bluuebunny/crossref_metadata_2025_split huggingface dataset:
Climatology of precipitation over the Iberian Central System mountain range
Authors: Durán L. , Sánchez E. , Yagüe C. 
Published: October 2012

ABSTRACTAn analysis of the observed precipitation for the last 22 years (1989–2010) over Sierra de Guadarrama (centre of Iberian Central System) has been performed. Since this area has received less attention compared with other mountain ranges in Europe and the rest of the world, an exhaustive compilation of literature on precipitation main characteristics on Central Iberia (SW Europe) has been done. The analysis, based on both rain gauges and reanalysis, is focused on the search of the atmospheric mechanisms and moisture sources that lead to precipitation. Also, emphasis has been made in the role played by orography conditioning, the complex spatial patterns observed in the region. This work shows how it behaves as an orographic island that rises over an extensive plateau with a marked Atlantic forcing despite the distance these masses have to travel inlands, with mostly of wet days due to advection of moisture from the ocean and small amount of rain due to local sources of humidity and convective precipitation. It also shows the great enhancement of precipitation caused by the range due to orographic precipitation and the big differences found at the downwind and upwind side of the mountain leading to marked spatial patterns seasonal dependent, complex vertical gradients and high wind direction dependency. Finally, statistically significant mean conditions of variables related with orographic precipitation are given in order to be used as boundary conditions for orographic precipitation modelling exercises. This works gives a climatic framework for future precipitation assessments that could be conducted combining measurements and such models.
Follow‐up of early stage melanoma: Specialist clinician perspectives on the functions of follow‐up and implications for extending follow‐up intervals
Authors: Rychetnik Lucie , McCaffery Kirsten , Morton Rachael L , Thompson John F , Menzies Scott W , Irwig Les 
Published: October 2012

AbstractBackgroundThere is limited evidence on the relative effectiveness of different follow‐up schedules for patients with AJCC stage I or II melanoma, but less frequent follow‐up than is currently recommended has been proposed.ObjectivesTo describe melanoma clinicians' perspectives on the functions of follow‐up, factors that influence follow‐up intervals, and important considerations for extending intervals.MethodsQualitative interviews with 16 clinicians (surgical oncologists, dermatologists, melanoma unit physicians) who conduct follow‐up at two of Australia's largest specialist centers.ResultsFollow‐up is conducted for early detection of recurrences or new primary melanomas, to manage patient anxiety, support patient self‐care, and as part of shared care. Recommended intervals are based on guidelines but account for each patient's clinical risk profile, level of anxiety, patient education requirements, capacity to engage in skin self‐examination, and how the clinician prefers to manage any suspicious lesions.ConclusionsTo revise guidelines and implement change it is important to understand the rationale underpinning existing practice. Extended follow‐up intervals for early stage melanoma are more likely to be adopted after the first year when patients are less anxious and sufficiently prepared to conduct self‐examination. Clinicians may retain existing schedules for highly anxious patients or those unable to examine themselves. J. Surg. Oncol. 2013;107:463–468. © 2012 Wiley Periodicals, Inc.
Tunable Surface Nanoporosity by Electropolymerization of N‐Alkyl‐3,4‐ethylenedioxypyrroles With Different Alkyl Chain Lengths
Authors: Darmanin Thierry , Guittard Frédéric 
Published: October 2012

AbstractThe tuning of the surface morphology is crucial in the development of superhydrophobic surfaces with various wetting properties. Here, we report the synthesis and electrodeposition of poly(3,4‐ethylenedioxypyrrole) (PEDOP) derivatives containing hydrocarbon chains (ethyl to tetradecyl). Surprisingly, the alkyl chain length has a very important influence on the surface morphology and as a consequence on the water‐repellency properties. The amount of the nanoporosity and the water‐repellency properties can be controlled with alkyl chain length. Moreover, it seems the presence of surface nanoporosity is in correlation with the steric hindrances induced by the alkyl chains during the electrodeposition. This paper uses bioinspired approaches (fluorocarbon free) to reach superhydrophobic surfaces.
Covalent Attachment of Gold Nanoparticles to Surfaces and Polymeric Substrates Using UV Light
Authors: Roth Peter J. , Theato Patrick 
Published: October 2012

AbstractUniform benzophenone‐covered AuNP (Bph‐AuNP) were prepared in a two‐phase ethyl acetate/water reduction of auric acid employing a benzophenone‐functionalized disulfide. Upon UV irradiation, the benzophenone carbonyl bond was excited allowing for insertion into a nearby C–H bond and thus a covalent attachment of the AuNP onto a substrate exhibiting C–H bonds. Using this technique, polycarbonate–gold core–shell particles were easily obtained, providing a simple synthetic pathway toward AuNP hybrids with polycondensation polymers. Bph‐AuNP were also covalently attached to alkylated silica microspheres or cellulose paper. UV irradiation through a photo mask enabled a photolithographic surface patterning.
Evaluation of Spectroscopic and Morphological Properties of PMMA Modified with ILs
Authors: de Oliveira Viviane B. , Pereira Nizamara S. , Andrade Carlos Kleber Z. , Sales Maria José A. 
Published: October 2012

AbstractSummary: In recent years, an important class of new compounds, ionic liquids (ILs), has been investigated as additives for polymers. In this work, we carried out the synthesis of 4 different ILs: 1‐butyl‐3‐methylimidazolium tetrafluoroborate (BMIM.BF4), 1‐butyl‐3‐methylimidazolium hexafluorophosphate (BMIM.PF6), and the chiral ILs acetyl‐(−)menthol‐1‐buthylimidazole tetrafluoroborate ([amebim]BF4) and acetyl‐(−)menthol‐1‐buthylimidazole hexafluorophosphate ([amebim]PF6). These ILs were added to poly(methyl methacrylate) (PMMA) in 10, 20 and 30% ratios by weight and the ILs, PMMA and the obtained materials (PMMA:ILs) were characterized by infrared, visible spectroscopy and atomic force microscope. The ILs added to PMMA did not provide significant changes in the infrared spectra, compared to pure PMMA. However, the absorption spectra in the visible region of the PMMA:ILs materials showed differences, compared to the spectrum of pure PMMA.
Conductive Nanocomposites Based on Cellulose Nanofibrils Coated with Polyaniline‐DBSA Via In Situ Polymerization
Authors: Silva Michael J. , Sanches Alex O. , Malmonge Luiz F. , Medeiros Eliton S. , Rosa Morsyleide F. , McMahan Colleen M. , Malmonge José A. 
Published: October 2012

AbstractSummary: Cellulose nanofibrils (CNF) were extracted by acid hydrolysis from cotton microfibrils and nanocomposites with polyaniline doped with dodecyl benzenesulphonic acid (PANI‐DBSA) were obtained by in situ polymerization of aniline onto CNF. The ratios between DBSA to aniline and aniline to oxidant were varied in situ and the nanocomposites characterized by four probe DC electrical conductivity, ultraviolet‐visible‐near infrared (UV‐Vis ‐ NIR) and Fourier‐transform infrared (FTIR) spectroscopies and X‐ray diffraction (XRD). FTIR and UV‐Vis/NIR characterization confirmed the polymerization of PANI onto CNF surfaces. Electrical conductivity of about 10−1 S/cm was achieved for the composites; conductivity was mostly independent of DBSA/aniline (between 2 and 4) and aniline/oxidant (between 1 and 5) molar ratios. X‐ray patterns of the samples showed crystalline peaks characteristic of cellulose I for CNF samples, and a mixture of both characteristic peaks of PANI and CNF for the nanocomposites. Field emission scanning electron microscopy (FESEM) characterization corroborated the abovementioned results showing that PANI coated the surface of the nanofibrils.
Effect of Organoclay Mixture on the Rheological Properties of ABS‐Clay Nanocomposites
Authors: Galvan Danieli , Carneiro Fábio , Mazzucco Mateus , Bartoli Julio Roberto , d'Ávila Marcos Akira , Morales Ana Rita , Fernandes Elizabeth Grillo 
Published: October 2012

AbstractSummary: In this work, poly(acrylonitrile‐butadiene‐styrene) (ABS) and different organically modified montmorillonite clay nanocomposites were prepared by melt intercalation in a co‐rotating twin screw extruder. The influence of the screw torque during processing and of the mixture of the modified organoclays in the intercalation/exfoliation of the clay in the polymeric matrix was evaluated through low angle X‐ray diffraction range and capillary and parallel plate‐plate rheometry.
Preparation and Characterization of PVA Hidrogels Nanofibers
Authors: Almeida Rosemeire S. , Rodriguez Geraldine N. , Lima Lonetá L. , Bavaresco Vanessa P. , Zavaglia Cecília A. C. , d'Ávila Marcos A. 
Published: October 2012

AbstractSummary:Poly(vinyl alcohol) (PVA) is a biomaterial that has interesting features for applications in soft tissue replacement due to its similarities in the mechanical properties of such tissues. This paper describes the preparation and characterization of PVA fibers obtained by electrospinning and crosslinked with potassium persulfate as thermoinitiator. These PVA fibers were characterized by Scanning Electron Microscopy (SEM) and Optical Microscopy (OM) to analyze the morphology of the spun samples. Finally, Fourier Transform Infrared Spectroscopy (FTIR) and differential scanning calorimetry (DSC) were performed and the results showed that the biomaterial was partially cross‐linked, which indicates a potential use for dermal regeneration applications. The morphology of the fibers indicated that structural changes occurred in the biomaterial after thermal crosslinking.
Evaluation of the Biocidal Capacity of Hypercrosslinked Resins Containing Dithiocarbamate Groups
Authors: Costa Luciana C. , Marques Mônica R. C. , Tiosso Rodrigo B. , Cantarim Jefferson P. , Merçon Fábio 
Published: October 2012

AbstractSummary: In this study we report both the development of dithiocarbamate resins from the commercial hypercrosslinked resin MN‐250 and the evaluation of the biocidal capacity of this material against E. coli ATCC25922 suspensions. The preparation of dithiocarbamate resins followed a synthetic pathway based on nitration of resins, reduction of nitro groups and reaction with CS2 in an alkaline medium. The biocidal capacity was evaluated by means of elution of E. coli suspensions (103–107 cells/mL) through columns containing the resin and plating on LB nutrient medium solidified with Bacto agar. We can conclude that hypercrosslinked resins with dithiocarbamate groups have potential biocidal action.
Fluorescent‐Magnetic Nanostructures Based on Polymer‐Quantum Dots Conjugates
Authors: da Silva Maria I. N. , Mansur Alexandra A. P. , Schatkoski Vanessa , Krambrock Klaus W. H. , González Juan , Mansur Herman S. 
Published: October 2012

AbstractSummary: In this study it is presented the synthesis and the characterization of Fluorescent‐Magnetic Nanostructures based on polymer‐quantum dots conjugates. Polyvinyl alcohol (PVA) was used as the capping‐ligand for the preparation of CdxMn1‐xS semiconductor nanocrystals via aqueous colloidal chemistry. Different substitution ratios of Cd2+ by Mn+2 ions were investigated aiming at the formation of stable nanoparticles with photo‐luminescent and semi‐magnetic properties. UV‐visible spectroscopy (UV‐vis), photoluminescence spectroscopy (PL), Electric Paramagnetic Resonance Spectroscopy (EPR), and transmission electron microscopy (TEM) were used to characterize the formation and the relative stability of CdxMn1‐xS nanoparticles. The results have showed the influence of the Mn2+partially replacing Cd2+ in the optical behavior of the quantum dots (QDs) produced. In addition, the CdxMn1‐xS QDs have evidenced luminescent and semi‐magnetic properties. Thus, the biocompatible water‐soluble polymer was effective as ligand for synthesizing and stabilizing QDs conjugates with properties allowing them to be potentially applied as imaging and labeling probes in the biomedical field.
Influence of Organophilic Ammonium‐Free Nanoclay Incorporation on Mechanical Properties and Biodegradability of Biodegradable Polyester
Authors: Morita Reinaldo Y. , Richart Fábio S. , Barbosa Ronilson V. , Munaro Marilda , Kloss Juliana R. 
Published: October 2012

AbstractSummary: Disposal of petroleum‐derived polymers is a growing global environmental problem of alarming proportions, which has increased interest in the use and production of biodegradable materials. In addition to biodegradation, investment in research and development in the nanotechnology area is also significant. This study evaluated the effect of incorporation of an organophilic nanoclay ammonium‐free salt (Novaclay™) on the mechanical properties and biodegradation of a biodegradable polyester (Ecoflex®), according to ASTM G 160. Ecoflex with and without incorporated Novaclay was characterized before and after biodegradation in organically enriched soil for up to 180 days, by visual analysis, optical microscopy, weight loss, differential scanning calorimetry, dynamic mechanical analysis, mechanical testing, and scanning electron microscopy. The pure Ecoflex and the Ecoflex/Novaclay nanocomposite were partially biodegraded by the method used, and showed changes in their morphological and mechanical properties.
Statistical Experimental Design for Obtaining Nanocellulose from Curaua Fiber
Authors: Lunz Juliana N. , Cordeiro Suellem B. , Mota José Carlos F. , Marques Maria F. V. 
Published: October 2012

AbstractSummary: This study focuses on the methodology to obtain nanocellulose from vegetal fibers. An experimental planning was carried out for the treatment of curaua fibers and parameters were estimated, having the concentration of H2SO4, hydrolysis time, reaction temperature and time of applied sonication as independent variables for further statistical analysis. According to the estimated parameters, the statistically significant effects were determined for the process of obtaining nanocellulose. With the results obtained from the thermogravimetric analysis (TGA) it was observed that certain conditions led to cellulose with degradation temperatures near or even above that of the untreated cellulose fibers. The crystallinity index (IC) obtained after fiber treatment (by X‐ray diffraction technique) was higher than that of the pure fiber. Treatments with high acid concentrations led to higher IC. After the statistical experimental design, mixtures of polypropylene with fibers prepared after different treatments were performed in a mini‐extruder. It was possible to observe a sharp increase in the mechanical properties through the dynamic mechanical thermal analysis (DMTA).
Preparation and Characterization of Nanocomposites of Carboxymethyl Cellulose Reinforced with Cellulose Nanocrystals
Authors: Neto Wilson Pires Flauzino , Silvério Hudson Alves , Vieira Júlia Graciele , da Costa e Silva Alves Héden , Pasquini Daniel , de Assunção Rosana Maria Nascimento , Dantas Noélio Oliveira 
Published: October 2012

AbstractSummary: Cellulose nanocrystals (CNC) were extracted from Kraft pulp of Eucalyptus urograndis. The CNC were isolated by acid hydrolysis with H2SO4 64% (w/w) solution, for 20 minutes at 45 °C. The morphology and crystallinity of the CNC were investigated by atomic force microscopy (AFM) and X‐ray diffraction (XRD), respectively. The AFM image supports the evidence for the development of crystals of cellulose in nanometric scale. These nanoparticles were used as reinforcement material in carboxymethyl cellulose (CMC) matrix. Nanocomposites films were prepared by casting. The nanocomposites were characterized by thermal (TGA) and mechanical (DMA) analyses. A large reinforcing effect of the filler was observed. The tensile strength of nanocomposites was significantly improved by 107%, the elongation at break decreased by 48% and the thermal resistance increased slightly. The improvements in thermo‐mechanical properties suggest a close association between filler and matrix.
Bifurcation Analysis of the Bulk Propylene Polymerization in the LIPP Process
Authors: da Silva Rosa Isaias , Melo Príamo A. , Pinto José Carlos 
Published: October 2012

AbstractSummary: A dynamic model is built to describe the bulk propylene polymerization in stirred tank reactors (LIPP process), assuming that catalyst deactivation takes place and that the reactor temperature must be controlled with the help of reflux condensers and external heat exchangers. Simulation results show that the dynamic behavior of the LIPP process can be much more complex than described previously, when catalyst deactivation and the performance of the real temperature controller are taken into consideration. Particularly, it is shown that chaotic behavior can be observed in very wide ranges of operation conditions when the more realistic operation conditions are considered.
In Situ Incorporation of Doxorubicin in Copolymer Particles During Suspension Polymerization
Authors: Oliveira Marco Antonio M. , Melo Príamo A. , Nele Márcio , Pinto José Carlos 
Published: October 2012

AbstractSummary: This work reports the kinetic behavior and the molecular properties of obtained copolymers during vinyl acetate and methyl methacrylate suspension copolymerizations in presence of doxorubicin. The obtained spherical particles are intended for use as chemoembolization agents. It is shown that the presence of doxorubicin in the reaction medium promotes significant changes in the copolymerization kinetics and final molecular weight averages of the polymer product.
Preparation of PMMA Nanoparticles Loaded with Benzophenone‐3 through Miniemulsion Polymerization
Authors: Lorca Bárbara S.S. , Bessa Evelin S. , Nele Marcio , Santos Elisabete P. , Pinto José Carlos 
Published: October 2012

AbstractSummary: The present paper analyzes the production of poly(methyl methacrylate) – PMMA – nanoparticles loaded with benzophenone‐3 through miniemulsion polymerization. The obtained product is homogeneous and stable, allowing for preparation of photo‐protective formulations. It is observed in particular that bezophenone‐3 interacts with the reacting system, promoting the growth of the PMMA chains produced in miniemulsion.
Concentration of Whey Proteins by Using Temperature‐Sensitive Polymer Gel Poly(N‐isopropylacrylamide)
Authors: Tavares Gabriela C. , Silva Maria Elisa S. R. , Sousa Ricardo G. , Freitas Roberto F. S. 
Published: October 2012

AbstractSummary: In this work, the use of a temperature‐sensitive polymer gel, poly(N‐isopropylacrylamide), for the concentration of whey proteins was studied. The studied variables were: gel mass/solution volume ratio and concentration temperature. The concentration percentage and the selectivity were determined. The gel 20 × 5 (20% w/w total monomer/solution and 5% w/w crosslinking agent/total monomer), contacted with whey proteins solutions, at 5 °C and at 20 °C, was capable of concentrating the solution, in protein, from 10 to 33%, depending on the gel mass/solution volume ratio. The separation efficiencies, for the different studied systems, varied from around 40 to 80%. The results were discussed in the context of gels thermodynamics and through correlations between synthesis parameters and structure of the obtained gels. The obtained results for the concentration of whey proteins solutions, by using temperature‐sensitive polymer gel, poly(N‐isopropylacrylamide), showed that the Gel Process can indeed be used as an advantageous alternative for such separation, either from an economic or from an environmental view point.
Anterograde–retrograde method for harvest of distally based sural fasciocutaneous flap: Report of results from 154 patients
Authors: Dong Zhong‐Gen , Wei Jian‐Wei , Ni Jiang‐Dong , Liu Li‐Hong , Luo Zhao‐Biao , Zheng Lei , He Ai‐Yong 
Published: October 2012

AbstractDistally based sural fasciocutaneous flap is traditionally raised by the retrograde method. This article introduces the anterograde–retrograde method for harvest of the flap and describes our experience on altering the flap plan. A total of 159 flaps in 154 patients were elevated by the anterograde–retrograde approach that harvest of the flap began with exploring the peroneal artery perforators nearby the pivot point before the upper and bilateral edges of the flap were incised. Partial necrosis occurred in 16 (10.1%) flaps, and marginal necrosis developed in 10 flaps. Nine flaps were redesigned with adjusted pivot point and skin island. The anterograde–retrograde approach for harvest of the flap can accurately locate the perforator, readily adjust both the pivot point and skin island if necessary, and thus improve reliability of the flap. This approach is particularly applicable for elevation of the flap without preoperative localization of the perforators by means of the Doppler. © 2012 Wiley Periodicals, Inc.
An improved two‐grid preconditioner for the solution of three‐dimensional Helmholtz problems in heterogeneous media
Authors: Calandra Henri , Gratton Serge , Pinel Xavier , Vasseur Xavier 
Published: October 2012

SUMMARYIn this paper, we address the solution of three‐dimensional heterogeneous Helmholtz problems discretized with second‐order finite difference methods with application to acoustic waveform inversion in geophysics. In this setting, the numerical simulation of wave propagation phenomena requires the approximate solution of possibly very large indefinite linear systems of equations. For that purpose, we propose and analyse an iterative two‐grid method acting on the Helmholtz operator where the coarse grid problem is solved inaccurately. A cycle of a multigrid method applied to a complex shifted Laplacian operator is used as a preconditioner for the approximate solution of this coarse problem. A single cycle of the new method is then used as a variable preconditioner of a flexible Krylov subspace method. We analyse the properties of the resulting preconditioned operator by Fourier analysis. Numerical results demonstrate the effectiveness of the algorithm on three‐dimensional applications. The proposed numerical method allows us to solve three‐dimensional wave propagation problems even at high frequencies on a reasonable number of cores of a distributed memory computer. Copyright © 2012 John Wiley & Sons, Ltd.