Dysregulation of endothelial cell barrier function is associated with a wide variety of human diseases ranging from tumor metastasis to inflammation. The barrier function of endothelial cells is maintained by cell adhesion molecules (CAMs). Immunoglobulin containing and proline-rich receptor-1(IGPR-1) was recently identified as a novel CAM involved in angiogenesis. However, the molecular mechanism of IGPR-1 function in endothelial cells remains largely unknown. The overarching goals of this study were: (A) to determine molecular mechanism by which IGPR-1 stimulates biological responses in cells and (B) to investigate regulation of phosphorylation of IGPR-1 at serine 220 (Ser220), and its role in IGPR-1 function. Our data demonstrate that IGPR-1 undergoes cis-dimerization, which leads to homophilic trans-dimerization of IGPR-1, which is required for its adhesive function. Moreover, we demonstrate that phosphorylation of Ser220 is regulated by trans-dimerization of IGPR-1 and that Glycogen Synthase Kinase 3 (GSK-3) is responsible for its phosphorylation as over-expression of kinase active increased and kinase inactive inhibited phosphorylation of Ser220, respectively. Taken together, the results demonstrate that the coordinated dimerization of IGPR-1 and its homophilic interaction regulates its adhesive function and serine phosphorylation. The adhesive function of IGPR-1 contributes to the barrier function of endothelial cells.

La présente thèse s’inscrit dans un projet collaboratif de type CEFIPRA entre l’Inde (Dr. Ravi Kumar, Department of Metallurgical and Materials Engineering, Indian Institute of Technology-Madras (IIT Madras), Chennai) et la France (Dr. Samuel Bernard, Institut Européen des Membranes, CNRS, Montpellier). Les travaux de thèses se sont consacrés à la synthèse de céramiques de type non-oxyde autour de systèmes binaires (nitrure de silicium et nitrure de bore) et ternaires (Si-M-N, B-M-N (M=Ti, Zr, Hf)) à partir de précurseurs moléculaires et polymères, i.e., la voie polymères précéramiques ou PDCs. L’idée principale de ce travail est de former des structures nanocomposites à partir des systèmes ternaires dans lesquelles des nanocristaux de nitrures métalliques (M=Ti, Zr, Hf) se développent pendant la synthèse du nitrure de silicium et du nitrure de bore. Une caractérisation complète allant des polymères aux matériaux finaux a été conduite. Ces matériaux ont ensuite été préparés sous forme de composés mésoporeux (monolithes) en couplant la voie des polymères précéramiques à une approche de nanomoulage. Ces monolithes à haute surface spécifique et mésoporosité interconnectée ont alors été appliqués comme support de nanoparticules de platine pour l’hydrolyse du borohydrure de sodium pour générer de l’hydrogène. Les performances en tant que support de catalyseur ont été évaluées en termes de volume d’hydrogène libéré et de reproductibilité. Nous avons montré que les nanocomposites TiN/Si3N4 de surface spécifique très élevée présentent les meilleures performances grâce à l’activité catalytique du Si3N4 amorphe, de la présence de TiN nanométrique et de l’effet synergétique entre les nanoparticules Pt, le TiN nanostructuré et le Si3N4 amorphe. En preuve de concept, nous avons montré que ces structures nanocomposites étaient multifonctionnelles: elles peuvent être appliquées en tant que supports d’électro-catalyseurs et matériaux d’électrodes dans les piles à combustibles et les super-condensateurs, en particulier pour ceux contenant des matériaux lamellaires 2D et du carbone libre. / The thesis has been funded by a collaborative research partnership between Indian (Dr. Ravi Kumar, Department of Metallurgical and Materials Engineering, Indian Institute of Technology-Madras (IIT Madras), Chennai) and French institutes (Dr. Samuel Bernard, European Membrane Institute, CNRS, Montpellier), IFCPRA/CEFIPRA. It is focused on the synthesis, and characterization of binary (silicon nitride and boron nitride) and ternary (Si-M-N, B-M-N (M = Ti, Zr, Hf)) ceramics which are prepared through a precursor approach based on the Polymer-Derived Ceramics (PDCs) route. The idea behind the preparation of the ternary systems is to form nanocomposite structures in which metal nitrides (M = Ti, Zr, Hf) nanocrystals grow during the synthesis of silicon nitride and boron nitride. A complete characterization from the polymer to the final material is done. Then, these materials have been prepared as mesoporous monoliths coupling the PDCs route with a nanocasting approach to be applied as supports of platinum nanoparticles for the hydrolysis of liquid hydrogen carriers such as sodium borohydride. The performance as catalyst supports has been evaluated in terms of volume of hydrogen released and reproducibility. We showed that the very high specific surface area TiN/Si3N4 nanocomposites displayed the best performance because of the catalytic activity of amorphous Si3N4, the presence of nanoscaled TiN and the synergetic effect between Pt nanoparticles, nanoscaled TiN and amorphous Si3N4. Interesting, these materials are multi-functional as demonstrated as a proof of concept: they can be applied as electrocatalyst supports, electrode materials for fuel cells and supercapacitors, in particular those containing 2D layered materials and free carbon.

abstract: The bonding and electrostatic properties of gold containing molecules are highly influenced by relativistic effects. To understand this facet on bonding, a series of simple diatomic AuX (X=F, Cl, O and S) molecules, where upon bond formation the Au atom donates or accepts electrons, was investigated and discussed in this thesis. First, the optical field-free, Stark, and Zeeman spectroscopic studies have been performed on AuF and AuCl. The simple polar bonds between Au and typical halogens (i.e. F and Cl) can be well characterized by the electronic structure studies and the permanent electric dipole moments, el. The spectroscopic parameters have been precisely determined for the [17.7]1, [17.8]0+ and X1+ states of AuF, and the [17.07]1, [17.20]0+ and X1+ states of AuCl. The el have been determined for ground and excited states of AuF and AuCl. The results from the hyperfine analysis and Stark measurement support the assignments that the [17.7]1 and [17.8]0+ states of AuF are the components of a 3 state. Similarly, the analysis demonstrated the [19.07]1 and [19.20]0+ states are the components of the 3 state of AuCl. Second, my study focused on AuO and AuS because the bonding between gold and sulfur/oxygen is a key component to numerous established and emerging technologies that have applications as far ranging as medical imaging, catalysis, electronics, and material science. The high-resolution spectra were record and analyzed to obtain the geometric and electronic structural data for the ground and excited states. The electric dipole moment, el, and the magnetic dipole moment, m, has been the precisely measured by applying external static electric and magnetic fields. el andm are used to give insight into the unusual complex bonding in these molecules. In addition to direct studies on the gold-containing molecules, other studies of related molecules are included here as well. These works contain the pure rotation measurement of PtC, the hyperfine and Stark spectroscopic studies of PtF, and the Stark and Zeeman spectroscopic studies of MgH and MgD. Finally, a perspective discussion and conclusion will summarize the results of AuF, AuCl, AuO, and AuS from this work (bond lengths, dipole moment, etc.). The highly quantitative information derived from this work is the foundation of a chemical description of matter and essential for kinetic energy manipulation via Stark and Zeeman interactions. This data set also establishes a synergism with computation chemists who are developing new methodologies for treating relativistic effects and electron correlation. / Dissertation/Thesis / Doctoral Dissertation Chemistry 2017

abstract: This thesis describes the studies for two groups of molecules in the gas-phase: (a) copper monofluoride (CuF) and copper hydroxide (CuOH); (b) thorium monoxide (ThO) and tungsten carbide (WC). Copper-containing molecules (Group a) are selected to investigate the ionic bonding in transition metal-containing molecules because they have a relatively simple electronic state distribution due to the nearly filled 3d-orbital. ThO and WC (Group b) are in support of particle physics for the determination of electron electric dipole moment (eEDM), de, the existence of which indicates new physics beyond the Standard Model. The determination of the tiny eEDM requires large electric fields applied to the electron. The 3(Delta)1 states for heavy polar molecules were proposed [E. R. Meyer, J. L. Bohn, and M. P. Deskevich, Phys. Rev. A 73, 062108 (2006)] to determine de with the following attractive features: (1) large electric dipole moments; (2) large internal electric fields, Eeff, experienced by valence electrons; (3) nearly degenerate omega-doublets; (4) extremely small magnetic dipole moments. The H3(Delta)1 state for ThO and the X3(Delta)1 state for WC are both good candidates. Spectroscopic parameters (i.e. molecular electric and magnetic dipole moments, omega-doubling parameters, etc) are required for the 3(Delta)1 states of ThO and WC. High resolution optical spectra (linewidth ~50 MHz) of CuF, CuOH, ThO and WC were recorded field-free and in the presence of a static electric field (or magnetic field) using laser ablation source/supersonic expansion and laser induced fluorescence (LIF) detection. The spectra were modeled by a zero-field effective Hamiltonian operator and a Stark (or Zeeman) Hamiltonian operator with various molecular parameters. The determined molecular parameters are compared to theoretical predictions. The small omega-doubling parameter was well determined using the pump/probe microwave optical double resonance (PPMODR) technique with a much higher resolution (linewidth ~60 kHz) than optical spectroscopy. In addition to the above mentioned studies of the two groups of molecules, a resonance enhanced multi-photon ionization (REMPI) combined with a time-of-flight mass spectrometer (TOFMS) has been developed to identify the molecules responsible for observed LIF signals. The operation of this spectrometer has been tested by recording the mass spectrum of Ti/O2 and the REMPI spectrum for TiO using a two-color excitation scheme. / Dissertation/Thesis / Ph.D. Chemistry 2012

Orientador: Paulo Mazzafera / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-12T20:42:22Z (GMT). No. of bitstreams: 1 Cesarino_Igor_M.pdf: 984828 bytes, checksum: 754aac1bc4502a9d5eb3102a955408d0 (MD5) Previous issue date: 2009 / Resumo: Uma grande quantidade de genes que codificam flavina monooxigenases (Flavin containing monooxygenases - FMOs) é encontrada em genomas vegetais, embora poucas funções biológicas tenham sido relacionadas com esse grupo de enzimas em plantas. Um importante papel desempenhado por FMOs é a conversão de triptamina em N-hidroxil niptamina, reação catalisada pelas proteínas YUCCA de Arabidopsis thaliana e que constitui o passo limitante da via de síntese de auxina a partir de triptofano. Proteínas similares às YUCCA foram descobertas e caracterizadas em outras espécies vegetais, como OsYUCCA em arroz. FLOOZY em petúnia, ToFZY em tomate e SPIl em milho, todas comprovadamente envolvidas na produção do hormônio citado. Análises da proteína recombinante CaFM08 de Coffea arabica revelou características similares às YUCCA, sugerindo que esta proteína de café é a primeira YUCCA-like descrita para esta espécie e, inclusive, para a família Rubiaceae. CaFM08 apresenta os mesmos motivos protéicos conservados entre FMOs vegetais, e particularmente entre proteínas YUCCA-like. O padrão de expressão espacial do gene que codifica CaFM08 indica possível relação com o desenvolvimento de raízes, folhas e flores de café. Apesar de grandes semelhanças com as proteínas YUCCA, a atividade de N-hidroxilação da triptamina não foi comprovada para CaFM08 recombinante in vitro. Uma análise minuciosa a respeito da funcionalidade de CaFM08 produzida em E. coli deve ser feita antes de descartar a participação desta proteína na síntese de auxina. / Abstract: A large number of genes coding flavin-containing monooxygenases (FMOs) is found in plant genomes, although only few biological functions have been related with these enzymes in plants. An important role for FMOs is the conversion of tryptamine in N-hydroxyl triptamine, catalyzed by the YUCCA protein family in Arabidopsis thaliana. These proteins perform "the rate-limiting step in tryptophan-dependent auxin biosynthesis. Similar YUCCA proteins were discovered and characterized in other plant species, like OsYUCCA in rice, FLOOZY in petunia, ToFZY in tomato and SPIl in maize. All of them are shown to be involved in auxin synthesis. Analysis of the recombinant CaFM08 from Colfea Arabica showed features similar to YUCCA proteins, suggesting that CaFM08 is the first described YUCCA-like protein from coffee and, indeed, from the entire Rubiaceae family. CaFM08 has the same conserved motifs found in other plant FMOs and particulary conserved in YUCCA like proteins. The spatial expression pattern from the CaFM08 coding gene suggests a probable role in the development of roots, leaves and flowers. Although very similar to YUCCA proteins, the CaFM08-mediated convertion of tryptamine in N-hydroxyl tryptamine has not been confirmed in vitro. A further analysis of CaFM08 functionality should address the relation of CaFM08 to auxin production. / Mestrado / Mestre em Biologia Vegetal

Por décadas a radiação infravermelha tem sido usada de forma estética e terapêutica, e é caracterizada por ter a propriedade de penetrar na pele. O surgimento de novas tecnologias permitiu a criação de têxteis funcionais, entre eles os tecidos contendo biocerâmica, que absorvem o calor do corpo, ativando a biocerâmica presente e emitindo raios infravermelhos longos, que penetram na pele ativando a microcirculação sanguínea. Porém, tecidos desse tipo só tiveram eficiência comprovada por testes clínicos, que são métodos caros e demorados, ou por analogia baseada no tipo de construção. O objetivo deste estudo foi elaborar um método prático para medir a emissividade de tecidos contendo biocerâmica, utilizando um espectrofotômetro de raios infravermelhos, comparar a emissividade desses tecidos, além de realizar uma análise de fluorescência de raios X a fim de descobrir os elementos químicos presentes nos tecidos, para confirmar quaisquer diferenças de emissividade entre os mesmos. Concluiu-se que é possível medir a emissividade de tecidos contendo biocerâmica através do aquecimento das amostras, simulando a ação do tecido junto ao corpo, e posteriormente realizando ensaios em um espectrofotômetro de infravermelhos por transformada de Fourier, onde picos de emissão foram encontrados em cada tecido analisado, o que possibilitou o cálculo da emissividade (expressa em contagens de área) através do ajuste de uma curva gaussiana em cada pico de emissão. Através da fluorescência de raios X foram encontrados diferentes elementos químicos na composição das amostras, podem ser a causa da diferença de emissividade entre os tecidos / The infrared radiation has been used on aesthetic and therapeutic way for decades, and is characterized for being able to penetrate deeply underneath the skin. New technologies appeared, enabling the development of functional textiles, among them textiles containing bioceramics that absorb the body heat, activating the bioceramic on it and emitting far infrared rays, which penetrate into the skin, activating the blood microcirculation. However, the efficiency of this sort of fabrics was proven only by clinical tests, which are very expensive and time consuming, and by construction analogy. The main objective of this study was to develop a practical method for measuring fabrics containing bioceramics emissivity, using an infrared spectrophotometer, comparing the fabrics emissivity, besides doing an X ray fluorescence analysis in order to discover the chemical elements that composes the fabrics, to confirm any emissivity differences between them. It was concluded that it is possible to measure the emissivity of fabrics containing bioceramics by heating the samples, simulating the action of the fabric on the body, and subsequently performing tests on a Fourier transform infrared spectrophotometer, where emission peaks were found on the fabrics, that enabled the emissivity calculation (expressed in area counts) by adjusting a Gaussian curve at each emission peak. By the X ray fluorescence different chemical elements were found on the fabrics composition, which can be the reason for the emissivity difference between them

Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第15670号 / 工博第3328号 / 新制||工||1502(附属図書館) / 28207 / 京都大学大学院工学研究科材料化学専攻 / (主査)教授 田中 勝久, 教授 平尾 一之, 教授 横尾 俊信 / 学位規則第4条第1項該当

Philosophiae Doctor - PhD / Global climate change has resulted in altered rainfall patterns, causing annual losses in maize crop yield due to water deficit stress. Therefore, it is important to produce maize cultivars which are more drought-tolerant. This not an easily accomplished task as plants have a plethora of physical and biochemical adaptation methods. One such mechanism is the drought-induced expression of enzymatic and non-enzymatic proteins which assist plants to resist the effects of water deficit stress. The RD22-like protein subfamily is expressed in response to water deficit stress. Members of the RD22-like subfamily include AtRD22, GmRd22 and BnBDC1 which have been identified in Arabidopsis thaliana, Glycine max and Brassica napus respectively. This study aims at characterising two putative maize RD22-like proteins (designated ZmRd22A and ZmRd22B) by identifying sequence/domain features shared with characterised RD22-like proteins. Semi-quantitative and quantitative PCR techniques were used to examine the spatial and temporal expression patterns of the two putative maize Rd22-like proteins in response to, water deficit stress and exogenously applied abscisic acid in the roots and 2nd youngest leaves of maize seedlings. Using an in silico approach, sequence homology of the two putative maize Rd22- like proteins with AtRD22, GmRD22 and BnBDC1 has been analysed. Online bioinformatic tools were used to compare the characteristics of these Rd22-like proteins with those of the two maize proteins. It was shown that the putative maize RD22-like proteins share domain organisation with the characterised proteins, these common features include a N-terminal hydrophobic signal peptide, followed by a region with a conserved amino acid sequence, a region containing several TxV (x is any amino acid) repeat units and a C-terminal BURP domain-containing the conserved X₅-CH-X₁₀-CH-X₂₃-₂₇-CH-X₂₃-₂₆-CH-X₈-W motif. The putative maize Rd22-like protein appears to be localized in the apoplast, similarly to AtRD22, GmRD22 and BnBDC1. Analysis of the gene's promotor regions reveals cis-acting elements suggestive of induction of gene expression by water deficit stress and abscisic acid (ABA). Semi-quantitative and quantitative real time PCR analysis of the putative maize RD22-like gene revealed that the genes are not expressed in the roots. Exposure to water deficit stress resulted in an increase of ZmRD22A transcript accumulation in the 2nd youngest leaves of maize seedlings. ZmRD22A was shown to be non-responsive to exogenous ABA application. ZmRD22B was highly responsive to exogenous ABA application and responded to water deficit stress to a lesser degree. Transcript accumulation studies in three regions of the 2nd youngest leaves in response to water deficit stress showed that ZmRd22A transcripts accumulate mainly at the base and tips of the leaves. A restricted increase in ZmRD22A transcript accumulation in the middle of the leaves was observed. ZmRD22B showed a similar, but weaker transcript accumulation pattern in response to water deficit stress. However, ZmRD22B showed increased transcript accumulation in the middle region of the leaves. In response to exogenous ABA application, ZmRd22B exhibited high transcript accumulation at the base of the 2nd youngest leaves, with the middle showing higher transcript accumulation than the tip of the leaves. It was concluded that ZmRD22A and ZmRD22B share the domain organisation of characterised RD22-like proteins as well as being responsive to water deficit stress, although only ZmRD22B was shown to be responsive to exogenous ABA application. / National Research Foundation (NRF)

Fulgides and fulgimides comprise one class of thermally irreversible photochromic organic compounds. Light dependent isomerization, has made these organic molecules promising materials for several applications, including optical memory devices, and switches. Hydrolytic stability of fulgides and fulgimides is crucial for their practical applications in biological systems and humid environments. Fulgimides, the most important derivative of fulgides, have a succinimide ring, which, unlike the anhydride ring, of fulgides, is resistant to hydrolytic degradation. A novel N-alkylindolylfulgimide was synthesized and copolymerized with acrylamide. The photochromic and hydrolytic properties of the copolymer in phosphate (pH 7.4) and acetate (pH 5.0) buffer solutions were characterized. The N-alkylindolylfulgimide based copolymer exhibited significantly enhanced hydrolytic stability (50 times better in phosphate buffer) and similar photochromic properties as a copolymer containing an N-arylindolylfulgimide.

<p>Cyclobutane pyrimidine dimers (CPD) are the predominant DNA lesions formed upon exposure of this biopolymer to sunlight. Given the potentially dire biological consequences of DNA lesions, there is a need to fully characterize their behaviour, with an eye towards understanding their complete reactivity and as a possible means to detect and quantify their presence in the genome. The work described in this dissertation describes studies of the alkaline reactivity of CPD lesions generated within dinucleotide & polynucleotide strands. It was found that CPD-TpT is generally inert under alkaline conditions at room temperature, which is in agreement with earlier studies on alkaline hydrolysis of CPD-thymine and CPD-thymidine. However, a re-evaluation of the same reaction in the presence of ¹⁸O labelled water demonstrated that, similar to other UV-induced DNA lesions containing a saturated pyrimidine ring, CPD undergoes a water addition at the C4=O group of the nucleobase leading to the formation of a hemiaminal intermediate. This intermediate, however, does not lead to hydrolysis products and completely reverts to starting material under those same conditions. Moreover, the two C4=O groups present on 3′ and 5′-thymines in a CPD molecule show different chemical reactivities, with the 3′ C4=O group having greater affinity towards water addition as compared to the one on 5′ end, a fact reflected in different rates of exchange with the incoming nucleophile leading to the hemiaminal intermediate. The ¹⁸O labelling reaction was also investigated in CPD lesions generated within oligonucleotides to probe the cause of asymmetry between the 3′ <i>vs</i> 5′ C4=O groups; ultimately, it was determined that the asymmetric reactivity observed to occur between the two C4=O groups was an intrinsic property of the CPD molecule and did not arise as a result of asymmetry in a dinucleotide setting.</p><p><br></p> <p>In addition to the above studies, during the course of the investigation of the nucleophilic reactivity of CPD, a chemical reaction was observed leading to what appeared to be the rapid and total chemical reversal of CPD lesions to the original TpT (thymine-thymine dinucleotide)! This “repair” reaction occurred when CPD reacted with hydrazine, and appears facilitated by an inert atmosphere under which it rapidly proceeds to completion at room temperature.</p><br>