Piezoelectric microcantilevers (MCs) have extensive applications in microelectromechanical systems. One of the applications of piezoelectric MCs is in self-sensing sensors. These sensors are highly popular due to their high accuracy, quick response, and environmental compatibility. Since the output current of piezoelectric layer is used as the sensing parameter in piezoelectric MCs, sensor optimization requires the maximum output current for each specific vibration. This paper uses dynamic piezoelectric MC analysis in different operating environments (air and liquid) to determine the factors influencing the output current of a piezoelectric layer. To obtain the differential equation of vibration, the hydrodynamic force applied to the piezoelectric MC by using the sphere string model. The equation was obtained via the Euler-Bernoulli beam theory and the Lagrange equation. The differential equation of the movement would yield both the MC deformation and the piezoelectric layer current. Using the Sobol statistical method for sensitivity analysis, the effect of each geometric parameter of the piezoelectric MC on the output current was studied to find the optimal geometry for the maximum output current. Results show that the output power of the piezoelectric layer is reduced in a liquid environment. Moreover, increasing the density of the liquid further exacerbates the drop in the output power. Therefore, in cases where the MC is to be used in a liquid environment (such as in biosensors), it is best to use a low-density liquid. The results also show that the electric current produced in the piezoelectric layer increases by reducing the length of the MC.

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Objective: Uterine myoma is the most common benign tumor however with significant distress and reduced quality of life in affected women. Besides, vitamin D deficiency may be a risk factor for uterine myoma. This study aimed to evaluate the effect of vitamin D supplements on the size of myoma in women with vitamin D insufficiency or deficiency. Materials and methods: This clinical trial was conducted in a teaching hospital from 2019 to 2020. According to baseline vitamin D level, participants were assigned into two interventional equal groups (vitamin D deficiency or insufficiency) to receive either 1000 IU daily or 50000 IU weekly vitamin D for 12 weeks. The size and location of the uterine myoma were compared before and after the intervention. Results: Totally, 137 women with uterine myoma were enrolled. Based on baseline vitamin D level, 52 cases had vitamin D insufficiency and 85 cases had vitamin D deficiency. No significant difference was observed in age and BMI in both groups. The location of the subserosal and intramural myoma did not differ, otherwise, the percent of the submucosal myomas were increased significantly (p=0.020) after the intervention. In both groups decreased myoma size otherwise not significant was seen after the intervention (p=0.148 and p=0.664 respectively). Conclusion: Vitamin D supplementation may not be effective in women with vitamin D insufficiency or deficiency in the short term to reduce myoma size.