奶牛繁殖疾病的调控

本文综述了奶牛繁殖疾病的发病原因和调控措施，分析认为奶牛的营养状况是影响奶牛繁殖力的重要因素。理想的奶牛管理应做到整个泌乳期始终监测奶牛的体况和奶牛日粮中微量元素的维生素的含量，避免营养素的不平衡而引发的奶牛繁殖障碍，同时应避免奶牛过肥或过瘦。适当补充某些维生素和矿物质十分重要。     

日光温室内外金太阳杏光合特性的比较研究

为了探明杏对设施栽培的生理反应,对日光温室内外金太阳杏光合特性进行了比较研究。结果表明,日光温室栽培条件下,金太阳杏单位重量叶片的叶绿素含量增加;光(CO2)饱和点和光(CO2)补偿点降低鸦露地晴天净光合速率Pn日变化呈明显的双峰曲线,温室内也呈双峰线,但双峰出现原因不同。并且研究了影响光合作用的主要生态因子及变化规律,发现净光合速率与胞间CO2浓度、蒸腾作用、气温、叶温、光合有效辐射等因子相关。     

and laminin on adhesion and proliferation of human hepatocellular carcinoma cell

AIM:To explore the effects of PMA(phorbol-12-myristate-13-acetate, a tumor promoter, mimicking the action of diacylglycerol on PKC)and laminin on the adhesion and the proliferation of human hepatocellular carcinoma cells, and provide a new clue to liver cancer treatment.METHODS:Human hepatocellular carcinoma cell line(BEL-7402)was used to identify the endogenous laminin and protein kinase C-α(PKC-α) expression, and the effects of laminin and PMA on the adhesion and the proliferation were also investigatedin vitro.RESULTS:By the effect of exogenous laminin, human hepatocellular carcinoma cell (BEL-7402) possessed endogenous laminin expression and increased the adhesion and the proliferation, which was showed the synergistic action by the effect of PMA in combination. By the action of PMA alone, the proliferation and the PKC-α expression increased by exogenous laminin were decreased, and the adhesion and the endogenous laminin expression were increased.CONCLUSIONS:The finding suggested that the adhesion and the proliferation of human hepatocellular carcinoma cell were closely related to the effects of endogenous or exogenous laminin, which were associated with cPKC-α activity. Therefore, the application of anti-laminin antibody in combination with PKC antagonist might be a new clue to find out the therapy for liver cancer.     

Changes of intracellular potassium activity and membrane potential in guinea pig ventricular myocardium during superfusion with low sodium solutions and effects of low pH

AIM:To investigate the changes in intracellular potassium activity(aⁱK) and membrane potential(V_m) induced by low external sodium infusion (Low [Na]_o) and to detect the mechanisms involved and the relationship between aⁱK and V_m. METHODS:aⁱK and V_m were measured in infusion with different sodium concentrations using methods of convenient and ion selective microelectrodes in guinea pig ventricular myocardium. RESULTS:Low [Na]_o resulted in a decrease in aⁱK and an increase in V_m in a Na⁺ concentration-dependent manner.At the same time,contraction and resting potential increased, and action potential duration decreased markedly,but action potential amplitude was not affected. A change of the pH from 7.4 to 7.0 in low [Na]_o solution reduced the decrease in aⁱK, but did not affect the increase in V_m.CONCLUSION:A better linear relationship appeared between the changes in aⁱk and [Na]_o or in V_m and [Na]_o,while during each low [Na]_o the change in both aⁱK or V_m may reach a new balance level.     

Chloride channels of platelets

Chloride channels distribute widely in the body, and participate in many physiological actions and regulatory processes. Based on their physiological roles and molecular structures, six kinds of chloride channels have been identified: (1) The chloride channels family; (2) Cystic fibrosis transmembrane conductance regulator; (3) Swelling-activated chloride channels; (4) Calcium-activated chloride channels; (5) The p64 (CLIC) gene family; (6) γ-aminobutyric acid and glycine receptors. The chloride channels do exist in platelets, and their appearances are dependent on the presence of intracellular calcium. Blocking agents of chloride channels inhibit the thrombin-activated platelet aggregation and the elevation of the intracellular calcium concentration in a dose-dependent manner. It is suggested that chloride channels play a role in the activation of platelets. In addition, chloride channels act on both the cell volume regulation and the intracellular pH regulation in platelets.     

Effects of fosinopril,captopril and valsartan on the expressionof tissue factor in human monocytes

AIM: To investigate the effects of angiotensin-converting enzyme inhibitors (ACEI), fosinopril, captopril and angiotensin II AT₁ antagonists, valsartan on tissue factor (TF) expression on monocytes induced by lipopolysaccharide (LPS). METHODS: Mononuclear leukocytes from normal delivered female umbilical veins were incubated with bacterial LPS in presence or absence of different ACE inhibitors .At the end of incubation, the cells were disrupted by 3 freeze-thaw cycles. TF procoagulant activity was assessed by a one-stage clotting assay. RT-PCR was used to check TF mRNA expression, and GAPDH mRNA was used for parallel assay. RESULTS and CONCLUSION: The results showed that increased expression of TF mRNA induced by LPS was inhibited by fosinopril, captopril and valsartan, respectively, and the procoagualant activity of monocytes was also reduced.     

猪卵泡卵母细胞体外成熟与冷冻保存

研究了激素、猪卵泡液、不同类型血清对猪卵泡卵母细胞体外成熟的影响 ;比较了卵泡直径小于 2 mm、2～ 5 mm和大于 5 mm的卵母细胞体外成熟能力的差异 ,并对不同发育阶段猪卵母细胞的冷冻保存进行了研究。结果表明 :猪卵母细胞体外培养 4 8h时 ,培养的前 2 4 h培养液中加入激素 ,后 2 4 h去掉激素 ,卵母细胞的 A级成熟率 (5 1.73% )和总成熟率 (83.2 5 % )最高 ,极显著高于前 2 4 h不加激素 ,后 2 4 h添加激素培养的成熟率 (P<0 .0 1) ;也显著高于不含激素的培养液连续培养 4 8h的成熟率 (P<0 .0 5 ) ;但与添加激素连续培养 4 8h的成熟率差异不显著 (P>0 .0 5 )。在体外成熟培养液中 ,添加 10 % (体积分数 ) ECS的成熟率 (72 .86 % )显著高于添加 10 % (体积分数 ) NCS的成熟率(6 2 .2 1% ) (P<0 .0 5 ) ,而添加 10 % p FF则抑制卵母细胞的体外成熟。随着卵泡直径的增大 ,卵母细胞体外成熟能力逐渐增强。采用程序冷冻保存方法 ,成熟卵母细胞的成活率 (35 .5 9% )显著高于培养前 (2 4 .6 4 % )和培养 2 4 h(2 3.36 % ) (P<0 .0 5 )。培养 2 4 h(77.2 2 % )和培养成熟 (72 .81% )的卵母细胞解冻后的形态完整率均显著高于培养前(5 3.2 4 % ) (P<0 .0 5 )     

不同生长型桃树叶片形态解剖结构及其与营养生长的关系

对6种不同生长型桃树的营养生长特征和叶片形态、解剖结构进行了研究,并对营养生长与叶片解剖结构的关系进行了分析.结果表明:不同生长型间在树体高度、枝条节间长度等方面存在显著差异.从树体高度看,矮化型<紧凑型<半矮化型<垂枝型<普通型;紧凑型的萌芽率(86.1%)和成枝率(78.1%)在所有类型中均是最高的,平均每个母枝可形成近10个中长枝,远高于其它类型;在叶片结构特征方面,普通型的叶片干物质含量最高,其后依次为半矮化型,垂枝型,紧凑型和矮化型,相关分析表明,干物质含量与成枝率之外的其它生长参数均呈正相关,而单位叶面积鲜重与成枝率之外的其它生长参数呈负相关;在解剖结构上,普通型叶片最厚,为194.5 μm,紧凑型叶片最薄,叶片组织较疏松;普通型的栅海比(栅栏组织厚度/海绵组织厚度)最小,而矮化型最高,栅海比与树体高度成负相关,与一次枝长呈显著负相关(r＝-0.986**).叶背气孔密度分布范围为1 mm2 234.1～393.5个,垂枝型最高,半矮化型最低,气孔密度与一次枝粗的相关系数达到极显著水平(r＝-0.944**),而与枝条长度和节间长度的相关系数则较低.     

滇中云南松火烧后第一年死亡预测模型研建

根据云南松（Pinus yunnanensis）的耐火性和受火害后遗留下来容易获取的信息建立火烧死亡预测模型,可以为林火熄灭后短时间内进行火灾损失评估、迹地植被恢复方案设计等提供理论依据。在安宁2006年“3&#183;29”森林火灾火烧迹地上对发生过树冠火的云南松死活情况、火烧状况进行了调查,测定了286株云南松的树高、胸径、胸高处树皮平均厚度、树干烧黑高度、树干表面圆周烧黑宽度、树干基部树皮平均炭化深度,记录了受害木的流脂状况。以树高、胸径、胸高处树皮平均厚度、树干纵向最大烧黑率、树干弦向最大烧黑率、树干基部树皮径向平均炭化率和流脂状况7个指标作为预测依据,运用学习向量量化人工神经网络建立滇中云南松火烧死亡预测模型,并用C^＋＋实现了该模型。经检验,该模型的平均准确率达81．12％,对死树的预测正确率达93．72％,对活树的预测正确率达48．10％,可以用于云南松火烧后第一年死亡的判别和预测。     

杂交晚稻机插不同播量条件下育插秧试验研究

以杂交晚稻“江四优992”为供试材料,进行了不同播量软盘育秧机插与常规水育秧手插的对比试验。结果表明：机插软盘育秧随播种量增加,漏插率降低,以90～100g芽谷／盘为最佳播量;机插秧虽然前期分蘖稍慢,但后期具有分蘖稳健、无效分蘖少、成穗率高的特点;机插稻的全生育期比手插稻延长2～3d;与手插稻相比,机插稻的穗粒结构合理,穗粒数多,产量高,平均增产10．2％。