MAIA, José Robson. Estudo do L-histidinato de niquel (II) monohidratado sob condições extremas de temperatura e pressão por Espectroscopia Raman. 2014. 106 f. Tese (Doutorado em Física) - Programa de Pós-Graduação em Física, Departamento de Física, Centro de Ciências, Universidade Federal do Ceará, Fortaleza, 2014. / Submitted by Edvander Pires (edvanderpires@gmail.com) on 2014-10-31T20:27:09Z No. of bitstreams: 1 2014_tese_jrmaia.pdf: 4019401 bytes, checksum: 420b482ed2b28ebe5d6b391e56123ee8 (MD5) / Approved for entry into archive by Edvander Pires(edvanderpires@gmail.com) on 2014-10-31T21:08:22Z (GMT) No. of bitstreams: 1 2014_tese_jrmaia.pdf: 4019401 bytes, checksum: 420b482ed2b28ebe5d6b391e56123ee8 (MD5) / Made available in DSpace on 2014-10-31T21:08:22Z (GMT). No. of bitstreams: 1 2014_tese_jrmaia.pdf: 4019401 bytes, checksum: 420b482ed2b28ebe5d6b391e56123ee8 (MD5) Previous issue date: 2014 / In this work bis(L-histidinato)nikel(II) Monohydrate crystals were obtained by slow evaporation method using 1 mol of NiCl2.6H2O, 2 mols of L-histidine and NaOH. Reitveld refinement of X-ray data confirmed the structure. Raman modes obtained at ambient conditions of pressure and temperature were assigned by comparison with results on similar materials and by density functional theory DFT calculations. PED (potential energy distribution) is also present. Raman spectroscopy measurements were performed from room temperature up to 150 oC in the 50- 3500 cm-1 spectral range. For temperatures higher than 125 oC the modes related with the water stretching disappeared as well as the lattice modes disappeared indicating a phase transition undergone by the crystal. DSC experiments support this assumption. By decreasing temperature up to 18 K in the 40-3500 cm-1 spectral range it was observed modifications only in internal modes, so we believe that some conformational change has been occurred in the molecules of bis(L-histidinate)nikel(II) Monohydrate. High pressure experiments were performed from ambient pressure up to 9,5 GPa in the 50-3500 cm-1 spectral range. Disappearance of modes between 0,4 and 0,8 GPa was interpreted as evidences of a structural phase transition undergone by the crystal. A second set of modifications in the spectra indicates other phase transition experienced by the crystal between 2,6 and 3,2 GPa. The spectrum obtained the realizing pressure points out to the irreverbility of the phase transitions. / Neste trabalho cristais de L-histidinato de níquel (II) monohidratado (Ni(C6H8N3O2)2.H2O) foram obtidos por meio da evaporação lenta do solvente de uma solução saturada de 1 mol de NiCl2.6H2O, 2 mols de L-histidina mais NaOH. Após a obtenção da amostra a confirmação da estrutura deu-se por refinamento do Reitveld. A classificação dos modos vibracionais à temperatura e pressão ambiente foi realizada por comparação com outros materiais e através de cálculos de teoria da densidade do funcional DFT. A distribuição da energia potencial (PED) também foi calculada. Experimentos de espectroscopia Raman variando a temperatura desde a temperatura ambiente até 150 0C, foram realizadas no cristal de L-histidinato de níquel (II) monohidratado no intervalo espectral entre 50 e 3500 cm-1. Para temperaturas superiores a 125 0C o desaparecimento e surgimento de modos na região dos modos da rede bem como na região dos modos internos indicam uma transição de fase estrutural no L-histidinato de níquel (II) monohidratado devido à saída de água. A transição é irreversível pois o espectro obtido após a amostra retornar a temperatura ambiente é bem diferente daquele obtido no início do experimento. Experimentos de DSC corroboram com o experimento de espectroscopia Raman pois indicam a saída da molécula de água do cristal de L-histidinato de níquel (II) monohidratado no valor de temperatura de 140 0C, e ainda perda de massa de água na mesma temperatura (140 0C), relatada pela curva de TG. Nos experimentos de espectroscopia Raman a baixas temperaturas a amostra de L-histidinato de níquel (II) monohidratado foi resfriada desde a temperatura ambiente até 18 K no intervalo espectral de 40 a 3500 cm-1. Observou-se o surgimento de alguns modos internos, porém, como não evidenciou-se mudanças nos modos externos supomos que o material deva sofrer apenas uma mudança conformacional. Os experimentos de espectroscopia Raman a altas pressões foram realizados no intervalo de pressão entre 0,1 e 9,5 GPa, em um intervalo espectral de 50 a 3500 cm-1. Com o aumento da pressão percebe-se o desaparecimento de modos indicando uma transição de fase estrutural entre 0,4 e 0,8 GPa. Aumentando-se ainda mais a pressão observa-se o surgimento de três modos em torno da frequência de 50 cm-1 no intervalo de pressão entre 2,6 e 3,2 GPa. Estas mudanças indicam uma segunda transição de fase estrutural da amostra de L-histidinato de níquel (II) monohidratado. O espectro obtido após a descompressão é idêntico aquele do início do experimento indicando reversibilidade da transição.

RÊGO, Fellipe dos Santos Campêlo. Medidas de Espectroscopia Raman em cristais de DL-Valina a altas pressões. 2015. 72 f. Dissertação (Mestrado em Física) - Programa de Pós-Graduação em Física, Departamento de Física, Centro de Ciências, Universidade Federal do Ceará, Fortaleza, 2015. / Submitted by Edvander Pires (edvanderpires@gmail.com) on 2015-04-16T18:32:26Z No. of bitstreams: 1 2015_dis_fscrego.pdf: 15205692 bytes, checksum: d8dfd928800e9bd0e7d450a8ae193269 (MD5) / Approved for entry into archive by Edvander Pires(edvanderpires@gmail.com) on 2015-04-16T18:33:40Z (GMT) No. of bitstreams: 1 2015_dis_fscrego.pdf: 15205692 bytes, checksum: d8dfd928800e9bd0e7d450a8ae193269 (MD5) / Made available in DSpace on 2015-04-16T18:33:40Z (GMT). No. of bitstreams: 1 2015_dis_fscrego.pdf: 15205692 bytes, checksum: d8dfd928800e9bd0e7d450a8ae193269 (MD5) Previous issue date: 2015 / In this work, we present a study of the Raman scattering of DL-valine crystals (C5H11NO2) at room temperature under high hydrostatic pressures conditions using the spectral range of 40-3200 cm-1. Based on previous studies using Raman spectroscopy on crystals of DL-valine and other amino acids such as L-valine, L-isoleucine and L- asparagine, we proposed the classification of the bands in different vibration modes. The Raman spectrum obtained as function of pressure suggests that DL-valine suffered two structural phase transitions by 19,4 GPa. The first transition phase of between 1,4 GPa and 1,8 GPa where we observed the disappearance of three modes, one network mode and two internal modes classified as rocking of NH3+ and symmetric stretching of CH3, vs (CH3). The second phase transition of between 7,8 GPa and 8,8 GPa, where we observe the unfolding of a network mode, the disappearance of the internal mode associated with skeletal deformation, d(esk) and the splitting designated as CH2, v(CH2). / Neste trabalho, apresentamos um estudo de espalhamento Raman em cristais de DL-valina (C5H11NO2) à temperatura ambiente e sob condições de altas pressões hidrostáticas, no intervalo espectral de 40 cm-1 a 3200 cm-1. Baseando-se em estudos anteriores sobre espectroscopia Raman em cristais de DL-valina e de outros aminoácidos, tais como, L-valina, L-isoleucina e L-asparagina, propusemos uma classificação das bandas em diversos modos de vibração. Os espectros obtidos, por espectroscopia Raman, em função da pressão sugerem que a DL-valina sofreu duas transições de fase estruturais até 19,4 GPa. A primeira transição de fase entre 1,4 GPa e 1,8 GPa onde foi observado o desaparecimento de três modos, um modo de rede e dois modos internos classificados como rocking do NH3+, r(NH3+), e estiramento simétrico do CH3, vs (CH3). A segunda transição de fase entre 7,8 GPa e 8,8 GPa, onde foi observado o desdobramento de um modo de rede, o desaparecimento de um modo interno associado a uma deformação do esqueleto da molécula, d(esq) e a divisão de um modo designado como estiramento do CH2, v(CH2).

BARBOZA, Felipe Moreira. Espectroscopia Raman na L-valina deuterada a baixas temperaturas. 2012. 75 f. Dissertação (Mestrado em Física) - Programa de Pós-Graduação em Física, Departamento de Física, Centro de Ciências, Universidade Federal do Ceará, Fortaleza, 2012. / Submitted by Edvander Pires (edvanderpires@gmail.com) on 2015-04-23T21:25:11Z No. of bitstreams: 1 2012_dis_fmbarboza.pdf: 1400454 bytes, checksum: d614be224b439b279076ca7546ca4c23 (MD5) / Approved for entry into archive by Edvander Pires(edvanderpires@gmail.com) on 2015-04-29T17:45:05Z (GMT) No. of bitstreams: 1 2012_dis_fmbarboza.pdf: 1400454 bytes, checksum: d614be224b439b279076ca7546ca4c23 (MD5) / Made available in DSpace on 2015-04-29T17:45:05Z (GMT). No. of bitstreams: 1 2012_dis_fmbarboza.pdf: 1400454 bytes, checksum: d614be224b439b279076ca7546ca4c23 (MD5) Previous issue date: 2012 / Deuteration allows the identification of several species of vibrations, through the comparison of vibrational spectra of the deutered and hydrogeneted samples. In this work we base studied the vibrational properties of L-valine-d8 (99,8 % atom % D) through the Raman spectroscopy technique. At first, the assignment of all Raman active vibratonal mades of L-valine was revisited, and a comparison with a previous work was done. In particular, several bands associated to stretching of NH_3^+ and stretching of CH3, among others, which are observed in the interval 2000 – 2400 cm-1 were assigned. In the second part of the work, again using Raman spectroscopy, it was studied the vibrational modes of the crystal in the temperature range 100 – 300 K. It is known from literature that hydrogenated L-valine undergoes a phase transition at about 110 K. It also known that in deuterated crystals hydrogen bands - through Ubbehlode effect – tend to be less strange and, as a consequence, a comparative analyses between the deuterated and hydrogenated samples is very important. In a previous work on L-alanine it was observed that deutaration induces a new phase at low temperatures. In the investigation on L-valine, at least in the temperature range studied, it was not possible to note any change in the Raman spectra which could be associated to a structural phase transition. Both in the external modes region any great change is verified. As a consequence, we can infer that L-valine-d8 is stable between 100 and 300 K. A discussion about the difference behaviors at low temperatures of L-valine and L-alanine (both deuterated and hydrogenated) is also furnished in the present work. / A deuteração de uma determinada amostra permite fazer a identificação de vários tipos de vibrações, comparando-se o espectro vibracional com o de uma amostra hidrogenada. Neste trabalho estudou-se o comportamento vibracional da L-valina-d8 (99,8 átomo % D) através da técnica de espectroscopia Raman. Inicialmente revisitou-se o assinalamento de todos os modos vibracionais ativos no Raman, comparando-se com um estudo previamente realizado. Em particular foram identificadas diversas bandas associadas a vibrações do tipo estiramento do NH3+ e estiramento do CH3, entre outros, que são observadas na região entre 2000 e 2400 cm-1. Na segunda parte do trabalho foi realizado um estudo via espalhamento Raman dos modos vibracionais do cristal no intervalo de temperatura entre 100 e 300 K. Sabe-se da literatura que a L-valina hidrogenada apresenta uma transição de fase em torno de 110 K. Uma vez que nos cristais deuterados as ligações de hidrogênio via o efeito Uhbehlode tendem a ser mais fracas, uma análise comparativa entre as amostras hidrogenada e deuterada se faz necessário. Em particular, num estudo realizado na L-alanina descobriu-se que a deuteração induz a formação de uma nova fase em baixas temperaturas. No caso da L-valina, pelo menos no intervalo de temperatura investigado, não foi possível observar nenhuma mudança nos espectros Raman que pudessem ser associadas a uma transição de fase estrutural. De fato, tanto na região dos modos externos, quanto na região dos modos internos nenhuma grande modificação é verificada. Isso implica que a estrutura da L-valina-d8 é estável no intervalo de 100-300 K. Uma discussão acerca da diferença do comportamento a baixas temperaturas dos cristais de L-valina e de L-alanina nas formas hidrogenadas e deuteradas é também fornecida no presente trabalho.

ABAGARO, Bruno Tavares de Oliveira. Propriedades vibracionais de cristais de DL-leucina e L-prolina monohidratada submetidos a altas pressões. 2012. 116 f. Tese (Doutorado em Física) - Programa de Pós-Graduação em Física, Departamento de Física, Centro de Ciências, Universidade Federal do Ceará, Fortaleza, 2012. / Submitted by Edvander Pires (edvanderpires@gmail.com) on 2015-05-20T18:43:46Z No. of bitstreams: 1 2012_tese_btoabagaro.pdf: 5633012 bytes, checksum: 021da558210c7a87a4904feee0d9a2b0 (MD5) / Approved for entry into archive by Edvander Pires(edvanderpires@gmail.com) on 2015-05-22T20:06:05Z (GMT) No. of bitstreams: 1 2012_tese_btoabagaro.pdf: 5633012 bytes, checksum: 021da558210c7a87a4904feee0d9a2b0 (MD5) / Made available in DSpace on 2015-05-22T20:06:05Z (GMT). No. of bitstreams: 1 2012_tese_btoabagaro.pdf: 5633012 bytes, checksum: 021da558210c7a87a4904feee0d9a2b0 (MD5) Previous issue date: 2012 / We studied the stability of two types amino acid crystal: a racemic crystal, DL-leucine (C6H13NO2); and a chiral one; L-proline monohydrate (C5H9NO2.H2O). Both were subjected to high pressures. The structural properties at ambient conditions (with the hydrogen-bonds data) of each crystal type were presented. For the DL-leucine crystal, polarized Raman scattering measurements were made in three different scattering geometries. The classification of the normal modes of vibration was made in terms of representations of irreducible factors groups Ci (for the crystal of DL-leucine) and C2 (crystal of L-proline monohydrate). Based on studies already carried out previously, tentative assignments were proposed for the Raman bands observed for the two crystals. The high pressure Raman experiments were performed in a diamond anvil cell using mineral oil as pressure media. For the DL-leucine crystal, the maximum pressure was studied up to about 5 GPa. Among the various observed effects, we found the discontinuity of the wavenumber versus pressure curves between 2.4 and 3.2 GPa, both for the region of the external modes as for region of internal modes, particularly remarkable. These effects were interpreted as resulting from a gradual change of the molecular conformation of leucine molecules in the unit cell, culminating with change of hydrogen bonds in the interval where the phase transition is observed. This behaviour suggests that the DL-leucine crystal is more stable than the chiral L-leucine in the sense that while the former presents only one phase transition, the latter presents at least two different transitions in the same pressure range considered. For the L-proline monohydrated crystal, which was subject to pressures up to about 8.0 GPa, several induced effects by this thermodynamic parameter were observed in the Raman spectra, such as the appearance and disappearance of bands, discontinuities in the wavenumber versus pressure curves in the regions of external and internal modes and intensity relative changes. These changes point to the fact that between (i) 1.1 e 1.7 GPa and (ii) 4.5 e 5.0 GPa, this hydrated crystal undergoes phase transitions accompanied by conformational molecular changes in the unit cell. / Neste trabalho, estudou-se a estabilidade de dois tipos de cristais de aminoácidos: um cristal racêmico; DL-leucina (C6H13NO2) e um quiral; L-prolina monohidratada (C5H9NO2.H2O), ambos submetidos a altas pressões. As propriedades estruturais em condições ambientes (com dados sobre as ligações de hidrogênio) de cada tipo de cristal foram apresentadas. Para o cristal de DL-leucina foram feitas medidas de espectrosocopia Raman polarizada em três diferentes geometrias de espalhamento. A distribuição dos modos normais de vibração foi feita em termos das representações irredutíveis dos grupos fatores Ci (para o cristal de DL-leucina) e C2 (cristal de L-prolina monohidratada). Foram propostas classificações tentativas para as bandas Raman observadas para os dois cristais, tendo como base estudos já realizados anteriormente. Os experimentos de espalhamento Raman sob altas pressões foram realizados em uma câmara de bigornas de diamantes utilizando-se óleo mineral como meio compressor. No caso do cristal de DL-leucina, a pressão máxima estudada foi de, aproximadamente, 5 GPa. Entre os diversos efeitos observados, destaca-se a descontinuidade das curvas de número de onda versus pressão entre 2,4 e 3,2 GPa, tanto para a região dos modos externos quanto para a região dos modos internos. Os efeitos foram interpretados como sendo decorrentes de uma mudança gradual de conformação das moléculas de leucina na célula unitária do cristal, culminando em uma mudança nas ligações de hidrogênio no intervalo onde a transição de fase foi observada. Esse comportamento sugere que o cristal de DL-leucina é mais estável sob altas pressões que o seu correspondente quiral, considerando que o cristal de L-leucina, o qual apresentou pelo menos duas transições de fase no mesmo intervalo de pressão considerado. Em relação ao cristal de L-prolina monohidratada, submetido a pressões de até cerca de 8,0 GPa, diversos efeitos induzidos por esse parâmetro termodinâmico nos espectros Raman foram observados, como o surgimento e desaparecimento de bandas,descontinuidades nas curvas de número de onda versus pressão nas regiões dos modos externos e internos, bem como mudanças de intensidade relativa. Essas modificações sugerem que entre (i) 1,1 e 1,7 GPa e (ii) 4,5 e 5,0 GPa, esse cristal hidratado sofre transições de fase acompanhadas por mudanças conformacionais das moléculas na célula unitária.

No description available.

This thesis presents work based on the interactions of water soluble caboxylated zinc phthalocyanines (Pcs) and coreshell quantum dots (QDs). The Pcs are ZnPc(COOH)₈ and ZnPc(COOH)₄ and coreshell QDs are CdTe@ZnS-GSH. GSH = L-glutathione. Characterization and photophysical studies of conjugates were carried out. The approach of coordinating Pcs to QDs was achieved using an organic cross linker, N-N’-dicyclohexylcarbodiimide (DCC) at pH 10 at room temperature. Employing atomic force microscopy (AFM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman, infrared and X-ray photoelectron spectroscopies, the formation of the conjugates was confirmed. Upon conjugation with Pc derivatives, the fluorescence quantum yield of CdTe@ZnS-GSH decreased due to energy transfer from the QDs to the Pc. The average fluorescence lifetime of the CdTe@ZnS-GSH QD also decreased upon conjugation. The föster resonance energy transfer (FRET) behaviour of CdTe@ZnS-GSH-ZnPc(COOH)₄ conjugates was compared to that of CdTe@ZnS-GSH-ZnPc(COOH)₈. Higher FRET efficiencies were observed for CdTe@ZnS-GSH-ZnPc(COOH)₄-mixed or CdTe@ZnS-GSH-ZnPc(COOH)₄-linked compared to the corresponding CdTe@ZnS-GSH-ZnPc(COOH)₈-mixed or CdTe@ZnS-GSH-ZnPc(COOH)₈-linked. Triplet quantum yield (ΦT) and lifetime (ΤT) of ZnPc(COOH)₈ were found to increase in the presence of coreshell QDs. Though the singlet quantum yield (ΦΔ) value of ZnPc(COOH)8 was lower than ΦT , there was a slight upsurge in the ΦT in the presence of QDs. / Microsoft� Word 2010 / Adobe Acrobat 9.53 Paper Capture Plug-in

abstract: The search for life on Mars is a major NASA priority. A Mars Sample Return (MSR) mission, Mars 2020, will be NASA's next step towards this goal, carrying an instrument suite that can identify samples containing potential biosignatures. Those samples will be later returned to Earth for detailed analysis. This dissertation is intended to inform strategies for fossil biosignature detection in Mars analog samples targeted for their high biosignature preservation potential (BPP) using in situ rover-based instruments. In chapter 2, I assessed the diagenesis and BPP of one relevant analog habitable Martian environment: a playa evaporite sequence within the Verde Formation, Arizona. Coupling outcrop-scale observations with laboratory analyses, results revealed four diagenetic pathways, each with distinct impacts on BPP. When MSR occurs, the sample mass returned will be restricted, highlighting the importance of developing instruments that can select the most promising samples for MSR. Raman spectroscopy is one favored technique for this purpose. Three Raman instruments will be sent onboard two upcoming Mars rover missions for the first time. In chapters 3-4, I investigated the challenges of Raman to identify samples for MSR. I examined two Raman systems, each optimized in a different way to mitigate a major problem commonly suffered by Raman instruments: background fluorescence. In Chapter 3, I focused on visible laser excitation wavelength (532 nm) gated (or time-resolved Raman, TRR) spectroscopy. Results showed occasional improvement over conventional Raman for mitigating fluorescence in samples. It was hypothesized that results were wavelength-dependent and that greater fluorescence reduction was possible with UV laser excitation. In Chapter 4, I tested this hypothesis with a time-resolved UV (266 nm) gated Raman and UV fluorescence spectroscopy capability. I acquired Raman and fluorescence data sets on samples and showed that the UV system enabled identifications of minerals and biosignatures in samples with high confidence. The results obtained in this dissertation may inform approaches for MSR by: (1) refining models for biosignature preservation in habitable Mars environments; (2) improving sample selection and caching strategies, which may increase the success of Earth-based biogenicity studies; and (3) informing the development of Raman instruments for upcoming rover-based missions. / Dissertation/Thesis / Doctoral Dissertation Geological Sciences 2016

The major aim of this thesis is critical evaluation of Raman spectroscopy in the detection of carotenoids of extremophiles, namely snow algae. Extremophilic microorganisms play an important role in exobiology since they set hypothetical boundaries for the presence of life on Earth. Raman spectroscopy will be a part of two mission to Mars. Here, a laboratory Raman microspectrometer was used for the analysis of 11 samples of snow algae from different locations over the years 2002-2017. The acquired spectra were compared with HPLC/UV-VIS analysis. The results showed that the ability of Raman spectroscopy to discriminate between structurally slightly differing carotenoid pigments or several carotenoids in an admixture is limited. Contrary, HPLC/UV-VIS permitted to detect various structurally similar carotenoids (and chlorophylls). However, HPLC/UV-VIS worked with overall pigment extracts during which some structural information can be lost. Raman microspectrometer allowed analysis of cells in different life-cycle stages and thus several various spectra could be studied. Raman microspectrometer was therefore more suitable for carotenoid detection in mixtures of various life-stages than HPLC/UV-VIS. Key words carotenoids, snow algae, exobiology, habitability, biomarker, Raman spectroscopy, HPLC/UV-VIS

Submitted by Claudinei Pracidelli (cpracide@ipen.br) on 2015-11-12T10:30:34Z No. of bitstreams: 0 / Made available in DSpace on 2015-11-12T10:30:34Z (GMT). No. of bitstreams: 0 / Dissertação (Mestrado em Tecnologia Nuclear) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

L’ostéogénèse imparfaite(OI) est une maladie génétique rare qui se caractérise, entre autres, par une fragilité accrue des os. Des analyses du génome des patients atteints ont permis d’identifier les mutations qui déclenchaient ce principal symptôme. Pour le tissu osseux, la difficulté dans la compréhension de cette pathologie réside dans la structure multi-échelle du tissu osseux et dans son caractère de tissu vivant renouvelé par le remodelage osseux.Dans cette thèse, nous avons donc dans un premier temps étudié l’impact des différentes mutations sur la structure nanoscopique du tissu osseux de patients OI. Pour ce faire, une technique d’exploration des propriétés physico-chimiques a été développée. Plus particulièrement, nous avons pu mesurer l’apport de la spectroscopie Raman à l’étude du tissu osseux. Cela a permis d’identifier différentes conséquences sur le tissu osseux créées par des mutations touchant des protéines impliquées dans le métabolisme osseux. Ainsi, du point de vue de la spectroscopie Raman, trois groupes de mutations sont dissociables :• les mutations touchant directement le collagène et ses modifications (OI type génétique III, VII et VIII),• les mutations causant l’OI de type VI qui se caractérise par une hyper minéralisation due à une sous production de collagène,• les mutations causant l’OI de type XI qui se caractérise par un taux de substitution en carbonate plus important que la moyenne traduisant un taux de remodelage plus faible.Dans un second temps, l’aspect vivant du tissu osseux a été étudié avec l’étude de la phase de résorption du remodelage osseux. Il a ainsi été montré que les cellules osseuses qui résorbaient la matrice osseuse n’agissaient pas de manière aléatoire, mais qu’elles ciblaient les zones aux propriétés mécaniques et minérales les plus faibles. Ce comportement étudié d’abord sur du tissu osseux adulte sain a été aussi observé sur les os des patients souffrant d’OI. La pathologie n’a pas modifié qualitativement ce comportement. / Osteogenesis imperfecta (OI) is a rare genetic disease, whose main feature is more brittle bone. Genetic analysis identified mutations making the bone more prone to fracture. As the bone is a multistructrural material, while also being a living tissue, the symptoms and consequences of the disease are numerous. During this thesis, the focus was made on a first approach on the differences of nanostructures between the various mutations causing OI. More specifically, a new use of Raman spectroscopy was made in order to study the collagenic matrix as well as the mineral component. It was found that mutations could be gathered in three groups:• Mutations implied directly in the collagen synthesis and in its early modification (OI genetical type III, VII et VIII),• Mutations implied directly in the mineralization of the collagenic matrix, with an hypermineralization of this matrix (OI genetical type VII),• Mutations causing OI genetical type XI, characterized by a high rate of carbonate substitution, implying a low remodeling rate.On the other hand, the living aspect of bone tissue was studied, with a focus made on the resorption phase of the remodeling cycle. It was found on healthy adults bone that the cells were not behaving randomly, but target osteons with lower mechanical and mineral properties. Moreover, the behavior of those cells is not altered by OI: it was found that the cells had the same not-random behavior on bone of OI patients.