Search results for " microscopy"

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…

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…

Capture and visualization of biological 3D samples through lightfield imaging and display techniques

2022

La microscopía óptica convencional proporciona imágenes de alta resolución de muestras microscópicas. Sin embargo, su escasa profundidad de campo y su falta de seccionado óptico hacen que sea inadecuada para la observación de especímenes tridimensionales. Para solucionar este problema, se han propuesto varias técnicas de microscopía 3D, la mayoría de ellas basadas en procedimientos de escaneo. La microscopía lightfield, en cambio, es una técnica de reciente desarrollo, que es capaz de capturar información 3D de muestras gruesas en una sola toma. Esto se consigue registrando de forma simultánea la información espacial y angular de los rayos procedentes de cada punto del objeto. Esta caracter…

High content and dispersion of Gd in bimodal porous silica: T2 contrast agents under ultra-high magnetic fields

2022

Silica-based UVM-7-type bimodal mesoporous materials with high gadolinium content (∞ ≥ Si/Gd ≥ 13) have been synthesized through a one-pot surfactant-assisted procedure from hydroalcoholic solution using a cationic surfactant as template, and starting from atrane complexes of Gd and Si as inorganic precursors. The novel synthetic pathway developed in the study preserves the UVM-7-type architecture while optimizing the dispersion of the Gd-guest species at the nanoscale and even at atomic level. It has been determined that the number of Gd atoms forming clusters is always less than 10. The behaviour under exposure to ultra-high magnetic fields reveals a significant increase in the transversa…

Spin Wave Emission from Vortex Cores under Static Magnetic Bias Fields

2021

We studied the influence of a static in-plane magnetic field on the alternating-field-driven emission of nanoscale spin waves from magnetic vortex cores. Time-resolved scanning transmission X-ray microscopy was used to image spin waves in disk structures of synthetic ferrimagnets and single ferromagnetic layers. For both systems, it was found that an increasing magnetic bias field continuously displaces the wave-emitting vortex core from the center of the disk toward its edge without noticeably altering the spin-wave dispersion relation. In the case of the single-layer disk, an anisotropic lateral expansion of the core occurs at higher magnetic fields, which leads to a directional rather th…