Search results for "Microscope"
showing 10 items of 1412 documents
The effect of composite resin preheating on marginal adaptation of class II restorations
2020
Background One of the problems with a high filler content composite resins is gap formation at restorative material-tooth interface. The present study investigated the effect of preheating composite resins on the formation of marginal gap in Cl II restorations. Material and Methods In this in vitro study Sixty Cl II cavities were prepared on the mesial and distal surfaces of 30 extracted premolar teeth. The gingival floor of cavities was placed 1 m below the CEJ. The samples were randomly allocated to 4 groups for restoration placement: group 1, Filtek P60 composite resin at room temperature; group 2, Filtek P60 composite resin at 68°C; group 3, X-tra fil composite resin at room temperature…
Abrupt elastic-to-plastic transition in pentagonal nanowires under bending
2019
MD modeling and calculations were supported by Russian Science Foundation project grant 18-19-00645 “Adhesion of polymer-based soft materials: from liquid to solid”; mechanical testing and FEM simulations were supported by Estonian Research Council projects PUT1689 and PUT1372.
Relationships between absence of functional swimbladder, calculosis and larval mortality in hatcheryreared gilthead sea bream, Sparus aurata L.
1993
Abstract. The relationship between absence of functional swim-bladder, calculosis and larval mortality of hatchery-reared sea bream, Sparus aurata L., was observed. There was a temporal variation in the main causes of mortality, i.e. not inflated swim-bladder appears to be the main cause up to the 47th day, and the presence of calculi around the 55th day. Histological sections, semi-quantitative analysis and scanner electron microscope photographs were carried out.
The effect of mechanical defects on the strength distribution of elementary flax fibres
2009
Flax fibres are finding non-traditional applications as reinforcement of composite materials. The mechanical properties of fibres are affected by the natural variability in plant as well as the damage accumulated during processing, and thus have considerable variability that necessitates statistical treatment of fibre characteristics. The strength distribution of elementary flax fibres has been determined at several fibre lengths by standard tensile tests, and the amount of kink bands in the fibres evaluated by optical microscopy. Strength distribution function, based on the assumption that the presence of kink bands limits fibre strength, is derived and found to provide reasonable agreemen…
Advanced fluorescence microscopy for in vivo imaging of neuronal activity
2019
Brain function emerges from the coordinated activity, over time, of large neuronal populations placed in different brain regions. Understanding the relationships of these specific areas and disentangling the contributions of individual neurons to overall function remain central goals for neuroscience. In this scenario, fluorescence microscopy has been proved as the tool of choice for in vivo recording of brain activity. Optical advances combined with genetically encoded indicators allow a large flexibility in terms of spatiotemporal resolution and field of view while keeping invasiveness in living animals to a minimum. Here we describe the latest advancements in the field of linear and nonl…
A method to identify biological aerosol particles with radius > 0.3μmfor the determination of their size distribution
1991
Abstract The relevance of biological aerosol will be demonstrated. A method to determine the sizedistribution of the biological aerosols is shown, which gives the opportunity to determine a lower limit of the biological particles. For evaluation a light microscope and a scanning electron microscope equipped with an energy dispersive x-ray spectrometer are used.
Applications of Super Resolution Expansion Microscopy in Yeast
2021
Super-resolution microscopy includes multiple techniques in optical microscopy that enable sub-diffraction resolution fluorescence imaging of cellular structures. Expansion microscopy (EXM) is a method of physical expansion to obtain super-resolution images of a biological sample on conventional microscopy. We present images of yeast organelles, applying the combination of super-resolution and ExM techniques. When preparing pre-expanded samples, conventional methods lead to breakage of dividing yeast cells and difficulties in studying division-related proteins. Here, we describe an improved sample preparation technique that avoids such damage. ExM in combination with Airyscan and structured…
First Specifications of a PSTM Working In the Infrared
1993
One of the most promising extension of the photon scanning tunneling microscope (PSTM) is its use as a locally resolved spectroscopic tool. The infrared (IR) spectral window offers a wide variety of interesting applications since many materials have a well-defined signature in this range. We have undertaken the experimental modifications that are necessary to operate the existing PSTM’s in the IR domain. In this work, we present preliminary data obtained with two IR light sources: an extended source (Globar type) and the free electron IR laser source (CLIO) available at LURE (Orsay). In both cases, the evanescent field has been detected with a fluoride glass optical fiber and the characteri…
The Gelling Ability of Some Diimidazolium Salts: Effect of Isomeric Substitution of the Cation and Anion
2013
The gelling ability of some geminal imidazolium salts was investigated both in organic solvents and in water solution. Organic salts differing either in the cation or anion structure were taken into account. In particular, the effects on the gel-phase formation of isomeric substitution on the cation or anion as well as of the use of mono- or dianions were evaluated. As far as the cation structure is concerned, isomeric cations, such as 3,3′-di-n-octyl-1,1′-(1,4-phenylenedimethylene)diimidazolium and 3,3′-di-n-octyl-1,1′-(1,3-phenylenedimethylene)diimidazolium, were used. On the other hand, in addition to the bromide anion, isomeric dianions, such as the 1,5- and 2,6-naphthalenedisulfonate a…
Chiral charge order in the superconductor 2H-TaS(2)
2011
Artículo escrito por un elevado número de autores, solo se referencian el que aparece en primer lugar, el nombre del grupo de colaboración, si le hubiere, y los autores pertenecientes a la UAM