Well-aligned nanotip arrays were fabricated by electron cyclotron resonance (ECR) plasma process using gas mixtures of silane, methane, argon, and hydrogen. The resultant tips have nanoscale apexes (∼1 nm) with high aspect ratios (∼50), which were achieved by simultaneous SiC nanomask formation and dry etching during ECR plasma process. This technique was applied to a variety of substrates such as silicon, polycrystalline silicon, gallium nitride, gallium phosphide, sapphire, and aluminum, indicating its general applicability. High-resolution transmission electron microscopy and Auger depth profile analyses revealed that the SiC cap, with Si:C ratio of 1:1, exhibited 3C−SiC and 2H−SiC structure on Si and GaP, respectively, with heteroepitaxial relationship. This one-step self-masked dry etching technique enables the fabrication of uniform nanotip arrays on various substrates over large area at low process temperatures, thereby demonstrating a high potential for practical industrial application.

Top-gate thin film transistors with n-type ZnO active channel were performed under 230°C. Especially, ZnO film was deposited by a combined method of sol-gel and chemical bath deposition without any preactivation for film growth. Silicon nitride and indium tin oxide were used as the gate insulator and the conducting electrodes ͑source, drain, and gate͒. These transistors were highly transparent in the visible spectrum, with transmittance as high as 75% to approximately 85% at wavelength from 500 to 700 nm. The optimum device has field-effect mobility of 0.67 cm 2 / V s and an on-off ratio more than 10 7 .

Fifteen tanshinone analogues isolated from the chloroform extract of Danshen roots (Salviae Miltiorrhizae Radix) by chromatographic procedures were tested for their cytotoxic activities against KB, Hela, Colo-205 and Hep-2 carcinoma cell lines. Several of them were effective at concentrations below 1 micrograms/ml concentrations. Tanshinone analogues with either hydroxy substitutions or olefinic feature in ring A demonstrated higher biologic activities. Analysis of structure-activity relationship indicate that the basic requirement for activity is the presence of a furano-o-naphthoquinone in the molecule. Compounds which lack an intact furan ring were found to be inactive. It is suggested that the planar phenanthrene ring of the tanshinones may be essential for interaction with DNA molecule whereas the furano-o-quinone moiety could be responsible for the production of reactive free radicals in the close vicinity of the bases to cause DNA damage.

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