Determining what really counts: modeling and measuring nanoparticle number concentrations

2019 ◽  
Vol 6 (9) ◽  
pp. 2876-2896 ◽  
Author(s):  
Elijah J. Petersen ◽  
Antonio R. Montoro Bustos ◽  
Blaza Toman ◽  
Monique E. Johnson ◽  
Mark Ellefson ◽  
...  

This paper describes a comprehensive investigation of particle number concentrations including a multi-method comparison, theoretical modeling, and cellular dosimetry.

Author(s):  
H.J.G. Gundersen

Previously, all stereological estimation of particle number and sizes were based on models and notoriously gave biased results, were very inefficient to use and difficult to justify. For all references to old methods and a direct comparison with unbiased methods see recent reviews.The publication in 1984 of the DISECTOR, the first unbiased stereological probe for sampling and counting 3—D objects irrespective of their size and shape, signalled the new era in stereology — and give rise to a number of remarkably simple and efficient techniques based on its distinct property: It is the only known way to obtain an unbiased sample of 3-D objects (cells, organelles, etc). The principle is simple: within a 2-D unbiased frame count or sample only cells which are not hit by a parallel plane at a known, small distance h.The area of the frame and h must be known, which might sometimes in itself be a problem, albeit usually a small one. A more severe problem may arise because these constants are known at the scale of the fixed, embedded and sectioned tissue which is often shrunken considerably.


Author(s):  
Amreek Singh ◽  
Warren G. Foster ◽  
Anna Dykeman ◽  
David C. Villeneuve

Hexachlorobenzene (HCB) is a known toxicant that is found in the environment as a by-product during manufacture of certain pesticides. This chlorinated chemical has been isolated from many tissues including ovary. When administered in high doses, HCB causes degeneration of primordial germ cells and ovary surface epithelium in sub-human primates. A purpose of this experiment was to determine a no-effect dose of the chemical on the rat ovary. The study is part of a comprehensive investigation on the effects of the compound on the biochemical, hematological, and morphological parameters in the monkey and rat.


Nanoscale ◽  
2020 ◽  
Vol 12 (45) ◽  
pp. 23028-23035
Author(s):  
Artem R. Khabibullin ◽  
Alexander L. Efros ◽  
Steven C. Erwin

Theoretical modeling of wavefunction overlap in nanocrystal solids elucidates the important role played by ligands in electron transport.


1997 ◽  
Vol 44 (10) ◽  
pp. 1801-1814 ◽  
Author(s):  
MARTIN WILKENS and CHRISTOPH WEISS

2005 ◽  
Vol 432 (1) ◽  
pp. 181-187 ◽  
Author(s):  
E. Meyer-Hofmeister ◽  
B. F. Liu ◽  
F. Meyer

2015 ◽  
pp. 123-140 ◽  
Author(s):  
O. Koshovets ◽  
T. Varkhotov

The paper considers the analogy of theoretical modeling and thought experiment in economics. The authors provide historical and epistemological analysis of thought experiments and their relations to the material experiments in natural science. They conclude that thought experiments as instruments are used both in physics and in economics, but in radically different ways. In the natural science, a thought experiment is tightly connected to the material experimentation, while in economics it is used in isolation. Material experiments serve as a means to demonstrate the reality, while thought experiments cannot be a full-fledged instrument of studying the reality. Rather, they constitute the instrument of structuring the field of inquiry.


Author(s):  
B. B. Shkursky

Theoretical modeling of regular olivine grains misorientations in mimetic paramorphoses after ringwoodite and wadsleyite, the formation of which during the ascension of matter from the Mantle Transition Zone is expected, has been carried out. The coordinates of the misorientation axes and the misorientation angles, characterizing 10 operations of alignment in the pair intergrowths of olivine grains, eight of which are twins, are calculated. Possible conditions for the formation of mimetic paramorphoses predicted here, and the chances of their persistence are discussed. The calculated orientations are compared with the known twinning laws of olivine.


2011 ◽  
Vol 8 (1) ◽  
Author(s):  
Wen-ying Sylvia Chou ◽  
Paul Han ◽  
Alison Pilsner ◽  
Kisha Coa ◽  
Larrie Greenberg ◽  
...  

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