Stretchable and Degradable Semiconducting Block Copolymers.

This paper describes the synthesis and characterization of a class of highly stretchable and degradable semiconducting polymers. These materials are multi-block copolymers (BCPs) in which the semiconducting blocks are based on the diketopyrrolopyrrole (DPP) unit flanked by furan rings and the insulating blocks are poly(ε-caprolactone) (PCL). The combination of stiff conjugated segments with flexible aliphatic polyesters produces materials that can be stretched >100%.

Effects of flexibility and branching of side chains on the mechanical properties of low-bandgap conjugated polymers.

This paper describes effects of the flexibility, length, and branching of side chains on the mechanical properties of low-bandgap semiconducting polymers. The backbones of the polymer chains comprise a diketopyrrolopyrrole (DPP) motif flanked by two furan rings and copolymerized by Stille polycondensation with thiophene (DPP2FT). The side chains of the DPP fall into three categories: linear alkyl (C8, C14, or C16), branched alkyl (ethylhexyl, EH, or hexyldecyl, HD), and linear oligo(ethylene oxide) (EO3, EO4, or EO5).

SERS-enhanced piezoplasmonic graphene composite for biological and structural strain mapping.

Thin-film optical strain sensors have the ability to map small deformations with spatial and temporal resolution and do not require electrical interrogation. This paper describes the use of graphene decorated with metallic nanoislands for sensing of tensile deformations of less than 0.04% with a resolution of less than 0.

Yield Point of Semiconducting Polymer Films on Stretchable Substrates Determined by Onset of Buckling.

Mechanical buckling of thin films on elastomeric substrates is often used to determine the mechanical properties of polymers whose scarcity precludes obtaining a stress-strain curve. Although the modulus and crack-onset strain can readily be obtained by such film-on-elastomer systems, information critical to the development of flexible, stretchable, and mechanically robust electronics (i.e.

Utility of 5-alpha-reductase inhibitors in active surveillance for favourable risk prostate cancer.

Introduction: This retrospective review compares prostate-specific antigen (PSA) doubling time (DT) prior to the initiation of a 5-alpha-reductase inhibitor (pre-5-ARI) to after the PSA nadir (post-nadir) has been reached for patients on active surveillance for favourable-risk prostate cancer.

Methods: Between 1996 and 2010, a total of 100 men with a history of 5-ARI use were captured from our active surveillance database. Twenty-nine patients had a sufficient number of PSA values to determine both pre-5-ARI and post-nadir DTs.