Tuková tkáň je endokrinní orgán produkující početné cytokiny. Změna v jejich regulacích může být příčinou patologických pochodů u obézních jedinců. Význam tukové tkáně ve vztahu k diabetu a ateroskleróze je intenzivně studován., Adipose tissue is an endocrine organ that produces numerous cytokines. Their dysregulations cause morbidity in obese individuals. The importance of this tissue in relation to diabetes and atherosclerosis is the subject of intense research., and Ilja Trebichavský, Petr Šíma.
Tumor necrosis factor a (TNFa) was found to be significantly increased in skeletal muscles and retroperitoneal fat of obese insulin-resistant Koletsky rats as compared to control Wistar rats. This increase was accompanied by a depression of insulin receptor protein tyrosine kinase (PTK) activity. Neither the insulin-binding capacity nor insulin receptor affinity were related to this TNFa increase in these tissues. In the liver, no significant changes of TNFa content and only a lowering of insulin-binding capacity were found. It is concluded that an increased TNFa content in muscles and fat (but not in the liver) contributes to insulin resistance by lowering insulin receptor protein tyrosine kinase activity, while other insulin receptor characteristics (insulin-binding capacity and affinity of insulin receptors to the hormone) do not seem to be influenced by this factor., A. Hřebíček, M. Rypka, Z. Chmela, J. Veselý, M. Kantorová, V. Golda., and Obsahuje bibliografii
Průběh koryta a niva Lužnice zaznamenaly po povodních v roce 2002 a 2006 značné změny. Vznikla nová mrtvá ramena a tůně. Tyto změny ale neměly výrazný destruktivní vliv na ekosystém nivy. Autor popisuje různé typy tůní a procesy jejich vzniku a zániku i společenstva mokřadních rostlin v nivě Lužnice. and The watercourse and floodplain of the Lužnice river were greatly changed after flooding in 2002 and 2006. New river branches and pools were created, but these changes have not influenced negatively floodplain ecosystems. The author describes different types of pools and their development, as well as communities of wetland plants in the Lužnice river floodplain.
V práci jsou ukázány možnosti distanční a napěťové tunelové spektroskopie na vzduchu a v elektrolytu. Jako příklad je uvedena distanční tunelová spektroskopie zlata v kyselině sírové a napěťová tunelová spektroskopie zlata na vzduchu a anatasu ve fosfátovém pufru., Jan Weber, Hana Pelouchová, Pavel Janda., and Obsahuje seznam literatury
Field observations showed that in many gravel-bed rivers, rice stems and gravel interact with each other and affect the flow structure. This calls to conduct research in more details in laboratory to better understand impacts of interaction between rice stems and gravel bed rivers on the flow structure. The outcome of such investigations can improve the estimation of drag coefficient in hydrodynamic models. Experiments were carried out in a flume with gravel bed and the vegetated vertical flume walls to investigate turbulence characteristics under favorable pressure gradient flows. Results showed that the stress fraction involves both the sweep and ejection dominance near the vegetated flume walls, showing no negative Reynolds shear stress near water surface. The values of exuberance ratio play a significant role on the magnitude of the Reynolds shear stress which varies with the distance from the vegetation. Quadrant analysis reveals that a major part of the momentum flux is transported during a short period of strong turbulence activity near the bed at the central axis. Augmentation of the hole size makes difference between contributions of sweep and ejection with those of the outward and inward interactions near the bed, however, the hole size doesn’t play any role near the water surface.