• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1748
  • 1264
  • 459
  • 395
  • 185
  • 124
  • 61
  • 61
  • 49
  • 44
  • 36
  • 32
  • 27
  • 27
  • 27
  • Tagged with
  • 5472
  • 1170
  • 799
  • 683
  • 672
  • 443
  • 440
  • 440
  • 394
  • 365
  • 355
  • 317
  • 311
  • 290
  • 272
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
301

Algodão modificado com complexantes como pre-concentrador de ions metalicos em amostras ambientais, para analise por fluorescencia de raio X

Jesus Filho, Antenor Lopes de 03 August 2018 (has links)
Orientador: Maria Izabel Maretti Silveira Bueno / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-03T21:54:23Z (GMT). No. of bitstreams: 1 JesusFilho_AntenorLopesde_D.pdf: 11942561 bytes, checksum: 00d8d4ec9cb462cfc21d900ad190ccbf (MD5) Previous issue date: 2003 / Doutorado
302

Faca sem ponta, galinha sem pé, homem com homem, mulher com mulher : relações de genero nas brincadeiras de meninos e meninas na pre-escola

Finco, Daniela 03 August 2018 (has links)
Orientador: Ana Lucia Goulart de Faria / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Educação / Made available in DSpace on 2018-08-03T23:20:27Z (GMT). No. of bitstreams: 1 Finco_Daniela_M.pdf: 22576541 bytes, checksum: 7dedbf3fd8554fc6a6fa7b1c92f897ef (MD5) Previous issue date: 2004 / Resumo: Relações de gênero nas brincadeiras entre meninos e meninas de 4 a 6 anos, de uma Escola Municipal de Educação Infantil de Campinas, SP - este é o foco desta pesquisa, que compreende as crianças como atores e atrizes dos processos sociais, como portadores e portadoras de história, reproduzindo e produzindo cultura. O estudo discute as formas de brincadeiras de meninos e meninas, buscando questionar o fato "natural' de que meninos e meninas possuem papéis e comportamentos pré-determinados. Apresenta uma reflexão sobre a troca de papéis nas brincadeiras, fazendo uma discussão sobre os brinquedos considerados "certos" e "errados" para cada sexo. A análise discute os resultados de outras pesquisas e questiona quando afirmam que meninos e meninas demonstram comportamentos, preferências, competências, atributos de personalidade mais apropriados para o seu sexo, seguindo, desde bem pequenos, as normas e padrões estabelecidos. Desse modo, o estudo propõe-se a tratar o tema das relações de gênero de uma perspectiva diferenciada, na tentativa de um olhar não "aduItocêntrico", observando atentamente as transgressões dos papéis sexuais nos momentos de brincadeira, possibilitando enxergar novas formas de ser menino e de ser menina. Ao buscar contextualizar as condições em que ocorrem essas relações, a pesquisa aponta para as formas de construção cultural da corporalidade feminina e masculina e sua relação com as brincadeiras e os brinquedos. Desse modo, o brinquedo, é analisado como um artefato cultural, compreendido como um dispositivo que está relacionado aos processos de construção de idéias, valores, comportamentos, saberes e com um enredo social carregado de significados e intencionalidades. A pesquisa também registra as angústias e dúvidas das professoras da pré-escola frente a questões de gênero na infância, apontando para a dificuldade da diferenciação entre a identidade de gênero e a identidade sexual e discutindo a ausência do tema em cursos de formação. A bibliografia italiana traduzida para o português destacou-se como referência para a concepção de educação infantil. A leitura sobre gênero ajudou a treinar meu olhar para duvidar e estranhar as naturalidades das pistas: Revista dos Estudos Feministas (UFSC), Cadernos Pagu (Núcleo de gênero da UNICAMP), Cadernos de Pesquisa (FCC), as pesquisas do GEERGE (Grupo de Estudos de Educação e Relações de Gênero da UFRS e do NEMGE (Núcleo de Estudos da Mulher e das relações sociais de gênero) da USP). Outras fontes não convencionais, como a literatura infantil e a produção cinematográfica, serviram para a compreensão da temática, permitindo percepções diferenciadas. O estudo conclui que ê necessário questionar o papel social das Instituições de Educação Infantil - creches e pré-escolas -, considerando a sua potencialidade em relação a diversidade e à capacidade de criação e recriação apresentadas pelos meninos e meninas, repensando seu papel frente à diferença existente entre eles. A análise traz questões para repensar a maneira como as (os) diferentes profissionais da pré-escola trabalham as relações de gênero na pequena infância. Uma temática que, sem dúvida, necessita ser mais discutida e aprofundada / Abstract: Gender relationships in the plays between boys and girls (4 and 6 years oId) at Campinas (SP) pubIic pre-school (EMEI). This is the focus of this research, that understands the children as actors and actresses of social processes, who carry history, reproducing and producing culture. This work analyses the way of to pIay of boys and girls, discussing the "natural" fact of boys and girls to have predetermined roles and behaviors. It presents a reflection on the exchange of sex-roles in pIay, discussing the toys considered "right" and "wrong" for each sex. The analysis opposes researches that consider that boys and girIs demonstrate behaviors, preferences, abilities and personality's attributes appropriated for their sex, following since very young, the established norms and standards. Thereby, intently observing the transgressions of the sex-role during play, this study proposes to deal with the subject of gender relationships from a differentiated perspective, where the "adult is not the center", making possible to realize new forms of being boy and being girl. During the creation of the context of these relations, this study indicates forms of feminine and masculine cultural construction and its relation with children's play and toys. In this way, the toy is analyzed as a cultural device, understood as a device related to the construction of ideas, values, behaviors, knowledge and full of meanings and intentionalities. The research also registers afflictions and doubts of pre-school teachers in face of questions about gender in early childhood, indicating difficulties of the differentiation of gender identity of the sexual identity, analyzing the absence of this subject in the formation of the teachers. The Italian bibliography, translated into the Portuguese, was distinguished as reference for the conception of early childhood. The readings about gender helped to train my eyes to doubt and to find queer of the naturalness of the tracks: Revista de estudos femininos from UFSC (Universidade Federal de Santa Catarina), Cadernos Pagu (Center of gender studies) from UNICAMP (Universidade Estadual de Campinas), Cadernos de Pesquisa from FCC (Fundação Carlos Chagas), the research of GEERGE (Grupo de Estudos de Educação e Relações de Gênero) from UFRGS (Universidade Federal do Rio Grande do Sul) and of NEMGE (Núcleo de Estudos da Mulher e das relações sociais de gênero) from USP (Universidade de São Paulo). Other non conventional sources, as childhood literature and the cinematography production, had served for the thematic understanding, allowing differentiated perceptions. The study concludes that it is necessary to question the social role of the day-care Centers and pre-schools considering its potential in relation the diversity and the capacity of creation and re-creation of boys and girls, rethinking the roles in face of the differences. This study presents questions to rethink the manner as the pre-school with various professionals handle the gender's relations in the early childhood. This thematic, of course, needs to be deeply argued. / Mestrado / Mestre em Educação
303

Interrupção de gestação por anomalia fetal incompativel com a vida apos o nascimento : as vivencias das mulheres

Costa, Lucia de Lourdes Ferreira da 09 August 2004 (has links)
Orientador : Ellen E. Hardy / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-03T23:36:40Z (GMT). No. of bitstreams: 1 Costa_LuciadeLourdesFerreirada_M.pdf: 3849823 bytes, checksum: 8222fc50684ed10bcb9fdd6124865c1e (MD5) Previous issue date: 2004 / Resumo: O desenvolvimento de novas tecnologias médicas para o diagnóstico pré-natal possibilita a descoberta precoce e muito precisa de anomalias fetais incompatíveis com a vida após o nascimento. Isto tem levado casais a solicitarem autorização judicial para interromper a gravidez, o que não está previsto pela lei brasileira. Para isto é necessária a apresentação de laudo médico em que se explica o diagnóstico e prognóstico do feto, segundo a literatura científica. Nesses casos, as autorizações têm-se tomado cada vez mais freqüentes. No Centro de Atenção Integral à Saúde da Mulher da Universidade Estadual de Campinas, para atender as mulheres que desejam interromper a gestação porque o feto não sobreviverá após o nascimento, tem sido adotado um conjunto de procedimentos embasados na experiência dos profissionais envolvidos e nos achados da literatura. Entretanto, a vivência das mulheres com a interrupção da gravidez não tinha sido avaliada. Objetivo: Conhecer as vivências das mulheres que decidiram interromper uma gravidez, com autorização judicial, quando o feto foi diagnosticado com malformação incompatível com a vida após o nascimento. Sujeitos e Métodos: Foi desenvolvido um estudo qualitativo,para o qual foram entrevistadas 10 mulheres que interromperam a gravidez no CAISMlUnicamp, utilizando um roteiro temático como parte de uma técnica de relato de vida - depoimentos pessoais. As entrevistas foram gravadas e transcritas e realizou-se a análise temática de seu conteúdo com a ajuda do programa computacional Ethnograph v. 5.0. Resultados: As mulheres entrevistadas não haviam planejado a gestação que acabou sendo interrompida, mas, com exceção de uma, todas declararam que a haviam desejado. O diagnóstico de malformação fetal nem sempre foi comunicado de maneira adequada pelo ecografista. Diante do diagnóstico as mulheres referiram choque, medo, desespero, angústia, sensação de inutilidade e inconformismo. A decisão de interromper a gestação esteve baseada no entendimento de que seria a melhor altemativa para aliviar o padecimento do feto e o sofrimento emocional delas próprias. As entrevistadas vivenciaram essa decisão com tristeza, desespero e culpa, sentindo-se cruéis, o que Ihes trouxe ainda maior sofrimento. A vivência do feticídio, desde o momento em que foram informadas sobre o procedimento e, especialmente, durante a sua realização, foi considerada pelas mulheres a parte mais difícil no processo de interrupção. Durante a indução do parto e no parto as mulheres experimentaram sentimentos de choque, tristeza, pânico, agonia, inconformismo, mágoa, solidão, medo e arrependimento. Quarenta dias depois da interrupção, as mulheres referiram estar mais conformadas, porém ainda choravam muito, sentiam-se tristes, sensíveis e perplexas. Entretanto, estavam satisfeitas com a decisão tomada. Essa experiência também teve um impacto positivo na vida delas, já que referiram que contribuiu para seu amadurecimento e para melhorar o seu relacionamento com o companheiro. Conclusão: As mulheres que decidem interromper a gravidez porque o feto apresenta um diagnóstico de malformação incompatível com a vida após o nascimento necessitam do suporte de uma equipe multiprofissional para que recebam apoio e acolhimento, considerando-se que essa experiência é marcada por sofrimento e ambivalência desde o momento em que são informadas do diagnóstico, que não se encerra no pós-parto imediato / Abstract: The development of new medical technologies for pre natal diagnosis allows lhe early and precise identification of fetal abnormalities that are incompatible with life after birth. This has led couples to request legal authorization for pregnancy termination, since it is not allowed by Brazilian law. Presentation of a medical report explaining lhe diagnosis and prognosis of lhe fetus, according to lhe scientific literature, is required. uthorizations, in these cases, have become more frequent. At lhe Centro de Atenção Integral à Saúde da Mulher of lhe Universidade Estadual de Campinas (CAISM/Unicamp) a sei of procedures, based on lhe experience of lhe professionals involved and on scientific literature, hasbeen adopted to care for women who want to terminate a pregnancy when lhe fetus can not survive after birth. However, women's experience with pregnancy termination had not been evaluated. Objective: To leam about lhe life experiences of women who decided to terminate a pregnancy, with legal authorization, when he fetus was diagnosed with a malformation incompatible with life after birth. Subjects and Methods: A qualitative study was carried Qui, with ten women who terminated pregnancy at lhe CAISM/Unicamp, which were interviewed using a thematic guide as part of a life report technique - personal testimonies. The interviews were tape recorded and transcribed, and a thematic analysis was carried out with the aid of the Ethnograph v. 5.0. Results: The women interviewed had not planned the pregnancy that was terminated. However they ali claimed that it was desired. The diagnosis of the fetal abnormality was frequently provided by the doctor responsible for the ultrasonography, not always adequately. After leaming about the diagnosis, women referred shock, crying, tear, despair, anguish, suffering, feeling useless and not accepting the situation. The decision to end pregnancy was based on the understanding that it would be the best altemative to alleviate suffering both, the fetus and themselves. Interviewees referred that, this ecision brought feelings of sadness, despair and guilt, feeling cruel, resulting in even more suffering. The "feticide", since the moment they were informed of the procedure and, specially, during the procedure was considered the most difficult experience of the termination procedure. Through labor induction and delivery women experienced shock, sadness, panic, agony, grief, solitude, tear, regret and did not accepting the fact. Forty days after termination women referred being more comforted, however they still cried a lot, felt sad, sensitive and perplexed. This experience also had a positive impact on women's lives since, as they referred, it contributed towards their maturing and to the enrichment of the relationship with their partner. At the same time they declared that their sexual lives had not changed. Conclusion: Women, who terminate pregnancy, after the fetus was diagnosed with an abnormality incompatible with life after birth, need support from a multi professional team, considering their life marked by suffering and ambiguity, experienced since the moment that they are informed about the abnormality / Mestrado / Ciencias Medicas / Mestre em Tocoginecologia
304

Rastreamento pre-natal para toxoplasmose na rede basica de saude em Campinas : prevalencia dos diferentes perfis sorologicos e comparação da rotina vigente com uma nova proposta

Stella, Juliana Horschutz 14 September 2004 (has links)
Orientador: Eliana Amaral / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-04T00:33:14Z (GMT). No. of bitstreams: 1 Stella_JulianaHorschutz_M.pdf: 709891 bytes, checksum: b26fde7a4ef737b253bc11db4d5992b5 (MD5) Previous issue date: 2004 / Resumo: A toxoplasmose adquirida durante a gestação, de curso benigno em pacientes imunocompetentes e assintomática em 85% dos casos, pode ser transmitida para o feto e resultar em infecção congênita. Embora a grande maioria dos recém-nascidos não apresente sintomas e/ou sinais clínicos, pode evoluir para seqüelas na infância e vida adulta, sendo que a coriorretinite é a lesão mais freqüente. A terapia antenatal reduz a gravidade da doença congênita. Como a primoinfecção materna é predominantemente assintomática, o diagnóstico exige triagem sorológica. As clássicas reações sorológicas foram substituídas por técnicas imunoenzimáticas automatizadas extremamente sensíveis que detectam a IgM residual, tornando a identificação desta imunoglobulina um pobre indicador de infecção recente. Por outro lado, o conhecimento da soroprevalência populacional é essencial para a discussão de programas preventivos da infecção aguda materna e da toxoplasmose congênita. Assim, foram revistos os resultados sorológicos de amostras sangüíneas de rotina pré-natal colhidas nos Centros de Saúde do Município de Campinas entre 01 de março a 31 de maio de 2001. A técnica utilizada pelo Laboratório Municipal para triagem foi a imunoenzimática automatizada MEIA-AxSYM® (Abbott). O tamanho amostral calculado foi de 1.866 amostras, utilizando prevalência de IgM positiva de 1,8%, fixando em 0,6% a diferença em pontos percentuais entre as proporções amostral e populacional e a=0,05. Em 2.199 amostras sangüíneas, o perfil sorológico de imunidade foi observado em 56,1% (IC95% = 54-58,2%), sendo outras 39,2% (IC95%=37,2-41,2) compatíveis com suscetibilidade, 2,5% (IC95% =1,9-3,2) de ¨possível¨ infecção aguda, restando 2,2% (IC95% = 1,3-2,4) de sorologias ¨duvidosas¨. Os diferentes perfis sorológicos foram similarmente distribuídos entre os cinco distritos de saúde de Campinas. Concluiu-se que a alta prevalência de soropositividade para toxoplasmose entre as gestantes em acompanhamento pré-natal na rede municipal de saúde de Campinas sugere um elevado risco de soroconversão (toxoplasmose aguda) na gestação. A comparação de custos diretos estimados mostrou que uma nova proposta de conduta diagnóstica permitiria uma economia de 51% para os gestores municipais de saúde e de 79,5% para o serviço de referência. O acompanhamento sorológico trimestral das gestantes suscetíveis e o emprego do teste de avidez de anticorpos na primeira amostra sangüínea coletada nos Centros de Saúde para as gestantes com ¨possível¨ infecção aguda, melhorariam a performance para detecção dos fetos acometidos congenitamente / Abstract: Toxoplasmosis acquired during pregnancy, a benign and asymptomatic disease in 85% of patients, it can cause congenital infection. If in the majority of these cases there are no signs or symptoms, sequeleae can be appear later durinf infancy and adulthood, having corioretinits as the most frequent finding. The antenatal therapy is able to reduce severity and congenital disease. As acute infection is mainly asymptomatic, the diagnosis is based on serological screening. Recently, classic serological tests were replaced by automated immunoenzime tests which are highly sensitive, detecting residual IgM, now a poor indicator for acute infection. Knowing seroprevalence in pregnant women is essential to discuss prevention programmes on acute and congenital infection. We reviewed serum samples from pregnant women, taking for antenatal routine screening at the Primary Healty Centers in Campinas from March 1st to May 31st. All tests were performed at the Municipla Laboratory, using MEIA-AxSYM® (Abbott). Taking the results found, estimates costs for the routine performed in 2001, with no attempt to date maternal infection and provide follow up to susceptible women, mere compared to a new proposal based on updated literature, including IgG avidity tests. The sample size (N= 1886) was calculated based in 1.8% IgM prevalence, with a 0.6 percent difference between sample and population prevalence, and a=0.05. Serological profile according to immunity (IgG reagent) was observed in 56,1% (CI95%=54.0-58.2%), with 39,2% (CI95%=37.2-41.2%) susceptible samples (non-reagent IgG and IgM), 2.5% (CI95%=1.9-3.2%) with possible infection, and an extra 2.2% (CI95%=1.3-2.1%) undefined. The serological profile was similar comparing the five health districts, despite expected socio-economic differences in their population. Comparing estimated direct costs, the laboratory and treatment routine being proposed alow for a 51% reduction for the municipal healty system, mainly due to exclusion of IgM test screening in the first sample, spriramicin use, and PCR im amniotic fluid to evaluate fetal infection. For the reference unit, the cost expected reduction was 79.5%. The high toxoplasmosis prevalence among pregnant women in piblc antenatal care in Campinas indicates a high risk for seroconversion (acute infection) / Mestrado / Tocoginecologia / Mestre em Tocoginecologia
305

Evaluación de planta mecanizada separadora de residuos solidos — Estudio de pre-factibilidad

Rodriguez González, Danilo January 2009 (has links)
No description available.
306

Pre-stressed piezoelectric actuator for micro and fine mechanical applications

Juuti, J. (Jari) 28 March 2006 (has links)
Abstract In this thesis pre-stressed piezoelectric actuators for micro and fine mechanical applications have been developed. First, RAINBOW (Reduced And INternally Biased Oxide Wafer) and thick film actuators were manufactured and their electromechanical properties were characterised. In the second part, the novel pre-stressed piezoelectric actuator PRESTO (PRE-STressed electrOactive component by using a post-fired biasing layer) was developed and its electrical and electromechanical properties were measured. Commercial piezoelectric PZT 5A and PZT 5H discs were used in the RAINBOW and PRESTO actuators and PLZT paste for thick film actuators. The pre-stressing of the PRESTO actuators was based on the sintering shrinkage and different thermal expansion coefficient of the piezoelectric disc and passive material. Dielectric LTCC tape and AgPd paste were utilized as pre-stressing media and passive layer by using lamination and screen-printing, respectively. Different active and passive layer thicknesses and electrode materials were realized in order to obtain high displacements and good load bearing capability for actuators. The PRESTO actuators showed a significantly higher coercive electric field than their bulk counterparts, but a decreased remanent polarisation. The displacement as a function of load was measured under 0.3–3 N loads and electric fields up to ±0.75 MV/m. The highest displacement of 118 μm was obtained with a 250 μm thick PZT 5H actuator (Ø 25 mm) with LTCC tape (thickness ~96 μm) as the pre-stressing material. The corresponding actuator with AgPd pre-stressing material (thickness ~33 μm) produced 63 μm displacement. Additionally, PRESTO actuators were tested with a glued steel layer in a mechanical amplifier which obtained displacements up to 1.2 mm. Effective d31 coefficients of the PRESTO actuators were derived using an analysis based on unimorph model and measured displacement data. The actuators exhibited significantly enhanced effective d31 coefficients (d31eff = -690 pm/V and d31eff = -994 pm/V for PZT 5A and 5H, respectively) comparable to the RAINBOW actuators. Mass-producible PRESTO actuators with high displacement, moderate load bearing capabilities and integration possibilities can be utilised in various micro and fine mechanical devices e.g. dosing devices, electromechanical locks, regulators, positioners vibrators, speakers, adjusters, pumps, valves, relays, dispensers, micromanipulators, etc.
307

Pre-algebra genom tiden : En jämförande innehållsanalys av grundskolans fem läroplaner med tillhörande läromedel

Kjellberg, Hanna January 2017 (has links)
No description available.
308

Paediatric schistosomiasis : diagnosis, morbidity and treatment

Wami, Welcome Mkululi January 2015 (has links)
Schistosomiasis is a major parasitic disease caused by parasitic helminths of the genus Schistosoma which affects children in Africa, with negative impacts on general health, growth and cognitive development. Infection and morbidity are controlled by treatment with the antihelminthic drug praziquantel. Preschool children (aged ≤5 years old) have been neglected both in terms of research and control, and it is only recently that the World Health Organization (WHO) recommended praziquantel treatment and the inclusion of preschool children in control programmes. However, the burden of disease in this age group still remains poorly understood, and the performance of the currently available tools for detecting infection and morbidity is still yet to be systematically evaluated. The aim of this thesis was to compare the utility of currently available tools for diagnosing S. haematobium infection and related morbidity. The initial study cohort consisted of 438 Zimbabwean children (age range: 1-10 years) who were endemically exposed. Point-of-care schistosome-related morbidity markers applicable in the field, as well as serological biomarkers (CHI3L1, CRP, ferritin, resistin and SLPI) and inflammatory cytokines (IL-4, IL-5, IL-10, IL-13 and IFN-γ) that could predict early stages of immune-mediated pathology due to schistosomiasis were measured. Using a combination of applied statistical methods, the effect of treatment on factors associated with S. haematobium exposure, infection and morbidity in children aged 1-5 years was determined and the findings compared with those observed in children aged between 6-10 years old, who are the current targets of the schistosome control programmes. In this thesis, I able to demonstrate that preschool children carried significant infection, further reiterating the need for their inclusion in control programmes. Furthermore, this study demonstrated the importance of using additional sensitive diagnostic methods as this has implications on the required intervention strategies for the targeted populations. This study further revealed that preschool children can be effectively screened for schistosome-related morbidity using the same currently available diagnostic tools applicable to older children. Urinalysis markers microhaematuria, proteinuria and albuminuria are recommended in this thesis as the best choice for rapid assessment of morbidity attributed to S. haematobium infection in the field. Additionally, it was shown that the praziquantel treatment regimens aimed at controlling schistosome infection and morbidity currently designated for primary school-aged children and older populations are applicable to preschool-aged children. The involvement of serum biomarkers and immune correlates in the biological processes of inflammation suggests that these markers can be potential early predictors of schistosome-related pathology. Further research efforts are required to establish the relationship between these biomarkers and presence of schistosome-related morbidity as measured using point-of-care indicators in larger cohorts of populations chronically exposed to schistosome infections. In summary, the findings of this thesis highlight the need for the refinement of existing diagnostic methods for accurate detection of infection and morbidity in children. This will enable appropriate and timely intervention strategies, aimed at improving the current and future health of preschool aged-children to be implemented. The findings presented here will aid researchers and other stakeholders in making informed choices about intervention tools for control programmes targeting young children.
309

The role of p53 modulation in correcting aberrant placental apoptosis in pre-eclampsia and IUGR

Sharp, Andrew January 2011 (has links)
Pre-eclampsia and intrauterine growth restriction (IUGR) are common complications of pregnancy with significant implications for mother and fetus. The exact cause is unknown, but current theories suggest that abnormal trophoblast invasion leads to placental under perfusion and hypoxia with the generation of reactive oxygen species (ROS). A result of this insult is increased trophoblast apoptosis. The cell cycle regulator p53 has been identified in increased amounts in the trophoblast in pre-eclampsia and IUGR. It is possible that modulation of this potent apoptotic signal could improve placental function, potentially offering a therapy for these presently untreatable conditions.In these studies, trophoblast apoptosis was induced with Nutlin-3, a synthetic compound which inhibits the binding of p53 to its inhibitor, Mdm2, therefore acting as a p53 activator. Treatment with Nutlin-3 induced apoptotic cell death in BeWo choriocarcinoma cells, primary trophoblast cells and placental villous explants, suggesting that p53 is intrinsic to trophoblast survival. This increase in apoptosis was associated with an increase in p53, Mdm2, p21 and Puma protein expression in BeWo cells and p21 and Puma mRNA in placental villous explants. No effect was observed in Bax expression. Co-treatment with Nutlin-3 and the p53 inhibitor Pifithrin-α reduced apoptosis to the level of control tissue in BeWo cells, primary trophoblast cells and villous explants, suggesting that reducing p53 activity improves trophoblast function.The use of hypoxia and ROS was associated with an increase in apoptosis and p21 and Puma in placental villous explants. Furthermore, the extent of apoptosis and p21 and Puma expression was reduced by co-treatment with Pifithrin-α, suggesting that the ameliorating effects of Pifithrin-α on trophoblast apoptosis are maintained following an insult from a less specific p53 activating mechanism, further supporting the continued investigation of p53 modulation as a therapeutic manipulation of placental function.Pregnant mice were exposed to Nutlin-3 to ascertain the effect of p53 over-activity on pregnancy outcome. The establishment of a model of placental dysfunction in the mouse would have allowed investigation into the effect of p53 inhibition with Pifithrin-α. Despite clear evidence of p53 modulation in maternal tissues, the decidua, no effect was observed upon pregnancy outcome or upon fetal or placental tissue. These findings suggest that the mouse placenta may not be a good model of p53 over-activity, although the exact mechanism of resistance remains unclear.In conclusion, p53 exaggeration is inducible in trophoblast with Nutlin-3, hypoxia and ROS. Furthermore, Pifithrin-α is able to reduce this effect, suggesting that the p53 pathway may be a realistic target for modulation in the placenta.
310

Analysis of Antibody-Induced Plasmodium falciparum Sporozoites Through Scanning Electron Microscopy

Bera, Sagorika 24 March 2017 (has links)
Malaria is a devastating disease that continues to affect millions of people worldwide every year. Specifically, Plasmodium falciparum is the most common human malaria parasite, particularly in sub-Saharan Africa. P. falciparum causes the most malignant and debilitating symptoms with the highest mortality and complication rates. Even with the worldwide efforts of many researchers and organizations, the road to discovering a vaccine has been difficult and challenging. Due do to the improvements in in vitro liver stage assays as well as rodent models of mammalian malaria, pre-erythrocytic stages of malaria have become a more accessible target for experimental studies. These vaccine candidates target Plasmodium sporozoites in the liver and liver stages to prevent development to the blood-stage forms, which is responsible for the debilitating symptoms of the disease. Scanning electron microscopy has been used for decades to provide insight on the morphology and topography of specimens, which cannot be seen through a light microscope. The purpose of this study was to analyze the morphology of sporozoites with some target antibodies. Sporozoites have previously shown uncharacterized appearances and development in an immunofluorescent stain at different concentrations of particular antibodies. With this further understanding on the morphological impact few of the target antibodies have on sporozoites through scanning electron microscopy, further grasp can be acquired.

Page generated in 0.1123 seconds