bluuebunny/crossref_metadata_2025_split huggingface dataset:
Production of XNBR/PMMA through in Situ Polymerization
Authors: Rezende Carolina Guedes Fioravante , Caetano Skarllet Toledo , de Almeida André , de Oliveira Paulo Jansen 
Published: February 2011

AbstractIn this work, acrylonitrile‐butadiene rubber / poly(methyl methacrylate) (XNBR/PMMA) blends were obtained through in situ polymerization of methyl methacrylate (MMA) monomer in XNBR rubber particles. Firstly, the XNBR rubber was swollen with MMA and then the polymerization was carried out in an aqueous medium, keeping the rubber particles in suspension. The results of the swelling tests indicated that mass transfer of MMA to rubber particles is more efficient in aqueous system. Fourier Transform Infrared (FTIR) analyses revealed the presence of PMMA in the XNBR phase. Thermo‐gravimetrical (TG) analyses indicated that as much as 10% of PMMA was present in the blends. Scanning electron microscopy (SEM) analyses revealed that PMMA was dispersed in the XNBR phase, indicating the efficiency of the MMA polymerization inside the XNBR rubber particles.
Characterization of Electrolyte Polyester Membranes for Application in PEM Fuel Cells
Authors: Fiuza Raildo A. , Santos Irani V. , Fiuza Raigenis P. , José Nadia M. , Boaventura Jaime Soares 
Published: February 2011

AbstractOne of the factors that limits the lifetime of proton exchange membrane fuel cells (PEMFC) is the chemical stability of the polymeric membrane electrolyte operating at cell conditions. This work studies the thermal stability of a novel family of electrolyte membranes for use in fuel cells. The membranes were prepared by two different methods: Firstly, the MEB series were prepared by the addition of sodium dodecyl sulphate (SDS) to the resin obtained from the polymerization of terephthalic and adipic acid with glycerol. Secondly, the MP series were prepared from the polymerization of maleic acid and glycerol, phosphotungstic acid (PWA) was afterwards added to this material. The composites were processed in a reactor and shaped by hot pressing, yielding homogeneous and flexible slabs with an excellent surface finish. The materials were characterized by Thermo‐gravimetric analysis (TGA), Scanning‐electron microscopy (SEM), and electric conductivity measurements. The developed materials showed good properties as electrolytes for PEM fuel cells operating at temperatures above 100 °C.
Wie Reach die Produktion verändert
Authors: Geldsetzer Felix O. 
Published: February 2011

AbstractIn Deutschland existiert kein einheitliches Anlagenrecht, das die menschliche Gesundheit und die Umwelt vor Emissionen aus Industrieanlagen schützt. Stattdessen sind die stoffbezogenen Vorschriften auf das Chemikalien‐, Immissionsschutz‐, Wasser‐ und Abfallrecht verteilt. Wie wirken sich die neuesten EU‐Verordnungen bei Industrieanlagen aus?
Hybride aus DNA, Proteinen und Kolloiden
Authors: Rabe Kersten S. , Niemeyer Christof M. 
Published: February 2011

AbstractNeuartige halbsynthetische Hybride entstehen aus Molekülen biologischen und synthetischen Ursprungs. Das Ziel der Forschung sind Funktionseinheiten für Anwendungen in der Sensorik, Katalyse und Materialwissenschaft.
Abbaubare Polymere in der Medizin
Authors: Lendlein Andreas , Hofmann Dieter , Scharnagl Nico 
Published: February 2011

AbstractPolymerbasierte, abbaubare Biomaterialien sind eine Schlüsseltechnik für die moderne Medizin. Sie kommen in verschiedenen Medizinprodukten und Wirkstofffreisetzungssystemen zum Einsatz. Es ist zu erwarten, dass multifunktionale Polymere wesentliche Beiträge zu kausalen (regenerative Medizin), schonenden (minimalinvasive Medizin) und gezielten (Nanomedizin) Therapien leisten werden.
Verdienen Sie genug?
Authors: Schmitz Karin 
Published: February 2011

AbstractDie Gehaltsumfrage der GDCh startet wieder, diesmal mit früherem Einsendeschluss. In diesen Tagen gibt es die Fragebögen. Wie immer ist die Broschüre mit den Ergebnissen den Teilnehmern vorbehalten.
On the use of the extended finite element method with quadtree/octree meshes
Authors: Legrain G. , Allais R. , Cartraud P. 
Published: February 2011

AbstractThis paper describes the use of the extended finite element method in the context of quadtree/octree meshes. Particular attention is paid to the enrichment of hanging nodes that inevitably arise with these meshes. An approach for enforcing displacement continuity along hanging edges and faces is proposed and validated on various numerical examples (holes, material interfaces, and singularities) in both 2D and 3D. Copyright © 2010 John Wiley & Sons, Ltd.
An occupational therapy programme in a religious community in South Africa: A Historical Narrative
Authors: Birkhead Sylvia 
Published: February 2011

AbstractThe purpose of this paper was to describe an occupational therapy programme that addressed the needs of younger nuns as they faced the difficulties of caring for older nuns in a Dominican old‐age home in South Africa.Weekly occupational therapy group sessions with the younger sisters over a 1‐year period enabled them to cope with an elderly population who were struggling to adapt to life in an old‐age home. Activity groups and individual sessions were run concurrently with the older sisters. Aspects addressed included: dealing with loss, exploring meaningful activity, communication, healthy lifestyles, community involvement and life review.No formal outcome measures were used. Informal evidence of the effectiveness of the programme is the occupationally healthy community observed 20 years later. The younger enablers are now the care receivers and play an integral part in sustaining the programme.Although the Dominican community has specific needs and practices, there is a parallel to other groups of older adults adjusting to a care setting. This programme can serve as a model to facilitate the quality of life of caregivers and residents. The programme outcomes support the principles of occupational science by demonstrating the importance of engaging in meaningful activities to maintain health and well‐being. Copyright © 2011 John Wiley & Sons, Ltd.
Computer modeling of the crystallization process of single‐chain ethylene/1‐hexene copolymers from dilute solutions
Authors: Ramos J. , Martínez‐Salazar J. 
Published: February 2011

AbstractLangevin molecular dynamics (LMD) simulations have been performed to understand the role of the short chain branches (SCB) on the formation of ordered domains by cooling dilute solutions of ethylene/α‐olefins copolymer models. Three different long single‐chain models (C2000) with 0, 5, and 10 branches each 1000 carbons were selected. These models were equilibrated at high reduced temperature (T* = 13.3) and cooling in steps of 0.45 until the final temperature (T* = 6.2) by running a total of 35 × 106 LMD steps. During the cooling process, global order parameter, torsion distribution, position of the branches, and local‐bond order parameter were calculated and monitored. The peaks of crystallization for each model were calculated by differentiating the global order parameter with temperature. The Tc (crystallization temperature) decreases as the number of branches increases as has been experimentally reported. The formation of order in the copolymers is affected by the amount of the SCB in the backbone of the polymer chain. Initially, the SCB move to the folding surface. Once the SCB are located near the folding surface the order starts to grow. In all cases here shown, the C4 branches are excluded from the ordered domains. To take into account, the influence of the branch distribution, a different branch distribution model has been considered for the two‐branched systems. The crystallization fraction (α) and the density of the amorphous and ordered fractions was defined using the local‐bond order parameter. Both magnitudes decrease as the number of branches increases. These facts fairly agree with experimental literature data. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011
Simulation of the ultrafast nonlinear optical response of metal slabs
Authors: Wand Mathias , Schindlmayr Arno , Meier Torsten , Förstner Jens 
Published: February 2011

AbstractWe present a nonequilibrium ab initio method for calculating nonlinear and nonlocal optical effects in metallic slabs with a thickness of several nanometers. The numerical analysis is based on the full solution of the time‐dependent Kohn–Sham equations for a jellium system and allows to study the optical response of metal electrons subject to arbitrarily shaped intense light pulses. We find a strong localization of the generated second‐harmonic current in the surface regions of the slabs.
Field‐induced ion transfer for deposition on pointed tips and field emission
Authors: Kim Wal Jun , Lee Seung Min , Kim Yong Hyup 
Published: February 2011

AbstractA fabrication technique is presented for depositing a metal film only on pointed tips by field‐induced ion transfer (FIIT) in ambient atmosphere. The technique involves transferring metal ions dissolved in electrolyte solution only onto the pointed tip with electric field and it does not require any photolithographic process. To demonstrate the usefulness of the technique, carbon nanotubes are synthesized on the nickel film formed on a tungsten tip. The field emitter thus fabricated exhibits excellent emission characteristics. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Interaction of Spherical Silica Nanoparticles with Neuronal Cells: Size‐Dependent Toxicity and Perturbation of Calcium Homeostasis
Authors: Ariano Paolo , Zamburlin Pollyanna , Gilardino Alessandra , Mortera Renato , Onida Barbara , Tomatis Maura , Ghiazza Mara , Fubini Bice , Lovisolo Davide 
Published: February 2011

AbstractThe effects of Stöber silica nanoparticles on neuronal survival, proliferation, and on the underlying perturbations in calcium homeostasis are investigated on the well‐differentiated neuronal cell line GT1‐7. The responses to nanoparticles 50 and 200 nm in diameter are compared. The 50‐nm silica affects neuronal survival/proliferation in a dose‐dependent way, by stimulating apoptotic processes. In contrast, the 200‐nm silica does not show any toxic effect even at relatively high concentrations (292 μg mL−1). To identify the mechanisms underlying these effects, the changes in intracellular calcium concentration elicited by acute and chronic administration of the two silica nanoparticles are analyzed. The 50‐nm silica at toxic concentrations generates huge and long‐lasting increases in intracellular calcium, whereas the 200‐nm silica only induces transient signals of much lower amplitude. These findings provide the first evidence that silica nanoparticles can induce toxic effects on neuronal cells in a size‐dependent way, and that these effects are related to the degree of perturbation of calcium homeostasis.
New measurements of the surface ionization for quantitative electron probe microanalysis
Authors: Merlet C. , Llovet X. 
Published: February 2011

AbstractWe report new measurements of the surface ionization Φ(0) for Ge Kα and Lα X‐rays on an Fe substrate, Ga Kα and Lα X‐rays on an Ni substrate, and Au Mα X‐rays on Si, W and Ta substrates. The measurements were performed using the tracer technique for electron incident energies ranging from the ionization threshold up to about 40 keV. Improvements in sample preparation and in the X‐ray measurement technique enabled surface ionization values to be obtained with uncertainties less than 2%. Simulations of Φ(0) for the studied cases were performed using the general‐purpose Monte Carlo (MC) code PENELOPE. Experimental measurements are compared with simulation results and with the results of several predictive formulae widely used in electron probe microanalysis and Auger electron spectroscopy (AES). The accuracy of the reported measurements makes it possible to assess the reliability of the different calculations for incident electron energies below 10 keV. Copyright © 2011 John Wiley & Sons, Ltd.
Comparison of Major Hepatectomy Performed Under Intermittent Pringle Maneuver Versus Continuous Pringle Maneuver Coupled with In Situ Hypothermic Perfusion
Authors: Wang Chih‐Chi , Yap Anthony Q. , Chen Chao‐Long , Concejero Allan M. , Lin Yu‐Hung 
Published: February 2011

AbstractBackgroundThe Pringle maneuver (hepatic inflow occlusion), applied intermittently or continuously, carries the risk of inducing ischemic and reperfusion injury. The risk of damage is higher in the latter procedure. Studies have shown that continuous Pringle maneuver coupled with in situ hypothermic perfusion (CPM‐HP) circumvents such adversity. However, reports comparing this technique with the intermittent Pringle maneuver (IPM) are lacking. We therefore report our experience with the use of CPM‐HP and compare its outcome with that of IPM.MethodsWe evaluated the outcome of similar sets of patients who had major hepatic resections performed under IPM and CPM‐HP. Variables including short‐term survival rate (>90 days), complications, operative time, transection time, intraoperative blood loss, postoperative liver functions, and postoperative hospital stay were used to compare the two groups.ResultsEighteen major hepatectomies were performed with CPM‐HP and 16 with IPM. CPM‐HP was safely performed in patients with chronic liver disease. Lowering the liver’s temperature extends the clamping period to 140 min. Perioperative outcomes including operative time (383.9 ± 89.4 vs. 351.9 ± 70.3 min, p = 0.252), blood loss (225.6 ± 48.4 vs. 351.9 ± 70.3 ml, p = 0.057), postoperative hospital stay, morbidity rate, and the rate of liver functions following resections were comparable for the CPM‐HP and IPM groups. There was no mortality. Parenchymal transection time was significantly longer in the CPM‐HP group (104.1 ± 20.2 vs. 85.0 ± 15.4 min, p = 0.004)ConclusionOur findings did not show there to be a significant advantage of CPM‐HP over IPM.
Clinical, Ultrasonographic, and Pathologic Characteristics of Patients with Chronic Right‐lower‐quadrant Abdominal Pain that May Benefit from Appendectomy
Authors: Chichom Mefire Alain , Tchounzou Robert , Kuwong Patrick M. , Atangana Jean P. A. , Lysinge Albert C. , Malonga Eimo E. 
Published: February 2011

AbstractBackgroundChronic pains of the right lower quadrant of the abdomen (RLQA) remain a challenging problem worldwide, especially in areas with limited technical background; chronic appendicitis is still a subject of controversy. The aim of this study was to analyze the clinical and paraclinical data of patients with chronic pains of RLQA who had an appendectomy performed.MethodsDuring a period of 4 years, all patients presenting with a chronic pain of the RLQA were selected for our study and underwent clinical assessment and systematic ultrasonography of the abdomen; these served as a basis of selecting candidates for appendectomy. The intraoperative findings, histology results, and outcome after appendectomy were analyzed.ResultsThree hundred nineteen patients presented with chronic pains of the RLQA of which 213 could be finally analyzed; their mean age was 15.3 years; 192 patients were females. They had pains for 2‐8 years. Echography showed a heterogeneous lesion in the RLQA in 87% of the cases. The operative findings displayed adhesions and other signs of chronic inflammation in 182 cases. Pathological analysis frequently revealed fibrosis and lymphoplasmocytic infiltration indicative of chronic inflammation. Eighty‐seven percent of the patients were cured by appendectomy.ConclusionsThere is a chronic process involving the appendix that occurs in the RLQA of patients with chronic pains, typically the adolescent female. Appendectomy usually solves the problem. The criteria for selection of candidates still need to be identified, but in the absence of laparoscopic facilities, we recommend appendectomy when no other cause for the pain has been identified.
Weevils and camellias in a Darwin's race: model system for the study of eco‐evolutionary interactions between species
Authors: Toju Hirokazu 
Published: February 2011

AbstractOrganisms are surrounded by their predators, parasites, hosts, and mutualists, being involved in reciprocal adaptation processes with such “biotic environment”. The concept of “coevolution”, therefore, provides a basis for the comprehensive understanding of evolutionary and ecological dynamics in biological communities and ecosystems. Recent studies have shown that coevolutionary processes are spatially heterogeneous and that traits mediating interspecific interactions can evolve rapidly in natural communities. Here, I discuss factors promoting the geographic differentiation of coevolutionary interactions, the spatial scales of the geographic structuring, and the pace of coevolutionary changes, reviewing findings in the arms race coevolution involving a long‐mouthed weevil and its host camellia plant. Evolutionary, ecological, and population genetic studies on the system illuminated that viewpoints from the aspect of “coevolving biosphere” were important for predicting how ongoing anthropogenic change in global environment alter the spatiotemporal dynamics of biological communities.
Impact of vitamin D metabolism on clinical epigenetics
Authors: Karlic Heidrun , Varga Franz 
Published: February 2011

Abstract
The bioactive vitamin D (VD) metabolite, 1,25-dihydroxyvitamin D3 regulates essential pathways of cellular metabolism and differentiation via its nuclear receptor (VDR). Molecular mechanisms which are known to play key roles in aging and cancer are mediated by complex processes involving epigenetic mechanisms contributing to efficiency of VD-activating CYP27A1 and CYP27B1 or inactivating CYP24 enzymes as well as VDR which binds to specific genomic sequences (VD response elements or VDREs). Activity of VDR can be modulated epigenetically by histone acetylation. It co-operates with other nuclear receptors which are influenced by histone acetyl transferases (HATs) as well as several types of histone deacetylases (HDACs). HDAC inhibitors (HDACi) and/or demethylating drugs may contribute to normalization of VD metabolism. Studies link VD signaling through the VDR directly to distinct molecular mechanisms of both HAT activity and the sirtuin class of HDACs (SIRT1) as well as the forkhead transcription factors thus contributing to elucidate complex epigenetic mechanisms for cancer preventive actions of VD.
The contingency effects of environmental uncertainty on the relationship between supply chain integration and operational performance
Authors: Wong Chee Yew , Boon‐itt Sakun , Wong Christina W.Y. 
Published: February 2011

AbstractThis paper extends prior supply chain research by building and empirically testing a theoretical model of the contingency effects of environmental uncertainty (EU) on the relationships between three dimensions of supply chain integration and four dimensions of operational performance. Based on the contingency and organizational information processing theories, we argue that under a high EU, the associations between supplier/customer integration, and delivery and flexibility performance, and those between internal integration, and product quality and production cost, will be strengthened. These theoretical propositions are largely confirmed by multi‐group and structural path analyses of survey responses collected from 151 of Thailand's automotive manufacturing plants. This paper contributes to operations management contingency research and provides theory‐driven and empirically proven explanations for managers to differentiate the effects of internal and external integration efforts under different environmental conditions.
Versorgung in ländlichen Regionen
Authors: Gerlinger Thomas 
Published: February 2011

Einleitung
Abwanderung, demographischer Wandel, ein Versagen der kassenärztlichen Bedarfsplanung sowie eine zu geringe Zahl an nachrückenden Allgemeinmedizinern führen in einer wachsenden Zahl von ländlichen Regionen zu Mängeln in der medizinischen Versorgung. Trotz einer Vielzahl unterschiedlicher Initiativen ist eine Lösung dieses Problems nicht in Sicht.
INEQUALITIES IN TERMS OF THE GÂTEAUX DERIVATIVES FOR CONVEX FUNCTIONS ON LINEAR SPACES WITH APPLICATIONS
Authors: DRAGOMIR S. S. 
Published: February 2011

AbstractSome inequalities in terms of the Gâteaux derivatives related to Jensen’s inequality for convex functions defined on linear spaces are given. Applications for norms, meanf-deviations andf-divergence measures are provided as well.
Performance and productivity of Nellore steers on rotationally stocked palisadegrass (Brachiaria brizantha) pastures in response to herbage allowance
Authors: HERLING V. R. , PEDREIRA C. G. S. , DE C. LUZ P. H. , BRAGA G. J. , MARCHESIN W. A. , MACEDO F. B. , DE LIMA C. G. 
Published: February 2011

SUMMARYHerbage allowance (HA) impacts performance of grazing cattle as well as sward structure and herbage yield. The objective of the current study was to compare average daily gain (ADG) of Nellore steers on Marandu palisadegrass (Brachiaria brizantha (Hochst ex A. Rich.) Stapf. cv. Marandu) pastures in response to HA. Treatments were applied as 5, 10, 15 and 20 kg dry matter (DM) per 100 kg live weight (LW) per day HA5, HA10, HA15 and HA20), in rotationally stocked pastures under a 35-day grazing cycle (28 days of rest and 7 days of grazing). The trial was carried out in Pirassununga, Brazil, during two summer seasons in 2003 and 2004, each divided into four grazing cycles. Individual animal (250 kg yearling steers) gain increased with HA up to HA15 (mean=0·69 kg/head per day) during each of four grazing cycles per year. The 2-year gain per area was greater for HA5 and HA10 than for HA15 and HA20 and average stocking rate was 9·6, 6·7, 5·4 and 4·6 head/ha for HA5 to HA20, respectively. In addition to the effects of HA on ADG, changes in sward structure, especially sward height, help to explain variation in daily gain in both years. The HA10 treatment provides higher gain per area without excessively reducing individual animal performance, and thus may be the level of choice for optimizing animal output in pasture-only systems.
The limitations of activation policies: unemployment at the end of working life
Authors: WUEBBEKE CHRISTINA 
Published: February 2011

ABSTRACTIn several European countries, older unemployed people, after reaching a certain age, are entitled to unemployment benefit payments without having to seek new employment. The coexistence of this exemption clause and of reforms aimed at containing early retirement in the respective countries reflects a conflict of political aims – on the one hand, between an efficient labour-market policy at a time of high unemployment, and on the other hand, the goal of the comprehensive activation and labour-market integration of older workers as a response to demographic change. This paper deals with the reasons for the transfer of older long-term unemployed people on to ‘facilitated benefits’ for labour-market withdrawal in Germany. The empirical analysis shows that low or no propensity to work was rarely the motive for leaving the labour market; in particular, those anticipating a low retirement income actually wanted to be re-employed. The vast majority gave three reasons for the decision to retire: an inability to cope with requirements of available jobs; a lack of job opportunities; and an absence of proper support from the public employment agency. Thus the withdrawal of older long-term unemployed people into pre-retirement cannot be attributed to a utility-maximising decision in favour of leisure and against gainful employment, but is the primary result of the scarce re-employment prospects.