Search results for "Fluorescence"
showing 10 items of 2463 documents
Off–on BODIPY-based chemosensors for selective detection of Al3+ and Cr3+versus Fe3+ in aqueous media
2014
[EN] Two new off-on BODIPY-based chemosensors that are highly sensitive for trivalent cations in aqueous solutions are described. Compound 2 exhibits selective sensing of Al3+ and Cr3+ versus Fe3+ through two different channels (UV-vis and fluorescence).
A Highly Luminescent Nitrogen-Doped Nanographene as an Acid- and Metal-Sensitive Fluorophore for Optical Imaging.
2021
Dibenzo[hi,st]ovalene (DBOV) has excellent photophysical properties, including strong fluorescence and high ambient stability. Moreover, the optical blinking properties of DBOV have enabled optical super-resolution single-molecule localization microscopy with an imaging resolution beyond the diffraction limit. Various organic and inorganic fluorescent probes have been developed for super-resolution imaging, but those sensitive to pH and/or metal ions have remained elusive. Here, we report a diaza-derivative of DBOV (N-DBOV), synthesized in eight steps with a total yield of 15%. Nitrogen (N)-bearing zigzag edges were formed through oxidative cyclization of amino groups in the last step. UV-v…
Dual-beam confocal light-sheet microscopy via flexible acousto-optic deflector
2019
Confocal detection in digital scanned laser light-sheet fluorescence microscopy (DSLM) has been established as a gold standard method to improve image quality. The selective line detection of a complementary metal-oxide-semiconductor camera (CMOS) working in rolling shutter mode allows the rejection of out-of-focus and scattered light, thus reducing background signal during image formation. Most modern CMOS have two rolling shutters, but usually only a single illuminating beam is used, halving the maximum obtainable frame rate. We report on the capability to recover the full image acquisition rate via dual confocal DSLM by using an acoustooptic deflector. Such a simple solution enables us t…
CEFLES2: The remote sensing component to quantify photosynthetic efficiency from the leaf to the region by measuring sun-induced fluorescence in the …
2009
The CEFLES2 campaign during the Carbo Europe Regional Experiment Strategy was designed to provide simultaneous airborne measurements of solar induced fluorescence and CO<sub>2</sub> fluxes. It was combined with extensive ground-based quantification of leaf- and canopy-level processes in support of ESA's Candidate Earth Explorer Mission of the "Fluorescence Explorer" (FLEX). The aim of this campaign was to test if fluorescence signal detected from an airborne platform can be used to improve estimates of plant mediated exchange on the mesoscale. Canopy fluorescence was quantified from four airborne platforms using a combination of novel sensors: (i) the prototype ai…
Comparative studies on the detection of benzodiazepines in serum by means of immunoassays (FPIA).
1993
Serum was tested for benzodlazeplnes by fluorescence polarlzatlon Immunoassay (FPIA) on Abbott's ADx system uslng the benzodlazeplne serum reagents (Benzo S) and the benzodlazeplne urine reagents (Benzo U) after pretreatment of speclmens by means of acetone preclpltatlon. The followlng sera were included for comparing the two methods: negatlve sera spiked with varlous benzodlazeplnes; 80 sera randomly selected out of a total of 8654 serum specimens from Impalred drlvers; and blood speclmens from Indlvlduals who stated that they had taken benzodlazeplnes. The different benzodlazeplnes were added to serum st concentratlons of 25, 75, and 300 ng/mL. The low-dose benzodlazeplnes flunltrazepam a…
Intraflagellar transport molecules in ciliary and nonciliary cells of the retina.
2010
IFT proteins are differentially localized in photoreceptor cilia, including within the inner segment, and some are shown to function in trafficking in nonciliated retinal neurons.
Cytoskeletal stabilization of inhibitory interactions in immunologic synapses of mature human dendritic cells with natural killer cells
2011
Abstract Human mature dendritic cells (DCs) can efficiently stimulate natural killer (NK)–cell responses without being targeted by their cytotoxicity. To understand this important regulatory crosstalk, we characterized the development of the immunologic synapse between mature DCs and resting NK cells. Conjugates between these 2 innate leukocyte populations formed rapidly, persisted for prolonged time periods and matured with DC-derived f-actin polymerization at the synapse. Polarization of IL-12 and IL-12R to the synapse coincided with f-actin polymerization, while other activating and inhibitory molecules were enriched at the interface between DCs and NK cells earlier. Functional assays re…
Translocation of the nuclear autoantigen La to cell surface: assembly and disassembly with the extracellular matrix.
1991
La (SS-B) protein is known as one major antigenic target for autoantibodies from patients with certain autoimmune diseases such as Sjogren's syndrome or Lupus Erythematosus. La protein belongs to the so called "extractable nuclear antigens". Here we report that La antigen is not restricted to the nucleus as one might deduce from the exclusive nuclear staining pattern of patient anti-La antibodies but after stimulation of serum-starved cells with 10% fetal calf serum (FCS) appears and stays for at least 45 min at the outer surface of CV-1 cells being available for binding of anti-La antibodies. In addition we found that a minor part of La antigen associates with the extracellular fibronectin…
Binding to complement factors and activation of the alternative pathway by Acanthamoeba.
2010
Acanthamoeba can cause severe ocular and cerebral diseases in healthy and immunocompromised individuals, respectively. Activation of complement appears to play an important role in host defence against infection. The exact mechanism, however, is still unclear. The aim of the present study was to investigate the effect of normal human serum (NHS) and normal mouse serum (NMS) on Acanthamoeba trophozoites, the binding of different complement factors to Acanthamoeba and the activation of the complement system. Moreover, we aimed to work out any possible differences between different strains of Acanthamoeba. A virulent T4 strain, a non-virulent T4 strain and a virulent T6 strain were included in…
Neuronal activity and secreted amyloid β lead to altered amyloid β precursor protein and presenilin 1 interactions.
2013
Deposition of amyloid β (Aβ) containing plaques in the brain is one of the neuropathological hallmarks of Alzheimer's disease (AD). It has been suggested that modulation of neuronal activity may alter Aβ production in the brain. We postulate that these changes in Aβ production are due to changes in the rate-limiting step of Aβ generation, APP cleavage by γ-secretase. By combining biochemical approaches with fluorescence lifetime imaging microscopy, we found that neuronal inhibition decreases endogenous APP and PS1 interactions, which correlates with reduced Aβ production. By contrast, neuronal activation had a two-phase effect: it initially enhanced APP-PS1 interaction leading to increased …