1,841 research outputs found
Characterization of Propagation Patterns with Omnipolar EGM in Epicardial Multi-Electrode Arrays
Omnipolar Electrogram (OP-EGM) is a recently proposed technique to characterize myocardial propagation in multi-electrode catheters regardless of the angle between propagation direction and catheter bipolar. This work aims to evaluate the accuracy of atrial propagation parameters obtained with OP-EGM in sinus rhythm (SR) and in different patterns of atrial fibrillation (AF).Real and simulated unipolar electrograms (u-EGMs) were used in this study. For both types of data, conduction velocity was obtained for each clique of 4 neighbour electrodes using OP-EGM. As a reference, conduction velocity was also computed from local activation times (LATs) using a linear propagation model.Analysis of simulated data showed that conduction velocity had good concordance with propagation patterns for both estimations, although the LAT-based errors were lower in most of the cases. When conduction velocity magnitude (CV) was 1 mm/ms, its estimation errors (expressed as mean ± std) calculated with OP-EGM and from LATs were 0.053 ± 0.005 mm/ms and 0.003 ±2.1 ×10-5 mm/ms, respectively, when focus was at 30 mm from the bottom of the tissue slice, while propagation direction angular errors were 6.64 ± 4.3°and 4.35 ± 2.8°. In real data, maps obtained with OP-EGM presented smoother and more coherent patterns than those based on LATs
Long-term survival and transmission of INI1-mutation via nonpenetrant males in a family with rhabdoid tumour predisposition syndrome
Rhabdoid tumour predisposition syndrome (RTPS) is a rare syndrome caused by inheritance of a mutated INI1 gene for which only two multigeneration families have been reported. To further characterise the genotype and phenotype of RTPS, we present a third family in which at least three cousins developed an atypical teratoid/rhabdoid tumour (AT/RT) at a young age. Two of these patients showed unusual long survival, and one of these developed an intracranial meningioma and a myoepithelioma of the lip in adulthood. Mutation analysis of INI1 revealed a germline G>A mutation in the donor splice site of exon 4 (c.500+1G>A) in the patients and in their unaffected fathers. This mutation prevents normal splicing and concomitantly generates a stop codon, resulting in nonsense-mediated mRNA decay. Biallelic inactivation of INI1 in the tumours, except for the meningioma, was confirmed by absence of nuclear INI1-protein staining. The myoepithelioma of one of the patients carried an identical somatic rearrangement in the NF2 gene as the AT/RT, indicating that both tumours originated from a common precursor cell. In conclusion, this study demonstrates for the first time transmission of a germline INI1-mutation in a RTPS family via nonpenetrant males, long-term survival of two members of this family with an AT/RT, and involvement of INI1 in the pathogenesis of myoepithelioma
Paleoceanography and ice sheet variability offshore Wilkes Land, Antarctica – Part 3: Insights from Oligocene–Miocene TEX86-based sea surface temperature reconstructions
The volume of the Antarctic continental ice
sheet(s) varied substantially during the Oligocene and
Miocene ( 34–5 Ma) from smaller to substantially larger
than today, both on million-year and on orbital timescales.
However, reproduction through physical modeling of a dynamic
response of the ice sheets to climate forcing remains
problematic, suggesting the existence of complex feedback
mechanisms between the cryosphere, ocean, and atmosphere
systems. There is therefore an urgent need to improve the
models for better predictions of these systems, including resulting
potential future sea level change. To assess the interactions
between the cryosphere, ocean, and atmosphere,
knowledge of ancient sea surface conditions close to the
Antarctic margin is essential. Here, we present a new TEX86-
based sea surface water paleotemperature record measured
on Oligocene sediments from Integrated Ocean Drilling
Program (IODP) Site U1356, offshore Wilkes Land, East
Antarctica. The new data are presented along with previously
published Miocene temperatures from the same site.
Together the data cover the interval between 34 and
11 Ma and encompasses two hiatuses. This record allows us
to accurately reconstruct the magnitude of sea surface temperature
(SST) variability and trends on both million-year
and glacial–interglacial timescales.Julian D. Hartman, Francesca Sangiorgi,
Henk Brinkhuis, and Peter K. Bijl acknowledge the NWO Netherlands
Polar Program project number 866.10.110. Stefan Schouten
was supported by the Netherlands Earth System Science Centre
(NESSC), funded by the Dutch Ministry of Education, Culture
and Science (OCW). Peter K. Bijl and Francien Peterse received
funding through NWO-ALW VENI grant nos. 863.13.002 and
863.13.016, respectively. Carlota Escutia and Ariadna Salabarnada
thank the Spanish Ministerio de EconimÃa y Competitividad for
grant CTM2014-60451-C2-1-P. We thank Alexander Ebbing
and Anja Bruls for GDGT sample preparation during their MSc
research. This research used samples from the Integrated Ocean
Drilling Program (IODP). IODP was sponsored by the US National
Science Foundation and participating countries under management
of Joined Oceanographic Institutions Inc
Line Defects in Molybdenum Disulfide Layers
Layered molecular materials and especially MoS2 are already accepted as
promising candidates for nanoelectronics. In contrast to the bulk material, the
observed electron mobility in single-layer MoS2 is unexpectedly low. Here we
reveal the occurrence of intrinsic defects in MoS2 layers, known as inversion
domains, where the layer changes its direction through a line defect. The line
defects are observed experimentally by atomic resolution TEM. The structures
were modeled and the stability and electronic properties of the defects were
calculated using quantum-mechanical calculations based on the
Density-Functional Tight-Binding method. The results of these calculations
indicate the occurrence of new states within the band gap of the semiconducting
MoS2. The most stable non-stoichiometric defect structures are observed
experimentally, one of which contains metallic Mo-Mo bonds and another one
bridging S atoms
- …