bluuebunny/crossref_metadata_2025_split huggingface dataset:
Angiogenesis in cancer
Authors: Poettler M. , Prager G. W. 
Published: August 2011

SummaryEtiological concepts on cancer development, malignant growth and tumour propagation have undergone a revolutionary development during recent years: Among other aspects, the discovery of angiogenesis – the growth of new blood vessels from pre-existing vasculature – as a key element in the pathogenesis of malignancy has opened an abundance of biologic insights and subsequent therapeutic options, which have led to improved prognosis in many cancers including those originating from colon, lung, breast and kidney. Thereby, targeting the major pro-angiogenic stimulus vascular endothelial growth factor (VEGF) became the focus for therapeutic interventions. However, the use of VEGF-targeting drugs has been shown to be of limited efficacy, which might lie in the fact that tumor angiogenesis is mediated by a variety of different subcellular systems.This review focuses on the basic mechanisms involved in angiogenesis, which potentially represent novel targets for pharmacological agents in the treatment of malignancies.
Two Distinct Origins of Highly Localized Luminescent Centers within InGaN/GaN Quantum‐Well Light‐Emitting Diodes
Authors: De Suman , Layek Arunasish , Raja Archana , Kadir Abdul , Gokhale Mahesh R. , Bhattacharya Arnab , Dhar Subhabrata , Chowdhury Arindam 
Published: August 2011

AbstractThe high light‐output efficiencies of InxGa1‐xN quantum‐well (QW)‐based light‐emitting diodes (LEDs) even in presence of a large number of nonradiative recombination centers (such as dislocations) has been explained by localization of carriers in radiative potential traps, the origins of which still remain unclear. To provide insights on the highly efficient radiative traps, spectrally resolved photoluminescence (PL) microscopy has been performed on green‐light‐emitting In0.22Ga0.78N QW LEDs, by selectively generating carriers in the alloy layers. PL imaging shows the presence of numerous inhomogeneously distributed low‐band‐gap traps with diverse radiative intensities. PL spectroscopy of a statistically relevant number of individual traps reveals a clear bimodal distribution in terms of both band‐gap energies and radiative recombination efficiencies, indicating the presence of two distinct classes of carrier localization centers within the same QW sample. Disparity in their relative surface coverage and photoemission “blinking” characteristics suggests that the deep traps originate from local compositional fluctuations of indium within the alloy, while the shallow traps arise from nanometer‐scale thickness variations of the active layers. This is further supported by Poisson–Schrödinger self‐consistent calculations and implies that radiative traps formed due to both local indium content and interface‐morphology‐related heterogeneities can coexist within the same QW sample.
A Novel Entry to Spirofurooxindoles Involving Tandem Dearomatization of Furan Ring and Intramolecular Friedel– Crafts Reaction
Authors: Yin Biao‐Lin , Lai Jin‐Qiang , Zhang Ze‐Ren , Jiang Huan‐Feng 
Published: August 2011

AbstractA copper sulfate pentahydrate‐catalyzed intramolecular Friedel–Crafts reaction using an oxocarbenium species derived from a furan ring as the alkylating agent was developed for the first time. By using this protocol, spirofurooxindoles 9 with multi‐reactive sites were synthesized simply and concisely. In addition, selective hydrogenation of the endo‐cyclic double bond and full hydrogenation of the endo and exo‐cyclic double bonds of spirofurooxindoles 9 provided spirofurooxindoles 11 and 12, respectively.
Characteristics and outcome of immune thrombocytopenia in elderly: Results from a single center case‐controlled study
Authors: Michel Marc , Rauzy Odile Beyne , Thoraval Francoise Roudot , Languille Laetitia , Khellaf Mehdi , Bierling Philippe , Godeau Bertrand 
Published: August 2011

AbstractThe management of ITP in elderly raises several questions that have not been fully addressed in the literature. To assess the impact of ITP in elderly, a case‐control study was performed. The main characteristics at onset and the outcome of ITP in 55 patients aged of 70 years and above (cases) were compared with those of 97 younger adults (controls) seen at the same tertiary referral institution. The mean age at diagnosis was respectively 77.8±6.1 years (cases) and 40.3±14.9 years (controls). While the median platelet count at time of diagnosis was not significantly different in cases and controls (6×109/L, range: 2–26 versus 12×109/L: 5–21.5), bleeding symptoms were more frequent in cases (82%) than in the controls (68%, p=0.07), and the median bleeding score was significantly higher in elderly (p=0.001). The rate of treatment‐related adverse events was more than twofold higher in elderly patients and the mean cumulative duration of hospital stay for ITP during the follow‐up period was much longer when compared to the controls (p<0.0001). Three ITP‐related deaths (5.4%) including 1 from intracranial hemorrhage occurred in the cases but none in the controls. In conclusion, this study confirms that at equivalent platelet count, ITP has a greater impact in elderly. Am. J. Hematol. 2011. © 2011 Wiley‐Liss, Inc.
Infant and child diet in Neolithic hunter‐fisher‐gatherers from cis‐baikal, Siberia: Intra‐long bone stable nitrogen and carbon isotope ratios
Authors: Waters‐Rist Andrea L. , Bazaliiskii Vladimir I. , Weber Andrzej W. , Katzenberg M. Anne 
Published: August 2011

AbstractAnalysis of stable nitrogen and carbon isotopes (δ15N and δ13C) from subadults and adults allows for assessment of age‐related dietary changes, including breastfeeding and weaning, and adoption of an adult diet. In one of the first studies of hunter‐fisher‐gatherer subadults from Eurasia, three Neolithic (8,800‐5,200 calBP) mortuary sites from southwestern Siberia are analyzed to evaluate hypothesized differences in weaning age between Early versus Late Neolithic groups. An intra‐individual sampling methodology is used to compare bone formed at different ages. Collagen samples (n = 143) from three different growth areas of long bones—the proximal metaphysis, diaphysis, and distal metaphysis—were obtained from 49 subadults aged birth to 10 years. In infants (birth to 3 years, n = 23) contrasting the δ15N values of the metaphysis, which contains newer bone, to the δ15N values of the diaphysis, which contains older bone, permits a more precise determination of breastfeeding‐weaning status. In Early and Late Neolithic groups breast milk was the major protein source until the age of 2–3 years. However, there are differences in the age of weaning completion and duration: Early Neolithic groups weaned their infants at a later age and over a shorter amount of time. Differences may have affected infant morbidity and mortality, and female fecundity and inter‐birth intervals. Stable isotope values in older subadults (4–10 years, n = 26) do not differ from adults suggesting the absence of age‐based food allocation. Am J Phys Anthropol, 2011. © 2011 Wiley‐Liss, Inc.
Functionalization of some benzylthioarylboronic acids by benzylic lithiation of their N‐butyldiethanolamine esters or lithium (triisopropoxy)borates
Authors: Durka Krzysztof , Kliś Tomasz , Serwatowski Janusz , Woźniak Krzysztof 
Published: August 2011

AbstractThe reaction of benzylthioarylboronic acids protected as N‐butyldiethanolamine esters or as triisopropoxyborates with organolithium bases or lithium diisopropylamide (LDA) has been investigated. The benzylic lithiation occurs selectively using LDA at − 68 °C. The stability of the resultant borio‐lithio intermediates is strongly influenced by the position of the boron atom in the phenyl ring. The reaction with various electrophiles affords new arylboronic acids substituted in the benzylic position. Copyright © 2011 John Wiley & Sons, Ltd.
Nano‐sized silica supported Me2Si(Ind)2ZrCl2/MAO catalyst for ethylene polymerization
Authors: Li Kuo‐Tseng , Li Cheng‐Yu 
Published: August 2011

AbstractNano‐sized and micro‐sized silica particles were used to support a zirconocene catalyst [racemic‐dimethylsilbis(1‐indenyl)zirconium dichloride], with methylaluminoxane as a cocatalyst. The resulting catalyst was used to catalyze the polymerization of ethylene in the temperature range of 40–70°C. Polyethylene samples produced were characterized with scanning electron microscopy (SEM), X‐ray diffraction (XRD), differential scanning calorimetry (DSC), and gel permeation chromatography (GPC). Nano‐sized catalyst exhibited better ethylene polymerization activity than micro‐sized catalyst. At the optimum temperature of 60°C, nano‐sized catalyst's activity was two times the micro‐sized catalyst's activity. Polymers obtained with nano‐sized catalyst had higher molecular weight (based on GPC measurements) and higher crystallinity (based on XRD and DSC measurements) than those obtained with micro‐sized catalyst. The better performances of nano‐sized catalyst were attributed to its large external surface area and its absence of internal diffusion resistance. SEM indicated that polymer morphology contained discrete tiny particles with thin long fiberous interlamellar links. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Monomer cast polyamide 6 composites and their treatment with high‐energy electrons
Authors: Engelmann G. , Gohs U. , Ganster J. 
Published: August 2011

AbstractAt first, the impact of selected spherically structured nanofillers made of different polar materials (carbon, silicon carbide, surface‐modified silica, 2 wt % each) on mechanical properties of monomer cast polyamide 6 (MCPA6) was examined. Only the low‐polar carbon‐based nanofiller showed an average particle size below 100 nm in the liquid phase before polymerization was initiated. With regard to neat MCPA6, mechanical properties of the composite loaded with the carbon nanoparticles like tensile strength, Young's modulus, and heat distortion temperature could be improved by 6.4%, 13.5%, and 27.5%, respectively. The efficiency of carbon as filler material for MCPA6 was also shown for carbon short‐cut fibers. A fiber content of 15% improved tensile strength from 78 to 93 MPa (19%) and Young's modulus could be doubled from 2660 MPa to nearly 5300 MPa. Regardless of the improved mechanical properties, the composites showed reduced degrees of crystallinity. Therefore, electron beam irradiation was applied to crosslink the polymer chains as an alternative to improve material properties. Crosslinking was supported by the application of a curing agent (CA). Two strategies for crosslinking experiments were tested: (1) Irradiation of CA‐containing neat MCPA6 to find the most effective dose and subsequent treatment of the composites under this special condition; (2) Optimization of the properties by irradiation of the composites itself at graduated dose values. The second way was more convenient and showed, with regard to the composites without CA, improvements of tensile strength and Young's modulus of 6% each. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Core‐shell ZrO2/PMMA composites via dispersion polymerization in supercritical fluid: Synthesis, characterization and mechanism
Authors: Haldorai Yuvaraj , Zong Tongqiang , Shim Jae‐Jin 
Published: August 2011

AbstractZirconia (ZrO2) particles of average size 200 nm were synthesized by sol–gel method and formation of composites with poly(methyl methacrylate) (PMMA) via in situ radical dispersion polymerization in supercritical carbon dioxide (scCO2) using a commercially available stabilizer poly(dimethylsiloxane)‐g‐pyrrolidone carboxylic acid (Monosil PCA). ZrO2 particles were first surface‐modified by the silane coupling agent methacryloxypropyltrimethoxysilane (MPTMS), which is capable of copolymerizing with methyl methacrylate (MMA) and provide a reactive CC bond. SEM results revealed uniform morphological characteristics of the composite materials and good dispersions of the ZrO2 particles. TEM analysis confirmed the core–shell morphology. The incorporation of ZrO2 particles in the composites was endorsed by FT‐IR. The composites were also confirmed by TGA and XRD. The hybrid composites possess interesting thermal and optical transparency characteristics because of the uniform incorporation of ZrO2 particles in the polymer matrix. In principle, this simple and environmentally friendly synthetic procedure can be employed to prepare other inorganic oxide containing polymer composites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Electroluminescence properties of poly(3‐hexylthiophene)–cadmium sulfide nanoparticles grown in situ
Authors: Borriello C. , Masala S. , Bizzarro V. , Nenna G. , Re M. , Pesce E. , Minarini C. , Di Luccio T. 
Published: August 2011

AbstractIn this work, a simple approach to prepare luminescent poly(3‐hexylthiophene)–CdS nanocomposites to be employed in organic light emitting devices (OLED) devices is reported. The nucleation and growth of CdS nanoparticles were obtained by the thermolysis of a single Cd and S precursor dispersed in the polymer at three different temperatures of annealing: 240, 265, and 300°C. In this way, it was possible to compare the properties of nanocomposites containing nanoparticles with different sizes. X‐ray diffraction and transmission electron microscopy analyses confirmed the formation of CdS nanoparticles and gave information about the size, distribution, and morphology of the nanoparticles; monodispersive and very small nanoparticles with diameters below 2.5 nm were obtained at 240°C. The application of such nanocomposites as emitting layers in OLED devices is discussed. Enhanced electrooptical properties were observed for the device containing the nanocomposite annealed at 240°C with respect to the pure polymer based device. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Microstructuring of polymer films by inkjet etching
Authors: Grimaldi I. A. , De Girolamo Del Mauro A. , Nenna G. , Loffredo F. , Minarini C. , Villani F. 
Published: August 2011

AbstractThe inkjet printing (IJP) technique is generally used as tool for positioning small quantities of a liquid material on a target substrate. An interesting application of IJP is inkjet etching that consists of the deposition of drops of solvent or solvent mixtures onto a soluble polymer layer. This technique allows one to structure the polymer film and to change the shape, from concave to convex, by varying the mixing ratio of the solvents. In this work, the structuring of some polymeric layers (polyimide and polystyrene) by solvents [N‐methyl‐2‐pyrrolidone (NMP) and toluene (TOL)] and a solvent mixture (TOL–NMP) at different mixing ratios were studied, and the effect of the printing parameters on the microstructural profile was investigated. Some applications in optoelectronic devices are described. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Pore structure and swelling behavior of porous hydrogels prepared via a thermal reverse‐casting technique
Authors: Salerno Aurelio , Borzacchiello Rossella , Netti Paolo A. 
Published: August 2011

AbstractIn this work, we investigated the design and fabrication of porous polyacrylamide hydrogels via a thermal reverse‐casting technique. The porous hydrogels were prepared by the free‐radical crosslinking polymerization of the monomer solution within the space of an agarose gel, which after the setting of the chemical gel, was removed to allow for the formation of an interconnected porosity pathway. Two different agarose/monomer solution ratios were selected to modulate the porosity of the hydrogels, and the as‐obtained samples were characterized in terms of their chemical structure, morphology, thermal properties, and swelling behavior in different ionic strength solutions. The results of this study demonstrate that the reverse‐casting process enhanced the solvent‐retaining capability of the hydrogels and that their swelling ratio increased with increasing concentration of the agarose solution in the initial formulation. All of these results finally demonstrate that the pore structure features played a key role in defining the swelling behavior of the hydrogels. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Effect of diisocyanate structure on the properties and microstructure of polyurethanes based on polyols derived from renewable resources
Authors: Corcuera Ma. Angeles , Rueda Lorena , Saralegui Ainara , Martín Ma. Dolores , Fernández‐d'Arlas Borja , Mondragon Iñaki , Eceiza Arantxa 
Published: August 2011

AbstractPolyols derived from renewable resources are good candidates for obtaining segmented polyurethane (PU) elastomers. Diisocyanates with different chemical structures, aliphatic and aromatic, were used to synthesize PU elastomers with different hard‐segment (HS) contents by a two‐step polymerization procedure. Microphase separation and thermal stability were studied with attenuated total reflection Fourier transform infrared spectroscopy, differential scanning calorimetry, and thermogravimetric analysis. The analysis of H‐bonded and non‐H‐bonded urethane carbonyl stretching vibration in the amide I region, the glass‐transition temperatures of the soft segments and HSs, and the melting temperature and enthalpies of the HSs revealed that aliphatic diisocyanate based PUs presented a higher phase separation degree and higher HS crystallinity and also a superior thermal stability to the aromatic diisocyanate‐based PUs. The aromatic diisocyanate‐based PU presented a higher ductility, higher tensile strength, and lower modulus than aliphatic diisocyanate‐based PU for the same HS content because of the different morphology that they presented. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Preparation, characterization, and release behavior of nanocomposite microparticles based on polystyrene and different layered silicates
Authors: Scarfato Paola , Russo Pietro , Acierno Domenico 
Published: August 2011

AbstractA microparticulated, organic–inorganic hybrid system, useful as an active agent carrier, was successfully developed with an emulsification/solvent evaporation method. The system consisted of nanostructured polystyrene microparticles containing different silicates as nanosized fillers and benzophenone (BP) as a model active substance. The adopted preparation procedure gave high yields of microparticles, which displayed regular geometry and high encapsulation efficiency of the active agent. X‐ray diffraction measurements showed that all of the hybrid systems had a polymer–silicate intercalated morphology and the BP was molecularly dispersed in the microspheres. Moreover, preliminary in vitro release tests evidenced that the inclusion of the nanodispersed silicates into the polymer matrix significantly modified the release behavior of BP, depending on the silicate type. Therefore, the nanocomposite microparticles are of great potential in the field of controlled release. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Altering the onset of cocontinuity in nanocomposite immiscible blends by acting on the melt‐compounding procedure
Authors: Filippone G. , Acierno D. 
Published: August 2011

AbstractThe addition of nanoparticles to polymer systems with an existing phase‐separated morphology, such as polymer blends, represents an innovative approach to controlling the microstructure and, hence, the macroscopic properties of the material. During the melt mixing of the constituents, the particles migrate toward specific regions of the material and are driven by more favorable thermodynamic interactions. Kinetic effects related to the high viscosity of the polymer melts, however, may lead to nonequilibrium morphologies. This makes the mixing procedure crucial for controlling the space distribution of the filler and, hence, the microstructure of the blend and its final properties. We focused on this topic by investigating the effect of the sequence of addition of the constituents in blends of polystyrene and polyamide 6 filled with an organoclay prepared by melt compounding. We show that the mixing procedure could bring about alterations in the onset of cocontinuity, which could be exploited to enhance the high‐temperature mechanical strength of the blends. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Measurement of the interfacial attraction between graphene oxide sheets and the polymer in a nanocomposite
Authors: Kranbuehl D. E. , Cai M. , Glover A. J. , Schniepp H. C. 
Published: August 2011

AbstractThe objective of this work was to characterize and, thereby, achieve a fundamental scientific understanding at the molecular level of the relationship of the intermolecular forces measured at the nanoscale between an individual nanoparticle and a polymer. In this study, we developed a method to directly characterize and measure the relative strength of the interfacial attractive forces between graphene oxide (GO) nanoparticles and the polymer matrix on the nanoscale using atomic force microscopy techniques to evaluate individual particles. The method was successfully applied to study the interfacial attractive forces in GO–polymer nanocomposites. Two polymers [poly(methyl methacrylate) and poly(vinyl alcohol)] were studied. The results support that this method is capable of characterizing the interfacial attractive forces directly at the nanoscale. The method can be applied to other nanoparticle–macromolecular systems, allowing the determination of the interaction strength between nanoparticles and the macromolecular material. This information paves the way to characterize the relationship between interfacial forces at the nanometer level to a nanocomposite's performance properties. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Modeling of the isobaric and isothermal glass transitions of polystyrene
Authors: Grassia Luigi , Carbone Maria Giovanna Pastore , D'Amore Alberto 
Published: August 2011

AbstractThe scaling law for relaxation times (τ's) recently proposed by Casalini and Roland was used in the framework of Kovacs, Aklonis, Hutchinson, and Ramos phenomenological theory. With this approach, it was shown that both the isobaric and the isothermal glass transitions of polystyrene can be reliably predicted with only two fitting parameters, namely, τ in the reference state and the fractional exponent that describes the dispersion of the α relaxation. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Silicone‐rubber‐based tactile sensors for the measurement of normal and tangential components of the contact force
Authors: D'Amore Alberto , De Maria Giuseppe , Grassia Luigi , Natale Ciro , Pirozzi Salvatore 
Published: August 2011

AbstractThis article presents the developmental process of a new tactile sensor. The sensor was based on the use of light‐emitting diode (LED) phototransistor couples and a silicone rubber layer positioned above the optoelectronics devices. The optoelectronic components were organized in a matrix structure. For each couple, the LED illuminated the reflective surface, which coincided with the bottom facet of the deformable layer. Practically, the deformable layer transduced an external force into a displacement variation of its bottom facet through its stiffness. An external force applied to the deformable layer produced local variations of the bottom surface of the elastic material, and the couples of optical devices measured the vertical deformations in a discrete number of points. In particular, these vertical displacements produced a variation of the reflected light intensity and, accordingly, of the photocurrent measured by the photodetector. The realized prototype was designed and optimized through finite element analysis. A calibration procedure is also presented, whose results demonstrate the ability of the sensor to reconstruct the contact point and also the normal and tangential components of the contact force. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011