243 research outputs found

    Density-friendly Graph Decomposition

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    Decomposing a graph into a hierarchical structure via k-core analysis is a standard operation in any modern graph-mining toolkit. k-core decomposition is a simple and efficient method that allows to analyze a graph beyond its mere de-gree distribution. More specifically, it is used to identify areas in the graph of increasing centrality and connected-ness, and it allows to reveal the structural organization of the graph. Despite the fact that k-core analysis relies on vertex de-grees, k-cores do not satisfy a certain, rather natural, density property. Simply put, the most central k-core is not nec-essarily the densest subgraph. This inconsistency between k-cores and graph density provides the basis of our study. We start by defining what it means for a subgraph to be locally-dense, and we show that our definition entails a nested chain decomposition of the graph, similar to the one given by k-cores, but in this case the components are ar-ranged in order of increasing density. We show that such a locally-dense decomposition for a graph G = (V,E) can be computed in polynomial time. The running time of the exact decomposition algorithm is O(|V |2|E|) but is signifi-cantly faster in practice. In addition, we develop a linear-time algorithm that provides a factor-2 approximation to the optimal locally-dense decomposition. Furthermore, we show that the k-core decomposition is also a factor-2 ap-proximation, however, as demonstrated by our experimental evaluation, in practice k-cores have different structure than locally-dense subgraphs, and as predicted by the theory, k-cores are not always well-aligned with graph density

    Management of Accidental Intravitreal Dexamethasone Injection Into the Lens: A Case Report.

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    An accidental injection of a dexamethasone implant inside the crystalline lens was observed in the right eye of a 63-year-old woman suffering from a macular edema secondary to a central retinal vein occlusion. A 23-gauge pars plana vitrectomy and lensectomy followed by an intraocular lens implantation were performed to carefully remove the lens and save the whole implant in order to preserve its therapeutics effects. A strict follow-up over the following 3 months revealed an improving of macular edema and no postoperative complications. The injection of a dexamethasone implant into the lens could be effectively and successfully managed with a pars plana vitrectomy and lensectomy

    Effect of Intravitreal Brolucizumab in the Treatment of Polypoidal Choroidal Vasculopathy With Foveal Lipid Exudation.

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    A 71-year-old woman with a history of blurred vision in her right eye for nearly two months came to our attention. A complete ophthalmological evaluation, including best-corrected visual acuity measurement, fundus examination, spectral-domain optical coherence tomography, fluorescein angiography, and indocyanine green angiography, was performed. Multimodal imaging showed the presence of a polypoidal choroidal vasculopathy (PCV) lesion surrounded by diffuse hard exudates in the macular area. Our patient received three monthly intravitreal injections of brolucizumab during the loading phase, followed by an intravitreal injection every eight weeks for a total of 48 weeks of follow-up. The therapy appeared to be effective for improving both visual and anatomical outcomes revealing an important regression of the PCV and an almost complete reabsorption of lipid exudates. Intravitreal brolucizumab could be considered an effective treatment in the management of lipid exudation in PCV patients

    Interobserver Agreement of Novel Classification of Central Serous Chorioretinopathy

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    Objective To validate the newly proposed multimodal-imaging-based classification for central serous chorioretinopathy (CSCR). Methods This was a retrospective study performed in a total of 87 eyes of 44 patients with a diagnosis of CSCR. Multimodal images in the form of auto-fluorescence, fundus fluorescein angiography, indocyanine green angiography, and optical coherence tomography (OCT) images, of all the patients, were presented to two masked retina specialists. The masked observers graded each eye into simple or complex; primary, recurrent, resolved; and specific features such as foveal involvement, outer retinal atrophy, and choroidal neovascularization (CNV). Interobserver agreement was assessed using Cohen's kappa. In areas of non-consensus, a detailed discussion was carried out with a third independent grader. Results The mean age of the 44 patients (32 males and 12 females) was 49.2±9.3 years. We found a moderate-strong agreement between the two observers in all subclassifications, that included "simple or complex" (kappa value=0.91, 95% CI 0.82-0.99, p<0.001); "primary/recurrent/resolved" (kappa value=0.88, 95% CI 0.80-0.96, p<0.001) and "foveal involvement" (kappa value=0.89,95%CI 0.8-0.98, p<0.001). However, there was less agreement between the two graders with respect to classification of "outer retinal atrophy" (kappa value=0.72, 95%CI 0.57-0.87, p<0.001) and "presence/absence of CNV" (kappa value=0.75, 95% CI 0.58-0.92, p<0.001). Non-consensus in categorizing "outer retinal atrophy" was seen in eyes with sub-retinal hyper-reflective material (SHRM) and outer nuclear layer (ONL) thinning overlying subretinal fluid, and non-consensus in categorizing "CNV" was seen in eyes with inner choroidal atrophy. Conclusion Our study reports the validity and strong interobserver agreement in several aspects of the multimodal-imaging-based classification. This could support its implementation in clinical practice and pave way for appropriate treatment guidelines

    The binding of glucosylceramidase to glucosylceramide is promoted by its activator protein

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    AbstractA protein activator of glucosylceramidase (EC 3.2.1.45) has been previously identified by us in human placenta [(1985) Biochim. Biophys. Acta 836, 157–166]. In the present paper we report that its function in vitro is to stimulate the binding of the enzyme to its substrate, glucosylceramide. After the purification step which frees the enzyme of most of its activator protein (octyl-Sepharose 4B chromatography), the capacity of glucosylceramidase to bind to the glucosylceramide micelles is dramatically decreased. The addition of the activator protein to the purified enzyme restores this binding

    Treatments for Ocular Diseases in Pregnancy and Breastfeeding: A Narrative Review.

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    Pregnancy is a medical condition in which the physiological changes in the maternal body and the potential impact on the developing fetus require a cautious approach in terms of drug administration. Individual treatment, a thorough assessment of the extent of the disease, and a broad knowledge of the therapeutic options and different routes of administration of ophthalmic drugs are essential to ensure the best possible results while minimizing risks. Although there are currently several routes of administration of drugs for the treatment of eye diseases, even with topical administration, there is a certain amount of systemic absorption that must be taken into account. Despite continuous developments and advances in ophthalmic drugs, no updated data are available on their safety profile in these contexts. The purpose of this review is both to summarize the current information on the safety of ophthalmic treatments during pregnancy and lactation and to provide a practical guide to the ophthalmologist for the treatment of eye diseases while minimizing harm to the developing fetus and addressing maternal health needs

    No Changes in Keratometry Readings and Anterior Chamber Depth after XEN Gel Implantation in Patients with Glaucoma.

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    Background: This study aimed to compare keratometry and anterior chamber depth (ACD) changes after XEN implantation in primary open-angle glaucoma (POAG) cases over a 3-month follow-up period. Methods: Twenty patients with POAG who underwent XEN63 implantation, either standalone or combined with cataract surgery, were included. Preoperative data, including best-corrected visual acuity (BCVA), refraction, gonioscopy, ophthalmoscopy, intraocular pressure (IOP) evaluation, and axial length, were collected. Corneal topography and ACD measurements were assessed preoperatively and at postoperative days 1, 7, 15, 30, 60, and 90. Each patient’s eye that underwent XEN surgery was included in the study group, with the fellow eye serving as a control. Results: In the study group, there was a significant decrease in IOP after XEN stent implantation at all investigated time intervals (p < 0.05). However, changes in mean ACD did not show statistically significant differences at any follow-up examination in both the study and control groups. Additionally, keratometry readings revealed no significant changes in total astigmatism or steep keratometry values in either group. Conclusions: XEN implantation in POAG cases resulted in a significant decrease in IOP over the 3-month follow-up period. However, there were no significant changes observed in mean ACD or keratometry readings, indicating stability in these parameters post-XEN implantation. These findings suggest that XEN implantation may be an effective option for IOP reduction without affecting corneal curvature or ACD in POAG patients

    Is Eriophyes mali Nalepa present in Italy?

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    In the last few years, blistering symptoms were observed on apple plants in commercial orchards. Blisters are commonly found on apple leaves as well as on small fruits. This symptom is compatible with that described for apple blister mites belonging to the genus Eriophyes (Eriophyidae). To assess the identity of the etiological agent, leaf blisters and buds of symptomatic apple and, as a control, pear plants were examined under the dissection microscope and eriophyoid mites were collected. Specimens were examined using both molecular and morphological approaches. The analysis of sequences confirmed that eriophyoid mites collected from symptomatic apple and pear plants are genetically different. Our analyses highlight a complex scenario inside the genus Eriophyes that is worth to be studied in more detai

    En Face Choroidal Vascularity in Both Eyes of Patients with Unilateral Central Serous Chorioretinopathy

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    The aim of this study was to evaluate the choroidal vascularity analyzing en face optical coherence tomography (OCT) images in patients with unilateral central serous chorioretinopathy (CSC). We retrospectively evaluated 40 eyes of 20 CSC patients and 20 eyes of 10 gender- and age-matched healthy individuals. The sample consisted of: (1) CSC affected eyes; (2) unaffected fellow eyes; (3) healthy eyes. Multiple cross-sectional enhanced depth imaging OCT scans were obtained to create a volume scan. En face scans of the whole choroid were obtained at 5μm intervals and were binarized to calculate the choroidal vascularity index (CVI). The latter, defined as the proportion of the luminal area to the total choroidal area, was calculated at the level of choriocapillaris, superficial, medium and deep layers. No significant differences between choriocapillaris, superficial, medium and deep CVI were found in both eyes of CSC patients, whereas a significant different trend of changes was found in healthy eyes. Nevertheless, the en face CVI shows no difference between affected fellow and healthy eyes. In conclusion, CSC-affected eyes and fellow eyes showed a similar vascular architecture, with no statistical difference between all choroidal layers

    Genome-scaled phylogeny of Saccharomyces cerevisiae from spontaneous must fermentations

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    Modern winemakers commonly inoculate selected S. cerevisiae strains in must to obtain controlled fermentations and reproducible products. However, wine has been produced for thousands of years using spontaneous fermentations from wild strains, a practice that is experiencing a revival among small wine producers. Despite the widespread usage of such strains in the past, there is much to know about their ecology, evolution and functional potential. For example, the reciprocal affinities of these strains within the S. cerevisiae phylogeny have yet to be discovered, as well as the degree of their biodiversity and their impact on wine terroir. To fill this knowledge gap, we aim at characterising at strain level the S. cerevisiae present in spontaneously fermented musts sampled across Italy. We set up a protocol based on polyphenols-removing prewashes, followed by whole-genome shotgun sequencing at a depth of 5Gb of DNA per sample. We performed both an assembly-free analysis to reconstruct the strain-level phylogeny of S. cerevisiae strains using the species-specific-marker based StrainPhlAn, and the reconstruction of Metagenome-Assembled Genomes of these strains for downstream functional analyses. To plan conservation acts in a scenario of continuous climate change, we aim at isolating and maintaining strains of interest. We will present preliminary results from the analysis of spontaneous musts sampled at different fermenting stages
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