在质子和α粒子辐射下对DNA的电子激发动力
1Department of Chemistry , The University of North Carolina at Chapel Hill , Chapel Hill , North Carolina 27599 , United States.
Journal of the American Chemical Society
|March 14, 2019
概括
第一原理模拟显示,对DNA的离子辐射会产生洞,与X射线/马射线效应不同. 激发孔的产生与能量转移率无关, 挑战目前的辐射瘤学假设.
科学领域:
- 原子和分子物理学
- 化学物理
- 辐射生物学
背景情况:
- 离子辐射会诱导DNA中的电子激发,这对于理解放射性癌症治疗至关重要.
- 目前的模型通常依赖于线性响应理论来描述这些相互作用.
研究的目的:
- 模拟DNA对质子和α粒子的非扰动性电子反应.
- 在描述离子束诱导的DNA损伤时测试线性反应理论的有效性.
- 为了阐明DNA中电子激发的量子动力学.
主要方法:
- 通过对能量质子和α粒子进行的DNA动力学模拟.
- 模拟结果与线性响应理论预测的比较.
- 分析电子制动功率和能量传输率.
主要成果:
- 模拟表明质子和α粒子辐射会导致DNA电离和产生孔.
- 与X/玛辐射相比,在DNA激发行为中观察到显著的差异.
- 激发孔的产生与能量转移速率与离子速度没有直接的相关性.
结论:
- 线性反应理论可能无法完全捕捉由离子辐射诱导的复杂电子激发.
- 这些发现挑战了放射性瘤学关于能量转移和DNA损伤的既定假设.
- 提供了前所未有的关于DNA电子激发的量子动力学的细节.
相关概念视频
Subatomic Particles
112.8K
Dalton was only partially correct about the particles that make up matter. All matter is composed of atoms, and atoms are composed of three smaller subatomic particles: protons, neutrons, and electrons. These three particles account for the mass and the charge of an atom.
112.8K
The Nucleosome Core Particle
14.4K
Nucleosomes are the DNA-histone complex, where the DNA strand is wound around the histone core. The histone core is an octamer containing two copies of H2A, H2B, H3, and H4 histone proteins.
The paradox
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their main responsibility is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. While on the other hand, they must allow polymerase enzymes to access DNA...
The paradox
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their main responsibility is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. While on the other hand, they must allow polymerase enzymes to access DNA...
14.4K
Electron Carriers
91.7K
Electron carriers can be thought of as electron shuttles. These compounds can easily accept electrons (i.e., be reduced) or lose them (i.e., be oxidized). They play an essential role in energy production because cellular respiration is contingent on the flow of electrons.
Over the many stages of cellular respiration, glucose breaks down into carbon dioxide and water. Electron carriers pick up electrons lost by glucose in these reactions, temporarily storing and releasing them into the electron...
Over the many stages of cellular respiration, glucose breaks down into carbon dioxide and water. Electron carriers pick up electrons lost by glucose in these reactions, temporarily storing and releasing them into the electron...
91.7K
Electron Microscope Tomography and Single-particle Reconstruction
2.9K
Transmission electron microscopy (TEM) can be used to determine the 3D structure of biological samples with the help of techniques such as electron microscope tomography and single-particle reconstruction. While single-particle reconstruction can examine macromolecules and macromolecular complexes in vitro conditions only, tomography permits the study of cell components or small cells in vivo.
Electron Tomography
Electron tomography can be performed either in TEM or STEM (scanning transmission...
Electron Tomography
Electron tomography can be performed either in TEM or STEM (scanning transmission...
2.9K
Electron Transport Chains
112.0K
The final stage of cellular respiration is oxidative phosphorylation that consists of two steps: the electron transport chain and chemiosmosis. The electron transport chain is a set of proteins found in the inner mitochondrial membrane in eukaryotic cells. Its primary function is to establish a proton gradient that can be used during chemiosmosis to produce ATP and generate electron carriers, such as NAD+ and FAD, that are used in glycolysis and the citric acid cycle.
The ETC is comprised of...
The ETC is comprised of...
112.0K
Electron Behavior
108.0K
Overview
Electrons are negatively charged subatomic particles that are attracted to an orbit around the positively-charged nucleus of an atom. They reside in locations that are associated with energy levels called shells and are further organized into sub-shells and orbitals within each shell.
Electrons Orbit the Nucleus
Electrons are found in specific locations outside of the nucleus. The shell in which an electron resides indicates the general energy level of the electron: those closer to the...
Electrons are negatively charged subatomic particles that are attracted to an orbit around the positively-charged nucleus of an atom. They reside in locations that are associated with energy levels called shells and are further organized into sub-shells and orbitals within each shell.
Electrons Orbit the Nucleus
Electrons are found in specific locations outside of the nucleus. The shell in which an electron resides indicates the general energy level of the electron: those closer to the...
108.0K


