Emergent Dirac Fermions in Epitaxial Planar Silicene Heterostructure.

Silicene, a single layer of Si atoms, shares many remarkable electronic properties with graphene. So far, silicene has been synthesized in its epitaxial form on a few surfaces of solids. Thus, the problem of silicene-substrate interaction appears, which usually depresses the original electronic behavior but may trigger properties superior to those of bare components. We report the direct observation of robust Dirac-dispersed bands in epitaxial silicene grown on Au(111) films deposited on Si(111). By performing in-depth angle-resolved photoemission spectroscopy measurements, we reveal three pairs of one-dimensional bands with linear dispersion running in three different directions of an otherwise two-dimensional system. By combining these results with first-principles calculations, we explore the nature of these bands and point to strong interaction between subsystems forming a complex Si-Au heterostructure. These findings emphasize the essential role of interfacial coupling and open a unique materials platform for exploring exotic quantum phenomena and applications in future-generation nanoelectronics.

Peculiar Structural Phase of a Single-Atom-Thick Layer of Antimony.

Using molecular beam epitaxy, a new structural phase of a single atom thick antimony layer has been synthesized on the W(110) surface. Scanning tunneling microscopy measurements reveal an atomically resolved structure with a perfectly flat surface and unusually large unit cell. The structure forms a well-ordered continuous film with a lateral size in the range of several millimeters, as revealed by low energy electron microscopy and diffraction experiments. The results of density functional theory calculations confirm the formation of a new phase of single-atom-thick antimony film without the buckling characteristic for the known phases of antimonene. The presented results demonstrate a substrate-tuned approach in the preparation of new structural phases of 2D materials.

A Case Report of Monkeypox in an Adult Patient from Italy: Clinical and Dermoscopic Manifestations, Diagnosis and Management.

Monkeypox infection is an emerging problem and a new challenge for modern medicine. With an increasing number of new cases worldwide, new data regarding the clinical manifestations, characteristics of the patients, risk factors and treatment options are coming to light. Knowing more about the disease will allow to elaborate new helpful methods to facilitate its diagnosis. Special attention should be paid to the careful dermatologic and dermoscopic examination of the patient. The analysis of available data also suggests possible strategies for the prevention of Monkeypox virus spread; the vaccine against Smallpox seems to be an effective solution. This case report describes the diagnostic approach and management of a non-vaccinated adult patient with several risk factors and a history of sexually transmitted disease. The patient had no history of travel abroad. Even though a clinical diagnose of Monkeypox can be challenging due to its similarities with skin rashes caused by other Orthopoxviral infections, there are fine differences between the rashes which can be helpful in their differentiation, although laboratory analysis is required for a definitive identification. A careful study of the characteristics of the rash, such as diameter, its presence on palms and soles and its evolution in time, provided important clues for the diagnosis of Monkeypox infection. The lack of vaccinations in the history of the patient was another crucial finding in the diagnostic process.

Dupilumab facial redness: histologic characterization on a series of four cases.

Dupilumab-related head and neck dermatitis is an increasingly reported clinical manifestation occurring in 4-10% of patients on dupilumab that was apparently not reported in clinical trials. Out of 62 adult patients treated with dupilumab for atopic dermatitis in the authors' center, four cases (6%) of head and neck dermatitis were observed, for which a skin biopsy was obtained. Onset occurred between 8 and 24 weeks after initiation of dupilumab, and the reaction resolved after 8-12 weeks. Histopathology and immunohistochemical findings support the authors' hypothesis that facial redness may be a toxic effect induced by dupilumab, although its pathogenesis still requires further investigation.

Plain language summary Dupilumab is an advanced treatment for atopic dermatitis. The new appearance of a peculiar head and neck dermatitis may be observed in as many as 4­10% of subjects receiving this drug, though it was not reported in the course of the clinical trials that led to the approval of dupilumab. Out of 62 adults treated with dupilumab for atopic dermatitis in the authors' Dermatology Clinic, four subjects (6%) were observed to have head and neck dermatitis. The condition appeared between 8 and 24 weeks after initiation of dupilumab and lasted 8­12 weeks. The four subjects gave permission to perform a skin biopsy. Microscopic analysis of their samples suggested that this peculiar facial redness may be a drug-induced reaction associated with dupilumab, although its causes and mechanisms still require understanding.

Magnetism in Au-Supported Planar Silicene.

The adsorption and substitution of transition metal atoms (Fe and Co) on Au-supported planar silicene have been studied by means of first-principles density functional theory calculations. The structural, energetic and magnetic properties have been analyzed. Both dopants favor the same atomic configurations with rather strong binding energies and noticeable charge transfer. The adsorption of Fe and Co atoms do not alter the magnetic properties of Au-supported planar silicene, unless a full layer of adsorbate is completed. In the case of substituted system only Fe is able to produce magnetic ground state. The Fe-doped Au-supported planar silicene is a ferromagnetic structure with local antiferromagnetic ordering. The present study is the very first and promising attempt towards ferromagnetic epitaxial planar silicene and points to the importance of the substrate in structural and magnetic properties of silicene.

Structural model of silicene-like nanoribbons on a Pb-reconstructed Si(111) surface.

A structural model of the recently observed silicene-like nanoribbons on a Pb-induced √3 × âˆš3 reconstructed Si(111) surface is proposed. The model, which is based on first principles density functional theory calculations, features a deformed honeycomb structure directly bonded to the Si(111) surface underneath. Pb atoms stabilize the nanoribbons, as they passivate the uncovered substrate, thus lower the surface energy, and suppress the nanoribbon-substrate interaction. The proposed structural model reproduces well all the experimental findings.