Pulsed laser deposition of organic and biological materials

We report on the deposition of soft matter thin films by Matrix Assisted Pulsed Laser Evaporation (MAPLE). In particular, thin layers of biological material (Bovine Serum Albumin) and polymers (polyfluorene) for medical and optoelectronic applications, were realized by laser irradiating a frozen solution containing a low amount of material diluted in a laser absorbing volatile solvent. The depositions were carried out varying different parameters as solvent–solute concentration, solvent nature, laser fluencies, etc. The optical, morphological, structural and spectroscopical properties were detected by means of different analyses as FTIR, photoluminescence, AFM and SDS

Possible alternatives to critical elements in coatings for extreme applications

Surface functionalisation and protection have been used since a long time for improving specific properties of materials such as lubrication, water repellence, brightness, and for increasing durability of objects and tools. Among the different kinds of surface treatments used to achieve the required properties, the use of coatings is fundamental to guarantee substrate durability in harsh environments. Extreme working conditions of temperature, pressure, irradiation, wear and corrosion occur in several applications, thus very often requiring bulk material protection by means of coatings. In this study, three main classes of coatings used in extreme conditions are considered: i) hard and superhard coatings for application in machining tools, ii) coatings for high temperatures (thermal barrier coatings), and iii) coatings against corrosion. The presence of critical elements in such coatings (Cr, Y, W, Co, etc.) is analysed and the possibility to use CRMs-free substitutes is reviewed. The role of multilayers and nanocomposites in tailoring coating performances is also discussed for thermal barrier and superhard coatings

Antibacterial Surfaces, Thin Films, and Nanostructured Coatings

Antibacterial surfaces can play a key role in a great number of everyday applications, spanning from biomedical purposes (medical devices, protection equipment, surgery tools, human implants, etc [...

Wear and Fretting Behavior of Cold Sprayed IN625 Superalloy

The wear and fretting behaviour of IN625 cold spray coatings was analysed and the results are presented. The cold spray conditions were selected in order to obtain coatings with minimum porosity and maximum particles splat. This leads to compact and hard deposited material able to resist wear damaging and to dissipate energy during fretting. The coating’s strength was evaluated through nanoindentation that revealed an increased hardness from the surface toward the substrate. This different hardening behaviour from the coating surface toward the substrate leads to increased resistance to fretting and wear as the maximum stresses increase. This was revealed by scratch tests performed at linearly increasing loads that allowed identifying of the damage mechanisms acting on the coating as the triaxial stresses increase. The hardening behaviour of the coating also influenced the fretting behaviour revealed by the weight loss experienced by varying the fretting maximum load

La chirurgia endoscopica della giunzione cranio-vertebrale

La chirurgia endoscopica della giunzione cranio-vertebral

Preface:CRM- EXTREME: Solutions for Critical Raw Matrials Under Extreme Conditions

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Radiological assessment of the sinus tympani: temporal bone HRCT analyses and surgically related findings.

Purpose To evaluate the morphology of the sinus tympani (ST) based on computed tomography (CT) scans (axial view), describing the findings in a cohort of 148 patients (296 ears), and classifying the prevalence according to our ST classification. To evaluate the surgical prevalence based on the type of ST. To calculate the sensibility and positive predictive value (PPV) of high-resolution computed tomography (HRCT) scans for ST involvement by cholesteatoma. Methods Retrospective review of the radiologic database and surgical reports. Results In total, 98/296 (33.1 %) middle ears presented a radiologic morphology Type A; 185/296 (62.5 %) middle ears presented a radiologic morphology Type B; 13/296 (4.4 %) middle ears presented a radiologic morphology Type C; HRCT showed a sensibility of 91 %, specificity of 65 %, PPV of 68 % and negative predictive value (NPV) of 90 %. Conclusions ST shape and depth can influence surgical preference in cholesteatoma surgery. In the case of a shallower ST, an exclusive endoscopic exploration is chosen; whereas in the case of a deeper ST, a retrofacial approach is usually preferred. HRCT scans demonstrated high sensibility and NPV for ST involvement by cholesteatoma

Design and Manufacturing of Antibacterial Electrospun Polysulfone Membranes Functionalized by Ag Nanocoating via Magnetron Sputtering

Antibacterial properties of engineered materials are important in the transition to a circular economy and societal security, as they are central to many key industrial areas, such as health, food, and water treatment/reclaiming. Nanocoating and electrospinning are two versatile, simple, and low-cost technologies that can be combined into new advanced manufacturing approaches to achieve controlled production of innovative micro- and nano-structured non-woven membranes with antifouling and antibacterial properties. The present study investigates a rational approach to design and manufacture electrospun membranes of polysulfone (PSU) with mechanical properties optimized via combinatorial testing from factorial design of experiments (DOE) and endowed with antimicrobial silver (Ag) nanocoating. Despite the very low amount of Ag deposited as a conformal percolating nanocoating web on the polymer fibers, the antimicrobial resistance assessed against the Gram-negative bacteria E. coli proved to be extremely effective, almost completely inhibiting the microbial proliferation with respect to the reference uncoated PSU membrane. The results are relevant, for example, to improve antifouling behavior in ultrafiltration and reverse osmosis in water treatment

Aluminum-doped zinc oxide coatings on polylactic acid films for antimicrobial food packaging

Polylactic acid (PLA) is safe for contact with food, flexible and highly transparent to visible light, so it is widely used for food packaging applications. The addition of proper surface coatings can provide further advantages, such as antimicrobial activity and optimized optical properties. To this aim, nanostructured aluminum-doped zinc oxide (AZO) coatings were sputter-deposited onto extruded PLA film to functionalize its surface, using different sputtering power. Morphological, structural and optical characterizations were performed on uncoated and coated films, demonstrating uniform coverage of the PLA substrate with polycrystalline AZO coatings and high visible transparency. Spectrophotometric measurements carried out on physiological saline solutions containing the samples revealed low release effects from the uniformly-coated films. Finally, the sputter-coated samples exhibited strong antibacterial activity against Escherichia coli. The results of this preliminary study indicate that AZO-coated PLA films are promising materials for environment-friendly active packaging applications

Ag Functionalization of Al-Doped ZnO Nanostructured Coatings on PLA Substrate for Antibacterial Applications

Developing smart, environmentally friendly, and effective antibacterial surfaces is fundamental to contrast the diffusion of human infections and diseases for applications in the biomedical and food packaging sectors. To this purpose, here we combine aluminum-doped zinc oxide (AZO) and Ag to grow nanostructured composite coatings on bioplastic polylactide (PLA) substrates. The AZO layers are grown by RF magnetron sputtering, and then functionalized with Ag in atomic form by RF magnetron sputtering and in form of nanoparticles by supersonic cluster beam deposition. We compare the morphology, wettability, and antimicrobial performance of the nanostructured coatings obtained by the two methods. The different growth modes in the two techniques used for Ag functionalization are found to produce some differences in the surface morphology, which, however, do not induce significant differences in the wettability and antimicrobial response of the coatings. The antibacterial activity is investigated against Escherichia coli and Staphylococcus aureus as representatives of Gram-negative and Gram-positive bacteria, respectively. A preferential antimicrobial action of Ag on the first species and of AZO on the second one is evidenced. Through their combination, we obtain a hybrid composite coating taking advantage of the synergistic dual action of the two materials deposited, with a total bacterial suppression within few minutes for the first species and few hours for the second one, thus representing a valuable solution as a wide-spectrum bactericidal device. View Full-Tex