放牧对鸭茅能量积累及分配的影响

通过长期放牧试验，探讨了不同放牧强度下亚热带高山草地鸭茅种群能量积累规律及能量在不同构件之间的分配特征。在无放牧的对照草地及采食率分别为55％、65％、80％的放牧草地，鸭茅热值随放牧强度的增加而呈单峰曲线型变化，一定强度范围内的放牧干扰提高了鸭茅热值及能量的积累；根部能量的积累随放牧强度的提高而逐渐减少。在禁牧草地，鸭茅种群能量主要被低密度的大分蘖丛所分摊，随着放牧强度的提高，种群能量则逐渐均摊给高密度的小分蘖丛。     

青土湖水面形成区土壤颗粒组成与化学特性变化

青土湖输水作为石羊河流域治理的一项关键措施,对保护湖区水资源和生态环境具有重要意义。在距青土湖水面边缘东南方向0-450 m的10个样点中分3层取0-60 cm土样,测定土壤粒径的质量百分比与全氮、全磷、全钾和电导率,分析青土湖水面形成后土壤颗粒组成与化学特性变化。结果表明, 随着离水面边缘距离的增加,土壤颗粒与化学特性呈有规律的增减变化,土壤粘粉粒组成与其全磷、全钾之间存在正线性相关。青土湖水面形成加剧了距水面边缘0-150 m处的土壤理化性质变化;土壤细粒及养分出现富集,分别在距水面边缘100-150 m和300 m处达到最大值。因此,土壤养分与土壤细物质的良好相关性表明,土壤粘粉粒变化可作为反映该区域土壤性状变化和评价衡量水面形成后土壤恢复程度的定量指标之一。     

树莓叶黄酮提取的正交试验和响应曲面法工艺优化对比

旨在为树莓叶黄酮的开发应用提供数据参考,通过正交试验与响应曲面法设计改良乙醇提取工艺,并通过HPLC建立树莓叶黄酮的色谱分离条件为:Agilent ZorBax SB色谱柱,流动相为1mg/mL乙酸-乙腈=72.5∶27.5,等度分离,柱温30℃,检测波长:257nm,完成树莓叶黄酮的初步分离,以及黄酮中芦丁含量的准确测定和验证。最佳提取工艺为:646mL/mL乙醇,料液比1∶12.5,41.9℃加热回流173.3min,最佳工艺所得提取率1.127%,响应曲面法最佳工艺提取率略高于正交试验法,且其工艺条件均较优于正交试验所得工艺,可为后期研发树莓叶芦丁兽用中药制剂提供理论参考。     

苏子降气汤对哮喘豚鼠引喘潜伏期及其行为学评分的影响

为观察和比较苏子降气汤对卵白蛋白(OVA)致敏豚鼠哮喘模型的治疗作用,随机将50只豚鼠分为5组,空白组、模型组、苏子降气汤高剂量组、苏子降气汤低剂量组、地塞米松组,每组10只.除空白组外,其余4组均用卵白蛋白致敏法制备哮喘豚鼠模型,造模成功后,用苏子降气汤或地塞米松治疗;第13天给药2h后,将各组豚鼠用雾化器予以1 g/L的OVA诱喘,记录各组豚鼠的“引喘潜伏期”、“行为学评分”以及“停止雾化诱喘后豚鼠从哮喘状态恢复到正常状态所需的时间”,连续诱喘3d并记录相关数据.结果显示,模型组和空白组相比,地塞米松组、苏子降气汤高、低剂量组均可不同程度延长豚鼠引喘潜伏期、降低其行为学评分、缩短停止雾化诱喘后豚鼠从哮喘状态恢复到正常状态所需的时间,具有显著性差异(P＜0.01),且苏子降气汤高、低剂量组上述效果接近地基米松组.说明苏子降气汤的确能够延迟哮喘的发作时间,并能减轻哮喘豚鼠发病的症状,提示苏子降气汤确实有良好的治疗哮喘作用.     

Recombinant pseudorabies virus expressing P12A and 3C of FMDV can partially protect piglets against FMDV challenge

One of the crucial factors for evaluation of an effective genetically engineered vaccine is whether susceptible animals are protected from virus challenge after vaccination. In this study, a recombinant pseudorabies virus (PRV-P12A3C) that expressed capsid precursor polypeptide P12A and nonstructural protein 3C of foot-and-mouth disease virus (FMDV) was used as a vaccine. The expression of P12A3C and its immunogenicity and protective efficacy against FMDV challenge were measured. Humoral and cellular immune responses were evaluated after each immunization. Subsequently, each piglet was challenged with 1000 ID₅₀ (50% infection dose) FMDV serotype O, named OR/80, which is used to produce vaccine in China. PRV-P12A3C induced a high level of neutralizing antibody and FMDV-specific lymphocytes. Inactivated vaccine provided 100% protection, and the vector strain (TK⁻/gE⁻/gI⁻) showed no protection. PRV-P12A3C induced 60% protection, compared with piglets that were vaccinated with TK⁻/gE⁻/gI⁻. The severity of clinical signs for the remaining two piglets was lighter and the appearance of vesicles was delayed.     

盐碱草地不同改良措施对沙打旺氮代谢的影响

对盐碱草地分别以农家肥、农家肥+磷肥、糠醛渣和醋糟处理后种植沙打旺(Astragalus adsurgens)进行改良,测定其不同生育时期的氮代谢指标,以探讨盐碱地生物改良的机制。结果表明:不同改良措施下,不同生育时期沙打旺叶片各氮代谢关键指标差异显著(P<0.05),其大小顺序为现蕾期>开花期>返青期>结实期。相同生育时期不同改良措施下沙打旺叶片氮代谢关键指标均显著高于对照(P<0.05),大小顺序为醋糟>糠醛渣>农家肥+磷肥>农家肥>对照。不同改良措施下,沙打旺在现蕾期氮代谢最旺盛,而结实期代谢最缓慢;醋糟、糠醛渣、农家肥+磷肥及农家肥改良盐碱地均可提高沙打旺的氮代谢。     

The stimulatory effect of insulin-like growth factor-1 on the proliferation, differentiation, and mineralisation of osteoblastic cells from Holstein cattle

This study investigated the effect of exogenous insulin-like growth factor (IGF)-1 on the proliferation and differentiation of osteoblastic cells from Chinese Holstein cattle and the resultant bone nodule formation and mineralisation in vitro. The osteoblastic cells were isolated and cultured, then identified using Giemsa and alkaline phosphatase (ALP) staining methods. The effect of different concentrations of IGF-1 on cell growth was assessed by MTT assay. The ALP activity and osteocalcin (OC) concentration in the osteoblastic cells were measured by a colorimetric assay and a radioimmmunoassay, respectively. Calcium nodules were observed using alizarin red S stain, while the content of matrix calcium was determined by atomic absorption spectrophotometry. Cell proliferation in the cultures was stimulated by IGF-1 at concentrations ranging from 1 to 200 ng/mL, with the maximum effect observed at 100 ng/mL. This effect was observed from day 1 and peaked at day 5, but decreased at day 7. At concentrations of 10 ng/mL and 100 ng/mL, IGF-1 significantly induced ALP activity, OC level, matrix calcium content, and nodule formation of the osteoblastic cells by 20–180% (P < 0.05 or P < 0.01), compared to controls. The results suggested that IGF-1 is an anabolic agent for the proliferation, differentiation, mineralisation and calcium content of dairy cow osteoblasts, and could therefore act as a potential treatment for the metabolic bone diseases in these animals.     

辛基酚对成年雄性小鼠血浆和脾脏抗氧化功能的影响

为探讨环境雌激素辛基酚对成年雄性小鼠血浆与脾抗氧化功能的影响,将20只成年雄性昆明小鼠随机分为4组,5只/组,即橄榄油溶剂对照组和辛基酚处理组。处理组分别为0、1、10、100mg/kg辛基酚剂量组,采用试剂盒测定血浆和脾组织中超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、总抗氧化能力(T-AOC)、丙二醛(MDA)、一氧化氮(NO)含量。结果表明,辛基酚显著升高血浆和脾组织中NO、MDA含量并降低血浆和脾组织中SOD、GSH-Px活性及T-AOC水平。说明辛基酚造成血浆和脾组织氧化与抗氧化系统的平衡受到破坏,从而降低抗氧化能力,造成氧化损伤。     

PEG引发对达乌里胡枝子种子发芽的影响

试验采用不同水势(0 Mpa、-0.2 Mpa、-0.6 Mpa和-1.2 Mpa)的PEG-6000溶液对2004年和2006年采收的达乌里胡枝子种子进行0 d、1 d和2 d的引发处理.结果表明:对于2004年采收的种子,引发1 d和引发2 d均能显著提高种子的发芽率、发芽势、发芽指数、活力指数和发芽速度(p<0.01).而-0-6 Mpa的PEG-6000溶液引发却显著降低了种子的活力指数和发芽速度(p<0.05);对于2006年采收的种子,引发1 d和2 d均能显著提高种子的活力指数(p<0.01),同时降低种子的发芽势、发芽指数和发芽速度(p(0.01).水势为-0.2Mpa的PEG-6000溶液引发能显著提高其发芽势(p<0.05),而-1.2Mpa的PEG-6000溶液引发却显著降低了种子的发芽指数和活力指数(p<0.05).