scholarly journals Insight into <i>Emiliania huxleyi</i> coccospheres by focused ion beam sectioning

2015 ◽  
Vol 12 (3) ◽  
pp. 825-834 ◽  
Author(s):  
R. Hoffmann ◽  
C. Kirchlechner ◽  
G. Langer ◽  
A. S. Wochnik ◽  
E. Griesshaber ◽  
...  
Keyword(s):  
Electron Micrographs ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Emiliania Huxleyi ◽  
Exponential Growth Phase ◽  
Cell Diameter ◽  
Scanning Electron Micrographs ◽  
Ongoing Debate ◽  
Insight Into ◽  
Sinking Velocity

Abstract. Coccospheres of a cultured Emiliania huxleyi clone were sampled in the exponential growth phase and sectioned using a focused ion beam microscope. An average of 69 sections and the corresponding secondary electron micrographs per coccosphere provided detailed information on coccosphere architecture. The coccospheres feature 2–3 layers on average and 20 coccoliths per cell, of which only 15 can be seen in conventional scanning electron micrographs. The outer coccosphere diameter was positively correlated with the number of coccolith layers. By contrast, the inner coccosphere diameter (around 4.36 μm), and hence the cell diameter, was quasi-constant. Coccoliths were not evenly distributed across the coccosphere, resulting more often than not in one part of the coccosphere displaying more coccolith layers than the other. The architectural data allowed for the calculation of the PIC $/$ POC ratio, the density and the sinking velocity of individual cells. The correlation of these parameters has implications for the ongoing debate on the function of coccoliths.

scholarly journals Insight into <i>Emiliania huxleyi</i> coccospheres by focused ion beam sectioning

2014 ◽  
Vol 11 (9) ◽  
pp. 12773-12797 ◽  
Author(s):  
R. Hoffmann ◽  
C. Kirchlechner ◽  
G. Langer ◽  
A. S. Wochnik ◽  
E. Griesshaber ◽  
...  
Keyword(s):  
Electron Micrographs ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Emiliania Huxleyi ◽  
Sufficient Accuracy ◽  
Exponential Growth Phase ◽  
Cell Diameter ◽  
Scanning Electron Micrographs ◽  
Ongoing Debate ◽  
Insight Into

Abstract. Coccospheres of a cultured Emiliania huxleyi clone were sampled in the exponential growth phase and sectioned using a focused ion beam microscope. An average of 69 sections and the corresponding secondary electron micrographs per coccosphere provided detailed information on coccosphere architecture. The latter features, 2–3 layers on average and 20 coccoliths per cell, of which only 15 can be seen in conventional scanning electron micrographs. The outer coccosphere diameter was positively correlated with the number of coccolith layers. By contrast, the inner coccosphere diameter (around 4.36 μm), and hence the cell diameter, was quasi-constant. Coccoliths were not evenly distributed across the coccosphere, resulting more often than not, in one part of the coccosphere displaying more coccolith layers than the other. The architectural data allowed us to calculate, with sufficient accuracy, the PIC/POC ratio and the density of individual cells. The lack of a significant correlation of the latter parameters has implications for the ongoing debate on the function of coccoliths.

Three-dimensional structure analysis of melanocytes and keratinocytes in senile lentigo

Microscopy ◽  
2020 ◽  
Author(s):  
Yuki Mizutani ◽  
Mika Yamashita ◽  
Rie Hashimoto ◽  
Toru Atsugi ◽  
Akemi Ryu ◽  
...  
Keyword(s):  
Electron Micrographs ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Normal Skin ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Confocal Laser ◽  
Scanning Electron Micrographs ◽  
Large Numbers ◽  
Dimensional Reconstruction

Abstract Senile lentigo or age spots are hyperpigmented macules of skin that commonly develop following long-term exposure to ultraviolet radiation. This condition is caused by accumulation of large numbers of melanosomes (melanin granules) produced by melanocytes within neighboring keratinocytes. However, there is still no consensus regarding the melanosome transfer mechanism in senile lentigo. To date, most pathohistological studies of skin have been two-dimensional and do not provide detailed data on the complex interactions of the melanocyte–keratinocyte network involved in melanosome transfer. We performed a three-dimensional reconstruction of the epidermal microstructure in senile lentigo using three different microscopic modalities to visualize the topological melanocyte–keratinocyte relationship and melanosome distribution. Confocal laser microscopy images showed that melanocyte dendritic processes are more frequently branched and elongated in senile lentigo skin than in normal skin. Serial transmission electron micrographs showed that dendritic processes extend into intercellular spaces between keratinocytes. Focused ion beam-scanning electron micrographs showed that dendritic processes in senile lentigo encircle adjacent keratinocytes and accumulate large numbers of melanosomes. Moreover, melanosomes transferred to keratinocytes are present not only in the supranuclear area but throughout the perinuclear area except on the basal side. The use of these different microscopic methods helped to elucidate the three-dimensional morphology and topology of melanocytes and keratinocytes in senile lentigo. We show that the localization of melanosomes in dendritic processes to the region encircling recipient keratinocytes contributes to efficient melanosome transfer in senile lentigo.

scholarly journals Insight into the Characteristics of Novel Desmin-Immunopositive Perivascular Cells of the Anterior Pituitary Gland Using Transmission and Focused Ion Beam Scanning Electron Microscopy

2021 ◽  
Vol 22 (16) ◽  
pp. 8630
Author(s):  
Depicha Jindatip ◽  
Rebecca Wan-Yan Poh ◽  
Ken Fujiwara
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Pituitary Gland ◽  
Anterior Pituitary ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Cell Type ◽  
Insight Into ◽  
Scanning Electron

Recently, another new cell type was found in the perivascular space called a novel desmin-immunopositive perivascular (DIP) cell. However, the differences between this novel cell type and other nonhormone-producing cells have not been clarified. Therefore, we introduced several microscopic techniques to gain insight into the morphological characteristics of this novel DIP cell. We succeeded in identifying novel DIP cells under light microscopy using desmin immunocryosection, combining resin embedding blocks and immunoelectron microscopy. In conventional transmission electron microscopy, folliculostellate cells, capsular fibroblasts, macrophages, and pericytes presented a flat cisternae of rough endoplasmic reticulum, whereas those of novel DIP cells had a dilated pattern. The number of novel DIP cells was greatest in the intact rats, though nearly disappeared under prolactinoma conditions. Additionally, focused ion beam scanning electron microscopy showed that these novel DIP cells had multidirectional processes and some processes reached the capillary, but these processes did not tightly wrap the vessel, as is the case with pericytes. Interestingly, we found that the rough endoplasmic reticulum was globular and dispersed throughout the cytoplasmic processes after three-dimensional reconstruction. This study clearly confirms that novel DIP cells are a new cell type in the rat anterior pituitary gland, with unique characteristics.

Advanced Physical Analysis Methodology for Yield and Reliability of 28-nm, Bulk-Si, Flip-Chip ICs Using SEM and Backside Deprocessing

2012 ◽  
Author(s):  
Yuanjing (Jane) Li ◽  
Steven Scott ◽  
Howard Lee Marks
Keyword(s):  
Flip Chip ◽  
Focused Ion Beam ◽  
Process Development ◽  
Ion Beam ◽  
Physical Analysis ◽  
Electron Microscopic ◽  
Analysis Methodology ◽  
Processing Techniques ◽  
20 Nm ◽  
Insight Into

Abstract This paper presents a backside chip-level physical analysis methodology using backside de-processing techniques in combination with optimized Scanning Electron Microscopic (SEM) imaging technique and Focused Ion Beam (FIB) cross sectioning to locate and analyze defects and faults in failing IC devices. The case studies illustrate the applications of the method for 28nm flip chip bulk Si CMOS devices and demonstrate how it is used in providing insight into the fab process and design for process and yield improvements. The methods are expected to play an even more important role during 20-nm process development and yield-ramping.

New Insight into the Solid Electrolyte Interphase with Use of a Focused Ion Beam

2005 ◽  
Vol 109 (47) ◽  
pp. 22205-22211 ◽  
Author(s):  
Hong-Li Zhang ◽  
Feng Li ◽  
Chang Liu ◽  
Jun Tan ◽  
Hui-Ming Cheng
Keyword(s):  
Solid Electrolyte ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Solid Electrolyte Interphase ◽  
Insight Into

Localized Charging Effects Resulting From Focused Ion Beam Processing Of Non-Conductive Materials

2003 ◽  
Vol 792 ◽  
Author(s):  
Marion. A. Stevens-Kalceff ◽  
S. Rubanov ◽  
P. R. Munroe
Keyword(s):  
Surface Potential ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Surface Potentials ◽  
Conductive Materials ◽  
Scanning Surface Potential Microscopy ◽  
Charged Ions ◽  
Insight Into ◽  
Positively Charged ◽  
Ion Implanted

ABSTRACTFocused Ion Beam (FIB) systems employ a finely focussed beam of positively charged ions to process materials. Ion induced charging effects in non-conductive materials have been confirmed using Scanning Surface Potential Microscopy (SSPM). Significant localized residual charging is observed within the ion implanted micro-volumes of non-conductive materials both prior to and following the onset of sputtering. Characteristic observed surface potentials associated with the resultant charging have been modelled, giving insight into the charging processes during implantation and sputtering. The results of this work have implications for the processing and microanalysis of non-conductive materials in FIB systems.

Systematic Characterization of DRIE-Based Fabrication Process of Silicon Microneedles

2007 ◽  
Vol 1052 ◽  
Author(s):  
Jochen Held ◽  
Joao Gaspar ◽  
Patrick Ruther ◽  
Matthias Hagner ◽  
Andreas Cismak ◽  
...  
Keyword(s):  
Cross Sections ◽  
Focused Ion Beam ◽  
Process Analysis ◽  
Ion Beam ◽  
Scanning Electron Micrographs ◽  
Systematic Analysis ◽  
Deep Reactive Ion Etching ◽  
Etching Parameters ◽  
Anisotropic Etch

AbstractThis paper reports on the systematic characterization of a deep reactive ion etching based process for the fabrication of silicon microneedles. The possibility of using such microneedles as protruding microelectrodes enabling to electroporate adherently growing cells and to record intracellular potentials motivated the systematic analysis of the influence of etching parameters on the needle shape. The microneedles are fabricated using dry etching of silicon performed in three steps. A first isotropic step defines the tip of the needle. Next, an anisotropic etch increases the height of the needle. Finally, an isotropic etch step thins the microneedles and sharpens their tip. In total, 13 process parameters characterizing this etching sequence are varied systematically. Microneedles with diameters in the sub-micron range and heights below 10 µm are obtained. The resulting geometry of the fabricated microneedles is extracted from scanning electron micrographs of focused ion beam cross sections. The process analysis is based on design-of-experiment methods to find the dominant etch parameters. The dependence of the needle profiles on process settings are presented and interpolation procedures of the geometry with processing conditions are proposed and discussed.

Advanced electron microscopic techniques provide a deeper insight into the peculiar features of podocytes

2015 ◽  
Vol 309 (12) ◽  
pp. F1082-F1089 ◽  
Author(s):  
Tillmann Burghardt ◽  
Florian Hochapfel ◽  
Benjamin Salecker ◽  
Christine Meese ◽  
Hermann-Josef Gröne ◽  
...  
Keyword(s):  
Focused Ion Beam ◽  
Electron Tomography ◽  
Ion Beam ◽  
Electron Microscopic ◽  
Glomerular Filtration Barrier ◽  
Filtration Barrier ◽  
Future Work ◽  
Human And Mouse ◽  
Insight Into ◽  
Microscopic Techniques

Podocytes constitute the outer layer of the glomerular filtration barrier, where they form an intricate network of interdigitating foot processes which are connected by slit diaphragms. A hitherto unanswered puzzle concerns the question of whether slit diaphragms are established between foot processes of the same podocyte or between foot processes of different podocytes. By employing focused ion beam-scanning electron microscopy (FIB-SEM), we provide unequivocal evidence that slit diaphragms are formed between foot processes of different podocytes. We extended our investigations of the filtration slit by using dual-axis electron tomography of human and mouse podocytes as well as of Drosophila melanogaster nephrocytes. Using this technique, we not only find a single slit diaphragm which spans the filtration slit around the whole periphery of the foot processes but additional punctate filamentous contacts between adjacent foot processes. Future work will be necessary to determine the proteins constituting the two types of cell-cell contacts.

scholarly journals Evolution of SLA-Based Al2O3 Microstructure During Additive Manufacturing Process

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 3928
Author(s):  
Svyatoslav Chugunov ◽  
Nikolaus A. Adams ◽  
Iskander Akhatov
Keyword(s):  
Focused Ion Beam ◽  
Sintered Material ◽  
Ion Beam ◽  
Ct Scanning ◽  
3D Models ◽  
The Novel ◽  
Physical Processes ◽  
Ceramic Particles ◽  
Ceramic Samples ◽  
Insight Into

Evolution of additively manufactured (AM) ceramics’ microstructure between manufacturing stages is a hardly explored topic. These data are of high demand for advanced numerical modeling. In this work, 3D microstructural models of Al2O3 greenbody, brownbody and sintered material are presented and analyzed, for ceramic samples manufactured with SLA-based AM workflow, using a commercially available ceramic paste and 3D printer. The novel data, acquired at the micro- and mesoscale, using Computed Tomography (CT), Scanning Electron Microscopy (SEM) and Focused Ion-Beam SEM (FIB/SEM) techniques, allowed a deep insight into additive ceramics characteristics. We demonstrated the spatial 3D distribution of ceramic particles, an organic binder and pores at every stage of AM workflow. The porosity of greenbody samples (1.6%), brownbody samples (37.3%) and sintered material (4.9%) are analyzed. Pore distribution and possible originating mechanisms are discussed. The location and shape of pores and ceramic particles are indicative of specific physical processes driving the ceramics manufacturing. We will use the presented microstructural 3D models as input and verification data for advanced numerical simulations developed in the project.

Fundamental Criteria for the Propagation of Telephone Cord Buckles Beneath DLC Films on Glass Substrates

2001 ◽  
Vol 695 ◽  
Author(s):  
Myoung-Woon Moon ◽  
Kyang-Ryel Lee ◽  
Jin-Won Chung ◽  
And Kyu Hwan Oh
Keyword(s):  
Focused Ion Beam ◽  
Imaging System ◽  
Ion Beam ◽  
Repeat Unit ◽  
Carbon Films ◽  
Local Mode ◽  
Force Microscopy ◽  
Glass Substrates ◽  
Atomic Force ◽  
Insight Into

ABSTRACTThe topology of telephone cord buckles that form beneath compressed diamond-like carbon films (DLC) on glass substrates has been characterized with Atomic Force Microscopy (AFM) and with the Focused Ion Beam (FIB). Using AFM with 2nm resolution, the wavelength and amplitude of the buckles and their profiles have been measured. It has been found that, within each wavelength, the profile has symmetric and asymmetric segments. These changes have been related to differences in local mode mixity around the periphery of each repeat unit along the buckle, resulting in a fundamental rationale for the factors governing the wavelength. Sections made through various segments of the buckle by using the FIB imaging system result in local changes in the shape and size of the buckles that provide further insight into the buckle propagation criterion.

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