160 research outputs found

    Preparation of Nitrogen-Doped Carbon Materials from Monosodium Glutamate and Application in Reduction of p-Nitrophenol

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    Nitrogen-doped carbons (NCs) as supports for metal catalysts used in heterogeneous reactions are increasingly being investigated. In this work, NCs were prepared from monosodium glutamate (MSG) by direct carbonization, which were used as supporters to prepare Bi/NC catalysts. The Bi/NC catalysts were characterized by X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscope (TEM), and nitrogen adsorption isotherm. The results indicate that nitrogen was doped in the formation of pyridinic N, pyrrolic N, and graphitic N. The NCs possess high surface area (~652 m2/g) and uniform mesopore size (~2.11 nm). Bismuth nanoparticles (NPs) dispersed uniformly in NC with diameter of 10-20 nm. The catalytic performances were investigated using the reduction of 4-nitrophenol (4-NP) with excess potassium borohydride as a model reaction, the results indicating that the Bi/NC catalysts have higher activity and better reusability than the Bi/AC catalyst. Under the following conditions: 100 mL of 4-NP (2 mM), 0.03 g of 3%Bi/NC, n(KBH4) : n(4-NP) = 40:1, and at room temperature, the rate constant k can reach 0.31 min-1. 

    Preparation of Nitrogen-Doped Carbon Materials from Monosodium Glutamate and Application in Reduction of p-Nitrophenol

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    Nitrogen-doped carbons (NCs) as supports for metal catalysts used in heterogeneous reactions are increasingly being investigated. In this work, NCs were prepared from monosodium glutamate (MSG) by direct carbonization, which were used as supporters to prepare Bi/NC catalysts. The Bi/NC catalysts were characterized by X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscope (TEM), and nitrogen adsorption isotherm. The results indicate that nitrogen was doped in the formation of pyridinic N, pyrrolic N, and graphitic N. The NCs possess high surface area (~652 m2/g) and uniform mesopore size (~2.11 nm). Bismuth nanoparticles (NPs) dispersed uniformly in NC with diameter of 10-20 nm. The catalytic performances were investigated using the reduction of 4-nitrophenol (4-NP) with excess potassium borohydride as a model reaction, the results indicating that the Bi/NC catalysts have higher activity and better reusability than the Bi/AC catalyst. Under the following conditions: 100 mL of 4-NP (2 mM), 0.03 g of 3%Bi/NC, n(KBH4) : n(4-NP) = 40:1, and at room temperature, the rate constant k can reach 0.31 min-1. Copyright © 2018 BCREC Group. All rights reserved Received: 28th July 2017; Revised: 1st September 2017; Accepted: 7th September 2017; Available online: 22nd January 2018; Published regularly: 2nd April 2018 How to Cite: Cai, K.Y., Zhou, Y.M., Wang, P., Li, H., Li, Y., Tao, W. (2018). Preparation of Nitrogen-Doped Carbon Materials from Monosodium Glutamate and Application in Reduction of p-Nitrophenol. Bulletin of Chemical Reaction Engineering & Catalysis, 13 (1): 89-96 (doi:10.9767/bcrec.13.1.1428.89-96

    A new prognostic scale for the early prediction of ischemic stroke recovery mainly based on traditional Chinese medicine symptoms and NIHSS score: a retrospective cohort study

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    TCM symptoms & signs with appearance rate no less than 5 %. In practical analysis we selected 57 TCM symptoms with the appearance rate ≥5 % from 157 TCM symptoms& signs except tongue and pulse. (CSV 1 kb

    Imaging cell lineage with a synthetic digital recording system

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    Cell lineage plays a pivotal role in cell fate determination. Chow et al. demonstrate the use of an integrase-based synthetic barcode system called intMEMOIR, which uses the serine integrase Bxb1 to perform irreversible nucleotide edits. Inducible editing either deletes or inverts its target region, thus encoding information in three-state memory elements, or trits, and avoiding undesired recombination events. Using intMEMOIR combined with single-molecule fluorescence in situ hybridization, the authors were able to identify clonal structures as well as gene expression patterns in the fly brain, enabling both clonal analysis and expression profiling with intact spatial information. The ability to visualize cell lineage relationships directly within their native tissue context provides insights into development and disease

    Coumarins from the Herb Cnidium monnieri and Chemically Modified Derivatives as Antifoulants against Balanus albicostatus and Bugula neritina Larvae

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    In the search for new environmental friendly antifouling (AF) agents, four coumarins were isolated from the herbal plant Cnidium monnieri, known as osthole (1), imperatorin (2), isopimpinellin (3) and auraptenol (4). Furthermore, five coumarin derivatives, namely 8-epoxypentylcoumarin (5), meranzin hydrate (6), 2'-deoxymetranzin hydrate (7), 8-methylbutenalcoumarin (8), and micromarin-F (9) were synthesized from osthole. Compounds 1, 2, 4, 7 showed high inhibitory activities against larval settlement of Balanus albicostatus with EC50 values of 4.64, 3.39, 3.38, 4.67 mu g mL(-1). Compound 8 could significantly inhibit larval settlement of Bugula neritina with an EC50 value of 3.87 mu g mL(-1). The impact of functional groups on anti-larval settlement activities suggested that the groups on C-5' and C-2'/C-3' of isoamylene chian could affect the AF activities

    Imaging cell lineage with a synthetic digital recording system

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    Multicellular development depends on the differentiation of cells into specific fates with precise spatial organization. Lineage history plays a pivotal role in cell fate decisions, but is inaccessible in most contexts. Engineering cells to actively record lineage information in a format readable in situ would provide a spatially resolved view of lineage in diverse developmental processes. Here, we introduce a serine integrase-based recording system that allows in situ readout, and demonstrate its ability to reconstruct lineage relationships in cultured stem cells and flies. The system, termed intMEMOIR, employs an array of independent three-state genetic memory elements that can recombine stochastically and irreversibly, allowing up to 59,049 distinct digital states. intMEMOIR accurately reconstructed lineage trees in stem cells and enabled simultaneous analysis of single cell clonal history, spatial position, and gene expression in Drosophila brain sections. These results establish a foundation for microscopy-readable clonal analysis and recording in diverse systems

    Agromyces chromiiresistens sp. nov., Novosphingobium album sp. nov., Sphingobium arseniciresistens sp. nov., Sphingomonas pollutisoli sp. nov., and Salinibacterium metalliresistens sp. nov.: five new members of Microbacteriaceae and Sphingomonadaceae from polluted soil

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    There are many unidentified microbes in polluted soil needing to be explored and nominated to benefit the study of microbial ecology. In this study, a taxonomic research was carried out on five bacterial strains which were isolated and cultivated from polycyclic aromatic hydrocarbons, and heavy metals polluted soil of an abandoned coking plant. Phylogenetical analysis showed that they belonged to the phyla Proteobacteria and Actinobacteria, and their 16S rRNA gene sequence identities were lower than 98.5% to any known and validly nominated bacterial species, suggesting that they were potentially representing new species. Using polyphasic taxonomic approaches, the five strains were classified as new species of the families Microbacteriaceae and Sphingomonadaceae. Genome sizes of the five strains ranged from 3.07 to 6.60 Mb, with overall DNA G+C contents of 63.57–71.22 mol%. The five strains had average nucleotide identity of 72.38–87.38% and digital DNA-DNA hybridization of 14.0–34.2% comparing with their closely related type strains, which were all below the thresholds for species delineation, supporting these five strains as novel species. Based on the phylogenetic, phylogenomic, and phenotypic characterizations, the five novel species are proposed as Agromyces chromiiresistens (type strain H3Y2-19aT = CGMCC 1.61332T), Salinibacterium metalliresistens (type strain H3M29-4T = CGMCC 1.61335T), Novosphingobium album (type strain H3SJ31-1T = CGMCC 1.61329T), Sphingomonas pollutisoli (type strain H39-1-10T = CGMCC 1.61325T), and Sphingobium arseniciresistens (type strain H39-3-25T = CGMCC 1.61326T). Comparative genome analysis revealed that the species of the family Sphingomonadaceae represented by H39-1-10T, H39-3-25T, and H3SJ31-1T possessed more functional protein-coding genes for the degradation of aromatic pollutants than the species of the family Microbacteriaceae represented by H3Y2-19aT and H3M29-4T. Furthermore, their capacities of resisting heavy metals and metabolizing aromatic compounds were investigated. The results indicated that strains H3Y2-19aT and H39-3-25T were robustly resistant to chromate (VI) and/or arsenite (III). Strains H39-1-10T and H39-3-25T grew on aromatic compounds, including naphthalene, as carbon sources even in the presence of chromate (VI) and arsenite (III). These features reflected their adaptation to the polluted soil environment

    Pyrosequencing of Haliotis diversicolor Transcriptomes: Insights into Early Developmental Molluscan Gene Expression

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    National Natural Science Foundation of China [40976093]; National Basic Research Program of China (973) [2010CB126403]; Hi-Tech Research and Development (863) Program of China [2012AA10A412]Background: The abalone Haliotis diversicolor is a good model for study of the settlement and metamorphosis, which are widespread marine ecological phenomena. However, information on the global gene backgrounds and gene expression profiles for the early development of abalones is lacking. Methodology/Principal Findings: In this study, eight non-normalized and multiplex barcode-labeled transcriptomes were sequenced using a 454 GS system to cover the early developmental stages of the abalone H. diversicolor. The assembly generated 35,415 unigenes, of which 7,566 were assigned GO terms. A global gene expression profile containing 636 scaffolds/contigs was constructed and was proven reliable using qPCR evaluation. It indicated that there may be existing dramatic phase transitions. Bioprocesses were proposed, including the 'lock system' in mature eggs, the collagen shells of the trochophore larvae and the development of chambered extracellular matrix (ECM) structures within the earliest postlarvae. Conclusion: This study globally details the first 454 sequencing data for larval stages of H. diversicolor. A basic analysis of the larval transcriptomes and cluster of the gene expression profile indicates that each stage possesses a batch of specific genes that are indispensable during embryonic development, especially during the two-cell, trochophore and early postlarval stages. These data will provide a fundamental resource for future physiological works on abalones, revealing the mechanisms of settlement and metamorphosis at the molecular level

    Synthetic recording and in situ readout of lineage information in single cells

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    Reconstructing the lineage relationships and dynamic event histories of individual cells within their native spatial context is a long-standing challenge in biology. Many biological processes of interest occur in optically opaque or physically inaccessible contexts, necessitating approaches other than direct imaging. Here, we describe a new synthetic system that enables cells to record lineage information and event histories in the genome in a format that can be subsequently read out in single cells in situ. This system, termed Memory by Engineered Mutagenesis with Optical In situ Readout (MEMOIR), is based on a set of barcoded recording elements termed scratchpads. The state of a given scratchpad can be irreversibly altered by Cas9-based targeted mutagenesis, and read out in single cells through multiplexed single-molecule RNA fluorescence hybridization (smFISH). To demonstrate a proof of principle of MEMOIR, we engineered mouse embryonic stem (ES) cells to contain multiple scratchpads and other recording components. In these cells, scratchpads were altered in a progressive and stochastic fashion as cells proliferated. Analysis of the final states of scratchpads in single cells in situ enabled reconstruction of the lineage trees of cell colonies. Combining analysis of endogenous gene expression with lineage reconstruction in the same cells further allowed inference of the dynamic rates at which ES cells switch between two gene expression states. Finally, using simulations, we showed how parallel MEMOIR systems operating in the same cell can enable recording and readout of dynamic cellular event histories. MEMOIR thus provides a versatile platform for information recording and in situ, single cell readout across diverse biological systems

    The Impact of Yangtze River Discharge, Ocean Currents and Historical Events on the Biogeographic Pattern of Cellana toreuma along the China Coast

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    Aim: Genetic data were used to measure the phylogeographic distribution of the limpet, Cellana toreuma along the China coast in order to acsertain impacts of historic events, ocean currents and especially freshwater discharge from the Yangtze River on the connectivity of intertidal species with limited larval dispersal capability. Methodology/Principal Findings: Genetic variation in 15 populations of C. toreuma (n = 418), ranging from the Yellow Sea (YS), East China Sea (ECS) and South China Sea (SCS), were determined from partial mitochondrial cytochrome c oxidase subunit I gene. Genetic diversity and divergence based on haplotype frequencies were analyzed using CONTRIB, and AMOVA was used to examine genetic population structure. Historic demographic expansions were evaluated from both neutrality tests and mismatch distribution tests. Among the 30 haplotypes identified, a dominant haplotype No. 1 (H1) existed in all the populations, and a relatively abundant private haplotype (H2) in YS. Pairwise F-ST values between YS and the other two groups were relatively high and the percentage of variation among groups was 10.9%. Conclusions: The high nucleotide and gene diversity in the YS, with large pairwise genetic distances and relatively high percentages of variation among groups, suggests that this group was relatively isolated from ECS and SCS. This is likely driven by historic events, ocean currents, and demographic expansion. We propose that freshwater discharge from the Yangtze River, which may act as physical barrier limiting the southward dispersal of larvae from northern populations, is especially important in determining the separation of the YS group from the rest of the Chinese populations of C. toreuma.Natural Science Foundation for National Natural Science Foundation of China [41076083]; Distinguished Young Scholars of Fujian Province, China [2011J06017]; Fundamental Research Funds for the Central Universities [201012028
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