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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
221

Instrumentation on silicon detectors: from properties characterization to applications

Dinu, N. 09 October 2013 (has links) (PDF)
L'utilisation optimale, dans des applications spécifiques, des Détecteurs Silicium nécessite une connaissance approfondie des phénomènes physiques sous-jacents. Dans ce mémoire, cette idée conductrice est appliquée à deux types de détecteurs : (1) les SiPM et leurs applications en imagerie médicale (2) les détecteurs à pixels planaires (PPS) et leurs applications dans la mise-à-jour du détecteur interne d'ATLAS pour le LHC à haute luminosité. Mon travail personnel sur les SiPM a débuté il y a environ 10 ans. Ainsi la partie (A) de mon HDR rappelle tout d'abord le principe physique de la photodiode à avalanche en mode Geiger (GM-APD), qui constitue la cellule élémentaire d'un SiPM. Puis le fonctionnement du SiPM est développé, avec ses principales caractéristiques physiques, ainsi que les montages expérimentaux mis en œuvre et les mesures de ces paramètres sur les productions des principaux fabricants. La dépendance en température des paramètres des SiPM constitue un inconvénient majeur dans certaines applications, aussi mon travail personnel montre comment on peut en grande partie s'affranchir de cette dépendance, en contrôlant certains paramètres de fonctionnement. Les détecteurs à SiPM présentent des avantages très intéressants au plan électrique, optique, mécanique, etc ..., permettant des applications multiples dans des domaines où une grande surface de détection est requise. Ainsi, les matrices de SiPM sont des composants très attractifs pour des applications d'imagerie médicale. Mon travail dans deux applications de ce type est détaillé : PET à haute résolution pour des petits animaux, et détecteur de radiation portatif pour l'aide à la localisation in situ de tumeurs solides. En parallèle à l'activité SiPM, j'ai été impliquée ces dernières années dans la conception et la caractérisation de nouveaux détecteurs à pixel planaires pour "l'upgrade" de l'expérience ATLAS. La partie (B) de mon HDR expose ainsi les méthodes expérimentales, comme "Secondary Ion Mass Spectrometry (SIMS)" et "Spreading Resistance Profiling" (SRP), utilisées pour la mesure de profils de dopage pour le détecteurs PPS. Je démontre ainsi l'importance de ces mesures pour le contrôle du process de fabrication, et la calibration des simulations TCAD (Technology-Computed Aided Design). Les résultats des simulations prévoyant le comportement des nouveaux détecteurs planaires proposés, avec des caractéristiques géométriques et une résistance aux radiations améliorées, sont présentés.
222

Investigação do ácido etanodióico na formação de filmes superficiais sobre zinco e avaliação do efeito destes filmes na resistência à corrosão / Investigation of the ethanedioic acid on the formation of surface films on zinc and evaluation of the effect of these films formed on the corrosion resistance

Oliveira, Marcelo de 14 August 2017 (has links)
Um dos métodos mais utilizados para proteção contra a corrosão de aços comuns consiste na proteção catódica com revestimentos metálicos eletroquimicamente mais ativos, que estes. Os revestimentos de zinco são os mais usados para este tipo de proteção. De forma a protegerem o substrato, estes revestimentos devem atuar como anodos de sacrifício, sofrendo corrosão e transformando o substrato de aço em catodo. Todavia, não é de interesse, que o revestimento de zinco apresente altas taxas de corrosão de forma que a proteção contra a corrosão conferida ao aço seja duradoura. Uma das formas mais empregadas para reduzir a velocidade de corrosão do revestimento de zinco é por meio de tratamentos da superfície, por exemplo, por tratamentos de conversão. Os tratamentos de conversão mais eficientes são os que utilizam e geram rejeitos, que contêm íons de cromo hexavalente. Todavia, estes íons são carcinogênicos e tóxicos e, dessa forma, os processos que os utilizam em alguma etapa do tratamento, vêm sofrendo crescentes restrições, já sendo proibidos em países com leis ambientais mais rígidas. Esta é a razão para o crescente interesse e grande investimento em pesquisa tratamentos, que possam resultar em revestimentos com potencialidade para substituir, de forma eficiente e efetiva o uso do cromo hexavalente. Este foi o objetivo do presente trabalho. Neste estudo, foi investigado o efeito de tratamentos, que resultam em camadas de conversão na presença de ácido oxálico e na proteção contra a corrosão da superfície do zinco. Camadas de conversão foram obtidas por imersão de amostras de zinco em soluções de ácido oxálico (ácido etanodióico) com diferentes concentrações. Todas as soluções de tratamento apresentaram elevada acidez e resultaram em ataque da superfície de zinco com formação de revestimento de conversão com diferentes características. Ensaios preliminares de névoa salina foram então realizados para investigar a proteção conferida pelo sistema revestimento de conversão-verniz contra a corrosão do substrato de zinco. Estes ensaios foram decisivos para a escolha da faixa de concentração do banho de conversão com maior potencial para formação de revestimentos de conversão protetores. Os resultados deste ensaio e os de espectroscopia de impedância eletroquímica mostraram que tratamentos em soluções com composição superiores a 10-1 M de ácido oxálico resultaram em camadas muito defeituosas, nas quais o ataque localizado do substrato metálico é favorecido, sendo obtidas impedâncias menores que a superfície do zinco sem qualquer tratamento. Os resultados de XPS mostraram, que os revestimentos de conversão formados em soluções de ácido oxálico na faixa de 10-3 M a 10-1 M são compostos de oxalato de zinco e produtos de corrosão do zinco, especificamente ZnO, Zn (OH)2, e ZnCO3. Já a concentração de 10-1 M de ácido oxálico foi a, que produziu os resultados mais promissores com a formação de um revestimento, que conferiu proteção mais duradoura à superfície do zinco entre os obtidos. As espessuras médias das camadas de conversão de oxalato de zinco formadas em soluções com 10-1 M e 1 M de ácido oxálico, estimadas por FIB, foram respectivamente 600 nm e 300 nm, o que mostra que a concentração de 1 M de ácido causou intenso ataque corrosivo da superfície, enquanto a camada formada em meio com 10-1 M permitiu a deposição de camada mais espessa e mais protetora contra a corrosão do substrato. Os resultados de XPS indicaram a degradação da camada de oxalato de zinco com o tempo de ensaio, porém o ataque desta ao longo do ensaio de corrosão, resulta na formação de simonkolleite, identificada por difração de raios X, para períodos mais longos do ensaio de corrosão, no caso do revestimento formado em solução com 10-1 M em comparação a 1M. A simonkolleite atua por efeito barreira bloqueando os defeitos/porosidade da camada. O crescente acúmulo destes produtos de corrosão com a continuidade do processo corrosivo e a aderência destes ao substrato metálico foi indicada para superfície tratada em solução com 10-1 M de ácido oxálico. Finalmente, foi proposto um modelo para interação entre o revestimento de conversão de oxalato de zinco e os produtos de corrosão em que a retenção dos produtos de corrosão na superfície faz com, que a camada na superfície se torne mais espessa e mais compacta com o tempo de exposição ao ensaio de corrosão. Estas observações explicam o aumento de impedância observado com o tempo de ensaio nesta condição. Os resultados obtidos permitiram concluir, que o revestimento de conversão de oxalato de zinco formado em solução com 10-1 M de ácido oxálico resulta em proteção efetiva do substrato metálico além de apresentar boa aderência com camada de verniz. Estes resultados indicam potencialidade deste tratamento como preparação de superfícies de zinco, que serão recobertas com revestimentos orgânicos (tintas, vernizes ou lacas). / One of the most used methods for protection of common steels is the cathodic protection by galvanic coupling with metallic coatings electrochemically more active than these. Zinc coatings are the most commonly used for this type of protection. In order to protect the metallic substrate, these coatings must act as sacrificial anodes, corroding themselves and converting the steel substrate into cathode. However, it is not appropriate that the zinc coating presents high corrosion rates, so that the corrosion protection conferred to the steel is long-lasting. One of the most commonly employed methods of reducing the corrosion rate of zinc coatings is by surface treatments, such as, conversion treatments. The most efficient conversion treatments to date are those that use hexavalent chromium ions or generate residues containing these ions. However, hexavalent chromium is carcinogenic and toxic and, therefore, the processes that involve their use at some stage of the treatment, are under increasing restrictions, and have already been prohibited in developed countries. This is the reason for the growing interest and great investment in research studies in search for treatments that may result in coatings with the potential to efficiently and effectively replace the use of hexavalent chromium. This was the objective of the present study. In this study, the effect of treatments in oxalic acid solutions that resulted in conversion layers on the corrosion protection of zinc surface has been investigated. Conversion layers were obtained by immersion of zinc samples in solutions of oxalic acid (ethanedioic acid) with different concentrations. All the treatment solutions presented high acidity and resulted in attack of zinc surface and formation of conversion coatings of different characteristics. A layer of varnish was applied and preliminary salt spray tests were then carried out to investigate the corrosion protection provided by the system conversion coating -varnish to the zinc substrate. These tests were decisive for the choice of the conversion bath composition range with greater potentialities for the formation of protective conversion coatings. The results of the salt spray test and of electrochemical impedance spectroscopy (EIS) showed that treatments in solutions with compositions greater than 10-1 M of oxalic acid resulted in very defective conversion layers in which the localized attack of the metallic substrate is favored, and lower impedances than the zinc surface without any treatment were obtained for surfaces treated in these solution. The XPS results showed that conversion coatings formed in oxalic acid solutions in the range of 10-3 M to 10-1 M are composed of zinc oxalate and zinc corrosion products, specifically ZnO, Zn (OH)2, and ZnCO3. The concentration related to the most promising results was 10-1 M and in this solution, the coating formed that promoted the longer lasting protection of the zinc surface among those obtained. The average thicknesses of the zinc oxalate conversion layers formed in solutions with 10-1 M and 1 M of oxalic acid, estimated by FIB, were respectively 600 nm and 300 nm. This result showed that in 1 M of oxalic acid an intense corrosive attack of the zinc surface occurred, while the layer formed in 10-1 M was thicker and more protective against substrate corrosion. The XPS results indicated degradation of the zinc oxalate layer formed in 10-1 M solution with time of exposure to the test solution, but for the protection of the coating lasted for longer periods, comparatively to that formed in 1M solution, once the attack of the first film resulted in formation of simonkolleite, which was identified by X-ray diffraction. Simonkolleite acts by barrier effect blocking defects / porosity in the conversion layer. The increasing accumulation of corrosion products with test time and their adhesion to the metallic substrate was indicated for surface treated in solution with 10-1 M of oxalic acid. Finally, a model has been proposed for the interaction between the zinc oxalate conversion coating and the corrosion products in which the retention of these products on the surface is promoted by the conversion coating and the surface layer becomes thicker and more compact with time of exposure. These observations explain the increased impedance observed with the test time associated to this coating. The obtained results allowed concluding that the conversion coating of zinc oxalate formed in solution with 10-1 M of oxalic acid results in effective protection of the metallic substrate besides promoting good adhesion with a layer of varnish. These results indicate the potential of this treatment as preparation of zinc surfaces that will be covered with organic coatings (paints, varnishes or lacquers).
223

Synthèse et caractérisation de couches de polystyrène et de polystyrène sulfoné obtenues par polymérisation-plasma à pression (sub)-atmosphérique / Synthesis and characterization of polystyrene and sulfonated polystyrene coatings obtained by plasma-polymerization under (sub)-atmospheric pressure

Merche, Delphine 31 August 2011 (has links)
Lors de ce travail, de fins films de polystyrène ont été déposés dans la post-décharge d’une torche plasma atmosphérique commerciale, mais aussi dans la décharge d’une DBD (Décharge à Barrière Diélectrique), conçue et développée par nos soins au laboratoire. Une DBD est un procédé permettant d’obtenir des plasmas froids à pression atmosphérique. <p><p>Nos résultats ont montré que la DBD permettait d’obtenir des films de polystyrène de meilleure qualité (degré d’oxydation moindre…) qu’avec la torche commerciale en raison de l’atmosphère contrôlée de l’enceinte DBD. Les films sont déposés en présence d’un gaz porteur (Ar ou He dans la DBD). Nous avons pu mettre en évidence l’influence de la nature de ce gaz porteur sur la structure des films (degré de branchement, et de réticulation des films et de préservation des cycles aromatiques de la molécule de départ). <p><p>Les dépôts de polystyrène sulfoné ont été synthétisés dans la DBD en une seule étape, par « copolymérisation » de deux précurseurs (styrène et acide trifluorométhane sulfonique) injectés simultanément dans la décharge. Ces membranes pourraient servir d’électrolyte dans les piles à combustibles miniaturisées de type PEMFC (« Polymer Electrolyte Membrane Fuel Cell »), utilisant de l’hydrogène ou du méthanol et ce pour des applications portables. <p><p>L’acide trifluorométhane sulfonique permet le greffage de groupements sulfoniques échangeurs d’ions (nécessaires pour la conductivité de la membrane) sur le squelette de polystyrène. <p><p>La complémentarité des différentes techniques spectroscopiques utilisées -Spectroscopie des Photoélectrons X (XPS), Infra-Rouge à Transformée de Fourier (FTIR), Spectroscopie des Ions Secondaires (SIMS) statique et dynamique- ont montré que les groupements acides sulfoniques (bien préservés dans la décharge à pression sub-atmosphérique) étaient bien greffés dans la matrice de polystyrène, et ce sur toute l’épaisseur de la membrane. L’influence des paramètres (température de l’acide, tension appliquée entre les électrodes, nature du gaz porteur…) sur la quantité de groupements ionisables greffés, sur la vitesse de dépôt et aussi sur la morphologie des films a été étudiée respectivement par XPS et par microscopie. <p><p>En plus des dépôts sur substrats usuels (Si, acier…) utilisés pour les caractérisations chimiques, nous avons synthétisé les films directement sur des électrodes de carbone enrichies en platine.<p> <p>Nous avons déposé le catalyseur à partir d’une solution colloïdale de platine nébulisée dans la post-décharge d’une torche plasma atmosphérique sur des couches de carbones poreuse et sur du carbone vitreux (utilisé comme modèle pour le profilage par SIMS dynamique) dans différentes configurations et ce pour différents paramètres afin de constituer des électrodes servant de substrat pour l’adhésion de la membrane-plasma pour des perspectives d’assemblage membrane-électrodes pour PAC. /<p><p>\ / Doctorat en Sciences / info:eu-repo/semantics/nonPublished
224

Jonctions ultra-minces p+/n pour MOS "ultimes étude de l'impact des défauts sur la mobilité et l'activation du bore

Severac, Fabrice 24 April 2009 (has links) (PDF)
La réalisation des transistors MOS de taille "ultime" nécessite la fabrication de jonctions source et drain ultra-minces (quelques dizaines de nanomètres), abruptes et fortement dopées. L'optimisation du procédé de fabrication de ces jonctions nécessite la compréhension des phénomènes physiques qui interviennent lors des différentes étapes de fabrication, en particulier l'impact des défauts cristallins sur leurs paramètres électriques. Dans ce travail, nous avons étudié l'impact des précipités de bore (BICs, Boron-Interstitial Clusters) mais aussi des défauts EOR (End-Of-Range), sur la mobilité des porteurs et l'activation des dopants (principalement le bore dans le silicium). Tout d'abord, nous avons développé un modèle d'analyse mathématique basé sur le profil de concentration des dopants mesuré par SIMS et sur les valeurs " standards " de mobilité des porteurs. Ce modèle permet de déterminer par le calcul les trois paramètres électriques mesurés par effet Hall : la résistance carrée, la dose active de dopants et la mobilité des porteurs. A partir de l'utilisation de ce modèle, nous démontrons qu'en présence de BICs, il s'avère nécessaire de modifier la valeur d'un facteur correctif, le facteur de scattering, essentiel pour les mesures par effet Hall, et nous déterminons sa valeur. Nous mettons ensuite en évidence la dégradation de la mobilité des porteurs par les BICs, puis étudions de manière plus quantitative l'évolution de cette dégradation en fonction de la quantité de BICs. Par la suite, une étude sur l'activation du bore en présence de défauts EOR est menée. Enfin, nous élargissons notre étude sur ces mêmes paramètres électriques au cas de nouveaux matériaux tels que le SOI (Silicon-On-Insulator) ou le SiGe (alliage silicium/germanium), matériaux utilisés pour les dernières générations de transistors.
225

Etude de la redistribution des dopants et des éléments d'alliages lors de la formation des siliciures

Hoummada, Khalid 24 October 2007 (has links) (PDF)
L'objectif de cette étude est de caractériser la redistribution d'éléments d'alliages et de dopants au cours des premiers stades de formation des siliciures de Ni. Pour cela, nous avons étudié la nature, la séquence et la cinétique des phases formées, dans un premier temps pour les systèmes binaires Pd/Si, Pt/Si et Ni/Si, puis pour les systèmes ternaires (Ni,Pt)/Si et Ni/(Si, As) présentant un intérêt technologique pour la nanoélectronique. Ainsi, nous avons couplé des techniques de caractérisation originales (calorimétrie différentielle à balayage sur films minces, sonde atomique tomographique, diffraction des rayons X in situ) pour mesurer la redistribution du Pt dans les phases formées et leurs cinétiques de croissance. Nous avons pu développer un modèle pour décrire les premiers stades de croissance de ces siliciures alliés et dégager les mécanismes mis en jeu ainsi que les facteurs limitant la redistribution des éléments d'alliage et des dopants.
226

ToF-SIMS Investigations on Dental Implant Materials and Adsorbed Protein Films

Bernsmann, Falk 13 July 2007 (has links) (PDF)
In this work the two experimental dental implant materials FAT and FAW, made of fluoroapatite particles embedded in polymer matrices, and films of the proteins lysozyme, amylase and bovine serum albumin (BSA), adsorbed to the two dental implant materials, were investigated with time-of-flight secondary ion mass spectrometry (ToF-SIMS) and the multivariate data analysis technique discriminant principal component analysis (DPCA).
227

Etude des dépôts par plasma ALD de diélectriques à forte permittivité diélectrique (dits « High-K ») pour les applications capacités MIM

Monnier, D. 09 April 2010 (has links) (PDF)
La miniaturisation des composants dans la micorélectronique touche maintenant les composants passifs comme les capacités MIM (Métal/Isolant/Métal). Pour augmenter la densité de capacité des capacités MIM, les diélectriques conventionnels (SiO2, ε = 3.9) sont remplacés par des diélectriques à haute permittivité diélectrique dits « high-k » comme ZrO2. Sa permittivité ε est égale à 47 lorsqu'il se trouve sous la phase tétragonale. Le procédé de dépôt de ZrO2 est la méthode PEALD. Nous avons étudié le procédé de dépôt de ZrO2 avec les précurseurs TEMAZ et ZyALD. Les propriétés thermodynamiques du TEMAZ ont été analysées par spectrométrie de masse. L'influence des paramètres du procédé PEALD et de post-traitements sur les mécanismes de formation de la zircone tétragonale a été étudiée. De nombreuses méthodes de caractérisation (XRD, Raman, TEM, SIMS, XPS, caractérisations électriques...) ont été employées afin d'établir un optimum propriétés des films de ZrO2 / performance du procédé de dépôt.
228

Molecular and epidemiological studies on eyes with pseudoexfoliation syndrome

Botling Taube, Amelie January 2015 (has links)
Pseudoexfoliation (PEX) syndrome is an age-related condition characterized by the production and accumulation of extracellular fibrillary material in the anterior segment of the eye. PEX predisposes for several pathological conditions, such as glaucoma and complications during and after cataract surgery. The pathogenesis of PEX is not yet fully understood. It is multifactorial with genetics and ageing as contributing factors. We aimed to study the proteome in aqueous humor (AH) in PEX in order to increase the knowledge about its pathophysiology. Therefore, we developed sampling techniques and evaluated separation methods necessary for analyzing small sample volumes. Other objectives were to study the lens capsule in eyes with PEX regarding small molecules, and to investigate the association between PEX and cataract surgery in a population-based 30-year follow-up study. Samples of AH from eyes with PEX and control eyes were collected during cataract surgery. In pooled, and individual samples, various liquid based separation techniques and high resolution mass spectrometry were utilized. For quantitation, various methods for labeling, and label free techniques were applied. Lens capsules were collected from some of the patients, and analysed by imaging mass spectrometry. A cohort of 1,471 elderly individuals underwent a comprehensive ophthalmological examination at baseline. Medical information was obtained by questionnaires, and from medical records. Incident cases of cataract surgery were identified by review of medical records. In the initial study, several techniques were explored for protein detection, and a number of proteins were identified as differentially expressed. In the individually labelled samples, changes in the proteome were observed. Eyes with PEX contained higher levels of proteins involved in inflammation, oxidative stress, and coagulation, suggesting that these mechanisms are involved in the pathogenesis in PEX. The levels of β/γ-crystallins were significantly increased in PEX, which is a novel finding. In the lens capsules from individuals with PEX, changes in the lipid composition was observed with time-of-flight secondary ion mass spectrometry. These changes remain to be elucidated. By multivariate analysis, lens opacities were the first, and PEX the second most important predictor for cataract surgery, the later accounting for a 2.38-fold increased risk for cataract surgery.
229

The application of time-of-flight secondary ion mass spectrometry (ToF-SIMS) to forensic glass analysis and questioned document examination

Denman, John A January 2007 (has links)
The combination of analytical sensitivity and selectivity provided by time-of-flight secondary ion mass spectrometry (ToF-SIMS), with advanced statistical interrogation by principal component analysis (PCA), has allowed a significant advancement in the forensic discrimination of pen, pencil and glass materials based on trace characterisation.
230

Avalia??o de duas variedades de Passiflora edulis sobre as respostas comportamentais de camundongos e um poss?vel mecanismo de a??o

Ayres, Adriana Soeiro de Farias Silva Junqueira 11 December 2015 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-08-09T23:58:08Z No. of bitstreams: 1 AdrianaSoeiroDeFariasSilvaJunqueiraAyres_TESE.pdf: 4492005 bytes, checksum: 363e585cddc1b3b004eb5170356b575b (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-08-15T23:16:31Z (GMT) No. of bitstreams: 1 AdrianaSoeiroDeFariasSilvaJunqueiraAyres_TESE.pdf: 4492005 bytes, checksum: 363e585cddc1b3b004eb5170356b575b (MD5) / Made available in DSpace on 2016-08-15T23:16:31Z (GMT). No. of bitstreams: 1 AdrianaSoeiroDeFariasSilvaJunqueiraAyres_TESE.pdf: 4492005 bytes, checksum: 363e585cddc1b3b004eb5170356b575b (MD5) Previous issue date: 2015-12-11 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / As plantas medicinais constituem uma rica fonte de compostos biologicamente ativos com seu potencial terap?utico para o tratamento de diversos transtornos psiqui?tricos, como os transtornos de ansiedade e depress?o. O transtorno de ansiedade generalizada tem aumentado de forma significativa, sendo o segundo transtorno mais prevalente em locais de assist?ncia ? sa?de p?blica. A depress?o ? considerada um transtorno psiqui?trico cr?nico e comum que afeta 350 milh?es de indiv?duos de todas as idades ao redor do mundo. Neste contexto as condutas de interven??o farmacol?gica que v?m sendo empregadas, embora eficazes, deixam a desejar, quando observados seus efeitos adversos. A Passiflora ? uma variedade comumente conhecida comercialmente, mas tamb?m ? usada na medicina tradicional brasileira. A Passiflora edulis exibe consider?vel variabilidade morfol?gica. Esta planta produz dois tipos de fruto: o roxo (P. edulis var. edulis) e o amarelo (P. edulis var. flavicarpa). O presente estudo investigou os efeitos centrais do extrato aquoso das folhas de duas variedades da esp?cie Passiflora edulis em testes comportamentais utilizados para avaliar comportamentos relacionados ? ansiedade e depress?o, bem como investigou o potencial efeito do tipo antidepressivo das subfra??es da Passiflora edulis var. edulis e os mecanismos neurofarmacol?gicos respons?veis por essa a??o. Para a realiza??o desse estudo foram utilizados camundongos Swiss machos (2 meses de idade, pesando 30-35 g). Os animais receberam o extrato aquoso das folhas das duas esp?cies de Passiflora: Passiflora edulis Sims var. edulis (PEE - 100, 300, 1000 mg/Kg) e subfra??es AcOet, BuOH e residual (25, 50, 75, 100 mg/Kg), e a P. edulis var. flavicarpa (PEF - 30, 100, 300, 1000 mg/Kg) ou solu??o salina, por gavagem, 60 minutos antes dos testes do labirinto em cruz elevado (LCE), teste de campo aberto (TCA), teste de nata??o for?ada (TNF) e teste de seda??o induzido por tiopental. Para investigar o mecanismo de a??o da atividade do tipo antidepressiva das subfra??es foram utilizadas as seguintes drogas: PCPA (inibidor da s?ntese de 5-HT), AMPT (inibidor da s?ntese de catecolaminas), DSP-4 (neurotoxina noradren?rgica) e Sulpiride (antagonista seletivo de receptor dopamin?rgico D2). Foram utilizados como controle positivo padr?o, a fluoxetina e a nortriptilina. Os resultados do perfil fitoqu?mico demonstram caracter?sticas bem distintas para o extrato aquoso das variedades de P. edulis ?flavicarpa? e ?edulis?. Os extratos aquosos de ambas as variedades de P. edulis compartilham atividade do tipo ansiol?tica (PEE 300 mg/Kg; PEF 300 e 1000 mg/Kg) e antidepressiva (PEE 300 mg/Kg; PEF 1000 mg/Kg), enquanto o efeito hipolocomotor/sedativo s? foi visto para a PEE (1000 mg/Kg). Ambas subfra??es AcOet e BuOH do extrato aquoso da PEE apresentaram atividade do tipo antidepressiva na dose de 50 mg/Kg no TNF. Os dados sugerem que o efeito do tipo antidepressivo das subfra??es da P. edulis envolve a neurotransmiss?o serotonin?rgica e catecolamin?rgica, principalmente dopamin?rgica, haja visto que o pr?-tratamento com DSP-4 n?o afetou a a??o antidepressiva das subfra??es, enquanto que mostrou ser dependente da ativa??o de receptores dopamin?rgicos D2. / The medicinal plants constitute a rich source of biologically active compounds used for the treatment of many psychiatric disorders, such as anxiety disorders and depression. Generalized anxiety disorder has increased significantly, being the second most prevalent disorder in care facilities to public health. Depression is considered a chronic and common psychiatric disorder that affects 350 million people of all ages around the world. In this context, the pharmacological intervention conduits have been employed, effective, although leave to be desired when observed adverse effects. The genus Passiflora is commonly commercially known by its fruit, but is also widely used in traditional Brazilian medicine. Passiflora edulis displays considerable morphological variability. This plant produces two types of fruit: Purple (Passiflora edulis Sims fo. edulis) and yellow (Passiflora edulis fo. flavicarpa Degener). This study investigated the central effects of aqueous extract of the leaves of the two varieties of the species Passiflora edulis in tests used to assess behavior related to anxiety and depression, as well as investigating the potential effect of the antidepressant-like fractions of edulis fo. edulis and neuropharmacological mechanisms responsible for this action. To conduct this study used male Swiss mice (2 months old, weighing 30-35 g). The animals received the aqueous extract of the leaves of the two species of Passiflora: edulis fo. edulis (100, 300, 1000 mg / kg) and fractions ethyl acetate, butanol and aqueous waste (25, 50, 75, 100 mg / kg) and edulis fo. flavicarpa (30, 100, 300, 1000 mg / kg) or saline by gavage 60 minutes prior to the maze tests at high cross the open field test, test forced swim test and sedation induced by thiopental. To investigate the mechanism of action of the activity of antidepressant type of fractions the following drugs were used: PCPA (inhibitor of 5-HT synthesis) AMPT (inhibitor of catecholamine synthesis), DSP-4 (noradrenergic neurotoxin) and Sulpiride (antagonist selective dopamine D2 receptor). They were used as a standard positive control, fluoxetine and nortriptyline. The results of the phytochemical profile show very different characteristics to the aqueous extract of the varieties of Passiflora edulis "flavicarpa" and "edulis". The aqueous extracts of both varieties of Passiflora edulis share anxiolytic activity type (edulis fo. edulis 300 mg/kg; edulis fo. flavicarpa 300 and 1000 mg/kg) and antidepressant (edulis fo. edulis 300 mg/kg; edulis fo flavicarpa 1000 mg/kg), while the effect hipolocomotor/sedative was only seen for edulis fo. edulis (1000 mg/kg). Both fractions ethyl acetate, butanol aqueous extract edulis fo. edulis showed activity type antidepressant at a dose of 50 mg/kg in the forced swim test. The data suggest that the effect of antidepressant-like fractions edulis fo. edulis involves catecholaminergic and serotonergic neurotransmission, particularly dopaminergic, there is seen that pre-treatment DSP-4 is not affected antidepressant action of fractions as was dependent activation of dopamine D2 receptors.

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