Scanning transmission X-ray microscopy study of subcellular granules in human platelets at the carbon K- and calcium L2,3-edges

ABSTRACTWhole mount (WM) platelet preparations followed by transmission electron microscopy (TEM) observation is the standard method currently used to assess dense granule (DG) deficiency (DGD). However, due to electron density-based contrast mechanism in TEM, other granules such as α-granules might cause false DGs detection. Herein, scanning transmission X-ray microscopy (STXM), was used to identify DGs and minimize false DGs detection of human platelets. STXM image stacks of human platelets were collected at the calcium (Ca) L2,3absorption edge and then converted to optical density maps. Ca distribution maps obtained by subtracting the optical density map at pre-edge region from those obtained at post-edge region were used for identification of DGs based on richness of Ca. Dense granules were successfully detected by using STXM method without false detection based on Ca maps for 4 human platelets. Spectral analysis of granules in human platelets confirmed that DGs contained richer Ca content than other granules. Image analysis of Ca maps provided quantitative parameters which would be useful for developing image-based DG diagnosis models. Therefore, we would like to propose STXM as a promising approach for better DG identification and DGD diagnosis, as a complementary tool to the current WM TEM approach.

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Scanning transmission X-ray microscopy study of microbial calcification

Geobiology ◽

10.1111/j.1472-4677.2004.00039.x ◽

2004 ◽

Vol 2 (4) ◽

pp. 249-259 ◽

Cited By ~ 123

Author(s):

K. BENZERARA ◽

T. H. YOON ◽

T. TYLISZCZAK ◽

B. CONSTANTZ ◽

A. M. SPORMANN ◽

...

Keyword(s):

Microscopy Study ◽

X Ray ◽

Scanning Transmission

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Scanning Transmission X-Ray Microscopy Study of TiSe2/NbSe2 Superlattices

MRS Proceedings ◽

10.1557/proc-441-603 ◽

1996 ◽

Vol 441 ◽

Author(s):

Hyun-Joon Shin ◽

Kwangho Jeong ◽

David C. Johnson ◽

Stephen D. Kevan ◽

Myungkeun Noh ◽

...

Keyword(s):

Light Source ◽

Microscopy Study ◽

Chemical Sensitivity ◽

X Ray ◽

Advanced Light Source ◽

Scanning Transmission ◽

Trapping Method ◽

Kinetic Trapping

AbstractTiSe2/NbSe2 superlattices crystallized from elementally modulated films have been studied with a Scanning Transmission X-ray Microscope (STXM) at the Advanced Light Source. The samples exhibited structures in the plane of the film with sizes of the order of one micrometer. The chemical sensitivity of STXM allowed us to infer that the titanium in the superlattice exists predominantly in microcrystalline TiSe2, but that these microcrystals are interspersed with elemental titanium inclusions. The STXM images reflect the interfacial nucleation between the constituent layers characteristic of the kinetic trapping method.

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Identification of Ca-rich dense granules in human platelets using scanning transmission X-ray microscopy

Journal of Synchrotron Radiation ◽

10.1107/s1600577520002702 ◽

2020 ◽

Vol 27 (3) ◽

pp. 720-724

Author(s):

Tung X. Trinh ◽

Sook Jin Kwon ◽

Zayakhuu Gerelkhuu ◽

Jang Sik Choi ◽

Jaewoo Song ◽

...

Keyword(s):

Optical Density ◽

Human Platelets ◽

Dense Granule ◽

Correct Identification ◽

Edge Region ◽

X Ray ◽

Distribution Maps ◽

Dense Granules ◽

Density Maps ◽

Scanning Transmission

Whole-mount (WM) platelet preparation followed by transmission electron microscopy (TEM) observation is the standard method currently used to assess dense granule (DG) deficiency (DGD). However, due to the electron-density-based contrast mechanism in TEM, other granules such as α-granules might cause false DG detection. Here, scanning transmission X-ray microscopy (STXM) was used to identify DGs and minimize false DG detection of human platelets. STXM image stacks of human platelets were collected at the calcium (Ca) L 2,3 absorption edge and then converted to optical density maps. Ca distribution maps, obtained by subtracting the optical density maps at the pre-edge region from those at the post-edge region, were used to identify DGs based on the Ca richness. DGs were successfully detected using this STXM method without false detection, based on Ca maps for four human platelets. Spectral analysis of granules in human platelets confirmed that DGs contain a richer Ca content than other granules. The Ca distribution maps facilitated more effective DG identification than TEM which might falsely detect DGs. Correct identification of DGs would be important to assess the status of platelets and DG-related diseases. Therefore, this STXM method is proposed as a promising approach for better DG identification and diagnosis, as a complementary tool to the current WM TEM approach.

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Microanalysis of precipitates in a ferritic steel

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100110234 ◽

1978 ◽

Vol 36 (1) ◽

pp. 618-619

Author(s):

J.M. Titchmarsh

Keyword(s):

Ferritic Steel ◽

Particle Identification ◽

Energy Dispersive ◽

Objective Lens ◽

Ferritic Steels ◽

Replica Technique ◽

X Ray ◽

Large Numbers ◽

Scanning Transmission ◽

Made In

The advances in recent years in the microanalytical capabilities of conventional TEM's fitted with probe forming lenses allow much more detailed investigations to be made of the microstructures of complex alloys, such as ferritic steels, than have been possible previously. In particular, the identification of individual precipitate particles with dimensions of a few tens of nanometers in alloys containing high densities of several chemically and crystallographically different precipitate types is feasible. The aim of the investigation described in this paper was to establish a method which allowed individual particle identification to be made in a few seconds so that large numbers of particles could be examined in a few hours.A Philips EM400 microscope, fitted with the scanning transmission (STEM) objective lens pole-pieces and an EDAX energy dispersive X-ray analyser, was used at 120 kV with a thermal W hairpin filament. The precipitates examined were extracted using a standard C replica technique from specimens of a 2¼Cr-lMo ferritic steel in a quenched and tempered condition.

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High-resolution x-ray imaging of small copper-rich precipitates in steels

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100104704 ◽

1988 ◽

Vol 46 ◽

pp. 528-529

Author(s):

J. R. Michael ◽

K. A. Taylor

Keyword(s):

Electron Microscopy ◽

Thermomechanical Processing ◽

Atom Probe ◽

Ferrite Matrix ◽

Scanning Transmission Electron Microscope ◽

Probe Field ◽

X Ray ◽

Subsequent Transformation ◽

Transmission Electron ◽

Scanning Transmission

Although copper is considered an incidental or trace element in many commercial steels, some grades contain up to 1-2 wt.% Cu for precipitation strengthening. Previous electron microscopy and atom-probe/field-ion microscopy (AP/FIM) studies indicate that the precipitation of copper from ferrite proceeds with the formation of Cu-rich bcc zones and the subsequent transformation of these zones to fcc copper particles. However, the similarity between the atomic scattering amplitudes for iron and copper and the small misfit between between Cu-rich particles and the ferrite matrix preclude the detection of small (<5 nm) Cu-rich particles by conventional transmission electron microscopy; such particles have been imaged directly only by FIM. Here results are presented whereby the Cu Kα x-ray signal was used in a dedicated scanning transmission electron microscope (STEM) to image small Cu-rich particles in a steel. The capability to detect these small particles is expected to be helpful in understanding the behavior of copper in steels during thermomechanical processing and heat treatment.

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