bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of acrylic dental polymers
Authors: Vera‐Graziano Ricardo , Martínez‐Richa Antonio , Palacios‐Alquisira Joaquín , Barceló‐Santana Federico , Castaño‐Meneses Victor 
Published: March 2011

AbstractThe chemical structure and the molecular parameters of four dental acrylic polymer materials (samples P‐1 to P‐4) and two polyacrylic acids of different molecular weight (relative molecular mass) used as model compounds (samples Paa‐1 and Paa‐2) were studied and correlated with polymer structure and molecular weight. All polymer samples show low molecular weights, MW, and broad poly‐dispersity as obtained by GPC. Samples P‐3 and P‐4 show the lower MW and bi‐modal distribution, one peak corresponding to the polymer and the other to a low molecular weight compound at a lower concentration. The other polymer samples show unimodal distribution. Initially, all samples were soluble in water and dioxane above 99.8%. However, after lyophilization at −50 °C they showed different degrees of solubility because of partial gelation. The FTIR and, 1H and 13C‐NMR spectra of Paa‐1, Paa‐2 in D2O show the pattern characteristic of poly(acrylic acid). The polymers of P‐1 and P‐2 are mainly poly(acrylic acid). The P‐3 spectra show the peak pattern for an (acrylic acid/methyl acrylate) copolymer of about 2:1 composition as calculated from the NMR spectra. The P‐4 is an oligomer derived from 2‐hydroxyethyl methacrylate. Solid 13C‐NMR spectra confirm the above structures and evidence anhydride formation after lyophilization. The MW and the linear expansion coefficient, α, were derived from intrinsic viscosity in theta and perturbed conditions. From this, the steric hindrance parameter, A, the molecular stiffness, σ, and the second virial coefficient, A2, were calculated using different thermodynamic models. The Flory‐Fox‐Shafgagen and the Stockmayer‐Fixman models fit better the experimental data and can be used to describe the molecular parameters of the acrylic polymers. Light scattering was used to compare results.
Miscibility behaviour of blends of a thermoplastic polyester polyurethane with vinyl polymers
Authors: Danait Achala , Deshpande Dinkar D. 
Published: March 2011

AbstractA method based on the intrinsic viscosities of transfer has been used to predict miscibility of polymer blends. This method has been applied to study the change in the phase behaviour of a microphase separated polyester polyurethane (PSPU) on blending with polyvinyl chloride (PVC), polyvinyl acetate (PVAc) and a vinyl chloride‐vinyl acetate copolymer (VCVAc). The PVC/PSPU blends are found to exhibit complete miscibility over the entire composition range. PVAc/PSPU blends show immiscibility while VCVAc/PSPU blends show partial miscibility. Thermal analysis and scanning electron microscopic studies of the blend films have confirmed the results evaluated on the basis of the viscosity method.
Treatment of Ewing sarcoma family of tumors with a modified P6 protocol in children and adolescents
Authors: Mora Jaume , de Torres Carmen , Parareda Andreu , Torner Ferran , Galván Patricia , Rodríguez Eva , Cardesa Teresa , Salvador Héctor , Suñol Mariona , Huguet Ramon , Cruz Ofelia 
Published: March 2011

AbstractBackgroundReported overall survival (OS) rates of patients with localized Ewing sarcoma family of tumors (ESFT) are >80% when treated with the MSKCC P6 protocol. However, it has been associated with a 5.8% incidence of secondary leukemias. A modified P6 (mP6) protocol with reduced exposure to chemotherapy is presented.ProcedureThirty‐one newly diagnosed ESFT patients were enrolled onto this phase II, single‐arm, non‐randomized protocol. Courses 1, 2 and 4 consisted of cyclophosphamide 4.2 g/m2, doxorubicin 75 mg/m2, and vincristine 2 mg/m2 (CDV). Cycles 3 and 5 consisted of ifosfamide 9 g/m2 and etoposide 500 mg/m2 (IE). Course 5 ifosfamide was 14 g/m2 if necrosis was <90%.ResultsTwenty‐four patients had loco‐regional disease and seven had metastases. The 4‐year event‐free survival (EFS) rate for patients with localized tumors is 83% and overall survival (OS) is 92%. The 3‐year EFS rate for patients with distant metastases is 28% and OS rate is 42%. EWS‐FLI1 fusion genes were detected in 17 cases (74%) and EWS‐ERG in six cases (26%). Type 1 EWS‐FLI1 variant was present in 6/7 metastatic patients and 3/16 loco‐regional cases (P = 0.001). None of the patients experienced tumor progression before remission. All relapses occurred within 2 years from the end of treatment and local relapses (n = 3) happened in patients who did not receive radiation therapy. No secondary malignancies have been observed, median follow‐up of 4.3 years for surviving patients.ConclusionsIn this pilot study, the mP6 protocol produced a complete remission rate of 83% at 4 years in non‐metastatic ESFT reducing the risk of secondary malignancies. Pediatr Blood Cancer 2011;57:69–75. © 2011 Wiley‐Liss, Inc.
A study on fusion and rheological behaviors of PVC/SiO2 microcomposites and nanocomposites: The effects of SiO2 particle size
Authors: Ari Gulsen Albayrak , Aydin Ismail 
Published: March 2011

AbstractIn this study, poly(vinyl chloride) (PVC) and silica (SiO2) microcomposites and nanocomposites were prepared by melt mixing in a Haake torque rheometer. The fusion and rheological behaviors of PVC/SiO2 composites were evaluated by means of torque data recorded during processing to investigate the influence of the SiO2 particle size on these behaviors. It was found that the fusion time and the fusion temperature decreased with the decreasing of SiO2 particle size, whereas the fusion torque increased with the decreasing of particle size. The PVC/Si‐25‐nm nanocomposite (PVC including the 25 nm of SiO2) showed the highest apparent viscosity among the PVC/SiO2 microcomposites and nanocomposites prepared in this study. Scanning electron microscopy results demonstrated that some aggregates, whose sizes about 60–90 nm, were formed when the 25 nm of SiO2 was used as filler. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers
On superembedding approach and its possible application in search for SO(32) heterotic five‐brane equations
Authors: Bandos I.A. 
Published: March 2011

AbstractWe elaborate the superembedding description of simple D = 10, N = 1 five‐brane and discuss the possible application of the superembedding approach in search for the equations of motion of the mysterious SO(32) heterotic five brane on this basis.
Stringy instantons and dualities
Authors: Frau M. 
Published: March 2011

AbstractWe discuss non‐perturbative corrections to the gauge kinetic functions in a four‐dimensional 𝒩 = 2 gauge theory realized with a system of D7/D3‐branes in a compactification of type I′ theory on 𝒯4ℤ2 × ℤ2. The non‐perturbative contributions arise when D(–1) branes, corresponding to stringy instantons, are added to the system; such contributions can be explicitly evaluated using localization techniques and precisely match the results predicted by the heterotic/type I′ duality. This agreement represents a very non‐trivial test of the stringy multi‐instanton calculus.
Strange metallic behaviour and the thermodynamics of charged dilatonic black holes
Authors: Meyer R. , Goutéraux B. , Kim B.S. 
Published: March 2011

AbstractWe review a recent holographic analysis [1] of charged black holes with scalar hair in view of their applications to the cuprate high temperature superconductors. We show in particular that these black holes show an interesting phase structure including critical behaviour at zero temperature or charge, describe both conductors and insulators (including holographic Mott‐like insulators), generically have no residual entropy and exhibit experimentally observed scaling relations between electronic entropy, specific heat and (linear) DC resistivity. Transport properties are discussed in the companion contribution [2] in these proceedings.
Modifications of laser field assisted intersubband transitions in the coupled quantum wells due to static electric field
Authors: Prasad Vinod , Dahiya Brijender 
Published: March 2011

AbstractWe consider the electron bound in the conduction band of a coupled asymmetric double quantum well (ADQW) interacting with static as well as strong monochromatic field in terahertz (THz) region. We use non‐perturbative Floquet theory to study the static field and quantum well (QW) system in the presence of strong laser fields. We show that the intersubband dynamics gets modified due to the static field. The sensitivity to the ratio of strengths of static and laser field (Es/E0) of the state populations can be used in various optoelectronic device applications.
High‐field domains from dc to 60 GHz
Authors: Böer Karl W. 
Published: March 2011

AbstractThe history of the high‐field domains is given with the description of the experimental and theoretical results of the team of the author in the first decade after their discovery in 1958. This work is done at CdS single crystal platelets that are used as a model substance. The major findings of modern high‐field domain research that followed their original research are then reviewed. It is emphasized that all high‐field domains are created for reasons of the minimum entropy production principle when the conductivity decreases more than linear within a semiconductor. The application of these high‐field domains in important semiconductor devices are reviewed that have now reached a multibillion dollar market.
Amorphous piezoresistive and piezoelectric sensors for robotics applications
Authors: Somolinos Jose Andrés , Morales Rafael , García Alfonso , Morón Carlos 
Published: March 2011

AbstractUltrasonic transducers have often been used in the development of sensory systems for robotics applications. In most cases, these sensory systems are based on the determination of times of flight for signals from every transducer. In this work we have used piezoresistive and piezoelectric materials to measure the instant and position collision in metallic structures by using the difference of the times of propagation of an acoustic wave when it is produced over a ferromagnetic (iron, steel or another material) based structure. An immediate application of the proposed method is the detection and location of impacts over the metallic links of an industrial robot or the collision position in a metallic structure for an automated inspection. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Metal‐Ion‐Induced Formation and Stabilization of Protein Cages Based on the Cowpea Chlorotic Mottle Virus
Authors: Minten Inge J. , Wilke Koos D. M. , Hendriks Linda J. A. , van Hest Jan C. M. , Nolte Roeland J. M. , Cornelissen Jeroen J. L. M. 
Published: March 2011

AbstractThe cowpea chlorotic mottle virus (CCMV) is a versatile building block for the construction of nanoreactors and functional materials. Upon RNA removal, the capsid can be reversibly assembled and disassembed by adjusting the pH. At pH 5.0 the capsid is in the native assembled conformation, while at pH 7.5 it disassembles into 90 capsid protein dimers. This special property enables the encapsulation of various molecules, such as protein and enzymes, but only at low pH. It is possible to stabilize the capsid at pH 7.5 by addition of negatively charged polyelectrolytes or negatively charged particles, but these methods all fill the interior of the capsid, leaving little or no space for other cargo molecules. This pH restriction therefore severely limits the range of enzymes that can be encapsulated, and hampers the investigation of the CCMV capsid as a nanoreactor for the study of enzymes in confined spaces. Herein, the interaction of N‐terminal histidine‐tag‐modified capsid proteins with several metal ions is reported. Depending on the conditions used, nanometer‐sized protein particles or capsidlike architectures are formed that are stable at pH 7.5. This metal‐mediated stabilization methodology is employed to form stable capsids containing multiple proteins at pH 7.5, thereby greatly expanding the scope of the CCMV capsid as a nanoreactor.
A phenomenological model of finite strain viscoplasticity with distortional hardening
Authors: Shutov A.V. , Panhans S. , Kreißig R. 
Published: March 2011

AbstractIn this paper we suggest a thermodynamically consistent approach to the simulation of a rate dependent material response at finite strains. The nonlinear mechanical phenomena which are covered by the proposed material model include distortional, kinematic, and isotropic hardening. Firstly, we present a new two‐dimensional rheological model of distortional hardening, which predicts the yield curve in the stress space to be a limaçon of Pascal. Such effects like the distortion of the yield surface in the stress space and its orientation depending on the loading path are captured by the rheological model in a vivid way. Next, the rheological model serves as a guideline for the construction of the constitutive equations. In particular, the kinematic assumptions, the ansatz for the free energy, and the form of the yield function are motivated by the rheological model. Further, two types of flow rules are considered in this study: a normality rule and a radial rule, both thermodynamically consistent. Moreover, we formulate explicitly the constraints on the material parameters, which guarantee the convexity of the yield surface. Furthermore, implicit time‐stepping methods are considered which exactly preserve the incompressibility of the inelastic flow. Finally, the basic features of the predicted material response are illustrated by a series of numerical simulations. In particular, the simulation results are compared to the real experimental data.
Severe burn injury induces a characteristic activation of extracellular signal‐regulated kinase 1/2 in spinal dorsal horn neurons
Authors: Whitel John P.M. , Kol Chin Wing , Fidalgol Antonio Rei , Cibellil Mario , Paulel Cleoper C. , Andersonl Peter J. , Cruzl Celia , Gombal Szabolcs , Mateszl Klara , Veressl Gabor , Avelinol Antonio , Nagyl Istvan 
Published: March 2011

AbstractWe have studied scalding‐type burn injury‐induced activation of extracellular signal‐regulated kinase 1/2 (ERK1/2) in the spinal dorsal horn, which is a recognised marker for spinal nociceptive processing. At 5 min after severe scalding injury to mouse hind‐paw, a substantial number of phosphorylated ERK1/2 (pERK1/2) immunopositive neurons were found in the ipsilateral dorsal horn. At 1 h post‐injury, the number of pERK1/2‐labelled neurons remained substantially the same. However, at 3 h post‐injury, a further increase in the number of labelled neurons was found on the ipsilateral side, while a remarkable increase in the number of labelled neurons on the contralateral side resulted in there being no significant difference between the extent of the labelling on both sides. By 6 h post‐injury, the number of labelled neurons was reduced on both sides without there being significant difference between the two sides. A similar pattern of severe scalding injury‐induced activation of ERK1/2 in spinal dorsal horn neurons over the same time‐course was found in mice which lacked the transient receptor potential type 1 receptor (TRPV1) except that the extent to which ERK1/2 was activated in the ipsilateral dorsal horn at 5 min post‐injury was significantly greater in wild‐type animals when compared to TRPV1 null animals. This difference in activation of ERK1/2 in spinal dorsal horn neurons was abolished within 1 h after injury, demonstrating that TRPV1 is not essential for the maintenance of ongoing spinal nociceptive processing in inflammatory pain conditions in mouse resulting from at least certain types of severe burn injury.
A novel dynamic walker with heel, ankle, and toe rocker motions
Authors: Kumar R. Prasanth , Özer Abdullah , Kim Gabsoon , Yoon Jungwon 
Published: March 2011

SUMMARYThis paper proposes a novel dynamic walker capable of walking with heel, ankle, and toe rocker motions. The heel and toe rocker motions are obtained by using inelastic stoppers between leg and foot, which limit the range of rotation of the foot about the ankle joint. A generalized set of equations of motion and associated transition equations applicable for multiple foot segments is derived. Passive dynamic walking is studied with equal heel and toe strike angles for the case of symmetric foot walking. It is shown that by including the ankle joint, low-speed walking is made possible. The energy efficiency of the proposed walker is studied theoretically and through numerical simulations. Finally, three different underactuated modes of active walking that do not require toe and heel actuation are presented. In order to implement these modes of walking, the proposed walker can be constructed with little modification from an existing flat-foot walker that uses ankle rocker motion alone. Results show that substantial benefits can be obtained in efficiency and stability compared to point/flat-foot walker of the same leg length and mass distribution.
The small RNA PhrS stimulates synthesis of the Pseudomonas aeruginosa quinolone signal
Authors: Sonnleitner Elisabeth , Gonzalez Nicolas , Sorger‐Domenigg Theresa , Heeb Stephan , Richter Andreas S. , Backofen Rolf , Williams Paul , Hüttenhofer Alexander , Haas Dieter , Bläsi Udo 
Published: March 2011

SummaryQuorum sensing, a cell‐to‐cell communication system based on small signal molecules, is employed by the human pathogen Pseudomonas aeruginosa to regulate virulence and biofilm development. Moreover, regulation by small trans‐encoded RNAs has become a focal issue in studies of virulence gene expression of bacterial pathogens. In this study, we have identified the small RNA PhrS as an activator of PqsR synthesis, one of the key quorum‐sensing regulators in P. aeruginosa. Genetic studies revealed a novel mode of regulation by a sRNA, whereby PhrS uses a base‐pairing mechanism to activate a short upstream open reading frame to which the pqsR gene is translationally coupled. Expression of phrS requires the oxygen‐responsive regulator ANR. Thus, PhrS is the first bacterial sRNA that provides a regulatory link between oxygen availability and quorum sensing, which may impact on oxygen‐limited growth in P. aeruginosa biofilms.
Is PUVA maintenance therapy necessary in patients with early‐stage mycosis fungoides? Evaluation of a treatment guideline over a 28‐month follow‐up
Authors: Sánchez María A. , González Tatiana , Gaitán Miguel F. , Zuluaga Ángela , Jiménez Sol B. , de Galvis Yolanda T. 
Published: March 2011

AbstractBackground  Cutaneous T‐cell lymphoma is a rare condition that represents 2% of all lymphomas and 75–80% of primary cutaneous lymphomas. The objective of the present study is to evaluate a clinical practice guideline.Methods  This paper reports a prospective cohort study with a five‐year follow‐up. This is the second report to describe the analysis of data obtained during follow‐up of 28 months. To date, 40 patients diagnosed with early‐stage mycosis fungoides (stage IA, n = 20; stage IB, n = 20) have been enrolled. All patients have been treated with a minimum of 58 sessions of psoralen and long‐wave ultraviolet radiation, with complete clinical and histological clearance of lesions. Variables considered include disease duration, treatment time, treatment dose, and history of relapse. Complete physical examinations and diverse complementary examinations were performed. A tumor–node–metastasis–blood staging system was applied. The population was divided into two groups according to results consisting, respectively, of those who relapsed during follow‐up (n = 12) and those who did not (n = 28).Results  History of relapse was the variable most strongly associated with future relapse (relative risk = 10.38, 95% confidence interval 2.64–40.72). No statistically significant difference between the groups according to receipt of maintenance therapy was found (P = 0.161).Conclusions  Our results strongly suggest that maintenance therapy does not prevent future relapse. However, history of relapse is a strong predictor for future relapse.
Effectively widening the gene pool of oilseed rape (Brassica napus L.) by using Chinese B. rapa in a ‘virtual allopolyploid’ approach
Authors: Mei JiaQin , Fu Ying , Qian LunWen , Xu XinFu , Li JiaNa , Qian Wei 
Published: March 2011

With 2 figures and 2 tables Abstract Brassica rapa (AA), which has a high level of genetic diversity, has been used to widen the genetic base of oilseed rape (B. napus L., AACC). However, the differences in the degree to which the genetic base of oilseed rape can be widened using different forms of B. rapa have not been well characterized. We used a strategy of virtual allopolyploid to investigate the genetic differences between the A subgenome of natural oilseed rape and different ecotypes of B. rapa. In this strategy, the genetic characteristics of the virtual allopolyploid lines are deduced from the genotypes of the parental lines which are established using molecular markers, without the need for interspecific hybridization. Three genotypes of B. oleracea and 56 accessions of B. rapa which originated from Europe, China and India were genotyped using simple sequence repeat markers, together with nine oilseed rape lines representing spring, semi‐winter and winter types. The genotypes of 168 virtual allopolyploid lines were derived from those of the parental lines and compared with those of the natural oilseed rape lines. Our data revealed that the virtual allopolyploid lines that were derived from Chinese semi‐winter B. rapa showed substantial genetic variation from natural oilseed rape. This indicates that Chinese semi‐winter B. rapa can be used effectively to broaden the germplasm of oilseed rape.
Quantitative variation analysis of fetal DNA in maternal plasma samples collected before and after amniocentesis
Authors: Bussani Cecilia , Di Tommaso Mariarosaria , Cioni Riccardo , Pasquini Lucia , Quitadamo Laura , Scarselli Gianfranco 
Published: March 2011

AbstractAims:  The aim of this study was to evaluate possible procedure‐related variations in the levels of cell‐free fetal DNA (fDNA) in maternal plasma of women undergoing genetic amniocentesis.Materials and Methods:  Blood samples were collected at 16–18 weeks' gestation from 33 pregnant women attending the Fetal Medicine Unit for genetic amniocentesis. For each woman, two blood samples were obtained: the first immediately before amniocentesis and the second one 15 min after the procedure. A real‐time quantitative polymerase chain reaction assay, using primers for SRY and beta‐globin genes, was used to assess fDNA concentrations in maternal plasma. A Wilcoxon signed‐rank test was used for statistical analysis.Results:  The karyotype on cultured amniocytes showed that 15 out of 33 women had a male fetus. Real‐time quantitative polymerase chain reaction results, on maternal plasma sample pairs from known male pregnancies, showed no significant variations of fDNA correlated to amniocentesis (P = 0.394).Conclusions:  Our preliminary study suggests that amniocentesis, although invasive, could be associated with minimal, if any, disruption at the fetal–maternal interface, as revealed by the lack of substantial modifications of fDNA levels in maternal circulation.