2 research outputs found
Lattice Boltzmann simulations of soft matter systems
This article concerns numerical simulations of the dynamics of particles
immersed in a continuum solvent. As prototypical systems, we consider colloidal
dispersions of spherical particles and solutions of uncharged polymers. After a
brief explanation of the concept of hydrodynamic interactions, we give a
general overview over the various simulation methods that have been developed
to cope with the resulting computational problems. We then focus on the
approach we have developed, which couples a system of particles to a lattice
Boltzmann model representing the solvent degrees of freedom. The standard D3Q19
lattice Boltzmann model is derived and explained in depth, followed by a
detailed discussion of complementary methods for the coupling of solvent and
solute. Colloidal dispersions are best described in terms of extended particles
with appropriate boundary conditions at the surfaces, while particles with
internal degrees of freedom are easier to simulate as an arrangement of mass
points with frictional coupling to the solvent. In both cases, particular care
has been taken to simulate thermal fluctuations in a consistent way. The
usefulness of this methodology is illustrated by studies from our own research,
where the dynamics of colloidal and polymeric systems has been investigated in
both equilibrium and nonequilibrium situations.Comment: Review article, submitted to Advances in Polymer Science. 16 figures,
76 page
Infections by carbapenem-resistant Klebsiella pneumoniae in SCT recipients: A nationwide retrospective survey from Italy
Infections by carbapenem-resistant Klebsiella pneumoniae (CRKp) represent a challenging problem after SCT. A retrospective survey (January 2010 to July 2013) involving 52 Italian centers was performed to assess the epidemiology and the prognostic factors of CRKp infections in auto- and allo-SCT. Cases of CRKp infection were reported in 53.4% of centers. CRKp infections were documented in 25 auto-SCTs and 87 allo-SCTs, with an incidence of 0.4% (from 0.1% in 2010 to 0.7% in 2013) and 2% (from 0.4% in 2010 to 2.9% in 2013), respectively. A CRKp colonization documented before or after transplant was followed by an infection in 25.8% of auto-SCT and 39.2% of allo-SCT patients. The infection-related mortality rates were 16% and 64.4%, respectively. A pre-transplant CRKp infection (hazard ratio (HR) 0.33, 95% confidence intervals (CIs) 0.15-0.74; P=0.007) and a not CRKp-targeted first-line treatment (HR 2.67, 95% CI 1.43-4.99; P=0.002) were independent factors associated with an increased mortality in allo-SCT patients who developed a CRKp infection. Our study shows challenging findings of CRKp infections in SCT patients in Italy particularly after allo-SCT. The detection of carriers and the definition of early therapeutic strategies represent critical aspects of the management of CRKp infections after SCT