Jacek Pietraszek

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Phenolic acids are an important group of plant secondary metabolites with various, valuable therapeutic properties. Apart from plants growing in the open air, tissue cultures can be an alternative source of the secondary metabolites. The yield of their accumulation in in vitro cultures can be increased by different methods, including culture medium(More)
Melittis melissophyllum L. is an old medicinal plant. Nowadays it is only used in the folk medicine but formerly it has been applied in the official medicine as a natural product described in French Pharmacopoeia. M. melissophyllum herbs used in our studies were collected from two localities in Poland in May and September. Methanolic plant extracts were(More)
Female Hawaiian monk seals at Laysan Island in the Northwestern Hawaiian Islands seasonally risk aggressive mating attempts by groups of adult male monk seals. These attacks, which also target immature female and male seals at a lower frequency, result in injuries that are often fatal and are termed mobbings. This study was undertaken to assess the(More)
Melittis melissophyllum L., a medicinal plant currently used in the folk medicine, was analyzed for the content of flavonoid compounds. The plants were collected in two locations in Poland in May and September. MeOH Extracts from the leaves and flowers (separately) were analyzed by HPLC-DAD. Eight compounds were identified in all the samples and(More)
  • 2010
The paper describes model of a semi-active damper based on Magneto-Rheological Fluid (MRF). This model is constructed in a neural networks (NN) system. Such a solution is used because of nonlinear character of the MRF damper elements. The result of research and calculations exposes ways to solve problems connected with this kind of modeling processes. In(More)
The paper presents results of investigation on the method of determination of significant properties in the case of virtual computational objects like FEM models. Typical approach is very time-consuming and involves the sequence of meshing and high performance computing. The method proposed in the paper is time-saving by utilization of the experimental(More)