Methods to Unravel Pathways of Reactive Oxygen Species in the Photodynamic Inactivation of Bacteria

Different experimental conditions can be used to detect the presence of reactive oxygen species (ROS) in the photodynamic inactivation of microorganisms. Here, we describe the effect of the media and the addition of ROS scavengers to obtain insight about the oxidative processes that take place during the photokilling of bacteria. In addition, 9,10-dimethylanthracene was used to sense the generation of singlet molecular oxygen, O2(1Δg), in microbial cells. Thus, the contribution of type I or type II pathways in the photocytotoxicity action can be rapidly detected and compared between different photosensitizers.Fil: Gsponer, Natalia Soledad. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Química Orgánica; Argentina. Universidad Nacional de Río Cuarto. Instituto para el Desarrollo Agroindustrial y de la Salud. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto para el Desarrollo Agroindustrial y de la Salud; ArgentinaFil: Durantini, Edgardo Néstor. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Química Orgánica; Argentina. Universidad Nacional de Río Cuarto. Instituto para el Desarrollo Agroindustrial y de la Salud. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto para el Desarrollo Agroindustrial y de la Salud; Argentin

The J/psi normal nuclear absorption

We present a new determination of the ratio of cross-sections (J/psi)/DY as expected for nucleus-nucleus reactions if J/psi would only be normally absorbed by nuclear matter. This anticipated behaviour is based on proton-nucleus data exclusively, and compared, as a function of centrality, with updated S-U results from experiment NA38 and with the most recent Pb-Pb results from experiment NA50

Transverse momentum dependence of charmonium suppression in Pb - Pb collisions at the CERN SPS

Charmonium suppression in Pb-Pb collisions at 158 GeV/c per nucleon is investigated in detail with the study of the transverse momentum distributions of J/psi as a function of the centrality of the collision. It is shown that the observed J/psi suppression in Pb-Pb interactions is particularly significant mainly at low transverse momentum where it strongly depends on centrality. For peripheral Pb-Pb collisions, the transverse momentum dependence of the J/psi cross section is, as a function of centrality, qualitatively similar to the dependence observed in p-A and S-U collisions. Comparing peripheral and central Pb-Pb collisions, the data show a relative suppression in the whole p(T) range although its amplitude significantly decreases with increasing p(T) and becomes almost p(T) independent for the highest p(T) values. RI Alexa, Calin/F-6345-2010; Cortese, Pietro/G-6754-2012; beole', stefania/G-9353-201

Transverse momentum dependence of charmonium suppression in Pb-Pb collisions at the CERN SPS

Charmonium suppression in Pb-Pb collisions at 158 GeV/c per nucleon is investigated in detail with the study of the transverse momentum distributions of J/psi as a function of the centrality of the collision. It is shown that the observed J/psi suppression in Pb-Pb interactions is particularly significant mainly at low transverse momentum where it strongly depends on centrality. For peripheral Pb-Pb collisions, the transverse momentum dependence of the J/psi cross section is, as a function of centrality, qualitatively similar to the dependence observed in p-A and S-U collisions. Comparing peripheral and central Pb-Pb collisions, the data show a relative suppression in the whole p(T) range although its amplitude significantly decreases with increasing p(T) and becomes almost p(T) independent for the highest p(T) values

Fission cross sections of lead projectiles in Pb-nucleus interactions at 40 and 158 GeV/c per nucleon

The fission of lead projectiles has been investigated at the CERN SPS by the NA50 experiment. For this study, a Cherenkov quartz detector was added to the standard NA50 setup to measure the charge of projectilelike fragments. The data collected on different targets at 40 and 158 GeV/c per nucleon are presented here. The contributions arising from the nuclear and the electromagnetic fission mechanism are extracted from the measured fission cross sections; the electromagnetic contribution is then compared to the Weizsacker-Williams predictions

psi ' production in Pb-Pb collisions at 158 GeV/nucleon

psi' production is studied in Pb-Pb collisions at 158 GeV/c per nucleon incident momentum. Absolute cross-sections are measured and production rates are investigated as a function of the centrality of the collision. The results are compared with those obtained for lighter colliding systems and also for the J/psi meson produced under identical conditions

Transverse momentum dependence of charmonium suppression in Pb-Pb collisions at the CERN SPS RID F-6345-2010

Charmonium suppression in Pb-Pb collisions at 158 GeV/c per nucleon is investigated in detail with the study of the transverse momentum distributions of J/psi as a function of the centrality of the collision. It is shown that the observed J/psi suppression in Pb-Pb interactions is particularly significant mainly at low transverse momentum where it strongly depends on centrality. For peripheral Pb-Pb collisions, the transverse momentum dependence of the J/psi cross section is, as a function of centrality, qualitatively similar to the dependence observed in p-A and S-U collisions. Comparing peripheral and central Pb-Pb collisions, the data show a relative suppression in the whole p(T) range although its amplitude significantly decreases with increasing p(T) and becomes almost p(T) independent for the highest p(T) values