bluuebunny/crossref_metadata_2025_split huggingface dataset:
Exhaled breath condensate MMP‐9 levels in children with bronchiectasis
Authors: Karakoc Gulbin Bingol , Inal Ayfer , Yilmaz Mustafa , Altintas Derya Ufuk , Kendirli Seval Guneser 
Published: September 2009

AbstractBronchiectasis (BE) is still an important cause of chronic supurative respiratory diseases in developing countries. Neutrophil‐derived proteases such as neutrophil elastase and matrix metalloproteases (MMPs) are implicated in causing airway damage in chronic pulmonary disease. In this study, we aimed to evaluate the MMP‐9 and its natural tissue inhibitors of metalloproteinases (TIMP‐1) levels utilizing the exhaled breath condensate (EBC) method and their relationship with radiological findings and pulmonary functions in children with BE.Thirty‐eight children with BE and 12 healthy children were included: Group 1 (cystic fibrosis [CF] BE), Group 2 (non‐CF BE), Group 3 (control group). High‐resolution computerized tomography (HRCT) scores were calculated according to the anatomic extent of BE. Pulmonary function tests were performed, and MMP‐9 and TIMP‐1 levels in EBC were analyzed by ELISA.Exhaled breath condensate MMP‐9 level was 48.9 ± 26.8 ng/ml for Group 1, and for Group 2, 42.8 ± 18.1 ng/ml; and for Group 3, 30 ± 3.7 ng/ml. Although no statistically significant difference was found between the Groups 1 and 2, a significant difference was detected between these groups and controls. No statistically significant difference was found in TIMP‐1 levels regarding all groups. EBC MMP‐9 levels were inversely correlated with pulmonary functions test, and positively with HRCT scores and annual number of pulmonary infections.In conclusion, this study showed that EBC of children with both CF BE and non‐CF BE contained higher levels of MMP‐9 in comparison to controls. We suggest that EBC MMP‐9 level may be a useful marker of airway injury in patients with BE however prospective studies are needed. Pediatr Pulmonol. 2009; 44:1010–1016. ©2009 Wiley‐Liss, Inc.
Local grand unification in the heterotic landscape
Authors: Schmidt J. 
Published: September 2009

AbstractWe consider the possibility that the unification of the electroweak interactions and the strong force arises from string theory, at energies significantly lower than the string scale. As a tool, an effective grand unified field theory in six dimensions is derived from an anisotropic orbifold compactification of the heterotic string. It is explicitly shown that all anomalies cancel in the model, though anomalous Abelian gauge symmetries are present locally at the boundary singularities. In the supersymmetric vacuum additional interactions arise from higher‐dimensional operators. We develop methods that relate the couplings of the effective theory to the location of the vacuum, and find that unbroken discrete symmetries play an important role for the phenomenology of orbifold models. An efficient algorithm for the calculation of the superpotential to arbitrary order is developed, based on symmetry arguments. We furthermore present a correspondence between bulk fields of the orbifold model in six dimensions, and the moduli fields that arise from compactifying four internal dimensions on a manifold with non‐trivial gauge background.
Theory of peak coalescence in Fourier transform ion cyclotron resonance mass spectrometry
Authors: Boldin Ivan A. , Nikolaev Eugene N. 
Published: September 2009

AbstractPeak coalescence, i.e. the merging of two close peaks in a Fourier transform ion cyclotron resonance (FTICR) mass spectrum at a high number of ions, plays an important role in various FTICR experiments. In order to describe the coalescence phenomenon we would like to propose a new theory of motion for ion clouds with close mass‐to‐charge ratios, driven by a uniform magnetic field and Coulomb interactions between the clouds. We describe the motion of the ion clouds in terms of their averaged drift motion in crossed magnetic and electric fields. The ion clouds are considered to be of constant size and their motion is studied in two dimensions. The theory deals with the first‐order approximation of the equations of motion in relation to dm/m, where dm is the mass difference and m is the mass of a single ion. The analysis was done for an arbitrary inter‐cloud interaction potential, which makes it possible to analyze finite‐size ion clouds of any shape. The final analytical expression for the condition of the onset of coalescence is found for the case of uniformly charged spheres. An algorithm for finding this condition for an arbitrary interaction potential is proposed. The critical number of ions for the peak coalescence to take place is shown to depend quadratically on the magnetic field strength and to be proportional to the cyclotron radius and inversely proportional to the ion masses. Copyright © 2009 John Wiley & Sons, Ltd.
Structural characterization and identification of iridoid glycosides, saponins, phenolic acids and flavonoids in Flos Lonicerae Japonicae by a fast liquid chromatography method with diode‐array detection and time‐of‐flight mass spectrometry
Authors: Qi Lian‐Wen , Chen Chun‐Yun , Li Ping 
Published: September 2009

AbstractA fast liquid chromatography method with diode‐array detection (DAD) and time‐of‐flight mass spectrometry (TOF‐MS) has been developed for analysis of constituents in Flos Lonicerae Japonicae (FLJ), a traditional Chinese medicine derived from the flower bud of Lonicera japonica. The chromatographic analytical time decreased to 25 min without sacrificing resolution using a column packed with 1.8‐µm porous particles (4.6 × 50 mm), three times faster than the performance of conventional 5.0‐µm columns (4.6 × 150 mm). Four major groups of compounds previously isolated from FLJ were structurally characterized by DAD‐TOF‐MS: iridoid glycosides showed maximum UV absorption at 240 nm; phenolic acids at 217, 242, and 326 nm; flavonoids at 255 and 355 nm; while saponins had no absorption. In electrospray ionization (ESI)‐TOF‐MS experiments, elimination of a glucose unit (162 Da), and successive losses of H2O, CH3OH and CO, were generally observed in iridoid glycosides; saponins were characterized by a series of identical aglycone ions; phenolic acids typically generated a base peak at [M–H–caffeoyl]− by loss of a caffeic acid unit (162 Da) and several marked quinic acid moiety ions; cleavage of the glycosidic bond (loss of 162 or 308 Da), subsequent losses of H2O, CO, RDA and C‐ring fragmentation were the most possible fragmentation pathways for flavonoids. By accurate mass measurements within 4 ppm error for each molecular ion and subsequent fragment ions, as well as the ‘full mass spectral’ information of TOF‐MS, a total of 41 compounds including 13 iridoid glycosides, 11 phenolic acids, 7 saponins, and 10 flavonoids were identified in a methanolic extract of FLJ. Copyright © 2009 John Wiley & Sons, Ltd.
Mechanical analysis of end‐to‐end silk‐sutured anastomosis for robot‐assisted surgery
Authors: Liu Ying , Wang Shuxin , Jack Hu S. , Qiu Wei 
Published: September 2009

AbstractBackgroundRobot‐assisted anastomosis holds great promise for the future. To secure surgery quality, some key process factors, such as the force arrangement of sutures, should be provided because of the lack of haptic feedback in robotics systemsMethodsA model of anastomosis is presented to establish the mechanical relationship between vessel and sutures. Stress distribution of the vessel loaded by the suture was then achieved through finite‐element simulations, based on the material property test results. Further, experiments were performed to validate the reliability of the FEM simulation of the anastomosis process.ResultsTo avoid blood osmosis, the allowable lower limit of the suture tension was 0.05 N. To keep the tissue free from injury, the allowable upper limit of tension on the suture was 0.4 N.ConclusionsThe study provided meaningful results for directing the robot‐assisted anastomosis procedure and design of the surgical tools. Copyright © 2009 John Wiley & Sons, Ltd.
Accuracy analysis of three‐dimensional bone surface models of the forearm constructed from multidetector computed tomography data
Authors: Oka Kunihiro , Murase Tsuyoshi , Moritomo Hisao , Goto Akira , Sugamoto Kazuomi , Yoshikawa Hideki 
Published: September 2009

AbstractBackgroundWe developed an original computer program that simulates upper limb reconstruction surgery using three‐dimensional (3D) bone models constructed from computed tomography (CT) data. However, the accuracy of a bone model has not been clarified, and radiation exposure from CT scanning posed a concern. The purpose of this study was to investigate the appropriate CT parameters required to reduce radiation exposure while maintaining the accuracy of 3D models of the forearm bones.MethodsTwelve dry forearm bones were used to investigate the accuracy of 3D bone models created from two different CT parameters. The accuracy was evaluated by measuring: (a) the discrepancy between the models constructed from low‐ and normal‐dose CT parameters; (b) the error between actual surface data derived by a contact‐type coordinate measuring machine and a 3D bone model; and (c) the difference between a 3D bone model constructed from a bare dry bone and a model constructed from the same bone embedded in a radio‐opaque soft tissue substitute. CT dose index (CTDI) and dose‐length product (DLP) were recorded to evaluate the radiation exposure.ResultsThe mean error between bone models constructed from two different CT parameters was 0.04 mm. CTDI and DLP for the normal‐radiation dose condition were 9.3 and 563 mGy/cm and those for the low‐radiation dose condition were 0.3 and 18 mGy/cm, respectively. The mean error between the bone models and scanning data from contact measurement was 0.45 mm. The mean error between a 3D model constructed from a dry bone and that constructed from the same bone embedded in a radio‐opaque soft tissue substitute was 0.06 mm.Conclusions3D bone models constructed from low‐radiation dose CT data demonstrated the same level of accuracy as those constructed from normal‐radiation dose data. The present simulation system can produce 3D bone models with one‐thirtieth of the normal radiation dose in the forearm. Copyright © 2009 John Wiley & Sons, Ltd.
Computer‐assisted needle positioning for liver tumour radiofrequency ablation (RFA)
Authors: Mundeleer Laurent , Wikler David , Leloup Thierry , Lucidi Valério , Donckier Vincent , Warzée Nadine 
Published: September 2009

AbstractBackgroundThe RFA procedures rely on a precise positioning of the radiofrequency electrode and the complete destruction of the tumour. This article presents new optimization techniques to improve such surgical procedures.MethodsA method to optimize the coverage of the tumour by successive RFA destructions and an in vitro procedure with simulated tumours have been developed.ResultsThe guidance system and optimization coverage have been tested on 3D simulation and by the surgeon in vitro on a heifer liver. In this context, the RFA electrode is optically tracked and guided.ConclusionsThe optimization method provides needle placements that ensure a complete theoretical ablation of the tumour, and the guidance system helps the surgeon to reach each position of destruction. Copyright © 2009 John Wiley & Sons, Ltd.
Nonlinear adaptive control of a model of an uncertain fermentation process
Authors: Dimitrova Neli , Krastanov Mikhail 
Published: September 2009

AbstractA nonlinear model of a methane fermentation is considered. Assuming that the model parameters are unknown but bounded, the global asymptotic stabilizability of the control system is studied and a nonlinear adaptive stabilizing feedback is proposed. The feedback law depends only on measurable variables. A numerical extremum seeking algorithm is designed for stabilizing the dynamic system toward the maximum outflow rate of biogas. Computer simulations are reported to illustrate the theoretical results. Copyright © 2009 John Wiley & Sons, Ltd.
Controllability and observability for time‐varying switched impulsive controlled systems
Authors: Zhao Shouwei , Sun Jitao 
Published: September 2009

AbstractThis paper is concerned with the controllability and observability for linear time‐varying switched impulsive systems. First, some new results about the variation of parameters for time‐varying switched impulsive systems are derived. Then less conservative sufficient conditions and necessary conditions for state controllability and observability of such systems are established. And for such system without impulsive control input, sufficient and necessary conditions for controllability and observability are derived. Furthermore, corresponding criteria applied to time‐varying impulsive systems are also discussed and examples are presented to show the effectiveness of the proposed results. Copyright © 2009 John Wiley & Sons, Ltd.
Robust outdoor visual localization using a three‐dimensional‐edge map
Authors: Nuske Stephen , Roberts Jonathan , Wyeth Gordon 
Published: September 2009

AbstractVisual localization systems that are practical for autonomous vehicles in outdoor industrial applications must perform reliably in a wide range of conditions. Changing outdoor conditions cause difficulty by drastically altering the information available in the camera images. To confront the problem, we have developed a visual localization system that uses a surveyed three‐dimensional (3D)‐edge map of permanent structures in the environment. The map has the invariant properties necessary to achieve long‐term robust operation. Previous 3D‐edge map localization systems usually maintain a single pose hypothesis, making it difficult to initialize without an accurate prior pose estimate and also making them susceptible to misalignment with unmapped edges detected in the camera image. A multihypothesis particle filter is employed here to perform the initialization procedure with significant uncertainty in the vehicle's initial pose. A novel observation function for the particle filter is developed and evaluated against two existing functions. The new function is shown to further improve the abilities of the particle filter to converge given a very coarse estimate of the vehicle's initial pose. An intelligent exposure control algorithm is also developed that improves the quality of the pertinent information in the image. Results gathered over an entire sunny day and also during rainy weather illustrate that the localization system can operate in a wide range of outdoor conditions. The conclusion is that an invariant map, a robust multihypothesis localization algorithm, and an intelligent exposure control algorithm all combine to enable reliable visual localization through challenging outdoor conditions. © 2009 Wiley Periodicals, Inc.
Performance analysis of secure on‐demand services for wireless vehicular networks
Authors: Coronado Etienne S. , Cherkaoui Soumaya 
Published: September 2009

AbstractWireless vehicular communications pose significant challenges for the deployment of next generation roadside services. Some important issues that must be tackled are security, billing, and reliability while guarantying a scalable service delivery. This paper addresses the assignation of secure service session parameters upon the reception of on‐demand service requests by an incumbent services district domain and studies and analyses the performance of the underlying mechanisms. Three types of service request protocols are introduced in our work defined as single‐hop (SHI‐RQ), extended connectivity (EC‐RQ), and multi‐hop (MHI‐RQ) service requests. A detailed analytical model and cost study for the access protocols are presented. Our analysis study covers the estimation of total cost in terms of latency for each access protocol with different mobility characteristics and vehicle densities within the service coverage area and across different serving district domains. The analytical results are consistent with the experimental one and show that the access protocols cost in terms latency remains acceptable for a realistic number of serviced vehicles even at high speeds. Copyright © 2009 John Wiley & Sons, Ltd.
RFIDGuard: a lightweight privacy and authentication protocol for passive RFID tags
Authors: Liu Alex X. , Bailey LeRoy A. , Krishnamurthy Adithya H. 
Published: September 2009

AbstractRadio frequency identification (RFID) tags are cheap, simple devices that can store unique identification information and perform simple computation to keep better inventory of packages. Because of this, they are intended to replace the barcodes for supply chain management in the near future. However, unlike barcodes, these tags have a longer range in which they are allowed to be scanned, subjecting them to unauthorized scanning by malicious readers and to various attacks, including cloning. Therefore, a security protocol for RFID tags is needed to ensure privacy and authentication between each tag and their reader. In order to accomplish this, in this paper, we propose RFIDGuard, a lightweight privacy and authentication protocol for passive RFID tags. This protocol requires little computation and achieves both privacy and authentication simultaneously. The lightweight and secure nature of our RFIDGuard protocol make it particularly suitable for supply chain management. Adaptation of our protocol can be used for other applications as well. Copyright © 2009 John Wiley & Sons, Ltd.
Electric‐Field‐Assisted Growth of Functionalized Poly(3,4‐ethylenedioxythiophene) Nanowires for Label‐Free Protein Detection
Authors: Xie Hong , Luo Shyh‐Chyang , Yu Hsiao‐hua 
Published: September 2009

AbstractThe construction of functionalized poly(3,4‐ethylenedioxythiophene) (PEDOT) nanowire devices for label‐free protein detection is reported. Direct growth/assembly of PEDOT nanowires with carboxylic acid side‐chain functional groups (poly(EDOT‐COOH)) across the electrode junction is achieved by using an electric‐field‐assisted method. These functionalized PEDOT nanowire devices show typical depletion‐mode p‐type field‐effect transistor (FET) properties. Upon conjugation with a protein‐binding aptamer, the PEDOT nanowire FET devices are used for label‐free electronic detection of a target protein of interest. The binding of a positively charged protein causes a substantial decrease in current flow, attributed to the specific interaction between target protein molecules and aptamer‐conjugated polymer chains.
A profile‐based approach for maintaining software architecture: an industrial experience report
Authors: Riva Claudio , Selonen Petri , Systä Tarja , Xu Jianli 
Published: September 2009

AbstractThis paper presents our experiences in building a UML‐based approach for maintaining software products of a large‐scale industrial product family. It enables software architects to define rules and constraints for a product family architecture to be enforced on individual product architectures. The target system of our study was the Nokia ISA platform for a mobile phone product family, a complex software system comprising thousands of components and several million lines of code. We outline our approach and the accompanying tools, and report our experiences and lessons learned in assessing the architectural integrity of 10 ISA platform releases and the associated products. Copyright © 2009 John Wiley & Sons, Ltd.
Developmental Regulation of Human Embryonic Stem Cell-Derived Neurons by Calcium Entry via Transient Receptor Potential Channels
Authors: Weick Jason P. , Austin Johnson M. , Zhang Su-Chun 
Published: September 2009

Abstract
Spontaneous calcium (Ca2+) transients in the developing nervous system can affect proliferation, migration, neuronal subtype specification, and neurite outgrowth. Here, we show that telencephalic human neuroepithelia (hNE) and postmitotic neurons (PMNs) generated from embryonic stem cells display robust Ca2+ transients. Unlike previous reports in animal models, transients occurred by a Gd3+/La3+-sensitive, but thapsigargin- and Cd2+-insensitive, mechanism, strongly suggestive of a role for transient receptor potential (Trp) channels. Furthermore, Ca2+ transients in PMNs exhibited an additional sensitivity to the canonical Trp (TrpC) antagonist SKF96365 and shRNA-mediated knockdown of the TrpC1 subunit. Functionally, inhibition of Ca2+ transients in dividing hNE cells led to a significant reduction in proliferation, whereas either pharmacological inhibition or shRNA-mediated knockdown of the TrpC1 and TrpC4 subunits significantly reduced neurite extension in PMNs. Primary neurons cultured from fetal human cortex displayed nearly identical Ca2+ transients and pharmacological sensitivities to Trp channel antagonists. Together these data suggest that Trp channels present a novel mechanism for controlling Ca2+ transients in human neurons and may offer a target for regulating proliferation and neurite outgrowth when engineering cells for therapeutic transplantation.
Disclosure of potential conflicts of interest is found at the end of this article.
Performance and levels of contextualization in a selection of OECD countries in PISA 2006
Authors: Nentwig Peter , Roennebeck Silke , Schoeps Katrin , Rumann Stefan , Carstensen Claus 
Published: September 2009

AbstractCorrect responses to the unitized items of PISA 2006 rely to differing extents on the contextual stimulus supplied. This difference is referred to in this study as the degree of contextualization. A selection of science items from PISA 2006 has been assigned to two categories, not by competencies as in the framework for the PISA survey, but by the degree to which the item requires the ability to extract and apply information from the contextual stimulus provided. The article explores how students in Germany and in other selected OECD countries perform in solving these two types of items. The results show that German students' performance is satisfactory when solving items which require knowledge to be recalled and applied but that they are also quite capable of extracting and using information from the item stimuli. Somewhat different distributions are observed in other selected OECD countries. © 2009 Wiley Periodicals, Inc. J Res Sci Teach 46: 897–908, 2009
Element‐selective three‐dimensional imaging of microparticles with a confocal micro‐PIXE arrangement
Authors: Žitnik M. , Pelicon P. , Bučar K. , Grlj N. , Karydas A. G. , Sokaras D. , Schütz R. , Kanngießer B. 
Published: September 2009

AbstractA detailed report about the confocal experiment and the corresponding data analysis is presented to determine local atomic concentrations in a thick sample with a micrometer resolution. X‐ray emission from a quartz substrate, loaded by aerosol particles, was induced by a scanning proton microbeam and observed by an Si(Li) spectrometer whose field of view was narrowed by a polycapillary lens. A series of X‐ray images were recorded at different positions of the sample along the microbeam axis when the particles were driven through the sensitive microvolume. The concentrations reconstructed in three dimensions were used to extract penetration profiles of the strongest X‐ray emitters (Fe, Ca, S) in an aerosol sample together with the surface profile of the matrix (Si). The results show exponentially dumped depth profiles with characteristic length depending on particle size. Copyright © 2009 John Wiley & Sons, Ltd.