37 research outputs found
The local magnetic moments and hyperfine magnetic fields in disordered metal-metalloid alloys
The local magnetic moments and hyperfine magnetic fields (HFF) in the ordered
alloys Fe_{15}Sn and Fe_{15}Si are calculated with the first-principles
full-potential linear augmented plane wave (FP LAPW) method. The results are
compared with the experimental data on Fe-M (M=Si, Sn) disordered alloys at
small metalloid concentration. The relaxation of the lattice around the
impurity and its influence on the quantities under consideration are studied.
The mechanism of the local magnetic moment formation is described. It is proved
that the main distinction between these alloys is connected with the different
lattice parameters. Three contributions to the HFF are discussed: the
contributions of the core and valence electron polarization to the
Fermi-contact part, and the contibution from the orbital magnetic moment.Comment: 3 pages, 3 figures, submitted to Phys. Rev.
Density-functional calculation of ionization energies of current-carrying atomic states
Current-density-functional theory is used to calculate ionization energies of
current-carrying atomic states. A perturbative approximation to full
current-density-functional theory is implemented for the first time, and found
to be numerically feasible. Different parametrizations for the
current-dependence of the density functional are critically compared. Orbital
currents in open-shell atoms turn out to produce a small shift in the
ionization energies. We find that modern density functionals have reached an
accuracy at which small current-related terms appearing in open-shell
configurations are not negligible anymore compared to the remaining difference
to experiment.Comment: 7 pages, 2 tables, accepted by Phys. Rev.
Multicentre international trial of laparoscopic lavage for Hinchey III acute diverticulitis (LLO Study)
Background: Laparoscopic lavage was proposed in the 1990s to treat purulent peritonitis in patients with perforated acute diverticulitis. Prospective randomized trials had mixed results. The aim of this study was to determine the success rate of laparoscopic lavage in sepsis control and to identify a group of patients that could potentially benefit from this treatment. Methods: This retrospective multicentre international study included consecutive patients from 24 centres who underwent laparoscopic lavage from 2005 to 2015. Results: A total of 404 patients were included, 231 of whom had Hinchey III acute diverticulitis. Sepsis control was achieved in 172 patients (74·5 per cent), and was associated with lower Mannheim Peritonitis Index score and ASA grade, no evidence of free perforation, absence of extensive adhesiolysis and previous episodes of diverticulitis. The operation was immediately converted to open surgery in 19 patients. Among 212 patients who underwent laparoscopic lavage, the morbidity rate was 33·0 per cent; the reoperation rate was 13·7 per cent and the 30-day mortality rate 1·9 per cent. Twenty-one patients required readmission for early complications, of whom 11 underwent further surgery and one died. Of the 172 patients discharged uneventfully after laparoscopic lavage, a recurrent episode of acute diverticulitis was registered in 46 (26·7 per cent), at a mean of 11 (range 2–108) months. Relapse was associated with younger age, female sex and previous episodes of acute diverticulitis. Conclusion: Laparoscopic lavage showed a high rate of successful sepsis control in selected patients with perforated Hinchey III acute diverticulitis affected by peritonitis, with low rates of operative mortality, reoperation and stoma formation
Current density functional theory of spontaneously magnetised solids
The first application of current density functional theory
(CDFT) to spontaneously magnetised solids is presented.
We show that non-relativistic CDFT without spin-orbit
coupling
does not lead to finite orbital currents.
In accordance with experiment, an enhancement of the spin-orbit–induced
orbital magnetic moment is found for the
ferromagnets Fe and Co, while for Ni only a minor change
was found compared to a plain calculation
done within spin density functional theory (SDFT)
Response of apple proliferation-resistant Malus sieboldii hybrids to multiple infections with latent apple viruses
Apple proliferation (AP) is the most important phytoplasma-associated disease affecting apple in Europe. The failure in controlling this disease by standard means strongly increased the importance of adopting resistant genotypes. About 6000 seedlings were obtained from a breeding programme crossing M. sieboldii, donor of resistance to AP, with standard apple rootstocks (M9 mainly) as donor of agronomic value. Resistance screening showed that the trait was inherited to the progenies and trials are in progress to test the agronomic value of these genotypes. In an additional trial, the response of AP-resistant genotypes to a superinfection with different
latent apple viruses was investigated. For this, M. sieboldii-derived first and second generation hybrids were analysed. In summer, three repetitions for each genotype were inoculated with apple chlorotic leaf spot (ACLSV), apple stem grooving (ASGV)
and apple stem pitting (ASPV) virus. The two following springs after infection, the presence of the viruses was assessed by ELISA
test and virus-specific symptom recording on young leaves. In parallel, the reaction of the plants to infections with Trentino strains of ‘Candidatus Phytoplasma mali’ was evaluated. AP-susceptible Malus x domestica genotypes were considered as controls. The
results confirmed an incidence of the viral infections on Malus sieboldii as it was reported in the past. However, the M. sieboldii hybrids showed a high variability of response ranging from no viral symptoms to severe symptoms. Nevertheless, highly phytoplasma-resistant genotypes which showed no presence of viral superinfections could be identified in these experiments