Search results for "Probe"

Monitoring Electron-Photon Dressing in WSe 2

2016

Optical pumping of solids creates a non-equilibrium electronic structure where electrons and photons combine to form quasiparticles of dressed electronic states. The resulting shift of electronic levels is known as the optical Stark effect, visible as a red shift in the optical spectrum. Here we show that in a pump-probe setup we can uniquely define a non-equilibrium quasiparticle bandstructure that can be directly measurable with photoelectron spectroscopy. The dynamical photon-dressing (and undressing) of the many-body electronic states can be monitored by pump-probe time and angular resolved photoelectron spectroscopy (tr-ARPES) as the photon-dressed bandstructure evolves in time dependi…

CHARACTERIZATION OF IRON COMPOUNDS FROM URBAN AND RURAL AEROSOL SOURCES

2000

Abstract Iron plays an important role in the chemistry and physics (by varying the hygroscopicity) of the atmosphere. Bulk samples were taken from an air-conditioning device, from the electrofilter of a gas–oil power station of the Technical University of and from rural sites near Darmstadt, situated between medium-altitude mountains and with a climate dominated by air masses from the west. Samples were collected in urban and rural (meadow) air, from different waste incineration power stations, from the exhausts of a gasoline and from a diesel motor car, and from a private gas fired heating system. The samples were characterized for elemental composition by total reflection X-ray fluorescen…

A new fluorescent "turn-on" chemodosimeter for the detection of hydrogen sulfide in water and living cells

2013

[EN] A new fluorescent turn-on probe for the selective detection of hydrogen sulfide in water and living cells based on a 8-hydroxyquinoline fluorophore functionalized with a 2,6-dinitrophenyl ether moiety has been developed.

A micellar multitasking device: sensing pH windows and gauging the lipophilicity of drugs with fluorescent signals.

2010

A multitasking fluorescent device can be obtained by forming micelles of Triton X-100, containing a lipophilic macrocyclic Cu(2+) complex and the coordinating fluorophore Coumarin 343 (C343), which features a COOH moiety. At low pH the two micellised components do not interact, and the fluorescence of Courmarin 343 (C343) is intense. At intermediate pH, C343 is deprotonated and coordinates to the Cu(2+) centre in its apical position, with fluorescence quenching. At higher pH the deprotonated C343 is displaced from Cu(2+) by the formation of an OH(-) complex, and the fluorescence is revived. This allows the system to carry out its first task as it behaves as an "on-off-on" fluorescent sensor…

Noble Gases as Magnetic Probes in Fullerene Chemistry

2016

Substrate templating guides the photoinduced reaction of C60on calcite

2014

cited By 7; International audience; A substrate-guided photochemical reaction of C60 fullerenes on calcite, a bulk insulator, investigated by non-contact atomic force microscopy is presented. The success of the covalent linkage is evident from a shortening of the intermolecular distances, which is clearly expressed by the disappearance of the moiré pattern. Furthermore, UV/Vis spectroscopy and mass spectrometry measurements carried out on thick films demonstrate the ability of our setup for initiating the photoinduced reaction. The irradiation of C60 results in well-oriented covalently linked domains. The orientation of these domains is dictated by the lattice dimensions of the underlying c…

Zvaigžņotā Debess: 2011, Pavasaris (211)

2011

Contents: “ZVAIGŽŅOTĀ DEBESS” FORTY YEARS AGO: A.Alksnis. XIV General Assembly of the International Astronomical Union (abridged) ; H.Strods. Jaunlaicene’s Watchmaker (abridged) ; I.Daube. At the Radioastrophysical Observatory of the Latvian Academy of Sciences (abridged). 50 YEARS SINCE GAGARIN’S SPACE FLIGHT: R.Misa. Dream about Cosmos ; A.Zalcmane. Konstantin Tsiolkovsky Astronautics Museum in Kaluga; E.Bērziņa. Outer Space in Pauls Stradins Museum of History of Medicine. NEWS: A.Alksnis. Different Faces of Whirpool Galaxy ; A.Alksnis. The Kleopatra’s Trio and other Minor Planets Groups. SPACE RESEARCH and EXPLORATION: V.Kalniņš. NASA Preparing Solar Probe Plus to Plunge into Sun's Atmos…

DNA sequence and pattern of expression of the sea urchin (Paracentrotus lividus) alpha-tubulin genes.

1989

To study the molecular aspects of the regulation of transcription of a multigene family, we have isolated and sequenced cDNA and genomic clones coding for the alpha-tubulin of the sea urchin Paracentrotus lividus. Two cDNA clones, P alpha 10 and P alpha 4, contain respectively the coding information for 391 C-terminal and for 338 N-terminal amino acids of the 452 residues that constitute the complete protein. They show silent nucleotide substitutions only, suggesting that P alpha 10 and P alpha 4 represent the cloned copies of two allelic gene transcripts, which encode for two alpha-tubulin isoforms with identical amino acid sequence in the region of the overlap. The comparison of the predi…

Human type I cytokeratin genes are a compact cluster

1997

A YAC clone (211F11) containing approximately 0.5 Mb of human DNA was isolated from a human genomic library by PCR-based screening with cytokeratin (KRT) 13-specific primers. The YAC clone was mapped by FISH to the long arm of chromosome 17 (17q12→q21), a region to which several other type I KRT genes had been mapped previously. We now show by Southern blot hybridization and PFGE analyses that KRT13, 14, 15, and 16 are all contained within YAC clone 211F11. Long-range restriction mapping analysis of clone 211F11 and of two smaller YAC clones that were also isolated with KRT13-specific primers, suggests that KRT13, 14, 15, 16 and their linked type I genes KRT17 and 19, are contained in less …

Tetrasomy 18p de novo: Identification by FISH with conventional and microdissection probes and analysis of parental origin and formation by short seq…

1996

We report a de novo supernumerary isochromosome 18p in a child with tetrasomy 18p, analyzed by a straightforward combination of cytogenetic and molecular cytogenetic methods. The diagnostic procedure consisted of standard banding techniques and fluorescence in situ hybridization (FISH) with centromere and library DNA probes for chromosome 18, and 18p-specific FISH probes prepared by chromosome microdissection and in vitro amplification. The maternal origin as well as the most probable cell stages of formation of the supernumerary isochromosome were determined by typing of short sequence repeats (SSRs). The pattern of allelic distribution suggests a nondisjunction during meiosis followed by …