐scale correlations and known‐groups comparisons for most scales; most correlations were statistically significant (p<0.01), with conceptually related scales showing relatively higher correlation. Most scale scores were able to discriminate clearly between pre‐ and current treatment patients.

Conclusions: Results of the study provide strong support for the psychometric robustness of the ‘Sinhala’ version of the QLQ‐H&N35. It may be advisable to interpret the two items assessing sensory problems separately, and to elicit information on sexuality from only those who are sexually active. Copyright © 2009 John Wiley & Sons, Ltd.
Forced inspiratory flow volume curve in healthy young children
Authors: Vilozni Daphna , Efrati Ori , Barak Asher , Yahav Yakov , Augarten Arie , Bentur Lea
Published: January 2009

Introduction

Spirometry testing should include both expiratory and inspiratory measurements. Inspiratory forced maneuvers can demonstrate extrathoracic airway abnormalities, of which various symptoms may suggest asthma. However, the inspiratory portion of the forced flow/volume maneuver in young healthy children has not yet been described.

Objectives

To document and analyze the forced inspiratory flow volume curve indices in healthy young children.

Settings and Participants

Healthy preschool children (age 2.5–6.5 years) from community kindergartens around Israel.

Methods

The teaching method included multi‐target, interactive spirometry games and accessory games for inspiration (e.g., inspiratory whistle).

Results

One hundred and fourteen out of a total of 157 children performed duplicate full adequate inspiratory maneuvers. Repeatability between two maneuvers was 5.6%, 4.0%, 5.1%, 7.3% for inspiratory capacity (IC), forced inspiratory vital capacity (FIVC), peak inspiratory flow (PIF), and mid inspiratory flow (FIF50). Inspiratory flow indices were significantly lower than the expiratory flow indices. The time to reach PIF was significantly longer (mean ± SD; 229 ± 21 msec) than the time to reach peak expiratory flow (92 ± 8 msec; P < 0.0001). The shape of the inspiratory curve was parabolic and did not vary with age. The formed predicted equations were in agreement with the extrapolated values for older healthy children.

Conclusions

The majority of healthy young children can perform reliable maximum inspiratory flow volume curves. Our results provide a framework of reference equations for maximum inspiratory flow volume curve in the young children. The clinical applications of these equations have to be explored. Pediatr Pulmonol. 2009; 44:105–111. © 2009 Wiley‐Liss, Inc.
Hg3In2Te6‐based photodiodes for fiber optic communication
Authors: Kosyachenko L. A. , Kabanova I. S. , Sklyarchuk V. M. , Sklyarchuk O. F. , Rarenko I. M.
Published: January 2009

Schottky barrier photodiodes obtained by vacuum evaporation of the semi‐transparent film over the surface of single crystalline Hg3In2Te6 substrates pre‐treated by Ar ion bombardment. The responsivity maximum of the photodiodes is at the wavelength of 1.55 μm, corresponding to the transmission window in silica glass fiber with the minimal optical losses. The dark current in the diodes is determined by generation‐recombination processes in the space‐charge region and quantitatively governed by the Sah–Noyce–Shockley theory. A comparison of the photoelectric parameters of Hg3In2Te6 and Ge photodiodes is reported. The speed of the photodiode response is in the range 10–8 s to 10–7 s. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ground state magnetization distribution and characteristic width of head to head domain wall in Fe‐rich amorphous microwire
Authors: Gudoshnikov S. A. , Grebenshchikov Yu. B. , Ljubimov B. Ya. , Palvanov P. S. , Usov N. A. , Ipatov M. , Zhukov A. , Gonzalez J.
Published: January 2009

The total magnetic charges of head to head domain walls, Q = 〈Mz〉 S, are measured for a family of amorphous glass‐coated Fe‐rich microwires by means of time integration of the electro‐motive force signals induced in a pick‐up coil wound around the wire. Here 〈Mz〉 is the average longitudinal wire magnetization and S is the cross‐section of the wire metallic core. The measured values of 〈Mz〉 = 1100–1200 emu/cm3 are close to the wire saturation magnetization. This means that Fe‐rich microwires of given family are nearly uniformly magnetized in its ground state, far from the wire ends. The characteristic width of the head to head domain wall is estimated to be δ ∼ (40–75) d, depending on the wall velocity, where d is the metallic core diameter. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Pressure and temperature tuning of InGaP/AlGaInP laser diodes from red to yellow
Authors: Bercha A. , Bohdan R. , Trzeciakowski W. , Dybała F. , Piechal B. , Sanayeh M. Bou , Reufer M. , Brick P.
Published: January 2009

Red laser diodes emitting at 636 nm and 645 nm are studied as a function of pressure up to 20 kbar and temperature from 300 K down to 80 K. The 636 nm samples reveal anomalous L –I –V dependence at low temperatures and at high pressures. The 645 nm samples do not show these anomalies and can be tuned by pressure and temperature down to 575 nm, i.e., in the 70 nm range with powers above 200 mW and low threshold currents. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Rapid thermal annealing temperature dependence of noise properties in Au/n‐GaAs Schottky diodes with embedded InAs quantum dots in asymmetric In0.2Ga0.8As wells
Authors: Arpatzanis N. , Hastas N. A. , Dimitriadis C. A. , Konstantinidis G. , Charitidis C. , Song J. D. , Choi W. J. , Lee J. I.
Published: January 2009

The effect of rapid thermal annealing temperature on the trap properties of Au/n‐GaAs Schottky diodes with embedded InAs quantum dots in asymmetric In0.2Ga0.8As wells have been investigated by capacitance–voltage (C –V) and low frequency noise (LFN) measurements in both reverse and forward bias regimes. The current noise spectra show 1/f behaviour and generation–recombination (g–r) noise, attributed to uniformly distributed traps in energy and to a discrete trap level in the energy band‐gap of the GaAs capping layer, respectively. The experimental results show that the annealing temperature is closely related with the level of these noise sources. The apparent doping concentrations, calculated from the C –V characteristics, indicate that the density of trapping states near the buffer layer interface is increased as the annealing temperature increases. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Two‐dimensional photonic crystals for mid‐infrared quantum dot intersublevel emission
Authors: Houel Julien , Homeyer Estelle , Checoury Xavier , Laurent Stephane , Fishman Guy , Sauvage Sebastien , Boucaud Philippe , Guilet Stephane , Braive Remi , Miard Audrey , Lemaitre Aristide , Sagnes Isabelle
Published: January 2009

We have fabricated two‐dimensional photonic crystals for the mid‐infrared spectral range. These photonic crystals are engineered in order to show optical modes in resonance with quantum dot intersublevel transitions. A novel fabrication technique was developed to obtain suspended membranes in a planar geometry. The membranes are 3 μm thick and the lattice periodicities vary between 3.5 μm to 6.5 μm. We show that the photonic crystals modes can be probed by the room temperature emissivity using a photomodulation technique. Bloch‐modes of the photonic crystals are observed around 11 μm wavelength. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electrical transport properties of a single wall carbon nanotube network
Authors: Hwang J. S. , Kim H. T. , Kim H. K. , Son M. H. , Hwang S. W. , Ahn D.
Published: January 2009

A single wall carbon nanotube (SWCNT) network is fabricated and its electronic transport properties are investigated. It shows a typical p‐type field‐effect‐transistor (FET) behavior and nonlinearities in the source current‐source bias characteristics. The network also exhibits incomplete turn‐off and a small mobility. These characteristics are explained by the fact that the network is a mixture of metallic and semiconducting SWCNTs connecting with one another. Various cross junctions such as SWCNT (semiconducting)‐SWCNT (semiconducting), SWCNT (semiconducting)‐SWCNT (metallic) are the source of nonlinearities and the small mobility. Incomplete turn‐off can be explained by the parallel conduction paths consisting of metallic SWCNTs which are insensitive to the gate bias. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Small‐signal cross‐gain modulation and crosstalk characteristics of quantum dot semiconductor optical amplifiers at 1.3 μm
Authors: Kim J. , Laemmlin M. , Meuer C. , Liebich S. , Eisenstein G. , Kovsh A. R. , Mikhrin S. S. , Krestnikov I. L. , Bimberg D.
Published: January 2009

We present experimental and numerical results of the high‐speed small‐signal cross‐gain modulation (XGM) and crosstalk of quantum‐dot (QD) semiconductor optical amplifiers (SOAs) operating at 1.3 μm. The measured small‐signal XGM responses at various injection currents show that they can be enhanced by injecting more carriers to the QD carrier reservoir. The calculated results of gain saturation in QD SOAs, based on multiple couple‐rate equations, demonstrates that the enhanced XGM responses at high injection current is due to the transition of the main XGM mechanism from slow total carrier density depletion to ultrafast spectra hole burning. The calculated small‐signal crosstalk becomes larger at high injection current, which is similar to the high‐speed XGM responses. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Improvement of seminal parameters with Prelox®: a randomized, double‐blind, placebo‐controlled, cross‐over trial
Authors: Stanislavov R. , Nikolova V. , Rohdewald P.
Published: January 2009

In a randomly allocated, double‐blind, placebo‐controlled, cross‐over design, 50 infertile patients were treated for 1 month with placebo or a combination of l‐arginine aspartate and Pycnogenol® (Prelox®). Semen samples were examined at 4 week intervals according to WHO criteria. Treatment with Prelox increased significantly the semen volume, concentration of spermatozoa, percentage of motile spermatozoa and percentage of spermatozoa with normal morphology compared with placebo. The placebo had no influence on the parameters of seminological analysis. Intake of Pycnogenol for 1 month improved the fertility index to normal values. After treatment, the fertility index decreased again to infertile status. No unwanted effects were reported. Prelox seems to be a promising alternative to treat patients with mild infertility. Copyright © 2009 John Wiley & Sons, Ltd.
Doubly robust generalized estimating equations for longitudinal data
Authors: Seaman Shaun , Copas Andrew
Published: January 2009

A popular method for analysing repeated‐measures data is generalized estimating equations (GEE). When response data are missing at random (MAR), two modifications of GEE use inverse‐probability weighting and imputation. The weighted GEE (WGEE) method involves weighting observations by their inverse probability of being observed, according to some assumed missingness model. Imputation methods involve filling in missing observations with values predicted by an assumed imputation model. WGEE are consistent when the data are MAR and the dropout model is correctly specified. Imputation methods are consistent when the data are MAR and the imputation model is correctly specified.

Recently, doubly robust (DR) methods have been developed. These involve both a model for probability of missingness and an imputation model for the expectation of each missing observation, and are consistent when either is correct. We describe DR GEE, and illustrate their use on simulated data. We also analyse the INITIO randomized clinical trial of HIV therapy allowing for MAR dropout. Copyright © 2009 John Wiley & Sons, Ltd.
Confidence interval construction for a difference between two dependent intraclass correlation coefficients
Authors: Ramasundarahettige Chinthanie F. , Donner Allan , Zou G. Y.
Published: January 2009

Inferences for the difference between two dependent intraclass correlation coefficients (ICCs) may arise in studies in which a sample of subjects are each assessed several times with a new device and a standard. The ICC estimates for the two devices may then be compared using a test of significance. However, a confidence interval for a difference between two ICCs is more informative since it combines point estimation and hypothesis testing into a single inference statement. We propose a procedure that uses confidence limits for a single ICC to recover variance estimates needed to set confidence limits for the difference. An advantage of this approach is that it provides a confidence interval that reflects the underlying sampling distribution. Simulation results show that this method performs very well in terms of overall coverage percentage and tail errors. Two data sets are used to illustrate this procedure. Copyright © 2009 John Wiley & Sons, Ltd.
Sample size requirements to detect an intervention by time interaction in longitudinal cluster randomized clinical trials
Authors: Heo Moonseong , Leon Andrew C.
Published: January 2009

In designing a longitudinal cluster randomized clinical trial (cluster‐RCT), the interventions are randomly assigned to clusters such as clinics. Subjects within the same clinic will receive the identical intervention. Each will be assessed repeatedly over the course of the study. A mixed‐effects linear regression model can be applied in a cluster‐RCT with three‐level data to test the hypothesis that the intervention groups differ in the course of outcome over time. Using a test statistic based on maximum likelihood estimates, we derived closed‐form formulae for statistical power to detect the intervention by time interaction and the sample size requirements for each level. Importantly, the sample size does not depend on correlations among second‐level data units and the statistical power function depends on the number of second‐ and third‐level data units through their product. A simulation study confirmed that theoretical power estimates based on the derived formulae are nearly identical to empirical estimates. Copyright © 2009 John Wiley & Sons, Ltd.
The role of music preferences in early adolescents’ friendship formation and stability
Authors: Selfhout Maarten H.W. , Branje Susan J.T. , ter Bogt Tom F.M. , Meeus Wim H.J.
Published: January 2009

The present study examines the role of similarity in music preferences in the formation and discontinuation of friendships over a 1‐year period. Questionnaire data were gathered from 283 Dutch same‐sex mutual best friends (mean age=12.97) in two waves with a 1‐year interval. Results show consistent evidence for high similarity in specific music dimensions among friends at both waves. Moderate similarity was found in the overall patterning of preferences for music genres at both waves, even after controlling for similarity in social background. Specific music similarity in more non‐mainstream music dimensions and overall music similarity at Wave 1 were related to selecting a new friend at Wave 2. However, similarity in music preferences was not related to the discontinuation of an existing friendship at Wave 2. Thus, results suggest that similarity in music preferences is related to friendship formation, and not to friendship discontinuation.