In this work, we consider the physical basis of deformation and fracture in layered composite nanocrystalline/amorphous material-low-melting crystalline alloy in a wide temperature range. Deformation and fracture at the crack tip on the boundary of such materials as nanocrystalline alloy of the trademark 5BDSR, amorphous alloy of the trademark 82K3XSR and low-melting crystalline alloy were experimentally investigated. The crack was initiated by uniaxial stretching in a temperature range of 77-293 K.
View Article and Find Full Text PDFZh Vopr Neirokhir Im N N Burdenko
October 2023
Background: Pathogenesis of peritumoral cerebral edema is unclear and potentially associated with glymphatic system dysfunction. Diffusion tensor MRI (DT-MRI) with analysis of ALPS (Analysis along the Perivascular Space) index may be valuable for assessment of edema. This approach visualizes fluid flow along perivascular spaces of deep cerebral veins.
View Article and Find Full Text PDFZh Vopr Neirokhir Im N N Burdenko
September 2023
Unlabelled: Background. Meningiomas may be accompanied by peritumoral edema. Incidence and pathogenesis of edema are nor clearly established.
View Article and Find Full Text PDFIntroduction: Cerebral autoregulation is an essential mechanism for maintaining cerebral blood flow stability. The phenomenon of transtentorial intracranial pressure (ICP) gradient after neurosurgical operations, complicated by edema and intracranial hypertension in the posterior fossa, has been described in clinical practice but is still underinvestigated. The aim of the study was to compare autoregulation coefficients (i.
View Article and Find Full Text PDFIn patients with severe traumatic brain injury (TBI), simultaneous measurement of intracranial and arterial blood pressure (ICP and ABP, respectively) allows monitoring of cerebral perfusion pressure (CPP) and the assessment of cerebral autoregulation (CA). CPP, a difference between ICP and ABP, is the pressure gradient that drives oxygen delivery to cerebral tissue. CA is the ability of cerebral vasculature to maintain stable blood flow despite changes in CPP and thus, is an important homeostatic mechanism.
View Article and Find Full Text PDF