盐胁迫对麻黄愈伤组织生理生化指标的影响

研究了中麻黄愈伤组织在0.1%(A)、0.2%(B)0、.4%(C)、0.6%(D)0、.8%(E)、1.0%(F)NaCl处理下,生长状态、质膜透性、叶绿素、脯氨酸、丙二醛(MDA)及可溶性糖含量的变化.结果表明:0.2%以下的盐浓度对愈伤组织的增殖影响不大,其耐盐的极限值在0.6%-0.8%.随NaCl浓度的增大和胁迫时间的延长,叶绿素含量总体呈降低趋势;膜透性增强;脯氨酸含量在前期(10 d)和中期(20 d)变化不明显,胁迫后期(30 d)明显增加;MDA含量在前期、中期增加,后期处理A、B、C、D的MDA含量降低,但在0.8%和1.0%盐浓度下继续升高;可溶性糖含量总体均比对照有所增加,但在不同时期及不同处理下积累量有所不同.     

柔嫩艾美耳球虫敏感株与抗药株子孢子膜脂流动性的检测

建立了应用荧光探针1,6-二苯基-1,3,5-己三烯(DPH)测定柔嫩艾美耳球虫子孢子膜脂流动性的方法。对柔嫩艾美耳球虫(Eimeria tenella)的敏感株与各种抗药株共13个球虫株的子孢子膜脂流动性进行测定。结果表明,敏感株的膜脂流动性大,抗药株膜脂流动性小(P0.01,呈极显著相关)。由此可见,虫株对药物的敏感性可能与膜脂流动性有关,膜脂流动性的检测结果可作为判别柔嫩艾美耳球虫对离子载体类抗球虫药物敏感性或抗药性的指标之一。     

超临界CO_2流体的夹带剂对木材渗透性的影响

以甲醇、乙醇、苯—乙醇为夹带剂,考察超临界CO2流体处理对福建产马尾松、檫木渗透性及失重率的影响。结果表明,试材经超临界CO2流体处理后,渗透性得到了较大地改善,夹带剂的使用更有利于木材渗透性的提高,在3种夹带剂中,以苯—乙醇效果最佳,马尾松、檫木的渗透性变化率最高分别可达504%和339%。     

甘蔗抗旱性与叶片某些生理、生化性状的关系

在水分胁迫条件下测定了抗旱性不同的 3个甘蔗品种的叶片脯氨酸含量、叶细胞质膜透性和叶片丙二醛含量。结果表明,不同抗旱性品种间脯氨酸含量和质膜透性存在极显著差异,都表现出品种的抗旱性越强脯氨酸含量和质膜透性越低的趋势,而丙二醛含量没有表现出品种间的差异和一致的变化趋势。因此,可以认为叶片脯氨酸含量和质膜透性可作为甘蔗抗旱性育种的选择指标。     

干旱胁迫对苣荬菜抗氧化酶和渗透调节物质的影响

为探究野生苣荬菜(Sonchus brachyotus DC.)抗旱能力,用盆栽控制浇水模拟干旱的方法,研究了不同程度干旱胁迫下苣卖菜幼苗对干旱胁迫的响应。结果表明:随着干旱胁迫程度的加深,苣荬菜叶片相对含水量逐渐降低,质膜透性、丙二醛(MDA)含量升高,轻度干旱胁迫下以上3种指标与对照相比差异不显著(P<0.05)。超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性升高,SOD,POD活性在重度干旱条件下稍有下降,但仍高于对照。可溶性有机渗透调节物质脯氨酸、可溶性糖含量、可溶性蛋白含量持续上升,尤以脯氨酸上升幅度最大,重度干旱时达对照的11.06倍,表明苣荬菜有一定的抗旱能力。     

猪肺炎支原体MY-99株膜蛋白SDS-PAGE分析及免疫原性研究

采用TritonX 100和KI两种方法分步提取猪肺炎支原体MY 99株膜蛋白,结果显示,0 6mol/LKI溶液具有较好的溶解蛋白质的作用。经SDS PAGE和免疫印迹分析表明,膜蛋白的分子量在14—100KD之间,其中36KD和64KD为保护性抗原。研究还发现,猪肺炎支原体MY 99株膜蛋白具有非特异性和特异性的致有丝分裂作用,对T淋巴细胞刺激的转化率分别为10 08%和24 75%(P<0 05),并能诱导机体产生高效价的抗体,免疫后7d、14d和21d抗体效价达1∶23.50、1∶26.33和1∶27.83。     

Adaptive Acquisition of Novobiocin Resistance in Pasteurella multocida Strains of Avian Origin

Naturally occurring strains of Pasteurella multocida are atypically susceptible to hydrophobic antibiotics such as novobiocin, despite their Gram-negative cell envelope ultrastructure. Four strains adaptively resistant to 1000 g/ml of novobiocin were obtained by sequentially subculturing cell surface hydrophobic variants of avian origin in the presence of increasing antibiotic concentrations. Adaptive novobiocin resistance was accompanied in all cases by the concomitant acquisition of resistance to coumermycin, a hydrophobic antibiotic possessing the same mechanism of action, but not to the functionally disparate hydrophobic antibiotic rifamycin. The acquisition of resistance was not accompanied by alterations in the lipid composition of the cell envelope. Subsequent growth of adaptively resistant strains in the absence of novobiocin did not result in the restoration of susceptibility to either novobiocin or coumermycin. Acquisition of adaptive resistance in encapsulated parental strains resulted in an inability to synthesize capsular material and enhanced cell surface hydrophobicity; however, parental encapsulation and decreased cell surface hydrophobicity were restored upon removal of novobiocin. These data suggest that acquisition of adaptive resistance to novobiocin conferred in this manner is the result of a stable genetic event affecting the mechanistic target of both novobiocin and coumermycin rather than a physiological adaptation involving outer membrane impermeability.     

猪脂肪沉积相关的生化特征研究

以遗传瘦肉型的斯格猪和长白猪以及遗传脂肪型的通城猪和太湖猪为动物样本，分析了血清中激素敏感脂酶，肌肉组织中氨基酸组成、含量和克分子比，分离纯化了肌细胞和脂肪细胞质和膜，并对其膜蛋白进行了SDS－PAGE比较分析。结果表明，脂肪型的通城猪血中激素敏感脂酶活性比瘦肉型的长白猪高近3倍，2猪种中雌雄差异不显著。脂肪型的通城猪与太湖猪肌细胞蛋白质中的氨工酸组成及含量十分相似，瘦肉型的斯格和长白猪的氨基酸含量却显著地高于脂肪型的通城和太湖猪。氨基酸组分中，瘦肉型猪的3种碱性氨基酸（Lys、Arg和His）、2种典型的疏水氨基酸（Ｌeu和lle)、易形成疏水核的苯丙氨酸以及形成二硫键的半胱氨酸均显著地高于脂肪型，这与瘦肉型猪蛋白质的溶解性能较差相关。蛋白质的SDS－PAGE分析发现，脂肪型猪肌细胞质中存在一种一约44．7kDa，与脂肪沉积相关的蛋白质。脂肪细胞膜中的94kDa蛋白也显示也脂肪沉积的遗传特征相关，另外，脂肪型的通城猪性成熟前后肌细胞膜上存在蛋白质组分差异。     

Evaluation of the efficiency of irrigation methods on the growth and survival of tree seedlings in an arid climate

Scarce and scattered precipitation in arid regions is detrimental for newly planted seedlings. It is essential to provide required water storage for seedlings in restoration projects in the first year of their establishment. The subsurface irrigation can be much more effective than the surface irrigation because of the regulation of water availability and reduction in water evaporation. We studied the effect of surface and subsurface irrigation methods on the growth and survival of four common tree species including heaven tree(Ailanthus altissima(Mill.) Swingle), China berry(Melia azedarach L.), white mulberry(Morus alba L.), and black locust(Robinia pseudoacacia L.) by installing underground clay reservoirs with different permeabilities in Isfahan City, Iran. Different amounts of animal manure and wheat straw were mixed with clay fraction and cooked in a pottery kiln at 900°C to produce reservoirs with different permeabilities. The experimental treatments consisting of irrigation and tree species were considered with a factorial arrangement in a completely randomized design with three replications in 2016 and 2017. Leaf water potential of seedlings, which is indirectly related to drought resistance, was measured by a portable pressure chamber. The results showed that saplings height, basal diameter, number of leaves, chlorophyll content and stomatal conductance were significantly(P0.05) higher in the subsurface irrigation with low permeability than in the surface irrigation, but the number of branches of the studied species were not significantly(P0.05) affected by the irrigation methods and different permeabilities of clay reservoirs. The clay reservoirs with low and medium permeabilities constantly provide better conditions for plant growth, and water with lower pressure and longer time intervals to the plant roots as compared with the reservoirs with high permeability. Analysis of variance of the data showed that year and interaction between year and permeability of reservoir had significant effects(P0.05) on all growth parameters, except for the chlorophyll content. In addition, the highest percentage of survival was 100% associated with the subsurface irrigation and the control treatment had the lowest survival percentages of 60%, 70%, 80% and 100% for M. alba, M. azedarach, A. altissima and R. pseudoacacia, respectively. Finally, the values of leaf water potential showed that R. pseudoacacia was the most drought resistant species.     

Mechanical control effect of hard tectonic structure on coal seam gas flow

To analyze the controlling effect of hard tectonic structure to gas flow at the coal seam heading face, two physical mechanical models are established, normal coal seam driving and hard body embedding coal seam driving. Then according to the above two numerical models, it numerically analyzes the stress distribution characteristics, the coal seam permeability change and the gas flow rule at the coal seam heading face by using rock fracture finite element software RFPA 2D-GAS with solid-gas coupling analysis module, and carries on comprehensive comparative analysis. Finally, combining with two ordinary cases from product field, it verifies the conclusion from the numerical simulation that the concentrated stress influences the coal seam permeability and controls the gas flow. The results show that: the concentrated stress at the coal heading face with hard tectonic structure is like a “closed gate”, as it makes the coal seam permeability obviously lower and blocks the normal migration of gas in the vicinity to the freedom space. In order to eliminate the gas abnormal emission threat at the high gassy coal seam heading face, stress and gas relief measures must be taken to rip the “closed gate” and effectively remove the concentrated stress to provide safe releasing channels for the blocked gas.