October 14, 2005

Penn Researchers Discover The Powerful Tool Of Simultaneous fMRI And PET Imaging

Better Use Of Nanotubes As Measuring Tips

Advances with atomic force microscope accuracy advance us on the path towards molecular manufacturing. However, this does not achieve 0.5 angstrom accuracy as some Scanning Electron Microscopes have. It does help more labs get greater accuracy.

Engineers at Purdue University have shown how researchers might better use tiny hollow fibers called "multi-walled carbon nanotubes" to more precisely measure structures and devices for electronics and other applications Researchers attach the tubes to the ends of imaging instruments called atomic force microscopes. Because the tubes are long and slender, their shape is ideal for the emerging field of "nanometrology," which is precisely measuring structures on the scale of nanometers, or billionths of a meter.

Researchers use nanotubes as probes by inducing a vibration in a portion of the microscope assembly called a microcantilever.

"The microcantilever, which does all of the surface sensing, can be thought of as a very small oscillating diving board on which the silicon tip and nanotube are mounted to the free end," Strus said.

As the microcantilever vibrates, the nanotube tip comes close to the surface but never actually touches the object being imaged. The closer the tip comes to the surface, the more powerful the attractive van der Waals' forces become. The increasing attraction causes changes in the vibration pattern of the oscillating microcantilever, and the changing pattern is carefully monitored to reveal precise changes in contours on the surface of the object, yielding an image.

The same forces that enable the technology to work, however, also cause the sticking action of the probe. The vibrating tip sticks to the sides of the object being imaged, producing "artifacts," or inaccuracies in the measurements and images.

The researchers showed precisely how artifacts are created by the sticking nanotubes, which are about 25 nanometers thick. The researchers also have shown how to avoid these artifacts by adjusting operating parameters of the microscope to prevent the tube from sticking.

The research was funded by the Centre for Nanomechatronics and Manufacturing in South Korea, and the work is associated with Purdue's Birck Nanotechnology Center, which is part of Discovery Park, the university's hub for interdisciplinary research.

October 13, 2005

Nanoparticle enhanced protein detection for medical diagnosis

This is not molecular manufacturing related but improved ability to detect proteins is part of enhanced protein handling that can be part of a protein based assembler.

Northbrook, Illinois-based Nanosphere is preparing to launch a diagnostic system that uses nanoparticles to detect various proteins at a level of sensitivity never before seen. Scientists know that a protein called prostate-specific antigen, or PSA, is linked with some forms of breast and ovarian cancer. But levels of PSA are so low in women that they're impossible to detect with existing technology. Nanosphere researchers say their technology can do the trick.

"In the end, molecular biology is about amplification," said Northwestern University nanotechnologist Chad Mirkin, who is a co-founder of the company and sits on its board of directors. "If you can amplify a signal that's happening on the cellular level to the point where you can detect it at the human level, you can do great science." The Nanosphere system increases the sensitivity for detecting recognized proteins by six orders of magnitude. "Nobody else can get close to that," Mirkin said.

Nanosphere hopes to have a PSA screen ready by next year for breast and ovarian cancer as well as prostate cancer. Doctors now test for PSA in men using the ELISA protein assay, which costs hundreds of dollars per test and requires high concentrations of the protein to be successful.

At the heart of Nanosphere's unique system are silver-coated nanoballs. Each ball is attached to a synthetic probe designed to bind with a specific protein. If a patient sample contains the protein of interest (for example, a protein linked to a particular type of cancer), it will be sandwiched by the silver nanoparticle and a larger, magnetized metal ball.

A magnet then removes the metal balls, carrying the target proteins and the highly reflective silver spheres along with it. Light reflected from the sample reveals the concentration of the target protein in the patient, even if only a few molecules are present in the sample.

Several emerging companies are trying to create amplification technologies based on quantum dots, another nanotechnology that causes fluorescence in the presence of specific proteins. But those companies aren't yet at the point of considering a mass-market product. Another startup, called Nanoplex Technologies, is also developing a system using metallic nanospheres for protein and nucleic-acid detection, but it is concentrating on the scientific research market, not clinical diagnostics.

October 12, 2005

Engineers build DNA 'nanotowers' with enzyme tools

This work is advancing the DNA-Protein-enzyme pathway to molecular manufacturing. It is a process that is advancing toward scalable industrialized processes.

Engineers build DNA 'nanotowers' with enzyme tools Duke engineers have added a new construction tool to their bio-nanofabrication toolbox. Using an enzyme called TdTase, engineers can vertically extend short DNA chains attached to nanometer-sized gold plates. This advance adds new capability to the field of bio-nanomanufacturing. Last year, Chilkoti and his team demonstrated an enzyme-driven process to "carve" nanoscale troughs into a field of DNA strands. By combining this technique with the new method of adding vertical length to the DNA strands, they can now create surfaces with three-dimensional topography.

The team starts with a forest of short DNA strands that cover nanoscale patches of gold, lithographed onto a silicon substrate. The researchers then submerge the substrate in a solution that contains the TdTase (terminal deoxynucleotidyl transferase) enzyme, a cobalt catalyst and the molecular building blocks, called nucleotides, of DNA chains.

Over an hour, the TdTase enzyme grabs the free-floating nucleotides and builds nanoscale "towers" above the surface by extending each DNA strand, increasing its height a hundredfold. In addition, the process works at room temperature in an incubator that maintains humidity, Chilkoti said.

Chilkoti said the next step towards bio-nanofabrication is to create a little crane to pick up, move and place biological molecules in precise locations on three-dimensional DNA surfaces.

"When we can place molecules in the right configuration, then we can get them to function. At that point, we can design and create biological machines that accomplish something," he said

China's Military and economy

There is an article and report by the Center for Economic and Policy Research (CEPR) where there are projections of a deficit in US military spending as China's economy grow. The assumptions in this report and the time frame is nuts. They are talking about a big deficit in 2050-2080 assuming higher than US per capita PPP growth in the Chinese economy for 75 years. To illustrate the absurdity of this, if we project that Google keeps growing at a higher rate trailing off slowly from 95% per quarter starting from $1.1B in Q1 2005, we can see that Google will nearly double every quarter and own both the USA and China in 2010 in the high growth scenario and 2012 in the slow growth and 2015 in the low growth. Thus Google will own both the US and Chinese military by 2015 and we will have pax Google.

On a slightly more analytical level, China is currently buying a lot of Russia gear and I think they are trying to buy stuff from France. Analysis of recent advances in China's military capability and here Much of the advance is from purchases of older russian fighters and submarines. That portion of the Chinese military budget has to be GDP based because they are using hard currency to buy subs and fighters. Similarly oil for the military has to be GDP based. A pure PPP only makes any kind of sense if China had a fully indigineous military development capability. As China gets richer, PPP and GDP will come together.

I am a China optimist but even I do not think its growth will race ahead of the USA for 75 years. Plus just catching economy and budget wise, China has to overcome the fixed military assets of the USA. The USA has more advanced submarines and aircraft carriers that they bought from previous years. That capability still will exist in the future.

Think of it this way. I am twenty times poorer than my gun collecting survivalist friend. I live in Missouri and he lives in California. My house would be 2/3 of the value of his house if my house was in California. If over thirty years I catch up with his salary on a purchasing power basis (I could buy the same stuff in Missouri that he can buy in California). It will still take me a long time to spend 10% of my money and build my own guns and fertilizer bombs to equal his collection even as my 7% salary increases continue to exceed his 3.5%.

MIT launches global medical nanotech (not molecular manufacturing) push

Leaders of 10 research universities from around the world will gather at the Massachusetts Institute of Technology today to launch an international collaboration to use nanotechnology tools for global health and medical research. The collaboration, called GEM4, or Global Enterprise for Micro-Mechanics and Molecular Medicine, represents an ambitious effort to apply global sourcing principles to research at the intersection of engineering and life sciences.

The conference was organized by Subra Suresh, head of MIT's department of materials science and engineering.

MIT's president, Susan Hockfield, said in an interview that the initiative could herald a new model for international research, with far-flung researchers sharing their expertise in person, online, and through teleconferencing.

October 11, 2005

Protein-based assembly of nanoscale parts

Robert Bradbury provides a broad analysis of protein-based assembly He discusses recent capabilities in molecular electronics (rotaxane) and organic chemistry. He describes why the march of progress in computers, computer aided enzyme design and algorithms are lowering the cost necessary to advance protein assembly to be able to manufacture a programmable nano-assembler (PNA).

Probably in 2005 the design of a complete assembly line is a $100 million project and the actual implementation in the range of $1 billion.

Similar costs are reasonable expectations for a mechanosythesis effort.

Some current protein design work:

David Baker, who's team created Top7, the first articial protein in 2003. They are developing improved methods to predict and redesign protein-DNA interaction specificity, and extending their protein design methodology to the design of enzymes that catalyze chemical reactions not catalyzed by naturally occurring proteins.

A discussion of possibilites for creating artificial enzymes These are generally synthetic polymers or oligomers with enzyme-like activities, often called synzymes.

October 09, 2005

Advanced S/TEMs and other advanced microscope makers and projects

FEI announced Aug 1, 2005 that it is shipping its new scanning/ transmission electron microscope (S/TEM), the Titan(TM) 80-300 as it publicly unveiled the new system at the Microscopy and Microanalysis 2005 Conference in Honolulu. With an all-new platform dedicated to correction and monochromator technology, the Titan S/TEM system is the world's highest resolution commercially-available microscope, yielding powerful sub-Angstrom (atomic scale) imaging and analysis.

The first shipments of the Titan 80-300 S/TEM will begin in the current fiscal quarter. Among the first customers in line for delivery include The Center for Accelerated Maturation of Materials at Ohio State University (USA), the Department of Inorganic Chemistry and Catalysis of the Fritz-Haber Institute (Germany), Samsung Advanced Institute of Technology (Korea), and Instituto Mexicano del Petroleo/IMP (Mexico).

Titan's dedicated platform for corrector and monochromator technologies and their applications is designed for a high degree of automation and provides ultimate stability, performance and flexibility. The microscope transfers information deep into sub-Angstrom resolution making way for the highest performance available in both transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) modes.

FEI's shipment of the Titan S/TEM marks a significant milestone in its leadership of providing the world's most powerful tools for nanotechnology. In a November 2004 news release, FEI announced that it was selected as the R&D partner for a program aimed at building the highest resolution scanning/transmission electron microscope (S/TEM) in the world. The program is headed by several regional USA laboratories that combined to form the TEAM project. This multi-year microscopy development project calls for a new microscope, based on the Titan platform, that should enable extraordinary new scientific opportunities for direct observation aimed at enabling analysis of individual nanostructures at an unprecedented resolution of 0.5 Angstrom -- approximately one-third the size of a carbon atom.

As indicated by Robert Freitas in his paper and presentation on pathways to Diamondoid manufacturing the positioning resolution and repeatability need to be 0.5 angstroms for mechanosynthesis. There is also a need for controllable end effectors.

Other leading companies with high resolution SEMs are:
Pacific Nanotechnology with their Nano-R SEM, click for specifications and information.

Queensgate Instruments who makes custom nanoposition solutions there nanomechanism descriptions are here.

Physik Instrumente is also a leader in nanopositioning systems

Japan Electron Optics Lab also has aberration corrected devices.

A Microscope technology project that FEI company is involved in is the Transmission Electron Aberration-corrected Microscope (TEAM) project funded by the Department of Energy for $100 million and being run out of the national labs.

The intention of the project is to develop a transmission electron microscope capable of half an angstrom (0.05 nanometres or 0.5 x 10−10 metres) resolution, about half the size of a hydrogen atom. As electron microscope lenses normally produce a significant amount of aberration, a complex system of lenses to correct the aberrated images is required.

the National center for Electron Microscopy is at Lawrence Berkeley National Laboratory. The projects that they have to improve electron microscopy are listed here The
official TEAM project page is here. Other microscopy links.

there is advanced microscopy work at the SuperSTEM facility in the UK and at least two other european locations Scientists can rent time on the SuperSTEM at about 2000 pounds per day.

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