Imaging through scattering media is challenging since the signal to noise ratio (SNR) of the reflection can be heavily reduced by scatterers. Single-pixel detectors (SPD) with high sensitivities offer compelling advantages for sensing such weak signals. In this paper, we focus on the use of ghost imaging to resolve 2D spatial information using just an SPD. We prototype a polarimetric ghost imaging system that suppresses backscattering from volumetric media and leverages deep learning for fast reconstructions. In this work, we implement ghost imaging by projecting Hadamard patterns that are optimized for imaging through scattering media. We demonstrate good quality reconstructions in highly scattering conditions using a 1.6% sampling rate.

Three-dimensional tissue cultures have been used as effective models for studying different diseases including epilepsy. High-throughput, non-destructive techniques are essential for rapid assessment of disease-related processes such as progressive cell death. In this study, an ultrahigh-resolution optical coherence microscopy (UHR-OCM) system with ~1.5-μm axial resolution and ~2.3-μm transverse resolution was developed to evaluate seizure-induced neuronal injury in organotypic rat hippocampal cultures. The capability of UHR-OCM to visualize cells in neural tissue was confirmed by comparison of UHR-OCM images with confocal immunostained images of the same cultures. In order to evaluate the progression of neuronal injury, UHR-OCM images were obtained from cultures on 7, 14, 21 and 28 days-in-vitro (DIVs). In comparison to DIV 7, statistically significant reductions in 3D cell count and culture thickness from UHR-OCM images were observed on subsequent time points. In cultures treated with kynurenic acid (KYNA), significantly less reduction in cell count and culture thickness was observed compared to control specimens. These results demonstrate the capability of UHR-OCM to perform rapid, label-free, and non-destructive evaluation of neuronal death in organotypic hippocampal cultures. UHR-OCM, in combination with three-dimensional tissue cultures, can potentially prove to be a promising tool for high throughput screening of drugs targeting various disorders.

No abstract

A significant number of oil paintings produced by Georgia O' Keeffe (1887Keeffe ( -1986 show surface protrusions of varying width, up to several hundreds of microns. These protrusions are similar to those described in the art conservation literature as metallic soaps. Since the presence of these protrusions raises questions about the state of conservation and long-term prospects for deterioration of these artworks, a 3D-imaging technique, photometric stereo using ultraviolet illumination, was developed for the long-term monitoring of the surface-shape of the protrusions and the surrounding paint.Because the UV fluorescence response of painting materials is isotropic, errors typically 1 arXiv:1711.08103v1 [cs.GR] 22 Nov 2017 caused by non-Lambertian (anisotropic) specularities when using visible reflected light can be avoided providing a more accurate estimation of shape. As an added benefit, fluorescence provides additional contrast information contributing to materials characterization. The developed methodology aims to detect, characterize, and quantify the distribution of micro-protrusions and their development over the surface of entire artworks. Combined with a set of analytical in-situ techniques, and computational tools, this approach constitutes a novel methodology to investigate the selective distribution of protrusions in correlation with the composition of painting materials at the macroscale. While focused on O'Keeffe's paintings as a case study, we expect the proposed approach to have broader significance by providing a non-invasive protocol to the conservation community to probe topological changes for any relatively flat painted surface of an artwork, and more specifically to monitor the dynamic formation of protrusions, in relation to paint composition and modifications of environmental conditions, loans, exhibitions and storage over the long-term.

No abstract