Search results for "Smut"
showing 10 items of 493 documents
Inverse-voltammetric determination of bismuth in biomaterials with computer assisted peak evaluation. part 3. Bismuth determination in wine, grapes a…
1989
The ultra trace element bismuth is regulary found in wine on an average of about 0.1 ppb. Very low bismuth contents were also determined in soil and different biomaterials. In spite of those very low quantities even speciation experiments show results, so far that about 90% of the bismuth in the grapes is water-soluble, resumably as saccharic acids. For detecting such low quantities a very sensitive method of differential pulse anodic stripping voltammetry was developped. The speciation experiments were carried out by fractional extraction.
Flavonols and flavan-3-ols as modulators of xanthine oxidase and manganese superoxide dismutase activity.
2014
Experiments were performed to assess the dose-dependent effects of quercetin, kaempferol, (+) catechin, and (-) epicatechin on superoxide radical production through the modulation of manganese superoxide dismutase and xanthine oxidase activities. The experiments were carried out at flavanoid concentrations ranging from 1 µM to 100 µM. This investigation highlighted that flavonols induced opposite effects on superoxide radical production at different doses, i.e. pro-oxidant at the highest concentration (100 µM) and anti-oxidant at the lowest concentration (1 µM). Similar behaviors were observed for xanthine oxidase with flavan-3ols. The diastereoisomer (the catechin) acted as a stronger radi…
Vascular oxidative stress, nitric oxide and atherosclerosis.
2014
In the vascular wall, reactive oxygen species (ROS) are produced by several enzyme systems including NADPH oxidase, xanthine oxidase, uncoupled endothelial nitric oxide synthase (eNOS) and the mitochondrial electron transport chain. On the other hand, the vasculature is protected by antioxidant enzyme systems, including superoxide dismutases, catalase, glutathione peroxidases and paraoxonases, which detoxify ROS. Cardiovascular risk factors such as hypercholesterolemia, hypertension, and diabetes mellitus enhance ROS generation, resulting in oxidative stress. This leads to oxidative modification of lipoproteins and phospholipids, mechanisms that contribute to atherogenesis. In addition, oxi…
Recombinant hydroperoxide lyase for the production of aroma compounds: Effect of substrate on the yeast Yarrowia lipolytica
2008
International audience; The aim of this study was to investigate the action mechanism of linoleic acid hydroperoxides (HPOD), which are the major substrates of hydroperoxide lyase for the production of flavour compounds, on the yeast Yarrowia lipolytica by evaluating their effect on the oxidative state of the cells. The total antioxidant capacity (TAC) and the activity of the main antioxidant enzymes, such as glutathione reductase, glutathione peroxidase and superoxide dismutase, of cells treated with HPOD were studied. The potential role of intracellular glutathione, including reduced glutathione (GSH) and oxidized glutathione (GSSG), in conferring HPOD resistance was also been examined. T…
Nanostrukturētu bismuta halkogenīdu plānu kārtiņu sintēze un to stabilitātes noteikšana dažādās vidēs
2018
Topoloģiskie izolatori (TI) ir materiāli, kuru virsma ir elektriski vadoša, bet to tilpums ir elektriski izolējošs. Lielākajai daļai topoloģisko izolatoru ir teicamas termoelektriskās īpašības. Tomēr, neskatoties uz pēdējo gadu straujo attīstību topoloģisko izolatoru jomā, TI pielietojumi praktiskās ierīcēs ir salīdzinoši jauna un neizpētīta nozare. Šajā darbā, izmantojot bezkatalizatora fizikālo tvaiku iztvaicēšanu, tika sintezētas planāras, neplanāras un ultraplānas bismuta (III) selenīda un bismuta (III) telurīda plānās kārtiņas. Tika izstrādāta jauna metode ultraplānu (<15 nm) plāno kārtiņu sintēzei. Iegūtās nanostrukturētas plānās kārtiņas, kurām piemīt gan topoloģisko izolatoru, gan i…
Complejos de ligandos azamacrocíclicos como miméticos de enzimas con actividad antioxidante
2019
The imbalance between the generation and clearance of reactive oxygen species (ROS) causes oxidative stress, which is related to a variety of health issues that include neurodegenerative disorders such as Parkinson’s and Alzheimer’s disease. In order to remove ROS, living organisms have developed a battery of protective enzymes, such as superoxide dismutases (SODs). Although SOD enzymes have shown therapeutic efficacy, their use has severe drawbacks such as the absence of oral activity, immunogenicity, short half-life and low cell permeability. Therefore, low-molecular weight mimetics may offer better outcomes regarding properties such as lack of antigenicity, good tissue penetrance, high s…
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.
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…
Chamazulene-Rich Artemisia arborescens Essential Oils Affect the Cell Growth of Human Melanoma Cells
2020
Artemisia arborescens is an aromatic shrub whose essential oils are considered a potential source of molecules with industrial and pharmaceutical interest. The chemical profile of A. arborescens essential oils (EOs) was shown to be quite variable and various chemotypes have been identified. In this study, we compared the EOs composition of A. arborescens leaves and flowers collected from four different locations in Sicily. The EOs were assayed for their antiproliferative activity against A375 human malignant melanoma cells, also testing cell viability and cell membrane integrity. The evaluation of DNA fragmentation and caspase-3 activity assay was employed for the detection of apoptosis. Th…
Homo- and Heterobinuclear Cu2+ and Zn2+ Complexes of Ditopic Aza Scorpiand Ligands as Superoxide Dismutase Mimics
2017
Two polytopic aza-scorpiand-like ligands, 6-[7-(diaminoethyl)-3,7-diazaheptyl]-3,6,9-triaza-1-(2,6-pyridina)cyclodecaphane (L1) and 6-[6′-[3,6,9-triaza-1-(2,6-pyridina)cyclodecaphan-6-yl]-3-azahexyl]-3,6,9-triaza-1-(2,6-pyridina)cyclodecaphane (L2), have been synthesized. The acid–base behavior and Cu2+, Zn2+, and Cu2+/Zn2+ mixed coordination have been analyzed by potentiometry, cyclic voltammetry, and UV–vis spectroscopy. The resolution of the crystal structures of [Cu2L2Cl2](ClO4)2·1.67H2O (1), [Cu2HL2Br2](ClO4)3·1.5H2O (2), and [CuZnL2Cl2](ClO4)2·1.64H2O (3) shows, in agreement with the solution data, the formation of homobinuclear Cu2+/Cu2+ and heterobinuclear Cu2+/Zn2+ complexes. The m…