Electrocharging face masks with corona discharge treatment.

We detail an experimental method to electrocharge N95 facepiece respirators and face masks (FMs) made from a variety of fabrics (including non-woven polymer and knitted cloth) using corona discharge treatment (CDT). We present practical designs to construct a CDT system from commonly available parts and detail calibrations performed on different fabrics to study their electrocharging characteristics. After confirming the post-CDT structural integrity of fabrics, measurements showed that all non-woven polymer electret and only some knitted cloth fabrics are capable of charge retention. Whereas polymeric fabrics follow the well-known isothermal charging route, ion adsorption causes electrocharging in knitted cloth fabrics. Filtration tests demonstrate improved steady filtration efficiency in non-woven polymer electret filters. On the other hand, knitted cloth fabric filters capable of charge retention start with improved filtration efficiency which decays in time over up to 7 h depending on the fabric type, with filtration efficiency tracking the electric discharge. A rapid recharge for a few seconds ensures FM reuse over multiple cycles without degradation.

Treatment of nevus Ota: combined skin abrasion and carbon dioxide snow method.

Thirty-seven patients with nevus Ota were treated by skin abrasion-carbon dioxide snow therapy. Data obtained from 24 patients (including 5 infants) who completed treatment were analyzed to determine the number of treatment courses and to assess the outcome by color and histologic type. The 5 infants completing treatment received a mean of 10 courses of carbon dioxide snow therapy. Excluding these infants, the mean number of treatment courses was 3 for skin abrasion and 16 for carbon dioxide snow therapy. The therapeutic outcome was satisfactory, being graded as "excellent" in 6 patients, "excellent to good" in 6 patients, "good" in 10 Patients, and "fair" in 2 patients. None of the patients had a "poor" outcome. Darker lesions were generally less responsive to treatment. Lesions with melanocytes in the superficial dermis showed a better response with fewer courses of treatment. Those with melanocytes throughout the whole dermis generally had a poorer outcome. The results confirm that the benefits of this procedure are limited by the associated pain and the need for great skill and a long treatment duration.

The effect of Beraprost sodium on the survival of subcutaneous transferred jejunum after vascular pedicle interruption in a rat model.

Beraprost sodium, a stable PGI2 analog, having antiplatelet aggregation and vasodilating actions, was tested in a rat subcutaneous heterotopic jejunal model for its ability to improve survival after vascular pedicle interruption. Forth Sprague-Dawley rats were divided into four groups: Group 1 (control, ligation of pedicle on postoperative day 5); Group 2 (Beraprost sodium, ligation on day 5); Group 3 (control, ligation on day 7); and Group 4 (Beraprost sodium, ligation on day 7). The resulting viability rates were: Group 1 = 0 percent, Group 2 = 40 percent, Group 3 = 30 percent, Group 4 = 90 percent. These results indicate that the administration of Beraprost sodium facilitates the neovascularization of the transferred intestine and shortens the time required for viability of the transferred tissue, after interruption of the vascular pedicle.

Pectoralis major myocutaneous flaps in rats.

A new neurovascular, island, myocutaneous flap, including the pectoralis major, was created in a rat model. This model is useful for the observation of muscle degeneration and skin changes due to ischemia or denervation. Although this model requires a delay procedure, it allows the flap, that can be used as a free myocutaneous flap, to be raised reliably.