Home About us Contact
|
Home About us Contact | ||
|
|
||
Lining
Kinds of Lining Terms modified by Lining Selected AbstractsRead Lining: UHD9 RenovationJOURNAL OF ARCHITECTURAL EDUCATION, Issue 2 2003MARC SWACKHAMER For a University of Houston downtown (UHD) campus renovation, the school's administration asked us to convert the entire ninth floor of a 1929 cotton warehouse into executive administrative offices, including those of the president, vice president, provost, and human resources department. In response to this task, we posed two primary questions: How can we combine "high-end" and "low-end" materials to alter typical expectations of how a university administrative office should and should not appear? How can we challenge assumed differences between use and appearance, part and whole,and, ultimately, between student and administrator,to produce a space that suspends hierarchical preconceptions and produces a more open "etiquette" for dialogue? [source] Biomechanical Strength of Human Nasal Septal Lining: Comparison of the Constituent LayersTHE LARYNGOSCOPE, Issue 8 2005David W. Kim MD Abstract Objective/Hypothesis: Nasal septal perforation is a common complication following surgery involving the nasal septum. Septoplasty, septorhinoplasty, and submucosal resection may result in the inadvertent resection of perichondrium, which may predispose the patient to septal perforations. Study Design: Controlled human cadaver study testing the biomechanical strength of the constituent layers of nasal septal lining. Methods: Uniform samples of nasal septal mucosa, perichondrium, and a composite of both layers were obtained from five fresh human cadavers. The mechanical tensile strength of these layers was evaluated and compared with the Instron 4301 Mechanical Testing System (Canton, MA). Results: Mixed-effects regression analysis demonstrated a significant difference in the tensile strength of the three groups (mean values ± SD: mucosa, 662 ± 308 g; perichondrium, 1370 ± 798 g; composite, 2340 ± 1252 g). All three pairwise comparisons among the three groups showed a significant difference in tensile strength. Conclusion: The perichondrial layer imparts the majority of the biomechanical strength to septal lining. Lining flaps containing both perichondrium and mucosa are stronger than flaps with either perichondrium or mucosa alone. Dissection in the subperichondrial plane during septal surgery provides a stronger septal flap and may prevent the development of nasal septal perforation during nasal surgery. [source] Pulsatile Ventricular Assist Device with Pericardial Inner LiningARTIFICIAL ORGANS, Issue 11 2001Adolfo A. Leirner Abstract: Preserved pericardium in contact with blood is not thrombogenic, therefore avoiding the use of anticoagulants, and has excellent mechanical properties. Our objective is to take advantage of these characteristics and build a pulsatile ventricular assist device (VAD) with pericardium used as the inner lining of the blood chamber. A mold is used for the tanning of the pericardium, rendering it with an exact shape. A flexible polymeric structure is designed to serve as a base for the pericardium, guiding it and limiting its rate of strain. It consists of two halves, which when outfitted with the interior pericardium lining and connected to each other, form the blood chamber. This assembly is housed in rigid polyvinyl chloride (PVC) shells making up the air chamber for the pneumatic activation. Valves are likewise made of pericardium. Sealing of the chambers was tested statically up to 300 mm Hg with no air or fluid leakage. The device was tested for 60 continuous days in a mock loop, demonstrating hydrodynamic performance adequate for ventricular assist. Micrographs (confocal laser and scanning electron microscopy) were obtained of several pericardium areas, especially on the flexing regions that are a transition between the wet and dry regions. No sign of damage to the pericardium was observed either with the naked eye or at the microscopic level. From the hydraulic performance and materials viewpoints, a completely pericardium-lined pulsatile VAD displaying a polymeric structure that avoids unpredictable bending and limits strain is feasible. The results warrant further studies regarding biocompatibility and strength advantages. [source] Corrosion Books: Corrosion-Resistant Linings and Coatings.MATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 1 2007By: Philip A. Schweitzer [source] Anwendung der neuen Stahlbetonnormen für die Bemessung von TunnelinnenschalenBETON- UND STAHLBETONBAU, Issue 2 2004Bruno Mattle Dipl.-Ing. Abstract Die in den letzten Jahren in der Bundesrepublik Deutschland und in Österreich errichteten Verkehrstunnel wurden i. a. zweischalig, d. h. mit einer Spritzbetonaußenschale und einer Innenschale aus unbewehrtem Beton oder Stahlbeton hergestellt. Die Bemessung der Innenschalen erfolgte unter Anwendung der Normen DIN 1045 [1] und ÖN B 4200 [2]. Während die neuen Normen wie EC 2 [3], DIN 1045-1 [4] und ÖN B 4700 [5] im Hochbau schon seit längerem Anwendung finden, ist deren Anwendung für die Bemessung von Tunnelschalen im wesentlichen noch Neuland. Dies betrifft insbesondere die Anwendung des Teilsicherheitskonzeptes und die Möglichkeit, die Schnittgrößen unter Anwendung nichtlinearer Stoffgesetze zu ermitteln. Im vorliegenden Beitrag wird die Problematik dargestellt und anhand von Beispielen der Einfluß unterschiedlicher Annahmen aufgezeigt. Design of Final Tunnel Linings according to the new Codes for Reinforced Concrete The traffic tunnels which have been constructed during the last few years in Germany and Austria in general have an initial shotcrete lining and a final, cast in place reinforced or unreinforced concrete lining. The structural design of the final linings has been based on specific standards from the clients and on the national codes DIN 1045 [1] and ÖN B 4200 [2]. While the new codes EC 2 [3], DIN 1045-1 [4] and ÖN B 4200 [5] have been widely used for the structural design of buildings for a while, their application for the design of tunnel linings is more or less a new field. In particular this is valid for using nonlinear material laws and the partial safety factor concept. In the presented paper this topic is discussed and the consequences of different assumptions are shown on specific examples. [source] Dexamethasone alters F-actin architecture and promotes cross-linked actin network formation in human trabecular meshwork tissueCYTOSKELETON, Issue 2 2005Abbot F. Clark Abstract Elevated intraocular pressure is an important risk factor for the development of glaucoma, a leading cause of irreversible blindness. This ocular hypertension is due to increased hydrodynamic resistance to the drainage of aqueous humor through specialized outflow tissues, including the trabecular meshwork (TM) and the endothelial lining of Schlemm's canal. We know that glucocorticoid therapy can cause increased outflow resistance and glaucoma in susceptible individuals, that the cytoskeleton helps regulate aqueous outflow resistance, and that glucocorticoid treatment alters the actin cytoskeleton of cultured TM cells. Our purpose was to characterize the actin cytoskeleton of cells in outflow pathway tissues in situ, to characterize changes in the cytoskeleton due to dexamethasone treatment in situ, and to compare these with changes observed in cell culture. Human ocular anterior segments were perfused with or without 10,7 M dexamethasone, and F-actin architecture was investigated by confocal laser scanning microscopy. We found that outflow pathway cells contained stress fibers, peripheral actin staining, and occasional actin "tangles." Dexamethasone treatment caused elevated IOP in several eyes and increased overall actin staining, with more actin tangles and the formation of cross-linked actin networks (CLANs). The actin architecture in TM tissues was remarkably similar to that seen in cultured TM cells. Although CLANs have been reported previously in cultured cells, this is the first report of CLANs in tissue. These cytoskeletal changes may be associated with increased aqueous humor outflow resistance after ocular glucocorticoid treatment. Cell Motil. Cytoskeleton 60:83,95, 2005. © 2004 Wiley-Liss, Inc. [source] Alar Reconstruction with Subcutaneous Pedicled Nasolabial Flap: Difficulties, Considerations, and Conclusions for This ProcedureDERMATOLOGIC SURGERY, Issue 10 2005Fumiya Iwao MD Background. The subcutaneous pedicled nasolabial flap is a useful material for alar reconstruction. Objective. This article describes the difficulties and considerations in this procedure and discusses the procedural problems involved, drawing conclusions from them. Methods. Case 1: a folded flap was used with a conchal cartilage strut sandwich. Case 2: only a folded flap was used. Case 3: the flap was used to cover the outer surface of the ala, and a mucoperiosteal graft from the hard palate was used for the ala lining. Results. The cartilage strut was not sufficient to support the shape of the ala in case 1. Harvesting a sufficiently wide flap is thought to be important. However, a folded flap had some drawbacks, with the formation of a thick alar rim. Conclusions. The combination of a flap for the outer surface and a mucoperiosteal graft as a lining is thought to be an excellent option for alar reconstruction. [source] Endoderm development in vertebrates: fate mapping, induction and regional specificationDEVELOPMENT GROWTH & DIFFERENTIATION, Issue 6 2005Kimiko Fukuda The formation of the vertebrate body plan begins with the differentiation of cells into three germ layers: ectoderm, mesoderm and endoderm. Cells in the endoderm give rise to the epithelial lining of the digestive tract, associated glands and respiratory system. One of the fundamental problems in developmental biology is to elucidate how these three primary germ layers are established from the homologous population of cells in the early blastomere. To address this question, ectoderm and mesoderm development have been extensively analyzed, but study of endoderm development has only begun relatively recently. In this review, we focus on the ,where', ,when' and ,how' of endoderm development in four vertebrate model organisms: the zebrafish, Xenopus, chick and mouse. We discuss the classical fate mapping of the endoderm and the more recent progress in characterizing its induction, segregation and regional specification. [source] Sealing ability of occlusal resin composite restoration using four restorative proceduresEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 6 2008Danuchit Banomyong The purpose of this work was to investigate fluid flow after restoration using four restorative procedures. Micro-gap, internal dye leakage, and micropermeability of bonded interfaces were also investigated. Each tooth was mounted, connected to a fluid flow-measuring device, and an occlusal cavity was prepared. Fluid flow after cavity preparation was recorded as the baseline measurement, and the cavity was restored using one of four restorative procedures: bonding with total-etch (Single Bond 2) or self-etch (Clearfil SE Bond) adhesives without lining; or lining with resin-modified glass-ionomer cement (GIC) (Fuji Lining LC) or conventional GIC (Fuji IX) and then bonding with the total-etch adhesive. Fluid flow was recorded after restoration and at specific time-points up to 6 months thereafter and recorded as a percentage. Micro-gap formation was analyzed using resin replicas and scanning electron microscopy. Internal leakage of 2% methylene blue dye was observed under a light microscope. In micro-permeability testing, fluorescent-dye penetration was investigated using confocal laser microscopy. None of the restorative procedures provided a perfectly sealed restoration. Glass-ionomer lining did not reduce fluid flow after restoration, and micro-gaps were frequently detected. The self-etch adhesive failed to provide a better seal than the total-etch adhesive, and even initial gap formation was rarely observed for the former. Penetration of methylene blue and fluorescent dyes was detected in most restorations. [source] The origin of the endothelial cells: an evo-devo approach for the invertebrate/vertebrate transition of the circulatory systemEVOLUTION AND DEVELOPMENT, Issue 4 2005R. Muñoz-Chápuli Summary Circulatory systems of vertebrate and invertebrate metazoans are very different. Large vessels of invertebrates are constituted of spaces and lacunae located between the basement membranes of endodermal and mesodermal epithelia, and they lack an endothelial lining. Myoepithelial differentation of the coelomic cells covering hemal spaces is a frequent event, and myoepithelial cells often form microvessels in some large invertebrates. There is no phylogenetic theory about the origin of the endothelial cells in vertebrates. We herein propose that endothelial cells originated from a type of specialized blood cells, called amoebocytes, that adhere to the vascular basement membrane. The transition between amoebocytes and endothelium involved the acquisition of an epithelial phenotype. We suggest that immunological cooperation was the earliest function of these protoendothelial cells. Furthermore, their ability to transiently recover the migratory, invasive phenotype of amoebocytes (i.e., the angiogenic phenotype) allowed for vascular growth from the original visceral areas to the well-developed somatic areas of vertebrates (especially the tail, head, and neural tube). We also hypothesize that pericytes and smooth muscle cells derived from myoepithelial cells detached from the coelomic lining. As the origin of blood cells in invertebrates is probably coelomic, our hypothesis relates the origin of all the elements of the circulatory system with the coelomic wall. We have collected from the literature a number of comparative and developmental data supporting our hypothesis, for example the localization of the vascular endothelial growth factor receptor-2 ortholog in hemocytes of Drosophila or the fact that circulating progenitors can differentiate into endothelial cells even in adult vertebrates. [source] Isolation of a Carnobacterium maltaromaticum- like bacterium from systemically infected lake whitefish (Coregonus clupeaformis)FEMS MICROBIOLOGY LETTERS, Issue 1 2008Thomas P. Loch Abstract Herein we report on the first isolation of a Carnobacterium maltaromaticum -like bacterium from kidneys and swim bladders of lake whitefish (Coregonus clupeaformis) caught from Lakes Michigan and Huron, Michigan. Isolates were Gram-positive, nonmotile, facultatively anaerobic, asporogenous rods that did not produce catalase, cytochrome oxidase, or H2S, and did not grow on acetate agar. Except for carbohydrate fermentation, many phenotypic characteristics of lake whitefish isolates coincided with those of C. maltaromaticum, the causative agent of pseudokidney disease. Partial sequencing of 16S and 23S rRNA genes, as well as the piscicolin 126 precursor gene, yielded 97% and 98% nucleotide matches with C. maltaromaticum, respectively (accession numbers EU546836 and EU546837; EU643471). Phylogenetic analyses showed that lake whitefish isolates of this study are highly related, yet not fully identical to C. maltaromaticum. The presence of the C. maltaromaticum -like bacterium was associated with splenomegaly, renal and splenic congestion, and thickening of the swim bladder wall with accumulation of a mucoid exudate. Examination of stained tissue sections revealed renal and splenic congestion, vacuolation and bile stasis within the liver, and hyperplasia within the epithelial lining of the swim bladder. The concurrent presence of pathological changes and the C. maltaromaticum -like bacteria suggests that this bacterium is pathogenic to lake whitefish. [source] Thermal properties of gypsum plasterboard at high temperaturesFIRE AND MATERIALS, Issue 1 2002Geoff Thomas Light timber frame wall and floor assemblies typically use gypsum-based boards as a lining to provide fire resistance. In order to model the thermal behaviour of such assemblies, the thermo-physical properties of gypsum plasterboard must be determined. The relevant literature and the chemistry of the two consecutive endothermic dehydration reactions that gypsum undergoes when heated are reviewed. The values determined for the thermo-physical properties are modified to create smooth enthalpy and thermal conductivity curves suitable for input into a finite element heat transfer model. These values are calibrated within a reasonable range and then validated using furnace and fire test data. The type of plasterboard used in these tests is an engineered product similar to the North American type C board. The temperature at which the second dehydration reaction occurs is altered to be consistent with later research with little apparent affect on the comparison with test results. Values for specific heat, mass loss rates and thermal conductivity for gypsum plasterboard that are suitable for use in finite element heat transfer modelling of light timber frame wall and floor assemblies are recommended. Copyright © 2002 John Wiley & Sons, Ltd. [source] Possible role of exogenous cAMP to improve vascular endothelial dysfunction in hypertensive ratsFUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 6 2006Dhvanit I. Shah Abstract The study has been designed to investigate the effect of 8-Br-cAMP, an activator of protein kinase A, in hypertension-induced vascular endothelial dysfunction. Rats were uninephroctomized and desoxycortisone acetate (DOCA) (40 mg/kg, s.c.) was administered to rats to produce hypertension (mean arterial blood pressure > 140 mmHg). Vascular endothelial dysfunction was assessed using isolated aortic ring preparation, electron microscopy of thoracic aorta and serum concentration of nitrite/nitrate. The expression of mRNA for p22phox and eNOS was assessed by using reverse transcriptase-polymerase chain reaction. Serum thiobarbituric acid reactive substances concentration and aortic superoxide anion concentration were estimated to assess oxidative stress. 8-Br-cAMP (5 mg/kg, i.p.) or atorvastatin (30 mg/kg, p.o.) prevented hypertension-induced attenuation of acetylcholine-induced endothelium-dependent relaxation, impairment of vascular endothelial lining, decrease in expression of mRNA for endothelial nitric oxide synthase (eNOS), serum nitrite/nitrate concentration and increase in expression of mRNA for p22phox, superoxide anion and serum TBARS. The ameliorative effect of 8-Br-cAMP was prevented by N -nitro- l -arginine methyl ester (25 mg/kg, i.p.) and glibenclamide (30 mg/kg, i.p.). It may be concluded that 8-Br-cAMP may stimulate expression and activity of eNOS and suppress expression of p22phox subunit of NADPH oxidase to reduce oxidative stress and subsequently improve vascular endothelial dysfunction. [source] The interaction of ground, TBM and segment lining with closed shield machines / . Interaktion Untergrund, Tunnelvortriebsmaschine und Tübbingausbau bei geschlossenen SchildmaschinenGEOMECHANICS AND TUNNELLING, Issue 5 2010Dipl.-Ing. Mechanised tunnelling - Maschineller Vortrieb Abstract The article explains the interaction of the overall system of ground, TBM and segment lining based on recent experience of projects using TBMs with active face support in Austria and abroad. The alternating dependencies and their consequences for tunnel construction are discussed in more detail. Of particular interest is the influence of the support medium and how it functions at the face and the tunnel side walls. The interaction of support pressure, thrust force and the centre of gravity of the TBM and its effect on steering behaviour are also considered. The effects of the compression of the segment tube by the TBM (prestress) are considered in relation to the improvement of the bedding and the problem of floating. Der Beitrag beleuchtet die Interaktion des Gesamtsystems "Untergrund , Tunnelvortriebsmaschine , Tübbingausbau" basierend auf aktuellen Erfahrungen zuletzt realisierter Projekte im In- und Ausland bei TVM-Einsätzen mit aktiver Ortsbruststützung. Dabei wird insbesondere auf die wechselweisen Abhängigkeiten und deren Auswirkungen auf die Tunnelherstellung eingegangen. Ein Schwerpunkt liegt beim Einfluss des Stützmediums und der zugehörigen Wirkungsweise an der Ortsbrust und der Tunnellaibung. Berücksichtigung findet die Wechselwirkung von Stützdruck, Vortriebskraft und der Schwerpunktlage der TVM auf deren Steuerverhalten. Die Auswirkung des Zusammendrückens der Tübbingröhre durch die TVM (Vorspannung) wird in Bezug auf die Bettungsverbesserung und die Problematik des Aufschwimmens betrachtet. [source] Design approach for the hybrid underground station at Union Suare/Market Street in San Francisco.GEOMECHANICS AND TUNNELLING, Issue 4 2009Entwurfskonzept für eine hybride U-Bahnstation Union Square/Market Street in San Francisco Abstract The new Central Subway extension through downtown San Francisco consists of three underground stations and 2.7 km TBMdriven twin tunnel. This paper provides a description of the preliminary analyses and design of the ground support and final lining for the Union Square\Market Street Station (UMS) along Stockton Street. This station will serve the Union Square Shopping District and connect to the BART Powell Street Station. Due to shortage of space above ground and to minimize surface disruption, the UMS station design requires a complex hybrid method consisting of a 20 m deep braced cut-and-cover box with a mined enlargement bulb below it with a height of 9.3 m and a width of 17.8 m. The majority of the UMS station will be excavated in saturated alluvial deposits. Undifferentiated old bay deposits will be encountered in the invert, underlain by dense marine sands. The groundwater varies from 5 to 10 m below ground level, so uplift of the combined bulb/box structure has to be taken into account. The Finite Element (FE) analysis of the UMS station cavern reflects the separate construction phases of the station platform box and the bulb to account for soil-structure interaction and load-sharing effects. FE analyses are used to estimate support requirements including ground improvement and to predict surface settlements. Die Erweiterung der Central Subway durch die Innenstadt von San Francisco beinhaltet drei Stationsbauwerke und 2,7 km maschinell vorgetriebene Doppelröhrentunnel. In diesem Artikel erfolgt eine Beschreibung der Voruntersuchungen und Vorbemessung der Stützmaßnahmen sowie der Innenschale der Union Square\Market Street Station (UMS) im Verlauf der Stockton Street. Diese Station soll dem Union Square Shopping Distrikt dienen und zur BART Powell Street Station verbinden. Aufgrund der beengten Platzverhältnisse und zur Minimierung der Beeinträchtigung der Oberfläche ist ein "hybrides" Konzept der UMS-Station erforderlich. Dieses besteht aus einer 20 m tiefen ausgesteiften Baugrube (Box) und einer darunterliegenden bergmännisch hergestellten Kaverne (Bulb) mit 9,3 m Höhe und 17,8 m Breite. Der Großteil der UMS-Station befindet sich in gesättigten alluvialen Ablagerungen. Undifferenziert werden alte Bucht-Ablagerungen und dichte marine Sande in der Sohle vorgefunden. Der Grundwasserspiegel variiert in einer Teufe zwischen 5 bis 10 m unter der Oberfläche, aus diesem Grund ist der Auftrieb des kombinierten Bauwerks bestehend aus Bulb und Box zu berücksichtigen. In Finite Element (FE) Berechnungen der UMS-Station werden die einzelnen Bauphasen des Stationsbauwerks, sowohl von Box als auch Bulb, modelliert, um die Wechselwirkungen von Baugrund-Bauwerk und die jeweiligen Lastumlagerungen zu berücksichtigen. Mittels FE-Berechnungen werden schließlich die notwendigen Stützmaßnahmen , diese beinhalten auch Bodenverbesserungsmaßnahmen , und die Oberflächensetzungen festgelegt. [source] The influence of grout and bentonite slurry on the process of TBM tunnelling.GEOMECHANICS AND TUNNELLING, Issue 3 2009Der Einfluss von Ringspaltmörtel und Bentonitsuspension auf den TBM-Vortrieb Abstract The bentonite and grout flow around a TBM is elaborated, as well as grout flow along the lining. The calculated grout flow along the lining is compared with the results of measurements. Measurement data for the flow around the TBM are not available. Both the bentonite and the grout are modelled as a Bingham liquid and it will be shown that, due to the relatively low flow velocities, the yield stress is the governing parameter. The results of the calculations show that both the flow around the TBM and the flow around the lining may significantly influence loading on the TBM, the soil, and the lining. The bentonite and grout flow around the TBM may result in a lower volume loss than calculated when assuming that the soil follows the tapered TBM. The grout flow and especially grout consolidation lead to lower pressures around the lining if the tunnel is constructed in sandy soil. Der Bentonit- und Mörtelfluss um eine TBM und der Mörtelfluss entlang der Auskleidung werden diskutiert. Der berechnete Mörtelfluss entlang der Auskleidung wird mit Messdaten verglichen. Für die Strömungen um eine TBM existieren keine Messdaten. Sowohl der Bentonit als auch der Mörtel werden als Bingham Flüssigkeit modelliert, und es wird gezeigt, dass wegen der relativ niedrigen Strömungsgeschwindigkeiten die Fließspannung der bestimmende Parameter ist. Die Ergebnisse der Berechnungen zeigen, dass sowohl die Strömung um die TBM als auch entlang der Auskleidung einen bedeutenden Einfluss auf die Belastung der TBM, des Bodens und der Auskleidung haben. Der Bentonit- und Mörtelfluss um die TBM kann einen niedrigeren Volumenverlust zur Folge haben als berechnet, wenn man annimmt, dass der Boden der konisch zulaufenden TBM folgt. Der Mörtelfluss und besonders die Mörtelverfestigung führen zu einem niedrigeren Druck auf die Auskleidung wenn der Tunnel in sandigem Boden errichtet wird. [source] A Numerical Simulation Model for Shield Tunnelling with Compressed Air SupportGEOMECHANICS AND TUNNELLING, Issue 3 2008Felix Nagel Dipl.-Ing. This paper is concerned with a numerical simulation model (ekate) specifically designed for shield tunnelling in fully and partially saturated soils based upon the Finite Element Method (FEM). The model considers all relevant components , the soil, the lining, the tail void grouting, the hydraulic jacks and different types of face support , involved in shield tunnelling. The surrounding soft soil is formulated as a three-phase material, consisting of the soil skeleton, pore water and air. This model allows for the simulation of consolidation processes in partially saturated soils as well as of flow of compressed air often used as temporary face support during repair interventions at the cutting wheel. Despite the complexity connected with the relatively high degree of realism of the simulation model, only little effort is required from the user to establish a realistic 3D model for shield tunnelling. To this end an automatic model generator has been developed which allows for a user friendly generation of the discretized model including all components involved and to investigate variants with a minimum effort for the user. The model allows for realistic predictions of settlements and also provides information on deformations and stresses in the ground, the lining and the TBM, respectively. In addition to its use as a prognosis tool in the design process, in particular for tunnelling projects in sensitive urban areas, the model also may be used to assist the driving and steering process in mechanized tunnelling. The paper provides an overview over the main components of the model, the automatic model generator and the tri-phasic representation of the soil. A simulation of a compressed air intervention of a shield tunnel in soft soil demonstrates the applicability of the model. Ein numerisches Simulationsmodell für druckluftgestützte Schildvortriebe In diesem Beitrag wird ein Simulationsmodell basierend auf der Methode der Finiten Elemente (FEM) für die Berechnung schildvorgetriebener Tunnel in un-, voll- und teilgesättigten Böden vorgestellt. In diesem numerischen Modell werden alle beim maschinellen Tunnelbau wesentlichen Komponenten , der Boden, der Ausbau, die Schildschwanzverpressung, die Vortriebspressen sowie unterschiedliche Arten der Ortsbruststützung , wirklichkeitsnah berücksichtigt. Der Baugrund wird im Simulationsmodell als dreiphasiges Material modelliert, bestehend aus dem Korngerüst, dem Porenwasser und der Porenluft. Diese Materialformulierung für den Baugrund ermöglicht die Analyse von Konsolidierungsprozessen in teilgesättigten Böden ebenso wie von Strömungsvorgängen im Boden bei Verwendung von Druckluft als temporärer Ortsbruststützung. Druckluft wird häufig beim Wechsel von Schneidwerkzeugen eingesetzt. Ungeachtet der Komplexität des Modells, die mit der relativ wirklichkeitsnahen Abbildung des Vortriebsgeschehens verbunden ist, ist nur ein sehr geringer Aufwand für die Modellgenerierung erforderlich. Um diesen Eingabeaufwand auf ein Minimum zu reduzieren, wurde ein automatischer Modellgenerator entwickelt, der den Ingenieur bei der Eingabe unterstützt und die Untersuchung von Planungsalternativen deutlich vereinfacht. Das Modell ermöglicht wirklichkeitsnahe Prognosen von Bodenbewegungen und Beanspruchungen, wie sie für die Planung von Vortrieben insbesondere unter setzungsempfindlichen, innerstädtischen Gebieten erforderlich sind. Darüber hinaus stellt das Modell ein wertvolles Hilfsmittel bei der vortriebsbegleitenden Steuerung von Vortriebsmaschinen in Lockergestein dar. Neben den wesentlichen Komponenten des numerischen Modells, des Modellgenerators und der Dreiphasen-Formulierung für den Boden enthält der Beitrag als prototypisches Anwendungsbeispiel die Simulation einer Druckluftintervention in Lockergestein. [source] Zygomaticomaxillary buttress reconstruction of midface defects with the osteocutaneous radial forearm free flapHEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 10 2008Patricio Andrades MD Abstract Background. The purpose of this study was to evaluate morbidity, functional, and aesthetic outcomes in midface zygomaticomaxillary buttress reconstruction using the osteocutaneous radial forearm free flap (OCRFFF). Methods. A retrospective review of 24 consecutive patients that underwent midface reconstruction using the OCRFFF was performed. All patients had variable extension of maxillectomy defects that requires restoration of the zygmatico-maxillary buttress. After harvest, the OCRFFF was fixed transversely with miniplates connecting the remaining zygoma to the anterior maxilla. The orbital support was given by titanium mesh when needed that was fixed to the radial forearm bone anteriorly and placed on the remaining orbital floor posteriorly. The skin paddle was used for intraoral lining, external skin coverage, or both. The main outcome measures were flap success, donor-site morbidity, orbital, and oral complications. Facial contour, speech understandability, swallowing, oronasal separation, and socialization were also analyzed. Results. There were 6 women and 18 men, with an average age of 66 years old (range, 34,87). The resulting defects after maxillectomy were (according to the Cordeiro classification; Disa et al, Ann Plast Surg 2001;47:612,619; Santamaria and Cordeiro, J Surg Oncol 2006;94:522,531): type I (8.3%), type II (33.3%), type III (45.8%), and type IV (12.5%). There were no flap losses. Donor-site complications included partial loss of the split thickness skin graft (25%) and 1 radial bone fracture. The most significant recipient-site complications were severe ectropion (24%), dystopia (8%), and oronasal fistula (12%). All the complications occurred in patients with defects that required orbital floor reconstruction and/or cheek skin coverage. The average follow-up was 11.5 months, and over 80% of the patients had adequate swallowing, speech, and reincorporation to normal daily activities. Conclusions. The OCRFFF is an excellent alternative for midface reconstruction of the zygomaticomaxillary buttress. Complications were more common in patients who underwent resection of the orbital rim and floor (type III and IV defects) or external cheek skin. © 2008 Wiley Periodicals, Inc. Head Neck, 2008 [source] Functional reconstruction of complex lip and cheek defect with free composite anterolateral thigh flap and vascularized fascia,HEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 8 2008Yur-Ren Kuo MD Abstract Background. Extensive composite defects involving the lip and cheek present difficult reconstructive challenges. This study presents a technique using anterolateral thigh (ALT) flaps with vascularized fascia for large complex oral sphincter defect reconstruction. Methods. Fifteen patients who had undergone oral cancer ablation were enrolled in the study. The average area of intraoral lining and cheek,lip skin defects was 96.9 cm2. Upper-lip defects ranged 0% to 60%, and lower-lip defects ranged 20% to 80%. Skin and intraoral lining defects were replaced by an ALT fasciacutaneous flap. The vascularized fascia of the flap was used to provide lip suspension. Results. Flap survival was 100%. All but 1 patient had good static suspension. Nine patients had adequate oral competence without drooling, but 6 had occasional oral incontinence. All patients achieved an acceptable appearance. Conclusions. For extensive cheek,lip composite defects, ALT flap together with vascularized fascia has proven to be a useful option for functional reconstruction. © 2008 Wiley Periodicals, Inc. Head Neck 2008 [source] Total upper lip reconstruction with a free temporal scalp flap: Long-term follow-up ,HEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 7 2003Kao-Ping Chang MD Abstract Background. In men, reconstruction of large full-thickness defects of the upper lip requires both an inner layer to replace the mucosal lining and an outer hair-bearing layer. Methods. When locating the superficial temporal vessels, the design of the temporal flap is marked following the hairline needed. After meticulously dissecting the flap, it is inset and microanastomosed with the facial blood vessels. The internal mucosal layer of the flap is grafted on. During the follow-up period, the sensory recovery and motor functions are examined and recorded. Results. The postoperative courses were uneventful, and patients were satisfied with the results. One patient has a long follow-up period of 18 years. Conclusions. The free temporal scalp hair-bearing flap offers a reasonable alternative to conventional techniques in the reconstruction of large defects of the male upper lip or even a total upper lip. It is a single-staged, relatively simple method of providing hair-bearing skin to the upper lip. © 2003 Wiley Periodicals, Inc. Head Neck 25: 602,605, 2003 [source] CC531S-induced damage of the rat liver sinusoidal endothelial lining is mediated by the Fas/FasL pathwayHEPATOLOGY, Issue 5 2003Katrien Vekemans No abstract is available for this article. [source] Carcinomas arising in multilocular thymic cysts of the neck: a clinicopathological study of three casesHISTOPATHOLOGY, Issue 1 2004C A Moran Aims :,To report three cases of primary carcinoma of the neck arising in multilocular thymic cysts (MTC). Methods and results :,The patients were three men aged 47, 50 and 52 years who presented with a painless neck mass of several weeks' duration. The patients had no history of previous surgical procedures or of malignancy elsewhere. The tumours in all three patients were located on the right lateral side of the neck; all patients underwent complete surgical resection of the mass. Grossly, the tumours were cystic and measured between 20 and 30 mm in greatest diameter. Histologically, the tumours showed cyst walls lined by squamous epithelium. The cyst walls contained prominent germinal centres with lymphoid hyperplasia, cholesterol cleft granulomas, and scattered keratinized structures reminiscent of Hassall's corpuscles. In addition, a neoplastic cellular proliferation composed of round to oval cells arranged in sheets and originating from the lining of the cystic structures was present. The neoplastic cells showed moderate amounts of eosinophilic cytoplasm, round nuclei, and, in some areas, prominent nucleoli. Mitotic figures were easily found, and cellular pleomorphism was present in several areas. In two cases the tumours showed features of basaloid carcinoma of the thymus, while in one case the pattern was that of squamous cell carcinoma. Immunohistochemical studies for keratin showed a strong positive reaction in the tumour cells, while leucocyte common antigen strongly stained the lymphoid background. Follow-up information obtained in two patients showed them to be alive 6 months after initial diagnosis. One patient was lost to follow-up. Conclusion :,The cases described here represent an unusual variant of carcinoma arising in multilocular thymic cyst in the neck region. [source] History and Story: Unconventional History in Michael Ondaatje's The English Patient and James A. Michener's Tales of the South PacificHISTORY AND THEORY, Issue 4 2002Madhumalati Adhikari "Literary history" is a cross between conventional (scientific) history and pure fiction. The resulting hybrid provides access to history that the more conventional sort does not (in particular, a sense of the experiences of the historical actors, and the human meaning of historical events). This claim is demonstrated by an analysis of two novels about World War II, The English Patient by Michael Ondaatje, and Tales of the South Pacific by James Michener. These two very different novels in English are by writers themselves very different from each other, writers from different times, different social and political backgrounds, and different points of view. Their novels examine the effects of the Second World War and the events of 1942 on the human psyche, and suggest how human beings have always searched for the silver lining despite the devastation and devaluation of values. Both novels resist any kind of preaching, and yet the search for peace, balance, and kindness is constantly highlighted. The facts of scientific history are woven into the loom of their unconventional histories. The sense of infirmity created by the formal barriers of traditional history is eased, and new possibilities for historical understanding are unveiled. [source] Antibody response to influenza infection of mice: different patterns for glycoprotein and nucleocapsid antigensIMMUNOLOGY, Issue 4 2003Robert Sealy Summary Our previous studies of C57BL/6 mice intranasally infected with influenza virus (A/PR8) revealed a spike of virus-specific immunoglobulin A (IgA)-secreting antibody-forming cells (AFC) in the mediastinal lymph node (MLN) 7 days post-infection. Here we show that these AFC are directed only against viral glycoprotein, and not nucleocapsid antigens. The early IgA spike associates with a decline in glycoprotein-specific AFC during week 2 post-infection. In contrast to the glycoprotein-specific AFC, nucleocapsid-specific, IgA-secreting AFC develop gradually in the MLN and persist for more than 3 weeks post-infection. As peripheral lymph node reactions wane, the nucleocapsid-specific AFC appear as long-sustained populations in the bone marrow. Microanatomical examination of the respiratory tract in infected mice shows foci of infection established in the lung 2 days post-infection, from which virus spreads to infect the entire lining of the trachea by day 3. At this time, viral haemagglutinin can be seen within the MLN, probably on projections from infected dendritic cells. This feature disappears within a day, though viral antigen expression continues to spread throughout the respiratory tract. Total IgA- and IgG-secreting AFC appear histologically in large numbers during the first week post-infection, significantly preceding the appearance of germinal centres (revealed by peanut agglutinin staining in week 2). To explain these results, we suggest that the initial immunogenic encounter of B cells with viral antigens occurs about 3 days post-infection in the MLN, with antigens transported by dendritic cells from airway mucosa, the only site of viral replication. Viral glycoproteins expressed as integral membrane components on the surface of infected dendritic cells [probably in the absence of cognate T helper (Th) cells] promote members of expanding relevant B-cell clones to undergo an IgA switch and terminal local plasmacytoid differentiation. Anti-glycoprotein specificities are thus selectively depleted from progeny of activated B-cell clones which are channelled to participate in germinal centre formation (perhaps by cognate T helper cells when they become sufficiently frequent). One product of the germinal centre reaction is the long-sustained, bone marrow-resident population, which is accordingly rich in anti-nucleoprotein, but not anti-glycoprotein specificities. Of note, we find that AFC responses toward influenza virus and Sendai virus differ, even though viral replication is limited to the airway mucosa in each case. The response towards Sendai virus exhibits neither the early appearance of anti-glycoprotein AFC expressing IgA in draining lymph nodes, nor the subsequent relative deficit of this specificity from bone marrow AFC populations. [source] Apical surgery of a maxillary molar creating a maxillary sinus window using ultrasonics: a clinical caseINTERNATIONAL ENDODONTIC JOURNAL, Issue 11 2010B. García García B, Peñarrocha M, Peñarrocha MA, von Arx T. Apical surgery of a maxillary molar creating a maxillary sinus window using ultrasonics: a clinical case. International Endodontic Journal, 43, 1054,1061, 2010. Abstract Aim, To describe a method of carrying out apical surgery of a maxillary molar using ultrasonics to create a lateral sinus window into the maxillary sinus and an endoscope to enhance visibility during surgery. Summary, A 37-year-old female patient presented with tenderness to percussion of the maxillary second right molar. Root canal treatment had been undertaken, and the tooth restored with a metal-ceramic crown. Radiological examination revealed an apical radiolucency in close proximity to the maxillary sinus. Apical surgery of the molar was performed through the maxillary sinus, using ultrasonics for the osteotomy, creating a window in the lateral wall of the maxillary sinus. During surgery, the lining of the sinus was exposed and elevated without perforation. The root-end was resected using a round tungsten carbide drill, and the root-end cavity was prepared with ultrasonic retrotips. Root-end filling was accomplished with MTA®. An endoscope was used to examine the cut root face, the prepared cavity and the root-end filling. No intraoperative or postoperative complications were observed. At the 12-month follow-up, the tooth had no clinical signs or symptoms, and the radiograph demonstrated progressing resolution of the radiolucency. Key learning points ,,When conventional root canal retreatment cannot be performed or has failed, apical surgery may be considered, even in maxillary molars with roots in close proximity to the maxillary sinus. ,,Ultrasonic sinus window preparation allows more control and can minimize perforation of the sinus membrane when compared with conventional rotary drilling techniques. ,,The endoscope enhances visibility during endodontic surgery, thus improving the quality of the case. [source] Analytical solution of the harmonic waves diffraction by a cylindrical lined cavity in poroelastic saturated mediumINTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 5 2007Y. S. Karinski Abstract This paper presents a model for the analysis of plane waves diffraction at a cavity in an infinite homogeneous poroelastic saturated medium, lined by a lining composed of four equal segments. An elastic boundary layer is placed between the cavity lining and the infinite porous medium. The boundary layer is simulated by ,elastic boundary conditions' in which the bulk matrix stress is proportional to the relative displacement between the lining and the surrounding medium matrix boundary. In addition, fluid impermeability through the intermediate layer is assumed. For the frequencies, that differ from the pseudoresonanse frequencies, the problem was reduced to the problem of an ideal elastic medium. A closed-form analytical solution of the problem was obtained using Fourier,Bessel series, the convergence of which was proven. It was shown that the number of series terms required to obtain a desired level of accuracy can be determined in advance. The influence of the medium porosity on the medium dynamic stress concentration was studied. Copyright © 2006 John Wiley & Sons, Ltd. [source] Analysis of shield tunnelINTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 1 2004W.Q. Ding Abstract This paper proposes a two-dimensional finite element model for the analysis of shield tunnels by taking into account the construction process which is divided into four stages. The soil is assumed to behave as an elasto-plastic medium whereas the shield is simulated by beam,joint discontinuous model in which curved beam elements and joint elements are used to model the segments and joints, respectively. As grout is usually injected to fill the gap between the lining and the soil, the property parameters of the grout are chosen in such a way that they can reflect the state of the grout at each stage. Furthermore, the contact condition between the soil and lining will change with the construction stage, and therefore, different stress-releasing coefficients are used to account for the changes. To assess the accuracy that can be attained by the method in solving practical problems, the shield tunnelling in the No. 7 Subway Line Project in Osaka, Japan, is used as a case history for our study. The numerical results are compared with those measured in the field. The results presented in the paper show that the proposed numerical procedure can be used to effectively estimate the deformation, stresses and moments experienced by the surrounding soils and the concrete lining segments. The analysis and method presented in this paper can be considered to be useful for other subway construction projects involving shield tunnelling in soft soils. Copyright © 2004 John Wiley & Sons, Ltd. [source] A coupled simulation of an explosion inside a lined cavity surrounded by a plastic compressible mediumINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 10 2007V. R. Feldgun Abstract The paper develops a coupled approach to simulate an axisymmetric explosion inside a buried lined cavity. The approach allows accounting for all the stages of the process: detonation of the internal charge; the shock wave propagation in the internal gas with further interaction with the lining, including multiple reflections; soil,structure dynamic interaction, including multiple gap openings and closures and wave propagation in the surrounding compressible plastic medium. The interaction problem is solved by a combination of the variational difference method and of the modified Godunov's method based on the fixed Eulerian mesh with the so-called mixed cell. The contact pressures acting on the lining due to both detonation products and soil,lining interaction are computed through the solution of the joint system of finite difference equations of gas, shell and soil dynamics using a simple iteration method. Copyright © 2007 John Wiley & Sons, Ltd. [source] Suppression of the TIG3 tumor suppressor gene in human ovarian carcinomas is mediated via mitogen-activated kinase-dependent and -independent mechanismsINTERNATIONAL JOURNAL OF CANCER, Issue 6 2005Kristina Lotz Abstract The TIG3 gene is a retinoic acid inducible class II tumor suppressor gene downregulated in several human tumors and malignant cell lines. Diminished TIG3 expression correlates with decreased differentiation whereas forced expression of TIG3 suppresses oncogenic signaling pathways and subsequently induces differentiation or apoptosis in tumor cells. Analysis of TIG3 mRNA expression in a large set of cDNA pools derived from matched tumor and normal human tissues showed a significant downregulation of TIG3 in 29% of the cDNA samples obtained from ovarian carcinomas. Using in situ hybridization, we demonstrated expression of TIG3 in the epithelial lining of 7 normal ovaries but loss of TIG3 expression in 15/19 of human ovarian carcinoma tissues. In SKOV-3, CAOV-3 and ES-2 ovarian carcinoma cell lines, downregulation of TIG3 mRNA was reversible and dependent on an activated MEK-ERK signaling pathway. Re-expression of TIG3 mRNA in these cells upon specific interference with the MEK-pathway was correlated with growth inhibition of the cells. In OVCAR-3 and A27/80 ovarian carcinoma cells, TIG3 suppression is MEK-ERK independent, but expression could be reconstituted upon interferon gamma (IFN,) induction. Overexpression of TIG3 in A27/80 ovarian carcinoma cells significantly impaired cell growth and despite increased mRNA levels, TIG3 protein was hardly detectable. These results suggest that TIG3 is negatively regulated by an activated MEK-ERK signaling pathway. Further mechanisms must interfere with TIG3 expression that are independent of MEK and partially include interferon-responsive components. © 2005 Wiley-Liss, Inc. [source] Microbiology's principle of biofilms as a major factor in the pathogenesis of acne vulgarisINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 12 2003Craig N. Burkhart MSBS Propionibacterium acnes reside within the pilosebaceous unit in a biofilm. As such, they live in a community of bacteria that encase themselves within an extracellular polysaccharide lining, which the organisms secrete after adherence to the surface. This gylcocalyx polymer acts as a protective exoskeleton and serves as a physical barrier, limiting effective antimicrobial concentrations within the biofilm microenvironment. The gylcocalyx polymer secreted by P. acnes as a biofilm may explain the immunogenicity of the organism as well as the clinical course of the disease. The P. acnes' biofilm model explains many aspects of acne pathogenesis and therapy, including why prolonged antibiotic treatment is needed, why antibiotic resistance is not a reliable assessment of treatment outcome, why accutane offers long-lasting effectiveness, and why benzoyl peroxide radicals are beneficial. This microbiologic principle of biofilms as applied to acne leads to numerous new pathways of assessment and exploration. [source] | |||||||||||||||||||||||||||||||||||||||||||