Showing posts with label science. Show all posts
Showing posts with label science. Show all posts

Sunday, December 2, 2012

Laser-powered 'needle' promises pain-free injections

Laser-powered 'needle' promises pain-free injections



ScienceDaily (Sep. 13, 2012) — From annual flu shots to childhood immunizations, needle injections are among the least popular staples of medical care. Though various techniques have been developed in hopes of taking the "ouch" out of injections, hypodermic needles are still the first choice for ease-of-use, precision, and control.
A new laser-based system, however, that blasts microscopic jets of drugs into the skin could soon make getting a shot as painless as being hit with a puff of air.
The system uses an erbium-doped yttrium aluminum garnet, or Er:YAG, laser to propel a tiny, precise stream of medicine with just the right amount of force. This type of laser is commonly used by dermatologists, "particularly for facial esthetic treatments," says Jack Yoh, professor of mechanical and aerospace engineering at Seoul National University in South Korea, who developed the device along with his graduate students. Yoh and his team describe the injector in a paper published today in the Optical Society's (OSA) journal Optics Letters.
The laser is combined with a small adaptor that contains the drug to be delivered, in liquid form, plus a chamber containing water that acts as a "driving" fluid. A flexible membrane separates these two liquids.Each laser pulse, which lasts just 250 millionths of a second, generates a vapor bubble inside the driving fluid. The pressure of that bubble puts elastic strain on the membrane, causing the drug to be forcefully ejected from a miniature nozzle in a narrow jet a mere 150 millionths of a meter (micrometers) in diameter, just a little larger than the width of a human hair.
"The impacting jet pressure is higher than the skin tensile strength and thus causes the jet to smoothly penetrate into the targeted depth underneath the skin, without any splashback of the drug," Yoh says. Tests on guinea pig skin show that the drug-laden jet can penetrate up to several millimeters beneath the skin surface, with no damage to the tissue. Because of the narrowness and quickness of the jet, it should cause little or no pain, Yoh says. "However, our aim is the epidermal layer," which is located closer to the skin surface, at a depth of only about 500 micrometers. This region of the skin has no nerve endings, so the method "will be completely pain-free," he says.
In previous studies, the researchers used a laser wavelength that was not well absorbed by the water of the driving liquid, causing the formation of tiny shock waves that dissipated energy and hampered the formation of the vapor bubble. In the new work, Yoh and colleagues use a laser with a wavelength of 2,940 nanometers, which is readily absorbed by water. This allows the formation of a larger and more stable vapor bubble "which then induces higher pressure on the membrane," he explains. "This is ideal for creating the jet and significantly improves skin penetration."
Although other research groups have developed similar injectors, "they are mechanically driven," using piston-like devices to force drugs into the skin, which gives less control over the jet strength and the drug dosage, Yoh says. "The laser-driven microjet injector can precisely control dose and the depth of drug penetration underneath the skin. Control via laser power is the major advancement over other devices, I believe."
Yoh is now working with a company to produce low-cost replaceable injectors for clinical use. "In the immediate future, this technology could be most easily adopted to situations where small doses of drugs are injected at multiple sites," he says. "Further work would be necessary to adopt it for scenarios like mass vaccine injections for children."

Tuesday, August 7, 2012

Is Death An Illusion? Biocentrism

via Just thought it was interesting.  There's also a book on this.


After the death of his old friend, Albert Einstein said “Now Besso has departed from this strange world a little ahead of me. That means nothing. People like us … know that the distinction between past, present and future is only a stubbornly persistent illusion.”
New evidence continues to suggest that Einstein was right – death is an illusion.
Our classical way of thinking is based on the belief that the world has an objective observer-independent existence. But a long list of experiments shows just the opposite. We think life is just the activity of carbon and an admixture of molecules – we live awhile and then rot into the ground.
We believe in death because we’ve been taught we die. Also, of course, because we associate ourselves with our body and we know bodies die. End of story. But biocentrism – a new theory of everything – tells us death may not be the terminal event we think. Amazingly, if you add life and consciousness to the equation, you can explain some of the biggest puzzles of science. For instance, it becomes clear why space and time – and even the properties of matter itself – depend on the observer. It also becomes clear why the laws, forces, and constants of the universe appear to be exquisitely fine-tuned for the existence of life.
Until we recognize the universe in our heads, attempts to understand reality will remain a road to nowhere.
Consider the weather ‘outside’: You see a blue sky, but the cells in your brain could be changed so the sky looks green or red. In fact, with a little genetic engineering we could probably make everything that is red vibrate or make a noise, or even make you want to have sex like with some birds. You think its bright out, but your brain circuits could be changed so it looks dark out. You think it feels hot and humid, but to a tropical frog it would feel cold and dry. This logic applies to virtually everything. Bottom line: What you see could not be present without your consciousness.
In truth, you can’t see anything through the bone that surrounds your brain. Your eyes are not portals to the world. Everything you see and experience right now – even your body – is a whirl of information occurring in your mind. According to biocentrism, space and time aren’t the hard, cold objects we think. Wave your hand through the air – if you take everything away, what’s left? Nothing. The same thing applies for time. Space and time are simply the tools for putting everything together.
Consider the famous two-slit experiment. When scientists watch a particle pass through two slits in a barrier, the particle behaves like a bullet and goes through one slit or the other. But if you don’t watch, it acts like a wave and can go through both slits at the same time. So how can a particle change its behavior depending on whether you watch it or not? The answer is simple – reality is a process that involves your consciousness.
Or consider Heisenberg’s famous uncertainty principle. If there is really a world out there with particles just bouncing around, then we should be able to measure all their properties. But you can’t. For instance, a particle’s exact location and momentum can’t be known at the same time. So why should it matter to a particle what you decide to measure? And how can pairs of entangled particles be instantaneously connected on opposite sides of the galaxy as if space and time don’t exist? Again, the answer is simple: because they’re not just ‘out there’ – space and time are simply tools of our mind.
Death doesn’t exist in a timeless, spaceless world. Immortality doesn’t mean a perpetual existence in time, but resides outside of time altogether.
Our linear way of thinking about time is also inconsistent with another series of recent experiments. In 2002, scientists showed that particles of light “photons” knew – in advance – what their distant twins would do in the future. They tested the communication between pairs of photons. They let one photon finish its journey – it had to decide whether to be either a wave or a particle. Researchers stretched the distance the other photon took to reach its own detector. However, they could add a scrambler to prevent it from collapsing into a particle. Somehow, the first particle knew what the researcher was going to do before it happened – and across distances instantaneously as if there were no space or time between them. They decide not to become particles before their twin even encounters the scrambler. It doesn’t matter how we set up the experiment. Our mind and its knowledge is the only thing that determines how they behave. Experiments consistently confirm these observer-dependent effects.
Bizarre? Consider another experiment that was recently published in the prestigious scientific journal Science (Jacques et al, 315, 966, 2007). Scientists in France shot photons into an apparatus, and showed that what they did could retroactively change something that had already happened in the past. As the photons passed a fork in the apparatus, they had to decide whether to behave like particles or waves when they hit a beam splitter. Later on – well after the photons passed the fork – the experimenter could randomly switch a second beam splitter on and off. It turns out that what the observer decided at that point, determined what the particle actually did at the fork in the past. At that moment, the experimenter chose his past.
Of course, we live in the same world. But critics claim this behavior is limited to the microscopic world. But this ‘two-world’ view (that is, one set of physical laws for small objects, and another for the rest of the universe including us) has no basis in reason and is being challenged in laboratories around the world. A couple years ago, researchers published a paper inNature (Jost et al, 459, 683, 2009) showing that quantum behavior extends into the everyday realm. Pairs of vibrating ions were coaxed to entangle so their physical properties remained bound together when separated by large distances (“spooky action at a distance,” as Einstein put it). Other experiments with huge molecules called ‘Buckyballs’ also show that quantum reality extends beyond the microscopic world. And in 2005, KHC03 crystals exhibited entanglement ridges one-half inch high, quantum behavior nudging into the ordinary world of human-scale objects.
We generally reject the multiple universes of Star Trek as fiction, but it turns out there is more than a morsel of scientific truth to this popular genre. One well-known aspect of quantum physics is that observations can’t be predicted absolutely. Instead, there is a range of possible observations each with a different probability. One mainstream explanation, the “many-worlds” interpretation, states that each of these possible observations corresponds to a different universe (the ‘multiverse’). There are an infinite number of universes and everything that could possibly happen occurs in some universe. Death does not exist in any real sense in these scenarios. All possible universes exist simultaneously, regardless of what happens in any of them.
Life is an adventure that transcends our ordinary linear way of thinking. When we die, we do so not in the random billiard-ball-matrix but in the inescapable-life-matrix. Life has a non-linear dimensionality – it’s like a perennial flower that returns to bloom in the multiverse.
“The influences of the senses,” said Ralph Waldo Emerson “has in most men overpowered the mind to the degree that the walls of space and time have come to look solid, real and insurmountable; and to speak with levity of these limits in the world is the sign of insanity.”

Wednesday, May 2, 2012

This Too Shall Pass

This music video definitely required patience, skill, and intelligence. Music video by OK GO. Just...wow.


Sunday, April 29, 2012

Realistic ECT

A TED video about electro-compulsive therapy from someone who has undergone treatment. Since I have a mental illness, I want to share this.


Thursday, April 26, 2012

A Journey to Saturn

Saturn is my favorite planet. The video starts off a bit dry, but gets better. It gives you a new perspective of our place in the universe. There's also geology in it! Yes, another TED video.


Monday, April 23, 2012

How Well Do You Know Earth?

The largest waterfall is in the ocean. Vampire squids exist. There's fire deep in the sea. The ocean controls the climate, our water supply, the air we breathe, yet we've only explored 5% of it. Another TED lecture found here.