Browsing by Author "Zhang, Xian"

Now showing 1 - 3 of 3
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    KAS-III free FA synthesis
    (2020-12-01) San, Ka-yiu; Zhang, Xian; Wu, Hui; Wang, Dan; Rice University; United States Patent and Trademark Office
    The present disclosure describes a genetically engineered a KASIII-independent fatty acid biosynthetic pathway that makes use of the promiscuous nature of the rest of the FAS enzymes (3-ketoacyl-ACP synthetase, 3-ketoacyl-ACP reductase, 3-hydroxyacyl ACP dehydrase, enoyl-ACP reductase) to bypass the KASIII step by providing a Co-A precursor of two or higher than two carbons (such as the four carbon butyryl-CoA) as the starting molecule. Since many CoA-based starter molecules can be supplied for the fatty acid synthesis, much more diversified products can be obtained with various carbon-chain lengths. As such, this disclosure will serve as a powerful and efficient platform to produce low to medium chain length products carrying many different functional groups.
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    Microbial production of fats
    (2021-02-16) San, Ka-yiu; Li, Zhilin; Zhang, Xian; Rice University; United States Patent and Trademark Office
    This invention describes a method of using microbial to produce fats, such as fatty acids and their derivatives, or products derived from the fatty acid synthesis cycle, such as hydroxyfatty acids, methyl ketones, and the like.
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    Tunable Lattice Coupling of Multipole Plasmon Modes and Near-Field Enhancement in Closely Spaced Gold Nanorod Arrays
    (Nature Publishing Group, 2016) Huang, Yu; Zhang, Xian; Ringe, Emilie; Hou, Mengjing; Ma, Lingwei; Zhang, Zhengjun
    Considering the nanogap and lattice effects, there is an attractive structure in plasmonics: closely spaced metallic nanoarrays. In this work, we demonstrate experimentally and theoretically the lattice coupling of multipole plasmon modes for closely spaced gold nanorod arrays, offering a new insight into the higher order cavity modes coupled with each other in the lattice. The resonances can be greatly tuned by changes in inter-rod gaps and nanorod heights while the influence of the nanorod diameter is relatively insignificant. Experimentally, pronounced suppressions of the reflectance are observed. Meanwhile, the near-field enhancement can be further enhanced, as demonstrated through surface enhanced Raman scattering (SERS). We then confirm the correlation between the near-field and far-field plasmonic responses, which is significantly important for maximizing the near-field enhancement at a specific excitation wavelength. This lattice coupling of multipole plasmon modes is of broad interest not only for SERS but also for other plasmonic applications, such as subwavelength imaging or metamaterials.