8 research outputs found
A stretcher and holder module
Abstract This paper describes the general structure and the performance of a compact module, designed to stretch and hold analog signals up to several hundreds of microseconds, without remarkable changes in the pulse height and shape, and to provide a convenient interface between detector systems and data acquisition equipment
CD and NMR Structural characterization of Ceratotoxins, Natural Peptides with Antimicrobial Activity
Antibacterial properties of the secretion from the female reproductive accessory glands of medfly Ceratitis capitata are mostly ascribed to the presence of two peptides, ceratotoxin A and B, which exhibit a strong activity against gram-positive and gram-negative bacterial strains, and show sequence and function homology with cecropins, melittin, and magainins. CD experiments performed in different solvents indicate the presence of a significant content of helical structures in organic solvent. Two-dimensional nmr results for ceratotoxin A in methanol show a helical behavior for the 8-25 region of the peptide. A ramachandran classification of each residue for the structures obtained from distance geometry calculations lead to the definition of four structural families in which the central segment 10-19 is always helical and differences refer to residues 8-9 and 19-23. A sequence analysis of the two ceratotoxins and a systematic search on the protein data bank revealed the occurrence of a KX-hydrophobic-hydrophobic-P motif that seems to be important for helix stabilization
Isospin effects in heavy-ion collisions: some results from CHIMERA experiments at LNS and perspectives with radioactive beams
CHIMERA is a 4Ï multidetector for charged particles available at Laboratori Nazionali del Sud (INFNâLNS). A new method to measure the time scale of the emission of nuclear fragments is described, together with some applications in the field of the isospin dynamics of heavyâion collisions. Competition between fusionâlike and binary reactions near the energy threshold for nuclear multifragmentation is discussed. Opportunities are pointed out to use the detector at low and intermediate energies using the kinematicalâcoincidence method