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Comportement axial des ancrages passifs scellés au rocher : étude de l’interface barre-scellement et modélisation / Axial behavior of fully grouted rockbolts : study of the bolt-grout interface and modelingHo, Duc An 16 January 2017 (has links)
L’installation et la maintenance des ancrages passifs scellés au rocher représentent un coût important dans le budget de fonctionnement des infrastructures de transport sujettes à l’aléa rocheux. Dans ce contexte, clarifier et optimiser les méthodes de dimensionnement actuellement employées représente un enjeu fort. Or le comportement d’un ancrage passif scellé au rocher est très complexe : il fait intervenir non seulement la rupture des matériaux constituants mais également la rupture des interfaces. Par ailleurs, la résistance de l’interface barre-scellement lors de l’arrachement d’un ancrage dépend du caractère dilatant de cette interface, liée à la géométrie de la barre (verrous) et à la plastification du matériau de scellement. Le travail de cette thèse porte sur une meilleure compréhension du comportement en traction d’un ancrage passif scellé au rocher, l’objectif étant d’améliorer la conception et le dimensionnement des ancrages sollicités axialement. Premièrement, le travail a consisté à définir le comportement de l’interface barre-scellement, Pour cela, un modèle numérique a été développé afin de reproduire des essais d’arrachement, sous différentes contraintes de confinement radial, de barres d’acier de haute adhérence (HA) scellées sur une longueur de 15 cm dans un cylindre de coulis de ciment (Moosavi et al. 2005). La géométrie réelle de l’interface acier–scellement a été considérée dans le modèle. Le comportement du coulis de scellement a été représenté par un modèle de type «concrete damage plasticity» (CDP), modèle de Lubliner (1986), implémenté dans Abaqus (2012). La représentation dans une approche continue de la plastification locale et de la fissuration, a nécessité un calage pour tenir compte des effets d’échelle. Le comportement de l’interface barre-scellement a ainsi été identifié comme cohésif dommageable avec frottement, dans une bande de cisaillement de largeur entre 2 et 3 fois la hauteur des verrous. Dans l’objectif de simuler un ancrage sur le terrain, des éléments d’interface représentant le contact acierscellement (sans les verrous) ont été développés.. La performance des éléments a été testée par la modélisation d’essais réalisés par Benmokrane et al. (1995) pour des barres de HA scellées en forage dans un bloc de béton, c’est-à-dire avec des conditions-limites radiales à rigidité constante. En parallèle, afin de tester l’influence de différents paramètres (géométrie, propriétés de matériau, accessoires de mise en oeuvre) sur le comportement de l’ancrage, une campagne insitu de 36 essais d’arrachement de barres d’acier HA scellées dans un massif calcaire résistant a été réalisée. Certaines barres équipées de fibre optique ont permis d’étudier finement la mobilisation de l’interface entre la barre d’acier et le matériau de scellement lors de la sollicitation axiale. Ces observations expérimentales, comparées aux résultats de la simulation numérique des essais, ont permis de valider le modèle numérique développé et en particulier les éléments d’interface. Par ailleurs, dans nos conditions d’essais, il n’est pas noté d’effet de la longueur de scellement ou de la résistance du coulis de scellement sur la résistance de l’ancrage : la résistance est limitée par la résistance en traction de la barre d’acier. Quant à la rigidité de l’ancrage, c’est le rapport diamètre de la barre/diamètre du forage ou un coulis plus résistant qui tend à rigidifier le comportement de l’ancrage. Pour un rocher résistant et homogène, la longueur de scellement efficace est au maximum de 65cm pour les diamètres usuels de barre. Elle tend à augmenter quand le système est plus déformable : coulis de scellement moins résistant ou, pour un diamètre de barre donné, diamètre de forage plus grand. La présence de la canule d’injection ne semble pas perturber le comportement de l’ancrage. Par contre, une attention particulière doit être portée à la mise en oeuvre de la chaussette géotextile. / Fully grouted rockbolts have been used for decades for transport infrastructure exposed to rockfall hazards. However their installation and maintenance are usually costly. Therefore, understanding and optimizing of the current design method for this type of anchorage is a major challenge. This study is not simple because of the complexity of fully grouted rockbolt behavior: its failure involves not only the failure of constituent materials (rockbolt, grout, rock), but also the failure of bolt-grout and grout-rock interfaces. Moreover, the strength of bolt-grout interface depends on the interface dilatancy, which is likely linked to the geometry of ribs and to the plastification of grout material. This thesis which includes two different parts, a numerical modeling and an experimental work, contributes hence to a better understanding of fully grouted rockbolt behavior under an axial tensile load, in order to improve the current design method. Firstly the bolt-grout interface behavior in particular the force transmission between the bolt and the grout, was studied. For this purpose, a numerical model was proposed to simulate the pull-out test of a short length of 15cm of bolt grouted in a cylinder of cement hardened paste, under constant confinement pressure (Moosavi et al., 2005). In this model, the bolt-grout interface was modeled with its real geometry, including ribs. To consider the different types of behavior and failure (tension, compression and shear) of the grout, this one was modeled by the concrete damage plasticity model (CDP model), which was developed by Lubliner et al. (1986) and implemented in Abaqus (2012). Moreover, the localization of plastic strain and the fracture of grout imply different size effects, which were also taken into consideration within the calibration of the parameters of the CDP model. The bolt-grout interface behavior was also identified to be a cohesive-damage friction interface within a 2 or 3 times the height of the ribs wide shear band. From these numerical modeling results, a constitutive model for the bolt-grout interface was developed to replace the real geometry of bolt-grout contact, in order to model in-situ anchors, whose length is much longer than that of anchors in laboratory tests. The interface model was then validated by performing the numerical simulation of the pullout tests of grouted bolt in borehole drilled in concrete block, carried out by Benmokranne et al. (1995), under constant rigidity of confinement instead of constant pressure of confinement. For the second part of this study, a series of 36 pull-out field tests of fully grouted rockbolt in a rigid limestone rock wall was conducted in order to study the influence of different parameters on the behavior of rock anchors (geometry, material characteristics, accessories). Certain of the bolts equipped with optical fiber allowed bolt strains to be measured along their length, and hence, the stress mobilization along the bolt-grout interface to be studied. The comparison between experimental and numerical results permitted us to validate the numerical simulation, in particular the proposed interface model. With our field test conditions, no influence of grouting length or grout resistance on the strength of anchor was noticed and the bolt strength was limited by the tensile strength of the steel rebar. It is the ratio of bolt diameter/borehole diameter or a stronger grout that tends to stiffen anchor. In a resistant and homogeneous rock and for usual rebar diameters, the efficient grouting length is lower than 65cm. This length increases when the system is more deformable, by using a less resistant grout or a higher grout thickness. The instalation of the cannula seem not to affect the anchor’s strength. However, a particular attention must be paid to the use of the geotextile sock.
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Interactions entre plantes dans un contexte de communauté : une approche expérimentale en Espagne et en Bolivie / Plant-plant interactions in a community background : an experimental approach in Spain and in BoliviaDanet, Alain 17 November 2017 (has links)
Les interactions entre organismes ont des conséquences majeures sur la composition des communautés et le fonctionnement des écosystèmes. En écologie l'étude des interactions négatives, telles que la prédation et la compétition, a largement dominé la littérature. Des travaux récents ont souligné l’importance des interactions positives dans la nature, telles que la facilitation, mais ces interactions restent malgré tout peu intégrées dans les théories contemporaines en écologie. Cette thèse s’inscrit dans cette démarche et aborde deux questions centrales : (i) Comment la facilitation indirecte (via la protection contre le pâturage) affecte-t-elle la structure fonctionnelle (caractéristiques des distributions de traits) des communautés de plantes ? (ii) L'effet net des interactions facilitatrice-bénéficiaire identifiées à l’échelle d’une paire d’espèces restent-elles valides en présence d’une communauté entière d'espèces bénéficiaires potentielles ? Deux expérimentations in situ dans des environnements contrastés ont été mises en place : l’exclusion du pâturage dans des tourbières tropicales alpines et une transplantation de communautés de plantules sous des plantes adultes en milieu méditerranéen semi-aride. Nous avons montré que la facilitation indirecte affectait les caractéristiques du filtre environnemental, la dominance des espèces et la différenciation de niche au sein de la communauté. Nos travaux suggèrent également que la composition des communautés de plantules modifie les interactions adultes-plantules, remettant ainsi en cause la possibilité d’extrapolation des résultats entre paires d'individus à l’échelle de la communauté. / Interactions between organisms are key drivers of community composition and ecosystem functioning. Ecology has a long history of studies on negative interactions, such as predation and competition. Recent studies have highlighted the importance of positive interactions, such as facilitation in nature. The integration of these interactions into modern ecological theory has nonetheless lagged behind. This thesis aims at contributing to this research effort and addresses two core questions : (i) How does indirect facilitation (through protection against grazing) affect the functional structure (characteristics of trait distributions) of plant communities? (ii) Does the net effect of the interactions between a species pair (benefactor-beneficiary) remain valid in the presence of several beneficiary species at community level? We set up two insitu experiments in contrasted environments: a grazing exclusion experiment in tropical alpine peatlands and a transplantation experiment of sapling communities beneath adult plants in a mediterranean environment. Our results showed that indirect facilitation affects the characteristics of the environmental filter, species dominance and niche differentiation in the community. Our results also suggested that the composition of sapling communities modifies adult-sapling interactions, thereby questioning the possibility of extrapolating results from pairs of individuals to the community scale.
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Caracterização dos subtipos moleculares do câncer gástrico por expressão gênica e proteica / Characterization of the molecular subtypes of gastric cancer by gene and protein expressionRamos, Marcus Fernando Kodama Pertille 08 April 2019 (has links)
INTRODUÇÃO: Recentemente, a classificação molecular do câncer gástrico (CG) emergiu como opção promissora para definir subgrupos prognósticos, distinguir o comportamento biológico, além de permitir a identificação de potenciais alvos terapêuticos para drogas específicas. Por meio de técnicas moleculares, o CG foi dividido em 4 subtipos: instabilidade de microssatélites (MSI), vírus Epstein-Barr (EBV)-positivo, genomicamente estável (GS) e instabilidade cromossômica (CIN). Os custos associados à complexidade técnica das metodologias moleculares são ainda um obstáculo para sua implantação na prática de rotina. OBJETIVOS: Determinar os grupos da classificação molecular por meio da expressão proteica de marcadores associados a cada subtipo. Comparar as diferentes classificações moleculares existentes e propor um novo modelo. MÉTODOS: Foram avaliados, retrospectivamente, 287 pacientes com CG submetidos à gastrectomia-D2 curativa, por meio da construção de tissue microarray. A expressão das proteínas de reparo do DNA, E-caderina e p53 foram avaliadas por imuno-histoquímica (IH), determinando os grupos MSI, GS e CIN, respectivamente. O EBV foi detectado por hibridização in situ (ISH). RESULTADOS: Após avaliação histopatológica, 179 (62,4%) pacientes foram classificados como CIN, 58 (20,2%) MSI, 30 (10,5%) EBV e 20 (7%) como GS. Os subtipos associaram-se com características distintas, tais como: gênero masculino (EBV, p=0.101); idade avançada (MSI, p=0,017), menor relação neutrófilo-linfócito (CIN, p=0,029), gastrectomia total (EBV, p < 0,001), localização distal (MSI, p=0,004), Laurén difuso (GS, p < 0,001), e estádio avançado (GS, p=0,014). O subtipo MSI apresentou melhor sobrevida livre de doença (SLD) (82,8%), seguido pelo EBV e CIN (ambos com 70%) e GS (50%) (p=0.005). A sobrevida global (SG) foi maior nos tumores MSI (75,9%), seguido pelo EBV (73,3%), CIN (65.4%) e GS (45%, mediana de 25 meses) (p=0.007). Em análise multivariada, gastrectomia total, pT, pN e os subtipos tumorais foram fatores significativos associados à SLD (MSI p=0,012; EBV p=0,037; CIN p=0,018; GS referência). Do mesmo modo, o tipo de cirurgia, pT, e os subtipos tumorais foram fatores independentes associados a SG (MSI p=0,010; EBV p=0,006; CIN p=0,025; GS referência). Com base no risco de recidiva dos pacientes do estudo, nova classificação, que inclui 5 subtipos, foi proposta. Evidenciou-se que a classificação por risco e cluster tiveram melhor acurácia para identificar recidivas e óbitos respectivamente. CONCLUSÃO: A análise IH/ISH foi capaz de determinar subtipos de CG com características clinicopatológicas e prognósticos distintos, reproduzindo os subtipos obtidos pela classificação molecular / BACKGROUND: Recently, the molecular classification of gastric cancer (CG) emerged as a promising option to define prognostic subgroups, to distinguish biological behavior, and to identify potential therapeutic targets for specific drugs. Through molecular techniques, GC was divided into 4 subtypes: microsatellite instability (MSI), Epstein-Barr virus (EBV) positive, genomically stable (GS) and chromosomal instability (CIN). The costs associated with the technical complexity of the molecular methodologies are still an obstacle to its implementation in routine practice. OBJECTIVES: To determine molecular classification groups by means of protein expression of markers associated with each subtype. To compare the different existing molecular classifications and propose a new model. METHODS: We retrospectively evaluated 287 CG patients submitted to curative D2-gastrectomy through the construction of tissue microarray. Expression of the DNA repair proteins, E-cadherin and p53 were evaluated by immunohistochemistry (IH), determining the MSI, GS and CIN subtypes, respectively. EBV was detected by in situ hybridization (ISH). RESULTS: After the histopathological evaluation, 179 (62.4%) patients were classified as CIN, 58 (20.2%) MSI, 30 (10.5%) EBV and 20 GS (7%) as GS. The subtypes presented associations with distinct characteristics, such as: male gender (EBV, p=0.101); advanced age (MSI, p=0.017), Laurén diffuse type (GS, p < 0.001), lower neutrophil-lymphocyte ratio (CIN, p=0.029), total gastrectomy (EBV, p < 0.001), distal location (MSI, p=0.004), and advanced stage (GS, p=0.014). The MSI subtype presented better disease-free survival (DFS) (82.8%), followed by the EBV and CIN subtypes (both with 70%) and GS (50%) (p=0.005). Overall survival (OS) was higher in MSI tumors (75.9%), followed by EBV (73.3%), CIN (65.4%) and GS (45%, median of 25 months) (p=0.007). In multivariate analysis, total gastrectomy, tumor invasion, lymph node metastasis, and tumor subtypes were significant factors associated with SLD (MSI p=0.012, EBV p=0.037, CIN p=0.018, GS reference). Likewise, type of surgery, pT, and tumor subtypes were independent factors associated with OS (p=0.010, p=0.010, EBV p=0.006, CIN p=0.025, GS reference). Based on the risk of recurrence, a new classification including 5 subtypes was proposed. It was evidenced that the risk classification and cluster had better accuracy to identify recurrences and deaths respectively. CONCLUSION: The IH / ISH analysis was able to determine CG groups with clinicopathological characteristics and distinct prognoses, reproducing the subtypes obtained by the molecular classification
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Effet de la cristallochimie des minéraux argileux gonflants sur les propriétés d'échange cationique et de dissolution. Implications dans un contexte de réhabilitation de sites miniers acidifiés / Effect of the crystal chemistry of swelling clay minerals on their cationic exchange and dissolution properties. Implications in a context of remediation of acid mining environmentRobin, Valentin 04 December 2015 (has links)
Les smectites sont présentent dans de nombreux environnements de surface et sub-surface au sein desquels elles jouent un rôle prépondérant dans la mobilité des cations majeurs et traces de part leurs capacités d’adsorption. En contexte de réhabilitation de sites miniers exploités par lixiviation acide, ces smectites jouent un rôle dans la remontée du pH des eaux ainsi que dans l’immobilisation des éléments solubilisés. La nature des argiles présentent dans les sables non consolidés d’un aquifère exploité a donc été étudié. La présence de smectites du type beidellite (charge tétraédrique) a été mise en évidence. Cependant, il existe peu d’études sur les propriétés de la beidellite, la majorité portant sur la montmorillonite (charge octaédrique). Un modèle d’échange pour 5 cations majeurs des eaux naturelles (Na, K, Ca, Mg, H) et un élément trace (226Ra) a donc été réalisé sur une beidellite de référence. Les vitesses de dissolution et les mécanismes à l’interface solide/solution en milieu acide ont ensuite été étudiés, validant l’application du modèle d’échange à bas pH. Des effets dus à l’organisation des particules en suspension (texture/agrégation) ont aussi été mis en évidence sur les propriétés d’échange et de dissolution. Lors de ces travaux, l’accent a été mis sur l’impact de la cristallochimie sur la réactivité des smectites par comparaison entre les propriétés de la beidellite et de la montmorillonite. Les résultats indiquent que la cristallochimie des smectites a un impact significatif sur leur comportement, ce paramètre pourrait ainsi être utilisé afin d’alimenter les modèles de transport réactif prenant en compte les propriétés des smectites. / Swelling clay minerals, in particular smectites, are present in many surface and subsurface environments in which they have a major impact on the mobility of major cations and trace elements due to their adsorption capacity. In context of remediation of mining environments operated by acid leaching, these smectites can act as pH buffer and play a role in the immobilization of soluble elements. The type of clay minerals present in the poorly consolidated sands of an aquifer leached by acid solutions was studied. The presence of beidellite type smectites (di-octahedral, tetrahedral charge) was evidenced. However, few studies exist on the ion exchange properties or the dissolution of beidellite, as most of them deal with montmorillonite properties (di-octahedral, octahedral charge). Then, an ion-exchange model involving 5 major cations of natural waters (Na, K, Ca, Mg, H) and one trace element (226Ra) was proposed for a reference beidellite. Dissolution rates and interfacial mechanisms in acidic solutions were investigated in order to check for the validity the ion-exchange model at low pH. Moreover, effects due to the texture/aggregation of particles in suspension were evidenced on the ion-exchange and dissolution properties. This study was focused on the impact of the crystal chemistry on reactive property of the smectites, by comparison of the properties of beidellite with those of montmorillonitic minerals. Results indicate that smectites crystal chemistry has a significant impact on their properties, and such parameter could be considered in reactive transport models when they take into account cation exchange and dissolution properties of smectites.
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Caracterização molecular de proteínas secretadas da família VAL (Venon Allergen-Like Protein) de Schistosoma mansoni e avaliação como antígenos vacinais. / Molecular characterization of secreted proteins of Schistosoma mansoni VAL (Venom Allergen-Like Protein) family and evaluation as vaccine candidates.Fernandes, Rafaela Sachetto 02 March 2016 (has links)
A esquistossomose é uma doença causada por trematódeos do gênero Schistosoma. Dentre os genes identificados no transcriptoma do parasita, membros da família gênica SmVAL (Schistosoma mansoni Venom Allergen-Like) foram apontados como candidatos vacinais. SmVALs foram identificadas em secreções de cercárias e esquistossômulos cultivados in vitro, os transcritos SmVAL4 e 24 foram localizados nas glândulas acetabulares de germ ball e a proteína nativa SmVAL4 foi identificada em extrato de cercárias, indicando funções durante a penetração da pele. Já os transcritos SmVAL13 e 14 foram localizados na glândula esofágica anterior de vermes adultos, sugerindo papéis no processo de alimentação sanguínea. A imunização com as proteínas rSmVAL4, 6, 7, 13, 14 e 18 coadministradas não protegeu camundongos contra o desafio experimental, porém, observou-se uma diminuição do número de fêmeas e do número de ovos no grupo imunizado. A investigação de funções para as proteínas secretadas mostrou que a rSmVAL18 interage com plasminogênio in vitro favorecendo a invasão do hospedeiro. / Schistosomiasis is a disease caused by trematodes of the genus Schistosoma. Among the genes identified in the parasite transcriptome, members of SmVAL (Schistosoma mansoni Venom Allergen-Like) gene family were proposed as vaccine candidates. SmVALs were identified in cercariae and schistosomule secretions in vitro, the SmVAL4 and 24 transcripts were located to the germ ball acetabular glands and SmVAL4 native protein was identified in cercariae extract, indicating functions in skin penetration. On the other hand, SmVAL13 and 14 transcripts were located to the anterior esophageal gland of adult worms, suggesting roles in the blood feeding processes. Immunization with rSmVAL4, 6, 7, 13, 14 and 18 proteins co-administered did not protected mice against experimental challenge, however, there was a decrease in the number of females and the number of eggs in the immunized group. The investigation of functions for secreted proteins showed that rSmVAL18 interacts with plasminogen in vitro thus favoring the host invasion.
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Fatores morfológicos, moleculares e do microambiente relacionados ao risco de invasão estromal em carcinomas ductais in situ da mama / Morphologic, molecular and microenvironment factors associated with stromal invasion in breast ductal carcinoma in situAguiar, Fernando Nalesso 11 August 2014 (has links)
INTRODUÇÃO: O carcinoma ductal in situ da mama é o estágio final antes do carcinoma ductal invasivo (CDI) no processo de carcinogênese mamária. As semelhanças histológicas, moleculares e imunoistoquímicas do epitélio nestas duas lesões tornaram improvável que o epitélio fosse o único responsável pelo processo de invasão estromal. Ao mesmo tempo, foram identificadas importantes alterações nas características do microambiente mamário durante esta transição. As células mioepiteliais, componente do microambiente e cuja rotura determina o diagnóstico histológico do carcinoma invasivo, tem papel direto ou indireto neste processo. A fim de predizer esse risco de invasão, propomos que as características das células mioepiteliais sejam investigadas em conjunto com as características intrínsecas do epitélio neoplásico. OBJETIVOS: Determinar os fatores morfológicos e moleculares das células epiteliais e os marcadores das células mioepiteliais do microambiente em carcinomas ductais in situ da mama relacionados ao risco de invasão estromal. MÉTODOS: Foram selecionados retrospectivamente 236 casos consecutivos com diagnóstico inicial de CDIS seguidos de ressecção cirúrgica na Divisão de Anatomia Patológica da Faculdade de Medicina da Universidade de São Paulo no período de janeiro de 2000 a dezembro de 2009, divididos nos grupos 1 (CDIS puro, 90 casos) e 2 (CDIS associado a carcinoma invasor, 146 casos). Blocos de microarranjos de tecido foram construídos com áreas representativas dos CDIS e CDI que foram, então, classificados nos perfis moleculares de acordo com o seu perfil imunoistoquímico. Os marcadores mioepiteliais (vimentina, AML, calponina, p63, CK5/6, SMMHC, CD10) foram avaliados de acordo com a expressão imunoistoquímica baixa ou alta. RESULTADOS: Os perfis moleculares dos componentes in situ e invasivo da mesma lesão foram semelhantes. Os CDIS de baixo grau histológico, em comparação aos CDIS de alto grau, apresentaram maior número de casos com perfil molecular luminal (143 vs. 18) e menor proporção de casos luminal/HER2-positivo (6 vs. 11), HER2 (4 vs. 27) e triplo-negativo (3 vs. 22). Os CDIS no grupo 1, em relação aos CDIS no grupo 2, tiveram maior proporção de casos com expressão de receptores hormonais (84.4% vs. 71,2%) menor expressão de HER2 (76,7% vs. 81,5%), mais perfis moleculares luminal/HER2-positivo (12,2% vs. 4,1%) e menos perfis triplo-negativos (4,4% vs. 14,4%). A expressão de CK5/6 nas células epiteliais do CDIS teve maior proporção entre o subtipo HER2 (34,5%), seguido pelo triplo-negativo (25%), luminal/HER2- negativo (15,4%) e luminal/HER2-positivo (12,5%). A expressão de CK5/6 foi maior nas células epiteliais dos CDIS do grupo 1 em relação aos CDIS do grupo 2 (30,6% vs. 11,3%). A expressão alta de SMMHC nas células mioepiteliais associou-se mais frequentemente aos CDIS do grupo 1 (88,2%) em relação aos CDIS do grupo 2 (11,8%), e esta diferença manteve-se tanto nos CDIS de baixo grau (85,7%) quanto nos de alto grau histológico (92,3%). A expressão baixa de CD10 nas células mioepiteliais associou-se mais frequentemente aos CDIS do grupo 2 (95,6%) em relação aos CDIS do grupo 1 (4,4%), e esta diferença manteve-se tanto nos CDIS de baixo grau (96,4%) quanto nos de alto grau histológico (94,1%). Não houve diferença na expressão de marcadores mioepiteliais de acordo com o perfil molecular baseado na imunoistoquímica. CONCLUSÕES: O risco de invasão estromal em CDIS está associado ao perfil molecular triplo-negativo e à perda de expressão do marcador CD10 pelas células mioepiteliais e é inversamente proporcional à expressão de CK5/6 pelas células neoplásicas e à forte expressão do marcador SMMHC nas células mioepiteliais / INTRODUCTION: Ductal carcinoma in situ is the last step preceding invasive ductal carcinoma in breast carcinogenesis. Histologic, molecular and immunohistochemistry similarities in epithelium of these components make improbable that epithelial changes are sole responsible for the stromal invasion. At the same time important changes were identified in mammary microenvironment during this transition. Myoepithelial cells, components of microenvironment and which rupture is the histological definition of stromal invasion, have a direct or indirect role in this process. We propose an associated investigation of myoepithelial cells and intrinsic neoplastic epithelium caracteristics in view of predict the risk of stromal invasion. OBJECTIVES: To determinate morphologic and molecular factors of epithelial cells and microenvironment myoepithelial cell markers related to stromal invasion risk in ductal carcinomas in situ of the breast. METHODS: 236 cases with initial diagnosis of DCIS followed by surgical ressection were retrospectively selected from Division of Surgical Pathology, Faculty of Medicine, Sao Paulo University from january 2000 to december 2009, divided in groups 1 (pure DCIS, 90 cases) and 2 (DCIS associated with invasive carcinoma, 146 cases). Tissue microarrays were constructed with selected areas of DCIS and IDC and those were then classificated in molecular subgroups according to its immunohistochemistry profile. Myoepithelial markers (vimentin, smooth muscle actin, calponin, p63, CK5/6, SMMHC, CD10) were avaliated according to its high or low immunohistochemistry expression. RESULTS: Molecular profiles of in situ and invasive components of the same tumor were similar. Low-grade DCIS showed more luminal profiles than highgrade DCIS (143 vs. 18), and less luminal/HER2-positive (6 vs. 11), HER2 (4 vs. 27) and triple-negative (3 vs. 22) profiles. Group 1 DCIS, compared to group 2 DCIS, showed more cases with hormonal receptor expression (84.4% vs. 71.2%), less expression of HER2 (76.7% vs. 81.5%), more luminal/HER2-positive (12.2% vs. 4.1%) and less triple-negative profiles (4.4% vs. 14.4%). CK5/6 expression in epithelial cells was more frequent in HER2 (34.5%) subtype followed by triple-negative (25%), luminal/HER2-negative (15.4%) and luminal/HER2-positive (12.5%). Epithelial cells in group 1 DCIS showed more CK5/6 expression than cells in group 2 DCIS (30.6% vs. 11.3%). High expression of SMMHC in myoepithelial cells was more frequent in group 1 DCIS (88.2%) than group 2 DCIS (11.8%) and this pattern was also mantained in low-grade DCIS (85.7%) and high-grade DCIS (92.3%). Low expression of CD10 in myoepithelial cells was more frequent in group 2 DCIS (95.6%) than group 1 DCIS (4.4%) and this pattern was also mantained in low-grade (96.4%) and high-grade DCIS (94.1%). There was no significant difference in expression of myoepithelial cells according to molecular profile classified by immunohistochemistry. CONCLUSIONS: Stromal invasion risk in DCIS is associated with triple-negative profile, CD10 expression loss in myoepithelial cells and inversely correlated with CK5/6 expression in neoplastic cells and high expression of SMMHC in myoepithelial cells
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Linfoma de Burkitt: características clinicopatológicas, imunoistoquímicas e associação com o vírus de Epstein-Barr (EBV) em populações adulta e pediátrica em diferentes regiões geográficas no Brasil / Burkitt lymphoma: clinicopathologic, immunohistochemical and association with Epstein-Barr virus (EBV) in adult and pediatric population in different geographical regions of BrazilQueiroga, Eduardo Moreira de 13 December 2008 (has links)
O linfoma de Burkitt (LB) é neoplasia linfóide de células B de alto grau que apresenta translocação constante envolvendo o proto-oncogene C-MYC. A associação com o vírus de Epstein-Barr (EBV) varia de acordo com a forma clinicopatológica. O presente estudo tem por objetivo analisar as características clinicopatológicas, imunoistoquímicas, incluindo a expressão do fator de transcrição MUM1/IRF4 e das proteínas p53 e p63, e investigar a associação com infecção pelo Herpesvírus humano 8 (HHV-8) e EBV, através de hibridização in situ e PCR, em 234 casos bem caracterizados de LB no Brasil, provenientes das 5 regiões geográficas em pacientes pediátricos e adultos, incluindo casos associados ao HIV. As características clínicas do LB no Brasil, de maneira geral, foram semelhantes às observadas na forma esporádica do LB ocorrendo nos países desenvolvidos. A infecção pelo EBV foi observada em 52,5% dos casos. A maior associação com EBV foi verificada nas regiões Norte e Nordeste e a menor na região Sul. Através de PCR, demonstrou-se predomínio de EBV do tipo A, sendo exceção a região Centro-Oeste. O fator de transcrição MUM1/IRF4 foi expresso em 39,2% dos tumores e apresentou correlação inversa com infecção pelo EBV. A expressão das proteínas p53 e p63 foi observada em 16,2% e 3,8% dos casos, respectivamente. Não se identificou infecção pelo HHV-8. O LB no Brasil apresenta características clinicopatológicas variáveis entre as regiões geográficas. A associação com infecção pelo EBV é intermediária entre a forma endêmica de LB e a forma esporádica ocorrendo em países desenvolvidos, sendo maior em regiões com indicadores sociais menos favoráveis. / Burkitt lymphoma (BL) is a high grade B cell lymphoma with a consistent translocation involving the proto-oncogene C-MYC. The association with the Epstein-Barr virus (EBV) varies depending on the clinicopathological form. This study aims to analyze the clinicopathologic, immunohistochemical features, including the expression of transcription factor MUM1/IRF4 and p53 and p63 proteins, and investigate the association with infection by human herpesvirus-8 (HHV-8) and EBV, by in situ hybridization and PCR, in 234 well-characterized cases of BL in Brazil from the 5 different geographic regions, in adult and pediatric patients, including HIV associated cases. The clinical characteristics of BL in Brazil, in general, were similar to those observed in the sporadic form of BL occurring in developed countries. EBV infection was seen in 52.5% of cases. The strongest association with EBV was found in the North and Northeast and the lowest in the South. PCR study demonstrated predominance of EBV type A, except in the Central-West region. The transcription factor MUM1/IRF4 was expressed in 39.2% of the tumors and showed inverse correlation with EBV infection. The expression of p53 and p63 proteins was observed in 16.2% and 3.8% of cases, respectively. No evidence of HHV-8 infection was found. The BL in Brazil is clinicopathologic diverse and regionally distinct. The association with EBV infection is intermediate between the endemic form of BL and sporadic form occurring in developed countries and is higher in regions with the less favorable social indicators
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Desenvolvimento de prensa para conformação superplástica com sistema de controle in situ e tempo real de pressão e de temperatura e com módulo de monitoramento da deformação por correlação digital de imagem. / Press development for superplastic forming with in situ and real time pressure and temperature control system and module with digital image correlation for strain monitoring.Marinho, Erick Petta 14 July 2016 (has links)
Esta tese contempla o desenvolvimento de uma prensa para conformação biaxial superplástica com sistema de controle in situ e real time de pressão e de temperatura, como também um módulo de monitoramento de deformação através da técnica de correlação digital de imagem. A referida prensa é capaz de atingir durante a conformação ótimas condições superplásticas através da instrumentação e do controle dedicado dos parâmetros que caracterizam o processo de conformação fluidoestática biaxial, pressão, temperatura e taxa de deformação. São seis os principais temas abordados e desenvolvidos nessa tese: (a) técnicas, métodos e requisitos da superplasticidade da liga de titânio Ti6Al4V; (b) concepção e construção da prensa que atenda aos requisitos do projeto; (c) instrumentação do ferramental; (d) implementação do sistema de controle; (e) definição e aplicação de metodologia de ensaio superplástico para conformação fluidoestática biaxial e (f) fabricação da peça modelo. A aplicação e desenvolvimento do sistema de controle em expansão fluidoestática biaxial envolve desde a escolha das condições de conformação, determinação do ciclo de pressão, implementação de controles dedicados que atendam aos requisitos de conformação até os métodos de determinação dos coeficientes de interesse (m, n e K). Com tal instrumentação é possível determinar os coeficientes a partir de ensaios biaxiais, ao invés de simplesmente utilizar os coeficientes de ensaios de tração uniaxiais. Realizou-se um ensaio superplástico fluidoestático biaxial de chapas de liga de Ti6AL4V controlado em torno de sua condição ótima. Em suma sobre o controle, o sistema de controle térmico minimiza o intervalo de tempo de estabilização da temperatura, sem sobressinal, reduzindo o tempo de exposição do material superplástico a altas temperaturas; o sistema de controle de pressão aplica um ciclo de pressurização que é responsável por realizar a conformação de forma que resulte em uma taxa de deformação específica que represente a condição de maior índice de sensibilidade a taxa de deformação, assim se caracteriza como ponto ótimo do processo. Os principais resultados são o Ferramental instrumentado e controlado para realização de conformação superplástica em atmosfera controlada e os sistemas de controle de temperatura, pressão e deformação, validados e testados de forma integrada em ensaios de conformação superplástica / This thesis contemplates the full development of a superplastic biaxial forming Press which contains an in situ and real time pressure and temperature control systems, as well as a deformation monitoring module that applies digital image correlation technique. The Press can achieve optimum superplastic forming conditions supported by dedicated instrumentation and control of the parameters that characterize the superplastic forming process; these parameters are pressure, temperature and strain rate. Six main topics are discussed: (a) techniques, methods and Ti6Al4V alloy superplastic requirements; (b) design and construction of the press that meets the project requirements; (c) Press instrumentation; (d) control system implementation; (e) definition and implementation of a new superplastic test methodology for bulge test and (f) a part model manufacturing. The application and development of the control system in biaxial forming process involves the selection of forming conditions, pressure cycle determination, implementation of dedicated controls that meet the forming requirements, besides methods for calculating important coefficients (m, n K). With the referred instrumentation, it is possible to determine these coefficients from biaxial tests, rather than simply using the uniaxial tensile tests coefficients. A Ti6Al4V alloy fluid static superplastic biaxial test was conducted, controlled around its optimum condition. Summarizing the control system, the thermal control system minimizes the stabilization temperature time, avoiding temperature overshooting, reducing the material time exposure at superplastic temperatures. The pressure control system applies a pressurization cycle, responsible for conducting the forming process, to achieve a specific strain rate. This represents the condition of maximum strain rate sensitivity, thus characterized as optimal process point. The main results are the instrumented and controlled superplastic biaxial forming Press efficient to conduct superplastic forming in a controlled atmosphere, and temperature, pressure and deformation control systems validated and tested in an integrated Superplastic forming tests.
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Avaliação do desgaste superficial do esmalte e da dentina radicular submetidos ao tratamento clareador: in vitro e in situ / Evaluation of enamel and root dentin surface wear submitted to bleaching treatment: in vitro and in situRomano, Juliana Jendiroba Faraoni 16 May 2008 (has links)
Devido a alterações químico-estruturais causadas pelo clareamento, os substratos dentais poderiam tornar-se mais susceptíveis a perda tecidual, principalmente se expostos a desafios erosivo/abrasivos. Desta forma, o presente estudo teve como objetivos: 1) analisar in vitro, se o esmalte e a radicular dentina clareada com diferentes agentes e concentrações, apresenta uma maior susceptibilidade ao desgaste, quando submetido a ciclos de erosão e abrasão; 2) comparar o efeito da aplicação de um agente clareador a base de peróxido de carbamida a 10% a um placebo no desgaste do esmalte e da dentina radicular, através de um modelo in situ. Os resultados do estudo in vitro mostraram que, independentemente do agente usado, o clareamento não aumentou o desgaste do esmalte frente a episódios erosivo-abrasivos. Na dentina, o desgaste foi dependente do agente clareador aplicado. Baseado no protocolo in situ adotado, o peróxido de carbamida a 10% não causou maior desgaste superficial no esmalte, mas aumentou a perda de tecido dentinário comparado ao placebo. Pode-se concluir que, em termos de desgaste superficial, o esmalte não foi afetado pelo tratamento clareador, enquanto a dentina mostrou-se mais susceptível. Assim, sugerem-se cuidados adicionais na seleção do agente clareador em situações clínicas que apresentam dentina radicular exposta. / Due to the chemical and microstructural alterations caused by bleaching, the dental substrates can become more susceptible to tissue loss, mainly if exposed to erosive/abrasive challenges. Therefore, the present study had the following objectives: 1) to analyze in vitro, if enamel and root dentin that had been bleached with different agents and concentrations, were at increased risk of wear when submitted to cycles of erosion and abrasion; 2) to compare the effect of the application of a 10% carbamide peroxide bleaching agent to a placebo on wear of enamel and root dentin, through an in situ model. The results of the in vitro study showed that independent of agent used, the bleaching demonstrated no increase in the wear of enamel when exposed to the erosive-abrasive episodes. In dentin, the wear was dependent on the bleaching agent applied. Based on the in situ protocol adopted, the 10% carbamide peroxide did not cause higher wear on the enamel, but increased the wear of the root dentin compared to the placebo. It could be concluded that in terms of superficial wear, enamel was not affected by bleaching treatment, while dentin showed to be more susceptible. Thus, additional caution is suggested in the choice of the bleaching agent when root dentin is exposed.
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Avaliação de formulações de uso tópico a base de insulina no distúrbio das glândulas lacrimais e na regeneração da córnea em ratos diabéticos / Evaluation of topical formulations based insulin disorder of lacrimal glands and in the regeneration of the cornea in diabetic ratsCruz, Estael Luzia Coelho Madeira da 18 July 2014 (has links)
Distúrbios na superfície da córnea e nas glândulas lacrimais acometem com frequência os indivíduos com diabetes mellitus. Atualmente não existe tratamento seguro e eficaz para feridas na córnea e o tratamento da síndrome do olho seco (SOS) é predominantemente sintomático. A administração tópica da insulina (INS) é uma estratégia promissora para tratar esses distúrbios, devido à presença de seus receptores na superfície ocular e na glândula lacrimal, e aos seus efeitos metabólicos e mitogênicos. No entanto, os fármacos aplicados topicamente na forma de solução são rapidamente drenados do olho, resultando em uma baixa biodisponibilidade local. O objetivo deste trabalho foi desenvolver formulações contendo INS e avaliar a sua influência no distúrbio das glândulas lacrimais e na regeneração da córnea em ratos diabéticos. Foram desenvolvidas quatro formulações contendo 1 UI/mL de INS: dispersão contendo insulina (DISP INS), dispersão contendo micropartículas quitosana/INS (DISP MP INS), gel termorreversível in situ com INS (Gel INS) e Gel contendo as micropartículas quitosana/INS (Gel MP INS). Também foram produzidas formulações \"brancas\", sem a veiculação do fármaco: dispersão contendo micropartículas sem insulina (DISP MP s/INS); gel termorreversível in situ sem insulina (Gel s/INS). As MP incorporadas nas formulações foram preparadas por spray drying e apresentaram tamanho de 4,0±0,1 ?m, morfologia adequada e grande quantidade de INS (77±6%). Todas as formulações apresentaram pH e osmolalidade compatíveis com o uso ocular. Durante o estudo in vivo, foi realizado o tratamento diário (15 dias) dos animais diabéticos, com as formulações (50 ?L) em ambos os olhos, exceto nos controles positivo (sem diabetes) e controle negativo (diabético não tratado). Todos os animais tratados com INS aumentaram a produção de fluido lacrimal, sendo que, ao término do tratamento, não foi observada diferença estatística entre o controle positivo e aqueles tratados com DISP INS e com Gel MP INS. A INS foi detectada na glândula lacrimal e no globo ocular dos animais tratados com DISP MP INS, Gel INS e Gel MP INS, sendo que a maior concentração de INS foi encontrada nos ratos tratados com Gel MP INS. Ao término do tratamento houve redução da glicemia dos animais tratados com a INS, o que pode sugerir um tratamento coadjuvante em pacientes diabéticos. Estudos de citologia de impressão mostraram que o Gel INS e Gel MP INS foram capazes de aumentar o número de células do epitélio da córnea e melhorar a relação núcleo/citoplasma em relação ao controle negativo. A histologia do globo ocular mostrou que essas duas formulações também melhoraram a espessura do epitélio da córnea, que foi semelhante a dos controles positivos. Conclui-se que a incorporação da INS nos géis e nas micropartículas desenvolvidas desempenhou um efeito positivo no tratamento da síndrome do olho seco e de lesões na córnea. / Disorders in the corneal surface and the lachrymal glands often affect individuals with diabetes mellitus. Nowadays there is no safe and effective treatment for wounds in the cornea and the treatment of dry eye syndrome (DES) is primarily symptomatic. Topical administration of insulin (INS) is a promising strategy for treating these disorders due to the presence of receptors on the ocular surface and lacrimal gland, besides its metabolic and mitogenic effects. However, the drugs applied topically in the form of a solution are quickly drained from the eye, resulting in a low local bioavailability. The aim of this study was to develop formulations containing INS and evaluate their influence on disorders of lacrimal glands and cornea healing in diabetic rats. Four formulations containing 1 IU/mL of INS were developed: dispersion containing insulin (DISP INS), dispersion containing chitosan microparticles/INS (DISP MP INS), in situ forming gel containing INS (Gel INS) and in situ forming gel containing microparticles chitosan/INS (Gel MP INS). \"White\" formulations were also produced without the drug: dispersion containing microparticles without insulin and in situ forming gel without insulin. MP incorporated in the formulations were prepared by spray drying and showed size of 4.0±0.1 ?m, proper morphology and high INS load (77±6%). All formulations exhibited pH and osmolarity compatible with the ocular use. In vivo studies were performed using diabetic rats that were treated daily (15 days) with instillation of the formulations (50 ?L) in both eyes, except in the positive controls (health rats) and negative control (untreated diabetic rats). All animals treated with INS showed an increase in the production of tear fluid. After treatment, no statistical difference was observed between the positive control and those treated with DISP INS and Gel MP INS. The INS was detected in the lacrimal gland of the animals treated with DISP MP INS, Gel INS and Gel MP INS, with the highest concentration of INS found in mice treated with Gel MP INS. After treatment there was a reduction in blood glucose of the animals treated with formulations containing INS, which suggests that developed formulations may be used as an adjuvant treatment in diabetic patients. Impression cytology studies showed that the Gel INS and Gel MP INS were able to increase the number of the corneal epithelium cells and improve nucleus/cytoplasm ratio compared to the negative control. The histology of the eyeball showed that these two formulations have improved the thickness of the corneal epithelium, which was similar to the positive controls. In conclusion, incorporation of INS in the gels and MP developed induced a positive effect in the treatment of dry eye syndrome and corneal wound.
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