HOMOGENEOUS GAS-SOLID SUSPENSIONS FOR EFFICIENT DOWNFLOW REACTORS

In order to increase heat and mass transfer and to accelerate high temperature gas-solids reactions of fine powders, downflow tube-reactors have attracted growing attention. Short reaction times of fractions of a second require short term constant feeding of gas and solids followed by the continuous and rapid formation of homogeneous suspensions with low fluctuations in time to meet required mole ratios. The objective of the present study is the preparation of short-term constant, homogeneous gas-solid suspensions under gravitational flow conditions in downflow reactors. The dynamics of dispersing a very compact dense solids jet lo achieve a homogeneous gas-solid suspension was investigated in a semi-industrial test unit with a maximum solids throughput of 5 t/h and different tube geometries.     

Genetically modified Lactococcus lactis: novel tools for drug delivery

The dairy bacterium Lactococcus lactis can be genetically engineered to secrete bioactive cytokines. This enabled the development of an entirely novel drug delivery system: topical and active delivery of therapeutic proteins by genetically modified micro-organisms. In mice, intestinal inflammation can be successfully treated with interleukin-10- (IL-10) or trefoil factor-secreting L. lactis . In human application, biological containment is guaranteed by exchange of the gene encoding thymidylate synthase for IL-10. The recombinant strain is now absolutely dependent on exogenous thymidine. Thymidine starvation will irreversibly lead to 'thymidine-less death' induction. This accomplishment has opened applications in human medicine.