190 research outputs found
X-ray scattering study of GaN nanowires grown on Ti/AlO by molecular beam epitaxy
GaN nanowires (NWs) grown by molecular beam epitaxy on Ti films sputtered on
AlO are studied by X-ray diffraction (XRD) and grazing incidence
small-angle X-ray scattering (GISAXS). XRD, performed both in symmetric Bragg
reflection and at grazing incidence, reveals Ti, TiO, TiAl, and
TiON crystallites with in-plane and out-of-plane lattice parameters
intermediate between those of AlO and GaN. These topotaxial
crystallites in Ti film, formed due to interfacial reactions and N exposure,
possess fairly little misorientation with respect to AlO. As a
result, GaN NWs grow on the top TiN layer possessing a high degree of epitaxial
orientation with respect to the substrate. The measured GISAXS intensity
distributions are modeled by the Monte Carlo method taking into account the
orientational distributions of NWs, a variety of their cross-sectional shapes
and sizes, and roughness of their side facets. The cross-sectional size
distributions of the NWs and the relative fractions of and
side facets are determined
Direct image to subtype prediction for brain tumors using deep learning
BACKGROUND: Deep Learning (DL) can predict molecular alterations of solid tumors directly from routine histopathology slides. Since the 2021 update of the World Health Organization (WHO) diagnostic criteria, the classification of brain tumors integrates both histopathological and molecular information. We hypothesize that DL can predict molecular alterations as well as WHO subtyping of brain tumors from hematoxylin and eosin-stained histopathology slides. METHODS: We used weakly supervised DL and applied it to three large cohorts of brain tumor samples, comprising N = 2845 patients. RESULTS: We found that the key molecular alterations for subtyping, IDH and ATRX, as well as 1p19q codeletion, were predictable from histology with an area under the receiver operating characteristic curve (AUROC) of 0.95, 0.90, and 0.80 in the training cohort, respectively. These findings were upheld in external validation cohorts with AUROCs of 0.90, 0.79, and 0.87 for prediction of IDH, ATRX, and 1p19q codeletion, respectively. CONCLUSIONS: In the future, such DL-based implementations could ease diagnostic workflows, particularly for situations in which advanced molecular testing is not readily available
Backward bending structure of Phillips Curve in Japan, France, Turkey and the U.S.A.
This work aims to analyse the cointegration and the causality
relationship between inflation and unemployment by using nonlinear
A.R.D.L. and two popular nonlinear causality tests for the period from
1960 to 2016 in Japan, Turkey, the U.S.A. and from 1970 to 2016 in
France. This study complements the previous empirical papers.
However, it differs from the existing literature with simultaneous
use of nonlinear A.R.D.L. and causality methods. Nonlinear A.R.D.L.
determined that there is a long run relationship between inflation
and unemployment; between economic growth and unemployment
for Japan, France, the U.S.A. and Turkey
Multicentre evaluation of the Naída Ci Q70 sound processor: Feedback from cochlear implant users and professionals
The aim of this survey was to gather data from both implant recipients and professionals on the ease of use of the Naída CI Q70 (Naída CI) sound processor from Advanced Bionics and on the usefulness of the new functions and features available. A secondary objective was to investigate fitting practices with the new processor. A comprehensive user satisfaction survey was conducted in a total of 186 subjects from 24 centres. In parallel, 23 professional questionnaires were collected from 11 centres. Overall, there was high satisfaction with the Naída CI processor from adults, children, experienced and new CI users as well as from professionals. The Naída CI processor was shown as being easy to use by all ages of recipients and by professionals. The majority of experienced CI users rated the Naída CI processor as being similar or better than their previous processor in all areas surveyed. The Naída CI was recommended by the professionals for fitting in all populations. Features like UltraZoom, ZoomControl and DuoPhone would not be fitted to very young children in contrast to adults. Positive ratings were obtained for ease of use, comfort and usefulness of the new functions and features of the Naída CI sound processor. Seventy-seven percent of the experienced CI users rated the new processor as being better than their previous sound processor from a general point of view. The survey also showed that fitting practices were influenced by the age of the user
Toxoplasma DJ-1 Regulates Organelle Secretion by a Direct Interaction with Calcium-Dependent Protein Kinase 1
Human DJ-1 is a highly conserved and yet functionally enigmatic protein associated with a heritable form of Parkinson’s disease. It has been suggested to be a redox-dependent regulatory scaffold, binding to proteins to modulate their function. Here we present the X-ray crystal structure of the Toxoplasma orthologue Toxoplasma gondii DJ-1 (TgDJ-1) at 2.1-Å resolution and show that it directly associates with calcium-dependent protein kinase 1 (CDPK1). The TgDJ-1 structure identifies an orthologously conserved arginine dyad that acts as a phospho-gatekeeper motif to control complex formation. We determined that the binding of TgDJ-1 to CDPK1 is sensitive to oxidation and calcium, and that this interaction potentiates CDPK1 kinase activity. Finally, we show that genetic deletion of TgDJ-1 results in upregulation of CDPK1 expression and that disruption of the CDPK1/TgDJ-1 complex in vivo prevents normal exocytosis of parasite virulence-associated organelles called micronemes. Overall, our data suggest that TgDJ-1 functions as a noncanonical kinase-regulatory scaffold that integrates multiple intracellular signals to tune microneme exocytosis in T. gondii. IMPORTANCE Apicomplexan parasites such as Toxoplasma and Plasmodium are obligate intracellular parasites that require the protective environment of a host cell in order to replicate and survive within a host organism. These parasites secrete effector proteins from specialized apical organelles to select and invade a chosen host cell. The secretion of these organelles is a tightly regulated process coordinated by endogenous small molecules and calcium-dependent protein kinases. We previously identified the Toxoplasma orthologue of the highly conserved protein DJ-1 as a regulator of microneme secretion, but the molecular basis for this was not known. We have now identified the molecular mechanism for how TgDJ-1 regulates microneme secretion. TgDJ-1 interacts with the kinase responsible for the secretion of these organelles (calcium-dependent kinase 1) and synergizes with calcium to potentiate kinase activity. This interaction is direct, phosphodependent, and necessary for the normal secretion of these important organelles
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