The present invention concerns the use of methods and compositions for the isolation of small RNA molecules, such as microRNA and siRNA molecules. In another aspect, an embodiment provides a clock loss sense circuit and method that utilizes counters and reset signals to compare a primary clock and secondary clock signal. A pivot arm defines a contact surface for the inner side of the wheel rim hub mount pad, and when the tire is rotated by an operator with the inner side in contact with the contact surface, an anti-rotate pin carried on the pivot arm may be adjusted in radial position relative to the drive axis to accommodate different lug holes at varying lug bolt circle diameters. The second planetary gear train similarly includes a power input as well as a second sun gear, a second carrier connected to a final drive, and a second ring gear. The results of this work can be used in scaling up the production of droplets and in the simultaneous production of droplets and particles with different dimensions.