73 research outputs found
Riaprire (al)la complessità. Note per un reframing socio-antropologico
No full textThis article is dedicated to explore the different meanings of complexity and the ways in which has been used in sociological theory. After having identified two paths to complexity (named systemic and anthropological) the author proposes a third way of thinking the merge between sociology and complexit
Non-Modal Stability Analysis of the Zero-Dimensional Model of the TRIGA Mark II Reactor
No full textNon-modal stability theory is a new approach to stability analysis focused on the shortterm behaviour of the system following a perturbation. Traditional modal techniques focus on the asymptotic response, missing finite-time instabilities and temporary growth of the parameters. Although widely used in the fluid-dynamics analysis, only seldom applications of this technique exist for nuclear reactors. Building upon previous works done by the author, in the following, the non-modal stability theory is used to study the stability of the zero-dimensional model of the TRIGA Mark II reactor, focusing on the short-term response to perturbations (power, inlet temperature). The primary aim of this work is to show how the widely-used modal stability techniques fail to predict transient growth of the perturbation for asymptotically stable systems, which, if repeated, could potentially lead to additional wear and tear of the system
Reproducibility of fluorescein and indocyanine green angiographic assessment for RAP diagnosis : a multicenter study
No full textPurpose. To explore the interobserver agreement in the diagnosis of retinal angiomatous proliferation (RAP) using fluorescein (FA) and indocyanine green angiographies (ICGA) and to detect which morphologic features of the neovascular lesion are associated with RAP diagnosis. Methods. In this cross-sectional study, consecutive patients with newly diagnosed neovascular age-related macular degeneration (AMD) evaluated in 8 retina centers were considered. The FA and ICGA were obtained in all centers according to a standard protocol, both performed either as a static or as a dynamic examination. All images were graded by 2 observers from different institutions. Results. A total of 201 eyes with neovascular AMD of 155 consecutive patients (mean age 76±8 years) were considered. Overall RAP prevalence was 30% using FA and 26% using ICGA. Patients studied with dynamic angiography were twice as likely to be diagnosed with RAP as those using static angiography. Interobserver agreement for the overall detection of RAP was high using FA (kappa: 0.868; 95% confidence interval [CI]: 0.793-0.944) and very high using ICGA (kappa: 0.905; 95% CI 0.836-0.974). The agreement between the 2 observers tended to be higher for the truncated vessel than for the anastomosis in FA as well as in ICGA, but no comparison yielded statistical significance (p=0.258 and p=0.584, respectively). Conclusions. The interobserver agreement for RAP detection was very good both using FA and ICGA, but the overall detection of RAP was higher for dynamic strategy compared with static one
FACTORS ASSOCIATED WITH VISUAL OUTCOMES AND TREATMENT BURDEN OF MYOPIC NEOVASCULARIZATION OVER 10 YEARS
No full textTreatment of Extra-Foveal Choroidal Neovascularization in Pathological Myopia With Photodynamic Therapy – Two Year Results
No full textVerteporfin photodynamic therapy combined with intravitreal triamcinolone for choroidal neovascularization due to angioid streaks
No full textTo report the visual outcome of photodynamic therapy (PDT) combined with intravitreal triamcinolone acetonide (IVTA) for choroidal neovascularization (CNV) secondary to angioid streaks (AS)
Spectral-domain OCT in anti-VEGF treatment of myopic choroidal neovascularization
No full textPurpose To evaluate changes in macular morphology due to myopic choroidal neovascularization (CNV), using spectral-domain optical coherence tomography (SD-OCT). Methods In all, 22 eyes with recent-onset untreated CNV underwent 1 intravitreal injection of anti-vascular endothelial growth factor (anti-VEGF), followed by a pro-re-nata regimen. SD-OCT was performed at baseline (before first administration of anti-VEGF treatment) and month 1, and 2; macular morphologic changes and outer retina characteristics (SD-OCT findings) associated with CNV activity were evaluated. Sensitivity and specificity were calculated for SD-OCT findings using fluorescein angiography (FA) as standard reference. Results Mean central retinal thickness (CRT) showed no significant reduction from baseline (284 +/- 98 mu m) to month 1 (257 +/- 74 mu m) and month 2 (263 +/- 72 mu m). A hyper-reflective lesion with fuzzy borders (fuzzy area), and 'absent or altered' IS/OS junction were the only SD-OCT findings associated with CNV activity (P<0.0001). Both these SD-OCT findings showed good sensitivity and specificity (95.1 and 96.0% (95% CI: 0.87-0.89), respectively, for the fuzzy area; 87.9 and 66.7% (95% CI: 0.65-0.87), respectively, for 'absent or altered' IS/OS junction) when compared with FA leakage (standard reference). Conclusions Outer retina characteristics (ie, hyper-reflective lesion with fuzzy borders, and 'absent or altered' IS/OS junction) appear more meaningful than CRT in the evaluation of myopic CNV activity. These SD-OCT findings show overall good sensitivity and specificity when compared with FA leakage (standard reference), and could be considered as an alternative diagnostic tool to FA for myopic CNV monitoring. Eye (2012) 26, 976-982; doi:10.1038/eye.2012.75; published online 27 April 2012Purpose To evaluate changes in macular morphology due to myopic choroidal neovascularization (CNV), using spectral-domain optical coherence tomography (SD-OCT). Methods In all, 22 eyes with recent-onset untreated CNV underwent 1 intravitreal injection of anti-vascular endothelial growth factor (anti-VEGF), followed by a pro-re-nata regimen. SD-OCT was performed at baseline (before first administration of anti-VEGF treatment) and month 1, and 2; macular morphologic changes and outer retina characteristics (SD-OCT findings) associated with CNV activity were evaluated. Sensitivity and specificity were calculated for SD-OCT findings using fluorescein angiography (FA) as standard reference. Results Mean central retinal thickness (CRT) showed no significant reduction from baseline (284 +/- 98 mu m) to month 1 (257 +/- 74 mu m) and month 2 (263 +/- 72 mu m). A hyper-reflective lesion with fuzzy borders (fuzzy area), and 'absent or altered' IS/OS junction were the only SD-OCT findings associated with CNV activity (P<0.0001). Both these SD-OCT findings showed good sensitivity and specificity (95.1 and 96.0% (95% CI: 0.87-0.89), respectively, for the fuzzy area; 87.9 and 66.7% (95% CI: 0.65-0.87), respectively, for 'absent or altered' IS/OS junction) when compared with FA leakage (standard reference). Conclusions Outer retina characteristics (ie, hyper-reflective lesion with fuzzy borders, and 'absent or altered' IS/OS junction) appear more meaningful than CRT in the evaluation of myopic CNV activity. These SD-OCT findings show overall good sensitivity and specificity when compared with FA leakage (standard reference), and could be considered as an alternative diagnostic tool to FA for myopic CNV monitoring. Eye (2012) 26, 976-982; doi:10.1038/eye.2012.75; published online 27 April 201
En face optical coherence tomography visualization of post-traumatic photoreceptor disruption
No full textNatural Course of Symptomatic Focal Choroidal Excavation
No full textA 32-year-old man was referred to the authors' department for nonspecified macular dystrophy with persistent metamorphopsia in the right eye diagnosed 10 years before and followed using optical coherence tomography. The patient underwent a comprehensive ocular examination, including multimodal imaging evaluation and electrofunctional testing. The diagnosis was consistent with nonconforming focal choroid excavation. Over 10 years, no complications occurred, visual acuity was stable, and optical coherence tomography showed no progression of the lesion during follow-up. In this case, nonconforming symptomatic focal choroid excavation was a nonprogressive condition with good long-term visual outcome
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