A nanodiamond according to the present invention has acidic functional groups, contains the acidic functional groups in a number density of 1 or more per square nanometer in the nanodiamond surface, and has a specific surface area of 150 m.sup.2/g or more. Particles of the nanodiamond preferably have a D50 (median diameter) of 9 nm or less. The nanodiamond is preferably derived from a nanodiamond synthesized by a detonation technique (in particular, an air-cooling detonation technique).

A nanodiamond according to the present invention has acidic functional groups, contains the acidic functional groups in a number density of 1 or more per square nanometer in the nanodiamond surface, and has a specific surface area of 150 m.sup.2/g or more. Particles of the nanodiamond preferably have a D50 (median diameter) of 9 nm or less. The nanodiamond is preferably derived from a nanodiamond synthesized by a detonation technique (in particular, an air-cooling detonation technique).

An onium salt having formula (1) serving as an acid diffusion inhibitor and a chemically amplified resist composition comprising the acid diffusion inhibitor are provided. When processed by lithography, the resist composition forms a pattern having minimal defects and excellent lithography performance factors such as CDU, LWR and DOF.

##STR00001##

A drug design method associated with natural products, includes: acquiring a molecular structure of a to-be-modified natural product with a specific biological activity; using the molecular structure as a template molecule, selecting a plurality of natural products as a reference molecule set, where the plurality of natural products has the specific biological activity and a structural similarity thereof to the template molecule is within a threshold range; and selecting one or more reference molecules from the reference molecule set, comparing the one or more reference molecules with the template molecule and determining at least one different active functional group therebetween; and constructing the at least one different active functional group on a molecular scaffold shared by the template molecule and the one or more reference molecules, thereby obtaining a modified molecular structure of the natural product with the specific biological activity.

The present disclosure is generally directed to neuroactive substituted cyclopent[a]anthracenes as referenced herein, and pharmaceutically acceptable salts thereof, for use as, for example, an anesthetic, and/or in the treatment of disorders relating to GABA function and activity. The present disclosure is further directed to pharmaceutical compositions comprising such compounds.

The present invention provides the onium salt comprises the material represented by the following general formula (0-1), ##STR00001##
wherein R.sup.f represents a fluorine atom or a trifluoromethyl group; Y represents a cyclic hydrocarbon group having 3 to 30 carbon atoms, the hydrogen atom in the cyclic hydrocarbon group may be substituted by a hetero atom itself or a monovalent hydrocarbon group which may be substituted by a hetero atom(s), and the hetero atom(s) may be interposed into the cyclic structure of the cyclic hydrocarbon group and the monovalent hydrocarbon group; and M.sup.+ represents a monovalent cation. There can be provided an onium salt which can improve resolution at the time of forming a pattern and give a pattern with less line edge roughness (LER) when it is used in a chemically amplified positive resist composition.

The present invention provides the onium salt comprises the material represented by the following general formula (0-1), ##STR00001##
wherein R.sup.f represents a fluorine atom or a trifluoromethyl group; Y represents a cyclic hydrocarbon group having 3 to 30 carbon atoms, the hydrogen atom in the cyclic hydrocarbon group may be substituted by a hetero atom itself or a monovalent hydrocarbon group which may be substituted by a hetero atom(s), and the hetero atom(s) may be interposed into the cyclic structure of the cyclic hydrocarbon group and the monovalent hydrocarbon group; and M.sup.+ represents a monovalent cation. There can be provided an onium salt which can improve resolution at the time of forming a pattern and give a pattern with less line edge roughness (LER) when it is used in a chemically amplified positive resist composition.