Direct quantification of the plasmon dephasing time in ensembles of gold nanorods through two-dimensional electronic spectroscopy.

In this study, we used two-dimensional electronic spectroscopy to examine the early femtosecond dynamics of suspensions of colloidal gold nanorods with different aspect ratios. In all samples, the signal distribution in the 2D maps at this timescale shows a distinctive dispersive behavior, which can be explained by the interference between the exciting field and the field produced on the nanoparticle's surface by the collective motion of electrons when the plasmon is excited. Studying this interference effect, which is active only until the plasmon has been dephased, allows for a direct estimation of the dephasing time of the plasmon of an ensemble of colloidal particles.

Coherent and Incoherent Ultrafast Dynamics in Colloidal Gold Nanorods.

The study of the mechanisms that control the ultrafast dynamics in gold nanoparticles is gaining more attention, as these nanomaterials can be used to create nanoarchitectures with outstanding optical properties. Here pump-probe and two-dimensional electronic spectroscopy have been synergistically employed to investigate the early ultrafast femtosecond processes following photoexcitation in colloidal gold nanorods with low aspect ratio. Complementary insights into the coherent plasmonic dynamics at the femtosecond time scale and incoherent hot electron dynamics over picosecond time scales have been obtained, including important information on the different sensitivity to the pump fluence of the longitudinal and transverse plasmons and their different contributions to the photoinduced broadening and shift.

Interinstitutional variation of caesarean delivery rates according to indications in selected obstetric populations: a prospective multicenter study.

The aim of the study was to identify which groups of women contribute to interinstitutional variation of caesarean delivery (CD) rates and which are the reasons for this variation. In this regard, 15,726 deliveries from 11 regional centers were evaluated using the 10-group classification system. Standardized indications for CD in each group were used.

[Maternal-fetal transmission of human papillomavirus].

Aim: Human papilloma virus (HPV) infection is one of the most frequently observed sexually-transmitted diseases (10-60% of the general population). In pregnant women, as well as accelerating the evolution of dysplasia to cervical cancer, the infection may be transmitted to the fetus during gestation or at the time of birth. Children who have been infected at birth may develop laryngeal papillomatosis during the first 5 years of life that may, in some cases, spread to the point of causing aphonia or severe respiratory obstruction.