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ObjectiveTo compare the stability and clinical applicability of a novel orthodontic mini-implant design (N2) with the most widely used commercially available (CA) design.Materials and methodsTwo groups of mini-implants were tested: a CA design (1.5-mm diameter, 6-mm length) and N2 (3-mm diameter, 2-mm length, tapered shape). Implants were inserted in bone blocks of cortical bone simulation with varying densities (20 pounds per cubic foot [pcf], 30 pcf, and 40 pcf). A torque test was used to measure maximum insertion torque (MIT) and maximum removal torque (MRT). Compression and tension force vectors were applied at angles of 10°, 20°, 30°, and 40° using customized load pins to determine primary stability.ResultsMean MIT and MRT were higher in the N2 than the CA design at all three cortical bone densities except MRT in 20 pcf bone (not statistically significant). The mean compression force required to displace the N2 at all distances and angulations was greater for the N2 than the CA design. At all displacement distances, the highest mean tension force required for N2 displacement was at 10° angulation, whereas at 30° and 40°, the mean tension force required to displace the CA design was greater.ConclusionsThe primary stability of the N2 is superior to that of the CA design and is promising for both orthodontic and orthopedic clinical applicability, especially under compression force. The short length of the N2 reduces risk of damage to anatomic structures and root proximity during placement and orthodontic treatment. The stability of the N2 may be compromised in areas of high bone density and highly angulated tension force.

The cytotoxicity of TiO2 nanoparticles are well-known, but the particle size-dependent induction of ER stress and apoptosis by TiO2 in hepatocytes has not been elucidated clearly. In the present study, we investigated whether a fine TiO2 particle and two types of TiO2 nanoparticles induce ER stress and apoptosis differently in HepG2 cells. A particle size-dependent decrease in cell viability was observed after exposure to the TiO2 particles. The levels of ER stress-related proteins (BiP, CHOP, ATF6α, and p-PERK) were increased with decreasing particle size. TiO2 particles induced ER stress-mediated apoptosis in a particle size-dependent manner as seen by a decrease in the expression of Bcl-2, and increases in the expression of Bax, caspase-12, and cleaved caspase-3. These results indicated that the cytotoxicity produced by TiO2 particles was related to particle size, with smaller TiO2 nanoparticles producing greater toxic effects involving ER stress and apoptosis in the HepG2 cells. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents bubble-point pressure data for CO2 in ionic liquids 1-hexyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([HMP][Tf2N]) and 1-octyl-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([OMP][Tf2N]) at pressures up to approximately 62MPa and temperatures between 303.15 and 373.15K. The solubility of CO2 in ionic liquids was measured with a high-pressure variable-volume view cell. At high CO2 concentrations in ionic liquids, the equilibrium pressure increased sharply with increasing CO2 concentrations while the solubility of CO2 in the ionic liquids decreased commensurate to increases in temperature. We have observed that in the [Tf2N] anion-based ionic liquids, the shorter the alkyl group chain in cation is, the larger the solubility of CO2 in ionic liquid become. The experimental data for the CO2 +ionic liquid system were relatively well correlated using the Peng–Robinson equation of state. [Copyright &y& Elsevier]