Search results for " function"
showing 10 items of 9395 documents
Reduced regional systolic function evolved compacted segments in noncompaction
2010
Abstract In a recent report about noncompaction Nemes et al. reported that systolic left ventricular (LV) dysfunction assessed using the wall motion score during 2D echocardiography in noncompaction is not confined to noncompacted LV segments. These results confirmed some published reports of our group. Recently we analyzed a population of 238 patients affected by noncompaction, and demonstrated that the number of noncompacted segment is uncorrelated with the degree of systolic dysfunction. It is an attractive hypothesis that the systolic dysfunction could be depend on the fibrosis of the left ventricle, itself a consequence of microcirculatory dysfunction, which has been confirmed by repor…
Syntheses of Trifluoroethylated N-Heterocycles from Vinyl Azides and Togni’s Reagent Involving 1,n-Hydrogen-Atom Transfer Reactions
2020
2,2,2-Trifluoroethyl-substituted 3-oxazolines, 3-thiazolines, and 5,6-dihydro-2H-1,3-oxazines have been obtained by reacting substituted vinyl azides with a combination of Togni’s reagent and substoichiometric amounts of iron(II) chloride. The results of density functional theory calculations support the proposed mechanism involving 1,n-hydrogen-atom transfer reactions. peerReviewed
Chalcogen‐Bonding Interactions in Telluroether Heterocycles [Te(CH2)m]n (n=1-4; m=3-7)
2020
The Te…Te secondary bonding interactions (SBI) in solid heterocyclic telluroethers were explored by preparing and structurally characterizing a series of [Te(CH2)m]n (n = 1‐4; m = 3‐7) species. The SBIs in 1,7‐Te2(CH2)10, 1,8‐Te2(CH2)12, 1,5,9‐Te3(CH2)9, 1,8,15‐Te3(CH2)18, 1,7,13,19‐Te4(CH2)20, 1,8,15,22‐Te4(CH2)24, and 1,9,17,25‐Te4(CH2)28 led to the tubular packing of the molecules, as has been observed previously for related thio‐ and selenoether rings. The nature of the intermolecular interactions was explored by solid‐state PBE0‐D3/pob‐TZVP calculations involving periodic boundary conditions. The packing of molecules in 1,7,13,19‐Te4(CH2)20, 1,8,15,22‐Te4(CH2)24, and 1,9,17,25‐Te4(CH2)…
KIELELLINEN ERITYISVAIKEUS – EI PELKÄSTÄÄN KIELELLISTEN TAITOJEN ONGELMA
2016
Kielellisen erityisvaikeuden ajatellaan olevan ensisijaisesti kielellisten taitojen ongelma. On kuitenkin todennäköistä, että kielelliseen erityisvaikeuteen liittyy myös ei-kielellisiä vaikeuksia. Tämän artikkelin tavoitteena on luoda katsaus eksekutiivisiin toimintoihin ja prosessointinopeuteen osana kielellistä erityisvaikeutta. Tutkimusten perusteella näyttää siltä, että kielelliseen erityisvaikeuteen liittyy kognitiiviseen joustavuuteen, inhibitioon, työmuistiin, tarkkaavuuteen sekä prosessointinopeuteen liittyviä vaikeuksia ainakin osalla kielihäiriöistä lapsista. Kielellisen erityisvaikeuden kliinisessä diagnostiikassa ja kuntoutuksessa on syytä huomioida myös ei-kielelliset vaikeudet…
Multipactor radiation analysis within a waveguide region based on a frequency-domain representation of the dynamics of charged particles
2009
[EN] A technique for the accurate computation of the electromagnetic fields radiated by a charged particle moving within a parallel-plate waveguide is presented. Based on a transformation of the time-varying current density of the particle into a time-harmonic current density, this technique allows the evaluation of the radiated electromagnetic fields both in the frequency and time domains, as well as in the near- and far-field regions. For this purpose, several accelerated versions of the parallel-plate Green's function in the frequency domain have been considered. The theory has been successfully applied to the multipactor discharge occurring within a two metal-plates region. The proposed…
β and γ bands in N = 88, 90, and 92 isotones investigated with a five-dimensional collective Hamiltonian based on covariant density functional theory…
2019
A comprehensive systematic study is made for the collective β and γ bands in even-even isotopes with neutron numbers N=88 to 92 and proton numbers Z=62(Sm) to 70 (Yb). Data, including excitation energies, B(E0) and B(E2) values, and branching ratios from previously published experiments are collated with new data presented for the first time in this study. The experimental data are compared to calculations using a five-dimensional collective Hamiltonian (5DCH) based on the covariant density functional theory (CDFT). A realistic potential in the quadrupole shape parameters V(β,γ) is determined from potential energy surfaces (PES) calculated using the CDFT. The parameters of the 5DCH are fixe…
Gas phase behavior of radical cations of perfluoroalkyl-1,2,4-triazines: an experimental and theoretical study
2009
Electron ionization mass spectrometry and low-energy collision-induced decomposition reactions occurring in a tridimensional ion trap, together with density functional theory (DFT) calculations on neutrals, even- and odd-electron cations, have been used to study the gas-phase ion chemistry of a series of perfluoroalkyl-1,2,4-triazines. Loss of oxygen, due to thermal degradation occurring before ionization, likely involving the hydroxylamino group, has been observed. Compounds having a carbonyl group at position 6 of the triazine ring fragment in the source by elimination of NO followed by HF or CO. The decomposition pathways occurring due to CID experiments have shown interesting features d…
Inclusive photoproduction of bottom quarks for low and medium p T in the general-mass variable-flavour-number scheme
2016
We present predictions for b-quark production in photoprodcution and compare with experimental data from HERA. Our theoretical predictions are obtained at next-to-leading-order in the general-mass variable-flavor-number scheme, an approach which takes into account the finite mass of the b quarks. We use realistic evolved nonperturbative fragmentation functions obtained from fits to e+e- data. We find in general good agreement of data with both the GM-VFNS and the FFNS calculations, while the more precise ZEUS data seem to prefer the GM-VFNS predictions.
Structure of superheavy nuclei along decay chains of element 115
2014
[Introduction] A recent high-resolution α , X -ray, and γ -ray coincidence-spectroscopy experiment offered the first glimpse of excitation schemes of isotopes along α -decay chains of Z = 115. To understand these observations and to make predictions about shell structure of superheavy nuclei below 288 115, we employ two complementary mean-field models: the self-consistent Skyrme energy density functional approach and the macroscopic-microscopic Nilsson model. We discuss the spectroscopic information carried by the new data. In particular, candidates for the experimentally observed E 1 transitions in 276 Mt are proposed. We find that the presence and nature of low-energy E 1 transitions in w…
Electromagnetic wave propagation in non-homogeneous waveguides
2015
We investigate an electromagnetic waveguide, having several cylindrical ends. The waveguide is assumed to be empty and to have a perfectly conductive boundary. We study the electromagnetic field, excited in the waveguide in the presence of charges and currents. The field can be described as a solution of the stationary Maxwell system with conductive boundary conditions and “intrinsic” radiation conditions at infinity. We prove the problem to be well-posed. Electromagnetic waves propagation in the waveguide can be described by means of a scattering matrix. We introduce such a matrix for all values of the spectral parameter k in the waveguide continuous spectrum and study its properties. Moreove…