1,720,976 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
La percezione del tempo in pazienti con trauma cranioencefalico: uno studio sulla riproduzione temporale.
No full textChronic Central Serous Chorioretinopathy with Pigment Epithelium Detachment Treated with Sildenafil: A Case Report
Full text linkCentral serous chorioretinopathy (CSCR) is a retinal disease that may be complicated by the development of serous retinal pigment epithelial detachment (PED). The exact molecular mechanisms of CSCR have remained uncertain as well as there is no effective medical therapy. Herein, we describe a case of a 43-year-old male suffering from chronic CSCR with PED and visual acuity reduction (20/40) that showed improvement in visual acuity (20/25) and metamorphopsia 2 weeks after daily intake of 20 mg sildenafil tablets. Optical coherence tomography (OCT) scan showed resolution of PED with residual degeneration of the photoreceptor inner and outer segment layer and retinal pigmented epithelium. The patient continued treatment with sildenafil 20 mg for 2 months. Six months after the discontinuation of therapy, visual acuity was maintained, with absence of PED at OCT. Our case supports the hypothesis that phosphodiesterase type 5 (PDE-5) inhibitors may be an alternative in the treatment of patients with CSCR, alone or combined with other medications
Effects of Photo-Biomodulation in Stargardt Disease
Full text linkPurpose: Stargardt disease (STGD1) is the most common hereditary macular degeneration and currently no treatments have been approved to interrupt the progression of the disease. The aim of this study was to evaluate the efficacy of photo-biomodulation in patients with Stargardt disease 1 year after treatment, considering as primary outcomes improvements in best corrected visual acuity (BCVA), microperimetry, and pattern electroretinography (PERG) amplitude. Materials and Methods: Ninety eyes of 45 patients with a diagnosis of Stargardt disease stage 1 were prospectively recruited at the University of Bologna. Selected patients were treated with photo-biomodulation therapy for 1 year for 10 minutes a day, twice a day, and 5 days per week for 12 months. A light emitting diode (LED) of 10 Hz and wavelength 650 nm was used. BCVA and microperimetry were assessed before treatment and 1 year after photo-biomodulation, whereas PERG was assessed at baseline, 1, 3, 6, and 12 months after treatment. Results: BCVA improved from 0.7 [interquartile range (IQR)=0.6–0.9)] to 0.4 (IQR=0.2– 0.5)] after treatment (95% CI=−0.3, −0.35; p=<0.001) and PERG negative wave at 35 ms (N35)-positive wave at 50 ms (P50) amplitude improved from 0.9 (IQR=0.74–1.21) to 2.12 (95% CI=1.11, 1.28; p<0.001). MP-1 Microperimetry improved from 26.5% (IQR=16.75– 40) of median preferred retinal loci (PRL) within an area of 2° of diameter to 38% (IQR=29– 50.25; 95% CI=10.50, 14.50; p=<0.001); on the other hand, PRL within 4° of diameter raised from 72% (IQR=51.5–80) to 80% (IQR=76–87) after photo-biomodulation (95% CI=4.50, 7.50; p<0.001). Also, patients with an improvement of more than 1.205 PERG N35-P50 ratio amplitude at 3 months and more than 1.29 at 6 months tended to present an improvement of more than 0.2 logMar in BCVA at 12 months (p=0.28, AUC=0.630; p=0.30, AUC=0.636). Conclusion: BCVA, PERG, and MP-1 significantly improved 1 year after treatment. Also, improvement of PERG N35-P50 amplitude at 3 and 6 months was correlated to BCVA improvement at 1 year, suggesting that PERG could be useful in predicting visual outcome after photo-biomodulation
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
Retrolental cohesive ophthalmic viscoelastic injection in severely subluxated cataracts: The "Viscolift technique"
No full textIntroduction: To describe a novel surgical approach in the management of subluxated cataracts. Methods: A 70-year-old Caucasian male with a subluxated cataract in the left eye was referred to our clinic at the Azienda Ospedaliero-Universitaria di Bologna- Ophthalmology Unit. The ophthalmic examination revealed a best-corrected visual acuity (BCVA) of 20/200 in the left eye with monocular diplopia and a severely subluxated NO6/NC6 cataract and the fundus examination did not reveal any vitreoretinal abnormalities. The right eye had 20/20 BCVA and was pseudophakic. After a 300° conjunctival peritomy, a single 25-gauge valved trocar 4 mm was inserted from the limbus in the inferotemporal quadrant, where the cataract was mainly dislocated and a corneal paracentesis to reduce the anterior chamber intraocular pressure was performed. Subsequently cohesive viscoelastic was progressively injected in the retrolental space through the trocar, to recenter and elevate the subluxated cataract. Thereafter, a complete centered capsulorhexis was performed, four capsular hooks were inserted to stabilize the bag, and complete phacoemulsification was performed with intact posterior capsular support. In the end, given the lack of capsular support elements such as the Cionni ring or Ahmed segment, a sutureless scleral fixated intraocular lens was implanted. Results: One week after surgery, the BCVA was 20/25, and the final BCVA at 6 months was 20/20, without any complications. Conclusions: Retrolental cohesive ophthalmic viscoelastic injection could represent a novel effective surgical approach in recentering and elevating subluxated cataracts, facilitating the capsulorhexis, and reducing the risk of a pars plana approach
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