ABSTRACT
We report the first evidence of Raman scattering from surface phonons of a pristine metal surface. Our study reveals a Raman-active surface vibrational resonance on Cu(110) with a surprisingly large scattering efficiency. With the incident photon energy close to the energy of the Cu(110) surface state electronic transition, the Raman scattering from the surface optical resonance can be significantly enhanced, while any contribution from bulk phonons is absent.
ABSTRACT
Density-functional theory is used to explore the Si(553)-Au surface dynamics. Our study (i) reveals a complex two-stage order-disorder phase transition where with rising temperature first the ×3 order along the Si step edges and, subsequently, the ×2 order of the Au chains is lost, (ii) identifies the transient modification of the electron chemical potential during soft Au chain vibrations as instrumental for disorder at the step edge, and (iii) shows that the transition leads to a self-doping of the Si dangling-bond wire at the step edge. The calculations are corroborated by Raman measurements of surface phonon modes and explain previous electron diffraction, scanning tunneling microscopy, and surface transport data.
ABSTRACT
BACKGROUND: The increasing use of immunotherapy in oncology increases the need for radiologic evaluation of frequent and severe immune-related adverse events. OBJECTIVE: Determination of the incidence and manifestation of radiologic and nuclear medicine findings of immune-related adverse events. MATERIAL AND METHODS: Literature review of clinical and imaging findings of immune-related adverse events induced by the immune checkpoint inhibitors ipilimumab, nivolumab and pembrolizumab. Findings are illustrated with pictorial examples and contrasted to other relevant differential diagnoses. RESULTS: The most frequent imaging manifestations are colitis, hepatitis, pancreatitis, hypophysitis, pneumonitis, arthritis and sarcoid-like lymphadenopathy. Severe to life-threatening complications may result from colitis, pneumonitis and hypophysitis. A clear differentiation from other autoimmune diseases and discrimination of immune-related and infectious pulmonary findings can be very difficult and need close multidisciplinary collaboration. CONCLUSION: Knowledge of clinical and imaging findings of adverse events induced by immunotherapy is essential for timely and adequate therapeutic decisions. In addition to staging and follow-up imaging, identification and monitoring of immune-related adverse events adds to the radiologic responsibility in oncologic care.
