1,720,991 research outputs found
Ectropion and Conjunctival Mass in a Patient with Primary Bilateral Conjunctival Amyloidosis
Full text linkBackground. Amyloidosis is a group of disorders characterized by deposition of an extracellular protein, known as amyloid, in an abnormal fibrillar form with highly characteristic histopathologic staining properties. The clinical presentation can vary from a focal, localized lesion where amyloidosis has minor clinical consequences to extensive systemic disease that can involve any organ system of the body. Ocular amyloidosis can occur as a localized lesion or as a part of a systemic disorder. Conjunctival amyloidosis is an uncommon condition that is rarely associated with systemic disease. It may be a manifestation of an immunologic disorder. Case Report. We report the case of a patient with bilateral conjunctival amyloidosis who was referred to us with the suspicion of a malignant conjunctival lesion. Examination of both eyes showed a yellow-pinkmass with prominent intrinsic vessels, subconjunctival hemorrhage, and ectropion of the left lower eyelid. Diagnosis of primary localized conjunctival amyloidosis was made based on histopathologic evaluation of incisional biopsy and negative systemic work-up. Conclusion. Ocular amyloidosis is a rare disease that is slowly progressive and has a wide variety of clinical presentations. Consequently, the clinical diagnosis is often overlooked or delayed. Definitive diagnosis is achieved through histopathologic evaluation of biopsy specimen
Customized Corneal Cross-Linking
No full textPersonalized accelerated crosslinking nomograms for the management of corneal ectasia were conceived after comparative analysis of demarcation lines and cell viability observed after customized accelerated epithelium-off crosslinking CXL treatments by spectral domain corneal OCT and scanning laser in vivo confocal microscopy matching all the clinical and instrumental data with mathematical models. Accelerated high-fluence Topography-guided CXL at 30 mW/cm2 UV-Power and Accelerated epithelium-off CXL with 9 and 15 mW/cm2 UV-A power with standardized Fluence of 5.4 J/cm2 were safe and effective demostrating a keratocytes apoptosis and demarcation line depth between 280 and 340 μm. The 30 mW ACXL showed a penetration with continuous and pulsed light between 150 and 200 μm. No endothelial damage was reported in any case. In vivo morphological studies demonstrated that Accelerated CXL allow a pachymetry-guided cutomization of CXL maintainig the standard Fluence of 5.4 J/cm2 and a total treatment time under 20 min. Moreover a pachymetry-guided ACXL nomogram (M nomogram) developed by Mazzotta C and Friedman M matching the physical and mathematical calculations with the miscostructural IVCM and OCT observations of demarcation lines depths allow an efficacous CXL management of primary and iatrogenic ectatic corneas also allowing a safe management of thin ectatic corneas
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
Pulsed vs continuous light accelerated corneal collagen crosslinking: in vivo qualitative investigation by confocal microscopy and corneal OCT
No full textPURPOSE: To assess qualitative corneal changes and penetration of pulsed and continuous light accelerated crosslinking by in vivo confocal microscopy and corneal OCT.
METHODS: A total of 20 patients affected from progressive keratoconus were enrolled in the study. Ten eyes of 10 patients underwent an epithelium-off pulsed-light accelerated corneal collagen crosslinking (PL-ACXL) by the KXL UV-A source (Avedro Inc.) with 8 min (1 s on/1 s off) of UV-A exposure at 30 mW/cm(2) and energy dose of 7.2 J/cm(2); 10 eyes of 10 patients underwent an epithelium-off continuous-light accelerated corneal collagen crosslinking (CL-ACXL) at 30 mW/cm(2) for 4 min. Riboflavin 0.1% dextran-free plus hydroxyl-propyl-methylcellulose solution (VibeX Rapid, Avedro Inc.) was used for a 10-min corneal soaking. Treated eyes were examined by in vivo scanning laser confocal analysis and spectral anterior segment OCT at 1, 3, and 6 months.
RESULTS: Epithelial stratification and nerves regeneration improved in time, being complete at month 6 in both groups without endothelial damage. Keratocyte apoptosis in PL-ACXL was estimated at a mean depth of ∼200 μm, whereas an uneven demarcation line was detectable by confocal microscopy at a mean depth of 160 μm in CL-ACXL.
CONCLUSION: In vivo confocal microscopy and corneal OCT allowed a precise qualitative analysis of the cornea after epithelium-off PL-ACXL and CL-ACXL treatments. Apoptotic effect was higher in pulsed than in continuous light treatments, exceeding 200 μm in corneal stroma. According to different morphological data, the clinical efficacy of ACXL needs to be determined in a long-term follow-up and large cohort of patient
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
Pulsed light accelerated crosslinking versus continuous light accelerated crosslinking: one-year results
Full text linkPurpose. To compare functional results in two cohorts of patients undergoing epithelium-off pulsed (pl-ACXL) and continuous light accelerated corneal collagen crosslinking (cl-ACXL) with dextran-free riboflavin solution and high-fluence ultraviolet A irradiation. Design. It is a prospective, comparative, and interventional clinical study. Methods. 20 patients affected by progressive keratoconus were enrolled in the study. 10 eyes of 10 patients underwent an epithelium-off pl-ACXL by the KXL UV-A source (Avedro Inc., Waltham, MS, USA) with 8 minutes (1 sec. on/1 sec. off) of UV-A exposure at 30 mW/cm(2) and energy dose of 7.2 J/cm(2); 10 eyes of 10 patients underwent an epithelium-off cl-ACXL at 30 mW/cm(2) for 4 minutes. Riboflavin 0.1% dextran-free solution was used for a 10-minutes corneal soaking. Patients underwent clinical examination of uncorrected distance visual acuity and corrected distance visual acuity (UDVA and CDVA), corneal topography and aberrometry (CSO EyeTop, Florence, Italy), corneal OCT optical pachymetry (Cirrus OCT, Zeiss Meditec, Jena, Germany), endothelial cells count (I-Conan Non Co Robot), and in vivo scanning laser confocal microscopy (Heidelberg, Germany) at 1, 3, 6, and 12 months of follow-up. Results. Functional results one year after cl-ACXL and pl-ACXL demonstrated keratoconus stability in both groups. Functional outcomes were found to be better in epithelium-off pulsed light accelerated treatment together with showing a deeper stromal penetration. No endothelial damage was recorded during the follow-up in both groups. Conclusions. The study confirmed that oxygen represents the main driver of collagen crosslinking reaction. Pulsed light treatment optimized intraoperative oxygen availability improving postoperative functional outcomes compared with continuous light treatment
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
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