An Intrinsically Micro-/Nanostructured Pollen Substrate with Tunable Optical Properties for Optoelectronic Applications.

There is broad interest in developing photonically active substrates from naturally abundant, minimally processed materials that can help to overcome the environmental challenges of synthetic plastic substrates while also gaining inspiration from biological design principles. To date, most efforts have focused on rationally engineering the micro- and nanoscale structural properties of cellulose-based materials by tuning fibril and fiber dimensions and packing along with chemical modifications, while there is largely untapped potential to design photonically active substrates from other classes of natural materials with distinct morphological features. Herein, the fabrication of a flexible pollen-derived substrate is reported, which exhibits high transparency (>92%) and high haze (>84%) on account of the micro- and nanostructure properties of constituent pollen particles that are readily obtained from nature and require minimal extraction or processing to form the paper-like substrate based on colloidal self-assembly. Experiments and simulations confirm that the optical properties of the pollen substrate are tunable and arise from light-matter interactions with the spiky surface of pollen particles. In a proof-of-concept example, the pollen substrate is incorporated into a functional perovskite solar cell while the tunable optical properties of the intrinsically micro-/nanostructured pollen substrate can be useful for a wide range of optoelectronic applications.

Three Cases of Cutaneous Warts Treated With Moxibustion.

Moxibustion is a treatment that uses thermal stimulation generated when herbal materials are burned, indirectly or directly, on the affected area or acupoint. Three cases are presented to report the efficacy of direct moxibustion on cutaneous warts. Three patients with chronic cutaneous warts received direct moxibustion made of Artemisia argyi (Dongbang Inc., Chungnam, Korea). Moxa burning was performed using moxa cones. Approximately 80% of a cone was burned, until patients reported feeling a burning sensation, at which time the cone was removed and another one burned. As part of this approach, patients underwent 5-19 moxibustion procedures during and after wart removal. After warts were completely eliminated, moxa burning was performed on each patient until approximately 60% of a cone was burned or the patient felt heat sensitization but no pain. In these cases, moxibustion seemed to have an effect on cutaneous warts. A possible mechanism is that direct moxibustion likely induces tissue damage from burning and, subsequently, a wound healing effect at a different temperature level. Our reports suggest that it would be worthwhile to conduct further studies on the safety and efficacy of moxibustion on warts or to develop a medical device that uses modified moxibustion.