(18)O-isotope labelled titania (anatase, rutile) was synthesized. The products were characterized by Raman spectra together with their quantum chemical modelling. The interaction with carbon dioxide was investigated using high-resolution FTIR spectroscopy, and the oxygen isotope exchange at the Ti(18)O(2)/C(16)O(2) interface was elucidated.

• Publikační typ
• časopisecké články MeSH

Six representative isotope-labeled samples of titanium dioxide were synthesized: Ti(16)O(2), Ti(17)O(2) and Ti(18)O(2), each in anatase and rutile forms. Their Raman scattering was analyzed at temperatures down to 5 K. Spectral assignment was supported by numerical simulation using DFT calculations. The combination of experimental and theoretical Raman frequencies with the corresponding isotopic shifts allowed us to address various still-open questions about the second-order Raman scattering in rutile, and the analysis of overlapping features in the anatase spectrum.

• MeSH
• izotopy kyslíku chemie   MeSH
• kvantová teorie MeSH
• Ramanova spektroskopie MeSH
• teplota MeSH
• titan chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• izotopy kyslíku MeSH
• titan MeSH
• titanium dioxide MeSH Prohlížeč

Stable isotopes of hydrogen (2H) and oxygen (18O) of the water molecule were used to assess the relationship between precipitation, surface water and groundwater in a large Russia/Ukraine trans-boundary river basin. Precipitation was sampled from November 2013 to February 2015, and surface water and groundwater were sampled during high and low flow in 2014. A local meteoric water line was defined for the Ukrainian part of the basin. The isotopic seasonality in precipitation was evident with depletion in heavy isotopes in November-March and an enrichment in April-October, indicating continental and temperature effects. Surface water was enriched in stable water isotopes from upstream to downstream sites due to progressive evaporation. Stable water isotopes in groundwater indicated that recharge occurs mainly during winter and spring. A one-year data set is probably not sufficient to report the seasonality of groundwater recharge, but this survey can be used to identify the stable water isotopes framework in a weakly gauged basin for further hydrological and geochemical studies.

• Klíčová slova
• Groundwater, Russian Federation, Ukraine, hydrogen-2, hydrological processes, isotope hydrology, oxygen-18, precipitation, surface water,
• MeSH
• deuterium analýza   MeSH
• hydrologie metody   MeSH
• izotopy kyslíku analýza   MeSH
• monitorování životního prostředí metody   MeSH
• podzemní voda analýza   chemie   MeSH
• řeky chemie   MeSH
• roční období MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Rusko MeSH
• Ukrajina MeSH
• Názvy látek
• deuterium MeSH
• izotopy kyslíku MeSH
• Oxygen-18 MeSH Prohlížeč

RATIONALE: Tracing isotopically labeled water into proteins allows for the detection of species-specific metabolic activity in complex communities. However, a stress response may alter the newly synthesized proteins. METHODS: We traced 18-oxygen from heavy water into proteins of Escherichia coli K12 grown from permissive to retardant temperatures. All samples were analyzed using UPLC/Orbitrap Q-Exactive-MS/MS operating in positive electrospray ionization mode. RESULTS: We found that warmer temperatures resulted in significantly (P-value < 0.05) higher incorporation of 18-oxygen as seen by both substrate utilization as relative isotope abundance (RIA) and growth as labeling ratio (LR). However, the absolute number of peptides with incorporation of 18-oxygen showed no significant correlation to temperature, potentially caused by the synthesis of different proteins at low temperatures, namely, proteins related to cold stress response. CONCLUSIONS: Our results unveil the species-specific cold stress response of E. coli K12 that could be misinterpreted as general growth; this is why the quantity as RIA and LR but also the quality as absolute number of peptides with incorporation (relative abundance, RA) and their function must be considered to fully understand the activity of microbial communities.

• MeSH
• Escherichia coli K12 * chemie   metabolismus   fyziologie   MeSH
• izotopové značení metody   MeSH
• izotopy kyslíku * analýza   metabolismus   MeSH
• nízká teplota MeSH
• proteiny z Escherichia coli * analýza   chemie   metabolismus   MeSH
• reakce na chladový šok fyziologie   MeSH
• tandemová hmotnostní spektrometrie metody   MeSH
• vysokoúčinná kapalinová chromatografie metody   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• izotopy kyslíku * MeSH
• Oxygen-18 MeSH Prohlížeč
• proteiny z Escherichia coli * MeSH

Purpurin 18 derivatives with a polyethylene glycol (PEG) linker were synthesized as novel photosensitizers (PSs) with the goal of using them in photodynamic therapy (PDT) for cancer. These compounds, derived from a second-generation PS, exhibit absorption at long wavelengths; considerable singlet oxygen generation and, in contrast to purpurin 18, have higher hydrophilicity due to decreased logP. Together, these properties make them potentially ideal PSs. To verify this, we screened the developed compounds for cell uptake, intracellular localization, antitumor activity and induced cell death type. All of the tested compounds were taken up into cancer cells of various origin and localized in organelles known to be important PDT targets, specifically, mitochondria and the endoplasmic reticulum. The incorporation of a zinc ion and PEGylation significantly enhanced the photosensitizing efficacy, decreasing IC50 (half maximal inhibitory compound concentration) in HeLa cells by up to 170 times compared with the parental purpurin 18. At effective PDT concentrations, the predominant type of induced cell death was apoptosis. Overall, our results show that the PEGylated derivatives presented have significant potential as novel PSs with substantially augmented phototoxicity for application in the PDT of cervical, prostate, pancreatic and breast cancer.

• Klíčová slova
• PEGylated purpurin 18, apoptosis, cancer cells, cytotoxicity, flow cytometry, live-cell fluorescence microscopy, photodynamic therapy, photosensitizer, phototoxicity, singlet oxygen,
• MeSH
• fluorescenční mikroskopie MeSH
• fotochemoterapie metody   MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• porfyriny chemie   MeSH
• průtoková cytometrie MeSH
• rozpustnost MeSH
• singletový kyslík chemie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• porfyriny MeSH
• purpurin 18 MeSH Prohlížeč
• singletový kyslík MeSH

Recent experiments have underlined the potential of δ2H in tree-ring cellulose as a physiological indicator of shifts in autotrophic versus heterotrophic processes (i.e., the use of fresh versus stored non-structural carbohydrates). However, the impact of these processes has not yet been quantified under natural conditions. Defoliator outbreaks disrupt tree functioning and carbon assimilation, stimulating remobilization, therefore providing a unique opportunity to improve our understanding of changes in δ2H. By exploring a 700-year tree-ring isotope chronology from Switzerland, we assessed the impact of 79 larch budmoth (LBM, Zeiraphera griseana [Hübner]) outbreaks on the growth of its host tree species, Larix decidua [Mill]. The LBM outbreaks significantly altered the tree-ring isotopic signature, creating a 2H-enrichment and an 18O- and 13C-depletion. Changes in tree physiological functioning in outbreak years are shown by the decoupling of δ2H and δ18O (O-H relationship), in contrast to the positive correlation in non-outbreak years. Across the centuries, the O-H relationship in outbreak years was not significantly affected by temperature, indicating that non-climatic physiological processes dominate over climate in determining δ2H. We conclude that the combination of these isotopic parameters can serve as a metric for assessing changes in physiological mechanisms over time.

• Klíčová slova
• Zeiraphera griseana, dendroecology, deuterium, ecophysiology, insect defoliation, insect outbreak, plant–pathogen interaction, stable isotope, tree physiology, tree-ring cellulose,
• MeSH
• izotopy kyslíku analýza   MeSH
• izotopy uhlíku analýza   MeSH
• modřín * fyziologie   MeSH
• můry * fyziologie   MeSH
• stromy MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Švýcarsko MeSH
• Názvy látek
• izotopy kyslíku MeSH
• izotopy uhlíku MeSH
• Oxygen-18 MeSH Prohlížeč

The Canary Islands, an archipelago east of Morocco's Atlantic coast, present steep altitudinal gradients covering various climatic zones from hot deserts to subalpine Mediterranean, passing through fog-influenced cloud forests. Unlike the majority of the Canarian flora, Pinus canariensis C. Sm. ex DC. in Buch grow along most of these gradients, allowing the study of plant functioning in contrasting ecosystems. Here we assess the water sources (precipitation, fog) of P. canariensis and its physiological behavior in its different natural environments. We analyzed carbon and oxygen isotope ratios of water and organics from atmosphere, soil and different plant organs and tissues (including 10-year annual time series of tree-ring cellulose) of six sites from 480 to 1990 m above sea level on the Canary Island La Palma. We found a decreasing δ18O trend in source water that was overridden by an increasing δ18O trend in needle water, leaf assimilates and tree-ring cellulose with increasing altitude, suggesting site-specific tree physiological responses to relative humidity. Fog-influenced and fog-free sites showed similar δ13C values, suggesting photosynthetic activity to be limited by stomatal closure and irradiance at certain periods. In addition, we observed an 18O-depletion (fog-free and timberline sites) and 13C-depletion (fog-influenced and fog-free sites) in latewood compared with earlywood caused by seasonal differences in: (i) water uptake (i.e., deeper ground water during summer drought, fog water frequency and interception) and (ii) meteorological conditions (stem radial growth and latewood δ18O correlated with winter precipitation). In addition, we found evidence for foliar water uptake and strong isotopic gradients along the pine needle axis in water and assimilates. These gradients are likely the reason for an unexpected underestimation of pine needle water δ18O when applying standard leaf water δ18O models. Our results indicate that soil water availability and air humidity conditions are the main drivers of the physiological behavior of pine along the Canary Island's altitudinal gradients.

• Klíčová slova
• Pinus canariensis, Canary Islands, cloud forest, drought, relative humidity, stable isotopes, tree rings, vapor pressure deficit,
• MeSH
• borovice * MeSH
• ekosystém MeSH
• izotopy kyslíku analýza   MeSH
• izotopy uhlíku analýza   MeSH
• stromy MeSH
• voda * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Španělsko MeSH
• Názvy látek
• izotopy kyslíku MeSH
• izotopy uhlíku MeSH
• Oxygen-18 MeSH Prohlížeč
• voda * MeSH

Perinatal hypoxic-ischemic insult (HII) is one of the main devastating causes of morbidity and mortality in newborns. HII induces brain injury which evolves to neurological sequelae later in life. Hypothermia is the only therapeutic approach available capable of diminishing brain impairment after HII. Finding a novel therapeutic method to reduce the severity of brain injury and its consequences is critical in neonatology. The present paper aimed to evaluate the effect of sulforaphane (SFN) pre-treatment on glucose metabolism, neurodegeneration, and functional outcome at the acute, sub-acute, and sub-chronic time intervals in the experimental model of perinatal hypoxic-ischemic insult in rats. To estimate the effect of SFN on brain glucose uptake we have performed 18F-deoxyglucose (FDG) microCT/PET. The activity of FDG was determined in the hippocampus and sensorimotor cortex. Neurodegeneration was assessed by histological analysis of Nissl-stained brain sections. To investigate functional outcomes a battery of behavioral tests was employed. We have shown that although SFN possesses a protective effect on glucose uptake in the ischemic hippocampus 24 h and 1 week after HII, no effect has been observed in the motor cortex. We have further shown that the ischemic hippocampal formation tends to be thinner in HIE and SFN treatment tends to reverse this pattern. We have observed subtle chronic movement deficit after HII detected by ladder rung walking test with no protective effect of SFN. SFN should be thus considered as a potent neuroprotective drug with the capability to interfere with pathophysiological processes triggered by perinatal hypoxic-ischemic insult.

• MeSH
• fluorodeoxyglukosa F18 terapeutické užití   MeSH
• glukosa MeSH
• hypoxie komplikace   MeSH
• isothiokyanatany MeSH
• krysa rodu Rattus MeSH
• mozek diagnostické zobrazování   patologie   MeSH
• mozková hypoxie a ischemie * diagnostické zobrazování   farmakoterapie   MeSH
• novorozená zvířata MeSH
• poranění mozku * MeSH
• sulfoxidy MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• fluorodeoxyglukosa F18 MeSH
• glukosa MeSH
• isothiokyanatany MeSH
• sulforaphane MeSH Prohlížeč
• sulfoxidy MeSH

The genus Tetrahymena (Ciliophora, Oligohymenophorea) probably represents the best studied ciliate genus. At present, more than forty species have been described. All are colorless, i.e. they do not harbor symbiotic algae, and as aerobes they need at least microaerobic habitats. Here, we present the morphological and molecular description of the first green representative, Tetrahymena utriculariae n. sp., living in symbiosis with endosymbiotic algae identified as Micractinium sp. (Chlorophyta). The full life cycle of the ciliate species is documented, including trophonts and theronts, conjugating cells, resting cysts and dividers. This species has been discovered in an exotic habitat, namely in traps of the carnivorous aquatic plant Utricularia reflexa (originating from Okavango Delta, Botswana). Green ciliates live as commensals of the plant in this anoxic habitat. Ciliates are bacterivorous, however, symbiosis with algae is needed to satisfy cell metabolism but also to gain oxygen from symbionts. When ciliates are cultivated outside their natural habitat under aerobic conditions and fed with saturating bacterial food, they gradually become aposymbiotic. Based on phylogenetic analyses of 18S rRNA and mitochondrial cox1 genes T. utriculariae forms a sister group to Tetrahymena thermophila.

• Klíčová slova
• Utricularia, Ciliates, Tetrahymenida, life cycle, mixotrophy, symbiotic algae,
• MeSH
• cévnaté rostliny parazitologie   MeSH
• Chlorophyta parazitologie   MeSH
• Ciliophora klasifikace   metabolismus   fyziologie   MeSH
• ekologie MeSH
• ekosystém MeSH
• fylogeneze * MeSH
• kyslík metabolismus   MeSH
• mitochondrie genetika   MeSH
• Oligohymenophorea klasifikace   MeSH
• protozoální DNA MeSH
• RNA ribozomální 18S genetika   MeSH
• rostliny parazitologie   MeSH
• sekvence nukleotidů MeSH
• stadia vývoje MeSH
• symbióza fyziologie   MeSH
• Tetrahymena thermophila klasifikace   genetika   MeSH
• Tetrahymena klasifikace   cytologie   izolace a purifikace   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• kyslík MeSH
• protozoální DNA MeSH
• RNA ribozomální 18S MeSH

• Klíčová slova
• EXERTION *, HEART CATHETERIZATION *, HYPERTENSION, PULMONARY *, OXYGEN *, PULMONARY CIRCULATION *, RESERPINE *, SILICOSIS *, TOLAZOLINE *, VASOMOTOR SYSTEM *,
• MeSH
• hypertenze * MeSH
• kyslík * MeSH
• lidé MeSH
• plíce * MeSH
• plicní hypertenze * MeSH
• plicní oběh * MeSH
• reserpin * MeSH
• silikóza * MeSH
• srdeční katetrizace * MeSH
• tělesná námaha * MeSH
• tolazolin * MeSH
• vazomotorický systém * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• kyslík * MeSH
• reserpin * MeSH
• tolazolin * MeSH