Дисертації з теми "Amide function"
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1
Knapper, Jacqueline M. E. "Evaluation of GIP and intestinal GLP-1(7-36)amide function in hyperphagic states." Thesis, University of Surrey, 1992. http://epubs.surrey.ac.uk/651/.
Повний текст джерела
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Tosi, Eleonora. "Nouvelles opportunités pour la synthèse peptidique." Electronic Thesis or Diss., Montpellier, Ecole nationale supérieure de chimie, 2022. http://www.theses.fr/2022ENCM0008.
Повний текст джерелаАнотація:
Les peptides et les protéines sont des biomolécules essentielles, impliquées dans des nombreux processus physiologiques. Outre ces processus vitaux, ces molécules sont très étudiées et attirent l’attention dans des domaines aussi différents que la chimie médicinale, les polymères et les matériaux. Par conséquent, la maîtrise de leur production, notamment par synthèse chimique, est primordiale.Dans ce contexte, notre laboratoire a développé une méthode originale pour la synthèse de dipeptides basée sur un nouveau mode d’activation (activation de la fonction amine au lieu de la fonction acide carboxylique). Malheureusement malgré tous les avantages apportés par cette méthodologie, elle présente certains inconvénients tels que des temps de réaction très long.Mon projet de thèse se concentre d’abord sur l’amélioration de cette méthodologie, avec une attention particulière pour la cinétique de la réaction et ensuite évaluer la possible application de celle-ci dans le cadre des amides généraux. Donc, dans un premier temps il était important d’étudier à fond la réaction en changeant les paramètres pour essayer d’optimiser les conditions en réduisant le temps de réaction en conservant un très bon rendement ainsi que tester différents additifs ou encore étudier plusieurs nouveaux agents de couplage, ou changer la dilution du milieu réactionnel etc. En termes de cinétique de réaction, nous avons pu constater que la réaction pouvait avoir lieu en 30 minutes au lieu de 20 heures par le biais de micro-ondes. Finalement, après avoir modifié les conditions de réaction, la synthèse d'amides généraux a été réalisée en obtenant les produits avec des bons rendements.En parallèle, nous nous sommes intéressés à l’expansion des petits cycles via les métaux de transition qui repose sur le réarrangement des aziridines et se déroule dans des conditions douces pour arriver à la formation de 3-pyrrolinesPeptides and proteins are amongst the essential molecules in the everyday life. Consequently, they are widely investigated and used in several synthetic and natural-derived materials covering a broad range of applications. Hence, mastering their production, especially by chemical synthesis, is of utmost importance.Our group has proposed an original procedure for the formation of amides on the basis of a novel mode of activation (“inverse activation” of AA through the amine function) affording the synthesis of several dipeptides. Nonetheless, this methodology presents some main drawbacks such as the long time to complete the reaction.This PhD thesis work focuses on improving this methodology to synthesise peptide targets and to be able to extend the methodology to the synthesis of “general” (no-amino acids substrates) amides. To accomplish our aim, we examined the different parameters of the peptide coupling such as the solvent, the concentration, the activating reagent, the additives and the time of the reaction. For instance, in terms of reaction kinetics we were delighted to observe that the reaction could take place in only 30 minutes instead of 20 hours using microwave irradiation. Moreover, we found that the additives used for the reaction (CuBr2/HOBt 10 mol% each) could be replaced by a catalytic amount of trifluoroacetic acid in a more diluted solution to give dipeptides in good yield (in the absence of a transition metal). Then, we focus our attention on the synthesis of general amides. Once the reaction conditions were optimised, we explored the scope of the substrate obtaining the desired products in good yield showing the versatility of this methodology.In parallel, we realised another project on the ring-expansion of the vinyl aziridines in order to afford the formation of 3-pyrrolines, interesting building blocks in organic synthesis
3
Delgado, Aros Sílvia. "Effects of Glucagon-like Peptide-1-(7-36)amide (GLP-1) on Gastric Motor Function in Health and Diabetes: Potential Mechanism of Action." Doctoral thesis, Universitat Autònoma de Barcelona, 2003. http://hdl.handle.net/10803/4416.
Повний текст джерелаАнотація:
El Glucagon-like peptide-1 (GLP-1), un pèptid derivat del processament del proglucagó en les cè_lules L del jejúnum i del colon, inhibeix la secreció àcida gàstrica i el buidament gàstric, a més de reduir la capacitat d'ingesta. Els mecanismes d'acció del GLP-1 no estan clars. Hi ha dades que suggereixen que la inhibició de les funcions gàstriques per part del GLP-1 estan mitjançades pel nervi vagus.L'acomodació o relaxació gàstrica en resposta a la ingesta és un reflex mitjançat pel vagus que dóna lloc a un increment del volum o capacitat gàstrica que impedeix l'increment de la pressió intragàstrica quan mengem, evitant així l'aparició de símptomes. La primera hipòtesi que vàrem plantejar va ser que el GLP-1 inhibeix el reflex d'acomodació gàstrica i que això explicaria en part la reducció de la capacitat d'ingesta que s'observa en administrar el GLP-1. Per provar aquesta hipòtesi vàrem comparar els efectes d'una infusió endovenosa de GLP-1 i placebo, en voluntaris sans, sobre l'acomodació gàstrica postprandial (mesurada amb la tècnica SPECT), l'increment postprandial del polipèptid pancreàtic (marcador de funció vagal abdominal) i el volum d'un nutrient líquid (Ensure®) ingerit fins atansar la sacietat màxima. Els resultats del primer estudi van demostrar que el GLP-1 no inhibeix l'acomodació gàstrica postprandial; al contrari, va augmentar el volum gàstric en dejú i després del menjar. Això es va acompanyar per una marcada inhibició de la secreció de polipèptid pancreàtic, la qual està sota control vagal colinèrgic. Degut a que el to gàstric està mantingut per influència colinèrgica vagal, els resultats obtinguts són compatibles amb la hipòtesi de que el GLP-1 indueix relaxació gàstrica (augment de volum gàstric) per inhibició de les vies colinèrgiques vagals. Si aquesta hipòtesi fos certa, en cas de disfunció vagal o vagotomia, el GLP-1 no produiria relaxació gàstrica (augment de volum gàstric).
Per provar aquesta segona hipòtesi, vàrem estudiar l'efecte de la mateixa infusió endovenosa de GLP-1, comparada amb placebo, en els volums gàstrics de subjectes amb neuropatia vagal diabètica. Vàrem comparar també els volums gàstrics dels malalts diabètics que rebien placebo amb els dels subjectes sans estudiats en el primer estudi presentat en aquesta tesi. Al contrari del que vàrem observar en subjectes sans, el GLP-1 no va augmentar el volum gàstric en malalts diabètics amb neuropatia vagal. Això suggereix que l'efecte del GLP-1 sobre el volum gàstric està mitjançat pel nervi vagus.
Els malalts diabètics avaluats presentaven volums gàstrics, tan en dejú com després del menjar, similars als dels subjectes sans. El nervi vagus participa en el control del to o volum gàstric, però hi ha altres mecanismes que també hi participen. Es més, hi ha evidència de que el to gàstric pot ser controlat adequadament en absència de innervació vagal extrínseca. De manera que la troballa de la existència de volums gàstrics normals en malalts amb neuropatia vagal s'afegeix a la evidència de que, en cas d'alteració del reflex principal vago-vagal, es produeix un mecanisme adaptatiu per preservar la resposta de relaxació gàstrica postprandial.
Glucagon-like peptide-1 (GLP-1), a peptide derived from the processing of the proglucagon molecule in L cells of the jejunum and colon, inhibits gastric acid secretion and gastric emptying rate and it also decreases food consumption. It is still not clear how these effects of GLP-1 are mediated. There are data that suggest that GLP-1 inhibition of upper gastrointestinal functions is mediated through the vagus nerve.
The accommodation or relaxation of the stomach in response to meal ingestion is a vagally-mediated reflex that increases gastric volume. This prevents the increase in intragastric pressure when food and fluid enter in the stomach, avoiding the development of symptoms.
We hypothesized that GLP-1 inhibits the gastric accommodation reflex and that this effect could partly explain the reduced food consumption with GLP-1. To test this hypothesis, we compared, in healthy volunteers, the effects of intravenous infusion of GLP-1 and placebo, on postprandial gastric accommodation (as measured by the SPECT technique), postprandial response of plasma human pancreatic polypeptide (a surrogate marker of vagal abdominal function) and the volume of a nutrient liquid meal (Ensure_) ingested at maximum satiation. The results of the first study showed that GLP-1 does not inhibit postprandial gastric accommodation; on the contrary, it increased fasting and postprandial gastric volumes. This was accompanied by a marked inhibition of the pancreatic polypeptide release, which is under vagal cholinergic control. Since gastric tone is maintained by vagal cholinergic input, the results observed in our first study suggested that GLP-1 could induce gastric relaxation (increase gastric volume) by inhibition of vagal cholinergic pathways. If this hypothesis were true, one would predict that in the presence of vagal dysfunction or vagotomy, GLP-1 would not induce gastric relaxation (increase gastric volume).
To test this second hypothesis we studied the effect of the same intravenous infusion of GLP-1, compared to placebo, on gastric volumes in a sample of subjects with diabetes affected with vagal neuropathy. We also compared gastric volumes in diabetic patients on placebo to those in the healthy subjects who participated in the first study presented in this thesis. In contrast to effects in health, GLP-1 did not increase gastric volume in diabetics with vagal neuropathy. This suggests that the effect of GLP-1 on gastric volume is dependent on vagal function.
The diabetic patients evaluated had gastric volumes similar to those of healthy controls. The vagus nerve participates in the control of gastric volume or tone; however, there are other mechanisms involved. Furthermore, there is increasing evidence that gastric tone may be adequately controlled in the absence of extrinsic vagal innervation. Thus, we believe that the normal gastric volume response to a meal observed in the presence of vagal neuropathy adds to the growing evidence of the existence of an adaptive response preserving postprandial gastric relaxation when the main vago-vagal reflex is impaired.
4
May, Alexander T. "Identification of Expression and Function of the Glucagon-like Peptide-1 Receptor in Gastrointestinal Smooth Muscle." VCU Scholars Compass, 2017. http://scholarscompass.vcu.edu/etd/4886.
Повний текст джерелаАнотація:
In response to ingestion of nutrients, enteroendocrine L cells secrete the incretin hormone, glucagon-like peptide-1 (GLP-1), to enhance glucose-dependent insulin release. Therapies related to GLP-1 are approved for type 2 diabetes. The GLP-1 receptor (GLP-1R) is expressed in cells of the gastrointestinal tract and elsewhere. In pancreatic beta cells, GLP-1R are coupled to the Gs/cAMP/PKA pathway. The expression and function of GLP-1R in gastrointestinal smooth muscle are not known. Aim. To test the hypothesis that GLP-1 regulates smooth muscle function by acting on GLP-1R expressed on smooth muscle. Methods. Smooth muscle cells (SMC) were isolated and cultured. Expression of GLP-1R mRNA was measured by RT-PCR. Expression of GLP-1R protein was measured by western blot. The effect of GLP-1 (7-36) amide on Gαs activation, cAMP formation, and PKA activity was examined in cultured SMC. The effect of GLP-1 on basal activity and on acetylcholine-induced contraction was measured in intact colon via organ bath. Results. Amplification of GLP-1R mRNA suggested expression of GLP-1R mRNA in mucosal and non-mucosal colon cells, which was confirmed in pure SMC cultures. Similar patterns of protein expression were obtained with western blot. Addition of GLP-1 caused relaxation of phasic activity and agonist-induced tonic contractions in intact colon, suggesting a role of smooth muscle Gs-coupled GLP-1R in mediating relaxation. In SMC, GLP-1 (7-36) amide activated Gas, increased cAMP levels, and stimulated PKA activity. Conclusion. Colonic SMC express GLP-1R, and GLP-1 inhibits both basal and acetylcholine-induced contraction. The GLP1-R is coupled to the heterotrimeric G protein, Gas.
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Kim, Sang-Chul. "Functional Characterization of Plant Fatty Acid Amide Hydrolases." Thesis, University of North Texas, 2010. https://digital.library.unt.edu/ark:/67531/metadc33177/.
Повний текст джерелаАнотація:
Fatty acid amide hydrolase (FAAH) terminates the endocannabinoid signaling pathway that regulates numerous neurobehavioral processes in animals by hydrolyzing a class of lipid mediators, N-acylethanolamines (NAEs). Recent identification of an Arabidopsis FAAH homologue (AtFAAH) and several studies, especially those using AtFAAH overexpressing and knock-out lines suggest that a FAAH-mediated pathway exists in plants for the metabolism of endogenous NAEs. Here, I provide evidence to support this concept by identifying candidate FAAH cDNA sequences in diverse plant species. NAE amidohydrolase assays confirmed that several of the proteins encoded by these cDNAs indeed catalyzed the hydrolysis of NAEs in vitro. Kinetic parameters, inhibition properties, and substrate specificities of the plant FAAH enzymes were very similar to those of mammalian FAAH. Five amino acid residues determined to be important for catalysis by rat FAAH were absolutely conserved within the plant FAAH sequences. Site-directed mutation of each of the five putative catalytic residues in AtFAAH abolished its hydrolytic activity when expressed in Escherichia coli. Contrary to overexpression of native AtFAAH in Arabidopsis that results in enhanced seedling growth, and in seedlings that were insensitive to exogenous NAE, overexpression of the inactive AtFAAH mutants showed no growth enhancement and no NAE tolerance. However, both active and inactive AtFAAH overexpressors displayed hypersensitivity to ABA, suggesting a function of the enzyme independent of its catalytic activity toward NAE substrates. Yeast two-hybrid screening identified Arg/Ser-rich zinc knuckle-containing protein as a candidate protein that physically and domain-specifically interacts with AtFAAH and its T-DNA knock-out Arabidopsis was hypersensitive to ABA to a degree similar to AtFAAH overexpressors. Taken together, AtFAAH appears to have a bifurcating function, via NAE hydrolysis and protein-protein interaction, to control Arabidopsis growth and interaction with phytohormone signaling pathways. These studies help to functionally define the group of enzymes that metabolize NAEs in plants, and further will expand the knowledge-base of lipid metabolism and signaling for manipulation of various physiological processes important to plant growth and responses to environmental stress.
6
Uemura, Kazuhiro. "Studies on crystal structures and functions of amide group-containing coordination polymers." 京都大学 (Kyoto University), 2004. http://hdl.handle.net/2433/59326.
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Ortmayer, Mary. "Structure and function of an unusual heme dependent secondary amine oxidase." Thesis, University of Manchester, 2014. https://www.research.manchester.ac.uk/portal/en/theses/structure-and-function-of-an-unusual-heme-dependent-secondary-amine-oxidase(2171f7d9-a40d-4605-85ff-452c4f30b551).html.
Повний текст джерелаАнотація:
The orphan enzyme “secondary amine monooxygenase (SAMO)” catalyses the N- dealkylation of dimethylamine (DMA) to methylamine and formaldehyde using NADPH and oxygen. It is described in the literature as a heme-dependent monooxygenase enzyme, similar in terms of the overall reaction catalysed to the well- characterised cytochrome P450s (CYPs). However, the SAMO heme is without the essential CYP thiolate ligand, featuring the more common histidine-ligation instead. During a study of bacterial operons containing H4F-binding modules, the genes encoding for SAMO were discovered. It was found that four genes αβγδ encode for the heterotetrameric SAMO. While sequence similarities indicate α encodes for an H4F- aminomethyltransferase module, and γ for an NADPH/FMN/2Fe2S reductase module, the function of β and δ genes was unclear. Spectral analysis of the Rhizobium etli CFN 42 δ-subunit reveals it to be the heme-binding domain (δRe), with the cofactor-free β- subunit responsible for enhanced DMA binding by the βδRe complex. DMA has the highest affinity for ferrous-oxy δRe, indicating close interaction between the dioxygen and DMA. Both δRe and βδRe have a positive redox potential supporting formation of a relatively stable dioxygen complex. Holoenzyme SAMO from Pseudomonas mendocina ymp (αβγδPm) demonstrates DMA dependent NADPH oxidation and formaldehyde production, but is inherently unstable. The crystal structure of SAMO heme domain from P. mendocina (δPm) reveals a heme-binding PAS domain. Capitalising on the 1.9 Å ternary complex structure with DMA and nitric oxide, a model of the SAMO catalytic mechanism was proposed. Conserved active site residues including Trp180 and Glu266 (involved in substrate binding), in addition to Arg224 were mutated, each rendering αβγδPm inactive. It is proposed that the positively charged amine substrate works in concert with conserved Arg224 residue to create a polarised active site, supporting heterolytic cleavage of the O-O bond. However, unlike other heme enzymes SAMO lacks a strong electronegative proximal ligand. In view of this, it is proposed SAMO catalyses an oxidase-type reaction, leading to a transient iminium species, in the absence of substrate oxygen insertion. To the best of current understanding, SAMO appears to be a novel type of PAS domain that performs an oxidase reaction with oxygen activation facilitated by the secondary amine substrate.
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Hassan, Enas. "Development of amine functional hydrogels for corneal regeneration." Thesis, University of Sheffield, 2014. http://etheses.whiterose.ac.uk/8468/.
Повний текст джерелаАнотація:
The aim of this thesis was to develop a synthetic polymethacrylate based hydrogel capable of regenerating a corneal epithelium for the purposes of treating blindness caused by limbal stem cell deficiency. Deficiency of limbal epithelial cells (LECs) causes conjunctival epithelial cells to move over the cornea, resulting in painful scaring, vascularisation and corneal opacity. Unilateral defects can be treated using LEC cultured from the unaffected eye, transplanting them to the affected cornea after scar tissue is removed. The underlying wound bed is often damaged, however, hence the need to develop a corneal inlay to aid in corneal re-epithelialisation, while replacing damaged stromal tissue. Transparent epoxy-functional polymethacrylate networks were synthesised using a combination of glycerol monomethacrylate, ethylene glycol dimethacrylate, lauryl methacrylate and glycidyl methacrylate that produced different bulk hydrogel compositions or “Bases” with different equilibrium water contents (EWC) (Base 0, 1 and 2) and different quantities of epoxy functionality (Bases 1.B, 1.15, 1.20 and 1.30). Sets of amine-functional hydrogels were produced following reaction of the epoxide groups with excesses of ammonia, 1,2-diamino ethane, 1,3-diamino propane, 1,4-diamino butane or 1,6- diamino hexane. The gels were assessed for their capacity to support the growth and proliferation for both rabbit limbal fibroblasts (rLFs) and rabbit limbal epithelial cells (rLECs). Overall no series of hydrogels supported the proliferation of rLFs irrespective of amine functionalisation, however gels functionalised with longer alkyl amines supported the adhesion and proliferation of rLECs, particularly when functionalised with 1,4-diamino butane. With Base 1 hydrogels (less so with Bases 0 and 2) a vigorous epithelial outgrowth was seen from small limbal explants and a confluent epithelial layer was achieved in vitro within 6 days. The data in this thesis support the development of hydrogels capable of selectively regenerating corneal epithelium with minimal stromal cell contamination.
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Risser, Fanny. "Études d’un mécanisme enzymatique et d’interactions inter-protéiques au sein de voies complexes de biosynthèse de polycétides Characterization of Intersubunit Communication in the Virginiamycin trans-Acyl Transferase Polyketide Synthase Understanding Intersubunit Interactions in the Enacyloxin Mixed cis- /trans-acyltransferase Modular Polyketide Synthase Insights into a dual function amide oxidase/macrocyclase form lankacidin biosynthesis." Thesis, Université de Lorraine, 2019. http://www.theses.fr/2019LORR0296.
Повний текст джерелаАнотація:
Les polycétides sont des métabolites secondaires produits par divers organismes et présentant un large spectre d'activité thérapeutique. L'organisation modulaire des enzymes responsables de leur synthèse, les polycétides synthases (PKS), en font des cibles attrayantes pour la biologie synthétique visant l'obtention de nouvelles structures de polycétides. L’une des stratégies les plus prometteuses à ce jour consiste à échanger des sous-unités entières entre différents systèmes PKS. Cependant, le succès de cette stratégie dépend essentiellement de la compréhension et de l’utilisation des domaines de docking. Ces petits éléments structuraux, situés aux extrémités C- et N-terminales des sous-unités de PKS, sont responsables de leur bon appariement et donc du transfert correct de l’intermédiaire polycétidique. Pour approfondir nos connaissances sur les DD, nous avons étudié plusieurs interfaces entre sous-unités de PKS trans-AT et cis-AT. Ces travaux ont notamment conduit à l'identification de la première classe de DD chez les PKS trans-AT, et nous avons pu caractériser une interface complète, formée entre deux sous-unités consécutives au sein de la PKS virginiamycine. De plus, nous avons montré qu’au moins un des DD de paires appariées est souvent une région intrinsèquement désordonnée (IDR), ce mode de reconnaissance permet d’assurer une interaction spécifique couplée à une affinité moyenne. En effet, chez l’enacyloxine synthase, une PKS hybride cis-AT/trans-AT, les six interfaces de docking sont médiées par une IDR C-terminal. En outre, nous avons démontré que ce système présentait plusieurs classes structurales de DD, mais que des variations du code électrostatique au sein d’une classe individuelle pouvaient également être utilisées pour garantir la spécificité. Ensemble, ces résultats fournissent des indications importantes pour les futures tentatives d’utilisation des DD en ingénierie des sous-unités de PKS. Une autre stratégie innovante permettant d’obtenir de nouveaux dérivés polycétidiques, consiste à utiliser des enzymes post-PKS. Ces dernières modifient de manière extensive l’intermédiaire et lui confèrent bien souvent son activité biologique. Dans ce contexte, nous avons étudié LkcE, une enzyme bi-fonctionnelle qui catalyse une réaction rare d’oxydation d’amide, suivie d’une réaction de Mannich intramoléculaire. Nous avons résolu quatre structures cristallographiques de l’enzyme et ces données couplées aux études cinétiques, nous ont permis de proposer un mécanisme catalytique détaillé pour LkcE, impliquant un changement conformationnel à grande échelle de l'enzyme pour amener le substrat à une conformation de pré-cyclisation. De plus, nous avons démontré que LkcE possède une certaine tolérance vis-à-vis de la structure de son substrat, suggérant son utilité comme catalyseur général de cyclisation/ligation en biologie synthétique et synthèse chimiqueComplex polyketides are secondary metabolites which are produced by a range of different organisms, and which present a broad spectrum of therapeutic activity. The modular organization of the enzymes responsible for their synthesis, the polyketide synthases (PKS), makes them attractive targets for synthetic biology aimed at obtaining new polyketide structures. One of the most promising strategies to date consists in swapping of whole sub-units between different PKS systems. However, the success of this strategy critically depends on understanding and exploiting ‘docking domains’ the protein sequences at the C- and N-terminal extremities of the subunits which are responsible for correctly ordering the polypeptides, and therefore for faithful chain transfer. To increase our knowledge of DDs, we investigated several interfaces in both trans-AT and cis-AT PKSs. This work led notably to the identification of the first family of DDs from trans-AT PKSs, and we were further able to characterize a complete interface formed between two consecutive subunits within the virginiamycin PKS. In addition, we showed that at least one DD of matched pairs is often an intrinsically disordered region (IDR), as this type of interaction motif allows for specific but medium affinity contacts. Indeed, in the enacyloxin hybrid cis-AT/trans-AT PKS which we also investigated extensively, docking at every interface is mediated by a C-terminal IDR. In addition, we demonstrated that multiple structural classes of DD are present within the system, but that variations of the electrostatic ‘code’ within an individual structural class can also be used to ensure specificity. Taken together, these results provide important guidelines for future attempts to deploy DDs in subunit engineering. Another attractive target for synthetic biology are the so-called ‘post-PKS’ enzymes, which chemically decorate the initially-formed structure, and are often essential for their bioactivity. In this context, we studied LkcE, a bi-functional enzyme that catalyzes a rare amide oxidation followed by an intramolecular Mannich reaction to yield the lankacidin macrocycle – both to understand its unusual mechanism and to evaluate its suitability as a general polyketide modifying enzyme. We solved four crystal structures of the enzyme, and characterized it kinetically. Together, our data allowed us to propose a detailed catalytic mechanism for LkcE, involving a large-scale conformational change of the enzyme to bring the substrate into a cyclisation-ready state. Moreover, we showed that LkcE displays a certain tolerance toward its substrate structures, suggesting its usefulness as a general catalyst for cyclisation/ligation reaction in synthetic biology and chemical synthesis
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Voss, Rebecca. "Mesoporous organosilica materials with amine functions surface characteristics and chirality /." [S.l. : s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=975976362.
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Voß, Rebecca. "Mesoporous organosilica materials with amine functions : surface characteristics and chirality." Phd thesis, Universität Potsdam, 2005. http://opus.kobv.de/ubp/volltexte/2005/528/.
Повний текст джерелаАнотація:
In this work mesoporous organisilica materials are synthesized through the silica sol-gel process. For this a new class of precursors which are also surfactant are synthesized and self-assembled. This leads to a high surface area functionality which is analysized with copper (II) and water adsorption.Im Rahmen dieser Arbeit werden mesoporöse Amin-funktionalisierte Organo-Silikate durch den Silika Sol-Gel Prozess hergestellt. Dabei werden neue Alkoxysilyl-Precursoren synthetisiert und condensiert die die gewünschte Funktion auf die Oberfläche dirigieren. Herstellt werden primäre, secundäre und chirale Amine. Die Oberflächenfunktionalität wird mit Kupfer (II) und Wasser Adsorption analysiert.
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Lengkeek, Nigel Andrew. "Functional cage-amine complexes : polymerisable metallomonomers and multi-cage complexes." University of Western Australia. School of Biomedical, Biomolecular and Chemical Sciences, 2008. http://theses.library.uwa.edu.au/adt-WU2008.0138.
Повний текст джерелаАнотація:
[Truncated abstract] Chapter 1 provides an introduction to the 'sarcophagine' class of ligands and the field of metallopolymers. The synthesis, stereochemistry, physical properties and functionalisation of 'sarcophagines' and their metal complexes are discussed. A brief overview of the burgeoning field of metallopolymers is given with specific mention of the synthetic routes to pendant metallopolymers, and how these could be employed to prepared cage amine containing metallopolymers. Chapter 2 deals with the synthesis, characterisation and reactivity of cinnamylamino and styrylamido derivatives of the cage amines [Co((NH2)2sar)]3+, [Co((CH3)(NH2)sar)]3+ and [Cu((NH2)2sar)]2+. The cinnamylamino derivatives were prepared using reductive alkylation of the aforementioned amines with cinnamaldehyde. Procedures were developed to isolate the complexes without causing unwanted additions to the double bond. The cinnamylamino derivatives displayed unexpected reactivity towards a range of reducing agents, resulting in unexpected reduction of the double bond and cleavage of the cinnamyl group, but ultimately in the preparation of phenylpropylamino derivatives of [Co((NH2)2sar)]3+ and [Co((CH3)(NH2)sar)]3+. Attempts to rationalise the reactivity of the double bond have been explored based upon the physical properties and reactivity of the double bond. The styrylamido derivatives were prepared by treatment of the cage amines with 4-vinylbenzoyl chloride, and the complexes isolated in a similar manner to those of the cinnamylamino derivatives to ensure the amide linkage remained intact. Most of the complexes have been structurally characterised. ... Both the 2-thienyl and 3-thienyl derivatives of [Co((NH2)2sar)]3+ and [Co((CH3)(NH2)sar)]3+ have been prepared using reductive alkylation with the respective carboxaldehydes of thiophene. One of the optically pure isomers has been prepared. The complexes have been fully characterised including structural characterisation. Polymerisation of the thiophene-cage amine complexes was investigated under a range of chemical and electrochemical conditions, though polymerisation was never observed. Cleavage of the thienyl groups was observed when ceric ammonium nitrate in nitric acid was used as the oxidant. The attachment of oligothiophenes and mixed pyrrole-thiophene oligomers to cage amines were investigated using reductive alkylation and various pyrrole ring-forming reactions about the apical amino groups, though none of the desired complexes were isolated, reasons for the lack of reactivity were discussed. An efficient synthesis of N-(4-benzoic acid)- 2,5-di(2-thienyl)pyrrole was developed and was shown to the electropolymerisable, albeit the polymer films were non-conducting. Attempts to couple N-(4-benzoic acid)- 2,5-di(2-thienyl)pyrrole with a cage amine via its acid chloride were complicated by decomposition reactions, the nature of one of these products is discussed. Chapter 5 presents investigations into the preparation of simple complexes containing multiple cage amines using alkylation and acylation procedures with aromatic substrates. The complexes were found to exhibit some interesting electrochemical and chemical properties, demonstrating that even simple multiple cage amine species can display complicated and interesting behaviour.
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Elliot, Jonathan. "Semicarbazide-sensitive amine oxidase of blood vessels : a functional study." Thesis, University of Cambridge, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.316733.
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Atkinson, Daniel Edward. "The functional role of the trace amine 1 receptor in rode." Thesis, University of Nottingham, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.594216.
Повний текст джерелаАнотація:
The monoamines play important roles as neurotransmitters both centrally and peripherally, and are believed to play a key role in a number of pathological conditions such as Parkinson's disease, schizophrenia, drug addiction, and mood disorders, which has driven many years of research, resulting in a relatively good understanding of the neurochemistry of this group of amines. [n contrast, relatively little is known about the role of a second class of endogenous amines, the 'trace amines, that share substantial overlap with the monoamines. For 30 years the trace amines, have also been thought to be associated with affective behaviour, paranoid chronic schizophrenia and depression. However, until the recent discovery of a novel family Gprotein- coupled receptors (GPCRs), with high affinity for the trace amines, research was restricted. One member of this family, trace amine 1 receptor (TA1) is functional in both rodents and man, and is expressed widely throughout the brain of the mouse, rat and human. The functional role of the TAl receptor in the mammalian brain was therefore the focus of the current project. In order to investigate the function of the TAl receptor, two specific TAl receptor agonists were used, kindly provided by Hoffman La Roche. As the TAl receptor has been implicated in the neuropathophysiology of several psychiatric disorders, such as ADHD and schizophrenia, which are characterised by substantial and debilitating deficits in cognitive performance, initial experiments aimed to assess for any effect of the TAl agonists on cognitive performance in laboratory rodents. In part, the association between the TAl receptor and mental disorders is based on evidence suggesting an interaction with monoamine neurotransmission. However, previously reported findings from in vitro studies do not support a mechanism of interaction comparable with results from in vivo studies. Therefore later experiments investigated the relationship between TAl and monoamine neurotransmission in vivo. Initial experiments focused on the interaction between TAl activation and behaviours induced by psychostimulants known to alter monoamine function, and subsequent investigation examined the possible mechanisms involved using in vivo microdialysis.
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Steffen-Munsberg, Fabian [Verfasser]. "Structure– and sequence–function relationships in (S)-amine transaminases and related enzymes / Fabian Steffen-Munsberg." Greifswald : Universitätsbibliothek Greifswald, 2015. http://d-nb.info/1074259610/34.
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Nealon, Gareth L. "Substituted cage amines : towards new functional metalloassemblies." University of Western Australia. School of Biomedical and Chemical Sciences, 2007. http://theses.library.uwa.edu.au/adt-WU2007.0215.
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Menegol, Tania. "Oxidation of cassava starch with ozone and hydrogen peroxide: effect on some functional properties." Universidade Tecnológica Federal do Paraná, 2013. http://repositorio.utfpr.edu.br/jspui/handle/1/1139.
Повний текст джерелаАнотація:
CapesINTRODUCTION AND OBJECTIVES: Modified starches are obtained by the treatment of starch suspensions with an oxidizing agent to convert hydroxyl groups to carbonyl groups and carboxyl groups, providing starch with interesting properties in the field of food manufacturing, such as neutral taste, adhesion to surfaces, low viscosity binding, transparency gels and low tendency to retrogradation. Different oxidizing treatments have been applied to obtain cassava starch with good expansion properties. In the present study, the changes that occurred in cassava starch subjected to ozone/hydrogen peroxide and the effect of oxidation on the functional properties and expansion of modified starch with the objective of get through this treatment, starches free of metal waste and with favorable expansion properties, clarity and low viscosity are of particular interest in food applications. METHODS: To study the effect of the independent variables, i.e. ozone dosage (1, 3 and 5 g) and hydrogen peroxide content (0.25, 0.5 and 0.75%), on the amylose content, specific volume of biscuits, sum of carbonyl and carboxyl groups, paste viscosity nd intrinsic viscosity, we used the method of experimental research following a 22 composite rotational design with four axial testing conditions, four factorial trials and two repetitions at the central point, for a total of eleven randomized trials. MAIN RESULTS: The modified starches showed different properties compared to the native starch, as evidenced mainly by greater reducing power and swelling. Chemical oxidation was evidenced by an increase in the carbonyl content, as well as reduced solubility and intrinsic viscosity of amylose. DISCUSSION AND CONCLUSION: The observed differences in the physicochemical properties of native starch and modified starches using experimental research design were attributed to the differences are more specific material evaluated in this experiment, since oxidation occurred mainly in amorphous starch granules. The comparative analysis between the modified starches and native starch showed that chemical oxidation increased the content of carbonyl and carboxyl groups, increased solubility and reduced the intrinsic viscosity of amylose and decreased swelling. However, the paste viscosity and the gelation temperature were higher in the oxidized starches compared to the native starch. This was evidenced by the expansion property increase nd the specific volume of biscuits when compared to the standard. Response surface analysis showed that the combination of ozone and hydrogen peroxide had an antagonistic effect and only ozone influenced the functional properties of starch.
INTRODUÇÃO E OBJETIVOS: Os amidos oxidados são obtidos através do tratamento de suspensões de amidos com um agente oxidante, que transformam seus grupos hidroxilas em grupos carbonilas e carboxilas, conferindo-lhes propriedades de interesse na área de industrialização de alimentos, tais como sabor neutro, aderência a superfícies, baixa viscosidade de pasta, géis transparentes e baixa tendência a retrogradar. Diferentes tratamentos oxidantes têm sido aplicados para a obtenção de amido de mandioca com propriedade de expansão. No presente estudo discute-se a modificação ocorrida no amido de mandioca submetido ao par ozônio/peróxido de hidrogênio e o efeito da oxidação nas propriedades funcionais e de expansão do amido modificado, com o objetivo de obter através desse tratamento, amidos isentos de resíduos metálicos e com propriedade de expansão, claridade de pasta e baixa viscosidade, de interesse em aplicações alimentícias específicas. MÉTODOS: Para estudar o efeito das variáveis independentes, dosagem de ozônio (1, 3 e 5g) e teor de peróxido de hidrogênio (0,25, 0,5 e 0,75%) sobre propriedade de pasta, claridade de pasta, teor de amilose, volume específico dos biscoitos, somatório de carbonila e carboxila, poder de inchamento e solubilidade e viscosidade intrínseca usou-se o método de pesquisa experimental, seguindo delineamento composto rotacional 22, com 4 ensaios nas condições axiais, 4 ensaios fatoriais e 2 repetições no ponto central, no total de 11 ensaios distribuídos aleatoriamente. PRINCIPAIS RESULTADOS: Os amidos modificados obtidos apresentaram diferentes propriedades em relação ao amido nativo, evidenciadas, principalmente, pela maior poder redutor e inchamento. A oxidação química foi evidenciada pelo aumento do teor carbonilas, solubilidade e redução na viscosidade intrínseca e no teor de amilose. DISCUSSÃO E CONCLUSÃO: As diferenças observadas nas propriedades físico-químicas do amido nativo e dos amidos oxidados conforme delineamentos da pesquisa experimental são atribuídos às diferenças mais específicas do material avaliado no experimento, visto que a oxidação ocorreu principalmente na região amorfa do grânulo de amido. Na análise comparativa entre os ensaios e o amido nativo, observou-se a oxidação química pelo aumento no teor de carbonilas e carboxilas, de solubilidade e de redução da viscosidade intrínseca e amilose, e diminuição do inchaço. No entanto, a viscosidade de pasta e a temperatura de gelatinização foram maiores nos amidos oxidados em comparação com amido nativo. Evidenciou-se a propriedade de expansão pelo aumento no volume específico (16,03mLg-1) dos biscoitos quando comparada ao padrão. A análise de superfície de resposta indica que a combinação de ozônio e peróxido de hidrogênio tem efeito antagônico e que somente o ozônio influencia nas propriedades funcionais do amido.
5000-12
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Mouselmani, Rim. "Reduction of Organic Functional Groups Using Hypophosphites." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSE1241/document.
Повний текст джерелаАнотація:
Récemment, les exigences en chimie ont évolué rapidement, car le développement durable a retenu plus d'attention. Les principes de la chimie verte ont encouragé les chimistes à développer des produits chimiques et des procédés qui réduisent ou éliminent les substances dangereuses. Les travaux de recherche décrits dans cette thèse portent sur le développement de nouveaux systèmes réducteurs en utilisant des hypophosphites comme substituts aux agents réducteurs toxiques traditionnels.Pour atteindre cet objectif, les nitriles aromatiques ont été réduits en aldéhydes correspondants par la formation du gaz de l’hydrogène et de nanoparticules de nickel en combinant un précurseur de nickel avec de l'hypophosphite de calcium en présence d'une base dans un milieu biphasique. De plus, les nitriles aromatiques ont été réduits en amines primaires en utilisant de l'hypophosphite de calcium et le catalyseur hétérogène palladium sur le carbone. La nature du catalyseur métallique, les additifs, les solvants, la température et les concentrations ont été étudiés en détail.D'autre part, l'amination réductrice directe des cétones aliphatiques et aromatiques a été réalisée pour la première fois en utilisant du palladium hétérogène sur du carbone et de l'hypophosphite d'ammonium qui agit comme une source d'ammoniac et un agent réducteur en même temps. Au cours de l'optimisation, des différents paramètres ont été étudiésRecently, requirements in chemistry are changing fast, since sustainable development has retained more attention. Green chemistry principles have promoted chemists to develop chemical products and processes that reduce or eliminate hazardous substances. The research work described in this thesis is focused on the development of new reducing systems using hypophosphites as substitutes for traditional toxic reducing agents.In order to achieve this goal, aromatic nitriles were reduced into the corresponding aldehydes by the formation of hydrogen gas and nickel nanoparticles upon combining a nickel precursor with calcium hypophosphite in the presence of base in a biphasic medium. Moreover, aromatic nitriles were reduced into primary amines using calcium hypophosphite and the heterogeneous catalyst palladium on carbon. The nature of the metal catalyst, additives, solvents, temperature, and concentrations were studied in details.On the other hand, the well-known direct reductive amination of aliphatic and aromatic ketones was done for the first time using heterogeneous palladium on carbon, and ammonium hypophosphite which acts as a source of ammonia and as a reducing agent at the same time. During optimization different parameters were studied
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梁偉賢 and Wai-yin David Leung. "Synthesis and physical properties of fatty acid derivatives containingamino, amido functions and L-amino acid residues." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1993. http://hub.hku.hk/bib/B31233752.
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Rolph, Marianne S. "The development of amine-functionalised polymeric stars as dual-functional catalysts for polyurethane foam." Thesis, University of Warwick, 2016. http://wrap.warwick.ac.uk/90863/.
Повний текст джерелаАнотація:
This Thesis explores the synthesis of amine-functionalised polymeric stars synthesised using Reversible Addition-Fragmentation Chain Transfer (RAFT) polymerisation, and their applicability as dual functional catalysts for both the catalysis of polyurethane foam production, and for the deblocking of blocked isocyanates. Chapter 1 introduces polyurethane chemistry, and provides an in-depth summary of blocked isocyanates. Additionally, it introduces the RAFT polymerisation chemistry utilised for catalyst synthesis within this thesis. Chapter 2 investigates the use of RAFT polymerisation for the production of non-responsive crosslinked methacrylate polymeric stars. Evaluation of polymeric stars with different structural properties in the polyurethane foam formulation was carried out to assess the protection afforded to the catalytic amine when tethered within the star polymer. Chapter 3 utilises the RAFT synthesis of analogous acrylate based polymeric stars, the hydrolytic susceptibility of which is able to act as a model to those introduced in Chapter 2. Evaluation of the hydrolytic behaviour allowed for further probing of the effect of structural parameters on the protection of the amine. Chapter 4 describes the incorporation of responsive crosslinkers to produce stimuli responsive polymeric stars, including the incorporation of a furan-maleimide thermoresponsive crosslinker utilising Diels-Alder chemistry, in addition to a disulphide based crosslinker which is redox responsive. Chapter 5 explores the incorporation of a diisocyanate based crosslinker with a view towards the production of thermoresponsive polymeric stars using blocked isocyanate chemistries, and therefore minimising the addition of contaminants (e.g. other crosslinkers) to the polyurethane formulation. Chapter 6 discusses the determination of the deblocking temperature of isocyanates in order to understand any trends in the deblocking of both externally and internally blocked isocyanates, as well probing the effect of amines on the deblocking temperature. In the final Chapter, a summary of the work reported in Chapters 2- 6 is provided, with an outlook towards further applications of the polymeric stars reported in this thesis.
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Almeida, Elisândra Costa. "Amido modificado de taro (Colocasia esculenta L. Schott): propriedades funcionais." Universidade Federal da Paraíba, 2012. http://tede.biblioteca.ufpb.br:8080/handle/tede/4029.
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Previous issue date: 2012-04-20Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
Taro has economic and industrial potential to justify investment in this culture because it is a food with excellent nutritional quality, especially starch, important source of energy, frequently used in the food industry, particularly as gelling and thickening agent, applied in the development of several products. However the starch in its native form has limitations for use, requiring modifications to improve its functional properties and increasing its possibilities for use in the food industry. The objective of this research was to study and compare the properties of native starch extract from taro (Colocasia esculenta L. Schott) clone Macaquinho with its modified starch by oxidation, acid hydrolysis, succinylation, intercross and combination of hydrolysis, succinylation and intercross for use in the food industry. After extraction of the starch, it was modified by oxidation using sodium hypochlorite, hydrolysis with hydrochloric acid, succinylation with succinic anhydride and intercrossing with trimetaphosphate and sodium tripolyphosphate. According to the experiments, it was verified that the native starch extracted from Macaquinho clone contains considerable percentage of starch, low amount of substances contaminants, like proteins or lipids, without influences on the functional properties. After the modifications and combinations occurred in the native starch, they did not showed degree of substitution beyond that permitted by regulatory agencies, being in accordance with Brazilian law. The addition of the substituent groups was decisive in the characterization of the functional properties of taro starch, modified and combined. Microscopy revealed that the starch granules presented circular and polyhedral shapes. The hydrolyzed, succinylated and intercrossed starches suffered major visible alterations in their morphology due to the modifications conducted. The swelling of the granules occurred above 75oC, with prominence for the native, oxidized, succinylated and intercrossed starches, which had their swelling power increased with the increase of temperature. The highest solubility was observed in hydrolyzed starches. The higher water absorption capacity was verified in intercrossed starch and the hydrolyzed starches demonstrated higher oil absorption and paste clarity. The best paste properties were obtained to the oxidized starch, followed by native and succinylated starches, with maximum viscosity at low temperatures. However, the oxidized starch showed higher retrogradation tendency, differently from hydrolyzed starches, more stables. The functional profiles noted in native, modified and combined starches of taro were variables, which provide a lot of possibilities for their use in the food industry.
O taro apresenta potencialidades econômicas e industriais que justificam investimentos nesta cultura, pois se trata de um alimento com excelente qualidade nutricional, especialmente em amido, importante fonte energética, muito utilizado na indústria de alimentos, especialmente como agente espessante e gelificante, aplicado no desenvolvimento de inúmeros produtos. Porém o amido na sua forma nativa apresenta limitações de uso, sendo necessária sua modificação, visando a melhoria das suas propriedades funcionais e aumentando as possibilidades de utilização na indústria alimentícia. O objetivo desta pesquisa foi estudar e comparar as propriedades do amido nativo de taro (Colocasia esculenta L. Schott) clone Macaquinho com o seu amido modificado por oxidação, hidrólise ácida, succinilação, intercruzamento, e por combinação da hidrólise com succinilação e intercruzamento para utilização na indústria alimentícia. Após a extração do amido, este foi modificado por oxidação utilizando o hipoclorito de sódio, hidrólise com ácido clorídrico, succinilação com anidrido succínico e intercruzamento com trimetafosfato e tripolifosfato de sódio. Com base nos experimentos realizados constatou-se que o extrato amiláceo nativo do clone Macaquinho contém considerável percentual de amido, com baixo teor de substâncias consideradas contaminantes, não influenciando nas suas propriedades funcionais. Após as modificações e combinações conduzidas no amido nativo, os mesmos não apresentaram grau de substituição além do permitido pelos órgãos reguladores, estando em conformidade com a legislação brasileira. A inclusão dos grupos substituintes foi determinante na caracterização das propriedades funcionais do amido de taro, modificados e combinados. A microscopia revelou que os amidos apresentavam grânulos com formatos circulares e poliédricos. Os amidos hidrolisados, succinilados e intercruzados, sofreram maiores alterações visíveis em sua morfologia, devido às modificações conduzidas. O intumescimento dos grânulos ocorreu acima de 75ºC, com destaque para os amidos nativo, oxidado, succinilado e intercruzado, que tiveram seu poder de inchamento aumentado com a elevação da temperatura. Os maiores perfis de solubilidade foram constatados nos amidos hidrolisados. A maior capacidade de absorção de água foi observada nos amidos intercruzados e a absorção de óleo foi mais evidenciada nos amidos hidrolisados, que também apresentaram maior claridade da pasta. As melhores propriedades de pasta foram obtidas no amido oxidado, seguido dos amidos nativo e succinilado, com viscosidades máximas em temperaturas mais baixas. Porém o amido oxidado apresentou maior tendência à retrogradação, diferentemente dos amidos hidrolisados com pastas mais estáveis. Os perfis funcionais constatados nos amidos nativo, modificados e combinados de taro foram variáveis, o que propicia uma série de possibilidades para a sua utilização na indústria alimentícia.
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Scipioni, Gustavo Callegari. "OTIMIZAÇÃO DO PROCESSO DE SACARIFICAÇÃO DO AMIDO DE BATATA (Solanum Tuberosaum L.) UTILIZANDO ENZIMAS AMILOLÍTICAS." Universidade Federal de Santa Maria, 2011. http://repositorio.ufsm.br/handle/1/7954.
Повний текст джерелаАнотація:
Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorThe potato (Solanum tuberosum) is important raw material for agro-industrial production of hydrolysates. The lack of information about the process of hydrolysis of potato starch industry hampers the use of regional raw material and promote the use of crops such as maize, cassava and sugarcane to produce ethanol. The objective of this study was to determine the optimum range of the effects of different concentrations of substrate, concentration of enzyme amyloglucosidase (AMG) and reaction times, reduce process time, enzymes and material to be hydrolyzed. This was a central composite experimental design with three independent variables namely: [1] substrate concentration (3-7%) [2] enzyme dosage (0.36 to 1.0 μL.g MS-1) [ 3] time of action of enzymes computed after the addition of AMG in the middle (4 to 48 hours). The α-amylase concentration remained constant at 0.8 μL/g starch. The experiments were conducted in the bioreactor followed by metabolic bath. The dependent variables analyzed were the concentration of reducing sugars (RS) and the efficiency of hydrolysis of starch. The data were processed by Statistica 8.0, to generate predictive models at 95% confidence. The larger fraction of RA was reached in the middle (35.55 g/L), with time (26 hours) and dose of enzyme (0.68 mL) and substrate concentration at the maximum level (7%). The efficiency of hydrolysis (125%) occurred with the minimum ratio of substrate (3%) and enzyme dosage (0.68 mL) and the average time (26 hours). To reduce costs of enzyme (0.36 mL AMG), working with the same concentration of substrate, the model estimated that the hydrolysis for 39 hours was able to release 33.17 g/L of the AR 128, 62% efficiency. The use of different enzyme concentrations showed no significant increase in responses, and the time factor is set lower than recommended by the manufacturer of the enzymes. The concentration of substrate influenced more significantly than other factors, for both dependent variables. The performance presented demonstrates that this process is an efficient alternative to the industry, emerging as an important source this material for the production of hydrolysates.
A batata (Solanum tuberosum) é importante matéria-prima agroindustrial para produção de hidrolisados. A falta de informações sobre o processo de hidrólise do amido de batata na indústria dificulta a utilização desta matéria-prima regional e favorece o uso das culturas como: milho, mandioca e cana de açúcar para produção de álcool etílico. O objetivo deste trabalho foi apurar a faixa otimizada dos efeitos de diferentes concentrações de substrato, concentração de enzima amiloglicosidase (AMG) e períodos reacionais, na redução de tempo do processo, enzimas e material a ser hidrolisado. Foi realizado um desenho experimental central composto, com três variáveis independentes sendo elas: [1] concentração de substrato (3-7%), [2] dosagem enzimática (0,36-1,0μL/g de MS), [3] tempo de ação das enzimas computado após a adição da AMG no meio (4 a 48 horas). A concentração de α-amilase manteve-se constante em 0,8μL/g de amido. Os experimentos foram conduzidos em bioreator seguido de banho metabólico. As variáveis dependentes analisadas foram a concentração de açúcares redutores (AR) e a eficiência de hidrólise do amido. Os dados foram tratados pelo Statistica 8.0, para gerar modelos preditivos a 95% de confiança. O teor maior de AR foi alcançado no meio (35,55g/L), com tempo (26 horas) e dosagem de enzima (0,68μL) e concentração de substrato no nível máximo (7%). A maior eficiência de hidrólise (125%) ocorreu com a razão mínima de substrato (3%) e dosagem de enzimas (0,68μL) e tempo no nível médio (26 horas). Para a redução dos custos com enzima (0,36μL/g MS de AMG), trabalhando-se com a mesma concentração de substrato, o modelo estimou que a hidrólise por 39 horas era capaz de liberar 33,17 g/L de AR , com 128,62% de eficiência. O uso de diferentes concentrações de enzimas não apresentou incremento significativo nas respostas, sendo que o fator tempo se estabeleceu abaixo do recomendado pelo fabricante das enzimas. A concentração de substrato influenciou de forma mais significativa que os demais fatores, para ambas variáveis dependentes. O rendimento apresentado demonstra que este processo é uma alternativa eficiente à indústria, despontando este material como fonte importante para produção de hidrolisados.
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Leung, Wai-yin David. "Synthesis and physical properties of fatty acid derivatives containing amino, amido functions and L-amino acid residues /." [Hong Kong : University of Hong Kong], 1993. http://sunzi.lib.hku.hk/hkuto/record.jsp?B13637666.
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Sun, Ying. "A Multi-Method Approach for the Quantification of Surface Amine Groups on Silica Nanoparticles." Thesis, Université d'Ottawa / University of Ottawa, 2019. http://hdl.handle.net/10393/39480.
Повний текст джерелаАнотація:
As nanomaterials continue to garner interest in a wide range of industries and
scientific fields, commercial suppliers have met growing consumer demand by readily
offering custom particles with size, shape and surface functionality made-to-order. By
circumventing the challenging and complex synthesis of functionalized nanoparticles,
these businesses seek to provide greater access for the experimentation and
application of these nanoscale platforms.
In many cases, amine functional groups are covalently attached as a surface
coating on a nanoparticle to provide a starting point for chemical derivatization and
commonly, conjugation of biomolecules in medical science applications. Successful
conjugation can improve the compatibility, interfacing and activity of therapeutic and
diagnostic nanomedicines. Amines are amongst the most popular reactive groups used
in bioconjugation pathways owing to the many high-yield alkylation and acylation
reaction are involved in.
For the design of functionalized nanomaterials with precisely tuned surface
chemical properties, it is important to develop techniques and methods which can
accurately and reproducibly characterize these materials. Quantification of surface
functional groups is crucial, as these groups not only allow for conjugation of chemical
species, but they also influence the surface charge and therefore aggregation behavior
of nanomaterials. The loss of colloidal stability of functionalized nanomaterials can often
correspond to a significant if not complete loss of functionality.
Thus, we sought to develop multiple characterization approaches for the
quantification of surface amine groups. Silica nanoparticles were selected as a model
nanomaterial as they are widely used, commercially available, and their surface
chemistry has been investigated and studied for decades. Various commercial batches
of silica nanoparticles were procured with sizes ranging from 20 – 120 nm. Two
colorimetric assays were developed and adapted for their ease-of-use, sensitivity, and
convenience. In addition, a fluorine labelling technique was developed which enabled
analysis by quantitative solid-state 19F NMR and X-ray photoelectron spectroscopy
(XPS). XPS provided data on surface chemical composition at a depth of ≈ 10 nm,
which allowed us to determine coupling efficiencies of the fluorine labelling technique
and evaluate the reactivity of the two assays.
The ensemble of surface-specific quantification techniques was used to evaluate
multiple commercial batches of aminated silica and investigate batch-to-batch variability
and the influence of particle size with degree of functionalization. In addition, resulting
measurements of surface amine content were compared and validated by an
independent method based on quantitative solution 1H NMR, which was developed for
total functional group content determination. This allowed for us to assess the role of
accessibility and reactivity of the amine groups present in our silica particles.
Overall, the objective of this study was to develop a multi-method approach for
the quantification of amine functional groups on silica nanoparticles. At the same time,
we hoped to set a precedent for the development and application of multiple
characterization techniques with an emphasis of comparing them on the basis of
reproducibility, sensitivity, and mutual validation.
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Matsuda, Luciana Yumi. "Concentração de amido resistente em pão francês pré-assado congelado: aspectos tecnológicos." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/3/3137/tde-02062008-155730/.
Повний текст джерелаАнотація:
O objetivo deste trabalho foi estudar a substituição parcial da farinha de trigo (FT) por amido resistente de milho (ARM) na elaboração de pão francês pré-assado congelado (PFPAC) e oferecer uma alternativa tecnológica para um produto consumido no desjejum dos brasileiros, com propriedades funcionais devido ao conteúdo de fibra alimentar (FA). Medidas de desempenho de misturas com quatro níveis (0%, 5%, 15% e 30%) de substituição de FT por ARM, sendo 100% o equivalente ao total da mistura, foram obtidas através de alveografia e reofermentografia. Avaliação tecnológica e concentração de amido resistente (AR) de PFPAC produzidos a partir de misturas com cinco níveis de substituição de FT por ARM (0,0%, 7,5%, 10,0%, 12,5% e 15,0%), foram realizadas de acordo com os resultados obtidos nas misturas. A análise foi conduzida ao longo do armazenamento congelado até 46 dias em cinco pontos (1, 8, 15, 25 e 46 dias). O nível de substituição influenciou significativamente o volume específico, a textura do miolo dos pães e a [AR], enquanto que o tempo de armazenamento influenciou a textura do miolo dos pães e a [AR]. O PFPAC produzido a partir da mistura com 10,0% de substituição de FT por ARM apresentou características tecnológicas similares à formulação padrão (0% de substituição) e concentração de 5,5 g de AR por 100 g de produto, sendo considerado, de acordo com a legislação brasileira, um alimento fonte de fibras. Medidas da [AR] nas diferentes etapas do processo produtivo de PFPAC (formulação, pré-assado congelado e pré-assado forneado) indicaram que a [AR] aumentou proporcionalmente em relação ao nível de substituição e redução com a evolução do tempo de armazenamento congelado, apresentando ótimo ajuste (r2 de 0,949) para o modelo quadrático.The objective of this work was to study the partial substitution of wheat flour (WF) for maize resistant starch (MRS) in the elaboration of frozen par-baked French bread (FPBFB) and offering a technological alternative for a product consumed at Brazilians\' breakfast, presenting functional properties due to dietary fiber (DF) content. Dough performance measurements of mixtures at four levels (0%, 5%, 15% and 30%) of substitution of WF for MRS, being 100% equal to the mixture total, were obtained through alveography and rheofermentography. Technological evaluation and resistant starch (RS) concentration of FPBFB produced from mixtures with five substitution levels of WF for MRS (0.0%, 7.5%, 10.0%, 12.5% and 15.0%), were carried out according to the results obtained in the mixtures. The evaluation was conducted throughout 46 days of frozen storage, in five points (1, 8, 15, 25 and 46 days). Substitution level influenced significantly the specific volume, crumb texture and RS concentration of breads, whereas the frozen storage time influenced the bread crumb texture and RS concentration. The FPBFB produced from the mixture with 10% substitution of WF for MRS presented similar technological characteristics to the standard formulation (0% substitution) and RS concentration of 5.5 g per 100 g of product, being considered, according to Brazilian Legislation, a fiber-source foodstuff. Measures of RS concentration conducted in different bread production steps (formulation, frozen par-baked bread and par-baked bread fully baked), indicated that the RS concentration increased proportionally to the substitution level and reduced as the frozen storage time increased, presenting good adjustment (r2 of 0.949) to the quadratic model.
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Schmalen, Angela [Verfasser]. "Post polymerization modification of poly(vinyl amine) with functional epoxides : multifunctional, antimicrobial, protein-like polymers / Angela Schmalen." Aachen : Hochschulbibliothek der Rheinisch-Westfälischen Technischen Hochschule Aachen, 2015. http://d-nb.info/1066984344/34.
Повний текст джерела
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Lorenza, Bellusci. "Biochemical and functional effects of trace amine-associated receptor 1 (TAAR1) agonists in the central nervous system." Doctoral thesis, Università di Siena, 2019. http://hdl.handle.net/11365/1071151.
Повний текст джерелаАнотація:
3-iodothyronamine (T1AM) is an endogenous high-affinity ligand for the trace amine-associated receptor 1 (TAAR1) found circulating in mammals and accumulating in many tissues including the brain. Its functional effects are now known to include decrease in heart rate, cardiac output, body temperature, and metabolic rate, as well as stimulation of lipid vs carbohydrate catabolism and neurological effects, including prolearning and antiamnestic action, reduced pain threshold, and reduction of non-REM sleep. The close structural similarity with thyroid hormone (TH) induced to speculate that T1AM might be synthetized from TH through decarboxylation and deiodination, but this hypothesis still requires validation. Notably, in addition to the structural similarities between T1AM and TH, T1AM contains the same arylethylamine scaffold also found in monoamine neurotransmitters, implicating an intriguing role for T1AM as both a neuromodulator and a hormone-like molecule constituting a part of thyroid hormone action. Recent evidence indicates that targeting TAAR1 may provide a new therapeutic approach for the treatment of a range of neuropsychiatric and metabolic disorders. Consistently, T1AM and recently developed halogen free biaryl-methane thyronamine-like TAAR1 agonists, SG-1 and SG-2, have emerged as rapid modulators of behavior and metabolism, with SG-2 showing a potency almost comparable to that of T1AM.
To assess the therapeutic potential of TAAR1 agonists for neuroprotection, in the present thesis we investigated whether T1AM and its corresponding halogen free synthetic analogue SG-2 improve learning and memory when systemically administered to mice at submicromolar doses. In addition, since autophagy is key for neuronal plasticity, T1AM and newly developed thyronamine-like TAAR1 agonists SG-1 and SG-2 were evaluated as autophagy inducers in cell lines.
T1AM is known to induce pro-learning and anti-amnestic responses when administered icv at very low doses (1.32 to 4 μg.kg-1) to mice, but its effects on memory after systemic administration are currently unknown. To address this point, we evaluated the behavior of CD-1 mice injected i.p. with T1AM or SG-2 (1.32, 4 and 11 μg.kg-1), in the passive avoidance test, while measuring in specific brain areas the activation of typical signalling proteins involved in memory acquisition, including pERK and transcription factor c-fos. The passive avoidance test showed that when
administered i.p. at 11 μg.kg-1 either T1AM or SG-2 induced significant memory enhancement. T1AM also significantly increased retention when administered at a lower dosage (4 μg.kg-1). Memory acquisition and storage are typically associated with increased ERK1/2 phosphorylation. After treatment with T1AM and SG-2 at doses of 1.32 μg·kg-1, pERK could be detected, but its levels were not significantly different from those found in vehicle injected mice. However, after treatment with T1AM and SG-2 at doses that proved to be effective on memory acquisition and retention (i.e. 4 and 11 μg·kg-1) pERK turned out to be significantly higher (p<0.01) than that observed in the vehicle group. Similar to pERK, c-fos was not significantly changed in any brain area by treatment with 1.32 μg·kg-1 of T1AM or SG-2. For both compounds, only when injected at the highest dose (i.e. 11μg·kg-1) moderate changes of c-fos expression were observed. At the dosages active on memory, T1AM and SG-2 also proved to have an hyperalgesic effect. In addition, our pain threshold experiments revealed that TA1 and SG-6, the oxidative metabolites of T1AM and SG-2, respectively, seem to play a critical role for the action of the corresponding amine. In fact, at our settings, pretreatment with clorgyline abolished almost completely the effect on pain of T1AM or SG-2 administered i.p. at the highest dosage (i.e., 11 μg/kg). The same effect was also shown to involve the histaminergic system, as it disappeared after pretreatment with the histamine H1-receptor antagonist, pyrilamine. Preliminary results from a LC/MS-MS pharmacokinetic study of TA1 bio-distribution after sistemic administration, indicated that there is a difference in the capacity of clearing the acid by different tissues, with the brain conserving TA1 levels for longer than plasma or liver. Therefore, the brain might represent one important target for TA1 action.
Autophagy (ATG) is one of the most important mechanisms of neuroprotection. Inducing autophagy may represent a reasonable strategy to develop therapeutics for the treatment of neurodegenerative diseases, including Alzheimer's disease. Therefore, to explore the possible link between TAAR1 activation and neuroprotection, we investigated the ability of T1AM, SG-1 and SG-2 to induce autophagy in human glioblastoma cell lines (U-87MG) by examining the formation of autophagosomes and autophagic flux. During the process of autophagy, LC3I is converted to its lipidated form LC3II, which is one of the hallmarks of autophagy and essential for the formation of autophagosome. P62 is used as a marker of autophagic
flux and inversely correlates with autophagic activity. It binds directly to LC3 and degrades during autophagy. In cultured U-87MG cells exposed to 1μM T1AM, SG-1, SG-2 (for 0.5, 4, 8 and 24h) transmission electron microscopy (TEM) and immunofluorescence (IF) showed a significant (p<0.01) time-dependent increase of autophagy vacuoles and microtubule-associated protein 1 light chain 3 (LC3), with T1AM and SG-1 being the most effective agents. Consistently, western blotting results showed that test compounds increased the conversion of LC3-I to LC3-II while decreasing the levels of P62 in an obvious time-dependent manner. We then proceeded to elucidate which pathway was involved in ATG induction by assessing the effect of our test compounds on the PI3K–AKT–mTOR pathway. We found that 1μM T1AM, SG-1 and SG-2 decreased pAKT/AKT ratio at 0.5 and 4h after treatment (p<0.01), suggesting that these compounds induce autophagy through a reduction of pAkt level.
Taking into account the key role played by ATG and/or Ubiquitine-proteasome (UP) in all clearing pathways modulating cell survival and disease mechanisms, and considering their involvement in a wide range of disorders, including neurodegenerative diseases (NDDs), we were also able to prove the ability of T1AM, SG-1 and SG2 to modulate the UP system. Indeed, our TEM analysis showed increased 20S proteasome recruitment to autophagosome in U-87MG cells after treatment with 1μM T1AM, SG-1 and SG-2, suggesting that these compounds might modulate both ATG and UP protein clearing pathways within the autophagoproteasomes.
A growing body of evidence has suggested the presence of a strong correlation between obesity and neurodegeneration. NDDs, such as Alzheimer Disease (AD) and Parkinson Disease (PD), are characterized by a progressive loss of memory and cognition, which can ultimately lead to death. This deterioration is majorly a result of inflammation due to aberrant protein deposition, oxidative stress and modification in lipid pathways. Recent studies demonstrated acute and chronic T1AM treatment to have potent effects on shifting whole body macro-nutrient metabolism in mammals. On the basis of these findings, we decided to explore whether T1AM, SG-2 and recently designed synthetic thyronamine/thyroid hormone-hybrid analogs IS25 and TG46 could promote lipolysis in HepG2 cells. Oil Red O staining of HepG2 revealed that all test compounds reduced total lipid accumulation into lipid droplets compared
to the control. Moreover, the analysis of free glycerol release confirmed that decreased accumulation of lipids in HepG2 cells observed after Oil Red O staining was caused by increased lipolysis. The involvement of AMPK/ACC modulation was also confirmed by western blot analysis that showed an enhancement of both pAMPK/AMPK and pACC/ACC ratios. AMPK stimulation by test compounds led indeed to the phosphorylation and consequent inactivation of acetyl coenzyme A carboxylase (ACC), the major regulator of fatty acids synthesis.
In conclusion, taken together our data displayed that T1AM and thyronamine-like compounds SG-1 and SG-2 have neuroprotective properties, which also involve the induction of autophagy and the regulation of Ubiquitine-Proteasome System. Indirectly, together with newly designed thyronamine/thyroid hormone- hybrid analogs, they could exert a protective action through lipolytic effects. This novel aspect requires further investigation.
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Blenau, Wolfgang, Lore Grohmann, Joachim Erber, Paul R. Ebert, Timo Strünker, and Arnd Baumann. "Molecular and functional characterization of an octopamine receptor from honeybee (Apis mellifera) brain." Universität Potsdam, 2003. http://opus.kobv.de/ubp/texte_eingeschraenkt_verlag/2010/4429/.
Повний текст джерелаАнотація:
Biogenic amines and their receptors regulate and modulate many physiological and behavioural processes in animals. In vertebrates, octopamine is only found in trace amounts and its function as a true neurotransmitter is unclear. In protostomes, however, octopamine can act as neurotransmitter, neuromodulator and neurohormone. In the honeybee, octopamine acts as a neuromodulator and is involved in learning and memory formation. The identification of potential octopamine receptors is decisive for an understanding of the cellular pathways involved in mediating the effects of octopamine. Here we report the cloning and functional characterization of the first octopamine receptor from the honeybee, Apis mellifera . The gene was isolated from a brain-specific cDNA library. It encodes a protein most closely related to octopamine receptors from Drosophila melanogaster and Lymnea stagnalis . Signalling properties of the cloned receptor were studied in transiently transfected human embryonic kidney (HEK) 293 cells. Nanomolar to micromolar concentrations of octopamine induced oscillatory increases in the intracellular Ca2+ concentration. In contrast to octopamine, tyramine only elicited Ca2+ responses at micromolar concentrations. The gene is abundantly expressed in many somata of the honeybee brain, suggesting that this octopamine receptor is involved in the processing of sensory inputs, antennal motor outputs and higher-order brain functions.
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Thys, Roberta Cruz Silveira. "Caracterização e avaliação de amido nativo e modificado de pinhão mediante provas funcionais e térmicas." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2009. http://hdl.handle.net/10183/18598.
Повний текст джерелаАнотація:
O pinhão é a semente comestível da Araucaria angustifolia, sendo consumido no sul e sudeste do Brasil principalmente na sua forma in natura. A falta de diversidade em relação ao seu consumo acarreta a sobra da safra e a sua utilização como ração animal, o que diminui o valor de comercialização do produto, prejudicando os ganhos econômicos do produto. A semente do pinhão é composta de 34% de amido e um conteúdo muito baixo de proteínas e lipídios, o que a torna favorável para a obtenção de amido, aditivo amplamente utilizado pela indústria de alimentos. O objetivo deste trabalho foi caracterizar uma nova fonte de amido a partir de semente de Araucária angustifolia, através de um estudo detalhado da metodologia de extração do amido de pinhão, das características físico-químicas, funcionais e reológicas do grânulo e de sua modificação estrutural. Primeiramente foi determinado um protocolo para a extração do amido e realizado o estudo do efeito do tratamento alcalino (NaOH 0,05 mol.l-1 e NaOH 0,1 mol.l-1), em relação ao tratamento com água, na estrutura dos grânulos do amido extraídos. Para tanto foram feitas análises de fluorescência intrínseca, microscopia eletrônica de varredura e de força atômica e difractometria de raios X. A estrutura granular do amido de pinhão foi alterada significativamente quando as soluções alcalinas foram utilizadas durante a extração. O amido de pinhão apresentou estrutura do tipo C. Foram determinadas as características do grânulo de amido nativo, através de análises físico-químicas, MEV, microscopia ótica e sinerese, onde se verificou que o diâmetro médio dos grânulos de amido varia de 7 a 20 μm e as formas geométricas variam entre a oval, a elipsóide truncada e a hemisférica. O amido de pinhão mostrou-se menos propenso à retogradação, comparado ao amido de milho. Foram elaboradas as isotermas de adsorção do amido nativo às temperaturas de 10°, 20°, 30° e 40°C a partir do ajuste dos dados experimentais a diversos modelos de sorção, sendo os modelos de Peleg, seguidos pelos de Chung-Pfost e GAB os que tiveram os maiores coeficientes de correlação. A partir do modelo de GAB foram calculados os valores de umidade de monocamada, entalpia e entropia diferenciais de sorção. Foi realizado também um planejamento experimental a fim de estudar a reação de hidrólise do amido, através da influência das variáveis temperatura (30°a 44°C) e concentração de ácido clorídrico (1,2 a 3,2 mol.l-1) no valor de dextrose equivalente (DE) e na capacidade de formação do gel e de sua termorreversibilidade. Foi observado que sob os maiores valores de temperatura e concentração de ácido empregados, o valor de DE foi maior. No tratamento que resultou no maior valor de DE (3,2 mol.l-1 de HCl e 44°C) foi observada a formação de gel termorreversível, o que indicou a potencialidade do amido modificado como substituto de gordura e agente ligante, em alimentos. A funcionalidade do amido de pinhão foi verificada através das análises de formação, fusão e termorreversibilidade do gel, tendência à retrogradação, estabilidade ao congelamento e descongelamento, poder de inchamento, índice de solubilização, MEV, viscosidade de pasta e propriedades térmicas, como temperatura e entalpia de gelatinização. Os resultados indicaram que: somente os amidos modificados apresentam géis termorreversíveis; os amidos de pinhão nativo e modificados possuem menor tendência à retrogradação do que seus similares de milho; a modificação do amido reduziu a tendência à retrogradação das pastas de amido; o amido de pinhão mostrou menor sinerese sob armazenamento à 5°C e após ciclos de congelamento e descongelamento; a temperatura de armazenamento influi significativamente no poder de inchamento (PI) e no índice de solubilização dos amidos de pinhão e milho nativos; os amidos modificados apresentaram menor PI do que os nativos; a viscosidade máxima do amido de pinhão foi maior à encontrada para o amido de milho, sendo ele menos resistente à agitação mecânica à quente (maior breakdown); a hidrólise ácida reduziu drasticamente a viscosidade das pastas formadas; a temperatura de gelatinização do amido de pinhão é de 47,64°C e a entalpia de gelatinização de 15,23 J.g-1; a hidrólise ácida aumentou a temperatura de gelatinização das espécies testadas.Pinhão is the edible seed of Araucaria angustifolia, being consumed in the south and southeastern Brazil mainly in the natural form. The lack of diversity in relation to its consumption results in plenty of crop and its use as animal feed, which reduces the value of product marketing and affect the economic gains of the product. The pinhão seed is composed of 34% starch and a very low content of proteins and lipids, making it favorable for obtaining starch that is widely used by the food industry. The objective of this study was to characterize a new source of starch from seeds of Araucaria angustifolia, through a detailed study of the method for starch extraction, the physical-chemical, functional and rheological properties of the granules and their structural modification. To do this, a protocol for the starch extraction and a study of the effect of alkaline treatment (NaOH 0.05 mol.l-1 NaOH and 0.1 mol.l-1) compared to water treatment, was first established. Therefore, intrinsic fluorescence analysis, scanning electron and atomic force microscopy and x-ray diffractometry were carried out. The granular structure of pinhão starch was changed significantly when the alkaline solutions were used during extraction. The pinhão starch had a type C structure. The characteristics of native starch granules, through physical and chemical analysis, SEM, optical microscopy and syneresis were determined which found that the average diameter of starch granules varies from 7 to 20 μm and geometric shapes range from oval, the ellipsoid truncated and hemispheric. The pinhão starch was less prone to retrogradation compared to maize starch. The adsorption isotherms of native starch at temperatures of 10 °, 20 °, 30 ° and 40 ° C were drafting from fitting the experimental data to various sorption models. The Peleg model, followed by Chung-Pfost and GAB model had the highest correlation coefficients. From the GAB model were calculated monolayer moisture, enthalpy and entropy differential sorption. It was also carried out an experimental design to study the reaction of starch hydrolysis, through the influence of temperature (30° to 44°C) and hydrochloric acid concentration (1.2 to 3.2 mol.l- 1) on the dextrose equivalent value (DE) and on the ability of the gel formation and its thermoreversibility. It was observed that under the highest values of temperature and concentration of acid, the value of DE was higher. In larger value of DE (3.2 mol l-1 HCl and 44°C) was observed the formation of thermoreversible gel, which indicated the potential of modified starch as a fat substitute and a binder in food. The functionality of the pinhão starch was verified by analyzing the gel formation and fusion, gel thermoreversibility, tendency to retrogradation, stability to freezing and thawing, swelling power, solubility index, SEM, pasting viscosity and thermal properties such as temperature and enthalpy of gelatinization. The results showed that: only the modified starches exhibit thermoreversible gels, the native and modified pinhão starch have less tendency to retrograde than their counterparts in maize, the modification of starch reduced the tendency to retrogradation of starch pastes, the pinhão starch showed lower syneresis under storage at 5°C and after freezing and thawing, storage temperature affects significantly the swelling power (SP) and the solubility index of pinhão and maize native starches, the modified starches had lower SP of the natives, the maximum viscosity of pinhão starch was higher than that found for maize starch, the pinhão starch is less resistant to hot mechanical stirring (greater breakdown) than for maize starch, the acid hydrolysis reduced the viscosity of the pulp formed, the gelatinization temperature of pinhão starch is 47.64°C and its gelatinization enthalpy is 15.23 Jg-1; acid hydrolysis increased the gelatinization temperature of the species tested.
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Sanchez, Diana Buchner de Oliveira. "Desempenho reológico e entálpico da massa de pão com amido resistente de milho e transglutaminase." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/3/3137/tde-11082009-163741/.
Повний текст джерелаАнотація:
O objetivo desse trabalho foi estudar a influência da substituição parcial da farinha de trigo (FT) por amido resistente de milho (ARM) e da adição da enzima transglutaminase (TG) sobre o desempenho reológico e entálpico da massa de pão. O ARM foi adicionado como uma alternativa de aumentar a ingestão de fibra alimentar (FA), enquanto que a TG foi adicionada como forma de suprir a diluição do glúten, catalisando as ligações. Foram realizadas análise de textura da massa (extensão uniaxial, biaxial e Texture Profile Analysis - TPA), análise térmica de calorimetria exploratória diferencial (DSC) e reológica (reofermentógrafo). De acordo com um planejamento experimental estrela com três pontos centrais e quatro axiais as análises foram conduzidas em cinco níveis de substituição da farinha de trigo (FT) pelo amido resistente de milho (ARM): 1,5 %; 3,5 %; 8,5 %; 13,5 %; 15,5 % (base 100 % mistura) e cinco níveis de adição de enzima transglutaminase (TG): 0,03 %; 0,05 %; 0,10 %; 0,15 %; 0,17 %. As mesmas análises foram realizadas em massa produzida com farinha de trigo (controle), sem adição de ARM e TG. A substituição de FT por ARM influenciou mais os parâmetros de textura do que a adição de TG. A resistência à extensão atingiu um valor 32 % maior que o controle com a substituição de 8,5 % de ARM e adição de 0,12 % de TG. Nos ensaios realizados no DSC foram identificados três picos endotérmicos, sendo eles: fusão da água, gelatinização do amido do trigo (60 °C) e gelatinização do ARM (115 °C). A altura máxima de desenvolvimento da massa (Hm), medida no reofermentógrafo, foi influenciada significativamente, diminuindo com o aumento da adição de ARM. A absorção de água aumentou conforme a adição de fibras, porém até 11 % de substituição por ARM pode ser considerado igual ao controle. No intervalo estudado, a TG não contribuiu positivamente no desempenho da massa e, portanto, baseado nos resultados obtidos, a mistura com substituição de FT por ARM até 8,5 % não influenciará significativamente os seus parâmetros reológicos e de textura, podendo ser utilizada para manufatura de pão com maior teor de fibras.The objective of this work was to study the partial substitution of wheat flour (WF) to maize resistant starch (MRS) and the addition of transglutaminase enzyme (TG) on the rheological and enthalpy properties of pan bread dough. The MRS was added as an alternative to increase the fiber ingestion while TG was added to supply the gluten dilution, catalyzing the bonds. Texture analyses (uniaxial extension, biaxial extension and Texture Profile Analysis TPA), thermal analysis on Differential Scanning Calorimetric (DSC) and rheological tests (rheofermentometer) were carried out in pan bread dough produced with five levels of wheat flour substitution from maize resistant starch: 1.5 %; 3.5 %; 8.5 %; 13.5 %; 15.5 % (basis on 100 % of mixture) and five addition levels of transglutaminase (TG): 0.03 %; 0.05 %; 0.10 %; 0.15 %; 0.17 % according to a composite design (2²) with three central and four star points. The same tests were conducted in pan bread dough without added MRS and TG and considered as control. The substitution of WF from MRS has more influenced the textural parameters than the addition of TG. The extension strength achieved a value 32 % higher than control with the substitution of 8.5 % of MRS and 0.12 % of TG. During the DSC tests, it has been found three endothermic peaks: fusion of water, gelatinization of wheat starch (60 °C) and gelatinization of MRS (115 °C). The maximum dough height (Hm), obtained from rheofermentometer curves, was significantly influenced, decreasing with the increase the addition of MRS. The absorption of water increased with the fibers addition, however up to 11 % of substitution of MRS, it could be considered equal to the control. TG did not contribute positively on the dough performance, at studied interval, and therefore mixture with substitution of WF by MRS up to 8.5 % will not significantly influence their rheological and texture parameters and can be used to manufacture pan bread with high fiber content.
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Fellenberg, Christin [Verfasser], Thomas [Akademischer Betreuer] Vogt, Birgit [Akademischer Betreuer] Dräger, and Danièle [Akademischer Betreuer] Werck-Reichhart. "Biosynthesis and function of hydroxycinnamic acid amides in flowers of Arabidopsis thaliana : [kumulative Dissertation] / Christin Fellenberg. Betreuer: Thomas Vogt ; Birgit Dräger ; Danièle Werck-Reichhart." Halle, Saale : Universitäts- und Landesbibliothek Sachsen-Anhalt, 2013. http://d-nb.info/1033672432/34.
Повний текст джерела
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Drieu, la Rochelle Armand. "Etude des interactions fonctionnelles entre récepteurs à peptide RF-amide et caractérisation de ligands bifonctionnels des récepteurs mu opioïde et NPFF." Thesis, Strasbourg, 2018. http://www.theses.fr/2018STRAJ109/document.
Повний текст джерелаАнотація:
Les opiacés demeurent des molécules incontournables dans le traitement des douleurs moyennes à sévères. Si leur efficacité dans le traitement de la douleur aiguë est incontestable, leur utilisation chronique est responsable de nombreux effets indésirables comprenant une hypersensibilité à la douleur et une tolérance à leurs effets analgésiques. Une partie de ces effets secondaires résulteraient de l’activation de systèmes anti-opioïdes endogènes, comme les neuropeptides RF-amide, dont des études précédentes suggèrent une complémentarité de fonctionnement dans la modulation de la douleur. Le premier axe de travail de cette thèse fut de développer les outils moléculaires afin d’étudier la possibilité d’interactions fonctionnelles et d’hétérodimérisation de ces récepteurs, en particulier GPR103 et NPFF1R. Nous avons ainsi pu générer et caractériser des lignées cellulaires exprimant les différents récepteurs à peptide RF-amide avec un fluorophore fusionné à leur extrémité amino-terminale. En parallèle, nous avons pu développer au cours d’une collaboration fructueuse avec deux équipes de chimistes un ligand à dualité d’action, agoniste opioïdergique et antagoniste des récepteurs NPFF1R et NPFF2R. Chez la souris, nous avons montré que l’administration sous-cutanée de ce composé produit une analgésie longue durée, qui n’est pas atténuée par le développement de tolérance analgésique ou d’hyperalgésie après une semaine d’administration quotidienne. Le syndrome de sevrage, précipité par la naltrexone est plus faible après l’administration chronique de ce composé qu’avec l’agoniste opioïdergique de référence. De plus, grâce à ses caractéristiques d’agoniste biaisé sur le récepteur MOR, cette molécule induit une plus faible dépression respiratoire chez la sourisOpioid analgesics continue to be the cornerstones for treating moderate to severe pain. However, upon chronic administration, their efficiency is limited because of prominent side effects, such as tolerance and dependence. One hypothesis for the occurrence of these side effects is that the chronic stimulation of the opioid system may trigger its endogenous counterparts, anti-opioid systems, producing hyperalgesia and analgesic tolerance. Previous data from our lab and others suggest that RF-amide peptide receptors can modulate pain signalling through cross-interactions. We developed cell lines expressing fluorescent RF-amide receptors for the study of functional crosstalk and heterodimerization between RF-amide peptide receptors, i.e. GPR103 and NPFF1R. Through a productive collaboration with two teams of chemists, we identified and characterized multitarget peptidomimetic compounds that combined G protein-biased agonism and NPFFR antagonism. In accordance with in vitro results, we observed that acute subcutaneous administration of this compound produced long-lasting antinociceptive effects with less respiratory depression in mice. No hypersensitivity nor analgesic tolerance developed after chronic administration. Altogether, this molecule showed potent antinociceptive effect with limited side effects upon acute and chronic administration
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Kamisetty, Nagendra Kumar. "Development of advanced DNA microarray system by high density amine functionalization of solid surface and functional design of DNA probes." Kyoto University, 2007. http://hdl.handle.net/2433/135562.
Повний текст джерелаАнотація:
Kyoto University (京都大学)0048
新制・課程博士
博士(エネルギー科学)
甲第12717号
エネ博第145号
新制||エネ||35(附属図書館)
UT51-2007-C253
京都大学大学院エネルギー科学研究科エネルギー社会・環境科学専攻
(主査)教授 牧野 圭祐, 教授 尾形 幸生, 助教授 小瀧 努
学位規則第4条第1項該当
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Morin, Aurélie. "Controlled radical polymerization of vinyl esters and vinyl amides : experimental and theoretical studies." Thesis, Toulouse, INPT, 2013. http://www.theses.fr/2013INPT0117/document.
Повний текст джерелаАнотація:
Ces travaux de thèse portent sur la polymérisation radicalaire contrôlée (PRC) des esters et amides de vinyle. L’une des possibilités de contrôle est le piégeage dynamique réversible des chaînes radicalaires croissantes (P•) par un agent de contrôle (T) formant une espèce dormante (P─T’). La concentration en radicaux dans le milieu peut alors diminuer dramatiquement de sorte que les réactions indésirables de terminaisons soient négligeables et que le contrôle de la masse molaire des polymères soit atteint avec un faible indice de dispersité. L’utilisation de complexes métalliques, pouvant s’oxider et former une liaison métal-carbone, comme agent de piégeage des radicaux est une manière de réaliser ce contrôle. La PRC est alors appelée Polymérisation Radicalaire Contrôlée par voie Organométallique (OMRP). A ce jour, plusieurs métaux de transitions ont été utilisés avec plus ou moins de succès en OMRP. Lors de cette étude, nous avons synthétisé des complexes de cuivre(I) et testé leurs performances pour l’OMRP de l’acétate de vinyle et de l’éthylène. Nous avons également utilisé des outils de chimie théorique pour mieux comprendre pourquoi le cobalt(II) acétylacétonate est, jusqu’à aujourd’hui, le meilleur agent de contrôle pour la polymérisation de l’acétate de vinyle et des amides de vinyle. Grâce à la théorie de la fonctionnelle de densité (DFT), nous avons mis en lumière le rôle crucial de la coordination sur le cobalt des groupements carbonyles des monomères étudiésThis thesis focus on Controlled Radical Polymerization (CRP) of vinyl esters and vinyl amides. One of the possibilities to achieve this control is a dynamic reversible trapping of the growing radical chains (P•) by a controlling agent (T) to form a dormant species (P─T’). The radical concentration in the medium can be dramatically reduced so that the unwanted terminations are disfavored and polymers with controlled molecular weights and low dispersity can be obtained. A way to achieve this control is the use of metallic complexes, which can oxidize and form a metal-carbon bond, as trapping agent in the so-called Organometallic Mediated Radical Polymerization (OMRP). So far, different transition metals have been used with gretaer or smaller success. In this study, the synthesis of copper(I) complexes and their investigation for the vinyl acetate and ethylene polymerization under OMRP conditions were performed. We also used computational chemistry as a tool to better understand why the cobalt(II) acetylacetonate (Co(acac)2) has, so far, given the best results for either vinyl acetate or vinyl amides polymerization. Thanks to Density Functional Theory (DFT), the crucial role of the monomer carbonyl group coordination to cobalt was pointed out
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Weber, Fernanda Hart. "Interações fisico-quimicas entre amidos de milho e hidrocoloides (gomas guar e xantana) e seus efeitos nas propriedades funcionais." [s.n.], 2005. http://repositorio.unicamp.br/jspui/handle/REPOSIP/255894.
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Orientadores: Yoon Kil Chang, Fernanda Paula CollaresTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: O amido é utilizado como agente gelificante na indústria de alimentos. Devido a diversidade de textura que pode ser obtida com o amido, ele é usado para produtos que vão desde sopas líquidas até pudins com consistência sólida, mas é nos produtos de panificação que adquire maior importância, por ser um componente presente naturalmente nas farinhas de cereais. A incorporação de gomas em suspensões de amido modifica as propriedades reológicas, causa aumento da viscosidade, melhora a textura e aumenta a retenção de umidade. O objetivo do presente trabalho foi estudar as interações físico-químicas que ocorrem entre o amido de milho e as gomas guar e xantana. Foram avaliadas suspensões a 10 % de amido de milho normal, amido de milho ceroso e amido de milho com alto teor de amilose, contendo goma guar e goma xantana nas concentrações de 0,15; 0,50; 0,85 e 1 %. Na tentativa de conhecer as interações foram realizadas análises térmicas, análise das propriedades de pasta, avaliação de dureza do gel, difractometria de raio-x, estabilidade à ciclos de congelamento-descongelamento, resistência à hidrólise enzimática (a-amilase) e espectrometria no infravermelho. As gomas guar e xantana modificaram as propriedades de pasta e térmicas dos amidos avaliados, as alterações verificadas foram dependentes do tipo de amido e de goma utilizados. A goma xantana conferiu maior estabilidade ao cisalhamento e ao aquecimento e reduziu a retrogradação do amido de milho normal e ainda, aumentou a entalpia de gelatinização dos amidos. As gomas aumentaram a estabilidade dos géis submetidos a ciclos de congelamento e descongelamento em proporções diferentes, a goma xantana promoveu uma redução de sinérese maior do que a goma guar. Nos géis de amido de milho normal e com alto teor de amilose armazenados sob refrigeração, a adição da goma xantana melhorou a textura e minimizou os efeitos da retrogradação. Verificou-se também, que os géis do amido com alto teor de amilose apresentaram-se mais rígidos que os demais e que a adição da concentração mínima desta goma reduziu significativamente a sua força. A goma xantana também diminuiu a dureza dos géis do amido ceroso, porém com uma intensidade menor devido à menor retrogradação verificada para este amido. Nos géis de amido com alto teor de amilose adicionados da goma guar, observou-se que não houve diminuição da dureza dos géis. A adição das gomas não alterou o padrão de difração de raio-x dos géis dos amidos estudados. Os géis do amido normal adicionados de 1 % das gomas guar e xantana foram menos hidrolisados, se comparados ao gel controle. No amido com alto teor de amilose, verificouse que a goma guar exerceu ação protetora à hidrólise, e no gel de amido ceroso essa proteção foi ocasionada pela goma xantana. Pelos espectros de absorção no infravermelho, verificou-se que as interações mais importantes entre as gomas e os amidos foram as interações de hidrogênio, visualizadas na região entre 2500 a 3650 cm-1. Mostrou-se que no gel retrogradado, o aumento da água livre foi dependente do tipo de amido e da goma, tendo respostas distintas entre eles: (i) a goma guar aumentou a água livre no amido de milho normal e com alta amilose; (ii) a goma xantana diminuiu a água livre nos amidos de milho normal, com alta amilose e ceroso. De acordo com o estudo desenvolvido, pode-se propor a hipótese de que a interação entre o hidrocolóide e o amido seja mais uma interação física (interações de hidrogênio) do que uma interação química, já que não foi verificado o aparecimento de ligações químicas diferentes nos géis dos amidos adicionados de hidrocolóides
Abstract: Starch is used as a gelling agent in the food industry. Due to the diversity of textures that can be obtained using starch, it is used in products from liquid soups to desserts with a solid consistency, however it is in bakery products that starch has the greatest importance, as it is a naturally present component of cereal flours. The incorporation of gums to starch suspensions modifies their rheological properties, increasing viscosity, improving texture and increasing moisture retention. The aim of the present work was to study the physicochemical interactions that occur between corn starch and guar and xanthan gums. Suspensions of 10 % normal, waxy and high amylose corn starch, containing guar gum and xanthan gum in concentrations of 0.15; 0.50; 0.85 and 1 % were evaluated. In a tentative to elucidate these interactions were carried out thermal analyses, pasting properties analysis, texture evaluation, X-ray diffraction, stability to freeze-thaw cycles, resistance to enzymatic hydrolysis (a-amylase) and infra-red espectroscopy. Guar and xanthan gums modified the pasting and thermal properties of the evaluated starches and these were depends of the type of starch and of the gum used. Xanthan gum increased stability to mechanical agitation and heating and reduced retrogradation of normal corn starch, and promoted a slight increase in gelatinization enthalpies of the starches. The gums increased stability to freeze and thaw processes at different levels, the xanthan gum promoted more reduced in syneresis than the gels with guar gum. In the normal and high amylose corn starch gels, stored refrigerated, the addition of xanthan gum improved texture and minimized the effects of retrogradation. It was also observed that the high amylose gels were more rigid than the others and that the addition of xanthan gum at the minimum concentration used reduced their force significantly. This gum also improved the texture of waxy corn starch gels, however, at a lower intensity due to the lower trend to retrograde verified for this starch. There were no reduction in the force of the gels prepared with high amylose starch and guar gum during storage. The addition of guar and xanthan gums to the starch gels did not modify their Xray diffraction patterns. The gels of normal corn starch with 1 % added xanthan and guar gums were hydrolyzed less when compared to the control gel. Guar gum had a protective action against hydrolysis of high amylose starch and xanthan gum protected waxy corn starch. From the infra-red absorption spectra it could be observed that the most important interactions between the gums and the starches are hydrogen bonds, visualized in the region between 2500 and 3650 cm-1, demonstrating that in the retrograded gels the increase of unbound water depends of the type of starch and of the gum, with different responses: (i) guar gum increased unbound water in normal and high amylose maize starches, however it is not detrimental to waxy maize starch; (ii) on the other hand, xanthan gum reduced unbound water in normal, waxy and high amylose maize starches
Doutorado
Doutor em Tecnologia de Alimentos
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Albuquerque, Fabíola Samara Maria de. "Estudo das características estruturais e das propriedades funcionais do amido de sementes de jaca (Artocarpushete-rophylusLam) variedades mole e dura." Universidade Federal da Paraíba, 2012. http://tede.biblioteca.ufpb.br:8080/handle/tede/4038.
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Starch is a polysaccharide used as a source of carbohydrates in the human diet, with wide application in food industry, textile and pharmaceutical industries. The search for new sources starch is growing, causing the production sector is seeking new technologies, as well as natural starches with different chemical and physical characteristics. The objective of this study was to extract and characterize starch from jackfruit seeds, varieties of soft and hard, as their chemical, structural and morphological, thermo-economic and technological. In proxi-mate analysis of starch extracted from jackfruit seeds had a content of 92.81% to 94.49% range for soft and hard variety, thus verifying a high purity in the extraction process. The ob-servation in scanning electron microscopy and optical microscopy showed starch granules with rounded shape, the bell-shaped and some go-presenting regular cuts in its surface, diam-eters ranging from 6 to 11μm-jackfruit soft and lasts for 6-13 μm. The pattern of crystallinity shown by X-ray diffraction for the two varieties was type A. The swelling power and solubili-ty of starches studied increased with increasing temperature, being significantly above the temperature of 75 ˚ C (gelatinisation). Absorption capacity for water and oil, starch of the present study showed a high absorption, and the soft jackfruit obtained the highest values, 123.18 g 100g-1 and 99.58 g 100g-1. The starch gel showed low transmittance values, with folders for the kid-opaque. The maximum viscosity of starch from jackfruit seed of the varie-ty found hard was higher for the variety of soft starch, and starch of the variety you lasts less resistant to mechanical agitation at high temperature (higher breakdown). In Differential Scanning Calorimetry (DSC) showed an initial gelatinization temperature of 36 ˚C and a final temperature of 65 ˚ C for soft jackfruit and jackfruit was last of 40 ˚C and 70 ˚C respectively.
O amido é um polissacarídeo utilizado como fonte de carboidratos na dieta humana, com grande aplicação na indústria de alimentos, têxtil e farmacêutica. A procura por novas fontes amilacéas vem crescendo, fazendo com que o setor produtivo esteja em busca de novas tecno-logias, bem como de amidos naturais com características físico-quimicas diferenciadas. O objetivo deste trabalho foi extrair e caracterizar o amido de semente de jaca, das variedades mole e dura, quanto a sua composição química, estrutural e morfológica, propriedades térmi-cas e tecnológicas. Na analise centesimal o amido extraído da semente de jaca teve um teor de 92,81% para variedade mole e 94,49% para variedade dura, verificando assim uma alta pureza no processo de extração. A observação em microscopia eletrônica de varredura e microscopia óptica mostrou grânulos de amidos com formato arredondados, na forma de sino e alguns ir-regulares apresentando cortes na sua superfície, diâmetros variando de 6-11μm para jaca mole e 6-13 μm para dura. O padrão de cristalinidade mostrado por difratometria de raios-X para as duas variedades foi do tipo A. O poder de intumescimento e solubilidade dos amidos estuda-dos aumentou com o aumento da temperatura, sendo significativo acima da temperatura de 75˚C (gelatinização). Para capacidade de absorção de água e de óleo, o amido do presente estudo mostrou uma alta absorção, sendo que a jaca mole obteve os maiores valores, 123,18 g·100 g-1 e 99,58 g·100 g-1. O gel do amido mostrou valores de transmitância baixos, com pastas de amido opacas. A viscosidade máxima do amido de semente de jaca variedade dura foi maior à encontrada para o amido da variedade mole, sendo o amido da variedade dura me-nos resistente à agitação mecânica a quente (maior quebra). Na Calorimetria Exploratória Di-ferencial (DSC) verificou uma temperatura inicial de gelatinização de 36˚C e uma temperatu-ra final de 65˚C para jaca mole e para jaca dura foi de 40˚C e 70˚C respectivamente.
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Yu, Xue, and 于雪. "Imaging of peritoneal metastasis : evaluation of diagnostic performance of DWI-MRI and FDG-PET/CT, correlation of the functional indices and feasibility study based on amide proton transfer MRI." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hdl.handle.net/10722/193483.
Повний текст джерелаАнотація:
Introduction
Peritoneal metastasis is advanced disease and is usually widely disseminated at the time of discovery. It is crucial to detect peritoneal metastasis at an early stage and to allow precise patient selection for the right treatments. Both
fluorodeoxyglucose positron emission tomography/computed tomography (FDGPET/CT) and magnetic resonance imaging (MRI) are used in peritoneal metastasis detection. Standardized uptake value (SUV), derived from FDGPET/ CT can evaluate glucose metabolism in cells, whilst apparent diffusion coefficient (ADC) derived from diffusion-weighted MRI (DWI) is used for quantitative analysis of tumour cellularity. Amide proton transfer (APT) MRI is a novel imaging technique based on exchangeable amide protons as endogenous contrast agent and can measure the increased amide proton signal in malignant tissues indirectly through bulk water proton signals. This thesis aims to:
1) compare the diagnostic performance of FDG-PET/CT and MRI in peritoneal metastasis evaluation;
2) study the relationship between SUV and ADC in peritoneal metastasis;
3) investigate the feasibility of APT in peritoneal metastasis evaluation.
Materials and Methods
Patients with peritoneal metastasis detected on FDG-PET/CT were prospectively recruited for MRI. FDG-PET/CT and MRI images were reviewed independently by two radiologists in separate sessions. Diagnostic characteristics were calculated for both imaging techniques. SUVmax and SUVmean were obtained by placing ROIs on PET, while ADCmin and ADCmean were calculated by contouring lesions on DWI. APT MRI was performed using a single-slice turbo spin echo sequence, with a block of presaturation pulses at 33 frequency offsets. ROIs were placed on peritoneal metastasis and muscle on APT. Mean of integrated asymmetrical magnetic transfer ratio (MTRasym) over 3-4 ppm with respect to water resonance was calculated for peritoneal metastasis and muscle.
Results
Eight patients were recruited in this study with 128 anatomical sites evaluated.
DWI/MRI had good diagnostic performance (sensitivity = 92%, specificity = 99%, accuracy = 98%) compared to that of FDG-PET/CT (sensitivity = 90%, specificity= 100%, accuracy = 98%). Thirty-four peritoneal metastases were selected for quantitative analysis. Significant inverse correlation was found between ADCmean and SUVmax (r = -0.528, p = 0.001) and between ADCmean and SUVmean (r = -0.548, p = 0.001). ADCmin was significantly and negatively correlated with SUVmax (r = -0.508, p = 0.002) and SUVmean (r = -0.513, p = 0.002).
In the above study cohort, 6 patients underwent APT imaging with 8 peritoneal metastases evaluated. Seven lesions showed positive APT signal and one had negative APT signal. The mean APT signal for peritoneal metastasis was 2.28%±1.76%, significantly different from that of muscle (-2.79%±0.95%, p <
0.001).
Conclusions
In conclusion, both DWI/MRI and FDG-PET/CT had good diagnostic performance in peritoneal metastasis evaluation. The negative correlation between SUV and ADC suggested an inverse relationship between tissue metabolism and cellularity. APT MRI is feasible to generate sufficient contrast signal for peritoneal metastasis and has potential to discriminate peritoneal tumours from its surrounding soft tissue using integrated MTRasym as a quantitative marker. These functional indices allow understanding of the biological behaviours of peritoneal tumours and could act as adjuncts in peritoneal metastasis imaging.published_or_final_version
Diagnostic Radiology
Master
Master of Philosophy
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Booth, Terry W. "Equipping a representative group of leaders of Amite Baptist Church of Denham Springs, Louisiana to develop and initiate a functional strategy for applying selected principles of natural church development." Online full text .pdf document, available to Fuller patrons only, 1999. http://www.tren.com.
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Yamani, Beatriz Valcárcel. "Caracterização físico-química e funcional de amido de tuberosas originárias da América do Sul: oca (Oxalis tuberosas Molina), olluco (Ullucus tuberosus Caldas) e mashua (Tropaeolum tuberosum Ruiz & Pavón)." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/9/9131/tde-31012011-163155/.
Повний текст джерелаАнотація:
A região dos Andes é conhecida por sua grande diversidade genética em vegetais, sobretudo raízes e tubérculos, que apresentam elevado teor de nutrientes. A população rural da região utiliza os tubérculos como alimentos principais do consumo diário, sendo alguns deles a oca (Oxalis tuberosa Molina), o olluco (Ullucos tuberosus Caldas) e a mashua (Tropaeolum tuberosum Ruiz e Pavón), os quais apresentam cores e sabores particulares. Neste trabalho tais alimentos e suas respectivas frações amiláceas foram avaliados quanto à composição. O amido foi caracterizado quanto às propriedades físicas, físico-químicas e funcionais. As amostras obtidas em mercado local de Arequipa - Perú apresentaram diferenças significativas no rendimento de extração do amido. Quando observados por microscopia eletrônica de varredura e microscopia óptica, os grânulos de amido de oca apresentaram morfologia principalmente elipsoide e oval e comprimentos de até 54,30 µm. Grânulos de amido de olluco com comprimentos de até 32,09 µm apresentaram formatos elipsoide, oval, cônico, em forma de pêra e prismático. Os grânulos de amido de mashua com formas esféricas e ovais truncadas apresentaram os menores comprimentos, até 16,29 µm. O conteúdo de fósforo variou: 0,044% (oca), 0,047% (olluco) e 0,081% (mashua). A porcentagem de amilose foi de 27,60 % (oca), 26,49 % (olluco) e 27,44 % (mashua). O amido de olluco apresentou menor poder de intumescimento, formando géis mais opacos e menos duros. Os três amidos mostraram a mesma estabilidade quando mantidos sob refrigeração e apresentaram elevada sinérese sob temperaturas de congelamento, com variação de 40,28% até 74,42 % para amido de olluco. Os amidos apresentaram fácil cozimento, com elevados picos de viscosidade. Estas baixas temperaturas de gelatinização e a elevada estabilidade durante a refrigeração fazem destes amidos matérias-primas apropriadas para uso em diversos produtos e formulações que requeiram temperaturas brandas de processamento e que prescindam de congelamento.The Andean region is known for its great genetic diversity in plants, especially roots and tubers, which have a high nutrient content. The rural population on the region consumes them as staple food daily. Oca (Oxalis tuberosa Molina), olluco (Ullucos tuberosus Caldas) and mashua (Tropaeolum tuberosum Ruiz & Pavón) are the most consumed which are characterized by distinct colors and flavors. In the present work, these foods and their starchy fractions were evaluated in relation to its composition. Starch physical, physical-chemical and functional properties were characterized. Samples obtained from a local market in Arequipa - Peru showed significant differences in starch extraction yield. When observed by scanning electron microscopy and optical microscopy, oca starch granules showed morphology mainly ellipsoidal and oval, with sizes up to 54.30 µm. The olluco starch granules had sizes up to 32.09 µm with ellipsoid, oval, conical, pear-shaped and prismatic shapes. Mashua starch granules with spherical and oval truncated shapes showed smaller dimensions up to 16.29 µm. The phosphorus content varied: 0,044% (oca), 0,047% (olluco) and 0,081% (mashua). The percentage of amylose was 27.60 % (oca), 26.49 % (olluco) and 27.44 % (mashua). Olluco starch showed lower swelling power forming gels more opaque and less hardness. The three starches exhibited the same stability when kept under refrigeration and showed higher syneresis under freezing temperatures, with a variation of 40,28 % to 74.42 % for olluco starch. The results showed easy cooking starches with high peak viscosity. These low temperatures of gelatinization and high stability during the refrigeration make these starches suitable for use in various products and formulations that require milder processing temperatures but without freezing.
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Junior, Manoel Divino da Matta. "Características estruturais, físico-químicas e funcionais dos amidos de mandioca e de milho com diferentes teores de amilose oxidados por ozônio." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/11/11141/tde-29092015-145933/.
Повний текст джерелаАнотація:
A oxidação é um método que visa a modificação do amido por agentes oxidantes diversos, introduzindo grupamentos funcionais e realizando cisão das ligações glicosídicas. Seus objetivos são reduzir a viscosidade do polissacarídeo, elevar a transparência da pasta e limitar sua retrogradação. O objetivo do presente estudo foi modificar os amidos de milho com diferentes teores de amilose e o amido de mandioca pelo tratamento com ozônio e também caracterizar as amostras oxidadas quanto às características moleculares, estruturais e funcionais, correlacionando-as entre si. O processo de oxidação foi efetivo em alterar diversas propriedades e funcionalidades dos amidos estudados, contudo de modos distintos para as diferentes fontes. Tais diferenças decorrem da composição e estrutura granular peculiares de cada um, promovendo diferentes taxas de degradação das lamelas amorfas e cristalinas e da presença de grupos carboxilas. A oxidação pelo ozônio nas condições estudadas reduziu a viscosidade apenas do amido de milho normal; no caso dos amidos de milho ceroso e de mandioca, a viscosidade foi ligeiramente aumentada. O amido de milho de alta amilose não apresentou viscosidade nas condições de analisadas pelo Rapid Visco Analyser, tanto antes como após a oxidação. O setback foi reduzido pelo processo oxidativo com o ozônio para os três amidos, tornando-os mais estáveis. A oxidação aumentou a claridade de pasta de todos os amidos. A ozonização também causou alterações no amido de milho ceroso e no de mandioca, de modo a proporcionar capacidade de expansão no forno, em índices próximos àqueles de amostras comerciais de polvilho azedo. Os demais amidos não se expandiram significativamente. A propriedade de expansão no forno foi afetada principalmente pela variação de entalpia de gelatinização dos amidos, mas também pelos teores de carboxilas e de carbonilas, fator de inchamento, quebra de viscosidade, setback, cristalinidade relativa e tamanho das cadeias ramificadas de amilopectina (cadeias B2 e B3 e tamanho médio). O uso do ozônio, portanto, poderá ser útil nesta modalidade de modificação dos amidos e, em especial para o amido de mandioca ou de milho ceroso, capacitando-os para a expansão no forno, o que poderia gerar produtos panificáveis mais padronizados do que os obtidos pelo polvilho azedo, ou sem as consequências da oxidação por métodos químicos mais agressivos, como o uso do hipoclorito de sódio.Oxidation is a method which aims the starch modification by various oxidizing agents, introducing functional groups and performing the cleavage of glycosidic linkages. Its objectives are to reduce the polysaccharides viscosity, raising the transparency paste and minimizing retrogradation. The aim of this study was to modify the corn starch with different levels of amylose and the cassava starch using ozone and also to characterize the samples oxidized as the molecular, structural and functional characteristics, relating them with each other. The oxidation process was effective changing several properties and features of the studied starches, however, in different ways for the different sources. These differences come from having starches different composition and granular structure, providing different rates of degradation of amorphous and crystalline lamellae and the presence of carbonyl groups, and carboxyl formed. A reduction in viscosity was observed for the normal corn starch after oxidation, and an increase for the waxy maize and cassava starches. The high amylose corn starch showed no viscosity by Rapid Visco Analyser, before or after oxidation. The setback was reduced by the oxidation process with ozone for the three starches, rendering them more stable. Oxidation by ozone under the conditions studied increased paste clarity of all starches. Ozonation caused changes in the waxy corn and cassava starches, providing baking properties, in indices close to those of commercial samples of sour cassava starch. The other starches are not expanded significantly in the oven. The baking property was mostly affected by enthalpy of gelatinization of starches, but also by carboxyl and carbonyl contents, swelling factor, breakdown, setback, relative crystallinity and size of amylopectin branched chains (B2, B3 and medium size). So, the use of ozone may be useful in this starch modification modality, and in particular for cassava or waxy maize starches, enabling the expansion in oven, which could generate more standardized baking products than those obtained by sour cassava starch, or without consequences of oxidation using more aggressive chemical methods, such as sodium hypochlorite.
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Mora, Anne-Sophie. "Élaboration de revêtements époxy pour contact alimentaire à empreinte environnementale réduite A perspective approach on the amine reactivity and the hydrogen bonds effect on epoxy-amine systems vanillin-derived amines for bio-based thermosets synthesis of biobased reactive hydroxyl amines by amination reaction of cardanol-based epoxy monomers synthesis of pluri-functional amine hardeners from bio-based aromatic aldehydes for epoxy amine thermosets cardanol-based epoxy monomers for high thermal properties thermosets." Thesis, Montpellier, Ecole nationale supérieure de chimie, 2019. http://www.theses.fr/2019ENCM0012.
Повний текст джерелаАнотація:
Les travaux de thèse présentés sont issus d’une collaboration industrielle avec la société Nouvelle Sogatra, spécialisée dans la conception, la fabrication et la commercialisation de revêtements de protection bi-composants répondant aux normes d’alimentarité. L’objectif principal de ce projet est de proposer de nouveaux revêtements époxydiques performants en utilisant des produits biosourcés et, dans l’idéal, moins dangereux pour l’Homme et pour l’environnement. Ces travaux de thèse s’axent autour de l’identification de nouvelles méthodologies de synthèse de durcisseurs aminés biosourcés qui soient facilement applicables industriellement.L’amination directe des groupements époxy par ouverture de cycle en présence d’ammoniaque ainsi que l’amination réductrice via la synthèse d’imine ont été sélectionnées comme voies de synthèse pour leur facilité d’application et leur caractère respectueux de l’environnement. Pour cela, des précurseurs commerciaux biosourcés et/ou à toxicité réduite ont été sélectionnés. De nouveaux durcisseurs aminés ont été synthétisés à partir de bio ressources telles que la vanilline, le cardanol et le benzaldéhyde. Ces durcisseurs ont ensuite été utilisés pour la synthèse de système époxy-amine thermodurcissables dont les propriétés physico-chimiques et thermodynamiques ont été caractériséesThe presented PhD works were initiated by an industrial collaboration with the company Nouvelle Sogatra, specialized in the design, manufacturing and marketing of two component protective coatings for food contact. The aim of this project is to offer new high-performance epoxy thermosets from bio based reactants and, ideally with a low impact on the health and the environment. This PhD works focus on the identification of new synthesis methodologies of bio-based amine hardeners, which could be easily industrialized.The direct epoxy amination by ring opening using ammonia and the reductive amination via imine synthesis were selected as synthesis routes for their simple utilization and their eco friendly character. Hence, bio based and/or reduced toxicity commercial precursors were selected. New amine hardeners were synthesized from bio resources, such as vanillin, cardanol and benzaldehyde. These hardeners were then used to synthesize epoxy-amine thermosets, whose thermomechanical and physicochemical properties were characterized
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Ben, Youssef Ismaïl. "Synthèse et caractérisation de nouveaux polymères comportant un nombre contrôlé de sites basiques : application à la détection du dioxyde de soufre par des microcapteurs à onde acoustique de surface." Thesis, Vandoeuvre-les-Nancy, INPL, 2010. http://www.theses.fr/2010INPL043N/document.
Повний текст джерелаАнотація:
Ce travail a pour objectif de développer de nouveaux microcapteurs à onde acoustique de surface (SAW) capables de détecter le dioxyde de souffre (SO₂) à l’échelle de traces par l’intermédiaire d’une couche sensible à base d’un polymère fonctionnel. Une famille originale de cinq polyuréthaneimides (PUIs) à blocs contenant un nombre contrôlé de sites amines tertiaires de structures différentes a été synthétisée et caractérisée. Ces matériaux présentent des propriétés originales, en solution et à l’état solide, qui sont dues essentiellement à la présence des sites basiques et à la structure à blocs associant des blocs souples polyéthers et des blocs rigides en partie fluorés. Leur excellent caractère filmogène a permis leur application en tant que couche sensible au SO₂ sur des microcapteurs SAW. Deux structures de microcapteurs à onde de Love, bicouche et tri-couche, ont été développées en respectant les conditions de génération de l’onde. La structure bicouche comporte le Quartz-ST 90° comme substrat et l’un des PUIs joue le double rôle de couche guidante et sensible. Cette structure génère bien l’onde de Love mais elle présente une forte sensibilité à la température, inconvénient majeur pour les capteurs de gaz. L’ajout d’une couche guidante à base de ZnO, dans une structure tri-couche, a permis de rendre le dispositif peu sensible à la température et donc compatible avec l’application visée. Les résultats des tests de détection du SO₂ montrent que tous les PUIs étudiés contribuent à une amélioration de la sensibilité comparativement au dispositif sans couche polymère. La présence des sites amines tertiaires conduit à une amélioration importante de la sensibilité qui n’est pas seulement gouvernée par leur basicité mais également par leur encombrement stérique dont le rôle apparaît déterminantThis work aimed at developing new surface acoustic wave (SAW) microsensors capable of detecting traces of sulfur dioxide (SO₂) through a sensitive layer based on a functional polymer. An original family of five polyurethaneimide (PUI) block copolymers containing a controlled number of tertiary amine sites with different chemical structures was synthesized and characterized. These materials exhibited original properties in solution and solid state, which were mainly due to the presence of the basic sites and the block structure combining polyether soft blocks and partially fluorinated hard blocks. Their excellent film-forming character allowed their application as SO₂ sensitive layers on SAW microsensors. Two bi-layer and three-layer structures of Love wave microsensors were developed by respecting the conditions of the Love wave generation. The bi-layer structure included the Quartz ST-90° as the piezoelectric substrate and one of the PUIs acting as both guiding and sensitive layer. This structure generated the Love wave but its high sensitivity to temperature was a major drawback for gas sensors. The addition of a ZnO guiding layer in a three-layer structure led to a microsensor almost insensitive to temperature and thus compatible with the targeted application. The experimental results for SO₂ detection showed that all the PUIs contributed to improve the sensitivity compared to the device without polymer layer. The presence of tertiary amine sites led to a significant improvement in gas sensitivity which was not only governed by their basicity but also by their steric hindrance which played a determining role
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Silva, Izis Rafaela Alves. "Caracterização do extrato amiláceo nativo e modificado quimicamente da semente de abacate (Persea americana Mill)." Universidade Federal da Paraíba, 2011. http://tede.biblioteca.ufpb.br:8080/handle/tede/4033.
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Recent years have seen a significant increase in demand for starches with specific properties, leading to the modification of these properties in order to get ideal for your application. The objective of this study was to obtain information about the properties of starch from avocado seed cv. "Butter" and submit it to the modification by acetylation and cross-linking, to provide rheological characteristics applicable in obtaining food. The native starch showed starch content of 74.47 % in the physical-chemical analysis and performance of the extraction process used in 11.36%. The degree of substitution (GS) of native starch by acetylation was 0.007 and 0.006 for cross-linking. The native starch granules and had modified oval and circular, their dimensions ranging from 26 to 26.34 μm for the smaller diameter and 35.75 to 36.85 μm for the larger diameter. The pattern of crystallinity shown by X-ray diffraction was type C. The swelling power and solubility at temperatures 75, 85 and 95 °C was maximum for the native starch and modified by acetylation in relation to cross-linking. The changes reduced the ability of native starch hydrophilic and hydrophobic increased their capacity. The native starch gel showed an opaque folder, and with a tendency to retrogradation, modified with acetic anhydride showed no difference compared to the native whereas modification by cross-linking improved the clarity of the folder and decreased the tendency to retrogradation. Stability to freezing and thawing all samples released water in the first cycle, but with each passing day there was a decrease in syneresis. The acetylated starch did not differ from native in the analysis of viscosity has low viscosity and a greater tendency to retrogradation. The starch is modified by cross-linking showed efficacy by introducing cross-links in native starch granule and its peak viscosity was well below the value obtained in native, just had a lower tendency to retrogradation. In Differential Scanning Calorimetry (DSC) was an initial decrease in temperature for starch modified by cross-linking, and all samples did not differ significantly in peak temperature.
Nos últimos anos houve um aumento expressivo na procura por amidos com propriedades específicas, levando à modificação dos mesmos a fim de obter propriedades ideais para sua aplicação. O objetivo deste trabalho foi obter informações a respeito das propriedades do amido da semente de abacate cv. Manteiga e submetê-lo à modificação por acetilação e cross-linking, a fim de oferecer características reológicas aplicáveis na obtenção de produtos alimentares. O amido nativo apresentou teor de amido de 74,47 % na análise físico-química e rendimento para o processo de extração utilizado de 11,36 %. O grau de substituição (GS) do amido nativo por acetilação foi de 0,007 e por cross-linking de 0,006. Os grânulos de amido nativo e modificado apresentaram formato oval e circular, suas dimensões variam de 26 a 26,34 μm para o diâmetro menor e de 35,75 a 36,85 μm para o diâmetro maior. O padrão de cristalinidade mostrado por difratometria de raios-X foi do tipo C. O poder de intumescimento e a solubilidade nas temperaturas 75, 85 e 95 ºC foi máxima para o amido nativo e modificado por acetilação em relação ao cross-linking. As modificações reduziram a capacidade hidrofílica do amido nativo e aumentaram a sua capacidade hidrofóbica. O gel do amido nativo apresentou uma pasta opaca e com tendência a retrogradação, a modificação com anidrido acético não apresentou diferença em relação ao nativo enquanto que, a modificação por cross-linking melhorou a claridade da pasta e diminuiu a tendência a retrogradação. Na estabilidade ao congelamento e descongelamento todas as amostras liberaram água no primeiro ciclo, mas com o passar dos dias houve uma diminuição da sinérese. O amido acetilado não divergiu do nativo na análise de viscosidade apresentando baixa viscosidade e maior tendência a retrogradação. O amido modificado por cross-linking apresentou eficácia com a introdução de ligações cruzadas no grânulo de amido nativo e seu pico de viscosidade foi bem abaixo do valor obtido no nativo, logo teve menor tendência a retrogradação. Na Calorimetria Exploratória Diferencial (DSC) houve uma diminuição da temperatura inicial para o amido modificado por cross-linking, sendo que todas as amostras analisadas não diferiram significativamente na temperatura de pico.
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Sanabria, Gerby Giovanna Rondán. "Propriedades físico-químicas do amido isolado, estudo de parâmetros enzimáticos durante o armazenamento e caracterização de enzimas amilolíticas em raízes de maca (Lepidium meyenii Walp)." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/9/9131/tde-05082011-165059/.
Повний текст джерелаАнотація:
A maca (Lepidium meyenii Walpers) é uma planta herbácea bienal da família Brassicae, cultivada principalmente na região dos Andes da América do Sul. A parte subterrânea vem sendo consumida por muito tempo devido a seu valor nutricional e energético, mas é mais conhecida no mercado peruano e internacional por alegadas propriedades terapêuticas. Esta raiz apresenta até 76% de carboidratos, dos quais 30% é amido. Este trabalho teve como objetivos estudar: as propriedades físico-químicas e funcionais do amido isolado; os parâmetros enzimáticos durante o armazenamento e a purificação parcial de enzimas amilolíticas. Em relação às propriedades do amido, este apresentou um teor de amilose de 20% valor semelhante aos encontrados em raízes e tubérculos similares. A turbidez das suspensões de amido apresentou estabilidade durante o armazenamento. A temperatura de gelatinização e a viscosidade da pasta foram a 45,7° e 46°C, respectivamente. Com base nos dados obtidos, o amido de maca seria indicado para alimentos que requeiram temperaturas moderadas no processamento, não sendo apropriado para o emprego em alimentos congelados. Os parâmetros enzimáticos medidos tais como teor de amido total, teor de açúcares solúveis, atividade amilolítica total, atividade de α e β amilases, não mostraram diferenças significativas entre as medidas durante um período de armazenamento de 16 dias. As microscopias eletrônicas de varredura (MEV) dos grânulos de amido mostraram grãos íntegros com superfícies lisas, com algumas depressões ao redor dos grânulos os quais poderiam indicar o inicio de ataque enzimático, ou fraturas na purificação. Em relação à purificação de enzimas amilolíticas, foi possível separar uma fração ativa com a carboximetilcelulose (CMC) seguida de cromatografia liquida de alta resolução (CLAE) que permitiu a separação de duas frações protéicas, analisadas por eletroforese SDS-PAGE e eletroforese bidimensional (2D). Os polipeptídeos identificados no gel 2D apresentaram massa molecular semelhante entre 22 a 27 kDa, e os pontos isoelétricos entre 4,8 e 7,3.Maca (Lepidium meyenii Walpers) is a biennial herbaceous plant from Brassicae family, grown mainly in the Andes of South America. The underground part has been consumed for a long time due to its nutritional value and energy, but is best known in the Peruvian and international market for alleged therapeutic properties. This root has up to 76% carbohydrates, of which 30% is starch. This work aimed to study: the physico-chemical properties of isolated starch, the enzymatic parameters during storage and partial purification of amylases. In relation to the properties of starch, the amylose content showed a 20% value similar to those found in roots and tubers alike. The turbidity of starch suspensions was stable during storage. The gelatinization temperature and viscosity of the paste were 45.7 ° and 46 ° C, respectively. Based on data obtained from the starch of litter would be given to foods that require moderate temperatures in processing and is not suitable for use in frozen foods. The enzymatic parameters measured such as total starch content, soluble sugars, total amylolytic activity, activity of α and β amylases, showed no significant differences between the measures over a storage period of 16 days. Electronic microscopy (SEM) of starch granules showed grains with smooth surfaces, with some depressions around the granules which could indicate the beginning of enzymatic attack, or fractures in the purification. Regarding the purification of amylases was possible to separate an active fraction with carboxymethylcellulose (CMC) followed by high-resolution liquid chromatography (HPLC) which allowed the separation of two protein fractions, analyzed by SDS-PAGE and two-dimensional electrophoresis (2D ). The polypeptides had a molecular mass between 22 and 27 kDa and isoelectric points ranging from 4.8 to 7.3.
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Yang, Ying, Pengkai Qi, Yonghui Ding, Manfred F. Maitz, Zhilu Yang, Qiufen Tu, Kaiqin Xiong, Yang Leng, and Nan Huang. "A biocompatible and functional adhesive aminerich coating based on dopamine polymerization." Royal Society of Chemistry, 2015. https://tud.qucosa.de/id/qucosa%3A36255.
Повний текст джерелаАнотація:
Amine groups physiologically play an important role in regulating the growth behavior of cells and they have technological advantages for the conjugation of biomolecules. In this work, we present a method to deposit a copolymerized coating of dopamine and hexamethylendiamine (HD) (PDAM/HD) rich in amine groups onto a target substrate. This method only consists of a simple dip-coating step of the substrate in an aqueous solution consisting of dopamine and HD. Using the technique of PDAM/HD coating, a high density of amine groups of about 30 nmol cm⁻² was obtained on the target substrate surface. The PDAM/HD coating showed a high cross-linking degree that is robust enough to resist hydrolysis and swelling. As a vascular stent coating, the PDAM/HD presented good adhesion strength to the substrate and resistance to the deformation behavior of compression and expansion of a stent. Meanwhile, the PDAM/HD coating exhibited good biocompatibility and attenuated the tissue response compared with 316L stainless steel (SS). The primary amine groups of the PDAM/HD coating could be used to effectively immobilize biomolecules containing carboxylic groups such as heparin. These data suggested the promising potential of this PDAM/HD coating for application in the surface modification of biomedical devices.
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Waller, Bradley A. "Properties of p-adic C^k Distributions." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1385485834.
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Tay, Ming Kiong Michael. "Les carbanions alpha-phosphonylés, agents de transfert fonctionnel : applications synthétiques." Rouen, 1987. http://www.theses.fr/1987ROUES043.
Повний текст джерелаАнотація:
Cette étude développe les avantages de la voie carbanionique dans la préparation des phosphonates fonctionnels. La condensation des carbanions d'alkyphosphonates avec des précurseurs fonctionnels appropriés permet d'accéder aux énamines, amides et esters alpha-phosphorylés alpha-substitués. Elle permet d'introduire sur le carbone en alpha des substituants non accessibles par la synthèse traditionnelle de Michaelis-Arbusov. La stabilisation de l'intermédiaire réactionnel par complexation du cation avec le groupe phosphoryle assure sa formation facile et sa protection contre des attaques secondaires non-desirées. Toutefois, cette espèce carbanionique est suffisamment nucléophile vis-a-vis de divers aldéhydes et peut être utilisée directement dans une réaction de Wittig-Horner "in situ" pour la synthèse des imines, amides et esters alpha, bêta-insaturés, alpha-substitués. Ce schéma permet donc de préparer des phosphonates fonctionnels alpha-substitués ou de transférer directement la fonction lors de la réaction d'oléfination sans isoler le phosphonate intermédiaire
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Dan, Milana Cara Tanasov. "Avaliação da potencialidade da farinha de banana verde como ingrediente funcional: estudo in vivo e in vitro." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/9/9132/tde-04042013-103809/.
Повний текст джерелаАнотація:
A cada dia cresce o interesse por alimentos ricos em carboidratos não disponíveis em virtude da relação inversa entre seu consumo e o risco de doenças crônicas não transmissíveis (DCNT). No presente trabalho, foi avaliado o potencial fisiológico da farinha de banana verde (FBV) como ingrediente funcional. Em ratos adultos, foi realizado ensaio de média duração (28 dias) para avaliação do efeito trófico da FBV sobre o intestino grosso e de parâmetros relacionados à tolerância à glicose. Em humanos, foram realizados ensaios clínicos de curta e média duração para avaliação dos efeitos sobre resposta glicêmica; liberação de hormônios gastrintestinais relacionados à saciedade; status antioxidante; fome e saciedade; e funcionamento intestinal. A FBV foi produzida com banana verde, Musa acuminata, de acordo com patente depositada pelo grupo (Patente (RPI - 1941), 2008). A FBV é uma fonte concentrada de carboidratos não disponíveis, com 56% de AR e 8% de FAT na base integral. A adição de FBV nas rações provocou efeito trófico no ceco dos animais, evidenciado por aumento no índice metafásico, número de células da cripta e profundidade das criptas. Além disso, a ração com FBV proporcionou melhora nos parâmetros relacionados à tolerância à glicose. Em voluntários saudáveis, a ingestão de uma única refeição adicionada de 8 g de FBV proporcionou aumento na saciedade e boa correlação entre os parâmetros fome/saciedade e níveis plasmáticos de grelina e insulina, melhorou o funcionamento intestinal, além de resultar em alta fermentabilidade in vitro em relação à lactulose. Após ingestão diária da FBV por 14 dias, os resultados da ingestão de RC0 (refeição controle antes do tratamento) e de RC14 (RC0 após 14 dias de tratamento) mostraram que ocorre melhora na tolerância à glicose, evidenciada pela menor liberação de insulina durante o GTT. O efeito positivo sobre funcionamento intestinal, sobre saciedade e sobre liberação de hormônios gastrintestinais no plasma permaneceu após ingestão prolongada da FBV. A adição da FBV na refeição resultou em aumento da capacidade antioxidante in vitro. A FBV apresenta inúmeros atributos positivos para elaboração de produtos que ampliem as opções para uma alimentação saudável, bem como propiciem saúde intestinal, visando a diminuição do risco de DCNT.The study of unavailable carbohydrates has been of great concern due to their inverse relation with the risk for non-transmissible chronic diseases (NTCD). In the present study, the functional potential of unripe banana flour (UBF) was evaluated. In rats, a medium-term assay was carried in order to evaluate parameters related to glucose tolerance and the trophic effect of UBF on the large bowel. In healthy volunteers, short and medium-term clinical assays were carried to evaluate the effects of UBF on glycemic response; release of gastrointestinal hormones related to satiety (ghrelin, leptin and insulin); antioxidant status; hunger and satiety; and intestinal health. UBF was produced with unripe banana, Musa acuminata, subgroup Cavendish, maturation stage I, in industrial scale and according to a patent deposited by the group (Patent (RPI - 1941), 2008). UBF is a concentrated source of unavailable carbohydrates, with 56% RS and 8% DF (wet weight). Adding UBF in rat rations resulted in a trophic effect in the animals\' cecum, which was evidenced by increase in the metaphasic index, number of crypt cells and crypt depth. Moreover, the ration with UBF resulted in better glucose tolerance parameters. In healthy volunteers, adding UBF (8 g) to an only meal provided significant satiety and good correlation between the parameters hunger/ satiety and plasmatic levels of ghrelin and insulin, improved bowel habit, as well as resulted in high in vitro fermentability in relation to lactulose. After daily intake of UBF for 14 days, the results of the intake of RC0 (control meal before treatment) and RC14 (RC0 after 14 days treatment) showed that there is a positive post-prandial variation in the plasmatic concentrations of gastrointestinal hormones, as well as improvement in glucose tolerance, evidenced by lower insulin release during GTT. The positive effect on bowel habit, satiety and release of gastrointestinal hormones in plasma was kept after prolonged intake of UBF. Adding UBF to the meal provided significant increase in the in vitro antioxidant capacity. UBF presents several positive attributes for the elaboration of products that may increase the options for healthy eating habits, as well as provide intestinal health, always aiming to decrease the risk for NTCD.
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Hassan, E., P. Deshpande, F. Claeyssens, Stephen Rimmer, and S. MacNeil. "Amine functional hydrogels as selective substrates for corneal epithelialization." 2014. http://hdl.handle.net/10454/10459.
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NoThe aim of this study was to develop a synthetic hydrogel to act as a corneal substitute capable of selectively supporting the adhesion and proliferation of limbal epithelial cells (LECs) while inhibiting growth of limbal fibroblasts. Deficiency of LECs causes conjunctival epithelial cells to move over the cornea, producing a thick scar pannus. Unilateral defects can be treated using LEC cultured from the unaffected eye, transplanting them to the affected cornea after scar tissue is removed. The underlying wound bed is often damaged, however, hence the need to develop a corneal inlay to aid in corneal re-epithelialization. Transparent epoxy-functional polymethacrylate networks were synthesized using a combination of glycerol monomethacrylate, ethylene glycol dimethacrylate, lauryl methacrylate and glycidyl methacrylate that produced two different bulk hydrogel compositions with different equilibrium water contents (EWCs): Base 1 and Base 2, EWC=55% and 35%, respectively. Two sets of amine-functional hydrogels were produced following reaction of the epoxide groups with excesses of either ammonia, 1,2-diamino ethane, 1,3-diamino propane, 1,4-diamino butane or 1,6-diamino hexane. Neither series of hydrogels supported the proliferation of limbal fibroblasts irrespective of amine functionalization but they both supported the adhesion and proliferation of limbal epithelial cells, particularly when functionalized with 1,4-diamino butane. With Base 1 hydrogels (less so with Base 2) a vigorous epithelial outgrowth was seen from small limbal explants and a confluent epithelial layer was achieved in vitro within 6days. The data support the development of hydrogels specific for epithelial formation.
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Rajakumari, P. Maria Nirmal. "Network Formation In Amine Curing Of Higher Functional Epoxy Resins." Thesis, 1996. https://etd.iisc.ac.in/handle/2005/1872.
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