495 research outputs found
The structure of the NO-sensing domain of the transcription factor DNR from Pseudomonas aeruginosa
Supersymmetric quenched complexity in the Sherrington-Kirkpatrick model
By using the BRST supersymmetry we compute the quenched complexity of the TAP
states in the SK model. We prove that the BRST complexity is equal to the
Legendre transform of the static free energy with respect to the largest
replica symmetry breaking point of its overlap matrix
Interface Energy in the Edwards-Anderson model
We numerically investigate the spin glass energy interface problem in three
dimensions. We analyze the energy cost of changing the overlap from -1 to +1 at
one boundary of two coupled systems (in the other boundary the overlap is kept
fixed to +1). We implement a parallel tempering algorithm that simulate finite
temperature systems and work with both cubic lattices and parallelepiped with
fixed aspect ratio. We find results consistent with a lower critical dimension
. The results show a good agreement with the mean field theory
predictions.Comment: 5 pages; 7 figures; corrected typos; to appear in JS
Main restrictions in the synthesis of new superheavy elements: quasifission or/and fusion-fission
The synthesis of superheavy elements stimulates the effort to study the
peculiarities of the complete fusion with massive nuclei and to improve
theoretical models in order to extract knowledge about reaction mechanism in
heavy ion collisions at low energies. We compare the theoretical results of the
compound nucleus (CN) formation and evaporation residue (ER) cross sections
obtained for the Ca+Cm and Fe+Th reactions
leading to the formation of the isotopes A=296 and A=290, respectively, of the
new superheavy element Lv (Z=116). The ER cross sections, which can be measured
directly, are determined by the complete fusion and survival probabilities of
the heated and rotating compound nucleus. That probabilities can not be
measured unambiguously but the knowledge about them is important to study the
formation mechanism of the observed products. For this aim, the
Ca+Cf and Ni+Th reactions have been considered
too. The use of the mass values of superheavy nuclei calculated in the
framework of the macroscopic-microscopic model by Warsaw group leads to smaller
ER cross section for all of the reactions (excluding the Ni+Th
reaction) in comparison with the case of using the masses calculated by Peter
M\"oller {\it et al}.Comment: 26 pages and 15 figures. arXiv admin note: text overlap with
arXiv:1109.201
Intraoperative Redosing of Cefazolin and Risk for Surgical Site Infection in Cardiac Surgery
Intraoperative redosing of prophylactic antibiotics is recommended for prolonged surgical procedures, although its efficacy has not been assessed. We retrospectively compared the risk of surgical site infections in 1,548 patients who underwent cardiac surgery lasting >240 min after preoperative administration of cefazolin prophylaxis. The overall risk of surgical site infection was similar among patients with (43 [9.4%] of 459) and without (101 [9.3%] of 1,089) intraoperative redosing (odds ratio [OR] 1.01, 95% confidence interval [CI] 0.70-1.47). However, redosing was beneficial in procedures lasting >400 min: infection occurred in 14 (7.7%) of 182 patients with redosing and in 32 (16.0%) of 200 patients without (adjusted OR 0.44, 95% CI 0.23-0.86). Intraoperative redosing of cefazolin was associated with a 16% reduction in the overall risk for surgical site infection after cardiac surgery, including procedures lasting <240 min
A phase-separation perspective on dynamic heterogeneities in glass-forming liquids
We study dynamic heterogeneities in a model glass-former whose overlap with a
reference configuration is constrained to a fixed value. The system
phase-separates into regions of small and large overlap, so that dynamical
correlations remain strong even for asymptotic times. We calculate an
appropriate thermodynamic potential and find evidence of a Maxwell's
construction consistent with a spinodal decomposition of two phases. Our
results suggest that dynamic heterogeneities are the expression of an ephemeral
phase-separating regime ruled by a finite surface tension
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