1,720,981 research outputs found
Near-infrared fundus autofluorescence imaging in a case of photic maculopathy
No full textHerein we describe the characteristics of scanning laser ophthalmoscope imaging (SLO), and particularly of near-infrared fundus autofluorescence modality (IRAF), in photic maculopathy. IRAF visualizes selectively the melanin granules contained in the cells of the Retinal Pigment Epithelium (RPE), which are normally localized in the apical portion of RPE cells, a favorite target of the photic damage to the retina. In the present work we report a three-month follow-up of a case of photic maculopathy, showing that the retinal alterations found by IRAF precisely matched the retinal anomalies found by macular optical coherence tomography, and had a parallel evolution. We think that IRAF could represent a useful imaging modality, together with more conventional imaging, in the management of photic maculopathy
Intervention review. Corticosteroids for the long-term treatment in multiple sclerosis
No full textBackground: Short term high dose corticosteroid treatment improves symptoms and short term disability after an acute exacerbation of multiple sclerosis (MS) but it is unknown whether its long-term use can reduce the accumulation of disability.Objectives: To determine the efficacy and safety of long-term corticosteroid use in MS.Search strategy: We searched the following bibliographic databases: CENTRAL (Issue 1, 2007), MEDLINE (1966 to February 2007) and EMBASE (1980 to February 2007). In an effort to identify further published, unpublished and ongoing trials we searched reference lists and contacted trial authors and one pharmaceutical company.Selection criteria: We considered controlled, randomised trials (RCTs), with or without blinding, of long term treatment (i.e. longer than 6 months) of any type of corticosteroid in MS, irrespective of disease course.Data collection and analysis: Reviewers independently assessed trial quality and extracted data. Study authors were contacted for additional information.Main results: Three trials, all classified at high risk of bias, contributed to this review (Miller 1961; BPSM 1995; Zivadinov 2001) resulting in a total of 183 participants (91 treated). Corticosteroid therapy did not reduce the risk of being worse at the end of follow-up (odds ratio [OR] 0.51, 95% confidence interval [CI] 0.26 to 1.02) but there was a substantial heterogeneity between studies (I(2): 78.4%). I. v. periodic high dose methylprednisolone (MP) was associated with a significant reduction in the risk of disability progression at 5 years in relapsing-remitting (RR) MS (OR 0.26, 95% CI 0.10 to 0.66), while oral continuous low dose prednisolone was not associated with any risk reduction in disability progression at 18 months (OR 1.23, 95% CI 0.43 to 3.56). Risk of experiencing at least one exacerbation at end of follow-up was not significantly reduced with corticosteroid treatment (OR 0.36; 95% CI 0.10 to 1.25).Only one study recorded adverse events: in one patient i. v. MP was discontinued after the fourth pulse when he developed acute glomerulonephritis; a second patient was removed from the study after the fifth i. v. MP pulse because of severe osteoporosis.Authors' conclusions: There is no enough evidence that long-term corticosteroid treatment delays progression of long term disability in patients with MS. Since one study at high risk of bias showed that the administration of pulsed high dose i. v. MP is associated with a significant reduction in the risk of long term disability progression in patients with RR MS, an adequately powered, high quality RCT is needed to investigate this finding.Plain language summaryThe long-term use of anti-inflammatory corticosteroids for treating multiple sclerosisMultiple sclerosis is an inflammatory disease affecting the brain and spinal cord. It results in episodes of neurological deficit which recover (relapses) as well as accumulation of sustained disability with the passage of time. Corticosteroids are potent anti-inflammatory drugs. It is postulated that long-term use of steroids may reduce the accumulation of disability. The reviewers found three studies addressing this issue. A meta-analysis showed a trend towards a beneficial effect of long-term corticosteroids on accumulation of disability; however only two small studies contributed to this result. It was not possible to reliably comment on the effect of long-term corticosteroids on the frequency of relapses. Side effects were poorly documented. Therefore rigorous randomised controlled trials of this treatment are warranted
Dynamic imaging of accommodation by swept-source anterior segment optical coherence tomography
No full textPURPOSE: To study the accommodation process in normal eyes using a commercially available clinical system based on swept-source anterior segment optical coherence tomography (AS-OCT).
SETTING: Ophthalmology Department, University of Parma, Italy.
DESIGN: Evaluation of diagnostic technology.
METHODS: Right eyes were analyzed using swept-source AS-OCT (Casia SS-1000). The optical vergence of the internal coaxial fixation target was adjusted during imaging to obtain monocular accommodation stimuli with different amplitudes (0, 3.0, 6.0, and 9.0 diopters [D]). Overlapping of real and conjugate OCT images enabled imaging of all the anterior segment optical surfaces in a single frame. Central corneal thickness (CCT), anterior chamber depth (ACD), and lens thickness were extracted from the OCT scans acquired at different static accommodation stimulus amplitudes. The crystalline lens was analyzed dynamically during accommodation and disaccommodation by acquiring sequential OCT images of the anterior segment at a rate of 8 frames per second. The lens thickness was extracted from the temporal sequence of OCT images and plotted as a function of time.
RESULTS: The study analyzed 14 eyes of 14 subjects aged 18 to 46 years. During accommodation, the decrease in the ACD was statistically significant (P < .05), as were the increase in the lens thick- ness (P < .001) and the slight movement forward of the lens central point (P < .01). The CCT and anterior chamber width measurements did not change statistically significantly during accommo- dation. The lens thickness at 0 D was positively correlated with age (P < .01).
CONCLUSION: High-resolution real-time imaging and biometry of the accommodating anterior segment can be effectively performed using a commercially available swept-source AS-OCT clinical device
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
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