Active modulation of the polarization states of terahertz light is indispensable for polarization-sensitive spectroscopy, having important applications such as non-contact Hall measurements, vibrational circular dichroism measurements and anisotropy imaging. In the terahertz region, the lack of a polarization modulator similar to a photoelastic modulator in the visible range hampers expansion of such spectroscopy. A terahertz chiral metamaterial has a huge optical activity unavailable in nature; nevertheless, its modulation is still challenging. Here we demonstrate a handedness-switchable chiral metamaterial for polarization modulation employing vertically deformable Micro Electro Mechanical Systems. Vertical deformation of a planar spiral by a pneumatic force creates a three-dimensional spiral. Enantiomeric switching is realized by selecting the deformation direction, where the polarity of the optical activity is altered while maintaining the spectral shape. A polarization rotation as high as 28° is experimentally observed, thus providing a practical and compact polarization modulator for the terahertz range.

Psoriasis is a chronic inflammatory and immune‐mediated disease associated with several comorbidities, such as obesity, hypertension, diabetes mellitus, dyslipidemia and cardiovascular disorder. These comorbidities are components of metabolic syndrome. The pathogenesis of metabolic syndrome is supposed to be related to increased levels of adipocytokines, such as tumor necrosis factor‐α (TNF‐α) and adiponectin. Recent study has revealed a high prevalence of metabolic syndrome in psoriatics compared with other skin diseases. Biologic agents, including anti‐TNF‐α antibodies, are recommended as the first‐line treatment for psoriatics with metabolic syndrome. This article reviews the association of psoriasis and metabolic syndrome in terms of adipocytokines and evaluates the role of biologic agents in the treatment of psoriasis.