In this study, we investigate the changes in the crystalline structure of MBE-deposited SrTiO layers on Si with different deviations from Sr/Ti stoichiometry as deposited but also after annealing at high temperatures (>600 °C). We show that as-grown 15 nm thick non-stochiometric SrTiO layers present surprisingly lower FWHM values of the (002) omega diffraction peak compared to fully stoichiometric layers of similar thickness. This can misleadingly point to superior crystalline quality of such non-stochiometric layers.
View Article and Find Full Text PDFIschemic stroke is a major global health issue and characterized by acute vascular dysfunction and subsequent neuroinflammation. However, the relationship between these processes remains elusive. In the current study, we investigated whether alleviating vascular dysfunction by restoring vascular nitric oxide (NO) reduces post-stroke inflammation.
View Article and Find Full Text PDFBroadband near-infrared light emitting tunnel junctions are demonstrated with efficient coupling to a silicon photonic waveguide. The metal oxide semiconductor devices show long hybrid photonic-plasmonic mode propagation lengths of approximately 10 μm and thus can be integrated into an overcoupled resonant cavity with quality factor ≈ 49, allowing for tens of picowatt near-infrared light emission coupled directly into a waveguide. The electron inelastic tunneling transition rate and the cavity mode density are modeled, and the transverse magnetic (TM) hybrid mode excitation rate is derived.
View Article and Find Full Text PDFCortical neurogenesis depends on the balance between self-renewal and differentiation of apical progenitors (APs). Here, we study the epigenetic control of AP's division mode by focusing on the enzymatic activity of the histone methyltransferase DOT1L. Combining lineage tracing with single-cell RNA sequencing of clonally related cells, we show at the cellular level that DOT1L inhibition increases neurogenesis driven by a shift of APs from asymmetric self-renewing to symmetric neurogenic consumptive divisions.
View Article and Find Full Text PDFPathologies of the brain microvasculature, often referred to as cerebral small-vessel disease, are important contributors to vascular dementia, the second most common form of dementia in aging societies. In addition to their role in acute ischemic and hemorrhagic stroke, they have emerged as major cause of age-related cognitive decline in asymptomatic individuals. A central histological finding in these pathologies is the disruption of the vessel architecture including thickening of the vessel wall, narrowing of the vessel lumen and massive expansion of the mural extracellular matrix.
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