Radio frequency plasma is one of the means to modify the polymer surface namely in the activation of polypropylene membranes (PPM) with O2 plasma. Activated membranes were deposited with TiO2 nanoparticles by the dip coating method and the bare sample and modified sample (PPM5-TiO2) were irradiated by UV lamps for 20-120 min. Characterization techniques such as X-ray diffraction (XRD), Attenuated total reflection technique- Fourier transform infrared spectroscopy (ATR-FTIR), Thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), Scanning electron microscope (SEM) and water contact angle (WCA) measurements were applied to study the alteration of ensuing membrane surface properties which shows the nanoparticles on the sample surface including the presence of Ti on PPM. The WCA decreased from 135° (PPM) to 90° (PPM5-TiO2) and after UV irradiation, the WCA of PPM5-TiO2 diminished from 90° to 40°.

• MeSH
• difrakce rentgenového záření MeSH
• fotoelektronová spektroskopie MeSH
• kyslík chemie   MeSH
• membrány umělé * MeSH
• nanočástice chemie   MeSH
• plazmové plyny chemie   MeSH
• polypropyleny chemie   MeSH
• smáčivost MeSH
• spektroskopie infračervená s Fourierovou transformací MeSH
• teplota MeSH
• termogravimetrie MeSH
• titan chemie   MeSH
• voda chemie   MeSH
• Publikační typ
• časopisecké články MeSH

A barley (Hordeum vulgare) plasma membrane type aquaporin, HvPIP2;5, was identified as an H2 O2 permeable aquaporin among 21 barley and rice PIPs examined in the heterologous expression system using Saccharomyces cerevisiae. Four TIPs were also detected as H2 O2 -transporting aquaporins among 15 barley and rice TIPs. Influx of H2 O2 into yeast cells expressing HvPIP2;5 was determined with a florescent-dye-based assay. Indirect immunofluorescence indicated that the expression of HvPIP2;5 protein was ubiquitous in root tissues, and was also weakly observed in leaf epidermal cells and cells in the vascular bundle. Point mutated variants of HvPIP2;5 were generated by the site-directed mutagenesis. Growth assays of yeast cells expressing these mutated HvPIP2;5 proteins suggested that Ser-126 in HvPIP2;5 has a large impact on H2 O2 transport with a minor influence on the HvPIP2;5-mediated water transport.

• MeSH
• akvaporiny genetika   metabolismus   MeSH
• biologický transport MeSH
• buněčná membrána metabolismus   MeSH
• epidermis rostlin genetika   metabolismus   MeSH
• exprese genu MeSH
• ječmen (rod) cytologie   genetika   metabolismus   MeSH
• kořeny rostlin genetika   metabolismus   MeSH
• listy rostlin genetika   metabolismus   MeSH
• mutace MeSH
• mutageneze cílená MeSH
• orgánová specificita MeSH
• peroxid vodíku metabolismus   MeSH
• regulace genové exprese u rostlin * MeSH
• rostlinné proteiny genetika   metabolismus   MeSH
• rýže (rod) cytologie   genetika   metabolismus   MeSH
• Saccharomyces cerevisiae cytologie   genetika   metabolismus   MeSH
• serin metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH

The renewable evolution in the energy industry and the depletion of natural resources are putting pressure on the waste industry to shift towards flexible treatment technologies with efficient materials and/or energy recovery. In this context, a thermochemical conversion method of recent interest is plasma gasification, which is capable of producing syngas from a wide variety of waste streams. The produced syngas can be valorized for both energetic (heat and/or electricity) and chemical (ammonia, hydrogen or liquid hydrocarbons) end-purposes. This paper evaluates the performance of experiments on a single-stage plasma gasification system for the treatment of refuse-derived fuel (RDF) from excavated waste. A comparative analysis of the syngas characteristics and process yields was done for seven cases with different types of gasifying agents (CO2+O2, H2O, CO2+H2O and O2+H2O). The syngas compositions were compared to the thermodynamic equilibrium compositions and the performance of the single-stage plasma gasification of RDF was compared to that of similar experiments with biomass and to the performance of a two-stage plasma gasification process with RDF. The temperature range of the experiment was from 1400 to 1600 K and for all cases, a medium calorific value syngas was produced with lower heating values up to 10.9 MJ/Nm(3), low levels of tar, high levels of CO and H2 and which composition was in good agreement to the equilibrium composition. The carbon conversion efficiency ranged from 80% to 100% and maximum cold gas efficiency and mechanical gasification efficiency of respectively 56% and 95%, were registered. Overall, the treatment of RDF proved to be less performant than that of biomass in the same system. Compared to a two-stage plasma gasification system, the produced syngas from the single-stage reactor showed more favourable characteristics, while the recovery of the solid residue as a vitrified slag is an advantage of the two-stage set-up.

• MeSH
• biomasa * MeSH
• odpadky - odstraňování metody   MeSH
• plazmové plyny chemie   MeSH
• plyny analýza   MeSH
• tuhý odpad analýza   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The aim of this study was to test the hypothesis that allopurinol ingestion modifies the slow component of •V O2 kinetics and changes plasma oxidative stress markers during severe intensity exercise. Six recreationally active male subjects were randomly assigned to receive a single dose of allopurinol (300 mg) or a placebo in a double-blind, placebo-controlled crossover design, with at least 7 days washout period between the two conditions. Two hours following allopurinol or placebo intake, subjects completed a 6-min bout of cycle exercise with the power output corresponding to 75 % •V O2max. Blood samples were taken prior to commencing the exercise and then 5 minutes upon completion. Allopurinol intake caused increase in resting xanthine and hypoxanthine plasma concentrations, however it did not affect the slow component of oxygen uptake during exercise. Exercise elevated plasma inosine, hypoxanthine, and xanthine. Moreover, exercise induced a decrease in total antioxidant status, and sulfhydryl groups. However, no interaction treatment x time has been observed. Short term severe intensity exercise induces oxidative stress, but xanthine oxidase inhibition does not modify either the kinetics of oxygen consumption or reactive oxygen species overproduction.

• MeSH
• alopurinol aplikace a dávkování   farmakologie   MeSH
• biologické markery krev   MeSH
• cvičení fyziologie   MeSH
• dospělí MeSH
• dvojitá slepá metoda MeSH
• kinetika MeSH
• lidé MeSH
• oxidační stres MeSH
• scavengery volných radikálů farmakologie   MeSH
• spotřeba kyslíku MeSH
• zátěžový test MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH

Beside the key inhibition of acetylcholinesterase (AChE), involvement of oxidative stress in organophosphate (OP)-induced toxicity has been supported by experimental and human studies. On the other hand, according to our best knowledge, possible antioxidant properties of oximes, the only causal antidotes to OP-inhibited AChE, have been examined only by a few studies. Thus, we have determined the effect of four conventional (obidoxime, trimedoxime, pralidoxime, asoxime) and two promising experimental oximes (K027, K203) on dichlorvos (DDVP)-induced oxidative changes in vivo. Wistar rats (5/group) were treated with oxime (5% LD50 i.m) immediately after DDVP challenge (75% LD50 s.c). Oxidative stress biomarkers were determined in plasma and brain 60 min after the treatment: prooxidative-superoxide anion (O2·-) and total oxidative status (TOS); antioxidative-superoxide dismutase (SOD), total thiol (SH) groups, total antioxidant status (TAS) and paraoxonase (PON1); tissue oxidative stress burden-prooxidative-antioxidative balance (PAB) and oxidative stress index (OSI); oxidative tissue damage-malondialdehyde (MDA) and advanced oxidation protein products (AOPP). All oximes were able to attenuate DDVP-induced oxidative stress in rat plasma and brain. Changes of determined parameters in brain were not as prominent as it was seen in plasma. Based on OSI, better abilities of oxime K027, K203 and obidoxime to maintain DDVP-induced oxidative stress in rat brain were shown as compared to trimedoxime, pralidoxime and asoxime. Oximes can influence the complex in vivo redox processes that might contribute to their overall therapeutic efficacy. Further research is needed to understand the underlying molecular mechanisms involved in this phenomenon.

• MeSH
• aryldialkylfosfatasa krev   MeSH
• biologické markery krev   MeSH
• cholinesterasové inhibitory farmakologie   MeSH
• dichlorvos toxicita   MeSH
• krysa rodu rattus MeSH
• malondialdehyd krev   MeSH
• mozek účinky léků   MeSH
• obidoxim chlorid farmakologie   MeSH
• otrava organofosfáty farmakoterapie   MeSH
• oxidační stres účinky léků   MeSH
• oximy farmakologie   MeSH
• pralidoximové sloučeniny MeSH
• pyridinové sloučeniny farmakologie   MeSH
• superoxiddismutasa krev   MeSH
• trimedoxim farmakologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Measurement of parameters of energy requirement, respiratory quotient (RQ), rate of oxygen consumption (VO2) and rate of carbon dioxide production (VCO2) reveal Ringerfundin as an excellent and metabolically stable-acting balanced ionic solution, which does not increase the consumption of O2 or the total energy requirement. In conclusion, Ringerfundin was very well tolerated and in no case were observed undesirable effects.

• MeSH
• acetáty aplikace a dávkování   farmakologie   MeSH
• chlorid draselný farmakologie   MeSH
• chlorid hořečnatý farmakologie   MeSH
• chlorid sodný farmakologie   MeSH
• dospělí MeSH
• dýchání MeSH
• elektrolyty aplikace a dávkování   farmakologie   MeSH
• energetický metabolismus účinky léků   MeSH
• financování organizované MeSH
• glukonáty farmakologie   MeSH
• intravenózní infuze MeSH
• isotonické roztoky MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• nepřímá kalorimetrie MeSH
• octan sodný farmakologie   MeSH
• oxid uhličitý metabolismus   MeSH
• randomizované kontrolované studie jako téma MeSH
• spotřeba kyslíku účinky léků   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH

Singlet molecular oxygen ((1)O2) contributes to protein damage triggering biophysical and biochemical changes that can be related with aging and oxidative stress. Serum albumins, such as bovine serum albumin (BSA), are abundant proteins in blood plasma with different biological functions. This paper presents a kinetic and spectroscopic study of the (1)O2-mediated oxidation of BSA using the tris(2,2'-bipyridine)ruthenium(II) cation [Ru(bpy)3](2+) as sensitizer. BSA quenches efficiently (1)O2 with a total (chemical+physical interaction) rate constant kt(BSA)=7.3(±0.4)×10(8)M(-1)s(-1), where the chemical pathway represented 37% of the interaction. This efficient quenching by BSA indicates the participation of several reactive residues. MALDI-TOF MS analysis of intact BSA confirmed that after oxidation by (1)O2, the mass protein increased the equivalent of 13 oxygen atoms. Time-resolved emission spectra analysis of BSA established that Trp residues were oxidized to N'-formylkynurenine, being the solvent-accessible W134 preferentially oxidized by (1)O2 as compared with the buried W213. MS confirmed oxidation of at least two Tyr residues to form dihydroxyphenylalanine, with a global reactivity towards (1)O2 six-times lower than for Trp residues. Despite the lack of MS evidences, kinetic and chemical analysis also suggested that residues other than Trp and Tyr, e.g. Met, must react with (1)O2. Modeling of the 3D-structure of BSA indicated that the oxidation pattern involves a random distribution of (1)O2 into BSA; allowing also the interaction of (1)O2 with buried residues by its diffusion from the bulk solvent through interconnected internal hydrophilic and hydrophobic grooves.

• MeSH
• 2,2'-dipyridyl analogy a deriváty   farmakologie   MeSH
• hydrofobní a hydrofilní interakce MeSH
• kinetika MeSH
• oxidace-redukce MeSH
• oxidační stres * MeSH
• sérový albumin hovězí chemie   metabolismus   MeSH
• singletový kyslík chemie   metabolismus   MeSH
• spektrometrie hmotnostní - ionizace laserem za účasti matrice MeSH
• stárnutí metabolismus   patologie   MeSH
• tryptofan chemie   metabolismus   MeSH
• vazba proteinů MeSH
• Publikační typ
• časopisecké články MeSH

In this study, evidence is provided on the formation of electronically excited species in human multiple myeloma cells U266 in the growth medium exposed to hydrogen peroxide (H2O2). Two-dimensional imaging of ultra-weak photon emission using highly sensitive charge coupled device camera revealed that the addition of H2O2 to cell suspension caused the formation of triplet excited carbonyls (3)(R = O)*. The kinetics of (3)(R = O)* formation in the real time, as measured by one-dimensional ultra-weak photon emission using low-noise photomultiplier, showed immediate enhancement followed by a slow decay. In parallel to the formation of (3)(R = O)*, the formation of singlet oxygen ((1)O2) in U266 cells caused by the addition of H2O2 was visualized by the imaging of (1)O2 using the green fluorescence of singlet oxygen sensor green detected by confocal laser scanning microscopy. Additionally, the formation of (1)O2 after the addition of H2O2 to cell suspension was detected by electron paramagnetic resonance spin-trapping spectroscopy using 2,2,6,6-tetramethyl-4-piperidone. Presented results indicate that the addition of H2O2 to cell suspension results in the formation of (3)(R = O)* and (1)O2 in U266 cell suspension. The contribution of the cell-free medium to the formation of electronically excited species was discussed.

• MeSH
• elektrofyziologické jevy * účinky léků   MeSH
• elektronová paramagnetická rezonance MeSH
• konfokální mikroskopie MeSH
• lidé MeSH
• mnohočetný myelom metabolismus   MeSH
• nádorové buněčné linie MeSH
• nádorové buňky kultivované MeSH
• peroxid vodíku metabolismus   farmakologie   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• viabilita buněk účinky léků   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Zhruba u jednoho z deseti pacientů podrobujících se větším nekardiálním operacím dochází v prvních pooperačních dnech k abnormálnímu vzestupu hladiny vysoce citlivého srdečního troponinu, nasvědčujícímu poranění myokardu. Většina těchto pacientů nemá příznaky ani známky ischemie nebo infarktu myokardu. Přesto mají zvýšené riziko 30denní a dlouhodobé úmrtnosti ze všech příčin a riziko zvýšeného výskytu závažných komplikací srovnatelné s prognózou infarktu myokardu typu 2. Toto poranění myokardu se považuje za následek kritické nerovnováhy mezi potřebou a nabídkou O2 v myokardu. Po přehledu patofyziologie, klinické problematiky a prevence této komplikace je navrženo alternativní vysvětlení mechanismů způsobujících nekrózu kardiomyocytů se zaměřením na roli zánětu.

In approximately one in ten patients undergoing major non-cardiac surgery, abnormal increases in plasma levels of high sensitivity cardiac troponin occur during the first postoperative days, suggesting postoperative myocardial injury. Most of these patients have no signs or symptoms of myocardial ischaemia or infarction. Nonetheless, they are at increased risk of both 30-day and long-term all-cause mortality as well as higher incidence of major cardiovascular adverse events, comparable to type 2 postoperative myocardial infarction. The myocardial injury is deemed to result from critical imbalance of myocardial O2 demand and supply. The pathophysiology, clinical implications and prevention of this condition are reviewed, and an alternative interpretation of the mechanisms causing cardiomyocyte necrosis – inflammation – is presented.

• MeSH
• akutní koronární syndrom patofyziologie   MeSH
• ateroskleróza etiologie   MeSH
• chirurgické operační výkony MeSH
• infarkt myokardu etiologie   MeSH
• ischemie MeSH
• lidé MeSH
• perioperační období * MeSH
• poranění srdce * etiologie   komplikace   mortalita   MeSH
• rizikové faktory MeSH
• statiny terapeutické užití   MeSH
• troponin analýza   MeSH
• zánět etiologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• přehledy MeSH

An emerging class of novel heme-based oxygen sensors containing a globin fold binds and senses environmental O2 via a heme iron complex. Structure-function relationships of oxygen sensors containing a heme-bound globin fold are different from those containing heme-bound PAS and GAF folds. It is thus worth reconsidering from an evolutionary perspective how heme-bound proteins with a globin fold similar to that of hemoglobin and myoglobin could act as O2 sensors. Here, we summarize the molecular mechanisms of heme-based oxygen sensors containing a globin fold in an effort to shed light on the O2-sensing properties and O2-stimulated catalytic enhancement observed for these proteins.

• MeSH
• Azotobacter vinelandii enzymologie   MeSH
• Bordetella pertussis enzymologie   MeSH
• chemotaxe MeSH
• Escherichia coli enzymologie   MeSH
• globiny chemie   MeSH
• hem chemie   MeSH
• hemoglobiny chemie   MeSH
• katalytická doména MeSH
• katalýza MeSH
• kyslík chemie   MeSH
• lyasy štěpící vazby P-O chemie   MeSH
• molekulární evoluce MeSH
• molekulární sekvence - údaje MeSH
• myoglobin chemie   MeSH
• proteinkinasy chemie   MeSH
• proteiny z Escherichia coli chemie   MeSH
• regulace genové exprese enzymů * MeSH
• sekvence aminokyselin MeSH
• sekvenční homologie aminokyselin MeSH
• vazba proteinů MeSH
• vazebná místa MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH