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Purpose: The 1:1 spin-orbit resonance phenomenon is widely observed in binary asteroid systems. We aim to investigate the intrinsic dynamic mechanism behind the phenomenon under the coupled influence of the secondary's rotation and orbital motion. Methods: The planar sphere–ellipsoid model is used to approximate the synchronous binary asteroid. The Lindstedt–Poincaré method is applied on the spin-orbit problem to find its explicit quasi-periodic solution. Results: Numerical simulations demonstrate that analytical solutions truncated at high orders are accurate enough to describe the orbital and rotational motions of the synchronous binary asteroid. With the help of the solution, we are able to identify in a more accurate way the stable region for the synchronous state by using the Lyapunov characteristic exponent. Moreover, the resonances that determine the boundary of the stability region are identified. Conclusion: The stable synchronous state requires a small eccentricity e of the mutual orbit but permits a large libration angle θ of the secondary. The anti-correlation of θ and e is confirmed. The stable region for a very elongated secondary is small, which helps explain the lack of such secondaries in observations (see Table 1 in Pravec et al. in Icarus 267:267–295, 2016). Findings of this study provide insights into the inherent dynamics that determine the rotational states of a synchronous binary asteroid. [ABSTRACT FROM AUTHOR]

MicroRNAs have been implicated as a central regulator of the immune system. We have previously reported that Helicobacter pylori ( H. pylori) was able to increase the expression of miR-146a, and miR-146a may negatively regulate H. pylori-induced inflammation, but the exact mechanism of how H. pylori contribute the induction of miR-146a is not clear. Here, we attempted to assess the role of H. pylori related proinflammatory cytokines including interleukin (IL)-8, tumor necrosis factor (TNF)-α, and interleukin (IL)-1β, and cytotoxin-associated gene A (CagA) virulence factor on the induction of miR-146a. We found that IL-8, TNF-α, and IL-1β could contribute to the induction of miR-146a in gastric epithelial cell HGC-27 in NF-κB-dependent manner, while the induction of miR-146a upon H. pylori stimulation was independent of above proinflammatory cytokines. Furthermore, overexpression of miR-146a reduced H. pylori-induced IL-8, TNF-α, and IL-1β . However, CagA had no effect on the miR-146a induction. Taken together, our study suggest that proinflammatory cytokines IL-8, TNF-α, and IL-1β could contribute to the induction of miR-146a during H. pylori infection, while CagA is not necessarily required for miR-146a induction. miR-146a may function as novel negative regulators to modulate the inflammation. [ABSTRACT FROM AUTHOR]

It is very important to select and identify superior Xanthoceras sorbifolia Bge. trees for purposes of breeding and exploration. For our study, we selected superior X. sorbifolia trees using RAPD (random amplification of polymorphic DNA) technology. The results show that certain specific amplification bands emerged with significantly different frequencies between superior and non-superior trees. The 1400-bp band of No. 2121 primer emerged in the superior trees at a frequency 2.4 times that of the non-superior trees and the 600-bp band of No. 2153 primer in the non-superior trees at a frequency 2.5 times that of the superior trees. There were very significant differences between the superior and non-superior trees. The frequency of the 1600-bp band of No. 1161 primer was the same in both kinds of trees, but significant differences were observed in point frequency (the frequency of the superior trees is 1.4 times that of the non-superior trees). These bands can be used as important targets to distinguish between superior and non-superior trees. The use of a combination of amplified bands simultaneously can play a guiding role in the selection of superior X. sorbifolia trees. [ABSTRACT FROM AUTHOR]