1,675 research outputs found
AA-stacked bilayer square ice between graphene layers?
Water confined between two layers with separation of a few Angstrom forms
layered two- dimensional ice structure. Using large scale molecular dynamics
simulations with the adoptable ReaxFF interatomic potential we found that flat
monolayer ice with a rhombic-square structure nucleates between graphene layers
which is non-polar and non-ferroelectric. Two layers of water are found to
crystallize into a square lattice close to the experimental found AA-stacking
[G. Algara- Siller et al. Nature 519, 443445 (2015)]. Each layer has a net
dipole moment which are in opposite direction. Bilayer ice is also non-polar
and non-ferroelectric. For three layer ice we found that each layer has a
crystal structure similar to monolayer ice
Experiencia clÃnica del tratamiento con onabotulinumtoxin A en pacientes con migraña refractaria
To analyse our experience in the treatment of refractory chronic migraine,
episodic frequent refractory migraine (>= 10 days/month), with onabotulinumtoxin
A (OnabotA). PATIENTS AND METHODS. Retrospective analysis of patients with
refractory migraine who underwent, at least two sessions of OnabotA pericranial
injections following the PREEMPT protocol between 2008 and 2012. The efficacy of
OnabotA was evaluated comparing the basal situation with 12-16 weeks after the
second session. We analysed the subjective improvement of the patients, number of
days with headache, preventive and abortive drugs consumption, and adverse
effects. RESULTS. Forty-one patients (37 women, 4 male) were identified. 65.8%
patients experienced subjective improvement after OnabotA treatment. 36.58%
responded (reduction of > 50% in headache days). Differences between days with
headache before the first session (24.5 +/- 7.3), and 12-16 weeks after the
second session (17.4 +/- 11.6), as well as the differences between the number of
abortive drugs taken before the first session (26.8 +/- 23.1) and 12-16 weeks
after the second session (16.7 +/- 19.3), were statistically significant (p <
0.001). Subgroups analysis showed that all differences were significant, except
for the reduction of the number of days with headache in patients with episodic
frequent refractory migraine. CONCLUSION. Our work shows that treatment with
OnabotA is safe and useful in patients with episodic and chronic refractory
migraine, including those patients with medication overuse headache
Fermented Goat’s Milk Consumption Improves Duodenal Expression of Iron Homeostasis Genes during Anemia Recovery
Despite the crucial roles of duodenal cytochrome b (Dcytb), divalent metal transporter 1 (DMT1), ferritin light chain (Ftl1), ferroportin 1 (FPN1), transferrin receptor 1 (TfR1), and hepcidin antimicrobial peptide (Hamp) in Fe metabolism, no studies have investigated the modulations of these genes during Fe repletion with fermented milks. Analysis included Fe status markers and gene and protein expression in enterocytes of control and anemic animals fed fermented milks. Fermented goat’s milk up-regulated enterocyte Dcytb, DMT1, FPN1, and Ftl1 and down-regulated TfR1 and Hamp gene expression in control and anemic animals. Anemia decreased Dcytb, DMT1, and Ftl1 in animals fed fermented cow’s milk and up-regulated TfR1 and Hamp expression. Fe overload down-regulated Dcytb and TfR1 in animals fed fermented cow’s milk and up-regulated DMT1 and FPN1 gene expression. Fermented goat’s milk increased expression of duodenal Dcytb, DMT1, and FPN1 and decreased Hamp and TfR1, improving Fe metabolism during anemia recovery
Solutions of the Strominger System via Stable Bundles on Calabi-Yau Threefolds
We prove that a given Calabi-Yau threefold with a stable holomorphic vector
bundle can be perturbed to a solution of the Strominger system provided that
the second Chern class of the vector bundle is equal to the second Chern class
of the tangent bundle. If the Calabi-Yau threefold has strict SU(3) holonomy
then the equations of motion derived from the heterotic string effective action
are also satisfied by the solutions we obtain.Comment: 19 pages, late
Traumatic stifle injury in 72 cats:a multicentre retrospective study
Objectives
The aim of the study was to describe traumatic stifle injury in cats and report complications and long-term outcome.
Methods
The medical records from seven veterinary hospitals of cats treated for traumatic stifle injury were reviewed. Long-term follow-up data were collected from referring veterinarians and using the Feline Musculoskeletal Pain Index, collected from owners.
Results
Seventy-two cats were included in the study. The most common combination of ligament injury involved both cruciate ligaments and the lateral collateral ligament (25.4%). Medial meniscal injury was more common (66.2%) than lateral meniscal injury (59.4%). A temporary transarticular pin was used intraoperatively to aid reduction in 23/73 (31.5%) surgeries. Postoperative immobilisation was applied in 41/72 (56.9%) cats with a mean duration of 4.8 weeks. Short-term complications occurred in 40/64 (62.5%) cats. Long-term complications occurred in seven (17.5%) cats. Overall outcome was excellent in 25/61 (41%) cats, good in 13/61 (21.3%) cats, fair in 11/61 (18%) cats and poor in 12/61 (19.7%) cats. Mean length of follow-up was 29.6 months (range 0.5–204). A significantly poorer outcome was observed in cats with medial meniscal injury and those undergoing revision surgery. Use of a transarticular pin when left in situ for postoperative immobilisation was associated with a poorer outcome (P = 0.043) and a higher risk of complications (P = 0.018). Postoperative immobilisation was not related to outcome.
Conclusions and relevance
Traumatic stifle injury in cats can lead to rupture of multiple ligaments causing significant instability of the joint. Surgical treatment is associated with a high rate of short-term complications, although long-term outcome may still be good to excellent in the majority of cats (62.3%). In cats where follow-up was available, postoperative immobilisation had no positive effect on outcome and may not be required. Leaving a transarticular pin for postoperative immobilisation is not recommended as it was significantly associated with a poorer outcome and a higher complication rate
Stability data, irregular connections and tropical curves
We study a class of meromorphic connections nabla(Z) on P^1, parametrised by the central charge Z of a stability condition, with values in a Lie algebra of formal vector fields on a torus. Their definition is motivated by the work of Gaiotto, Moore and Neitzke on wall-crossing and three-dimensional field theories. Our main results concern two limits of the families nabla(Z) as we rescale the central charge Z to RZ. In the R to 0 ``conformal limit'' we recover a version of the connections introduced by Bridgeland and Toledano Laredo (and so the Joyce holomorphic generating functions for enumerative invariants), although with a different construction yielding new explicit formulae. In the R to infty ``large complex structure" limit the connections nabla(Z) make contact with the Gross-Pandharipande-Siebert approach to wall-crossing based on tropical geometry. Their flat sections display tropical behaviour, and also encode certain tropical/relative Gromov-Witten invariants
LSST Science Book, Version 2.0
A survey that can cover the sky in optical bands over wide fields to faint
magnitudes with a fast cadence will enable many of the exciting science
opportunities of the next decade. The Large Synoptic Survey Telescope (LSST)
will have an effective aperture of 6.7 meters and an imaging camera with field
of view of 9.6 deg^2, and will be devoted to a ten-year imaging survey over
20,000 deg^2 south of +15 deg. Each pointing will be imaged 2000 times with
fifteen second exposures in six broad bands from 0.35 to 1.1 microns, to a
total point-source depth of r~27.5. The LSST Science Book describes the basic
parameters of the LSST hardware, software, and observing plans. The book
discusses educational and outreach opportunities, then goes on to describe a
broad range of science that LSST will revolutionize: mapping the inner and
outer Solar System, stellar populations in the Milky Way and nearby galaxies,
the structure of the Milky Way disk and halo and other objects in the Local
Volume, transient and variable objects both at low and high redshift, and the
properties of normal and active galaxies at low and high redshift. It then
turns to far-field cosmological topics, exploring properties of supernovae to
z~1, strong and weak lensing, the large-scale distribution of galaxies and
baryon oscillations, and how these different probes may be combined to
constrain cosmological models and the physics of dark energy.Comment: 596 pages. Also available at full resolution at
http://www.lsst.org/lsst/sciboo
Specific Recognition of p53 Tetramers by Peptides Derived from p53 Interacting Proteins
Oligomerization plays a major role in regulating the activity of many proteins, and in modulating their interactions. p53 is a homotetrameric transcription factor that has a pivotal role in tumor suppression. Its tetramerization domain is contained within its C-terminal domain, which is a site for numerous protein-protein interactions. Those can either depend on or regulate p53 oligomerization. Here we screened an array of peptides derived from proteins known to bind the tetrameric p53 C-terminal domain (p53CTD) and identified ten binding peptides. We quantitatively characterized their binding to p53CTD using fluorescence anisotropy. The peptides bound tetrameric p53CTD with micromolar affinities. Despite the high charge of the binding peptides, electrostatics contributed only mildly to the interactions. NMR studies indicated that the peptides bound p53CTD at defined sites. The most significant chemical shift deviations were observed for the peptides WS100B(81–92), which bound directly to the p53 tetramerization domain, and PKCα(281–295), which stabilized p53CTD in circular dichroism thermal denaturation studies. Using analytical ultracentrifugation, we found that several of the peptides bound preferentially to p53 tetramers. Our results indicate that the protein-protein interactions of p53 are dependent on the oligomerization state of p53. We conclude that peptides may be used to regulate the oligomerization of p53
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