Search results for "nap"
showing 10 items of 2226 documents
Coincident glutamatergic depolarizations enhance GABAA receptor-dependent Cl- influx in mature and suppress Cl- efflux in immature neurons.
2021
The impact of GABAergic transmission on neuronal excitability depends on the Cl--gradient across membranes. However, the Cl--fluxes through GABAA receptors alter the intracellular Cl- concentration ([Cl-]i) and in turn attenuate GABAergic responses, a process termed ionic plasticity. Recently it has been shown that coincident glutamatergic inputs significantly affect ionic plasticity. Yet how the [Cl-]i changes depend on the properties of glutamatergic inputs and their spatiotemporal relation to GABAergic stimuli is unknown. To investigate this issue, we used compartmental biophysical models of Cl- dynamics simulating either a simple ball-and-stick topology or a reconstructed CA3 neuron. Th…
Principal component analysis on molecular descriptors as an alternative point of view in the search of new Hsp90 inhibitors
2009
Inhibiting a protein that regulates multiple signal transduction pathways in cancer cells is an attractive goal for cancer therapy. Heat shock protein 90 (Hsp90) is one of the most promising molecular targets for such an approach. In fact, Hsp90 is a ubiquitous molecular chaperone protein that is involved in folding, activating and assembling of many key mediators of signal transduction, cellular growth, differentiation, stress-response and apoptothic pathways. With the aim to analyze which molecular descriptors have the higher importance in the binding interactions of these classes, we first performed molecular docking experiments on the 187 Hsp90 inhibitors included in the BindingDB, a pu…
Ēnas noņemšana no attēla
2018
Ēna digitālajā attēlā nereti ir uzskatāma par vizuālu traucēkli objektu noteikšanai un meklēšanai, jo ēnas tumšo reģionu dēļ ir apgrūtināta objektu formu noteikšana informācijas zudumu dēļ. Datba mērķis ir izpētīt āra apgaismojuma apstākļos uzņemta fotoattēla automātiskās ēnas noņemšanas iespējas. Tā sasniegšanai tika izvirzīti zemāk uzskaitītie uzdevumi: 1. apkopot informāciju par ēnu āra apgaismojuma apstākļos; 2. apzināt ēnas noņemšanas no attēla problēmapgabalu, tā izpētes stadijas un risināšanas tendences; 3. analizēt jau izstrādāto manuālo grafisko apstrādes rīku izmantošanas iespējas un uz piemēriem praktiski veikt ēnu noņemšanu; 4. pielāgot un apmācīt ģeneratīvos mašīnapmācības mode…
Nigral influence on focal epilepsy.
1990
The substantia nigra (SN) has been proposed as a structure involved in epileptiform phenomena. Previous investigations demonstrated that SN is able to elicit hippocampal rhythmic slow activity (RSA) as well as to inhibit hippocampal interictal spikes induced by parenteral administration of penicillin. The present series of experiments was carried out in order to characterize the action of SN on a focal model of hippocampal epilepsy. Experiments were performed on encephale isole cats in which steady epileptiform activity was induced by locally applied penicillin. Electrical stimulation of SN pars reticulata (pr) caused a statistically significant decrease of hippocampal spike frequency and a…
Paradigms as triggers of semantic change: Demonstrative adverbs in Catalan and Spanish
2015
This paper sets out to analyse the development of demonstrative adverbs of place in Catalan and Spanish. The main questions dealt with in this study are the following: (i) why two-term and three-term deictic systems often display a certain lack of stability so that diachronically two-term systems sometimes become three-term (as in old Catalan and Spanish) or, the other way round, three-term systems become two-term (like in late Latin and in Catalan during the modern era); (ii) if the most normal and expected development is for deictic systems to take on anaphoric values, why in the case of the adverb aquí ('near the speaker and/or addressee') in Catalan and the adverb ahí ('near the address…
Role of nitric oxide and nitric oxide synthases in experimental models of denervation and reinnervation.
2001
Nitric oxide (NO) is a short-living free molecule synthesized by three different isoforms of nitric oxide synthases (NOS)—neuronal NOS, endothelial NOS, and inducible NOS—associated with neuromuscular transmission, muscle contractility, mitochondrial respiration, and carbohydrate metabolism in skeletal muscle. Neuronal NOS is constitutively expressed at the muscle fiber sarcolemma linked to the dystrophin-glycoprotein complex and concentrated at the neuromuscular endplate. There is increasing evidence that altered expression of neuronal NOS plays a role in muscle fiber damage in neuromuscular diseases such as dystrophinopathies and denervating disorders. Although there have been some previo…
Senās Ēģiptes kultūras mantojuma atspoguļojums D.V. Denona un C.L.F. Pankūka izdotajos “Ēģiptes aprakstos”
2019
Maģistra darba “Senās Ēģiptes kultūras mantojuma atspoguļojums D.V.Denona un C.L.F . Pankūka izdotajos “Ēģiptes aprakstos”” mērķis ir izpētīt pēc kādiem principiem tika dokumentēts Ēģiptes kultūras mantojums. Galvenie dokumentācijas principi bija pēc iespējas precīzāka seno kultūras pieminekļu un senlietu attēlošana, to daudzveidības parādīšana, pievēršot uzmanību detaļām. Nozīmīgākie seno laiku pārvaldes un reliģiskie centri tika attēloti izvērstāk nekā mazāk zināmas vietas. Tādējādi tika parādīts, ka Ēģiptes teritorijā pirms arābu kultūras ienākšanas ir bijusi tikpat augsti attīstīta civilizācija kā senā Grieķija un Roma. N. Bonaparts atbalstot Ēģiptes apraksta izdošanu veidoja apgaismota…
Exploiting 1,4-naphthoquinone and 3-iodo-1,4-naphthoquinone motifs as anion binding sites by hydrogen or halogen-bonding interactions
2019
We describe here the utilization of 1,4-naphthoquinone and 3-iodo-1,4-naphthoquinone motifs as new anion binding sites by hydrogen- or halogen-bonding interactions, respectively. These binding sites have been integrated in bidentate ester based receptors. Emission experiments reveal that both receptors selectively recognize sulfate anions, which induced a remarkable increase of a new emission band attributed to the formation of π-stacking interactions between two 1,4-naphthoquinone units. Absorption spectroscopy and mass spectrometry indicate the disruption of the ester group of the 1,4-naphthoquinone based receptor in the presence of HP2O73−, H2PO4−, F−, AcO− and C6H5CO2− and in the haloge…
DNA binding, nuclease activity, DNA photocleavage and cytotoxic properties of Cu(II) complexes of N-substituted sulfonamides.
2013
Abstract Ternary copper(II) complexes [Cu(NST)2(phen)] (1) and [Cu(NST)2(NH3)2]·H2O (2) [HNST = N-(4,5-dimethylthiazol-2-yl)naphthalene-1-sulfonamide] were prepared and characterized by physico-chemical techniques. Both 1 and 2 were structurally characterized by X-ray crystallography. The crystal structures show the presence of a distorted square planar CuN4 geometry in which the deprotonated sulfonamide, acting as monodentate ligand, binds to the metal ion through the thiazole N atom. Both complexes present intermolecular π–π stacking interactions between phenanthroline rings (compound 1) and between naphthalene rings (compound 2). The interaction of the complexes with CT DNA was studied b…
Fluorimetric determination of 1-naphthol and mixtures of carbaryl and 1-naphthol in micellar media
1990
The interaction of 1-naphthol with different types of anionic, cationic and non-ionic surfactants has been studied spectrofluorimetrically in order to obtain a sensitivity enhancement in the determination of this compound. At neutral pH, cetyl trimethyl ammonium bromide (CTAB) provides a 2-fold sensitivity enhancement of 1-naphthol and exhibits a weak interaction with carbaryl. In strong alkaline medium carbaryl is hydrolyzed to 1-naphthol and in the presence of CTAB micells, a 5-fold sensitivity enhancement and a limit of detection of 0.2 μg·ml−1 with a 101±3% percentage of recovery is obtained. These facts permit the development of an accurate method for the fluorimetric analysis of 1-nap…