Biomimetic sulfide oxidation by the means of immobilized Fe(III)-5,10,15,20-tetrakis(pentafluorophenyl)porphin under mild experimental conditions

This paper describes the oxidation of inorganic sulfide to sulfate, minimizing the formation of elemental sulfur. The described catalytic reaction uses dilute hydrogen peroxide at nearly neutral pH values in the presence of a bioinspired, heterogenized, and commercial ferriporphin. A substantial increase of the percentage of sulfide converted to sulfate is obtained in comparison with the yields obtained when working with hydrogen peroxide alone. The biomimetic catalyst also proved to be a much more efficient catalyst than horseradish peroxidase. Accordingly, it could be suitable for large-scale applications. Further studies are in progress to drive sulfate yields up to nearly quantitative

Zero degree measurements of 12C fragmentation at 95 MeV/nucleon on thin targets

During therapeutic treatments using ions such as carbon, nuclear interactions between the incident ions and nuclei present in organic tissues may occur, leading to the attenuation of the incident beam intensity and to the production of secondary light charged particles. As the biological dose deposited in the tumor and the surrounding healthy tissues depends on the beam composition, an accurate knowledge of the fragmentation processes is thus essential. In particular, the nuclear interaction models have to be validated using experimental double differential cross sections which are still very scarce. An experiment was realized in 2011 at GANIL to obtain these cross sections for a 95 MeV/nucleon carbon beam on different thin targets for angles raging from 4 to 43{\deg} . In order to complete these data, a new experiment was performed on September 2013 at GANIL to measure the fragmentation cross section at zero degree for a 95 MeV/nucleon carbon beam on thin targets. In this work, the experimental setup will be described, the analysis method detailed and the results presented

Two-particle interference of electron pairs on a molecular level

We investigate the photo-doubleionization of $H_2$ molecules with 400 eV photons. We find that the emitted electrons do not show any sign of two-center interference fringes in their angular emission distributions if considered separately. In contrast, the quasi-particle consisting of both electrons (i.e. the "dielectron") does. The work highlights the fact that non-local effects are embedded everywhere in nature where many-particle processes are involved

Pseudospectral Calculation of the Wavefunction of Helium and the Negative Hydrogen Ion

We study the numerical solution of the non-relativistic Schr\"{o}dinger equation for two-electron atoms in ground and excited S-states using pseudospectral (PS) methods of calculation. The calculation achieves convergence rates for the energy, Cauchy error in the wavefunction, and variance in local energy that are exponentially fast for all practical purposes. The method requires three separate subdomains to handle the wavefunction's cusp-like behavior near the two-particle coalescences. The use of three subdomains is essential to maintaining exponential convergence. A comparison of several different treatments of the cusps and the semi-infinite domain suggest that the simplest prescription is sufficient. For many purposes it proves unnecessary to handle the logarithmic behavior near the three-particle coalescence in a special way. The PS method has many virtues: no explicit assumptions need be made about the asymptotic behavior of the wavefunction near cusps or at large distances, the local energy is exactly equal to the calculated global energy at all collocation points, local errors go down everywhere with increasing resolution, the effective basis using Chebyshev polynomials is complete and simple, and the method is easily extensible to other bound states. This study serves as a proof-of-principle of the method for more general two- and possibly three-electron applications.Comment: 23 pages, 20 figures, 2 tables, Final refereed version - Some references added, some stylistic changes, added paragraph to matrix methods section, added last sentence to abstract

Observation of a plastic crystal in water-ammonia mixtures under high pressure and temperature

Solid mixtures of ammonia and water, the so-called ammonia hydrates, are thought to be major components of solar and extra-solar icy planets. We present here a thorough characterization of the recently reported high pressure (P)-temperature (T) phase VII of ammonia monohydrate (AMH) using Raman spectroscopy, X-ray diffraction, and quasi-elastic neutron scattering (QENS) experiments in the ranges 4-10 GPa, 450-600 K. Our results show that AMH-VII exhibits common structural features with the disordered ionico-molecular alloy (DIMA) phase, stable above 7.5 GPa at 300 K: both present a substitutional disorder of water and ammonia over the sites of a body-centered cubic lattice and are partially ionic. The two phases however markedly differ in their hydrogen dynamics, and QENS measurements show that AMH-VII is characterized by free molecular rotations around the lattice positions which are quenched in the DIMA phase. AMH-VII is thus a peculiar crystalline solid in that it combines three types of disorder: substitutional, compositional, and rotational

An echocardiographic-confirmed case of atrial myxoma causing cerebral embolic ischemic stroke: a case report

A myxoma is the most common primary tumor of the heart. It has been reported as the source of a cardiogenic embolism. Therefore, it is important for clinicians to detect the myxoma early via echocardiography to prevent complications, such as syncope, sudden death, and cerebral embolic ischemic stroke. This report presents the case of a 54-year-old female whose clinical manifestation of atrial myxoma was an ischemic stroke. Atrial myxoma was later confirmed as the cause of her symptoms via transesophageal echocardiography