A thalidomide-binding aptamer was produced by systematic evolution of ligands by exponential enrichment from a library of non-natural DNA in which thymidine had been replaced with a modified deoxyuridine bearing a cationic functional group via a hydrophobic methylene linker at the C5 position. The additional functional group in the modified DNA aptamer could improve stability against nucleases and increase the binding affinity to thalidomide. The selected aptamer could recognize thalidomide enantioselectively, although a racemic thalidomide-attached gel was used for the selection. Surface plasmon resonance and fluorescence titration studies revealed that the selected modified DNA aptamer and a truncated version bound with an (R)-thalidomide derivative with high enantioselectivity, but not with the (S)-form. The modified group in the DNA aptamer is indispensable for the interaction with thalidomide, as the corresponding natural type DNA bearing the same base sequence showed no binding affinity with (R)- nor (S)-thalidomide. Computational sequence analysis suggested that the selected apatamer (108 mer) could fold into a three-way junction structure; however, truncation of this aptamer (31 mer) revealed that the thalidomide-binding site is a hairpin-bulge region that is a component of one of the arms of the three-way junction structure. The Kd value of the truncated 31 mer aptamer for binding with the (R)-thalidomide derivative was 1.0 microM estimated from fluorescence titration study. The aptamer that can recognize a single enantiomer of thalidomide will be useful as a biochemical tool for the analysis and study of the biological action of thalidomide enantiomers.

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Thermal conductivities of silicone matrix polymers including fillers of diamond particles and/or hexagonal boron nitride (h-BN) platelets were systematically investigated in an attempt to find a thermal interface material (TIM) having high isotropic thermal conductivity and high electrical insulating ability to enable efficient heat dissipation from the motor coil ends of electric vehicles. The TIM with mixed fillers of diamond particles and h-BN platelets had a maximum thermal conductivity of 6.1 W m−1 K−1 that was almost isotropic. This is the highest value among the thermal conductivities of TIMs with silicone matrix polymer reported to date. The mechanism behind the thermal conductivity of the TIMs was also examined from the viewpoint of the change in the number of thermally conductive networks and/or a decrease in the thermal resistivity of junctions of neighboring diamond particles through the incorporation of h-BN platelets. The TIMs developed in this study will make it possible to manage the heat of electric motors and will help to popularize electric vehicles.

Installation of a carbanionic substituent, that is strongly stabilized by two (trifluoromethyl)sulfonyl (Tf = SO 2 CF 3) groups, into several fluorescence dyes including boron-dipyrromethenes (BODIPYs), fluoresceins, and aminocoumarins has been achieved by the 2,2-bis(triflyl)ethylation reaction of the dye frameworks with highly electrophilic Tf 2 C = CH 2 , followed by neutralization with NaHCO 3. Despite the contradiction between water solubility and lipophilicity, the carbanion-decorated dyes thus obtained showed significant enhancement of not only water solubility but also lipophilicity. This work clearly demonstrates that the fluorinated, highly stabilized carbanionic substituent is a new option for controlling the macroscopic property of chemical materials. Water solubility (and aqueous solubility) is a key macroscopic property for chemical materials directed towards biorelevant applications. [1] The most common way to improve the water solubility of less soluble compounds is introduction of ionic groups such as the sulfonato group into the molecular structure (Figure 1 A). However, such ionic functionalities

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