It has been reported that opioid receptor activation mimics ischemic preconditioning, which may protect the heart from the development of infarction. Toll-like receptor 4 (TLR-4) during infarction stimulates cytokine production leading to inflammation and injury of the heart tissue. Our aim was to study the effect of morphine in vitro on the viability and oxidative state of H9c2 cells (rat cardiomyoblasts) and the role of TLR-4 during oxidative stress. Our experiments showed that pretreatment with morphine before tert-butylhydroperoxide (t-BHP)-, 2,2'-bipyridyl (BP)- and lipopolysaccharide (LPS)-induced oxidative stess had protective effect on the viability of H9c2 cells and markedly reduced the production of reactive oxygen species (ROS). The protective effect of morphine was diminished after naloxone treatment, which confirms the role of opioid receptors in preconditioning. TLR-4 inhibition by TAK-242 pretreatment and silencing TLR-4 by RNA interference resulted in a partial increase in cell viability but significant attenuation of ROS production after t-BHP and BP treatment. The action of LPS was reduced in response to TLR-4 silencing. Interestingly, naloxone pretreatment and suppression of TLR-4 markedly alleviated oxidative stress and resulted in a significant improvement of cell viability. We...

Le Modèle Standard de la physique des particules a jusqu’alors extrêmement bien réussi à décrire les particules élémentaires et leurs interactions. Malgré cela, il demeure toujours des questions ouvertes. La possibilité de répondre à ces questions grâce la Supersymétrie est actuellement à l’étude dans les collisions proton-proton à 13 TeV dans le cadre de l’expérience ATLAS au LHC. Cette thèse présente la recherche de la production de paires de particules colorées dans ATLAS, ces dernières se désintégrant en paires de jets. Pour ce faire, les données de 2016, 2017 et 2018 ont été utilisées. De telles particules échappent aux recherches standards de la Supersymétrie du fait de l’absence d’énergie transverse manquante dans l’état final. Deux signatures furent considérées, la désintégration de stops via des couplages violant la R-parité et la production de sgluon, le partenaire scalaire du gluino. En l’absence de signal, une amélioration de 200 GeV sur la masse maximum exclue est attendue. Le HL-LHC augmentera la luminosité intégrée délivrée afin de nous permettre de rechercher des particules plus massives et d'améliorer les mesures de précision du Modèle Standard. La luminosité instantanée augmentera d’un facteur 5 et une luminosité intégrée de 4000 fb⁻¹ devrait pouvoir être atteinte à la fin du LHC en 2037.Cette thèse présente également une étude des perspectives de mesure des couplages du Higgs au HL-LHC effectuée à l’aide de SFitter. Il est démontré que dans le cadre des Delta et d’une EFT, l’augmentation de la luminosité génère une amélioration de la précision de la mesure des couplages. Finalement, le Détecteur de temps fortement segmenté, qui sera installé dans ATLAS au HL-LHC, est présenté. La simulation de ce détecteur a été développée pour prendre en compte la résolution temporelle du détecteur et fut utilisée pour optimiser sa géométrie. Les performances de ce détecteur ont été étudiées, plus de 80 % des traces ont leurs temps correctement associés avec une résolution de 20 ps avant irradiation de 50 ps après. En utilisant les informations temporelles, l’isolation des électrons peut être amélioré de 10 %. / The Standard Model of particle physics has been extremely successful in describing the elementary particles and their interactions. Nevertheless, there are open questions that are left unanswered. Whether supersymmetry can provide answers to some of these is being studied in 13 TeV proton-proton collisions in the ATLAS experiment at the LHC. In this thesis a search for pair produced colored particles in ATLAS decaying into pairs of jets using data from 2016, 2017 and 2018 is presented. Such particles would escape standard Supersymmetry searches due to the absence of missing transverse energy in the final state. Stops decaying via a R-parity violating coupling and sgluon, scalar partners of the gluino, were considered. In the absence of a signal, an improvement of 200 GeV on the limit on the stop mass is expected. The HL-LHC will increase the integrated luminosity delivered to probe even higher mass ranges as well as improving the precision of Standard model measurements. The instantaneous luminosity will be increased by a factor 5 and an integrated luminosity of 4000 fb⁻¹ should be reached by the end of the LHC in 2037.A study of the Higgs coupling measurement prospects at the HL-LHC using SFitter is performed. Using the Delta and EFT framework shows that the increase in luminosity will result in a significant improvement of the precision of the measurement of the couplings. The High granularity timing detector detector will be installed in ATLAS for the HL-LHC. A simulation of the detector that takes into account the timing resolution was developed and used to optimize its layout. The detector performance was studied. More than 80 % of the tracks have their time correctly reconstructed with a resolution of 20 ps before irradiation and 50 ps after. Using the timing information, the electron isolation efficiency is improved by 10 %.

Práce se zabývá zarovnáváním excitabilních buněk na multielektrodových polích. Nejprve bylo analyzováno zarovnávání excitabilních buněk. Byly použity embryonální neurony z hippocampusu potkanů a HL-1 buňky, které jsou odvozeny z AT-1 linie nádorových myších atriálních kardiomyocytů. Zarovnávání bylo testováno na drážkovaných površích a na površích s materiály s různou buněčnou afinitou. Bylo prokázáno, že na drážkových površích se ve směru drážek zarovnávají neurony i HL-1 buňky, ale na površích s různou chemickou affinitou se zarovnávají pouze neurony. Dále byly vyrobeny vlastní multielektrodová pole, na těchto multielektrodových polích byly kultivovány HL-1 buňky a byl změřen a analyzován akčních potenciál HL-1 buněk. Cílem bylo prokázat, že je možné měřit akční potenciál na vyrobených multielektrodových polích. Pro zarovnání buněk na multielektrodovém poli bylo vyrobeno speciální multieletrodové pole s uniformním povrchem. Toto multielektrodové pole je nazýváno planární multielektrodové pole. Planární multielektrodové pole bylo vyrobeno speciálním vyrobním procesem. Vrstvy planárního multielektrodového pole byly deponovány na pomocný substrát v opačném pořadí. Pomocný substrátem pro depozici byla křemíková deska, na který byla nadeponována další pomocná vrstva zlata. Horní izolační vrstva planárního multielektrodové pole byla deponována jako první a nejspodnější vrstva substrátu byla nadeponována jako poslední. Planární multielektrodové pole i s pomocnou zlatou vrstvou bylo strhnuto s křemíku díky nízké adhezi zlata ke křemíku a planární multielektrodové pole se otočilo vzhůru nohama. Pomocná zlatá vrstva byla odstraněna mokrým leptadlem a tím bylo planární multielektrodové pole dokončeno. Na planárním multielektrodovém poli byly zarovnány HL-1 buňky do pruhů chemickou metodou pomocí kombinace otisku adhezní látky a následným potažení neotisklých ploch anti-adhezní látkou. Elektrofyziologické vlastnosti zarovnaných HL-1 buněk byly změřeny pomocí planárního multielektrodového pole. Tímto experimentem byla představena výrobní technologie pro výrobu planárních multielektrodových polí a toto planární multielektrodové pole bylo úspěšně testováno pro zarovnání HL-1 buněk na jeho povrchu kombinací otisku adhezní látky a potahování antiadhezivním činidlem.

Le complexe d'accélérateurs du grand collisionneur de hadrons (le Large Hadron Collider - LHC) sera mis à jour lors du long arrêt de la période LS3 en 2023-2025 pour passer à la phase de haute luminosité (HL-LHC). La luminosité instantanée sera multipliée par 5 pour atteindre 7.5×10³⁴ cm⁻²s⁻¹, ce qui correspond à environ 200 collisions inélastiques par croisement de paquets comparé aux 50 par croisement au LHC. Pendant le fonctionnement du HL-LHC, afin d'atteindre une haute précision dans les études des processus physiques du modèle standard et les recherches de nouvelle physique, le collisionneur à protons devra fournir une luminosité intégrée de l’ordre 400 fb⁻¹ par an pendant une dizaine d’années soit 4000 fb⁻¹ escomptées. Ceci représente un ordre de grandeur supérieur à l'ensemble de la période du LHC. Le détecteur interne (Inner Detector) ATLAS actuel ne sera pas en mesure de faire face efficacement à l'augmentation du taux d'événements et de la dose de rayonnement. Afin d’obtenir des performances au minimum égales ou supérieures à celles de la phase LHC, et tenant compte d’un environnement plus hostile en termes de radiations et d’empilements d’évènements, il a été décidé d’opérer le remplacement complet du trajectomètre interne ou Inner Tracker (ITk); à cette fin, une technologie tout silicium a été choisie. Cette thèse est axée sur l'étude de nouveaux capteurs pixels planaires fins à bords très minces, basés sur le concept d’utilisation de matrices de diodes à implants dopés n sur un substrat dopé p. Ce choix est motivé par les critères de meilleure performance intrinsèque, de radio-tolérance élevée ainsi qu’un coût de production optimisé pour de grandes surfaces. Dans ce travail, des capteurs de différentes épaisseurs allant de 50 μm à 150 μm dotés de bords actifs et minces ont fait l’objet d’études approfondies notamment lors de leur fonctionnement à haut flux de particules chargées. De nombreuses analyses minutieuses ont été menées pour déterminer leur résolution en position à l’aide d’un télescope de faisceau de haute énergie. Les régions d’impacts sur la zone active des pixels ainsi que sur la région des contours ont été scrutées avant et après leur irradiation. En effet, de nombreux résultats obtenus en faisceau de protons et électrons seront montrés, notamment une étude comparative des différents concepts de matrices de capteurs de pixels planaires lus avec la puce de lecture « FE-I4 » en technologie CMOS 130 nm. Préparant la phase future du LHC, nous montrerons les premiers résultats obtenus avec la nouvelle génération de pixels granulaires. Ces matrices ont été couplées à la nouvelle puce de lecture frontale récemment développée au CERN, utilisant la technologie CMOS 65 nm. Ces capteurs dotés d’ une plus fine granularité de 50×50 μm² , ont un pas optimisé lequel est nécessaire pour maintenir un taux d'occupation aussi bas que possible dans un contexte de multiplicités de particules chargées très élevées. Dans ce travail, une contribution personnelle à l’électronique de lecture sera détaillée, en particulier les études ont été menées sur la puce nommée «Ring-Oscillator» ou moniteur de radiations, développée au laboratoire. On décrira son comportement dynamique en fonction de la température, de la tension nominale et en conditions hautement radiatives (500 MRad). La mise au point d’un nouvel outil de caractérisation de détecteurs pixels a fait l’objet d’un développement important. Grâce à un ensemble basé sur une excitation laser de 1060 nm, il sera possible de disposer d’un système précis et autonome capable de mesurer rapidement les caractéristiques fonctionnelles des matrices de pixels avec une excellente résolution spatiale. Les caractéristiques de cet outil feront l’objet d’une présentation exhaustive. / The Large Hadron Collider (LHC) will go through the accelerator complex upgrade during the LS3 long shutdown in 2023-2025 to move to the High Luminosity phase (HL-LHC). As a result, an instantaneous luminosity will increase sevenfold to 7.5×10³⁴ cm⁻²s⁻¹, corresponding to approximately 200 inelastic collisions per bunch-crossing, whereas the LHC runs resulted in up to 50 collisions per bunch-crossing. During the operation of the HL-LHC, in order to achieve high-precision in studies of Standard Model processes and searches for new physics, about 4000 fb⁻¹ of integrated luminosity be collected, which is of an order of magnitude larger than over the entire LHC period. The present ATLAS Inner Detector (ID) will not be able to efficiently cope with the increased event rate and radiation dose. Due to this fact the complete replacement of the ID is foreseen with fully silicon Inner Tracker (ITk) to provide high tracking performance in harsher environment delivered by the HL-LHC. This thesis is focused on the study of new n+-in-p planar silicon sensors, as a promising option to instrument the ITk pixel layers, considering their radiation hardness and cost-effectiveness. Sensors of different thicknesses ranging from 50 µm to 150 µm of active and slim edge designs have been tested at a high energy particle beam to investigate hit efficiency performance analyzed on the pixel active area and on the edge area before and after irradiation. The test beam results and their comparison for the different designs of the pixel sensors compatible with FE-I4 readout chip are discussed. Also, the first results on test beam characterization of the pixel modules employing a newly developed prototype of readout chip for the ITk, RD53A chip, implemented in 65 nm CMOS technology, were obtained. The sensors with the decreased to 25×100 µm² and 50×50 µm² pixel pitch to maintain the lower level of occupancy at high particle multiplicity were measured. Additionally, the tests of ring oscillators, contained in RD53A chip, which may be used as a monitor of the received radiation dose, were carried out depending on temperature, supplied voltage and irradiation level up to 500 MRad. Finally, the test bench setup for silicon pixel detectors characterization using an infra-red laser has been the subject of an original development in this thesis. The setup was developed in the clean room at Laboratoire de l'accélérateur linéaire (LAL) and it is capable of rapidly measuring the functional characteristics, providing a flexible charge injection with well-defined hit position to characterize the silicon pixel matrixes. The software to control the setup was created using LabVIEW programming environment. The results of the measurements with the FE-I4 module implemented with openings allowing the laser beam passage on a sensor backside are presented in this thesis.

Swelling-activated Cl− current (ICl,swell) is an outwardly-rectifying current that plays an important role in cardiac electrical activity, cellular volume regulation, apoptosis, and acts as a potential effector of mechanoelectrical feedback. Persistent activation of ICl,swell has been observed in models of cardiovascular disease. We previously suggested sphingosine-1-phosphate (S1P) activates volume-sensitive Cl- current (ICl,swell) by ROS-dependent signaling. S1P and its analog, FTY720 (fingolimod), primarily act via G-protein coupled receptors (S1PR; S1PR1-3 in heart), but several intracellular S1P ligands are known. We investigated how these agents regulate ICl,swell. ICl,swell was elicited by bath S1P (500 nM), FTY720 (S1PR1,3 agonist; 10 μM), and SEW2871 (S1PR1 agonist; 10 μM) and was fully inhibited by DCPIB, a specific blocker. These data suggested role of S1PR in activation of ICl,swell. Surprisingly, neither CAY10444 (S1PR3 antagonist; 10 μM) nor VPC23019 (S1PR1,3 antagonist; 13 μM) blocked FTY720-induced ICl,swell. Also, gallein a pan Gbeta-gamma inhibitor, failed to block the S1P-induced current. Moreover, 100 nM FTY720 applied via the pipette evoked a larger, faster activating current than 10 μM bath FTY720. Similarly, 500 nM S1P gave larger, faster activating ICl,swell when added to the pipette than when added in the bath. In contrast to FTY720, bath S1P-induced ICl,swell was blocked by CAY10444, but a 3-fold higher concentration failed to eliminate the response to pipette S1P, and VPC23019 failed to suppress bath and pipette S1P-induced currents. Taken together, inconsistencies in the responses to S1PR agents and the greater sensitivity to pipette than bath S1P and FTY720 support the notion that intracellular ligands rather than sarcolemmal S1PR activated ICl,swell. Next we tested if S1P and FTY720, like osmotic swelling, require both NADPH oxidase and mitochondrial ROS production to evoke ICl,swell. S1P- and FTY720-induced ICl,swell were blocked by rotenone but were insensitive to gp91ds-tat, suggesting only mitochondrial ROS production was needed. One possibility is that S1P and FTY720 elicit ICl,swell by binding to mitochondrial prohibitin-2, an S1P ligand whose knockdown augments mitochondrial ROS productions. These data suggest ICl,swell may be activated by S1P accumulation in ischemia-reperfusion and CHF. Understanding S1P-signaling that elicits ICl,swell may provide insight into electrophysiological mechanisms of cardiac pathology and help identify novel targets for therapy.

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

A infestação por carrapatos é uma das principais parasitoses que afetam a bovinocultura prejudicando a saúde do animal por meio de hábito hematófago, além de gerar perdas econômicas para o seu controle, sendo o uso de carrapaticidas o principal método utilizado. O uso negligenciado destes produtos induz a geração de resistência tornando necessário o desenvolvimento de métodos alternativos, como a imunização por vacinas e o uso de probióticos. Probióticos são alimentos funcionais, compostos de micro-organismos vivos, que quando ingeridos em doses adequadas e com frequência, conferem diversos efeitos benéficos à saúde do hospedeiro por meio de diferentes mecanismos de ação. Desta forma, o presente trabalho teve como objetivo avaliar o efeito imunomodulador e carrapaticida de micro-organismos probióticos em bovinos da raça Girolando. Para tanto, durante 154 dias, foram estudados 30 animais distribuídos em 06 grupos e submetidos a diferentes tratamentos, a saber: Grupo A (controle) os animais não receberam tratamento específico; Grupo B (efeito vacina) nos dias inicial, 14 e 28 os animais foram imunizados com a proteína rGST-Hl; Grupo C (efeito probiótico EEL) os animais receberam, durante 70 dias, uma dose diária de 10 mL, da preparação probiótica EEL; Grupo D (efeito vacina + probiótico EEL) nos dias inicial, 14 e 28 os animais foram vacinados e receberam durante 70 dias, 10 mL da preparação probiótica EEL; Grupo E (efeito probiótico PT) os animais receberam, durante 70 dias, uma dose de 10 mL da preparação probiótica ProbioTick e Grupo F (efeito vacina + probiótico PT) nos dias inicial, 14 e 28 os animais foram vacinados e receberam diariamente, durante 70 dias, 10 mL da preparação probiótica ProbioTick. A cada 14 dias foram realizadas coletas de sangue para avaliação da hemostasia, do estado de anemia e o desenvolvimento da resposta imune humoral. Os resultados demonstraram que os tratamentos não afetaram significativamente a hemostasia, bem como os parâmetros eritrocíticos dos animais. No tocante ao sistema imunológico, verificou-se que os animais tratados com as preparações probióticas apresentaram maior número de linfócitos quando comparado ao grupo controle diferindo estatisticamente no 70º dia, sendo que os percentuais encontrados para os grupos C, D, E e F foram respectivamente de 55,8%; 63,5%; 60,8% e 59,4%. Os animais que foram vacinados (grupo B) e tratados com as preparações probióticas (Grupos D e F), apresentaram níveis superiores de anticorpos totais IgG (72,769; 93,735 e 98,825 mg/dL) e quanto aos anticorpos IgG anti rGST-Hl, os animais dos Grupos D e F tiveram seus valores aumentados quando comparados aos do Grupo B por um período mais prolongado, onde no 98º dia, as densidades ópticas medidas foram de 0,868 e 0,915. Desta forma, conclui-se que as preparações probióticas foram capazes de modular a resposta imunológica dos animais. / Tick infestation is the main parasitic diseases that affect the cattle farming. In addition to impairing the health of the animal by means of a hematophagous habit, it also generates economic losses regarding its control, being the use of acaricides the main method used. Its neglected use has led to cases of resistance, which turn necessary the development of alternative methods such as the immunization with vaccines and the use of probiotics. Probiotics are functional food that contains live microorganisms that when ingested in appropriate amount bring benefits to the hosts through different mode of action. Thus, the present work aimed to evaluate the immunomodulatory and acaricide effect of probiotic microorganisms in Girolando cattle. Therefore, during 154 days, 30 animals were distributed in 6 groups, and submitted to different treatments: Group A (control), the animals did not received any treatment. Group B (vaccine effect), on the initial, 14 and 28 days, the animals were immunized with rGST-H1. Group C (probiotic effect EEL, the animals received, for 70 days, a daily dose of 10 mL of the probiotic EEL preparation. Group D (vaccine + probiotic EEL effect), on the initial, 14 and 28 days, the animals were vaccinated and received for 70 days, 10 mL probiotic preparation EEL. Group E (probiotic effect PT), the animals received, for 70 days, a dose of 10 mL of probiotic preparation ProbioTick and Group F (vaccine + PT probiotic effect), on the initial, 14 and 28 days, the animals were vaccinated and received daily for 70 days, 10 mL ProbioTick. In each 14 days blood samples were collected and exams were performed to evaluate hemostasis, anemia status and development of the immune response. The results showed that the different treatments did not affect hemostasis and the erythrocytic parameters of the animals. Regarding the immune system, the results showed that the animals treated with probiotic preparations presented a higher number of lymphocytes when compared to the control group, differing statistically on the 70th day, being that the percentages found for groups C, D, E and F were respectively 55.8%; 63.5%; 60.8% and 59.4%. In addition, animals treated with the probiotic (Groups D and F) and vaccinated (B) showed higher levels of total IgG antibodies (72.769, 93.735 and 98.825 mg/dL) and as for the IgG anti rGST-H1 antibodies, only the animals in Groups D and F had their values increased for a longer period, where on the 98th day, The optical densities measured were 0.868 and 0.915. Therefore, the probiotic preparations evaluated were able to modulate the imune response of animals.

Electrical potentials exist across the membranes of nearly every cell type in the body. In addition, excitable cells, such as neurons, myocytes and even some endocrine cells elicit electrochemical fluctuations, action potentials (AP), in the cell membrane to initiate cell-to-cell communication or intracellular processes. The basis for the electrical potential is rooted within an array of complex interactions between monovalent ions and their associated membrane channels and transporters that regulate the flux of these charged species across the hydrophobic bilayer. Here, an expansion of our recently published work [1] will serve to explore the modern concepts regarding the origin of the AP as well as to examine the mechanisms by which intracellular calcium ([Ca2+]i) is regulated within the HL-1 mouse cardiac myocyte.

Thesis (M.Sc. (Biochemistry))-- University of Limpopo, 2001 / Refer to document

Atrial natriuretic factor (ANF) is a cardiac hormone that helps maintain cardiovascular homeostasis. ANF secretion is linked to the constitutive, regulated and constitutive-like pathways. Presence of a monensin-sensitive pool that may follow constitutive-like secretion has previously been identified in an isolated atrial perfusion study. The intracellular ANF storage pools linked to each secretory pathway have not been identified. In this study, ANF storage and secretion was characterized in HL-1 atrial cardiomyocytes through the use of pharmacological agents, density gradient and RP- HPLC analysis. Treatment of HL-1 cells with monensin followed by cell fractionation was unsuccessful in identifying the monensin-sensitive pool. RP-HPLC analysis identified presence of low molecular weight ANF in low density gradient fractions that were defined by the presence of organelle markers of Golgi, early endosome, clathrin and corin. Since the monensin-sensitive pool was thought to be of a constitutive-like nature, targeting this pathway with pharmacological inhibitors of clathrin coat vesicle (CCV) formation and endosomal trafficking failed to prevent stimuli-independent secretion. Based on an inability to prevent ANF secretion by targeting the constitutive-like pathway and the presence of low molecular weight ANF in low density gradient fractions, stimuli- independent ANF secretion seems to be through a constitutive pathway.