Search results for "Rite"
showing 10 items of 2726 documents
Damipipecolin and damituricin, novel bioactive bromopyrrole alkaloids from the Mediterranean sponge Axinella damicornis
2007
Two new bromopyrrole alkaloids, damipipecolin (1) and damituricin (2), have been isolated from the Mediterranean sponge Axinella damicornis, and their structures established through spectroscopic methods. Compounds 1 and 2 extend the structural variety of the so far known pyrrole alkaloids; in these compounds, the 4-bromopyrrole 2-carboxylic acid is directly condensed with a non-protein cyclic alpha-amino acid, the (2R, 4R)-trans-4-hydroxypipecolic acid and (2R, 4R)-cis-N,N'-dimethyl-4-hydroxyproline (D-turicine) in 1 and 2, respectively. Compounds 1 and 2 were found to display a modulating effect of the serotonin receptor activity in vitro.
Oxidative stress upregulates the NMDA receptor on cerebrovascular endothelium.
2009
N-methyl-d-aspartate receptor (NMDA-R)-mediated oxidative stress has been implicated in blood-brain barrier (BBB) disruption in a variety of neuropathological diseases. Although some interactions between both phenomena have been elucidated, possible influences of reactive oxygen species (ROS) on the NMDA-R itself have so far been neglected. The objective of this study was to examine how the cerebroendothelial NMDA-R is affected by exposure to oxidative stress and to assess possible influences on BBB integrity. RT-PCR confirmed several NMDA-R subunits (NR1, NR2B-D) expressed in the bEnd3 cell line (murine cerebrovascular endothelial cells). NR1 protein expression after exposure to ROS was ob…
Dendritic Ih selectively blocks temporal summation of unsynchronized distal inputs in CA1 pyramidal neurons.
2004
The active dendritic conductances shape the input-output properties of many principal neurons in different brain regions, and the various ways in which they regulate neuronal excitability need to be investigated to better understand their functional consequences. Using a realistic model of a hippocampal CA1 pyramidal neuron, we show a major role for the hyperpolarization-activated current, I-h, in regulating the spike probability of a neuron when independent synaptic inputs are activated with different degrees of synchronization and at different distances from the soma. The results allowed us to make the experimentally testable prediction that the I-h in these neurons is needed to reduce ne…
The effects of glutamate receptor antagonists on cerebellar granule cell survival and development.
2007
N-Methyl-d-aspartate (NMDA) receptor stimulation promotes neuronal survival and differentiation under both in vitro and in vivo conditions. We studied the effects of various NMDA receptor antagonists acting at different NMDA receptor binding sites and non-NMDA receptor antagonists on the development and survival of cerebellar granule cell (CGC) culture. Only three of the drugs tested induced neurotoxicity-MK-801 (non-competitive NMDA channel blocking antagonist), ifenprodil (an antagonist of the NR2B site and polyamine site of the NMDA receptor) and L-701.324 (full antagonist at glycine site), while CGP-37849 (a competitive NMDA antagonist), (+)-HA-966 (a partial agonist of the glycine site…
Aprites ekonomika sabiedriskajā ēdināšanā kā pelnītspēju veicinošais faktors.
2022
Lai nodrošinātu sabiedriskās ēdināšanas uzņēmumu ilgtspējīgu izaugsmi, resursu izmantošanai jākļūst gudrākai un ilgtspējīgākai. Ir skaidrs, ka agrākais ekonomikas izaugsmes lineārais modelis vairs neder mūsdienu globalizētās pasaules sabiedrības vajadzībām. Nav iespējams izveidot nākotni, ņemot par pamatu modeli „paņemt, uztaisīt, izmest”. Daudzi dabas resursi ir ierobežoti, un ir jāatrod veids, kā tos izmantot no vides un ekonomikas viedokļa ilgtspējīgi. Izmantot esošos resursus labākajā iespējamajā veidā ir arī uzņēmumu ekonomiskajās interesēs. Maģistra darba mērķis ir izpētīt aprites ekonomikas lomu sabiedriskās ēdināšanas uzņēmumos, sabiedrības informētības līmeni, paradumus un viedokli…
Powstanie listopadowe we "Wspomnieniach" Nadieżdy Golicyny
2016
The article presents Nadezhda Ivanovna Golitsyna’s (1796—1868) memories of the Polish November Uprising. Golitsyna was a wife of a count Alexander Fyodorovitch Golitsyn (1796—1864), who was a high‑ranking Tsarist official. They lived in Warsaw, where the husband of the author of the Memoirs worked in the office of the Grand Prince Konstantin. Golitsyn was, most probably, a secret agent of the Third Division. After the outbreak of the November Uprising the Golitsynys, together with prince Konstantin’s troops, left Warsaw. The Poles’ struggle for independence is presented in Golitsyna’s Memoirs as a sudden and unexpected rebellion organised by a group of students against the Russian ruler. Go…
Nanostructure, composition and mechanisms of bivalve shell growth
2008
Abstract Freshwater and marine cultured pearls form via identical processes to the shells of bivalves and can therefore serve as models for the biomineralization of bivalve shells in general. Their nanostructure consists of membrane-coated granules (vesicles) which contain amorphous calcium carbonate (ACC) at the beginning of the biomineralization sequence, preceding the crystallization of aragonite and vaterite. In contrast to the commonly accepted view, crystallization of ACC occurs rapidly and within the granular nano-compartments mediated by organic molecules much earlier than platelet formation. The interlamellar organic sheets in nacre that form the platelet structure of nacre themsel…
First principles modeling of 3d-metal doped three-layer fluorite-structured TiO2 (4,4) nanotube to be used for photocatalytic hydrogen production
2017
This study has been supported by the EC ERA.Net RUS Plus project No. 237 WATERSPLIT, Russian Basic Research Foundation No. 16-53-76019, and additionally by the IMIS2 Program (Latvia). The authors are also indebted to R. A. Evarestov and O. Lisovski for stimulating discussions as well as to A. Chesnokov for technical assistance.
Chemical Mimicry: Hierarchical 1D TiO2@ZrO2 Core−Shell Structures Reminiscent of Sponge Spicules by the Synergistic Effect of Silicatein-α and Silint…
2011
In nature, mineralization of hard tissues occurs due to the synergistic effect of components present in the organic matrix of these tissues, with templating and catalytic effects. In Suberites domuncula, a well-studied example of the class of demosponges, silica formation is mediated and templated by an axial proteinaceous filament with silicatein-α, one of the main components. But so far, the effect of other organic constituents from the proteinaceous filament on the catalytic effect of silicatein-α has not been studied in detail. Here we describe the synthesis of core-shell TiO(2)@SiO(2) and TiO(2)@ZrO(2) nanofibers via grafting of silicatein-α onto a TiO(2) nanowire backbone followed by …