73 results match your criteria: "Technological Institute of Aeronautics[Affiliation]"

Objectives: To characterize two experimental zirconia bilayer materials compared to their monolithic controls, before and after hydrothermal aging.

Methods: Commercial zirconia powders were utilized to fabricate two bilayer materials: 3Y-TZP+ 5Y-PSZ (3Y+5Y/BI) and 4Y-PSZ+ 5Y-PSZ (4Y+5Y/BI), alongside control groups 3Y-TZP (3Y/C), 4Y-PSZ (4Y/C), and 5Y-PSZ (5Y/C). Compacted specimens were sintered (1550 °C- 2 h, 3 °C/min), and half of them underwent hydrothermal aging (134 °C-20h, 2.

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There is extensive use of nondestructive test (NDT) inspections on aircraft, and many techniques nowadays exist to inspect failures and cracks in their structures. Moreover, NDT inspections are part of a more general structural health monitoring (SHM) system, where cutting-edge technologies are needed as powerful resources to achieve high performance. The high-performance aspects of SHM systems are response time, power consumption, and usability, which are difficult to achieve because of the system's complexity.

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Article Synopsis
  • New silver(I) complexes of 5-(trifluoromethyl)uracil (5TFMU) and 6-(trifluoromethyl)uracil (6TFMU) were synthesized and characterized for their antibacterial and antiproliferative activities.
  • Structural analyses indicated that 5TFMU acts as a tridentate ligand forming distinct coordination environments, while 6TFMU forms a more complex polymeric structure with multiple coordination sites.
  • Both complexes showed modest antibacterial activity, with Ag-6TFMU displaying better efficacy against certain tumor cells, particularly in prostate and kidney cell lines, while Ag-5TFMU had a broader activity profile against various tumor cells but lacked selectivity.
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Fatigue strength of bilayer yttria-stabilized zirconia after low-temperature degradation.

J Mech Behav Biomed Mater

December 2024

Laboratory of Plasma and Process, Technological Institute of Aeronautics, Praça Marechal Eduardo Gomes, 50, Vila das Acácias, São José dos Campos, SP, 12228-900, Brazil.

This study examined the impact of interfacial interactions on bilayer yttria-stabilized zirconia (YSZ) used in dental restorations. In-house bilayer structures of 3YSZ and 5YSZ composition underwent hydrothermal degradation to compare the properties of control and low-temperature degradation (LTD) treated groups. Biaxial flexural strength via piston-on-three-balls, staircase fatigue strength over 10 cycles at 15 Hz, phase characterization and quantification through XRD and Rietveld refinement, and fractography were conducted.

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Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) nanofibers embedded with borate glasses of 45B5 composition doped with Co, Cu, and Zn (46.1 B₂O₃26.9-X CaO24.

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Characterization of a hydrothermally aged experimental alumina-toughened zirconia composite.

Dent Mater

September 2024

Department of Prosthodontics and Periodontology, Bauru School of Dentistry, University of Sao Paulo, Bauru 17012-901, SP, Brazil.

Objectives: To assess the effects of different aging protocols on chemical, physical, and mechanical properties of an experimental ATZ composite compared to a zirconia.

Methods: Disc-shaped specimens were obtained through uniaxial pressing of commercial powders (Tosoh), ATZ comprised of 80%ZrO/20%AlO (TZ-3YS20AB) and 3Y-TZP (3Y-SBE). The specimens of each material were divided into different groups according to the aging protocol: immediate, autoclave aging and hydrothermal reactor aging.

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The field of tissue engineering has witnessed significant advancements in recent years, driven by the pursuit of innovative solutions to address the challenges of bone regeneration. In this study, we developed an electrospun composite scaffold for bone tissue engineering. The composite scaffold is made of a blend of poly(L-lactide-co-ε-caprolactone) (PLCL) and polyethylene glycol (PEG), with the incorporation of calcined and lyophilized silicate-chlorinated bioactive glass (BG) particles.

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Osseointegration of implant surfaces in metabolic syndrome and type-2 diabetes mellitus.

J Biomed Mater Res B Appl Biomater

February 2024

Biomaterials Division, NYU Dentistry, New York, New York, USA.

This in vivo study evaluated the bone healing response around endosteal implants with varying surface topography/chemistry in a preclinical, large transitional model induced with metabolic syndrome (MS) and type-2 diabetes mellitus (T2DM). Fifteen Göttingen minipigs were randomly distributed into two groups: (i) control (normal diet, n = 5) and (ii) O/MS (cafeteria diet for obesity induction, n = 10). Following obesity induction, five minipigs from the obese/metabolic syndrome (O/MS) group were further allocated, randomly, into the third experimental group: (iii) T2DM (cafeteria diet + streptozotocin).

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Development, characterization, and biological study of bioglass coatings 45S5 and BioK on zirconia implant surfaces.

J Biomed Mater Res B Appl Biomater

February 2024

Department of Bioscience and Oral Diagnosis, Institute of Science and Technology, São Paulo State University (UNESP), Avenida Engenheiro Francisco José Longo, São José dos Campos, SP, Brazil.

Zirconia implants are gaining attention as a viable alternative to titanium implants due to their comparable osseointegration development, improved soft tissue adaptation, and enhanced aesthetics. An encouraging avenue for improving zirconia implant properties involves the potential application of bioactive coatings to their surfaces. These coatings have shown potential for inducing hydroxyapatite formation, crucial for bone proliferation, and improving implant mechanical properties.

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Zirconia multilayer presents promising prospects, but there is scarce information about its microstructural and mechanical characterization. Therefore, this study sought to produce them in-house and to perform their characterization by comprising four groups of specimens to assess the biaxial flexural strength, microhardness, fracture toughness, phase characterization and quantification, fractography, and microstructural features. Weibull analysis was performed to determine the Weibull modulus and characteristic strength.

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Objectives: To process an alumina-toughened zirconia (ATZ) nanocomposite and to characterize its crystalline phases, microstructure, residual stress, mechanical and optical properties before and after two different artificial aging methodologies.

Methods: Disc-shaped specimens were obtained through uniaxial pressing of a commercial ATZ powder comprised of 80%ZrO / 20%AlO, with a particle size of 50 nm and 150 nm, respectively. Sintering was performed at 1500ºC for 2 h.

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Evaluation of the Effects of Radiation Therapy on Muscle Contractibility and Skin Healing: An Experimental Study of the Cancer Treatment Implications.

Life (Basel)

August 2023

Department of Bioscience and Oral Diagnosis, Institute of Science and Technology, São Paulo State University (UNESP), Avenida Engenheiro Francisco José Longo, 777, Jardim São Dimas, São José dos Campos 12245-001, SP, Brazil.

Background: Radiotherapy can affect healthy cells, resulting in side effects. This study aimed to assess the impact of radiotherapy on soft tissue in surgical wounds in rats.

Methods: The animals were divided into four groups: control (S) group without irradiation, immediate irradiation (S-IIr) group receiving irradiation right after surgery, late irradiation (S-LIr) group receiving irradiation four weeks after surgery, and early irradiation (Ir-S) group receiving irradiation before surgery.

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Article Synopsis
  • Bisphosphonate therapy, specifically with zoledronate (ZA), is linked to medication-related osteonecrosis of the jaw (ONJ), but this study investigates potential sex differences in ONJ development and bone biomechanical changes.
  • A mouse model was used to examine the effects of ZA on mineralized tissues, considering both sex (female/male) and treatment (ZA/Saline) factors, revealing notable differences in bone density and biomechanical properties between sexes.
  • The findings indicate that while ZA reduces bone density and alters biomechanical characteristics, the occurrence of ONJ is similar across sexes, with no synergistic effect between sex and treatment observed.
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The development of bioactive membranes with bone repair properties is great interest in the field of tissue engineering. In this study, we aimed to fabricate and characterize a composite membrane composed of sol-gel synthesized bioceramics and electrospun polycaprolactone (PCL) fibers for bone tissue regeneration applications. The bioceramics were prepared using the sol-gel method with nitrate (N) and chloride (CL) as precursors.

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Nanocellulose-based porous materials: Regulation and pathway to commercialization in regenerative medicine.

Bioact Mater

November 2023

Department of Bioproducts and Biosystems, School of Chemical Engineering, Aalto University, P. O. Box 16300, Aalto, Espoo, FIN-00076, Finland.

We review the recent progress that have led to the development of porous materials based on cellulose nanostructures found in plants and other resources. In light of the properties that emerge from the chemistry, shape and structural control, we discuss some of the most promising uses of a plant-based material, nanocellulose, in regenerative medicine. Following a brief discussion about the fundamental aspects of self-assembly of nanocellulose precursors, we review the key strategies needed for material synthesis and to adjust the architecture of the materials (using three-dimensional printing, freeze-casted porous materials, and electrospinning) according to their uses in tissue engineering, artificial organs, controlled drug delivery and wound healing systems, among others.

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The objective of this study was to investigate the osteogenic and antimicrobial effect of bioactive glass S53P4 incorporated into β-tricalcium phosphate (β-TCP) scaffolds in vitro and the bone neoformation in vivo. β-TCP and β-TCP/S53P4 scaffolds were prepared by the gel casting method. Samples were morphologically and physically characterized through X-ray diffraction (XRD) and scanning electron microscope (SEM).

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In this study, different plasma-activated liquids were evaluated for their antimicrobial effects against , as well as for their cytotoxicity on mammalian cells. The PALs were prepared from distilled (DIS), deionized (DI), filtered (FIL), and tap (TAP) water. Additionally, 0.

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The effects of processing parameters on conventional molding techniques are well-known. However, the fabrication of a carbon fibre (CF)/epoxy composite via additive manufacturing (AM) is in the early development stages relative to fabrications based on resin infusion. Accordingly, we introduce predictions of the flexural strength, modulus, and strain for high-performance 3D printable CF/epoxy composites.

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Electrospun polylactic acid scaffolds with strontium- and cobalt-doped bioglass for potential use in bone tissue engineering applications.

J Biomed Mater Res B Appl Biomater

January 2023

Department of Dental Materials and Prosthodontics, Institute of Science and Technology of São José dos Campos, São Paulo State University (UNESP), Institute of Science and Technology of São José dos Campos, São Paulo State University (UNESP), São José dos Campos, São Paulo, Brazil.

The development of nanoscale biomaterials associated with polymers has been growing over the years, due to their important structural characteristics for applications in biological systems. The present study aimed to produce and test polymeric scaffolds composed of polylactic acid (PLA) fibers associated with a 58S bioglass doped with therapeutic ions for use in tissue engineering. Three 58S Bioglass was obtained by the sol-gel route, pure and doped with 5% strontium and cobalt ions.

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The objective was to synthesize and characterize fine polycaprolactone (PCL) fibers associated with a new 58S bioglass obtained by the precipitated sol-gel route, produced by the electrospinning process in order to incorporate therapeutic ions (Mg and Li). In PCL/acetone solutions were added 7% pure bioglass, bioglass doped with Mg(NO ) and Li CO and were subjected to electrospinning process. The fibers obtained were characterized morphologically, chemically and biologically.

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Masking ability of resin composites: Effect of the layering strategy and substrate color.

J Esthet Restor Dent

December 2022

Post-Graduate Program in Oral Science, Division of Restorative Dentistry, Federal University of Santa Maria, Santa Maria, Rio Grande do Sul, Brazil.

Objective: To evaluate the effect of layering strategy and substrate color on the masking ability of resin composites.

Materials And Methods: A1-shaded specimens from Charisma Diamond and Filtek Z350XT were produced using different layering strategies. Color measurements were made by a reflectance spectrophotometer over A2, C2, A3.

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Nitrogen pollution is one of Brazil's most threatening and challenging environmental problems, caused mainly by productive activities aimed at meeting the demand of food, energy, and housing by a fast-growing population. Sustainable nitrogen management involves optimizing the beneficial effects of reactive nitrogen (N) use and, at the same time, mitigating the negative impacts of its excess on the environment and human health. Here we conduct an assessment of nitrogen sustainability in Brazil from 2000 to 2018 applying the Entropy Weight Method (EWM) to a set of nitrogen-related indicators within four subsystems: environmental, economic, social, and institutional.

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Water as Veneering Modeling Liquid Affects Microhardness of Glassy Matrix Veneering Ceramic.

Eur J Prosthodont Restor Dent

November 2022

Division of Dental Biomaterials, Center for Dental and Oral Medicine, University of Zürich, Plattenstrasse 11, 8032 Zürich, Switzerland.

Purpose/aim: To evaluate the effect of different veneering liquids used for modeling on microhardness, fracture toughness and biaxial flexural strength of a glass-veneering ceramic.

Material And Methods: The manufacturer recommended modeling liquid (ML), distilled water (DW), isopropyl alcohol (IA), 0.5% (P05), 1% (P1), and 2% (P2) polyethylene glycol solutions were mixed with feldspathic ceramic powder to form disc-shaped samples (n=20, 15 mm × 1.

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The management of radioactive waste is a worldwide activity based on the guidelines of the International Atomic Energy Agency (IAEA), and all stages of management require scientifically proven methods for possible deployment. The management of radioactive waste is a huge challenge due to the high risk in the collection, gathering, transport, handling, and storage. In this study, a thermal plasma treatment process was evaluated for its efficiency to process solid radioactive waste.

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Objectives: To evaluate the effect of the ceramic processing and aging method on the microstructure, optical, and mechanical properties of a third generation ultra-translucent zirconia, yttria partially stabilized zirconia (5Y-PSZ).

Methods: In-house discs were obtained through uniaxial and isostatic pressing an ultra-translucent Y-PSZ powder and sintering at 1450 °C for 2 h. As control, a commercial disc was milled from pre-sintered blocks fabricated with the same 5Y-PSZ powder through isostatic pressing and sintered under the same protocol.

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