Abatement of thermal noise due to internal damping in 2D oscillators with rapidly rotating test masses.

Mechanical oscillators can be sensitive to very small forces. Low frequency effects are up-converted to higher frequency by rotating the oscillator. We show that for 2-dimensional oscillators rotating at frequency much higher than the signal the thermal noise force due to internal losses and competing with it is abated as the square root of the rotation frequency. We also show that rotation at frequency much higher than the natural one is possible if the oscillator has 2 degrees of freedom, and describe how this property applies also to torsion balances. In addition, in the 2D oscillator the signal is up-converted above resonance without being attenuated as in the 1D case, thus relaxing requirements on the read out. This work indicates that proof masses weakly coupled in 2D and rapidly rotating can play a major role in very small force physics experiments.

Gynecomastia and the complete circumareolar approach in the surgical management of skin redundancy.

Gynecomastia is a benign enlargement of the male breast due to a physiological or pathological factor that interferes with the balance between estrogens and androgens in the serum. Gynecomastia itself requires no treatment unless the persistent enlargement of the male breast is a source of embarrassment and/or distress for the adolescent or adult man. The indications for the surgical treatment of gynecomastia are founded on two main objectives: (1) the restoration of male chest shape and (2) diagnostic evaluation of suspected breast lesions. The diagnostic evaluation begins with an adequate history and a thorough breast examination helped by laboratory tests and instrumental research. Several approaches for surgical treatment have been described in the literature. Some problems arise in patients who have significant enlargement and ptosis of the breast that will require skin reduction and in some patients requiring nipple-areola complex reduction. The authors believe that the complete circumareolar technique with purse-string suture creates the best aesthetic results, with fewer complications, in patients with moderate and severe ptotic glandular breast enlargements that have skin redundancy combined with areolar enlargement. From 1995 through 1999, a total of 10 male patients with moderate to severe gynecomastia were treated surgically using a complete circumareolar approach. All patients achieved a good aesthetic contour of the chest. Only two patients required a revision of the circumareolar scar to correct postoperative enlargement.