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Your search keyword '"Wang, Hao A. O."' showing total 18 results
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18 results on '"Wang, Hao A. O."'

1. Gemmological Characterisation of Emeralds from Musakashi, Zambia, and Implications for Their Geographic Origin Determination.

Author

Krzemnicki, Michael S., Wang, Hao A. O., Wälle, Markus, Lefèvre, Pierre, Wei Zhou, and Cartier, Laurent E.

Subjects
*FLUID inclusions, *RAMAN spectroscopy, *MACHINE learning, *EMERALDS, *CHEMICAL properties
Abstract

Emeralds from the Musakashi area of Zambia entered the gem trade in early 2002 in rather small quantities. Faceted stones are mostly available in smaller sizes (1-5 ct) but occasionally reach up to 20 ct or more. They can be of very fine gem quality and exhibit similarities to Colombian emeralds, not only in appearance, but also in their gemmological properties, inclusion features and chemical properties. Seventy-eight Musakashi emeralds were characterised gemmologically and chemically for this report. They can be distinguished from Colombian emeralds (as well as other similar emeralds from Afghanistan's Panjshir Valley) based on certain diagnostic internal features (e.g. 'sawtooth'-outlined multiphase fluid inclusions) and their chemical composition (e.g. plotting Fe vs V/Cr, and cluster visualisation using a t-SNE machine-learning algorithm). Separating them from the classic schist-hosted emeralds of the Kafubu area in Zambia is straightforward based on differences in their gemmological properties, inclusions, UV-Vis-NIR and Raman spectra, and chemical composition. [ABSTRACT FROM AUTHOR]

Published
2024
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9. Automatic single cell segmentation on highly multiplexed tissue images

Author

Schüffler Peter J, Schapiro Denis, Giesen Charlotte, Wang Hao A O, Bodenmiller Bernd, and Buhmann Joachim M

Subjects
Diagnostic Imaging, ComputingMethodologies_PATTERNRECOGNITION, ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, Humans, Breast Neoplasms, Female, Single-Cell Analysis, Flow Cytometry, Immunohistochemistry
Abstract

The combination of mass cytometry and immunohistochemistry (IHC) enables new histopathological imaging methods in which dozens of proteins and protein modifications can be visualized simultaneously in a single tissue section. The power of multiplexing combined with spatial information and quantification was recently illustrated on breast cancer tissue and was described as next-generation IHC. Robust, accurate, and high-throughput cell segmentation is crucial for the analysis of this new generation of IHC data. To this end, we propose a watershed-based cell segmentation, which uses a nuclear marker and multiple membrane markers, the latter automatically selected based on their correlation. In comparison with the state-of-the-art segmentation pipelines, which are only using a single marker for object detection, we could show that the use of multiple markers can significantly increase the segmentation power, and thus, multiplexed information should be used and not ignored during the segmentation. Furthermore, we provide a novel, user-friendly open-source toolbox for the automatic segmentation of multiplexed histopathological images.

Published
2014

12. High-Speed, High-Resolution, Multielemental Laser Ablation-Inductively Coupled Plasma-Time-of-Flight Mass Spectrometry Imaging: Part I. Instrumentation and Two-Dimensional Imaging of Geological Samples

Author

Gundlach-Graham, Alexander, primary, Burger, Marcel, additional, Allner, Steffen, additional, Schwarz, Gunnar, additional, Wang, Hao A. O., additional, Gyr, Luzia, additional, Grolimund, Daniel, additional, Hattendorf, Bodo, additional, and Günther, Detlef, additional

Published
2015
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13. High-Speed, High-Resolution, Multielemental LA-ICP-TOFMS Imaging: Part II. Critical Evaluation of Quantitative Three-Dimensional Imaging of Major, Minor, and Trace Elements in Geological Samples

Author

Burger, Marcel, primary, Gundlach-Graham, Alexander, additional, Allner, Steffen, additional, Schwarz, Gunnar, additional, Wang, Hao A. O., additional, Gyr, Luzia, additional, Burgener, Simon, additional, Hattendorf, Bodo, additional, Grolimund, Daniel, additional, and Günther, Detlef, additional

Published
2015
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16. Highly multiplexed imaging of tumor tissues with subcellular resolution by mass cytometry

Author

Giesen, Charlotte, primary, Wang, Hao A O, additional, Schapiro, Denis, additional, Zivanovic, Nevena, additional, Jacobs, Andrea, additional, Hattendorf, Bodo, additional, Schüffler, Peter J, additional, Grolimund, Daniel, additional, Buhmann, Joachim M, additional, Brandt, Simone, additional, Varga, Zsuzsanna, additional, Wild, Peter J, additional, Günther, Detlef, additional, and Bodenmiller, Bernd, additional

Published
2014
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18. High spatial resolution quantitative imaging by cross-calibration using Laser Ablation Inductively Coupled Plasma Mass Spectrometry and Synchrotron micro-X-ray Fluorescence technique.

Author

Wang HA, Grolimund D, Van Loon LR, Barmettler KD, Borca CN, Aeschlimann B, and Günther D

Abstract

High spatial resolution, quantitative chemical imaging is of importance to various scientific communities, however high spatial resolution and robust quantification are not trivial to attain at the same time. In order to achieve microscopic chemical imaging with enhanced quantification capabilities, the current study links the independent and complementary advantages of two micro-analytical techniques - Synchrotron Radiation-based micro X-ray Fluorescence (SR-microXRF) and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICPMS). A cross-calibration approach is established between these two techniques and validated by one experimental demonstration. In the presented test case, the diffusion pattern of trace level Cs migrating into a heterogeneous geological medium is imaged quantitatively with high spatial resolution. The one-dimensional line scans and the two-dimensional chemical images reveal two distinct types of geochemical domains: calcium carbonate rich domains and clay rich domains. During the diffusion, Cs shows a much higher interfacial reactivity within the clay rich domain, and turns out to be nearly non-reactive in the calcium carbonate domains. Such information obtained on the micrometer scale improves our chemical knowledge concerning reactive solute transport mechanism in heterogeneous media. Related to the chosen demonstration study, the outcome of the quantitative, microscopic chemical imaging contributes to a refined safety assessment of potential host rock materials for deep-geological nuclear waste storage repositories.

Published
2012
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