RESUMO
Flow cytometry, a method well established in medicine and biotechnology, can also make an important contribution to (applied) limnological as well as ecotoxicological studies on phytoplankton. Flow cytometry can, for instance, contribute to the ataxonomic structural and functional assessment of phytoplankton. This approach may serve as a supplement to the well-established taxonomic evaluation by means of various microscope techniques. We present some examples for such ataxonomic phytoplankton evaluation. These examples include phytoplankton of eutrophicated and acidified water bodies as well as slowly flowing rivers. Phytoplankters may be differentiated by their pigment contents into carotinoid-rich ones (such as Chrysophyceae, Bacillariophyceae, and Dinophyceae) and carotinoid-poor ones (such as Euglenophyceae and Chlorophyceae). As a useful biomass parameter of phytoplankton algae we tested successfully protein staining by fluorescein isothiocyanate. We discuss the advantage of this approach as compared with results obtained by Coulter counter or by biomass calculations from microscope analyses. Up to now, evaluation of the biological quality of pelagic water bodies is still laborious and time consuming because of the microscopical examination of planktic communities usually practiced. As a possible improvement we present a structural ataxonomic approach for assessing the integrity of individual phytoplankters (on the basis of physiological parameters) as well as of the phytoplankton communities that is based on annual means of biomass spectra. Flow cytometry can provide considerable relief.
Assuntos
Eucariotos/metabolismo , Fitoplâncton/metabolismo , Biomassa , Sobrevivência Celular , Eucariotos/citologia , Citometria de Fluxo , Fluoresceína-5-Isotiocianato/química , Corantes Fluorescentes/química , Água Doce , Hidrólise , Fitoplâncton/citologia , Fitoplâncton/fisiologia , Proteínas/química , Proteínas/metabolismo , Especificidade da Espécie , Coloração e RotulagemRESUMO
The test of the shearstrength of two composite-inlay-materials and two posterior composites exhibited a statistically significant less bond-strength of repaired specimen compaired with unrepaired control-groups, whereas each material showed different results. The indirect-inlay-system proved to have the lowest bondstrength after repairing. The combination of the two posterior composites as well as the two inlay-systems with each other showed that none of these materials was convincing as a repairing material.
