A pesquisa teve como objetivo compreender o papel dos rearranjos de drenagem à evolução do relevo e da drenagem na bacia hidrográfica do Rio Capivari, situada no reverso da Serra do Mar, em São Paulo-SP. Parte-se da hipótese de que esses fenômenos seriam responsáveis por inúmeras anomalias de drenagem observadas, como: inflexões em ângulos retos, padrões de drenagem anômalos, colos, rupturas em perfis longitudinais e subdimensionamento de cursos dágua em relação aos vales. Especial ênfase foi dada à inflexão do alto Rio Capivari, localizada na confluência com o Ribeirão Embura, possível remanescente de uma captura fluvial, o qual melhor preserva as evidências de um rearranjo em toda a bacia. Os principais fatores dos rearranjos de drenagem na área foram: o forte gradiente hipsométrico proporcionado pela Serra do Mar, a densa trama de foliações e fraturas presentes no embasamento geológico, movimentações tectônicas recentes e as oscilações paleoclimáticas do Quaternário tardio. Sob influência dessas forças, alguns tributários da drenagem litorânea teriam se aproveitado de sua vantagem erosiva frente aos rios de planalto, produzido uma marcha de erosão regressiva em direção ao interior, com interferências nos canais situados em níveis sucessivamente mais elevados. Com base nas propostas metodológicas de Small (1972), Bishop (1995), Zaprowski et al. (2002) e Oliveira (2003), buscou-se a identificação de elementos morfológicos e sedimentológicos sugestivos desses processos, por meio de: análise de Modelos Digitais do Terreno (MDE) por métodos geomorfométricos; observação de fotografias aéreas; trabalhos de campo para descrição e coleta de materiais sedimentológicos; análise granulométrica, morfoscópica e mineralógica de sedimentos fluviais; e datação de sedimentos fluviais por Luminescência Óptica Estimulada para se estimar a idade da captura do alto curso do Rio Capivari. Os dados apresentados corroboram a hipótese de que o alto curso desse rio sofreu uma captura há cerca de 8.000 anos, no máximo, e que diversos outros casos de rearranjos de drenagem, entre eles reversões de grandes sistemas fluviais, seriam responsáveis pelas anomalias de drenagem observadas no interior da bacia estudada. / The aim of this research was to understand the role of drainage rearrangements on the evolution of relief and drainage in the Capivari River basin, located on the reverse of Serra do Mar range, in the state of São Paulo, Brazil. It is assumed that these phenomena would be responsible for numerous drainage anomalies observed, such as: river inflections at right angles, anomalous drainage patterns, cols, knickpoints and river underfitting, considered as indicative for drainage rearrangements. Special emphasis will be given to the inflection of the Capivari River at the confluence with the Ribeirao Embura, a possible remnant of a stream capture, which best preserves the evidence of a rearrangement throughout the basin. The main factors of the drainage rearrangements in the area would be: the strong hypsometric gradient provided by Serra do Mar range, the set of foliations and fractures densely present in the geological basement, recent tectonic movements and climatic oscillations of the Quaternary. Under the influence of these forcings, some tributaries of the coastal drainage would have taken erosive advantage over the plateau upside rivers, producing a regressive erosion march towards the interior of the continent, leading to interferences in the river systems situated at successively higher levels. Based on the methodological proposals of Small (1972), Bishop (1995), Zaprowski et al. (2002) and Oliveira (2003), we seek the identification of morphological and sedimentological elements that are suggestive of these processes, by means of: Digital Elevation Models (DEM) analysis by geomorphometric methods; observation of aerial photographs; fieldwork for description and collection of sedimentological materials; granulometric, morphoscopic and mineralogical analysis of fluvial sediments; and dating of fluvial sediments by Optically Stimulated Luminescence to estimate the age of capture of the upper reaches of the Capivari River. The presented data corroborate the hypothesis that the high course of the Capivari river was captured at least 8,000 years ago and that several other cases of drainage rearrangements, including reversals of large river systems, would be responsible for the observed drainage anomalies.

Devido à inexistência de um laboratório de padronização primária na América Latina, para calibração e dosimetria de fontes de radiação beta, neste trabalho uma câmara de extrapolação Böhm foi caracterizada e estabelecida como um sistema padrão primário no Laboratório de Calibração de Instrumentos (LCI) do IPEN. Como objetivo principal deste trabalho, a câmara de extrapolação Böhm foi caracterizada com relação à sua resposta em feixes padrões secundários de radiação beta de fontes de 90Sr+90Y, com duas janelas de entrada diferentes: Mylar aluminizado e Hostaphan grafitado, e com dois métodos de determinação de taxa de dose absorvida, para verificação do seu desempenho com cada material. Embora se trate do instrumento mais adequado para a calibração de detectores e fontes de radiação beta, a câmara de extrapolação deve ser utilizada apenas em laboratórios de calibração e não em programas de controle de qualidade, pois ela tem 7 kg e é de alto custo. Assim, é importante ter sistemas considerados padrões de trabalho e métodos alternativos para substituir a câmara de extrapolação em medições realizadas em campo, como em hospitais ou clínicas. Por este motivo, foram caracterizadas três câmaras de ionização de placas paralelas, com o objetivo de se verificar a possibilidade de seu uso como sistemas padrões de trabalho em programas de controle de qualidade, e também foram estudados materiais dosimétricos diferentes, em campos de radiação beta de 90Sr+90Y, utilizando-se os fenômenos da termoluminescência (TL) e da luminescência opticamente estimulada (LOE), como métodos alternativos na calibração de fontes de radiação beta. Inclui-se aqui o desenvolvimento de um sistema postal dosimétrico para a calibração de aplicadores clínicos de 90Sr+90Y. Os resultados obtidos com a câmara de extrapolação Böhm permitiram o seu estabelecimento como sistema padrão primário na calibração de fontes de 90Sr+90Y, pois a câmara com as duas janelas de entrada diferentes permitiram a determinação de taxas de dose absorvida no ar e no tecido, à profundidade nula e a 0,07 mm. A caracterização das três câmaras de ionização de placas paralelas mostraram que elas podem ser usadas em programas de controle de qualidade de fontes de radiação beta, pois suas respostas se apresentaram adequadas para esta finalidade. Os materiais dosimétricos testados com relação às suas respostas TL e LOE também se mostraram adequados para uso em campos de radiação beta, pois suas respostas foram satisfatórias. O sistema dosimétrico, utilizando dosímetros TL, foi testado em hospitais e, posteriormente, foi enviado na forma postal a um laboratório, contendo detectores TL e LOE, e o resultado da calibração dos aplicadores clínicos foi adequado. / Due to the lack of a primary standard laboratory at the Latin America, for the calibration and dosimetry of beta radiation sources, it was decided to establish the Böhm extrapolation chamber at the Calibration Laboratory (LCI) at IPEN as a primary standard. As a main objective of this work, the Böhm extrapolation chamber was characterized in relation to its response in beta radiation secondary standard beams of 90Sr+90Y sources, using two different entrance windows: aluminized Mylar and graphited Hostaphan, and using two methods of determination of absorbed dose rates, to verify its performance in each material. Although it is the most adequate instrument for the calibration of beta radiation detectors and sources, the extrapolation chamber should only be used at calibration laboratories, and not in quality control programs, because it weights 7 kg, and it is expensive. Thus, it is important to have systems considered work standards and alternative methods to replace the extrapolation chamber in measurements performed outside laboratories, such as in hospitals and clinics. For this reason, three parallel plate ionization chambers were characterized, with the objective to verify the possibility of their use as work standard systems, and different dosimetric materials were also studied, in beta radiation fields, using the thermoluminescence (TL) and optically stimulated luminescence (OSL) phenomena, as alternative methods for the calibration of beta radiation sources. The development of a dosimetric postal system for the calibration of 90Sr+90Y clinical applicators was included in this objective. The results obtained using the Böhm extrapolation chamber allowed its establishment as a primary standard system at the calibration of 90Sr+90Y sources, because it was possible to determine the absorbed dose rates in air and in the tissue, at null depth and 0.07 mm using the chamber with the two different entrance windows. The characterization of the three parallel plate ionization chambers showed that they can be used in quality control programs of beta radiation sources, because their responses were adequate to this purpose. The dosimetric materials were tested in relation to their TL and OSL response, and their use showed also to be adequate in beta radiation fields. The dosimetric postal system, using TL dosimeters, was tested in hospitals, and afterwards, it was sent to a laboratory, by conventional mail, with TL and OSL detectors, and the results of the calibration of the clinical applicators was adequate.

Ametistas naturais brasileiras foram estudadas através das técnicas de Absorção Óptica (AO), Ressonância Paramagnética Eletrônica (RPE) e Corrente de Despolarização Termicamente Estimulada (CDTE).O espectro de AO apresentou três picos principais na região espectral do visível (10500, 18600 e 28200cm POT.-1) e um enorme pico na região do ultravioleta (45000cm POT.-1) atribuídos ao ferro em diferentes estados de valência. A presença de centros OH POT.- foi observada na região do infravermelho através das bandas em 3440 e 3580cm POT.-1. O espectro de RPE, operando na banda X, exibe um conjunto de linhas centrado em 2000G, um pico intenso em 3000G e quatro picos pequenos em 4000, 5000, 6000 e 7000G, quando o campo magnético encontra-se paralelo a um dos eixos cristalograficamente equivalentes. Quando o campo magnético encontra-se paralelo ao eixo c do cristal, o espectro de RPE revela um conjunto de linhas centrado em 2000G, dois picos intensos próximos a 5000G e um pico pequeno em 6800G. Amostras em pó apresentam uma banda larga centrada em 3400G. Tratamentos térmicos mostram uma redução gradativa desta banda com o aumento do tempo de tratamento térmico e uma redução mais rápida para temperaturas maiores. Sabe-se que os centros de cor nas ametistas são produzidos pela ação de radiação ionizante natural sobre os centros precursores que surgem da substituição do Si POT.4+ pelo Fe POT.3+ na estrutura do quartzo-alfa. Esses centros de Fe POT.3+ não se distribuem igualmente entre os sítios equivalentes no cristal natural e são responsáveis pelas características dominantes do espectro de RPE. O espectro de CDTE obtido da polarização de uma amostra em 1000V apresenta uma banda em 215K, que vem a ser a composição de três bandas de menor intensidade (185, 200 e 214K) e uma banda única em 260K. Foi confirmado o caráter dipolar dessas bandas. Tratamentos térmicos efetuados a diferentes temperaturas mostram ) um decaimento de área total e uma redução da intensidade das bandas mais acentuadas para temperaturas maiores. Iluminação ultravioleta restaura parcialmente o espectro de CDTE e demonstra o crescimento de uma banda na região da temperatura ambiente. Devido ao comportamento semelhante dos espectros de CDTE e de RPE, o sendo Fe POT.3+ um elemento presente em grande quantidade nas amostras estudadas, acredita-se que o centro de dipolo responsável pelas bandas de CDTE observadas, seja do Fe POT.3+ substituindo um Si POT.4+ próximo a um O POT.- ou a um OH POT.-, e que as diferentes posições dos picos devem-se à população desigual do Fe POT.3+ substitucional nos sítios cristalograficamente equivalentes do cristal. / Brazilian natural amethyst samples have been studied through Optical Absorption (AO), Electron Paramagnetic Resonance (EPR) and Thermally Stimulated Depolarization Current (TSDC) Techniques.The AO spectrum shows three main peaks in the visible region (10500, 18600 e 28200cm POT.-1) and a huge peak in the ultraviolet region (45000cm POT.-1). All these peaks were attributed to iron in different valence states. The presence of centros OH POT.- centres have been observed through the bands at 3440 e 3580cm POT.-1in the infrared.The EPR spectrum shows a set of lines centered at 2000G, an intense peak at 3000G and four small peaks at 4000, 5000, 6000 and 7000G, when the magnetic field is parallel to one of crystallographically equivalents sites. When the magnetic field is parallel to the crystal c-axis, the EPR spectrum shows a set of lines centered at 2000G, two high peaks near 5000G and a small peak at 6800G. Powder samples presents a broad band centered in 3400G. Thermal treatments reduce this band for increasing thermal treatments time intervals. The reduction increases for high temperatures. It is well known that colour centres in amethysts are produced after natural ionizing radiation and that the centres are provided with the substitution of Fe POT.3+ for Si POT.4+ in quartzo-alfa structure. The Fe POT.3+ centres are not equally distributed among the equivalent sites of the natural crystal and are responsible for the dominant features of the EPR spectra. The obtained TSDC spectrum for polarization at 1000V shows a broad band at 215K, resulting from the superposition of three bands at 185, 200 and 214k and another band at 260K. The dipole origin of these bands has been confirmed. Thermal treatments at different temperatures produce a decay of the total area and a reduction of the bands intensities. Thermal reduction increases for higher temperatures. Ultraviolet illumination partially restores the TSDC spectrum. A new band appears at room temperature. Due to the similar behavior of the TSDC and EPR spectra and taking into account that the Fe POT.3+ is the most prominent impurity in the studied samples, we believe that the dipoles are substitutional Fe POT.3+ near O POT.- or an OH POT.- and that the different position of the peaks, very near, but not the same, are in crystallographically equivalent sites.

No estudo do transporte e armazanamento de cargas elétricas, em filmes de Teflon FEP, utilizamos a Técnica de Pulso Térmico em conjunto com a Técnica de Corrente Termoestimulada em circuito aberto. Através das duas técnicas, pudemos acompanhar a evolução das cargas nas amostras (de 25 &#956m) submetidas ao Annealing e a descarga iônica em diferentes situações, comparando os resultados obtidos em amostras virgens com as amostras tratadas ou irradiadas. No caso das amostras irradiadas, verificamos que o contato era injetor de buracos e, posteriormente, sugerimos a dependência da mobilidade de buracos com o campo elétrico aplicado. Na tentativa de explicar os resultados obtidos, fizemos uso de alguns modelos teóricos de correntes limitadas por carga espacial. / The Heat Pulse and TSC (Thermo-Stimulated-Current) in open circuit techniques were used to study the transport and storage of injected charge in Teflon FEP films. Using these techniques it was possible to follow the evolution of the injected charge inside the samples. Virgin samples (as received), previously annealed samples and previously ionic bombarded samples were used. The results of treated samples were compared with the results of virgin samples. Aluminum evaporate contacts covering ionic bombarded surface show hole injection properties. Measurement of space charge limited currents shows a mobility dependent of the electrical field (&#956 &#945 E-1/2).

Chan Pui Kwan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 98-104). / Abstracts in English and Chinese. / TABLE OF CONTENTS --- p.i / LIST OF FIGURES --- p.iv / LIST OF TABLES --- p.vii / ABBREVIATIONS --- p.viii / Chapter Chapter one --- Research Background / Chapter 1.1 --- Carbohydrates --- p.2 / Chapter 1.2 --- Impact of molecular weight of polysaccharides --- p.5 / Chapter 1.3 --- Molecular Weight Determination of polysaccharides --- p.6 / Chapter 1.3.1 --- Laser Scattering --- p.6 / Chapter 1.3.2 --- Gel Permeation Chromatography --- p.7 / Chapter 1.3.3 --- Mass spectrometry --- p.9 / Chapter 1.4 --- Matrix assisted laser desorption/ ionization (MALDI) --- p.10 / Chapter 1.4.1 --- Laser desorption --- p.10 / Chapter 1.4.2 --- Matrix-assisted laser desorption / ionization (MALDI) --- p.11 / Chapter 1.5 --- MALDI-TOFMS analysis of polymers --- p.14 / Chapter 1.6 --- Outline of the present work --- p.16 / Chapter Chapter two --- Experimental and Instrumentation / Chapter 2.1 --- Matrix-assisted laser desorption/ ionization Time of flight Mass Spectrometry (MALDI-TOFMS) --- p.18 / Chapter 2.2 --- Delayed extraction --- p.20 / Chapter 2.3 --- Time of flight mass spectrometry (TOFMS) --- p.20 / Chapter 2.3.1 --- Linear time-of-flight mass spectrometry --- p.20 / Chapter 2.3.2 --- Reflectron --- p.21 / Chapter 2.4 --- Instrumentation --- p.23 / Chapter 2.4.1 --- Laser system --- p.24 / Chapter 2.4.2 --- Ion source --- p.26 / Chapter 2.4.3 --- Ion deflection --- p.26 / Chapter 2.4.4 --- Detection --- p.27 / Chapter 2.4.5 --- Reflector --- p.27 / Chapter 2.4.6 --- Data acquisition --- p.29 / Chapter 2.5 --- Experimental --- p.29 / Chapter 2.5.1 --- Sample preparation --- p.29 / Chapter 2.5.2 --- Calibration --- p.33 / Chapter 2.6 --- Data analysis --- p.33 / Chapter Chapter three --- Use of ammonium fluoride as co-matrix / Chapter 3.1 --- Introduction --- p.35 / Chapter 3.2 --- Results and discussion --- p.37 / Chapter 3.2.1 --- Effect of co-matrix --- p.45 / Chapter 3.2.2 --- Effect of sample preparation --- p.49 / Chapter 3.2.3 --- Analysis of dispersed dextran --- p.52 / Chapter 3.3 --- Conclusion --- p.55 / Chapter Chapter four --- Effect of sample preparation / Chapter 4.1 --- Introduction --- p.57 / Chapter 4.2 --- Experimental --- p.57 / Chapter 4.2.1 --- Sample preparation --- p.57 / Chapter 4.3 --- Results and discussion --- p.59 / Chapter 4.4 --- Conclusion --- p.71 / Chapter Chapter five --- Development of liquid matrix systems / Chapter 5.1 --- Introduction --- p.73 / Chapter 5.2 --- Experimental --- p.75 / Chapter 5.2.1 --- Sample preparation --- p.75 / Chapter 5.3 --- Results and discussion --- p.76 / Chapter 5.3.1 --- Formulation of matrix solutions --- p.76 / Chapter 5.3.2 --- Use of liquid matrix system --- p.87 / Chapter 5.3.3 --- Analysis of dispersed dextran --- p.90 / Chapter 5.4 --- Conclusion --- p.93 / Chapter Chapter six --- Conclusion / Chapter 6.1 --- Conclusion --- p.95 / References --- p.98 / Appendix / Appendix 1 Chemical structure of matrices / Appendix 2 Chemical structure of solubilizing agents / Appendix 3 Chemical structure of liquid supports / Appendix 4 Chemical structure of additives

Outcrops of late Quaternary deposits along the north–east coast of Mallorca were examined, and a high resolution chronological framework established using optically stimulated luminescence of quartz and feldspar grains. Coastal sections at Es Barrancar and Cala Mata record a complex succession of alluvial fan deposition with a minor aeolian component, mainly deposited during the last two glacial cycles. For the last ~200ka different orbital configurations appear to have produced a series of subtly different climatic scenarios that resulted in great variations in the regional availability of moisture. In turn, each of these climatic scenarios set in motion a distinct set of sedimentary processes, which imprinted themselves upon the character of fluvial system response recorded in the alluvial archives on Mallorca. Within the resulting complex of sediments were units of fluvially reworked aeolianite which, although truncated in places, were traceable laterally along wide sections of the sea front outcrops of both fan systems. These archives yielded 47 new OSL and pIRIR290 ages which suggest a number of previously unrecognised periods of enhanced fluvial activity. Luminescence ages identify significant ephemeral fluvial activity taking place during MIS 6, MIS 5 sub-stages d/c, b/a, and across the MIS 5/4 boundary. Another major phase of reworking corresponds with the middle part of MIS 3, and continued sporadically into the Last Glacial Maximum. These fluvial reworking events have been interpreted as having taken place during cold arid climatic intervals, when vegetation was at a minimum, precipitation was low and displayed a much higher degree of seasonality, enhancing the effects of runoff.

O óxido de alumínio foi um dos primeiros compostos investigados, com vista a detectar e medir a radiação por meio da termoluminescência (TL). Comumente referido como \"alumina\", o óxido de alumínio tem características interessantes para o desenvolvimento de materiais para a dosimetria. Seu número atômico efetivo é intermediário entre o do osso e do tecido mole do corpo. Pode ser transformado em material termoluminescente pela inserção de elementos químicos em sua estrutura cristalina. Além da TL, a alumina pode apresentar luminescência opticamente estimulada (OSL), fenômeno que também pode ser usado para determinar a dose de radiação. Neste estudo, dois métodos foram investigados para inserir íons metálicos na alumina. O primeiro método foi baseado na capacidade de adsorção da alumina e o segundo denominado método da coprecipitação foi baseado na formação simultânea de compostos insolúveis. As amostras obtidas por adsorção de íons Cu2+ e Mn2+ não mostraram resultados satisfatórios. No entanto, as pastilhas de óxido de alumínio impurificado com Tm3+ via coprecipitação mostraram sinais de TL e OSL. Foi verificado também que a alumina eletrofundida disponível comercialmente é um material que apresenta resposta TL e OSL. Este material que contém diversos íons metálicos em sua estrutura foi transformado em pastilhas por sinterização com vidro. As curvas da resposta TL em função da temperatura e da resposta TL e OSL em função da dose foram determinadas. Os resultados obtidos indicam que estudos mais aprofundados das pastilhas desenvolvidas podem melhorar suas características para que sejam aplicadas em dosimetria. / The aluminum oxide was one of the former compounds investigated with a view to detecting and measuring radiation by means of the thermoluminescence (TL). Commonly referred to as \"alumina\", aluminum oxide has interesting features for the development of materials for dosimetry. Its effective atomic number has an intermediate value between the bone and soft tissue of the body. It can be transformed into TL material by the insertion of chemical elements in its crystal structure. In addition to the TL, the alumina can provide optically stimulated luminescence (OSL) which can also be used to determine the radiation dose. In this study, two methods were investigated in order to insert metal ions in alumina. The first method was based on the adsorption capacity of alumina and the second named coprecipitation method was based on the simultaneous formation of insoluble compounds. The samples obtained by adsorption of Cu2+ and Mn2+ ions did not show satisfactory results. However, the aluminum oxide impurified with Tm3+ by coprecipitation showed TL and OSL signals. It was also found that the commercially available electrofused alumina is a material that exhibits TL and OSL. This material that contains various metal ions in its structure was made into pellets by sintering with glass. The TL response curves as a function of temperature and the TL and OSL responses as a function of the dose were determined. The obtained results indicate that further studies of the developed pellets can improve the characteristics in order to be applied in dosimetry.

Viruses are obligate intracellular pathogens. Therefore, their successful replication, at every stage from attachment to assembly and egress, is dependent on host cell functions. The host cell in turn engages mechanisms to counteract virus replication. As a result, viruses have evolved mechanisms to evade these counteracting measures as well as ways to reshape the cellular environment into one that’s favourable for successful replication. Systematic studies offer a platform for unravelling virus-cell interactions and in particular can address three important aspects 1) increase our understanding of basic biology of the virus, 2) identify and characterise novel cellular functions 3) provide important leads for novel targets for antiviral therapy. In this study, I investigated two aspects of virus host interaction; the role of microRNAs (miRNAs) in virus infection and the role of interferon inducible genes in virus infection. Human cytomegalovirus (HCMV) is a β herpes virus that infects humans. HCMV maintains a persistent lifelong infection in the host involving a cycle of latency and reactivation. Infection of healthy individuals with HCMV results in relatively minor symptoms. In contrast, infection of individuals with a compromised immune system, as in the case of organ transplant recipients and AIDS patients, can cause significant morbidity and mortality. In common with other herpes viruses, HCMV expresses multiple small regulatory RNAs called miRNAs. HCMV encodes at least 14 miRNAs. Identifying the targets of these miRNAs will help us understand their functional importance during infection. Recently, a biochemical technique called Cross-Linking, Ligation and Sequencing of Hybrids (CLASH), was developed by Tollervey and colleagues, representing the most advanced systematic technique for the identification of miRNA targets. We adapted this approach to identify high confidence miRNA targets during HCMV infection. However, the protocol was sub-optimal and presented us with technical challenges. Although high quality data sets were not generated, the work was crucial for the establishment of the system which is now generating promising data. Virus-cell interactions can also be elucidated by probing for host factors that are important for virus replication. Type I interferon is a highly effective inhibitor of HCMV replication. Treatment of cells with interferon results in up regulation of multiple effectors known as interferon stimulated genes (ISGs). How these genes block HCMV replication is poorly understood. A library of more than 380 ISG expressing lentiviruses was screened to determine the effects of individual ISGs on HCMV replication. The screen was performed in primary human fibroblast cells and a glioblastoma cell line called U373s. Multiple inhibitory ISGs were identified including well characterised ISGs such as cGAS, STAT2, NOD2, DDX60 and HPSE as well as novel candidates TXNIP, ELF1, FAM46C, MT1H and CHMP5. Five ISGs were identified as HCMV replication enhancers including previously published ISGs BST2 and IFITM1 and novel enhancers ODC1, BCL3 and IL28RA. siRNA screens against top hits demonstrated that STAT2, CPT1A and cGAS are dominant inhibitory factors during HCMV infection and knockdown of these genes can partially rescue HCMV replication following interferon treatment. Finally, using a corresponding rhesus ISG library we show that rhesus SAMHD1 effectively inhibits HCMV replication while human SAMHD1 has no effect, suggesting that HCMV expresses a species-specific inhibitor of SAMHD1. This study defines interferon stimulated pathways important for HCMV replication and identifies multiple novel host factors that both restrict and enhance HCMV replication. These studies demonstrate the effectiveness of using systematic approaches for the identification of novel host virus interactions.

O óxido de alumínio foi um dos primeiros compostos investigados, com vista a detectar e medir a radiação por meio da termoluminescência (TL). Comumente referido como \"alumina\", o óxido de alumínio tem características interessantes para o desenvolvimento de materiais para a dosimetria. Seu número atômico efetivo é intermediário entre o do osso e do tecido mole do corpo. Pode ser transformado em material termoluminescente pela inserção de elementos químicos em sua estrutura cristalina. Além da TL, a alumina pode apresentar luminescência opticamente estimulada (OSL), fenômeno que também pode ser usado para determinar a dose de radiação. Neste estudo, dois métodos foram investigados para inserir íons metálicos na alumina. O primeiro método foi baseado na capacidade de adsorção da alumina e o segundo denominado método da coprecipitação foi baseado na formação simultânea de compostos insolúveis. As amostras obtidas por adsorção de íons Cu2+ e Mn2+ não mostraram resultados satisfatórios. No entanto, as pastilhas de óxido de alumínio impurificado com Tm3+ via coprecipitação mostraram sinais de TL e OSL. Foi verificado também que a alumina eletrofundida disponível comercialmente é um material que apresenta resposta TL e OSL. Este material que contém diversos íons metálicos em sua estrutura foi transformado em pastilhas por sinterização com vidro. As curvas da resposta TL em função da temperatura e da resposta TL e OSL em função da dose foram determinadas. Os resultados obtidos indicam que estudos mais aprofundados das pastilhas desenvolvidas podem melhorar suas características para que sejam aplicadas em dosimetria. / The aluminum oxide was one of the former compounds investigated with a view to detecting and measuring radiation by means of the thermoluminescence (TL). Commonly referred to as \"alumina\", aluminum oxide has interesting features for the development of materials for dosimetry. Its effective atomic number has an intermediate value between the bone and soft tissue of the body. It can be transformed into TL material by the insertion of chemical elements in its crystal structure. In addition to the TL, the alumina can provide optically stimulated luminescence (OSL) which can also be used to determine the radiation dose. In this study, two methods were investigated in order to insert metal ions in alumina. The first method was based on the adsorption capacity of alumina and the second named coprecipitation method was based on the simultaneous formation of insoluble compounds. The samples obtained by adsorption of Cu2+ and Mn2+ ions did not show satisfactory results. However, the aluminum oxide impurified with Tm3+ by coprecipitation showed TL and OSL signals. It was also found that the commercially available electrofused alumina is a material that exhibits TL and OSL. This material that contains various metal ions in its structure was made into pellets by sintering with glass. The TL response curves as a function of temperature and the TL and OSL responses as a function of the dose were determined. The obtained results indicate that further studies of the developed pellets can improve the characteristics in order to be applied in dosimetry.

A luminescência opticamente estimulada (OSL) é a luminescência emitida por um material, isolante ou semicondutor, durante exposição à luz e que foi previamente exposto à radiação ionizante. Portanto, depende da quantidade de cargas armadilhadas na estrutura do material, o que por sua vez depende da dose de radiação absorvida pela amostra. Dessa forma, a busca por novos materiais para serem utilizados como detectores de radiação envolve a criação de defeitos que atuem como armadilhas e/ou centros luminescentes. Recentemente, as interações entre os plásmons de nanopartículas metálicas e centros luminescentes têm sido utilizadas para aumentar a intensidade luminescente emitida por diversos materiais. Nesse trabalho, foi investigada a possibilidade de aplicação das propriedades plasmônicas de nanoestruturas de prata e ouro, no aumento da emissão OSL. Para isso, foram testados como dosímetros OSL, compósitos de cloreto de sódio contendo nano e micropartículas de prata; compósitos de óxido de zinco contendo nanopartículas de ouro e prata; e amostras de cloreto de sódio depositado sobre filmes de nanopartículas de prata e ouro. As amostras foram caracterizadas por diversas técnicas como espectroscopia UV-Vis, espalhamento dinâmico de luz, espectroscopia na região do infravermelho, espectroscopia de fotoluminescência, microscopia eletrônica de transmissão, microscopia de força atômica, entre outras. Foi possível verificar que a intensificação dos campos elétricos locais em torno de nanopartículas metálicas em condições de ressonância plasmônica aumenta a taxa de desarmadilhamento de elétrons durante a estimulação OSL. O acoplamento plasmônico causou aumento das taxas de decaimento radiativo e redução das taxas de decaimento não radiativo, produzindo aumento da intensidade OSL. Além disso, as interações entre as armadilhas/centros luminescentes e os plásmons variam de acordo com a distância entre as partes, e a maior intensidade OSL foi obtida para amostras em que houve um espaçamento de aproximadamente 15 nm entre o NaCl o filme de nanopartículas de prata. Portanto, é possível utilizar as propriedades plasmônicas de nanoestruturas metálicas para aumentar a intensidade da luminescência opticamente estimulada, dando origem a novos e mais sensíveis detectores e dosímetros das radiações ionizantes. / Optically stimulated luminescence (OSL) is a well-known light emission process involving light stimulation of an insulator/semi-conductor material previously exposed to ionizing radiation. The intensity of the emitted light is proportional to the ionizing radiation dose previously absorbed by the material. Developing appropriate OSL materials for radiation detection and dosimetry is based on the doping and co-doping of a host material to create defects that can act as traps and/or luminescent centers. In this context, plasmon interaction with luminescent centers from OSL materials could be a new, different, and unexplored method to achieve enhanced OSL intensity and consequently improve their sensitivity as radiation detectors. In this study, we investigated whether it is possible to use the plasmonic properties of noble metal nanoparticles to obtain plasmon-enhanced OSL. To this end, we produced samples of NaCl containing nano and microparticles; composites of ZnO containing silver and gold nanoparticles; as well as samples of NaCl deposited over films of gold and silver nanoparticles. Each sample has been tested as a radiation detector by means of optically stimulated luminescence, in addition to having their materials properties analyzed by UV-Vis absorption spectroscopy, dynamic light scattering, transmission electron microscopy (TEM), atomic force microscopy, and Fourier Transform Infrared spectroscopy (FTIR). We discovered that the electric field intensification around nanoparticles under plasmon resonance conditions enhances the excitation rate of trapped electrons. The plasmon coupling during the emission process increases the radiative and diminishes the non-radiative decay rates, leading to enhanced OSL intensities. Furthermore, the interaction between traps/luminescent centers and plasmons is highly dependent on the distance between them, and the maximum OSL intensity was observed for samples with 15 nm spacing between the NaCl and the silver nanoparticle films. Therefore, it is possible to use the plasmon properties of metal nanostructures to increase OSL, giving rise to new and more sensitive ionizing radiation detectors and dosimeters.