209 research outputs found

    Mutual estimates of time-frequency representations and uncertainty principles

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    In this paper we give different estimates between Lebesgue norms of quadratic time-frequency representations. We show that, in some cases, it is not possible to have such bounds in classical LpL^p spaces, but the Lebesgue norm needs to be suitably weighted. This leads to consider weights of polynomial type, and, more generally, of ultradifferentiable type, and this, in turn, gives rise to use as functional setting the ultradifferentiable classes. As applications of such estimates we deduce uncertainty principles both of Donoho-Stark type and of local type for representations

    Investigation of electrode material - redox couple systems for reverse electrodialysis processes. Part II: experiments in a stack with 10-50 cell pairs

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    Abstract The performances of reverse electrodialysis depend on several factors, including the nature of the electrode material and of the redox processes adopted to make possible the conversion between chemical potential and electric power. In this paper the possible utilization of various redox processes (reduction/oxidation of iron species, oxidation and reduction of water, oxidation of chlorine and reduction of water) was studied in a stack equipped with 10-50 cell pairs and by focused electrolyses in a three compartment cell. The effect of selected redox processes on power density output and eventual contamination of saline solutions flowing in the stack was evaluated in detail. The effect of the number of cell pairs and of the concentration of saline solutions was also investigated

    Fracture strength and ribbond fibers : in vitro analysis of mod restorations

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    Ribbond fibers are supposed to be a reinforcing material in restoration of compromised teeth. This study aims to compare MOD restorations with and without Ribbond Fiber in terms of fracture strength under axial loading; to identify the minimum depth of M

    Impact of climate change on the energy performance of building envelopes and implications on energy regulations across Europe

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    This paper delves into the potential impact of a changing climate on the energy performance of European buildings. Research aims to provide a comprehensive evaluation of current energy requirements focusing on the envelope, considering existing regulations in national policies. Energy simulations are conducted at 94 locations across the European Union to cover the climatic variability and Koppen climate classification. The research analyzes future climate scenarios for the years 2030, 2050, and 2070, using three different Representative Concentration Pathways (RCP 2.6, 4.5, 8.5). According to a comprehensive analysis of heating, cooling, and overall energy performance, climate plays a significant role in buildings’ energy balance. In moderately cool climate countries, the demand for air conditioning is projected to decrease in the years ahead. Conversely, in countries with a warm climate, there is a projected increase in the overall energy demand. Consequently, a revision of current energy regulations should be a priority. Providing insights into the relation between building design, energy efficiency, and climate change, the research identifies policy adjustments to ensure buildings can effectively respond to changing climatic conditions. A holistic and dynamic approach can support building design accounting for long-term impacts of climate change to create resilient and energy-efficient structures

    Macular ganglion cell layer thickness after macula-off rhegmatogenous retinal detachment repair: scleral buckling versus pars plana vitrectomy

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    (1) Background: We evaluated macular ganglion cell layer-inner plexiform layer (GCL-IPL) thickness in patients with primary macula-off rhegmatogenous retinal detachment (RRD) treated with scleral buckling (SB) or pars plana vitrectomy (PPV) using spectral domain optical coherence tomography (SD-OCT). (2) Methods: In this retrospective, observational study, we reviewed the medical records of patients undergoing SB or PPV surgery for macula-off RRD. SD-OCT was performed at three and 12 months after surgery. The central and parafoveal GCL-IPL thicknesses in treated eyes were compared with those of healthy fellow eyes. OCT measurements between the SB and PPV group were also compared using the analysis of covariance. (3) Results: Seventy-one eyes of 71 patients with a mean age of 61.2 ± 11.7 years were included. The parafoveal GCL-IPL thickness of the PPV group was significantly reduced, with respect to fellow eyes, at three and 12 months (p < 0.01). After adjusting for age, axial length, spherical equivalent, RD extent, preoperative intraretinal cysts, duration of symptoms and postoperative IOP, the parafoveal GCL-IPL thickness in the PPV group was significantly reduced with respect to the SB group, both at three and 12 months (F = 11.45, p = 0.001 and F = 12.37, p = 0.001, respectively). (4) Conclusions: In conclusion, the GCL-IPL is reduced in thickness in eyes with macula-off RRD treated with vitrectomy and is significantly thinner compared to eyes undergoing scleral buckling surgery

    Influence of Surgical Technique on Post-Operative Complications in the Extraction of the Lower Third Molar: A Retrospective Study

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    The surgical extraction of the impacted third molar is frequently associated with several complications. The purpose of this study is to assess how two different surgical protocols affect post-operative complications during the extraction of the lower impacted third molars. In order to compare and evaluate two different techniques (triangular flap vs. envelope flap), and the relative post-extraction complications, two groups of 150 patients each underwent to surgical impacted third molar extraction and 60 days of follow-up. The complication rate in the two groups was 14.00% in group A and 17.33% in group B. There was a strong association between smoking (OR: 2.8) and the use of oral contraceptives (OR: 1.75) with complications. The age- and sex-related incidence of complications in hard tissue healing has great variability in the literature; the analysis performed on our data did not show a statistically significant association between them. Even though related to a higher incidence of transient changes in sensitivity, it was found that the envelope flap saw a lower percentage of complications. There is still no clarity on which is the best protocol for the extraction of the lower impacted third molar, and the choice often depends on the surgeon’s experience

    Effects of Microencapsulated Ferulic Acid or Its Prodrug Methyl Ferulate on Neuroinflammation Induced by Muramyl Dipeptide

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    Ferulic acid (Fer) is known for its antioxidant and anti-inflammatory activities, which are possibly useful against neurodegenerative diseases. Despite the ability of Fer to permeate the brain, its fast elimination from the body does not allow its therapeutic use to be optimized. The present study proposes the preparation and characterization of tristearin- or stearic acid-based solid lipid microparticles (SLMs) as sustained delivery and targeting systems for Fer. The microparticles were produced by conventional hot emulsion techniques. The synthesis of the methyl ester of Fer (Fer-Me) allowed its encapsulation in the SLMs to increase. Fer-Me was hydrolyzed to Fer in rat whole blood and liver homogenate, evidencing its prodrug behavior. Furthermore, Fer-Me displayed antioxidant and anti-inflammatory properties. The amount of encapsulated Fer-Me was 0.719 +/- 0.005% or 1.507 +/- 0.014% in tristearin or stearic acid SLMs, respectively. The tristearin SLMs were able to control the prodrug release, while the stearic acid SLMs induced a significant increase of its dissolution rate in water. Jointly, the present results suggest that the tristearin SLMs loaded with Fer-Me could be a potential formulation against peripheral neuropathic pain; conversely, the stearic acid SLMs could be useful for Fer-Me uptake in the brain after nasal administration of the formulation

    A workflow to generate physical 3D models of cerebral aneurysms applying open source freeware for CAD modeling and 3D printing

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    Objectives: 3D anatomical models are becoming a new frontier in surgery for planning and simulation on an individualized patient specific basis. Since 1999, 3D cerebral aneurysms models for neurosurgery have been proposed. The possibility of reproducing in a realistic 3D fashion the malformation with the surrounding vascular structures, provides important preoperative information for the treatment strategy. The same models can be used for training and teaching.Unfortunately stereolitography is often burdened by high costs and long times of production. These factors limit the possibility to use 3D models to plan surgeries in an easy daily fashion. Patients and methods: Our study enrolled 5 patients harboring cerebral aneurysms. DICOM data of each aneurysm were elaborated by an open source freeware to obtain CAD molds. Afterwards, the 3D models were produced using a fused deposition or a stereolitography printer. Results: Models were evaluated by Neurosurgeons in terms of quality and usefulness for surgical planning. Costs and times of production were recorded. Conclusions: Models were reliable, economically affordable and quick to produce. Keywords: Stereolitography, Cerebral aneurysms, 3D printing, Surgical planning, Aneurysm model
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