1,720,961 research outputs found
Characteristics of the radial peripapillary capillary network in patients with COVID-19 based on optical coherence tomography angiography: a literature review
No full textPurpose: This review aimed to evaluate the significance of assessing radial peripheral capillary (RPC) network parameters by optical coherence tomography angiography (OCTA) in patients with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection confirmed by polymerase chain reaction.
Methods: A literature search was conducted in the PubMed database to select high-quality reviews and original articles on the use of OCTA for visualizing the RPC network and calculating RPC parameters.
Results: The study revealed that systemic hypoxia, hypercoagulable state, and inflammation affect the RPC network in patients with coronavirus disease 2019 (COVID-19). Reduced RPC parameters were observed early in the course of SARS-CoV-2 infection and after several months of follow-up. Additionally, there was a correlation between reduced RPC parameters and subsequent thinning of the retinal nerve fiber layer.
Conclusions: The OCTA examination of the retina and optic disc should be considered in patients with a history of COVID-19 to assess the impact of systemic hypoxia and inflammation on ocular function. Follow-up assessment of these patients is also necessary to understand the potential consequences of ischemia affecting the optic nerve, retina, and choroid
Ocular microvascular changes in COVID-19 : role of hypoxia, D-dimer, IL-6 and systemic treatment
No full textBackgroundThe severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been associated with endothelial dysfunction, which may also compromise the microcirculation within ocular tissues. This prospective study evaluated associations between radial peripapillary capillary (RPC) vessel density (VD) and systemic treatment, age, hypoxia, D-dimer, and interleukin-6 (IL-6) levels in patients recovering from coronavirus disease 2019 (COVID-19) related pneumonia.MethodsSixty-three individuals who were admitted to the hospital due to COVID-19 bilateral pneumonia underwent ophthalmic examination two months post-discharge. RPC VD was measured using optical coherence tomography angiography. Associations with age, arterial hypertension, and systemic treatment (dexamethasone, remdesivir, and oxygen therapy), oxygen saturation, D-dimer, and IL-6 levels were evaluated. The control group comprised 43 control participants with no history of COVID-19 who attended routine ophthalmic examinations.ResultsNo ophthalmic abnormalities were detected. RPC VD did not differ significantly with hypertension or systemic treatment with dexamethasone and remdesivir. However, patients receiving oxygen therapy had higher RPC VD. A borderline inverse correlation was observed between inferior RPC VD and age. There were no correlations between RPC VD and oxygen saturation. Significant inverse correlations were found between nasal RPC and mean RPC with D-dimer levels and between inferior RPC VD and IL-6 levels. No significant differences in RPC parameters were observed when comparing the COVID-19 group with controls.ConclusionsHypertension or systemic treatment had no significant effect on RCP VD. However, VD in specific RPC areas correlated inversely with D-dimer and IL-6 levels, highlighting the need for monitoring peripapillary microvasculature for potential long-term ocular effects of COVID-19
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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