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Fenestration elements that enable spectrally selective dynamic modulation of the near-infrared region of the electromagnetic spectrum are of great interest as a means of decreasing the energy consumption of buildings by adjusting solar heat gain in response to external temperature. The binary vanadium oxide VO2 exhibits a near-room-temperature insulator–metal electronic transition accompanied by a dramatic modulation of the near-infrared transmittance. The low-temperature insulating phase is infrared transparent but blocks infrared transmission upon metallization. There is considerable interest in harnessing the thermochromic modulation afforded by VO2 in nanocomposite thin films. However, to prepare a viable thermochromic film, the visible-light transmittance must be maintained as high as possible while maximizing thermochromic modulation in the near-infrared region of the electromagnetic spectrum, which necessitates the development of high-crystalline-quality VO2 nanocrystals of the optimal particle siz...

The azinomycins are a family of potent anti-tumor agents with the ability to form interstrand crosslinks with DNA. This study reports on the unusual biosynthetic formation of the 5-methyl naphthoate moiety, which is essential for effective DNA association. While sequence analysis predicts that the polyketide synthase (AziB) catalyzes the formation of this naphthoate, 2-methylbenzoic acid, a truncated single-ring product, is formed instead. We demonstrate that the thioesterase (AziG) acts as a chain elongation and cyclization (CEC) domain and is required for the additional two rounds of chain extension to form the expected product.

We present a study of optical modulation by the effect of temperature-induced insulator-to-metal phase transition of vanadium dioxide ( V O 2 ) nanocrystals deposited in an antiresonance hollow-core fiber (AR-HCF). We fabricate such a V O 2 -coated fiber by embedding alkylsilane functionalized V O 2 nanocrystals into the air holes of an AR-HCF. With this fiber, we achieve an optical loss modulation of ∼ 60 % at a temperature above ∼ 53 ∘ C over an ultrabroad spectral range that encompasses the S + C + L band.