GEN-ERIC News

Stem cells normally associated with potential cures and treatments can also promote the spread of cancer, scientists have shown. A study found that stem cells taken from bone marrow can drive breast cancer cells to invade other parts of the body. The good news is that the process is reversible, and understanding it may open the door to ways of reducing the metastasis, or spread, of cancer. Stem cells are immature cells not yet assigned a function that can develop into different kinds of tissue. Scientists hope in future they will be used to treat a host of diseases ranging from Parkinson’s to heart failure and type 1 diabetes. Mesenchymal stem cells (MSCs) are a type of stem cell from the bone marrow that can generate connective tissue, bone, fat, cartilage and muscle. The new research showed that when MSCs are mixed with human breast tumour cells they dramatically increase the potential of the cancer cells to metastasise.

A plant-like micro-organism mostly found in oceans could make the manufacture of products, from iridescent cosmetics, paints and fabrics to credit card holograms, cheaper and ‘greener’. The tiny single-celled ‘diatom’, which first evolved hundreds of millions of years ago, has a hard silica shell which is iridescent – in other words, the shell displays vivid colours that change depending on the angle at which it is observed. This effect is caused by a complex network of tiny holes in the shell which interfere with light waves. UK scientists have now found an extremely effective way of growing diatoms in controlled laboratory conditions, with potential for scale-up to industrial level. This would enable diatom shells to be mass-produced, harvested and mixed into paints, cosmetics and clothing to create stunning colour-changing effects, or embedded into polymers to produce difficult-to-forge holograms. Manufacturing consumer products with these properties currently requires energy-intensive, high-temperature, high-pressure industrial processes that create tiny artificial reflectors. But farming diatom shells, which essentially harnesses a natural growth process, could provide an alternative that takes place at normal room temperature and pressure, dramatically reducing energy needs and so cutting carbon dioxide emissions. The process is also extremely rapid – in the right conditions, one diatom can give rise to 100 million descendants in a month.

“Knot formation is important in many fields,” said Douglas Smith, an assistant professor of physics who was the senior author on the paper. “For example, knots often form in DNA, which is a long string-like molecule. Cells have enzymes that undo the knots by cutting the DNA strands so that they can pass through each other. Certain anti-cancer drugs stop tumor cells from dividing by blocking the unknotting of DNA.” Dorian Raymer, a research assistant working with Smith, initiated the study because he was interested in knot theory—the branch of mathematics that uses formulae to distinguish unique knots. “Very little experimental work had been done to apply knot theory to the analysis and classification of real, physical knots,” said Smith. “For mathematicians, the problem is very abstract. They imagine the types of knots that can form and then classify them. In our experiments, we produced thousands of different knots, used mathematical knot theory to analyze them, and then developed a simple physics model to explain our findings.” The experimental set up consisted of a plastic box that was spun by a computer-controlled motor. A piece of string was dropped into the box and tumbled around like clothes in a dryer. Knots formed very quickly, within 10 seconds. The researchers repeated the experiment more than 3,000 times varying the length and stiffness of string, box size and speed of rotation. They classified the resulting knots. “It is virtually impossible to distinguish different knots just by looking at them,” said Raymer. “So I developed a computer program to do it. The computer program counts each crossing of the string. It notes whether the crossing is under or over, and whether the string follows a path to the left or to the right. The result is a bunch of numbers that can be translated into a mathematical fingerprint for a knot.

Engineers have shown how to grow forests of tiny cylinders called carbon nanotubes onto the surfaces of computer chips to enhance the flow of heat at a critical point where the chips connect to cooling devices called heat sinks. The carpetlike growth of nanotubes has been shown to outperform conventional “thermal interface materials.” Like those materials, the nanotube layer does not require elaborate clean-room environments, representing a possible low-cost manufacturing approach to keep future chips from overheating and reduce the size of cooling systems, said Placidus B. Amama, a postdoctoral research associate at the Birck Nanotechnology Center in Purdue’s [profile] Discovery Park. Researchers are trying to develop new types of thermal interface materials that conduct heat more efficiently than conventional materials, improving overall performance and helping to meet cooling needs of future chips that will produce more heat than current microprocessors. The materials, which are sandwiched between silicon chips and the metal heat sinks, fill gaps and irregularities between the chip and metal surfaces to enhance heat flow between the two.

“Education is what survives when what has been learned has been forgotten.”

With atoms and molecules in a gas moving at thousands of kilometres per hour, physicists have long sought a way to slow them down to a few kilometres per hour to trap them. A paper, published today in the Institute of Physics’ New Journal of Physics, demonstrates how a group of physicists from The University of Texas at Austin, US, have found a way to slow down, stop and explore a much wider range of atoms than ever before. Inspired by the coilgun that was developed by the University’s Center for Electromechanics, the group has developed an “atomic coilgun” that slows and gradually stops atoms with a sequence of pulsed magnetic fields. Dr. Mark Raizen and his colleagues in Texas ultimately plan on using the gun to trap atomic hydrogen, which he said has been the Rosetta Stone of physics for many years and is the simplest and most abundant atom in the periodic table.

“An adult-store owner had asked the justices to throw out the law as an unconstitutional intrusion into the privacy of the bedroom. But the Supreme Court declined to hear the appeal, leaving intact a lower court ruling that upheld the law.
Sherri Williams, owner of Pleasures stores in Huntsville and Decatur, said she was disappointed, but plans to sue again on First Amendment free speech grounds. “My motto has been they are going to have to pry this vibrator from my cold, dead hand. I refuse to give up,” she said. Alabama’s anti-obscenity law, enacted in 1998, bans the distribution of “any device designed or marketed as useful primarily for the stimulation of human genital organs for anything of pecuniary value.”