164 research outputs found
Comprehensively identifying Long Covid articles with human-in-the-loop machine learning
A significant percentage of COVID-19 survivors experience ongoing
multisystemic symptoms that often affect daily living, a condition known as
Long Covid or post-acute-sequelae of SARS-CoV-2 infection. However, identifying
scientific articles relevant to Long Covid is challenging since there is no
standardized or consensus terminology. We developed an iterative
human-in-the-loop machine learning framework combining data programming with
active learning into a robust ensemble model, demonstrating higher specificity
and considerably higher sensitivity than other methods. Analysis of the Long
Covid collection shows that (1) most Long Covid articles do not refer to Long
Covid by any name (2) when the condition is named, the name used most
frequently in the literature is Long Covid, and (3) Long Covid is associated
with disorders in a wide variety of body systems. The Long Covid collection is
updated weekly and is searchable online at the LitCovid portal:
https://www.ncbi.nlm.nih.gov/research/coronavirus/docsum?filters=e_condition.LongCovi
Diagnosis of left ventricular diastolic dysfunction in the setting of acute changes in loading conditions
International audienceINTRODUCTION: Conventional pulsed wave Doppler parameters are known to be preload dependent, whereas newly proposed Doppler indices may be less influenced by variations in loading conditions. The aim of the present study was to evaluate the effects of haemodialysis-induced preload reduction on both conventional and new Doppler parameters for the assessment of left ventricular (LV) diastolic function. METHODS: This prospective observational study was conducted in a medical-surgical intensive care unit (ICU) and nephrology department of a teaching hospital. In total, 37 haemodialysis patients with end-stage renal disease (age [mean +/- standard deviation]: 52 +/- 13 years) and eight ventilated ICU patients with acute renal failure receiving vasopressor therapy (age 57 +/- 16 years; Simplified Acute Physiology Score II 51 +/- 17) were studied. Echocardiography was performed before and after haemodialysis. Conventional pulsed wave Doppler indices of LV diastolic function as well as new Doppler indices, including Doppler tissue imaging early diastolic velocities (E' wave) of the septal and lateral portions of the mitral annulus, and propagation velocity of LV inflow at early diastole (Vp) were measured and compared before and after ultrafiltration. RESULTS: The volume of ultrafiltration was greater in haemodialysis patients than in ICU patients (3.0 +/- 1.1 l versus 1.9 +/- 0.9 l; P = 0.005). All conventional pulsed wave Doppler parameters were altered by haemodialysis. In haemodialysis patients, E' velocity decreased after ultrafiltration when measured at the septal mitral annulus (7.1 +/- 2.5 cm/s versus 5.9 +/- 1.7 cm/s; P = 0.0003), but not at its lateral portion (8.9 +/- 3.1 cm/s versus 8.3 +/- 2.6 cm/s; P = 0.37), whereas no significant variation was observed in ICU patients. Vp decreased uniformly after ultrafiltration, the difference being significant only in haemodialysis patients (45 +/- 11 cm/s versus 41 +/- 13 cm/s; P = 0.04). Although of less magnitude, ultrafiltration-induced variations in Doppler parameters were also observed in haemodialysis patients with altered LV systolic function. CONCLUSION: In contrast to other Doppler parameters, Doppler tissue imaging E' maximal velocity measured at the lateral mitral annulus represents an index of LV diastolic function that is relatively insensitive to abrupt and marked preload reduction
Formation of the X-ray line emission spectrum of excimer laser-produced plasmas
Time- and space-integrated emission spectra measurements have been performed in plasma produced by 308 nm wavelength XeCl laser radiation (IL = (4–10)·1012 W/cm2, τ = 10 ns) and by 248 nm wavelength KrF laser pulse train radiation (IL = 5·1015 W/cm2, τ = 7 ps, 16 pulses in train) on CF2 plane target. Theoretical modelling of Lyman series and He-like ion resonance series of fluorine and its fit of experimental data show considerable differences in the absorption of laser radiation in the two plasmas
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