bluuebunny/crossref_metadata_2025_split huggingface dataset:
Needs assessment of family caregivers of cancer survivors: three cohorts comparison
Authors: Kim Youngmee , Kashy Deborah A. , Spillers Rachel L. , Evans Tekla V. 
Published: July 2009

AbstractPurpose/Background: Caregivers' quality of life (QOL) may be maximized when the caregivers' needs in the context of cancer care are met. Therefore, determining what needs are not being satisfied for family caregivers should be the first step in the development of programs designed to enhance caregivers' QOL.Method: The 28‐item Needs Assessment of Family Caregivers‐Cancer (NAFC‐C) scale was developed and validated with caregivers at three different survivorship phases: at 2 months (n=162), 2 years (n=896), and 5 years (n=608) post‐diagnosis.Results: The NAFC‐C helped to identify caregivers whose needs were less likely to be met, based on their age and ethnicity. Furthermore, the extent to which caregivers' psychosocial needs were not being met was a consistent and strong predictor of poor mental health across all phases of survivorship, beyond the effects of a host of demographic characteristics.Conclusion: Findings suggest that interventions designed to help caregivers manage their own emotional distress as well as the survivors' distress, find meaning in the cancer caregiving experience, and foster supportive familial relationship will benefit caregivers by improving their QOL, not only during the time of diagnosis and treatment but years after. Copyright © 2009 John Wiley & Sons, Ltd.
Challenging a paradigm: Theoretical calculations of the protonation state of the Cys25‐His159 catalytic diad in free papain
Authors: Shokhen Michael , Khazanov Netaly , Albeck Amnon 
Published: July 2009

AbstractA central mechanistic paradigm of cysteine proteases is that the His–Cys catalytic diad forms an ion‐pair NH(+)/S(−) already in the catalytically active free enzyme. Most molecular modeling studies of cysteine proteases refer to this paradigm as their starting point. Nevertheless, several recent kinetics and X‐ray crystallography studies of viral and bacterial cysteine proteases depart from the ion‐pair mechanism, suggesting general base catalysis. We challenge the postulate of the ion‐pair formation in free papain. Applying our QM/SCRF(VS) molecular modeling approach, we analyzed all protonation states of the catalytic diad in free papain and its SMe derivative, comparing the predicted and experimental pKa data. We conclude that the His–Cys catalytic diad in free papain is fully protonated, NH(+)/SH. The experimental pKa = 8.62 of His159 imidazole in free papain, obtained by NMR‐controlled titration and originally interpreted as the NH(+)/S(−) ⇌ N/S(−) $ {\rm NH}(+)/{\rm S}(-)\rightleftharpoons {\rm N/S}(-) $ equilibrium, is now assigned to the NH(+)/SH ⇌ N/SH$ {\rm NH}(+)/{\rm SH}\rightleftharpoons {\rm N/SH} $ equilibrium. Proteins 2009. © 2009 Wiley‐Liss, Inc.
A comparative analysis of the equilibrium dynamics of a designed protein inferred from NMR, X‐ray, and computations
Authors: Liu Lin , Koharudin Leonardus M. I. , Gronenborn Angela M. , Bahar Ivet 
Published: July 2009

AbstractA detailed analysis of high‐resolution structural data and computationally predicted dynamics was carried out for a designed sugar‐binding protein. The mean‐square deviations in the positions of residues derived from nuclear magnetic resonance (NMR) models and those inferred from X‐ray crystallographic B‐factors for two different crystal forms were compared with the predictions based on the Gaussian Network Model (GNM) and the results from molecular dynamics (MD) simulations. GNM systematically yielded a higher correlation than MD, with experimental data, suggesting that the lack of atomistic details in the coarse‐grained GNM is more than compensated for by the mathematically exact evaluation of fluctuations using the native contacts topology. Evidence is provided that particular loop motions are curtailed by intermolecular contacts in the crystal environment causing a discrepancy between theory and experiments. Interestingly, the information conveyed by X‐ray crystallography becomes more consistent with NMR models and computational predictions when ensembles of X‐ray models are considered. Less precise (broadly distributed) ensembles indeed appear to describe the accessible conformational space under native state conditions better than B‐factors. Our results highlight the importance of using multiple conformations obtained by alternative experimental methods, and analyzing results from both coarse‐grained models and atomic simulations, for accurate assessment of motions accessible to proteins under native state conditions. Proteins 2009. © 2009 Wiley‐Liss, Inc.
Electronic structure and magnetic properties of Fe3C with 2p and 3p impurities
Authors: Gutina O. Yu. , Medvedeva N. I. , Shein I. R. , Ivanovskii A. L. , Medvedeva J. E. 
Published: July 2009

AbstractAb initio calculations were performed to determine the effect of 2p and 3p impurities on the structural, electronic, and magnetic properties of cementite. We predict that phosphorus, sulfur, and all 2p impurities replace carbon, while aluminum and silicon substitute for iron. The magnetization and magnetic moments on iron atoms in the special and general positions only slightly change for impurities in the carbon sites, but they essentially decrease for impurities that substitute for iron (Al, Si). We find that boron and nitrogen (to a lesser degree) promote the stabilization of cementite and may be dissolved with the formation of ternary Fe3(C, B) and Fe3(C, N) cementites. Aluminum and especially silicon sharply suppress the formation of cementite.
Pressure‐induced phase transition and elastic properties of TiO2polymorphs
Authors: Ma X. G. , Liang P. , Miao L. , Bie S. W. , Zhang C. K. , Xu L. , Jiang J. J. 
Published: July 2009

AbstractA theoretical study was carried out by first‐principles calculations using plane‐wave pseudopotential method to investigate the crystal structures, relative stabilities, and elastic properties of seven known titanium dioxide (TiO2) polymorphs. Our calculated equilibrium structural parameters of TiO2polymorphs are in good agreement with the experimental results. Firstly, it is worth to note that from our energy‐minimized generalized gradient approximation (GGA) calculations, the four phases of TiO2– anatase, rutile, columbite, and baddeleyite – are seen to lie within a very close energy range (0.02 eV/atom) of each other, which implies easy phase transition between them. Secondly, on the basis of enthalpyversuspressure data obtained from our GGA calculations for high‐pressure forms, we demonstrate the phase transition pressure and the expected sequence of the phase transition of TiO2, which are in reasonable agreement with experimental observations. Finally, we calculate the elastic constants of all the TiO2polymorphs, and based on them, the bulk modulus, shear modulus, Young's modulus, and Poisson's ratio are estimated. The results show that cotunnite‐type TiO2is a potential low‐compressible material.
Band‐structure and optical‐transition parameters of wurtzite MgO, ZnO, and CdO from quasiparticle calculations
Authors: Schleife A. , Fuchs F. , Rödl C. , Furthmüller J. , Bechstedt F. 
Published: July 2009

AbstractWe use Hedin's GW framework to compute quasiparticle bands for group‐II monoxides in wurtzite (wz) structure. Modern hybrid density functional theory is applied to compute the starting electronic structure for the solution of the quasiparticle equation. We derive band parameters and effective masses for the three uppermost valence bands as well as the lowest conduction band including spin–orbit coupling. Optical transition matrix elements and exciton binding energies are also calculated. In addition to the prediction of parameters for wz‐MgO and wz‐CdO we discuss the chemical trend.
Damping of plasma waves in two‐dimensional electron systems due to contacts
Authors: Satou Akira , Ryzhii Victor , Mitin Vladimir , Vagidov Nizami 
Published: July 2009

AbstractWe report on the numerical study of plasma waves in two‐dimensional electron systems with contacts using the kinetic electron transport model. We simulate the time‐ and position‐dependence of plasma waves in the system by initially adding small perturbation of the electron concentration from the steady state. We demonstrate that in such a system the damping of plasma waves caused by “out of phase” electrons exiting the channel through the contacts occur. We find that the damping rate is proportional to the electron average velocity and inversely proportional to the channel length.
Symmetry determined medium range order (MRO) contributions to the first sharp diffraction peak (FSDP) in non‐crystalline oxide and chalcogenide glasses
Authors: Lucovsky Gerald , Phillips James C. 
Published: July 2009

AbstractThe first sharp diffraction peak (FSDP) in the structure factor, S(Q), obtained from X‐ray and neutron diffraction data, is a characteristic feature of oxide and chalcogenide glasses. This feature reflects intermediate, or medium range order (MRO), and is expressed in terms of two experimentally determined parameters, the position, Q1(Å−1), and the full‐width at half‐maximum (FWHM), ΔQ1(Å−1), of the FSDP peak. These parameters determine a correlation length R = 2π/Q1(Å−1) and a coherence length L = 2π/ΔQ1(Å−1) that result from symmetry‐determined contributions to the fundamental electronic structures of SiO2 and GeSe2. Narrow distributions of third neighbor SiO and GeSe pair correlation distances are forced by strongly correlated symmetries of Si and Ge d‐states connected through intervening O and Se atoms, as well as Se inter‐atom lone‐pair repulsions in GeSe2. The local bonding of threefold coordinated B‐atoms in B2O3 is planar rather than tetragonal and a similar O 2pπB 3dπ overlap is symmetry forbidden. Instead symmetry allowed O 2pπB 3pπ bonding interactions play the determining role in promoting second‐neighbor BO atom coupling through intervening O‐atoms, thereby extending the correlation length scale into the MRO regime.
Phase change materials: The importance of resonance bonding
Authors: Wuttig Matthias 
Published: July 2009

AbstractPhase change materials possess a property portfolio which is attractive for storage applications. At the same time the unique material properties provide interesting challenges for our understanding of solids. In this paper it will be demonstrated that many of the unique features of this material class are attributed to the bonding in the crystalline state. Resonance bonding is shown to be responsible for the high electronic polarizabilities in the crystalline state which enable a pronounced change of optical properties upon crystallization. Since resonance bonding can only develop in a very small number of solids under well‐defined conditions a map can be constructed which helps in locating phase change materials.
Effect of alloy disorder on photoluminescence in HgCdTe
Authors: Ivanov‐Omskii V. I. , Bazhenov N. L. , Mynbaev K. D. 
Published: July 2009

AbstractHg1−xCdxTe samples with x = 0.38 and 0.57 fabricated by molecular beam epitaxy, both as‐grown and after annealing, were studied. Photoluminescence (PL) was measured in the temperature range 4.2 < T < 300 K. The PL peak energy was found to be less than that of the energy gap by a certain value δE that depended on temperature. This effect was attributed to recombination of excitons localized at composition non‐homogeneities. An analysis was carried out that provided a way for evaluation of a non‐homogeneity measure. The amplitude of the non‐homogeneities was shown to decrease by about 50% as a result of post‐growth annealing in a He atmosphere and Hg vapour.
Economic design of Xbar control charts with continuously variable sampling intervals
Authors: Carolan Christopher A. , Kros John F. , Said Said E. 
Published: July 2009

AbstractIn the context of economic design, a two‐stage model is proposed that utilizes continuously variable sampling intervals. Specifically, each successive sampling interval is determined by the extremity of the latest sample. Modeling the situation as a Markov chain, the hourly cost is developed for any arbitrary set of design parameters. This proposed approach is found to be more economically desirable, possessing a smaller average out‐of‐control production time, when compared with a standard two‐stage approach where the sampling interval alternates between two fixed values. Copyright © 2009 John Wiley & Sons, Ltd.
[80]Fullerene–amino acid interactions: Theoretical insights
Authors: De Leon Aned , Jalbout Abraham F. , Basiuk Vladimir A. 
Published: July 2009

AbstractThis work reports the interactions of a C80 fullerene species with the 20 naturally occurring amino acids. As a result of the analysis of multiple configurations, we have determined that the most stable C80 complexes form with thiol containing amino acids. The stabilities of the resulting complexes have been classified according to biochemical classifications that are used to develop trends among the calculated data. The computed trends in the dissociation energies are related to the backbone structure of the corresponding amino acids. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
Endo[metallo] SWNT‐amino acid interactions: A theoretical study
Authors: Jalbout Abraham F. 
Published: July 2009

AbstractWe propose that an atom of calcium (Ca) which is an alkaline earth metal on encapsulation inside of a metallic armchair (5,5) (SWNT) species can have stronger amino acid interactions. From our calculations of various physical parameters we depict several configurations in which such an endo[metallo] SWNT can be modified by an internally placed Ca atom. Density functional theory (DFT) calculations reveal that the most favorable interactions of the SWNT system is with tryptophan, tyrosine, and phenylalanine that can be directly correlated to the backbone geometry of the amino acid species. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
A general method to obtain Sturmian functions for continuum and bound state problems with Coulomb interactions
Authors: Frapiccini A. L. , Randazzo J. M. , Gasaneo G. , Colavecchia F. D. 
Published: July 2009

AbstractIn this article, we investigate discretization schemes to represent Sturmian functions for both positive and negative energies in the presence of a long range Coulomb potential. We explore two methods to obtain Sturmian functions for positive energy. The first one involves the expansion of the radial wave function in a L2 finite basis set, whereas the second one introduces the discretization of the radial coordinate domain of the Hamiltonian or, alternatively, the Green function. We apply them to find the bound states and scattering phase shift for ${\cal N}$‐electron atoms close to the critical charge. Both methods are able to describe bound states near threshold, as well as continuum states with very good convergence properties. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
Adsorption and dissociation of carbon trioxide on Ag(100)
Authors: Soo Tsz‐Yan , Qin Changyong 
Published: July 2009

AbstractUsing density functional theory methods, we have studied carbon trioxide, its adsorption and dissociation on Ag(100). In the gas phase, two isomers are found, D3h and C2v, with the latter of 2.0 kcal mol−1 lower in energy at the PW91PW91/6−31G(d) level. For CO3 on Ag(100), the calculated adsorption energy is 91.2 and 89.1 kcal mol−1 for the bi‐coord perpendicular and tri‐coord parallel structures, respectively. Upon the adsorption, 0.50 ∼ 0.56 electron is transferred from silver to CO3, indicative of significant ionic characters of the adsorbate‐surface bonding. In addition, the geometry of CO3 is largely changed by its strong interaction with silver. For CO3(ad) → O(ad) + CO2(gas), the energy barrier is calculated to be 19.8 kcal mol−1 through the bi‐coord path. The process is endothermic with an enthalpy change of +17.3 ∼ +26.7 kcal mol−1 and the weakly chemisorbed CO2 is identified as an intermediate on the potential energy surface. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
Correlating data from multiple surface‐specific techniques using multivariate methods: examples and considerations
Authors: Lloyd K.G. , Walls D.J. , Wyre J.P. 
Published: July 2009

AbstractThis paper presents examples of spectral and mapping data correlation among different techniques using multivariate analytical methods. Specifically, ToF‐SIMS, ATR‐IR, and XPS Valence Band spectroscopic data acquired from a three‐component polymer blend are correlated using PLS (Partial Least Squares) analysis to show the combined response to compositional changes. Raman and secondary ion mapping data from a fluorocarbon–silicone polymer blend are correlated using MCR (Multivariate Curve Resolution) to try to associate changes in crystallinity with secondary ion patterns. Finally, XPS and ToF‐SIMS mapping data are correlated using MCR to show the advantages of combining data from a higher lateral resolution technique with data from a lower lateral resolution technique. Copyright © 2009 John Wiley & Sons, Ltd.
Design and Characterization of Rotational Multicomponent Catalytic Nanomotors
Authors: Gibbs J. G. , Zhao Y.‐P. 
Published: July 2009

AbstractMulticomponent rotational nanomotors consisting of Pt‐coated TiO2 nanoarms grown upon ≈2.01‐µm‐diameter silica microbeads designed by dynamic shadowing growth are presented. When exposed to H2O2, the structures rotate about an axis through the center of the microbead and perpendicular to the TiO2 nanoarm at a rate of 0.15 Hz per % H2O2 concentration. The rotational frequency increases parabolically when the surface tension of the solution is altered by the addition of sodium dodecyl sulphate; both relationships are explainable by a nanobubble‐ejection model.
Ultrastructural analysis of local collaterals of rat ventral tegmental area neurons: GABA phenotype and synapses onto dopamine and GABA cells
Authors: Omelchenko Natalia , Sesack Susan R. 
Published: July 2009

AbstractLocal synapses formed by nondopamine cells within the ventral tegmental area (VTA) are thought to provide an important regulatory influence on the activity patterns of dopamine (DA) neurons. However, ultrastructural confirmation of intra‐areal synapses formed by VTA neurons is lacking, and the synaptic targets of these connections have not been examined. We performed discrete injections of the specific anterograde tracer Phaseolus vulgaris leucoagglutinin (PHAL) and used electron microscopy to visualize immunoperoxidase labeling within the local collaterals of VTA cells. The phenotype of target neurons was determined by immunogold‐silver labeling for GABA or for tyrosine hydroxylase within DA neurons. Within or immediately adjacent to the VTA injection sites, PHAL was incorporated into the soma and dendrites of both GABA and DA cells. Tracer was also detected within myelinated and unmyelinated axons as well as axon terminals. Some labeled terminals formed identifiable synapses, the majority of which (78%) had symmetric morphology (presumably inhibitory). Both DA and GABA dendrites were contacted by these intrinsic axons. Postembedding immunogold labeling verified that local axon collaterals arose mainly from GABA cells (DA neurons are not known to issue recurrent collaterals). Nevertheless, a few synapses with asymmetric morphology (presumably excitatory) were also noted; whether these derive from local glutamate neurons requires further investigation. Hence, our data provide ultrastructural support for the long standing assumption that GABA VTA neurons synapse locally onto DA cells. The findings also suggest the presence of disinhibitory and possibly excitatory circuitry intrinsic to the VTA. Synapse 63:895–906, 2009. © 2009 Wiley‐Liss, Inc.
Comparison of fundal height measurement and sonographically measured fetal abdominal circumference in the prediction of high and low birth weight at term
Authors: Kayem G. , Grangé G. , Bréart G. , Goffinet F. 
Published: July 2009

AbstractObjectivesTo compare the diagnostic value of fundal height and sonographically measured fetal abdominal circumference in the prediction of high and low birth weight in routine practice between 37 and 41 weeks' gestation.MethodsData were obtained from a multicenter study of 19 415 women in France and Belgium. In this study we included 7138 low‐risk women from that population who underwent fundal height measurements no more than 8 days before delivery (Population A). We also included another 1689 women with both fundal height measurements and fetal ultrasound measurements obtained no more than 8 days before delivery (Population B). Population A was used to calculate the parameters of equations for estimating fetal weight according to fundal height alone (EFWFH) or fundal height in combination with other clinical indicators (EFWFH+). The ultrasound fetal weight estimation was based on fetal abdominal circumference (EFWAC) using Campbell and Wilkins' equation. The correlation between the estimated fetal weight calculated using each of the formulae and the birth weight was then evaluated in Population B, and the diagnostic value of each of the methods for predicting birth weight ≤2500 g or ≥4000 g was also compared.ResultsEFWAC was better correlated with birth weight than was either EFWFH or EFWFH+. With specificity set at 95%, the sensitivity of EFWAC in screening for neonates weighing ≤2500 g was significantly higher than that of EFWFH (50.7% vs. 41.2%, P < 0.05) or EFWFH+ (50.7% vs. 40.4%, P < 0.05). Similarly, its sensitivity for predicting a birth weight of ≥4000 g was significantly higher than that of EFWFH (54.0% vs. 37.1%, P < 0.05) or EFWFH+ (54.0% vs. 45.1%, P < 0.05).ConclusionsSonographic measurement of fetal abdominal circumference predicts high and low birth weight better than does clinical examination based on fundal height in routine practice between 37 and 41 weeks' gestation. Copyright © 2009 ISUOG. Published by John Wiley & Sons, Ltd.
A formalization of geometric constraint systems and their decomposition
Authors: Mathis Pascal , Thierry Simon E. B. 
Published: July 2009

Abstract

For more than a decade, the trend in geometric constraint systems solving has been to use a geometric decomposition/recombination approach. These methods are generally grounded on the invariance of systems under rigid motions. In order to decompose further, other invariance groups (e.g., scalings) have recently been considered. Geometric decomposition is grounded on the possibility to replace a solved subsystem with a smaller system called
boundary
. This article shows the central property that justifies decomposition, without assuming specific types of constraints or invariance groups. The exact nature of the boundary system is given. This formalization brings out the elements of a general and modular implementation.
Experience with the treatment of argininosuccinic aciduria during pregnancy
Authors: Reid L. , Perreault É. , Lafrance G. , Clarke J. T. R. 
Published: July 2009

SummaryWe present the details of the management and the outcome of a pregnancy of a woman affected with argininosuccinic aciduria. Management with a closely monitored, protein‐restricted diet, supplemented with L‐arginine, resulted in the birth of a healthy infant boy and an uneventful perinatal course for the mother.