添加葡萄籽等植物提取物对湘云金鲫生长性能及鱼体成分的影响

选用1344尾平均体重为105 g的健康湘云金鲫鱼种。随机分为4个处理,每个处理2个重复。Ⅰ组投喂基础饲料,Ⅱ、Ⅲ、Ⅳ组在基础饲料中分别添加4 m g/kg的黄酶素及10、20 g/kg葡萄籽等植物提取物。30 d后测定湘云金鲫的生长性能和鱼体成分。结果显示:Ⅲ组与Ⅰ组、Ⅱ组、Ⅳ组比较,增重率分别提高53.77%、45.43%、20.16%(P<0.05),饵料系数分别降低33.06%、31.02%、16.44%(P<0.05);鱼体蛋白质含量显著提高(P>0.05),体脂肪含量无显著变化(P>0.05)。因此,葡萄籽等植物提取物作为饲料添加剂能显著提高湘云金鲫的生长性能、降低饵料系数、改善鱼体品质,本试验条件下,其适宜添加量为10 g/kg。     

反应温度和时间对分光光度法测定乳粉中左旋肉碱的影响

采用分光光度法测定乳粉中左旋肉碱的含量,从温度和时间对反应的影响进行分析研究,确立了最佳反应温度为24℃,最佳反应时间为加入5,5＇-二硫双（2-硝基苯甲酸）和乙酰辅酶A反应6 min后归零,再加入乙酰肉碱转移酶反应6 min。此条件下该方法的回收率为98.3%～99.7%。     

桃雄性不育的表现形式及其败育途径

研究了桃［Ｐｒｕｎｕｓ ｐｅｒｃｉｃａ Ｂａｔｓｃｈ（Ｌ．）］２３个品种花粉发生发育和花粉败育过程中细胞形态学上的变化特征。结果表明：桃雄性不育的主要表现形式为空粒花粉和花药空囊及花粉形似发育正常，但生活力极低。导致空粒花粉产生的主要途径：①花粉母细胞减数分裂不正常；②花粉处于单核晚期至二核早、中期绒毡层细胞发生液化、增生现象。空囊产生的主要途径：①四分体至单核早期绒毡层细胞体积发生明显的增大、液化；②绒毡层细胞在四分体至单核早期发生增生；③造胞细胞或花粉母细胞生长发育不良。     

柔性垫网接触式间歇干燥单板的中间试验

利用柔性垫网接触式间歇干燥单板的方法对毛白杨单板进行干燥。中间试验结果表明，此方法提高了单板干燥质量，生产工艺可行。     

SLHY0.125型混合机简化、优化设计

通过对SLHY0.125型混合机配套设备的简化、优化设计,使之能够适应中、小型饲料加工厂的现实生产条件。     

断裂力学在木材学中的应用

本文介绍断裂力学基本概念及其在木材科学中的应用，应力强度因子的测试方法和计算方法以及国内外木材断裂力学的研究现状。     

Analysis of the influence of land finance on haze pollution: An empirical study based on 269 prefecture-level cities in China

Under the system of political centralization and economic decentralization, the expanding scale of land finance and the increasingly severe environmental pressure have jointly become crucial features of China's urban development. Therefore, it is of great practical significance to study the intrinsic mechanism of land finance on haze pollution for China's economy to achieve kinetic energy transformation and green development. This paper empirically analyzes the impact of land finance on haze pollution using a dynamic spatial Durbin model based on panel data of 269 prefecture-level cities in China from 2004 to 2017. The statistical results show that haze pollution has a significant “snowball effect” and space spillover effect. Land finance has a significant positive effect on haze pollution. Land transfer both by agreement and by bid invitation, auction, and listing have significant positive effect on haze pollution. However, the promoting effect of land transfer by agreement on haze pollution is significantly higher than that of land sale by bid invitation, auction, and listing. Furthermore, regional heterogeneity implies that for cities in the eastern region, land finance is conducive to alleviating haze pollution. In contrast, for cities in the central and western regions, land finance significantly promotes haze pollution.     

SSAP逆转座子分子标记在柿属植物遗传分析中的应用

对SSAP（特异序列扩增多态性;sequence-specific amplification polymorphism）在部分柿属植物种质鉴定和亲缘关系分析中的应用进行了研究,并对每个SSAP引物单独用于柿属植物遗传分析的性能作了探讨。基于5个逆转座子引物的25对SSAP引物组合在供试28份柿属（Diospyros L.）基因型中共扩增出1300个位点（多态位点93.38%）,每对引物平均产生52个位点（含48个多态位点）,表明SSAP是一种高多重比例系数（multiplex ratio）和高多态性的标记系统;经SSAP数据的UPGMA聚类和主坐标分析,原产中国、日本的柿种质（D.kakiThunb.）及柿的近缘种各自单独成组,该聚类结果与部分已知亲缘关系的试材十分吻合,表明SSAP技术可用于柿属植物亲缘关系研究。此外,在25对SSAP引物组合中筛选出3对具高信息含量的引物组合,将在柿属植物遗传关系研究中广泛应用。     

Resveratrol Downregulates Cyp2e1 and Attenuates Chemically Induced Hepatocarcinogenesis in SD Rats

Cyp2e1 plays an important role in chemically induced hepatocarcinogenesis. Resveratrol (REV) is known to prevent diethylnitrosamine (DEN)-induced hepatocarcinogenesis, but its effects on this process induced by DEN and 2-acetylaminofluorene (2-AAF) and the role of Cyp2e1 remain unclear. In this study, glutathione S-transferase placental form (GST-P)-positive foci were used as a marker of hepatocarcinogenesis. REV or diallyl disulfide (DADS, an inhibitor of Cyp2e1) significantly reduced both the area and number of GST-P-positive foci induced by DEN and 2-AAF. Treatment with REV or DADS also markedly decreased the expression of Cyp2e1 in the rat liver. By immunohistochemical staining of serial liver sections, we found that the expression of Cyp2e1 in GST-P-positive foci showed three distinct patterns: decreased in GST-P foci, increased in GST-P foci when compared with surrounding liver tissue and mixed type. The number of GST-P foci with increased Cyp2e1 expression was greater than the number of GST-P foci with decreased Cyp2e1. Protein levels of GST-P and Cyp2e1 were also higher in foci compared with surrounding liver tissue. REV or DADS significantly reduced the expression of GST-P and Cyp2e1 in both foci and surrounding liver tissue. Taken together, these results suggested that REV has a significant inhibitory effect on chemically induced hepatocarcinogenesis, which may be attributed to downregulation of Cyp2e1.     

耐高温植酸酶用于颗粒饲料对肉鸡生产性能及钙、磷利用率的影响

试验旨在研究肉仔鸡低磷日粮颗粒饲料中添加耐高温植酸酶对肉鸡生产性能及钙、磷利用率的影响。选取1日龄AA+肉仔鸡,随机分为6个处理,分别饲喂处理1(正对照,正常磷水平)、处理2(负对照,低于正常磷水平)、处理3(负对照+500U植酸酶)、处理4(高磷替代+500U植酸酶)、处理5(负对照+1000U植酸酶)和处理6(高磷替代+1000U植酸酶)试验日粮。试验结果表明:在制粒饲料中添加耐高温植酸酶是可行的。在相同有效磷水平下,随着植酸酶添加水平的提高,出栏体重有增加的趋势;在相同植酸酶添加量的条件下,随着有效磷替代水平的提高,出栏体重有降低的趋势。添加植酸酶有增加胫骨灰分和磷含量的趋势。在正常替代水平下,植酸酶的添加量以500～1000U/kg为宜。在本试验条件下,日粮添加500～1000U/kg植酸酶的情况下,进行磷酸氢钙的高水平替代也是可行的。