The function of skeletal adaptation to mechanical load is to adjust the amount and distribution of bone tissue (geometry); such that stresses experienced within the bone are kept within certain physiological limits and fractures are prevented. Genetic, environmental or hormonal factors may cause heterogeneity in this adaptive response, altering geometry and consequently fragility. The purpose of this thesis was to explore the skeletal response to load in vivo, by evaluating stress at the hip under three different conditions: FRACTURE (Study 1), DIABETES (Study 2) and ESTROGEN deficiency (STUDY 3). We studied women 25 years of age or older who participated in the Canadian Multicentre Osteoporosis Study and had available Hip Structure Analysis (HSA) data from baseline dual energy x-ray absorptiometry (DXA) scans. Women were categorized according to fracture status (fracture or no fracture), diabetes status (diabetes or no diabetes) and estrogen use (current users or never users). We computed stress (megapascals=MPa) at the infero-medial margin of the femoral neck in a one-legged iii stance using a 2-D engineering beam analysis. We used linear regression to determine associations between femoral neck stress and each categorical variable. Study 1 (n=2168) demonstrated higher stresses in postmenopausal women with fractures compared to women without fractures (10.57 ± 2.19 vs. 10.30 ± 2.03 MPa; p=0.0031). Study 2 (n=3665) demonstrated higher stresses in women with Type 2 Diabetes Mellitus compared to non-diabetic women (10.98 ± 2.33 vs. 10.57 ± 2.20 MPa; p=0.0194). Study 3 (n=2447) demonstrated higher stresses in postmenopausal women not on estrogen than in premenopausal women (10.66 ± 2.14 vs. 10.09 ± 2.01 MPa; p<0.0001), but no differences in stresses between postmenopausal women on estrogen and premenopausal women (10.16 ± 2.00 vs. 10.09 ± 2.01 MPa; p=0.6102). Since stress is an indicator of underlying geometry, and geometry should be adapted to prevalent loads, higher stress indicates weaker geometry and suggests an impaired modeling response in these three conditions. Compromised modeling has important clinical implications in terms of treatment selection, as individuals with reduced load sensitivity may respond best to metabolic agents that would improve modeling responses to load stimuli.

The function of skeletal adaptation to mechanical load is to adjust the amount and distribution of bone tissue (geometry); such that stresses experienced within the bone are kept within certain physiological limits and fractures are prevented. Genetic, environmental or hormonal factors may cause heterogeneity in this adaptive response, altering geometry and consequently fragility. The purpose of this thesis was to explore the skeletal response to load in vivo, by evaluating stress at the hip under three different conditions: FRACTURE (Study 1), DIABETES (Study 2) and ESTROGEN deficiency (STUDY 3). We studied women 25 years of age or older who participated in the Canadian Multicentre Osteoporosis Study and had available Hip Structure Analysis (HSA) data from baseline dual energy x-ray absorptiometry (DXA) scans. Women were categorized according to fracture status (fracture or no fracture), diabetes status (diabetes or no diabetes) and estrogen use (current users or never users). We computed stress (megapascals=MPa) at the infero-medial margin of the femoral neck in a one-legged iii stance using a 2-D engineering beam analysis. We used linear regression to determine associations between femoral neck stress and each categorical variable. Study 1 (n=2168) demonstrated higher stresses in postmenopausal women with fractures compared to women without fractures (10.57 ± 2.19 vs. 10.30 ± 2.03 MPa; p=0.0031). Study 2 (n=3665) demonstrated higher stresses in women with Type 2 Diabetes Mellitus compared to non-diabetic women (10.98 ± 2.33 vs. 10.57 ± 2.20 MPa; p=0.0194). Study 3 (n=2447) demonstrated higher stresses in postmenopausal women not on estrogen than in premenopausal women (10.66 ± 2.14 vs. 10.09 ± 2.01 MPa; p<0.0001), but no differences in stresses between postmenopausal women on estrogen and premenopausal women (10.16 ± 2.00 vs. 10.09 ± 2.01 MPa; p=0.6102). Since stress is an indicator of underlying geometry, and geometry should be adapted to prevalent loads, higher stress indicates weaker geometry and suggests an impaired modeling response in these three conditions. Compromised modeling has important clinical implications in terms of treatment selection, as individuals with reduced load sensitivity may respond best to metabolic agents that would improve modeling responses to load stimuli.

During recent years, the importance of utilizing more computational power in smaller computersystems has increased. The utilization of more computational power in smaller packages, the abil-ity to combine more than one type of processor unit has become more popular in the industry. By combining, one achieves more power efficiency as well as gain more computational power insmaller area. However, heterogeneous programming has proved to be difficult, and that makes soft-ware developers diverge from learning heterogeneous programming languages. This has motivatedHSA foundation to develop a new hardware architecture, called Heterogeneous System Architecture(HSA). This architecture brings features that make the process of heterogeneous programming de-velopment more accessible, efficient, and easier to the software developers. The purpose of thisthesis is to investigate this new architecture, to learn and observe the timing characteristics of atask running a parallel region (a kernel) on a GPU in an HSA compliant system. With an objectiveto gain more knowledge, four test cases have been developed to collect time data and to analyzethe time of the code executed on the GPU. These are: comparison between CPU and GPU, tim-ing predictability of parallel periodic tasks, schedulability in HSA, and memory copy. Based onthe results of the analysis, it has been concluded that the HSA has potential to be very attractivefor developing heterogeneous programs due to its more streamlined infrastructure. It is easier toadapt, requires less knowledge regarding the underlying hardware, and the software developers canuse their preferred programming languages, instead of learning new programming framework, suchas OpenCL. However, since the architecture is new, there are bugs and HSA features that are yetto be incorporated into the drivers. Performance wise, HSA is faster compared to legacy methods,but lacks in providing consistent time predictability, which is important for real-time systems.

No description available.

Este trabalho trata do estudo de complexos de rutênio contendo antiinflamatórios não-esteróides, com o objetivo de contribuir para ampliar as pesquisas na área de potenciais metalofármacos antitumorais. A partir de reações do precursor dimetálico [Ru2(O2CCH3)4Cl] com os fármacos carboxílicos sulindaco (HSulin) e diclofenaco de sódio (NaDiclofen) foram isolados, respectivamente, os correspondentes complexos [Ru2(Sulin)4Cl] e [Ru2(Diclofen)4Cl]. A reação entre o monômero [RuCl2(dmso)4] e o meloxicam (H2Melox) deu origem ao derivado misto [Ru(dmso)2(HMelox)2]. Os compostos foram caracterizados por meio de análise elementar, medidas de condutância molar, medidas de susceptibilidade magnética, espectroscopia de absorção eletrônica UV-VIS-IR, espectroscopia vibracional FTIR e Raman, e estudos de análise térmica (TG/DSC/MS). As interações da albumina de soro humana HSA, importante proteína do plasma, com os complexos obtidos, com o análogo [Ru2(IBP)4Cl] (HIBP = ibuprofeno) e também com os fármacos orgânicos não-complexados foram investigadas empregando-se dicroísmo circular, SDS-Page e fluorescência. A atividade antitumoral dos metalofármacos foi avaliada, através de ensaios com MTT, com base nos seus efeitos citotóxicos para a linhagem celular de leucemia humana K562. / This work describes the study of ruthenium complexes containing non-steroidal antiinflammatory drugs with the aim of helping to expand the research in the field of potential anticancer metallodrugs. Reactions of the [Ru2(O2CCH3)4Cl] dimetal complex with sulindac (HSulin) and sodium diclofenac (NaDiclofen) carboxylic drugs gave the correspondent complexes [Ru2(Sulin)4Cl] and [Ru2(Diclofen)4Cl], respectively. The reaction between the [RuCl2(dmso)4] monomer and the meloxicam drug (H2Melox) led to the mixed derivative [Ru(dmso)2(HMelox)2]. The compounds were characterized by elemental analysis, molar conductance measurements, magnetic susceptibility, UV-VIS-IR electronic absorption spectroscopy, Raman and FTIR vibrational spectroscopies and by studies of thermal analysis (TG / DSC / MS). The interactions of human serum albumin (HSA), the major plasma protein, with the obtained complexes, the analogous [Ru2(IBP)4Cl] (= HIBP ibuprofen) and also with the noncoordinated organic drugs have been investigated by circular dichroism, SDS-Page and fluorescence. The antitumor activity of the metallodrugs has been evaluated by MTT assays, on the basis of their cytotoxic effects on K562 human leukemia cell line.

Submitted by Franciele Moreira (francielemoreyra@gmail.com) on 2019-01-31T13:01:42Z No. of bitstreams: 2 Dissertação - Juliana Fracalossi Paes - 2018.pdf: 3499755 bytes, checksum: 913f34f36a97b5b7412e4eec7b1af1c1 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2019-02-01T10:04:10Z (GMT) No. of bitstreams: 2 Dissertação - Juliana Fracalossi Paes - 2018.pdf: 3499755 bytes, checksum: 913f34f36a97b5b7412e4eec7b1af1c1 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2019-02-01T10:04:10Z (GMT). No. of bitstreams: 2 Dissertação - Juliana Fracalossi Paes - 2018.pdf: 3499755 bytes, checksum: 913f34f36a97b5b7412e4eec7b1af1c1 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-09-27 / Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG / Introduction: MicroRNAs are small molecules of single-stranded non-coding RNAs that regulate gene expression in the post-transcriptional phase and are being evaluated as prognostic and predictive markers in breast cancer. Objective: The aim of this study was to evaluate the expression of hsa-miR-205ab and hsa-miR-218a microRNAs and BRCA1 protein in breast cancer samples and their associations with the pathological and prognostic clinical aspects of tumors. Method: A group of 92 breast cancer cases was evaluated for clinical-pathological aspects, five-year survival, expression of BRCA1, hsa-miR-205ab and hsa-miR-218a. BRCA1 expression was assessed by immunohistochemistry and the quantification of the miRNAs by quantitative PCR in real time. The clinical-pathological aspects were compared in relation to the expression of BRCA1, hsa-miR- 205ab and hsa-miR-218a using the Mann-Whitney test. Survival curves were generated by the Kaplan-Meyer method and compared by the long-rank method. Results: The group of tumors comprised 56 cases of non-triple-negative breast carcinomas and 36 tumors with triple-negative phenotype. Hypoexpression of hsa-miR-205ab and hsa-miR-218a was associated with larger tumors (> 2 cm), presence of lymph node metastasis and distant metastasis, the highest histological grade, triple negative phenotype, absence of expression of BRCA1 and lower survival. (P = 0.044), more advanced stages (p = 0.005), lymph node involvement (p = 0.038), presence of distant metastasis (p = 0, 0008) and absence of BRCA1 expression (p = 0.039). Conclusion: The hypoexpression of hsa-miR-205ab and hsa-miR-218a was associated with factors of poor prognosis, absence of BRCA1 expression and the lowest survival rate in breast cancer patients evaluated in this study. / Introdução: Os microRNAs são pequenas moléculas de RNAs não-codificantes de cadeia simples, que regulam a expressão gênica na fase pós-transcricional e vem sendo avaliados como marcadores prognósticos e preditivos no câncer de mama. Objetivo: O objetivo deste estudo foi avaliar a expressão dos microRNAs hsa-miR-205ab e hsa-miR-218a e da proteína BRCA1 em amostras de câncer de mama e suas associações com os aspectos clínico patológicos e prognósticos dos tumores. Método: Um grupo de 92 casos de câncer de mama foi avaliado quanto aos aspectos clínico-patológicos, a sobrevida em cinco anos, a expressão de BRCA1, hsa-miR-205ab e hsa-miR-218a. A expressão de BRCA1 foi avaliada por imuno- histoquímica e a quantificação dos miRNAs por PCR quantitativa em tempo real. Os aspectos clínicos-patológicos foram comparados em relação à expressão de BRCA1, hsa-miR-205ab e hsa-miR-218a, utilizando o teste de Mann-Whitney. As curvas de sobrevida foram geradas pelo método de Kaplan-Meyer e comparadas pelo método de long-rank. Resultados: O grupo de tumores compreendeu 56 casos de carcinomas de mama não triplo-negativos e 36 tumores com fenótipo triplo-negativo. A hipoexpressão de hsa-miR-205ab e hsa-miR-218a foi associada aos tumores maiores (> 2 cm), à presença de metástase linfonodal e de metástase a distância, ao grau histológico mais elevado, fenótipo triplo negativo, ausência de expressão de BRCA1 e menor sobrevida. A sobrevida das pacientes em função das características clínico patológicas foi influenciada pelo fenótipo triplo-negativo (p=0,044), estádios mais avançados (p=0,005), acometimento linfonodal (p=0,038), presença de metástase à distância (p=0,0008) e ausência da expressão de BRCA1 (p=0,039). Conclusão: A hipoexpressão de hsa-miR-205ab e hsa-miR-218a foi associada aos fatores de pior prognóstico, ausência de expressão de BRCA1 e à menor sobrevida nas pacientes com câncer de mama avaliadas neste estudo.

Este trabalho trata do estudo de complexos de rutênio contendo antiinflamatórios não-esteróides, com o objetivo de contribuir para ampliar as pesquisas na área de potenciais metalofármacos antitumorais. A partir de reações do precursor dimetálico [Ru2(O2CCH3)4Cl] com os fármacos carboxílicos sulindaco (HSulin) e diclofenaco de sódio (NaDiclofen) foram isolados, respectivamente, os correspondentes complexos [Ru2(Sulin)4Cl] e [Ru2(Diclofen)4Cl]. A reação entre o monômero [RuCl2(dmso)4] e o meloxicam (H2Melox) deu origem ao derivado misto [Ru(dmso)2(HMelox)2]. Os compostos foram caracterizados por meio de análise elementar, medidas de condutância molar, medidas de susceptibilidade magnética, espectroscopia de absorção eletrônica UV-VIS-IR, espectroscopia vibracional FTIR e Raman, e estudos de análise térmica (TG/DSC/MS). As interações da albumina de soro humana HSA, importante proteína do plasma, com os complexos obtidos, com o análogo [Ru2(IBP)4Cl] (HIBP = ibuprofeno) e também com os fármacos orgânicos não-complexados foram investigadas empregando-se dicroísmo circular, SDS-Page e fluorescência. A atividade antitumoral dos metalofármacos foi avaliada, através de ensaios com MTT, com base nos seus efeitos citotóxicos para a linhagem celular de leucemia humana K562. / This work describes the study of ruthenium complexes containing non-steroidal antiinflammatory drugs with the aim of helping to expand the research in the field of potential anticancer metallodrugs. Reactions of the [Ru2(O2CCH3)4Cl] dimetal complex with sulindac (HSulin) and sodium diclofenac (NaDiclofen) carboxylic drugs gave the correspondent complexes [Ru2(Sulin)4Cl] and [Ru2(Diclofen)4Cl], respectively. The reaction between the [RuCl2(dmso)4] monomer and the meloxicam drug (H2Melox) led to the mixed derivative [Ru(dmso)2(HMelox)2]. The compounds were characterized by elemental analysis, molar conductance measurements, magnetic susceptibility, UV-VIS-IR electronic absorption spectroscopy, Raman and FTIR vibrational spectroscopies and by studies of thermal analysis (TG / DSC / MS). The interactions of human serum albumin (HSA), the major plasma protein, with the obtained complexes, the analogous [Ru2(IBP)4Cl] (= HIBP ibuprofen) and also with the noncoordinated organic drugs have been investigated by circular dichroism, SDS-Page and fluorescence. The antitumor activity of the metallodrugs has been evaluated by MTT assays, on the basis of their cytotoxic effects on K562 human leukemia cell line.

Neste trabalho uma classe de carboxilatos trinucleares de rutênio coordenados a ligantes ortometalados foi apresentada. As propriedades eletrônicas, eletroquímicas e fotofísicas destes complexos foram investigadas, bem como a atividade anticâncer e interações com biomoléculas alvo, DNA e HSA. Foram realizadas as sínteses e caracterização dos ligantes (L2) C18H10N4, (L3) C19H12N4, (L4) C18H9ClN4, dos precursores (1) [Ru3O(OAc)6(CH3OH)3]CH3COO, (2) [Ru3O(OAc)6(CO)(CH3OH)2], (3) [Ru3O(OAc)6(CO)(py)2], (4) [Ru3O(OAc)6(H2O)(py)2]PF6 e dos novos complexos (1-5), [Ru3O(OAc)5(py)2(L)]PF6, (onde py = piridina, L1 = dppn, L2 = dppz, L3 = dppzCH3, L4 = dppzCl, L5 = phen). Os dados de RMN mostraram que a ortometalação dos ligantes fenazínicos afeta a estrutura dos complexos, com severo abaixamento de simetria. Já a investigação das propriedades eletrônicas e eletroquímicas indicaram que a presença de diferentes substituintes e a basicidade dos ligantes ortometalados influenciaram pouco as propriedades da unidade [Ru3O]+. Em termos da estrutura eletrônica dos complexos, este efeito indica que não há interações de natureza significativas entre os orbitais da unidade [Ru3O]+ e dos ligantes ortometalados. Esse fato pode se originar na falta de planaridade entre a unidade [Ru3O]+ e os ligantes fenazínicos. Os resultados de citotoxicidade em linhagem de célula tumoral (B16F10) e não tumoral (L929) mostraram que os complexos apresentam efeito citotóxico maior contra as células tumorais do que os ligantes livres, bem como baixa citotoxicidade contra a célula não tumoral. Estes resultados mostraram que a série com ligantes ortometalados traz os exemplos com os melhores desempenhos já observados em nosso grupo de pesquisa, em comparação com outros clusters com ponte -oxo, frente ao câncer de melanoma. Os estudos de interação com biomoléculas alvo mostraram que os complexos interagem com o DNA e a HSA. Com o DNA observou-se interações de natureza eletrostática, com contribuição do mecanismo de intercalação à medida que o tamanho e a extensão da conjugação dos ligantes ortometalados aumentam, sendo que o processo de intercalação é favorecido no caso do complexo (1) com o ligante dppn. Foram realizados estudos de interação dos complexos (1-5) com a HSA. Constataram-se valores altos das constantes de ligação complexos-HSA (da ordem 109 M-1) e alterações na estrutura secundária da proteína. Os parâmetros termodinâmicos de interação com o DNA e HSA indicaram que as interações clusters-biomoléculas também apresentam contribuições de caráter hidrofóbico / In this work a class of trinuclear ruthenium carboxylates coordinated to ortho-metallated ligands was presented. The electronic, electrochemical and photophysical properties of these complexes were investigated, as well as anticancer activity and interactions with target biomolecules, DNA and HSA. Synthesis and characterization of ligands (L2) C18H10N4, (L3) C19H12N4, (L4) C18H9ClN4, precursors (1) [Ru3O(OAc)6(CH3OH)3]CH3COO, (2) [Ru3O(OAc)6(CO)(CH3OH)2], (3) [Ru3O(OAc)6(CO)(py)2], (4) [Ru3O(OAc)6(py)2(CH3OH)]PF6 and the complexes (1-5), [Ru3O(OAc)5(py)2(L)] PF6, (where py = pyridine, L1 = dppn, L2 = dppz, L3 = dppzCH3, L4 = dppzCl, L5 = phen). NMR data showed that the ortho-metallation of phenazine ligands affects the structure of the complexes, with severe symmetry lowering. On the other hand, the investigation of the electronic and electrochemical properties indicated that presence of different substituents and the basicity of the ortho-metallated ligands influence little the properties of the unit [Ru3O]+. In terms of the electronic structure of the complexes, this effect indicates that there are no significant -type interactions between the orbitals of the [Ru3O]+ unit and ortometalated ligands. This fact may arise from the lack of planarity between the [Ru3O]+ unit and the phenazine ligands. The results of cytotoxicity in tumor cell and non-tumor cell lines showed that the complexes have a greater cytotoxic effect against tumor cells than free ligands, as well as low cytotoxicity against the non-tumor cell. These results have shown that the series with ortometal ligands brings the best performing examples already observed in our research group, compared to other trinuclear acetates of ruthenium with -oxo bridge, against melanoma cancer. The interaction studies with target biomolecules showed that the complexes interact with DNA and HSA. With the DNA, we observed interactions of an electrostatic nature, with contribution of the intercalation mechanism as the size and extent of conjugation of the orthomolected ligands increases, and the intercalation process is favored in the case of complex (1) with the dppn binder. Interaction studies of the complexes (1-5) with the HSA were performed. High complex-protein association constants (of the order 109 M-1) and alterations in the secondary structure were observed in the presence of the complexes (1-5). The thermodynamic parameters of interaction with DNA and HSA indicated that the clusters-biomolecules interactions also present hydrophobic contributions

L’avènement de la microscopie biphotonique et des techniques dites de « super-résolution » ont permis d’améliorer les performances de la microscopie de fluorescence et de l’appliquer à l’imagerie intravitale et à l’analyse des tissus biologiques. Ces techniques requièrent néanmoins l’emploi de sondes aux propriétés optiques et biologiques optimisées.Plusieurs séries de colorants cationiques basés sur le motif vinyl-triphénylamine (TP) ont été développés pour le marquage d’ADN. Ces fluorophores rouges ou jaunes dont l’émission de fluorescence est commutée par l’interaction avec l’ADN sont des ligands de petit sillon de l’hélice B et possèdent des sections efficaces d’absorption à deux photons élevées.Les TP marquent l’ADN du noyau des cellules fixées ou en apoptose avec une intensité et un contraste élevés. Elles sont non-cytotoxiques, photostables et sont perméables à la membrane cellulaire. L’optimisation des propriétés a permis d’obtenir la TP-2Bzim, qui possède une brillance biphotonique parmi les plus élevées rapportées dans la littérature pour des molécules de faible poids moléculaire (383 GM) et permet une détection en microscopie biphotonique à basse concentration et à faible puissance d’excitation. En cellules vivantes, les TP sont localisées dans les mitochondries mais, sous excitation mono- ou bi-photonique constante, elles déclenchent l’apoptose de la cellule et se relocalisent dans le noyau. Le phénomène peut être imagé par fluorescence, et les TP pourraient donc être employées comme photosensibilisateurs théranostiques.Enfin, une stratégie de synthèse pour fonctionnaliser la TP-2Bzim a été développée. Elle a ainsi pu être couplée à des oligonucléotides et à un PNA pour la détection d’hybridation par fluorescence et à l’acide folique et à la spermidine pour le ciblage de cellules cancéreuses. / Significant advances were made in the field of in vivo fluorescence imaging thanks to the recent development of biphotonic microscopy and super-resolution techniques, rendering intravital imaging and biological tissues analysis possible. Those techniques however require the use of new probes with optimized optical and biological properties.Several series of cationic dyes for DNA staining were developed based on the vinyl-triphenylamine (TP) scaffold. Those new switchable yellow or red fluorophores bind in the minor-groove of DNA and display high two-photon absorption cross-sections. Two anionic derivatives were also designed for staining HSA.In fixed or apoptotic cells, the cationic dyes stain nuclear DNA with a high brightness and contrast. They are non-cytotoxic, photostable and cell permeant. The molecule with the most optimized properties, TP-2Bzim, has one of the highest two-photon brightness to date (383 GM in DNA), allowing sensible detection in biphotonic microscopy at low concentration and excitation power. In live cells, the dyes are localized in the mitochondria, but it appears that upon constant mono- or bi-photonic excitation they trigger cell apoptosis within a few minutes and are released in the nucleus. Since the phenomenon can be imaged by fluorescence microscopy, the TP dyes could thus be used as photosensitizers for theranostics.A synthetic pathway was also developed to functionalize the TP-2Bzim. It was then coupled by “click-chemistry” to short oligonucleotides or PNA sequences for fluorescence in situ hybridization, and to folic acid and spermidine for cancer cells targeting.

L’objectif de cette thèse est d’étudier expérimentalement les deformations de microcapsules dans un écoulement confiné. Les microcapsules sont composées d’albumine du sérum humain avec des concentrations de 5 à 20 [g/100mL]. Leur taille varie de 50 à 1000 [μm]. Les capsules sont injectées dans des écoulements de Poiseuille produits dans des canaux microfluidiques présentant deux sections différentes : circulaire ou carrée.La mesure des caractéristiques géométriques de microcapsules déformées couplée à des simulations numériques mène à la détermination du module de cisaillement surfacique. Cette caractéristique mécanique augmente fortement tant avec la taille qu’avec la concentration en protéine de la capsule, et plus précisément avec le produit de ces deux paramètres.Le fluide est ensemencé avec des microparticules pour mesurer l’écoulement induit par une capsule dans un capillaire cylindrique par la méthode de la vélocimétrie par suivi de particules. Les zones de recirculation et de perturbation sont alors déduites et comparées avec la simulation numérique d’un objet rigide dans un capillaire et présentant le profil donné par les expériences. Finalement un système original de visualisation optique est consacré à l’observation simultanée de la vue de côté et de la vue de face des capsules pour obtenir sa forme entière. Ceux-ci révèlent l’existence des plis tout autour de la membrane des capsules. Le seuil de formation et l’évolution de ces plis sont étudiés en fonction de la vitesse, de la taille et du confinement, dans des canaux de section circulaire ou carrée. / The objective of this thesis is to study experimentally microcapsule deformations in confined flows. The microcapsules are made of cross-linked proteins, the human serum albumin (HSA) with concentrations from 5 to 20 [g/100mL]. Their size vary from 50 to 1000 [μm]. Capsules are injected in Poiseuille flows generated within microfluidics channels with two different cross sections geometries : circular or square.The measurement of geometrical characteristics of deformed microcapsules coupled with numerical simulations leads to the determination of the surface shear modulus. This mechanical characteristic increases strongly with both the size and the protein concentration of the capsule, and more precisely with the product of these two parameters.The flow is seeded with microparticles to measure the induced flow of a capsule in a cylindrical capillary by particle tracking velocimetry. The recirculation and perturbation zones are then deduced and compared with numerical simulation of a rigid body flowing in a capillary. Finally an original system of optical visualization is dedicated to the simultaneous observation of the side and the front view of the capsules to get its whole shape. These reveal radial wrinkles all around capsules membrane. The formation threshold and the evolution of these wrinkles are studied as function of the capsule velocity and size and the confinement within capillaries with circular or square cross–section.