Chemistry Briefs

Spectroscopy reveals how Oxygen harms hydrogenases

New light has been shed on how hydrogen producing enzymes are harmed by oxygen, a byproduct of the reaction, based on research out of Ruhr University Bochum.

Using spectroscopy methods involving x-rays, the researchers tracked how long it took the iron core of the enzyme to become inactivated by increasing levels of oxygen. As with other hydrogenases, enzymes that split water molecules into hydrogen and oxygen are susceptible to attack by oxygen dissolved in its surrounding medium.

Specifically, the inactivation involved three phases. In the first phase, oxygen binds to one part of the iron core leading to the production of very reactive oxygen species. The reactive oxygen then attacks the iron center, modifying the irons present. Lastly, more oxygen molecules come in and cause the entire complex to fall apart.

Researchers hope to apply their results towards developing enzymes that can overcome this flaw induced by rising oxygen levels.

Glucose test uses tears to measure blood sugar levels

Researchers developed a test for glucose levels using the tears of laboratory rabbits. While current blood glucose screens rely on blood pricks that are uncomfortable for diabetes patients, this new test out of the University of Michigan Ann Arbor may someday provide a less painful alternative mode of testing. Their findings are published in the American Chemical Society's journal Analytical Chemistry.

The researchers found that tears in rabbits contain levels of glucose that correspond to the levels in the blood over the course of their eight hour observation period. Their sensor is optimized to very low detection limits and only requires a minute amount of tears, about four to five microliters, to give an accurate reading.

New names for elements 110, 111 and 112 given approval

Official names for three elements at the bottom the periodic table have been approved by the General Assembly of the International Union of Pure and Applied Physics, convening in the Institute of Physics in London. These super-heavy elements are especially unstable and rapidly decay.

Element 110 has been named darmstadtium after the city of Darmstadt, Germany. Roentgenium is the new name for element 111, recognizing the German physicist Wilhelm Conrad Roentgen, who was the first person to produce and detect x-rays back in 1895. Nicholas Copernicus, the astronomer who first proposed that the Earth revolves around the sun, is honored in the naming of element 112 as copernicium.

Darmstandtium was first created in 1994 at the GSI facility near Darmstadt through the collision of nickel-62 with a heavy isotope of lead. Roentgenium was produced a month later at the same facility when scientists collided Nickel ions with Bismuth. Copernicium was first created in 1996 at the GSI facility as well through the collision of zinc and lead.