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Cui J.D.,Hebei University of Science and Technology | Cui J.D.,CAS Institute of Process Engineering | Cui J.D.,Tianjin University of Science and Technology | Qiu J.Q.,Hebei University of Science and Technology | And 3 more authors.
Critical Reviews in Biotechnology | Year: 2014

Phenylalanine ammonia lyase (PAL) catalyzes the nonoxidative deamination of l-phenylalanine to form trans-cinnamic acid and a free ammonium ion. It plays a major role in the catabolism of l-phenylalanine. The presence of PAL has been reported in diverse plants, some fungi, Streptomyces and few Cyanobacteria. In the past two decades, PAL has gained considerable significance in several clinical, industrial and biotechnological applications. Since its discovery, much knowledge has been gathered with reference to the enzyme's importance in phenyl propanoid pathway of plants. In contrast, there is little knowledge about microbial PAL. Furthermore, the commercial source of the enzyme has been mainly obtained from the fungi. This study focuses on the recent advances on the physiological role of microbial PAL and the improvements of PAL biotechnological production both from our laboratory and many others as well as the latest advances on the new applications of microbial PAL. © 2014 Informa Healthcare USA, Inc. All rights reserved. Source

Liu C.,Zaozhuang University | Zhou L.,Zaozhuang University | Ma L.,Guang Xi University | Lin R.,Zhejiang University
Journal of Solution Chemistry | Year: 2013

The densities of l-alanine and l-serine in aqueous solutions of N,N-dimethylformamide (DMF) have been measured at 298.15 K with an Anton Paar Model 55 densimeter. Apparent molar volumes (Vφ), standard partial molar volumes (V0 φ), standard partial molar volumes of transfer (Δtr V0 φ) and hydration numbers have been determined for the amino acids. The Δtr V0 φ values of l-serine are positive which suggest that hydrophilic-hydrophilic interactions between l-serine and DMF are predominant. The -CH3 group of l-alanine has much more influence on the volumetric properties and the Δtr V0 φ have smaller negative values. The results have been interpreted in terms of the cosphere overlap model. © 2013 Springer Science+Business Media New York. Source

Zhang Y.-D.,Guilin University of Technology | Zhang S.-H.,Guilin University of Technology | Ge C.-M.,Guilin University of Technology | Wang Y.-G.,Guilin University of Technology | And 2 more authors.
Synthesis and Reactivity in Inorganic, Metal-Organic and Nano-Metal Chemistry | Year: 2013

At the same condition, utilizing the different of base, the authors constructed two wholly different compounds, 1 and 2. Compounds 1 and 2 are one-dimensional (1D) chainlike, while the coordination mode of dicyandiamide is different in both complexes. In 1, the dicyandiamide is μ 1,5-dca bridged coordination mode; in 2, that is μ 1,3-dca bridged coordination mode. Two new heterobinuclear nickel and sodium polymers [NiN a(L)(dca)]n (1) and [NiNa(L)(dca)]2n ·(CH 3COOCH3)n ·(H2O)n, (2) [where H2L = N,N′-bis(3-ethoxy-salicylidene) ethylenediamine, dca = N(CN)2 -], were synthesized and characterized by elemental analysis and X-ray crystal diffraction. The heterobinuclear complex 1, C22H22N5NaNiO 4, crystallizes in the monoclinic system space group P 21/c, with a = 8.0955 (7) Å, b = 22.1988 (18) Å, c = 12.9314 (11) Å; β = 103.4700(10)°; Z = 4; S = 1.01; V = 2260.0(3) Å3; DCalcd = 1.476 gcm-3; F(000) = 1040; μ = 0.92 mm-1; R1 = 0.041; wR2 = 0.104. The complex 2, C23.50H27N5NaNiO5.50, the crystals belong to the monoclinic system, space group C2/c, with a = 31.553 (8) Å, b = 12.836 (3) Å, c = 13.264 (3) Å; β = 111.234 (4)°; Z = 8; S = 0.95; V = 5007.6 (19)Å3; DCalcd = 1.457 gcm-3; F(000) = 2288; μ = 0.84 mm-1; R 1 = 0.072; wR2 = 0.211. Complexes 1 and 2 are both axisymmetric heterobinuclear nickel complexes. The geometry around nickel atoms can be described as a slightly distorted plane geometry, and sodium atoms that as a slightly distorted octahedral geometry. Complexes 1 and 2 are both one-dimensional (1D) chainlike supramolecular structure bridged by dicyandiamide to form the polymer. The coordination mode of dicyandiamide is different in both complexes. In 1, the dicyandiamide is μ1,5-dca bridged coordination mode; in 2, that is μ1,3-dca bridged coordination mode by dicyandiamide. Supplemental materials are available for this article. Go to the publisher's online edition of Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistry to view the supplemental file. © 2013 Taylor and Francis Group, LLC. Source

Wang W.,China Institute of Atomic Energy | Guan Y.,Guang Xi University | He M.,China Institute of Atomic Energy | Jiang S.,China Institute of Atomic Energy | And 2 more authors.
Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms | Year: 2010

79Se is a long-lived fission product with chemical and radiological toxicity. It is one of the radionuclides of interest in nuclear waste disposal due to its potential migration capacity to the surface environment. Furthermore, 79Se is an ideal tracer in biomedicine. One of the major obstacles in the measurement of ultratrace 79Se with AMS is the strong interference from the isobaric nuclide 79Br. This paper presents a new ultra-sensitive method for 79Se measurements with AMS. The novel aspects of our procedures include the extraction of SeO2 - molecular ions, that results in a suppression of 79Br background by as much as about five orders of magnitude; the selection of Ag2SeO3 as the chemical form of Se in the target sample, that brings about a relatively large and stable SeO2 - beam current; and the renovation of the multi-anode detector, that makes 79Se better identified from the interfering nuclide 79Br. By using these procedures, a sensitivity of better than 1.0 × 10-12 has been achieved for 79Se/Se measurement with the CIAE-AMS system. It is then possible to quantify the tracer 79Se in biological samples. Recently, we are prepared to develop the 79Se-AMS biological tracer methodology. © 2009 Elsevier B.V. All rights reserved. Source

Zhang Y.,Sun Yat Sen University | Zhang Y.,Guang Xi University | He C.,Sun Yat Sen University | Sharma V.K.,Florida Institute of Technology | And 3 more authors.
Separation and Purification Technology | Year: 2011

Membrane filtration was coupled with heterogeneous Fenton-like catalytic oxidation to resolve the continuously reuse problem of fine catalysts. A new integrated (MHF) reactor was developed to allow the active species to remain in the reaction system. The reactor consisted of a newly prepared heterogeneous catalyst, superfine Fe-immobilized carbon (FeOOH-C) particles, and a submerged ceramic micro-filtration membrane separator. Experimental results showed that the membrane module could efficiently intercept FeOOH-C particles in the reactor by the synergistic cooperative sieving of the raw and dynamic membranes. A relatively steady flux was maintained, but the magnitude of the flux was affected by the concentration of the FeOOH-C. In the MHF reactor, degradation of the targeted pollutant, acid orange II (AO II), occurred continuously and efficiently without an additional separation process to recover FeOOH-C. At a FeOOH-C dose of 1 g L-1 and a residence time of 120 min, the MHF reactor could keep a constant flux of 3 L m-2 min-1 with a stable degradation efficiency of ∼98% for 100 mg L-1 AO II solution. The integrated process of membrane separation and heterogeneous Fenton-like catalytic oxidation was confirmed to be an efficient process for degradation of recalcitrant organic pollutants in wastewater. © 2011 Elsevier B.V. All rights reserved. Source

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