Revealing hidden spin polarization in centrosymmetric van der Waals materials on ultrafast timescales.

One of the key challenges for spintronic and quantum technologies is to achieve active control of the spin angular momentum of electrons in nanoscale materials on ultrafast, femtosecond timescales. While conventional ferromagnetic materials and materials supporting spin texture suffer both from conceptional limitations in miniaturization and inefficiency of optical and electronic manipulation, non-magnetic centrosymmetric layered materials with hidden spin polarization may offer an alternative pathway to manipulate the spin degree of freedom by external stimuli. Here we demonstrate an approach for generating transient spin polarization on a femtosecond timescale in the otherwise spin-unpolarized band structure of the centrosymmetric 2H-stacked group VI transition metal dichalcogenide WSe2. Using ultrafast optical excitation of a fullerene layer grown on top of WSe2, we trigger an ultrafast interlayer electron transfer from the fullerene layer into the WSe2 crystal. The resulting transient charging of the C60/WSe2 interface leads to a substantial interfacial electric field that by means of spin-layer-valley locking ultimately creates ultrafast spin polarization without the need of an external magnetic field. Our findings open a novel pathway for true optical engineering of spin functionalities such as the sub-picosecond generation and manipulation of ultrafast spin currents in 2D heterostructures.

Puzzling over MDM4-p53 network.

MDM4 (also called MDMX) has been initially identified as p53 inhibitor. Subsequent data have reinforced this role pointing to the requirement for MDM4 repressive activity on p53 for mouse embryo development. Molecular studies have shown that MDM4 exerts different activities by controlling both p53 transcriptional function and protein levels. On the basis of these data, therapeutic strategies aiming at releasing p53 from MDM4 inhibition are under development. However, recent studies suggest a more complex relationship between MDM4 and p53. These have evidenced heterogeneity of MDM4 function under different growth conditions and particularly positive activity exerted by MDM4 on stress-activated p53 levels and pro-apoptotic function. This review summarizes the different facets of MDM4-mediated regulation of p53 and the modifications able to modulate MDM4 localization and function.

[Retrospective study of 135 cases of lung neoplasms diagnosed between 1983 and 1993]. / Studio retrospettivo su 135 casi di neoplasia polmonare diagnosticati dal 1983 al 1993.

The authors expose the results of a retrospective study concerning 135 cases of neoplasia diagnosed by their Department between 1983 and 1993. The patients' age, their sex, their consume of tobacco, their survival from the moment of the diagnosis have been considered in the study. Likewise the clinical instrumental researches and their reliability, the different incidence of the examined pathology in the first and in the second part of the period considered. It is emerged from the collected data, that also in our territory there is an increasing tendency in the incidence of lung neoplasia, a generally short survival after the diagnosis, a strong prevalence of smokers among those people affected from the disease, the difficulty of an early diagnosis due to scarce specificity of the commonest symptoms. The final auspicious is that a more incisive diligence in prevention and significant progresses in clinical pharmacological research may determine a notable reduction of the incidence of such a dramatic pathology.