78 research outputs found

    Three-dimensional transesophageal echocardiography of the atrial septal defects

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    Transesophageal echocardiography has advantages over transthoracic technique in defining morphology of atrial structures. Even though real time three-dimensional echocardiographic imaging is a reality, the off-line reconstruction technique usually allows to obtain higher spatial resolution images. The purpose of this study was to explore the accuracy of off-line three-dimensional transesophageal echocardiography in a spectrum of atrial septal defects by comparing them with representative anatomic specimens

    Gating a single-molecule transistor with individual atoms

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    Transistors, regardless of their size, rely on electrical gates to control the conductance between source and drain contacts. In atomic-scale transistors, this conductance is sensitive to single electrons hopping via individual orbitals1, 2. Single-electron transport in molecular transistors has been previously studied using top-down approaches to gating, such as lithography and break junctions1, 3, 4, 5, 6, 7, 8, 9, 10, 11. But atomically precise control of the gate—which is crucial to transistor action at the smallest size scales—is not possible with these approaches. Here, we used individual charged atoms, manipulated by a scanning tunnelling microscope12, to create the electrical gates for a single-molecule transistor. This degree of control allowed us to tune the molecule into the regime of sequential single-electron tunnelling, albeit with a conductance gap more than one order of magnitude larger than observed previously8, 11, 13, 14. This unexpected behaviour arises from the existence of two different orientational conformations of the molecule, depending on its charge state. Our results show that strong coupling between these charge and conformational degrees of freedom leads to new behaviour beyond the established picture of single-electron transport in atomic-scale transistors

    Can a Multifaceted Intervention Including Motivational Interviewing Improve Medication Adherence, Quality of Life, and Mortality Rates in Older Patients Undergoing Coronary Artery Bypass Surgery? A Multicenter, Randomized Controlled Trial with 18-Month Follow-Up.

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    BACKGROUND: Patients undergoing coronary artery bypass graft (CABG) surgery are required to take a complex regimen of medications for extended periods, and they may have negative outcomes because they struggle to adhere to this regimen. Designing effective interventions to promote medication adherence in this patient group is therefore important. OBJECTIVE: The present study aimed to evaluate the long-term effects of a multifaceted intervention (psycho-education, motivational interviewing, and short message services) on medication adherence, quality of life (QoL), and mortality rates in older patients undergoing CABG surgery. METHODS: Patients aged over 65 years from 12 centers were assigned to the intervention (EXP; n = 144) or treatment-as-usual (TAU; n = 144) groups using cluster randomization at center level. Medication adherence was evaluated using the Medication Adherence Rating Scale (MARS), pharmacy refill rate, and lipid profile; QoL was evaluated using Short Form-36. Data were collected at baseline; 3, 6, and 18 months after intervention. Survival status was followed up at 18 months. Multi-level regressions and survival analyses for hazard ratio (HR) were used for analyses. RESULTS: Compared with patients who received TAU, the MARS, pharmacy refill rate, and lipid profile of patients in the EXP group improved 6 months after surgery (p < 0.01) and remained so 18 months after surgery (p < 0.01). QoL also increased among patients in the EXP group as compared with those who received TAU at 18 months post-surgery (physical component summary score p = 0.02; mental component summary score p = 0.04). HR in the EXP group compared with the TAU group was 0.38 (p = 0.04). CONCLUSION: The findings suggest that a multifaceted intervention can improve medication adherence in older patients undergoing CABG surgery, with these improvements being maintained after 18 months. QoL and survival rates increased as a function of better medication adherence. ClinicalTrials.gov NCT02109523

    Tracking Cats: Problems with Placing Feline Carnivores on ÎŽ18O, ÎŽD Isoscapes

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    Several felids are endangered and threatened by the illegal wildlife trade. Establishing geographic origin of tissues of endangered species is thus crucial for wildlife crime investigations and effective conservation strategies. As shown in other species, stable isotope analysis of hydrogen and oxygen in hair (ÎŽD(h), ÎŽ(18)O(h)) can be used as a tool for provenance determination. However, reliably predicting the spatial distribution of ÎŽD(h) and ÎŽ(18)O(h) requires confirmation from animal tissues of known origin and a detailed understanding of the isotopic routing of dietary nutrients into felid hair.We used coupled ÎŽD(h) and ÎŽ(18)O(h) measurements from the North American bobcat (Lynx rufus) and puma (Puma concolor) with precipitation-based assignment isoscapes to test the feasibility of isotopic geo-location of felidae. Hairs of felid and rabbit museum specimens from 75 sites across the United States and Canada were analyzed. Bobcat and puma lacked a significant correlation between H/O isotopes in hair and local waters, and also exhibited an isotopic decoupling of ÎŽ(18)O(h) and ÎŽD(h). Conversely, strong ÎŽD and ÎŽ(18)O coupling was found for key prey, eastern cottontail rabbit (Sylvilagus floridanus; hair) and white-tailed deer (Odocoileus virginianus; collagen, bone phosphate).Puma and bobcat hairs do not adhere to expected pattern of H and O isotopic variation predicted by precipitation isoscapes for North America. Thus, using bulk hair, felids cannot be placed on ÎŽ(18)O and ÎŽD isoscapes for use in forensic investigations. The effective application of isotopes to trace the provenance of feline carnivores is likely compromised by major controls of their diet, physiology and metabolism on hair ÎŽ(18)O and ÎŽD related to body water budgets. Controlled feeding experiments, combined with single amino acid isotope analysis of diets and hair, are needed to reveal mechanisms and physiological traits explaining why felid hair does not follow isotopic patterns demonstrated in many other taxa

    Varying constants, Gravitation and Cosmology

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    Fundamental constants are a cornerstone of our physical laws. Any constant varying in space and/or time would reflect the existence of an almost massless field that couples to matter. This will induce a violation of the universality of free fall. It is thus of utmost importance for our understanding of gravity and of the domain of validity of general relativity to test for their constancy. We thus detail the relations between the constants, the tests of the local position invariance and of the universality of free fall. We then review the main experimental and observational constraints that have been obtained from atomic clocks, the Oklo phenomenon, Solar system observations, meteorites dating, quasar absorption spectra, stellar physics, pulsar timing, the cosmic microwave background and big bang nucleosynthesis. At each step we describe the basics of each system, its dependence with respect to the constants, the known systematic effects and the most recent constraints that have been obtained. We then describe the main theoretical frameworks in which the low-energy constants may actually be varying and we focus on the unification mechanisms and the relations between the variation of different constants. To finish, we discuss the more speculative possibility of understanding their numerical values and the apparent fine-tuning that they confront us with.Comment: 145 pages, 10 figures, Review for Living Reviews in Relativit

    Parameter induction in continuous univariate distributions: Well-established G families

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    Multi-wavelength characterization of the blazar S5~0716+714 during an unprecedented outburst phase

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    The BL Lac object S5~0716+714, a highly variable blazar, underwent an impressive outburst in January 2015 (Phase A), followed by minor activity in February (Phase B). The MAGIC observations were triggered by the optical flux observed in Phase A, corresponding to the brightest ever reported state of the source in the R-band. The comprehensive dataset collected is investigated in order to shed light on the mechanism of the broadband emission. Multi-wavelength light curves have been studied together with the broadband Spectral Energy Distributions (SEDs). The data set collected spans from radio, optical photometry and polarimetry, X-ray, high-energy (HE, 0.1 GeV 100 GeV) with MAGIC. The flaring state of Phase A was detected in all the energy bands, providing for the first time a multi-wavelength sample of simultaneous data from the radio band to the VHE. In the constructed SED the \textit{Swift}-XRT+\textit{NuSTAR} data constrain the transition between the synchrotron and inverse Compton components very accurately, while the second peak is constrained from 0.1~GeV to 600~GeV by \textit{Fermi}+MAGIC data. The broadband SED cannot be described with a one-zone synchrotron self-Compton model as it severely underestimates the optical flux in order to reproduce the X-ray to γ\gamma-ray data. Instead we use a two-zone model. The EVPA shows an unprecedented fast rotation. An estimation of the redshift of the source by combined HE and VHE data provides a value of z=0.31±0.02stats±0.05sysz = 0.31 \pm 0.02_{stats} \pm 0.05_{sys}, confirming the literature value. The data show the VHE emission originating in the entrance and exit of a superluminal knot in and out a recollimation shock in the inner jet. A shock-shock interaction in the jet seems responsible for the observed flares and EVPA swing. This scenario is also consistent with the SED modelling
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