Time filter

Source Type

In order to protect DNA vaccine against degradation in alimentary tract of fish, poly(lactic-co-glycolic acid) (PLGA) nanoparticles encapsulating vaccine were prepared using W/O/W emulsification combined with spray drying technique in our laboratory. The characteristics of PLGA nanoparticles were described as follows: (1) shape, spherical; (2) size, <500. nm; (3) yield, ∼96.2%; loading percentage, ∼0.5%; encapsulation efficiency, ∼63.7%; supercoiled conformation percentage, ∼65%; (4) release dynamics, gradual release. In vitro transfection in SISK cells showed that PLGA nanoparticles could be utilized to transfect eukaryotes. After oral administration, FITC-labeled PLGA nanoparticles were detected in blood of fish, and RNA containing major capsid protein (MCP) gene information existed in various tissues of fish 10-90 days. In addition, the analysis of immune parameters in sera of treatment fish showed that: (1) infection rate of LCDV post-challenge, ∼16.7%; (2) prophenoloxidase, superoxide dismutase, respiratory burst, lysozyme and antibody levels, increased significantly (p< 0.05); (3) activities of serum complement, changed a little (p> 0.05). Pearson's correlation displayed that correlation of immune factors mentioned above (not including serum complement) were all positive for fish vaccinated. The data in this study suggested that PLGA nanoparticles were promising carriers for plasmid DNA vaccine and might be used to vaccinate fish by oral approach. © 2010 Elsevier Ltd.

Liu Z.,Shandong University | Liu Z.,Qingdao Agricultural University | Wang Y.,Shandong University
Automatica | Year: 2012

This paper addresses the disturbance decoupling problem (DDP) of mix-valued logical networks by using both the semi-tensor product of matrices and the matrix expression of logical functions, and presents a number of new results on the DDP. First, in order to solve the DDP, a new algorithm is proposed to construct a kind of Y-friendly subspace for the state space of mix-valued logical networks. Second, based on the constructed Y-friendly subspace, several necessary and sufficient conditions are obtained for the existence of decoupling controllers, and a new control design procedure is established to deal with the DDP. Finally, an illustrative example is studied by the new method proposed in this paper, and two kinds of decoupling controllers are designed. The study of the illustrative example shows that the new method is effective in dealing with the DDP of mix-valued logical networks. © 2012 Elsevier Ltd. All rights reserved.

A novel method for simultaneously determining the degree of deacetylation (DD), the degree of substitution (DS) and the distribution fraction of -COONa (δ -COONa) or -COOH (δ -COOH) in carboxymethyl chitosan (CM-chitosan) was developed by potentiometric titration. The effect of precipitate on the third inflection point, a common problem in the previous method, was eliminated by integrated application of alkaline titration and acidic titration. Calculating formulas of DS, DD and δ -COONa considering both the residues (GlcN and GlcNAc) and the carboxymethyl forms (-COONa and -COOH) were proposed. CM-chitosan products in different forms were examined to prove the reliability of the method. The standard deviation of DS, DD and δ -COONa of Na salt CM-chitosan (n = 9) were 0.109, 3.51% and 4.30%, respectively. As CM-chitosan was confirmed by IR and 1H NMR to be N,O-CM-chitosan, the method is suitable for the parameter determination of N-, O- and N,O-CM-chitosan. © 2011 Elsevier Ltd All rights reserved.

Wu B.,Chinese Academy of Forestry | Yang H.,Qingdao Agricultural University
PLoS ONE | Year: 2013

Passive restoration depending on native shrubs is an attractive approach for restoring desertified landscapes in semi-arid sandy regions. We sought to understand the relationships between spatial patterns of native shrubs and their survival ability in sandy environments. Furthermore, we applied our results to better understand whether passive restoration is feasible for desertified landscapes in semi-arid sandy regions. The study was conducted in the semi-arid Mu Us sandy land of northern China with the native shrub Artemisia ordosica. We analyzed population structures and patterns of A. ordosica at the edges and centers of land patches where sand was stabilized by A. ordosica-dominated vegetation. Saplings were more aggregated than adults, and both were more aggregated at the patch edges than at the patch centers. At the patch edges, spatial association of the saplings with the adults was mostly positive at distances 0.3-6.6 m, and turned from positive to neutral, and even negative, at other distances. At the patch centers, the saplings were spaced almost randomly around the adults, and their distances from the adults did not seem to affect their locations. A greater number of A. ordosica individuals emerged at the patch edges than at the patch centers. Such patterns may have resulted from their integrative adjustment to specific conditions of soil water supply and sand drift intensity. These findings suggest that in semi-arid sandy regions, native shrubs that are well-adapted to local environments may serve as low-cost and competent ecological engineers that can promote the passive restoration of surrounding patches of mobile sandy land. © 2013 Wu, Yang.

Quan H.,Qingdao Agricultural University
Open Civil Engineering Journal | Year: 2011

Although the specific surface area of type-2 fly ash, specified to be not less than 250 m2/kg in Japanese Industrial Standard, type-2 fly ash manufactured and available range from 300 m2/kg to 450 cm2/kg in Japan. In order to make clear of the effects of change in fineness of fly ash on the properties of air-entraining concrete, 2 series of laboratory experiments were carried out using 6 kinds fly ash with the specific surface area in the range from 250 m2/kg to 440 m2/kg. In the series 1 experiment, mix proportion was the same for 6 mixtures of fly ash, regardless of the change in fly ash properties. Water binder ratio, unit binder content, fly ash replacement ratio and unit water content were constant for all mixtures as well as the dosage of chemical admixture. In the series 2 experiment, 5 mixtures of concrete with the same materials, with the same unit binder content, with the same fly ash replacement ratio and with the same water binder ratio as those in the series 1 experiment were examined. However, unit water content and dosage of air-entraining agent were adjusted to obtain target slump and target air content. The test results indicated higher slump and lower air content and higher dosage of air-entraining agent for fly ash with higher specific surface area than those with lower specific surface area. Compressive strength was found to increase with the increases of specific surface area of fly ash, while drying shrinkage and carbonation were found to show different tendency with change in fineness of fly ash. © Hongzhu Quan.

Wang L.,Qingdao Agricultural University | Xiao J.,Qingdao Agricultural University
Advanced Synthesis and Catalysis | Year: 2014

The cascade [1,n]-hydrogen transfer/cyclization, recognized one century ago, has received considerable interest in recent decades and great achievements have been made. This cascade process can functionalize C(sp3)-H bonds directly into C-C, C-N, C-O bonds under the catalysis by Lewis acids, Brønsted acids or organocatalysts, and even under thermal conditions. This methodology has shown preeminent power to construct 5- or 6-membered heterocyclic as well as all-carbon rings. In this review, various hydrogen donors and hydrogen acceptors are categorized and discussed. Abbreviations: Cbz: benzyloxycarbonyl; Cod: 1,5-cyclooctadiene; CSA: camphorsulfonic acid; DCE: 1,1-dichloroethane; DFT: density function theory; DMF: N,N-dimethylformamide; DNBS: 2,4-dinitrobenzenesulfonic acid; DPP: diphenyl phosphate; ERC: electrocyclic ring closure; Fmoc: 9-fluorenylmethoxycarbonyl; HT: hydrogen transfer; IBX: ortho-iodoxybenzoic acid; m-CPBA: meta-chloroperbenzoic acid; MW: microwave; MS: molecular sieves; Pg: protecting group; p-TSA: para-toluenesulfonic acid; r.t.: room temperature; TCE: 1,1,2-trichloroethane; TFA: trifluoroacetic acid; TMS: trimethylsilyl. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Tian J.,Qingdao Agricultural University
Journal of Food Composition and Analysis | Year: 2010

Acetaldehyde is a natural by-product of the fermentation process, and its determination and quantitative analysis help to evaluate whether complete and proper fermentation has taken place. A new method was developed for sensitive determination and quantitative analysis of acetaldehyde in beer in our laboratory. Separation and determination of acetaldehyde were carried out by static headspace gas chromatography (HS-GC) with various experimental conditions. Calibration curves were obtained by plotting peak area versus concentration, and correlation coefficient of 6 standard level additions was ≥0.999. Measuring precision for acetaldehyde was ≤0.16% R.S.D. (relative standard deviation) under the condition of HS (25psi)/GC (16psi) when compared to HS (21psi)/GC (16psi). Configuration of two level temperatures made all the detecting values existing between upper control limit (UCL) and lower control LCL (limit) in comparison with one level configuration. In addition, the detecting threshold ranged from 0.5 to 12.1μgmL-1 using proposed parameters. Data displayed that accuracy and precision of detection were reliable for routine monitoring in beer. The method built in our laboratory could be used successfully to analyze the concentration of acetaldehyde in beer in the future. © 2010 Elsevier Inc.

Wang Z.-L.,Qingdao Agricultural University
Advanced Synthesis and Catalysis | Year: 2013

This review examines recent advances in asymmetric catalytic decarboxylative addition reactions which have become a powerful method to form C-C and C-X bond using relatively cheap and stable carboxylic compounds. In these reactions, new C-C or C-X bonds are formed with extrusion of carbon dioxide (CO2). Asymmetric decarboxylative addition reactions have become alternatives to traditional addition reactions. Various asymmetric reactions between carboxylic acids and unsaturated compounds are summarized. The challenges and opportunities of these reactions are discussed. © 2013 Wiley-VCH Verlag GmbH&Co. KGaA, Weinheim.

Wang F.-W.,Qingdao Agricultural University
Chinese Journal of Natural Medicines | Year: 2012

Aim: To isolate new and/or bioactive constituents from EtOAc extract of liquid culture of endophyte Guignardia sp. from the leaves of Undaria pinnatifida (Harv.) Sur. Methods: Isolation and purification were performed through silica gel column chromatograph, Sephadex LH-20 and reversed-phase ODS column and the structures of the compounds obtained were identified through a combination of spectral and chemical methods (IR, MS, 1H and 13C NMR). In vitro bioactive assays including antifungal activity against three human pathogenic fungi Microsporum canis, Tricophyton rubrum and Epidermophyton floccosom and cytotoxic activity against the human nasopharyngeal epidermoid tumor KB cell line were evaluated. Results: Seven compounds have been obtained from the liquid culture of the title endophyte: ergosterol peroxide (6, 22-diene-5, 8-epidioxyergosta-3-ol) (1), ergosterol (2), cyclo-(Tyr-Leu) (3), cyclo-(Phe-Phe) (4), cyclo-(Val-Leu) (5), cyclo-(Phe-Pro) (6) and cyclo-(Leu-Ile) (7). Compounds 1-3 and 6 inhibited the growth of M. canis with MICs of 10.0, 20.0, 50.0 and 5.0 μg·mL-1, respectively and compounds 1, 2 and 6 against T. rubrum with MICs of 15.0, 20.0 and 10.0 μg·mL-1, respectively and 1 and 6 against E. floccosom with MICs of 20.0 and 50.0 μg·mL-1, respectively. In addition, compounds 1, 3 and 6 exhibited cytotoxic activity against KB cell line with IC50 of 20.0, 10.0, 10.0 μg·mL-1, respectively. Conclusion: Compounds 1-7 were obtained from Guignardia sp. of U. pinnatifida for the first time, and compounds 1 and 6 had potent cytotoxic and antifungal activity. © 2012 China Pharmaceutical University.

Tian J.,Qingdao Agricultural University
Food Chemistry | Year: 2010

In order to determine flavours (diacetyl, pentanedione, acetoin and acetaldehyde) in beer, gas chromatography coupled with headspace sampling technique was developed in our laboratory. The calibrations were accomplished by six level standard addition methods, and relative coefficients were ≥0.999. Repeatability experiments were accomplished by detecting 20 successive same standard samples, which showed that detection precision was <2% relative standard deviation (RSD) for three flavours (diacetyl, pentanedione and acetaldehyde), and detection precision of acetoin was <2.5% (RSD). Four flavours gradually increased and then decreased during the process of fermentation, and they leveled off when the fermentation was over. The ratio (diacetyl/pentanedione) reflected the degree of contamination: normal beer had a ratio of approximate 1; the ratio (diacetyl/pentanedione) was higher than 1, displaying that beer was contaminated by microbes. Our data suggested that gas chromatography coupled with headspace sampling technique could be used successfully to determine flavours (diacetyl, pentanedione, acetoin and acetaldehyde) in beer. © 2010 Elsevier Ltd.

Loading Qingdao Agricultural University collaborators
Loading Qingdao Agricultural University collaborators