Primary focal hyperhidrosis is a disorder of idiopathic excessive sweating that typically affects the axillae, palms, soles, and face. The disorder, which affects up to 2.8% of the US population, is associated with considerable physical, psychosocial, and occupational impairments. Current therapeutic strategies include topical aluminum salts, tap-water iontophoresis, oral anticholinergic agents, local surgical approaches, and sympathectomies. These treatments, however, have been limited by a relatively high incidence of adverse effects and complications. Non-surgical treatment complications are typically transient, whereas those of surgical therapies may be permanent and significant. Recently, considerable evidence suggests that botulinum toxin type A (BTX-A) injections into hyperhidrotic areas can considerably reduce focal sweating in multiple areas without major adverse effects. BTX-A has therefore shown promise as a potential replacement for more invasive treatments after topical aluminum salts have failed. This article reviews the epidemiology, diagnosis, and management of primary focal hyperhidrosis, with an emphasis on recent research evidence supporting the use of BTX-A injections for this indication.

Para-hydrogen-induced polarization (PHIP) is a technique capable of producing spin polarization at a magnitude far greater than state-of-the-art magnets. A significant application of PHIP is to generate contrast agents for biomedical imaging. Clinically viable and effective contrast agents not only require high levels of polarization but heterogeneous catalysts that can be used in water to eliminate the toxicity impact. Herein, we demonstrate the use of Pt nanoparticles capped with glutathione to induce heterogeneous PHIP in water. The ligand-inhibited surface diffusion on the nanoparticles resulted in a (1) H polarization of P=0.25% for hydroxyethyl propionate, a known contrast agent for magnetic resonance angiography. Transferring the (1) H polarization to a (13) C nucleus using a para-hydrogen polarizer yielded a polarization of 0.013%. The nuclear-spin polarizations achieved in these experiments are the first reported to date involving heterogeneous reactions in water.

Platinum nanoparticles capped with cysteine ligands were synthesized and utilized to create the highest polarization reported to date for heterogeneous PHIP in water.