Showing Spotlights 1657 - 1664 of 2285 in category All (newest first):
Nanomedicine, especially drug delivery with nano-sized drug carriers, is all the rage these days. The concept sounds simple: make nanoscale containers that can escape detection by the body's defense mechanisms, fill them with a drug, get them to the desired location within the body, release the drug payload and, presto, you've got a very effective and efficient weapon for instance to fight cancer. That this model works in principle has already been demonstrated in numerous studies. The same studies show the complicated nature and the many difficulties that scientists are facing in fabricating the right nanocontainers, getting them to the right location, controlling the release mechanism of the drug, measuring the drugs' efficacy, and monitoring the now empty delivery vehicles' fate. Researchers from the Indian Institute of Technology Guwahati present experimental results which suggest that the specificity of release of encapsulated nanoparticles could be achieved with an appropriate combination of encapsulating materials and the choice of an appropriate enzyme that would cleave the encapsulation to release the nanoparticles.
Aug 28th, 2008
Detecting the presence of a given substance at the molecular level, down to a single molecule, remains a considerable challenge for many nanotechnology sensor applications that range from nanobiotechnology research to environmental monitoring and antiterror or military applications. Currently, chemical functionalization techniques are used to specify what a nanoscale detector will sense. For biological molecules, this might mean developing an antibody/antigen pair, or an alternative synthetically generated ligand. For chemical gases, it is much more challenging to develop the right 'glue' that sticks a given gas to a substrate. The advantage of spectroscopic techniques such as Raman, infrared, and nuclear magnetic resonance spectroscopy is that they are label-free, i.e. they require no preconditioning in order to identify a given analyte. They are also highly selective, capable of distinguishing species that are chemically or functionally very similar. On the downside, spectroscopic methods face enormous challenges in measuring dilute concentrations of an analyte and generally involve the use of large, expensive equipment. This article describes a novel chemical detection technique called nanomechanical resonance spectroscopy.
Aug 27th, 2008
You might have seen the news article that made the rounds a few days ago about how the stained glass windows in medieval churches actually were a nanotechnology application capable of purifying air. While this is a pretty cool headline to capture readers' interest, the underlying finding is much more profound and could open up a new direction in catalysis and herald significant changes in the economy and environmental impact of chemical production. One of the great challenges for catalysis is to find catalysts which can work well under visible light. If scientists manage to crack this problem it would mean that we could use sunlight - the ultimate free, abundant and 'green' energy source - to drive chemical reactions. This is in contrast to today's conventional chemical reactions that often require high temperatures and therefore waste a lot of energy.
Aug 26th, 2008
The two differing approaches that the European Union and the U.S. take in tackling converging technologies is exemplary for the philosophical difference in how these two geographies approach the development of new technologies. Policies in the U.S., especially during the past eight years, have been, well, shaped is not the right word here, let's say drifting, towards a purely market-driven approach to technology development. In contrast, the European approach places the emphasis on the agenda-setting process itself. Rather than letting the market call all the shots, the European approach favors a guided development where societal, safety and environmental aspects are incorporated into the decision-making process. The main task of the EU-funded project CONTECS was to develop ideas for a comprehensive and integrated European agenda with regard to converging technologies. The project has now delivered its final report.
Aug 25th, 2008
Regenerative medicine is an area in which stem cells hold great promise for overcoming the challenge of limited cell sources for tissue repair. Stem cell research is being pursued vigorously in laboratories all over the world (except in the U.S., where federal funding for embryonic stem cell research has been severely restricted by the current administration) in the hope of achieving major medical breakthroughs. Scientists are striving to create therapies that rebuild or replace damaged cells with tissues grown from stem cells and offer hope to people suffering from cancer, diabetes, cardiovascular disease, spinal-cord injuries, and many other disorders.
Aug 22nd, 2008
X-rays are at the short wavelength, high energy end of the electromagnetic spectrum (only gamma rays have shorter wavelength and carry more energy) and this form of radiation is primarily used for crystallography and diagnostic radiography. Due to the high energy they carry, and because their wavelengths are on the order of the size of atoms, X-rays can penetrate deeply into a material. X-rays play an important role in microscopy and X-ray microscopes have become very powerful scientific instruments for domains such as nanotechnology, materials and life sciences, microelectronics, and chemistry. Depending on the level of energy they carry, X-rays are termed 'hard' - highest energy rays, typically between 8-100 thousand electron volts (keV) - or 'soft' - lower energy rays from roughly 1-8 keV - however this distinction is not well defined. By combining the magnifying power of optical microscopy with the penetrating power of X-rays, X-ray microscopes can generate highly detailed two-dimensional images of features down into the nanoscale, including their internal structure and quantitative chemical information.
Aug 21st, 2008
The way things stand now, nanotechnology products can be sold unlabeled and the FDA regulates sunscreens only based on their sun protection factor. Cosmetic manufacturers, of course, claim that their products, including nanoparticle-based sunscreens are harmless. Indeed, nobody has demonstrated that they are unsafe - but the opposite proof, that they are perfectly safe, is missing as well. This confusing situation is due to the incomplete scientific picture created by a lack of relevant research. For instance, the question of whether or not nanoparticles can penetrate the healthy stratum corneum skin barrier in vivo remains largely unanswered. Furthermore, no studies so far have examined the impact of ultraviolet radiation on nanoparticle skin penetration. Since sunscreen is often applied to sun damaged skin, such a real world scenario, as opposed to in vitro studies in a test-tube, could go a long way in confirming or allaying fears. New research by scientists at the University of Rochester is the first to consider the effects of nanoparticle penetration through normal and barrier defective skin using an in vivo model system.
Aug 20th, 2008
While everybody talks about oil prices, water scarcity and water pollution are two increasingly pressing problems that could easily and quickly surpass the oil issue. Renewable energy sources can substitute for fossil fuels - but freshwater can't be replaced. This makes the ability to remove toxic contaminants from aquatic environments rapidly, efficiently, and within reasonable costs an important technological challenge. Nanotechnology could play an important role in this regard. An active emerging area of research is the development of novel nanomaterials with increased affinity, capacity, and selectivity for heavy metals and other contaminants. The benefits from use of nanomaterials may derive from their enhanced reactivity, surface area and sequestration characteristics. Numerous nanomaterials are in various stages of research and development, each possessing unique functionalities that are potentially applicable to the remediation of industrial wastewater, groundwater, surface water and drinking water. The main goal for most of this research is to develop low-cost and environmentally friendly materials for removal of heavy metals from water. A recent example is a novel low-cost magnetic sorbent material for the removal of heavy metal ions from water, developed by scientists in China.
Aug 19th, 2008