Search results for "Electron microscope"
showing 10 items of 784 documents
Self — Assembled System: Semiconductor and Virus Like Particles
2008
Virus like nanoparticles (VLP) are in use to be absorbed by cells to cause biological effects. To increase a local concentration of VLP, nanoparticles-carriers bringing the latter to the target cell could be employed. N-type and p-type Si semiconductor nanoparticles, to control adhesion of VLP were applied. Optical absorbance spectra and electron microscopy evidenced that VLP became connected to Si nanoparticles. Moreover, a density of the adhered VLP depended on the type of both semiconductor and VLP.
Self-Assembled System of Semiconductor and Virus Like Nanoparticles
2009
Virus like nanoparticles (VLP) are in use to be absorbed by cells to cause biological effects. To increase a local concentration of VLP, nanoparticles-carriers bringing the latter to the target cell could be employed. N-type and p-type Si semiconductor nanoparticles, to control adhesion of VLP were applied. Optical absorbance spectra and electron microscopy evidenced that VLP became connected to Si nanoparticles. Moreover, a density of the adhered VLP depended on the type of both semiconductor and VLP.
Reproducible optical fiber tips for photon scanning tunneling microscopy with very small (>5°) cone angle
1998
Sharp optical fiber tips for photon scanning tunneling microscopes (PSTMs) have been fabricated by employing a new alternative technique for etching multimode optical fibers. The tip diameter is less than 30 mm, while the cone full-angle can be as sharp as 3/spl deg/. To the knowledge of the authors, such tips are the sharpest reported up to now. Measurements, with 19 tips, of the evanescent wave decay distance produced by frustrated reflection of light on a same sample, show good reproducibility. Furthermore, the PSTM images, taken with the new tips, are very sharp and fit with images of the same sample obtained with an atomic force microscope (AFM).
Nature and origin of natural Zn clay minerals from the Bou Arhous Zn ore deposit: Evidence from electron microscopy (SEM-TEM) and stable isotope comp…
2016
International audience; Zn-clay minerals have been found in the non-sulfide deposit of Bou Arhous (High Atlas, Morocco). They occur as white or ochre clays embedding willemite (Zn2SiO4) and are commonly associated to red detrital clays in karstic cavities. Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD) and Transmission Electron Microscopy (TEM) with Energy Dispersive X-ray (EDX) analyses were combined in order to characterize the clay minerals and to determine the mechanism of their formation. XRD patterns on oriented and powdered clays and Fourier Transform Infrared (FTIR) spectroscopic analyses suggest that fraipontite is the major Zn clay phase (with some smectite interstrat…
Filipin labelling and intramembrane particles on the membranes of early and later autophagic vacuoles in Ehrlich ascites cells
1987
Cholesterol and intramembrane particle distribution on autophagic vacuole membranes was studied in Ehrlich ascites cells using filipin labelling and freeze-fracture electron microscopy. Unsaturated fatty acids were stained using imidazole-buffered osmium tetroxide. Autophagocytosis was induced with vinblastine, and early autophagic vacuoles were accumulated by lowering the ATP level in the cells with iodoacetate. Filipin labelling was observed in the limiting membranes of later, apparently hydrolase-containing autophagic vacuoles, whereas the most newly-formed, doublemembrane limited vacuoles were not labelled. The limiting membranes of late, residual body-type vacuoles either showed patchy…
Preparation and photoactivity of nanostructured TiO2 particles obtained by hydrolysis of TiCl4
2005
This work reports the preparation of nanostructured polycrystalline TiO2 photocatalysts obtained by hydrolysis of TiCl4 in very mild conditions. Several samples were prepared as suspensions or colloidal dispersions by using TiCl4/H2O volume ratios ranging between 1:1 and 1:100. The samples were characterised by X-ray diffraction analysis, specific surface area determination, diffuse reflectance spectroscopy and scanning electron microscopy. 4-Nitrophenol photodegradation was used as probe reaction to test the photoactivity of the catalysts. Some samples revealed a photoactivity higher than that of Degussa P25 in similar experimental conditions and the most photoactive one was that prepared …
Influence of low concentration acid treatment on lithium disilicate core/veneer ceramic bond strength
2013
Objective: This study evaluated the influence of low concentration acid treatment on the shear bond strength between lithium disilicate (LD) infrastructure and veneering porcelain. The surface morphology characteristic after this acid treatment was also examined. Study Design: LD reinforced ceramic cylinders (n=10) (IPS e.max Press, Ivoclar-Vivadent, Schaan, Liechtenstein) were treated (LD-treated) with a low concentration acid solution (Invex Liquid – Ivoclar-Vivadent, Schaan, Liechtenstein) or not treated with the acid solution (LD-untreated). They were veneered with a glass ceramic (IPS e.max Ceram, Ivoclar-Vivadent, Schaan, Liechtenstein). A metal ceramic group (CoCr) was tested as cont…
Effect of high power ultrasound on physical–chemical properties of polypropylene films aimed for food packaging: structure and surface features
2019
International audience; Biaxially oriented polypropylene (BOPP) coated with acrylic/polyvinylidene chloride (BOPPAcPVDC) and biaxially oriented coextruded polypropylene (BOPPcoex) films have been treated with high power ultrasound (HPUS) while submerged in water. Polymer structure and the surface morphology changes were noticed, and obtained results were correlated with the physical properties of tested materials. In anticipation of sonochemically enhanced reactions, physical–chemical profile of film samples was determined using thermogravimetric analysis, differential scanning calorimetry, Fourier-transform infrared spectroscopy, UV spectrophotometry and environmental scanning electron mic…
Halloysite nanotubes with fluorinated cavity: an innovative consolidant for paper treatment
2016
AbstractHybrid material based on halloysite nanotubes (HNTs) and sodium perfluorooctanoate (NaPF8) was used as a consolidant for paper treatment. The consolidation efficiency was determined by thermogravimetry as well as by paper grammage determination. Morphological analysis of the treated paper was performed by means of scanning electron microscopy while the effect of modified HNTs on the thermal behaviour of the cellulose fibres was investigated by differential scanning calorimetry which determined the combustion enthalpy of the paper.Water contact angle measurements were performed to study the paper wettability. The physico-chemical properties investigated (mesoscopic structure, thermal…
Unusual Intranuclear Inclusions in Malignant Fibrous Histiocytoma: Presence in Primary Tumor
1982
We describe previously unreported intranuclear inclusions in 2 cases of malignant fibrous histiocytoma. The inclusions were found in 2-10% of the tumor cells removed from the patients and in 2-10% of the cells examined in tumor tissue xenotransplanted in nude mice. By stereo electron microscopy the inclusions are closely packed undulating fibrils 18-23 nm in diameter. They are sometimes associated with fibrillary bodies. They closely resemble the inclusions reported in some animals inoculated with serum from patients with non-A non-B hepatitis; however, their nature at present is unknown.