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We derive a model that describes 3D volume imaging in depth-sectioning STEM that is valid for all STEM techniques under three well-defined conditions: linearity, undisturbed probe and elastic scattering. The resulting undisturbed probe model generalizes the widely used idea that the undisturbed probe intensity in three dimensions can be used as the point spread function for depth-sectioning ADF-STEM to all STEM techniques including (A)BF- and iDPC-STEM. The model provides closed expressions for depth-sectioning STEM, which follow directly from the 2D expressions for thin samples, and thereby enables analysis of the 3D resolution. Using the model we explore the consequences of the resulting 3D contrast transfer function (CTF) for the z-resolution at different length scales and illustrate this with experiments. We investigate the validity and limitations of the model using multi-slice simulations showing that it is valid and quantitatively accurate for relatively thick amorphous samples but not for crystalline samples in zone-axis due to channeling. We compare depth-sectioning in iDPC- and ADF-STEM and show that iDPC-STEM can extract information from deeper into the sample, all the way till the bottom of the sample, thereby effectively allowing a thickness measurement. Also the difference in optimal focus conditions between iDPC- and ADF-STEM is explained. Finally, we propose practical criteria for deciding whether a sample is thin or thick.
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Long-period patterns (LPPs) are widely observed by transmission electron microscopy (TEM) in the study of nanoscale materials. Identifying the origin of LPPs is of significant importance when interpre...
Optical clearing techniques and light sheet microscopy have transformed fluorescent imaging of rodent brains, and have provided a crucial alternative to traditional confocal or bright field techniques...
Advances in imaging systems and modeling allow for depth information to be retrieved from projections via virtual sectioning of the imaged object. Here we introduce a regridding method that explicitly...
Scanning diffraction uses the diffraction pattern from the sub-angstrom electron probe in scanning transmission electron microscopy (STEM) to record the probe's interaction with the sample structure. ...
Pituitary stalk sectioning is only essential in the cases of craniopharyngioma originating from the stalk or metastatic tumor to the stalk. Some patients can discontinue postoperative anti-diuretic ho...
Horizontal sectioning of scalp biopsy is a better method for evaluating hair disorders than vertical sectioning because it enables the quantitative examination of hair follicles at differe...
Currently there is no technique to produce thin (0.004-0.01 mm) serial sections of large fresh tissue specimens that are suitable for high-resolution in situ protein/gene expression studie...
RATIONALE: Collecting and storing samples of blood, urine, and tissue from patients undergoing a donor stem cell transplant to test in the laboratory may help the study of graft-versus-hos...
Squamous cell carcinoma (SCC) is a cancer that originates from the cells lining the body and can spread into the lymph glands and beyond. Some patients first present with an SCC which has ...
This is a single arm, non-randomized phase II study of neoadjuvant metformin in resectable PDAC. Twenty patients will be enrolled and treated with metformin 500 mg BD for a minimum of 7 da...
The simultaneous analysis, on a microchip, of multiple samples or targets arranged in an array format.
The simultaneous analysis of multiple samples of TISSUES or CELLS from BIOPSY or in vitro culture that have been arranged in an array format on slides or microchips.
The use of molecularly targeted imaging probes to localize and/or monitor biochemical and cellular processes via various imaging modalities that include RADIONUCLIDE IMAGING; ULTRASONOGRAPHY; MAGNETIC RESONANCE IMAGING; fluorescence imaging; and MICROSCOPY.
The preparation and analysis of samples on miniaturized devices.
Analysis based on the mathematical function first formulated by Jean-Baptiste-Joseph Fourier in 1807. The function, known as the Fourier transform, describes the sinusoidal pattern of any fluctuating pattern in the physical world in terms of its amplitude and its phase. It has broad applications in biomedicine, e.g., analysis of the x-ray crystallography data pivotal in identifying the double helical nature of DNA and in analysis of other molecules, including viruses, and the modified back-projection algorithm universally used in computerized tomography imaging, etc. (From Segen, The Dictionary of Modern Medicine, 1992)