Amazing Science
Follow
Find tag "nanotech"
380.6K views | +69 today
Your new post is loading...
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Nanotubes used to create smallest ever hologram

Nanotubes used to create smallest ever hologram | Amazing Science | Scoop.it


Scientists from Cambridge UK have generated holograms from carbon nanotubes for the first time, which could lead to much sharper holograms with a vastly increased field of view.

 

The researchers from the University’s Centre of Molecular Materials for Photonics and Electronics (CMMPE) have harnessed the extraordinary conductive and light scattering abilities of these tubes – made from several sheets of carbon atoms rolled into a cylinder – to diffract high resolution holograms. Carbon nanotubes are one billionth of a metre wide, only a few nanometres, and the scientists have used them as the smallest ever scattering elements to create a static holographic projection of the word CAMBRIDGE.

 

Many scientists believe that carbon nanotubes will be at the heart of future industry and human endeavour, with anticipated impact on everything from solar cells to cancer treatments, as well as optical imaging. One of their most astonishing features is strength – about 100 times stronger than steel at one-sixth the weight.

 

The work on using these nanotubes to project holograms, the 2D images that optically render as three-dimensional.

 

The multi-walled nanotubes used for this work are around 700 times thinner than a human hair, and grown vertically on a layer of silicon in the manner of atomic chimney stacks. The researchers were able to calculate a placement pattern that expressed the name of this institution using various colours of laser light – all channelled out (scattered) from the nano-scale structures.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Drug efficacy boost by using nanoparticles to target mitochondria

Drug efficacy boost by using nanoparticles to target mitochondria | Amazing Science | Scoop.it

Nanoparticles have shown great promise in the targeted delivery of drugs to cells, but researchers at the University of Georgia have refined the drug delivery process further by using nanoparticles to deliver drugs to a specific organelle within cells.

 

Dhar and her co-author, doctoral student Sean Marrache, used a biodegradable, FDA-approved polymer to fabricate their nanoparticles and then used the particles to encapsulate and test drugs that treat a variety of conditions. To test the effectiveness of their drug targeting system against cancer, they encapsulated the drug lonidamine, which works by inhibiting energy production in the mitochondria, and, separately, a form of the antioxidant vitamin E. They then treated cultured cancer cells and found that mitochondrial targeting increased the effectiveness of the drugs by more than 100 times when compared to the drugs alone and by five times when compared to the delivery of drugs with nanoparticles that target the outside of cells.

 

Similarly, the compound curcumin has shown promise in inhibiting formation of the amyloid plaques that are a hallmark of Alzheimer's disease, but it quickly degrades in the presence of light and is broken down rapidly by the body. By encapsulating curcumin in the mitochondria-targeting nanoparticles, however, the researchers were able to restore the ability of brain cells in culture to survive despite the presence of a compound that encourages plaque formation. Nearly 100 percent of the cells treated with the mitochondria-targeting nanoparticles survived in the presence of the plaque-inducing compound, compared to 67 percent of cells treated with free curcumin and 70 percent of cells treated with nanoparticles that target the outside of cells.

 

Finally, the researchers encapsulated the obesity drug 2,4-DNP—which works by making energy production in the mitochondria less efficient—in their nanoparticles and found that it reduced the production of fat by cultured cells known as preadipocytes by 67 percent compared to cells treated with the drug alone and by 61 percent of cells treated with nanoparticles that target the outside of cells.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Nanostructured thermoelectric material breaks record for turning heat into electricity

Nanostructured thermoelectric material breaks record for turning heat into electricity | Amazing Science | Scoop.it

A scrambled-up material has broken the record for converting heat into electricity. Disorder may be the key to creating a new generation of energy-harvesting technologies. Laptop owners and car mechanics alike know that heat is a major by-product of any kind of work. In power stations, for example, only one-third of the energy that goes into the generator comes out as electricity — the rest radiates away as 'waste heat' before it can turn a turbine.

 

Kanatzidis and his team began with one of the most well-known thermoelectrics: lead telluride (PbTe), which usually has an ordered lattice structure. The researchers scattered in a few sodium atoms to boost the material's electrical conductivity, then shoved in some nanocrystals of strontium telluride (SrTe), another thermoelectric material. The crystals allowed electrons to pass, but disrupted the flow of heat at short scales, preserving the temperature gradient.

 

The final step was to stop heat flow over longer scales. To do this, the team created a fractured version of their pretty thermoelectric crystal. The fracturing did the trick: the cracks allowed electrons to move but reflected heat vibrations in the crystal. The material had a conversion efficiency of about 15% — double that of normal PbTe thermoelectrics.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Uniqueness, Advantages, Challenges, Solutions, and Perspectives in Therapeutics Applying RNA Nanotechnology

Uniqueness, Advantages, Challenges, Solutions, and Perspectives in Therapeutics Applying RNA Nanotechnology | Amazing Science | Scoop.it

Nanotechnology is a rapidly evolving field that encompasses the fabrication and application of materials at the nanometer scale using either top-down approaches or bottom-up assembly. In the biological world, a large number of highly ordered structures and nanomachines made up of macromolecules have evolved to perform many diverse biological functions. Their intriguing configurations have inspired many biomimetic designs. DNA, RNA, and proteins have unique intrinsic characteristics at the nanometer scale and therefore can serve as the building blocks for the bottom-up design and construction of nano scale structures and devices. Seeman pioneered the concept 30 years ago of using DNA as a material for creating nanostructures; this has led to an explosion of knowledge in the now well-established field of DNA nanotechnology. The potential of using peptides and proteins for nanotechnological applications has also been extensively explored. Recently, RNA molecules have become increasingly attractive. The field of RNA nanotechnology is rapidly emerging. RNA can be manipulated with the simplicity characteristic of DNA to produce nanoparticles with a diversity of quaternary structures by self-assembly. Additionally RNA is tremendously versatile in its function and some RNA molecules display catalytic activities much like proteins. Thus, RNA has the advantage of both worlds. However, the instability of RNA has made many scientists flinch away from RNA nanotechnology. Other concerns that have deterred the progress of RNA therapeutics include the induction of interferons, stimulation of cytokines, and activation of other immune systems, as well as short pharmacokinetic profiles in vivo. This review will provide some solutions and perspectives on the chemical and thermodynamic stability, in vivo half-life and biodistribution, yield and production cost, in vivo toxicity and side effect, specific delivery and targeting, as well as endosomal trapping and escape.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Blurring the boundary between biology and machines - light-activated skeletal muscle for robots

Blurring the boundary between biology and machines - light-activated skeletal muscle for robots | Amazing Science | Scoop.it

Many robotic designs take nature as their muse: sticking to walls like geckos, swimming through water like tuna, sprinting across terrain like cheetahs. Such designs borrow properties from nature, using engineered materials and hardware to mimic animals’ behavior.

 

Scientists at MIT and the University of Pennsylvania have genetically engineered muscle cells to flex in response to light, and are using the light-sensitive tissue to build highly articulated robots. This “bio-integrated” approach, as they call it, may one day enable robotic animals that move with the strength and flexibility of their living counterparts.

 

The group’s design effectively blurs the boundary between nature and machines, says Harry Asada, the Ford Professor of Engineering in MIT’s Department of Mechanical Engineering.

 

“With bio-inspired designs, biology is a metaphor, and robotics is the tool to make it happen,” says Asada, who is a co-author on the paper. “With bio-integrated designs, biology provides the materials, not just the metaphor. This is a new direction we’re pushing in biorobotics.”

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

3D Photografting: Laser beam used as 3D painting tool to grow biological tissue or to create micro sensors

3D Photografting: Laser beam used as 3D painting tool to grow biological tissue or to create micro sensors | Amazing Science | Scoop.it
With laser beams, molecules can be fixed at exactly the right position in a three dimensional material. The new method can be used to grow biological tissue or to create micro sensors.

 

"3-D-photografting" is the name of the new method. Two research teams from the Vienna University of Technology collaborated closely to develop it: Professor Jürgen Stampfl's materials science team and Professor Robert Liska's research group for macromolecular chemistry. Both research groups have already attracted considerable attention in the past, developing new kinds of 3-D-printers.

 

When biological tissue is grown, this method can allow the positioning of chemical signals, telling living cells where to attach. The new technique also holds promise for sensor technology: A tiny three dimensional "lab on a chip" could be created, in which accurately positioned molecules react with substances from the environment. The scientists start with a so-called hydrogel -- a material made of macromolecules, arranged in a loose meshwork. Between those molecules, large pores remain, through which other molecules or even cells can migrate. Specially selected molecules are introduced into the hydrogel meshwork, then certain points are irradiated with a laser beam. At the positions where the focused laser beam is most intense, a photochemically labile bond is broken. That way, highly reactive intermediates are created which locally attach to the hydrogel very quickly. The precision depends on the laser's lens system, at the Vienna University of Technology a resolution of 4 µm could be obtained.

 

Depending on the application, different molecules can be used. 3-D photografting is not only useful for bio-engineering but also for other fields, such as photovoltaics or sensor technology. In a very small space, molecules can be positioned which attach to specific chemical substances and allow their detection. A microscopic three-dimensional "lab on a chip" becomes possible.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

A ‘Google’ for chemistry invents best path to new compounds in seconds

A ‘Google’ for chemistry invents best path to new compounds in seconds | Amazing Science | Scoop.it

Giantic network links all known compounds and reactions together. 

 

Northwestern University scientists have connected 250 years of organic chemical knowledge into one giant computer network called Chematica — a chemical “Google” on steroids.

 

A decade in the making, the software optimizes syntheses of drug molecules and other important compounds, combines long (and expensive) syntheses of compounds into shorter and more economical routes, and identifies suspicious chemical recipes that could lead to chemical weapons.

 

The number of possible synthetic pathways leading to the desired target of a synthesis can be astronomical (10E19 pathways within five synthetic steps).

 

The Chematica network comprises some seven million chemicals connected by a similar number of reactions. A family of algorithms that searches and analyzes the network allows the chemist at his or her computer to easily tap into this vast compendium of chemical knowledge. And the system learns from experience, as more data and algorithms are added to its knowledge base.

more...
Ramanathan's curator insight, August 9, 12:00 AM

New compounds

Scooped by Dr. Stefan Gruenwald
Scoop.it!

Batteries made from world’s thinnest material could power tomorrow’s electric cars

Batteries made from world’s thinnest material could power tomorrow’s electric cars | Amazing Science | Scoop.it

Engineering researchers at Rensselaer Polytechnic Institute made a sheet of paper from the world's thinnest material, graphene, and then zapped the paper with a laser or camera flash to blemish it with countless cracks, pores, and other imperfections. The result is a graphene anode material that can be charged or discharged 10 times faster than conventional graphite anodes used in today's lithium (Li)-ion batteries for today’s mobile phones, laptop and tablet computers, and even electric automobiles. The intentional imperfections are critical for the device’s ability to quickly accept or discharge large amounts of energy. As seen in this photo, the graphene paper displays both structural rigidity and integrity.

 

The research team started investigating graphene as a possible replacement for the graphite used as the anode material in today's Li-ion batteries. Essentially a single layer of the graphite found commonly in our pencils or the charcoal we burn on our barbeques, graphene is an atom-thick sheet of carbon atoms arranged like a nanoscale chicken-wire fence. In previous studies, Li-ion batteries with graphite anodes exhibited good energy density but low power density, meaning they could not charge or discharge quickly. This slow charging and discharging was because lithium ions could only physically enter or exit the battery's graphite anode from the edges, and slowly work their way across the length of the individual layers of graphene.

 

The solution was to use a known technique to create a large sheet of graphene oxide paper. This paper is about the thickness of a piece of everyday printer paper, and can be made nearly any size or shape. The research team then exposed some of the graphene oxide paper to a laser, and other samples of the paper were exposed to a simple flash from a digital camera. In both instances, the heat from the laser or photoflash literally caused mini-explosions throughout the paper, as the oxygen atoms in graphene oxide were violently expelled from the structure. The aftermath of this oxygen exodus was sheets of graphene pockmarked with countless cracks, pores, voids, and other blemishes. The pressure created by the escaping oxygen also prompted the graphene paper to expand five-fold in thickness, creating large voids between the individual graphene sheets.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Entropy can lead to order, paving the route to nanostructures

Entropy can lead to order, paving the route to nanostructures | Amazing Science | Scoop.it

Researchers trying to herd tiny particles into useful ordered formations have found an unlikely ally: entropy, a tendency generally described as "disorder." Shapes can arrange themselves into crystal structures through entropy alone, new research from the University of Michigan shows.

 

Computer simulations by University of Michigan scientists and engineers show that the property can nudge particles to form organized structures. By analyzing the shapes of the particles beforehand, they can even predict what kinds of structures will form.

 

Physicist and chemical engineering professor Sharon Glotzer proposes that such materials could be designed by working backward from the desired properties to generate a blueprint. That design can then be realized with nanoparticles -- particles a thousand times smaller than the width of a human hair that can combine in ways that would be impossible through ordinary chemistry alone. One of the major challenges is persuading the nanoparticles to create the intended structures, but recent studies by Glotzer's group and others showed that some simple particle shapes do so spontaneously as the particles are crowded together.

 

"We studied 145 different shapes, and that gave us more data than anyone has ever had on these types of potential crystal-formers," Glotzer SAID. "With so much information, we could begin to see just how many structures are possible from particle shape alone, and look for trends."

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Nanotechnology, material science, and photonic research gets boost from new 3-D visualization technology

Nanotechnology, material science, and photonic research gets boost from new 3-D visualization technology | Amazing Science | Scoop.it

For the first time, X-ray scientists have combined high-resolution imaging with 3-D viewing of the surface layer of material using X-ray vision in a way that does not damage the sample.

 

This new technique expands the range of X-ray research possible for biology and many aspects of nanotechnology, particularly nanofilms, photonics, and micro- and nano-electronics.

 

This new technique also reduces “guesswork” by eliminating the need for modeling-dependent structural simulation often used in X-ray analysis. Scientists from the Advanced Photon Source and Center for Nanoscale Materials at the U.S. Department of Energy’s (DOE) Argonne National Laboratory have blended the advantages of 3-D surface viewing from grazing-incident geometry scattering with the high-resolution capabilities of lensless X-ray coherent diffraction imaging (CDI).

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Silicon out - copper in: Researchers create solar panels from cheap copper oxide

Silicon out - copper in: Researchers create solar panels from cheap copper oxide | Amazing Science | Scoop.it

Researchers from the University of California and Berkeley Lab have discovered a way of making photovoltaic cells out of any semiconducting material, not just beautiful, expensive crystals of silicon. In principle, this could open the door to much cheaper solar power. 

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

A big step in a miniature world: Electrical charge and size of nano particles simultaneously measured

A big step in a miniature world: Electrical charge and size of nano particles simultaneously measured | Amazing Science | Scoop.it

Nano particles are a millionth of a millimeter in size, making them invisible to the human eye. Unless, that is, they are under the microscope of Prof. Madhavi Krishnan, a biophysicist at the University of Zurich. Prof. Krishnan has developed a new method that measures not only the size of the particles but also their electrostatic charge. Up until now it has not been possible to determine the charge of the particles directly. This unique method, which is the first of its kind in the world, is just as important for the manufacture of drugs as in basic research. The process has now been introduced for the first time.

 

It works like this: between two glass plates the size of a chip, the researchers create thousands of round energy holes. The trick is that these holes have just a weak electrostatic charge. The scientists than add a drop of the solution to the plates, whereupon each particle falls into an energy hole and remains trapped there. But the particles do not remain motionless in their trap. Instead, molecules in the solution collide with them continuously, causing the particles to move in a circular motion. For all solutions manufactured industrially, the electrical charge of the nano particles contained therein is also of primary interest, because it is the electrical charge that allows a fluid solution to remain stable and not to develop a lumpy consistency. A suspension is a fluid in which miniscule particles or drops are finely distributed, for example in milk, blood, various paints, cosmetics, vaccines and numerous pharmaceuticals. One example is the manufacture of medicines that have to be administered in precise doses over a longer period using drug-delivery systems. In this context, nano particles act as "packages" that transport the drugs to where they need to take effect. Very often, it is their electrical charge that allows them to pass through tissue and cell membranes in the body unobstructed and so to take effect. That's why it is so important to be able to measure their charge.

 

 

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Electronic sensor rivals sensitivity of human skin

Electronic sensor rivals sensitivity of human skin | Amazing Science | Scoop.it

A flexible electronic sensor made from interlocking hairs can detect the gentle steps of a ladybird and distinguish between shear and twisting forces, just as human skin can. It can also be strapped to the wrist and used as a heart-rate monitor.

 

The described device was inspired by beetle wings and could give robots a more nuanced sense of touch. When some beetles are resting, a row of hairs on their wings locks into an array of hairs on their body through a type of static attraction called van der Waals' forces. In Suh’s sensors, the 'hairs' are sheets of polymer fibres that are 100 nanometres in diameter and one micrometre long, and coated with metal to make them electrically conductive. When the sheets are sandwiched together, the nanohairs are attracted to one another and locked in, just like the beetle hairs. The device is then wired up so that an electrical current can be applied, and covered in a layer of soft, protective polymer.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Researchers demonstrate 'giant' forces in super-strong nanomaterials

Researchers demonstrate 'giant' forces in super-strong nanomaterials | Amazing Science | Scoop.it

In a study that could lead to advances in the emerging fields of optical computing and nanomaterials, researchers at Missouri University of Science and Technology report that a new class of nanoscale slot waveguides pack 100 to 1,000 times more transverse optical force than conventional silicon slot waveguides.

 

In a recent study, Gao and Yang describe the unusual optical and mechanical properties of nanometer-scale metal-dielectric structures called metamaterials. The researchers created computer simulations of nanometer-scale models of metamaterial slot waveguides, which are structures designed to channel beams of light from one area to another. Waveguides function like tiny filaments or the wires of an integrated circuit, but on a much smaller scale.

 

For their study, the Missouri S&T researchers simulated slot waveguides made of layered structures of a metal (in this case, silver) and a dielectric material (germanium), arranged like the alternating bread and meat in a club sandwich. A nanometer - visible only with the aid of a high-power electron microscope - is one billionth of a meter, and some nanomaterials are only a few atoms in size.

 

Gao and Yang simulated what would happen with modeled identical waveguides - each 40 nanometers wide and 30 nanometers tall - that were stacked with a tiny air gap between them. They then measured the transverse optical force between the two waveguides. Optical force refers to the way beams of light can be made to attract or repel each other, as magnets do. In their experiments on the simulated metamaterials, the Missouri S&T researchers found that "the transverse optical forces in slot waveguides of hyperbolic metamaterials can be over two orders of magnitude stronger than that in conventional dielectric slot waveguides.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

One step closer to creating self-assembling nanomaterials in space

One step closer to creating self-assembling nanomaterials in space | Amazing Science | Scoop.it

Imagine a computer chip that can assemble itself. Engineers and scientists are closer to making this and other scalable forms of nanotechnology a reality as a result of new milestones in using nanoparticles as self-assembling building blocks in functional materials, says professor Eric M. Furst at the University of Delaware.

 

The research team studied paramagnetic colloids while periodically applying an external magnetic field at different intervals. With just the right frequency and field strength, the team was able to watch the particles transition from a random, solid like material into highly organized crystalline structures or lattices.

 

According to Furst, a professor in UD’s Department of Chemical and Biomolecular Engineering, no one before has ever witnessed this guided “phase separation” of particles. “This development is exciting because it provides insight into how researchers can build organized structures, crystals of particles, using directing fields and it may prompt new discoveries into how we can get materials to organize themselves,” Furst said. Because gravity plays a role in how the particles assemble or disassemble, the research team studied the suspensions aboard the International Space Station (ISS) through collaborative efforts with NASA scientists and astronauts. One interesting observation, Furst reported, was how the structure formed by the particles slowly coarsened, then rapidly grew and separated — similar to the way oil and water separate when combined — before realigning into a crystalline structure.

 

Already, Furst’s lab has created novel nanomaterials for use in optical communications materials and thermal barrier coatings. This new detail, along with other recorded data about the process, will now enable scientists to discover other paths to manipulate and create new nanomaterials from nanoparticle building blocks.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

First All-optical Switch Out Of Cadmium Sulfide Nanowires

First All-optical Switch Out Of Cadmium Sulfide Nanowires | Amazing Science | Scoop.it

Computers may be getting faster every year, but those advances in computer speed could be dwarfed if their 1’s and 0’s were represented by bursts of light, instead of electricity. Researchers at the University of Pennsylvania have made an important advance in this frontier of photonics, fashioning the first all-optical photonic switch out of cadmium sulfide nanowires. Moreover, they combined these photonic switches into a logic gate, a fundamental component of computer chips that process information. The research team began by precisely cutting a gap into a nanowire. They then pumped enough energy into the first nanowire segment that it began to emit laser light from its end and through the gap. Because the researchers started with a single nanowire, the two segment ends were perfectly matched, allowing the second segment to efficiently absorb and transmit the light down its length. “Putting switches together lets you make logic gates, and assembling logic gates allows you to do computation,” Piccione said. “We used these optical switches to construct a NAND gate, which is a fundamental building block of modern computer processing.” “We see a future where ‘consumer electronics’ become ‘consumer photonics".

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Harnessing bacteria to turn gears

Harnessing bacteria to turn gears | Amazing Science | Scoop.it

A team of scientists from the Argonne National Laboratory and Northwestern University have figured out how to get bacteria to spin tiny gears. Though the gears themselves are small, the bacteria are even smaller, so apparently it takes hundreds of them swimming in swarms to produce enough energy to turn the gears. Anyone have ideas about how to turn these gear motions into logic gates?

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

First Ever: Weighing Individual Molecules One at a Time

First Ever: Weighing Individual Molecules One at a Time | Amazing Science | Scoop.it

A team led by scientists at the California Institute of Technology (Caltech) has made the first-ever mechanical device that can measure the mass of individual molecules one at a time.

 

This new technology, the researchers say, will eventually help doctors diagnose diseases, enable biologists to study viruses and probe the molecular machinery of cells, and even allow scientists to better measure nanoparticles and air pollution.

 

The device—which is only a couple millionths of a meter in size—consists of a tiny, vibrating bridge-like structure. When a particle or molecule lands on the bridge, its mass changes the oscillating frequency in a way that reveals how much the particle weighs.

 

The new instrument is based on a technique Roukes and his colleagues developed over the last 12 years. In work published in 2009, they showed that a bridge-like device—called a nanoelectromechanical system (NEMS) resonator—could indeed measure the masses of individual particles, which were sprayed onto the apparatus. The difficulty, however, was that the measured shifts in frequencies depended not only on the particle's actual mass, but also on where the particle landed. Without knowing the particle's landing site, the researchers had to analyze measurements of about 500 identical particles in order to pinpoint its mass. But with the new and improved technique, the scientists need only one single particle to make a measurement. The critical advance made in this current work is that it now allows us to weigh molecules—one by one—as they come in.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Merging biologics with electronics: Grow cyborg tissues with embedded nanoelectronics

Merging biologics with electronics: Grow cyborg tissues with embedded nanoelectronics | Amazing Science | Scoop.it
For the first time, Harvard scientists have created a type of cyborg tissue by embedding a three-dimensional network of functional, biocompatible, nanoscale wires into engineered human tissues.

 

The research addresses a concern that has long been associated with work on bioengineered tissue: how to create systems capable of sensing chemical or electrical changes in the tissue after it has been grown and implanted. The system might also represent a solution to researchers’ struggles in developing methods to directly stimulate engineered tissues and measure cellular reactions.

 

The process of building the networks is similar to that used to etch microchips. Beginning with a two-dimensional substrate, researchers laid out a mesh of organic polymer around nanoscale wires, which serve as the critical sensing elements. Nanoscale electrodes, which connect the nanowire elements, were then built within the mesh to enable nanowire transistors to measure the activity in cells without damaging them. Once completed, the substrate is then dissolved, leaving researchers with a netlike sponge, or a mesh, that can be folded or rolled into a host of three-dimensional shapes. Finally, the networks are porous enough to allow seeding them with cells and encourage those cells to grow in 3-D cultures.

 

Using heart and nerve cells, the Harvard research team successfully engineered tissues containing embedded nanoscale networks without affecting the cells’ viability or activity. Using the embedded devices, the researchers were then able to detect electrical signals generated by cells deep within the tissue, and to measure changes in those signals in response to cardio- or neuro-stimulating drugs.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Books and JavaScript stored in DNA molecules

Books and JavaScript stored in DNA molecules | Amazing Science | Scoop.it

The computers of the future might store data in DNA. George Church of the Wyss Institute at Harvard University and colleagues have encoded a 53,400-word book, 11 JPG images and a JavaScript program – amounting to 5.27 million bits of data in total – into sequences of DNA. In doing so, they have beaten the previous record set by J. Craig Venter's team in 2010 when they encoded a 7920-bit watermark in their synthetic bacterium.

 

DNA is one of the most dense and stable media for storing information known. In theory, DNA can encode two bits per nucleotide. That's 455 exabytes – roughly the capacity of 100 billion DVDs – per gram of single-stranded DNA, making it five or six orders denser than currently available digital media, such as flash memory. Information stored in DNA can also be read thousands of years after it was first laid down.

 

Until now, however, the difficulty and cost involved in reading and writing long sequences of DNA has made large-scale data storage impractical. Church and his team got round this by developing a strategy that eliminates the need for long sequences. Instead, they encoded data in distinct blocks and stored these in shorter separate stretches. The strategy is exactly analogous to data storage on a hard drive, says co-author Sriram Kosuri, where data is divided up into discrete blocks called sectors. The team has also applied their strategy in practice. They converted a JavaScript program, and a book co-written by Church, into bit form. They then synthesised DNA to repeat that sequence of bits, encoding one bit at every DNA base. The DNA bases A or C encoded a '0', while G and T encoded a '1'.

 

Because the DNA is synthesised as the data is encoded, the approach doesn't allow for rewritable data storage. A write-only DNA molecule is still suitable for long-term archival storage, though. "I don't want to say rewriting is impossible," says Kosuri, "but we haven't yet looked at that."

 

But the result does show that DNA synthesis and sequencing technologies have finally progressed to the stage where integrating DNA sequence information into a storage medium is a real possibility, says Dan Gibson at the J. Craig Venter Institute in La Jolla, California, who was part of Venter's team in 2010. "Cost, speed and instrument size currently make this impractical for general use, but the field is moving fast, and the technology will soon be cheaper, faster and smaller," he says.

 

Original article: Science, DOI:10.1126/science.293.5536.1763c

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

With drug-loaded nanogel, Yale researchers attack cancerous tumors

With drug-loaded nanogel, Yale researchers attack cancerous tumors | Amazing Science | Scoop.it

Yale University scientists have developed a new mechanism for attacking cancerous tumors that intensifies the body’s immune response while simultaneously weakening the tumor’s ability to resist it. Tumors — in this case metastatic melanomas, or spreading skin cancers — are adept at overcoming their host’s natural defenses, in part by emitting agents that disrupt production and operation of the immune system.

 

The Yale team developed a new biodegradable nanoparticle that delivers a combination of two very different therapeutic agents to tumor sites, gradually releasing the agents into the tumor vasculature. One agent, a large soluble protein called a cytokine, stimulates the body’s innate immune response. The other, a small-molecule inhibitor, interferes with the tumor’s ability to suppress the immune response. Other drug combinations are possible.

 

In tests on live mice, the double-loaded particle, called a nanogel, significantly delayed tumor growth and increased survival, the researchers report. They administered the nanogels intravenously and, in separate experiments, directly into the tumors. Further animal tests are planned.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Tractor Beams Work In Lab On Increasingly Larger Objects: First Quantum Effects In An Optomechanical System

Tractor Beams Work In Lab On Increasingly Larger Objects: First Quantum Effects In An Optomechanical System | Amazing Science | Scoop.it

A long-time staple of science fiction is the tractor beam, a technology in which light is used to move massive objects – recall the tractor beam in the movie Star Wars that captured the Millennium Falcon and pulled it into the Death Star. While tractor beams of this sort remain science fiction, beams of light today are being used to mechanically manipulate atoms or tiny glass beads, with rapid progress being made to control increasingly larger objects. Those who see major roles for optomechanical systems in a host of future technologies will take heart in the latest results from a first-of-its-kind experiment.

 

Berkeley Lab researchers directly observed quantum optical effects -- amplification and ponderomotive squeezing -- in an optomechanical system. Here the yellow/red regions show amplification, the blue regions show squeezing. On the left is the data, on the right is the theoretical prediction in the absence of noise. Scientists with the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California (UC) Berkeley, using a unique optical trapping system that provides ensembles of ultracold atoms, have recorded the first direct observations of distinctly quantum optical effects - amplification and squeezing - in an optomechanical system. Their findings point the way toward low-power quantum optical devices and enhanced detection of gravitational waves among other possibilities.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

The highest possible resolution for color images — about 100,000 dots per inch — has been achieved

The highest possible resolution for color images — about 100,000 dots per inch — has been achieved | Amazing Science | Scoop.it

Images made up of metal-nanostructure pixels could be used for security or optical data storage. Each pixel in these ultra-resolution images is made up of four nanoscale posts capped with silver and gold nanodisks. By varying the diameters of the structures (which are tens of nanometers) and the spaces between them, it’s possible to control what color of light they reflect. Researchers at the Agency for Science, Technology and Research (A*STAR) in Singapore used this effect, called structural color, to come up with a full palette of colors. As a proof of principle, they printed a 50×50-micrometer version of the ‘Lena’ test image, a richly colored portrait of a woman that is commonly used as a printing standard.

 

Joel Yang, a materials scientist A*STAR, who led the study, first noticed the effect when looking at metal nanoparticles under a light microscope. “We saw that we could control the colors, from red to blue, by controlling the size of the particles,” he says. Depending on its size, a metal nanostructure resonates with a particular wavelength of light — much like a guitar string resonates at a particular frequency depending on its length. Light at the right wavelength causes electrons on the surface of the metal nanostructure to resonate, and this determines the color the structure reflects. This effect, called plasmon resonance, is well known to physicists. Yang is the first to come up with a way to take advantage of it to print high-resolution, full-color images, says Jay Guo, an engineer at the University of Michigan in Ann Arbor, who was not involved with the work.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Micron-Scale Swimming Robots To Deliver Drugs, Carrying Cargo

Micron-Scale Swimming Robots To Deliver Drugs, Carrying Cargo | Amazing Science | Scoop.it

Georgia Institute of Technology researchers have used complex computational models to design swimming micro-robots that could carry cargo and navigate in response to stimuli such as light. The micron-scale (about 1 millionth of a meter) devices could be used in drug delivery in the body, in lab-on-a-chip microfluidic systems, and even as micro-construction robots working in swarms.

 

The concept is similar to other micro-robots, but the Georgia Tech design focuses uniquely on hydrogels and computational fluid modeling. When you’re just a few microns long, swimming can be difficult. At that size scale, the viscosity of water is more like that of honey, and momentum can’t be relied upon to maintain forward motion. But with hydrogels, their volume changes in a cyclical way. So they would serve as “chemical engines” to provide the motion needed to move the device’s propulsive flaps. Such materials currently exist and are being improved upon for other applications.

 

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

World’s Smallest Semiconductor Laser Created

World’s Smallest Semiconductor Laser Created | Amazing Science | Scoop.it

Physicists at The University of Texas at Austin, in collaboration with colleagues in Taiwan and China, have developed the world’s smallest semiconductor laser, a breakthrough for emerging photonic technology with applications from computing to medicine. Miniaturization of semiconductor lasers is key for the development of faster, smaller and lower energy photon-based technologies, such as ultrafast computer chips; highly sensitive biosensors for detecting, treating and studying disease; and next-generation communication technologies.

 

Such photonic devices could use nanolasers to generate optical signals and transmit information, and have the potential to replace electronic circuits. But the size and performance of photonic devices have been restricted by what’s known as the three-dimensional optical diffraction limit. The new device is constructed of a gallium nitride nanorod that is partially filled with indium gallium nitride. Both alloys are semiconductors used commonly in LEDs. The nanorod is placed on top of a thin insulating layer of silicon that in turn covers a layer of silver film that is smooth at the atomic level.

more...
No comment yet.