296 research outputs found

    Retinal Vascular Features in Ocular Blunt Trauma by Optical Coherence Tomography Angiography

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    In this prospective study, we analysed the changes in retinal vessel density (VD) using optical coherence tomography angiography (OCTA) in patients with commotio retinae up to 6 months after blunt ocular trauma. We analysed the VD in the superficial capillary plexus (SCP), deep capillary plexus (DCP), radial peripapillary capillary (RPC) and the foveal avascular zone (FAZ) area at 48 h, and 1, 3 and 6 months after the trauma and compared results with those of healthy fellow eyes. We also evaluated the best-corrected visual acuity (BCVA) and the structural, spectral domain (SD)-OCT parameters: ganglion cell complex (GCC) and retinal nerve fibre layer (RNFL). A total of 18 eyes of 18 patients (8 males, 10 females, mean age 49.61 ± 9.2 years) and 18 healthy control eyes were evaluated. GCC and RNFL thicknesses showed a significant trend towards progressively lower values from 1 month and 3 months after the trauma, respectively, compared to healthy eyes (p < 0.005). The reduction in SD-OCT parameters reached a plateau at 6 months. Similar behaviour was found in the VD of the SCP and RPC that significantly decreased, starting from 1 and 3 months after the trauma, respectively (p < 0.001). At 6 months, the VD values were stable. The DCP presented an initial decrease of VD (p < 0.001), and after 1 month, the values statistically increased until the sixth month, reaching values similar to those of the control group. The FAZ area and BCVA did not show statistically significant changes during the follow-up. OCTA provided a detailed and quantitative analysis of early retinal vascular perfusion alterations after commotio retinae, demonstrating that the impairment of the retinal microvasculature and its progressive changes over time occurred even in the absence of compromised visual acuity

    Structural and vascular features in cavitary congenital optic disc anomaly associated with metaphyseal acroscyphodysplasia

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    Purpose: To evaluate the radial peripapillary vascular plexus of a cavitary congenital optic disc anomaly in a young patient with recessive autosomal metaphyseal acroscyphodysplasia using optical coherence tomography angiography (OCTA). Methods: Observational case report. Results: A 17-year-old man, with diagnosis of metaphyseal acroscyphodysplasia was referred to Eye Clinic for fundus examination and multimodal imaging for retinal epithelium hypertrophy in the right eye. Clinical examination showed cup-shaped metaphyses, short stature, hyperthelorism, and telecanthus. An optic disc coloboma was detected in the right eye on fundus examination. Wide field en-face Optical Coherence Tomography (OCT) showed a hyporeflective area corresponding to the right optic disc coloboma. At OCTA examination, the whole papillary region revealed a rarefaction of the vascular network, while the ganglion cell complex's and retinal fiber layers' parameters were normal in both eyes. Conclusion: The presence of coloboma disc congenital defect linked to embryological abnormalities during the development process could pave the way for a wider understanding of the pathogenesis of metaphyseal acroscyphodysplasia by increasingly framing it as a systemic disease

    An innovative approach for the synthesis of dual modality peptide imaging probes based on the native chemical ligation approach

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    The synthesis of a dual peptide-based imaging probe consists of two steps performed in aqueous solution under mild conditions

    optical coherence tomography angiography in optic nerve sheath meningioma

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    This study describes Spectral Domain-Optical Coherence Tomography (SD-OCT) and Optical Coherence Tomography Angiography (OCTA) features of Optic Nerve Sheath Meningioma (ONSM).A 22-year-old woman, diagnosed with meningioma encircling the right optic nerve inside the intraorbital segment optic canal at the magnetic resonance imaging, showed a normal fundus examination.Instead, SD-OCT and OCTA revealed alterations in the neurostructure and microvascular network of the optic nerve.Despite fundoscopy and fluorescein angiography, SD-OCT and OCTA represent valid, non-invasive and reliable methods to evaluate neurostructural and vascular irregularities in this benign tumor of the optic nerve. Keywords: Optic nerve sheath meningioma, OCT angiography, SD-OC

    A Specific Interaction between Ionic Liquids' Cations and Reichardt's Dye

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    Solvatochromic probes are often used to understand solvation environments at the molecular scale. In the case of ionic liquids constituted by an anion and a cation, which are designed and paired in order to obtain a low melting point and other desirable physicochemical properties, these two indivisible components can interact in a very different way with the probe. This is the case with one of the most common probes: Reichardt's Dye. In the cases where the positive charge of the cation is delocalized on an aromatic ring such as imidazolium, the antibonding orbitals of the positively charged aromatic system are very similar in nature and energy to the LUMO of Reichardt's Dye. This leads to an interesting, specific cation-probe interaction that can be used to elucidate the nature of the ionic liquids' cations. Parallel computational and experimental investigations have been conducted to elucidate the nature of this interaction with respect to the molecular structure of the cation

    Micro-CT imaging and finite element models reveal how sintering temperature affects the microstructure and strength of bioactive glass-derived scaffolds

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    : This study focuses on the finite element simulation and micromechanical characterization of bioactive glass-ceramic scaffolds using Computed micro Tomography ([Formula: see text]CT) imaging. The main purpose of this work is to quantify the effect of sintering temperature on the morphometry and mechanical performance of the scaffolds. In particular, the scaffolds were produced using a novel bioactive glass material (47.5B) through foam replication, applying six different sintering temperatures. Through [Formula: see text]CT imaging, detailed three-dimensional images of the scaffold's internal structure are obtained, enabling the extraction of important geometric features and how these features change with sintering temperature. A finite element model is then developed based on the [Formula: see text]CT images to simulate the fracture process under uniaxial compression loading. The model incorporates scaffold heterogeneity and material properties-also depending on sintering temperature-to capture the mechanical response, including crack initiation, propagation, and failure. Scaffolds sintered at temperatures equal to or higher than 700&nbsp;[Formula: see text]C exhibit two-scale porosity, with micro and macro pores. Finite element analyses revealed that the dual porosity significantly affects fracture mechanisms, as micro-pores attract cracks and weaken strength. Interestingly, scaffolds sintered at high temperatures, the overall strength of which is higher due to greater intrinsic strength, showed lower normalized strength compared to low-temperature scaffolds. By using a combined strategy of finite element simulation and [Formula: see text]CT-based characterization, bioactive glass-ceramic scaffolds can be optimized for bone tissue engineering applications by learning more about their micromechanical characteristics and fracture response

    Epithelioid Hemangioma of the Nose: A Challenging Diagnosis

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    Epithelioid hemangioma is a rare reactive vasoproliferative disease presenting with painless vascular nodules in the dermal and subcutaneous tissues of the head and neck. Clinical diagnosis can be difficult as, in most cases, the only symptom is a progressively tender swelling next to a vessel course. Thus far, few cases of epithelioid hemangioma localized to the nose have been described in the literature. Herein, we present a case of a 47-year-old woman with just such a lesion of the nose, focusing on its diagnosis and treatment

    Anisotropic Mechanical Response of Bovine Pericardium Membrane Through Bulge Test and In-Situ Confocal-Laser Scanning

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    In this work, we present a new experimental setup for the assessment of the anisotropic properties of Bovine Pericardium (BP) membranes. The chemically fixed BP samples have been subjected to a bulge test with in situ confocal laser scanning at increasing applied pressure. The high resolution topography provided by the confocal laser scanning has allowed to obtain a quantitative measure of the bulge displacement; after polynomial fitting, principal curvatures have been obtained and a degree of anisotropy (DA) has been defined as the normalized difference between the maximum and minimum principal curvatures. The experiments performed on the BP membranes have allowed us to obtain pressure-displacement data which clearly exhibit distinct principal curvatures indicating an anisotropic response. A comparison with curvatures data obtained on isotropic Nitrile Buthadiene Rubber (NBR) samples has confirmed the effectiveness of the experimental setup for this specific purpose. Numerical simulations of the bulge tests have been performed with the purpose of identifying a range of constitutive parameters which well describes the obtained range of DA on the BP membranes. The DA values have been partially validated with biaxial tests available in literature and with suitably performed uni-axial tensile tests
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