|SCIENCE TRIBUNE||Thursday, June 28, 2001, Chandigarh, India|
world of nanotechnology
How can you make very small objects? The only way we can make smaller and smaller objects is to start with a comparatively big block of material and construct various components and objects by cuttings, carving, moulding and drilling. This was the way primitive man worked but using this traditional method, industries have fabricated the vast variety of tools, from mammoth excavators to the tiniest silicon chips. There is, however, a limit to the smallest size that these techniques can make. Our methods of manufacture, whether in a machine shop or in a photo-lithographic laboratory, severely limit the smallest sizes that can be formed.
A technology where we start from the "other end", so to speak, where single atoms are brought together to form tailored molecules would in principle remove this limitation. The forces within molecules are far stronger than the forces that hold larger components together. Besides, the number of ways that molecules can be built up is very large. This, in effect, gives us an enormous information base on what structures can be built and how they behave, that is not presently available.
Some progress has been made in this very new direction. Tools such as the scanning electron microscope and the methods of supra-molecular chemistry deal with individual atoms. Scanning electron microscopes help us to put single atoms and molecules exactly as we want. Traditional chemistry has also advanced so much in recent years that we can deal with matter at the atomic levels, and this is nanotechnology.
The first application that one thinks of when nanotechnology is mentioned is to build nono-sized computers. This is because an enormous effort has been put into making computers smaller and smaller. Looking at a totally different direction, now single atoms can be moved around or fixed into desired positions in molecules to tailor custom made antibodies that fight disease and prolong life. Thus, nanotechnology can potentially solve any problem, though the beginning would naturally be in the fields of computer development and medicine. In both these areas, there is a need for manipulation on a molecular scale and in the near future may yield practical results.
In computer design, it is believed that the silicon-based circuits reduce to one quarter of the previous size every three years; this is Moore’s Law. If this trend continues, the size of the integrated circuits in mobile telephones, computers and stereo systems would end up to only a few atoms in 20 years! At present, silicon circuits are made from large wafers, after a great deal of cutting polishing, etching and plating using the latest methods of photolithography. The wavelength of the light used in photolithography limits the fineness of the etching and the best fabricating techniques use very short wavelength ultra-violet light to get a resolution of 200 nm. This traditional method is very wasteful and cannot be extended to circuits that are made up of a few atoms. A further limitation is that at these small scales of 100 nm, quantum tunneling becomes significant and the circuits become unreliable. A novel technique must therefore be developed to make integrate circuits and a lot of research and development work is going on in this direction.
The future of computer design could be either in molecular computing or in quantum computing. These two alternatives are closely related and the progress that has been achieved in both areas so far indicates that they could replace the traditional silicon chips.
Quantum computing handles information at the quantum level. At this level, particles behave like waves and waves behave like particles. A quantum state of a system can be altered by various input commands and other commands sense its properties. These are the necessary core criteria for any logic circuit in a computer. Quantum states have other properties such as the superposition of states and entanglement that have not been fully exploited and suggest that a quantum computer — single quantum bit of information could be used in several computations at the same time, a remarkable advance in parallel processing. Also, entanglement, which represents the spread of the quantum wave in space would allow information processing over long distances without wires.
Molecular computation is more prosaic. The order of the four nucleotides in a DNA molecule can be changed and the new order can be read. Each such change results in a different protein molecule. Manipulations on a set of DNA molecules can in principle therefore simulate a massive parallel-processing computer. Each DNA molecule in this machine would function as a processor, greatly improving the speed of computation. This is essential for complex problems such as weather forecasting and simulation of nuclear explosions.
Nanotechnology is useful not only for computer companies. It can now synthesise small molecules and drugs that interact with the proteins which run the machinery that keep things alive. The DNA inside the cell stores all the information to build a living cell or organism and this can be changed within the cell to alter the body’s defences. This the basis of the new science of gene therapy.
The DNA transmits this information to proteins by transcription and translation, chemical process executed by proteins and nucleic acids. Over the last 15 years, molecular biology has investigated how these processes go on and as a result new drugs have come on to the market that are extremely effective in curing disease. The recent news about the success in treating AIDS has been a fallout from molecular biology research. However, these studies directed towards designing new drugs take enormous effort and a long time under scrupulously clean conditions. As properties of most atoms in a molecular environment are fairly predictable, computers can simulate molecular systems and observe how they interact in a fraction of the time it would take to do the actual experiment in a laboratory. However such simulations require very large super computers and the software has to be extremely complex.
Another innovative technique taken
over to nanotechnology is molecular imprinting. It is known that a
molecule sticks to a surface that fits its shape, rather like a piece
in a jigsaw puzzle. The trick is then to fashion a material that takes
on a shape that is the converse of that of the molecule. The template
molecules are pressed onto the surface of silica particles with the
help of surfactants that act as glue. When the template molecule is
removed, the silica particles are coated with sites that would bind
the template molecule. In other words, the silica is tailored to be a
catalyst that captures the template molecule. This method has been
used to capture chemicals and has been of great use in pollution
control and for chemical separation. PTI
Researches are developing mechatrronic control systems, which could not only herald the end of the wiring harness but also open up a broad market for intelligent components.
Mechatronics is a new interdisciplinary branch of engineering which combines the areas of mechanical engineering, electrical and electronics engineering and information technology.
It aims to design small autonomous systems that operate intelligently and with minimal supervision, a report in Fraunhofer Gesellschaft said.
"Typical examples of its applications and advantages can be found in cars," explains Frank Ansorge of the Oberpfaffenhofen branch of the Fraunhofer Institute of Reliability and Microintegration IZM, which along with the Device Technology Department of the Fraunhofer Institute for Integrated Circuits IIS, are active in the progress of mechatronics R&D.
"Sensors detect the level of gasoline in the tank. To pass this information to the fuel guage, complex wiring harnesses are installed in the car — but they are not immune to interference," he said.
It is these long cables and researchers want to make redundant by developing integrated micro-electromechanical control devices.
With the Information Technology (IT) in India losing sheen in the wake of the economic slowdown in the USA, the focus has now shifted to the Bioinformatics hailed as the sunrise industry of the future. According to Boegre Diedrischen, Vice President of the European biotech firm Novo Nordisk, bioinformatics is one of the vital components of biotechnology that bridges the gap between biology and computers. Interestingly, these days the pharmaceutical firms around the world are increasingly falling back on the computing power to zero in on the molecules suitable for developing drugs. Against this backdrop, experts are projecting a huge demand for bioinformatics professionals in the biotechnology sector.
In order to create a pool of talented manpower to sustain the growth of bioinformatics, the Karnataka Government in association with the (ICICI has set up an) institute of bioinformatics. Though as yet one can’t figure out the manpower requirements of the bioinformatics sector, it is estimated that the number is quite staggering. Perhaps the IT professionals affected by the declining fortunes of IT industry could plump in for bioinformatics. Even so, right at the moment, an acute manpower shortage would hit the progress of bioinformatics. According to the Karnataka State Information Technology (IT) Secretary, Vivek Kulkarni, most biotech companies like Biocon and Digital train their professionals in house to meet their own requirements.
Speaking at the Bangalore Bio.com 2001, K. Sridhar, of Amershan Phamacia Biotech, firm drove home the point that bioinformatics is fundamental to the growth of biotechnology. For, bioinformatics provides the pathway for quick and accurate analysis of an enormous volume of data. Indeed, as pointed out by B. Chandershekar, Managing Director of Bigtec, "We missed the Human Genome Project and Bangalore with its expertise in IT could tap the immense potentials provided by IT".
In a development that could boost the prospects of bioinformatics, the Life Science Division of American computer giant IBM and Canada’s MDS have joined forces to speed up the discovery of drugs by analysing the complex maze of proteins within the human genome and how they factor into the onset of the disease.
As part of the strategic alliance, the health and life science company MDS will be a part of IBM’s Blue Gene Initiative, which is a five year exploratory project to create the world’s fastest computer.
IBM will provide MDS proteomics, a wholly owned subsidiary of MDS, with the super computing power necessary to crunch the store data gleaned from the analysis of how proteins trigger chemical reactions in cells. Medical scientists are optimistic that the laborious process of analysing how proteins interact with each other will give researchers the tools to understand what goes wrong in a diseased cell. IBM is potentially the most crucial element in the discovery and identifying the new targets for disease intervention", quipped MDS Proteomics Chief Executive Frank Gleeson.
The alliance will give MDS Proteomics the
computational power necessary to study proteins and build a public data base of
these proteins called BIND (Biomolecular Interaction Network Database). The
objective of the public data base is to enable universities and research
institutes store and retrieve proteomic information, with IBM providing the
hardware for the project and MDS the software. MDS Proteomics will work towards
designing and developing drugs from the proteomics research, and will also sell
"targets" — or specific data on particular proteins to its
NEW PRODUCTS & DISCOVERIES
Remember what Samuel Taylor Coleridge said: "Water, water everywhere, not a drop to drink". Well, with mounting pollution and effluents thrown into lakes and rivers the celebrated poet’s prophecy is coming chillingly true.
Which explains why more and more people are wary of drinking water straight from the tap. The preferences vary from boiled to filtered and from aerated to mineral water.
Keeping in mind the mounting demand for clean water, an American company, Corte Madera, is setting up a chain of stores in the country which would retail nothing but drinking water.
Many thought the idea would soon go down the drain but in reality, the stores are a big hit and the proprietors are saying cheers to each other.....with glasses of water, of course.
A little culture can be good for you
Children at risk from eczema and asthma may benefit from a commercially-available dose of microbes that promote "micro-flora" culture in the intestinal tract, say Finnish researchers.
The researchers at Turku University Central Hospital gave capsules of lactobacillus GG — a form of bacteria commonly found in yoghurt and cheese to pregnant women who had a family history of eczema, nasal allergies or asthma. A harmless placebo was given to a control group of women, according to an AFP report.
The women were given the choice of taking the capsules themselves or giving it to their infants for six months after they were born.
Fortysix of the 132 children delivered were found, at the age of two, to have eczema. There were also six cases of asthma and one of allergic rhinitis.
The rate of eczema among the group which had taken the lactobacillus was half that of the placebo group, the scientists found.
Researcher Marko Kalliomaki, reporting in the British medical weekly The Lancet, said the study showed that gut micro-flora "have large, yet largely unexplored properties" to prevent inflammatory diseases of the immune system. PTI
Mummy turns out to be a daddy
Sydney University scientists have discovered the world’s oldest sex change, according to an AFP report.
An Egyptian mummy, thought for 3,100 years to be a woman singer, has turned out to be a man.
"I fell of my chair when I found out," assistant curator Karin Sowada said.
The university’s museum staff believed the mummy to be woman because of the elaborately-designed coffin.
But x-rays and DNA tests reveals the true sex.
"We were able to take specimens through tiny holes without compromising the mummy, and isolate the DNA," said professor Allan spigleman of the Surgical Science Department at the University of Newcastle, who collaborated in the research.
Tests on two other mummies have revealed that a child thought to have been a girl is probably a boy and that a priest died from impacted wisdom teeth.
The mummies were brought to Australia by Sydney University’s first chancellor, Sir Charles Nicholson, in the 1850s and Sowada said the confusion over the sex arose because they were probably not in their original coffins.
1. This US chemist is known for his work in thermodynamics, valence theory (based on sharing of electrons), theory of radiation and extending the concepts of acids and bases. Name this scientist who was the first to prepare heavy water used as a moderator in nuclear reactors.
2. A spacecraft on the farthest planet of our solar system? This spacecraft, to be launched by the US Space Agency NASA in 2004, will reach Pluto in 2014 with a view to studying its atmosphere. Name this spacecraft.
3. Thanks to STM, it is now possible to take images of molecules (and thus identify them) on the surfaces of metals. This has far-reaching implications in chemical and petroleum industries and for some other uses. What is the full name of STM?
4. Bats emit waves naturally to detect objects in their surroundings. Which man-made arrangement based on a similar principle is used to detect objects in space?
5. Loose spices and pulses sold by some shopkeepers are coloured by coaltar dye, a colouring agent banned under law. What damage can the excessive use of this dye cause in human body?
6. What is a chemical reaction generally called in which the concentrations of the products and reactants keep on changing periodically, either with time or position in the reacting medium?
7. This area in a computer can temporarily store cut or copied information like text, graphics and other data. What is this area called the contents of which get erased when new information is placed on it or when the computer is shut down?
8. These birds are found in Papua New Guinea, north-eastern Australia and Muluku. Their feathers have extraordinary beautiful shapes and bright colours. They like sunlight and the male spends most of its time in trimming away the twigs and branches of the tree to enable light to pass and to attract the female. Which are these birds whose 43 species are known?
9. The basic material used in all common black inks is easily obtainable, cheap, stable to light, moisture and heat, chemically inert and has a soft texture. Which is this material?
10. Jaipur foot is an artificial foot specially suitable for Indian conditions. This artificial limb not only enables a person to walk and climb stairs but also to sit on the floor with folded legs which is not possible with other limbs. Who developed and designed this foot?
1. Gilbert Newton Lewis