Quasiprojectile breakup and isospin equilibration at Fermi energies: an indication of longer projectile-target contact times?

An investigation of the quasiprojectile breakup channel in semiperipheral and peripheral collisions of $^{58,64}$Ni+$^{58,64}$Ni at 32 and 52 MeV/nucleon is presented. Data have been acquired in the first experimental campaign of the INDRA-FAZIA apparatus in GANIL. The effect of isospin diffusion between projectile and target in the two asymmetric reactions has been highlighted by means of the isospin transport ratio technique, exploiting the neutron-to-proton ratio of the quasiprojectile reconstructed from the two breakup fragments. We found evidence that, for the same reaction centrality, a higher degree of relaxation of the initial isospin imbalance is achieved in the breakup channel with respect to the more populated binary output, possibly indicating the indirect selection of specific dynamical features. We have proposed an interpretation based on different average projectile-target contact times related to the two exit channels under investigation, with a longer interaction for the breakup channel. The time information has been extracted from AMD simulations of the studied systems coupled to GEMINI++: the model calculations support the hypothesis hereby presented

Is prolonged infusion of piperacillin/tazobactam and meropenem in critically ill patients associated with improved pharmacokinetic/pharmacodynamic and patient outcomes? An observation from the Defining Antibiotic Levels in Intensive care unit patients (DALI) cohort

Objectives:We utilized the database of the Defining Antibiotic Levels in Intensive care unit patients (DALI) study to statistically compare the pharmacokinetic/pharmacodynamic and clinical outcomes between prolonged-infusion and intermittent-bolus dosing of piperacillin/tazobactam and meropenem in critically ill patients using inclusion criteria similar to those used in previous prospective studies.Methods: This was a post hoc analysis of a prospective, multicentre pharmacokinetic point-prevalence study (DALI), which recruited a large cohort of critically ill patients from 68 ICUs across 10 countries.Results: Of the 211 patients receiving piperacillin/tazobactam and meropenem in the DALI study, 182 met inclusion criteria. Overall, 89.0% (162/182) of patients achieved the most conservative target of 50% fT(> MIC) (time over which unbound or free drug concentration remains above the MIC). Decreasing creatinine clearance and the use of prolonged infusion significantly increased the PTA for most pharmacokinetic/pharmacodynamic targets. In the subgroup of patients who had respiratory infection, patients receiving beta-lactams via prolonged infusion demonstrated significantly better 30 day survival when compared with intermittent-bolus patients [86.2% (25/29) versus 56.7% (17/30); P=0.012]. Additionally, in patients with a SOFA score of >= 9, administration by prolonged infusion compared with intermittent-bolus dosing demonstrated significantly better clinical cure [73.3% (11/15) versus 35.0% (7/20); P=0.035] and survival rates [73.3% (11/15) versus 25.0% (5/20); P=0.025].Conclusions: Analysis of this large dataset has provided additional data on the niche benefits of administration of piperacillin/tazobactam and meropenem by prolonged infusion in critically ill patients, particularly for patients with respiratory infections

Year in review in Intensive Care Medicine 2009: I. Pneumonia and infections, sepsis, outcome, acute renal failure and acid base, nutrition and glycaemic control

Journal ArticleReviewSCOPUS: re.jinfo:eu-repo/semantics/publishe

Control parameters transition during deploying operations of a space flexible structure via multi-body approach

The need to model very complex spacecraft has induced many researchers to develop different methodologies for their study, depending on the type of analysis to be performed. In the ease of structural analysis a classical finite element approach is used to describe in detail each component. In the case of flight mechanics a simple rigid spacecraft can be used for studying guidance, navigation and control laws. On the contrary for studying deploying mechanisms it is necessary to define models of joints and actuators. The necessity to reduce time and cost of the development of new space platforms requires the integration of these different design models and processes. In recent years new methodologies, based on the so-called multibody approach, have been introduced for modeling mechanical systems. Complex space structures are divided into sub-elements (rigid or flexible) connected to each other through joints. With this approach, a very detailed multibody model of a spacecraft can be easily adapted to face different disciplines. Unfortunately, when dealing with elastic bodies the number of degrees of freedom (DOFs) drastically increases. The approach here suggested to keep the number of DOF low is to employ a hybrid approach where a limited number of bodies is chosen, depending on the values of their inertial and elastic properties. In the present work a very large flexible satellite is modeled via multibody technique. In particular the deployable solar arrays and the bus are represented with only three elastic bodies. The deployment phase of the solar panels is simulated through a time sequence of panels models with different geometries. For each configuration the inertial and modal properties are evaluated, and eventually these parameters are interpolated in order to determine their values when a continuous movement of the panels is simulated. On account of the geometry variation we can observe not only a variation on the values of the natural frequencies, but also an exchange on the ranking of the relevant modal shapes and hence on the relevant modal participation factors. A re-ordering of the modal shapes is mandatory before doing any interpolation. A robust and easy to implement re-ordering criteria is presented in the paper together with a number of numerical simulations showing that the proposed hybrid approach can be considered as a valid alternative to simulate a deployable structure with a reduced number of elements and hence of a reduced computational cost. Copyright © (2012) by the International Astronautical Federation