Abstract: The present invention pertains to a supramolecular structure based on i-motif tetramers of Cm—X—Cn oligonucleotides, wherein m and n are integers comprised between 2 and 9, and X is a linker such as A, T, G, a modified deoxynucleotide or a diol spacer. These supramolecular structures can be dissociated, when necessary, by a mere pH change. The present invention also relates to methods for obtaining such a supramolecular structure.

Abstract: An `i-motif` nucleic acid, DNA and/or RNA, complex characterized by the presence of at least four cytosine-rich stretches or stretches rich in cytosine derivatives, including two parallel-stranded duplexes in which the cytosines or derivatives thereof form base pairs, said two duplexes being associated anti-parallel to one another, and said pairs of cytosine or derivatives thereof of one duplex being intercalated with those of the other duplex.

Abstract: A fuel injection device for an internal combustion engine, in particular a diesel engine, the device is of the type comprising two spray heads, one spray head serving for pre-injection of fuel while the other serves for main injection of fuel, said spray heads being situated close to each other in the vicinity of the middle of the cylinder head. The pre-injection spray head includes a series of holes whose axes lie on a frist cone and the main injection spray head inlcudes a series of holes whose axes lie on a second cone, there being twice as many holes in the main spray head as in the pre-injection spray head, the relative positions of the cones, the angle of each of the cones, and the directions of the axes of the holes around the cones being selected in such a manner that the distances between each pre-injection jet and the two adjacent main injection jets are at a minimum and are substantially equal in a zone which is situated substantially halfway along the main injection jets.