|Study of volumetric oxygen transfer coefficient in a Taylor vortex flow bioreactor|
Patrícia Ap. Santiago, Cláudio A. T. Suazo, Roberto C. Giordano
An inadequate transfer of oxygen can lead to rapid changes in cell physiology, metabolism, and cell death. In this work, the KLa is evaluated in a Taylor vortex flow bioreactor and a mass transfer correlation is proposed. The experimental conditions employed were: rotational Reynolds number between 244 and 2928, airflow rates varying from 80 mL.min-1 to 550 mL.min-1 and used culture medium DMEM.
|Hyperbaric Bioreactors use with Yarrowia Lipolytica Cultures: Cellular Adaptation to Hyperbaric Conditions|
Marlene Lopes, Nelma Gomes, Manuel Mota, Isabel Belo
In this work, a pressurized bioreactor was used for Y. lipolytica batch cultivation under increased air pressure from 1 bar to 6 bar. Cell growth was strongly enhanced by the pressure rise. The increase of oxygen availability caused the induction of the antioxidant enzyme SOD. The pre-growth of Y. lipolytica under increased pressure conditions did not affect the lipase production ability of the cells.
|Adaptive control of glycerol & methanol feeding in recombinant Pichia pastoris cultures: Impact on antibody titre|
Filipe Ataíde, Ana Raquel Ferreira, João J. Clemente, António E. Cunha, Rui Oliveira
Pichia pastoris processes for heterolougous protein expression are typically run in three phases: a batch phase, an exponential feeding fed-batch phase and a long oxygen transfer limitation (OTL) phase. The final protein titre is often limited by the oxygen availability in the OTL phase. Here a direct adaptive controller is designed for the OTL phase. The controller was validated in pilot P. pastoris cultivations expressing a single chain antibody fragment (ScFv). This work shows that the propos
|Scalability of heterogeneous MW-heated processes|
Mark H.C.L. Dressen, Bastiaan H. P. van de Kruijs, Jan Meuldijk, Jef A. J. M. Vekemans, Lumbertus A. Hulshof
The combination of flow chemistry and microwave heating offers a unique opportunity to scale out heterogeneous microwave-assisted organic reactions. The feasibility of this setup is depending on the presence of a microwave effect, safety issues and energy efficiency.
|Palladium-Catalyzed Three-Component Synthesis of Phenothiazines|
Troels Dahl, Christian Wenzel Tornøe, Benny Bang-Andersen, Poul Nielsen and Morten Jørgensen
The formation of aromatic carbon-heteroatom bonds has traditionally been achieved by nucleophilic aromatic substitution or via the copper-mediated Ullman reaction. The palladium-catalyzed formation of aromatic C-N bonds extensively developed by Hartwig and Buchwald has provided a powerful alternative. While the aryl amination reaction is applicable even to aryl chlorides and activated phenols, the analogous C-O and C-S bond forming reactions have attracted less attention.
|High Throughput Microwave Synthesis of Metal Organic Framework (MOF) Libraries|
Neil L. Campbell, Jake Grace, Richard W. Dewson, Jean-Noel Rebilly, Darren Bradshaw, Ben Carter, Andrew I. Cooper and Mathew J. Rosseinsky
Metal-organic frameworks (MOFs) are an emerging class of new nano-porous materials of considerable academic and industrial interest due to their potential applications in gas storagechiral separations and catalysis. MOFs are prepared from the self-assembly of metal ions (nodes) and organic ligands (spacers), where the structural topology of the resulting crystalline frameworks is driven by the co-ordination preferences of these nodes and spacers. MOFs offer opportunities not available to more cl
|A new exposure system for the in vitro detection of GHz field effects on neuronal networks|
Philipp J. Koester, Jan Sakowski, Werner Baumann, Hans-Walter Glocka, Jan Gimsa
Different ideas exist about possible targets for biological effects of electromagnetic fields (EMF). One of the favourite systems are the membranes of nerve cells, e.g. in the central nervous system. Our aim is to clarify whether EMF exposure may induce athermal effects. In the experiments, direct electrophysiological in vitro measurements are conducted on neuronal networks exposed to EMF, i.e. possible changes in the action potential patterns produced by the networks are detected. The technique
|Microwave-Assisted Rapid Access to Bio-active Heterocycles |
Vivek Polshettiwar and Rajender S. Varma
Environmentally benign protocols have been developed for the synthesis of various pharmaceutically active heterocycles namely 1,3,4-oxadiazoles, 1,3,4-thiadiazoles, 1,3-dioxanes, pyrazoles, hydrazones and 3,4-dihydropyrimidin-2(1H)-ones, which proceed under the influence of microwave irradiation and using eco-friendly conditions. These greener protocols were catalyzed efficiently by solid supported Nafion®NR50, phosphorus pentasulfide on alumina under solvent-free conditions.
|New Accessories for High Throughput and Combinatorial Approach in a Microwave Batch Reactor|
Alexander Stadler, Thomas Karner, Matthias Treu
A unique sealable well-plate system is introduced allowing screening reactions in a 8x6 well format with operation limits of 200°C and 20 bar and a reaction volume of 0.3 mL per well. An appropriate turntable enables to proceed up to 4 of these SiC well plates in one run resulting in 192 parallel reactions at a time. Reaction control is achieved by sensing the IR temperature of the plate surface.
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