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排序方式: 共有4632条查询结果,搜索用时 15 毫秒
1.
Ilaria Fraudentali Renato A. Rodrigues-Pousada Riccardo Angelini Sandip A. Ghuge Alessandra Cona 《International journal of molecular sciences》2021,22(10)
Polyamines are ubiquitous, low-molecular-weight aliphatic compounds, present in living organisms and essential for cell growth and differentiation. Copper amine oxidases (CuAOs) oxidize polyamines to aminoaldehydes releasing ammonium and hydrogen peroxide, which participates in the complex network of reactive oxygen species acting as signaling molecules involved in responses to biotic and abiotic stresses. CuAOs have been identified and characterized in different plant species, but the most extensive study on a CuAO gene family has been carried out in Arabidopsis thaliana. Growing attention has been devoted in the last years to the investigation of the CuAO expression pattern during development and in response to an array of stress and stress-related hormones, events in which recent studies have highlighted CuAOs to play a key role by modulation of a multilevel phenotypic plasticity expression. In this review, the attention will be focused on the involvement of different AtCuAOs in the IAA/JA/ABA signal transduction pathways which mediate stress-induced phenotypic plasticity events. 相似文献
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This article proposes new bootstrap procedures for detecting multiple persistence shifts in a time series driven by non-stationary volatility. The assumed volatility process can accommodate discrete breaks, smooth transition variation as well as trending volatility. We develop wild bootstrap sup-Wald tests of the null hypothesis that the process is either stationary [I(0)] or has a unit root [I(1)] throughout the sample. We also propose a sequential procedure to estimate the number of persistence breaks based on ordering the regime-specific bootstrap p-values. The asymptotic validity of the advocated procedures is established both under the null of stability and a variety of persistence change alternatives. A comparison with existing tests that assume homoskedasticity illustrates the finite sample improvements offered by our methods. An application to OECD inflation rates highlights the empirical relevance of the proposed approach and weakens the case for persistence change relative to existing procedures. 相似文献
3.
菌型叶根动叶片是一种新型的动叶片,采用数控铣加工叶根内径向面时留0.1~0.2mm余量,然后在进行叶根内径向磨削,叶冠直接加工到位,没有后序磨削加工,由于叶根叶冠在加工过程中不是一次装夹完成的,根冠存在一定的落差,在后续的装配中容易产生配合间隙,无法达到要求。文中介绍了一种新的加工工艺,解决了这一问题。 相似文献
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Free vibration of partially supported piles with the effects of bending moment, axial and shear force 总被引:1,自引:0,他引:1
The pile parts above the soil and embedded in the soil are called the first region and the second region, respectively. The fourth order partial differential equations of both regions for free vibration of partially supported pile subjected to bending moment, axial force and shear force are obtained using the small-displacement theory and the Winkler model. It is assumed that the behavior of the material is linear-elastic, and that axial force along the pile length and modulus of subgrade reaction for the second region to be constant. Shear effect is included in the partial differential equations by the second derivative of the elastic curve function with respect to shear deformation. Natural circular frequencies and relative stiffness of the pile are calculated for non-trivial solution of linear homogeneous system of equations obtained due to the values of axial forces acting on the pile, the shape factors, and the boundary conditions of the pile with both ends free and both ends simply supported; the results are presented in graphs. 相似文献
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How to select a generator of Zp* is an important problem in cryptographic applications, where p is an odd prime. In this paper, we mainly consider the especial case that p is a safe prime, and give an algorithm for selecting a generator of Zp*,and find all generators of Zp* , where p is a safe prime. Our algorithm is more faster than the algorithm in [1]. Based on the proposed algorithm, one could find all generators of Zp* as well, where p is a perfect prime. 相似文献
9.
甘草纤素对实验动物化学性肝损伤保护功能研究 总被引:1,自引:1,他引:0
目的:了解甘草纤素对大鼠化学性肝损伤的保护作用。方法:按照卫生部《保健食品功能学评价程序和检验方法》进行。并比较四氯化碳染毒后第48h和第5d处死动物对各项指标的影响。结果:与肝损伤模型对照组比较,染毒后第48h,甘草纤素的二个剂量组血清ALT(丙氨酸氨基转移酶)水平均有显著降低(p<0.05),中、高剂量组血清AST(天门冬氨酸氨基转移酶)水平也有显著降低(p<0.05)。受试物的高剂量组可改善肝细胞的退行性变,且高剂量组可明显减轻CCl4引起的肝细胞坏死(p<0.05)。结论:适量甘草纤素对CCl4所致动物急性肝损伤具有保护作用。 相似文献
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