April 29, 2008, 8:37 PM CT

Mini-Origami: ISI Folds Up Tiny Packages for Drug Delivery

Scientists at the USC Information Sciences Institute have demonstrated a way to manufacture miniscule containers that might be used to deliver precise micro- or even nano- quantities of drugs.

As per ISI project leader Peter Will, who is a research professor in the Viterbi School of Engineering, the new technique, described in a paper in the Journal of Micromechanics and Microengineering, is a two-step process.

Part one is the creation of flat patterns, origami, of exactly the fold up shapes familiar to kindergarten children making paper pyramids, cubes or other solids, except that these are as small as 30 micrometers on a side. (1 inch = 25,400 micrometers)(see illustration).

Instead of paper, the USC scientists created the patterns in polysilicon sitting on top of a thin film of gold, using a well- established commercial silicon wafer process called PolyMUMPs. The next step was clearing the polysilicon off the hinge areas by etching.

When the blanks were later electrocoated with permalloy to make them magnetic, the photomask used left hinge areas uncoated, to make sure they were the places that folded.

Then the folding had to be accomplished. First the scientists bent the hinges by application of magnetic force. Then water pressure and capillary forces generated by submerging the tiny blanks in water, and drying them off did the final folding into shape......... Posted by: Kevin      Read more         Source

April 29, 2008, 8:17 PM CT

New 3-D test method for biomaterials 'flat out' faster

A novel, three-dimensional (3-D) screening method for analyzing interactions between cells and new biomaterials could cut initial search times by more than half, scientists from the National Institute of Standards and Technology (NIST) and Rutgers University report in the new issue of Advanced Materials.* The technique, an advance over flat, two-dimensional screening methods, enables rapid assessment of the biocompatibility and other properties of materials designed for repairingor even rebuildingdamaged tissues and organs.

In what may be a first, the team demonstrated how to screen cellmaterial interactions in a biologically representative, but systematically altered, 3-D environment. The pivotal step in the experiment was the collaborators success in making so-called libraries of miniature porous scaffolds that are bone-like in structure but vary incrementally in chemical composition. Knowing how changes in scaffold ingredients influence cell responses, scientists can devise strategies for developing biomaterials optimized for particular therapies and therapys.

Until now, attempts to accelerate screening of candidate biomaterials have used flat films and surfaces. (See, for example, Designer Gradients Speed Surface Science Experiments, Tech Beat June 8, 2006. http://www.nist.gov/public_affairs/techbeat/tb2006_0608.htm#designer ) Along with other shortcomings, these two-dimensional substrates are neither consistent with cells normal 3-D environment inside the body nor with the most common intended use of biomaterials: creating scaffolds to encourage the growth of cells into functional 3-D tissues and organs......... Posted by: Kevin      Read more         Source

April 28, 2008, 8:31 PM CT

First nanoscale image of soil

A handful of soil is a lot like a banana, strawberry and apple smoothie: Blended all together, it is hard to tell what's in there, particularly if you have never tasted the fruits before.

But when you look at soil's organic carbon closely, it has an incredible variety of known compounds. And looking closely is exactly what Cornell scientists have done for the first time -- at a scale of 50 nanometers (1 nanometer equals the width of three silicon atoms). Until now, handfuls of soil humus (or the organic component of soil, formed by the decomposition of leaves and other plant material by soil microorganisms) looked remarkably similar.

As per a research studyreported in the recent issue of Nature Geoscience, knowing the structure and detailed composition of soil carbon could provide a better understanding of the chemical processes that cycle organic matter in soil. For example, the research may help researchers understand what happens when materials in the soil get wet, warm or cool and how soils sequester carbon, which has implications for climate change.

"There is this incredible nanoscale heterogeneity of organic matter in terms of soil," said Johannes Lehmann, a Cornell associate professor of crop and soil sciences and lead author of the study. "None of these compounds that you can see on a nanoscale level looks anything close to the sum of the entire organic matter."........ Posted by: Kevin      Read more         Source

April 28, 2008, 5:20 PM CT

Copper nanowires grown by new process

A new low-temperature, catalyst-free technique for growing copper nanowires has been developed by scientists at the University of Illinois. The copper nanowires could serve as interconnects in electronic device fabrication and as electron emitters in a television-like, very thin flat-panel display known as a field-emission display.

We can grow forests of freestanding copper nanowires of controlled diameter and length, suitable for integration into electronic devices, said Kyekyoon (Kevin) Kim, a professor of electrical and computer engineering.

The copper nanowires are grown on a variety of surfaces, including glass, metal and plastic by chemical vapor deposition from a precursor, said Hyungsoo Choi, a research professor in the Micro and Nanotechnology Laboratory and in the department of electrical and computer engineering. The patented growth process is compatible with contemporary silicon-processing protocols.

The scientists describe the nanowires, the growth process, and.

a proof-of-principle field-emission display in a paper accepted for publication in the journal Advanced Materials, and posted on its Web site.

Typically, the nanowires of 70 to 250 nanometers in diameter are grown on a silicon substrate at temperatures of 200 to 300 degrees Celsius and require no seed or catalyst. The size of the nanowires is controlled by the processing conditions, such as substrate, substrate temperature, deposition time and precursor feeding rate. The columnar, five-sided nanowires terminate in sharp, pentagonal tips that facilitate electron emission......... Posted by: Kevin      Read more         Source

April 22, 2008, 9:24 PM CT

Making New Optical Materials

Chemical engineers have developed a "self-assembling" method that could lead to an inexpensive way of making diamondlike crystals to improve optical communications and other technologies.

The method, developed at Purdue University, works by positioning tiny particles onto a silicon template containing precisely spaced holes that are about one-hundredth the width of a human hair. The template is immersed in water on top of which particles are floating, and the particles automatically fill in the holes as the template is lifted.

The scientists have used the technique to create a "nearly perfect two-dimensional colloidal crystal," or a precisely ordered layer of particles. This is a critical step toward growing three-dimensional crystals for use in optical technologies, said You-Yeon Won, an assistant professor of chemical engineering.

"Making the first layer is very difficult, so we have taken an important step in the right direction," Won said. "Creating three-dimensional structures poses a big challenge, but I think it's feasible".

Findings were detailed in a paper appearing online April 9 in the journal Soft Matter, published by the Royal Society of Chemistry in the United Kingdom. The paper was written by graduate student Jaehyun Hur and Won......... Posted by: Kevin      Read more         Source

April 17, 2008, 7:39 PM CT

Wanted: Forty-thousand More Health IT Professionals

Study by OHSU expert says a 40 percent hike in IT workforce will be needed to move U.S. healthcare toward a paperless system that controls costs and reduces medical errors.

If the U.S. healthcare system moves toward wider adoption of advanced information technology systems to control health care costs, reduce medical errors and improve patient care, it will need at least 40,000 additional health IT professionals - or almost 40 percent more than U.S. hospitals now are estimated to employ.

That is the finding of an analytical report presented today, at a meeting on Capitol Hill of the Steering Committee on Telehealth and Healthcare Informatics, by William Hersh, M.D., professor and chair of the Department of Medical Informatics & Clinical Epidemiology at Oregon Health & Science University.

The meeting was moderated by U.S. Rep. David Wu, D-Ore., author of a bill, H.R. 1467, addressing the need to train more health IT professionals, which the House passed recently and that is awaiting consideration in the Senate.

"I commend Dr. Hersh for his research on healthcare IT workforce issues," said Rep. Wu. "His findings further justify the need for my 10,000 Trained by 2010 Act, which provides funds for healthcare IT education. A workforce trained in healthcare IT is essential to bringing greater quality and efficiency to the healthcare industry"......... Posted by: Mac      Read more         Source

April 10, 2008, 8:08 PM CT

Forecasters Implement New Hurricane-Tracking Technique

A new technique that helps forecasters continuously monitor landfalling hurricanes, giving them frequent and detailed images of a storm's location, will be implemented this summer.

The new system, developed by National Science Foundation (NSF)-funded scientists at the National Center for Atmospheric Research (NCAR) in Boulder, Colo., and the Naval Research Laboratory (NRL) in Washington, D.C., will be implemented at the National Hurricane Center (NHC).

The technique, known as VORTRAC (Vortex Objective Radar Tracking and Circulation), was successfully tested by the hurricane center last year.

"VORTRAC is an excellent example of the application of basic research to help improve short-term hurricane warnings," says Steve Nelson, program director in NSF's Division of Atmospheric Sciences.

The system, which relies on existing Doppler radars along the U.S. coast, provides details on hurricane winds and central pressure every six minutes, indicating whether the storm is gathering strength in the final hours before reaching shore.

"We are very gratified by the decision of the National Hurricane Center to adopt this new now-casting tool," says NCAR scientist Wen-Chau Lee. "VORTRAC will enable hurricane specialists, for the first time, to continuously monitor the trend in central pressure as a dangerous storm nears land. With the help of VORTRAC, vulnerable communities can be better informed of sudden changes in hurricane intensity."......... Posted by: Kevin      Read more         Source

April 8, 2008, 10:27 PM CT

Don't Create the Wonder Pollutant

Carbon nanotubes are 10,000 times thinner than a human hair, yet stronger than steel and more durable than diamonds. They conduct heat and electricity with efficiency that rivals copper wires and silicon chips, with possible uses in everything from concrete and clothes to bicycle parts and electronics. The have been hailed as the next "wonder material" for what could become a multi-billion dollar manufacturing industry in the 21st century. But as useful as nanotubes may be, the process of making them may have unintentional and potentially harmful impacts on the environment.

MIT/WHOI graduate student Desiree Plata and her mentors-chemists Phil Gschwend of the Massachusetts Institute of Technology and Chris Reddy of the Woods Hole Oceanographic Institution-recently analyzed ten commercially made carbon nanotubes to identify the chemical byproducts of the manufacturing process and to help track them in the environment. Plata observed that the ten different carbon nanotubes had vastly different compositions; most prior toxicity studies have generally assumed that all nanotubes are the same.

This diversity of chemical signatures will make it harder to trace the impacts of carbon nanotubes in the environment. In prior work (first presented last fall), Plata and his colleagues observed that the process of nanotube manufacturing produced emissions of at least 15 aromatic hydrocarbons, including four different kinds of toxic polycyclic aromatic hydrocarbons (PAHs) similar to those found in cigarette smoke and automobile tailpipe emissions. They also observed that the process was largely inefficient: much of the raw carbon went unconsumed and was vented into the atmosphere. The new research by Plata et al was published April 3 on the web site of the journal Nanotechnology. ........ Posted by: Kevin      Read more         Source

April 7, 2008, 10:43 PM CT

Money Doesn't Grow on Trees, But Gasoline Might

Scientists have made a breakthrough in the development of "green gasoline," a liquid identical to standard gasoline yet created from sustainable biomass sources like switchgrass and poplar trees.

Reporting in the cover article of the April 7, 2008 issue of Chemistry & Sustainability, Energy & Materials (ChemSusChem), chemical engineer and National Science Foundation (NSF) CAREER awardee George Huber of the University of Massachusetts-Amherst (UMass) and his graduate students Torren Carlson and Tushar Vispute announced the first direct conversion of plant cellulose into gasoline components.

In the same issue, James Dumesic and his colleagues from the University of Wisconsin-Madison announce an integrated process for creating chemical components of jet fuel using a green gasoline approach. While Dumesic's group had previously demonstrated the production of jet-fuel components using separate steps, their current work shows that the steps can be integrated and run sequentially, without complex separation and purification processes between reactors.

While it may be five to 10 years before green gasoline arrives at the pump or finds its way into a fighter jet, these breakthroughs have bypassed significant hurdles to bringing green gasoline biofuels to market......... Posted by: Kevin      Read more         Source

April 6, 2008, 8:51 PM CT

As nanotech goes mainstream

Nanotechnology is now available in a store near you.

Valued for its antibacterial and odor-fighting properties, nanoparticle silver is becoming the star attraction in a range of products from socks to bandages to washing machines. But as silvers benefits propel it to the forefront of consumer nanomaterials, researchers are recommending a closer examination of the unforeseen environmental and health consequences of nanosilver.

The general public needs to be aware that there are unknown risks linked to the products they buy containing nanomaterials, scientists Paul Westerhoff and Troy M. Benn said in a report scheduled for the 235th national meeting of the American Chemical Society (ACS).

Westerhoff and Benn report that ordinary laundering can wash off substantial amounts of the nanosilver particles from socks impregnated with the material. The Arizona State scientists suggest that the particles, intended to prevent foot odor, could travel through a wastewater therapy system and enter natural waterways where they might have unwanted effects on aquatic organisms living in the water and possibly humans, too.

This is the first report of anyone looking at the release of silver from this type of manufactured clothing product, said the authors......... Posted by: Kevin      Read more         Source