1,720,968 research outputs found
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
COVID-19 Outcomes in Patients With Uncontrolled HIV-1 Infection.
No full textIn our experience, COVID-19 in patients with uncontrolled HIV infection was frequently associated with chronic comorbidities and had a clinical presentation comparable with that of both patients with controlled HIV infection and HIV-negative population
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
No progression of subclinical atherosclerosis in HIV-infected patients starting an initial regimen including tenofovir alafenamide/emtricitabine plus raltegravir, dolutegravir or elvitegravir/cobicistat during a two-year follow-up
No full textObjectives: Cardiovascular disease has become one of the most common comorbidities among HIV-infected patients, but available data about the correlation between antiretroviral drugs and progression rate of atherosclerotic disease are still limited. We evaluated the progression rate of carotid atherosclerosis in patients starting an initial antiretroviral regimen including one integrase strand transfer inhibitor (INSTI).Methods: Observational, prospective study involving HIV-1-infected, antiretroviral therapy-naive, adult patients who started an antiretroviral regimen including tenofovir alafenamide/emtricitabine (TAF/FTC) plus raltegravir (RAL group), elvitegravir/cobicistat (EVG/c group), or dolutegravir (DTG group). Patients with known cardiovascular disease or diabetes mellitus were excluded from the study. The progression rate of atherosclerosis has been assessed by carotid Doppler ultrasonography at baseline and after 24 months.Results: Overall, 102 patients were enrolled into the study: 73 males, with mean age of 48.7 years: 32, 36 and 34 patients were included in the RAL, EVG/c and DTG groups, respectively. The baseline features of the enrolled patients were comparable across the three groups. At 24 months, the mean intima-media thickness (IMT) increase at the carotid bifurcation was 0.026 mm in the RAL group, 0.029 mm in EVG/c group and 0.032 mm in DTG group. The mean IMT increases after 24 months were comparable across the three groups and statistically not significant in all the evaluated anatomical sites.Conclusions: The initial antiretroviral therapy with TAF/FTC plus RAL, EVG/c or DTG for 24 months led to a comparable and not significant effect on the progression rate of carotid atherosclerosis
Current developments of A(2a) adenosine receptor antagonists
No full textadenosine regulates a wide range of physiological functions through specific cell membrane receptors. On the basis of pharmacological studies and molecular cloning, four distinct adenosine receptors have been identified and classified as A1, A2a, A2b and A3. These adenosine receptors are members of the G-protein-coupled receptor family. An intense medicinal chemistry effort made over the last 20 years has led to a variety of selective adenosine receptor agonists an antagonists. While all the agonists thus far identified are related to the adenosine structure, the antagonists available belong to different chemical classes. The prototypic antagonists are xanthine derivatives evolved from the natural compounds, caffeine and theophylline. Tipically, they are 8-substituted-1,2,3-trialkylxanthine and are A1 selective antagonists. More recently, 8-styrylxanthines have been found to be selective for A2a receptors. other non-xanthine heterocycles are potent A2a antagonists and possess different degree of selectivity. Selective antagonists are not available yet for A2b and A3 receptors. Given the recent developments of A2a selective antagonists, we have reviewed their chemical structures and biological properties in the attempts to get insight into the emerging class of new interesting compounds. The development of some of the A2a antagonists will provide better understanding of the role of A2a receptors in physiological and pathological states. The compounds appear also to have the potential to be useful for the treatment of cerebral ischemia or neurodegenerative disorders, such as Parkinson's disease
A novel validated UHPLC method for the estimation of rosuvastatin and its complete impurity profile in tablet formulations
Full text linkA key step in the development of medicinal products is the research and validation of selective and sensitive analytical methods for the control of impurities from synthesis and degradation. As most impurities are similar in structure to the drug substance, the achievement of chemo-selective conditions is usually challenging. Herein, a direct and highly selective ultra-high-performance liquid chromatographic method for determining the assay and related substances content in medicinal products containing rosuvastatin calcium salt (RSV) is presented. RSV is used to treat high cholesterol levels and prevent heart attacks and strokes. The most engaging feature of this method was the baseline separation of all organic related substances listed in the European Pharmacopoeia (EP) monograph for the RSV tablets, achieved for the first time in less than 15 min using the Acquity BEH C18 (100 mm × 2.1 mm, 1.7 μm) column under reversed-phase isocratic conditions. The mobile phase adopted for the chemo-selective analysis does not contain buffers but instead contains trifluoroacetic as an acid additive. The chromatographic method was validated according to the guidelines of the International Conference on Harmonization (ICH) and proved to be linear, precise and accurate for determining the content of RSV and related chiral substances in tablet formulations
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