2,491 research outputs found
CTX-M-15–producing Enteroaggregative Escherichia coli as Cause of Travelers’ Diarrhea
Travelers’ diarrhea is a major public health problem. From patients in whom diarrhea developed after travel to India, 5 enteroaggregative Escherichia coli strains carrying β-lactamase CTX-M-15 were identified; 3 belonged to clonal complex sequence type 38. This β-lactamase contributes to the multidrug resistance of enteroaggregative E. coli, thereby limiting therapeutic alternatives
Intravenous single dose of tranexamic acid safely reduces blood loss and the need for transfusion in elderly patients with hip fracture. A randomized double-blinded controlled trial at 1-year follow-up
Background: A hip fracture usually presents significant blood loss in the perioperative period, with a transfusion rate of 20-60%. In order to reduce the complications associated with this procedure, the administration of Tranexamic Acid (TXA) has been implemented in the treatment of perioperative anemia. The objectives were to evaluate the effectiveness and safety of a single dose of intravenous Tranexamic Acid (TXA) in reducing perioperative blood loss and the requirement for transfusion in elderly patients undergoing hip fracture surgery within one postoperative year. Methods: A double-blind randomized controlled trial was conducted on 129 patients with hip fractures. After randomization, at the start of the surgery, 65 patients received a single dose of 1 gram of intravenous TXA (TXA group), and 64 received a placebo (placebo group). The primary effectiveness outcomes were the total blood loss and transfusion rate. The primary safety outcome was the rate of thromboembolic events. Data on surgical or medical infection, readmission and death were also collected. Results: The TXA group had a significant decrease in blood loss (p = 0.006) and requirement for transfusion (p < 0.001) compared with the placebo group. Likewise, there were no thromboembolic events in the TXA group and seven in the placebo group (p = 0.006). Mortality within 1-year postoperatively was not significantly different (p = 0.115). Conclusion: Using a single dose of intravenous TXA at the start of the surgery significantly reduces blood loss and the requirement for transfusion without increasing the risk of thromboembolic events or mortality within 1-year postoperatively in patients with hip fracture undergoing surgery. Registration number: NCT03211286. https://clinicaltrials.gov/ct2/show/NCT03211286. Level of evidence: I
The Milky Way: An Exceptionally Quiet Galaxy; Implications for the formation of spiral galaxies
[Abridged]We compare both the Milky Way and M31 galaxies to local external
disk galaxies within the same mass range, using their relative locations in the
planes formed by V_flat versus M_K, j_disk, and the average Fe abundance of
stars in the galaxy outskirts. We find, for all relationships, that the MW is
systematically offset by ~ 1 sigma, showing a significant deficiency in stellar
mass, in angular momentum, in disk radius and [Fe/H] in the stars in its
outskirts at a given V_flat. On the basis of their location in the M_K, V_flat,
and R_d volume, the fraction of spirals like the MW is 7+/-1%, while M31
appears to be a "typical'' spiral. Our Galaxy appears to have escaped any
significant merger over the last ~10 Gyrs which may explain why it is deficient
by a factor 2 to 3 in stellar mass, angular momentum and outskirts metallicity
and then, unrepresentative of the typical spiral. As with M31, most local
spirals show evidence for a history shaped mainly by relatively recent merging.
We conclude that the standard scenario of secular evolution is generally unable
to reproduce the properties of most (if not all) spiral galaxies. However, the
so-called "spiral rebuilding'' scenario proposed by Hammer et al. 2005 is
consistent with the properties of both distant galaxies and of their
descendants - the local spirals.Comment: 14 pages, 6 figures, to appear in Ap
Multimerization of Zika Virus-NS5 Causes Ciliopathy and Forces Premature Neurogenesis
Zika virus (ZikV) is a flavivirus that infects neural tissues, causing congenital microcephaly. ZikV has evolved multiple mechanisms to restrict proliferation and enhance cell death, although the underlying cellular events involved remain unclear. Here we show that the ZikV-NS5 protein interacts with host proteins at the base of the primary cilia in neural progenitor cells, causing an atypical non-genetic ciliopathy and premature neuron delamination. Furthermore, in human microcephalic fetal brain tissue, ZikV-NS5 persists at the base of the motile cilia in ependymal cells, which also exhibit a severe ciliopathy. Although the enzymatic activity of ZikV-NS5 appears to be dispensable, the amino acids Y25, K28, and K29 that are involved in NS5 oligomerization are essential for localization and interaction with components of the cilium base, promoting ciliopathy and premature neurogenesis. These findings lay the foundation for therapies that target ZikV-NS5 multimerization and prevent the developmental malformations associated with congenital Zika syndrome.The work in E.M.’s laboratory was supported by grants BFU2016-77498-P, BFU2016-77498-P, and La Maratò de TV3 foundation 201833-10. M.S. holds a Ramón Y Cajal fellowship (RYC2018-025379-I). J.B.-A is a recipient of a BES-2017-080050 PhD scholarship. The work in N.V.’s laboratory was supported by grants BIO2017-83906-P, Maria de Maeztu Unit of Excellence MDM-2014-0435 (MCIU), and La Maratò de TV3 foundation 201833-10. The work in N.A.’s laboratory was supported by NIH/NINDS R00NS089859 and IDDRC-NPDA (CHOP/Penn)
Comparison of Functional Outcomes Between the First and Second Knee in Staged Bilateral Total Knee Arthroplasty With Diverse Intervals Between Stages
Background: The objective of the study was to analyze if the length of interval time between stages influenced functional and quality of life outcomes in patients with staged bilateral primary total knee arthroplasty (TKA). Methods: This is a retrospective comparative study between 93 patients with an interval between stages of 6-8 months (6-month group), 112 of 12-14 months (1-year group), and 108 of 24-26 months (2-year group). Outcome variables were Knee Society scores, Western Ontario and McMaster Universities, Short Form, and patient satisfaction. Results: Overall, the mean follow-up for the first TKA was 8.2 (range, 7-10) years, and for the second TKA, 6.7 (range, 5-10) years. At last follow-up, functional and patient-related outcomes were similar for both knees, regardless of the interval. However, mental score and patient satisfaction were significantly better for the second than for the first TKA in the 2-year group. Age did not correlate significantly with the functional scores but was significantly correlated with the mental score. Conclusion: The performing staged bilateral TKA with a wide interval between surgeries provided equivalent functional outcomes and quality of life for both knees. Postoperative outcomes were not affected by the length of the time interval between procedures or age. Our results can help the surgeon to inform the patients reliably about what they can expect in the delay of a second knee replaced. Thus, patients could make an informed decision
Monitoring the Formation of Amyloid Oligomers Using Photoluminescence Anisotropy
The formation of oligomeric soluble aggregates is related to the toxicity of amyloid peptides and proteins. In this manuscript, we report the use of a ruthenium polypyridyl complex ([Ru(bpy)2(dpqp)]2+) to track the formation of amyloid oligomers at different times using photoluminescence anisotropy. This technique is sensitive to the rotational correlation time of the molecule under study, which is consequently related to the size of the molecule. [Ru(bpy)2(dpqp)]2+ presents anisotropy values of zero when free in solution (due to its rapid rotation and long lifetime) but larger values as the size and concentration of amyloid-β (Aβ) oligomers increase. Our assays show that Aβ forms oligomers immediately after the assay is started, reaching a steady state at ∼48 h. SDS–PAGE, DLS, and TEM were used to confirm and characterize the formation of oligomers. Our experiments show that the rate of formation for Aβ oligomers is temperature dependent, with faster rates as the temperature of the assay is increased. The probe was also effective in monitoring the formation of α-synuclein oligomers at different timesAAM thanks the Welch Foundation (Grant C-1743) and JM thanks AEI (SAF2017-89890-R), ERC (DYNAP-677786) and HFSP (RGY0066/2017) for financial supportS
The Mass-Metallicity relation explored with CALIFA: I. Is there a dependence on the star formation rate?
We present the results on the study of the global and local M-Z relation
based on the first data available from the CALIFA survey (150 galaxies). This
survey provides integral field spectroscopy of the complete optical extent of
each galaxy (up to 2-3 effective radii), with enough resolution to separate
individual HII regions and/or aggregations. Nearly 3000 individual HII
regions have been detected. The spectra cover the wavelength range between
[OII]3727 and [SII]6731, with a sufficient signal-to-noise to derive the oxygen
abundance and star-formation rate associated with each region. In addition, we
have computed the integrated and spatially resolved stellar masses (and surface
densities), based on SDSS photometric data. We explore the relations between
the stellar mass, oxygen abundance and star-formation rate using this dataset.
We derive a tight relation between the integrated stellar mass and the
gas-phase abundance, with a dispersion smaller than the one already reported in
the literature (0.07 dex). Indeed, this
dispersion is only slightly larger than the typical error derived for our
oxygen abundances. However, we do not find any secondary relation with the
star-formation rate, other than the one induced due to the primary relation of
this quantity with the stellar mass. We confirm the result using the 3000
individual HII regions, for the corresponding local relations.
Our results agree with the scenario in which gas recycling in galaxies, both
locally and globally, is much faster than other typical timescales, like that
of gas accretion by inflow and/or metal loss due to outflows. In essence,
late-type/disk dominated galaxies seem to be in a quasi-steady situation, with
a behavior similar to the one expected from an instantaneous
recycling/closed-box model.Comment: 19 Pages, 8 figures, Accepted for Publishing in Astronomy and
Astrophysics (A&A
CALIFA : a diameter-selected sample for an integral field spectroscopy galaxy survey
JMA acknowledges support from the European Research Council Starting Grant (SEDmorph; P.I. V. Wild).We describe and discuss the selection procedure and statistical properties of the galaxy sample used by the Calar Alto Legacy Integral Field Area (CALIFA) survey, a public legacy survey of 600 galaxies using integral field spectroscopy. The CALIFA "mother sample" was selected from the Sloan Digital Sky Survey (SDSS) DR7 photometric catalogue to include all galaxies with an r-band isophotal major axis between 45 '' and 79 : 2 '' and with a redshift 0 : 005 M-r > -23 : 1 and over a stellar mass range between 10(9.7) and 10(11.4) M-circle dot. In particular, within these ranges, the diameter selection does not lead to any significant bias against - or in favour of - intrinsically large or small galaxies. Only below luminosities of M-r = -19 (or stellar masses <10(9.7) M-circle dot) is there a prevalence of galaxies with larger isophotal sizes, especially of nearly edge-on late-type galaxies, but such galaxies form <10% of the full sample. We estimate volume-corrected distribution functions in luminosities and sizes and show that these are statistically fully compatible with estimates from the full SDSS when accounting for large-scale structure. For full characterization of the sample, we also present a number of value-added quantities determined for the galaxies in the CALIFA sample. These include consistent multi-band photometry based on growth curve analyses; stellar masses; distances and quantities derived from these; morphological classifications; and an overview of available multi-wavelength photometric measurements. We also explore different ways of characterizing the environments of CALIFA galaxies, finding that the sample covers environmental conditions from the field to genuine clusters. We finally consider the expected incidence of active galactic nuclei among CALIFA galaxies given the existing pre-CALIFA data, finding that the final observed CALIFA sample will contain approximately 30 Sey2 galaxies.Peer reviewe
CALIFA, the Calar Alto Legacy Integral Field Area survey: I. Survey presentation
We present here the Calar Alto Legacy Integral Field Area (CALIFA) survey,
which has been designed to provide a first step in this direction.We summarize
the survey goals and design, including sample selection and observational
strategy.We also showcase the data taken during the first observing runs
(June/July 2010) and outline the reduction pipeline, quality control schemes
and general characteristics of the reduced data. This survey is obtaining
spatially resolved spectroscopic information of a diameter selected sample of
galaxies in the Local Universe (0.005< z <0.03). CALIFA has been
designed to allow the building of two-dimensional maps of the following
quantities: (a) stellar populations: ages and metallicities; (b) ionized gas:
distribution, excitation mechanism and chemical abundances; and (c) kinematic
properties: both from stellar and ionized gas components. CALIFA uses the PPAK
Integral Field Unit (IFU), with a hexagonal field-of-view of
\sim1.3\sq\arcmin', with a 100% covering factor by adopting a three-pointing
dithering scheme. The optical wavelength range is covered from 3700 to 7000
{\AA}, using two overlapping setups (V500 and V1200), with different
resolutions: R\sim850 and R\sim1650, respectively. CALIFA is a legacy survey,
intended for the community. The reduced data will be released, once the quality
has been guaranteed. The analyzed data fulfill the expectations of the original
observing proposal, on the basis of a set of quality checks and exploratory
analysis.
We conclude from this first look at the data that CALIFA will be an important
resource for archaeological studies of galaxies in the Local Universe.Comment: 32 pages, 29 figures, Accepted for publishing in Astronomy and
Astrophysic
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