1,720,980 research outputs found
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
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
Difference in Optical Coherence Tomography Angiography Parameters After SARS-CoV-2 Infection During the Alpha and Delta Variant Dominance Periods
No full textThe SARS-CoV-2 infection manifests with diverse clinical manifestations, with severity potentially influenced by the viral variant. COVID-19 has also been shown to impact ocular microcirculation in some patients, but whether this effect varies by viral lineage remains unclear. This prospective study compared clinical features and ocular parameters assessed via optical coherence tomography angiography (OCTA) in patients recovering from SARS-CoV-2 infections during the dominance of two distinctive viral lineages, Alpha (B.1.1.7) and Delta (B.1.617.2), and compared them to a control group. The following parameters were measured: vessel density (VD) in the superficial capillary plexus (SCP), deep capillary plexus (DCP), and choriocapillaris (CCP) using OCTA, with a manual assessment of the foveal avascular zones in the SCP (FAZs) and DCP (FAZd). A control group was also included. Among 63 patients in the Alpha group and 41 in the Delta group, no eye-related symptoms were reported during the examination. However, the Delta group showed significantly lower VD in the SCP and DCP across all quadrants (p < 0.001–0.039), while the Alpha group showed reduced VD in the foveal CCP (p = 0.005) and significantly wider FAZs and FAZd (p = 0.002 for both). In conclusion, ocular microcirculatory changes differed between the two variants, with Alpha associated with foveal choroidal VD reduction and larger FAZs and Delta linked to lower SCP and DCP VD across multiple regions. These findings highlight the potential for SARS-CoV-2 variants to differentially impact ocular vasculature, underscoring the need for variant-specific follow-up in COVID-19 patients
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
Optical coherence tomography angiography assessment of the optic nerve head in patients hospitalized due to COVID-19 bilateral pneumonia
Full text linkBackground and objectives: We aimed to investigate changes in the radial peripapillary capillary (RPC) network using optical coherence tomography angiography (OCTA) in patients who recovered from coronavirus disease 2019 (COVID-19). Materials and Methods: This was a prospective study of patients hospitalized due to COVID-19 bilateral pneumonia between March and May 2021. The control group included healthy individuals matched for age and sex. Two months after discharge, the patients underwent ophthalmological examination, including optical coherence tomography (OCT) imaging. The RPC network and retinal nerve fiber layer (RNFL) of the optic disc (RNFL optic disc) were automatically evaluated and compared between the study groups. Additionally, the RPC parameters were compared between the men and women in the COVID-19 group, and correlations between the RPC and RNFL optic disc parameters were assessed. Results: A total of 63 patients (120 eyes) with bilateral pneumonia caused by severe acute respiratory syndrome coronavirus 2 infection were examined. No ophthalmic symptoms were reported by the patients. No significant differences were observed in the RPC parameters between the patients from the COVID-19 group and the 43 healthy controls. Moreover, the RPC parameters did not differ between the men and women in the COVID-19 group. A positive correlation was found between the RPC and RNFL optic disc parameters in the COVID-19 patients (p Conclusions: No changes in the RPC network were observed among the patients with COVID-19 bilateral pneumonia in the early period after hospital discharge. However, a longer follow-up is needed to monitor COVID-19–related changes in the microvasculature of the optic nerve head
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
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