10 research outputs found
Liver tumors induced in rats by 3\u27-methyl-4-dimethyl aminoazobenzene : III. electron microscopic investigation - disdifferentiation of cancer cells
Liver tumors induced in rats by 3\u27-methyl-4-dimethyl aminoazobenzene : II. electron microscopic investigation - dedifferentiation of cancer cells
Liver tumors induced in rats by 3\u27-methyl-4-dimethyl aminoazobenzene : I. histologic investigation
Liver tumors induced in rats by 3'-methyl-4-dimethyl aminoazobenzene : III. electron microscopic investigation - disdifferentiation of cancer cells
Liver tumors induced in rats by 3'-methyl-4-dimethyl aminoazobenzene : II. electron microscopic investigation - dedifferentiation of cancer cells
Liver tumors induced in rats by 3'-methyl-4-dimethyl aminoazobenzene : I. histologic investigation
First-Principles Investigation of Strong Excitonic Effects in Oxygen 1s X-ray Absorption Spectra
Macromolecular organic matter in samples of the asteroid (162173) Ryugu
International audienceINTRODUCTION: Organic compounds in asteroids and comets contain information about the early history of the Solar System. They could also have delivered organic material to early Earth. The Hayabusa2 spacecraft visited the carbonaceous asteroid Ryugu and collected samples of its surface materials, which were brought to Earth in December 2020. RATIONALE: We investigated the macromolecular organic matter in the Ryugu samples, measuring its elemental, isotopic, and functional group compositions along with its small-scale structures and morphologies. Analytical methods used included spectro-microscopies, electron microscopy, and isotopic microscopy. We examined intact Ryugu grains and insoluble carbonaceous residues isolated by acid treatment of the Ryugu samples. RESULTS: Organic matter is abundant in the Ryugu grains, distributed as submicrometersized organic grains and as organic matter dispersed in matrix. The Ryugu organic matter consists of aromatic carbons, aliphatic carbons, ketones, and carboxyls. The functional grou