Cross sections of proton-induced reactions on 152Gd, 155Gd and 159Tb with emphasis on the production of selected Tb radionuclides

Cross sections are presented for various Dy, Tb and Gd radionuclides produced in the proton bombardment of 159Tb as well as for the reactions 152Gd(p,4n)149Tb and 155Gd(p,4n)152Tb up to 66 MeV. The experimental excitation functions are compared with theoretical predictions by means of the geometrydependent hybrid (GDH) model as implemented in the code ALICE/ASH, as well as with values from the TENDL-2012 library and previous literature experimental data, where available. Physical yields have been derived for the production of some of the medically important radioterbiums, namely 149Tb (radionuclide therapy), 152Tb (PET) and 155Tb (SPECT). The indirect production of high-purity 155Tb via the decay of its precursor 155Dy is reported. The possibility of a large-scale production facility based on a commercial 70 MeV cyclotron is also discussed

Unusual hyperfine interaction of Dirac electrons and NMR spectroscopy in graphene

Theory of nuclear magnetic resonance (NMR) in graphene is presented. The canonical form of the electron-nucleus hyperfine interaction is strongly modified by the linear electronic dispersion. The NMR shift and spin-lattice relaxation time are calculated as function of temperature, chemical potential, and magnetic field and three distinct regimes are identified: Fermi-, Dirac-gas, and extreme quantum limit behaviors. A critical spectrometer assessment shows that NMR is within reach for fully 13C enriched graphene of reasonable size.Comment: 5 pages, 3 figure

Finite-size scaling of pseudo-critical point distributions in the random transverse-field Ising chain

We study the distribution of finite size pseudo-critical points in a one-dimensional random quantum magnet with a quantum phase transition described by an infinite randomness fixed point. Pseudo-critical points are defined in three different ways: the position of the maximum of the average entanglement entropy, the scaling behavior of the surface magnetization, and the energy of a soft mode. All three lead to a log-normal distribution of the pseudo-critical transverse fields, where the width scales as $L^{-1/\nu}$ with $\nu=2$ and the shift of the average value scales as $L^{-1/\nu_{typ}}$ with $\nu_{typ}=1$, which we related to the scaling of average and typical quantities in the critical region.Comment: 4 pages, 2 figure

Anomalous diffusion in disordered multi-channel systems

We study diffusion of a particle in a system composed of K parallel channels, where the transition rates within the channels are quenched random variables whereas the inter-channel transition rate v is homogeneous. A variant of the strong disorder renormalization group method and Monte Carlo simulations are used. Generally, we observe anomalous diffusion, where the average distance travelled by the particle, []_{av}, has a power-law time-dependence []_{av} ~ t^{\mu_K(v)}, with a diffusion exponent 0 \le \mu_K(v) \le 1. In the presence of left-right symmetry of the distribution of random rates, the recurrent point of the multi-channel system is independent of K, and the diffusion exponent is found to increase with K and decrease with v. In the absence of this symmetry, the recurrent point may be shifted with K and the current can be reversed by varying the lane change rate v.Comment: 16 pages, 7 figure

Stress model for the wrinkling of ion-implanted layers

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Strong Griffiths singularities in random systems and their relation to extreme value statistics

We consider interacting many particle systems with quenched disorder having strong Griffiths singularities, which are characterized by the dynamical exponent, z, such as random quantum systems and exclusion processes. In several d=1 and d=2 dimensional problems we have calculated the inverse time-scales, t^{-1}, in finite samples of linear size, L, either exactly or numerically. In all cases, having a discrete symmetry, the distribution function, P(t^{-1},L), is found to depend on the variable, u=t^{-1}L^{z/d}, and to be universal given by the limit distribution of extremes of independent and identically distributed random numbers. This finding is explained in the framework of a strong disorder renormalization group approach when, after fast degrees of freedom are decimated out the system is transformed into a set of non-interacting localized excitations. The Frechet distribution of P(t^{-1},L) is expected to hold for all random systems having a strong disorder fixed point, in which the Griffiths singularities are dominated by disorder fluctuations.Comment: 11 pages, 11 figure

Role of oxygen vacancy defect states in the n-type conduction of β-Ga[sub 2]O[sub 3]

Based on semiempirical quantum-chemical calculations, the electronic band structure of β-Ga2O3 is presented and the formation and properties of oxygen vacancies are analyzed. The equilibrium geometries and formation energies of neutral and doubly ionized vacancies were calculated. Using the calculated donor level positions of the vacancies, the high temperature n-type conduction is explained. The vacancy concentration is obtained by fitting to the experimental resistivity and electron mobility

Impact of diabetes mellitus on long-term outcome after unstable angina and non-ST-segment elevation myocardial infarction treated with a very early invasive strategy

Aims/hypothesis: We sought to evaluate the impact of diabetes mellitus on long-term outcome in patients with unstable angina and non-ST-segment elevation myocardial infarction treated with a very early invasive strategy. Methods: We carried out a prospective cohort study in 270 diabetic and 1163 non-diabetic patients with unstable angina and non-ST-segment elevation myocardial infarction. All patients underwent coronary angiography and, if appropriate, subsequent revascularisation within 24 hours of admission. The primary endpoint was all-cause mortality during follow-up for up to 60 months. Results: Diabetic patients had less favourable baseline characteristics including more advanced coronary artery disease and more severe unstable angina and non-ST-segment elevation myocardial infarction. Percutaneous coronary intervention was performed in 53% of diabetic patients and 56% of non-diabetic patients. Coronary artery bypass grafting was done in 21% of diabetic patients and 12% of non-diabetic patients. In-hospital mortality (4.1% vs 1.3%; hazard ratio 3.47; 95% CI: 1.57 to 7.64; p=0.002) and long-term mortality (9.7% vs 4.9%; hazard ratio 2.11; 95% CI: 1.33 to 3.36; p=0.002) were significantly higher in diabetic patients. After adjustment for differences in baseline characteristics, diabetes mellitus was no longer an independent predictor of long-term mortality (hazard ratio 1.43; 95% CI: 0.74 to 2.78; p=0.292). Conclusions/interpretation: Diabetic patients treated with a very early invasive strategy for unstable angina and non-ST-segment elevation myocardial infarction have a higher in-hospital and long-term mortality that is largely explained by their less favourable baseline characteristics including more advanced coronary artery disease and more severe unstable angina and non-ST-segment elevation myocardial infarctio