Organic electrochemistry: Synthesis and functionalization of β-lactams in the twenty-first century

Organic electrochemistry is a technique that allows for the heterogeneous redox reactions avoiding both the use of stoichiometric amounts of redox reagents and the resulting formation of stoichiometric by-pro- ducts. In fact, the redox reagent in these reactions is the electron, which is naturally eco-friendly and pro- duces no side compounds. It is therefore quite obvious that electrochemistry can be classified as a “green” tech- nology. The use of this methodology in the synthesis of β-lactams is not a novelty, but the growing interest in this class of biologically active compounds, due to the dis- covery of new fields of application (after a moment of decrease in interest due to antibiotic resistance) has been a stimulus for the search for more efficient electro- chemical ways to synthesize and transform β-lactams. Thus, this review deals with the twenty-first-century applications of electroorganic technique to the chemistry of β-lactams, by analyzing first the syntheses classified by the type of reactions (cyclization, cycloaddition, etc.) and then by manipulating the β-lactam structure, using it as a synthon. Lastly, the importance of this technique is demonstrated by a study of a pilot plant scale reduction of a cephalosporanic acid derivative to a commercially important antibiotic

Release of Palladium from Biomechanical Prostheses in Body Fluids Can Induce or Support PD-Specific IFNγ T Cell Responses and the Clinical Setting of a Palladium Hypersensitivity:

The increased use of Palladium (Pd) for biomedical applications, which has more than doubled in the last ten years, appears to be associated with an increased frequency of adverse reactions to Pd. The aim of this study is to investigate the relationship between the implant of a biomechanical apparatus containing Pd and the setting of a hypersensitivity to Pd by determining the levels of the metal released in biological fluids, assessing the effects of Pd on peripheral blood mononuclear cell (PBMC) cytokine production and exploring the clinical setting of skin sensitization. Of a total of 3,093 subjects examined in 2006, sensitization to Pd alone or in association with nickel (Ni) was observed in 1.6% and 13.03% of the individuals, respectively. Of these, a group of six subjects positive to Pd and negative to Ni at patch testing were selected on the basis of the oral clinical symptoms in order to measure both the levels of Pd in biological fluids and the degradation of the dental prostheses. Specific Pd measurements were carried out on salivary fluid, urine and serum samples by High Resolution Inductively Coupled Plasma-Mass Spectrometry. In addition, the degradation of the dental prostheses was assessed by both a "leaching test" and an analysis of the micro morphology of orthodontic prostheses. The induction of IFN-γ production by Pd was assessed in PBMC by the ELISpot assay. Skin sensitization to Pd was evaluated by patch testing and clinical examination. Ten healthy subjects were comparatively tested as controls. We found a specific induction of an IFN-γ response by Pd in PBMC collected from all the subjects positive to Pd at patch testing. On the contrary, control subjects did not show any response to Pd as assessed by IFN-γ ELISpot assay or by skin testing. Remarkably, the levels of Pd in all biological samples (saliva, sera, urine) were significantly higher in Pd-sensitized patients than in those collected from controls, reaching the highest concentrations in the urine. The leaching studies gave additional evidence that the dental appliances can release measurable levels of Pd in saliva. Oral clinical symptoms in patients with Pd dental prostheses were associated with measurable levels of Pd in the biological fluids, the induction of Pd-specific IFN-γ responses in PBMC and the clinical evidence of skin sensitization to Pd. These data suggest that dental appliances may represent an active source of Pd in the body, and this, in turn, can favour the clinical setting of a hypersensitivity to this metal

Neutron irradiation test on ATLAS MDT chambers

Abstract The Monitored Drift Tubes (MDT) chambers of the ATLAS muon spectrometer are crucial for the identification of high-momentum final-state muons, which represent very promising and robust signatures of physics at the LHC. They will operate in a high rate and high background environment and therefore their performances should not significantly degrade for the whole ATLAS data taking. The maximum expected total flux, mainly consisting of neutrons and photons in the MeV range, is of the order of 5 kHz/cm 2 for the barrel MDTs, while at SLHC, with machine working at higher luminosity, fluxes can be 10 times higher. To test detector robustness, a MDT test chamber was exposed to intensive neutron irradiation at the TAPIRO ENEA-Casaccia Research Center facility

Growth, electronic and electrical characterization of Ge-Rich Ge-Sb-Te alloy

In this study, we deposit a Ge-rich Ge-Sb-Te alloy by physical vapor deposition (PVD) in the amorphous phase on silicon substrates. We study in-situ, by X-ray and ultraviolet photoemission spectroscopies (XPS and UPS), the electronic properties and carefully ascertain the alloy composition to be GST 29 20 28. Subsequently, Raman spectroscopy is employed to corroborate the results from the photoemission study. X-ray diffraction is used upon annealing to study the crystallization of such an alloy and identify the effects of phase separation and segregation of crystalline Ge with the formation of grains along the [111] direction, as expected for such Ge-rich Ge-Sb-Te alloys. In addition, we report on the electrical characterization of single memory cells containing the Ge-rich Ge-Sb-Te alloy, including I-V characteristic curves, programming curves, and SET and RESET operation performance, as well as upon annealing temperature. A fair alignment of the electrical parameters with the current state-of-the-art of conventional (GeTe)n-(Sb2Te3)m alloys, deposited by PVD, is found, but with enhanced thermal stability, which allows for data retention up to 230 °C

XIPE: the X-ray Imaging Polarimetry Explorer

X-ray polarimetry, sometimes alone, and sometimes coupled to spectral and temporal variability measurements and to imaging, allows a wealth of physical phenomena in astrophysics to be studied. X-ray polarimetry investigates the acceleration process, for example, including those typical of magnetic reconnection in solar flares, but also emission in the strong magnetic fields of neutron stars and white dwarfs. It detects scattering in asymmetric structures such as accretion disks and columns, and in the so-called molecular torus and ionization cones. In addition, it allows fundamental physics in regimes of gravity and of magnetic field intensity not accessible to experiments on the Earth to be probed. Finally, models that describe fundamental interactions (e.g. quantum gravity and the extension of the Standard Model) can be tested. We describe in this paper the X-ray Imaging Polarimetry Explorer (XIPE), proposed in June 2012 to the first ESA call for a small mission with a launch in 2017 but not selected. XIPE is composed of two out of the three existing JET-X telescopes with two Gas Pixel Detectors (GPD) filled with a He-DME mixture at their focus and two additional GPDs filled with pressurized Ar-DME facing the sun. The Minimum Detectable Polarization is 14 % at 1 mCrab in 10E5 s (2-10 keV) and 0.6 % for an X10 class flare. The Half Energy Width, measured at PANTER X-ray test facility (MPE, Germany) with JET-X optics is 24 arcsec. XIPE takes advantage of a low-earth equatorial orbit with Malindi as down-link station and of a Mission Operation Center (MOC) at INPE (Brazil).Comment: 49 pages, 14 figures, 6 tables. Paper published in Experimental Astronomy http://link.springer.com/journal/1068

Technical Design Report - TDR CYGNO-04/INITIUM

The aim of this Technical Design Report is to illustrate the technological choices foreseen to be implemented in the construction of the CYGNO-04 demonstrator, motivate them against the experiment physics goals of CYGNO-30 and demonstrate the financial sustainability of the project. CYGNO-04 represents PHASE 1 of the long term CYGNO roadmap, towards the development of large high precision tracking gaseous Time Projection Chamber (TPC) for directional Dark Matter searches and solar neutrino spectroscopy. The CYGNO project1 peculiarities reside in the optical readout of the light produced during the amplification of the primary ionization electrons in a stack of triple Gas Electron Multipliers (GEMs), thanks to the nice scintillation properties of the chosen He:CF4 gas mixture. To this aim, CYGNO is exploiting the fast progress in commercial scientific Active Pixel Sensors (APS) development for highly performing sCMOS cameras, whose high granularity and sensitivity allow to significantly boost tracking, improve particle identification and lower the energy threshold. The X-Y track project obtained from the reconstruction of the sCMOS images is combined with a PMT measurement to obtain a full 3D track reconstruction. In addition, several synergic R&Ds based on the CYGNO experimental approach are under development in the CYGNO collaboration (see Sec 2) to further enhance the light yield by means of electro luminescence after the amplification stage, to improve the tracking performances by exploiting negative ion drift operation within the INITIUM ERC Consolidator Grant, and to boost the sensitivity to O(GeV) Dark Matter masses by employing hydrogen rich target towards the development of PHASE 2 (see Sec. 1.2). While still under optimization and subject to possible significant improvements, the CYGNO experimental approach performances and capabilities demonstrated so far with prototypes allow to foresee the development of an O(30) m3 experiment by 2026 for a cost of O(10) MEUROs. A CYGNO-30 experiment would be able to give a significant contribution to the search and study of Dark Matter with masses below 10 GeV/c2 for both SI and SD coupling. In case of a Dark Matter observation claim by other experiments, the information provided by a directional detector such as CYGNO would be fundamental to positively confirm the galactic origin of the allegedly detected Dark Matter signal. CYGNO-30 could furthermore provide the first directional measurement of solar neutrinos from the pp chain, possibly extending to lower energies the Borexino measurement2. In order to reach this goal, the CYGNO project is proceeding through a staged approach. The PHASE 0 50 L detector (LIME, recently installed underground LNGS) will validate the full performances of the optical readout via APS commercial cameras and PMTs and the Montecarlo simulation of the expected backgrounds. The full CYGNO-04 demonstrator will be realized with all the technological and material choices foreseen for CYGNO-30, to demonstrate the scalability of the experimental approach and the potentialities of the large PHASE 2 detector to reach the expected physics goals. The first PHASE 1 design anticipated a 1 m3 active volume detector with two back-to-back TPCs with a central cathode and 500 mm drift length. Each 1 m2 readout area would have been composed by 9 + 9 readout modules having the LIME PHASE 0 dimensions and layout. Time (end of INITIUM project by March 2025) and current space availability at underground LNGS (only Hall F) forced the rescaling of the PHASE 1 active volume and design to a 0.4 m3, hence CYGNO-04. CYGNO-04 will keep the back-to-back double TPC layout with 500 mm drift length each, but with an 800 x 500 mm2 readout area covered by a 2 + 2 modules based on LIME design. The reduction of the detector volume has no impact on the technological objectives of PHASE 1, since the modular design with central cathode, detector materials and shieldings and auxiliary systems are independent of the total volume. The physics reach (which is a byproduct of PHASE 1 and NOT an explicit goal) will be only very partially reduced (less than a factor 2 overall) since a smaller detector volume implies also a reduced background from internal materials radioactivity. In addition, the cost reduction of CYGNO-04 of about 1⁄3 with respect to CYGNO-1 illustrated in the CDR effectively makes the overall project more financially sustainable (see CBS in the last section). In summary this document will explain: the physical motivation of the CYGNO project and the technical motivations of the downscale of the PHASE 1 to CYGNO-04, 400 liters of active volume, with respect to the demonstrator presented in the CDR; the results of R&D and the Montecarlo expectations for PHASE 0; the technical choices, procedures and the executive drawings of CYGNO-04 in the Hall F of the LNGS; safety evaluations and the interference/request to the LNGS services; Project management, WBS/WBC, WP, GANTT, ec

Epidemiological patterns of asbestos exposure and spatial clusters of incident cases of malignant mesothelioma from the Italian national registry

Abstract BACKGROUND: Previous ecological spatial studies of malignant mesothelioma cases, mostly based on mortality data, lack reliable data on individual exposure to asbestos, thus failing to assess the contribution of different occupational and environmental sources in the determination of risk excess in specific areas. This study aims to identify territorial clusters of malignant mesothelioma through a Bayesian spatial analysis and to characterize them by the integrated use of asbestos exposure information retrieved from the Italian national mesothelioma registry (ReNaM). METHODS: In the period 1993 to 2008, 15,322 incident cases of all-site malignant mesothelioma were recorded and 11,852 occupational, residential and familial histories were obtained by individual interviews. Observed cases were assigned to the municipality of residence at the time of diagnosis and compared to those expected based on the age-specific rates of the respective geographical area. A spatial cluster analysis was performed for each area applying a Bayesian hierarchical model. Information about modalities and economic sectors of asbestos exposure was analyzed for each cluster. RESULTS: Thirty-two clusters of malignant mesothelioma were identified and characterized using the exposure data. Asbestos cement manufacturing industries and shipbuilding and repair facilities represented the main sources of asbestos exposure, but a major contribution to asbestos exposure was also provided by sectors with no direct use of asbestos, such as non-asbestos textile industries, metal engineering and construction. A high proportion of cases with environmental exposure was found in clusters where asbestos cement plants were located or a natural source of asbestos (or asbestos-like) fibers was identifiable. Differences in type and sources of exposure can also explain the varying percentage of cases occurring in women among clusters. CONCLUSIONS: Our study demonstrates shared exposure patterns in territorial clusters of malignant mesothelioma due to single or multiple industrial sources, with major implications for public health policies, health surveillance, compensation procedures and site remediation programs

X-ray polarimetry reveals the magnetic field topology on sub-parsec scales in Tycho's supernova remnant

Supernova remnants are commonly considered to produce most of the Galactic cosmic rays via diffusive shock acceleration. However, many questions about the physical conditions at shock fronts, such as the magnetic-field morphology close to the particle acceleration sites, remain open. Here we report the detection of a localized polarization signal from some synchrotron X-ray emitting regions of Tycho's supernova remnant made by the Imaging X-ray Polarimetry Explorer. The derived polarization degree of the X-ray synchrotron emission is 9+/-2% averaged over the whole remnant, and 12+/-2% at the rim, higher than the 7-8% polarization value observed in the radio band. In the west region the polarization degree is 23+/-4%. The X-ray polarization degree in Tycho is higher than for Cassiopeia A, suggesting a more ordered magnetic-field or a larger maximum turbulence scale. The measured tangential polarization direction corresponds to a radial magnetic field, and is consistent with that observed in the radio band. These results are compatible with the expectation of turbulence produced by an anisotropic cascade of a radial magnetic-field near the shock, where we derive a magnetic-field amplification factor of 3.4+/-0.3. The fact that this value is significantly smaller than those expected from acceleration models is indicative of highly anisotropic magnetic-field turbulence, or that the emitting electrons either favor regions of lower turbulence, or accumulate close to where the magnetic-field orientation is preferentially radially oriented due to hydrodynamical instabilities.Comment: 31 pages, 7 figures, 3 tables. Accepted for publication in ApJ. Revised versio