Search results for "I.2"
showing 10 items of 662 documents
TiO2 in Organic Photosynthesis: Sunlight Induced Functionalization of Heterocyclic Bases in the Presence of TiO2
2010
Ossidazione fotocatalitica del glucosio in presenza di TiO2
2014
Ossidazione selettiva di alcoli aromatici ad aldeidi in sospensioni acquose di TiO2 anatasio e rutilo
2008
Elemental Bromine Production by TiO2 Photocatalysis and/or Ozonation
2016
Significant production of elemental bromine (Br2 ) was observed for the first time when treating bromide containing solutions at acidic pH, with TiO2 photocatalyst, ozone, or a combination thereof. Br2 selectivities up to approximately 85 % were obtained and the corresponding bromine mass balance values satisfied. The process is general and may be applied at a laboratory scale for green bromination reactions, or industrially as a cheap, safe, and environmentally sustainable alternative to the currently applied bromine production methods.
Mechanistic aspects of oxalic acid oxidation by photocatalysis and ozonation
2008
Oxalic acid has been oxidised in acidic aqueous solutions (pH 3) using photocatalysis and ozonation alone or coupled. The simultaneous presence of ozone, titanium dioxide and near UV irradiation increases the oxidation rate of oxalic acid to values greater than those deriving from the single contributions of photocatalysis and ozonation. In particular in the present paper ozonation alone, heterogeneous photocatalysis and also combined ozonation with heterogeneous photocatalysis have been used for the oxidation of oxalic acid at acidic pH in the presence of TiO2 Degussa P25. A likely mechanism, able to explain both the homogeneous and heterogeneous processes, is discussed.
Stoichiometry-related Auger lineshapes in titanium oxides: Influence of valence-band profile and of Coster-Kronig processes
2004
International audience; The ability to determine the nature and the occurrence of defects is a central need of ceramic surface chemistry. In titanium oxides, the Ti-LMV Auger decays line shape is very sensitive to the titanium degree of oxidation, and has long been empirically used as a qualitative probe of the stoichiometry. In the present work, resonant Auger and resonant valence-band measurements at the Ti-L2,3 edges in TiO2, TiO2–x and metallic titanium provide a clear evidence that the evolutions of the Ti-LMV Auger line shape are due to drastic changes in the valence-band profile and in the probability of L2L3V Coster-Kronig decay processes when a fraction of titanium ions is reduced.…
Evapotranspiration simulations in ISIMIP2a-Evaluation of spatio-temporal characteristics with a comprehensive ensemble of independent datasets
2018
Actual land evapotranspiration (ET) is a key component of the global hydrological cycle and anessential variable determining the evolution of hydrological extreme events under different climate change scenarios. However, recently available ET products show persistent uncertainties thatare impeding a precise attribution of human-induced climate change. Here, we aim at comparing arange of independent global monthly land ET estimates with historical model simulations from theglobal water, agriculture, and biomes sectors participating in the second phase of the Inter-SectoralImpact Model Intercomparison Project (ISIMIP2a). Among the independent estimates, we use theEartH2Observe Tier-1 dataset …
Between Scylla and Charibdis: eIF2α kinases as targets for cancer chemotherapy
2011
[EN] The eIF2 alpha kinases integrate translation initiation rates with nutrient availability, thus allowing cells to adapt to nutrient scarcity. Recent evidence has uncovered new functions of these kinases in tumour cell biology, ranging from regulation of cell cycle progression, maintenance of genome stability, control of apoptosis, and cell survival under nutrient stress and hypoxia. Accordingly, active eIF2 alpha kinases modulate the antineoplasic activity of several antitumour drugs, either by exacerbating their cytotoxic effect or by promoting chemoresistance. Understanding of eIF2 alpha kinases molecular roles may provide mechanistic insights into how tumour cells sense and adapt to …
Endoplasmic Reticulum Stress Inhibition Protects against Excitotoxic Neuronal Injury in the Rat Brain
2007
Elevated brain glutamate with activation of neuronal glutamate receptors accompanies neurological disorders, such as epilepsy and brain trauma. However, the mechanisms by which excitotoxicity triggers neuronal injury are not fully understood. We have studied the glutamate receptor agonist kainic acid (KA) inducing seizures and excitotoxic cell death. KA caused the disintegration of the endoplasmic reticulum (ER) membrane in hippocampal neurons and ER stress with the activation of the ER proteins Bip, Chop, and caspase-12. Salubrinal, inhibiting eIF2α (eukaryotic translation initiation factor 2 subunit α) dephosphorylation, significantly reduced KA-induced ER stress and neuronal deathin vivo…
Poliaromātisku un polidentātu ligandu sintēze un to izmantošana porainu metālorganisko ietvaru iegūšanai
2018
Poliaromātisku un polidentātu ligandu sintēze un to izmantošana porainu metālorganisko ietvaru iegūšanai. Petkus J., zinātniskais vadītājs Dr. ķīm. Šubins K., konsultēja Dr. h. ķīm. Zicmanis A. Bakalaura darbs, 44 lappuses, 43 attēli, 3 tabulas, 36 literatūras avoti. Latviešu valodā. Bakalaura darbs ir veltīts jaunu heterotriangulēnu atvasinājumu iegūšanas sintēžu uzlabošanai.