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1
Ovens, Matthew James. "Further characterisation of substrate, inhibitor and ancillary protein specificity of MCT1, MCT2, MCT4 and MCT6." Thesis, University of Bristol, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.528104.
Анотація:
The MonoCarboxylate Transporter (MCT) family of transmembrane proteins contain 14 members of which 6 have been functionally characterized. Of these characterised MCTs only MCTs 1-4 have been shown to transport lactate. These MCTs also facilitate the movement of pyruvate and ketone bodies across the plasma membrane (PM) in cotransport with a proton. For trafficking to and function at the PM MCTl, MCT3 and MCT4 require association with the monotopic ancillary glycoprotein basigin whereas MCT2 prefers association with embigin. This thesis has investigated the sensitivity of MCTl, MCT2 and MCT4 to the highly potent and selective MCTI inhibitor, ARC155858, discovered by AstraZeneca. Chimeras of MCTI and MCT4 were constructed and expressed in Xenopus laevis oocytes for transport studies to determine their inhibitor sensitivity. These identified a region between transmembrane domains (TMs) 7 and 10 of MCTI with which AR-C155858 binds from the cytoplasmic side. ARC155858 was shown to inhibit MCT2 but sensitivity was found to be dependent on the ancillary protein with which it is associated. Co-expression with embigin decreased the sensitivity of MCT2, but not MCTl, to AR-CI55858. The MCT C-terminus was shown to playa role in the interaction between MCT and ancillary protein which is secondary to interactions between the TM of the ancillary protein and TMs3 and 6 of the MCT. Additional studies were performed to characterise the substrate specificity of the orphan transporter, MCT6. Initial work suggested that products of pyruvate decarboxylation or polymerisation will provide lead compounds in the continuing search for the physiological substrate of MCT6, with formate another potential substrate. During this work it was also discovered that MCTI can catalyse the transport of specific dicarboxylates at low pH.
2
Petit, Jules. "Membrane Tethering in Plant Intercellular Communication : Structure-Function of Multiple C2 domains and Transmembrane Region Proteins (MCTP) at Plasmodesmata ER-PM Membrane Contact Site." Thesis, Bordeaux, 2022. https://tel.archives-ouvertes.fr/tel-03789611.
Анотація:
La multicellularité chez les plantes repose sur une communication intercellulaire qui permette le transfert d'informations à travers l'entièreté de l'organisme. Chez les plantes terrestres, la route principale de ces “conversations cellulaires” est assurée par les plasmodesmes (PD), des canaux nanoscopiques qui traversent la paroi pecto-cellulosique. En effet, ces pores sont impliqués dans la circulation d'une très grande variété de molécules, comme des facteurs de transcription, de l'ARN, des hormones et des métabolites et ceci à tous les stades de la vie végétale, permettant réponses et adaptations à l'environnement. Les PD sont particuliers dans le sens où ils forment une continuité du réticulum endoplasmic (RE), de la membrane plasmique (MP) et du cytoplasme entre les cellules adjacentes. Leur architecture est singulière et consiste en un filament de RE, appelé desmotubule, entouré d'un tube de MP qui, lui, longe la paroi. Les PD sont actuellement décrits comme des sites de contact membranaire, du fait du fort accolement des membranes du RE et de la MP (2 à 10 nm) et de la présence de protéines de jonction qui connectent les deux organelles. Dans la présente étude, nous décrivons au niveau structural et fonctionnel plusieurs membres de la famille des MCTPs (protéine avec de multiples domaines C2 et une région transmembranaire) comme protéines assurant la jonction du RE et de la MP dans les PD. Nous démontrons que ces protéines possèdent les caractéristiques moléculaires nécessaires à l'interaction transitoire avec les lipides anioniques de la MP, via leurs domaines C2, ainsi qu'à l'induction de courbure membranaire au RE, via la région transmembranaire qui agit comme un domaine homologue aux protéines réticulons. Ces données nous ont permis de corréler la fonction des MCTPs à l'architecture et la biogenèse des PD et de réfléchir au rôle du RE à l'intérieur des PD. En conclusion, ce travail a fourni des résultats originaux qui placent les MCTPs comme des protéines centrales dans l'établissement de la structure fine des PD et des fonctions qui y sont associéesPlant multicellularity relies on intercellular communication in order to transmit information from cell to cell and throughout the entire plant body. In land plants, the major line for such cellular conversations is through plasmodesmata (PD) pores, which are nanoscopic membranous tunnels spanning the pecto-cellulosic cell wall. These pores are indeed involved in the transfer of a wide variety of molecules such as transcription factors, RNAs, hormones and metabolites during all stages of plant life, adaptation and responses to their environment. PD are singular amongst other types of intercellular junctions as they provide a direct continuity of the endoplasmic reticulum (ER), the plasma membrane (PM) and the cytosol between neighboring cells. Their architectural organization can be summarized as followed: a thin strand of constricted ER, called desmotubule, is encased in a tube of PM lining the cell wall. PD are seen as a specialized ER-PM membrane contact sites from the very close apposition (2 to 10 nm) of the ER and PM membranes and the presence of tethering elements bridging the two organelles. In this study, we describe the structural organization and function of several members of the MCTP (Multiple C2 domains and Transmembrane region Protein) family which act as ER-PM tethering elements at PD. We show that these proteins possess molecular features capable of transient interaction with anionic lipids of the PM, through their C2 domains, as well as ER membrane shaping, through their transmembrane region which presents homology to a reticulon domain. We further correlate MCTP function with PD architecture and biogenesis, and investigate on the role of the ER inside PD. Altogether, this work provides original data placing MCTPs as core PD proteins that appear to be crucial in the establishment of PD ultrastructure and associated functions
3
Little, L. Nicole. "Characterization of Basigin and the Interaction Between Embigin and Monocarboxylate Transporter -1, -2, and -4 (MCT1, MCT2, MCT4) in the Mouse Brain." UNF Digital Commons, 2011. http://digitalcommons.unf.edu/etd/384.
Анотація:
Basigin and Embigin are members of the immunoglobulin superfamily that function as cell adhesion molecules. Studies of Basigin null mice revealed reproductive sterility, increased pain sensitivity, and blindness. It is thought that the mechanism causing blindness involves misexpression of monocarboxylate transporter 1 (MCT1) in the absence of Basigin. It is known that the transmembrane domain of Basigin interacts with MCT1. In the absence of Basigin, MCT1 does not localize to the plasma membrane of expressing cells and photoreceptor function is disrupted. Studies of the Basigin null mouse brain suggest that MCT1 is properly expressed, which suggests a separate mechanism causes the increased pain sensitivity in these animals, and also that a different protein directs MCT1 to the plasma membrane of expressing cells in mouse brain. Embigin is known to interact with MCT2 in neurons and with MCT1 in erythrocytes. It is not known, however, if Embigin normally interacts with MCT1 in the mouse brain or if Embigin acts to compensate for the lack of Basigin in the Basigin null animals. Therefore, the purpose of this study was to determine if Embigin normally interacts with MCT1, 2, or 4 in the mouse brain and if so, whether the interaction is similar to that between Basigin and MCT1. Expression of Basigin, Embigin, MCT1, MCT2, and MCT4 in mouse brain was assessed via immunoblotting and immunohistochemical analyses. In addition, recombinant protein probes corresponding to the Embigin transmembrane domain were generated for ELISA binding assays using endogenous mouse brain MCTs. It was determined that the proteins in question are rather ubiquitously expressed throughout the mouse brain, and that the cell adhesion molecules Basigin and Embigin may be co-expressed in the same cells as the MCT2 and MCT4 transporter proteins. In addition, it was determined that the Embigin transmembrane domain does not interact with the MCTs. The data therefore suggest that MCTs do not require Basigin or Embigin for plasma membrane expression in mouse brain.
4
Richards, William. "The influence of aging and cardiovascular training status upon monocarboxylate transporters." Columbus, Ohio : Ohio State University, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1133362045.
5
Feringer, Júnior Walter Heinz [UNESP]. "Expressão dos transportadores de monocarboxilatos de equinos e cães." Universidade Estadual Paulista (UNESP), 2017. http://hdl.handle.net/11449/153171.
Анотація:
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
O principal mecanismo de transporte dos íons lactato e H+ em equinos e cães é o complexo transportador formado pelos transportadores de monocarboxilatos, isoformas 1 (MCT1) e 4 (MCT4) juntamente com a proteína auxiliar CD147. Objetivando identificar diferenças entre equinos com desempenho distinto, 16 equinos da raça Brasileiro de Hipismo (BH) foram distribuídos em dois grupos, desempenho inferior (DI, n=8) e desempenho superior (DS, n=8) que foram submetidos a teste de salto incrementai (TSI). Realizou-se biópsia do músculo Gluteus medius para tipificação e análise das expressões das isoformas MCT1, MCT4 e CD147. Amostras sanguíneas foram colhidas para avaliar as expressões MCT1 e CD147 das hemácias. Aplicaram-se testes de normalidade de Shapiro Wilk e homogeneidade de Levene. As medidas morfométricas foram submetidas ao teste de Tukey. Teste “t” de Student não pareado para a comparação das médias dos grupos DI e DS. Aplicou-se correlação de Spearman para as expressões dos transportadores. Para todas as análises utilizou-se p≤0,05. Não houve diferença entre os grupos quanto à frequência de cada tipo de fibra e constatou-se maior quantidade das fibras tipo I em relação às fibras IIA e IIX em todos os equinos avaliados. Não houve diferença entre os pesos moleculares e a expressão das proteínas MCT1, MCT4, e CD147 musculares ou sanguíneas. Houve correlações positivas entre MCT1 vs. CD147 e MCT4 vs. CD147 musculares dos grupos DI e DS. As correlações encontradas foram esperadas uma vez que as isoformas estudadas dependem intimamente da proteína auxiliar CD147 para o transporte. Os equinos BH não apresentaram diferenças nas expressões dos MCT1,4 e CD147, musculares ou sanguíneos, mesmo com níveis de condicionamento diferentes. Com o objetivo de investigar as concentrações de lactato plasmático e das hemácias e avaliar as expressões eritrocitáras do complexo transportador MT1/CD147, 6 cães da raça American Pitbull Terrier (APBT) foram submetidos ao teste de esforço incremental (TEI) em esteira. No final de cada incremento de velocidade foi coletado sangue da veia cefálica. Foram mensuradas concentrações de lactato sanguíneo (LS), plasmático (LP), pH e hematócrito (Ht). A concentração do lactato dentro das hemácias (LH) foi estimada e estabeleceu-se a relação LH:LP. As expressões sanguíneas do complexo MCT1/CD147 foram avaliadas por Western Bloting. Aplicou-se análise de variância de uma via seguido pelo teste de Dunn’s. Para pH e Ht aplicou-se teste t de student para amostras pareadas e a correlação de Pearson foi utilizada para MCT1 e CD147, estabeleceu-se nível de significância P≤0,05. LS, LP e LH e pH não apresentaram diferenças entre si, a relação LH:LP foi próxima de 1 com tendência de aumento. MCT1 e CD147 apresentaram 48 e 59 kDa de peso molecular e 1,27 e 1,05 de unidades ópticas arbitrárias (UOA). Não foram encontradas correlações entre MCT1 e CD147. A grande velocidade de transporte do MCT1/CD147 explica a relação LP:LH próxima de 1, esta velocidade e o mecanismo de arquejo podem explicar os valores de pH constantes. A raça APBT, quando submetidos à atividade física apresentaram tendência de aumento da relação LH:LP e expressam de maneira homogênea o complexo MCT1/CD147.
The central transport mechanism of lactate and H+ ions in horses and dogs is the carrier complex formed by the monocarboxylate, isoform 1 (MCT1) and 4 (MCT4) associated with the ancillary protein CD147. This study aimed to identify possible differences between horses with different performances levels, 16 horses of the Brazilian Sport Horse breed (BH) were distributed in two groups, inferior performance (IP, n = 8) and superior performance (SP, n = 8). A Gluteus medius muscle biopsy was performed for cellular typing and analysis of MCT1, MCT4, and CD147 muscle expressions. By jugular venipuncture, blood samples were collected to evaluate MCT1 and CD147 expressions in the red blood cells (RBC). Normality Shapiro Wilk test and homogeneity of Levene were applied. The morphometric measurements were submitted to the Tukey test, and not paired Student's t-test were applied to compare the mean of the IP and SP groups for all variables and was used Spearman's correlation for isoform expressions, for all analyzes, p≤0.05. There were no differences between the groups regarding the frequency of each type of fiber and a higher number of type I fibers were observed about the IIA and IIX fibers in all groups. There was no difference between molecular weights and expressions of MCT1, MCT4, and CD147 in muscle or blood. There were positive correlations between muscles MCT1 vs CD147 and MCT4 vs CD147 in both groups. The relationships found were expected since the MCT1 and 4 depended on the CD147 ancillary protein for correct functioning. The BH horses do not present differences in the muscle or RBC expressions of MCT1, 4 and CD147, even with different conditioning levels. To investigate plasma and erythrocyte lactate concentrations and to evaluate erythrocyte expression of the MT1/CD147 transporter complex, six dogs of the American Pit Bull Terrier breed (APBT) were submitted to a treadmill incremental effort test (IET). At the end of each increment of speed, blood was collected from the cephalic vein. Concentrations of blood (BL) and plasma lactate (PL), pH and hematocrit (Ht) were measured. The concentration of lactate inside the red blood cells (LC) was estimated and the LC: PL ratio was established, the blood expressions of the MCT1/CD147 transporter complex were evaluated by western blot. Data were submitted to the Shapiro-Wilks normality test, one-way ANOVA and Dunn's test. For pH and Ht, paired Student's t-test was applied, and Pearson's correlation was used for MCT1 and CD147 analysis, for all analyzes, p≤0.05. BL, PL, LC, pH showed no differences, the LC: PL ratio was close to 1 with an increasing tendency. MCT1 and CD147 presented 48 and 59 kDa of molecular weight and 1.27 and 1.05 of arbitrary optical units (AOU). No correlations were found between MCT1 and CD147. The high transport velocity of the MCT1/CD147 could explain the LC: PL ratio close to 1, this velocity plus the grasping mechanism may explain the constant of pH values. The APBT submitted to intense physical activity showed a tendency to increase the LC: PL ratio, and homogeneously express the MCT1/CD147 complex
FAPESP: 11/11080-0
6
Feringer-Junior, Walter Heinz. "Expressão dos transportadores de monocarboxilatos de equinos e cães /." Jaboticabal, 2017. http://hdl.handle.net/11449/153171.
Анотація:
Orientador: Guilherme de Camargo FerrazResumo: O principal mecanismo de transporte dos íons lactato e H+ em equinos e cães é o complexo transportador formado pelos transportadores de monocarboxilatos, isoformas 1 (MCT1) e 4 (MCT4) juntamente com a proteína auxiliar CD147. Objetivando identificar diferenças entre equinos com desempenho distinto, 16 equinos da raça Brasileiro de Hipismo (BH) foram distribuídos em dois grupos, desempenho inferior (DI, n=8) e desempenho superior (DS, n=8) que foram submetidos a teste de salto incrementai (TSI). Realizou-se biópsia do músculo Gluteus medius para tipificação e análise das expressões das isoformas MCT1, MCT4 e CD147. Amostras sanguíneas foram colhidas para avaliar as expressões MCT1 e CD147 das hemácias. Aplicaram-se testes de normalidade de Shapiro Wilk e homogeneidade de Levene. As medidas morfométricas foram submetidas ao teste de Tukey. Teste “t” de Student não pareado para a comparação das médias dos grupos DI e DS. Aplicou-se correlação de Spearman para as expressões dos transportadores. Para todas as análises utilizou-se p≤0,05. Não houve diferença entre os grupos quanto à frequência de cada tipo de fibra e constatou-se maior quantidade das fibras tipo I em relação às fibras IIA e IIX em todos os equinos avaliados. Não houve diferença entre os pesos moleculares e a expressão das proteínas MCT1, MCT4, e CD147 musculares ou sanguíneas. Houve correlações positivas entre MCT1 vs. CD147 e MCT4 vs. CD147 musculares dos grupos DI e DS. As correlações encontradas foram esperadas ... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The central transport mechanism of lactate and H+ ions in horses and dogs is the carrier complex formed by the monocarboxylate, isoform 1 (MCT1) and 4 (MCT4) associated with the ancillary protein CD147. This study aimed to identify possible differences between horses with different performances levels, 16 horses of the Brazilian Sport Horse breed (BH) were distributed in two groups, inferior performance (IP, n = 8) and superior performance (SP, n = 8). A Gluteus medius muscle biopsy was performed for cellular typing and analysis of MCT1, MCT4, and CD147 muscle expressions. By jugular venipuncture, blood samples were collected to evaluate MCT1 and CD147 expressions in the red blood cells (RBC). Normality Shapiro Wilk test and homogeneity of Levene were applied. The morphometric measurements were submitted to the Tukey test, and not paired Student's t-test were applied to compare the mean of the IP and SP groups for all variables and was used Spearman's correlation for isoform expressions, for all analyzes, p≤0.05. There were no differences between the groups regarding the frequency of each type of fiber and a higher number of type I fibers were observed about the IIA and IIX fibers in all groups. There was no difference between molecular weights and expressions of MCT1, MCT4, and CD147 in muscle or blood. There were positive correlations between muscles MCT1 vs CD147 and MCT4 vs CD147 in both groups. The relationships found were expected since the MCT1 and 4 depended on the CD... (Complete abstract click electronic access below)
Doutor
7
Benesch, Franziska. "Regulative Einflüsse auf die Monocarboxylattransporter 1 und 4 im Pansenepithel des Schafes." Doctoral thesis, Universitätsbibliothek Leipzig, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-211226.
Анотація:
Einleitung: Monocarboxylattransporter (MCT) 1 & 4 sind in zahlreichen Geweben als Kotransporter für Monocarboxylate und Protonen beschrieben. Auch im Pansenepithel werden MCT benötigt, um kurzkettige Fettsäuren (SCFA) aus dem Pansenlumen in die Pansenepithelzelle aufzunehmen (MCT4) und um SCFA und deren Metabolite aus der Pansenepithelzelle in das Blut auszuschleusen (MCT1). Die transepitheliale Permeation von SCFA über die Pansenwand ist von enormer Bedeutung, da sie die wichtigste Energiequelle der Wiederkäuer darstellen. Die beteiligten Transportprozesse müssen dementsprechend einer Anpassung an variierende Mengen von SCFA unterliegen. Bisherige Studien bei anderen Spezies deuten auf eine Regulation des MCT1 auf mRNA Ebene über den Peroxisom-Proliferator-aktivierten Rezeptor α (PPARα) hin. Ziele der Untersuchung: Das Ziel dieser Arbeit war herauszufinden, ob MCT1 in ovinen Pansenepithelzellen über PPARα reguliert wird und ob auch MCT4 dieser Regulation unterliegt. Eine gleichzeitige Regulation beider Transporter läge nahe, da sie gemeinsam an der transepithelialen Permeation beteiligt sind. Die Auswirkungen solch einer Regulation auf die Proteinexpression und die Transportleistung der MCT sollte charakterisiert werden. Ebenfalls war das Potenzial der bei erhöhter Kraftfutterfütterung vermehrt anfallenden SCFA Butyrat auf die MCT1 Expression zu untersuchen. Material & Methoden: Aus dem Vorhof von Schafen wurden Pansenepithelzellen gewonnen und entsprechend einer bereits etablierten Methode kultiviert. Nach einer Subkultivierung wurden die Zellen immunzytochemisch mit Antikörpern gegen MCT1, MCT4 und Na+/K+-ATPase untersucht, um deren Lokalisation in den kultivierten Pansenepithelzellen zu bestimmen. Weiterhin erfolgte eine Behandlung mit WY 14.643, einem spezifischen, synthetischen PPARα Agonisten, sowie mit GW 6471, einem Antagonisten des PPARα. Mittels qPCR wurden die relativen mRNA Mengen von MCT1, MCT4, ACO, CPT1A und CACT bestimmt und auf die Referenzgene GAPDH und Na+/K+-ATPase normalisiert. Die Proteinexpression von MCT1 und MCT4 wurde mittels Western Blot bestimmt. Zur funktionellen Quantifizierung wurde der intrazelluläre pH-Wert der Zellen mittels Spektrofluorometrie gemessen und der laktatabhängige Protonentransport als Vergleichswert zwischen den Behandlungen genutzt. Um den MCT-abhängigen Teil des Transportes zu bestimmen, wurde ein spezifischer MCT1 & 4 Inhibitor, die p-Hydroxymercuribenzensulfonsäure (pHMB) eingesetzt. Die Zellen wurden mit Butyrat über einen Zeitraum von 6 und 48 h induziert. Die Erfassung der MCT1 Expression erfolgte mittels semiquantitativer PCR. Ergebnisse: MCT1 & 4 sind sowohl in der Zellmembran als auch intrazellulär in den Pansenepithelzellen lokalisiert. Die mRNA Expressionsdaten konnten zeigen, dass MCT1 und die PPARα Zielgene durch WY 14.643 hochreguliert werden konnten, wohingegen die MCT4 Expression keine eindeutige Antwort auf die Stimulation zeigt. Die Behandlung mit den Antagonisten zeigt eine Abhängigkeit der MCT1 Expression von PPARα, die MCT4 Expression konnte dagegen nicht beeinflusst werden. Mittels pHMB gelang es, den laktatabhängigen Protonenexport fast vollständig zu blocken. Sowohl laktatabhängiger Protonenexport als auch die Proteinexpression zeigten keine Änderung durch WY 14.643 Stimulation. Die Butyratexposition veränderte die Morphologie der Pansenepithelzellen und schien nicht geeignet für Untersuchungen der mRNA Expression zu sein. Schlussfolgerungen: Es konnte in dieser Arbeit erstmals gezeigt werden, dass MCT1 in Pansenepithelzellen über PPARα reguliert wird, nicht aber MCT4. PPARα scheint demnach einer der entscheidenden Angriffspunkte für die Regulation des SCFA Transportes zu sein, dessen natürliche Liganden im Pansen aber noch nicht bekannt sind. Damit legt diese Arbeit den Grundstein für regulative Studien am intakten PansenepithelIntroduction: Monocarboxylate transporters (MCT) 1 & 4 are cotransporters of monocarboxylates and protons in a variety of mammalian cell types. In the ruminal epithelium MCT are necessary to transport short-chain fatty acids (SCFA) from the lumen into the ruminal epithelial cell (MCT4) and to discharge SCFA and their metabolites from the cell into the blood (MCT1). Transepithelial permeation of SCFA is of great importance, because they are the main source of energy for ruminants. The regulation of appropriate transport proteins should thus be subject to the adaptation to varying SCFA amounts. Previous studies in other species suggested that gene expression of MCT1 is regulated by peroxisome proliferator-activated receptor α (PPARα), a ligand-activated nuclear receptor. Aims: The aim of the study was to examine if MCT1 in ruminal epithelial cells is regulated by PPARα and furthermore if MCT4 can be regulated by PPARα, as well. A simultaneous regulation seems likely, because both are acting jointly in the transepithelial transporting of SCFA. The implications of such a regulation on protein expression and transport capacity of MCT should be characterized. The effect of butyrate, a SCFA which increases under concentrate feeding, on MCT1 expression was determined. Materials & Methods: Ruminal epithelial cells of sheep were cultivated according to methods previously established. After subcultivation, immunocytochemistry with antibodies against MCT1, MCT4 and Na+/K+-ATPase was performed to determine their localization in ruminal epithelial cells. For studying the influence of PPARα, WY 14.643, a synthetic and selective ligand of PPARα, and GW 6471, a synthetic antagonist of PPARα, were applied to the culture medium of the cells. After processing the specimens, the relative amount of mRNA of MCT1, MCT4 and the target genes ACO, CPT1A and CACT were analyzed by qPCR and normalized on the reference genes GAPDH and Na+/K+-ATPase. Protein abundance of MCT1 & 4 was measured by using the Western Blot method. Functional quantification was measured by the intracellular pH (pHi) of cells using spectrofluorometry as well as comparing the effect of WY 14.643 treatment on lactate-dependent proton export. To determine the MCT-dependent part of the pHi recovery, p-hydroxymercuribenzoic acid (pHMB), a specific inhibitor of MCT1 & 4, was applied. Cells were also treated with butyrate for 6 h and 48 h and the mRNA abundance of MCT1 was analyzed by semiquantitative PCR. Results: Both MCT1 and MCT4 were localized in the cell membrane as well as in the cytoplasm of ruminal epithelial cells. By qPCR it could be demonstrated that the mRNA abundance of MCT1 and PPARα target genes in the ruminal epithelial cells was increased by WY 14.643 in comparison to untreated cells, whereas the response of MCT4 did not yield distinct results. Treatment with the PPARα antagonist pointed out, that MCT1 is influenced by PPARα, but not MCT4. Lactate-dependent proton export was blocked almost completely by pHMB. Both lactate-dependent proton export and protein expression were not altered by WY 14.643 treatment. Butyrate exposure changed the morphology of ruminal epithelial cells and seemed unsuitable for the analysis of mRNA expression. Conclusion: For the first time, it could be demonstrated, that MCT1 in ruminal epithelial cells is regulated by PPARα, but not MCT4. PPARα seems to be a vital target in the rumen for SCFA transport regulation, whose natural triggers have yet to be identified. Furthermore, this study provides the basis for regulative studies on intact ruminal epithelium
8
Hutchinson, Laura. "The role and therapeutic significance of monocarboxylate transporters in prostate cancer." Thesis, University of Manchester, 2017. https://www.research.manchester.ac.uk/portal/en/theses/the-role-and-therapeutic-significance-of-monocarboxylate-transporters-in-prostate-cancer(280f6221-d12b-4ca9-9322-e0ba1f5511f6).html.
Анотація:
It has been shown that tumour cells are capable of switching to glycolytic metabolism for the production of ATP even in the presence of oxygen, this is known as aerobic glycolysis or the 'Warburg effect'. The glycolytic phenotype has been associated with tumour aggressiveness and poor outcome in several cancer types. This makes the area of cancer metabolism an attractive area for the potential identification of new therapeutic targets. One key component, required for cells to maintain the glycolytic phenotype, is the presence of monocarboxylate transporters that are capable of exporting lactate. These transporters are vital for the maintenance of the intracellular pH of cells under these conditions. This study was centred around the hypothesis that altering expression of MCTs would impact on the metabolism of tumour cells and, therefore, other key characteristics of cells relating to metastatic capabilities and survival following treatment. For the purpose of this work, prostate cancer cell lines were transfected with lentiviral particles targeting overexpression of MCT1 or MCT4, or knockdown of MCT4. Following transfection, cellular metabolic profiles were assessed under normoxic and hypoxic conditions and the metastatic phenotype of each cell line was investigated. Additionally, the effect of MCT expression on response to chemotherapy and radiation therapy was explored, and a siRNA metabolome screen was performed to identify combinations of targets that may produce synthetic lethality in prostate cancer cell lines. It was shown that changes in the expression of MCT1 or MCT4 did not cause significant changes in the metastatic phenotypes of the prostate cancer cell lines investigated. Some differences were observed in the metabolic pathways used by these prostate cancer cells following alterations in MCT expression. For example, overexpression of MCT1 in DU145 cells resulted in an increase in intracellular lactate. Additionally, MCT4 knockdown in PC3 cells was able to reduce OXPHOS under reduced oxygen. MCT1 overexpression was able to sensitise androgen-independent prostate cancer cells to treatment with chemotherapy and radiation therapy. Furthermore, combinations of siRNA treatments were identified that may be capable of producing synthetic lethality. In summary, findings in this study indicated that targeting MCT1 and MCT4 expression could offer therapeutic benefit in prostate cancer. However, it was also highlighted that the roles of these transporters are specific to cancer type, and even cell line.
9
Manoharan, Christine. "The molecular basis for the interaction between MCT1 and MCT2 with the ancillary proteins CD147 and GP70." Thesis, University of Bristol, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.417644.
10
Py, Guillaume. "Étude du transport sarcolemmal du lactate et de l'expression des isoformes MCT1 et MCT4 chez le rat diabétique et Zucker fa/fa." Montpellier 1, 2001. http://www.theses.fr/2001MON1T014.
Анотація:
Le lactate a longtemps ete considere comme un produit final de la glycolyse et le temoin d'une limitation de l'apport en oxygene au niveau des tissus. Durant les vingt dernieres annees, grace au developpement de nouvelles techniques, des travaux ont permis de montrer que le lactate etait produit en condition d'oxygenaton normale et que celui-ci etait le substrat neoglucogenique de choix au niveau hepatique. Associe aux anomalies du metabolisme du glucose, l'etat de diabete et d'insulinoresistance sont caracterises par des lactatemies basales anormalement elevees. L'origine de ces niveaux eleves de lactate est encore mal definie. Nous avons, dans ce travail, mis en evidence des alterations des echanges sarcolemmaux du lactate dans des modeles animaux de diabete et d'obesite, a l'aide d'un modele subcellulaire que sont les vesicules de sarcolemme. [. . . ] ainsi, meme si les alterations de l'activite de transport du lactate dans le diabete de type 1 ne trouvent pas leur explication dans l'expression des isoformes musculaires de mct, il semble aux vues de donnees recentes, que ceux-ci soient quand meme impliques dans la diminution de la clearance du lactate. A la difference, la perturbation musculaire des echanges et du metabolisme du lactate dans l'obesite pourrait participer a l'etat d'insulinoresistance.
11
Brunton, Adam North. "MCP optics." Thesis, University of Leicester, 1994. http://hdl.handle.net/2381/35847.
Анотація:
This thesis is an account of research into a novel type of X-ray optic - the microchannel plate (MCP). Experiments to determine the point to point focusing properties of square pore MCPs manufactured by Galileo Electro-Optics and Philips Photonics are reported. These were performed both in a test chamber at Leicester with an electron-bombardment X-ray source and with a laser-plasma X-ray source at the Rutherford Appleton Laboratory. A resolution of 6 arcmin and an intensity gain of 20 were recorded using a Galileo focusing MCP. An invesigation into the focusing action of MCPs which have been curved to a spherical figure is detailed. Such curved MCPs may, in a manner reminiscent of a conventional refractive lens, be used to focus a parallel X-ray beam to a point forming the basis of an X-ray telescope, or conversely to convert the diverging beam from a point-like X-ray source to a quasi-parallel one. The curving experiments were performed by Philips Photonics on standard circular pore MCPs. Tests on these plates were performed at Leicester; the results appear favourable. The technique has been applied to MCPs of up to 4mm thickness, curving them to a radius of 1.4m (0.7m focal length). A comprehensive Monte Carlo ray-tracing model is presented. This was initially developed to facilitate an understanding of the geometry of MCP focusing and to produce idealised images corresponding to a given experimental set up. These perfect images may be compared with, or used to predict experimental results. Comparison with experimental results led to incorporation of MCP distortions into the code. These distortions have been found by a programme of metrology which is also described. The model has led to a clear insight into the causes of poor image quality and their relative importance.
12
Gierga, David P. (David Peter) 1974. "Electron photon calculations using MCNP." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/47683.
13
BERGMARK, FABIAN, and JOHAN STENBERG. "Heuristics in MCTS-based Computer Go : Can heuristics improve the performance of MCTS-based computer go?" Thesis, KTH, Skolan för datavetenskap och kommunikation (CSC), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-157529.
Анотація:
The subject of computer Go is an active eld under AI and has achieved much attention in research. The current state of the art computer Go im-plementations uses a game tree search approach rather than advanced heuristics. This thesis aims to bridge these two approaches and combineMonte Carlo Tree Search with heuristics to deduce if any general results can be found. The results of the thesis indicate that the performance of a combined MCTS-heuristic approach correlates strongly with performance of the heuristic. Furthermore, MCTS can be used with any heuristic to improve its performance.1
14
Konček, Róbert. "Simulace stínění ionizujícího záření programem MCNP." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2015. http://www.nusl.cz/ntk/nusl-221214.
Анотація:
Radiation is defined as ionizing if it has enough energy to remove electrons from atoms or molecules when it passes through or collides with matter. This ability implies potentially detrimental effects on living tissue. Ionizing radiation shielding is therefore a discipline of great practical importance. The thesis builds upon the author's previous work on the topic and widens the scope of discussion with theoretical and practical issues of advanced shielding calculations. The theoretical part of the thesis describes several approaches to calculating fluence or absorbed dose at an arbitrary point in space. Point-kernel methods provide sufficiently accurate results for simpler shielding problems. In many practical cases, however, calculations based on the transport theory are necessary. There are two basic types of transport calculations: deterministic transport calculations in which the linear Boltzmann equation is solved numerically, and Monte Carlo calculations in which a simulation is made of how particles migrate stochastically through the problem geometry. Advantages and disadvantages of both methods are discussed. In the practical part are the results of radiation shielding calculations performed with a major Monte Carlo code - MCNP6, compared with those obtained in the experiments, which were carried out at the Ionizing Radiation Laboratory at Department of Electrical Power Engeneering, FEEC BUT. The experiments consisted of placing a cobalt-60 radioisotope source at three different positions inside a lead collimator, and counting pulses with two different scintillation detectors positioned in front of the opening of the collimator, alternately with or without lead shield located between the source and the used detector. Agreement of the calculations and the data from the measurements is reasonable, given the inherent uncertainties of the experimental set-up. Performed sensitivity analysis shows relative importances of different parameters used as inputs in simulations, such as densities of materials, or dimensions of the scintillation crystals. Annotated MCNP input files used for simulation are also part of the thesis.
15
Lombardi, Lara. "Efeitos da meta-clorofenilpiperazina (mCPP) sobre mecanismo da mobilização leucocitária: estudos in vivo e in vitro." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/9/9141/tde-07032013-100506/.
Анотація:
A meta-clorofenilpiperazina (1-(3-clorofenil)piperazina; mCPP) é uma piperazina sintética que vem sendo apreendida de forma crescente no mercado de drogas ilícitas, primeiro na Europa e, a partir de 2006, também no Brasil. Recentemente há relatos de aumento significativo da apreensão de comprimidos vendidos como ecstasy e que na realidade contêm mCPP, porém estudos sobre potenciais riscos dessa utilização à saúde ainda são escassos. O papel da mCPP como agonista de receptores serotoninérgicos já está bem descrito na literatura, razão pela qual esta substância é amplamente empregada em trabalhos científicos, principalmente psiquiátricos. No entanto, poucos são os trabalhos realizados com o intuito de investigar mais profundamente as ações desencadeadas no organismo pela substância em si. É sabido que a serotonina é um neurotransmissor liberado por plaquetas no local de inflamação e que exerce papel imunomodulatório importante sobre as células imune Assim, considerando (1) a relevância atual da mCPP no contexto de apreensão de drogas de abuso, (2) a necessidade de estudos sobre efeitos das drogas de abuso no organismo, (3) escassez de avaliações dos efeitos da mCPP sobre o sistema imunológico e (4) sua provável correlação com este sistema a partir de suas ações em receptores serotoninérgicos, o presente trabalho pretendeu iniciar investigações acerca da atividade da mCPP sobre as respostas imune inatas e sobre os mecanismos da mobilização leucocitária. Para tanto, ratos Wistar machos foram tratados com mCPP (1mg/kg, v.o.) e foram realizadas quantificações de leucócitos na medula óssea, no compartimento circulante e no foco inflamatório (peritônio), em presença ou ausência de estímulo inflamatório (LPS, 1 mg/mL, i.p.), como também da mieloperoxidase presente em tecido hepático, pulmonar e do baço. Complementando os estudos in vivo, ainda foi quantificada a cortisona plasmática em animais que receberam tal tratamento tendo seus receptores de glicocorticoides previamente antagonizados (RU38486). Neutrófilos coletados do exsudato peritoneal foram incubados nas concentrações de 10 µM, 100 µM e 1000 µM in vitro e investigados a migração neutrofílica, a expressão das moléculas de adesão na superfície neutrofílica, a quantificação de mediadores inflamatórios no sobrenadante de cultura de neutrófilos e o processo de adesão neutrófilo-endotélio, com células endoteliais coletados a partir do cremáster. Os resultados demonstram que a mCPP diminuiu a quantificação de leucócitos no exsudato peritoneal e, concomitantemente, aumentou o influxo de PMN para o tecido pulmonar, em vigência de estímulo inflamatório. Ainda, in vivo, não foi possível observar diferenças na concentração de cortisona sérica entre animais cujos receptores de glicocorticóides foram antagonizados e aqueles cujos receptores em questão encontravam-se normais. In vitro, a mCPP, nas três concentrações empregadas, e tanto na vigência quanto na ausência de estímulo (LPS ou fMLP), causou alterações na migração dos neutrófilos, na adesão deste tipo celular ao endotélio, na expressão de moléculas de adesão (Lselectina, β2-integrina e PECAM-1) na superfície neutrofílica e na quantificação das concentrações de mediadores inflamatórios (NO, IL-1β, IL-10, TNF-α) no sobrenadante de cultura de neutrófilos. Os resultados obtidos sugerem, em conjunto, que a mCPP exerce atividade pró-inflamatória no que se refere à atividade neutrofílica, bem como sugerem que o fármaco seja capaz de amplificar a resposta inflamatória em modelo animal de rato, tanto in vivo quanto in vitro.The meta-chlorophenylpiperazine is a synthetic piperazine which has been seized increasingly in the illicit drug market, primarily in Europe and after 2006, in Brazil. Recently, there has been a significant increase on the apprehension of tablets sold as ecstasy but that in reality contain mCPP. Despite its importance, studies over its potential health risks are few. The mCPP role as serotonergic receptor agonist is well known in the literature, reason why this substance is widely employed in scientific research, particularly in psychiatric studies. But there are few reports that aim to investigate thoroughly the actions that this substance triggers in the organisms. It is also known that serotonin is a neurotransmitter released by platelets at the site of inflammation and plays important immunomodulatory role on immune cells. Therefore, considering (1) the relevance of mCPP in the drug abuse context nowadays, (2) the necessity of researching the effects of the drug abuse in the organisms, (3) the lack of studies containing analysis of the mCPP effects over the immune system and (4) the probable correlation between mCPP and this system, through its activity in serotoninergic receptors, this report intended to lead investigations about the mCPP activity over the innate immune response and over the leukocyte mobilization mechanisms. For this purpose, Wistar male rats were treated with mCPP (1mg/kg, v.o.), their leukocytes were measured in the bone marrow, in the circulating compartment and in the inflammatory foci (peritoneum) in the presence or absence of inflammatory stimuli (LPS, 1 mg/mL, i.p.) and the myeloperoxidase present in liver tissue, lung and spleen was also quantified. In addition to in vivo studies, the cortisone plasma was quantified in animals receiving such treatment with glucocorticoid receptors antagonized previously (RU38486). Neutrophils collected from the peritoneal exudate were incubated at concentrations of 10 mM, 100 mM and 1000 mM in vitro. It was then investigated the neutrophil migration and the expression of adhesion molecules on the surface of neutrophils as well as the quantification of inflammatory mediators in the culture supernatant. The process of neutrophil-neutrophil adhesion to endothelium was also analyzed and endothelial cells were collected from the cremaster. Results reflect that mCPP decreased the amount of leukocytes at the peritoneal exudate and, concomitantly, increased the influx of PMN into the lung tissue during an inflammatory stimulus. Also, in vivo, it was possible to observe differences in the concentration of serum from animals which cortisone glucocorticoid receptors were previously antagonized and those in which the receptors in question were normal. In vitro, mCPP in three concentrations employed, and both in the presence or absence of stimulus (LPS or fMLP) caused changes in the migration of neutrophils, in the cell adhesion to the endothelium, in the expression of adhesion molecules (L-selectin, integrin-β2 and PECAM-1), on the surface of neutrophils and in the concentrations of inflammatory mediators (NO, IL-1β, IL-10, TNF-α) in the culture supernatant of neutrophils. The results suggest that, together, mCPP exerts pro-inflammatory activity with respect to neutrophil activity. They also suggest that the drug is able to amplify the inflammatory response in an animal model rat both in vivo and in vitro.
16
Souza, Gregório Soares de. "Projeto e implantação de melhorias na blindagem biológica da instalação para estudos em BNCT." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/85/85133/tde-16062011-144054/.
Анотація:
A técnica de captura de nêutrons em Boro é uma técnica promissora de tratamento de câncer, ela usa do alto LET das partículas provenientes da reação 10B(n,α)7Li para destruir as células cancerígenas. O desenvolvimento desta técnica começou em meados da década de 50 e até hoje ela é alvo de estudos e pesquisas em diversos centros espalhados pelo mundo, no Brasil construiu-se uma instalação que tem como objetivo realizar pesquisas em BNCT, esta instalação está localizada junto ao canal de irradiação número três do reator nuclear de pesquisa IEA-R1 e possui uma blindagem biológica projetada para atender as normas de radioproteção. Esta blindagem biológica foi desenvolvida para permitir que se realizem experimentos com o reator ligado a potência máxima, fazendo com que não seja necessário ligar e desligar o reator para se irradiar amostras. Entretanto quando se abre o canal de irradiação o background do salão de experimentos do salão de experimentos aumenta e esta variação de background inviabiliza a realização das medidas do grupo de pesquisa em difração de nêutrons que utiliza o canal de irradiação número seis. Este trabalho tem como objetivo acrescentar melhorias na blindagem a fim de reduzir ao máximo essa variação de background fazendo com que seja possível realizar medidas na instalação de pesquisas em BNCT sem interferir nas medidas do grupo de pesquisa do canal de irradiação seis. Para isto, utilizou o código MCNP5, dosímetros termoluminescentes e detectores de ativação tipo folha para planejar melhorias na blindagem biológica. Calculou-se com o auxílio do código uma melhoria que consegue reduzir em média o fluxo térmico em 71,2 ± 13 % e verificou-se experimentalmente uma redução média de 70 ± 9 % na dose devido aos nêutrons térmicos.The technique of neutron capture in boron is a promising technique in cancer treatment, it uses the high LET particles from the reaction 10B (n, α) 7Li to destroy cancer cells.The development of this technique began in the mid-\'50s and even today it is the object of study and research in various centers around the world, Brazil has built a facility that aims to conduct research in BNCT, this facility is located next to irradiation channel number three at the research nuclear reactor IEA-R1 and has a biological shielding designed to meet the radiation protection standards. This biological shielding was developed to allow them to conduct experiments with the reactor at maximum power, so it is not necessary to turn on and off the reactor to irradiate samples. However, when the channel is opened for experiments the background radiation in the experiments salon increases and this background variation makes it impossible to perform measurements in a neutron diffraction research that utilizes the irradiation channel number six. This study aims to further improve the shielding in order to minimize the variation of background making it possible to perform the research facility in BNCT without interfering with the action of the research group of the irradiation channel number six. To reach this purpose, the code MCNP5, dosimeters and activation detectors were used to plan improvements in the biological shielding. It was calculated with the help of the code an improvement that can reduce the average heat flow in 71.2% ± 13 and verified experimentally a mean reduce of 70 ± 9% in dose due to thermal neutrons.
17
Lazarine, Alexis D. "Medical physics calculations with MCNP: a primer." Texas A&M University, 2006. http://hdl.handle.net/1969.1/4297.
Анотація:
The rising desire for individualized medical physics models has sparked a
transition from the use of tangible phantoms toward the employment of computational
software for medical physics applications. One such computational software for
radiation transport modeling is the Monte Carlo N-Particle (MCNP) radiation transport
code. However, no comprehensive document has been written to introduce the use of
the MCNP code for simulating medical physics applications. This document, a primer,
addresses this need by leading the medical physics user through the basic use of MCNP
and its particular application to the medical physics field.
This primer is designed to teach by example, with the aim that each example will
illustrate a practical use of particular features in MCNP that are useful in medical
physics applications. These examples along with the instructions for reproducing them
are the results of this thesis research. These results include simulations of: dose from
Tc-99m diagnostic therapy, calculation of Medical Internal Radiation Dose (MIRD)
specific absorbed fraction (SAF) values using the ORNL MIRD phantom, x-ray
phototherapy effectiveness, prostate brachytherapy lifetime dose calculations, and a
radiograph of the head using the Zubal head phantom. Also included are a set of appendices that include useful reference data, code syntax, and a database of input decks
including the examples in the primer. The sections in conjunction with the appendices
should provide a foundation of knowledge regarding the MCNP commands and their
uses as well as enable users to utilize the MCNP manual effectively for situations not
specifically addressed by the primer.
18
Meyer, Franziska. "Zelltyp-spezifische Inaktivierung von Mct8 in Gehirnzellen." Doctoral thesis, Humboldt-Universität zu Berlin, Lebenswissenschaftliche Fakultät, 2017. http://dx.doi.org/10.18452/17690.
Анотація:
Der Monocarboxylattransporter 8 (Mct8) ist ein spezifischer Schilddrüsenhormon (SDH)-Transporter. MCT8-Mutationen führen zu einer psychomotorischen Retardierung in Kombination mit abnormalen SDH-Serumkonzentrationen. Das konstitutiv Mct8-defiziente Mausmodell repliziert den endokrinologischen, jedoch nicht den humanen neurologischen Phänotyp. Um die Hypothese eines stark beeinträchtigten T3-Transportes speziell in Neuronen als Ursache zu untersuchen, wurde das Neuron-spezifische Mct8-defiziente Mausmodell (CamK-Cre;Mct8fl/fl) generiert. Neben einer funktionalen, Mct8-exprimierenden Blut-Hirn-Schranke liegt eine funktionale Hypophysen-Hypothalamus-Schilddrüsen Achse vor. NMR-Analysen des zerebralen Energiestoffwechsels von CamK-Cre;Mct8fl/fl-Mäusen zeigen nach [1-13C] Glukoseinfusion verringerte Laktatintensitäten sowie eine reduzierte Laktatdehydrogenase-Aktivität. Zudem sind Astrozyten-spezifische Transporter und Enzyme des Neurotransmitterstoffwechsels und deren Biosynthese in ihrer Genexpression reduziert. Somit führt der neuronale Mct8-Verlust zu einem verlangsamten zerebralen Metabolismus sowie einer reduzierten neuronalen Aktivität. Die Rolle von Mct8 im Energiestoffwechsel wurde außerdem in primären Mct8-defizienten Astrozyten- und Neuronkulturen mittels Seahorse Flux Analyzer untersucht. In Mct8-defizienten Neuronen kommt es zu einer verringerten SDH-Aufnahme, was in einer verringerten Expression von OXPHOS-relevanten Proteinen sowie in einer verringerten Sauerstoffverbrauchsrate resultiert. Somit stützen die in vitro Daten die des CamK-Cre;Mct8fl/fl-Mausmodelles bezüglich einer reduzierten neuronalen Aktivität sowie eines verlangsamten zerebralen Stoffwechsels. Zusammenfassend zeigen die Ergebnisse, dass grundlegende Mechanismen des zerebralen Stoffwechsels bei neuronaler Mct8-Defizienz beeinträchtigt sind und die Rolle von Mct8 mit Hilfe weiterer konditioneller Mausmodelle (Astrozyten-spezifisch) und primären Ko-Kulturmodellen untersucht werden muss.The monocarboxylate transporter 8 (Mct8) is the most specific thyroid hormone (TH) transporter. Mutations lead to a severe form of psychomotor retardation in combination with abnormal TH concentrations in sera. The global Mct8-deficient mouse model was intensively studied and it replicates the endocrine, but not the human neurological phenotype. To test the hypothesis, that a disturbed uptake of T3 especially into neurons is responsible for the phenotype, we generated a neuron-specific Mct8-deficient mouse model (CamK-Cre;Mct8fl/fl). CamK-Cre;Mct8fl/fl mice exhibit a functional Mct8-expressing blood-brain-barrier and a functional hypothalamus pituitary thyroid axis. NMR analyses of the cerebral energy metabolism of CamK-Cre;Mct8fl/fl mice after [1-13C] glucose injection revealed less enrichment of lactate and a reduced lactate dehydrogenase activity. Moreover, especially astrocyte-specific expressed transporter and enzymes of neurotransmitter metabolism and their biosynthesis are significantly reduced in comparison to control mice. These results point to a decelerated cerebral metabolism as well as a reduced neuronal activity caused by the neuronal loss of Mct8. In addition, we studied the impact of Mct8 on the energy metabolism in primary wildtype and Mct8-deficient astrocyte and neuron cultures by use of the Seahorse Flux Analyzer. Mct8-deficient neurons show a reduced uptake of TH, which results in a reduced expression of OXPHOS relevant proteins as well as a reduced oxygen consumption rate. Therefore, the in vitro raised data provide the observed changes of the CamK-Cre;Mct8fl/fl mice regarding a reduced synaptic activity as well as a reduced cerebral metabolism. Taken together, the data clearly shows that basic mechanisms of the cerebral metabolism are hampered in neuronal Mct8 deficiency. The role of Mct8 in this context needs further analyses with the help of conditional mouse models (astrocyte-specific) and primary co-culture models.
19
Awais, Muhammad [Verfasser]. "MCTS-based approximate accelerator synthesis / Muhammad Awais." Paderborn : Universitätsbibliothek, 2021. http://d-nb.info/1236630084/34.
20
Braun, Doreen [Verfasser]. "Der L-Typ Aminosäuretransporter 2 als möglicher kompensierender T3- Transporter bei Mct8-Defizienz: Untersuchung Slc7a8-defizienter Mäuse : Struktur-Funktionsanalysen in MCT8 anhand des MCT8-Homologiemodells / Doreen Braun." Berlin : Freie Universität Berlin, 2013. http://d-nb.info/1035406128/34.
21
Kumpf, Hermann. "Recriticality Calculations for Uraniumdioxide-Water Systems with MCNP." Forschungszentrum Dresden, 2010. http://nbn-resolving.de/urn:nbn:de:bsz:d120-qucosa-31135.
Анотація:
With the aim of generating a certain feeling for the general dependencies of the multiplication factor k∞ the first section provides some results for two classes of deformations of the original fuel pins. The main part examines UO2-structures of increasing disorder, beginning with the hexagonal close package of fuel spheres and ending up with stochastic geometries. Among these structures the worst case, i.e. the one with the highest k∞ but preserving mechanical stability is identified. The composition and geometric parameter of this case is used to calculate the critical thickness of a slab and critical radius of a sphere.
22
Usgaonker, Susrut Rajanikant. "MCNP modeling of prostate brachytherapy and organ dosimetry." Thesis, Texas A&M University, 2004. http://hdl.handle.net/1969.1/305.
Анотація:
Using the computer code Monte Carlo N-Particle (MCNP), doses were calculated for organs of interest such as the large intestine, urinary bladder, testes, and kidneys while patients were undergoing prostate brachytherapy. This research is important because the doses delivered to the prostate are extremely high and the organs near the prostate are potentially at risk for receiving high doses of radiation, leading to increased probabilities of adverse health effects such as cancer. In this research, two MCNP version 4C codes were used to calculate the imparted energies to the organs of interest delivered by 125I and 103Pd. As expected, the organs nearest to the prostate received the highest energy depositions and the organs farthest from the prostate received the lowest energy depositions. Once the energy depositions were calculated, the doses to the organs were calculated using the known volumes and densities of the organs. Finally, the doses to the organs over an infinite time period were calculated.
23
Law, Tsz Hong. "The effects of a MCTD in canine epilepsy." Thesis, Royal Veterinary College (University of London), 2017. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.766311.
24
Kumpf, Hermann. "Recriticality Calculations for Uraniumdioxide-Water Systems with MCNP." Forschungszentrum Rossendorf, 1997. https://hzdr.qucosa.de/id/qucosa%3A21940.
Анотація:
With the aim of generating a certain feeling for the general dependencies of the multiplication factor k∞ the first section provides some results for two classes of deformations of the original fuel pins. The main part examines UO2-structures of increasing disorder, beginning with the hexagonal close package of fuel spheres and ending up with stochastic geometries. Among these structures the worst case, i.e. the one with the highest k∞ but preserving mechanical stability is identified. The composition and geometric parameter of this case is used to calculate the critical thickness of a slab and critical radius of a sphere.
25
Sanchez, Andrea. ""Projeto e confecção de simuladores oftálmicos para aplicações clínicas"." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/85/85131/tde-04062007-151052/.
Анотація:
Este trabalho apresenta uma metodologia de cálculo para a obtenção de doses em estruturas do olho humano, como: esclera, coróide, retina, nervo óptico, corpo vítreo, câmara anterior, lente, além do tumor devido ao tratamento com placas oftálmicas. Construiu-se um modelo de olho humano com suas principais estruturas e dimensões fieis, além de um modelo matemático para uma placa de Co-60 e uma placa de sementes de I-125, levando-se em conta tamanho e disposição geométrica das fontes reais, com o código de Monte Carlo MCNP-4C. Esse modelo é capaz de calcular as distribuições de dose axiais e radiais para qualquer ponto do olho e para cada uma de suas estruturas. Construiu-se, também, um simulador de acrílico para o olho. Esse simulador é formado por uma esfera de acrílico fatiada em lâminas de 1 mm de espessura para simular as mesmas condições de simulação realizada pelos código MCNP-4C, fornecendo as doses axiais e radiais em filmes radiográficos. O simulador foi utilizado para validar os cálculos realizados com o código MCNP-4C. Os dados obtidos desse modelo matemático servirão para montar um banco de dados de doses para todas as estruturas do olho, posições e tamanhos de tumores e quaisquer placas oftálmicas utilizadas para tratamento. Esse banco de dados será a parte principal para a construção de um software nacional para cálculos de dose, que poderá fazer parte de um sistema de planejamento confiável para ser utilizado em radioterapia/braquiterapia.This work presents a calculational methodology for dose determination in human eye structures, such as: sclera, choroid, retina, lens, vitreous body, optic nerve and disc, and cornea, as well as tumor due to treatment to the eye plaques. A human eye model was constructed taking into consideration its main structural and dimension characteristics. Beyond that a mathematical model for the Co-60 and I-125 plaques with all geometric details were built employing the MCNP-4C code. This model is able to calculate the axial and radial doses in any point of the eye and for each of its structures. An acrylic eye simulator was also built with the aim to obtain experimental results for the both model validations. This simulator is made of an acrylic sphere split into foils of 1 mm thickness which allow the introduction a radiographic film to measure the axial and radial doses. The experimental data were used to validate the MCNP-4C results. The data from the mathematical model will serve as the basis to build a data bank for all the eye structures allowing different position and sizes of tumor as well as the replacement of all ophthalmic plaques used in the treatment. This data bank will be the principal part for the construction of a national software for the dose calculation and can be of great help for a reliable treatment system planning in radiotherapy/brachytherapy.
26
Ritzhaupt, Armin. "The role of monocarboxylate transporter (MCT1) in colonic short chain fatty acid (SCFA) transport : MCT1 expression in the healthy and diseased colon." Thesis, University of Liverpool, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.265123.
27
Redd, Randall Alex. "Radiation dosimetry and medical physics calculations using MCNP 5." Texas A&M University, 2004. http://hdl.handle.net/1969.1/467.
Анотація:
Six radiation dosimetry and medical physics problems were analyzed using a beta version of MCNP 5 as part of an international intercomparison of radiation dosimetry computer codes, sponsored by the European Commission committee on the quality assurance of computational tools in radiation dosimetry. Results have been submitted to the committee, which will perform the inter-code comparison and publish the results independently. A comparison of the beta version of MCNP 5 with MCNP 4C2 is made, as well as a comparison of the new Doppler broadening feature. Comparisons are also made between the *F8 and F6 tallies, neutron tally results with and without the use of the S(a,b) cross sections, and analytically derived peak positions with pulse height distributions of a Ge detector obtained using the beta version of MCNP 5.
The following problems from the study were examined:
Problem 1 was modeled to determine the near-field angular anisotropy and dose distribution from a high dose rate 192Ir brachytherapy source in a surrounding spherical water phantom.
Problem 2 was modeled to find radial and axial dose in an artery wall from an intravascular brachytherapy 32P source.
Problem 4 was modeled to investigate the response of a four-element TLD-albedo personal dosimeter from neutrons and/or photons. Significant differences in neutron response with S(a,b) cross sections compared to results without these cross sections were found.
Problem 5 was modeled to obtain air kerma backscatter profiles for 150 and 200 kVp X-rays upon a water phantom. Air kerma backscatter profiles were determined along the apothem and diagonal of the front face of the phantom. A comparison of experimental results is also made.
Problem 6 was modeled to determine indirect spectral and energy fluences upon two neutron detectors within a calibration bunker. The largest indirect contribution was found to come from low energy neutrons with an average angle of 47o where 0o is a plane parallel to the floor.
Problem 7 was modeled to obtain pulse height distributions for a germanium detector. Comparison of analytically derived peaks with peak positions in the spectra are made. An examination of the Doppler broadening feature is also included.
28
Johll, Mark. "MCNP simulations for standoff bomb detection using neutron interrogation." Thesis, Manhattan, Kan. : Kansas State University, 2009. http://hdl.handle.net/2097/2166.
29
Midenby, Johan. "Situation Awareness, en jämförelse mellan SPL, MCPP och COPD." Thesis, Försvarshögskolan, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:fhs:diva-7520.
Анотація:
Att utveckla och bibehålla situation awareness (SA) är en av de mest kritiska utmaningar i en stab i dagens konflikter. Det får avgörande betydelse för utgången av en konflikt. Om SA hanteras eller förstås felaktigt kan det leda till ökat mänskligt lidande i konfliktområden och förluster av människoliv. Det ökande internationella samarbetet gör att planeringsofficeren förutsätts kunna hantera flera olika processer. Syftet med uppsatsen var att jämföra och belysa skillnader hur SA skapas inom olika planeringsprocesser, samt vad försvårar utväxlingen av SA mellan processerna. Detta återspeglas i form av likheter och skillnader mellan planeringsmodellerna SPL, MCPP och COPD. Resultatet visar att det fanns stor likhet mellan processerna men det fanns också avgörande skillnader. I SA nivå 1 fanns en diskrepans mellan begreppen Centre of Gravity, caveats och gender. I SA nivå 2 skiljer bearbetningsprocesserna mellan planeringsmodellerna. I SA nivå 3 fanns den största och mest avgörande skillnaden där det kan konstateras att planeringsprocesserna inte utgår från samma byggstenar när det gäller att bygga planen. Medvetenhet och insikt för de olika planeringsprocessernas särart minskar risken för missförstånd.
30
Harrison, David. "MCP-dependent chemotaxis in Rhodobacter sphaeroides." Thesis, University of Oxford, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.360292.
31
Helck, Andreas. "Der Einfluss des partiellen MCP-1/CCL2-Antagonisten [18AA19]-MCP-1 auf den Verlauf der experimentellen Autoimmunuveitis." Diss., lmu, 2007. http://nbn-resolving.de/urn:nbn:de:bvb:19-65561.
32
Cuff, Mark Anthony. "Role and regulation of the human colonic monocarboxylate transporter, MCT1." Thesis, University of Liverpool, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.250486.
33
Jansen, Jürgen. "Mutations in thyroid hrmone transporter MCT8:genotype, function and phenotype." [S.l.] : Rotterdam : [The Author] ; Erasmus University [Host], 2008. http://hdl.handle.net/1765/12433.
34
He, Tao. "MCNP-Based Analysis on Simulating Small Changes in System Responses." University of Cincinnati / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1282061590.
35
D'Aria, Stefania. "Role of the Monocarboxylate transporter 1 (MCT1) in T lymphocytes." Doctoral thesis, Universite Libre de Bruxelles, 2020. https://dipot.ulb.ac.be/dspace/bitstream/2013/303141/3/table.pdf.
Анотація:
Upon activation, T cells shift towards a metabolic program characterized by increased glucose metabolism in order to sustain proliferation and effector function. Surprisingly, while resting T lymphocytes degrade glucose aerobically to CO2, proliferating T cells metabolize glucose almostentirely to lactate in the presence of oxygen through aerobic glycolysis (the Warburg effect). This metabolic switch comprises the upregulation of glycolytic enzymes and glucose transporters to the cell membrane, leading to an increase of glycolytic flux and the concomitant production of lactate. Despite many decades of research, we still do not fully understand the mechanisms that make proliferating T cells choose glycolysis rather than oxidation of glucose to produce energy. Since activated T lymphocytes depend on a glycolytic metabolism, they must release lactate, which inthese cells is facilitated by the proton-linked monocarboxylate transporter MCT1. The transporter is part of a protein family of 14 members among which MCT1–4 facilitate the passive transmembrane transport of monocarboxylates such as lactate, pyruvate and ketone bodies. The observation that pharmacological MCT1 inhibition has shown anti-proliferative effect on T cells suggests that lactate transport is essential to T cell expansion triggered after antigen recognition. The aim of our research is to investigate the importance of MCT1-dependent regulation in T cellmetabolism. Following TCR stimulation, MCT1 was expressed early in T cells unlike MCT4 whose significant expression was detected at later time point. To investigate the role played by MCT1 in the early steps of T cell activation, we generated a transgenic mouse model where conditional deletion of the MCT1 gene was achieved specifically in T cells. Phenotype and T cell distribution in thymus and peripheral organs were normal in MCT1fl/fl CD4Cre mice. However, lack of MCT1 expression decreased the proliferative capacity of in vitro activated CD4+ or CD8+ T cells without altering their viability. We observed that the IL-2 production was also affected by the lack of MCT1 expression, in line with decreased proliferative ability. Moreover, in vivo, T cell expansion that followed antigenic stimulation as well as T cell-mediated immune response to infection were deficient in MCT1fl/flCD4Cre mice. Our data indicate that this situation resulted from a cellular energy shortage caused by reduced glycolytic activity soon after activation. Moreover, energy crisis was amplified by the necessity to use ATP-consuming mechanisms for excluding H+ protons from the cytosol of activated MCT1-deficient T cells. Thus, in T cells, early MCT1 expression after activation ensures an energy saving mechanism for regulating cytoplasm acidification. Our observations also indicate that a high glycolytic flux is required in dividing T cells to maintain pH homeostasis.Doctorat en Sciences biomédicales et pharmaceutiques (Médecine)
info:eu-repo/semantics/nonPublished
36
Badri, Linda. "Mcp : environnement de conception détaillée de logiciels." Lyon, INSA, 1990. http://www.theses.fr/1990ISAL0021.
Анотація:
L'importance du logiciel est un fait dont les responsables de projets informatique sont aujourd'hui pleinement conscients. Pour cette raison, les utilisateurs et les concepteurs de produits logiciels sont de plus en plus exigeants et ressentent de façon aiguë et urgente la nécessité de développer des méthodologies pour la réalisation et la validation des produits logiciels. L'approche que nous proposons entre dans cette perspective en mettant en œuvre des stratégies intervenant dans les deux phases du cycle de vie conception détaillée et codage pour aboutir à une méthodologie de conception de programmes (MCP). MCP propose à l'utilisateur une démarche guidée selon un processus établi pour rationaliser la production des logiciels et en augmenter la qualité en respectant certaines étapes de production. Pour la phase de conception, nous avons d6fini un langage algorithmique (LA) adapté aux concepts de la programmation modulaire et d' encapsulation. La démarche retenue s' appuie également sur l'analyse descendante par raffinements successifs pour les données comme pour les programmes. Par ailleurs une aide à la saisie est fournie lors de l'écriture d'un programme, déchargeant ainsi l'utilisateur d'un ensemble de tâches fastidieuses et redondantes. MCP permet également l'accès à une banque d'entités logicielles : types abstraits et outils. Le passage de la phase de conception détaillée à la phase de codage se fait de façon automatique: on assure ainsi une continuité entre les phases. Outre ces apports, MCP fournit automatiquement une documentation plus ou moins détaillée selon le souhait de l'utilisateur. En résumé, MCP donne à l'utilisateur les moyens d'une conception rigoureuse (par l'utilisation du LA) et contrôlée, elle assure la production automatique d'une documentation et permet enfin une bonne communication et une transition cohérente entre les phases de conception détaillée et de codage.
37
Scheiner, Justin Jack. "Effect of 1-methylcyclopropene on upland cotton." Texas A&M University, 2003. http://hdl.handle.net/1969.1/5761.
Анотація:
Ethylene plays a key role in square and boll abscission in cotton (Gossypium
hirsutum L.). When subjected to stress, cotton plants synthesize higher rates of ethylene
which can result in the loss of immature fruit. The ethylene action inhibitor 1-
methylcyclopropene (1-MCP) is used in many fruit, vegetable, and floriculture crops to
counter the effects of ethylene. Protecting a cotton crop from ethylene through its early
reproductive stages may boost yields by increasing fruit retention. A two-year field study
was conducted in 2005 and 2006 at the Texas Agricultural Experiment Station in
Burleson County, Texas to evaluate the effects of 1-MCP concentration and timing on
cotton growth and yield components.
The study was designed as a randomized complete block with 4 replications.
Three rates of 1-MCP (250, 500, and 1250 g ha-1 of actual product) were applied as a
foliar spray at a delivery rate of 93.50 L -1 ha. Each rate was applied at pinhead-square
and fourteen days after pinhead-square; pinhead-square, fourteen days after pinheadsquare,
and early bloom; early bloom and fourteen days after early bloom; early bloom,
fourteen days after early bloom, and twenty-eight days after early bloom. Plant heights,
total number of nodes per plant, percent square abscission, nodes above white flower (NAWF), relative chlorophyll content, fruit number, fruit size, and fruit distribution were
not affected by 1-MCP. In 2006, electrolytic leakage was significantly increased by two,
250 g ha-1, 1-MCP treatments. In 2005, yield was significantly increased by six of the 1-
MCP treatments and suggests an increase in boll retention, boll size, seed number, or
seed size. The analysis of yield components conducted through box-mapping, however,
failed to explain the observed yield response. In 2006, 1-MCP did not significantly
influence yield.
38
Sample, Scott Alexander. "Evaluation of Beam Angle Scoring Using MCNP and Applied to IMRT." Thesis, Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/14570.
Анотація:
Equispaced beam arrangements are typically used for IMRT plans. This beam arrangement provides adequate dose coverage to the target while sparing dose to other structures. However, an equispaced beam arrangement may not provide the best dose coverage to the target while sparing dose to the other structures.
Beam angle optimization attempts to optimize the beam directions to produce a better IMRT plan; this is achieved by increasing dose to the target while minimizing dose to the remaining structures. Most methods of beam angle optimization attempt to optimize the beam angles and the beam intensity profiles to find an optimal set of beam angles. This thesis attempts to optimize the beam angles without determining the beam intensity profiles. An MCNP simulation is run to score the beam directions; the simulation is run as an adjoint problem to reduce simulation time, with the target as the source and the detectors scoring the dose for the gantry angles of the beam. Then, an optimization algorithm is run to select a set of beam angles for an optimized IMRT plan. The optimized IMRT plan is compared to an equispaced IMRT plan on a commercial treatment planning system to determine if this method of beam angle optimization is better than using an equispaced beam arrangement.
The results of this thesis indicate that the coupling of an MCNP simulation for scoring with an optimization algorithm to select beam angles will produce a better IMRT plan than an equispaced IMRT plan. Three different geometries were used and for all geometries, the optimized IMRT plan had a higher average dose to the target while maintaining or increasing dose sparing to the critical structure and normal tissue.
39
Mireles-Garcia, Fernando. "Evaluation of 2-PI liquid scintillation whole body counter using MCNP /." free to MU campus, to others for purchase, 1997. http://wwwlib.umi.com/cr/mo/fullcit?p9841175.
40
Akimana, Christine. "Structural and Functional Analysis of Moraxella catarrhalis Adhesins MCAP and OMPCD." University of Toledo Health Science Campus / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=mco1180025995.
41
Possani, Rafael Guedes. "Re-engenharia do software SCMS para uma linguagem orientada a objetos (Java) para uso em construções de phantoms segmentados." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/85/85133/tde-04062012-152752/.
Анотація:
Metodologias recentes de planejamento dependem fortemente de imagens de tomografia computadorizada e a tendência é que os procedimentos de dosimetria interna na terapia usando medicina nuclear também sejam baseados em imagens, tais como, imagens de ressonância magnética (RM) e tomografia computadorizada (TC), que extraem informações anatômicas e histológicas, bem como, imagens funcionais ou mapas de atividades, provenientes de PET e SPECT. Estas informações, associadas a um software de transporte de radiação, são utilizadas para estimar a dose interna em pacientes submetidos a tratamento em medicina nuclear. Este trabalho visa a re-engenharia do SCMS, que é um software de interface entre o código MCNP e as imagens médicas, que carregam as informações do paciente em tratamento. Em outras palavras, as informações necessárias contidas nas imagens são interpretadas e apresentadas em um formato específico para o código MCNP, que executa a simulação do transporte de radiação. Portanto, o usuário não precisa compreender o complexo processo de introdução de parâmetros do MCNP, pois o SCMS é responsável por construir automaticamente dados anatômicos do paciente, bem como, os dados da fonte radioativa. O SCMS foi originalmente desenvolvido em Fortran-77 e neste trabalho, ele foi reescrito em uma linguagem orientada a objetos (JAVA). Novas funcionalidades e opções de dados também foram incorporadas ao software. Assim, o novo software tem uma série de melhorias, tais como interface gráfica intuitiva e um menu para a seleção do espectro de energia correspondente a um radioisótopo específico, armazenado em um banco de dados XML. A nova versão também trabalha com uma maior quantidade de materiais e o usuário pode especificar uma região de interesse na tomografia computadorizada para o cálculo da dose absorvida.Recent treatment planning systems depend strongly on CT images and the tendency is that the internal dosimetry procedures in nuclear medicine therapy be also based on images, such as magnetic resonance imaging (MRI) and computed tomography (CT), to extract anatomical and histological information, as well as, functional imaging or activities map as PET and SPECT. This information associated with a radiation transport simulation software is used to estimate internal dose in patients undergoing treatment in nuclear medicine. This work aims to re-engineer the software SCMS, which is an interface software between the Monte Carlo code MCNP, and the medical images, that carry information from the patient in treatment. In other words, the necessary information contained in the images are interpreted and presented in a specific format to the Monte Carlo MCNP code to perform the simulation of radiation transport. Therefore, the user does not need to understand the complex process of inputting data on MCNP, as the SCMS is responsible for automatically constructing anatomical data from the patient, as well as the radioactive source data. The SCMS was originally developed in Fortran-77. In this work it was rewritten in an object-oriented language (JAVA). New features and data options have also been incorporated into the software. Thus, the new software has a number of improvements, such as intuitive GUI and a menu for the selection of the energy spectra correspondent to a specific radioisotope stored in a XML data bank. The new version also supports new materials and the user can specify an image region of interest for the calculation of absorbed dose.
42
Kinkelin, Christophe. "Etude expérimentale d’un amortisseur thermique composite MCP-NTC." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSEI100/document.
Анотація:
L’amortisseur thermique étudié dans le cadre de cette thèse a pour objectif de limiter les pics de température des composants électroniques fonctionnant en régime transitoire au moyen d’une structure composite consistant en un réseau de nanotubes de carbone (NTC) rempli de matériau à changement de phase (MCP) solide-liquide, le tout étant contenu dans un boîtier en silicium (Si). Ce système passif vise à augmenter l’inertie thermique volumique du composant grâce à la chaleur latente du MCP tout en maintenant une bonne conductance thermique grâce aux NTC. Un dispositif expérimental polyvalent a été développé spécifiquement pour caractériser les différentes générations d’échantillons fabriqués par les partenaires du projet THERMA3D. L’excitation thermique de l’échantillon est réalisée au moyen d’un laser en face amont et la réponse thermique est mesurée par caméra infrarouge simultanément sur les faces amont et aval. L’application d’une peinture sélectionnée sur l’échantillon permet d’accéder à sa température après un étalonnage dédié. Des méthodes d’estimation de paramètres ont été développées pour quantifier les deux caractéristiques essentielles de l’amortisseur thermique que sont sa capacité de stockage thermique et sa résistance thermique. Les sensibilités de la résistance thermique aux caractéristiques de la connexion Si/NTC et à la longueur des NTC ont été étudiées et les résistances thermiques d’interface Si/NTC ont été identifiées comme dominantes au sein du système. Des essais de cyclage thermique ont permis d’évaluer la fiabilité de l’ensemble de manière accélérée. Le comportement du MCP et la qualité du matériau de scellement ont été analysés par voie optique. Par ailleurs, la plus élevée des deux résistances thermiques d’interface Si/NTC a été localisée grâce à la visualisation infrarouge du réseau de NTC à travers le silicium semi-transparent. Enfin, une méthode de contrôle non destructif de la qualité de l’interface Si/NTC a été développée pour les amortisseurs thermiques de dernière générationThe purpose of the studied thermal damper is to smooth the temperature peaks of transient electronic components via a composite structure consisting of an array of carbon nanotubes (CNT) filled with solid-liquid phase change material (PCM), the whole being embedded in a silicon (Si) casing. This passive system is intended to increase the thermal inertia per unit of volume of the electronic component thanks to the latent heat of the PCM while maintaining a high thermal conductance thanks to the CNT. A versatile test bench was specifically developed in order to characterize the different generations of samples fabricated by the partners of the THERMA3D project. The thermal excitation of the front side of the sample is generated by a laser and the thermal response is measured simultaneously on the front and back sides by an infrared camera. A selected paint can be deposited on the sample in order to access its temperature by means of a dedicated calibration. Parameter estimation methods were developed in order to quantify both main characteristics of the thermal damper: its heat storage capacity and its thermal resistance. The sensitivities of the thermal resistance to the features of the Si/CNT connection and to the length of the CNT were studied and it was found out that the interfacial thermal resistances Si/CNT are dominant in the system. Thermal cycling tests enabled to assess the reliability of the thermal damper in an accelerated manner. The behavior of the PCM and the quality of the sealing material were optically analyzed. Besides, the infrared visualization of the CNT array through the semi-transparent silicon enabled to identify the highest of both Si/CNT interfacial thermal resistances. Finally, a non-destructive testing method for the evaluation of the quality of Si/CNT interfaces was developed for the latest generation of thermal dampers
43
Turner, Sarah Jane. "Signalling cascades activated by the chemokine MCP-1." Thesis, University of Bath, 1996. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321847.
44
Hatting, Christiaan. "The economic impact of special events: a case study of the Mother City Queer project (MCQP) 2009." Thesis, Cape Peninsula University of Technology, 2011. http://hdl.handle.net/20.500.11838/1605.
Анотація:
Dissertation (MTech(Tourism and Hospitality Management))--Cape Peninsula University of Technology, 2011Cape Town, which is known as the Mother City of South Africa, is regarded as one of the most beautiful cities in the world: ‘heaven at the tip of Africa’, and was voted by the premier gay travel guide, Spartacus International Gay Guide, as one of the top five gay travel destinations in the world. The well-publicised myth of gays as DINKs who need somewhere to spend their above average disposable income has led to the vigorous courting of the gay niche by a variety of organisations that seek new markets. However, South Africa, an emerging destination, is merely beginning to understand niche markets. The research was motivated by limited market intelligence about the economic impact and changes in inbound niche markets, especially with regard to the gay market in Cape Town. In order for Cape Town to remain successful in attracting the international gay market, Cape Town’s tourism planners, marketers and local community should be continuously reminded about the economic worth of gay tourists, as a weak rand relative to other major world currencies, and high standard of gay facilities make the City attractive for gay visitors who bring foreign currencies. Understanding the economic impact of gay tourism by using the 2009 MCQP as a case in reference is, therefore, of paramount importance for Cape Town marketers to ensure that they target the gay market effectively at present and in future. The purpose of the study was to analyse the economic impact of the 2009 MCQP on the local economy by translating the total sales effect obtained by multiplying direct sales with appropriate multipliers, into an analytical framework, namely the ‘System of equations for estimating local economic impact.’
45
Poudel, Sashi. "Variation in tissue correction factors for LiF, Al2O3 and Silicon Dosimeters as a function of tissue depth with comparison between intensity weighted mono-energetic photon and the poly-energetic photons used in brachytherapy and diagnostic radiology." Digital WPI, 2017. https://digitalcommons.wpi.edu/etd-dissertations/487.
Анотація:
"The MCNP6 radiation transport code was used to quantify changes in the absorbed dose tissue conversion factors for LiF, Al2O3, and silicon-based electronic dosimeters. While normally calibrated in-air and applied to all general geometric measurements, tissue conversion factors for each dosimeter were obtained at various depths in a simulated water phantom and compared against the standard in-air calibration method. In these experiments, a mono-energetic photon source was modeled at energies between 30 keV and 300 keV for a point-source placed at the center of a water phantom, a point-source placed at the surface of the phantom, and for a 10-cm radial field geometry. Again, mono-energetic photon source was modeled up to 1300 keV for a disk-source placed at the surface of the phantom and dosimetric calculations were obtained for water, LiF, Al2O3, and silicon at depths of 1 mm to 35 cm from the source. The dosimeter’s absorbed dose conversion factor was calculated as a ratio of the absorbed dose to water to that of the dosimeter measured at a specified phantom depth. The dosimeter’s calibration value also was obtained for both mono and polyenergetic source and the calibration value from poly-energetic source was compared with the intensity weighted average calibration value from mono-energetic photon. The calculated changes in the tissue conversion factors are significant because the American Association of Physicists in Medicine (AAPM) recommend that measurements of a brachytherapy or diagnostic source be made with an overall uncertainity of 5% or better. Yet, based on results, the absorbed dose tissue conversion factor for a LiF dosimeter was found to deviate from its calibration value by up to 9%, an Al2O3 dosimeter by 43%, and a silicon dosimeter by 61%. These uncertainties are in addition to the normal measurement uncertainties. By applying these tissue correction factors, these data may be used to meet the AAPM measurement requirements for mono-energetic and poly-energetic sources at measurement depths up to 35 cm under the irradiation geometries investigated herein. "
46
Fong, Kenneth B. "Measuring the TG-43 Parameters of Iridium-192 using Monte Carlo-based Dosimetry." Digital WPI, 2019. https://digitalcommons.wpi.edu/etd-theses/1344.
Анотація:
Radioactive sources used in brachytherapy must be dosimetrically characterized prior to clinical use as defined the TG-43 protocol. In our previous project, Gafchromic film dosimetry was used to experimentally obtain the anisotropy function for an M-19 iridium-192 brachytherapy seed being developed by Source Production Equipment Corp (St. Rose, LA). In this project, the Monte Carlo N-Particle Transport code (MCNP) was used to computationally obtain the full set of TG-43 parameters including the Dose Rate Constant, the Reference Dose Rate, the Radial Dose Function, and the Anisotropy Constant for the M-19 seed.
47
Massicano, Felipe. "Modelagem de um sistema de planejamento em radioterapia e medicina nuclear com o uso do código MCNP6." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/85/85133/tde-11032016-093447/.
Анотація:
O tratamento de câncer possui diversas modalidades. Uma delas é a utilização de fontes de radiação como principal protagonista do tratamento. A radioterapia e a medicina nuclear são exemplos desse tipo de tratamento. Por utilizarem a radiação ionizante como principal ferramenta para a terapia, há a necessidade de se efetuar diversas simulações do tratamento a fim de maximizar a dose nos tecidos tumorais sem ultrapassar os limites de dose nos tecidos sadios circunvizinhos. Os sistemas utilizados na simulação desses tipos de terapia recebem o nome de Sistemas de Planejamento Dosimétrico. A medicina nuclear e a radioterapia possuem seus próprios sistemas de planejamento dosimétricos devido a grande diversidade das informações necessárias às suas simulações. Os sistemas de planejamento em radioterapia são mais consolidados do que os de medicina nuclear e por tal motivo um sistema que aborde tanto os casos de radioterapia como de medicina nuclear contribuiria para significativos avanços na área de medicina nuclear. Dessa forma, o objetivo do trabalho foi modelar um Sistema de Planejamento Dosimétrico com o uso do código de Monte Carlo MCNP6 Monte Carlo N-Particle Transport Code que permitisse incorporar os casos de radioterapia e medicina nuclear e que fosse extensível a novos tipos de tratamentos. A modelagem desse sistema resultou na construção de um Framework, orientado a objetos, nomeado IBMC o qual auxilia no desenvolvimento de sistemas de planejamento que necessitam interpretar grandes quantidades de informações com o objetivo de escrever o arquivo base do MCNP6. O IBMC permitiu desenvolver de maneira rápida e prática sistemas de planejamento para radioterapia e medicina nuclear e os resultados foram validados com sistemas já consolidados. Ele também mostrou alto potencial para desenvolver sistemas de planejamento de novos tipos de tratamentos que utilizam a radiação ionizante.Cancer therapy has many branches and one of them is the use of radiation sources as treatment leading method. Radiotherapy and nuclear medicine are examples of these treatment types. For using the ionization radiation as main tool for the therapy, there is the need of crafting many treatment simulation in order to maximum the tumoral tissue dose without throught the dose limit in health tissue surrounding. Treatment planning systems (TPS) are systems which have the purpose of simulating these therapy types. Nuclear medicine and radiotherapy have many distinct features linked to the therapy mode and consequently they have different TPS destined for each. The radiotherapy TPS is more developed than the nuclear medicine TPS and by that reason the development of a TPS that was similar to the radiotherapy TPS, but enough generic for include other therapy types, it will contribute with significant advances in nuclear medicine and in others therapy types with radiation. Based on this, the goal of work was to model a TPS that utilizes the Monte Carlo N-Particle Transport code (MCNP6) in order to simulate radiotherapy therapy, nuclear medicine therapy and with potential for simulating other therapy types too. The result of this work was the creation of a Framework in Java language, objectoriented, named IBMC which will assist in the development of new TPS with MCNP6 code. The IBMC allowed to develop rapidly and easily TPS for radiotherapy and nuclear medicine and the results were validated with systems already consolidated. The IBMC showed high potential for developing TPS by new therapy types.
48
Antunes, Paula Cristina Guimarães. "Reconstrução de objetos simuladores segmentados aplicáveis à dosimetria de pele." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/85/85133/tde-12082011-164705/.
Анотація:
A radioterapia é uma modalidade terapêutica que utiliza radiações ionizantes para erradicar as células neoplásicas do organismo humano. Um dos requisitos para o sucesso desta metodologia de tratamento está na utilização adequada dos sistemas de planejamento, os quais, dentre outras informações, estimam a dose a ser administrada aos pacientes. Atualmente, códigos de transporte de radiação têm proporcionado grandes subsídios a estes sistemas de planejamento, uma vez que viabilizam avaliações dosimétricas acuradas nos órgãos e tecidos específicos de um paciente. O modelo utilizado por estes códigos para descrever a anatomia humana de forma realista é denominado Objeto Simulador Segmentado (OSS), que consiste na representação das estruturas anatômicas do corpo em discretos elementos de volume (voxels), os quais são diretamente associados aos dados tomográficos. Atualmente, os OSS possíveis de serem inseridos e processados pelo código de transporte MCNP (Monte Carlo N-Particle), apresentam voxels com resoluções da ordem de 3-4 mm. No entanto, tal resolução compromete a discriminação de algumas estruturas finas do corpo, tais como a pele. Neste contexto, o presente estudo propõe a criação de uma rotina de cálculo que discrimine a região da pele, com espessura e localização próximas do real, nos OSS e os habilite para avaliações dosimétricas acuradas. A metodologia proposta consiste na manipulação dos elementos de volume dos OSS de forma a segmentá-los e subdividi-los em diferentes espessuras de pele. A fim de validar os dados obtidos por cálculos, foram realizadas avaliações experimentais de dosimetria de pele em objetos simuladores antropomórficos com dosímetros termoluminescentes. Verificou-se, ao longo deste estudo, a importância de discriminar a região da pele com localização e espessuras próximas do real, uma vez que foram encontradas diferenças significativas entre as estimativas de dose absorvida na região pelas diferentes representações. A metodologia proposta neste estudo far-se-á útil para avaliações dosimétricas acuradas da região de pele para diversos procedimentos radioterápicos, com particular interesse na radioterapia com feixe de elétrons, na qual se destaca a terapia de irradiação de corpo inteiro (TSET Total Skin Electron Therapy), procedimento radioterápico em implementação no Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (HC-FMUSP).Radiotherapy is a therapeutic modality that utilizes ionizing radiation for the destruction of neoplastic human cells. One of the requirements for this treatment methodology success lays on the appropriate use of planning systems, which performs, among other information, the patients dose distribution estimate. Nowadays, transport codes have been providing huge subsidies to these planning systems, once it enables specific and accurate patient organ and tissue dosimetry. The model utilized by these codes to describe the human anatomy in a realistic way is known as voxel phantoms, which are represented by discrete volume elements (voxels) directly associated to tomographic data. Nowadays, voxel phantoms doable of being inserted and processed by the transport code MCNP (Monte Carlo N-Particle) presents a 3-4 mm image resolution; however, such resolution limits some thin body structure discrimination, such as skin. In this context, this work proposes a calculus routine that discriminates this region with thickness and localization in the voxel phantoms similar to the real, leading to an accurate dosimetric skin dose assessment by the MCNP code. Moreover, this methodology consists in manipulating the voxel phantoms volume elements by segmenting and subdividing it in different skin thickness. In addition to validate the skin dose calculated data, a set of experimental evaluations with thermoluminescent dosimeters were performed in an anthropomorphic phantom. Due to significant differences observed on the dose distribution of several skin representations, it was found that is important to discriminate the skin thickness similar to the real. The presented methodology is useful to obtain an accurate skin dosimetric evaluation for several radiotherapy procedures, with particular interest on the electron beam radiotherapy, in which highlights the whole body irradiation therapy (TSET), a procedure under implementation at the Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (HC-FMUSP).
49
Blümel, Claudia. "Das Melanom-assoziierte Chondroitinsulfat-Proteoglykan (MCSP) als Zielmolekül für bispezifische Einzelketten-Antikörper /." München, 2007. http://opac.nebis.ch/cgi-bin/showAbstract.pl?sys=000254333.
50
Gerrity, Thomas P. III. "MCODE-3 : time-dependent depletion isotopics with MCNP-5 and SCALE-6.1." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/76964.
Анотація:
Thesis (S.M. and S.B.)--Massachusetts Institute of Technology, Dept. of Nuclear Science and Engineering, 2012.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 45).
In order to operate a reactor safely and efficiently, computer simulations must be used to predict certain nuclear characteristics of the reactor. To determine how materials change in a fission power environment, a time-dependent depletion isotopic code must be used. Over the past several decades, the MIT Reactor (MITR) has taken many steps to prepare for its conversion from the use of highly enriched uranium (HEU) to low enriched uranium (LEU) in its fuel. Throughout this process, detailed neutronics simulations must be run to predict the characteristics of the reactor with its current HEU fuel, with potential forms of LEU fuel, and with combinations of the two. MCODE Version 3 is a linkage code that performs time-dependent burnup calculations by combining the Monte Carlo N-Particle transport code, MCNP, with the Oak Ridge Isotope Generation point depletion code, ORIGEN-S. MCNP provides reaction rates and neutron flux in user-specified irradiation material regions. COUPLE, a data-editing code included in the SCALE- 6.1 software package, uses these data from MCNP to update the cross section libraries, which ORIGEN then uses to perform nuclide depletion calculations in each irradiation zone. The MCNP model is then updated with the depleted material compositions, and the exchange is repeated. The MCNP/ORIGEN coupling utilizes an optional predictor-corrector capability. As a newer version of MCODE Version 2.2, MCODE-3 offers three major changes from its predecessor. The first is the incorporation of ORIGEN-S. MCODE-2 used a previous version of ORIGEN, which is no longer supported by ORNL. ORIGEN-S provides newer nuclear data as well as additional functionality and usability. Secondly, MCODE-3 uses COUPLE to create an entirely unique cross section library from the regionally averaged 238-group flux, which means every cross section value that MCODE-3 uses in its depletion is specific to the input model. MCODE-2 only updates a fraction of nuclides' cross sections, the rest default to a pre-compiled library. Finally, while MCODE-2.2 was written in ANSI C, MCODE-3's main function has been rewritten in the Python scripting language. MCODE's preproc, mcodeout, and mcnpxs programs have not been edited, and are thus still written in ANSI C. Benchmarking has indicated that while the evolution of most nuclides is similar to an MCODE-2 calculation, over many depletion steps some nuclides can diverge due to COUPLE's use of the 238-group flux.
by Thomas P. Gerrity, III.
S.M.and S.B.