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青霉素对老化茎用莴苣种子发芽及幼苗生长的影响 总被引：2，自引：0，他引：2
本实验研究了100mg/L～500mg/L青霉素溶液对常规和老化茎用莴苣种子发芽及幼苗生长的影响。方差分析结果表明：不同浓度的青霉素溶液对茎用莴苣种子的发芽指数、活力指数和幼苗鲜干重的影响达到极显著水平，对茎用莴苣种子发芽和幼苗生长有促进作用。同时也表明不同浓度青霉素对茎用莴苣老化种子活力恢复和提高有改进作用。经过400mg/L青霉素处理的老化种子活力指数是未经处理的老化种子的10．44倍，种子老化严重抑制了种子活力，而较低浓度的青霉素处理可以修复老化对种子的损伤。青霉素与低温冷处理（5℃）的协同作用对茎用莴苣种子的发芽和幼苗生长的促进作用是极显著的。 相似文献
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A Grinberg N Lopez-Villalobos K Lawrence M Nulsen 《New Zealand veterinary journal》2013,61(5):332-335
AIM: To gauge how well prior laboratory test results predict in vitro penicillin resistance of Staphylococcus aureus isolates from dairy cows with mastitis. METHODS: Population-based data on the farm of origin (n=79), genotype based on pulsed-field gel electrophoresis (PFGE) results, and the penicillin-resistance status of Staph. aureus isolates (n=115) from milk samples collected from dairy cows with mastitis submitted to two diagnostic laboratories over a 6-month period were used. Data were mined stochastically using the all-possible-pairs method, binomial modelling and bootstrap simulation, to test whether prior test results enhance the accuracy of prediction of penicillin resistance on farms. RESULTS: Of all Staph. aureus isolates tested, 38% were penicillin resistant. A significant aggregation of penicillin-resistance status was evident within farms. The probability of random pairs of isolates from the same farm having the same penicillin-resistance status was 76%, compared with 53% for random pairings of samples across all farms. Thus, the resistance status of randomly selected isolates was 1.43 times more likely to correctly predict the status of other isolates from the same farm than the random population pairwise concordance probability (p=0.011). This effect was likely due to the clonal relationship of isolates within farms, as the predictive fraction attributable to prior test results was close to nil when the effect of within-farm clonal infections was withdrawn from the model. CONCLUSIONS: Knowledge of the penicillin-resistance status of a prior Staph. aureus isolate significantly enhanced the predictive capability of other isolates from the same farm. In the time and space frame of this study, clinicians using previous information from a farm would have more accurately predicted the penicillin-resistance status of an isolate than they would by chance alone on farms infected with clonal Staph. aureus isolates, but not on farms infected with highly genetically heterogeneous bacterial strains. 相似文献
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本文报道猪链球菌病对肌肉注射多剂量青霉素G钾（15000IU/kg,每隔12h肌注1次,连续给药5次）在猪体内血清浓度和药物动力学影响的研究。通过皮下接种9-10亿个菌落形成单位的猪链球菌,人工诱发猪链球菌病。发病猪给药前的直肠体温比正常时至少升高1.5℃,第一次给药后8h内感染猪的直肠温度仍显著升高（P＜0.05或0.01）,并可观察到其他临床症状。给药后的不同时间间隔从前腔静脉采血,用微生物法测定血清青霉素G的浓度。病猪第一次给药和第五次给药后的血药浓度--时间数据用MCPKP计算机程序处理,均符合一级吸收二室开放模型。病猪第一次及第五次给药的主要药物动力学参数（平均值±标准差）分别是：t#-(1/2α)0.66±0.15及0.59±0.17h;t#-(1/2β)1.87±0.55及2.18±0.97h;t#-(1/2ka)0.35±0.05及0.20±0.09h（P＜0.05）;t#-(max)0.71±0.10及0.48±0.11h（P＜0.05）;C#-(max)7.48±0.97及9.04±0.62IU/ml（P＜0.01）;AUC16.84±1.64及16.42±1.65I
U·h/ml,Tcp(ther)11.72±3.33及12.41±3.62h;笔者对引起病猪第一次及第五次给药的某些药物动力学参数有显著差异的原因进行了探讨。 相似文献
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[目的]为西葫芦的高产栽培提供理论依据。[方法]选用已经保存4年的西葫芦品种西葫芦1号种子为供试材料,用不同浓度的青霉素、多效唑进行浸种处理,并采用青霉素200 mg/L分别和不同浓度多效唑混配处理,以清水为对照,进行室内发芽和田间种植试验,研究青霉素和多效唑对西葫芦陈种子发芽及田间成苗的影响。[结果]用青霉素200 mg/L、多效唑500 mg/L处理对西葫芦种子发芽率、幼苗根系活力、叶片叶绿素含量和田间成苗效果较好,二者复配青霉素200 mg/L＋多效唑500 mg/L处理效果最好,与对照差异达到显著水平。[结论]选择适宜浓度的青霉素、多效唑以及二者复配,可促进西葫芦种子新陈代谢系统的修复和恢复,使幼苗达到正常常规种子生长的指标,建议在农业生产实践中应用。 相似文献
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青霉素对板栗花性别分化和生理特性的影响 总被引：13，自引：0，他引：13
研究不同浓度青霉素对板粟花性别分化及其部分形态特征和生理特性的调节效应，结果表明，100mgL’青霉索处理可显著促迸板栗雌花分化和新梢加粗生长，抑制雄花分化和新梢伸长生长，调整雄花雌花数比，提高树体氮代谢水平和光合作用强度。而300和500mgL’青霉素处理虽也具促雌抑雄效应，但同时也刺激新梢伸长生长，对提高树体氮代谢 水平、光合作用强度和新梢加粗生长效应不明显。6—BA和CCC对青霉索有一定的协同或抑制作用。 相似文献
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以保存4 a的青春38小麦种子为供试材料，用不同质量浓度聚乙二醇、青霉素、甲基托布津、高锰酸钾、双氧水进行浸种处理。结果表明，以200 mg/L聚乙二醇、200 mg/L青霉素、1.5 g/L甲基托布津、10 g/L高锰酸钾及双氧水浸泡10 min处理种子，其发芽率、幼苗根系活力、叶片叶绿素含量和田间成苗效果最好，与CK差异达到显著水平（P<0.05）。说明一定质量浓度和时间的药剂浸种处理促进小麦陈种子新陈代谢系统的修复和恢复,充分利用胚中贮存的营养物质,使幼苗达到与正常常规种子生长的指标，建议在农业生产实践中应用。 相似文献
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Brucella spp. L-forms have been proposed to be stationary phase organisms in the evolution of new variants and enduring entities in the host in complicated cases of brucellosis and during latent brucellosis. In vitro formation of Brucella L-forms has been achieved by treating the cells with sub-lethal doses of penicillin. Interestingly, Brucella spp. have classified during the evolution into two groups, penicillin susceptible or penicillin resistant, yet both types grow on 20 μg/ml of methicillin. Strains proven susceptible to penicillin grew in the presence of methicillin as L-forms as demonstrated by light and electron microscopy. In addition, the B. melitensis vaccine strain Rev.1, a penicillin susceptible organism, responded to sheep serum by development of L-form-like structures unlike wild type, strain 16M. The two strains grew normally in sheep macrophages. We propose, for the first time, a model that associates Brucella pathogenicity with the structure and activity of two of their penicillin binding proteins (PBPs). According to the model, PBP1 has evolved as the major cell wall synthesizing enzyme of the genus, capable of responding to host serum growth factor(s) necessary for Brucella survival in the host. This property is associated with high avidity to β-lactam antibiotics. PBP2 complements the activity of PBP1. New β-lactam antibiotics and improved vaccines might be developed based on this property. 相似文献