Stercoral perforation of the sigmoid colon secondary to chronic heroin use: A case report and a review of the literature.

Introduction: Stercoral perforation of the colon is a rare and life-threatening condition caused by pressure necrosis due to fecal impaction. It is commonly associated with chronic constipation, particularly in patients with neurogenic bowel disorders or prolonged opioid use. However, its occurrence in the context of chronic heroin use is rarely reported.

Caecal perforation secondary to intrapelvic migration of a total hip prosthesis: A case report and a review of the literature.

Introduction: Total hip arthroplasty (THA) is commonly performed to alleviate hip pain and restore function. While generally safe, complications such as prosthesis migration can occur. Intrapelvic migration of hip prostheses, leading to bowel perforation and fistula formation, is a rare but severe complication requiring prompt diagnosis and management.

Bidimensional lamellar assembly by coordination of peptidic homopolymers to platinum nanoparticles.

A key challenge for designing hybrid materials is the development of chemical tools to control the organization of inorganic nanoobjects at low scales, from mesoscopic (~µm) to nanometric (~nm). So far, the most efficient strategy to align assemblies of nanoparticles consists in a bottom-up approach by decorating block copolymer lamellae with nanoobjects. This well accomplished procedure is nonetheless limited by the thermodynamic constraints that govern copolymer assembly, the entropy of mixing as described by the Flory-Huggins solution theory supplemented by the critical influence of the volume fraction of the block components.

The reversibility of phase transitions in Ti/Co core/shell nanometre-sized particles.

Molecular dynamics simulations have been employed to investigate the thermal response of unsupported Ti/Co core/shell particles with sizes between 2 and 10 nm. Co shells undergo a martensitic hcp-to-fcc phase transformation at temperatures dependent on the particle radius. Ti cores with radii of 2 nm or smaller also undergo the hcp-to-fcc transition.

Room-temperature self-assembly of equilateral triangular clusters via Friedel oscillations.

We report on the formation of equilateral triangular clusters hollow inside with 5-6 atoms per side, self-assembled on Ni adislands grown on Rh(111). The observation of standing wave patterns on the Ni adislands and the Rh(111) indicates that the self-assembly is mediated by Friedel oscillations. In this context, we propose a model based on the energy of interaction between adsorbates, which explains the formation of the clusters as a result of the assembly of rows of 5-6 adatoms.