7 research outputs found
Quantitative Imaging of Single Unstained Magnetotactic Bacteria by Coherent X‑ray Diffraction Microscopy
Novel coherent diffraction microscopy
provides a powerful lensless
imaging method to obtain a better understanding of the microorganism
at the nanoscale. Here we demonstrated quantitative imaging of intact
unstained magnetotactic bacteria using coherent X-ray diffraction
microscopy combined with an iterative phase retrieval algorithm. Although
the signal-to-noise ratio of the X-ray diffraction pattern from single
magnetotactic bacterium is weak due to low-scattering ability of biomaterials,
an 18.6 nm half-period resolution of reconstructed image was achieved
by using a hybrid input-output phase retrieval algorithm. On the basis
of the quantitative reconstructed images, the morphology and some
intracellular structures, such as nucleoid, polyβ-hydroxybutyrate
granules, and magnetosomes, were identified, which were also confirmed
by scanning electron microscopy and energy dispersive spectroscopy.
With the benefit from the quantifiability of coherent diffraction
imaging, for the first time to our knowledge, an average density of
magnetotactic bacteria was calculated to be ∼1.19 g/cm<sup>3</sup>. This technique has a wide range of applications, especially
in quantitative imaging of low-scattering biomaterials and multicomponent
materials at nanoscale resolution. Combined with the cryogenic technique
or X-ray free electron lasers, the method could image cells in a hydrated
condition, which helps to maintain their natural structure
EDS results of the elemental analysis of the casting mold sherd.
<p>EDS results of the elemental analysis of the casting mold sherd.</p
Map of the Shang Dynasty and location of Daxinzhuang.
<p>Both Yin Ruins and Daxinzhuang sites are marked in the map. Reprinted from [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0174057#pone.0174057.ref011" target="_blank">11</a>] under a CC BY license, with permission from [Lamassu Design], original copyright [2009].</p
X-ray fluorescence mapping of copper and iron mapping in front decoration and back groove.
<p>(A) A groove is labelled by a white rectangle on the back of the casting mold sherd. One red dashed line indicates the deepest position in the groove. (B) X-ray fluorescence mapping of the copper on the back and a white dashed line encircles the groove. (C) X-ray fluorescence mapping of the iron on the back and a black dashed line encircles the groove. One side of the deepest line shows a gathering of iron, and on the other side, this reverses. (D) A probing range is labelled by a white rectangle on the front of the casting mold sherd. (E), (F) X-ray fluorescence mapping on the front decoration of copper and iron, respectively. Both elements have an uneven distribution and some correspondence to the profile of decorated patterns.</p
AMS-<sup>14</sup>C dating of archaeological pig bone.
<p>AMS-<sup>14</sup>C dating of archaeological pig bone.</p