• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 26
  • 24
  • 7
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • Tagged with
  • 79
  • 20
  • 18
  • 9
  • 9
  • 8
  • 8
  • 8
  • 7
  • 6
  • 6
  • 6
  • 6
  • 6
  • 6
  • 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.
1

Estudo da união adesiva entre cimentos resinosos e ligas a base de níquel-cromo, em funçao da aplicação de primers adesivos metálicos / Bonding strength between resin cements and niquel-chromium alloys related to the use of adhesive metal primers

Lisboa, Marcio Vieira 04 July 2005 (has links)
A força de adesão entre resinas e ligas de metais básicos resulta do embricamento mecânico entre a superfície do metal e a resina e da interação química entre óxidos presentes na superfície dos metais e monômeros adesivos das resinas compostas. A literatura, entretanto, mostra que ainda persistem algumas dúvidas sobre a interação entre os diversos tipos de sistemas adesivos e metais básicos, por isso, essa pesquisa visa: verificar se a presença do Be na composição de ligas a base de Ni-Cr influencia a união metal básico/resina; comparar dois cimentos resinosos adesivos nessa função e verificar a influência da utilização de condicionadores (primers) adesivos metálicos para ligas nobres sobre essa união. Após 2500 termociclos, foram realizados testes de resistência à tração em 160 corpos-de-prova, que consistiam de dois discos de Ni-Cr-Be (Verabond – Aalba Dental Inc., Cordelia, CA-USA) com 6 mm de diâmetro e 2 mm de espessura cimentados entre si, e dois discos de Ni-Cr (Durabond - Odonto Comercial Importadora Ltda, São Paulo, SP), com as mesmas dimensões, cimentados entre si. Foram utilizadas diferentes marcas comerciais de sistemas adesivos: os cimentos resinosos adesivos, Panavia F (Kuraray Co. Ltd.), Bistite II DC (Tokuyama Corp.) e os agente de união (primers adesivos metálicos), Alloy Primer (Kuraray Co. Ltd. ), Metaltite (Tokuyama Corp.) e Cesead Opaque Primer (Kuraray Co. Ltd.). Discos cimentados sem primers serviram como grupo controle. Os resultados mostraram que houve diferença estatisticamente significante entre as duas ligas (Ni-Cr-Be –24,82 ± 7,6 MPa e Ni-Cr - 22,32 ± 7,9 MPa). Já para os cimentos houve superioridade adesiva do cimento Panavia F, que obteve média de resitência adesiva de 27,49 ± 4,8 MPa, sobre o cimento Bistite II, que obteve média de resistência adesiva de 19,63 ± 8,4 MPa. Os primers utilizados não apresentaram influência positiva sobre o Panavia F já que os grupos sem primer para esse cimento obtiveram média de 28,18 ± 5,6 MPa que é equivalente a média dos outros grupos com Panavia. Entretanto, para o cimento Bistite II DC os primers Alloy Primer e Metaltite obtiveram as menores médias, 12,7 ± 7,6 MPa e 15,71 ± 4,8 MPa respectivamente, enquanto sem primer, ou com o Cesead Opaque Primer, as médias foram significantemente superiores, 24.47 ± 6 MPa e 25.70 ± 6,8 Mpa respectivamente. Diante dos resultados conclui-se que os primers adesivos metálicos não potencializaram a adesão de cimentos resinosos adesivos sobre ligas de Ni-Cr. / The bond strength for resin and basic metals comes from the interaction between oxides in the metal surface and adhesive monomers in the composite resins composition. The literature shows that still are some questions about this interaction so this research intends to: verify if the presence of Be at Ni-Cr alloy plays some influence for this union, compare two resin luting cements at this function and study the influence the use of metal primers for noble metals in this mecanism of adhesion. After 2500 thermocycles, tensile bond strength tests were loaded at 160 specimens, which consisted of two metals discs with 6 mm in diameter and 2 mm thick from a Ni-Cr-Be alloy (Verabond – Aalba Dental Inc., Cordelia, CA-USA) bonded togheter and two metal discs from a Ni-Cr alloy (Durabond - Odonto Comercial Importadora Ltda, São Paulo, SP) bonded togheter. Diferent brand adhesive systems were used: the resin cements, Panavia F (Kuraray Co. Ltd.) and Bistite II DC (Tokuyama Corp.) and the metal primers, Alloy Primer (Kuraray Co. Ltd.), Metaltite (Tokuyama Corp.) and Cesead Opaque Primer (Kuraray Co. Ltd.). Nonprimed specimens served as control group. The results indicated that there is statiscal diferences beetwen the two alloys (Ni-Cr-Be –24,82 ± 7,6 MPa e Ni-Cr - 22,32 ± 7,9 MPa). Panavia F had founded greater bond strength (27,49 ± 4,8 MPa) than Bistite DC (19,63 ± 8,4 MPa). The metal primers did not show any positive influence for the Panavia bond strength when we considere that the no primer group had 28,18 ± 5,6 MPa bond strength media which were equivalente to the others Panavia´s groups. However for the Bistite cement, the bond strength for Alloy primer and Metaltite were the lower medias, 12,7 ± 7,6 MPa and 15,71 ± 4,8 MPa respectivally, while the no primer or the Cesead Opaque Primer groups showed superior medias 24,47 ± 6 MPa and 25,70 ± 6,8 MPa respectivally. The outcome of this research shows that the metal primers used did not incresead the bond strength between resin cements and Ni-Cr alloys.
2

Estudo da união adesiva entre cimentos resinosos e ligas a base de níquel-cromo, em funçao da aplicação de primers adesivos metálicos / Bonding strength between resin cements and niquel-chromium alloys related to the use of adhesive metal primers

Marcio Vieira Lisboa 04 July 2005 (has links)
A força de adesão entre resinas e ligas de metais básicos resulta do embricamento mecânico entre a superfície do metal e a resina e da interação química entre óxidos presentes na superfície dos metais e monômeros adesivos das resinas compostas. A literatura, entretanto, mostra que ainda persistem algumas dúvidas sobre a interação entre os diversos tipos de sistemas adesivos e metais básicos, por isso, essa pesquisa visa: verificar se a presença do Be na composição de ligas a base de Ni-Cr influencia a união metal básico/resina; comparar dois cimentos resinosos adesivos nessa função e verificar a influência da utilização de condicionadores (primers) adesivos metálicos para ligas nobres sobre essa união. Após 2500 termociclos, foram realizados testes de resistência à tração em 160 corpos-de-prova, que consistiam de dois discos de Ni-Cr-Be (Verabond – Aalba Dental Inc., Cordelia, CA-USA) com 6 mm de diâmetro e 2 mm de espessura cimentados entre si, e dois discos de Ni-Cr (Durabond - Odonto Comercial Importadora Ltda, São Paulo, SP), com as mesmas dimensões, cimentados entre si. Foram utilizadas diferentes marcas comerciais de sistemas adesivos: os cimentos resinosos adesivos, Panavia F (Kuraray Co. Ltd.), Bistite II DC (Tokuyama Corp.) e os agente de união (primers adesivos metálicos), Alloy Primer (Kuraray Co. Ltd. ), Metaltite (Tokuyama Corp.) e Cesead Opaque Primer (Kuraray Co. Ltd.). Discos cimentados sem primers serviram como grupo controle. Os resultados mostraram que houve diferença estatisticamente significante entre as duas ligas (Ni-Cr-Be –24,82 ± 7,6 MPa e Ni-Cr - 22,32 ± 7,9 MPa). Já para os cimentos houve superioridade adesiva do cimento Panavia F, que obteve média de resitência adesiva de 27,49 ± 4,8 MPa, sobre o cimento Bistite II, que obteve média de resistência adesiva de 19,63 ± 8,4 MPa. Os primers utilizados não apresentaram influência positiva sobre o Panavia F já que os grupos sem primer para esse cimento obtiveram média de 28,18 ± 5,6 MPa que é equivalente a média dos outros grupos com Panavia. Entretanto, para o cimento Bistite II DC os primers Alloy Primer e Metaltite obtiveram as menores médias, 12,7 ± 7,6 MPa e 15,71 ± 4,8 MPa respectivamente, enquanto sem primer, ou com o Cesead Opaque Primer, as médias foram significantemente superiores, 24.47 ± 6 MPa e 25.70 ± 6,8 Mpa respectivamente. Diante dos resultados conclui-se que os primers adesivos metálicos não potencializaram a adesão de cimentos resinosos adesivos sobre ligas de Ni-Cr. / The bond strength for resin and basic metals comes from the interaction between oxides in the metal surface and adhesive monomers in the composite resins composition. The literature shows that still are some questions about this interaction so this research intends to: verify if the presence of Be at Ni-Cr alloy plays some influence for this union, compare two resin luting cements at this function and study the influence the use of metal primers for noble metals in this mecanism of adhesion. After 2500 thermocycles, tensile bond strength tests were loaded at 160 specimens, which consisted of two metals discs with 6 mm in diameter and 2 mm thick from a Ni-Cr-Be alloy (Verabond – Aalba Dental Inc., Cordelia, CA-USA) bonded togheter and two metal discs from a Ni-Cr alloy (Durabond - Odonto Comercial Importadora Ltda, São Paulo, SP) bonded togheter. Diferent brand adhesive systems were used: the resin cements, Panavia F (Kuraray Co. Ltd.) and Bistite II DC (Tokuyama Corp.) and the metal primers, Alloy Primer (Kuraray Co. Ltd.), Metaltite (Tokuyama Corp.) and Cesead Opaque Primer (Kuraray Co. Ltd.). Nonprimed specimens served as control group. The results indicated that there is statiscal diferences beetwen the two alloys (Ni-Cr-Be –24,82 ± 7,6 MPa e Ni-Cr - 22,32 ± 7,9 MPa). Panavia F had founded greater bond strength (27,49 ± 4,8 MPa) than Bistite DC (19,63 ± 8,4 MPa). The metal primers did not show any positive influence for the Panavia bond strength when we considere that the no primer group had 28,18 ± 5,6 MPa bond strength media which were equivalente to the others Panavia´s groups. However for the Bistite cement, the bond strength for Alloy primer and Metaltite were the lower medias, 12,7 ± 7,6 MPa and 15,71 ± 4,8 MPa respectivally, while the no primer or the Cesead Opaque Primer groups showed superior medias 24,47 ± 6 MPa and 25,70 ± 6,8 MPa respectivally. The outcome of this research shows that the metal primers used did not incresead the bond strength between resin cements and Ni-Cr alloys.
3

Impact behaviour of automotive multi-layer paint systems

Rumzan, Ismael Hassen Aniff January 1999 (has links)
No description available.
4

Protein-protein interaction specificity of immunity proteins for DNase colicins

Li, Wei January 1999 (has links)
No description available.
5

Prospecção e transferibilidade de marcadores est-ssr usados para análises filogenéticas em poa annua l. / Prospecting and transferability of be- ssr markers used for phylogenetic analyzes in Poa annua L.

Valente, Daine Valente January 2016 (has links)
Submitted by Francine Silva (francine.silva@unipampa.edu.br) on 2016-06-23T14:11:43Z No. of bitstreams: 1 Dissertação Daiane Valente.pdf: 1062508 bytes, checksum: c859e0c99def78cdd42b20b323c13691 (MD5) / Approved for entry into archive by Vanessa Dias (vanessa.dias@unipampa.edu.br) on 2016-06-25T21:25:13Z (GMT) No. of bitstreams: 1 Dissertação Daiane Valente.pdf: 1062508 bytes, checksum: c859e0c99def78cdd42b20b323c13691 (MD5) / Made available in DSpace on 2016-06-25T21:25:13Z (GMT). No. of bitstreams: 1 Dissertação Daiane Valente.pdf: 1062508 bytes, checksum: c859e0c99def78cdd42b20b323c13691 (MD5) Previous issue date: 2016 / Poa annua L. é a única espécie invasora de plantas com flores que obteve sucesso reprodutivo na Antártica, constituindo uma ameaça para as espécies nativas desse ecossistema. A hipótese da origem e colonização dessa gramínea nesse ambiente extremo é a de que as plantas pioneiras teriam vindo da Polônia, porém não é descartada a possibilidade de mútiplos eventos de introdução e diferentes fontes de distribuição. A disponibilidade de dados de sequências expressas (EST) tem facilitado o desenvolvimento de marcadores microssatélites (SSR) que podem ser utilizados como ferramentas para estudos populacionais em diferentes níveis, fluxo gênico, níveis de parentesco e informações sobre padrões filogeográficos. O objetivo desse trabalho foi desenvolver marcadores microssatélites a partir de sequências de regiões expressas da família Poaceae, testar o potencial de transferência em P. annua e utilizar esses marcadores para análise filogeográfica de P. annua, a fim de esclarecer a origem e colonização dessa espécie na Antártica. A prospecção de marcadores microssatélites foi desenvolvida com ferramentas de bioinformática, através de análises in sílico SSR em banco de dados EST para família Poaceae, disponíveis no Genbank (NCBI). Foram utilizados os programas CAP3 e SSRLocator para prospecção dos marcadores microssatélites. Uma pesquisa de Termos Gene Ontology (GO) foi realizada no banco de dados de sequências ESTs para avaliar associações entre locus SSR e processos biológicos, componentes celulares e função molecular de genes conhecidos, utilizando os programas Blast2GO e Revigo. O teste de transferência dos primers e análise molecular de P. annua foram conduzidos através da Reação em Cadeia da Polimerase (PCR). Foram prospectadas uma lista de 568 pares de primers, destes foram sintetizados 28 marcadores microssatélites para a transferência em P. annua. 68% dos marcadores EST-SSR tiveram potencial de transferência para esta espécie. A análise sugere que as amostras da Antártica são diferentes das amostras do Chile, Brasil, Irlanda e Argentina. Além disso, foram encontrados 613 transcritos divididos em 302 famílias gênicas. Com esta análise, foi possível desenvolver ferramentas moleculares para a análise genética com P. annua e outras espécies de gramíneas, mapear os motivos mais frequentes e funções dos genes em cada locus SSR, e sugerir que os diásporos de P. annua encontrados na Antártica podem ter vindos de fontes distintas das populações da America do Sul. / Poa annua L. is the only invasive species of flowering plants that reached reproductive success in Antarctica, posing a threat to native species of this ecosystem.The hypothesis of the origin and colonization of grass in this extreme environment is the pioneer plants would have come from Poland, but it is not ruled out event of multiple introduction and different sources of distribution. Recent increase in the availability of expressed sequence data (EST) has facilitated the development of microsatellite markers (SSR) can be used as tools for population studies at different levels, gene flow, relationship of levels and patterns phylogeographical information. The objective of this study was to develop microsatellite markers from expressed sequence regions of the Poaceae family, test the potential transfer in P. annua and use these markers for phylogeographic analysis of P. annua in order to clarify the origin and colonization of this species in Antarctica. The prospect of microsatellite markers was developed with bioinformatics tools, through an analysis in silico SSR in EST database to Poaceae family, available in Genbank (NCBI). Were used the CAP3 and SSRLocator programs for prospecting of microsatellite markers. A Search terms Gene Ontology (GO) were performed in ESTs sequences database to evaluate associations between SSR locus and biological processes, cellular components and molecular function of known genes, using the Blast2GO and Revigo programs. The transfer test of primers and molecular analysis of P. annua was conducted by Polymerase Chain Reaction (PCR). Were prospected a list of 568 primer pairs, these were synthesized 28 microsatellite markers for the transfer in P. annua. 68% of EST-SSR markers have potential transfer for this species. The analysis suggests that the samples from Antarctica are different from samples from Chile, Brazil, Argentina and Ireland. In addition, they found 613 transcripts divided into 302 genic families. With this analysis, it was possible to develop molecular tools for genetic analysis with P. annua and other grass species, mapping the most frequent motifs and functions of genes in each SSR locus, and suggest that the introduction of P. annua found in Antarctica may have come from sources other than South American populations.
6

Design and development of oligonucleotide probes for novel fungal polyketide synthase genes

Nicholson, Thomas Peter January 2000 (has links)
No description available.
7

Detection of human papillomavirus : a study of normal cells, cervical intraepithelial neoplasia and cancer of the uterine cervix

Evander, Magnus January 1991 (has links)
Human papillomavirus (HPV) infections of the genital tract are now recognized to be among the most prevalent sexually transmitted diseases and also a contributing factor to some cancers of the lower genital tract of women and men. Presence of HPV in a clinical specimen is confined to detection of the HPV genome by DNA hybridization techniques. In this thesis, the commonly used DNA hybridization techniques Southern blot and filter in situ hybridization (FISH), were first used for detection of genital HPV infection. In order to increase and simplify the detection of HPV in clinical specimens a more sensitive technique, the polymerase chain reaction (PCR) was subsequently utilized. For type-specific amplificaiton of HPV 6, 16, 18 and 33 by PCR, oligonucleotide primers located in the E6 and E7 regions of the HPV genome were selected. They were found to specifically amplify the four types. To be able to amplify a broad spectrum of genital HPV types, general primers located in the E7 and El region of the HPV genome, were designed and evaluated. They were found to amplify a wide range of genital HPV types. To further increase the sensitivity and specificity, a two-step PCR using general primers, was assembled and evaluated against a one-step PCR on cervical scrapes from young women in a population-based study. The two-step PCR increased the sensitivity about three-fold compared to the one-step PCR. By Southern blot and FISH, 46% of women with abnormal Papanicolaou (Pap) smears were shown to carry HPV DNA. Of the women analysed by Southern blot, 39 % harboured HPV DNA and 25 % proved HPV 16 positive. Of the samples analysed with FISH, 27 % contained HPV DNA, compared to 11 % of samples from a group of reference women with normal cytology. With the Southern blot technique, HPV DNA was detected in 66% of women with cervical intraepithelial neoplasia grade III (CIN III) lesions. Fifty-four percent of the women with CIN III lesions were positive for HPV 16 DNA. By type-specific PCR, 12 out of 13 women with cervical squamous carcinoma were shown to carry HPV 16 and/or 18. Among women with adenosquamous carcinoma of the cervix, HPV 18 was the most prevalent type (26%) but HPV 16 was also found in a proportion of the women(15 %). Nine of 13 premenopausal cases with cervical adenocarcinoma were HPV positive compared to only 2 of 13 postmenopausal cases (p&lt; 0.015). HPV 16 DNA was detected in 48%of women with cervical intraepithelial neoplasia (CIN), by the use of type-specific PCR. Three different groups of women with normal cytology were studied. Among women attending a family planning clinic in Kenya, 19% were shown to carry HPV virus, by the use of general primers. HPV 16 was found in 5.2% of these women and HPV 18 in 3.9%. In anothergroup of women, attending the gynecological department in Umeå, HPV 16 DNA was detected in 21 % by type-specific PCR. However, if consideration was taken to the medical status of the women, only 10% of women without any medical history were HPV 16 DNA positive, versus 54% of women with diseases and women with a relative progesterone dominance. Finally, by use of a two-step PCR using general primers, 20% of young women from Umeå taking part in a population-based study were demonstrated to carry HPV DNA. The most prevalent types were HPV 6 (2.0%) and HPV 16(2.7%). Among the women in this study with normal cytology, 19%were HPV positive. / <p>Diss. (sammanfattning) Umeå : Umeå universitet, 1991, härtill 9 uppsatser.</p> / digitalisering@umu
8

Návrh a testování multiplex-PCR primerů pro detekci původců bakteriální skvrnitosti rajčete / Design and testing of multiplex-PCR primers for detection of bacterial spot of tomato

STEHLÍKOVÁ, Dagmar January 2015 (has links)
The subject of this work is to develop multiplex-PCR assay for specific detection of plant pathogenic bacteria of Xanthomonas genus causing bacterial spot of tomato. PCR primers for detection of groups A (X. euvesicatoria), B (X. vesicatoria), C (X. perforans) and D (X. gardneri) were developed based on the DNA sequences obtained by sequencing and from the GenBank database (NCBI). Four primer pairs - Xe_shotgun_104, Xe_shotgun_1819, Xv_atpD_403, Xp_efP_202 were designed and subsequently thoroughly tested and optimized for parallel detection of these bacteria. Specificity of the primers was tested on a large complex of bacterial strains pathogenic to tomato and related crops. Following the protocol described above X. vesicatoria, X. euvesicatoria, X. perforans and X. gardneri can be quickly and reliably identified in a single multiplex-PCR assay.
9

Seleção in silico de sequências de dna espécie-específicas de Leishmania

Oliveira, Fernanda Muller de [UNESP] 09 December 2015 (has links) (PDF)
Made available in DSpace on 2016-09-27T13:40:00Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-12-09. Added 1 bitstream(s) on 2016-09-27T13:45:09Z : No. of bitstreams: 1 000870495.pdf: 1494495 bytes, checksum: 3b9f9ca073de023b7bdc8087537f82c7 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Leishmaniasis, a disease caused by the protozoan Leishmania spp. is expanding in the world and affects millions of people annually, reaching 98 countries in tropical and subtropical regions, representing an important public health problem. Subspecies Leishmania and Viannia, represented by at least 22 species, are responsible for the three most common clinical manifestations of the disease in humans. Routinely, in endemic areas, serological diagnosis are employed. However, other parasitological and/or molecular techniques have high sensitivity to identify the genus Leishmania. The publication of Leishmania genomes have provided a better understanding of their composition and molecular markers to identify protozoan species and intra-specific variations, however some species are still underdiagnosed. However, the differentiation of Leishmania species in clinical samples still has limitations. Thus, in order to find the solution for this issue, we sought to design specific sequences for different species of Leishmania deposited in trypanosomatid genomic database, carrying out an in silico assay for verification of the selected sequences. The information generated in this study will constitute an interesting diagnostic platform, after proper validation with clinical samples
10

Seleção in silico de sequências de dna espécie-específicas de Leishmania /

Oliveira, Fernanda Muller de. January 2015 (has links)
Resumo:eishmaniose, doença causada pelo protozoário Leishmania spp., encontra-se em franca expansão no mundo e acomete milhões de pessoas anualmente, atingindo 98 países de regiões tropicais e subtropicais, representando um importante problema de Saúde Pública. As subespécies Leishmania e Viannia apresentam, no mínimo, 22 espécies, que são responsáveis pelas três manifestações clínicas mais comuns da doença para humanos. Rotineiramente, em áreas endêmicas, o diagnóstico laboratorial sorológico é empregado, porém, outras técnicas parasitológicas e/ou moleculares tem alta sensibilidade para identificação do gênero Leishmania. A publicação de genomas de Leishmania proporcionou um maior conhecimento de regiões e marcadores para identificação de espécies do protozoário e variações intra-específicas, todavia algumas espécies ainda tem sido subdiagnosticadas. Entretanto, a diferenciação das espécies de Leishmania em amostras clínicas ainda apresenta limitações. Assim, com o intuito de auxiliar na solução desta questão, buscamos sequências específicas para diferentes espécies de Leishmania depositadas em banco de dados genômicos de tripanossomatídeos e realizamos um ensaio in silico para verificação das nossas sequências. As informações geradas neste trabalho serão úteis numa plataforma diagnóstica para que sejam validadas com amostras clínicas. / Abstract:Leishmaniasis, a disease caused by the protozoan Leishmania spp. is expanding in the world and affects millions of people annually, reaching 98 countries in tropical and subtropical regions, representing an important public health problem. Subspecies Leishmania and Viannia, represented by at least 22 species, are responsible for the three most common clinical manifestations of the disease in humans. Routinely, in endemic areas, serological diagnosis are employed. However, other parasitological and/or molecular techniques have high sensitivity to identify the genus Leishmania. The publication of Leishmania genomes have provided a better understanding of their composition and molecular markers to identify protozoan species and intra-specific variations, however some species are still underdiagnosed. However, the differentiation of Leishmania species in clinical samples still has limitations. Thus, in order to find the solution for this issue, we sought to design specific sequences for different species of Leishmania deposited in trypanosomatid genomic database, carrying out an in silico assay for verification of the selected sequences. The information generated in this study will constitute an interesting diagnostic platform, after proper validation with clinical samples / Orientador:Caris Maroni Nunes / Banca:Flávia Lombardi Lopes / Banca:Vania Lúcia Ribeiro da Matta / Banca:Rodrigo Martins Soares / Banca: Valéria Marçal Felix de Lima / Doutor

Page generated in 0.0312 seconds