Добірка наукової літератури з теми "Monoamides"

Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями

Оберіть тип джерела:

Ознайомтеся зі списками актуальних статей, книг, дисертацій, тез та інших наукових джерел на тему "Monoamides".

Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.

Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.

Статті в журналах з теми "Monoamides"

1

McCann, Kevin, Sergey I. Sinkov, Gregg J. Lumetta, and Jenifer C. Shafer. "Inner versus outer sphere metal-monoamide complexation: ramifications for tetravalent & hexavalent actinide selectivity." New Journal of Chemistry 42, no. 7 (2018): 5415–24. http://dx.doi.org/10.1039/c7nj04851c.

Повний текст джерела
Анотація:
Extraction of tetravalent and hexavalent plutonium by straight and branched chained monoamides was studied using UV-vis spectroscopy. These results suggest straight monoamides recover outer-sphere species, while branched chain monoamides recover inner-sphere species.
Стилі APA, Harvard, Vancouver, ISO та ін.
2

Canela-Xandri, Anna, Gemma Villorbina, Mercè Balcells, Xavier Fernández-Francos, Luisa F. Cabeza, and Ramon Canela-Garayoa. "Synthesis and Thermophysical Characterization of Fatty Amides for Thermal Energy Storage." Molecules 24, no. 20 (October 21, 2019): 3777. http://dx.doi.org/10.3390/molecules24203777.

Повний текст джерела
Анотація:
Nine monoamides were synthesized from carboxylic acids (C8–C18) and crude glycerol. The final monoamides were the result of a rearrangement of the acyl chain during the final hydrogenation process. The purity of the final compounds was determined by spectroscopic and mass spectrometry (MS) techniques. The thermophysical properties of solid monoamides were investigated to determine their capability to act as phase change materials (PCM) in thermal energy storage. Thermophysical properties were determined with a differential scanning calorimeter (DSC). The melting temperatures of the analyzed material ranged from 62.2 °C to 116.4 °C. The analyzed enthalpy of these monoamides ranged from 25.8 kJ/kg to 149.7 kJ/kg. Enthalpy values are analyzed considering the carbon chain and the formation of hydrogen bonds.
Стилі APA, Harvard, Vancouver, ISO та ін.
3

Sieffert, Nicolas, and Georges Wipff. "Uranyl extraction by N,N-dialkylamide ligands studied using static and dynamic DFT simulations." Dalton Transactions 44, no. 6 (2015): 2623–38. http://dx.doi.org/10.1039/c4dt02443e.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
4

Jones, R., A. G. M. Rattray, S. J. Rettig, J. R. Scheffer, and J. Trotter. "Structures and photochemistry of dibenzobarrelene monoamides." Acta Crystallographica Section B Structural Science 52, no. 6 (December 1, 1996): 1007–13. http://dx.doi.org/10.1107/s0108768196009056.

Повний текст джерела
Анотація:
The photochemistry of 9,10-ethenoanthracene-11-monoamides has been studied and correlated with the crystal structures determined for two derivatives; photoproduct structures have been established from a crystal structure analysis of one of the products and from NMR correlations. Crystal data are: (1)-Et, N, N-diethyl-9,10-dihydro-9,10-ethenoanthracene-11-carboxamide, C21H21NO, Pbca; (1)-Pr, 9,10-dihydro-N,N-di(isopropyl)-9,10-ethenoanthracene-11-carboxamide, C23H25NO, P21/c; (2 L)-Bz, 9,10-dihydro-9,10-ethenoanthracene-11-spiro-3′-(1-benzyl-4-phenylazetidine)-2′-one, C31H25NO (+ solvent), P21/a (Z = 8). The two dibenzobarrelene molecules have geometries and dimensions similar to those of related materials; the amide group in each molecule is only partially conjugated with the C 11=C 12 double bond. Mechanisms are derived for the formation of three types of photoproduct: (i) the well known di-π-methane reaction [(2M)-type photoproduct]; (ii) a hydrogen abstraction process (2H); (iii) β-lactam formation (2 L).
Стилі APA, Harvard, Vancouver, ISO та ін.
5

Pintus, Anna, M. Carla Aragoni, Gianfranco Carcangiu, Laura Giacopetti, Francesco Isaia, Vito Lippolis, Laura Maiore, Paola Meloni, and Massimiliano Arca. "Density functional theory modelling of protective agents for carbonate stones: a case study of oxalate and oxamate inorganic salts." New Journal of Chemistry 42, no. 14 (2018): 11593–600. http://dx.doi.org/10.1039/c8nj01714j.

Повний текст джерела
Анотація:
DFT calculations allowed investigating the ability of oxalate monoesters and monoamides salts to act as protective agents for carbonate stones, such as marble or limestones, of historical interest in the field of cultural heritage.
Стилі APA, Harvard, Vancouver, ISO та ін.
6

Fischer, Róbert, and Mária Fišerová. "Direct synthesis of furan-2,5-dicarboxylic acid monoamides." Arkivoc 2015, no. 7 (September 16, 2015): 113–21. http://dx.doi.org/10.3998/ark.5550190.p009.239.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
7

Valerio-Alfaro, Gerardo, Patricia Harumi Castillo-Carrasco, Olaya Pirene Castellanos Onorio, and Jorge Bautista Naranjos. "Highly Efficient Lipase Catalyzed Monoaminolysis Reaction of Diesters with Benzylamine." Natural Product Communications 14, no. 6 (June 2019): 1934578X1985998. http://dx.doi.org/10.1177/1934578x19859980.

Повний текст джерела
Анотація:
Preparation of amides by biocatalyzed aminolysis reactions has greatly increased because these processes play an important role in the preparation of some pharmaceutical products and their intermediates. A highly efficient synthesis of malonic (5), succinic (6), and malic (8) monoamide esters by desymmetrization transformations (mono aminolysis reactions) of their diesters is presented. The immobilized lipase from Candida antarctica (CaL-B, Novozym 435) catalyzed the mono aminolysis of bifunctional compounds: diesters such as diethyl malonate (1), diethyl succinate (2), and ( R, S)-malate (3), leading to their corresponding monoamides (5), (6), and (8), respectively, with high conversions after a 24 hour reaction in the presence of an organic solvent. Increasing the solvent polarity from toluene, methyl t-butyl ether to dioxane led to an improved conversion. According to qualitative and quantitative GC-MS analysis, conversions of diesters (1), (2), and (3) into their mono amide esters were in the range 65%-97%. CaL-B was the best biocatalyst of the commercial lipases used, including those from Candida rugosa, Rhizomucor miehei, Carica papaya, and Pseudomonas cepacia. Likewise, a yield of 91% regioisomeric, but virtually racemic ( R,S)-mono amide (8) was obtained as the single product in dioxane.
Стилі APA, Harvard, Vancouver, ISO та ін.
8

Giroux, Se´bastien, Patrice Rubini, Christine Ge´rardin, Claude Selve, and Bernard Henry. "Hydrophobic tartaric acid monoamides as complexing and tensioactive agents." New Journal of Chemistry 24, no. 3 (2000): 173–78. http://dx.doi.org/10.1039/a909430j.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
9

Klimenkovs, Igors, Eduards Bakis, and Anda Priksane. "Propanephosphonic Acid Anhydride–Mediated Cyclodehydration of Maleic Acid Monoamides." Synthetic Communications 43, no. 19 (June 26, 2013): 2634–40. http://dx.doi.org/10.1080/00397911.2012.727060.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
10

Wauke, Hisashi, Kazumasa Matsuo, Kenji Matsumoto, and Mitsuru Shindo. "Synthesis of Dissymmetric Malonic Acid Monoamides from Symmetric Dithiomalonates." ChemistrySelect 1, no. 21 (December 16, 2016): 6830–33. http://dx.doi.org/10.1002/slct.201601694.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.

Дисертації з теми "Monoamides"

1

Ferru, Geoffroy. "Spéciation moléculaire et supramoléculaire des systèmes extractants à base de monoamides." Paris 6, 2012. http://www.theses.fr/2012PA066612.

Повний текст джерела
Анотація:
Le DEHiBA a été retenu comme extractant sélectif de l'uranium lors de la première étape du procédé GANEX, procédé ayant pour but de réaliser l'extraction groupée des actinides lors d'une seconde étape. L'objectif de ces travaux de thèse est d'améliorer la description des phases organiques de monoamides dans les alcanes après extraction de solutés. Une étude paramétrique a alors été entreprise, visant à étudier séparément l'extraction d'eau, d'acide nitrique et de nitrate d'uranyle, à l'échelle moléculaire et à l'échelle supramoléculaire. L'étude de l'organisation supramoléculaire des solutions a permis de distinguer trois régimes : Pour des concentrations d'extractant inférieures à 0,5 mol/L, les espèces monomères sont majoritaires, quel que soit le soluté extrait. Pour des concentrations comprises entre 0,5 et 1 mol/L, de petits agrégats sont formés. Après extraction d'eau et d'acide nitrique, il s'agit essentiellement de dimères. L'extraction de nitrate d'uranyle engendre la formation d'objets légèrement plus gros, contenant 2 à 4 molécules de monoamide. Pour les phases plus concentrées (supérieures à 1 mol/L), des espèces contenant 2 ou 4 molécules de monoamides se formeraient après extraction d'eau ou d'acide nitrique. Concernant l'extraction de nitrate d'uranyle, une très importante structuration des phases organiques est observée, ne permettant plus de considérer la formation d'agrégats "sphériques" bien définis. D'un point de vue moléculaire, les complexes sont peu sensibles à l'organisation de la solution : les mêmes espèces sont observées, quelles que soient la concentration de l'uranyle et d'extractant en phase organique
The DEHiBA was chosen as extractant for the selective recovery of uranium in the GANEX process first cycle, which aims to realise the grouped extraction of actinides in a second step. The object of this work is to improve the description of monoamide organic phases in alkanes after solutes extraction. A parametric study was undertaken to study singly water, nitric acid and uranyl nitrate extraction at the molecular and supramolecular scale. The study of the organization has allowed identifying three regimes: For extractant concentration less than 0. 5 mol/L, monomeric species are majority, whatever the solute. For extractant concentration between 0. 5 and 1 mol/L, small aggregates are formed: after water and nitric acid extraction, this is essentially dimers. Uranyl nitrate extraction generates bigger objects, containing 2 to 4 molecules of monoamide. For more concentrated phases (more than 1 mol/L), species containing 2 to 4 molecules of monoamides could be formed after water or nitric nitric extraction. Concerning uranyl nitrate extraction, an important and strong organization of the organic phase is observed, which no longer allowing considering the formation of spherical well defined aggregates. From the molecular view, complexes are not sensitive to the organization of the solution: same species are observed, whatever the concentration of uranyl and of extractant in organic phase
Стилі APA, Harvard, Vancouver, ISO та ін.
2

Amoudji, Amivi Eméfa Félicité. "Comportement électrochimique du cérium et du plutonium dans les milieux organiques extractants monoamides." Electronic Thesis or Diss., Montpellier, Ecole nationale supérieure de chimie, 2022. http://www.theses.fr/2022ENCM0009.

Повний текст джерела
Анотація:
Les monoamides sont étudiés depuis quelques années comme extractants alternatifs au TBP dans le procédé de retraitement du combustible irradié. Ces molécules possèdent une affinité modulable pour le plutonium(IV), selon la nature de leur chaîne alkyle et selon l’acidité. Comme le TBP, les monoamides, solvants immiscibles extraient de l’eau et de l’acide nitrique lorsqu’ils sont mis en contact avec ce dernier. L’acide nitrique étant un composé instable vis-à-vis de la radiolyse, il dismute en plusieurs composés azotés dont l’acide nitreux (HNO2) qui par sa présence pourrait entrainer la formation du couple redox HNO3/HNO2 susceptible de provoquer des réactions redox parasites et perturber le procédé. Il est donc important de connaitre la spéciation redox des actinides (An) en particulier dans la phase organique d’extraction afin d’assurer une bonne maitrise du procédé.Le comportement électrochimique du couple Ce(IV)/Ce(III) a été étudié par voltampérométrie cyclique à 25 et 40°C à une électrode de carbone vitreux dans trois N,N-dialkylamides : le DEHBA (N,N-di-(2-éthylhexyl)-n-butanamide), le DEHiBA (N,N-di-(2- éthylhexyl)-iso-butanamide) et le DEHDMBA (N,N-di-(2-éthylhexyl)-3,3- diméthyl-n-butanamide) pré-équilibrés à l’eau et à l’acide nitrique (HNO3 5M). Les résultats ont montré que le processus électrochimique du couple Ce(IV)/Ce(III) est celui d’un couple redox quasi-rapide limité par la diffusion. Cette étude préalable sur le cérium analogue chimique non radioactif du plutonium a été réalisée dans le but d’identifier la nature du système électrochimique du couple Ce(IV)/Ce(III) et les difficultés liées à la réalisation de mesures électrochimiques dans ces milieux organiques très visqueux et très peu conducteurs. Le couple redox Pu(IV)/Pu(III) a ensuite été étudié à 40°C dans le DEHBA à une électrode de carbone vitreux à différentes concentrations d’acide nitrique (0,6 M < [HNO3]org < 3,7 M). Une étude préalable de la spéciation du plutonium (IV) dans la phase organique DEHBA après extraction a révélé la formation de deux types de complexes avec les ligands DEHBA et dont la prépondérance dans le milieu organique varie avec l’acidité. Les mesures de voltampérométrie cyclique ont montré que la nature des complexes de plutonium dans le DEHBA peut avoir un impact notable sur l’électroactivité du couple redox Pu(IV)/Pu(III). Il a été observé aux faibles acidités en phase organique que le processus électrochimique du couple redox Pu(IV)/Pu(III) est celui d’un couple quasi-rapide limité par la diffusion. Aucune électroactivité du couple Pu(IV)/Pu(III) n’a été observée aux fortes acidités.Cette étude a permis de déterminer les caractéristiques physico-chimiques des couples redox Ce(IV)/Ce(III) et Pu(IV)/Pu(III) tels que le potentiels redox et le coefficient de diffusion dans les milieux N,N-dialkylamides ; des données qui jusque-là, sont quasi-inexistantes dans la littérature. À l’issu de cette étude, une méthode permettant le dosage par voltampérométrie cyclique de cations métalliques en milieu organique a été élaborée
Monoamides extractants are being studied in recent years as alternate extractants to TBP for irradiated nuclear fuels reprocessing. Their extracting strength and selectivity toward Pu(IV) can be tuned depending on the nature of their alkyl chain and the nitric acid concentration. Like TBP, monoamides can extract water and nitric acid while in contact. However, nitric acid is unstable in both aqueous and organic phases. Due to radiolysis, it can be disproportionate in nitrous acid (HNO2) which is known to possess redox properties. It could lead to the formation of the HNO3/HNO2 redox couple which may cause several parasitic redox reactions and affect the recycling process. Meaningful the redox speciation of actinides (An) in an organic phase is important for acute control of the recycling processes. The electrochemical behavior of the Ce(IV)/Ce(III) couple have been studied at 25 and 40°C by cyclic voltammetry at a vitreous carbon working electrode in three N,N-dialkylamides solvents (DEHBA (N,N-di-(2-ethylhexyl)-n-butanamide), DEHiBA (N,N-di-(2-ethylhexyl)-iso-butanamide) and DEHDMBA (N,N-di-(2-ethylhexyl-)3,3-dimethylbutanamide)) pre-equilibrated with aqueous nitric acid solutions (HNO3 5M). Results showed that the Ce(IV)/Ce(III) redox process exhibits a well-defined reversible couple with a diffusion-controlled electrochemical behavior. This initial study on the Ce(IV)/Ce(III) couple, a "non-radioactive model" of the Pu(IV)/Pu(III) couple has been an entry to the direct electrochemical characterization of plutonium in these extractants aiming to identify the nature of the electrochemical process of the Ce(IV)/Ce(III) couple and the difficulties associated with carrying out electrochemical measurements in these viscous and low conductive media. The Pu(IV)/Pu(III) couple has been studied at 40°C in DEHBA at a vitreous carbon working electrode at different concentrations of nitric acid (0,6 M < [HNO3]org < 3,7 M). The study of the speciation of plutonium (IV) in the organic DEHBA phase after extraction showed the presence of two types of plutonium(IV) complexes with variable predominance due to the nitric acid concentration. Cyclic voltammetry measurements showed an significant effect of the speciation of plutonium in the organic phase on the electroactivity of the Pu(IV)/Pu(III) couple. At low nitric acid concentrations, the Pu(IV)/Pu(III) redox process exhibits a well-defined reversible couple with a diffusion-controlled electrochemical behavior. At higher nitric acid concentrations, no electrochemical response of the Pu(IV)/Pu(III) couple is observed. This study enabled the determination of physic and chemical characteristics of the Ce(IV)/Ce(III) and Pu(IV)/Pu(III) couples in N,N-dialkylamides media as the redox potential and the diffusion coefficient that were not previously studied. This study validates the implementation of electrochemical method for the quantification of tetravalent metallic cation in organic phases
Стилі APA, Harvard, Vancouver, ISO та ін.
3

Berlemont, Romain. "Etude cinétique d'extraction de l'uranium(VI) et du plutonium(IV) par des extractants monoamides." Thesis, Paris 6, 2015. http://www.theses.fr/2015PA066320/document.

Повний текст джерела
Анотація:
Ces travaux de thèse, effectués dans le cadre des études sur le retraitement des combustibles nucléaires usés par extraction-liquide-liquide, concernent l’étude cinétique d’extraction de l’uranium(VI) et du plutonium(IV) en milieu acide nitrique par un mélange d’extractants de type monoamide. Trois techniques ont été utilisées pour étudier les cinétiques d’extraction et identifier les régimes de transfert : la méthode de la goutte unique, la cellule d’extraction de Nitsch et la cellule à membrane tournante (RMC). Les résultats obtenus avec la goutte unique indiquent que les cinétiques de transfert d’U(VI) et Pu(IV) sont proches. Une étude hydrodynamique des gouttes et la modélisation du transfert de l’U(VI) ont montré que la présence d’une circulation interne à la goutte diminue les résistances diffusionnelles pour des tailles de goutte croissantes. L’influence de la concentration d’U(VI) dans le solvant sur la cinétique d’extraction a montré que le transfert d’U(VI) et Pu(IV) ralentit lorsque la concentration d’U(VI) en phase organique et la viscosité augmentent. L’ensemble de ces résultats couplé à l’étude du transfert de l’U(VI) par la cellule de Nitsch conduisent à supposer une cinétique gouvernée par la diffusion principalement localisée dans la phase organique. Les études réalisées avec la RMC ont permis de déterminer la constante chimique d’extraction de l’U(VI), du même ordre de grandeur que les cinétiques obtenues par la goutte unique et de confirmer la présence d’une réaction chimique interfaciale. Enfin, le transfert d’U(VI) et Pu(IV) s’avère 3 fois plus lent que celui par le TBP mais reste adapté pour un procédé d’extraction à l’échelle industrielle
This thesis was conducted in the framework of the reprocessing of spent nuclear fuels. The kinetics extraction of uranium(VI) and plutonium(IV) by N,N-dialkylamides or monoamides in an aliphatic diluent were studied from an aqueous nitric solution using 3 different techniques: “single drop technique”, Nitsch cell and Rotating Membrane Cell (RMC). All these experiments were useful to attempt the identification of the transfer process between the phases which can be controlled by kinetic or diffusional regime. The kinetics of extraction of U(VI) by monoamides solvent seems to be similar to that of the Pu(IV). In general, molecular diffusion in organic phase slows down the extraction process and the limiting thickness of organic phase increases with solvent viscosity. The process in “single drop technique” seems to be controlled not only by diffusion but also by the chemical reaction. Then the extraction kinetics of U(VI) has been carried out by Nitsch cell and the RMC. Diffusionnal regime is the limiting step in Nitsch cell and the results confirm that molecular diffusion in organic phase should mainly control the kinetics transfer. Then experiments performed by the RMC indicate that the kinetics is in the same order as transfer coefficient obtained by “single drop” and the chemical reaction occurs at the interface. Finally, these results were compared with data obtained with a TBP solvent (tributyl phosphate) currently used in the PUREX process in order to estimate the interest of such a new solvent. The kinetics of extraction of U(VI) by this monoamide-based solvent is three times lower that of the TBP 30 % but remains fast and suitable for a future industrial process
Стилі APA, Harvard, Vancouver, ISO та ін.
4

Ribokaite, Kristina. "Etude théorique et expérimentale de complexes d’actinides avec des ligands monoamides et organophosphorés en solution." Paris 6, 2013. http://www.theses.fr/2013PA066458.

Повний текст джерела
Анотація:
Les ligands oxygénés de type monoamides et organophosphorés sont d’un grand intérêt pour le cycle du combustible nucléaire. Ils peuvent permettre d’extraire sélectivement par des procédés d’extraction liquide-liquide certains actinides. La structure de l’extractant, caractérisé par son groupe fonctionnel permettant l’extraction ainsi que par ses substituants alkyles, a un rôle prédominant sur l’extraction sélective des actinides. Ces travaux de thèse concernent l’étude théorique et expérimentale de systèmes modèles afin de mieux comprendre l’effet de la structure de l’extractant sur les structures moléculaires des complexes formés. Ainsi les structures de complexes d’actinides en présence de ligands modèles et dans des milieux simples (eau ou méthanol en présence d’ions nitrate) ont été caractérisées. Des simulations de dynamique moléculaire et des calculs DFT ont permis de quantifier la stabilité des complexes d’uranyle avec des ligands monoamide et oxyde de phosphine et de déterminer leurs propriétés structurales. Les résultats théoriques ont ensuite été confrontés à des résultats expérimentaux obtenus par spectroscopies UV-visible, Infra Rouge, Raman et EXAFS sur des systèmes chimiques identiques. Ensuite, les mesures spectroscopiques associées à la modélisation moléculaire ont permis d’acquérir une meilleure connaissance sur le mode de coordination d’un ion nitrate autour de l’uranyle dans l’eau et le méthanol. Enfin, des calculs DFT ont permis d’étudier l’influence de la structure du ligand monoamide ou organophosphoré sur son interaction avec les actinides (IV, VI) en quantifiant notamment les effets d’encombrement en première sphère de coordination
Monoamides and organophosphate are of great interest for the nuclear fuel cycle. Such ligands can selectively extract actinides in liquid-liquid extraction processes. The structure of the extractant (its functional group and its alkyl substituents) has a predominant role in the selective separation of actinides. This thesis concerns the theoretical and experimental studies of model systems in the aim of better understanding of the effect on molecular structures of the complexes. Structures of actinides complexes formed with model ligands in simple media (water or methanol in the presence of nitrate ions) have been characterized. At first, the complexation of uranyl by monoamide and phosphine oxide was studied in water and methanol. Molecular Dynamics simulations and DFT calculations were used to quantify the stability of uranyl complexes with those ligands, and to determine their structural properties. The theoretical results were then compared with experimental results obtained by UV-visible, infrared, Raman and EXAFS on the same chemical systems. The results were used to highlight the greater stability of uranyl complexes with phosphine oxide and monoamides. Further spectroscopic measurements combined with molecular modeling were used to gain a better understanding of the coordination mode of nitrate ion around the uranyl in both water and methanol. Finally, DFT calculations were used to study the influence of the structure of the monoamide or organophosphorus ligand and their interaction with the actinides (IV, VI) including steric effects in the first coordination sphere
Стилі APA, Harvard, Vancouver, ISO та ін.
5

Lopes, Moreira Sandra. "Synthèse et évaluation de nouveaux monoamides pour l’extraction de l’uranium(VI) et du plutonium(IV)." Nantes, 2013. https://archive.bu.univ-nantes.fr/pollux/show/show?id=7b1d6f98-ec99-4912-92b1-57de201f818d.

Повний текст джерела
Анотація:
Ces travaux de thèse, effectués dans le cadre des études sur le retraitement des combustibles nucléaires usés par extraction liquide-liquide, concernent la synthèse et l'évaluation de nouveaux monoamides pour étudier l'influence des groupements portés par la fonction amide sur l'extraction de l'uranium(VI) et du plutonium(IV) en milieu acide nitrique. Dans ce contexte, quarante-deux nouveaux monoamides, comportant des modifications soit du côté carbonyle soit du côté de l'atome d'azote, ont été synthétisés. Ces monoamides ont été conçus dans l'intention d'établir une relation entre la structure des monoamides et leur affinité et sélectivité vis-à-vis de l'U(VI) et Pu(IV). Des tests d'extraction ont été réalisés à 4M et 0,5M HN03 afin d'estimer les coefficients de distribution et la sélectivité U(VI)/Pu(IV). Les résultats ont confirmé l'influence des ramifications en a ou ß du carbonyle pour la sélectivité U/Pu, et ont également montré l'importance de la ramification des chaines azotées. Le comportement singulier des monoamides comportant des chaines dissymétriques sur l'atome d'azote vis-à-vis de l'extraction du Pu(IV) a permis de concevoir une molécule plus performante que la molécule de référence. Enfin, des études complémentaires sur deux ligands pertinents ont été menées pour déterminer la stœchiométrie des complexes actinides-ligand formés en phase organique, et pour évaluer le potentiel d'une molécule dans des conditions proches de celles du procédé
This thesis, conducted in the framework of the reprocessing of spent nuclear fuels, concerns the design and evaluation of new monoamides to study the influence of the branched alkyl groups grafted on the amide function on uranium (VI) and plutonium (IV) extraction. Forty two new monoamides, with modifications on carbonyl side or on the nitrogen atom side, were synthesized. These monoamides were designed in order to establish a relationship between the monoamide structure and its affinity and selectivity relatively towards U(VI) and Pu(IV). Liquid-liquid extraction tests were systematically performed with these ligands at 4M and 0,5M HN03 in order to measure the distribution ratios and the U(VI)/Pu(IV) selectivity. The results confirmed the strong influence of the steric hindrance due to branched alkyl groups on the carbonyl side on the U(VI)/Pu(IV) selectivity but have also shown the importance of the steric hindrance on the nitrogen side. The single behaviour of the unsymmetrical monoamides observed for Pu(IV) extraction allowed the design a new molecule with higher performances than the reference monoamide. Finally, extractions isotherms on two relevant ligands were performed in order to determine the stoichiometry of the actinide-ligands complexes formed in organic phase and to assess the performances of this new ligand in process conditions
Стилі APA, Harvard, Vancouver, ISO та ін.
6

Moeyaert, Pauline. "Etude expérimentale et modélisation des mécanismes d’extraction des produits de fission et des actinides mineurs par des extractants de la classe des monoamides." Thesis, Montpellier, 2016. http://www.theses.fr/2016MONTT199.

Повний текст джерела
Анотація:
Le procédé PUREX utilise comme molécule extractante le tri-butyl-phosphate (TBP) pour assurer l’extraction et la purification de l’uranium et du plutonium des combustibles nucléaires usés. Bien que le retour d’expérience industriel soit très positif, des améliorations de ce procédé sont possibles notamment pour le futur traitement de combustibles plus riches en plutonium. Les extractants de la famille des N,N-dialkylamides (monoamides) ont montré par le passé une potentialité avérée pour remplacer le TBP : ils permettent de co-extraire l’uranium et le plutonium puis de dés-extraire sélectivement le plutonium par une diminution de l’acidité du milieu, supprimant ainsi les opérations de réduction du plutonium consommatrices en réactif potentiellement toxique (hydrazine). Le travail de recherche mené au cours de cette thèse vise à comprendre et modéliser l’extraction de certains produits de fission et actinides mineurs : césium, europium, américium, ruthénium et technétium, éléments qui ne doivent pas contaminer les matières recyclées. Les systèmes extractants choisis pour l’étude sont constitués des monoamides N,N-di (éthyl-2 hexyl) butanamide (DEHBA), N,N-di (éthyl-2 hexyl) isobutanamide (DEHiBA), du mélange de ces deux monoamides, de N-méthyl-N-octyl-(2-ethyl)hexanamide (MOEHA) et de TBP, extractant actuellement utilisé à l’usine AREVA de La Hague, dilués dans le tétrapropylène hydrogéné (TPH). Pour y parvenir, une démarche multi-échelle a été mise en place avec l’acquisition de données de distribution et de données thermodynamiques. Ces données ont servi de support pour élaborer des modèles permettant de simuler le comportement des différents éléments dans les cycles d’extraction actuel ou futur. En parallèle et lorsque les conditions chimiques des systèmes le permettaient, des études de spéciation des phases organiques ont été entreprises, afin d’obtenir des informations sur la stœchiométrie des complexes formés et sur les mécanismes mis en jeu au cours de l’extraction.De ces travaux peuvent se dégager un certain nombre de conclusions :- l’extraction des nitrates de césium, d’europium et d’américium par les monoamides est très faible et a pu être correctement modélisée,- l’extraction du technétium par les monoamides semble répondre au même mécanisme que dans le cas du TBP : le technétium est principalement co-extrait en phase organique en formant des complexes mixtes avec l’uranium. En effet, un anion pertechnétate se substitue à un anion nitrate dans les complexes formés entre l’extractant et le nitrate d’uranyle, selon un mode de coordination monodenté, conduisant à une extraction exacerbée du technétium. La modélisation de l’extraction du technétium par les monoamides a pu être améliorée en reconsidérant l’estimation des écarts à l’idéalité en phase aqueuse avec une nouvelle variation du coefficient d’activité de l’acide pertechnétique en solution binaire dans l’eau,- avec les monoamides comme avec le TBP, le ruthénium est faiblement extrait en phase organique mais cette fraction extraite, aussi faible soit elle, constitue une contamination résiduelle du solvant. Les données acquises, grâce à la mise au point d’un protocole de préparation de solutions simulées, sont représentatives du comportement du ruthénium dans les conditions d’extraction des procédés. Les modèles développés permettent de très bien reproduire le comportement du ruthénium dans les opérations d’extraction de procédés mis en œuvre à l’échelle pilote, sur des solutions de dissolution réelles,- une approche nouvelle pour le calcul des coefficients d’activité en phase organique a été développée. Elle explicite les écarts à l’idéalité liés à l’association en phase organique via les équilibres de complexation, mais aussi, et pour la première fois, les effets liés à la répulsion entre espèces en les considérant comme des sphères dures
The PUREX process is a solvent extraction method dedicated to the reprocessing of irradiated nuclear fuel in order to selectively extract uranium(VI) and plutonium(IV) from fission products and minor actinides. The tri-n-butylphosphate (TBP) is used as the extractant in the organic phase. Within the frame of the development of Generation IV reactors, new liquid-liquid extraction processes are under development for the reprocessing of spent nuclear fuels. The N,N-dialkylamides (monoamides) already showed their potentiality as promising alternative extractant to TBP for nuclear fuel reprocessing: they are able to extract U(VI) and Pu(IV) selectively by adjusting the nitric acid concentration without using Pu(IV) reducing agents. This study aims at understanding and modeling the extraction of some fission products and minor actinides: cesium, europium, americium, ruthenium and technetium, which may occur as impurities in the organic phase. In the present study, the extraction properties of N,N-di (ethyl-2 hexyl) butanamide (DEHBA), N,N-di (ethyl-2 hexyl) isobutanamide (DEHiBA), as well as a mixture of these two monoamides, N-methyl-N-octyl-(2-ethyl)hexanamide (MOEHA) and TBP, the extractant currently used in the PUREX process at the La Hague plant, diluted in TPH, were studied. For that purpose, a multi-scale approach has been used to describe the extraction mechanisms combining two different descriptions. Distribution and thermodynamic data were first determined from batch experiments. Based on these data, thermodynamic models were developed and are able to predict the behaviour of the different elements in current or future processes. Dedicated methods were also performed to obtain information about the stoichiometry of the extracted species and about the mechanisms involved during the extraction step.The main conclusions that can be deduced from this study are:- even if the extraction of cesium, europium and americium nitrates with monoamides is very low, models have been developed and fit the experimental data with good agreement,- the same mechanism may be involved in the extraction of technetium with TBP or monoamides: technetium is preferentially co-extracted in organic phase as mixed uranium-technetium species. Indeed, one TcO4- anion replaces one NO3- ion in a monodentate coordination mode in the uranium-monoamide complex. The developed thermodynamic models, that have been improved by taking into account a new variation of the pertechnetic acid activity coefficient in binary solution, fit very well the experimental data,- with monoamides as with TBP, ruthenium is poorly extracted but remains troublesome in the spent fuel reprocessing industry because of its retention in the irradiated solvent. Distribution data have first been determined from batch experiments thanks to the development of a new methodology for simulated ruthenium spent fuel dissolution solutions preparation. The developed thermodynamic models fit very well the batch experimental data. Thus, they was then used to simulate ruthenium behaviour in counter-current hot tests performed in mixer-settlers- a new approach for the activity coefficient calculation in organic phase has been developed. The MSA theory (Mean Spherical Approximation) was chosen for this purpose to explicitly describe both association and repulsive forces.Finally, this work that includes a macroscopic study (distribution and thermodynamic data acquisition and modeling) and molecular investigations (ESI-MS, FT-IR and X-ray absorption analysis supported by theoretical calculations) provides a new insight in the description of solvent extraction mechanism
Стилі APA, Harvard, Vancouver, ISO та ін.
7

Rabbe, Catherine. "Apport de la modélisation moléculaire et des relations structure-activité à l'extraction liquide-liquide. Application au cas de l'extraction d'U(VI) par les monoamides." Rouen, 1996. http://www.theses.fr/1996ROUES028.

Повний текст джерела
Анотація:
La modélisation moléculaire a été utilisée dans le domaine de l'extraction liquide-liquide de l'uranium (VI) par les monoamides à partir d'un milieu nitrique. Trois types de paramètres importants à étudier ont été identifiés : la réactivité des atomes du site de coordination, l'encombrement stérique et la lipophilie des ligands. L'objectif est, par les méthodes de la modélisation moléculaire, de calculer les paramètres mentionnés plus haut et d'établir des relations entre la structure moléculaire de l'extractant ou de son complexe formé avec le cation métallique et ses propriétés extractantes. Une base expérimentale de 22 N, N-dialkylamides a été sélectionnée. Tout d'abord, les méthodes semi-empiriques de la chimie quantique ont été utilisées afin de calculer les structures des monoamides et les propriétés physico-chimiques correspondantes. La somme des charges des atomes au voisinage du site réactif a pu être reliée au coefficient de distribution de l'uranium. Puis les outils de la mécanique moléculaire ont été utilisés pour calculer la structure des complexes UO2(NO3)2(amide)2 formés. Après une étape préliminaire de paramétrisation du champ de force pour traiter U(VI), le calcul de 22 structures de complexes nitrate d'uranyle - monoamides a été réalisé. Une relation a été montrée entre le coefficient de distribution d'U(VI) et la composante stérique de l'énergie d'association du complexe (i. E. La différence entre l'énergie du complexe et celle des espèces prises séparément). Enfin, un modèle prédictif de la capacité à extraire U(VI) a été établi pour 19 molécules de la base de données expérimentales (N,N-diakylamides). Ce modèle permet de prévoir le coefficient de distribution d'U(VI) à partir des paramètres électronique (calculé en chimie quantique) et stérique (calculé en mécanique moléculaire). Il a été montré que, dans ce cas, la lipophilie des ligands n'est pas un facteur déterminant.
Стилі APA, Harvard, Vancouver, ISO та ін.
8

Rabbe, Catherine. "Apport de la modélisation moléculaire et des relations structure-activité à l'extraction liquide-liquide : application au cas de l'extraction d'U(VI) par les monoamides /." Gif-sur-Yvette : Direction de l'information scientifique et technique, CEA Saclay, 1996. http://catalogue.bnf.fr/ark:/12148/cb369615416.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
9

CitÃ, Maria do Carmo de Oliveira. "AlteraÃÃes comportamentais e neuroquÃmicas provocadas por diferentes perÃodos de retirada apÃs tratamento subcrÃnico com cocaÃna em ratos: envolvimento dos sistemas dopaminÃrgico, serotonÃrgico e noradrenÃrgico." Universidade Federal do CearÃ, 2009. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=3986.

Повний текст джерела
Анотація:
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior
A cocaÃna à uma droga consumida mundialmente e considerada hoje como um problema de saÃde pÃblica. Uma das principais dificuldades enfrentadas no combate ao vÃcio da cocaÃna, na maioria dos casos, està relacionada aos sintomas de abstinÃncia da droga, como ansiedade, depressÃo, irritabilidade, fadiga e insÃnia, fazendo com que o indivÃduo volte a procurÃ-la. Para avaliar as alteraÃÃes comportamentais (ansiedade e depressÃo) e neuroquÃmicas, os ratos foram submetidos Ãs retiradas de 24 h, 7 d e 21 d apÃs o tratamento subcrÃnico por 7 dias com cocaÃna (20mg/kg), sendo realizados os modelos experimentais de Labirinto de Cruz Elevado (LCE), Campo Aberto (CA) e Nado ForÃado (NF). AlÃm disso, na abstinÃncia de 24h foram testados o propranolol (10mg/kg, i.p.), o ondansetrom (4mg/kg, i.p) e a buspirona (5 mg/kg, i.p.), no LCE e CA, bem como na abstinÃncia de 21 d foram testados a bupropiona (30mg/kg, i.p.) e paroxetina (10 mg/kg, i.p.) no NF, com o intuito de reverter tais alteraÃÃes comportamentais provocadas pela retirada forÃada do tratamento subcrÃnico com cocaÃna. Para o estudo neuroquÃmico (neuroadaptaÃÃo) foi utlizado o corpo estriado (CE) de ratos, avaliando-se os seguintes parÃmetros: nÃveis de monoaminas (NA, DA, 5-HT) e seus metabÃlitos (DOPAC, HVA e 5-HIAA) atravÃs do HPLC com detecÃÃo eletroquÃmica e a atividade da enzima catalase. Na avaliaÃÃo da ansiedade, os resultados mostraram que no LCE houve uma reduÃÃo do NEBA, PEBA, TPBA e PTBA na abstinÃncia de 24h e 7 d, apÃs 21d nÃo houve alteraÃÃo. No CA, as retiradas de 24h e 7 d promoveram um aumento da atividade locomotora do animal, no entanto na retirada de 21 d ocorreu uma diminuiÃÃo da atividade locomotora. Na abstinÃncia de 24h foram administrados propranolol, ondansetrom e buspirona. No LCE, o propranolol aumentou o NEBA e reduziu o PTBA, enquanto que o ondansetrom aumentou o NEBA, PEBA, TPBA e o PTBA em relaÃÃo ao grupo da cocaÃna. Jà a buspirona em relaÃÃo à cocaÃna aumentou o PTBA, TPBA e o PEBA, porÃm o NEBA foi reduzido. Enquanto que no CA, o propranolol, o ondansetrom e a buspirona reduziram a atividade locomotora em relaÃÃo ao grupo da cocaÃna. Para avaliar a atividade antidepressiva foi realizado o teste do nado forÃado, no qual as retiradas de 24h e 7 d reduziram o tempo de imobilidade, contudo na abstinÃncia de 21 d houve um aumento do parÃmetro avaliado. Na abstinÃncia de 21 d foram administrados paroxetina e bupropiona, verificando uma reduÃÃo do tempo de imobilidade em relaÃÃo ao grupo da cocaÃna. Para a realizaÃÃo dos estudos neuroquÃmicos, os animais foram dissecados para retirada do CE. No corpo estriado observou-se um aumento de dopamina (DA) e uma reduÃÃo de seus metabÃlitos (DOPAC e HVA) nas trÃs retiradas. A concentraÃÃo de serotonina aumentou nas trÃs retiradas, entretanto o seu metabÃlito (5HIAA) aumentou somente nas retiradas de 24h e 7d. Jà a noradrenalina reduziu apÃs as trÃs retiradas. Em relaÃÃo aos receptores, no corpo estriado D2 encontrava-se elevado em 24h e 7d, jà 5HT2 apÃs 7d e D1 nÃo foi alterado. Foi tambÃm avaliado no CE a atividade da catalase, enzima antioxidante, que mostrou uma reduÃÃo de sua atividade nas trÃs retiradas. Os resultados sugerem que diferentes perÃodos de retirada apÃs tratamento subcrÃnico com cocaÃna causam efeitos ansiogÃnicos e depressores sobre o SNC e tais efeitos foram revertidos por propranolol, ondansetrom, buspirona, bupropiona e paroxetina. O estudo neuroquÃmico mostrou que a abstinÃncia de cocaÃna sÃo eventos multimediados e que CE tem uma importante participaÃÃo, estando tambÃm a atividade da catalase envolvida neste processo. Estes achados sÃo importantes para a investigaÃÃo de novos tratamentos para a sÃndrome de abstinÃncia de cocaÃna.
Cocaine is world used and considered as a public health problem, being the relapse one of the hardly difficulties faced by cocaine users, that in the most cases, is related to abstinence symptoms, like anxiety, depression, irritability, fatigue and sleeplessness. To evaluate the behavioral alterations (anxiety and depression) and neurochemistry, rats were submitted to 24h, 7 d and 21 d withdrawal, after the subcronic treatment, for 7 days with cocaine (20mg/kg), being realized the experimental models of Elevated Plus Maze (EPM), Open Field (OF) and Forced Swimming (FS). Moreover, in the 24h abstinence, propranolol (10mg/kg, i.p.), ondansetrom (4mg/kg, i.p) and buspirone (5 mg/kg, i.p.) had been tested, in the EPM and OF, as wel as in the 21 d of abstinence bupropione (30mg/kg, i.p.) and paroxetine (10 mg/kg, i.p.) had been tested in the FS, aiming to revert the alterations caused by the abstinence of cocaine subcronic administration. For the neurochemistry study (neuroadaptation) was used striatum (ST) of rats, evaluating the following parameters: level of monoamines (NE, DA and 5HT) and its metabolites (DOPAC, HVA and 5HIAA), using the electrochemistry detection HPLC and the activity of the catalase enzyme. In the anxiety evaluation, results showed that in the EPM there was a reduction on NEOA, PEOA, TPOA and PTOA in the abstinence of 24h, 7 d and 21 d. In the OF, the withdrawal of 24 and 7 d promoted an increasing in the locomotor activity of animals, while the withdrawal of 21 d a decreasing in the locomotor activity was observed. In the 24h abstinence were administered propranolol, ondansetrom and buspirone. In the EPM, propranolol increased NEOA and reduced PTOA, while ondansetrom increased NEOA, PEOA, TPOA and PTOA, as compared to cocaine group. In addition buspirone as compared to cocaine group increased PTOA, TPOA, and PEOA, however NEOA was reduced. While in the OF, propranolol, ondansetron and buspirone reduced the locomotor activity as related to cocaine group. To evaluate the antidepressive effect the FS was performed, where the withdrawal of 24h and 7 d reduced the immobility time, although in the 21 d abstinence an increase of this parameter was observed. In the 21 d abstinence had been administered paroxetine and buproprione, verifying a reduction of the immobility time as related to cocaine group. To the performance of neurochemistry studies, animals were dissected to take off the ST. In the ST was observed an increasing of dopamine (DA) and a reduction of its metabolites (DOPAC and HVA) in the three withdrawals. The serotonine levels increased the three withdrawals, however its metabolite (5HIAA) increased only in the 24h and 7 d withdrawals. In addition norepinephrine reduced after the 24h, 7 d and 21 d withdrawal. In relation to the receptors, in the ST D2 24h and 7d met high in, already 5HT2 after 7d and D1 was not alteration. Were evaluated too in the ST the activity of catalase, antioxidant enzyme, that showed a reduction of your activity in the three withdrawal. Results suggests that different times of withdrawal after subcronic treatment with cocaine cause anxyogenic and depressive effects on the CNS and this effects were reverted by the administration of drugs (propranolol, ondansetrom, buspirone, bupropione and paroxetine). The neurochemistry study showed that the abstinence of cocaine were events multimediated and the brain area study ST has an important role, being the catalase activity involved in this process. These findings are important to the investigation of new treatments to the cocaine abstinence syndrome.
Стилі APA, Harvard, Vancouver, ISO та ін.
10

Aguiar, Lissiana Magna Vasconcelos. "Efeitos comportamentais e neuroquÃmicos da melatonina em ratos submetidos à lesÃo estriatal com 6-ohda." Universidade Federal do CearÃ, 2002. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=19.

Повний текст джерела
Анотація:
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico
Os efeitos da melatonina (Mel) in vivo foram estudados no sistema dopaminÃrgico nigroestriatal de ratos, utilizando um modelo experimental da doenÃa de Parkinson que consiste na injeÃÃo intraestriatal da neurotoxina 6-hidroxidopamina (6-OHDA). Ratos Wistar, machos (200-250g) foram submetidos a lesÃo unilateral com 6-OHDA, tratados com melatonina nas doses de 2, 5, 10 e 25 mg/kg, i.p. 1 hora apÃs a lesÃo e depois, diariamente durante 7 dias, quatro semanas apÃs a lesÃo, foi realizado o teste rotacional e 24 horas depois os animais foram sacrificados, os seus cÃrebros dissecados e os estriados direito (ipsilateral â lado lesionado) e esquerdo (contralateral â lado nÃo lesionado) utilizados para dosagens de monoaminas em HPLC e ensaios de binding dopaminÃrgico. Para as dosagens de malonildialdeÃdo (MDA), os animais foram sacrificados no oitavo dia apÃs a lesÃo. Os resultados demonstraram que a injeÃÃo intraestriatal de 6-OHDA diminuiu cerca de 77 à 85% os conteÃdos das monoaminas e dos seus metabÃlitos no lado ipsilateral quando comparado com o lado contralateral nos controles. O tratamento com melatonina, nas doses estudadas, reverteu parcialmente as diminuiÃÃes causadas pela lesÃo com 6-OHDA nos nÃveis destes neurotransmissores, e os conteÃdos se aproximaram de 50% daqueles observados nos lados contralaterais dos controles ou dos grupos tratados com melatonina. A Mel foi mais eficiente na dose de 5 mg/kg, i.p., e os efeitos foram similares entre as doses mais baixas e as mais altas, caracterÃstica de um tipo de resposta com a curva em forma de sino. O prÃ-tratamento e o tratamento crÃnico com melatonina na dose que obteve o melhor efeito tambÃm foram estudados, o tratamento crÃnico promoveu uma melhor recuperaÃÃo dos nÃveis de monoaminas enquanto os efeitos do prÃ-tratamento foram similares aos do grupo Mel 5 mg/kg, durante 7dias. O comportamento rotacional induzido pela apomorfina (3 mg/kg) foi bloqueado em cerca de 60, 89, 78 e 47% nos grupos tratados com melatonina nas doses de 2, 5, 10 e 25 mg/kg, i.p., respectivamente. O tratamento crÃnico bloqueou o comportamento rotacional em cerca de 96% e o prÃ-tratamento 86%. A melatonina (5 mg/kg) produziu uma upregulation dos receptores D1 (Bmax: 277,8+/-25,8) associada com uma diminuiÃÃo nos valores do Kd (1,5+/-0,1) quando comparado ao controle (Bmax:194,8+/-19,0; Kd:2,9+/-0,38). Um efeito similar foi observado com o tratamento com NAS (Bmax: 245,3+/-27,6; Kd: 1,1+/-0,28), precursor da melatonina. Foi verificado um aumento nos nÃveis de MDA, nos controles (127%), quando comparado com o grupo falso operado (104%), o tratamento com melatonina (106%) recuperou esses nÃveis à valores prÃximos do normal, sugerindo uma aÃÃo antioxidante da melatonina in vivo. Os resultados apresentados podem indicar uma aÃÃo neuroprotetora da melatonina e sugerem um possÃvel papel no tratamento de doenÃas neurodegenerativas causadas pelo estresse oxidativo, como a doenÃa de Parkinson.
The present work studied the neuroprotective effects of melatonin In vivo on the nigrostriatal dopaminergic system in rats after a unilateral 6-hydroxydopamine (6-OHDA) lesions in rat striatum. Results showed that the intrastriatal injection of 6-OHDA significantly decreases DA, DOPAC and HVA levels. Although there is also a decrease in 5-HT levels no changes were observed in 5-HIAA levels as compared to controls. On the other hand, melatonin (2, 5, 10 and 25 mg/kg, i.p., daily for 7 days) treatment starting 1 h after 6-OHDA lesions, partially reverses the decreases caused by 6-OHDA lesions on these neurotransmitter levels, and contents were brought to approximately 50% of that observed in the contralateral sides of controls or the melatonin treated group. Melatonin was more efficient at the doses of 5 and 10 mg/kg, i.p., and effects were similar between the lowest and highest doses characteristic of a bell-shaped type of response. Pretreatment and cronic treatment with melatonin at the 5mg/kg dose were also tested, cronic treatment promoted a recovey of monoamines levels more efficiently while the pretreatment effects were similar to the melatonin treatment at the dose of the 5mg/kg for 7 days. The apomorphine-induced rotational behavior (3 mg/kg, i.p.) was blocked by 60, 89, 78 and 47% after the doses of 2, 5, 10 and 25 mg/kg, i.p., respectively. Similarly, in this case the doses of 5 and 10 mg/kg were also more efficient. The cronic treatment blocked the rotational behavior by 86%. Melatonin (5mg/kg) produced an upregulation of D1 receptors associated with a decrease in Kd value. While no change was observed in maximum density of D2 receptors, the Kd value was also decreased, a similar effect was observed with its precursor N-acetylserotonin. Compared with sham-operated and expressed as a ratio relative to the contralateral side, there was an increase in the lipid peroxidation product malondialdehyde (MDA, 127%) on controls which was restored to normal levels on the melatonin treated group, suggesting the in vivo action of melatonin as an antioxidant. The present results may indicate a neuroprotective action of melatonin and suggest a possible role in the treatment of oxidative stress-induced neurodegenerative disease such as Parkinsonâs disease.
Стилі APA, Harvard, Vancouver, ISO та ін.

Книги з теми "Monoamides"

1

Binda, Claudia, ed. Monoamine Oxidase. New York, NY: Springer US, 2023. http://dx.doi.org/10.1007/978-1-0716-2643-6.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
2

Oreland, Lars, and Brian A. Callingham, eds. Monoamine Oxidase Enzymes. Vienna: Springer Vienna, 1987. http://dx.doi.org/10.1007/978-3-7091-8901-6.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
3

National Institutes of Health (U.S.), ed. Low monoamine (LMA) diet. [Bethesda, Md.?: U.S. Dept. of Health and Human Services, Public Health Service, National Institutes of Health, 1989.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
4

Szelenyi, I., ed. Inhibitors of Monoamine Oxidase B. Basel: Birkhäuser Basel, 1993. http://dx.doi.org/10.1007/978-3-0348-6348-3.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
5

Roberts, M. H. T. The central and antinociceptive actions of the monoamines. Birmingham: University of Birmingham, 1986.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
6

H, Yasuhara, ed. Monoamine oxidase: Basic and clinical aspects. Utrecht, Netherlands: VSP, 1993.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
7

Van Bockstaele, Elisabeth J., ed. Endocannabinoid Regulation of Monoamines in Psychiatric and Neurological Disorders. New York, NY: Springer New York, 2013. http://dx.doi.org/10.1007/978-1-4614-7940-6.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
8

H, Kennedy Sidney, ed. Clinical advances in monoamine oxidase inhibitor therapies. Washington, DC: American Psychiatric Press, 1994.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
9

Ebrahimi, Soltan Ahmed. Characterisation of guinea pig liver monoamine oxidase. Portsmouth: University of Portsmouth, School of Pharmacy and Biomedical Science, 1995.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
10

G, Priest R., ed. Depression and reversible monoamine oxidase inhibitors: New perspectives. London: Royal College of Psychiatrists, 1989.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.

Частини книг з теми "Monoamides"

1

Morgan, Michael M., MacDonald J. Christie, Thomas Steckler, Ben J. Harrison, Christos Pantelis, Christof Baltes, Thomas Mueggler, et al. "Monoamines." In Encyclopedia of Psychopharmacology, 795. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-540-68706-1_464.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
2

Morgan, Michael M., MacDonald J. Christie, Thomas Steckler, Ben J. Harrison, Christos Pantelis, Christof Baltes, Thomas Mueggler, et al. "Monoamine Depletion." In Encyclopedia of Psychopharmacology, 791. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-540-68706-1_3405.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
3

Morgan, Michael M., MacDonald J. Christie, Thomas Steckler, Ben J. Harrison, Christos Pantelis, Christof Baltes, Thomas Mueggler, et al. "Monoamine Hypotheses." In Encyclopedia of Psychopharmacology, 791. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-540-68706-1_3406.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
4

Rey, Jose A. "Monoamine Oxidase." In Encyclopedia of Clinical Neuropsychology, 1654–55. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-0-387-79948-3_1742.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
5

Rey, Jose A. "Monoamine Oxidase." In Encyclopedia of Clinical Neuropsychology, 1. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-56782-2_1742-2.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
6

Edmondson, Dale E., and Claudia Binda. "Monoamine Oxidases." In Subcellular Biochemistry, 117–39. Singapore: Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-10-7757-9_5.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
7

Rey, Jose A. "Monoamine Oxidase." In Encyclopedia of Clinical Neuropsychology, 2264. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-57111-9_1742.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
8

Hillard, Cecilia J. "Endocannabinoids, Monoamines and Stress." In Endocannabinoid Regulation of Monoamines in Psychiatric and Neurological Disorders, 173–212. New York, NY: Springer New York, 2013. http://dx.doi.org/10.1007/978-1-4614-7940-6_9.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
9

Singer, T. P. "Perspectives in MAO: past, present, and future." In Monoamine Oxidase Enzymes, 1–23. Vienna: Springer Vienna, 1987. http://dx.doi.org/10.1007/978-3-7091-8901-6_1.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
10

Tipton, K. F., Anne-Marie O’Carroll, and J. M. McCrodden. "The catalytic behaviour of monoamine oxidase." In Monoamine Oxidase Enzymes, 25–35. Vienna: Springer Vienna, 1987. http://dx.doi.org/10.1007/978-3-7091-8901-6_2.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.

Тези доповідей конференцій з теми "Monoamides"

1

Verlinden, Heleen. "Monoamine receptors and swarming behaviour in locusts." In 2016 International Congress of Entomology. Entomological Society of America, 2016. http://dx.doi.org/10.1603/ice.2016.95192.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
2

Serra, Silvia, Eugenio Uriarte, Lourdes Santana, Giovanna Delogu, and Maria Matos. "Synthesis of New Possible Monoamine Oxidase Inhibitors." In The 14th International Electronic Conference on Synthetic Organic Chemistry. Basel, Switzerland: MDPI, 2010. http://dx.doi.org/10.3390/ecsoc-14-00378.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
3

Serra, Silvia, Eugenio Uriarte, Lourdes Santana, Giovanna Delogu, and Maria Matos. "Synthesis of new possible monoamine oxidase inhibitors." In The 14th International Electronic Conference on Synthetic Organic Chemistry. Basel, Switzerland: MDPI, 2010. http://dx.doi.org/10.3390/ecsoc-14-00474.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
4

Barmatov, Evgeny, and Dimitri Khramov. "Research on the Chemistry of Emulsifiers for Nonaqueous Drilling Fluids." In SPE International Conference on Oilfield Chemistry. SPE, 2023. http://dx.doi.org/10.2118/213873-ms.

Повний текст джерела
Анотація:
Abstract High-performance nonaqueous fluids (HP NAF) are complex engineering systems. The emulsifier is the backbone of any NAF; therefore, highest return on investment is likely to come from the development of emulsifier chemistry. The objective of the present research is to improve the knowledge of different reactions that occur during synthesis of an emulsifier and investigate how the different products of the synthesis impact emulsifier performance in a NAF. Creating a new emulsifier is a one-step process of C18 amine condensation and various cyclic anhydrides. Reaction time and temperature was varied in this work to generate different reaction products, and analytical techniques, such as 1H nuclear magnetic resonance (NMR), 13C NMR, Fourier transform infrared spectroscopy (FTIR), and gel permeation chromatography were used to investigate the mechanism of the chemical reaction and for reaction process optimization. The reaction is a simple formation of a monoamide between the amine and the cyclic anhydride; however, secondary reactions are possible that decrease the emulsifier performance. The monoamide that forms initially can be transformed into other species under elevated temperatures, which no longer function as emulsifiers. This paper presents the performance of a new emulsifier in a HP NAF and provides a systematic insight into various chemical transformations that are possible when attempting to use this amide-formation reaction to create an emulsifier. Development of structure-activity relationships for chemical components of emulsifiers and a systematic knowledge of invert emulsion performance will improve the comprehension of emulsifier performance in an HP NAF. This knowledge can be applied to improve emulsion stability and rheology of a drilling fluid.
Стилі APA, Harvard, Vancouver, ISO та ін.
5

Ma, Peixiang, Shanshan Wang, Feng Qu, and Yulin Deng. "Determination of Monoamine Oxidase Activity by Capillary Electrophoresis Method." In 2007 IEEE/ICME International Conference on Complex Medical Engineering. IEEE, 2007. http://dx.doi.org/10.1109/iccme.2007.4382056.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
6

Bayer, A., E. Zrenner, H. J. Thiel, S. Ried, and D. Schmidt. "Early detection of anticonvulsant drug toxicity by colour vision tests." In Noninvasive Assessment of the Visual System. Washington, D.C.: Optica Publishing Group, 1991. http://dx.doi.org/10.1364/navs.1991.md10.

Повний текст джерела
Анотація:
Phenytoin and Carbamazepine, especially in combination or after repeated exposure to toxic blood concentrations, can produce neurological and mental syndroms. Possible mechanisms of impaired neurological and mental function include neuronal damage, or disturbance of folic acid, monoamine or hormonal metabolism. Phenytoin and Carbamazepine may also impair the ocular system. The most common symptoms are diplopia, nystagmus and blurred vision. Cerebellar or vestibulo-ocular dysfunction is suspected as mechanism of these ocular adverse effects.
Стилі APA, Harvard, Vancouver, ISO та ін.
7

"Monoamine signaling gene networks unraveled in mouse social stress model." In Bioinformatics of Genome Regulation and Structure/ Systems Biology. institute of cytology and genetics siberian branch of the russian academy of science, Novosibirsk State University, 2020. http://dx.doi.org/10.18699/bgrs/sb-2020-172.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
8

Yurttas, Leyla, Asaf Evren, Demokrat Nuha, Sam Dawbaa, and Begüm Sağlık. "New thiazolylhydrazone derivatives as potent monoamine oxidase and aromatase inhibitors." In 7th International Electronic Conference on Medicinal Chemistry. Basel, Switzerland: MDPI, 2021. http://dx.doi.org/10.3390/ecmc2021-11582.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
9

Yan, Shaomin, and Guang Wu. "Distributions of amino acids in the primary structure of monoamine oxidase family." In International Conference on Biomedical and Intelligent Systems (IC-BIS 2022), edited by Ahmed El-Hashash. SPIE, 2022. http://dx.doi.org/10.1117/12.2660263.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
10

Kamruzzaman, A. S. M. "Integration of midgut-fat body-gonadal axis inPeriplaneta americana: Monoamine and peptide regulation." In 2016 International Congress of Entomology. Entomological Society of America, 2016. http://dx.doi.org/10.1603/ice.2016.94434.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.

Звіти організацій з теми "Monoamides"

1

Mincher, Bruce Jay. Radiation chemistry of the branched-chain monoamide di-ethylhexyl-isobutyramide. Office of Scientific and Technical Information (OSTI), September 2016. http://dx.doi.org/10.2172/1406976.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
2

Jacobs, Barry L. Central Postsynaptic Actions of Monoamine Neurotransmitters in Behaving Animals. Fort Belvoir, VA: Defense Technical Information Center, March 1997. http://dx.doi.org/10.21236/ada325701.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
3

Gluck, Martin R. Parkinson's Disease: The Link Between Monoamine Oxidase and Mitochondrial Respiration. Fort Belvoir, VA: Defense Technical Information Center, April 2004. http://dx.doi.org/10.21236/ada612171.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
4

Shih, Jean C., and Bogdan Z. Olenyuk. Monoamine Oxidase A: A Novel Target for Progression and Metastasis of Prostate Cancer. Fort Belvoir, VA: Defense Technical Information Center, October 2014. http://dx.doi.org/10.21236/ada612725.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
5

Shih, Jean C., and Bogdan Z. Olenyuk. Monoamine Oxidase A: A Novel Target for Progression and Metastasis of Prostate Cancer. Fort Belvoir, VA: Defense Technical Information Center, October 2013. http://dx.doi.org/10.21236/ada593309.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Ми пропонуємо знижки на всі преміум-плани для авторів, чиї праці увійшли до тематичних добірок літератури. Зв'яжіться з нами, щоб отримати унікальний промокод!

До бібліографії