Search results for "Fluorescence"
showing 10 items of 2463 documents
Aryl hydrocarbon receptor activation by cAMP vs. dioxin: divergent signaling pathways.
2005
Even before the first vertebrates appeared on our planet, the aryl hydrocarbon receptor ( AHR ) gene was present to carry out one or more critical life functions. The vertebrate AHR then evolved to take on functions of detecting and responding to certain classes of environmental toxicants. These environmental pollutants include polycyclic aromatic hydrocarbons (e.g., benzo[ a ]pyrene), polyhalogenated hydrocarbons, dibenzofurans, and the most potent small-molecular-weight toxicant known, 2,3,7,8-tetrachlorodibenzo- p -dioxin (TCDD or dioxin). After binding of these ligands, the activated AHR translocates rapidly from the cytosol to the nucleus, where it forms a heterodimer with aryl hydroc…
Modeling X-ray emission from stellar coronae
2008
By extrapolating from observationally derived surface magnetograms of low-mass stars we construct models of their coronal magnetic fields and compare the 3D field geometry with axial multipoles. AB Dor, which has a radiative core, has a very complex field, whereas V374 Peg, which is completely convective, has a simple dipolar field. We calculate global X-ray emission measures assuming that the plasma trapped along the coronal loops is in hydrostatic equilibrium and compare the differences between assuming isothermal coronae, or by considering a loop temperature profiles. Our preliminary results suggest that the non-isothermal model works well for the complex field of AB Dor, but not for the…
Zinc(II) complexes of amide- and urea-substituted 8-hydroxyquinolines
2002
Abstract A series of amide- and urea-substituted 8-hydroxyquinoline ligands 1–6-H are used for the formation of zinc(II) complexes. Hereby in general 2:1 complexes are obtained and the X-ray structure of [(3)2Zn] reveals the presence of a coordination polymer in the solid state. Only the derivatives of 7-amino-8-hydroxyquinoline 4-H and 5-H form trinuclear hexa-helical 6:3 complexes which exhibit interesting structural and NMR and fluorescence spectroscopic properties.
Mutation Analysis of Core Binding Factor A1 in Patients with Cleidocranial Dysplasia
1999
SummaryCleidocranial dysplasia (CCD) is a dominantly inherited disorder characterized by patent fontanelles, wide cranial sutures, hypoplasia of clavicles, short stature, supernumerary teeth, and other skeletal anomalies. We recently demonstrated that mutations in the transcription factor CBFA1, on chromosome 6p21, are associated with CCD. We have now analyzed the CBFA1 gene in 42 unrelated patients with CCD. In 18 patients, mutations were detected in the coding region of the CBFA1 gene, including 8 frameshift, 2 nonsense, and 9 missense mutations, as well as 2 novel polymorphisms. A cluster of missense mutations at arginine 225 (R225) identifies this residue as crucial for CBFA1 function. …
Electronic Excitation Energy Transfer in Multichromophoric Assemblies: A Single Molecule Insight
2009
In recent years, single molecule spectroscopy has provided novel insights into the fundamentals of electronic excitation energy transfer in molecular aggregates. In order of increasing structural complexity, we have studied simple molecular dimers and multichromophoric dendrimers. It will be shown that the combination of frequency-selective single molecule spectroscopy and confocal fluorescence microscopy at 1.4 K is a unique tool to study energy transfer processes in these systems. In particular, from the line widths of single molecule excitation spectra, rate constants of energy transfer can be deduced directly. A detailed analysis shows that, for several cases, the mechanism of energy tr…
Single-molecule controlled emission in planar plasmonic cavities
2014
International audience; We study the fluorescence emission from single dye molecules in coplanar plasmonic cavities composed of a thin gold film surrounded by two in-plane surface plasmon Bragg mirrors. We first discuss the effect of the presence of Bragg mirrors on the radiation diagram of surface plasmon coupled emission. Then, we investigate the role of the planar cavity size by single-molecule fluorescence lifetime imaging. Experimental data are compared to numerical simulations of the decay rates calculated as a function of the molecule orientation and position within the cavity. The creation of new decay channels by coupling to the cavity modes is also discussed. We measure a plasmoni…
Aluminum Plasmonics: Fabrication and Characterization of Broadly Tunable Plasmonic Surfaces for Plasmon Molecule Strong-Coupling and Fluorescence Enh…
2018
Our work based on previous studies [1, 2] confirms, that simple aluminum nanostructures can be utilized as effective plasmonic resonators over a broad range of frequencies and wavelengths. The nanostructured surfaces, fabricated by electron-beam lithography demonstrated relatively narrow-band resonances and are suitable for various plasmonic applications ranging from metal enhanced fluorescence to strong-coupling [1, 2, 3, 4, 5] experiments. We represent data for molecule-plasmon coupling near the strong coupling limit and demonstrate that these aluminum structures do act as fluorescence increasing substrates. In this work, we used two different types of dyes. We studied the narrow band j-a…
Measuring Spatiotemporal Dependencies in Bivariate Temporal Random Sets with Applications to Cell Biology
2008
Analyzing spatiotemporal dependencies between different types of events is highly relevant to many biological phenomena (e.g., signaling and trafficking), especially as advances in probes and microscopy have facilitated the imaging of dynamic processes in living cells. For many types of events, the segmented areas can overlap spatially and temporally, forming random clumps. In this paper, we model the binary image sequences of two different event types as a realization of a bivariate temporal random set and propose a nonparametric approach to quantify spatial and spatiotemporal interrelations using the pair correlation, cross-covariance, and the Ripley K functions. Based on these summary st…
MICRODISSECTION AND DOP-PCR-BASED REVERSE CHROMOSOME PAINTING AS A FAST AND RELIABLE STRATEGY IN THE ANALYSIS OF VARIOUS STRUCTURAL CHROMOSOME ABNORM…
1996
Reverse chromosome painting has become a powerful tool in clinical genetics for the characterization of cytogenetically unclassifiable aberrations. In this report, the application of a sensitive and rapid procedure for the complete and precise identification of four different de novo structural chromosome abnormalities is presented. These chromosome rearrangements include a marker derived from chromosome 3(cen-q11), an interstitial deletion of chromosome 13 [del(13)(q14q22)], an unbalanced translocation [46,XY, -4, +der(4)t(4;8)(p 15.2;p21.1)] leading to Wolf-Hirschhorn syndrome, and a partial inverted duplication in conjunction with a partial deletion of chromosome 5p [46,XX, -5, +der(5)(:…
Global and time-resolved monitoring of crop photosynthesis with chlorophyll fluorescence
2014
Guanter, Luis et al.