Tailoring chiro-optical effects by helical nanowire arrangement.

In this work, we experimentally investigate the chiro-optical properties of 3D metallic helical systems at optical frequencies. Both single and triple-nanowire geometries have been studied. In particular, we found that in single-helical nanostructures, the enhancement of chiro-optical effects achievable by geometrical design is limited, especially with respect to the operation wavelength and the circular polarization conversion purity.

Thalamic fractional anisotropy predicts accrual of cerebral white matter damage in older subjects with small-vessel disease.

White matter hyperintensities (WMHs) and lacunes are magnetic resonance imaging hallmarks of cerebral small-vessel disease, which increase the risk of stroke, cognitive, and mobility impairment. Although most studies of cerebral small-vessel disease have focused on white matter abnormalities, the gray matter (GM) is also affected, as evidenced by frequently observed lacunes in subcortical GM. Diffusion tensor imaging (DTI) is sensitive to subtle neurodegenerative changes in deep GM structures.

[Squamous carcinoma of the anal canal and its variations. Personal experience and review of the literature].

Six cases of anal canal squamous carcinoma are presented. The authors precise the present view about pathological, epidemiological, clinical and therapeutical aspects of these lesions. They stress, also, the primary role of embryology and anatomy in the oncogenesis of such tumours; the importance to single out specific population at risk, absolutely different from the typical one for rectal adenocarcinoma and the role of chemoradiation therapy as treatment of choice of these neoplasms.