bluuebunny/crossref_metadata_2025_split huggingface dataset:
Magnetic source imaging for the surgical evaluation of electroencephalography-confirmed secondary bilateral synchrony in intractable epilepsy
Authors: Chang Edward F. , Nagarajan Srikantan S. , Mantle Mary , Barbaro Nicholas M. , Kirsch Heidi E. 
Published: July 2009

Object
Routine scalp electroencephalography (EEG) cannot always distinguish whether generalized epileptiform discharges are the result of primary bilateral synchrony or secondary bilateral synchrony (SBS) from a focal origin; this is an important distinction because the latter may be amenable to resection. Whole-head magnetoencephalography (MEG) has superior spatial resolution compared with traditional EEG, and can potentially elucidate seizure foci in challenging epilepsy cases in which patients are undergoing evaluation for surgery.

Methods
Sixteen patients with medically intractable epilepsy in whom SBS was suspected were referred for magnetic source (MS) imaging. All patients had bilateral, synchronous, widespread, and most often generalized spike-wave discharges on scalp EEG studies, plus some other clinical (for example, seizure semiology) or MR imaging feature (for example, focal lesion) suggesting focal onset and hence possible surgical candidacy. The MS imaging modality is the combination of whole-head MEG and parametric reconstruction of corresponding electrical brain sources. An MEG and simultaneous EEG studies were recorded with a 275-channel whole-head system. Single-equivalent current dipoles were estimated from the MEG data, and dipole locations and orientations were superimposed on patients' MR images.

Results
The MS imaging studies revealed focal dipole clusters in 12 (75%) of the 16 patients, of which a single dipole cluster was identified in 7 patients (44%). Patient age, seizure type, duration of disease, video-EEG telemetry, and MR imaging results were analyzed to determine factors predictive of having clusters revealed on MS imaging. Of these factors, only focal MR imaging anatomical abnormalities were associated with dipole clusters (chi-square test, p = 0.03). Selective resections (including the dipole cluster) in 7 (87%) of 8 patients resulted in seizure-free or rare seizure outcomes (Engel Classes I and II).

Conclusions
Magnetic source imaging may provide noninvasive anatomical and neurophysiological confirmation of localization in patients in whom there is a suspicion of SBS (based on clinical or MR imaging data), especially in those with an anatomical lesion. Identification of a focal seizure origin has significant implications for both resective and nonresective treatment of intractable epilepsy.
Periodic TiO2 Nanorod Arrays with Hexagonal Nonclose‐Packed Arrangements: Excellent Field Emitters by Parameter Optimization
Authors: Li Yue , Fang Xiaosheng , Koshizaki Naoto , Sasaki Takeshi , Li Liang , Gao Shuyan , Shimizu Yoshiki , Bando Yoshio , Golberg Dmitri 
Published: July 2009

AbstractPeriodic TiO2 nanorod arrays with hexagonal nonclose‐packed (hncp) arrangements are synthesized by pulsed laser deposition (PLD) using polystyrene colloidal monolayers as templates and with subsequent annealing in air. The hncp‐array formation is governed by in situ volume shrinkage of amorphous TiO2 nanorods in the crystallizing process during annealing. The array periodicity can easily be tuned by different sphere sizes of the colloidal template, whereas the distance between neighboring nanorods can be controlled by altering the background gas pressure during the PLD process, at a given periodicity for the nanorod array. Parameter‐controlled growth is helpful for investigating and optimizing the parameter‐dependent field‐emission properties. The hncp nanorod array exhibits an enhanced field‐emission (FE) performance compared to both particle films and nanorod arrays with top aggregation. With an increase in periodicity of a hncp nanorod array, the field‐enhancement factor decreases and the turn‐on FE field increases. FE characteristics can be further enhanced by increasing the distance between adjacent nanorods while maintaining the same periodicity. The parameter‐optimized results suggest that the arrays with a smaller periodicity and a larger distance display the best FE performance and could be highly valuable for designing field‐emission devices based on these periodic nanorod arrays.
Materials for a Reliable Solid‐State Dye Laser at the Red Spectral Edge
Authors: Garcia‐Moreno Inmaculada , Costela Angel , Martin Virginia , Pintado‐Sierra Mercedes , Sastre Roberto 
Published: July 2009

AbstractIn the search to extend the tuning range of solid‐state dye lasers (SSDLs) to the red‐edge spectral region, new photosensitive materials have been designed and synthesized based on six commercial dyes (sulforhodamine B, perylene red, rhodamine 640, LDS698, LDS722, and LDS730) incorporated into different linear, crosslinked, fluorinated, and sililated polymeric matrices. Under transversal pumping at 532 nm, these materials exhibit highly efficient, stable, as well as wavelength‐tunable laser action from the visible‐to‐NIR spectral region (575–750 nm). The lasing performance of the materials doped with perylene and xanthene dyes is, to the best of our knowledge, the highest achieved to date for these chromophores when incorporated into organic, inorganic, or hybrid matrices. Regarding the LDS derivatives, this is the first time that laser action from these dyes in solid‐state media is reported. These particular characteristics have impelled the building of the first prototype SSDL that is compact, versatile, and easy to handle.
Printable Ferroelectric PVDF/PMMA Blend Films with Ultralow Roughness for Low Voltage Non‐Volatile Polymer Memory
Authors: Kang Seok Ju , Park Youn Jung , Bae Insung , Kim Kap Jin , Kim Ho‐Cheol , Bauer Siegfried , Thomas Edwin L. , Park Cheolmin 
Published: July 2009

AbstractHere, a facile route to fabricate thin ferroelectric poly(vinylidene fluoride) (PVDF)/poly(methylmethacrylate) (PMMA) blend films with very low surface roughness based on spin‐coating and subsequent melt‐quenching is described. Amorphous PMMA in a blend film effectively retards the rapid crystallization of PVDF upon quenching, giving rise to a thin and flat ferroelectric film with nanometer scale β‐type PVDF crystals. The still, flat interfaces of the blend film with metal electrode and/or an organic semi‐conducting channel layer enable fabrication of a highly reliable ferroelectric capacitor and transistor memory unit operating at voltages as low as 15 V. For instance, with a TIPS‐pentacene single crystal as an active semi‐conducting layer, a flexible ferroelectric field effect transistor shows a clockwise I–V hysteresis with a drain current bistability of 103 and data retention time of more than 15 h at ±15 V gate voltage. Furthermore, the robust interfacial homogeneity of the ferroelectric film is highly beneficial for transfer printing in which arrays of metal/ferroelectric/metal micro‐capacitors are developed over a large area with well defined edge sharpness.
Highly Emitting Neutral Dinuclear Rhenium Complexes as Phosphorescent Dopants for Electroluminescent Devices
Authors: Mauro Matteo , Procopio Elsa Quartapelle , Sun Yinghui , Chien Chen‐Han , Donghi Daniela , Panigati Monica , Mercandelli Pierluigi , Mussini Patrizia , D'Alfonso Giuseppe , De Cola Luisa 
Published: July 2009

AbstractA series of neutral, dinuclear, luminescent rhenium(I) complexes suitable for phosphorescent organic light emitting devices (OLEDs) is reported. These compounds, of general formula [Re2(µ‐Cl)2(CO)6(µ‐1,2‐diazine)], contain diazines bearing alkyl groups in one or in both the β positions. Their electrochemical and photophysical properties are presented, as well as a combined density functional and time‐dependent density functional study of their geometry, relative stability and electronic structure. The complexes show intense green/yellow emissions in toluene solution and in the solid state and some of the complexes possess high emission quantum yields (ϕ = 0.18–0.22 for the derivatives with disubstituted diazines). In butyronitrile glass, at 77 K, due to the charge transfer character of the lowest (emitting) excited state, strong blue shift of the emission is observed, accompanied by a strong increase in the lifetime values. The highest‐performing emitting complex, containing cyclopentapyridazine as ligand, is tested in a polymer‐based light‐emitting device, with poly(9‐vinylcarbazole) as matrix, as well as in a device obtained by vacuum sublimation of the complex in the 2,7‐bis(diphenylphosphine oxide)‐9‐(9‐phenylcarbazol‐3‐yl)‐9‐phenylfluorene (PCF) matrix. This represents the first example of devices obtained with a rhenium complex which can be sublimed and is solution processable. Furthermore, the emission is the bluest ever reported for electrogenerated luminescence for rhenium complexes.
Stimulation of the subthalamic nucleus and impulsivity: Release your horses
Authors: Ballanger Benedicte , van Eimeren Thilo , Moro Elena , Lozano Andres M. , Hamani Clement , Boulinguez Philippe , Pellecchia Giovanna , Houle Sylvain , Poon Yu Yan , Lang Anthony E. , Strafella Antonio P. 
Published: July 2009

AbstractObjectiveIn Parkinson disease (PD) patients, deep brain stimulation (DBS) of the subthalamic nucleus (STN) may contribute to certain impulsive behavior during high‐conflict decisions. A neurocomputational model of the basal ganglia has recently been proposed that suggests this behavioral aspect may be related to the role played by the STN in relaying a “hold your horses” signal intended to allow more time to settle on the best option. The aim of the present study was 2‐fold: 1) to extend these observations by providing evidence that the STN may influence and prevent the execution of any response even during low‐conflict decisions; and 2) to identify the neural correlates of this effect.MethodsWe measured regional cerebral blood flow during a Go/NoGo and a control (Go) task to study the motor improvement and response inhibition deficits associated with STN‐DBS in patients with PD.ResultsAlthough it improved Unified Parkinson Disease Rating Scale motor ratings and induced a global decrease in reaction time during task performance, STN‐DBS impaired response inhibition, as revealed by an increase in commission errors in NoGo trials. These behavioral effects were accompanied by changes in synaptic activity consisting of a reduced activation in the cortical networks responsible for reactive and proactive response inhibition.InterpretationThe present results suggest that although it improves motor functions in PD patients, modulation of STN hyperactivity with DBS may tend at the same time to favor the appearance of impulsive behavior by acting on the gating mechanism involved in response initiation. Ann Neurol 2009;66:817–824
Solvent‐free N‐nitrosation of secondary amines mediated by polymeric nitrosation reagent
Authors: Karimi Zarchi Mohammad Ali , Noei Jalil 
Published: July 2009

AbstractA combination of cross‐linked poly(4‐vinylpridininium) chloride [P4‐H] Cl, [II], and sodium nitrite or quaternized cross‐linked poly(N‐methyl‐4‐vinylpyridinum) nitrite [P4‐Me] NO2, [IV], was used as effective nitrosating agents for the N‐nitrosation of secondary amines under solvent‐free conditions in high yields. The spent polymeric reagents can usually be removed quantitatively and regenerated. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis of polymer‐grafted natural rubbers by radical photopolymerization of vinyl monomers initiated from the rubber chains
Authors: Derouet D. , Tran Quang Ngoc , Thuc H. Ha 
Published: July 2009

AbstractThe synthesis of polymer‐grafted natural rubbers (NRs) was considered through photopolymerization of vinyl monomers initiated from N,N‐diethyldithiocarbamate groups previously introduced onto cis 1,4‐polyisoprene units of NR chains. The development of the procedure was made with methyl methacrylate (MMA) as monomer. First, initiation of MMA photopolymerization was tested using a model molecule of the N,N‐diethyldithiocarbamate‐functionalized 1,4‐polyisoprene unit to verify the feasibility of the procedure considered. Then, MMA polymerization was successfully initiated from N,N‐diethyldithiocarbamate‐functionalized NR backbone used as macroinitiator, and the conditions of grafting were optimized. It was shown that MMA grafting could occur either in monomer medium, in solution in toluene, and in latex medium, and that the quantities of homopolymer formed were still low. Thereafter, grafting studies were performed with other vinyl monomers (styrene, methacrylonitrile, acrylamide, acrylic acid) showing that grafting efficiency depends essentially on the nature of the monomer. The method developed here was shown particularly well adapted for the synthesis of polymer‐grafted NR with monomers of low polarity. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Studies on epoxy/calcium carbonate nanocomposites
Authors: Jain Ritu , Narula A. K. , Choudhary Veena 
Published: July 2009

AbstractThe article describes the preparation of epoxy‐calcium carbonate nanocomposites using diaminodiphenyl sulfone (DDS) as a curing agent. The curing behavior of diglycidyl ether of bisphenol‐A (DGEBA) (1 mol) in the presence of varying amounts of nanocalcium carbonate was investigated by differential scanning calorimetry (DSC) using stoichiometric amounts of diaminodiphenyl sulphone (0.5 mol) as curing agent. The amount of calcium carbonate (∼ 44 nm) was varied from 2% to 10% (w/w). In the DSC scans of these samples, a broad exothermic transition due to curing was observed in the temperature range of 110–335°C. As expected, heat of curing decreased with increasing amount of nanocalcium carbonate; however it did not affect the curing characteristics, thereby indicating that the filler did not hinder the curing reaction. Thermal stability of DGEBA in the presence of varying amounts of nano‐CaCO3 after isothermal curing [(i.e., by heating in an air oven at 80°C (1 h), 100°C (1 h), 120°C (1.5 h), and 180°C (4 h)] was evaluated by thermogravimetry. All the samples were stable upto 350°C, and char yield at 800°C increased with increasing amount of nanocalcium carbonate. Rectangular bars were prepared by mixing DGEBA, DDS, and varying amounts of CaCO3 using silicone mold. The nanocomposites were characterized by X‐ray, scanning electron microscopy (morphological characterization), and dynamic mechanical analysis. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Removal of paraquat pesticide from aqueous solutions using a novel adsorbent material based on polyacrylamide and methylcellulose hydrogels
Authors: Aouada Fauze A. , Pan Zhongli , Orts William J. , Mattoso Luiz H. C. 
Published: July 2009

AbstractThis research studied the characteristics of poly(acrylamide) and methylcellulose (PAAm‐MC) hydrogels as a novel adsorbent material for removal of pesticide paraquat, from aqueous solution, with potential applications in curbing environmental risk from such herbicides. PAAm‐MC hydrogels with different acrylamide (AAm) and MC concentrations were prepared by a free‐radical polymerization method. The capability of the hydrogels in removing paraquat dichloride from aqueous solution was determined using UV–Vis analysis. The scanning electron microscopy method was used to study the morphological properties of the hydrogels, and swelling degree (Q) of the hydrogels was also measured. The entrapped MC in PAAm chains provoked significant changes in morphological, hydrophilic, and adsorption properties of the PAAm‐MC hydrogels. The adsorption capacity of hydrogels was strongly influenced by AAm, MC, and paraquat concentrations with the highest adsorption capacity (qeq = 14.3 mg g−1) was observed for hydrogels synthesized with 6.0% AAm with 0.75% MC swollen in 45.7 mg L−1 of paraquat solution. Freundlich model performed better than Langmuir model in describing the adsorption isotherm of PAAm‐MC/paraquat system, implying a heterogeneous surface. These results suggest that PAAm‐MC hydrogels are potentially viable absorbents for removal of paraquat pesticide from aqueous solution and cleaning water contaminated with dyes, heavy metals, and others pesticides. © 2009 Wiley Periodicals, Inc. Journal of Appl Polym Sci, 2009
Mesomorphic behavior and optical properties of liquid‐crystalline polysiloxanes bearing different chiral groups
Authors: Meng Fan‐Bao , Zhang Bao‐Yan , Lian Jiao , Wu Yan‐Peng , Li Xi‐Zhi , Yao Dan‐Shu 
Published: July 2009

AbstractA series of side‐chain liquid crystalline polysiloxanes bearing different chiral groups were synthesized with a cholesteric liquid crystalline monomer cholesteryl 2‐(4‐allyloxy‐benzoxy)‐succinate and a chiral monomer 2‐isopropyl‐5‐methyl‐cyclohexyl 4‐allyloxy‐benzoate. All the chiral polymers showed cholesteric mesophase with very wide mesophase temperature ranges. Along with phase morphology varied from solid state to isotropic state, the sample exhibited varied spectroscopic images, indicating different phase behaviors between mesophase and isotropic state. Optical properties of the polymers were characterized with circular polarization spectra and optical rotation analysis. The specific rotations of the chiral liquid crystalline polymers were all negative values and increased with increase of menthyl component in the polymer systems. As compared with corresponding monomers, the polymers showed significantly lower specific rotations, suggesting that the existence of polysiloxane main chains affect the molecule polarity. The selective light reflection maximum wavelength of the polymers at the same temperature shifted to short wavelength with decrease of cholesteryl component, indicating that the helical pitch becomes shorter due to induction of menthyl groups with high chiral properties. The temperature dependence of selective light reflection maximum wavelength was shifted to a longer wavelength region as the temperature decreased. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Removal of heavy‐metal ions by magnetic beads containing triazole chelating groups
Authors: Uzun Lokman , Kara Ali , Osman Bilgen , Yılmaz Erkut , Beşirli Necati , Denizli Adil 
Published: July 2009

AbstractThe aim of this study was to prepare magnetic beads that could be used for the removal of heavy‐metal ions from synthetic solutions. Magnetic poly(ethylene glycol dimethacrylate–1‐vinyl‐1,2,4‐triazole) [m‐poly(EGDMA–VTAZ)] beads were produced by suspension polymerization in the presence of a magnetite Fe3O4 nanopowder. The specific surface area of the m‐poly(EGDMA–VTAZ) beads was 74.8 m2/g with a diameter range of 150–200 μm, and the swelling ratio was 84%. The average Fe3O4 content of the resulting m‐poly(EGDMA–VTAZ) beads was 14.8%. The maximum binding capacities of the m‐poly(EGDMA–VTAZ) beads from aquous solution were 284.3 mg/g for Hg2+, 193.8 mg/g for Pb2+, 151.5 mg/g for Cu2+, 128.1 mg/g for Cd2+, and 99.4 mg/g for Zn2+. The affinity order on a mass basis was Hg2+ > Pb2+ > Cu2+ > Cd2+> Zn2+. The binding capacities from synthetic waste water were 178.1 mg/g for Hg2+, 132.4 mg/g for Pb2+, 83.5 mg/g for Cu2+, 54.1 mg/g for Cd2+, and 32.4 mg/g for Zn2+. The magnetic beads could be regenerated (up to ca. 97%) by a treatment with 0.1M HNO3. These features make m‐poly(EGDMA–VTAZ) beads potential supports for heavy‐metal removal under a magnetic field. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Investigation of the structural, thermal, mechanical, and optical properties of poly(methyl methacrylate) and poly(vinylidene fluoride) blends
Authors: Pawde S. M. , Deshmukh Kalim 
Published: July 2009

AbstractIn this investigation, poly(methyl methacrylate) (PMMA) and poly(vinylidene fluoride) (PVDF) blends (w/w) were prepared in a Brabender (South Hackensack, NJ) plasticorder with a thermoplastic mixing chamber (type W60) preheated at 180°C. These blends were further converted into films by a conventional solution casting method and characterized with Fourier transform infrared spectroscopy, differential scanning calorimetry, X‐ray diffraction, mechanical property measurements, impact strength testing, ultraviolet–visible spectroscopy, refractive‐index measurements, and contact‐angle study. The Fourier transform infrared results indicated that the compatibility between these two systems resulted from hydrogen bonding between the carbonyl group of PMMA and the CH2 group of PVDF. The thermal analysis showed depressions in the glass‐transition temperature, melting temperature, and crystallization temperature. The heat of crystallization increased with an increase in the PVDF content in the blend. An increase in the heat of crystallization meant an increase in the crystallinity. An increase in the cooling rate increased the crystallization rate. The improvement in the mechanical properties of the blend films indicated that the observed behavior was ascribable to a more coherent structure of the blends due to strong specific interactions between PMMA and PVDF chains. The impact strength analysis revealed a substantial increase in the impact strength from 21.64 to 38.52 J/m. Optical absorption spectra suggested the presence of an optical band gap energy that increased with an increase in the PVDF content in the blend. The contact angle against water increased with the PVDF content in the blend film, and this was caused by the hydrophobicity of PVDF due to the CF2 group of PVDF. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Development of polyurethanes with azo‐type chromophores for second‐order nonlinear optical applications
Authors: Tambe S. M. , Tasaganva R. G. , Jogul J. J. , Castiglione D. C. , Kariduraganavar M. Y. 
Published: July 2009

AbstractActive nonlinear optical nitro‐substituted thiazole, benzothiazole, and thiadiazole chromophores were prepared and condensed with tolylene‐2,4‐diisocyanate (TDI) and 4,4′‐methylenedi(phenyl isocyanate) (MDI) to yield a series of polyurethanes. The resulting polyurethanes were characterized with Fourier transform infrared, proton nuclear magnetic resonance, and ultraviolet–visible spectroscopy, differential scanning calorimetry, thermogravimetric analysis, and gel permeation chromatography. The weight‐average molecular weights of the polyurethanes ranged between 19,500 and 28,000 (weight‐average molecular weight/number‐average molecular weight = 1.71–2.15). All the polyurethanes exhibited excellent solubility in most common organic solvents, and this indicated that these polyurethanes offered good processability. The glass‐transition temperatures (Tg's) of the polyurethanes were in the range of 166–204°C. Among the polyurethanes, chromophores containing the nitrothiazole moiety exhibited lower Tg values in comparison with those of chromophores containing nitrobenzothiazole and nitrothiadiazole moieties. This was attributed to the small size of the nitrothiazole moiety in the polyurethane matrix. The polyurethanes containing a TDI backbone demonstrated relatively high Tg values in comparison with those of the polyurethanes containing an MDI backbone. This was a result of an enhancement of the rigidity caused by the incorporation of a toluene ring into the polyurethane backbone. The second harmonic generation (SHG) coefficients of the poled polyurethane films ranged from 67.29 to 105.45 pm/V at 1064 nm. High thermal endurance of the poled dipoles was observed for all the polyurethanes. This was attributed to the formation of extensive hydrogen bonds between urethane linkages. Furthermore, none of the developed polyurethanes showed SHG decay below 150°C, and this signified their acceptability for nonlinear optical devices. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009