1,720,973 research outputs found
Vasospastic angina and its relationship with the coronary microcirculation
No full textVasospastic angina is an import cause of chest pain due to coronary artery vasospasm that is related with poor quality of life and can lead to myocardial infarction, arrhythmias and death. Since its first description as "Prinzmetal or variant angina" which was believed to be a focal spam that occurred in non-obstructed epicardial coronary arteries, physician and researchers were gradually, confronted with the clinical reality, and came to the conclusion that the coronary artery vasospasm was considerably more polymorphic than initially described. Although mechanism leading to vasospastic angina are not completely understood today the medical community acknowledges that it exhibit a large variability in clinical practice ranging from focal to diffuse epicardial vasospasm. Main proposed mechanism are impairment of parasympathetic activity, coronary vascular and microvascular dysfunction due to blunted response to nitric oxide endothelium-dependent coronary vasodilatation, increased release of vasoconstricts, and oxidative stress
The variegated histopathological features of atypical lentiginous melanocytic nevi (ALMNs): a single institution experience
No full textBACKGROUND:
Atypical lentiginous melanocytic nevi (ALMNs) are atypical pigmented lesions with histopathological features similar to those of dysplastic nevi, with a lentiginous pattern. Variable histopathological features of ALMNs were observed in our practice.
METHODS:
We described the histopathological features of ALMNs diagnosed in the period 2009- 2015. Our cases were divided into 2 groups: Group 1: ALMNs showing the same histopathological features as previously described in the literature; Group 2: ALMNs with different features.
RESULTS:
29 ALMNs were diagnosed. 2 groups of ALMNs were identified. Group 1 ALMNs showed a constant, mild epidermal acanthosis; frequently, an inflammatory infiltrate and dermal fibrosis, cytological atypia and mild architectural atypia. Group 2 ALMNs showed a constant psoriasis-like acanthosis with a hypercellularity of the rete ridges; cytological atypia was rare, whereas architectural atypia was constantly observed. Immunohistochemistry (MART-1 staining) revealed that the melanocytes were localized at the dermo-epidermal junction in both groups. ALMNs showed a broad spectrum of histopathological features.
CONCLUSIONS:
Our main finding was a constant architectural atypia in all lesions of Group 2. The identification of a unique type of ALMN seems no longer possible. The correct recognition of such benign, though atypical, melanocytic lesions is important in order to avoid an overdiagnosis of cutaneous melanoma and to prevent their potential evolution to the latter
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
Atypical chest pain in ACS. a trap especially for women
No full textNot all acute coronary syndromes (ACS) exhibit the classic symptoms of chest pain. The diagnosis of ACS in patients without typical chest pain is often challenging. These patients are at increased risk for delayed or incorrect diagnosis, less aggressive treatment and high in-hospital mortality. The association between diabetes mellitus and absence of chest pain in ischemic heart disease is established. As well, it is known that women, more frequently than men, have atypical presentation. However, there is a lack of standardization in characterizing the population of patients with ACS and atypical presentation. The identification of other factors influencing and/or related with the absence of chest pain in ACS could be helpful for patients' outcomes. The object of our study was to examine the current literature on the clinical features, other than female gender and diabetes, associated with the atypical presentation of ACS. We found that patients with non-ST-elevation ACS more frequently than patients with ST-elevation myocardial infarction have atypical presentation. Atypical symptoms in aged population are common both among female and male. Subjects with history of comorbidities, specifically heart failure, chronic kidney disease, chronic obstructive pulmonary disease and stroke are less likely to report chest pain as chief complain of ACS
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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