Cashew shells can be used to mop up heavy metals. Nature India reports that researchers have developed an absorbent material from chemically modified cashew nut shells, an agricultural waste product, which is able to remove harmful heavy metals such as copper, cadmium, nickel, and zinc from aqueous solutions. This kind of sustainable solution for cleaning up industrial waste deserves cheers from the peanut gallery.
I happened to be in Manhattan earlier this week and caught the last day of the New-York Historical Society exhibit “Breakthrough: The Dramatic Story of the Discovery of Insulin.” My favorite part was the black-and-white silent movie showing the early insulin-manufacturing process, in which refrigerator carloads of fetal calf pancreases are ground up, pressed, filtered, and purified to produce the life-saving extract. Before 1921, the glands had been a waste product in stockyards around the country. After Eli Lilly and Company began buying them up from meat-packing houses, this offal became a precious commodity overnight; ten thousand pounds of pancreases were needed to make one pound of insulin crystals. (It wasn’t until the 1960s that the first synthetic insulin was produced. Today, most insulin used is biosynthetic recombinant “human” insulin.)
Many of these historical images appear in the recently published Breakthrough: Elizabeth Hughes, the Discovery of Insulin, and the Making of a Medical Miracle (St. Martin’s Press) by Thea Cooper and Arthur Ainsberg. Their account of this fascinating story is fluidly written and loaded with complex characters and details of a bygone era. They focus on four primary researchers and Hughes, who was the daughter of a prominent politician and the first American to receive insulin treatment for juvenile diabetes. Even though we know the outcome before we even pick up the book, the back story of this hinge point in medical history is compelling reading.
But the book will never have the clout of historian Michael Bliss’s award-winning The Discovery of Insulin, which was just reissued in a 25th anniversary edition (and to which Ainsberg and Cooper are indebted). That’s because Breakthrough is part history and part historical fiction. The authors even cop to fabrications in their preface, admitting that some dialog, incidents, and even a character “have been invented or augmented for narrative purposes.”
This beautiful image of a banded garden spider caught my eye before I realized that this story was about one of my favorite subjects – biomimicry. In this case, researchers are trying to figure out the properties of the glue-like substance that spiders deposit along the rings of silk in their webs that give the web its stickiness.
This is one the many fascinating biomimicry projects in an emerging field of devoted to the study and imitation of nature’s remarkably efficient designs. Scientists around the world are trying to unlock the evolutionary secrets of nature to develop such practical applications as wound healing inspired by flies, vaccines without refrigeration inspired by the resurrection plant, and water-resistant glues inspired by the tenacious adhesive properties of mussels.
It’s well-known that silk is, by weight, stronger than steel. By finding out precisely what makes spider webs so sticky, professor Ali Dhinojwala of the University of Akron, hopes to create more efficient and environment-friendly materials based on natural material, particularly bandages and other “bio-adhesives” that must retain their stickiness when in contact with water. An expert in the surface properties of polymers, Dhinojwala has also helped design synthetic carbon nanotube-based (in other words, glue-less) adhesive tapes inspired by another critter known for its stickiness– geckos. This time he’s investigating the microscopic substance that orb-weaving spiders deposit along the round rings of silk they spin as part of their webs. Those droplets–three times thinner than the diameter of a single hair–capture the flies and other insects that spiders eat. Turns out those drops, composed of highly entangled polymers, are both viscous and elastic. For details and a cool video, click here.
photo credit: Allison Hazen
While we’re on the subject, I urge everyone on this planet to go see the IMAX film Hubble 3D. In 2009, a crew of NASA astronauts took a mission to repair the Hubble Space Telescope. As they’ve done for the past 25 years, they took along an IMAX camera. This footage provides one of the most intimate looks into day-to-day life aboard a spaceship, which is by turns banal and hair-raising. Some folks might not think that watching astronauts scramble to find a lost screw in zero gravity is very fascinating, but my 5-year-old son loved it.
Then comes the big payoff: astonishingly detailed and clear images from distant galaxies taken by the repaired and upgraded Hubble. (more…)