0000000000623117
AUTHOR
M. Piscopo
Be7(n,α)He4Reaction and the Cosmological Lithium Problem: Measurement of the Cross Section in a Wide Energy Range at n_TOF at CERN
The energy-dependent cross section of the (7)Bed(n,alpha)He-4 reaction, of interest for the so-called cosmological lithium problem in big bang nucleosynthesis, has been measured for the first time from 10 meV to 10 keV neutron energy. The challenges posed by the short half-life of Be-7 and by the low reaction cross section have been overcome at n_TOF thanks to an unprecedented combination of the extremely high luminosity and good resolution of the neutron beam in the new experimental area (EAR2) of the n_TOF facility at CERN, the availability of a sufficient amount of chemically pure Be-7, and a specifically designed experimental setup. Coincidences between the two alpha particles have been…
Chromatin Maturity Index (CMI) in unfixed and live spermatozoa and Aniline Blue (AB) stained as an additional evaluation parameter in idiopathic male infertility
Study question: To investigate whether idiopathic male infertility may be due to the presence of histones in motile spermatozoa using a modified AB staining protocol. Summary answer: No correlation between CMI in live motile spermatozoa, DNA Fragmentation Index (DFI) and other conventional seminal parameters were found in male infertile patients. What is known already: The AB stain discriminates between lysine-rich histones and arginine/cysteine-rich protamines. Transition from histones to protamines during spermatogenesis remodels chromatin packaging and abnormalities in the substitution of those proteins maybe interfere with seminal parameters and affect male infertility. The correlation …