High Pressure Brillouin Spectroscopy and X-ray Diffraction of Cerium Dioxide

Simultaneous high-pressure Brillouin spectroscopy and powder X-ray diffraction of cerium dioxide powders are presented at room temperature to a pressure of 45 GPa. Micro- and nanocrystalline powders are studied and the density, acoustic velocities and elastic moduli determined. In contrast to recent reports of anomalous compressibility and strength in nanocrystalline cerium dioxide, the acoustic velocities are found to be insensitive to grain size and enhanced strength is not observed in nanocrystalline CeO2. Discrepancies in the bulk moduli derived from Brillouin and powder X-ray diffraction studies suggest that the properties of CeO2 are sensitive to the hydrostaticity of its environment. Our Brillouin data give the shear modulus, G0 = 63 (3) GPa, and adiabatic bulk modulus, KS0 = 142 (9) GPa, which is considerably lower than the isothermal bulk modulus, KT0∼ 230 GPa, determined by high-pressure X-ray diffraction experiments.

Meat productivity of quails by feeding nanocrystalline cerium dioxide

The use of nanomaterials in poultry farming has become increasingly popular as feed additives capable of increasing the productivity of the herd. Nanocrystalline cerium dioxide belongs to nanomaterials with a broad spectrum of activity. Owing to their oxygen non-stoichiometry and low toxicity, cerium dioxide nanoparticles are a very promising object for agriculture. The paper presents the results of studying the meat productivity of quails of the Pharaoh breed when drinking nanocrystalline cerium dioxide in the composition of the feed additive “Nanocerium”. The study was carried out on quails during the rearing period from 14 to 49 days. For the experiment, two groups (control and experimental) of 24 heads each were formed from one day old poultry. The quails were kept in a vivarium, in cage batteries, subject to the accepted microclimate conditions. Poultry of both groups received compound feed, developed taking into account age and physiological characteristics. With drinking water, the of the experimental group additionally received nanocrystalline cerium dioxide as part of the feed additive “Nanocerium” at a dose of 8,6 mg per liter of water for 35 days. The quail population was counted and weighed weekly, starting from the day-old age. The following indicators were determined: safety, dynamics of live weight, average daily gain in live weight. According to the results of the control slaughter and anatomical cutting, the weight of the carcass and the weight of the edible part were determined. Slaughter qualities and morphological composition of quail carcasses were determined by anatomical cutting with the measurement of the following parameters: pre-slaughter weight, half-battered carcass weight, carcass patrana, slaughter yield, weight of edible parts. Drinking the feed additive “Nanocerium” by young quails increased their safety by 4.17%, live weight and absolute average daily gain by 20.3 g and 0.48 g (P <0.05), respectively. The addition of NDC quails to drinking water contributed to an increase in their pre-slaughter weight by 19.3 g, half-gutted carcass by 18.0 g, and gutted by 17.5 g in comparison with the control group. The quail carcasses of the experimental group had a higher yield of edible parts in comparison with the poultry that consumed pure water. Key words: quail, nanocrystalline cerium dioxide, safety, body mass, gain, slaughter rates, output of edible part.

Influence of CeO2 nanoparticles on seed germination and synthesis of phenols in spruce seedlings

Modern technologies make it possible to obtain nanoparticles of biogenic metals for use as an additional source of micronutrient for plants. However, the complexity of mass application of nanosized metal particles and their oxides is due to the significant differences in physicochemical properties of nanocrystalline structures which are dependent on production technology, nanoparticle size, surface charge (-potential), and stabilization methods. The biocompatibility and nature of nanoparticles has an impact on living organisms. Regarding the effectiveness and feasibility of using cerium dioxide nanoparticles in crop practice, there is no definitive conclusion. Due to difficulty in the preparation of planting material for seedlings of conifers, the study of the effect of nanocrystalline cerium dioxide on plants is not well researched. The aim of our research was to study the effect of nanocrystalline cerium dioxide solution on the germination of spruce seeds and then to evaluate its effect on the synthesis of phenols as components of the antioxidant system within seedlings. The research used methods for determining the germination energy and seed similarities. Other methods used in this research were determining the content of phenolic compounds, flavonoids, and phenolic antioxidants. The results showed that nanocrystalline cerium dioxide in a concentration of solution from 0.1 to 1.0 mg/mL stimulates the germination of spruce seeds. Under the influence of nanoparticles at a concentration of 0.1 mg/L in the tissues of spruce seedlings increases the content of phenolic compounds. The increase in antioxidant activity of phenols in seedling tissues while decreasing their total amount at a concentration of nanocrystalline cerium dioxide from 0.5 to 1.0 mg/L occurs when increasing the total pool of flavonoids, which are determined by high antioxidant activity. Nanocrystalline cerium dioxide is a promising material for stimulating germination energy and on the overall germination of spruce seeds.

Effectiveness of nanocrystalline cerium dioxide for secondary prevention of inflammatory periodontal diseases in young individuals with obesity

Obesity is a non-infectious pandemic, largely associated with oral diseases development. Oxidative stress is one of the crucial mechanisms in the development of inflammatory periodontal diseases in obesity. Nanomedicine is a highly promising to alleviate pbesity and associated conditions. The aim was to study the influence of cerium dioxide nanoparticles on periodontal tissues of patients with diverse values of BMI and assess changes of periodontal tissues. We included 125 young Ukrainian individuals of both sexes (18-22 years old), divided into four groups according to Body mass index (BMI). Initial oral status was detected with index assessment that include the determination of caries intensity by DMFT index, oral hygiene determination (Green-Vermillion index), periodontal tissues (Rateitchak index), PMA (Parma), CPI (Leus), PBI (Saxer and Muhlemann). The periodontograma was completed for all patients. After the initial checkup all examined patients with generalized catarrhal gingivitis were randomly divided into two groups: treated with «Cerera» (the active substance is nanoparticles of cerium dioxide 2-7 nm in concentration of 140 mcg/ml that were stabilized with sodium citrate) per os for 10 drops every day in the morning diluted in 50 ml of water for 10 days and controls. Patients with 1st and 2nd degree obesity have a significantly higher grade of periodontal alteration compared with normal BMI and overweight (values of CPI 1.7±0.9 and 1.66±0.12 vs 1.33±0.11 and 1.42±0.11 respectively). The intensity and the prevalence of gingiva inflammation assessed by PMA and PBI index were significantly higher in obese individuals. In all overweight patients the level of catalase activity was significantly lower than in patients with normal values of BMI. The administration of «Cerera» significantly increased the activity of catalase regardless of BMI, significantly changed the values of gingival inflammation indexes; the severity of inflammatory process became less intensive vs baseline (determined by PBI values before 17.6%±2.1 and 7.8%±2.1 after treatment; in the 4th group the values of PBI had declined significantly by 1.6 times). After the 10 days administration of «Cerera» the content of GAG and fucose in oral liquid of all obese individuals significantly decreased; lipid oxidation parameters decreased in excessive obesity: TBA-active products levels in patients with BMI 35.00-39.99 kg/сm2 dropped down from 53.9±2.11 μmol/L to 47.43±2.29 μmol/L. Cerium dioxide nanoparticles demonstrate high effectiveness against inflammatory changes in periodontal tissues in obese patients. The mechanisms of action of cerium dioxide nanoparticles in the periodontal structures are needed to be precisely determined in further studies.

Morphometry Results of Formed Osteodefects When Using Nanocrystalline CeO2 in the Early Stages of Regeneration

This paper studies of the use of nanocrystalline cerium dioxide with artificially formed bone tissue defects. The results of morphometry confirmed the antialterative effect in the early stages of the reparative process of damaged bone tissue. When using calcium hydroxide with nanodispersed cerium dioxide, the nature of osteogenesis should be characterized as activated. In case of damage to the dentin of the roots of the teeth, dentinogenesis in presence of CeO2 occurs with the formation of a combined dentin and bone regenerates. Little or no studies of dentinogenesis in presence of CeO2 were performed by other researchers.