Low power laser radiation at 685 nm stimulates stem-cell proliferation rate in Dugesia tigrina during regeneration

Today's scientific interest in tissue engineering for organ transplantations and regeneration from stem cells, allied with recent observations on biostimulation of tissues and cells by laser radiation, stands as a strong motivation for the present work, in which we examine the effects of the low power laser radiation onto planarians under regenerative process. To investigate those effects, a number of 60 amputated worms were divided in three study groups: a control group and two other groups submitted to daily 1 and 3 min long laser treatment sections at similar to 910 W/m(2) power density. A 685 nm diode laser with 35 mW optical power was used. Samples were sent to histological analysis at the 4th, the 7th and the 15th (lays after amputation. A remarkable increase in stem cells counts for the fourth day of regeneration was observed when the regenerating worms was stimulated by the laser radiation. Our findings encourage further research works on the influence of optical radiation onto stem cells and tissue regeneration. (c) 2005 Elsevier B.V. All rights reserved.

Biodegradação da vinhaça resíduo da produção de etanol

The State of São Paulo is responsible for the largest sugar cane production in Brazil, as well as the largest production of ethanol made of this raw material – which is widely used as fuel for automobiles. This utilization began in the 1970’s, with the institution by the Brazilian government of the National Alcohol Program (PRO-ÁLCOOL), as a consequence of the petroleum crisis, rising again five years ago, with the development of flex fuel cars. The obtaining process of ethanol originates residues; amongst them, vinasse is the one that’s generated in the largest amount (an average of 10 to 13 litres/litre of ethanol produced). The disposal of this residue in waters was only forbidden in 1978, but before that, researchers had already been investigating its utilization as raw material. This paper had the objective of accompany the biodegradation of vinasse by evaluating the oxygen comsumption during it until the ultimate Biochemical Oxygen Demand (uBOD), performed in twenty days; another objective was to analyse the biomass production of Saccharomyces cerevisae in this residue. Physical and chemical analyses of the residue were also performed, as well as acute toxicity essays using Daphnia similis and Dugesia tigrina, before and after its biodegradation. The physical and chemical analyses pointed elevated acidness (pH = 3,98), conductivity (8,30 mS/cm) and COD (25.693,43 mg O2/L) and mean quantity of suspended solids (5.246 mg/L). The toxicity essays indicated absence of toxic potential in vinasse after biodegradation for both species. The uBOD degradated until 88,22% of the COD, demonstrating the possibility of biodegradation of most of the residue’s organic load in a relatively short period of time. S. cerevisae caused a 37,03% COD diminution in vinasse, diminished its conductivity and promoted a slight elevation of the pH; it obtained low biomass...(Complete abstract click electronic access below)

Análise do uso das águas de uma empresa do ramo petroquímico via análise de sobrevivência

Pós-graduação em Biometria - IBB

Avaliação da qualidade da água dos rios Jaguarí e Atibaia por meio do índice de qualidade da água - IQA e ensaios toxicológicos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)