Search results for "SELE"
showing 10 items of 4721 documents
Chiral hemicucurbit[8]uril as an anion receptor: selectivity to size, shape and charge distribution
2017
A novel eight-membered macrocycle of the hemicucurbit[n]uril family, chiral (all-R)-cyclohexanohemicucurbit[8]uril (cycHC[8]) binds anions in a purely protic solvent with remarkable selectivity. The cycHC[8] portals open and close to fully encapsulate anions in a 1 : 1 ratio, resembling a molecular Pac-Man™. Comprehensive gas, solution and solid phase studies prove that the binding is governed by the size, shape and charge distribution of the bound anion. Gas phase studies show an order of SbF6− ≈ PF6− > ReO4− > ClO4− > SCN− > BF4− > HSO4− > CF3SO3− for anion complexation strength. An extensive crystallographic study reveals the preferred orientations of the anions within the octahedral cav…
Bi2Se3 Nanostructured Thin Films as Perspective Anodes for Aqueous Rechargeable Lithium-Ion Batteries
2022
This research was funded by the European Regional Development Fund Project (ERDF) No. 1.1.1.1/19/A/139. Y.R. acknowledges the support of post-doctoral ERDF project No. 1.1.1.2/VIAA/4/20/694. V.L. also acknowledges the support of “Strengthening of the capacity of doctoral studies at the University of Latvia within the framework of the new doctoral model”, identification No. 8.2.2.0/20/I/006. A.S. acknowledges the support from the Institute of Solid State Physics, University of Latvia, which, as the Center of Excellence, has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART2.
Simulating multilevel dynamics of antimicrobial resistance in a membrane computing model
2019
Membrane computing is a bio-inspired computing paradigm whose devices are the so-called membrane systems or P systems. The P system designed in this work reproduces complex biological landscapes in the computer world. It uses nested “membrane-surrounded entities” able to divide, propagate, and die; to be transferred into other membranes; to exchange informative material according to flexible rules; and to mutate and be selected by external agents. This allows the exploration of hierarchical interactive dynamics resulting from the probabilistic interaction of genes (phenotypes), clones, species, hosts, environments, and antibiotic challenges. Our model facilitates analysis of several aspects…
Ar bismuta un atntimona halkogenīdu un CNT heterostruktūrām modificētu polimēru nanokompozītu izgatavošana, raksturošana un pielietojums termoelektri…
2019
Termoelektriski nanokompozīti, kas modificēti ar oglekļa nanocaurulītēm (CNT), ir pēdējos gados interesi izraisījis pētījumu lauks, galvenokārt saistībā ar to potenciālo pielietojumu elastīgu elektroierīču, tai skaitā termoelektrisko ierīču, ražošanā. Tomēr, salīdzinot neorganiskajiem termoelektriskajiem materiāliem, uz polimēriem bāzētas termoelektriskās ierīces ievērojami atpaliek termoelektriskajā efektivitātē. Šajā darbā uz polimēru bāzes veidoti nanokompozīti tika modificēti ar CNT, uz kurām uzsintezēts Bi2Se3 un Sb2Te3, plaši pielietoti n- un p-tipa pusvadītāji, kas piesaistījuši pētnieku uzmanību ar izcilām termoelektriskajām un topoloģisko dielektriķu īpašībām. Bi2Se3 un Sb2Te3 nano…
Selenofēnkumarīnu un selenofēnhinolonu salīdzinošā ietekme uz HepG2 šūnu fermentatīvo antioksidatīvo sistēmu
2015
Latvijas Organiskās sintēzes institūtā izstrādātas metodes jaunu selenofēn[3,2-c] un [2,3-c]kumarīnu un selenofēn[3,2-c] un [2,3-c]hinolonu sintēzei, kuriem pierādīts antiproliferatīvais efekts in vitro. Darbā tika noteikts savienojumu inhibējošais efekts uz trim hepatomas HepG2 šūnu galvenajiem antioksidatīvajiem fermentiem (GPx, TrxR, SOD) ar mērķi noskaidrot savienojumu antiproliferatīvā efekta darbības mehānismus. Pētījumā konstatēts, ka visi savienojumi ir efektīvi GPx inhibitori. TrxR aktivitāti inhibē selenofēnhinoloni un [3,2-c] aizvietotie selenofēnkumarīni, savukārt SOD aktivitāti ietekmē tikai divi no savienojumiem. Kopumā noteikts, ka selenofēnhinoloni ir aktīvāki antioksidatīvo…
1-methil-3H-pyrazolo[1-2-a]benzo[1-2-3-4]tetrazin-3-ones, design synthesis and biological activity of new antitumoral agents
2005
1-Methylpyrazolo[1,2-a]benzo[1,2,3,4]tetrazin-3-ones 4, synthesized in good to excellent yields, were designed as novel alkylating agents because of their peculiar chemical behavior. All derivatives showed antiproliferative activity against more than 50 types of tumor cell lines with GI50 reaching sub-micromolar values. SAR studies revealed that the presence of a chlorine atom is well-tolerated in both positions 8 and 9, whereas in the case of the methyl group, switching from the 8 to the 9 position gives rise to the most active compound of the series, 4g, either for the number of cell lines inhibited and for selectivity against leukaemia and renal cancer subpanels. COMPARE and 3D-MIND comp…
Reduction in site fidelity with smaller spatial scale may suggest scale-dependent information use
2014
Animals change the strategy that they use to select breeding sites at the spatial scales of habitat, patch, and microhabitat. In this regard, breeding site fidelity is expected to vary according to environmental predictability, which, in turn, is expected to differ between each spatial scale. However, whether or not animals change their degree of site fidelity at different spatial scales remains unclear. We captured and released males of the terrestrial frog Pseudophryne bibronii into alternative patches within a breeding habitat and determined the extent to which site fidelity influenced individual nest-site choice. We found that males tended to return to their original patch rather than r…
Le score de propension : un guide méthodologique pour les recherches expérimentales et quasi expérimentales en éducation
2016
La méthode du score de propension devient de plus en plus populaire pour estimer les effets causaux d’un programme d’intervention. Si les applications empiriques de cette méthode sont encore rares dans les recherches en éducation, des exemples de son utilisation se trouvent aisément dans d’autres disciplines. Cependant, sa mise en place soulève plusieurs questions. L’objectif de cet article est de fournir des éléments de réponses guidant le chercheur et l’évaluateur du domaine de l’éducation pour l’estimation et l’utilisation du score de propension. Les différentes étapes de son application sont présentées pas à pas : évaluation du biais de sélection, construction du score de propension et …