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G Protein Activation by Endomorphins in the Mouse Periaqueductal Gray MatterNarita, Minoru, Mizoguchi, Hirokazu, Narita, Michiko, Dun, Nae J., Hwang, Bang H., Endoh, Takashi, Suzuki, Tomohiko, Nagase, Hiroshi, Suzuki, Tsutomu, Tseng, Leon F. 01 January 2000 (has links)
The midbrain periaqueductal gray matter (PAG) is an important brain region for the coordination of μ-opioid-induced pharmacological actions. The present study was designed to determine whether newly isolated μ-opioid peptide endomorphins can activate G proteins through μ-opioid receptors in the PAG by monitoring the binding to membranes of the non-hydrolyzable analog of GTP, guanosine-5'-O-(3-[35S]thio)triphosphate ([35S]GTPγS). An autoradiographic [35S]GTPγS binding study showed that both endomorphin-1 and -2 produced similar anatomical distributions of activated G proteins in the mouse midbrain region. In the mouse PAG, endomorphin-1 and -2 at concentrations from 0.001 to 10 μM increased [35S]GTPγS binding in a concentration-dependent manner and reached a maximal stimulation of 74.6 ± 3.8 and 72.3 ± 4.0%, respectively, at 10 μM. In contrast, the synthetic selective μ-opioid receptor agonist [D-Ala2,NHPhe4,Gly-ol]enkephalin (DAMGO) had a much greater efficacy and produced a 112.6 ± 5.1% increase of the maximal stimulation. The receptor specificity of endomorphin-stimulated [35S]GTPγS binding was verified by coincubating membranes with endomorphins in the presence of specific μ-, δ- or κ-opioid receptor antagonists. Coincubation with selective μ-opioid receptor antagonists β- funaltrexamine or D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Phe-Thr-NH2 (CTOP) blocked both endomorphin-1 and-2-stimulated [35S]GTPγS binding. In contrast, neither δ- nor κ-opioid receptor antagonist had any effect on the [35S]GTPγS binding stimulated by either endomorphin-1 or -2. These findings indicate that both endomorphin-1 and -2 increase [35S]GTPγS binding by selectively stimulating μ-opioid receptors with intrinsic activity less than that of DAMGO and suggest that these new endogenous ligands might be partial agonists for μ-opioid receptors in the mouse PAG.
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Direction-sensitive dark matter search with a gaseous micro time projection chamber / 微細構造を用いた三次元ガス飛跡検出器による方向に感度を持つ暗黒物質探索実験Nakamura, Kiseki 24 March 2014 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第18074号 / 理博第3952号 / 新制||理||1569(附属図書館) / 30932 / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)教授 谷森 達, 教授 鶴 剛, 准教授 市川 温子 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM
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エレベーターかご横振動のアクティブ制振技術に関する研究宇都宮, 健児 24 September 2015 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第19306号 / 工博第4103号 / 新制||工||1633(附属図書館) / 32308 / 京都大学大学院工学研究科マイクロエンジニアリング専攻 / (主査)教授 松原 厚, 教授 松野 文俊, 教授 藤本 健治 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM
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Simulation Study on an Electron-Tracking Compton Camera for Deep Gamma-ray Burst Search / 電子飛跡検出型コンプトンカメラシミュレーションによるガンマ線バースト深探査Sawano, Tatsuya 23 March 2017 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第20172号 / 理博第4257号 / 新制||理||1612(附属図書館) / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)教授 谷森 達, 教授 永江 知文, 教授 鶴 剛 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM
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Endomorphins Decrease Heart Rate and Blood Pressure Possibly by Activating Vagal Afferents in Anesthetized RatsKwok, Ernest H., Dun, Nae J. 24 August 1998 (has links)
Endomorphin 1 (10, 30, 100 nmol/kg) administered intravenously (i.v.) to urethane-anesthetized rats consistently and dose-dependently lowered heart rate (HR) and mean arterial pressure (MAP); the decrease in blood pressure recovered faster as compared to the HR. The effects of endomorphin 2 were qualitatively similar. Naloxone (2 mg/kg, i.v.) completely antagonized the bradycardia and hypotension caused by endomorphin 1. Pretreatment of the rats with atropine methylnitrate, atropine sulfate (2 mg/kg, i.v.) or bilateral vagotomy nearly abolished the bradycardia and attenuated the hypotensive effect of endomorphin 1. Our studies suggest that the bradycardia effect following systemic administration of the new opioid peptide may be explained by activation of vagal afferents and the hypotensive effect may be secondary to a reduction of cardiac output and/or a direct vasodilation.
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Croissance cristalline de cristaux scintillateurs de LGSO et de grenats à partir de l’état liquide par les techniques Czochralski (Cz) et micro-pulling down (μ-PD) et leurs caractérisations / Growth from melt by micro-pulling down (µ-PD) and Czochralski (Cz) techniques and characterization of LGSO and garnet scintillator crystalsKononets, Valerii 15 December 2014 (has links)
Des lots de scintillateurs orthosilicates et grenats dope terres rares ont été cristallisés par les méthodes micro-pulling down (μ-PD) et Czochralski. Pour la première fois des fibres Lu2xGd2 2xSiO5 dopées Ce (LGSO:Ce) (x = 0.5) ont été tirées par la méthode micro-pulling down (μ-PD). Dans le but de déterminer la concentration optimale de l'ion activateur avec les meilleurs paramètres de scintillation, la concentration du cérium dans le liquide a été variée dans l'intervalle 0.01-1.5 at%. La distribution spatiale des cations le long des cristaux LGSO :Ce tirés par la méthode de la micro-pulling down a été étudiée par microscopie à champ proche et microscopie Confocale à travers l'excitation du Ce3+ sur les sites cristallographiques du CeO6. Des fibres de composition Lu3A15O12 (LuAG) non dopées et dopées Ce3+ et Pr3+, des matrices mixtes (Lu, Y)3A15O12 (LuYAG) et Y3A15O12 (YAG) dopés Ce3+ ont été fabriqués pour évaluer les possibilités de développer un calorimètre dual-readout pour fonctionner dans le Grand collisionneur de hadrons du CERN. Les cristaux LuAG ont été choisis dans le but de détecter la scintillation (ion activateur) et les radiations Chernkov. Pour confirmer l'amélioration de la qualité des fibres cristallines à travers les conditions de croissance cristalline, nous avons réalisé des mesures d'atténuation le long des fibres. La bonne reproductivité des fibres a été vérifiée par des tests faisceau en conditions de calorimètre. Nous avons étudié la structure et la scintillation dans les cristaux appartenant à la solution solide Y3(Al1-xGax)5O12 :Ce. Les cristaux ont été tirés à partir de l'état liquide par la méthode Czochralski. La distribution des cations de la matrice a été étudiée. L'effet de la substitution du Al/Ga dans Y3(Al1-xGax)5O12 :Ce sur le rendement de scintillation a été déterminé. Le rendement de scintillation a atteint 130 % par rapport au grenat aluminium-yttrium dopé Ce. L'évolution des propriétés de luminescence en fonction de la substitution al/Ga a été étudiée / A set of rare earth orthosilicate and garnet scintillators were grown by the micropulling down (μ-PD) and Czochralski methods. Ce-doped Lu2xGd2 2xSiO5 (LGSO:Ce) fibers were grown by the micro-pulling down (μ-PD) method for the first time. In order to determine the optimal activator concentration with regard to the best scintillating parameters, cerium concentration in the melt was varied within 0.01-1.5 at.%. A set of results on optical and scintillation characteristics of the grown fibers with the different activator content was determined and discussed. Distribution of Gd3+ and Ce3+ in LGSO:Ce structure was compared to the Czochralski grown crystals. Spatial distribution of cations across LGSO:Ce scintillation shaped crystals grown by the micro-pulling-down method is studied using wide-field microscopy under simultaneous excitation of both cerium-related centers and confocal microscopy under selective excitation of Ce3+ in CeO6 crystallographic sites. Undoped fibers of Lu3Al5O12 (LuAG) and doped by Ce3+, Pr3+, mixed (Lu,Y)3Al5O12 (LuYAG) and Y3Al5O12 (YAG) both doped by Ce3+ were produced to evaluate a possibility of their potential use in the new dual-calorimeter planned to operate in the upgraded Large Hadron Collider in CERN. The choice of grown crystals was made to detect scintillation (activated materials) and Cherenkov radiation (LuAG). Growth conditions for the improvement of fibers quality were selected basing on measurements of attenuation length of the fibers. The activator segregation coefficient in LuAG:Ce and LuYAG:Ce fibers was evaluated by the cathodoluminescence measurements. The effect of annealing and radiation damage was studied. The good productivity of the grown fibers was verified on the test beam calorimeter. Structure and scintillation yield of Y3(Al1 xGax)5O12:Ce solid solution crystals are studied. Crystals are grown from melt by the Czochralski method. Distribution of host cations in crystal lattice is determined. The trend of light output at Al/Ga substitution in Y3(Al1-xGax)5O12:Ce is determined. Light output in mixed crystals reaches 130% comparative to Ce-doped yttrium–aluminum garnet. The evolution of luminescence properties at Al/Ga substitution is studied
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Ειδικές κατηγορίες πολλαπλοτήτων επαφής RiemannΜάρκελλος, Μιχαήλ 28 August 2008 (has links)
Στη μεταπτυχιακή αυτή διπλωματική εργασία, αρχικά εισάγουμε τις έννοιες των μετρικών πολλαπλοτήτων σχεδόν επαφής και των μετρικών πολλαπλοτήτων επαφής,
δίνοντας και μερικά παραδείγματα από κάθε κατηγορία. Στη συνέχεια, αναφέρουμε και
αποδεικνύουμε λεπτομερώς μερικές βασικές γεωμετρικές ιδιότητες που χαρακτηρίζουν τις μετρικές πολλαπλότητες επαφής και, οι οποίες, εμπλέκουν τον τανυστή καμπυλό-
τητας. Τέλος, δίνεται έμφαση σε ειδικές κατηγορίες μετρικών πολλαπλοτήτων επαφής που παρουσιάζουν ιδιαίτερο γεωμετρικό ενδιαφέρον και, κυρίως, είναι: πολλαπλότητες K- επαφής, πολλαπλότητες του Sasaki, (κ, μ) – πολλαπλότητες επαφής και μετρικές πολλαπλότητες Η – επαφής. / In this Master Thesis, we initially introduce the notions of almost contact metric manifolds and contact metric manifolds, giving some examples from each category. In sequel, we mention and prove explicitly some basic geometric properties of
contact metric manifolds, which involve the curvature tensor. Summarizing, we focus on special classes of contact metric manifolds which have particular geometric interest and,
mainly, are: K – contact manifolds, Sasakian manifolds, (κ, μ) – contact manifolds and
H – contact metric manifolds.
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Agrotóxicos em doces de frutas em pasta: determinação de resíduos por μlc-qtrap-ms/ms e estudo de estabilidade / Pesticides in fruit jams: residues determination by μlc-qtrap-ms/ms and stability studyReichert, Bárbara 24 July 2015 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This work presents multi-method for pesticide residues determination in fruit
jams. Slurries of the fruit jams and ultrapure (u.p.) water were prepared to yield
homogeneous samples and to facilitate the sample handling. The modified
QuEChERS method was used for the sample preparation. Due the high detectability
of the micro flow liquid chromatography triple quadrupole-linear ion trap mass
spectrometry equipment (μLC-QTRAP-MS/MS) and to minimize the matrix effect (%)
the acetonitrile extracts were diluted 30-fold before analysis. The method validation
was performed analyzing spiked samples at the concentrations of 9 and 45 μg kg-1
(n=5). The method met validation criteria of 70 120% recovery and relative standard
deviation (RSD) ≤ 20% for 93% (99) of the 107 pesticides evaluated. The reporting
limit (RL) was 9 and 45 μg kg-1 for, respectively, 66% and 26% of the analytes, 5% of
the compounds did not fulfill the requirements for validation and 3% were not
detected at the studied concentrations. The validated method was applied to the
analysis of 51 different fruit jam samples from Brazil and from Spain. Pesticide
residues were detected in 80% of the samples, 51% of which contained at least one
pesticide at concentration higher than 10 μg kg-1. Moreover, the stability of five
pesticides was evaluated in the preparation of home-made fruit jams from spiked
fruits. Thereunto, five types of fruits (orange, apple, strawberry, pear and peach, with
n=2 for each type of fruit) were grinded and spiked at 500 μg kg-1 with a mixture of
carbendazim, chlorpyrifos, imidacloprid, iprodione and propargite. Home-made jams
were prepared with these spiked samples by cooking, over medium heat, the grinded
spiked fruit with sugar and u.p. water (ratio, 5:5:2, w/w/w), in an open pan for 30 min.
The modified QuEChERS extraction method was applied either to blank fruits, to the
fruits spiked at 500 μg kg-1 and to the home-made jams (prepared from spiked fruits
at 500 μg kg-1). The extracts of home-made jams and blank fruits were analyzed by
liquid chromatography quadrupole-time of flight mass spectrometry (LC-QTOF-MS)
to ascertain the occurrence of the known metabolites of the spiked pesticides and to
determine the number of co-extracted matrix components from the fruits and from the
jams. All samples were also analyzed by μLC-QTRAP-MS/MS for estimation of the
pesticides processing factors. So the pesticide concentrations found in the spiked
fruits were compared to the concentrations found in the home-made jams (pesticide
concentration measured in the jams/pesticide concentration measured in the raw
fruits). / Este trabalho apresenta um método multirresidual para determinação de resíduos de
agrotóxicos em doces de fruta em pasta. Para obter-se amostras homogêneas e de fácil
manipulação preparou-se uma mistura (slurry) dos doces de frutas e água ultrapura (u.p.). O
preparo das amostras foi feito utilizando o método QuEChERS modificado. Com o objetivo
de diminuir o efeito matriz (%) das amostras e pela alta detectabilidade do equipamento de
cromatografia de micro vazão a líquido acoplada à espectrometria de massas híbrida triplo
quadrupolo-armadilha de íons linear (μLC-QTRAP-MS/MS) os extratos de acetonitrila foram
diluídos na razão de 1:30 (v/v) antes da análise. A validação do método analítico foi feita
pela análise de amostras de doces de uva fortificadas nas concentrações de 9 e 45 μg kg-1
(n=5). Dos 107 agrotóxicos avaliados 93% (99) obtiveram recuperações de 70 a 120% e
desvio padrão relativo (RSD) ≤ 20%. Os limites de notificação (RL) foram de 9 e 45 μg kg-1
para, respectivamente, 66% e 26% dos agrotóxicos avaliados, 5% dos compostos não
alcançaram os pré-requisitos necessários para a validação e 3% não foram detectados nas
concentrações estudadas. Após a validação do método, foram analisadas 51 amostras de
doces de frutas provenientes do Brasil e da Espanha. Em 80% amostras foram detectados
resíduos de agrotóxicos, 51% destas continham no mínimo um agrotóxico em concentração
maior que 10 μg kg-1. Além disso, avaliou-se a estabilidade de cinco agrotóxicos no preparo
de doces de frutas caseiros. Para isso, cinco tipos de frutas (laranja, maçã, morango, pera e
pêssego, com n=2 para cada tipo de fruta) foram trituradas e fortificadas com uma mistura
de carbendazim, clorpirifós, imidacloprido, iprodiona e propargito a 500 μg kg-1. Essas
amostras foram utilizadas no preparo de doces de frutas caseiros. Para isso, as frutas
trituradas e fortificadas foram cozidas com açúcar e água u.p. (proporção de 5:5:2, m/m/m)
em panela aberta sob fogo médio durante 30 min. O método QuEChERS modificado foi
aplicado às frutas não fortificadas, às frutas fortificadas (500 μg kg-1) e aos doces de frutas
caseiros (preparados com frutas fortificadas a 500 μg kg-1). Os extratos dessas amostras
foram analisados por cromatografia a líquido acoplada à espectrometria de massas híbrida
quadrupolo-de tempo de voo (LC-QTOF-MS), com o objetivo de verificar a presença dos
metabólitos conhecidos dos agrotóxicos e determinar o número de componentes coextraídos
das matrizes. Todas as amostras foram analisadas também por μLC-QTRAPMS/
MS com o objetivo de comparar a concentração dos agrotóxicos nas frutas fortificadas
com as concentrações nos doces de frutas correspondentes. A partir dessa relação foi
possível estimar um fator de processamento (FP) para os agrotóxicos no preparo dos doces
de frutas caseiros (concentração do agrotóxico no doce de fruta/concentração do agrotóxico
na fruta fortificada).
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Rôle des récepteurs μ-opioïdes dans l’induction de la néoglucogenèse intestinale observée lors d’un régime hyperprotéique / Role of Mu opioid receptors in induction of intestinal glucose production observed on high-protein dietsDuraffourd, Céline 20 December 2010 (has links)
Une alimentation HP permet une importante diminution de la prise alimentaire, chez l’Homme et l’animal, par rapport à une alimentation STD. Les précédents travaux du laboratoire montrent que le mécanisme d’action des protéines implique une induction de la PIG chez le rat en période post-absorptive. Ce glucose, libéré et détecté dans la veine porte, permet l’activation de noyaux hypothalamiques impliqués dans la régulation des sensations de satiété. L’objectif de ce travail consistait à mettre en évidence le type de peptides pouvant induire la PIG en régime HP et d’essayer de découvrir leur mécanisme d’action. L’activité de la Glc6Pase et de l’expression des protéines Glc6Pase et PEPCK ont été quantifiées chez des rats nourris en régime STD ou HP et perfusés avec des perfusions d’acides aminés, de peptides µ-opioïdes et des solutions de di- ou tri-peptides. Les résultats montrent que le même mécanisme d’action est utilisé par les protéines et les antagonistes µ-opioïdes pour induire la PIG. Des expériences de dénervation portale et une étude immunohistochimique ont démontré la présence de récepteurs µ-opioïdes dans la veine porte probablement impliqués dans cette induction. Des perfusions de di ou tri-peptides chez le rat ont démontré que la PIG était induite par tous les di ou tri-peptides testés. L’étude phénotypique de la souris KO µ-opioïde nourrie en régime STD, HP ou ayant subi des perfusions portales de di ou tri-peptides, ont confirmé que la PIG pouvait être induite par des di ou tri-peptides et que leur mécanisme d’action nécessitait la présence de récepteurs µ-opioïdes. Cette étude suggère que tous les di- ou tri-peptides produits par la dégradation des protéines pourraient induire la PIG par un mécanisme dépendant des récepteurs µ-opioïdes / Protein feeding promotes an important decrease of food intake in humans and animals, compared on chow diet. Previous data show that this mechanism implicates intestinal glucose production (IPG) induction in rat during the post-absorptive time. Glucose released and detected into the portal vein produces an activation of hypothalamic nuclei implicated in the regulation of satiety sensations. The aim of this study was to highlight peptides which could induce IPG on HP diet and try to discoverer them mechanism. Quantification of Glc6Pase and protein expression of Glc6Pase and PEPCK were assessed in rats fed on chow or HP diet and infused with amino acids, µ-opioïd peptides and di- or tri-peptides. Our results show that the same mechanism is shared by both proteins and µ-opioïd antagonists to induce IGP. Experiments of portal vein denervation and an immunochemistry study showed that µ-opioïd receptors are present in the portal vein, probably implicated in this induction. Di or tri-peptides infusions in rat exhibited that the IGP was induced by all tested di or tri-peptides. Phenotypic study of µ-opioid mice fed on chow, HP diet or having undergone portal vein infusions of di or tri-peptides, confirmed that IGP could be induced by di or tri-peptides and their mechanism takes place with µ-opioïd receptors. This study suggests that all di or tri-peptide produced by protein degradation could induce IGP by a µ-opioïd receptor-dependent mechanism
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Contribution de la microarchitecture osseuse et de son hétérogénéité au comportement mécanique vertébral : étude ex-vivo à partir de vertèbres humaines l3Wegrzyn, Julien 03 September 2010 (has links) (PDF)
L'ostéoporose est une maladie du squelette caractérisée par une dégradation de la qualité osseuse conduisant à une majoration du risque fracturaire. Le seul examen permettant actuellement de prédire ce risque est l'ostéodensitométrie à double rayonnement X (DXA) par la mesure de la densité minérale osseuse (DMO). Cependant, la DMO seule ne rend compte que de 40 à 70% de la variation de la résistance mécanique osseuse. Les 3 buts ce travail étaient : 1/ d'évaluer les rôles respectifs de la microarchitecture corticale et trabéculaire dans le comportement mécanique vertébral, 2/ d'évaluer le rôle propre de l'hétérogénéité de la microarchitecture trabéculaire et 3/ de décrire le comportement mécanique vertébral post-fracturaire et d'en identifier les déterminants. Nous montrons que la mesure de l'épaisseur de la corticale antérieure et de son rayon de courbure ainsi que la détermination de la variation régionale de la microarchitecture trabéculaire améliorent significativement la prédiction du risque fracturaire. Il existe une variation marquée du comportement mécanique vertébral après une fracture de grade 1 de Genant. La microarchitecture osseuse, et non la masse osseuse, explique les propriétés mécaniques vertébrales plastiques et élastiques post-fracturaires.
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