Zpracování povrchových elektromyografických signálů

Katedra teorie obvod

The Comparative Analysis of Free Technique Cross Country and Skating on Roller Skies

The skiing is a very old human locomotion on the snow. During the last century, it has became very popular winter and Olympic sport, currently profiting from its great popularity among the public. New cross country skiing technique – skating – has been developing very dynamically since the eighties years of the 20th century. This presented study deals with a comparison of muscles activation during skating technique on skis and on roller skis. We studied three base styles of skating: V-1 on right and left side and V-2. The beginnings of important activation of the muscles on a right leg and their subsequent deactivation during one step cycle were measured with surface electromyography (SEMG). The results confirm the idea that we can consider roller skiing as a special training device of cross country skiing. This is correct from the kinetic view as well as from the connection of muscles. The biggest differences in phase shifts of muscle unit activation were found between V-1 on left side during cross country skiing and roller skiing.Skiing is a very old human activity on snow. During the last century, it has become a very popular winter and Olympic sport, currently profiting from its great popularity among the public. A new cross country skiing technique – skating – has been developing very dynamically since the 1980’s. This presented study deals with a comparison of muscles activation during the skating technique on skis and on roller skis. We studied three base styles of skating: V-1 on right and left side and V-2. The important activation of the muscles on a right leg and their subsequent deactivation during one a step cycle were measured with surface electromyography (SEMG). The results confirm the idea that we can consider roller skiing as a special training device for cross country skiing. This is correct from the kinetic view as well as from the connection of muscles. The biggest difference in phase shifts of muscle unit activation were found between V-1 on left side during cross country skiing and roller skiing

Design of sustainable ionic liquids based on l-phenylalanine and l-alanine dipeptides: Synthesis, toxicity and biodegradation studies

A series of dipeptide ionic liquids (ILs) with l-phenylalanine and l-alanine fragments in structure were synthesized and their possible degradation pathways were analyzed. Based on this analysis, potential transformation products (PTPs) were proposed and synthesized. All of these compounds (25 in total) went through microbial toxicity screening and aerobic biodegradation testing. Obtained results demonstrated that by investigating ILs and PTPs with a dipeptide fragment (in tandem with single amino acid analogues), the design of ILs with high biodegradation values in closed bottle test can be accomplished. One finding was that within the scope of the compounds studied, l-phenylalanine containing compounds were more biodegradable than l-alanine derivatives. In addition to the choice of amino acid residue, its position in the dipeptide IL structure also had a significant effect on biodegradability. PyCH2CO-Phe-Ala-OEt IL, where l-phenylalanine was in close proximity to the positively charged pyridinium sub-unit, gave higher biodegradation percentages compared to PyCH2CO-Ala-Phe-OEt IL, where alanine was closer to pyridinium than the phenylalanine residue. Analysis of PTPs data showed that the presence of an alanine residue resulted in undesirable (less green) PTPs more often compared to PTPs containing phenylalanine, especially when alanine was in close proximity to the pyridinium headgroup. Based on both toxicity and biodegradation testing results preferable and less preferable subunits can be chosen for the design of new sustainable chemicals based on amino acids. Results from this study demonstrate a potential of designing new sustainable chemicals using amino acid moieties as part of their structure

Reduced Photoinhibition under Low Irradiance Enhanced Kacip Fatimah (Labisia pumila Benth) Secondary Metabolites, Phenyl Alanine Lyase and Antioxidant Activity

A randomized complete block design experiment was designed to characterize the relationship between production of total flavonoids and phenolics, anthocyanin, photosynthesis, maximum efficiency of photosystem II (Fv/Fm), electron transfer rate (Fm/Fo), phenyl alanine lyase activity (PAL) and antioxidant (DPPH) in Labisia pumila var. alata, under four levels of irradiance (225, 500, 625 and 900 μmol/m2/s) for 16 weeks. As irradiance levels increased from 225 to 900 μmol/m2/s, the production of plant secondary metabolites (total flavonoids, phenolics and antocyanin) was found to decrease steadily. Production of total flavonoids and phenolics reached their peaks under 225 followed by 500, 625 and 900 μmol/m2/s irradiances. Significant positive correlation of production of total phenolics, flavonoids and antocyanin content with Fv/Fm, Fm/Fo and photosynthesis indicated up-regulation of carbon-based secondary metabolites (CBSM) under reduced photoinhibition on the under low light levels condition. At the lowest irradiance levels, Labisia pumila extracts also exhibited a significantly higher antioxidant activity (DPPH) than under high irradiance. The improved antioxidative activity under low light levels might be due to high availability of total flavonoids, phenolics and anthocyanin content in the plant extract. It was also found that an increase in the production of CBSM was due to high PAL activity under low light, probably signifying more availability of phenylalanine (Phe) under this condition

Six-membered ring systems: with O and/or S atoms

A large variety of publications involving O- and S-6-membered ring systems have appeared in 2017. The importance of these heterocyclic compounds is highlighted by the huge number of publications on the total synthesis of natural oxygen derivatives and of other communications dedicated to synthetic derivatives. Reviews on stereoselective organocatalytic synthesis of tetrahydropyrans (17EJO4666), of tetrahydropyrans and their application in total synthesis of natural products (17CSR1661), on the synthesis of the less thermodynamically stable 2,6-trans-tetrahydropyrans (17S4899), on enantioselective synthesis of polyfunctionalized pyran and chromene derivatives (17TA1462), and on enantioselective and racemic total synthesis of camptothecins, including the formation of their pyran-2-one ring (17SL1134), have appeared. Advances in the transition metal-catalyzed synthesis of pyran-2/4-ones (17TL263), N-heterocyclic carbene (NHC)-catalyzed achiral synthesis of pyran-2-one, coumarin and (thio)chromone derivatives (17OBC4731), on the synthesis and transformation of 2H-pyran-2-ones (17T2529) and 2-styrylchromones (17EJO3115) into other heterocyclic compounds, have been surveyed. The strategies to build up the tetrahydropyranyl core of brevisamide (17H(95)81) and the reactions of ketyl radicals, generated from carbonyl derivatives under transition-metal photoredox-catalyzed conditions, leading to isochromen- and chroman-type compounds (17CC13093) were disclosed. Developments in the synthesis of pentafluorosulfanyl(chromene and coumarin) derivatives (17TL4803), photoswitchable D9-tetrahydrocannabinol derivatives (17JA18206), and aminobenzopyranoxanthenes with nitrogen-containing rings (17JOC13626) have been studied.info:eu-repo/semantics/publishedVersio

Folia Forestalia Polonica, series A

AbstrAct The study presents the results of investigation on reaction of beech (Fagus sylvatica L.) leaves observed next year after planting seedlings in different positions in a young spruce stand located in upper mountain conditions. The methods of chemical analyses and assessments of chlorophyll fluorescence were applied with the aim to evaluate a course of leaf adaptation. In the young spruce stand located in the Karkonoše Mts, bare root beech seedlings after cultivation in full light were planted into three main positions to spruce trees (under the crown, within crown perimeter and in stand gaps). Next year after planting, the total biomass, leaf nutrient content and chlorophyll fluorescence parameters were evaluated. The beech trees planted under spruce (Picea sp.) crowns had significantly lower specific leaf mass and the mean leaf area was decreasing from shade to sun. Differences in nutrient contents were not significant between the treatments. We found significantly higher values of minimal (F 0 ) and the maximum fluorescence (F m ) as well as of the maximum quantum yield of PSII photochemistry (F v /F m ) in the leaves of beeches growing under the spruce crown. Significant differences among treatments were found also in the courses of the values of maximum fluorescence yield Y(II) and nonphotochemical quenching (NPQ). Our study indicated that bud forming processes are only partially responsible for physiological properties of beech leaves evaluated next year after planting. Photosynthetic performance is also influenced by actual growing conditions. A great part of acclimation occurs already in the first year after planting (change of the light conditions). We speculate that this phase of gradual acclimation of the assimilation apparatus can be one of the reasons of physiological weakening of the plant after planting to different light environment

Wildland Fires in the Czech Republic—Review of Data Spanning 20 Years

The following article deals with more than 20 years of historical wildland fire data from the Czech Republic, logged in the databases of the operational centers of the Fire and Rescue Service of the Czech Republic (FRS of CR). First, the definition of the term wildland fire is introduced. After that, the locations of wildland fires are discussed, from the point of view of their introduction into the information systems. Next, as the FRS of CR is organized on a regional basis, the number of wildland fires is analyzed regionally. On the basis of this analysis, some advice concerning the preparation for and prevention of wildland fires is provided—for example, focusing fire prevention campaigns in regions where the wildland fire incidence per inhabitant is high, planning aerial firefighting asset coverage with respect to the occurrence of wildland fires, or deploying the necessary fire suppression equipment according to the dominant wildland fire fuel type. Finally, questions concerning the homogeneity of groups of wildland fires which naturally emerge during the process of selection from the emergency database are discussed