bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of Some Organophosphorus and Azole Group Pesticides in Water Samples by Dispersive Liquid–Liquid Microextraction Coupled with GC/MS
Authors: Akdoğan Abdullah , Divrikli Ümit , Elçi Andlatif 
Published: December 2011

Abstract
A dispersive liquid–liquid microextraction (DLLME) procedure coupled with GC/MS detection is described for preconcentration and determination of some organophosphorus and azole group pesticides from water samples. Experimental conditions affecting the DLLME procedure were optimized by means of an experimental design. A mixture of 60 μL chlorobenzene (extraction solvent) and 750 μL acetonitrile (disperser solvent), 3.5 min extraction time, and 7.5 mL aqueous sample volume were chosen for the best recovery by DLLME. The linear range was 1.6–32 μg/L. The LOD ranged from 48.8 to 68.7 ng/L. The RSD values for organophosphorus and azole group pesticides at spiking levels of 3, 6, and 9 μg/L in water samples were in the range of 1.1 – 12.8%. The applicability and accuracy of the developed method were determined by analysis of spiked water samples, and the recoveries of the analyzed pesticides from artesian, stream, and tap waters at spiking levels of 3, 6, and 9 μg/L were 89.3–105.6, 89.5–103.0, and 92.0–111.3%, respectively.
Target Identification Using Drug Affinity Responsive Target Stability (DARTS)
Authors: Lomenick Brett , Jung Gwanghyun , Wohlschlegel James A. , Huang Jing 
Published: December 2011

AbstractDrug affinity responsive target stability (DARTS) is a general methodology for identifying and studying protein‐ligand interactions. The technique is based on the principle that when a small molecule compound binds to a protein, the interaction stabilizes the target protein's structure such that it becomes resistant to proteases. DARTS is particularly useful for the initial identification of the protein targets of small molecules, but can also be used to validate potential protein‐ligand interactions predicted or identified by other means and to estimate the affinity of interactions. The approach is simple and advantageous because it can be performed using crude cell lysates and other complex protein mixtures (without requiring purified proteins), and it uses native, unmodified small molecules. The protocols in this unit describe the general approach for performing DARTS experiments, which can be easily modified and scaled to fit project‐specific criteria. Curr. Protoc. Chem. Biol. 3:163‐180 © 2011 by John Wiley & Sons, Inc.
Learning and adaptation after diagnosis: The role of parent education
Authors: Reio Thomas G. , Fornes Sandra L. 
Published: December 2011

AbstractAfter diagnosis of a child's disability, the parent adapts to the situation by learning how to best optimize the child's learning and development, despite the disability. However, often parents are overwhelmed because many feel ill equipped to deal with the realities of handling the child's physical, psychological, and/or educational needs.
Challenges and opportunities of Operation Enduring Freedom/Operation Iraqi Freedom veterans with disabilities transitioning into learning and workplace environments
Authors: Ostovary Fariba , Dapprich Janet 
Published: December 2011

AbstractAs American communities welcome home U.S. troops from Iraq and Afghanistan, it is important to understand the unique set of circumstances for military personnel who served in these Middle Eastern regions. Differences in deployment, the type of injuries sustained, and the mixture of personnel continue to affect transitions from military service and reintegration into civilian life.
Validity of brief screening tools for cognitive impairment in rheumatoid arthritis and systemic lupus erythematosus
Authors: Julian Laura J. , Yazdany Jinoos , Trupin Laura , Criswell Lindsey A. , Yelin Edward , Katz Patricia P. 
Published: December 2011

AbstractObjectiveTo determine the validity of standardized screening assessments of cognitive functioning to detect neuropsychological impairment evaluated using a comprehensive battery in systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA).MethodsThis is a cross‐sectional study using a combined cohort of 139 persons with SLE and 82 persons with RA. Screening cut points were empirically derived using receiver operating characteristic curves and threshold selection methods. Screening measures included the Hopkins Verbal Learning Test‐Revised (HVLT‐R) learning and delayed recall indices and phonemic fluency, a composite measure of the 3 cognitive screening tests, and the Perceived Deficits Questionnaire‐Short Form (PDQ‐SF), a self‐report measure of cognitive symptoms. A comprehensive neuropsychological battery was administered as the “gold standard” index of neuropsychological impairment.ResultsRates of neuropsychological impairment were 27% and 15% for the SLE and RA cohorts, respectively. Optimal threshold estimations were derived for 5 screening techniques. The HVLT‐R learning and phonemic fluency indices yielded the greatest sensitivity at 81%. The PDQ‐SF yielded the lowest sensitivity at 52%. All measures were significantly associated with neuropsychological impairment after controlling for relevant sociodemographic covariates and depression.ConclusionThese results suggest that telephone‐administered screening techniques may be useful measures to identify persons with neuropsychological impairment. Specifically, measures of phonemic fluency and verbal learning appeared to be most sensitive and least likely to misclassify impaired individuals as cognitively intact. Self‐reported questionnaires may have relatively decreased sensitivity compared to standardized interviewer‐administered cognitive measures.
Synthesis of polysiloxane‐type multifunctional flame retardant and its application in epoxy systems
Authors: Kang Nianjun , Du Zhongjie , Li Hangquan , Zhang Chen 
Published: December 2011

AbstractPolymethyl(3‐glycidyloxypropyl)siloxane (PMGS) was synthesized as a flame‐retardant additive, which were cocured with diglycidyl ether of bisphenol‐A (DGEBA) using 4,4′‐diaminodiphenylsulfone as a curing agent. The structure of PMGS was confirmed through Fourier transform infrared and 1H‐NMR spectra. The cured products were characterized with dynamic mechanical thermal analysis, thermogravimetric analysis, and oxygen index analyzer. With PMGS incorporated, the cured epoxy resin showed better thermal stability, higher limited oxygen index, and higher char yield. At moderate loading of PMGS, the storage modulus and glass transition temperature of the cured epoxy resin based on neat DGEBA were obviously improved. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Thermal effect of carbamates based polymer on the TiO2 growth
Authors: Shin Jong Wook , Kim Soo Young 
Published: December 2011

AbstractWe investigated the growth of TiO2 on poly((tetrahydropyran‐2‐yl N‐(2‐methacryloxyethyl) carbamate)‐co‐(methyl 4‐(3‐methacryloyloxypropoxy) cinnamate) (THP‐polymer) using thermal heating, octyl isocyanate (OIC), and glutaraldehyde. It is found that TiO2 can be grown on surfaces terminated with NH2 and O groups from aqueous solution. However, TiO2 did not deposit on CH3 terminated surfaces, due to the low surface energy of these surfaces. Fourier transform infrared spectroscopy and thermogravimetric analysis data showed that the THP functional group can be removed and the surface functional group converted to NH2 by heating the material over 180°C. OIC can then be immobilized on the surface after heating, changing the surface functional group from NH2 to CH3. As TiO2 can be deposited from solution on NH2 terminated, but not CH3 terminated surfaces, THP‐polymer can be used to switch the surface properties by thermal activation and subsequent reaction with OIC. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
UV‐radiation induced graft copolymerization of methyl methacrylate onto sodium salt of partially carboxymethylated psyllium
Authors: Dholakia Amit , Jivani Jayesh , Trivedi Jignesh , Patel Kirit , Trivedi Harikrishna 
Published: December 2011

AbstractUV‐radiation induced grafting of methyl methacrylate onto sodium salt of partially carboxymethylated psyllium has been carried out using ceric ammonium nitrate as a photoinitiator in an aqueous medium. The reaction variables including concentrations of initiator, nitric acid, monomer, and amount of the backbone as well as time and temperature have been varied for establishing the optimized reaction conditions for grafting. The influence of these reaction conditions on the grafting yields has been discussed. The overall activation energy of grafting has been calculated. The infrared spectroscopic, thermogravimetric analysis, and scanning electron microscopic techniques have been used for the characterization of graft copolymers. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Adsorption characterization of lead(II) and cadmium(II) on crosslinked carboxymethyl starch
Authors: Chen Yan Xiao , Zhong Ben He , Fang Wei Mao 
Published: December 2011

AbstractThe adsorption of Pb(II) and Cd(II) ions with crosslinked carboxymethyl starch (CCS) was investigated as function of the solution pH, contact time, initial metal‐ion concentration, and temperature. Isotherm studies revealed that the adsorption of metal ions onto CCS better followed the Langmuir isotherm and the Dubinin–Radushkevich isotherm with adsorption maximum capacities of about 80.0 and 47.0 mg/g for Pb(II) and Cd(II) ions, respectively. The mean free energies of adsorption were found to be between 8 and 16 kJ/mol for Pb(II) and Cd(II) ions; this suggested that the adsorption of Pb(II) and Cd(II) ions onto CCS occurred with an ion‐exchange process. For two‐target heavy‐metal ion adsorption, a pseudo‐second‐order model and intraparticle diffusion seem significant in the rate‐controlling step, but the pseudo‐second‐order chemical reaction kinetics provide the best correlation for the experimental data. The enthalpy change for the process was found to be exothermic, and the ΔSθ values were calculated to be negative for the adsorption of Pb(II) and Cd(II) ions onto CCS. Negative free enthalpy change values indicated that the adsorption process was feasible. The studies of the kinetics, isotherm, and thermodynamics indicated that the adsorption of CCS was more effective for Pb(II) ions than for Cd(II) ions. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Effect of blending sequence on the morphology and properties of polyamide 6/EPDM‐g‐MA/epoxy blends
Authors: Wang Qi , Zhu Jiayu , Wang Pan , Li Liping , Yang Qi , Huang Yajiang 
Published: December 2011

AbstractThe ternary blends of polyamide 6/maleated ethylene‐propylene‐diene rubber/epoxy (PA6/EPDM‐g‐MA/EP) were prepared by a twin‐screw extruder with four different blending sequences. With the variation of blending sequence, the ternary blends presented distinct morphology and mechanical properties because of different interactions induced by various reactive orders. The addition of epoxy could increase the viscosity of the PA6 matrix, but a considerably larger size of the dispersed rubber phase was observed while first preblending PA6 with epoxy followed by blending a premix of PA6/EP with EDPM‐g‐MA, which was attested by rheological behaviors and SEM observations. It was probably ascribed to the fact that the great increase of the interfacial tension between the matrix and rubber phase aroused a great coalescence of rubber particles. The presence of epoxy in the rubber phase reduced the rubber's ability to cavitate so that the toughening efficiency of the EPDM‐g‐MA was decreased. The results of mechanical testing revealed that the optimum blending sequence to achieve balanced mechanical properties is blending PA6, EPDM‐g‐MA, and epoxy simultaneously in which the detrimental reactions might be effectively suppressed. In addition, thermal properties were investigated by TG and DSC, and the results showed that there was no distinct difference. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Chronological Change from Face‐On to Edge‐On Ordering of Zinc–Tetraphenylporphyrin at the Phenyloctane–Highly Oriented Pyrolytic Graphite Interface
Authors: Sakano Takeshi , Hasegawa Jun‐ya , Higashiguchi Kenji , Matsuda Kenji 
Published: December 2011

AbstractThe self‐assembled structure of alkoxy‐ and N‐alkylcarbamoyl‐substituted zinc–tetraphenylporphyrin at the liquid–highly oriented pyrolytic graphite (HOPG) interface was observed by using scanning tunneling microscopy. The alkoxy porphyrin showed a phase transition from face‐on to edge‐on ordering. The phase transition requires the close‐packed structure of alkoxy porphyrin. The chronological change of the ordering was traced to show the existence of several types of Ostwald ripening including two‐step phase transition from small edge‐on to face‐on and then further to edge‐on orderings. On the other hand, the N‐alkylcarbamoyl porphyrin showed persistent edge‐on ordering, and the ordering was analyzed by the Moiré pattern. Although the edge‐on ordering is observed only in the nonpolar solvent, the orderings have potential applications in the charge and energy transfer.
Polyelectrolyte‐Functionalized Gold Nanoparticle Scaffold for the Sensing of Heparin and Protamine in Serum
Authors: Dey Ramendra Sundar , Raj C. Retna 
Published: December 2011

AbstractWe describe a shape‐controlled synthesis of polyelectrolyte‐functionalized flowerlike and polyhedral Au nanoparticles and the development of a nanoarchitectured platform for the selective and highly sensitive detection of protamine and heparin by voltammetric, impedimetric, and microgravimetric techniques. The functionalized Au nanoparticles were chemically synthesized in aqueous solution at room temperature in the presence of the polyelectrolyte (either protamine or heparin). The charge on the polyelectrolyte controlled the shape and surface morphology of the nanoparticles. The negatively charged heparin‐functionalized Au nanoparticles have multiple branched flowerlike shapes with an average size of 50 nm, whereas the cationic protamine‐functionalized nanoparticles are of polyhedral shape with an average size of 25 nm. Both flowerlike and polyhedral nanoparticles have (111), (200), (220), and (311) planes of a face‐centered cubic lattice of Au. Voltammetric, impedimetric, and microgravimetric sensing platforms based on functionalized Au nanoparticles have been developed for the sensing of heparin and protamine. The sensing platforms are developed by self‐assembling the functionalized nanoparticles on a thiol‐functionalized three‐dimensional silicate network. The microgravimetric sensing platform shows very high sensitivity and it can detect heparin and protamine at concentrations as low as 0.05 μg mL−1. The selectivity of the sensing platform towards heparin was examined with potential interferents such as hyaluronic acid (HA) and chondroitin‐4‐sulfate (CS). Both HA and CS did not interfere with the measurement of heparin. The practical application of the sensing platform was demonstrated by measuring the concentration of heparin and protamine in human serum samples. The sensing platform could successfully quantify the concentration of heparin and protamine in the real serum samples with excellent recovery. The sensing platform was robust and could be used for repeated measurement without compromising the sensitivity.
The long‐term variability of Vega
Authors: Butkovskaya V. , Plachinda S. , Valyavin G. , Baklanova D. , Lee B.‐C. 
Published: December 2011

AbstractOver the time of 60 years Vega (α Lyrae = HD 172167, A0V) has been generally accepted as a standard star in the nearinfrared, optical, and ultraviolet regions. But is the spectrophotometric standard Vega really non‐variable star? Researchers give very different answers to this question. We aim to search a periodicity in our results of spectropolarimetric study of Vega, namely periodic variations in equivalent width of the spectral lines and longitudinal magnetic field measurements. High‐accuracy spectropolarimetric observations of Vega have been performed during 26 nights from 1997 to 2010 using the Coudé spectrograph of the 2.6‐m Shain reflector at the Crimean Astrophysical Observatory (CrAO, Ukraine) and during 4 nights in 2007 and 2008 using the echelle spectrograph BOES at the Bohyunsan Optical Astronomy Observatory (BOAO, South Korea). The long‐term (year‐to‐year) variability of Vega was confirmed. It was concluded that this variability does not have magnetic nature (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
General magnetic field on the weakly‐active yellow giant Pollux and on the old dwarf star 61 Cyg A
Authors: Baklanova D. , Plachinda S. , Mkrtichian D. , Han I. , Kim K.‐M. 
Published: December 2011

AbstractPollux is yellow giant with known regular surface magnetic field about 1 Gauss. An analysis of the periodic behavior of the magnetic field of Pollux was performed. For this purpose, we used literature data together with spectropolarimetric observations, which were carried out during 10 nights in 2010 at the Crimean Astrophysical Observatory, and spectropolarimetric observations, which were obtained at Bohyunsan Optical Astronomy Observatory during 4 nights in 2007. The radial velocity measurements of Pollux show variations with a period of 592.9 days due to the planetary companion. The rotational period of the Pollux equals to 491.5 days. Improved dipole parameters are presented. The centered dipole gives the angle between spin axis and line of sight, i ∼ 45°, and the angle between the spin and dipole axes, β ∼ 135°. We suppose that a few points that lie outside of the dipole magnetic field curve by more than three errors are the result of the emergence of magnetic unipolar spots on the stellar surface. We discuss the possibility of these events in comparison with solar‐like star 61 Cyg A and the Sun. Numerical simulations of the magnetic geometry lead us to the conclusion that the spots may have an angular radius of ∼1.5° with the magnetic intensity ∼3000 G. Such active regions can be formed at the same latitudes as on the Sun near the 40° from the equator (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Line profile variability and magnetic fields of Wolf‐Rayet stars: WR 135 and WR 136
Authors: Kholtygin A.F. , Fabrika S.N. , Rusomarov N. , Hamann W.‐R. , Kudryavtsev D.O. , Oskinova L.M. , Chountonov G.A. 
Published: December 2011

AbstractWe have obtained spectropolarimetric observations of two Wolf‐Rayet stars, WR 135 (WC8) and W R136 (WN6), with the 6‐m Russian telescope in July 2009 and July 2010. We have studied the He II 5412 Å line region, which contains also the C IV 5469 Å line (for WR 135 only). Our goals were to investigate the rapid line‐profile variability (LPV) in WR star spectra and to search for magnetic fields. We find small amplitude emission peaks moving from the center of He II line to its wings during the night in spectra of both stars. These emission peaks are likely a signature of accelerating clumps in the stellar wind. We obtained upper limits of the magnetic field strength: ≈200 G for WR 135 and ≈50 G for WR 136 (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spectroscopic variability and magnetic fields of HgMn stars
Authors: Hubrig S. , González J.F. , Ilyin I. , Korhonen H. , Savanov I.S. , Dall T. , Schöller M. , Cowley C.R. , Briquet M. , Arlt R. 
Published: December 2011

AbstractThe discovery of exotic abundances, chemical inhomogeneities, and weak magnetic fields on the surface of late B‐type primaries in spectroscopic binaries has important implications not only for our understanding of the formation mechanisms of stars with Hg and Mn peculiarities themselves, but also for the general understanding of B‐type star formation in binary systems. The origin of the abundance anomalies observed in late B‐type stars with HgMn peculiarity is still poorly understood. The connection between HgMn peculiarity and membership in binary and multiple systems is supported by our observations during the last decade. The important result achieved in our studies of a large sample of HgMn stars is the finding that most HgMn stars exhibit spectral variability of various chemical elements, proving that the presence of an inhomogeneous distribution on the surface of these stars is a rather common characteristic and not a rare phenomenon. Further, in the studied systems, we found that all components are chemically peculiar with different abundance patterns. Generally, He and Si variable Bp stars possess large‐scale organised magnetic fields that in many cases appear to occur essentially in the form of a single large dipole located close to the centre of the star. The presence of magnetic fields in the atmospheres of HgMn stars has been demonstrated in several studies. In addition to the measurements of longitudinal and quadratic magnetic fields, this work also showed evidence for a relative magnetic intensification of Fe II lines produced by different magnetic desaturations induced by different Zeeman‐split components (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
X‐ray emission from massive stars with magnetic fields
Authors: Oskinova L.M. , Hamann W.‐R. , Cassinelli J.P. , Brown J.C. , Todt H. 
Published: December 2011

AbstractWe investigate the connections between the magnetic fields and the X‐ray emission from massive stars. Our study shows that the X‐ray properties of known strongly magnetic stars are diverse: while some comply to the predictions of the magnetically confined wind model, others do not. We conclude that strong, hard, and variable X‐ray emission may be a sufficient attribute of magnetic massive stars, but it is not a necessary one. We address the general properties of X‐ray emission from “normal” massive stars, especially the long standing mystery about the correlations between the parameters of X‐ray emission and fundamental stellar properties. The recent development in stellar structure modeling shows that small‐scale surface magnetic fields may be common. We suggest a “hybrid” scenario which could explain the X‐ray emission from massive stars by a combination of magnetic mechanisms on the surface and shocks in the stellar wind. The magnetic mechanisms and the wind shocks are triggered by convective motions in sub‐photospheric layers. This scenario opens the door for a natural explanation of the well established correlation between bolometric and X‐ray luminosities (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Polar branches of stellar activity waves: Dynamo models
Authors: Sokoloff D.D. , Lanza A.F. , Moss D.L. , Tarbeeva S.M. 
Published: December 2011

AbstractStellar activity data provide evidence that some activity wave branches propagate polewards rather than equatorwards (the latter being the solar case). This evidence is especially pronounced for the well‐observed subgiant HR 1099. For this star, the polar branch seems to coexist with an equatorward branch which propagates through more or less the same latitudinal domain. Stellar dynamo theory allows poleward propagating dynamo waves for certain governing parameters. We discuss the importance of the choice of dynamo governing parameters in fitting the phenomenology of HR 1099 (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)