Search results for "Fluorescence"
showing 10 items of 2463 documents
Metodes izstrāde oligonukleotīdu saistības termodinamisku parametru noteikšanai
2020
Maģistra darbā ir oligonukleotīdu dizainēšana, lai varētu detektēt fluorescentus kušanas līknes. Literatūras apskatā aprakstītas metodes, kas pielietotas oligonukleotīdu termodinamisko parametru noteikšanai. Tika izpētīti optimālie parametri fluorescentu kušanas grafiku uzņemšanai. Iegūtie rezultāti paver iespēju jaunai metodei, lai izpētītu termodinamiskos parametrus oligonukleotīdiem.
COX-2 ekspresijas inducēšana LPS iekaisuma modelī neiroblastomas SH-SY5Y šūnu līnijā
2015
COX-2 ir COX izoenzīms, kas atbild par arahidonskābes metabolismu, sintezējot bioloģiski aktīvus iekaisuma mediatorus – prostanoīdus. Perifērijā COX-2 ir inducējama izoforma, bet smadzenēs – konstitutīva. Šī darba mērķis bija izpētīt LPS spēju inducēt COX-2 ekspresiju neiroblastomas SH-SY5Y šūnās. COX-2 ekspresijas noteikšanai tika izmantota imūnfluorescences metode. Rezultāti uzrādīja SH-SY5Y šūnu morfoloģijas izmaiņas dažādu LPS koncentrāciju (5 – 800 ng/ml) ietekmē. Pētījumā novēroja COX-2 ekspresiju kontroles šūnās normālos apstākļos, LPS koncentrācijā 5 ng/ml COX-2 ekspresijas indukciju, bet koncentrācijā 25 ng/ml un 50 ng/ml – supresiju. Statistiski ticamu rezultātu uzrādīja LPS konce…
Autoantibody detection using indirect immunofluorescence on HEp-2 cells
2009
The detection of autoantibodies is an important element in the diagnosis and monitoring of disease progression in patients with autoimmune diseases. In laboratory diagnostic tests for connective tissue and autoimmune liver diseases, indirect immunofluorescence on HEp-2 cells plays a central role in a multistage diagnostic process. Despite the high quality of diagnostics, findings at different laboratories can differ considerably due to a lack of standardization, as well as subjective factors. The present paper formulates recommendations for the standardized processing and interpretation of the HEp-2 cell test for the detection of non-organ-specific (especially antinuclear) antibodies. It pr…
Conformational Transitions upon Maturation Rule Surface and pH-Responsiveness of α-Lactalbumin Microparticulates
2021
De novo designed protein supramolecular structures are nowadays attracting much interest as highly performing biomaterials. While a clear advantage is provided by the intrinsic biocompatibility and...
Ethane-Bridged Zinc-Porphyrin Dimers in Langmuir-Shäfer Thin Films: Structural and Spectroscopic Properties
2006
This work reports on the structural and spectroscopic properties of ethane-bridged Zn porphyrin dimers (1) in Langmuir-Scha¨fer (LS) thin films by combining scanning force microscopy (SFM) with film balance, UV-vis absorption, fluorescence, and nanosecond laser flash photolysis measurements. Results show that depending on the surface pressure the Langmuir films of pure 1 can be arranged in two different condensed phases, whereas SFM of the LS films shows characteristic fractal networks constituted by nanoscopic aggregates. The spectral findings agree with a picture in which 1 is apparently present in the anti conformation but aggregated in a sort of H-type structure whose optical features r…
Fluorescence Microscopy Studies of Structure Formation in Surfactant Monolayers
1993
Monolayers of water-insoluble surfactants (Langmuir monolayers) are important model system in basic research for studying the self-organization of organic molecules into two-dimensional layers [1, 2]. These floating films are also the basis for the build-up of complex multilayered structures on solid substrates, so-called Langmuir—Blodgett films (LB-films), which are of considerable interest in fundamental science and promise some future practical applications [3].
Lanthanide complexes as imaging agents anchored on nano-sized particles of boehmite
2011
International audience; The synthesis of boehmite nanoparticles modified with lanthanides (Eu, Tb and Gd) is described. Their synthesis, characterization and in vitro assays with HeLa cells were performed. The nuclear magnetic relaxation dispersion (NMRD) profiles of the two chelating moieties were studied. Imaging data from laser scanning confocal fluorescence microscopy and flow cytometry revealed that the nanoscaffolds were taken up by the cells, distributed throughout the cytoplasm and showed no toxicity. This platform could represent an alternative to silica-based inert matrices as imaging vehicles.
Coordinatively Unsaturated Lanthanide(III) Helicates: Luminescence Sensors for Adenosine Monophosphate in Aqueous Media
2016
Coordinatively unsaturated double-stranded helicates [(H2 L)2 Eu2 (NO3 )2 (H2 O)4 ](NO3 )4 , [(H2 L)2 Tb2 (H2 O)6 ](NO3 )6 , and [(H2 L)2 Tb2 (H2 O)6 ]Cl6 (H2 L=butanedioicacid-1,4-bis[2-(2-pyridinylmethylene)hydrazide]) are easily obtained by self-assembly from the ligand and the corresponding lanthanide(III) salts. The complexes are characterized by X-ray crystallography showing the helical arrangement of the ligands. Co-ligands at the metal ions can be easily substituted by appropriate anions. A specific luminescence response of AMP in presence of ADP, ATP, and other anions is observed. Specificity is assigned to the perfect size match of AMP to bridge the two metal centers and to replac…
White light emitting silsesquioxane based materials: the importance of a ligand with rigid and directional arms
2022
The synthesis of a novel polyhedral oligomeric silsesquioxane functionalized with eight rigid and directional terpyridine-based arms (Ter-POSS) was successfully achieved via a Sonogashira reaction. The POSS based ligand was extensively characterized using different techniques including 1H, 13C and 29Si NMR as well as UV-Vis and fluorescence spectroscopies. The assembly of these nano-caged units in the presence of different transition metal ions (Fe2+, Zn2+ and Cu2+) as well as of a cation from the lanthanides (Eu3+) was investigated using absorption and emission spectroscopies. The final materials display an evident emission in different regions of the visible spectrum as a function of the …
Time resolved confocal luminescence investigations on reverse proton exchange Nd : LiNbO3 channel waveguides
2009
In this work we report on the time and spatial resolved fluorescence of Neodymium ions in LiNbO(3) channel waveguides fabricated by Reverse Proton Exchange. The analysis of the fluorescence decay curves obtained with a sub-micrometric resolution has evidenced the presence of a relevant fluorescence quenching inside the channel waveguide. From the comparison between diffusion simulations and the spatial dependence of the (4)F(3/2) fluorescence decay rate we have concluded that the observed fluorescence quenching can be unequivocally related to the presence of H+ ions in the LiNbO(3) lattice. Nevertheless, it turns out that Reverse Proton Exchange guarantees a fluorescence quenching level sig…