白羊草叶片和根系干旱胁迫下microRNAs差异表达分析

为了探索干旱胁迫下白羊草miRNAs的组织特异性,本研究在干旱胁迫下白羊草（Bothriochloa ischaemum）转录组数据的基础上,采用Illumina测序技术和生物信息学方法,对干旱胁迫和正常生长条件下白羊草苗期叶片和根系miRNAs（microRNAs）进行鉴定和表达分析研究。结果从4个库中鉴定出白羊草中有属于20个家族的79个已知miRNAs和92个新miRNAs。干旱胁迫后叶片和根系中差异表达的miRNAs分别有65个（上调28和下调37）和27个（上调15和下调12）。响应干旱胁迫的主要miRNAs为miR156,miR164,miR166,miR169,miR172,miR396,miR398,miR408,miR528。对这些miRNAs预测的靶基因进行GO生物功能和KEGG代谢通路富集分析表明,植物激素信号转导是叶片和根系响应干旱胁迫共同富集的主要代谢通路,而黄酮类化合物生物合成则是干旱胁迫下叶片富集的最主要代谢通路。     

土壤干旱对刺槐幼苗水分生理的影响

对不同土壤干旱条件下刺槐幼苗水分生理和生长指标进行了初步研究。结果表明:蒸腾速率、叶水势、叶片相对含水率、耗水量和耗水系数均随土壤水分的减少而呈降低趋势。同时,对试验中存在的问题进行了探讨。     

乙烯利对干旱条件下多年生黑麦草生理指标的影响

本研究以'Neruda','Accent','MS','AST'4个品种多年生黑麦草(Lolium perenne L.)为试验材料,研究叶片喷施乙烯利对多年生黑麦草耐旱性的影响.结果表明,喷施乙烯利后干旱处理10 d时,'Neruda'、'MS'和'AST'叶片相对含水量显著提高,所有品种电解质渗透率均下降,'Ner...     

Correlation between corneal sensitivity and quantity of reflex tearing in cows,horses, goats,sheep, dogs,cats, rabbits,and guinea pigs

Objective Guinea pigs have a very low threshold of corneal sensitivity and at the same time nearly no reflex tearing compared to dogs, cats, and horses. The question arose whether there is a general correlation between corneal sensitivity and the quantity of reflex tearing. Animals studied Totally 160 animals of 8 different species (20 animals per species) were investigated. Procedures The corneal touch threshold (CTT) was measured with a Cochet–Bonnet esthesiometer. The palpebral fissure length (PFL) was measured with a calliper ruler. The Schirmer tear test (STT) was modified by adapting the width of the STT strip to the PFL of every species. For the STT II, 0.4% oxybuprocaine was applied. Results Corneal touch threshold: Cows (1.67 g/mm²), horses (1.23 g/mm²), sheep (1.13 g/mm²), goats (1.44 g/mm²), dogs (2.16 g/mm²), and cats (1.33 g/mm²) show similar CTT values. In contrast, rabbits (6.21 g/mm²) and guinea pigs (7.75 g/mm²) show a significantly lower CTT. Tear Production Difference STT I ? STT II: Rabbits have the greatest decline in tear production with 38.4%, followed by sheep (33.3%), dogs (31.1%), cats (24.7%), cows (23.7%), horses (18.0%), and goats (14.0%). Guinea pigs have no decline, but a slight increase of ?16.0%. Correlation CTT and STT II ? STT I Difference: Pearson’s correlation coefficient shows a small, but significant correlation. The coefficient of determination can only forecast a value with 7.1% certainty. Conclusions The high variance and low reproducibility of results suggest that the measuring devices are inappropriate to assess the evaluated parameters. Therefore, no assured correlation between the corneal sensitivity and the quantity of reflex tearing could be found.     

Pharmacokinetic and pharmacodynamic modelling of intravenous,intramuscular and subcutaneous buprenorphine in conscious cats

ObjectiveTo describe simultaneous pharmacokinetics (PK) and thermal antinociception after intravenous (IV), intramuscular (IM) and subcutaneous (SC) buprenorphine in cats.Study designRandomized, prospective, blinded, three period crossover experiment.AnimalsSix healthy adult cats weighing 4.1 ± 0.5 kg.MethodsBuprenorphine (0.02 mg kg^?1) was administered IV, IM or SC. Thermal threshold (TT) testing and blood collection were conducted simultaneously at baseline and at predetermined time points up to 24 hours after administration. Buprenorphine plasma concentrations were determined by liquid chromatography tandem mass spectrometry. TT was analyzed using anova (p < 0.05). A pharmacokinetic-pharmacodynamic (PK-PD) model of the IV data was described using a model combining biophase equilibration and receptor association-dissociation kinetics.ResultsTT increased above baseline from 15 to 480 minutes and at 30 and 60 minutes after IV and IM administration, respectively (p < 0.05). Maximum increase in TT (mean ± SD) was 9.3 ± 4.9 °C at 60 minutes (IV), 4.6 ± 2.8 °C at 45 minutes (IM) and 1.9 ± 1.9 °C at 60 minutes (SC). TT was significantly higher at 15, 60, 120 and 180 minutes, and at 15, 30, 45, 60 and 120 minutes after IV administration compared to IM and SC, respectively. IV and IM buprenorphine concentration-time data decreased curvilinearly. SC PK could not be modeled due to erratic absorption and disposition. IV buprenorphine disposition was similar to published data. The PK-PD model showed an onset delay mainly attributable to slow biophase equilibration (t_1/2k_e0 = 47.4 minutes) and receptor binding (k_on = 0.011 mL ng^?1 minute^?1). Persistence of thermal antinociception was due to slow receptor dissociation (t_1/2k_off = 18.2 minutes).Conclusions and clinical relevanceIV and IM data followed classical disposition and elimination in most cats. Plasma concentrations after IV administration were associated with antinociceptive effect in a PK-PD model including negative hysteresis. At the doses administered, the IV route should be preferred over the IM and SC routes when buprenorphine is administered to cats.     

白刺夜蛾防治指标的研究

研究白刺夜蛾幼虫的食量和防治指标。结果表明,幼虫可分为5龄,各龄幼虫的日食量依次为4.81、12.39、37.56、130.68和483.25mg/头,幼虫期总食量2453.58mg/头。根据食量测定,研制的防治指标为39.7头/m²,经济允许损失水平为12.5%。     

三种禾草萌发期抗旱性研究

采用蒸馏水及浓度为5%、10%、15%、20%和25%的PEG溶液处理梭罗草、青海草地早熟禾、垂穗披碱草种子,测定其发芽率、苗长、胚根/胚芽比值,以研究PEG对种子萌发的影响。结果显示:PEG浓度为5%时,青海草地早熟禾的相对发芽率出现小幅上升趋势,垂穗披碱草和梭罗草均呈下降趋势;不同处理对胚根/胚芽比值和苗长均有影响,梭罗草受影响小。因此这三种牧草在萌发期抗旱性依次为:梭罗草、青海草地早熟禾、垂穗披碱草。     

4种多年生禾草苗期抗旱性的比较研究

采用盆栽育苗法,在4种多年生禾本科牧草苗期连续干旱胁迫下测定植株的叶片相对含水量、质膜相对透 性、游离脯氨酸含量、丙二醛含量4个抗旱生理指标,以综合评价4种多年生禾草的抗旱性能。研究结果表明:供试材料 在连续干旱胁迫下,叶片相对含水量呈下降趋势,质膜相对透性、游离脯氨酸含量及丙二醛含量都有所增加。综合分析 结果,4种多年生禾草的苗期抗旱性按照从强到弱的顺序依次为无芒雀麦>苇状羊茅≥老芒麦>披碱草。     

干旱胁迫对香根草生长及光合生理主要特征的影响

对干旱、半水淹和对照(正常灌水)等三种处理香根草在30d后的生长状况,以及退水、复水40d后三种处理香根草对光合有效辐射(PAR)增强的光合生理主要特征进行研究。结果表明:复水、退水后,干旱、半水淹处理香根草Pn、Tr和WUE均已恢复正常,说明香根草具有相当强的抗旱耐涝能力。