Showing Spotlights 2649 - 2656 of 2837 in category All (newest first):
Back in 2001, Swedish researchers developed techniques for creating complex two- and three-dimensional networks of nanotubes and micrometer-sized containers from liquid crystalline lipid bilayer materials based on the propensity in liposomes to undergo complex shape-transitions under mechanical excitations. The membrane composition and container contents can be controlled allowing chemical programming of networks in studies of enzyme kinetics, reaction-diffusion phenomena, and single-biomolecule detection. Materials contained in the networks can be routed among containers. Thus, networks of nanotubes and vesicles serve as a platform to build nanofluidic devices operating with single molecules and particles and offer new opportunities to study chemistry in confined biomimetic compartments. The networks can furthermore be used to build nanoscale chemical laboratories for applications in analytical devices as well as to construct computational and complex sensor systems that can also be integrated to living cells. In recent work, the researchers have now demonstrated that these nanotube-container networks can be constructed directly from plasma membranes of cultured cells.
Nov 8th, 2006
Conventional diagnostic imaging is mainly based on morphological contrast that is a result of different general tissue characteristics. Molecular imaging is a new approach for detecting diseases much earlier, visualizing biological processes at the cellular and molecular level in living organisms, and detecting changes in biochemistry. Corresponding molecular markers appear in quite low concentrations. Hence, the imaging technique must be very sensitive. Magnetic resonance imaging (MRI) has some significant advantages in terms of using non-ionizing radiation (in contrast to x-rays) and giving high resolution tomographies for any arbitrary position and orientation. However, conventional MRI suffers from inherent low sensitivity. A new method, using xenon as the signal source, was developed by researchers in California and will make MRI an important technique in molecular imaging, offering a huge potential for specific detection of disease markers. The new technique allows detection of signals from molecules present at 10,000 times lower concentrations than conventional MRI techniques. Called HYPER-CEST, for hyperpolarized xenon chemical exchange saturation transfer, this new technique could become a valuable tool for medical diagnosis, including the early detection of cancer.
Nov 7th, 2006
The interest in research on magnetic nanocapsules has increased considerably since it was found that their intermediate states between bulk and atomic materials may present different magnetic behaviors from their correspondent bulk counterparts. This difference offers an opportunity for researchers to develop many important technical applications such as magnetic refrigerators, magnetic recording, or magnetic fluids. As the principal contributor of the novel properties, various magnetic cores of nanocapsules, including rare earths and their carbides, have been researched extensively over the past two decades. In addition, cores of magnetic rare-earth intermetallic compounds are becoming a major research focus. However, there have been considerable difficulties in preventing oxidation of the particles of rare-earth elements and compounds. Researchers in PR China have now succeeded in synthesizing a new type of intermetallic nanocapsule that can be applied in cyrogenic magnetic refrigerator devices.
Nov 6th, 2006
R+D activities in nanotechnology in Canada are spearheaded by the federal government, provincial governments, as well as universities and national institutes. At the federal level, 9 institutes of the National Research Council (NRC), are conducting R+D in nanotechnology, while the major concentration of both research and industry can be found in Alberta, British Columbia, Ontario and Quebec. Most of these provinces have already established or will establish province-wide consortiums to promote economic development through nanotechnology. Currently, there are between 50 to 200 companies engaged in nanotechnology-related businesses, with numbers varied depending upon the definition of 'nanotechnology'.
Nov 3rd, 2006
Various methods have been developed for growing well-aligned CNTs based on variant alignment mechanisms such as 'overcrowding growth', 'template hindrance growth' and 'electric field induced growth'. Compared to other methods, electric field induced growth has been considered to be a more effective and controllable method for producing well-aligned single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs). Interestingly, while the alignment of CNTs became more controllable and repeatable with the assistance of an electric field, it was also shown that for CNTs grown in an electric field, the diameter uniformity and the crystallinity of graphite sheets of CNTs were clearly improved. This led Chinese researchers to develop an electric-field-induced method to not only improve CNT uniformity but also to create a new approach to control the microstructure of CNTs.
Nov 2nd, 2006
Antibodies are large Y-shaped proteins used by the immune system to identify and neutralize foreign objects like bacteria and viruses. Each antibody recognizes a specific antigen unique to its target. That makes them valuable tools for the analysis of biomolecules in research, diagnostics and therapy. However, antibodies are huge (150 kDa) biomolecules and are not functional within a living cell due to the reductive environment of the cytoplasm. Normally, antibodies are used to detect antigens on fixed an permeabilized cells (in other words: dead cells). But neither does that provide any information about the dynamic changes of the antigen within different stages of the cell cycle, nor about its overall mobility. A research group at the University of Munich has now succeeded in developing much smaller molecules for antigen detection in living cells.
Nov 1st, 2006
The use of renewable resources (biomass) as an alternate source for fuel and the production of valuable chemicals is becoming a topic of great interest and a driving force behind research into biorefinery concepts. In the early parts of the 20th century, most nonfuel industrial products such as medicines, paints, chemicals, dyes, and fibers were made from vegetables, plant and crops. During the 1970s, petroleum based organic chemicals had largely replaced those derived from plant materials, capturing more than 95% of the markets previously held by products from biological sources. By then, petroleum accounted for more than 70% of our fuel. However, recent developments in biobased materials research show prospects that many petrochemical derived products can be replaced with industrial materials processed from renewable resources. Researchers continue to make progress in research and development of new technologies that bring down the cost of processing plant matter into value-added products. Rising environmental concerns are also suggesting the use of agriculture and forestry resources as alternative feedstock. Being able to develop soft nanomaterials and fuel from biomass will have a direct impact on industrial applications and economically viable alternatives. Researchers already have used plant-derived resources to make a variety of soft nanomaterials, which are useful for a wide range of applications.
Oct 31st, 2006
The study of very thin structural foams for cushioning and energy dissipation is, now more than ever, of primary importance in the engineering world, for example for the protection of electronic gadgets (such as MP3 players, cell phones, PDAs, etc.) from microimpacts due to accidental drops, as well as in the security area, for mitigation of explosive loading in macro scales. The advancement in the controlled growth of carbon nanotubes and other nanostructures has allowed researchers to create improved systems designed accurately for specific engineering applications.
Oct 30th, 2006
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