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New experimental material is presented and discussed to assess the physical phenomena yielding to almost complete solute separation in the so-called vertical gradient packed thermal diffusion column (PTC). The separation efficiency of this experimental device has been observed by some experimenters, but no convincing theory has been established so far. It has been assumed that thermal diffusion (or Soret effect) or even thermogravitational separation (coupling between thermal convection and thermal diffusion) could provide potential explanations for the observed phenomena. The experiments that are discussed here, suggest that thermal diffusion is likely to play but a marginal role in separation, whereas a distillation process promoted by a bubble, called gas membrane distillation, seems to provide a better explanation. This statement may have important consequences for the in situ separation of natural oils and for industrial applications.

For the past ten years, the highest proton energies accelerated with high‐intensity lasers was 58 MeV, observed in 2000 at the LLNL NOVA Petawatt laser, using flat foil targets. Recently, 67.5 MeV protons were observed in experiments at the Los Alamos National Laboratory (LANL) Trident laser, using one‐fifth of the PW laser pulse energy, incident into novel conical targets. We present a focused study of new theoretical understanding of this measured enhancement from collisional Particle‐in‐Cell simulations, which shows that the hot electron temperature, number and maximum energy, responsible for the Target Normal Sheath Acceleration (TNSA) at the cone‐top, are significantly increased when the laser grazes the cone wall. This is mainly due to the extraction of electrons from the cone wall by the laser electric field, and their boost in the forward direction by the v × B term of the Lorentz force. This result is in contrast to previous predictions of optical collection and wall‐guiding of electrons in angled cones. This new wall‐grazing mechanism offers the prospect to linearly increase the hot electron temperature, and thereby the TNSA proton energy, by extending the length over which the laser interacts in a grazing fashion in suitably optimized targets. This may allow achieving much higher proton energies for interesting future applications, with smaller, lower energy laser systems that allow for a high repetition rate.

Laser‐plasma accelerated ion and electron beam sources are an emerging field with vast prospects, and promise many superior applications in a variety of fields such as hadron cancer therapy, compact radioisotope generation, table‐top nuclear physics, laboratory astrophysics, nuclear forensics, waste transmutation, Special Nuclear Material (SNM) detection, and inertial fusion energy. LANL is engaged in several projects seeking to develop compact high‐current and high‐energy ion and electron sources. We are especially interested in two specific applications: ion fast ignition/capsule perturbation and radiation oncology. Laser‐to‐beam conversion efficiencies of over 10% are needed for practical applications, and we have already shown inherent efficiencies of >5% from flat foils, on Trident using only a 5th of the intensity [1] and energy of the Nova Petawatt laser [2]. With clever target designs, like structured curved cone targets, we have also been able to achieve major ion energy gains, leading to the highest energy laser‐accelerated proton beams in the world [3]. These new target designs promise to help usher in the next generation of particle sources realizing the potential of laser‐accelerated beams.

In this work we report on a recent experiment where an energetic, well‐collimated electron beam has been observed in the laser direction following the short pulse (600 fs) high‐intensity laser interaction with ultra‐thin solid foils. These results are in contrast to the typical low‐energy divergent electrons accompanying ions in the target normal direction usually seen in solid targets. We observe the foils being preheated and expanded by ASE prior to the main pulse which makes them transparent for the laser. The experimental evidence as well as 2D particle‐in‐cell simulations suggest the excitation of a wakefield that can accelerate electrons to energies of tens of MeV.

Laser-driven particle acceleration has been under intense investigation for the last decade and is of particular interest for key applications such as medical physics, fast ignition and inertial confinement fusion. The dominant ion acceleration mechanism is known as target normal sheath acceleration (TNSA); although easy accessible it suffers from a low energy conversion efficiency. Recently reported maximum ion energies1 are in the range of a few tens of MeV, which is well below the energies needed for most applications. Recently proposed acceleration mechanisms utilize ultra-high contrast laser pulses and ultra-thin solid targets allowing for generation of ions in the GeV range from intense laser-plasma interaction. A high laser contrast suppresses pre-ionization of the solid target by any pre-pulses or laser pedestals and in theory enables acceleration beyond TNSA in regimes such as the break-out afterburner (BOA)2 or radiation pressure acceleration (RPA).

For the first time, microcin-producing strains showing inhibitory activities against enteropathogen Salmonella enteritidis were isolated from poultry intestinal contents. Among the numerous strains isolated, two strains of Escherichia coli, named J02 and J03, showing the greatest activities against S. enteritidis, were studied. Biochemical tests and purification identified the main antagonist compound produced as microcin J25. In order to evaluate the protective potential of E. coli J02 and J03 against S. enteritidis infection, the ability of these strains to inhibit growth of S. enteritidis was investigated in mixed culture. A strong antagonist activity was obtained with a preculture phase of the active strain in minimal medium before incubation with S. enteritidis. In a bioreactor experiment simulating the chicken gastric and intestinal tract environment, a mixture of the two strains E. coli J02 and J03, provided an enhanced inhibitory effect. Microcinogenic strain activities were not affected by bile, pancreatic enzymes addition, or acidic conditions. These results suggest the relevant role of microcin-producing microorganisms in microbial intestinal ecology. To conclude, this study shows that microcin J25 strains could exert a beneficial protective effect against S. enteritidis growth in situ.Key words: microcin J25, Salmonella, mixed cultures.

Authors describe three cases of agranulocytosis in patients with giant cell (temporal) arterities treated with Dapsone and corticosteroids. The culture in vitro of CFU.GM. cells of two patients, four healthy subject and two patients treated with Dapsone with out granulopenia, demonstrates no any toxic effect of Dapsone. A review of the literature finds 59 cases of agranulocytosis in patients treated with Dapsone alone or in combination with other drugs. Doses of Dapsone ranged from 25 mg to 300 mg a day. Agranulocytosis occurred between the 4th and the 12th week, more often near the 8th week. Agranulocytosis occurred suddenly without previous granulocytopenia. These facts argue for immunoallergic mechanism. This Dapsone side effect requires to restrict its use and to reserve it to serious diseases or failures of other therapeutic drugs. It needs too to keep a close eye on the patients between the 6th and 12th week.