2 research outputs found
Analysis of the Distribution Pattern of Chromium Species in Single Cells
The
patterning of distribution models for specific heavy metal
species in biological cells is highly important for elucidating their
effect on single cells or in a living organism. For this purpose,
the variation of chromium levels and the distribution patterns of
chromium species in single-cell subjects are investigated by culturing
two kinds of native cells (i.e., HeLa cells and MCF-7 cells) in the
presence of either CrÂ(III) or CrÂ(VI). The analysis of single cells
is performed with time-resolved inductively coupled plasma mass spectrometry.
We found that the total chromium level in the single cells after culturing
in a CrÂ(VI)-enriched medium is higher than that for those single cells
cultured in a CrÂ(III)-reinforced medium. It is interesting to see
that at certain culturing conditions, the chromium level in single
individual cells increases linearly with CrÂ(III) concentration in
the culture medium, whereas it increases exponentially with CrÂ(VI)
concentration. This indicated that CrÂ(VI) is more prone to penetrate
the cells with respect to CrÂ(III), and after a concentration threshold,
considerably more CrÂ(VI) enters into the interior of HeLa cells or
MCF-7 cells
Controlling the Reaction of Nanoparticles for Hollow Metal Oxide Nanostructures
Hollow
nanostructures of metal oxides have found broad applications
in different fields. Here, we reported a facile and versatile synthetic
protocol to prepare hollow metal oxide nanospheres by modulating the
chemical properties in solid nanoparticles. Our synthesis design starts
with the precipitation of urea-containing metal oxalate, which is
soluble in water but exists as solid nanospheres in ethanol. A controlled
particle hydrolysis is achieved through the heating-induced urea decomposition,
which transforms the particle composition in an outside-to-inside
style: The reaction starts from the surface and then proceeds inward
to gradually form a water-insoluble shell of basic metal oxalate.
Such a reaction-induced solubility difference inside nanospheres becomes
highly efficient to create a hollow structure through a simple water
wash process. A following high temperature treatment forms hollow
nanospheres of different metal oxides with structural features suited
to their applications. For example, a high performance anode for Li-ion
intercalation pseudocapacitor was demonstrated with the hollow and
mesoporous Nb<sub>2</sub>O<sub>5</sub> nanospheres