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Papers by amanda araujo

Journal of Thermal Analysis and Calorimetry, 2007

Polyethylene/montmorillonite clay nanocomposites were obtained via direct melt intercalation. The... more Polyethylene/montmorillonite clay nanocomposites were obtained via direct melt intercalation. The clay was organically modified with four different types of quaternary ammonium salts. The objective of this work is to study the use of montmorillonite clay in the production of nanocomposites by means on rheological, mechanical and crystallization properties of nanocomposites and to compare to the properties of the matrix and PE/unmodified clay nanocomposites. In general, the tensile test showed that the yield strength and modulus of the nanocomposites are close to the pure PE. Apparently, the mixture with Dodigen salt seems to be more stable than the pure PE and PE/unmodified clay.

Jornal Brasileiro De Pneumologia, 2006

In this study, we report a case of pulmonary cryptococcosis in a patient presenting respiratory s... more In this study, we report a case of pulmonary cryptococcosis in a patient presenting respiratory symptoms and a lung mass on the chest X-ray. The patient had no concomitant diseases, was seronegative for human immunodeficiency virus and was not receiving immunosuppressive therapy of any kind. The diagnosis was confirmed through transbronchial biopsy and bronchoalveolar lavage. The patient was treated as an outpatient with fluconazole (300 mg/day for six months), evolving to clinical improvement and partial regression of the lung mass, as seen on a second chest X-ray. The current case illustrates an unusual presentation of pulmonary cryptococcosis and raises questions regarding the therapeutic approaches proposed in the literature.

Naunyn-schmiedebergs Archives of Pharmacology

(−)-α-Bisabolol is an unsaturated, optically active sesquiterpene alcohol obtained by the direct ... more (−)-α-Bisabolol is an unsaturated, optically active sesquiterpene alcohol obtained by the direct distillation of essential oil from plants such as Vanillosmopsis erythropappa and Matricaria chamomilla. (−)-α-Bisabolol has generated considerable economic interest, as it possesses a delicate floral odour and has been shown to have antiseptic and gastroprotective activities. In this study, (−)-α-bisabolol was tested in standardised rodent models by gavage administration at doses of 100 and 200 mg/kg in the models of inflammation and 25 and 50 mg/kg in the models of nociception. In the inflammatory models of paw oedema induced by carrageenan and dextran, the mice treated with (−)-α-bisabolol showed smaller oedemas compared to animals treated only with the vehicle. (−)-α-Bisabolol was capable of reducing paw oedemas induced by 5-HT but not oedemas induced by histamine. (−)-α-Bisabolol demonstrated anti-nociceptive activity in the models of visceral nociception induced by acetic acid and in the second phase of the nociception test induced by the intraplantar administration of formalin. (−)-α-Bisabolol did not have any effect in a thermal nociception model using a hot plate but was able to diminish mechanical inflammatory hypernociception evoked by carrageenan. These findings suggest that the anti-nociceptive action of (−)-α-bisabolol is not linked to a central mechanism but instead is related to the inflammatory process. (−)-α-Bisabolol was able to decrease leukocyte migration, protein extravasations and the amount of TNF-α to the peritoneal cavity in response to carrageenan. Additionally, (−)-α-bisabolol reduced neutrophil degranulation in response to phorbol-myristate-acetate. We demonstrate, for the first time, the peripheral anti-inflammatory and anti-nociceptive activities of (−)-α-bisabolol.

Journal of Inflammation, 2010

Background: The species Himatanthus drasticus is popularly known in Northeast Brazil as "janaguba... more Background: The species Himatanthus drasticus is popularly known in Northeast Brazil as "janaguba" and belongs to the family Apocynaceae. The latex collected from its stem bark is used for several purposes including antiinflammatory properties and presents among its bioactive constituents the pentacyclic triterpene lupeol. The objective of the present work was to study in vivo and in vitro the lupeol acetate (LA) isolated from the plant latex, in several models of inflammation. Methods: Male Swiss mice (25-30 g, 6-24 animals per group) were administered with LA, 30 min before the test initiation. In the evaluation of analgesic activity the formalin test was used. The anti-inflammatory activity was evaluated by the following tests: paw edema induced by carrageenan and dextran, and the carrageenan-induced neutrophil migration into peritoneal cavities. Furthermore, the effect of LA on the myeloperoxidase release (MPO, an inflammation biomarker) from human neutrophils was also determined, as well as its antioxidant potential by the DPPH assay. Results: In the formalin test, LA (10, 25 and 50 mg/kg, i.p.) inhibited both the 1 st (neurogenic, 0-5 min) and mainly the 2 nd (inflammatory, 20-25 min) phase. Naloxone completely reversed the LA effect, indicating the participation of the opioid system. LA also significantly inhibited carrageenan-and dextran-induced paw edemas, as well as the neutrophil migration to the peritoneal cavity evaluated by the carrageenan-induced pleurisia. In this model, the effect of a very low dose of LA (0.1 mg/kg) was potentiated by the same dose of pentoxifylline (PTX), a known TNF-alpha inhibitor. LA (25 and 50 μg/ml) was also very effective in inhibiting MPO released from stimulated human neutrophils, and significantly decreased the number of cells expressing iNOS activity in the paw of mice submitted to carrageenan-induced edema, suggesting a drug involvement with the NO system.

We show that for a large class of piecewise expanding maps T, the bounded p-variation observables... more We show that for a large class of piecewise expanding maps T, the bounded p-variation observables u_0 that admits an infinite sequence of bounded p-variation observables u_i satisfying u_i(x)= u_{i+1}(Tx) -u_{i+1}(x) are constant. The method of the proof consists in to find a suitable Hilbert basis for L^2(hm), where hm is the unique absolutely continuous invariant probability of T. In terms of this basis, the action of the Perron-Frobenious and the Koopan operator on L^2(hm) can be easily understood. This result generalizes earlier results by Bamon, Kiwi, Rivera-Letelier and Urzua in the case T(x)= n x mod 1, n in N-{0,1} and Lipchitizian observables u_0.

Objetivo: Identificar a ocorrência de acidentes ocupacionais em alunos de graduação da Universida... more Objetivo: Identificar a ocorrência de acidentes ocupacionais em alunos de graduação da Universidade Federal da Paraíba e analisar o conhecimento destes sobre a conduta a ser adotada. Método: Utilizou-se abordagem indutiva, com procedimento estatístico-descritivo e técnica de observação direta extensiva, por meio de questionário. A amostra foi de 168 alunos (83,6%) do Curso de Odontologia regularmente matriculados do 5º ao 10º período. Realizou-se previamente um estudo piloto com 20 alunos para garantir a validade do instrumento da pesquisa. Resultados: Observou-se que 100 (59,5%) estudantes relataram ter sofrido acidente ocupacional, existindo predomínio do gênero masculino (62%) e dos estudantes do 8º ao 10º períodos. Os acidentes superficiais foram citados por 101 acadêmicos e os percutâneos por 29, sendo a distração (24,2%), a pressa (18,9%) e a pouca experiência (15,4%) as principais causas relatadas. A agulha anestésica (19,4%) e a sonda exploradora nº5 (16,4%); a dentística (28,5%) e a cirurgia (25,1%) foram os instrumentos e clínicas mais citados, respectivamente. Aproximadamente 60% dos acidentes ocorreram durante a lavagem dos instrumentais. O uso incompleto do EPI foi observado em 80 estudantes (80%) que sofreram acidentes, enquanto o uso completo em 73,5% dos que nunca sofreram acidentes. Dos estudantes que obtiveram conhecimento prévio sobre como proceder em caso de acidentes, 90 (56,8%) responderam corretamente. Um percentual de 65,5% e 22% dos estudantes possuem imunização completa para hepatite B e tétano, respectivamente. Conclusão: A experiência com acidentes ocupacionais aumenta à medida que os acadêmicos evoluem no curso, sendo o cuidado com a biossegurança e a imunização deficientes. Os pontos críticos encontrados foram: negligência nas condutas mediatas pósacidente, lavagem do instrumental, ausência de luvas de borracha e imunização incompleta.

A Administração (português brasileiro) ou Gestão (português europeu) é a ciência social que estud... more A Administração (português brasileiro) ou Gestão (português europeu) é a ciência social que estuda e sistematiza as práticas usadas para administrar.

Journal of Applied Polymer Science, 2009

Microporous membranes were synthesized from a polymer nanocomposite material, intercalated montmo... more Microporous membranes were synthesized from a polymer nanocomposite material, intercalated montmorillonite clay/nylon 6, by an immersion–precipitation method in a water bath. This membrane was skinless and was composed of cellular pores and sheaflike crystallites, which were interwoven into a bicontinuous structure. In contrast, pure nylon 6, precipitated under the same conditions, yielded a skinned asymmetric membrane. The X-ray diffraction patterns showed that the nanocomposites and the membranes exhibited exfoliated structures. By differential scanning calorimetry, it was observed that the clay probably acted as a reinforcing filler, increasing the crystallinity degree of the nanocomposites, but it was practically unchanged in the membranes. Through photomicrographs obtained by scanning electron microscopy, it was possible to verify that all the membranes exhibited an asymmetric morphology with a well-defined porous structure and a tight skin with a cellular sublayer. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Journal of Thermal Analysis and Calorimetry, 2007

Polyethylene/montmorillonite clay nanocomposites were obtained via direct melt intercalation. The... more Polyethylene/montmorillonite clay nanocomposites were obtained via direct melt intercalation. The clay was organically modified with four different types of quaternary ammonium salts. The objective of this work is to study the use of montmorillonite clay in the production of nanocomposites by means on rheological, mechanical and crystallization properties of nanocomposites and to compare to the properties of the matrix and PE/unmodified clay nanocomposites. In general, the tensile test showed that the yield strength and modulus of the nanocomposites are close to the pure PE. Apparently, the mixture with Dodigen salt seems to be more stable than the pure PE and PE/unmodified clay.

Jornal Brasileiro De Pneumologia, 2006

In this study, we report a case of pulmonary cryptococcosis in a patient presenting respiratory s... more In this study, we report a case of pulmonary cryptococcosis in a patient presenting respiratory symptoms and a lung mass on the chest X-ray. The patient had no concomitant diseases, was seronegative for human immunodeficiency virus and was not receiving immunosuppressive therapy of any kind. The diagnosis was confirmed through transbronchial biopsy and bronchoalveolar lavage. The patient was treated as an outpatient with fluconazole (300 mg/day for six months), evolving to clinical improvement and partial regression of the lung mass, as seen on a second chest X-ray. The current case illustrates an unusual presentation of pulmonary cryptococcosis and raises questions regarding the therapeutic approaches proposed in the literature.

Naunyn-schmiedebergs Archives of Pharmacology

(−)-α-Bisabolol is an unsaturated, optically active sesquiterpene alcohol obtained by the direct ... more (−)-α-Bisabolol is an unsaturated, optically active sesquiterpene alcohol obtained by the direct distillation of essential oil from plants such as Vanillosmopsis erythropappa and Matricaria chamomilla. (−)-α-Bisabolol has generated considerable economic interest, as it possesses a delicate floral odour and has been shown to have antiseptic and gastroprotective activities. In this study, (−)-α-bisabolol was tested in standardised rodent models by gavage administration at doses of 100 and 200 mg/kg in the models of inflammation and 25 and 50 mg/kg in the models of nociception. In the inflammatory models of paw oedema induced by carrageenan and dextran, the mice treated with (−)-α-bisabolol showed smaller oedemas compared to animals treated only with the vehicle. (−)-α-Bisabolol was capable of reducing paw oedemas induced by 5-HT but not oedemas induced by histamine. (−)-α-Bisabolol demonstrated anti-nociceptive activity in the models of visceral nociception induced by acetic acid and in the second phase of the nociception test induced by the intraplantar administration of formalin. (−)-α-Bisabolol did not have any effect in a thermal nociception model using a hot plate but was able to diminish mechanical inflammatory hypernociception evoked by carrageenan. These findings suggest that the anti-nociceptive action of (−)-α-bisabolol is not linked to a central mechanism but instead is related to the inflammatory process. (−)-α-Bisabolol was able to decrease leukocyte migration, protein extravasations and the amount of TNF-α to the peritoneal cavity in response to carrageenan. Additionally, (−)-α-bisabolol reduced neutrophil degranulation in response to phorbol-myristate-acetate. We demonstrate, for the first time, the peripheral anti-inflammatory and anti-nociceptive activities of (−)-α-bisabolol.

Journal of Inflammation, 2010

Background: The species Himatanthus drasticus is popularly known in Northeast Brazil as "janaguba... more Background: The species Himatanthus drasticus is popularly known in Northeast Brazil as "janaguba" and belongs to the family Apocynaceae. The latex collected from its stem bark is used for several purposes including antiinflammatory properties and presents among its bioactive constituents the pentacyclic triterpene lupeol. The objective of the present work was to study in vivo and in vitro the lupeol acetate (LA) isolated from the plant latex, in several models of inflammation. Methods: Male Swiss mice (25-30 g, 6-24 animals per group) were administered with LA, 30 min before the test initiation. In the evaluation of analgesic activity the formalin test was used. The anti-inflammatory activity was evaluated by the following tests: paw edema induced by carrageenan and dextran, and the carrageenan-induced neutrophil migration into peritoneal cavities. Furthermore, the effect of LA on the myeloperoxidase release (MPO, an inflammation biomarker) from human neutrophils was also determined, as well as its antioxidant potential by the DPPH assay. Results: In the formalin test, LA (10, 25 and 50 mg/kg, i.p.) inhibited both the 1 st (neurogenic, 0-5 min) and mainly the 2 nd (inflammatory, 20-25 min) phase. Naloxone completely reversed the LA effect, indicating the participation of the opioid system. LA also significantly inhibited carrageenan-and dextran-induced paw edemas, as well as the neutrophil migration to the peritoneal cavity evaluated by the carrageenan-induced pleurisia. In this model, the effect of a very low dose of LA (0.1 mg/kg) was potentiated by the same dose of pentoxifylline (PTX), a known TNF-alpha inhibitor. LA (25 and 50 μg/ml) was also very effective in inhibiting MPO released from stimulated human neutrophils, and significantly decreased the number of cells expressing iNOS activity in the paw of mice submitted to carrageenan-induced edema, suggesting a drug involvement with the NO system.

We show that for a large class of piecewise expanding maps T, the bounded p-variation observables... more We show that for a large class of piecewise expanding maps T, the bounded p-variation observables u_0 that admits an infinite sequence of bounded p-variation observables u_i satisfying u_i(x)= u_{i+1}(Tx) -u_{i+1}(x) are constant. The method of the proof consists in to find a suitable Hilbert basis for L^2(hm), where hm is the unique absolutely continuous invariant probability of T. In terms of this basis, the action of the Perron-Frobenious and the Koopan operator on L^2(hm) can be easily understood. This result generalizes earlier results by Bamon, Kiwi, Rivera-Letelier and Urzua in the case T(x)= n x mod 1, n in N-{0,1} and Lipchitizian observables u_0.

Objetivo: Identificar a ocorrência de acidentes ocupacionais em alunos de graduação da Universida... more Objetivo: Identificar a ocorrência de acidentes ocupacionais em alunos de graduação da Universidade Federal da Paraíba e analisar o conhecimento destes sobre a conduta a ser adotada. Método: Utilizou-se abordagem indutiva, com procedimento estatístico-descritivo e técnica de observação direta extensiva, por meio de questionário. A amostra foi de 168 alunos (83,6%) do Curso de Odontologia regularmente matriculados do 5º ao 10º período. Realizou-se previamente um estudo piloto com 20 alunos para garantir a validade do instrumento da pesquisa. Resultados: Observou-se que 100 (59,5%) estudantes relataram ter sofrido acidente ocupacional, existindo predomínio do gênero masculino (62%) e dos estudantes do 8º ao 10º períodos. Os acidentes superficiais foram citados por 101 acadêmicos e os percutâneos por 29, sendo a distração (24,2%), a pressa (18,9%) e a pouca experiência (15,4%) as principais causas relatadas. A agulha anestésica (19,4%) e a sonda exploradora nº5 (16,4%); a dentística (28,5%) e a cirurgia (25,1%) foram os instrumentos e clínicas mais citados, respectivamente. Aproximadamente 60% dos acidentes ocorreram durante a lavagem dos instrumentais. O uso incompleto do EPI foi observado em 80 estudantes (80%) que sofreram acidentes, enquanto o uso completo em 73,5% dos que nunca sofreram acidentes. Dos estudantes que obtiveram conhecimento prévio sobre como proceder em caso de acidentes, 90 (56,8%) responderam corretamente. Um percentual de 65,5% e 22% dos estudantes possuem imunização completa para hepatite B e tétano, respectivamente. Conclusão: A experiência com acidentes ocupacionais aumenta à medida que os acadêmicos evoluem no curso, sendo o cuidado com a biossegurança e a imunização deficientes. Os pontos críticos encontrados foram: negligência nas condutas mediatas pósacidente, lavagem do instrumental, ausência de luvas de borracha e imunização incompleta.

A Administração (português brasileiro) ou Gestão (português europeu) é a ciência social que estud... more A Administração (português brasileiro) ou Gestão (português europeu) é a ciência social que estuda e sistematiza as práticas usadas para administrar.

Journal of Applied Polymer Science, 2009

Microporous membranes were synthesized from a polymer nanocomposite material, intercalated montmo... more Microporous membranes were synthesized from a polymer nanocomposite material, intercalated montmorillonite clay/nylon 6, by an immersion–precipitation method in a water bath. This membrane was skinless and was composed of cellular pores and sheaflike crystallites, which were interwoven into a bicontinuous structure. In contrast, pure nylon 6, precipitated under the same conditions, yielded a skinned asymmetric membrane. The X-ray diffraction patterns showed that the nanocomposites and the membranes exhibited exfoliated structures. By differential scanning calorimetry, it was observed that the clay probably acted as a reinforcing filler, increasing the crystallinity degree of the nanocomposites, but it was practically unchanged in the membranes. Through photomicrographs obtained by scanning electron microscopy, it was possible to verify that all the membranes exhibited an asymmetric morphology with a well-defined porous structure and a tight skin with a cellular sublayer. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009