bluuebunny/crossref_metadata_2025 huggingface dataset:
La fortune littéraire du Journal de voyage de Saint-Luc de La Corne
Authors: Lespérance Pierre
Published: July 2012

Résumé

Le journal de voyage que Saint-Luc de La Corne écrivit en 1762 et fit publier à Montréal en 1778 constitue le premier jalon de l'histoire littéraire québécoise. Peu à peu oublié, le récit du naufrage de /'Auguste survécut dans la première moitié du xix3 siècle grâce à la tradition orale dont il fut l'objet dans la famille Aubert de Gaspê. À compter des années I860, la postérité se saisit du texte de La Corne. D'Aubert de Gaspépère à Robert de Roquebrune, en passant par Henri-Raymond Casgrain, Archibald MacMechan et Pierre-Georges Roy, les hommes de lettres apportent à l'épisode de /'Auguste des développements qui modifient jusqu'à l'esprit de l'oeuvre de La Corne. À mesure que ce jeu hypertextuel s'effectue, l'enjeu devient de plus en plus clairement idéologique dans la mesure où les littérateurs utiliseront l'effet La Corne pour alimenter leurs thèses respectives.
Un discours « exemplaire » : la biographie de François-Xavier Garneau par Henri-Raymond Casgrain
Authors: Bourassa Yves , Marcotte Hélène
Published: July 2012

Résumé

Dans son article "Le mouvement littéraire en Canada", Henri-Raymond Casgrain invoque le ministère futur de la littérature canadienne-française: elle fortifiera l'identité de la nation et propagera les thèses du catholicisme. Or, au XIXe siècle, le genre biographique fait partie intégrante de l'activité littéraire et se voit ainsi départi les mêmes visées idéologiques. Le présent article vise à démontrer que la biographie de Casgrain consacrée à l'historien national François-Xavier Garneau répond à une volonté duelle d'édification nationale et religieuse, volonté qui se manifeste principalement par le recours à deux procédés : la mythification et l'examen critique.
Aimer et raconter dans La fête du désir
Authors: Gaudet Gérald
Published: July 2012

Gerald Gaudet, Université du Québec à Trois-Rivières

En se tournant du côté de l'intime, les romanciers des années quatre-vingt et quatre-vingt-dix se sont éloignés de la problématique nationale. Souvent confrontés à l'autre en eux-mêmes, les personnages entreprennent un retour vers l'origine, par lequel ils tentent de se réapproprier ce qui a pu être mal compris, vécu ou nommé. La fête du désir, de Madeleine Ouellette-Michalska, est un roman emblématique de cette période. Avec son amant, la narratrice déconstruit les logiques traditionnelles. Elle emprunte à la poésie et au langage de l'inconscient des dispositifs pour oser l'impossible : se libérer des limites de l'âge, du sexe et de l'apprentissage. Comment redevenir l'enfant du désir? Comment accepter une légitimité autre? Avec ces questions qui prennent leur ancrage dans la psychanalyse, l'auteure ouvre la voie à une relecture de l'histoire du roman québécois, nourrie par la question des genres.
La route d’Altamont de Gabrielle Roy, épave de La Saga d’Éveline?
Authors: Robinson Christine
Published: July 2012

Cet article a pour but de situer La route d'Altamont, oeuvre publiée en 1966, par rapport à La Saga d'Éveline, roman inédit et inachevé de Gabrielle Roy, composé entre 1945 et 1965 environ. Cette oeuvre inédite prend comme point de départ la migration d'une famille québécoise au Manitoba, épisode évoqué à plusieurs reprises dans La route d'Altamont. Peut-on dès lors considérer celle-ci comme une épave de La Saga d'Éveline ? On peut établir entre les deux oeuvres des liens intertextuels sur divers plans. Cependant, La Saga d'Éveline et La route d'Altamont apparaissent comme deux oeuvres autonomes qui se distinguent, entre autres, par leur propos : la première s'intéresse surtout au thème du mariage et de la maternité, la seconde, aux relations mère-fille. En somme, La route d'Altamont peut être considérée comme une épave du roman inachevé, et lue comme un récit de deuil, où Gabrielle Roy fait ses adieux à son projet de saga.
Langue et idéologie dans les textes de Gabrielle Roy publiés pour les enfants
Authors: Romney Claude
Published: July 2012

Le présent article étudie la langue de quatre contes de Gabrielle Roy qui ont été publiés pour les enfants bien qu'ils n'aient pas été écrits à leur intention. Une analyse lexicale montre que le premier de ces textes véhicule, de façon plus subjective que les autres, une idéologie qui, d'une part, correspond à celle de la société à laquelle appartenait l'écrivaine dans son enfance, mais qui, d'autre part, traduit le regard qu'elle porte en tant qu'adulte sur cette période de sa vie. Les trois autres récits expriment davantage sa vision personnelle et prônent explicitement la réconciliation et l'harmonie des bêtes comme des êtres humains, ainsi que les bienfaits de la liberté. Ce message qui sous-tend toute l'oeuvre de la romancière paraît particulièrement bien adapté à de jeunes lecteurs.
La référence à la Tradition dans la production d’une « théologie morale » : illustration d’un cas
Authors: Guindon André
Published: July 2012

La production d’un discours éthique dans un domaine aussi inexploré que la nudité donne l’occasion d’examiner à neuf la référence à la Tradition dans une telle entreprise. Une approche « éthique » des textes fondateurs n’y a produit que du matériau apte à construire une histoire des moeurs de dénudation. Une approche « théologique », en accueillant l’expérience de Dieu chez les témoins chrétiens, identifie l’autorité propre à la Tradition dans le discours éthique. Révélation des « moeurs divines », la Tradition guide le discernement des pratiques morales de dénudation (ou de tout autre agir moral) qui sont de nature à initier chrétiennes et chrétiens à l’Ineffable Mystère.
Advanced Models for Finite Element Analysis of Composite Materials
Authors: Oller Sergio , Oñate Eugenio
Published: July 2012

In this article, we review some of the more advanced theories for modeling and analysis of composite materials with the finite element method. In the first part of the article, we describe the serial/parallel (SP) mixing theory as a general framework for combining the individual mechanical properties of the material constituents in a single constitutive model. A procedure for incorporating material anisotropy and fiber‐matrix debonding effects in the SP theory is described. In the second part of the article, we describe homogenization methods based on multiscale theory for finite element analysis of the behavior of composite materials at micro‐ and macroscale levels. The capability of the SP theory to model delamination and interlaminar crack propagation in laminated composites is shown in an example of application.
Fatigue Strength Distribution of Carbon Fiber
Authors: Zhou Yuanxin
Published: July 2012

In this investigation, an experimental approach was developed to characterize the fatigue strength distribution of carbon fibers using fiber bundles test. In this method, survival probability,
P
, of the fiber bundles was first calculated from the stress reductions at different cycles in strain‐controlled fatigue tests. On the basis of a fiber bundles model and fatigue P‐strain‐N curves, the fatigue strength exponent,
b
, Weibull scale parameter σ
0
, and Weibull shape parameter β were then determined to characterize the fatigue strength distribution of carbon fiber. A numerical model, based on Monte Carlo simulation, was also established to predict the load‐controlled fatigue failure process of fiber bundles. The simulated strain–cycle number curves and S–N curves based on the model developed are in good agreement with the test data.
Polyetherimide Matrix Resins and Composites
Authors: Pratte James
Published: July 2012

Polyetherimide (PEI) polymers have, since their discovery, increasingly found usage in a variety of applications that require high temperature performance with good processability. The combination of being able to be melt and solvent processed has resulted in a variety of composite product forms that can be cost effectively converted into high performance composite parts. This article reviews the performance, processability, and applications of currently available commercial PEI‐matrix‐based composite materials. The article also discusses the constituent polymer properties and how those properties are used in the performance and processing of these materials.
Polystyrylpyridine Resins and CompositesAdapted from
Polystyrylpyridine Resins and Composites
, First Edition.
Authors: Bloch Bertrand , Maquart Jean‐Gabriel
Published: July 2012

In this article, polystyrylpyridines (PSP resins) are presented. A discussion on the chemical aspects introduces these materials; then in the first part of the article, synthesis and processing of PSP resins are introduced. In particular, PSP prepolymers are obtained by heating nearly equimolecular mixtures of terephtaldialdehyde and sym‐collidine in the presence of an acidic catalyst. However, to improve the performance or processing conditions, several modifications have been brought to the standard collidine‐terephtaldialdehyde composition, and some examples of modified styrylpyridine resin are presented in the aricle.

In the second part of the article, uses and applications as matrices for composites are discussed. In particular, some commercially available resin are introduced, and finally, a discussion on economic aspects and safety factors of their uses is reported.
Processing and Mechanical Properties of the Workpiece in Machining of Long‐Fiber‐Reinforced Composites
Authors: Miguélez Maria Henar , Santiuste Carlos , Soldani Xavier , Loya Jose Antonio
Published: July 2012

This work focuses on the analysis of the influence of mechanical properties of long fiber reinforced polymeric composite (LFRP) on machining operations. Experimental works covering main aspects of the machining process, such as tool selection, wear evolution, and cutting parameters were briefly reviewed. It can be concluded from this analysis that the composite properties strongly influence machining process. The selection of the tool, both cutting material and geometry, should be done depending on the type of composite family (carbon, glass, or aramid). This aspect also influences the evolution and mechanism of tool wear.

On the other hand, numerical modeling is a useful tool to get a better knowledge of machining operations. Mechanisms of chip generation, cutting forces, and damage can be evaluated depending on the workpiece properties. Finite element approach involves modeling the mechanical behavior of the composite, material properties influence damage generation through the models formulation.
Pultrusion
Authors: Vázquez Analía , Escobar Mariano
Published: July 2012

This article involves the principal aspects of the pultrusion of both thermosetting and thermoplastic polymer matrix. After a short introduction, in the first part, the pultrusion machine for thermosetting polymer matrix is described, followed by the modeling of processing parameters. The influence of pulling velocity, fiber type, residual thermal stress, additives, and fillers is studied. Also, the importance of controlling the temperature profile in order to allow for proper gelation and curing of the thermosetting resin is emphasized. The second part describes the pultrusion of thermoplastic polymer matrix with the same structure of the first one. At the end, examples of structures pultruded using cement and foams as matrix are included.
Shear Properties of Polymers and Composites
Authors: Piggott Michael R.
Published: July 2012

The yield stress of polymers is pressure dependent, unlike that of metals. So this stress in polymers has to be defined by an inverse rule of mixtures expression. In addition, an overwhelming number of polymers fail by tensile crack propagation when sheared. This is true for most of the polymers used for fiber reinforcement. So the failure of laminates under shear loading is complex, involving some polymer tensile fracture together with some fiber flexure and tensile fracture as well. V notch and two‐rail shear data are given for a range of unidirectional and multidirectional laminates. Shear delamination results are also discussed.
Short‐Fiber Thermoplastics Composites: Fiber Fracture During Melt Processing
Authors: Vaxman Anita , Narkis Moshe , Siegmann Arnon , Kenig Samuel
Published: July 2012

Conventional short‐fiber thermoplastic compounds (fiber length usually <1 mm) are manufactured by incorporation of short fibers into thermoplastic resins either by dry blending, before injection molding (IM), or by extrusion compounding, using single‐ or twin‐screw extruders. In extrusion compounding, the matrix resin and chopped fibers are melt mixed in an extruder, stranded, and pelletized. The high shear extrusion compounding process leads to significant fiber breakage. The length reduction decreases the reinforcement efficiency of the fibers. Experiments are described and the literature is reviewed, which characterize fiber length reduction in conventional processes. Fiber fracturing and attrition during processing are caused by stressed induced on the fiber by the melt flow conditions and stresses resulting from fiber‐fiber and fiber‐surface interactions. Fiber breakup is significant in recycling of fiber‐reinforced thermoplastics. Fiber attrition and fracture during melt compounding and subsequent melt processing operations are important phenomena that determine the final composite properties. In order to overcome this limitation, long‐fiber‐reinforced thermoplastics (LFT) have been developed to yield better mechanical properties and to meet the market demand by improvement of the reinforcement efficiency. This article reviews theoretical and experimental studies dealing with fiber breakage during melt flow compounding and processing of fiber‐reinforced thermoplastic composites.
On the Cognitive Benefits of Cultural Experience: Exploring the Relationship between Studying Abroad and Creative Thinking
Authors: Lee Christine S. , Therriault David J. , Linderholm Tracy
Published: July 2012

Drawing from research that shows a positive relationship between multicultural experiences and creative cognition, the present study investigates creative thinking as a possible cognitive benefit gained from studying abroad. The domain generality and specificity of creative thinking is also explored. Undergraduate students completed a general measure and a culture specific measure of creative thinking. Performance on the two creative thinking tasks were compared between students who have studied abroad, students who are planning to study abroad, and students who have not and do not plan to study abroad. Results showed that students who studied abroad outperformed the two groups of students who did not study abroad on both the general and culture specific measures of creative thinking. Findings from this study provide evidence that studying abroad supports complex cognitive processes that underlie creative thinking in culture specific and domain general settings. Copyright © 2012 John Wiley & Sons, Ltd.
Visualising Ecological Literacy
Authors: Boehnert Jody
Published: July 2012

For over two decades, ecological literacy has sought to integrate foundational premises for addressing environmental problems. Here Jody Boehnert of EcoLabs explains how she has developed graphics resources and tools for designers in order for them to understand the perceptual shifts that are necessary to learn the causality and complexity of ecology and how it is embedded in human relations.
Beyond the Scarcities of Affluence: An ‘Alternative Hedonist’ Approach
Authors: Soper Kate
Published: July 2012

Kate Soper describes how at a time when the gap between the rich and poor has grown wider, scarcity has become a product of affluence in a double sense. Not only is consumption using up material and energy resources for everyone, for the wealthiest section of the world's population the pleasures of consumption are also being paid for by the dearth of life's other qualities, such as sufficient leisure time, good health and an environment free of pollution and congestion.
Risk for myasthenia gravis maps to a 151Pro→Ala change in TNIP1 and to human leukocyte antigen‐B*08
Authors: Gregersen Peter K. , Kosoy Roman , Lee Annette T. , Lamb Janine , Sussman Jon , McKee David , Simpfendorfer Kim R. , Pirskanen‐Matell Ritva , Piehl Frederik , Pan‐Hammarstrom Qiang , Verschuuren Jan J. G. M. , Titulaer Maarten J. , Niks Erik H. , Marx Alexander , Ströbel Philipp , Tackenberg Björn , Pütz Michael , Maniaol Angelina , Elsais Ahmed , Tallaksen Chantal , Harbo Hanne F. , Lie Benedicte A. , Raychaudhuri Soumya , de Bakker Paul I. W. , Melms Arthur , Garchon Henri‐Jean , Willcox Nicholas , Hammarstrom Lennart , Seldin Michael F.
Published: July 2012

Objective:

The objective of this study is to comprehensively define the genetic basis of early onset myasthenia gravis (EOMG).

Methods:

We have carried out a 2‐stage genome‐wide association study on a total of 649 North European EOMG patients. Cases were matched 1:4 with controls of European ancestry. We performed imputation and conditional analyses across the major histocompatibility complex, as well as in the top regions of association outside the human leukocyte antigen (HLA) region.

Results:

We observed the strongest association in the HLA class I region at rs7750641 (p = 1.2 × 10−92; odds ratio [OR], 6.25). By imputation and conditional analyses, HLA‐B*08 proves to be the major associated allele (p = 2.87 × 10−113; OR, 6.41). In addition to the expected association with PTPN22 (rs2476601; OR, 1.71; p = 8.2 × 10−10), an imputed coding variant (rs2233290) at position 151 (Pro→Ala) in the TNFAIP3‐interacting protein 1, TNIP1, confers even stronger risk than PTPN22 (OR, 1.91; p = 3.2 × 10−10).

Interpretation:

The association at TNIP1 in EOMG implies disease mechanisms involving ubiquitin‐dependent dysregulation of NF‐κB signaling. The localization of the major HLA signal to the HLA‐B*08 allele suggests that CD8+ T cells may play a key role in disease initiation or pathogenesis. ANN NEUROL 2012;
Substantia nigra depigmentation and exposure to encephalitis lethargica
Authors: Hack Nawaz , Jicha Gregory A. , Abell Annalisa , Dean Dawson , Vitek Jerrold L. , Berger Joseph R.
Published: July 2012

Objective:

Parkinsonism has occasionally been reported as a consequence of infectious diseases. The present study examines the clinical and pathological correlates of parkinsonism across birth cohorts in relation to critical exposure to the encephalitis lethargica epidemic in the early 1900s.

Methods:

The study population consisted of 678 participants in the Nun Study, of whom 432 died and came to autopsy. Qualitative indices of substantia nigra (SN) depigmentation were verified in a subset of 40 randomly selected subjects using quantitative stereological techniques. SN depigmentation, detected neuropathologically, was correlated with clinical parameters of Parkinson disease, age, and birth cohort.

Results:

SN depigmentation was detected in 57 (13.2%) of the cohort. Although qualitative SN depigmentation correlated modestly with age (p = 0.02), it correlated best with birth cohort (p = 0.009) for women born in the years 1895–1899. Quantitative measures of SN depigmentation were increased in this birth cohort compared to age matched subjects from flanking birth cohorts 1890–1894 and 1900–1904 (p < 0.001). SN depigmentation correlated with speed of 6‐ and 50‐foot walk (p < 0.0001), up and go test (p < 0.0001), and hand coordination (p < 0.0001).

Interpretation:

Subjects in the birth cohort 1895–1899 would have been in their late teens and 20s at the onset and during the peak of the encephalitis lethargica epidemic. These were precisely the age ranges of persons who were most often affected by the illness. These data suggest the possibility that the coexistence of parkinsonism and SN depigmentation in this birth cohort may have resulted from the yet undetermined infectious agent responsible for encephalitis lethargica. ANN NEUROL 2012;72:912–917
“Intelligente” Biomaterialien durch Selbstorganisation von Hybridhydrogelen
Authors: Kopeček Jindřich , Yang Jiyuan
Published: July 2012

Hybridbiomaterialien sind Systeme, die aus Bausteinen von mindestens zwei individuellen Molekülklassen erzeugt werden, z. B. aus synthetischen Makromolekülen sowie Proteinen oder Peptiddomänen. Die synergistische Kombination von zwei Strukturarten kann neue Materialien ergeben, die einen beispiellosen Grad an struktureller Organisation sowie neuartige Eigenschaften aufweisen. Dieser Aufsatz diskutiert die durch Bioerkennung gesteuerte Selbstorganisation von hybriden Makromolekülen zu funktionalen Hydrogel‐Biomaterialien. Zuerst werden die grundlegenden Regeln besprochen, die die Sekundärstruktur von Peptiden bestimmen, und im Anschluss bewerten wir die Ansätze zur spezifischen Entwicklung von Hybridsystemen mit maßgeschneiderten Eigenschaften. Nach einer Diskussion der Ähnlichkeiten der verschiedenen Designprinzipien für Biomaterialien und makromolekulare Therapeutika werden wir die zukünftige Entwicklung dieses Forschungsgebietes kurz zusammenfassen.
Functional Block Copolymers: Nanostructured Materials with Emerging Applications
Authors: Schacher Felix H. , Rupar Paul A. , Manners Ian
Published: July 2012

Recent advances in polymer synthesis have significantly enhanced the ability to rationally design block copolymers with tailored functionality. The self‐assembly of these macromolecules in the solid state or in solution allows the formation of nanostructured materials with a variety of properties and potential functions. This Review illustrates recent progress in the field of block copolymer materials by highlighting selected emerging applications.
Smart Self‐Assembled Hybrid Hydrogel Biomaterials
Authors: Kopeček Jindřich , Yang Jiyuan
Published: July 2012

Hybrid biomaterials are systems created from components of at least two distinct classes of molecules, for example, synthetic macromolecules and proteins or peptide domains. The synergistic combination of two types of structures may produce new materials that possess unprecedented levels of structural organization and novel properties. This Review focuses on biorecognition‐driven self‐assembly of hybrid macromolecules into functional hydrogel biomaterials. First, basic rules that govern the secondary structure of peptides are discussed, and then approaches to the specific design of hybrid systems with tailor‐made properties are evaluated, followed by a discussion on the similarity of design principles of biomaterials and macromolecular therapeutics. Finally, the future of the field is briefly outlined.
Synthesis of star–comb‐shaped polymer with porphyrin‐core and its self‐assembly behavior study
Authors: Zhang Bao , Wang Di , Li Meng , Li Yapeng , Chen Xuesi
Published: July 2012

5,10,15,20‐tetra(4‐hydroxyphenyl)porphyrin (THPP) was synthesized by the condensation of pyrrole with 4‐hydroxybenzaldehyde in the presence of solvent (propionic acid). Subsequently, the resulting THPP was converted to a tetrafunctional star‐shaped macroinitiator (porphyrin‐Br4) by esterification of it with 2‐bromopropanoyl bromide, and then atom transfer radical polymerization (ATRP) of styrene was conducted at 110°C with CuCl/2,2′‐bipyridine as the catalyst system. The resulting product was reacted with NBS to obtain star‐shaped initiator porphyrin‐(PSt‐Br)4, which was used the following ATRP of the GMA to synthesize star–comb‐shaped grafted polymer porphyrin‐(PSt‐g‐PGMA)4. The number molecular weight was 2.3 × 104 g/mol, and the dispersity was narrow (Mw/Mn = 1.32). The structure of the polymers was investigated by NMR, UV–vis, IR, and GPC measurement. The self‐assembly behavior of the polymer porphyrin‐(PSt‐g‐PGMA)4 was studied by DLS and AFM. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Incorporation of multiwalled carbon nanotube into a polymethacrylate‐based monolith for ion chromatography
Authors: Wang Nani , He Shiwei , Yan Wenwu , Zhu Yan
Published: July 2012

A new monolithic stationary phase containing multiwalled carbon nanotube (MWCNT) was prepared by in situ polymerization of methacrylate monomers in a silanized capillary. The novel stationary phases were studied by scanning electron microscopy, Raman spectroscopy, thermogravimetric analysis, Fourier Transform Infrared spectroscopy, and mechanical stability test. Application of the columns in ion chromatography (IC) separation of five inorganic anions provided satisfactory under the isocratic elution condition. It was observed that MWCNT in the monoliths played an important role in the IC separation. Both the column efficiencies and exchange capacities were improved by adding MWCNT in the monoliths. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Effect of take‐up speed on polyvinylidene fluoride hollow fiber membrane in a thermally induced phase separation process
Authors: Li Xianfeng , Liu Huiyu , Xiao Changfa , Ma Shihu , Zhao Xuehui
Published: July 2012

The porous polyvinylidene fluoride hollow fiber membranes were prepared via the thermally induced phase separation process using mixed diluent. The effects of take‐up speed on the structure of membranes were investigated by scanning electron microscopy, differential scanning calorimetry, and wide‐angle X‐ray diffraction. The membrane properties were measured in terms of the pure water flux, porosity, and mechanical properties. The results showed that the cross‐sectional structure of membrane had an obvious change and presented a uniform structure when TS increased to 72 m min−1, whereas the membrane made from TS <41 m min− presented an interconnected aggregation structure. However, the change of surface structure of all membranes was hardly observed. In addition, the strength and elongation of breakage of membrane increased obviously with the increase of TS, whereas the pure water flux and porosity changed slightly. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Synthesis and properties of P(NIPAAm‐co‐AM)/SiO2 hybrid temperature‐sensitive hydrogels
Authors: Li Yun‐Long , Ouyang Na , Ke Ai‐Ru , Lin Song‐Bai
Published: July 2012

Using N, N′‐methylene bisacrylamide as crosslinking agent and potassium peroxydisulfate as initiator, the temperature‐sensitive hydrogels were prepared with organic monomer N‐isopropylacrylamide (NIPAAm) and acrylic amide and inorganic material ethyl orthosilicate (TEOS). The structure of hybrid hydrogels was represented by scanning electron microscopy and Fourier transform infrared spectroscopy. The volume phase transition temperature (VPTT) of hybrid hydrogels was determined by differential scanning calorimetry thermograms of the swollen hydrogel. The results showed that the VPTT of the hydrogels increased with the increasing of TEOS dosage. When the temperature was lower than VPTT, the hydrogels exhibited excellent temperature sensitivity and kept at a swelling state, but when the temperature was higher than VPTT, the hydrogels deswelled significantly. In addition, the compressive strength of hydrogels was studied, the results showed that hybrid hydrogels had more ideal mechanical properties than organic hydrogels. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Hair efficacy of botanical extracts
Authors: Benaiges Aurora , Fernández Estibalitz , Martínez‐Teipel Blanca , Armengol Ricard , Barba Clara , Coderch Luisa
Published: July 2012

The great increase of capillary treatments (bleaching, perming, etc.) has created an important demand for hair cosmetics designed to repair and even prevent adverse effects on the capillary structure. In this work, the effect on hair of three botanical actives is investigated. Hair was chemically damaged by bleaching and the efficacy of three botanical actives was demonstrated by evaluation of surface morphology, differential scanning calorimetry, strength/relaxation, and absorption/desorption properties. Bleaching treatments have been demonstrated to modify the hair properties producing an increase in the fiber permeability and detrimental effects on the mechanical properties. Application of the botanical extracts to pretreated hair has improved the mechanical properties, giving rise to a reduction of the fibres' permeability, coating them and increasing the crystalline material of the fibers. Treatments with botanical actives based on either proteins and peptides, sulfated polysaccharides or a combination of polysaccharides could be used to protect and repair the hair fibers. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Synthesis, characterization, and working mechanism of a synthetic high temperature (200°C) fluid loss polymer for oil well cementing containing allyloxy‐2‐hydroxy propane sulfonic (AHPS) acid monomer
Authors: Tiemeyer Constantin , Plank Johann
Published: July 2012

A polymer comprising of 2‐acrylamido‐2‐methyl propane sulfonic acid, N, N‐dimethyl acrylamide, allyloxy‐2‐hydroxy propane sulfonic acid (AHPS), acrylic acid, and N, N‐methylene bisacrylamide was synthesized by aqueous free radical copolymerization and tested as high temperature performing fluid loss additive (FLA) in oil well cement. Successful incorporation of AHPS was confirmed and characteristic properties of the copolymer were determined using size exclusion chromatography. The FLA showed excellent water retention in cement at 200°C/70 bar. At this temperature, polymer structure changed from branched to linear and hydrodynamic size decreased by ∼50%, thus indicating potential fragmentation, while performance remained unaffected by these alterations. The FLA copolymer does not viscosify cement slurries which is advantageous in high temperature well cementing. The working mechanism of the AHPS‐based copolymer was found to rely on reduction of filtercake permeability which is caused by a voluminous coprecipitate of the FLA with tartaric acid retarder, mediated by Ca2+ ions. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Serglycin in Health and Diseases
Authors: Scully Olivia J. , Chua Pei‐Jou , Harve Karthik S. , Bay Boon‐Huat , Yip George W.
Published: July 2012

Serglycin is a multifunctional molecule and one of the first proteoglycans to be cloned. In this manuscript, we examine the physiological roles of serglycin in immunity, hemostasis, cell growth, apoptosis, and reproduction. In addition, we review recent studies on the involvement of serglycin in various pathological conditions, including cancer, inflammatory diseases, and platelet disorders. Anat Rec, 2012. © 2012 Wiley Periodicals, Inc.
High‐Performance Lithium‐Ion Anodes with Hierarchically Assembled Single‐Crystal SnO2 Nanoflake Spheres
Authors: Liu Zhaoyang , Bai Hongwei , Sun Darren Delai
Published: July 2012

A large‐scale hierarchical assembly route is reported for the formation of SnO2 on the nanoscale that contains rigid and robust spheres with irregular channels for rapid access of Li ions into the hierarchically structured interiors. Large volume changes during the process of Li insertion and extraction are accommodated by the SnO2 nanoflake spheres’ internal porosity. The hierarchical SnO2 nanoflake spheres exhibit good lithium storage properties with high capacity and long‐lasting performance when used as lithium‐ion anodes. A reversible capacity of 517 mA h g−1, still greater than the theoretical capacity of graphite (372 mA h g−1), after 50 charge–discharge cycles is attained. Meanwhile, the synthesis process is simple, inexpensive, safe, and broadly applicable, providing new avenues for the rational engineering of electrode materials with enhanced conductivity and power.
Reliable H∞ Filtering for Mixed Time‐Delay Systems with Stochastic Nonlinearities and Multiplicative Noises
Authors: Wen S. P. , Zeng Z. G. , Huang T. W.
Published: July 2012

This paper investigates the reliable H∞ filtering problem for a class of mixed time‐delay systems with stochastic nonlinearities and multiplicative noises. The mixed delays comprise both discrete time‐varying and distributed delays. The stochastic nonlinearities in the form of statistical means cover several well‐studied nonlinear functions. The multiplicative disturbances are in the form of a scalar Gaussian white noise with unit variance. Furthermore, the failures of sensors are quantified by a variable varying in a given interval. In the presence of mixed delays, stochastic nonlinearities, and multiplicative noises, sufficient conditions for the existence of a reliable H
∞ filter are derived, such that the filtering error dynamics is asymptotically mean‐square stable and also achieves a guaranteed H
∞ performance level. Then, a linear matrix inequality (LMI) approach for designing such a reliable H
∞ filter is presented. Finally, a numerical example is provided to illustrate the effectiveness of the developed theoretical results.
On a Simplified Residual Vibration Ratio Function for Input Shaping Control
Authors: Kang Chul‐Goo , Kwak Jung‐Han
Published: July 2012

In the literature of input shaping control, two kinds of residual vibration ratio function have been introduced for evaluating the robustness of input shaping control to modeling error. Also, two types of derivative constraints for the residual vibration ratio function have been used for suppressing residual vibration under the condition of having some modeling errors in natural frequency and damping ratio. In this paper, a simplified residual vibration ratio function is presented, which is more convenient to use than the conventional function, and the equivalence of two derivative constraints for the simplified residual vibration ratio function is shown mathematically. The validity of the assertion is demonstrated by means of simulation and experimental studies.
Active Heave Compensation Control of ROVS
Authors: Li Jia‐Wang , Ge Tong , Wang Xu‐Yang
Published: July 2012

To keep the remotely operated vehicles (ROVs) motion unaffected by the ship's motion in the vertical direction, a nonlinear active heave compensation controller is designed in this paper. The compensation system consists mainly of an electro‐hydraulic system driven by a double rod cylinder. Based on the external model principle, an adaptive observer is proposed to asymptotically estimate the ship's heave motion represented by a set of sinusoidal signals. The hybrid control development and stability analysis are based on the Lyapunov's direct method and backstepping technique. The proposed controller forces the tracking error to globally asymptotically converge to a small zone around zero that can be reduced arbitrarily. Simulation results illustrate and validate the effectiveness of the proposed control scheme.
Quantum chemistry: Large molecules — small computers
Authors: Ahlrichs Reinhart , Elliott Simon D. , Huniar Uwe
Published: July 2012

Some aspects of the current state of Quantum Chemistry are presented, along with a selection of results for large molecules using modest resources. Following a brief exposition of the fundamental approximations of ab initio calculations, the SCF, DFT and MP2 methods for calculating molecular wavefunctions and energies are introduced. The Resolution of Identity (RI) approach is described with a view to the treatment of large molecules (100 atoms and more). Scaling behavior of the various computational methods is compared; here, aluminium clusters represent a demanding application. The utility of analytical energy gradients is shown, in particular using the example of a theoretical study of the structural isomers of sulfur‐bridged copper clusters. A strategy to compute electronic excitation energies for large molecules is sketched and applications to fullerenes and cadmium‐selenide nanoclusters are presented. Developments in scientific computing hardware are considered, with emphasis on the emergence of PC's. The opportunities and difficulties inherent in the parallelization of quantum chemical code are also discussed, and the performance of parallel TURBOMOLE is presented.
Electroreduction of 1,4‐benzoquinone and cobaltocenium perchlorate on the oxidized electroinactive polyaniline films in acetonitrile
Authors: Pekmez Nuran , Yildiz Attila
Published: July 2012

Electroactivity losses of polyaniline films which result after the anodic oxidation and the oxidation by the protonated form of superoxide anion radical, HO2•, were compared. It is shown that overoxidized polyaniline films behave differently depending on the method of overoxidizing in acetonitrile. The reduction of 1,4‐benzoquinone and cobaltocenium perchlorate on the anodically oxidized film revealed that the film does not behave as an insulator and takes part in the electron transfer process. The film which is chemically oxidized by the protonated form of superoxide anion radical is not involved in the charge transfer and the electroreduction occurs on the underlying Pt surface which becomes available for electron transfer as a result of the formation of the pores during the chemical oxidation.
The all‐or‐none phenomenon revisited
Authors: Adam Margaret P.
Published: July 2012

One of the more pervasive tenets of teratology is the “all‐or‐none” phenomenon, which refers to the concept that embryonic exposure that occurs before organogenesis results in either no adverse embryonic outcome or in embryonic death. This concept has been used extensively in genetic counseling of pregnant women who have inadvertently undergone an exposure in the very early stages of pregnancy, frequently before the pregnancy has been recognized. Herein, we review the data that supports the all‐or‐none concept and the exceptions to this general rule. In the absence of further human evidence to the contrary, and given the many women exposed to medications or environmental agents before learning of their pregnancies, it would be prudent to continue to counsel pregnant women using the all‐or‐none hypothesis to avoid needless interruption of pregnancy out of unfounded fear of an adverse pregnancy outcome. Birth Defects Research (Part A) 94:664–669, 2012. © 2012 Wiley Periodicals, Inc.
Transcriptome profiling of genes involved in neural tube closure during human embryonic development using long serial analysis of gene expression (long‐SAGE)
Authors: Krupp Deidre R. , Xu Pu‐Ting , Thomas Sophie , Dellinger Andrew , Etchevers Heather C. , Vekemans Michel , Gilbert John R. , Speer Marcy C. , Ashley‐Koch Allison E. , Gregory Simon G.
Published: July 2012

BACKGROUND

Neural tube defects (NTDs) are common human birth defects with a complex etiology. To develop a comprehensive knowledge of the genes expressed during normal neurulation, we established transcriptomes from human neural tube fragments during and after neurulation using long Serial Analysis of Gene Expression (long‐SAGE).

METHODS

Rostral and caudal neural tubes were dissected from normal human embryos aged between 26 and 32 days of gestation. Tissues from the same region and Carnegie stage were pooled (n ≥ 4) and total RNA extracted to construct four long‐SAGE libraries. Tags were mapped using the UniGene Homo sapiens 17 bp tag‐to‐gene best mapping set. Differentially expressed genes were identified by chi‐square or Fisher's exact test, and validation was performed for a subset of those transcripts using in situ hybridization. In silico analyses were performed with BinGO and EXPANDER.

RESULTS

We observed most genes to be similarly regulated in rostral and caudal regions, but expression profiles differed during and after closure. In silico analysis found similar enrichments in both regions for biologic process terms, transcription factor binding and miRNA target motifs. Twelve genes potentially expressing alternate isoforms by region or developmental stage, and the microRNAs miR‐339‐5p, miR‐141/200a, miR‐23ab, and miR‐129/129‐5p are among several potential candidates identified here for future research.

CONCLUSIONS

Time appears to influence gene expression in the developing central nervous system more than location. These data provide a novel complement to traditional strategies of identifying genes associated with human NTDs and offer unique insight into the genes associated with normal human neurulation. Birth Defects Research (Part A) 94:683–692, 2012. © 2012 Wiley Periodicals, Inc.
Trihydroxyflavones with antioxidant and anti‐inflammatory efficacy
Authors: Gomes Ana , Couto Diana , Alves Andreia , Dias Irene , Freitas Marisa , Porto Graça , Duarte José Alberto , Fernandes Eduarda
Published: July 2012

The classical anti‐inflammatory therapies are frequently ineffective and present numerous and severe side effects, especially in long term use, which requires the development of anti‐inflammatory drugs with different scaffolds and mechanisms of action. Owing to the high antioxidant potential and anti‐inflammatory activities already inferred for hydroxyflavones, we found it would be relevant to evaluate the anti‐inflammatory potential of a series of trihydroxyflavones by testing their ability to scavenge reactive oxygen species (ROS) and reactive nitrogen species (RNS) in cells and cell‐free systems and to inhibit the proinflammatory pathways mediated by the enzymes cyclooxygenase (COX) and 5‐lipoxygenase (5‐LOX), in which reactive species have a proven involvement. The tested trihydroxyflavones proved to be effective inhibitors of neutrophils' oxidative burst and were shown to scavenge different ROS and RNS in cell‐free systems. The most active compound in the majority of the assays was 3,3′,4′‐trihydroxyflavone, which was somehow expected due to the presence of the ortho‐dihydroxy in the B‐ring, an important structural feature in terms of free radical scavenging activity. Additionally, the studied compounds were able to inhibit the production of leukotriene B4 by 5‐LOX in activated neutrophils. 3,5,7‐Trihydroxyflavone was able to inhibit both COX‐1 and COX‐2, which makes it a dual inhibitor of COX and 5‐LOX pathways and, therefore, a promising candidate for a new therapeutic option in the treatment of inflammatory processes.
The hypotriglyceridemic effect of biotin supplementation involves increased levels of cGMP and AMPK activation
Authors: Aguilera‐Méndez Asdrúbal , Fernández‐Mejía Cristina
Published: July 2012

In addition to its role as a carboxylase cofactor, biotin modifies gene expression and has manifold effects on systemic processes. Several studies have shown that biotin supplementation reduces hypertriglyceridemia. We have previously reported that this effect is related to decreased expression of lipogenic genes. In the present work, we analyzed signaling pathways and posttranscriptional mechanisms involved in the hypotriglyceridemic effects of biotin. Male BALB/cAnN Hsd mice were fed a control or a biotin‐supplemented diet (1.76 or 97.7 mg of free biotin/kg diet, respectively for 8 weeks after weaning. The abundance of mature sterol regulatory element‐binding protein (SREBP‐1c), fatty‐acid synthase (FAS), total acetyl‐CoA carboxylase‐1 (ACC‐1) and its phosphorylated form, and AMP‐activated protein kinase (AMPK) were evaluated in the liver. We also determined the serum triglyceride concentrations and the hepatic levels of triglycerides and cyclic GMP (cGMP). Compared to the control group, biotin‐supplemented mice had lower serum and hepatic triglyceride concentrations. Biotin supplementation increased the levels of cGMP and the phosphorylated forms of AMPK and ACC‐1 and decreased the abundance of the mature form of SREBP‐1c and FAS. These data provide evidence that the mechanisms by which biotin supplementation reduces lipogenesis involve increased cGMP content and AMPK activation. In turn, these changes lead to augmented ACC‐1 phosphorylation and decreased expression of both the mature form of SREBP‐1c and FAS. Our results demonstrate for the first time that AMPK is involved in the effects of biotin supplementation and offer new insights into the mechanisms of biotin‐mediated hypotriglyceridemic effects.
Anionic complexes of MWCNT with supergiant cyanobacterial polyanions
Authors: Okajima Maiko K. , Kumar Amit , Fujiwara Akihiko , Mitsumata Tetsu , Kaneko Daisaku , Ogawa Tetsuya , Kurata Hiroki , Isoda Seiji , Kaneko Tatsuo
Published: July 2012

Multi‐walled carbon nanotubes (MWCNTs) were well dispersed in an aqueous solution of the cyanobacterial polysaccharide, sacran, with an ultra‐high molecular weight >10 million g/mol. MWCNTs powder was put into aqueous solutions of various polysaccharides including sacran and was dispersed under sonication. As a result of the turbidity measurement of the supernatant, it was found that sacran showed the highest MWCNT‐dispersion efficiency of all the polysaccharides used here. Cryogenic transmission electron microscopic (Cryo‐TEM) studies directly demonstrated the existence of MWCNTs in the supernatant, and high‐resolution TEM observation revealed that MWCNTs covered by sacran chains made their efficient dispersion in water. Raman spectroscopy demonstrated the existence of MWCNT in dried sample from supernatant and the interaction between MWCNT and sacran. The ζ‐potential measurement of the dispersion indicated the negative surface charges of the sacran/MWCNT complexes. Then the MWCNT complexes were able to fabricate by ionic interaction; electrophoresis of the anionic complex formed the sacran/MWCNT gels on the anode while the droplet of sacran/MWCNT dispersion formed gel beads in the presence of the lanthanoid cations. © 2012 Wiley Periodicals, Inc.
The association between cingulate cortex glutamate concentration and delay discounting is mediated by resting state functional connectivity
Authors: Schmaal Lianne , Goudriaan Anna E. , van der Meer Johan , van den Brink Wim , Veltman Dick J.
Published: July 2012

Humans vary in their ability to delay gratification and impulsive decision making is a common feature in various psychiatric disorders. The level of delay discounting is a relatively stable psychological trait, and therefore neural processes implicated in delay discounting are likely to be based on the overall functional organization of the brain (under task‐free conditions) in which state‐dependent shifts from baseline levels occur. The current study investigated whether delay discounting can be predicted by intrinsic properties of brain functioning. Fourteen healthy male subjects performed a delay discounting task. In addition, resting state functional magnetic resonance imaging (fMRI) and magnetic resonance spectroscopy (¹H MRS) were used to investigate the relationship between individual differences in delay discounting and molecular and regional measures of resting state (baseline) activity of dorsal anterior cingulate cortex (dACC). Results showed that delay discounting was associated with both dACC glutamate concentrations and resting state functional connectivity of the dACC with a midbrain region including ventral tegmental area and substantia nigra. In addition, a neural pathway was established, showing that the effect of glutamate concentrations in the dACC on delay discounting is mediated by functional connectivity of the dACC with the midbrain. The current findings are important to acknowledge because spontaneous intrinsic brain processes have been proposed to be a potential promising biomarker of disease and impulsive decision making is associated with several psychiatric disorders.