Isolation and phylogenetic analysis of hemagglutinin gene of H9N2 influenza viruses from chickens in South China from 2012 to 2013.

As part of our ongoing influenza surveillance program in South China, 19 field strains of H9N2 subtype avian influenza viruses (AIVs) were isolated from dead or diseased chicken flocks in Guangdong province, South China, between 2012 and 2013. Hemagglutinin (HA) genes of these strains were sequenced and analyzed and phylogenic analysis showed that 12 of the 19 isolates belonged to the lineage h9.4.2.5, while the other seven belonged to h9.4.2.6. Specifically, we found that all of the viruses isolated in 2013 belonged to lineage h9.4.2.5. The lineage h9.4.2.5 viruses contained a PSRSSR↓GLF motif at HA cleavage site, while the lineage h9.4.2.6 viruses contained a PARSSR↓GLF at the same position. Most of the isolates in lineage h9.4.2.5 lost one potential glycosylation site at residues 200-202, and had an additional one at residues 295-297 in HA1. Notably, 19 isolates had an amino acid exchange (Q226L) in the receptor binding site, which indicated that the viruses had potential affinity of binding to human like receptor. The present study shows the importance of continuing surveillance of new H9N2 strains to better prepare for the next epidemic or pandemic outbreak of H9N2 AIV infections in chicken flocks.

IR spectrum simulation of molecular structure model of Shendong coal vitrinite by using quantum chemistry method.

The structure of coal needs to be understood from a molecular point of view for clean, effective and high value-added utilization of coal. In the literature, molecular structure model of Shendong coal vitrinite (SV) was established by the authors on the basis of experimental results of ultimate analysis and 13C NMR, and the calculated 13C NMR spectrum of SV model was consistent with the experimental spectrum. In order to further verify the accuracy of SV structure model established by the authors, the infrared spectrum of SV structure model was calculated using quantum chemistry semi-empirical VAMP in this thesis. The results showed that the peak shape of calculated IR spectrum of SV structure model was similar to the experiment's, but the wave number of calculated IR spectrum was obviously higher than that of experimental spectrum. According to the calculated results for model compounds by using the same method, calculated vibrational frequency was higher than that of experiment for the same functional groups. Hence, the calculated IR spectrum should be corrected. After correction the calculated IR spectrum of SV structure model matched well with the experimental spectrum. In other words, the SV structure model can truly reflect the structure characteristics of SV.

[Raman spectroscopic characteristics of different rank coals and the relation with XRD structural parameters].

The Raman spectroscopic analysis for eleven different rank coals (57.58% to 94.01% of Cdaf, %) indicated that two distinct bands, i.e., D band (1340-1380 cm(-1)) and G band (1580-1600 cm(-1)), exist in the first order of Raman spectra, with the former being broader and the latter rather sharp. As the two bands were overlapped each other, each spectrum was fitted with two Lorentz peaks and the Raman information about position, intensity and FWHM of each band was thus obtained. The relation of these Raman parameters with Cdaf% showed that with the increase in C%, the position of D band and G band shifts to lower and higher frequency, respectively; the separation of the two band positions increases with the increase in C%; FWHM-D, FWHM-G and I(D)/I(G) have linear relationship with Cdaf% in the range of Cdaf% 75%-94%. The coal structural parameters, d002 and Lc from XRD are related with the position and FWHM of G band; the comparison of La from XRD and both from the Cancado and the KW equation indicated that the values from Cancado and the KW equation are unreasonable.

[Micro-FTIR study on structure of macerals from Jurassic coals in Northwestern China].

Jurassic coal in Northwest China is rich in resources and it is a necessary premise to reveal the chemical structure characteristics of the coal macerals in this region before the coal is put into reasonable and efficient use. Micro-FTIR technique was used to investigate the chemical composition and structures of vitrinite semifusinite and fusinite from Jurassic coal in Northwestern China. The results show that vitrinite and semifusinite have more aliphatic hydrogen, but fusinite has more aromatic hydrogen and C=O structure. The aliphatic hydrogen in semifusinite is higher than that in fusinite and it is this structure characteristic of semifusinite that led to the richer inertinite but higher reactivity of the Northwestern China coal. Not only vitrinite but also semifusinite and fusinite with weaker reducibility have less aliphatic hydrogen and more C=O structures than those with stronger reducibility. The different intensity of oxidation in the process of coalification is one of the causes that led to different type of reducibility.