14,010 research outputs found
Minor salivary gland sialolithiasis: a clinical diagnostic challenge
Sialolithiasis is a non-neoplastic salivary gland disease that rarely affects the minor salivary glands. There are no guidelines in the literature which can suggest which is the best surgical approach to treat Minor Salivary Glands Sialolithiasis (MSGL). The present case was of a 48-year-old male patient complaining of painful swelling localized in the left back-commissural zone which was 0.5 mm in diameter, for which surgical enucleation approach was done and in that some small calcific masses ranging from 0.2 to 4 mm in diameter were found. They were surrounded by granulation tissue and associated with small pus oozing. Histopathological examination was carried out leading to a final diagnosis of MSGL
MeV Neutron Production from Thermal Neutron Capture in {6}^Li Simulated with Geant4
Various Li compounds are commonly used at neutron facilities as neutron
absorbers. These compounds provide one of the highest ratios of neutron
attenuation to -ray production. Unfortunately, the usage of these
compounds can also give rise to fast neutron emission with energies up to
almost 16 MeV. Historically, some details in this fast neutron production
mechanism can be absent from some modeling packages under some optimization
scenarios. In this work, we tested Geant4 to assess the performance of this
simulation toolkit for the fast neutron generation mechanism. We compare the
results of simulations performed with Geant4 to available measurements. The
outcome of our study shows that results of the Geant4 simulations are in good
agreement with the available measurements for Li fast neutron production,
and suitable for neutron instrument background evaluation at spallation neutron
sources.Comment: 6 pages, 3 figures, Proceeding of The Sixth European Conference on
Neutron Scattering, Zaragoza Spain, August 30 to September 4 201
In-Beam Background Suppression Shield
The long (3ms) proton pulse of the European Spallation Source (ESS) gives
rise to unique and potentially high backgrounds for the instrument suite. In
such a source an instrument capabilities will be limited by it's Signal to
Noise (S/N) ratio. The instruments with a direct view of the moderator, which
do not use a bender to help mitigate the fast neutron background, are the most
challenging. For these beam lines we propose the innovative shielding of
placing blocks of material directly into the guide system, which allow a
minimum attenuation of the cold and thermal fluxes relative to the background
suppression. This shielding configuration has been worked into a beam line
model using Geant4. We study particularly the advantages of single crystal
sapphire and silicon blocks .Comment: 12 pages, 8 figures, proceeding of NDS 2015, 4th International
Workshop on Neutron Delivery Systems, 28 -30 September 2015, ILL Grenoble,
Franc
The importance of the RET gene in thyroid cancer and therapeutic implications
Since the discovery of the RET receptor tyrosine kinase in 1985, alterations of this protein have been found in diverse thyroid cancer subtypes. RET gene rearrangements are observed in papillary thyroid carcinoma, which result in RET fusion products. By contrast, single amino acid substitutions and small insertions and/or deletions are typical of hereditary and sporadic medullary thyroid carcinoma. RET rearrangements and mutations of extracellular cysteines facilitate dimerization and kinase activation, whereas mutations in the RET kinase coding domain drive dimerization-independent kinase activation. Thus, RET kinase inhibition is an attractive therapeutic target in patients with RET alterations. This approach was initially achieved using multikinase inhibitors, which affect multiple deregulated pathways that include RET kinase. In clinical practice, use of multikinase inhibitors in patients with advanced thyroid cancer resulted in therapeutic efficacy, which was associated with frequent and sometimes severe adverse effects. However, remarkable progress has been achieved with the identification of novel potent and selective RET kinase inhibitors for the treatment of advanced thyroid cancer. Although expanded clinical validation in future trials is needed, the sustained antitumoural activity and the improved safety profile of these novel compounds is opening a new exciting era in precision oncology for RET-driven cancers
Consumer Attitudes and the Epidemiology of Inflation Expectations
This paper studies the formation of consumers’ infl‡ation expectations using micro-level data from the Michigan Survey. It shows that beyond the well-established socio-economic determinants of infl‡ation expectations like gender, income or education also other characteristics like the household’s fi…nancial situation and its purchasing attitudes matter. Respondents with current or expected …financial difficulties, with pessimistic attitudes about major purchases, or who expect income to go down in the future have considerably higher forecast errors, are further away from professional forecasts and have a stronger updward bias in their expectations than other households. However, their bias shrinks by more than the one of the average household in response to increasing media reporting about in‡flation
Adiabatic quantum dynamics of a random Ising chain across its quantum critical point
We present here our study of the adiabatic quantum dynamics of a random Ising
chain across its quantum critical point. The model investigated is an Ising
chain in a transverse field with disorder present both in the exchange coupling
and in the transverse field. The transverse field term is proportional to a
function which, as in the Kibble-Zurek mechanism, is linearly
reduced to zero in time with a rate , , starting
at from the quantum disordered phase () and ending
at in the classical ferromagnetic phase (). We first analyze
the distribution of the gaps -- occurring at the critical point --
which are relevant for breaking the adiabaticity of the dynamics. We then
present extensive numerical simulations for the residual energy
and density of defects at the end of the annealing, as a function of
the annealing inverse rate . %for different lenghts of the chain. Both
the average and are found to behave
logarithmically for large , but with different exponents, with , and
. We propose a mechanism for
-behavior of based on the Landau-Zener
tunneling theory and on a Fisher's type real-space renormalization group
analysis of the relevant gaps. The model proposed shows therefore a
paradigmatic example of how an adiabatic quantum computation can become very
slow when disorder is at play, even in absence of any source of frustration.Comment: 10 pages, 11 figures; v2: added references, published versio
A Data Fusion Technique to Detect Wireless Network Virtual Jamming Attacks
The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Wireless communications are potentially exposed to jamming due to the openness of the medium and, in particular, to virtual jamming, which allows more energy-efficient attacks. In this paper we tackle the problem of virtual jamming attacks on IEEE 802.11 networks and present a data fusion solution for the detection of a type of virtual jamming attack (namely, NAV attacks), based on the real-time monitoring of a set of metrics. The detection performance is evaluated in a number of real scenarios
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