RESUMO
Morin-aluminium fluorescence and membrane filtration were successfully applied to the indirect identification of the formation of hydroxyaluminosilicates (HAS) in acidic solutions of varying pH and of known concentrations of aluminium (Al) and silicic acid (Si(OH)(4)). It was proven to be especially useful in providing evidence of the strong competition between Si(OH)(4) and Al(OH)(3) to condense with hydroxyaluminium templates to form HAS in preference to Al(OH)(3(s)). The aggregation and stability of HAS and Al(OH)(3(s)) were dependent upon both the pH and the [Al] of the solution. The applicability of these indirect techniques was confirmed using the direct observation of HAS in solution by atomic force microscopy (AFM). AFM was also a powerful tool in providing valuable information on the morphology of colloidal HAS of various structures and stoichiometries. The results have provided further confirmation of both the mechanism of HAS formation and the form and stability of HAS in solution. This information is essential to our understanding of the biological availability and hence toxicity of Al in biota, including man.
Assuntos
Ácidos/química , Silicatos de Alumínio/análise , Silicatos de Alumínio/química , Filtração/métodos , Espectrofotometria Atômica/métodos , Alumínio/análise , Alumínio/química , Precipitação Química , Coloides/química , Concentração de Íons de Hidrogênio , Hidrólise , Microscopia de Força Atômica , Reprodutibilidade dos Testes , Soluções/química , Espectrometria de FluorescênciaRESUMO
The author uses a segment of the National Plan for Schizophrenia Research as a representation of the current academia-driven philosophical trend of "Biological Psychiatry." A criticism of the underlying assumptions of this school of thought is offered, including the doctrines of physicalism, essentialism, and logical positivism. Quotations from authoritative sources are provided to indicate that modern biology rests on entirely different assumptions and that different models and scientific methods are in order in psychiatry to get in step with the progress in contemporary science.
