Jimei University

About: Jimei University is a education organization based out in Amoy, China. It is known for research contribution in the topics: Computer science & Population. The organization has 4645 authors who have published 4293 publications receiving 42239 citations. The organization is also known as: Jíměi Dàxué.

Cloning and characterization of a new manganese superoxide dismutase from deep-sea thermophile Geobacillus sp. EPT3

Abstract: A new gene encoding a superoxide dismutase (SOD) was identified from a thermophile Geobacillus sp. EPT3 isolated from a deep-sea hydrothermal field in east Pacific. The open reading frame of this gene encoded 437 amino acid residues. It was cloned, overexpressed in Escherichia coli (DE3), and the recombinant protein was purified to homogeneity. Geobacillus sp. EPT3 SOD was of the manganese-containing SOD type, as judged by the insensitivity of the recombinant enzyme to both KCN and H2O2, and the activity analysis of Fe or Mn reconstituted SODs by polyacrylamide gel electrophoresis. The recombinant SOD was determined to be a homodimer with monomeric molecular mass of 59.0 kDa. In comparison with other Mn–SODs, the manganese-binding sites are conserved in the sequence (His260, His308, Asp392, His396). The recombinant enzyme had high thermostability at 50 °C. It retained 57 % residual activity after incubation at 90 °C for 1 h, which indicated that this SOD was thermostable. The enzyme also showed striking stability over a wide range of pH 5.0–11.0. At tested conditions, the recombinant SOD from Geobacillus sp. EPT3 showed a relatively good tolerance to some inhibitors, detergents, and denaturants, such as β-mercaptoethanol, dithiothreitol, phenylmethylsulfonyl fluoride, Chaps, Triton X-100, urea, and guanidine hydrochloride.

Multiperiodicity of Periodically Oscillated Discrete-Time Neural Networks With Transient Excitatory Self-Connections and Sigmoidal Nonlinearities

Abstract: The existing approaches to the multistability and multiperiodicity of neural networks rely on the strictly excitatory self-interactions of neurons or require constant interconnection weights. For periodically oscillated discrete-time neural networks (DTNNs), it is difficult to discuss multistable dynamics when the connection weights are periodically oscillated around zero. By using transient excitatory self-interactions of neurons and sigmoidal nonlinearities, we develop an approach to investigate multiperiodicity and attractivity of periodically oscillated DTNNs with time-varying and distributed delays. It shows that, under some new criteria, there exist multiplicity results of periodic solutions which are locally or globally exponentially stable. Computer numerical simulations are performed to illustrate the new theories.

Effect of heat-treated tea water-insoluble protein nanoparticles on the characteristics of Pickering emulsions

Abstract: Tea water-insoluble protein nanoparticles (TWIPNs) can be used as Pickering particles. However, Pickering emulsions stabilized by heat-treated TWIPNs (TWIPNPEs) were not characterized clearly. Therefore, the effect of heat-treated TWIPNs on the characteristics of Pickering emulsions was analyzed. TWIPNs became small at 60 °C and reassembled at 100 and 120 °C. Disulfide bonds and noncovalent bonds synergistically participated in the intermolecular forces of heat-treated TWIPNs. The random coil content of heat-treated TWIPNs decreased from 0.24 to 0.13 and the contents of α-helices and β-sheets increased from 0.11 to 0.27 to 0.19 and 0.30 in the proportion of secondary structure with the increase in heat-treated TWIPN temperature. High temperature (100 °C/120 °C) on TWIPN accelerated the flocculation of emulsion droplets. A potential mechanism for the changes occurring in TWIPNPEs based on heat-treated TWIPNs was proposed to exhibit the instability of TWIPNPEs stabilized by heat-treated TWIPNs due to the structural rearrangements and enhanced intermolecular forces of TWIPNs at 100 and 120 °C. Besides, heat-treated TWIPNs at 30 and 40 g/L decreased the gel-like behavior of TWIPNPEs. These results can broaden our understanding of the characteristics of TWIPNPEs stabilized by heat-treated TWIPNs for utilizing tea by-products.

On the Kirchhoff index of some toroidal lattices

Abstract: The resistance distance is a novel distance function on a graph proposed by Klein and Randic [D.J. Klein and M. Randic, Resistance distance, J. Math. Chem. 12 (1993), pp. 81–85]. The Kirchhoff index of a graph G is defined as the sum of resistance distances between all pairs of vertices of G. In this article, based on the result by Gutman and Mohar [I. Gutman and B. Mohar, The quasi-Wiener and the Kirchhoff indices coincide, J. Chem. Inf. Comput. Sci. 36 (1996), pp. 982–985], we compute the Kirchhoff index of the square, 8.8.4, hexagonal and triangular lattices, respectively.