A tudománymetria törvényalkotó „úttörői”

Absztrakt A tudománymetria három sokat emlegetett és idézett törvénye a Bradford-, a Lotka- és a Zipf-törvény. A szerzők röviden bemutatják a három törvény névadójának tudományos pályáját, és hogy hogyan jutottak el a róluk elnevezett törvények megalkotásáig. Vázolják a törvények és névadóik munkásságának utóéletét is. Orv. Hetil., 2016, 157(2), 74–78

A széndioxid katalitikus aktiválásának elméleti tanulmányozása = Theoretical study of the catalytic activation of carbon dioxide

A pályázat keretében folyó kutatások alapvető célja a széndioxid katalitikus átalakítására irányuló reakciók mechamizmusának kvantumkémiai módszerekkel történő leírása volt. A pályázati időszakban közös kísérleti-elméleti tanulmányok során hazai és külföldi kutatócsoportokkal együttműködve a) Részletesen feltártuk mátrix-izolációs kísérletekben tapasztalt M+XCY -> MX+CY típusú reakciók mechanizmusát (X,Y = O,S), b) Jellemeztük újonnan előállított fémhidrid katalizátorok szerkezetét, és értelmeztük a katalizátorok működési mechanizmusát különböző reakciókban, c) Azonosítottuk akrilátok és szerves karbonátok gazdaságos előállítását célzó reakciók elemi lépéseit, illetve a fontosabb intermedierek relatív stabilitását befolyásoló tényezőket. | The primary goal of the present project was to provide mechanistic insight into reactions aiming at catalytic activation of carbon dioxide in terms of quantum chemical calculations. In collaboration with synthetic chemists, we carried out joint experimental-theoretical investigations and succeeded in a) Revealing the mechanism of M+XCY -> MX+CY type reactions (X,Y = O,S) observed in matrix isolation spectroscopic studies, b) Characterizing the structure and reactivity of newly developed metal-hydride catalysts, c) Exploring the elementary steps and key intermediates of reactions of industrial interest, such as acrylate formation and organic carbonate production

Photocatalytic decomposition of methyl formate over TiO2-supported Pt metals

Wehave developed a fully three-dimensional model based on the solutionof the time-dependent Schrödinger equation for studies of polaron mobilityin twisted polymer chains. Variations in ring torsion angles alonga conjugated polymer chain are shown to have a strongeffect on the intrachain charge carrier mobility. An increase inring torsion between two neighboring monomers can cause electron localizationand then result in a transition of the type oftransport from adiabatic polaron drift to nonadiabatic polaron hopping. Inparticular, we show the sensitivity for such a transition inthe case of random variations in the ring torsion anglesalong a poly(phenylene vinylene) chain. The effective energy barrier associatedwith the change in torsion angle also depends on theapplied electric-field strength, and by increasing the field strength atransition back to adiabatic transport can be obtained.Original Publication: Magnus Hultell and Sven Stafström, Impact of ring torsion on the intrachain mobility in conjugated polymers, 2008, Physical Review B. Condensed Matter and Materials Physics, (75), 10, 104304. http://dx.doi.org/10.1103/PhysRevB.75.104304 Copyright: American Physical Society http://www.aps.org/Center of Organic Electronics (COE

Homogén katalitikus reakciók kvantumkémiai tanulmányozása = Quantum Chemical Studies of Homogeneous Catalytic Reactions

A pályázat keretében folytatott kutatási tevékenység alapvető célja homogén katalitikus folyamatok mechamizmusának kvantumkémiai módszerekkel történő feltárása volt. A pályázati időszakban közös kísérleti-elméleti tanulmányok során hazai és külföldi kutatócsoportokkal együttműködve a) jellemeztük több, a széndioxid kémiai átalakításában fontos szerepet játszó átmenetifém-komplex szerkezetét és reaktivitását; b) részletesen feltártuk egy karbamid alapú bifunkciós organokatalizátor aszimmetrikus Michael-addíciós reakciókban kifejtett katalitikus hatását; c) új mechanisztikus modellt javasoltunk az úgynevezett ""frusztrált Lewis párok"" különleges reaktivitásának értelmezésére. Eredményeink hozzájárultak új katalizátorok tervezéséhez. | The primary goal of the present project was to provide mechanistic insight into homogeneous catalytic reactions using quantum chemical calculations. In collaboration with synthetic chemists, we carried out joint experimental-theoretical investigations and succeeded in a) characterizing the structure and reactivity of a number of transition metal complexes relevant to the chemical utilization of carbon dioxide; b) exploring the catalytic effect of thiourea-based bifunctional organocatalysts in asymmetric Michael addition reactions; c) providing a new mechanistic model that accounst for the unique reactivity of ""frustrated Lewis pairs"" towards small molecules. Our results made considerable impact on the development of new catalysts

Palaeofluid evolution in a fractured basalt hosted reservoir in the Üllés-Ruzsa-Bordány area, southern sector of the Pannonian Basin

Extensive Miocene volcanic activity produced basaltic and pyroclastic successions, which were penetrated by many wells in the area of Üllés-Ruzsa-Bordány, in the western and central part of the Great Hungarian Plain. The Kecel Basalt comprises primary porosity from a high proportion of vesicles and significant secondary fracture porosity, as well. Due to the significant fracture porosity, some depth intervals show good reservoir characteristics, although the fractures crosscutting the rock body are partly or entirely cemented by various minerals. Based on the textural and mineralogical features, four distinct vein types can be distinguished, named after their volumetrically most abundant cement phases, i.e. potassium-feldspar (Kfp-), calcite (Cal-), laumontite (Lmt-) and analcime (Anl-) types. This study focuses on probably the youngest of these vein types, the Anl-type. Based on the study of veins and mineral sequences, the direction of temperature changes cannot be given unequivocally for every stage of cementation, but crystallization of the Anl-type veins might have occurred at lower temperatures than the formation of the Lmt-type veins. Fluid inclusion studies suggest that hydrocarbon migration and accumulation took place after cementation of the first three vein types (Kfp-, Cal- and Lmt-types). In the newly opened fracture system, two types of hydrocarbon (HC1 and HC2)-bearing fluid inclusion assemblages were captured during precipitation of analcime and later zeolites. This refers to two stages of hydrocarbon migration in the fracture system. Observations of the fluorescence colours and low temperature behaviours of the hydrocarbon-bearing inclusions, the earlier HC1 petroleum-inclusions captured heavier (presumably less mature oils), while the later ones (HC2) lighter (presumably more mature) oils. The HC2 petroleum seems to be very similar to the crude oil sampled in a well in the area based on their fluorescence parameters.</p

GWAS meta-analysis of over 29,000 people with epilepsy identifies 26 risk loci and subtype-specific genetic architecture

Epilepsy is a highly heritable disorder affecting over 50 million people worldwide, of which about one-third are resistant to current treatments. Here we report a multi-ancestry genome-wide association study including 29,944 cases, stratified into three broad categories and seven subtypes of epilepsy, and 52,538 controls. We identify 26 genome-wide significant loci, 19 of which are specific to genetic generalized epilepsy (GGE). We implicate 29 likely causal genes underlying these 26 loci. SNP-based heritability analyses show that common variants explain between 39.6% and 90% of genetic risk for GGE and its subtypes. Subtype analysis revealed markedly different genetic architectures between focal and generalized epilepsies. Gene-set analyses of GGE signals implicate synaptic processes in both excitatory and inhibitory neurons in the brain. Prioritized candidate genes overlap with monogenic epilepsy genes and with targets of current antiseizure medications. Finally, we leverage our results to identify alternate drugs with predicted efficacy if repurposed for epilepsy treatment