Before the introduction of ultrasonography (US), ovarian cysts in newborns were thought to be rare. With the extended use of real-time US, prenatal detection has increased. There is still considerable controversy regarding the best treatment of these neonatal findings. A total of 27 instances in 24 consecutive newborns of antenatally-diagnosed ovarian cysts were reviewed for US data, management, and outcome to assess the ante- and postnatal evolution of the cyst and establish appropriate therapy. The cysts detected during pregnancy were studied by repeated postnatal US studies. In 10 children (2 with bilateral cysts) the cyst evolved spontaneously toward regression. Fourteen patients were operated upon; 10 had complex and 4 (in 1 bilateral) had simple cysts. Cystectomy was employed when possible to preserve the ovarian parenchyma (3 cases); in the remaining cases oophorectomy was performed. Histologically, the cysts were of follicular origin or necrosis made a diagnosis impossible. US was found to be a helpful diagnostic tool for simple ovarian cysts, but could not reliably distinguish between benign and malignant tumors if a sonographically complex lesion was present. Based on our experience, surgical management of ovarian cysts should be reserved to complex masses. Simple cysts can be monitored safely by close US follow-up; surgery is indicated if the cyst fails to regress after several months or becomes symptomatic.

The purpose of this paper is to propose a useful method to implement active magnetic bearings (AMBs) on an existing\ud rotating shaft which rotates on conventional bearings. This is feasible if AMBs can produce the same reaction loads of\ud conventional ones and if the size of vane is large enough to host an AMB. As this substitution could offer some difficulties\ud due to the different size between magnetic bearings and conventional ones, a set of equations are performed to show\ud that a variation of some parameters can solve this problem. The journal ratio is the geometrical parameter introduced to\ud develop the present analysis. The variation of journal ratio does not produce a variation of the pole’s surface so that the\ud reaction load does not change. The results are analyzed by numerical analysis by mathematical relationships involving the\ud design parameters, magneto-static simulations and dynamic simulation on shaft when it is tested by disturbance rejection\ud and reference tracking input in order to analyze the differences on dynamic behavior of the shaft on its suspended\ud sections. Results show that the displacement pattern of the suspended sections remains unchanged, confirming that the\ud reaction load, produced by pole expansion, remains the same varying the journal ratio