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Artykuły w czasopismach na temat "Functional Gels"
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NAKANISHI, Eiji. "Functional Polypeptide Gels." Kobunshi 48, nr 6 (1999): 408–11. http://dx.doi.org/10.1295/kobunshi.48.408.
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Wood, Tiffany A. "Functional molecular gels". Liquid Crystals Today 23, nr 4 (9.09.2014): 77–81. http://dx.doi.org/10.1080/1358314x.2014.945241.
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ITO, Yoshihiro, i Ryo YOSHIDA. "Micro-fabrication of Functional Gels". Kobunshi 53, nr 5 (2004): 340. http://dx.doi.org/10.1295/kobunshi.53.340.
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NITTA, TAKAYUKI, i YOSHIHITO OSADA. "Chemomechanical Reactions of Functional Polymer Gels". Sen'i Gakkaishi 49, nr 3 (1993): P104—P107. http://dx.doi.org/10.2115/fiber.49.3_p104.
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PARK, JAE W. "Functional Protein Additives in Surimi Gels". Journal of Food Science 59, nr 3 (maj 1994): 525–27. http://dx.doi.org/10.1111/j.1365-2621.1994.tb05554.x.
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Douzou, P. "Biological macromolecules as gels: functional similarities." Proceedings of the National Academy of Sciences 84, nr 19 (1.10.1987): 6741–44. http://dx.doi.org/10.1073/pnas.84.19.6741.
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Venkateswara Rao, P., S. Maniprakash, S. M. Srinivasan i A. R. Srinivasa. "Functional behavior of isotropic magnetorheological gels". Smart Materials and Structures 19, nr 8 (15.07.2010): 085019. http://dx.doi.org/10.1088/0964-1726/19/8/085019.
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YAMADA, Katsuya, Naoya YAMADA, Kouhei YAMADA, Masato WADA, Jin GONG, Masato MAKINO, Md Hasnat KABIR i Hidemitsu FURUKAWA. "808 Tribological Properties of Functional Gels". Proceedings of the Materials and processing conference 2013.21 (2013): _808–1_—_808–4_. http://dx.doi.org/10.1299/jsmemp.2013.21._808-1_.
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Havea, Palatasa, Alistair J. Carr i Lawrence K. Creamer. "The roles of disulphide and non-covalent bonding in the functional properties of heat-induced whey protein gels". Journal of Dairy Research 71, nr 3 (23.07.2004): 330–39. http://dx.doi.org/10.1017/s002202990400024x.
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Heat-induced gelation (80 °C, 30 min or 85 °C, 60 min) of whey protein concentrate (WPC) solutions was studied using transmission electron microscopy (TEM), dynamic rheology and polyacrylamide gel electrophoresis (PAGE). The WPC solutions (150 g/kg, pH 6·9) were prepared by dispersing WPC powder in water (control), 10 g/kg sodium dodecyl sulphate (SDS) solution or 10 mM-dithiothreitol (DTT) solution. The WPC gels containing SDS were more translucent than the control gels, which were slightly more translucent than the gels containing DTT. TEM analyses showed that the SDS-gels had finer aggregate structure (≅10 nm) than the control gels (≅100 nm), whereas the DTT-gels had a more particulate structure (≅200 to 300 nm). Dynamic rheology measurements showed that the control WPC gels had storage modulus (G′) values (≅13500 Pa) that were ≅25 times higher than those of the SDS-gels (≅550 Pa) and less than half those of the DTT-gels after cooling. Compression tests showed that the DTT-gels were more rigid and more brittle than the control gels, whereas the SDS-gels were softer and more rubbery than either the control gels or the DTT-gels. PAGE analyses of WPC gel samples revealed that the control WPC solutions heated at 85 °C for 10 min contained both disulphide bonds and non-covalent linkages. In both the SDS-solutions and the DTT-solutions, the denatured whey protein molecules were in the form of monomers or small aggregates. It is likely that, on more extended heating, more disulphide linkages were formed in the SDS-gels whereas more hydrophobic aggregates were formed in the DTT-gels. These results demonstrate that the properties of heat-induced WPC gels are strongly influenced by non-covalent bonding. Intermolecular disulphide bonds appeared to give the rubbery nature of heat-induced WPC gels whereas non-covalent bonds their rigidity and brittle texture.
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Zivkovic, D., V. Peric i Marija Perunovic. "Examination of some functional properties of silver carp (hypophthalmichthys molitrix val) and carp (cyprinus carpio lin) meat". Journal of Agricultural Sciences, Belgrade 49, nr 2 (2004): 193–203. http://dx.doi.org/10.2298/jas0402193z.
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Water binding ability (WBA), held water (HW) and gel-forming properties of silver carp (Hypophthalmichthys molitrix Val) and carp (Cyprinus carpio Lin) meat were examined in this paper. Two variants of fish meat gels: A with 50% of meat and B with 60% of meat were examined at temperatures: 70 75, 80, 85 and 90 oC. The variant A of silver carp meat gels has shown the maximum of WBA and HW at 80 oC, and the variant B at 75 oC. In both variants of carp meat gels slow increase of WBA and HW with rise of temperature to 80oC was established. Silver carp meat gels have had better WBA than control gels (beef and poultry meat), and carp meat gels have better HW, but somewhat worse WBA than control gels. In gels of variant A of silver carp meat the highest module of elasticity (6.862 N/cm2) was found at thermal treatment at 85 oC, but statistically significant differences in relation to other temperatures were not established. In variant B, with the rise of temperature, the module of elasticity increases; statistically significant differences were established among gels treated at 70 oC and others. Differences between variants A and B were statistically significant at all examined temperatures. Meat gels of silver carp have significantly lower module of elasticity compared to control gels. Under conditions of our experiment the module of elasticity of carp meat was below measuring limit.
Rozprawy doktorskie na temat "Functional Gels"
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Singh, Nishant. "Functional gels as microreactors". Doctoral thesis, Universitat Jaume I, 2016. http://hdl.handle.net/10803/397698.
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Functionalized Hydrogels upon self-assembly demonslrate enzyme like catalysis owing to the formatin of
hydrophobic pockets, increased local concentration of the catalytic sites, pKa change, pH shift etc. Here
we present such hydrogelators being able to demonstrate enhanced catalysis for a range of reactions
such as aldol, mannich, ester hydrolysis, deacetalisation etc.Hidrogelantes funcionalizados sobre autoensamblaje pueden demostrar como la catálisis enzimática mejorada basada en varios factores tales como bolsillos hidrofóbicos, cambio en pH, cambio en pKa, aumento en la concentración local de los sitios activos etc. Aquí presentamos tales tipos de hidrogelantes que son capaces de demostrar varios tipos de reacciones importantes como aldolica, Mannicli, hidrolisis, deactetalisation, etc.
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Rossow, Torsten [Verfasser]. "Functional Polymer Gels by Click- and Supramolecular Chemistry / Torsten Rossow". Berlin : Freie Universität Berlin, 2014. http://d-nb.info/1059391872/34.
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Hackelbusch, Sebastian [Verfasser]. "Functional Polymeric Toolkits: From Supramolecular to Hybrid Polymer Gels / Sebastian Hackelbusch". Berlin : Freie Universität Berlin, 2016. http://d-nb.info/1098185420/34.
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Patel, Chirag Bharatkumar. "Functional polymers and gels for the purification of phosphorylated and thiophosphorylated proteins". Thesis, Imperial College London, 2013. http://hdl.handle.net/10044/1/39372.
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Reversible protein phosphorylation is a universal means of regulating many processes in cell such as division, development and differentiation. Aberrant phosphorylation often causes or exacerbates disease progression (e.g. cancer). While significant progress has been made in the identification and biochemical characterisation of the protein kinases and phosphatases themselves, it has proven significantly more problematic to identify their substrates. Thus, the development o f techniques for the separation and enrichment of phosphoproteins or phosphopeptides is vital to assist substrate identification. Advances have been made however; the techniques remain limited for a number of reasons: 1-3 - Phosphorylation levels are low. - Any given protein may have a number of different phosphorylated forms. - The abundance of signalling molecules in the cell in very little. - Current analytical techniques do not have sufficient sensitivity and thus sometimes miss the identification of minor phosphorylation sites. The results presented in this thesis explore the three techniques of: (1) affinity gel electrophoresis, (2) affinity bead chromatography and (3) molecularly imprinted polymers for the improvement of phosphorylation analysis by utilising polymeric materials that incorporate synthetic receptors known to selectively bind phosphorylated species. The approaches taken towards each technique's synthesis and recognition of the selected biologically active compounds have been discussed. Furthermore several studies were carried out to elucidate all three techniques' performances under a variety of condition and also reveal their limitations. Affinity gel electrophoresis and affinity bead chromatography results have shown separation and enrichment in model mixtures and more importantly, in highly complex cell lysate samples. Moreover both techniques - selectivity for phosphorylated proteins can be tuned to thiophosphorylated proteins by simply changing the metal in receptor from manganese or zinc to cadmium. Furthermore PAGE imprinted gels and molecularly imprinted polymer monoliths in aq. buffered solutions were synthesised and tested. PAGE imprinted gels using phosphoprotein and phosphoepitopes as templates proved unsuccessful with no improvement in the separation of phosphoproteins. However, molecularly imprinted polymer monoliths prepared using a phosphoepitope as a template have displayed strong imprinting effects for the first time. However, selectivity at the level of phosphoepitopes remains an on-going challenge.
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Stancil, Kimani Atiim 1972. "Molecular recognition : conformational memory and the macroscopic functional character of heteropolymer gels". Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/8485.
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Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Physics, 2002.Includes bibliographical references (leaves 158-161).
Molecular Recognition is an implicit and necessary step for proteins to realize their function. The late Professor Toyoichi Tanaka of M.I.T. proposed that polymer gels be used as protein 'mimics'. Multi-contact adsorption is engineered as a measure of gel function. Adsorbers within the gel's polymer network cluster to form an active site for molecular capture. A gel's conformation impacts both protein folding, and the testing of the polymer freezing transition. Multi-contact adsorption has been observed in gels, and is affected by the gel's volume phase transition. In our study, gels were synthesized to contain carboxyl groups that are incorporated either randomly, or by chemical imprinting using the template, Pb(MAAc)2 . After removing the guest molecule, we test adsorption of divalent molecules, lead (Pb+2), the original guest molecule, or calcium (Ca+2). We evaluate the gel's ability to recognize target molecules by analyzing the affinity and saturation values obtained using the Langmuir adsorption isotherm. Two methods are used to obtain adsorption data: 1) complexation of 4-(2-Pyridylazo)-resorcinol with lead (Pb+2) for spectrometric determination of lead equilibrium concentrations, and 2) an ion sensitive electrode was used for calcium concentrations. We show that method 1) involves less error than method 2). Imprinting improves multi-contact adsorption by gels. Collapsing the gel via the phase transition positively affects adsorption of both Pb+ and Ca+2. Our gels adsorb lead better than calcium, indicating a favoring of the original guest molecule. However, the gel cannot recover all active sites that were intended during synthesis. We discover, more in imprinted gels, that positive changes in affinity result as a function of increased cross-linking density.
(cont.) We discuss the preparation and topological aspects that impact conformation and the potential impact on testing conformational memory and creating successful protein mimics.
by Kimani Atiim Stancil.
Ph.D.
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Green, Travis Cole. "Functional Materials and Chemistry Education: Biomimetic Metallopolymers, Photoresponsive Gels and Infrared Cameras". Bowling Green State University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1586520472810668.
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Pettignano, Asja. "Alginate : a versatile biopolymer for functional advanced materials". Thesis, Montpellier, Ecole nationale supérieure de chimie, 2016. http://www.theses.fr/2016ENCM0004.
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Les alginates, des polysaccharides produits par les algues brunes, sont des copolymères à blocs linéaires, formés d’unités mannuronate (M) et guluronate (G). En raison de leur abondance naturelle, prix et propriétés physicochimiques avantageuses, les alginates représentent une classe de biopolymères très intéressante et relativement inexplorée pour des applications dans le domaine des matériaux avancés. Dans ce contexte, le présent travail vise à enrichir la gamme des applications des matériaux dérivés d’alginates, en exploitant les propriétés de cette classe de polysaccharides naturels. En particulier, la préparation de matériaux à base d'alginate pour la catalyse, l'adsorption et le domaine biomédical a été étudiée, avec des résultats encourageants dans toutes les applications testées. L'utilisation bénéfique de l'acide alginique en catalyse hétérogène a été démontrée, en tant que promoteur de réaction et support pour l’hétérogénéisation d'un organocatalyseur. L'activité du catalyseur a été trouvée très dépendante de l'accessibilité des groupes fonctionnels, mettant en évidence l’avantage de l’emploi de formulations plus accessibles. La texturation des alginates a été aussi avantageuse dans la préparation de matériaux pour applications en flux. Des mousses d'acide alginique, avec une structure hiérarchique macro-mésoporeuse, ont été développées à cet effet. Une caractérisation précise des matériaux a été réalisée, afin d'optimiser la procédure de préparation et de corréler les propriétés texturales obtenues avec les paramètres utilisés. L'intérêt dans l’utilisation de mousses à base d'acide alginique a été démontré dans une application modèle, l'adsorption de bleu de méthylène à partir de solutions aqueuses, à la fois en batch et en flux. La possibilité de modifier facilement les groupes fonctionnels de l’alginate, couplée avec la nature biocompatible et biodégradable de ces biopolymères, a finalement été exploitée pour le développement de gels auto-réparants, obtenus grâce à la formation de deux types d'interactions covalentes dynamiques : base de Schiff et ester de boronate. Les deux systèmes examinés ont présenté une remarquable habilité à se reconstruire après un dégât, même si l'ampleur de la reconstruction et la stabilité des gels étaient fortement dépendantes des paramètres de préparation des gels et des conditions environnementales utilisées. Les résultats obtenus dans le cadre de cette étude démontrent clairement comment la compréhension et un emploi conscient des propriétés physico-chimiques des alginates peuvent maximiser le potentiel que cette ressource durable dans le domaine de la chimie des matériauxAlginates, polysaccharides produced by brown algae, are linear block-copolymers formed by mannuronate (M) and guluronate (G) units. Because of their huge natural abundance, cheapness and physicochemical properties, alginates represent a highly attractive and still relatively unexplored class of biopolymers for applications in the field of advanced materials. In this context, the present work aimed to enrich the range of possible applications of alginate-derived materials, making the most of the peculiar features of this class of natural polysaccharides. In particular, the preparation of alginate-based active materials to be employed in the catalysis, adsorption and biomedical field was studied, achieving encouraging results in all the tested applications. The beneficial use of alginic acid in heterogeneous catalysis, both as reaction promoter and as support for the heterogeneization of an organocatalyst, was demonstrated. The activity of the material was found highly dependent on the accessibility of the active functions, highlighting the advantage of employing more accessible alginate formulations. The texturation of alginates was further advantageous for the preparation of materials with improved flowability. Alginic acid foams, bearing a hierarchical macro-mesoporous structure were developed by means of a simple procedure. Accurate characterization was performed to optimize the preparation procedure and to correlate the textural properties of the obtained materials with the parameters used. The interest of the prepared alginic acid foams was demonstrated in a model application, the adsorption of methylene blue from aqueous solutions, both in batch and in flow conditions. The possibility to easily modify alginate functional groups, coupled with the biocompatible and biodegradable nature of alginates, was finally employed for the development of self-healing gels, thanks to the formation of two types of dynamic covalent interactions: Schiff base and boronate ester bonds. Both the examined systems presented a marked ability to recover after damage, even if the extent of the recovery and the stability of the gels was highly dependent on the preparation parameters and environmental conditions used. The results obtained in the course of this study clearly demonstrate how a full comprehension and conscious employment of alginate physicochemical properties can maximize the potential of this sustainable resource in the field of material chemistry
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Häring, Marleen [Verfasser], i Díaz David [Akademischer Betreuer] Díaz. "Synthesis, Characterization and Application of New Functional Gels / Marleen Häring ; Betreuer: David Díaz Díaz". Regensburg : Universitätsbibliothek Regensburg, 2018. http://d-nb.info/117117182X/34.
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Baos, Sarah. "Functional Mapping of Ocular Mucins : Investigating Single Molecules & Mucous Gels using Atomic Force Microscopy". Thesis, University of Bristol, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.525452.
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Topuz, Fuat [Verfasser], Martin [Akademischer Betreuer] Möller i Jürgen [Akademischer Betreuer] Groll. "Functional star-type polyethylene glycol copolymers for hydrogels and biohybrid gels / Fuat Topuz ; Martin Möller, Jürgen Groll". Aachen : Universitätsbibliothek der RWTH Aachen, 2015. http://d-nb.info/1127232029/34.
Pełny tekst źródłaKsiążki na temat "Functional Gels"
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Escuder, Beatriu, i Juan F. Miravet, red. Functional Molecular Gels. Cambridge: Royal Society of Chemistry, 2013. http://dx.doi.org/10.1039/9781849737371.
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Polymer Networks Group Meeting (16th 2002 Autrans, France). Functional networks and gels: Papers presented at the 16th Polymer Networks Group Meeting : polymer networks 2002 : held in Autrans, France, 2-6 September 2002. Redaktorzy Geissler Erik i International Union of Pure and Applied Chemistry. Macromolecular Division. Weinheim, Germany: Wiley-VCH, 2003.
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1927-, Jollès Pierre, i Jörnvall Hans, red. Proteomics in functional genomics: Protein structure analysis. Basel: Birkhäuser Verlag, 2000.
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Pollack, Gerald H. Cells, gels and the engines of life: A new, unifying approach to cell function. Seattle, WA: Ebner & Sons, 2001.
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Kunz, George Frederick. The curious lore of precious stones: An illustrated guide to the history and powers of gemstones, with information on birthstones, gemstone properties and therapy, crystals and crystal gazing, and the protective and preventative functions of amulets and talismans. New York: Bell, 1989.
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R, Pennington S., i Dunn M. J, red. Proteomics: From protein sequence to function. Oxford: BIOS, 2001.
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Heering, Walter. Geld, Liquiditätsprämie und Kapitalgüternachfrage: Studien zur entscheidungstheoretischen Fundierung einer monetären Theorie der Produktion. Regensburg: Transfer, 1991.
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Postoutenko, Kirill, red. Totalitarian Communication. Bielefeld, Germany: transcript Verlag, 2010. http://dx.doi.org/10.14361/9783839413937.
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Totalitarianism has been an object of extensive communicative research since its heyday: already in the late 1930s, such major cultural figures as George Orwell or Hannah Arendt were busy describing the visual and verbal languages of Stalinism and Nazism. After the war, many fashionable trends in social sciences and humanities (ranging from Begriffsgeschichte and Ego-Documentology to Critical Linguistics and Critical Discourse Analysis) were called upon to continue this media-centered trend in the face of increasing political determination of the burgeoing field. Nevertheless, the integration of historical, sociological and linguistic knowledge about totalitarian society on a firm factual ground remains the thing of the future. This book is the first step in this direction. By using history and theory of communication as an integrative methodological device, it reaches out to those properties of totalitarian society which appear to be beyond the grasp of specific disciplines. Furthermore, this functional approach allows to extend the analysis of communicative practices commonly associated with fascist Italy, Nazi Germany and Soviet Union, to other locations (France, United States of America and Great Britain in the 1930s) or historical contexts (post-Soviet developments in Russia or Kyrgyzstan). This, in turn, leads to the revaluation of the very term »totalitarian«: no longer an ideological label or a stock attribute of historical narration, it gets a life of its own, defining a specific constellation of hierarchies, codes and networks within a given society.
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Functional Molecular Gels. Royal Society of Chemistry, 2013.
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Functional Polymer Solutions and Gels–Physics and Novel Applications. MDPI, 2020. http://dx.doi.org/10.3390/books978-3-03936-231-8.
Pełny tekst źródłaCzęści książek na temat "Functional Gels"
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Pivin, Jean-Claude. "Synthesis Procedures of Nanocomposites from Gels". W Functional Properties of Nanostructured Materials, 161–68. Dordrecht: Springer Netherlands, 2006. http://dx.doi.org/10.1007/1-4020-4594-8_9.
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Nguyen, Chi, Prashant Deshmukh, Xiaorui Chen, Sergio Granados-Focil i Rajeswari Kasi. "Thermoreversible Ion Gels From Side-Chain Liquid Crystalline Brushes Diblock Copolymers". W Functional Polymers, 241–63. Taylor & Francis Group, 6000 Broken Sound Parkway NW, Suite 300, Boca Raton, FL 33487-2742: CRC Press, 2017. http://dx.doi.org/10.1201/9781315366524-9.
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Dottin, Robert P., Bodduluri Haribabu, Clifford W. Schweinfest i Richard E. Manrow. "Activity Gels: Reformation of Functional Proteins in SDS-Polyacrylamide Gels". W Genetic Engineering, 121–33. Boston, MA: Springer US, 1987. http://dx.doi.org/10.1007/978-1-4684-5377-5_8.
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Konno, Mikio, Tomoya Tsuji i Shozaburo Saito. "Permeation Mechanism for a Thermo-Sensitive Switching-Functional Composite Membrane of Porous Glass and Hydrogel". W Polymer Gels, 173–81. Boston, MA: Springer US, 1991. http://dx.doi.org/10.1007/978-1-4684-5892-3_12.
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Bekiari, Vlasoula, Elias Stathatos, Panagiotis Lianos, Urska L. Stangar, Boris Orel i Patrick Judeinstein. "Studies on Hybrid Organic/Inorganic Nanocomposite Gels Using Photoluminescence Techniques". W Molecular Materials and Functional Polymers, 97–102. Vienna: Springer Vienna, 2001. http://dx.doi.org/10.1007/978-3-7091-6276-7_9.
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Wang, Bo, i Ji-Heung Kim. "Various Functional and Stimuli-Responsive Hydrogel Based on Polyaspartamides". W Gels Horizons: From Science to Smart Materials, 409–34. Singapore: Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-10-6077-9_15.
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Livage, Jacques, Thibaud Coradin i Cécile Roux. "Bioactive Sol-Gel Hybrids". W Functional Hybrid Materials, 387–404. Weinheim, FRG: Wiley-VCH Verlag GmbH & Co. KGaA, 2005. http://dx.doi.org/10.1002/3527602372.ch11.
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Sadanobu, Jiro, i Rei Nishio. "Gel-drawn Poly(p-phenylenepyromellitimide)". W Functional Condensation Polymers, 299–309. Boston, MA: Springer US, 2002. http://dx.doi.org/10.1007/0-306-47563-4_21.
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Urayama, Kenji, Naoki Murata, Shoji Nosaka, Masahiro Kojima i Toshikazu Takigawa. "Revisit to swelling kinetics of gels". W Gels: Structures, Properties, and Functions, 107–12. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-642-00865-8_15.
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Hossain, Khandker S., i Katsuyoshi Nishinari. "Chain Release Behavior of Gellan Gels". W Gels: Structures, Properties, and Functions, 177–86. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-642-00865-8_25.
Pełny tekst źródłaStreszczenia konferencji na temat "Functional Gels"
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Cao, Yiping, i Mahesh Khot. "Food protein self-assembly towards high-performance functional materials". W 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/oyxx3948.
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Proteins not only determine the essential life activities of living organisms and the nutritional value of food products, but also are promising raw materials for designing functional materials, including in the fields of food science, environmental science, and nanomaterials. In the last decade, self-assembly of food proteins, particularly fibrillization, has attracted significant interest, as the assembled nanostructures are characterized by abundant b-sheet structures, large aspect ratio, and diverse surface functional groups. These features offer the possibility to overcome existing technological bottlenecks, and the rational utilization can yield high-performance materials. This talk will focus on two examples: protein gels and plastics. In the first example, a quantitative relationship was established between the microstructure of protein nanofibrils and the macroscopic mechanical properties of the resulting gels. This was successfully used to build protein gels with mechanical properties comparable to those of artificial meat. In the second example, protein-based plastics with high mechanical property and reduced hygroscopicity are developed by combining protein copolymerization and self-assembly. This provides a potential strategy for developing sustainable food packaging materials.
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Lai, Victor K., Edward A. Sander, Robert T. Tranquillo i Victor H. Barocas. "Mechanical Properties of Collagen-Fibrin Co-Gels". W ASME 2009 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2009. http://dx.doi.org/10.1115/sbc2009-206700.
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Achieving desired mechanical properties is critical to meeting the functional requirements of engineered tissues. Mechanical function is inextricably linked to tissue structure. For example, replacement of fibrin with collagen during the healing process results in compositional heterogeneity which governs mechanical strength and function. Artificial tissues engineered using biopolymers such as fibrin and collagen can undergo a remodeling process that produces a compositionally and structurally complex tissue equivalent (TE) with anisotropic mechanical properties. TE functionality is assessed in part through mechanical testing, but the TE response is dependent on multi-scale interactions, which are dependent on a heterogeneously distributed microstructure, and are therefore difficult to interpret. In order to unravel the coupling between TE microstructure and macroscopic mechanical behavior, we have developed a multi-scale modeling framework for incorporating single component microstructural networks [1]. To expand our modeling framework, it is necessary to incorporate interpenetrating fibrin and collagen networks. This issue is particularly critical towards understanding the remodeling process that occurs in fibrin gels, which gradually replace fibrin with collagen networks. In this work, we have begun to investigate interpenetrating fibrin-collagen co-gels by varying the co-gel composition and subjecting the gels to uniaxial mechanical tests [2]. This study lays the experimental foundation for determining how to construct interpenetrating networks for our multiscale modeling framework, which will ultimately allows us to better assess and predict TE mechanics and produce better engineered tissues.
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Freytes, Donald O., Samuel Kolman, Sachin S. Velankar i Stephen F. Badylak. "Rheological Properties of Extracellular Matrix Derived Gels". W ASME 2007 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2007. http://dx.doi.org/10.1115/sbc2007-176537.
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Bioscaffolds composed of extracellular matrix (ECM) have been used for the repair of a variety of tissues often leading to tissue-specific constructive remodeling [1]. ECM scaffolds are typically prepared by decellularization of tissues and are composed of the structural proteins (e.g. collagen) and functional proteins (e.g. growth factors) that characterize the native ECM. However, for certain applications, the use of ECM scaffolds can be limited by the native two-dimensional sheet form in which they are harvested.
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Rahman, Md Mahfuzur, i Buddhi Lamsal. "Effects of high power sonication and atmospheric cold plasma on the dispersions and gelling properties of mung bean protein". W 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/qsnz5579.
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Mung bean protein (MBP) is a comparatively lesser-known plant (legume) protein that has attracted the interest of food industry mostly for its nutritional and functional properties. The objective of this study was to improve the gelling properties of mung bean protein isolate (MBPI) with high-power sonication (HPS) and atmospheric cold plasma (ACP) treatments. HPS at 250 J/mL for 2 mins and ACP at 80 kV for 5 mins were applied to different concentrations of MBPI prepared in lab. Control MBPI dispersions showed minimum gelling concentration (MGC) at 16% w/v, while ACP-treated showed at 14%. HPS did not reduce the MGC. Dynamic rheology of dispersions showed that HPS and ACP treatments could reduce the gelling temperature (Tg) to 52° and 65 °C, respectively, from 75°C for control. ACP-treated 16% protein dispersions showed six-fold higher storage modulus (G') than the control; however, G' values among 16% control, 14% ACP treated, and 16% HPS-treated protein dispersions were similar. Gels from ACP-treated 16% protein dispersion were the firmest, with hardness value that is 39% greater than those of gels from HPS treated 16% protein. HPS-treated protein gels showed better springiness, cohesiveness, gumminess, chewiness, and resilience than ACP-treated protein gel. ACP-treated protein had significantly higher hydrophobic and disulfide bonds, which promote the formation of harder gels. However, for HPS-treated proteins, the net interaction of ionic, hydrogen, hydrophobic, and disulfide bonds resulted in a more transparent gel with better textural profile (other than hard hardness) compared with ACP-treated protein samples.
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Chen, Lingyun. "Structural design of plant protein gel networks for food applications". W 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/wnsz2802.
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Gelation is one of the most important functional properties of proteins as it provides texture and structure in foods. Gelatin, egg white and whey proteins are widely used as gelling agents in the food industry. Plant proteins are considered inferior to animal proteins in gelling properties. With the recent surge in demand led by sustainability and health considerations, plant-based food products have taken a center stage in food product innovation. This trend has spurred academic and industrial interest to explore the opportunity of developing gelling ingredients from diversified plant protein sources, replacing animal protein based gels. This presentation will introduce the recent research efforts in our group to develop gelling properties from emerging sources of plant proteins (e.g. pea, lentil and oat). The structural design approaches (e.g. pH-shifting, protein aggregates to build gel network) and novel technologies (e.g. cold plasma, high pressure) that have potential to increase gel performances from plant proteins will be highlighted. The gel rheological properties and mechanical strength as impacted by the protein composition, conformation and aggregation will be discussed. The food application of plant protein based gels will be illustrated.
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Jeganathan, Brasathe, Feral Temelli i Thavaratnam Vasanthan. "Functional properties of faba bean proteins extracted by different aqueous processes for food applications". W 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/phkb7574.
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Dry fractionation of faba bean protein is a sustainable alternative to energy-intensive wet fractionation approaches. However, it can only lead to relatively modest enrichment in protein content. The primary goal of this study was to compare the impact of aqueous protein extraction processes on the functionalities of faba bean proteins for food applications. Proteins from two Canadian faba bean cultivars Snowbird (zero-tannin, ZT) and Athena (high-tannin, HT) were extracted by dialysis following water extraction (W) and salt extraction (S) processes, and conventional alkali-acid approach (A). Although salt-soluble globulins were the primary proteins found in faba beans based on Osborne's protein classification, protein isolates (PIs) from ZT-W and HT-W had significantly higher (P< 0.05) protein contents on a dry matter basis (89.8±0.4% and 92.0±0.0%, respectively, Nx6.25) as compared to protein concentrates (PCs) from ZT-S (78.2±0.4%) and HT-S (77.7±0.2%). These differences in protein extractability could be attributed to the higher levels of naturally present minerals. Substantially lower (P< 0.05) mineral contents were detected in HT in comparison to ZT, plausibly due to the affinity of tannins towards minerals. Calorimetric analysis of W-PIs and A-PIs maintained at low-moisture contents resulted in a very high denaturation temperature range (225-235°C), implying their thermal stability for high-temperature processing. Furthermore, solubility, foaming and emulsification properties, and hydration capacities of W-PIs were higher or comparable to those of A-PIs and S-PCs. Dynamic rheological studies (25€“95€“25 °C) of W-PI heat-induced gels indicated that storage modulus (G') and loss modulus (G'') increased over time with an early crossover point (G' > G'') as compared to A-PIs. The stress and strain at fracture of W-PIs and A-PIs gels were comparable to those of whole egg gels. In summary, W-PIs were superior to S-PCs in terms of their functionalities and can be considered chemical-free alternatives to A-PIs, for sustainable food applications.
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Zhou, Hualu, Giang Vu i David J. McClements. "Rubisco Proteins as Plant-based Alternatives to Egg White Proteins: Characterization of Thermal Gelation Properties". W 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/vamx3998.
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RuBisCO proteins can be isolated from abundant and sustainable plant sources, such as duckweed (e.g., Lemnoideae). These plant-based globular proteins are capable of irreversibly unfolding and forming gels when heated, which means they may be able to mimic some of the functional attributes exhibited by animal globular proteins. In this study, we examined the ability of RuBisCo proteins to mimic the initial rheology and thermal gelation properties of egg white, which the aim of developing plant-based egg analogs. The impact of protein concentration (10-15% w/w), pH (7 to 9), and calcium concentration (0 to 50 mM CaCl2) on the properties of the egg white analogs was examined. The appearance (colorimetry), thermal denaturation (differential scanning calorimetry), thermal gelation (dynamic shear rheology), and texture profiles (compression testing) were measured. RuBisCO-based egg white analogs could be successfully produced at 10% protein content and pH 8 in the absence of salt. These RuBisCO protein solutions had similar apparent viscosity-shear rate profiles, shear modulus-temperature profiles, gelling temperatures, and final gel strengths as egg white. However, there were some differences. RuBisCO protein gels were slightly darker than egg white, which was attributed to the presence of some phenolic impurities. RuBisCo protein exhibited a single thermal transition temperature (~ 66 ℃) whereas egg white exhibited two (~66 and ~81 ℃). RuBisCo protein gels were more brittle but less chewy and resilient than egg white gels. This study provides valuable insights into the potential of RuBisCo protein for formulating plant-based egg white analogs, which may help improve the sustainability of the modern food supply.
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Lai, Victor K., Spencer P. Lake, Bumjun Kim, Emily M. Weiss, Robert T. Tranquillo i Victor H. Barocas. "Swelling of Collagen-Hyaluronic Acid Tissue-Equivalents: An Experimental Model to Evaluate Residual Stress in Soft Tissues". W ASME 2013 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/sbc2013-14609.
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Collagen gel tissue-equivalents (TEs), which are simple model tissues with tunable properties, have been used to explore many properties of soft tissues, such as how structural and compositional properties affect mechanical function [1–4]. One aspect not captured in previous TE formulations is residual stress due to interactions among components, which has an important functional role in many tissues (e.g., blood vessels [5], ligaments [6], annulus fibrosus [7]). Since the in vivo stress state of native tissues is not easily replicated in TE fabrication, a different method for “pre-stressing” collagen networks of TEs was necessary. To this end, co-gel TEs were fabricated by adding hyaluronic acid (HA) to reconstituted Type-I collagen (Col) gels. When placed in solutions of varying osmolarity, HA-Col TEs swell as the HA binds water, which in turn will stretch (and stress) the collagen network. In this way, TEs with residual stress (i.e., pre-stressed collagen fibers) can be fabricated and evaluated in order to elucidate relationships between residual stress and functional properties. Therefore, the goals of the present study were to fabricate HA-Col TEs, make initial measurements of their swelling properties, and quantify the mechanical response and changes in microstructural organization under applied tensile load.
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Clezardin, P., i J. L. McGregor. "STRUCTURAL AND FUNCTIONAL COMPARISON OF THROMBOSPONDIN FROM PLATELETS, ENDOTHELIAL CELLS AND FIBROBLASTS". W XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643819.
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Thrombospondin (TBSP) is a 450 kDa glycoprotein secreted by a wide range of cells including platelets, endothelial cells and fibroblasts. Using non-denaturating conditions, we recently reported that platelet TBSP was structurally different from endothelial and fibroblast TBSP (P. Clezardin et al., Eur. J. Biochem., 1986, 159, 569-579). The aim of this study was to compare the structure of TBSP purified from platelets, endothelial cells and fibroblasts using denaturating conditions. Moreover, the interaction of fibrinogen with these three forms of TBSP was also investigated. TBSPs were first purified by heparin-Sepharose and immunoaffinity chromatography followed by Mono O anion-exchange chromatography on a FPLC system. Thermolysin digests of purified TBSPs were analysed by SDS-polyacrylamide gel electrophoresis under reducing conditions and the subsequent electrophoresed proteolytic fragments identified by Coomassie and silver staining. The interaction of undigested and digested TBSPs with solid-phase adsorbed fibrinogen was investigated by enzyme-linked immunosorbent assay using an anti-TBSP monoclonal antibody (P10). when using Coomassie staining, a 70 kDa proteolytic fragment of thermolysin-treated platelet TBSP was absent from the endothelial and fibroblast TBSP digests. Moreover, a 18 kDa fragment from thermolysin-treated endothelial and fibroblast TBSP was undetectable in the platelet TBSP digest when using silver staining on SDS-polyacrylamide gels. The binding of undigested TBSPs to solid-phase adsorbed fibrinogen was different from that obtained with digested TBSPs. These results indicate that the observed structural differences might induce functional differences between platelet and the two other forms of TBSP.
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Chahine, Nadeen O., Eric G. Lima, Clark T. Hung i Gerard A. Ateshian. "Effect of Dynamic Deformational Loading on the Transport of Dextran Molecules Into Agarose Gels". W ASME 2004 International Mechanical Engineering Congress and Exposition. ASMEDC, 2004. http://dx.doi.org/10.1115/imece2004-61368.
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The poor intrinsic healing capacity of articular cartilage has led to a number of attempts to engineer a replacement tissue [1]. One of these approaches, termed functional tissue engineering, suggests that the application of mechanical preconditioning, mimicking the in vivo loading environment, may enhance the development of material properties in these constructs [2,3]. Using this approach, our previous studies have demonstrated that dynamic loading (DL) increases the mechanical properties of chondrocyte-seeded agarose hydrogels relative to free swelling (FS) controls [4–6]. One mechanism by which the increase in mechanical properties occurs is hypothesized to be due to enhanced transport of nutrients and/or growth factors under dynamic loading [7]. The goal of the current study is to determine the effect of dynamic loading on the transport of neutral dextran molecules into agarose gels. Dextran, a neutral and generally inert solute commonly used in diffusion and transport studies, is used in its fluorophore-conjugated form thus making it possible to track the solute and quantify its content inside a hydrogel. We hypothesize that the uptake of dextran molecules into the agarose gels will be significantly enhanced under the influence of physiological dynamic deformation loading. Two varying molecular weights of dextran, 3 kDa and 70 kDa, were chosen in this study to ascertain a wide range of transport behaviors, and to interpret the experimental results in the context of a recently developed mixture theory model for the transport of neutral solutes in a neutrally charged gel, such as agarose [8].
Raporty organizacyjne na temat "Functional Gels"
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Pelaez, Jose R. Measuring the QCD Gell Mann-Low Psi-Function. Office of Scientific and Technical Information (OSTI), czerwiec 1999. http://dx.doi.org/10.2172/9986.
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Heifetz, Yael, i Michael Bender. Success and failure in insect fertilization and reproduction - the role of the female accessory glands. United States Department of Agriculture, grudzień 2006. http://dx.doi.org/10.32747/2006.7695586.bard.
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The research problem. Understanding of insect reproduction has been critical to the design of insect pest control strategies including disruptions of mate-finding, courtship and sperm transfer by male insects. It is well known that males transfer proteins to females during mating that profoundly affect female reproductive physiology, but little is known about the molecular basis of female mating response and no attempts have yet been made to interfere with female post-mating responses that directly bear on the efficacy of fertilization. The female reproductive tract provides a crucial environment for the events of fertilization yet thus far those events and the role of the female tract in influencing them are poorly understood. For this project, we have chosen to focus on the lower reproductive tract because it is the site of two processes critical to reproduction: sperm management (storage, maintenance, and release from storage) and fertilization. E,fforts during this project period centered on the elucidation of mating responses in the female lower reproductive tract The central goals of this project were: 1. To identify mating-responsive genes in the female lower reproductive tract using DNA microarray technology. 2. In parallel, to identify mating-responsive genes in these tissues using proteomic assays (2D gels and LC-MS/MS techniques). 3. To integrate proteomic and genomic analyses of reproductive tract gene expression to identify significant genes for functional analysis. Our main achievements were: 1. Identification of mating-responsive genes in the female lower reproductive tract. We identified 539 mating-responsive genes using genomic and proteomic approaches. This analysis revealed a shift from gene silencing to gene activation soon after mating and a peak in differential gene expression at 6 hours post-mating. In addition, comparison of the two datasets revealed an expression pattern consistent with the model that important reproductive proteins are pre-programmed for synthesis prior to mating. This work was published in Mack et al. (2006). Validation experiments using real-time PCR techniques suggest that microarray assays provide a conservativestimate of the true transcriptional activity in reproductive tissues. 2.lntegration of proteomics and genomics data sets. We compared the expression profiles from DNA microarray data with the proteins identified in our proteomic experiments. Although comparing the two data sets poses analyical challenges, it provides a more complete view of gene expression as well as insights into how specific genes may be regulated. This work was published in Mack et al. (2006). 3. Development of primary reproductive tract cell cultures. We developed primary cell cultures of dispersed reproductive tract cell types and determined conditions for organ culture of the entire reproductive tract. This work will allow us to rapidly screen mating-responsive genes for a variety of reproductive-tract specifi c functions. Scientific and agricultural significance. Together, these studies have defined the genetic response to mating in a part of the female reproductive tract that is critical for successful fertllization and have identified alarge set of mating-responsive genes. This work is the first to combine both genomic and proteomic approaches in determining female mating response in these tissues and has provided important insights into insect reproductive behavior.
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Christopher, David A., i Avihai Danon. Plant Adaptation to Light Stress: Genetic Regulatory Mechanisms. United States Department of Agriculture, maj 2004. http://dx.doi.org/10.32747/2004.7586534.bard.
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Original Objectives: 1. Purify and biochemically characterize RB60 orthologs in higher plant chloroplasts; 2. Clone the gene(s) encoding plant RB60 orthologs and determine their structure and expression; 3. Manipulate the expression of RB60; 4. Assay the effects of altered RB60 expression on thylakoid biogenesis and photosynthetic function in plants exposed to different light conditions. In addition, we also examined the gene structure and expression of RB60 orthologs in the non-vascular plant, Physcomitrella patens and cloned the poly(A)-binding protein orthologue (43 kDa RB47-like protein). This protein is believed to a partner that interacts with RB60 to bind to the psbA5' UTR. Thus, to obtain a comprehensive view of RB60 function requires analysis of its biochemical partners such as RB43. Background & Achievements: High levels of sunlight reduce photosynthesis in plants by damaging the photo system II reaction center (PSII) subunits, such as D1 (encoded by the chloroplast tpsbAgene). When the rate of D1 synthesis is less than the rate of photo damage, photo inhibition occurs and plant growth is decreased. Plants use light-activated translation and enhanced psbAmRNA stability to maintain D1 synthesis and replace the photo damaged 01. Despite the importance to photosynthetic capacity, these mechanisms are poorly understood in plants. One intriguing model derived from the algal chloroplast system, Chlamydomonas, implicates the role of three proteins (RB60, RB47, RB38) that bind to the psbAmRNA 5' untranslated leader (5' UTR) in the light to activate translation or enhance mRNA stability. RB60 is the key enzyme, protein D1sulfide isomerase (Pill), that regulates the psbA-RN :Binding proteins (RB's) by way of light-mediated redox potentials generated by the photosystems. However, proteins with these functions have not been described from higher plants. We provided compelling evidence for the existence of RB60, RB47 and RB38 orthologs in the vascular plant, Arabidopsis. Using gel mobility shift, Rnase protection and UV-crosslinking assays, we have shown that a dithiol redox mechanism which resembles a Pill (RB60) activity regulates the interaction of 43- and 30-kDa proteins with a thermolabile stem-loop in the 5' UTR of the psbAmRNA from Arabidopsis. We discovered, in Arabidopsis, the PD1 gene family consists of II members that differ in polypeptide length from 361 to 566 amino acids, presence of signal peptides, KDEL motifs, and the number and positions of thioredoxin domains. PD1's catalyze the reversible formation an disomerization of disulfide bonds necessary for the proper folding, assembly, activity, and secretion of numerous enzymes and structural proteins. PD1's have also evolved novel cellular redox functions, as single enzymes and as subunits of protein complexes in organelles. We provide evidence that at least one Pill is localized to the chloroplast. We have used PDI-specific polyclonal and monoclonal antisera to characterize the PD1 (55 kDa) in the chloroplast that is unevenly distributed between the stroma and pellet (containing membranes, DNA, polysomes, starch), being three-fold more abundant in the pellet phase. PD1-55 levels increase with light intensity and it assembles into a high molecular weight complex of ~230 kDa as determined on native blue gels. In vitro translation of all 11 different Pill's followed by microsomal membrane processing reactions were used to differentiate among PD1's localized in the endoplasmic reticulum or other organelles. These results will provide.1e insights into redox regulatory mechanisms involved in adaptation of the photosynthetic apparatus to light stress. Elucidating the genetic mechanisms and factors regulating chloroplast photosynthetic genes is important for developing strategies to improve photosynthetic efficiency, crop productivity and adaptation to high light environments.
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Ron, Eliora, i Eugene Eugene Nester. Global functional genomics of plant cell transformation by agrobacterium. United States Department of Agriculture, marzec 2009. http://dx.doi.org/10.32747/2009.7695860.bard.
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The aim of this study was to carry out a global functional genomics analysis of plant cell transformation by Agrobacterium in order to define and characterize the physiology of Agrobacterium in the acidic environment of a wounded plant. We planed to study the proteome and transcriptome of Agrobacterium in response to a change in pH, from 7.2 to 5.5 and identify genes and circuits directly involved in this change. Bacteria-plant interactions involve a large number of global regulatory systems, which are essential for protection against new stressful conditions. The interaction of bacteria with their hosts has been previously studied by genetic-physiological methods. We wanted to make use of the new capabilities to study these interactions on a global scale, using transcription analysis (transcriptomics, microarrays) and proteomics (2D gel electrophoresis and mass spectrometry). The results provided extensive data on the functional genomics under conditions that partially mimic plant infection and – in addition - revealed some surprising and significant data. Thus, we identified the genes whose expression is modulated when Agrobacterium is grown under the acidic conditions found in the rhizosphere (pH 5.5), an essential environmental factor in Agrobacterium – plant interactions essential for induction of the virulence program by plant signal molecules. Among the 45 genes whose expression was significantly elevated, of special interest is the two-component chromosomally encoded system, ChvG/I which is involved in regulating acid inducible genes. A second exciting system under acid and ChvG/Icontrol is a secretion system for proteins, T6SS, encoded by 14 genes which appears to be important for Rhizobium leguminosarum nodule formation and nitrogen fixation and for virulence of Agrobacterium. The proteome analysis revealed that gamma aminobutyric acid (GABA), a metabolite secreted by wounded plants, induces the synthesis of an Agrobacterium lactonase which degrades the quorum sensing signal, N-acyl homoserine lactone (AHL), resulting in attenuation of virulence. In addition, through a transcriptomic analysis of Agrobacterium growing at the pH of the rhizosphere (pH=5.5), we demonstrated that salicylic acid (SA) a well-studied plant signal molecule important in plant defense, attenuates Agrobacterium virulence in two distinct ways - by down regulating the synthesis of the virulence (vir) genes required for the processing and transfer of the T-DNA and by inducing the same lactonase, which in turn degrades the AHL. Thus, GABA and SA with different molecular structures, induce the expression of these same genes. The identification of genes whose expression is modulated by conditions that mimic plant infection, as well as the identification of regulatory molecules that help control the early stages of infection, advance our understanding of this complex bacterial-plant interaction and has immediate potential applications to modify it. We expect that the data generated by our research will be used to develop novel strategies for the control of crown gall disease. Moreover, these results will also provide the basis for future biotechnological approaches that will use genetic manipulations to improve bacterial-plant interactions, leading to more efficient DNA transfer to recalcitrant plants and robust symbiosis. These advances will, in turn, contribute to plant protection by introducing genes for resistance against other bacteria, pests and environmental stress.
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Lurie, Susan, John Labavitch, Ruth Ben-Arie i Ken Shackel. Woolliness in Peaches and Nectarines. United States Department of Agriculture, 1995. http://dx.doi.org/10.32747/1995.7570557.bard.
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The overall goal of the research was to understand the processes involved in the development of woolliness in peaches and nectarines. Four specific hypotheses were proposed and in the course of the research evidence was gathered t support two of them and to not support two others. The hypotheses and a summary of the evidence are outlined below. 1. That woolliness arises from an imbalance between the activities of the cell wall pectin degrading enzymes. Using 'Flavortop' nectarines and 'Hermoza' peaches as model systems, storage regimes were manipulated to induce or prevent woolliness. The expression (mRNA abundance), protein content (Western blotting), and activity of polygalacturonase (PG) and pectin esterase (PE) were followed. Expression of the enzymes was not different, but activity and the ratio between PG and PE activities were quite different in fruits developing woolliness or ripening normally. This was also examined by looking at the substrate, the pectin moiety of the cell wall, and i woolly fruit there were more high molecular weight pectins with regions of non-methylated galacturonic acid residues. Taking an in vitro approach it was found a) that PE activity was stable at 0oC while PG activity decreased; b) incubating the calcium pectate fraction of the cell wall with PE extracted from peaches caused the polymers to form a gel characteristic of the visual woolly symptoms in peaches. 2. That continued cell wall synthesis occurs during storage and contributes to structural changes i cell walls and improper dissolution and softening after storage. We tried to adapt our technique of adding 13C-glucose to fruit discs, which was used successfully to follow cell wall synthesis during tomato ripening. However, the difference in sugar content between the two fruits (4% in tomato and 12% in peach) meant that the 13C-glucose was much more diluted within the general metabolite pool. We were unable to see any cell wall synthesis which meant that either the dilution factor was too great, or that synthesis was not occurring. 3. That controlled atmosphere (CA) prevents woolliness by lowering all enzyme activities. CA was found to greatly reduce mRNA abundance of the cell wall enzymes compared to regular air storage. However, their synthesis and activity recovered during ripening after CA storage and did not after regular air storage. Therefore, CA prevented the inhibition of enzyme activation found in regular air storage. 4. That changes in cell wall turgor and membrane function are important events in the development of woolliness. Using a micro pressure probe, turgor was measured in cells of individual 'O'Henry' and 'CalRed' peaches which were woolly or healthy. The relationship between firmness and turgor was the same in both fruit conditions. These data indicate that the development and expression of woolliness are not associated with differences in membrane function, at least with regard to the factors that determine cell turgor pressure. In addition, during the period of the grant additional areas were explored. Encoglucanase, and enzyme metabolizing hemicellulose, was found to be highly expressed air stored, but not in unstored or CA stored fruit. Activity gels showed higher activity in air stored fruit as well. This is the first indication that other components of the cell wall may be involved in woolliness. The role of ethylene in woolliness development was also investigated at it was found a) that woolly fruits had decreased ability to produce ethylene, b) storing fruits in the presence of ethylene delayed the appearance of woolliness. This latter finding has implication for an inexpensive strategy for storing peaches and nectarines.
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Abdula, Andrii I., Halyna A. Baluta, Nadiia P. Kozachenko i Darja A. Kassim. Peculiarities of using of the Moodle test tools in philosophy teaching. [б. в.], lipiec 2020. http://dx.doi.org/10.31812/123456789/3867.
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The paper considers the role of philosophy and philosophical disciplines as the means of forming general cultural competences, in particular, in the development of critical thinking. The article emphasizes that the process of forming over-subject and soft skills, which, as a rule, include also critical thinking, gets much more complicated under the conditions of the reduction in the volume of philosophical courses. The paper grounds that one of the ways to “return” philosophy to educational programmes can be the implementation of training, using the e-learning environment, especially Moodle. In addition, authors point to the expediency of using this system and, in general, e-learning as an instrument for collaborating students to the world’s educational community and for developing their lifelong learning skills. The article specifies the features of providing electronic support in philosophy teaching, to which the following belongs: the difficulty of parametrizing the learning outcomes; plurality of approaches; communicative philosophy. The paper highlights the types of activities that can be implemented by tools of Moodle. The use of the following Moodle test tasks is considered as an example: test control in the flipped class, control of work with primary sources, control of self-study, test implementation of interim thematic control. The authors conclude that the Moodle system can be used as a tools of online support for the philosophy course, but it is impossible to transfer to the virtual space all the study of this discipline, because it has a significant worldview load. Forms of training, directly related to communication, are integral part of the methodology of teaching philosophy as philosophy itself is discursive, dialogical, communicative and pluralistic. Nevertheless, taking into account features of the discipline, it is possible to provide not only the evaluation function of the test control, but also to realize a number of educational functions: updating the basic knowledge, memorization, activating the cognitive interest, developing the ability to reason and the simpler ones but not less important, – the skill of getting information and familiarization with it.
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Eyal, Yoram, i Sheila McCormick. Molecular Mechanisms of Pollen-Pistil Interactions in Interspecific Crossing Barriers in the Tomato Family. United States Department of Agriculture, maj 2000. http://dx.doi.org/10.32747/2000.7573076.bard.
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During the evolutionary process of speciation in plants, naturally occurring barriers to reproduction have developed that affect the transfer of genes within and between related species. These barriers can occur at several different levels beginning with pollination-barriers and ending with hybrid-breakdown. The interaction between pollen and pistils presents one of the major barriers to intra- and inter-specific crosses and is the focus of this research project. Our long-term goal in this research proposal was defined to resolve questions on recognition and communication during pollen-pistil interactions in the extended tomato family. In this context, this work was initiated and planned to study the potential involvement of tomato pollen-specific receptor-like kinases (RLK's) in the interaction between pollen and pistils. By special permission from BARD the objectives of this research were extended to include studies on pollen-pistil interactions and pollination barriers in horticultural crops with an emphasis on citrus. Functional characterization of 2 pollen-specific RLK's from tomato was carried out. The data shows that both encode functional kinases that were active as recombinant proteins. One of the kinases was shown to accumulate mainly after pollen germination and to be phosphorylated in-vitro in pollen membranes as well as in-vivo. The presence of style extract resulted in dephosphorylation of the RLK, although no species specificity was observed. This data implies a role for at least one RLK in pollination events following pollen germination. However, a transgenic plant analysis of the RLK's comprising overexpression, dominant-negative and anti-sense constructs failed to provide answers on their role in pollination. While genetic effects on some of the plants were observed in both the Israeli and American labs, no clear functional answers were obtained. An alternative approach to addressing function was pursued by screening for an artificial ligand for the receptor domain using a peptide phage display library. An enriched peptide sequence was obtained and will be used to design a peptide-ligand to be tested for its effect o pollen germination and tube growth. Self-incompatibility (SI) in citrus was studied on 3 varieties of pummelo. SI was observed using fluorescence microscopy in each of the 3 varieties and compatibility relations between varieties was determined. An initial screen for an S-RNase SI mechanism yielded only a cDNA homologous to the group of S-like RNases, suggesting that SI results from an as yet unknown mechanism. 2D gel electrophoresis was applied to compare pollen and style profiles of different compatibility groups. A "polymorphic" protein band from style extracts was observed, isolated and micro-sequenced. Degenerate primers designed based on the peptide sequence date will be used to isolate the relevant genes i order to study their potential involvement in SI. A study on SI in the apple cultivar Top red was initiated. SI was found, as previously shown, to be complete thus requiring a compatible pollinator variety. A new S-RNase allele was discovered fro Top red styles and was found to be highly homologous to pear S-RNases, suggesting that evolution of these genes pre-dated speciation into apples and pears but not to other Rosaceae species. The new allele provides molecular-genetic tools to determine potential pollinators for the variety Top red as well as a tool to break-down SI in this important variety.
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Lewis, Sherman, Emilio Grande i Ralph Robinson. The Mismeasurement of Mobility for Walkable Neighborhoods. Mineta Transportation Institute, listopad 2020. http://dx.doi.org/10.31979/mti.2020.2060.
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The major US household travel surveys do not ask the right questions to understand mobility in Walkable Neighborhoods. Yet few subjects can be more important for sustainability and real economic growth based on all things of value, including sustainability, affordability, and quality of life. Walkable Neighborhoods are a system of land use, transportation, and transportation pricing. They are areas with attractive walking distances of residential and local business land uses of sufficient density to support enough business and transit, with mobility comparable to suburbia and without owning an auto. Mobility is defined as the travel time typically spent to reach destinations outside the home, not trips among other destinations that are not related to the home base. A home round trip returns home the same day, a way of defining routine trips based on the home location. Trip times and purposes, taken together, constitute travel time budgets and add up to total travel time in the course of a day. Furthermore, for Walkable Neighborhoods, the analysis focuses on the trips most important for daily mobility. Mismeasurement consists of including trips that are not real trips to destinations outside the home, totaling 48 percent of trips. It includes purposes that are not short trips functional for walk times and mixing of different trips into single purposes, resulting in even less useful data. The surveys do not separate home round trips from other major trip types such as work round trips and overnight trips. The major household surveys collect vast amounts of information without insight into the data needed for neighborhood sustainability. The methodology of statistics gets in the way of using statistics for the deeper insights we need. Household travel surveys need to be reframed to provide the information needed to understand and improve Walkable Neighborhoods. This research makes progress on the issue, but mismeasurement prevents a better understanding of the issue.
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Elroy-Stein, Orna, i Dmitry Belostotsky. Mechanism of Internal Initiation of Translation in Plants. United States Department of Agriculture, grudzień 2010. http://dx.doi.org/10.32747/2010.7696518.bard.
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Original objectives Elucidation of PABP's role in crTMV148 IRES function in-vitro using wheat germ extract and krebs-2 cells extract. Fully achieved. Elucidation of PABP's role in crTMV148 IRES function in-vivo in Arabidopsis. Characterization of the physical interactions of PABP and other potential ITAFs with crTMV148 IRES. Partly achieved. To conduct search for additional ITAFs using different approaches and evaluate the candidates. Partly achieved. Background of the topic The power of internal translation via the activity of internal ribosomal entry site (IRES) elements allow coordinated synthesis of multiple gene products from a single transcription unit, and thereby enables to bypass the need for sequential transformation with multiple independent transgenes. The key goal of this project was to identify and analyze the IRES-trans-acting factors (ITAFs) that mediate the activity of a crucifer-infecting tobamovirus (crTMV148) IRES. The remarkable conservation of the IRES activity across the phylogenetic spectrum (yeast, plants and animals) strongly suggests that key ITAFs that mediate its activity are themselves highly conserved. Thus, crTMV148 IRES offers opportunity for elucidation of the fundamental mechanisms underlying internal translation in higher plants in order to enable its rational manipulation for the purpose of agricultural biotechnology. Major conclusions and achievements. - CrTMV IRES requires PABP for maximal activity. This conclusion was achieved by PABP depletion and reconstitution of wheat germ- and Krebs2-derived in-vitro translation assays using Arabidopsis-derived PABP2, 3, 5, 8 and yeast Pab1p. - Mutations in the internal polypurine tract of the IRES decrease the high-affinity binding of all phylogenetically divergent PABPs derived from Arabidopsis and yeast in electro mobility gel shift assays. - Mutations in the internal polypurine tract decrease IRES activity in-vivo. - The 3'-poly(A) tail enhances crTMV148 IRES activity more efficiently in the absence of 5'-methylated cap. - In-vivo assembled RNPs containing proteins specifically associated with the IRES were purified from HEK293 cells using the RNA Affinity in Tandem (RAT) approach followed by their identification by mass spectroscopy. - This study yielded a list of potential protein candidates that may serve as ITAFs of crTMV148 IRES activity, among them are a/b tubulin, a/g actin, GAPDH, enolase 1, ribonuclease/angiogenin inhibitor 1, 26S proteasome subunit p45, rpSA, eEF1Bδ, and proteasome b5 subunit. Implications, both scientific and agriculture. The fact that the 3'-poly(A) tail enhances crTMV148 IRES activity more efficiently in the absence of 5'-methylated cap suggests a potential joint interaction between PABP, the IRES sequence and the 3'-poly(A). This has an important scientific implication related to IRES function in general.
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Ginzberg, Idit, i Walter De Jong. Molecular genetic and anatomical characterization of potato tuber skin appearance. United States Department of Agriculture, wrzesień 2008. http://dx.doi.org/10.32747/2008.7587733.bard.
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Potato (Solanum tuberosum L.) skin is composed of suberized phellem cells, the outer component of the tuber periderm. The focus of the proposed research was to apply genomic approaches to identify genes that control tuber skin appearance - smooth and shiny skin is highly preferred by the customers while russeted/netted skin potatoes are rejected. The breeding program (at Cornell University) seeks to develop smooth-skin varieties but has encountered frequent difficulties as inheritance of russeting involves complementary action by independently segregating genes, where a dominant allele at each locus is required for any degree of skin russeting. On the other hand, smooth-skin varieties frequently develop unsightly russeting in response to stress conditions, mainly high soil temperatures. Breeding programs in Israel aimed towards the improvement of heat tolerant varieties include skin quality as one of the desired characteristics. At the initiation of the present project it was unclear whether heat induced russeting and genetically inherited russeting share the same genes and biosynthesis pathways. Nevertheless, it has been suggested that russeting might result from increased periderm thickness, from strong cohesion between peridermal cells that prevents the outer layers from sloughing off, or from altered suberization processes in the skin. Hence, the original objectives were to conduct anatomical study of russet skin development, to isolate skin and russeting specific genes, to map the loci that determine the russet trait, and to compare with map locations the candidate russet specific genes, as well as to identify marker alleles that associated with russet loci. Anatomical studies suggested that russet may evolve from cracking at the outer layers of the skin, probably when skin development doesn’t meet the tuber expansion rate. Twodimensional gel electrophoresis and transcript profiling (cDNA chip, potato functional genomic project) indicated that in comparison to the parenchyma tissue, the skin is enriched with proteins/genes that are involved in the plant's responses to biotic and abiotic stresses and further expand the concept of the skin as a protective tissue containing an array of plantdefense components. The proteomes of skin from heat stressed tubers and native skin didn’t differ significantly, while transcript profiling indicated heat-related increase in three major functional groups: transcription factors, stress response and protein degradation. Exceptional was ACC synthase isogene with 4.6 fold increased level in the heat stressed skin. Russeting was mapped to two loci: rusB on chromosome 4 and rusC on chromosome 11; both required for russeting. No evidence was found for a third locus rusA that was previously proposed to be required for russeting. In an effort to find a link between the russeting character and the heat-induced russeting an attempt was made to map five genes that were found in the microarray experiment to be highly induced in the skin under heat stress in the segregating russet population. Only one gene was polymorphic; however it was localized to chromosome 2, so cannot correspond to rusB or rusC. Evaluation of AFLP markers tightly linked to rusB and rusC showed that these specific alleles are not associated with russeting in unrelated germplasm, and thus are not useful for MAS per se. To develop markers useful in applied breeding, it will be necessary to screen alleles of additional tightly linked loci, as well as to identify additional russet (heat-induced and/or native) related genes.