bluuebunny/crossref_metadata_2025 huggingface dataset:
La démographie de l'Asie de l'Est et du Sud-Est des années 1950 aux années 2000
Authors: Attané Isabelle , Barbieri Magali
Published: October 2011

Résumé Avec ses 2,1 milliards d’habitants, l’Asie de l’Est et du Sud-Est rassemble le tiers de la population mondiale, notamment du fait de la présence de la Chine, pays le plus peuplé du monde, qui compte à elle seule 1,3 milliard d’habitants. Cette chronique propose à la fois une synthèse des grandes évolutions sociodémographiques et sanitaires depuis les années 1950 et un bilan statistique rassemblant les données récentes les plus fiables sur chaque pays. Y sont notamment examinés les effectifs et les structures de la population, la fécondité et ses variables intermédiaires, la nuptialité, la mortalité et la santé, les migrations internationales, l’urbanisation et l’accès à l’éducation. La région se distingue particulièrement par des progrès extraordinairement rapides réalisés tant dans le domaine de la lutte contre la mortalité que dans celui de la maîtrise de la fécondité. L’espérance de vie à la naissance est ainsi passée de 40 à 70 ans depuis le début des années 1950 et, grâce à des programmes de planification familiale souvent très interventionnistes mis en œuvre dans quelques pays, la fécondité est aujourd’hui, dans l’ensemble de la région, inférieure au seuil de remplacement des générations. Cette évolution conduit à de nouveaux défis démographiques dont les plus immédiats sont le vieillissement de la population, la réorientation des flux migratoires et, dans certains pays, un déséquilibre de la structure par sexe lié au recours massif aux avortements sélectifs.
L'État et la difficile saisie statistique de la religion : l'exemple des protestants dans les recensements en France au XIXe siècle
Authors: Dargent Claude
Published: October 2011

Résumé L’exemple des protestants montre qu’il faut prendre les données religieuses produites par les quatre recensements de 1851 à 1872 en France avec beaucoup de précautions. Curieusement, en 1851, la répartition départementale des cultes n’est pas publiée, en raison de « considérations d’une nature particulière » non explicitées. La question sur la religion est ensuite retirée du recensement de 1856 pour réapparaître en 1861 : les rédacteurs se réjouissent alors de la disparition des difficultés « assez graves » rencontrées en 1851. La stabilité du dénombrement de la population réformée telle qu’elle est publiée, les écarts entre le recensement de la population protestante urbaine en 1851 et les chiffres des sources locales, sa très forte croissance sur la période suivante et le fait que la population des réformés annoncée pour ce recensement corresponde exactement au plancher justifiant le nombre de pasteurs rémunérés par l’État en vertu du Concordat font naître une hypothèse : celle d’une importante sous-déclaration des protestants. L’État aurait alors réévalué le nombre obtenu en 1851 de façon à éviter les problèmes politico-religieux qui risquaient de se poser. On assisterait ensuite à un recul de la sous-déclaration à partir de 1861, décalé de quelques années pour Paris.
Évolution du recours à l'interruption volontaire de grossesse en France entre 1990 et 2005
Authors: Rossier Clémentine , Toulemon Laurent , Prioux France
Published: October 2011

Résumé La loi autorisant l’avortement depuis 1975 en France a été modifiée en 2001 dans le but de faciliter l’accès des femmes aux services d’interruption volontaire de grossesse (IVG), en particulier par l’augmentation de deux semaines de la durée de gestation maximale autorisée. Les données provenant des bulletins d’IVG permettent d’étudier l’impact de ces modifications législatives, en utilisant la durée de gestation au moment de l’IVG comme indicateur des difficultés d’accès à ce service. Par ailleurs, la loi autorise la contraception médicalisée depuis 1967 en France ; la diminution des grossesses non prévues et des IVG jusqu’au milieu des années 1990 est attribuable au succès de la diffusion de ces méthodes dans les années 1970 et 1980. Le recours à l’avortement reste cependant élevé en France par rapport aux autres pays d’Europe de l’Ouest. Cela pose la question de la persistance ou de la recrudescence des grossesses non prévues chez les femmes les plus jeunes et celle du recours répété à l’avortement au cours de la vie de certaines femmes.
Homosexualité et bisexualité au Sénégal : une réalité multiforme
Authors: Larmarange Joseph , Desgrées du Loû Annabel , Enel Catherine , Wade Abdoulaye
Published: October 2011

Résumé Les premières enquêtes menées au Sénégal auprès d’hommes ayant des rapports sexuels avec d’autres hommes, dans le cadre de la lutte contre le sida, révèlent des taux élevés de bisexualité. En 2007, une nouvelle enquête épidémiologique et comportementale (ELIHoS) a été réalisée, dans laquelle la question des pratiques bisexuelles a été abordée de façon approfondie. Cette enquête est utilisée ici pour décrire la pluralité de formes que peut recouvrir la bisexualité au Sénégal. Une typologie du pôle d’activité sexuelle actuel en six classes est construite à partir des caractéristiques des partenaires sexuels sur l’année et au moment de l’enquête. Différents éléments de la sociobiographie sexuelle des individus sont ensuite analysés selon leur pôle d’activité sexuelle actuel. Il apparaît que ces pôles correspondent à des pratiques sexuelles et à des caractéristiques différentes d’entrée en vie sexuelle avec un homme. En revanche, l’utilisation systématique d’un préservatif, à pratiques égales, ne dépend pas du pôle d’activité sexuelle. Les hommes engagés dans des relations régulières avec des femmes et ayant des partenaires masculins seulement occasionnellement sont moins souvent infectés par le VIH, car ils ont moins fréquemment des rapports anaux à risque.
Instruction des femmes et évolution du mariage en Inde
Authors: Dommaraju Premchand
Published: October 2011

Résumé Cet article examine l’influence de l’éducation sur la nuptialité des femmes en Inde, par l’analyse des données longitudinales extraites des recensements. Entre 1981 et 2001, les niveaux d’instruction et l’âge au mariage ont tous deux augmenté. Si les données transversales montrent une association positive entre le niveau de scolarisation et le report du mariage, la modélisation des données longitudinales indique que l’impact de l’instruction sur le calendrier du mariage est assez limité, surtout pendant la période 1981-1991 ; il est néanmoins significatif, bien que modeste, entre 1991 et 2001. Selon les résultats de cette étude, l’association entre éducation et nuptialité mise en évidence par l’analyse des données transversales pourrait être due à des facteurs non observés qui influencent à la fois la scolarisation et le mariage. En fait, l’évolution à long terme de l’âge au mariage a un effet plus déterminant que celle du niveau d’instruction sur la nuptialité des femmes avant 20 ans. Et la modélisation avec variables instrumentales indique que l’éducation et la nuptialité ne sont pas interdépendantes : les progrès des niveaux de scolarisation sont largement indépendants de l’évolution de l’âge au mariage.
L'impact de la loi de 1862 généralisant la responsabilité limitée au secteur bancaire et financier sur la crise anglaise de 1866
Authors: Foucaud David
Published: October 2011

Résumé La crise anglaise de 1866 conserve encore une part de mystère, tant au niveau de ses causes que de ses effets. On s’explique mal pourquoi elle ne toucha que l’Angleterre alors que les autres pays ne furent jamais atteints. Le principal effet de la crise, une défiance généralisée de la part de tous les pays européens vis-à-vis de l’Angleterre, se comprend également difficilement. La thèse soutenue dans cet article est que la crise de 1866 a comme cause la déréglementation générale de 1862 étendant le principe de responsabilité limitée à toutes les entreprises anglaises. Cette loi modifia en profondeur le comportement des entrepreneurs, ce qui conduisit à faire apparaître un risque systémique dans le secteur bancaire. De cette manière, on peut expliquer la non-contagion de la crise et la méfiance des investisseurs étrangers.
Les comportements d'emprunt des régions françaises
Authors: Dufrénot Gilles , Frouté Philippe , Schalck Christophe
Published: October 2011

Résumé Cet article montre qu’en dépit de contraintes comptables communes les obligeant à équilibrer leur budget et à emprunter uniquement pour financer l’investissement (règle d’or), les comportements d’emprunt des régions françaises sont hétérogènes. Ce résultat est établi par des régressions quantiles. L’hétérogénéité est très prononcée lorsque les régions subissent un choc d’endettement négatif, durcissement des conditions financières par exemple. Ceci pourrait résulter du fait que la règle d’or soit considérée comme une «  soft rule  » par des collectivités anticipant un sauvetage financier automatique de la part du gouvernement. Ainsi, dans le cas français, la plausibilité de l’hypothèse de bailing-out n’est pas invalidée.
Erythroblast Enucleation
Authors: Keerthivasan Ganesan , Wickrema Amittha , Crispino John D.
Published: October 2011

Even though the production of orthochromatic erythroblasts can be scaled up to fulfill clinical requirements, enucleation remains one of the critical rate-limiting steps in the production of transfusable red blood cells. Mammalian erythrocytes extrude their nucleus prior to entering circulation, likely to impart flexibility and improve the ability to traverse through capillaries that are half the size of erythrocytes. Recently, there have been many advances in our understanding of the mechanisms underlying mammalian erythrocyte enucleation. This review summarizes these advances, discusses the possible future directions in the field, and evaluates the prospects for improved ex vivo production of red blood cells.
Optimization of Adjuvant Radiation in Breast Conservation Therapy: Can We Minimize without Compromise?
Authors: Edwards-Bennett Sophia M. , Correa Candace R. , Harris Eleanor E.
Published: October 2011

Adjuvant breast radiation therapy after breast conservation surgery is recommended as it yields significant reduction in the risk of local recurrence, and confers a potential overall survival benefit. Although the standard breast radiation regimen has historically been delivered over 5–7 weeks; more novel, shorter courses of breast radiation are currently being employed, offering the advantage of more convenience and less time-commitment. Herein, we review the recent literature substantiating these abbreviated radiation treatment approaches and the methods of delivery thereof. In addition, we discuss imaged guided techniques currently being utilized to further refine the delivery of adjuvant breast radiation therapy.
Tumor Suppressors and Cell-Cycle Proteins in Lung Cancer
Authors: Baldi Alfonso , De Luca Antonio , Esposito Vincenzo , Campioni Mara , Spugnini Enrico P. , Citro Gennaro
Published: October 2011

The cell cycle is the cascade of events that allows a growing cell to duplicate all its components and split into two daughter cells. Cell cycle progression is mediated by the activation of a highly conserved family of protein kinases, the cyclin-dependent kinases (CDKs). CDKs are also regulated by related proteins called cdk inhibitors grouped into two families: the INK4 inhibitors (p16, p15, p19, and p18) and the Cip/Kip inhibitors (p21, p27, and p53). Several studies report the importance of cell-cycle proteins in the pathogenesis and the prognosis of lung cancer. This paper will review the most recent data from the literature about the regulation of cell cycle. Finally, based essentially on the data generated in our laboratory, the expression, the diagnostic, and prognostic significance of cell-cycle molecules in lung cancer will be examined.
Obeying God? Obeying Paul? Bridging the socio-cultural context in the interpretation of Biblical imperatives
Authors: Van Rheede van Oudtshoorn Andre
Published: October 2011

When do we encounter God in the Pauline imperatives, or when is it Paul, the man of his times, that we are dealing with? This article develops a model to help us determine the reach of the imperatives into our socio-cultural context today. The imperatives are shown to be more than ad hoc injunctions but, rather, legitimate expressions of the new symbolic world in which both Paul and believers participate by faith. The imperatives carry an illocutionary force which relies on such a shared symbolic world. By analysing Paul�s imperatives in terms of this symbolic world it is clear that he, at times, simply accepted the dominant cultural interpretation of reality of his day at the cost of limiting the expression of his symbolic world. At other times he modified the dominant cultural interpretation by calling believers to act contra-culturally in the light of the gospel�s new interpretation of reality. There are also instances where Paul directly rejects certain aspects of the culture of the day in the light of the symbolic world. Paul�s flexibility to develop a variety of responses towards the dominant culture of his day in the light of the indicatives of the gospel message provides an important key to developing a model to determine �if?�, �when?� and �how?�, to apply the imperatives into our context today.
Description of a Prospective 17DD Yellow Fever Vaccine Cohort in Recife, Brazil
Authors: de Melo Andréa Barbosa , da Silva Maria da Paz C. , Magalhães Maria Cecília F. , Gonzales Gil Laura Helena Vega , Freese de Carvalho Eduardo M. , Braga-Neto Ulisses M. , Bertani Giovani Rota , Marques Ernesto T. A. , Cordeiro Marli Tenório
Published: October 2011

From September 2005 to March 2007, 238 individuals being vaccinated for the first time with the yellow fever (YF) -17DD vaccine were enrolled in a cohort established in Recife, Brazil. A prospective study indicated that, after immunization, anti-YF immunoglobulin M (IgM) and anti-YF IgG were present in 70.6% (IgM) and 98.3% (IgG) of the vaccinated subjects. All vaccinees developed protective immunity, which was detected by the plaque reduction neutralization test (PRNT) with a geometric mean titer of 892. Of the 238 individuals, 86.6% had IgG antibodies to dengue virus; however, the presence of anti-dengue IgG did not interfere significantly with the development of anti-YF neutralizing antibodies. In a separate retrospective study of individuals immunized with the 17DD vaccine, the PRNT values at 5 and 10 years post-vaccination remained positive but showed a significant decrease in neutralization titer (25% with PRNT titers < 100 after 5 years and 35% after 10 years).
Aggregate Evaluable Organ Dysfunction Predicts In-Hospital Mortality from Sepsis in Uganda
Authors: Ssekitoleko Richard , Pinkerton Relana , Muhindo Rose , Bhagani Sanjay , Moore Christopher C.
Published: October 2011

We evaluated the association between severity of sepsis and in-hospital mortality in 150 patients with non-surgical sepsis at a regional referral hospital in Uganda. In-hospital mortality occurred in 5 of 52 (9.6%) patients with sepsis, 24 of 71 (33.8%) patients with severe sepsis, and 16 of 27 (59.3%) patients with septic shock. In the multivariate analysis, the identification of severe sepsis (adjusted hazard ratio [AHR] = 2.9, 95% confidence interval [CI] = 1.0–8.2, P = 0.04), septic shock (AHR = 5.7, 95% CI = 1.6–20.3, P = 0.007), and dysfunction of three or more organs (AHR = 2.9, 95% CI = 1.1–7.3, P = 0.03) increased the risk of in-hospital mortality. Adding aggregate organ dysfunction to the multivariate equation that included the sepsis category statistically significantly improved the model, but the opposite did not. Predictors of mortality were easily measurable and could be used to risk stratify critically ill patients in resource-constrained settings.
Vernal Keratoconjunctivitis in School Children in Rwanda and Its Association with Socio-Economic Status: A Population-Based Survey
Authors: Smedt Stefan De , Nkurikiye John , Fonteyne Yannick , Hogewoning Arjan , Esbroeck Marjan Van , Bacquer Dirk De , Tuft Stephen , Gilbert Clare , Delanghe Joris , Kestelyn Philippe
Published: October 2011

Vernal keratoconjunctivitis (VKC) is an allergic eye disease and an important cause of hospital referral among children in Africa and Asia. Hospital-based studies have suggested a role for parasites in its pathogenesis. To determine the prevalence and risk factors for VKC in Central Africa, we conducted a nested population-based case control study in Rwanda, involving randomly selected primary schools from different environments (rural/urban) and climate. A prevalence of VKC of 4.0% (95% confidence interval 3.3–4.7%) was found among 3,041 children studied (participation rate 94.7%). The intestinal parasitic burden was not related to VKC. Besides hot dry climate (odds ratio [OR] = 1.5, P = 0.05) and male gender (OR = 1.7, P = 0.005), multivariate analysis identified higher economic status as a risk for VKC (OR = 1.4, P = 0.005). The effect on VKC of higher economic status appears not to act through differences in parasitic intestinal load.
Malaria in Africa Can Be Eliminated
Authors: Campbell Carlos C. , Steketee Richard W.
Published: October 2011

A concerted effort to control malaria in Africa has produced dramatic reductions in childhood death in the past decade. This early success has prompted the global community to commit to eradication of malaria deaths and eventually all transmission. Evidence suggests that this is a feasible goal using currently available interventions, augmented with newer tools such as vaccines, which are in development. Malaria deaths are entirely preventable now, and our sustained political and financial commitment to continue to prevent these deaths hangs in the balance.
Three-dimensional spatial structures of solar wind turbulence from 10 000-km to 100-km scales
Authors: Narita Y. , Glassmeier K.-H. , Goldstein M. L. , Motschmann U. , Sahraoui F.
Published: October 2011

Abstract. Using the four Cluster spacecraft, we have determined the three-dimensional wave-vector spectra of fluctuating magnetic fields in the solar wind. Three different solar wind intervals of Cluster data are investigated for this purpose, representing three different spatial scales: 10 000 km, 1000 km, and 100 km. The spectra are determined using the wave telescope technique (k-filtering technique) without assuming the validity of Taylor's frozen-in-flow hypothesis nor are any assumptions made as to the symmetry properties of the fluctuations. We find that the spectra are anisotropic on all the three scales and the power is extended primarily in the directions perpendicular to the mean magnetic field, as might be expected of two-dimensional turbulence, however, the analyzed fluctuations are not axisymmetric. The lack of axisymmetry invalidates some earlier techniques using single spacecraft observations that were used to estimate the percentage of magnetic energy residing in quasi-two-dimensional power. However, the dominance of two-dimensional turbulence is consistent with the relatively long mean free paths of cosmic rays in observed in the heliosphere. On the other hand, the spectra also exhibit secondary extended structures oblique from the mean magnetic field direction. We discuss possible origins of anisotropy and asymmetry of solar wind turbulence spectra.
A Web-Based Geotechnical GIS
Authors: Graettinger Andrew J. , Ryals Zachary T. , Smith Randy K.
Published: October 2011

A web-based Geotechnical Geographic Information System (GeoGIS) was developed and tested for the Alabama Department of Transportation. This web-based system stores geotechnical information about transportation projects, such as subsurface data, construction drawings, and design information. Typically, this information is in a report or plan sheet format, but raw geotechnical data can also be accommodated in the GeoGIS. The goal of this system is to provide easy access and storage for all geotechnical and subsurface structural information from across a state. Access through a secure web interface allows for keyword searches and interactive map selection. The web-based GeoGIS has four geotechnical layers (project, bridge, foundation, and soil boring) that can be displayed on a road map, aerial photos, or USGS 7.5 minute quadrangles. For testing purposes the GeoGIS was populated with multiple document types, formats, and sizes. In all cases, the system performed above expectations.
Some Properties of the Complement of the Zero-Divisor Graph of a Commutative Ring
Authors: Visweswaran S.
Published: October 2011

Let R be a commutative ring with identity admitting at least two nonzero zero-divisors. Let denote the complement of the zero-divisor graph of . It is shown that if is connected, then its radius is equal to 2 and we also determine the center of . It is proved that if is connected, then its girth is equal to 3, and we also discuss about its girth in the case when is not connected. We discuss about the cliques in .
Kinetics of Vapour Diffusion and Condensation in Natural Porous Cellulosic Fibre Web
Authors: Cešek Bretislav , Milichovský Miloslav , Potucek František
Published: October 2011

Vapour diffusion in a porous web material followed by its absorption or condensation is a typical process for all porous materials particularly on polymeric and natural basis. The description of kinetic weight increment increase during this process was proposed by use of a relatively simple function with adequately defined theoretical background. It was shown that this kinetic process is controlled by vapour diffusion through porous web material. This tool in connection with observations at different air relative humidity and with use of relatively simple technique enables one to evaluate the structure properties and its structure homogeneity, that is, the uniformity character of the porous stratified web material. Utilization of this description was demonstrated during moistening kinetics of paper web of different composition from primary and secondary fibres on lignocellulosic and only cellulosic basis with different ash content.
Gastrointestinal Stromal Tumor: Advances in Diagnosis and Management
Authors: Patil Deepa T , Rubin Brian P
Published: October 2011

Context.—Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract and should be differentiated from other mesenchymal tumors. They harbor specific activating mutations in the KIT or platelet-derived growth factor receptor α (PDGFRA) receptor tyrosine kinases, which makes them responsive to pharmacologic inhibitors, such as imatinib mesylate and sunitinib malate.

Objectives.—To provide a comprehensive review of the pathogenesis of GIST and the underlying principles of targeted therapy, to review the salient histologic and immunohistochemical features that facilitate the distinction of GIST from other mesenchymal neoplasms of the gastrointestinal tract, and to present the prognostic parameters for risk stratification that guide clinical management.

Data Sources.—Review of the English literature through PubMed as well as personal experience. Photographs were taken from cases encountered at the Cleveland Clinic.

Conclusions.—The discovery of the KIT-GIST connection has not only improved the diagnostic accuracy of GISTs but also provided us with a better understanding of the histogenesis and molecular pathogenesis of these neoplasms.
Mucinous Neoplasms of the Appendix and Peritoneum
Authors: Panarelli Nicole C , Yantiss Rhonda K
Published: October 2011

Context.—Appendiceal mucinous neoplasms are considered enigmatic tumors of unpredictable biologic potential. Their importance lies in their potential to spread to the peritoneum and viscera in the form of gelatinous mucin deposits. Extra-appendiceal spread of these tumors is the most common etiology of pseudomyxoma peritonei, which is a descriptive term encompassing a number of neoplastic and nonneoplastic peritoneal disorders. Many studies aimed at evaluating the biologic importance of appendiceal mucinous neoplasms and pseudomyxoma peritonei have employed inconsistent histologic criteria for their diagnosis and descriptive terminology for their classification. As a result, appendiceal mucinous neoplasms and associated peritoneal disease represents one of the most confusing and controversial areas in gastrointestinal pathology.

Objectives.—To summarize the literature regarding the biologic potential of appendiceal mucinous neoplasms and pseudomyxoma peritonei and to discuss the similarities and differences between proposed systems for their classification.

Data Sources.—Literature review and case-derived material.

Conclusions.—Many studies have contributed to an increased understanding of the natural progression of mucinous neoplasms of the appendix and peritoneum, and the adoption of a uniform reporting system, as advocated by the American Joint Committee on Cancer and the World Health Organization, will facilitate clear communication among pathologists and clinical colleagues.
Epidermal Growth Factor Receptor Pathway Mutations and Colorectal Cancer Therapy
Authors: Grossmann Allie H , Samowitz Wade S
Published: October 2011

Context.—Rational anticancer therapy is beginning to expand the practice of surgical pathology beyond a primarily morphologic and immunophenotypic analysis into the molecular arena. Molecular testing of tumors can have both diagnostic and therapeutic value, which guides treatment decisions. This is true for colorectal cancer in which mutations in signaling mediators predict resistance to anti–epidermal growth factor receptor (anti-EGFR) therapy.

Objective.—To review the clinically relevant mutations that currently guide treatment decisions in metastatic colorectal cancer, summarize additional mutations that are expected to improve the prognostic sensitivity of molecular testing, and provide practical suggestions for submitting specimens for molecular analysis.

Data Sources.—Peer-reviewed literature reporting pertinent clinical trial data, mutation analysis, and molecular mechanisms of drug resistance, as well as comprehensive review articles germane to the topic and published testing recommendations from the College of American Pathologists.

Conclusions.—Molecular analysis of colorectal cancer is now mandated before initiation of anti-EGFR therapy and directly impacts treatment options and outcomes. Familiarity with the mutations that determine utility and efficacy of therapy, as well as the importance of careful sample selection, will facilitate appropriate testing and optimize patient care.
Mechanical, moisture absorption, and photodegradation behaviors of bacterial cellulose nanofiber‐ reinforced unsaturated polyester composites
Authors: Gao Chuan , Wan Yizao , He Fang , Liang Hui , Luo Honglin , Han Jing
Published: October 2011

Bacterial cellulose (BC) fiber reinforced unsaturated polyester (UPE) composites were fabricated using the resin transfer molding method. The mechanical properties, moisture absorption behavior, and photodegradation of the composites were studied. Scanning electron microscopy observations indicated that BC nanofibers surface‐treated with silane exhibited higher fiber–resin adhesion strength in comparison to original BC. It was noted that the process of moisture absorption of the BC/UPE composites could be described by using Fick's law and an oxidative degradation took place when the composite is exposed to ultraviolet radiation. © 2011 Wiley Periodicals, Inc. Adv Polym Techn 30: 249–256, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.20220
Preparation of latexes based on amine‐modified acrylic nanoparticles via seeded emulsion and miniemulsion polymerization
Authors: Mahdavian Ali Reza , Jeddi Yasaman Gholamzadeh , Salehi‐Mobarakeh Hamid
Published: October 2011

Seeded emulsion and miniemulsion polymerization techniques were applied to prepare latexes based on poly(methyl methacrylate‐co‐butyl acrylate) nanoparticles with potential fast‐drying properties due to the presence of chemically bound amino groups on the surface of particles. Several samples with different Tgs were produced, and the corresponding physical and mechanical properties were compared. Acrylic acid and dimethylaminoethyl methacrylate were used in the composition of the polymeric shells to provide electrosteric stability and inducing fast‐drying property, respectively. Dynamic light scattering (DLS) analysis revealed that average particles size from miniemulsion polymerization was 145 nm and more narrow in size distribution with respect to the emulsion ones with 85 nm in size. Scanning electron microscope micrographs confirmed the results of DLS analysis too. Dynamic mechanical thermal analysis thermograms showed a good correspondence of theoretical and experimental Tgs. Determination of tensile strength and hardness revealed that the polymeric film with Tg of 35°C from emulsion polymerization could be an appropriate alternative as waterborne binders. Gel permeation chromatography analysis was also used for characterization of the produced latexes. © 2011 Wiley Periodicals, Inc. Adv Polym Techn 30: 276–285, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.20223
Effect of gamma‐irradiation on the physicomechanical properties of synthetic rubber–based silica composites
Authors: Mohamed Rasha M. , Khattab Magdy M. , Abdel‐Aziz Mohamed M.
Published: October 2011

Rice husk ash (RHA) and silica‐filled nitrile rubber (NBR) composites were prepared using a laboratory‐size two‐roll mill. The mechanical properties and water absorption were studied before and after being exposed to gamma irradiation from 25 to 200 kGy. The tensile strength increased with RHA up to an optimum filler loading (20 phr) and (30 phr) for a silica‐filled NBR composite. The tensile strength for the irradiated composite filled with 30 phr silica increases with an increase in irradiation doses up to 100 kGy. The presence of silica filler phase that has a higher electron density than the polymer matrix will likely result in an increase in cross‐linking or scissioning and better dispersion in the matrix. Water absorption studies indicate that the irradiated NBR composite filled with silica has lower water absorption rather than the composite filled with RHA. © 2011 Wiley Periodicals, Inc. Adv Polym Techn 30: 301–311, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.20225
Microstructure and fracture behavior of maleated high‐density polyethylene/ silicon carbide nanocomposites toughened with poly(styrene‐ethylene‐butylene‐styrene) triblock copolymer
Authors: Liao Cheng Zhu , Bao Su Ping , Tjong Sie Chin
Published: October 2011

Maleated high‐density polyethylene (mPE) consisting of 95 wt% high‐density polyethylene and 5 wt% polyethylene‐graft‐maleic anhydride was filled with 2–4 wt% silicon carbide nanoparticles (SiCp) and toughened with 10–30 wt% poly(styrene‐ethylene‐butylene‐styrene) (SEBS). Such mPE nanocomposites were compounded in a twin‐screw extruder followed by injection molding. The effects of SEBS elastomer and SiCp additions on the structure, thermal and mechanical behavior, and fracture toughness of mPE composites were studied using X‐ray diffraction (XRD), polarizing optical microscopy (POM), differential scanning calorimetry (DSC), heat deflection temperature (HDT), tensile test, Izod impact, and essential work of fracture (EWF) techniques. XRD and POM results showed that SEBS and SiCp additions reduce the crystallite thickness and spherulite size of mPE. DSC and HDT measurements revealed that SiCp addition promotes nucleation of HDPE crystals and markedly increases the range of elevated temperature over which mPE hybrids maintain adequate stiffness. Tensile test results showed that SEBS reduces the Young's modulus and yield strength of mPE, whereas SiCp stiffens and reinforces the mPE/SEBS blend. The Izod impact test was conducted at liquid nitrogen temperature. The impact strength of mPE/SEBS/SiCp hybrids improved dramatically with increasing SEBS content. EWF results obtained at room temperature showed that the specific EWF of mPE/SEBS blends and mPE/SEBS/SiCp hybrids also increases with increasing SEBS content. © 2011 Wiley Periodicals, Inc. Adv Polym Techn 30: 322–333, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.20228
In vitro degradation and drug‐release behavior of electrospun, fibrous webs of poly(lactic‐co‐glycolic acid)
Authors: Hong Kyung Hwa , Woo Seok Hoon , Kang Tae Jin
Published: October 2011

Ultrafine fibrous webs of poly(lactide‐co‐glycolic acid) (PLGA) containing the bactericidal antibiotic drug rifampin were prepared by electrospinning, and their properties were investigated for wound‐dressing applications. Because PLGA is a biodegradable and biocompatible polymer, it is one of the best materials for the preparation of wound‐dressing substrates. Through this investigation of PLGA/rifampin electrospun webs, we found that the in vitro degradation reached approximately 60% in 10 days, and the drug release from the webs showed a fast and constant profile suitable for wound‐dressing applications. Also, we observed that both the web‐degradation rate and the drug‐release rate increased as the drug concentration in the PLGA/rifampin electrospun webs and the content level of glycolide units in the PLGA polymer matrix increased. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Effect of particulate fillers on thermal expansions and other critical performances of polycarbonate‐based compositions
Authors: DeSarkar Mousumi , Senthilkumar P. , Franklin Sushmita , Chatterjee Gautam
Published: October 2011

Influence of different inorganic particulate mineral fillers on polycarbonate composites was explored. Among all the fillers assessed here only boron nitride and mica could appreciably reduce the thermal expansion of polycarbonate, particularly along the direction of flow. While measured in the normal to flow (cross‐flow) direction, the coefficient of thermal expansion (CTE) values decreased marginally in presence of boron nitride and mica as compared to the unfilled specimen. The anisotropicity in CTE is presumable due to preferential orientation of boron nitride and mica along the direction of flow in the injection molded samples. The effectiveness of fillers in reducing CTE of the polycarbonate composites was correlated to the dispersion of fillers in the polymer matrix. Better dispersion of boron nitride and mica, as observed through SEM, ensured their improved interaction with the matrix and thereby reducing the CTE. It was observed that in presence of particulate fillers the impact performance of the composites decreased appreciably with an increase in tensile modulus, in general. The flow behavior of the composites was by large dependent on the types of fillers used. In presence of some of the fillers such as BaSO4, ZnO, ZnS, TiO2, and alumina, flow of the composites increases significantly, primarily associated to appreciable reduction in molecular weights of the polycarbonate. On the other hand, with boron nitride flow remained almost unchanged upon its addition of 5 vol %. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Effect of thermal treatment on structure and properties of polyester tire cords
Authors: Rath J. P. , Chaki T. K. , Khastgir D.
Published: October 2011

Polyester and nylon are the mostly used reinforcing textile fibers in many industrial rubber applications. Now‐a‐days body ply of a passenger car radial is mostly made up of polyester fiber. Because of its thermoplastic nature, it undergoes some kind of thermal shrinkage during processing and vulcanization, which lead to many problems related to shape, dimension, and dimensional stability. To avoid this, polyester is subjected to thermal treatment at higher temperature. Hence, thermomechanical properties of polyester tire cords become very important. During the thermal treatment, there is not only change in shrinkage, shrinkage force, and mechanical properties but also it affects structural and morphological properties. In this work, the changes in thermomechanical properties due to heat setting have been correlated to structural and morphological changes like crystallinity, crystal size, orientation, crystal perfection, etc. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Solid‐state structural evolution of poly(ethylene terephthalate) during step uniaxial stretching from different initial morphologies: An in situ wide angle x‐ray scattering study
Authors: Todorov Lyudmil V. , Martins Carla I. , Viana Júlio C.
Published: October 2011

This work reports an in situ wide‐angle X‐ray scattering (WAXS) study of the structural evolution of PET with distinct initial morphologies during step uniaxial stretching in the solid state. Two types of samples were analyzed under synchrotron X‐ray radiation, namely quasi‐amorphous (QA) and semicrystalline (SC) (with 2D and 3D order). Results show that initially different QA morphologies evolve following the same stages: (i) stage I (before neck), at almost constant orientation level the amorphous phase evolves into mesophase; (ii) stage II (neck formation), there is a rapid increase of polymer orientation and the appearance of a periodical mesophase from the highly oriented mesophase; (iii) stage III (necking propagation), there is a leveling off of the average polymer orientation together with partial conversion of the periodical mesophase and mesophase into highly oriented amorphous. The behaviors of the two SC morphologies are completely distinct. A 2D order crystalline morphology evolves with stretching likewise the QA through three stages: (i) at early stages of deformation the polymer orientation remains unchanged while the amorphous phase amount increases slightly, stage I; (ii) in stage II, a fast increase of polymer orientation is accompanied by large formation of mesophase; and (iii) in stage III there is the level off of polymer orientation as the chains approach their finite extensibility and the 3D crystalline order is achieved. Evolution of SC sample with 3D crystalline order mainly features constant orientation increase together with mesophase increment. Structure deformation models are suggested. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Simple kinetic numerical model based on rheometer data for ethylene–propylene–diene monomer accelerated sulfur crosslinking
Authors: Milani G. , Milani F.
Published: October 2011

A simple numerical model for the interpretation of the reaction kinetics in ethylene–propylene–diene monomer (EPDM) vulcanized with accelerated sulfur is presented. The model is based on the assumption that during vulcanization, a number of partial reactions occurs, both in series and in parallel, which determine the formation of intermediate compounds, including activated and matured polymers. Once written a standard first‐order differential equation (DIFF‐EQ) for each partial reaction, an ordinary DIFF‐EQ system (ODEs), was obtained and solved through Runge–Kutta algorithms. Alternatively and more efficiently, a single second‐order nonhomogenous DIFF‐EQ with constant coefficients was deduced, for which a closed‐form solution was derived, provided that the nonhomogenous term was approximated with an exponential function. Kinetic constants were evaluated through experimental data fitting on standard rheometer tests. To assess model predictions, an experimental campaign at different temperatures on two EPDM compounds was performed. They exhibited moderate reversion at intermediate and high curing temperatures. A nonlinear least‐squares fitting was performed to evaluate unknown constants entering into the DIFF‐EQ model proposed. Scaled rheometer curves fit rather well, also in the presence of reversion. In addition, partial reaction kinetic constants were provided: this gave an interesting insight into the different reticulation processes occurring during vulcanization. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Reduction in percolation threshold of injection molded high‐density polyethylene/exfoliated graphene nanoplatelets composites by solid state ball milling and solid state shear pulverization
Authors: Jiang Xian , Drzal Lawrence T.
Published: October 2011

Previous work showed that high density polyethylene (HDPE)/exfoliated graphene nanoplatelets (GNP) nanocomposites fabricated with melt extrusion followed by injection molding had a relatively high percolation threshold of between 10 and 15 vol % GNP loading. To lower the percolation threshold of injection molded HDPE/GNP nanocomposites, two special processing methods were investigated: solid state ball milling (SSBM) and solid state shear pulverization (SSSP). Results have confirmed that the percolation threshold of HDPE/GNP nanocomposites could be reduced to between 3 and 5 vol % GNP loading by these two approaches. The mechanism by which SSBM and SSSP are capable of producing lower percolation is to coat the polymer surface with GNP platelets which facilitates the formation of conductive networks during injection molding. However, it was found that HDPE/GNP nanocomposites obtained from these two techniques exhibited lower mechanical properties at high GNP loadings. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Transitions of morphological patterns of crystallizing polycarbonate in thin films
Authors: Ye Yuesheng , Kim Bohyun , Seog Joonil , Yong Choi Kyu
Published: October 2011

This article reports the transitions of morphological patterns of polycarbonate crystals in thin films by solvent‐induced crystallization (SINC). As a substrate (silica glass) deposited with an amorphous and micron‐thick bisphenol A polycarbonate polymer film is partially dipped into a liquid acetone bath, acetone penetrated rapidly through the polymer film. The rate of acetone penetration is significantly higher than the predicted by Fickian diffusion or anomalous diffusion model, indicating that the capillary force through stress‐induced cracks may have played a major role in the upward transport of acetone through the polymer films. The morphologies of polycarbonate at different vertical positions on a substrate surface were analyzed by scanning electron microscopy and atomic force microscopy. It was observed that depending on the local acetone concentration the polymer morphologies showed quite diverse patterns ranging from stress‐induced cracks to fully developed three‐dimensional spherulites. The diverse morphologies developed during the thin film SINC may serve as a useful platform for further detailed mechanistic analysis of structures and crystallization kinetics. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Miscibility of mixed stereoregular PMMA/PVCN monolayers at the air/water interface
Authors: Hsu Wen‐Ping , Chiou Ming‐Shen , Li Hsing‐Ya
Published: October 2011

The mixed monolayer behavior of stereoregular poly(methyl methacrylate) (PMMA) and poly(vinyl cinnamate) (PVCN) was investigated from the measurements of surface pressure–area per molecule (π–A) isotherms at three different temperatures of 25 ± 1, 32.5 ± 1, and 40 ± 1°C. The miscibility and nonideality of the mixed monolayers were examined by calculating the excess area as a function of composition. Positive and negative deviations from ideality were observed. Negative deviations were observed mostly in syndiotactic PMMA (sPMMA) and PVCN blends suggesting the existence of favorable interactions. However, positive deviations in most isotactic PMMA (iPMMA) and PVCN blends indicated that the existence of unfavorable interactions. Atactic PMMA and PVCN blends demonstrated intermediate deviation behavior to sPMMA and iPMMA blends. On the basis of the results of π–A isotherms, the monolayer miscibility between PMMA and PVCN was in the majority not in agreement with the studies on the same blends in the bulk state. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Epoxy composites based on amino‐silylated MMT: The role of interfaces and clay morphology
Authors: Piscitelli Filomena , Scamardella Anna Maria , Romeo Valentina , Lavorgna Marino , Barra Giuseppina , Amendola Eugenio
Published: October 2011

Epoxy‐based composites containing sodium montmorillonite (MMT) modified by silylation reaction with 3‐aminopropyltriethoxysilane (A1100) and N‐(2‐aminoethyl)‐3‐aminopropyltrimethoxysilane (A1120) were prepared. The effect of MMT chemical functionalization, as well as inorganic content and dispersion method (i.e., sonication or combination of sonication and ball‐milling) on the morphology and mechanical and thermal properties of composites was thoroughly investigated by X‐ray diffraction analysis, dynamic mechanical and tensile static analysis, nanoindentation measurements and cone calorimeter tests. Morphological characterization showed that the MMT particles are only slightly intercalated by epoxy molecules. Tensile stress, elongation at failure, and toughness of the epoxy composites based on silylated MMT were found to be improved. The presence of 1 and 3% wt/wt of A1100 and A1120 silylated MMT clays allowed the tensile elastic modulus to increase respectively, of about 10 and 15% with respect to the pristine epoxy matrix. The overall results showed that (1) the silylation of MMT clays is a valuable method to improve the interfacial interaction between filler and epoxy matrix and (2) the interfacial interaction plays a role more significant than the clay morphology (i.e., the extent of clay intercalation/exfoliation) over the composite properties. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Synthesis and Immunomodulating Activity of New Analogues of Fingolimod
Authors: Feng Xiang‐Jun , Yang Xiao‐Ying , Luo Yu , Li Xin , Tang Wei , Zuo Jian‐Ping , Lu Wei
Published: October 2011

Five new immunomodulators 1a–1e by using a trans‐4‐alkyl‐substituted cyclohexane to replace the flexible C8 alkyl chain of Fingolimod were synthesized. For in‐vitro test, the compounds were dissolved in DMSO as a stock solution and diluted to a desired concentration with RPMI 1640 nutrient solution. For in‐vivo test, the compounds were prepared in pathogen‐free saline containing 0.5% DMSO. These new immunomodulators displayed more potent immunoinhibitory activities in vitro and moderate immunomodulating activities in vivo. They show therapeutic effects on DNFB‐induced DTH reaction and inhibitory effects on the antigen‐specific T‐cell proliferation.
Virtual cerebral ventricular system: An MR‐based three‐dimensional computer model
Authors: Adams Christina M. , Wilson Timothy D.
Published: October 2011

The inherent spatial complexity of the human cerebral ventricular system, coupled with its deep position within the brain, poses a problem for conceptualizing its anatomy. Cadaveric dissection, while considered the gold standard of anatomical learning, may be inadequate for learning the anatomy of the cerebral ventricular system; even with intricate dissection, ventricular structures remain difficult to observe. Three‐dimensional (3D) computer reconstruction of the ventricular system offers a solution to this problem. This study aims to create an accurate 3D computer reconstruction of the ventricular system with surrounding structures, including the brain and cerebellum, using commercially available 3D rendering software. Magnetic resonance imaging (MRI) scans of a male cadaver were segmented using both semiautomatic and manual tools. Segmentation involves separating voxels of different grayscale values to highlight specific neural structures. User controls enable adding or removing of structures, altering their opacity, and making cross‐sectional slices through the model to highlight inner structures. Complex physiologic concepts, such as the flow of cerebrospinal fluid, are also shown using the 3D model of the ventricular system through a video animation. The model can be projected stereoscopically, to increase depth perception and to emphasize spatial relationships between anatomical structures. This model is suited for both self‐directed learning and classroom teaching of the 3D anatomical structure and spatial orientation of the ventricles, their connections, and their relation to adjacent neural and skeletal structures. Anat Sci Educ. © 2011 American Association of Anatomists.
On somatic mutations and tissue fields in cancer
Authors: Daniel Satgé
Published: October 2011

Editor's suggested further reading in BioEssays: Fields and field cancerization: The preneoplastic origins of cancer Abstract