Effect of Aneurysm and Patient Characteristics on Intracranial Aneurysm Wall Thickness.

The circle of Willis is a network of arteries allowing blood supply to the brain. Bulging of these arteries leads to formation of intracranial aneurysm (IA). Subarachnoid hemorrhage (SAH) due to IA rupture is among the leading causes of disability in the western world.

Correlating Clinical Risk Factors and Histological Features in Ruptured and Unruptured Human Intracranial Aneurysms: The Swiss AneuX Study.

Pathogenesis of intracranial aneurysm is complex and the precise biomechanical processes leading to their rupture are uncertain. The goal of our study was to characterize the aneurysmal wall histologically and to correlate histological characteristics with clinical and radiological factors used to estimate the risk of rupture. A new biobank of aneurysm domes resected at the Geneva University Hospitals (Switzerland) was used.

Fate of the open-shell singlet ground state in the experimentally accessible acenes: A quantum Monte Carlo study.

By means of the Jastrow correlated antisymmetrized geminal power (JAGP) wave function and quantum Monte Carlo (QMC) methods, we study the ground state properties of the oligoacene series, up to the nonacene. The JAGP is the accurate variational realization of the resonating-valence-bond (RVB) ansatz proposed by Pauling and Wheland to describe aromatic compounds. We show that the long-ranged RVB correlations built in the acenes' ground state are detrimental for the occurrence of open-shell diradical or polyradical instabilities, previously found by lower-level theories.

Vertical and adiabatic excitations in anthracene from quantum Monte Carlo: Constrained energy minimization for structural and electronic excited-state properties in the JAGP ansatz.

We study the ionization energy, electron affinity, and the π → π(∗) ((1)La) excitation energy of the anthracene molecule, by means of variational quantum Monte Carlo (QMC) methods based on a Jastrow correlated antisymmetrized geminal power (JAGP) wave function, developed on molecular orbitals (MOs). The MO-based JAGP ansatz allows one to rigorously treat electron transitions, such as the HOMO → LUMO one, which underlies the (1)La excited state. We present a QMC optimization scheme able to preserve the rank of the antisymmetrized geminal power matrix, thanks to a constrained minimization with projectors built upon symmetry selected MOs.

The natural progression of adult elbow osteonecrosis related to corticosteroid treatment.

Background: In patients with corticosteroid treatment, the elbow is a rare site of osteonecrosis; there is little information about the rate and risk factors of disease progression in symptomatic and asymptomatic elbows.

Question/purposes: We determined the delay between the beginning of corticosteroid treatment and different stages of osteonecrosis and which stage and dose of steroids influenced disease progression.

Methods: Osteonecrosis related to corticosteroids was diagnosed by MRI in 50 elbows of 35 adult patients.

Alumina heads minimize wear and femoral osteolysis progression after isolated simple acetabular revision.

Background: Patients with THA requiring cup revision for acetabular osteolysis may have a stable stem component without loosening. However, it is unclear whether isolated cup revision halts femoral osteolysis progression.

Question/purposes: We asked (1) whether and to what degree osteolysis progresses after isolated acetabular revision with a change of the femoral head and (2) whether an alumina or metal bearing better reduces osteolysis progression and wear with a polyethylene (PE) cup.