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171.
Considerable research has indicated that heat shock proteins (Hsp), as molecular chaperones, carry out many biological activities of plant viruses by folding, transporting, translocating, assembling, or degrading client proteins. It is fundamental to develop resistant plant varieties and novel anti-viral agents by determining the interaction mechanisms between plant viruses and hosts. In this study, we first reviewed the classification, gene and protein structure, and biological significances. We then analyzed the assembling mechanism of Hsp70 or Hsp90, plant host cofactors, and RNA-dependent RNA polymerases in a viral replicase complex, and the mechanism of interaction and subcellular localization between Hsp70 and some plant virus components. We highlighted the mechanism of interaction and movement between Hsp70 and some plant virus components and the effect of Hsp expression of plant hosts or viruses. The results indicated where the mechanism occurred, the participating factors, energy supply, and material conversion between Hsps and the plant virus components for the course of the intracellular movement, local movement between cells, and long-distance movement, and showed the Hsp type specificity and the law of dynamic Hsp expression in plant hosts infected by viruses. The studies mainly focused on the two Hsp factors and the plant viral components, indicating limited coordination mechanisms among many nucleic acids, proteins, and polysaccharides in macromolecular protein complexes (MRC). Future research should analyze the translocation mechanism between client proteins and Hsps, the coordination mechanism between Hsps and MRC components, and the relation between MRC and the plant tissue structure. © 2018 Science Press. All rights reserved. 相似文献
172.
为探讨北京不同污染天气大气可吸入颗粒物PM_(10)和细颗粒物PM_(2.5)污染对雄性大鼠血常规、氧化损伤、炎症反应和肺组织的影响,将64只雄性8周龄Wistar大鼠随机分为8组,分别为2个对照组(空白组和生理盐水组)和6个染毒组(清洁、雾霾及沙尘暴3种不同天气的PM_(10)染毒组和PM_(2.5)染毒组),每组8只。用2015年3月—5月在北京南海子麋鹿苑采集的清洁、雾霾和沙尘暴3种不同天气的PM_(10)和PM_(2.5)制备悬液,分别采用气管滴入PM_(10)和PM_(2.5)悬液作为染毒组,空白对照组不做任何处理,生理盐水对照组采用气管滴注生理盐水。急性染毒24 h后处死大鼠。采集血液测定18个血常规指标,分析肺泡灌洗液(BALF)中转化生长因子-β1(TGF-β1)、乳酸脱氢酶(LDH)、总抗氧化能力(T-AOC)、白介素-6(IL-6)及肿瘤坏死因子-α(TNF-α)的含量,并在高倍显微镜下观察肺组织和气管病理形态变化。同时,对PM_(10)和PM_(2.5)中的水溶性离子、有机碳/元素碳、16种多环芳烃和7种重金属等元素进行了测定,并分析了各组分与大鼠生理病理指标的相关性。结果表明:清洁、沙尘暴天气的PM_(10)和雾霾天气的PM_(2.5)急性染毒导致大鼠白细胞系参数即免疫力显著下降。污染天气颗粒物染毒后大鼠BALF氧化炎症因子的改变表明呼吸系统受到感染:沙尘暴和清洁天的PM_(10)染毒均显著提高了TGF-β1,雾霾PM_(10)染毒后IL-6和LDH有一定程度升高。3种天气颗粒物染毒对肺和气管造成的组织病理伤害各有特点,但PM_(2.5)伤害程度普遍大于PM_(10)。染毒颗粒物粒径大小,其化学成分类别、浓度是造成大鼠血常规指标变化、氧化炎症反应和组织学病变的可能原因。 相似文献
173.
针对大豆蛋白粉生产过程中喷雾干燥塔尾气温度较高,有回收利用价值的现实,也针对目前的节能需求,对现有的喷雾干燥塔的尾气排放部分进行改造,设计一个片状空气预热器,以利用高温的尾气与系统的进气做热交换,实现热量再利用,降耗和提高蛋白粉产率的目的,并对投资收益进行了分析。 相似文献
174.
Erna von Heimburg Jon Ingulf Medbø Mariann Sandsund Randi Eidsmo Reinertsen 《International journal of occupational safety and ergonomics》2013,19(2):227-243
Aim. Firefighters must meet minimum physical demands. The Norwegian Labour Inspection Authority (NLIA) has approved a standardised treadmill walking test and 3 simple strength tests for smoke divers. The results of the Trondheim test were compared with those of the NLIA tests taking into account possible effects of age, experience level and gender. Methods. Four groups of participants took part in the tests: 19 young experienced firefighters, 24 senior male firefighters and inexperienced applicants, 12 male and 8 female. Results. Oxygen uptake (VO2) at exhaustion rose linearly by the duration of the treadmill test. Time spent on the Trondheim test was closely related to performance time and peak VO2 on the treadmill test. Senior experienced firefighters did not perform better than equally fit young applicants. However, female applicants performed poorer on the Trondheim test than on the treadmill test. Performance on the Trondheim test was not closely related to muscle strength beyond a minimum. Conclusion. Firefighters completing the Trondheim test in under 19 min fit the requirements of the NLIA treadmill test. The Trondheim test can be used as an alternative to the NLIA tests for testing aerobic fitness but not for muscular strength. Women’s result of the Trondheim test were poorer than the results of the NLIA treadmill test, probably because of their lower body mass. 相似文献
175.
176.
Relation of hepatic EROD activity and cytochrome P4501A level in Sebastiscus
marmoratus exposed to benzo[a]pyrene 总被引:1,自引:0,他引:1
This study was designed to investigate the in vivo effects of benzo[a]pyrene (BaP) on hepatic ethoxyresorufin-O-deethylase (EROD) activity and its correlation with cytochrome P4501A (CYP1A) protein levels in Sebastiscus marmoratus, which were exposed through a water column to BaP (10, 100, 1000 ng/L, respectively) or were treated with intraperitoneal injections of BaP (0.5, 1, 5, 10 mg/kg, respectively) every 7 d. The results showed that after 25 d of waterborne exposure to 1000 ng/L BaP, fish hepatic CYP1A levels and EROD activity were significantly induced. In contrast, EROD activity was not altered 7 d after second intraperitoneal injections, whereas, CYP1A protein levels were increased. Dose-dependent increase of biliary BaP metabolites demonstrated that the catalytic activity of CYP1A was induced by treatment with BaP. The lowest observable effect concentration with regard to biliary BaP metabolites (100 ng/L) was much lower than that with reference to EROD activity (1000 ng/L). The results suggest that biliary polycyclic aromatic hydrocarbon (PAH) metabolites were shown to better reflect the contamination gradients of PAHs than EROD activity. It appeared to be necessary to measure CYP1A protein levels to complement the EROD activity in relevant toxicological assessments. 相似文献
177.
178.
土壤球囊霉素相关蛋白(glomalin-related soil protein,GRSP)是评价土壤健康的重要指标。研究了土样粒径、贮存条件和高温提取后离心延误时间3个影响因子对采用Bradford法测定GRSP含量的作用效果。结果表明,土样粒径对易提取GRSP(EEG)的提取测定影响显著,过0.074 mm孔径筛土样中提取出的EEG含量高于过0.149、0.25、1 mm孔径筛的土样;总GRSP(TG)含量的测定结果对土样粒径的变化没有明显响应,测定TG含量可采用过1 mm孔径筛的土样。贮存条件影响EEG和TG含量的测定,有机质含量低的土样室温保存18个月条件下测得的EEG含量低于-20℃保存条件下;有机质含量高的土样室温保存条件下测得的EEG含量高于-20℃保存条件下;室温保存条件下3个有机质含量水平的土样TG含量均高于-20℃保存条件下。不同样品保存方式间3个有机质含量水平的土样EEG或TG含量差异均显著。为减小有机质降解等的影响,宜低温保存土样。提取后延误离心将导致EEG含量测定值降低,因此延误时间以控制在1 h之内为宜;离心延误2 h内不同延误时间之间测得的TG含量无显著差异。 相似文献
179.
根据2013型铁将军牌摩托车防盗器工作原理,分析了连接左转向灯、起动继电器及电门锁的5条导线遥控引燃黑火药的方式.利用GOS-620型示波器,测得防盗器在设防、寻车、起动、振动1次、连续振动、解锁时这5根导线两两之间的电压.从60种组合中筛选出10种可能引燃黑火药的方式.通过引燃实验,验证了这10种引燃方式.以左转向灯... 相似文献
180.
为考察聚磷酸铵(APP)干粉灭火剂的聚合度对其灭火性能的影响,选用3种不同聚合度的APP,结合其晶体结构、粒度分布及热性能测试,并通过粉体杯式燃烧器进行小尺寸灭火实验,对比3种样品的灭火性能及灭火机理,研究聚合度与其灭火性能的关系。热性能测试结果显示,聚合度的升高会导致APP的热稳定性下降,随着聚合度从80升至1 500,其初始分解温度从326.11 ℃降低至321.54 ℃,失重率从75.21%增加至79.66%。实验结果表明:随着APP聚合度的增加,火焰降温速率升高,最小灭火浓度(MEC)降低,灭火性能增强,当聚合度为1 500时,MEC为118.143 g/m3。聚合度的升高有助于APP在进入火场后更早、更充分地与火焰发生反应,从而使灭火性能得到提升。 相似文献