Wednesday, April 20, 2011

Researchers "Grow" New Blood Vessels



Synthetic blood vessels that can be made in advance and stored until surgery could help patients undergoing heart surgery, hemodialysis—cleansing of the blood in cases of kidney failure—and other procedures. Laura Niklason, an anesthesiologist and biomedical engineer at Yale University, and her collaborators have grown blood vessels using human cells and tested them in baboons, showing that they provoke no immune rejection and avoid common complications of synthetic vessels, such as clotting, bursting, or contracting over time. Researchers hope these studies will show that the vessels are safe enough to win permission from the U.S. Food and Drug Administration to begin clinical trials.

During bypass surgery, doctors looking to circumvent blocked arteries usually harvest vessels from a patient's leg or arm. But people who suffer from vascular disease or who have had previous procedures may have no suitable vessels left. The other options have complications: grafts from donors are often rejected by the recipient's immune system, artificial plastic vessels have high rates of blood clots and other problems, and vessels grown from a patient's own tissue take more than six months to mature. "Artificial grafts suffer from clotting and obstruction because they are not tissue," says Niklason, especially when plastic is used.
Niklason says she has solved this problem by creating vessels that are derived from living tissue but can be used off-the-shelf and are not rejected by the immune system. Using a technique she developed at MIT in the 1990s, researchers seed tubular scaffolds with smooth muscle cells. The cells secrete collagen and other connective tissue molecules around the scaffolds, forming blood vessels. After the scaffolds break down, the vessels are washed with a detergent that strips away the cells, leaving behind the fibrous tubes of collagen.


Because the tubes contain no living cells, they do not trigger an immune response and have a shelf life of more than a year. The group has previously grown vessels using cells from several different animal species, including canine versions for heart bypass surgeries in dogs.


Now, in a report published in Science Translational Medicine, the researchers have grown vessels using human cells for the first time. They used the vessels to link an artery and a vein in baboons, creating a structure called a fistula to mimic the setup required by hemodialysis patients, who have a needle injected into such a link two or three times a week to get their blood filtered. Also, while previous versions of the vessels required a wait of several weeks while the insides of the vessels were "personalized" with some of the patient's own cells, a process that makes them less likely to clog, these hemodialysis vessels did not need that treatment.
"That means they could potentially be immediately available to the patient," says Shannon Dahl, a biomedical engineer who cofounded a biotechnology company called Humacyte with Niklason and another colleague to help bring the technology to market. Humacyte initially plans to test its technology in hemodialysis patients, though Dahl declined to give a timeline for clinical trials.

Researchers ultimately hope to test the vessels for heart surgeries, but they first want to show that the technology is safe and effective. "I would love to get to coronary bypass at some point, but we have to prove that this is a good, safe therapy in other anatomical locations first," says Niklason. A hemodialysis graft is much more easily replaced than a bypass graft if there are infections or other problems.
The researchers' use of baboons also provides important additional support before they move into human trials, says David Putnam, a chemical engineer at Cornell University who studies biomaterials. The reason is that the dynamics of blood flow in baboons are a good model for what happens in humans, he says. "They are going about this very well, very carefully. They're building a house with very strong bricks," he says. "And the next step is humans."

Insulin Pill Against Diabetes Undergoes Testing


One of the most cumbersome and inconvenient aspects of diabetes is the fact that patients suffering from advanced forms need to inject insulin into their bloodstream each day. Their own body is unable to produce the hormone, and they cannot survive without it. Delivering insulin has become big business, and many research groups have been looking for a method of making the entire process simpler and more efficient. Now, the Denmark-based Novo Nordisk has been found to engage in phase 1 clinical testings of a new pill, which may deliver insulin without the need for painful shots.

The pharmaceutical corporation has been a leader in the field of diabetes care for most of its 87-year history, delivering numerous products and therapies to sufferers. The new effort, if successful, would additionally consolidate its position, while at the same time providing diabetes patients with the Holy Grail of all cures, the insulin pill. Encapsulating the hormone in an easy-to-swallow dose is not exactly a walk in the park, but the fact that Novo is so advanced in its research can only mean excellent news for the company and patients alike, Technology Review reports. 

In addition to the added comfort associated with receiving insulin in this manner, the pill would also entail other, more important benefits. If ingested, it reaches the stomach directly, from where it can easily go to the liver, mimicking the action of its naturally-produced counterpart. Generally, diabetes sufferers who have daily injections tend to insert the hormone in muscles or fat, which means that the substance is fairly far away from where it needs to go. This is why even patients who take their insulin shots at the correct time of day can develop hypoglycemia at any given point. 

There are several hurdles associated with delivering insulin orally. They include the highly-acidic nature of gastric liquids, the complex nature of the insulin molecules, the rate at which epithelial cells absorb the compound and so on. In order to circumvent most of these problems, the Novo team turned to protein engineering, so as to modify insulin according to needs. “You can't use human insulin [for developing orally-delivered pills]. ]It doesn't work,” explains Novo's chief scientific officer, Mads Krogsgaard Thomsen. The team is currently still tweaking its final product, details of which are currently kept under wraps.

Learning and Memory Enhancer Was Discovered


A team of medical researchers from the University of Bristol have found the explanation for the interaction between brain state and the neural triggers responsible for learning.

This discovery
 could open the way to new methods of strengthening cognitive functions in people suffering from debilitating diseases like Alzheimer’s, but also help improve memory in healthy individuals.

What makes this finding really exciting is the fact that the researchers from Bristol’s School of Physiology and Pharmacology, were able to study, in isolation, the exact neurotransmitter that enhances learning and memory – acetylcholine.
They studied the effects that drugs targeting acetylcholine receptors and SK channels have on the force of the connections between nerve cells in animal brain tissue. 

They found out that administrating drugs that activate acetylcholine receptors or block SK channels, made changing the connection strength much easier, thus establishing a link between the two proteins.

Lead researcher Dr Jack Mellor, from the University of Bristol’s Medical School said that “from a therapeutic point of view, this study suggests that certain drugs that act on specific acetylcholine receptors may be highly attractive as potential treatments for cognitive disorders. 

“Currently, the only effective treatments for patients with Alzheimer’s disease are drugs that boost the effectiveness of naturally released acetylcholine. 

“We have shown that mimicking the effect of acetylcholine at specific receptors facilitates changes in the strength of connections between nerve cells. 

“This could potentially be beneficial for patients suffering from Alzheimer’s disease or schizophrenia.”

During learning, acetylcholine is released in the brain where it boosts the capacity of acquiring new memories, by facilitating the activity of the NMDA receptors – proteins in charge of the strength of the connections between nerve cells, within the brain.

The researchers have shown that acetylcholine facilitates NMDA receptors by inhibiting other proteins called SK channels, which normally restrict NMDA receptors' activity.

They do so by preventing changes in the strength of nerve cells connections, weakening the brain's ability to encode memories.

Releasing acetylcholine removes the SK barrier, and enhances the brain’s capacity of learning and remembering information. 

Still, Dr Mellor said that “these findings are not going to revolutionize the treatment of Alzheimer’s disease or other forms of cognitive impairment overnight.

“However, national and international funding bodies have recently made research into aging and dementia a top priority so we expect many more advances in our understanding of the mechanisms underlying learning and memory in both health and disease.”

The researchers were affiliated to the 
University of Bristol’s MRC Center for Synaptic Plasticity and the Division of Neuroscience in the School of Physiology & Pharmacology, part of the Bristol Neuroscience network, and their work was supported by the Wellcome Trust, MRC, BBSRC and GSK.

The results are described in the journal Neuron.

Learning and Filing Information in Your Sleep


During sleep, your brain can learn a new piece of information and even store it for later, so that it pops up when you need it, found a new study carried out by researchers at theUniversity of York and Harvard Medical School.

The team also discovered that sleep helps people remember new words easier and allows them to enrich their 'mental lexicon' with new vocabulary.

For the experiments, the study volunteers learned new words in the evening and were tested right afterward.
They slept over night at the lab while their brain activity was recorded using an electroencephalogram, and the next morning underwent another test.

The results proved that the subjects could remember more words than they did just after they had learned them, and they could also recognize them faster, which supports the theory that sleep has strengthened the new memories. 

For the control group however, things went a little differently: they were trained in the morning and were re-tested in the evening, without getting any sleep in between, and their results were much weaker.

The researchers examined the brainwaves of sleep volunteers and saw that deep sleep or slow-wave sleep, helped more in strengthening new memories, than REM sleep (light sleep) did.

Another thing that the researchers tested was whether the new words had been integrated with already existing knowledge in the mental lexicon, and doing so, they discovered the importance of sleep spindles in the brain.

Sleep spindles are short but very intense bursts of brain activity which occur during the information transfer between the hippocampus and the neocortex (hippocampus memories are stored away from other memories, and the neocortex memories are connected to existing knowledge).

Participants who had more sleep spindles during the night made better connections between the new words and the others in their mental lexicon.

“We suspected from previous work that sleep had a role to play in the reorganization of new memories, but this is the first time we've really been able to observe it in action, and understand the importance of spindle activity in the process,” said co-author of the paper, Professor Gareth Gaskell, of the University of York's Department of Psychology.

These results are another confirmation of the importance of sleep in learning new things.

The study was funded by the Economic and Social Research Council and was published in the Journal of Neuroscience.

Monday, April 18, 2011

Bike Concept Turns Into Cart



Green types that like to ride their bike to buy groceries rather than having to drive to the store, but worry that their bike will get stolen will get a kick out of the Urban Folding Bicycle concept. The concept was designed by Hyuk-Jae Chang and won a bronze prize at the IDEA Design Awards 2010.
The basic concept is a normalish looking bike that you can ride around town with a chain and disc brakes. Once you get to the store rather than chain your bike to a post or bike rack, you simply fold it down into your own shopping card.

The cart has a push handle and a pair of baskets for your purchases. Once back outside you unfold the bike again and ride away. The only downside I see is that the baskets are a bit small. You won’t be buying many groceries at once.

Sony Laser Enables 1TB Optical Disks


It was just a short while ago that Sharp announced its first BDXL Blu-ray disks, with a capacity of 100GB and, soon after, TDK revealed its own plans to join this movement. Later, once the first batch of disks starts selling, the two hope to move on to 128GB disks. Needless to say, these capacities are nothing to be frowned upon, but they may not keep their title as greatest for as long as some might think. Sony, in partnership with Tohoku University of Japan, have apparently developed a laser that has a watt output 100 times higher than the currently highest values for conventional blue-violet pulse semiconductor lasers.

Basically, the new type of laser has an output of 100 watts and supposedly has the ability to scribe up to 20 times more data on a disk, compared to 'regular' Blu-ray. Essentially, this equals about 1TB. Granted, this technology isn't exactly in line with the vision of a future completely free of the need for optical storage, but a technology like this is still a great step forward. Unfortunately, there was absolutely no mention of how long it will take for it to see practical implementations.

“This latest successful development is an all-semiconductor laser picosecond pulse source with a laser wavelength of 405 nanometers (1 nm = one-billionth of a meter) in the blue-violet region,” the Sony/Tohoku University press releasereportedly states. “It is capable of generating optical pulses in the ultrafast duration of 3 picoseconds (1 picosecond = one-trillionth of a second), with ultrahigh output peak power of 100 watts and repetition frequency of 1 gigahertz. Advanced control of the newly-developed and proprietarily-constructed GaN-based mode-locked semiconductor laser and semiconductor optical amplifier have enabled peak output power in excess of 100 watts to be achieved, which is more than a hundred times the world’s highest output value for conventional blue-violet pulse semiconductor lasers.”

“There are high expectations that this newly-developed semiconductor laser system, which incorporates semiconductor diodes, will be able to be used in a much wider range of applications in the future thanks to technology such as this, which enables the size of devices such as the light source box to be drastically reduced,” they added.

Postage Stamp-Sized SSDs Coming in 2012


End-users are most likely more than aware of the fact that solid state drives are still a way off from becoming mainstream, even though they have significantly higher data-transfer rates when compared to hard drives. This lower popularity is mostly due to the fact that hard disks have larger storage capabilities and are a more mature technology than that of SSDs. Still, SSDs have steadily been filling the gap and it seems that this gap might disappear altogether in the not-so-distant future, if the work of a team of Japanese researchers is anything to go by.

Led by Professor Tadahiro Kuroda, the group created a prototype of a postage stamp-sized SSD.

The Nikkei reports that the research team claims to have put together a technology that allows solid state drives to shrink considerably. The storage unit will supposedly be 90% smaller than current solutions. This would already be noteworthy, but the device will also, supposedly, be able to pack even 1TB of space in this stamp-sized form factor. Not only that, but the storage device will also see an added energy efficiency, namely of 70%. 

The research team is made up of people from Toshiba and the Keio University of Tokyo. Under the guidance of Professor Tadahiro Kuroda, they were able to create the aforementioned prototype with 128 NAND flash memory chips and a controller chip. The unit is able to achieve a transfer speed of up to 2Gbps and, the team says, is based on radio communications. According to them, radio communication will ultimately lower the production cost of such SSDs. This means that, in addition to being capacious (1TB) and efficient, the new solid state drives will also be cheaper than competing HDDs. 

Unfortunately, even though the researchers were able to patch together a working prototype, it seems that such a product won't become available in the very near future. The team expects the first such device to only come out during 2012.

Hitachi Surprises with 7mm 7200RPM 320GB HDD



There are many ways that a new storage solution can cause jaws to be inadvertently dropped. Usually, it is because the read and/or write speed is spectacular, or because some new feature or another is supported. Other times, a device would stand out through being the first of its kind, as it happened with the first SSDs and, later, with the first PCI Express solid state drives. It appears, however, that there might be another way of turning heads.


Toshiba has combined inventiveness with experience in order to come up with a hard disk drive that stands out through being smaller than all of its peers. To be more specific, the SATA 3.0Gbps Travelstar Z7K320 that the hardware maker presented today, though it uses the same 2.5-inch form factor that all compact HDDs come with, is much thinner than one would expect. In fact, it is so thin that it will probably make its way into most ultrathin laptops slated for release during the later parts of 2010.

The actual thickness if of 7 millimeters, a full 2.5mm less than standard units (9.5mm). The performance, on the other hand, doesn't seem to have suffered the same shrinkage effect. The platter still manages to maintain a rotary speed of 7,200RPM (rotations per minute) and, backed by 16MB cache, the maximum transfer rate still gets as high as 1,334Mbps. This is quite significant, especially considering the power draw (1.8 Watts during read/write and 0.8 watts during standby).

As for noise hazards, the humming produced by the storage solution shouldn't go over 23dB when idle and 24dB when seeking. August is the earliest one can expect to see this product, as well a 5,400RPM version, being mass produced, which means that super-thin notebooks will start to show up soon after.

“As a leading personal computing company, we are constantly evaluating and offering new designs and technologies that make computing more enjoyable and affordable for our customers," said Wentao Yang, vice president, Global Procurement, Lenovo Group. "Hitachi's 7mm product family represents important advancements for the industry. We look forward to continuing our relationship with Hitachi and working together to innovate and take the computing landscape to newer smaller heights."

Seagate Momentus Thin Hard Drive Hugely Small




Laptop hard drives have to be small. The form factor dictates it. Now Seagate pushes the envelope with a 7mm drive – shaving around 2.5mm off of the thickness of the drive. What’s next, paper thin?

Though it does spin at 5400rpm, it does maintain very good storage ratios. It comes in 250GB and 160GB versions. It also support SATA connections and even the SATA 3 protocol. All this means very good bandwidth in a small package. The 250GB version will cost $55 when it comes out in January.

Thin is in.

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