Search results for "dron"
showing 10 items of 4363 documents
Magic triangular and tetrahedral clusters
1997
Using the methods of density functional theory and the jellium model we show that clusters with triangular [in two dimensions (2D)] or tetrahedral [in three dimensions (3D)] shapes have a strong shell structure and enhanced stability. Moreover, the shell closings correspond to the lowest magic numbers of a 2D and 3D harmonic oscillator and at the same time to the number of divalent atoms in close-packed triangles and tetrahedrons. Ab initio molecular dynamics simulations for Na and Mg clusters support the results of the jellium model.
The vibrational levels of methane obtained from analyses of high-resolution spectra
2006
International audience; Methane and its tetrahedral isotopologues are spherical-top molecules whose high-resolution rovibrational spectra can only be analyzed in detail, thanks to sophisticated symmetry-adapted tensorial models. However, the effective Hamiltonian parameters of such models do not give direct access to the positions of the vibrational sublevels. In this paper, we present a calculation of the vibrational level positions for 12CH4, 13CH4, 12CD4 and 13CD4 performed using the effective Hamiltonian parameters obtained through recent analyses. We also include the results of a re-analysis of the octad system of 12CH4 performed with a higher order of the development which slightly im…
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…
Simulations and measurements of beam loss patterns at the CERN Large Hadron Collider
2014
The CERN Large Hadron Collider (LHC) is designed to collide proton beams of unprecedented energy, in order to extend the frontiers of high-energy particle physics. During the first very successful running period in 2010-2013, the LHC was routinely storing protons at 3.5-4 TeV with a total beam energy of up to 146 MJ, and even higher stored energies are foreseen in the future. This puts extraordinary demands on the control of beam losses. An uncontrolled loss of even a tiny fraction of the beam could cause a superconducting magnet to undergo a transition into a normal-conducting state, or in the worst case cause material damage. Hence a multistage collimation system has been installed in ord…
International workshop on next generation gamma-ray source
2022
Journal of physics / G 49(1), 010502 (2022). doi:10.1088/1361-6471/ac2827
Topical anti-inflammatory activity of some Asian medicinal plants used in dermatological disorders.
2001
The topical anti-inflammatory activity of extracts from Cassia angustifolia, Rheum palmatum, Coptis chinensis, Phellodendron amurense and Scutellaria baicalensis, plants used in traditional East Asian medicine against different skin disorders, was studied. Though in different degree, all the extracts significantly inhibited the edema induced by 12-O-tetradecanoylphorbol-13-acetate (TPA), in both single or multiple application, oxazolone, and arachidonic acid (AA). None of the extracts inhibited in vitro the activity of phospholipase A(2) (PLA(2)) from Naja naja.
Lithiasic obstructive uropathy. Hydronephrosis characterization by magnetic resonance pyelography.
2004
The purpose of this study was to evaluate the role of magnetic resonance (MR) pyelography in patients affected by hydronephrosis due to ureteric stones, in order to identify a pyonephrotic condition.In the last 3 years, 315 patients, who had originally been investigated by ultrasonography, were evaluated with MR pyelography in order to define the etiology of obstruction. In 67 patients hydronephrosis was referred as caused by lithiasis.MR pyelography not only confirmed urinary tract dilatation in all patients, but also identified grade and site of obstruction, both in acute dilatation (25 patients) and in chronic obstructions (42 patients). In 7 patients, MR pyelography documented pyonephro…
Surgery-triggered and non surgery-triggered Bisphosphonate-related Osteonecrosis of the Jaws (BRONJ): A retrospective analysis of 567 cases in an Ita…
2011
Invasive local procedures are often reported in clinical history of patients suffering from Bisphosphonates-Related Osteonecrosis of the Jaws (BRONJ) but over 40% of spontaneous forms have been also described in literature. We compared age, gender, underlying bone disorders, bisphosphonate therapy, clinical features and surgical outcome of 205 cases (36.2%) of BRONJ non surgery-triggered (group 1) with 362 (63.8%) cases of surgery-triggered forms (group 2). Differences between group 1 and 2 were analysed using Mann-Whitney U and χ2 tests. Statistical analysis was performed using STATA 8. Zoledronate was the most used type of bisphosphonate (63.4% versus 69.0%) and the mandible was the most …
Pathological mandibular fracture after simple molar extraction in a patient with osteogenesis imperfecta treated with alendronate
2009
Osteogenesis imperfecta (OI), is a heterogeneous group of inherited disorders of connective tissue characterized by bone fragility. Patients with this disease frequently suffer fractures, over 80% of the extremities due to the more intensive mechanical load. Fractures of the facial bones occur very infrequently. Several studies have proved that bisphosphonate therapy may be effective in reducing fracture risk in OI patients. We report here an unusual case of pathological mandibular fracture following simple molar extraction in an adult patient with OI type I and oral alendronic acid treatment. Extraction was atraumatical and without bone removal . Fracture was treated by internal fixation b…