896 resultados para NMR symbols and terms


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Dissertação de Mestrado em Solicitadoria

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Dissertation presented to obtain the Ph.D degree in Biochemistry, Neuroscience

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Dissertação para Obtenção do grau de Mestrado em Arte e Ciência do Vidro

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My aim was to produce a dissertation, based on Rayuela, which focuses on Cortázar’s questioning of identity. With this objective in mind, I have studied some of the salient elements in the novel that relate to this topic and the subsequent, interrelated, areas of study that arose in doing so. The cities of Paris and Buenos Aires are placed in contrast within the novel and reflect a dichotomy that reflects Oliveira’s condition as a “foreigner,” (more specifically as a South American in Europe). This duality is further reflected in Cortázar’s use of gender, and the development of the notions of active and passive, and an investigation into the traditional modes of thought, symbols, and stereotypes, and an open-ended questioning of their validity. These topics are framed by a notion of Judeo-Christian History that is in many ways flawed and, as such, contrasts with a more intuitive (or “oriental”) perception of reality, which is centred in figures such as la Maga. I found many explicit references to Zen philosophy, and related oriental references, that led me to believe that this area was worthy of further investigation. Rayuela is considered a classic novel within the canon of Spanish language literature. It’s famous “tabla,” like the rules for a game between the writer and the receptor that produce alternative readings, has led to many discussions regarding the novel’s structure and form, and also created a certain amount of polemic with the use of concepts such as the “lector hembra.” Many consider Cortázar a greater short story writer than a novelist, but nevertheless this novel had a profound effect on young readers upon its publication, much to Cortázar’s surprise, and continues to attract readers, dealing as it does with issues that continue to be relevant to many people.

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Ionic Liquids (ILs) consist in organic salts that are liquid at/or near room temperature. Since ILs are entirely composed of ions, the formation of ion pairs is expected to be one essential feature for describing solvation in ILs. In recent years, protein - ionic liquid (P-IL) interactions have been the subject of intensive studies mainly because of their capability to promote folding/unfolding of proteins. However, the ion pairs and their lifetimes in ILs in P-IL thematic is dismissed, since the action of ILs is therefore the result of a subtle equilibrium between anion-cation interaction, ion-solvent and ion-protein interaction. The work developed in this thesis innovates in this thematic, once the design of ILs for protein stabilisation was bio-inspired in the high concentration of organic charged metabolites found in cell milieu. Although this perception is overlooked, those combined concentrations have been estimated to be ~300 mM among the macromolecules at concentrations exceeding 300 g/L (macromolecular crowding) and transient ion-pair can naturally occur with a potential specific biological role. Hence the main objective of this work is to develop new bio-ILs with a detectable ion-pair and understand its effects on protein structure and stability, under crowding environment, using advanced NMR techniques and calorimetric techniques. The choline-glutamate ([Ch][Glu]) IL was synthesized and characterized. The ion-pair was detected in water solutions using mainly the selective NOE NMR technique. Through the same technique, it was possible to detect a similar ion-pair promotion under synthetic and natural crowding environments. Using NMR spectroscopy (protein diffusion, HSQC experiments, and hydrogen-deuterium exchange) and differential scanning calorimetry (DSC), the model protein GB1 (production and purification in isotopic enrichment media) it was studied in the presence of [Ch][Glu] under macromolecular crowding conditions (PEG, BSA, lysozyme). Under dilute condition, it is possible to assert that the [Ch][Glu] induces a preferential hydration by weak and non-specific interactions, which leads to a significant stabilisation. On the other hand, under crowding environment, the [Ch][Glu] ion pair is promoted, destabilising the protein by favourable weak hydrophobic interactions , which disrupt the hydration layer of the protein. However, this capability can mitigates the effect of protein crowders. Overall, this work explored the ion-pair existence and its consequences on proteins in conditions similar to cell milieu. In this way, the charged metabolites found in cell can be understood as key for protein stabilisation.

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In recent years the research of sensors with good sensitivity and good selectivity in aqueous medium has been of great interest. Chemosensors soluble in aqueous media are very interesting, because of the importance in revealing a number of biological processes, disease states and environmental pollutions. 2,4,5-Triaryl-imidazoles are versatile compounds with application in medicine, due to their biological activity, and materials sciences, for their interesting optical properties. These properties can be tuned by careful selection of substituents at positions 2, 4 and 5: replacement of the aryl group by a heterocyclic group results in larger π-conjugated systems with improved optical properties for application in nonlinear optics, OLEDs, DNA intercalators, and chemosensors. In this communication, we report the synthesis of new phenanthroimidazoles, substituted at position 2 with (hetero)aryl groups of different electronic character, in order to evaluate their photophysical properties and chemosensory ability. The new derivatives were characterized by the usual techniques and a detailed photophysical study was undertaken. The evaluation of the compounds as fluorimetric chemosensors was carried out by performing titrations in acetonitrile and acetonitrile/water in the presence of relevant organic and inorganic anions, and of alkaline, alkaline-earth and transition metal cations.

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Three coumarins, 5-methoxypsoralene, xanthyletin, and (-)-marmesin, have been isolated from the ethanolic extract of the stem of the Amazonian plant Brosimum potabile. The structures were determined on the basis of NMR analyses and by comparison with spectroscopic data in the literature. The analysis of the hexane fractions by GC-MS in EIMS mode suggested the presence of (1-methylpentyl)-benzene; α,α-dimethyl-4-(1-methylethyl)-benzenemethanol; 1-methyl-3,5-bis(1-methylethyl)-benzene; urs-12-ene; chola-5,22-dien-3β-ol; cholesta-4,6-dien-3β-ol; sitosteryl 9(Z)-octadecenoate; cholesta-5,22-dien-3β-ol; cholesta-4,6,22-trien-3-one; and cholesta-4,22-dien-3-one. NMR data of other hexane fractions indicated the presence of 3β-acetoxy-lup-12,20(29)-diene; 3β-acetoxy-olean-12-ene; 3β-acetoxy-urs-12-ene; and adian-5-ene. All these compounds are first described in B. potabile.

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ABSTRACT The Amazon forest is rich in plant species diversity, among them,Piranhea trifoliata stands out, which is popularly known as piranheira, because their fruits are eaten by fish. Their barks are used as bath composition on uterus inflammation and as tea in malaria treatment. This study aimed to fractionate the dichloromethane and dichloromethane phase from methanolic extract of leaves of Piranhea trifoliata. The leaves were dried, grounded and extracted with dichloromethane, methanol and water. The methanol extract was partitioned with dichloromethane and ethyl acetate. The chromatographic fractionation yielded six pentacyclic triterpenoids: friedelan-3-one, 28-hydroxy-friedelan-3-one, 30-hydroxy-friedelan-3-one, lupeol, α- and β-amyrin mixture, besides the mixture of the steroids: β-sitosterol and stigmasterol. The substances structures were identified by 1H- and13C-Nuclear Magnetic Resonance (NMR) analysis and literature data comparison. This is the first report describing the chemical study of P. trifoliata leaves.

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In this paper the construction of Reed-Solomon RS(255,239) codeword is described and the process of coding and decoding a message is simulated and verified. RS(255,239), or its shortened version RS(224,208) is used as a coding technique in Low-Power Single Carrier (LPSC) physical layer, as described in IEEE 802.11ad standard. The encoder takes 239 8-bit information symbols, adds 16 parity symbols and constructs 255-byte codeword to be transmitted through wireless communication channel. RS(255,239) codeword is defined over Galois Field GF and is used for correcting upto 8 symbol errors. RS(255,239) code construction is fully implemented and Simulink test project is constructed for testing and analyzing purposes.

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Type 1 diabetes can affect hippocampal function triggering cognitive impairment through unknown mechanisms. Caffeine consumption prevents hippocampal degeneration and memory dysfunction upon different insults and is also known to affect peripheral glucose metabolism. Thus we now characterized glucose transport and the neurochemical profile in the hippocampus of streptozotocin-induced diabetic rats using in vivo(1)H NMR spectroscopy and tested the effect of caffeine consumption thereupon. We found that hippocampal glucose content and transport were unaltered in diabetic rats, irrespective of caffeine consumption. However diabetic rats displayed alterations in their hippocampal neurochemical profile, which were normalized upon restoration of normoglycaemia, with the exception of myo-inositol that remained increased (36 +/- 5%, p < 0.01 compared to controls) likely reflecting osmolarity deregulation. Compared to controls, caffeine-consuming diabetic rats displayed increased hippocampal levels of myo-inositol (15 +/- 5%, p < 0.05) and taurine (23 +/- 4%, p < 0.01), supporting the ability of caffeine to control osmoregulation. Compared to controls, the hippocampus of diabetic rats displayed a reduced density of synaptic proteins syntaxin, synaptophysin and synaptosome-associated protein of 25 kDa (in average 18 +/- 1%, p < 0.05) as well increased glial fibrillary acidic protein (20 +/- 5%, p < 0.05), suggesting synaptic degeneration and astrogliosis, which were prevented by caffeine consumption. In conclusion, neurochemical alterations in the hippocampus of diabetic rats are not related to defects of glucose transport but likely reflect osmoregulatory adaptations caused by hyperglycemia. Furthermore, caffeine consumption affected this neurochemical adaptation to high glucose levels, which may contribute to its potential neuroprotective effects, namely preventing synaptic degeneration and astrogliosis.

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(Résumé de l'ouvrage) This collection of studies in honor of François Bovon highlights the rich diversity found within early expressions of Christianity as evidenced in ancient texts, traditions, symbols, and motifs. Old labels like 'apocrypha' or 'heresy' that for centuries have suppressed much of this evidence are removed, previous assumptions are questioned, and the old data are examined afresh along with the latest discoveries. The studies fall into six areas: ancient gospels, acts, early Christian movements, ancient interpretations, art, and manuscripts. Contributors include James Robinson, Helmut Koester, Harold Attridge, Karen King, and Jean-Daniel Kaestli.

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(Résumé de l'ouvrage) This collection of studies in honor of François Bovon highlights the rich diversity found within early expressions of Christianity as evidenced in ancient texts, traditions, symbols, and motifs. Old labels like 'apocrypha' or 'heresy' that for centuries have suppressed much of this evidence are removed, previous assumptions are questioned, and the old data are examined afresh along with the latest discoveries. The studies fall into six areas: ancient gospels, acts, early Christian movements, ancient interpretations, art, and manuscripts. Contributors include James Robinson, Helmut Koester, Harold Attridge, Karen King, and Jean-Daniel Kaestli.

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La investigació vol identificar i analitzar les manifestacions, icones i estratègies utilitzades pel poder polític al Marroc per a ressaltar la seva presència pública i social en alguns espais urbans de les ciutats, en particular a Tetuan. La utilització d'una determinada simbologia i l'ocupació o apropiació d'espais urbans per part del poder polític (sobretot monarquia i govern) possiblement representa una estratègia de presència pública i transmet explícitament o implícitament certs valors i missatges relacionats amb el poder.

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5.11.2014 This report was prepared independently by Mr McLoughlin with the support of the health insurers, and the Health Insurance Authority, for consideration by the Minister for Health and the insurers.  All parties were very conscious of the importance of respecting competition law when dealing with issues such as prices and costs. The work of the Group has been conducted in two phases, with the first phase report published on 26 December 2013. The Phase 1 report sets out the context, establishment, membership and terms of reference for both phases of the Groups work.  The report also outlines the legislative provisions for private health insurance in Ireland, the objectives of both phases of the review and the approach and methodology followed. Phase 2 of the process focused on the compilation and analysis by the Health Insurance Authority (HIA) of claims data to assess the cost drivers for health insurance, the effects of medical technology and innovations on costs, and claims processing issues.The report and submissions from relevant stakeholders which were examined and considered under the Phase 2 Review can be downloaded below. Download the Review of Measures to Reduce Costs in the Private Health Insurance Market 2014 -  Independent Report to the Minister for Health and Health Insurance Council here. Submissions received HSE Submission to Pat McLoughlin, Chair of Review Group IHAI submission 11 April 2014 IHCA submission to Chair 1 May 2014 Insurance Ireland submission Society of Actuaries in Ireland submission St. Patricks Mental Health Services submission April 2014 St John of Gods Submission        

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The Food Safety Promotion Board, following a request from the Minister of State at the Department of Health and Children, Dr. Tom Moffatt T.D., established the Stimulant Drinks Committee (consisting of external experts) to carry out research into the health effects of stimulant drinks. The task and terms of reference for the group were: • to review the potential health effects on the population of Ireland from the consumption of stimulant drinks • to assess the knowledge gaps • to consider the need for any action to protect public health.