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131.
We isolated five polymorphic microsatellite loci from the drepanosiphid aphid Tuberculatus quercicola (Matsumura) that is associated with the Daimyo oak, Quercus dentata Thunberg, using the magnetic particles method. The isolated loci were polymorphic, with four to 16 alleles in 40 aphids. Expected heterozygosities ranged from 0.4 to 0.82. These loci can be used to quantify seasonal changes in clonal diversity in the metapopulation and the extent of clonal mixing in the colonies.  相似文献   
132.
Summary The sequence of events during the electrically induced fusion of human erythrocytes was studied by rapid quench freeze-fracture electron microscopy. A single electric field pulse was used to induce fusion of human erythrocytes treated with pronase and closely positioned by dielectrophoresis. The electronic circuit was coupled to a rapid freezing mechanism so that ultrastructural changes of the membrane could be preserved at given time points. Pronase treatment enabled adjacent cells to approach each other within 15 nm during dielectrophoresis. The pulse caused a brief disruption of the aqueous boundaries which separated the cells. Within 100 msec following pulse application, the fracture faces exhibited discontinuous areas which were predominantly free of intramembranous particles. At 2 sec after the pulse, transient point defects attributed to intercellular contact appeared in the same membrane areas and replaced the discontinuous areas as the predominant membrane perturbation. At 10 sec after the pulse, the majority of the discontinuous areas and point defects disappeared as the intercellular distance returned to approximately 15 to 25 nm, except at sites of cytoplasmic bridge formation. Intramembranous particle clearing was observed at 60 sec following pulse application in discrete zones of membrane fusion.  相似文献   
133.
The features that Magic Lite products offer as an immunoassay delivery system are discussed. The use of paramagnetic particles and acridinium ester labels confers advantages of speed, sensitivity, and stability. The technology has been used to measure analytes of widely varying molecular weights and serum concentrations, indicating its potential to detect the full range of clinically relevant analytes. Initial development efforts have indicated that the advantages of the system can be effectively exploited in an automated instrument.  相似文献   
134.
It is known that the negatively stained preparations of inner mitochondrial membrane display characteristic ∼9 nmF 1 (ATPase) knobs projecting from the matrix surface. Freeze-etch studies have reported the absence of such knobs from the “etched” surface of the inner mitochondrial membranes. We have demonstrated their presence on the surface of SMP (submitochondrial particles) prepared by freeze-drying for transmission electron microscopy. This identification has been substantiated by comparison with the freeze-dried TU particles (trypsin-urea treated SMP) that are devoid ofF 1 (ATPase). It has been suggested that a layer of water molecules is strongly adsorbed to the surface of SMP and does not sublime during normal freeze-“etching.”  相似文献   
135.
Interfacial bioconjugation methods are developed for intact liquid emulsion droplets. Complex emulsion droplets having internal hydrocarbon and fluorocarbon immiscible structured phases maintain a dynamic interface for controlled interfacial reactivity. The internal morphological change after binding to biomolecules is readily visualized and detected by light transmission, which provides a platform for the formation of inexpensive and portable bio-sensing assays for enzymes, antibodies, nucleic acids and carbohydrates.  相似文献   
136.
目的:探讨氧化应激对磷酸三钙(TCP)磨损颗粒诱导的假体周围骨溶解的影响及其作用机制。方法:36只雄性ICR小鼠随机分为3组(n=12):假手术(Sham)组、TCP磨损颗粒(TCP)组和N-乙酰-L-半胱氨酸(NAC)组。将TCP磨损颗粒30 mg包埋于小鼠颅骨顶部构建假体周围骨溶解模型,于术后第2天颅顶骨膜局部注射NAC(1.0 mg/kg),隔日1次,持续2周后处死动物采血、取颅骨。抗酒石酸酸性磷酸酶(TRAP)染色观察小鼠颅骨假体周围骨溶解情况;ELISA和化学比色法检测血清中肿瘤坏死因子-α(TNF-α)、白介素-1β(IL-1β)、白介素-6(IL-6)和总抗氧化能力(T-AOC)含量及超氧化物歧化酶(SOD)活性;Western blot检测假体周围骨组织中内质网应激标志蛋白葡萄糖调节蛋白78(GRP78)、蛋白激酶R样内质网激酶(PERK)、磷酸化PERK(p-PERK)、真核细胞翻译起始因子2α(eIF2α)和磷酸化eIF2α(p-eIF2α)的表达。结果:与Sham组比较,TCP组小鼠血清TNF-α、IL-1β和IL-6水平及假体周围骨溶解面积显著增加(P<0.05),T-AOC含量和SOD活性明显降低(P<0.05),GRP78蛋白质表达、p-PERK/PERK和p-eIF2α/eIF2α值显著升高。与TCP组比较,NAC组小鼠血清TNF-α、IL-1β和IL-6水平及骨溶解面积明显减少(P<0.05),血清T-AOC含量和SOD活性明显增加(P<0.05),GRP78蛋白质表达、p-PERK/PERK和p-eIF2α/eIF2α值明显降低。结论:抑制氧化应激可阻止TCP磨损颗粒诱导的假体周围骨溶解,其机制可能与PERK/eIF2α通路的失活有关。  相似文献   
137.
目的:研究纳米炭黑颗粒复合寒冷暴露对小鼠肺部组织结构及其氧化应激反应的影响。方法:将72只健康雄性C57BL/6小鼠随机分为6组:对照(Ctrl)组、单纯冷暴露(C)组、低剂量染毒(L)组、低剂量染毒复合冷暴露(LC)组、高剂量染毒(H)组、高剂量染毒复合冷暴露(HC)组。采用吸入式气管滴注染毒方式,一次性滴注纳米炭墨颗粒染毒液40 μl,浓度分别为0.45 mg/ml (L)和4.05 mg/ml (H)。冷暴露方式为4℃暴露,4 h/d,连续20 d。暴露结束24 h后称重、取样,进行相关指标测定。采用试剂盒法测定小鼠肺组织匀浆中超氧化物歧化酶(SOD)活力、谷胱甘肽过氧化物酶(GSH-Px)活力和丙二醛(MDA)含量;肺组织块HE染色,观察肺组织病理组织结构改变。结果:所有冷暴露处理组小鼠的体重均显著低于所有非冷暴露组(P<0.05),对照组及单纯染毒组小鼠体重均在实验开始14 d后明显升高(P<0.05),单纯冷暴露组与纳米炭黑颗粒染毒复合冷暴露组小鼠体重均在14 d后趋于稳定。HE检测结果表明,单纯纳米炭黑颗粒染毒组及染毒复合冷暴露组小鼠肺泡腔内均有黑色颗粒沉积,高剂量染毒复合冷暴露组可见肺泡结构破环,排列凌乱,有大量炎细胞浸润。与对照组相比,其余各组SOD活力均显著降低(P<0.05);高剂量染毒组及高剂量染毒复合冷暴露组GSH-Px活力明显低于对照组(P<0.01);与对照组相比,高剂量染毒组、低剂量染毒与高剂量染毒复合冷暴露组MDA含量显著升高(P<0.01)。两因素方差分析提示,随着染毒剂量的增加,SOD活力及GSH-Px活力显著降低(P<0.05);随着温度的降低,肺组织MDA含量显著升高(P<0.05),4℃间歇性冷暴露与纳米颗粒物暴露对肺组织SOD、GSH-Px活力及MDA含量的影响均无交互作用。结论:纳米炭黑颗粒复合寒冷暴露可导致小鼠肺部炎症反应加重,氧化应激水平升高。  相似文献   
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140.
Herbal remedies were the first medicines used by humans due to the many pharmacologically active secondary metabolites produced by plants. Some of these metabolites inhibit cell division and can therefore be used for the treatment of cancer, e.g. the mitostatic drug paclitaxel (Taxol). The ability of plants to produce medicines targeting cancer has expanded due to the advent of genetic engineering, particularly in recent years because of the development of gene editing systems such as the CRISPR/Cas9 platform. These technologies allow the introduction of genetic modifications that facilitate the accumulation of native pharmaceutically-active substances, and even the production heterologous recombinant proteins, including human antibodies, lectins and vaccine candidates. Here we discuss the anti-cancer agents that are produced by plants naturally or following genetic modification, and the potential of these products to supply modern healthcare systems. Special emphasis will be put on proteinaceous anti-cancer agents, which can exhibit an improved selectivity and reduced side effects compared to small molecule-based drugs.  相似文献   
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