Helge Hülsen

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Partially and highly purified lectins from Viscum album L. (mistletoe) cause a dose-dependent decrease of viability of human leukemia cell cultures, MOLT-4, after 72 h treatment. The LC50 of the partially purified lectin was 27.8 ng/ml, of the highly purified lectin 1.3 ng/ml. Compared to the highly purified lectin a 140-fold higher protein concentration of(More)
Current research work on the development of an automated nanohandling cell in a scanning electron microscope (SEM) is presented. An experimental setup is shown, in which two micro robots cooperate in the vacuum chamber of an SEM. A client-server control system that can integrate various microrobots and sensors has been developed and evaluated by automatic(More)
This paper describes current research activities on the development of a versatile microrobot-based nanohandling cell inside a scanning electron microscope (SEM). The precondition for using an SEM are high-precise, user-friendly microrobots which can be integrated into the SEM chamber and equipped with application-specific tools. Different aspects of this(More)
Current research activities on the development of a system for transport and manipulation of biological cells with microrobots are described. If single cells in liquid are to be placed on a grid or sorted by cell type, having a system that can automatically lift, transport and release cells can significantly speed up such a tedious task. Therefore, a system(More)
− This paper describes current research activities on the development of a control system for the automated handling of biological cells with mobile microrobots. Two main aspects are covered: A motorized inverted microscope is used to extract position coordinates of the microrobot's end-effector and the biological objects. A motion control system uses this(More)
The in vitro effectiveness of three Helixor preparations produced from mistletoes of different host trees on suspension cell cultures of the human leukemia cell line Molt 4 has been compared by means of dose-response investigations. After 72 h treatment the preparation produced from mistletoes of the appletree (Malus) shows the strongest effect on the(More)
product (bp 1 83 ~ which was further purified by preparat ive G L C on SE 30. The method described here provides an excellent tool for the synthesis of chiral-branched hydrocarbons start ing from optically active branched carboxylic acids. The diastereomers of 5,9-dimethylheptadecane could not be separated by GC; however, retention time and mass spectrum(More)