Kevin Raines

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The ability to determine the structure of matter in three dimensions has profoundly advanced our understanding of nature. Traditionally, the most widely used schemes for three-dimensional (3D) structure determination of an object are implemented by acquiring multiple measurements over various sample orientations, as in the case of crystallography and(More)
We present what we believe to be the first implementation of Fourier transform (FT) holography using a tabletop coherent x-ray source. By applying curvature correction to compensate for the large angles inherent in high-NA coherent imaging, we achieve image resolution of 89 nm using high-harmonic beams at a wavelength of 29 nm. Moreover, by combining(More)
Tabletop coherent x-ray sources hold great promise for practical nanoscale imaging, in particular when coupled with diffractive imaging techniques. In initial work, we demonstrated lensless diffraction imaging using a tabletop high harmonic generation (HHG) source at 29 nm, achieving resolutions ~200 nm. In recent work, we significantly enhanced our(More)
A structural understanding of whole cells in three dimensions at high spatial resolution remains a significant challenge and, in the case of X-rays, has been limited by radiation damage. By alleviating this limitation, cryogenic coherent diffractive imaging (cryo-CDI) can in principle be used to bridge the important resolution gap between optical and(More)
Since the first demonstration of coherent diffraction microscopy in 1999, this lensless imaging technique has been experimentally refined by continued developments. Here, instrumentation and experimental procedures for measuring oversampled diffraction patterns from non-crystalline specimens using an undulator beamline (BL29XUL) at SPring-8 are presented.(More)
We demonstrate that high numerical aperture coherent diffractive imaging enables three-dimensional imaging from a single exposure angle under certain conditions. We demonstrate this technique, called ankylography, with simulations and experiment from a tabletop soft-x-ray laser.
During X-ray exposure of a molecular solution, photons scattered from the same molecule are correlated. If molecular motion is insignificant during exposure, then differences in momentum transfer between correlated photons are direct measurements of the molecular structure. In conventional small- and wide-angle solution scattering, photon correlations are(More)
Mature microRNAs (miRNA) are short (∼ 22 nucleotide), single-stranded, noncoding RNA strands that regulate gene expression. MiRNA expression in tissues is increasingly used to classify cell states and show promise as clinical biomarkers for diagnostics. In this report, we summarize our experience using three different Machine Learning (ML) algorithms to(More)
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