Publications by authors named "G N J SOMMER"
This study aims to assess the outcomes of therapeutic options for aortic arch pathologies by comparing thoracic endovascular aortic repair (TEVAR) with open arch replacement (OAR) using woven polyester grafts from a mechanical and biomechanical perspective, with emphasis on ex vivo perfused human thoracic aortas reproducing heart rate and stroke volume conditions. Eleven non-diseased thoracic aortas from human cadavers were divided into TEVAR (n=5) and OAR (n=6) and tested using a custom-built mock circulation loop. Pressure, diameter, and stroke volume were monitored during perfusion before and after the intervention.
View Article and Find Full Text PDFThe brain is arguably the most complex human organ and modelling its mechanical behaviour has challenged researchers for decades. There is still a lack of understanding on how this multiphase tissue responds to mechanical loading and how material parameters can be reliably calibrated. While previous viscoelastic models with two relaxation times have successfully captured the response of brain tissue, the Theory of Porous Media provides a continuum mechanical framework to explore the underlying physical mechanisms, including interactions between solid matrix and free-flowing interstitial fluid.
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- Cystoscopy has long been the main method for detecting urothelial carcinoma (UCa), but its invasiveness and costs highlight the need for non-invasive detection methods, leading to the investigation of urinary biomarkers.
- In a study involving 1,119 urine samples, researchers analyzed protein levels of biomarkers CXCL16 and TGFBI, along with DNA methylation at specific CpG sites, to assess their ability to identify UCa compared to other urological and gynecological cancers.
- Results showed that while CXCL16 and TGFBI had moderate sensitivity (31% and 56%) and high specificity (94% and 85%), combining these proteins and methylation markers improved UCa detection sensitivity to 54%
Computational fluid dynamics (CFD) simulations have been introduced to enable individualized risk prognosis for patients with unruptured cerebral aneurysms. The present contribution provides an overview of the biomechanical and physiological principles of aneurysm formation and rupture. It describes the computational steps of the CFD and the evaluated parameters.
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- - Women can develop hypertension during the transition to menopause, with animal studies showing this condition linked to changes in NMDA receptors in the brain region responsible for regulating blood pressure.
- - Using an accelerated ovarian failure model, researchers discovered that hypertensive peri-menopausal female mice had higher levels of a crucial NMDA receptor subunit (GluN1) in the cytoplasm compared to male mice.
- - Activation of estrogen receptor beta (ERß) in peri-menopausal females not only diminished hypertension but also increased the presence of GluN1 in the cell membranes, unlike in male mice where ERß activation had no effect on blood pressure or GluN1 levels.