Scanning Electron Microscopy Sample Preparation and Imaging

Nguyen, Joanne; Harbison, Amanda M.

doi:10.1007/978-1-4939-6990-6_5

Cited by 40 publications

(23 citation statements)

References 8 publications

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“…Control sets were treated accordingly. The SEM and TEM samples were prepared by fixing and dehydration in graded ethanol upto 100% ethanol[40, 41]. Agar columns were also investigated using both SEM and TEM.…”

Section: Methodsmentioning

confidence: 99%

Sporosarcina pasteurii can form nanoscale calcium carbonate crystals on cell surface

et al. 2019

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The bacterium Sporosarcina pasteurii (SP) is known for its ability to cause the phenomenon of microbially induced calcium carbonate precipitation (MICP). We explored bacterial participation in the initial stages of the MICP process at the cellular length scale under two different growth environments (a) liquid culture (b) MICP in a soft agar (0.5%) column. In the liquid culture, ex-situ imaging of the cellular environment indicated that S. pasteurii was facilitating nucleation of nanoscale crystals of calcium carbonate on bacterial cell surface and its growth via ureolysis. During the same period, the meso-scale environment (bulk medium) was found to have overgrown calcium carbonate crystals. The effect of media components (urea, CaCl2), presence of live and dead in the growth medium were explored. The agar column method allows for in-situ visualization of the phenomena, and using this platform, we found conclusive evidence of the bacterial cell surface facilitating formation of nanoscale crystals in the microenvironment. Here also the bulk environment or the meso-scale environment was found to possess overgrown calcium carbonate crystals. Extensive elemental analysis using Energy dispersive X-ray spectroscopy (EDS) and X-ray powder diffraction (XRD), confirmed that the crystals to be calcium carbonate, and two different polymorphs (calcite and vaterite) were identified. Active participation of S. pasteurii cell surface as the site of calcium carbonate precipitation has been shown using EDS elemental mapping with Scanning transmission electron microscopy (STEM) and scanning electron microscopy (SEM).

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Section: Methodsmentioning

confidence: 99%

Sporosarcina pasteurii can form nanoscale calcium carbonate crystals on cell surface

et al. 2019

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“…), which interrogate small samples with specialized equipment not appropriate for direct clinical use. Care must be taken extending the results for clinical interpretation; for example, consider the sample preparation techniques required for electron microscopy (42). Still, we see MR microscopy as an essential tool to aid in understanding of clinical data, especially since the samples can be maintained as living tissue samples, allowing meaningful and informative perturbation studies to test models.…”

Section: Discussionmentioning

confidence: 99%

On the Origins of Diffusion MRI Signal Changes in Stroke

et al. 2020

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Magnetic resonance imaging (MRI) is a leading diagnostic technique especially for neurological studies. However, the physical origin of the hyperintense signal seen in MR images of stroke immediately after ischemic onset in the brain has been a matter of debate since it was first demonstrated in 1990. In this article, we hypothesize and provide evidence that changes in the glial cells, comprising roughly one-half of the brain's cells and therefore a significant share of its volume, accompanying ischemia, are the root cause of the MRI signal change. Indeed, a primary function of the glial cells is osmoregulation in order to maintain homeostasis in the neurons and nerve fibers for accurate and consistent function. This realization also impacts our understanding of signal changes in other tissues following ischemia. We anticipate that this paradigm shift will facilitate new and improved models of MRI signals in tissues, which will, in turn, impact clinical utility.

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“…The analysis was performed between 400 and 4000 cm −1 . The surface morphology was analyzed by SEM [11, 15, 16].…”

Section: Methodsmentioning

confidence: 99%

Synthesis of Atenolol-Imprinted Polymers with Methyl Methacrylate as Functional Monomer in Propanol Using Bulk and Precipitation Polymerization Method

Hasanah

Utari

Pratiwi

2019

Journal of Analytical Methods in Chemistry

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Atenolol is one of the beta-1 blocker drugs that is misused by athletes to increase their performance during competition. Therefore, it is important to analyze atenolol levels in blood selectively. The preparation method that can be used in separating atenolol in sample is molecular imprinting solid-phase extraction (MI-SPE) because it has good selectivity and sensitivity. This study aims to examine the characteristics and analytical performance of imprinted polymers synthesized from functional monomer methyl methacrylate. The stages of this study include the determination of association constants, synthesis of sorbent MI-SPE atenolol using the bulk polymerization method, and precipitation with atenolol as the template, methyl methacrylate as the functional monomer, and propanol as the porogen. The template was extracted from a polymer, and then, the adsorption ability, capacity, and selectivity of MI-SPE and finally the application of the best MI-SPE to spiked serum samples were determined. MI-SPE was also characterized by using Fourier-transform instrument infrared (FTIR) and scanning electron microscope (SEM). The result of characterization with FTIR and SEM showed that MIP made by the precipitation polymerization method was completely polymerized, more porous, and produced smaller particle size with an average value of 0.274 μm. It had better analytic performances than MIP made by bulk polymerization, with affinity value 0.3607 mg/g and homogeneity value 1.3246, and good selectivity toward atenolol with imprinting factor value 22.519. Application of MI-SPE to spiked serum samples has an excellent recovery percentage of 95.46% over 0% for the nonimprinting one. Based on the result of study, MIP made by precipitation polymerization could be used to extract atenolol on serum samples toward drug analysis.

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Scanning Electron Microscopy Sample Preparation and Imaging

Cited by 40 publications

References 8 publications

Sporosarcina pasteurii can form nanoscale calcium carbonate crystals on cell surface

Sporosarcina pasteurii can form nanoscale calcium carbonate crystals on cell surface

On the Origins of Diffusion MRI Signal Changes in Stroke

Synthesis of Atenolol-Imprinted Polymers with Methyl Methacrylate as Functional Monomer in Propanol Using Bulk and Precipitation Polymerization Method

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