Showing Spotlights 2665 - 2672 of 2837 in category All (newest first):
Controlling the shape of nanostructures is one of the challenging issues presently faced by synthetic chemists and materials engineers. Various shapes of nanomaterials, such as sphere-, rod-, wire-, triangle-, cube-, and tube-outlines have been synthesized by various approaches. However, to produce nanostructures with high monodispersity is still one of the major issues to be solved. Most work in this area focused on inorganic or synthetically organic materials. Using pure biomolecules to produce nano- or micro-structures, without the assistance of inorganic materials, is rare. Biocompatible nanospheres have been and remain of intense interest for biosensor, drug delivery, and biomedical contrast imaging. A new research report coming out of China now shows that highly monodispersed nanospheres of cystine (a sulfur-containing amino acid) aggregate were successfully produced by a quite simple method without the assistance of any other inorganic materials. This work could be of great significance in the production of nanomaterials, biosensors, and drug delivery.
Oct 17th, 2006
As the semiconductor industry continues to miniaturize in following Moore's Law, there are some real challenges ahead, particularly in moving deeper and deeper into the nano length scale. In particular, sustaining the traditional logic MOSFET (metal-oxide-semiconductor field-effect transistor) structure, design, and materials composition will be especially difficult, particularly beyond the 22 nm node. Nanocables, consisting of a range of materials, offer potential solutions to these problems and may even be an alternative to today's MOSFET. A group of researchers from several European countries now reports the synthesis of a magnetically tunable nanocable array, combining separate hard and soft magnetic materials in a single nanocable structure. The combination of two or more magnetic materials in such a radial structure is seen as a very powerful tool for the future fabrication of magnetoresistive, spin-valve and ultrafast spin-injection devices with nonplanar geometries.
Oct 16th, 2006
With the advent of nanoscience and technology, a new area has developed in the area of textile finishing called "Nanofinishing". Growing awareness of health and hygiene has increased the demand for bioactive or antimicrobial and UV-protecting textiles. Coating the surface of textiles and clothing with nanoparticles is an approach to the production of highly active surfaces to have UV blocking, antimicrobial, flame retardant, water repellant and self-cleaning properties. While antimicrobial properties are exerted by nano-silver, UV blocking, self-cleaning and flame-retardant properties are imparted by nano-metal oxide coatings. Zinc oxide (ZnO) nanoparticles embedded in polymer matrices like soluble starch are a good example of functional nanostructures with potential for applications such as UV-protection ability in textiles and sunscreens, and antibacterial finishes in medical textiles and inner wears.
Oct 13th, 2006
Semiconductor photonics, electronics and optoelectronics infrastructure is at the core of the information society. As the length scales of electronic devices continue to shrink, the cost of traditional approaches to device fabrication involving lithography is becoming excessive. It is regarded that self-assembled growth methods are a solution to the problem of fabricating smaller devices at a lower cost. Self-assembled quantum dots (QDs) are providing the possibility of new devices for this infrastructure in the short, medium and long term. QDs are ideal for the study of the fundamental properties of nanostructures, which is applicable across the nanotechnology and nanoscience sector. Research in self-assembled semiconductor QDs is therefore characterized by a remarkably well-matched combination of the two main motivations for scientific research, namely academic interest and the potential for industrial applications. As a consequence, there is an intense scientific activity in materials growth, structural characterization, optical and transport spectroscopy, device engineering and computational modeling. The field of self-assembled semiconductor nanostructures started in 1985 in Europe by a French group at the Centre National d'Etudes des Telecommunications - CNET.
Oct 12th, 2006
DNA computing is a form of computing which uses DNA and molecular biology instead of the traditional silicon-based computer technologies. Molecular computation is currently focused on building molecular networks analogous to electrical engineering designs. These networks consist of logic gates, which perform Boolean logical operations such as AND, NOT, and OR on one or more inputs to produce an output. While individual molecular gates and small networks have previously been constructed, these gates are yet to be integrated at higher levels of complexity. Such integration in electrical engineering arises from massive parallelism and interconnections, rather than fundamental component complexity. The ability to truly integrate molecular components remains crucial for the construction of next-generation molecular devices. Researchers have now succeeded in building a medium- scale integrated molecular circuit, integrating 128 deoxyribozyme-based logic gates, 32 input DNA molecules, and 8 two-channel fluorescent outputs across 8 wells.
Oct 11th, 2006
Anthrax is an acute infectious disease caused by the bacteria Bacillus anthracis and is highly lethal in some forms. Anthrax spores can and have been used in biological warfare. "Weaponizing" the spores requires a process to make an aerosol form of anthrax so that they easily can enter the lungs. Inhalation is the most lethal form of anthrax infection. Consequently there has been significant interest in the surface structure and characteristics of anthrax spores as related to their binding by molecular species. The investigation of such binding is obviously important to the development of countermeasure technologies for the detection and decontamination of anthrax spores. A group of researchers at Clemson University have come up with an agent that clings to the anthrax spores to make their inhalation into the lungs difficult.
Oct 10th, 2006
Fuel cells are electrochemical energy conversion devices for the direct conversion of the chemical energy of a fuel into electricity. They are among the key enabling technologies for the transition to a hydrogen-based economy. Of several different types of fuel cells under development today, polymer electrolyte fuel cells (PEFCs) have been recognized as a potential future power source for zero emission vehicles. However, to become commercially viable, PEFCs have to overcome the barrier of high catalyst cost caused by the exclusive use of platinum and platinum-based catalysts in the fuel-cell electrodes. Researchers at Los Alamos National Laboratory now demonstrate a new class of low cost (non-precious metal)/(heteroatomic polymer) nanocomposite catalysts for the PEFC cathode, capable of combining high oxygen-reduction activity with good performance durability. The results of their study show that heteroatomic polymers can be used not only to stabilize the nonprecious metal in the acidic environment of the PEFC cathode but also to generate active sites for oxygen reduction reaction.
Oct 6th, 2006
Because of the huge effective surface area, the ability to blend different types of polymers, and the fact that the process is conducted at room temperature so that biological compounds can be loaded into the fibers, electrospinning has enormous potential to create new families of higher performance products across a wide array of industry sectors. For a technique invented in 1934, we are just now beginning to see its true potential.
Oct 5th, 2006
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