Search results for "OCT"
showing 10 items of 3052 documents
Buffer-gas-free mass-selective ion centering in Penning traps by simultaneous dipolar excitation of magnetron motion and quadrupolar excitation for i…
2012
A new excitation scheme of the radial ion-motional modes is introduced for Penning-trap ion-cyclotron-resonance experiments. By simultaneous dipolar excitation of the magnetron motion and resonant quadrupolar excitation for the conversion between magnetron motion and cyclotron motion, a mass-selective recentering of the ions of interest is performed while all other (contaminant) ions are ejected from the trap. This new technique does not rely on the application of a buffer gas as presently used [G. Savard, St. Becker, G. Bollen, H.-J. Kluge, R.B. Moore, Th. Otto, L Schweikhard, H. Stolzenberg, U. Wiess, Physics Letters A 158 (1991) 247] and will thus prevent charge-exchange reactions and da…
Ferromagnetic coupled μ-phenoxo-μ-carboxylato heterodinuclear complexes based on the Cr(salen) moiety: Structural and magnetic characterization
2009
The synthesis, crystal structure, and magneto-chemical characterization of two new unprecedented μ-phenoxo-μ-carboxylato heterodinuclear complexes based on the Cr(salen) moiety (salen = N,N′-bis(salicylidene)ethylenediamine), [MII(O2C(CH3)3)(OH2)2(μ-O2C(CH3)3)(μ-salen)CrIII(O2C(CH3)3)], M = Ni (2), Co(3) are reported. The dinuclear complexes were obtained starting from the mononuclear trans-[Cr(salen)(CN)2]PPh4 (1), whose crystal structure is also reported. They show a trans arrangement of the Cr(salen) unit, bridging through the phenolate O atoms to a second metal center. An additional μ2-O2-carboxylato bridge and a further monodentating carboxylate ligand complete the roughly octahedral C…
Iridokorneālā leņķa novērtēšana optometrista praksē
2016
Bakalaura darbs ir uzrakstīts latviešu valodā uz 29 lapām. Tas satur 19 attēlus, 7 tabulas un 33 atsauces uz literatūras avotiem. Darba mērķis: novērtēt, cik precīzi optometristu praksē iespējams noteikt iridokorneālā leņķa platumu un kādi faktori var ietekmēt šī leņķa lielumu. Metode: iridokorneālais leņķis (IKL) tika novērtēts ar van Herick metodi, izmantojot spraugas lampu, dažādos apgaismojuma apstākļos un priekšējā segmenta optiskās koherences tomogrāfu (AS-OCT). Rezultāti un secinājumi: lai precīzāk raksturotu IKL, jāpapildina van Herick metodes raksturojošās pakāpes. Apgaismojumam mainoties no mezopiskiem uz fotopiskiem apstākļiem, IKL tiek novērtēts par 1-2 pakāpēm platāks. Dalībnie…
Ricerche in tema di società questuarie
2019
Intorno al regime delle società di tipo questuario – riconducibili agli schemi teorici della societas universorum quae ex quaestu veniunt – e delle società unius alicuius negotiationis e unius rei, si profusero gli sforzi interpretativi dei giuristi romani, fin dalla fine dell’età repubblicana. La monografia scientifica ripercorre le tracce della individuazione della nozione stessa di quaestus (guadagno), con particolare riferimento alla inclusione al suo interno delle donazioni cd. remuneratorie; ancora, ricostruisce il dibattito giurisprudenziale sorto intorno alla questione se i soci – nella determinazione delle quote – dovessero rispettare una proporzione rispetto ai conferimenti, con u…
External pressure and composition effects on the atomic and electronic structure of SnWO4
2015
The atomic and electronic structure of tin tungstates, α-SnWO4, α-Sn1.03W0.99O4 and β-SnWO4 ,w as studied by the W L3-edge X-ray absorption spectroscopy and first-principles linear combination of atomic orbital (LCAO) calculations based on the hybrid exchange-correlation density functional (DFT)/ Hartree–Fock (HF) scheme. It was found that the crystal structure of both α-phases is built up of strongly distorted WO6 octahedra, whereas that of β-SnWO4 is composed of nearly regular WO4 tetrahedra. In addition, there are distorted SnO6 octahedra in both α- and β-phases. The metal–oxygen octahedra distortion is explained by the second-order Jahn–Teller effect. The influence of pressure on the st…
Interaction of Cd(II) and Ni(II) terpyridine complexes with model polynucleotides: A multidisciplinary approach
2016
Two metal complexes of 2,2′:6′,2′′-terpyridine (terpy), i.e. Cd(terpy)Cl2 and Ni(terpy)Cl2·3H2O, have been prepared and extensively characterized. The interaction of Cd(terpy)Cl2 with synthetic DNA models, poly(dA-dT)·poly(dA-dT) (polyAT) and poly(dG-dC)·poly(dG-dC) (polyGC), has been studied by CD, fluorescence and UV-vis electronic absorption spectroscopy at several metal/polynucleotide–phosphate ratios and for different NaCl concentrations. All the experimental results indicate an intercalative mechanism of interaction. The optimized geometry of the cadmium complex intercalated between the sixth and seventh base pairs of (AT) and (GC) dodecanucleotide duplexes, obtained by quantum mechan…
Interactions of amino acids with aluminum octacarboxyphthalocyanine hydroxide. Experimental and DFT studies
2017
The influence of albumin and amino acids (l-serine, glycine, l-histidine, l-tryptophan, l-cysteine) on the properties of aluminum octacarboxyphthalocyanine hydroxide (Al(OH)PcOC) was investigated in a phosphate buffer (pH 8.0). Particular attention was paid to the spectroscopic properties and photostability of Al(OH)PcOC. The effect of albumin or amino acids on the photodegradation of Al(OH)PcOC was examined in water using red light: 685 nm and daylight irradiation. Analysis of kinetic curves indicated that interaction with those molecules increases the photostability of Al(OH)PcOC. The molecular structure of Al(OH)PcOC complexes (in vacuum and in water) with axially or equatorially coordin…
Nuevas vías de depósito, nuevos proyectos: consolidación del repositorio institucional RODERIC
2017
El objetivo de este artículo es dar a conocer los nuevos proyectos del repositorio institucional de la Universitat de València, RODERIC, así como las nuevas vías de depósito de documentos de investigación. Para ello, se analizan las distintas actuaciones dentro del apartado de investigación del repositorio. En primer lugar, las centradas en el área de revistas editadas en la UV, los proyectos sobre digitalización de tesis retrospectivas y publicación de tesis corrientes, y finalmente la integración del sistema CRIS con el repositorio. Se acaba con la descripción de una serie de mejoras que se prevén están disponibles en la segunda mitad de 2013. The aim of this paper is to present new proje…
Response of pineal serotonin N-acetyltransferase activity in male guinea pigs exposed to light pulses at night.
1988
Serotonin N-acetyltransferase (NAT), which is crucial for the formation of melatonin, undergoes a typical day/night rhythm in the pineal gland with low levels during daytime and high levels at night. Short pulses of light given at night have been shown to rapidly depress NAT activity in some species, but not in others, the reasons for this difference being unclear. As diurnality and nocturnality of the experimental animals may play a role and since diurnally active animals have been little investigated in this respect, in the present study the diurnally active guinea pig was investigated. Male guinea pigs kept under a lighting regimen of LD 12:12 (lights off at 1700 hrs) were killed between…
A radiometric and petrographic approach to risk assessment at Alte Madonie Mounts region (Sicily, Italy)
2013
The main goal of this work was to assess the radiological hazard at Alte Madonie Mounts region (north-central Sicily, Italy) in response to rumours of an increase in the incidence of cancer in this area. A correlation between the natural radionuclide contents and the petrographic features of the soil and rock samples was also evaluated. A total of 41 samples of selected soils and rocks were collected, powdered, dried and sealed in 'Marinelli' beakers for 20 d prior to measurement to ensure that a radioactive equilibrium between (226)Ra and (214)Bi had been reached. A gamma-ray spectrometer was used to quantify the radioactivity concentrations. To determine (238)U and (232)Th activities, the…