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The montmorillonite mineral with different water contents and the sodium chloride aqueous solution were investigated by molecular dynamics simulation, and the different characteristics of water and ion within these two systems were compared. The simulation results reveal that the locations of interlayer counterions are influenced by the ismor-phous substitution of mineral, and the interlayer water molecules form hydrogen bonds with the tetrahedron oxygen atoms, oriented along the mineral surface. By the way, the self-diffusion coefficient of water molecules and counterions in the interlayer is smaller than those in aqueous solution, especially in the zz direction. But the peak intensity of radial distribution functions between oxygen/hydrogen and sodium and inter-water atoms in montmorillonite system is higher than those in bulk solution, which means that the degree of integration of water molecules within the crystal layers is higher than the aqueous solution. All of these quantitative results show that the structure properties of interlayer water are significantly different from the free water molecules, and this study laid the foundation for the next step to study the high-pressure mechanical properties of saturated clay. [ABSTRACT FROM AUTHOR]

Based on the summary and analysis of the theories and models which were adequate to interpret the compressibility of saturated clay under low stress, such as diffuse double layer theory and nonparallel plate model, it was found that these theory or model failed to describe the bilinear shape of compression curves under high pressure. In order to facilitate a qualitative description of the complete compression process of clay, the total pore volume was classified into three different structural levels, which were called macropore, micropore and interlayer pore respectively. Under high pressure, apart from the expulsion of the free water enmeshed inside the aggregates and particles, the organized water molecules that adsorbed on the crystals were also be squeezed out layer by layer. And when two surfaces or particles approached closer to a few nanometers, continuum theories of attractive van der Waals and repulsive double-layer forces often failed to describe these interactions; other Non-DLVO forces came into play. Therefore, a new thought of study on the compressibility of saturated clay under high to has been proposed in the last part of this paper. By describing the specific arrangement of water molecules around the clay miner with the lattice density functional theory and conducting steered molecular dynamics simulation, the constitutive relation of saturated clay under high pressure could be constructed on the basis of molecular scale. [ABSTRACT FROM AUTHOR]

Quantitative analysis of mixture samples’ components based on terahertz absorption spectra is one of the most important applications of THz technology. As is known to all, when the THz wave irradiates into samples, it will be scattered by the sample particles in the microscale, which is known as scattering. So THz absorption spectra of the experimental obtained samples are basically composed of two parts, samples’ intrinsic absorption of THz wave and the scattering. Especially when particles’ grain size of the samples is near or comparable to the THz wavelength, the scattering is so significant that it cannot be ignored. However, the scattering was always not taken into account while only the Lambert-Beer law was used in THz quantitative analysis, in which the absorption of light was described as linearly related with the material’s concentration. As a result, the accuracy was restricted. In this paper, the scattering in THz band was analyzed and absorption spectrum model of mixed sample’s THz was proposed. A series of quantitative analysis experiments proved the validity of this model. Through the comparision with the traditional method, the accuracy of the quantitative analysis was improved and the errors were basically below 3%. This research proved that scattering is important to improve the accuracy of THz quantitative analysis.

Terahertz time-domain spectroscopy (THz-TDS) is used to investigate the spectra properties of the wheat kernel with various deterioration degrees in the frequency range of 0.2-1.6 THz. The absorption coefficient and refractive index of normal, worm-eaten, moldy and sprouting wheat kernel were calculated. Comparison of the experimental data, clearly indicates that changes in the absorption coefficient and refractive index are recorded, different wheat samples have different optical parameters. The absorption coefficient of normal wheat sample is more obvious and higher than others; refractive index increases as the frequency increases. THz-TDS can be employed to evaluate the quality of wheat kernel nondestructively. The results show that THz-TDS is a promising and new experimental method for quality analyses and control for agricultural production detection. This study will provide an important guidance for nondestructive detecting the quality of stored-grain.

With recent development of THz sources and detector, applications of THz radiation to nondestructive testing and quality control have expanded in many fields, such as agriculture, safety inspection and quality control, medicine, biochemistry, communication etc. Compared with other detection technique, being a new kind of technique, THz radiation has low energy, good perspectivity, and high signal-to-noise ratio, and thus can obtain physical, chemical and biological information. This paper first introduces the basic concept of THz radiation and the major properties, then gives an extensive review of recent research progress in detection of the quality of agricultural products via THz technique, analyzes the existing shortcomings of THz detection and discusses the outlook of potential application, finally proposes the new application of THz technique to detection of quality of stored grain.

The sequences of mitochondrial ND2, CO2, and 16S rRNA genes and nuclear ITPR gene were obtained from 22 samples of 5 Apis species from China. The characteristics of the sequences and the pairwise distances among species were analyzed. Phylogenetic trees were reconstructed for Apis species using maximum parsimony, neighbor-joining and maximum likelihood methods together with the sequences of the other 4 Apis species downloaded from GenBank. Results supported that Apis species were divided into three major clusters: dwarf bees (A. florea and A. andreniformis), giant bees (A. dorsata and A. laboriosa), and cavity-nesting bees (A. mellifera, A. cerana, A. koschevnikovi, A. nigrocinta, and A. nuluensis). The dwarf honey bees were confirmed as basal lineage. Our study also revealed a high level of genetic divergence between A. dorsata from Hainan Island and China mainland.

Mesoporous activated carbons with high surface area were prepared from three waste polymers, i. e., tire rubber, polyvinyl chloride (PVC) and polyethyleneterephtalate (PET), by KOH activation. The adsorption/desorption characteristics of dyes (methylene blue and methyl orange) on the carbons were studied. The effects of pH, ionic strength and surface surfactants in the solution on the dye adsorption were also investigated. The results indicated that the carbons derived from PVC and PET exhibited high surface area of 2 666 and 2 831 m2 x g(-1). Their mesopore volume were as high as 1.06 and 1.30 cm3 g(-1), respectively. 98.5% and 97.0% of methylene blue and methyl orange were removed in 15 min by PVC carbon, and that of 99.5% and 95.0% for PET carbon. The Langmuir maximum adsorption capacity to these dyes was more than 2 mmol x g(-1), much higher than that of commercial activated carbon F400. Compared with Freundlich model, the adsorption data was fitted better by Langmiur model, indicating monolayer coverage on the carbons. The adsorption was highly dependent on solution pH, ionic strength and concentration of surface surfactants. The activated carbons exhibited higher adsorption to methylene blue than that of methyl orange, and it was very hard for both of the dyes to be desorbed. The observation in this study demonstrated that activated carbons derived from polymer waste could be effective adsorbents for the treatment of wastewater with dyes.

Objective: To investigate the enhancement effect of IL-4 expression plasmid on cathepsin B DNA vaccine of Schistosoma japonicum (Sj) in mice., Methods: The recombinant IL-4 plasmid constructed by cloning PCR amplified product of murine IL-4 gene into eukaryotic expression vector pcDNA3.1 was co-injected intramuscularly with Sj cathepsin B expression plasmid DNA to mice as the test group. The other three groups of mice were set up as control including IL-4 expression plasmid, Sj cathepsin B expression plasmid and two vacant vector plasmids. The expression of IL-4 and cathepsin B was visualized by immunohistochemistry. Challenge infection in mice was carried out 3 weeks after the last vaccination and immune protection was assessed by worm and egg reduction rates., Results: The recombinant mIL-4 plasmid and cathepsin B DNA vaccine were expressed in muscular cells of the vaccinated mice. Immunization with cathepsin B DNA plus recombinant mIL-4 plasmid yielded a 43.2 % of worm reduction rate and a 76.6% of egg reduction rate, showing a significant difference (P<0.01, P<0.05) compared with that of cathepsin B DNA vaccine alone., Conclusion: As an adjuvant, IL-4 DNA can improve the protective effect of cathepsin B DNA vaccine in mice against S. japonicum infection.

Objective: To clone and characterize new genes of Schistosoma japonicum, Sj, and to provide efficient vaccine candidates., Methods: Sj adult cDNA library was screened with rabbit sera raised against male worm soluble antigen. The inserted cDNA fragments from the positively selected clones were amplified with PCR and further sequenced, as well as characterized through internet NCBI GenBank software., Results: Eleven positive clones were obtained and two were verified by GenBank as new, including a novel gene designated as Sj-P8 (GenBank accession No. AF517843) and a new partial cDNA of Sj myosin (GenBank accession No. AY770506). The two new genes encoded a transmembrane protein of 75 amino acids and a myosin protein fragment of 212 amino acids respectively., Conclusion: The newly obtained genes may provide useful information for the research on Sj vaccine.

Aim: To study the influence of astragalus and zinc sulfate on the viscosity in erythrocyte membrane during intestinal I/R and their mechanism of action., Methods: Models of rabbits intestinal I/R injury were made. The effect of astragalus and zinc sulfate on the viscosity and malondialdehyde (MDA) in erythrocyte membrane, superoxide dismutase (SOD) in erythrocyte, oxidase (XO) in plasma and MDA tissues homogenate were observed., Results: The administration of astragalus and zinc sulfate decreased viscosity and MDA and XO, prevented the reduction of SOD, and alleviated I/R injury., Conclusion: Lipid peroxidation injury of the erythrocyte membrane was one of the pathogenesis of I/R injury, and astragalus and the zinc sulfate possessed effects of anti-lipid peroxide, stabilized erythrocyte membrane, increased red blood cell deform ability and raised microcircular perfusion.

Objective: To explore antigens possessing common immunogenicity with Schistosoma japonicum (Sj) cercariae antigens, and to find out new candidate antigens for schistosomiasis diagnosis and vaccine., Methods: Sj adult cDNA library was screened using sera from rabbits vaccinated with Sj cercariae antigen, the inserts of positive clones were amplified by PCR, all positive clones were sequenced and the data were analysed using Nucleotide BLAST software of NCBI and Expert Protein Analysis System of Swiss Institute of Bioinformatics., Results: Thirteen positive clones were obtained after three rounds of immunoscreening, and all amplified by PCR. Among four novel genes, SjCAI, SjCA, SjCAI-2 and SjCAI-3 (GenBank accession number: AF495883, AF515834, AY118086 and AY129303, respectively) encoded proteins with 353, 161, 137 and 72 animo acids respectively. Sj CAI protein contained six DNA-binding zinc fingers and showed some homology to gastrula zinc finger protein XLCGF48.2; proteins encoded by SjCA, SjCAI-2 and SjCAI-3 respectively contained N-glycosylation sites and phosphorylation sites., Conclusion: Novel genes were obtained by immunoscreening Sj adult cDNA library.

Objective: To subclone and express the new gene of Schistosoma japonicum (Sj) CAI and evaluate the immunoprotective effect of the recombinant molecule., Methods: The cDNA of SjCAI gene was subcloned into expression vector pGEX-5X-3 to form recombinants which were then used to transform to E. coli strain ER 2566. Expression was induced by IPTG. The mice were vaccinated with the expressed protein and the immunoprotective effect was tested., Results: Fusion protein of SjGST-CAI was highly expressed in E. coli as inclusion bodies. The worm reduction rate and the liver egg reduction rate in vaccination group of SjGST-CAI were 29.87% and 63.71%, respectively., Conclusion: SjCAI gene can be highly expressed in E. coli after subcloning into pGEX-5X-3 vector and the expressed fusion protein can induce immunoprotective effect against Sj in mice.