603 research outputs found

    Experimental measurements of water molecule binding energies for the second and third solvation shells of [Ca(H₂O)n]2+ complexes

    Get PDF
    Further understanding of the biological role of the Ca2+ ion in an aqueous environment requires quantitative measurements of both the short and long range interactions experienced by the ion in an aqueous medium. Here we present experimental measurements of binding energies for water molecules occupying the second and, quite possibly, the third solvation shell surrounding a central Ca2+ ion in [Ca(H2O)n]2+ complexes. Results for these large, previously inaccessible, complexes have come from the application of finite heat bath theory to kinetic energy measurements following unimolecular decay. Even at n = 20 the results show water molecules to be more strongly bound to Ca2+ than would be expected just from the presence of an extended network of hydrogen bonds. For n > 10, there is very good agreement between the experimental binding energies and recently published DFT calculations. Comparisons are made with similar data recorded for [Ca(NH3)n]2+ and [Ca(CH3OH)n]2+ complexes

    Target BACRIM: Blurring fact and fiction to create an interactive documentary game

    Get PDF
    Target: BACRIM is an immersive and interactive documentary game that exposes the atrocities of Colombia’s paramilitary forces in one of its most violent regions. The producers combine both non - fiction and fiction to create a game that places the user at the heart of the story. Through this docufiction , which is anchored in augmented reality, the user or participant experiences danger first - hand. For the user, this violence is a game. For the people who live in this region, it is a reality. Target: BACRIM wants to blur tha t distinction. We therefore create a world, where fiction and non - fiction are interrelated, where genres merge and where individual disciplines escape the shackles of tradition to converge and create an interactive documentary that places user experience a t its cor

    Asymptomatic Primary Fallopian Tube Cancer: An Unusual Cause of Axillary Lymphadenopathy

    Get PDF
    Primary Fallopian tube malignancy is considered a rare disease and is often mistaken histologically and clinically for ovarian cancer. The etiology is poorly understood, and it typically presents at an advanced disease stage, as symptoms are often absent in the initial period. As a result, primary fallopian tube cancer is generally associated with a poor prognosis. We present the case of a 45-year-old female who presents with a 5-day history of left axillary swelling and a normal breast examination. Mammogram and biopsy of a lesion in the left breast revealed a fibroadenoma but no other abnormalities. Initial sampling of the axillary node was suspicious for a primary breast malignancy, but histology of the excised node refuted this. PET-CT showed an area of high uptake in the right pelvis, and a laparoscopy identified a tumor of the left fallopian tube which was subsequently excised and confirmed as a serous adenocarcinoma

    Stabilities of nanohydrated thymine radical cations: insights from multiphoton ionization experiments and ab initio calculations

    Get PDF
    Multi-photon ionization experiments have been carried out on thymine-water clusters in the gas phase. Metastable H2O loss from T+(H2O)n was observed at n ≄ 3 only. Ab initio quantum-chemical calculations of a large range of optimized T+(H2O)n conformers have been performed up to n = 4, enabling binding energies of water to be derived. These decrease smoothly with n, consistent with the general trend of increasing metastable H2O loss in the experimental data. The lowest-energy conformers of T+(H2O)3 and T+(H2O)4 feature intermolecular bonding via charge-dipole interactions, in contrast with the purely hydrogen-bonded neutrals. We found no evidence for a closed hydration shell at n = 4, also contrasting with studies of neutral clusters

    Ultra-fast silicon detectors

    Get PDF
    Abstract We propose to develop a fast, thin silicon sensor with gain capable to concurrently measure with high precision the space (∌10 ÎŒm) and time (∌10 ps) coordinates of a particle. This will open up new application of silicon detector systems in many fields. Our analysis of detector properties indicates that it is possible to improve the timing characteristics of silicon-based tracking sensors, which already have sufficient position resolution, to achieve four-dimensional high-precision measurements. The basic sensor characteristics and the expected performance are listed, the wide field of applications are mentioned and the required R&D topics are discussed

    Treatment of localised resectable neuroblastoma. Results of the LNESG1 study by the SIOP Europe Neuroblastoma Group

    Get PDF
    Main objective of this study was to confirm that surgery alone is an effective and safe treatment for localised resectable neuroblastoma except stage 2 with amplified MYCN gene (MYCNA). Of 427 eligible stages 1–2 patients, 411 had normal MYCN and 16 had MYCNA. Of the 288 stage 1 patients with normal MYCN, 1 died of complications and 16 relapsed, 2 of whom died; 5-year relapse-free survival (RFS) and overall survival (OS) rates were 94.3% (95% confidence interval (CI): 91.6–97) and 98.9% (95% CI: 97.7–100), respectively. Of the 123 stage 2 patients with normal MYCN, 1 died of sepsis and 22 relapsed, 8 of whom died (RFS 82.8%, 95% CI: 76.2–89.5; OS 93.2%, 95% CI: 88.7–97.8). In stage 2, OS and RFS were worse for patients with elevated LDH and unfavourable histopathology. Of 16 children with MYCNA, 7 were stage 1 (5 relapses and 4 deaths) and 9 were stage 2 (3 relapses and 2 deaths) patients. In conclusion, surgery alone yielded excellent OS for both stage 1 and 2 neuroblastoma without MYCNA, although stage 2 patients with unfavourable histopathology and elevated LDH suffered a high number of relapses. Both stage 1 and 2 patients with MYCNA were at greater risk of relapse

    Systematic study related to the role of initial impurities and irradiation rates in the formation and evolution of complex defects in silicon for detectors in HEP experiments

    Full text link
    The influence of oxygen and carbon impurities on the concentrations of defects in silicon for detector uses, in complex fields of radiation, characteristic to high energy physics experiments, is investigated in the frame of the quantitative phenomenological model developed previously by the authors and extended in the present paper. Continuous irradiation conditions are considered, simulating realistically the environments for these experiments. The generation rate of primary defects is calculated starting from the projectile - silicon interaction and from the recoil energy redistribution in the lattice. The mechanisms of formation of complex defects are explicitly analysed. Vacancy-interstitial annihilation, interstitial and vacancy migration to sinks, divacancy, vacancy- and interstitial-impurity complex formation and decomposition are considered. Oxygen and carbon impurities present in silicon could monitor the concentration of all stable defects, due to their interaction with vacancies and interstitials. Their role in the mechanisms of formation and decomposition of the following stable defects: V_2, VO, V_2O, C_i, C_iO_i, C_iC_s and VP, is studied. The model predictions cover a generation primary rate of defects between 10^2 pairs/cm3/s and 10^{11} pairs/cm3/s, and could be a useful clue in obtaining harder materials for detectors for space missions, at the new generation of accelerators, as, e.g. LHC, Super-LHC and Eloisatron, or for industrial applications.Comment: 15 pages, work in the frame of CERN RD50 Collaboration, submitted to Physica Script
    • 

    corecore