Literatura académica sobre el tema "Mixed fibrils"
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Artículos de revistas sobre el tema "Mixed fibrils"
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Mendler, M., S. G. Eich-Bender, L. Vaughan, K. H. Winterhalter y P. Bruckner. "Cartilage contains mixed fibrils of collagen types II, IX, and XI." Journal of Cell Biology 108, n.º 1 (1 de enero de 1989): 191–97. http://dx.doi.org/10.1083/jcb.108.1.191.
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The distribution of collagen XI in fibril fragments from 17-d chick embryo sternal cartilage was determined by immunoelectron microscopy using specific polyclonal antibodies. The protein was distributed throughout the fibril fragments but was antigenically masked due to the tight packing of collagen molecules and could be identified only at sites where the fibril structure was partially disrupted. Collagens II and IX were also distributed uniformly along fibrils but, in contrast to collagen XI, were accessible to the antibodies in intact fibrils. Therefore, cartilage fibrils are heterotypically assembled from collagens II, IX, and XI. This implies that collagen XI is an integral component of the cartilage fibrillar network and homogeneously distributed throughout the tissue. This was confirmed by immunofluorescence.
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Thakur, Garima, Miodrag Micic, Yuehai Yang, Wenzhi Li, Dania Movia, Silvia Giordani, Hongzhou Zhang y Roger M. Leblanc. "Conjugated Quantum Dots Inhibit the Amyloidβ(1–42) Fibrillation Process". International Journal of Alzheimer's Disease 2011 (2011): 1–15. http://dx.doi.org/10.4061/2011/502386.
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Nanoparticles have enormous potential in diagnostic and therapeutic studies. We have demonstrated that the amyloid beta mixed with and conjugated to dihydrolipoic acid- (DHLA) capped CdSe/ZnS quantum dots (QDs) of size approximately 2.5 nm can be used to reduce the fibrillation process. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) were used as tools for analysis of fibrillation. There is a significant change in morphology of fibrils when amyloidβ(1–42) (Aβ(1–42)) is mixed or conjugated to the QDs. The length and the width of the fibrils vary under modified conditions. Thioflavin T (ThT) fluorescence supports the decrease in fibril formation in presence of DHLA-capped QDs.
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Birk, D. E., J. M. Fitch, J. P. Babiarz, K. J. Doane y T. F. Linsenmayer. "Collagen fibrillogenesis in vitro: interaction of types I and V collagen regulates fibril diameter". Journal of Cell Science 95, n.º 4 (1 de abril de 1990): 649–57. http://dx.doi.org/10.1242/jcs.95.4.649.
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The small-diameter fibrils of the chick corneal stroma are heterotypic, composed of both collagen types I and V. This tissue has a high concentration of type V collagen relative to other type I-containing tissues with larger-diameter fibrils, suggesting that heterotypic interactions may have a regulatory role in the control of fibril diameter. The interactions of collagen types I and V were studied using an in vitro self-assembly system. Collagens were purified from lathyritic chick embryos in the presence of protease inhibitors. The type V collagen preparations contained higher molecular weight forms of the alpha 1(V) and alpha 2(V) chains constituting 60–70% of the total. Rotary-shadow electron micrographs showed a persistence of a small, pepsin-sensitive terminal region in an amount consistent with that seen by electrophoresis. In vitro, this purified type V collagen formed thin fibrils with no apparent periodicity, while type I collagen fibrils had a broad distribution of large diameters. However, when type I collagen was mixed with increasing amounts of type V collagen a progressive and significant decrease in both the mean fibril diameter and the variance was observed for D periodic fibrils. The amino-terminal domain of the type V collagen molecule was required for this regulatory effect and in its absence little diameter reducing activity was observed. Electron microscopy using collagen type-specific monoclonal antibodies demonstrated that the fibrils formed were heterotypic, containing both collagen types I and V. These data indicate that the interaction of type V with type I collagen is one mechanism modulating fibril diameter and is at least partially responsible for the regulation of collagen fibril formation.
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Boothroyd, Stephen, Alberto Saiani y Aline F. Miller. "Formation of Mixed Ionic Complementary Peptide Fibrils". Macromolecular Symposia 273, n.º 1 (noviembre de 2008): 139–45. http://dx.doi.org/10.1002/masy.200851320.
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Accardi, Fabrizio, Valentina Papa, Anna Rita Capozzi, Gian Luca Capello, Laura Verga, Cristina Mancini, Eugenia Martella et al. "A Rare Case of Systemic AL Amyloidosis with Muscle Involvement: A Misleading Diagnosis". Case Reports in Hematology 2018 (2018): 1–5. http://dx.doi.org/10.1155/2018/9840405.
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Muscle involvement in AL amyloidosis is a rare condition, and the diagnosis of amyloid myopathy is often delayed and underdiagnosed. Amyloid myopathy may be the initial manifestation and may precede the diagnosis of systemic AL amyloidosis. Here, we report the case of a 73-year-old man who was referred to our center for a monoclonal gammopathy of undetermined significance (MGUS) diagnosed since 1999. He reported a progressive weakness of proximal muscles of the legs with onset six months previously. Muscle biopsy showed mild histopathology featuring alterations of nonspecific type with a mixed myopathic and neurogenic involvement, and the diagnostic turning point was the demonstration of characteristic green birefringence under cross-polarized light following Congo red staining of perimysial vessels. Transmission electron microscopy (TEM) confirmed amyloid fibrils around perimysial vessels associated with collagen fibrils. A stepwise approach to diagnosis and staging of this disorder is critical and involves confirmation of amyloid deposition, identification of the fibril type, assessment of underlying amyloidogenic disorder, and evaluation of the extent and severity of amyloidotic organ involvement.
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Cerofolini, Linda, Enrico Ravera, Sara Bologna, Thomas Wiglenda, Annett Böddrich, Bettina Purfürst, Iryna Benilova et al. "Mixing Aβ(1–40) and Aβ(1–42) peptides generates unique amyloid fibrils". Chemical Communications 56, n.º 62 (2020): 8830–33. http://dx.doi.org/10.1039/d0cc02463e.
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Hilman, A., T. Karo-karo, Azhari, H. Sakdiah, N. A. Salma y I. Pangestu. "Hydrolysis of alkaline treatment and characterization of cellulose fibrils from processing waste of bengkoang water-soluble polysaccharide". IOP Conference Series: Earth and Environmental Science 977, n.º 1 (1 de junio de 2022): 012087. http://dx.doi.org/10.1088/1755-1315/977/1/012087.
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Abstract Cellulose fibrils are insoluble dietary fibres in the processing waste of bengkoang water-soluble polysaccharides (WSP). The researcher has investigated the characterization of chemical and morphological properties of WSP bengkoang in previous studies. However, the processing waste of the insoluble dietary fibres from WSP bengkoang still needs to be studied. This research aim is to hydrolyze and characterize the cellulose fibrils from bengkoang water-soluble polysaccharides. The results showed that the crude fibres assisted with alkaline treatment would lead to the swollen thread and remove materials like soluble and insoluble lignin to become cellulose fibrils. The morphology of natural fibres has mixed with starch from the processing waste of bengkoang water-soluble polysaccharides. Meanwhile, the cellulose fibrils look clear with a dimension of around 10–14 μm. The FTIR graph shows a degradation in the quantum of linking materials allows in the fibres due to alkaline treatment. The raw fibres characteristic peak does not appear due to alkaline hydrolisis treatment. The peak between 1200 and 1300 cm-1 which decreases due to alkaline treatment is mainly responsible for the wax, lignin, pectin, and other impurities components. The color degree of cellulose fibrils were indicate due to the removal of other impurities and non-cellulosic components.
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Dieriks, Birger Victor, Blake Highet, Ania Alik, Tracy Bellande, Taylor J. Stevenson, Victoria Low, Thomas I.-H. Park et al. "Human pericytes degrade diverse α-synuclein aggregates". PLOS ONE 17, n.º 11 (18 de noviembre de 2022): e0277658. http://dx.doi.org/10.1371/journal.pone.0277658.
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Parkinson’s disease (PD) is a progressive, neurodegenerative disorder characterised by the abnormal accumulation of α-synuclein (α-syn) aggregates. Central to disease progression is the gradual spread of pathological α-syn. α-syn aggregation is closely linked to progressive neuron loss. As such, clearance of α-syn aggregates may slow the progression of PD and lead to less severe symptoms. Evidence is increasing that non-neuronal cells play a role in PD and other synucleinopathies such as Lewy body dementia and multiple system atrophy. Our previous work has shown that pericytes—vascular mural cells that regulate the blood-brain barrier—contain α-syn aggregates in human PD brains. Here, we demonstrate that pericytes efficiently internalise fibrillar α-syn irrespective of being in a monoculture or mixed neuronal cell culture. Pericytes cleave fibrillar α-syn aggregates (Fibrils, Ribbons, fibrils65, fibrils91 and fibrils110), with cleaved α-syn remaining present for up to 21 days. The number of α-syn aggregates/cell and average aggregate size depends on the type of strain, but differences disappear within 5 five hours of treatment. Our results highlight the role brain vasculature may play in reducing α-syn aggregate burden in PD.
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Sugimoto, Yasushi, Yoshiki Kamada, Yuhei Tokunaga, Hiroshi Shinohara, Mitsuharu Matsumoto, Takahiro Kusakabe, Takatoshi Ohkuri y Tadashi Ueda. "Aggregates with lysozyme and ovalbumin show features of amyloid-like fibrils". Biochemistry and Cell Biology 89, n.º 6 (diciembre de 2011): 533–44. http://dx.doi.org/10.1139/o11-041.
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The interaction of egg-white lysozyme with N-ovalbumin, the native form of egg-white ovalbumin with the denaturation temperature, Tm, of 78 °C, was investigated by the inhibition of lysozyme muramidase activity, differential scanning calorimetry, and circular dichroism assay as indicators. Signals for the interaction were the most prominent when the mixture of lysozyme and N-ovalbumin was co-heated at 72 °C, slightly lower than the Tm of N-ovalbumin. The interaction was also marked when unheated lysozyme was mixed with N-ovalbumin preheated at 72 °C. Moreover, the mixture rapidly formed fibrous precipitates, which were positive for thioflavin T fluorescent emission, a marker for the amyloid fibril formation. Also electron microscopic observation exhibited features of fibrils. The interaction potency of ovalbumin was ascribed to the tryptic fragment ILELPFASGT MSMLVLLPDE VSGLEQLESIINFEK (residues 229–263), derived from the 2B strands 2 and 3 of ovalbumin. From lysozyme, on the other hand, the chymotryptic peptide RNRCKGTDVQAW (residues 112–123), including cluster 6, and the chymotryptic/tryptic peptide GILQINSRW (residues 54–62), including cluster 3, were responsible for the interaction with N-ovalbumin. Interestingly, this nonamer peptide was found to have the ability to self-aggregate. To the authors knowledge, this may be the first report to document the possible involvement of dual proteins in the formation of amyloid-like fibrils.
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Buchanan, L. E., J. K. Carr, A. M. Fluitt, A. J. Hoganson, S. D. Moran, J. J. de Pablo, J. L. Skinner y M. T. Zanni. "Structural motif of polyglutamine amyloid fibrils discerned with mixed-isotope infrared spectroscopy". Proceedings of the National Academy of Sciences 111, n.º 16 (18 de febrero de 2014): 5796–801. http://dx.doi.org/10.1073/pnas.1401587111.
Texto completoTesis sobre el tema "Mixed fibrils"
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Miranda, Centeno Cristian Arturo y Moreno Marco Eduardo Rado. "Propuesta de concretos reforzados con fibras de acero y cemento puzolánico para la construcción de pavimentos rígidos en la región de Apurímac". Bachelor's thesis, Universidad Peruana de Ciencias Aplicadas (UPC), 2019. http://hdl.handle.net/10757/628106.
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La finalidad de la investigación realizada en este documento es presentar el concreto reforzado con fibras de acero como alternativa de solución para la construcción de pavimento rígido. La necesidad de mejorar la calidad de los pavimentos rígidos frente a los problemas recurrentes de fisuración, optimizar costos, aumentar la calidad y optimizar los materiales para mejorar la sostenibilidad ambiental y social, impulsa el estudio e investigaciones sobre distintos aditivos que se agregan al concreto como también el tipo de refuerzo que lo complementa.
Este documento se enfocará en realizar una propuesta de concretos reforzados con fibra de acero y cemento puzolánico para la construcción de pavimento rígido comparando las propiedades físicas y mecánicas de las mezclas y así obtener la mezcla más eficiente que cumpla las condiciones del expediente técnico para así realizar la aplicación en un tramo del proyecto de pavimentación en la provincia de Grau del departamento de Apurímac.The purpose of the research carried out in this document is to present concrete reinforced with steel fibers as technical solution for the construction of concrete pavement an alternative solution for the construction of rigid pavement. In order to save costs per cubic meter per square meter of pavement and optimize raw material so increase quality and optimize materials to improve environmental and social sustainability, encourages the study and research on different chemical addition that are added to the concrete as well as the type of reinforcement that complements it. This document will focus on making a proposal of reinforced concrete with steel fiber and pozzolanic cement for the construction of rigid pavement by comparing the physical and mechanical properties of the mixtures and thus obtain the most efficient mixture that meets the conditions of the technical file in order to perform the application in a section of the paving project in the province of Grau of the department of Apurímac.
Tesis
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Ju, Min. "Optimisation de la protection des réseaux optiques de nouvelle génération". Thesis, Avignon, 2018. http://www.theses.fr/2018AVIG0226/document.
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La tolérance aux pannes est une propriété très importante des réseaux optiques de nouvelle génération. Cette thèse aborde la conception des mécanismes de protection contre des pannes liées à la défaillance d’une fibre optique ou à une catastrophe naturelle. Deux systèmes de protection classiques, à savoir la protection par des cycles préconfigurés(p-cycles) et la protection du chemin de secours, sont étudiés pour atteindre une efficacité de protection élevée, tout en considérant le coût de l’équipement optique,la consommation d’énergie et l’utilisation de la ressource spectrale. Ces problèmes de survivabilité sont d’abord formulés en utilisant la programmation linéaire en nombres entiers (PLNE), et ensuite résolus soit par algorithmes heuristiques, soit par une approche de décomposition.La panne d’une seule fibre optique est le scénario le plus courant. Nous allons donc considérer d’abord des pannes liées à la défaillance d’une fibre optique dans les réseaux optiques multi-débit. Pour réduire le coût des transpondeurs, un système de protection par p-cycles de longueur adaptable et peu coûteux est proposé. Spécifiquement, les p cycles de longueur limitée sont conçus pour utiliser un débit approprié en fonction du coût du transpondeur et de la portée de transmission. Un modèle de programmation linéaire en nombres entiers (PLNE) sans énumération des cycles candidats est formulé pour générer directement les p-cycles de coût dépenses d’investissement minimum. De plus, un algorithme GPA (Graph Partitioning in Average) et un algorithme d’estimation des nombres de cycles (EI) sont développés pour rendre le modèle PLNE plus efficace au niveau du temps de calcul. En ce qui concerne la consommation d’énergie des réseaux optiques élastiques résilients,nous proposons d’utiliser un schéma de p-cycles dirigés, efficaces en énergie,pour protéger le trafic asymétrique. En raison de l’avantage de distinguer du volume de trafic dans les deux directions, les p-cycles dirigés consomment peu d’énergie en attribuant de créneaux ou slots du spectre et des formats de modulation différents à chaque direction.Un modèle PLNE est formulé pour minimiser la consommation d’énergie totale sous contraintes de génération du cycle dirigée, d’allocation de spectre, d’adaptation de modulation et de capacité de protection. Pour le passage à l’échelle, le modèle PLNE est décomposé en deux sous-problèmes: une méthode d’énumération de cycles améliorée et un modèle PLNE simplifié pour la sélection des cycles. Nous avons montré que les p-cycles dirigés obtiennent une meilleure performance comparant les p-cyclesiii non-dirigés pour le trafic asymétrique en termes de la consommation d’énergie et de l’utilisation du spectre.Afin d’améliorer l’efficacité d’utilisation du spectre dans réseaux optiques élastiques, une protection par p-cycles (SS-p-cycle) à spectre partagé est proposée. Les SS-p-cycles permettent de réduire l’utilisation du spectre et le taux de fragmentation spectrale en exploitant un partage de spectre spécial entre plusieurs p-cycles ayant des liens communs.Les modèles PLNE est conçus dans les cas "sans" ou "avec" conversion spectrale afin de minimiser l’utilisation du spectre. Ces modèles peuvent obtenir la solution optimale pour un petit réseaux optiques élastiques, et une heuristique efficace est développée pour résoudre les instances à grande échelle. Les résultats de simulations montrent que les SS-p-cycles ont des avantages significatifs pour réduire l’utilisation de la ressource spectrale et la défragmentation des fréquence. De plus, la conversion du spectre aide les SS-p-cycles à acquérir une meilleure utilisation du spectreNetwork survivability is a critical issue for optical networks to maintain resilience against network failures. This dissertation addresses several survivability design issues against single link failure and large-scale disaster failure in optical networks. Twoclassic protection schemes, namely pre-configured Cycles (p-Cycle) protection and path protection, are studied to achieve high protection capacity efficiency while taking intoaccount the equipment cost, power consumption and resource usage. These survivable network design problems are first formulated by mathematical models and then offered scalable solutions by heuristic algorithms or a decomposition approach.We first consider single link failure scenario. To cut the multi-line rates transponderscost in survivable Mixed-Line-Rate (MLR) optical networks, a distance-adaptive andlow Capital Expenditures (CAPEX) cost p-cycle protection scheme is proposed withoutcandidate cycle enumeration. Specifically, path-length-limited p-cycles are designed touse appropriate line rate depending on the transponder cost and transmission reach.A Mixed Integer Linear Programming (MILP) model is formulated to directly generate the optimal p-cycles with the minimum CAPEX cost. Additionally, Graph Partitioning in Average (GPA) algorithm and Estimation of cycle numbers (EI) algorithm are developed to make the proposed MILP model scalable, which are shown to be efficient.Regarding the power consumption in survivable Elastic Optical Networks (EONs),power-efficient directed p-cycle protection scheme for asymmetric traffic is proposed.Owing to the advantage of distinguishing traffic amount in two directions, directedp-cycles consume low power by allocating different Frequency Slots (FSs) and modulation formats for each direction. An MILP model is formulated to minimize total power consumption under constraints of directed cycle generation, spectrum assignment,modulation adaptation and protection capacity allocation. To increase the scalability, the MILP model is decomposed into an improved cycle enumeration and a simplified Integer Linear Programming (ILP) model. We have shown that the directedp-cycles out perform the undirected p-cycles in terms of power consumption and spectrum usage.In order to improve the spectrum usage efficiency in p-cycle protection, a SpectrumShared p-cycle (SS-p-cycle) protection is proposed for survivable EONs with and without spectrum conversion. SS-p-cycles permit to reduce spectrum usage and Spectrum Fragmentation Ratio (SFR) by leveraging potential spectrum sharing among multiplep-cycles that have common link(s). The ILP formulations are designed in both cases of with and without spectrum conversion to minimize the spectrum usage of SS-p-cycleswhich can obtain the optimal solution in small instance, and a time-efficient heuristic algorithm is developed to solve large-scale instances. Simulation results show that SSp-cycles have significant advantages on both spectrum allocation and defragmentation efficiency, and the spectrum conversion does help SS-p-cycle design to acquire better spectrum utilization
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Bologna, Sara. "Expression and characterization of human proteins involved in neurological disorders". Doctoral thesis, 2019. http://hdl.handle.net/2158/1179619.
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My Ph.D. research project, entitled “Expression and characterization of human proteins involved in neurodegenerative diseases”, was focused on the application of molecular biology and proteomics methodologies to prepare samples of proteins involved in neurodegenerative diseases. The target proteins were α-synuclein (α-syn) and the amyloid-beta peptides (Aβ), involved in the pathogenesis of Parkinson’s disease (PD) and Alzheimer’s disease (AD), respectively. The aim of my research activity was the optimization of the expression and purification of the neurodegeneration-associated proteins to carry out the following projects: “NMR analysis of the aggregation kinetics of Aβ1-40”, to reveal aggregation mechanisms of Aβ1-40 and to develop a kinetic model describing the formation of oligomeric and fibrillary species. “NMR analysis of the assembly of Aβ42: Aβ40 mixed fibrils”. This project is in the frame of an integrative study aimed to characterize the structure of the mixed fibrils (containing Aβ1-42 and Aβ1-40 peptides) at atomic detail. “Development of a protein aggregation assays for the diagnosis of synucleinopathies” This project was focused on the development of a protocol tool for the diagnosis PD, dementia with Lewy bodies (DLB) and multiple system atrophy (MSA) based on α-synuclein aggregation assays (SAA-seeding aggregation assays) starting from aliquots of Cerebrospinal fluid (CSF). Study of the interaction between alpha-synuclein and human biofluids components” This project concerned the study of the interaction of α-synuclein with lipoproteins, proteins and other constituents of CSF and plasma.
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H, Chien-Hsun y 何建勳. "Fibrin Glue Mixed with Gelatin Particles for Articular Cartilage Tissue Engineering". Thesis, 2012. http://ndltd.ncl.edu.tw/handle/7rnudv.
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碩士國立臺北科技大學
生物科技研究所
100
Articular cartilage serves as an essential role in normal joint function. However, since the self-repair ability of damaged articular cartilage is poor, an artificial system of repairing damaged articular cartilage becomes a great challenge. Two potential components of scaffold have been selected in this work. Firstly, fibrin glue is studied because of its excellent biocompatibility and biodegradability. Another component, gelatin, has also been discussed because it is able to support cell culturing and adhesion. In this study, fibrin glue mixed with gelatin particles have been prepared to evaluate the possibility as the scaffold for articular cartilage tissue engineering. According to the measurement taken in vitro using WST-1 and LDH assay, the scaffold offers good biocompatibility. Glycosaminoglycans analyze shows that fibrin glue-gelatin particles would effectively promote extrancellular matrix (ECM) secretion. The gene expressions and histological staining demonstrate that the cells stayed in fibrin glue-gelatin particles could maintain chondrogenic phenotype and inhibit ECM degradation. The evidences mentioned above indicate that fibrin glue-gelatin particles would be a promising scaffold for articular cartilage tissue engineering.
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Chou, Cheng-Hung y 周正鴻. "Fibrin glue mixed with gelatin/hyaluronic acid/chondroitin-6-sulfate tri-copolymer for articular cartilage tissue engineering". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/75259871056535859757.
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博士國立臺灣大學
醫學工程學研究所
96
Articular cartilage provides functions of lubrication to shear stress and protection from compressive force, but it has poor ability to repair itself after suffering damage. The advanced method of tissue engineering is developed and used to maintain cell functions for tissue regeneration. Autologous fibrin glue has been demonstrated as a potential scaffold with very good biocompatibility for neocartilage formation. However, fibrin glue has been reported not to provide enough mechanical strength, but with many growth factors to interfere the tissue growth. Gelatin/hyaluronic acid/chondroitin-6-sulfate (GHC6S) tricopolymer sponge has been prepared as scaffold for cartilage tissue engineering and showed very good results, but problems of cell seeding and cell distribution troubled the researchers. In this study, GHC6S particles would be added into the fibrin glue to provide better mechanical strength, better cell distribution, and easier cell seeding, which would be expected to improve cartilage regeneration in vitro. Porcine cryo-precipitated fibrinogen and thrombin prepared from prothrombin activated by 10% CaCl2 solution were used in two groups. One is the fibrin glue group in which porcine chondrocytes were mixed with thrombin–fibrinogen solution, which was then converted into fibrin glue. The other is GHC6S-fibrin glue in which GHC6S particles were added into the thrombin-fibrinogen solution with porcine chondrocytes. After culturing for 1-2 weeks, the chondrocytes cultured in GHC6S-fibrin glue showed a round shape with distinct lacuna structure and showed positive in S-100 protein immunohistochemical stain. The related gene expressions of tissue inhibitor of metalloproteinases-1, matrix metalloproteinase- 2, MT1-MMP, aggrecan, decorin, type I, II, X collagen, interleukin-1 b, transforming growth factor-b 1 (TGF-b1), and Fas-associating death domain were checked by real-time PCR. Total GAGs and sulfated GAGs were also quantified by p-dimethylaminobenzaldehyde reaction and 1,9- dimethymethylene blue (DMMB) assay, respectively. The results indicated that the chondrocytes cultured in GHC6S-fibrin glue would effectively promote extracellular matrix (ECM) secretion and inhibit ECM degradation. The evidence could support that GHC6S-fibrin glue would be a promising scaffold for articular cartilage tissue engineering.
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Chou, Cheng-Hung. "Fibrin glue mixed with gelatin/hyaluronic acid/ chondroitin-6-sulfate tri-copolymer for articular cartilage tissue engineering". 2008. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-2407200815575800.
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Liao, Chien-Kai y 廖健凱. "Transplantation of Olfactory Ensheathing Cells Combined with Fibrin Glue Mixed with/without Neurotrophin-3 in the T8-Transected Rat Spinal Cord Improves Functional Recovery". Thesis, 2004. http://ndltd.ncl.edu.tw/handle/62455401723135303619.
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碩士國立陽明大學
解剖暨細胞生物學研究所
92
Spinal cord transection results in permanent deficits involving complete paralysis and sensory loss below the level of lesion. Olfactory ensheathing cells (OECs) are regarded as the best therapeutic agent for use in the repair of spinal cord injury. We successfully established OEC with over 95% cells expressing GFAP, S100 and p75NGFR. Neurotrophin-3 (NT-3), a putative neurotrophic factor in the rubro- and cortico-spinal tracts has been shown to effectively promote regeneration of damaged axons into the spinal cord. However, its expression is low in OEC. The present work therefore examines the effects of OEC transplant combined with fibrin glue mixed with NT3 on functional recovery after T8-transection. OEC, prelabelled with 5-bromo-2-deoxyuridine or green fluorescence protein, were mixed with fibrin glue with/without NT-3 and transplanted into the transected spinal cord. Behavior tests (BBB and CBS) and were conducted every other week. By post operation , significant functional recovery in hind limb usage occurred in OECs or OECs + NT3 transplanted rats groups compared with control groups, transplanted with HBSS alone(p<0.05 ANOVA). However, none of the animals demonstrated coordinated fore and hind limb movement or the ability to bear weight on the hind limbs. The immunhistochemistry showed that, the T7 level of OECs + NT3 groups presented more neurofilament and serotonin marker than control groups. At the transected site, neurofilament and serotonin marker can be found in the OECs + NT3 groups but not in the control groups. In conclusion, our results demonstrated that (1) The primary cultured cells of OECs from olfactory bulb can present the GFAP, S100 and p75NGFR. (2) Fibrin glue enwrapped OECs with/without NT-3 transplanted rats showed significantly higher functional recovery in hind limb. (3) Fibrin glue enwrapped OECs with/without NT-3 transplanted rats facilitated the newly regenerated axon to pass the transected site.
Libros sobre el tema "Mixed fibrils"
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C, Chamis C. y Lewis Research Center, eds. Interlaminar fracture toughness: Three-dimensional finite-element modeling for end-notch and mixed-mode flexure. [Cleveland, Ohio: National Aeronautics and Space Administration, Lewis Research Center, 1985.
Buscar texto completoCapítulos de libros sobre el tema "Mixed fibrils"
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Divakaran, U. y A. Dutta. "Critical Behaviour of Mixed Fibres with Uniform Distribution". En Modelling Critical and Catastrophic Phenomena in Geoscience, 515–20. Berlin, Heidelberg: Springer Berlin Heidelberg, 2006. http://dx.doi.org/10.1007/3-540-35375-5_21.
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Yoshikawa, Tomotaka, Yoshiaki Kikuchi, Shohei Noda y Akihiro Oshino. "Shear Characteristics of Geomaterials Mixed with Fibrous Wood Chip and Converter Steelmaking Slag". En Lecture Notes in Civil Engineering, 171–81. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-16-0077-7_17.
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Salma, I., G. Salms, A. Skagers, M. Pilmane y L. Feldmane. "Autologous Fibrin Mixed with Biphasic Calcium Phosphate Bioceramic Granules Activates Encapsulation in Soft Tissue Environment". En IFMBE Proceedings, 178–81. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-34197-7_47.
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Srinivasan, Dr Daya y Dr Shoba Narayan. "NANO SILVER FLUORIDE – A POTENTIAL NON-INVASIVE SOLUTION TO TREAT DENTAL CARIES". En Emerging Trends in Oral Health Sciences and Dentistry. Technoarete Publishers, 2022. http://dx.doi.org/10.36647/etohsd/2022.01.b1.ch039.
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Dental decay is one of the paediatric disorders requiring early intervention and can lead to tooth loss if not treated. Antimicrobial medicines work by altering the nature of pathogenic microorganisms in dental biofilms to reduce cariogenic activity. When fluoride is mixed with silver, which has an antibacterial effect, its antimicrobial efficiency is boosted. Silver diamine Fluoride has been shown to aid in the prevention of tooth decay, with the only drawback being an unsightly black discoloration. Silver nanoparticles with an appropriate surface range and a huge proportion of surface atoms have attracted attention due to their distinguishing characteristics. Although Silver diamine Fluoride has altered dentin collagen shape and Nano silver fluoride has normal collagen fibrils, both show intrafibrillar remineralization. Nano silver fluoride is a topical agent which can be safely, and cost-effectively applied to children for treating dental caries.
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"NANO SILVER FLUORIDE - A POTENTIAL NON-INVASIVE SOLUTION TO TREAT DENTAL CARIES". En Emerging Trends in Oral Health Sciences and Dentistry. Technoarete Publishers, 2022. http://dx.doi.org/10.36647/etohsd/2022.01.b1.ch012.
Texto completoResumen
Dental decay is one of the paediatric disorders requiring early intervention and can lead to tooth loss if not treated. Antimicrobial medicines work by altering the nature of pathogenic microorganisms in dental biofilms to reduce cariogenic activity. When fluoride is mixed with silver, which has an antibacterial effect, its antimicrobial efficiency is boosted. Silver diamine Fluoride has been shown to aid in the prevention of tooth decay, with the only drawback being an unsightly black discoloration. Silver nanoparticles with an appropriate surface range and a huge proportion of surface atoms have attracted attention due to their distinguishing characteristics. Although Silver diamine Fluoride has altered dentin collagen shape and Nano silver fluoride has normal collagen fibrils, both show intrafibrillar remineralization. Nano silver fluoride is a topical agent which can be safely, and cost-effectively applied to children for treating dental caries.
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"Cellulosic Fibres". En The Chemistry of Textile Fibres, 25–66. 2a ed. The Royal Society of Chemistry, 2015. http://dx.doi.org/10.1039/9781782620235-00025.
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Cellulose is the most abundant naturally occurring polymer, accounting for about a third of all vegetable matter. It is the main structural component of the cell walls of plants, though it does not occur in a pure form, often being mixed with lignins, pectins and other complex organic compounds. Cellulose fibres can be obtained from the stem, leaf or seed of a plant and whilst fibres from each of these parts are produced, by far the most common is cotton, obtained from the seed. The chapter describes in detail the chemistry of cotton cellulose in terms of its constitution and chemical reactions, but in addition it describes the complex morphology of cotton fibres that contribute to the unique properties cotton fibres possess. The ways in which the properties of cotton fibres and fabrics can be modified chemically to improve performance are explained. Contemporary issues such as GM cotton and “green” cotton are also discussed. The chapter also describes other cellulosic fibres such as flax, jute, bamboo and ramie, indicating the chemical and physical processes necessary to extract the fibres from the plant. Finally, the alginates, chitin and chitosan, which are closely related to cellulosic fibres, are discussed, with particular reference to their healing properties and uses in wound dressings.
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Alshawish, Eman. "Perspective of Women about Her Body after Hysterectomy". En Fibroids [Working Title]. IntechOpen, 2020. http://dx.doi.org/10.5772/intechopen.94260.
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Hysterectomy is the most common major gynecological operation in worldwide and Arabic countries. However, the psychological, physical and sexual consequences of hysterectomy are conflicting and the findings are mixed. While, some studies report that patients have experience greater improvement in their mental health, sexual desire and overall satisfaction. Others show that patients report various negative outcomes, with detrimental effects on sexual functioning being the main concern. My previous study demonstrated that hysterectomy had significantly negative effects on patients’ body image, self-esteem, and identified common meanings and themes associated with hysterectomy stressors, which includes difficulties or limitations in physical and psychological aspects perceived by patients after hysterectomy. In this chapter, author will expand that discuss in details the different factors that influence the perspective of women about body after hysterectomy. Mainly, author will focus on religious, cultural, and psycho-social aspects. All of these factors are interacting with health status of women and effect the situation and productivity of women in her family and culture. Different strategy need to be adopted in order to overcome this problem using evidence and analysis of our Arabic culture and structure. Recommendation of study to health care profession as physician, nurses, midwives and other health care provider to be aware of these potential problematic issues in order to provide a competent health care for women based of her needs.
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Skinner, H. Catherine W., Malcolm Ross y Clifford Frondel. "What Is an Inorganic Fiber?" En Asbestos and Other Fibrous Materials. Oxford University Press, 1989. http://dx.doi.org/10.1093/oso/9780195039672.003.0004.
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Fibers are everywhere around us. They are essential parts of the human body, our hair, for example; the threads in our clothing, natural or synthetic; the insulation in our houses. Natural fibers have been useful to humans for more than ten thousand years. They were mixed with clay before firing to strengthen and reinforce pottery vessels, making them more durable. Textiles that combined the fibers of flax and asbestos were known in ancient times for their seemingly magical resistance to fire and decay. It was industrialization, however, that caused a dramatic increase in the use of natural inorganic or mineral fibers. By the late nineteenth century asbestos had become an important commodity with a variety of commercial applications. It served as insulation to control heat generated by engines and, because of its incombustibility, as a fire retardant in its more recent general use as building insulation. Asbestos fibers are found worldwide in many products: as reinforcement in cement water pipes and the inert and durable mesh material used in filtration processes of chemicals and petroleum, for example. However, asbestos is not the only inorganic fiber in use today. Synthetic inorganic fibers abound. Glass fibers have replaced copper wire in some intercontinental telephone cables. Fiberglas (a trade name) has become the insulation material of choice in construction. Carbon and graphite fiber composites are favored materials for tennis racket frames and golf clubs. Fibrous inorganic materials have become commonplace in our everyday lives. As the use of inorganic fibers increased, there were some indications that fibers might be hazardous to our health. Since the first century A.D. it was suspected that asbestos might be the cause of illness among those who mined and processed the material. Asbestosis, a debilitating and sometimes fatal lung disorder, was documented and described in the nineteenth century. Within the last 25 years, lung cancer and mesothelioma have also been linked to asbestos exposure among construction and textile workers, as well as others exposed to dusts containing asbestos fibers. Although the etiology and specific mechanisms that give rise to these two cancers are not yet understood, concern for the health of exposed workers led the governments of the United States and other countries to specify the maximum allowable concentrations of asbestos in the ambient air of the workplace.
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van Gijn, Daniel R. y Jonathan Dunne. "The cranial nerves". En Oxford Handbook of Head and Neck Anatomy, editado por Susan Standring y Simon Eccles, 125–56. Oxford University Press, 2022. http://dx.doi.org/10.1093/med/9780198767831.003.0004.
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There are 12 pairs of cranial nerves that are individually named and numbered using Roman numerals. Only some cranial nerves are mixed in function, i.e. they carry both sensory and motor fibres; others are purely sensory or motor and some may also carry pre- or post-ganglionic parasympathetic fibres. They pass through foramina in the base of the skull and are the olfactory (through cribriform plate to the nasal cavity), optic (through the optic foramen to the eye), oculomotor (through the cavernous sinus and superior orbital fissure to supply the eye), trochlear (as per oculomotor), trigeminal (three main branches that pass through the superior orbital fissure, foramen rotundum and foramen ovale, respectively), abducens (as per oculomotor), facial (through stylomastoid foramen to supply muscles of facial expression), vestibulocochlear (through the internal acoustic canal to control balance and hearing), glossopharyngeal, vagus, accessory (all pass through the jugular foramen) and hypoglossal (through the hypoglossal canal to control movements of the tongue) nerves.
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Bui, Huyen, Mazhar Hussain y Daniel Levacher. "Recycling of Tropical Natural Fibers in Building Materials". En Natural Fiber [Working Title]. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.102999.
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This chapter deals with the reuse and recycling of tropical natural fibers and their potential valorization in construction materials in a context of circular economy and sustainable development. These fibers constitute large volumes of fibrous waste resulting from various agro-food industries worldwide. Depending on their intrinsic qualities and properties (physical and mechanical), they can be reused as reinforcing material in cementitious mixes (hardened mixes) or mixes with soils (raw mixes) and molded into a prismatic brick-like shape. These bricks constitute construction materials that have mechanical and other characteristics. A whole methodology specific to the development of such materials and their optimization is presented. It includes the preparation, characterization, cutting of the fibers to the desired length and the making of the mixtures. This is followed by optimization (fibers distribution), control and quality of the fiber-reinforced material. Two examples illustrate the application of this methodology: a reinforced mortar based on coconut fibers (hardened cementitious mix) and a green brick based on sediment and oil palm fibers.
Actas de conferencias sobre el tema "Mixed fibrils"
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Rohatgi, A., J. N. Baucom, W. R. Pogue y J. P. Thomas. "Microstructure-Property Relation in a Liquid Crystalline Polymer-Carbon Nanofiber Composite". En ASME 2005 International Mechanical Engineering Congress and Exposition. ASMEDC, 2005. http://dx.doi.org/10.1115/imece2005-80045.
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Microstructure-property relationship is being examined in a polymer matrix composite system consisting of vapor grown carbon nanofibers (VGCF) mixed in a thermotropic liquid crystalline polymer (LCP) matrix. These nanocomposites show an inherent hierarchical structuring, which we hope to utilize in the development of multifunctional structure-conduction composites with improved performance. Among unfilled polymers, extruded LCPs show relatively high strength and high stiffness that have been attributed in the literature to the preferential molecular alignment along the extrusion direction and the hierarchical nature of LCPs. Further, as is typical for polymers, LCPs have poor thermal and electrical conductivity relative to metals. By contrast, carbon nanofibers are known to possess high strength, high stiffness and high conductivity in the axial direction. It is expected that the combination of the extrusion process and the similarity of the length-scales of LCP fibrils and carbon nanofibers will lead to improved axial alignment of both phases within the nanocomposite filaments. This simultaneous alignment of the LCP matrix and that of the carbon nanofibers is expected to lead to interesting mechanical and conductive behavior in the nanocomposite filaments through hierarchical interactions at the nanometer to micrometer scale levels. Carbon nanofibers, 60-150 nm in diameter, were mixed with Vectra A950 LCP and the mixture was extruded as 0.5–2 mm diameter filaments. Nanocomposite filaments with 1%, 2%, 5% and 10 wt.% VGCF were characterized via tensile testing and fractography. The tensile modulus, failure strength and strain-to-failure were found to be sensitive to filament diameter, carbon nanofiber content and extrusion process. There was a noticeable increase in mechanical performance with decreasing filament diameter irrespective of carbon nanofiber content. Fracture surfaces showed hierarchical features from nanometer to micrometer scale and processing defects in the form of voids. The results of this research will be used to fabricate composite components that exploit structural hierarchy from nano-to macro-scale.
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Kusznier, Jacek, Maciej Zajkowski, Łukasz Budzyński y Damian Tyniecki. "Ring optical mixer for LED with truncated surfaces". En 17th Conference on Optical Fibres and Their Applications, editado por Jan Dorosz y Ryszard S. Romaniuk. SPIE, 2017. http://dx.doi.org/10.1117/12.2271828.
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Jen, C. J. y Y. L. Chiu. "PLATELET DEPOSITION ONTO FIBRIN-COATED SURFACES UNDER FLOW CONDITIONS". En XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644219.
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Fibrin solubilized in NaBr/acetic acid was used to coat glass tubes. Platelet deposition on fibrin-coated surface and release from these adherent platelets were studied in an in vitro flow system. When a mixed suspension of washed platelets and red cells flowed through a fibrin-coated glass tube, only platelets deposited onto the fibrin-coated surface. The density of adhered platelets increased with flow time and decreased with distance from the tube inlet. The adhesion rate increased with increasing shear rates from 45 s−1 to 180 s−1. This adhesion process appears to fit a diffusion-limited mathematical model. Comparing with glass and other protein-coated surfaces such as collagen, fibrinogen, or albumin coated surfaces, the number of adhered platelets per unit area decreased in the following order: collagen > fibrin> fibrinogen > glass > albumin. On the other hand, the degree of release reaction from these platelets decreased by another order: collagen > glass > fibrinogen > fibrin. We observed little release from platelets that were in contact with a fibrin-coated surface. Our results support that platelets specifically adhere to fibrin-coated surface and that this interaction does not induce platelet release.
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Da Costa Santos, Ana Caroline y Paul Archbold. "Mechanical Properties and Fracture Energy of Concrete Beams Reinforced with Basalt Fibres". En 4th International Conference on Bio-Based Building Materials. Switzerland: Trans Tech Publications Ltd, 2022. http://dx.doi.org/10.4028/www.scientific.net/cta.1.316.
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Fibre-reinforced concrete (FRC) is widely employed in the construction industry, with assorted fibre types being used for different applications. Typically, steel fibres give additional tensile strength to the mixture, while flexible fibres may be used in large sections, such as floor slabs, to control crack width and to improve the handling ability of precast sections. For many reasons, including durability concerns, environmental impact, thermal performance, etc, alternatives to the currently available fibres are being sought. This study examines the potential of using basalt fibres, a mineral and natural material, as reinforcement of concrete sections in comparison to steel fibres and plain concrete mix. Mixes were tested containing 0.5% and 1.0% of basalt fibres measuring 25mm length, 0.5% of the same material with 48mm length and steel fibres measuring 50mm by 0.05%, 0.1%, 0.15% and 0.2% of the concrete volume. For the mechanical performance analysis, the 3-point bending test was led and the fracture energy, Young’s modulus and tensile strength in different moments of the tests were calculated. When compared to the control mixtures and the steel-fibre-reinforced concrete, the mixes containing basalt had a reduction in their elastic modulus, representing a decrease in the concrete brittleness. At the same time, the fracture energy of the mixtures was significantly increased with the basalt fibres in both lengths. Finally, the flexural strength was also higher for the natural fibre reinforced concrete than for the plain concrete and comparable to the results obtained with the addition of steel fibres by 0.15%.
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Nichol, Jason W., Bruce R. Simon y Stuart K. Williams. "One-Dimensional Mixed Poroelastic-Transport-Swelling (MPHETS) Finite Element Models for Soft Tissues". En ASME 2000 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2000. http://dx.doi.org/10.1115/imece2000-2485.
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Abstract A hydrated soft tissue structure can be viewed as a poroelastic transport model, or specifically a porous, incompressible, fibrous solid matrix, which is saturated by an incompressible fluid (water) containing both positively and negatively charged species. We present a one-dimensional finite element model (FEM), derived from a Mixed-Poro-HyperElastic-Transport-Swelling (MPHETS)model. This FEM can be used to model various soft tissues, such as arteries, and provides a powerful tool to study coupled ion transport under various mechanical loading and water/ species flow conditions.
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Simon, B. R., S. K. Williams, J. Liu, J. W. Nichol, P. H. Rigby y M. V. Kaufmann. "Equivalent Mixed “PHETS” and “MPHETS” Poroelasttc-Transport-Swelling Finite Element Models for Soft Biological Tissues". En ASME 1999 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 1999. http://dx.doi.org/10.1115/imece1999-0459.
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Abstract A soft hydrated tissue structure can be viewed as a “PETS” (poroelastic-transport-swelling) model, i.e., as a continuum composed of an incompressible porous solid (fibrous matrix with fixed charge density, FCD) that is saturated by a mobile incompressible fluid (water) containing mobile positively (p) and negatively (m) charged species. Previously, we described two PETS models — a “semi-mixed” porohyperelastic PHETS model (Simon et al. 1998) and a “fully mixed” MPHETS model (Simon et al. 1999) using FEMs (finite element models) that included geometric and material nonlinearity and coupled electrical/chemical/mechanical transport of the fluid and charged species. Here, we demonstrate the equivalence of the PHETS and MPHETS formulations that are useful when the solid and fluid materials are incompressible and the electrical-chemical potential and mechanical-osmotic pressure fields are discontinuous at material interfaces.
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Sonebi, Mohammed, P. Thiele, A. Abdalqader, Leonid I. Dvorkin, Nataliya Lushnikova y J. Khatib. "Effect of Viscosity Modifying Agent on the Performance of Hybrid Bio-Based Concrete". En 4th International Conference on Bio-Based Building Materials. Switzerland: Trans Tech Publications Ltd, 2022. http://dx.doi.org/10.4028/www.scientific.net/cta.1.491.
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An experimental investigation was conducted in order to study the water absorption, mechanical performance, thermal properties and durability of hybrid hemp-rapeseed composite materials. The hybrid composite material is made with 50% hemp shives and 50% rapeseed fibres. The purpose of this study is to investigate the influence of the incorporation of viscosity modifying agent (VMA) on hybrid concrete. Four mixes were made for: shuttered walls and roof insulation with and without VMA. The water absorption of the hybrid composite fibres was, first, measured. The compressive strengths of these mixes at 7 and 28 d were then determined in order to compare the mechanical behaviour of the hybrid composite materials made with VMA. In addition, the capillary absorption and coefficient of thermal conductivity were also measured. The results revealed that VMA improved the performance of the hybrid concrete.
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van Hierden, Naomi Zahra, Florent Gauvin, S. S. Lucas, T. A. M. Salet y Henricus Jozef Hubertus Brouwers. "Use of Hemp Fibres in 3D Printed Concrete". En 4th International Conference on Bio-Based Building Materials. Switzerland: Trans Tech Publications Ltd, 2022. http://dx.doi.org/10.4028/www.scientific.net/cta.1.758.
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The use of fibres as reinforcement of 3D printed concrete is widely known and applicable in many situations. However, most of the applied fibres are not produced from renewable resources. Natural fibres are commonly considered as an ecological alternative for these fibres. In order to contribute to improvement of the sustainability of 3D printed concrete, natural fibres such as hemp can replace these synthetic fibres. The objective of this study is therefore to study the possibilities of adding hemp fibres for 3D printing purposes. Due to the comparable properties of hemp and synthetic fibres, natural fibres tend to be suitable for printing purposes. Mixes are made at laboratory scale using batches of 1 – 3 kg. The study examines the effect of adding hemp fibres for the mechanical and fresh state properties of hemp-based concrete. Mechanical properties from bending tests and direct tensile tests show comparable properties of mortars containing hemp fibres and mortars containing synthetic fibres. The fresh state behaviour of the designed concrete mix showed promising and comparable results for a mix based on 0.5wt% of hemp fibres. One of the major issues regarding the use of natural fibres is the irregularity and high water uptake of the fibres. Due to its high hydrophilicity natural hemp fibres take up much water and can therefore degrade. For this study the effect of water uptake did not have much influence on the mixing and printing purposes. By printing a wall element on laboratory scale the use of hemp fibre-reinforced 3D concrete is validated.
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Da Costa Santos, Ana Caroline y Paul Archbold. "Experimental Investigation on the Fracture Energy and Mechanical Behaviour of Hemp and Flax Fibre FRC Compared to Polypropylene FRC". En 4th International Conference on Bio-Based Building Materials. Switzerland: Trans Tech Publications Ltd, 2022. http://dx.doi.org/10.4028/www.scientific.net/cta.1.326.
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Natural fibre reinforced concrete is been studied for many years as a more sustainable option to current reinforced concrete used in industry. The most common fibre materials currently adopted are steel, glass and synthetic fibres. Apart from the high oxidation and cost, their environmental impact is a serious issue as they are petroleum-based materials. This study assesses the feasibility of replacing polypropylene fibre with hemp and flax fibres. According to the inventory of carbon and energy (ICE) the embodied energy of polypropylene (PP) is 95.4MJ/kg and the embodied carbon is 4.98kgCO2/kg during its lifetime. It represents approximately 3 times more than the estimated values for vegetable fibres. For this, Different concrete mixtures reinforced by 0.5% to 1.0% of hemp, flax and polypropylene fibres were tested, and their post-crack flexural tensile strength, elastic’s modulus, compressive strength and fracture energy were evaluated. The mixtures containing hemp fibres presented properties equivalent to those containing polypropylene under the same proportion. Although both compressive and tensile strength were reduced for the mixes containing flax fibres, the Young’s modulus was 49% smaller and could be an interesting approach for applications that require better elasticity from the concrete, such as industrial floors and structures that may be submitted to impact.
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Robbins, K. C. y I. Boreisha. "COVALENT Mr ∼92,000 HYBRID PLASMINOGEN ACTIVATOR DERIVED FROM THE PLASMIN FIBRIN-BINDING DOMAIN AND THE TISSUE PLASMINOGEN ACTIVATOR CATALYTIC DOMAIN". En XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643938.
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A covalent hybrid plasminogen activator was prepared from the sulfhydryl forms of the NH2-terminal A chain of human plasmin (Pln^) containing the fibrin-binding domain, and the COOH-terminal B chain of tissue plasminogen activator (t-PAB) containing the catalytic domain. The PlnA (SH)2 and t-PAB(SH) chains were mixed in a 1:1 molar ratio, and hybridization was allowed to proceed at 4 °C for 6 days. The covalent PlnA-t-PAB hybrid activator was isolated from the mixture by a two-step affinity chromatography method, with L-lysine-substituted Sepharose and Zn-chelated agarose. The protein yield of purified hybrid was 10% with a major component (77%) of Mr ∼92,000. The covalent PlnA-t-PAB hybrid activator, contained 1 mol of each chain; after reduction, it gave the two parent chains, PlnA and t-PAA, also shown to be present by double immunodiffusion. The specific plasminogen activator activity, with soluble fibrin, and the specific amidolytic activity, of the purified covalent hybrid activator was determined to be 200,000 IU/mg of protein, about 40% of the specific activity of the parent t-PA. In a fibrin clot lysis assay, the covalent hybrid activator and t-PA have similar specific fibrinolytic activities, 500,000 IU/mg of protein; however, the clot lysis time curves were not parallel. The binding of the covalent PlnA-t-PAB hybrid activator and t-PA to forming fibrin were found to be similar; at physiological fibrinogen concentrations, binding of both activators to forming fibrin was about 90%.