Mechanical characterization and creep strengthening of AZ91 magnesium alloy by addition of yttrium oxide nanoparticles

In the current research, the authors have attempted to improve the mechanical properties and creep behavior of the magnesium alloy Mg–9Al–1Zn (AZ91) in three different stress levels. To this end, the present study investigated experimentally the addition effects of different values of yttrium oxide nanoparticles to the AZ91. In this regard, weight percentages of 0.5%, 1%, 1.5%, and 2% nanoparticles were added to the material using the vortex casting method. Then, various test specimens were fabricated based on the ASTM standards by utilizing a Computer Numerical Control lathe machine. Different experiments were performed, and the results of different groups were compared with each other. The results revealed that the addition of yttrium oxide (Y2O3) nanoparticles increases the strength of AZ91 magnesium alloy until the nanoparticles do not clump in the microstructure. In other words, the tensile strength of the nanocomposite increased by adding nanoparticles up to 1.5%, but by adding 2% of nanoparticles, we found that the tensile strength is lower than that of pure magnesium. Moreover, one of the most important achievements of this study is that if the nanoparticles do not clump in the material microstructure, the addition of Y2O3 increases the rate of stable creep (the secondary creep stage). Also, the experimental results indicated that the highest stable creep rate is related to the nanocomposite with 1.5% yttrium oxide nanoparticles. Furthermore, the maximum hardness of the material was obtained in the same case.

Surface binding energy and erosion coefficient on the nanoyttrium oxide under ionization irradiation

Using the conditions obtained from various simple and complex models, the energy of the surface area was calculated with the help of electronic structural transitions and thermo-sublimation approximations occurring in yttrium oxide nanoparticles irradiated with different energy deuterium ions. The depth of penetration of deuterium ions of different energies into the yttrium oxide sample, the rate of energy loss, and the energy of the surface area under the influence of temperature sublimation were determined using basic methods. In addition, the screening radius and erosion rate were determined using the Sigmund and Thomas–Fermi shielding function.

Antiulcerogenic activity of Yttrium and Copper oxide nanoparticles

Gastric ulcer is an excavation of mucosa and extending to submucosal layers due to increased gastric secretion, generation of free radicals and imbalance between protective factors and aggravating factors. The present study aimed to screen yttrium and copper oxide nanoparticles for antiulcerogenic activity. Metal oxide nanoparticles were evaluated for various biological activities considering their high surface area to volume ratio, different oxidative states, cell permeability etc. Various studies have proved metal oxide nanoparticles to be beneficial in various ailments due to their antioxidant, antibacterial, and other pharmacological activities. Nanoparticles prepared using biogenic methods were relatively more biocompatible and less toxic compared to conventional methods of synthesis. In the present study, green synthesized yttrium and copper oxide nanoparticles were evaluated for acute toxicity, antioxidant, proton pump inhibition and antiulcerogenic activity. In vitro antioxidant activity by DPPH, nitric oxide scavenging methods and H+K+ATPase assay was performed to evaluate the mechanism of action. Synthesized nanoparticles have shown no signs of acute toxicity as per OECD 423. Pyloric ligation method was performed to evaluate gastric volume, pH and ulcer severity. The present study revealed the dose-dependent antiulcer potential of yttrium oxide nanoparticles at doses of 2mg/kg and 20mg/kg. Antisecretory action of yttrium and copper oxides were evident from in vitro H+K+ATPase activity and inhibition of gastric volume. Antioxidant activities of yttrium oxide nanoparticles indicate gastric mucosal protection by free radical scavenging action. Copper oxide nanoparticles produced antisecretory activity but produced mucosal damage and hemorrhage at a dose of 20mg/kg.

Influence of pH on Structural, Morphological, Optical, Photocatalytic, and Antibacterial Properties of Yttrium Oxide Nanoparticles via Co-Precipitation Method

Yttrium oxide nanoparticles with multiform morphologies have been synthesized by the co-precipitation method. The structure, morphology, functional groups, optical and photoluminescence properties were examined through X-ray diffraction (XRD), Scanning electron microscope (SEM), Fourier transform infrared spectrometer (FTIR), UV-Visible (UV-Vis), Photoluminescence spectra (PL). The XRD patterns obtained for the samples synthesized at various pH values confirmed the cubic structure of Y2O3. The patterns obtained on the samples at pH values of 8 and 9 appeared as have sharp peaks suggested, that the samples were well crystallized. From UV-vis spectra, it revealed that the bandgap energy exhibits a blue shift in the absorption edge for the samples with the increase of pH due to their changing morphologies and surface structures. In the PL spectra, the obtained Y2O3 samples demonstrate an intense and bright UV and blue emission under the excitation wavelength range of 250 nm. The photocatalytic degradation of the Y2O3 nanostructure was studied against the Methylene blue (MB) dye under sunlight irradiation. The results showed good recital under solar light irradiation. Further, the antimicrobial activities of Y2O3 nanostructure against foodborne pathogens (Staphylococcus aureus and Salmonella typhi) were examined by using the disc diffusion method. Moreover, the Y2O3 nanostructure was found to be biocompatible.

Antioxidant and Anti-inflammatory Properties of Yttrium Oxide Nanoparticles: New Insights into Alleviating Diabetes

Background: Diabetes mellitus is a metabolic disease that requires immediate attention. Oxidative stress that leads to the generation of reactive oxygen species is a contributing factor to the disease progression. Yttrium oxide nanoparticles (Y2O3 NPs) have a profound effect on alleviating oxidative damage. Methods: The literature related to Y2O3 NPs and oxidative stress has been thoroughly searched using PubMed and Scopus databases and relevant studies from inception until August 2020 were included in this scoping review. Results: Y2O3 NPs altered oxidative stress-related biochemical parameters in different disease models including diabetes. Conclusion: Although Y2O3 NPs are a promising antidiabetic agent due to their antioxidant and anti-inflammatory properties, more studies are required to further elucidate the pharmacological and toxicological properties of these nanoparticles.

Cerium and Yttrium Oxide Nanoparticles and Nano-selenium Produce Protective Effects Against H2O2-induced Oxidative Stress in Pancreatic Beta Cells by Modulating Mitochondrial Dysfunction

Background: Type 1 diabetes mellitus is characterized by the destruction of insulin- producing Beta cells in the pancreas. Researchers hope that islet transplantation will help to patients with insulin-dependent diabetes mellitus (IDDM). Oxidative stress is the most important challenge that beta cells face to it after isolation, and mitochondrial dysfunction is a crucial mediator in beta cells death. Hence, therapeutic approaches can shift to antioxidants through the application of nanoparticles such as cerium and yttrium oxide nanoparticles (Cer and Ytt Ox NPs) and nano-selenium (Nan Se). Objectives: This study evaluates the effects of Cer and Ytt Ox NPs and Nan Se on H2O2- induced oxidative stress in pancreatic beta cells with focus on mitochondrial dysfunction pathway. Methods: CRI-D2 beta-cell line were pretreated with Cer Ox NPs (200 µM) + Ytt Ox NPs (0.5 µg/mL) for 3 days and/or Nan Se (0.01 µM) for 1 day. Then markers of oxidative stress, mitochondrial dysfunction, insulin and glucagon secretion were measured. Results: We reported a decrease in H2O2-induced reactive oxygen species (ROS) level and glucagon secretion, and an increase in H2O2-reduced ATP/ADP ratio, MMP, as well as UCP2 protein expression, and insulin secretion by pretreatment of CRI-D2 cells with Cer and Ytt Ox NPs and/or Nan Se. Conclusion: We found maximum protective effect with Cer and Ytt Ox NPs on CRI-D2 beta-cell line exposed by H2O2 for keeping beta cells alive until transplant whereas combination of Cer and Ytt Ox NPs and Nan Se had very little protective effect in this condition.