bluuebunny/crossref_metadata_2025_split huggingface dataset:
Changes in the stress in the femoral head neck junction after osteochondroplasty for hip impingement: A finite element study
Authors: Alonso‐Rasgado Teresa , Jimenez‐Cruz David , Bailey Colin G. , Mandal Parthasarathi , Board Tim 
Published: June 2012

AbstractThe surgical treatment of femoroacetabular impingement (FAI) often involves femoral osteochondroplasty. One risk of this procedure is fracture of the femoral neck. We developed a finite element (FE) model to investigate the relationship between depth of resection and femoral neck stress. CT data were used to obtain the geometry of a typical cam‐type hip, and a 3D FE model was constructed to predict stress in the head–neck after resection surgery. The model accounted for the forces acting on the head and abductor muscular forces. Bone resection was performed virtually to incremental resection depths. The stresses were calculated for five resection depths and for five different activities (i) standing on one leg (static case); (ii) two‐to‐one‐to‐two leg standing; (iii) normal walking; (iv) walking down stairs; and (v) a knee bend. In general, both the average Von Mises stresses and the area of bone that yielded significantly increased at a resection depth of ≥10 mm. The knee bend and walking down stairs demonstrated the highest stresses. The FE model predicts that fracture is likely to occur in the resection area first following removal of a third (10 mm) or more of the diameter of the femoral neck. We suggest that when surgeons perform osteochondroplasty for hip impingement, the depth of resection should be limited to 10 mm. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1999–2006, 2012
Trimethylamine N‐oxide as a media supplement for cartilage tissue engineering
Authors: O'Connell Grace D. , Fong Jason V. , Dunleavy Neil , Joffe Avrum , Ateshian Gerard A. , Hung Clark T. 
Published: June 2012

AbstractSupplements added to the culture media (e.g., growth factors and dexamethasone) have been successful in improving mechanical and biochemical properties of engineered cartilage towards native values. Trimethylamine N‐oxide (TMAO), a natural osmolyte found in shark cartilage, is thought to induce protein folding, and counteracts the destabilizing effect of the high concentrations of urea stored by sharks. The objective of this study was to investigate the use of TMAO as a media supplement for promoting growth of functional engineered cartilage in culture. In the first study, TMAO was added to the culture media for the first 14 days in culture and concentrations of 0–200 mM were evaluated. In the second study, TMAO was supplemented to the culture media following chondroitinase ABC digestion, which has been previously shown to mediate an increased collagen content in engineered cartilage. A dose‐dependent response was observed with improved mechanical and biochemical properties for engineered constructs cultured with TMAO at concentrations of 5–100 mM. The Young's modulus of digested constructs cultured in TMAO was 2× greater than digested constructs cultured in the control medium and recovered to undigested control levels by day 42. In conclusion, these initial studies with TMAO as a media supplement show promise for improving the compressive mechanical properties, increasing extracellular matrix production, and increasing the recovery time following chABC digestion. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1898–1905, 2012
Depth‐Dependent Indentation Microhardness Studies of Different Polymer Nanocomposites
Authors: Bhandari Netra L. , Lach Ralf , Grellmann Wolfgang , Adhikari Rameshwar 
Published: June 2012

AbstractContinuous depth sensing indentation microhardness measurements were performed to investigate the effect of filler content and dimensionality on the mechanical behaviour of different polymer nanocomposites. In 1D filler reinforced nanocomposites (such as PP/MWCNT system), both the hardness and the indentation modulus were found to appreciably increase up to a filler weight fraction of 1.6 wt.‐%. Further addition of the filler changed the properties only insignificantly. In the nanocomposites with 2D filler (such as in PA6/LS) both the hardness and the indentation modulus increase notably with the addition of the filler and showed intense plasticity. In the investigated systems and composition range, the 3D filler (such as PP/OS2) showed no reinforcing effect at all. In was concluded that the 1D and 2D nanofillers play much more effective reinforcing role to improve the mechanical properties than the 3D fillers.
Transition Metal Salt Doping on Polypyrrole/MWCNT Composites for Supercapacitor Applications
Authors: Karthikeyan G. , Das C. K. 
Published: June 2012

AbstractPolypyrrole doped by Zn2+ ions was synthesized as nanocomposites with MWCNT by in‐situ oxidative polymerization and investigated as electrode material for supercapacitors. The uniform coating of polypyrrole on MWCNT was characterized by field emission scanning electron microscopy (FESEM) and high resolution transmission electron microscopy (HRTEM). The effect of Zn2+ ions were characterized by Fourier transform infrared (FTIR) spectroscopy. The electrochemical performances were investigated by cyclic voltammetry (CV), constant current charging/discharging cyclic test (CC) and electrochemical impedance spectroscopy (EIS) using a three‐electrode system. The doped polypyrrole composites show higher specific capacitance and better cyclic stability.
Influence of Crystallization Conditions on Relaxation Properties of Polymer Near‐Surface Layers
Authors: Lebedev D. V. , Ivankova E. M. , Nashchekin A. V. , Marikhin V. A. , Myasnikova L. P. , Radovanova E. I. 
Published: June 2012

AbstractRelaxation properties of polymer near‐surface layers were investigated with the help of thermoluminescent method using Nanoluminograph (PlasmaChem GMbH, Germany). The gel‐ and melt‐crystallized films from PE of different molecular weight were studied. The light sum of thermoluminescence in the temperature range of various relaxation transitions was compared. It is found that it is primarily controlled by the type of morphology forming during crystallization and the arrangement of the structural units on a surface. The glass transition temperature in near‐surface layers appeared to be lower that that in the bulk. Bulk glass transition temperature was determined by radiothermoluminescence, DMA and DSC techniques.
Synthesis and Electrochemical Characterization of Modified Graphene/Polypyrrole Nanocomposites
Authors: Sahoo Sumanta , Nayak G. C. , Das Chapal Kumar 
Published: June 2012

AbstractNanocomposites based on both modified/unmodified graphene and polypyrrole, were investigated as electrode materials for supercapacitor application. All the nanocomposites were prepared by in‐situ oxidative polymerization method using ammonium persulfate as oxidant. The amine functionalization of Graphene was confirmed by FTIR and X‐ray Photo Electron Spectroscopy (XPS). Field Emission Scanning Electron Microscopy (FESEM) and High Resolution Transmission Electron Microscopy (HRTEM) analysis were performed to study the morphology of the nanocomposites. The maximum capacitance value was found as 240 F/g for unmodified graphene based composite. Though the capacitance value was found to be lower for modified graphene based composite, the cyclic stability was found to be higher as compared to unmodified graphene/polypyrrole nanocomposite.
Activated Rubber Crumb in Waterborn Surface Coating
Authors: Suma K. K. , Jacob Sinto , Joseph Rani 
Published: June 2012

AbstractThis study investigates the properties of a matt finishing paint formulated using Vinyl acetate (VAc) ‐ Butyl acrylate (BuA) copolymer latex (water based resin system) and activated rubber crumb (matting agent). Vinyl acetate ‐ Butyl acrylate copolymer prepared by semicontinuous emulsion polymerization. The copolymer emulsion mixed with dispersion of rubber crumb to make the surface coating. Presence of rubber crumb may actively resist the attack of chemicals and climate conditions.
Weight variation before and after surgery in Parkinson's disease: A noradrenergic modulation?
Authors: Guimarães Joana , Moura Eduardo , Vieira‐Coelho Maria Augusta , Garrett Carolina 
Published: June 2012

AbstractChanges in the nutritional profile of patients with Parkinson's disease have been reported before and after deep brain stimulation surgery. The major determinants of the weight variation in Parkinson's disease are not yet understood, and the mechanism seems complex. Based on the influence of the sympathetic nervous system in metabolic syndrome obesity, the intent of the present review is to consider the role of noradrenergic modulation on weight variations in Parkinson's disease. In this review the authors raise the following hypothesis: weight variation in Parkinson's disease before and after deep brain stimulation of the subthalamic nucleus could be influenced by noradrenergic interaction between the locus coeruleus, subthalamic nucleus, and hypothalamic nucleus. © 2012 Movement Disorder Society
Bayesian multipoint velocity encoding for concurrent flow and turbulence mapping
Authors: Binter Christian , Knobloch Verena , Manka Robert , Sigfridsson Andreas , Kozerke Sebastian 
Published: June 2012

AbstractAn approach to efficiently measure three‐dimensional velocity vector fields and turbulent kinetic energy of blood flow is presented. Multipoint phase‐contrast imaging is used in combination with Bayesian analysis to map both mean and fluctuating velocities over a large dynamic range and for practically relevant signal‐to‐noise ratios. It is demonstrated that the approach permits significant spatiotemporal undersampling to allow for clinically acceptable scan times. Using numerical simulations and in vitro measurements in aortic valve phantoms, it is shown that for given scan time, Bayesian multipoint velocity encoding provides consistently lower errors of velocity and turbulent kinetic energy over a larger dynamic range relative to previous methods. In vitro, significant differences in both peak velocity and turbulent kinetic energy between the aortic CoreValve (150 cm/s, 293 J/m3) and the St. Jude Medical mechanical valve (120 cm/s, 149 J/m3) were found. Comparison of peak turbulent kinetic energy measured in a patient with aortic stenosis (950 J/m3) and in a patient with an implanted aortic CoreValve (540 J/m3) revealed considerable differences relative to the values detected in healthy subjects (149 ± 12 J/m3) indicating the potential of the method to provide a comprehensive hemodynamic assessment of valve performance in vivo. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.
The role of technology in gifted students' motivation
Authors: Housand Brian C. , Housand Angela M. 
Published: June 2012

AbstractAlthough technology by itself may not be motivating, a relationship seems to exist between the opportunities that technology presents and motivation for gifted students. When technology use aligns with authentic or “real‐world” applications, motivation can be enhanced. This article explores the overlap between factors that have historically been shown to increase motivation and the unique affordances of technology tools to meet the needs of gifted and talented students. Some examples of this overlap include skills related to control and autonomy (e.g., time management, project management, and decision making about choices provided), challenge (e.g., perseverance and patience through hard work, proposing a project and following it through to completion), collaboration and cooperation (e.g., teamwork, people skills, social skills, anger management, and communication with students at other schools), curiosity (e.g., finding resources online, finding the work interesting, and learning new things), and recognition (e.g., the opportunity to communicate beyond the school walls, a “real” product). © 2012 Wiley Periodicals, Inc.
Optical probes of chain packing structure and exciton dynamics in polythiophene films, composites, and nanostructures
Authors: Barnes Michael D. , Baghar Mina 
Published: June 2012

AbstractThis mini‐review on the photophysics of poly‐alkyl thiophenes (e.g., P3HT) and its blends with electron‐acceptor moeties such as fullerenes (e.g., PCBM) and carbon nanotubes focuses on highlights of recent literature on spectroscopic probes of exciton formation, diffusion, charge‐separation, and transport in these materials. The literature in this area is vast: more than 3000 papers have been published in on P3HT (and related materials) and applications to organic solar energy harvesting devices over the last 20 years. Thus, no single review can capture the breadth and depth of this research. Here, we attempt to highlight some of the exciting new research efforts aimed at understanding photophysical processes in organic photovoltaic materials. This mini‐review is organized as follows: First, a summary of the theoretical framework commonly used to describe fundamental physical processes of charge generation in organic (polymeric) semiconductor materials is presented. We then discuss recent exciting results on ultrafast spectroscopic probes of exciton dynamics in these materials. Finally, we present highlights of new research on polymer nanostructures (nanoparticles and nanofibers) and their exciting applications to organic photovoltaics. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012
Titanium oxide nanospheres: preparation, characterization, and wide‐spectral absorption
Authors: Wu Zhan , Zhang Zhi‐Kun , Guo Deng‐Zhu , Xing Ying‐Jie , Zhang Geng‐Min 
Published: June 2012

AbstractTitanium oxide (TiO2) nanospheres were synthesized by using cathodic‐plasma electrolysis method at low voltage of 70 V. The morphological, componential, and structural characterizations of the nanospheres were carried out in detail by using scanning electron microscope (SEM), transmission electron microscope (TEM), X‐ray photoelectron spectroscopy (XPS), and X‐ray diffraction (XRD). It is found the nanospheres mostly have diameters in the range of 20–200 nm, and are in anatase, rutile, and oxygen‐deficient phases. The nanospheres exhibit excellent optical absorption covering the wavelength range from 240 to 2600 nm. It is also found that the low voltage during plasma electrolysis could result in more anatase phases of TiO2. The mechanisms responsible for the nanosphere formation and the wide spectral absorption were also discussed.
Net spin and polarization components of the spin density for the single determinant in the basis of paired orbitals
Authors: Ruzankin Sergey Ph. , Lyskov Igor , Zilberberg Igor L. 
Published: June 2012

AbstractA decomposition of the spin density into the net spin density and polarization density for the unrestricted Kohn–Sham (KS) determinant in the basis of Löwdin–Amos–Hall paired orbitals (PO) is derived. In PO basis set, the net spin part of spin density is only determined by the manifold of occupied α‐spin orbitals which do not overlap with occupied β‐spin orbitals. In its turn, the polarization part is associated with the pairs of overlapping α and β orbitals. The decreased overlap in these pairs corresponds to the increased degree of spin polarization. As an example of the developed spin density decomposition, the complex of FeO with nitrobenzene (taken in the state with spin projection of Sz = 2) is considered for the B3LYP solution revealing substantial spin contamination for the KS determinant. The spin density decomposition predicts for this complex appreciable polarization density over the whole complex while the net spin density remains counter intuitive almost intact at FeO center. This result changes presumed mechanism of metal‐to‐ligand transfer of unpaired electrons from paramagnetic center to diamagnetic ligand having a high electron affinity. © 2012 Wiley Periodicals, Inc.
O (3P) + CH3SH reactions: Structures, energetics, and kinetics
Authors: Cardoso Daniely Verônica Viana , de Araújo Ferrão Luiz Fernando , Spada Rene Felipe Keidel , Roberto‐Neto Orlando , Machado Francisco Bolivar Correto 
Published: June 2012

AbstractThe structures, barrier heights, reaction enthalpies, and thermal rate constants of four reaction paths involving hydrogen abstraction and addition processes between O and CH3SH were computed using the Møller–Plesset perturbation theory at the second order level (MP2) and BB1K methods with the aug‐cc‐pV(T+d)Z basis set. A more accurate evaluation of the energetic of these reaction systems are performed by extrapolating the single point CCSD(T) energies to the complete basis set (CBS) limit approach using the BB1K and MP2/aug‐cc‐pV(T+d)Z geometries. The best estimates of the adiabatic barrier heights, determined using the CCSD(T)/CBS//(BB1K or MP2)/aug‐cc‐pV(T+d)Z method, are between 0.5 and 1.0 kcal mol−1 (R1, CH3S + OH), 5.3 and 5.5 kcal mol−1 (R2, CH2SH + OH), 1.3 and 2.3 kcal mol−1 (R3, CH3 + HSO), and 1.6 and 2.9 kcal mol−1 (R4, CH3SO + H). The thermal rate constants calculated using the dual‐level direct dynamics by variational transition state theory with interpolated single‐point energy corrections are in good agreement with experimental results. The calculated branching ratios at 300 K are 0.91:0.01:0.05:0.03 for the reactions paths R1–R4, respectively, which indicate that hydrogen abstraction from the SH group is the main reaction path. © 2012 Wiley Periodicals, Inc.
The influence of emotional intelligence (EI) on coping and mental health in adolescence: Divergent roles for trait and ability EI
Authors: Davis Sarah K. , Humphrey Neil 
Published: June 2012

ABSTRACTTheoretically, trait and ability emotional intelligence (EI) should mobilise coping processes to promote adaptation, plausibly operating as personal resources determining choice and/or implementation of coping style. However, there is a dearth of research deconstructing if/how EI impacts mental health via multiple coping strategies in adolescence. Using path analysis, the current study specified a series of multiple‐mediation and conditional effects models to systematically explore interrelations between coping, EI, depression and disruptive behaviour in 748 adolescents (mean age = 13.52 years; SD = 1.22). Results indicated that whilst ability EI influences mental health via flexible selection of coping strategies, trait EI modifies coping effectiveness; specifically, high levels of trait EI amplify the beneficial effects of active coping and minimise the effects of avoidant coping to reduce symptomotology. However, effects were selective with respect to coping style and outcome. Implications for interventions are discussed alongside directions for future research.
A systematic review of maternal and infant outcomes following magnesium sulfate for pre‐eclampsia/eclampsia in real‐world use
Authors: McDonald Sarah D. , Lutsiv Olha , Dzaja Nancy , Duley Lelia 
Published: June 2012

AbstractBackgroundEvidence from RCTs shows that magnesium sulfate reduces the risk of seizures and mortality for women with pre‐eclampsia/eclampsia. However, it has been argued that outcomes within trials may not reflect real‐world outcomes with the same intervention.ObjectiveTo assess whether outcomes for women with pre‐eclampsia/eclampsia who received magnesium sulfate in the real world were comparable to those in RCTs.Search strategyEMBASE and MEDLINE were searched (January 1990–July 2010).Selection criteriaCohort, before‐and‐after, and serial cross‐sectional studies were included. Participants were women with eclampsia who received magnesium sulfate or another anticonvulsant, and women with pre‐eclampsia who received magnesium sulfate or no anticonvulsant. Primary outcomes were death (maternal, fetal, neonatal) or recurrent seizures.Data collection and analysisData were extracted independently by 2 reviewers.Main resultsSix studies (1831 women with eclampsia) were included, from academic centers in Bangladesh, India, Pakistan, and Nigeria, together with 2 population‐based UK studies. Magnesium sulfate for eclampsia was associated with lower risks of maternal death, recurrent seizure, and major morbidity; for pre‐eclampsia, it was associated with lower risks of eclampsia.ConclusionImprovements in maternal outcome with magnesium sulfate for pre‐eclampsia/eclampsia in real‐world use are comparable to those reported in RCTs.
Relative Zariski Open Objects
Authors: Marty Florian 
Published: June 2012

AbstractIn [TV], Bertrand Toën and Michel Vaquié define a scheme theory for a closed monoidal category (,⊗, 1) One of the key ingredients of this theory is the definition of a Zariski topology on the category of commutative monoidal objects in . The purpose of this article is to prove that under some hypotheses, Zariski open subobjects of affine schemes can be classified almost as in the usual case of rings (ℤ-mod,⊗,ℤ). The main result states that for any commutative monoidal object A in , the locale of Zariski open subobjects of the affine scheme Spec(A) is associated to a topological space whose points are prime ideals of A and whose open subsets are defined by the same formula as in rings. As a consequence, we can compare the notions of scheme over in [D] and in [TV].
KK-Theory and Spectral Flow in von Neumann Algebras
Authors: Kaad J. , Nest R. , Rennie A. 
Published: June 2012

AbstractWe present a definition of spectral flow for any norm closed idealJin any von Neumann algebraN.Given a path of selfadjoint operators inNwhich are invertible inN/J, the spectral flow produces a class inKo(J).Given a semifinite spectral triple (A, H, D) relative to (N, τ) withAseparable, we construct a class [D] ∈KK1(A, K(N)). For a unitaryu∈A, the von Neumann spectral flow betweenDandu*Duis equal to the Kasparov product [u]A[D], and is simply related to the numerical spectral flow, and a refinedC*-spectral flow.
On the coupled time-harmonic motion of deep water and a freely floating body: trapped modes and uniqueness theorems
Authors: Kuznetsov Nikolay , Motygin Oleg 
Published: June 2012

AbstractWe investigate the time-harmonic small-amplitude motion of the mechanical system that consists of water and a body freely floating in it; water occupies a half-space, whereas the body is either surface-piercing or totally submerged. As a mathematical model of this coupled motion, we consider a spectral problem (the spectral parameter is the frequency of oscillations), for which the following results are obtained. The total energy of the water motion is finite and the equipartition of energy holds for the whole system. For any value of frequency, infinitely many eigensolutions are constructed and each of them consists of a non-trivial velocity potential and the zero vector describing the motion of the body; the latter means that trapping bodies (infinitely many of them are found) are motionless although they float freely. They are surface-piercing, have axisymmetric submerged parts and are obtained by virtue of the so-called semi-inverse procedure. We also prove that certain restrictions on the body geometry (which are violated for the constructed trapping bodies) guarantee that the problem has only a trivial solution for frequencies that are sufficiently large being measured in terms of a certain dimensionless quantity.