A cotunneling mechanism for all-electrical Electron Spin Resonance of single adsorbed atoms

The recent development of all-electrical electron spin resonance (ESR) in a scanning tunneling microscope (STM) setup has opened the door to vast applications. Despite the fast growing number of experimental works on STM-ESR, the fundamental principles remains unclear. By using a cotunneling picture, we show that the spin resonance signal can be explained as a time-dependent variation of the tunnel barrier induced by the alternating electric driving field. We demonstrate how this variation translates into the resonant frequency response of the direct current. Our cotunneling theory explains the main experimental findings. Namely, the linear dependence of the Rabi flop rate with the alternating bias amplitude, the absence of resonant response for spin-unpolarized currents, and the weak dependence on the actual atomic species.Comment: 11 pages, 3 figure

Dimensional deformation of sine-Gordon breathers into oscillons

Oscillons are localized field configurations oscillating in time with lifetimes orders of magnitude longer than their oscillation period. In this paper, we simulate non-travelling oscillons produced by deforming the breather solutions of the sine-Gordon model. Such a deformation treats the dimensionality of the model as a real parameter to produce spherically symmetric oscillons. After considering the post-transient oscillation frequency as a control parameter, we probe the initial parameter space to show how the availability of oscillons depends on the number of spatial dimensions. For small dimensional deformations, our findings are consistent with the lack of a minimal amplitude bound to form oscillons. In $D\gtrsim 2$ spatial dimensions, we observe solutions undergoing intermittent phases of contraction and expansion in their cores. Knowing that stable and unstable configurations can be mapped to disjoint regions of the breather parameter space, we find that amplitude modulated solutions are located in the middle of both stability regimes. This displays the dynamics of critical behavior for solutions around the stability limit.Comment: 18+7 pages, 20 figures. Minor typos fixed. Comments are welcom

Magnetic study on biodistribution and biodegradation of oral magnetic nanostructures in the rat gastrointestinal tract

We have undertaken a magnetic study on the oral biodistribution and biodegradation of nude maghemite nanoparticles of 10 nm average size (MNP) and probiotic bacteria, Lactobacillus fermentum, containing thousands of these same nanoparticles (MNP-bacteria). Using AC magnetic susceptibility measurements of the stomach, small intestine, cecum and large intestine obtained after rat sacrifice, and iron content determination by ICP-OES, we have monitored the biodistribution and biodegradation of the maghemite nanoparticles along the gastrointestinal tract, after oral administration of both MNP and MNP-bacteria. The results revealed that the amount of magnetic nanoparticles accumulated in intestines is sensibly higher when MNP-bacteria were administered, in comparison with MNP. This confirms our initial hypothesis that the use of probiotic bacteria is a suitable strategy to assist the magnetic nanoparticles to overcome the stomach medium, and to achieve their accumulation in intestines. This finding opens doors to different applications. Since iron absorption in humans takes place precisely in the intestines, the use of MNP-bacteria as an iron supplement is a definite possibility. We have actually illustrated how the administration of MNP-bacteria to iron-deficient rats corrects the iron levels after two weeks of treatment

Stereoscopic three-dimensional visualization applied to multimodal brain images: Clinical applications and a functional connectivity atlas

Effective visualization is central to the exploration and comprehension of brain imaging data. While MRI data are acquired in three-dimensional space, the methods for visualizing such data have rarely taken advantage of three-dimensional stereoscopic technologies. We present here results of stereoscopic visualization of clinical data, as well as an atlas of whole-brain functional connectivity. In comparison with traditional 3D rendering techniques, we demonstrate the utility of stereoscopic visualizations to provide an intuitive description of the exact location and the relative sizes of various brain landmarks, structures and lesions. In the case of resting state fMRI, stereoscopic 3D visualization facilitated comprehension of the anatomical position of complex large-scale functional connectivity patterns. Overall, stereoscopic visualization improves the intuitive visual comprehension of image contents, and brings increased dimensionality to visualization of traditional MRI data, as well as patterns of functional connectivity

Parameterized optimized effective potential for atoms

The optimized effective potential equations for atoms have been solved by parameterizing the potential. The expansion is tailored to fulfill the known asymptotic behavior of the effective potential at both short and long distances. Both single configuration and multi configuration trial wave functions are implemented. Applications to several atomic systems are presented improving previous works. The results here obtained are very close to those calculated in either the Hartree-Fock and the multi configurational Hartree-Fock framework.Comment: 8 pages, 3 figure

Eficacia y seguridad del adhesivo tisular Tisuacryl en el cierre de la piel de la episiotomía

Se realizó un ensayo clínico fase III, en el Hospital Docente Materno Infantil 10 de Octubre, de Ciudad de La Habana, Cuba, entre julio de 1999 y marzo del 2000, con el objetivo de evaluar la eficacia y seguridad del adhesivo tisular Tisuacryl en el cierre de la piel de la episiotomía. Cada grupo constó de 300 pacientes, de acuerdo a los criterios de inclusión establecidos para el ensayo. En el grupo estudio se presentaron menos molestias en la episiorrafia (95.6 %) que en el grupo control (56.3 %) a los 30 minutos post parto, así como al tercer día posterior al nacimiento (97.6 % vs. 61.3 %). Al séptimo día, los resultados en el afrontamiento, estética y molestias en la herida fueron significativamente mejores con el adhesivo tisular evaluado. Los riesgos relativos de resultados adversos al séptimo día posterior al parto fueron 3.2 veces mayores en relación con afrontamiento y 2.9 veces con la estética no satisfactorias cuando se utilizó catgut cromado al comparar con el Tisuacryl. Para las molestias en la episiorrafia, el riesgo relativo se elevó a 24.2, todos con diferencias estadísticas significativas. Se concluye que el uso del adhesivo tisular Tisuacryl para el cierre de la piel en la episiotomía tiene menor probabilidad de afrontamiento y estética de la herida no satisfactoria y de menor sensación dolorosa en la herida quirúrgica que el catgut cromado.Peer Reviewe

On some results of Cufaro Petroni about Student t-processes

This paper deals with Student t-processes as studied in (Cufaro Petroni N 2007 J. Phys. A, Math. Theor. 40(10), 2227-2250). We prove and extend some conjectures expressed by Cufaro Petroni about the asymptotical behavior of a Student t-process and the expansion of its density. First, the explicit asymptotic behavior of any real positive convolution power of a Student t-density with any real positive degrees of freedom is given in the multivariate case; then the integer convolution power of a Student t-distribution with odd degrees of freedom is shown to be a convex combination of Student t-densities with odd degrees of freedom. At last, we show that this result does not extend to the case of non-integer convolution powers.Comment: 11 page

Towards an alignment of national research programmes and funding for CST technologies in Europe

ABSTRACT: One of the STAGE-STE project work packages aims to develop relations with public bodies relevant to Concentrating Solar Thermal (CST) research, such as national research funding agencies, ministries and other leading decision making bodies, in order to foster coordination and alignment of research programmes and funding at European level. Working groups have been created in eight European countries and concept notes were prepared regarding each group’s position on national CST research and funding programmes and its possible alignment at European scale. General trends and main conclusions drawn from the concept notes are presented, aiming to provide clues and common themes to the development of aligned CST research and funding programmes. Although the National Working Groups present different approaches there are coincident points, thus a common Research and Technological Development agenda for CST can be achieved at European scale. The alignment of CST research funding represents an harder task and will demand the improvement of available funding schemes or the development of a new one. However, there is some convergence regarding the general characteristics of the scheme and the kind of projects to be funded.info:eu-repo/semantics/publishedVersio