scholarly journals New Insights Into Sperm Ultrastructure Through Enhanced Scanning Electron Microscopy

2021 ◽  
Vol 9 ◽  
Author(s):  
Denis Korneev ◽  
D. Jo Merriner ◽  
Gediminas Gervinskas ◽  
Alex de Marco ◽  
Moira K. O’Bryan
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Three Dimensional ◽  
Surface Topology ◽  
Sperm Ultrastructure ◽  
Fibrous Sheath ◽  
Coated Surfaces ◽  
Scanning Electron

The analysis of spermatozoa morphology is fundamental to understand male fertility and the etiology of infertility. Traditionally scanning electron microscopy (SEM) has been used to define surface topology. Recently, however, it has become a critical tool for three-dimensional analysis of internal cellular ultrastructure. Modern SEM provides nanometer-scale resolution, but the meaningfulness of such information is proportional to the quality of the sample preservation. In this study, we demonstrate that sperm quickly and robustly adhere to gold-coated surfaces. Leveraging this property, we developed three step-by-step protocols fulfilling different needs for sperm imaging: chemically fixed monolayers for SEM examination of the external morphology, and two high-pressure freezing-based protocols for fast SEM examination of full cell internal morphology and focused ion-beam SEM tomography. These analyses allow previously unappreciated insights into mouse sperm ultrastructure, including the identification of novel structures within the fibrous sheath and domain-specific interactions between the plasma membrane and exosome-like structures.

scholarly journals New insights into sperm ultrastructure through enhanced scanning electron microscopy

2020 ◽  
Author(s):  
Denis Korneev ◽  
D. Jo Merriner ◽  
Gediminas Gervinskas ◽  
Alex de Marco ◽  
Moira K O’Bryan
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Surface Topology ◽  
Sperm Ultrastructure ◽  
Fibrous Sheath ◽  
Domain Specific ◽  
Coated Surfaces ◽  
Scanning Electron

AbstractThe analysis of spermatozoa morphology is fundamental to understand male fertility and the aetiology of infertility. Traditionally scanning electron microscopy (SEM) has been used to define surface topology. Recently, however, it has become a critical tool for three-dimensionally analyse of internal cellular ultrastructure. Modern SEM provides nanometer-scale resolution, but the meaningfulness of such information is proportional to the quality of the sample preservation. In this study, we demonstrate that sperm quickly and robustly adhere to gold-coated surfaces. Leveraging this property, we developed three step-by-step protocols fulfilling different needs for sperm imaging: chemically fixed monolayers for SEM examination of the external morphology, and two high-pressure freezing-based protocols for fast SEM examination of full cell internal morphology and focused ion-beam SEM (FIB-SEM) tomography. These analyses allow previously unappreciated insights into mouse sperm ultrastructure, including the identification of novel structures within the fibrous sheath and domain-specific interactions between the plasma membrane and exosome-like structures.

Coupled Mechanical and Electrochemical Analyses of Three-Dimensional Reconstructed LiFePO4 by Focused Ion Beam/Scanning Electron Microscopy in Lithium-Ion Batteries

2018 ◽  
Vol 16 (1) ◽  
Author(s):  
Sangwook Kim ◽  
Hongjiang Chen ◽  
Hsiao-Ying Shadow Huang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Lithium Ion Batteries ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Three Dimensional ◽  
Lithium Ion ◽  
Electrochemical Degradation ◽  
Total Polarization ◽  
Scanning Electron

Limited lifetime and performance degradation in lithium ion batteries in electrical vehicles and power tools is still a challenging obstacle which results from various interrelated processes, especially under specific conditions such as higher discharging rates (C-rates) and longer cycles. To elucidate these problems, it is very important to analyze electrochemical degradation from a mechanical stress point of view. Specifically, the goal of this study is to investigate diffusion-induced stresses and electrochemical degradation in three-dimensional (3D) reconstructed LiFePO4. We generate a reconstructed microstructure by using a stack of focused ion beam-scanning electron microscopy (FIB/SEM) images combined with an electrolyte domain. Our previous two-dimensional (2D) finite element model is further improved to a 3D multiphysics one, which incorporates both electrochemical and mechanical analyses. From our electrochemistry model, we observe 95.6% and 88.3% capacity fade at 1.2 C and 2 C, respectively. To investigate this electrochemical degradation, we present concentration distributions and von Mises stress distributions across the cathode with respect to the depth of discharge (DoD). Moreover, electrochemical degradation factors such as total polarization and over-potential are also investigated under different C-rates. Further, higher total polarization is observed at the end of discharging, as well as at the early stage of discharging. It is also confirmed that lithium intercalation at the electrode-electrolyte interface causes higher over-potential at specific DoDs. At the region near the separator, a higher concentration gradient and over-potential are observed. We note that higher over-potential occurs on the surface of electrode, and the resulting concentration gradient and mechanical stresses are observed in the same regions. Furthermore, mechanical stress variations under different C-rates are quantified during the discharging process. With these coupled mechanical and electrochemical analyses, the results of this study may be helpful for detecting particle crack initiation.

Structuring of Conducting Polymers by Ion Implantation

1995 ◽  
Vol 396 ◽  
Author(s):  
Klaus Edinger ◽  
Stefanie Schiestel ◽  
Gerhard K. Wolf
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Ion Implantation ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Electrochemical Behaviour ◽  
Three Dimensional ◽  
Electrochemical Treatment ◽  
Lateral Structures ◽  
Scanning Electron

AbstractConducting polypyrrole polymer films have been modified by ion implantation. The resulting cross linking leads to changes in resistivity and electrochemical behaviour. By ion implantation through masks or with a focused ion beam lateral structures can be produced which can be imaged by scanning electron microscopy and optical absorption. The implanted polypyrrole layers can be removed by electrochemical treatment while not implanted regions can be electroplated. Therefore in combination with electrochemical treatment three dimensional structures have been generated and were investigated by atomic force microscopy. In order to study structures in the submicrometer range implantation experiments with a focused ion beam were performed and the minimal line widths were investigated by scanning electron microscopy.

Imaging three-dimensional tissue architectures by focused ion beam scanning electron microscopy

2011 ◽  
Vol 6 (6) ◽  
pp. 845-858 ◽  
Author(s):  
Andrew J Bushby ◽  
Kenneth M Y P'ng ◽  
Robert D Young ◽  
Christian Pinali ◽  
Carlo Knupp ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Three Dimensional ◽  
Beam Scanning ◽  
Scanning Electron
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