Effect of Culture Parameters on the Biosorption of Uranium onto Chlorella pyrenoidosa

The usefulness of chlorella pyrenoidosa were investigated for the removel of U(Ⅵ) from aqueous solution. Employing monofactorial and orthogonal experiment method for evaluating the biosorption of U(Ⅵ) onto chlorella pyrenoidosa, respectively, the influence of U(Ⅵ) concentration、pH、N/P and temperature on the biosorption of U(Ⅵ) by chlorella pyrenoidosa were studied.The results showed that the pH and U(Ⅵ) concentration were significant to remove U(Ⅵ) and that the increases of pH as well as U(Ⅵ) concentration was beneficial to the U(Ⅵ) absorption. However, the U(Ⅵ) absorption was affected less by the N/P and the temperature. Confirmed through orthogonal experiment, the optimum condition composition to attenuate U(Ⅵ) was 3.4mg/L U(Ⅵ) concentration at pH 6.0 with temperature 293K,and 3/1 of N/P. It was also proved that fresh cell of 1g/L(in dry weight) was able to attenuate U(Ⅵ) in wastewater from 3.4mg/L to 0.72 mg/L after batch experiments under the optimum conditions, which indicated good prospect in its future application.

Immunopathology of human schistosomiasis mansoni: I. Immunomodulatory influences on T cell function

Cell mediated immune response was studied in patients with recent and chronic Schistosoma mansoni infection. Precultured peripheral mononuclear cells showed significantly higher responses to S. mansoni adult worm antigen (SAWA) when compared to fresh cell preparations. The addition of each patient serum to the precultured cells reactions to SAWA or recall antigens demonstrated a strong inhibitory serum action, which was also noted on allogeneic cells derived from healthy subjects. The CD4 subset was the main responding cell to SAWA being this reactivity highly suppressed by the presence of the monocyte macrophage accessory cells. We stressed the simultaneous inhibitory action of humoral and cellular factors on the specific cell response to S. mansoni.