花粉抗动物脑衰老的机制研究

本实验使用花粉抗大鼠脑衰老，发现花粉具有预防动物海马、纹状体、下丘脑等脑区DNA的损伤作用。因此花粉可能是全世界营养学家正在寻找具有预防或修复的DNA损伤的食品之一。     

Myelodysplasia, hypophosphataemia, vitamin D and iron deficiency in an alpaca.

A pregnant 2-year-old alpaca was presented for evaluation of progressive weight loss, decreased appetite and lethargy that developed in winter. Haematologic and serum biochemical analyses revealed marked anaemia, leukopenia, severe hypophosphataemia and mild hypocalcaemia. Evaluation of bone marrow core biopsies and aspirates revealed an increased proportion of immature haematopoietic cells, without sufficient numbers of blast cells to be termed an acute myeloid leukaemia (AML). 1 The haematological and bone marrow findings were suggestive of myelodysplastic syndrome (MDS). The anaemia, leukopenia, lethargy and weight loss remained refractory to medical therapy and the alpaca was euthanased on humane grounds.     

Quantitative studies of the in vitro production of pipecolic acid by rumen protozoa and its degradation by rumen bacteria

An in vitro study was conducted to quantitatively investigate the metabolism of pipecolic acid (Pip), a neuromodulator, by mixed rumen bacteria (B), mixed rumen protozoa (P), a combination of B and P (BP), species‐enriched rumen protozoal suspension (Polyplastron sp., Diploplastron sp., entodinia and Entodinium caudatum) and pure cultures of several isolates of rumen bacteria (Prevetolla bryantii, Prevetolla albensis, Streptococcus bovis, Veillonella parvula, Megasphaera elsdenii and Ruminococcus albus). Only P produced Pip from L‐lysine (1.0 mmol/L L‐Lys) at a rate of 83.5 ± 1.6 µmol/L/h and even in BP, Pip was produced from L‐Lys by P and increased at a rate of 31.2 ± 3.8 µmol/L/h. Pip production by P was highest when the substrate (L‐Lys) concentration was 6 mmol/L and then the rate was 580 ± 36 µmol/L/h. Pipecolic acid production by P suspension enriched with different species of protozoa showed that Polyplastron sp. had the highest Pip production rate of 0.907 ± 0.092 µmol/L/mg protozoal protein per h, and Diploplastron sp. had the lowest rate of 0.55 ± 0.13 µmol/L/mg protozoal protein per h. The addition of D‐Lys (1.0 mmol/L) as a substrate to the P suspension revealed that P were also able to produce Pip from D‐Lys, though at a lower rate (1/3) compared with L‐Lys (1.0 mmol/L), suggesting the presence of epimerases in P. It was confirmed that B were unable to produce Pip from L‐ or D‐Lys. Only B degraded Pip (1.0 mmol/L) after a lag phase at a rate of 56.0 ± 1.5 µmol/L/h. The B suspension was able to degrade D‐Lys, though the products were not identified. Pip degradation by pure culture of some species of rumen bacteria showed that P. bryantii and R. albus had the highest rate followed by P. albensis, S. bovis and M. elsdenii with a low rate of Pip degradation. Veillonella parvula showed no ability to degrade Pip. The results suggest that a fairly large proportion of rumen‐produced Pip is likely to be absorbed by the host animal before degradation by rumen bacteria.     

N-甲基-D-天门冬氨酸对鼠小脑颗粒细胞存活的影响

目的：研究N-甲基-D-天门冬氯酸(N-methyl-D-aspartate，NMDA)对鼠小脑颗粒细胞(CGC)存活的影响。方法：光镜观察NMDA和酒精对细胞所产生的作用。结果：NMDA在无酒精条件下促进细胞生存，并抑制酒精对细胞所产生的神经毒性作用而减少细胞死亡。结论：NMDA对小脑颗粒细胞具有神经营养和神经保护作用。     

Role of prostaglandin in the control of ovulation in the Japaneseeel Anguilla japonica

ABSTRACT:   The in vitro effects of 17,20β-dihydroxy-4-pregnen-3-one(DHP) and prostaglandins (PGE₁, PGE₂, PGF_1α,PGF_2α) on ovulation in the Japanese eel Anguillajaponica were examined. Oocytes with follicle layers at themigratory nucleus stage (approximately 850–900 µmdiameter) were removed using a polyethylene cannula from artificiallymatured fish. At concentrations of 10 and 100 ng/mL,DHP was found to induce both germinal vesicle breakdown and ovulation.The prostaglandins, except for PGE₁, effectively inducedovulation of previously matured oocytes by DHP treatment in vitro .Prostaglandin F_2α was the most effective. Asignificant increase in ovulation rate was observed even at a concentrationof 0.01 µg/mL PGF_2α.Indomethacin blocked the in vitro ovulation induced by DHPand addition of PGF_2α reversed indomethacin-blockedovulation. Actinomycin D and cycloheximide blocked DHP-induced ovulationand PGF_2α reversed the effects of both inhibitors. Theseresults indicate that DHP induces ovulation through endogenous prostaglandinsynthesis in the follicle layers of the Japanese eel.     

山梨醇对枇杷原生质体分离和培养的效应

以山梨醇作为游离枇杷原生质体的渗透压稳定剂，效果较同质量分数的甘露醇差，但随着山梨醇质量分数的提高，原生质体得率递次升高，至１６％时，可达１．３×１０６ｇ－１．原生质体经液体培养在附加一定浓度糖类的培养基上，可出现第１次细胞分裂并持续分裂，１０％蔗糖加５％山梨醇是原生质体早期培养最合适的稳压剂兼Ｃ源，效果比单用蔗糖或山梨醇好．原生质体起源的愈伤组织，只有转入以３％或５％的山梨醇为Ｃ源的培养基中，才能分化茎原基并进而再生植株；转入含蔗糖的培养基，不能分化，继代数次，愈伤组织褐化．分化茎原基的愈伤组织与一般愈伤组织和褐化愈伤组织相比，其山梨醇含量和山梨醇脱氢酶的比活力，均显著升高．且愈伤组织内出现了一些结构变化的区域，这些区域的细胞没有中央液泡，只有小液泡，细胞器非常丰富．这种愈伤组织的显微结构特点与上述山梨醇代谢活跃相平行，共同构成茎原基分化的基础．     

川西草地高亚麻酸植物播娘蒿的初步研究

为了掌握川西草原野生播娘蒿的生物学特性和经济价值，将川西地区的野生播娘蒿种子收集后在成都栽培观察，初步掌握了其生物学特性和生产价值，通过比较选出红原产播蒿的种子产量达到１１５９．５ｋｇ／ｈｍ＾２，含油量为４４．２０％，其油分中亚麻酸含量为４０．９０％，亚麻的理论产量可达２０９．４７ｋｇ／ｈｍ＾２，高寒草原产的播娘蒿引入低海拔地区种植可以秋播，幼细越冬生长正常，生育期为２１０ｄ，在高海拔区地区播娘蒿     

肉用仔鸡日粮钙、磷、锰、锌和维生素D_3水平的主成分分析

应用５因素２次回归几乎正交旋转组合设计，运用主成分分析方法对４３２只ＡｒｂｏｒＡｃｒｅｓ公雏（３６组，１２只／组）的日粮钙、磷、锰、锌、ＶＤ３５因素与９项检测指标之间的关系进行研究。相关性分析和主成分分析结果表明：日粮钙水平与肉仔鸡１４日龄体重、日粮钙和锌水平与肝脏锌沉积、日粮磷水平与ＡＫＰ活性、胫骨锌沉积均呈显著负相关；日粮锌水平与肉仔鸡体重、胫骨锌沉积呈强正相关。分析累计方差贡献率８６％以上的１１个主成分表达式结果：日粮钙水平阻碍肉仔鸡早期生长，使组织锌沉积降低；日粮钙与磷、锰与锌、ＶＤ３与磷之间的互作在不同程度上影响肉仔鸡组织、血液和骨骼锌沉积。衡量日粮钙供给状况的是第１、９、１０主成分因子；衡量日粮钙、磷供给状况的是第３、８、１１主成分因子；衡量日粮锰与钙供给状况的是第４主成分因子；衡量日粮锌与钙供给状况的是第５主成分因子。     

基于参数化零件图的二维装配图修改技术

在综合考虑参数化零件图的复制和对装配图中零件图的计算机识别的基础上，构造了装配图的参数化修改模型，结合基于深度测试的装配消隐算法阐述了一种基于参数化零件图的二维装配图修改技术。实际应用结果表明，由此技术生成的装配图可进行参数化尺寸驱动修改，并且在装配图的构建过程中也可动态尺寸驱动修改零件图，从而使装配图的生成和修改变得方便和直观。     

直流电源对汽车用继电器调整的影响

汽车用继电器的触点动作电压值随作用的直流电源不同而发生较大变化。由于实际调试中对该问题没有引起足够的重视,以致影响了汽车上其它电气设备的正常工作,增加了汽车电气系统的故障,降低了使用寿命。本文通过理论与实际研究,指出了不同直流电源对车用继电器调整时产生的影响,并指出了调试中应注意的问题。