Search results for "Dyes"

Fluorescence-based assays for screening nine cytochrome P450 (P450) activities in intact cells expressing individual human P450 enzymes.

2004

In this study we describe a battery of fluorescence assays for rapid measurement in intact cells of the activity of nine cytochromes P450 (P450s) involved in drug metabolism. The assays are based on the direct incubation of monolayers of cells expressing individual P450 enzymes with a fluorogenic substrate followed by fluorimetric quantification of the product formed and released into incubation medium. For each individual P450 activity, different fluorescence probes were examined, and the one showing the best properties (highest metabolic rates, lowest background fluorescence) was selected: 3-cyano-7-ethoxycoumarin for CYP1A2 and CYP2C19, coumarin for CYP2A6, 7-ethoxy-4-trifluoromethylcoum…

Hydrolytic action of phospholipase A2 in monolayers in the phase transition region: direct observation of enzyme domain formation using fluorescence …

1990

Phospholipase A2, a ubiquitous lipolytic enzyme highly active in the hydrolysis of organized phospholipid substrates, has been characterized optically in its action against a variety of phospholipid monolayers using fluorescence microscopy. By labeling the enzyme with a fluorescent marker and introducing it into the subphase of a Langmuir film balance, the hydrolysis of lipid monolayers in their liquid-solid phase transition region could be directly observed with the assistance of an epifluorescence microscope. Visual observation of hydrolysis of different phospholipid monolayers in the phase transition region in real-time could differentiate various mechanisms of hydrolytic action against …

Glass-Forming Nonsymmetric DWKdyes with 5,5,5-Triphenylpentyl and Piparazine Moieties for Lightamplification Studies

2018

This work has been supported by the European Regional Development Fund within the Activity 1.1.1.2 “Post-doctoral Research Aid” of the Specific Aid Objective 1.1.1 “To increase the research and innovative capacity of scientific institutions of Latvia and the ability to attract external financing, investing in human resources and infrastructure” of the Operational Programme “Growth and Employment” (No. 1.1.1.2/VIAA/1/16/035). Financial support provided by A. Riekstins SIA “Mikrotīkls” donation, administered by the University of Latvia is greatly appreciated. There are no conflicts of interest to declare.

Subpicosecond transient signal spectroscopy of Prodan in dimethylformamide solution.

2008

We report a pump-probe experiment revealing the temporal evolution of subpicosecond evolution of Prodan's excited-state absorption in dimethylformamide. Also, we present calculation of the first spectral moment of this spectral band and estimation of different relaxation components on the subpicosecond time scale.

Biomimetic model of a plant photosystem consisting of a recombinant light-harvesting complex and a terrylene dye.

2002

Modification of Plasma Membrane Organization in Tobacco Cells Elicited by Cryptogein

2014

Abstract Lipid mixtures within artificial membranes undergo a separation into liquid-disordered and liquid-ordered phases. However, the existence of this segregation into microscopic liquid-ordered phases has been difficult to prove in living cells, and the precise organization of the plasma membrane into such phases has not been elucidated in plant cells. We developed a multispectral confocal microscopy approach to generate ratiometric images of the plasma membrane surface of Bright Yellow 2 tobacco (Nicotiana tabacum) suspension cells labeled with an environment sensitive fluorescent probe. This allowed the in vivo characterization of the global level of order of this membrane, by which w…

Лабораторные химико-препаративные упражнения: методы получения промежуточных продуктов искусственных органических пигментов из исходных материалов

1907

Uz vāka izdošanas gads: 1908.

Electrochemical Abatement of Organic Pollutants in Continuous-Reaction Systems through the Assembly of Microfluidic Cells in Series

2015

The electrochemical treatment of wastewater contaminated by organic pollutants was performed under a continuous mode by using, for the first time, various micro-electrochemical cells in series. A synthetic solution of acid orange 7 (AO7), a largely used azoic dye, was chosen as model wastewater. Both the electro-Fenton (EF) method with a cheap compact graphite cathode and electrochemical oxidation (EO) at a boron-doped diamond (BDD) anode were used. EO gave higher abatement of total organic carbon (TOC), but drastically higher energetic consumptions than EF. It is worth mentioning that very different operating conditions were set for EF and EO to optimize their performances. The utilization…

Highly selective and sensitive chromo-fluorogenic detection of the Tetryl explosive using functional silica nanoparticles

2011

Silica nanoparticles containing polyamines and thiol groups have been used as probes for the selective detection of Tetryl. © 2011 The Royal Society of Chemistry.

Reactive Self-Assembly and Specific Cellular Delivery of NCO-sP(EO-stat-PO)-Derived Nanogels

2018

This study presents the reactive self-assembly of isocyanate functional and amphiphilic six-arm, star-shaped polyether prepolymers in water into nanogels. Intrinsic molecular amphiphilicity, mainly driven by the isophorone moiety at the distal endings of the star-shaped molecules, allows for the preparation of spherical particles with an adjustable size of 100-200 nm by self-assembly and subsequent covalent cross-linking without the need for organic solvents or surfactants. Covalent attachment of a fluorescence dye and either the cell-penetrating TAT peptide or a random control peptide sequence shows that only TAT-labeled nanogels are internalized by HeLa cells. The nanogels thus specifical…