Wei Liu

Sichuan University, Hua-yang, Sichuan, China

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Publications (311)531.19 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Geraniol is a valuable acyclic monoterpene alcohol and has many applications in the perfume industries, pharmacy and others. It has been hypothesized that phosphatases can convert geranyl diphosphate (GPP) into geraniol. However, whether and which phosphatases can transform GPP to geraniol has remained unanswered up till now. In this paper, the catalysis abilities of four different types of phosphatases were studied with GPP as substrate in vitro. They are bifunctional diacylglycerol diphosphate phosphatase (DPP1) and lipid phosphate phosphatase (LPP1) from Saccharomyces cerevisiae, ADP-ribose pyrophosphatase (NudF) and alkaline phosphatase (PhoA) from Escherichia coli. The results show that just PhoA from E. coli can convert GPP into geraniol. Moreover, in order to confirm the ability of PhoA in vivo, the heterologous mevalonate pathway and geranyl diphosphate synthase gene from Abies grandis were co-overexpressed in E. coli with PhoA gene and 5.3±0.2 mg/l geraniol was produced from glucose in flask-culture. Finally, we also evaluated the fed-batch fermentation of this engineered E. coli and a maximum concentration of 99.3 mg/l geraniol was produced while the conversion efficiency of glucose to geranoid (gram to gram) was 0.51 %. Our results offer a new option for geraniol biosynthesis and promote the industrial bio-production of geraniol.
    06/2015; DOI:10.1080/21655979.2015.1062188
  • QJM: monthly journal of the Association of Physicians 06/2015; DOI:10.1093/qjmed/hcv107 · 2.46 Impact Factor
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    ABSTRACT: D-xylonate dehydratase YjhG from Escherichia coli can convert D-xylonate into 2-keto-3-deoxy- D-xylonate (KDX), and is a key enzyme in the biosynthesis of 1,2,4-butanetriol and other chemicals. However, the biochemical properties of YjhG still remain unknown. In this study, the activity assay method for YjhG was established based on semicarbazide method, in which KDX reacts with semicarbazide reagent, and is further quantified by high-resolution mass spectrometry. The effect of reaction conditions on YjhG activity was determined in vitro using purified His-tagged YjhG protein. This enzyme showed maximal activity at 30 °C and pH 8.0. Bivalent metal ions such as Mg(2+) and Mn(2+) activated, whereas Ni(2+) and Zn(2+) inhibited the activity of YjhG. Under optimal conditions, the Km and Vmax values were 4.88 mM and 78.62 μM l(-1)h(-1), respectively, when using D-xylonate as a substrate. Amino acids sequence alignments and catalytic properties analysis revealed that YjhG might be a member of IlvD/EDD family. Results obtained in this study may lay a foundation for further investigation on YjhG and will benefit its application in biosynthesis of related chemicals.
    06/2015; DOI:10.1080/21655979.2015.1040208
  • Molecular and Clinical Oncology 04/2015; DOI:10.3892/mco.2015.552
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    ABSTRACT: Surgery is currently the preferred treatment choice for mid-esophageal diverticula, while endoscopic therapy is rapidly establishing itself. We report the first two cases of giant mid-esophageal diverticula presented with dysphagia successfully treated with per-oral endoscopic myotomy (POEM). There were no complications during the procedure and the patients' conditions improved remarkably within short time of recovery. POEM could provide a safe, effective and less invasive treatment of mid-esophageal diverticula if appropriately used. Further studies on long-term efficacy with larger number of cases are necessary.
    Surgical Endoscopy 04/2015; DOI:10.1007/s00464-015-4181-2 · 3.31 Impact Factor
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    ABSTRACT: Myeloperoxidase is a key component of neutrophil granules involved in killing engulfed microorganisms. We obtained a zebrafish mutant (smu681) lacking Sudan black staining by large-scale screening, which was a neutrophil-replete but myeloperoxidase-deficient mutant. When infiltrated with Candida albicans, smu681 embryos and sibling embryos showed similar survival after infection. Proliferation of C. albicans was more rapid in smu681 embryos than in sibling embryos, although it was eventually suppressed. In addition, the number of neutrophils accumulating at the site of infection was significantly larger in mutant embryos than in sibling embryos, and mutant embryos showed increased expression of several inflammatory cytokines after C. albicans infection. These findings indicate that myeloperoxidase deficiency alters the inflammatory response to fungal infection. Copyright © 2015. Published by Elsevier Ltd.
    Fish &amp Shellfish Immunology 02/2015; 44(1). DOI:10.1016/j.fsi.2015.01.038 · 3.03 Impact Factor
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    ABSTRACT: Abstract Poly(3-hydroxypropionate) (P3HP) is a biodegradable and biocompatible thermoplastic. Previous studies demonstrated that engineered Escherichia coli strains can produce P3HP with supplementation of expensive vitamin B12. The present study examined the production of P3HP from glycerol in the recombinant Klebsiella pneumoniae strain, which naturally synthesizes vitamin B12. The genes glycerol dehydratase and its reactivation factor (dhaB123, gdrA and gdrB from K. pneumoniae), aldehyde dehydrogenase (aldH from E. coli) were cloned and expressed in K. pneumoniae to produce 3-hydroxypropionate (3HP), with two genes (dhaT and yqhD) for biosynthesis of 1,3-propanediol were deleted. To obtain P3HP production, propionyl-CoA synthetase (prpE from E. coli) and polyhydroxyalkanoate synthase (phaC from Ralstonia eutropha) were introduced. Under the appropriate aeration condition, the cell yield and P3HP content were 0.24 g/L and 12.7% (wt/wt [cell dry weight]) respectively along with 2.03 g/L 3HP after 48 h cultivation. Although the yield is relatively low, this study shows the feasibility of producing P3HP in K. pneumoniae from glycerol without vitamin B12 for the first time. The results also suggest that the aeration conditions should be optimized carefully for the efficient production of P3HP.
    01/2015; 6(2). DOI:10.1080/21655979.2015.1011027
  • Endoscopy 01/2015; 47 Suppl 1(S 01):E30-1. DOI:10.1055/s-0034-1391133 · 5.20 Impact Factor
  • Endoscopy 01/2015; 47(S 01):E85-E86. DOI:10.1055/s-0034-1391236 · 5.20 Impact Factor
  • IEEE Transactions on Magnetics 01/2015; DOI:10.1109/TMAG.2015.2434936 · 1.21 Impact Factor
  • Chinese Journal 01/2015; 60(7):645. DOI:10.1360/N972014-01183
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    ABSTRACT: As a typical biomineral, hydroxyapatite (HAp) is widely applied in bone implants and other related fields. However, the inherent nature of HAp can potentially be altered through restricting its fabrication conditions. Here, HAp fabricated by a hydrothermal treatment of pieces of natural seashell is demonstrated to have the capability of fluorescence quenching. To the best of the author's knowledge, this is the first time that this new property of HAp has been reported. Consequently, we assembled a fluorescence-quenching platform based on the biomineralized HAp substrate following a hydrothermal treatment and associated with a DNA molecular beacon and applied to cancer cell detection by the transformation from "OFF state" (fluorescence quenching) to "ON state" (fluorescence recovery). Herein, we found that the outer surface of HAp material after hydrothermal biomineralization for 5 days has considerable capability for both fluorescence quenching and recovery. These results may also have implications in the further detection of various targets such as cancer cells with other special surface antigens, significant biological small molecules or disease related microRNA, just by changing the sequence of the nucleic acid beacon according to the corresponding aptamer.
    Scientific Reports 12/2014; 4:7556. DOI:10.1038/srep07556 · 5.58 Impact Factor
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    ABSTRACT: Short chain diols (propanediols, butanediols, pentanediols) have been widely used in bulk and fine chemical industries as fuels, solvents, polymer monomers and pharmaceutical precursors. The chemical production of short chain diols from fossil resources has been developed and optimized for decades. Consideration of the exhausting fossil resources and the increasing environment issues, the bio-based process to produce short chain diols is attracting interests. Currently, a variety of biotechnologies have been developed for the microbial production of the short chain diols from renewable feed-stocks. In order to efficiently produce bio-diols, the techniques like metabolically engineering the production strains, optimization of the fermentation processes, and integration of a reasonable downstream recovery processes have been thoroughly investigated. In this review, we summarized the recent development in the whole process of bio-diols production including substrate, microorganism, metabolic pathway, fermentation process and downstream process.
    Microbial Cell Factories 12/2014; 13(1):165. DOI:10.1186/PREACCEPT-5297584212857603 · 4.25 Impact Factor
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    ABSTRACT: Multi-dimensional hydroxyapatite (HAp) nanoclusters are fabricated for the first time via a membrane assisted fabrication utilising a Nafion N-117 membrane. The effect of biomineralization time upon the resulting morphology is investigated in detail with the likely crystal growth mechanism proposed. This work opens up the new possibility for preparing HAp with other specific morphological alternatives and is of great value for applications in a plethora of fields.
    New Journal of Chemistry 11/2014; 39(1). DOI:10.1039/C4NJ01292E · 3.16 Impact Factor
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    ABSTRACT: Piezoelectric semiconductors, such as wurtzite structured ZnO, GaN, and InN, have novel properties owing to piezoelectric polarization tuned/controlled electronic transport characteristics. Under an externally applied strain, piezoelectric charges are created at an interface or junction, which are likely to tune and modulate the local band structure. Taking an Ag-ZnO-Ag two-terminal piezotronic transistor as an example, strain-dependent piezoelectric charge distributions and modulation of Schottky barrier heights (SBHs) at metal/semiconductor interfaces have been investigated by the first principle simulations. The width of piezocharge distribution is calculated by the density function theory and the Poisson equation. The modulations of SBHs at two interfaces show opposite trend under the applied strain. This study not only provides an understanding about the piezotronic effect from quantum theory point of view, but also a new method to calculate the key parameter for optimizing the design of piezotronic devices.
    Nano Energy 10/2014; 14. DOI:10.1016/j.nanoen.2014.10.014 · 10.21 Impact Factor
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    ABSTRACT: Urinary KIM-1 is an ideal biomarker for acute kidney injury diagnosis. The proof-of-concept is demonstrated by utilizing the hydroxyapatite derived from natural fish scales as an electrode material, where the sensing of KIM-1 is shown to be possible for the first time with a linear range from 0.01 to 0.20 μg mL(-1) and a detection limit of 0.017 μg mL(-1) under model conditions; proof-of-concept is demonstrated in spiked urine.
    The Analyst 09/2014; 139(21). DOI:10.1039/c4an00957f · 3.91 Impact Factor
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    ABSTRACT: The correlation between rheological behavior and time evolution of the phase separation patterns was investigated in the epoxy/thermoplastic blends. Before and during the induction period of phase separation, the storage and loss modulus initially increased with epoxy curing reaction and the concentration fluctuation. At the late stage of phase separation, the modulus values also increased and showed a sharp enhancement around the epoxy gel point. However, the time evolution during the reaction induced phase separation process differed a lot at various thermoplastic (TP) concentrations. At the low TP concentrations, the rheological parameters decreased with the coarsening of sea-island structure. At the high TP concentrations, the TP-rich continuous structures initially formed and maintained until the end, resulting in a continuous increase for the rheological characters. At middle TP concentrations, formation and evolution of the three-layered structure displayed a complicated rheological behavior. It was found that the storage modulus quickly increased, reached a vertex, then rapidly decreased, reached a minimum, and increased again afterwards. Although the rheological behaviors were almost phenomenologically similar as that in the normal dynamically symmetric system, driving force for the variation was fundamentally different. Especially for the case of middle TP concentrations, the behavior of the holistic volume shrinking of the slow dynamic TP-rich network and the flowing out of the fast dynamic epoxy-rich phase from the network during this period, as radically transformed the nature of the matrix from an elastic network to a macro-phase separated layer structure and caused the dramatic change of the rheological behaviors.
    Polymer 09/2014; 55(19). DOI:10.1016/j.polymer.2014.08.007 · 3.77 Impact Factor
  • Digestive Diseases and Sciences 06/2014; 59(12). DOI:10.1007/s10620-014-3232-1 · 2.55 Impact Factor
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    ABSTRACT: The morphology evolution and the corresponding linear viscoelastic behavior of the phase-separating polybutadiene (PB)/low vinyl content polyisoprene (LPI) blend have been investigated by phase contrast optical microscopy (PCOM), small-angle light scattering (SALS) and rheometry. Two kinds of structure evolutions and rheological responses have been observed. It is found that the co-continuous structure generally gives a power law behavior of the dynamic storage modulus versus frequency and the coarsening of co-continuous structure leads to a decrease of the storage modulus. For the droplet-matrix structure, a platform modulus is observed at the mediate frequencies, followed by the typical terminal relaxation behavior of storage modulus at the extremely low frequencies. The decreasing platform modulus and increasing terminal modulus with the growth of droplets are observed and can be well interpreted by the simplified Palierne model. The platform modulus and terminal modulus at a given frequency are found to be scalable with the phase separation time. Besides, the characteristic relaxation time and domain size of the droplets have been obtained by rheology. And it seems that the rheologically determined droplet dimensions are consistent with the ones determined by PCOM and SALS.
    Chinese Journal of Polymer Science 06/2014; 32(6):718-730. DOI:10.1007/s10118-014-1443-8 · 1.42 Impact Factor
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    ABSTRACT: To evaluate the safety and efficacy of endoscopic retrograde cholangiopancreatography (ERCP) in children with pancreaticobiliary diseases and the characteristics of pancreaticobiliary disorders in children.
    Zhonghua er ke za zhi. Chinese journal of pediatrics 05/2014; 52(5):328-32.

Publication Stats

3k Citations
531.19 Total Impact Points

Institutions

  • 2011–2015
    • Sichuan University
      • • Department of Gastroenterology and Hepatology
      • • Department of Orthopedic Surgery
      Hua-yang, Sichuan, China
    • Dalian University of Technology
      • School of Software
      Lü-ta-shih, Liaoning, China
    • Jiangsu Academy of Agricultural Sciences
      Nan-ching-hsü, Jiangxi Sheng, China
    • Hospital of the University of Pennsylvania
      • Department of Microbiology
      Filadelfia, Pennsylvania, United States
  • 2010–2015
    • Southern Medical University
      • Department of Cell Biology
      Shengcheng, Guangdong, China
    • University of California, Berkeley
      • Department of Mechanical Engineering
      Berkeley, California, United States
    • Nankai University
      • TEDA School of Biological Science and Biotechnology
      T’ien-ching-shih, Tianjin Shi, China
  • 2001–2015
    • Chinese Academy of Sciences
      • • Institute of Chemistry
      • • Qingdao Institute of Bioenergy and Bioprocess Technology
      • • State Key Laboratory of Environmental Chemistry and Ecotoxicology
      • • South China Botanical Garden
      • • Institute of Metal Research
      • • Institute of Biophysics
      Peping, Beijing, China
  • 2014
    • Technical Institute of Physics and Chemistry
      Peping, Beijing, China
  • 2002–2014
    • Huazhong University of Science and Technology
      • • National Engineering Research Center for Nanomedicine
      • • Department of Infectious Diseases
      • • Department of Electronics and Information Engineering
      Wu-han-shih, Hubei, China
  • 2012–2013
    • Huazhong Agricultural University
      • Division of Animal Infectious Disease
      Wu-han-shih, Hubei, China
  • 2011–2013
    • Jilin University
      • State Key Lab of Theoretical and Computational Chemistry
      Yung-chi, Jilin Sheng, China
  • 2010–2013
    • Nanyang Technological University
      • • School of Electrical and Electronic Engineering
      • • Luminous Center of Excellence for Semiconductor Lighting and Displays
      • • Centre for Multimedia and Network Technology (CeMNet)
      Tumasik, Singapore
  • 2007–2012
    • JiangHan University
      Jiang’an, Hubei, China
    • Tianjin University of Traditional Chinese Medicine
      T’ien-ching-shih, Tianjin Shi, China
  • 2010–2011
    • University of Shanghai for Science and Technology
      Shanghai, Shanghai Shi, China
  • 1991–2010
    • Albert Einstein College of Medicine
      • Department of Otorhinolaryngology - Head & Neck Surgery
      New York City, New York, United States
  • 2009
    • Nanjing University of Aeronautics & Astronautics
      Nan-ching, Jiangsu Sheng, China
    • Huazhong (Central China) Normal University
      Wu-han-shih, Hubei, China
  • 2008–2009
    • Hohai University
      Nan-ching, Jiangsu Sheng, China
    • Hubei University
      Wu-han-shih, Hubei, China
  • 2007–2008
    • Shandong University
      • School of Pharmaceutical Sciences
      Chi-nan-shih, Shandong Sheng, China
  • 2005
    • Hunan University
      • College of Chemistry and Chemical Engineering
      Ch’ang-sha-shih, Hunan, China
  • 1991–2001
    • Academia Sinica
      • Institute of Physics
      T’ai-pei, Taipei, Taiwan
  • 1998
    • Harvard University
      Cambridge, Massachusetts, United States