bluuebunny/crossref_metadata_2025_split huggingface dataset:
Die Ermittlung von Bemessungswindlasten von Gebäuden im Windkanal
Authors: Visser G. Th. , Geurts Ch. , van Staalduinen P. 
Published: March 2013

AbstractDie Windlasten eines Gebäudes lassen sich anhand von Normen entwickeln. Bei diesen Normen mußten Vereinfachungen vorgenommen werden, weil es zum Beispiel nicht möglich ist, alle möglichen Gebäudeformen und ‐abmessungen in Normen aufzunehmen. Bei einer von der Norm abweichenden Gebäudeform muß dieses Gebäude zu einer Form schematisiert werden, die in der Norm beschrieben wird. Im allgemeinen führt dies zu einer konservativen Bestimmung der Bemessungswindlasten. Auch der Einfluß eines komplexen städtischen Umfelds oder eines Hochhauses in der unmittelbaren Nähe läßt sich nicht anhand der Norm errechnen. In bestimmten Fällen, wie bei zwei unmittelbar benachbartn Gebäuden, können die Windlasten höher sein als eine Norm angibt. Wenn dann anhand der Nrom vorgegangen würde, könnte dies zu einer unsicheren Konstruktion führen. In Windkanaluntersuchungen lassen sich die Wechselwirkungen sofort ermitteln. Die können dann im Entwurf mit einbezogen werden. Hier wird angegeben, wie eine solche Windkanaluntersuchung durchzuführen ist und wie die Ergebnisse zu Bemessungswindlasten verarbeitet werden können. Aus einigen hier gegebenen Beispielen geht hervor, daß die Bemessungswindlasten an Gebäuden, die nicht unmittelbar in Normen beschrieben werden oder die nur nach starker Schematisierung mit Normen berechnet werden können, sich hervorragend in Windkanaluntersuchungen ermitteln lassen. Dadurch kann die Berechnung und damit die Baukonstruktion von Gebäuden optimal vorgenommen werden.
Neue Fußgängerbrücken über Autobahnen
Authors: Gerold M. , Schmid H. 
Published: March 2013

AbstractIm Brückenbau gab es schon frühzeitig ausgereifte Holzkonstruktionen. Die Entwicklung neuer Klebverfahren ("Hetzerträger", Furnierschichthölzer, Holzwerkstoffe, blockverklebte Querschnitte) und Verbindungsmitteltechniken, die Erforschung der dynamischen Beanspruchbarkeiten von Holzbauteilen und Verbindungsmitteln, der Einsatz geschlossener Beläge sowie intelligente Montagetechniken haben dem Ingenieurholzbau immer wieder viele neue Möglichkeiten erschlossen. Auch die Harmonisierung im Zuge der Schaffung europäischer und internationaler Normen trug ganz wesentlich zum Austausch von Erfahrungen und Erkenntnissen bei. Im folgenden wird insbesondere über zwei neue Autobahnüberführungen in Holzbauweise in Südwestdeutschland berichtet, bei denen diese Erkenntnisse zum Einsatz kamen.
Vereinfachungen beim Tragfähigkeitsnachweis für Querkraft nach E DIN 1045‐1 (9/2000)
Authors: Heydel G. 
Published: March 2013

AbstractDie in DIN 1045‐1 für den Nachweis der Tragfähigkeit für Querkraft angegebenen Gleichungen werden umgeformt. Mit Beiwerten, die aus Tafeln zu entnehmen sind, wird die Berechnung einfacher und weniger fehleranfällig. Die Unterschiede in den Ergebnissen nach alter und neuer DIN 1045 werden aufgezeigt.
Vom geometrischen Denken zum statisch‐konstruktiven Ansatz im Brückenentwurf
Authors: Falter H. , Kahlow A. , Kurrer K.‐E. 
Published: March 2013

AbstractWährend die großen Brücken der Spätrenaissance Innovationen vor allem durch die Anwendung der Geometrie vermittelten, blieb die Anwendung statischer Methoden in der Konstruktion dem Barock vorbehalten. Die genauere Variation möglicher Enwurfsgeometrien, der Einrüstung, der Gründung und des Bauablaufs usw. waren nunmehr durch zeichnerische Vorwegnahme, zunehmende Maßhaltigkeit und Exaktheit der Entwürfe möglich. Am Beispiel des Ponte Trinità in Florenz und der Fleischbrücke in Nürnberg wird gezeigt, wie diese neue Entwurfshaltung allmählich in den Brückenbau einzog. In den ersten Dezennien des 18. Jahrhunderts avancierte der Brückenbau dann über die Zwischenstufen erster Quantifizierungsversuche zum bevorzugten Objektbereich der Gewölbetheorie. Der Gedanke der Stützlinie tritt mittelbar ins Zentrum aller Überlegungen: Konzeptionelle Entwürfe zum Funktionsmechanismus von Brücken und intensive Fachkommunikation treiben die Theoretisierung des Brückenbaues voran.
Zur Kurzzeitstandsicherheit bei Baugrubenverbaukonstruktionen in weichen Böden
Authors: Hettler A. , Leibnitz St. , Biehl F. 
Published: March 2013

AbstractIn vielen Fällen sind bei Baugrubenverbaukonstruktionen in weichen Böden dränierte Verhältnisse maßgebend. Beim Nachweis von kurzzeitigen Bauzuständen dagegen sind in der Regel undränierte Bedingungen mit der Scherfestigkeit cu vorauszusetzen. Im Beitrag wird diskutiert, wie sich der Einfluß der Schergeschwindigkeit und der Anisotropie auf die cu‐Werte aus Flügelsondierungen auswirkt. Ferner wird gezeigt, daß die Bestimmung der Einbindetiefe mit dem cu‐Konzept zu Interpretationsschwierigkeiten der Lösung führt. Deshalb empfiehlt der Arbeitskreis Baugruben, mit Ersatzreibungswinkeln zu dimensionieren.
Neue Erfahrungen mit der KEM
Authors: Linneweber D. , Niemunis A. , Triantafyllidis Th. 
Published: March 2013

AbstractDie kinematische Elementmethode (KEM) hat sich als ein Standardverfahren zur Berechnung von Traglastproblemen bewährt. In diesem Beitrag sind eigene Erfahrungen mit dieser Methode zusammengefaßt worden. Es werden Hinweise und Verbesserungsvorschläge angegeben, welche die Lösbarkeit des Optimierungsproblems erleichtern. In diesem Zusammenhang wird die Bedeutung der Dilatanz im Rahmen des Optimierungsverfahrens hervorgehoben und auf mögliche Fehler bei der bisherigen Praxis hingewiesen. Weitere Hinweise bei der Berücksichtigung von Ankern bei der KEM sind angegeben, wobei die Vorgaben der DIN 4084‐100 kritisch analysiert werden. In dieser Arbeit sind weitere Bemerkungen zu Verspannungseffekten, Lastannahmen und Bodenparametern zu finden, sowie kritische Anmerkungen bei der Anwendung von modernen Sicherheitskonzepten in der KEM sind angegeben.
Konzept zur Sicherstellung der Gebrauchstauglichkeit der Mubarak Pumping Station in Ägypten
Authors: Hildebrandt H. W. , Pierson R. , Schmidt R. 
Published: March 2013

AbstractDas Herzstück des Toshka‐Projekts im Süden Ägyptens ist die Mubarak Pumping Station. Obwohl das Bauwerk relativ große Abmessungen hat und ungünstige Randbedingungen im Hinblick auf Zwangsbeanspruchungen im Projektgebiet vorliegen, wurde auf die Anordnung von Bewegungsfugen verzichtet. Die Gebrauchseigenschaften des Bauwerks wurden durch die Kombination von betontechnologischen Maßnahmen und sinnvollen Mindestbewehrungen sichergestellt.
Kaimauern in Blockbauweise
Authors: Zdansky V. 
Published: March 2013

AbstractNach einer einführenden Betrachtung über den Aufbau von Ufereinfassungen in Blockbauweise wird ausführlich und mit Begründung der einzelnen Tätigkeiten ein an mehreren Hafenbaustellen erfolgreich durchgeführtes Bauverfahren beschrieben.
Multiwalled CNT‐pHEMA composite conduit for peripheral nerve repair
Authors: Arslantunali D. , Budak G. , Hasirci V. 
Published: March 2013

AbstractA nerve conduit is designed to improve peripheral nerve regeneration by providing guidance to the nerve cells. Conductivity of such guides is reported to enhance this process. In the current study, a nerve guide was constructed from poly(2‐hydroxyethyl methacrylate) (pHEMA), which was loaded with multiwalled carbon nanotubes (mwCNT) to introduce conductivity. PHEMA hydrogels were designed to have a porous structure to facilitate the transportation of the compounds needed for cell nutrition and growth and also for waste removal. We showed that when loaded with relatively high concentrations of mwCNTs (6%, w/w in hydrogels), the pHEMA guide was more conductive and more hydrophobic than pristine pHEMA hydrogel. The mechanical properties of the composites were better when they carried mwCNT. Elastic modulus of 6% mwCNT loaded pHEMA was twofold higher (0.32 ± 0.06 MPa) and similar to that of the soft tissues. Electrical conductivity was significantly improved (11.4‐fold) from 7 × 10−3 Ω−1.cm−1 (pHEMA) to 8.0 × 10−2 Ω−1.cm−1 (6% mwCNT loaded pHEMA). On application of electrical potential, the SHSY5Y neuroblastoma cells seeded on mwCNTs carrying pHEMA maintained their viability, whereas those on pure pHEMA could not, indicating that mwCNT helped conduct electricity and make them more suitable as nerve conduits. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 828–841, 2014.
Examining the formulation of emulsion electrospinning for improving the release of bioactive proteins from electrospun fibers
Authors: Briggs Tonye , Arinzeh Treena Livingston 
Published: March 2013

AbstractEmulsion electrospinning has been sought as a method to prepare fibrous materials/scaffolds for growth factor delivery. Emulsion conditions, specifically sonication and the addition of a surfactant, were evaluated to determine their effect on the release and bioactivity of proteins from electrospun scaffolds. Polycaprolactone (PCL) and poly(ethylene oxide) (PEO/PCL) blends were evaluated where PEO, a hydrophilic polymer, was shown to enhance the incorporation of proteins. Electrospun scaffolds prepared with the addition of the nonionic surfactant Span® 80 at a concentration greater than the critical micelle concentration followed by mild sonication (10% amplitude) released lysozyme, the model protein, with a higher level of bioactivity as compared with other surfactant and sonication conditions. These conditions were then used to prepare emulsions of platelet‐derived growth factor‐BB (PDGF‐BB) in PEO/PCL blends. Electrospun mats prepared by emulsions consisting of PDGF‐BB incorporated with Span® 80 and sonicated at 10% amplitude exhibited a controlled release of PDGF‐BB over 96 h as compared with a more rapid release from solutions that were not emulsified (Direct Addition) or emulsions that did not receive Span® 80 or sonication. Bioactive PDGF‐BB incorporated in electrospun scaffolds enhanced the osteogenic differentiation of human mesenchymal stem cells as evidenced by increased alkaline phosphatase activity, improved cell attachment and reorganized cytoskeletal filaments. The findings in this study provide improved methods for achieving controlled release of bioactive proteins from electrospun materials. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 674–684, 2014.
Alternating block polyurethanes based on PCL and PEG as potential nerve regeneration materials
Authors: Li Guangyao , Li Dandan , Niu Yuqing , He Tao , Chen Kevin C. , Xu Kaitian 
Published: March 2013

AbstractPolyurethanes with regular and controlled block arrangement, i.e., alternating block polyurethanes (abbreviated as PUCL‐alt‐PEG) based on poly(ε‐caprolactone) (PCL‐diol) and poly(ethylene glycol) (PEG) was prepared via selectively coupling reaction between PCL‐diol and diisocyanate end‐capped PEG. Chemical structure, molecular weight, distribution, and thermal properties were systematically characterized by FTIR, 1H NMR, GPC, DSC, and TGA. Hydrophilicity was studied by static contact angle of H2O and CH2I2. Film surface was observed by scanning electron microscope (SEM) and atomic force microscopy, and mechanical properties were assessed by universal test machine. Results show that alternating block polyurethanes give higher crystal degree, higher mechanical properties, and more hydrophilic and rougher (deep ravine) surface than their random counterpart, due to regular and controlled structure. Platelet adhesion illustrated that PUCL‐alt‐PEG has better hemocompatibility and the hemacompatibility was affected significantly by PEG content. Excellent hemocompatibility was obtained with high PEG content. CCK‐8 assay and SEM observation revealed much better cell compatibility of fibroblast L929 and rat glial cells on the alternating block polyurethanes than that on random counterpart. Alternating block polyurethane PUC20‐a‐E4 with optimized composition, mechanical, surface properties, hemacompatibility, and highest cell growth and proliferation was achieved for potential use in nerve regeneration. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 685–697, 2014.
AKT primes snail‐induced EMT concomitantly with the collective migration of squamous cell carcinoma cells
Authors: Okui Gaku , Tobiume Kei , Rizqiawan Andra , Yamamoto Kazuhiro , Shigeishi Hideo , Ono Shigehiro , Higashikawa Koichiro , Kamata Nobuyuki 
Published: March 2013

AbstractIn this study, we found that wounding of a confluent monolayer of squamous cell carcinoma (SCC) cells induced epithelial–mesenchymal transition (EMT) specifically at the edge of the wound. This process required the combined stimulation of TGFβ, TNFα, and PDGF‐D. Such a combined cytokine treatment of confluent monolayers of the cells upregulated the expression levels of Snail and Slug via PI3K. The PI3K downstream effector, AKT, was dispensable for the upregulation of Snail and Slug, but essential for enabling EMT in response to upregulation of Snail and Slug. J. Cell. Biochem. 114: 2039–2049, 2013. © 2013 Wiley Periodicals, Inc.
Tanshinone IIA inhibits breast cancer stem cells growth in vitro and in vivo through attenuation of IL‐6/STAT3/NF‐kB signaling pathways
Authors: Lin Caiyu , Wang Li , Wang Hong , Yang Liuqi , Guo Huijie , Wang Xiujie 
Published: March 2013

AbstractCancer stem cells (CSCs) are maintained by inflammatory cytokines and signaling pathways. Tanshinone IIA (Tan‐IIA) possesses anti‐cancer and anti‐inflammatory activities. The purpose of this study is to confirm the growth inhibition effect of Tan‐IIA on human breast CSCs growth in vitro and in vivo and to explore the possible mechanism of its activity. Human breast CSCs were enriched and expanded under serum‐free mammosphere culture condition, and identified through mammosphere formation, toluidine blue staining, immunofluorescence staining, and flow cytometry analysis of stemness markers of CD44/CD24 and ALDH, and tumorigenecity in vivo; the growth inhibition effect of Tan‐IIA on human breast CSCs in vitro were tested by cell proliferation and mammosphere formation assays; inflammatory signaling pathway related protein expression in response to Tan‐IIA, IL‐6, STAT3, phospho‐STAT3 (Tyr705), NF‐κBp65 in cytoplasm and nucleus and cyclin D1 were evaluated with Western blotting; the growth inhibition effect of Tan‐IIA on human breast CSCs growth were tested in vivo. A useful model of human breast CSCs for researching and developing the agents targeting CSCs was established. After Tan‐IIA treatment, cell proliferation and mammosphere formation of CSCs were decreased significantly; the expression levels of IL‐6, STAT3, phospho‐STAT3 (Tyr705), NF‐κBp65 in nucleus and cyclin D1 proteins were decreased significantly; the tumor growth and mean tumor weight were reduced significantly. Tan‐IIA has the potential to target and kill CSCs, and can inhibit human breast CSCs growth both in vitro and in vivo through attenuation of IL‐6/STAT3/NF‐kB signaling pathways. J. Cell. Biochem. 114: 2061–2070, 2013. © 2013 Wiley Periodicals, Inc.
SOCS‐1/3 participation in FGF‐2 signaling to modulate RANK ligand expression in paget's disease of bone
Authors: Sundaram Kumaran , Senn Joseph , Reddy Sakamuri V. 
Published: March 2013

ABSTRACTPaget's disease of bone (PDB) is a chronic focal skeletal disorder characterized by excessive bone resorption followed by disorganized new bone formation. Measles virus nucleocapsid (MVNP) is implicated in pathogenesis of PDB. RANK ligand (RANKL), a critical osteoclastogenic factor expressed on bone marrow stromal/preosteoblast cells is upregulated in PDB. We recently demonstrated that fibroblast growth factor‐2 (FGF‐2) which induces RANKL expression is elevated in PDB. In this study, we hypothesized that FGF‐2 modulates suppressors of cytokine signaling (SOCS) to induce RANKL expression in PDB. We identified increased levels of SOCS‐1/3 mRNA expression in bone marrow mononuclear cells derived from patients with PDB compared to normal subjects. Interestingly, conditioned media obtained from MVNP transduced osteoclast progenitor cells significantly increased SOCS‐1/3 mRNA expression in stromal/preosteoblast cells. We next examined if SOCS participates in FGF‐2 signaling to modulate RANKL gene expression. We showed that FGF‐2 stimulation significantly increased SOCS‐1/3 expression in human bone marrow stromal/preosteoblast cells. In addition, co‐expression of SOCS‐1/3 with hRANKL gene promoter‐luciferase reporter plasmid in marrow stromal cells demonstrated a significant increase in promoter activity without FGF‐2 stimulation. Furthermore, siRNA inhibition of STAT‐1 suppresses FGF‐2 increased SOCS‐1/3 expression in these cells. Thus, our results suggest that SOCS participates in FGF‐2 modulation of RANKL expression in PDB. J. Cell. Biochem. 114: 2032–2038, 2013. © 2013 Wiley Periodicals, Inc.
MicroRNA miR‐24 promotes cell proliferation by targeting the CDKs inhibitors p27Kip1 and p16INK4a
Authors: Giglio Simona , Cirombella Roberto , Amodeo Rachele , Portaro Luciano , Lavra Luca , Vecchione Andrea 
Published: March 2013

AbstractCell cycle progression is controlled by numerous mechanisms ensuring correct cell division. The transition from one cell cycle phase to another occurs in an orderly fashion and is regulated by different cellular proteins. Therefore an alteration of the regulatory mechanisms of the cell cycle results in uncontrolled cell proliferation, which is a distinctive feature of human cancers. Recent evidences suggest that microRNAs (miRs) may also control the levels of multiple cell cycle regulators and therefore control cell proliferation. In fact miRs are a class of small non‐coding RNAs, which modulate gene expression. They are involved in numerous physiological cellular processes and most importantly accumulating evidence indicates that many miRs are aberrantly expressed in human cancers. In this report we describe that miR‐24 directly targets p27Kip1 and p16Ink4a in primary keratinocyte and in different cancer derived cell lines promoting their proliferation, suggesting that miR‐24 is involved in cyclin‐dependent kinase inhibitors post‐transcriptional regulation and that upregulation of miR‐24 may play a role in carcinogenesis. J. Cell. Physiol. 228: 2015–2023, 2013. © 2013 Wiley Periodicals, Inc.
Changes in hospitals' credentialing requirements for board certification from 2005 to 2010
Authors: Freed Gary L. , Dunham Kelly M. , Gebremariam Acham 
Published: March 2013

OBJECTIVEIn 2005, we conducted a study of the prevalence of board certification requirements for hospital privileging and found that one‐third of hospitals did not require pediatricians to be board certified. In 2010, the American Board of Pediatrics implemented the Maintenance of Certification (MOC) program. To examine changes in the policies of hospitals regarding requirements for board certification, we surveyed privileging personnel at hospitals across the country.STUDY DESIGNTelephone survey between April 2010 and June 2010 of privileging personnel at a random sample of 220 hospitals.RESULTSOf the 220 hospitals, 23 were ineligible because they had no pediatricians on staff, and 26 hospitals refused to participate. The remaining 154 hospitals completed the survey, resulting in a 78% participation rate. Compared with our findings in 2005, in 2010 a greater proportion of hospitals now require board certification for general pediatricians (80% vs 67%, P = 0.141) and pediatric subspecialists (86% vs 71%, P = 0.048). Among these hospitals, a larger proportion (24% vs 4%) now requires board certification for all pediatricians at the point of initial privileging. However, a greater proportion of hospitals reported that they make exceptions to their board certification policies (99% vs 41%).CONCLUSIONIn the 5 years since our previous study, a larger proportion of hospitals now require pediatricians to be board certified, although the proportion of hospitals that make exceptions to this policy has increased twofold. Hospitals appear to be incorporating the MOC program into their privileging policies. Journal of Hospital Medicine 2013;8:298–303. © 2013 Society of Hospital Medicine
Granulocytes of reptilian sauropsids contain beta‐defensin‐like peptides: A comparative ultrastructural survey
Authors: Alibardi Lorenzo 
Published: March 2013

ABSTRACTThe ability of lizards to withstand infections after wounding or amputation of the tail or limbs has suggested the presence of antimicrobial peptides in their tissues. Previous studies on the lizard Anolis carolinensis have identified several beta‐defensin‐like peptides that may potentially be involved in protection from infections. The present ultrastructural immunocytochemical study has analyzed tissues in different reptilian species in order to localize the cellular source of one of the more expressed beta‐defensins previously sequenced in lizard indicated as AcBD15. Beta‐defensin‐like immunoreactivity is present in some of the larger, nonspecific granules of granulocytes in two lizard species, a snake, the tuatara, and a turtle. The ultrastructural study indicates that only heterophilic and basophilic granulocytes contain this defensin while other cell types from the epidermis, mesenchyme, and dermis, muscles, nerves, cartilage or bone are immunonegative. The study further indicates that not all granules in reptilian granulocytes contain the beta‐defensin peptide, suggesting the presence of granules with different content as previously indicated for mammalian neutrophilic leucocytes. No immunolabeling was instead observed in granulocytes of the alligator and chick using this antibody. The present immunocytochemical observations suggest a broad cross‐reactivity and conservation of beta‐defensin‐like sequence or steric motif across lepidosaurians and likely in turtles while archosaurian granulocytes may contain different beta‐defensin‐like or other peptides. J. Morphol. 274:877–886, 2013. © 2013 Wiley Periodicals, Inc.
Noninvasive assessment of osteoarthritis severity in human explants by multicontrast MRI
Authors: Griebel Adam J. , Trippel Stephen B. , Emery Nancy C. , Neu Corey P. 
Published: March 2013

PurposeMedical imaging has the potential to noninvasively diagnose early disease onset and monitor the success of repair therapies. Unfortunately, few reliable imaging biomarkers exist to detect cartilage diseases before advanced degeneration in the tissue.MethodIn this study, we quantified the ability to detect osteoarthritis (OA) severity in human cartilage explants using a multicontrast magnetic resonance imaging (MRI) approach, inclusive of novel displacements under applied loading by MRI, relaxivity measures, and standard MRI.ResultsDisplacements under applied loading by MRI measures, which characterized the spatial micromechanical environment by 2D finite and Von Mises strains, were strong predictors of histologically assessed OA severity, both before and after controlling for factors, e.g., patient, joint region, and morphology. Relaxivity measures, sensitive to local macromolecular weight and composition, including T1ρ, but not T1 or T2, were predictors of OA severity. A combined multicontrast approach that exploited spatial variations in tissue biomechanics and extracellular matrix structure yielded the strongest relationships to OA severity.ConclusionOur results indicate that combining multiple MRI‐based biomarkers has high potential for the noninvasive measurement of OA severity and the evaluation of potential therapeutic agents used in the treatment of early OA in animal and human trials. Magn Reson Med 71:807–814, 2014. © 2013 Wiley Periodicals, Inc.