The electrochemical oxidation of methanol, ethanol,
n-propanol and
n-butanol has been carried out at the Pt(111) and the stepped Pt(755) and Pt(332) surfaces in sodium hydroxide solution. Special ...attention was paid to the study of the oxygen-containing species generated and adsorbed during surface oxidation. The existence of reversible OH
ad, irreversible OH
ad and PtO species was suggested in the potential region relevant for the alcohol oxidation. The role of these species in the reaction was determined and a dual path mechanism was proposed for the alcohols studied.
A major endeavor of this decade is the direct characterization of young giant exoplanets at high spectral resolution to determine the composition of their atmosphere and infer their formation ...processes and evolution. Such a goal represents a major challenge owing to their small angular separation and luminosity contrast with respect to their parent stars. Instead of designing and implementing completely new facilities, it has been proposed to leverage the capabilities of existing instruments that offer either high contrast imaging or high dispersion spectroscopy, by coupling them using optical fibers. In this work we present the implementation and first on-sky results of the HiRISE instrument at the very large telescope (VLT), which combines the exoplanet imager SPHERE with the recently upgraded high resolution spectrograph CRIRES using single-mode fibers. The goal of HiRISE is to enable the characterization of known companions in the \(H\) band, at a spectral resolution of the order of \(R = \lambda/\Delta\lambda = 100\,000\), in a few hours of observing time. We present the main design choices and the technical implementation of the system, which is constituted of three major parts: the fiber injection module inside of SPHERE, the fiber bundle around the telescope, and the fiber extraction module at the entrance of CRIRES. We also detail the specific calibrations required for HiRISE and the operations of the instrument for science observations. Finally, we detail the performance of the system in terms of astrometry, temporal stability, optical aberrations, and transmission, for which we report a peak value of \(\sim\)3.9% based on sky measurements in median observing conditions. Finally, we report on the first astrophysical detection of HiRISE to illustrate its potential.
Background An updated 2016 echocardiographic algorithm for diagnosing left ventricular (LV) diastolic dysfunction (DD) was recently proposed. We aimed to assess the reliability of the 2016 ...echocardiographic LVDD grading algorithm in predicting elevated LV filling pressure and clinical outcomes compared to the 2009 version. Methods We retrospectively identified 460 consecutive patients without atrial fibrillation or significant mitral valve disease who underwent transthoracic echocardiography within 24 hours of elective heart catheterization. LV end-diastolic pressure (LVEDP) and the time constant of isovolumic pressure decay (Tau) were determined. The association between DD grading by 2009 LVDD Recommendations and 2016 Recommendations with hemodynamic parameters and all-cause mortality were compared. Results The 2009 LVDD Recommendations classified 55 patients (12%) as having normal, 132 (29%) as grade 1, 156 (34%) as grade 2, and 117 (25%) as grade 3 DD. Based on 2016 Recommendations, 177 patients (38%) were normal, 50 (11%) were indeterminate, 124 (27%) patients were grade 1, 75 (16%) were grade 2, 26 (6%) were grade 3 DD, and 8 (2%) were cannot determine. The 2016 Recommendations had superior discriminatory accuracy in predicting LVEDP ( P < .001) but were not superior in predicting Tau. During median follow-up of 416 days (interquartile range: 5 to 2004 days), 54 patients (12%) died. Significant DD by 2016 Recommendations was associated with higher risk of mortality ( P = .039, subdistribution HR1.85 95% CI, 1.03-3.33) in multivariable competing risk regression. Conclusions The grading algorithm proposed by the 2016 LV diastolic dysfunction Recommendations detects elevated LVEDP and poor prognosis better than the 2009 Recommendations.
We present a result on uniform attractivity of the origin for nonlinear time-varying systems. Our theorem generalizes Matrosov's theorem which extends, in a certain manner, Krasovskii-LaSalle's ...invariance principle to the case of general nonlinear time-varying systems. We show the utility of our theorem by analyzing uniform asymptotic stability of the origin for nonholonomic: systems in closed loop with particular smooth time-varying feedbacks previously proposed in the literature.
The large difference between the Planck scale and the electroweak scale, known as the hierarchy problem, is addressed in certain models through the postulate of extra spatial dimensions. A search for ...evidence of extra spatial dimensions in the diphoton channel has been performed using the full set of proton-proton collisions at sqrt(s) = 7 TeV recorded in 2011 with the ATLAS detector at the CERN Large Hadron Collider. This dataset corresponds to an integrated luminosity of 4.9 /fb. The diphoton invariant mass spectrum is observed to be in good agreement with the expected Standard Model background. 95% confidence level lower limits of between 2.52 TeV and 3.92 TeV are set on the Ms scale in the context of the model proposed by Arkani-Hamed, Dimopoulos and Dvali, depending on the number of extra dimensions and the theoretical formalism used. In the context of the Randall--Sundrum model, a lower limit of 1.00 (2.06) TeV at 95% confidence level is set on the mass of the lightest graviton for couplings of k/Mpl = 0.01 (0.1). Combining with the ATLAS dilepton searches based on the 2011 data, the 95% confidence level limit on the Randall--Sundrum graviton mass is further tightened to 1.03 (2.23) TeV for k/Mpl = 0.01 (0.1).
Successful endoscopic sclerotherapy is effective in securing hemostasis for bleeding lesions and remains the first line and only needed therapy for most of the patients (pts), but bleeding reoccurs ...in 10% to 30% pts, and 4% to 14% of the pts die after acute nonvariceal upper gastrointestinal bleeding (UGIB). The need for hospitalization and its duration for all the bleeding pts is still a controversial question.
To create the simple scoring system able to determine low risk pts for rebleeding and mortality by establishing the relative importance of risk factors for rebleeding and mortality after successful endoscopic sclerotherapy of acute nonvariceal UGIB.
Prospective study included 3 15 pts who where admitted to hospital because of acute nonvariceal UGIB. All of them underwent gastroscopy with successful sclerotherapy within 12 hours after the admission. We investigated the episode of rebleeding and death during the initial hospitalization, and analyzed the following parameters: age, gender, drug intake, shock, bleeding stigmata, location of bleeding lesion and comorbidity.
Rebleeding occurred in 53 pts (16.8%) and was determined by shock, bleeding stigmata and comorbidity. Eleven pts (3.5%) died and shock, rebleeding and comorbidity were all independent, statistically significant predictors of pts' mortality. The numerical scores for determination of pts with different risk levels for rebleeding and mortality have been developed using the significant predictors of rebleeding and death. The score values for rebleeding ranged from 3 to 9 and pts with values < or = 4 had low risk of rebleeding. We identified 59 pts (18.7% of all) with score for rebleeding < or = 4. Score values for mortality risk ranged from 3 to 8 and the values < 5 revealed negligible risk of death. In our group we found 290 pts (92.1% of all) with low mortality score values.
Following the successful initial endoscopic sclerotherapy, these scores can help to identify pts with low risk of rebleeding and negligible risk of death, so they can be treated as outpatients.
The paper describes design of the FLUTE system, an intelligent tutoring system in the domain of formal languages and automata. The basic idea of the FLUTE system is a systematic introduction of ...students into the system's domain, in accordance with both the logical structure of the domain and individual background knowledge and learning capabilities of each student. Other intelligent tutoring systems in that domain are not described in the open literature. The knowledge in the FLUTE system is represented starting from ITS ontology that has been defined within a recently developed framework and a model of intelligent tutoring systems, called GET-BITS. A brief overview of the model/framework is also included. The contents that should be presented to the student during tutoring sessions are discussed and logical organization of such contents within the system is described. The system is analyzed in the paper from the pedagogical point of view. Every concept that a student has to learn during a session with FLUTE, the system illustrates by a number of examples. This makes the tutoring process more dynamic and facilitates learning.
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