3,363 research outputs found
Systematic review and meta-analysis of optimal P2Yââ blockade in dual antiplatelet therapy for patients with diabetes with acute coronary syndrome
Background: Patients with diabetes are at increased risk of acute coronary syndromes (ACS) and their mortality and morbidity outcomes are significantly worse following ACS events, independent of other comorbidities. This systematic review sought to establish the optimum management strategy with focus on P2Yââ blockade in patients with diabetes with ACS. Methods: MEDLINE (1946 to present) and EMBASE (1974 to present) databases, abstracts from major cardiology conferences and previously published systematic reviews were searched to June 2014. Relevant randomised control trials with clinical outcomes for P2Yââ inhibitors in adult patients with diabetes with ACS were scrutinised independently by 2 authors with applicable data was extracted for primary composite end point of cardiovascular death, myocardial infarction (MI) and stroke; enabling calculation of relative risks with 95% CI with subsequent direct and indirect comparison. Results: Four studies studied clopidogrel in patients with diabetes, with two (3122 patients) having primary outcome data showing superiority of clopidogrel against placebo with RR0.84 (95% CI 0.72â0.99). Irrespective of management strategy, the newer agents prasugrel (2 studies) and ticagrelor (1 study) had a lower primary event rate compared with clopidogrel; RR 0.80 (95% CI 0.66 to 0.97) and RR 0.89 (95% CI 0.77 to 1.02), respectively. When ticagrelor was indirectly compared with prasugrel, there was a trend to an improved primary outcome with prasugrel (RR 1.11 (95% CI 0.94 to 1.31)) particularly in those managed with percutaneous coronary intervention (PCI) (RR 1.23 (95% CI 0.95 to 1.59)). Prasugrel demonstrated a statistical superiority with prevention of further MI with RR 1.48 (95% CI 1.11 to 1.97). This was not at the expense of increased major thrombolysis in MI (TIMI) bleeding rates RR 0.94 (95% CI 0.59 to 1.51). Conclusions: This meta-analysis shows the addition of a P2Yââ inhibitor is superior to placebo, with a trend favouring the use of prasugrel in patients with diabetes with ACS, particularly those undergoing PCI
Using Mobile Phones to Improve Vaccination Uptake in 21 Low- and Middle-Income Countries: Systematic Review
Background: The benefits of vaccination have been comprehensively proven, however disparities in coverage persist due to poor health system management, limited resources and parental knowledge and attitudes. Evidence suggests that health interventions that engage local parties in communication strategies improve vaccination uptake. As mobile technology is widely used to improve health communication, mobile health (mHealth) interventions might be used to increase coverage.
Objective: To conduct a systematic review of the available literature on the use of mHealth to improve vaccination in low and middle income countries with large numbers of unvaccinated children.
Methods: In February 2017, MEDLINE, Scopus and Web of Science, and three health organization websites; Communication Initiative Network, TechNet-21, and PATH, were searched to identify mHealth intervention studies on vaccination uptake in 21 countries.
Results: Ten peer-reviewed studies and eleven studies from white or grey literature were included. Nine took place in India, three in Pakistan, two each in Malawi and Nigeria, and one each in Bangladesh, Zambia, Zimbabwe and Kenya. Ten peer-reviewed studies and seven white/grey studies demonstrated improved vaccination uptake after interventions, including appointment reminders, mobile phone apps and pre-recorded messages.
Conclusions: While the potential for mHealth interventions to improve vaccination coverage seems clear, the evidence for such interventions is not. The dearth of studies in countries facing the greatest barriers to immunization impedes the prospects for evidence-based policy and practice in these settings.The study was funded by the Medical Research Council, British Heart Foundation, and Homerton College, Cambridge
The HF-CGM study: An analysis of cardiogoniometric axes in patients with cardiac resynchronization therapy
Goal: The HF-CGM is a proof-of-principle study to investigate whether cardiogoniometry (CGM), a three-dimensional electrocardiographic method, can differentiate between pacing modes in patients with cardiac resynchronization therapy (CRT). Methods: At a tertiary cardiology center, CGM recordings were performed using four pacing modes: no pacing; right ventricular (RV) pacing; left ventricular (LV) pacing, and biventricular (BIV) pacing. Three orthogonal CGM planes orientated to the long axis (XY), the frontal plane (YZ), and the short axis (XZ) of the heart were constructed, and the direction of the QRS-axis was calculated for each pacing mode in each plane. During BIV pacing, the direction of CGM QRS-axis was compared between patients with optimal and nonoptimal 12-lead pacing variables. Results: Twenty-two participants (aged 71.5 ± 10.8; 77.3% male, LVEF 29 ± 7%) were consecutively recruited. Only QRS-axis measured in the XY plane could significantly distinguish between all three pacing modes versus no pacing. Mean QRS-axis in the XY plane with pacing off and during RV pacing was leftward and basal; LV pacing was apical; and BIV pacing was rightward and basal. There was a statistically significant difference in the direction of the QRS-axis between patients with optimal versus nonoptimal paced QRS morphology in the XY plane (rightward and basal versus inconsistent). Significance : CGM recorded in the XY plane can accurately detect differences between ventricular pacing sites. It may also be able to identify patients with a CRT device in situ who have optimal response
L1-determined ideals in group algebras of exponential Lie groups
A locally compact group is said to be -regular if the natural map
\Psi:\Prim C^\ast(G)\to\Prim_{\ast} L^1(G) is a homeomorphism with respect to
the Jacobson topologies on the primitive ideal spaces \Prim C^\ast(G) and
\Prim_{\ast} L^1(G). In 1980 J. Boidol characterized the -regular ones
among all exponential Lie groups by a purely algebraic condition. In this
article we introduce the notion of -determined ideals in order to discuss
the weaker property of primitive -regularity. We give two sufficient
criteria for closed ideals of to be -determined. Herefrom
we deduce a strategy to prove that a given exponential Lie group is primitive
-regular. The author proved in his thesis that all exponential Lie groups
of dimension have this property. So far no counter-example is known.
Here we discuss the example , the only critical one in dimension
Generation and Evolution of Spin Entanglement in NRQED
A complete analysis on the generation of spin entanglement from NRQED is
presented. The results of entanglement are obtained with relativistic
correction to the leading order of (v/c)^2. It is shown that to this order the
degree of entanglement of a singlet state does not change under time evolution
whereas the triplet state can change.Comment: 8 pages, 1 figure, to appear in Phys. Rev.
Decomposing oceanic temperature and salinity change using ocean carbon change
As the planet warms due to the accumulation of anthropogenic CO2 in the atmosphere, the interaction of surface ocean carbonate chemistry and the radiative forcing of atmospheric CO2 leads to the global ocean sequestering heat and carbon in a ratio that is nearly constant in time. This ratio has been approximated as globally uniform, enabling the intimately linked patterns of ocean heat and carbon uptake to be derived. Patterns of ocean salinity also change as the Earth system warms due to hydrological cycle intensification and perturbations to airâsea freshwater fluxes. Local temperature and salinity change in the ocean may result from perturbed airâsea fluxes of heat and fresh water (excess temperature, salinity) or from reorganisation of the preindustrial temperature and salinity fields (redistributed temperature, salinity), which are largely due to circulation changes. Here, we present a novel method in which the redistribution of preindustrial carbon is diagnosed and the redistribution of temperature and salinity is estimated using only local spatial information. We demonstrate this technique in the NEMO ocean general circulation model (OGCM) coupled to the MEDUSA-2 biogeochemistry model under an RCP8.5 scenario over 1860â2099. The excess changes (difference between total and redistributed property changes) are thus calculated. We demonstrate that a global ratio between excess heat and temperature is largely appropriate regionally with key regional differences consistent with reduced efficiency in the transport of carbon through the mixed layer base at high latitudes. On centennial timescales, excess heat increases everywhere, with the North Atlantic being a key site of excess heat uptake over the 21st century, accounting for 25â% of the total. Excess salinity meanwhile increases in the Atlantic but is generally negative in other basins, consistent with increasing atmospheric transport of fresh water out of the Atlantic. In the North Atlantic, changes in the inventory of excess salinity are detectable in the late 19th century, whereas increases in the inventory of excess heat do not become significant until the early 21st century. This is consistent with previous studies which find salinification of the subtropical North Atlantic to be an early fingerprint of anthropogenic climate change.
Over the full simulation, we also find the imprint of Atlantic meridional overturning circulation (AMOC) slowdown through significant redistribution of heat away from the North Atlantic and of salinity to the South Atlantic. Globally, temperature change at 2000âm is accounted for by both redistributed and excess heat, but for salinity the excess component accounts for the majority of changes at the surface and at depth. This indicates that the circulation variability contributes significantly less to changes in ocean salinity than to heat content.
By the end of the simulation excess heat is the largest contribution to density change and steric sea level rise, while excess salinity greatly reduces spatial variability in steric sea level rise through density compensation of excess temperature patterns, particularly in the Atlantic. In the Atlantic, redistribution of the preindustrial heat and salinity fields also produces generally compensating changes in sea level, though this compensation is less clear elsewhere.
The regional strength of excess heat and salinity signals grows through the model run in response to the evolving forcing. In addition, the regional strength of the redistributed temperature and salinity signals also grows, indicating increasing circulation variability or systematic circulation change on timescales of at least the model run
Cardiogoniometry compared to fractional flow reserve at identifying physiologically significant coronary stenosis: The Cardioflow Study
Cardiogoniometry (CGM) is method of 3-dimensional electrocardiographic assessment which has been shown to identify patients with angiographically defined, stable coronary artery disease (CAD). However, angiographic evidence of CAD, does not always correlate to physiologically significant disease. The aim of our study was to assess the ability of CGM to detect physiologically significant coronary stenosis defined by fractional flow reserve (FFR). In a tertiary cardiology centre, elective patients with single vessel CAD were enrolled into a prospective double blinded observational study. A baseline CGM recording was performed at rest. A second CGM recording was performed during the FFR procedure, at the time of adenosine induced maximal hyperaemia. A significant CGM result was defined as an automatically calculated ischaemia score < 0 and a significant FFR ratio was defined as < 0.80. Measures of diagnostic performance (including sensitivity and specificity) were calculated for CGM at rest and during maximal hyperaemia. Forty-five patients were included (aged 61.1 ± 11.0; 60.0% male), of which eighteen (40%) were found to have significant CAD when assessed by FFR. At rest, CGM yielded a sensitivity of 33.3% and specificity of 63.0%. At maximal hyperaemia the sensitivity and specificity of CGM was 71.4 and 50.0% respectively. The diagnostic performance of CGM to detect physiologically significant stable CAD is poor at rest. Although, the diagnostic performance of CGM improves substantially during maximal hyperaemia, it does not reach sufficient levels of accuracy to be used routinely in clinical practice
Gas flows around 2 young stellar clusters in NGC2264
Observations of the dust and gas toward two young stellar clusters, IRS1 and
IRS2, in the NGC2264 star forming region are presented. Continuum emission is
used to locate the dusty envelopes around the clusters and individual
protostars within and line emission from the J=3-2 transitions of HCO+ and
H13CO+ is used to diagnose the gas flows around them. The molecular abundance,
velocity centroid and dispersion are approximately constant across the IRS1
clump. With these constraints, the self-absorbed HCO+ lines are modeled as a
large scale collapse, with speed v_in=0.3 km/s and mass infall rate dM/dt=4e-4
Msun/yr, falling onto an expanding central core. The signature of large scale
collapse, with a similar speed and mass infall rate, is also found toward IRS2
but again appears disrupted at small scales. Individual protostars are resolved
in this cluster and their size and velocity dispersion show that the stellar
system is currently bound and no older than 0.5 Myr, but is destined to become
unbound and disperse as the surrounding cloud material is lost.Comment: 13 page, 6 figures (4 color); accepted for publication in the Ap
Camparison of the Hanbury Brown-Twiss effect for bosons and fermions
Fifty years ago, Hanbury Brown and Twiss (HBT) discovered photon bunching in
light emitted by a chaotic source, highlighting the importance of two-photon
correlations and stimulating the development of modern quantum optics . The
quantum interpretation of bunching relies upon the constructive interference
between amplitudes involving two indistinguishable photons, and its additive
character is intimately linked to the Bose nature of photons. Advances in atom
cooling and detection have led to the observation and full characterisation of
the atomic analogue of the HBT effect with bosonic atoms. By contrast, fermions
should reveal an antibunching effect, i.e., a tendency to avoid each other.
Antibunching of fermions is associated with destructive two-particle
interference and is related to the Pauli principle forbidding more than one
identical fermion to occupy the same quantum state. Here we report an
experimental comparison of the fermion and the boson HBT effects realised in
the same apparatus with two different isotopes of helium, 3He (a fermion) and
4He (a boson). Ordinary attractive or repulsive interactions between atoms are
negligible, and the contrasting bunching and antibunching behaviours can be
fully attributed to the different quantum statistics. Our result shows how
atom-atom correlation measurements can be used not only for revealing details
in the spatial density, or momentum correlations in an atomic ensemble, but
also to directly observe phase effects linked to the quantum statistics in a
many body system. It may thus find applications to study more exotic situations
>.Comment: Nature 445, 402 (2007). V2 includes the supplementary informatio
Partition noise and statistics in the fractional quantum Hall effect
A microscopic theory of current partition in fractional quantum Hall liquids,
described by chiral Luttinger liquids, is developed to compute the noise
correlations, using the Keldysh technique. In this Hanbury-Brown and Twiss
geometry, at Laughlin filling factor \nu=1/3, the real time noise correlator
exhibits oscillations which persist over larger time scales than that of an
uncorrelated Hall fluid. The zero frequency noise correlations are negative at
filling factor 1/3 as for bare electrons (anti-bunching), but are strongly
reduced in amplitude. These correlations become positive (bunching) for \nu\leq
1/5, suggesting a tendency towards bosonic behavior.Comment: revised version, curve for time correlations at nu=1/3 adde
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