Objectives The aim of this study was to investigate factors affecting ablative efficiency of high intensity focused ultrasound (HIFU) for adenomyosis. Materials and methods In all, 245 patients with adenomyosis who underwent ultrasound guided HIFU (USgHIFU) were retrospectively reviewed. All patients underwent dynamic contrast-enhanced magnetic resonance imaging (MRI) before and after HIFU treatment. The non-perfused volume (NPV) ratio, energy efficiency factor (EEF) and greyscale change were set as dependent variables, while the factors possibly affecting ablation efficiency were set as independent variables. These variables were used to build multiple regression models. Results A total of 245 patients with adenomyosis successfully completed HIFU treatment. Enhancement type on T1 weighted image (WI), abdominal wall thickness, volume of adenomyotic lesion, the number of hyperintense points, location of the uterus, and location of adenomyosis all had a linear relationship with the NPV ratio. Distance from skin to the adenomyotic lesion's ventral side, enhancement type on T1WI, volume of adenomyotic lesion, abdominal wall thickness, and signal intensity on T2WI all had a linear relationship with EEF. Location of the uterus and abdominal wall thickness also both had a linear relationship with greyscale change. Conclusion The enhancement type on T1WI, signal intensity on T2WI, volume of adenomyosis, location of the uterus and adenomyosis, number of hyperintense points, abdominal wall thickness, and distance from the skin to the adenomyotic lesion's ventral side can all be used as predictors of HIFU for adenomyosis.

Surface charge densities of spherical silica nanoparticles of varied size spanning from 4.1 to 495.7 nm in NaCl solution with a concentration from 0.003 to 1.2 mM at a pH value of 8.0 were determined by converting their corresponding measured zeta potential with Poisson–Boltzmann model. The magnitude of the derived surface charge density (negative) at a given NaCl concentration of 0.225 mM decreases monotonically with the increasing particle size and reaches almost a steady value when the size exceeds 30 nm, revealing clearly the effect of the nanoparticle curvature on the surface charge density. The experimental data provide a consensus for the validity of different models describing the relation between the surface charge density and the electric potential, that is, the surface complexation model and the Poisson–Boltzmann model for the charged nanospheres in electrolyte solution. We found that if the former includes the curvature-dependent deprotonation constant of the surface silanol groups, both models would give a consistent result.

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