Browsing by Author "Li, Yan"

Now showing 1 - 4 of 4
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    Carbon Nanotubes and Related Nanomaterials: Critical Advances and Challenges for Synthesis toward Mainstream Commercial Applications
    (American Chemical Society, 2018) Rao, Rahul; Pint, Cary L.; Islam, Ahmad E.; Weatherup, Robert S.; Hofmann, Stephan; Meshot, Eric R.; Wu, Fanqi; Zhou, Chongwu; Dee, Nicholas; Amama, Placidus B.; Carpena-Nuñez, Jennifer; Shi, Wenbo; Plata, Desiree L.; Penev, Evgeni S.; Yakobson, Boris I.; Balbuena, Perla B.; Bichara, Christophe; Futaba, Don N.; Noda, Suguru; Shin, Homin; Kim, Keun Su; Simard, Benoit; Mirri, Francesca; Pasquali, Matteo; Fornasiero, Francesco; Kauppinen, Esko I.; Arnold, Michael; Cola, Baratunde A.; Nikolaev, Pavel; Arepalli, Sivaram; Cheng, Hui-Ming; Zakharov, Dmitri N.; Stach, Eric A.; Zhang, Jin; Wei, Fei; Terrones, Mauricio; Geohegan, David B.; Maruyama, Benji; Maruyama, Shigeo; Li, Yan; Adams, W. Wade; Hart, A. John
    Advances in the synthesis and scalable manufacturing of single-walled carbon nanotubes (SWCNTs) remain critical to realizing many important commercial applications. Here we review recent breakthroughs in the synthesis of SWCNTs and highlight key ongoing research areas and challenges. A few key applications that capitalize on the properties of SWCNTs are also reviewed with respect to the recent synthesis breakthroughs and ways in which synthesis science can enable advances in these applications. While the primary focus of this review is on the science framework of SWCNT growth, we draw connections to mechanisms underlying the synthesis of other 1D and 2D materials such as boron nitride nanotubes and graphene.
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    Identification of Novel Short BaTiO3-Binding/Nucleating Peptides for Phage-Templated in Situ Synthesis of BaTiO3 Polycrystalline Nanowires at Room Temperature
    (American Chemical Society, 2016) Li, Yan; Cao, Binrui; Yang, Mingying; Zhu, Ye; Suh, Junghae; Mao, Chuanbin
    Ferroelectric materials, such as tetragonal barium titanate (BaTiO3), have been widely used in a variety of areas including bioimaging, biosensing, and high power switching devices. However, conventional methods for the synthesis of tetragonal phase BaTiO3 usually require toxic organic reagents and high temperature treatments, and are thus not environment-friendly and energy-efficient. Here, we took advantage of the phage display technique to develop a novel strategy for the synthesis of BaTiO3 nanowires. We identified a short BaTiO3-binding/nucleating peptide, CRGATPMSC (named RS), from a phage-displayed random peptide library by biopanning technique and then genetically fused the peptide to the major coat protein (pVIII) of filamentous M13 phages to form the pVIII-RS phages. We found that the resultant phages could not only bind with the presynthesized BaTiO3 crystals but also induce the nucleation of uniform tetragonal BaTiO3 nanocrystals at room temperature and without the use of toxic reagents to form one-dimensional polycrystalline BaTiO3 nanowires. This approach enables the green synthesis of BaTiO3 polycrystalline nanowires with potential applications in bioimaging and biosensing fields.
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    Investigations of the biosynthesis of sparsomycin
    (1992) Li, Yan; Parry, Ronald J.
    The biosynthesis of the antitumor antibiotic, sparsomycin, produced by Streptomyces sparsogenes, has been investigated. Incorporation studies employing ($\sp{13}$C)-labeled precursors have shown that both L- and D-isomers of S-(methylthio)methyl-cysteine are specifically incorporated into the antibiotic. Furthermore, both L- and D-isomers of S-(methylthio)methylcysteinol are proved to be the advanced intermediates lying beyond S-(methylthio)methylcysteine. S-Methylcysteine is found not to be incorporated intact into the antibiotic; however, an isotopic trapping experiment and preliminary cell-free studies indicate that S-methylcysteine is still quite likely to be an intermediate on the pathway. A very high isotope effect was observed during studies of the loss of hydrogen atoms from the methyl group of S-methylcysteine. The uracil moiety (6) of sparsomycin is found to be derived from the indole fragment of tryptophan. N-Formylanthranilic acid was originally proposed as an intermediate lying beyond tryptophan on the pathway to 6. However, precursor incorporation studies have shown that N-formylanthranilic acid is incorporated by deformylation to anthranilic acid, which is then converted back to tryptophan before incorporation into sparsomycin. Therefore, the originally proposed pathway has to be revised. The final steps in the biosynthesis of uracil moiety are shown to be similar to the biosynthesis of xanthosine monophosphate (XMP).
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    Single molecule sequencing of the M13 virus genome without amplification
    (Public Library of Science, 2017) Zhao, Luyang; Deng, Liwei; Li, Gailing; Jin, Huan; Cai, Jinsen; Shang, Huan; Li, Yan; Wu, Haomin; Xu, Weibin; Zeng, Lidong; Zhang, Renli; Zhao, Huan; Wu, Ping; Zhou, Zhiliang; Zheng, Jiao; Ezanno, Pierre; Yang, Andrew X.; Yan, Qin; Deem, Michael W.; He, Jiankui
    Next generation sequencing (NGS) has revolutionized life sciences research. However, GC bias and costly, time-intensive library preparation make NGS an ill fit for increasing sequencing demands in the clinic. A new class of third-generation sequencing platforms has arrived to meet this need, capable of directly measuring DNA and RNA sequences at the single-molecule level without amplification. Here, we use the new GenoCare single-molecule sequencing platform from Direct Genomics to sequence the genome of the M13 virus. Our platform detects single-molecule fluorescence by total internal reflection microscopy, with sequencing-by-synthesis chemistry. We sequenced the genome of M13 to a depth of 316x, with 100% coverage. We determined a consensus sequence accuracy of 100%. In contrast to GC bias inherent to NGS results, we demonstrated that our single-molecule sequencing method yields minimal GC bias.