240 research outputs found
A Nexafs Study of Nitric Oxide Layers Adsorbed from a nitrite Solution onto a Pt(111) Surface
NO molecules adsorbed on a Pt(111) surface from dipping in an acidic nitrite
solution are studied by near edge X-ray absorption fine structure spectroscopy
(NEXAFS), X-ray photoelectron spectroscopy (XPS), low energy electron
diffraction (LEED) and scanning tunnelling microscopy (STM) techniques. LEED
patterns and STM images show that no long range ordered structures are formed
after NO adsorption on a Pt(111) surface. Although the total NO coverage is
very low, spectroscopic features in N K-edge and O K-edge absorption spectra
have been singled out and related to the different species induced by this
preparation method. From these measurements it is concluded that the NO
molecule is adsorbed trough the N atom in an upright conformation. The maximum
saturation coverage is about 0.3 monolayers, and although nitric oxide is the
major component, nitrite and nitrogen species are slightly co-adsorbed on the
surface. The results obtained from this study are compared with those
previously reported in the literature for NO adsorbed on Pt(111) under UHV
conditions
The inhomogeneous mechanical behaviour of Ascending Thoracic Aortic Aneurism (ATAA)
Surgical management of ascending thoracic aortic aneurysms (aTAAs) relies on maximum diameter,
growth rate, and presence of connective tissue disorders. The surgical decision however is often
not considering that dissection and rupture do occur in patients who do not meet criteria for surgical
repair [1,2]. In this study the authors aim to investigate the mechanical properties of aTAAs to be
implemented in computational biomechanics models for a preclinical risk evaluation. Additionally,
in some recent studies, some data about the biomechanical properties of the aTAAs have been reported
[3], but without any relation to bicuspidal or tricuspidal aTAA. The aim of this study was to
investigate aTAA mechanical properties using a biaxial system to compare the circumferential and
axial stress-strain relations for bicuspidal and tricuspidal aTAAs
Free electron laser-driven ultrafast rearrangement of the electronic structure in Ti
High-energy density extreme ultraviolet radiation delivered by the FERMI seeded free-electron laser has been used to create an exotic nonequilibrium state of matter in a titanium sample characterized by a highly excited electron subsystem at temperatures in excess of 10 eV and a cold solid-density ion lattice. The obtained transient state has been investigated through ultrafast absorption spectroscopy across the Ti M2,3-edge revealing a drastic rearrangement of the sample electronic structure around the Fermi level occurring on a time scale of about 100 fs
Electronic structure of MAPbI3 and MAPbCl3: importance of band alignment
Since their first appearance, organic-inorganic perovskite absorbers have been capturing the attention of the scientific community. While high efficiency devices highlight the importance of band level alignment, very little is known on the origin of the strong n-doping character observed in the perovskite. Here, by means of a highly accurate photoemission study, we shed light on the energy alignment in perovskite-based devices. Our results suggest that the interaction with the substrate may be the driver for the observed doping in the perovskite samples
Fetal alcohol spectrum disorder and youth justice: a prevalence study among young people sentenced to detention in Western Australia
Objectives: To estimate the prevalence of fetal alcohol spectrum disorder (FASD) among young people in youth detention in Australia. Neurodevelopmental impairments due to FASD can predispose young people to engagement with the law. Canadian studies identified FASD in 11%–23% of young people in corrective services, but there are no data for Australia. Design: Multidisciplinary assessment of all young people aged 10–17 years 11 months and sentenced to detention in the only youth detention centre in Western Australia, from May 2015 to December 2016. FASD was diagnosed according to the Australian Guide to the Diagnosis of FASD. Participants: 99 young people completed a full assessment (88% of those consented; 60% of the 166 approached to participate); 93% were male and 74% were Aboriginal. Findings: 88 young people (89%) had at least one domain of severe neurodevelopmental impairment, and 36 were diagnosed with FASD, a prevalence of 36% (95% CI 27% to 46%). Conclusions: This study, in a representative sample of young people in detention in Western Australia, has documented a high prevalence of FASD and severe neurodevelopmental impairment, the majority of which had not been previously identified. These findings highlight the vulnerability of young people, particularly Aboriginal youth, within the justice system and their significant need for improved diagnosis to identify their strengths and difficulties, and to guide and improve their rehabilitation
Introduction of Zr in nanometric periodic Mg/Co multilayers
We study the introduction of a third material, namely Zr, within a nanometric
periodic Mg/Co structure designed to work as optical component in the extreme
UV (EUV) spectral range. Mg/Co, Mg/Zr/Co, Mg/Co/Zr and Mg/Zr/Co/Zr multilayers
are designed, then characterized in terms of structural quality and optical
performances through X-ray and EUV reflectometry measurements respectively. For
the Mg/Co/Zr structure, the reflectance value is equal to 50% at 25.1 nm and
45deg of grazing incidence and reaches 51.3% upon annealing at 200deg C.
Measured EUV reflectivity values of tri-layered systems are discussed in terms
of material order within a period and compared to the predictions of the
theoretical model of Larruquert. Possible applications are pointed out.Comment: 19 page
Medium-Term Complications Associated With Coronary Artery Aneurysms After Kawasaki Disease: A Study From the International Kawasaki Disease Registry.
Background Coronary artery aneurysms (CAAs) may occur after Kawasaki disease (KD) and lead to important morbidity and mortality. As CAA in patients with KD are rare and heterogeneous lesions, prognostication and risk stratification are difficult. We sought to derive the cumulative risk and associated factors for cardiovascular complications in patients with CAAs after KD. Methods and Results A 34-institution international registry of 1651 patients with KD who had CAAs (maximum CA
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