Showing Spotlights 1785 - 1792 of 2140 in category (newest first):
There you are - a romantic dinner for two, soft jazz music in the background, exquisite French cuisine served on finest porcelain. You are sniffing that 1986 Bordeaux you kept for this special occasion. The expensive floral bouquet that is the centerpiece of the table is warmly lit by several candles. "Wait!" you think, "wouldn't the soot from these candles make a great source of fluorescent carbon nanoparticles?" Or so works the mind of a nanoscientist. This is why they make great discoveries in nanotechnology while you and I just waste a few hours on dinner. Researchers actually have just demonstrated that fluorescent nanoparticles can be prepared from a common carbon source - candle soot. The whole process is so simple it could be carried out in a freshman chemical laboratory. So chances are the dinner actually was a midnight snack over pizza and diet coke, the music was Talib Kweli, and the mood was decidedly unromantic.
Aug 23rd, 2007
Flawed government thinking is driving a rapid expansion in the military influence over science and technology, says a new briefing from Scientists for Global Responsibility (SGR). US government spending on military research and development is soaring (up 57% since 2001), while the UK government has rolled out two new military technology strategies in the last two years. Factors such as these are contributing to an expansion of military involvement in US and UK universities. As far as nanotechnology is concerned, and as we have reported here before, the military is the largest investor in the U.S. Nanotechnology Initiative (NNI). The Department of Defense (DoD)'s share of the $6.6 billion NNI budget since the program's inception is over 30%, or $2 billion. While a part of this military research spend goes to the internal laboratories of the various parts of the armed services (navy, army, air force) and DARPA, another parts goes to universities as research grants or as part of MURI (Multi-University Research Initiative). The SGR, in its new briefing, documents how government funding for military research and development dwarfs that spent on social and environmental programs across the industrialized world. The group highlights how the military involvement in research continues to support a narrow weapons-based security agenda. SRG argues that this marginalizes a broader approach to security, which would give much greater priority to supporting conflict prevention by helping to address the roots of conflict. As part of this case, they point out how research that aims to help tackle poverty, climate change and ill-health - and thus help to provide basic security for human populations - is under-funded compared with military research.
Aug 22nd, 2007
Ion channels are proteins with a hole down their middle that are the gatekeepers for cells. Ion channels control an enormous range of biological function in health and disease. In channels with a diameter greater than 100 nm, the interaction between the channel wall and electrolyte solution hardly affects the flow of ions. When the channel diameter enters the the below-10 nm range, things change dramatically, however. Then, the interaction between the solution and channel wall starts to dominate ionic flow and ion transport through such narrow, nano-scaled channels is dominated by electrostatics. The same is true for biological ion channels where charged amino residues in the selectivity filter determine the ionic flow through the channel, along with the dielectric charge on the channel wall, and the concentrations and potential in the bulk solution. The role electrostatics play in biological pores has been confirmed by numerous mutation studies where amino acids residues in the selectivity filter were replaced by others. Ion channels have simple enough structure that they can be analyzed with the usual tools of physical science. With that analysis in hand, researchers are trying to design practical machines that use ion channels. By exploiting the electrostatics in nanochannels a group of US and Dutch scientists managed to make a diode. Like a solid-state diode allows current flow in one direction, the ionic equivalent they designed can be used to direct the flow of ions across a membrane that separates two electrolyte solutions. Now that they know how to manipulate the ion selectivity in these devices, they hope to be able one day to selectively amplify currents carried by individual chemical species - a stunning prospect for molecular nanoelectronics.
Aug 21st, 2007
The Organization for Economic Co-operation and Development (OECD) is an intergovernmental organization in which representatives of 30 industrialized countries in North America, Europe and the Asia and Pacific region, as well as the European Commission, meet to co-ordinate and harmonize policies, discuss issues of mutual concern, and work together to respond to international problems. Most of the OECD's work is carried out by more than 200 specialized committees and working groups composed of member country delegates. The OECD's Environment, Health and Safety Division has taken up the safety of nanomaterials as one of their priority issues. After several preliminary meetings in 2005 and 2006, the OECD's Chemical Committee set up a Working Party to address the health and environmental safety implications of manufactured nanomaterials (the WPMN). After a meeting in Berlin, Germany earlier this year, the WPMN has just released a document that compiles information provided by member countries and other delegations on current developments on the safety of manufactured nanomaterials in their countries or organizations and also on current activities related to nanotechnologies and nanomaterials in other International Organizations such as the International Organization for Standardization (ISO). The report makes clear that there are numerous projects and initiatives going on with regard to nanotechnology safety research. It would be nice at some point to see all these research results come together in one coherent and conclusive set of results as to where and what the risks are and how they will be controlled and managed.
Aug 20th, 2007
In the good old days, say 5,000 years ago, a bearing was simply the placement of tree trunks under the huge stone blocks that your worker army used to construct a pyramid. Since then, bearings have become a bit more sophisticated and are an essential part of much of today's machinery. Consequently, many kinds of bearings have been developed to suit particular purposes - sliding, rolling, fluid, or magnetic bearings, to name a few major categories. Bearings are now widely used for instance to reduce friction between shafts and axles or absorb the weight placed on moving parts and they are found in applications ranging from automobiles, trains and airplanes, computers, construction equipment, machine tools, to ceiling fans and roller skates. The same way that bearings have become an integral part of our modern world, they will also play an important role in the extremely miniaturized micro- and nanodevices of the future. Engineers will just have to come up with ingenuous ways to construct bearings at the nanoscale. Carbon nanotubes (CNTs) offer one possibility. Researchers have demonstrated that the relative displacements between the atomically smooth, nested shells in multiwalled carbon nanotubes (MWCNTs) can be used as a robust nanoscale motion-enabling mechanism. Even better, a group in Switzerland has demonstrated batch fabrication of such CNT bearings is possible.
Aug 17th, 2007
Self-assembly is Nature's way of building stuff. This fundamental principle that governs natural structures on all scales, from molecules to galaxies, generates structural organization from pre-existing parts or components. In nanotechnology, self-assembly is seen as a key technique that will one day allow the fabrication of materials and devices from the bottom up. Still only tinkering with the basics, scientists so far have designed and created simple systems that could mimic natural functions by connecting biological components to abiotic materials to understand the workings of the biological system or to take advantage of the unique properties of the nonbiological components in a natural setting. Most nanotechnologist, even if they manage to self-assemble functional nanodevices, still operate exclusively at the nanoscale (it will be a while before you can order "Tea. Earl Grey. Hot" from your food replicator in the wall). Bridging the gap between the nano- and the macroworld has proven to be a huge hurdle. In a novel approach that merges material chemistry, biology and medicine, researchers in Germany have used living bacteria to show that self-assembly of functional materials and living systems is possible through a chemically programmed construction.
Aug 16th, 2007
Freshwater looks like it will become the oil of the 21st century - scarce, expensive and fought over. While over 70 per cent of the Earth's surface is covered by water, most of it is unusable for human consumption. According to the Government of Canada's Environment Department (take a look at their Freshwater Website - a great resource for facts and all kinds of aspects about water), freshwater lakes, rivers and underground aquifers represent only 2.5 per cent of the world's total freshwater supply. Unfortunately, in addition to being scarce, freshwater is also very unevenly distributed. The United Nations has compared water consumption with its availability and has predicted that by the middle of this century between 2 billion and 7 billion people will be faced with water scarcity. It gets worse: In the developing countries, 80 per cent of illnesses are water-related. Due to the shortage of safe drinking water in much of the world, there are 3.3 million deaths every year from diarrheal diseases caused by E. coli, salmonella and cholera bacterial infections, and from parasites and viral pathogens. In fact, between 1990 and 2000, more children died of diarrhea than all the people killed in armed conflicts since the Second World War. The use of nanotechnologies in four key water industry segments - monitoring, desalinization, purification and wastewater treatment - could play a large role in averting the coming water crisis. But hoping that the 'magic' of nanotechnology will solve all water problems is naive - the basic problems of accessibility to technologies, affordability, and fair distribution still need to be solved.
Aug 15th, 2007
Vaccination has resulted in the eradication of smallpox and control of measles, rubella, tetanus, diphtheria, and other infectious diseases in many areas of the world (at least where vaccines are available and affordable; providing vaccines to many parts of the developing world still is one of the basic medical needs that is far from being met). The basic idea of vaccination (the word comes from the Latin vacca - cow - because the first vaccine was derived from a virus affecting cows) is to inject weakened or killed forms of pathogens such as bacteria or viruses into the body in order for the immune system to develop antibodies against them; if the same types of microorganisms enter the body again, they will be destroyed by the antibodies. About 25 years ago, the basic idea of vaccination gave rise to bactofection - the technique of using bacteria as non-viral gene carriers into target cells. The DNA cargo is transported inside the bacteria and, once it arrives at the target location, the bacteria is broken up in order to release the therapeutic gene or protein. A novel technique takes advantage of the invasive properties of bacteria for delivery of nanoparticles into cells. Here, the gene or cargo is not carried inside the bacteria, but rather remains on the surface conjugated to nanoparticles. Consequently, this approach does not require bacterial disruption for delivery, or any genetic engineering of the bacteria for different cargo.
Aug 14th, 2007