Dietary α‐linolenic acid affects lipid metabolism and tissue fatty acid profile and induces apoptosis in intraperitoneal adipose tissue of juvenile grass carp (Ctenopharyngodon idella)

A 56‐day feeding trial was conducted to elucidate the effects and mechanism action of dietary α‐linolenic acid (ALA, 18:3n‐3) on lipid accumulation and fatty acid profile of muscle, hepatopancreas and intraperitoneal fat (IPF) in juvenile grass carp using three isonitrogenous and isoenergetic semi‐purified diets containing 0.0% (control group), 1.0% and 2.0% ALA, respectively. The lowest intraperitoneal fat (IPF) ratio was found in 2.0% group. In the muscle, hepatopancreas and IPF, docosahexaenoic acid (DHA, 22:6n‐3) and eicosapentaenoic acid (EPA, 20:5n‐3) contents increased with the increase in dietary ALA. In the IPF, caspase 3, caspase 8 and caspase 9 showed the highest activities in 2.0% group, while the value of Bcl‐2/Bax (B‐cell leukaemia 2/Bcl‐2‐associated X protein) reached the lowest. Meanwhile, swelling of the IPF mitochondria was observed in 2.0% group. The gene expressions of fatty acid desaturase (FAD) and fatty acid elongase (ELO) in the hepatopancreas and muscle showed significantly higher levels in the treatment groups, whereas an opposite trend was existed in the IPF. Fatty acid synthase (FAS), sterol regulatory element binding protein‐1c (SREBP‐1c) in the IPF and hepatopancreas reached the lowest in 2.0% group. Overall, dietary ALA could promote n‐3 highly unsaturated fatty acids (HUFAs) synthesis and suppress the accumulation of lipid by decreasing the expression of related genes and promoting the apoptosis in IPF.     

荔枝树体N素分布及累积特点

采用整株枝解法,在采果后把9a生成年妃子笑和黑叶、3a生幼年妃子笑荔枝的根、木质部、皮部、叶、复叶柄5个器官分成14～16个部位,测定各个部位各个器官的N含量。结果表明,1)N在不同器官和不同部位含量是不同的。N含量在叶片最高,在根颈、主茎木质部、主根含量较低;在同级枝根中,皮部N含量显著高于木质部;荔枝枝干和根系,随着其粗度增加,其N含量基本上呈下降趋势,但成年树下降幅度比幼年树的大。2)成龄妃子笑与黑叶各部位各器官N含量没有显著差异,但成年树叶、复叶柄、末级侧枝皮部、木质部N含量高于幼年树相应部位相应器官N含量。3)荔枝N素累积在叶片最多,其次为枝干,根系N累积量较少,末级侧枝N素累积量占整株树N素累积量50%以上。     

超声波辅助提取白果粗脂肪

以自制白果粉为原料,分析了提取溶剂、粉料粒度、提取温度、超声波功率、料液比、提取时间及提取次数对白果出油率的影响。结果表明:石油醚(沸程60～90℃)是较适宜的提取溶剂,出油率为3.88%。最佳提取工艺为:白果粉粉碎度80目,提取温度25℃,超声波提取功率200 W,料液比1∶25(g/ml),每次提取时间40 min,提取次数2次。最优工艺条件下,出油率为3.86%,较索氏提取法,该工艺对白果粗脂肪的提取率为98.71%。     

基于径向基网络的含缺陷管道安全系数修正

安全系数是管道完整性评价方法的重要参数之一,传统评价方法仅考虑了管道所处地区等级对其影响,未能全面评价管道的真实安全状态。提取管道相关风险因素,比较各因素间相对重要程度并建立表征不同风险状态的分值体系,根据所得风险分值对安全系数进行修正,使得修正后的安全系数能够反映含缺陷管段实际风险状态;结合径向基网络方法的自学习特点,将各风险因素作为输入,修正后的安全系数作为输出,建立基于径向基网络的管道安全系数计算模型。由模型训练得出的修正安全系数与测试样本吻合度较好,验证了模型的准确性。结果表明:修正安全系数在考虑地区等级的基础上同时引入了其他重要风险因素的影响,为管道完整性评价中的安全系数取值提供了新的思路。     

丰产、优质、抗病油用亚麻品种“轮选一号”的选育

利用亚麻显性雄性核不育基因,通过多亲本杂交和互交,组建原始基础群,对不育株进行抗枯萎病抗性的轮回选择,以改良群体,从而培育出了以抗枯萎病为主、兼抗立枯病,丰产、优质的油用亚麻品种——轮选一号,为油用亚麻抗枯萎病育种开辟了一条新的有效途径。     

油料作物油脂合成调控研究进展

植物油脂不仅是人类可食用油的主要来源,也是人类生产生活中重要的可再生原料.本文概述了植物油脂的生物合成途径,从母体效应、QTL、GWAS等多个方面总结了油料作物油脂合成的遗传学研究进展,同时探讨了已知的油脂合成调控相关基因的功能.本文综述了该领域的研究现状,为深入了解油料作物油脂合成调控网络提供了参考,也为油料作物的分...     

Agronomic Practices Influence Maize Grain Quality

Abstract

Maize grain yields have increased dramatically over the past fifty years, and concurrently end-uses have proliferated requiring special quality characteristics. Plant breeders have developed many specialty types of maize, all of which are influenced by the agronomic practices used to produce the crop. Grain yield increases have resulted in lower protein concentration except when the yield increase resulted from nitrogen fertilizer application. Irrigation improves the biological value of protein, while higher nitrogen application rates alter the amino acid balance thereby reducing the nutritional value. Kernel breakage susceptibility and kernel density increase with higher nitrogen fertilizer application rates, and are reduced by irrigation. Extractable starch and oil concentration are largely influenced by hybrid choice, but small production practice effects have been documented. Essential mineral nutrient levels are often influenced by soil or foliar fertilizer application. The production of aflatoxin can be reduced by irrigation or other strategies to avoid water stress during grain fill. Although genetics usually exerts the largest effect on maize grain quality, agronomic practices are also important.     

蒸发油气回收技术的研究

介绍了几种常见的油气分离回收方法及该项目研究的同状与重点,探讨了油气吸收分离回收技术,指出常压常温吸收法宜作为吸收法的主要研究开发方案,并以适宜油气吸收剂的筛选作为研究的发出点。     

晚播条件下施氮量对稻茬小麦氮素吸收及产量的影响

为给安徽省江淮稻麦轮作区域晚播稻茬小麦高产栽培的氮肥合理施用提供依据,选用当地主栽品种扬麦18和皖垦麦076为试验材料,设置5个施氮水平(0、90、180、270和360 kg·hm~(-2)),分析施氮量对晚播小麦氮素积累与分配、糖氮比、氮素同化酶活性及产量的影响。结果表明,增施氮肥能显著提高小麦各器官的氮积累量以及营养器官花前贮存氮素转运量、转运效率和转运氮素对籽粒氮素的贡献率,氮素收获指数随着施氮量的增加而降低。随施氮量的增加,小麦各生育时期不同器官的糖氮比值显著降低。小麦的氮素分配比例在生育前期以叶片最高,成熟期籽粒中氮素分配比例显著高于其余部位,而小麦的可溶性糖分配比例在生育前期以茎鞘最高,成熟期籽粒较高。在0～270 kg·hm~(-2)施氮量范围内,增施氮肥后,两个小麦品种的硝酸还原酶、谷氨酰胺合成酶和谷氨酸合成酶活性均显著提高,穗数、穗粒数和籽粒产量均明显增加。继续增加施氮量至360kg·hm~(-2)时,氮素同化酶活性和产量无显著变化,说明施氮过多对小麦氮素同化和产量无益。土壤氮贡献率、氮肥农学利用效率和氮素偏生产力均随施氮量增加而降低。推荐江淮区域稻茬小麦晚播条件下适宜施氮量为180～270kg·hm~(-2)偏下限,可兼顾高产及氮素高效吸收和利用。     

乌鄯线冬季冷热油交替输送运行方案

为保障西部原油管道乌鄯线安全平稳运行,实现节能降耗输送,分析了乌鄯线和阿独乌线外输哈国油物性、沿线油温、地温数据,进而探讨了乌鄯线冬季运行冷热油交替输送的可行性。研究结果表明：长输原油管道冬季低输量运行,其进站油温差距不大并与地温的变化趋势一致,沿线地温为冬季冷热油交替输送的重要参数;采用冷热油交替输送工艺,哈国油常温输送对北疆油物性影响不大;乌鄯线冬季运行采用冷热油交替输送,节约燃料天然气约51.6%,节能降耗效果明显,说明乌鄯线冬季运行采用冷热油交替输送具有可行性。