Search results for "asma"
showing 10 items of 4204 documents
Determination of mineral and trace element concentrations in pine needles by ICP-OES: evaluation of different sample pre-treatment methods
2008
In the present study, the determination of mineral and trace elements (Al, B, Ca, Cu, Fe, K, Mg, Mn, Na, P and Zn) from pine needles using three sample pre-treatment methods followed by inductively coupled plasma optical emission spectrometry, was examined. Sample pre-treatment methods tested were microwave digestion, ultrasound-assisted digestion and dry ashing. The new ultrasound-assisted digestion method was optimised by the analysis of the standard reference material (SRM) 1575a (pine needles) sample. The speed of dry ashing method was significantly increased by ultrasound dissolution after ashing. All the ICP-OES measurements were performed in robust plasma conditions which were tested…
Direct determination of minerals in human diets by infrared spectroscopy and X-ray fluorescence
2014
The use of near and mid infrared spectroscopy and X-ray fluorescence (XRF) to determine the concentration of mineral elements in Spanish human diets was investigated. Thirty-five commercial baby foods, 6 children fast food menus and 13 university canteen menu samples were analysed by infrared and XRF spectroscopy and spectra evaluated by using reference data obtained by inductively coupled plasma optical emission spectroscopy (ICP-OES). Models for calcium, potassium, iron, magnesium, sodium and zinc determination were built and validated. Spectra were pre-treated by using different pre-processing algorithms (multiplicative scatter correction, standard normal variation, first derivate, ortho…
Aggregation versus Biological Activity in Gold(I) Complexes. An Unexplored Concept
2021
The aggregation process of a series of mono- and dinuclear gold(I) complexes containing a 4-ethynylaniline ligand and a phosphane at the second coordination position (PR3-Au-C≡CC6H4-NH2, complexes 1-5, and (diphos)(Au-C≡CC6H4-NH2)2, complexes 6-8), whose biological activity was previously studied by us, has been carefully analyzed through absorption, emission, and NMR spectroscopy, together with dynamic light scattering and small-angle X-ray scattering. These experiments allow us to retrieve information about how the compounds enter the cells. It was observed that all compounds present aggregation in fresh solutions, before biological treatment, and thus they must be entering the cells as a…
Community effects allow bioelectrical reprogramming of cell membrane potentials in multicellular aggregates: Model simulations.
2020
Bioelectrical patterns are established by spatiotemporal correlations of cell membrane potentials at the multicellular level, being crucial to development, regeneration, and tumorigenesis. We have conducted multicellular simulations on bioelectrical community effects and intercellular coupling in multicellular aggregates. The simulations aim at establishing under which conditions a local heterogeneity consisting of a small patch of cells can be stabilized against a large aggregate of surrounding identical cells which are in a different bioelectrical state. In this way, instructive bioelectrical information can be persistently encoded in spatiotemporal patterns of separated domains with diff…
Precision experiments on exotic nuclei at IGISOL
2006
Abstract Cooling and trapping techniques of low-energy radioactive ion beams of refractory elements employed at the IGISOL facility are presented with emphasis on high-precision measurements of the ground state properties of exotic nuclei. The impact of the new generation Paul and Penning traps on mass measurements of short-lived nuclei is discussed with examples on precision measurements of masses of super-allowed beta emitters and neutron-rich nuclei. As a new concept the trap-assisted spectroscopy of radioactive ions is presented with applications in collinear laser spectroscopy, decay spectroscopy of isobarically purified sources and in nuclear cross-section measurements by ion counting.
Excitation and detection geometries for Fourier-transform mass spectometry
1994
A short overview of current excitation and detection techniques for Fourier-transform mass spectrometry and related ion cyclotron resonance experiments is given, and some ideas are discussed which may lead to new developments.
First Fourier-transform ion cyclotron resonance signals of very highly charged atomic ions
1994
We report on the first application of Fourier-transform ion cyclotron resonance mass spectrometry to the very highly charged ions produced in the high-energy electron beam ion trap (SuperEBIT) at the Lawrence Livermore National Laboratory. Initial results are described, and spectra are presented from ions as highly charged as Cs53+.
Spatial separation of atomic states in a laser cooled ion crystal
1999
A laser cooled ion crystal containing several hundred Ca+ ions has been stored in a linear Paul trap. Cooling is provided by a red detund laser at the 4S1/2−4P1/2 resonance transition. A second laser serves for repumping of those ions which decay from the excited 4P1/2 level to the metastable 3D3/2 state. The ions can be additionally excited by a third laser to a long lived metastable 3D5/2 energy level which decouples them from the cooling laser radiation. The light pressure acting upon the laser cooled ions pushes them into the direction of the laser beam. The ions in the metastable 3D5/2 state, however, do not experience any light pressure force and diffuse to the crystal side which poin…
Quantification of growth factors by using a new system for obtaining platelet-rich plasma
2010
Objective: To verify the performance of a new method for obtaining platelet-rich plasma, while avoiding contami- nation of the sample during its processing. Study Design: Twenty healthy patients were selected, from whom 21 ml of blood was etracted. �e then pro- Design: Twenty healthy patients were selected, from whom 21 ml of blood was etracted. �e then pro- esign: Twenty healthy patients were selected, from whom 21 ml of blood was etracted. �e then pro- ceeded to study the platelets and growth factors in basal blood after centrifuging the sample by using a new closed system for obtaining platelet-rich plasma (PRP). Results: After centrifuging the blood sample, double the amount of platelet…
Photobinding of Tiaprofenic Acid and Subprofen to Proteins and Cells: A Combined Study Using Radiolabeling, Antibodies and Laser Flash Photolysis of …
1998
Drug photoallergy is a matter of current concern. It involves the formation of drug-protein photoadducts (photoantigens) that may ultimately trigger an immunological response. Tyrosine residues appear to be key binding sites in proteins. The present work has investigated the photobinding of tiaprofenic and (TPA) and the closely related isomer suprofen (SUP) to proteins and cells by means of radioactive labeling and drug-directed antibodies. To ascertain whether preassociation with the protein may play a role in photoreactivity, two model bichromophoric compounds (TPA-Tyr and SUP-Tyr) have been prepared and studied by laser flash photolysis. The results of this work show that (a) TPA and SUP…