• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1
  • Tagged with
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Os efeitos das queimadas na Amaz?nia em n?vel celular e molecular

Alves, Nilmara de Oliveira 28 August 2014 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2015-12-04T19:34:33Z No. of bitstreams: 1 NilmaraDeOliveiraAlves_TESE.pdf: 4420508 bytes, checksum: 970409d7d94b116854a2e3e7da3725ee (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2015-12-09T23:25:19Z (GMT) No. of bitstreams: 1 NilmaraDeOliveiraAlves_TESE.pdf: 4420508 bytes, checksum: 970409d7d94b116854a2e3e7da3725ee (MD5) / Made available in DSpace on 2015-12-09T23:25:19Z (GMT). No. of bitstreams: 1 NilmaraDeOliveiraAlves_TESE.pdf: 4420508 bytes, checksum: 970409d7d94b116854a2e3e7da3725ee (MD5) Previous issue date: 2014-08-28 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq / A Amaz?nia representa mais da metade das florestas tropicais remanescentes no planeta e compreende a maior biodiversidade do mundo, correspondendo aproximadamente a 60% do territ?rio brasileiro. Entretanto, o desmatamento e as queimadas que ocorrem na regi?o t?m causado s?rios preju?zos para a popula??o que est? sendo exposta. Diante desta situa??o, o objetivo do presente estudo foi avaliar os compostos qu?micos assim como os efeitos celulares e moleculares ap?s a exposi??o ao material org?nico extra?do do material particulado menor que 10 ?m (MP10) na regi?o Amaz?nica. Com rela??o ? composi??o qu?mica, a an?lise dos n-alcanos mostrou um predom?nio da influ?ncia antr?pica no per?odo de queimadas na regi?o. Al?m disso, observou-se um predom?nio dos monossacar?deos marcadores da queima de biomassa. Tamb?m foram identificados os Hidrocarbonetos Polic?clicos Arom?ticos (HPA) e os seus derivados nas amostras coletadas na Amaz?nia. Os dados das concentra??es dos HPA permitiram calcular o BaP-equivalente e observou-se que o dibenzo(a)antraceno contribui com 83% para o potencial risco carcinog?nico. J? para o potencial risco mutag?nico, o benzo(a)pireno ? o HPA que apresenta uma maior contribui??o nesta an?lise. Pode-se destacar que o reteno foi o HPA mais abundante. Este composto foi considerado genot?xico, al?m de causar morte por necrose nas c?lulas estudadas. Nas an?lises biol?gicas, os dados mostraram que o MP10 org?nico ? capaz de causar altera??es gen?ticas tanto em c?lulas vegetais como em c?lulas do pulm?o humano. Estes danos levaram a uma parada na fase G1 no ciclo das c?lulas expostas, aumentando a express?o das prote?nas p53 e p21. Al?m disso, o MP causou morte celular por apoptose, aumentando a marca??o da histona ?-H2AX. Com resultados bem evidentes, o MP inal?vel tamb?m causou morte por necrose nas c?lulas do pulm?o humano. Diante destes resultados, ? importante enfatizar a import?ncia da redu??o e um melhor controle da queima de biomassa na regi?o Amaz?nica. Afinal, como descrito recentemente pela Organiza??o Mundial de Sa?de, pode-se afirmar que a redu??o da polui??o do ar poder? salvar milh?es de vidas. / The Amazon holds over half of the planet's remaining tropical forests and comprises the largest biodiversity in the world, accounting for approximately 60 % of the Brazilian territory. However, deforestation fires in the region causes serious problems to exposed human. The aim of this study was to evaluate the chemical compounds as well as the cellular and molecular effects after exposure to organic material extracted from particulate matter less than 10 ?m (PM10) in the Amazon region. As for the chemical composition, n-alkanes analysis showed a prevalence of anthropogenic influence during the fires in the region. In addition, there was a predominance of monosaccharides from biomass burning markers. Also, the Polycyclic Aromatic Hydrocarbons (PAH) and their derivatives have also been identified in samples collected in the Amazon. By using the PAH concentrations was possible to calculate the BaP-equivalent and it was found that the dibenz(a) anthracene contributes with 83% to potential carcinogenic risk. As for the potential mutagenic risk, the benzo (a) pyrene is the HPA that has a major contribution in this analysis. It may be noted that the retene was the most abundant PAH. This compound was genotoxic and cause death by necrosis in the human lung cells. In biological tests, the data showed that organic PM10 is capable of causing genetic damage in both plant cells and in human lung cells. This damage cause an arrest in the G1 phase of the cell cycle exposed, increasing the expression of p53 and p21. Additionally, the PM10 caused cell death by apoptosis, increasing the foci of histone ?- H2AX. Given these results, it is important to emphasize the reduction and better control of biomass burning in the Amazon region thus improving the quality of health of the population being exposed. As clearly stated recently by the World Health Organization, the reduction of air pollution could save millions of lives annually.

Page generated in 0.0926 seconds