Articles from October 2012

Fuel Cell Output at Lower Cost for Electric Car

Fuel cells, which convert fuel directly into electricity without burning it, promise a less polluted future where cars run on pure hydrogen and exhaust nothing but water vapor. But the catalysts that make them work are still “sluggish” and worse, expensive. A research team at the Cornell Energy Materials Center has taken an important step forward with a chemical process that creates platinum-cobalt nanoparticles with a platinum enriched shell that show improved catalytic activity.

This could be a real significant improvement. It enhances the catalysis and cuts down the cost by a factor of five,” said Héctor Abruña, the E.M. Chamot Professor of Chemistry and Chemical Biology, senior author of a paper describing the work in the Oct. 28 issue of the journal Nature Materials. Co-authors include Francis DiSalvo, the John Newman Professor of Chemistry and Chemical Biology, and David Muller, professor of applied and engineering physics and co-director of the Kavli Institute at Cornell for Nanoscale Science.


Strong Invisible Braces in Orthodontics

Braces made from clear plastic polymer used in dental correction orthodontics have produced very good results in recent years, especially in relation to the improved esthetics when compared to metal braces, but they do present certain problems of wear and tear within the mouth. Researchers from UC3M, has produced a new material which increases mechanical as well as friction resistance, thereby maintaining the braces’ transparency. The new technique has been patented. The Polymers and Composites research group belongs to the Materials Science and Engineering and Chemical Engineering Department of the University Carlos III of Madrid, Spain. Its objective is the development and characterization of polymeric materials, focussed in their reinforcement through the
dispersion of nanoparticles. Following this method, very small additions of nanoreinforcements usually improve mechanical, electrical and optical properties, as well as the service performance of these materials.

We were estimating the friction between teeth and the brackets [braces], and it occurred to us that nanotechnology might be of use to help us resolve this issue,” remarked Juan Baselga, head of the UC3M Polymers and Composite Group.

How To Detect Early-Stage Diseases With Naked Eye

In poor countries, affordable methodologies for the detection of disease biomarkers at ultralow concentrations can potentially improve the standard of living. However, current strategies for ultrasensitive detection often require sophisticated instruments that may not be available in laboratories with fewer resources.
Now a research team from the Imperial College London -United Kingdom- reports that their visual sensor technology is ten times more sensitive than the current gold standard methods for measuring biomarkers. These indicate the onset of diseases such as prostate cancer and infection by viruses including HIV.

Professor Molly Stevens, from the Departments of Materials and Bioengineering at Imperial College London, says: “It is vital that patients get periodically tested in order to assess the success of retroviral therapies and check for new cases of infection. Unfortunately, the existing gold standard detection methods can be too expensive to be implemented in parts of the world where resources are scarce. Our approach affords for improved sensitivity, does not require sophisticated instrumentation and it is ten times cheaper, which could allow more tests to be performed for better screening of many diseases.”


Nanoparticule Delivers 3 Times More Doses Against Bladder Cancer

A team of University of California Davis – UC Davis – scientists has shown in experimental mouse models that a new drug delivery system allows for administration of three times the maximum tolerated dose of a standard drug therapy for advanced bladder cancer, leading to more effective cancer control without increasing toxicity. The delivery system consists of specially designed nanoparticles that home in on tumor cells while carrying the anti-cancer drug paclitaxel. The same delivery system also was successfully used to carry a dye that lights up on imaging studies, making it potentially useful for diagnostic purposes.

We have developed a novel, multifunctional nanotherapeutics platform that can selectively and efficiently deliver both diagnostic and therapeutic agents to bladder tumors,” said Chong-Xian Pan, principal investigator of the study and associate professor of hematology and oncology at UC Davis. “Our results support its potential to be used for both diagnostic and therapeutic applications for advanced bladder cancer.”


Living Power Cables

Electricity and seawater are usually a bad mix. And it was thus a very big surprise when scientists from Aarhus University – Denmark – a few years ago discovered electric currents between biological processes in the seabed. Since then they have been searching for an explanation and together with partners from the University of Southern California, USA, they have solved the enigma of electric currents in the seabed sensationally discovering bacteria that function as living electrical cables. Each of the centimetre-long ‘cable bacteria’ contains a bundle of insulated wires leading an electric current from one end to the other.

Our experiments showed that the electric connections in the seabed must be solid structures built by bacteria,” says PhD student Christian Pfeffer, Aarhus University.The bacterium is one hundred times thinner than a hair and the whole bacterium functions as an electric cable with a number of insulated wires within it. Quite similar to the electric cables we know from our daily lives. “Such unique insulated biological wires seem simple but with incredible complexity at nanoscale,” says PhD student Jie Song, Aarhus University, who used nanotools to map the electrical properties of the cable bacteria.

Nano-Machines Mimic Human Muscle

Nature manufactures numerous machines known as “molecular”. Highly complex assemblies of proteins, they are involved in essential functions of living beings such as the transport of ions, the synthesis of ATP (the “energy molecule”), and cell division. Our muscles are thus controlled by the coordinated movement of these thousands of protein nano-machines, which only function individually over distances of the order of a nanometer. However, when combined in their thousands, such nano-machines amplify this telescopic movement until they reach our scale and do so in a perfectly coordinated manner.
For the first time, an assembly of thousands of nano-machines capable of producing a coordinated contraction movement extending up to around ten micrometers – thereby amplifying the movement by a factor of 10,000, like the movements of muscular fibers, has been synthesized by a CNRS team from the Institut Charles Sadron – France.

This discovery opens up perspectives for a multitude of applications in robotics, in nanotechnology for the storage of information, in the medical field for the synthesis of artificial muscles or in the design of other materials incorporating nano-machines (endowed with novel mechanical properties).

How To Diagnose Lung Diseases at Early Stage

Severe lung diseases are among the leading causes of death worldwide. To date they have been difficult to diagnose at an early stage. Within an international collaboration scientists from Munich- Germany – now developed an X-ray technology to do just that. Now they are working on bringing the procedure into medical practice.
X-Ray Nanotechnology.
A combination of dark-field and conventional transmission information allows for a clear distinction of healthy versus emphysematous tissue and an assessment of the regional distribution of the disease. From such images, a doctor might in future not only see if a patient is diseased but also which parts of the lung are affected and how much.
Especially in early stages of the disease, identification, precise quantification and localization of emphysema through the new technology would be very helpful”, says Professor Maximilian Reiser, head of the Institute for Clinical Radiology at Ludwig-Maximilians-University Munich.


Machines Fabrication At Nanoscale

The fabrication of many objects, machines, and devices around us rely on the controlled deformation of metals by industrial processes such as bending, shearing, and stamping. Is this technology transferrable to nanoscale? Can we build similarly complex devices and machines with very small dimensions? Scientists from Aalto University in Finland and the University of Washington in the US have just demonstrated this to be possible. By combining ion processing and nanolithography they have managed to create complex three-dimensional structures at nanoscale. The discovery follows from a quest for understanding the irregular folding of metallic thin films after being processed by reactive ion etching.

We were puzzled by the strong-width-dependent curvatures in the metallic strips. Usually initially-strained bilayer metals do not curl up this way, explains Khattiya Chalapat from Aalto University.

Self-Assembled Nanoparticle for chemotherapy

Excitement around the potential for targeted nanoparticles (NPs) that can be controlled by stimulus outside of the body for cancer therapy has been growing over the past few years. More specifically, there has been considerable attention around near-infrared NIR light as an ideal method to stimulate nanoparticles from outside the body. NIR is minimally absorbed by skin and tissue, has the ability to penetrate deep tissue in a noninvasive way and the energy from NIR light can be converted to heat by gold nanomaterials for effective thermal ablation of diseased tissue.

In new research from Brigham and Women’s Hospital (BWH), researchers describe the design and effectiveness of a first-of-its-kind, self assembled, multi-functional, NIR responsive gold nanorods that can deliver a chemotherapy drug specifically targeted to cancer cells and selectively release the drug in response to an external beam of light while creating heat for synergistic thermo-chemo mediated anti-tumor efficacy. The study is electronically published in Angewandte Chemie International Edition.


Entire Genome Sequencing in Minutes?

The claim that nanopore technology is on the verge of making DNA analysis so fast and cheap that a person’s entire genome could be sequenced in just minutes and at a fraction of the cost of available commercial methods, has resulted in overwhelming academic, industrial, and global interest. But a review by Northeastern University – Boston – physicist Meni Wanunu, published in a special issue on nanopore sequencing in Physics of Life Reviews, questions whether the remaining technical hurdles can be overcome to create a workable, easily produced commercial device.

Earlier this year Oxford Nanopore Technologies, one of the pioneering companies of sequencing discoveries, announced that they expect nanopore strand sequencing to achieve a 15-minute genome by 2014 at a cost of $1,500. This is a far cry from the $10 million it cost to sequence an entire genome just 5 years ago. Since the idea of nanopore sequencing was first proposed in the mid 1990s, huge advances have been made. The basic idea is exceedingly simple: a single thread of DNA is passed through a tiny molecule-sized hole—or nanopore—and the various DNA bases are identified in sequence as they move through the pore.

But according to Wanunu, the reality of manipulating technology based on pores so tiny that 25,000 of them can fit side by side on a human hair has proved a daunting task. The main challenge has been to slow the process down and control the movement of the DNA strand through the pore at a rate slow enough to make individual DNA bases readable and usable. A new approach using enzyme-controlled movement, developed to overcome this problem, has its own drawbacks including poor enzyme activity resulting in limited processivity and uncontrolled forward-reverse motion.

20 Atoms Thicker Coatings Change Color

In Harvard’s Pierce Hall, the surface of a small germanium-coated gold sheet shines vividly in crimson. A centimeter to the right, where the same metallic coating is literally only about 20 atoms thicker, the surface is a dark blue, almost black. The colors form the logo of the Harvard School of Engineering and Applied Sciences (SEAS), where researchers have demonstrated a new way to customize the color of metal surfaces by exploiting a completely overlooked optical phenomenon. For centuries it was thought that thin-film interference effects, such as those that cause oily pavements to reflect a rainbow of swirling colors, could not occur in opaque materials. Harvard physicists have now discovered that even very “lossy” thin films, if atomically thin, can be tailored to reflect a particular range of dramatic and vivid colors.

Gold films colored with nanometer-thick layers of germanium.
The discovery is the latest to emerge from the laboratory of Federico Capasso, Robert L. Wallace Professor of Applied Physics and Vinton Hayes Senior Research Fellow in Electrical Engineering at SEAS, whose research group most recently produced ultrathin flat lenses and needle light beams that skim the surface of metals.


Breakthrough In Prostate Cancer Treatment

Currently, large doses of chemotherapy are required when treating certain forms of cancer, resulting in toxic side effects. The chemicals enter the body and work to destroy or shrink the tumor, but also harm vital organs and drastically affect bodily functions. Now, scientists at the University of Missouri have proven that a new form of prostate cancer treatment that uses radioactive gold nanoparticles, and was developed at MU, is safe to use in dogs. Sandra Axiak-Bechtel , an assistant professor in oncology at the MU College of Veterinary Medicine , says that this is a big step for gold nanoparticle research.

Proving that gold nanoparticles are safe to use in the treatment of prostate cancer in dogs is a big step toward gaining approval for clinical trials in men,” Axiak-Bechtel said. “Dogs develop prostate cancer naturally in a very similar way as humans, so the gold nanoparticle treatment has a great chance to translate well to human patients.”