Wednesday, February 6, 2008
Body-centered-cubic" unit cells of the 3-D nanoparticle crystals. One type of nanoparticle occupies each corner of the cube and a second type of nanoparticle is located centrally inside. These unit cells, measuring tens of nanometers, form a repeating lattice that extends more than a micron (1,000 nanometers) in three dimensions. (Credit: Image courtesy of DOE/Brookhaven National Laboratory)
'Holy Grail' Of Nanoscience: DNA Technique Yields 3-D Crystalline Organization Of Nanoparticles
In an achievement some see as the "holy grail" of nanoscience, researchers at the U.S. Department of Energy's Brookhaven National Laboratory have for the first time used DNA to guide the creation of three-dimensional, ordered, crystalline structures of nanoparticles (particles with dimensions measured in billionths of a meter). The ability to engineer such 3-D structures is essential to producing functional materials that take advantage of the unique properties that may exist at the nanoscale - for example, enhanced magnetism, improved catalytic activity, or new optical properties.
"From previous research, we know that highly selective DNA binding can be used to program nanoparticle interactions," said Oleg Gang, a scientist at Brookhaven's Center for Functional Nanomaterials (CFN), who led the interdisciplinary research team, which includes Dmytro Nykypanchuk and Mathew Maye of the CFN, and Daniel van der Lelie of the Biology Department. "But while theory has intriguingly predicted that DNA can guide nanoparticles to form ordered, 3-D phases, no one has accomplished this experimentally, until now."
As with the group's previous work, the new assembly method relies on the attractive forces between complementary strands of DNA - the molecule made of pairing bases known by the letters A, T, G, and C that carries the genetic code of living things. First, the scientists attach to nanoparticles hair-like extensions of DNA with specific "recognition sequences" of complementary bases. Then they mix the DNA-covered particles in solution. When the recognition sequences find one another in solution, they bind together to link the nanoparticles.
This first binding is necessary, but not sufficient, to produce the organized structures the scientists are seeking. To achieve ordered crystals, the scientists alter the properties of DNA and borrow some techniques known for traditional crystals.
Importantly, they heat the samples of DNA-linked particles and then cool them back to room temperature. "This 'thermal processing' is somewhat similar to annealing used in forming more common crystals made from atoms," explained Nykypanchuk. "It allows the nanoparticles to unbind, reshuffle, and find more stable binding arrangements."
The team also experimented with different degrees of DNA flexibility, recognition sequences, and DNA designs in order to find a "sweet spot" of interactions where a stable, crystalline form would appear.
Results from a variety of analysis techniques, including small angle x-ray scattering at the National Synchrotron Light Source and dynamic light scattering and different types of optical spectroscopies and electron microscopy at the CFN, were combined to reveal the detail of the ordered structures and the underlying processes for their formation. These results indicate that the scientists have indeed found that sweet spot to create 3-D nanoparticle assemblies with long-range crystalline order using DNA.
The crystals are remarkably open, with the nanoparticles themselves occupying only 5 percent of the crystal lattice volume, and DNA occupying another 5 percent. "This open structure leaves a lot of room for future modifications, including the incorporation of different nano-objects or biomolecules, which will lead to enhanced nanoscale properties and new classes of applications," said Maye. For example, pairing gold nanoparticles with other metals often improves catalytic activity. Additionally, the DNA linking molecules can be used as a kind of chemical scaffold for adding small molecules, polymers, or proteins.
Furthermore, once the crystal structure is set, it remains stable through repeated heating and cooling cycles, a feature important to many potential applications.
The crystals are also extraordinarily sensitive to thermal expansion - 100 times more sensitive than ordinary materials, probably due to the heat sensitivity of DNA. This significant thermal expansion could be a plus in controlling optical and magnetic properties, for example, which are strongly affected by changes in the distance between particles. The ability to effect large changes in these properties underlies many potential applications such as energy conversion and storage, as well as sensor technology.
The Brookhaven team worked with gold nanoparticles as a model, but they say the method can be applied to other nanoparticles as well. And they fully expect the technique could yield a wide array of crystalline phases with different types of 3-D lattices that could be tailored to particular functions.
"This work is the first step to demonstrate that it is possible to obtain ordered structures. But it opens so many avenues for researchers, and this is why it is so exciting," Gang says.
The research will be published in the January 31, 2008, issue of the journal Nature.
This research was funded by the Division of Materials Science and Engineering in the Office of Basic Energy Sciences within the U.S. Department of Energy's Office of Science.
Nanotechnology: holy grail or grey goo?
As governments at the 6th WTO Ministerial in Hong Kong bristle with the thorny politics of trade, the report that ETC Group releases today, Oligopoly, Inc. 2005, serves as a reminder that what looks like buying and selling between countries is most often the redistribution of capital among subsidiaries of the same parent multinational corporation. Researcher Mark Baxendale looks behind the hype and the scare stories at 'the next big thing' in science, nanotachnology
Capitalism, forever in search of updated means of production, has seized upon nanotechnology as a panacea for its present ills and invested huge amounts in research programmes. Nanotechnology is the control of the properties of matter by defining shape and size at the nanometre scale—billionths of a metre. Nanoscience is the study of physical phenomena at atomic and molecular scales.
The possibilities offered by nanotechnology and nanoscience have been hyped to attract investors to such an extent that it is almost guaranteed to be a disappointment. The short term benefits of nanotechnology will be very mundane or frivolous. The biggest private sector investors in nanoparticle research are cosmetics companies.
Nanotechnology has also generated serious concerns among anti-capitalist activists, echoing the debates around genetically modified foods. Some of this concern draws on Eric Drexler's 1986 book, Engines of Creation, in which he predicted self-reproducing nanoscale machines.
The fear generated by this vision, popularised by Michael Crichton's novel Prey, is that a self-reproducing molecular machine could be designed to consume life and reduce us all to "grey goo".
In 2000, one informed commentator, Bill Joy, said that research into nanotechnology should stop immediately, as developments in the wrong hands could end life as we know it.
There is debate about whether the grey goo theory is a real possiblity. The nanoparticles being researched and used today are not self-reproducing and several hundred years of scientific endeavour have given us little insight into how to achieve self-reproduction.
Self-reproduction is a feature of biology, for example ribosome synthesises protein molecules according to a specification embedded in an organism's DNA. But nature has had a "research and development" time of several billion years, and the prospect of us out-designing nature is remote.
However, there are pressing concerns about the health implications of nanoparticles in the body. Nanoparticles can pass through biological cell walls so the interaction with our bodies is at a much deeper level than for larger molecules such as asbestos that get trapped in the lungs.
Lobby groups have raised this issue—Greenpeace have called for 10 percent of funding to be dedicated to health studies. Such studies have commenced but there has been no sign of any research funding from New Labour yet.
We should insist on the highest safety standards for those working with free nanoparticles, but we should also do so for by far the greatest producer of carbon nanoparticles, namely the car engine. We should also insist on the highest standards of toxicology for those cosmetics companies already using nanoparticles.
Nanotechnology does promise to bring real benefits—especially in healthcare and the search for renewable energy sources. At the tiny scales nanoscience deals with, the properties of matter differ significantly from those of our familiar everyday world, opening up new possibilities for science and technology.
For example, the gold and silver used in jewellery is inert—it is stable and unreactive. But gold nanoparticles can speed up certain chemical reactions and silver nanoparticles kill bacteria.
Embedding nanoparticles in another material can also drastically alter its properties. For example, rubber can be strengthened by mixing in carbon nanoparticles and dispersed gold nanoparticles give glass a deep red colour.
These changes to the properties of rubber and glass have been known about for some time. What's new is that through nanoscience we are beginning to understand why these changes take place.
New developments, particularly in microscopy, microelectronics and molecular biology, have provided tools for us to explore nature on the nanoscale.
The manufacture of components in microelectronics now takes places on such a small scale that the "top-down" processes (analogous to carving a statue out of rock) are converging with the "bottom-up" processes (analogous to building a house from individual bricks).
Scientists are now exploring the possibility of self-assembled electronic components using technologies borrowed from molecular biology.
The convergence of different fields of science as old boundaries break down at the nanoscale is an important aspect of nanoscience, and one of the joys of working in this field. Another example of this is the quantum dot—a device developed for telecommunications now used in the body to selectively kill off cancerous cells.
If we are to maximise the benefits of nanotechnology, we should not leave control of this field to the "band of warring brothers", as Karl Marx called the capitalist classes of the world.
Social movements, including some of those involved in this work, can be a powerful force arguing that nanotechnology should be used to meet social needs.
Posted by SANJIDA AFROJ at 11:54 PM
Cable operators announced the start off of repair works at two of the three broken undersea cables that were disrupted last week outside the Egyptian city of Alexandria, causing Internet access problems throughout Middle East and India. The repair works will take at least a week to be completed, according to Flag Telecom, one of the firms responsible for the cable.
The cause of the disruption remains unknown, as cable operators are working on restoring the Internet connections as soon as possible. According to several reports, India has lost 60% of its bandwidth, and according to Rajesh Chharia, president of the Internet Service Providers’ Association, things aren’t expected to return to normal for the next 10 days.
The investigations continue, but more information is to be expected as soon as all the repairing crews will reach the broken cables. One of the theories was that a tanker might have dragged its anchor on the sea bed, but the Egyptian communication ministry said no ships were reported in the area at the time of the disruption.
Not all cables have been damaged simultaneously. On January 30, Flag Telecom Europe-Asia cable and SEA-ME-WE-4 cable were disrupted outside the Mediterranean coast of Egypt, and two day later, on February 1st, the Falcon cable, also owned by Flag Telecom, was damaged 56 km from Dubai. Consequently one question appears: Could this be a simple coincidence?
The impact in countries around the Gulf Region and South Asia had been minimized through redirecting communication services to new routes, but it is certain that Internet connection haven’t exactly been the best following the unfortunate incident. Egypt for example lost 70% of its Internet capacity and will continue to face this problem within the next week and a half.
The repair teams have been delayed by bad weather conditions on the Egyptian and Dubai coasts. At the same time, conspiracy theories have appeared, according to which the ‘perfect timing’ was simply too perfect to be a coincidence, and this whole thing could be an attempt to deprive some Islamic countries of Internet access. More details on the exact causes of the disruption are to be expected within the next week.
CAIRO, EGYPT: Work starts on cut Internet cable
A repair ship began work in the Persian Gulf on Tuesday at the site where an Internet cable was cut last week, and a second vessel was to arrive later at the spot north of Egypt to work on two other cables cut two days earlier, FLAG Telecom said.
The cuts have disrupted Internet services across much of the Mideast and India.
There has been speculation that the cuts were caused by ships' anchors that dragged along the bottom of the sea in stormy weather. But Egypt's telecommunication ministry said no ships were registered near the first cable cut.
Posted by SANJIDA AFROJ at 5:17 PM
Yet another iTunes competitor is going down the bit bucket--Yahoo will close its Music Unlimited service and move its remaining subscribers over to RealNetworks' Rhapsody later this year.
Yahoo explained the move yesterday in a post on its corporate blog:
Around 25 million people visit Yahoo! Music each month. Relatively speaking, a small percentage of those use Yahoo! Music Unlimited, yet an large portion of our resources were being poured into this service. It was clear to us that we needed to make a major strategic shift.
The post goes on to say that Yahoo subscribers will be able to "easily take their music catalogs and migrate to Rhapsody." But a press release at Real's site notes that these people will wind up paying more for "a limited time" after they're moved over to Rhapsody. Where Yahoo charges $8.99 a month for unlimited, "tethered" downloads to a computer (or $5.99/month if you prepay for a year), Rhapsody's equivalent service costs $12.99 a month.
Yahoo's pricing advantage was even stronger when it launched the service. But as the company ratcheted up its prices, then mysteriously dumped the "To Go" option that allowed copying these rented downloads to certain "PlaysForSure" music devices, Yahoo Music Unlimited had less and less to distinguish itself from Rhapsody and other services.
Some things are still unclear after Yahoo's announcements:
1) Now that the Yahoo Music Jukebox program--which has already suffered from years of neglect--no longer has a reason to live, when will the company put it out of its misery? And how much longer will it take for computer manufacturers to stop bundling this mediocre application?
2) How long will Yahoo wait to take down the "TRY IT FREE" promotional page inviting visitors to sample this soon-to-be-defunct service?
If you subscribe to Yahoo Music Unlimited, I'd like to hear your take on this. Do you feel jilted or relieved?
Yahoo! Music the Latest to Fall on Apple's Sword
The online music subscription service market is shrinking.
The latest company to exit the market is Yahoo!(YHOO - Cramer's Take - Stockpickr), which has decided to move its subscribers to RealNetworks'(RNWK - Cramer's Take - Stockpickr) Rhapsody service.
The market shift underscores a point that Apple(AAPL - Cramer's Take - Stockpickr) CEO Steve Jobs has made all along -- namely that people like to own music and not rent it, a strategy that has paid off handsomely for the iPod.
Yahoo!'s exit leaves only three big players, RealNetworks, Microsoft(MSFT - Cramer's Take - Stockpickr) and Napster(NAPS - Cramer's Take - Stockpickr), remaining in the subscription music game.
Yahoo! said Monday it has partnered with Rhapsody, the digital music service from RealNetworks and Viacom's(VIA - Cramer's Take - Stockpickr) MTV Networks, to replace its music service with Rhapsody's.
In the next few months, Yahoo!'s music subscribers will switch to Rhapsody's digital music service. They will hold on to their existing pricing for a limited time before being charged a new fee. Yahoo! has claimed more than 25 million people visit Yahoo! Music a month, but only a fraction of them pay for the premium subscription service.
Yahoo! and Rhapsody also intend to partner on services like digital downloads -- a move that is unlikely to cause Apple to break into a sweat. Apple said more than 4 billion songs were downloaded last year from its iTunes store.
The deal sets the stage for a potential clash between the Yahoo!-Rhapsody service and Microsoft's Zune subscription product as Microsoft attempts to gobble up Yahoo!. Microsoft made a $44.6 billion, or $31 a share, unsolicited bid for Yahoo! last week.
"One of the problems with on-demand subscription services is that they haven't been able to go beyond a niche audience because most music lovers are on the iPod," says David Card, an analyst with Jupiter Research.
The RealNetworks-Yahoo! deal was about taking a competitor out, he says. "The marketplace is not very crowded now," says Card.
For Apple, the shrinking marketplace for music subscription services comes at a time when investors and analysts worry about the future of the iPod.
In the last quarter iPod sales grew 5% compared with 50% in the year-ago quarter, with growth in U.S. sales nearly flat. Apple has hinted that it will refresh the iPod line and turn it into a wireless mobile platform.
Apple shares closed down $2.10, or 1.6%, to $131.65 Monday. The stock is nearly 35% off from its 52-week high.
Last year, Apple also introduced music free of digital rights management. Since then Amazon.com has started offering DRM-free music in a move that some felt could eat into downloads from the iTunes store.
Yahoo Music's latest move shows Apple may have made the right bet. "Yahoo saw that all the major record labels have moved towards selling music without DRM, which makes it impossible to run a music subscription service," says Phil Leigh, senior analyst, with market research firm Inside Digital Media. "It also shows that the dominant player in the market is iPod and it has set the standards."
The Yahoo-Rhapsody deal also raises not just questions of potential competition in the future between Microsoft's Zune platform and the Yahoo-Rhapsody service but also Microsoft own strategy with the Zune.
"If the Microsoft-Yahoo merger is completed, we believe the integration of the two companies will be a lengthy process and competitive conflicts between Microsoft's online music store, its Zune digital media players and the Rhapsody service will likely emerge but over a longer timeframe," says Ingrid Ebeling, an analyst with JMP Securities in a research note. JMP makes a market in RealNetwork shares.
Shares of Yahoo closed up 95 cents, or 3.3%, to $29.33 Monday, while Microsoft fell 26 cents to $30.19.
For RealNetworks, though, the latest development even in a small market is good news. "This is a good idea for them because this consolidates the monthly music services business and shows Rhapsody from RealNetworks is becoming the market leader."
Posted by SANJIDA AFROJ at 1:57 AM
Apple doubles iPhone, iPod Touch capacity
Apple doubled the capacity of the iPhone and the iPod Touch on Tuesday for an additional $100.
The iPhone once again comes in two capacities: 8GB for $399 and now 16GB for $499. Apple sold 8GB and 4GB varieties on iPhone Day, but it discontinued the 4GB model after it cut the price of the 8GB model to $399. Something like 90 percent of all early iPhone buyers opted for the 8GB version.
Apple thinks that there's still room for an 8GB iPhone in the mix, said Greg Joswiak, Apple's vice president of worldwide iPod and iPhone product marketing. The first time around, people signaled pretty clearly that they wanted more than 4GB of storage, but he thinks that there's still a "sweet spot" at 8GB of storage.
And the iPod Touch can also store more music and videos now, with 32GB of capacity for $499. That device is now available in three versions, with Apple also selling a 16GB model for $399 and an 8GB model for $299.
The new iPhone and iPod Touch appear to be unchanged from their previous incarnations, though they ship with the new software unveiled at Macworld, which provides the ability to edit the home screen and triangulate your position using Maps.
The release of that software really changed the iPod Touch into a new type of device, Joswiak said, and Apple is now playing up the iPod Touch as a "Wi-Fi mobile device," as opposed to a high-end iPod. "It becomes even more promising, once we enter the world of the SDK," he said, referring to the expected release of the software developer's kit for the iPhone and iPod Touch in late February.
Both are available immediately. This move should give something of a boost to iPhone and iPod Touch sales. Apple shipped fewer iPods than expected during the fourth quarter but still grew iPod revenue at a strong pace, suggesting that the higher-priced iPod Touch is gaining ground against the iPod Nano and Shuffle as a percentage of Apple's iPod mix.
The iPhone story is a little more complicated. The rampant unlocking of the smartphone makes it both harder and easier to understand iPhone demand: On one hand, people want the iPhone so badly, they are willing to take risks to use it on their network or in their country. On the other hand, it's almost impossible to get a true number of how many phones have been unlocked.
This time around, there's no price cut on existing models, which some prognosticators felt was necessary in order to spike iPhone demand during the leaner first and second quarters of the year.
Given the price cut debacle the first time around, I wouldn't expect to see the price of the iPhone change too dramatically any time soon, at least until the 3G model is unveiled.
Still, I'd imagine that most people who intended to spend $399 on an iPhone would be willing to cough up another hundred bucks to get twice as much storage. As might be expected, Joswiak concurred, saying the higher prices for twice as much storage reflects that the "value proposition remains." We'll see if the public agrees.
Apple beefs up iPhones and iPods
Apple is muscling up on memory for its popular iPhone and iPod touch devices - doubling the amount of music, photos and videos people can store on them for an extra $100.
The iPhone - part phone, multi-media player and WiFi gadget - is now available in two versions: the new 16-gigabyte model sells for $499, and the older 8GB device retails for $399.
The Cupertino company added a third model to its line of iPod touch devices. The latest model comes with 32GB of memory and is priced at $499. The two older versions come with 16GB of memory, for $399, and 8GB, for $299.
"For some users, there's never enough memory," said Greg Joswiak, Apple's vice president of Worldwide iPod and iPhone Product Marketing.
The new devices, which are now available through the company's online and retail stores, come loaded with software updates announced at Macworld last month. They include the ability to rent and watch movies through Apple's online iTunes store and a maps application.
Posted by SANJIDA AFROJ at 1:48 AM