Search results for "Microscopy"

Rotational Correlation Functions of Single Molecules

2004

Single molecule rotational correlation functions are analyzed for several reorientation geometries. Even for the simplest model of isotropic rotational diffusion our findings predict non-exponential correlation functions to be observed by polarization sensitive single molecule fluorescence microscopy. This may have a deep impact on interpreting the results of molecular reorientation measurements in heterogeneous environments.

Phase separated Cu@Fe3O4 heterodimer nanoparticles from organometallic reactants

2011

Cu@Fe3O4 heteroparticles with distinct morphologies were synthesized from organometallic reactants. The shape of the magnetic domains could be controlled by the solvent and reaction conditions. They display magnetic and optical properties that are useful for simultaneous magnetic and optical detection. After functionalization, the Cu@Fe3O4 heterodimers become water soluble. The morphology, structure, magnetic and optical properties of the as-synthesized heterodimer nanoparticles were characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD), mossbauer spectroscopy, superconducting quantum interference device (SQUID) magnetometry, and dark field imaging. A special a…

Investigating spintronics thin film systems with synchrotron radiation

2009

Abstract Spintronics is a research field involving a wide variety of different magnetic materials. Synchrotron radiation in the VUV and soft X-ray regime is ideally suited to investigate the relationships between magnetic properties and electronic structure of spintronics thin film stacks. Complex layered structures and nanomagnets are the main building blocks for current and future spintronics applications. In this contribution we describe the study of spintronics model systems with respect to the static and dynamic behavior with an emphasis on interfaces.

Direct imaging of high frequency multimode spin wave propagation in cobalt iron waveguides using X ray microscopy beyond 10 GHz

2020

Nutriosomes: Prebiotic delivery systems combining phospholipids, a soluble dextrin and curcumin to counteract intestinal oxidative stress and inflamm…

2018

Nutriosomes, new phospholipid nanovesicles specifically designed for intestinal protection were developed by simultaneously loading a water-soluble dextrin (Nutriose® FM06) and a natural antioxidant (curcumin). Nutriosomes were easily fabricated in a one-step, organic solvent-free procedure. The stability and delivery performances of the vesicles were improved by adding hydroxypropyl methylcellulose. All the vesicles were small in size (mean diameter ∼168 nm), negatively charged (zeta potential ∼-38 mV, irrespective of their composition), and self-assembled predominantly in unilamellar vesicles stabilized by the presence of Nutriose®, which was located in both the inter-lamellar and inter-v…

β1 integrin signaling promotes neuronal migration along vascular scaffolds in the post-stroke brain

2017

Cerebral ischemic stroke is a main cause of chronic disability. However, there is currently no effective treatment to promote recovery from stroke-induced neurological symptoms. Recent studies suggest that after stroke, immature neurons, referred to as neuroblasts, generated in a neurogenic niche, the ventricular-subventricular zone, migrate toward the injured area, where they differentiate into mature neurons. Interventions that increase the number of neuroblasts distributed at and around the lesion facilitate neuronal repair in rodent models for ischemic stroke, suggesting that promoting neuroblast migration in the post-stroke brain could improve efficient neuronal regeneration. To move t…

Dopamine restores limbic memory loss, dendritic spine structure, and NMDAR-dependent LTD in the nucleus accumbens of alcohol-withdrawn rats

2018

Alcohol abuse leads to aberrant forms of emotionally salient memory, i.e., limbic memory, that promote escalated alcohol consumption and relapse. Accordingly, activity-dependent structural abnormalities are likely to contribute to synaptic dysfunctions that occur from suddenly ceasing chronic alcohol consumption. Here we show that alcohol-dependent male rats fail to perform an emotional-learning task during abstinence but recover their functioning byl-3,4-dihydroxyphenylalanin (l-DOPA) administration during early withdrawal.l-DOPA also reverses the selective loss of dendritic “long thin” spines observed in medium spiny neurons of the nucleus accumbens (NAc) shell of alcohol-dependent rats d…

A new insight into the three-dimensional architecture of the Golgi complex: Characterization of unusual structures in epididymal principal cells.

2017

Principal epididymal cells have one of the largest and more developed Golgi complex of mammalian cells. In the present study, we have used this cell as model for the study of the three-dimensional architecture of the Golgi complex of highly secretory and endocytic cells. Electron tomography demonstrated the presence in this cell type of some unknown or very unusual Golgi structures such as branched cisternae, pocket-like cisternal invaginations or tubular connections. In addition, we have used this methodology and immunoelectron microscopy to analyze the close relationship between this organelle and both the endoplasmic reticulum and microtubules, and to describe in detail how these element…

Interference with purinergic signalling

2016

Objective: The association of abacavir (ABC), a guanosine analogue, with cardiovascular toxicity is a long-lasting matter of controversy engendered by the lack of a mechanism of action. Clinical data point to an acute mechanism of vascular inflammation. Previous studies have shown that ABC induces leukocyte-endothelial cell interactions, an indicator of vascular inflammation. These effects are reproduced by another purine analogue, didanosine, but not by pyrimidine or acyclic nucleotide analogues, hinting at an interference with the purinergic system. The aim of the present study was to assess the role of ATP-receptors in leukocyte accumulation induced by ABC. Design and methods: Clinical c…

Podoplanin discriminates distinct stromal cell populations and a novel progenitor subset in the liver

2015

Podoplanin/gp38+ stromal cells present in lymphoid organs play a central role in the formation and reorganization of the extracellular matrix and in the functional regulation of immune responses. Gp38+ cells are present during embryogenesis and in human livers of primary biliary cirrhosis. Since little is known about their function, we studied gp38+ cells during chronic liver inflammation in models of biliary and parenchymal liver fibrosis and steatohepatitis. Gp38+ cells were analyzed using flow cytometry and confocal microscopy, and the expression of their steady state and inflammation-associated genes was evaluated from healthy and inflamed livers. Gp38+ cells significantly expanded in …