As every year Science Magazine and the National Science Foundation present the winners of the International Science and Engineering Visualization Challenge.
1° place: Metabolomic Eye
Eyeballs—now in Technicolor. This photo graph, taken by neuroscientist Bryan Jones of the University of Utah’s Moran Eye Center (MEC) in Salt Lake City, may look like a piece of candy. But it’s actually a metabolic look at the wide diversity of cells in the mouse eye—in all, 70 different types of cells, from muscles to retina, each colored a unique shade.
To map out the tissues in this mouse’s eye, Jones turned to a technique called computational molecular phenotyping (CMP). This approach, pioneered by Robert Marc, also at MEC, takes advantage of the unique array of molecules in all cells in a tissue. “Within a cell type, there is a very narrowly regulated fingerprint that defines who that cell is and what that cell does,” Jones says. In this case, he probed the relative concentrations of several common organic molecules.
Using a tool that cuts into biological material on the microscopic scale, Jones shaved into the eye, creating serial 120-nanometer-thick slices, thinner than the wavelength of light—much like licking a gobstopper, he says. Jones then stained those layers with specialized antibodies that bind to three molecules: taurine, glutamine, and glutamate, which he assigned to red, green, and blue color channels on a computer. The unique distributions of these molecules can be seen here in rainbow color. Muscle cells, located at the left edge of the image, look pale yellow, whereas scleral tissue, surrounding the entire orb, shows up green in this image.
In order to study the molecular fingerprints of specific tissues, scientists previously had to grind up entire organs and analyze the cells all together. That turned what might be a metabolically diverse organ into a homogenous mess, Jones says. But CMP highlights a tissue’s complexity. “There’s incredible diversity in a cell population normally thought to be homogenous.” And mammal eyes aren’t even the most complex retinas out there, he adds. Goldfish eyes, for instance, contain more than 200 separate cell types.
The photograph is certainly eye-catching, says challenge judge Alisa Zapp Machalek. “It was just what we were looking for,” she says. “It was the perfect balance between a beautiful picture that tingles the eyeballs and something that is incredibly informative.”
2° place: Microscopic Image of Trichomes on the Skin of an Immature Cucumber
No, this photograph doesn’t depict alien slugs stripped from a science-fiction film—just the surface of a young cucumber. It’s a new perspective on an old vegetable. To take this close-up, vibrant shot, photographer Robert Belliveau employed a polarizing microscope. Unlike normal light microscopes, which use unpolarized light, these zooming tools adopt plane-polarized light and record the refraction of light as it passes through small objects to produce a sharp, colorful image.
The structures shown here at 800× magnification are trichomes. They coat the surface of still-growing cucumbers and look, to the naked eye, like a thin film of hair. That fuzziness, however, belies the structures’ nasty streak. The tips of trichomes taper to a point that can pierce the mouths of predators, and their bulbous bases are filled with bitter-tasting and toxic molecules called cucurbitacins. It’s a dangerous and strange landscape that humans normally don’t get to see, says Belliveau, who has also turned his microscope on tomatoes and many other edible plants. “The microscopic world of plants, especially fruits and vegetables, is such an exotic world,” he says. “It’s actually otherworldly.”
3° place: The Cliff of the Two-Dimensional World
This landscape, which looks like a red-rock bluff straight out of Utah, isn’t a geologic feature. Instead, it’s a nanostructured material made from ultrathin layers of titanium-based compounds and seen under an electron microscope.
To construct the small outcropping, Babak Anasori and colleagues at Drexel University in Philadelphia used a technique called exfoliation. They placed Ti3AlC2 powders in a solution of hydrofluoric acid and stripped away the aluminum atoms. What remained were stacked layers of Ti3C2, seen here in false color, resembling stratigraphic mineral layers. These exfoliated layers, which the team dubbed MXenes, are so thin they are two-dimensional. In other words, each strip is only five atomic layers thick. The team is the first to render such materials in 2D. The MXenes could be used in energy storage devices, sensors, solar cells, and other applications, the team writes. And they could give the majesty of Arches National Park in Utah some nanoscale competition.