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We report on novel vortex-core reversal dynamics in nano-spheres of single-vortex spin configuration as revealed by micromagnetic simulations combined with analytical derivations. When the frequency of an AC magnetic field is tuned to the frequency of the vortex-core precession around the direction of a given static field, oscillatory vortex-core reversals occur, and additionally, the frequency is found to change with both the strength of the applied AC field and the particle size. Such resonant vortex-core reversals in nano-spheres may provide a new and efficient means of energy absorption by, and emission from, magnetic nanoparticles, which system can be effectively implemented in bio-applications such as magnetic hyperthermia.
RESUMO
BACKGROUND AND OBJECTIVES: Heart failure rarely occurs in patients with thyrotoxicosis (6%), with half of the cases having left ventricular dysfunction (LVD). Although a few studies reported isolated right heart failure in thyrotoxicosis, there has been no evaluation of relationship between LVD and right ventricular dysfunction (RVD). SUBJECTS AND METHODS: We enrolled 12 patients (mean age: 51+/-11 years, 9 females) diagnosed as having thyrotoxicosis with heart failure and LVD {left ventricular ejection fraction (LVEF) <40%}, and divided them into two groups {Group I with RVD defined as tricuspid annular plane excursion (TAPSE) less than 15 mm and Group II without RVD}. Clinical features, laboratory variables, and echocardiographic parameters were compared between two groups. RESULTS: RVD was found in 6 (50%) patients. On admission, there were no significant differences between the two groups in clinical features, laboratory variables, or echocardiographic parameters including atrial fibrillation {6 vs. 5, not significant (NS)}, heart rate (149+/-38 vs. 148+/-32/min, NS), LVEF (36.7+/-9.5 vs. 35.1+/-6.3%, NS), or the tricuspid regurgitation peak pressure gradient (TRPPG, 30.9+/-2.0 vs. 36.3+/-9.3 mmHg, NS). After antithyroid treatment, all achieved an euthyroid state and both ventricular functions were recovered. All data, including the recovery time of LVEF and the change of heart rate between two groups, displayed no significant differences. CONCLUSION: In half of patients, RVD was combined with thyrotoxicosis-associated LVD. There were no differences in clinical factors or hemodynamic parameters between patients with and without RVD. This suggests that RVD is not secondary to thyrotoxicosis-associated LVD.
RESUMO
The metallurgy industry and municipal waste incinerators are considered the main sources of polychlorinated dibenzo-p-dioxin and dibenzofurans (PCDD/Fs) in many countries. This study investigated the emission factors and total emissions of PCDD/Fs and dioxin-like polychlorinated biphenyls (PCBs) emitted from metallurgy industries (including ferrous and nonferrous foundries) in Korea. The toxic equivalency (TEQ) emission factor of PCDD/Fs was the highest for secondary copper production, at 24451 ng I-TEQ/ton. The total estimated emissions of PCDD/Fs from these sources were 35.259 g I-TEQ/yr, comprising 0.088 g I-TEQ/yr from ferrous foundries, 31.713 g I-TEQ/yr from copper production, 1.716 g I-TEQ/yr from lead production, 0.111 g I-TEQ/yr from zinc production, and 1.631 g I-TEQ/yr from aluminum production. The total estimated annual amounts of dioxin-like PCBs emitted from these sources were 13.260 g WHO-TEQ/yr, comprising 0.014 g WHO-TEQ/yr from ferrous foundries, 12.675 g WHO-TEQ/yr from copper production, 0.170 g WHO-TEQ/yr from lead production, 0.017 g WHO-TEQ/yr from zinc production, and 0.384 g WHO-TEQ/yr from aluminum production. The highest emission factor was found for secondary copper smelting, at 9770 ng WHO-TEQ/ton.