Tandem size exclusion chromatography-Polyacrylamide gel electrophoresis of humic acids

Humic acids (HAs) from four soils were fractionated by size exclusion chromatography (SEC) on Sephadex G-75. Three fractions were obtained in all humic acids, collected and assayed by Polyacrylamide gel electrophoresis (PAGE). The unfractionated HA from each soil was used as reference. Each chromatographic fraction formed one electrophoretic zone corresponding closely to one band of the reference sample with some admixture of the fractions preceding or following. The results indicate that fractionation of HAs by tandem SEC-PAGE can be successfully used for obtaining fractions of reduced polydispersity and different electrophoretic mobilities. Pyrolysis/methylation-gas chromatography-mass spectrometry of the full size preparations of HA and fractions with exactly defined molecular size and electrophoretic mobility showed a different distribution in humic components, mainly lipids, lignin derivatives and N-containing compounds.     

四海之腧取穴法对脑梗塞恢复期患者血脂及凝血系统影响的研究

目的 观察“四海之腧”取穴法对脑梗塞恢复期患者的血脂水平及凝血系统的影响。方法 将60例患者随机分为治疗组和对照组,每组各30例。两组患者均接受基础治疗,治疗组配合“四海之腧”取穴法,对照组配合常规针刺,3个疗程后,观察治疗前后血脂及凝血系统相关指标情况。结果 两组患者治疗前后血脂水平和凝血系统指标比较差异均有统计学意义（P<0.05）,且治疗组疗效优于对照组（P<0.05）。结论 “四海之腧”取穴法可调节脑梗塞恢复期患者的血脂水平及血液流变学状态,疗效确切,值得临床推广应用。     

2007～2008年国际反刍动物营养研究进展 Ⅴ.脂肪(酸)营养

反刍动物产品如牛奶,牛、羊肉等,是人类重要的膳食组成,其脂肪品质及脂肪酸组成与人体健康密切相关,如何合理调控反刍动物脂肪代谢过程,优化饲养模式,改善产品脂肪品质是反刍动物脂类营养研究的关键问题。作者对2007～2008年反刍动物脂类营养研究进展作一简要综述。国内的研究热点主要集中于脂肪酸代谢通路的研究、补充脂肪（脂肪酸）对反刍动物生产性能及产品脂肪酸组成的影响和瘤胃惰性脂肪的应用研究。而国外反刍动物营养脂类研究中除了上述3点外还对乳腺脂肪酸代谢调控和瘤胃后脂肪酸消化、吸收方面有较深入的研究。     

罗氏海盘车性腺脂质的微波提取及其成分分析

为优化罗氏海盘车性腺脂质的微波提取工艺并分析其脂质成分和脂肪酸组成,该研究采用微波辅助提取技术对罗氏海盘车性腺脂质的提取工艺进行优化,同时通过核磁共振和气相色谱-质谱分别对其脂质成分和脂肪酸组成进行分析。试验结果表明,罗氏海盘车性腺脂质的最佳提取工艺条件:以乙酸乙酯为提取溶剂、液料比7 mL/g、提取时间12 min、提取温度60℃,在此优化条件下,罗氏海盘车性腺脂质的提取率为33.82%。罗氏海盘车性腺脂质的主要成分为甘油三酯和磷脂,胆固醇和游离脂肪酸含量较低;脂肪酸以C14:0、C16:0、C18:1n-7、C20:1n-11、C20:5n-3(eicosapentaenoic acid,EPA)和C22:6n-3(docosahexaenoic acid,DHA)为主,C20:5n-3和C22:6n-3总质量分数为21.56%,且n-3型与n-6型多不饱和脂肪酸的比值高达8.72;同时罗氏海盘车性腺脂质的脂肪酸致动脉粥样硬化指数(atherogenic index,AI)和血栓形成指数(thrombogenic index,TI)分别为0.81和0.29,表明罗氏海盘车性腺脂质能有效预防动脉粥样硬化和血栓形成,具有很高营养价值和脂质开发潜力,可作为C20:5n-3和C22:6n-3等功能性脂肪酸的重要膳食来源。该研究为罗氏海盘车性腺脂质的微波提取、成分分析和综合开发利用提供了一定的理论依据。     

Puroindolines are associated with decreased polar lipid breakdown during wheat seed development

The wheat Hardness (Ha) locus consists of Puroindoline a (Pina) and Puroindoline b (Pinb) and controls whether wheat is soft or hard textured. PINA and PINB act cooperatively to create grain softness and are associated with increased polar lipids at seed maturity. Here we examined developing seeds varying in PINA or PINB content to identify when polar lipid differences occur. One population carried Wild Type (WT) PINA while varying for the presence of PINB, while the other population carried a WT PINB and segregated for PINA. For the PINB segregating population, polar lipids were maximal on a per mg dry weight basis at 7–14 days after anthesis (DAA) while for PINA segregating population, total polar lipids were maximal at 7–21 DAA. The most abundant polar lipids at maturity were mono- and di- galactosyldiglyceride. No individual polar lipid species were specific to PINA or PINB. The effect of both PINA and PINB increased throughout seed development with greater decreases in the most abundant polar lipids in genotypes lacking either PINA or PINB. The results indicate that PINA and PINB act cooperatively to prevent polar lipid breakdown during seed maturation and that this process is central to the development of grain softness.     

壳聚糖涂膜对常温保鲜番木瓜膜脂过氧化的影响

以马来6号番木瓜果实为试材,用不同浓度壳聚糖(CTS)涂膜处理后放入人工气候箱中于25±2℃下贮藏,研究了壳聚糖对常温保鲜番木瓜膜脂过氧化的影响。结果表明,一定浓度的壳聚糖处理可显著降低膜脂过氧化过程中脂氧合酶（LOX）活性的增长,减缓超氧阴离子（O2-）的产生速率,提高超氧化物歧化酶（SOD）和超氧化物酶（POD）等膜保护酶的活性,减少了膜脂过氧化物产物丙二醛（MDA）的积累,从而有利于果实硬度的维持。结论：壳聚糖可减轻膜脂过氧化程度,延缓番木瓜果实的后熟,以1.25%处理浓度最好。     

粳稻精米脂肪含量和组分对蒸煮品质的影响及其对氮素的响应

选用6个穗型不同的粳稻品种,采用7个氮肥处理,研究了精米中脂肪含量和组分对稻米直链淀粉含量和RVA特征值的影响及其对氮素的响应。结果表明,水稻精米中脂肪含量及组分存在显著的基因型差异。小穗型品种宁粳1号、早丰9号和武育粳3号精米中粗脂肪含量和淀粉脂(SL)含量分别大于或等于与之对应的大穗型品种宁粳2号、徐稻4号和9522; 精米中非淀粉脂(NSL)含量小穗型品种宁粳1号、早丰9号和武育粳3号均小于或相近于与之对应的大穗型品种宁粳2号、徐稻4号和9522。氮素对精米脂肪含量及组分的影响小于基因型,而且对于不同的基因型水稻氮素对脂肪的调控作用不同。精米中粗脂肪含量及各脂肪组分含量与直链淀粉含量(AC)及RVA特征值关系密切。精米中粗脂肪含量与脱脂前后的崩解值(BDV)呈极显著负相关,SL与直链淀粉含量(AC)、脱脂前后的消减值(SBV)和回复值(CSV)均呈显著或极显著负相关。从这些结果可以看出,精米中脂肪含量尤其是SL含量对稻米的蒸煮食味品质有显著影响,提高精米中SL含量能够提高稻米的蒸煮食味品质。     

Inheritance of groat-oil content and high-oil selection in oats (Avena sativa L.)

Summary The potential for breeding for high groat-oil content in oats was investigated by (a) conducting generation means analyses on data from three matings among adapted Avena sativa L. cultivars, (b) practicing one cycle of phenotypic recurrent selection in a segregating population derived from eight species backcrosses (Avena sativa x (A. sativa x A. sterilis)) among 24 parents, and (c) identifying transgressive segregates from interspecific (A. sativa x A. sterilis) matings.Additive gene action was the most important component in explaining the variation among generation means for groat-oil content. Dominance and epistatic interactions involving dominance were not significant in any mating. Significant residual genetic variation occurred in one mating, even after additive, dominance, and three digenic interactions were fitted. The importance of additive genes action implies that desired allelic combinations for high groat-oil content can be obtained in pure-line cultivars.One cycle of phenotypic recurrent selection using single plants as the selection units resulted in a genetic gain of 1.7 to 2.1% in groat-oil content. Individual plants selected for initiating the second cycle had from 9.5 to 12.6% groat oil.Over all 12 interspecific matings, the F₂ progeny means were similar to the midparent values. Only two were significantly deviant. Transgressive segregates for high and low groat-oil content from these matings provided evidence that A. sterilis possesses alleles for high and low groat-oil content that are different from those in the gene pool of cultivated oats.Journal Paper No. J-11340 of the Iowa Agric. and Home ECon. Exp. Stn., Ames, Iowa 50011. Project 2447. This study was supported in parts by grants from the Iowa Committee for Agricultural Development and the International Harvester Company.     

Effect of colocasia leaves (Colocasia antiquorum) on serum and tissue lipids in cholesterol-fed rats

Dried colocasia powder (10% and 20%) was fed to hypercholesterolemic rats for a period of one month to explore the effect on serum lipids and tissue lipids. The results indicated that there was a significant increase in total lipids, total cholesterol, and triglycerides levels in the cholesterol fed rats. Liver cholesterol showed a slight reduction which was non-significant, while an increase in liver triglyceride was observed in rats fed with 10% and 20% colocasia leaves diet with or without cholesterol. All these observations indicate an aggravating effect of colocasia leaves on serum and tissue lipids in cholesterol-fed rats.     

Influence of sulfur-amino acid content variation in plant vs animal protein on serum and tissue lipids in rats

The objective of the study was to determine the effects of methionine and cysteine supplementation of soy protein isolate and casein on serum and tissue lipid levels in rats. Sixty male, weanling, Wistar-Kyoto rats were fed two sources of protein (casein or soy protein isolate) and three variations of sulfur-amino acid supplementation (none, methionine, or cysteine). At this level of protein intake (10% by weight), rats fed soy-based diets had similar serum lipid concentrations than rats fed casein-based diets. Choline was not added to the diet in order to be able to assess independent influences of methionine and cysteine on lipid metabolism. Overall, serum lipid values were greater in rats fed proteins supplemented with methionine while the addition of cysteine produced lower lipid levels. Liver lipid concentrations were increased tremendously upon cysteine supplementation of soy protein isolate. Protein quality, as determined by protein efficiency ratio, was improved by supplementation of either sulfur-amino acid; however, methionine had the greatest effect. Results indicate that the sulfur-amino acids influence lipid metabolism in the absence of dietary choline. The mechanism by which this occurs is not known.