外源精胺对断奶仔猪小肠黏膜成纤维细胞因子-2蛋白质表达量及小肠发育的影响

本试验旨在研究外源精胺对断奶仔猪小肠黏膜成纤维细胞因子-2( FGF2)蛋白质表达量及小肠发育的影响。将9窝胎次和初生体重相近的7日龄“杜×长×大”哺乳仔猪随机分配到0、12和15 mg/kg外源精胺组,每组3窝。仔猪从7日龄起补饲相应的饲粮,21日龄断奶后继续补饲断奶前饲粮至28日龄结束。从每窝选2头接近平均体重的仔猪屠宰,采集小肠及黏膜样品,测定FGF2蛋白质表达量和小肠的发育状况。结果表明：1)12 mg/kg外源精胺组仔猪小肠黏膜FGF2蛋白质表达量分别高于0和15 mg/kg外源精胺组,但3个外源精胺组仔猪小肠黏膜FGF2蛋白质表达量之间无显著差异(P>0.05)。2)12和15 mg/kg外源精胺组仔猪小肠绒毛高度和宽度分别极显著大于0 mg/kg外源精胺组( P<0.01),而12 mg/kg外源精胺组仔猪十二指肠和空肠黏膜绒毛高度与隐窝深度比值( V/C )分别极显著高于0 mg/kg外源精胺组( P<0.01)。3)28日龄仔猪小肠黏膜蔗糖酶和麦芽糖酶活性随外源精胺添加量的增加而升高。由此可见,给7~28日龄仔猪连续补饲外源精胺能提高28日龄仔猪小肠黏膜FGF2蛋白质表达量、V/C和二糖酶活性。     

Effect of Mediterranean saltbush (Atriplex halimus) ensilaging with two developed enzyme cocktails on feed intake,nutrient digestibility and ruminal fermentation in sheep

The aim of this study was to assess the effects of feeding Atriplex halimus (AH) silage treated with two developed enzyme cocktails to sheep on feed intake, nutrient digestibility and ruminal fermentation. The AH silage was treated without or with 2 L of ZAD1^® or ZAD2^®/1000 kg with 5% molasses and ensiled for 30 days. Barley grain (300 g/head/day) was fed as an energy supplement once daily at 10.00 hours and AH silage with or without enzyme treatment was offered ad libitum to animals twice daily at 09.00 and 16.00 hours. Sheep were fed on four experimental forage diets comprised of AH silage and barley (D1), AH silage treated with ZAD1^® and barley (D2), AH silage treated with ZAD2^® and barley (D3) and AH silage treated with a combination of ZAD1^® and ZAD2^® (1:1) and barley (D4). Ensiling AH with enzymes reduced its contents of neutral detergent fiber and acid detergent fiber. The dry matter intake of AH of D2, D3 and D4 decreased (P < 0.001) as compared to D1. However, enzyme‐treated diets had greater total digestible nutrients intake (P < 0.001) as compared to D1. The nutrients digestibility for D2, D3 and D4 were higher than those for D1 (P < 0.001), and were higher for D3 as compared to both D2 and D4. Sheep fed on D3 had highest (P < 0.001) ruminal total volatile fatty acids concentration, ammonia nitrogen concentration and microbial protein yield. It could be concluded that AH silage treated with ZAD1^® or ZAD2^® improved digestibility and rumen fermentation in sheep.     

外源C4-PEPC对水稻粒形和稻米品质及成分的影响

【目的】磷酸烯醇式丙酮酸羧化酶（phosphoenolpyruvate carboxylase,PEPC）参与植物碳代谢,并且在碳氮耦合代谢调节过程中扮演着重要角色。分析导入外源C₄-PEPC对水稻稻谷粒形和稻米品质及成分变化的影响,进一步阐明C₄-PEPC在C₃植物水稻中的作用。【方法】以航2号（对照）和转C₄-PEPC水稻为材料,采用万深SC-G型自动考种及千粒重分析仪分析稻谷的粒形,采用电镜扫描观察稻米内部淀粉粒结构,参照标准米质测定方法测定稻米品质(直链淀粉含量、胶稠度、碱消值);同时,测定稻米中支链淀粉、蔗糖、可溶性总糖及碳氮的含量,并采用高效液相色谱法测定稻米中的氨基酸含量。【结果】粒形分析表明,与对照航2号相比,转C₄-PEPC水稻的谷粒明显较短较窄,其长、宽、周长及千粒质量也明显较小。电镜扫描显示,航2号淀粉粒排列紧密,而转C₄-PEPC稻米淀粉粒排列明显比较松散。转C₄-PEPC株系稻米中直链淀粉含量明显较低,而支链淀粉含量明显较高,胶稠度和碱消值与对照无明显差别,垩白率和垩白度降低,蔗糖和可溶性糖含量极显著降低。转C₄-PEPC稻米的总氮含量明显较低,其中天冬氨酸、谷氨酸、丝氨酸、甘氨酸、组氨酸、精氨酸、苏氨酸、丙氨酸、酪氨酸、缬氨酸、胱氨酸、亮氨酸、苯丙氨酸、赖氨酸等14种氨基酸含量明显较低,而其余3种氨基酸,即脯氨酸、异亮氨酸、色氨酸含量与对照无明显差别。【结论】导入外源C₄-PEPC后,水稻谷粒变小,淀粉粒排列松散,稻米中直链淀粉、蔗糖、可溶性糖、总氮及大部分氨基酸含量降低,而支链淀粉含量升高。     

外源Ca2+对模拟酸雨胁迫下不同抗性水稻根系氮吸收的影响

为减轻酸雨对植物生长的不利影响,探究Ca²⁺对植物耐酸性的调控机制,本文以五优308（抗性种）和南粳9108（敏感种）两个品种水稻为研究对象,研究外源Ca²⁺对低强度酸雨（pH 4.5,SAR1）和高强度酸雨（pH 3.0,SAR2）胁迫下水稻幼苗根系生长、氮（NO₃^-和NH₄⁺）含量及吸收速率、ATP含量、质膜H⁺-ATPase活性及其磷酸化水平的影响。结果表明： SAR1处理下两个品种水稻的H⁺-ATPase磷酸化水平和活性增加（P<0.05）,促进ATP分解,增加供能,使NH₄⁺吸收增加（P<0.05）,但NH₄⁺仅在南粳9108根中过量积累（P<0.05）,引起铵毒,造成根系生长抑制,五优308中NO₃^-和NH₄⁺含量及其生长均未受影响（P>0.05）。SAR2处理下,两个品种水稻质膜H⁺-ATPase活性和NO₃^-、NH₄⁺吸收速率及含量均降低,根系生长受到抑制（P<0.05）,其中南粳9108降幅大于五优308。Ca²⁺+SAR1处理组两个品种水稻根系质膜H⁺-ATPase磷酸化水平和活性、NO₃^-和NH₄⁺吸收和积累以及根系生长均与对照（叶喷去离子水处理）差异不显著（P>0.05）。Ca²⁺+SAR2处理下H⁺-ATPase活性、NO₃^-和NH₄⁺吸收和积累以及根系生长低于对照（P<0.05）,但显著高于单一SAR2处理（P<0.05）。研究表明,外源Ca²⁺可有效保障模拟酸雨（pH 4.5、3.0）下质膜H⁺-ATPase磷酸化水平,促进H⁺-ATPase活性升高,缓解酸雨对NO₃^-和NH₄⁺吸收的抑制,维持根系生长。其中,外源Ca²⁺对相同强度模拟酸雨胁迫下五优308的调控效果优于南粳9108,说明外源Ca²⁺对酸雨胁迫下植物氮吸收的影响不仅受酸雨强度限制,而且也会受品种影响。本实验中,外源Ca²⁺对不同强度酸雨胁迫下不同抗性水稻氮吸收均有调控效果,合理利用外源Ca²⁺将有助于调节酸雨区农作物的营养吸收,缓解酸雨对农业生产的危害。     

茅苍术与内生菌互作信号对其活性成分的影响

为了了解内生菌对茅苍术道地性的影响,本文综述了各种内生菌引发的植物信号变化的异同,以及茅苍术内生菌在促进茅苍术生长以及多萜合成中的作用。内生菌可能被植物细胞表面受体所识别,通过活性氧、钙离子、一氧化氮3种第二信使以及多种植物激素信号引发植物代谢变化,进而累积次生代谢产物。受到影响的植物信号包括水杨酸、茉莉酸、脱落酸和乙烯。研究发现,内生菌的接种可能引起多种植物信号传递的变化,并且产生挥发油含量差异。     

基于奇异谱和相关性分析的木材声发射源直线定位算法研究

针对木材声发射（acoustic emission,AE）信号的随机特性,提出了一种基于奇异谱和信号相关性分析的木材表面AE源直线定位算法。首先,依据ASTM标准通过折断铅芯的方式分别在樟子松和榉木试件表面产生AE源,并在顺纹理方向布置2个AE传感器,其中采样频率设置为500 kHz。然后,采用奇异谱分析（singular spectrum analysis,SSA）算法提高AE信号的信噪比,再分别基于信号相关性和最大值分析2种方法计算AE信号在木材表面顺纹理方向的传播速度。最后,依据AE信号传播时差和计算速度,基于时差定位原理设计AE源定位算法。并针对SSA处理前后的AE信号,采用不同定位算法进行比较试验。结果表明,直接对原始AE信号采用基于信号相关性和最大值分析方法确定信号传播速度时,樟子松试件2个不同位置AE源的定位误差分别为51.8%、55.7%和75.7%、46.6%;榉木试件2个不同位置AE源的定位误差分别为52.0%、44.8%和37.7%、45.5%。而对于经SSA处理后的AE信号,樟子松试件相应的定位误差分别为5.1%、33.2%和2.6%、31.7%;榉木试件相应的定位误差分别为3.1%、54.9%和5.1%、22.9%。因此,对原始AE信号进行SSA降噪处理后,再基于信号相关性分析方法确定信号传播速度,能够显著提高木材表面AE源的定位精度。     

Effects of dietary thiamin on the physiological status of the grouper <Emphasis Type="Italic">Epinephelus coioides</Emphasis>

This study was conducted to evaluate the effects of dietary thiamin on the physiological status of the juvenile grouper, Epinephelus coioides. Graded levels of thiamin (0.08, 0.50, 2.12, 3.15, 4.63, 12.37 mg thiamin kg⁻¹ diet) were fed to grouper juveniles (mean weight: 16.97 ± 0.14 g) for 10 weeks. Although fish fed the thiamin-deficient (TD) diet showed no obvious symptoms of thiamin deficiency or increased mortality, those fed the lowest doses of thiamin (0.08 and 0.50 mg thiamin kg⁻¹ diet) had significantly decreased transketolase activity in the liver. In addition, the level of liver thiobarbituric acid reactive substances in fish fed the TD diet was 33–67% higher than that in fish with the thiamin-supplemented diet. There were no significant differences in superoxide dismutase activity between the different groups of fish.     

近海渔业安全救助通信网的核心技术--传输速率对网络阻塞的影响

"近海渔业安全救助通信网"(以下简称为"安全通信网")建设开通以来,在渔业安全生产中已经发挥了重要的作用。但随着我国海洋渔业经济结构的变革,现代通信技术的飞速发展,刚刚组建的"安全通信网"日趋落后,在实际运行中引出了诸多问题,难以适应渔业生产和管理的需要。本文仅从技术角度针对"安全通信网"中出现的网络阻塞问题,阐述几点意见。     

Protein kinase C in the spleen of the turbot (Scophthalmus maximus L.)

PKC activity was detected in spleen extracts from the turbot, Scophthalmus maximus, a teleost flatfish that is farmed commercially in several countries, in assays with the substrate EGF- R651–658 as phosphate acceptor. The activity was purified about 700-fold by a three-step chromatographic procedure (DEAE-cellulose, phenyl-Sepharose and threonine-Sepharose). Maximal activity was obtained in the presence of the typical PKC cofactors Ca2+ (0.1 mM) PtdS (20 g ml–1) and either DAG (2 g ml–1) or PMA (2 g ml–1). Activity was dose-dependently inhibited by H7 and by the PKC-specific inhibitors PKC19–36 and N-myristoylated PKC19–31. The rate of phosphorylation was highest with the PKC-specific substrate MARCKS161–175. In immunoblotting, MC5 (a mouse monoclonal antibody raised against bovine PKC) recognized bands of 80 and 100 kDa. Immunoblotting with antibodies raised against mouse PKC isozymes (, , , , , , and ) indicated the presence of all these isozymes in turbot spleen.     

Characterization of a cDNA encoding a homolog of actin-related protein 4 from a marine red alga Porphyra yezoensis

ABSTRACT:   A cDNA ( PyARP4 ) containing an open reading frame for a protein of 573 amino acids was identified in the marine red alga Porphyra yezoensis . The conceptual PyARP4 protein exhibits significant similarity to actin-related protein (ARP) 4 in the terrestrial plant Arabidopsis . Comparison of the deduced amino acid sequence showed moderate sequence identity (30%) to a conventional actin in P. yezoensis , as seen in comparisons between ARP and conventional actins of other organisms. A putative bipartite nuclear localization signal and an actin motif were found within the PyARP4 amino acid sequence. In a phylogenetic analysis, the PyARP4 was found to cluster with the ARP4 of other organisms. The expression level of PyARP4 did not change significantly among four developmental stages of life cycle and was lower than that of a conventional actin. This cDNA therefore may serve as a useful internal standard in gene expression analyses of differentially expressed genes in P. yezoensis .