bluuebunny/crossref_metadata_2025 huggingface dataset:
One‐Pot Synthesis of Luminescent Polymer‐Nanoparticle Composites from Task‐Specific Ionic Liquids
Authors: Campbell Paul S. , Lorbeer Chantal , Cybinska Joanna , Mudring Anja‐Verena
Published: January 2013

A multifunctional polymerizable ionic liquid, diallyldimethylammonium tetrafluoroborate (DADMA BF4), is used in a one‐pot synthesis of novel luminescent polymer‐nanoparticle composites. First, small monodisperse lanthanide fluoride nanoparticles are formed by microwave irradiation in the presence of Ln(OAc)3·xH2O (Ln = Gd, Eu, Tb; OAc = acetate) in the ionic liquid. The nanoparticles can be precipitated for structural characterization or kept in the solution, which yields after irradition by high intensity UV light colorless, processable polymer materials with good photophysical properties. Both green‐emitting Tb‐containing and red‐emitting Eu‐containing IL‐ polymers are described.
Magnetoplasmonics: Combining Magnetic and Plasmonic Functionalities
Authors: Armelles Gaspar , Cebollada Alfonso , García‐Martín Antonio , González María Ujué
Published: January 2013

Nanosystems with combined magnetic and plasmonic functionalities have in recent years become an active topic of research. By an adequate internal architecture of the constituting components, the magneto‐optical activity of these systems can be greatly increased due to the electromagnetic field enhancement associated with the plasmon resonance. Simultaneously, the magnetic functionality permits the control of the plasmonic properties by an external magnetic field, which allows the development of active plasmonic devices. These materials find applications in, for example, gas and biosensing areas, and in integrated photonic devices for telecommunications. In the present work the state of the art and current understanding of the phenomenology associated with magnetoplasmonic structures where magnetism and plasmonics are intertwined are reviewed.
Fused Heteroaromatic Organic Compounds for High‐Power Electrodes of Rechargeable Lithium Batteries
Authors: Liang Yanliang , Zhang Peng , Yang Siqi , Tao Zhanliang , Chen Jun
Published: January 2013

Organic redox compounds are emerging electrode materials for rechargeable lithium batteries. However, their electrically insulating nature plagues efficient charge transport within the electroactive bulk. Alternative to the popular solution of elaborating nanocomposite materials, herein we report on a molecular‐level engineering strategy towards high‐power organic electrode materials with multi‐electron reactions. Systematic comparisons of anthraquinone analogues incorporating fused heteroaromatic structures as cathode materials in rechargeable lithium batteries reveal that the judicious incorporation of heteroaromatics improves the cell performance in terms of specific gravimetric capacity, working potential, rate capability, and cyclability. Combination studies with morphological observation, electrochemical impedance characterization, and theoretical modeling provide insight into the advantage of heteroaromatic building blocks. In particular, benzofuro[5,6‐b]furan‐4,8‐dione (BFFD) bearing furan moeities shows a reversible capacity of 181 mAh g−1 when charged/discharged at 100C, corresponding to a power density of 29.8 kW kg−1. These results have pointed to a general design route of high‐rate organic electrode materials by rational functionalization of redox compounds with appropriate heteroaromatic units as versatile structural tools.
Modeling and control of protein crystal shape and size in batch crystallization
Authors: Kwon Joseph Sang‐Il , Nayhouse Michael , Christofides Panagiotis D. , Orkoulas Gerassimos
Published: January 2013

In this work, the modeling and control of a batch crystallization process used to produce tetragonal hen egg white lysozyme crystals are studied. Two processes are considered, crystal nucleation and growth. Crystal nucleation rates are obtained from previous experiments. The growth of each crystal progresses via kinetic Monte Carlo simulations comprising of adsorption, desorption, and migration on the (110) and (101) faces. The expressions of the rate equations are similar to Durbin and Feher. To control the nucleation and growth of the protein crystals and produce a crystal population with desired shape and size, a model predictive control (MPC) strategy is implemented. Specifically, the steady‐state growth rates for the (110) and (101) faces are computed and their ratio is expressed in terms of the temperature and protein concentration via a nonlinear algebraic equation. The MPC method is shown to successfully regulate both the crystal size and shape distributions to different set‐point values. © 2013 American Institute of Chemical Engineers AIChE J, 59: 2317–2327, 2013
Simultaneous process synthesis and control design under uncertainty: A worst‐case performance approach
Authors: Sánchez‐Sánchez Kelvyn , Ricardez‐Sandoval Luis
Published: January 2013

A new methodology that includes process synthesis and control structure decisions for the optimal process and control design of dynamic systems under uncertainty is presented. The method integrates dynamic flexibility and dynamic feasibility in a single optimization formulation, thus, reducing the costs to assess the optimal design. A robust stability test is also included in the proposed method to ensure that the optimal design is stable in the presence of magnitude‐bounded perturbations. Since disturbances are treated as stochastic time‐discrete unmeasured inputs, the optimal process synthesis and control design specified by this method remains feasible and stable in the presence of the most critical realizations in the disturbances. The proposed methodology has been applied to simultaneously design and control a system of CSTRs and a ternary distillation column. A study on the computational costs associated with this method is presented and compared to that required by a dynamic optimization‐based scheme. © 2013 American Institute of Chemical Engineers AIChE J, 59: 2497–2514, 2013
PDA measurements in a three‐phase bubble column
Authors: Gan Z. W. , Yu S. C. M. , Law A. W. K.
Published: January 2013

Phase Doppler anemometry was used to quantify the flow characteristic of a three phases (liquid, solid, and bubbles) cylindrical bubble column driven by a point air source made of a 30‐mm diameter perforated air stone centrally mounted at the bottom. The cylindrical bubble column had an inner diameter of 152 mm and was filled with liquid up to 1 m above the point source. Acrylic beads with a nominal diameter of 3 mm were used as the solid phase. To match the density of the solid phase which was 1.05 kg/m3, the liquid density was raised to about 1.0485 kg/m3 by added salt. The bubble diameters generated were within the range of 600–2400 µm. The detailed turbulent characteristics of the liquid‐phase velocity, bubble diameter, bubble velocity, and solid velocity were measured at three different air rates, namely 0.4, 0.8, and 1.2 L/min (corresponding to average gas volume fraction of 0.0084, 0.0168, and 0.0258, respectively) for the homogeneous bubble column regime. With the addition of the solid phase, the flow field was found to be relatively steady compared to the two‐phase column referencing the probability density functions for both the liquid and bubble velocities. An analysis based on the determination of the drag forces and transversal lift forces was performed to examine the flow stability in the three‐phase bubble column. The analysis illustrated that how the added solid phase effectively stabilized the flow field to achieve a steady circulation in the bubble column and a generalized criterion for the flow stability in the three‐phase bubble column was derived. Further investigation for the transition and the heterogeneous bubble column regime with air rates at 2.0 and 4.0 L/min shown that this criterion can also be used as a general prediction of flow stability in this three‐phase bubble column. © 2013 American Institute of Chemical Engineers AIChE J, 59: 2286–2307, 2013
Formaldehyde in the Ambient Atmosphere: From an Indoor Pollutant to an Outdoor Pollutant?
Authors: Salthammer Tunga
Published: January 2013

Formaldehyde has been discussed as a typical indoor pollutant for decades. Legal requirements and ever‐lower limits for formaldehyde in indoor air have led to a continual reduction in the amount of formaldehyde released from furniture, building materials, and household products over many years. Slowly, and without much attention from research on indoor air, a change of paradigm is taking place, however. Today, the formaldehyde concentrations in outdoor air, particularly in polluted urban areas, sometimes already reach indoor levels. This is largely a result of photochemical processes and the use of biofuels. In the medium term, this development might have consequences for the way buildings are ventilated and lead to a change in the way we evaluate human exposure.
Effect of a chain extender on the rheological and mechanical properties of biodegradable poly(lactic acid)/poly[(butylene succinate)‐co‐adipate] blends
Authors: Eslami Hassan , Kamal Musa R.
Published: January 2013

Biodegradable polymer blends based on poly(lactic acid) (PLA) and poly[(butylene succinate)‐co‐adipate] (PBSA) were prepared with a laboratory internal mixer. An epoxy‐based, multifunctional chain extender was used to enhance the melt strength of the blends. The morphology of the blends was observed with field emission scanning electron microscopy. The elongational viscosities of the blends, with and without chain extender, were measured with a Sentmanat extensional rheometer universal testing platform. The blends with chain extender exhibited strong strain‐hardening behavior, whereas the blends without chain extender exhibited only weak strain‐hardening behavior. Measurements of the linear viscoelastic properties of the melts suggested that the chain extender promoted the development of chain branching. The results show that PBSA contributed to significant improvements in the ductility of the PLA/PBSA blends, whereas the chain extender did not have a significant effect on the elastic modulus and strain at break of the blends. The combined blending of PLA with PBSA and the incorporation of the chain extender imparted both ductility and melt strength to the system. Thus, such an approach yields a system with enhanced performance and processability. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Effect of hydrolysis and denaturation of wheat gluten on adhesive bond strength of wood joints
Authors: D'Amico Stefano , Müller Ulrich , Berghofer Emmerich
Published: January 2013

In this study the adhesive bond strength of different wheat gluten modifications and the relationship between molecular weight and adhesive strength was examined. Guanidine hydrochloride and sodium hydroxide were used as denaturation and dispersing agent. Additionally wheat proteins were hydrolyzed by alkaline conditions and enzymes. Effects of different treatments were observed by viscosity measurements and gel electrophoresis. Wood lap joints were prepared with modified proteins and tensile shear strength was tested under dry and wet conditions. In situ hardening of different formulations was analyzed by means of DMA with two‐layered specimens in a three‐point bending test set‐up. Higher solubility had no positive effect on dry bonding strength and wet bonding strength was even reduced. Depending on the degree of hydrolysis, significant improvement of adhesive bond strength was observed. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Self‐healing supramolecular elastomers based on the multi‐hydrogen bonding of low‐molecular polydimethylsiloxanes: Synthesis and characterization
Authors: Zhang Anqiang , Yang Lin , Lin Yaling , Yan Lishan , Lu Hecheng , Wang Lianshi
Published: January 2013

Novel self‐healing supramolecular elastomers based on polydimethylsiloxanes (SESi) were synthesized from a mixture of polydimethylsiloxanes derivers with single, di‐, or tri‐carboxylic acid groups (PDMS–COOHx, where x = 1, 2, and 3, respectively), diethylene triamine, and urea with a two‐stage procedure. The reactions and the final products were tracked, characterized, and confirmed by Fourier transform infrared spectroscopy, 1H‐NMR, differential scanning calorimetry, dynamic mechanical analysis, and gel permeation chromatography. Compared with a supramolecular rubber based on dimer acid (reported previously) with a similar synthesis procedure, the SESi showed a lower glass‐transition temperature of about −113°C for the softer chain of polydimethylsiloxane and showed real rubberlike elastic behavior and self‐healing properties at room temperature or even lower temperatures. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Tangible plasticization/filler effects of sodium salts of dimer acids on the mechanical properties of styrene ionomers
Authors: Ko Kwang‐Hwan , Park Hye Ryeon , Kim Joon‐Seop , Kim Young‐Wun
Published: January 2013

The effects of the presence of dimer acid (DA) molecules in Na‐sulfonated polystyrene (PSSNa) and poly(styrene‐co Na‐methacrylate) (PSMANa) ionomers on the ionomer properties were investigated using a dynamic mechanical analysis technique. The DA decreased the matrix and cluster Tgs of PSSNa ionomer without changing the ionic modulus, suggesting that the DA resided both in the matrix and cluster regions of PSSNa ionomer and acted mainly as a plasticizer. On the other hand, the DA decreased the cluster Tg of PSMANa ionomer, without changing the matrix Tg, and also increased the ionic modulus, implying that the DA behaved like plasticizer only for the cluster regions. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Isothermal crystallization and spherulite growth behavior of stereo multiblock poly(lactic acid)s: Effects of block length
Authors: Rahaman Md. Hafezur , Tsuji Hideto
Published: January 2013

Stereo multiblock poly(lactic acid)s (PLA)s and stereo diblock poly(lactic acid) (DB) with a wide variety of block length of 15.4–61.9 lactyl units are synthesized, and the effects of block length sequence on crystallization and spherulite growth behavior are investigated at different crystallization temperatures, in comparison with neat poly(L‐lactide) (PLLA), poly(D‐lactide) (PDLA), and PLLA/PDLA blend. Only stereocomplex crystallites as crystalline species are formed in the stereo multiblock PLAs and DB, irrespective of block length and crystallization temperature. The maximum crystallinities (33–61%), maximum radial growth rate of spherulites (0.7–56.7 μm min−1), and equilibrium melting temperatures (182.0–216.5°C) increased with increasing block length but are less than those of PLLA/PDLA blend (67 %, 122.5 μm min−1, and 246.0°C). The spherulite growth rates and overall crystallization rates of the stereo multiblock PLAs and DB increased with increasing block length and are lower than that of PLLA/PDLA blend. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Mechanical behavior, microstructure and thermooxidation properties of sequentially crosslinked ultrahigh molecular weight polyethylenes
Authors: Ríos Ricardo , Puértolas José Antonio , Martínez‐Nogués Vanesa , Martínez‐Morlanes María José , Pascual Francisco Javier , Cegoñino José , Medel Francisco Javier
Published: January 2013

The aim of this study was to explore the impact of the sequential irradiation and annealing process on the microstructure, thermooxidation behavior and mechanical properties of GUR 1050 ultrahigh molecular weight polyethylene (UHMWPE) with respect to the postirradiation annealed material. For this purpose, the effects of a variety of irradiation and annealing conditions on microstructure and mechanical properties were investigated. Differential scanning calorimetry was performed to characterize melting temperature, crystalline content and crystal thickness, whereas transmission electron microscopy provided additional insights into crystal morphology. Thermogravimetric experiments in air served to assess thermooxidation resistance and changes associated to radiation‐induced crosslinking. Fatigue properties were studied from three different approaches, namely short‐term cyclic stress–strain tests, long‐term fatigue experiments and crack propagation behavior. Likewise, three experimental techniques (uniaxial tensile test, impact experiments, and load to fracture of compact tension specimens) allowed evaluation of the fracture resistance. The present findings confirm sequentially crosslinked UHMWPE exhibited improved thermooxidation resistance and thermal stability compared to post‐irradiation annealed UHMWPE. Also, the mechanical behavior, including the fatigue and fracture resistance, of these materials was generally comparable regardless of the annealing strategy. Therefore, the sequential irradiation and annealing process might provide higher oxidation resistance, but not a significant improvement in mechanical properties compared to the single radiation dose and subsequent annealing procedure. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Preparation and properties of a dispersing fluid loss additive based on humic acid graft copolymer suitable for cementing high temperature (200°C) oil wells
Authors: Salami Oyewole Taye , Plank Johann
Published: January 2013

A humic acid graft copolymer possessing both water‐retention and dispersing properties in cement slurry was synthesized by grafting lateral chains of 2‐acrylamido‐2‐methylpropane sulfonic acid (AMPS®), N,N‐dimethylacrylamide (NNDMA), and acrylic acid (AA) onto a backbone of humic acid using aqueous free radical polymerization. The graft copolymer is composed of 20 wt % humic acid backbone and 80 wt % graft chain (molar ratio AMPS/NNDMA/AA = 1 : 0.31 : 0.03), it exhibits a Mw of 323 kDa and is highly anionic in cement pore solution. The influence of this specific molecular design on cement flow properties is unraveled. When tested at 200°C, the graft copolymer achieved very low cement fluid loss values (∼50 mL) at low rheology. This behavior differentiates it from most common synthetic high temperature fluid loss additives which excessively viscosify cement slurries. The working mechanism of the graft copolymer was found to rely on adsorption onto the surface of hydrating cement. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Mechanical and thermal enhancements of benzoxazine‐based GF composite laminated by in situ reaction with carboxyl functionalized CNTs
Authors: Xu Mingzhen , Hu Jinquan , Zou Xingqiang , Liu Mengdie , Dong Shihua , zou Yanke , Liu Xiaobo
Published: January 2013

An easy and efficient approach by using carboxyl functionalized CNTs (CNT‐COOH) as nano reinforcement was reported to develop advanced thermosetting composite laminates. Benzoxazine containing cyano groups (BA‐ph) grafted with CNTs (CNT‐g‐BA‐ph), obtained from the in situ reaction of BA‐ph and CNT‐COOH, was used as polymer matrix and processed into glass fiber (GF)‐reinforced laminates through hot‐pressed technology. FTIR study confirmed that CNT‐COOH was bonded to BA‐ph matrices. The flexural strength and modulus increased from 450 MPa and 26.4 GPa in BA‐ph laminate to 650 MPa and 28.4 GPa in CNT‐g‐BA‐ph/GF composite, leading to 44 and 7.5% increase, respectively. The SEM image observation indicated that the CNT‐COOH was distributed homogeneously in the matrix, and thus significantly eliminated the resin‐rich regions and free volumes. Besides, the obtained composite laminates showed excellent thermal and thermal‐oxidative stabilities with the onset degradation temperature up to 624°C in N2 and 522°C in air. This study demonstrated that CNT‐COOH grafted on thermosetting matrices through in situ reaction can lead to obvious mechanical and thermal increments, which provided a new and effective way to design and improve the properties of composite laminates. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Determination of optimum cure parameters of 977‐2A carbon/epoxy composites for quickstep processing
Authors: Khan Laraib A. , Iqbal Zafar , Hussain Syed Tajammul , Kausar Ayesha , Day Richard J.
Published: January 2013

In this study polymer‐matrix composite has been processed using autoclave and Quickstep techniques. A phenomenological approach was adopted for the optimization of cure cycle for Quickstep of an aerospace grade epoxy composite (Cycom 977‐2A carbon/epoxy prepregs). Though there are reports concerning the processing and properties of materials using Quickstep technique, little work has been reported on the design of optimized cure cycle for Quickstep processing based on rheology, ultrasonic testing, and mechanical characterization. A step by step account is provided in this study, describing the introduction, balancing and combination of isothermal dwell periods and temperature ramps in order to control the resin viscosity. All the panels manufactured were qualitatively assessed using ultrasonic C‐scan and afterwards fiber and void content, panel thickness, flexural strength, and interlaminar shear strength (ILSS) were assessed and compared with those obtained from traditional autoclave‐ and oven‐cured laminates. The Quickstep panel properties produced from optimized cure cycle was superior to oven curing and was comparable with autoclave. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Preparation of chitosan modified talc and its application in high filler content paper
Authors: Yu Yang , Xue Guoxin , Gu Chunhong , Lou Jipan , Li Shizhen
Published: January 2013

Chitosan (CS) with different viscosity was investigated as a modifier of talc which was used to improve the strength properties and filler retention in high filler content papers. The particle size and morphology of the resulting modified talc were studied to confirm the successful modification. The zeta potential and coating amount of the CS modified talc were also investigated. It was found that CS viscosity was a critical factor for the filler modification and final paper properties. When high viscosity CS was applied, the resulting tensile strength of filled paper was 64% higher than that of unmodified talc at the filler content of 37% as well as maintained favorable optical properties. Furthermore, with the filler loading of 70% (based on the solid fiber weight), compared with that of unmodified talc, filler retention of modified talc was increased by 39%, while the drainage was little influenced. The field emission scanning electron microscopy images showed a better bonding capacity between modified talc and fibers than that of untreated talc. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Porous palygorskite‐polythiophene conductive composites for acrylic coatings
Authors: Zuo Shixiang , Yao Chao , Liu Wenjie , Li Xiazhang , Kong Yong , Liu Xiaoheng , Mao Huihui , Li Yingruo
Published: January 2013

Modified palygorskite‐polythiophene (MPA‐PTh) composites were prepared by chemical oxidative polymerization of palygorskite (PA) nucleartor with thiophene (Th) after the surface modification with γ‐(2,3‐epoxypropoxy) propytrimethoxysilane (KH‐560). The MPA‐PTh composites were doped in iodine vapor to create the porous palygorskite‐polythiophene (PMPA‐PTh) conductive composites. Fourier transform infrared spectra (FTIR), X‐ray photoelectron spectroscopy (XPS), X‐ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption–desorption isotherms using the Brunauer–Emmett–Teller method (BET) and electrochemical impedance spectrum (EIS) techniques were applied to characterize the modified PA and the prepared composites. According to FTIR and XPS, the KH‐560 was bound to the PA surface and the iodine ion (I3− and I5−) entered the PTh molecular chains. XRD, SEM, TEM, BET, and EIS analysis confirmed that the doping of iodine not only transform the core–shell MPA‐PTh into the PMPA‐PTh but also improve the electrical conductivity of composites. The PMPA‐PTh composites were fabricated that yield a volume resistivity of ∼2.44 × 102 Ω cm and a internal resistances of ∼100 Ω, and their BET surface area, BJH (Barrett–Joiner–Halenda) average pore size and BJH cumulative pore volume were improved in comparison with those of the MPA‐PTh composites. SEM images showed that the PMPA‐PTh composites could form consecutive space network and the PMPA‐PTh composites acrylic coating films had advisable conductivity. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Carbazoles on same main chain for polymer solar cells
Authors: Qin Ruiping , Jiang Yurong , Ma Heng , Yang Le , Liu Hengzhi , Chang Fanggao
Published: January 2013

Planar conjugated 2,7‐linked carbazole blocks: Q1(2,7‐dibromo‐9‐octyl‐9H‐carbazole); Q2(7,7′‐dibromo‐9,9′‐dioctyl‐9H,9′H‐2,2′‐bicarbazole); Q3 (7‐bromo‐7′‐(7‐bromo‐9‐octyl‐9H‐carbazol‐2‐yl)‐9,9′‐dioctyl‐9H,9′H‐2,2′‐bicarbazole) were coupled with same acceptor (4,7‐di[2,5‐thiophene]‐5,6‐dioctyloxy‐2,1,3‐Benzothiadiazole) to prepare polymers HXS‐1, 2, 3 (Scheme 1). Bulk‐heterojunction polymer solar cells (BHJ PSCs) with these polymers were made. Power conversion efficiency of HXS‐1 was proved to be over 5.4%. It declined dramatically to 0.43% and 0.23% for HXS‐2 and 3 respectively. Their absorption and X‐ray diffraction pattern show the torsion angle in main chain increased when more carbazole units were added. More carbazoles will make polycondensation reaction more difficult to get high molecular weight polymers. The torsion angle was calculated using a semiempirical molecular orbital method. All the results pointed out that the coplanarity in the conjugated backbone was destroyed. Electron delocalization was disturbed because p‐orbital overlapping only occurs effectively in the parallel orbit so charge cannot move a longer distance. This study offers a useful and important insight to designing polymers for high performance PSCs. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Investigation on high strength laser welds of polypropylene and high‐density polyethylene
Authors: Juhl Thomas Brokholm , Christiansen Jesper deClaville , Jensen Erik Appel
Published: January 2013

Mechanical strength in polymer weld interfaces in semi‐crystalline high density polyethylene (HDPE) and polypropylene (PP) is investigated. The welding method investigated is through transmission laser welding (TTLW). Utilizing the TTLW process with 0.4 wt % carbon black as absorber, a lap‐joint is formed which is tested for mechanical properties using an Instron tensile testing machine. In contrast to earlier investigations, the tensile tests conclude that 89% of the strength of a HDPE/HDPE weld was developed in a PP/HDPE weld with HDPE as the absorbing part. This high weld strength is explained from: (1) a relatively low reptation time being in the millisecond range for both HDPE and PP; (2) a polymer mesh size (tube diameter (a)) being similar to the equilibrium interpenetration depth, determined from Helfand's theory and the interaction parameter (χ); (3) The selected HDPE and PP were both metallocene catalyzed and constituted a similar crystallization temperature which is required for high crystallinity in/near the interface. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Effect of drawing on the molecular orientation and polymorphism of melt‐spun polyvinylidene fluoride fibers: Toward the development of piezoelectric force sensors
Authors: Magniez Kevin , Krajewski Andrew , Neuenhofer Martin , Helmer Richard
Published: January 2013

Thin piezoelectric polyvinylidene fluoride fibers containing a high piezoelectric β‐phase content of up to 80% were developed in this work using a melt‐spinning process. After crystallization from the melt, the fibers were subsequently stretched unidirectionally at 120°C between 25 and 75% of their original length. The effects on the molecular orientation, polymorphism and tensile properties of the fibers were investigated. Polarized infra‐red spectroscopy and X‐ray diffraction results show that the conversion of α‐phase to β‐phase occurred during the stretching process as a result of molecular alignment and creation of a dipole induced by the CF2 groups normal to the fiber direction. These fibers were then integrated into various weave architectures in order to design flexible two‐dimensional textile‐based piezoelectric force sensors. The piezoelectric responsiveness of these materials, tested under impact (70 Newton force, 1 Hz frequency) was very promising, with a maximum output voltage of up to 6 V and an average sensitivity of up to 55 mV/N measured. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
TIGHTLY CONTROLLED TETRACYCLINE‐INDUCIBLE TRANSCRIPTION SYSTEM FOR EXPLOSIVE GENE EXPRESSION IN CULTURED SILKWORM CELLS
Authors: Tatsuke Tsuneyuki , Lee Jae Man , Kusakabe Takahiro , Iiyama Kazuhiro , Sezutsu Hideki , Uchino Keiro
Published: January 2013

Tetracycline‐inducible gene expression (Tet‐on) system is a particularly powerful tool for transgenic research and has become one of the first choices for the control of transgene expression in a mammal and a fly. Previously, we have generated the modified reverse tetracycline‐controlled transactivators and tetO promoters for a Bombyx mori Tet‐on system. In order to further improve this system, Giant, a transcriptional silencer from Drosophila melanogaster, is introduced to repress leaky transcription in the absence of doxycycline. Further, the promoter responsibility to the tetracycline‐controlled transactivators is facilitated by introducing a synthetic minimal core promoter. With the tightly regulated second‐generation silkworm Tet‐on system, we obtain up to 300‐fold induction of gene expression with the addition of doxycycline.
Orchestration of Inflammation and Adaptive Immunity in Borrelia burgdorferi–Induced Arthritis by Neutrophil‐Activating Protein A
Authors: Codolo Gaia , Bossi Fleur , Durigutto Paolo , Bella Chiara Della , Fischetti Fabio , Amedei Amedeo , Tedesco Francesco , D'Elios Sofia , Cimmino Marco , Micheletti Alessandra , Cassatella Marco A. , D'Elios Mario M. , de Bernard Marina
Published: January 2013

Objective

Lyme arthritis (LA) is characterized by infiltration of inflammatory cells, mainly neutrophils (polymorphonuclear cells [PMNs]) and T cells, into the joints. This study was undertaken to evaluate the role of the neutrophil‐activating protein A (NapA) of Borrelia burgdorferi in eliciting inflammation and in driving the adaptive immune response.

Methods

Levels of NapA, interferon‐γ (IFNγ), interleukin‐17 (IL‐17), and T cell–attracting chemokines were assessed by enzyme‐linked immunosorbent assay in synovial fluid from patients with LA. The profile of T cells recruited into the synovia of patients with LA was defined by fluorescence‐activated cell sorting analysis. NapA was intraarticularly injected into rat knees, and the cells recruited in synovia were characterized. The role of NapA in recruiting immune cells was confirmed by chemotaxis assays using a Transwell system.

Results

NapA, IFNγ, IL‐17, CCL2, CCL20, and CXCL10 accumulated in synovial fluid from patients with LA. Accordingly, T cells obtained from these patients produced IFNγ or IL‐17, but notably, some produced both cytokines. NapA promoted neutrophil and T lymphocyte recruitment both in vitro and in vivo. Interestingly, the infiltration of T cells not only resulted from the chemotactic activity of NapA but also relied on the chemokines produced by PMNs exposed to NapA.

Conclusion

We provide evidence that NapA functions as one of the main bacterial products involved in the pathogenesis of LA. Accordingly, we show that, at very early stages of LA, NapA accumulates and, in turn, orchestrates the recruitment of inflammatory cells into the joint cavity. Thereafter, with the contribution of recruited cells, NapA promotes the infiltration of T cells producing IL‐17 and/or IFNγ.
Isolation and characterization of luciferase from Indian firefly, Luciola praeusta
Authors: Muthukumaran Thuraimony , KrishnaMurthy Nemani V , Sivaprasad Nagalingam , Sudhaharan Thankiah
Published: January 2013

Luciferase from Indian firefly Luciola praeusta (Coleoptera: Lampyridae: Luciolinae) was isolated and the properties compared with that of the North American firefly, Photinus pyralis. Luciola praeusta luciferase was purified using acetone extraction, gel‐filtration column chromatography, ammonium sulfate precipitation and anion exchange chromatography. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis indicates a homogeneous preparation and the molecular mass was slightly higher than that of Photinus pyralis. The effect of pH, buffer composition and metal ions on the spectral characteristics was studied. The maximum bioluminescence activity of luciferase was observed in ACES buffer at pH 6.5. The emission maximum of 562 nm (in crude extract) was red shifted to 570 nm in Tricine buffer at pH 7.8. In addition, the effect of bovine serum albumin on the storage stability of the protein was investigated. Based on the unique spectral characteristics observed, we propose that Luciola praeusta luciferase in the native form is suitable for the assay of biochemical metabolites in acidic pH. Copyright © 2013 John Wiley & Sons, Ltd.
A simple and rapid spectrofluorimetric method for determining the pharmacokinetics and metabolism of rhaponticin in rat plasma, feces and urine using a cerium probe
Authors: Sun Yang , Zhao Yingyong , Yang Xiaohui
Published: January 2013

Rhaponticin (RH) demonstrates a variety of pharmacological activities, including antitumor, antithrombotic and antioxidant effects. It is essential to establish a simple, rapid and reliable analytical method for determining the pharmacokinetics of RH. A simple cerium ion (Ce3+) probe method was developed and validated to determine RH in rat plasma, feces and urine. The fluorescence intensities of the cerium ion (Ce3+) were quenched by addition of RH, along with a remarkable red shift. Spectral data revealed that fluorescence quenching of Ce3+ by RH was due to the formation of a Ce3+–RH complex. Using to the Stern–Volmer equation, the binding parameters for interactions between Ce3+ and RH were obtained. Based on these, a rapid and simple spectrofluorimetric method was developed to determine the metabolism and pharmacokinetics of RH using a Ce3+ probe. The assay was linear over the concentration range of 0.11–9.52, 0.25–8.87 and 0.18–9.10 μM for plasma, feces and urine, respectivelyand RH recoveries were found to be 98.24 ± 0.8, 97.78 ± 1.2 and 97.54 ± 0.8% for plasma, feces and urine, respectively. The relative standard deviations were < 9.5%. The spectrofluorimetric method was simple and rapid for quantitative determination of RH and its metabolism, and was affordable for most laboratories because of the fluorescence spectroscopy and low equipment cost. These pharmacokinetic, bioavailability and metabolism studies of RH will provide helpful information for the development of suitable dosage forms and clinical references on rational administration. Copyright © 2013 John Wiley & Sons, Ltd.
An Automatic Molecular Dispenser of Chloride
Authors: Alibrandi Giuseppe , Amendola Valeria , Bergamaschi Greta , Dollenz Riccardo , Fabbrizzi Luigi , Licchelli Maurizio , Lo Vecchio Carmelo
Published: January 2013

The combined activity of the 1.1.1‐cryptand and of a dicopper(II) bistren cryptate complex including chloride makes the Cl− ion be continuously and slowly delivered to the solution, without any external intervention. The 1.1.1‐cryptand slowly releases OH− ions, according to a defined kinetics, and each OH− ion displaces a Cl− ion from the cryptate. Chloride displacement induces a sharp colour change from bright yellow to aquamarine and can be conveniently monitored spectrophotometrically, even in diluted solutions. The 1.1.1‐cryptand is the motor of a molecular dispenser (the dicopper(II) cryptate) delivering chloride ion automatically, from the inside of the solution.
Ionization of Atoms by Attosecond Pulses
Authors: Gets A.V. , Krainov V.P.
Published: January 2013

Ionization of atoms by ultrashort one‐cycle electromagnetic pulses is considered. First‐order time‐dependent perturbation theory for derivation of ionization probability by pulses with various field profiles is used. Numerical calculations for hydrogen and xenon atoms are done. Strong field‐phase dependence of ionization probability is shown. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The toxicity of a ternary biocide mixture to two consecutive earthworm (Eisenia fetida) generations
Authors: Schnug Lisbeth , Jakob Lena , Hartnik Thomas
Published: January 2013

The aim of the present study was to determine the toxicity of a mixture containing the biocides picoxystrobin, esfenvalerate, and triclosan to the reproduction and adult survival of two consecutive generations of Eisenia fetida (Savigny, 1826). Concentration addition and independent action were used to predict mixture toxicity. Due to degradation of mixture components during the course of the experiment, predictions were based both on the mixture composition at the beginning and the end of the exposure period. As degradations were dose–dependent, none of the calculated predictions were precise for the entire concentration range, although combining both predictions led us to conclude that lethal toxicity was well predicted by concentration addition and sublethal toxicity by independent action. Reproduction of the F1 generation was inhibited more (p < 0.0001) than reproduction of the F0 generation. Adult survival did not differ between generations. The accuracy of the mixture toxicity predictions thus depended on both the time-dependent mixture composition and the earthworm generation. The results of this study underline the need for more advanced mixture toxicity prediction models that consider degradation kinetics and changes in toxic effects over time. Environ. Toxicol. Chem. 2013;32:937–947. © 2013 SETAC
A Genome‐Wide Association Study for Serum Bilirubin Levels and Gene‐Environment Interaction in a Chinese Population
Authors: Dai Xiayun , Wu Chen , He Yunfeng , Gui Lixuan , Zhou Li , Guo Huan , Yuan Jing , Yang Binyao , Li Jun , Deng Qifei , Huang Suli , Guan Lei , Hu Die , Zhu Jiang , Min Xinwen , Lang Mingjian , Li Dongfeng , Yang Handong , Hu Frank B. , Lin Dongxin , Wu Tangchun , He Meian
Published: January 2013

Bilirubin is an effective antioxidant and is influenced by both genetic and environmental factors. Recent genome‐wide association studies (GWAS) have identified multiple loci affecting serum total bilirubin levels. However, most of the studies were conducted in European populations and little attention has been devoted either to genetic variants associated with direct and indirect bilirubin levels or to the gene‐environment interactions on bilirubin levels. In this study, a two‐stage GWAS was performed to identify genetic variants associated with all types of bilirubin levels in 10,282 Han Chinese individuals. Gene‐environment interactions were further examined. Briefly, two previously reported loci, UGT1A1 on 2q37 (rs6742078 and rs4148323, combined P = 1.44 × 10−89 and P = 5.05 × 10−69, respectively) and SLCO1B3 on 12p12 (rs2417940, combined P = 6.93 × 10−19) were successfully replicated. The two loci explained 9.2% and 0.9% of the total variations of total bilirubin levels, respectively. Ethnic genetic differences were observed between Chinese and European populations. More importantly, a significant interaction was found between rs2417940 in SLCO1B3 gene and smoking on total bilirubin levels (P = 1.99 × 10−3). Single nucleotide polymorphism (SNP) rs2417940 had stronger effects on total bilirubin levels in nonsmokers than in smokers, suggesting that the effects of SLCO1B3 genotype on bilirubin levels were partly dependent on smoking status. Consistent associations and interactions were observed for serum direct and indirect bilirubin levels.
Comparison study of differential transform method with finite difference method for magnetoconvection in a vertical channel
Authors: Umavathi J.C. , Ravi Kanth A.S.V. , Shekar M.
Published: January 2013

In this paper, coupled nonlinear equations governing the flow for magnetoconvection in a vertical channel for open and short circuits are solved. The calculations are carried out by using differential transformation method (DTM) which is a semi‐numerical–analytical solution technique. By using DTM, the nonlinear constrained governing equations are reduced to recurrence relations and related initial conditions are transformed into a set of algebraic equations. The principle of differential transformation is briefly introduced, and then applied for the aforementioned problems. The current results are then compared with those derived from the finite difference method (FDM) and perturbation method (PM) in order to verify the accuracy of the proposed method. The findings reveal that the DTM can achieve more suitable results in predicting the solution of such problems. © 2013 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library (wileyonlinelibrary.com/journal/htj). DOI 10.1002/htj.21035
“I'm Riskin' It”: Teachers Take On Consumerism
Authors: Harste Jerome C. , Albers Peggy
Published: January 2013

This qualitative study investigates how 90 teachers explored critical curriculum through their reading, analysis and creation of counter advertisements. Located in visual discourse analysis, we designed a study to investigate the question “To what extent can teachers engaged in a critical literacy curriculum talk back to messages of consumerism, especially through construction of counter ads? More specifically, we wanted to know: What messages do teachers talk back to when they read and analyze advertisements? How do they critically repackage their advertisement through counter ads they create? and What do teachers' interpretations of advertisements and their counter ads offer educators as insight for creating curriculum?We found that teachers did develop a language of critique for visual and written messages of consumerism, and found that knowing how to analyze visual texts enabled them to understand how to integrate this work into their own critical literacy curriculum.
“Untold Stories to Tell”: Making Space For The Voices of Youth Songwriters
Authors: Williams Wendy R.
Published: January 2013

This article shares findings from case studies of two eighteen‐year‐old songwriters, Bradley and James. The study investigated songwriter motivation, writing methods, and school experiences. Data was collected over the course of one year through two in‐depth interviews per songwriter, two teacher interviews, and 101 songwriting artifacts. Grounded theory and constant comparison methods were used during data analysis. This study found that Bradley's and James's music emphasizes acceptance of others and critical engagement with social issues. They see songwriting as a masculine alternative to journaling, and they have strong preferences regarding their writing tools, time, and spaces. Additionally, these songwriters prefer to write one line at a time, to skip pre‐writing, and to have a choice of topic—preferences that sometimes conflicted with their school experiences. This article concludes by offering suggestions for supporting songwriting in school.
Rhetorical Reading as a Gateway to Disciplinary Literacy
Authors: Warren James E.
Published: January 2013

This article shares findings from case studies of two eighteen‐year‐old songwriters, Bradley and James. The study investigated songwriter motivation, writing methods, and school experiences. Data was collected over the course of one year through two in‐depth interviews per songwriter, two teacher interviews, and 101 songwriting artifacts. Grounded theory and constant comparison methods were used during data analysis. This study found that Bradley's and James's music emphasizes acceptance of others and critical engagement with social issues. They see songwriting as a masculine alternative to journaling, and they have strong preferences regarding their writing tools, time, and spaces. Additionally, these songwriters prefer to write one line at a time, to skip pre‐writing, and to have a choice of topic—preferences that sometimes conflicted with their school experiences. This article concludes by offering suggestions for supporting songwriting in school.
Content Area Reading and Disciplinary Literacy: A Case for The Radical Center
Authors: Brozo William G. , Moorman Gary , Meyer Carla , Stewart Trevor
Published: January 2013

Within the past few years literacy scholars have begun voicing serious doubts on theoretical and practical grounds about the efficacy of the longstanding notion that every teacher is a teacher of reading. In this commentary, we add our voices to the conversation around content area literacy as well as offer our perspectives on the recent calls for alternative practices grounded in disciplinary literacy. We conclude by advocating compromise based on honest, intelligent dialogue between literacy specialists and content area teachers.
Promised Land?: English Learners Seeking Refuge at Lafayette High School
Authors: Cerre Naomi , Alsace Tamara , Gilmartin Jessica
Published: January 2013

This “water cooler” column features email conversations—as well as report excerpts—among principal Naomi Cerre, teacher Jessica Gilmartin, and Tamara Alsace, Director of Multilingual Education Department of Buffalo City School District (BCSD), Buffalo, New York. Principal Cerre is the leader at Lafayette High School, where 70% of its student population speaks a first language that is not English, resulting in an opulent linguistic school community of approximately 41 languages. Naomi began the conversation, noting her pride and vision for being the leader of a high school labeled persistently low achieving.
Web 2.0 Reflective Inquiry: A Transformative Literacy Teacher Education Tool
Authors: Stevens Elizabeth Years
Published: January 2013

This column features essays written by current middle school and high school teachers, media specialists, librarians, literacy coaches, curriculum specialists, administrators, preservice teachers, teacher educators, and adolescent and adult learners. They highlight diverse perspectives on teaching and/or learning with literacies to inspire reader reflection.
Inter‐ and intra‐rater reliability of blood and cerebrospinal fluid flow quantification by phase‐contrast MRI
Authors: Koerte Inga , Haberl Caroline , Schmidt Michael , Pomschar Andreas , Lee Sang , Rapp Petra , Steffinger Denise , Tain Rong‐Wen , Alperin Noam , Ertl‐Wagner Birgit
Published: January 2013

Purpose:

To evaluate the intra‐ and inter‐rater reliability of the quantification of blood and CSF flow rates by phase contrast MRI.

Materials and Methods:

Blood and CSF flows in the upper cervical region were imaged with velocity‐encoded cine‐phase contrast using 3T scanners from different manufacturers at two centers. Data of 6 subjects scanned in center A and of 5 subjects in center B were analyzed by six readers at two levels of training. Each data set was analyzed three times in a randomized order for a total of 33 data sets. Intra‐class correlation coefficients (ICC) were calculated for the primary measurements of areas and flow rates through the main cervical arteries, veins and the CSF space, and for secondary parameters derived from the individual flow rates.

Results:

ICC ranged from 0.80 to 0.96 for the lumen area and from 0.97 to 0.99 for the volumetric flow rate. The ICC for the derived secondary measures ranged from 0.85 to 0.99. Differences due to operator level of training were not statistically significant.

Conclusion:

High intra‐ and inter‐rater reliability of volumetric flow rate measurements is currently achievable across manufacturers and users' skill levels with a pulsatility based automated lumen segmentation. J. Magn. Reson. Imaging 2013;38:655–662. © 2013 Wiley Periodicals, Inc.