6,770 research outputs found
Impact of heart rate on myocardial salvage in timely reperfused patients with STSegment elevation myocardial infarction. new insights from cardiovascular magnetic resonance
BACKGROUND: Previous studies evaluating the progression of the necrotic wave in relation to heart rate were carried out only in animal models of ST-elevated myocardial infarction (STEMI). Aim of the study was to investigate changes of myocardial salvage in relation to different heart rates at hospital admission in timely reperfused patients with STEMI by using cardiovascular magnetic resonance (CMR).
METHODS: One hundred-eighty-seven patients with STEMI successfully and timely treated with primary coronary angioplasty underwent CMR five days after hospital admission. According to the heart rate at presentation, patients were subcategorized into 5 quintiles: <55 bpm (group I, n = 44), 55-64 bpm (group II, n = 35), 65-74 bpm (group III, n = 35), 75-84 bpm (group IV, n = 37), â„85 bpm (group V, n = 36). Area at risk, infarct size, microvascular obstruction (MVO) and myocardium salvaged index (MSI) were assessed by CMR using standard sequences.
RESULTS: Lower heart rates at presentation were associated with a bigger amount of myocardial salvage after reperfusion. MSI progressively decreased as the heart rates increased (0.54 group I, 0.46 group II, 0.38 group III, 0.34 group IV, 0.32 group V, p<0.001). Stepwise multivariable analysis showed heart rate, peak troponin and the presence of MVO were independent predictor of myocardial salvage. No changes related to heart rate were observed in relation to area at risk and infarct size.
CONCLUSIONS: High heart rates registered before performing coronary angioplasty in timely reperfused patients with STEMI are associated with a reduction in salvaged myocardium. In particular, salvaged myocardium significantly reduced when heart rate at presentation is â„85 bpm
Navigational style influences eye movement pattern during exploration and learning of an environmental map
During navigation people may adopt three different spatial styles (i.e., Landmark, Route, and Survey). Landmark style (LS) people are able to recall familiar landmarks but cannot combine them with directional information; Route style (RS) people connect landmarks to each other using egocentric information about direction; Survey style (SS) people use a map-like representation of the environment. SS individuals generally navigate better than LS and RS people. Fifty-one college students (20 LS; 17 RS, and 14 SS) took part in the experiment. The spatial cognitive style (SCS) was assessed by means of the SCS test; participants then had to learn a schematic map of a city, and after 5 min had to recall the path depicted on it. During the learning and delayed recall phases, eye-movements were recorded. Our intent was to investigate whether there is a peculiar way to explore an environmental map related to the individual's spatial style. Results support the presence of differences in the strategy used by the three spatial styles for learning the path and its delayed recall. Specifically, LS individuals produced a greater number of fixations of short duration, while the opposite eye movement pattern characterized SS individuals. Moreover, SS individuals showed a more spread and comprehensive explorative pattern of the map, while LS individuals focused their exploration on the path and related targets. RS individuals showed a pattern of exploration at a level of proficiency between LS and SS individuals. We discuss the clinical and anatomical implications of our data
Nanoparticle-based receptors mimic protein-ligand recognition
The self-assembly of a monolayer of ligands on the surface of noble metal nanoparticles dictates the fundamental nanoparticle\u2019s behavior and its functionality. In this combined computational\u2013experimental study, we analyze the structure, organization, and dynamics of functionalized coating thiols in monolayer-protected gold nanoparticles (AuNPs). We explain how functionalized coating thiols self-organize through a delicate and somehow counterintuitive balance of interactions within the monolayer itself and with the solvent. We further describe how the nature and plasticity of these interactions modulate nanoparticle-based chemosensing. Importantly, we found that self-organization of coating thiols can induce the formation of binding pockets in AuNPs. These transient cavities can accommodate small molecules, mimicking protein-ligand recognition, which may explain the selectivity and sensitivity observed for different organic analytes in NMR chemosensing experiments. Thus, our findings advocate for the rational design of tailored coating groups to form specific recognition binding sites on monolayer-protected AuNPs
The Global Electroweak and Higgs Fits in the LHC era
We update the global fit to electroweak precision observables, including the
effect of the latest measurements at hadron colliders of the and top-quark
masses and the effective leptonic weak mixing angle. We comment on the impact
of these measurements in terms of constraints on new physics. We also update
the bounds derived from the fit to the Higgs-boson signal strengths, including
the observables measured at the LHC Run 2, and compare the improvements with
respect to the 7 and 8 TeV results.Comment: 5+1 pages, 3 figures, 2 tables. Prepared for the Proceedings of the
5th LHCP Conference -Shanghai, May 2017- and the EPS-HEP 2017 Conference
-Venice, July 2017. (LHCP version.
Electroweak precision constraints at present and future colliders
We revisit the global fit to electroweak precision observables in the
Standard Model and present model-independent bounds on several general new
physics scenarios. We present a projection of the fit based on the expected
experimental improvements at future colliders, and compare the
constraining power of some of the different experiments that have been
proposed. All results have been obtained with the HEPfit code.Comment: 6 + 1 pages, 4 figures, 6 tables. Minor corrections. Contribution to
the Proceedings of the 38th International Conference on High Energy Physics,
3-10 August 2016, Chicago, U.S.
Electroweak precision observables and Higgs-boson signal strengths in the Standard Model and beyond: present and future
We present results from a state-of-the-art fit of electroweak precision
observables and Higgs-boson signal-strength measurements performed using 7 and
8 TeV data from the Large Hadron Collider. Based on the HEPfit package, our
study updates the traditional fit of electroweak precision observables and
extends it to include Higgs-boson measurements. As a result we obtain
constraints on new physics corrections to both electroweak observables and
Higgs-boson couplings. We present the projected accuracy of the fit taking into
account the expected sensitivities at future colliders.Comment: 34 pages, 30 figures, 23 table
A possible role for selenoprotein glutathione peroxidase (GPx1) and thioredoxin reductases (TrxR1) in thyroid cancer. Our experience in thyroid surgery
Abstract
Background: Oxidative stress is responsible for some alterations in the chemical structure and, consequently, in
the function of proteins, lipids, and DNA. Recent studies have linked oxidative stress to cancers, particularly thyroid
cancer, but the mechanisms remain unclear. Here, we further characterize the role of oxidative stress in thyroid cancer
by analyzing the expression of two selenium antioxidant molecules, glutathione peroxidase (GPx1) and thioredoxin
reductase (TrxR1) in thyroid cancer cells.
Methods: Samples of both healthy thyroid tissue and thyroid tumor were taken for analysis after total thyroidectomy.
The expression of GPx1 and TrxR1 was revealed by Western blot analysis and quantified by densitometric analyses,
while the evaluation of free radicals was performed by Electron Paramagnetic Resonance (EPR)-spin trapping
technique.
Results: Our results show a decrease in the expression of GPx1 and TrxR1 (â 45.7 and â 43.2% respectively, p < 0.01)
in the thyroid cancer cells compared to the healthy cells. In addition, the EPR technique shows an increase of free
radicals in tumor tissue, significantly higher than that found in healthy thyroid tissue (+ 116.3%, p < 0.01).
Conclusions: Our findings underscore the relationship between thyroid cancer and oxidative stress, showing the
imbalance of the oxidant/antioxidant system in thyroid cancer tissue. These results suggest that either the inability to
produce adequate antioxidant defense or an increased consumption of antioxidants, due to the hyper-production of
free radicals, may play a crucial role in thyroid cancer.
Keywords: Oxidative stress, Thyroid cancer, Glutathione peroxidase (GPx1), Thioredoxin reductases (TrxR1), Selenium
enzyme
Global Bayesian Analysis of the Higgs-boson Couplings
We present preliminary results of a bayesian fit to the Wilson coefficients
of the Standard Model gauge invariant dimension-6 operators involving one or
more Higgs fields, using data on electroweak precision observables and Higgs
boson signal strengths.Comment: Based on a talk given by Diptimoy Ghosh in ICHEP 2014, Valenci
Dentate nucleus connectivity in adult patients with multiple sclerosis: functional changes at rest and correlation with clinical features
Background and objective: The dentate nucleus, which is the largest of the cerebellar nuclei, plays a critical role in movement and cognition. The aim of our study was to assess any changes in dentate functional connectivity (FC) in adult relapsing remitting multiple sclerosis (RR-MS) patients and to investigate possible clinical correlates.
Materials and methods: In all, 54 patients and 24 healthy subjects (HS) underwent multimodal magnetic resonance imaging (MRI), including diffusion tensor imaging (DTI), three-dimensional-T1-weighted and resting state (RS) functional images; they also underwent a cognitive evaluation, that is, attention and information processing speed, by means of the Paced Auditory Serial Addition Test (PASAT). Patients were also scored according to Expanded Disability Status Scale (EDSS). RS-MRI data were analysed using FMRIB Software Library (FSL) tools, with the seed-based method to identify dentate FC.
Results: When compared with HS, patients exhibited brain atrophy and widespread DTI abnormalities, as well as greater FC between the dentate nucleus and cortical areas, particularly in the frontal and parietal lobes. Within these areas, FC in patients correlated inversely with clinical impairment. Finally, FC correlated inversely with lesion load and microstructural brain damage.
Conclusion: Our findings indicate that dentate FC at rest is altered in MS patients. Whether these functional changes are induced by the disease and play a compensatory role remains to be established
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