bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrospray ionization mass spectrometric fragmentation of hydroquinone derivatives
Authors: Almodóvar Iriux , Ramírez‐Rodríguez Oney , Barriga Andrés , Rezende Marcos Caroli , Araya‐Maturana Ramiro 
Published: December 2010

AbstractThe fragmentation patterns of nine di‐, tri‐ and tetracyclic hydroquinones with potential antitumor activity were rationalized by invoking competing mechanisms that included sterically accelerated homolytic cleavage, Meerwein‐type rearrangements and dehydrations through elimination or intramolecular nucleophilic substitution. Copyright © 2010 John Wiley & Sons, Ltd.
Hydrophilic interaction liquid chromatography/tandem mass spectrometry for the analysis of diallyldimethylammonium chloride in water
Authors: Esparza X. , Moyano E. , Ventura F. , Galceran M. T. 
Published: December 2010

AbstractWe report a selective, sensitive and fast liquid chromatography/tandem mass spectrometry (LC/MS/MS) method for the determination of diallyldimethylammonium chloride (DADMAC) in water. Hydrophilic interaction liquid chromatography (HILIC) was used to avoid ion‐pairing reagents, which are generally employed to retain cationic compounds. The complementary information obtained in a triple quadrupole mass spectrometer and in an ion trap Orbitrap has been used to study the fragmentation of the DADMAC cation [M]+ and for the correct assignment of the products ions. The HILIC/MS/MS method developed, using electrospray ionization in positive ion mode and selected reaction monitoring (SRM) acquisition mode, led to a reliable determination and confirmation of the DADMAC cation in water samples down to 50 ng L−1. The low detection limit achieved, in combination with the absence of matrix effects, allowed the direct analysis of samples without any pretreatment, preconcentration or clean‐up step. DADMAC was determined in samples collected in a drinking water treatment plant (DWTP) in Barcelona (Spain) and it was found in the influent at the µg L−1 level. Copyright © 2010 John Wiley & Sons, Ltd.
CO and methanol adsorption on (2 × 1)Pt(110) and ion‐eroded Pt(111) model catalysts
Authors: Matolínová Iva , Johánek Viktor , Mysliveček Josef , Prince Kevin C. , Skála Tomáš , Škoda Michal , Tsud Nataliya , Vorokhta Mykhailo , Matolín Vladimír 
Published: December 2010

AbstractMethanol adsorption on ion‐sputtered Pt(111) surface exhibiting high concentration of vacancy islands and on (2 × 1)Pt(110) single crystal were investigated by means of photoelectron spectroscopy (PES) and thermal desorption spectroscopy. The measurements showed that methanol adsorbed at low temperature on sputtered Pt(111) and on (2 × 1)Pt(110) surfaces decomposed upon heating. The PES data of methanol adsorption were compared to the data of CO adsorbed on the same Pt single crystal surfaces. In the case of the sputtered Pt(111) surface, the dehydrogenation of HxCO intermediates is followed by the CO bond breakage. On the (2 × 1)Pt(110) surface, carbon monoxide, as product of methanol decomposition, desorbed molecularly without appearance of any traces of atomic carbon. By comparing both platinum surfaces we conclude that methanol decomposition occurs at higher temperature on sputtered Pt(111) than on (2 × 1)Pt(110). Copyright © 2010 John Wiley & Sons, Ltd.
Summary of ISO/TC 201 Standard: ISO 29081: 2010, surface chemical analysis—Auger electron spectroscopy—reporting of methods used for charge control and charge correction
Authors: Baer D. R. 
Published: December 2010

AbstractThis international standard specifies the minimum amount of information required for describing the methods of charge control and charge correction in measurements of Auger electron transitions from insulating specimens by electron‐stimulated AES to be reported with the analytical results. Information is provided in an Annex on methods that have been found useful for charge control prior to or during AES analysis. The Annex also includes a summary table of methods or approaches, ordered by simplicity of approach. A similar international standard has been published for XPS (ISO 19318: 2003(E), Surface chemical analysis—XPS—reporting of methods used for charge control and charge correction. Copyright © 2010 John Wiley & Sons, Ltd.
Changes in the surface structure of Pd/Ta2O5 by oxygen and CO studied using X‐ray Photoelectron Spectroscopy (XPS)
Authors: Seo Hyun Ook , Lee Jaeyoung , Kim Kwang‐Dae , Luo Yuan , Dey Nilay Kumar , Kim Young Dok 
Published: December 2010

AbstractBehaviors of Pd structures with different thicknesses supported by Ta2O5/Ta in the reaction with oxygen and CO were studied by XPS and SEM. For the samples with a Pd thickness of 3 nm, a new low‐binding‐energy component appeared in the Pd 3d level upon O2 exposure at ∼200 °C and was reduced in intensity after a subsequent CO exposure at 150 and 200 °C. The change in the Ta 4f state could also be found upon oxygen and CO exposure, indicating that both Pd and the Ta‐oxide substrate participate in the chemical reactions. For the sample with a higher Pd thickness, a positive shift in the Pd 3d level due to the oxidation of Pd was observed after exposure to O2 at a higher temperature (280 °C). A subsequent CO exposure at ∼150 °C could not reduce Pd‐oxide layers, as confirmed by the unchanged Pd 3d spectra after CO treatment, i.e. Pd‐oxide was not reactive for CO oxidation. Copyright © 2010 John Wiley & Sons, Ltd.
Exploring the benefits of adaptive sequential designs in time‐to‐event endpoint settings
Authors: Emerson Sarah C. , Rudser Kyle D. , Emerson Scott S. 
Published: December 2010

AbstractSequential analysis is frequently employed to address ethical and financial issues in clinical trials. Sequential analysis may be performed using standard group sequential designs, or, more recently, with adaptive designs that use estimates of treatment effect to modify the maximal statistical information to be collected. In the general setting in which statistical information and clinical trial costs are functions of the number of subjects used, it has yet to be established whether there is any major efficiency advantage to adaptive designs over traditional group sequential designs. In survival analysis, however, statistical information (and hence efficiency) is most closely related to the observed number of events, while trial costs still depend on the number of patients accrued. As the number of subjects may dominate the cost of a trial, an adaptive design that specifies a reduced maximal possible sample size when an extreme treatment effect has been observed may allow early termination of accrual and therefore a more cost‐efficient trial. We investigate and compare the tradeoffs between efficiency (as measured by average number of observed events required), power, and cost (a function of the number of subjects accrued and length of observation) for standard group sequential methods and an adaptive design that allows for early termination of accrual. We find that when certain trial design parameters are constrained, an adaptive approach to terminating subject accrual may improve upon the cost efficiency of a group sequential clinical trial investigating time‐to‐event endpoints. However, when the spectrum of group sequential designs considered is broadened, the advantage of the adaptive designs is less clear. Copyright © 2010 John Wiley & Sons, Ltd.
Advanced Optical Imaging Reveals the Dependence of Particle Geometry on Interactions Between CdSe Quantum Dots and Immune Cells
Authors: Aaron Jesse S. , Greene Adrienne C. , Kotula Paul G. , Bachand George D. , Timlin Jerilyn A. 
Published: December 2010

AbstractThe biocompatibility and possible toxicological consequences of engineered nanomaterials, including quantum dots (QDs) due to their unique suitability for biomedical applications, remain intense areas of interest. We utilized advanced imaging approaches to characterize the interactions of CdSe QDs of various sizes and shapes with live immune cells. Particle diffusion and partitioning within the plasma membrane, cellular uptake kinetics, and sorting of particles into lysosomes were all independantly characterized. Using high‐speed total internal reflectance fluorescence (TIRF) microscopy, we show that QDs with an average aspect ratio of 2.0 (i.e., rod‐shaped) diffuse nearly an order of magnitude slower in the plasma membrane than more spherical particles with aspect ratios of 1.2 and 1.6, respectively. Moreover, more rod‐shaped QDs were shown to be internalized into the cell 2‐3 fold more slowly. Hyperspectral confocal fluorescence microscopy demonstrates that QDs tend to partition within the cell membrane into regions containing a single particle type. Furthermore, data examining QD sorting mechanisms indicate that endocytosis and lysosomal sorting increases with particle size. Together, these observations suggest that both size and aspect ratio of a nanoparticle are important characteristics that significantly impact interactions with the plasma membrane, uptake into the cell, and localization within intracellular vesicles. Thus, rather than simply characterizing nanoparticle uptake into cells, we show that utilization of advanced imaging approaches permits a more nuanced and complete examination of the multiple aspects of cell‐nanoparticle interactions that can ultimately aid understanding possible mechanisms of toxicity, resulting in safer nanomaterial designs.
Coloring, a versatile technique for implementing object‐oriented languages
Authors: Ducournau Roland 
Published: December 2010

AbstractLate binding and subtyping create run‐time overhead for object‐oriented languages. Dynamic typing and multiple inheritance create even more overhead. Static typing and single inheritance lead to two major invariants, of reference and position, that make the implementation as efficient as possible. Coloring is a technique that preserves these invariants for dynamic typing or multiple inheritance at minimal spatial cost. Coloring has been independently proposed for method invocation under the name ofselector coloring, for subtype tests under the name ofpack encoding, and for attribute access and object layout. This paper reviews a number of uses of coloring for optimizing object‐oriented programming, generalizes them, and specifies several variations, such as bidirectional andn‐directional coloring. Coloring is NP‐hard, hence compilers that use it depend on heuristics. The paper describes two families of heuristics and presents some experimental results which indicate that coloring is both efficient and tractable and that bidirectional coloring gives the best results. Copyright © 2010 John Wiley & Sons, Ltd.
Using meta‐modeling in design and implementation of component‐based systems: the SOFA case study
Authors: Hnětynka Petr , Plášil František 
Published: December 2010

AbstractTo allow efficient and user‐friendly development of a component‐based application, component systems have to provide a rather complex development infrastructure, including a tool for component composition, component repository, and a run‐time infrastructure. In this paper, we present and evaluate benefits of using meta‐modeling during the process of defining a component system and also during creation of the development and run‐time infrastructures. Most of the presented arguments are based on a broad practical experience with designing the component systems SOFA and SOFA 2; the former designed in a classical ad hoc ‘manual’ way, whereas the latter with the help of meta‐modeling. Copyright © 2010 John Wiley & Sons, Ltd.
A group‐oriented secure multiagent platform
Authors: Such Jose M. , Alberola Juan M. , Espinosa Agustin , Garcia‐Fornes Ana 
Published: December 2010

AbstractSecurity is becoming a major concern in multiagent systems, since an agent's incorrect or inappropriate behaviour may cause non‐desired effects, such as money and data loss. Some multiagent platforms (MAP) are now providing baseline security features, such as authentication, authorization, integrity and confidentiality. However, they fail to support other features related to the sociability skills of agents such as agent groups. What is more, none of the listed MAPs provide a mechanism for preserving the privacy of the users (regarding their identities) that run their agents on such MAPs. In this paper, we present the security infrastructure (SI) of the Magentix MAP, which supports agent groups and preserves user identity privacy. The SI is based on identities that are assigned to all the different entities found in Magentix (users, agents and agent groups). We also provide an evaluation of the SI describing an example application built on top of Magentix and a performance evaluation of it. Copyright © 2010 John Wiley & Sons, Ltd.
Mitochondrial Function Controls Proliferation and Early Differentiation Potential of Embryonic Stem Cells
Authors: Mandal Sudip , Lindgren Anne G. , Srivastava Anand S. , Clark Amander T. , Banerjee Utpal 
Published: December 2010

Abstract
Pluripotent stem cells hold significant promise in regenerative medicine due to their unlimited capacity for self-renewal and potential to differentiate into any cell type of the body. In this study, we demonstrate that proper mitochondrial function is essential for proliferation of undifferentiated ESCs. Attenuating mitochondrial function under self-renewing conditions makes these cells more glycolytic-dependent, and it is associated with an increase in the mRNA reserves of Nanog, Oct4, and Sox2. In contrast, attenuating mitochondrial function during the first 7 days of differentiation results in normal repression of Oct4, Nanog, and Sox2. However, differentiation potential is compromised as revealed by abnormal transcription of multiple Hox genes. Furthermore, under differentiating conditions in which mitochondrial function is attenuated, tumorigenic cells continue to persist. Our results, therefore establish the importance of normal mitochondrial function in ESC proliferation, regulating differentiation, and preventing the emergence of tumorigenic cells during the process of differentiation.
Combining trust with location information for routing in wireless sensor networks
Authors: Leligou H. C. , Trakadas P. , Maniatis S. , Karkazis P. , Zahariadis T. 
Published: December 2010

ABSTRACTAs the applications of wireless sensor networks proliferate, the efficiency in supporting large sensor networks and offering security guarantees becomes an important requirement in the design of the relevant networking protocols. Geographical routing has been proven to efficiently cope with large network dimensions while trust management schemes have been shown to assist in defending against routing attacks. Once trust information is available for all network nodes, the routing decisions can take it into account, i.e. routing can be based on both location and trust attributes. In this paper, we investigate different ways to incorporate trust in location‐based routing schemes and we propose a novel way of balancing trust and location information. Computer simulations show that the proposed routing rule exhibits excellent performance in terms of delivery ratio, latency time and path optimality. Copyright © 2010 John Wiley & Sons, Ltd.
On centralized schedulers for 802.11e WLANs distributionversusgrouping of resources allocation
Authors: Mur Daniel Camps , Pérez‐Costa Xavier , Marchenko Vladimir , Ribes Sebastià Sallent 
Published: December 2010

ABSTRACTWireless LAN is becoming a pervasive wireless access technology that can be found in almost any mobile device such as laptops, PDAs, portable game consoles and mobile phones. Each of these groups of devices have a different set of requirements according to their intended use and applications but most of them share two main requirements: QoS support to satisfy applications' demands and power saving functionality to achieve an operating time according to users' expectations. IEEE 802.11e defines two centralized solutions in order to address these problems: Hybrid Coordination Channel Access (HCCA) for QoS and Scheduled Automatic Power Save Delivery (S‐APSD) for power saving. The focus of our work in this paper is the analysis and evaluation of a proposed centralized scheduler that makes use of both aforementioned IEEE 802.11e QoS and power saving solutions. Our contributions are as follows: (i) Design and analytical modeling of a proposed centralized scheduler (DRA) that maximizes the minimum distance between the resource allocations with pseudo‐polynomial complexity, (ii) Extensive performance evaluation of the QoS and power saving benefits of theDistributionproposal (DRA) as compared to a genericGroupingone (GRA), and (iii) Evaluation of the complexity and scalability of the proposal to assess its feasibility in practice. Copyright © 2010 John Wiley & Sons, Ltd.
Power efficient scheduling over fading channel for cross‐layer optimization
Authors: Bai Xiaofeng , Shami Abdallah , Primak Serguei 
Published: December 2010

ABSTRACTWe consider the minimization of long‐term average power consumption for packet transmission between a mobile station and the base station over Nakagami‐m fading channel. Power consumption is minimized by intelligent transmission scheduling design, with the average queuing delay and joint packet loss across MAC and physical layers being confined below certain levels. The problem is formulated as an infinite horizon constrained Markov decision problem and solved by linear programming (LP) method. The primary intention of this paper is to provide a visible paradigm on using LP method to optimize the performance of mobile wireless communication systems. We elaborate the detailed mathematical solution with consistent simulation experiments and emphasize the effectiveness of adaptive transmission scheduling for cross‐layer QoS provisioning. Copyright © 2010 John Wiley & Sons, Ltd.
Adaptive paging schemes for group calls in mobile broadband cellular systems
Authors: Gállego José Ramón , Canales María , Hernández‐Solana Ángela , Valdovinos Antonio 
Published: December 2010

ABSTRACTIn this paper, we analyze the problem of efficient paging for group call searches under realistic mobility patterns. Taking as a basis a location update scheme, based on the definition of an adaptive macro‐location area, adapted to the mobility pattern of the terminals, we characterize the residence probabilities in each location area of a generic macro‐area. With this information, we propose and evaluate different sequential group paging strategies, also taking into account their computational cost. Results show the suitability of some of the proposals (semiadaptive and hybrid schemes) and its applicability to new packet‐based broadband cellular systems. Copyright © 2010 John Wiley & Sons, Ltd.
Interference mitigation in WSN by means of directional antennas and duty cycle control
Authors: Staniec Kamil , Debita Grzegorz 
Published: December 2010

ABSTRACTNetwork spanning algorithms, such as ZigBee‐native and Stojmenovič, constitute a crucial element in the wireless sensor network design, by determining its potential for reliability and fault‐tolerance. The interconnections between nodes have a great impact on the radio interference level present in such a network and may create a serious electromagnetic compatibility issue in some cases. It can be proved that the total interference incurred by a statistical node can be diminished in two ways: either by using directional antennas or by setting an upper limit on the duty cycle of each network node. Copyright © 2010 John Wiley & Sons, Ltd.
Extraction of airfoil data using PIV and pressure measurements
Authors: Yang Hua , Shen Wen Zhong , Sørensen Jens Nørkær , Zhu Wei Jun 
Published: December 2010

AbstractA newly developed technique for determining the angle of attack (AOA) on a rotating blade is used to extract AOAs and airfoil data from measurements obtained during the MEXICO (Model rotor EXperiments in COntrolled conditions) rotor experiment. Detailed surface pressure and Particle Image Velocimetry (PIV) flow fields at different rotor azimuth positions are examined for determining sectional airfoil data. The AOA is derived locally by determining the local circulation on the blade from pressure data and subtracting the induction of the bound circulation from the local velocity. The derived airfoil data are compared to 2D data from wind tunnel experiments and XFOIL computations. The comparison suggests that the rotor is subject to severe 3D effects originating from the geometry of the rotor, and explains why the Blade Element Momentum technique with 2D airfoil data over‐predicts the loading of the rotor. The extraction technique is verified by employing the derived airfoil characteristics as input to computations using the BEM technique and comparing the calculated axial and tangential forces to the measured data. The comparison also demonstrates that the used technique of determining the AOA is a reliable tool to extract airfoil data from experimental data. Copyright © 2010 John Wiley & Sons, Ltd.
Crystal Engineering with Oxo‐ and Cyanocarbon Anions: Synthesis and Structural Characterization of Triorganotin(IV) Pentacyanopropenides and Hexacyanoazapentadienides
Authors: Asrial   , Olbrich Falk , Spoida Marlies , Fischer Axel , Edelmann Frank T. 
Published: December 2010

AbstractThe first triorganotin(IV) pentacyanopropenides, [R3Sn(H2O)2][C3(CN)5] (R = Me (2), nBu (3), Ph (4) were prepared by treatment of Ag[C3(CN)5] (1) with equimolar amounts of R3SnCl in reagent grade THF. In a similar manner, dark red [R3Sn(H2O)2][N{C(CN)C(CN)2}2] (6) containing the hexacyanoazapentadienyl anion was prepared in 55 % yield. The molecular structure of [Ph3Sn(H2O)2][C3(CN)5] (4) was determined by X‐ray diffraction. The crystal structure consists of separated trigonal‐bipyramidal [Ph3Sn(H2O)2]+ cations and nearly planar [C3(CN)5]– anions which are linked through O–H···N hydrogen bonds to give a three‐dimensional network.
Regular [Tl6]6– Cluster in Cs4Tl2O Exhibiting Closed‐Shell Configuration and Energetic Stabilization due to Relativistic Spin–Orbit Coupling
Authors: Saltykov Vyacheslav , Nuss Jürgen , Wedig Ulrich , Jansen Martin 
Published: December 2010

AbstractCs4Tl2O was synthesized by reaction of the binary compounds CsTl and Cs2O at 573 K, followed by slow cooling to room temperature. According to single‐crystal X‐ray analysis, the title compound crystallizes in a new structure type (trigonal, space group R$\bar{3}$m (no. 166), a = 11.986(1), c = 20.370(2) Å, Z = 9). It consists of isolated [Tl6]6– octahedra, being regular with respect to the equality of all three main diagonals (4.546(5) Å), and of [Cs12O3]6+ triple octahedra extending along the c direction.The electronic structure of Cs4Tl2O was examined by relativistic density functional calculations including spin–orbit coupling and compared to the one of Rb10Tl6O2, which exhibits a highly distorted [Tl6]6– octahedra. In the latter case the closed‐shell electronic structure is the result of a Jahn–Teller distortion. In contrast, the regular one in Cs4Tl2O corresponds to a closed‐shell configuration, in accordance with diamagnetic properties, only if spin–orbit coupling is considered.