bluuebunny/crossref_metadata_2025 huggingface dataset:
Innovative Cross‐Linked Polyurethane Networks Based on Cyclodextrins and Polyethylene Glycols: Inclusion Capacity and Potential Use as Controlled Release Carrier for Nifedipine
Authors: de Araújo Márcia Valéria Gaspar , Vieira João Victor Francisco , da Silva Thiago Alessandre , Kubota Tatiana , Barboza Fernanda Malaquias , Farago Paulo Vitor , Zawadzki Sônia Faria
Published: October 2012

Summary: Polymers derived from cyclodextrins show several biomedical applications. In this paper, six cross‐linked polyurethane networks based on β‐cyclodextrin (βCD) or hydroxypropyl‐β‐cyclodextrin (HPβCD) and polyethylene glycols (PEG 400, PEG 1500 or PEG 4000) were synthesized by the usual two‐step polymerization method. The polymers were characterized by Fourier‐transformed infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA) and X‐ray diffraction (XRD). The inclusion capacity was evaluated by the discoloration method of a phenolphthalein solution. In order to explore their potential use as controlled drug delivery systems, dissolution profiles and release behavior of inclusion complexes between PUR/TDI/βCD/PEG4000 or PUR/TDI/HPβCD/PEG1500 and nifedipine (NIF) were investigated. FTIR assignments confirmed the formation of urethane linkages. XRD patterns revealed that the crystallinity decreased mainly due to the crosslinking process. TGA showed three stages of mass loss attributed to water loss, cleavage of urethane bonds and volatilization of decomposition products. The inclusion capacity of cyclodextrins cross‐linked with polyurethane was suitably maintained. Dissolution profiles demonstrated that the inclusion complexes PUR/TDI/βCD/PEG4000‐NIF and PUR/TDI/HPβCD/PEG1500‐NIF are feasible systems for controlling drug release, showing a biexponential release behavior.
Characterization of Polyurethanes from Vegetable Oils by TG/DTG, DMA and FT‐IR
Authors: Lopes Roseany V. V. , Osorio Luis F. B. , Santos Maria L. , Sales Maria J. A.
Published: October 2012

Summary: Given the demand for renewable resources by industries and the promising potential of vegetable oils for this purpose, the current study aims to evaluate the properties of polyurethanes (PUs) obtained from linseed (Linum usitatissimun L.) oil (PULO) and passion fruit (Passiflora edulis Sims f. flavicarpa Degener) oil (PUPFO), by thermogravimetry (TG), derivative thermogravimetry (DTG), dynamic mechanical analysis (DMA) and Fourier transform infrared (FT‐IR). The results showed that PULO is more thermally stable than PUPFO, suggesting that the first presents more urethane linkages. The DMA analysis showed that both prepared PUs have uneven porosity, causing the loss of the elastic plateau. It was found as well that PUPFO exhibits a higher value of glass transition temperature (Tg), signifying that it seems to be more crosslinked than PULO. The analysis by FT‐IR showed that the curing reaction of PUs was successful.
Influence of Carbon Black, Calcium Carbonate and Dioctyl Phthalate Compositions on the NBR Vulcanized Rubber Properties Through Experiments Design
Authors: Correia Sivaldo L. , Palaoro Denilso , Mautone André , Segadães Ana M.
Published: October 2012

Summary: In industrial practice involving mixtures of raw materials, it is desirable to be able to predict how a change in their proportions will affect the product's properties. In this work the effect of three major vulcanized rubber raw materials was investigated. All other raw materials, as well as processing conditions, were kept constant. Ten formulations were vulcanized by compression moulding (175 °C, ∼17 MPa, during 5 minutes) and characterized. The statistically valid property equations calculated from the characterization results show that a range of compositions exists within which the final product has the desired properties and can still be comfortably manufactured.
Synthesis and Characterization of the Monomer 2,2′ diallylbisphenol‐A (ABFA) for obtaining Proton Exchange Membranes based on Crosslinked Sulphonated Poly(Arylene ether sulphone)s
Authors: Souza Júlio C. , Souza Carlos H. F. B. , Silva Claúdio Homero F. , Silva Maria Elisa S. R. , Sousa Ricardo G. , Freitas Roberto F. S.
Published: October 2012

Summary: In the present work, a methodology of synthesis and characterization of the monomer 2,2′ diallylbisphenol‐A (ABFA) was developed, aiming at getting a precursor, with adequate purity, for obtaining cross‐linked membranes based on sulphonated poly(arylene ether sulphone)s. The monomer synthesis involved the synthesis of 2,2′ bis(4‐allyloxiphenyl)propane (Bisphenol‐A, diallyl ether ‐ BFAAE), from Bisphenol‐A (BFA), followed by Claisen rearrangement of BFAAE, for the production of the target compound 2,2′ diallylbisphenol‐A (ABFA). All the compounds, reagent BFA and obtained products, intermediate product BFAAE and final product ABFA, were characterized by FTIR (Fourier Transform infrared spectroscopy), TGA (Thermo‐gravimetric analysis) and HPLC (High‐performance liquid chromatography). The compound BFAAE was obtained with a yield of 94.5% and a purity of 97.3%, the latter characterized by TGA and by HPLC. The structure of the product was confirmed by FTIR. The thermal Claisen rearrangement process was conducted by using Differential Scanning Calorimetry (DSC) technique, from a factorial experiment planning, with two factors and three levels, with temperature and time being the variables. The above cited techniques were used for monitoring the Claisen rearrangement and for the characterization of the final product. The best results yield ABFA purity between 85 and 90%, approximately, for 220 °C/60min, 230 °C/30min and 210 °C/90min conditions. The obtained results suggest that, in the studied range, polymerization and degradation of the monomer ABFA occur, simultaneously to its formation.
The Effect of the Addition of Mg‐Al LDH Intercalated with Dodecyl Sulfate on the Fire Retardancy Properties of Epoxy
Authors: Becker Cristiane M. , Dick Teo A. , Ramos Jonathan T. , Wypych Fernando , Amico Sandro C.
Published: October 2012

Summary: Layered double hydroxides (LDH) are chemical compounds that can be added to polymeric resins to confer fire retardant characteristics. The focus of this work is to study the incorporation of LDH intercalated with dodecylsulfate anions into epoxy resins. The mechanical properties were investigated using tensile, flexural and impact mechanical tests. The flame‐retardant properties were assessed using horizontal (UL 94 HB) and vertical burning (UL 94 V) tests. The highest tensile strength was obtained for the composite with 3 wt% of LDH, whereas the highest flexural strength was found by incorporating 1 wt% of LDH. All samples containing LDH showed self‐extinguishing behavior in the vertical test and lower burning rate than pristine epoxy.
PANI Conductivity: A Dependence of the Chemical Synthesis Temperature
Authors: Paschoalin Rafaella T. , Steffens Clarice , Manzoli Alexandra , Paris Elaine C. , Herrmann Paulo S. P.
Published: October 2012

Summary: This work evaluated the influence of the synthesis temperature on the polyaniline (PANI) properties obtained by in‐situ polymerization onto a poly (terephthalate) (PET) substrate. The residual mass of these syntheses was dried under vacuum, obtaining PANI powders for each temperature investigated. PANI/PET thin films and PANI powders were characterized by atomic force microscopy (AFM), field emission scanning electron microscopy (FEG‐SEM), X‐ray diffraction (XRD), ultraviolet‐visible spectroscopy (UV‐Vis) and four‐point probe techniques. The UV‐Vis results showed that the synthesized PANI presents the emeraldine oxidation state. By means of XRD technique, it was possible to verify that the PANI powders present crystalline form. The AFM and FEG‐SEM techniques showed that the decrease in PANI/PET and PANI powders electrical conductivity with increasing of the synthesis temperature is related to the polymeric aggregates morphology.
Preparation and Cytotoxicity of Poly(Methyl Methacrylate) Nanoparticles for Drug Encapsulation
Authors: Mendes Anderson N. , Hubber Isabela , Siqueira Mônica , Barbosa Gleyce Moreno , de Lima Moreira Davyson , Holandino Carla , Pinto José Carlos , Nele Marcio
Published: October 2012

Summary: This work aimed to produce poly(methyl methacrylate) nanoparticles for use in drug encapsulation. The polymer nanoparticles were produced using miniemulsion polymerization technique. Monomer miniemulsion showed moderate stability and polymer average particle size was about 90 nm. PMMA nanoparticles were tested for toxicity in human leukemic cell strain K562 and they did not show any adverse effect on cell viability. Therefore, poly(methyl methacrylate) nanoparticles are suitable to encapsulate antitumor agents.
Production of Poly(acrylic acid) Particles Dispersed in Organic Media
Authors: Pinto Martina C. C. , Gomes Frederico W. , Melo Caio K. , Melo Príamo A. , Castro Márcio , Pinto José Carlos
Published: October 2012

Summary: A process for preparation of poly(acrylic acid) particles dispersed in oil is presented. The process comprises two steps: the first step involves the preparation of a poly(acrylic acid) solution, while the second step consists in the preparation of the polymer particles by dispersing the polymer solution in an organic phase. During the second step, modification of the polymer chain structure can be performed through chemical reactions. One of the advantages of the proposed process is the possibility to produce particles loaded with drugs or other chemical compounds. Besides that, if the continuous phase is vegetable oil, purification of the reaction medium may not be necessary.
An exploratory study of stalled relationships among art museum members
Authors: Reavey Brooke , Howley Michael J. , Korschun Daniel
Published: October 2012

Museums must maintain a steady membership base to achieve their organizational objectives. Although many studies look at why relationships succeed, we examine members who fail to transition from an introductory relationship to a mature relationship with an art museum. In two studies examining non‐renewing members of a large metropolitan art museum, we find evidence for a phenomenon we call “stalled” relationships, whereby members discontinue their formal museum membership yet maintain a positive psychological affiliation with the museum. Our first study finds that members in stalled relationships often do not view themselves as defectors and do not blame the museum for their non‐renewal; they frequently cite personal reasons rather than service failures for discontinuing their membership. Our second study examines this phenomenon in greater detail, exploring the antecedents for stalling and finds that motivations for initiating their membership may help predict when a relationship is likely to stall.

Copyright © 2012 John Wiley & Sons, Ltd.
Co‐creating nonprofit brand equity
Authors: Juntunen Mari , Juntunen Jouni , Autere Vesa
Published: October 2012

The concept of brand equity (BE) has been the subject of much recent discussion in the field of nonprofit branding and also has been the concept of brand co‐creation in the field of branding. This study combines these aspects and examines the BE co‐creation of a nonprofit entity, the Finnish Defence Forces military driving school. Empirical data were collected from industrial logistics service providers and military recruits. A theoretical BE model was further developed using structural equation modeling in an exploratory manner to reveal whether the BE model of the military driving school is similar from both viewpoints. Similar workable models were found, indicating strong BE co‐creation and thereby contributing to the field. To support the future co‐creation of BE of the military driving school, it is important to ensure that the recruits take positive experiences from the school and industrial logistics service providers carefully consider how they relay their experiences about the school to other truck drivers. The attitudes of recruits towards the military driving school are likely eventually to conform to those of civilian truck drivers. Finding workable models required omitting some BE dimensions and measures of earlier models. Moreover, using data from one country alone may be a limitation of the study. Therefore, nonprofit BE measures should be further developed and tested with data from further afield.

Copyright © 2012 John Wiley & Sons, Ltd.
Characterizing antiprion compounds based on their binding properties to prion proteins: Implications as medical chaperones
Authors: Kamatari Yuji O. , Hayano Yosuke , Yamaguchi Kei‐ichi , Hosokawa‐Muto Junji , Kuwata Kazuo
Published: October 2012

A variety of antiprion compounds have been reported that are effective in ex vivo and in vivo treatment experiments. However, the molecular mechanisms for most of these compounds remain unknown. Here we classified antiprion mechanisms into four categories: I, specific conformational stabilization; II, nonspecific stabilization; III, aggregation; and IV, interaction with molecules other than PrPC. To characterize antiprion compounds based on this classification, we determined their binding affinities to PrPC using surface plasmon resonance and their binding sites on PrPC using NMR spectroscopy. GN8 and GJP49 bound specifically to the hot spot in PrPC, and acted as “medical chaperones” to stabilize the native conformation. Thus, mechanisms I was predominant. In contrast, quinacrine and epigallocathechin bound to PrPC rather nonspecifically; these may stabilize the PrPC conformation nonspecifically including the interference with the intermolecular interaction following mechanism II. Congo red and pentosan polysulfate bound to PrPC and caused aggregation and precipitation of PrPC, thus reducing the effective concentration of prion protein. Thus, mechanism III was appropriate. Finally, CP‐60, an edarabone derivative, did not bind to PrPC. Thus these were classified into mechanism IV. However, their antiprion activities were not confirmed in the GT + FK system, whose details remain to be elucidated. This proposed antiprion mechanisms of diverse antiprion compounds could help to elucidate their antiprion activities and facilitate effective antiprion drug discovery.
Defect generation, advanced crystallization, and characterization methods for high‐quality solar‐cell silicon
Authors: Di Sabatino Marisa , Stokkan Gaute
Published: October 2012

Silicon is the dominant material for production of solar cells. Research work constantly aims at improving the quality of the silicon materials to achieve higher solar‐cell conversion efficiencies. It has been demonstrated that defects and impurities, often rising during the silicon ingot production and due to the presence of impurity sources throughout the silicon solar‐cell value chain (e.g. silicon feedstock, crucible and coating, furnace atmosphere, etc.), have a detrimental effect on device performances. Crystallization is the first step in the solar‐cell value chain. During crystallization, crystal defects, such as grain boundaries and dislocations, develop, and impurities, such as dopants and metals, distribute. By controlling the process, we can also control the defect formation and impurity segregation. In this study, we review some of the work carried out at NTNU to understand the role of defects and impurities on materials properties. Specifically, we report on some of the work done on defects, crystallization, and characterization.
Structure and stability of coiled carbon nanotubes
Authors: Milošević Ivanka , Popović Zoran P. , Damnjanović Milan
Published: October 2012

Helically coiled carbon nanotubes are modeled using topological coordinate method which is based on the toroidal triply connected graphs, containing pentagons, hexagons, and heptagons. Their regular incorporation into the hexagonal carbon net induces transition from the straight to the helical geometry. Relaxation of the structural model is performed in two steps: Firstly, molecular dynamics based on the Brenner potential is applied and then the coil parameters are, once again, optimized within symmetry preserving density functional tight binding (DFTB) method. Model of smooth regularly helically coiled single‐walled nanotube structure is obtained. Correlations between the helical angle, tubular and helical diameter are found. Cohesive energy of the coiled structure is calculated by DFTB method within symmetry based POLSym code. Its dependence on the diameter of the coil is shown. The calculated energies range from 7.5 to 8.0 eV/atom.
Controlling edge states in the Kane–Mele model via edge chirality
Authors: Autès Gabriel , Yazyev Oleg V.
Published: October 2012

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We investigate the dependence of band dispersion of the quantum spin Hall effect (QSHE) edge states in the Kane–Mele model on crystallographic orientation of the edges. Band structures of the one‐dimensional honeycomb lattice ribbons show the presence of the QSHE edge states at all orientations of the edges given sufficiently strong spin–orbit interactions. We find that the Fermi velocities of the QSHE edge‐state bands increase monotonically when the edge orientation changes from zigzag (chirality angle $ \theta = 0^\circ $) to armchair ($ \theta = 30^\circ $). We propose a simple analytical model to explain the numerical results. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Topological surface states of Bi2Se3 coexisting with Se vacancies
Authors: Yan Binghai , Zhang Delin , Felser Claudia
Published: October 2012

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Although topological surface states are known to be robust against nonmagnetic surface perturbations, their band dispersions and spatial distributions are still sensitive to surface defects. Taking Bi2Se3 as an example, we demonstrate that Se vacancies modify the surface band structures considerably. When large numbers of Se vacancies exist on the surface, topological surface states may sink down from the first to the second quintuple layer and get separated from the vacancies. We simulated scanning tunnelling microscopy images to distinguish surfaces with Se and Bi terminations.

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(© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Robot assisted surgery in gynaecologic oncology – starting a program and initial learning curve from a UK tertiary referral centre: the Guildford perspective
Authors: Madhuri Thumuluru Kavitha , Hamzawala Imran , Tailor Anil , Butler‐Manuel Simon
Published: October 2012

Background

The paper discusses the setup and evaluation of early data following the establishment of a robotic surgery programme in a UK gynaecological oncology cancer centre.

Methods

Prospective data were collected between December 2009 and December 2011 for all women undergoing robotic assisted procedures within the gynaecological oncology department. Patient demographics, intra, peri and post‐operative data were collected at a single institution, which is a tertiary referral centre for gynaecological oncology and minimal access surgery.

Results

In total, 104 robotically assisted cases were performed within the gynaecological oncology team. The procedures undertaken included simple and radical hysterectomy, radical trachelectomy, BSO following previous hysterectomy, pelvic and para‐aortic node dissection and omentectomy. The mean blood loss was 155.24 mL and the mean hospital stay was 3 days with more than half the women being discharged on day 1 post surgery.

Conclusions

These data suggest that robotic assisted surgery is well suited to treating women with principally endometrial and cervical cancers and selected cases of ovarian cancer, enabling surgical staging to be completed with many more patients benefitting from a minimal access surgery approach. Thorough preparation, appropriate case selection and preceptorship in robotic surgery is essential to minimize the associated risks associated with adopting new surgical techniques. Copyright © 2012 John Wiley & Sons, Ltd.
Corporate Social Responsibility of the Financial Sector – Strengths, Weaknesses and the Impact on Sustainable Development
Authors: Weber Olaf , Diaz Michael , Schwegler Regina
Published: October 2012

This study analyses the performance of the financial sector with respect to corporate social responsibility and sustainability. Because this sector has a strong influence economically and on sustainable development, both risk management issues and stakeholder pressure drive the financial sector into a more sustainable direction. In contrast to polluting sectors, the financial sector does not affect the environment and society by direct emissions or the use of resources like other industries. To compare the financial sector with other sectors regarding their sustainability performance, we analyzed the performance in the fields of sustainability reporting, business ethics and product responsibility, labor issues, environmental performance, community issues, and corporate governance. The study is based on more than 1800 firms including 400 organizations from the financial sector. We link CSR to sustainability and define it as corporate self‐regulation in order to manage sustainability risks and opportunities. The results suggest that financial sector performance is relatively low regarding corporate social responsibility (CSR) in general. Weaknesses of the financial sector with regard to CSR are reporting, business ethics and product responsibility, and labor issues. Strengths of the financial sector regarding CSR can be located with respect to community relations. Further research is needed with respect to the factors influencing CSR performance. It is still not clear what influences regulations, stakeholder pressure or potential financial benefits have on sustainability performance in the financial sector. Copyright © 2012 John Wiley & Sons, Ltd and ERP Environment.
Doubly robust estimators of causal exposure effects with missing data in the outcome, exposure or a confounder
Authors: Williamson E.J. , Forbes A. , Wolfe R.
Published: October 2012

We consider the estimation of the causal effect of a binary exposure on a continuous outcome. Confounding and missing data are both likely to occur in practice when observational data are used to estimate this causal effect. In dealing with each of these problems, model misspecification is likely to introduce bias. We present augmented inverse probability weighted (AIPW) estimators that account for both confounding and missing data, with the latter occurring in a single variable only. These estimators have an element of robustness to misspecification of the models used. Our estimators require two models to be specified to deal with confounding and two to deal with missing data. Only one of each of these models needs to be correctly specified. When either the outcome or the exposure of interest is missing, we derive explicit expressions for the AIPW estimator. When a confounder is missing, explicit derivation is complex, so we use a simple algorithm, which can be applied using standard statistical software, to obtain an approximation to the AIPW estimator. Copyright © 2012 John Wiley & Sons, Ltd.
Pedagogical content knowledge as reflected in teacher–student interactions: Analysis of two video cases
Authors: Alonzo Alicia C. , Kobarg Mareike , Seidel Tina
Published: October 2012

Despite the theorized centrality of pedagogical content knowledge (PCK) for teaching, we have little evidence of the relationship between PCK and students' learning and know relatively little about how to help teachers to develop PCK. This study is a preliminary attempt to address these gaps in our knowledge of PCK through exploration of two German physics teachers' classroom instruction in consecutive lessons on optics. We show how video analysis can be used to gather evidence for one aspect of teachers' PCK: their use of content knowledge in interactions with students. We identify three potentially important characteristics of this aspect of PCK: flexibility, richness, and learner‐centeredness. By contrasting teachers with high and low gains in student knowledge and interest, we explore potential mechanisms by which this aspect of PCK might affect student outcomes. Because German teacher preparation programs emphasize content more than pedagogical knowledge, these cases contribute to our understanding of the support that teachers with strong content knowledge may need in translating this knowledge into a form useful for teaching.Fachdidaktisches Wissen ist aus theoretischer Sicht besonders zentral für das Unterrichten. Aus empirischer Sicht gibt es bislang allerdings noch wenig Evidenz für den Einsatz fachdidaktischen Wissens während des Unterrichtens und seine Bedeutung für das Lernen von Schülerinnen und Schülern. Außerdem wissen wir wenig darüber, wie Lehrpersonen über die Zeit fachdidaktisches Wissen entwickeln. Diese Studie ist ein Versuch, diese Wissenslücken zum fachdidaktischen Wissen von Lehrpersonen zu bearbeiten. Dabei wird exemplarisch der Unterricht von zwei deutschen Physiklehrern in aufeinanderfolgenden Stunden zum Thema Optik untersucht. Die Studie zeigt wie Videoanalysen genutzt werden können, um Belege für einen Aspekt des fachdidaktischen Wissens der Lehrpersonen zu sammeln: Ihre Nutzung von inhaltlichem Wissen in der Interaktion mit den Schülerinnen und Schülern. In dieser Studie werden drei potentiell wichtige Charakteristika dieses Aspekts des fachdidaktischen Wissens identifiziert: Flexibilität, Reichhaltigkeit und Schülerorientierung. Durch die Gegenüberstellung von Lehrpersonen mit hohem und niedrigem Wissens‐ und Interessenzuwachs wurden potentielle Mechanismen untersucht, durch die dieser Aspekt des fachdidaktischen Wissens die Lernergebnisse von Schülerinnen und Schülern beeinflussen kann. Die Lehrerausbildung in Deutschland betont das inhaltliche Wissen stärker als das fachdidaktische Wissen. Die ausgewählten Fälle beschreiben, welche Unterstützung Lehrpersonen mit einem hohen fachlichen Wissen benötigen, um dieses Wissen so zu verändern, dass es für das Unterrichten genutzt werden kann. © 2012 Wiley Periodicals, Inc. J Res Sci Teach 49: 1211–1239, 2012
From the contribution to the action approach: White teachers' experiences influencing the development of multicultural science curricula
Authors: Suriel Regina L. , Atwater Mary M.
Published: October 2012

In this exploratory case study, we sought to understand teacher's integration of multicultural curricula in science curriculum units, and how personal experiences influenced the level of integration in light of Bank's typology of ethnic content integration into school curricula. Five research participants volunteered and were selected so as to be representative of the demographic of pre‐service and in‐service teachers in the southern United States. The aim was to explore teachers' personal experiences with cultural others that either facilitated or impeded their adoption of multicultural curricula strategies in science curricula units. Case narratives present and discuss interview data and assigned curricula projects. Findings suggest that participants who had transformative cultural experiences and who identified as the marginalized cultural other, transformed science curricula at higher levels of Bank's typology for curricula' multicultural approaches. © 2012 Wiley Periodicals, Inc. J Res Sci Teach 49: 1271–1295, 2012
Service provided by fading MIMO channels: a deterministic perspective
Authors: Dong Yunquan , Fan Pingyi , Letaief Khaled Ben
Published: October 2012

In this paper, we study the channel service process of a multiple‐input multiple‐output (MIMO) system over an independent and identically distributed (i.i.d.) fading channel. One key problem of communication over fading MIMO channels is what kind of service the MIMO channel can provide. In this paper, this problem is investigated in terms of channel service process. Assuming that the channel state information is available at the receiver, the channel service process S(t) is defined as the integral of the instantaneous channel capacity over a time interval of length t, which specifies the service provided by the channel during the period. Using the characteristic function approach and the infinitely divisible law, it is proved that the channel service process S(t) is a deterministic linear function of time t, other than any curve form or a stochastic process. Specifically, , where is a constant equal to the corresponding ergodic capacity. This result has two implications: (i) i.i.d. fading MIMO channels can support a constant rate traffic stream of rate without higher layer transmission delay; (ii) the ergodic capacity is the actual transmission capacity of the fading channel, other than only a statistical average value. Copyright © 2012 John Wiley & Sons, Ltd.
Microwave‐Assisted Synthesis, Characterization, and Thermal Decomposition of Rare‐Earth Metal Disulfides RES2 (RE = La, Pr, Nd)
Authors: Bartsch Christian , Ahrens Eike , Doert Thomas
Published: October 2012

Microwave‐assisted metathesis reactions from anhydrous rare‐earth metal trichlorides and alkali metal polychalcogenides in dimethylformamide in the temperature interval 160 °C ≤ T ≤ 220 °C yield sub‐micron and nanometer scaled particles of the rare‐earth metal disulfides RES2 (RE = La, Pr, Nd). The samples were characterized by X‐ray powder diffraction, electron microscopy, chemical analysis, and Raman and UV/Vis spectroscopy. The products adopt the monoclinic α‐RES2 type (space group P21/a) and form desert rose‐like agglomerates. The nano‐scaled samples show significantly reduced optical bandgaps compared to the bulk material. The thermal decomposition in air at 550 °C ≤ T ≤ 1000 °C yields rare‐earth metal oxide sulfates RE2O2SO4.
Properties of Biobased Epoxy Resins from Epoxidized Soybean Oil (ESBO) Cured with Maleic Anhydride (MA)
Authors: España J. M. , Sánchez‐Nacher L. , Boronat T. , Fombuena V. , Balart R.
Published: October 2012

Epoxidized soybean oil (ESBO), obtained from a renewable resource was used in the production of thermoset resins. Samples of the ESBO were initially treated with maleic anhydride, equal mixture of catalyst (1,3‐butanediol anhydrous and benzyldimethylamine) and the mixture was cured for 5 h at different temperatures. After the curing process, the ratio between the ESBO and the anhydride (ratio EEW:AEW) was evaluated in terms of the different mechanical properties produced using flexural, Shore D hardness and Charpy impact tests. The sample with the best mechanical properties was that with an EEW:AEW ratio of 1:1.0 which leads to best balanced behavior and this could be representative for the maximum crosslinking degree. Also, thermal characteristics were evaluated during the crosslinking process using differential scanning calorimetry, In addition, other thermal characteristics of the cured materials were obtained by determining the heat deflection temperature and the Vicat softening temperature. The coefficient of thermal expansion was determined using thermo‐mechanical analysis. In accordance with the mechanical behavior, the best thermal properties were obtained for samples with an EEW:AEW ratio of 1:1.0. As a result of this work, a biologically based epoxy resin with good mechanical properties and flexibility was obtained.
Analysis of Ceramides in Soy Sauce Oil
Authors: Yamaguchi Hitomi , Ogawa Yoshihiro
Published: October 2012

Soy sauce oil is a by‐product of soy sauce derived from the lipids in soybeans, wheat, and koji mold (Aspergillusoryzae or A. sojae). In the present study, sphingolipids were detected in soy sauce oil for the first time. The concentration of sphingolipids as sphingoid bases was 240 ± 50 mg/kg. Ceramide was the major component, and free sphingoid bases and cerebroside were minor components. The abundance ratios of the incorporated sphingoid bases were as follows: 4‐hydroxysphinganine (t18:0), 13 %; 4‐hydroxy‐8‐sphingenine (t18:1Δ8), 29 %; sphinganine (d18:0), 4.7 %; 8‐sphingenine (d18:1Δ8), 18 %; 4,8‐sphingadienine (d18:2Δ4,Δ8), 16 %; 9‐methyl‐trans‐4,trans‐8‐sphingadienine (9‐Me d18:2Δ4,Δ8), 19 %; and trans‐4‐sphingenine (d18:1Δ4), 1.2 %. Two of the incorporated sphingoid bases (t18:1Δ8 and d18:1Δ8) were isolated and another (d18:2Δ4,Δ8) was partly purified, while three of the ceramides were isolated and identified. The structures of the other ceramides were determined by liquid chromatography‐mass spectrometry. Two groups of ceramides were observed, including one group containing t18:0, t18:1Δ8, d18:1Δ8, d18:2Δ4,Δ8, and 9‐Me d18:2Δ4,Δ8 with 2‐hydroxy fatty acids and the other containing t18:0 and t18:1Δ8 with normal fatty acids. Many of these ceramides corresponded to ceramides or ceramide moieties of cerebrosides found in the soybeans, wheat, and koji mold used in soy sauce production.
Fatty Acid Composition of Non‐Starch and Starch Neutral Lipid Extracts of Portuguese Sourdough Bread
Authors: Rocha João M. , Kalo Paavo J. , Malcata F. Xavier
Published: October 2012

Fatty acids in each neutral lipid (NL) class from non‐starch (NSL) and starch lipids (SL) were quantified in maize and rye flours, and sourdough—to ascertain the effect of mixing, and between sourdough and broa (a traditional Portuguese sourdough bread)—to assess the effect of fermentation. Maize and rye flour lipid extracts showed distinct fatty acid profiles. Maize flour exhibited a higher amount of most fatty acid species and of total NL—where triacylglycerols (TAG) and free fatty acids (FA) represented the dominant NL. The fatty acid profiles varied throughout breadmaking (i.e. from the mixture of flours with water, through fermentation until baking): in NSL, the highest concentrations were found in the flour mixture (i.e. 59 % of maize and 41 % of rye flour) or sourdough, whereas in SL they were found in broa; additionally, SL levels increased, and NSL levels decreased during dough preparation and baking. Palmitic (C16:0), oleic (C18:1) and linoleic (C18:2) acids were the major fatty acids in all food items. Cumulative percentages of C16:0, C18:1 and C18:2 in NSL and SL were over 81 and 75 %, respectively, in the flour mixture, 86 and 66 % in sourdough, and 83 and 82 % in broa. In particular, C18:2 accounted for 52 % of the total fatty acids. The content of sterol esters remained essentially constant throughout fermentation and baking; those of TAG decreased from flours to fermentation, while diacylglycerol and monoacylglycerol increased; the NL fractions were essentially unaffected by baking, yet their FA contents increased.
Creb is modulated in the mouse superior colliculus in developmental and experimentally‐induced models of plasticity
Authors: Vierci Gabriela , De Oliveira Camila Salum , Perera Lucia Ruiz , Bornia Natalia , Leal Rodrigo Bainy , Rossi Francesco Mattia
Published: October 2012

In the central nervous system long‐term plastic processes need the activation of specific gene expression programs and the synthesis of new protein in order to occur. A transcription factor fundamental for several plasticity mechanisms in various CNS areas is the cAMP response element‐binding protein, CREB. This factor is activated through phosphorylation at its Serine 133 residue by multiple signaling pathways. Little is known about CREB role in the superior colliculus, a midbrain area considered an experimentally useful model for the study of neuronal plasticity processes. In the present work we studied by Western blot analysis the modulation of CREB expression and activation in the mouse superior colliculus in three models of neuronal plasticity: (1) developmental plasticity; (2) lesion‐induced plasticity; (3) and fluoxetine‐induced restored plasticity. We used an antibody that detects endogenous level of the total CREB protein (anti‐TCREB) to identify possible modulations at CREB expression level, and a second antibody (anti‐PCREB) that detects endogenous level of CREB only when it is phosphorylated at Ser133, to identify modifications of CREB activation state. The results showed that: (1) the expression and activation of CREB increase during the development of the superior colliculus in temporal correlation with the plastic process of refinement of retino‐collicular projections; (2) the activation of CREB is induced by a monocular lesion performed during the critical period for plasticity in young animals but not when performed in less plastic juvenile mice; (3) the expression and activation of CREB increase in adult animals treated with fluoxetine, known to restore high levels of plasticity in adult animals. These results suggest that CREB transcription factor plays a fundamental role in plasticity processes also at the level of the mouse superior colliculus.
Environmental Health Ethics
Authors: Resnik David B.
Published: October 2012

Environmental Health Ethics illuminates the conflicts between protecting the environment and promoting human health. In this study, David B. Resnik develops a method for making ethical decisions on environmental health issues. He applies this method to various issues, including pesticide use, antibiotic resistance, nutrition policy, vegetarianism, urban development, occupational safety, disaster preparedness and global climate change. Resnik provides readers with the scientific and technical background necessary to understand these issues. He explains that environmental health controversies cannot simply be reduced to humanity versus environment and explores the ways in which human values and concerns - health, economic development, rights and justice - interact with environmental protection.
Skull base osteomyelitis: current microbiology and management
Authors: Spielmann P M , Yu R , Neeff M
Published: October 2012

Introduction:

Skull base osteomyelitis typically presents in an immunocompromised patient with severe otalgia and otorrhoea.Pseudomonas aeruginosais the commonest pathogenic micro-organism, and reports of resistance to fluoroquinolones are now emerging, complicating management. We reviewed our experience of this condition, and of the local pathogenic organisms.

Methods:

A retrospective review from 2004 to 2011 was performed. Patients were identified by their admission diagnostic code, and computerised records examined.

Results:

Twenty patients were identified. A facial palsy was present in 12 patients (60 per cent). Blood cultures were uniformly negative, and culture of ear canal granulations was non-diagnostic in 71 per cent of cases.Pseudomonas aeruginosawas isolated in only 10 (50 per cent) cases; one strain was resistant to ciprofloxacin but all were sensitive to ceftazidime. Two cases of fungal skull base osteomyelitis were identified. The mortality rate was 15 per cent. The patients’ treatment algorithm is presented.

Conclusion:

Our treatment algorithm reflects the need for multidisciplinary input, early microbial culture of specimens, appropriate imaging, and prolonged and systemic antimicrobial treatment. Resolution of infection must be confirmed by close follow up and imaging.
Party Systems and Government Stability in Central and Eastern Europe
Authors: Grotz Florian , Weber Till
Published: October 2012

After two decades of parliamentary democracy, the countries of Central and Eastern Europe (CEE) have quite different records of government stability. At the same time there continues to be turbulent fluctuation within the individual countries. To explain this variation, the authors draw on characteristics of parties and party systems for 138 governments in 12 CEE countries. The analysis is structured by two distinct logics that underlie the effect of party-related attributes on government survival: the logic of internal friction within the government and the logic of external pressure from the opposition. The authors argue that in the “difficult” contexts of postcommunist party systems, these two logics do not operate independently of each other. Instead, they suggest that standard theory needs to be revised to account for the interactions of government and opposition characteristics. Their model of these interactions not only includes standard numeric and ideological variables but also integrates specificities of the postcommunist context: the regime divide and the low degree of party-system consolidation. Quantitative and qualitative findings demonstrate that government stability in CEE is interactively determined by whole constellations of party attributes.
Relativistic and ponderomotive self-focusing of a laser pulse in magnetized plasma
Authors: Sharma Anamika , Tripathi V.K.
Published: October 2012

The self-focusing of an intense right circularly polarized Gaussian laser pulse in magnetized plasma is studied. The ions are taken to be immobile and relativistic mass effect is incorporated in both the plasma frequency (ωp) and the electron cyclotron frequency (ωc) while determining the ponderomotive force on electrons. The ponderomotive force causes electron expulsion when the effective electron cyclotron frequency is below twice the laser frequency. The nonlinear plasma dielectric function due to ponderomotive and relativistic effects is derived, which is then employed in beam-width parameter equation to study the self-focusing of the laser beam. From this, we estimate the importance of relativistic self-focusing in comparison with ponderomotive self-focusing at moderate laser intensities. The beam width parameter decreases with magnetic field indicating better self-focusing. When the laser intensity is very high, the relativistic gamma factor can be modeled as ${\rm \gamma} = 0.8\left({{{{\rm \omega} _c } / {\rm \omega} }} \right)+ \sqrt {1 + a_0^2 }$γ=0.8(ωc/ω)+1+a02 where ω and a0 are the laser frequency and the normalized laser field strength, respectively. The cyclotron effects on the self-focusing of laser pulse are reduced at high field strengths.
Virulence and antimicrobial resistance genes in human MRSA ST398 isolates in Austria
Authors: ZARFEL G. , KRZIWANEK K. , JOHLER S. , HOENIGL M. , LEITNER E. , KITTINGER C. , MASOUD L. , FEIERL G. , GRISOLD A. J.
Published: October 2012

This study determined the genetic background of virulence and resistance genes of MRSA ST398 in Austria. From 2004 up to 2008 a total of 41 human isolates of MRSA ST398 were investigated for virulence and resistance gene patterns using DNA microarray chip analysis. Highly similar virulence gene profiles were found in 29 (70·7%) of the isolates but genes encoding Panton–Valentine leukocidin, enterotoxins, or toxic shock syndrome toxin were not detected. Genes conferring resistance to tetracycline and erythromycin-lincosamide were common as all but one of the isolates exhibited tetM and/or tetK, which are involved in tetracycline resistance, and 12 (29·9%) were positive for ermC, conferring resistance to erythromycin/lincosamide. SplitsTree analysis showed that 40 isolates were closely related. Changes in virulence and resistance gene patterns were minimal over the observed time period.
Cardiac findings and long-term thromboembolic outcomes following pulmonary embolism in children: a combined retrospective-prospective inception cohort study
Authors: Hancock Hayley S. , Wang Michael , Gist Katja M. , Gibson Elizabeth , Miyamoto Shelley D. , Mourani Peter M. , Manco-Johnson Marilyn J. , Goldenberg Neil A.
Published: October 2012

In paediatric pulmonary embolism, cardiac findings and thromboembolic outcomes are poorly defined. We conducted a mixed retrospective-prospective cohort study of paediatric pulmonary embolism at the Children's Hospital Colorado between March, 2006 and January, 2011. A total of 58 consecutive children – age less than or equal to 21 years – with acute pulmonary embolism were enrolled. Data collection included clinical and laboratory characteristics, treatments, serial echocardiographic and electrocardiographic findings, and outcomes of pulmonary embolism non-resolution and recurrence. The median age was 16.5 years ranging from 0 to 21 years. The most prevalent clinical risk factors were oral contraceptive pill use (52% of female patients), presence of a non-infectious inflammatory condition (21%), and trauma (21%). Thrombophilias included heterozygous factor V Leiden in 21%; antiphospholipid antibody syndrome was established in 31% overall. Proximal pulmonary artery involvement was present in 34%. At presentation, nearly half of the patients had hypoxaemia and 37% had tachycardia. The classic electrocardiographic finding of S1Q3T3 was present in 12% acutely; tricuspid regurgitation greater than 3 metres per second, septal flattening, and right ventricular dilation were each present on acute echocardiogram in 25%. Nearly all patients received therapeutic anticoagulation, with initial systemic tissue plasminogen activator administered in 16% for occlusive iliofemoral deep venous thrombosis and/or massive pulmonary embolism. Pulmonary embolism resolution was observed in 82% by 6 months. Recurrent pulmonary embolism occurred in 9%. There were no pulmonary embolism-related deaths. Right ventricular dysfunction was rare in follow-up. These data indicate that acute heart strain is common, but chronic cardiac dysfunction is rare, following aggressive management of acute pulmonary embolism in children.
Pre-R Dentalisation in northern England
Authors: MAGUIRE WARREN
Published: October 2012

Dental pronunciation of alveolar consonants before /r/ and /ər/ is a well-known feature of traditional varieties of Irish English. ThisPre-R Dentalisation(PreRD) has a number of intriguing linguistic properties, in particular an associated /r/-Realisation Effectand aMorpheme Boundary Constraint. It is less well known that PreRD is (or perhaps was) also a feature of a number of English varieties outside Ireland, particularly in traditional northern English dialects. This article analyses dialect data from northern England in order to determine the nature of PreRD there and its historical relations with the phenomenon in Irish English. In addition, it explores the phonological complexities of PreRD in light of the loss of rhoticity in traditional northern English dialects.
Preposition copying and pruning in present-day English
Authors: RADFORD ANDREW , FELSER CLAUDIA , BOXELL OLIVER
Published: October 2012

This article investigates the nature of preposition copying and preposition pruning structures in present-day English. We begin by illustrating the two phenomena and consider how they might be accounted for in syntactic terms, and go on to explore the possibility that preposition copying and pruning arise for processing reasons. We then report on two acceptability judgement experiments examining the extent to which native speakers of English are sensitive to these types of ‘error’ in language comprehension. Our results indicate that preposition copying creates redundancy rather than ungrammaticality, whereas preposition pruning creates processing problems for comprehenders that may render it unacceptable in timed (but not necessarily in untimed) judgement tasks. Our findings furthermore illustrate the usefulness of combining corpus studies and experimentally elicited data for gaining a clearer picture of usage and acceptability, and the potential benefits of examining syntactic phenomena from both a theoretical and a processing perspective.
Never again: the multiple grammaticalization ofneveras a marker of negation in English
Authors: LUCAS CHRISTOPHER , WILLIS DAVID
Published: October 2012

In both standard and nonstandard varieties of English there are several contexts in which the wordneverfunctions as a sentential negator rather than as a negative temporal adverb. This article investigates the pragmatic and distributional differences between the various non-temporal uses ofneverand examines their synchronic and historical relationship to the ordinary temporal quantifier use, drawing on corpora of Early Modern and present-day British English. Primary focus is on (i) a straightforward negator use that in prescriptively approved varieties of English has an aspectual restriction to non-chance, completive achievement predicates in the preterite, but no such restriction in nonstandard English; and (ii) a distinct categorical-denial use that quantifies over possible perspectives on a situation. Against Cheshire (1998), it is argued that neither of these uses represents continuity with non-temporal uses ofneverin Middle English, but both are instead relatively recent innovations resulting from semantic reanalysis and the semanticization of implicatures.