Investigation of Neutron-Induced Damage in DNA by Atomic Force Microscopy: Experimental Evidence of Clustered DNA Lesions

1998 ◽  
Vol 150 (6) ◽  
pp. 612 ◽  
Author(s):  
D. Pang ◽  
B. L. Berman ◽  
S. Chasovskikh ◽  
J. E. Rodgers ◽  
A. Dritschilo
Keyword(s):  
Atomic Force Microscopy ◽  
Experimental Evidence ◽  
Dna Lesions ◽  
Force Microscopy ◽  
Atomic Force

scholarly journals Direct observation of damage clustering in irradiated DNA with atomic force microscopy

2019 ◽  
Vol 48 (3) ◽  
pp. e18-e18 ◽  
Author(s):  
Xu Xu ◽  
Toshiaki Nakano ◽  
Masataka Tsuda ◽  
Ryota Kanamoto ◽  
Ryoichi Hirayama ◽  
...  
Keyword(s):  
Dna Damage ◽  
Atomic Force Microscopy ◽  
Ionizing Radiation ◽  
Ion Beams ◽  
Dna Lesions ◽  
X Rays ◽  
Damage Site ◽  
Force Microscopy ◽  
Atomic Force ◽  
Clustered Dna Damage

Abstract Ionizing radiation produces clustered DNA damage that contains two or more lesions in 10–20 bp. It is believed that the complexity of clustered damage (i.e., the number of lesions per damage site) is related to the biological severity of ionizing radiation. However, only simple clustered damage containing two vicinal lesions has been demonstrated experimentally. Here we developed a novel method to analyze the complexity of clustered DNA damage. Plasmid DNA was irradiated with densely and sparsely ionizing Fe-ion beams and X-rays, respectively. Then, the resulting DNA lesions were labeled with biotin/streptavidin and observed with atomic force microscopy. Fe-ion beams produced complex clustered damage containing 2–4 lesions. Furthermore, they generated two or three clustered damage sites in a single plasmid molecule that resulted from the hit of a single track of Fe-ion beams. Conversely, X-rays produced relatively simple clustered damage. The present results provide the first experimental evidence for complex cluster damage.

scholarly journals AFM Study of Pyrite Oxidation and Xanthate Adsorption in the Presence of Seawater Salts

Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1177 ◽  
Author(s):  
Álvaro Paredes ◽  
Sergio M. Acuña ◽  
Pedro G. Toledo
Keyword(s):  
Atomic Force Microscopy ◽  
Experimental Evidence ◽  
Fresh Water ◽  
Surface Reactions ◽  
Pyrite Oxidation ◽  
Mining Industry ◽  
Sulfide Minerals ◽  
Force Microscopy ◽  
Atomic Force

The effect of seawater ions presents a great challenge to theories about mechanisms of pyrite oxidation, collector adsorption, and surface reactions. As the use of seawater is key to the sustainability of the mining industry in regions without fresh water, there is a need to study the surfaces of minerals and products that are formed in the presence of seawater salts. In this study, atomic force microscopy (AFM) was used to analyze the topography of pyrite surfaces subjected to treatments, including oxidation and exposure to xanthate and solutions of seawater salts and xanthate, at pH 8.5. Topographic details were related to surface products. The results showed that xanthate was adsorbed without hindrance on oxide-free pyrite which validated one well-known model. The results also showed that pyrite oxidized forming a structure of interconnected pillars and that xanthate was adsorbed on the top and skirt of these pillars; the experimental evidence on the increase in the height and width of these pillars validated another well-known model. In the presence of seawater salts, the cations covered the surface of the pyrite, suppressing collector adsorption regardless of the dose. The results are expected to help in decisions about the flotation of sulfide minerals in water with limited metallurgical quality.

Electrostatic Forces on the Surface of Metals as Measured by Atomic Force Microscopy

2000 ◽  
Vol 10 (1-2) ◽  
pp. 15
Author(s):  
Eugene Sprague ◽  
Julio C. Palmaz ◽  
Cristina Simon ◽  
Aaron Watson
Keyword(s):  
Atomic Force Microscopy ◽  
Electrostatic Forces ◽  
Force Microscopy ◽  
Atomic Force
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