963 resultados para irreversible


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The development of more selective and sensitive analytical methods is of great importance in different areas of knowledge, covering, for example, food, biotechnological, environmental and pharmaceutical sectors. The study aimed to employ the technique electroanalytical differential pulse voltammetry (DPV) as an innovative and promising alternative for identification and quantification of organic compounds. The organic compounds were investigated in this study oxalic acid (OA) and folic acid (FA). The electrochemical oxidation of oxalic acid has been extensively studied as a model reaction in the boundary between the organic and inorganic electrochemistry. Since the AF, an essential vitamin for cell multiplication in all tissues, which is essential for DNA synthesis. The AF has been investigated using analytical techniques, liquid chromatography and molecular absorption spectrophotometry. The results obtained during the experimental procedure indicated that the process of electrochemical oxidation of oxalic acid is strongly dependent on the nature of the anode material and the oxidation mechanism, which affects their detection. Efficient removal was observed in Ti/PbO2 anodes, graphite, BDD and Pt 90, 85, 80 and 78% respectively. It was also shown that the DPV employing glassy carbon electrode offers a fast, simple, reliable and economical way to determine the AO during the process of electrochemical oxidation. Furthermore, electroanalytical methods are more expensive than commonly used chromatographic analysis and other instrumental methods involving toxic reagents and higher cost. Compared with the classical method of titration and DPV could be a good fit, confidence intervals and detection limits confirming the applicability of electroanalytical technique for monitoring the degradation of oxalic acid. For the study of AF was investigated the electrocatalytic activity of the carbon paste electrode for identification and quantification in pharmaceutical formulations by applying the DPV. The results obtained during the experimental procedure showed an irreversible oxidation peak at 9.1 V characteristic of FA. The carbon paste sensor showed low detection limit of 5.683×10−8 mol L-1 reducing matrix effects. The spectrophotometric analysis showed lower concentrations of HF compared with those obtained by HPLC and DPV. The levels of AF were obtained according to the methodology proposed by the Brazilian Pharmacopoeia. The electroanalytical method (DPV) proposed is cheaper than GC analysis commonly used by the pharmaceutical industry. The results demonstrated the potential of these electroanalytical techniques for future applications in environmental, chemical and biological sensors

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Police officers are exposed to impact noise coming from firearms, which may cause irreversible injuries to the hearing system.Aim: To evaluate the noise exposure in shooting stands during gunfire exercises, to analyze the acoustic impact of the noise produced by the firearms and to associate it with tonal audiometry results.Study design: Cross-sectional.Materials and methods: To measure noise intensity we used a digital sound level meter, and the acoustic analysis was carried out by means of the oscillations and cochlear response curves provided by the Praat software. 30 police officers were selected (27 males and 3 females).Results: The peak level measured was 113.1 dB(C) from a .40 pistol and 116.8 dB(C) for a .38 revolver. The values obtained for oscillation and Praat was 17.9 +/- 0.3 Barks, corresponding to the rate of 4,120 and 4,580 Hz. Audiometry indicated greater hearing loss at 4,000Hz in 86.7% of the cases.Conclusion: With the acoustic analysis it was possible to show cause and effect between the main areas of energy excitation of the cochlea (Praat cochlear response curve) and the frequencies of low hearing acuity.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Trata-se de um artigo que comenta sobre a real importância do Termo de Consentimento Informado na prática médica. Este documento tem sido cada vez mais usado como uma prática defensiva, a fim de constituir provas para defesa de um eventual processo judicial de responsabilidade médica, desvirtuando assim a idéia original, que seria a de respeitar a autonomia do paciente e delimitar a responsabilidade médica. O documento tem como objetivo mostrar que o médico cumpriu com seu dever de informar. Seu grande valor reside nos casos onde existam riscos de danos irreversíveis ao paciente. Conclui-se, porém, que um prontuário bem elaborado onde se inclui o registro das informações que foram transmitidas, bem como o grau de participação dos pacientes e seus familiares nas decisões terapêuticas, também deve ter valor ético e jurídico semelhante do TCI.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

O presente estudo teve como objetivo o registro e a apresentação de trabalhos realizados no Brasil nos últimos 40 anos, relacionados com a investigação sobre a deficiência de vitamina A. Esta deficiência tem sido diagnosticada por um ou mais dos seguintes critérios: ingestão deficiente de alimentos fontes de vitamina A, exame clínico, níveis séricos de retinol abaixo dos aceitos como normais, concentração hepática de retinol, teste de adaptação ao escuro e corante de Rosa Bengala. A deficiência foi diagnosticada em grupos populacionais de vários Estados e capitais brasileiras em cidades grandes e pequenas e em zonas rurais. A maioria dos trabalhos foi desenvolvida em grupos populacionais de baixa renda. Quanto às conseqüências clínicas, relataram-se achados de sinais oculares leves, como cegueira noturna, manchas de Bitot e xerose conjuntival, encontrados principalmente na Região Nordeste. Alguns autores observaram, em menor número de casos, lesões graves, como lesões corneanas e ceratomalácia. Trabalhos da última década indicaram associação entre a hipovitaminose A e o aumento da morbidade e mortalidade, principalmente em crianças pré-escolares.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The study carried out in the environment of Maracajaú reef an São Roque channel, had as main objective to analyze the characteristics of sediments active locally expressed in the grains, through collections of sediments in the field, technical processing and data analyzes of sediments. Data processing were made on three main aspects: biotic composition, concentration of calcium carbonate and particle size of the sediment. Differences between the sediments of the reefs and channel were observed. It was emphasized the contribution of algae limestone in the production of carbonate, with some influence of foraminifera near the coast. The particle size distribution presented significant results for the understanding of locally sedimentary deposits. The results showed an environment of carbonate, with predominance of algae limestone, associated to unconsolidated sediments with gross granularity, besides the presence of rhodoliths in all samples.The fragmentation of biotic components and the prevalence of elliptical rhodoliths with little or no branch, indicate an environment of high energy hydrodynamics. This work is a further contribution to the understanding of sedimentology active locally in reef environments, in particular the of Maracajaú reef, by virtue of their complex ecosystem composed of a diversity of wild fauna and flora that still little studied in Brazil comparing to accelerated growth of teeth extractions and usufructs of natural resources causing often irreversible impacts to the environment

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This work focuses the geological and geomorphological characterization of the inner shelf in the West Coast of the Rio Grande do Norte state, particularly the reef coral barrier offshore of Maracajaú (Maxaranguape district). If developed without the necessary concerns, tourism and entertainment activities that have been widely increased during the last five years can lead to irreversible environmental damages to the biotic and abiotic ecosystems of the region. Regarding these aspects, it is crucial the realization of a detailed study to envisage the achievement of a self-sustainable development, especially with respect to the possibilities of a rational usage of the region. This is the aim of this manuscript, which consisted of an initial stage of digital modeling of the terrain with basis on digitalization and vectorization of the Nautical map number 803 (Naval Service of Brazil, 1971). Information obtained in this phase was improved with the digital processing of small format aerial photos acquired from six flights, which were integrated to form a photomosaic of the area. The refined maps produced with the data from Nautical and aerial photo-interpretations aided to locate 9 bathymetric profiles, which provided information about the sea floor relief of the whole area. This later aided in the choosing of areas to bottom sampling that, in its turn, helped to characterize sediments present in floor of the inner shelf. Sixty-four samples collected during this work were studied by granulometrical and chemical analysis; with the later one developed in order to measure carbonate and organic matter contents. Forty-two of these samples showed carbonate content higher than 80% and organic matter in the range of 0.58% to 24.06%. With respect to grain size, these samples are in the interval between fine- to mid-grained sands. Sands with grain sizes higher than this one are also composed by carbonate carapaces such as pale yellow to red rhodolites with ellipsoidal and spheroidal shapes. During determination of the submerse features, the small format aerial photos demonstrated to be a useful methodology to aid the delineation of the sea floor topography through shallow deep waters. The bathymetry, for its turn, revealed several features at the bottom of the platform, in which the most conspicuous are undulations and morphological details of the São Roque Channel. Examination of bottom, aside from sand, yielded the identification of bivalves, ostracods, fragments of bryozoans, spikes of sponges, spines of echinoderms, operculum of gastropods and foraminifers. From the above it is concluded that the multi-methodological approach developed in this study worked efficiently, permitting the geomorphological and environmental characterization of the inner shelf of the North Maracajaú

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Estudou-se retrospectivamente a evolução clínica de dois pacientes, até sua falência cardíaca irreversível (FCI), submetidos à monitorização contínua da pressão intracraniana (PIC). O estudo detalhado desses traçados mostrou que, nos dois casos a PIC atingiu valores máximos 5 e 12 h antes de ocorrer diminuição na amplitude das ondas, observada 47 e 60 h pré-FCI. Essa diminução foi progressiva e tornou-se linear cerca de 30 h antes da FCI, em ambos os casos. O diagnóstico clínico de morte encefálica (ME) foi obtido 3 e 28 hs após a linearidade do traçado. Os autores sugerem que o diagnóstico de ME pode ser definido mais precocemente com o uso da monitorização da PIC desde que o paciente não esteja sob sedação, e salientam a necessidade de mais observações, em número maior de pacientes.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Doxorubicin is an excellent chemotherapeutic agent utilized for several types of cancer but the irreversible doxorubicin-induced cardiac damage is the major limitation for its use. Oxidative stress seems to be associated with some phase of the toxicity mechanism process. To determine if lycopene protects against doxorubicin-induced cardiotoxicity, male Wistar rats were randomly assigned either to control, lycopene, doxorubicin or doxorubicin + lycopene groups. They received corn oil (control, doxorubicin) or lycopene (5 mg/kg body weight a day) (lycopene, doxorubicin + lycopene) by gavage for a 7-week period. They also received saline (control, lycopene) or doxorubicin (4 mg/kg) (doxorubicin, doxorubin + lycopene) intraperitoneally by week 3, 4 5 and 6. Animals underwent echocardiogram and were killed for tissue analyses by week 7. Mean lycopene levels (nmol/kg) in liver were higher in the doxorubicin + lycopene group (5822.59) than in the lycopene group (2496.73), but no differences in lycopene were found in heart or Plasma of these two groups. Lycopene did not prevent left ventricular systolic dysfunction induced by doxorubicin. However, morphologic examination revealed that doxorubicin-induced myocyte damage was significantly suppressed in rats treated with lycopene. Doxorubicin treatment was followed by increase of myocardium interstitial collagen volume fraction. Our results show that: (i) doxorubicin-induced cardiotoxicity was confirmed by echocardiogram and morphological evaluations; (ii) lycopene absorption was confirmed by its levels in heart, liver and plasma; (iii) lycopene supplementation provided myocyte protection without preventing interstitial collagen accumulation increase; (iv) doxorubicin-induced cardiac dysfunction was not prevented by lycopene supplementation; and (v) lycopene depletion was not observed in plasma and tissues from animals treated with doxorubicin.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A matriz extracelular (MEC) desempenha um papel importante em lesões hepáticas crônicas e tem sido estudada em modelos de intoxicação experimental. em bovinos, no entanto, não há estudos específicos sobre a MEC hepática normal ou com lesões crônicas. Por isso, foi desenvolvido um modelo de intoxicação experimental hepático usando Senecio brasilliensis, uma planta que contém alcalóides pirrolizidínicos e causa lesão hepática dependente da dose. Cinco bezerros receberam por via oral, 0.38g/kg de folhas secas por 24 dias. Biópsias hepáticas foram obtidas a cada 15 dias durante 60 dias. Sinais clínicos de complicações digestivas surgiram da terceira semana do experimento. Um bezerro morreu aos 45 dias e os outros quatro foram avaliados até os 60 dias. As biópsias hepáticas foram processadas para microscopia óptica, imuno-histoquímica e microscopia eletrônica de transmissão. No trigésimo dia, as lesões hepáticas eram progessivas caracterizadas por vacuolização hepatocelular, necrose, apoptose, megalocitose, e fibrose centrolobular, pericelular e portal. Foram realizadas avaliações quantitativas e semi-quantitativas de componentes da MEC hepática antes e após o aparecimento das lesões. Foi realizada morfometria do colágeno total e do sistema de fibras elásticas. Colágeno total e colágenos tipos I e III aumentaram progressivamente em todos os locais do fígado. Mudanças na localização, quantidade e disposição do sistema de fibras elásticas foram também observadas. Houve um aumento significativo de células de Kupffer aos 30 dias e de células sinusoidais totais aos 45 e 60 dias. As lesões hepáticas neste experimento foram progressivas mesmo após a remoção da planta. Lesões de fibrose severa foram localizadas principalmente nos espaços porta, seguido por fibrose veno-oclusiva e pericelular. Os colágenos tipo I e tipo III foram observados no fígado normal e no fígado dos bezerros afetados, com predomínio do tipo I. Nos bezerros afetados o aumento do colágeno total e do sistema de fibras elásticas foi paralelo ao aumento no número das células sinusoidais.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Investigou-se, clinicamente o resultado da ablação uveal intravítrea em 13 olhos cegos de cães com glaucoma crônico unilateral. Os olhos acometidos foram submetidos à ablação uveal intravítrea, por meio de injeção na câmara vítrea de 0,5ml de sulfato de gentamicina (40mg/ml) associado a 0,3ml de fosfato de dexametasona (4mg/ml). As variáveis clinicas oftálmicas foram quali-quantificadas em escores, por até 48 semanas do pós-operatório; além de aspectos relacionados à dor, como variações do apetite e peso corporal. Nos sinais clínicos, de secreção ocular, blefaroespasmo, quemose, hifema e pigmentação, neovascularização, pannus e variações de apetite e peso corporal, não se notaram diferenças significativas entre os momentos. A ablação uveal intravítrea diminuiu a hiperemia conjuntival, porém acarretou aumento de opacidade corneana. A associação da ablação com antiinflamatórios tópico e sistêmico indicou não se tratar de procedimento doloroso.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)