Academic literature on the topic 'Water soluble fibres'
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Journal articles on the topic "Water soluble fibres"
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Boguń, M., T. Mikołajczyk, G. Szparaga, and A. Kurzak. "Water-soluble nanocomposite sodium alginate fibres." Fibers and Polymers 11, no. 3 (June 2010): 398–405. http://dx.doi.org/10.1007/s12221-010-0398-9.
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Sun, R., J. M. Fang, L. Mott, and J. Bolton. "Fractional Isolation and Characterization of Polysaccharides from Oil Palm Trunk and Empty Fruit Bunch Fibres." Holzforschung 53, no. 3 (May 10, 1999): 253–60. http://dx.doi.org/10.1515/hf.1999.043.
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Summary The polysaccharides in oil palm trunk fibre and empty fruit bunch (EFB) fibre were fractionated into cold water solubles, hot water solubles, 1% NaOH solubles, and 17.5% NaOH soluble fractions. Cellulose (approximately 42%) and hemicelluloses (approximately 33%) were the major polysaccharides in the palm trunk fibre and EFB fibre. Extractions of the lignified fibres with cold water, hot water, and 1% NaOH produced the hemicellulosic fractions, which were enriched in xylose and glucose and to a lesser extent, arabinose-, galactose-, mannose-, rhamnose-, and ribose-containing polysaccharides, together with noticeable amounts of associated lignin (4.5–31.2%). Further extraction of the delignified fibre residues with aqueous 17.5% NaOH removed the hemicellulosic fractions, which were strongly enriched in xylose-containing polysaccharides and relatively free of associated lignin (0.3–0.7%). Eight phenolic acids and aldehydes, including p-hydroxybenzoic acid, p-hydroxybenzaldehyde, vanillic acid, syringic acid, vanillin, syringaldehyde, p-coumaric acid, and ferulic acid, were detected in the mixtures of alkaline nitrobenzene oxidation of associated lignin in all the sixteen polysaccharide fractions. The results obtained showed that hemicelluloses in the cell walls of oil palm trunk and EFB fibres, are mainly bonded with lignin by syringyl units.
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Bouaziz, Amine, Manel Masmoudi, Amel Kamoun, and Souhail Besbes. "Optimization of Insoluble and Soluble Fibres Extraction fromAgave americanaL. Using Response Surface Methodology." Journal of Chemistry 2014 (2014): 1–13. http://dx.doi.org/10.1155/2014/627103.
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Experimental design methodology was used to determine significant factors affecting the extraction yield of soluble and insoluble fibres fromAgave americanaL. and in second time to find optimum conditions leading to the highest yield. Results clearly indicated that the temperature, the powder to water (P/W) ratio, and the agitation speed were the most important factors influencing fibres extraction yield which increased with temperature, P/W ratio, and agitation speed. Ionic strength affected significantly soluble fibre extraction yield and was the most important factor among nonsignificant ones influencing insoluble fibres extraction yield. Then, a Box-Behnken design was carried out to maximise fibres extraction. Selected optimal conditions were temperature: 90°C; P/W ratio: 0.1625; agitation speed: 400 rpm; and ionic strength: 1.5 g/L. These conditions yielded 93.02% and 80.46% of insoluble and soluble fibres, respectively. Concentrates showed high fibres purity and good functional properties.
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Suresh, Harsha, Vincent Ho, and Jerry Zhou. "Rheological Characteristics of Soluble Fibres during Chemically Simulated Digestion and their Suitability for Gastroparesis Patients." Nutrients 12, no. 8 (August 17, 2020): 2479. http://dx.doi.org/10.3390/nu12082479.
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Dietary fibres are an integral part of a balanced diet. Consumption of a high-fibre diet confers many physiological and metabolic benefits. However, fibre is generally avoided by individuals with gastrointestinal motility disorders like gastroparesis due to increased likelihood of exacerbated symptoms. Low-viscosity soluble fibres have been identified as a possible source of fibre tolerable for these individuals. The aim of this study is to determine the rheological properties of 10 common commercially available soluble fibres in chemically simulated digestive conditions and evaluate their suitability for individuals with mild to moderate gastroparesis, a gastric motility disorder. Rheological testing under neutral condition (distilled water pH 7) and chemically simulated gastric digestion were evaluated to determine the yield point and relative viscosity of each fibre. Our results reveal two rheological categories of soluble fibres; pseudoplastic and dilatant. Simulated digestion was shown to significantly alter the yield-points of psyllium husk, iota-carrageenan, beta-glucan, apple-fibre pectin, and inulin. Gum Arabic and partially hydrolysed guar gum showed the lowest viscosities and were not affected under simulated digestion, characteristics that make them potential candidate fibres for patients with gastroparesis. Altogether, our results demonstrate that digestion can have a significant impact on fibre viscosity and should be taken into consideration when evaluating the suitability of fibres for patients with gastric motility disorders.
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Lata Kanyal Butola, Anjali Vaaga, Neelam Gusain, and Karuna Kachhwa. "Aspects of dietary fibre in health and diseases." International Journal of Research in Pharmaceutical Sciences 11, SPL4 (December 21, 2020): 1581–86. http://dx.doi.org/10.26452/ijrps.v11ispl4.4341.
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Dietary fibre is the name collectively given to the indigestible carbohydrates present in foods. These carbohydrates consist of cellulose, gum, pectin and mucilage. Enzymes of gastro-intestinal tracts in humans do not digest these fibres. Plants are the only source of dietary fibre. It is found in grains, vegetables and fruits. Dietary fibre helps to keep the digestive system healthy, and it is vital in reducing the risk of diseases such as coronary heart disease, diabetes, diverticulosis, haemorrhoids and intestinal cancer. Undigested fibres enter the large intestine where bacteria ferments them. Carbon dioxide, nitrogen, hydrogen and short-chain fatty acids are the by-products of the fermentation. Soluble fibre and resistant starch also serve as prebiotic and supports the necessary probiotic for digestive health. In grapes, peas, beans and barley, much of the soluble fibre is extracted. When dissolved in the water, a gel-like substance is formed. Soluble fibre helps to support the growth of friendly bacteria needed to maintain a healthy intestinal system. They also help in slowing down the time taken by the food to pass through the stomach into the small intestine, which helps to slow down the absorption of glucose and controls the blood sugar levels and helps in managing diabetes mellitus and keeps you feeling fuller for a longer time. The diets with high fibre intakes are known to have beneficial health effects as they have water holding capacity, helps in adsorption of organic molecules and facilitates its excretion, hypoglycemic effects and hypercholesterolemic effect. The inclusion of fibre rich food in weight-reducing diets is found to helpful since it provides a feeling of fullness without consumption of excess calories. The present review discusses the definition, nutritional properties of dietary fibre and therapeutic functions of dietary fibres in health and diseases.
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Cameron-Smith, D., G. R. Collier, and K. O'dea. "Effect of soluble dietary fibre on the viscosity of gastrointestinal contents and the acute glycaemic response in the rat." British Journal of Nutrition 71, no. 4 (April 1994): 563–71. http://dx.doi.org/10.1079/bjn19940163.
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The postprandial glycaemic response following a meal is reduced with the addition of soluble dietary fibre. The reductions in the glycaemia are thought to be due largely to increased viscosity of the gastrointestinal (GI) contents retarding digestion and absorption. The aims of the present study were to determine the effect that the GI tract has on the viscosity of meals containing different soluble fibres and to determine whether the glycaemic response of a meal (containing the soluble fibre) was predicted by the viscosity of the digesta in the small intestine. High carbohydrate diets containing 70 g soluble fibre (guar gum, xanthan gum or methylcellulose)/kg or 70 g insoluble fibre (wheat bran)/kg were diluted in water to a final fibre concentration of 18 g/kg. Following dilution the wheat bran diet had no measurable viscosity, while the viscosities of the soluble fibre diets were elevated. When the diets were fed to male Sprague–Dawley rats for 2 weeks the viscosities of the stomach and small intestinal digesta were not predicted by the viscosity of the diets measured before ingestion The action of the GI tract on the viscosity of the soluble fibres was investigatedin vitroby dilution of the diets with acidic and neutralizing solutions, mimicking gastric and duodenal secretions. Dilution of diets with either acidic and neutralizing solutions or saline control significantly lowered the viscosity of all diets, while alterations in the pH of the diets had little impact on the resultant viscosity. When fasted rats were orally administered with the differing diets (0.25 g carbohydrate/kg body weight), the postprandial glucose response was reduced following the soluble-fibre-containing meals when compared with the wheat bran-supplemented meal, although the reduction in glycaemia only reached statistical significance with xanthan supplementation. These results indicate that there are large changes in the viscosity of a meal containing soluble fibre following ingestion, and that dilution of the diet by GI secretions is important in determining the resultant viscosity in the small intestine. Furthermore, the large differences in viscosity of the GI contents following consumption of the diets containing the soluble fibres were not predictive of the postprandial glycaemic response.
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Pablos, Jesús L., Miriam Trigo-López, Felipe Serna, Félix C. García, and José M. García. "Water-soluble polymers, solid polymer membranes, and coated fibres as smart sensory materials for the naked eye detection and quantification of TNT in aqueous media." Chem. Commun. 50, no. 19 (2014): 2484–87. http://dx.doi.org/10.1039/c3cc49260e.
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Bousoulas, J., P. A. Tarantili, and A. G. Andreopoulos. "Resole Resin as Sizing Agent for Aramid Fibres." Advanced Composites Letters 10, no. 5 (September 2001): 096369350101000. http://dx.doi.org/10.1177/096369350101000505.
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A comparative study was made in order to evaluate the interfacial characteristics of treated aramid fibres and epoxy resins. Surface treatment by coating with phenolic resins was performed using the following two systems: a) alkaline aqueous solution of resole resin and b) solution of novolac resin containing hexamethylene-tetramine as cross-linking agent. After these treatments, the modified aramid fibres were used for the preparation of reinforced epoxy specimens. The flexural properties of these specimens were determined and the results were discussed taking into consideration the surface characteristics of the modified fibres, as derived from pull-out tests and contact angle measurements. It was shown that both coatings are adequate to promote interfacial adhesive bonding to epoxy matrices due to the chemical reactivity of phenolic resins to the epoxy matrix as well as to their affinity with the aramid fibre surface. Resole appeared more efficient than novolac as it produces uniform continuous films, shows increased reactivity due to its higher hydroxyl content and can be easily processed because it is soluble in alkaline water solutions.
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Toldrá, F. "Muscle Foods: Water, Structure and Functionality." Food Science and Technology International 9, no. 3 (June 2003): 173–77. http://dx.doi.org/10.1177/1082013203035048.
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Main constituents of skeletal muscle are water, protein, fat, carbohydrate and other soluble compounds. The amount of water is usually found in the range 70-80%. Part of this water is found in free form while the rest is bound to proteins, especially myofibrillar proteins, through charged and polar groups. The amount of immobilised water depends on the available space within the myofibrillar structure and, in fact, the volume of myofibrils is decisive to the water-binding capacity of the muscle. Some variations exist between muscles due to the types of muscle fibres, degree of fibre contraction and pre-rigor pH. The water retention will also depend on the ultimate pH reached after rigor mortis and this will have a strong influence on the activity of muscle enzymes involved in proteolysis and lipolysis during ageing and further processing. Variations may be also expected between animal or fish species and age at slaughter. It is of primary importance to understand metabolic processes in post-mortem muscle as they will directly influence water-binding and thus, the relative amount of drip loss.
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Nierop, K. G. J., and P. Buurman. "Water-soluble organic matter in incipient podzols: accumulation in B horizons or in fibres?" European Journal of Soil Science 50, no. 4 (December 1999): 701–11. http://dx.doi.org/10.1046/j.1365-2389.1999.00263.x.
Full textDissertations / Theses on the topic "Water soluble fibres"
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Kravaev, Plamen, Steffen Janetzko, Thomas Gries, Bong-Gu Kang, Wolfgang Brameshuber, Maike Zell, and Josef Hegger. "Commingling Yarns for Reinforcement of Concrete." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2009. http://nbn-resolving.de/urn:nbn:de:bsz:14-ds-1244040840310-74290.
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Textile reinforced concrete (TRC) is an innovative composite material, which is being intensely and practice-oriented investigated on national and international level. In the last few years this material has gained increasing importance in the field of civil engineering. In the context of the collaborative research project SFB 532 at the RWTH Aachen University, research was carried out to understand and to predict the behaviour of different yarn structures in fine grained concrete. Based on the results, innovative commingling yarns were made of alkali-resistant glass fibres and water soluble PVA. These hybrid yarns have an open structure, which improves the penetration of the textile reinforcement by the concrete matrix. Hence, the load bearing capacity of TRC structural elements was significantly improved. This paper presents a technique for the production of such commingling yarns for concrete applications. The mechanical properties of the new yarns are determined due to tensile stress tests. The bond behaviour of the commingling yarns was investigated by pull-out- and tensile stress tests on TRC-specimens. The results of the different tests are being presented and briefly discussed.
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Al-Asfoor, Husam [Verfasser]. "Effects of Different Feeding Regimes on the Digestibility and Faecal Excretion of Nitrogen, Soluble Carbohydrates and Fibre Fractions in Water Buffaloes kept under Subtropical Conditions / Husam Al-Asfoor." Kassel : Universitätsbibliothek Kassel, 2010. http://d-nb.info/1008601756/34.
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Wong, H. M. "Probing the interactions between iron nutrition, salinity and ultraviolet-B radiation on the physiological responses of wheat (Triticum aestivum L.)." Diss., Lincoln University, 2009. http://hdl.handle.net/10182/1327.
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When plants are exposed to multiple environmental stress factors, one form of stress can affect the response to another stress. This study used seedlings of a new cultivar of wheat(Triticum aestivum L. cv. 1862), grown under factorial combinations of two levels of ultraviolet-B (UV-B)radiation, two salinity regimes and two levels of iron treatment in chelator-buffered nutrient solutions in a growth chamber. A number of morphological and physiological measurements were made. The accumulation of chlorophyll, UVabsorbing compounds and proline in shoots, as well as phytosiderophores (PSs) in root exudates were measured. Feed value measurements included crude protein, water-soluble carbohydrates, acid detergent fibre and Fe in shoots and roots. After 21 days of stress exposure, results showed that Fe deficiency and NaCl stress generally decreased plant growth and function as well as nutritive value, but increased plant biochemical protection traits such as proline accumulation (16.3 fold under salinity stress) and release of PSs (2.4 fold under Fe deficiency). Interestingly, UV-B radiation affected belowground parameters, inducing a 47% reduction in PS release, together with decreasing root DM by 9% and Fe concentration in roots by 7%. When Fe deficiency and NaCl stress were combined, the results showed a decrease in PS release by 3.5 fold compared to unstressed plants. UV-B radiation synergistically increased UV-absorbing compound levels in combination with Fe deficiency, compared to plants grown under optimal Fe levels. This stress combination also resulted in a cumulative effect by decreasing Fe concentration in shoots and roots. However, salt stress did not interact with UV-B radiation for any of the traits measured. In addition, some three-way interactions were noted, with the Fe x NaCl x UV-B stress combination slightly decreasing PS release and resulting in a cumulative effect by decreasing Fe concentration in roots. In conclusion, this study found that aboveground stress factors such as UV-B can affect important aspects of belowground plant function, and that Fe deficiency can interact with UV-B and salinity stress in modifying plant responses to either stress alone.
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Hsuan and 葉瑄. "Antioxidative capacity from in vitro fermentation of water-soluble dietary fibers by rat fecal slurry." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/65549084487742055573.
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碩士中山醫學大學
營養學研究所
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Aim: To investigate the antioxidative ability produced after 48 h in vitro fermentation of konjac glucomannan (KGM), guar gum (GG), xanthan gum (XG), pectin (P), in comparison with control (fiber-free) as negative control and inulin (I) as positive control, by rat fecal slurry. In addition, the changes in fecal microflora profile and the toxicity of culture supernatant to Caco-2 cells were investigated. Method: Fibers (0.1% w/v) and rat fecal slurry (0.5% w/v) were cultured for 24, and 48 h in anaerobic static fermentation system. The culture supernatant was determined for indices of antioxidative ability including trolox-equivalent antioxidative capacity (TEAC), DPPH radical-scavenging ability and iron-binding capacity. The effect of the culture supernatant on cell curvival and H2O2-induced DNA damage of Caco-2 cells were determined. Result: The fermentation of inulin for 24 h produced the greatest TEAC as compared to the control group while that of GG, CA and P for 48 h exerted the greatest effect among groups. The DPPH-scavenging effect was greater in each fiber group as compared to the control after 48 h of fermentation. There was not different in iron-binding capacity among groups at either time point. Pectin and inulin exerted greater promotive effect on fecal bifidobacteria count while KGM stimulated the greatest growth of lactobacillus. Guar gum significantly decreased the growth of clostridia. The fermentation of soluble fiber exerted protective effect on H2O2-induced DNA damage in Caco-2 cells. Inulin group and KGM group exerted the best effect after 24 h and 48 h of fermentation, respectively. Conclusion: The in vitro fermentation of soluble dietary fiber by fecal microflora produced antioxidative substances and reduced the antioxidative damage to Caco-2 cells
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Mutavhatsindi, Tshilidzi Faith. "Effects of fibrolytic enzyme and bacterial inoculants on the fermentation, chemical composition and aerobic stability of ensiled potato hash." Thesis, 2016. http://hdl.handle.net/11602/430.
Full textBooks on the topic "Water soluble fibres"
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Chau, Edwin S. K. The effects of different water-insoluble and soluble cereal fibres on bowel habits, intestinal transit time and colonic microflora activity. Ottawa: National Library of Canada, 1994.
Find full textBook chapters on the topic "Water soluble fibres"
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van Andel, Adriaan C. J., Theo A. Niewold, Bert T. G. Lutz, Marcel W. J. Messing, and Erik Gruys. "The Significance of Non-Protein AA Material in Water-Soluble Bovine AA-Amyloid Fibrils." In Amyloidosis, 169–75. Dordrecht: Springer Netherlands, 1986. http://dx.doi.org/10.1007/978-94-009-4309-4_19.
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Meghwal, Murlidhar, and Ravi-Kumar Kadeppagari. "Dietary Fibers and their Role as Functional Food for Human Health." In Examining the Development, Regulation, and Consumption of Functional Foods, 29–44. IGI Global, 2017. http://dx.doi.org/10.4018/978-1-5225-0607-2.ch002.
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This chapter mainly summarizes the sources of dietary fibers and how they act as functional food for benefiting the human health. Dietary fibers could be soluble and insoluble in water and the major sources are fruits, vegetables, nuts and whole grains. Dietary fibers play role in the control of various disorders like cardiovascular diseases, digestive disorders, diabetes, obesity and colonic cancer. Dietary fibers benefit the human health by acting through various mechanisms in the gastrointestinal tract. According to the WHO recommendations at least 25 g of dietary fiber per day should be consumed. Effect of food processing practices on the physiochemical and functional properties of dietary fibers is also covered in this chapter.
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Johnston, Keith P., and C. T. Lee. "Interfacial Phenomena with Carbon Dioxide Soluble Surfactants." In Green Chemistry Using Liquid and Supercritical Carbon Dioxide. Oxford University Press, 2004. http://dx.doi.org/10.1093/oso/9780195154832.003.0013.
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A fundamental understanding of colloid and interface science for surfactant design in CO2-based systems is emerging on the basis of studies of interfacial tension and surfactant adsorption (da Rocha et al., 1999) along with complementary studies of colloid structure (Chillura-Martino et al., 1996; Meredith and Johnston, 1999; Wignall, 1999) and stability (Meredith and Johnston, 1999; O’Neill, 1997; Yates et al., 1997). The interfacial tension, γ, between a supercritical fluid (SCF) phase and a hydrophilic or lipophilic liquid or solid, along with surfactant adsorption, play a key role in a variety of processes including nucleation, coalescense and growth of dispersed phases, formation of microemulsions and emulsions (Johnston et al., 1999), particle and fiber formation, atomization, foaming (Goel and Beckman, 1995), wetting, adhesion, lubrication, and the morphology of blends and composites (Watkins et al., 1999). The first generation of research involving surfactants in SCFs addressed water/oil (w/o) microemulsions (Fulton and Smith, 1988; Johnston et al., 1989) and polymer latexes (Everett and Stageman, 1978) in ethane and propane (Bartscherer et al., 1995; Fulton, 1999; McFann and Johnston, 1999). This work provided a foundation for studies in CO2, which has modestly weaker van der Waals forces (polarizability per volume) than ethane. Consequently, polymers with low cohesive energy densities and thus low surface tensions are the most soluble in CO2: for example, fluoroacrylates (DeSimone et al., 1992), fluorocarbons, fluoroethers (Singley et al., 1997), siloxanes, and to a lesser extent propylene oxide. Since CO2 is nonpolar (unlike water) and has weak van der Waals forces (unlike lipophilic phases), it may be considered to be a third type of condensed phase. Surfactants with the above types of “CO2-philic” segments and a “CO2-phobic” segment have been used to form microemulsions (Harrison et al., 1994; Johnston et al., 1996), emulsions (da Rocha et al., 1999; Jacobson et al., 1999a; Lee et al., 1999b), and organic polymer latexes (DeSimone et al., 1994) in CO2. Microemulsion droplets are typically 2–10 nm in diameter, making them optically transparent and thermodynamically stable, whereas kinetically stable emulsion droplets and latexes in the range of 200 nm to 10 mm are opaque and thermodynamically unstable.
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Jolivet, Jean-Pierre. "Aluminum Oxides: Alumina and Aluminosilicates." In Metal Oxide Nanostructures Chemistry. Oxford University Press, 2019. http://dx.doi.org/10.1093/oso/9780190928117.003.0009.
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Aluminum is the third most abundant element in Earth’s crust (8.3% in mass), behind oxygen (45.5%) and silicon (27.2%). It forms in nature various oxygenated mineral phases: hydroxides Al(OH)3, oxyhydroxides AlOOH, of which bauxite is the main ore, and oxides, Al2O3, alumina. Corundum, α- Al2O3, is the component of many gems: sapphire (pure Al2O3, perfectly colorless), ruby (red colored due to the presence of Cr3+ ions), and blue sapphire (blue colored by the presence of Ti4+ and Fe2+ ions), among many others. The content of foreign elements substituted for Al3+ ions in these phases accounts for only a small percentage of the total. Aluminum also forms many natural phases in combination with various elements, especially silicon in aluminosilicates, such as feldspars, clays, zeolites, allophanes, and imogolites. The biochemical cycling of the elements involves many soluble complexes of aluminum in natural waters [1, 2]. Aluminum oxides and oxy(hydroxi)des are important materials and nanomaterials used in many fields: for instance, as active phase for adsorption in water treatment; as inert support and active phase in catalysis; as active phase in flame-retardant polymers; as refractory material for laboratory tools and in the ceramics industry; and as abrasives [3, 4]. Alumina Al2O3 is produced in various forms (tubes, balls, fibers, and powders) for numerous industrial uses (laboratory tools, filtration membranes, ball bearings, fine powders as catalysis supports, etc.). The structural chemistry of aluminum oxy(hydroxi)des is rich. There are various hydroxides, Al(OH)3 (gibbsite, also named hydrargillite, bayerite, and some other polytypes such as nordstrandite and doyleite), oxyhydroxides, AlOOH (boehmite and diaspore), and a series of oxides, Al2O3, so-called transition aluminas. These last phases have different degrees of hydration and different degrees of order of the Al3+ cations within the cubic close packing of oxygen atoms according to the temperature at which they have been submitted. They belong to various structural types (γ, δ, θ, η, κ, etc.). These aluminas of huge specific surface areas are usually used in catalysis, especially γ-alumina of spinel crystal structure.
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Mactier, Robert. "Haemodialysis." In Oxford Textbook of Medicine, edited by John D. Firth, 4861–74. Oxford University Press, 2020. http://dx.doi.org/10.1093/med/9780198746690.003.0479.
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Maintenance haemodialysis (HD) is a highly successful treatment for patients with established renal failure and is the default therapy when other renal replacement therapy options are not available. HD uses the countercurrent flow of blood and dialysate through a hollow fibre dialyser to maximize the concentration gradient for diffusive transport of solutes. A hydrostatic gradient across the dialyser membrane induces ultrafiltration (UF) of water and convective transport of solutes by solvent drag. High-flux membranes are standard in most HD centres and are needed to achieve significant removal of middle molecules, of which β2-microglobulin (the cause of dialysis-related amyloid) is the prime example. The technique of haemodiafiltration contributes additional convective removal of fluid and better clearance of middle molecules. The need to secure and maintain reliable vascular access is fundamental to achieving adequate dialysis and maintaining health. An arteriovenous fistula is the preferred option, with fewer complications and longer survival than other access options. For historical and pragmatic reasons, HD is normally provided three times per week. Working definitions of adequacy are based on small-solute—typically urea—removal. The optimal dialysis dose has not been well defined, but minimum targets of delivered dose measured by urea reduction ratio and normalized urea clearance (Kt/V) have been established. The main acute complication of HD is intradialytic hypotension, resulting from an imbalance between the UF rate and the rate of vascular refill. Underlying cardiovascular disease, antihypertensive drugs, autonomic dysfunction, shortened dialysis times, large interdialytic fluid gains, and inaccurate dry-weight assessment all predispose. In the longer term, dialysis-related amyloidosis is a disabling, progressive condition caused by the polymerization of β2-microglobulin within tendons, synovium, and other tissues.
Conference papers on the topic "Water soluble fibres"
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Baker, Brendon M., Nandan L. Nerurkar, Jason A. Burdick, Dawn M. Elliott, and Robert L. Mauck. "Fabrication and Modeling of an Electrospun Tri-Polymer Composite for the Engineering of Fibrous Tissues." In ASME 2008 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2008. http://dx.doi.org/10.1115/sbc2008-193174.
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Aligned, electrospun scaffolds are a useful tool for the engineering of fiber-reinforced tissues (such as tendon, meniscus, and muscle) as they mimic the topography and anisotropy of the native tissue extracellular matrix (ECM) [1]. We have shown that fiber-alignment of slow-degrading poly(ε-caprolactone) (PCL) enhances the organization of newly-formed ECM and improves construct properties [2]. However, one significant drawback to these 3D templates is their small pore size, resulting from tight fiber packing, which hampers cell infiltration. To increase scaffold porosity and thereby accelerate cell ingress, we have recently reported on the fabrication of dual polymer composite scaffolds containing both water-soluble poly(ethylene oxide) (PEO) and PCL fibers [3]. Removal of the sacrificial PEO fibers before seeding improved cell infiltration, but did so at the cost of the overall structural integrity. To further expand the potential properties (mechanics and degradation) of these composite scaffolds, this study introduced a third component (50:50 poly(lactic-co-glycolic acid) (PLGA)) using a newly constructed tri-polymer electrospinning device. We evaluated each polymer singly and when combined into a tri-polymer (3P) fibrous network. To better understand the mechanical response of these composites, we used a hyperelastic, constrained mixture model to assess and predict the response of these composite nanofibrous meshes for a range of compositions.
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Srikar, R., C. M. Megaridis, A. L. Yarin, and A. V. Bazilevsky. "Desorption-Limited Mechanism of Release From Polymer Nanofibers." In ASME 2008 International Manufacturing Science and Engineering Conference collocated with the 3rd JSME/ASME International Conference on Materials and Processing. ASMEDC, 2008. http://dx.doi.org/10.1115/msec_icmp2008-72054.
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This work examines the release of a model water-soluble compound from electrospun polymer nanofiber assemblies. Such release attracts attention in relation with biomedical applications, such as controlled drug delivery. It is also important for stem cell attachment and differentiation on biocompatible electrospun nanofiber scaffolds containing growth factors, which have been encapsulated by means of electrospinning. Typically, the release mechanism has been attributed to solid-state diffusion of the encapsulated compound from the fibers into the surrounding aqueous bath. Under this assumption, a 100% release of the encapsulated compound is expected in a certain (long) time. The present work focuses on certain cases where complete release does not happen, which suggests that solid-state diffusion may not be the primary mechanism at play. We show that in such cases the release rate can be explained by desorption of the embedded compound from nanopores in the fibers, or from the outer surface of the fiber in contact with the water bath. After release, the water-soluble compound rapidly diffuses in water, whereas a release rate is determined by the limiting desorption stage. A model system of Rhodamine 610 fluorescent dye embedded in electrospun monolithic Poly(methylmethacrylate) PMMA or Poly(caprolactone) PCL nanofibers, or in nanofibers electrospun from PMMA/PCL blends, or in core/shell PMMA/PCL nanofibers is studied. Both the experimental results and theory point at the above-mentioned desorption-related mechanism and the predicted characteristic time, release rate, and effective diffusion coefficient agree fairly well with the experimental data. A practically important outcome of this surface release mechanism is that only the compound on the fiber and pore surfaces can be released, whereas the material encapsulated in the bulk cannot be freed within the time scales characteristic of the present experiments (days to months). Consequently, in such cases complete release is impossible. We also demonstrate how the release rate can be manipulated by the polymer content and molecular weight affecting nanoporosity and the desorption enthalpy, as well as by the nanofiber structure (monolithic fibers, fibers from polymer blends and core-shell fibers). In particular, it is shown that by manipulating the above parameters, release times from tens of hours to months can be attained.
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Hao-qiu Li, Guo-ze Wang, and Xin-yong You. "Study on extraction of water soluble dietary fiber from malus asiatica." In 2011 International Conference on Remote Sensing, Environment and Transportation Engineering (RSETE). IEEE, 2011. http://dx.doi.org/10.1109/rsete.2011.5966009.
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Baker, Brendon M., Amy M. Silverstein, Roshan P. Shah, and Robert L. Mauck. "Engineering the Functional Maturation of Nanofiber-Based Human Meniscus Tissue." In ASME 2010 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2010. http://dx.doi.org/10.1115/sbc2010-19685.
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The meniscus is a fibrous tissue essential to healthy knee mechanics. It functions to redirect vertical forces laterally, converting compressive into tensile loads which are taken up by an array of highly organized collagen fibers. Load transmission is not only the operative mode of the meniscus, but is also required for normal development and homeostatic maintenance [1]. With injury, disruption of the aligned collagen fiber architecture impairs function, altering joint loading and initiating osteoarthritis. Toward engineering replacement meniscus tissue, we have investigated scaffolds of aligned electrospun nanofibers that direct cell orientation and provide a suitable microenvironment for the deposition of organized extracellular matrix (ECM) (Fig 1) [2]. In previous work, human meniscus fibrochondrocytes (MFCs) seeded on such scaffolds formed robust ECM with commensurate increases in tensile properties [3]. After 10-weeks of static, free-floating culture, however, mechanical properties still fell short of native tissue values. Over this time course, full-thickness MFC colonization was not observed due to the tight packing of nanofibers, although better infiltrated constructs revealed larger improvements in tensile properties. To accelerate cell ingress, we next explored composite scaffolds containing slow eroding poly(e-caprolactone) (PCL) fibers and water-soluble poly(ethylene oxide) (PEO) fibers that augment pore size when removed (Fig 4A-D) [4]. Based on this precedent, the current study explored two strategies for improving the maturation of MFC-laden nanofibrous constructs: dynamic tensile loading mimicking the in vivo mechanical environment and inclusion of sacrificial PEO fibers to enhance cell infiltration. We hypothesized that dynamic control of the mechanical and material microenvironment would improve matrix production and lead to enhanced mechanical properties.
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Baker, Brendon M., Amy M. Silverstein, and Robert L. Mauck. "Engineering Dense Connective Tissues via Anisotropic Nanofibrous Scaffolds With High Sacrificial Fiber Content." In ASME 2010 First Global Congress on NanoEngineering for Medicine and Biology. ASMEDC, 2010. http://dx.doi.org/10.1115/nemb2010-13371.
Full textAbstract:
Given their ability to dictate initial cell alignment and subsequent matrix organization, aligned electrospun scaffolds are a fitting means for engineering fiber-reinforced, anisotropic tissues such as tendon, ligament, the knee meniscus, and the annulus fibrosus [1–4]. However, one commonly observed limitation of such scaffolds is the relatively slow infiltration rates of surface-seeded cells, where the central thicknesses of constructs cultured for 10 weeks remain devoid of cells [3]. This limitation arises from the tight packing of fibers which yields small pore sizes, thereby hampering cell migration. Towards accelerating cell ingress, we have recently reported on two-polymer composite scaffolds containing both slow eroding poly(ε-caprolactone) (PCL) fibers as well as water-soluble poly(ethylene oxide) (PEO) fibers that serve as space holders during scaffold formation [5]. Removal of these PEO fibers prior to seeding resulted in improved cell infiltration after 3 weeks, but the long-term maturation of such constructs has yet to be characterized. To assess the effect of sacrificial PEO fiber content on construct growth, a triple-jet electrospinning device was employed to generate PCL/PEO scaffolds with PEO fiber fractions ranging from 0 to 60%. After seeding with human meniscus fibrochondrocytes (hMFCs), constructs were clamped in custom grips to maintain strip morphology. The mechanical and biochemical maturation of constructs was assessed over 12 weeks of free swelling culture in a chemically defined medium (CDM), along with cell infiltration and matrix distribution. We hypothesized that enhanced pore size in dual-fiber constructs would lead to not only to a better distribution of cells, but also to larger increases in stiffness resulting from enhanced matrix production and distribution.
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Baker, Brendon M., Giana Montero, and Robert L. Mauck. "Removal of Sacrificial Fibers Enhances Long Term Cell and Matrix Distribution in Aligned Nanofibrous Scaffolds." In ASME 2009 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2009. http://dx.doi.org/10.1115/sbc2009-206856.
Full textAbstract:
Given their ability to dictate initial cell alignment and subsequent matrix organization, aligned electrospun scaffolds are a fitting means for engineering fiber-reinforced, anisotropic tissues such as tendon, ligament, the knee meniscus, and the annulus fibrosus [1–3]. However, one commonly observed limitation of such scaffolds is the relatively slow infiltration rates of surface-seeded cells, where the central thicknesses of constructs cultured for 10 weeks remain devoid of cells [2]. This limitation arises from the tight packing of fibers which yields small pore sizes, thereby hampering cell migration. Towards accelerating cell ingress, we have recently reported on two-polymer composite scaffolds containing both slow eroding poly(ε-caprolactone) (PCL) fibers as well as water-soluble poly(ethylene oxide) (PEO) fibers that serve as space holders during scaffold formation [4]. Removal of these PEO fibers prior to seeding resulted in improved cell infiltration after 3 weeks, but the long term maturation of such constructs has yet to be characterized. To assess the effect of sacrificial PEO fiber content on construct growth, a triple-jet electrospinning device was employed to generate PCL/PEO scaffolds with PEO fiber fractions ranging from 0 to 60%. After seeding with mesenchymal stem cells (MSCs), constructs were clamped in custom grips to maintain strip morphology. The mechanical and biochemical maturation of constructs was assessed over 9 weeks of free swelling culture in a chemically defined medium (CDM), along with cell infiltration and matrix distribution. We hypothesized that enhanced pore size in dual-fiber constructs would lead to not only a better distribution of cells, but also larger increases in stiffness resulting from enhanced matrix production and distribution.
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Guegan, Eric, Tian Davis, Thomas J. Koob, and Yvonne Moussy. "Transport Characteristics of a Novel Local Drug Delivery System Using Nordihydroguaiaretic Acid (NDGA)-Polymerized Collagen Fibers." In ASME 2007 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2007. http://dx.doi.org/10.1115/sbc2007-171428.
Full textAbstract:
Local delivery of a drug in vivo would permit high interstitial drug concentration at the desired location without producing high systemic drug levels. Previous local drug delivery systems have included biodegradable polymer implants, hydrogels, and osmotic pumps [1]. In this paper, we describe a novel local drug delivery system using nordihydroguaiaretic acid (NDGA)-polymerized collagen fibers. NDGA collagen fibers were originally developed for use as biocompatible tendon bioprostheses [2]. The NDGA collagen fibers were loaded with either: dexamethasone, a synthetic glucocorticoid with anti-inflammatory and immunosuppressive activities; or dexamethasone 21-phosphate, a water soluble pro-drug that is converted into dexamethasone in vivo. Dexamethasone was chosen as the loading agent since experiments pairing the loaded fibers with implantable glucose sensors will be performed in the future. This may be useful for preventing inflammation around implantable glucose sensor [3]. This decrease in inflammation is expected to increase glucose sensor function and lifetime. We also determined the diffusion coefficient of dexamethasone and dexamethasone 21-phosphate in the NDGA collagen fiber. In an effort to control the rate of release of dexamethasone, the biocompatible copolymer, polylactic-co-glycolic acid (PLGA) was used to coat the fibers. The information obtained from these experiments is necessary for the future development of an optimal local delivery system of dexamethasone using NDGA collagen fibers in an effort to suppress the inflammatory response around implantable glucose sensors.
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Kluge, Jonathan A., Rudra A. Pampati, Mara L. Schenker, Daniel J. Zhou, John E. Esterhai, David L. Kaplan, and Robert L. Mauck. "Delivery of Active FGF-2 From Mechanically-Stable Biological Nanofibers Accelerates Cell Ingress Into Multifiber Composites." In ASME 2011 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2011. http://dx.doi.org/10.1115/sbc2011-53955.
Full textAbstract:
Fibrocartilaginous tissues such as the meniscus and annulus fibrosus serve critical load-bearing roles, relying on arrays of highly organized collagen fibers to resist tensile loads [1]. As these specialized structures are often injured, there exists great demand for engineered tissues for repair or replacement. Cell-laden aligned nanofibrous scaffolds formed from poly(ε-caprolactone) (PCL) have shown promise in achieving tissuelike mechanical and biochemical properties and can direct cellular and matrix organization in vitro [2]. A current limitation of nanofibrous scaffolds, however, is a slow rate of cellular infiltration, particularly in thick scaffolds. To address this, dynamic composite nanofibrous scaffolds have been fabricated via multi-fiber spinning [3], which can offer tunable modes of degradation depending on the polymer sources. For example, water-soluble polyethylene oxide (PEO) fibers can be co-spun with PCL to improve porosity and hasten cell ingress [4]. Incorporation of additional tunable and bioactive polymer sources may add greater versatility to these composite systems. For example, aqueous-based silk fibroin can be used as a slow-degrading, mechanically strong composite fiber component [5] into which active biologic factors (drugs, growth factors) can be incorporated [6]. Variably-degradable silk fibers can be formed by modulating post-spinning treatments, and protein release kinetics can likewise be manipulated by the physical crosslinking method [7]. We hypothesized that incorporation of robust and tunable silk protein-based fibers into a composite of slow-degrading synthetic fibers would provide mechanical function while delivering active biologic factors to expedite cell proliferation and encourage more rapid construct colonization. To test this hypothesis, we characterized the release kinetics of recombinant FGF-2 from silk fibers and its bioactivity in vitro and in a rat subcutaneous implant model.
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Kimmer, C. J., and C. K. Harnett. "Combining Strings and Fibers With Additive Manufacturing Designs." In ASME 2016 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/detc2016-59569.
Full textAbstract:
High tensile strength cables, low-resistance motor windings, and shape memory actuators are common examples of technical fibers used in robots and other electromechanical assemblies. Because properties like tensile strength, crystal structure, and polymer alignment depend strongly on processing history, these materials cannot be 3D printed with the same properties they have on the spool. Strings and fibers are inserted in mechanical parts at the end of the manufacturing process for these assemblies. When the fibers take complex paths, the installation is often done by hand. This activity can dominate the process time, increase its human labor and reduce its social sustainability [1]. This paper applies the non-traditional approach of machine embroidery to insert sheets of patterned fibers in layered additive manufacturing processes such as 3D printing and lamination. Fibers are aligned with features in laser-cut or printed parts without the manual labor of hand threading. We demonstrate that water-soluble stabilizer materials originally designed for textiles can hold hard mechanical parts in a machine embroidery hoop with enough strength and rigidity to withstand sewing through pre-existing holes in the part. Alignment to within 250 microns has been demonstrated with a sub-$300 consumer embroidery machine. Case studies in this paper include a cable-driven mechanism, a soft-to-hard electronic connection, and an electromechanical sensor. Process-compatible and commercially available materials that can be embroidered include conductive threads, shrinking threads, water-soluble threads and high tensile strength fibers. The biggest hurdle for a user interested in this automated fiber installation process is linking the existing design file with an embroidery machine file. There is a much larger user base for 2D and 3D computer-assisted design (CAD) software than for expensive and proprietary embroidery digitizing software. We take the route chosen by the laser cutter industry, where the user produces a CAD file in their preferred editor, and makes annotations that communicate where and how densely to stitch. Translation software scans the file for a particular line style and generates stitch coordinates along it. Development is done in Jupyter/iPython notebooks that allow end-users to inspect, understand, and modify the conversion code. The intent is for users of existing planar fabrication technology (whether laser, printed circuit board, or micro/nano) to apply this method to their own CAD files for a versatile and straightforward way to put advanced materials in their devices without adding manual labor. This general approach can solve a class of assembly problems relevant to underactuated tendon-driven robotics and other electromechanical systems, expanding the range of devices that can be put together using automation.
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Zhang, Le, and Andras Z. Szeri. "Anisotropic Diffusion of Large Neutral Solute in Cartilage." In ASME/STLE 2007 International Joint Tribology Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/ijtc2007-44220.
Full textAbstract:
Articular cartilage is an avascular soft tissue that covers the ends of the bones in diarthrodial joints. Since there are no blood vessels, chondrocytes rely on solute diffusion to receive nutrients and remove waste products. Diffusive transport is thus essential to the operation and maintenance of cartilage tissue. Cartilage is composed mainly of interstitial water and extracellular matrix, which consists of collagen fibers and proteoglycan. The distribution of collagen fibers and proteoglycan impart an inhomogeneous and anisotropic microstructure to the cartilage.