313 research outputs found

    Ultra-Short Pulsed Laser Deposition of Oxides, Borides and Carbides of Transition Elements

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    Oxides, borides and carbides of the transition elements are materials of great interest from a technologic point of view. Many of these materials are used in the form of thin films, so several techniques are commonly used to deposit them. Among these techniques, Pulsed Laser Deposition (PLD) performed using ultra-short pulse lasers, mainly fs lasers, presents unique characteristics in respect to PLD performed using conventional short pulse lasers. Indeed, the films deposited using fs PLD are often nanostructured, and this technique often allows the target stoichiometry to be transferred to the films. In this work, we will review the use of ultra-short PLD in the production of films obtained from transition metal oxides, borides and carbides, evidencing the advantages offered by this technique, together with the problems arising with some of the studied systems. We conclude that even if ultra-short PLD is surely one of the most important and useful deposition techniques, it also presents limits that cannot be ignored

    Laser Irradiation of a Bio-Waste Derived Carbon Unlocks Performance Enhancement in Secondary Lithium Batteries

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    Pyrolyzed carbons from bio-waste sources are renewable nanomaterials for sustainable negative electrodes in Li- and Na-ion batteries. Here, carbon derived from a hazelnut shell has been obtained by hydrothermal processing of the bio-waste followed by thermal treatments and laser irradiation in liquid. A non-focused nanosecond pulsed laser source has been used to irradiate pyrolyzed carbon particles suspended in acetonitrile to modify the surface and morphology. Morphological, structural, and compositional changes have been investigated by microscopy, spectroscopy, and diffraction to compare the materials properties after thermal treatments as well as before and after the irradiation. Laser irradiation in acetonitrile induces remarkable alteration in the nanomorphology, increase in the surface area and nitrogen enrichment of the carbon surfaces. These materials alterations are beneficial for the electrochemical performance in lithium half cells as proved by galvanostatic cycling at room temperature

    Enhancing the Antibacterial Properties of Chitosan Coatings: Ag@Chitosan and Chitosan from Insects

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    In this study, the electrophoretic deposition (EPD) technique was used to prepare chitosanbased coatings with enhanced antibacterial activity suitable for bone implant applications. We designed, prepared, and compared the physico-chemical and biological properties of coatings obtained with commercial chitosan, chitosan enriched with silver nanoparticles, and chitosan obtained from insects. With the aim to consider the issue of sustainability, silver nanoparticles were directly prepared in the chitosan solution by laser ablation via a liquid technique, avoiding the use of chemicals and limiting the production of wastes. Moreover, a sustainable source of chitosan, such as Hermetia Illucens exuviae, was considered. The EPD process was optimized by adjusting parameters like voltage and deposition time to achieve ideal coating thickness and adhesion. The prepared films were characterized by spectroscopic and microscopic techniques such as SEM, XRD, and FTIR. Antimicrobial tests against E. coli and S. aureus revealed that silver nanoparticles enhanced the antibacterial properties of the polymer, whereas the biological evaluation using the WST8 test on MG63 human osteoblast-like cells showed that all coatings were non-toxic. Finally, chitosan obtained from insect showed comparable properties with respect to the commercial polymer, suggesting it could replace seafood-derived chitosan in biomedical applications, whereas the Ag@chitosan composite demonstrated superior antibacterial activity without compromising its biocompatibility

    Imaging and Endoscopic Diagnosis of Lung Diseases in Small Animals. A Review

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    Diagnostic imaging plays a fundamental role in the diagnosis of pulmonary diseases. Radiography, ultra-sound, computed tomography, and endoscopy are important tools for achieving a diagnosis. The choice of diagnostic procedure varies according to the patient, the suspected diagnosis and the risk/benefit ratio. Cul-ture, cytology and histology are nearly always necessary to obtain a definitive diagnosis. Several biopsy sam-pling techniques are described. Surgical biopsies are the gold standard for the diagnosis of bronchiolitis or interstitial lung diseases but often not performed due to the high risk. In humans, the introduction of trans -bronchial cryobiopsies has led to excellent results in the study of interstitial lung diseases. (c) 2022 Elsevier Inc. All rights reserved

    Mn-Doped Glass–Ceramic Bioactive (Mn-BG) Thin Film to Selectively Enhance the Bioactivity of Electrospun Fibrous Polymeric Scaffolds

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    In recent years, significant progress has been made in the development of new technologies to meet the demand for engineered interfaces with appropriate properties for osteochondral unit repair and regeneration. In this context, we combined two methodologies that have emerged as powerful approaches for tissue engineering application: electrospinning to fabricate a nanofibrous polymeric scaffold and pulsed laser deposition to tune and control the composition and morphology of the scaffold surface. A multi-component scaffold composed of synthetic and natural polymers was proposed to combine the biocompatibility and suitable mechanical properties of poly(D,L-lactic acid) with the hydrophilicity and cellular affinity of gelatin. As part of a biomimetic strategy for the generation of bi-functional scaffolds, we coated the electrospun fibers with a thin film of a bioactive glass–ceramic material supplemented with manganese ions. The physico-chemical properties and composition of the bi-layered scaffold were investigated, and its bioactivity, in terms of induced mineralization, was tested by incubation in a simulated body fluid buffer. The processes of the inorganic film dissolution and the calcium phosphate phases growth were followed by microscopic and spectroscopic techniques, confirming that a combination of bioactive glass–ceramics and nanofibrous scaffolds has promising potential in the regeneration of osteochondral tissue due to its ability to induce mineralization in connective tissues. © 2022 by the authors

    Removal of diclofenac from aqueous solutions by adsorption on thermo‑plasma expanded graphite

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    The adsorption of diclofenac on thermo-plasma expanded graphite (a commercial product) from water solutions was investigated. The adsorbent material was characterized by SEM, TEM, BET, Raman and X-ray diffraction analyses. Typical diffractogram and Raman spectrum of graphitic material, dimension of 24.02 nm as crystallite dimension and a surface area of 47 m2 g−1 were obtained. The effect of pH on the adsorption capacity was evaluated in the range 1–7 and the adsorption mechanism was described by kinetic and isothermal studies. Pseudo-second order and Dubinin–Radushkevich models agreed with theoretical values of adsorption capacity (i.e. 400 and 433 mg g−1, respectively) and resulted to be the best fit for kinetics and isothermal experimental data. The thermodynamics of the process was evaluated by plotting the adsorption capacity/concentration ratio at the equilibrium as a function of different values of the multiplicative inverse of temperature. Moreover, the adsorbent regeneration was also investigated, comparing two different remediation techniques. Solvent washing performed with NaOH 0.2 M and thermo-treatment carried out by heating in an oven at 105 °C for 2 h and then at 200 °C for 4 h. The thermo-treatment was the best technique to regenerate the adsorbent, ensuring same performance after 4 cycles of use and regeneration

    The Brain on Low Power Architectures - Efficient Simulation of Cortical Slow Waves and Asynchronous States

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    Efficient brain simulation is a scientific grand challenge, a parallel/distributed coding challenge and a source of requirements and suggestions for future computing architectures. Indeed, the human brain includes about 10^15 synapses and 10^11 neurons activated at a mean rate of several Hz. Full brain simulation poses Exascale challenges even if simulated at the highest abstraction level. The WaveScalES experiment in the Human Brain Project (HBP) has the goal of matching experimental measures and simulations of slow waves during deep-sleep and anesthesia and the transition to other brain states. The focus is the development of dedicated large-scale parallel/distributed simulation technologies. The ExaNeSt project designs an ARM-based, low-power HPC architecture scalable to million of cores, developing a dedicated scalable interconnect system, and SWA/AW simulations are included among the driving benchmarks. At the joint between both projects is the INFN proprietary Distributed and Plastic Spiking Neural Networks (DPSNN) simulation engine. DPSNN can be configured to stress either the networking or the computation features available on the execution platforms. The simulation stresses the networking component when the neural net - composed by a relatively low number of neurons, each one projecting thousands of synapses - is distributed over a large number of hardware cores. When growing the number of neurons per core, the computation starts to be the dominating component for short range connections. This paper reports about preliminary performance results obtained on an ARM-based HPC prototype developed in the framework of the ExaNeSt project. Furthermore, a comparison is given of instantaneous power, total energy consumption, execution time and energetic cost per synaptic event of SWA/AW DPSNN simulations when executed on either ARM- or Intel-based server platforms

    Similar long-term results of mitral valve repair for anterior compared with posterior leaflet prolapse

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    ObjectiveThe results of mitral valve repair for anterior leaflet prolapse have been less gratifying than those reported for posterior leaflet prolapse. We compared the long-term durability of 2 different surgical techniques: the edge-to-edge repair, which is used for the treatment of anterior leaflet prolapse, and quadrangular resection, which has been adopted for correction of posterior leaflet prolapse.MethodsFrom 1991 through April 2004, 133 patients with anterior leaflet prolapse and 605 with posterior leaflet prolapse caused by degenerative mitral disease underwent valve repair. The edge-to-edge repair was used for correction of anterior leaflet prolapse, and quadrangular resection of the posterior leaflet, with or without sliding plasty, was used for correction of posterior leaflet prolapse. All patients received a concomitant annuloplasty procedure.ResultsNo hospital deaths occurred in the anterior leaflet prolapse group, whereas 2 (0.3%) patients died in the posterior leaflet prolapse group (P = .7). Follow-up was 100% and 97.2% complete in the anterior and posterior leaflet prolapse groups, respectively. At 10 years, overall survival was 91% ± 4.06% for anterior leaflet prolapse and 93.5% ± 1.81% for posterior leaflet prolapse (P = .18), and freedom from cardiac death was 95.8% ± 2.83% for anterior leaflet prolapse and 97.4% ± 0.95% posterior leaflet prolapse (P = .27). Freedom from reoperation was 96% ± 2.3% in the anterior leaflet prolapse group and 96.5% ± 1.18% in the posterior leaflet prolapse group (P = .37). At follow-up (mean, 4.5 ± 3.12 years; range, 1 month-13.2 years), New York Heart Association functional class I or II was documented in 93.2% of patients in the anterior leaflet prolapse group and 92.8% in the posterior leaflet prolapse group (P = .98).ConclusionsThe long-term results of the edge-to-edge repair in the setting of anterior leaflet prolapse are similar to those obtained with quadrangular resection for the treatment of posterior leaflet prolapse

    Two-Port Laparoscopic Adrenalectomy in Dogs

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    SIMPLE SUMMARY: An adrenal mass represents the primary indication for adrenalectomy. Laparoscopic adrenalectomy is a minimally invasive surgical technique that minimizes pain and improves patient recovery. The traditional technique involves the use of a single or multiple port (three or four). The objective of the study was to evaluate the feasibility and complication rate of two-port laparoscopic adrenalectomy to remove adrenal masses smaller than 4 cm in diameter. In total, 16 dogs with adrenal masses were enrolled in the study and clinicopathologic data were harvested from the medical records. The dogs were placed in sternal recumbency with cushions positioned under the sternum and pubis to simulate the quadrupedal station and displace the abdominal viscera. In all cases, the procedures were feasible with two ports. In five cases, capsule rupture occurred, and all were adrenal gland carcinomas. ABSTRACT: The gold-standard treatment for functional tumors is adrenalectomy, and the procedure can be either open or laparoscopic. Laparoscopic adrenalectomy (LA) is a minimally invasive technique designated for small–medium-sized adrenal tumors without vascular invasion. LA is routinely performed using three or four ports with the patient in sternal or lateral recumbency. The aim of the study was to evaluate the feasibility of LA with two ports in order to reduce invasiveness and improve patient recovery. In total, 16 dogs with adrenal tumors were included in the study and the two-port technique was performed. Adrenalectomy was performed based on the presence of hypercortisolism in thirteen cases, whereas, in three cases, adrenalectomy was performed in the absence of evidence of cortisol production. Thirteen cases were carcinomas and three were adenomas of the adrenal gland; furthermore, twelve were on the left side and four were on the right side. Capsule rupture occurred in five cases. After performing the technique in all cases, no additional ports or laparotomy conversion occurred. Based on the authors’ experience, laparoscopic adrenalectomy can be performed with two ports

    The eagle jugular syndrome

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    The elongation of the styloid process is historically associated with two variants of the Eagle syndrome. The classic one, mainly characterized by pain and dysphagia, and the carotid variant characterized by pain and sometimes by cerebral ischemia. We observed a further variant characterized by a styloid elongation coursing adjacent to the transverse process of C1, causing significant compression of the internal jugular vein
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