Ultrafast Thermal Modification of Strong Coupling in an Organic Microcavity

There is growing interest in using strongly coupled organic microcavities to tune molecular dynamics, including the electronic and vibrational properties of molecules. However, very little attention has been paid to the utility of cavity polaritons as sensors for out-of-equilibrium phenomena, including thermal excitations. Here, we demonstrate that non-resonant infrared excitation of an organic microcavity system induces a transient response in the visible spectral range near the cavity polariton resonances. We show how these optical response can be understood in terms of ultrafast heating of electrons in the metal cavity mirror, which modifies the effective refractive index and subsequently the strong coupling conditions. The temporal dynamics of the microcavity are strictly determined by carriers in the metal, including the cooling of electrons via electron-phonon coupling and excitation of propagating coherent acoustic modes in the lattice. We rule out multiphoton excitation processes and verify that no real polariton population exists despite their strong transient features. These results suggest the promise of cavity polaritons as sensitive probes of non-equilibrium phenomena

Assembling a plug-and-play production line for combinatorial biosynthesis of aromatic polyketides in Escherichia coli

Polyketides are a class of specialised metabolites synthesised by both eukaryotes and prokaryotes. These chemically and structurally diverse molecules are heavily used in the clinic and include frontline antimicrobial and anticancer drugs such as erythromycin and doxorubicin. To replenish the clinicians’ diminishing arsenal of bioactive molecules, a promising strategy aims at transferring polyketide biosynthetic pathways from their native producers into the biotechnologically desirable host Escherichia coli. This approach has been successful for type I modular polyketide synthases (PKSs); however, despite more than 3 decades of research, the large and important group of type II PKSs has until now been elusive in E. coli. Here, we report on a versatile polyketide biosynthesis pipeline, based on identification of E. coli–compatible type II PKSs. We successfully express 5 ketosynthase (KS) and chain length factor (CLF) pairs—e.g., from Photorhabdus luminescens TT01, Streptomyces resistomycificus, Streptoccocus sp. GMD2S, Pseudoalteromonas luteoviolacea, and Ktedonobacter racemifer—as soluble heterodimeric recombinant proteins in E. coli for the first time. We define the anthraquinone minimal PKS components and utilise this biosynthetic system to synthesise anthraquinones, dianthrones, and benzoisochromanequinones (BIQs). Furthermore, we demonstrate the tolerance and promiscuity of the anthraquinone heterologous biosynthetic pathway in E. coli to act as genetically applicable plug-and-play scaffold, showing it to function successfully when combined with enzymes from phylogenetically distant species, endophytic fungi and plants, which resulted in 2 new-to-nature compounds, neomedicamycin and neochaetomycin. This work enables plug-and-play combinatorial biosynthesis of aromatic polyketides using bacterial type II PKSs in E. coli, providing full access to its many advantages in terms of easy and fast genetic manipulation, accessibility for high-throughput robotics, and convenient biotechnological scale-up. Using the synthetic and systems biology toolbox, this plug-and-play biosynthetic platform can serve as an engine for the production of new and diversified bioactive polyketides in an automated, rapid, and versatile fashion

Sirolimus for Kaposiform Hemangioendothelioma and Kasabach-Merritt Phenomenon in a Neonate

We present a case of a neonate born with kaposiform hemangioendothelioma (KHE), complicated by Kasabach-Merritt phenomenon (KMP) and other serious conditions, who was successfully treated with sirolimus. In addition to complications from thrombocytopenia and fluid overload, during the course of therapy, our patient experienced supratherapeutic drug levels at the commonly accepted starting dose of sirolimus. Patients with KHE and KMP should be closely monitored for potential complications of both the initial disease and unexpected side effects of treatments

Fabrication of Single-Crystalline InSb-on-Insulator by Rapid Melt Growth

InSb has the smallest bandgap and highest electron mobility among III-V semiconductors and is widely used for photodetectors and high-frequency electronic applications. Integration of InSb directly on Si would drastically reduce the fabrication cost and enable new applications, however, it is very challenging due to its 19% lattice mismatch with Si. Herein, the integration of single-crystalline InSb microstructures on insulator-covered Si through rapid melt growth (RMG) is reported and specifically provides details on the fabrication process. The importance of achieving high-quality conformal capping layers at low thermal budget to contain the InSb melt is assessed when the sample is annealed. The importance of ensuring a pristine Si seed area to achieve single-crystalline InSb is illustrated and demonstrated here for the first time