scholarly journals Centriolar defects, centrin 1 alterations, and FISH studies in human spermatozoa of a male partner of a couple that produces aneuploid embryos in natural and artificial fertilization

2021 ◽  
Author(s):  
Elena Moretti ◽  
Daria Noto ◽  
Raffaella Guazzo ◽  
Andrea Menchiari ◽  
Giuseppe Belmonte ◽  
...  
Keyword(s):  
Normal Forms ◽  
Semen Analysis ◽  
Male Partner ◽  
Fish Analysis ◽  
Tem Analysis ◽  
Paternal Contribution ◽  
Transmission Electron ◽  
Artificial Fertilization ◽  
Distal Centriole

Abstract Purpose To study the potential paternal contribution to aneuploidies in the man of a couple who obtained trisomic embryos with natural and assisted fertilization. Methods Semen analysis, immunofluorescence for localization of tubulin and centrin 1, transmission electron microscopy (TEM), and fluorescence in situ hybridization (FISH) analysis for chromosomes 18 and 9 were performed. Sperm of fertile men were used as controls. Results The percentages of sperm motility and normal forms were decreased. The percentages of sperm with tail reduced in dimension, headless tails, coiled tails, and altered head-tail junction were significantly higher (P < 0.01) in the patient than in controls, whereas the percentage of sperm with a normal centrin 1 localization (two spots in the centriolar area) was significantly reduced (P < 0.01) in the patient. Immunofluorescence with anti-tubulin antibody showed that in most of the patient’s sperm connecting pieces (83.00 ± 1.78%), two spots were present, indicating prominent proximal centriole/centriolar adjunct and evident distal centriole, whereas controls’ sperm displayed a single spot, indicating the proximal centriole. The percentage of sperm with two spots was significantly higher (P < 0.01) in the patient than in controls. TEM analysis showed that centriolar adjuncts of the patient’s sperm were significantly longer (721.80 ± 122.26 nm) than in controls’ sperm (310.00 ± 64.11 nm; P < 0.001). The aneuploidy frequencies of the patient’s sperm, detected by FISH analysis, were increased with respect to controls. Conclusion A paternal contribution to sperm aneuploidies cannot be excluded since the patient’s sperm showed altered morphology, immature centriolar adjunct, presence of evident distal centriole, scarce presence of centrin 1, and high aneuploidy frequency.

Growth of Epitaxial IrSi3 Layers on Si(111)

1989 ◽  
Vol 160 ◽  
Author(s):  
T. L. Lin ◽  
C. W. Nieh
Keyword(s):  
Surface Morphology ◽  
Molecular Beam ◽  
Solid Phase ◽  
Single Mode ◽  
Growth Conditions ◽  
Tem Analysis ◽  
Mbe Growth ◽  
Good Surface ◽  
Transmission Electron

AbstractEpitaxial IrSi3 films have been grown on Si (111) by molecular beam epitaxy (MBE) at temperatures ranging from 630 to 800 °C and by solid phase epitaxy (SPE) at 500 °C. Good surface morphology was observed for IrSi3 layers grown by MBE at temperatures below 680 °C, and an increasing tendency to form islands is noted in samples grown at higher temperatures. Transmission electron microscopy (TEM) analysis reveals that the IrSi3 layers grow epitaxially on Si(111) with three epitaxial modes depending on the growth conditions. For IrSi3 layers grown by MBE at 630 °C, two epitaxial modes were observed with ~ 50% area coverage for each mode. Single mode epitaxial growth was achieved at a higher MBE growth temperature, but with island formation in the IrSi3 layer. A template technique was used with MBE to improve the IrSi3 surface morphology at higher growth temperatures. Furthermore, single-crystal IrSi3 was grown on Si(111) at 500 °C by SPE, with annealing performed in-situ in a TEM chamber.

A Facile Synthesis of Poly(3-octylthiophene)-Titanium Dioxide Nanocomposite Particles in Supercritical CO2

2008 ◽  
Vol 8 (9) ◽  
pp. 4743-4746 ◽  
Author(s):  
Haldorai Yuvaraj ◽  
Min Hee Woo ◽  
Eun Ju Park ◽  
Yeong-Soon Gal ◽  
Kwon Taek Lim
Keyword(s):  
Titanium Dioxide ◽  
Oxidative Polymerization ◽  
X Ray Diffraction ◽  
Photoluminescence Quenching ◽  
Tem Analysis ◽  
Ir Studies ◽  
Transmission Electron ◽  
Ft Ir ◽  
Synthesized Materials

Poly(3-octylthiophene) (P3OT)-titanium dioxide (TiO2) nanocomposite powder where TiO2 was embedded with homogeneous dispersion was synthesized by in-situ chemical oxidative polymerization of 3-octylthiophene in the presence of TiO2 nanoparticles in supercritical carbon dioxide (scCO2), using ferric chloride as the oxidant. The synthesized materials could be obtained as dry powder upon venting of CO2 after the polymerization. The composites were subsequently characterized by FT-IR spectroscopy, transmission electron microscopy (TEM), X-ray diffraction studies (XRD), thermogravimetric analysis (TGA) and photoluminescence (PL). The incorporation of TiO2 in the composite was endorsed by FT-IR studies. TGA revealed enhanced thermal stability of P3OT/TiO2 nanocomposite compared to 3-octylthiophene. TEM analysis showed that well dispersed TiO2 nanoparticles in the polymer matrix. Photoluminescence quenching increased with increasing TiO2 concentration in the composite.

Time-Resolved Optical Studies of Amorphous CoSi Thin-Film Crystallization

1992 ◽  
Vol 280 ◽  
Author(s):  
M. Libera ◽  
T. Kim ◽  
K. Siangchaew ◽  
L. Clevenger ◽  
Q. Hong
Keyword(s):  
Kinetic Modelling ◽  
Optical Data ◽  
Optical Studies ◽  
Tem Analysis ◽  
Reflection And Transmission ◽  
Time Resolved ◽  
Transmission Electron ◽  
Transmission Measurements ◽  
Potential Use

ABSTRACTTime-resolved reflection and transmission measurements during heating are coupled with transmission electron microscopy (TEM) to study the crystallization of amorphous 75nm Co49Si51 films. The reflection decreases and the transmission increases upon crystallization. Optical data are converted to a measure of the fraction crystallized, χ=χ(T,t). A Kissinger analysis gives an activation energy for crystallization of 1.1 eV. TEM analysis of films crystallized in-situ show they are principally CoSi2 with a small amount of CoSi2. These results are being used for kinetic modelling of crystallization of amorphous Co-silicide films for potential use in Si mosfet and bipolar technologies.

Preparation of in Situ Cu-Nb Composite Sheet and Wire for Tem Analysis

1987 ◽  
Vol 115 ◽  
Author(s):  
C. L. Trybus ◽  
F. C. Laabs ◽  
A. R. Pelton ◽  
V. A. Spitzig
Keyword(s):  
Electrochemical Techniques ◽  
Wire Drawing ◽  
Thick Sheet ◽  
Two Phase ◽  
Tem Analysis ◽  
Excessive Heat ◽  
Transmission Electron ◽  
Transmission Electron Microscopy Characterization ◽  
Microscopy Characterization

ABSTRACTCu-Nb in situ composites attain anomolous increases in strength upon mechanical deformation. The unique filamentary microstructures that evolve during processing (cold rolling and/or wire drawing) are the source of the strengthening. Results from transmission electron microscopy characterization studies have played a key role in the understanding of the relationships between structure and properties. However, the fabrication of reliable TEM samples has been extremely challenging for the following reasons: (1) traditional electrochemical techniques are not suitable for the two-phase microstructure, (2) preparation of longitudinal and transverse sections of fine (∼150 μm diameter wires) and thin (∼60 μm thick) sheet is tedious, and (3) it is necessary to avoid excessive heat (< 30°C) during sample preparation to preserve the metastable structural arrangements. This paper will review the procedures used to prepare TEM specimens from bulk wire and sheet samples as well as from extracted Nb filaments. Proper techniques for plating, mounting, sectioning, polishing, and ion-thinning will be discussed.

Formation of Pb Inclusions in Si by Ion Implantation

1997 ◽  
Vol 504 ◽  
Author(s):  
V. S. Touboltsev ◽  
E. Johnson ◽  
U. Dahmen ◽  
A. Johansen ◽  
L. Sarholt ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Average Concentration ◽  
Supersaturated Solution ◽  
In Situ Tem ◽  
Tem Analysis ◽  
Host Matrix ◽  
Transmission Electron ◽  
Main Fraction ◽  
20 Nm

AbstracrSi<110> single crystals were implanted at a temperature of 835 K with 150 keV Pb+ ions to a fluence of 1·1020 m−2 corresponding to an average concentration of 2–3 at%. The implanted samples have been studied by Rutherford Backscattering (RBS)/channeling and transmission electron microscopy (TEM) techniques. In as-implanted samples the main fraction of implanted Pb was located on substitutional sites in the Si matrix thus providing a highly supersaturated solution of Pb in Si. Spontaneous precipitation of Pb, giving rise to formation of nanosized Pb inclusions, was found to take place only in the peak region of the implantation. TEM analysis showed that the Pb precipitates had sizes from about 2 to 20 nm and that they grew in parallel cube orientation relationship with the host matrix. The shape of the inclusions was found to be approximately cuboctahedral with poorly developed {111} and {100} facets.In-situ RBS/channeling heating/cooling experiments on both as-implanted samples and samples previously furnace-annealed at 1175 K showed a distinct melting/solidification hysteresis of the Pb inclusions around the bulk melting point for Pb at 600 K. These results were verified by in-situ TEM heating/cooling experiments on as-implanted samples.

Understanding the graphitization and growth of free-standing nanocrystalline graphene using in situ transmission electron microscopy

Nanoscale ◽  
2017 ◽  
Vol 9 (35) ◽  
pp. 12835-12842 ◽  
Author(s):  
C. N. Shyam Kumar ◽  
Venkata Sai Kiran Chakravadhanula ◽  
Adnan Riaz ◽  
Simone Dehm ◽  
Di Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Domain Growth ◽  
Free Standing ◽  
Tem Analysis ◽  
Thermally Induced ◽  
Transmission Electron

In situ TEM analysis of the thermally induced graphitization and domain growth of free-standing nanocrystalline graphene thin films.

The Progression from Optical Light Microscopy to Transmission Electron Microscopy in the Study of Soils

Clay Minerals ◽  
1994 ◽  
Vol 29 (2) ◽  
pp. 247-254 ◽  
Author(s):  
F. Van Oort ◽  
A. G. Jongmans ◽  
A. M. Jaunet
Keyword(s):  
Electron Microscopy ◽  
Clay Mineralogy ◽  
Tem Analysis ◽  
Undisturbed Soil ◽  
Thin Sections ◽  
Transmission Electron ◽  
Ultrathin Sections ◽  
Optical Light Microscopy ◽  
The Impact

AbstractThe use of electron microscopy to study clay microfabrics in thin-sections is discussed. A technique is described to isolate undisturbed microparts of pedofeatures from thin-sections, which are subsequently used for TEM analysis. Re-embedding with a polyester resin of undisturbed, in situ, neoformed clay microfabrics, obtained by microdrilling and preparation of ultrathin sections by microtoming with a diamond knife are emphasized; these steps enable micromorphology, clay mineralogy, microchemical and HRTEM analysis to be performed on one unique microsample of clay fabrics, with conserved micro-organization. Two examples on clay neoformation are presented to demonstrate that this technique can successfully be applied to unravel the impact of mineral alteration and clay neoformation in undisturbed soil samples on a micro- and a nanometer scale.

scholarly journals Analysis of complex, beam-sensitive materials by transmission electron microscopy and associated techniques

2020 ◽  
Vol 378 (2186) ◽  
pp. 20190601
Author(s):  
Martha Ilett ◽  
Mark S'ari ◽  
Helen Freeman ◽  
Zabeada Aslam ◽  
Natalia Koniuch ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Beam ◽  
Molecular Crystals ◽  
Optimum Dose ◽  
Tem Analysis ◽  
Transmission Electron ◽  
Imaging And Spectroscopy ◽  
And Function

We review the use of transmission electron microscopy (TEM) and associated techniques for the analysis of beam-sensitive materials and complex, multiphase systems in-situ or close to their native state. We focus on materials prone to damage by radiolysis and explain that this process cannot be eliminated or switched off, requiring TEM analysis to be done within a dose budget to achieve an optimum dose-limited resolution. We highlight the importance of determining the damage sensitivity of a particular system in terms of characteristic changes that occur on irradiation under both an electron fluence and flux by presenting results from a series of molecular crystals. We discuss the choice of electron beam accelerating voltage and detectors for optimizing resolution and outline the different strategies employed for low-dose microscopy in relation to the damage processes in operation. In particular, we discuss the use of scanning TEM (STEM) techniques for maximizing information content from high-resolution imaging and spectroscopy of minerals and molecular crystals. We suggest how this understanding can then be carried forward for in-situ analysis of samples interacting with liquids and gases, provided any electron beam-induced alteration of a specimen is controlled or used to drive a chosen reaction. Finally, we demonstrate that cryo-TEM of nanoparticle samples snap-frozen in vitreous ice can play a significant role in benchmarking dynamic processes at higher resolution. This article is part of a discussion meeting issue ‘Dynamic in situ microscopy relating structure and function’.

In Situ Tem Analysis of TiSi2 C49-C54 Transformations During Annealing

1996 ◽  
Vol 441 ◽  
Author(s):  
L. M. Gignac ◽  
V. Svilan ◽  
L. A. Clevenger ◽  
C. Cabral ◽  
C. Lavoie
Keyword(s):  
Nucleation Density ◽  
In Situ Tem ◽  
Video Tape ◽  
X Ray Diffraction ◽  
Tem Analysis ◽  
Transmission Electron ◽  
Varying Length ◽  
Transformation Front ◽  
Individual Line

AbstractIn situ transmission electron microscope (TEM) observations of TiSi2 C49-to-C54 phase transformations were recorded on video tape and photographic negatives, and transformation front velocities (vTF) were measured from the data. The samples studied in this work include: C49-TiSi2 blanket films and 0.2 μm wide, 7 mm long lines on undoped poly-Si and 0.13 μm wide, 10 μm long lines on either B- or As-doped poly-Si. The in situ TEM analysis showed that blanket TiSi2 films on undoped poly-Si fully transformed at 830°C and had an average vTF of 0.5 ± 0.2 μm/s. The transformation occurred from a sparse nucleation density of ˜0.1 site/μm2. The 0.2 μm wide lines transformed at temperatures greater than 885°C, and the average vTF was 1.1 ± 0.2 μm/sec. Agglomeration started for both the blanket film and the 0.2 μm wide lines at temperatures above 900°C. In situ x-ray diffraction (XRD) analyses of C49-TiSi2 on B- and As-doped poly-Si showed that blanket films completely transformed to C54-TiSi2 at T = 835–843°C, but 0.13 μm wide, varying length lines did not fully transform, even when rapid thermal annealed to 1025°C. From in situ TEM analysis of 0.13 μm wide, 10 μm long C49-TiSi2 lines on B-doped poly-Si, a distinct transformation was not observed. Instead, the lines slowly agglomerated, and electron diffraction of the agglomerated regions showed that the film had transformed to C54-TiSi2. An individual line either 1) completely transformed and agglomerated or 2) remained as C49-TiSi2 and did not agglomerate. Approximately 85% of all lines transformed. In situ TEM analysis of 0.13 μm wide, 10 μm long lines of C49-TiSi2 on As-doped poly-Si also showed an indistinct transformation to the C54 phase along with agglomeration, and 100% of the lines transformed.

Preparation of TiB2/TiN Nanocomposites by SP

2013 ◽  
Vol 745-746 ◽  
pp. 551-554 ◽  
Author(s):  
Ming Hui Wang ◽  
Hua Jian Li ◽  
Wan Jiang
Keyword(s):  
X Ray Diffraction ◽  
Tem Analysis ◽  
X Ray ◽  
Plasma Sintering ◽  
Transmission Electron ◽  
Average Grain Size ◽  
High Resolution Tem ◽  
Spark Plasma ◽  
Xrd Techniques

TiB2/TiN nanocomposites were in-situ fabricated by spark plasma sintering (SPS) technique using Ti and BN powders as starting materials. The phase constituents and microstructures of the samples were analyzed by X-ray diffraction (XRD) techniques, scanning electron microscopy (SEM) and transmission electron microscope (TEM), respectively. The results showed that the average grain size of TiB2 and TiN was 1m and 300nm respectively. Furthermore, high resolution TEM analysis indicated that the as-prepared TiB2/TiN nanocomposites had very clean grain boundaries, and no amorphous phase or oxide layer was observed.

Sign in / Sign up

Export Citation Format

Share Document