Effects of Strain on Electronic Properties of Graphene

We present first-principles calculations of electronic properties of graphene under uniaxial and isotropic strains, respectively. The semi-metallic nature is shown to persist up to a very large uniaxial strain of 30% except a very narrow strain range where a tiny energy gap opens. As the uniaxial strain increases along a certain direction, the Fermi velocity parallel to it decreases quickly and vanishes eventually, whereas the Fermi velocity perpendicular to it increases by as much as 25%. Thus, the low energy properties with small uniaxial strains can be described by the generalized Weyl's equation while massless and massive electrons coexist with large ones. The work function is also predicted to increase substantially as both the uniaxial and isotropic strain increases. Hence, the homogeneous strain in graphene can be regarded as the effective electronic scalar potential.Comment: 4 pages, 6 figures; Published versio

EST sequencing and gene expression profiling in Scutellaria baicalensis

Scutellaria baicalensis is an important medicinal plant, but few genomic resources are available for this species, as well as for other non-model plants. One of the major new directions in genome research is to discover the full spectrum of genes transcribed from the whole genome. Here, we report extensive transcriptome data of the early growth stage of S. baicalensis. This transcriptome consensus sequence was constructed by de novo assembly of shotgun sequencing data, obtained using multiple next-generation DNA sequencing (NGS) platforms (Roche/454 GS_FLX+ and Illumina/Solexa HiSeq2000). We show that this new approach to obtain extensive mRNA is an efficient strategy for genome-wide transcriptome analysis. We obtained 1,226,938 and 161,417,646 reads using the GS_FLX and the Illumina/Solexa HiS-eq2000, respectively. De novo assembly of the high-quality GS_FLX and Illumina reads (95 % and 75 %) resulted in more than 82 Mb of mRNA consensus sequence, which we assembled into 51,188 contigs, with at least 500 bp per contig. Of these contigs, 39,581 contained known genes, as determined by BLASTX searches against non-redundant NCBI database. Of these, 20,498 different genes were expressed during the early growth stage of S. baicalensis. We have made the expressed sequences available on a public database. Our results demonstrate the utility of combining NGS technologies as a basis for the development of genomic tools in non-model, medicinal plant species. Knowledge of all described genes and quantitation of the expressed genes, including the transcription factors involved, will be useful in studies of the biology of S. baicalensis gene regulation