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11.
选用巴斯德毕赤酵母(Pichia pastoris)系统表达特异性抗速灭威单链抗体(scFv)基因,以为速灭威特异性抗体的大量制备奠定基础。设计引物扩增阳性克隆scFv基因,亚克隆至表达载体pPICZαC,获得重组酵母表达质粒pPICZαC-scFv,线性化pPICZαC-scFv并高效电转P.pastoris(X-33),对转化子进行抗性梯度筛选得到一株高效表达的X-33-Pp-SMW-12-6菌株。对获得的菌株先后进行表达条件的优化、优化条件下的诱导表达及单链抗体性质研究。结果表明:P.pastoris-scFv的质量接近其亲本E.coli-scFv的质量,X-33-Pp-SMW12-6在优化条件下的表达产量达28mg/L,比未优化前的产量提高了约8mg/L,经纯化后抗体纯度可达85%以上。因此,利用P.pastoris表达系统制备抗速灭威单链抗体比细菌表达系统更有效、更经济。 相似文献
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针对高地隙喷雾机在自主导航作业中因侧滑影响而导致轨迹跟踪精度降低的问题,提出一种基于四轮独立驱动(4WID)高地隙无人喷雾机的自适应控制方法。首先,建立4WID高地隙喷雾机的运动学模型;然后基于运动学几何约束和速度约束,引入两个表征侧滑效应的参数构建改进位姿误差模型;最后将参数自适应与反步控制方法结合,设计自适应控制律实时估计并补偿侧滑效应。以典型的U形作业路径为例,在考虑和不考虑侧滑的情况下分别进行了仿真和试验验证。仿真结果表明:本文提出的控制算法在喷雾机出现侧滑的情况下可以保证较高的轨迹跟踪精度;水田试验表明,当喷雾机在常规作业速度3.6km/h时,与不考虑侧滑的轨迹跟踪控制算法相比,喷雾机轨迹跟踪的横向平均绝对误差减小至0.041m,标准差减小至0.059m;纵向平均绝对误差减小至0.018m,标准差减小至0.015m;航向平均绝对误差减小至2.56°,标准差减小至3.57°。 相似文献
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用60 Co C射线辐照文蛤幼贝, 研究其对文蛤生长及抗病性的影响。A 组预试验结果表明: 低剂量60 Co C射线辐照对促生长有效, 高剂量辐射抑制了文蛤生长。B组正式试验辐照剂量(低剂量) 3. 23 @ 10- 7 ~ 25. 80 @ 10- 7C / kg。低剂量辐射试验结果表明: 46 d后, 试验组平均壳高及平均体重均高于对照组, 分别增加15% ~ 21% 和16% ~ 26%; 276 d后, 试验组的平均壳高较对照组增加17% ~ 23%, 且试验组文蛤的抗病性远优于对照组。61 45@ 10- 7 ~ 19. 35 @ 10- 7 C /kg 低剂量为促进文蛤幼贝生长、提高抗病性的有效剂量范围。 相似文献
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AIM: To investigate the effect of electroacupuncture treatment on microglia phenotype in Beagle dogs with abducens nerve injury. METHODS: Healthy adult Beagle dogs were randomly divided into 4 groups:normal control group, sham operation group, injury group and electroacupuncture treatment group, with 5 dogs in each group. In sham operation group, only the isolated nerves were exposed. In injury group, the dogs were restrained when electroacupuncture was performed in electroacupuncture treatment group. In electroacupuncture treatment group, electroacupuncture was performed on the base of dog nerve injury. The experiment was continued for 2 weeks. Western blot was used to detect the expression levels of M1 and M2 markers in the microglia. RESULTS: The expression of inducible nitric oxide synthase (iNOS) in injury group was significantly higher than that in control group (P<0.05). In electroacupuncture treatment group, the expression of iNOS was significantly lower than that in injury group (P<0.05). The expression of interleukin-1β (IL-1β) in injury group and electroacupuncture treatment group was higher than that in control group and that in electroacupuncture treatment group was significantly lower than that in injury group (P<0.05). The expression of arginase in injury group and electroacupuncture treatment group was higher than that in control group (P<0.05), and that in electroacupuncture treatment group was higher than that in injury group (P<0.05). Meanwhile, the expression of brain-derived neurotrophic factor (BDNF) in injury group and electroacupuncture treatment group was increased compared with control group (P<0.05). But the expression of BDNF in electroacupuncture treatment group was higher than that in injury group (P<0.05).CONCLUSION: After abducens nerve injury, electroacupuncture treatment reduces the expression levels of M1 marker proteins in microglia and increases the expression levels of M2 marker proteins. 相似文献
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《Pesticide biochemistry and physiology》1987,28(2):163-171
Uptake, movement, and metabolism of unformulated ioxynil and bromoxynil salts were investigated in Matricaria inodora and Viola arvensis. The morphology of these two species did not give rise to different spray retention and contact angles. After 7 days, uptake of [14C]ioxynil-Na reached 8.26% of applied 14C activity in M. inodora and 16.77% of that in V. arvensis compared with 1.54 and 3.83%, respectively, for [14C]bromoxynil-K. Over 98% of the 14C activity detected in the plant after 7 days remained in the treated leaves of V. arvensis following [14C]ioxynil-Na treatment. However, 8.7% of the 14C activity detected in [14C]ioxynil-Na-treated M. inodora was recovered from the apex and developing leaves reflecting a greater translocation. [14C]Bromoxynil-K was more mobile in both species and after 7 days 87.5 and 91.39% were detected in the treated leaves of M. inodora and V. arvensis, respectively. In both species the majority of translocated 14C activity was recovered from the apex and developing leaves. Up to 20% of the applied [14C]ioxynil-Na and [14C]bromoxynil-K was not detected within the treated plant. Extraction of treated plants revealed no detectable metabolic breakdown of ioxynil-Na to halogenated derivatives in either species. However, metabolic breakdown of bromoxynil-K was apparent in V. arvensis. No significant root exudation was detected when [14C]ioxynil-Na and [14C]bromoxynil-K were applied to hydroponically grown S. media and V. arvensis. Losses of 14C activity were due to herbicide volatility or degradation to volatile products on the leaf surface. 相似文献
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为了掌握轴流泵叶顶泄漏涡(TLV)的形成演化机理,评估涡形成空化条件和间隙宽度的影响,进行了轴流泵间隙泄漏流动实验和数值计算分析。通过流线涡量云图三维可视化分析,得到间隙流动特征及其涡结构,并比较分析涡初生时吸力面的速度流线、涡量和湍动能。对比了不同截面的物理量分布,并对不同空化条件下空化发展与TLV涡强度之间的关系进行了分析。研究表明:泄漏剪切带是形成TLV的主要区域,该区域的湍动能和涡量均较大,轴向主流与间隙射流形成对流,促进了涡的生成和发展,大间隙下的泄漏流速、涡强度与涡尺度更大;TLV核心区涡旋来自剪切带形成的剪切涡和周向的来流涡。在大空化数下,涡与空化分布基本一致,涡强度与空化正相关,叶顶涡空化在大间隙时延伸更远。在小空化数下,涡与空化位置不完全重合,空化形成所需要的涡强度较低,易扩展形成片状空化,间隙宽度对空化的影响较小。 相似文献
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以微晶纤维素和3,5-二甲基苯基异氰酸酯为原料合成了纤维素-三(3,5-二甲基苯基氨基甲酸酯),涂敷于氨丙基硅烷化硅胶上制成手性固定相.并以β-环糊精衍生物为手性流动相添加剂在手性柱上进行对映体的拆分.结果表明:当使用手性固定相和含有手性添加剂的流动相分离手性化合物时存在手性两相协同作用,其中以2,3,6-三甲基-β-环糊精(TM--βCD)为流动相添加剂时的效果最好. 相似文献