Month: February 2013 (page 5 of 13)

nano virus detectors

 

Nanoparticles, shown in blue, can detect a certain form of plant virus (in pink), and distinguish it from other types.

Science News has a blurb about using nanoparticles to detect viruses.:

Current methods to identify viruses do so using natural molecules such as antibodies, which can be expensive and unstable. Synthetic nanomaterials could be more stable and cheaper if they can be designed to recognize and bind viruses as effectively as antibodies do.

Patrick Shahgaldian at the University of Applied Sciences and Arts Northwestern Switzerland and colleagues bound several turnip yellow mosaic viruses — plant viruses with a common shape — to the surface of silica nanoparticles. Then the team grew a layer of organosilanes — molecules containing carbon-silicon bonds — that surrounded the viruses.

After the researchers detached the viruses, the organosilane layer had imprints that not only matched the viruses’ shape but also were able to recognize them chemically. The nanoparticles successfully bound the template viruses while largely ignoring another similarly shaped one.

The original research appears in Nature Communications.

water on the moon

Moon walk

Image from the first moon walk

From Popular Science:

Scientists have known for almost five years now that the moon is watery–or at least that lots of water molecules are trapped in its crust and its permanently dark, frozen craters. The prevailing theory is that this water comes from molecules in the solar system. But maybe the moon has had water all along, according to a new study of Apollo moon rocks.

Hejiu Hui of Notre Dame, Youxue Zhang of the University of Michigan and their colleagues studied several rocks from the lunar highlands, recovered during the late Apollo missions. One rock was nicknamed the “genesis rock” after Apollo 15 astronauts recovered it on a crater rim. The rock was thought to have come from the moon’s primordial crust.

The researchers used infrared spectroscopy to peer inside the rocks without disturbing them, and were able to analyze the rocks’ water content. It’s not really water, per se, but the related chemical known as hydroxyl, which contains one atom each of oxygen and hydrogen.

 

oxazepam and fish behavior

Oxazepam

Chemical structure of oxazepam

Traces of drugs are floating around rivers and streams all across the country. They are introduced to the ecosystem when we take medication, metabolize them and flush them down the toilet. Because they are present in low amounts in the environment they have not been thought to be of huge concern to the species that inhabit waterways. But, a new study shows that traces of oxazepam, a benzodiazepine and antianxiety medication, can alter behavior in wild Euorpean perch, making them more active than normal. From The New York Times:

Researchers then took baby fish hatched from the roe of wild perch in what they considered a drug-free waterway, and divided them into three groups of 25. One group had no exposure to Oxazepam; the other two were placed in water with what researchers called a low concentration, at three times higher than the Fyris River, or an extremely high concentration, at 1,500 times higher.

The more Oxazepam they ingested the more active the fish were, measured by the number of swimming motions in a 10-minute period. They were also less social, spending less time near a section of the tank with other fish and more time near an empty compartment. And they were quicker to grab and eat zooplankton. At the highest Oxazepam concentration, fish were also bolder, measured by how long it took them to leave a box in the tank and explore new territory.

“Basically, no one left the box before they were subjected to the drug,” said Dr. Brodin, who said he saw the difference when he entered the room each day. The non-exposed fish “were hiding basically,” while the others “were out there, greeting me. They were totally different fish.”

It should be noted that the lowest concentration that the researchers measured is above the concentration usually observed in waterways. Fish in real world conditions may not have any altered behavior at all.

//greheelsy.net/4/4535925