scholarly journals Scanning Electron Microscopy: Extrapolation of 3D Data from SEM Micrographs

2015 ◽  
Vol 21 (4) ◽  
Author(s):  
Simonas KAREIVA ◽  
Algirdas SELSKIS ◽  
Feliksas IVANAUSKAS ◽  
Simas ŠAKIRZANOVAS ◽  
Aivaras KAREIVA
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Sem Micrographs ◽  
3D Data ◽  
Scanning Electron

scholarly journals Phenotypic plasticity of wall ultrastructure in the green alga Pediastrum s.l. (Chlorophyta, Sphaeropleales)

2016 ◽  
Vol 61 (1) ◽  
pp. 73-88 ◽  
Author(s):  
Joanna Lenarczyk ◽  
Konrad Wołowski
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Phenotypic Plasticity ◽  
Green Alga ◽  
Phylogenetic Relationships ◽  
Diagnostic Character ◽  
Sem Micrographs ◽  
Wall Ultrastructure ◽  
Scanning Electron

Abstract This study examined wall ultrastructure variability in the microscopic green alga Pediastrum s.l. Its value as a diagnostic character is discussed. Field and cultured material of 21 taxa were compared using light and scanning electron microscopy. Nine ultrastructural elements occurring on the surface of Pediastrum are documented with LM and SEM micrographs. The highest number of taxa showed reticulate ornamentation composed of a trigonal mesh and granules situated on its corners. The paper considers the use of wall ultrastructure to reconcile traditional and modern taxonomical systems with regard to Pediastrum varieties, and addresses the phylogenetic relationships between strains representing different varieties.

scholarly journals TAYLOR CONE–JET MODE IN THE FABRICATION OF ELECTROSPRAYED MICROSPHERES

2018 ◽  
Vol 55 (1B) ◽  
pp. 216 ◽  
Author(s):  
Viet Linh Nguyen - Vu
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Polymer Solution ◽  
Flow Rate ◽  
Applied Voltage ◽  
Processing Parameters ◽  
Taylor Cone ◽  
Sem Micrographs ◽  
Scanning Electron

In this study, electrospray modes were investigated to clarify their effects on the morphology and size of polycaprolactone (PCL) particles. The result indicated that electrosprayed microspheres with homogeneous and stable morphology were fabricated by using cone–jet mode and suitable electrospray processing parameters. Besides, the PCL solution was created by dissolving in dichloromethane with different concentrations such as 3.5%, 4%, 4.5% and 5%. The scanning electron microscopy (SEM) micrographs pointed that electrosprayed PCL microspheres were formed by using 4.5 % polymer solution. In addition, the reproducible and homogeneous morphology of PCL microparticles were obtained at the following set of parameters: applied voltage of 18 kV, flow rate of 1.5 mL/h and distance tip to collector of 20 cm. Moreover, at the collecting distance of 15–25 cm, the flow rate of 1.2–1.8 mL/h and applied voltage of 18 kV the cone–jet mode was generated. It was an effective electrospray mode to create stable and homogeneous microspheres.

Licea aurea a new Myxomycete from the Peruvian Andes

Phytotaxa ◽  
2019 ◽  
Vol 391 (3) ◽  
pp. 218 ◽  
Author(s):  
DIANA WRIGLEY DE BASANTA ◽  
ARTURO ESTRADA-TORRES ◽  
CARLOS LADO
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Life Cycle ◽  
Moist Chamber ◽  
Peruvian Andes ◽  
Sem Micrographs ◽  
Scanning Electron

A new sessile species of myxomycete, Licea aurea is described, based on material from the Andean puna in Peru at almost 5000 m. It was isolated from moist chamber cultures of Azorella compacta litter and cultured on agar from spore to spore. It can be distinguished from other species in the genus by its small size, golden colour, dehiscence and smooth thick-walled spores with a thinner area. Life-cycle events are described and illustrated, from germination to sporulation. The morphology of the myxomycete specimens was examined using light and scanning electron microscopy, and both light and SEM micrographs of relevant details are included.

scholarly journals Controlling the morphology of polycaprolactone microparticles produced by electrospraying

2017 ◽  
Vol 1 (T4) ◽  
pp. 130-137
Author(s):  
Linh Vu Viet Nguyen ◽  
Phu Dai Huynh
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Polymer Concentration ◽  
Solvent Mixtures ◽  
Protein Carrier ◽  
Sem Micrographs ◽  
Spherical Morphology ◽  
Low Concentration ◽  
Chain Entanglements ◽  
Scanning Electron

Electrospraying is an effective method to produce polycaprolactone microparticles for drug or protein carrier application. In this study, some factors which influenced the morphology of polycaprolactone (PCL) particles were investigated by Scanning Electron Microscopy (SEM), such as polymer concentration, solvent and distance from tip to the collector. The SEM micrographs indicated that the low concentration (1 %) of PCL solution created in wrinkled and hollow semi-spheres while wrinkled spheres were formed by using higher polymer concentration (4 %). The spherical morphology was obtained when the polymer concentration was high enough (4 %) to create significant chain entanglements. In addition, chloroform and dichloromethane were good solvents to fabricate electrosprayed microspheres. Solvent mixtures such as acetone and chloroform or Dimethylformamide (DMF) and chloroform were unsuitable for electrosprayed particles since they caused unstable and heterogeneous shape. This research demonstrated that the morphology of microparticles was controlled by adjusting parameters of electrospraying to have a homogeneous and stable morphology.

Effect of SiO2 Particle Concentration on the Tribological Properties of PTFE Sealing Material

2012 ◽  
Vol 500 ◽  
pp. 617-622
Author(s):  
Yan Liang Zhang ◽  
Jun Zhou ◽  
Jian Xin Deng
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Tribological Properties ◽  
Particle Concentration ◽  
Sem Micrographs ◽  
Sealing Material ◽  
Scanning Electron

Oil suspension was made with different concentrations of SiO2 particles.The effects of SiO2 with different concentrations on frictional pairs 45# -PTFE under different velocities is investigated on MRH-3 abrasion tester. The worn of PTFE surfaces was investigated by scanning electron microscopy (SEM).The results show that the friction coefficient increases with increasing SiO2 concentrations. The wear rate increases with the increasing particle concentration and then decreases a bit. Meanwhile the degree of wear increases with increasing particle concentrations. Furthermore, as shown in SEM micrographs, the main machenism of PTFE is furrowing wear.

Pathogenesis of Human Hair Defects

1974 ◽  
Vol 32 ◽  
pp. 12-13
Author(s):  
P.S. Porter ◽  
T. Aoyagi ◽  
R. Matta
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Human Hair ◽  
Standard Techniques ◽  
Scanning Electron

Using standard techniques of scanning electron microscopy (SEM), over 1000 human hair defects have been studied. In several of the defects, the pathogenesis of the abnormality has been clarified using these techniques. It is the purpose of this paper to present several distinct morphologic abnormalities of hair and to discuss their pathogenesis as elucidated through techniques of scanning electron microscopy.

Ultrastructural Analysis of the Salivary Glands of Gromphadorhina Portentosa (Schaum)

1977 ◽  
Vol 35 ◽  
pp. 638-639
Author(s):  
P.J. Dailey
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Salivary Glands ◽  
Secretory Vesicles ◽  
The Past ◽  
Transmission Electron ◽  
Means Of Transmission ◽  
Gromphadorhina Portentosa ◽  
Scanning Electron ◽  
Topographical Relief

The structure of insect salivary glands has been extensively investigated during the past decade; however, none have attempted scanning electron microscopy (SEM) in ultrastructural examinations of these secretory organs. This study correlates fine structure by means of SEM cryofractography with that of thin-sectioned epoxy embedded material observed by means of transmission electron microscopy (TEM).Salivary glands of Gromphadorhina portentosa were excised and immediately submerged in cold (4°C) paraformaldehyde-glutaraldehyde fixative1 for 2 hr, washed and post-fixed in 1 per cent 0s04 in phosphosphate buffer (4°C for 2 hr). After ethanolic dehydration half of the samples were embedded in Epon 812 for TEM and half cryofractured and subsequently critical point dried for SEM. Dried specimens were mounted on aluminum stubs and coated with approximately 150 Å of gold in a cold sputtering apparatus.Figure 1 shows a cryofractured plane through a salivary acinus revealing topographical relief of secretory vesicles.

Two- or three-way observations of the identical cell elements within the same sections by LM, TEM and/or SEM

1978 ◽  
Vol 36 (2) ◽  
pp. 82-83 ◽  
Author(s):  
Nakazo Watari ◽  
Yasuaki Hotta ◽  
Yoshio Mabuchi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Light Microscopy ◽  
Thin Sections ◽  
Transmission Electron ◽  
Identical Cell ◽  
Electron Microscopes ◽  
Scanning Electron

It is very useful if we can observe the identical cell elements within the same sections by light microscopy (LM), transmission electron microscopy (TEM) and/or scanning electron microscopy (SEM) sequentially, because, the cell fine structure can not be indicated by LM, while the color is; on the other hand, the cell fine structure can be very easily observed by EM, although its color properties may not. However, there is one problem in that LM requires thick sections of over 1 μm, while EM needs very thin sections of under 100 nm. Recently, we have developed a new method to observe the same cell elements within the same plastic sections using both light and transmission (conventional or high-voltage) electron microscopes.In this paper, we have developed two new observation methods for the identical cell elements within the same sections, both plastic-embedded and paraffin-embedded, using light microscopy, transmission electron microscopy and/or scanning electron microscopy (Fig. 1).

Spontaneous Cataract in Nude Athymic Mice

1977 ◽  
Vol 35 ◽  
pp. 512-513
Author(s):  
Ronald H. Bradley ◽  
R. S. Berk ◽  
L. D. Hazlett
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Nude Mouse ◽  
Cellular Immunity ◽  
Phosphate Buffer ◽  
Osmium Tetroxide ◽  
Athymic Mice ◽  
Transmission Microscopy ◽  
Mouse Lens ◽  
Scanning Electron

The nude mouse is a hairless mutant (homozygous for the mutation nude, nu/nu), which is born lacking a thymus and possesses a severe defect in cellular immunity. Spontaneous unilateral cataractous lesions were noted (during ocular examination using a stereomicroscope at 40X) in 14 of a series of 60 animals (20%). This transmission and scanning microscopic study characterizes the morphology of this cataract and contrasts these data with normal nude mouse lens.All animals were sacrificed by an ether overdose. Eyes were enucleated and immersed in a mixed fixative (1% osmium tetroxide and 6% glutaraldehyde in Sorenson's phosphate buffer pH 7.4 at 0-4°C) for 3 hours, dehydrated in graded ethanols and embedded in Epon-Araldite for transmission microscopy. Specimens for scanning electron microscopy were fixed similarly, dehydrated in graded ethanols, then to graded changes of Freon 113 and ethanol to 100% Freon 113 and critically point dried in a Bomar critical point dryer using Freon 13 as the transition fluid.

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