1,721,019 research outputs found
Reactive oxygen metabolites and arterial thrombosis
No full textArterial thrombus formation is the result of complex events which require the interaction of damaged vessel walls with blood cellular elements and coagulation factors, and in which several mediators may play a role. In this context, the role of 'classical' chemical mediators such as thrombin, thromboxane or serotonin in initiating and/or amplifying intravascular thrombus formation is well established. However, it is now being recognized that certain chemical species formed in the metabolism of oxygen may also be involved in the process of arterial thrombosis. This review will focus on recent evidence in this field
Cardiovascular involvement during COVID-19 and clinical implications in elderly patients. A review
No full textSARS-CoV-2 betacoronavirus is responsible for the Corona Virus Disease 2019 (COVID-19) which has relevant pathogenic implications for the cardiovascular system. Incidence and severity of COVID-19 are higher in the elderly population (65 years and older). This may be due to higher frequency of comorbidities, but increased frailty and immunosenescence linked with aging may also contribute. Moreover, in elderly individuals, SARS-CoV-2 may adopt different molecular strategies to strongly impact on cardiac aging that culminate in exacerbating a pro-inflammatory state (cytokine storm activation), which, in turn, may lead to pulmonary vascular endothelialitis, microangiopathy, diffuse thrombosis, myocarditis, heart failure, cardiac arrhythmias, and acute coronary syndromes. All these events are particularly relevant in elderly patients, and deserve targeted cardiovascular treatments and specific management of repurposed drugs against COVID-19. We discuss current evidence about the cardiovascular involvement during COVID-19, and elaborate on clinical implications in elderly patients
New Cyclic Olefin Copolymer for the Preparation of Thermally Responsive Luminescent Films
No full textPolymer films with optical properties as indicators to thermal stress were obtained through the controlled dispersion of moderate amounts (0.1 wt.-%) of the 4,40-bis(2-benzoxazolyl)- stilbene (BBS) dye into a new semicrystalline ethylene-norbornene (E-co-N, N content of 15.3 mol.-%) copolymer characterized by a glass transition temperature (Tg) of about 64 8C. All the pristine films showed optical characteristics com- ing from noninteracting BBS chromophores. In contrast permanent optical changes were detected after film annealing at a T Tg due to the variation of the BBS supramolecular structure. The easy modulation of the optical features of polymer films by thermal perturbations suggests applications as threshold temperature visual indicators in thermoplastic materials
Ethene/4-methyl-1-pentene copolymers by metallocene based catalysts: an insight in 13C NMR assignment
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Effects of Sitagliptin on Lipid Profile in Patients With Type 2 Diabetes Mellitus After 7 Years of Therapy
No full textThe aim of this study was to investigate whether the effects of sitagliptin on lipid profile were maintained even after 7 years of treatment. We treated 591 patients who had not been well controlled by current therapy with the addition of sitagliptin 100 mg/d. Data were compared with those of 612 patients treated with sulfonylureas plus metformin, pioglitazone plus metformin, and pioglitazone plus sulfonylureas. We observed that, compared with patients treated with sulfonylureas plus metformin, patients receiving sitagliptin in addition to metformin experienced a greater decrease of total cholesterol and low-density lipoprotein cholesterol (LDL-C) compared with baseline and with sulfonylureas plus metformin. Compared with patients treated with metformin plus pioglitazone, sitagliptin resulted in a greater reduction of total cholesterol and LDL-C relative to baseline and to metformin plus pioglitazone. We also observed a higher increase of high-density lipoprotein cholesterol (HDL-C) after sitagliptin had been added to pioglitazone, both compared with baseline and to the competitor. Compared with patients treated with pioglitazone plus sulfonylureas, the combination of sitagliptin and sulfonylureas was more effective in reducing LDL-C and in increasing HDL-C. High-sensitivity C-reactive protein was decreased by all pharmacological combinations. We can conclude that the addition of sitagliptin led to a better and more durable improvement of lipid profile compared with sulfonylureas or thiazolidinediones
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