Academic literature on the topic 'Elastin fibers'
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Journal articles on the topic "Elastin fibers"
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Akiyama, Mari. "Elastic Fibers and F-Box and WD-40 Domain-Containing Protein 2 in Bovine Periosteum and Blood Vessels." Biomimetics 8, no. 1 (December 23, 2022): 7. http://dx.doi.org/10.3390/biomimetics8010007.
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Elastic fibers form vessel walls, and elastic fiber calcification causes serious vascular diseases. Elastin is a well-known elastic fiber component; however, the insoluble nature of elastic fibers renders elastic fiber component analysis difficult. A previous study investigated F-box and WD-40 domain-containing protein 2 (FBXW2) in the cambium layer of bovine periosteum and hypothesized that fiber structures of FBXW2 are coated with osteocalcin during explant culture. Here, FBXW2 was expressed around some endothelial cells but not in all microvessels of the bovine periosteum. The author hypothesized that FBXW2 is expressed only in blood vessels with elastic fibers. Immunostaining and Elastica van Gieson staining indicated that FBXW2 was expressed in the same regions as elastic fibers and elastin in the cambium layer of the periosteum. Alpha-smooth muscle actin (αSMA) was expressed in microvessels and periosteum-derived cells. Immunostaining and observation of microvessels with serial sections revealed that osteocalcin was not expressed around blood vessels at 6 and 7 weeks. However, blood vessels and periosteum connoted elastic fibers, FBXW2, and αSMA. These findings are expected to clarify the processes involved in the calcification of elastic fibers in blood vessels.
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Schwartz, E., and R. Fleischmajer. "Association of elastin with oxytalan fibers of the dermis and with extracellular microfibrils of cultured skin fibroblasts." Journal of Histochemistry & Cytochemistry 34, no. 8 (August 1986): 1063–68. http://dx.doi.org/10.1177/34.8.3525665.
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The formation of a mature elastic fiber is thought to proceed by the deposition of elastin on pre-existing microfibrils (10-12 nm in diameter). Immunohistochemical evidence has suggested that in developing tissues such as aorta and ligamentum nuchae, small amounts of elastin are associated with microfibrils but are not detected at the light microscopic and ultrastructural levels. Dermal tissue contains a complex elastic fiber system consisting of three types of fibers--oxytalan, elaunin, and elastic--which are believed to differ in their relative contents of microfibrils and elastin. According to ultrastructural analysis, oxytalan fibers contain only microfibrils, elaunin fibers contain small quantities of amorphous elastin, and elastic fibers are predominantly elastin. Using indirect immunofluorescence techniques, we demonstrate in this study that nonamorphous elastin is associated with the oxytalan fibers. Frozen sections of normal skin were incubated with antibodies directed against human aortic alpha elastin and against microfibrillar proteins isolated from cultured calf aortic smooth muscle cells. The antibodies to the microfibrillar proteins and elastin reacted strongly with the oxytalan fibers of the upper dermis. Oxytalan fibers therefore are composed of both microfibrils and small amounts of elastin. Elastin was demonstrated extracellularly in human skin fibroblasts in vitro by indirect immunofluorescence. The extracellular association of nonamorphous elastin and microfibrils on similar fibrils was visualized by immunoelectron microscopy. Treatment of these cultures with sodium dodecyl sulfate/mercaptoethanol (SDS/ME) solubilized tropoelastin and other proteins that reacted with the antibodies to the microfibrillar proteins. It was concluded that the association of the microfibrils with nonamorphous elastin in intact dermis and cultured human skin fibroblasts may represent the initial step in elastogenesis.
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Zheng, Qian, Elaine C. Davis, James A. Richardson, Barry C. Starcher, Tiansen Li, Robert D. Gerard, and Hiromi Yanagisawa. "Molecular Analysis of Fibulin-5 Function during De Novo Synthesis of Elastic Fibers." Molecular and Cellular Biology 27, no. 3 (February 1, 2007): 1083–95. http://dx.doi.org/10.1128/mcb.01330-06.
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ABSTRACT Elastic fibers contribute to the structural support of tissues and to the regulation of cellular behavior. Mice deficient for the fibulin-5 gene (fbln5 − / −) were used to further elucidate the molecular mechanism of elastic fiber assembly. Major elastic fiber components were present in the skin of fbln5 − / − mice despite a dramatic reduction of mature elastic fibers. We found that fibulin-5 preferentially bound the monomeric form of elastin through N-terminal and C-terminal elastin-binding regions and to a preexisting matrix scaffold through calcium-binding epidermal growth factor (EGF)-like (CB-EGF) domains. We further showed that adenovirus-mediated gene transfer of fbln5 was sufficient to regenerate elastic fibers and increase elastic fiber-cell connections in vivo. A mutant fibulin-5 lacking the first 28 amino acids of the first CB-EGF domain, however, was unable to rescue elastic fiber defects. Fibulin-5 thus serves as an adaptor molecule between monomeric elastin and the matrix scaffold to aid in elastic fiber assembly. These results also support the potential use of fibulin-5 as a therapeutic agent for the treatment of elastinopathies.
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Roark, E. F., D. R. Keene, C. C. Haudenschild, S. Godyna, C. D. Little, and W. S. Argraves. "The association of human fibulin-1 with elastic fibers: an immunohistological, ultrastructural, and RNA study." Journal of Histochemistry & Cytochemistry 43, no. 4 (April 1995): 401–11. http://dx.doi.org/10.1177/43.4.7534784.
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We examined the pattern of fibulin-1 mRNA and protein expression in human tissues and cell lines. Fibulin-1 transcripts were found in RNA isolated from most tissues and a variety of cultured cells, including fibroblasts, smooth muscle cells, and several epithelial cell lines, but not endothelial cells, lymphomyloid cells, or a number of carcinoma and melanoma lines. Immunohistochemical analysis showed that fibulin-1 is an intercellular component of connective tissues, predominantly associated with matrix fibers in tissues such as the cervix, dermis, intimal and medial layers of blood vessels, heart valves, meningeal tissue of the brain, Wharton's jelly of the umbilical cord, testis, and lung. Most of the fibers that were immunoreactive with fibulin-1 antibodies also stained with antibodies to the elastic fiber proteins elastin and fibrillin, as well as with Verhoeff's elastin stain. Immunoelectron microscopic analysis of elastin fibers of skin and saphenous vein revealed that fibulin-1 was located within the amorphous core of the fibers, similar to elastin, but it was not in the fibrillin-containing, elastin-associated microfibrils. Our finding that fibulin-1 is an elastic fiber component suggests several possible new functions for fibulin-1, e.g., that it is a structural protein that contributes to the elastic properties of connective tissue fibers or that is involved with the process of fibrogenesis.
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Fhayli, Wassim, Quentin Boëté, Nadjib Kihal, Valérie Cenizo, Pascal Sommer, Walter A. Boyle, Marie-Paule Jacob, and Gilles Faury. "Dill Extract Induces Elastic Fiber Neosynthesis and Functional Improvement in the Ascending Aorta of Aged Mice with Reversal of Age-Dependent Cardiac Hypertrophy and Involvement of Lysyl Oxidase-Like-1." Biomolecules 10, no. 2 (January 23, 2020): 173. http://dx.doi.org/10.3390/biom10020173.
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Elastic fibers (90% elastin, 10% fibrillin-rich microfibrils) are synthesized only in early life and adolescence mainly by the vascular smooth muscle cells through the cross-linking of its soluble precursor, tropoelastin. Elastic fibers endow the large elastic arteries with resilience and elasticity. Normal vascular aging is associated with arterial remodeling and stiffening, especially due to the end of production and degradation of elastic fibers, leading to altered cardiovascular function. Several pharmacological treatments stimulate the production of elastin and elastic fibers. In particular, dill extract (DE) has been demonstrated to stimulate elastin production in vitro in dermal equivalent models and in skin fibroblasts to increase lysyl oxidase–like-1 (LOXL-1) gene expression, an enzyme contributing to tropoelastin crosslinking and elastin formation. Here, we have investigated the effects of a chronic treatment (three months) of aged male mice with DE (5% or 10% v/v, in drinking water) on the structure and function of the ascending aorta. DE treatment, especially at 10%, of aged mice protected pre-existing elastic lamellae, reactivated tropoelastin and LOXL-1 expressions, induced elastic fiber neo-synthesis, and decreased the stiffness of the aging aortic wall, probably explaining the reversal of the age-related cardiac hypertrophy also observed following the treatment. DE could thus be considered as an anti-aging product for the cardiovascular system.
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Saitow, Cassandra B., Steven G. Wise, Anthony S. Weiss, John J. Castellot, and David L. Kaplan. "Elastin biology and tissue engineering with adult cells." BioMolecular Concepts 4, no. 2 (April 1, 2013): 173–85. http://dx.doi.org/10.1515/bmc-2012-0040.
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AbstractThe inability of adult cells to produce well-organized, robust elastic fibers has long been a barrier to the successful engineering of certain tissues. In this review, we focus primarily on elastin with respect to tissue-engineered vascular substitutes. To understand elastin regulation during normal development, we describe the role of various elastic fiber accessory proteins. Biochemical pathways regulating expression of the elastin gene are addressed, with particular focus on tissue-engineering research using adult-derived cells.
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Nygaard, Rie Harboe, Scott Maynard, Peter Schjerling, Michael Kjaer, Klaus Qvortrup, Vilhelm A. Bohr, Lene J. Rasmussen, Gregor B. E. Jemec, and Michael Heidenheim. "Acquired Localized Cutis Laxa due to Increased Elastin Turnover." Case Reports in Dermatology 8, no. 1 (February 13, 2016): 42–51. http://dx.doi.org/10.1159/000443696.
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Cutis laxa is a rare disease characterized by abnormal skin wrinkling and laxity, due to decreased elastin synthesis or structural extracellular matrix defects. We have explored elastin metabolism in a case of adult onset cutis laxa localized to the upper body of a woman. For this purpose, we obtained skin biopsies from affected and unaffected skin areas of the patient and analyzed these with microscopy, polymerase chain reaction, western blotting and cell culture experiments. Skin from the affected area lacked elastin fibers in electron microscopy but had higher mRNA expression of elastin and total RNA. Levels of an apparent tropoelastin degradation product were higher in the affected area. Fibroblast cultures from the affected area were able to produce elastin and showed higher proliferation and survival after oxidative and UVB stress compared to fibroblasts from the unaffected area. In conclusion, we report a case of acquired localized cutis laxa with a lack of elastic fibers in the skin of the patient's upper body. The lack of elastic fibers in the affected skin was combined with increased mRNA expression and protein levels of elastin. These findings indicate that elastin synthesis was increased but did not lead to deposited elastic fibers in the tissue.
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McLaughlin, Precious J., Qiuyun Chen, Masahito Horiguchi, Barry C. Starcher, J. Brett Stanton, Thomas J. Broekelmann, Alan D. Marmorstein, et al. "Targeted Disruption of Fibulin-4 Abolishes Elastogenesis and Causes Perinatal Lethality in Mice." Molecular and Cellular Biology 26, no. 5 (March 1, 2006): 1700–1709. http://dx.doi.org/10.1128/mcb.26.5.1700-1709.2006.
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ABSTRACT Elastic fibers provide tissues with elasticity which is critical to the function of arteries, lungs, skin, and other dynamic organs. Loss of elasticity is a major contributing factor in aging and diseases. However, the mechanism of elastic fiber development and assembly is poorly understood. Here, we show that lack of fibulin-4, an extracellular matrix molecule, abolishes elastogenesis. fibulin-4 −/− mice generated by gene targeting exhibited severe lung and vascular defects including emphysema, artery tortuosity, irregularity, aneurysm, rupture, and resulting hemorrhages. All the homozygous mice died perinatally. The earliest abnormality noted was a uniformly narrowing of the descending aorta in fibulin-4 −/− embryos at embryonic day 12.5 (E12.5). Aorta tortuosity and irregularity became noticeable at E15.5. Histological analysis demonstrated that fibulin-4 −/− mice do not develop intact elastic fibers but contain irregular elastin aggregates. Electron microscopy revealed that the elastin aggregates are highly unusual in that they contain evenly distributed rod-like filaments, in contrast to the amorphous appearance of normal elastic fibers. Desmosine analysis indicated that elastin cross-links in fibulin-4 −/− tissues were largely diminished. However, expression of tropoelastin or lysyl oxidase mRNA was unaffected in fibulin-4 −/− mice. In addition, fibulin-4 strongly interacts with tropoelastin and colocalizes with elastic fibers in culture. These results demonstrate that fibulin-4 plays an irreplaceable role in elastogenesis.
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Wilharm, Nils, Tony Fischer, Alexander Hayn, and Stefan G. Mayr. "Structural Breakdown of Collagen Type I Elastin Blend Polymerization." Polymers 14, no. 20 (October 20, 2022): 4434. http://dx.doi.org/10.3390/polym14204434.
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Biopolymer blends are advantageous materials with novel properties that may show performances way beyond their individual constituents. Collagen elastin hybrid gels are a new representative of such materials as they employ elastin’s thermo switching behavior in the physiological temperature regime. Although recent studies highlight the potential applications of such systems, little is known about the interaction of collagen and elastin fibers during polymerization. In fact, the final network structure is predetermined in the early and mostly arbitrary association of the fibers. We investigated type I collagen polymerized with bovine neck ligament elastin with up to 33.3 weight percent elastin and showed, by using a plate reader, zeta potential and laser scanning microscopy (LSM) experiments, that elastin fibers bind in a lateral manner to collagen fibers. Our plate reader experiments revealed an elastin concentration-dependent increase in the polymerization rate, although the rate increase was greatest at intermediate elastin concentrations. As elastin does not significantly change the structural metrics pore size, fiber thickness or 2D anisotropy of the final gel, we are confident to conclude that elastin is incorporated homogeneously into the collagen fibers.
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Bressan, G. M., D. Daga-Gordini, A. Colombatti, I. Castellani, V. Marigo, and D. Volpin. "Emilin, a component of elastic fibers preferentially located at the elastin-microfibrils interface." Journal of Cell Biology 121, no. 1 (April 1, 1993): 201–12. http://dx.doi.org/10.1083/jcb.121.1.201.
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The fine distribution of the extracellular matrix glycoprotein emilin (previously known as glycoprotein gp115) (Bressan, G. M., I. Castellani, A. Colombatti, and D. Volpin. 1983. J. Biol. Chem. 258: 13262-13267) has been studied at the ultrastructural level with specific antibodies. In newborn chick aorta the protein was exclusively found within elastic fibers. In both post- and pre-embedding immunolabeling emilin was mainly associated with regions where elastin and microfibrils are in close contact, such as the periphery of the fibers. This localization of emilin in aorta has been confirmed by quantitative evaluation of the distribution of gold particles within elastic fibers. In other tissues, besides being associated with typical elastic fibers, staining for emilin was found in structures lacking amorphous elastin, but where the presence of tropoelastin has been demonstrated by immunoelectron microscopy. This was particularly evident in the oxitalan fibers of the corneal stroma, in the Descemet's membrane, and in the ciliary zonule. Analysis of embryonic aorta revealed the presence of emilin at early stages of elastogenesis, before the appearance of amorphous elastin. Immunofluorescence studies have shown that emilin produced by chick embryo aorta cells in culture is strictly associated with elastin and that the process of elastin deposition is severely altered by the presence of antiemilin antibodies in the culture medium. The name of the protein was derived from its localization at sites where elastin and microfibrils are in proximity (emilin, elastin microfibril interface located protein).
Dissertations / Theses on the topic "Elastin fibers"
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Grant, Tyler M. "Microstructural deformation of tendon." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:0ad70415-af7a-4b97-a93a-d17a73d8ff44.
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Tendon disorders are painful, disabling, and a major healthcare problem, with millions of people affected by tendon injuries each year. Current treatment strategies are inadequate and knowledge of the underlying mechanobiological mechanisms is required to develop novel therapies. Although the tissue–level properties of tendon are well–documented there remains a lack of understanding of the deformation mechanisms of this complex tissue. Therefore, the aim of this thesis is to characterize the microstructural deformation of tendon through biological imaging, mechanical testing, and computational modeling. Emphasis is placed on the structure and function of elastic fibers in tendon, whose role is poorly understood. First, histology, immunohistochemistry, and multiphoton microscopy are used to characterize the organization of elastic fibers in healthy and damaged tendon providing detailed microstructural information on their morphology and location for the first time. Elastic fibers are found to have a sparse distribution in the extracellular matrix, but are highly concentrated in the endotenon sheath and pericellular matrix. Moreover, damaged specimens are found to have a severely disrupted elastic fiber network. Elastic fibers likely contribute to fascicular deformation mechanisms and the micromechanical environment of tenocytes, which are expected to be disrupted in damaged tendon. Second, mechanical testing and enzyme treatments are used to analyze the mechanical contribution of elastic fibers to tendon. Elastase is found to significantly affect the mechanical properties of the tissue and remove the elastin component of both tendon and a control collagen–elastin biomaterial. However, elastase is also found to degrade non–elastin structural molecules that may contribute to tendon mechanics. The mechanical changes associated with the elastase treatment suggest that elastic fibers do not contribute to the elastic recoil of tendon as previously hypothesized. Third, multiphoton microscopy in combination with a novel microtensile testing machine is used to observe the deformation of collagen fibrils and tenocytes in tissue exposed to load. Tissue displacement is consistent with a helical arrangement of fibrils and nuclei experience significant elongation under physiological conditions. These results suggest that a helical arrangement of fibrils is responsible for the nonlinear stress–strain response of tendon and that nuclei are prime candidates for sensing mechanical forces in tendon. Finally, computation modeling and structural imaging are used to generate a microstructural finite element model of tendon. A helical model with embedded pericellular matrix is able to reproduce the stress–strain response and cell–level deformation of the tissue. The pericellular matrix is found to amplify mechanical forces exposed to cells, which is required to initiate mechanobiological stimulation of tenocytes under physiological conditions. Therefore, the structure and composition of the PCM during health and disease is expected to significantly affect mechanobiological mechanisms of tendon. The work presented in this thesis has used new experimental methods to provide novel insight into the structure, function, and deformation mechanisms of tendon. The techniques and concepts developed are widely applicable to the study of collagenous tissues in health and disease. In particular, observations regarding the pericellular matrix may lead to the development of new tissue–engineered and pharmacological strategies for the treatment of tendon disorders.
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Toroian, Damon Armen. "The Size exclusion characteristics of collagen and elastin fibers and role of fetuin in their calcification." Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2007. http://wwwlib.umi.com/cr/ucsd/fullcit?p3266770.
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Thesis (Ph. D.)--University of California, San Diego, 2007.Title from first page of PDF file (viewed August 6, 2007). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references.
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Ferron, Florence Joelle. "The implications of fibulin-5 on elastin assembly and its role in the elastic fiber /." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=101846.
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The extracellular matrix (ECM) is the material found surrounding the cells in a tissue. One component of the ECM is the elastic fiber, which confers the property of elasticity to its environment. Organs such as the lung, skin and major blood vessels have an abundance of elastic fibers so that they are able to expand and recoil. Elastic fibers are composed of two main components; elastin and microfibrils. Microfibrils are composed primarily of fibrillin-1 and provide a scaffold unto which tropoelastin monomers assemble. Elastic fibers interact with many other proteins in the ECM, one of which is fibulin-5. Based on the severe elastic fiber defects observed in the fibulin-5 null mouse, it was established that fibulin-5 plays an essential role in elastic fiber development. This role may be in the deposition of tropoelastin onto microfibrils and/or in stabilizing the elastic fibers in the extracellular matrix. In the present study, the relationship between fibulin-5 and the elastic fiber was investigated through a number of in vivo and in vitro experiments. To test the hypothesis that fibulin-5 requires the presence of elastin to assemble in the ECM, full-length recombinant fibulin-5 (rF5) was purified from transfected cells and used to make a fibulin-5 antibody. Solid-phase binding assays using rF5 showed that fibulin-5 binds tropoelastin at two sites; the initial portion of the C-terminus and the first calcium-binding epidermal growth factor-like domain at the N-terminus. Immunofluorescence staining of elastin null mouse embryonic fibroblast cultures revealed that fibulin-5 does not require elastin to be present in the ECM in order to assemble. Subsequently, solid-phase binding assays showed that fibulin-5 can bind to the N-terminus of fibrillin-1. To determine if fibulin-5 could exist independent of elastin and/or fibrillin-1 in vivo, an immunohistochemical analysis was conducted on heart, liver, lung, colon, spleen, testis and kidney. All three proteins were co-localized in all organs except in the kidney, where fibrillin-1 was found to independently stain the capillary tufts of the renal corpuscles and renal tubules. Thus, fibulin-5 may be co-regulated with elastin and is not present on elastin-independent microfibrils. Additionally, novel locations of elastic fibers were uncovered in the heart, liver, colon, spleen and testis. Overall, this study provides important insights as to the role of fibulin-5 in elastic fiber structure and assembly and also reveals the complexity in understanding the pathogenesis of diseases involving elastic fiber proteins.
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Smith, Kinley. "The distribution and function of elastin and elastic fibres in the canine cruciate ligament complex." Thesis, University of Liverpool, 2010. http://livrepository.liverpool.ac.uk/1437/.
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Anterior cruciate ligament rupture (ACL) is a major source of morbidity in the dog, leading to severe osteoarthritis of the knee joint and marked lameness. Following rupture, the ACL will not heal and in the dog, ACL rupture is thought to be the end stage of degenerative ligament disease (non-contact ACL injury). The extracellular matrix (ECM) of CLs has been extensively studied but little is known of the role of elastic fibres in the physiology of the ECM, the mechanics of CL function and in CL degeneration. Elastic fibres include polymers of fibrillins (microfibrils), bundles of microfibrils (oxytalan fibres) and elastin fibres (bundles of microfibrils with an elastin core). The hypothesis of this thesis is that elastin has a mechanical and a biological role in the canine cruciate ligament complex. It is further hypothesised that the distribution and function of elastic fibres will vary between three breeds of dog with differing risk of ACL rupture are: the greyhound with a low risk, the beagle with a low-to-moderate risk and the Labrador retriever with a high risk. The distribution of elastic fibres, fibrillins and cells was investigated throughout the CL complex using a combination of histochemical staining and immunofluorescence. CL microanatomy was studied using Nomarski differential interference microscopy. Elastin was measured biochemically and compared to histologic assessment of tissue architecture, elastic fibre staining and other biochemical parameters. The biological effect of elastin degradation products (EDPs) was assessed in an in vitro ACL cell culture model. A low risk dog breed to ACL rupture (greyhound) was used in all investigations and comparisons were made with other breeds with regard to cellular and elastic fibre anatomy. Differences in cell morphology between breeds with differing risk of ACL rupture may reflect fundamental differences in CL physiology possibly through altered cell-to-cell communication. Cellular and matrix changes, considered degenerative, were seen throughout the CL complex and may reflect adaptation rather than degeneration in certain dog breeds such as the greyhound. Elastin content ranged from 5.9 to 19.4% of ligament dry weight. This was a far greater proportion of canine CLs than previously. Elastin fibres may have a mechanical role in bundle reorganization following ligament deformation. The distribution of fibrillins 1 and 2 was different from the pattern previously reported in tendon and may represent a fundamental difference between ligament and tendon. In the greyhound CL there was a significant proportional increase in oxytalan fibre staining with advancing CL degeneration. This response was seen also in the Labrador retriever and the beagle but the increase in oxytalan fibre staining was less marked with advancing degeneration. Therefore production of oxytalan fibres may reflect a healing response in damaged CL tissue in breeds at a low risk of ligament rupture. Fragments of elastin containing the VGVAPG motif affect canine ACL cells in vitro resulting in increased transcription of fibrillin 2 mRNA. Additionally, there was synergism with TGF-β1 resulting in upregulation of the elastin laminin receptor 1, through which EDPs are transduced. EDPs may thus have a role in response to injury in the CL.
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Cholst, Beth (Beth Ellen). "Elastic stretchable optical fibers." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/105710.
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Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2016.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 23-24).
The utilization of soft materials in the design of optical systems provides opportunities for imparting these optical systems with completely unprecedented properties. This will enhance performance of systems, such as optical fibers, and enable new application scenarios. Here, we report the design, manufacture and characterization of elastic stretchable optical fibers. Analogous to conventional optical fibers, the elastic fibers consist of a high index core, made from a polystyrene-polyisoprene triblock copolymer, and a low refractive index cladding, formed by a fluorinated thermoplastic elastomer. The fibers are manufactured by co-extrusion of their constituent materials. They can be stretched to 300% strain repeatedly. Axial deformation of the fibers results in a variation of their light guiding properties. The fibers' attenuation coefficient was determined to be 0.021 ± 0.003 dB/mm, which is 2 orders of magnitude higher than for standard optical glass fibers. The high attenuation coefficient is likely due to scattering of light by air inclusions incorporated during manufacturing at the core-cladding interface. The fibers elastic modulus is 960 ± 280 kPA and their yield strength lies in the range of 2150 ± 480 kPA. The variation in intensity of guided light as a function of strain applied axially to the fibers was measured with a customized optical setup. Our experiments show that elastic optical fibers have properties that make them desirable as mechanical sensors and components in a range of other applications, provided current manufacturing shortcomings are addressed. The fibers could be used for light delivery to individual pixels of flexible deformable displays. They could be incorporated into clothing for delivery of light for display purposes or textile-integrated photonic circuits to create functional textiles. Because the fibers can stretch, the textiles or displays will be able to undergo deformation without damage or loss in performance.
by Beth Cholst.
S.B.
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Newcomb, Bradley Allen. "Gel spun PAN and PAN/CNT based carbon fibers: From viscoelastic solution to elastic fiber." Diss., Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/54881.
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This study focuses on the processing, structure, and properties of gel spun polyacrylonitrile (PAN) and polyacrylonitrile/carbon nanotube (PAN/CNT) carbon fibers. Gel spun PAN based carbon fibers are manufactured beginning with a study of PAN dissolution in an organic solvent (dimethylformamide, DMF). Homogeneity of the PAN/DMF solution is determined through dynamic shear rheology, and the slope of the Han Plot (log G’ vs log G’’). Solutions were then extruded into gel spun fibers using a 100 filament fiber spinning apparatus in a class 1000 cleanroom. Fibers were then subjected to fiber drawing, stabilization, and carbonization, to convert the PAN precursor fiber into carbon fiber. Carbon fiber tensile strength was shown to scale with the homogeneity of the PAN/DMF solution, as determined by the slope of the log G’ vs log G’’ plot. After the development of the understanding between the homogeneity of the PAN/DMF solutions on the gel spun PAN based carbon fiber tensile properties, the effect of altering the fiber spinning processing conditions on the gel spun PAN based carbon fiber structure and properties is pursued. Cross-sectional shape of the gel spun PAN precursor fiber, characterized with a stereomicroscope, was found to become more circular in cross-section as the gelation bath temperature was increased, the amount of solvent in the gelation bath was increased, and when the solvent was switched from DMF to dimethylacetamide (DMAc). Gel spun fibers were then subjected to fiber drawing, stabilization, and carbonization to manufacture the carbon fiber. Carbon fibers were characterized to determine single filament tensile properties and fiber structure using wide-angle x-ray diffraction (WAXD) and high resolution transmission electron microscopy (HRTEM). It was found that the carbon fiber tensile properties decreased as the carbon fiber circularity increased, as a result of the differences in microstructure of the carbon fiber that result from differences in fiber spinning conditions. In the second half of this study, the addition of CNT into the PAN precursor and carbon fiber is investigated. CNT addition occurs during the solution processing phase, prior to gel spinning. As a first study, Raman spectroscopy is employed to investigate the bundling behavior of the CNT after gel spinning and drawing of the PAN/CNT fibers. By monitoring the peak intensity of the (12,1) chirality in the as-received CNT powder, and in differently processed PAN/CNT fibers, the quality of CNT dispersion can be quickly monitored. PAN/CNT fibers were then subject to single filament straining, with Raman spectra collected as a function of PAN/CNT filament strain. As a result of the PAN/CNT strain, stress induced G’ Raman band shifts were observed in the CNT, indicating successful stress transfer from the surrounding PAN matrix to the dispersed CNT. Utilization of the shear lag theory allows for the calculation of the interfacial shear strength between the PAN and incorporated CNT, which is found to increase as the quality of CNT (higher aspect ratio, increased graphitic perfection, and reduced impurity content), quality of CNT dispersion, and fiber drawing increase. PAN/CNT fibers were then subjected to stabilization and carbonization for the manufacture of gel spun PAN/CNT based carbon fibers. These fibers were then characterized to investigate the effect of CNT incorporation on the structure and properties of the carbonized fibers. The gel spun PAN/CNT based carbon fibers were compared to commercially produced T300 (Toray) and IM7 (Hexcel) carbon fibers, and gel spun PAN based carbon fiber. Fiber structure was determined from WAXD and HRTEM. Carbon fibers properties investigated include tensile properties, and electrical and thermal conductivity. PAN/CNT based carbon fibers exhibited a 103% increase in room temperature thermal conductivity as compared to commercially available IM7, and a 24% increase in electrical conductivity as compared to IM7. These studies provide a further understanding of the processing, structure, property relationships in PAN and PAN/CNT based carbon fibers, beginning at the solution processing phase. Through the manufacture of more homogeneous PAN/DMF solutions and investigations of the fiber spinning process, gel spun PAN based carbon fibers with a tensile strength and modulus of 5.8 GPa and 375 GPa, respectively, were successfully manufactured in a continuous carbonization facility. Gel spun PAN/CNT based carbon fibers exhibit room temperature electrical and thermal conductivities as high as 74.2 kS/m and 33.5 W/m-K.
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Vieira, Gislaine. "Analise da arquitetura da aorta de pacientes hipertensos e normotensos." [s.n.], 2009. http://repositorio.unicamp.br/jspui/handle/REPOSIP/310241.
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Orientador: Konradin MetzeDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas
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Resumo: Fibras elásticas são componentes essenciais da aorta e remodelamento é acompanhado em muitas doenças e eventos que ameaçam a vida, como dissecção e rupturas. Fibras elásticas podem ser facilmente visualizadas quando coradas com H&E e examinadas por microscopia de fluorescência. Nosso objetivo foi criar um sistema de análise automática da textura das fibras elásticas comparando aorta de pacientes normotensos e hipertensos. O sistema de análise foi composto por Microscópio invertido Olympus IX-81 equipado com scanner FV 300 que utiliza laser FV-5 COMB2, utilizando laser de argônio a 488 nm, objetiva 40x usando óleo de imersão. A espessura da aorta varia de 2 a 3 mm, e a imagem completa foi composta por justaposição de imagens de 220x220 µm utilizando software Fluoview. Para análise foi utilizado o programa gliding box , que é uma caixa deslizadora de 128x128 pixels, que percorre a imagem da aorta pixel a pixel em toda sua extensão. Para análise computadorizada da textura foram utilizados programas computacionais (entropia, homogeneidade local e segundo momento angular derivado da matriz de co-ocorrência de Haralick). Foram calculados e plotados em diagramas resultados equivalentes à topografia histológica da imagem. Em cada caminho o gliding box percorreu entre 2000 e 3000 pixels da textura, revelando a topografia local e sua variação. Foi comparada a textura de fibras elásticas de cortes histológicos corados com HE de 24 pacientes normotensos e 30 hipertensos, adultos de ambos os sexos oriundos de autópsias realizadas no Depto de Anatomia Patológica. Para comparação entre textura e idade utilizou-se Correlação de Pearson, e a textura foi comparada entre os grupos com o auxílio do teste t. Resultados: Tanto nos pacientes normotensos como nos hipertensos não houve correlação entre: número de fibras elásticas ou distâncias entre elas, para as análises de Haralick e idade dos pacientes. No entanto, a entropia em pacientes normotensos (r=0,60; p=0,004) e a homogeneidade local (r=0,43; p =0,049) demonstraram acréscimo da variação topográfica com o envelhecimento, fato que não ocorreu nos hipertensos. Quando comparadas com aortas normotensas, as hipertensas revelaram menos fibras elásticas (p<0,0001), maior variabilidade e distâncias (p<0,0001), aumento da média da espessura e maior variabilidade da espessuras das fibras ( p<0,0001). Conclusão: Demonstramos que o presente método é uma ferramenta que permite uma análise objetiva da textura de fibras elásticas da aorta com a possibilidade de quantificar processos patológicos. Observamos que em pacientes normotensos, o número médio de fibras elásticas e a distância entre elas são constantes e ocorrem discretas alterações da arquitetura com o aumento da idade. Em hipertensos, o distúrbio arquitetural é mais evidente e ocorrem perdas de fibras elásticas.
Abstract: The elastic fiber network is an essential component of the aorta. Its remodeling accompanies many diseases and may provoke life-threatening events, such as dissection or rupture. Elastic fibers can be easily demonstrated in eosin-stained histologic sections examined by fluorescence microscopy. The aim of our study was to create an automatic texture analysis system of the elastic fibers and to apply it in human aortas comparing normotensive and hypertensive patients. The analysis sytem was composed of an Olympus IX-81 inverted microscope, a FV300 scan head and a FV-5 COMB2 laser combiner. The fluorescence of the hematoxylin and eosin-stained slides was excited with the 488 nm line of an Argon laser using a 40x oil immersion objective. The Fluoview software was used to reconstruct the images. The full image of the whole sample (2 or 3mm long) was composed by several 220x220. Then a gliding box of 128x128 pixels was running in 1-pixel steps along a predefined axis parallel to the bottom line of the image. For every new box, computerized analysis of texture features (entropy, local homogeneity and the second angular moment derived from the gray-level co-occurrence matrix) were calculated and plotted in diagrams, where the position on the x-axis was equivalent to the topography in the histologic picture. In that way for each "run" of the gliding box about 2000 to 3000 values of a texture feature were obtained, thus revealing precisely its topographic postion and its variabilty. We compared the elastic fiber texture in routinely HE-stained histologic slides of the aorta ascendens in 24 normotensive and 30 hypertensive adult patients of both sexes and of similar age from our autopsy files. Pearson correlations were calculated between the texture features and the age. Texture features were compared between both groups with the help of the t-test. Results: In normotensive and hypertensive patients no correlations were found between the number of elastic fibers, their thickness or their distance and the Haralick features and the age of the patients. But in normotensive patients entropy (r=0,60; p=0,004) and local homogeneity (r=0,43; p =0,049) showed increasing topographic variations in patients with advanced age, which was not the case for hypertensive patients. When comparing with normotensive aortas, the hypertensive ones revealed less elastic fiber layers (p<0,0001), a greater variabilty of the fiber distance (p<0,0001), increased mean fiber thickness and a greater varaibilty of the fiber thickness( p<0,0001) Conclusion: We showed that the presented method provides a new tool for an objective automatic texture analysis of the elastic fiber texture of the aorta with the possibility of quantification of the disease process. Although in normotensive patients, the mean number and distance of the elastic fibers is constant, discrete local alterations of the architecture appear with increasing age. In hypertensive patients there are more pronounced architectural alterations with loss of the fiber layers.
Universidade Estadual de Campi
Biologia Estrutural, Celular, Molecular e do Desenvolvimento
Mestre em Fisiopatologia Médica
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Alves, Calebe de Andrade. "Dinâmica de degradação e reparação de fibras elásticas sob tensão." reponame:Repositório Institucional da UFC, 2013. http://www.repositorio.ufc.br/handle/riufc/13737.
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ALVES, Calebe de Andrade. Dinâmica de degradação e reparação de fibras elásticas sob tensão. 2013. 71 f. Dissertação (Mestrado em Física) - Programa de Pós-Graduação em Física, Departamento de Física, Centro de Ciências, Universidade Federal do Ceará, Fortaleza, 2013.Submitted by Edvander Pires (edvanderpires@gmail.com) on 2015-10-23T18:48:28Z No. of bitstreams: 1 2013_dis_caalves.pdf: 1922274 bytes, checksum: beae2409f015f4b21f8f423815937fa0 (MD5)
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Extracelular matrix, the biological structure that supports cells in animal tissue, is composed of elastic fibers such as collagen and elastin. It is known that enzymes activity plays an important role in maintenance of these elastic fibers. The imbalance between destruction and repair of the elastic fibers can lead to diseases such as fibrosis and emphysema. In this study, we present a simple model to simulate enzymatic digestion and repair of elastic fibers under tension. The fiber is represented by a chain of linearly elastic springs in series surrounded by two layers of sites along which particles representing enzymes and fragments can diffuse. These particles can biding-unbinding in the fiber simulating the reaction process by changing the local stiffness by a multiplicative factor. We study the distribution of the number of visits of particles to the springs as function of time and the consequent change of the fiber stiffness, under different initial conditions (model parameters). We show that, due to no linearity of the model, the degradation effect prevails even when the concentrations of the two type of agents are the same. There is no relation between the number of degradative and rigidifying particles that garantee that the fiber stiffness remains constant. When an anisotropy factor is included on the model and the system behaviour becomes dependent on the tension applied to the fiber, we show that the increase of tension in general contributes to the increase on enzymatic activity. We believe this study can help better understand progression of diseases such as emphysema and fibrosis.
A Matriz Extracelular, a estrutura biológica que sustenta as células em tecidos animais, é composta de fibras elásticas como colágeno e elastina. Sabe-se que a atividade enzimática desempenha papel fundamental na manutenção dessas fibras elásticas. O desequilíbrio entre destruição e reparo das fibras elásticas pode levar a doenças como fibrose e enfizema. Neste estudo, nós apresentamos um modelo simples para simular digestão enzimática e reparo de fibras sob tensão. A fibra é representada por uma cadeia de molas linearmente elásticas em série. A fibra é cercada por duas camadas de sítios ao longo dos quais partículas representantes de enzimas e fragmentos podem se difundir. Estas partículas podem se ligar e se desligar da fibra, simulando o processo de reação ao alterar a constante elástica local por um fator multiplicativo. Estuda-se a distribuição do número de visitas de partículas degradadoras e enrijecedoras às molas em função do tempo de difusão e a consequente variação da rigidez da fibra, sob diversas condições iniciais (parâmetros do modelo). Mostra-se que, devido a características matemáticas intrínsecas ao modelo, o efeito de degradação prevalece sobre o de enrijecimento ainda quando a concentração de agentes de ambos os tipos é a mesma. Não há relação entre o número de partículas degradadoras e enrijecedoras que garanta a estabilidade da constante elástica da fibra. Quanto um fator de anisotropia é incluído no modelo e o comportamento do sistema passa a depender da tensão aplicada à fibra, mostra-se que o aumento da tensão em geral contribui para o aumento da atividade enzimática. Este estudo poderá ajudar a entender a progressão da degradação de tecidos em doenças como enfisema e fibrose.
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Lima, Vanessa Morais. "Efeitos da penicilina G na pelve renal de ratos Wistar (Rattus norvegicus albinus) normais e diabéticos." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/10/10132/tde-09102013-180434/.
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A penicilina G é um dos antibióticos mais importantes. Além de possuir um baixo preço e comprovada eficácia de tratamento, mostra inúmeras possibilidades para a redução da morbidade e mortalidade por doenças infecciosas em todo o mundo. Como eventualmente este medicamento causa sequelas no parênquima renal e estruturas associadas, e sendo que a secreção da rede tubular renal contribui para a excreção da penicilina G, onde cerca de 60% do antibiótico é eliminado pela urina, nos propomos a fazer um estudo das principais alterações que possam ocorrer na pelve renal de ratos normais e ratos induzidos à diabetes. Este projeto tem o propósito de descrever e analisar as fibras colágenas, musculares lisas e elásticas da pelve renal de ratos wistar observando alterações estruturais e ultraestruturais dos grupos experimentais quando comparados ao grupo controle com relação ao uso da penicilina G. Os ratos foram divididos em 4 grupos, ratos Wistar normais (N); ratos Wistar tratados com penicilina G (NP); ratos Wistar induzidos à diabetes (D); ratos Wistar diabéticos com penicilina G (DP). Os ratos dos grupos D e DP foram induzidos ao diabetes por aloxano. A região da pelve renal com representação das fibras foi coletada e reduzida em pequenos fragmentos. Os cortes obtidos foram utilizados para Microscopia Eletrônica de Transmissão e corados pelos seguintes métodos para Microscopia Óptica: Hematoxilina Férrica para evidenciação de fibras elásticas; Resorcina fucsina para evidenciação de fibras elásticas e elaunínicas; Resorcina fucsina após oxidação com solução aquosa a 1% de oxona para evidenciação de fibras elásticas, elaunínicas e oxitalânicas; Azan para evidenciação do componente colágeno e muscular lisa; Picrosírius para observação do componente colágeno (especificamente tipo I e III); e Hematoxilina e Eosina, para evidenciação do componente celular. A análise microscópica e a histomorfometria mostraram que a Penicilina G altera os componentes fibrosos da pelve renal, fazendo com que as áreas de fibras musculares lisas e de colágeno tipo III fossem aumentadas e as fibras elásticas maduras diminuídas (neste caso, apenas entre N e NP). O Diabetes mellitus mostrou-se como uma doença metabólica também capaz de alterar a morfologia da pelve, fazendo com que a área de fibras musculares lisas aumentasse, a área de colágeno tipo I e a quantidade de fibras elásticas maduras e elaunínicas diminuísse e as oxitalânicas aumentassem, além de um notável aumento na quantidade de mitocôndrias. Podemos inferir que a antibioticoterapia feita pela penicilina G e o diabetes, provocam diferenças estruturais e ultraestruturais na pelve renal dos ratos Wistar, principalmente na organização dos componentes fibrosos elástico, muscular e colágeno.Penicillin G is the most important antibiotics. Besides having a low cost and proven effectiveness of treatment, it shows great possibilities for reducing morbidity and mortality from infectious diseases worldwide. As this medicine may cause sequelae in the renal parenchyma and associated structures, and since the net renal tubular secretion contributes to the excretion of penicillin G, where about 60% of the antibiotic is eliminated in urine, this study aims to investigate the main structural and ultrastructural changes occurring in the kidney of normal and diabetes rats. Thus, this project aims to describe and analyze the collagen fibers, smooth muscle and elastic fibers of the renal pelvis of Wistar rats, comparing control and penicillin G-treated animals. The animals were divided into 4 groups, normal rats (N), Wistar rats treated with penicillin G (NP); rats induced diabetes (D), diabetic Wistar rats with penicillin G (DP). The diabetes was induced in groups D and DP by alloxan. The fibrotic region of the renal pelvis was collected and reduced into small fragments. The sections were used for the transmission electron microscopy and stained by the following methods for optic microscopic: Iron Hematoxylin for disclosure of elastic fibers; Resorcin fuchsin for disclosure of elastic and elauninic fibers; Resorcin fuchsin after oxidation with 1% aqueous solution of oxone for disclosure of elastic, elauninic and oxytalan fibers; Azan evidencing the collagen and smooth muscle components; Picrosirius for observation of the collagen component (specifically type I and III); and Hematoxylin and Eosin, to show the cellular component. Microscopic and histomorphometry analysis showed that penicillin G alters the fibrous components of the renal pelvis, increasing areas of smooth muscle fibers and collagen type III deposition and decreasing mature elastic fibers (in this case, only between N and NP). Diabetes mellitus proved to be a metabolic disease also able to alter the morphology of the pelvis, leading to the augmentation of smooth muscle fiber area. Moreover, the area of type I collagen and the amount of mature elastic and elauninic fibers were diminished, while oxytalan fibers increased, together with a remarkable increase in the number of mitochondria. We can infer that the antibiotic therapy made by penicillin G and the diabetes, cause structural and ultrastructural differences in the renal pelvis of rats, mainly in the organization of elastic fiber, muscular and collagen components.
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Rosado, João Pedro Gaio Meireles. "Alterações estruturais da matriz extracelular do prepúcio humano causadas pelo tabagismo." Universidade do Estado do Rio de Janeiro, 2011. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=3859.
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Conselho Nacional de Desenvolvimento Científico e TecnológicoOs autores têm como objetivo, investigar a matriz extra celular, musculatura lisa e densidade vascular do prepúcio de pacientes tabagistas. Espécimes de prepúcio foram obtidas de 20 jovens adultos (média de idade= 27.2) submetidos a postectomia. Dentre os pacientes analisados, um grupo (n=10) possui história prévia de tabagismo (3 to 13 maços/ano, média = 5.8 3.2), e outro grupo (n=10) formam o grupo controle, não fumantes. A coloração de Tricrômico Masson foi utilizada para quantificar tecido conectivo, musculatura lisa e vasos. A coloração Resorcina-fucsina de Weigert foi utilizada para estabelecer as fibras do sistema elástico e a coloração, Vermelho de Picrosirius para o estudo do colágeno. O estudo estereológico foi realizado utilizando o software Image J, para determinar as densidades volumétricas. Para a análise bioquímica o colágeno total foi determinado em μg de hidroxiprolina por MG de tecido seco. O estudo estatístico foi realizado lançando mão do t-teste (p<0,05). Fibras do sistema elástico de fumantes apresentaram-se aumentadas em 42.5% quando comparado ao grupo controle (p=0,002). Em contraste, musculatura lisa (p=0,42) e densidade vascular (p=0,16) não mostraram nenhuma diferença estatística. Foi realizado uma análise quantitativa utilizando Vermelho de Picrosirius sob luz polarizada, que evidenciou a presença de colágeno tipo I e III, sem diferença estatisticamente significativa. A concentração total do colágeno não mostrou diferença entre tabagistas e o grupo controle. (73.1μg/mg 8.0 vs. 69.2μg/mg 5.9, respectivamente, p=0,23). Tabagismo está associado a um significante aumento de fibras do sistema elástico do tecido prepucial. Estes resultados podem, possivelmente, explicar os altos índices de falha na uretroplastia peniana, com uso de flap de prepúcio em fumantes
It has been speculated by McAninch et al. (1), that smokers might experience worse results after urethral reconstruction. We decided to investigate the extracellular matrix, smooth muscle and vascular density in the foreskin of smoker patients. Foreskin samples were obtained from 20 young adults (ranging in age from 23 to 36 years; mean SD = 27.2 5.8) submitted to circumcision from July 2008 to October 2009. Of the patients analyzed, one group (n=10) had a previous history of chronic smoking (3 to 13 packs/year, mean = 5.8 3.2) i.e., one pack per day for 3 to 13 years. The control group was composed of 10 non-smoker patients. Foreskin samples were studied by histology and biochemistry. Means were compared using the two-tailed t-test (p<0.05). The elastic system fibers in the foreskin of smoker patients increased in 42.5% when compared to the control group. In contrast, the smooth muscle fibers, vascular density and total collagen concentration did not show any significant variation between smokers and controls. Smoking is associated with a significant increase of elastic system fibers in foreskin tissue. These results could possibly explain the high failure rate of penile urethroplasty in smokers by using foreskin flaps
Books on the topic "Elastin fibers"
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Chen, Li Che Ted. A unique method of determining the elastic and engineering constants of unidirectional fibre-reinforced composite plates using ultrasound. [Downsview, Ont.]: Department of Aerospace Science and Engineering, University of Toronto, 1990.
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Chen, Li Che Ted. A unique method of determining the elastic and engineering constants of unidirectional fibre-reinforced composite plates using ultrasound. Ottawa: National Library of Canada = Bibliothèque nationale du Canada, 1991.
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Johnson, W. S. Elastic-plastic stress concentrations around crack-like notches in continuous fiber reinforced metal matrix composites. Hampton, Va: National Aeronautics and Space Administration, Langley Research Center, 1987.
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Johnson, W. S. Elastic-plastic stress concentrations around crack-like notches in continuous fiber reinforced metal matrix composites. Hampton, Va: National Aeronautics and Space Administration, Langley Research Center, 1987.
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Ramamurthi, Anand. Elastic Fiber Matrices. CRC Press, 2016. http://dx.doi.org/10.1201/9781315370842.
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J, Nagem Raymond, and United States. National Aeronautics and Space Administration. Scientific and Technical Information Division, eds. Energy in elastic fiber embedded in elastic matrix containing incident SH wave. [Washington, DC]: National Aeronautics and Space Administration, Scientific and Technical Information Division, 1989.
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National Aeronautics and Space Administration (NASA) Staff. Energy in Elastic Fiber Embedded in Elastic Matrix Containing Incident Sh Wave. Independently Published, 2018.
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Elastic Fiber Matrices: Biomimetic Approaches to Regeneration and Repair. Taylor & Francis Group, 2016.
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Ramamurthi, Anand, and Chandrasekhar Kothapalli. Elastic Fiber Matrices: Biomimetic Approaches to Regeneration and Repair. Taylor & Francis Group, 2018.
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Ramamurthi, Anand, and Chandrasekhar Kothapalli. Elastic Fiber Matrices: Biomimetic Approaches to Regeneration and Repair. Taylor & Francis Group, 2018.
Find full textBook chapters on the topic "Elastin fibers"
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Matsumoto, Takeo, Shukei Sugita, and Kazuaki Nagayama. "Tensile Properties of Smooth Muscle Cells, Elastin, and Collagen Fibers." In Vascular Engineering, 127–40. Tokyo: Springer Japan, 2016. http://dx.doi.org/10.1007/978-4-431-54801-0_7.
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Veit, Dieter. "Elastane." In Fibers, 749–59. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-15309-9_36.
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Uitto, Jouni. "Elastic Fibers." In Biology of the Integument, 810–14. Berlin, Heidelberg: Springer Berlin Heidelberg, 1986. http://dx.doi.org/10.1007/978-3-662-00989-5_41.
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Levine, Martin. "Elastic Fibers and Proteoglycans." In Topics in Dental Biochemistry, 81–99. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-540-88116-2_6.
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Mecham, Robert P., and John E. Heuser. "The Elastic Fiber." In Cell Biology of Extracellular Matrix, 79–109. Boston, MA: Springer US, 1991. http://dx.doi.org/10.1007/978-1-4615-3770-0_4.
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Davis, Elaine C., and Robert P. Mecham. "Elastic Fiber Organization." In Tissue Engineering, 26–34. Boston, MA: Birkhäuser Boston, 1993. http://dx.doi.org/10.1007/978-1-4615-8186-4_3.
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Suriano, Raffaella, Andrea Mantelli, Gianmarco Griffini, Stefano Turri, and Giacomo Bonaiti. "Styrene-Free Liquid Resins for Composite Reformulation." In Systemic Circular Economy Solutions for Fiber Reinforced Composites, 99–123. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-22352-5_6.
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AbstractThree different classes of thermosetting styrene-free resins were investigated to assess their suitability to constitute the matrix phase in the reformulation of composites reinforced with mechanically recycled glass fibers. Resin reactivity and mechanical properties after curing were compared to commercial styrene-based, unsaturated polyester resins. The polymeric resin, acting as a binder, could be properly selected depending on the desired reactivity, processability, and mechanical behavior. Some prototypal examples of reformulated composites with different types and contents of recycled glass fibers were produced and mechanically tested. The combination of the epoxy resin with up to 60 wt% of mechanically recycled glass fibers resulted in an increase of elastic modulus up to 7.5 GPa.
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Uitto, Jouni, and Lasse J. Ryhänen. "Pathology of the Elastic Fibers." In Connective Tissue Disease, 399–422. Boca Raton: CRC Press, 2021. http://dx.doi.org/10.1201/9781003210016-21.
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Pavelka, Margit, and Jürgen Roth. "Collagen and Elastic Fibres." In Functional Ultrastructure, 278–79. Vienna: Springer Vienna, 2010. http://dx.doi.org/10.1007/978-3-211-99390-3_143.
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Uitto, Jouni, Sylvia Hsu-Wong, Stacy D. Katchman, Muhammad M. Bashir, and Joel Rosenbloom. "Skin Elastic Fibres: Regulation of Human Elastin Promoter Activity in Transgenic Mice." In Novartis Foundation Symposia, 237–58. Chichester, UK: John Wiley & Sons, Ltd., 2007. http://dx.doi.org/10.1002/9780470514771.ch13.
Full textConference papers on the topic "Elastin fibers"
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Haslach, Henry W., Jonathan Chung, and Aviva Molotsky. "Fracture Mechanisms in Bovine Aorta." In ASME 2010 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2010. http://dx.doi.org/10.1115/sbc2010-19366.
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Rupture of vascular tissue in the circulatory system under non-impact loading is involved in potentially life threatening events such as Marfan’s syndrome or rupture of small renal veins during shock wave lithotripsy. The rupture mechanisms are not well-understood. The complexity of the artery wall precludes the use of rupture theories invented for metals or for fibered composites with a homogeneous matrix. Artery tissue is composed of ground material, smooth muscle cells, elastin and collagen. The collagen fibers, which are generally circumferentially oriented, are the load carrying material after large deformations. Clark and Glagov [1] propose that the media of an elastic artery is built of musculo-elastic fascicles made up of a layer of circumferentially oriented SMC that lie parallel and between two elastin lamellae. Between the elastin sheets of adjacent elements are interspersed collagen fiber bundles.
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Chow, Ming-Jay, Raphaël Turcotte, and Katherine Yanhang Zhang. "Elastin in the Arterial ECM: Interactions With Collagen and the Mechanical Properties After Elastin Degradation." In ASME 2013 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/sbc2013-14257.
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Elastin and collagen are the main structural components in the extracellular matrix (ECM) that contribute to the anisotropic and hyperelastic passive mechanical behavior of elastic arteries. It is commonly accepted that the elastin fibers support most of the load at the onset of stretching while collagen fiber recruitment and the transition to collagen bearing the load occurs at higher pressures [1]. Various diseases lead to changes in the ECM, for example in aortic aneurysm there is reduced elastin, excess aged collagen, and fragmentation of the elastic lamellae [2]. Likewise hypertension has been shown to increase arterial collagen and wall thickness with increased stiffness [3]. Improving our knowledge of how the ECM structure affects the mechanical behavior of arteries can provide insights to disease progression and better treatment methods.
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Koch, Ryan G., Alkiviadis Tsamis, Antonio D’Amore, William R. Wagner, and David A. Vorp. "A Custom Image-Based Analysis Tool for Quantifying Elastin and Collagen Fiber Micro-Architecture in the Wall of the Human Aorta From Multi-Photon Microscopy Images." In ASME 2013 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/sbc2013-14482.
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The two primary load-bearing components of the connective fiber micro-architecture of aorta are the proteins elastin and collagen. The structure of elastin and collagen fibers is important to support the proper function of the aorta, and alteration of the quantity and/or arrangement of these fibers can lead to mechanical and functional changes associated with aortic disease. Therefore, an adequate quantification of the micro-architecture of elastin and collagen fibers in the aortic wall would provide insight into the influence of micro-architecture on the biomechanical response of the aorta in health and disease.
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Le, Victoria, Hiromi Yanagisawa, and Jessica Wagenseil. "Characterization of Cardiac Function and Arterial Mechanics During Early Postnatal Development in Fibulin-5 Null Mice." In ASME 2013 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/sbc2013-14282.
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Fibulin-5 is an extracellular matrix protein that interacts with other proteins during a complex process that results in elastic fiber formation from the elastin precursor, tropoelastin [1]. Elastic fibers are an important component of tissues requiring elasticity, including large arteries, lungs and skin. In mice lacking fibulin-5 ( Fbln5−/−), these tissues contain disorganized elastic fibers and exhibit decreased elasticity [2]. The phenotype of Fbln5−/− mice is similar to that of humans with cutis laxa, a connective tissue disorder characterized by loose skin and narrow arteries with reduced compliance.
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Espinosa, Gabriela, Lisa Bennett, William Gardner, and Jessica Wagenseil. "The Effects of Extracellular Matrix Protein Insufficiency and Treatment on the Stiffness of Arterial Smooth Muscle Cells." In ASME 2013 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/sbc2013-14131.
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Increased arterial stiffness is directly correlated with hypertension and cardiovascular disease. Stiffness of the conducting arteries is largely determined by the extracellular matrix (ECM) proteins in the wall, such as collagen and elastin, produced by the smooth muscle cells (SMCs) found in the medial layer. Elastin is deposited as soluble tropoelastin and is later crosslinked into elastin fibers. Newborn mice lacking the elastin protein ( Eln−/−) have increased arterial wall stiffness and SMCs with altered proliferation, migration and morphology [1]. Vessel elasticity is also mediated by other ECM proteins, such as fibulin-4. Elastic tissue, such as lung, skin, and arteries, from fibulin-4 deficient ( Fbln4−/−) mice show no decrease in elastin content, but have reduced elasticity due to disrupted elastin fibers [2]. Arteries from both elastin and fibulin-4 deficient mice have been previously studied, but the mechanical properties of their SMCs have not been investigated. Recent experiments comparing arterial SMCs from old and young animals suggest that mechanical properties of the SMCs themselves may contribute to changes in wall stiffness [3]. Hence, we investigated the stiffness of isolated arterial SMCs from elastin and fibulin-4 deficient mice using atomic force microscopy (AFM). In addition, we studied the effects of two elastin treatments on the mechanical properties of SMCs from Eln+/+ and Eln−/− mice. Differences between the treatments may elucidate the importance of soluble versus crosslinked elastin on single cell stiffness.
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Qiu, Weiguo, Joseph Cappello, and Xiaoyi Wu. "Fabrication of Genetically Engineered Silk-Elastin-Like Protein Polymer Fibers." In ASME 2008 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2008. http://dx.doi.org/10.1115/sbc2008-190980.
Full textAbstract:
Micro- and submicro-diameter protein fibers are fundamental building blocks of extra- and intra-cellular matrices, providing structural support, stability and protection to cells, tissues and organism [1]. Fabricating performance fibers of both naturally derived and genetically engineered proteins has been extensively pursued for a variety of biomedical applications, including tissue engineering and drug delivery [2]. Silk-elastin-like proteins (SELPs), consisting of tandemly repeated polypeptide sequences derived from silk and elastin, have been biosynthesized using recombinant DNA technique [3]. Their potential as a biomaterials in the form of hydrogels continues to be explored [4, 5]. This study will focus on the fabrication of robust, micro-diameter SELP fibers as biomaterials for tissue engineering applications.
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Majumdar, Arnab, Ascanio D. Araujo, Eunice Yi, Matthew Nugent, and Bela Suki. "Distribution Of Fragments During Elastase Digestion Of Elastin Fibers." In American Thoracic Society 2011 International Conference, May 13-18, 2011 • Denver Colorado. American Thoracic Society, 2011. http://dx.doi.org/10.1164/ajrccm-conference.2011.183.1_meetingabstracts.a5789.
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Zou, Yu, and Katherine Yanhang Zhang. "Experimental and Theoretical Study of Bovine Aorta and its Elastin." In ASME 2008 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2008. http://dx.doi.org/10.1115/sbc2008-193054.
Full textAbstract:
Blood vessels are complex organs with hierarchical ultrastructures. Different kinds of structural supporting fibers, such as collagen and elastin fibers, are cross-linked in a three-dimensional manner to provide stiffness of the tissue. Elastin networks endow blood vessels critical mechanical properties, and are essential to accommodate deformations encountered during physiological functions. Many Pathological conditions involve significant changes in elastin. Therefore it is important to fully characterize and understand the mechanical properties of aorta and its elastin networks. Here we studied, both experimentally and theoretically, the mechanical responses of bovine aorta and its elastin under biaxial loading.
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Stephen, Beth, Theresa A. Good, and L. D. Timmie Topoleski. "Change in Mechanical Response of Arterial Elastin due to Glycation." In ASME 2012 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/sbc2012-80087.
Full textAbstract:
Collagen and elastin are the primary load-bearing components of arteries. Elastin is a low strength, highly elastic, fibrous material and collagen is a stiffer material, generally present as wavy fibers when unstretched. Together, they account for the material response of arteries under tensile load. Arteries, and other soft tissues, exhibit a two-part material response to tensile load. There is an initial low stiffness response at low stretch followed by a high stiffness response at higher stretch. It has been proposed that the low stiffness response is dominated by the elastin in the material and the high stiffness response is dominated by collagen [1]. The elastin accounts for the initial low stiffness response of the material, until the wavy collagen fibers straighten and become engaged, at which point the material transitions to its higher stiffness response. It is important to understand the role of the individual collagen and elastin components and how they contribute to the overall mechanical response of the arteries. Further, it is important to understand how specific biochemical processes that occur with age and disease affect the mechanical response of the individual collagen and elastin components and consequently the overall mechanical response of the arteries. This knowledge will increase our understanding of arterial mechanical response and how this response changes arterial function in health and disease.
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Hill, Michael R., and Anne M. Robertson. "Abrupt Recruitment of Medial Collagen Fibers in the Rabbit Carotid Artery." In ASME 2011 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2011. http://dx.doi.org/10.1115/sbc2011-53641.
Full textAbstract:
Elastin and collagen are dominant passive load bearing proteins in the artery wall. An accepted hypothesis is that during extension of the vessel, the highly distensible elastin bears most of the load at low stretch, while increasing amounts of the less distensible medial collagen fibers uncrimp and thus bear increasing load as the overall tissue stretch increases [1]. Whether or not the collagen fibers are gradually recruited beginning at an infinitesimal stretch or at a finite stretch remains unresolved.
Reports on the topic "Elastin fibers"
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Glushko, E. Ya, and A. N. Stepanyuk. Pneumatic photonic crystals: properties and application in sensing and metrology. [б. в.], 2018. http://dx.doi.org/10.31812/123456789/2875.
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A pneumatic photonic crystal i.e. a medium containing regularly distributed gas-filled voids divided by elastic walls is proposed as an optical indicator of pressure and temperature. The indicator includes layered elastic platform, optical fibers and switching valves, all enclosed into a chamber. We have investigated theoretically distribution of deformation and pressure inside a pneumatic photonic crystal, its bandgap structure and light reflection changes depending on external pressure and temperature.
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Glushko, E. Ya, and A. N. Stepanyuk. Optopneumatic medium for precise indication of pressure over time inside the fluid flow. Астропринт, 2018. http://dx.doi.org/10.31812/123456789/2874.
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In this work, a gas-filled 1D elastic pneumatic photonic crystal is proposed as an optical indicator of pressure which can unite several pressure scales of magnitude. The indicator includes layered elastic platform, optical fibers and switching valves, all enclosed into a chamber. We have investigated the pneumatic photonic crystal bandgap structure and light reflection changes under external pressure. At the chosen parameters the device may cover the pressure interval (0, 10) bar with extremely high accuracy (1 μbar) for actual pressures existing inside the biofluid systems of biological organisms. The size of the indicator is close to 1 mm and may be decreased. The miniaturized optical devices considered may offer an opportunity to organize simultaneous and total scanning monitoring of biofluid pressure in different parts of the circulatory systems.
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Issa, Mohsen. Effect of Early-Age Concrete Elastic Properties on Fatigue Damage in PCC Pavements Containing Fibers. Illinois Center for Transportation, December 2017. http://dx.doi.org/10.36501/0197-9191/17-025.
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Slaughter, William S., J. L. Sanders, and Jr. A Model for Load-Transfer from an Embedded Fiber to an Elastic Matrix. Fort Belvoir, VA: Defense Technical Information Center, August 1990. http://dx.doi.org/10.21236/ada228466.
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Nguyen, Ba Nghiep, and Joshua Paquette. EMTA?s Evaluation of the Elastic Properties for Fiber Polymer Composites Potentially Used in Hydropower Systems. Office of Scientific and Technical Information (OSTI), August 2010. http://dx.doi.org/10.2172/992373.
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Pullammanappallil, Pratap, Haim Kalman, and Jennifer Curtis. Investigation of particulate flow behavior in a continuous, high solids, leach-bed biogasification system. United States Department of Agriculture, January 2015. http://dx.doi.org/10.32747/2015.7600038.bard.
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Recent concerns regarding global warming and energy security have accelerated research and developmental efforts to produce biofuels from agricultural and forestry residues, and energy crops. Anaerobic digestion is a promising process for producing biogas-biofuel from biomass feedstocks. However, there is a need for new reactor designs and operating considerations to process fibrous biomass feedstocks. In this research project, the multiphase flow behavior of biomass particles was investigated. The objective was accomplished through both simulation and experimentation. The simulations included both particle-level and bulk flow simulations. Successful computational fluid dynamics (CFD) simulation of multiphase flow in the digester is dependent on the accuracy of constitutive models which describe (1) the particle phase stress due to particle interactions, (2) the particle phase dissipation due to inelastic interactions between particles and (3) the drag force between the fibres and the digester fluid. Discrete Element Method (DEM) simulations of Homogeneous Cooling Systems (HCS) were used to develop a particle phase dissipation rate model for non-spherical particle systems that was incorporated in a two-fluid CFDmultiphase flow model framework. Two types of frictionless, elongated particle models were compared in the HCS simulations: glued-sphere and true cylinder. A new model for drag for elongated fibres was developed which depends on Reynolds number, solids fraction, and fibre aspect ratio. Schulze shear test results could be used to calibrate particle-particle friction for DEM simulations. Several experimental measurements were taken for biomass particles like olive pulp, orange peels, wheat straw, semolina, and wheat grains. Using a compression tester, the breakage force, breakage energy, yield force, elastic stiffness and Young’s modulus were measured. Measurements were made in a shear tester to determine unconfined yield stress, major principal stress, effective angle of internal friction and internal friction angle. A liquid fludized bed system was used to determine critical velocity of fluidization for these materials. Transport measurements for pneumatic conveying were also assessed. Anaerobic digestion experiments were conducted using orange peel waste, olive pulp and wheat straw. Orange peel waste and olive pulp could be anaerobically digested to produce high methane yields. Wheat straw was not digestible. In a packed bed reactor, anaerobic digestion was not initiated above bulk densities of 100 kg/m³ for peel waste and 75 kg/m³ for olive pulp. Interestingly, after the digestion has been initiated and balanced methanogenesis established, the decomposing biomass could be packed to higher densities and successfully digested. These observations provided useful insights for high throughput reactor designs. Another outcome from this project was the development of low cost devices to measure methane content of biogas for off-line (US$37), field (US$50), and online (US$107) applications.