Search results for "Microscope"
showing 10 items of 1412 documents
Dual-mode holographic microscopy imaging platform
2018
We report on a novel layout capable of dual-mode imaging in real time with different magnifications and resolution capabilities in lensless microscopy. The concept is based on wavelength multiplexing for providing two illuminations with different wavefront curvatures: one is collimated, allowing a large field of view (FOV) with a poor resolution limit, and the other is divergent, to achieve a better resolution limit (micron range) over a small FOV. Moreover, our recently reported concept of MISHELF microscopy [M. Sanz, J. Á. Picazo-Bueno, L. Granero, J. García and V. Micó, Sci. Rep., 2017, 7, 43291] is applied to the divergent illumination case, improving the image quality by noise averagin…
Comparative morphological characteristics of three Brettanomyces bruxellensis wine strains in the presence/absence of sulfur dioxide
2016
International audience; The red wine spoilage yeast Brettanomyces bruxellensis has been the subject of numerous investigations. Some of these studies focused on spoilage mechanisms, sulfur dioxide tolerance and nutrient requirements. Pseudomycelium formation, although a striking feature of this species, has however been poorly investigated. Furthermore, literature regarding the induction mechanism of pseudomycelium formation in this yeast is limited and lacks clarity, as results published are contradictory. This study elucidates this phenomenon among strains from geographically different areas. Potential environmental cues were investigated, to attain a better understanding of this mechanis…
Herpes simplex virus 1 induces egress channels through marginalized host chromatin
2016
AbstractLytic infection with herpes simplex virus type 1 (HSV-1) induces profound modification of the cell nucleus including formation of a viral replication compartment and chromatin marginalization into the nuclear periphery. We used three-dimensional soft X-ray tomography, combined with cryogenic fluorescence, confocal and electron microscopy, to analyse the transformation of peripheral chromatin during HSV-1 infection. Our data showed an increased presence of low-density gaps in the marginalized chromatin at late infection. Advanced data analysis indicated the formation of virus-nucleocapsid-sized (or wider) channels extending through the compacted chromatin of the host. Importantly, co…
Age‐related ultrastructural changes of the basement membrane in the mouse blood‐brain barrier
2018
Abstract The blood‐brain barrier (BBB) is essential for a functional neurovascular unit. Most studies focused on the cells forming the BBB, but very few studied the basement membrane (BM) of brain capillaries in ageing. We used transmission electron microscopy and electron tomography to investigate the BM of the BBB in ageing C57BL/6J mice. The thickness of the BM of the BBB from 24‐month‐old mice was double as compared with that of 6‐month‐old mice (107 nm vs 56 nm). The aged BBB showed lipid droplets gathering within the BM which further increased its thickness (up to 572 nm) and altered its structure. The lipids appeared to accumulate toward the glial side of the BM. Electron tomography …
Flow Cytometric Analysis of the Expression Pattern of Peroxisomal Proteins, Abcd1, Abcd2, and Abcd3 in BV-2 Murine Microglial Cells
2017
Microglial cells play important roles in neurodegenerative diseases including peroxisomal leukodystrophies. The BV-2 murine immortalized cells are widely used in the context of neurodegenerative researches. It is therefore important to establish the expression pattern of peroxisomal proteins by flow cytometry in these cells. So, the expression pattern of various peroxisomal transporters (Abcd1, Abcd2, Abcd3) contributing to peroxisomal β-oxidation was evaluated on BV-2 cells by flow cytometry and complementary methods (fluorescence microscopy, and RT-qPCR). By flow cytometry a strong expression of peroxisomal proteins (Abcd1, Abcd2, Abcd3) was observed. These data were in agreement with tho…
E-beam crosslinked nanogels conjugated with monoclonal antibodies in targeting strategies
2017
Abstract Poly(N-vinyl pyrrolidone)-based-nanogels (NGs), produced by e-beam irradiation, are conjugated with monoclonal antibodies (mAb) for active targeting purposes. The uptake of immuno-functionalized nanogels is tested in an endothelial cell line, ECV304, using confocal and epifluorescence microscopy. Intracellular localization studies reveal a faster uptake of the immuno-nanogel conjugate with respect to the ‘bare’ nanogel. The specific internalization pathway of these immuno-nanogels is clarified by selective endocytosis inhibition experiments, flow cytometry and confocal microscopy. Active targeting ability is also verified by conjugating a monoclonal antibody which recognizes the αv…
In vitroassessment of the biological response of Ti6Al4V implants coated with hydroxyapatite microdomains
2016
Dental implantology is still an expanding field of scientific study because of the number of people that receive dental therapies throughout their lives worldwide. Recovery times associated to dental surgery are still long and demand strategies to improve integration of metallic devices with hard tissues. In this work, an in vitro ceramic coating is proposed to improve and accelerate osseointegration of titanium surfaces conceived to be used as dental implants or hip or knee prosthesis, shaped either as dishes or screws. Such coating consists of hydroxyapatite microdomains on the implant surfaces obtained in vitro by immersion of titanium alloy samples (Ti6Al4V) in a simulated body fluid. T…
Transient hypothyroidism during lactation alters the development of the corpus callosum in rats. An in vivo magnetic resonance image and electron mic…
2020
Magnetic resonance imaging (MRI) data of children with late diagnosed congenital hypothyroidism and cognitive alterations such as abnormal verbal memory processing suggest altered telencephalic commissural connections. The corpus callosum (CC) is the major inter-hemispheric commissure that contra-laterally connects neocortical areas. However, in late diagnosed neonates with congenital hypothyroidism, the possible effect of early transient and chronic postnatal hypothyroidism still remains unknown. We have studied the development of the anterior, middle and posterior CC, using in vivo MRI and electron microscopy in hypothyroid and control male rats. Four groups of methimazole (MMI) treated r…
Imaging Noncanonical Autophagy and LC3-Associated Phagocytosis in Cultured Cells
2019
International audience; Monitoring of ATG8 proteins by western blotting and immunofluorescence microscopy are the most common methods to monitor the autophagy pathway. However, it has recently been shown that ATG8 proteins can be lipidated to non-autophagosome, single-membrane compartments through a noncanonical autophagy pathway. This is commonly found to occur during macro-endocytic processes such as phagocytosis, where it has been termed LC3-associated phagocytosis, and upon lysosomotropic drug treatment. Therefore, care is required when interpreting data based on ATG8 in order to conclude whether a signal relates to the canonical or noncanonical pathway. Here we provide methods to monit…
Quantification of propagating and standing surface acoustic waves by stroboscopic X-ray photoemission electron microscopy.
2018
The quantification of surface acoustic waves (SAWs) in LiNbO3 piezoelectric crystals by stroboscopic X-ray photoemission electron microscopy (XPEEM), with a temporal smearing below 80 ps and a spatial resolution below 100 nm, is reported. The contrast mechanism is the varying piezoelectric surface potential associated with the SAW phase. Thus, kinetic energy spectra of photoemitted secondary electrons measure directly the SAW electrical amplitude and allow for the quantification of the associated strain. The stroboscopic imaging combined with a deliberate detuning allows resolving and quantifying the respective standing and propagating components of SAWs from a superposition of waves. Furth…