Ultrafast Low-Energy Photoelectron Diffraction for the Study of Surface-Adsorbate Interactions with 100-fs Temporal Resolution.

A novel method of ultrafast electron diffraction for the study of structural dynamics at surfaces is presented. The probing electron pulse is generated in the immediate vicinity of the surface by photoemission of low-energy electrons from the sample substrate. This limits the propagation distance of the electron pulse before diffraction to a few nanometers and thus minimizes pulse broadening effects due to space charge and dispersion.

Comparison of Anthropometric and Cephalometric Measurements Obtained by Stereophotogrammetry and 3D Computed Tomography of the Nose Before Septorhinoplasty.

Introduction: Computed tomography (CT) is normally used in evaluation of patients with esthetic and functional nasal deformities. Stereophotogrammetry (SPG) is a measurement device that is an alternative to CT and does not harm human health. In this single-center retrospective study, we aimed to evaluate measurements obtained with CT and SPG.

Semicircular canals are long in patients with benign paroxysmal positional vertigo.

Objective: To search for any morphological variation contributing to aetiopathogenesis and the diagnosis of benign paroxysmal positional vertigo, we measured the sizes of the semicircular canals in patients with and without benign paroxysmal positional vertigo using multidetector computed tomography.

Methods: Cranial bone computed tomography images of 30 benign paroxysmal positional vertigo patients and 30 control patients were acquired with a 128-slice computed tomography scanner and a transverse plane with a thickness of 0.67 mm.

Visceral to subcutaneous fat ratio predicts short-term mortality in patients with Covid 19. A multicenter study.

Objective: To evaluate the association of body composition parameters with outcomes in Covid-19.

Methods: 173 patients hospitalized for Covid-19 infection in 6 European centers were included in this retrospective study. Measurements were performed at L3-level and comprised skeletal muscle index (SMI), muscle density (MD), and adipose tissue measurements [visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), intramuscular adipose tissue (IMAT), visceral-to-subcutaneous-adipose-tissue-area-ratio (VSR)].

Observation of electronic structure replicas in photoemission spectra of graphite upon adsorption of tin phthalocyanine.

Cone-type bands near the center of the surface Brillouin zone were observed in low-energy angle-resolved photoemission spectra of tin phthalocyanine adsorbed on graphite. Simulations in comparison with the experimental data show that the spectral features represent replicas of the electronic structure of graphite nearK‾resulting from high-order momentum transfer processes up to the fourth order owing to the interaction of substrate electrons with the long-range structural order of the adsorbate overlayer. The analysis of time-resolved photoemission data from one of the replicas yields a quantitative and very good agreement with previous studies on the excited carrier dynamics in the Dirac cones of graphite and graphene.