Search results for "Fluorescence"
showing 10 items of 2463 documents
OPTICAL SENSING OF POLLUTANTS BY FLUORESCENT CARBON NANODOTS
2022
Ultrafast broadband fluorescnce up-conversion of N-acetyl-L-tryptophanamide (NATA)
2011
MIXING TIME IN UNBAFFLED STIRRED TANKS
2012
Unbaffled stirred tanks, despite their poorer mixing performance with respect to baffled vessels, are gaining a growing industrial interest as they provide significant advantages in selected applications, including a number of biochemical, food and pharmaceutical processes. There still is however a general lack of information on their mixing performance, that needs to be addressed in order to fully exploit their application potential. The present work is aimed at providing experimental information on mixing rates in an unbaffled vessel operated without top-cover (Uncovered Unbaffled Stirred Tank, UUST). The planar laser induced fluorescence (PLIF) technique was adopted for measuring the dis…
Techniques to evaluate erythrocyte deformability in diabetes mellitus
2005
Using several rheological techniques, we examined the erythrocyte deformability in different groups of diabetic subjects. The macrorheological techniques used for this evaluation were respectively whole-blood filtration, filtration of erythrocyte suspensions, polyviscosimetry and diffractometry. Whole-blood filterability, at a negative pressure of 20 cm water, was decreased in type 2 diabetics; no difference was evident at a negative pressure of 10 cm water. The filtration of erythrocyte suspensions at low haematocrit (5%) did not show differences between normal and diabetic subjects. The polyviscosimetry, which explores the filterability of erythrocyte suspensions at high haematocrit (80%)…
Potentialgesteuerte SS-Bindungsspaltung und Fluoreszenzmarkierungsstudien am Beispiel des Rinderinsulins
1985
Die drei SS-Brucken im Insulin konnen galvanostatisch unter Bildung der SH-A-Kette und der SH-B-Kette (Produktgemisch I) aufgespalten werden. Potentiostatisch gelingt bei -1.3 V (vs. SCE) die selektive Offnung der zwei interchenaren Disulfidbrucken (Produktgemisch II). Die vier SH-Gruppen im Produktgemisch II werden mit dem Vinylsulfon 1 blockiert (Produktgemisch III). Im Produktgemisch III wird die intrachenare Disulfidbrucke in der teilblockierten A-Kette bei -1.8 V (vs. SCE) potentiostatisch reduktiv geoffnet und mit dem fluoreszierenden Arylvinylsulfon 2 geschutzt (Produktgemisch IV). Auch die SH-Gruppen in den Produktgemischen I und II werden durch die fluoreszierenden Vinylsulfone 2 u…
Gezielte und reversible Fluoreszenzmarkierung von SH-Lysozym mit Vinylsulfonen
1985
Am Beispiel von SH-Lysozym wird gezeigt, wie man SH-Gruppen reversibel mit den Vinylsulfonen 1–4 nach Gl. (a) selektiv blockieren und nach Gl. (b) selektiv deblockieren kann. Das wasserlosliche Vinylsulfon 2 macht das blockierte SH-Lysozym wasserloslich. Durch Einwirkung von NaOH-Losung wird nach Gl. (b) das wasserunlosliche SH-Lysozym regeneriert. Die fluoreszierenden Vinylsulfone 3 und 4 konnen als Fluoreszenzmarker nach verschiedenen Arbeitsweisen zum qualitativen Nachweis und zur quantitativen Bestimmung von SH-Gruppen herangezogen werden. Selective and Reversible Fluorescence Marking of SH-Lysozyme with Vinyl Sulfones The SH groups of SH-lysozyme as a model substance are selectively bl…
Electron transfer mechanism in Shewanella loihica PV-4 biofilms formed at graphite electrode
2012
Abstract Electron transfer mechanisms in Shewanella loihica PV-4 viable biofilms formed at graphite electrodes were investigated in potentiostat-controlled electrochemical cells poised at oxidative potentials (0.2 V vs. Ag/AgCl). Chronoamperometry (CA) showed a repeatable biofilm growth of S. loihica PV-4 on graphite electrode. CA, cyclic voltammetry (CV) and its first derivative shows that both direct electron transfer (DET) mediated electron transfer (MET) mechanism contributes to the overall anodic (oxidation) current. The maximum anodic current density recorded on graphite was 90 μA cm − 2 . Fluorescence emission spectra shows increased concentration of quinone derivatives and riboflavi…
Accretion shock on CTTSs and its X-ray emission
2009
High spectral resolution X-ray observations of classical T Tauri stars (CTTSs) demonstrate the presence of plasma at T~2-3×10^6 K and ne~10^11-10^13 cm-3. Stationary models suggest that this emission is due to shock-heated accreting material. We address this issue by a 1-D hydrodynamic model of the impact of the accretion flow onto a chromosphere of a CTTS with the aim of investigating the stability of accretion shock and the role of the chromosphere. Our simulations include the effects of gravity, radiative losses from optically thin plasma, the thermal conduction and a detailed modeling of the stellar chromosphere. Here we present the results of a simulation based on the parameters of the…
Morphological distribution of μ chains and cd15 receptors in colorectal polyp and adenocarcinoma specimens
2013
BACKGROUND: We have recently investigated the localisation of immunoglobulin-producing cells (IPCs) in inflamed intestinal tissue samples from patients with inflammatory bowel disease (IBD), and identified two main patterns of B lymphocyte infiltration: one characterised by the moderate strong stromal localisation of small B1 cell-like IgM+/CD79+/CD20-/CD21-/CD23-/CD5 ± IPCs, and the other by the peri-glandular localisation of IPCs with irregular nuclei that had surface markers specific for a B cell subset (IgM and CD79), but quantitative differences in their λ and κ chains. The same patients were also tested for CD15+ receptors, which were localised on inflammatory cell surfaces or in the …
Isolation and Characterization of an Fe(III)-Chelating Compound Produced by Pseudomonas syringae
1986
The phytopathogenic bacterium Pseudomonas syringae produces a fluorescent pigment when it is grown in iron-deficient media. This pigment forms a very stable Fe(III) complex that was purified in this form by using a novel procedure based on ultrafiltration and column chromatography. The Fe(III) complex has a molecular weight of 1,100 and contains 1 mol of Fe(III). The pigment is composed of an amino acid moiety with three threonines, three serines, one lysine, δ- N -hydroxyornithine, and a quinoline-type fluorescent chromophore. These features and its stability constant (in the range of 10 32 ) suggest that the fluorescent pigment of P. syringae is related to the siderophores produced by an…