[Luo, Kun; Xiao, Peigen; Li, Ying; Song, Jingyuan; Pang, Xiaohui; Yao, Hui; Han, Jianping; Liu, Chang; Chen, Shilin] Chinese Acad Med Sci, Peking Union Med Coll, Inst Med Plant Dev, Beijing 100037, Peoples R China.;[Luo, Kun] Hubei Univ Chinese Med, Coll Pharm, Wuhan, Hubei, Peoples R China.;[Zhu, Yingjie] SW Jiaotong Univ, Sch Biosci & Engn, Chengdu, Sichuan, Peoples R China.;[Xu, Hongxi] Hong Kong Jockey Club Inst Chinese Med, Chinese Med Lab, Hong Kong, Hong Kong, Peoples R China.
[Yao, Hui] Chinese Acad Med Sci, Peking Union Med Coll, Inst Med Plant Dev, Beijing 100037, Peoples R China.
BACKGROUND: The internal transcribed spacer 2 (ITS2) region of nuclear ribosomal DNA is regarded as one of the candidate DNA barcodes because it possesses a number of valuable characteristics, such as the availability of conserved regions for designing universal primers, the ease of its amplification, and sufficient variability to distinguish even closely related species. However, a general analysis of its ability to discriminate species in a comprehensive sample set is lacking. METHODOLOGY/PRINCIPAL FINDINGS: In the current study, 50,790 plant and 12,221 animal ITS2 sequences downloaded from GenBank were evaluated according to sequence length, GC content, intra- and inter-specific divergence, and efficiency of identification. The results show that the inter-specific divergence of congeneric species in plants and animals was greater than its corresponding intra-specific variations. The success rates for using the ITS2 region to identify dicotyledons, monocotyledons, gymnosperms, ferns, mosses, and animals were 76.1%, 74.2%, 67.1%, 88.1%, 77.4%, and 91.7% at the species level, respectively. The ITS2 region unveiled a different ability to identify closely related species within different families and genera. The secondary structure of the ITS2 region could provide useful information for species identification and could be considered as a molecular morphological characteristic. CONCLUSIONS/SIGNIFICANCE: As one of the most popular phylogenetic markers for eukaryota, we propose that the ITS2 locus should be used as a universal DNA barcode for identifying plant species and as a complementary locus for CO1 to identify animal species. We have also developed a web application to facilitate ITS2-based cross-kingdom species identification (http://its2-plantidit.dnsalias.org).
The present communication reports the topotactic conversion of NiCo2O4 nanowires array on carbon cloth (NiCo2O4 NA/CC) into NiCo2S4 NA/CC, which is used as an efficient bifunctional electrocatalyst for water splitting with good durability and superior activity in 1.0 M KOH. This NiCo2S4 NA/CC electrode produces 100 mA cm(-2) at an overpotential of 305 mV for hydrogen evolution and 100 mA cm(-2) at an overpotential of 340 mV for oxygen evolution. To afford a 10 mA cm(-2) water-splitting current, the alkaline water electrolyzer made from NiCo2S4 NA/CC needs a cell voltage of 1.68 V, which is 300 mV less than that for NiCo2O4 NA/CC, and has good stability.
Development of efficient noble metal-free bifunctional electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is an ongoing challenge. Herein, we report the development of nickel promoted cobalt disulfide nanowire array supported on carbon cloth (Ni-23%-CoS2/CC) as an efficient bifunctional electrocatalyst for water splitting with superior activity and good durability in basic media. This Ni-2.3%-CoS2/CC electrode delivers 100 mA cm(-2) at overpotential of 231 mV for HER and 100 mA cm(-2) at overpotential of 370 mV for OER. The water electrolyzer based on Ni-2.3%-CoS2/CC only requires a cell voltage of 1.66 V to afford 10 mA cm(-2), implying the great potential for water splitting applications. (C) 2015 Published by Elsevier B.V.
It is highly attractive to develop non-noble-metal nanoarray architecture as a high-active catalyst electrode for molecular detection due to its large specific surface area and easy accessibility to target molecules. In this paper, we demonstrate the development of cobalt nitride nanowire array on Ti mesh(Co3N NW/TM) as an efficient catalyst electrode for glucose oxidation in alkaline solutions and H2O2 reduction in neutral solutions. Electrochemical tests suggest that such Co3N NW/TM possesses superior non-enzymatic sensing ability toward rapid glucose and H2O2 detection. As a glucose sensor, this fabricated electrode offers a high sensitivity of 3325.6 mu A mM(-1)cm(- 2), with a wide linear range from 0.1 mu M to 2.5 mM, a low detection limit of 50 nM (S/N = 3), and satisfactory stability and reproducibility. Its application in determining glucose in human blood serum is also successful. Amperometric H2O2 sensing canalso been realized with a sensitivity of 139.9 mu A mM(-1)cm(-2), a linear range from 2 mu M to 28 mM, and adetection limit of 1 mu M (S/N = 3). This nanoarray architecture holds great promise as an attractive sensing platform toward electrochemical small molecules detection. (C) 2017 Published by Elsevier B.V.