Cerium oxide
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Gas sensitive cerium oxide-tungsten oxide core-shell nanowires are synthesized and integrated directly into micromachined platforms via aerosol assisted chemical vapor deposition. Tests to various volatile organic compounds (acetone, ethanol, and toluene) involved in early disease diagnosis demonstrate enhanced sensitivity to acetone for the core-shell structures in contrast to the non-modified materials (i.e., only tungsten oxide or cerium oxide). This is attributed to the high density of oxygen vacancy defects at the shell, as well as the formation of heterojunctions at the core-shell interface, which provide the modified nanowires with 'extra' chemical and electronic sensitization as compared to the non-modified materials.
- MeSH
- aceton metabolismus MeSH
- cer chemie MeSH
- nanodráty chemie MeSH
- oxidy chemie MeSH
- těkavé organické sloučeniny metabolismus MeSH
- wolfram chemie MeSH
- Publikační typ
- časopisecké články MeSH
Magnetic γ-Fe2O3/CeO2 nanoparticles were obtained by precipitation of Ce(NO3)3 with ammonia in the presence of γ-Fe2O3 seeds. The formation of CeO2 nanoparticles on the seeds was confirmed by transmission electron microscopy linked with selected area electron diffraction, energy-dispersive X-ray spectroscopy, electron energy loss spectroscopy, and dynamic light scattering. The γ-Fe2O3/CeO2 particle surface was functionalized with PEG-neridronate to improve the colloidal stability in PBS and biocompatibility. Chemical and in vitro biological assays proved that the nanoparticles, due to the presence of cerium oxide, effectively scavenged radicals, thus decreasing oxidative stress in the model cell line. PEG functionalization of the nanoparticles diminished their in vitro aggregation and facilitated lysosomal cargo degradation in cancer cells during autophagy, which resulted in concentration-dependent cytotoxicity of the nanoparticles. Finally, the iron oxide core allowed easy magnetic separation of the particles from liquid media and may enable monitoring of nanoparticle biodistribution in organisms using magnetic resonance imaging.
This study was a comparison between Ru-catalysts and similar, previously investigated, Pt-catalysts. In this paper, ruthenium catalysts for catalytic wet air oxidation are prepared, characterized and tested. Both catalysts were supported on commercial CeO2 as well as mixed oxide Zr(0.1)(Ce(0.75)Pr(0.25))(0.9)O2. The catalysts were characterized by measuring the oxygen storage capacities (OSC), BET, XRD, FTIR and chemisorption of hydrogen. In addition, the effect of sintering (treatments under H2) was compared with both of the catalysts. The comparison of the results showed that initial intrinsic activity of ruthenium is not significantly influenced by the type of the support, which is contrast to platinum. Furthermore, the particle size of Ru had an important effect on CWAO activity: the higher the particle size, the better the activity. This was different with Pt-catalysts, where the optimal particle size was smaller, having about 15% of metal dispersion.
- MeSH
- cer MeSH
- katalýza MeSH
- kyselina octová chemie MeSH
- oxidace-redukce MeSH
- oxidy MeSH
- platina MeSH
- ruthenium MeSH
- velikost částic MeSH
- vzduch MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
BACKGROUND: Obesity is a risk factor for non-alcoholic fatty liver disease (NAFLD). The disease is associated with impairment of pro/antioxidant equilibrium and the inflammation in liver tissue. The aim of the work was to investigate the anti-inflammatory properties of the nanocrystalline cerium dioxide (nCeO2) on the rat model of NAFLD associated with monosodium glutamate (MSG)-induced obesity. METHODS: The study was carried out on three groups of rats: control, MSG- and MSG+nCeO2. They were injected with saline (control) or MSG. A month after born MSG-rats had been treated with water in a volume of 2.9ml/kg, MSG+CeO2groups - with CeO2intragastrically (i.g.). The anthropometric and carbohydrate metabolism parameters, content of proinflammatory cytokines (interleukin (IL)-1β, IL-12Bp40, interferon-γ (INF-γ)) and anti-inflammatory cytokines (IL-4, IL-10, tumor growth factor-β (TGF-β)) were measured by ELISA. RESULTS: We have demonstrated the anti-obesity effect of nanocrystalline cerium dioxide and for the first time its anti-inflammatory properties. Nanoparticles reduced the content of pro-inflammatory cytokines (IL-1β, IL-12Bp40) in rat serum and restored the level of anti-inflammatory cytokines (IL-4, IL-10, TGF-β) to the control values. CONCLUSION: The precise mechanisms of this phenomenon remain to be unclear but we suppose they are at least partially associated with the strong anti-oxidant action of studied substance. Nanocrystalline cerium dioxide attenuates the inflammatory processes in rat blood that can prevent obesity complications and liver injury.
- MeSH
- antiflogistika farmakologie MeSH
- antioxidancia metabolismus MeSH
- cer farmakologie MeSH
- interferon gama metabolismus MeSH
- interleukin-10 metabolismus MeSH
- interleukin-4 metabolismus MeSH
- krysa rodu rattus MeSH
- nanočástice aplikace a dávkování MeSH
- nealkoholová steatóza jater farmakoterapie metabolismus MeSH
- obezita farmakoterapie metabolismus MeSH
- transformující růstový faktor beta metabolismus MeSH
- zánět farmakoterapie metabolismus MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Nanocrystalline cerium dioxide is able to protect living cells from oxidative stress under the influence of various stress factors, in particular under the one of low temperatures. This study investigates the phase-structural transformations in aqueous solutions containing CeO2 nanoparticles (NPs) and their impact on the cryopreservation process. Differential scanning calorimetry and thermomechanical analysis were used to analyse the phase transitions in aqueous suspensions of CeO2 NPs and aqueous solutions of the cryoprotectant dimethyl sulfoxide (Me2SO) with CeO2 NPs. Various concentrations of CeO2 NPs were tested to observe their effects on the crystallization and melting behaviours. The addition of CeO2 NPs significantly altered the temperatures and enthalpies of melting and crystallization in water. Low concentrations of CeO2 NPs promoted crystallization, while higher concentrations inhibited it, reducing supercooling and recrystallization during thawing. In Me2SO solutions, CeO2 NPs raised the glass transition temperature and affected the recrystallization process, with higher concentrations leading to more pronounced vitrification and reduced recrystallization. We also investigated the regularities of the effect of CeO2 NPs on phase transitions in combined cryoprotective media with Ham's F12, fetal bovine serum and Me2SO, which can be used in future to design the cryopreservation protocols. In the complex media, CeO2 NPs decreased the metastability and altered eutectic crystallization patterns, indicating potential cryoprotective effects. In conclusion, CeO2 NPs modulate the thermophysical properties of cryoprotective solutions, enhancing vitrification and reducing recrystallization, which could improve cryopreservation efficiency. Optimizing NP concentrations is crucial for practical applications in cryopreservation.
- MeSH
- cer * chemie farmakologie MeSH
- diferenciální skenovací kalorimetrie * MeSH
- dimethylsulfoxid * chemie MeSH
- kryoprezervace * metody MeSH
- kryoprotektivní látky * chemie farmakologie MeSH
- krystalizace * MeSH
- nanočástice * chemie MeSH
- tranzitní teplota MeSH
- vitrifikace * účinky léků MeSH
- změna skupenství * MeSH
- Publikační typ
- časopisecké články MeSH
In this study, CeO2 (cerium oxide) nanoparticles were synthesized using Pinus halepensis pollen and were characterized by field emission scanning electron microscopy (FESEM), powder X-ray diffraction (PXRD) and Raman spectroscopy. The results showed that the ensuing CeO2 nanostructures, ranging in size from 5 to 25 nm, had high porosity. Synthesized CeO2 showed the effective catalytic activity towards the photocatalytic removal of dyes. In this work, the photocatalytic activity to removal dye (methyl violet 2B), in the absence of UV radiation, using cerium dioxide nanoparticles (CeO2-NP) was determined. In this research, four main factors such as effect on color, concentration and pH were examined and maximum %R was obtained about was 97% in 75 min in presence of 50 mg of hydrogen peroxide.
- MeSH
- barvicí látky chemie izolace a purifikace MeSH
- borovice MeSH
- cer chemie MeSH
- nanostruktury chemie MeSH
- poréznost MeSH
- Publikační typ
- časopisecké články MeSH
Derivatives of 16alpha-hydroxy-dehydroepiandrosterone, which have an additional oxygen substituent at position 7 (oxo or hydroxy group), were synthesized. Firstly, 17,17-dimethoxyandrost-5-ene-3beta,16alpha-diyl diacetate was prepared and then oxidized with a complex of chromium(VI) oxide and 2,5-dimethylpyrazole to the respective 7-oxo derivative. This key intermediate was both deprotected or reduced by l-Selectride or sodium borohydride in the presence of cerium(III) chloride and then deprotected to give 7-oxo, 7alpha-hydroxy and 7beta-hydroxy derivatives of 16alpha-hydroxy-dehydroepiandrosterone. The target compounds were characterized by (1)H and (13)C NMR spectra and in the form of O-methyloxime-trimethylsilyl derivatives, by gas chromatography/mass spectrometry methods.
- MeSH
- borohydridy MeSH
- cer MeSH
- chloridy MeSH
- dehydroepiandrosteron analogy a deriváty analýza chemie MeSH
- financování organizované MeSH
- hydroxylace MeSH
- indikátory a reagencie MeSH
- magnetická rezonanční spektroskopie MeSH
- molekulární struktura MeSH
- oxidace-redukce MeSH
- plynová chromatografie s hmotnostně spektrometrickou detekcí MeSH
- MeSH
- finanční podpora výzkumu jako téma MeSH
- hypoxie buňky fyziologie účinky léků MeSH
- ikosanoidy biosyntéza MeSH
- králíci fyziologie krev MeSH
- kyselina arachidonová chemická syntéza chemie MeSH
- oxid dusnatý biosyntéza chemie metabolismus MeSH
- synthasa oxidu dusnatého biosyntéza účinky léků MeSH
- vazomotorický systém fyziologie účinky léků MeSH
- zvířata MeSH
- Check Tag
- králíci fyziologie krev MeSH
- zvířata MeSH
- Publikační typ
- srovnávací studie MeSH
