Search results for "Microscopy"

Localization of GFP-Tagged Proteins at the Electron Microscope

2016

Flussquantifizierung in Koronar- und Bypass- gefäßen mit der MR-Phasenkontrasttechnik

2000

Ziel: Es sollte die Genauigkeit der MR-Phasenkontrastmethode zur Ermittlung des Flusses in Koronararterien und koronaren Bypassgefasen bestimmt werden. Material und Methode: Die MRT-Flussmessungen von 12 Patienten mit 22 Bypassgefasen wurden mit intraoperativ mittels Ultraschalldurchflussmethode bestimmten Flussen verglichen. Praoperativ wurden zusatzlich Flussmessungen in 28 Koronararterien von 20 Patienten durchgefuhrt. Zur MRT-Flussmessung wurde eine segmentierte 2D-Flash-Sequenz verwendet, die eine zeitliche Auflosung von 110 bzw. 125 ms aufwies. Dies ermoglichte die Akquisition von 6–8 Bildpaaren pro Herzzyklus. Ergebnisse: Es bestand eine signifikante Korrelation zwischen den Ergebnis…

Microhydrological Niches in Soils: How Mucilage and EPS Alter the Biophysical Properties of the Rhizosphere and Other Biological Hotspots

2019

Plant roots and bacteria are capable of buffering erratic fluctuations of water content in their local soil environment by releasing a diverse, highly polymeric blend of substances (e.g. extracellular polymeric substances [EPS] and mucilage). Although this concept is well accepted, the physical mechanisms by which EPS and mucilage interact with the soil matrix and determine the soil water dynamics remain unclear. High-resolution X-ray computed tomography revealed that upon drying in porous media, mucilage (from maize [Zea mays L.] roots) and EPS (from intact biocrusts) form filaments and two-dimensional interconnected structures spanning across multiple pores. Unlike water, these mucilage a…

Structural characterization of site-modified nanocapsid with monodispersed gold clusters

2017

AbstractHepatitis E Virus-like particles self-assemble in to noninfectious nanocapsids that are resistant to proteolytic/acidic mucosal delivery conditions. Previously, the nanocapsid was engineered to specifically bind and enter breast cancer cells, where successful tumor targeting was demonstrated in animal models. In the present study, the nanocapsid surface was modified with a solvent-exposed cysteine to conjugate monolayer protected gold nanoclusters (AuNC). Unlike commercially available gold nanoparticles, AuNCs monodisperse in water and are composed of a discrete number of gold atoms, forming a crystalline gold core. Au102pMBA44 (Au102) was an ideal conjugate given its small 2.5 nm s…

The cell nucleus. A study in Burgundy

2019

ABSTRACT Wilhelm Bernhard’s revolutionary microscopy techniques helped him put forward the hypothesis of specialized compartmentalization of the nucleus. He also described for the first time the nuclear bodies and peri-chromatin fibrils, and demonstrated that these granules contain an RNA component. The tradition of biennial workshops, named after this great scientist, continues, and this year it took place in the heart of Burgundy, in Dijon, France (May 20–24, 2019, organized by INSERM UMR1231, UBFC), where well-fed participants emphasized the importance of viewing the cell nucleus as a hub of specialized colloidal compartments that orchestrate replication, transcription and nuclear transp…

Surface Morphology of Single and Multi-Layer Silicon Nitride Dielectric Nano-Coatings on Silicon Dioxide and Polycrystalline Silicon

2019

Silicon nitride (Si3N4) in a form of single and multi-layer nanofilms is proposed to be used as a dielectric layer in nanocapacitors for operation in harsh environmental conditions. Characterization of surface morphology, roughness and chemical bonds of the Si3N4 coatings has an important role in production process as the surface morphology affects the contact surface with other components of the produced device. Si3N4 was synthesized by using low pressure chemical vapour deposition method and depositing single and multi-layer (3 – 5 layers) nanofilms on SiO2 and polycrystalline silicon (PolySi). The total thickness of the synthesized nanofilms was 20 – 60 nm. Surface morphology was investi…

Application of Tuning Fork Sensors for In-situ Studies of Dynamic Force Interactions Inside Scanning and Transmission Electron Microscopes

2012

Mechanical properties of nanoscale contacts have been probed in-situ by specially developed force sensor based on a quartz tuning fork resonator (TF). Additional control is provided by observation of process in scanning electron microscope (SEM) and transmission electron microscope (TEM). A piezoelectric manipulator allows precise positioning of atomic force microscope (AFM) probe in contact with another electrode and recording of the TF oscillation amplitude and phase while simultaneously visualizing the contact area in electron microscope. Electrostatic control of interaction between the electrodes is demonstrated during observation of the experiment in SEM. In the TEM system the TF senso…

Detection of an endophytic Acremonium sp. in healthy or naturally damaged leaves of Vitis vinifera.

2003

Influence of Nanoparticle Exposure on Nervous System Development in Zebrafish Studied by Means of Light Sheet Fluorescence Microscopy

2016

Zebrafish has a remarkable similarity in the molecular signaling processes, cellular structure, anatomy and physiology to other higher order vertebrates, making it an excellent vertebrate model organism (1). Recently, zebrafish has been used for neurotoxicity screening of numerous nanomaterials with a focus on the developmental effects due to the possibility of in vivo visualization of specific neurons and axon tracts by injecting dyes in live animals as well in fixed ones (2). Here we propose Light Sheet Fluorescence Microscopy (LSFM) (3) (4) to perform neurotoxicity studies, in order to study the nervous system architecture and to image 3D structures in the brain of live larvae during the…

A Novel Fast Volumetric Light Sheet Microscopy

2016

Fast noninvasive three-dimensional (3D) imaging is crucial for the quantitative understanding of highly dynamic biological processes. Over the last decades, several fluorescence microscopy techniques have been developed in order to provide a faster and deeper imaging of thick biological samples [1]. Within this framework, Light Sheet Fluorescence Microscopy (LSFM) has emerged as a powerful imaging tool for 3D imaging of thick samples ranging from single cells to entire animals [2,3].However, to obtain a 3D reconstruction either sample or microscope parts usually need to be moved limiting the acquisition speed and inducing possible interferences in volume recording. To solve this problem, he…