In today's edition:
- New discovery may enhance MRI scans, lead to portable MRI machines
- Light-wave implant hope for deaf
- Under construction: The fuel tank of the future
- New 'barcode chip' allows cheap, fast blood tests
- Nanotech clothing fabric 'never gets wet'
New discovery may enhance MRI scans, lead to portable MRI machines
COLLEGE PARK, MD, Nov. 25, 2008 -- Researchers in Ohio and France have solved a longstanding scientific mystery involving magnetic resonance -- the physical phenomenon that allows MRI instruments in modern hospitals to image tissues deep within the human body. Their discovery, a new mathematical algorithm, should lead to new MRI techniques with more informative and sharper images.
As described in an article posted online today in the Journal of Chemical Physics, the work may even help scientists devise ways of using MRI without having to put people inside giant magnets -- an advance that could lead to portable and less costly MRIs.
The new work solves a mystery that has persisted for decades, says Philip Grandinetti, a professor of chemistry at The Ohio State University and one of the coauthors of the article. The solution to this mystery came as a result of their work in trying to optimize magnetic resonance pulse sequences. Specifically, they were looking for better ways of doing something known as an "inversion" in a magnetic resonance measurement.
Bathed in the magnetic field, atomic nuclei within water and other molecules throughout cells and tissues in a person's body will align themselves in the direction of the magnetic field. Inversion is an important process done in MRI scans that realigns the nuclei so they are against the magnetic field. When all is said and done, inverting the nuclei of people inside MRI scanners can reveal such things as cancer tumors, whose slightly different response to the changing field can be used to detect their presence amid surrounding healthy tissue.
These inversions of the nuclear spins are typically done "adiabatically". The method involves placing a patient inside the large donut-shaped magnet of an MRI instrument and applying low-power radio waves that sweep through a specific range of frequencies. If a frequency sweep is performed slowly enough then at the end of the process all the nuclei will be "inverted."
The question is why this worked. The new work describes it in terms of a new mathematical framework, called "superadiabaticity" that was discovered in the late 1980s by Michael Berry, a mathematical physicist at University of Bristol, but largely unappreciated until now. This can help them design ways to better control MRI inversions and get more information out of MRI scans.
Grandinetti hopes to incorporate the algorithm into software for controlling MRI scans, where it would boost image resolution. One day, it might even help these instruments obtain signals from objects located outside of a magnet. source
because it was too inefficient for tMy comment: Why this is important? Because MRI was generally not used in work with brainhe small regions of the brain it was supposed to image as well as their dynamics. It's not impossible, but it didn't show such a good results so far. And now, we see a new method, that can boost the power of MRI-imagine what this could for head/computer connection! Especially since we're in magnetic fields all the time. That could be VERY useful.
Light-wave implant hope for deaf
Nerves in the ear can be stimulated by light as well as sound and the team from Northwestern University, Illinois, is aiming to harness this.
Infrared light shone onto guinea pig nerve cells produced better results than standard cochlear implants, a report in New Scientist magazine said.
But UK charity RNID said a device for human use might take years to develop.
The system works by placing approximately 20 electrodes to directly stimulate the nerves in the inner ear, but it has its limitations, with users finding it hard to appreciate music or communicate in a noisy environment.
This is because there are as many as 3,000 "hair cells" in a healthy ear, contributing to a far more detailed interpretation of sound than the implant can provide.
Dr Claus-Peter Richter from Northwestern believes that an effect discovered by chance could hold the key to a better implant.
Surgeons who used lasers to perform a surgical procedure in the ear discovered that they were able to stimulate the nerve cells there to send an electrical message back to the brain.
Exactly why this happens is unclear, although Dr Richter believes that the heat that accompanies the light may be responsible. However, the narrow beam possible using light rather than an electrode offers the possibility of a far more precise targeting of these neurons.
He shone infrared light into the neurons of deaf guinea pigs, while measuring electrical activity in a nerve "relay" between the inner ear and the brain. The frequency "maps" produced this way are a good indication of the quality of information reaching the brain.
While the "maps" produced by cochlear implants were less detailed, those produced after infrared stimulation were as sharp as those produced by sound in hearing guinea pigs.
Dr Richter is now working on ways to produce fibre optic devices which could target light within the inner ear. source
Under construction: The fuel tank of the future
- 24 November 2008
If the hydrogen economy is ever going to become reality, we will need a way to store the stuff without having to compress it to dangerously high pressures.
Such a technique may now be coming together in a Dutch lab, in the shape of a material in which billions of carbon buckyballs are sandwiched between sheets of graphene - another form of carbon.
The US Department of Energy reckons that to be viable, hydrogen stores should hold at least 6 per cent by weight of the gas. Until now, materials designed to do the job have fallen well short of this target-up to 2% for metal hydrides.
Last month, George Froudakis and his team at the University of Crete in Greece reported that computer simulations of a layer cake of graphene sheets connected by hollow carbon nanotubes (see right) indicate that it could store 6.1 per cent of its weight in hydrogen (Nano Letters, vol 8, p 3166).
Now Dimitrios Gournis of the University of Groningen in the Netherlands has started to make this exotic sandwich. So far he has created a 40-layer structure in which the sheets are separated by buckyballs, and is aiming to replace these with the nanotubes envisaged by Froudakis by the end of the year. The next step will be to fill the structures with hydrogen to see whether Froudakis's predictions hold true. source
My comment: That's more futuristic than realistic, but I figured it's interesting. However, I think that until we see the storage created in physical reality, it's still simply a good calculation.
New 'barcode chip' allows cheap, fast blood testsA new "barcode chip" developed by researchers at the California Institute of Technology (Caltech) promises to revolutionize diagnostic medical testing. In less than 10 minutes, and using just a pinprick's worth of blood, the chip can measure the concentrations of dozens of proteins, including those that herald the presence of diseases like cancer and heart disease.
An IBBC, described in a paper in the advance online edition of Nature Biotechnology, is about the size of a microscope slide and is made out of a glass substrate covered with silicone rubber. The chip's surface is molded to contain a microfluidics circuit--a system of microscopic channels through which the pinprick of blood is introduced, protein-rich blood plasma is separated from whole blood, and a panel of protein biomarkers is measured from the plasma.
The chip offers a significant improvement over the cost and speed (10 minutes) of standard laboratory tests to analyze proteins in the blood.
A single chip can simultaneously test the blood from eight patients, and each test measures many proteins at once. The researchers reported on devices that could measure a dozen proteins from a fingerprick of blood, and their current assays are designed for significantly more proteins. "We are aiming to measure 100 proteins per fingerprick within a year or so. It's a pretty enabling technology," Heath says.
In the Nature Biotechnology paper, the researchers tested the chip on the concentration of human chorionic gonadotropin (hCG), the hormone produced during pregnancy. The scientists also used the barcode chip to analyze the blood of breast and prostate cancer patients for a number of proteins that serve as biomarkers for disease.
The barcode chip is now being tested in human clinical trials on patients with glioblastoma, a common and aggressive form of brain tumor. The researchers are also using the chips in studies of healthy individuals, to determine how diet and exercise change the composition of the proteins in the blood.
Currently, the barcoded information is "read" with a common laboratory scanner that is also used for gene and protein expression studies. "But it should be very easy to design something like a supermarket UPC scanner to read the information," making the process even more user-friendly, says Fan, the first author on the paper. source
My comment:Ok, that's certainly very very cool. Imagine astronauts taking samples of alien world and checking them on a mini-device resembling of a phone. Or even better- a phone with which you can check your particular state of the blood- like the level of sugars-and eat what is appropriate for the case, not just anything. That is ony of the keys for health if you think about it. I can only hope it gets commercial!
Nanotech clothing fabric 'never gets wet'
- 18:02 24 November 2008 by Jon Evans
Lead researcher Stefan Seeger at the University of Zurich says the fabric, made from polyester fibres coated with millions of tiny silicone filaments, is the most water-repellent clothing-appropriate material ever created.
Drops of water stay as spherical balls on top of the fabric and a sheet of the material need only be tilted by 2 degrees from horizontal for them to roll off like marbles. A jet of water bounces off the fabric without leaving a trace .
The secret to this incredible water resistance is the layer of silicone nanofilaments, which are highly chemically hydrophobic. The spiky structure of the 40-nanometre-wide filaments strengthens that effect, to create a coating that prevents water droplets from soaking through the coating to the polyester fibres underneath.
A similar combination of water-repelling substances and tiny nanostructures is responsible for many natural examples of extreme water resistance, such as the surface of Lotus leaves.
The silicone nanofilaments also trap a layer of air between them, to create a permanent air layer. Similar layers - known as plastrons - are used by some insects and spiders to breathe underwater.
This fine layer of air ensures that water never comes into contact with the polyester fabric. It can be submerged in water for two months and still remain dry to the touch, says Seeger.
The coating can be added to other textiles, thoug polyester currently gives the best results. It is also durable, but not to a washing machine cycle. source
My comment:Ain't that awesome? Ok, for me it is. I love water, but only when I'm close to home. And this is just the divers heaven-you can get into water and don't soak and don't get cold, probably. Though it doesn't mention the heat-insulation properties. In any case, it sounds very promising.