AlN, GaN, and InN were irradiated at room temperature with monatomic swift heavy ions and high-energy fullerenes. Ion track formation was studied using transmission electron microscopy in both plane ...view and cross-sectional modes. A full experimental description of ion track formation in these compounds is presented. AlN shows a remarkable resistance towards track formation; InN is the most sensitive and shows partial decomposition, likely into N
2
and metallic clusters; the overlapping of the amorphous tracks in GaN does not give an amorphous layer because of a track-induced recrystallization. We discuss the application of the inelastic thermal spike model, which allows good and simple predictions of track radii in oxides, to the studied III-nitrides, and in general to semiconductors.
The ^{12}C+^{12}C fusion reaction plays a critical role in the evolution of massive stars and also strongly impacts various explosive astrophysical scenarios. The presence of resonances in this ...reaction at energies around and below the Coulomb barrier makes it impossible to carry out a simple extrapolation down to the Gamow window-the energy regime relevant to carbon burning in massive stars. The ^{12}C+^{12}C system forms a unique laboratory for challenging the contemporary picture of deep sub-barrier fusion (possible sub-barrier hindrance) and its interplay with nuclear structure (sub-barrier resonances). Here, we show that direct measurements of the ^{12}C+^{12}C fusion cross section may be made into the Gamow window using an advanced particle-gamma coincidence technique. The sensitivity of this technique effectively removes ambiguities in existing measurements made with gamma ray or charged-particle detection alone. The present cross-section data span over 8 orders of magnitude and support the fusion-hindrance model at deep sub-barrier energies.
The 2015 Paediatric European Network for Treatment of AIDS (PENTA) guidelines provide practical recommendations on the management of HIV‐1 infection in children in Europe and are an update to those ...published in 2009. Aims of treatment have progressed significantly over the last decade, moving far beyond limitation of short‐term morbidity and mortality to optimizing health status for adult life and minimizing the impact of chronic HIV infection on immune system development and health in general. Additionally, there is a greater need for increased awareness and minimization of long‐term drug toxicity. The main updates to the previous guidelines include: an increase in the number of indications for antiretroviral therapy (ART) at all ages (higher CD4 thresholds for consideration of ART initiation and additional clinical indications), revised guidance on first‐ and second‐line ART recommendations, including more recently available drug classes, expanded guidance on management of coinfections (including tuberculosis, hepatitis B and hepatitis C) and additional emphasis on the needs of adolescents as they approach transition to adult services. There is a new section on the current ART ‘pipeline’ of drug development, a comprehensive summary table of currently recommended ART with dosing recommendations. Differences between PENTA and current US and World Health Organization guidelines are highlighted and explained.
The search for the standard model Higgs boson at the Large Hadron Collider (LHC) started more than two decades ago. Much innovation was required and diverse challenges had to be overcome during the ...conception and construction of the LHC and its experiments. The ATLAS and CMS Collaboration experiments at the LHC have discovered a heavy boson that could complete the standard model of particle physics.
A beam tagging hodoscope prototype made of squared 1 mm2 fibers arranged in two perpendicular planes and coupled to multi-anode photomultipliers has been studied using 65 MeV proton as well as 95 ...MeV/u 12C beams at various intensities. This hodoscope successfully provided 2D images of proton beams with a detection efficiency larger than 98% with logical OR condition between the two fiber planes. The detection efficiency with a coincidence between the two planes is close to 75% for beam intensities up to ∼1 MHz. Moreover, the timing resolution is around 1.8 ns FWHM. Overall, the performances show that such a technology is viable for beam monitoring during hadrontherapy.
Aims. The aim of this work is to furnish branching ratios (BRs) to the kinetic databases used in astrochemistry such as the KInetic Database for Astrochemistry (KIDA). This concerns CH y(+) ...$_y^{(+)}$ y (+) species (y = 2–4) excited by cosmic rays, electrons and photons, or the intermediate excited complexes CH y(+) $_y^{(+)}$ y (+) resulting from a chemical reaction. Methods. The full set of fragmentation branching ratios following CH y(+) $_y^{+}$ y + (y = 2,4) of constant velocity (250 keV uma−1) colliding with He atoms has been measured with the multidetector AGAT. Kinetic energy distributions of neutral fragments produced in each dissociation channel have been also measured. With these experimental inputs, and theoretical dissociation energies, semiempirical breakdown curves (BDCs) have been constructed. Results. Prediction of BRs with the present BDCs is found to agree with available BR measurements for electronic dissociative recombination, collision with fast electron and photodissociation. Dependence of BRs with the various UV fields relevant to interstellar medium and planetary atmospheres is predicted.
Background. Severely immunocompromised individuals are highly susceptible to Candida infection of the esophagus. This randomized, double-blind study assessed the dose-response relationship of the new ...echinocandin antifungal, micafungin, compared with that of standard fluconazole treatment. Methods. A total of 245 patients (age, ⩾18 years) with a prior diagnosis of acquired immunodeficiency syndrome/human immunodeficiency virus (HIV) infection and esophageal candidiasis, confirmed by endoscopy and culture, were randomized to receive micafungin (50, 100, or 150 mg per day) or fluconazole (200 mg per day). Both agents were administered once per day by a 1-h intravenous infusion for 14–21 days. The primary efficacy end point was endoscopic cure rate, defined as endoscopy grade of 0 at the end of therapy. Results. The endoscopic cure rate (grade 0) was dose-dependent with 50, 100, and 150 mg of micafungin per day at 68.8%, 77.4%, and 89.8%, respectively. Symptoms improved or resolved rapidly (3–7 days of treatment in the majority of patients). The endoscopic cure rate for 100 and 150 mg of micafungin per day (83.5%) was comparable to that for 200 mg of fluconazole per day (86.7%; 95% confidence interval for the difference in endoscopic cure rate, -14.0% to 7.7%). The overall safety and tolerability was acceptable, with no important differences between micafungin (all doses) and fluconazole. Conclusions. The dose-response findings demonstrate a greater efficacy with micafungin at 100 and 150 mg per day than at 50 mg per day. This study also indicates that the efficacy of micafungin (at dosages of 100 and 150 mg per day) was comparable to that of fluconazole, suggesting that micafungin represents a valuable new treatment option for esophageal candidiasis in HIV-positive patients.
Short chained triesters of glycerol and citric acid were systematically investigated as novel dual-functional dispersants and plasticisers for use in ceramic processing. Additional systematic studies ...on a series of diesters having structural similarities with the citrate and glycerol triesters were performed to further assess the significance of specific functional groups for the stabilisation of suspensions.
The overall purpose of this work consists in simplifying the formulation for ceramic processing slurries while at the same time limiting the environmental impact and toxicity. The use of multifunctional additives reduces the risk of unwanted interactions between different components. Additionally, the possible use of one additive in more than one role opens the opportunity for an overall reduction in the number and amount of chemicals and therefore reduction of costs and risks.
For the citrate ester candidates, different alkoxy groups were tested as well as the acetylation on the hydroxyl group. The glycerol esters differed by the length of the carboxylic chain.
Especially triethyl and tributyl citrate are proposed as promising dual-functional additives for ceramic processing. Specifically, for triethyl citrate the dual-function was finally demonstrated by producing a dense piece of 8YSZ through tape casting and subsequent sintering.
Strontium isotopes facilitate the study of human paleogeography and have widened the scope of archaeological enquiries on mobility. We present an approach based on strontium isotopes (87Sr/86Sr) to ...study the mobility of hunter–gatherer societies from northwestern Patagonia (Neuquén, Argentina). The analysis is developed on the basis of a macro‐regional geological framework that guides the sampling and interpretation of results. We also present results for fauna to begin building a landscape of bioavailable strontium to be utilized in the interpretation of results from human samples. These first results conform to general expectations and show the most radiogenic 87Sr/86Sr values for the oldest geological provinces, while low values are recorded for recent substrates. Additionally, we provide results for human samples from archaeological sites spanning the last 4000 years, a period during which a number of important socio‐demographic changes occurred. The results in human samples indicate overall isotopic fidelity to the values recorded in the local geology, suggesting a relatively restricted spatial scale of mobility during the late Holocene. This discussion is situated in a biogeographic research framework assessing topographic variation and landscape seasonality, and contributes toward understanding the movements of people, flow of material objects, and circulation of information in the Patagonian Andes.
Graphite targets have been irradiated at 90 K and 300 K with 850 MeV and 6 GeV lead ions and with 20–30 MeV fullerene cluster ions in a large range of fluences. Damage creation was studied both by ...transmission electron microscopy and Raman spectroscopy. The very strong energy density deposited in electronic processes generates a highly excited region around the projectile path. The relaxation of the deposited energy via hydrodynamic expansion and shock-wave propagation leads to the formation of small defective graphitic domains and of nanocrystalline diamond particles.
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