Acute hepatitis caused by minocycline.

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Colonoscopic findings in coeliac disease on a gluten-free diet

Background: to date, there are few data on colonoscopic findings in patients with celiac disease, and most of these obtained in patients with iron deficiency anaemia. Aims: we assessed colonoscopic findings in unselected pa tients with coeliac disease, since there are no studies available also considering morphological aspects, and there is literature sugges tion of increased prevalence of colorectal tumours. Material and methods: colonoscopies with multiple biopsies were retrospectively analyzed in 42 coeliac disease patients on gluten-free diet above age 40; 16 had clinical or laboratory fea tures of iron deficiency anaemia. Mucosal biopsies were evaluated for the presence of intraepithelial lymphocytes and of mucosal eosinophils, in addition to conventional histologic assessment, and compared with those obtained in 15 controls. Results: macroscopic abnormalities (polyps, diverticula, in flammatory changes) were found in 26% of patients. Microscopic abnormalities (lymphocytic colitis, melanosis coli, rectal histiocyto sis) were found in 36% of patients. None of these findings was found in controls. Coeliac disease patients had significantly higher eosinophil score than controls in the right colon, whereas this was not significantly different between groups in the left colon. Conclusions: colonoscopic findings in coeliac disease on gluten-free diet may reveal significant findings, even in patients without iron deficiency anaemia. There is the need of further stud ies in larger cohorts of patients to establish whether colonoscopy in these patients may be clinically useful

Surface states characterization in the strongly interacting graphene/Ni(111) system

By combining nonlinear photoemission experiments and density functional theory calculations, we study the modification of Ni(111) surface states induced by the presence of graphene. The main result is that graphene is able to displace the Ni(111) surface states from the valence band close to the Fermi level uncovering the d-band of Ni. The shift of the surface states away from the Fermi level modifies their k-dispersion and the effective mass. The unoccupied image state of graphene/Ni(111) has been also characterized. The ab initio calculations give a theoretical insight into the electronic properties of graphene/Ni(111) in the two stable top-fcc and top-bridge phases showing that the interface properties are poorly dependent on the stacking. The screening properties to an externally applied electric field are also discussed

Spectroscopic evidence of in-gap states at the SrTiO3/LaAlO3 ultrathin interfaces

Experimental evidence of differences in the electronic properties of an insulating and a conducting SrTiO3/LaAlO3 interface is provided by soft x-ray spectroscopies. While core level photoemission measurements show that only at the conducting interface Ti ions with 3+ ionization state are present, by using resonant photoemission and x-ray absorption spectroscopies, it is shown that in both samples in-gap states with a Ti 3d character are present, but their density is higher at the conducting interface

Tracking the amorphous to epitaxial transition in RF-sputtered cubic BFO-STO heterojunctions by means of X-ray photoelectron diffraction

The epitaxial growth of cubic BiFeO3 ultrathin films on SrTiO3 (001) substrates by off-axis RF sputtering is demonstrated, suitable to X-ray spectroscopies interface investigation. X-ray photoelectron diffraction is used as a tool to probe the long-range crystal order and to track the transition from amorphous to epitaxial growth as a function of deposition parameters. Further spectroscopic measurements, in particular, X-ray linear dichroism on the Fe L 3, 2 edge, confirm the heteroepitaxial growth of BiFeO3 and clearly indicate a 3+ valence state for the iron cation. Finally, XPS is used to reconstruct the band alignment diagram, which results in a staggered configuration with a remarkable energy shift of the SrTiO3 band edges which can ultimately favor the n-type doping of SrTiO3

Grain size and stoichiometry control over RF-sputtered multiferroic BiFeO3 thin films on silicon substrates

This work reports the morphological and chemical characterization of multiferroic BiFeO3 polycrystalline thin films grown on Si(111) by RF-sputtering. Results are shown for a large set of samples and a wide array of experimental techniques, including imaging (atomic/piezoresponse force microscopy) and spectroscopic (μ-Raman, X-ray photoemission, X-ray diffraction) probes. Through growth and post-growth annealing treatment, a fine control over stoichiometry, grain size, grain orientation, crystal order and surface roughness is achieved. In particular, the grain size can be tailored from nanocrystals to large micrometric plates as a function of the annealing temperature. For the optimal stoichiometric sample, an additional X-ray absorption and magnetic circular dichroism analysis has been carried out, which provides high quality spectra comparable with epitaxial films and further proves the expected strong local antiferromagnetic order

SAM Functionalized ZnO Nanowires for Selective Acetone Detection: Optimized Surface Specific Interaction Using APTMS and GLYMO Monolayers

In modern days, self-assembled monolayer (SAM) functionalized surfaces represent an interesting tool for the development of ultrasensitive and selective sensing platforms for the detection of chemical substances such as biomolecules and gases. The ability of SAM to generate different functional groups on a single surface such as zinc oxide (ZnO) can be used to immobilize biomolecules and detect different analytes such as gases, proteins, etc. Herein, SAM functionalized ZnO NW-based sensors are developed for acetone exhaled breath analysis. ZnO NWs are synthesized using a vapor–liquid–solid mechanism and their functionalization is done with two different SAMs, i.e., (3-aminopropyl)trimethoxysilane (APTMS) and 3-glycidoxypropyltrimethoxysilane (GLYMO). The enhancement in the electron depletion layer resistance (and also width) due to the capturing of electrons from the ZnO NWs surface by APTMS and GLYMO molecules is found to be the major reason in their superior sensing performances. The amine (–NH2) groups of APTMS monolayer enhance the sensors selectivity toward acetone due to their reactions with acetone molecules, which produce imine in addition to water molecules. Moreover, after the functionalization with APTMS SAMs, the detection limits of the sensors are improved from 6 to 0.5 ppm, which makes these devices potential candidates for acetone exhaled breath analysis

Intrinsic origin of interface states and band offset profiling of nanostructured LaAlO3/SrTiO3 heterojunctions probed by element-specific resonant spectroscopies

The origin of electronic states at the basis of the 2DEG found in conducting LaAlO 3 /SrTiO 3 interfaces (5 u.c. LaAlO 3 ) is investigated by resonant photoemission experiments at the Ti L 2,3 and La M 4,5 edges. As shown by the resonant enhancement at the Ti L 2,3 edge, electronic states at E F receive a dominant contribution from Ti 3d states. Both Ti and La resonance effects in the valence-band region are used to estimate the valence-band maxima at the two sides of the junction. Through a comparison with the valence-band states of the LaAlO 3 and SrTiO 3 parent compounds, we reconstruct the band diagram of the heterojunction, which is revealed to be type I (straddling gap), with a large notch of the band profile at the interface as compared with the reference insulating (3 u.c. LaAlO 3 ) interface