Simple Approach to Superhydrophobic Nanostructured Al for Practical Antifrosting Application Based on Enhanced Self-propelled Jumping Droplets

Frost formation can cause operational difficulty and efficiency loss for many facilities such as aircraft, wind turbines, and outdoor heat exchangers. Self-propelled jumping by condensate droplets on superhydrophobic surfaces delays frost formation, so many attempts have been made to exploit this phenomenon. However, practical application of this phenomenon is currently unfeasible because many processes to fabricate the superhydrophobic surfaces are inefficient and because self-propelled jumping is difficult to be achieved in a humid and low-temperature environment because superhydrophobicity is degraded in these conditions. Here, we achieved significantly effective anti-icing superhydrophobic aluminum. Its extremely low adhesive properties allow self-propelled jumping under highly supersaturated conditions of high humidity or low surface temperature. As a result, this surface helps retard frost formation at that condition. The aluminum was made superhydrophobic by a simple and cost-effective process that is adaptable to any shape. Therefore, it has promise for use in practical and industrial applications

Biosynthesis of (−)-5-Hydroxy-equol and 5‑Hydroxy-dehydroequol from Soy Isoflavone, Genistein Using Microbial Whole Cell Bioconversion

Equols are isoflavandiols formed by reduction of soy isoflavones such as daidzein and genistein by gut microorganisms. These phytoestrogens are of interest for their various biological effects. We report biosynthesis from genistein to (−)-5-hydroxy-equol in recombinant <i>E. coli</i> expressing three reductases (daidzein reductase DZNR, dihidrodaidzein reductase DHDR, tetrahydrodaidzein reductase THDR) and a racemase (dihydrodaidzein racemase, DDRC) originating from the gut bacterium, <i>Slackia isoflavoniconvertens</i>. The biosynthesized 5-hydroxy-equol proved as an optically negative enantiomer, nonetheless it displayed an inverse circular dichroism spectrum to (<i>S</i>)-equol. Compartmentalized expression of DZNR and DDRC in one <i>E. coli</i> strain and DHDR and THDR in another increased the yield to 230 mg/L and the productivity to 38 mg/L/h. If the last reductase was missing, the intermediate spontaneously dehydrated to 5-hydroxy-dehydroequol in up to 99 mg/L yield. This novel isoflavene, previously not known to be synthesized in nature, was also detected in this biotransformation system. Although (<i>S</i>)-equol favors binding to human estrogen receptor (hER) β over hERα, (−)-5-hydroxy-equol showed the opposite preference. This study provides elucidation of the biosynthetic route of (−)-5-hydroxy-equol and measurement of its potent antagonistic character as a phytoestrogen for the first time

Cooperative Catechol-Functionalized Polypept(o)ide Brushes and Ag Nanoparticles for Combination of Protein Resistance and Antimicrobial Activity on Metal Oxide Surfaces

Prevention of biofouling and microbial contamination of implanted biomedical devices is essential to maintain their functionality and biocompatibility. For this purpose, polypept­(o)­ide block copolymers have been developed, in which a protein-resistant polysarcosine (pSar) block is combined with a dopamine-modified poly­(glutamic acid) block for surface coating and silver nanoparticles (Ag NPs) formation. In the development of a novel, versatile, and biocompatible antibacterial surface coating, block lengths pSar were varied to derive structure–property relationships. Notably, the catechol moiety performs two important tasks in parallel; primarily it acts as an efficient anchoring group to metal oxide surfaces, while it furthermore induces the formation of Ag NPs. Attributing to the dual function of catechol moieties, antifouling pSar brush and antimicrobial Ag NPs can not only adhere stably on metal oxide surfaces, but also display passive antifouling and active antimicrobial activity, showing good biocompatibility simultaneously. The developed strategy seems to provide a promising platform for functional modification of biomaterials surface to preserve their performance while reducing the risk of bacterial infections