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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Avaliação da exposição ao ²²²Rn nas cavernas do Parque Estadual Turístico do Alto Ribeira (PETAR) / 222Rn exposure assessment in the caves of Parque Estadual Turístico do Alto Ribeira (PETAR)

Simone Alberigi 10 July 2006 (has links)
No presente trabalho foram determinadas as concentrações de radônio em seis cavernas do Parque Estadual Turístico do Alto Ribeira (PETAR) e foi estimada a dose efetiva anual recebida pelos guias turísticos da região. O PETAR apresenta quatro núcleos de visitação: Santana, Ouro Grosso, Caboclos e Casa de Pedra e recebe anualmente cerca de 40 mil visitantes. As cavernas escolhidas foram Couto, Água Suja, Laje Branca, Morro Preto e Santana, do núcleo Santana e a caverna Alambari de Baixo do núcleo Ouro Grosso, por receberem o maior número de turistas. Os níveis de radônio foram determinados utilizando detectores de traços nucleares do estado sólido Makrofol E expostos trimestralmente por um período de 26 meses, entre Outubro de 2003 e Novembro de 2005. As concentrações de 222Rn variaram na faixa de 153 Bq.m-3 a 6607 Bq.m-3, sendo observado que, de uma maneira geral, os níveis de radônio diminuem nos períodos frios. A dose efetiva anual, considerando os cenários mais realistas, com média geométrica das concentrações, fator de equilíbrio 0,5 e tempo de exposição anual para cada caverna, variou entre 0,2 mSv.a-1 para a caverna Couto, bastante ventilada e 4,0 mSv.a-1 para a caverna Santana, a mais visitada, com galerias sem comunicação externa. Para o pior cenário, com média aritmética das concentrações, fator de equilíbrio 1 e tempo de exposição anual para todas as cavernas, a dose efetiva anual total foi 16,1 mSv.a-1. Todas as estimativas da dose efetiva anual estão abaixo de 20 mSv.a-1, sugerido como o valor limite para dose efetiva anual para exposição ocupacional pela Comissão Internacional de Proteção Radiológica (ICRP 60, 1990). / In the present work, radon concentrations in six caves of PETAR - Parque Estadual Turístico do Alto Ribeira (High Ribeira River Turistic State Park) were carried out with Makrofol E solid state nuclear track detectors (SSNTD) and used to assess the annual effective dose received by regional tour guides. The park has four visitation centers: Santana, Ouro Grosso, Caboclos e Casa de Pedra and receives nearly 40,000 people annually. The caves evaluated were Couto, Água Suja, Laje Branca, Morro Preto and Santana, from Santana center and Alambari de Baixo from Ouro Grosso center, for being the most frequently visited caves. The exposure period of the SSNTD was, at least, three months, over a period of 26 months, from October 2003 to November 2005. The 222Rn concentrations lay in a range from 153 Bq.m-3 to 6607 Bq.m-3 and we observed that, in general, for chilly weather, the radon levels decrease. The annual effective dose, considering the most realistic scenario, with geometric mean concentrations, an equilibrium factor of 0.5 and annual exposure time for each cave, varied from 0.2 mSv.a-1 for the Couto cave, strongly ventilated, to 4.0 mSv.a-1 for the Santana cave, the most frequently visited and no external communication. For the worst scenario, with arithmetic mean concentrations, equilibrium factor 1 and annual exposure time for all caves, the annual effective dose was 16.1 mSv.a-1. All assessed effective doses received by the tour guides are bellow 20 mSv.a-1, suggested as an annual effective dose limit for occupational exposure by the International Commission of Radiological Protection (ICRP 60, 1990).
82

Avaliação da exposição ao ²²²Rn nas cavernas do Parque Estadual Turístico do Alto Ribeira (PETAR) / 222Rn exposure assessment in the caves of Parque Estadual Turístico do Alto Ribeira (PETAR)

Alberigi, Simone 10 July 2006 (has links)
No presente trabalho foram determinadas as concentrações de radônio em seis cavernas do Parque Estadual Turístico do Alto Ribeira (PETAR) e foi estimada a dose efetiva anual recebida pelos guias turísticos da região. O PETAR apresenta quatro núcleos de visitação: Santana, Ouro Grosso, Caboclos e Casa de Pedra e recebe anualmente cerca de 40 mil visitantes. As cavernas escolhidas foram Couto, Água Suja, Laje Branca, Morro Preto e Santana, do núcleo Santana e a caverna Alambari de Baixo do núcleo Ouro Grosso, por receberem o maior número de turistas. Os níveis de radônio foram determinados utilizando detectores de traços nucleares do estado sólido Makrofol E expostos trimestralmente por um período de 26 meses, entre Outubro de 2003 e Novembro de 2005. As concentrações de 222Rn variaram na faixa de 153 Bq.m-3 a 6607 Bq.m-3, sendo observado que, de uma maneira geral, os níveis de radônio diminuem nos períodos frios. A dose efetiva anual, considerando os cenários mais realistas, com média geométrica das concentrações, fator de equilíbrio 0,5 e tempo de exposição anual para cada caverna, variou entre 0,2 mSv.a-1 para a caverna Couto, bastante ventilada e 4,0 mSv.a-1 para a caverna Santana, a mais visitada, com galerias sem comunicação externa. Para o pior cenário, com média aritmética das concentrações, fator de equilíbrio 1 e tempo de exposição anual para todas as cavernas, a dose efetiva anual total foi 16,1 mSv.a-1. Todas as estimativas da dose efetiva anual estão abaixo de 20 mSv.a-1, sugerido como o valor limite para dose efetiva anual para exposição ocupacional pela Comissão Internacional de Proteção Radiológica (ICRP 60, 1990). / In the present work, radon concentrations in six caves of PETAR - Parque Estadual Turístico do Alto Ribeira (High Ribeira River Turistic State Park) were carried out with Makrofol E solid state nuclear track detectors (SSNTD) and used to assess the annual effective dose received by regional tour guides. The park has four visitation centers: Santana, Ouro Grosso, Caboclos e Casa de Pedra and receives nearly 40,000 people annually. The caves evaluated were Couto, Água Suja, Laje Branca, Morro Preto and Santana, from Santana center and Alambari de Baixo from Ouro Grosso center, for being the most frequently visited caves. The exposure period of the SSNTD was, at least, three months, over a period of 26 months, from October 2003 to November 2005. The 222Rn concentrations lay in a range from 153 Bq.m-3 to 6607 Bq.m-3 and we observed that, in general, for chilly weather, the radon levels decrease. The annual effective dose, considering the most realistic scenario, with geometric mean concentrations, an equilibrium factor of 0.5 and annual exposure time for each cave, varied from 0.2 mSv.a-1 for the Couto cave, strongly ventilated, to 4.0 mSv.a-1 for the Santana cave, the most frequently visited and no external communication. For the worst scenario, with arithmetic mean concentrations, equilibrium factor 1 and annual exposure time for all caves, the annual effective dose was 16.1 mSv.a-1. All assessed effective doses received by the tour guides are bellow 20 mSv.a-1, suggested as an annual effective dose limit for occupational exposure by the International Commission of Radiological Protection (ICRP 60, 1990).
83

Occupational exposure to radon in a South African platinum mine / M. Schoonhoven.

Schoonhoven, Martin January 2012 (has links)
Background: The Platinum mining operations in South Africa mining platinum containing ore from areas where variable amounts of uranium are found, leading to the possibility of occupational exposure to the radioactive disintegration products of Uranium-238 and in particular the gas Radon-222. No scientific data is available for occupational exposure to Radon-222 in South African platinum mining operations. Objective: To determine the risk of occupational exposure to the radioactive disintegration products of naturally occurring Radon-222 gas in a South African platinum mine. Design: Quantitative sampling (personal and static) to establish baseline data on exposure to radioactive disintegration products of naturally occurring Radon-222 gas in a underground South African platinum mine. Setting: The Bafokeng Rasimone platinum mine located 30 km North West of Rustenburg in the Bushveld complex in the North West Province of South Africa. Study subjects: One hundred and seventy four potentially highest exposed underground employees and one hundred and twelve static underground samples were sampled. Method: Personal and area samples were taken on selected employees and in locations using RGM samplers using CR-39 plastic as a detection medium. Employees were selected to sample the highest exposed occupations and static samples were located to sample returning air from levels underneath the sampling point before it is exhausted to the above ground atmosphere. After analysis by an accredited laboratory, the results were converted to exposure following the National Council on Radiation Protection-78 methodology. Main outcome measures: Quantify the relative risks of potentially highest exposed employee`s exposure to the radioactive disintegration products of naturally occurring Radon-222 gas in underground working areas in milliSievert per year. Results: The mean reference background exposure averaged 0.6168 mSv/a with underground personal exposure averaging 0.6808 mSv/a, and underground static exposure averaging 0.8726 mSv/a. These values are substantially below the 50 mSv/a Occupational Exposure Limit, and only pose a slightly elevated risk for the development of lung cancer above the normal back-ground exposure. Mining Team leaders and rock drill operators were identified as the potentially highest exposed employees due to the close proximity to the working face, large amounts of time spent close to the working face and the lower ventilation volumes at the working face, with Team leaders having the highest exposure of the sampled occupations with a average of 1.16 mSv/a. Conclusions: Occupational exposure to radioactive disintegration products of naturally occurring Radon-222 gas in the underground air of a South African platinum mine does not pose a significant risk to the health of employees working in the platinum mine. / Thesis (MSc (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2013.
84

Occupational exposure to radon in a South African platinum mine / M. Schoonhoven.

Schoonhoven, Martin January 2012 (has links)
Background: The Platinum mining operations in South Africa mining platinum containing ore from areas where variable amounts of uranium are found, leading to the possibility of occupational exposure to the radioactive disintegration products of Uranium-238 and in particular the gas Radon-222. No scientific data is available for occupational exposure to Radon-222 in South African platinum mining operations. Objective: To determine the risk of occupational exposure to the radioactive disintegration products of naturally occurring Radon-222 gas in a South African platinum mine. Design: Quantitative sampling (personal and static) to establish baseline data on exposure to radioactive disintegration products of naturally occurring Radon-222 gas in a underground South African platinum mine. Setting: The Bafokeng Rasimone platinum mine located 30 km North West of Rustenburg in the Bushveld complex in the North West Province of South Africa. Study subjects: One hundred and seventy four potentially highest exposed underground employees and one hundred and twelve static underground samples were sampled. Method: Personal and area samples were taken on selected employees and in locations using RGM samplers using CR-39 plastic as a detection medium. Employees were selected to sample the highest exposed occupations and static samples were located to sample returning air from levels underneath the sampling point before it is exhausted to the above ground atmosphere. After analysis by an accredited laboratory, the results were converted to exposure following the National Council on Radiation Protection-78 methodology. Main outcome measures: Quantify the relative risks of potentially highest exposed employee`s exposure to the radioactive disintegration products of naturally occurring Radon-222 gas in underground working areas in milliSievert per year. Results: The mean reference background exposure averaged 0.6168 mSv/a with underground personal exposure averaging 0.6808 mSv/a, and underground static exposure averaging 0.8726 mSv/a. These values are substantially below the 50 mSv/a Occupational Exposure Limit, and only pose a slightly elevated risk for the development of lung cancer above the normal back-ground exposure. Mining Team leaders and rock drill operators were identified as the potentially highest exposed employees due to the close proximity to the working face, large amounts of time spent close to the working face and the lower ventilation volumes at the working face, with Team leaders having the highest exposure of the sampled occupations with a average of 1.16 mSv/a. Conclusions: Occupational exposure to radioactive disintegration products of naturally occurring Radon-222 gas in the underground air of a South African platinum mine does not pose a significant risk to the health of employees working in the platinum mine. / Thesis (MSc (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2013.
85

Avaliação da exposição ao sup(222)Rn nas cavernas do Parque Estadual Turístico do Alto Ribeira (PETAR)

ALBERIGI, SIMONE 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:51:59Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:57:00Z (GMT). No. of bitstreams: 0 / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
86

Avaliação da Anexina A1, FPR1, FPR2 e miRNAs em adenocarcinoma gástrico / Evaluation of Annexin A1, FPR1, FPR2 and miRNAs in gastric adenocarcinoma

Stuchi, Nathália Maciel Maniezzo [UNESP] 31 May 2016 (has links)
Submitted by NATHÁLIA MACIEL MANIEZZO STUCHI null (nmmbiomedica@hotmail.com) on 2016-07-28T14:13:21Z No. of bitstreams: 1 Tese capa dura.pdf: 5464428 bytes, checksum: f53c801765e2d85e4f507ebaaebe4625 (MD5) / Approved for entry into archive by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br) on 2016-07-28T15:52:03Z (GMT) No. of bitstreams: 1 stuchi_nmm_dr_sjrp.pdf: 5464428 bytes, checksum: f53c801765e2d85e4f507ebaaebe4625 (MD5) / Made available in DSpace on 2016-07-28T15:52:03Z (GMT). No. of bitstreams: 1 stuchi_nmm_dr_sjrp.pdf: 5464428 bytes, checksum: f53c801765e2d85e4f507ebaaebe4625 (MD5) Previous issue date: 2016-05-31 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Apesar do declínio da incidência, o câncer gástrico ocupa ainda a terceira posição em causa de morte por câncer no mundo, tendo como principal fator de risco a bactéria Helicobacter pylori. Esta bactéria pode levar a uma inflamação persistente através da produção de citocinas pró-inflamatórias e de espécies reativas de oxigênio e nitrogênio, estimulando a proliferação celular bem como outros processos envolvidos na carcinogênese. Ainda envolvidos nestes processos tem sido observada a participação de microRNAs, que exercem papel importante na regulação pós-transcricional, influenciando processos fisiológicos normais da célula bem como aqueles ligados às doenças, como por exemplo o câncer gástrico. Alguns miRNAs podem atuar como oncogenes, genes supressores de tumor e biomarcadores para diversas patologias, podendo alvejar genes relacionados com inflamação e câncer como o gene ANXA1 (Anexina-A1). A Anexina-A1 é uma proteína anti-inflamatória e com ação anti-proliferativa, que se liga à receptores do tipo formil peptídeo como por exemplo FPR1 e FPR2, ambos sabidamente relacionados com a progressão de doenças como o câncer. Desta forma o presente trabalho teve como objetivos avaliar a expressão da proteína Anexina A1 e seus receptores FPR1 e FPR2, bem como avaliar a expressão do RNAm da ANXA1 e de miRNAs que possam modular a expressão desse gene (hsa-mir-27a, hsa-mir-196a e hsa-mir-222) em adenocarcinoma gástrico e correlacionar estes resultados com os aspectos clínico-patológicos. Foram avaliadas 31 amostras de adenocarcinoma gástrico, assim como as regiões metaplásica ou normal adjacentes ao tumor. A quantificação relativa (RQ) do RNAm da ANXA1 e miRNAs foi realizada por PCR quantitativo em tempo real utilizando ensaio TaqMan, e a expressão proteica da AnxA1, FPR1 e FPR2 por imuno-histoquímica e análise densitométrica. Em relação à expressão gênica relativa foram observados o aumento da expressão da ANXA1 nos tumores (RQ=1,374; p<0,001), assim como do miR-196a que apresentou aumento de expressão tanto no tecido metaplásico (RQ= 4,784; p=0,0016) e tumoral (RQ=16,99; p< 0,001) em relação ao tecido normal. O miR-27a não se apresentou diferencialmente expresso nos diferentes tecidos e houve diminuição da expressão do miR-222 (RQ=0,687; p=0,01) no tecido tumoral em relação ao tecido normal. Apenas o miR-196a e a ANXA1 apresentaram correlação significantemente inversa (r= -0,55; p=0,003), e este miRNA foi o único que apresentou associação com o sexo feminino, devido aumento de expressão em mulheres. Quando se comparou a expressão relativa aos parâmetros clínico-patológicos e tumorais não foram encontradas diferenças significativas. Quanto à expressão proteica o FPR2 não apresentou marcação no tecido normal, metaplásico e tumoral. Contudo a AnxA1 e FPR1 apresentaram imunomarcação positiva amplamente distribuída no tecido tumoral e positivamente correlacionados tanto no epitélio (r=0,87; p<0,0001) como estroma (r=0,62; p=0,004). Portanto, nossos resultados sugerem que a ANXA1 é modulada pelo miR-196a em câncer gástrico, e evidenciam que tanto a AnxA1 como o FPR1 também estão envolvidos no processo de carcinogênese gástrica. Tais achados podem abrir possibilidades para futuros estudos sobre novos alvos terapêuticos já que AnxA1 e FPR1 são possíveis alvos farmacológicos, e as terapias baseadas em microRNAs tem sido amplamente pesquisadas. / Gastric cancer still ranks third in cause of cancer death worldwide, despite the decline in its incidence, being Helicobacter pylori the main risk factor for this disease. This bacterium can lead to persistent inflammation via the production of proinflammatory cytokines and reactive oxygen and nitrogen species, stimulating cell proliferation and other processes involved in carcinogenesis. Still involved in this process, it has been observed the participation of miRNAs, which play an important role in post- transcriptional regulation, influencing normal physiological processes of the cell as well as those linked to diseases such as gastric cancer. Some miRNAs can act as oncogenes, tumor suppressor genes and biomarkers for various diseases, can targetting genes linked to inflammation and cancer such as ANXA1 gene (Annexin A1). Annexin A1 is an anti-inflammatory protein with anti-proliferative action that binds to formyl peptide receptors such as, FPR1 and FPR2, both known to be related to the progression of diseases such as cancer. Thus, the present study aimed to evaluate the expression of Annexin A1, FPR1 and FPR2 receptors, and the expression of mRNA ANXA1 and miRNAs (hsa-mir-27a, hsa-mir-196a and hsa-miR 222) in gastric adenocarcinoma, also correlate these results to the clinicopathological features. 31 adenocarcinoma samples were evaluated, as well as normal or metaplastic region adjacent to the tumor. Relative quantification (RQ) of miRNA and mRNA ANXA1 was evaluated by TaqMan assay and protein expression AnxA1, FPR1 and FPR2 by immunohistochemistry and densitometry analysis. Regarding the relative expression the following results were observed, increased expression in tumors of ANXA1 (RQ = 1.374; p < 0.001) and miR- 196a that showed increased expression it he metaplastic tissue (RQ = 4.784; p = 0.0016) and tumor (RQ = 16.99; p < 0.001) compared to normal tissue. The miR- 27a did not appear differentially expressed in different tissues and there was a decrease of miR -222 expression (RQ = 0.687; p = 0.01) in tumor tissue compared to normal tissue. Only the miR-196a and ANXA1 presented a significant inverse correlation (r = -0.55; p = 0.003), and this miRNA was the only one that showed association to female gender, due to increased expression in women when comparing the relative expression to clinicopathological parameters and tumor features. The FPR2 was not expressed in normal, metaplasic and tumor tissue. However, the AnxA1 and FPR1 were widely distributed positive immunostaining in tumor tissue and positively correlated both in the epithelium (r = 0.87 ; p < 0.0001) and stromal (r = 0.62 ; p = 0.004). Thus, our results suggest that ANXA1 is modulated by miR-196a in gastric cancer, and evidencing that both AnxA1 and FPR1 are also involved in gastric carcinogenesis process. These data open the possibility for future studies on new therapeutic targets since AnxA1 and FPR1 are adjustable pharmacological targets, and microRNAs ` therapies have been widely researched. / FAPESP: 2012/15036-8 / CNPq: 474776/2013-1
87

Avaliação da exposição ao sup(222)Rn nas cavernas do Parque Estadual Turístico do Alto Ribeira (PETAR)

ALBERIGI, SIMONE 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:51:59Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:57:00Z (GMT). No. of bitstreams: 0 / No presente trabalho foram determinadas as concentrações de radônio em seis cavernas do Parque Estadual Turístico do Alto Ribeira (PETAR) e foi estimada a dose efetiva anual recebida pelos guias turísticos da região. O PETAR apresenta quatro núcleos de visitação: Santana, Ouro Grosso, Caboclos e Casa de Pedra e recebe anualmente cerca de 40 mil visitantes. As cavernas escolhidas foram Couto, Água Suja, Laje Branca, Morro Preto e Santana, do núcleo Santana e a caverna Alambari de Baixo do núcleo Ouro Grosso, por receberem o maior número de turistas. Os níveis de radônio foram determinados utilizando detectores de traços nucleares do estado sólido Makrofol E expostos trimestralmente por um período de 26 meses, entre Outubro de 2003 e Novembro de 2005. As concentrações de 222Rn variaram na faixa de 153 Bq.m-3 a 6607 Bq.m-3, sendo observado que, de uma maneira geral, os níveis de radônio diminuem nos períodos frios. A dose efetiva anual, considerando os cenários mais realistas, com média geométrica das concentrações, fator de equilíbrio 0,5 e tempo de exposição anual para cada caverna, variou entre 0,2 mSv.a-1 para a caverna Couto, bastante ventilada e 4,0 mSv.a-1 para a caverna Santana, a mais visitada, com galerias sem comunicação externa. Para o pior cenário, com média aritmética das concentrações, fator de equilíbrio 1 e tempo de exposição anual para todas as cavernas, a dose efetiva anual total foi 16,1 mSv.a-1. Todas as estimativas da dose efetiva anual estão abaixo de 20 mSv.a-1, sugerido como o valor limite para dose efetiva anual para exposição ocupacional pela Comissão Internacional de Proteção Radiológica (ICRP 60, 1990). / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
88

Action of CDK Inhibitor PHA-848125 in ER-negative Breast Cancer with MicroRNA-221/222 Overexpression

Cheung, Douglas Guy January 2017 (has links)
No description available.
89

A search for superdeformed and hyperdeformed states in '2'2'2Th and '2'3'2U

Hawcroft, Deborah January 2000 (has links)
No description available.
90

Origin and evolution of ureilite vein metal - Fe, Ni, Co and Ni-isotope systematics of ureilite vein metal and ureilite silicates

Gabriel, Aron David 30 October 2009 (has links)
No description available.

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