1,720,956 research outputs found
INVERSE RELATIONSHIP BETWEEN CHOROIDAL THICKNESS AND SUBCLINICAL RENAL DAMAGE IN ESSENTIAL HYPERTENSION
No full textThe introduction in last years of advanced techniques of optical coherence
tomography (OCT) has greatly increased our understanding of the choroid, that is
the most important vascular layer of the eye. Our study was aimed to assess
choroidal thickness by using Swept-Source OCT (SS-OCT) in essential hypertensive
patients (EHs) with and without subclinical renal damage (SRD).
We enrolled 100 EHs of which 65 without kidney damage and 35 with SRD. In all the
participants SS-OCT and a routine biochemical workup were performed. Glomerular
filtration rate (GFR) was estimated by the CKD-EPI equation (eGFR). SRD was
defined, by the presence of microalbuminuria or eGFR between 30 and 60
mL/min/1.73 m2. OCT measurements were performed according to the Early
Treatment Diabetic Retinopathy Study (ETDRS) protocol, that divides the macula into
9 subfields. The circular grid consists of 3 concentric rings.
EHs with SRD showed thinner choroidal thicknesses than those without kidney
damage (all p < 0.05), even after adjustment for age. Overall choroidal thickness
correlated significantly and directly with eGFR (r = 0.36) and negatively with urinary
albumin excretion (r = – 0.39). The association of choroidal thickness with SRD was
confirmed in multiple logistic regression analyses once the effect of age, antihypertensive
therapy and triglycerides was accounted for. The odds ratio of having
SRD associated with a standard deviation increase of overall choroidal thickness was
0.43 (0.24–0.75, 95% confidence interval; p = 0.007).
In conclusion, our study confirms the close relationships between changes in ocular
microcirculation and renal dysfunction
Retinal and choroidal vasculature changes associated with chronic kidney disease
No full textPurpose: Retinal and choroidal microvascular changes can be related to renal
impairment in hypertension and chronic kidney disease (CKD). The study examines
the association between retino-choroidal parameters and renal impairment in
hypertensive, non diabetic patients.
Methods: This is a cross-sectional study on Caucasian patients with systemic arterial
hypertension with different levels of renal function. All subjects were studied by blood
chemistry, urine examination, microalbuminuria and blood pressure. Complete eye
examination was completed with SS-OCT and OCTA scans of macular region. Patients
were divided in groups: LowGFR and HighGFR, CKD- and CKD+, according to the
value of glomerular filtrate (GFR) and albuminuria. LowGFR and CKD+ groups
included patients with clinical kidney impairment.
Results: 120 eyes of 120 hypertensive patients were evaluated. Mean retinal thickness
was thinner in CKD+ versus CKD- group (p<0.009). LowGFR and CKD+ groups
showed thinner choroidal values than HighGFR (p<0.02) and CKD- (p<0.001) groups.
OCTA showed lower density in LowGFR than in HighGFR group (p<0.001), and in
CKD+ versus CKD- group (p<0.001). Albuminuria was inversely related to choroidal
and retinal thickness measures (p<0.001) and to the indices of superficial parafoveal
(p<0.05) and foveal (p<0.05) vascular density.
Conclusions: CKD is associated with retinal thinning, eGFR and decreasing renal
function with progressive reduction of choroidal and retinal vascular density. SS-OCT
and OCTA documented close association between CKD and reduction of both
choroidal thickness and paracentral retinal vascular density in hypertensive patients
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
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
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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