This study was performed to evaluate the effect of cyclic precalcification treatment on the improvement of bioactivity of Ti-6Al-4V mini-screws. The cutted plate-shaped specimens of 10 mm × 10 mm dimensions, and a mini-screw with a diameter of 1.6 mm × 6.0 mm in length were used. Anodic oxidation treatment was carried out in a glycerol electrolyte solution containing 20 wt% H2O and 1.5 wt% NH 4F. Voltage of 20 V with current density of 20 mA/cm2 was applied for 1 hour to form a nanotube TiO2 layer. Afterwards, to improve the bioactivity, specimens were immersed in 0.5 vol% silica aqueous solution at 37 ℃ for 5 minutes, and then cyclic precalcification treatment with 0.05 M NH 4H2PO4and 0.01 M Ca(OH)2 solution at 90 ℃ was repeated with 20 times. Based on surface treatment the experimental groups were divided into three groups, namely untreated group (UT), anodized and heat-treated group (AH), and anodized, silica-treated, cyclic precalcified and heat-treated group (ASPH). There were TiO2 nanotubes completely self-aligned and formed in a dense structure on the surface after anodic oxidation treatment. A fine granular cluster layer of hydroxyapatite and octacalcium phosphate were formed on the surface after the cyclic precalcification treatment. As a result of immersion test in the simulated body fluid (SBF), bioactivity was confirmed to be improved by the precipitation of protrusions appearing at the initial stage of formation of hydroxyapatite.

BACKGROUND AND PURPOSE: The one-day rivastigmine patch is reportedly well tolerated and has minimal side effects. However, Asian patients show more side effects than those in Western countries. We evaluated tolerability of the rivastigmine patch in South Korean patients with Alzheimer's disease (AD) and the specific factors affecting adverse events of the skin. METHODS: A 6-month, open labeled, multi-centered, observational study was carried out in 440 patients with probable AD from July 2009 to September 2010 (NCT01312363). RESULTS: A total of 25.9% of the patients experienced adverse skin events at the rivastigmine patch application site and 17.0% discontinued treatment due to adverse events at the skin application site. The most common adverse events were itching and erythema. Patients with an allergic history and users of electric heating appliances reported skin discomfort. Older age was associated with discontinuing treatment. CONCLUSION: These results suggest that the rivastigmine patch induced some adverse skin events and may contribute to understanding and improving skin tolerability to the rivastigmine patch.
Alzheimer Disease* ; Asian Continental Ancestry Group ; Erythema ; Heating ; Hot Temperature ; Humans ; Observational Study ; Pruritus ; Skin* ; Rivastigmine