japans disater

Japan raced to avert a catastrophe on Wednesday after an explosion at a quake-crippled nuclear power plant sent radiation wafting into Tokyo, prompting some people to flee the capital and others to stock up on essential supplies.The crisis escalated late on Tuesday when operators of the facility said one of two blasts had blown a hole in the building housing a reactor, which meant spent nuclear fuel was exposed to the atmosphere.Prime Minister Naoto Kan urged people within 18 miles of the facility — a population of 140,000 — to remain indoors, as Japan grappled with the world’s most serious nuclear accident since the Chernobyl disaster in Ukraine in 1986.Officials in Tokyo — 240 km (150 miles) to the south of the plant — said radiation in the capital was 10 times normal at one point but was not a threat to human health in the sprawling high-tech city of 13 million people.Toxicologist Lee Tin-lap at the Chinese University of Hong Kong said such a radiation level was not an immediate threat to people but the long-term consequences were unknown. TOKYO — Japan’s northeastern coast was a swampy wasteland of broken houses, overturned cars, sludge and dirty water Saturday as the nation awoke to the devastating aftermath of one of its greatest disasters, a powerful tsunami created by one of the strongest earthquakes ever recorded.The death toll from Friday’s massive magnitude 8.9 quake stood at more than 200, but an untold number of bodies were believed to be lying in the rubble and debris, and Japanese were bracing for more bad news as authorities tried to reach the hardest-hit areas.

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Making a better artificial intestine

Scientist have figured out how to re-create the finger-like projections in the human intestine.

Scientists have long grown cells in flat dishes, which is handy if you’re studying flat tissues. But organs have bulges and ridges and other shapes, and growing cells to mimic that geometry has been a challenge. Now, researchers have come up with a simple way to raise cells in tall, thin columns that better re-create the natural structure of the human intestine.

It should prove useful in lab studies and perhaps someday in people without enough intestine of their own, says Dr. Daniel Teitelbaum, a gastrointestinal surgeon at the University of Michigan Medical School in Ann Arbor, who was not involved in the study.

The intestine isn’t just a smooth tube: Finger-like projections called villi make the interior of the organ look more like a lush, grassy lawn. These projections give the intestine more surface area to absorb nutrients from food.

Growing cells in a flat dish misses out on many features of this 3-D system, says study author John March, an assistant professor of biological and environmental engineering at Cornell University in Ithaca, N.Y. It’s like trying to understand high-rise apartment living by examining suburban bungalows — you’d learn a few things, but you’d miss out on a lot too.

For example, in the real three-dimensional intestine, the amounts of oxygen, bacteria and secretions vary from the tops of the villi to their crowded-together bottoms, says William Bentley, a bioengineer at the University of Maryland in College Park who was not involved in the study. That affects how the organ works and how nutrients are absorbed.

Scientists are working on all kinds of methods to grow cells in 3-D, but until now, the best artificial intestines have come out looking kind of “dome-y,” March says, instead of tall and thin. He and his lab mates solved the problem by growing the cells, high-rise-style, on a soft gel scaffold made of collagen, one of the body’s natural structural materials.

The Wind and Sun

By Logan Holmes[1]