Reconstruction of the Nanoscale Three-Dimensional Mass-Density Autocorrelation Function of Individual Cells

Abstract

Interrogating cellular nano-architecture may help reveal previously unknown structure-function relations. The three-dimensional mass-density distribution plays an important role in quantifying cellular structure. For instance, chromatin structure can be directly represented by the mass-density, as the individual molecules have similar mass and larger density generally indicates higher level of compaction. Chromatin compaction, in turn, is associated with gene transcription and is crucial in various aspects of fundamental biology, genetics, and oncology studies [1]. Moreover, it has been reported that a statistical representation of mass-density distribution by autocorrelation function (ACF) is crucial in stratifying risk of cancer in early stages [2]. Recent developments such as Partial Wave Spectroscopy [3] have gained success in cancer diagnosis by detecting three-dimensional sub-diffraction chromatin mass-density ACF alterations between malignant cells and healthy cells for various types of cancers.

Windowless Observation of Evaporation-Induced Coarsening of Au–Pt Nanoparticles in Polymer Nanoreactors

“…By analyzing the HAADF movie of sequential scans, where the signal intensity quantified the projected mass for each pixel, [54][55][56] it was revealed that the polymer is non-uniformly removed by electron irradiation at the nanoscale. At the beginning of the movie, the width of the polymer features gradually shrank, and voids were generated with lower signal intensity (Figure 3A, first row; and Figure 3B, stage 1) creating thin (~10 nm wide) polymer filaments that were then rapidly removed (Figure 3A, middle row; and Figure 3B, stage 2).…”