W18Cr4V钢钻头断裂失效分析

通过对断裂的W18Cr4V钢钻头断口的宏观分析、硬度测试、化学成分分析和金相检验和微观分析,结果表明造成钻头断裂的主要原因是钻头材料中共晶碳化物不均匀度超标、热处理回火不足,而机械设计、机械加工不当是钻头断裂的诱因。     

18%氯胆·萘乙酸可湿性粉剂调节大蒜生长药效试验

18%氯胆.奈乙酸可湿性粉剂于大蒜生长期3次喷药处理,结果表明,18%氯胆.萘乙酸可湿性粉剂调节大蒜生长,可显著提高大蒜产量,且对大蒜生长安全,使用剂量以1 000.5～1 225.5g/hm2为宜。     

Differential Expression Analysis of MUC4 and MUC13 Genes Between Resistant and Sensitive Weaned Meishan Piglets to ETEC F18

MUC4 and MUC13 genes as important candidate genes for enterotoxigenic Escherichia coil (ETEC) F4 resistance,may play an important role in the process of against ETEC F18 infection in weaned piglets. In this study,ETEC F18-resistant and -sensitive weaned Meishan piglets were used,and the expression levels of MUC4 and MUC13 genes in 11 tissues (heart,liver,spleen,lung,kidney,stomach,muscle,thymus,lymph nodes,duodenum and jejunum) were determined by quantitative Real-time PCR. The results showed that MUC4 and MUC13 genes were broadly expressed with different expression levels in all the 11 tissues. In the thymus and lymph tissues,the expression of MUC4 gene in resistant piglets was significantly higher than that in sensitive piglets (P<0.05);In the lung tissue,theMUC13 gene expression level in resistant individuals was significantly higher than that in sensitive individuals (P<0.05),and in the intestinal tissues of duodenum and jejunum, the expression level of MUC13 gene was relatively higher in resistant individuals. Thus we speculated that the high expression of MUC4 gene in immune tissues and MUC13 gene in intestinal tissues might improve the immune ability of piglets,protect and lubricate the intestinal tract, and resist ETEC F18 infection.     

白细胞介素18的生物学功效及在动物疾病方面的应用

白细胞介素18（IL-18）是一种能诱导IFN-γ产生的新型细胞因子。它具有多种生物学功能．能诱导Th1细胞和自然杀伤细胞产生干扰素γ，促进T淋巴细胞和自然杀伤细胞表达FasL，有较强的抗肿瘤和抗微生物感染的作用。     

体外瘤胃发酵法研究添加鱼油对共轭亚油酸产生,尤其是t-11C18:1和t-10C18:1脂肪酸产量的影响

作者旨在研究鱼油添加对瘤胃内CLA的产生种类及t-11C18∶1和t-10C18∶1累积情况的影响。瘤胃液采集自山羊,用酸性缓冲液稀释,培养底物为添加豆油和不同量鱼油(0、50和100mg,对照组、LFO和HFO组)的干草和精料。在体外39℃厌氧培养24h,通过色谱法分析不同时间点的脂肪酸成分。尽管在早期培养时间点有抑制作用,但培养24h后添加鱼油显著增加了c-9,t-11CLA的含量。同时,在培养16和24h后,鱼油对t-10,c-12CLA的抑制有剂量效应。鱼油在培养16和24h后能显著增加t-11C18∶1成分(P<0.05),极显著降低t-10C18∶1成分(P<0.01),并导致在培养8、16和24h后使油酸的含量显著增加(P<0.01),并在不同培养时间点降低硬脂酸的比例(P<0.001)。培养16h后,鱼油能显著(P<0.05)增加t-11C18∶1和c-9,t-11CLA的量,但会显著降低(P<0.05)t-10C18∶1和t-10,c-12CLA的量。总之,研究结果表明,添加鱼油会显著增加瘤胃液中c-9,t-11CLA和t-11C18∶1的产量,降低t-10C18∶1he t-10,c-12CLA的量。     

在肉猪日粮中添加“壮达-18”复合添加剂的饲养效果

在肉猪日粮中添加“壮达＿１８”复合添加剂的饲养效果张建中陆耿胜华国浩马鸿祺（昆山市畜牧兽医沾２１５３００）（昆山市康壮达兽药厂）“壮达 １８”是昆山市康壮达兽药厂新开发的一种畜禽添加剂，为了了解“壮达＿１８”复合添加剂对促进肉猪生长发育、提高日增重和...