Pacient s trombózou mozkových splavů a současným intracerebrálním hematomem parieto-okcipitálně byl neúspěšně léčen plnými dávkami intravenózní antikoagulace. Vzhledem k postupné progresi klinického stavu vedoucí ke ztrátě vědomí byla indikována endovaskulární intervence. Pro časté ucpávání aspiračního systému Penumbra byl originálně použit guiding katétr Neuron (současně se Separator 3D) zavedený přímo do trombu namísto Reperfusion katétru se současnou aspirací trombu. Tento postup byl bezpečný a úspěšný a může být použit u pacientů s rozsáhlým trombotickým postižením. Klíčová slova: trombóza mozkových splavů – trombektomie – endovaskulární – aspirační systém Autoři deklarují, že v souvislosti s předmětem studie nemají žádné komerční zájmy. Redakční rada potvrzuje, že rukopis práce splnil ICMJE kritéria pro publikace zasílané do biomedicínských časopisů., A patient with ongoing cerebral venous sinus thrombosis and a parieto-occipital intracerebral haematoma was unsuccessfully treated with full-dose intravenous anticoagulation. A common endovascular aspiration technique was indicated because of the progressive severe deterioration, the level of consciousness had failed. As a novel approach, we used the 6F Neuron guiding catheter (together with The Separator 3D) inserted directly into the thrombus instead of the Reperfusion Catheter, for mechanical disruption of the thrombus mass together with continual aspiration. This procedure was safe and successful and can be used in cases of frequent aspiration catheter occlusions by a large amount of thrombus fragments., and J. Vanicek, M. Bulik
Let $X$ be a Banach space. We give characterizations of when ${\cal F}(Y,X)$ is a $u$-ideal in ${\cal W}(Y,X)$ for every Banach space $Y$ in terms of nets of finite rank operators approximating weakly compact operators. Similar characterizations are given for the cases when ${\cal F}(X,Y)$ is a $u$-ideal in ${\cal W}(X,Y)$ for every Banach space $Y$, when ${\cal F}(Y,X)$ is a $u$-ideal in ${\cal W}(Y,X^{**})$ for every Banach space $Y$, and when ${\cal F}(Y,X)$ is a $u$-ideal in ${\cal K}(Y,X^{**})$ for every Banach space $Y$.
We determined if mature ladybirds use colour to initially find suitable host plants. We also determined whether ladybird beetles are capable of associating characteristics such as colour with the presence of prey. Here, we show that the multicoloured Asian ladybird beetle, Harmonia axyridis, has a differential response to yellow compared to green colours. Naive ladybirds, of both sexes, make significantly more visits and spend more time on yellow vs. green coloured pillars. After pairing yellow and green colours with the presence or absence of aphid prey, ladybirds alter their foraging behaviour. Beetles conditioned to having food on both pillar colours exhibited the same responses as naive beetles, while beetles conditioned to only yellow or green pillars did not exhibit a preference for visiting or spending time on different colours. However, there was a trend towards females spending more time on pillar colours on which they received reinforcement, and males spending more time foraging on colours opposite to that which they were reinforced. Thus, H. axyridis is capable of responding to cues such as colour, and its foraging behaviour can be altered as a result of prior experience.
Odpřahující protein 2 (UCP2, uncoupling protein 2) objevený v roce 1997 je homologem rozpřahujícího proteinu 1 (UCP1), který byl objeven v mitochondriích hnědé tukové tkáně novorozených savců a dospělých hibernantů jako součást mechanismu netřesové termogeneze. Zatímco UCP1 byl prokázán pouze v hnědé tukové tkáni, UCP2 je exprimován v kosterním svalu, bílé tukové tkáni, plicích a v dalších buněčných populacích. Odpřahující proteiny fungují jako iontové kanály. Jejich otevření snižuje mitochondriální membránový potenciál, tím se snižuje účinnost energetické přeměny – snižuje se tvorba ATP a zvyšuje se uvolnění energie ve formě tepla. UCP proteiny tím, že odpřahují procesy oxidace od tvorby ATP, zvyšují oxidaci substrátů, snižují podíl redukovaných komponent respiračního řetězce a tím redukují produkci reaktivních kyslíkových radikálů mitochondriemi. V tomto článku jsou popsány možné funkce UCP2., Uncoupling protein 2 (UCP2), discovered in 1997, is the fi rst homologue of uncoupling protein 1 (UCP1) that was discovered in mitochondria of brown adipose tissue of newborn mammals and adult hibernators as the part of mechanism in non-shivering thermogenesis. While UCP1 was presented only in brown adipose tissue, UCP2 is expressed in skeletal muscle, white adipose tissue, lungs and in other cell populations. Uncoupling proteins work as ion channels. Opening of these channels decrease the mitochondrial membrane potential thereby the effi ciency of energy conversion is decreased – it is decreased production of ATP and is increased dissipation of energy in the form of heat. Uncoupling proteins uncouple the process of oxidation from the ATP formation, increase the substrate oxidation and decrease the part of reduced components of respiratory chain thereby reducing the production of reactive oxygen species in mitochondria. In this review possible functions of UCP2 are also described., Bolehovská R., Červinková Z., Pospíšilová M., Lotková H., Plíšková L., Palička V., and Lit.: 24
Since the early 20th century underdetermination has been one of the most contentious problems in the philosophy of science. In this article I relate the underdetermination problem to models in biology and defend two main lines of argument: First, the use of models in this discipline lends strong support to the underdetermination thesis. Second, models and theories in biology are not determined strictly by the logic of representation of the studied phenomena, but also by other constraints such as research traditions, backgrounds of the scientists, aims of the research and available technology. Convincing evidence for the existence of underdetermination in biology, where models abound, comes both from the fact that for a natural phenomenon we can create a number of candidate models but also from the fact that we do not have a universal rule that would adjudicate among them. This all makes a strong case for the general validity of the underdetermination thesis., Nedourčenost je jedním ze zásadních problémů filosofie vědy od počátku 20. století. Ve svém příspěvku vztahuju tezi o nedourčenosti k biologickým modelům a obhajuju následující dva argumenty: Za prvé, použití modelů v této disciplíně dodává silnou váhu tezi o nedourčenosti. Za druhé, modely a teorie v biologii nejsou determinovány striktně logikou reprezentace studovaného jevu, ale také dalšími faktory, jako jsou výzkumné tradice, background vědců, cíle výzkumu a dostupné technologie. Přesvědčivý důkaz o existenci nedourčenosti v biologii, která modelů v hojné míře využívá, pramení nejenom z faktu, že pro každý přírodní jev můžeme vytvořit velký počet alternativních modelů, ale také z faktu, že nedisponujeme univerzálním pravidlem pro výběr mezi nimi. To vše mluví ve prospěch platnosti teze o nedourčenosti., Petr Jedlička., and Obsahuje bibliografii
This study aims to articulate and compare the structure, presuppositions and implications of two paradigmatic sceptical arguments, i.e. arguments from underdetermination of scientific theories by observational data (UA) and Cartesian-style arguments (CA) invoking sceptical scenarios of severe cognitive dislocation. Although salient analogies between them may prompt one to think that a unified diagnosis of what is amiss with them is called for, it will be argued that this may be a false hope, if those analogies do not underwrite a complete homology. That said, possible parallels of one promising anti-sceptical exposure of CA are pointed out for the case of UA, which conspire together to render the problem of underdetermination less threatening than it could at first appear., Tato studie si klade za cíl artikulovat a porovnávat strukturu, předpoklady a implikace dvou paradigmatických skeptických argumentů, tj. Argumentů z podceňování vědeckých teorií pozorovacími daty ( UA ) a argumenty kartézského stylu ( CA ), které vyvolávají skeptické scénáře těžké kognitivní dislokace. Ačkoli výrazné analogie mezi nimi mohou vést k tomu, aby si někdo myslel, že je požadována jednotná diagnóza toho, co je s nimi v rozporu, bude to argumentovat, že to může být falešná naděje, pokud tyto analogie nepodléhají úplné homologii. To znamená, že případné paralely jedné slibné antiseptické expozice CA jsou poukazovány na případ UA, které spolu splynou k tomu, že problém nedostatečného určení je méně ohrožující, než by se mohlo na první pohled zdát., and Ladislav Koreň
Chlorophyll fluorescence parameter Fv/Fm, an indicator of the maximum efficiency of PS2, is routinely measured in the field with plant leaves darkened by leaf clips. I found that on a sunny day of subtropical summer, the Fv/Fm ratio was often underestimated because of a large F0 value resulted from a high leaf temperature caused by clipping the leaf under high irradiance, especially for long (e.g. 20 min) duration. This phenomenon may overestimate the down-regulation of PS2 efficiency under high irradiance. When leaf temperature was lower than 40 °C, the F0 level of rice leaves under clipping remained practically unchanged. However, F0 increased drastically with leaf temperature rising over 40 °C. In most measurements, no significant difference in Fm was found between rice leaves dark-adapted by leaf clips for 10 min and for 20 min. Therefore, shading leaf clips to prevent a drastic increase of leaf temperature, using F0 measured immediately after the leaf being darkened to calculate Fv/Fm, as well as shortening the duration of leaf clipping are useful means to avoid an underestimate of Fv/Fm.
Leaves under stressful conditions usually show downregulated maximum quantum efficiency of photosystem II [inferred from variable to maximum chlorophyll (Chl) a fluorescence (Fv/Fm), usually lower than 0.8], indicating photoinhibition. The usual method to evaluate the degree of photoinhibition in winter red leaves is generally by measuring the Fv/Fm on the red adaxial surface. Two phenotypes of overwintering Buxus microphylla ‘Wintergreen’ red leaves, with different measuring site and leaf thickness, were investigated in order to elucidate how red pigments in the outer leaf layer affected the Chl a fluorescence (Fv/Fm) and photochemical reflectance index. Our results showed that the Fv/Fm measured on leaves with the same red surface, but different leaf thickness, exhibited a slightly lower value in half leaf (separated upper and lower layers of leaves by removing the leaf edge similarly as affected by winter freezing and thawing) than that in the intact leaf (without removing the leaf edge), and the Fv/Fm measured on the red surface was significantly lower than that on the inner or backlighted green surface of the same thickness. Our results suggest that the usual measurement of Fv/Fm on red adaxial surface overestimates the actual degree of photoinhibition compared with that of the whole leaf in the winter., J. G. Peng, X. R. Jiang, J. Xu, L. Guo, R. F. Gao, Y. Liu., and Obsahuje použitou literaturu