ice accelerator
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The kinetics of the ozonation reaction of 1,1-diphenylethylene (DPE) on the surface of ice grains (also called "artificial snow"), produced by shock-freezing of DPE aqueous solutions or DPE vapor-deposition on pure ice grains, was studied in the temperature range of 268 to 188 K. A remarkable and unexpected increase in the apparent ozonation rates with decreasing temperature was evaluated using the Langmuir-Hinshelwood and Eley-Rideal kinetic models, and by estimating the apparent specific surface area of the ice grains. We suggest that an increase of the number of surface reactive sites, and possibly higher ozone uptake coefficients are responsible for the apparent rate acceleration of DPE ozonation at the air-ice interface at lower temperatures. The increasing number of reactive sites is probably related to the fact that organic molecules are displaced more to the top of a disordered interface (or quasi-liquid) layer on the ice surface, which makes them more accessible to the gas-phase reactants. The effect of NaCl as a cocontaminant on ozonation rates was also investigated. The environmental implications of this phenomenon for natural ice/snow are discussed. DPE was selected as an example of environmentally relevant species which can react with ozone. For typical atmospheric ozone concentrations in polar areas (20 ppbv), we estimated that its half-life on the ice surface would decrease from ∼5 days at 258 K to ∼13 h at 188 K at submonolayer DPE loadings.
The author of the article found out the influence of biological factors on motor Performance of 13 – 14 years old hockey players. They were chosen to the class with specialization for ice – hockey on elementary school in Nitra and Skalica. We found the differences in the group with same chronological age in the tests of general motor performance caused by individual acceleration or retardation which are defined by biological age. The main differences in the tests of young hockey players were found during the age of puberty.
Článek shrnuje účinky vlivu kontinuální inhalace koncentrovaného kyslíku na opakované krátkodobé zátěže v ledním hokeji v pauze mezi těmito zátěžemi. Pro ověření byla použita metoda „dvojitě slepého pokusu“. Probandi (n = 10) absolvovali v rozmezí čtyř dnů dvě testové baterie, z nichž každá zahrnovala dva specifické testy na ledové ploše v maximální intenzitě bruslení, zakončené střelbou na bránu v celkové době trvání přibližně 50 sec. Před každým zatížením a v pauze mezi nimi sledované osoby kontinuálně inhalovaly prostřednictvím masky v náhodném pořadí vzduch se zvýšenou koncentrací kyslíku nebo placebo (běžný vzduch). Zdrojem koncentrovaného kyslíku byl přístroj Everflo. Placebo bylo inhalováno z totožné masky, ale přístroj byl vypnutý. Výzkum prokázal signifikantní vliv inhalace zvýšené koncentrace kyslíku na zlepšení výkonnosti v obou testech (lepší časy a nižší hodnoty srdeční frekvence) při i po zátěži ve srovnání s inhalací placeba. Rozdíly v pozátěžové koncentraci laktátu nebyly statisticky signifikantní. Z výsledků lze usuzovat na pozitivní efekt kontinuální inhalace zvýšené koncentrace kyslíku mezi krátkodobými zátěžemi v daném modelovém zatížení.
The article summarizes the results of influence on the effect of continuous inhalation of concentrated oxygen on repeated short-term loads in ice hockey, carried out during breaks between such loads. A double-blind experiment was performed. The probands (n = 10) were tested twice over a period of four days; each testing session involved two specific tests at the ice hockey stadium, carried out during a maximal load lasting about 50 second, ending with a shot on the goal. Before each test and during the break between the tests, the subjects randomly inhaled either concentrated oxygen or placebo through a mask. The concentrated oxygen was supplied by an Everflo device. Placebo was inhaled from an identical mask with the device switched off. The investigation showed a significant effect of concentrated oxygen inhalation on acceleration in both the tests as well as on lower heart rate values during and after the load, compared to the inhalation of placebo. The change in post-load lactate concentration was not statistically significant. The results suggest the positive effect of continuous inhalation of concentrated oxygen in-between short-term loads in the described model load.
- Klíčová slova
- koncentrovaný kyslík, krátkodobé maximální zatížení, specifický test,
- MeSH
- aplikace inhalační * MeSH
- čas MeSH
- hokej * MeSH
- hyperoxie MeSH
- kyslík * MeSH
- lidé MeSH
- placebo * MeSH
- regenerace MeSH
- srdeční frekvence MeSH
- statistika jako téma MeSH
- svaly fyziologie MeSH
- zátěžový test * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
Ice-hockey requires high acceleration and speed sprint abilities, but it is unclear what the distance characteristic is for measuring these capabilities. Therefore, this systematic meta-analysis aims to summarize the sprint reference values for different sprint distances and suggest the appropriate use of ice-hockey straight sprint testing protocols. A total of 60 studies with a pooled sample of 2254 males and 398 females aged 11-37 years were included. However, the pooled data for women was not large enough to permit statistical analysis. The sprint distance used for measuring the reported acceleration and speed was between 4-48 m. Increased test distance was positively associated with increased speed (r = 0.70) and negatively with average acceleration (r = -0.87). Forward skating sprint speed increases with the measured distance up to 26 m and do not differ much from longer distance tests, while acceleration decreases with a drop below 3 m/s at distances 15 m and longer. The highest acceleration (5.89 m/s2 peak, 3.31 m/s2 average) was achieved in the shortest distances up to 7 m which significantly differs from 8-14 m tests. The highest speed (8.1 m/s peak, 6.76 m/s average) has been recorded between 26-39 m; therefore, distances over 39 m are not necessary to achieve maximum speed. Considering match demands and most reported test distances, 6.1 m is the recommended distance for peak acceleration and 30 m for peak speed. The sprint time, acceleration, and speed of each individual and the number of skating strides should be reported in future studies.
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Ice hockey requires two levels of specific agility, involving different abilities, where the level of agility and their constraints might vary by the performance level. Therefore, this study aimed to compare the relationship level between on-ice and off-ice change of directional speed (COD) of youth hockey players at two performance levels. The study was conducted during the hockey season, including U16 elite players (n = 40) and U16 sub-elite players (n = 23). Both groups performed specific on-ice fitness tests (4-m acceleration, 30-m sprint, and 6 x 54-m tests, an on-ice Illinois agility test with and without a puck) and off-ice tests consisting of non-arm swing countermovement jumps (CMJs), broad jumps, and pull-ups. Pearson correlation showed that the acceleration performance of elite players was related to the CMJ (r = -0.46) and the broad jump (r = -0.31). Sub-elite players showed stronger dependence of the 30-m sprint on the CMJ (r = -0.77) and the broad jump (r = -0.43), the relation of pulls ups (r = -0.62) and the CMJ (r = -0.50) to the 6 x 54-m test, yet no association to acceleration. Elite players differ between off-ice and on-ice performance constraints, where their skating sprint is less related to their vertical and horizontal take-off abilities than in sub-elite players. Sub-elite players' off-ice power determines their sprint and repeated sprint performance. COD performance of elite and sub-elite players is based on different conditioning constraints.
- Publikační typ
- časopisecké články MeSH
Microbial mats are abundant in many alpine and polar aquatic ecosystems. With warmer temperatures, new hydrologic pathways are developing in these regions and increasing dissolved nutrient fluxes. In the McMurdo Dry Valleys, thermokarsting may release both nutrients and sediment, and has the potential to influence mats in glacial meltwater streams. To test the role of nutrient inputs on community structure, we created nutrient diffusing substrata (NDS) with agar enriched in N, P and N + P, with controls, and deployed them into two Dry Valley streams. We found N amendments (N and N + P) to have greater chlorophyll-a concentrations, total algal biovolume, more fine filamentous cyanobacteria and a higher proportion of live diatoms than other treatments. Furthermore, N treatments were substantially elevated in Bacteroidetes and the small diatom, Fistulifera pelliculosa. On the other hand, species richness was almost double in P and N + P treatments over others, and coccoid green algae and Proteobacteria were more abundant in both streams. Collectively, these data suggest that nutrients have the potential to stimulate growth and alter community structure in glacial meltwater stream microbial mats, and the recent erosion of permafrost and accelerated glacial melt will likely impact resident biota in polar lotic systems here and elsewhere.
- MeSH
- chlorofyl analýza MeSH
- Chlorophyta metabolismus MeSH
- dusík analýza MeSH
- ekosystém MeSH
- fosfor analýza MeSH
- ledový příkrov mikrobiologie MeSH
- Proteobacteria izolace a purifikace metabolismus MeSH
- řeky mikrobiologie MeSH
- rozsivky izolace a purifikace metabolismus MeSH
- sinice izolace a purifikace metabolismus MeSH
- společenstvo MeSH
- teplota MeSH
- Publikační typ
- časopisecké články MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
- Geografické názvy
- Antarktida MeSH
The aim of this study was to characterize an in vitro modulating effect of three commensal Lactobacillus strains on cellular differentiation of non-transformed crypt-like rat small intestinal cell line IEC-18. IEC-18 was grown on extracellular matrix, with or without presence of Lactobacillus strains. Gene expression of IEC-18 bacterial detection system - such as Toll-like receptors TLR-2, TLR-4, signal adapter MyD88, cytoplasmic NOD2 receptor, inflammatory cytokines IL-18, IL-1beta, chemokine IL-8 and enzyme caspase-1 - was evaluated using real-time PCR. Expression and localization of TLR-2, TLR-4, IL-18 and caspase-1 proteins was demonstrated by Western blotting and immunofluorescent staining. Secretion of IL-18 to apical and basolateral surfaces was assayed by ELISA. Our results suggested that L. casei LOCK0919 accelerated differentiation of IEC-18 by stimulating TLR-2, TLR-4, MyD88, IL-18, caspase-1 mRNAs and proteins. L. casei LOCK0919 increased expression and transfer of villin and beta-catenin from cytoplasm to cell membrane. Presence of L. rhamnosus LOCK0900 resulted in detachment of IEC-18 layer from extracellular matrix leading to induction of IL-1beta, of TLR-2 and IL-8 mRNAs and stimulation of MyD88, caspase-1 and cytosolic receptor NOD2 mRNAs. L. rhamnosus LOCK0908 was not recognized by TLR-2 or TLR-4 receptors. Lactobacilli-IEC-18 crosstalk enhanced immune and barrier mucosal functions.
- MeSH
- beta-katenin biosyntéza MeSH
- buněčná diferenciace účinky léků MeSH
- cytokiny biosyntéza MeSH
- epitelové buňky účinky léků MeSH
- interleukin-18 biosyntéza MeSH
- kaspasa 1 biosyntéza MeSH
- krysa rodu rattus MeSH
- Lacticaseibacillus rhamnosus * MeSH
- Lactobacillus casei * MeSH
- messenger RNA biosyntéza MeSH
- mikrofilamentové proteiny biosyntéza MeSH
- probiotika farmakologie MeSH
- regulace genové exprese účinky léků MeSH
- střevní sliznice cytologie účinky léků MeSH
- subcelulární frakce metabolismus MeSH
- toll-like receptory biosyntéza účinky léků MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- MeSH
- bolesti hlavy * farmakoterapie MeSH
- chronická bolest farmakoterapie MeSH
- dítě MeSH
- kongresy jako téma MeSH
- lidé MeSH
- management bolesti * MeSH
- migréna farmakoterapie MeSH
- primární bolesti hlavy farmakoterapie MeSH
- průlomová bolest farmakoterapie MeSH
- radiochirurgie metody MeSH
- sekundární bolesti hlavy farmakoterapie MeSH
- spánek MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
Úvod: Invazivní mykotické infekce (IFI) jsou obávanou komplikací léčby pacientů s onkologickou diagnózou. Jejich mortalita dosahuje až 80 %, nezanedbatelná je i ekonomická náročnost léčby. Incidence IFI v rámci jednotlivých pracovišť se může lišit v závislosti na skladbě pacientů, antibiotické a antimykotické lékové politice a epidemiologických podmínkách pracoviště. Cílem této práce bylo zjistit incidenci IFI na pracovišti po osmi letech od jeho založení. Metody: Retrospektivně autoři zhodnotili klinická, mikrobiologická a radiologická data pacientů se spotřebou systémových antimykotik a na tyto pacienty uplatnili konsensuální diagnostická kritéria IFI. Výsledky: V uvedeném období bylo na klinice léčeno 562 pacientů, z nichž u 14 (2,5 %) autoři potvrdili diagnózu IFI. U deseti pacientů se jednalo o IFI jistou, u jednoho pravděpodobnou a u tří možnou. V devíti případech se jednalo o invazivní kandidózu (IC), ve čtyřech případech o invazivní aspergilózu (IA) a jeden pacient prodělal invazivní zygomykózu. Původcem IC byly v šesti případech kmeny C. non albicans, ve třech případech C. albicans. Základní diagnóza akutní myeloidní leukémie nebo myelodysplastického syndromu (AML/MDS) a meduloblastomu (MBL) byla spojena s 11,9, resp. 5,4krát zvýšeným rizikem IFI. Profylakticky podané antimykotikum u kolonizovaných pacientů selhalo v prevenci IFI. V důsledku IFI zemřeli celkem dva pacienti (14,2 %). Autoři nepozorovali rozdíl v mortalitě mezi neutropenickými a non-neutropenickými pacienty. Závěr: Incidence IFI v souboru se neliší od publikovaných dat. Závažným nálezem je tendence k nárůstu IFI v posledních dvou letech a vysoký podíl kmenů C. non albicans mezi původci invazivních kandidóz. Pro nejrizikovější skupinu pacientů s AML/MDS může být přínosem primární antimykotická profylaxe. Ta by optimálně měla být prováděna v podmínkách multicentrické kontrolované studie.
Introduction: Invasive mycotic infections (IFI) are redoubtable complications in the therapy of patients with oncology diagnosis. Their lethality reaches up to 80% and the economic aspects of the therapy are also not negligible. Incidence of IFI within the framework of individual workplaces may differ in relation to the structure of the patients' cohort, antibiotic and antimycotic therapeutic policy and epidemiological conditions of the workplace. The objective of this investigation was to determine incidence of IFI at the authors' workplace weight years since the foundation. Methods: The authors retrospectively evaluated clinical, microbiological and radio-logical data of the patients with consumption of systemic antimycotics and applied consensual diagnostic criteria of IFI for all of them. Results: In the given period of time 562 patients háve been treated at the clinic, 14 of them (2.5%) having established the diagnosis of IFI. In 10 of the patients IFI diagnosis was certain, probable in one patient and possible in three others. In nice cases there was an invasive candidosis (IC), in four cases invasive aspergillosis (IA) and one patient suffered from invasive zygomycosis. The proved agents in six cases of IC were strains of C. non albicans, and C. albicans in three patients. The basic diagnosis of acu-te myeloid leukemia or myelodysplastic syndrome (AML/MDS) and meduUoblastoma (MBL) was associated with 11.9 and 5.4-fold increased risk of IFI, respectively. Prophylactic administration of ancimycotics in the colonized patients failed in the prevention of IFI. Two patients died due to IFI (14.2%). There háve not been any difference in mortality between neutropenic and non- neutropenic patients. Conclusion: The incidence of IFI has not differed from the published data. The ten-dency for Íncreasing IFI incidence over the last two years and a high proportion of C. non albicans strains among agents of invasive candidoses represents a serious finding. For the patients with AML/MDS who are at the highest risk, primary antimycotic prophylaxis may be useful. It should be at best performed in conditions of muticentric controlled study.
- MeSH
- akcelerovaná fáze myeloidní leukemie komplikace mikrobiologie MeSH
- chemoprofylaxe metody MeSH
- dítě MeSH
- imunosupresivní léčba škodlivé účinky MeSH
- lidé MeSH
- myelodysplastické syndromy komplikace mikrobiologie MeSH
- mykózy epidemiologie klasifikace MeSH
- nádory klasifikace komplikace mikrobiologie MeSH
- retrospektivní studie MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
... Invited Lectures -- IL1 New Researches on the Man in the Ice 2 -- Spindler K., Innsbruck -- IL3 Physical ... ... Wien -- QART P5 The Field-Symmetry as an Early Indicator for Technical Problems 196 of a Linac Accelerator ... ... of a Treatment Planning System and Dose Profiles Measured with Two Photon Energies of a Linear Accelerator ...
xxii, 430 s. : il., tab. ; 21 cm
- MeSH
- biofyzika MeSH
- radiografie MeSH
- radiologie MeSH
- radioterapie MeSH
- Publikační typ
- kongresy MeSH
- sborníky MeSH
