Posts Tagged ‘body’

Gels that can be injected into the body, carrying drugs or cells that regenerate damaged tissue, hold promise for treating many types of disease, including cancer. However, these injectable gels don’t always maintain their solid structure once inside the body. MIT chemical engineers have now designed an injectable gel that responds to the body’s high temperature by forming a reinforcing network that makes the gel much more durable, allowing it to function over a longer period of time. The research team, led by Bradley Olsen, an assistant professor of chemical engineering, described the new gels in a recent issue of the journal Advanced Functional Materials. Lead author of the paper is Matthew Glassman, a graduate student in Olsen’s lab. Jacqueline Chan, a former visiting student at MIT, is also an author. Olsen and his students worked with a family of gels known as shear thinning hydrogels, which have a unique ability to switch between solid-like and liquid-like states. When exposed to mechanical stress – such as being pushed through an injection needle – these gels flow like fluid. But once inside the body, the gels return to their normal solid-like state. However, a drawback of these materials is that after they are injected into the body, they are still vulnerable to mechanical stresses. If such stresses make them undergo the transition to a liquid-like state again, they can fall apart. “Shear thinning is inherently not durable,” Olsen says. “How do you undergo a transition from not durable, which is required to be injected, to very durable, which is required for a long, useful implant life?” The MIT team answered that question by creating a reinforcing network within their gels that is activated only when the gel is heated to body temperature (37 degrees Celsius).

New injectable gels toughen up after entering the body (11/18/2012)

Posted: November 2, 2012 by Wildcat in Uncategorized
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Donating your body to science is a well known but poorly understood concept. Today being Halloween, you can expect a lot of visual demonstrations around of what could happen to someone’s body after death, were myths and legends of the occult all real things. They could be those who have ‘ignored’ bodily death like vampires or mummies, those who have died but their bodies have been reanimated like zombies or Frankenstein’s monster, or those like ghosts who have lost their body altogether but seem to be unaware of this fact. But Halloween is a bit of harmless fun for one night of the year. For the rest of the time, if you want to posthumously do something with your body, there’s always science. Donating your body to science is a concept most people are familiar with but few know how to go about. In fairness, those who do end up leaving their body to science don’t talk about it afterwards, so the process isn’t something that’s become common knowledge. It’s not a matter of having your carcass dropped off at the nearest laboratory; there are a lot of legal matters to attend to. But even if there weren’t, there’s not much a typical lab can actually do with a human body, not unless they urgently need a cumbersome and extremely morbid paperweight. (via Donating your body to science: a beginner’s guide | Dean Burnett | Science |

Posted: October 25, 2012 by Wildcat in Uncategorized
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If human beings had not invented cooking as a way of increasing the number of calories they consumed, they could only have supported the 86bn neurons in their big brains by spending an impossible nine hours or more each day eating raw food, according to a scientific paper published on Monday. The research, the authors suggest, explains why great apes such as gorillas, which can have bodies three times the size of humans, have considerably smaller brains. Though gorillas typically spend up to eight hours feeding, their diet influenced an evolutionary tradeoff between body and brain size; supporting both big bodies and big brains would be impossible on a raw food diet. The brain is so energy-hungry that in humans it represents 20% of the resting metabolic rate, even though it only represents 2% of body mass, suggest Professor Suzana Herculano-Houzel and Karina Fonseca-Azevedo of the Institute of Biomedical Sciences at the Federal University of Rio de Janeiro. “Why are the largest primates not those endowed with the largest brains as well? Rather than evidence that humans are an exception among primates, we consider this disparity to be a clue that, in primate evolution, developing a very large body and a very large brain have been mutually excluding strategies, probably because of metabolic reasons.” (via Invention of cooking made having a bigger brain an asset for humans | Science | The Guardian)

Posted: October 10, 2012 by Wildcat in Uncategorized
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Most people appreciate electronics that are durable and can last for years before needing to be replaced. If the device in question is a medical implant or a sensor for monitoring environmental conditions, however, designers might prefer the gadget to simply biodegrade without a trace once its purpose is fulfilled. University of Illinois researchers, working with colleagues at Tufts University and Northwestern University, report in the September 28 issue of Science having developed a way to make “transient” electronics able to do just that by dissolving in small amounts of bodily fluid. Other triggers for dissolution and absorption by the body might someday include heat, radiation and pH levels. (via Electronic Sensors That Dissolve Could Keep Tabs on the Body from the Inside [Video] | Observations, Scientific American Blog Network)

Posted: September 22, 2012 by Wildcat in Uncategorized
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Muscles that burn energy without contracting have yielded new clues about how the body retains a constant temperature – and they may provide new targets for combating obesity. Traditionally, the body’s main thermostat was thought to be brown fat. It raids the body’s white fat stores in cold conditions to burn energy and keep the body warm. Muscles also play a role in keeping the body warm by contracting and triggering the shiver response – but this is only a short-term fix because prolonged shivering damages muscles. Now it seems that muscles have another way to turn up the heat. “Our findings demonstrate for the first time that muscle, which accounts for 40 per cent of body weight in humans, can generate heat independent of shivering,” says Muthu Periasamy of Ohio State University in Columbus. (via Muscles that do nothing can keep you warm and thin – health – 09 September 2012 – New Scientist)

Posted: July 29, 2012 by Wildcat in Uncategorized
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What produces 300 times more heat than any other organ in the body? What stops a baby from freezing to death if left in the cold? The answer to both questions is “brown fat”. Scientists have discovered that this type of fat is a good thing because it produces lots of heat by burning calories. Unlike white fat, which clings to our hips and expands our ageing waistlines, brown fat keeps the weight off. And that’s why the race is on to find out more about brown adipose tissue, also known as brown fat, and how humans could use it to our advantage. When we’re born we have lots of brown fat in our bodies, wrapped round the central organs to keep us warm, to help us adapt to life outside the womb. As we grow, however, the brown fat content of our bodies decreases. Researchers at the University of Nottingham have been using heat-seeking technology to find out if brown fat is still present in children and adults. (via BBC News – Why brown fat is ‘good’ in the fight against obesity)

Posted: July 15, 2012 by Wildcat in Uncategorized
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Though often referred to as the “trust hormone” oxytocin is increasingly being seen as a brain chemical that does a lot more than just bring couples closer together. New research is suggesting that oxytocin plays a crucial part in enabling us to not just forge and strengthen our social relations, but in helping us to stave off a number of psychological and physiological problems as well. But more conceptually, oxytocin is proving to be a crucial ingredient to what makes us human. Here are ten reasons why oxytocin is simply the most incredible molecule on the planet: (via 10 Reasons Why Oxytocin Is The Most Amazing Molecule In The World)