bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polylactide and hybrid silicasol nanoparticle‐based composites
Authors: Zhiltsov Andrey , Gritsenko Oleg , Kazakova Valentina , Gorbatsevitch Olga , Bessonova Natalia , Askadskii Andrey , Serenko Olga , Muzafarov Aziz 
Published: January 2015

ABSTRACTThe effects of the chemical nature and size of the hybrid nanoparticle external layer on the structures and properties of polylactide composites are investigated. Polylactide is used as the matrix polymer, and molecular silicasol particles with γ‐hydroxypropylic, (methoxyacetyl)oxy, and acetoxy surface groups serve as fillers. A preliminary assessment of the thermodynamic compatibility of polylactide with the surface groups of molecular silicasols is performed. The hydrophilic shells of the silicasols prevent their aggregation in the bulk of the nanocomposite. It shows variations in the chemical structure of the surface layer of the nanoparticles as well as their sizes and concentration make it possible to conduct a controlled change of the characteristics of the composites, particularly to eliminate one of the drawbacks of PLA, the low speed of its crystallization. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41894.
Pervaporation separation of ethanol/water mixture using modified zeolite filled PDMS membranes
Authors: Ji Lingyun , Shi Baoli , Wang Lili 
Published: January 2015

ABSTRACTIn this article, the composite polydimethylsiloxane (PDMS) membranes supported by cellulose acetate (CA) microfiltration membrane were successfully prepared by adding modified zeolite particles with a silane coupling agent, NH3–C3H6–Si(OC2H5)3. The sorption and diffusion behaviors of ethanol and water in the films were studied. The results showed that with the increase in the modified zeolite content, the solubility selectivity increased, but the diffusion selectivity first increased, then decreased. The effects of modified zeolite content and feed temperature on the pervaporation performance of the composite membranes in 10 wt % ethanol/water mixture were also investigated. When modified zeolite loading was 20 wt %, for 10 wt % ethanol/water mixture at 40°C, the permeate flux was 348.7 g·m−2·h−1, the separation factor was 14.1, and the permeate separate index was 4568, respectively. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41897.
Effect of ethyleneglycol dimethacrylate crosslinker on the performance of core‐double shell structure poly(vinyl acetate‐butyl acrylate) emulsion
Authors: Gang Li , Ting Wang , Maofang Huang , Tianming Gao , Xin Fu 
Published: January 2015

ABSTRACTCore‐double shell structure poly(vinyl acetate‐butyl acrylate) emulsion was prepared by semicontinuous emulsion polymerization, and the effects of ethyleneglycol dimethacrylate crosslinker (EGDMA) on the emulsion particle structure and film performance were studied systematically. The emulsion particles' structure was characterized by transmission electron microscopy and Fourier transform infrared spectroscopy, and the particle size and distribution were characterized by Zeta potential—particle analyzer, as well as analysis of the film mechanical properties, water resistance, thermal properties, and so on. The results show that, when 0.1 and 0.5% EGDMA were added to the inner‐shell and outer‐shell reaction stage under the core‐double shell P(VAc‐BA) emulsion preparation process, respectively, it led to a more clear core‐double shell structure and a larger particle size (about 500–800 nm) of emulsion particles, and the comprehensive performance of the P(VAc‐BA) emulsion showed better. This work provided some insight into modifying the surface properties of the emulsion particles, which may expand the application field of the emulsion. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41899.
Preparation and characterization of graft copolymer from dealkaline lignin and styrene
Authors: Li Haifeng , Zhang Qinsheng , Gao Ping , Wang Lailai 
Published: January 2015

ABSTRACTGraft copolymerization of styrene onto dealkaline lignin by ferrous chloride and hydrogen peroxide coinitiator has been achieved successfully. The influence of temperature and reaction time as well as the amount of the styrene monomer, initiator, and catalyst on the grafting copolymerization was investigated. The optimum reaction conditions were determined as follows: c (styrene) = 20.00 mmol, c (H2O2) = 5.00 mmol, c (FeCl2) = 0.10 mmol, T = 30°C and t = 48 h. The optimum yield (Y), total conversion (TC), grafting efficiency (GE), and degree grafted (DG) values were 96.6, 96.3, 59.5, and 53.7%, respectively. The copolymer of lignin grafted PS was separated and characterized by elemental analysis, differential scanning calorimetry, Fourier transform infrared, thermogravimetry analysis, field emission‐scanning electron microscopy, gel permeation chromatography, and nuclear magnetic resonance. It was demonstrated that the solubility what the copolymer exhibited turned out to be the very reverse of the original lignin. The surface properties and structure of lignin were completely changed after grafting copolymerization. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41900.
Rhodium/Chiral Diene‐Catalyzed Asymmetric 1,4‐Addition of Arylboronic Acids to Chromones: A Highly Enantioselective Pathway for Accessing Chiral Flavanones
Authors: He Qijie , So Chau Ming , Bian Zhaoxiang , Hayashi Tamio , Wang Jun 
Published: January 2015

AbstractChromone has been noted to be one of the most challenging substrates in the asymmetric 1,4‐addition of α,β‐unsaturated carbonyl compounds. By employing the rhodium complex associated with a chiral diene ligand, (R,R)‐Ph‐bod*, the 1,4‐addition of a variety of arylboronic acids was realized to give high yields of the corresponding flavanones with excellent enantioselectivities (≥97 % ee, 99 % ee for most substrates). Ring‐opening side products, which would lead to erosion of product enantioselectivity, were not observed under the stated reaction conditions.
Solid‐state synthesis and luminescent properties of yellow‐emitting phosphor NaY(MoO4)2:Dy3+ for white light‐emitting diodes
Authors: Wang Zhijun , Li Panlai , Guo Qinglin , Yang Zhiping 
Published: January 2015

AbstractA yellow‐emitting phosphor NaY(MoO4)2:Dy3+ was synthesized using a solid‐state reaction at 550 °C for 4 h, and its luminescent properties were investigated. Its phase formation was studied using X‐ray powder diffraction analysis, and there were no crystalline phases other than NaY(MoO4)2. NaY(MoO4)2:Dy3+ produced yellow emission under 386 or 453 nm excitation, and the prominent luminescence was yellow (575 nm) due to the 4 F9/2→6H13/2 transition of Dy3+. For the 575 nm emission, the excitation spectrum had one broad band and some narrow peaks; the peaks were located at 290, 351, 365, 386, 426, 453 and 474 nm. Emission intensities were influenced by the Dy3+ doping content and a concentration quenching effect was observed; the phenomenon was also proved by the decay curves. Moreover, the Commission International de I'Eclairage chromaticity coordinates of NaY(MoO4)2:Dy3+ showed similar values at different Dy3+ concentrations, and were located in the yellow region. Copyright © 2015 John Wiley & Sons, Ltd.
Biosynthetic Labeling and Two‐Color Imaging of Phospholipids in Cells
Authors: Jao Cindy Y. , Roth Mary , Welti Ruth , Salic Adrian 
Published: January 2015

AbstractPhospholipids with a choline head group are abundant components of all biological membranes, performing critical functions in cellular structure, metabolism, and signaling. In spite of their importance, our ability to visualize choline phospholipids in vivo remains very limited. We present a simple and robust chemical strategy to image choline phospholipids, based on the metabolic incorporation of azidocholine analogues, that accurately reflects the normal biosynthetic incorporation of choline into cellular phospholipids. Azidocholine‐labeled phospholipids can be imaged in cells with high sensitivity and resolution, following derivatization with fluorophores, by bio‐orthogonal chemical reactions compatible with live‐cell imaging. We used this method to visualize the subcellular localization of choline phospholipids. We also demonstrate that double metabolic labeling with azidocholine and propargylcholine allows sensitive two‐color imaging of choline phospholipids. Our method represents a powerful approach to directly image phospholipids, and to study their dynamics in cells and tissues.
The Role of Metal Halides in Enhancing the Dehydration of Xylose to Furfural
Authors: Enslow Kristopher R. , Bell Alexis T. 
Published: January 2015

AbstractThe dehydration of xylose yields furfural, a product of considerable value as both a commodity chemical and a platform for producing a variety of fuels. When xylose is dehydrated in aqueous solution in the presence of a Brønsted acid catalyst, humins are formed via complex side processes that ultimately result in a loss in the yield of furfural. Such degradative processes can be minimized via the in situ extraction of furfural into an organic solvent. The partitioning of furfural from water into a given extracting solvent can be enhanced by the addition of salt to the aqueous phase, a process that increases the thermodynamic activity of furfural in water. Although the thermodynamics of using salts to improve liquid–liquid extraction are well studied, their impact on the kinetics of xylose dehydration catalyzed by a Brønsted acid are not. The aim of the present study was to understand how metal halide salts affect the mechanism and kinetics of xylose dehydration in aqueous solution. We found that the rate of xylose consumption is affected by both the nature of the salt cation and anion, increasing in the order no salt<K+<Na+<Li+ and no salt<Cl−<Br−<I−. Furfural selectivity increases similarly with respect to metal cations, but in the order no salt<I−<Br−<Cl− for halide anions. Multinuclear NMR was used to identify the interactions of cations and anions with xylose and to develop a model for explaining xylose‐metal halide and water‐metal halide interactions. The results of these experiments coupled with 18O‐labeling experiments indicate that xylose dehydration is initiated by protonation at the C1OH and C2OH sites, with halide anions acting to stabilize critical intermediates. The means by which metal halides affect the formation of humins was also investigated, and the role of cations and anions in affecting the selectivity to humins is discussed.
Extended Debye–Hückel Theory for Studying the Electrostatic Solvation Energy
Authors: Xiao Tiejun 
Published: January 2015

AbstractThe electrostatic part of the solvation energy has been studied by using extended Debye–Hückel (DH) theories. Specifically, our molecular Debye–Hückel theory [J. Chem. Phys. 2011, 135, 104104] and its simplified version, an energy‐scaled Debye–Hückel theory, were applied to electrolytes with strong electrostatic coupling. Our theories provide a practical methodology for calculating the electrostatic solvation free energies, and the accuracy was verified for atomic and diatomic charged solutes.
Sexual segregation in North American elk: the role of density dependence
Authors: Stewart Kelley M. , Walsh Danielle R. , Kie John G. , Dick Brian L. , Bowyer R. Terry 
Published: January 2015

AbstractWe investigated how density‐dependent processes and subsequent variation in nutritional condition of individuals influenced both timing and duration of sexual segregation and selection of resources. During 1999–2001, we experimentally created two population densities of North American elk (Cervus elaphus), a high‐density population at 20 elk/km2, and a low‐density population at 4 elk/km2 to test hypotheses relative to timing and duration of sexual segregation and variation in selection of resources. We used multi‐response permutation procedures to investigate patterns of sexual segregation, and resource selection functions to document differences in selection of resources by individuals in high‐ and low‐density populations during sexual segregation and aggregation. The duration of sexual segregation was 2 months longer in the high‐density population and likely was influenced by individuals in poorer nutritional condition, which corresponded with later conception and parturition, than at low density. Males and females in the high‐density population overlapped in selection of resources to a greater extent than in the low‐density population, probably resulting from density‐dependent effects of increased intraspecific competition and lower availability of resources.
Comparison of different irrigation activation techniques on smear layer removal: An in vitro study
Authors: Akyuz Ekim Sefika Nur , Erdemir Ali 
Published: January 2015

ABSTRACTThe purpose of this study was to evaluate the efficiency of different irrigation activation techniques on smear layer removal. About 80 single‐rooted human maxillary central teeth were decoronated to a standardized length.The samples were prepared by using ProTaper system to size F4 and divided into eight equal groups (n = 10) according to the final irrigation activation technique; distilled water was used as an irrigant in Group 1. The other groups were treated with 2.5% NaOCl and 17% EDTA, respectively. Conventional syringe irrigation (CSI) was used in Group 2. Irrigation solutions were activated using passive ultrasonic irrigation (PUI, Group 3), EndoVac apical negative pressure (ANP, Group 4), diode laser (Group 5), Nd:YAG laser (Group 6), Er:YAG laser (Group 7), and Er:YAG laser using with photon‐induced photoacoustic streaming (PIPS™, Group 8). Teeth were split longitudinally and subjected to scanning electron microscope (SEM). PIPS showed the best removal of smear layer when compared with PUI, ANP, Nd:YAG, and Er:YAG, but the difference was not statistically significant (P > 0.05). Smear layer scores obtained with PIPS technique were statistically significant different from those of obtained with control, CSI and diode laser groups (P < 0.05). All experimental irrigation techniques except ANP and diode laser removed smear layer more effectively at the coronal and middle levels compared to the apical level (P < 0.05). Irrigation activated/delivered techniques except diode laser have a positive effect on removing of smear layer. Microsc. Res. Tech. 78:230–239, 2015. © 2015 Wiley Periodicals, Inc.
A new methodology for identifying daughter cyclogenesis: application for the Mediterranean Basin
Authors: Ziv Baruch , Harpaz Tzvi , Saaroni Hadas , Blender Richard 
Published: January 2015

ABSTRACTThis study is the first one to objectively identify ‘parent–daughter’ relationships between cyclones and to apply it to Mediterranean cyclones (MCs). The methodology includes cyclone detection, tracking and mapping the area of influence of a cyclone; here daughter cyclones are expected to be found. Cyclone detection and tracking is based on standard algorithms, which were modified to cope with irregularities in intensity and trajectory shapes of MCs. We have developed our own algorithm for mapping cyclones' area of influence. Application of our methodology to the ERA‐Interim data for 33 mid‐winter seasons identified parents for 97.5% of the MCs. While previous studies claimed that most MC parents are situated over Europe, this study found the majority of MCs' parents (56%) positioned over the Mediterranean itself. This disagreement stems from the fine spatial resolution used here (0.75° × 0.75°), which enabled uncovering smaller cyclones than noticed previously, thus revealing earlier stages of cyclogenesis. The parenthood analysis identified two main types of cyclogenesis within the Mediterranean; one driven by parent MCs, the other driven by Atlantic or European cyclones. The latter is manifested either by directly generating a new MC or by intensifying existing weak MCs. Cyclone generations were explored through backtracking chains of parents down to the ninth generation, the longest chain found. The results indicate that the primary source of MCs is the Atlantic (2/3 of the MCs) and then Equatorial Africa and the Red Sea (1/3). The results also imply that although native MCs owe their existence to the Atlantic‐European cyclone track, regional cyclogenetic effects, such as topographic, thermal and baroclinic, are even more influential. The innovative methodology for objective identification of cyclone parents can be used to characterize cyclogenetic scenarios, in particular away from main storm tracks and over complex terrain.
Preparation and characterization of poly(lactic acid)/poly(methyl methacrylate) blend tablets for application in quantitative analysis by micro Raman spectroscopy
Authors: Vano‐Herrera Kelim , Misiun Anna , Vogt Carla 
Published: January 2015

Poly(lactic acid) (PLA) is a biodegradable polymer that has a variety of applications, one of which is as biomaterial in surgery or as functional layers on implants, due to its compatibility with living tissue.This paper reports the possibilities of quantification of poly(lactic acid) (PLA) in a polymer matrix such as poly(methyl methacrylate) (PMMA) by micro Raman spectroscopy (MRS). Blends of amorphous poly(DL‐lactic acid) with poly(methyl methacrylate) were prepared by the procedure of dissolution/precipitation. Thermal properties of the blends such as the glass transition temperature (Tg) were characterized by differential scanning calorimetry (DSC). The PLA/PMMA blends exhibited only a single glass transition region, indicating that this system is miscible. The PLA/PMMA system obeys the Gordon–Taylor equation (Tg versus PLA content). Various concentration ratios of PLA blends were prepared to use as a basis for quantitative analysis by MRS. Intensities of the characteristic bands at 813 cm−1 (νCOC of PMMA) and 873 cm−1 (νC―COO of PLA) were used for the calculation. The calibration graph showed a good linear correlation with an R2 value of 0.9985. On the basis of the calibration curve obtained, the determined content of several PLA/PMMA blends was in good agreement when compared with nominal contents. The limit of detection (LOD) and quantification (LOQ) were calculated by the calibration data set as signal‐to‐noise method. The relative standard deviation of this method was lower than 10% and the accuracy better than 4%. This study demonstrated that Raman spectroscopy provides an alternative non destructive method for quantitative analysis of PLA in a PMMA matrix. Copyright © 2015 John Wiley & Sons, Ltd.
Effect of C1‐Esterase‐inhibitor in angiotensin‐converting enzyme inhibitor‐induced angioedema
Authors: Greve Jens , Bas Murat , Hoffmann Thomas K. , Schuler Patrick J. , Weller Patrick , Kojda Georg , Strassen Ulrich 
Published: January 2015

Objectives/HypothesisThe study objective was to generate pilot data to evaluate the effectiveness and safety of C1‐esterase‐inhibitor concentrate (C1‐INH) compared to standard treatment in patients with angiotensin‐converting enzyme inhibitor (ACEi)‐induced angioedema affecting the upper aerodigestive tract.Study DesignProof‐of‐concept case series with historical control.MethodsAdult patients with angioedema in the upper aerodigestive tract presenting to the emergency department were included. After establishing the diagnosis of ACEi‐induced angioedema based on patient history and thorough clinical examination, all patients were administered 1,000 international units (IU) of C1‐INH intravenously. A historical control group consisting of adult patients with ACEi‐induced angioedema who had been treated with intravenous corticosteroids and antihistamines at the same institution over the past 8 years was used for comparison. The most important parameters assessed were the time to complete resolution of symptoms and the need for intubation or tracheotomy.ResultsTen patients were included in the C1‐INH group and 47 in the corticosteroid/antihistamine group. The time to complete resolution of symptoms was considerably longer in the historical control group (33.1 ± 19.4 hours) than in the C1‐INH group (10.1 ± 3.0 hours). No intubation or tracheotomy was needed in the C1‐INH group (0/10 patients), whereas three out of the 47 historical controls required tracheotomy and two were intubated (5/47).ConclusionThe results suggest a role for C1‐INH as an effective and safe therapeutic option in patients with ACEi‐induced angioedema, which needs to be confirmed by further larger and double‐blinded studies.Level of Evidence4. Laryngoscope, 125:E198–E202, 2015
An atomistic insight into light‐sensitive polymers with methylstilbene building blocks
Authors: Bandeira Nuno A. G. , Tylkowski Bartosz , Bogdanowicz Krzysztof Artur , Giamberini Marta , Bo Carles 
Published: January 2015

AbstractControlled release of photosensitive systems is widely studied because of its numerous applications. However, just a few descriptions of the mechanism of this phenomenon have been reported. The aim of this study was to investigate the behaviour of a real system based on light‐sensitive α‐methylstilbene‐based copolyester microcapsules with vanillin as an upload under UV irradiation. For this purpose we aimed to elucidate some of the structural features of the chains by means of quantum chemical calculations applying periodic boundary conditions. Additionally, the excitation energy of an approximated model was used to verify the influence of large size and various functionalities of attached groups on the system. From the optimized structure of trans and cis isomers, it was proved that trans‐to‐cis isomerization can be responsible for a main chain length reduction by 20% in comparison to the initial state, thus confirming the experimental findings. Moreover, the major influence of double bonds on photoactivity of the system was justified by comparison of the calculated UV‐visible spectra of both forms with empirically obtained data which were in good agreement. © 2015 Society of Chemical Industry
Synthesis of polymers possessing tetraphenylethylene units by three‐component coupling reactions of poly(p‐phenylene ethynylene) derivative with aryl halides and phenylboronic acid
Authors: Suto Takeru , Nishiyama Hiroki , Inagi Shinsuke , Tomita Ikuyoshi 
Published: January 2015

ABSTRACTA derivative of poly(p‐phenylene ethynylene) was subjected to the palladium‐catalyzed three‐component coupling reactions with aryl halides and phenylboronic acid to obtain polymers having tetrasubstituted cis‐vinylene units. For example, 69% of the acetylene units in the prepolymer were converted to cis‐vinylene (i.e., tetrasubstituted cis‐vinylene) units using iodobenzene and phenylboronic acid (5 equiv each with respect to acetylene units). In the UV–vis absorption spectra of the resulting polymers, clear hypsochromic shifts of the absorption maxima were observed, while bathochromic shifts and suppression of the efficiency were observed in their photoluminescence spectra. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 787–791