bluuebunny/crossref_metadata_2025_split huggingface dataset:
Redox initiator systems for emulsion polymerization of acrylates
Authors: Kohut‐Svelko Nicolas , Pirri Rosangela , Asua José M. , Leiza Jose R. 
Published: April 2009

AbstractThe performance of different redox initiator couples to initiate the emulsion polymerization of butyl acrylate at low temperature (40–50 °C) was investigated in both batch and seeded semibatch polymerizations. Polymerizations were carried out mimicking industrial conditions, that is, technical grade monomer and no N2 purging was used during the polymerizations. The redox systems used contained as oxidants persulfates or hydroperoxides and as reducing agents ascorbic acid, formaldehyde sulfoxilate (SFS), tetramethyl ethylene diamine (TMEDA), Bruggolit 6 and 7 (FF6 and FF7), and sodium metabisulfites. Batch experiments showed that for systems using persulfates, the ammonium persulfate (APS)/TMEDA system provided the lower induction period and higher conversion, whereas for the systems with hydroperoxide oxidants, tert‐butyl hydroperoxide (TBHP)/FF7, TBHP/SFS, and H2O2/FF7 were the best alternatives. When these selected systems were used in seeded semibatch experiments of BA with allyl methacrylate, it was found that to obtain similar kinetics and microstructure (gel content and crosslinking density) than in case of using a thermal initiator at 80 °C, the polymerization could be run at 40 °C if the reactor was purged with N2. Alternatively, in absence of N2 polymerization, temperature should be increased to 50 °C and initiator concentration increased. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2917–2927, 2009
Synthesis of block and star copolymers by photoinduced radical coupling process
Authors: Temel Gokhan , Aydogan Binnur , Arsu Nergis , Yagci Yusuf 
Published: April 2009

AbstractThe general design for the synthesis of AB diblock, and A2B and AB2 star copolymers based on the statistical coupling of poly(styrene) (PSt) and poly (methyl methacrylate) (PMMA) macromolecules containing photoreactive benzophenone is presented. For this purpose, mono‐ and bifunctional initiators for Atom Transfer Radical Polymerization (ATRP) bearing benzophenone group were synthesized and characterized. End‐ and mid‐chain benzophenone functional PSt and PMMA with low molecular weights were obtained by ATRP using these initiators in the presence of CuBr/N,N,N′,N″,N″‐pentamethyldiethylenetriamine (PMDETA) catalytic complex. Poly(styrene‐block‐methyl methacrylate) (PSt‐b‐PMMA) copolymers were prepared by photolysis of the solutions containing end functional PSt and PMMA in THF at λ = 350 nm for 60 min in the presence of a hydrogen donor such as N‐methyldiethanolamine (NMDEA). The proposed mechanism assumes hydrogen abstraction of photoexcited benzophenone moiety by NMDEA. Ketyl radicals resulting from abstraction reaction undergo radical‐radical coupling to form benzpinacol structure at the core. Formation of A2B and AB2 type star copolymers upon irradiation of solutions containing appropriate combinations of end‐ and mid‐chain functional polymers was also demonstrated. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2938–2947, 2009
A theoretical analysis of rheodielectric response of type‐A polymer chains
Authors: Uneyama Takashi , Masubuchi Yuichi , Horio Kazushi , Matsumiya Yumi , Watanabe Hiroshi , Pathak Jai A. , Roland C. Michael 
Published: April 2009

AbstractFor type‐A polymer chains having type‐A dipoles parallel along the chain backbone (such as cis‐polyisoprene), a theoretical analysis was conducted for the rheodielectric response to relate this response to the chain dynamics. The rheodielectric response in the shear gradient direction (y direction) under steady shear was analyzed on the basis of a Langevin equation. It turned out that the relaxation time is exactly the same for the rheodielectric relaxation function and the end‐to‐end vector autocorrelation function defined in the shear gradient direction and that the relaxation mode distribution also coincides for these functions at least up to second order of the shear rate (corresponding to the lowest order of nonlinearities of these functions). Consequently, the Green‐Kubo theorem holds satisfactorily, and the rheodielectric intensity is proportional to the squared chain size in y direction, 〈R〉, averaged over the time‐independent conformational distribution function under steady shear. The situation is more complicated under large amplitude oscillatory strain (LAOS) because the conformational distribution function fLAOS is synchronized with LAOS to oscillate at the LAOS frequency, Ω. The rheodielectric response under LAOS was found to detect this oscillation of fLAOS being coupled with the oscillation of the electric field, E(t) = E0sin ωt, and thus, split into a series of components oscillating at frequencies ω and ω ± βΩ (β = 1, 2, …). Consequently, the rheodielectric intensity under LAOS, evaluated from the component oscillating at ω, is no longer proportional to 〈R〉. However, the relative mode distribution and relaxation time of this component can be directly related to those of the end‐to‐end vector correlation averaged over a nonoscillatory part of fLAOS. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 1039–1057, 2009
Feasibility of Extending Rainbow Refractometry to Small Particles Using Femtosecond Laser Pulses
Authors: Bakic Saša , Xu Feng , Damaschke Nils , Tropea Cameron 
Published: April 2009

AbstractRainbow refractometry has been investigated numerically for small droplets under ultrashort pulse illumination. Using Fourier Lorenz–Mie Theory, local maxima of the scattering function were investigated as a function of the scattering angle, particle size and refractive index. The primary rainbow was shown to be detectable for pulse lengths as short as 10 fs and free of interferences with other scattering orders for droplet diameters down to 5 μm. An extension of the Generalized Lorenz–Mie Theory was used to obtain an estimation of the influence of nonsphericity on refractive index detection. Overall, the possibility of improved in situ temperature measurements with Rainbow refractometry for small particles was shown to be feasible.
Analysis of a Simple Test Device for Tribo‐Electric Charging of Bulk Powders
Authors: Šupuk Enes , Seiler Christian , Ghadiri Mojtaba 
Published: April 2009

AbstractWe have developed a simple device to characterise the tribo‐electric charging propensity of powders. A sample of around one gram of powder is shaken in a container by reciprocal strokes in a horizontal direction. The electric charge on the powder is quantified by a Faraday cup before and after shaking. In this paper, we analyse the operation of this simple test device by investigating the behaviour of α‐lactose monohydrate (α‐LM), hydroxy propyl cellulose (HPC) and a 50 : 50 binary mixture (by mass) of these two powders with various container surfaces commonly used in the pharmaceutical industry. The experiments are carried out in controlled environmental conditions and using different shaking times and frequencies of 10, 20 and 30 Hz. The experimental results show that the saturated charge is independent of the shaking frequency. Furthermore adhered particles coating the inner surface of the shaking container decrease the net amount of charge generated by up to 50 %.
A Comparative Study on PSD Models for Chromite Ores Comminuted by Different Devices
Authors: Taşdemir Adem , Taşdemir Tuba 
Published: April 2009

AbstractThe objective of this study was to characterize the particle size distributions (PSDs) of chromite ores comminuted by different devices, i.e., subjected to different breakage modes and to compare the performances of the PSD functions selected. Different PSDs were obtained for five different mineralogical samples of chromite ores by jaw, cone and hammer crushing and ball mill grinding. The PSDs of the products were characterized to find the most suitable model by Gates–Gaudin–Schuhmann (GGS) and Rosin–Rammler (RR) functions. It was found that the PSDs of all chromite types in single‐pass devices, i.e., jaw and cone crushing were better described by the GGS model than RR model. The RR model gave the best results for all ore sample PSDs generated by retention type systems, i.e., hammer crushing and ball mill grinding. Both distribution functions gave higher R2 values as the size distribution became uniform. The results of piecewise regression were found very useful to improve the performance of GGS distribution in terms of correlation coefficients for samples from a hammer crusher and ball mill.
The perceptions of Athenian physiotherapists on the referral service in Greece and its impact on professional autonomy
Authors: Chanou Konstantina , Sellars Julie 
Published: April 2009

AbstractBackground and Purpose. The attainment of professional autonomy is considered a priority of any profession. The development of autonomy in physiotherapy has differed among countries, with some achieving a high degree of autonomy while others have struggled. The current literature reveals little about the autonomy of physiotherapists in Greece, although it would appear they face both external and internal threats to autonomous practice and to the development of their profession. This exploratory study investigated Athenian physiotherapists' experiences of the referral system in Greece and its impact on professional autonomy. Methods. A qualitative, phenomenological approach was chosen, using a cluster sampling method. Ten physiotherapists participated in a 30‐minute, one‐to‐one, semi‐structured interview. The interview audio tapes were transcribed and an inductive analysis was carried out. When all transcripts had been coded, categories and themes were compared to record commonalities and differences to construct a hierarchy of essential themes expressing general views. Results. Physiotherapists were frustrated by the physiotherapy referral system in Greece. They revealed that their practice was restricted by factors, which included a long‐standing dominance by the medical profession, bureaucratic process and the public perception of the profession in addition to restrictions from within the profession itself. To overcome the perceived restrictions to practice and the development of autonomy, participants had adopted strategies in an attempt to effectively address the patients' needs. Conclusions. There are clear issues related to the management and delivery of the physiotherapy referral system in Greece which impact on professional autonomy. Physiotherapists are forced to manipulate the referral system to provide a more appropriate level of care, resulting, however, in an inequitable service across the physiotherapy provision. If professional autonomy of physiotherapists in Greece is to move forward, these issues need to be acknowledged by governmental and professional bodies, as therapists can not be expected to undertake this journey alone. Copyright © 2009 John Wiley & Sons, Ltd.
TENS and FES for sensory impairment and gait dysfunction following removal of spinal cord ependymoma — a case report
Authors: Donnellan Clare P. , Caldwell Kate 
Published: April 2009

AbstractBackground. Sensory deficits are commonly reported following the resection of spinal cord tumours. The use of transcutaneous electrical nerve stimulation (TENS) as augmented sensory input is described in the research literature but rarely in the clinical literature. Functional electrical stimulation (FES) is used for people with motor impairments rather than sensory impairments. Method and results. This case report describes the use of TENS and FES for a patient with severe sensory loss and mild weakness in the right leg following the removal of an intramedullary spinal cord tumour. The patient was able to walk more quickly and more confidently when using TENS and FES in combination. She consistently reported greater benefits from TENS alone compared to FES alone and continued to use TENS delivered via a sock electrode at six months after surgery. Conclusion. The use of TENS as a sensory stimulus was an invaluable component of this patient's treatment, allowing her to engage in a more challenging balance and gait programme at an earlier stage in her rehabilitation. Combining FES with TENS was also useful and allowed treatment to address motor and sensory impairments concurrently during functional activity. Copyright © 2009 John Wiley & Sons, Ltd.
Prevalence, risk factors and preventive strategies in work‐related musculoskeletal disorders among Israeli physical therapists
Authors: Rozenfeld Vitaly , Ribak Joseph , Danziger Josepha , Tsamir Judith , Carmeli Eli 
Published: April 2009

AbstractBackground and Purpose. Although physical therapists (PTs) have extensive knowledge of body mechanisms and injury prevention, work‐related musculoskeletal disorders (WRMD) are quite common in this population. The purposes of this study were: to determine the prevalence and impact of WRMD among Israeli PTs; to investigate WRMD risk factors and to identify preventive strategies used by PTs; and to compare the risk of injuries in two professional settings: rehabilitation centres (RCs) and outpatient clinics (OPCs). Method. A validated, modified Cromie questionnaire, translated into Hebrew, was distributed to the PTs at their workplaces. The relationship between WRMD symptoms and professional settings was analysed by Pearson chi‐square. The risk models were developed by logistic regression. One hundred and twelve PTs working in OPCs and RCs who defined themselves as healthy individuals were the subjects of this study. Results. Lifetime prevalence of WRMD was 83%. The highest prevalence of WRMD was in the lower back area (80%). Rehabilitation treatment was associated with an increased risk of lower back (odds ratio [OR] = 1.05) and shoulder symptoms (OR = 1.04); manual treatment was associated with an increased risk of wrist/thumb symptoms (OR = 1.11). Discussion. Work in RCs was associated with an increased prevalence of lower back/shoulder symptoms, whereas work in OPCs was associated with an increased prevalence of thumb/wrist symptoms. PT's used different strategies to reduce risk of WRMD, including altering practice technique. The respondents recommended administrative and ergonomic changes in the workplace. Conclusion. Workplace‐specific interventions to reduce WRMD in PTs should be developed and tested in future studies. Copyright © 2009 John Wiley & Sons, Ltd.
High‐throughput screening of optimal solution conditions for structural biological studies by fluorescence correlation spectroscopy
Authors: Sugiki Toshihiko , Yoshiura Chie , Kofuku Yutaka , Ueda Takumi , Shimada Ichio , Takahashi Hideo 
Published: April 2009

AbstractProtein aggregation is an essential molecular event in a wide variety of biological situations, and is a causal factor in several degenerative diseases. The aggregation of proteins also frequently hampers structural biological analyses, such as solution NMR studies. Therefore, precise detection and characterization of protein aggregation are of crucial importance for various research fields. In this study, we demonstrate that fluorescence correlation spectroscopy (FCS) using a single‐molecule fluorescence detection system enables the detection of otherwise invisible aggregation of proteins at higher protein concentrations, which are suitable for structural biological experiments, and consumes relatively small amounts of protein over a short measurement time. Furthermore, utilizing FCS, we established a method for high‐throughput screening of protein aggregation and optimal solution conditions for structural biological experiments.
Selenomethionine incorporation in proteins expressed in Lactococcus lactis
Authors: Berntsson Ronnie P.‐A. , Alia Oktaviani Nur , Fusetti Fabrizia , Thunnissen Andy‐Mark W. H. , Poolman Bert , Slotboom Dirk‐Jan 
Published: April 2009

AbstractLactococcus lactis is a promising host for (membrane) protein overproduction. Here, we describe a protocol for incorporation of selenomethionine (SeMet) into proteins expressed in L. lactis. Incorporation efficiencies of SeMet in the membrane protein complex OpuA (an ABC transporter) and the soluble protein OppA, both from L. lactis, were monitored by mass spectrometry. Both proteins incorporated SeMet with high efficiencies (>90%), which greatly extends the usefulness of the expression host L. lactis for X‐ray crystallography purposes. The crystal structure of ligand‐free OppA was determined at 2.4 Å resolution by a semiautomatic approach using selenium single‐wavelength anomalous diffraction phasing.
Total chemical synthesis of the D2 domain of human VEGF receptor 1
Authors: Goncalves Victor , Gautier Benoit , Huguenot Florent , Leproux Pascale , Garbay Christiane , Vidal Michel , Inguimbert Nicolas 
Published: April 2009

AbstractThe interaction of the vascular endothelial growth factor (VEGF) with its cellular receptors exerts a central role in the regulation of angiogenesis. Among these receptors, the VEGF receptor 1 may be implicated in pathological angiogenesis. Here, we report the first total chemical synthesis of the VEGF‐binding domain of the VEGF receptor 1. Aggregation issues were overcome by the use of a low‐substituted resin and the stepwise introduction of pseudoproline dipeptides and Dmb‐glycines. The folding of the protein was achieved by air oxidation and its biological activity was verified on ELISA‐based assays. Copyright © 2009 European Peptide Society and John Wiley & Sons, Ltd.
Comparative study of transport properties of compressively strained epitaxial and polycrystalline La0.88Sr0.12MnO3 thin films
Authors: Prasad Ravikant , Singh Mangala Prasad , Prellier Wilfred , Siwach Praveen Kumar , Rawat Rajiv , Kaur Amarjeet , Singh Hari Krishana 
Published: April 2009

AbstractWe report a comparative study of the magnetoelectrical properties of epitaxial and polycrystalline thin films of lightly doped manganite La0.88Sr0.12MnO3 (LSMO). The LSMO thin films are deposited on single‐crystal LaAlO3 (LAO/(100)) and yttria‐stabilized ZrO2 (ZO/(100)) substrates by on‐axis DC magnetron sputtering from high‐density targets prepared by a wet chemical route. Films deposited on LAO (6 nm and 35 nm thick) are epitaxial and AFM investigations show clean surface morphology. In contrast, films on ZO (20 nm and 35 nm) are polycrystalline. Small variation in grain size is seen in the surface morphology of films on ZO. Both 6 nm and 35 nm thick films on LAO show sharp I–M transitions around the TC with TIM being 275 K and 285 K, respectively. The TIM of films on ZO is drastically suppressed as compared to the same for films on LAO. The large enhancement in TC and hence TIM of LSMO films on LAO has been explained in terms of the compressive strain arising due to the mismatch between the lattice parameters of LAO and LSMO. The absence of such strain in LSMO films on ZO accounts for the lower TIM values. The LSMO/LAO films also show large magnetoresistance only in the vicinity of the TIM and it decreases strongly on lowering and increasing the temperature. In contrast, the LSMO/ ZO films show relatively lower MR spreading over a wider temperature range. The electrical transport of all the films, both in the PM as well as the FM regions have been analyzed in the framework of several models and the suitability of each model has been discussed. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Bound states in the continuum in electronic transport through parallel‐coupled quantum‐dot structures
Authors: Han Yu , Gong Weijiang , Wei Guozhu 
Published: April 2009

AbstractThe occurrence of bound states in continuum (BICs) are theoretically studied, by investigating the electronic transport through coupled quantum‐dot structures (a quantum‐dot chain and a quantum‐dot ring) embodied in an Aharonov–Bohm interferometer. It is found that for the structure of a quantum‐dot chain, the BICs will come into being only under the condition of the same‐numbered quantum dots coupled to the quantum dots in the arms of the interferometer. But with respect to the quantum‐dot ring, the occurrence of BICs is remarkable, independent of the number of quantum dots in the ring. Furthermore, by the presence of an appropriate magnetic flux through the interferometer, the linear conductance spectrum of the (2n + 1)‐quantum‐dot ring (n ∈ integer) is the same as that of the 2n ‐quantum‐dot chain, on account of the occurrence of BICs in electron transport through these two kinds of systems. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structural transformations and magnetic properties of Bi1–xLnx FeO3 (Ln = La, Nd, Eu) multiferroics
Authors: Troyanchuk I. O. , Bushinsky M. V. , Karpinsky D. V. , Mantytskaya O. S. , Fedotova V. V. , Prochnenko O. I. 
Published: April 2009

AbstractCrystal structures of Bi1–x Lnx FeO3 systems (Ln = La, Nd, Eu) are studied using X‐ray and neutron diffraction, magnetization measurements as well as electron microscopy. It was shown that the unit cell of the Bi1–x Lax FeO3 system is described with the R3c space group in the concentration interval 0 < x < 0.15, with the space group Imma (0.4 < x < 0.5) and with the Pnma at x > 0.5. The mixed‐phase state was observed in the range 0.15 < x < 0.4 independent of synthesis conditions. A similar sequence of the phase transformations was observed for Bi1–x Ndx FeO3 system. In the case of Bi1–x Eux FeO3 series the unit cell is rhombohedral (R3c) at x < 0.08 and orthorhombic (Pnma) at x > 0.20, whereas no evidence for Imma phase was found. The magnetization study has revealed the spontaneous magnetization to be associated with Pnma and Imma phases that do not allow conventional ferroelectricity. The ferroelectric R3c phase exhibits metamagnetic behavior due to transition from an incommensurately modulated antiferromagnetic state to a weak ferromagnetic state. Substitution of Bi3+ with Ln3+ leads to a strong decrease of external magnetic field inducing a metamagnetic transition. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Adaptive regulation in bimodal linear systems
Authors: Wu Zhizheng , Ben Amara Foued 
Published: April 2009

AbstractThis paper considers an adaptive regulation problem for switched bimodal linear systems where it is desired to achieve regulation against unknown sinusoidal exogenous inputs representing disturbance or reference signals. Switching among plant models as well as among disturbance and reference signals is defined according to a performance variable. The design of the proposed adaptive regulators involves two main steps. First, a set of observer‐based Q‐parameterized stabilizing controllers for the switched system is constructed, and a sufficient regulation condition for the resulting switched closed‐loop system is presented. Second, an adaptation algorithm is developed to tune the Q parameter in the expression of the parameterized controller and make it converge to the desired Q parameter that guarantees regulation for the switched system. The tuning of the Q parameter is performed to compensate for the lack of information on the properties of the sinusoidal
exogenous inputs. Finally, a numerical example is presented to illustrate the effectiveness of the proposed method. Copyright © 2009 John Wiley & Sons, Ltd.