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Polimorfismo nos genes da leptina e do receptor de melatonina em búfalas (Bubalus bubalis)Zetouni, Larissa [UNESP] 25 April 2012 (has links) (PDF)
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zetouni_l_me_jabo.pdf: 337751 bytes, checksum: b21af7c1ec9b43b60d9345d076668d73 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O gene responsável pela codificação do hormônio leptina tem sido associado à produção de leite, e diversos polimorfismos encontrados nesse gene foram associados a características produtivas em bovinos. O objetivo do presente estudo foi a identificação do polimorfismo LEP-1620 (A/G) no gene bubalino da leptina e suas possíveis associações com as produções de leite, gordura, proteína e porcentagens de gordura e proteína. Foram coletadas amostras de pelo da cauda de 200 búfalas, e após a extração do DNA as amostras foram genotipadas pela técnica PCR-RFLP. Três amostras foram sequenciadas e foi encontrado um SNP na posição 70 do íntron 2 do gene da leptina, caracterizado pela substituição de um A por um G. As médias das produções mensais de leite, gordura, proteína e as porcentagens de gordura e proteína foram avaliadas em um modelo misto. Os genótipos encontrados (AA, AG, GG) foram positivamente associados às características porcentagem de gordura e de proteína (p<0,05), sendo que os animais AA apresentaram médias superiores para as características. As curvas de lactação para as características produção de leite e porcentagens de gordura e proteína apresentaram trajetórias semelhantes para os três genótipos. Esses resultados indicam que o polimorfismo LEP-1620 (A/G) pode ser utilizado futuramente como marcador molecular para as características porcentagem de gordura e proteína do leite de búfalas / The gene responsible for encoding the hormone leptin has been associated with milk production, and several polymorphisms of this gene were associated with production traits in cattle. The aim of the present study was to identify the LEP-1620 (A/G) polymorphism in the buffalo leptin gene and its possible associations with milk, fat and protein yield, and fat and protein percentages. Samples of tail hair from 200 buffalo cows were collected, and after DNA extraction the samples were genotyped by PCR-RFLP. Three samples were sequenced and an SNP was found at position 70 of intron 2 in the leptin gene, characterized by the substitution of an A for a G. The means from monthly milk, fat and protein yield and falt and protein percentages were evaluated by a mixed model. The genotypes found (AA, AG, GG) were positively associated with fat and protein percentages (p<0,005), and the AA animals showed the highest means for this traits. The lactation curves for milk yield and fat and protein percentages showed similar trajectories for the three genotypes. These results indicate that the LEP-1620 (A/G) polymorphism can be used in the future as a molecular marker for fat and protein percentages traits of buffalo cow’s milk
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Polimorfismo genÃtico da apolipoproteÃna E e avaliaÃÃo sociodemogrÃfica em pacientes com periodontite crÃnicaPatricia de Barros Teles 29 November 2013 (has links)
FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / A periodontite crÃnica inflamatÃria (PC) caracteriza-se por um processo inflamatÃrio nos tecidos de suporte dos dentes. à causada inicialmente por bactÃrias, mas sua progressÃo està relacionada à resposta individual do hospedeiro. à uma doenÃa multifatorial e complexa, na qual fatores genÃticos e ambientais interagem, promovendo e modificando a expressÃo clÃnica da doenÃa. Polimorfismos de genes envolvidos no processo inflamatÃrio tÃm sido estudados no intuito de identificar possÃveis marcadores genÃticos e elucidar diferenÃas na expressÃo de citocinas mediadoras da inflamaÃÃo. ApolipoproteÃna E (apoE) à uma proteÃna de importÃncia no metabolismo lipÃdico e està envolvida em processos fisiopatolÃgicos. O objetivo deste estudo foi investigar se hà associaÃÃo do polimorfismo do gene da apoE com a susceptibilidade à PC em indivÃduos que procuraram o serviÃo odontolÃgico da clÃnica de Periodontia da Universidade Federal do Cearà e avaliar achados sociodemogrÃficos relacionados com essa doenÃa. Foram selecionados 109 indivÃduos entre 30 e 70 anos (mÃdia = 44,5  9,64) de ambos os gÃneros e agrupados da seguinte forma: grupo controle n=53 e grupo Periodontite CrÃnica n=56. Foi extraÃdo DNA a partir de um bochecho e esfregaÃo da mucosa oral e o polimorfismo da apoE foi identificado pelo mÃtodo de PCR-RFLP (reaÃÃo de polimerase em cadeia â polimorfismo com restriÃÃo de fragmentos) e submetidos à eletroforese em gel de agarose a 5%. As distribuiÃÃes da frequÃncia alÃlica e dos genÃtipos foram avaliadas pelo teste qui-quadrado (p˂0,05). O risco associado com alelos e genÃtipos foi calculado como odds ratio (OR) com intervalo de confianÃa (IC) de 95%. Para relacionar os achados sociodemogrÃficos com a PC em indivÃduos com alelos especÃficos foi utilizada a anÃlise de regressÃo logÃstica. Os resultados da anÃlise individual do polimorfismo da apoE nÃo evidenciaram associaÃÃo dos alelos e genÃtipos com a susceptibilidade à PC. Observou-se associaÃÃo entre a doenÃa e a renda familiar mensal, de maneira que a chance de adoecer aumenta 3 vezes quando a renda diminui de mais que 3 salÃrios-mÃnimos para a renda de 1 a 3 salÃrios-mÃnimos. Ainda, hà um aumento significativo na chance de desenvolver a doenÃa em 5,1% a cada ano de vida. IndivÃduos que reportaram hipertensÃo arterial tiveram uma chance quase 2,5 vezes maior de ter a PC do que o grupo controle apesar de nÃo ter dado significado estatÃstico. Da mesma forma, foi encontrada maior chance de desenvolver a doenÃa em indivÃduos com baixo nÃvel de escolaridade (OR=3,7). O polimorfismo da apoE nÃo està associado à PC na populaÃÃo estudada. / Chronic periodontitis (CP) is characterized by an inflammation in the supporting tissues of the teeth. It is primarily caused by bacteria, but progression is associated with individual host response. CP is a complex and multifactorial disease. Genetic and environmental factors interacting can modify the clinical cause of the disease. Genetic polymorphisms have been studied to identify possible genetic markers and explain differences in the inflammatory cytokines expression. Apolipoprotein E (apoE) is an important protein in lipid metabolism and is also envolved in pathophysiological processes. The aim of this study was to investigate whether there is an association of the APOE polymorphisms with the CPÂs susceptibility in subjects that sought periodontal treatment at Dental School of Federal University of Ceara and evaluate sociodemographic status related with the disease. A sample of 109 subjects between 30 and 70 years (mean age = 44,5  9,64) were grouped into: 53 controls and 56 subjects with CP. DNA was obtained through a mouthwash and oral mucosa scraping and genotyped by PCR-RFLP method (Polimerase Chain Reaction â Restrict Fragment Length Polymorphism). Differences in the allele and genotype frequencies were assessed by Chi-squared test (p˂0.05). The risk associated with alleles and genotypes was calculated as odds ratio (OR) with 95% confidence intervals (CI). Logistic regression was used to associate sociodemographic status with CP and genotypes. No differences were observed in the apoE allelic distribution regarding control and periodontitis groups. Age and socio-economic status increase the risk for having CP, since individuals with lower socio-economic status was about 3-fold more likely to develop periodontitis (OR=3.1) and increase in age enhances the risk in 5.1% to develop disease in each year of age. Hypertension was a factor of clinic importance in development of CP, since subjects who self-reported hypertensive have 2,5-fold more likely to develop disease than individuals who not self-reported hypertension, although no statistic difference was reached. Similarly, CP was also associated with lower education level (OR=3.7). The polymorphism in the APOE gene was not associated with the susceptibility to CP in the studied population.
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Influencia de fatores ambientais e geneticos relacionados com a agenesia dental e microdontia / Influence of genetic and environmental factors related dental agenesis and microdontiaBianchi, Fabio Jose 13 December 2007 (has links)
Orientador: Sergio Roberto Peres Line / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-09T21:08:29Z (GMT). No. of bitstreams: 1
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Previous issue date: 2007 / Resumo: O termo hipodontia pode ser definido como ausência congênita de um ou mais dentes e microdontia como dente com alterações dimensionais. Os dentes mais afetados são os terceiros molares, segundos pré-molares e incisivos laterais. A odontogênese pode ser afetada diretamente por fatores genéticos e ambienatis podendo ser destacado os genes PAX9 e MSX1, e a desnutrição e álcool. O objetivo deste estudo foi avaliar a influência de regiões dos genes supracitados e da ingestão crônica de álcool durante a gravidez na odontogênese, através de análises de polimorfismos genéticos e morfologia de molares de ratos. No primeiro estudo foi analisado o DNA genômico de 130 indivíduos afetados com agenesia e 110 indivíduos controles. Após a obtenção e extração do DNA, a região G/C-915 do gene PAX9 (NCBI ref SNP ID: rs 2073247) foi amplificadas por reação em cadeia da polimerase (PCR), os polimorfismos foram analisados com duas seqüências diferentes de primers. Os géis foram corados pelo nitrato de prata. Os dados foram analisados através das Simulações de Monte Carlos (programa Clump) e teste Qui-quadrado ao nível de significância de 5%. As análises mostraram que o polimorfismo da região promotora do PAX9 G/C-915 teve alta freqüência em indíviduos com hipodontia de terceiros molares. No segundo estudo foram estudadas região dos genes PAX9 e MSX1, embora, não houve relação da região estudada dos introns do MSX1 com agenesia de terceiros molares, na região do gene C-160T do gene PAX9 (www.ncbi.nlm.nih.gov/SNP ref 2073247) houve relação entre polimorfismo e agenesia de terceiros molares. Com relação a fatores ambientais, o objetivo deste trabalho foi avaliar os efeitos do álcool administrado durante a gravidez e na lactação em molares inferiores de ratos. Observou-se uma redução nas dimensões e microdureza Knoop desses elementos dentais / Abstract: The term hypodontia can be defined as a congenital absence of one or more teeth and microdontia teeth with alterations dimensional. The most affected teeth are the third molars, seconds premolars and lateral incisors. Genetic and environmental factors such as PAX9 and MSX1 genes malnutrition and alcohol can directly affect the odontogenesis. The objective of this study was to analyze the influence of gene regions and chronic alcohol intake during pregnancy in odontogenesis, through analysis of genetic polymorphism and morphology of rats molars. In the first study was analyzed the genomic DNA of 130 affected individuals with agenesis and 110 controls. After obtaining and extraction of DNA, the region. After DNA extraction, the region G/C-915 PAX9 gene (NCBI ref SNP ID: rs 2073247) was amplyfied by polymerase chain reaction (PCR). The polymorphic sites were analyzed by two different primers sequences. The gel bands were stained by silver nitrate. Data were analyzed by Monte Carlo simulations (Clump software) and Chi-squared test (x2)with the significance level 5%. The analysis showed that the PAX9 promoter region polymorphism of the G/C-915 had high frequency in individuals with third molars hypodontia. In the second study were studied region of genes PAX9 and, though, there was no relationship in the region of MSX1 introns with third molars agenesis, in the region of C-160T the gene PAX9 (www.ncbi.nlm.nih.gov / SNP ref 2073247) was relationship between polymorphism and third molars agenesis. About to environmental factors, the objective of this thesis was assessing the alcohol effects administered during pregnancy and lactation in lowers molars rats. There was a reduction in size and Knoop microhardness in these dental elements / Doutorado / Histologia e Embriologia / Doutor em Biologia Buco-Dental
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Estudo do polimorfismo C2029T no gene do receptor toll-like tipo 2 e da resposta imune humoral em pacientes com hansenÃase / Study of C2029T polymorphism in gene receptor toll-like type 2 and humoral immune response in patients with leprosyAracÃlia Gurgel Rodrigues 17 December 2008 (has links)
FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / Apesar do empenho do MinistÃrio da SaÃde para a eliminaÃÃo da hansenÃase, o Brasil à o segundo paÃs em nÃmero de casos no mundo, precedido pela Ãndia, e responsÃvel por 80% dos casos no continente americano, sendo o Nordeste do paÃs e, em especial, o Estado do Cearà considerado uma regiÃo de alta endemicidade. De acordo com a classificaÃÃo de Ridley e Jopling, as formas clÃnicas dividem-se em virchowiana, dimorfa-virchowiana, dimorfa-dimorfa, dimorfa-tuberculÃide e tuberculÃide. O trabalho foi realizado com 87 pacientes com hansenÃase, sendo 51,72% do sexo feminino e 48,3% do sexo masculino; destes 87 pacientes, 77,01% vacinados em algum perÃodo da vida entre a infÃncia a adolescÃncia. Os pacientes incluÃdos no estudo encontravam-se nÃo tratados (n=23) ou em tratamento (n=64), apresentando a maioria dos pacientes a hansenÃase pela primeira vez e alguns apresentavam recidiva (n=11). A sorologia de IgG sÃrica anti-PGL1 foi realizada em 83 pacientes, tendo sido as concentraÃÃes de maiores diferenÃas ocorridas entre os grupos com a forma tuberculÃide e dimorfa-tuberculÃide e o grupo com a forma dimorfa-virchowiana. As 87 amostras analisadas foram amplificadas quanto à seqÃÃncia de 171 pb de uma regiÃo altamente conservada dos aminoÃcidos 671-692 do C-terminal no domÃnio intracelular do receptor Toll-like 2 e foi aplicada a tÃcnica de AnÃlise do Polimorfismo Conformacional de Fita Ãnica (SSCP). O perfil eletroforÃtico das amostras testadas encontradas foram de duas e trÃs bandas, mostrando-se necessÃrio o sequenciamento,este apresentou heterozigose marcado pela presenÃa das bases C e T na posiÃÃo C2029T, e alÃm de dois outros perfis de heterozigose nas posiÃÃes C2006T (encontrado em todas as amostras sequenciadas) e T2008G (amostra 82). O trabalho sugere que houve heterozigose na regiÃo do Ãxon 3 do gene do receptor toll-like tipo 2, diferentemente do encontrado por Kang e Chae (2001) o que pode significar que o perfil de suscetibilidade em nossa populaÃÃo à distinta daqueles encontrados na Ãndia e na CorÃia. / Although several efforts from Ministry of Health have been made in order to eliminate leprosy, Brazil is still the second country with the highest number of cases in world after India and is responsible for 80% of the cases in the American continent, the Ceara state situated in the Norheastern region is considered to have high incidence rates of leprosy cases. According to Ridley and Jopling classification, the clinical forms of leprosy can be divided in lepromatous leprosy, borderline lepromatous leprosy, borderline borderline leprosy, borderline tuberculoid leprosy, and tuberculoid leprosy. This work was done with 87 patients with leprosy, being 51.72 % of the female gender and 48.3% of the male gender; from the total of patients, 77.0% had been vaccinated with BCG once in life. All the patients enrolled in the study were not treated (n=23) or in treatment (n=64). Most of the patients had suffered from leprosy for the first time and some (n=11) had suffered from leprosy recidive. The anti-PGL1 serum IgG serology has been performed in 83 patients, and the most significant differences were found comparing the tuberculoid leprosy and borderline tuberculoid leprosy groups with the borderline lepromatous leprosy group. All DNA samples (n=87) were amplified in respect to the 171 bp highly conserved sequence of the aminoacids 671-692 from the C-terminal intra-cellular domain of Toll-like 2 receptor, and they were submitted to a Single Strain Conformation Polymorphism Technique (SSCP). The eletrophoretic profile found of the samples showed two and three bands, it is essential to the sequencing, this showed heterozygosis at position C2029T, and in addition two other sections of heterozygosity at positions C2006T (found in all four sequenced samples) and 2008 (sample 82). The work showed that the heterozygosity found in the gene exon 3 of the tool-like receptor type 2, unlike the one found by Kang and Chae (2001) which may mean that the susceptibility profile from our population is distinct from those found in India and Korea.
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Estudo genÃtico de caracterÃsticas de importÃncia econÃmica em uma populaÃÃo multirracial de ovinos de corte: uma abordagem quantitativa e molecular / Genetic study for economic traits in a multiracial population of meat sheep: a quantitative and molecular approachAna Maria Bezerra Oliveira LÃbo 15 February 2008 (has links)
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / Atualmente, existe uma grande possibilidade de associaÃÃo entre as Ãreas de genÃtica quantitativa e de genÃtica molecular. Isto pode causar importante impacto na seleÃÃo
de ovinos, com o estabelecimento de eficientes critÃrios de seleÃÃo para produÃÃo de carne. Com isso, os objetivos deste trabalho foram: verificar polimorfismos nos genes GDF9,
Calpastatina e Aromatase (CYP19); verificar a freqÃÃncia de variantes alÃlicas do tipo SNP nestes genes; verificar os efeitos destas variantes sobre caracterÃsticas produtivas e
reprodutivas de ovinos de uma populaÃÃo multirracial; estimar os parÃmetros genÃticos e os valores genÃticos destas caracterÃsticas, nesta populaÃÃo; verificar o efeito da inclusÃo do genÃtipo para estes genes nos modelos para estimativas de parÃmetros genÃticos e verificar o efeito do genÃtipo para estes genes sobre os valores genÃticos estimados. O gene GDF9 à um gene candidato relacionado com o fenÃtipo de alta prolificidade. O gene da Calpastatina possui importÃncia na produÃÃo de animais de corte, por està relacionado ao crescimento e a qualidade da carne. O gene da aromatase à um candidato afetando o desempenho produtivo e reprodutivo, pelo seu importante papel no metabolismo dos hormÃnios esterÃides. O polimorfismo do tipo (SNP) do gene CYP19 foi investigado pela tÃcnica PCR-RFLP em uma amostra de 133 animais de diversos grupos genÃticos de ovinos de corte. Foram estimadas as freqÃÃncias alÃlicas e genotÃpicas de polimorfismos deste gene e investigado o efeito destas variantes sobre caracterÃsticas de crescimento, reprodutivas e de habilidade materna, utilizando o procedimento GLM do software SAS. As caracterÃsticas estudadas foram peso ao nascer (PN), peso ao desmame (PD), peso ao abate (PA), peso a um ano de idade (P1), ganho de peso mÃdio diÃrio do nascimento ao desmame (Gn_d), ganho de peso mÃdio diÃrio do desmame ao abate (Gdes_abat), ganho de peso mÃdio diÃrio do desmame a um ano de idade (Gdes_ano), idade ao primeiro parto (IPP), intervalo de partos (IP), perÃodo de gestaÃÃo (PG), dias para o parto (DP), peso total de crias nascidas por matriz por parto (PTCN) e peso total de crias desmamadas por matriz por parto (PTCD). ParÃmetros genÃticos e valores genÃticos foram estimados utilizando o mÃtodo da MÃxima VerossimilhanÃa Restrita Livre de Derivadas (DFREML). Foi avaliado o efeito da inclusÃo do genÃtipo para o gene da aromatase nos modelos para estimativas de parÃmetros genÃticos. Foi verificado o efeito do genÃtipo sobre os valores genÃticos estimados. NÃo foi possÃvel genotipar os animais para os genes GDF9 e Calpastatina, devido a dificuldades de padronizar as reaÃÃes. Assim, os animais foram genotipados apenas para o gene da aromatase. Na amostra estudada para o gene da aromatase, nÃo foram observados indivÃduos com genÃtipo AA. As freqÃÃncias para os genÃtipos AB e BB foram 0,65 e 0,35, respectivamente. A freqÃÃncia alÃlica diferiu entre os grupos genÃticos estudados. O gene da aromatase apresentou influÃncia sobre a maioria das caracterÃsticas estudadas, havendo diferenÃas no padrÃo desta influÃncia, de acordo com o grupo genÃtico considerado. As herdabilidades diretas estimadas foram 0,21, 0,25, 0,52, 0,39, 0,24, 0,20, 0,21, respectivamente, para PN, PD, PA, P1, Gn_d, Gdes_abat e Gdes_ano, e 0,01, 0,06, 0,14, 0,06, 0,20 e 0,11, respectivamente, para IPP, IP, PG, DP, PTCN e PTCD. CorrelaÃÃes genÃticas positivas foram estimadas entre os pesos corporais. A correlaÃÃo genÃtica entre Gn_d e Gdes_abat foi de 0,37 e entre Gn_d e Gdes_ano foi de 0,55. CorrelaÃÃes genÃticas negativas foram estimadas entre IPP com IP e PG. PTCN apresentou correlaÃÃo genÃtica de 0,52 com PTCD. O uso da informaÃÃo do genÃtipo dos animais para o gene da aromatase melhorou o ajuste dos modelos de anÃlises genÃtica sob metodologia BLUP. Os indivÃduos com genÃtipo AB apresentaram superioridade genÃtica em relaÃÃo Ãqueles de genÃtipo BB para a maioria das caracterÃsticas estudadas. Pode se concluir que o uso da seleÃÃo assistida por marcadores permitirà o aumento da eficiÃncia da seleÃÃo atualmente em prÃtica com o uso das metodologias tradicionais de genÃtica quantitativa / Nowadays, there is great possibility of association between quantitative and molecular genetics. An important impact would be expected in the sheep selection, with the establishment of efficient criteria for meat production selection. The aims of this work were to verify polymorphisms in GDF9, Calpastatine and Aromatase (CYP19) genes; to verify the frequencies of SNP allelic variants in these genes; to verify the effects of these variants on
productive and reproductive traits in a multiracial sheep population; to estimate genetic parameters and breeding values of these traits in this population; to verify the effect of genotype of these genes on models to estimate the genetic parameters and to verify the effect of genotype for these genes on estimated breeding values. GDF9 gene is a candidate related to phenotype of high prolificacy. The calpastatine gene has importance on production of meat animals, as it is related to growth and meat quality. Aromatase gene is a candidate affecting the productive and reproductive performance, by its important role in the steroid hormone metabolism. SNP polymorphism of CYP19 gene was investigated by PCR-RFLP technique in a sample of 133 animals from several breed groups of meat sheep. Allelic and genotypic frequencies were estimated for this polymorphism and the effect of these variants on growth,reproductive and maternal traits were investigated, using GLM procedure of SAS software. The studied traits were birth weight (PN), weaning weight (PD), slaughter weight (PA), yearling weight (P1), weight gain from birth to weaning (Gn_d), weight gain from weaning to slaughter (Gdes_abat), weight gain from weaning to yearling (Gdes_ano), age at first lambing (IPP), lambing interval (IP), gestation length (PG), lambing date (DP), total weight of lambs born for female for lambing (PTCN) and total weight of weaned lambs for female for lambing (PTCD). Genetic parameters and breeding values were estimated by Derivative Free Restricted Maximum Likelihood (DFREML) method. The effect of genotype inclusion in analysis models for estimation of genetic parameters was evaluated. The effect of genotype on estimated breeding value was verified. It was not possible to verify the genotype of the animals for GDF9 and Calpastatine genes due the difficulties on the reactions standardizations. So the animals were genotyped only for aromatase gene. In studied sample, it is not observed animals with AA genotype. The frequencies for AB and BB were 0.65 and 0.35,respectively. The allelic frequency did differ among studied breed groups. The aromatase gene presented influence on most studied traits, with difference in this influence according to breed group. The direct heritabilities were 0.21, 0.25, 0.52, 0.39, 0.24, 0.20, 0.21, respectively, for PN, PD, PA, P1, Gn_d, Gdes_abat and Gdes_ano, and 0.01, 0.06, 0.14, 0.06, 0.20 and 0.11, respectively, for IPP, IP, PG, DP, PTCN and PTCD. Positive genetic correlations were estimated among corporal weights. Genetic correlation between Gn_d and Gdes_abat was 0.37 and between Gn_d and Gdes_ano was 0.55. Negative genetic correlations were estimated between IPP with IP and PG. PTCN presented genetic correlation of 0.52 with PTCD. The use of information of genotype of aromatase gene increased the efficiency of models for genetic analyses by BLUP methodology. The animals with AB genotype presented
genetic superiority for most studied traits in relation to those with BB genotype. It is possible conclude that the use of marked assisted selection will permit increase the efficiency of selection today in practice with the use of traditional quantitative genetic methodologies
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Application of process analytical technology (PAT) tools for the better understanding and control of the crystallization of polymorphic and impure systemsSimone, Elena January 2015 (has links)
This work presents a comprehensive study on the application of PAT tools to study, monitor and control polymorphism during batch cooling crystallization processes. For the first time, the same techniques were used to control and adjust polymorphic purity of the solid phase but also to investigate the relation between chemical equilibrium in solution and polymorphic outcome of cooling crystallization. Crystallization is an important unit operation used as separation and purification technique. It is widely employed in the pharmaceutical, chemical, agrochemical, food and cosmetics industries but also in the electronic, metallurgic and material industries. More than 90% of the APIs on the market are produced by crystallization, therefore, monitoring and control this process is fundamental to ensure the quality of the final product. The implementation of process analytical technology (PAT) tools during the development stage of APIs has largely helped in better understanding and optimizing both batch and, more recently, continuous crystallization. Polymorphism is the capacity of a compound to crystallize in more than one different crystalline structure, which can have different properties such as density, melting point, bioavailability and solubility. The choice of solvent, pH, kinetic conditions and presence of impurities has very strong effect on the polymorphic outcome of a cooling crystallization in solution. Understanding this phenomenon as well as being able to monitor and control it during industrial crystallization is one the biggest challenges for pharmaceutical industries.
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A supramolecular derivatised study of BIS(Adamantan-1- Aminium) carbonateNgilirabanga, Jean Baptiste January 2014 (has links)
Magister Pharmaceuticae - MPharm / In this study, new solid supramolecular derivatised forms of bis(adamantine-1-aminium) carbonate (ADTCO3) were prepared. ADTCO3 is a derivative of amantadine used for Parkinson’s disease and has antiviral properties against influenza-A, dengue fever and pharmacological activity towards Parkinson’s disease. The new forms prepared were polymorphic and co-crystal forms of ADTCO3. Polymorphism is a phenomenon where the ability of a substance to exist in two or more crystalline forms occurs when crystallised under different conditions and co-crystallization is the process of formation of multicomponent crystals of a drug substance. New solid forms often display different mechanical, physicochemical and thermal properties that can remarkably influence the bioavailability, hygroscopicity and stability of active pharmaceutical ingredients (APIs). For the formation of polymorphs of ADTCO3, techniques such as dry grinding, solvent-drop grinding, co-precipitation, sublimation and vapour diffusion were applied. For the development of co-crystals and/or complex formation, ADTCO3 was treated in combination with ten selected co-formers viz; benzoic acid, 4-hydroxybenzoic acid, cinnamic acid, 4-hydroxycinnamic acid, succinic acid, tartaric acid, salicylic acid, L-glutamic acid, citric acid monohydrate and L-glutaric acid using similar techniques as applied in the polymorphism study. The first four co-formers were selected for their potential biological activity and the latter six were selected for their generally regarded as safe (GRAS) status. All products were isolated and characterized using different analytical techniques to assess the thermal behaviour of the products by hot stage microscopy (HSM), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). FTIR spectroscopy and proton-nuclear magnetic resonance (1HNMR) were used to identify and determine the purity of the parent compounds and the modified forms. X-ray powder diffraction was used to determine the formation of a new phase and single crystal X-ray diffraction was applied at the initial stages to identify ADTCO3 by its unit cell parameters. Furthermore, the Cambridge Structural Database (CSD) and other resources were used to generate information on the molecular structures of all elucidated parent compounds, their polymorphs and reported co-crystals. Four different polymorphic forms of ADTCO3 were identified (viz. ADTCO3 Forms I to IV) and sixteen co-crystals (viz. ADTCO3BA1 to ADTCO3BA5, ADTCO3HBA, ADTCO3CIN, ADTCO3HCIN, ADTCO3SUC, ADTCO3LTTA, ADTCO3SA, ADTCO3CA, ADTCO3GLA, ADTCO3GA) were synthesised. Of the sixteen co-crystals 5 were identified as ADTCO3BA “salt” co-crystal polymorphic forms and 2 as ADTCO3SUC co-crystal polymorphic forms. Two solvated “salt” co-crystal forms were also identified, namely; ADTCO3GLA and ADTCO3LTTA. ADTCO3GLA had a mass loss of 10.3% (n = 2.4) and ADTCO3LTTA had a mass loss of 5.25% (n = 0.86). Finally, the rest of the co-crystals ADTCO3HBA, ADTCO3CIN, ADTCO3HCIN, ADTCO3SA, ADTCO3CA and ADTCO3GA all crystallised as “salt” co-crystals.
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Linear clustering with application to single nucleotide polymorphism genotypingYan, Guohua 11 1900 (has links)
Single nucleotide polymorphisms (SNPs) have been increasingly popular for
a wide range of genetic studies. A high-throughput genotyping technologies
usually involves a statistical genotype calling algorithm. Most calling
algorithms in the literature, using methods such as k-means and mixturemodels,
rely on elliptical structures of the genotyping data; they may fail
when the minor allele homozygous cluster is small or absent, or when the
data have extreme tails or linear patterns.
We propose an automatic genotype calling algorithm by further developing
a linear grouping algorithm (Van Aelst et al., 2006). The proposed
algorithm clusters unnormalized data points around lines as against around
centroids. In addition, we associate a quality value, silhouette width, with
each DNA sample and a whole plate as well. This algorithm shows promise
for genotyping data generated from TaqMan technology (Applied Biosystems).
A key feature of the proposed algorithm is that it applies to unnormalized
fluorescent signals when the TaqMan SNP assay is used. The
algorithm could also be potentially adapted to other fluorescence-based SNP
genotyping technologies such as Invader Assay.
Motivated by the SNP genotyping problem, we propose a partial likelihood
approach to linear clustering which explores potential linear clusters
in a data set. Instead of fully modelling the data, we assume only the signed
orthogonal distance from each data point to a hyperplane is normally distributed.
Its relationships with several existing clustering methods are discussed.
Some existing methods to determine the number of components in a
data set are adapted to this linear clustering setting. Several simulated and
real data sets are analyzed for comparison and illustration purpose. We also
investigate some asymptotic properties of the partial likelihood approach.
A Bayesian version of this methodology is helpful if some clusters are
sparse but there is strong prior information about their approximate locations
or properties. We propose a Bayesian hierarchical approach which is
particularly appropriate for identifying sparse linear clusters. We show that
the sparse cluster in SNP genotyping datasets can be successfully identified
after a careful specification of the prior distributions. / Science, Faculty of / Statistics, Department of / Graduate
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Epr of substitutional fe3 in a natural crystal of brookite (tio2)Rostworowski, Juan Adalberto January 1972 (has links)
EPR spectra of Fe³⁺ in a natural crystal of brookite have been investigated at X- and Q-band frequencies at room temperature and 573°K. Part of the paramagnetic resonance spectrum observed has been interpreted on the assumption that Fe³⁺occupies eight equivalent Ti⁴⁺ sites in brookite, with four inequivalent orientations..
The spectra show an "intermediate" zero-field splitting at X-band and a "normal" zero field splitting at Q-band frequencies.
The spin Hamiltonian parameters which fit the spectra are the following:
g = 2.002 ± 0.005 .
D = (1170 ± 30) x 10⁻⁴cm⁻¹
E = (330 ± 20) x 10⁻⁴cm⁻¹
[pa + (l/l2)qF]₀₁₀ = (13±10) x 10⁻⁴cm⁻¹
[pa + (l/l2)qF]₁₀₀ = (-13±15) x l0⁻⁴cm⁻¹
[pa + (l/l2)qF]₀₀₁ = (-66±4) x l0⁻⁴cm⁻¹ / Science, Faculty of / Physics and Astronomy, Department of / Graduate
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Polymorphism in long-chain n-alkylammonium halides.Rademeyer, Melanie 16 May 2008 (has links)
Long-chain molecules are widely used in many commercial products, including waxes, oils, fats and soaps. This study focuses on the primary n-alkylammonium chlorides that have applications as surfactants, detergents and as models for bio-membranes. The specific topic of this investigation is the polymorphism of three series of n-alkylammonium halides. Polymorphism is the ability of a substance to exist in more than one crystal form. Due to the conformational flexibility of the long alkyl chain and the forces (hydrogen bonding and van der Waals interactions) dictating the packing in these compounds, more than one type of molecular packing is possible, resulting in the crystallization of various polymorphs for each compound. Various investigations of the polymorphism of n-alkylammonium halides have been published in the scientific literature. This includes mainly studies on the polymorphism and structures of n-alkylammonium chlorides. Only a few reports on investigations of the polymorphism of n-alkylammonium bromides were found in the literature, but no investigation of the polymorphism of n-alkylammonium iodides could be located. This study is limited to the medium chain length primary n-alkylammonium halides, CnH2n+1N+H3X- where n = 11 to 18 (except 17) and X = Cl, Br and I. It is expected that in this chain length range, both packing forces (hydrogen bonding and van der Waals interactions) will play a role in dictating the molecular packing. It was attempted to crystallize the maximum number of polymorphs of each compound by extensive variation of the crystallization conditions. The parameters varied include crystallization temperature, solvent and crystallization method. Information regarding the polymorphism of a compound crystallized under specific conditions were collected by the complementary techniques of X-ray diffraction and thermal analysis. X-ray diffraction is the ideal technique to study polymorphism because the result of such an investigation is the three-dimensional packing in the crystal structure. Due to the wide scope of the investigation, only the polymorphic forms stable at room temperature were investigated. The single crystal X-ray technique allows the determination of the crystal structure of a polymorph, but due to the tendency of the compounds to crystallize in thin plates, very few single crystals of good diffraction quality were obtained. Nine crystal structures were, however, determined. Most polymorphic forms were available as polycrystalline powders. The new techniques for crystal structure determination from powder data were employed to determine two crystal structures from powder diffraction data, although at lower precision, and further refined them by the Rietveld technique. Conventional X-ray powder diffraction is well suited to the identification of polycrystalline materials. The technique does not give direct information regarding the structural nature of the polymorph, but gives a unique fingerprint for each polymorphic form. All polymorphs that were obtained by the various crystallization techniques were characterised by X-ray powder diffraction, and the unique long Summary iispacing of each polymorphic form was determined from the position of the low angle diffraction peaks in the diffraction pattern. Linear correlations between the chain lengths and long spacings were used to search for the presence of isostructural series amongst the phases. More than one isostructural series could be identified for each homologous series of compounds. Thermal analysis techniques were employed to determine the phase transition temperatures and enthalpies of phase transitions occurring at temperatures above room temperature. In this investigation the thermal behaviour of polymorphs were investigated by differential scanning calorimetry (DSC), thermo-gravimetric analysis (TGA) and hot stage microscopy (HSM). A stepwise melting behaviour that includes various solid-solid phase transitions was observed for all compounds studied. The sequence of phase transitions that occur with an increase in temperature were found to be unique to a specific polymorphic form. Thermogravimetric analysis provided information regarding the incorporation of solvent in the crystal lattice by monitoring the change of sample weight with increase in temperature. Hot stage microscopy allowed the visual observation of changes occurring in the morphology and texture of the sample with temperature. This investigation contributed a large amount of information to the pool of knowledge on the crystalline phases of the n-alkylammonium halides. Up to now, not much structural data on the crystal forms of these compounds were available in the literature. In this study, complex patterns of crystal packing and phase transitions were revealed. Six isostructural series of n-alkylammonium chlorides were identified, three of which have not been reported previously, and the crystal structure of one of the novel forms was determined. Four isostructural polymorphic forms of n-alkylammonium bromides were identified. Only two forms have been reported previously in the literature. Six crystal structures of compounds with a novel crystal form were determined. For the homologous series of n-alkylammonium iodides, four novel isostructural series were identified, and one structure was determined. Relationships between chain lengths and structural parameters like long spacings, unit cell parameters and phase transition temperatures were determined and expressed as mathematical functions. An analysis of all the known structures (structures reported in the literature and structures determined in this investigation) indicated that different molecular conformations and hydrogen bonds are responsible for differences in the packing, as expressed in the formation of polymorphs. A choice of anion for a specific compound (chloride, bromide or iodide) influenced not only the cell volume, as would be expected, but also dictated the preferential formation of pseudo-polymorphs and complex hydrogen bonding networks in the crystals themselves. Phase transition temperatures were found to be not simply a function of chain length, but to be significantly influenced by the anion and polymorphic form present. / Prof. G.J. Kruger
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