bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hydrogen atom abstraction reactions of the sugar moiety of 2′‐deoxyguanosine with an OH radical: A quantum chemical study
Authors: Shukla P. K. , Kumar N. , Mishra P. C. 
Published: January 2010

AbstractMechanisms of hydrogen atom abstraction reactions of the sugar moiety of 2′‐deoxyguanosine with an OH radical were investigated using the B3LYP and BHandHLYP functionals of density functional theory and the second order Møller–Plesset Perturbation (MP2) theory in gas phase and aqueous media. The 6‐31+G* and AUG‐cc‐pVDZ basis sets were used. Gibbs free barrier energies and rate constants of the reactions in aqueous media suggest that an OH radical would abstract the hydrogen atoms of the sugar moiety of 2′‐deoxyguanosine in the following order of preference: H5′ ≈ H5″ > H3′ > H4′ > H1′ ≈ H2′ > H2″, the rate constant for H5′ abstraction being 103–105 times greater than that for H2″ at the different levels of theory. Relative stabilities of the different deoxyribose radicals are also discussed. The most and least favored hydrogen abstraction reactions found here are in agreement with experimental observation. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
An ONIOM and DFT study of water and ammonia adsorption on anatase TiO2 (001) cluster
Authors: Erdogan Rezan , Onal Isik 
Published: January 2010

AbstractDensity functional theory (DFT) calculations at ONIOM DFT B3LYP/ 6‐31G**‐MD/UFF level are employed to study molecular and dissociative water and ammonia adsorption on anatase TiO2 (001) surface represented by partially relaxed Ti20O35 ONIOM cluster. DFT calculations indicate that water molecule is dissociated on anatase TiO2 (001) surface by a nonactivated process with an exothermic relative energy difference of 58.12 kcal/mol. Dissociation of ammonia molecule on the same surface is energetically more favorable than molecular adsorption of ammonia (−37.17 kcal/mol vs. −23.28 kcal/mol). The vibration frequency values also are computed for the optimized geometries of adsorbed water and ammonia molecules on anatase TiO2 (001) surface. The computed adsorption energy and vibration frequency values are comparable with the values reported in the literature. Finally, several thermodynamical properties (ΔH°, ΔS°, and ΔG°) are calculated for temperatures corresponding to the experimental studies. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Combined experimental and computational modeling studies on 4‐[(2‐hydroxy‐3‐methylbenzylidene) amino]‐1,5‐dimethyl‐2‐phenyl‐1,2‐dihydro‐3H‐pyrazol‐3‐one
Authors: Tanak Hasan , Ağar Ayşen , Yavuz Metin 
Published: January 2010

AbstractThe Schiff base compound, 4‐[(2‐hydroxy‐3‐methylbenzylidene)amino]‐1,5‐dimethyl‐2‐phenyl‐1,2‐dihydro‐3H‐pyrazol‐3‐one, has been synthesized and characterized by IR, UV–vis, and X‐ray single‐crystal determination. Molecular geometry from X‐ray experiment of the title compound in the ground state have been compared using the density functional method (B3LYP) with 6‐31G(d,p) basis set. Calculated results show that density functional theory (DFT) can well reproduce the structure of the title compound. The energetic behavior of the title compound in solvent media has been examined using B3LYP method with the 6‐31G(d,p) basis set by applying the Onsager and the polarizable continuum model (PCM). The results obtained with these methods reveal that the PCM method provided more stable structure than Onsager's method. By using TD‐DFT method, electronic absorption spectra of the title compound have been predicted and a good agreement with the TD‐DFT method and the experimental one is determined. The predicted nonlinear optical properties of the title compound are much greater than ones of urea. In addition, DFT calculations of the title compound, molecular electrostatic potential and NBO analysis were performed at B3LYP/6‐31G(d,p) level of theory. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
A perturbation theory without energy corrections
Authors: Dhatt S. , Bhattacharyya K. 
Published: January 2010

AbstractWe employ logarithmic perturbation theory in a form that utilizes the force, instead of the potential, and yields equations for wavefunction‐correction terms without requiring any information of energy corrections at any stage. The knowledge of unperturbed eigenfunctions of other states is also unnecessary. The perturbed energy eigenvalue can be obtained as a series either by going back to the parent equation, or as an average value involving the perturbed state. The latter scheme applies to any other average property as well. Both ground and excited states of a few systems are chosen for demonstrative calculations. Influence of the nodal structure on the exponential function controlling spatial behavior of the probability density is discussed. Interrelations among specific correction terms are shown in the small‐ and large‐x regime; in the latter case, certain terms nicely sum up to yield the correct decay characteristics of the probability density as well. Relevance of the basic equation to an alternative, nonperturbative scheme of approximation is also outlined. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Human cytomegalovirus tropism for endothelial/epithelial cells: scientific background and clinical implications
Authors: Revello M. Grazia , Gerna Giuseppe 
Published: January 2010

AbstractHuman cytomegalovirus (HCMV) has been routinely isolated from and propagated in vitro in human embryonic lung fibroblast (HELF) cell cultures, while in vivo it is known to infect predominantly endothelial and epithelial cells. In recent years, genetic determinants of the HCMV tropism for endothelial/epithelial cells were identified in the UL131A/UL130/UL128 locus of HCMV genome of wild‐type strains. UL131A‐UL128 gene products form a complex with glycoprotein H (gH) and L (gL) resulting in a gH/gL/UL131A‐UL128 complex that is required for HCMV entry into endothelial/epithelial cells. In contrast, virus entry into fibroblasts has its genetic determinants in the complex gH/gL/gO (or gH/gL). During primary HCMV infection, the neutralising antibody response measured in endothelial cells (EC) is potent, occurs very early and is directed mostly against combinations of two or three gene products of the UL131A‐128 locus. On the contrary, neutralising antibodies measured in fibroblasts appear late, are relatively weak in potency and are directed against gH and gB. The T‐cell immune response to UL131A‐UL128 gene products remains to be investigated. Recently, a role has been proposed for neutralising antibody in conferring prevention/protection against HCMV infection/disease in pregnant women with primary HCMV infection. However, the level of cooperation between humoral immunity and the well‐established T‐cell protection remains to be defined. Copyright © 2010 John Wiley & Sons, Ltd.
Dispersibility of silane‐functionalized alumina nanoparticles in syndiotactic polypropylene
Authors: Truong Le Thuy , Larsen Åge , Holme Børge , Diplas Spyros , Hansen Finn Knut , Roots Jaan , Jørgensen Sissel 
Published: January 2010

AbstractThe dispersibility of silane‐functionalized alumina nanoparticles (NPs) in syndiotactic polypropylene (sPP) was investigated. The Al2O3 NP surface was modified with two different silane coupling agents, (3‐chloropropyl)triethoxysilane and (octyl)triethoxysilane, to create hydrocarbon groups, or their halogen derivatives, for the enhanced hydrophobic interaction with the sPP matrix. Transmission electron microscopy studies showed that the presence of hydrophobic groups improved the dispersibility of alumina NPs in the sPP matrix. A good dispersibility was found in both (3‐chloropropyl)triethoxysilane‐modified Al2O3/sPP nanocomposites and (octyl)triethoxysilane‐modified Al2O3/sPP nanocomposites. Copyright © 2010 John Wiley & Sons, Ltd.
Characterizing the surface acidity of bentonite by various methods
Authors: Bilgiç C. , Topaloglu Yazıcı D. , Vural N. 
Published: January 2010

AbstractSurface acidity of bentonite was investigated by using three methods. The first method was inverse gas chromatography; the acid‐base character of bentonite surface was estimated by the retention time with different nonpolar and polar probes at infinite dilution region. The adsorption specific free energy (ΔGSP), specific enthalpy (ΔHSP), and specific entropy (ΔSSP) of polar probes on bentonite were determined. By correlating ΔHSP with donor and acceptor numbers of the probes, the acidic (KA) and the basic (KD) parameters of the sample were calculated. The second method was recording the spectrums of pyridine by Fourier transform infrared spectroscopy (FTIR); the spectrum of pyridine bonded by Bronsted and Lewis acid sites was obtained. The last method was modified amine titration by using Hammett indicators. Copyright © 2010 John Wiley & Sons, Ltd.
The effects of shadow‐fading on QoS‐aware routing and admission control protocols designed for multi‐hop MANETs
Authors: Hanzo Lajos , Tafazolli Rahim 
Published: January 2010

AbstractProviding quality‐of‐service (QoS) assurances in a mobilead hocnetwork (MANET) is difficult due to node mobility, contention for channel access, a lack of centralised coordination, and the unreliable nature of the wireless channel. QoS‐aware routing (QAR) and admission control (AC) protocols comprise two of the most important components of a system attempting to provide QoS guarantees in the face of the above‐mentioned difficulties.This paper presents a comparative study, utilising a realistic shadow fading channel, of the performance of several state‐of‐the‐art amalgamated QAR‐AC protocols, which are designed for providing throughput guarantees to applications. The advantages and drawbacks of their particular features are highlighted. For an environment where link quality varies rapidly, the results of the study highlight the ineffectiveness of previously‐proposed methods of relying merely on the success of route discovery to perform AC, of relying on the exceeding of the MAC layer retransmission count for link failure detection, of existing congestion detection schemes and of careful re‐admission of data sessions rather than fast re‐routing after shadowing‐induced link failures. Based on the lessons learnt, design guidelines for future QAR and AC protocols operating in a mobile shadow‐fading‐afflicted environment are presented. Copyright © 2010 John Wiley & Sons, Ltd.
A pragmatic approach to area coverage in hybrid wireless sensor networks
Authors: Ahmed Nadeem , Kanhere Salil S. , Jha Sanjay 
Published: January 2010

AbstractSuccess of Wireless Sensor Networks (WSN) largely depends on whether the deployed network can provide desired area coverage with acceptable network lifetime. This paper seeks to address the problem of determining the current coverage achieved by the non‐deterministic deployment of static sensor nodes and subsequently enhancing the coverage using mobile sensors. We identify three key elements that are critical for ensuring effective area coverage in Hybrid WSN: (i) determining the boundary of the target region and evaluating the area coverage (ii) locating coverage holes and maneuvering mobile nodes to fill these voids, and (iii) maintaining the desired coverage over the entire operational lifetime of the network. We propose a comprehensive solution that addresses all of the aforementioned aspects of the area coverage, called MAPC (mobility assisted probabilistic coverage). MAPC is a distributed protocol that operates in three distinct phases. The first phase identifies the boundary nodes using the geometric right‐hand rule. Next, the static nodes calculate the area coverage and identify coverage holes using a novel probabilistic coverage algorithm (PCA). PCA incorporates realistic sensing coverage model for range‐based sensors. The second phase of MAPC is responsible for navigating the mobile nodes to plug the coverage holes. We propose a set of coverage and energy‐aware variants of the basic virtual force algorithm (VFA). Finally, the third phase addresses the problem of coverage loss due to faulty and energy depleted nodes. We formulate this problem as an Integer Linear Program (ILP) and propose practical heuristic solutions that achieve similar performance as that of the optimal ILP solution. A guiding principle in our design process has been to ensure that the MAPC can be readily implemented in real‐world applications. We implemented the boundary detection and PCA algorithm (i.e., Phase I) of the MAPC protocol on off‐the‐shelf sensor nodes and results show that the MAPC can successfully identify boundary nodes and accurately determine the area coverage in the presence of real radio irregularities observed during the experiments. Extensive simulations were carried out to evaluate the complete MAPC protocol and the results demonstrate that MAPC can enhance and maintain the area coverage, while reducing the total energy consumption by up to 70% as compared with the basic VFA. Copyright © 2010 John Wiley & Sons, Ltd.
Network infrastructure extension using 802.1D‐based wireless mesh networks
Authors: Campos Rui , Duarte Ricardo , Sousa Filipe , Ricardo Manuel , Ruela José 
Published: January 2010

AbstractUbiquitous Internet access is becoming a major requirement for end‐users due to the increasing number of services and applications supported over the Internet. Extending the coverage of current Wi‐Fi infrastructures installed in companies, universities and cities, has been considered a solution to help in fulfilling this requirement, namely when it comes to wireless and nomadic Internet access.This paper describes and analyses a new and simple solution, called Wi‐Fi network Infrastructure eXtension (WiFIX), aimed at extending current Wi‐Fi infrastructures. WiFIX is based on standard IEEE 802.1D bridges and a single‐message protocol that is able to self‐organize the network, and it only requires software changes in IEEE 802.11 access points (APs); no changes to IEEE 802.11 stations are needed. Overhead analysis and experimental results show both the higher efficiency of the solution compared to the IEEE 802.11s draft standard and its good performance as far as data throughput, delay and packet loss are concerned. Copyright © 2010 John Wiley & Sons, Ltd.
Peak‐to‐average power ratio reduction in space–time coded MIMO‐OFDM via preprocessing
Authors: Zhu Dalin , Natarajan Balasubramaniam , Dyer Justin S. 
Published: January 2010

AbstractIn this paper, we propose a trellis exploration algorithm based preprocessing strategy to lower the peak‐to‐average power ratio (PAPR) of precoded MIMO‐OFDM. We first illustrate the degradation in PAPR due to optimal linear precoding in MIMO‐OFDM systems. Then we propose two forms of multi‐layer precoding (MLP) schemes to reduce PAPR. In both schemes, the inner‐layer precoder is designed to optimize system capacity/BER performance. In the first MLP scheme (MLP‐I), a common outer‐layer polyphase precoding matrix is employed. In the second MLP scheme (MLP‐II), data stream corresponding to every transmit antenna is precoded with a different outer‐layer polyphase precoding matrix. Both outer‐layer precoders are custom designed using the trellis exploration algorithm by applying the aperiodic autocorrelation of OFDM data symbols as the metric to minimize. Simulation results indicate that both MLP schemes show superior PAPR performance over conventional MIMO‐OFDM with and without precoding. In addition, MLP better exploits frequency diversity resulting in BER performance gains in multi‐path environments. Copyright © 2010 John Wiley & Sons, Ltd.
Reducing computational complexity using transmitter correlation value‐assisted schedulers in multiuser MIMO uplink
Authors: Gong Peng , Cao Ning , Kim Duk Kyung 
Published: January 2010

AbstractIn this paper, a threshold bounded antenna selection scheduler (TBS) and a computational complexity bounded antenna selection scheduler (CCBS) are proposed to reduce computational complexity in multiple input multiple output (MIMO) uplink. In contrast to previous works, a spatially correlated MIMO channel model is considered and a transmitter correlation value (TCV) is newly introduced to assist the antenna selection in addition to the channel gain. For the TBS or CCBS, with predetermined threshold of TCV or ratio of successful antennas (RSAs), full searching (FS) and sub searching (SS) are applied more efficiently to user equipments (UEs) compared with previous schedulers. As a result, the number of candidate antennas in the scheduling set can be reduced, which translates into a lower computational complexity in terms of number of evaluated antenna combinations. Additionally, compared with the TBS, the peak computational complexity can be further reduced by the CCBS. Simulation results show that with proposed schedulers the computational complexity can be reduced by at least 50% with an acceptable compromise of capacity. Copyright © 2010 John Wiley & Sons, Ltd.
Are gobiid fish more susceptible to predation if parasitized byEustrongylides excisus? An answer from robbed snakes
Authors: Sloboda Michal , Mihalca Andrei Daniel , Falka Istvan , Petrželková Klára J. , Carlsson Martin , Ghira Ioan , Modrý David 
Published: January 2010

AbstractAspects of the predator–prey relationship between dice snake,Natrix tessellataand gobiid fish infected withEustrongylides excisuswere studied in Lake Sinoe, Romania. A population of snakes residing here shows a high prevalence of subcutaneous larvae of this nematode. The hypothesis of the altered motility in infected fish leading to increased depredation by snakes was tested by comparing gobiids collected from dice snakes with gobiids caught via electrofishing. Out of a total of seven identified gobiid species, three were used for analysis: syrman gobyNeogobius syrman, mushroom gobyNeogobius eurycephalus, and round gobyNeogobius melanostomus. No significant differences in prevalence and intensity ofE.excisusinfection were found between fish caught by snakes and those obtained by electrofishing. However, significantly higher abundance ofE.excisuslarvae in fish caught by snakes was reported. These findings suggest limited influence of the presence ofE.excisuslarvae in studied gobiids regarding their susceptibility to predation by dice snakes.
Competitive Binding of Off‐Flavor Compounds with Soy Protein and β‐Cyclodextrin in a Ternary System: A Model Study
Authors: Arora Akshay , Damodaran Srinivasan 
Published: January 2010

AbstractRemoval of soy protein (SP)‐bound 2‐nonanone by β‐cyclodextrin (βCD) was studied using an equilibrium dialysis technique. It was observed that in the presence of βCD, a significant (p < 0.05) amount of SP‐bound 2‐nonanone could be removed in a concentration‐dependent manner. Up to 94% of SP‐bound 2‐nonanone was stripped from SP when 6 mM βCD was present in the system. However, in thermodynamic terms, the net standard free energy change for transfer of 2‐nonanone from SP to βCD, i.e., , was essentially zero, implying that the apparent equilibrium binding constant for the formation of βCD–2‐nonanone complex was essentially same as that for the SP–2‐nonanone complex formation in the ternary system. This indicated that stripping‐off of 2‐nonanone from SP by βCD was driven by the mass action ratio. Based on these results, it is shown that βCD can be used effectively for removing SP‐bound off‐flavor carbonyl compounds.
Short-term monitoring of the Spanish government balance
Authors: Leal Teresa , Pedregal Diego J. , Pérez Javier J. 
Published: January 2010

AbstractWe construct multivariate, state-space mixed-frequencies models for the main components of the Spanish General Government sector made up of blocks for each one of its subsectors: Central Government, Social Security and aggregate of Regional and Local government sectors. Each block is modelled through its total revenue and expenditure categories, and encompasses a number of indicators, depending on data availability. The mixed-frequencies approach is particularly relevant for the case of Spain, given its institutional set-up and the specific data availability for the different subsectors. All in all, we provide models detailed enough in coverage, while at the same time manageable, to be used: (1) for real-time monitoring of fiscal policies with a focus on quarterly developments of the General Government sector, (2) for the monitoring of general government sub-sectors for which intra-annual data coverage is limited (Regional and Local governments), (3) to bridge (translate) into National Accounts available monthly information for the subsectors of the general government.
The age of metamorphism of sillimanite-bearing schists at the Kyakhtinskoe deposit (southwestern Transbaikalia)
Authors: Izbrodin I.A. , Ripp G.S. , Doroshkevich A.G. , Sergeev S.A. , Matukov D.I. , Posokhov V.F. 
Published: January 2010

Abstract
Results of U-Pb (SHRIMP II) and Rb-Sr dating of sillimanite schists in southwestern Transbaikalia are presented, which testify to high-temperature metamorphism in the Late Mesozoic. The metamorphism might have been related to the formation of metamorphic cores or tectonoplutonic activity accompanied by the formation of rift structures in Transbaikalia and Mongolia.
Cobalt behavior during natural and technogenic oxidative leaching of Co-containing pyrites (Letnee chalcopyrite deposit, Southern Urals)
Authors: Gaskova O.L. , Belogub E.V. , Makarov D.V. 
Published: January 2010

Abstract
Cobalt behavior during the oxidation of sulfide ores, unlike that during the oxidation of Co ores, is poorly known. Moreover, cobalt sulfates are rare in the world. Complex hydrous cobalt-containing and cobalt sulfates have been found in technogenic zones at the Letnee chalcopyrite deposit (Southern Urals). They have been identified at pit bottoms, in the ore stockpile, as well as directly on ore fragments and the evaporation barriers of underdump water puddles. The paper reports the first experimental data on the oxidative leaching of Co-containing sulfide ores in the laboratory. Also, parts of a thermodynamic model for Co behavior in oxidized zones are presented.
Experiments have revealed an increase in acidity up to pH = 4.14, along with transport of sulfate sulfur and metals into solution. This suggests acid mine drainage during the development of the Letnee deposit. The published stability diagrams for hydrous Cu, Mg, Zn, Co, and Ni sulfates were analyzed and compared with mineralogical finds in a technogenic oxidized zone. This made it possible to explain the precipitation sequence of minerals from solutions during their concentration by evaporation. As salts of these elements are highly soluble, significant contents of toxic metals will inevitably remain in equilibrium solution, necessitating additional waste-water treatment (for example, creating sorption geochemical barriers). Therefore, the paper describes regularities in Co behavior during its sorption on solid phases.
Notes on three earthquakes in Santiago de Cuba (14.10.1800, 18.09.1826, 07.07.1842)
Authors: Cotilla M.O. , Córdoba D. 
Published: January 2010

Abstract
Damage and parameters of the earthquakes of October 14, 1800, September 18, 1826, and July 7, 1842, in Santiago de Cuba, in southeastern Cuba, have been studied. A quantitative re-evaluation of the size of the events is not feasible due to a lack of data. Hence, we have reinterpreted existing data to establish likely intensities and determine the epicentral region of occurrence. Available data do not permit accurate depth determinations. Intensities estimated from contemporary documentary sources give maximum values of 8, 8–9 and 8 (MSK scale), respectively. These seismic shocks were located in the Southeastern Seismotectonic Province of Cuba, Plate Boundary Zone Caribbean—North Atmerican. The earthquakes are associated with the Oriente fault system.