Zusammenfassung: Hintergrund und ZielMikrobiologische Alkylierungsraten sind im Hinblick auf den unter natürlichen Bedingungen stattfindenden Rückgang der Selenkonzentrationen bzw. -frachten kontaminierter Ökosysteme von Interesse.

Material und MethodenZur Analyse der leichtflüchtigen Organoselenverbindungen im Deponiegas wie auch über die mikrobiologischen Inkubationsansätze wurde die Gasphase in Tedlar^®-Beuteln gesammelt. Die Kopplung von effizienter Anreicherung (cryotrapping-cryofocusing), gaschromatografischer Trennung und einem relativ nachweisstarken elementselektiven Detektor als CT-CF-GC-ICP-MS ermöglichte eine direkte Selenspeziation in der Gasphase mit Nachweisgrenzen im Ultraspurenbereich (pg Se) sowohl im Deponiegas als auch in den Kulturansätzen.

Shearing experiment controlled with the help VIT-FIT Syringe pumps to study the cell damage in mammalian cell culture: 2008

Abstract: In the pharmaceutical industry mammalian cell lines gained more and more attention in the last decade and are nowadays the primary expression system in the production of therapeutic recombinant proteins. Despite its diverse drawbacks, the stirred tank reactor (STR) is usually the system of choice and serves as major workhorse for most applications. To overcome the limitations faced in established processes, improved bioreactors are needed to provide a more favorable in vitro environment to mimic in vivo conditions.
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Abstract: We studied the effect of submicromolar concentrations of cytochrome c (cyt c) on the phase behavior of ternary lipid membranes composed of charged dioleoylphosphatidylglycerol, egg sphingomyelin and cholesterol. The protein was found to induce micron-sized domains in membranes belonging to the single-fluid-phase region of the protein-free ternary mixture and, as a result, to expand the region of coexistence of liquid ordered (L_o) and liquid disordered (L_d) phases. Direct observations on individual vesicles revealed that protein adsorption increases the area of L_d domains.

Abstract: This work is concerned with the surface modification of fluorescent silica nanoparticles by a monoclonal antibody (M75) and the specific bioadhesion of such particles to surfaces containing the PG domain of carbonic anhydrase IX (CA IX), which is a trans-membrane protein specifically expressed on the surfaces of several tumor cell lines. The adhesion strength of antibody-bearing silica nanoparticles to antigen-bearing surfaces was investigated under laminar flow conditions in a microfluidic cell and compared to the adhesion of unmodified silica nanoparticles and nanoparticles coupled with an unspecific antibody.

Abstract: The biological properties of a protein critically depend on its conformation, which can vary as a result of changes in conditions such as pH or following the addition of various substances. Being able to reliably assess the quality of protein structures under various conditions is therefore of crucial importance. Infrared (IR) spectroscopy of the Amide I band of proteins is a powerful method for the determination of protein conformations and further allows the analysis of continuously flowing solutions of the target molecule.

Abstract: Selenium exists in different oxidation states (+6, +4, ±0, -2) in diverse environmental compartments. Different properties are related to these oxidation states, for example water solubility, which is closely correlated with the migration capability and the bioavailability.
In this study, the availability of inorganic selenium species was investigated in different laboratory experiments to get information on the mobility of these species. Hereby selenite adsorbed on goethite was incubated with a pure culture of active methylating fungus Alternaria alternata as well as with an enriched environmental mixed culture.

Abstract: Deposition kinetics of β-lactoglobulin at a solid−liquid interface was studied with optical waveguide lightmode spectroscopy (OWLS) over a range of temperatures between 61 and 83 °C. A new temperature-controlled cell for OWLS measurements allows fast, on-line monitoring of the deposit formation at elevated temperatures. Primary protein layers were deposited at 25 °C in order to precondition and stabilize the waveguide surface. Sustained deposition lasting from a few minutes (around 80 °C) to hours (below 70 °C) resulted in multilayer deposits up to several tens of nanometers thick. The measured deposition rates were strongly influenced by temperature, pH, and NaCl concentration.

Abstract: Deposition of dissolved or suspended material from liquids at solid surfaces is present in various applications occurring not only in chemical process technologies, but also in many food, biomedical, environmental and mineral processing industries. Control of deposition phenomena through appropriate design of surface properties has been subject of much interest in recent years. Read more

Abstract: Our electroporation microchip precisely controls the electric field on cells without bubble generation in microchannel by utilizing ionic conductivity of a polyelectrolyte hydrogel. pDADMAC (poly diallyldimethylammonium chloride) delivers electric potential from the electrode reservoir to the cells in microchannels Bubble generation is completely blocked without a high voltage source or a pulse generator . According to the calculation with CFD-ACE, the electric field across the salt bridges is around 1.3 kV/cm which meets the general electropermeation field strength (0.3-1 kV/cm).

Abstract: An efficient 3D-asymmetric microelectrode system for high-throughput was designed and fabricated to enhance sorting sensitivities to the dielectric properties—size, morphology, conductivity, and permittivity—of living cells. The principle of the present system is based on the use of the relative strengths of negative dielectrophoretic and drag forces, as in a conventional 3D-microelectrode system. Whereas the typical 3D-microelectrode system has a constant electric field magnitude due to the constant width of the microelectrodes and a fixed gap between face-to-face microelectrodes,

Abstract: This paper presents an integrated cell processor for the automatic handling of individual embryo cells. The integrated processor can perform various functions such as cell transport, isolation, orientation, and immobilization. These functions are indispensable and frequently used for the manipulation of single cells, but can only be carried out by a skillful operator. The purpose of this study was the integration and automation of these functions for effective cell manipulation, using a MEMS approach. The isolation of a cell was performed using polypyrrole (PPy) valves in a microchannel into which cells were transported.

Abstract: In this paper, we present a novel integrated bio cell processor to handle individual embryo cells. Its functions are composed of transporting, isolation, orientation, and immobilization of cells. These functions are essential for biomanipulation of single cells, and have been typically carried out by a proficient operator. The purpose of this study is the automation of these functions for effective cell manipulation using a MEMS based bio cell processor. This device is realized with relatively simple design and fabrication process. To transport cells, microfluidic channel is employed. The isolation of a cell is performed by actuation of polypyrrole (PPy) valves.

Abstract: There is a great demand to manipulate biological cell autonomously since biologist should spend much time to obtain skillful manipulation techniques. For this purpose, we propose a cell chip to control, carry, fix and locate the cell. In this paper, we focus on the cell rotator to rotate individual biological cell based on a micro fluidics technology.