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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
301

Very low field magnetic resonance imaging

Herreros, Quentin 21 November 2013 (has links) (PDF)
The aim of this thesis is to perform Magnetic Resonance Imaging at very low field (from 1 mT to 10 mT). A new kind of sensor called "mixed sensor" has been used to achieve a good detectivity at low frequencies. Combining a superconducting loop and a giant magnetoresistance, those detectors have a competitive equivalent field noise compared to existing devices (Tuned coils, SQUIDs and Atomic Magnetometers). They have been combined with flux transformers to increase the coupling between the sample and the sensor. A complete study has been performed to adapt it to mixed sensors and then maximize the gain. This set has been incorporated in an existing small MRI device to test its robustness in real conditions. In parallel, several MRI sequences (GE, SE, FLASH, EPI, ...) have been integrated and adapted to very low field requirements. They have been used to perform in-vivo three dimensional imaging and relaxometry studies on well known products to test their reliability. Finally, a larger setup adapted for full-head imaging has been designed and built to perform images on a larger working volume.
302

Stock improvement of giant freshwater prawn (Macrobrachium rosenbergii) in Vietnam: Experimental evaluations of crossbreeding,the impact of domestication on genetic diversity and candidate genes

Thanh Nguyen Unknown Date (has links)
Aquaculture plays an important role in economic development and food security in many countries in the world. World aquaculture production in 2006 was 51.7 million tonnes with an estimated value of US$ 78.8 billion (FAO, 2009). World production will need to increase however by 30-40 million tonnes from its current production level by 2030 to meet growing global demand for fish. In this context, aquaculture in Vietnam has developed rapidly over the past decade and the fisheries sector ranked fourth in terms of export value in 2008 (Vietnamnet, 2008). Total fisheries production in Vietnam in 2007 was 4.149 million tonnes, of which fisheries production from catch and aquaculture were 2.064 and 2.085 million tonnes, respectively. A variety of aquatic species are cultured in Vietnam, but shrimps (mainly Black Tiger shrimp Penaeus monodon, and Pacific white shrimp Litopenaeus vannamei) and ‘tra’ or ‘basa’ catfish are the most common species used in aquaculture. The giant freshwater prawn (GFP), Macrobrachium rosenbergii, is one of the most important crustacean species in inland aquaculture in many countries across the world where this species is either native or exotic. GFP is suitable for culture in a variety of farming systems, including monoculture or polyculture in ponds, pens, and integrated or rotational rice-prawn culture models. The GFP industry worldwide relies totally on wild or unimproved stocks, a practice that threatens the long-term sustainability of GFP farming due to low productivity and vulnerability of farmed stocks to disease. The current status of GFP aquaculture highlights the need for initiation of a systematic stock improvement program for the species to improve economically important traits. Large-scale selective breeding programs have been instigated for some finfish, salmonids and GIFT tilapia for example, and some selective breeding trials have been conducted on crustacean species, namely marine penaeid shrimp and freshwater crayfish. Examples of selective breeding programs on aquatic species have demonstrated that significant genetic gains can be achieved for growth rates with gains of around 10-20% per generation. While a selective breeding program is an option for GFP stock improvement, an alternative approach to improving GFP productivity, potentially with more immediate effect and one that is less expensive, is crossbreeding which may produce heterosis or hybrid vigour in crossbred offspring. Therefore, a crossbreeding strategy was trialed in the current study as a starting point for a stock improvement program for the GFP industry in Vietnam. The current study assessed the growth performance of three GFP strains (two wild Vietnamese strains from the Dong Nai and Mekong rivers, and a single domesticated Hawaiian strain) and their reciprocal crosses in a complete 3x3 diallel cross, i.e. three purebred and six crossbred strains. The diallel cross was carried out over two consecutive generations (G1 and G2). Juveniles for the experiments were produced using single-pair matings. Juveniles from each strain combination were stocked into three replicate hapas for 15 weeks. Growth data (body weight, carapace length, standard length) from the G1 and G2 were pooled for all subsequent analyses as there was no effect of generation on growth traits. Results showed that the Hawaiian strain performed best among purebred strains, and crosses with the Dong Nai or Mekong strains as dams and the Hawaiian strain as sires grew significantly faster than did the purebred Dong Nai or Mekong strains. These results suggest potential for heterosis among some crosses. Growth data were analyzed in depth by partitioning the strain combination (cross) effect into three components: strain additive genetic effects, heterotic effects, and strain reciprocal effects. Strain additive genetic and reciprocal effects were significant sources of variation for all growth traits measured. Strain additive genetic effects were highest for the Hawaiian strain and lowest for the Mekong strain for all growth traits. Reciprocal effects influenced negatively on growth rate of crosses with the Hawaiian (H) strain as dams and the Dong Nai (D) or Mekong (M) as sires compared with their reciprocal crosses (DH and MH). Heterotic effects for all growth traits were small and not significantly different from zero (P > 0.05). These results indicate that a crossbreeding approach based on the strains evaluated here provides only limited potential for improving growth rates based simply on heterotic outcomes and that a likely more productive option would be to trial artificial selection on a diverse synthetic stock. The current study also employed genetic markers (microsatellites) to characterize levels and patterns of genetic diversity in three purebred strains of GFP that originated from the diallel cross above. All three purebred strains showed relative high levels of genetic diversity in terms of allele number and individual heterozygosity across the six marker loci screened. Levels of genetic diversity present in the three purebred strains combined into a single stock were compared with that from a combination of three wild river stocks to assess the impact of domestication on genetic diversity of a ‘synthetic’ population. Results demonstrated that there was no significant loss of genetic diversity in the three purebred strains combined compared with a reference set containing the three wild populations. Therefore, a synthetic population formed from these purebred strains successfully captured the majority of genetic variation present in the wild broodstock. This synthetic population provides a potential stock for a future selective breeding program for GFP in Vietnam. The current study was also the first attempt to identify single nucleotide polymorphisms (SNPs) in key growth genes in GFP. Two key candidate genes were targeted, actin and crustacean hyperglycemic hormone (CHH), that are potentially linked to growth performance in GFP. The study screened SNPs in GFP females only, because growth performance of GFP males is influenced strongly by social rank. The study identified four SNPs in intron 3 of the CHH gene that were significantly correlated with individual body weight at harvest, while no SNPs detected in the actin gene were associated with growth traits in GFP. This finding however, needs to be confirmed using larger sample sizes and other GFP lines. The current study has produced important basic knowledge relevant to implementation of an effective stock improvement program for GFP in Vietnam. Results indicate that a selective breeding strategy rather than a crossbreeding approach is likely to be the best strategy for improving GFP culture stocks in Vietnam. In addition, the study demonstrates that application of modern molecular genetic technologies can be efficient in developing a genetically diverse, synthetic population for stock improvement and for identifying potential markers correlated with important commercial traits in GFP. Integration of DNA techniques with traditional breeding practices can facilitate GFP stock improvement in Vietnam and accelerate the industry development when improved lines are available. Some limitations of the current study and recommendations for further work are discussed.
303

Mechanisms of the foreign body response to protein and monocyte repellant tetraglyme films /

Mayorga, Luisa E., January 2008 (has links)
Thesis (Ph. D.)--University of Washington, 2008. / Vita. Includes bibliographical references (leaves 298-310).
304

Capteur de courant à Magnéto-Impédance Géante (GMI) souple et portatif / Flexible and portable GMI current sensor

Nabias, Julie 14 February 2018 (has links)
La Magnéto-Impédance Géante (GMI pour Giant Magneto-Impedance) présente un certain nombre d’avantages, tels la haute sensibilité, la haute résolution de détection, la large bande passante et la flexibilité de l’élément sensible qui rendent cette technologie très prometteuse pour la réalisation de capteurs de courant flexibles, sans contact, capables de mesurer à la fois les courants continus (DC) et alternatifs (AC).Ce travail de thèse vise à explorer la faisabilité d’un capteur de courant flexible à base de GMI, en portant une attention particulière sur l’impact des paramètres d’influence qui conditionnent largement les solutions de mise en œuvre du capteur.Les effets de la température et des contraintes mécaniques de flexion et de torsion, qui s’appliquent dans un environnement de mesure réel, sont caractérisés en prenant en compte les grandeurs intrinsèques du fil nécessaires à la réalisation d’un capteur industriel. L’impact de la mise en œuvre et du conditionnement électronique vis-à-vis de ces grandeurs d’influence est aussi étudié. Les effets des perturbations magnétiques externes et de l’excentration du conducteur sous test dans la boucle de mesure sont quantifiés et une solution de blindage est proposée. Enfin, le prototype de capteur obtenu à l’issue de ces travaux est présenté, ainsi que ses performances, en dégageant les pistes d’optimisation et d’amélioration. / The GMI effect displays several advantages, such as high sensitivity, high detection resolution and bandwidth, and mechanical flexibility. These advantages predispose this technology to the implementation of flexible contactless current sensors measuring both DC and AC currents.This thesis work aims at exploring the feasibility of a flexible GMI current sensor. A particular attention to the impact of influence parameters which largely condition the design solutions of the sensor has been paid.The effects of temperature and mechanical constraints such as bending and torsion, which apply in a real measuring environment, are characterized by taking into account the intrinsic features which are necessary to the design of the sensor. The impact of the general measuring configuration and electronics are also studied. The effects of magnetic disturbances and of the position of the current-carrying conductor in the measuring loop are quantified and an adequate shielding method is proposed. Finally, the sensor prototype obtained at the end of this work is described with its performances and the possible optimization and enhancement ways.
305

Teoretický popis kolektivních excitací jader / Theoretical description of nuclear collective excitations

Repko, Anton January 2016 (has links)
Density functional theory is a preferred microscopic method for calculation of nuclear properties over the whole nuclear chart. Besides ground-state properties, which are calculated by Hartree-Fock theory, nuclear excitations can be described by means of Random Phase Approximation (RPA). The main objective of the present work is to give the RPA formalism for spherically symmetric nuclei, using the techniques of angular-momentum coupling. Various auxiliary topics, such as Hartree-Fock theory, Coulomb integral, center-of-mass corrections and pairing, are treated as well. RPA method is derived also for axially deformed nuclei. The derived formulae are then implemented in the computer code and utilized for calculation of some physical results. After thorough investigation of the precision aspects of the calculation, the following topics are treated as examples: toroidal nature of the low-energy (pygmy) part of the E1 resonance, giant resonances of various multipolarities in deformed nucleus 154Sm, and magnetic dipole (M1) transitions in deformed 50Cr. Powered by TCPDF (www.tcpdf.org)
306

[en] DEVELOPMENT AND CHARACTERIZATION OF HIGH SENSITIVITY GMI GRADIOMETER / [pt] DESENVOLVIMENTO E CARACTERIZAÇÃO DE GRADIÔMETRO GMI DE ALTA SENSIBILIDADE

PEDRO ALEJANDRO DUARTE RIVEROS 16 November 2017 (has links)
[pt] Esta dissertação tem por objetivo o desenvolvimento de um transdutor magnético em configuração gradiométrica (gradiômetro), baseado nas características de fase da impedância de amostras sensoras de Magnetoimpedância Gigante (GMI), visando à medição de campos magnéticos de baixa intensidade em ambientes desprovidos de blindagem magnética. A metodologia empregada iniciou pela medição e análise das características de fase da impedância de duas amostras sensoras GMI, em função do campo magnético externo. Na sequencia, foi idealizado o circuito eletrônico do gradiômetro, o qual é responsável por excitar os elementos sensores e apresentar uma saída em tensão, proporcional ao gradiente de campo entre eles. As principais características do protótipo desenvolvido são detalhadas ao longo do texto e as previsões teóricocomputacionais são comparadas com os resultados experimentais obtidos. Por sua vez, as principais figuras de mérito do protótipo desenvolvido são detalhadamente analisadas, tais como: sensibilidade, linearidade, resposta em frequência, densidade espectral de ruído, resolução e distorção harmônica total. Também, avalia-se a distancia ótima de separação entre os elementos sensores empregados no gradiômetro, a fim de se otimizar a relação sinal-ruído. Os resultados indicam que o gradiômetro desenvolvido apresenta uma alta resolução, elevada sensibilidade, e linearidade, banda de passagem de até 1 kHz e baixa distorção harmônica. Por meio da comparação dos resultados obtidos pelo gradiômetro com os de um magnetômetro GMI, pode-se concluir que o gradiômetro propicia significativa atenuação da interferência magnética. Dessa forma, verifica-se que o dispositivo desenvolvido contribui para a medição de campos magnéticos de baixa intensidade, em ambientes ruidosos. / [en] This dissertation aims at developing a magnetic field transducer in gradiometric configuration (gradiometer), based on the impedance phase characteristics of Giant Magnetoimpedance (GMI) sensors, focusing on the measurement of low intensity magnetic fields in unshielded enviroments. The first step of the adopted methodology was measuring and analyzing the impedance phase characteristics of GMI sensors, as a function of the external magnetic field. After that, it was idealized the electronic circuit of the gradiometer, which is responsible by exciting the sensor elements and by presenting a voltage output, proportional to the magnetic field gradient between them. The main features of the developed prototype are detailed throughout the text and the theoreticalcomputational predictions are compared with the experimental results obtained. Furthermore, the most relevant figures of merit of the developed prototype are analyzed in detail, such as sensitivity, linearity, frequency response, spectral noise density, resolution and total harmonic distortion. Besides, the optimal separation between the two sensors used in the gradiometer is analyzed, aiming at improving the signal to noise ratio. The obtained results indicate that the developed gradiometer has a high resolution, high sensitivity and linearity, passband up to 1 kHz and low harmonic distortion. Comparing the gradiometer s performance results with the ones achieved with a GMI magnetometer leads to conclude that the gradiometer attenuates considerably the magnetic interference. In this way, it can be concluded that the developed device contributes to the measurement of low intensity magnetic fields in noisy environments.
307

[en] DEVELOPMENT AND CHARACTERIZATION OF A FIELD MAGNETIC TRANSDUCER BASED ON GIANT MAGNETOIMPEDANCE EFFECT / [pt] DESENVOLVIMENTO E CARACTERIZAÇÃO DE UM TRANSDUTOR MAGNÉTICO BASEADO NO EFEITO DA MAGNETOIMPEDÂNCIA GIGANTE

FLAVIA MARIA POMPEIA CAVALCANTI 03 March 2006 (has links)
[pt] Nesta dissertação são descritos o projeto, a implementação e os testes preliminares de um protótipo de transdutor de campo magnético em tensão, baseado no fenômeno da Magnetoimpedância Gigante (MIG) e caracterizado por uma configuração geométrica inovadora. O elemento sensor e o circuito eletrônico do transdutor foram idealizados e implementados de modo a se obter a maior sensibilidade possível a campos próximos e imunidade a campos remotos. Através das medidas de caracterização do elemento sensor e do circuito, foi possível obter uma sensibilidade estimada do transdutor, sendo esta aproximadamente 12 V/Oe, a qual já é comparável à de dois dos principais sensores magnéticos existentes, o fluxgate e o sensor de efeito Hall. O transdutor desenvolvido tem por principal aplicação, nesta pesquisa, a localização de corpos estranhos magnéticos no corpo humano, baseando-se em técnica já desenvolvida e testada para sensores SQUID. Para auxiliar a interpretação dos resultados experimentais, foi criado um modelo teórico do campo magnético associado a uma agulha e do sinal de saída do transdutor associado a este campo. Medições com uma agulha retilínea foram realizadas para se avaliar o comportamento do transdutor perante este campo magnético. Apesar da elevada sensibilidade, as medidas indicaram não- linearidade e baixa imunidade a campos uniformes. Contudo, independentemente das melhorias que possam ser feitas e que já foram identificadas, o transdutor desenvolvido já tem aplicações bastante promissoras, destacando-se por seu reduzido custo de fabricação e operação. / [en] In this dissertation, it is proposed the design of a magnetic field to voltage transducer based on the Giant Magnetoimpedance phenomenon (GMI), characterized by an innovative geometric configuration. In order to attain the best near-field sensibility and far-field immunity, the transducer`s sensitive element and electronic circuit were planned and implemented. By thoroughly characterizing them it was possible to obtain an estimate of the transducer`s sensibility, which is approximately 12 V/Oe. This value is comparable to those observed in two of the most important existing magnetic sensors: the fluxgate and the Hall effect sensor. The main application of the developed transducer is the localization of magnetic foreign bodies in humans, based on a previously developed and tested SQUID sensor technique. In order to provide a better interpretation of the experimental results, a theoretical model of the magnetic field associated with a needle and of the signal it generates in the transducer was created. Measurements with a needle were performed to analyze the behavior of the prototype, which has a high sensitivity, as expected, but presents strong hysteresis, lack of linearity and low immunity to uniform fields. However, despite the improvements that can still be done and have already been identified, the developed transducer has many promising applications, and has the advantage of reduced fabrication and operation costs.
308

Estudo das percepções de estudantes da rede pública e da helmintofauna associada ao caramujo africano Achatina fulica Bowdich, 1822 (Mollusca, Gastropoda) em Barra do Piraí (RJ): subsídios para uma intervenção educativa

Pereira, Zilene Moreira January 2010 (has links)
Submitted by Anderson Silva (avargas@icict.fiocruz.br) on 2012-05-09T12:47:47Z No. of bitstreams: 1 zilene_m_pereira_ioc_ebs_0008_2010.pdf: 15520398 bytes, checksum: 493b6f7c7e7dea5020af412b5cc0cffc (MD5) / Made available in DSpace on 2012-05-09T12:47:47Z (GMT). No. of bitstreams: 1 zilene_m_pereira_ioc_ebs_0008_2010.pdf: 15520398 bytes, checksum: 493b6f7c7e7dea5020af412b5cc0cffc (MD5) Previous issue date: 2010 / Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil. / Achatina fulica, ou caramujo africano, foi introduzido no Brasil em meados da década de 1980 para ser comercializado como “escargot”. No entanto, em virtude da baixa demanda do mercado consumidor, os criadores desativaram seus plantéis, gerando fuga ou liberação intencional de exemplares que, livres no ambiente, espalharam-se rapidamente por quase todo país (24 estados mais o Distrito Federal). As “densas” populações do caramujo africano causam uma série de problemas, como a destruição de hortas e jardins, competição com a fauna nativa, além de poderem transmitir zoonoses como a angiostrongilose abdominal e a meningite eosinofílica. A exemplo do que ocorre em outras partes do país, o Município de Barra do Piraí, Estado do Rio de Janeiro, encontra-se também infestado. Visando contribuir para o enfrentamento dos danos causados por essa espécie, o presente estudo objetivou: pesquisar a helmintofauna de populações de A. fulica em alguns bairros de Barra do Piraí quanto à presença de larvas de helmintos de importância médico-veterinária; analisar as percepções relacionadas ao caramujo africano entre estudantes do Ensino Fundamental de uma escola pública estadual no referido município. A pesquisa, de abordagem qualitativa, foi realizada em duas etapas: 1) coleta de exemplares de A. fulica nos bairros Arthur Cataldi, Dorândia, Química, Boca do Mato e São João no período de fevereiro de 2008 a novembro de 2009, os quais foram analisados no Laboratório de Malacologia do Instituto Oswaldo Cruz/Fiocruz (Referência Nacional em Malacologia Médica); 2) aplicação de 82 questionários e a realização de quatro grupos focais com alunos do Ensino Fundamental, além de observações de campo. Os resultados obtidos ao longo do trabalho “comprovam” que há uma infestação de caramujos africanos no município. A pesquisa da helmitofauna revelou que caramujos provenientes de dois dos cinco bairros analisados, quais sejam, Química e Dorândia, apresentaram o nematódeo Angiostrongylus cantonensis causador da meningite eosinofílica no homem. Além disso, também foram encontrados no município os nematódeos Strongyluris-like e Aelurostrongylus abstrusus que causam doenças em animais. Os dados referentes ao estudo das percepções revelaram que os alunos identificam a presença do caramujo africano no contexto no qual estão inseridos, e embora a maioria acredite que esse animal possa causar doenças, apenas uma minoria afirma conhecer pessoas que tiveram problemas com o caramujo. Os dados igualmente apontam para divergências entre a visão dos alunos e o conhecimento científico sobre as formas de controle de A. fulica e os tipos de agravos, em função do contato ou ingestão dessa espécie. Os laudos referentes ao exame dos moluscos e as recomendações aos órgãos municipais sobre o controle e monitoramento A. fulica já foram encaminhados à secretaria de saúde do município para que sejam tomadas as devidas providências. Da mesma forma o trabalho será disponibilizado aos professores da escola que participou desta pesquisa para que suas contribuições possam auxiliar na prática docente. Espera-se que os resultados deste trabalho possam subsidiar o desenvolvimento de ações de controle e monitoramento de A. fulica no município, bem como ações educativas em contextos formais e não formais de ensino para trabalhar com essa temática, adequadas à realidade da comunidade. / The giant African snail Achatina fulica, was introduced in Brazil in mid-1980 for commercial purposes ("escargot" farming) that were not successful. In spite of marketing efforts the demand was low since Brazilians are not used to eat terrestrial snails. Thus, farmers gave up rearing the snails and unaware of the potential negative consequences released the snails by putting them in the garbage, discarding them on waste land and the edges of highways or throwing them into the rivers. The result was a quick spread throughout most of the country (24 states plus the Federal District). The "dense" populations of A. fulica cause many of problems, such as nuisance and destruction of vegetable gardens and gardens. They may also transmit zoonosis such as abdominal angiostrongylosis and meningoencephalitis. Similarly to other municipalities in the state of Rio de Janeiro, Barra do Piraí is also infested. The present study aimed to investigate the larval helminthes of medical and veterinary importance associated with populations of A. fulica in some districts of that municipality as well as analyze the knowledge and perceptions about that snail among students in a public school. Therefore, methodological procedures were performed in two steps: 1) collecting of specimens of A. fulica from five neighborhoods from February 2008 to November 2009, which were analyzed at the Laboratory of Malacology (Instituto Oswaldo Cruz/Fiocruz), a National Center for Medical Malacology Research; 2) application of 82 questionnaires and conducting four focus groups with elementary school students, and field observations. The search for larval helminthes detected the presence of nematodes of medical-veterinary importance: Strongyluris-like, Aelurostrongylus abstrusus and Angiostrongylus cantonensis larvae (causes eosinophilic meningitis in humans) in the neighborhoods of Química and Dorândia. As for the study of the perceptions the data revealed that students identify the presence of the African snail in the context in which they live. Most of the students believe that the snail can cause disease, but a minority said that knew the health problems related to this animal or even people who had them. The data also point to differences between students' views and scientific knowledge on ways to control A. fulica and the types of injuries, depending on contact or ingestion of this species. The reports concerning the examination of snails and recommendations to the municipal authorities over the control and monitoring A. fulica have been forwarded to the secretary of health of the city for taking appropriate action. Moreover, the work will be available to school teachers who participated in this survey for their contributions to assist in teaching. It is hoped that the results of this study may support the development of control measures and monitoring of A. fulica in the county, as well as educational activities appropriate to the reality of the community.
309

Utilisation de la Magnéto-Impédance Géante pour la réalisation d'un capteur de courant / A current sensor using the Giant Magneto-Impedance effect

Zidi, Manel 18 November 2014 (has links)
Le potentiel de la GMI a été exploré pour la réalisation d'un capteur magnétique de mesure du courant électrique. Une partie notable de ce projet a été consacrée à l'investigation de l'électronique de conditionnement du capteur, notamment, l'électronique d'excitation de l'élément sensible et l'électronique de détection de la variation de la tension à ces bornes. Une nouvelle solution d'oscillateur numérique précis, stable et de haute fréquence a été proposée. Un convertisseur tension-courant basé sur la source de Howland a été associé à cet oscillateur. Pour la détection, des technologies innovantes et prometteuses, tel que le détecteur RMS-DC pour les mesures précises, ont été proposées. Un conditionnement électronique permet d'utiliser ce détecteur pour la démodulation des signaux alternatifs. Une approche originale de détecteur d'amplitude sans seuil utilisant un amplificateur limiteur a été développée. Ces technologies ont été intégrées avec succès dans un capteur de courant électrique. / A GMI current sensor was designed. This study was devoted to the investigation of the electronic conditioning of the sensor. An accurate, stable and high frequency digital oscillator was developed. A voltage-to-current converter based on the Howland source was associated to this oscillator. An innovative and promising technology for precise measurements was proposed: the RMS-DC detector. This detector was conditioned for demodulating AC signals. Also an original approach of an amplitude detector using a limiting amplifier was developed. These technologies have been successfully integrated into a GMI current sensor.
310

Expressão de recptor de estrógeno, vimentina, TGFbeta, e marcador de macrófagos em tumor ósseo de células gigantes em gatos domésticos

Dune, Ana Cláudia [UNESP] 26 February 2008 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:27:58Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-02-26Bitstream added on 2014-06-13T20:36:41Z : No. of bitstreams: 1 dune_acc_me_jabo.pdf: 415734 bytes, checksum: 508642fb7787a9fec7ba22d33d842496 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O tumor ósseo de células gigantes apresenta 3 diferentes tipos celulares, sendo duas estromais: fibroblastos neoplásicos e células mononucleares; e o terceiro tipo, células gigantes. Propôs-se que este tumor é de linhagem monócito-macrofágica e acredita-se que as células gigantes se formam por fusão de células mononucleares. Aparentemente os fibroblastos neoplásicos que expressam o fator transformador de crescimento TGFbeta1 estão envolvidos no recrutamento das células gigantes para o tumor. Com o intuito de compreender melhor a histogênese, o envolvimento do estrógeno e a expressão de receptores TGFbeta1, foi realizado este estudo em casos deste tumor em gatos domésticos. Para tanto foi utilizado o método imuno-enzimático Streptoavidina-biotina utilizando-se o anticorpo primário anti-vimentina, clone 3B4 (Dako A/s, Denmark); o anticorpo marcador de macrófago, MAC387 (Dako A/s, Denmark); o anticorpo para receptores de estrógeno, clone 15D (Dako A/s, Denmark) e o anticorpo marcador para TGFBeta1 (Santa Cruz Biotechnology). Os resultados foram analisados pela porcentagem e desvio padrão de células marcadas para cada anticorpo e permitiram concluir que: o TOCG de gatos domésticos, assim como em humanos, tem origem mesenquimal e expressa receptores de estrógeno e de TGF 1 e as células gigantes do tumor não reagem com o clone 387, marcador de células de linhagem mielomonocítica. / Giant cell tumor of bone are composed of 3 different cell types: round mononuclear stromal cells, spindle-shaped mononuclear stromal cells, and giant cells. Some authors assert giant cell could arise by fusion of mononuclear cell mielomonocytic. Aparently neoplasic fibroblast that expression TGF is involved in the recruitment of giant cells from tumor. For better understand of histogenesis, the involved of receptors estrogen and of expression of TGF receptors, achieved this study in this cases tumor in domestics cats. By using the immune-enzymatic Streptoavidin- biotin using the primary antibody anti-vimentin, clone VIM 3B4 (Dako A/s, Denmark); antibody myeloid/histocyte clone MAC 387 (Dako A/s, Denmark); antibody estrogen receptor clone 1D5 (Dako A/s, Denmark) and the antibody TGFb1 (Santa Cruz Biotechnology). The results analyzed for percent and standara deviation of marks cells for each antibody and permissive to come to a conclusion: the GCT of bone in domestic cats, like humans, has mesenchymal origin and has expression of estrogen receptors and of TGFbeta, and giants cells this tumor not react with the clone 387, mark the cells myeloidmonocyte lineage.

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