The paper presents results of mechanical testing of soft tissues (arterial walls) under biaxial stress conditions and analysis of the influence of some factors, such as specimen location, reconditioning, etc. Soft tissues are pseudoelastic materials, modelled mostly as hyperelastic, either isotropic or anisotropic ones. Therefore multiaxial (biaxial) mechanical tests are required for a credible identification of their mechanical parameters. As living tissue proporties change with time after excision and exhibit also viscoelastic behaviour, a much more specialized equipment is needed to perform biaxial tests of soft tissues. A test rig for biaxial tests is presented in the paper and a pronounced influence of stress state character on the specimen behaviour during several first cycles is analyzed. and Obsahuje seznam literatury
Jádrem Kutnarova příspěvku Historik Jaroslav Werstadt je jeho smuteční projev při Werstadtově kremaci 17. ledna 1970 v Praze - Strašnicích. Kutnar jej připravil jako nekrolog pro Československý časopis historický, ale normalizační redakce časopisu jej odmítla vytisknout. Edice vychází ze srovnání pěti verzí textu, uložených v osobním fondu Františka Kutnara v Archivu Národního muzea (karton 34, inventární číslo 822). Příspěvek přináší charakteristiku Werstadtových životních osudů a díla, se zvláštním zdůrazněním jeho přínosu v oblasti teorie a metodologie historické vědy. Je (jako všechny Kutnarovy texty) hluboce promyšlen a napsán s velkým zřetelem k obsahu i formě sdělení. Jako významný doplněk textu je otištěno Kutnarovo krátké úvodní slovo k přednášce Karla Kučery o Jaroslavu Werstadtovi v Historickém klubu 28. května 1970. and František Kutnar's paper The Historian Jaroslav Werstadt is based on his funeral oration given at Werstadt's cremation on 17th January 1970 in Prague-Strašnice. Kutnar wrote it as an obituary for the Czechoslovak Historical Journal, but the normalization-period editorial board refused to print it. This edition is based on a comparison of five versions of the text in František Kutnar's private papers at the National Museum Archive (Box 34, Inventory No. 822). This paper provides an outline of Werstadt's life and work, with special emphasis on his contribution to the field of theory and methodology in historical studies. Like all Kutnar's texts, it has been systematically thought out and written up with close attention paid to both content and form. Kutnar's brief introduction to the lecture by Karel Kučera on Jaroslav Werstadt at the History Club on 28th May 1970 also provides a substantial addition to the text. (Translated by Melvyn Clarke.)
Host responses against skin inhabiting monogeneans are commonly obserÇetHtflfthe responsible immune mechanisms in the fish skin are insufficiently described. Based on recent knowledge of fish immunity and skin response mechanisms in mammals a model for the skin immunity in fish to monogcnean infections is proposed. Important cellular components of the model are the epithelial cells, the mucous cells and leucocytes. The release of cytokines, e.g. IL-1, following mechanical or chemical injury of the epithelial cells, initiates a series of events leading to decrease of the ectoparasite population. Cytokines (e.g. IL-1, TNF, INF) are suggested to affect secretions from mucous cell and attract neutrophils and macrophages. Leukotrienes are probably involved in the inflammatory reactions. The subsequent production of humoral substances (among others complement factors and peptides) could be responsible for the antiparasitic response in the later stages of infection. Although non-specific factors dominate the response, the involvement of specific antibodies and lymphocytes cannot be excluded.
The article looks into the basic word-formation relations - semantic motivation and formal foundation - and the tension between them. It presents three cases of word-formative analogy, i.e. imitating of a productive word-formative model by the copying of a morfematic structure of derivatives, regardless of the completeness or incompleteness of the derivative line. The article reflects experience gained during the work on Dictionary of affixes used in Czech.
A simplified mathematical model for free vibrations of nonuniform viscoelastic flexural beams is presented. The mass intensity, the material damping intensity and the flexural stiffness of the beam are assumed varying as power functions along the beam. An analytical solution for the fourth order differential equations of beam vibration under appropriate boundary conditions is obtained by factorization. Mode shapes and damped natural frequencies of the beam are obtained for wide range of beam characteristics. The model results agree with those found in literature for uniform beams. and Obsahuje seznam literatury