Self-assembly of iron nanoclusters on the Fe3O4(111) superstructured surface

We report on the self-organized growth of a regular array of Fe nanoclusters on a nanopatterned magnetite surface. Under oxidizing preparation conditions the (111) surface of magnetite exhibits a regular superstructure with three-fold symmetry and a 42 A periodicity. This superstructure represents an oxygen terminated (111) surface, which is reconstructed to form a periodically strained surface. This strain patterned surface has been used as a template for the growth of an ultrathin metal film. A Fe film of 0.5 A thickness was deposited on the substrate at room temperature. Fe nanoclusters are formed on top of the surface superstructure creating a regular array with the period of the superstructure. We also demonstrate that at least the initial stage of Fe growth occurs in two-dimensional mode. In the areas of the surface where the strain pattern is not formed, random nucleation of Fe was observed.Comment: 6 pages, 3 figure

Atomically Resolved Spin-Dependent Tunnelling on the Oxygen-Terminated Fe3O4 (111)

We employ spin-polarized (SP) STM to study the spin-dependent tunneling between a magnetite (111) sample and an antiferromagnetic tip through a vacuum barrier at room temperature. Atomic scale STM images show significant magnetic contrast corresponding to variations in the local surface states induced by oxygen vacancies. The estimated variations in tunneling magnetoresistance (TMR) of 250% suggest that the spin-transport properties are significantly altered locally by the presence of surface defects.Comment: 10 pages, 4 figure

Advancing the science of cancer cost measurement: challenges and opportunities

Cancer accounts for a major proportion of national health expenditures, which are expected to increase in the future. This paper aims to identify major challenges with estimating cancer related costs, and discuss international comparisons, and recommendations for future research. Methods. It starts from the experience of an international workshop aimed at comparing cancer burden evaluation methods, improving results comparability, discussing strengths and criticisms of different approaches. Results. Three methodological themes necessary to inform the analysis are identified and discussed: data availability; costs definition; epidemiological measures. Conclusions. Cost evaluation is applied to cancer control interventions and is relevant for public health planners. Despite their complexity, international comparisons are fundamental to improve, generalize and extend cost evaluation to different contexts

Investigating the high energy QCD approaches for prompt photon production at the LHC

We investigate the rapidity and transverse momentum distributions of the prompt photon production at the CERN LHC energies considering the current perturbative QCD approaches for this scattering process. Namely, we compare the predictions from the usual NLO pQCD calculations to the the color dipole formalism, using distinct dipole cross sections. Special attention is paid to parton saturation models at high energies, which are expected to be important at the forward rapidities in pp collisions at the LHC.Comment: Contribution to the proceedings of the 3rd International Conference on Hard and Electro-Magnetic Probes of High-Energy Nuclear Collisions (Hard Probes 2008), 8-14 June 2008, Illa da Toxa (Galicia-Spain). Talk presented by M.V.T. Machad

Trichobezoars in children: therapeutic complications

Trichobezoars are concretions formed by the accumulation of hair or fibers in the gastrointestinal tract, usually associated with underlying psychiatric disorders in females between 13 and 20 years old. Endoscopy, the gold standard for diagnosis, brings some additional advantages: sample taking, size reducing and, rarely, mass removal. This study shows that endoscopy can cause severe complications resulting in a surgical emergency

Oxide nanotemplates for self-assembling "solid" building blocks

It is widely accepted that self-assembling building blocks is one of the promising ways for engineering new materials. Recent years reveal substantial progress in fabricating colloidal particles, polymer blocks and supramolecular aggregates of organic molecules. Despite of substantial progress in molecular self-assembly there is still a lack of simple blocks made of "solid matter" (e.g. metals, oxides etc.) with well-defined crystal structure and spatial order. Here we demonstrate that ordered arrays of metal nanoclusters can be fabricated by self-assembly on a wide range of oxide templates. These nano-templates are produced either by depositing an alien oxide film or by oxidizing a metal/metal oxide substrate.Comment: 11 pages, 2 figures added DFT calculations and Fig.

Suicide and suicides attempts in Italian prison epidemiological findings from the “Triveneto” area, 2010-2016

The aim of this observational study was to assess rates of suicide and suicide attempts, in relation to gender, age, place of birth and security levels, in north-eastern Italian prisons during 2010-2016, and investigate associations with prison overcrowding, offence type and prior self-harm and suicide attempts. The study was based on individual data on suicides and suicide attempts from 16 prisons, with an average yearly number of 3,900 inmates during the study period, for all prisons combined. Descriptive and binomial regression analyses were performed. Rates of suicide and suicide attempts in Triveneto prisons were 1and 15 per 1,000 inmates, respectively. More than 90% of suicides and suicide attempters were men aged between 21 and 49 years old, and most had committed violent offences. Only half the prisoners who died by suicide and 30% of those who made a suicide attempt in custody were Italians. ‘Cooperative witnesses’ had the highest mean suicide attempt rate (30/1,000 inmates). Fourteen per cent of suicides and 19% of attempters had a prior history of suicide attempts and self-injury. In binomial regression analyses, predictors of suicidal behaviour were being a male inmate in standard security conditions, with a mean age of 30 years. The study highlighted that there is a need for suicide prevention policies in Triveneto; these should take into account predictors of suicidal behaviours and individual characteristics of suicidal inmates. More research is warranted in order to both evaluate the effectiveness of prevention plans and better assess risk of suicide in specific groups, such as cooperative witnesses