The solid-state NMR measurements play an indispensable role in studies of interactions between biological membranes and peptaibols, which are amphipathic oligopeptides with a high abundance of α-aminobutyric acid (Aib). The solid-state NMR investigations are important in establishing the molecular models of the pore forming and antimicrobial properties of peptaibols, but rely on certain simplifications. Some of the underlying assumptions concern the parameters describing the 15N NMR chemical shielding tensor (CST) of the amide nitrogens in Aib and in conventional amino acids. Here the density functional theory (DFT) based calculations were applied to the known crystal structure of one of peptaibols, Ampullosporin A, in order to explicitly describe the variation of the 15N NMR parameters within its backbone. Based on the DFT computational data it was possible to verify the validity of the assumptions previously made about the differences between Aib and other amino acids in the isotropic part of the CST. Also the trends in the magnitudes and orientations of the anisotropic components of the CST, as revealed by the DFT calculations of the full periodic structure of Ampullosporin A, were thoroughly analyzed, and may be employed in future studies of peptaibols., J. Czernek, J. Brus., and Obsahuje bibliografii
For a finite group $G$ denote by $N(G)$ the set of conjugacy class sizes of $G$. In 1980s, J. G. Thompson posed the following conjecture: If $L$ is a finite nonabelian simple group, $G$ is a finite group with trivial center and $N(G) = N(L)$, then $G\cong L$. We prove this conjecture for an infinite class of simple groups. Let $p$ be an odd prime. We show that every finite group $G$ with the property $Z(G)=1$ and $N(G) = N(A_i)$ is necessarily isomorphic to $A_i$, where $i\in\{2p,2p+1\}$., Azam Babai, Ali Mahmoudifar., and Obsahuje bibliografii
Patch clamp recordings carried out in the inside-out configuration revealed activity of three kinds of channels: nonselective cation channels, small-conductance K+ channels, and large-conductance anion channels. The nonselective cation channels did not distinguish between Na+ and K+. The unitary conductance of these channels reached 28 pS in a symmetrical concentration of 200 mM NaCl. A lower value of this parameter was recorded for the small-conductance K+ channels and in a 50-fold gradient of K+ (200 mM/4 mM) it reached 8 pS. The high selectivity of these channels to potassium was confirmed by the reversal potential (-97 mV), whose value was close to the equilibrium potential for potassium (-100 mV). One of the features of the large - conductance anion channels was high conductance amounting to 493 pS in a symmetrical concentration of 200 mM NaCl. The channels exhibited three subconductance levels. Moreover, an increase in the open probability of the channels at voltages close to zero was observed. The anion selectivity of the channels was low, because the channels were permeable to both Cl - and gluconate - a large anion. Research on the calcium dependence revealed t hat internal calcium activates nonselective cation channels and small-conductance K+ channels, but not large - conductance anion channels., M. Koselski, A. Olszewska, A. Hordyjewska, T. Małecka-Massalska, K. Trebacz., and Obsahuje bibliografii
The purpose of this study was to compare markers of glycolytic metabolism in response to the Wingate test and the incremental test in road and mountain bike cyclists, who not different performance level and aerobic capacity. All cyclists executed the Wingate test and incremental test on a cycle ergometer. Maximal power and average power were determined during the Wingate test. During the incremental test the load was increased by 50 W every 3 min, until volitional exhaustion and maximal aerobic power (APmax), maximal oxygen uptake (VO2max), and time of VO2max plateau (Tplateau) were determined. Post-exercise measures of oxygen uptake (VO2post), carbon dioxide excretion, (VCO2post), and the ratio between VCO2/VO2 (RERpost) were collected for 3 min immediately after incremental test completion. Arterialized capillary blood was drawn to measure lactate (La-) and hydrogen (H+) ion concentrations in 3 min after each test. The data demonstrated significant differences between mountain bike and road cyclists for Tplateau, VO2post, VCO2post, La- which was higher-, and RERpost which was lower-, in mountain bike cyclists compare with road cyclists. No differences were observed between mountain bike and road cyclists for APmax, VO2max, H+ and parameters measured in the Wingate test. Increased time of VO2max plateau concomitant to larger post-exercise La- and VO2 values suggests greater anaerobic contribution during incremental testing efforts by mountain bike cyclists compared with road cyclists., P. Hebisz, R. Hebisz, J. Borkowski, M. Zatoń., and Obsahuje bibliografii
The article deals with the printer and Briefmaler (letter painter) Michael Peterle (1537-1588), who is also considered to be a woodcutter by Czech book scientists. It focuses on his pictorial broadsides and illustrated books and analyses the morphological features of the extant woodcuts. It has reached the conclusion that Peterle’s woodcutting activities cannot be proved. Apart from the art-historical perspective, it brings a number of new facts associated with Peterle’s printing activities: for instance, it documents the financial background of Prague printers in the 1570s and 1580s., Jana Tvrzníková., Obsahuje anglický abstrakt a shrnutí., and Obsahuje bibliografii
Recenzent podrobně komentuje práci dvojice chorvatských autorů (otce a syna), která pětatřicet let po smrti Josipa Broze Tita (1892-1980) jako první jeho životopis plně obstojí před všemi vědeckými nároky. Biografie podle něj imponuje nejen svým rozsahem, ale i komplexností, vyvážeností, faktografickou přesností, přesvědčivostí úsudku a v neposlední řadě čtenářsky velmi přitažlivým podáním. Recenzent vyzvedává širokou znalost a příkladné využívání pramenů, třebaže autoři neprováděli archivní výzkum, důkladnou pozornost věnovanou všem důležitým epizodám Titovy politické kariéry, citlivé vykreslení jeho privátního života a schopnost najít nesamozřejmé hranice mezi osudy a činy dlouholetého jugoslávského vůdce a poválečnými dějinami Jugoslávie, aby zůstal zachován biografický žánr. Respekt si podle jeho mínění většinou zaslouží i názorová nekonformita autorské dvojice, která nejednou směřuje proti většinovým, nacionálně zatíženým výkladům historie v současném Chorvatsku, třebaže jim v dílčích problémech podléhají. Přestože autoři řadu Titových činů a rozhodnutí hodnotí značně kriticky (například represe vůči oponentům po ustavení socialistické Jugoslávie, a zvláště konfliktu se Stalinem), představují jeho osobnost a historickou úlohu v zásadně pozitivním světle. Přisuzují mu rysy státnické velikosti, jako například mimořádnou politickou intuici, odvahu, schopnost sjednocovat etnicky různorodou společnost a vytvořit z ní funkční státní celek. Za vrcholné momenty Titovy dráhy autoři pokládají partyzánskou válku proti německo-italské okupaci a nezávislý politický kurz Jugoslávie navzdory nátlaku Stalina a východního bloku., The author looks in detail at this work by two Croatian authors, father and son, which, published 35 years after his death, is the first biography of Josip Broz Tito (1892-1980) to fully meet all scholarly standards. The biography, according to the reviewer, impresses the reader not only by its considerable lenght, but also by its comprehensiveness, balance, factual precision, convincing judgements, and, last but not least, readability. The reviewer praises the authors´ great knowledge of the topic and their exemplary handling of the sources. Although they did not work in archives, they have paid careful attention to all the important episodes of Tito´s political career, sensitively portraying his private life, and identifying the subtle boundaries between, on the one hand, the life and deeds of the man who held power in Yugoslavia for so many years and, on the other, the post-war history of Yugoslavia, while keeping within the bounds of the biography genre. The authors merit respect, according to the reviewer, for their mostly nonconformist opinions, which are frequently aimed against nationalistically burdened interpretations of the majority in Croatia today, though on some questions they too succumb to them. Although the authors are considerably critical of many of Tito´s actions and decisions (for example, his repression of opponents after the establishment of socialist Yugoslavia and particularly the conflict with Stalin), they present the man and his historiccal role in an essentially positive light. They attribute to him features of great statesmanship, for example, his extraordinary political intuition, mettle, and ability to unite an ethnically diverse society and make it into a functioning state. The high points of Tito´s career, according to the authors, were the partisan war against the German-Italian occupation and the independent political course for Yugoslavia in the face of pressure from Stalin and the Eastern bloc., [autor recenze] Jan Pelikán., and Obsahuje bibliografické odkazy