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JONATHAN NACKSTRAND/AFP/GETTY IMAGES
JONATHAN NACKSTRAND/AFP/GETTY IMAGES

Nobel Prize in Chemistry Awarded for DNA Repair Research

JONATHAN NACKSTRAND/AFP/GETTY IMAGES
JONATHAN NACKSTRAND/AFP/GETTY IMAGES

Three scientists whose work greatly advanced our understanding of DNA repair have won the 2015 Nobel Prize in Chemistry. They share the prize equally. 

Their discoveries, the Nobel Prize committee said in a press statement [PDF], "have provided fundamental insights into how cells function, knowledge that can be used, for instance, in the development of new cancer treatments." 

Far from stable or pristine, our DNA is constantly battered by external forces like UV radiation, free radicals, and other carcinogens, along with internal instability. DNA molecules are also constantly changing; your genome is not what it was yesterday. Genetic problems can also arise from the replication of DNA during cell division, which happens in your body several million times a day.

DNA damage is constant; but so is its repair. A legion of proteins monitor your genes, proofreading the genome and making any necessary fixes. Without DNA repair, the Nobel Prize committee said, our genetic material would “disintegrate into complete chemical chaos.” They awarded the prize to three chemists, each of whom identified a different mechanism of repair.

Scientists used to believe that DNA was constant and unchanging. In the 1970s, Tomas Lindahl, of the Francis Crick Institute in the UK, demonstrated that DNA does, in fact, decay—at a rate that should have made the development of life on Earth impossible. Lindahl concluded that the damage must be repaired as quickly as it happens.

Over the next few decades, Lindahl would find some of the molecular mechanisms that carry out these repairs. He outlined the concept of base excision repair, a process by which damaged pieces of DNA are removed from the cell. In 1996, Lindahl successfully re-created the human DNA repair process in vitro.

There are two bacterial systems for fixing damaged DNA. One is dependent on ultraviolet (UV) light, and the other takes place in the dark. Biochemist Aziz Sancar, of the University of North Carolina, Chapel Hill, was awarded one third of the prize for his work illuminating the mechanisms of the dark system. Sancar developed the concept of nucleotide excision repair, the process by which enzymes find UV-damaged nucleotides, then snip them from the DNA strand. This form of repair is essential to our ability to recover from sun damage. 

A defect caused by an error in cell division is called a mismatch. Paul Modrich, a Howard Hughes Medical Institute (Maryland) investigator at Duke University, has spent his career studying the mechanisms of mismatch repair. In the 1980s, Modrich identified, cloned, and mapped numerous enzymes involved in the mismatch repair process. In 1989, he published a report on his successful recreation of the mismatch repair process in vitro. Defective mismatch repair systems are associated with a number of diseases, including a hereditary form of colon cancer.

The work of these awardees may lead to future treatments for cancer. “That is why curiosity-based research is so important,” Paul Modrich told the Nobel Prize committee [PDF]. “You never know where it is going to lead … a little luck helps, too.”

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The Elements
10 Quick Facts About Cobalt
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How well do you know the periodic table? Our series The Elements explores the fundamental building blocks of the observable universe—and their relevance to your life—one by one.

Cobalt hides out in everyday objects and happenings around us, from batteries and blue paint to medical procedures. We've used it for millennia, even before the common era, but it didn't get proper credit until the 18th century. With its 27 protons, cobalt is sandwiched between iron and nickel in the middle portion of the periodic table with the other "transition" metals, which bridge the main group elements located on either side. Here are ten curious facts about this element.

1. PURE COBALT DOES NOT NATURALLY EXIST ON EARTH.

Though you can find cobalt just about everywhere—in the soil, in mineral deposits, and even in crusts on the seafloor—it's always combined with other elements like nickel, copper, iron, or arsenic, such as in the bright crimson arsenate mineral erythrite. It's usually collected as a byproduct of mining for other metals—especially nickel and copper—and, once purified, is a burnished gray color.

2. COBALT MAY NOT BE RARE, BUT IT IS VALUABLE.

Despite being relatively common, it's considered a critical raw material by the European Union because there are few places where it's abundant enough to be mined in larger quantities. The only mine in the world where it's the primary product is in Morocco.

3. COBALT WAS NAMED AFTER SUBTERRANEAN GERMAN GOBLINS.

Centuries ago, miners in the mountains of Germany had a great deal of trouble trying to melt down certain ores for useful metals like silver and copper, and even dealt with poisonous fumes released from the rock, which could make them very sick or even kill them. They blamed the kobolds—pesky, underground sprites of local folklore (and more recently, the name of a Dungeons & Dragons species). Though the vapors actually arose from the arsenic also contained in the ores, when chemists later extracted cobalt from these minerals, the name stuck.

4. COBALT WAS FINALLY ISOLATED IN THE 18TH CENTURY.

It was not until the 1730s that Swedish chemist George Brandt purified and identified cobalt from arsenic-containing ores, then another 50 years until Torbern Bergman, another Swede, verified Brandt's new element. It is worth noting, though, that at the time the elements were simply in an incomplete list and had not been organized into a meaningful table.

5. COBALT IS BEST KNOWN FOR CREATING A RICH BLUE HUE…

People have been using cobalt-containing pigments to get that rich blue hue as far back as the 3rd millennium BCE, when Persians used them to color their necklace beads. From Egypt to China, artisans created blue glass from cobalt compounds for thousands of years. The color was long attributed to the element bismuth, depriving cobalt of pigment fame. 

6. … BUT COBALT MAKES OTHER COLORS TOO.

The famed "cobalt blue" is actually the result of the compound cobalt aluminate. Cobalt in other chemical combinations can also make a variety of other colors. Cobalt phosphate is used to make a violet pigment, and cobalt green is achieved by combining cobalt oxides with zinc oxides.

7. TODAY WE USE COBALT TO MAKE POWERFUL MAGNETS AND "SUPERALLOYS."

Cobalt is one of the few elements that are ferromagnetic, which means it can become magnetized when exposed to an external magnetic field. Cobalt remains magnetic at extremely high temperatures, making it very useful for the specialized magnets in generators and hard drives. When mixed with the right metals, cobalt can also help create materials called "superalloys" that keep their strength under huge stress and high temperatures—advantageous, for instance, in a jet engine. Most people, however, can find cobalt hiding closer to home, inside some rechargeable batteries.

8. COBALT COULD ONE DAY REPLACE PRECIOUS METALS IN INDUSTRY.

Scientists such as chemist Patrick Holland at Yale University are looking at ways to use cobalt in place of the more rare and expensive metals often used in industrial catalysts. These catalysts—chemical "helpers" that speed up reactions—are used in making adhesives, lubricants, or pharmaceutical precursors, for instance. Precious metals like platinum and iridium often make good catalysts, but they are also pricey, can be toxic to humans, and, as precious implies, are not abundant. There is a "big upswing in people looking at iron, nickel, and cobalt because of their price," Holland tells Mental Floss.

All three could be viable options in the future. The challenge, Holland says, is "walking the tightrope" between creating an effective, reactive catalyst and one that is too reactive or overly sensitive to impurities.

9. COBALT HAS MULTIPLE ROLES IN MODERN MEDICINE.

The metal perches in the middle of the impressively complex molecule vitamin B12—a.k.a. cobalamin—which is involved in making red blood cells and DNA, and helps keep your nervous system healthy. Cobalt also lends an extra distinction to B12: It's the only vitamin that contains a metal atom.

To measure B12 intake in patients, doctors use a "labeled" version of B12 in which the cobalt atom is replaced with a radioactive cobalt isotope. Oncologists and technicians also use the radiation from cobalt isotopes in some cancer therapies as well as to sterilize medical and surgical tools. These days, cobalt alloys are even found in artificial hip joints and knees.

10. COBALT WAS ONCE ADDED TO BEER—WITH DEADLY CONSEQUENCES.

In the 1960s, some breweries added cobalt chloride to their beers because it helped maintain the appealing foam that builds when beer is poured. By 1967, more than 100 heavy beer drinkers in Quebec City, Minneapolis, Omaha, and Belgium had suffered heart failure, and nearly half of them died. At the time, doctors were also administering cobalt to patients for medical reasons without causing this severe effect, so the blame couldn't lie with the metal alone. After studying the remains of the deceased, scientists proposed that the so-called "cobalt-beer cardiomyopathy" had been caused by an unhealthy mélange of cobalt, high alcohol intake, and poor diet. The FDA banned the use of cobalt chloride as a food additive shortly after. 

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Scientists Are Using an Ancient Egyptian Pigment to Create New Technologies 
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The ancient Egyptians famously built massive pyramids and developed hieroglyphics, but they're also credited with inventing the world's earliest-known artificial pigment. Today referred to as Egyptian blue, the deep azure shade was first created about 4600 years ago by heating together sand (containing quartz), minerals with copper, and natron, a salty mixture of sodium compounds used for embalming mummies. When ground together, this chemical concoction was a dead ringer for a pricier pigment made from a semi-precious blue stone called lapis lazuli, SciShow's Michael Aranda explains in the video below.

Egyptian blue was a popular color, and the hue appeared on coffins, pottery, and murals. But like most trends, the color fell out of fashion once red and yellow became big in Roman art. The pigment's recipe was lost until the 19th century, when scientists first began analyzing the chemical composition of artifacts bearing the ancient hue.

Scientists today know how to recreate Egyptian blue—but instead of using it to paint their labs, they're researching ways to incorporate the pigment into dyes for medical imaging techniques, creating new types of security ink, and even making dusting powder for fingerprint detection.

Learn how the newly discovered scientific properties of Egyptian blue can make these inventions possible by watching SciShow's video below.

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