bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of epilepsy and selected antiepileptic drugs on risk of myocardial infarction, stroke, and death in patients with or without previous stroke: a nationwide cohort study
Authors: Olesen Jonas Bjerring , Abildstrøm Steen Zabell , Erdal Jesper , Gislason Gunnar H. , Weeke Peter , Andersson Charlotte , Torp‐Pedersen Christian , Hansen Peter Riis 
Published: July 2011

ABSTRACTPurposePatients with epilepsy have increased morbidity and mortality. We evaluated the risk of myocardial infarction (MI), stroke, and death associated with epilepsy and examined if this risk was modified by treatment with antiepileptic drugs (AEDs).MethodsA cohort consisting of the Danish population was followed from January 1997 to December 2006. The risk of MI, stroke, cardiovascular death, and all‐cause death associated with epilepsy was estimated by multivariable Cox proportional hazard models stratified for occurrence of previous stroke. AED use was determined at baseline, and risks associated with exposure to individual AEDs were examined in patients with epilepsy.ResultsIn patients without previous stroke, AED‐treated epilepsy was associated with an increased risk of MI (hazard ratio [HR], 1.09; 95%CI, 1.00–1.19), stroke (HR, 2.22; 95%CI, 2.09–2.36), cardiovascular death (HR, 1.64; 95%CI, 1.57–1.72), and all‐cause death (HR, 1.92; 95%CI, 1.86–1.97). Compared with carbamazepine monotherapy, valproate was associated with a decreased risk of MI (HR, 0.72; 95%CI, 0.59–0.87) and stroke (HR, 0.86; 95%CI, 0.76–0.96), oxcarbazepine and phenobarbital with increased risk of cardiovascular death (HR, 1.10; 95%CI, 1.02–1.19 and HR, 1.08; 95%CI, 1.00–1.17, respectively) and all‐cause death (HR, 1.11; 95%CI, 1.05–1.18 and HR, 1.18; 95%CI, 1.12–1.25, respectively), and oxcarbazepine with increased risk of stroke (HR, 1.21; 95%CI, 1.10–1.34), in patients with epilepsy.ConclusionsPatients with epilepsy exhibit increased risk of MI, stroke, cardiovascular death, and all‐cause death. Compared with carbamazepine monotherapy, valproate may decrease, and oxcarbazepine and phenobarbital may increase, the risk of adverse cardiovascular events in these patients. Copyright © 2011 John Wiley & Sons, Ltd.
Regioselective grignard metathesis reaction of 2,5‐dibromo‐3‐(6′‐hexylpyridine‐2′‐yl)thiophene and kumada coupling polymerization
Authors: Takagi Koji , Joo Hyunho , Yamashita Yusuke , Kawagita Eiki , Torii Chikako 
Published: July 2011

Abstract2,5‐Dibromo‐3‐(6′‐hexylpyridine‐2′‐yl)thiophene (DBPyTh) was synthesized by the Suzuki coupling reaction between two aromatic compounds followed by the bromination. The Grignard metathesis reaction of DBPyTh with isopropylmagnesium chloride proceeded in 85% conversion and the regioselective halogen–metal exchange at the 2‐position was confirmed. Namely, 5‐bromo‐2‐chloromagnesio‐3‐(6′‐hexylpyridine‐2′‐yl)thiophene and 2‐bromo‐5‐chloromagnesio‐3‐(6′‐hexylpyridine‐2′‐yl)thiophene were generated in 90:10 molar ratio. Subsequently, the Kumada coupling polymerization was carried out using 1,3‐bis(diphenylphosphinopropane)nickel(II) dichloride to obtain poly(3‐(6′‐hexylpyridine‐2′‐yl)thiophene) (PolyPyTh). The polymer molecular weight could be roughly controlled by the catalyst concentration and the molecular weight distribution ranged from 1.25 to 1.80. The gas chromatograph analysis indicated that 5‐bromo‐2‐chloromagnesio‐3‐(6′‐hexylpyridine‐2′‐yl)thiophene was preferentially polymerized in 90% conversion and the percentage of the head‐to‐tail content (regioregularity) was calculated to be 96%. The matrix‐assisted laser desorption/ionization time‐of‐fright mass spectrum indicated that both polymer chain ends were substituted with the hydrogen atom. The absorption maxima of polymer in CHCl3 and thin film were observed at 447 and 457 nm, respectively, which were blue‐shifted compared with poly(3‐(4′‐octylphenyl)thiophene). From the CV measurement of the polymer thin film, highest occupied molecular orbital (HOMO) (−5.31 eV) and lowest unoccupied molecular orbital (LUMO) (−3.76 eV) energy levels were calculated from the oxidation and reduction onset potentials, respectively, and the electrochemical band gap energy was determined to be 1.62 eV. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Synthesis and characterization of amphiphilic heterograft copolymers with PAA and PS side chains via “Grafting from” approach
Authors: Fan Xiaoshan , Wang Guowei , Zhang Zhen , Huang Junlian 
Published: July 2011

AbstractThe amphiphilic heterograft copolymers poly(methyl methacrylate‐co‐2‐(2‐bromoisobutyryloxy)ethyl methacrylate)‐graft‐(poly(acrylic acid)/polystyrene) (P(MMA‐co‐BIEM)‐g‐(PAA/PS)) were synthesized successfully by the combination of single electron transfer‐living radical polymerization (SET‐LRP), single electron transfer‐nitroxide radical coupling (SET‐NRC), atom transfer radical polymerization (ATRP), and nitroxide‐mediated polymerization (NMP) via the “grafting from” approach. First, the linear polymer backbones poly(methyl methacrylate‐co‐2‐(2‐bromoisobutyryloxy)ethyl methacrylate) (P(MMA‐co‐BIEM)) were prepared by ATRP of methyl methacrylate (MMA) and 2‐hydroxyethyl methacrylate (HEMA) and subsequent esterification of the hydroxyl groups of the HEMA units with 2‐bromoisobutyryl bromide. Then the graft copolymers poly(methyl methacrylate‐co‐2‐(2‐bromoisobutyryloxy)ethyl methacrylate)‐graft‐poly(t‐butyl acrylate) (P(MMA‐co‐BIEM)‐g‐PtBA) were prepared by SET‐LRP of t‐butyl acrylate (tBA) at room temperature in the presence of 2,2,6,6‐tetramethylpiperidin‐1‐yloxyl (TEMPO), where the capping efficiency of TEMPO was so high that nearly every TEMPO trapped one polymer radicals formed by SET. Finally, the formed alkoxyamines via SET‐NRC in the main chain were used to initiate NMP of styrene and following selectively cleavage of t‐butyl esters of the PtBA side chains afforded the amphiphilic heterograft copolymers poly(methyl methacrylate‐co‐2‐(2‐bromoisobutyryloxy)ethyl methacrylate)‐graft‐(poly(t‐butyl acrylate)/polystyrene) (P(MMA‐co–BIEM)‐g‐(PtBA/PS)). The self‐assembly behaviors of the amphiphilic heterograft copolymers P(MMA‐co–BIEM)‐g‐(PAA/PS) in aqueous solution were investigated by AFM and DLS, and the results demonstrated that the morphologies of the formed micelles were dependent on the grafting density. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Annealing of melt‐crystallized polyethylene and its influence on microstructure and mechanical properties: A comparative study on branched and linear polyethylenes
Authors: Song Shijie , Feng Jiachun , Wu Peiyi 
Published: July 2011

AbstractAnnealing treatments have been performed on two melt‐crystallized polyethylenes (PE) with different topologies, namely highly branched and linear PE, to comparatively investigate the microstructural evolution and corresponding changes of mechanical property. It shows that annealing induced different degrees of variation in the lamellar rearrangement of the two PEs. Branched PE, which incorporates comonomers on the backbones, shows a more versatile annealing effect when compared with the linear counterpart. With respect to PEs, it is for the first time a connection was made between the annealing‐induced microstructural changes and an important but less understood property known as heat distortion temperature (HDT). It shows that at lower annealing temperatures, the improvement of HDT can be well correlated to the increased crystallinity induced by lamellar rearrangement for both PEs. However, for branched PE, the contribution of crystallinity is weakened at higher annealing temperatures and the dominant factor on HDT was replaced by the relaxation of lamellar structure. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 49: 1347–1359, 2011
In situ synthesis of ZnO nanocrystal/PET hybrid nanofibers via electrospinning
Authors: Zhang Junhua , Wen Bin , Wang Feng , Ding Yanfen , Zhang Shimin , Yang Mingshu 
Published: July 2011

AbstractHybrid nanofibers of ZnO precursors/PET were fabricated by electrospinning a nonaqueous poly(ethylene terephthalate) (PET) solution containing zinc acetate dihydrate. Scanning electron microscopy images showed that the as prepared nanofibers had smooth and uniform surfaces, and the diameter was decreased with increasing zinc acetate dihydrate content and reducing PET concentration. After the treatment by a mild process of immersing the fibers in ammonia‐ethanol mixtures (pH ≈ 9–11), the surface of the nanofibers became rough during the formation of ZnO nanocrystals in the fibers. High resolution transmission electron microscopy images showed that the mean particle size became smaller with increasing diameter of the polymer fibers and decreasing content of ZnO. Fourier transform infrared spectra confirmed the ZnO formation in the hybrid nanofibers. X‐ray diffractometry patterns indicated that ZnO had the Wurtzite structure. The formation and growth of ZnO nanocrystals in the nanofiber matrices was also influenced by the various other parameters, that is, the pH value of the reaction solution, the content of zinc acetate dihydrate within the fibers, the reaction time and temperature. Photoluminescence spectra under excitation at 300 nm revealed a broad and intense ultraviolet emission. The UV‐visible diffuse reflectance spectra demonstrated the blue shift in the absorbance curve, which was ascribed to the quantum confinement effects of ZnO nanoparticles in the hybrid materials. These hybrid nanofibers can potentially be used in light emitters, chemical sensors, photo‐catalysts and solar cells. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 49: 1360–1368, 2011
Duality in strongly interacting systems: 𝒩 = 2 SUSY Yang‐Mills and the quantum Hall effect
Authors: Dolan B.P. 
Published: July 2011

AbstractClassical solutions of the vacuum Maxwell's equations exhibit a SO(2) duality symmetry, which is enhanced to Sl(2,R) when dilaton and axion fields are included. Quantum effects break this symmetry but semi‐classically Sl(2,Z) symmetry, or a sub‐group thereof, survives in Dirac‐Schwinger‐Zwanziger quantisation. Even this symmetry is expected to be broken in the full theory of quantum electrodynamics, but a modular sub‐group survives as an infinite discrete symmetry of the vacua of 𝒩 = 2 supersymmetric Yang‐Mills theory. An analogous situation occurs in the quantum Hall effect, where different quantum Hall states are related by a modular symmetry which is a sub‐group of Sl(2,Z). The similarities between the quantum Hall effect and supersymmetric Yang‐Mills are reviewed and a possible link via the gauge/gravity correspondence is described. Scaling exponents in the quantum Hall effect are derived using the gauge‐gravity correspondence.
Bifenthrin longevity at the termiticidal application rate
Authors: Peterson Chris J 
Published: July 2011

AbstractBACKGROUND: The longevity, mobility and insecticidal activity of bifenthrin at the termiticidal application rate for perimeter treatment were investigated in packed‐soil columns in the laboratory and greenhouse.RESULTS: Bifenthrin was not detected in the eluates of packed‐soil cones over a period of 6 months. In larger pipe plots incorporating bifenthrin into the top 15 cm of the soil, the compound degraded in a biphasic fashion. Within the treated soil, the effect of vegetation on the amount of bifenthrin remaining in the soil depended on soil depth and time, and soil half‐lives were longer in non‐vegetated soil. Bifenthrin residues were higher in the top 7.5 cm of soil and declined over time. Movement of bifenthrin into the top untreated soil depth was observed, but much less was observed in lower depths. The soil remained toxic to termites in 3 day and 7 day forced exposure bioassays for the 30 month duration of the study.CONCLUSIONS: Concentrations of bifenthrin will remain in the soil at levels sufficient to kill termites for more than 30 months. Published 2011 by John Wiley & Sons, Ltd.
Integrated management of Thrips tabaci (Thysanoptera: Thripidae) on onion in north‐western Italy: basic approaches for supervised control
Authors: Mautino Giulia C , Bosco Lara , Tavella Luciana 
Published: July 2011

AbstractBACKGROUND: Thrips tabaci Lindeman (Thysanoptera: Thripidae) is a major pest on onion, Allium cepa L., worldwide. In 2010, research was conducted in a commercial onion field in north‐western Italy in order (i) to evaluate the efficacy of different insecticides and of the SAR activator acibenzolar‐S‐methyl, (ii) to correlate thrips infestation levels with bulb size and weight at harvest and (iii) to implement a reliable thrips sampling method. Efficacy of the three active ingredients spinosad, lambda‐cyhalothrin and acibenzolar‐S‐methyl on local thrips populations were also evaluated in laboratory bioassays.RESULTS: During field surveys, the highest and the lowest thrips infestations were observed in plots treated with lambda‐cyhalothrin and with spinosad and acibenzolar‐S‐methyl respectively. The effectiveness of spinosad was also confirmed in laboratory bioassays. At harvest, bulb size and weight did not significantly differ between treatments. A high correlation with visual inspection made plant beating a suitable sampling method for routine practice, enabling a good estimate of thrips infestation.CONCLUSION: Damage caused by thrips is often not severe enough to warrant the frequent pesticide applications the crops receive in north‐western Italy. The use of spinosad and acibenzolar‐S‐methyl is suggested as an alternative to conventional insecticides for the preservation of natural enemies. Copyright © 2011 Society of Chemical Industry
Susceptibility of Aphelinus certus to foliar‐applied insecticides currently or potentially registered for soybean aphid control
Authors: Frewin Andrew J , Schaafsma Arthur W , Hallett Rebecca H 
Published: July 2011

AbstractBACKGROUND: Soybean aphid, a serious economic pest of soybean in North America, is currently managed by applying non‐selective foliar insecticides during outbreaks according to decision thresholds and crop maturity. Natural enemies, such as the parasitoid Aphelinus certus Yasnosh, potentially play an important role in suppressing soybean aphid. Using selective insecticides that preserve A. certus may enhance the biological control service they provide and thus prevent or reduce the severity of soybean aphid outbreaks. The toxicity of five insecticides (λ‐cyhalothrin, dimethoate, flonicamid, mineral oil, spirotetramat) and the biopesticide Beauveria bassiana to A. certus was assessed.RESULTS: The LD50 values of λ‐cyhalothrin and dimethoate were similar; however, the hazard quotient of dimethoate was greater than that of λ‐cyhalothrin. In a screening bioassay, the descending order of toxicity for the recommended rates 48 h after application was dimethoate > λ‐cyhalothrin > flonicamid > mineral oil > Beauveria bassiana > spirotetramat.CONCLUSIONS: Overall, λ‐cyhalothrin and dimethoate were both harmful to A. certus. The other insecticides tested were harmless to A. certus and are potential candidates for inclusion in soybean aphid management programs. Copyright © 2011 Society of Chemical Industry
Ultrafast magnetization dynamics of Gd(0001): Bulk versus surface
Authors: Sultan Muhammad , Melnikov Alexey , Bovensiepen Uwe 
Published: July 2011

AbstractUltrafast laser‐induced demagnetization of Gd(0001) has been investigated by magneto‐induced optical second harmonic generation and the magneto‐optical Kerr effect which facilitate a comparison of surface and bulk dynamics. We observe pronounced differences in the transient changes of the surface and bulk sensitive magneto‐optical signals which we attribute to transfer of optically excited, spin‐polarized carriers between surface and bulk states of the Gd(0001) film. A fluence dependent analysis of the bulk magnetization dynamics results in a weak variation of the demagnetization time constant, which starts at about 0.7 ps and increases by 10% within a fluence variation up to 1 mJ/cm2. We compare these results with fluence dependent changes in the transient energy density calculated by the two temperature model. The determined characteristic times of excess energy transfer from the electron system to the lattice, which is mediated by e–ph scattering, range from 0.2 to 0.6 ps. Such a more pronounced fluence dependent change in the characteristic time compared to the observed rather weakly varying demagnetization times suggests a more advanced description of the optically excited state than by the two‐temperature model.
Magnetic properties and superconductivity of nano‐width crystallite interfaces of bicrystals and tricrystals of Bi1−x–Sbx (x ≤ 0.2) alloys
Authors: Muntyanu F. M. , Gilewski A. , Nenkov K. , Zaleski A. J. , Chistol V. 
Published: July 2011

AbstractThe magnetic properties of bicrystals and tricrystals of Bi1−x–Sbx (x ≤ 0.2) alloys were studied in a temperature range of 1.8–100 K. The ferromagnetic‐like hysteresis loops are found in tricrystals and some bicrystals. We revealed that nano‐width crystallite interfaces (∼100 nm) exhibit superconducting behavior, whereas the single crystalline samples are not superconducting. The onset of superconducting transition (∼36 K) in some of these interfaces considerably exceeds the values of other semimetal nanoobjects.
Structure and reactivity of baicalein radical cation
Authors: Marković Zoran S. , Marković Svetlana , Dimitrić Marković Jasmina M. , Milenković Dejan 
Published: July 2011

AbstractNeutral baicalein, corresponding radical cation, and three possible radicals obtained by proton removal from the radical cation were investigated using density functional theory. The structure and UV spectrum of baicalein were very well reproduced by the B3LYP/6‐311+G(2df,p) level of theory. The results showed that the loss of an electron from baicalein molecule induced the transfer of H4 to O5. The reasons for this rearrangement were pointed out. It was found that delocalization of spin density is most pronounced in the thermodynamically most stable C6OH radical. It was supposed that this radical plays a significant role in the antioxidant activity of baicalein within the single‐electron transfer‐proton transfer mechanism. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Quantifying the performance of conventional DFT methods on a class of difficult problems: The interaction (hyper)polarizability of two water molecules as a test case
Authors: Maroulis George 
Published: July 2011

AbstractWe have investigated the predictive capability of a widely used group of density functional theory (DFT) methods on the interaction (hyper)polarizability of the two water molecules in the water dimer. We find that compared with conventional ab initio methods, DFT gives a different picture of the dipole moment and (hyper) polarizability for the water monomer and dimer. In addition, the DFT methods tested in this work predict for the water dimer a systematically higher value of the differential interaction‐induced second hyperpolarizability per water molecule, DHPM = [
$ \bar{\gamma} $(H2O)2]/2 −
$ \bar \gamma $
(H2O) than the ab initio ones. The interaction‐induced mean polarizability and second hyperpolarizability is predicted to be small and positive for all DFT methods used here. The respective quantities predicted by conventional post‐Hartree–Fock ab initio methods are also quite small but negative. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012
EXISTING AND FUTURE CHALLENGES: THE CONCEPT OF SUCCESSFUL FISH PASSAGE IN SOUTH AMERICA
Authors: Pompeu P. S. , Agostinho A. A. , Pelicice F. M. 
Published: July 2011

ABSTRACTMost of the large rivers of South America are impounded mainly for hydropower production. The construction of fish passes has been one of the strategies adopted by Brazilian authorities and the energy sector to diminish the effects of these barriers on migratory fish communities. Despite the high investments and efforts involved, most facilities have been considered ineffective for conservation purposes. Decades of poor monitoring and the lack of specific studies have limited our knowledge on the real role of fish passes. Efficiency has been frequently defined as the proportion of fish that ascend a fish passage facility, compared to the shoal size that reaches the dam. Inspired by the notion that fishes accumulated below the dam need to migrate upstream, the quantity of fish passed upstream historically indicated successful management, as generally inferred by the fish abundance inside the fish pass. We propose a new concept for estimating fish pass efficiency for South American rivers, based on the capability of the fish pass to maintain viable populations. This broader approach is necessary because knowledge of fish habitats below and above the pass, plus the feasibility of downstream movements of eggs, larvae and adults through the reservoir and past the dam, is needed for assessing whether a fish pass is working as a conservation tool. Copyright © 2011 John Wiley & Sons, Ltd.
Deformation and Failure of Open‐Cell Foams Made of TRIP‐Steel‐ZrO2‐Composite Materials: Experimental Observations Versus Numerical Simulations
Authors: Sieber T. , Mühlich U. , Liedke T. , Ballaschk U. , Berek H. , Aneziris C. G. , Ehinger D. , Wolf S. , Krüger L. 
Published: July 2011

AbstractThe aim of the study is to clarify how far it is possible to describe the mechanical behavior of novel TRIP‐Steel/Mg‐PSZ composite open‐cell foam structures using beam networks generated from random tessellations. Conventional compression tests were performed with various foam samples. Furthermore, the deformation of open‐cell composite foams was observed as well by X‐ray computed tomography (XCT). Up to a compressive strain of 20% different stages of deformation could be observed. Respective bulk samples were manufactured by powder metallurgy and tested in order to determine the mechanical properties of the bulk material. Numerical simulations were employed based on the suitable modeling of foams exposed to mechanical loading. The predictions of the simulation are compared with the results of the deformation experiments.
Reinforcing Mechanism of Mg‐PSZ Particles in Highly‐Alloyed TRIP Steel
Authors: Martin S. , Richter S. , Decker S. , Martin U. , Krüger L. , Rafaja D. 
Published: July 2011

AbstractDense TRIP‐matrix composites containing 5 vol.% Mg‐PSZ as reinforcing phase were produced by employing the spark plasma sintering technique. A continuous and seamless interface between the ceramic particles and the steel matrix was achieved. Compression tests revealed better mechanical properties of the 5 vol.% Mg‐PSZ‐TRIP steel composites in comparison with both, pure and Al2O3 reinforced TRIP steel. The underlying deformation mechanism within the austenitic matrix entailed a pronounced martensite formation. An additional phase transformation was observed within the ZrO2 particles. The enhanced mechanical properties of the 5 vol.% Mg‐PSZ composite are dedicated to the transformation strengthening of the ceramic particles. Finally a model of the reinforcing mechanism is proposed.