Quantitative X-Ray Microanalysis

Goldstein, Joseph I.; Newbury, Dale E.; Echlin, Patrick; Joy, David C.; Fiori, Charles E.; Lifshin, Eric

doi:10.1007/978-1-4613-3273-2_7

Cited by 39 publications

(47 citation statements)

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“…The x-ray data were quantitated using the peak to background ratio (P/B) method (10). Standard element windows of 14 eV were used to integrate the area under the elemental peaks.…”

Section: Methodsmentioning

confidence: 99%

Intracellular Compartmentation of Ions in Salt Adapted Tobacco Cells

Binzel¹,

Hess²,

Bressan³

et al. 1988

Plant Physiol.

246

129

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Na+ and Cl-are the principal solutes utilized for osmotic adjustment in cells of Nicotiana tabacum L. var Wisconsin 38 (tobacco) adapted to NaCi, accumulating to levels of 472 and 386 millimolar, respectively, in cells adapted to 428 millimolar NaCI. X-ray microanalysis of unetched frozen-hydrated cells adapted to salt indicated that Na+ and Cl-were compartmentalized in the vacuole, at concentrations of 780 and 624 millimolar, respectively, while cytoplasmic concentrations of the ions were maintained at 96 millimolar. The morphometric differences which existed between unadapted and salt adapted cells, (cytoplasmic volume of 22 and 45% of the cell, respectively), facilitated containment of the excited volume of the x-ray signal in the cytoplasm of the adapted cells. Confirmation of ion compartmentation in salt adapted cells was obtained based on kinetic analyses of 22NaI and 36CI-efflux from cells in steady state. These data provide evidence that ion compartmentation is a component of salt adaptation of glycophyte ceUs.A typical response of many plants to saline environments, particularly halophytes, is to accumulate high intracellular concentrations of Na+ and Cl- (9,11,23,26,28). Since the in vitro activities of enzymes isolated from glycophytes or halophytes are inhibited equally by NaCl (9, 11), it has been generally accepted that the accumulated ions are sequestered in the vacuole and 'compatible solutes,' such as sugars, proline, and glycinebetaine, function to balance the osmotic pressure of the cytoplasm (9,11,26). This ability to compartmentalize Na+ and Cl-has been considered to be a mechanism of tolerance of halophytes (26).Although salt tolerance of glycophytes, particularly agronomic species, is usually attributed to the ability to exclude Na+ and Cl-, especially from the shoot (8, 11), intracellular ion compartmentation also may occur in these species. Despite indications of negative correlations between ion accumulation and salt tolerance in glycophytes, such as tomato (22), rice (29), wheat (27), and maize (12), examination of the data reveals that, even in tolerant genotypes, the accumulated levels of Na+ and Clare substantial. In some instances whole cell Na+ and Cl-accumulation was similar for both tolerant and sensitive genotypes (22,27,29). Thus, the ability to compartmentalize Na+ and Clmay be an underlying determinant of the tolerance not only of halophytes but also of many crop species.Verification of ion compartmentation has been restricted by the difficulty in obtaining reliable measurements of subcellular ion concentrations (7,15,23,30). Despite this, cytoplasmic Na + concentration in leaf cells of Suaeda maritima was determined to be 165 mm by efflux analysis when the whole cell concentration was about 600 mM (28). Data obtained by x-ray microanalysis of frozen hydrated leaves of Atriplex spongiosa (23) revealed that cytoplasmic ion concentrations were considerably lower than those in the vacuole.Results from investigations of glycophytes exposed to salinity have been less conc...

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“…The x-ray data were quantitated using the peak to background ratio (P/B) method (10). Standard element windows of 14 eV were used to integrate the area under the elemental peaks.…”

Section: Methodsmentioning

confidence: 99%

Intracellular Compartmentation of Ions in Salt Adapted Tobacco Cells

Binzel¹,

Hess²,

Bressan³

et al. 1988

Plant Physiol.

246

129

View full text Add to dashboard Cite

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“…3 Types of aberration caused in the lens [8] : (a) spherical aberration, (b) chromatic aberration, and (c) diffraction aberration 할 수 있어서 안정도가 높다는 장점을 가지고 있다 [4] . 또한 극간의 거리는 파센커브(paschen curve)를 참조하였고, 전극면을 줄여서 면적효과(area effect)를 줄임으로써, 진공 중 절연파괴를 줄일 수 있다는 보고 [5,6] 굴절하는 정도가 달라지게 되는 것이다 [7,8] . 이러한 영향들로 초점 [7,8] .…”

Section: 실험장비의 구성 및 실험방법unclassified

A Study on the Optimum Design of the Condenser Lens of a Compact Electrostatic-Type SEM

Kim¹,

Jang

Park³

2015

Journal of the Korean Society of Manufacturing Technology Engin

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Article history:In this paper, we describe the production of a specific electrostatic-type scanning electron microscope based on miniaturization for application in other types of vacuum equipment. The initial configuration of the SEM starts with a minimal configuration that allows people to view sample images. After improving the stability of the SEM operation and resolution, we conducted experiments on identifying the characteristics and development of an einzel-type condenser lens with reference to the demagnification lens system of an SEM. The experiments were conducted at an acceleration voltage of 5 kV and we found the shape of the lens to be more reliable than a conventional lens. The lens was then added to improve the resolution in the nanometer region. The current measured on the sample was approximately 40 pA and its magnification was 4,000 times. . 이는 시간과 비용의 절약을 극대화하고 전자현미경의 활용 가능성을 더욱 넓히는데 그 목적이 있다. 복합화에서 중요시되는 부분

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“…This approximation is acceptable in TEM, where accelerating voltages are typically within the range of 100-200 keV. However, it is no longer applicable at lower voltages, such as those used in a scanning electron microscope (SEM), where backscattering and high scattering angles become significant [8]. Furthermore, another drawback of diffraction simulation methods thus far is the inability to reproduce effects that result from the particle characteristics of electrons.…”

Section: Introductionmentioning

confidence: 99%

“…Furthermore, another drawback of diffraction simulation methods thus far is the inability to reproduce effects that result from the particle characteristics of electrons. These may include secondary and backscattering coefficients, electron transport and inelastic scattering [8]. Monte Carlo simulation methods are currently used in that effect.…”

Section: Introductionmentioning

confidence: 99%

A novel quantum dynamical approach in electron microscopy combining wave-packet propagation with Bohmian trajectories

Rudinsky

Sanz

Gauvin

2017

The Journal of Chemical Physics

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The numerical analysis of the diffraction features rendered by transmission electron microscopy (TEM) typically relies either on classical approximations (Monte Carlo simulations) or quantum paraxial tomography (the multislice method and any of its variants). Although numerically advantageous (relatively simple implementations and low computational costs), they involve important approximations and thus their range of applicability is limited. To overcome such limitations, an alternative, more general approach is proposed, based on an optimal combination of wave-packet propagation with the on-the-fly computation of associated Bohmian trajectories. For the sake of clarity, but without loss of generality, the approach is used to analyze the diffraction of an electron beam by a thin aluminum slab as a function of three different incidence (work) conditions which are of interest in electron microscopy: the probe width, the tilting angle, and the beam energy. Specifically, it is shown that, because there is a dependence on particular thresholds of the beam energy, this approach provides a clear description of the diffraction process at any energy, revealing at the same time any diversion of the beam inside the material towards directions that cannot be accounted for by other conventional methods, which is of much interest when dealing with relatively low energies and/or relatively large tilting angles.

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Quantitative X-Ray Microanalysis

Cited by 39 publications

References 0 publications

Intracellular Compartmentation of Ions in Salt Adapted Tobacco Cells

Intracellular Compartmentation of Ions in Salt Adapted Tobacco Cells

A Study on the Optimum Design of the Condenser Lens of a Compact Electrostatic-Type SEM

A novel quantum dynamical approach in electron microscopy combining wave-packet propagation with Bohmian trajectories

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