Stories tagged detection

Jan
24
2013

Sniffing Out Cancer: Amherst chemists develop a way to "smell" cancer cells.
Sniffing Out Cancer: Amherst chemists develop a way to "smell" cancer cells.Courtesy Jeremie63
Chemists from the University of Massachusetts Amherst have developed a way to quickly and accurately detect and identify metastatic cancer cells in living tissue, in much the same way that your nose can detect and identify certain odors.

The smell of a rose, for example, is a unique pattern of molecules, which activates a certain set of receptors in your nose. When these specific receptors are triggered, your brain immediately recognizes it as a rose.

Similarly, each type of cancer has a unique pattern to the proteins that make up its cells. The Amherst chemists just needed a "nose" to recognize these patterns. What they came up with was an array of gold nanoparticle sensors, coupled with green fluorescent proteins (GFP). The researchers took healthy tissue and tumor samples from mice, and trained the nanoparticle-GFP sensors to recognize the bad cells, and for the GFP to fluoresce in the presence of metastatic tissues.

This method is really sensitive to subtle differences, it's quick (can detect cancer cells within minutes), it can differentiate between types of cancers, and is minimally invasive. The researchers haven't tested this method on human tissue samples yet, but it holds some exciting potential.

Jan
17
2010

Finally, an objective test for autism

Magnetoencephalography (MEG): A scanner that detects magnetic fields in the brain.
Magnetoencephalography (MEG): A scanner that detects magnetic fields in the brain.Courtesy Tom Holroyd
Diagnosing autism spectrum disorders (ASD), up until now, has been subjective. No hard evidence, like a blood test or some other machine measurement could be used to verify ASD.

Researchers now hope that by scanning brainwaves, early recognition and treatment might be possible. Autism spectrum disorders, which includes Aspergers, is now being found in about one per cent of the (US) population.

In the current study, published in the journal Autism Research, Dr Roberts used a magnetoencephalography (MEG), a scanner that detects magnetic fields in the brain.
The children with ASDs had an average delay of 11 milliseconds (about 1/100 of a second) in their brain responses to sounds, compared to the control children. Telegraph.co.uk

Sep
06
2009

Nano technology makes detecting lung cancer easy and affordable

Breathalyzer
BreathalyzerCourtesy mrjorgen
The breath of people who have lung cancer is different than those who don't. For years scientists have been perfecting techniques that determines what exactly is different.

Expensive and complicated tools like gas chromatographs and mass spectrometers were used to identify and measure 42 volatile organic compounds that represent lung cancer biomarkers. Sensors were designed to react to four of these compounds.

Gang Peng of the Israel Institute of Technology in Haifa and colleagues have now developed what they say is an inexpensive, portable sensor technology that can quickly distinguish between the breath of lung cancer patients and healthy people. New York Times

How lung cancer detectors work

Tiny gold nano size beads were coated with organic compounds that would react with the four lung cancer biomarkers. The particles were deposited as a thin film between two electrodes. The breath of someone with lung cancer reacts with the chemicals in the gold beads, changing their electrical resistance.

Learn more

Physics World has a more complete explanation of how gold nano beads sense lung cancer.

The abstract of the research paper titled "Diagnosing lung cancer in exhaled breath using gold nanoparticles can be found in Nature Nanotechnology.

Jul
26
2007

Scent of death?: A Providence, R.I., cat, (not pictured above) that lives at a nursing home has an uncanny ability to find and curl up by residents who are about to die. (Photo by grafwilliam)
Scent of death?: A Providence, R.I., cat, (not pictured above) that lives at a nursing home has an uncanny ability to find and curl up by residents who are about to die. (Photo by grafwilliam)
This has been the main topic of side conversations of floor staff members at the museum today.

Have you heard about this cat in a Providence, R.I., nursing home that has correctly identified the last 25 patients who were to die there?

Oscar, the cat, makes the rounds of the nursing home each morning, just like the medical staff. Some mornings, Oscar will then slip into a room, curl up next to an ailing patient. Within several hours, that patient dies. The cat is so accurate, nursing home staff members will call the family of a resident being visited by Oscar so that they can be present when their loved one passes away.

“He seems to understand when patients are about to die,” says Dr. David Dosa. “Many family members take some solace from it. They appreciate the companionship that the cat provides for their dying loved one.”

Before you get too creeped out by this, doctors at the nursing home say that most of the people Oscar visits are so sick, they’re not aware that he is there. And families, for the most part, seem to be pleased that their loved one got some special attention from Oscar before the death.

Is there science behind this phenomenon? After all, there are dogs that can sniff out oncoming epileptic seizures and there are rats that can sniff out buried land mines.

One theory is that Oscar picks up scents or reads something into the behavior of the nurses who raised him in being able to determine if a patient is going to die. One researcher points out that the only way to know for sure is to do a study of Oscar’s behavior when someone is dying compared to what he does when people aren’t dying.

What do you think is going on here? Share your thoughts with other Science Buzz readers.

Being one never to have a lot of trust in cats, especially after seeing the movie "Cats and Dogs, I’d like that investigation to go a little deeper. Cats can be a lot more devious than appears on the surface.

Bee driven sensors: Courtesy Susana Soares.
Bee driven sensors: Courtesy Susana Soares.
An artist at the Royal College of Art in the United Kingdom has designed some beautiful glass sculptures that could help use bee's amazing powers of smell to help detect disease. Susana Soares was inspired by recent news on research to use bees to sniff out chemical weapons and bombs.

Also check out:

University of Montana's Bee Alert program.
More on bees from Science Buzzzzzz

Oct
10
2006

Nuclear test detection: photo from wikimedia
Nuclear test detection: photo from wikimedia

Was N. Korean nuclear test a dud?

James Acton of Vertic, an independent non-governmental organisation (NGO) in London that specialises in verification research, noted enormous discrepancies in the estimated size of the blast.

“I’ve heard from three different sources that it (the North Korean blast) was less than one kilotonne,” “If it turns out to be less than a kilotonne, it could look very much like a fizzle,” a bomb that failed to detonate properly and achieve a full chain reaction," said Acton, a nuclear physicist by training. Kahleej Times.

Russian Defence Minister Sergei Ivanov, however, has been quoted as saying that the nuclear device tested by North Korea ranged between five and 15 kilotons. That is the normal size of a successful test.

What data, besides seismic, can be used?

  • In addition to seismic sensors run by national governments, the UN’s Comprehensive Nuclear-Test-Ban Treaty Organisation (CBTO) in Vienna also has a network of 189 seismic and hydroacoustic monitoring stations designed to detect nuclear tests.
  • Radioactive particles and gases that can vent from an underground nuclear blast are also a telltale, providing clues as to the type of material (uranium or plutonium) that was used and to the size of the weapon.
  • A third monitoring technique is to use satellites with ground-scanning radars, which record the topography of a test site before and after an event. Movement or subsidence of the soil is the sign of a big blast.

How do we tell if it was a nuclear explosion?

Like earthquakes, large explosions send out shockwaves that can be detected on seismographs. Big nuclear bombs make big waves, with clear signatures that make them fairly easy to detect, analyze and confirm that they were caused by splitting atoms. But smaller blasts - as North Korea's appears to have been - are trickier to break down. York Daily Record

A nuclear explosion has a more instant shockwave than a chemical one. The differences between regular bombs and a nuclear explosion are very fine and subtle, and you need time to analyse the signatures.

"People have different way of cross cutting the data and interpreting them,"
The CTBTO's stations are more extensive than those used by most countries. They monitor seismic events but also underwater data, radioactive particles in the air and radiowaves.
"Within 72 hours we will have full data. Then all this will be available to member states," said Lassina Zerbo, director of the International Data Center at the CTBTO, which is based in Vienna, Austria.

While the North Korean explosion was small, potentially complicating monitoring efforts, sensors in South Korea were likely close enough to categorize it as nuclear, if that is what is was, said Friedrich Steinhaeusler, professor of physics at Salzburg University.

A nuclear blast also gives off a clear signature - a clear graph of peaks and curves - that differentiates it from other kinds of shocks, he added.

"We'll have the confirmation soon," he said.

Additional reading can be found on Rueters.
For updates I recommend this Wikipedia page

Mar
12
2005

The USGS, the branch of our government that reports and monitors earthquakes, reported a small earthquake in southern Florida yesterday. Well, at least that's what they thought. Residents of the Tampa, Florida area felt strong shocks and sounds of explosions last night and many thought it might have been an earthquake too. But Florida doesn't usually experience these sorts of tremors. The military later released a statement saying that two F-18 fighter jets flying low and then landing at an area Air Force base created the shocks. But, is that the whole story?