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We report a copper-catalyzed enantioselective hydroboration of α,β-unsaturated aldehydes with pinacolborane. α,β-Unsaturated aldehydes were converted to the corresponding γ-pinacolboronate alcohols in good yields and enantioselectivities through consecutive hydroboration of the C═O and C═C bonds. This process provides simple access to the hydroborated product of allylic alcohols, and the resulting γ-pinacolboronate alcohols could be utilized in various transformations.

We report an efficient and highly enantioselective hydroboration of aliphatic 1,1-disubstituted alkenes with pinacolborane using a phosphine-Cu catalyst. The method allows facile preparation of enantiomerically enriched β-chiral alkyl pinacolboronates from a range of 1,1-disubstituted alkenes with high enantioselectivity up to 99% ee. Unprecedented enantiodiscrimination between the geminal alkyl substituents was observed with functional group compatibility in the hydroboration. Furthermore, a catalyst loading as low as 1 mol % furnished the desired product without a decrease in yield or selectivity, demonstrating its efficiency in gram scale synthesis.

A carbon nanotube yarn core graphitic shell hybrid fiber was fabricated via facile heat treatment of epoxy-based negative photoresist (SU-8) on carbon nanotube yarn. The effective encapsulation of carbon nanotube yarn in carbon fiber and a glassy carbon outer shell determines their physical properties. The higher electrical conductivity (than carbon fiber) of the carbon nanotube yarn overcomes the drawbacks of carbon fiber/glassy carbon, and the better properties (than carbon nanotubes) of the carbon fiber/glassy carbon make up for the lower thermal and mechanical properties of the carbon nanotube yarn via synergistic hybridization without any chemical doping and additional processes.

Although the work function of graphene under a given metal electrode is critical information for the realization of high-performance graphene-based electronic devices, relatively little relevant research has been carried out to date. In this work, the work function values of graphene under various metals are accurately measured for the first time through a detailed analysis of the capacitance-voltage (C-V) characteristics of a metal-graphene-oxide-semiconductor (MGOS) capacitor structure. In contrast to the high work function of exposed graphene of 4.89-5.16 eV, the work function of graphene under a metal electrode varies depending on the metal species. With a Cr/Au or Ni contact, the work function of graphene is pinned to that of the contacted metal, whereas with a Pd or Au contact the work function assumes a value of ∼4.62 eV regardless of the work function of the contact metal. A study of the gate voltage dependence on the contact resistance shows that the latter case provides lower contact resistance.

We demonstrate that the use of a monolayer graphene as a gate electrode on top of a high-κ gate dielectric eliminates mechanical-stress-induced-gate dielectric degradation, resulting in a quantum leap of gate dielectric reliability. The high work function of hole-doped graphene also helps reduce the quantum mechanical tunneling current from the gate electrode. This concept is applied to nonvolatile Flash memory devices, whose performance is critically affected by the quality of the gate dielectric. Charge-trap flash (CTF) memory with a graphene gate electrode shows superior data retention and program/erase performance that current CTF devices cannot achieve. The findings of this study can lead to new applications of graphene, not only for Flash memory devices but also for other high-performance and mass-producible electronic devices based on MOS structure which is the mainstream of the electronic device industry.

Medicinal soy yogurt (sogurt) containing high levels of gamma-aminobutyric acid (GABA), free amino acids (FAAs), statins, and isoflavone aglycones was developed using lactic acid bacteria (1:1 mixture of Lactobacillus delbrueckii subsp. latis KFRI 01181 and Lactobacillus plantarum KFRI 00144) and Monascus-fermented soybean extract (MFSE, 1.5%, w/v). Changes in the content of some functional components (GABA, FAAs, statins, isoflavones) and physical (pH, titratable acidity, water-holding capacity), biological (viable cell counts), and sensory characteristics of sogurts during fermentation and cold storage were examined. The medicinal sogurt contained significantly (p < 0.05) high levels of FAAs (2011.2 +/- 8.1 mg/100 g of dry weight of sogurt), GABA (45.5 +/- 1.9 mg), statins (100.1 +/- 7.5 microg), and isoflavone aglycones (56.4 +/- 4.6 mg) compared with the control sogurt (1167.1 +/- 8.1 mg, 32.1 +/- 2.5 mg, not detected, and 19.2 +/- 1.9 mg, respectively) after fermentation for 24 h at 35 degrees C. During cold storage for 30 days at 4 degrees C, medicinal sogurt displayed higher water-holding capacity and titratable acidity and total bacterial cells and lower pH than the control sogurt (p < 0.05). Overall sensory acceptability of medicinal sogurt supplemented with MFSE was higher than that of the control sogurt prepared without MFSE. The results indicate that the addition of the appropriate MFSE concentrations (1.5%, w/v) improved the physicochemical properties as well as sensory characteristics of soy yogurt, resulting in enhanced health-benefit ingredients and consumers' preferences.