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Calibration and Quality Assurance of Sources
Published in W. P. M. Mayles, A. E. Nahum, J.-C. Rosenwald, Handbook of Radiotherapy Physics, 2021
90Y can be formed by nuclear fission and has been used in the form of rods for pituitary ablation (Jones et al. 1963). The source consists of yttrium oxide, pressed and sintered into rod form 1 mm to 2 mm in diameter and 4 mm to 5 mm long. Typically, two or three rods of 150 MBq activity are implanted permanently into the pituitary.
Agents for Microsphere Incorporation: Physicochemical Considerations and Physiological Consequences of Particle Embolization
Published in Neville Willmott, John Daly, Microspheres and Regional Cancer Therapy, 2020
An approach to fulfilling the second condition is incorporation of radionuclide as an integral component37 or covalently bound2,33 to microsphere matrix (Table 6). In this way it is possible to confine the radiation dose to the area where the particles embolize, and so, prevent systemic toxicity from premature release of radionuclide into the circulation. 90Y-yttrium oxide has been incorporated into nonbiodegradable glass microspheres with minimal leaching of radionuclide. Another advantage of 90Y is that it can be incorporated as the oxide of nonradioactive 89Y, which can then be activated to 90Y by neutron bombardment, provided a suitable nuclear reactor is available.37 (See Chapter 1 for details of the development of 90Y-based systems.)
Heterogeneity of Macrophages in Skin Granulomas
Published in Brian J. Nickoloff, Dermal Immune System, 2019
In a preliminary experiment, an inert rare earth metal, 1% yttrium oxide, was injected into an early evolving metal granuloma in one subject. That site, and a control, untreated granuloma site, were biopsied two weeks later. A comparison of their EC types revealed that the number of EC III had increased significantly while EC II fell in the treated lesion (Table 1) and the vesicles frequently appeared like degenerating mitochondria (Figure 11). So it appears that EC II may be able to become EC III under low-grade toxic conditions. However, to be fair, it should be noted that in sarcoidosis or late metal granulomas (Figure 8) the vesicles in EC III seldom look like degenerating mitochondria. Possibly the toxic process is even more subtle and diminished over a prolonged period of time.
Trends and recent developments in pharmacotherapy of acute pancreatitis
Published in Postgraduate Medicine, 2023
Juliana Hey-Hadavi, Prasad Velisetty, Swapnali Mhatre
Nanomedicine is an emerging field that employs nanoparticles as targeted and controlled drug delivery vehicles and is being widely used in therapeutics. Nanoparticles serve as potential drug delivery systems due to their small size and unique chemical and biophysical properties including biocompatibility and biodegradability [90]. In an experimental model of AP, bilirubin encapsulated silk fibrin nanoparticles (BRSNPs) reduced oxidative damage and inflammation by inhibiting NF-κB regulated pro-inflammatory signaling as well as activating cytoprotective redox transcription factor, nuclear factor erythroid 2-related factor 2 [91]. Another experimental study demonstrated that yttrium oxide nanoparticles exerted anti-inflammatory effects and attenuated the severity of AP in mice [92]. Thus, exploring the role of nanomedicine for the treatment of AP may be of clinical interest and warrants further evaluation.
The effect of natural biomolecules on yttrium oxide nanoparticles from a Daphnia magna survival rate perspective
Published in Nanotoxicology, 2023
Egle Kelpsiene, Tingru Chang, Alexander Khort, Katja Bernfur, Inger Odnevall, Tommy Cedervall, Jing Hua
For the latest several decades, rare earth elements (REEs) and their oxides have received attention from the research community and industry because of their unique properties. The total production of REEs was in 2021 277,100 tonnes (Government of Canada. n.d.). For instance, doping of metals with REEs generally improves their physical and chemical characteristics, such as oxidation and corrosion resistance (Smirnov et al. 2016). The use of REE nanoparticles (NPs) in different applications has increased rapidly, especially in bioelectronics due to excellent optical, semiconductor, and magnetic properties (Liu, Hou, and Gao 2014). Yttrium (Y) is one of the REEs element with a global production between ∼10 000 and 14 000 tonnes in 2019 (Zinc 2020). Yttrium oxide (yttria, Y2O3) is used in a wide range of technical applications within electronics, optics, mechanical and metallurgical engineering, as well as in catalysis (Bondar 2000).
Biomechanical evaluation of 3-unit fixed partial dentures on monotype and two-piece zirconia dental implants
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2022
Jefferson David Melo de Matos, Guilherme da Rocha Scalzer Lopes, Leonardo Jiro Nomura Nakano, Nathália de Carvalho Ramos, John Eversong Lucena de Vasconcelos, Marco Antonio Bottino, João Paulo Mendes Tribst
In view of the growing search for aesthetic treatments and metal-free restorative materials, zirconia implants are gaining notoriety, becoming an object of investigation for different rehabilitation configurations and clinical indications (Cionca et al. 2017). The ceramic implant is manufactured from particles of zirconium dioxide (ZrO2), with heat isostatic pressing, allowing the components densification from casting and sintering under high pressure and temperatures (900° C to 1250° C) (Gahlert et al. 2016; Bormann et al. 2018). No thermal sintering process or post-processing occurs after obtaining the final geometry of the implant. This controlled manufacture ensure a high degree of precision and no changes in the structure of the polycrystalline material (Schünemann et al. 2019). The surface of a zirconia implant has microstructures with yttrium oxide, allowing osseointegration with long-term success rates between 96-98% ( Gautam et al. 2016; Zhang and Lawn 2018; Schünemann et al. 2019 ).