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The Particle Finite Element Method (PFEM) is evaluated in the context of the numerical simulation of bird strike events. To assess the possibilities of the method, theoretical analyses are initially performed based on the impact of a water jet on a rigid surface. Then, the influence of the geometry of a more realistic projectile is analyzed and the capability of the method to take into account separation and fragmentation is highlighted. Finally, the method is tested for impacts against deformable targets, using a partitioned algorithm with dynamic relaxation for the fluid-structure interaction, combining the PFEM for the description of the bird with a non-linear Finite Element approach for the description of the impacted structure, which can undergo large plastic deformations. To assess the quality of the obtained results a series of numerical examples from the literature has been selected and used as a reference throughout the paper. Among the studies presented in this work also a novel numerical benchmark for the evaluation of bird impact simulations is proposed.

The Particle Finite Element Method (PFEM) is evaluated in the context of the numerical simulation of bird strike events. To assess the possibilities of the method, theoretical analyses are initially performed based on the impact of a water jet on a rigid surface. Then, the influence of the geometry of a more realistic projectile is analyzed and the capability of the method to take into account separation and fragmentation is highlighted. Finally, the method is tested for impacts against deformable targets, using a partitioned algorithm with dynamic relaxation for the fluid-structure interaction, combining the PFEM for the description of the bird with a non-linear Finite Element approach for the description of the impacted structure, which can undergo large plastic deformations. To assess the quality of the obtained results a series of numerical examples from the literature has been selected and used as a reference throughout the paper. Among the studies presented in this work also a novel numerical benchmark for the evaluation of bird impact simulations is proposed.

To compare the stability of the tear film after instillation of eye drops containing hyaluronic acid (HA) or crosslinked hyaluronic acid (CLHA)-based in patients with Sjögren syndrome-related dry eye (SSDE).Forty subjects were included in this study and were divided into 2 groups: the first group (control group) consisted of 20 healthy volunteers; the second group (study group) constituted of 20 suffering from SSDE; before and 5, 30, and 60 min after instillation of eye drops the surface regularity index (SRI) and surface asymmetry index (SAI) were registered.Comparing HA and CLHA, in the control group, SAI show statistically significant difference in the time 0 and in time 5, whereas there is no a statistically significant difference after 30 and 60 min from instillation. For SRI there is no statistically significant difference at any time. In SSDE group there is no statistically significant difference in the time 0 and 5, whereas there is a statistically significant difference after 60 min for SAI, and after 30 and 60 min for SRI from instillation. Both SRI and SAI in dry eyes were significantly greater than in control eyes (P 0.05).Our study showed a better efficacy of CLHA compared with HA in maintaining the stability of the tear film in a patient suffering from SSDE.

To describe the importance of a customized combined systemic and local therapy in the management of inflammatory choroidal neovascularization (iCNV).Observational retrospective case series.Four iCNV cases, complicating posterior uveitis or panuveitis affecting young patients, are reported. Combination of both intravitreal (IVT) and systemic drugs represented a successful treatment strategy.iCNV is a sight-threatening disease which affects mostly young people. Customized and both systemic and IVT therapies might represent the best therapeutic option in order to obtain disease control and good prognosis.

In recent years, the development of portable platforms for performing fast and point-of-care analyses has drawn considerable attention for their wide variety of applications in life science. In this framework, tools combining magnetoresistive biosensors with magnetic markers have been widely studied in order to detect concentrations of specific molecules, demonstrating high sensitivity and ease of integration with conventional electronics. In this work, first, we develop a protocol for efficient hybridization of natural DNA; then, we show the detection of hybridization events involving natural DNA, namely genomic DNA extracted from the pathogenic bacterium Listeria monocytogenes, via a compact magnetic tunneling junction (MTJ)-based biosensing apparatus. The platform comprises dedicated portable electronic and microfluidic setups, enabling point-of-care biological assays. A sensitivity below the nM range is demonstrated. This work constitutes a step forward towards the development of portable lab-on-chip platforms, for the multiplexed detection of pathogenic health threats in food and food processing environment.

The official method (i.e., isoelectric focusing, IEF) for the detection of bovine milk in cheeses obtained from ovine, caprine or buffalo milk, according to the Commission Implementing Regulation (EU) No 150/2018, was compared with three techniques: lateral flow immunoassay (LFA), ELISA and real-time PCR (RT-PCR). Samples of milk, cheese and vegetable drinks were analysed as control samples and after artificial contamination with bovine milk at different concentrations. All these assays, except for ELISA, showed a good diagnostic performance able to detect milk adulteration at concentrations lower than 1% of bovine milk in caprine, ovine and buffalo milk. Relative sensitivity, specificity and accuracy of both ELISA and RT-PCR compared with IEF were 100%, whereas for LFA they corresponded to 100%, 62.5% and 72.7%, respectively. A good agreement among ELISA and RT-PCR versus IEF was observed but only a moderate agreement between LFA and IEF.

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As well known, in the analysis of bird impact events the bird is often reduced, even experimentally, to a surrogate projectile modeled as a weakly compressible fluid (typically a mixture of water and air) [15] . From a numerical standpoint, the presence of a free surface and the strong interaction with the aircraft structures represent a limit for traditional computational fluid dynamics methods based on an Eulerian grid. On the other hand, classical Lagrangian methods cannot cope with the extremely large deformations experienced by the projectile during the impact. The Particle Finite Element Method (PFEM) [6] , [11] is a Lagrangian particle method that can account for very large deformations, preserving the robustness and generality of the finite element method, and thus owning a key advantage over other approaches, e.g. Smoothed Particle Hydrodynamics (SPH) [9] , usually cursed with consistency and stability issues [1] , [10] . To assess the possibilities of the method in the context of bird impact, theoretical analyses are initially performed based on the impact of a water jet on a rigid surface. Then, the influence of the geometry of a more realistic projectile is analyzed and the capability of the method to take into account separation and fragmentation is highlighted.

Summary The possibility of using free-slip conditions within the context of the Particle Finite Element Method (PFEM) is investigated. For high Reynolds number engineering applications in which tangential effects at the fluid-solid boundaries are not of primary interest, the use of free-slip conditions can alleviate the need for very fine boundary layer meshes. Two novel ways for the imposition of free-slip conditions in the framework of the PFEM are presented. The proposed approach emphasizes robustness and simplicity, while retaining a sufficient level of generality. These two methods are then tested in the case of dam break and sloshing problems, and their respective advantages and drawbacks are discussed. It is also shown how the use of free-slip conditions can indirectly improve mass conservation properties of the PFEM, even when coarse meshes are employed. This article is protected by copyright. All rights reserved.

To perform a quantitative analysis of choroidal thickness in patients with Fuchs Uveitis Syndrome (FUS) using enhanced depth imaging optical coherence tomography (EDI-OCT). All patients underwent comprehensive ophthalmic examination, including best-corrected visual acuity, slit-lamp biomicroscopy, applanation tonometry, axial length measurements with a swept-source biometer (IOLMaster 700, Carl Zeiss Medic AG, Jena, Germany) and macular 30° linear EDI- B-scan SD-OCT section (Spectralis HRAII+OCT, Heidelberg Engineering, Heidelberg, Germany) in both eyes. Analysis of choroidal thickness was performed at three different locations: subfoveally, 750 μm nasally, and 750 μm temporally to the fovea. Patients having received any surgery or intravitreal injections in the last 12 months and with axial length variance ≥ 1 mm between both eyes were excluded. Sixteen eyes of eight consecutive patients with unilateral FUS were included. Segmented analysis of the choroid, separately considering Haller’s layer and Sattler’s–choriocapillaris layers, showed statistically significant lower values (p

Purpose: To evaluate choroidal structural changes in patients with multiple evanescent white dot syndrome (MEWDS) during the acute and recovery stages.Methods: Enhanced-depth imaging optical cohere...

Visual symptoms are a common clinical manifestation of multiple sclerosis (MS) and are frequently due to acute optic neuritis (ON). However, the entire visual pathway can be involved throughout the disease course. We describe the case of a young MS patient who experienced visual symptoms that were eventually found to be caused by retinal periphlebitis, an inflammatory process of the anterior visual pathway, which is common during MS, but rarely symptomatic. This case reinforces the concept that in all MS patients complaining visual symptoms, a complete work-up should be performed in order to rule out possible ON mimicries.

This photo essay shows the transient therapeutic effect of pars plana vitrectomy (PPV) in a patient affected by primary intraocular lymphoma (PIOL). PPV is crucial for the diagnosis of PIOL, but it may also play a role in the therapeutic approach.

The aim of the study was to report the clinical utility of optical coherence tomography angiography (OCT-A) in characterizing and differentiating inflammatory lesions and choroidal neovascularization (CNV) in multifocal choroiditis (MFC). A patient affected by MFC complaining central visual loss and scotoma in his left eye was fully investigated with dye-based angiographies, structural OCT and OCT-A. A reactivation of macular CNV was initially suspected, while OCT-A revealed the absence of any decorrelation signal both over the retinal pigment epithelium (RPE) and between RPE and Bruchs' membrane. OCT-A is a promising tool in detecting inflammatory CNV and in differentiating CNV from primitive inflammatory damage. Finely characterizing the aspect of a lesion allows us to choose the best therapeutic strategy for managing these potentially blinding diseases.

Purpose: To perform an analysis of optical coherence tomography (OCT) abnormalities in patients with MEWDS, during the acute and recovery stages, using enhanced depth imaging-OCT (EDI-OCT).Methods: A retrospective case series of five patients with MEWDS was included. EDI-OCT imaging was evaluated to detect retinal and choroidal features.Results: In the acute phase, focal impairment of the ellipsoid zone and external limiting membrane, hyperreflective dots in the inner choroid, and full-thickness increase of the choroidal profile were observed in the affected eye; disappearance of these findings and restoration of the choroidal thickness (p = 0.046) was appreciated in the recovery phase. No OCT abnormalities were assessed in the unaffected eye.Conclusions: EDI-OCT revealed transient outer retinal layer changes and inner choroidal hyperreflective dots. A transient increased thickness of the whole choroid was also identified. This might confirm a short-lasting inflammatory involvement of the whole ch...

Resume La maladie periodique (fievre familiale mediterraneenne) est une maladie hereditaire, a transmission autosomique recessive, faisant partie des maladies auto-inflammatoires. Elle est caracterisee par des episodes recidivants, de courte duree (en moyenne 24 a 72 heures) et de resolution spontanee, comportant de la fievre et l’inflammation d’une sereuse. La maladie periodique est la plus frequente des fievres periodiques au sein des maladies auto-inflammatoires qui constituent un groupe heterogene et recemment identifie, de maladies caracterisees par des acces febriles recidivants, sans auto-anticorps, ni lymphocytes T specifiques de l’antigene. Habituellement, les crises sont declenchees par des stimuli anodins et peuvent etre precedees d’une phase prodromique. Le gene responsable de la fievre familiale mediterraneenne, appelee MEFV, est situe sur le chromosome 16 (16p13) et code pour la proteine pyrine-marenostrine. Le mecanisme physiopathologique precis de la maladie periodique necessite d’etre encore determine. Le nouveau complexe macromoleculaire appele inflammasome, qui semble jouer un role tres important dans le controle de l’inflammation, pourrait etre implique dans la pathogenie de la maladie periodique. La complication la plus severe a long terme est l’amylose AA qui atteint surtout les reins et peut entrainer une insuffisance renale chronique. Des facteurs de risque, a la fois genetiques et non genetiques, du developpement de l’amylose secondaire ont ete identifies. Actuellement, le seul traitement efficace de la maladie periodique est la colchicine. De nouvelles molecules ont ete essayees chez des patients refractaires a la colchicine, mais des etudes supplementaires portant sur des effectifs suffisants sont necessaires avant d’aboutir a des conclusions formelles.

Retroperitoneal fibrosis (RPF) is a disease characterized by inflammatory fibrotic processes affecting the retroperitoneal structures. Familial Mediterranean Fever (FMF) is an autosomal recessive disorder, characterized by fever and attacks of sterile serositis. Colchicine is the only suitable drug for prevention of acute episodes. We describe a case of association between RPF and FMF in a 48-year-old male, in whom therapy with colchicine, besides preventing acute episodes, allowed RPF regression. To date the association between FMF and RPF and the use of colchicine therapy alone for RPF has not been described.

Purpose To describe a patient with unilateral hypotonic maculopathy and optic disc edema after spontaneous bulbar perforation of a full-thickness scleral defect. Methods An 11-year-old girl underwent scleral buckling surgery. Preoperative and postoperative evaluation included optical coherence tomography and high-resolution 3T magnetic resonance imaging. Results The scleral defect was covered with Tenon capsule sheaths and a meridional silicone buckle. One year postoperatively, visual acuity and macular and optic disc morphology were completely restored. Conclusions Ocular hypotony related to a defect of the sclera forming the roof of a retinochoroidal coloboma is a rare event. Hypotony was a consequence of a defect at the level of an atypical retinochoroidal coloboma where the scleral wall was found to be absent.

In this paper a Lagrangian finite element approach for the simulation of incompressible flows is presented, based on the so-called Particle Finite Element Method (PFEM). The spatial discretization and the definition of the boundary terms are discussed in detail with a specific focus on free-surface flows. Additionally, some problems that can arise from the use of such a method are pointed out. Some numerical examples are given and discussed in the last section of the paper.

Purpose To determine the efficacy of timolol 0.1% gel in preventing increased intraocular pressure (IOP) after uncomplicated cataract surgery. Methods In this prospective, double-blinded, randomized study were enrolled 70 patients who underwent uncomplicated cataract surgery with phacoemulsification and intraocular lens implantation. After cataract surgery, 25 patients received a single instillation of timolol 0.1% gel (group A); 20 a single instillation of timolol 0.5% eyedrops (group B); and 25 no treatment (group C). The IOP was measured before surgery (T0) and 5 minutes (T1), 2 hours ± 30 minutes (T2), 4 hours ± 30 minutes (T3), and 24 hours ± 180 minutes after surgery (T4). Results The patients in groups A and B had lower mean IOP values than those in group C at T2, T3, and T4; IOP was higher at T2 and T3 than at T1 in the control group. The IOP spikes in group C were higher than those observed in groups A and B: at T2, they were observed in 40% of the patients in group A, 30% in group B, and 76% in group C; and at T3, in respectively 20%, 10%, and 68%; and at T4, in respectively 4%, 0%, and 28%. Conclusions Timolol 0.1% gel is as effective as timolol 0.5% eyedrops in reducing IOP and in limiting the occurrence of IOP spikes for up to 24 hours after phacoemulsification.