软X射线在泰坦大气模拟物上合成DNA核碱基
DNA Nucleobase Synthesis at Titan Atmosphere Analog by Soft X-rays
摘要：
土卫六是土星最大的卫星，其大气层主要由N2和CH 4组成，并含有许多简单的有机化合物。这个大气层也部分由薄雾和气溶胶粒子组成，在过去的4.5千兆年中，这些粒子被放电、离子和电离光子处理过，慢慢地沉积在泰坦表面。在这项工作中，我们研究了软X射线（和次级电子）对土卫六气溶胶类似物产生的可能影响，试图模拟一些前生物光化学。实验已在一个高真空室内进行耦合到软X射线光谱光束线在巴西同步辐射光源，坎皮纳斯，巴西。原位样品分析通过傅里叶变换红外光谱仪进行。红外光谱显示了几种有机分子，包括腈和芳香CN化合物。照射后，通过气相色谱（GC/MS）和核磁共振（1H NMR）技术对棕橙色有机残留物（托林）进行了非原位分析，揭示了DNA分子的成分之一腺嘌呤（C5 H5 N5）的存在。这证实了以前的结果，即土卫六表面的有机化学可能非常复杂，并且富含益生元化合物。早期地球上的这些分子已经找到了一个让生命（正如我们所知道的）蓬勃发展的地方。
英文摘要：
Titan, the largest satellite of Saturn, has an atmosphere chiefly made up of N2 and CH4 and includes traces of many simple organic compounds. This atmosphere also partly consists of haze and aerosol particles which during the last 4.5 gigayears have been processed by electric discharges, ions, and ionizing photons, being slowly deposited over the Titan surface. In this work, we investigate the possible effects produced by soft X-rays (and secondary electrons) on Titan aerosol analogs in an attempt to simulate some prebiotic photochemistry. The experiments have been performed inside a high vacuum chamber coupled to the soft X-ray spectroscopy beamline at the Brazilian Synchrotron Light Source, Campinas, Brazil. In-situ sample analyses were performed by a Fourier transform infrared spectrometer. The infrared spectra have presented several organic molecules, including nitriles and aromatic CN compounds. After the irradiation, the brownish-orange organic residue (tholin) was analyzed ex-situ by gas chromatographic (GC/MS) and nuclear magnetic resonance (1H NMR) techniques, revealing the presence of adenine (C5H5N5), one of the constituents of the DNA molecule. This confirms previous results which showed that the organic chemistry on the Titan surface can be very complex and extremely rich in prebiotic compounds. Molecules like these on the early Earth have found a place to allow life (as we know) to flourish.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
