Search results for "Microscopy"

Subcellular distribution of choline acetyltransferase by immunogold electron microscopy in non-neuronal cells: Placenta, airways and murine embryonic…

2012

Abstract Aims Acetylcholine is synthesized in more or less all mammalian cells. However, little is known about the subcellular location of acetylcholine synthesis. Therefore, in the present experiments the subcellular location of the synthesizing enzyme choline acetyltransferase (ChAT) was investigated by anti-ChAT immunogold electron microscopy in human placenta and airways as well as in a murine embryonic stem cell line (CGR8 cell line). Main methods Human tissue was obtained as so-called surplus tissue (after delivery/surgical removal because of lung tumor); the CGR8 stem cell line was cultured under standard conditions. For human tissue a monoclonal mouse anti-ChAT antibody (ab) was use…

Solution processed pentacene thin films: new routes for building-up plastic field effect transistors

2008

Synthesis and processing of nanocrystalline tungsten carbide: Towards cemented carbides with optimal mechanical properties

2011

Abstract Nanocrystalline tungsten carbide has been obtained by reduction/carburization at low temperature from precursors obtained by freeze-drying of aqueous solutions. Nanocrystalline WC powders with a adequate content of carbon were mixed with submicrometric Cobalt powder (12 wt.%), obtained by same synthesis method, and sintered in vacuum furnace. The cemented carbides fabricated from experimental powders were compared with both commercial ultrafine and nanocrystalline WC-12Co mixtures consolidated by the same route. The synthesised powders were characterized by X-ray powder diffraction, elemental analysis and scanning and high resolution transmission electron microscopy. On the other h…

Localization of antigens PwA33 and La on lampbrush chromosomes and on nucleoplasmic structures in the oocyte of the urodele Pleurodeles waltl: Light …

1994

Monoclonal antibodies A33/22 and La11G7 have been used to study the distribution of the corre-sponding antigens, PwA33 and La, on the lampbrush chromosome loops and nucleoplasmic structures of P. waltl oocytes, using immunofluorescence, confocal laser scanning microscopy and immunogold labeling. The results obtained with these antibodies have been compared with those obtained with the Sm-antigen-specific monoclonal antibody Y12. All these monoclonal antibodies (mAbs) labeled the matrices of the majority of normal loops along their whole length. Nucleoplasmic RNP granules showed a strong staining with the mAbs La11G7 and Y12 throughout their mass, but with the mAb A33/22, they showed only a …

Lightfield microscopy, an emerging tool for real-time 3D imaging

2020

Integral, or lightfield, microscopy offers the possibility of capturing and processing in real time multiple views of 3D fluorescent samples captured with a single shot. In this contribution we review the recent advances in lightfield microscopy and enunciate the forthcoming challenges.

Quasi-spherical focal spot in two-photon scanning microscopy by three-ring apodization

2005

International audience; We present a beam-shaping technique for two-photon excitation (TPE) fluorescence microscopy. We show that by inserting a properly designed three-ring pupil filter in the illumination beam of the microscope, the effective optical sectioning capacity of such a system improves so that the point spread function gets a quasi-spherical shape. Such an improvement, which allows the acquisition of 3D images with isotropic quality, is obtained at the expense of only a small increase of the overall energy in the axial sidelobes. The performance of this technique is illustrated with a scanning TPE microscopy experiment in which the image of small beads is obtained. We demonstrat…

Resolution enhancement in integral microscopy by physical interpolation

2015

Integral-imaging technology has demonstrated its capability for computing depth images from the microimages recorded after a single shot. This capability has been shown in macroscopic imaging and also in microscopy. Despite the possibility of refocusing different planes from one snap-shot is crucial for the study of some biological processes, the main drawback in integral imaging is the substantial reduction of the spatial resolution. In this contribution we report a technique, which permits to increase the two-dimensional spatial resolution of the computed depth images in integral microscopy by a factor of √2. This is made by a double-shot approach, carried out by means of a rotating glass…

Fast multi-directional DSLM for confocal detection without striping artifacts

2020

In recent years light-sheet fluorescence microscopy (LSFM) has become a cornerstone technology for neuroscience, improving the quality and capabilities of 3D imaging. By selectively illuminating a single plane, it provides intrinsic optical sectioning and fast image recording, while minimizing out of focus fluorescence background, sample photo-damage and photo-bleaching. However, images acquired with LSFM are often affected by light absorption or scattering effects, leading to un-even illumination and striping artifacts. In this work we present an optical solution to this problem, via fast multi-directional illumination of the sample, based on an acousto-optical deflector (AOD). We demonstr…

Tunable axial superresolution by annular binary filters. Application to confocal microscopy

1995

We present a set of annular binary pupil filters for increasing the axial resolving capacity of imaging systems. The filters consist of two transparent annuli of the same area. It is shown that by changing the area of the transparent regions it is possible to obtain a tunable reduction of the width of the central lobe of the axial point spread function of the imaging system. However, this reduction is accompanied by a severe increase of the strength of secondary lobes, what can make these filters not very useful when used in conventional imaging systems. That is why we propose to use these filters for apodizing confocal microscopy systems. It is shown that in this case an important reductio…

Sidelobe decline in single-photon 4Pi microscopy by Toraldo rings.

2003

We demonstrate theoretically the feasibility of single-photon 4Pi-confocal microscopy. By inserting a pair of properly designed multi-ring phase-only pupil filters in the illumination path of a 4Pi microscope the height of the sidelobes of the point spread function substantially reduced, so that there is no ambiguity in the 3D image. Then, an axial resolution up to four times higher than that of single-photon confocal microscope can be effectively achieved.