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Objective Meropenem is a β-lactam, carbapenem antibacterial agent with antimicrobial activity against gram-negative, gram-positive and anaerobic micro-organisms and is important in the empirical treatment of serious infections in Intensive Care Unit (ICU) patients. Multi-drug resistant gram-negative organisms, coupled with scarcity of new antibiotic classes, forced healthcare community to optimize the therapeutic potential of available antibiotics. Our aim is to investigate the effect of continuous infusion of meropenem against bolus administration, as indicated by a composite outcome of reducing death and emergence of extensive or pan drug-resistant pathogens in a population of ICU patients. Design Double blind, double dummy, multicenter randomized controlled trial (1:1 allocation ratio). Setting Tertiary and University hospitals. Interventions 600 ICU patients with sepsis or septic shock, needing by clinical judgment antibiotic therapy with meropenem, will be randomized to receive a continuous infusion of meropenem 3 g/24 h or an equal dose divided into three daily boluses (i.e. 1g q8h). Measurements The primary endpoint will be a composite outcome of reducing death and emergence of extensive or pan drug-resistant pathogens. Secondary endpoints will be death from any cause at day 90, antibiotic-free days at day 28, ICU-free days at day 28, cumulative SOFA-free (Sequential Organ Failure Assessment) score from randomization to day 28 and the two, separate, components of the primary endpoint. We expect a primary outcome reduction from 52 to 40% in the continuous infusion group. Conclusions The trial will provide evidence for choosing intermittent or continuous infusion of meropenem for critically ill patients with multi-drug resistant gram-negative infections.

Biological experiments in space and ongoing human space missions devoted to the solar system exploration require significant advancements in the radiation environment monitoring systems. Radiation hazard has to be continuously monitored and the biological damage should be evaluated within short time. In this paper, we review the use of polycrystalline diamond films as dosimeters for space applications. The charge trapped into deep intra-gap defect levels during radiation exposure, and released during a high-temperature thermal scan to give thermally stimulated current (TSC), has been integrated as a function of time to evaluate the absorbed dose. TSC results have been proved to give correct evaluation of the dose absorbed during the space mission, assessing the capabilities of synthetic diamond and TSC read-out system as a proper dosimetry technique for space applications. The capability of diamond films to detect low doses has been demonstrated down to the mGys range. The results of the application of these dosimeters in low Earth orbit space missions are described.

A polycrystalline Chemical Vapour Deposited (pCVD) diamond film has been processed to implement a bidimensional dosimeter for applications in clinical radiotherapy. The detector, with an area of 2.5×2.5 cm 2 and a thickness of 300 μ m , has been equipped with a matrix of electrical contacts (12×12 pixels) on the upper surface. The matrix of pixels has been electrically characterized in dark showing uniformity and very low leakage current. This study demonstrates that when applied bias is in the range 0–5 V, the pCVD diamond film provides very accurate measurement of dose and dose-rates under clinical 62 MeV proton beam, conventional 6–10 MeV photon beams, and Intensity Modulated Radiotherapy (IMRT) beams.

The Colour and Stereo Surface Imaging System (CaSSIS) is a high-resolution camera for the ESA ExoMars Trace Gas Orbiter mission launched in March 2016. CaSSIS is capable of acquiring color stereo images of features on the surface of Mars to better understand the processes related to trace gas emission. The optical configuration of CaSSIS is based on a three-mirror anastigmatic off-axis imager with a relay mirror; to attain telecentric features and to maintain compact the design, the relay mirror has power. The University of Bern had the task of detector integration and characterization of CaSSIS focal plane. An OGSE (Optical Ground Support Equipment) characterization facility was set up for this purpose. A pinhole, imaged through an off-axis paraboloidal mirror, is used to produce a collimated beam. In this work, the procedures to align the OGSE and to link together the positions of each optical element will be presented. A global Reference System (RS) has been defined using an optical cube placed on the optical bench (OB) and linked to gravity through its X component; this global RS is used to correlate the alignment of the optical components. The main steps to characterize the position of the object to that of the CaSSIS focal plane have been repeated to guide and to verify the operations performed during the alignment procedures. A calculation system has been designed to work on the optical setup and on the detector simultaneously, and to compute online the new position of the focus plane with respect to the detector. Final results will be shown and discussed.

Biological experiments in space and ongoing human space missions devoted to the solar system exploration require significant advancements in the radiation environment monitoring systems. Radiation hazard has to be continuously monitored and the evaluation of the biological damage suffered should be calculated within short time. In this paper we demonstrate the feasibility of using polycrystalline diamond films as dosimeters for space applications. The charge trapped into deep intra-gap defect levels during radiation exposure, and released during a high-temperature thermal scan to give thermally stimulated current (TSC), has been integrated as a function of time to evaluate the absorbed dose. The capability of diamond films to detect low doses has been demonstrated down to the mGys range. First application of these dosimeters in a real twelve-day, low Earth orbit, space mission has been carried out. TSC results have been proved to give correct evaluation of the dose absorbed during the space mission, assessing the capabilities of synthetic diamond and TSC read-out system as a proper dosimetry technique for space applications.

Irradiation of chestnuts has recently been considered as an alternative treatment to fumigation to reduce the considerable amount of the product normally lost during post-harvest period. The treatment is allowed in countries such as Korea and, in view of a possible extension to European countries, to permit the legal controls as required by the directive 1999/2/EC [ European Parliament and Council Directive, 1999 /2/EC, on the approximation of the laws of the Member States concerning foods and food ingredients treated with ionising radiation. Official Journal of the European Communities. L 66/16 of 13.3.1999] and meet consumer consensus, reliable methods for detecting irradiated chestnuts have to be proposed. The aim of the present work was to test the efficacy of the European Standard EN 13751, EN 1788, EN 1787 and EN 13708 in detecting irradiated chestnuts. For this purpose, six sets of “Montella” chestnuts, a typical Italian variety recognized as a PGI (protected geographical indication), non-irradiated and irradiated at different doses in the 0.1–1 kGy range, were analysed by thermoluminescence (TL), photo-stimulated luminescence (PSL) (screening and calibrated PSL) and ESR techniques. PSL and TL analysis results revealed the low luminescence sensitivity of the chestnuts. Nevertheless, PSL screening data were in the intermediate band above the negative threshold (at all doses except at the lowest one) and TL analysis led to correct positive classifications even at the lowest dose tested (0.15 Gy). On the contrary, no radio-induced ESR signal could be registered with the irradiated samples of chestnut shell or pulp.

Modern radiotherapy treatment techniques, such as intensity Modulated Radiation Therapy (IMRT) and protontherapy, require detectors with specific features, usually not available in conventional dosimeters. IMRT dose measurements, for instance, must face non-uniform beam fluences as well as a time-varying dose rate. Two-dimensional detectors present a great interest for dosimetry in beams with steep dose gradients, but they must satisfy a number of requirements and, in particular, they must exhibit high spatial resolution. With the aim of developing a dosimetric system adequate for 2D pre-treatment dose verifications, we designed a modular dosimetric device based on a monolithic silicon-segmented module. State and results of this work in progress are described in this article. The first 441 pixels, 6.29×6.29 cm 2 silicon module has been produced by ion implantation on a 50 μm thick p-type epitaxial layer. This sensor has been connected to a discrete readout electronics performing current integration, and has been tested with satisfactory results. In the final configuration, nine silicon modules will be assembled together to cover an area close to 20×20 cm 2 with 3969 channels. In this case, the readout electronics will be based on an ASIC capable to read 64 channels by performing current-to-frequency conversion.

A simple compact temperature sensor and microheater in a wide temperature range has been developed, realizing a laser-patterned resistive structure on the surface of a synthetic polycrystalline diamond plate. Imaging and spectroscopy techniques used to investigate morphology, structure, and composition of the pattern showed that it incorporates different nondiamond carbon phases. Transport experiments revealed the semiconducting behavior of this microresistor. Thermal power measurements versus temperature are presented. A possible application of this device that may easily match compact experimental layouts avoiding both thermal anchoring offset and mechanical stress between sample and sensor is discussed. The patterned structure undergoes testing as a microthermometer, providing fast response and excellent stability versus time. It exhibits a good sensitivity that coupled to an easy calibration procedure minimizes errors and guarantees high accuracy. Plot of temperature versus input power of the resistive patterned line used as microheater shows a linear behavior in an extended temperature range.

In this paper we report about the BIOKIS payload: a multidisciplinary set of experiments and measurements in the fields of Biology (4) and Dosimetry (3) performed in microgravity. BIOKIS took advantage of the last STS-134 Endeavour mission and engineering state of the art in Space Life Science. The BIOKIS payload is compact, efficient, and capable to host experiments with different samples and science disciplines. Moreover, the time overlap of biological experiments and dosimetry measurements will produce more insightful information.

PRESS-MAG-O is a new instrument under commission at the Laboratori Nazionali di Frascati of the Istituto Nazionale di Fisica Nucleare (INFN) designed to investigate materials under extreme conditions. The instrument, once completed, will allow combining high harmonic AC magnetic susceptibility measurements and magneto-optic experiments on samples under high pressures (HP), with a variable DC magnetic field in a wide temperature range. The system is designed to work at SINBAD, the IR synchrotron radiation beamline operational since 2001 at DA phi NE (Double Annular phi-factory for Nice Experiments), the storage ring of the Laboratori Nazionali di Frascati of the INFN. HP will be applied up to about 20GPa to samples inside a Cu-Be diamond anvil cell designed to allow concurrent FTIR experiments and high harmonic AC susceptibility measurements in a DC magnetic field up to 8T and in a wide temperature range.

The emergence of the citric acid cycle is one of the most remarkable occurrences with regard to understanding the origin and evolution of metabolic pathways. Although the chemical steps of the cycle are preserved intact throughout nature, diverse organisms make wide use of its chemistry, and in some cases organisms use only a selected portion of the cycle. However, the origins of this cycle would have arisen in the more primitive anaerobic organism or even back in the proto-metabolism, which likely arose spontaneously under favorable prebiotic chemical conditions. In this context, we report that UV irradiation of formamide in the presence of titanium dioxide afforded 6 of the 11 carboxylic acid intermediates of the reductive version of the citric acid cycle. Since this cycle is the central metabolic pathway of contemporary biology, this report highlights the role of photochemical processes in the origin of the metabolic apparatus. Key Words: Catalysis—UV radiation—Metabolism—Origin of life—Prebio...

Synchrotron radiation (SR) is a fundamental tool for X-ray research. In particular, X-ray absorption spectroscopy (XAS) accesses information as electronic properties, local structure or chemical-physical state in condensed-matter studies. Ionization chambers (ICs) are the most widely used XAS detectors for transmission measurements because of their reliability, high linearity and good stability. Recently, solid-state detectors have been considered and Si p-i-n has been applied to high fluxes (10{sup 11} ph/s), where the linearity of ICs is no longer guaranteed. Silicon photodiodes exhibit an extremely linear response in at least 5 decades but show diffraction peaks. Diamond is an ideal substrate to produce radiation-hard, low dark current (

Oxygen in the interstellar medium is seen in the gas phase, in ices (incorporated in H{sub 2}O, CO, and CO{sub 2}), and in grains such as (Mg{sub x} Fe{sub 1-x} )SiO{sub 3} or (Mg{sub x} Fe{sub 1-x} ){sub 2}SiO{sub 4}, 0 < x < 1. In this investigation, we study the diffusion of oxygen atoms and the formation of oxygen molecules and ozone on the surface of an amorphous silicate film. We find that ozone is formed at low temperature (

In the interstellar medium (ISM), an important channel of water formation is the reaction of atoms on the surface of dust grains. Here, we report on a laboratory study of the formation of water via the O+D reaction network. While prior studies were done on ices, as appropriate to the formation of water in dense clouds, we explored how water formation occurs on bare surfaces, i.e., in conditions mimicking the transition from diffuse to dense clouds (Av ~ 1-5). Reaction products were detected during deposition and afterward when the sample is brought to a high temperature. We quantified the formation of water and intermediary products, such as D2O2, over a range of surface temperatures (15-25 K). The detection of OD on the surface signals the importance of this reactant in the overall scheme of water formation in the ISM.