A study of the discrete and interactive effects of different polysaccharides on the digestibility of diets fed to barramundi (Lates calcarifer)

This study examined the single, paired and combined inclusion effect of a range of different polysaccharide types on the dry matter, protein and energy digestibility of diets fed to barramundi (Lates calcarifer). The different polysaccharides included pregelled starch, cellulose, lignin and pectin. There were significant differences among the digestibility parameters of the diets with the different inclusion levels of each of the different polysaccharide types. Using a manova analysis, effects were noted for polysaccharide type, inclusion level and interaction terms on the digestibilities of dry matter, protein and energy. Cellulose addition resulted in a reduction in both dry matter and energy that was largely commensurate with its inclusion level, but its effect on protein digestibility was marginal. Starch had the least effect on any of the digestibility parameters of all the polysaccharide types examined. Pectin had the largest effect on dry matter, while lignin had the greatest impact on diet protein and energy digestion. In the diets with paired combinations of polysaccharides, lignin and pectin were responsible for negatively synergistic interactions in all digestibility parameters. These results show that different polysaccharide classes can have distinctly different effects on diet digestibility parameters.     

几种番荔枝属果树的酯酶和多酚氧化酶同工酶分析

应用垂直板不连续聚丙烯酰胺凝胶电泳技术对番荔枝属的7种果树共14份材料进行酯酶和多酚氧化酶同工酶分析.结果表明,2种同工酶共表现出23条酶带,其中酯酶同工酶9条,多酚氧化酶同工酶14条,不同番荔枝种间酶谱差异较大.2种同工酶酶谱除不能区分2份红毛榴莲和2份毛叶番荔枝外,对其余的10份材料均可区分.实验用几个番荔枝种间的遗传距离在0.000～0.895之间.聚类结果将14份番荔枝材料分成了2类.     

Repellent Activity of Extracts of Wild Rice Species against Panonychus citri and Aphis citricola in Associated with Esterase Isoenzyme in Insests

China is one of the eight centers of origin for crop plants in the world and also the origin center of Asian cultivated rice. There are three species of wild rice i.e. Oryza rufipogon, O. officinalis and O. meyeriama in the South of China. Wild rice enjoys the second-class national protection in China due to its high research values and possession of abundant stress resistance genes. Wild rice has developed certain level of resistance against stress due to better genetic characteristics sin…     

套袋对芒果中甲基硫菌灵与吡虫啉农药残留的影响

用甲基硫菌灵与吡虫啉喷施套袋后的热农1号芒果,通过不同果袋处理、多次喷施农药和检测不同果实部位农药残留量3个试验研究套袋对芒果农药残留的影响及农药在果实上的残留和分布情况。采用高效液相色谱串联质谱法(UPLC-MS/MS)同时检测甲基硫菌灵、降解物多菌灵和吡虫啉,3种残留物最低检出限分别为0.5、0.12和0.5μg/kg。结果表明,不同果袋处理均能显著减少农药残留量,但白色纸袋(白袋)处理和黄色双层纸袋(黄袋)处理无显著差异。多次喷施农药时,对照(CK)果肉中3种农药总残留量在前50 d(喷药4次)持续极显著增加并超标,白袋处理在40 d(喷药3次)达到最大值并处于安全范围,果实成熟时CK和白袋处理农药残留均有所下降。不同果实部位的农药残留差异极显著,CK的外层果皮富集86.02%的甲基硫菌灵残留物和45.62%的吡虫啉,白袋处理则分别为66.93%和43.78%,但吡虫啉在白袋处理中的分布差异不显著。综上说明套袋能有效减少热农1号芒中的农药残留,甲基硫菌灵残留物主要富集果实表皮中,而吡虫啉内吸性更强,在果肉中也有大量残留,在多次喷药时,套袋能将2种农药控制在安全范围。     

Spirulina maxima Derived Pectin Nanoparticles Enhance the Immunomodulation,Stress Tolerance,and Wound Healing in Zebrafish

In this study, Spirulina maxima derived pectin nanoparticles (SmPNPs) were synthesized and multiple biological effects were investigated using in vitro and in vivo models. SmPNPs were not toxic to Raw 264.7 cells and zebrafish embryos up to 1 mg/mL and 200 µg/mL, respectively. SmPNPs upregulated Il 10, Cat, Sod 2, Def 1, Def 2, and Muc 1 in Raw 264.7 cells and tlr2, tlr4b, tlr5b, il1β, tnfα, cxcl8a, cxcl18b, ccl34a.4, ccl34b.4, muc5.1, muc5.2, muc5.3, hamp, cstd, hsp70, cat, and sod1 in the larvae and adult zebrafish, suggesting immunomodulatory activity. Exposure of larvae to SmPNPs followed by challenge with pathogenic bacterium Aeromonas hydrophila resulted a two-fold reduction of reactive oxygen species, indicating reduced oxidative stress compared to that in the control group. The cumulative percent survival of larvae exposed to SmPNPs (50 µg/mL) and adults fed diet supplemented with SmPNPs (4%) was 53.3% and 76.7%, respectively. Topical application of SmPNPs on adult zebrafish showed a higher wound healing percentage (48.9%) compared to that in the vehicle treated group (38.8%). Upregulated wound healing markers (tgfβ1, timp2b, mmp9, tnfα, il1β, ccl34a.4, and ccl34b.4), enhanced wound closure, and restored pigmentation indicated wound healing properties of SmPNPs. Overall, results uncover the multiple bioactivities of SmPNPs, which could be a promising biocompatible candidate for broad range of aquatic and human therapies.     

卡拉胶、瓜儿豆胶与果胶复配在酸奶中的应用

首先确定卡拉胶、瓜儿豆胶、果胶在酸奶中的用量范围,研究了三种胶体与变性淀粉复配做为酸奶增稠剂.通过感官评定与流变仪分析相结合,获得最适合酸奶发酵体系的胶体配比组合,果胶0.25‰,卡拉胶0.15‰,瓜儿豆胶0.55‰,变性淀粉4‰.     

茉莉酸甲酯重复刺激对白木香所结沉香中沉香四醇含量的研究

利用茉莉酸甲酯,重复刺激诱导白木香结香,提高所结沉香中沉香四醇的含量。白木香经锯伤、及 3 种浓度（0、10、50 g/L）茉莉酸甲酯重复刺激（仅 1 次、1 次/月、2 次/月、4 次/月）诱导结香,时长 6 个月,HPLC法测定所结沉香中沉香四醇的含量。结果表明：10 g/L 茉莉酸甲酯 2 次/月刺激诱导白木香所结沉香中沉香四醇含量最高,为 1.78 mg/g。由此可知,利用植物激素茉莉酸甲酯诱导、重复刺激均能明显提高白木香所结沉香中沉香四醇的含量。     

磁性催化剂Na2O·SiO2/Fe3O4的制备及其催化酯交换反应

以Na2SiO3为活性物质,以纳米Fe3O4为磁核制备磁性固体碱催化剂Na2O·SiO2/Fe3O4,通过正交实验,得到催化剂的最佳制备条件为：硅与铁的摩尔比2.5,晶化时间2h,煅烧温度350℃,煅烧时间2.5h,并通过震动样品磁强计（VSM）对催化剂的磁性进行表征,结果表明,所制备的催化剂Na2O·SiO2/Fe3O4具有较好的磁性和顺磁性,抗水性能优于传统均相碱催化剂;将其应用于棉籽油酯交换反应制备脂肪酸甲酯的最优工艺参数为：醇油摩尔比7：1,催化剂加入量5%,反应温度65℃,反应时间1h,搅拌速度400r/min,在此条件下,催化棉籽油酯交换反应的转化率99.6%,连续使用11次后活性90%以上。     

35%丙·苄可湿性粉剂的研制

介绍了35%丙.苄可湿性粉剂有效成分的筛选,主要技术指标的确定和贮存稳定性试验.经湖南、江苏两省田间试验结果表明,用量为0.75～0.9 kg/hm2,一次性防除抛栽稻田杂草的药效稳定在90%以上,且对水稻安全,增产显著.