bluuebunny/crossref_metadata_2025 huggingface dataset:
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

Summary: 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

Summary: 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

Summary: 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

Summary: 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

Summary: 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

Summary: 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

Summary: 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

Summary: 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

Summary: 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

Distally 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

In 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.
What does the future hold for giving? An approach using the social representations of Generation Y
Authors: Urbain Caroline , Gonzalez Christine , Gall‐Ely Marine Le
Published: October 2012

Nowadays, not‐for‐profit organizations and charities face the ageing of donors and a growing debate over monetary donation collection methods. They need to find solutions to attract younger generations of donors. Could this be done using the same methods applied to older generations? This present research investigates social representations (SRs) of giving by younger generations to understand how not‐for‐profit organizations and charities should approach them. The study focuses on SRs of a French sample of 276 individuals from Generation Y born between 1979 and 1991. It uses the free association technique. The results show paradoxical representations of giving. Institutionalization of giving is salient as representation of it as a freely consenting act. The paradox relies also in the strong presence of a relationship with others that parallels the gift as an individualistic choice.

Generation Y individuals appear to be sociable, yet they evoke more sharing and solidarity than charity. Institutionalized forms of giving, particularly via charities and not‐for‐profit organizations, are rejected. These individuals seem to express their individuality through practices that resemble sharing rather than giving. From a managerial point of view, these results shed light on the factors liable to cause members of this generation to give, such as (i) the use of social networks, (ii) appealing to pleasure, festivities and efficiency rather than to guilt and duty, and (iii) encouragement to “work within the not‐for‐profit organization”.

Copyright © 2012 John Wiley & Sons, Ltd.
Hydrogen related phenomena at the ITO/a‐Si:H/Si heterojunction solar cell interfaces
Authors: Ulyashin Alexander , Sytchkova Anna
Published: October 2012

Properties of thin a‐Si:H and indium‐tin oxide (ITO) layers as well as properties of interfaces of Si based heterojunction (HJ) ITO/(p)a‐Si:H/n‐Si structures were analyzed by means of atomic force microscopy (AFM) and scanning spreading resistance microscopy. It is shown that the morphology of thin ITO layers grown on n‐type polished crystalline Si or on (p)a‐Si:H/n‐Si substrates depends on the deposition temperature and has peculiarities on nano‐scale. Formation of highly conductive nano‐dots on the surface and in the bulk of ITO layers is found. The observed nano‐spots and nano‐dots are attributed to the influence of hydrogen initiated reduction process, which occurs upon deposition of ITO films on an a‐Si:H layer during the fabrication process of a HJ solar cell. This fact is confirmed by investigation of morphological properties of ITO surfaces after treatment by hydrogen plasma. It is shown that formation of conductive nano‐particles on the ITO surface initiated by hydrogen does not change essentially transparency of an ITO layer. It is concluded that conductive nano‐dots at the ITO/a‐Si:H interface can be considered as local conductive channels, which provide a current flow through the ITO/(p)a‐Si:H interface without essential shadowing of the solar cell structure. This finding opens an interesting way for the optimization of properties of the ITO/Si‐based HJ solar cells.
Facilely constructing robust nanohybrids comprising high dispersion of platinum–ruthenium nanoparticles on carbon nanotubes and their enhanced electrocatalytic performance
Authors: Cui Ying , Wu Bohua , Mao Liqiu , Yin Dulin
Published: October 2012

A method for high dispersion of PtRu nanoparticles (NPs) on carbon nanotubes (CNTs) based on noncovalently functionalized CNTs with dodecylamine (DA) is reported. The process of functionalization of CNTs by DA is simple and can be carried out at room temperature without the use of expensive chemicals or corrosive acids, thus preserving the electronic conductivity and the corrosion resistance of CNTs. PtRu NPs on DA‐functionalized CNTs show much better distribution with no formation of aggregates, higher electrochemically active surface (EAS) area, and higher electrocatalytic activity and stability for the electrooxidation of methanol as compared to that on conventional acid‐oxidized CNTs.

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Single‐walled carbon nanotubes filled with nickel halogenides: Atomic structure and doping effect
Authors: Kharlamova M. V. , Yashina L. V. , Eliseev A. A. , Volykhov A. A. , Neudachina V. S. , Brzhezinskaya M. M. , Zyubina T. S. , Lukashin A. V. , Tretyakov Yu. D.
Published: October 2012

NiX2@SWCNT (X = Cl, Br) nanostructures were prepared by capillary filling of single‐walled carbon nanotube channels with nickel halogenide melts with slow cooling down to room temperature for better crystallization. The HRTEM data indicated formation of well‐ordered 1D NiBr2 crystals, with the experimental atomic structure representing a fragment of the bulk structure. The lattice constant coincides with the corresponding distance in bulk lattice. The 1D crystal structure was modeled using DFT within the PW‐GGA approach. According to the Raman, X‐ray photoelectron, X‐ray and optical absorption spectroscopic data and the DFT results obtained within the rigid band model, nickel halogenides display acceptor behavior with the corresponding charge transfer from the single‐walled carbon nanotube walls to the NiX2 nanocrystals.
Growth and characterization of thin Si–C films in RF plasma and optical emission spectroscopy
Authors: Kurcz Magdalena , Huczko Andrzej
Published: October 2012

Radio frequency (RF; 13.56 MHz), non‐equilibrium low‐pressure plasma is a robust environment well suited for the deposition of thin films. The parametric research has been carried out in a novel system on the formation of SiC‐related thin films resulting from the decomposition of tetramethylsilane TMS, Si(CH3)4. The films were deposited under various conditions to determine the effects of process parameters on both deposition and quality of the films. Carbonaceous thin films (methane CH4 was used as a precursor) were deposited too, to prove broad applicability of RF plasma. Optical emission spectroscopy helped to better understand the chemical transformation of starting reactants.
Easy synthesis of Pd fullerene polymer structures from the molten state of tris(dibenzylideneacetone)dipalladium(0)
Authors: Nitze Florian , Barzegar Hamid Reza , Wågberg Thomas
Published: October 2012

Pd fullerene composites were first synthesized and studied in the early 90s by for example Nagashima et al. In this study we present a novel and rapid approach to synthesize Pd fullerides based on direct reaction of C60 with Pd2dba3. We show that the Pd fullerene polymer phase forms at temperatures around the melting point of Pd2dba3 (150 °C) and that it proceeds upon further annealing while releasing dba. The synthesis reactions were studied in TGA/DSC. TEM revealed that the material easily collapses under the electron beam into nanoparticles. Under very low doses almost no particles can be found. Similarly, Raman spectroscopy confirmed the formation of Pd fulleride polymers but also supported the collapse of the Pd fulleride phase when irradiated by high laser power. CVD experiments have been conducted on directly coated Si substrates showing similar results to previous reports, namely that Pd2C60 is an efficient catalysts for the growth of helical carbon nanofibers. Our study gives both insights into the formation of nanoparticles as well as the synthesis of C60 polymers. The method is also compatible with direct coating processes making it useful for a broad spectrum of CVD and catalysis applications.
TiO2/WO3/Au/MWCNT composite materials for photocatalytic hydrogen production: Advantages and draw‐backs
Authors: Pap Zsolt , Karácsonyi Éva , Baia Lucian , Pop Lucian Cristian , Danciu Virginia , Hernádi Klára , Mogyorósi Károly , Dombi András
Published: October 2012

TiO2/WO3/Au/MWCNT composite materials were obtained using different commercial titanias (Aldrich Anatase, Aldrich Rutile, and Evonik Aeroxide P25) and Aldrich WO3. The gold nanoparticles were deposited on the semiconductor oxides' surface by chemical reduction using sodium borohydride, and the MWCNT's were combined with the composite (in different concentrations 0.1–10 wt%) by applying an ultrasonication method. The obtained nanocomposites were successfully characterized by means of X‐ray diffraction, transmission electron microscopy, etc. The aim of the present work was to find the optimal composition (i.e. carbon nanotube content) of the composite for photocatalytic hydrogen production using oxalic acid as a sacrificial agent.
Covalent functionalization of few‐wall carbon nanotubes by ferrocene derivatives for bioelectrochemical devices
Authors: Allali Naoual , Urbanova Veronika , Mamane Victor , Waldbock Jeremy , Etienne Mathieu , Mallet Martine , Devaux Xavier , Vigolo Brigitte , Fort Yves , Walcarius Alain , Noël Maxime , Soldatov Alexander V. , McRae Edward , Dossot Manuel
Published: October 2012

The present work reports the covalent functionalization of few‐wall CNTs (FWCNTs) by ferrocene derivatives to (i) improve their dispersion efficiency in water and (ii) graft electroactive chemical groups on their side‐walls in order to promote electron transfer to biomolecules. The functionalized CNTs (f‐CNTs) are used to modify a glassy carbon electrode and this modified electrode is used for oxidizing the cofactor NADH (dihydronicotinamide adenine dinucleotide).
Molecular beam epitaxy of graphene on mica
Authors: Lippert G. , Dabrowski J. , Yamamoto Y. , Herziger F. , Maultzsch J. , Baringhaus J. , Tegenkamp C. , Lemme M. C. , Mehr W. , Lupina G.
Published: October 2012

Realization of graphene devices is often hindered by the fact that the known layer growth methods do not meet the requirements of the device fabrication in silicon mainstream technology. For example, the relatively straightforward method of decomposition of hexagonal SiC is not CMOS‐compatible due to the high‐thermal budget it requires [Moon et al., IEEE Electron Device Lett. 31, 260 (2010)]. Techniques based on layer transfer are restricted because of the uncertainty of residual metal contaminants, particles, and structural defects. Of interest is thus a method that would allow one to grow a graphene film directly in the device area where graphene is needed. Production of large area graphene is not necessarily required in this case, but high quality of the film and metal‐free growth on an insulating substrate at temperatures below 1000 °C are important requirements. We demonstrate direct growth of defect‐free graphene on insulators at moderate temperatures by molecular beam epitaxy. The quality of the graphene was probed by high‐resolution Raman spectroscopy, indicating a negligible density of defects. The spectra are compared with those from graphene flakes mechanically exfoliated from native graphite onto mica. These results are combined with insights from density functional theory calculations. A model of graphene growth on mica and similar substrates is proposed.

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Improved performance of silicon‐nanoparticle film‐coated dye‐sensitized solar cells
Authors: Gupta Ravindra Kumar , Bedja Idriss M. , Aldwayyan Abdullah Saleh
Published: October 2012

Silicon (Si) nanoparticles with average size of 13 nm and orange–red luminescence under UV absorption were synthesized using electrochemical etching of silicon wafers. A film of Si nanoparticles with thickness of 0.75 µm to 2.6 µm was coated on the glass (TiO2 side) of a dye‐sensitized solar cell (DSSC). The cell exhibited nearly 9% enhancement in power conversion efficiency (η) at film thickness of ∼2.4 µm under solar irradiation of 100 mW/cm2 (AM 1.5) with improved fill factor and short‐circuit current density. This study revealed for the first time that the Si‐nanoparticle film converting UV into visible light and helping in homogeneous irradiation, can be utilized for improving the efficiency of the DSSCs. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Auger carrier leakage in III‐nitride quantum‐well light emitting diodes
Authors: Deppner Marcus , Römer Friedhard , Witzigmann Bernd
Published: October 2012

Auger induced leakage is shown to be a contributing factor for the internal quantum efficiency (IQE) droop in III‐nitride quantum‐well light emitting diodes (LEDs). The mechanism is based on leakage current from carrier spill‐out of the well originating from energy transfer during Auger recombination. Adding this leakage reduces the Auger coefficient by 50% when compared to a standard Auger model with cubic density dependence. As reference, experimental data of a green quantum‐well LED are taken. Direct leakage due to non‐ideal carrier capture and re‐emission out of the well affects the IQE at current densities much larger than the maximum IQE point. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Facile one‐step fabrication of highly transparent and flexible superhydrophobic substrate by room‐temperature ion irradiation method
Authors: Ghosh Pradip , Satou Shunsaku , Nakamori Hiroaki , Noda Takuto , Daisuke Ishii , Tanemura Masaki
Published: October 2012

Highly transparent (transparency 96.5%), flexible and antireflective superhydrophobic (water contact angle >150°) surfaces have been fabricated at room temperature by the ion irradiation method. This one‐step fabrication route was fairly easy to carry out without any heat or chemical treatment and can be completed within few seconds. This novel chemical free fabricating strategy could be extended to numerous polymeric substrates to achieve transparent and flexible superhydrophobic structures for their potential applications in diverse fields. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The Sustainable City: An Analytical–Deliberative Approach to Assess Policy in the Context of Sustainable Urban Development
Authors: Dassen Ton , Kunseler Eva , van Kessenich Lieke Michiels
Published: October 2012

The Sustainable City study of the Netherlands Environmental Assessment Agency (PBL) uses an analytical–deliberative approach to generate integrated options for strategic, long‐term urban development policies in the Netherlands. Scenarios for the sustainable city were designed using visions and roadmaps that were actively developed by actors involved in urban development and planning. The subsequent scenario analysis on potential, coherence and distributional effects across socio‐economic groups was combined with the narratives from the stakeholder dialogues to develop model‐based narratives. These model‐based narratives indicate the necessity of extensive national and international policy choices in the fields of energy, transport and spatial planning for the ecological sustainability of cities. The local level emerges as crucial when it comes to social sustainability. A transition that would benefit sustainability on all dimensions may be reached when citizens and civic and private organizations start to value (more) aspects of urban design and development that contribute to and create a sustainable quality of life. Thus far, little attention has been paid to policy‐relevant knowledge on the urgency and complexity of triggering any such transitions. Based on the lessons learnt from this study, it can be concluded that, in the follow‐up to this study, issues crucial to urban sustainable development have to be made more specific and concrete and more attention is needed for technological, institutional and societal feasibility. Interaction with policy makers and other stakeholders is again crucial. Copyright © 2012 John Wiley & Sons, Ltd and ERP Environment.
Dynamic prediction by landmarking in competing risks
Authors: Nicolaie M. A. , van Houwelingen J. C. , de Witte T. M. , Putter H.
Published: October 2012

We propose an extension of the landmark model for ordinary survival data as a new approach to the problem of dynamic prediction in competing risks with time‐dependent covariates. We fix a set of landmark time points tLM within the follow‐up interval. For each of these landmark time points tLM, we create a landmark data set by selecting individuals at risk at tLM; we fix the value of the time‐dependent covariate in each landmark data set at tLM. We assume Cox proportional hazard models for the cause‐specific hazards and consider smoothing the (possibly) time‐dependent effect of the covariate for the different landmark data sets. Fitting this model is possible within the standard statistical software. We illustrate the features of the landmark modelling on a real data set on bone marrow transplantation. Copyright © 2012 John Wiley & Sons, Ltd.
Emotional Exhaustion and Cognitive Performance in Apparently Healthy Teachers: A Longitudinal Multi‐source Study
Authors: Feuerhahn Nicolas , Stamov‐Roßnagel Christian , Wolfram Maren , Bellingrath Silja , Kudielka Brigitte M.
Published: October 2012

We investigate how emotional exhaustion (EE), the core component of burnout, relates to cognitive performance, job performance and health. Cognitive performance was assessed by self‐rated cognitive stress symptoms, self‐rated and peer‐rated cognitive impairments in everyday tasks and a neuropsychological test of learning and memory (LGT‐3); job performance and physical health were gauged by self‐reports. Cross‐sectional linear regression analyses in a sample of 100 teachers confirm that EE is negatively related to cognitive performance as assessed by self‐rating and peer‐rating as well as neuropsychological testing (all p < .05). Longitudinal linear regression analyses confirm similar trends (p < .10) for self‐rated and peer‐rated cognitive performance. Executive control deficits might explain impaired cognitive performance in EE. In longitudinal analyses, EE also significantly predicts physical health. Contrary to our expectations, EE does not affect job performance. When reversed causation is tested, none of the outcome variables at Time 1 predict EE at Time 2. This speaks against cognitive dysfunctioning serving as a vulnerability factor for exhaustion. In sum, results underpin the negative consequences of EE for cognitive performance and health, which are relevant for individuals and organizations alike. In this way, findings might contribute to the understanding of the burnout syndrome. Copyright © 2012 John Wiley & Sons, Ltd.
Unconscious Fearful Priming Followed by a Psychosocial Stress Test Results in Higher Cortisol Levels
Authors: Hänsel Alexander , von Känel Roland
Published: October 2012

Human perception of stress includes an automatic pathway that processes subliminal presented stimuli below the threshold of conscious awareness. Subliminal stimuli can therefore activate the physiologic stress system. Unconscious emotional signals were shown to significantly moderate reactions and responses to subsequent stimuli, an effect called ‘priming’.

We hypothesized that subliminal presentation of a fearful signal during the Stroop task compared with an emotionally neutral one will prime stress reactivity in a subsequently applied psychosocial stress task, thereby yielding a significant increase in salivary cortisol. Half of 36 participants were repeatedly presented either a fearful face or a neutral one. After this, all underwent a psychosocial stress task. The fearful group showed a significant increase in cortisol levels (p = 0.022). This change was not affected by sex, age and body mass index, and it also did not change when taking resting cortisol levels into account. Post‐hoc analyses showed that the increase in cortisol in the fearful group started immediately after the psychosocial stress test. Hence, subliminal exposure to a fearful signal in combination with the Stroop and followed by a psychosocial stress test leads to an increase in stress reactivity. Copyright © 2012 John Wiley & Sons, Ltd.
Fetal obstructive uropathy complicated by urinary ascites: outcome and prognostic value of fetal serum β‐2‐microglobulin
Authors: Spaggiari E. , Dreux S. , Czerkiewicz I. , Favre R. , Schmitz T. , Guimiot F. , Laurichesse Delmas H. , Verspyck E. , Oury J.‐F. , Ville Y. , Muller F.
Published: October 2012

Objectives

To determine whether the prognostic value of fetal serum β‐2‐microglobulin is altered and whether the occurrence of fetal urinary ascites prevents kidney damage in cases of fetal obstructive uropathy with urinary ascites.

Methods

This was a retrospective study of cases of fetal bilateral obstructive uropathy that occurred between 2006 and 2010, for which both fetal serum and ascites samples were sent to our laboratory for analysis. β‐2‐microglobulin was assayed in both fetal serum and the corresponding ascites. Renal outcome was analyzed. Histological features of the kidney in cases of termination of pregnancy and renal function of liveborn infants were recorded.

Results

Fourteen cases with analysis of fetal serum and fetal ascites in a context of urinary obstruction were included. Renal outcome was unfavorable in eight cases (57%) and favorable in six (43%). When fetal serum β‐2‐microglobulin was < 5 mg/L, renal outcome was favorable in all cases (4/4). When fetal serum β‐2‐microglobulin was ≥ 5 mg/L, 8/10 cases (80%) had an unfavorable renal outcome (sensitivity, 100%; specificity, 66%).

Conclusion

Fetal serum β‐2‐microglobulin reliably predicts postnatal renal outcome in obstructive uropathy complicated by urinary ascites. Moreover, urine extravasation does not seem to protect fetal renal function.
The behavioural semantics of Event-B refinement
Authors: Schneider Steve , Treharne Helen , Wehrheim Heike
Published: October 2012

Event-B provides a flexible framework for stepwise system development via refinement. The framework supports steps for (a) refining events (one-by-one), (b) splitting events (one-by-many), and (c) introducing new events. In each of the steps events can be indicated as
convergent
(to be made internal) or
anticipated
(treatment deferred to a later refinement step). All such steps are accompanied with precise proof obligations. However, no behavioural semantics has been provided to validate the proof obligations, and no formal justification has previously been given for the application of these rules in a refinement chain. Behavioural semantics expresses a clear relationship between the first and last machines in a refinement chain. The framework we present provides a coherent justification for Abrial’s approach to refinement in Event-B, and its generalisation to interface extension: adding events to the interface. In this paper, we give a behavioural semantics for Event-B refinement, with a treatment for the first time of splitting events and of anticipated events, adding to the well-understood treatment of convergent events. To this end, we define a CSP semantics for Event-B and show how the different forms of Event-B refinement can be captured as CSP refinement. It turns out that the appropriate CSP refinement relationship is influenced by the particular Event-B
development strategy
taken. We present two such strategies, one allowing, the other disallowing interface extensions.
Introducing extra operations in refinement
Authors: Boiten Eerke A.
Published: October 2012

This paper reconsiders refinements which introduce actions on the concrete level which were not present at the abstract level. It considers a range of different basic refinement relations, covering the standard ones for formalisms like Event-B, Z, action systems, and CSP. It also describes a number of ways in which new operations may be introduced: extended interfaces, internal actions, stuttering steps, and action refinement. The main contribution of this paper is in exploring the interaction between those two dimensions. In particular, it shows how the “refining skip” method is incompatible with failures-based refinement relations, and consequently some decisions in designing Event-B refinement are more entangled than previously highlighted.
Utilization of agricultural biomass in the production of the biopolymer schizophyllan
Authors: Sutivisedsak Nongnuch , Leathers Timothy D , Nunnally Melinda S , Price Neil P J , Biresaw Girma
Published: October 2012

Schizophyllan is a homoglucan produced by the fungus Schizophyllum commune, with a β-1,3-linked backbone and β-1,6-linked side chains of single glucose units at every other residue. Schizophyllan is commercially produced for pharmaceutical and cosmetics uses. However, the unique physical properties of schizophyllan suggest that it may have biomaterials applications. Schizophyllan is conventionally produced by submerged culture fermentation using glucose as a carbon source. This study demonstrates for the first time the efficient utilization of agricultural biomass substrates, particularly distiller’s dried grains with solubles, for schizophyllan production. Sugar composition analysis, NMR, and permethylation linkage analysis confirmed that the recovered product was schizophyllan. Schizophyllan produced from agricultural residues was of a high molecular weight and exhibited solution viscosity properties similar to those of commercially produced material. Utilization of biomass substrates could reduce the cost of schizophyllan production and provide a new value-added bioproduct for integrated biorefineries of the future.
An examination of the mechanisms underlying the effects of physical activity on brain and cognition
Authors: Marmeleira José
Published: October 2012

Physical activity positively influences brain health and cognitive functioning in older adults. Several physiological and psychological mechanisms have been identified to underlie such a relationship. Cardiovascular fitness is accompanied with changes in mechanisms such as cerebral blood flow, neurotrophic factors, neurotransmitter systems and neural architecture that have themselves been associated with cognitive performance. Factors associated with exercise such as arousal, mood and self-perception of competence seem also to influence cognitive performance. Other explanation for the benefits of exercise in cognition, results from the fact that the performance of motor skills involve an important cognitive component (e.g., executive functions and information processing speed). Evidence of brain plasticity and behavior has been provided from studies where animals are exposed to enriched or complex environments. Exposure to such paradigms in which physical activity plays an important role has been found to influence various aspects of brain function and structure. Studies using neuroimaging techniques have established a link between the acquisition of different motor skills and the occurrence of neuroplasticity in human adults. This literature review indicates that the type of exercise and its specific perceptual and cognitive characteristics may influence cognitive performance. However, most of the research has been focused on self-paced movements or automatized skills and few intervention studies have examined the results of merging exercise and cognitive training in a single program. An important scientific challenge for the coming years is to design exercise programs capable of mobilizing several type of mechanisms underlying the effects of physical activity on brain and cognition.
Oxidative Stabilities of Enzymatically Interesterified Fats Containing Conjugated Linoleic Acid
Authors: Adhikari Prakash , Hu Peng , Yafei Zhang
Published: October 2012

Interesterified fat was produced from soybean oil (SBO) and palm stearin (PS) using two different weight ratios of substrates. Conjugated linoleic acid (CLA; 10 wt% on the weight of SBO and PS) was used as a functional fatty acid. Interesterification and acidolysis was simultaneously carried out to exchange fatty acids and incorporate CLA in the triacylglycerol (TAG) backbone, respectively, using immobilized lipase. Comparative study was carried out between interesterified fats and blends (before interesterification) for the quantification of physical properties (i.e., solid fat content, melting and crystallization behavior) and oxidative stability. In the interesterified fat 5.2–6.1 % CLA was incorporated in the TAG backbone. Blends showed higher solid fat content (SFC) and melting point than interesterified fat at each measured temperature. The Rancimat test was performed for the oxidative stability where the interesterified fat showed significantly lower induction time than physical blends. After the addition of antioxidants such as butylated hydroxytoluene (BHT), rosemary extract, tertiary butylhydroquinone (TBHQ), propyl gallate (PG), etc. into the interesterified fat, the induction time was significantly increased. On the other hand, different deacidification methods (alkaline, batch deodorized and short path distillation) were performed after interesterification to remove the free fatty acids. After deacidification, oxidative stability of alkaline deacidified sample showed significantly (P ≤ 0.05) longer induction time compared to short path distillation (SPD) and physically deacidified samples. In this study, interesterified functional fat that may have a potential functionality for the margarines and shortenings were produced and their oxidative stability was observed.
Lipase‐Catalyzed Acidolysis of Olive Oil with Echium Oil Stearidonic Acid: Optimization by Response Surface Methodology
Authors: Bilgiç Sena , Yeşilçubuk Neşe Şahin
Published: October 2012

In this study, our aim was to enrich olive oil with stearidonic acid (SDA) together with polyunsaturated fatty acids (PUFA) by lipase‐catalyzed acidolysis using olive oil (OO) and free fatty acids of Echium oil, in the presence of Lipozyme® TL IM. The reaction conditions were optimized by using response surface methodology. A three‐factor, five level central composite circumscribed designs was used to generate the design points. The factors chosen were: substrate molar ratio (Sr, 4–6 mol/mol), reaction temperature (T, 55–65 °C), and reaction time (t, 6–9 h). Targeted incorporation (5 %) of SDA into OO was achieved at substrate molar ratio of 6 mol/mol, 55 °C, and 8.4 h. Model verification performed under these conditions for mg‐ and g‐scale production yielded SDA contents of 4.9 and 4.8 %, respectively. Moreover, it was observed that the structured lipid (SL) obtained under optimum conditions contained approximately 42 % oleic acid and 43 % PUFA including linoleic acid, α‐linolenic acid, and γ‐linolenic acid. Omega‐6/omega‐3 fatty acid ratio of SLs was 0.7. Analysis of oxidative properties resulted in lower oxidative stability of SL than unmodified OO. This type of SL containing SDA and other PUFA is believed to be beneficial for human health.
Water‐Blown Rigid Biofoams from Soy‐Based Biopolyurethane and Microcrystalline Cellulose
Authors: Luo Xiaogang , Mohanty Amar , Misra Manju
Published: October 2012

A novel soy‐based polyurethane biofoam (BioPU) from two polyols (soybean oil‐derived polyols SOPEP and petrochemical polyol Jeffol A‐630 = 1:1 in weight) and poly (diphenylmethane diisocyanate) (pMDI) has been prepared by using a free‐rise method with water as a blowing agent, and microcrystalline cellulose (MCC) as a reinforcement. The photographs of the samples show that the biofoams have similar appearances, and the cell morphology of the resulting biofoams was examined by scanning electron microscope. Density of the composites decreased as a result of increase in MCC content. FTIR study exhibited characteristic peaks for MCC and BioPU. Mechanical properties such as compressive strength, compressive modulus, flexural strength and flexural modulus of the samples were substantially improved with the increase in MCC content. Similarly, improvements in glass transition temperature (Tg) and storage modulus around and after Tg of the neat biofoam were also observed with the composites. Dynamic mechanical analysis results showed an improvement in mechanical properties as well as better thermal stability of the composites over the neat biofoam. Thermogravimetric analysis showed improved thermal stability of the biofoams reinforced with MCC. This research has provided a simple method for preparing the biofoam, while exploring the potential of substituting up to 50 % of the petroleum‐based polyol in biofoam applications.
Iron Oxide Catalysts Supported on Porous Silica for the Production of Biodiesel from Crude Jatropha Oil
Authors: Suzuta Tetsuya , Toba Makoto , Abe Yohko , Yoshimura Yuji
Published: October 2012

A heterogeneous catalyst, FeOx/SiO2, prepared by the pore‐filling method, was found to be active in the transesterification of crude Jatropha oil with methanol. When the transesterification reaction was carried out with a reaction temperature of 220 °C, a catalyst amount of 15 wt%, a methanol/oil molar ratio of 218:1, and a reaction time of 3 h, the yield of fatty acid methyl esters (FAME) in the product exceeded 99.0 %, and met with EN standards for allowable contents of glycerine and mono‐, di‐, and tri‐glycerides. The correlation between the FAME production activity and measured acidity of the FeOx/SiO2 catalysts showed that the transesterification reaction was promoted via the acidic function of these catalysts, which are less inhibited by coexisting free fatty acids in the feedstock triglycerides.
Physico‐chemical Properties of Marine Phospholipid Emulsions
Authors: Lu F. S. H. , Nielsen N. S. , Baron C. P. , Jensen L. H. S. , Jacobsen C.
Published: October 2012

Many studies have shown that marine phospholipids (PL) have better bioavailability, better resistance towards oxidation and contain higher polyunsaturated fatty acids such as eicosapentaenoic (EPA) and docosahexaenoic acids (DHA) than triglycerides (TAG) present in fish oil. The objective of this study was to investigate the emulsifying properties of various commercial marine PL and the feasibility of using them to prepare stable emulsions prepared with or without addition of fish oil. In addition, this study also investigated the relationship between chemical composition of marine PL and the stability of their emulsions. Physical stability was investigated through particle size distribution (PSD), zeta potential, microscopy inspection and emulsion separation (ES); while the oxidative and hydrolytic stability of emulsions were investigated through peroxide value (PV) and free fatty acids value (FFA) after 32 days storage at room temperature and at 2 °C. In conclusion, marine PL showed good emulsifying properties and it was possible to prepare marine PL emulsions with and without addition of fish oil. Emulsion with both good oxidative stability and physical stability could be prepared by using marine PL of high purity, less TAG, more PL, cholesterol and higher antioxidant content.
MicroRNA 497 modulates interleukin 1 signalling via the MAPK/ERK pathway
Authors: Zheng Dongling , Radziszewska Anna , Woo Patricia
Published: October 2012

The MAPK/ERK signalling pathway has been described to mediate IL‐1 induction of target genes and is known to be regulated by microRNAs (miRNA). We describe a novel miRNA regulating the expression of the MEK1 gene and how it impacts IL‐1 induced IL‐6 transcription. miR‐497 was predicted to target MEK1 3′UTR using bioinformatic tools. Transfection of miR‐497 into HeLa cells inhibited MEK1 protein expression by 50%. In transient transfection experiments, the luciferase activity of a MEK1 3′UTR luciferase reporter construct was reduced in the presence of miR‐497, and mutation of the predicted miR‐497 binding site restored activity. miR‐497 also decreased protein levels of RAF1 and ERK1 but not ERK2. Addition of miR‐497 was further shown to inhibit IL‐1 induced IL‐6 gene transcription.