The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
We report on a direct measurement of cation and anion sub-lattice strain in an InAs/GaSb type-II strained layer superlattice (T2SLs) using atomic resolution imaging and advanced image processing. Atomic column positions in InAs and GaSb are determined by separating the cation and anion peak intensities. Analysis of the InAs/GaSb T2SLs reveals the compressive strain in the nominal GaSb layer and tensile...
Degeneration of intervertebral disc (IVD) tissue is characterized by several structural changes that result in variations in disc physiology and loss of biomechanical function. The complex process of degeneration exhibits highly intercorrelated biomechanical, biochemical, and cellular interactions. There is currently some understanding of the cellular changes in degenerated intervertebral disc tissue,...
Electron beam irradiation is well known to induce damage in materials. The structural transformation involved in the damage is usually believed to be an irreversible solid state chemical reaction. Here we use in situ transmission electron microscopy (TEM) combined electron-energy loss spectroscopy (EELS) technique in an aberration-corrected TEM to track the structural transformation in spinel Mn3O...
Efficient drug delivery is critical to therapy. Using electron microscopy, X-ray, and light microscopy, we have characterized functionalized superparamagnetic iron oxide (SPIO) nanoparticles, and determined their ability for rapid entry and release of the cancer drug doxorubicin in human pancreatic cancer cells. Dextran-coated SPIO nanoparticle ferrofluid, functionalized with the red-autofluorescing...
Here, we present a method to investigate cell adhesion on soft, non-conducting polymers that are implant candidate materials. Neuronal cells were grown on two elastomers (polydimethylsiloxane (PDMS) and Ecoflex®) and prepared for electron microscopy. The samples were treated with osmium tetroxide (OsO4) and uranylacetate (UrAc). Best results can be achieved when the polymers were coated with a thin...
A concise derivation of the principle of reciprocity applied to realistic transmission electron microscopy setups is presented making use of the multislice formalism. The equivalence of images acquired in conventional and scanning mode is thereby rigorously shown. The conditions for the applicability of the found reciprocity relations is discussed. Furthermore the positions of apertures in relation...
The orientation of vascular canals in cortical bone can reveal information about the growth rate and loading environment of a bone. For example, in birds it has been proposed that a high proportion of circumferential canals (a laminar cortex) is related to fast growth or torsional loading related to active flight. In this paper we present a method to measure the three dimensional (3D) orientation...
The mouse serotonin 5-HT3A receptor is a homo-pentameric ligand-gated ion channel (pLGIC) mediating fast excitatory neurotransmission in the central nervous system. The molecular mechanism of ion permeation of 5‐HT3A receptors triggered by the neurotransmitter serotonin is not yet fully understood. The recent X-ray structure of the mouse serotonin 5-HT3A receptor in complex with a stabilizing nanobody...
The spatial resolution and the indexing quality obtained with an automated orientation and phase mapping tool are analyzed for different Transmission Electron Microscope (TEM) illumination settings. The electron probe size and convergence angle are studied for two TEM configuration modes referred as microprobe and nanoprobe modes. Using a 10μmC2 aperture in a FEI Tecnai F20 (S)TEM, the nanoprobe mode...
Force-distance curves have been acquired with an atomic force microscope on perfluorpolyether films. It is shown that curves acquired on films of different thickness, at different rates and with different dwell times can be overlapped by rescaling the time or distance axis. When the time or distance axis is rescaled, the force depends only on the surface tension of perfluorpolyether and on geometrical...
Many adult male spiders have silk glands which are not associated with the spinnerets. They occur on the anterior margin of the genital furrow and are used during the building of the sperm web and sperm droplet induction. These epiandrous glands exit the body through ducts which lead to specialized spigots. In the taxon Mygalomorphae, the presence of epiandrous spigots is just reported for a couple...
Non-biodegradable porous polystyrene (PS) scaffolds, composed of microfibers, have been prepared by electrospinning for the reconstruction of large bone defects. PS microfibers were prepared by incorporating β-TCP grains inside the polymer or grafting gold nanoparticles surface functionalized with mercaptosuccinic acid. Cytocompatibility of the three types of scaffolds (PS, β-TCP-PS and Au-PS) was...
This paper describes the effective solid angle improvement achieved using a large-area silicon drift detector together with a virtual-pivot double-tilt specimen holder. The virtual-pivot mechanism enables various designs of specimen-retaining and can reduce the shadowing effect. Energy-dispersive X-ray spectra were measured and converted into effective solid angles using different types of specimen...
Confocal micro-Raman spectroscopy was used to measure cross-section linescans of the cleaved edge of heterostructures involving a GaMnAs layer. The investigations revealed a shift of the TO mode in the compressed GaMnAs layer to high frequencies relative to the TO GaAs mode in the substrate and to low frequencies in the tensile GaMnAs layers. These results are in agreement with the different manifestations...
Negatively stained transmission electron microscope images are presented that depict the aggregation of recombinant anthrax protective antigen (rPA83 monomer and the PA63 prepore oligomer) under varying in vitro biochemical conditions. Heat treatment (50°C) of rPA83 produced clumped fibrils, but following heating the PA63 prepore formed disordered aggregates. Freeze-thaw treatment of the PA63 prepore...
Spectrum imaging techniques, gaining simultaneously structural (image) and spectroscopic data, require appropriate and careful processing to extract information of the dataset. In this article we introduce a MATLAB based software that uses three dimensional data (EEL/CL spectrum image in dm3 format (Gatan Inc.'s DigitalMicrograph®)) as input. A graphical user interface enables a fast and easy mapping...
Chromatoid body (CB) is a cytoplasmic structure of male germ cells that has been indicated as having a role in the RNA and protein storage for the final differentiation of spermatozoa. Recent studies have indicated that some of these macromolecular complex components have nucleolar origin. The aims of the present study were to monitor the expression of fibrillarin nucleolar protein in mammalian seminiferous...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.