Cartilage Grafts for Damaged Knees
Nanofiber scaffolds seeded with patient-derived stem cells could repair ravaged joints.
MIT Technology Review, May 11, 2009, by Emily Singer — Our joints are one of the first body parts to suffer the inevitable ravages of aging: cartilage may be torn in overzealous basketball games or slowly worn away over years of use. Scientists are now experimenting with a combination of stem cells and novel scaffold materials designed to mimic real tissue, in hopes of permanently vanquishing the pain that accompanies this damage and perhaps preventing the onset of arthritis. In animal models, these transplants appear to spur regeneration of cartilage that better resembles native tissue.
Cartilage damage accrues from both trauma and normal wear and tear, often culminating in osteoarthritis, a degenerative joint disease that affects about half of the population by age 65. Existing treatment for small cartilage defects typically involves inflicting additional damage on the injured joint, to encourage cell-rich blood and bone marrow to clot in the area. Or treatment involves transplants of cartilage cells, called chondrocytes, collected from a healthy joint, then grown in culture and injected into the damaged area. Both procedures trigger growth of new tissue, a scarlike version of cartilage that is more fibrous than regular cartilage and doesn’t seem to have the same durability.
“It’s like a pothole filler,” says Rocky Tuan, chief of the Cartilage Biology and Orthopedics Branch at the National Institute of Arthritis and Musculoskeletal and Skin Diseases, in Baltimore. “It’s not the same as resurfacing, but if the stuff hangs in there, it will last a couple of winters and it’s fine.”
In an effort to truly regenerate cartilage rather than simply patch it, Tuan and his colleagues have developed a nanofiber scaffold that’s structurally similar to the extracellular matrix, a fibrous material that provides support to connective tissue in the body.The scaffold is generated via electrospinning, a process adopted from the textiles industry. The researchers apply a strong electric field to a liquid polymer, which forms into long fibers in an attempt to dissipate the charge. The fibers are collected in a tangled ball, much like cotton candy.
The nanoscale structure of the material is key: experiments have shown that cells grow better on a nanoscale fiber scaffold than on a millimeter-scale one made of the same material. “These scaffolds are more on the scale of what a cell would normally see,” says Farshid Guilak, director of the Orthopaedic Bioengineering Laboratory, at Duke University, in Durham, NC, who was not involved in the research.
The scaffolds are seeded with mesenchymal stem cells–adult stem cells derived from bone marrow, fatty tissue, and other sources, and which can be differentiated into muscle, bone, fat, and cartilage. “The advantage is that you don’t have to damage other tissue to get the cells,” says Tuan.
In a recent pilot experiment in pigs, researchers sutured the cell-laden scaffolds over damaged cartilage in the animals’ knees. Six months later, new tissue had formed, with a smooth surface and mechanical properties similar to those of native cartilage. The tissue also expressed molecular markers characteristic of normal cartilage. “Ultimately, it’s important for this new tissue to have an extracellular matrix made of native cartilage molecules so that, in the long term, the properties of new tissue will emulate that of real cartilage,” says Alan Grodzinsky, director of the Center for Biomedical Engineering, at MIT, who was not involved in the work.
The stem-cell-seeded scaffolds repaired the damage better than scaffolds with no cells or those seeded with ordinary cartilage cells, although scientists don’t yet know why. It may be because the stem cells proliferate better than cartilage cells, or because they are more receptive to molecular signals coming from the wounded tissues.
A number of other tissue-engineering approaches using cell transplants, scaffold materials, or a combination of the two are currently under way, including some in clinical trials. (The most advanced of them use one or the other, largely because it is easier to gain approval from the Food and Drug Administration this way.) Tuan says that he aims to begin human tests in the next two years. First, his team must do additional studies in large animals, such as goats or sheep, over a longer period of time, to make sure that the treatment is safe and effective. The polymer that Tuan uses is already approved for medical use, and the cells would come from the patients themselves, eliminating risk of immune rejection.
Tuan’s group is also working on making the scaffolds bioactive, tagging them with biological molecules that encourage growth of the appropriate cells. Ultimately, he would like to design a system in which stem cells can be collected from the patient and immediately delivered to the scaffold without culturing, which would then be transplanted into the patient.
The growing blue state-red state gap over this research shows that science has serious economic and political muscle in America today.
Salon.com, May 11, 2009, by Peter Dizikes — When Barack Obama removed George W. Bush’s ban on federal funding for new embryonic stem cell research in March, the president cast his decision as part of a larger effort to remove politics from science. No longer would research, Obama said, be shackled by a “false choice between sound science and moral values.”
It turns out the president cannot separate politics and science so easily. No sooner had Obama issued his order than conservative lawmakers in state legislatures began proposing new restrictions on embryonic stem cell research, ranging from criminal penalties to bans on state-level funding. In fact, Obama’s decision has emboldened conservatives to increasingly link stem cell research to abortion. Far from conceding the issue, they are in it for the long haul.
But the stem cell battle is not just a high-profile clash of values. The dispute provides a sharp focus on how science may help reshape America. Several states have set aside billions of dollars to support stem cell research, and the new federal money Obama is promising will generally flow to those areas. That means states supporting stem cell research will experience an economic windfall while attracting highly educated technology workers who tend to vote Democratic. The more conservative states restricting stem cell research will attract fewer funds and fewer socially liberal voters. In short, a state’s stem cell policy will influence electoral results and help determine whether a state turns red or blue.
At the moment, stem cell science mirrors November’s electoral map. Twelve states allow the use of public money to fund stem cell research — and Obama won them all in 2008. Four states have moved to either restrict stem cell research or limit public expenditures for it since Obama’s announcement — and they all voted for John McCain. But now that map could change.
In stem cell politics, key battlegrounds include Georgia, Texas and Arizona — red states where Obama and the Democrats made inroads. These are places that have significant academic and scientific infrastructures but that Republicans control politically. Restrictions on science there could slow the kind of economic growth associated with Democratic support. At the same time, the GOP is putting its popularity at risk by curbing research that most voters support. The new regional political dynamic of the stem cell war is set.
Most cells are specialized. Your various forms of white blood cells fight illnesses, while red blood cells help oxygen circulate in the body. Stem cells are unspecialized, waiting to be assigned roles. If we could give stem cells the right biological instructions, we could use them to repair damaged body parts such as heart muscle cells, limiting heart disease.
Adult stem cells help maintain a particular bodily organ or tissue. The brain has its own reserve supply of adult stem cells. But embryonic stem cells have not yet been directed to a particular body part, increasing their potential value. They might help fix any organ or tissue.
Extracting the stem cells from a days-old embryo, usually acquired from an in vitro fertilization clinic, destroys the embryo. Many scientists have argued that since clinics produce more embryos than they use, employing the remaining ones for medicine is ethically justified. But stem cell research opponents disagree and have responded by trying to alter the practices of fertility clinics.
In 2007, researchers announced the development of induced pluripotent stem cells (IPSCs) in humans — adult cells reprogrammed to mimic embryonic stem cells. In theory, IPSCs could bring the political battle over stem cells to an end, since producing them does not involve embryos. But many scientific hurdles remain to be cleared before IPSCs can be considered a safe and complete replacement for embryonic stem cells.
In 2001, Bush announced a ban on federal funding of embryonic stem cell research, except for work on a limited number of already existing stem cell “lines.” Since then, 12 states have funded stem cell research themselves. California’s program, at $3 billion, is the biggest. The state aims to build a dozen stem cell facilities at universities and other research institutes and says it has awarded more than $600 million in research money so far.
The overall economic impact of the biotech industry is even greater than the numbers suggest, as industry earnings create a “multiplier effect” that ripples through a local economy. In California, such activity includes the construction workers building the new Mission Bay research facility for the University of California at San Francisco, and the service industries that grow around well-paid technology workers. A 2004 Milken Institute report estimated that every biotechnology job in California creates an additional 3.5 jobs. In 2003, industry earnings in California totaled about $5 billion but created about $21 billion in overall economic output.
States not investing in stem cell science are missing out on this bonanza. Not only is this part of biotech economically regenerative, but it’s also popular. A 2007 Gallup Poll showed that by a 64-to-30 margin, Americans think embryonic stem cell research is “morally acceptable.” But social conservatives such as Oklahoma state Rep. Mike Reynolds, disagree. Reynolds introduced a bill making it a misdemeanor to conduct research on embryonic stem cells. “I am a pro-life candidate, and I believe life begins at conception,” Reynolds says.
In Georgia, a bill under consideration would put limits on both stem cell research and in vitro fertility clinic practices. “A person is a person no matter how small,” says Dan Becker, president of Georgia Right to Life. “There is a paradigm shift going on, a shift toward personhood. You’re going to see more states adopt that strategy.” Indeed, bills in Texas and Mississippi would bar state funding for embryonic stem cell research. Arizona is among the states already featuring similar laws.
But Georgia best exemplifies the political and economic issues at stake. The state “is a prime example of the legislative revolt as a result of Obama’s executive order,” says Patrick Kelly, director of state government relations at Bio, an umbrella group representing biotechnology firms.
Georgia may be red on electoral maps, but in November, Obama lost to McCain there by a mere 5 points — the best showing by any Democratic presidential candidate, apart from Southerners Bill Clinton and Jimmy Carter, since 1960. Democratic challenger Jim Martin forced incumbent Republican U.S. Sen. Saxby Chambliss to a runoff with a 3-point loss, although Chambliss’ subsequent 15-point victory shows that a real gap still exists.
In March, the Georgia Senate passed a stem cell bill that limits new embryonic stem cell research and prevents couples who use in vitro fertilization clinics from authorizing the destruction of their own remaining embryos. The state House of Representatives may take up the bill in the fall. The measure shows how conservatives are linking stem cell research to abortion by promoting the “personhood” of embryos.
“We’ve been good at spinning many antiabortion scenarios,” Becker says. “What we’ve failed to do is personalize the embryo issue. We’re shifting and attacking the position that in the first trimester this is nothing other than a medical blob. This is a human being.” Georgia Right to Life has created television spots to reinforce the message.
The bill’s opponents emphasize their own moral interests. The legislation “would tell patients that we are not interested in helping them,” says Charles Craig, president of Georgia Bio, which is lobbying against the bill along with various patients’ rights organizations.
As far as the economic consequences, Craig believes that “if Georgia were to restrict science considered legal and ethical by the federal government, it would send a message that Georgia is out of step, and possibly anti-science and anti-technology.”
Biotech backers want to develop the state’s Innovation Crescent, running from Atlanta to Athens, which features research universities including Georgia Tech, Emory and the University of Georgia. The state’s life science industry has grown 140 percent since 1993, although the state lags in some measures. While ninth in population in the U.S., Georgia ranked 22nd in the number of biotech workers in 2003.
Stem cell research can be funded in at least four ways: federal funds, state money, private gifts and venture capital. Banning state funds eliminates only one income stream. But that can lead to substantial economic disparities. In 2006, New York’s state agencies, which are vigorously pursuing biotech growth, spent about $100 million more on scientific research and development than did Georgia’s, nearly five times as much per capita.
State funds attract additional research dollars, magnifying these discrepancies. One modest piece of legislation in California, the Roman Reed Spinal Cord Injury Research Act, named for a young man who was paralyzed playing football, authorized $12.5 million in state funding — but garnered $50 million in matching grants.
“There’s a huge push-pull effect,” says Don Reed, Roman Reed’s father, who is now vice president of Americans for Cures, a stem cell research advocacy group. “If I were running a state, I would not wait to set up a funding program. It’s going to help their economies.”
Kelly agrees. “Places that have put in place stem cell programs also have more scientific infrastructure and an indigenous research community,” he says. “And they will continue to lead the charge because they’re that much further ahead.”
On the other hand, state funding bans can be both a symbolic and a tangible deterrent to scientists — and hinder a state’s economy. In a 2005 Science paper, researchers Joanna Kempner, Clifford Perlis and John Merz found that scientists pursuing controversial research feel cornered not only by formal restrictions — like funding laws — but also by social pressures. “Informal limitations are more prevalent and pervasive than formal constraints,” they write.
Texas-based journalist Bill Bishop, coauthor of “The Big Sort,” a book about the social polarization of America, has discussed the problem of social stigmatization with Houston-area scientists. “They were saying, ‘I don’t want to live some place where I’m considered immoral,'” Bishop says. “They pick up these signals and they don’t want to work in a setting where they will feel shunned.” Likewise, Craig suggests, “If Georgia is singled out as a state restricting this research, it could give scientists pause about coming here.”
Stem cell opponents, in Georgia or elsewhere, are unconcerned with economic fallout. “I have no interest in supporting the economy of murdering unborn children,” says Reynolds, the Oklahoma legislator.
But if state support for stem cell science makes an economic difference, does it matter at the ballot box? Although scientists and technology workers are hardly a unified voting bloc, expanding a regional science community seems to increase the number of educated, socially liberal voters. And that helps Democrats. In the 2008 election, 17 percent of the electorate had attended graduate school, and those voters supported Obama by a 58-40 ratio, compared to his overall 53-46 margin of victory.
Most likely, highly educated voters have already colored the electoral map in North Carolina, poster child for biotechnology growth. In the Raleigh-Durham area’s Research Triangle, local leaders have aggressively recruited biotech firms and promoted the region’s universities as sources of intellectual capital. In the state, Obama beat McCain by 13,692 votes, but won the 13 self-identified Research Triangle counties by 145,498 votes. That’s over 100,000 more than Bill Clinton’s Research Triangle margin in 1992. And while more than one factor explains this increase — high turnout, student vote — North Carolina’s high-tech growth surely helped turn the state blue in 2008.
“If you look at where states are growing, it’s the urban areas, and clearly technology plays a leading role,” says Ruy Teixeira, coauthor of “The Emerging Democratic Majority.” “Biotechnology is one of the things that create growth, with implications politically. The effect is that it will make those areas more progressive.” Georgia could follow the same general pattern. “I don’t think it’s far out of reach,” Teixeira says, citing the potential for economic changes in the Atlanta area. “That’s going to be the ground where a shift takes place.” It certainly has room to grow. Georgia is slightly bigger than North Carolina in population, yet according to the Milken Institute numbers, the biotech business accounts for only about 17,000 jobs in Georgia, compared with 127,000 jobs in North Carolina.
To be sure, there are only so many biology Ph.D.s out there who vote. “The question is, What gets you from tens of thousands of high-tech voters to a larger change in voting patterns?” says Andrew Gelman, director of the Applied Statistics Center at Columbia University and coauthor of the book “Red State, Blue State, Rich State, Poor State.” One prominent type of answer comes from economic theorist Richard Florida, who believes information-age cities are magnets for “creative class” workers, perpetuating a blend of high-tech growth and social liberalism. Teixeira calls these places “ideopolises.”
Biotechnology’s future jobs will also be filled by the young, who trend heavily Democratic: Obama won the 18-to-29 age group by a 66-32 ratio. Georgia has a young population, although the creative-class thesis holds that such workers follow jobs across the map. In Texas, there is a potent research infrastructure, albeit in a large state, and multiple institutes have started stem cell research in recent years. These include the M.D. Anderson Cancer Center in Houston, the Heart Hospital of Austin, and the University of Texas Southwestern Medical School in Dallas, among others. But according to the Milken survey, the state had just one-third the biotech revenue of North Carolina.
Arizona seems like another Democratic target. Obama lost by just 8 points on McCain’s home turf, and Janet Napolitano was a popular Democratic governor. Today, Arizona State University, in traditionally GOP-friendly Maricopa County, has been attempting a huge science-based expansion. But the state’s embryonic stem cell research ban may be one reason it is in the lower half of the national rankings in biotech revenue. That is a continued roadblock in a state that Democrats find tantalizing in electoral terms. “Maricopa County used to be strongly Republican,” Teixeira says. “If Democrats get close enough to win there, they can win in Arizona. Texas is a little further away.”
Purple-shaded Missouri, which allows but does not fund embryonic research, is another state to watch. And the battleground states that Obama happened to win, which also fund stem cell science — Florida, Ohio, Virginia, even Indiana — remain highly contested, meaning the Democrats could benefit from further creative-class development.
The stem cell skirmishes epitomize the problems that Republicans are having as they grapple with the future. For now the GOP is reaching into its old playbook, trying to energize its base through cultural politics, with no guarantee that the stem cell debate will take place on their terms. “Stem cell research is popular,” Gelman says. “That’s where the Democrats want the battle to be. The Republicans want the battle to be about abortion.” State-level politicians from conservative districts may be staging a rear-guard action that displeases the larger public — and many Republicans nationally. A Gallup Poll from February, just before Obama’s stem cell decision, showed 39 percent of Republicans agreeing that embryonic stem cell research restrictions should be eased or eliminated.
Wedge issues are supposed to split the other party, not your own. Currently the GOP’s stem cell opposition seems more like an effort to forestall the kinds of social and economic changes that help Democrats, instead of providing a way forward for Republicans. Indeed, to consider the deep limitations of the GOP’s position, ask one question: What if stem cell research does create a major breakthrough? “If stem cells provided a cure for juvenile diabetes, this issue would be a whisper in the wind,” says Kelly. For now the battle continues, but it’s clear which way the wind is blowing.
SeekingAlpha.com, May 11, 2009 — The stem cell trade was back in a big way over the past week, with several stocks in the ETF Innovators Stem Cell Index registering impressive gains, compared to market and biotech ETF benchmarks such as the S&P 500 SPDR (NYSE:SPY) +6%, iShares Nasdaq Biotech (NASDAQ:IBB) +2%, SPDR S&P Biotech (NYSE:XBI +4%). Hot stocks over the past week among the 40 component companies in the stem cell index include NeoStem (AMEX:NBS) +52.2%, Cytori Therapeutics (NASDAQ:CYTX) +37%, and Geron (NASDAQ:GERN) +22%. Two other widely followed stocks from the index registered smaller gains, including Osiris Therapeutics (NASDAQ:OSIR) +6% and StemCells (NASDAQ:STEM) +1%.
Last week, NeoStem filed a patent application covering cosmetic stem cell face lift technology while simultaneously announcing an expansion to its stem cell collection network, which is located at the Giampapa Institute for Anti-Aging Medical Therapy in Montclair, New Jersey. NeoStem also signed a deal for the exclusive worldwide rights to an innovative technology and pending patents that involve using a patient’s own stem cells derived from their bone marrow to promote healing of chronic wounds.
As highlighted in this article at Schaeffer’s Research, Geron experienced major call option buying and a large stock price gain in the past week in the absence of any major news. In January, the FDA cleared the way for Geron to conduct a human clinical trial for GRNOPC1 in patients with acute spinal cord injury.
On Friday, CYTX announced an 18-month deal with GE Healthcare (NYSE:GE) to commercialize Cytori’s StemSource cell banking technology in North America (expected U.S. launch during 1H09) to serve the markets for stem cell banking and research. The deal expands upon an agreement announced between the two companies in January that calls for GE Healthcare to commercialize Cytori’s Celution 800/CRS System in 10 European countries to serve the cosmetic, reconstructive medicine, stem cell banking, and research markets.
ChicagoTribune.com, GoogleNews.com, May 11, 2009 — The world’s largest drugmaker has signed a license with the Wisconsin Alumni Research Foundation to use human embryonic stem cells.
Pfizer Medicine’s chief scientific officer, Ruth McKernan, says her company will use the cell lines to “explore a whole new range of therapies.” McKernan says potential uses include creating specialized human tissue and new medicines that improve the way cells regenerate damaged tissue.
With annual revenue of more than $48 billion, Pfizer is the biggest of the 35 companies to sign an embryonic stem cell license with the foundation.
WARF holds several key patents that are based on the work of James Thomson, a University of Wisconsin-Madison scientist.
Using DNA origami, researchers have assembled a nano-sized box with lock and key.
MIT Technology Review, May 11, 2009, by Jocelyn Rice — Using nothing but DNA, researchers in Denmark have constructed a tiny box with a lid that can either lock shut or–with the help of a set of DNA keys–hinge open. While other groups have experimented with using DNA origami to build three-dimensional objects, the new box, described in this week’s edition of Nature, is distinguished by its solid sides and moving parts.
“It’s a rather beautiful molecular structure,” says John Reif, a distinguished professor of computer science at Duke University, who was not involved in the research. “It’s the first time that a nanostructure like that had a programmable and controllable lid.”
For now, the box serves as a proof of principle that DNA origami can be adapted to make elaborate three-dimensional structures, says Jørgen Kjems, a molecular biologist at the Aarhus University Center for DNA Nanotechnology, who led the research. But in the future, he believes that the nano-sized container could be adapted for a wide range of applications, from drug-delivery vehicle to logic gate.
DNA makes an ideal building material for nanostructures. It’s easy to churn out in bulk: Kjems and his team hijacked a virus to manufacture copies of the sequence that they designed. And it folds in straightforward, predictable ways according to its sequence. To design the box, the Aarhus team developed a computer program to generate a continuous single-stranded DNA sequence that, along with smaller DNA fragments that act as staples, would self-assemble into the desired shape.
The sequence was devised with many complementary regions so that it would automatically fold into six roughly square accordion-like sheets–the sides of the box–based on DNA’s natural tendency to pair into double strands. The DNA staples, also driven by the pairing of complementary sequences, stitched the sheets’ edges together to form a hollow cube with a hinged lid.
To make the lid lockable, Kjems and his colleagues fashioned two tiny DNA latches with sticky ends. Under normal circumstances, the latches adhere to the box, holding it shut. But when the two corresponding DNA keys are added, the latches bind to those instead, allowing the lid to swing open. A pair of dye molecules, one affixed to the box’s rim and another to its lid, glow red when close together and green when far apart, providing an easy way to detect whether a box is closed or open.
With three-dimensional structures such as this one, the real challenge isn’t designing the object but proving that it successfully formed, says Paul Rothemund, a computer scientist at the California Institute of Technology, who developed a simple technique for making DNA structures. The researchers used several different imaging methods to ensure that the boxes assembled themselves as planned. “They did a very convincing job of showing that they made what they thought they made, which is really important,” Rothemund says. “And now they’re free to try and elaborate on it and get it to actually do something.”
Kjems has several ideas for what the boxes might do. One possibility is to load them with drugs and program the lids to open in response to some biological cue inside the body–the presence of a virus or a cancer gene, for example–thereby releasing their therapeutic cargo.
“There’s a way in which they’re more interesting than almost any other nano-encapsulation scheme you can think of for that purpose, because they have these infinitely programmable lids,” says Rothemund. “That’s something that no other kind of nano-drug-delivery capsule can offer.”
Therapeutic uses are still a long way off, however. While the boxes are theoretically solid enough to prevent large molecules from leaking out and spacious enough to enclose a ribosome or a small virus, the researchers haven’t yet tried to put anything inside them. And so far, the boxes only function inside a test tube. Unlike some other nano-delivery vehicles, there’s no evidence yet of the safety or efficacy of DNA-based devices in living systems.
But the lockboxes needn’t carry a payload to prove useful. Kjems also envisions turning them into electronic components. Because they have two distinct keys, the boxes act as AND gates, opening (and glowing green) only when both keys are present. With a few straightforward tweaks, they could serve as NOT gates or OR gates as well. “In principle,” says Kjems, “you could build a DNA computer using these boxes.”
An elastic conductor makes possible cheap, conformable displays.
MIT Technology Review, May 11, 2009, by Prachi Patel — Researchers at the University of Tokyo have moved a step closer to displays and simple computers that you can wear on your sleeve or wrap around your couch. And they have opened up the possibility of printing such devices, which would make them cheap.
Takao Someya, an electrical-engineering professor, and his colleagues make a stretchable display by connecting organic light-emitting diodes (OLEDs) and organic transistors with a new rubbery conductor. The researchers can spread the display over a curved surface without affecting performance. The display can also be folded in half or crumpled up without incurring any damage.
In a previous Science paper, the researchers used their elastic conductor–a mix of carbon nanotubes and rubber–to make a stretchy electronic circuit. The new version of the conductor, described online in Nature Materials, is significantly more conductive and can stretch to more than twice its original size. What’s more, it can be printed. Combined with printable transistors and OLEDs, this could pave the way for rolling out large, cheap, wearable displays and electronics.
Bendy, flexible electronics that can be rolled up like paper are already available. But rubber-like stretchable electronics offer the additional advantage that they can cover complex three-dimensional objects. “With a sheet of paper, you can wrap a cylinder or a cone, but that’s pretty much it,” says John Rogers, a professor of materials science and engineering at the University of Illinois at Urbana-Champaign. “You can’t wrap a body part, a sphere, or an airplane wing.”
To make such materials, researchers have tried several approaches. Rogers uses ultrathin silicon sheets to make complex circuits on stretchy surfaces–he recently demonstrated a spherical camera sensor using the circuits. Others have made elastic conductors using graphene sheets or by combining gold and rubbery polymers.
The new carbon nanotube conductor offers the advantage of being printable. “The main advance is that they’re able to print elastic conductors that are highly conductive and highly stretchable,” says Stephanie Lacour, who studies stretchable electronic skin at the University of Cambridge, in England. “Printing is cheap, and it allows you to cover large-area substrate.”
Someya first combines carbon nanotubes with an ionic liquid–a liquid containing charged molecules–and a liquid polymer to make a nanotube-rubber paste. Then comes the crucial part: a high-pressure jet that spreads the nanotubes in the rubber.
The jet makes the nanotube bundles thinner without shortening them and disperses the bundles uniformly in the polymer. “The longer and finer bundles of nanotubes can form well-developed conducting networks in rubbers, thus significantly improved conductivity and stretchability,” Someya says. The jet process also increases the material’s viscosity, making it suitable for high-definition screen printing.
The researchers use a printing mask to deposit 100-micrometer-wide lines of the conductor on a piece of rubber. Then they use the lines as a wire grid to connect organic transistors and OLEDs–a transistor addresses each OLED pixel–to make a display that can stretch by up to 50 percent of its original shape. “This work is very impressive,” Rogers says. “The data shows that they can stretch and deform these displays without changing the property of the pixels too much.”
Many other applications could be possible with the stretchable wiring. The researchers could use it to make sensitive artificial skin for robots or prosthetic limbs. Instead of using OLEDs, they would use pressure sensors on the printed conductor. The electrodes could also be used in implantable medical devices to study or repair body organs.
Someya says that Tokyo-based Dai Nippon Printing is interested in commercializing the stretchable display, and a product should be possible in five years. But first, the researchers need to make higher-resolution displays by printing conductor lines narrower than 100 micrometers.
Our exclusive test shows how the two Web engines compare when given the same queries.
MIT Technology Review, May 11, 2009, by David Talbot — Last week, as physicist Stephen Wolfram was demonstrating his new Web-based “computation engine”–Wolfram Alpha–to the public, Google announced a data-centric service of its own. Alpha accesses databases that are maintained by Wolfram Research, or licensed from others, and deploys formulas and algorithms to compute answers for searchers.
Using some prelaunch log-in credentials provided by the Wolfram team, I decided to run my own Wolfram Alpha versus Google test. I used a handful of search terms that could produce data-centric answers and tried variations in a few cases to see what might happen.
This was an effort to get beyond the characterizations and produce some real data. I also wanted to explore the claims made during my visit to Wolfram Research last week: that Alpha can add unique value in computing answers based on your search queries.
Here’s what I entered, and what I found.
SEARCH TERM: Microsoft Apple
WOLFRAM ALPHA: I got side-by-side tables and graphics on the stock prices and data on the two companies, plus a chart plotting the price of both stocks over time.
GOOGLE: The top hits were mostly news stories, from major and minor publications, containing both words.
VARIATION: When I changed the Google search term to just “Microsoft” or just “Apple,” I got a chart with today’s stock price up top; when I clicked that link, I received tons of information–comparable to what Alpha provides–but only on the single company.
SEARCH TERM: Sydney New York
WOLFRAM ALPHA: I got tables showing the distance between the two cities in miles, kilometers, meters, even nautical miles; a map of the world with the optimal flight path; and the fact that the trip spans 0.4 of the earth’s circumference. I learned how long it would take to make the trip: 18.1 hours flying; 13 hours for a sound wave, 74 milliseconds for a light beam in fiber, and 53 milliseconds for a light beam traveling in a vacuum. I also got comparative populations, elevation in meters, and current local times.
GOOGLE: I got a mix of things: a form for finding flights between Sydney and New York; a Google Maps-plotted list of businesses in New York City that contain the word “Sydney”; and links to the municipal government of Sidney, a small town in upstate New York.
VARIATION: When I tried “Sydney New York distance” (adding the word “distance”), Wolfram gave me only the distance information mentioned above while Google gave me links to distance-finding websites. I opened the first one, was able to enter “New York” and “Sydney” in some forms, and wound up with much the same information provided by Wolfram (but without the light-beam and sound-wave details).
SEARCH TERM: 10 pounds kilograms
WOLFRAM ALPHA: The site informed me that it interpreted my search term as an effort to multiply “10 pounds” by “1 kilogram” and gave me this result: 4.536 kg2 (kilograms squared) or 22.05 lb2 (pounds squared).
GOOGLE: Google gave me links to various metric conversion sites.
VARIATIONS: Adding the word “in” changed everything. When I tweaked the search query to say “10 pounds in kilograms,” the Wolfram site gave me the correct conversion: 10 pounds equals 4.536 kilograms. It also gave me the volumes (in various units) of 10 pounds of water. In a final, somewhat cheesy touch, it also told me that 10 pounds was 1.8 times the weight of Wolfram’s book, A New Kind of Science. In Google’s case, this revised search term produced the helpful calculated result up top: 10 pounds = 4.5359237 kilograms.
When I put in “10 lbs kgs,” Alpha gave me the calculated result (the assumption was that I wanted multiplication), as it had with the full words. Google gave me metric conversion sites–the top one was a “Russian Brides Cyber Guide.” (It offers both brides and metric conversions.)
When I tried “10 pds kgs,” Alpha choked and didn’t understand. Google helpfully asked if I meant “pounds” and gave me metric conversion sites, but not the calculated result.
SEARCH TERM: light bulb
WOLFRAM ALPHA: I was expecting some facts and figures on this ubiquitous technology but got a message saying that Wolfram Alpha “isn’t sure what to do with your input.”
GOOGLE: I got several links–starting with a Wikipedia entry–explaining what a light bulb is and providing some history.
VARIATIONS: When I tried “light bulb inventor,” I got similar results: Alpha drew a blank, but Google gave useful links. When I tried “first light bulb,” Alpha provided a table explaining that the light bulb was patented in 1878; under “people involved,” it cited Thomas Edison.
SEARCH TERM: Aspirin Tylenol
WOLFRAM ALPHA: Alpha gave me molecular diagrams for aspirin and acetaminophen and lots of scientific information comparing their molecular weights, boiling points, vapor pressure, and so forth.
GOOGLE: Usefully (to nonchemists suffering from headaches), the top link was to a Wiki-answers page telling people whether they can take aspirin and Tylenol together. Other links gave information about toxicity, danger to kidneys, and the like.
SEARCH TERM: Stanford Harvard
WOLFRAM ALPHA: I got tables comparing data from the two schools: size of student bodies–broken down by full-time, part-time, undergraduate, and graduate–plus the number of undergraduate, master’s, and doctoral degrees awarded, and similar data. Alpha listed Stanford’s tuition as $25,000, which is incorrect, and no tuition for Harvard. As with all of Alpha’s results, it gave me sources against which to check the information.
GOOGLE: Google gave me a collection of links (starting with a discussion board for students trying to make a college decision) and various news stories containing the two terms.
SEARCH TERM: Cancer New York
WOLFRAM ALPHA: I was expecting statistics on cancer rates in New York. Instead, the Wolfram site assumed I meant the constellation. It showed me where Cancer could be found in the night sky viewed from New York, told me when it would next rise and set, and included a map of the night sky.
GOOGLE: The first link was to Memorial Sloan-Kettering Cancer Center in New York. The second was to the New York State Department of Health’s cancer page. The third was to the New York State Cancer Registry. Not bad.
VARIATIONS: Adding a second state (Cancer New York Nevada) confused Wolfram–it didn’t know what I wanted. With Google, all the top results were Nevada-centric: a mix of news stories, lawyers’ websites, and medical centers relating to cancer (the disease) in Nevada. No comparisons, no data, and not as helpful as it was when I just put “Cancer New York.”
SEARCH TERM: Utah Florida population
WOLFRAM ALPHA: Alpha gave me tables containing the two states’ populations from 2006, the population growth rate from 2000 to 2006 (including a chart that I could download), and the number of annual births and deaths in 2004.
GOOGLE: Even though Google just launched a new data-presentation service with access to public census and labor data, this search term did not bring me to the new data service. The first hit was to a U.S. census press release that itself contained links to population tables.
VARIATIONS: When I tried “Utah population,” Google did give me a view of its new service: a simple chart of Utah’s population from 1980 to the present.
When I changed the search term to “Utah Florida,” Wolfram threw the almanac at me, giving side-by-side tables on population data plus high and low elevations of the two states, the dates that the states joined the union, the area of farmland, the household income and poverty rates, and so on. Google gave me random sites that contained the two words, starting with a mapped location of a business in Lake Mary, Florida, that contains the word “Utah.”
Generally, I did not use search terms that clearly had no computable answer (and therefore would have stumped Wolfram). But I also didn’t throw any softballs in areas close to the heart of its makers: physics, chemistry, engineering, and genomics. On hard-core scientific questions, it gives you tons of symbols and graphics and other information that would be useful to a researcher but obscure to most people. But on many common questions for which there is no obvious data element, you will not get much help. In any event, if its plans hold, you should be able to test it out yourself in two or three weeks.
Education.zdnet.com, May 11, 2009, by Christopher Dawson — Set to launch this month, Wolfram Alpha promises to be the next big thing from the same guy who transformed mathematical software. Ahead of its launch, though, we’re seeing some details emerge that may position it as more of a Google Supplement than a Google killer. In fact, the more I read about it, the more Alpha seems like the moral equivalent of LinkedIn while Google is decidedly MySpace-esque. Both have value and both have a solid place in the market.
Don’t get me wrong. Regular readers know that I have quite an infatuation with Google. Used correctly, its search tools put a whole lot of information at your fingertips and its Apps suite is about the best thing since sliced bread. However, the sheer volume of results that Google searches can churn up are daunting at best and can make it a remarkably challenging tool in education, especially for those without the wherewithal to search well (and yes, it is our responsibility to give them the wherewithal, but there’s a whole lot of information floating about on the web, in case you haven’t noticed).
Alpha, on the other hand, seeks to make all of this information “computable,” so that when someone asks it a question, it provides an answer. Google is giving this a shot with their Public Search tool, but as Hiawatha Bray points out in the Boston Globe,
For now, Google Public Search is rudimentary. Users who type queries like “unemployment in Massachusetts” see a graph at the top of the page. Clicking on it provides a more detailed view of the data, as well as links to let you compare Massachusetts with other states and break out the numbers by county.
But Wolfram Alpha, which will be available for public use later this month at http://wolframalpha.com, offers detailed, math-based responses to a huge variety of questions.
Google has also attempted to add semantic search capabilities (and I’m sure will get there sooner than later; they’re Google, after all), but so far, this doesn’t give you much. On the other hand, Alpha already seems to be pretty good at knowing what you mean. For example,
Type “snickers,” and Alpha assumes you are talking about the popular candy bar. It displays a complete list of ingredients, nutritional values, and total calories. Type “half snickers,” and it shows how many calories you will save by not finishing the bar.
Google currently has the advantage of volume. Its bots and spiders give us access to whatever we want, as long as we can come up with a good search term. Alpha, however, relies on some serious computation and a bit more voodoo. Again, as Bray notes,
Wolfram says Alpha is still relatively ignorant. His team of developers is constantly adding statistical databases to expand the range of the service.
|Credit: USDA (switchgrass in the foreground); US Dept. of Energy (tower)|
Findings show that turning biomass into electricity is more beneficial than turning it into transportation fuels.
MIT Technology Review, May 11, 2009, by Tyler Hamilton — A study published today in Science concludes that, on average, using biomass to produce electricity is 80 percent more efficient than transforming the biomass into biofuel. In addition, the electricity option would be twice as effective at reducing greenhouse-gas emissions. The results imply that investment in an ethanol infrastructure, even if based on more efficient cellulosic processes, may prove misguided. The study was done by a collaboration between researchers at Stanford University, the Carnegie Institute of Science, and the University of California, Merced.
There’s also the potential, according to the study, of capturing and storing the carbon dioxide emissions from power plants that use switchgrass, wood chips, and other biomass materials as fuel–an option that doesn’t exist for burning ethanol. Biomass, even though it releases CO2 when burned, overall produces less carbon dioxide than do fossil fuels because plants grown to replenish the resource are assumed to reabsorb those emissions. Capture those combustion emissions instead and sequester them underground, and it would “result in a carbon-negative energy source that removes CO2 from the atmosphere,” according to the study.
The researchers based their findings on scenarios developed under the Biofuel Analysis Meta-Model (EBAMM) created at the University of California, Berkeley. The analysis covered a range of harvested crops, including corn and switchgrass, and a number of different energy-conversion technologies. Data collected were applied to electric and combustion-engine versions of four vehicle types–small car, midsize car, small SUV, and large SUV–and their operating efficiencies during city and highway driving.
The study accounted for the energy required to convert the biomass into ethanol and electricity, as well as for the energy intensiveness of manufacturing and disposing of each vehicle type. Bioelectricity far outperformed ethanol under most scenarios, although the two did achieve similar distances when the electric vehicles–specifically the small car and large SUV–weren’t designed for efficient highway driving.
The potential is even greater for the bioelectricity option because under the EBAMM model, “we did not account for heat as a [usable] by-product, which would make the electricity pathway even more advantageous,” says Elliott Campbell, lead author on the study and an assistant professor at the Sierra Nevada Research Institute, part of the University of California, Merced.
Mark Jacobson, a professor of civil and environmental engineering at Stanford University, conducted a similar but much broader study released in December that focused more on the environmental effects of various energy options. He doesn’t support using biomass for either electricity generation or ethanol production but says that he isn’t surprised to find that the ethanol option performed worst.
Burning biomass, says Jacobson, “is not necessarily an efficient way of generating electricity, but it’s more efficient than making biofuel.” It just makes sense, he adds: “Electric vehicles are four to five times more efficient than combustion vehicles.”
But Vincent Chornet, president of Montreal-based cellulosic ethanol producer Enerkem, says that it would be a mistake to pick winners: there’s room for both options. In places where the infrastructure isn’t capable of supporting the mass charging of electric cars, next-generation biofuels are the only other option, he says. Adding biofuels also offers a solution for air travel and heavy transportation that electricity and the current state of battery technology can’t address.