A highly enantioselective and practical synthesis of the HIV-1 reverse transcriptase inhibitor efavirenz (1) is described. The synthesis proceeds in 62% overall yield in seven steps from 4-chloroaniline (6) to give efavirenz (1) in excellent chemical and optical purity. A novel, enantioselective addition of Li-cyclopropyl acetylide (4a) to p-methoxybenzyl-protected ketoaniline 3a mediated by (1R,2S)-N-pyrrolidinylnorephedrine lithium alkoxide (5a) establishes the stereogenic center in the target with a remarkable level of stereocontrol.
A biomimetic substrate for cell‐culture is fabricated by plasma treatment of a prestressed thermoplastic shrink film to create tunable multiscaled alignment “wrinkles”. Using this substrate, the functional alignment of human embryonic stem cell derived cardiomyocytes is demonstrated.
Nowadays, charge separation and efficient solar-light absorption are the main challenges in the photoreduction of CO 2 . Although significant efforts have been made to overcome these issues, including the use of cocatalysts and doping, photocatalysts still suffer from low photocatalytic activity and stability. Herein, the localized surface plasmonic resonance (LSPR) effect of Au nanoparticles deposited into the zeolitic imidazolate framework (ZIF-67) was investigated for the photoreduction of CO 2 . Different Au loadings in ZIF were prepared and their effects were studied on photocatalytic performance. Plasmonic Au nanoparticles (PNPs) in the size range of 30−40 nm improved visible-light absorption, enhanced charge separation, and played an important role in selectivity. A volcano relationship of plasmonic Au NPs with methanol and ethanol generation was found, along with the deposition of plasmonic Au nanoparticles. A total yield of 2.5 mmol g −1 h −1 of methanol and 0.5 mmol g −1 h −1 of ethanol were obtained, which are the highest values compared to those reported in other studies. Finally, our results revealed that Au PNPs have a significant impact on the selectivity and photocatalytic activity of ZIF-67 for the photoreduction of CO 2 and could be a promising alternative toward designing plasmonic reticular materials.
The potential of rapid, quantitative, and sensitive diagnosis has led to many innovative ‘lab on chip’ technologies for point of care diagnostic applications. Because these chips must be designed within strict cost constraints to be widely deployable, recent research in this area has produced extremely novel non-conventional micro- and nano-fabrication innovations. These advances can be leveraged for other biological assays as well, including for custom assay development and academic prototyping. The technologies reviewed here leverage extremely low-cost substrates and easily adoptable ways to pattern both structural and biological materials at high resolution in unprecedented ways. These new approaches offer the promise of more rapid prototyping with less investment in capital equipment as well as greater flexibility in design. Though still in their infancy, these technologies hold potential to improve upon the resolution, sensitivity, flexibility, and cost-savings over more traditional approaches.
Polyolefins are finding increased popularity in microfluidic applications due to their attractive mechanical, processing, and optical properties. While intricate features are typically realized in these thermoplastics by hot embossing and injection molding, such fabrication approaches are expensive and slow. Here, we apply our shrink-induced approach-first demonstrated with polystyrene 'Shrinky-Dink' sheets-to create micro- and nanostructures with cross-linked polyolefin thin films. These multi-layered films shrink by 95% and with greater uniformity than the Shrinky-Dinks. With such significant reduction in size, along with attractive material properties, such commodity films could find important applications in low cost microfluidic prototyping as well as in point-of-care diagnostics. In this technical note, we demonstrate the ability to rapidly and easily create unique microstructures, increase microarray feature density, and even induce self-assembled integrated metallic nanostructures with these shrink wrap films.
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