Molecular Machine Could Hold Key to More Efficient Manufacturing

08:06 Kalyan Gupta 0 Comments


Molecular Machine Could Hold Key to More Efficient Manufacturing

Jan. 10, 2013 — An industrial revolution on a minute scale is taking place in laboratories at The University of Manchester with the development of a highly complex machine that mimics how molecules are made in nature.
Professor Leigh’s molecular machine is based on the ribosome. It features a functionalized nanometre-sized ring that moves along a molecular track, picking up building blocks located on the path and connecting them together in a specific order to synthesize the desired new molecule. First the ring is threaded onto a molecular strand using copper ions to direct the assembly process. Then a “reactive arm” is attached to the rest of the machine and it starts to operate. The ring moves up and down the strand until its path is blocked by a bulky group. The reactive arm then detaches the obstruction from the track and passes it to another site on the machine, regenerating the active site on the arm. The ring is then free to move further along the strand until its path is obstructed by the next building block. This, in turn, is removed and passed to the elongation site on the ring, thus building up a new molecular structure on the ring. Once all the building blocks are removed from the track, the ring de-threads and the synthesis is over. (Credit: Miriam Wilson)
The artificial molecular machine developed by Professor David Leigh FRS and his team in the School of Chemistry is the most advanced molecular machine of its type in the world. Its development has been published in the journal Science.
Professor Leigh explains: "The development of this machine which uses molecules to make molecules in a synthetic process is similar to the robotic assembly line in car plants. Such machines could ultimately lead to the process of making molecules becoming much more efficient and cost effective. This will benefit all sorts of manufacturing areas as many humanmade products begin at a molecular level. For example, we're currently modifying our machine to make drugs such as penicillin."
The machine is just a few nanometres long (a few millionths of a millimetre) and can only be seen using special instruments. Its creation was inspired by natural complex molecular factories where information from DNA is used to programme the linking of molecular building blocks in the correct order. The most extraordinary of these factories is the ribosome, a massive molecular machine found in all living cells.
Professor Leigh's machine is based on the ribosome. It features a functionalized nanometre-sized ring that moves along a molecular track, picking up building blocks located on the path and connecting them together in a specific order to synthesize the desired new molecule.
First the ring is threaded onto a molecular strand using copper ions to direct the assembly process. Then a "reactive arm" is attached to the rest of the machine and it starts to operate. The ring moves up and down the strand until its path is blocked by a bulky group. The reactive arm then detaches the obstruction from the track and passes it to another site on the machine, regenerating the active site on the arm. The ring is then free to move further along the strand until its path is obstructed by the next building block. This, in turn, is removed and passed to the elongation site on the ring, thus building up a new molecular structure on the ring. Once all the building blocks are removed from the track, the ring de-threads and the synthesis is over.
Professor Leigh says the current prototype is still far from being as efficient as the ribosome: "The ribosome can put together 20 building blocks a second until up to 150 are linked. So far we have only used our machine to link together 4 blocks and it takes 12 hours to connect each block. But you can massively parallel the assembly process: We are already using a million million million (1018) of these machines working in parallel in the laboratory to build molecules."
Professor Leigh continues: "The next step is to start using the machine to make sophisticated molecules with more building blocks. The potential is for it to be able to make molecules that have never been seen before. They're not made in nature and can't be made synthetically because of the processes currently used. This is a very exciting possibility for the future."
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Graphene Plasmonics Beats the Drug Cheats

07:25 Kalyan Gupta 0 Comments


Graphene Plasmonics Beats the Drug Cheats

Jan. 13, 2013 — Wonder material graphene could help detect the presence of drugs or toxins in the body or dramatically improve airport security, University of Manchester researchers have found.
Wonder material graphene could help detect the presence of drugs or toxins in the body or dramatically improve airport security, University of Manchester researchers have found. (Credit: Image courtesy of University of Manchester)
Writing in Nature Materials, the scientists, working with colleagues from Aix-Marseille University, have created a device which potentially can see one molecule though a simple optical system and can analyse its components within minutes. This uses plasmonics -- the study of vibrations of electrons in different materials.
The breakthrough could allow for rapid and more accurate drug testing for professional athletes as it could detect the presence of even trace amounts of a substance.
It could also be used at airports or other high-security locations to prevent would-be terrorists from concealing explosives or traffickers from smuggling drugs. Another possible use could be detecting viruses people might be suffering from.
Graphene, isolated for the first time at The University of Manchester in 2004, has the potential to revolutionise diverse applications from smartphones and ultrafast broadband to drug delivery and computer chips.
It has the potential to replace existing materials, such as silicon, but University of Manchester researchers believe it could truly find its place with new devices and materials yet to be invented.
The researchers, lead by Dr Sasha Grigorenko, suggested a new type of sensing devices: artificial materials with topological darkness. The devices show extremely high response to an attachment of just one relatively small molecule. This high sensitivity relies on topological properties of light phase.
To test their devices, researches covered them with graphene. They then introduced hydrogen onto the graphene, which allowed them to calibrate their devices with far superior sensitivity than with any other material.
Testing for toxins or drugs could be done using a simple blood test, with highly-accurate results in minutes. The researchers found that the sensitivity of their devices is three orders of magnitude better than that of existing models.
The academics, from the School of Physics and Astronomy, hope the research will show the practical applications from an emerging area of research -- singular optics.
Dr Grigorenko said: "The whole idea of this device is to see single molecules, and really see them, under a simple optical system, say a microscope.
"The singular optics which utilise the unusual phase properties of light is a big and emerging field of research, and we have shown how it can have practical applications which could be of great benefit.
"Graphene was one of the best materials we could have used to measure the sensitivity of these molecules. It is so easy to put the hydrogen on to it in controlled way.
"We are only starting to scratch the surface of what this research might tell us but it could have profound implications for drug detection, security and viruses."
Professor Andre Geim and Professor Kostya Novoselov won the Nobel prize for Physics in 2010 for their groundbreaking work on graphene.
source:sciencedaily.
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First Plant Material Found On Ancient Hominins' Teeth

07:23 Kalyan Gupta 0 Comments


First Plant Material Found On Ancient Hominins' Teeth

June 27, 2012 — A 2 million-year-old mishap that befell two early members of the human family tree has provided the most robust evidence to date of what at least one pair of hominins ate.
A quirk of nature allowed scientists to scrape plant material out of preserved plaque found on the teeth of two specimens of Australopithecus seidba. (Credit: Photo by Brett Eloff, courtesy Lee Berger and the University of the Witwatersrand.)
A team of researchers including Peter Ungar, Distinguished Professor of anthropology at the University of Arkansas, reports its findings June 27 in the journal Nature.
Almost 2 million years ago, an elderly female and young male of the species Australopithecus sediba fell into a sinkhole, where their remains were quickly buried in sediment. In 2010, anthropologist Lee Berger of the Institute for Human Evolution at the University of the Witwatersrand in Johannesburg, South Africa, and his colleagues described the remains of this newly characterized creature. Now a team of scientists has studied the teeth of these specimens, which proved to have unique properties because of how the hominins died.
"We have a very unusual type of preservation," Ungar said. "The state of the teeth was pristine." Since the two individuals were buried underground and quickly encased in sediment, parts of the teeth were even preserved with a pocket of air surrounding them. Because of this, the researchers were able to perform dental microwear analyses of the tooth surfaces and high-resolution isotope studies of the tooth enamel on these well-preserved teeth. In addition, because the teeth had not been exposed to the elements since death, they also harbored another thing not discovered before in early hominins -- areas of preserved tartar buildup around the edges of the teeth. In this plaque, the scientists found phytoliths, bodies of silica from plants eaten almost 2 million years ago by these early hominids.
"It's the first time we've been able to look at these three things in one or two specimens," Ungar said.
Using the isotope analysis, the dental microwear analysis and the phytolith analysis, the researchers closed in on the diet of these two individuals, and what they found differs from other early human ancestors from that period. The microwear on the teeth showed more pits and complexity than most other australopiths before it. Like the microwear, the isotopes also showed that the animals were consuming mostly parts of trees, shrubs or herbs rather than grasses.
The phytoliths gave an even clearer picture of what the animals were consuming, including bark, leaves, sedges, grasses, fruit and palm.
"We get a sense of an animal that looked like it was taking advantage of forest resources," Ungar said. This kind of food consumption differs from what had been seen in evidence from other australopiths. "They come out looking like giraffes in terms of their tooth chemistry. A lot of the other creatures there were not eating such forest resources." "These findings tell us a really nice story about these two individuals," Ungar said. "It's fascinating that we found something that went into the mouth of these creatures that was still in the mouth of these creatures."
Ungar conducted the microwear analysis. Amanda Henry of the Max Planck Institute in Leipzig, Germany; Marion Bamford of the University of Witwatersrand; and Lloyd Rossouw of the National Museum Bloemfontein in South Africa conducted the analysis of the phytoliths. Benjamin Passey of Johns Hopkins University; Matt Sponheimer and Paul Sandberg of the University of Colorado at Boulder; and Darryl de Ruiter of Texas A&M conducted the isotope analysis. Lee Berger of the University of Witwatersrand oversaw the project.
ource:sciencedaily.

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Nanoparticles Reach New Peaks

03:03 Kalyan Gupta 0 Comments


Nanoparticles Reach New Peaks: Researchers Show Short Laser Pulses Selectively Heat Gold Nanoparticles

Jan. 3, 2013 — Plasmonic gold nanoparticles make pinpoint heating on demand possible. Now Rice University researchers have found a way to selectively heat diverse nanoparticles that could advance their use in medicine and industry.
Different types of nanoparticles – in this case, shells, rods and solid spheres – mixed together can be activated individually with pulsed laser light at different wavelengths, according to researchers at Rice University. The tuned particles’ plasmonic response, enhanced by nanobubbles that form at the surface, can be narrowed to a few nanometers under a spectroscope and are easily distinguishable from each other. (Credit: Lapotko Group/Rice University)

Rice scientists led by Dmitri Lapotko and Ekaterina Lukianova-Hleb showed common gold nanoparticles, known since the 19th century as gold colloids, heat up at near-infrared wavelengths as narrow as a few nanometers when hit by very short pulses of laser light. The surprising effect reported in Advanced Materials appears to be related to nonstationary optical excitation of plasmonic nanoparticles. Plasmons are free electrons on the surface of metals that become excited by the input of energy, typically from light. Moving plasmons can transform optical energy into heat.
"The key idea with gold nanoparticles and plasmonics in general is to convert energy," Lapotko said. "There are two aspects to this: One is how efficiently you can convert energy, and here gold nanoparticles are world champions. Their optical absorbance is about a million times higher than any other molecules in nature.
"The second aspect is how precisely one can use laser radiation to make this photothermal conversion happen," he said. Particles traditionally respond to wide spectra of light, and not much of it is in the valuable near-infrared region. Near-infrared light is invisible to water and, more critically for biological applications, to tissue.
"This was the problem," Lapotko said. "All nanoparticles, beginning with solid gold colloids and moving to more sophisticated, engineered gold nanoshells, nanorods, cages and stars, have very wide spectra, typically about 100 nanometers, which means we were allowed to use only one type of nanoparticle at a time. If we tried to use different types, their spectra overlapped and we did not benefit from the high tunability of lasers."
The discovery allows controlled laser pulses to tune the absorbance spectrum of plain gold colloids, Lapotko said. "This novel approach is counter to the established paradigm that assumes optical properties of nanoparticles are pre-set during their fabrication and stay constant during their optical excitation," he said.
The Rice lab showed basic colloidal gold nanoparticles could be efficiently activated by a short laser pulse at 780 nanometers, with an 88-fold amplification of the photothermal effect seen with a continuous laser. The researchers repeated their experiment with nanoparticle clusters in water, in living cancer cells and in animals, with the same or better results: they showed spectral peaks two nanometers wide. Such narrow photothermal spectra had never been seen for metal nanoparticles, either singularly or in clusters.
The effect appears to depend on vapor nanobubbles that form when the particles heat liquid in their immediate environment. The nanobubbles grow and burst in an instant. "Instead of using the nanoparticle as a heat sink with a continuous, stationary laser, we're creating a transient, nonstationary situation in which the particle interacts with the incident laser in a totally different way," Lapotko said. He said the effect is repeatable and works with laser pulses shorter than 100 picoseconds.
Even better, an experiment with mixed nanorods and nanoshells found they responded to laser pulses with strong, distinct signals at wavelengths 10 nanometers apart. That means two or more types of nanoparticles in the same location can be selectively activated on demand.
"The nanoparticles we used were nothing fancy; they were used in the 19th century by Michael Faraday, and it was believed they could do nothing in the near-infrared," he said. "That was the major motivation for people to invent nanorods, nanoshells and the other shapes. Here, we prove these inexpensive particles can behave quite well in near-infrared." He said the discovery opens the possibility that many metal nanoparticles could be used in biomedical and industrial applications where spectral selectivity and tuning would provide "unprecedented" precision.
"This is still more a phenomenon rather than a firmly established mechanism, with a nice theoretical basis," Lapotko said. "But when fully clarified, it could become a universal tool."
Co-authors of the paper are Alexey Volkov, a research scientist at the University of Virginia, and Xiangwei Wu, an associate professor in the Department of Head and Neck Surgery at the University of Texas MD Anderson Cancer Center. Lapotko is a faculty fellow in biochemistry and cell biology, and Lukianova-Hleb is a research scientist at Rice.
The National Institutes of Health supported the research.
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Nanoparticles Reach New Peaks

06:14 Kalyan Gupta 0 Comments


Nanoparticles Reach New Peaks: Researchers Show Short Laser Pulses Selectively Heat Gold Nanoparticles

Jan. 3, 2013 — Plasmonic gold nanoparticles make pinpoint heating on demand possible. Now Rice University researchers have found a way to selectively heat diverse nanoparticles that could advance their use in medicine and industry.
Different types of nanoparticles – in this case, shells, rods and solid spheres – mixed together can be activated individually with pulsed laser light at different wavelengths, according to researchers at Rice University. The tuned particles’ plasmonic response, enhanced by nanobubbles that form at the surface, can be narrowed to a few nanometers under a spectroscope and are easily distinguishable from each other. (Credit: Lapotko Group/Rice University)
Rice scientists led by Dmitri Lapotko and Ekaterina Lukianova-Hleb showed common gold nanoparticles, known since the 19th century as gold colloids, heat up at near-infrared wavelengths as narrow as a few nanometers when hit by very short pulses of laser light. The surprising effect reported in Advanced Materials appears to be related to nonstationary optical excitation of plasmonic nanoparticles. Plasmons are free electrons on the surface of metals that become excited by the input of energy, typically from light. Moving plasmons can transform optical energy into heat.
"The key idea with gold nanoparticles and plasmonics in general is to convert energy," Lapotko said. "There are two aspects to this: One is how efficiently you can convert energy, and here gold nanoparticles are world champions. Their optical absorbance is about a million times higher than any other molecules in nature.
"The second aspect is how precisely one can use laser radiation to make this photothermal conversion happen," he said. Particles traditionally respond to wide spectra of light, and not much of it is in the valuable near-infrared region. Near-infrared light is invisible to water and, more critically for biological applications, to tissue.
"This was the problem," Lapotko said. "All nanoparticles, beginning with solid gold colloids and moving to more sophisticated, engineered gold nanoshells, nanorods, cages and stars, have very wide spectra, typically about 100 nanometers, which means we were allowed to use only one type of nanoparticle at a time. If we tried to use different types, their spectra overlapped and we did not benefit from the high tunability of lasers."
The discovery allows controlled laser pulses to tune the absorbance spectrum of plain gold colloids, Lapotko said. "This novel approach is counter to the established paradigm that assumes optical properties of nanoparticles are pre-set during their fabrication and stay constant during their optical excitation," he said.
The Rice lab showed basic colloidal gold nanoparticles could be efficiently activated by a short laser pulse at 780 nanometers, with an 88-fold amplification of the photothermal effect seen with a continuous laser. The researchers repeated their experiment with nanoparticle clusters in water, in living cancer cells and in animals, with the same or better results: they showed spectral peaks two nanometers wide. Such narrow photothermal spectra had never been seen for metal nanoparticles, either singularly or in clusters.
The effect appears to depend on vapor nanobubbles that form when the particles heat liquid in their immediate environment. The nanobubbles grow and burst in an instant. "Instead of using the nanoparticle as a heat sink with a continuous, stationary laser, we're creating a transient, nonstationary situation in which the particle interacts with the incident laser in a totally different way," Lapotko said. He said the effect is repeatable and works with laser pulses shorter than 100 picoseconds.
Even better, an experiment with mixed nanorods and nanoshells found they responded to laser pulses with strong, distinct signals at wavelengths 10 nanometers apart. That means two or more types of nanoparticles in the same location can be selectively activated on demand.
"The nanoparticles we used were nothing fancy; they were used in the 19th century by Michael Faraday, and it was believed they could do nothing in the near-infrared," he said. "That was the major motivation for people to invent nanorods, nanoshells and the other shapes. Here, we prove these inexpensive particles can behave quite well in near-infrared." He said the discovery opens the possibility that many metal nanoparticles could be used in biomedical and industrial applications where spectral selectivity and tuning would provide "unprecedented" precision.
"This is still more a phenomenon rather than a firmly established mechanism, with a nice theoretical basis," Lapotko said. "But when fully clarified, it could become a universal tool."
Co-authors of the paper are Alexey Volkov, a research scientist at the University of Virginia, and Xiangwei Wu, an associate professor in the Department of Head and Neck Surgery at the University of Texas MD Anderson Cancer Center. Lapotko is a faculty fellow in biochemistry and cell biology, and Lukianova-Hleb is a research scientist at Rice.
The National Institutes of Health supported the research.
source:sciencedaily
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Use for Old Christmas Trees?

06:13 Kalyan Gupta 0 Comments


Use for Old Christmas Trees? Douglas Fir Needles May Sterilize Nano Devices for Medical Applications

Jan. 2, 2013 — As Twelfth Night approaches and the Christmas decorations start to look old, as the last crumbs of cake are swept away and the remnants of the turkey have finally been consumed, there is the perennial question as to what to do with the tree. Research published in the International Journal of Biomedical Nanoscience and Nanotechnologysuggests that the needles of the plant Pseudotsuga menziesii, commonly known as the Douglas fir could be used to sterilize nano devices destined for medical applications.
Chemist Poushpi Dwivedi of MNNIT in Allahabad, India, and colleagues explain that one of the most troubling problems in biomedicine is bacterial infection at the site of implanted medical devices, prosthetics and sensors. They explain that despite advances in sterilization procedures and aseptic measures pathogenic microbes can still invade biomaterials and tissues. The researchers are developing an antimicrobial, self-sterilizing composite material derived from Douglas fir needles that is essentially a silver/chitosan bionanocomposite that can be used to safely coat medical implants and surgical devices to preclude microbial growth.
The team points out that silver nanoparticles have been tested widely for their potential as antimicrobial agents given that silver is well known to have bactericidal properties. They point out that using biological agents has come to the fore as an efficient and effective way to make novel types of silver nanoparticles with uniform size and shape and biocompatible surfaces for use in medicine. The team has now used an extract from Pseudotsuga menzietii together with silver nitrate solution to generate nanoparticles. These particles can then be readily dispersed in chitosan polymer to make a material that can coat metals and other materials. The plant extract acts as a natural chemical reducing agent to convert the silver ions in the nitrate solution to nanoscopic silver metal particles.
"The size and the percentage of the particles produced can be easily controlled, according to the requirement, by the initial concentration of the metal precursor and volume of the plant biomass," the team explains. So, as you are sweeping up the last fallen needles from your Christmas tree come Twelfth Night, think on, those needles could underpin the next medical shot in the arm.
source:sciencedaily
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What Happens on the web in 30 Seconds

09:13 Kalyan Gupta 0 Comments


What Happens on the web in 30 Seconds



What can you do in just 30 seconds?!  Surprisingly, not much as what can be done on the web in the same amount of time – 30 SECONDS.  Wow!
In fact it will take you not more than just 30 seconds to read this post or to read the information shown in this weird infographic.
While you’re reading it, or maybe just as soon as you blinked, there are tons of data and information being shared, posted and bookmarked on the world wide web!
Read the information below carefully and let us see if you are up to take the challenge:

WHAT HAPPENS ON THE WEB IN 30 SECONDS!

  • 20,400 GB of global IP data transferred
  •  70+ BotNet Infections
  • 12 New victims of identity theft
  • 3+ New Wikipedia Articles published
  • 102 Million Emails sent
  • 700 new Mobile Users
  •  25.000 App downloads
  • $45,000 sales on Amazon
  • 31,141 hours of music played on Pandora
  • 55+ New linked in Accounts
  •  Over 10 Millions photo Views, 3500+ Photo uploads on Flickr
  • 165 + New Twitter accounts, 50,000+ New Tweets
  • 150,000 Facebook Log ins  3M+ Facebook Views , 350,000 Status update, 40,000+ Wall posts, 205,010 comments
  • Over 1 million Search queries on Google
  • 15+ Hours of video uploaded – 6.1 Video views on YouTube
  • 25+ WordPress downloads, 75 plugin downloads
  • 1000+ Firefox downloads
  • 30+ New Blogs, 1000+ blog posts
  • 50+ Domain registered
  • 7000+ Iphone App downloaded
  • 12,000+ New posts in Tumblr
  • 800+ Reads on Scribd
  • 200,000+ minutes of voice calls on Skype
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Turn a Lighter Into a Mini Bike

09:12 Kalyan Gupta 0 Comments


Turn a Lighter Into a Mini Bike


Turn a Lighter Into a Mini Bike

We don’t know how we missed this awesome DIY lighter bike .
The pictures were originally posted on reddit without any additional instructions, so it may require some patience if you try to build this mini motorcycle yourself. Let us know how it goes!
 via:[boredpanda]
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RISE OF THE MOLECULAR MACHINES

08:44 Kalyan Gupta 0 Comments


Rise of the molecular machines


RISE OF THE MOLECULAR MACHINES


Chemists are putting molecules to work in ways only limited by our imagination 


Josh Howgego

Artist's impression of molecular machines at work
Our bodies are full of molecular machines and their synthetic counterparts may soon be all around us too

© SCIENCE PHOTO LIBRARY
As I extend an arm to pick up my cup of coffee there is an army of miniature machines operating inside my bicep. But what is it that makes the biomolecules in a muscle organise themselves into a powerful instrument, whilst the collections of atoms swilling around inside my cup are inanimate?

Nuts and bolts 

Mastering and mimicking how molecular machines work has been a fascinating adventure for chemists, and one in which their creativity has been unleashed. The parts that make up the tiny world of molecular machines are described using familiar terms: an alkyl chain might be called a piston, for example, or a benzene ring a wheel. But before these tiny machines could be built, an in depth knowledge of how to hold the component pieces together was needed.
Instead of nuts and bolts, molecular machines are held together by intermolecular forces; the subtle electrostatic attractions and repulsions between molecules. Chemistry is inherently dynamic, so these forces can hold molecules together strongly, but also enforce softer attractions, which pull molecules together, but still allow some degree of movement (see table.1 And it is these softer interactions that are key to many molecular machines. 
Intermolecular forces explained
Intermolecular forces explained. Download the pdf at the end of the article to see a high resolution version of this image.
Indeed one of the main steps towards the first molecular machine was working out how to mechanically interlock two molecules, whilst still allowing them freedom to move; a bit like having a ring slide along a piece of string. This problem was pondered for a long time, until the 1990s when several developments converged and made it possible.  

A molecular shuttle 

Fraser Stoddart, a chemist at Northwestern University, US, produced one of the early prototype molecular machines in 1994 (fig?1).2 The machine has a track with two stations and a shuttle that can slide along between them. The shuttle can't escape from the end of the track because there are bulky stopper groups at both ends which it can't fit over. 
Stoddart's molecular shuttle - chemical structures
Fig 1 - The key parts of Stoddart's molecular shuttle are the two stations (blue), the shuttle (orange) and the bulky stoppers (green)
The intermolecular forces that exist between the shuttle and the different points on the track determine where it sits. Because the shuttle is made from non-polar, aromatic building blocks, the Pi-Pi stacking intermolecular forces between it and the aromatic ring-based stations are quite strong. The forces between the shuttle and the track made of polyether chains are much weaker, as there are no aromatic moieties to stack against. 
Under normal conditions the shuttle doesn't have much preference between the two stations, so it is free to move rapidly over the polyether chain and between the two ports. However, the machine is cleverly designed to change its properties under different conditions. The nitrogen atoms in the first station are basic. That is, they are easily able to accept a hydrogen ion (proton) on exposure to acid. In the process the first station gains a positive charge. This repels the shuttle (which also has a positive charge), and so the shuttle is pushed to the second station. 
What the chemists had made was essentially a switch. With the addition of a little acid, their machine switched from freely moving between both states to being confined at a single station. 

Molecular muscles 

Diagram of a protein-based machine
Fig 2 - The actin and myosin filaments in muscles use protein-based machines to pull past each other
It is hoped that machines like Stoddart's will eventually function like the actin and myosin filaments that drive arms and legs (fig?2). Myosin fibre has protein-based molecular machines which skull along the surface of actin like a rowing boat gliding over water. Molecular machines might one day act as artificial muscles, powering robots or prosthetic limbs. 
The ability to emulate the molecular machines which power logistics operations in living systems is also desirable. Before mitosis, chromosomes need to be copied, and then each set must be transported to opposite ends of their cell. The biological solution is a network of microscopic fibres called microtubules strung across a cell's diameter, and kinesin (a motor protein) that can move along these rails. The kinesin hitches up its chromosone cargo, and hauls it across the cell.
But so far molecular machines have been employed most successfully as information storage media (the 'freely moving' and 'stuck' modes of the shuttle can be interpreted as a digital readout: off or on; 0 or 1). In contrast, the challenge of making artificial muscles or kinesin mimics is hard because one molecular machine on its own is too weak to be useful. Transferring controlled motion from a single interlocked molecule to a complex system - where lots of shuttles work together - has proved difficult.
Some prototype molecular machines have been developed, however, which - although drastically simplified - work similarly to the actin and myosin in muscles. But these don't use intermolecular forces in the same way as Stoddart's shuttle. One model machine, developed by chemist David Leigh, at the University of Edinburgh, UK, instead works by sequentially making and breaking different types of covalent chemical bonds.3
Leigh's molecular walker - chemical structures
Fig 3 - Leigh's molecular walker can take steps along a pathway of alternating functional groups
The first part of the design is a walker (red in fig?3), with two different functional groups at either end: one thiol (-SH) and one amide (-CONH). The walker unit is connected to a track of benzene rings, each topped with either a thiol (the blue units), or an aldehyde (the green ones).  
Like Stoddart's machine, the impetus for the walker's motion comes from varying the nature of the solution surrounding the molecules from acidic to basic. To start the walker off, Leigh uses acidic conditions. This fixes the disulfide (S-S) linkage in place, but means the imide (N-N) bond is under equilibrium; it is constantly breaking and re-forming. When the imine bond is broken, the walker can pivot on its disulfide foot, and the imine foot is free to either re-form the bond with foothold 1  or move forwards to form a new bond with the aldehyde moiety at foothold 3  . (Importantly, the walker unit must be attached by at least one 'foot' at all times. It couldn't run or jump, as with both linkages broken the walker would drift off into solution). 
By increasing the pH of the solution, the walker is switched from having its disulfide foot fixed to the track to having the imine foot held down. The basic conditions mean that the disulphide bond is under equilibrium this time, and now it can move around. 
Nature generally uses non-covalent interactions to stick the feet of its protein machines to their tracks. So although Leigh's model walker is not strictly biomimetic, it is an ingeniously simple way of achieving
much the same outcome as cellular transporting machines. 
In the future, walkers operating on extended tracks could be made. And in theory it should be possible to attach cargo to a walker. This would make an excellent analogue of the chromosone-transporting kinesin protein. 

Making nanocars 

Feringa's molecular rotor
Fig 4 - Feringa's molecular rotor is powered by electrons, which excite the double bond and induce an E/Z-isomerisation
As Leigh's molecular walker demonstrates, it is often easier to use covalently bonded molecules to make molecular machines. Despite how well non-covalent forces are understood in theory, it remains challenging and fiddly to deploy them in real, working examples. 
Perhaps that is why Ben Feringa, a chemist working at the University of Groningen in the Netherlands, also steered clear of them. His interest lay in making machines that produce rotary, rather than linear, motion. His rotary motor (fig 4) is composed of a single part, allowing him to avoid sticking axles and levers together using intermolecular forces. 
Feringa recently combined four of his rotary motors with a chassis to develop what he called a four-wheeled molecule (but everyone else likes to call a nanocar).4 In order for the car to drive along a surface, the paddle-like rotors must turn. The surface the car travels along is a metal, with electricity running through it. The electrons excite the rotor's double bond and induce an E/Z  -isomerisation. The steric strain then leads to a helix inversion, and the molecule flips over, producing rotational motion and powering the car forwards (fig?5). 
A nanocar using four molecular rotors
Fig 5 - If the four rotors work in unison, the nanocar begins to drive along the surface
Today, molecular machines that can perform an increasingly varied range of tasks are still being constructed. Chemists have succeeded in replicating the sorts of machines nature uses in our bodies with artificial systems in single interlocked systems. These machines are truly biomimetic: they operate using the same principles that nature has used since its inception. Impressive, given that it took many millennia for them to evolve in the first place. 
The Nobel prize winning scientist Richard Feynman talked about molecular machines in 1959, when people had just begun to imagine what they might be like. 'What would be the utility of such machines?' he said. 'Who knows? I cannot see exactly what would happen, but I can hardly doubt that when we have some control over the arrangement of things on a molecular scale we will get an enormously greater range of possible properties that substances can have, and of the different things we can do.' 
What exactly the legacy of molecular machines will be still remains to be seen, but with molecular shuttles and nanocars already behind us, we can safely agree with Feynman that the possibilities are exciting. 
Josh Howgego is a science writer and chemistry PhD student based in Bristol, UK 

References

1 Bond strengths are taken from: J W Steed and J L Atwood, Supramolecular chemistry,  Wiley, 2000; M Nishio et al, CrystEngComm., 2009, 11, 1757 (DOI:10.1039/b902318f)
2 R A Bissell et al, Nature, 1994, 369, 133 (DOI:?10.1038/369133a0)
3 M von Delius, E M Geertsema and D A Leigh, Nat. Chem., 2010, 2, 96 (DOI:?10.1038/nchem.481)
4  T Kudernac et al, Nature, 2011, 479, 208 (DOI:?10.1038/nature10587)
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AIST to Exhibit Fuel Cell as Small as Sugar Cube

08:35 Kalyan Gupta 0 Comments


AIST to Exhibit Fuel Cell as Small as Sugar Cube

The National Institute of Advanced Industrial Science and Technology (AIST) developed an extremely small SOFC (solid-oxide fuel cell) that is operable at 550°C.
The size of the cylindrical cell was substantially downsized so as to increase the ratio of electrode area to volume. Despite the small size, the fuel cell features high power output.

Twenty five needle-like modules, each with a diameter of 0.8mm, are integrated to form a sugar cube-sized SOFC that can generate 3W of electricity (Fig 1). In another method, cells can be fit into an extrusion-molded honeycomb with a density of more than 250 cells/cm2 (Fig 2).
The product is intended for cogeneration applications and automotive APUs (auxiliary power unit). It will be exhibited in the NEDO's booth at the nano tech 2009 International Nanotechnology Exhibition and Conference, which will take place at Tokyo Big Site from Feb 18 to 20, 2009.
Compared with other fuel cells, SOFCs are characterized by their high efficiency. And they are appropriate for power generation and cogeneration. However, existing SOFCs are vulnerable to load change because of their high operating temperature ranging from 700 to 1,000°C. Therefore, PEFCs (polymer electrolyte fuel cell) have been believed to be superior to SOFCs for automotive use.
The prototyped module is so small that its heat capacity is low, resulting in low operating temperature. Also, the absolute value of thermal expansion is low, which means less thermal shock and quick activation.
It is actually activated in about five minutes, but "we feel that it is possible to activate it in less than a minute," said Masanobu Awano, group leader of the Functional Assembly Technology Group at the Advanced Manufacturing Research Institute of AIST.
At present, the fuel cell is intended for use by automotive APUs, whose load change is small But it can be used to provide power to fuel-cell vehicles if technology for effectively connecting multiple modules is established, according to AIST.

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NANO-BREAKTHROUGH FOR AUTOMOTIVE FUEL CELLS ?

08:32 Kalyan Gupta 0 Comments


NANO-BREAKTHROUGH FOR AUTOMOTIVE FUEL CELLS ?
What if by some engineering miracle one part within a conventional internal combustion engine was changed that would multiply its power output by a factor of 5 without burning additional fuel? A 100 horsepower engine would suddenly put out 500. The world would change. Engines would be smaller, lighter and presumably somewhat less expensive.
Unfortunately this miracle hasn’t happened. But it MAY have for proton exchange membrane (PEM) fuel cells. (I emphasize the “may” because the breakthrough technology doesn’t appear to have been tested in a working, off-the-shelf, fuel cell.)
There’s one part within a fuel cell that literally makes it all come together. Appropriately named it’s the catalyst. The catalyst creates the opportunity for hydrogen to combine with oxygen to make water, and while doing so momentarily allows electrons to be borrowed as flowing electric current to do real work, like turning an electric motor to drive a car to the supermarket.
Catalysts are typically made of pricey platinum (but not very much of it) adding to the cost of fuel cells and encumbering their mass adoption into vehicles and other portable uses.
Hitachi Maxell, of Tokyo, thinks it has a new catalyst solution that would be a true breakthrough if it works in the real fuel cell world. The catalyst not only uses less platinum but dramatically increases electric current producing reactions by almost that factor of five eluded to above: It encourages 4.8 times the hydrogen-oxygen combinations than a typical commercial platinum catalyst of the same unit area. The more hydrogen and oxygen combinations a catalyst can encourage the more electrons will be available for use as flowing electricity.
Hitachi Maxell, better known as Maxell, has increased those combinations by increasing the reactive surface area of the catalyst using nanosized particles of gold and platinum. (Sure, gold is pricey but its not as bad as platinum.) Nanomaterials have that wondrous capability of increasing an object’s surface area without increasing its physical dimensions.
In technical speak, Hitachi Maxell says the new gold-platinum (AuPt) catalyst is made up of nano-particles 2 to 3 nanometers in size. In the high-activity catalyst structure gold and platinum are not fully alloyed (they still remain mostly separate metals) thus allowing high oxygen-reduction reaction activity.
In street speak the dramatically more reactive catalyst means each fuel cell, and a whole stack of them, can be significantly smaller for the same electrical power output. Smaller means less materials needed for the whole fuel cell, including less quantities of gold and platinum, equating to a less expensive fuel cell. Smaller also means less weight. Smaller, too, may also mean that less hydrogen needs to be carried on board, or looking at it in another way the same amount of hydrogen now used in fuel cell vehicles would allow for longer range between refuelings - a more fuel efficient fuel cell because of the Maxell catalyst.
Maxell says this success represents a large step closer to fuel cells that are practical for applications requiring large electric current, such as automobiles and homes.
We’ll have to see however. Fuel cell developers will have to get some of the new material and try it out in a working fuel cell.
Hitachi Maxell, founded in 1960, is best known for products sold in office supply outlets. The company is a leading manufacturer of information storage media products including magnetic tapes, optical disks, and battery products including lithium ion rechargeable batteries, micro batteries and dry cell batteries.

Links:
Hitachi Maxell
http://www.maxell.com
For more detail and graph.
http://www.maxell.co.jp/e/release/20080327.html
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Big Thinking: The Power of Nanoscience

02:41 Kalyan Gupta 0 Comments


Big Thinking: The Power of Nanoscience



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Nano Science, Fact or Fiction?

02:39 Kalyan Gupta 0 Comments


Nano Science, Fact or Fiction?





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Nanotech Mobile

02:34 Kalyan Gupta 0 Comments


Nokia and Cambridge Design Nanotech Mobile

Posted by Geek
morphy 123x100 Nokia and Cambridge Design Nanotech MobileNokia may not be too funky with their mobile phone designs for mass production but you have to admit, their concept designs are something that look, quite literally, out of this world. Morph, a joint Nanotechnology concept, developed by Nokia Research Center (NRC) and the University of Cambridge (UK) – was launched today alongside the “Design and the Elastic Mind” exhibition, at The Museum of Modern Art (MoMA) in New York. Morph features in both the exhibition catalog and on MoMA’s official website.
img 50231 main 550x412 Nokia and Cambridge Design Nanotech Mobile
Morph is a concept that demonstrates how future mobile devices might be stretchable and flexible, allowing the user to transform their mobile device into radically different shapes. It demonstrates the ultimate functionality that nanotechnology might be capable of delivering: flexible materials, transparent electronics and self-cleaning surfaces. Dr. Bob Iannucci, Chief Technology Officer, Nokia, commented: “Nokia Research Center is looking at ways to reinvent the form and function of mobile devices; the Morph concept shows what might be possible”.
Dr. Tapani Ryhanen, Head of the NRC Cambridge UK laboratory, Nokia, commented: “We hope that this combination of art and science will showcase the potential of nanoscience to a wider audience.”
img 50241 angles 550x412 Nokia and Cambridge Design Nanotech Mobile
The partnership between Nokia and the University of Cambridge was announced in March, 2007 – an agreement to work together on an extensive and long-term programme of joint research projects. NRC together with the University of Cambridge have decided to work on more projects that, to begin with, are centered on nanotechnology.
Elements of Morph might be available to integrate into handheld devices within 7 years, though initially only at the high-end. However, nanotechnology may one day lead to low cost manufacturing solutions, and offers the possibility of integrating complex functionality at a low price. Hopefully it won’t take that long.

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Magnetic Fluids and Magnetic Media Processing Methods and Applications that Use Nanomaterials

09:21 Kalyan Gupta 0 Comments


Magnetic Fluids and Magnetic Media Processing Methods and Applications that Use Nanomaterials, Supplier Data by Strem Chemicals



Background

Since its inception, Strem has focused on offering unique organometallic compounds for both academic and industrial research purposes. Close relationships with leading researchers in the field have enabled Strem to stay abreast of the latest scientific advances in and regularly add novel chemicals to our product portfolio. Most recently, Strem has embraced the emerging area of nanotechnology and formed a collaboration with the Max-Planck-Institut fuer Kohlenforschung. A series of nanomaterials, including including metal nanoclusters, metal nanocolloids (organosols and hydrosols), metal nanopowders, metal nanoparticles, and magnetic fluids are now available from Strem. Below is a discussion of potential applications for magnetic fluids.

Magnetic Fluids

Magnetic fluids or ferrofluids are stable colloidal suspensions of magnetic metal nanoparticles in a carrier liquid. To maintain suspension, the particles are coated with a surface active layer. The carrier liquid can be a hydrocarbon, ester, perfluorether, water, etc. Properties of nanomagnetic particles, films and bulk materials include exchange coupling, tunneling magnetoresistance, giant magnetoresistance, single domain behavior, and superparamagnetism. Magnetite based magnetic fluids do not have sufficient magnetic properties for many applications. Colloidal nanosized metallic Fe, Co or Fe/Co alloys like those offered by Strem do posses ideal properties.

Separations

Magnetic fluids are attractive in separation applications because the reactivity of the particles can be tailored by modifying their surface coatings, they afford very high surface areas without the use of porous absorbents, and they can be recovered for reuse.

Using Magnetic Nanoparticles in Nanocatalysts - Processing Methods and Benefits

Nanocatalysts containing magnetic nanoparticles are being developed. Silica and carbon are utilized to maintain the stability of the nanoparticles under reaction conditions. Functionalized surfaces on the nanoparticles include immobilizing sites for catalytically active species such as nanometal particles, enzymes, and homogenous catalysts. The catalysts are easily separated by utilizing the magnetic interaction between the magnetic nanoparticle and an external applied magnetic field. These hybrid catalysts offer the advantages of homogeneous and heterogeneous catalysis combined

Using Magnetic Nanomaterials in Filters and to Remove Sulfur Compounds from Hydrocarbon Fuels

Magnetic nanomaterials have also been used in filters to remove selected impurities from various types of fluids. The separation of organic contaminants such as polyaromatic hydrocarbons from water and the removal of sulfur compounds from hydrocarbon fuels, are also being investigated with magnetic fluids.

Current Research into Biochemical Reactions Using Magnetic Nanoparticles

In biochemical reactions, magnetic nanoparticles are being investigated as a means to aid in the separation and recovery of target biomolecules such as DNA, RNA, and proteins. Non-ferrous metals can be rapidly recovered from solid wastes using sink-float separation, which utilized the magnetic fluid as a coating on the materials. Metals of different densities can be separated by controlling the field gradient, which levitates the materials.
Figure 1. Separation using magnetic nanoparticles.

Magnetic Media

Magnetic nanoparticles have significant potential for increasing magnetic storage capabilities. Cobalt and Pt/Co bimetallic nanoparticles are being investigated as magnetic storage devices. Researchers are studying core-shell cobalt nanoparticles embedded in an anti-ferromagnetic matrix. Cobalt nanoparticles have also been found to self-assemble into ‘nanorings’ that can store magnetic information at room temperature. These magnetic rings are being considered as memory elements in devices for long-term data storage and magnetic random-access memory (MRAM).
AZoNano, Nanotechnology - This diagram shows a magnetic hard disk and the schematic illustration of the recorded bits supported by an array of ferromagnetic dots.
Figure 2. A magnetic hard disk and the schematic illustration of the recorded bits supported by an array of ferromagnetic dots.

How Magnetic Cobalt Nanocrystals Can Improve Magnetic Random-Access Memory (MRAM) Systems

MRAM systems are currently severely under-damped systems. Just a few monolayers of magnetic cobalt nanocrystals deposited on the surface of the magnetic layer in an MRAM device have been found to provide a tripling of the dampening effect. In addition, a 2-2-3 fold enhancement of the magnetic field can be achieved in an MRAM device when a superparamagnetic nanoparticle layer is used in place of the continuous liner. As a result, a third of the current can be used to obtain the same magnetic field as before. Alternatively, the same amount of current can be used to obtain a much more thermally stable system.

Industry Applications for Polystyrene Films Containing Gold Nanoparticles

Polystyrene films containing gold nanoparticles have been found to store a charge and act as organic memory devices. The polystyrene base, which is carried in a liquid, can be applied through spray, paint, or print technology. 3-D arrays can also be constructed for high density storage and could have applications in digital memory chips for computers, digital cameras, and cell phones. The goal of other researchers is to have each nanomagnetic particle support one bit of digital information.

Industrial Applications for Magnetic Fluids

Industrial applications for magnetic fluids include seals, dampers, and moving coil loud speakers. In seals, the ferrofluid acts as a magnetic O-ring and provides hermetic sealing with zero leakage. Because the fluid is also lubricating, minimal wear occurs as well. Seals based on magnetic fluids have been developed for vacuum systems, gas-air media, and liquids (water, oil, and chemically active media). They find use in high speed computer disk drives, rotating joints in clean rooms, and in industrial applications where control of volatile emissions and protection of sensitive environments is important.

Using Magnetic Fluids as Dampers - Processing Methods

Magnetic fluids can change their apparent viscosity in proportion to the strength of an applied magnetic field. Therefore, the viscosity can be controlled dynamically, which allows for active damping. Large amounts of mechanical power can be controlled with a small amount of electrical power, making this method of vibration control much more efficient than traditional systems. It is possible to adjust the stiffness thousands of times per second. As dampers, magnetic fluids are highly efficient over a wide frequency and temperature range. They are used to dampen automotive devices, space structures, wing oscillations in aircraft, protect devices and some buildings from vibrational damage, and to improve comfort during transport.

Using Magnetic Fluids in Moving Coil Loudspeakers - Processes and Benefits

In a moving coil loudspeaker, the magnetic fluid conducts heat away from the voice coil, keeps the voice coil concentric with the magnet, and passively dampens movement of the cone. The magnetic fluid is placed in what is normally the air gap around the voice coil. Advantages of using magnetic fluids in moving coil loudspeakers include increased power handling, a smooth frequency response curve, and reduced distortion.

AZoNano, Nanotechnology - Diagram showing the role played by magnetic fluids in a ??

Figure 3. Diagram of a moving coil loudspeaker.

List of Nanomaterials that Strem Chemicals Can Supply to All Types of Industry

Numerous other potential applications exist for magnetic nanomaterials from Strem. Areas currently under investigation include non-destructive testing, finishing polishing, domain observation, telecommunications, magnetic inks, robotics, automotive, surface analysis, and medical/pharmaceutical such as targeted drug delivery, diagnostics, and biosensors. A listing of specific including metal nanoclusters, metal nanocolloids (organosols and hydrosols), metal nanopowders, metal nanoparticles, and magnetic fluids offered by Strem is available upon request or via our website. Application sheets discussing the potential use of these products in the medical and pharmaceutical, defense and security, chemical, automotive, and energy fields, and as magnetic fluids, can also be obtained from Strem. More information is also available in the form of a reference sheet listing literature source materials.
Source: Strem Chemicals.
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