Search results for " function"
showing 10 items of 9395 documents
Unveiling the Different Reactivity of Bent and Linear Three-Atom-Components Participating in [3 + 2] Cycloaddition Reactions
2021
The reactivity of a series of pairs of bent and linear three-atom-component (B-TACs and L-TACs) participating in [3 + 2] cycloaddition (32CA) reactions towards ethylene and electrophilic dicyanoethylene (DCE) have been studied within the Molecular Electron Density Theory. While the pseudodiradical structure of B-TACs changes to that of pseudoradical or carbenoid L-TACs upon dehydrogenation, zwitterionic B-TACs remain unchanged. Conceptual Density Functional Theory (CDFT) indices characterize five of the nine TACs as strong nucleophiles participating in polar reactions towards electrophilic ethylenes. The activation energies of the 32CA reactions with electrophilic DCE range from 0.5 to 22.0…
Effect of dual blockade of renin-angiotensin system on TGF beta 1 and left ventricular structure and function in hypertensive patients
2007
The effects of 24 weeks losartan and ramipril treatment,both alone and in combination, on left ventricular mass (LVM), circulating transforming growth factor b1(TGFb1), procollagen type I (PIP) and III (PIIIP), havebeen evaluated in hypertensive (HT) patients. A total of 57 HT with stage 1 and 2 essential hypertension were included. After 4 weeks run in, a randomized double blind, three arms, double dummy, independent trial was used. All HT patients were randomly allocated to three treatment arms consisting of losartan (50 mg/daily),ramipril (5 mg/ daily) and combined (losartan 50 mg/daily plus ramipril 5 mg/daily) for 24 weeks. TGFb1, PIP and PIIIP, LVM, LVM/h 2.7 and other echocardiograph…
Reading changes in children and adolescents with dyslexia after transcranial direct current stimulation.
2016
Noninvasive brain stimulation offers the possibility to induce changes in cortical excitability and it is an interesting option as a remediation tool for the treatment of developmental disorders. This study aimed to investigate the effect of transcranial direct current stimulation (tDCS) on reading and reading-related skills of children and adolescents with dyslexia. Nineteen children and adolescents with dyslexia performed different reading and reading-related tasks (word, nonword, and text reading; lexical decision; phonemic blending; verbal working memory; rapid automatized naming) in a baseline condition without tDCS and after 20 min of exposure to three different tDCS conditions: left …
Stress Echocardiography and Strain in Aortic Regurgitation (SESAR protocol): Left ventricular contractile reserve and myocardial work in asymptomatic…
2020
Objectives: To analyze left ventricular (LV) myocardial deformation and contractile reserve (CR) in asymptomatic patients with severe aortic regurgitation (AR) at rest and during exercise, and their correlation with functional capacity. Background: The natural history of chronic AR is characterized by a prolonged silent phase before onset of symptoms and overt LV dysfunction. Assessment of LV systolic function and contractile reserve has an important role in the decision-making of AR asymptomatic patients. Methods: Standard echo, lung ultrasound, and LV 2D speckle tracking strain were performed at rest and during exercise in asymptomatic patients with severe AR and in age- and sex-comparabl…
Reading data from graphs: a study on the role of language.
2015
International audience; The work described in this paper is framed in a larger study focused on written argumentations produced by university students in tasks regarding graphs, conversions between graphs and their analytic properties and relations among different graphs. Using the functional linguistics framework, we analyse difficulties related to an examination task on functions and their derivatives. The use of colloquial and literate registers in mathematics problem solving is the lens through which we analyse and discuss the errors. We draw attention to the difficulties concerning the use of literate registers and how these difficulties influence the errors in the interpretations of t…
RELATIONSHIP BETWEEN ASYMPTOMATIC HYPERURICEMIA AND RENAL FUNCTION DECLINE IN HYPERTENSIVE SUBJECTS.
2013
Introduction: It is well known that the deposition of uric acid crystals exert direct toxic effect on the renal parenchyma and vasculature. Both experimental and some clinical studies suggest the possibility that an increased uric acid level can lead to kidney disease even without deposition of uric acid crystals. However, other studies yielded conflicting results, especially regarding the role of uric acid in the progression of established kidney disease. Aim: To evaluate retrospectively the relationship between asymptomatic hyperuricemia and renal function decline in non-gouty hypertensive patients. Methods: We enrolled 97 hypertensive subjects, 48 with chronic kidney diseases (CKD) and 4…
The asthma-COPD overlap syndrome (ACOS): hype or reality? That is, a curiosity for the media or an opportunity for physicians?
2014
Asthma-COPD Overlap Syndrome (ACOS) has been recently defined as a new pathological entity. Most studies support a large difference in the pathophysiology of bronchial asthma and chronic obstructive pulmonary disease (COPD). However, there is evidence of an increasing prevalence of patients in whom the two diseases coexist or in which one condition evolves into the other, leading to the pathological condition named ACOS. This occurs mainly in individuals with long-standing asthma, especially if also current or former-smokers. Indeed, epidemiological studies show that aging is one of the main risk factors for ACOS, creating the basis for the two entities to converge on the same subject. It i…
Is mild asthma in real life always in the Green Zone?
2014
Asthma is a chronic inflammatory disease of the airways that is characterized by variable narrowing of the airways and symptoms of intermittent dyspnea, wheezing, and nighttime or early-morning coughing. Asthma is a major health problem throughout the world, affecting an estimated 315 million persons of all ages. Asthma is clinically heterogeneous, and its pathophysiology is complex. For convenience, asthma action plans are often broken down into three zones, usually based on peak flow meter recordings: green, yellow, and red according to the level of lung function impairment. Recent evidence shows that every asthmatic is potentially at risk for severe exacerbation independently of his/her …
An Atom-Economical Approach to Functionalized Single-Walled Carbon Nanotubes: Reaction with Disulfides
2013
Owing to their unique structure, thermal stability, and mechanical and electronic properties, single-walled carbon nanotubes (SWCNTs) have been a subject of continuous and intense interest. However, various applications in many fields, such as molecular electronics, solar cells, and nanomedicine, often require the development of reproducible protocols for the chemical modification of SWCNTs. In fact, one of the main drawbacks of the use of SWCNTs is their tendency to aggregate and intrinsic poor solubility, which prevent their manipulation and limit their potential. To date, several methods have been described for the chemical functionalization of SWCNTs; however, new versatile and reliable…
Optimal recovery of a radiating source with multiple frequencies along one line
2020
We study an inverse problem where an unknown radiating source is observed with collimated detectors along a single line and the medium has a known attenuation. The research is motivated by applications in SPECT and beam hardening. If measurements are carried out with frequencies ranging in an open set, we show that the source density is uniquely determined by these measurements up to averaging over levelsets of the integrated attenuation. This leads to a generalized Laplace transform. We also discuss some numerical approaches and demonstrate the results with several examples.