1,123 research outputs found
Nanoparticle tethered antioxidant response element as a biosensor for oxygen induced toxicity in retinal endothelial cells
Purpose: A novel system, based on biosensor DNA tethered to a nanoparticle, was developed for the treatment of retinopathy of prematurity. Methods: The construction of a five-layered nanoparticle was visualized with gel electrophoresis. Transcriptionally active PCR products (TAP) containing the biosensor sequence, were bioconjugated to the surface of magnetic nanoparticles yielding biosensor tethered magnetic nanoparticles (MNP). The biosensor was based on an enhanced green fluorescent protein (EGFP) reporter gene driven by an enhanced antioxidant response element ( ARE). Image analysis and flow cytometry were used to characterize MNP delivery and biosensor activity. Results: The MNP penetrated dividing and migrating cells more often than quiescent endothelial cells in a wound-healing in vitro assay. Prussian blue staining demonstrated that more cells have nanoparticle cores than are transfected. When compared to naked TAP alone, MNP transfected more cells in a dose dependent manner. Both the biosensor alone and MNP induce gene expression in the presence of hyperoxia, greater than 1.5 fold over normoxic controls. These data also show that the MNP had a signal to noise ratio of 0.5 greater than the plasmid form of the biosensor as demonstrated by flow cytometry. Conclusions: This approach has the potential to allow the endothelial cells of the retinal vasculature to prevent or treat themselves after hyperoxic insult, rather than systemic treatment to protect or treat only the retina
Arabidopsis SABRE and CLASP interact to stabilize cell division plane orientation and planar polarity
The orientation of cell division and the coordination of cell polarity within the plane of the tissue layer (planar polarity) contribute to shape diverse multicellular organisms. The root of Arabidopsis thaliana displays regularly oriented cell divisions, cell elongation and planar polarity providing a plant model system to study these processes. Here we report that the SABRE protein, which shares similarity with proteins of unknown function throughout eukaryotes, has important roles in orienting cell division and planar polarity. SABRE localizes at the plasma membrane, endomembranes, mitotic spindle and cell plate. SABRE stabilizes the orientation of CLASP-labelled preprophase band microtubules predicting the cell division plane, and of cortical microtubules driving cell elongation. During planar polarity establishment, sabre is epistatic to clasp at directing polar membrane domains of Rho-of-plant GTPases. Our findings mechanistically link SABRE to CLASP-dependent microtubule organization, shedding new light on the function of SABRE-related proteins in eukaryotes
a prospective ‘before/after’ cohort study
Objectives Antibiotic resistance has risen dramatically over the past years.
For individual patients, adequate initial antibiotic therapy is essential for
clinical outcome. Computer-assisted decision support systems (CDSSs) are
advocated to support implementation of rational anti-infective treatment
strategies based on guidelines. The aim of this study was to evaluate long-
term effects after implementation of a CDSS. Design This prospective
‘before/after’ cohort study was conducted over four observation periods within
5 years. One preinterventional period (pre) was compared with three
postinterventional periods: directly after intensive implementation efforts
(post1), 2 years (post2) and 3 years (post3) after implementation. Setting
Five anaesthesiological-managed intensive care units (ICU) (one
cardiosurgical, one neurosurgical, two interdisciplinary and one intermediate
care) at a university hospital. Participants Adult patients with an ICU stay
of >48 h were included in the analysis. 1316 patients were included in the
analysis for a total of 12 965 ICU days. Intervention Implementation of a
CDSS. Outcome measures The primary end point was percentage of days with
guideline adherence during ICU treatment. Secondary end points were
antibiotic-free days and all-cause mortality compared for patients with low
versus high guideline adherence. Main results Adherence to guidelines
increased from 61% prior to implementation to 92% in post1, decreased in post2
to 76% and remained significantly higher compared with baseline in post3, with
71% (p=0.178). Additionally, antibiotic-free days increased over study
periods. At all time periods, mortality for patients with low guideline
adherence was higher with 12.3% versus 8% (p=0.014) and an adjusted OR of 1.56
(95% CI 1.05 to 2.31). Conclusions Implementation of computerised regional
adapted guidelines for antibiotic therapy is paralleled with improved
adherence. Even without further measures, adherence stayed high for a longer
period and was paralleled by reduced antibiotic exposure. Improved guideline
adherence was associated with reduced ICU mortality
Highlights from the Pierre Auger Observatory
The Pierre Auger Observatory is the world's largest cosmic ray observatory.
Our current exposure reaches nearly 40,000 km str and provides us with an
unprecedented quality data set. The performance and stability of the detectors
and their enhancements are described. Data analyses have led to a number of
major breakthroughs. Among these we discuss the energy spectrum and the
searches for large-scale anisotropies. We present analyses of our X
data and show how it can be interpreted in terms of mass composition. We also
describe some new analyses that extract mass sensitive parameters from the 100%
duty cycle SD data. A coherent interpretation of all these recent results opens
new directions. The consequences regarding the cosmic ray composition and the
properties of UHECR sources are briefly discussed.Comment: 9 pages, 12 figures, talk given at the 33rd International Cosmic Ray
Conference, Rio de Janeiro 201
The Pierre Auger Observatory III: Other Astrophysical Observations
Astrophysical observations of ultra-high-energy cosmic rays with the Pierre
Auger ObservatoryComment: Contributions to the 32nd International Cosmic Ray Conference,
Beijing, China, August 201
A search for point sources of EeV photons
Measurements of air showers made using the hybrid technique developed with
the fluorescence and surface detectors of the Pierre Auger Observatory allow a
sensitive search for point sources of EeV photons anywhere in the exposed sky.
A multivariate analysis reduces the background of hadronic cosmic rays. The
search is sensitive to a declination band from -85{\deg} to +20{\deg}, in an
energy range from 10^17.3 eV to 10^18.5 eV. No photon point source has been
detected. An upper limit on the photon flux has been derived for every
direction. The mean value of the energy flux limit that results from this,
assuming a photon spectral index of -2, is 0.06 eV cm^-2 s^-1, and no celestial
direction exceeds 0.25 eV cm^-2 s^-1. These upper limits constrain scenarios in
which EeV cosmic ray protons are emitted by non-transient sources in the
Galaxy.Comment: 28 pages, 10 figures, accepted for publication in The Astrophysical
Journa
Update on the correlation of the highest energy cosmic rays with nearby extragalactic matter
Data collected by the Pierre Auger Observatory through 31 August 2007 showed
evidence for anisotropy in the arrival directions of cosmic rays above the
Greisen-Zatsepin-Kuz'min energy threshold, \nobreak{eV}. The
anisotropy was measured by the fraction of arrival directions that are less
than from the position of an active galactic nucleus within 75 Mpc
(using the V\'eron-Cetty and V\'eron catalog). An updated
measurement of this fraction is reported here using the arrival directions of
cosmic rays recorded above the same energy threshold through 31 December 2009.
The number of arrival directions has increased from 27 to 69, allowing a more
precise measurement. The correlating fraction is , compared
with expected for isotropic cosmic rays. This is down from the early
estimate of . The enlarged set of arrival directions is
examined also in relation to other populations of nearby extragalactic objects:
galaxies in the 2 Microns All Sky Survey and active galactic nuclei detected in
hard X-rays by the Swift Burst Alert Telescope. A celestial region around the
position of the radiogalaxy Cen A has the largest excess of arrival directions
relative to isotropic expectations. The 2-point autocorrelation function is
shown for the enlarged set of arrival directions and compared to the isotropic
expectation.Comment: Accepted for publication in Astroparticle Physics on 31 August 201
Atmospheric effects on extensive air showers observed with the Surface Detector of the Pierre Auger Observatory
Atmospheric parameters, such as pressure (P), temperature (T) and density,
affect the development of extensive air showers initiated by energetic cosmic
rays. We have studied the impact of atmospheric variations on extensive air
showers by means of the surface detector of the Pierre Auger Observatory. The
rate of events shows a ~10% seasonal modulation and ~2% diurnal one. We find
that the observed behaviour is explained by a model including the effects
associated with the variations of pressure and density. The former affects the
longitudinal development of air showers while the latter influences the Moliere
radius and hence the lateral distribution of the shower particles. The model is
validated with full simulations of extensive air showers using atmospheric
profiles measured at the site of the Pierre Auger Observatory.Comment: 24 pages, 9 figures, accepted for publication in Astroparticle
Physic
VMÖ – A new strategic transport model for Austria
For the preparation of a new traffic forecast for several time horizons up to the year 2040 and beyond (Verkehrsprognose Österreich, VPÖ 2040+) an up-to-date transport model is necessary. Currently this new national transport model Austria (Verkehrsmodell Österreich, VMÖ) is developed.
The passenger model will be disaggregated tour-based model with 5 basic steps and some extensions for special applications, like for instance tourist traffic. The number of zones will be approximately 6000. In the model a special focus is on incorporating recent trends in mode choice like “park and ride” and other multimodal chains. The freight part of the model will be an Aggregated - Disaggregated - Aggregated (ADA) model with three steps: (1) the results of an input-output-model are transformed into firm-to-firm flows, (2) the choice of shipment size and transport chain is modelled and (3) the OD relations are aggregated for the individual modes and assignment to the networks.
For individual transport with passenger cars and road freight, a quasi-dynamic road transport assignment will be developed. Public transport assignment is based on timetables. For the forecasts of travel demand for future years a pivot-point approach (with the changes) on the base matrices will be applied
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