scholarly journals Characterization of Cell-Induced Astigmatism inHigh-Resolution Imaging

2021 ◽  
Author(s):  
Rick Rodrigues de Mercado ◽  
Hedde van Hoorn ◽  
Martin de Valois ◽  
Claude Backendorf ◽  
Julia Eckert ◽  
...  
2021 ◽  
Author(s):  
Rick Rodrigues de Mercado ◽  
Hedde van Hoorn ◽  
Martin de Valois ◽  
Claude Backendorf ◽  
Julia Eckert ◽  
...  

High-resolution and super-resolution techniques become more frequently used in thick, inhomogeneous samples. In particular for imaging life cells and tissue in which one wishes to observe a biological process at minimal interference and in the natural environment, sample inhomogeneities are unavoidable. Yet sample-inhomogeneities are paralleled by refractive index variations, for example between the cell organelles and the surrounding medium, that will result in the refraction of light, and therefore lead to sample-induced astigmatism. Astigmatism in turn will result in positional inaccuracies of observations that are at the heart of all super-resolution techniques. Here we introduce a simple model and define a figure-of-merit that allows one to quickly assess the importance of astigmatism for a given experimental setting. We found that astigmatism caused by the cell's nucleus can easily lead to aberrations up to hundreds of nanometers, well beyond the accuracy of all super-resolution techniques. The astigmatism generated by small objects, like bacteria or vesicles, appear to be small enough to be of any significance in typical super-resolution experimentation.


1997 ◽  
Vol 12 (10) ◽  
pp. 2617-2622 ◽  
Author(s):  
Mehmet A. Akbas ◽  
Peter K. Davies

Using a processing route that employed platinum crucibles, single phase ceramics of Pb(Mg1/3Ta2/3)O3 (PMT) relaxor ferroelectrics were prepared with densities greater than 95% of their theoretical value. The improvements in the sintering characteristics of this system that result from this route were reflected by the dielectric properties, at 182 K, which are similar to those reported for single crystal PMT. Contrast originating from nanosized polar clusters was evident in dark-field TEM images collected from the PMT ceramics at room temperature and showed little change upon cooling through the permittivity maximum. The electron diffraction patterns contained weak superlattice reflections at (h ± 1/2, k ± 1/2, l ± 1/2) that originate from a 1: 1 ordering of the B-site cations. High resolution imaging indicated that the length scale of the chemical ordering in PMT is essentially identical to niobate relaxors such as PMN, with the 1–2 nm ordered domains being surrounded by a disordered matrix.


Author(s):  
Felix JH Hol ◽  
Louis Lambrechts ◽  
Manu Prakash

AbstractFemale mosquitoes need a blood meal to reproduce, and in obtaining this essential nutrient they transmit deadly pathogens. Although crucial for the spread of mosquito-borne diseases, our understanding of skin exploration, probing, and engorgement, is limited due to a lack of quantitative tools. Indeed, studies often expose human subjects to assess biting behavior. Here, we present the biteOscope, a device that attracts mosquitoes to a host mimic which they bite to obtain an artificial blood meal. The host mimic is transparent, allowing high-resolution imaging of the feeding mosquito. Using machine learning we extract detailed behavioral statistics describing the locomotion, pose, biting, and feeding dynamics of Aedes aegypti, Aedes albopictus, Anopheles stephensi, and Anopheles coluzzii. In addition to characterizing behavioral patterns, we discover that the common insect repellent DEET repels Anopheles coluzzii upon contact with their legs. The biteOscope provides a new perspective on mosquito blood feeding, enabling high-throughput quantitative characterization of the effects physiological and environmental factors have on this lethal behavior.


MRS Bulletin ◽  
2021 ◽  
Author(s):  
Haimei Zheng

AbstractThe development of liquid cells for transmission electron microscopy has enabled breakthroughs in our ability to follow nanoscale structural, morphological, or chemical changes during materials growth and applications. Time-resolved high-resolution imaging and chemical analysis through liquids opened the opportunity to capture nanoscale dynamic processes of materials, including reaction intermediates and the transformation pathways. In this article, a series of work is highlighted with topics ranging from liquid cell developments to in situ studies of nanocrystal growth and transformations, dendrite formation, and suppression of lithium dendrites through in situ characterization of the solid–electrolyte interphase chemistry. The understanding garnered is expected to accelerate the discovery of novel materials for applications in energy storage, catalysis, sensors, and other functional devices.


2017 ◽  
Vol 80 ◽  
pp. 1-10 ◽  
Author(s):  
Marc Staal ◽  
Nadia Farhat ◽  
Mark van Loosdrecht ◽  
Johannes Vrouwenvelder

2019 ◽  
Vol 116 (3) ◽  
pp. 231a ◽  
Author(s):  
Peter Lin ◽  
Jared Westreich ◽  
Mengyuan Li ◽  
Adam Gribble ◽  
Susan Newbigging ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document