BACKGROUND:Magnetic bone cements have been used to treat bone metastasis in Japan, which are made by adding Fe3O4 nanoparticles to bone cements. Magnetic bone cements containing micron carbonyl iron powder have not been reported.
OBJECTIVE:To prepare polymethylmethacrylate-based cements containing carbonyl iron powder, and to test the magnetic characterizations and the heat-generating abilities of al samples according to ISO 5833 standard in vitro. METHODS:The carbonyl iron powder was mixed with polymethylmethacrylate-based bone cement power to prepare magnetic bone cements containing 0%, 20%, 30%, 40%, and 50%carbonyl iron powder, respectively. The setting time, polymerization temperature, compressive strength, magnetic property and in vitro heat-generating ability were tested.
RESULTS AND CONCLUSION:The setting time and polymerization temperature were increased with the increased content of carbonyl iron powder. The highest polymerization temperature of each sample was 65-70 ℃. The increased content of carbonyl iron power could not change the highest polymerization temperature but delay its appearance. The compressive strength of each sample was higher than 60 MPa, and moreover, the compressive strength of the pure polymethylmethacrylate-based bone cement was higher than 60 MPa, which met the ISO 5833 standard. The saturation magnetic intensity was increased with the increasing of carbonyl iron power content. The heat-generating ability of magnetic bone cements had a positive correlation with the magnetic field strength and the content of carbonyl iron powder.

ObjectiveTo explore the related factors of troublemaking behaviors among patients with mental disorders induced by amphetamine-type stimulants （ATS）， and to provide references for the formulation of relevant intervention measures for ATS-induced mental disorders. MethodsA total of 105 patients who met the diagnostic criteria of International Classification of Diseases， tenth edition （ICD-10） for ATS-induced mental disorders were included， and classified into troublemaking group and non-troublemaking group. The general demographic data and clinical data of the selected individuals were collected， and all patients were assessed using Social Support Rating Scale （SSRS）. Then univariate analysis and multivariate Logistic regression model were used to screen the related factors of troublemaking behaviors. ResultsThe scores of SSRS， objective support dimension and social support utilization dimension were significantly lower in troublemaking group than those in non-troublemaking group， with statistical differences ［（24.10±6.59） vs. （28.94±5.59）， t=3.364， P=0.001； （5.50±1.96） vs. （8.20±2.13）， t=5.183， P<0.01； （4.60±2.26） vs. （6.28±1.90）， t=3.435， P=0.001］. Multivariate Logistic regression analysis showed that male （OR=6.061， P=0.014） was a risk factor， while high social support level （OR=0.873， P=0.018） was the protective factor for troublemaking behaviors among patients with ATS-induced mental disorders. ConclusionPatients with ATS-induced mental disorders of the males and with low social support level are at high risk of troublemaking behaviors.