Aldrithiol-2 as a new derivatization agent for double bond localization in unsaturated compounds by mass spectrometry
Strmeň, Timotej; Cvačka, Josef
2019 - anglický A new method for localizing double bonds in lipids using derivatization with 2,2'-clipyridyl disulfide (Aldrithio-2) and electrospray ionization mass spectrometry (EST-MS) is presented. The derivatization introduces a permanent charge to the molecules. When collisionally activated, the derivatives provide diagnostic peaks useful for establishing the position of the original double bond. Since permanent charge of the derivative significantly increases the detectability of analytes, the method works well also for of very low polarity like hydrocarbons. Klíčová slova: aldrithiol-2; double bond; electrospray; lipids; mass spectrometry Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR. Aldrithiol-2 as a new derivatization agent for double bond localization in unsaturated compounds by mass spectrometry

A new method for localizing double bonds in lipids using derivatization with 2,2'-clipyridyl disulfide (Aldrithio-2) and electrospray ionization mass spectrometry (EST-MS) is presented. The ...

Strmeň, Timotej; Cvačka, Josef
Ústav organické chemie a biochemie, 2019

Mechanism of the Water Clusters Formation in the Organic Phase in the Presence of Hydrated Ions
Holub, Karel; Samec, Zdeněk; Mareček, Vladimír
2019 - anglický A two-electrode cell comprising a liquid/liquid interface is used to study the water clusters formation in the organic solvent phase following the extraction of tetraalkylammonium chloride (TAACl) from the aqueous phase. The change in the concentration of the common TAA+ ion on the aqueous side of the interface is monitored by the open circuit potential measurements. It is shown that the amount of TAACl extracted into the organic phase exceeds considerably the limit determined by the concentration of Cl- in the organic phase at a given interfacial potential difference and the electroneutrality condition. A mechanism is proposed including an accumulation of the excess TAACl in the water clusters formed from the hydration shell of the Cl- ions, water already dissolved in the organic phase, and additional water extracted from the aqueous phase. At higher concentration of TAACl in the aqueous phase this process leads to the formation of emulsion in the organic phase. Klíčová slova: liquid/liquid interface; water co-extraction dynemics; emulsification Plné texty jsou dostupné na vyžádání prostřednictvím repozitáře Akademie věd. Mechanism of the Water Clusters Formation in the Organic Phase in the Presence of Hydrated Ions

A two-electrode cell comprising a liquid/liquid interface is used to study the water clusters formation in the organic solvent phase following the extraction of tetraalkylammonium chloride (TAACl) ...

Holub, Karel; Samec, Zdeněk; Mareček, Vladimír
Ústav fyzikální chemie J. Heyrovského, 2019

Construction and Application of Flow Amperometric Biosensor Based on Enzymatic Reactor for Determination of Choline
Tvorynska, Sofiia; Barek, J.; Josypčuk, Bohdan
2019 - anglický In this contribution, a novel fast, simple and stable biosensor with the enzymatic reactor based on choline oxidase (ChOx) was developed and applied for the determination of choline using flow injection analysis with amperometric detection. The preparation of the reactor is based on the covalent immobilization of ChOx with glutaraldehyde to mesoporous silica powder (SBA-15) previously covered by NH2-groups. The experimental parameters affecting the sensitivity and stability of the biosensor were optimized. The proposed biosensor with the newly developed ChOx-based reactor possesses good repeatability, reproducibility, long-term stability, and reusability. It was successfully applied for the determination of choline in commercial pharmaceuticals. Klíčová slova: choline; choline oxidase; Flow analysis; enzymatic reactor Plné texty jsou dostupné na vyžádání prostřednictvím repozitáře Akademie věd. Construction and Application of Flow Amperometric Biosensor Based on Enzymatic Reactor for Determination of Choline

In this contribution, a novel fast, simple and stable biosensor with the enzymatic reactor based on choline oxidase (ChOx) was developed and applied for the determination of choline using flow ...

Tvorynska, Sofiia; Barek, J.; Josypčuk, Bohdan
Ústav fyzikální chemie J. Heyrovského, 2019

Interactive effects of elevated CO2 concentration, drought and nitrogen nutrition on malting quality of spring barley
Simor, J.; Klem, Karel; Psota, V.
2019 - anglický Elevated CO2 concentration [EC] generally leads to increased rates of photosynthesis, increased formation of assimilates and finally to storing them in the grain. Increased storage of starch in the grain, however, leads to an unbalanced proportion to the proteins, and their relative content decreases. This is particularly apparent in the conditions of nitrogen deficiency. The interactive effects of EC, nitrogen nutrition and reduced water availability are, however, not yet sufficiently understood. Within the manipulation experiment in open top chambers (Domaninek near Bystrice nad Pernstejnem) that allow simulation of EC (expected by the end of this century 700 ppm) and drought, the effect of these interactions on protein content, and other quality parameters of spring barley grain was studied. EC reduced grain protein content, increased extract, Kolbach index and also summary Malting quality index. Such effect was more pronounced under higher nitrogen dose, which generally worsened malting quality parameters. Reduced water availability slightly enhanced all malting quality parameters and also showed slight synergistic effect to EC. No clear interactive effects on malting quality were found for nitrogen nutrition and water availability. Klíčová slova: protein-concentration; wheat; impacts; crop; malting barley; greenhouse gases; nitrogen fertilization; reduced water availability Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR. Interactive effects of elevated CO2 concentration, drought and nitrogen nutrition on malting quality of spring barley

Elevated CO2 concentration [EC] generally leads to increased rates of photosynthesis, increased formation of assimilates and finally to storing them in the grain. Increased storage of starch in the ...

Simor, J.; Klem, Karel; Psota, V.
Ústav výzkumu globální změny , 2019

Monitoring of enzymatic enantioselective acetylation of gem-difluorinated alcohols by capillary electrophoresis
Šolínová, Veronika; Pomeisl, Karel; Lamatová, Nikola; Pohl, Radek; Brabcová, Jana; Krečmerová, Marcela; Kašička, Václav
2018 - anglický A new fast and highly efficient capillary electrophoretic (CE) method has been developed for chiral analysis of non-charged gem-difluorinated alcohol (3-(benzyloxy)-1,1-difluoro-propan-2-ol) using sulfobutylether-β-CD as chiral selector. The method was applied for monitoring of enzymatic (lipase mediated) enantioselective acetylation of the above alcohol and for determination of enantiomeric purity of both substrates and products of the enzymatic reaction. Klíčová slova: enantioselective acetylation; difluorinated alcohols; capillary electrophoresis Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR. Monitoring of enzymatic enantioselective acetylation of gem-difluorinated alcohols by capillary electrophoresis

A new fast and highly efficient capillary electrophoretic (CE) method has been developed for chiral analysis of non-charged gem-difluorinated alcohol (3-(benzyloxy)-1,1-difluoro-propan-2-ol) using ...

Šolínová, Veronika; Pomeisl, Karel; Lamatová, Nikola; Pohl, Radek; Brabcová, Jana; Krečmerová, Marcela; Kašička, Václav
Ústav organické chemie a biochemie, 2018

Mesoporous Polymers Created by and Their Application.
Soukupová, Krasimira; Jeřábek, Karel
2018 - anglický Klíčová slova: polymer; mesopores; microsyneresis Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR. Mesoporous Polymers Created by and Their Application.

Soukupová, Krasimira; Jeřábek, Karel
Ústav chemických procesů, 2018

Nanofiber dressing consisting of antisense rna-functionalized nanodiamonds for therapy of non-healing wounds in diabetic individuals
Neuhoferová, Eva; Petráková, V.; Vocetková, K.; Kindermann, Marek; Křivohlavá, Romana; Benson, Veronika
2018 - anglický Non-healing wounds are serious complication in diabetic patients and represent an attractive challenge for development of suitable carrier system possessing constant and localized release of therapeutic biomolecule into the wound without any undesired side effects. Given the fact that these non-healing wounds are result of impaired balance in metalloproteinases synthesized by immune cells residing the wounds, gene therapy offering knock down of such enzymes is of great interest. \nHere we challenged a development of functional and biocompatible wound dressing enabling controlled release of trackable carrier loaded with therapeutic siRNA. Our dressing consists of scaffold from degradable polymer nanofibers enriched with fluorescent nanodiamond particles (FND). We have previously shown the nanodiamond particles are great carriers for antisense RNAs. Their advantages represent high biocompatibility, stable luminescence giving us the possibility to track the carrier system in the wound, and effective release of antisense RNA in the wound. Embedding of nanodiamond-siRNA systems into nanofiber scaffold enables continuous release of siRNA and maintaining the stable siRNA concentration in the wound site resulting in a promotion of wound healing. \nWe developed FND-siRNA complexes specific to MMP-9 that efficiently inhibit the expression of target MMP-9 mRNA. The complexes were embedded into core/shell nanofibers from PVA and PCL, visualized by confocal microscopy, and characterized by electron microscopy. Real-time PCR was used to assess the silencing effect of siRNA that has been delivered to target murine fibroblasts by FND released from nanofiber dressing. Nanofiber system with embedded FNDs was applied on wounds in diabetic animal models to evaluate its suitability regarding short and long term toxicity, efficacy, and handling in vivo. \n Klíčová slova: Electrospun nanofibers; fluorescent nanodiamonds; RNA interference Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR. Nanofiber dressing consisting of antisense rna-functionalized nanodiamonds for therapy of non-healing wounds in diabetic individuals

Non-healing wounds are serious complication in diabetic patients and represent an attractive challenge for development of suitable carrier system possessing constant and localized release of ...

Neuhoferová, Eva; Petráková, V.; Vocetková, K.; Kindermann, Marek; Křivohlavá, Romana; Benson, Veronika
Mikrobiologický ústav, 2018

Electrochemical Measurements in Flow Systems on Silver Amalgam Tubular Detector Combined with Auxiliary Electrode
Josypčuk, Bohdan; Barek, J.; Josypčuk, Oksana
2018 - anglický A new type of tubular detector (TD+AuxE) was proposed, fabricated, tested and compared\nwith a typical silver amalgam tubular detector developed earlier. Non-stop-flow differential\npulse voltammetric anodic stripping method (AS-DPV) and amperometric method in a\nglucose oxidase biosensor arrangement were tested. Both detectors were applied for AS-DPV\nmeasurements in flow systems for the first time. The proposed combination of tubular\ndetector with auxiliary electrode provides a much greater current response than the classic\narrangement with three individual electrodes. All relevant parameters (potentials of\naccumulation or detection, flow rate, analyte concentrations, shielding sleeve length, etc.)\nwere optimized for the developed TD+AuxE. Klíčová slova: Flow analysis; Amperometry; Voltammetry Plné texty jsou dostupné na vyžádání prostřednictvím repozitáře Akademie věd. Electrochemical Measurements in Flow Systems on Silver Amalgam Tubular Detector Combined with Auxiliary Electrode

A new type of tubular detector (TD+AuxE) was proposed, fabricated, tested and compared\nwith a typical silver amalgam tubular detector developed earlier. Non-stop-flow differential\npulse voltammetric ...

Josypčuk, Bohdan; Barek, J.; Josypčuk, Oksana
Ústav fyzikální chemie J. Heyrovského, 2018

Optimization of photochemical vapor generation of molybdenum as a sample introduction for ICP-MS
Šoukal, Jakub; Musil, Stanislav
2018 - anglický Conditions of photochemical vapor generation of molybdenum with ICP-MS detection have been in detail investigated. Klíčová slova: ICP-MS; molybdenum; photochemical vapor generation Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR. Optimization of photochemical vapor generation of molybdenum as a sample introduction for ICP-MS

Conditions of photochemical vapor generation of molybdenum with ICP-MS detection have been in detail investigated.

Šoukal, Jakub; Musil, Stanislav
Ústav analytické chemie, 2018

BETA-GLUCANS: WHAT APPLICATIONS? A GENERAL OVERVIEW
Vannucci, Luca; Mishra, Rajbardhan; Lukáč, Pavol; Tenti, Paolo; Rajsiglová, Lenka; Větvička, Václav; Šíma, Petr
2018 - anglický Glucans are polysaccharides derived from various sources (e.g. mushrooms, algae, yeast, barley). They can target immune receptors, like Dectin-1 expressed on dendritic cells - antigen presenting cells. Otherwise, interest is rising for their use not only for modulation of immunity, but also of cholesterol levels, or as possible vaccine adjuvants, nanocarriers and functional food components. We will shortly review some aspects in human and veterinarian applications. Klíčová slova: Antitumor immune-responses; growth-performance; gastrointestinal-tract Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR. BETA-GLUCANS: WHAT APPLICATIONS? A GENERAL OVERVIEW

Glucans are polysaccharides derived from various sources (e.g. mushrooms, algae, yeast, barley). They can target immune receptors, like Dectin-1 expressed on dendritic cells - antigen presenting ...

Vannucci, Luca; Mishra, Rajbardhan; Lukáč, Pavol; Tenti, Paolo; Rajsiglová, Lenka; Větvička, Václav; Šíma, Petr
Mikrobiologický ústav, 2018