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饲粮精氨酸添加物影响断奶初期仔猪小肠微脉管发育
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作者 Zhan Z F Ou D y +3 位作者 Piao X S Kim S W liu y h Wang J J 《饲料博览(技术版)》 2008年第9期39-39,共1页
试验旨在评价饲粮精氨酸水平对断奶初期仔猪小肠微脉管发育的影响。选择24头初始体重为(5.0±0.3)kg的杂交仔猪,单独饲养,并随机分配到3个饲粮组中,每个饲粮组8头。试验饲粮L-精氨酸含量分别为0、0.7%和1.2%。仔猪自由采食,试验期10... 试验旨在评价饲粮精氨酸水平对断奶初期仔猪小肠微脉管发育的影响。选择24头初始体重为(5.0±0.3)kg的杂交仔猪,单独饲养,并随机分配到3个饲粮组中,每个饲粮组8头。试验饲粮L-精氨酸含量分别为0、0.7%和1.2%。仔猪自由采食,试验期10d。在试验第3、6和10d采集血样。在第10d,每组随机选择6头并屠宰采集组织样。与对照猪相比,饲粮添加L-精氨酸0.7%显著增加试验第6、10d亚硝酸盐和硝酸盐(一氧化氮的稳定氧化产物)的空肠浓度,肠绒毛高度,血浆脯氨酸和精氨酸浓度(P<0.05)。与对照组和添加L-精氨酸1.2%组相比,饲粮添加L-精氨酸0.7%显著增加十二指肠黏膜下层、回肠黏膜及黏膜下层中CD34免疫活性表达,十二指肠黏膜下层、空肠黏膜及黏膜下层和回肠黏膜中脉管内皮生长因子(VEGF)表达(P<0.05)。与对照组相比,饲粮添加L-精氨酸1.2%显著增加空肠内皮素-1浓度(P<0.05)。在试验第6、10d,与对照组相比,添加L-精氨酸1.2%使十二指肠黏膜中VEGF免疫表达和血浆赖氨酸浓度显著降低(P<0.05)。总之,结果显示L-精氨酸在更低水平时对微脉管发育有有益作用,但是在更多摄入时有不利作用。饲粮添加L-精氨酸0.7%是改善断奶初期仔猪小肠微脉管发育的一个有效方法。 展开更多
关键词 精氨酸 断奶初期 仔猪 微脉管 发育 小肠
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Relationship Between Coarse/Fine Aggregate Space Coefficient and Properties of Self-compacting Concrete 被引量:1
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作者 LONG G C liu y h XIE y J 《武汉理工大学学报》 CAS CSCD 北大核心 2010年第17期158-164,169,共8页
For the sake of expounding the relationship between coarse/fine aggregate volume content and properties of self-compacting concrete(SCC),a parameter of aggregate space coefficient is proposed to study systematically t... For the sake of expounding the relationship between coarse/fine aggregate volume content and properties of self-compacting concrete(SCC),a parameter of aggregate space coefficient is proposed to study systematically the effects of fine/ coarse aggregates on workability,strength and volume stability of SCC by experiments. The optimized coarse/fine aggregates volume content of SCC was discussed with regard to specified properties. Results indicate there is a close relationship between aggregate space coefficient and properties of SCC not only in fresh state but also in hardened state. With the increasing coarse/fine aggregate space coefficients,workability of fresh SCC will be improved,the compressive strength decreases slightly and shrinkage of SCC however increases. When coarse aggregate space coefficient ranges from 1.2 to 1.7 and the fine aggregate space coefficients is from 0.6 to 1.0,SCC can meet self-compactability requirements in fresh state and have a good volume stability and appropriate strength in hardened state. The results will benefits for developing a new mixing design method for SCC. 展开更多
关键词 self-compacting concrete aggregate space coefficient WORKABILITY compressive strength SHRINKAGE
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