Thesis (M.Sc.). / Written for the Dept. of Neurology and Neurosurgery. Title from title page of PDF (viewed 2009/08/07). Includes bibliographical references.

Η έρευνα για την ασφάλεια της κυκλοφορίας γίνεται για να αποτρέψει τα ατυχήματα και να μειώσει τη δριμύτητα των τραυματισμών στο δρόμο, και αποτελεί σημαντικό θέμα στον τομέα της εφαρμοσμένης μηχανικής των μεταφορών δεδομένου ότι στοχεύει να σώσει ανθρώπινες ζωές. Η παρούσα εργασία έχει ως σκοπό την εύρεση μιας συνάρτησης που εκτιμά σε πραγματικό χρόνο μία συγκεκριμένη κυκλοφοριακή μεταβλητή, τον χρονικό διαχωρισμό, η οποία μπορεί να χρησιμοποιηθεί ως πρόδρομος ατυχήματος ή παρ’ ολίγον ατυχήματος. Η έρευνα αυτή έγινε σε τμήμα του αυτοκινητοδρόμου Ι-94, που αποτελεί σύνδεσμο μεταξύ των πόλεων St. Paul και Minneapolis και παρουσιάζει φόρτο 80.000 οχήματα ανά κατεύθυνση και κυκλοφοριακή συμφόρηση τουλάχιστον για 5 ώρες καθημερινά. Εξετάστηκαν τέσσερις ανεξάρτητες μεταβλητές και διερευνήθηκε η συσχέτιση του χρονικού διαχωρισμού με τις τρέχουσες και παρελθούσες τιμές των μεταβλητών αυτών. Με την μέθοδο της παλινδρόμησης υπολογίζεται η σημαντικότητα κάθε μεταβλητής. Επίσης υπολογίζεται το βάθος χρόνου στο οποίο η πιθανή συσχέτιση είναι σημαντική. Συμπεραίνεται ότι είναι δυνατή η εκτίμηση του χρονικού διαχωρισμού 2–5 λεπτά πριν παρατηρηθεί, αναλόγως της κυκλοφοριακής κατάστασης. / The research on traffic safety seeks to prevent accidents and reduce the severity of injuries on the road, and is an important area in the field of transportation engineering as it aims to save lives. This study aims to identify a function that estimates, in real time, a specific traffic variable, time headway, that can be used as a precursor to an accident or near accident. The method is applied in a section of freeway I-94 between St. Paul and Minneapolis that carries 80,000 vehicles in each stream and experiences traffic congestion for at least 5 hours daily. Four independent variables were considered and the relationship between time headway and current and past values of these variables was examined. Using regression, the significance of each variable was determined. Further, the extent in time for which such relationship is significant was also determined. It is concluded that estimation of time headway is feasible, 2-5 minutes prior to occurrence, depending on traffic conditions.

Made available in DSpace on 2014-06-11T19:35:45Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-02-28Bitstream added on 2014-06-13T20:26:51Z : No. of bitstreams: 1 tavares_ba_dr_bauru.pdf: 1248092 bytes, checksum: da6929f1575f2be1fe621cd06198cce0 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Dentre os compostos mais pesquisados atualmente encontram-se os eletrólitos sólidos com elevada condutividade iônica, pois estes apresentam potenciais aplicações em baterias de estado sólido, entretanto, na literatura, há poucos trabalhos que descrevam o processo de preparação e caracterização de pós com estrutura tipo perovskita para aplicações como catodos em baterias de lítio. Assim, este projeto teve como objetivo o desenvolvimento do processo de preparação do pó de La0.50Li0.50TiO3 pelo método de precursores poliméricos. O comportamento térmico do pó obtido a 350ºC foi avaliado através das técnicas de Análise Termogravimétrica (TGA) e Análise Térmica Diferencial (DTA); já a evolução térmica do pó obtido a 350 e 700ºC foi analisada por meio das técnicas espectroscópicas de Infravermelho (IR) e Raman. O processo de cristalização do pó foi realizado por Difração de Raios X (DRX), em conjunto com o Método de Rietveld que identificou uma fase pervskita altamente cristalina durante o processo de cristalização, no entanto, uma fase secundária, LiTi2O4, também foi detectada. A morfologia do pó foi observada por Microscopia Eletrônica de Varredura (MEV-FEG), que revelou uma microestrutura de grãos esféricos e homogêneos. Quanto às medidas eletroquímicas, foram utilizadas as técnicas de Titulação Galvanostática Intermitente (GITT), Cronopotenciometria e Voltametria Cíclica que evidenciaram a presença de dois processos cinéticos diferentes / Among the most researched compounds currently are the solid electrolytes with high ionic conductivity, because of their potential applications in solid state batteries, however, in the literature there are few studies that describe the preparation and characterization of powders with perovskite structure for applications such as cathodes in lithium batteries. Thus this project aimed to develop the process of preparing the powder La 0.50Li0.50TiO3 by the polymeric precursor method. The thermal behavior of the power obtained at 350ºC was evaluated using the techniques of Thermogravimetric analysis (TGA) and Differential Thermal Analysis (DTA), whereas the thermal evolution of the power obtained at 350 and 700ºC was analyzed by spectroscopic techiniques IR and Raman. The crystallization process was analyzed by X-ray powder diffraction together with the Rietveld Method that identified a highly crystalline perovskite phase during the crystallization process; however, a secondary phase LiTi2O4 was also detected. The morphology of the powder was observed by field emission gun scanning electron microscopy (FEG-SEM), which revealed a microstructure of spherical and homogeneous grains. As for the eletrochemical measurements, we have used the Galvanostatic Intermittent Intermittent Titration Technique (GITT), Chronopotenciometry and Cyclic Voltammetry demonstrating the presence of two different kinetic processes

abstract: Identification of early damage in polymer composite materials is of significant importance so that preventative measures can be taken before the materials reach catastrophic failure. Scientists have been developing damage detection technologies over many years and recently, mechanophore-based polymers, in which mechanical energy is translated to activate a chemical transformation, have received increasing attention. More specifically, the damage can be made detectable by mechanochromic polymers, which provide a visible color change upon the scission of covalent bonds under stress. This dissertation focuses on the study of a novel self-sensing framework for identifying early and in-situ damage by employing unique stress-sensing mechanophores. Two types of mechanophores, cyclobutane and cyclooctane, were utilized, and the former formed from cinnamoyl moeities and the latter formed from anthracene upon photodimerization. The effects on the thermal and mechanical properties with the addition of the cyclobutane-based polymers into epoxy matrices were investigated. The emergence of cracks was detected by fluorescent signals at a strain level right after the yield point of the polymer blends, and the fluorescence intensified with the accumulation of strain. Similar to the mechanism of fluorescence emission from the cleavage of cyclobutane, the cyclooctane moiety generated fluorescent emission with a higher quantum yield upon cleavage. The experimental results also demonstrated the success of employing the cyclooctane type mechanophore as a potential force sensor, as the fluorescence intensification was correlated with the strain increase. / Dissertation/Thesis / Doctoral Dissertation Chemical Engineering 2014

Made available in DSpace on 2014-10-09T12:54:30Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:09:22Z (GMT). No. of bitstreams: 0 / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energéticas e Nucleares - IPEN/CNEN-SP

Made available in DSpace on 2014-10-09T12:54:30Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:09:22Z (GMT). No. of bitstreams: 0 / O ozônio (O3) representa o principal poluente atmosférico para a Região Metropolitana de São Paulo (RMSP), sendo freqüentes os dias em que sua concentração excede os padrões nacionais de qualidade do ar. Por se tratar de um poluente secundário, resultante principalmente, da interação entre os óxidos de nitrogênio (NOx) e compostos orgânicos voláteis (COVs) na presença de luz solar, torna-se muito difícil a elaboração de estratégias eficazes para a redução deste poluente. A utilização de simulação computacional se mostra como uma interessante alternativa para avaliar os muitos fatores que afetam a formação de O3, para o desenvolvimento de escalas de reatividade para COVs e para definição de possíveis estratégias que visem a redução dos níveis de O3. Neste trabalho foi utilizado o modelo de trajetórias OZIPR (Ozone Isopleth Package for Research) em conjunto com o modelo químico SAPRC (Statewide Air Pollution Research Center) para se determinar a escala de reatividade incremental para COVs para a cidade de São Paulo e para a simulação de diversas situações de redução das emissões de NOx e COVs. Para alimentar os modelos foram utilizadas medidas de COVs de duas campanhas: uma realizada pelo Laboratório de Química Atmosférica (LQA-IPEN) em conjunto com a CETESB na estação Cerqueira César, no período de agosto e setembro de 2006 e outra realizada somente pelo LQA durante todo o ano de 2006 com amostragens na Cidade Universitária. Dados de CO, NOx e parâmetros meteorológicos foram obtidos através dos monitores automáticos da mesma estação e da estação Pinheiros. Foram criados cinco casos base: um com os dados de COVs da estação Cerqueira César e quatro com os dados da Cidade Universitária, sendo estes, um para cada estação do ano. Após o ajuste dos casos base, cada COV presente na mistura teve sua concentração aumentada e diminuída em 0,2% dos COVs totais para se verificar a variação no máximo de ozônio e assim se determinar o potencial de formação de ozônio de cada COV. Estes resultados forneceram uma escala de reatividade para ozônio para cada caso base criado. Foram também realizadas simulações, onde as emissões horárias de NOx e COVs foram reduzidas em 5, 10, 20 e 30% independente e simultaneamente afim de se verificar as variações na formação de O3. Com os dados de saída do simulador foram construídos gráficos de isopletas de ozônio para a cidade de São Paulo. A análise dos resultados obtidos mostrou que os compostos encontrados com mais freqüência entre os dez principais precursores de ozônio na cidade de São Paulo nas escalas de reatividade criadas a partir dos cinco casos base são: formaldeído, acetaldeído, propeno, isopreno, cis e trans 2-buteno, sendo o formaldeído sempre o principal composto formador de ozônio. As simulações mostraram também que uma estratégia eficaz para se reduzir os níveis de O3 na cidade de São Paulo é diminuir as emissões totais de COVs. O mesmo não foi observado para os NOx, já que a redução destes poluentes faria aumentar as concentrações de O3. / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energéticas e Nucleares - IPEN/CNEN-SP

It is widely accepted that A-beta (Aβ) generated from amyloid precursor protein (APP) oligomerizes and fibrillizes to form neuritic plaques in the Alzheimer’s disease (AD) brain, yet little is known about the contribution of APP preceding AD pathogenesis. Our data presented here suggest that APP has a functional role in cell cycle regulation and proliferation. First, we demonstrat that APP is pathologically phosphorylated at Thr668 and that P-APP localizes to the centrosomes. Furthermore, P-APP is proteolytically processed in a cell cycle -dependent manner to generate its pathogenic metabolites. Using Stable Isotope Labeling by Amino Acids in Culture (SILAC) and mass spectrometry analyses, we also show that expression of APP results in the expression of proliferation-associated proteins and the phosphorylation of proteins associated with cell cycle regulation and transcription. Here, we demonstrate that APP expression and oligomeric Aβ42 elicit Ras/ERK signaling cascade and glycogen synthase kinase3 (GSK3) activation. Both ERK and GSK3 are known to induce hyperphosphorylation of tau and of APP at Thr668, and our findings suggest that aberrant signaling by APP facilitates these events. Supporting this notion, analysis of human brain samples show increased expression of Ras, activation of GSK3 and phosphorylation of APP and tau, which correlate with Aβ levels in the AD brains. Furthermore, treatment of primary rat neurons with Aβ recapitulate these events and show enhanced Ras-ERK signaling, GSK3 activation, upregulation of cyclin D1, and phosphorylation of APP and tau. The finding that Aβ induces Thr668 phosphorylation on APP, which we show enhances APP proteolysis and Aβ generation, denotes a vicious feed-forward mechanism by which APP and Aβ promote tau hyperphosphorylation and neurodegeneration in AD. Based on these results we hypothesize that aberrant proliferative signaling by APP plays a fundamental role in AD neurodegeneration and an inhibition of this would impede the mitotic catastrophe and neurodegeneration observed in AD.

The NF-κB family of transcription factors controls a number of essential cellular functions. Pirin is a non-heme iron (Fe) redox specific co-regulator of NF-κB (p65) and has been shown to modulate the affinity between the homodimeric p65 and the DNA. The allosteric effect of the active Fe(III) form of Pirin on the DNA is not known and has not been investigated. We carry out multiple microsecond-long molecular dynamics simulations of the free DNA, p65-DNA complex, and the Pirin-p65-DNA supramolecular complexes in explicit water. We show that, unlike the Fe(II) form of Pirin, the Fe(III) form in the Pirin-p65-DNA supramolecular complex enhances the interactions and affinity between p65 and the DNA, in agreement with experiments. The results further provide atomistic details of the effect of the Fe(III) form of Pirin on the DNA upon binding to p65 to form the supramolecular complex.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第22040号 / 医博第4525号 / 新制||医||1038(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 高橋 淳, 教授 伊佐 正, 教授 渡邉 大 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第22310号 / 医博第4551号 / 新制||医||1040(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 渡邉 大, 教授 万代 昌紀, 教授 影山 龍一郎 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM