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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.
11

Estratégias para indução de competência de oócitos bovinos com atividade da enzima glicose 6-fosfato desidrogenase

Salviano, Mauricio Barbosa January 2014 (has links)
O objetivo deste trabalho foi modificar os procedimentos da maturação in vitro (MIV) para induzir a competência de oócitos bovinos com intensa atividade da enzima glicose 6-fosfato desidrogenase (G6PDH), determinada pelo emprego do corante vital Azul de Cresil Brilhante (BCB). Foram realizados dois experimentos; no primeiro trabalho foi realizada a MIV de oócitos após a identificação da atividade da G6PDH, empregando-se a seguinte proporção: competentes (sem atividade enzimática)/não competentes - 10:01, respectivamente. Os resultados revelaram um efeito negativo dos oócitos não competentes sobre a capacidade dos competentes em realizarem a MIV, a FIV e a CIV. Os resultados sugerem que para aumentar a produção de embriões deve-se realizar a MIV de oócitos competentes e não competentes, separadamente. O objetivo do segundo experimento foi verificar se a prolongação do tempo de MIV (30h) afetaria as taxas de MIV, FIV e CIV obtidas a partir de oócitos não competentes. Os oócitos não competentes não foram afetados, positiva ou negativamente, pelo prolongamento do tempo de MIV, no entanto, os oócitos competentes sofreram decréscimo na capacidade de serem fecundados e desenvolverem-se até o estágio de blastocistos. Podemos concluir que as modificações realizadas no procedimento da MIV não foram capazes de induzir competência em oócitos com intensa atividade da enzima G6PDH. / The present work aimed modify the in vitro maturation (IVM) procedure to induce competence of bovine oocytes with high glucose 6-phosphate dehydrogenase (G6PDH) activity. Two experiments were carried out; the first non-competent oocytes (with high enzymatic activity) were matured with competent oocyte (lower G6PDH activity) on proportion of 1:10, respectively. The second experiment aimed observe the effect of prolonged IVM (from 24 to 30h) on the cleavage and development rates in oocytes with higher enzymatic activity. Our data showed that oocytes with lower enzymatic activity did not induce competence of higher G6PDH activity oocyte. However, we observed a negatively effect on the cleavage and development rates on oocytes competent, then, to increase the number of embryos in vitro produced we need to mature oocytes competent and non-competent separately. In the second experiment, the non-competent gametes submitted to prolonged IVM were not affected, however, competent oocytes were negatively affect by prolonged IVM. We can concluded that the IVM modifications did not able to induce the competence in the oocytes with high G6PDH activity.
12

Desenvolvimento e expressão gênica em oócitos bovinos imaturos selecionados por Azul Cresil Brilhante / Development and gene expression of immature bovine oocytes selected by Brilliant Cresyl Blue

Mota, Gustavo Bruno 28 February 2008 (has links)
Made available in DSpace on 2015-03-26T13:54:39Z (GMT). No. of bitstreams: 1 texto completo.pdf: 272543 bytes, checksum: 2dcf69c50e38fd64e6faa78f1f0d9c46 (MD5) Previous issue date: 2008-02-28 / The in vitro embryo production (IVP) efficiency has been limited by oocyte developmental competence and in vitro culture conditions. The use of Brilliant Cresyl Blue (BCB) dye has been described as an alternative method for selection of better quality oocytes. The aim of this work was to evaluate the selection of immature oocytes by BCB dye and the expression of transcripts involved in the transition from genome-maternal. In the first step, a total of 998 immature oocytes was distributed into: G1- Control: oocytes sent directly to in vitro maturation, not exposed to the dye; G2- Control incubation (mPBS): oocytes exposed to mPBS solution without BCB for 1h; G3- BCB+: oocytes exposed to mPBS added of BCB and positively stained; G4- BCB-: oocytes exposed to mPBS with BCB and colorless. Oocytes of each treatment were matured, fertilized and presumptive zygotes were cultured in vitro for eight days. The rates of cleavage were obtained at 48h after the beginning of the culture and the rates of blastocysts at eight days post fertilization. The cleavage rates between G1 and G3 were similar, but higher than G2 and G4, the ones which similar. The oocytes in G3 showed blastocyst rate similar to the G1 and G2, but higher than G4. In another step, total RNA was extracted from three pools of 12 immature oocytes obtained from each group and used to generate cDNA. The relative abundance of MATER and Zar-1 transcripts was analyzed by Real Time PCR. No difference was found on relative expression for MATER and Zar-1 among groups. In conclusion, the conventional morphologic selection associated to the selection by BCB dye can be used as method of selection of immature oocyte, distinguishing two oocytes populations with different development competence, however this double selection did not select more competent oocytes when used only the conventional morphologic assessment. Moreover, the dye is not able to select oocytes with different patterns of expression transcripts MATER and Zar-1. / A eficiência da produção in vitro de embriões (PIV) tem sido limitada pelas condições de cultivo in vitro e baixa competência dos oócitos utilizados na maturação in vitro. A utilização do corante Azul Cresil Brilhante (ACB) associado à seleção morfológica convencional, tem sido descrita como uma alternativa para seleção de oócitos de melhor qualidade. Objetivou-se neste trabalho avaliar o uso do ACB como método de seleção de oócitos imaturos bovinos, utilizando como parâmetros de avaliação o desenvolvimento embrionário e a expressão de genes envolvidos na transição do genoma materno-zigótica. Na primeira etapa, um total de 998 oócitos foram distribuídos em 4 grupos: G1-Controle: oócitos submetidos à maturação sem exposição ao corante ; G2- Controle de incubação (mPBS): oócitos mantidos em mPBS por 1h a temperatura de 38,5º C em ar atmosférico; G3-ACB+: oócitos mantidos em mPBS adicionado de ACB, nas mesmas condições de G2, que apresentaram ao final da incubação citoplasma corado; G4- ACB-: oócitos mantidos em mPBS adicionado de ACB nas mesma condições de G2, que ao final da incubação apresentaram citoplasma incolor. Os oócitos de cada tratamento foram maturados, fertilizados e os possíveis zigotos cultivados in vitro por oito dias. As taxas de clivagem foram obtidas 48h após inicio do cultivo e as taxas de blastocistos oito dias após fecundação. As taxas de clivagem de G1 e G3 foram semelhantes, no entanto foram maiores que G2 e G4, as quais semelhantes. Os oócitos G3 apresentaram taxas de blastocisto semelhantes ao G1 e G2, mas foram maiores do que o G4. Na segunda etapa, o RNA total foi extraído de três pools de 12 oócitos imaturos obtidos dos mesmos tratamentos acima descritos e usados para gerar cDNA. A abundância relativa dos transcritos MATER e Zar-1 foi analisada por Real Time-PCR. Não foi encontrada diferença na expressão relativa dos transcritos MATER e Zar-1 entre os tratamentos. Em conclusão, à seleção morfológica convencional associada à seleção pelo corante ACB pode ser usada como método de seleção de oócitos imaturos, distinguindo duas populações de oócitos com diferente competência de desenvolvimento, no entanto esta dupla seleção não selecionou oócitos mais competentes quando utilizado unicamente o critério morfológico convencional de seleção. Além disso, o corante não foi capaz de selecionar oócitos com diferente padrão na expressão dos transcritos MATER e Zar-1.
13

Estratégias para indução de competência de oócitos bovinos com atividade da enzima glicose 6-fosfato desidrogenase

Salviano, Mauricio Barbosa January 2014 (has links)
O objetivo deste trabalho foi modificar os procedimentos da maturação in vitro (MIV) para induzir a competência de oócitos bovinos com intensa atividade da enzima glicose 6-fosfato desidrogenase (G6PDH), determinada pelo emprego do corante vital Azul de Cresil Brilhante (BCB). Foram realizados dois experimentos; no primeiro trabalho foi realizada a MIV de oócitos após a identificação da atividade da G6PDH, empregando-se a seguinte proporção: competentes (sem atividade enzimática)/não competentes - 10:01, respectivamente. Os resultados revelaram um efeito negativo dos oócitos não competentes sobre a capacidade dos competentes em realizarem a MIV, a FIV e a CIV. Os resultados sugerem que para aumentar a produção de embriões deve-se realizar a MIV de oócitos competentes e não competentes, separadamente. O objetivo do segundo experimento foi verificar se a prolongação do tempo de MIV (30h) afetaria as taxas de MIV, FIV e CIV obtidas a partir de oócitos não competentes. Os oócitos não competentes não foram afetados, positiva ou negativamente, pelo prolongamento do tempo de MIV, no entanto, os oócitos competentes sofreram decréscimo na capacidade de serem fecundados e desenvolverem-se até o estágio de blastocistos. Podemos concluir que as modificações realizadas no procedimento da MIV não foram capazes de induzir competência em oócitos com intensa atividade da enzima G6PDH. / The present work aimed modify the in vitro maturation (IVM) procedure to induce competence of bovine oocytes with high glucose 6-phosphate dehydrogenase (G6PDH) activity. Two experiments were carried out; the first non-competent oocytes (with high enzymatic activity) were matured with competent oocyte (lower G6PDH activity) on proportion of 1:10, respectively. The second experiment aimed observe the effect of prolonged IVM (from 24 to 30h) on the cleavage and development rates in oocytes with higher enzymatic activity. Our data showed that oocytes with lower enzymatic activity did not induce competence of higher G6PDH activity oocyte. However, we observed a negatively effect on the cleavage and development rates on oocytes competent, then, to increase the number of embryos in vitro produced we need to mature oocytes competent and non-competent separately. In the second experiment, the non-competent gametes submitted to prolonged IVM were not affected, however, competent oocytes were negatively affect by prolonged IVM. We can concluded that the IVM modifications did not able to induce the competence in the oocytes with high G6PDH activity.
14

Estratégias para indução de competência de oócitos bovinos com atividade da enzima glicose 6-fosfato desidrogenase

Salviano, Mauricio Barbosa January 2014 (has links)
O objetivo deste trabalho foi modificar os procedimentos da maturação in vitro (MIV) para induzir a competência de oócitos bovinos com intensa atividade da enzima glicose 6-fosfato desidrogenase (G6PDH), determinada pelo emprego do corante vital Azul de Cresil Brilhante (BCB). Foram realizados dois experimentos; no primeiro trabalho foi realizada a MIV de oócitos após a identificação da atividade da G6PDH, empregando-se a seguinte proporção: competentes (sem atividade enzimática)/não competentes - 10:01, respectivamente. Os resultados revelaram um efeito negativo dos oócitos não competentes sobre a capacidade dos competentes em realizarem a MIV, a FIV e a CIV. Os resultados sugerem que para aumentar a produção de embriões deve-se realizar a MIV de oócitos competentes e não competentes, separadamente. O objetivo do segundo experimento foi verificar se a prolongação do tempo de MIV (30h) afetaria as taxas de MIV, FIV e CIV obtidas a partir de oócitos não competentes. Os oócitos não competentes não foram afetados, positiva ou negativamente, pelo prolongamento do tempo de MIV, no entanto, os oócitos competentes sofreram decréscimo na capacidade de serem fecundados e desenvolverem-se até o estágio de blastocistos. Podemos concluir que as modificações realizadas no procedimento da MIV não foram capazes de induzir competência em oócitos com intensa atividade da enzima G6PDH. / The present work aimed modify the in vitro maturation (IVM) procedure to induce competence of bovine oocytes with high glucose 6-phosphate dehydrogenase (G6PDH) activity. Two experiments were carried out; the first non-competent oocytes (with high enzymatic activity) were matured with competent oocyte (lower G6PDH activity) on proportion of 1:10, respectively. The second experiment aimed observe the effect of prolonged IVM (from 24 to 30h) on the cleavage and development rates in oocytes with higher enzymatic activity. Our data showed that oocytes with lower enzymatic activity did not induce competence of higher G6PDH activity oocyte. However, we observed a negatively effect on the cleavage and development rates on oocytes competent, then, to increase the number of embryos in vitro produced we need to mature oocytes competent and non-competent separately. In the second experiment, the non-competent gametes submitted to prolonged IVM were not affected, however, competent oocytes were negatively affect by prolonged IVM. We can concluded that the IVM modifications did not able to induce the competence in the oocytes with high G6PDH activity.
15

Expressão gênica em complexos cumulus-oócito bovinos selecionados pela atividade da glicose-6-fosfato desidrogenase / Genetic expression in bovine cumulus oocyte complexes selected by activity of glucose-6-phosphate dehydrogenase

Lopes, Eliana Franco January 2013 (has links)
O objetivo desse trabalho foi avaliar a expressão de genes envolvidos no transporte de monocarboxilatos (Mct1, Mct2, Mct3 e Mct4) e de genes específicos da oogênese (Bmp15, Gdf9 e Has2) em complexos cumulus-oócito (CCOs) selecionados pelo teste BCB. Após seleção morfológica com base no grau de compactação das células do cumulus (CCs) e no grau de homogeneidade do citoplasma, os CCOs foram corados com 26 μM BCB (azul cresil brilhante) por 90 min e divididos em dois grupos: BCB+, que apresentavam o ooplasma corado de azul, e BCB-, com ooplasma não corado. Foram utilizados dois grupos controles não expostos ao BCB: o grupo holding foi submetido às mesmas condições que os grupos corados e o outro grupo controle foi diretamente submetido à maturação in vitro (MIV), após a seleção morfológica dos CCOs. A expressão gênica relativa foi determinada por RT-PCR em CCOs coletados antes e ao final da maturação. A expressão também foi avaliada, separadamente, em oócitos desnudos (ODs) e células do cumulus (CCs) antes e após a maturação. A análise dos transcritos demonstrou que houve aumento significativo (p < 0,05) na expressão relativa de Gdf9 e Bmp15 nos grupos BCB+, BCB- e holding antes da MIV, enquanto Has2 teve aumento significativo (p < 0,01) após a MIV apenas no grupo controle. Os outros genes analisados (Mct1, Mct2 e Mct4) mantiveram-se estáveis durante a maturação. O aumento na abundância relativa de alguns transcritos durante a MIV pode ser atribuído as condições de incubações durante o teste BCB. Nossos resultados demonstraram, pela primeira vez, a expressão de Mct1, 2 e 4 em CCOs bovinos. Enquanto o mRNA de Mct1 e Mct4 estava presente em ODs e em CC, o Mct2 foi detectado somente em CCs. Não detectamos a expressão de transcritos de Mct3 em CCOs. As diferenças na expressão dessas três isoformas sugerem um papel único para esses transportadores durante a maturação. / The aim of this study was to determine the relative expression of genes involved in transport of monocarboxylates (Mct1, Mct2, Mct3 e Mct4) and oogenesis specific genes (Bmp15, Gdf9 and Has2) in immature and mature bovine cumulus-oocyte complexes (COC) after selection by BCB. Immature COCs underwent morphological selection and were stained with 26 mM BCB for 90 min. Based on ooplasm staining, oocytes were distributed in two groups BCB+ (blue color) and BCB- (non-stained). The holding control group was exposed to the same incubation conditions as stained COCs, but without BCB. Control group was submitted to in vitro maturation (IVM) immediately after morphological selection. mRNA expression was investigated by RT-PCR in COCs before and after IVM. No relationship was observed in the relative expression of Has2, Gdf9, Bmp15 or Mct1, 2 and 4 transcripts between BCB- and BCB+ COCs. Transcripts analysis showed that Gdf9 and Bmp15 in BCB+, BCB- and holding groups were upregulated (p < 0.05) before IVM, while Has2 was up-regulated (p < 0.01) after IVM in the control group. Others genes remained stable during maturation (Mct1, 2 and 4). The increase in relative abundance of some transcripts during IVM may be attributed to incubation conditions during the BCB test. Our results showed, for the first time, Mct1, 2 and 4 expression in bovine COCs. Mct1 and Mct4 transcripts were present in denuded oocytes and cumulus cell, while Mct2 was detected only in cumulus cells. These differences between the three isoforms in localization suggest unique roles for each in monocarboxylate transport during maturation.
16

New Carbon-Silicon Carbide Composite Board Material for High Density and High Reliability Packaging

Kumbhat, Nitesh 23 June 2005 (has links)
Current board technologies are inherently performance-limited (FR-4) or cost-prohibitive (Al2O3/AlN). Next-generation high-density packaging applications would necessitate a new base substrate material to achieve ultra-fine pitch solder-joint reliability and multiple layers of fine-line wiring at low cost. The NEMI 2000 roadmap defines the need for 4-8 layers of 5-10 m wiring for future system boards. The 2003 ITRS roadmap calls for organic substrates with less than 100-m area-array pitch in the package or board by year 2010. Solder-joint reliability at such fine-pitch is a matter of concern for the industry. Use of underfills reduces thermal stresses but increases cost and, in addition, their dispensing becomes increasingly more complicated with the shorter gaps required for future interconnects. Therefore, there is a pronounced need to evaluate board materials with CTE close to that of Si for reliable flip-chip on board without underfill. Recently, a novel manufacturing process (using polymeric precursor) has been demonstrated to yield boards that have the advantages of organic boards in terms of large-area processability and machinability at potentially low-cost while retaining the high stiffness (~250 GPa) and Si-matched CTE (~2.5 ppm/㩠of ceramics. This work reports the evaluation of novel SiC-based ceramic composite board material for ultra-fine pitch solder-joint reliability without underfill and multilayer support. FE models were generated to model the behavior of flip-chips assembled without underfill and subjected to accelerated thermal cycling. These models were used to calculate solder-joint strains which have a strong direct influence on fatigue life of the solder. Multilayer structures were also simulated for thermal shock testing so as to assess via strains for microvia reliability. Via-pad misregistration was derived from the models and compared for different boards. Experiments were done to assemble flip-chips on boards without underfill followed by thermal shock testing so as to get the number of cycles to failure. To assess microvia reliability, 2 layer structures containing vias of different diameters were fabricated and subjected to thermal cycling. Via-pad misalignment was also studied experimentally. Modeling and experimental results were corroborated so as to evaluate thermomechanical suitability of C-SiC for high-density packaging requirements.
17

Adhesive Wafer Bonding for Microelectronic and Microelectromechanical Systems

Frank, Niklaus January 2002 (has links)
<p>Semiconductor wafer bonding has been a subject of interestfor many years and a wide variety of wafer bonding techniqueshave been reported in literature. In adhesive wafer bondingorganic and inorganic adhesives are used as intermediatebonding material. The main advantages of adhesive wafer bondingare the relatively low bonding temperatures, the lack of needfor an electric voltage or current, the compatibility withstandard CMOS wafers and the ability to join practically anykind of wafer materials. Adhesive wafer bonding requires nospecial wafer surface treatmentssuch as planarisation.Structures and particles at the wafer surfaces can be toleratedand compensated for some extent by the adhesive material.Adhesive wafer bonding is a comparably simple, robust andlowcost bonding process. In this thesis, adhesive wafer bondingtechniques with different polymer adhesives have beendeveloped. The relevant bonding parameters needed to achievehigh quality and high yield wafer bonds have been investigated.A selective adhesive wafer bonding process has also beendeveloped that allows localised bonding on lithographicallydefined wafer areas.</p><p>Adhesive wafer bonding has been utilised in variousapplication areas. A novel CMOS compatible film, device andmembrane transfer bonding technique has been developed. Thistechnique allows the integration of standard CMOS circuits withthin film transducers that can consist of practically any typeof crystalline or noncrystalline high performance material(e.g. monocrystalline silicon, gallium arsenide,indium-phosphide, etc.). The transferred transducers or filmscan be thinner than 0.3 µm. The feature sizes of thetransferred transducers can be below 1.5 µm and theelectrical via contacts between the transducers and the newsubstrate wafer can be as small as 3x3 µm2. Teststructures for temperature coefficient of resistancemeasurements of semiconductor materials have been fabricatedusing device transfer bonding. Arrays of polycrystallinesilicon bolometers for use in uncooled infrared focal planearrays have been fabricated using membrane transfer bonding.The bolometers consist of free-hanging membrane structures thatare thermally isolated from the substrate wafer. Thepolycrystalline silicon bolometers are fabricated on asacrificial substrate wafer. Subsequently, they are transferredand integrated on a new substrate wafer using membrane transferbonding. With the same membrane transfer bonding technique,arrays of torsional monocrystalline silicon micromirrors havebeen fabricated. The mirrors have a size of 16x16 µm2 anda thickness of 0.34 µm. The advantages of micromirrorsmade of monocrystalline silicon are their flatness, uniformityand mechanical stability. Selective adhesive wafer bonding hasbeen used to fabricate very shallow cavities that can beutilised in packaging and component protection applications. Anew concept is proposed that allows hermetic sealing ofcavities fabricated using adhesive wafer bonding. Furthermore,microfluidic devices, channels and passive valves for use inmicro total analysis systems are presented.</p><p>Adhesive wafer bonding is a generic CMOS compatible bondingtechnique that can be used for fabrication and integration ofvarious microsystems such as infrared focal plane arrays,spatial light modulators, microoptical systems, laser systems,MEMS, RF-MEMS and stacking of active electronic films forthree-dimensional high-density integration of electroniccircuits. Adhesive wafer bonding can also be used forfabrication of microcavities in packaging applications, forwafer-level stacking of integrated circuit chips (e.g. memorychips) and for fabrication of microfluidic systems.</p>
18

Conception et réalisation d'antennes reconfigurables à base de MEMS en intégration hétérogène 3D pour systèmes de communication millimétriques

Sarrazin, Tristan 05 April 2013 (has links) (PDF)
Les travaux présentés dans cette thèse sont une contribution à l'étude d'antennes reconfigurables à base de MEMS en intégration hétérogène 3D pour les systèmes de communication millimétriques. Ces travaux de thèse s'inscrivent dans le cadre d'un projet ANR nommé SIPCOM (Intégration hétérogène 3D (System-In-Package) pour objets communicants en gamme millimétrique), qui concerne l'intégration hétérogène d'un microsystème intelligent communicant à 60GHz. Au cours de ce manuscrit, nous proposons la réalisation d'antennes sur membrane selon 3 technologies. Dans un premier temps, une nouvelle technologie simple et bas coût basée sur un empilement de FR4 et de Pyralux ainsi qu'un nouveau concept d'antenne patch sur membrane alimentée par un guide d'onde intégré via une fente de couplage sont présentés. Dans un second temps, ce nouveau concept d'antenne a été adapté afin de pouvoir l'intégrer au module SiP réalisé en technologie Silicium / BCB. Enfin, la troisième technologie basée sur des substrats de quartz permet de démontrer la faisabilité d'une antenne à balayage électronique pour laquelle chaque excitateur est intégré dans le design d'un déphaseur à base de MEMS permettant de s'affranchir des interconnexions par bonding entre le déphaseur et la partie antennaire.
19

Adhesive Wafer Bonding for Microelectronic and Microelectromechanical Systems

Frank, Niklaus January 2002 (has links)
Semiconductor wafer bonding has been a subject of interestfor many years and a wide variety of wafer bonding techniqueshave been reported in literature. In adhesive wafer bondingorganic and inorganic adhesives are used as intermediatebonding material. The main advantages of adhesive wafer bondingare the relatively low bonding temperatures, the lack of needfor an electric voltage or current, the compatibility withstandard CMOS wafers and the ability to join practically anykind of wafer materials. Adhesive wafer bonding requires nospecial wafer surface treatmentssuch as planarisation.Structures and particles at the wafer surfaces can be toleratedand compensated for some extent by the adhesive material.Adhesive wafer bonding is a comparably simple, robust andlowcost bonding process. In this thesis, adhesive wafer bondingtechniques with different polymer adhesives have beendeveloped. The relevant bonding parameters needed to achievehigh quality and high yield wafer bonds have been investigated.A selective adhesive wafer bonding process has also beendeveloped that allows localised bonding on lithographicallydefined wafer areas. Adhesive wafer bonding has been utilised in variousapplication areas. A novel CMOS compatible film, device andmembrane transfer bonding technique has been developed. Thistechnique allows the integration of standard CMOS circuits withthin film transducers that can consist of practically any typeof crystalline or noncrystalline high performance material(e.g. monocrystalline silicon, gallium arsenide,indium-phosphide, etc.). The transferred transducers or filmscan be thinner than 0.3 µm. The feature sizes of thetransferred transducers can be below 1.5 µm and theelectrical via contacts between the transducers and the newsubstrate wafer can be as small as 3x3 µm2. Teststructures for temperature coefficient of resistancemeasurements of semiconductor materials have been fabricatedusing device transfer bonding. Arrays of polycrystallinesilicon bolometers for use in uncooled infrared focal planearrays have been fabricated using membrane transfer bonding.The bolometers consist of free-hanging membrane structures thatare thermally isolated from the substrate wafer. Thepolycrystalline silicon bolometers are fabricated on asacrificial substrate wafer. Subsequently, they are transferredand integrated on a new substrate wafer using membrane transferbonding. With the same membrane transfer bonding technique,arrays of torsional monocrystalline silicon micromirrors havebeen fabricated. The mirrors have a size of 16x16 µm2 anda thickness of 0.34 µm. The advantages of micromirrorsmade of monocrystalline silicon are their flatness, uniformityand mechanical stability. Selective adhesive wafer bonding hasbeen used to fabricate very shallow cavities that can beutilised in packaging and component protection applications. Anew concept is proposed that allows hermetic sealing ofcavities fabricated using adhesive wafer bonding. Furthermore,microfluidic devices, channels and passive valves for use inmicro total analysis systems are presented. Adhesive wafer bonding is a generic CMOS compatible bondingtechnique that can be used for fabrication and integration ofvarious microsystems such as infrared focal plane arrays,spatial light modulators, microoptical systems, laser systems,MEMS, RF-MEMS and stacking of active electronic films forthree-dimensional high-density integration of electroniccircuits. Adhesive wafer bonding can also be used forfabrication of microcavities in packaging applications, forwafer-level stacking of integrated circuit chips (e.g. memorychips) and for fabrication of microfluidic systems.
20

Expressão gênica em complexos cumulus-oócito bovinos selecionados pela atividade da glicose-6-fosfato desidrogenase / Genetic expression in bovine cumulus oocyte complexes selected by activity of glucose-6-phosphate dehydrogenase

Lopes, Eliana Franco January 2013 (has links)
O objetivo desse trabalho foi avaliar a expressão de genes envolvidos no transporte de monocarboxilatos (Mct1, Mct2, Mct3 e Mct4) e de genes específicos da oogênese (Bmp15, Gdf9 e Has2) em complexos cumulus-oócito (CCOs) selecionados pelo teste BCB. Após seleção morfológica com base no grau de compactação das células do cumulus (CCs) e no grau de homogeneidade do citoplasma, os CCOs foram corados com 26 μM BCB (azul cresil brilhante) por 90 min e divididos em dois grupos: BCB+, que apresentavam o ooplasma corado de azul, e BCB-, com ooplasma não corado. Foram utilizados dois grupos controles não expostos ao BCB: o grupo holding foi submetido às mesmas condições que os grupos corados e o outro grupo controle foi diretamente submetido à maturação in vitro (MIV), após a seleção morfológica dos CCOs. A expressão gênica relativa foi determinada por RT-PCR em CCOs coletados antes e ao final da maturação. A expressão também foi avaliada, separadamente, em oócitos desnudos (ODs) e células do cumulus (CCs) antes e após a maturação. A análise dos transcritos demonstrou que houve aumento significativo (p < 0,05) na expressão relativa de Gdf9 e Bmp15 nos grupos BCB+, BCB- e holding antes da MIV, enquanto Has2 teve aumento significativo (p < 0,01) após a MIV apenas no grupo controle. Os outros genes analisados (Mct1, Mct2 e Mct4) mantiveram-se estáveis durante a maturação. O aumento na abundância relativa de alguns transcritos durante a MIV pode ser atribuído as condições de incubações durante o teste BCB. Nossos resultados demonstraram, pela primeira vez, a expressão de Mct1, 2 e 4 em CCOs bovinos. Enquanto o mRNA de Mct1 e Mct4 estava presente em ODs e em CC, o Mct2 foi detectado somente em CCs. Não detectamos a expressão de transcritos de Mct3 em CCOs. As diferenças na expressão dessas três isoformas sugerem um papel único para esses transportadores durante a maturação. / The aim of this study was to determine the relative expression of genes involved in transport of monocarboxylates (Mct1, Mct2, Mct3 e Mct4) and oogenesis specific genes (Bmp15, Gdf9 and Has2) in immature and mature bovine cumulus-oocyte complexes (COC) after selection by BCB. Immature COCs underwent morphological selection and were stained with 26 mM BCB for 90 min. Based on ooplasm staining, oocytes were distributed in two groups BCB+ (blue color) and BCB- (non-stained). The holding control group was exposed to the same incubation conditions as stained COCs, but without BCB. Control group was submitted to in vitro maturation (IVM) immediately after morphological selection. mRNA expression was investigated by RT-PCR in COCs before and after IVM. No relationship was observed in the relative expression of Has2, Gdf9, Bmp15 or Mct1, 2 and 4 transcripts between BCB- and BCB+ COCs. Transcripts analysis showed that Gdf9 and Bmp15 in BCB+, BCB- and holding groups were upregulated (p < 0.05) before IVM, while Has2 was up-regulated (p < 0.01) after IVM in the control group. Others genes remained stable during maturation (Mct1, 2 and 4). The increase in relative abundance of some transcripts during IVM may be attributed to incubation conditions during the BCB test. Our results showed, for the first time, Mct1, 2 and 4 expression in bovine COCs. Mct1 and Mct4 transcripts were present in denuded oocytes and cumulus cell, while Mct2 was detected only in cumulus cells. These differences between the three isoforms in localization suggest unique roles for each in monocarboxylate transport during maturation.

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