基于Web of Science^(TM)的“多糖表征”研究论文产出分析

通过对2008~2017年期间Web of Science^(TM)数据库中"多糖表征(polysaccharide characterization)"研究论文产出进行统计比较,分析全球范围内有关"多糖表征"研究情况。根据Web of Science^(TM)所有数据库,以"polysaccharide characterization"和"polysaccharide structure"为标题,通过文献计量学方法,从发文量、国家/地区、科研机构、期刊、作者、论文被引次数和研究方向等方面分析了"多糖表征"的研究现状和趋势。结果表明,全球在该领域的发文量呈现上升趋势;中国的发文量最多;机构中俄罗斯科学院发文量最多;中国科学院是国内发文量最多的机构;发文量最多的作者来自俄罗斯科学院;英国的《Carbohydrate Polymers》期刊载文量最多;被引次数最多的文章来自佐治亚大学;研究方向主要集中在生物化学与分子生物学、化学、农学等研究方向,学科交叉性较强;各国在多糖表征分析的方法运用上没有太大差异,相较于中国,美国、俄国、英国在多糖表征的应用上更为前沿。

Extraction,Isolation and Structural Characterization of Polysaccharides from a Red Alga Gloiopeltis furcata

Three kinds of polysaccharides： GFW, GFH and GFA, were sequentially extracted from a red alga Gloiopeltisfurcata with 25℃ and 85℃ water, and 60℃ 4% NaOH water solution. Based on the defatted alga, the yields of the polysaccharide were 57.9%, 2.5% and 2.6%, respectively. Their monosaccharide compositions, average molecular weights and structural characters were determined by gas chromatography （GC）, high performance liquid chromatography （HPLC）, fourier transform infrared spectroscopy （FTIR） or ^13C-NMR spectroscopy. The results showed that GFW, GFH and GFA were all composed of D-galactose （Gal） and 3,6-anhydro-L-galactose （AnG）, and particularly GFA also contained xylose （Xyl）. The average molecular weights of GFW, GFH and GFA were 22.6 kD, 26.5 kD and 49.8 kD, respectively, with the respective sulfate content 31.2%, 25.1% and 22.7%. The data of FTIR and ^13C-NMR confirmed the sulfate ester location at C6 ofgalactose. It is concluded that all the three polysaecharides extracted from Gloiopeltisfurcata were sulfated galactans, two being sulfated-agarose, and one being xylose-containing sulfated galactan.

Molecular cloning of Japanese eel Anguilla japonica TNF-α and characterization of its expression in response to LPS, poly I:C and Aeromonas hydrophila infection

As a potent pleiotropic cytokine, tumor necrosis factor-alpha （TNF-ct） plays an important role in innate immune responses. The cDNA sequence and genomic structure of the TNF-α gene （AjTNF-c0 in the Japanese eel （Anguilla japonica） were identified and characterized. The full-length AjTNF-α cDNA was 1 546 bp, including a 5＇-untranslated region （UTR） of 13 bp, a 3＇-UTR of 879 bp and an open reading frame of 654 bp encoding a protein of 218 amino acids. The full-length genomic sequence of AjTNF-ct was 2 392 bp and included four exons and three introns. The putative AjTNF-α protein contained TNF family signature motifs, including a protease cleavage site, a transmembrane domain and two conserved cysteine residues. Quantitative real-time reverse transcription PCR analysis revealed AjTNF-α expression in a wide range of tissues, with predominant expression in blood and liver. Lower levels of expression were seen in spleen, gills, kidney, intestine, heart, and skin, with very low levels in muscle. The modulation of AjTNF-ct expression after injection of eels with lipopolysaccharide （LPS）, the viral mimic, poly I：C, or Aeromonas hydrophila was assessed in blood, liver, and kidney. In blood, TNF-α mRNA levels increased rapidly and then rapidly decreased after stimulation with LPS, poly I：C or A. hydrophila. However, the response to LPS and A. hydrophila peaked at 6 h while for poly I：C the peak was at 12 h. In liver, after injection with A. hydrophila, an up- and down-regulation of AjTNF-ct expression occurred twice, peaking at 6 h and 24 h, respectively. No remarkable increase of AjTNF-α expression appeared in liver until 72 h after LPS or poly I：C treatment. In kidney, ApiNF-α expression increased significantly only at 72 h post-stimulation with LPS orA. hydrophila. Our results suggest that AjTNF-α plays an important role in fish in the defense against viral and bacterial infection.

Preparation and characterization of controlled-release fertilizers coated with marine polysaccharide derivatives

Encapsulation of water-soluble nitrogen fertilizers by membranes can be used to control the release of nutrients to maximize the fertilization ef fect and reduce environmental pollution.In this research,we formulated a new double-coated controlled-release fertilizer(CRF)by using food-grade microcrystalline wax(MW)and marine polysaccharide derivatives(calcium alginate and chitosan-glutaraldehyde copolymer).The pellets of water-soluble nitrogen fertilizer were coated with the marine polysaccharide derivatives and MW.A convenient and eco-friendly method was used to prepare the CRF.Scanning electron microscopy(SEM)and Fourier transform infrared spectroscopy(FTIR)were used to characterize the morphology and composition of the products.The nitrogen-release properties were determined in water using UV-Vis spectrophotometry.The controlled-release properties of the fertilizer were improved dramatically after coating with MW and the marine polysaccharide derivatives.The results show that the double-coated CRFs can release nitrogen in a controlled manner,have excellent controlled-release features,and meet the European Standard for CRFs.