Canonical Description of Strangeness Enhancement from p-A to Pb-Pb Collisions

We consider the production of strange particles in Pb-Pb and p-A collisions at the SPS energy reported by the WA97 experiment. We show that the observed enhancement of strange baryon and antibaryon yields in Pb-Pb collisions relative to p-Be and p-Pb can be explained in terms of the statistical model formulated in canonical ensemble with respect to strangeness conservation. The importance and the role of strangeness under saturation is also discussed.Comment: 8 pages, 3 figure

Lung density in the trajectory path — a strong indicator of patients sustaining a pneumothorax during CT-guided lung biopsy

Introduction: The purpose is to evaluate the prognostic significance of lung parenchymal density during percutaneous coaxial cutting needle lung biopsy (PNLB). Materials and methods: Retrospective analysis of 179 consecutive patients (106 males, 73 females; mean age 59.16 ± 16.34 years) undergoing PNLB was included. Mean lobar parenchymal lung density, mean densities anterior to the lesion and posterior to the chest wall in the needle trajectory path were measured in HU. Lesion location and needle trajectory were also measured. Fisher’s exact test and Chi-square test were conducted to analyze the categorical variables. ANOVA test was done to examine continuous and normally distributed variables. Statistical significance was considered when p < 0.05. Results: Mean lobar parenchymal lung density (p < 0.05) and mean parenchymal lung density relative to the needle trajectory path were below -800 HU in patients who sustained a pneumothorax. Increase in the number of pleural passes was significantly associated with the risk of patients having pneumothorax (p < 0.05). The mean distance from the skin to the lesion and needle trajectory angle were not statistically different among patients with and without pneumothorax (p > 0.05). Conclusion: Lobar parenchymal density and lung parenchymal density anterior to the lesion and posterior to the chest wall in the needle trajectory path could be used as predicting parameters in patients undergoing PNLB who sustained a pneumothorax. These findings can help interventional radiologist further assess risk of pneumothorax when preforming such procedure

Quark-Gluon Plasma Fireball

Lattice-QCD results provide an opportunity to model, and extrapolate to finite baryon density, the properties of the quark-gluon plasma (QGP). Upon fixing the scale of the thermal coupling constant and vacuum energy to the lattice data, the properties of resulting QGP equations of state (EoS) are developed. We show that the physical properties of the dense matter fireball formed in heavy ion collision experiments at CERN-SPS are well described by the QGP-EoS we presented. We also estimate the properties of the fireball formed in early stages of nuclear collision, and argue that QGP formation must be expected down to 40A GeV in central Pb--Pb interactions.Comment: 10 pages, 9 postscript figures, 1 table, uses revtex, V3: introduced difference between n_f and n_s; fireball restframe energy corrected, references added. Publisched version in press Phys. Rev.

HYDRODYNAMIQUE DU PLASMA DE QUARKS ET DE GLUONS DANS LES COLLISIONS D'IONS LOURDS (EVOLUTION DE L'ETRANGETE)

ORSAY-PARIS 11-BU Sciences (914712101) / SudocSudocFranceF

Molecular Study of Ultrasound-Triggered Release of Fluorescein from Liposomes

International audienceSeveral investigations have suggested that ultrasound triggers the release of drugs encapsulated into liposomes at acoustic pressures low enough to avoid cavitation or high hyperthermia. However, the mechanism leading to this triggered release as well as the adequate composition of the liposome membrane remain unknown. Here, we investigate the ultrasound triggered release of fluorescein disodium salt encapsulated into liposomes made of 1,2-dioleoyl-sn-glycero-3-phosphocholi (DOPC) or 1,2-distearoylphosphatidylethanolamie (DSPC) lipids with various concentrations of cholesterol (from 0 to 44 mol%). The passive release of encapsulated fluorescein was first characterized. It was observed to be higher when the membrane is in a fluid phase and increased with temperature but decreased upon addition of cholesterol. Next, the release of fluorescein was measured at 1 different acoustic frequencies (0.8, 1.1, 3.3 MHz) and peak-to-peak pressures (0, 2, 2.5, 5, 8 MPa). Measurements were performed at temperatures where DOPC and DSPC liposomes were respectively in the fluid or gel phase. We found that the release rate did not depend on the ultrasound frequency. For DOPC liposomes, the ultrasoundtriggered release of fluorescein decreased with increasing concentration of cholesterol in liposomes, while the behavior was more complex for DSPC liposomes. Overall, the triggered release from DSPC liposomes was up to ten times less than DOPC liposomes. Molecular dynamics simulations performed on a pure DOPC membrane showed that a membrane experiences, under a directional pressure of ±2.4 MPa, various changes in properties such as the area per lipid (APL). An increase in APL was notably observed when the simulation box was laterally stretched or perpendicularly compressed, which was accompanied by an increase in the number of water molecules crossing the membrane. This suggests that ultrasound most probably enhances the diffusion of encapsulated molecules at small acoustic pressures by increasing the distance between lipids

A facile preparation of CuS-BSA nanocomposite as enzyme mimics: Application for selective and sensitive sensing of Cr(VI) ions

International audienc

Lung Density in the Trajectory Path—A Strong Indicator of Patients Sustaining a Pneumothorax during CT-Guided Lung Biopsy

Introduction: The purpose is to evaluate the prognostic significance of lung parenchymal density during percutaneous coaxial cutting needle lung biopsy (PNLB). Materials and methods: Retrospective analysis of 179 consecutive patients (106 males, 73 females; mean age 59.16 ± 16.34 years) undergoing PNLB was included. Mean lobar parenchymal lung density, mean densities anterior to the lesion and posterior to the chest wall in the needle trajectory path were measured in HU. Lesion location and needle trajectory were also measured. Fisher’s exact test and Chi-square test were conducted to analyze the categorical variables. ANOVA test was done to examine continuous and normally distributed variables. Statistical significance was considered when p < 0.05. Results: Mean lobar parenchymal lung density (p < 0.05) and mean parenchymal lung density relative to the needle trajectory path were below -800 HU in patients who sustained a pneumothorax. Increase in the number of pleural passes was significantly associated with the risk of patients having pneumothorax (p < 0.05). The mean distance from the skin to the lesion and needle trajectory angle were not statistically different among patients with and without pneumothorax (p > 0.05). Conclusion: Lobar parenchymal density and lung parenchymal density anterior to the lesion and posterior to the chest wall in the needle trajectory path could be used as predicting parameters in patients undergoing PNLB who sustained a pneumothorax. These findings can help interventional radiologist further assess risk of pneumothorax when preforming such procedure