LilaG writes: Antibiotic resistance genes are cheap, powerful tools for biologists. But now researchers have found evidence that those very genes used in molecular biology and genetic engineering experiments may have reached the environment. In six Chinese rivers, researchers found bacterial DNA carrying these synthetic genes.
Still, other experts call for more studies to confirm the results and pinpoint specific sources of the genes.
LilaG writes: Forget gold-plated teeth. Gold-nanoparticled hair may just be the next cool thing. Researchers in Paris have discovered that they can produce gold nanoparticles within strands of hair that will dye white hair gold. Added bonus: the hair glows red when blue light shines on it.
Alas, don't expect to see gold nanoparticle dye coming to your hair salon anytime soon. The process takes days of treatment to produce the full effect. Another downside: the process uses a very strong base, with pH 12.5, making it far more caustic than a perm.
That's the conclusion of a study by researchers in Alabama who were already studying the region's oysters before the spill happened — giving them before, during, and after samples to test. Using isotopic ratios, the researchers found little evidence of oil in the oyster's flesh or shells.
LilaG writes: You may choose blue or black ink, but some scientists want to "write" with bacterial ink. Now they can, thanks to researchers in South Korea.
An article in Chemical and Engineering News describes the researchers' adaptation of dip-pen nanolithography, allowing the researchers to write dots of E. coli with control over placement of the dots and over the number of organisms in each dot.
LilaG writes: Decades of mountaintop-removal mining may have harmed aquatic life along more than 1,700 miles of streams in southern West Virginia, according to new research. Mining companies have converted 5% of the region to mountaintop mines. The resulting water pollution has caused so many sensitive insect species to vanish that 22% of streams may qualify as impaired under state criteria, the researchers report.
LilaG writes: Drug tests spot banned substances based on their chemical structures, but a new breed of narcotics is designed to evade such tests. These synthetic marijuana drugs, found in "herbal incense," are mere chemical tweaks of each other, allowing them to escape detection each time researchers develop a new test for one of the compounds. Now chemists have developed a method that can screen for multiple designer drugs at once, without knowing their structures. The test may help law enforcement crack down on the substances.
The researchers used a technique called "mass defect filtering," which can detect related compounds all at once. That's because related compounds have almost equal numbers to the right of the decimal point in their molecular masses.
The researchers tested their technique on 32 herbal products with names like "Mr. Nice Guy" and "Hot Hawaiian." They found that every product contained one or more synthetic cannabinoid; all told, they identified nine different compounds in them — two illegal ones and seven that are not regulated.
LilaG writes: Who hasn't marveled at the ability of water bugs to skate along the surface of lakes and ponds? Now materials scientists in China have taken a cue from water striders and created a device that can coast along the surface between oil and water.
The tricky part was figuring out how to make an oil-repelling surface that worked underwater. It came down to coating copper wires with copper oxide microstructures that look like flowers made up of nanopetals.
Scientists think such coatings could enable robots that clean up oil spills, bug-proof car windshields, and ship hulls that don't build up barnacles.
The molecule is currently in late-stage clinical trials to treat chronic myeloid leukemia. Pfizer, the company sponsoring the human trials, says patients have only received the genuine article.
But just before publishing a paper on the molecule, which is used in basic and medical research, scientists at Stanford discovered that the compound they were working with--which they thought was bosutinib, and had ordered from a vendor--wasn't.
“We had wasted a huge amount of time and money on the wrong isomer,” one of the scientists says. Many other researchers may face the same problem. Perhaps the published literature is full of incorrect results based on the isomer instead of bosutinib itself.
LilaG writes: To develop new materials for robotics, scientists have developed graphene-based actuators that convert electricity into motion. In robots, actuators act like muscles, driving the movement of mechanical arms and fins. Most actuator materials, such as ceramics and conductive polymers, respond slowly, require a lot of power, or provide very little force. To make speedy, strong actuators, Chinese researchers coated graphene paper with the polymer polydiacetylene. Graphene provides a highly conductive, flexible backing for the fragile polymer crystals, which deform in response to electrical current. The actuators can bend 200 times per second and generate more force than most current materials. Using a sheet of the material, the scientists built a simple inchworm robot that arches and relaxes to crawl forward.
LilaG writes: Mycoplasmas are the smallest organisms known, tiny bacteria that most antibiotics don't kill. They also are a worrisome laboratory contaminant, infecting an estimated 15-70 percent of all mammalian cell cultures. They can change cell behavior, making healthy cells look cancerous, or otherwise mucking up research results. Now researchers at Harvard Medical School have made the most of an accidental contamination: they've developed a glowing assay for mycoplasmas.
They did by noticing that an assay for tumor growth gave inconsistent results across cell lines, and realizing the cause was mycoplasma growth in some of their cells. The same assay, an enzyme called Gaussia luciferase, can detect even very low concentrations of mycoplasmas.
LilaG writes: Chemists in China have precisely grown arrays of ultrathin flakes of bismuth selenide and bismuth telluride on a surface. The bismuth compounds belong to a recently discovered – and weird — class of materials called topological insulators, which conduct electrons only along their surfaces, not through their insides.
Researchers think topological insulators promise a new realm of fast, energy-efficient electronic and spintronic devices. Making well-defined nanoparticle arrays such as the new study’s flakes is a key step towards such devices.
LilaG writes: Chicken feathers processed at high temperatures become “feather meal” that finds use as fertilizer and animal feed. But the feathers retain a slew of pharmaceutical compounds, and not just drugs used to treat chickens, researchers report. They discovered antibiotics, fungicides, caffeine, and other compounds in feather meal.
As with "biosolids" (derived from human and animal waste) that are used in agriculture, feather meal may provide a conduit for drugs to get into the environment and foster antimicrobial resistance.
LilaG writes: In the past, scientists have synthesized star-shaped nanoparticles but no one has been able to make them shaped like star fruits. Until now. Researchers at Rice University started with gold nanorods that are pentagonal in cross section. They then coated more gold onto each of the corners to create star-fruit shapes. Pretty micrographs! The particles aren’t just nifty, they could have a useful application: improving results from a spectroscopic technique called SERS (surface-enhanced Raman spectroscopy). The research paper (abstract) appears in the journal Langmuir.
LilaG writes: Drugmakers rely on many analytical instruments when they screen for potential drug candidates. Now they may want to invest in headphones, Chemical & Engineering News reports. Researchers at Australia’s University of Queensland have developed a sensor that uses the sound generated by a vibrating crystal to measure properties of common drugs (abstract). The sensor’s quartz crystal microbalance can measure candidate drugs’ pKa, or acid dissociation constant, and partition coefficient, or affinity for fats. Since these characteristics help predict how well the body absorbs molecules, the acoustic sensor may offer a new way for drug developers to quickly assess candidate molecules.