bluuebunny/crossref_metadata_2025_split huggingface dataset:
Zukünftige Bemessung von Mauerwerk – Genaueres Verfahren
Authors: Graubner Carl‐Alexander , Brehm Eric , Kranzler Thomas 
Published: September 2009

AbstractNach intensiven Vorarbeiten in den zuständigen Normungsgremien wurde der Fachöffentlichkeit im März dieses Jahres eine Neufassung der Bemessungsnorm DIN 1053 für unbewehrte Mauerwerkswände als “Gelbdruck” vorgestellt, welche deutliche Änderungen im Vergleich zu den derzeit gültigen Vorschriften DIN 1053‐1:1996‐11 [1] und DIN 1053‐100:2007‐09 [2] aufweist. In die Überarbeitung sind vielfältige Forschungsaktivitäten der letzten Jahre, insbesondere auf dem Gebiet der Ermittlung der Querkrafttragfähigkeit, eingeflossen, weshalb ein auf dem neuesten Stand des Wissens basierendes Dokument vorliegt. Zukünftig werden das vereinfachte und das genauere Nachweisverfahren in getrennten Normenteilen DIN 1053‐11 [3] und DIN 1053‐13 [4] geregelt. Von besonderer Bedeutung ist, dass mit dem genaueren Nachweisverfahren nunmehr auch die normenkonforme Bemessung von Elementmauerwerk aus großformatigen Steinen mit Überbindemaßen 0,2 ≤ ü/hSt < 0,4 möglich ist, welches bisher ausschließlich über Zulassungen geregelt war. Des Weiteren ist festzustellen, dass das vereinfachte und das genauere Nachweisverfahren einheitlich mit den Schnittgrößen auf Bemessungswertniveau arbeiten. Daher wird die Anwendbarkeit des genaueren Nachweisverfahrens deutlich vereinfacht, und die sich aus der wirklichkeitsnäheren Modellierung ergebenden Tragfähigkeitssteigerungen – insbesondere bei schlanken, knickgefährdeten Wänden – können praxisnah genutzt werden. Der vorliegende Beitrag beschreibt die wesentlichen Änderungen im genaueren Nachweisverfahren nach DIN 1053‐13 und vergleicht exemplarisch die Bemessungsergebnisse mit den nach DIN 1053‐1 und DIN 1053‐11 erzielbaren Tragfähigkeiten.
Zukünftige Bemessung von Mauerwerk – Überblick und vereinfachtes Verfahren
Authors: Jäger Wolfram 
Published: September 2009

AbstractNachdem die DIN 1053‐100 [1] im September 2006 auf die Musterliste der Technischen Baubestimmungen [2] gesetzt worden war, stand der Einführung in den einzelnen Bundesländern nichts mehr im Wege, so dass heute flächendeckend in der Bundesrepublik das semiprobabilistische Sicherheitskonzept angewendet werden kann (s. [3] bis [6]). Die DIN 1053‐100 bezieht sich jedoch nur auf die Bemessung, für Ausführung und Konstruktion galt weiterhin DIN 1053‐1:1996‐11 [7].Im März diesen Jahres wurde nunmehr die vollständig überarbeitete DIN 1053‐1 als Entwurf veröffentlicht (s. [8] bis [11]). In ihr sind wieder Bemessung, Ausführung und Konstruktion auf gleichem zeitlichen Niveau vereinigt. Insbesondere im Bereich der Querkraftbeanspruchung von Mauerwerk hat es in den vergangenen Jahren erhebliche Aktivitäten gegeben, um das durch das Teil sicherheitskonzept eingetretene Defizit zu beseitigen. Weitere neuere Erkenntnisse und auch Notwendigkeiten sind hinzugekommen. Die Arbeit am Nationalen Anhang zu Eurocode 6 erforderte ebenfalls einen fundierten deutschen Standpunkt. Die europäischen Bestrebungen in der Mauerwerksnormung, die deutschen Erfahrungen und die neuen Erkenntnisse waren Anlass für eine völlige Neustrukturierung und Überarbeitung der deutschen Mauerwerksnorm für unbewehrtes Mauerwerk, die in diesem und dem anschließenden Beitrag vorgestellt wird.Insbesondere im vereinfachten Verfahren ist einiges reduziert und bereinigt worden, allerdings ist auch Neues hinzugekommen. Im genaueren Verfahren ist i. W. der Querkraftnachweis neu. Weitere Dinge sind dem Erkenntnisstand angepasst worden.
Brandschutz im Mauerwerksbau
Authors: Schneider Ulrich 
Published: September 2009

AbstractDer Mauerwerksbau ist eine der ältesten Bauweisen überhaupt und überzeugt durch hohe Dauerhaftigkeit und Sicherheit auch unter extremen Umgebungsbedingungen. In dem vorliegenden Beitrag wird zu Beginn diesbezüglich zurückgeblickt auf die römischen und mittelalterlichen Stadtbauweisen hinsichtlich ihres Verhaltens bei Bränden. Dominierend sind damals wie heute in jeder Hinsicht die Nichtbrennbarkeit und die hohe Festigkeit des Materials bei länger andauernden Temperatureinwirkungen.Hinsichtlich der bauordnungsrechtlichen Anforderungen und deren Umsetzung hat es in den letzten Jahren Veränderungen gegeben, die im Zusammenhang mit einer Neuordnung der Gebäudeklassifizierung und dem europäischen Normungsprozess stehen. Bei der Einteilung der Gebäude ist eine neue Klasse mit einer Fußbodenhöhe bis 13 m über Oberkante Gelände eingeführt worden ([1] bis [3]). Gleichzeitig sind die brandschutztechnischen Anforderungen bis einschließlich dieser Gebäudeklasse mit der Feuerwiderstandsanforderung “hochfeuerhemmend” abgesenkt worden. Es ist damit auch der Einsatz brennbarer Baustoffe für tragende Konstruktionen, allerdings nur unter bestimmten Voraussetzungen, möglich, was das ehemals vorhandene hohe Sicherheitsniveau in diesem Bausegment abmindert. Durch den Einsatz von Mauerwerk ist es aber trotzdem möglich, den ursprünglich hohen Standard auch weiterhin beizubehalten. Neuere Entwicklungen in der Mauerwerksindustrie haben derzeit soweit geführt, dass die Wandmaterialien neben einem sehr guten Brandschutz auch ohne zusätzlichen bzw. mit sehr geringem zusätzlichen Wärmeschutz bereits Passivhausqualität erreichen und als High‐Tech‐Bauteile gelten.Die bauordnungsrechtlichen Brandschutzanforderungen können sowohl mit Hilfe der deutschen als auch des europäischen Brandschutznormen umgesetzt werden (s. hierzu [4] bis [7]). Die europäischen Brandschutznormen enthalten einerseits ein System der Klassifizierung von Baustoffen und Bauteilen, jedoch in wesentlich differenzierterer Form als bisher in Deutschland üblich. Andererseits gestatten Bemessungsnormen für den Brandfall auch die rechnerische Nachweisführung, was dem Architekten bzw. dem Ingenieur mehr Freiheiten gibt. Diesbezüglich fehlen aber vor allem die zugehörigen Materialkennwerte in Abhängigkeit von den hohen Temperaturen, welche bei Bränden zu erwarten sind. Derartige Berechnungen sind u. a. auch dazu geeignet, die früheren Bauteilklassifizierungen nach den Brandschutzanforderungen des Eurocodes 6 neuerlich zu validieren.
Challenges in developing endpoints for type 1 diabetes intervention studies
Authors: Cernea Simona , Raz Itamar , Herold Kevan C. , Hirshberg Boaz , Roep Bart O. , Schatz Desmond A. , Fleming G. Alexander , Pozzilli Paolo , Little Randie , Schloot Nanette C. , Leslie R. David G. , Skyler Jay S. , Palmer Jerry P. 
Published: September 2009

AbstractDevelopment of efficient and safe intervention strategies for preserving and/or restoring endogenous insulin production in type 1 diabetes has encountered a wide range of challenges, including lack of standardized trial protocols and of consensus on appropriate efficacy endpoints. For the greatest part, difficulties resided in choosing the most suitable assay(s) and parameter(s) to assess the β‐cell function. It is now an accepted approach to evaluate endogenous insulin secretion by measuring C‐peptide levels (with highly sensitive and normalized measurement methods) in response to a physiologic stimulus (liquid mixed‐meal) under standardized conditions. Preventive interventions mandate the identification of well‐defined, reliable and validated mechanistic or immunological markers of efficacy that would correlate with (and predict) the clinical outcome. This has not been consistently achieved to date. However, it has been generally agreed that for preventive studies performed very early in the disease course (in subjects without signs of autoimmunity against β‐cells) development of two or more islet related autoantibodies could be employed as biomarkers of disease and thereafter, diagnostic criteria of diabetes serve as suitable endpoints.This report summarizes the conclusions of the D‐Cure workshop of international experts held in Barcelona in April 2007 and the current recommendations and updates in the field. Copyright © 2009 John Wiley & Sons, Ltd.
The Versatile Alkylidene Moiety in Ruthenium Olefin Metathesis Catalysts (Eur. J. Inorg. Chem. 28/2009)
Authors: Diesendruck Charles E. , Tzur Eyal , Lemcoff N. Gabriel 
Published: September 2009

AbstractThe cover picture shows the development of the ruthenium alkylidene moiety from the first well‐defined ruthenium vinylalkylidene disclosed by Grubbs, through the first simple benzylidenes, alkylidenes, Fischer carbenes, vinylidenes, allenylidenes and indenylidenes, up to the functional chelated alkylidenes. Indeed, the development of this fragment has had a vital impact on the ruthenium‐catalyzed olefin metathesis reaction. Details are presented in the Microreview by N. G. Lemcoff et al. on p. 4185 ff. The authors gratefully acknowledge the Edmond J. Safra Foundation for their financial support.
Chitosan and marine phospholipids reduce matrix metalloproteinase activity in myeloma SP2 tumor‐bearing mice
Authors: Hossain Zakir , Fukunaga Kenji , Tanouchi Masatoshi , Takahashi Koretaro 
Published: September 2009

AbstractAn animal experiment was conducted to assess the antitumor effects of chitosan‐coated liposomes on myeloma SP2. The animal experimental groups designed for myeloma SP2 tumor‐bearing BALB/c mice were provided with five different drinks: (I) control (double‐distilled water); (II) squid phospholipid liposomes alone 1.0 mg/mL; (III) chitosan alone 5.0 mg/mL; (IV) squid phospholipid liposomes 1.0 mg/mL with chitosan 5.0 mg/mL in the form of a simple mixture; and (V) squid phospholipid liposomes 1.0 mg/mL coated with chitosan 5.0 mg/mL. At 20 days after implantation of the myeloma SP2 cells into mice, oral administration of the experimental drinks was provided for 35 days. There was significant suppression of tumor growth when chitosan and squid phospholipids were administered simultaneously in a simple mixture or as chitosan‐coated liposomes. Matrix metalloproteinase (MMP)‐2 and MMP‐9 activity was significantly less in the serum of mice that consumed chitosan‐coated liposomes than in control mice. We found that decreased tumor burden was related to MMP secretion. Therefore, chitosan‐coated marine phospholipid liposomes might be useful as potential agents for the treatment of myeloma SP2.
Novel 1,4,5,8‐Phenanthrenediquinones and Unusual Deoxygenation with Trimethylsilyl Iodide
Authors: Krohn Karsten , Aslan Abdulselam , Ahmed Ishtiaq , Pescitelli Gennaro , Funaioli Tiziana 
Published: September 2009

AbstractAttempt for aryl methyl ether cleavage of 5,8‐dimethoxy‐1,4‐phenanthrenequinone (4) with boron trichloride or tribromide resulted in the halogenation of the quinone double bond to form 5a,b. Surprisingly, reaction of dimethyl ether 4 with trimethylsilyl iodide afforded the phenanthrenediquinone 6, whereas deoxygenation to 8 and 9 occurred by reaction of trimethylsilyl iodide with derivative 7. The phenanthrenediquinones 6 and 10 were obtained nearly quantitatively from 4 and 7 by using ceric ammonium nitrate as the oxidant. The cyclic voltammograms of the phenanthrenediquinones 6 and 10 were studied and rationalized by Hückel Molecular Orbital calculations. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Organocatalyzed α‐Oxyamination of Aldehydes Using Anodic Oxidation
Authors: Bui Nhat‐Nguyen , Ho Xuan‐Huong , Mho Sun‐il , Jang Hye‐Young 
Published: September 2009

AbstractElectrochemical oxidation was performed during the organocatalyzed α‐oxyamination of aldehydes by using a one‐compartment electrolytic cell under galvanostatic conditions. In the presence of substoichiometric amounts of sec‐amines, the desired coupling products were formed in good yield. The asymmetric variant of the α‐oxyamination of aldehydes was examined by using chiral sec‐amines. Control experiments and cyclic voltammetry confirmed the key intermediate of this reaction to be the cationic radical of the enamine derived from the sec‐amine catalysts and aldehydes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Palladium‐Free Synthesis of Conjugated Enynes by Direct Olefination of Terminal Alkynes Using Vinyl Bromides
Authors: Liu Yunyun , Yang Jianguo , Bao Weiliang 
Published: September 2009

AbstractA series of conjugated enynes were successfully synthesized by the direct copper‐catalyzed coupling reaction of vinyl bromides and alkynes. The reaction proceeds smoothly in DMF at 110 °C to give the corresponding products in good to excellent yields. The protocol is tolerant to a broad range of functional groups on the substrates. Moreover, the products were furnished as specific E isomers, as the stereochemistry of the vinyl bromides was retained. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Decision making under risk in Deal or No Deal
Authors: de Roos Nicolas , Sarafidis Yianis 
Published: September 2009

AbstractWe analyse the choices of 399 contestants in the Australian version of the television game show Deal or No Deal. We calculate risk aversion bounds for each contestant, revealing considerable heterogeneity. We then estimate a structural stochastic choice model that captures the dynamic decision problem faced by contestants. To address individual heterogeneity, we nest the dynamic problem within the settings of both a random effects and a random coefficients probit model. Our structural model produces plausible estimates of risk aversion, confirms the role of individual heterogeneity and suggests that a model of stochastic choice is indeed appropriate. We find mixed evidence of greater risk aversion by females. We also examine generalizations to expected utility theory, finding that the rank‐dependent utility model adds non‐negligible explanatory power and indicates optimism in probability weighting. Finally, we test, but are unable to confirm, the existence of an endowment effect for lotteries. Copyright © 2009 John Wiley & Sons, Ltd.
Scoring of collagen organization in healthy and diseased human dermis by multiphoton microscopy
Authors: Cicchi Riccardo , Kapsokalyvas Dimitrios , De Giorgi Vincenzo , Maio Vincenza , Van Wiechen Annelies , Massi Daniela , Lotti Torello , Pavone Francesco S. 
Published: September 2009

AbstractWe have used nonlinear imaging to evaluate collagen organization in connective tissue ex‐vivo samples. Image analysis methods were tested on healthy dermis, normal scars, and keloids. The evaluation of the second harmonic to autofluorescence aging index of dermis (SAAID) has allowed a first characterization of tissues by scoring the collagen/elastin content. Further analyses on collagen morphology in healthy dermis and keloids were performed by image‐pattern analysis of SHG images. The gray‐level co‐occurrence matrix (GLCM) analysis method has allowed classification of different tissues based on the evaluation of geometrical arrangement of collagen fibrillar bundles, whereas a pattern analysis of the FFT images has allowed the discrimination of different tissues based on the anisotropy of collagen fibers distribution. This multiple scoring method represents a promising tool to be extended to other collagen disorders, as well as to be used in in‐vivo skin‐imaging applications. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthesis of CdS‐ and ZnS‐modified bentonite nanoparticles and their applications to the degradation of eosin B
Authors: Ghiaci M. , Sedaghat M.E. , Aghaei H. , Gil A. 
Published: September 2009

AbstractBACKGROUND: In the present study, nanocomposites of cadmium sulphide (CdS) and zinc sulphide (ZnS) on a bentonite have been prepared via an in‐situ precipitation route and their catalytic behaviour was evaluated in the degradation of eosin B.RESULTS: It was found that the basal space of bentonite increased from 1.23 to 1.49 nm after CdS or ZnS nanoparticles were deposited on layers of the bentonite. The resulting CdS–bentonite and ZnS–bentonite nanocomposites can degrade eosin B from aqueous solution after 2 h under UV irradiation.CONCLUSION: A soft method for in situ synthesis of monodispersed, CdS and ZnS nanoparticles, using a reverse micelle type procedure, is reported. The synthesized CdS‐ and ZnS–bentonite composites combined the adsorptive ability of bentonite and the catalytic degradation ability of CdS and ZnS to remove eosin B from its aqueous solution efficiently. Copyright © 2009 Society of Chemical Industry
Interaction of ‘toxic’ and ‘immunogenic’ A‐gliadin peptides with a membrane‐mimetic environment
Authors: Vilasi S. , Sirangelo I. , Irace G. , Caputo I. , Barone M. V. , Esposito C. , Ragone R. 
Published: September 2009

AbstractCeliac disease (CD) is characterized by abnormally high concentrations of certain peptides in the small bowel. These peptides can be grouped in ‘toxic’ and ‘immunogenic’ classes, which elicit an innate immune response and an HLA‐mediated adaptive response, respectively. It is not clear on which molecular mechanisms responses to these different classes are based, but the 31–43 (P31–43) and the 56–68 (P56–68) A‐gliadin fragments are usually adopted as sequence representatives of toxic and immunogenic peptides, respectively. Here we report fluorescence experiments aiming to mimic the interaction of these peptides with the cell membrane surface by using sodium dodecyl sulphate (SDS) as a membrane‐mimetic medium. We show that P31–43 is able to bind SDS micelles in a way that resembles mixed micelle formation. On the other hand, no binding at all could be detected for P56–68. This different behaviour could be related to the paracellular or transcellular route through which gluten peptides may cross the intestinal epithelium, and open new insights into the pathogenetic mechanisms of CD. Copyright © 2009 John Wiley & Sons, Ltd.
On the relationships among work characteristics and learning‐related behavior: Does age matter?
Authors: de Lange Annet H. , Taris Toon W. , Jansen Paul , Kompier Michiel A. J. , Houtman Irene L. D. , Bongers Paulien M. 
Published: September 2009

AbstractThis 3‐wave longitudinal study examined (a) the causal direction of the relationships among psychosocial work characteristics (e.g., job demands, job control, and supervisor support) and indicators of learning‐related behavior (e.g., motivation to learn and active problem solving), and (b) whether these relationships differed across age, by comparing the results for young (≤30), middle‐aged (31–44) and older (≥45) workers. The results for the total sample revealed significant reciprocal causal relationships among job demands, job control, and learning‐related behavior. Furthermore, significant age differences were found in the level of the work characteristics and learning‐related behavior, as well as in the cross‐lagged relationships among the variables. Compared to earlier—predominantly cross‐sectional—results, the present study underlines the importance of taking a dynamic as well as a life‐span view on the relationships between work and learning‐related behavior. Copyright © 2009 John Wiley & Sons, Ltd.
Multilevel knowledge and team performance
Authors: Griffith Terri L. , Sawyer John E. 
Published: September 2009

AbstractWe examined team performance as it was affected by organizationally supported face‐to‐face and technology‐mediated knowledge practices. Guided by an information processing perspective, we demonstrate from a field study of over 250 teams within a global Fortune 100 technology company that team member participation in face‐to‐face and technology‐mediated knowledge practices (e.g., community of practice (CoP) meeting attendance and use of CoP‐related technologies, respectively), and team knowledge sharing practices are positively related to individual team member knowledge. We predicted that absorptive capacity would moderate tacit knowledge relationships with team performance, and that transactive memory would moderate explicit knowledge relationships with team performance. We found that the patterns of relationships differed depending on the measure of team performance. The predictions held for absorptive capacity by tacit knowledge on manager‐assessed performance, and for transactive memory by explicit knowledge on customer satisfaction. Additionally, there was a significant direct effect, with no moderation, of tacit knowledge on customer satisfaction. We highlight multilevel modeling for team research and argue for joint consideration of organizational and technology practices. Copyright © 2009 John Wiley & Sons, Ltd.
A long‐term vegetation history of the Mojave–Colorado desert ecotone at Joshua Tree National Park
Authors: Holmgren Camille A. , Betancourt Julio L. , Rylander Kate A. 
Published: September 2009

AbstractThirty‐eight dated packrat middens were collected from upper desert (930–1357 m) elevations within Joshua Tree National Park near the ecotone between the Mojave Desert and Colorado Desert, providing a 30 ka record of vegetation change with remarkably even coverage for the last 15 ka. This record indicates that vegetation was relatively stable, which may reflect the lack of invasion by extralocal species during the late glacial and the early establishment and persistence of many desert scrub elements. Many of the species found in the modern vegetation assemblages were present by the early Holocene, as indicated by increasing Sørenson's Similarity Index values. C4 grasses and summer‐flowering annuals arrived later at Joshua Tree National Park in the early Holocene, suggesting a delayed onset of warm‐season monsoonal precipitation compared to other Sonoran Desert and Chihuahuan Desert localities to the east, where summer rains and C4 grasses persisted through the last glacial–interglacial cycle. This would suggest that contemporary flow of monsoonal moisture into eastern California is secondary to the core processes of the North American Monsoon, which remained intact throughout the late Quaternary. In the Holocene, northward displacement of the jet stream, in both summer and winter, allowed migration of the subtropical ridge as far north as southern Idaho and the advection of monsoonal moisture both westward into eastern California and northward into the southern Great Basin and Colorado Plateau. Copyright © 2009 John Wiley & Sons, Ltd.
The last 100 000 years' palaeoenvironmental changes inferred from the diatom assemblages of core MD012404 from the Okinawa Trough, East China Sea
Authors: Chang Yuan‐Pin , Wang Wei‐Lung , Chen Min‐Te 
Published: September 2009

AbstractThe diatom assemblage records preserved in a sedimentary core MD012404 retrieved from the Okinawa Trough in the East China Sea (ECS) imply palaeoenvironmental changes of the last 100 ka. Our statistical analyses of diatom species abundance data indicate that the assemblages dominate open ocean and warm water, coastal water and freshwater masses in the ECS. These proxy species were used to infer the long‐term variation in surface hydrological conditions and palaeoclimate. Cycles of ca. 23 ka observed in the relative abundance of the tychopelagic species Paralia sulcata indicate that the increases in precipitation driven by solar insolation might have controlled the diatom assemblages in the ECS. The diatom records also indicate relatively low abundances of tropical, tychopelagic and freshwater species during millennial‐scale cold events such as the Younger Dryas and Heinrich events, which have been well expressed in the high‐latitude Northern Hemisphere climate. The floral patterns are interpreted as synchronous cooling and more saline sea surface conditions in the ECS caused by the enhanced Asian winter monsoon during the Northern Hemisphere cold events. The higher abundances of tropical species during deglaciation and the Holocene might have been linked to gradual increases in the inflow of the Kuroshio into the Okinawa Trough. The records also suggest a temporary reduction in tropical species from 5 to 3 ka, corresponding to the Pulleniatina Minimum Event during which the warm‐water planktic foraminifer Pulleniatina obliquiloculata was rare. Copyright © 2009 John Wiley & Sons, Ltd.