Monthly Archives: September 2015

An easier, cheaper way to diagnose Ebola

Leave a reply

A Sept. 9, 2015 news item on Nanotechnology Now highlights a new technology for diagnosing the Ebola virus,

A new Ebola test that uses magnetic nanoparticles could help curb the spread of the disease in western Africa. Research published in Biosensors and Bioelectronics shows that the new test is 100 times more sensitive than the current test, and easier to use. Because of this, the new test makes it easier and cheaper to diagnose cases, enabling healthcare workers to isolate patients and prevent the spread of Ebola.

The authors of the study, from the Chinese Academy of Sciences, say their new technology could be applied to the detection of any biological molecules, making it useful to diagnose other infectious diseases, like flu, and potentially detect tumors and even contamination in wastewater.

A Sept. 9, 2015 Elsevier press release, which originated the news item, provides more detail,

The Ebola virus causes an acute illness that is deadly in half of all cases, on average. The current outbreak of Ebola, which started in March 2014, affects countries in west Africa. In the most severely affected countries, like Guinea, Liberia and Sierra Leone, resources are limited, making control of the outbreak challenging. There is no vaccine for Ebola, so detecting the virus is key to controlling the outbreak: with an accurate diagnosis, patients can be isolated and treated properly, reducing the risk of spread.

“In west Africa, resources are under pressure, so complicated, expensive tests are not very helpful,” said Professor Xiyun Yan, one of the authors of the study from the Chinese Academy of Sciences. “Our new strip test is a simple, one-step test that is cheap and easy to use, and provides a visible signal, which means people don’t need training to use it. We think it will be especially helpful in rural areas, where technical equipment and skills are not available.”

Currently there are two ways to test for the Ebola virus: using a method called polymerase chain reaction (PCR), which makes copies of the molecules for detection, and with antibody-capture enzyme-linked immunosorbent assay (ELISA), which gives a visual indication when a given molecule is in a sample. PCR is very sensitive, but is expensive and complicated, requiring special skills and technical equipment. The ELISA – or gold strip test – is cheaper but sensitivity is very low, which means it often gives the wrong results.

The new test, called the nanozyme test, uses magnetic nanoparticles, which work like enzymes to make the signal stronger, giving a clearer result you can see with the naked eye. The test can detect much smaller amounts of the virus, and is 100 times more sensitive than the gold strip test.

“People have loved the strip test for many years, but it has a major weakness: it’s not sensitive enough. We’re very excited about our new nanozyme test, as it is much more sensitive and you don’t need any specialist equipment to get a quick, accurate result,” said Dr. Yan.

Strip tests work by attaching molecules called antibodies to gold particles to look for a particular molecule in a sample. When they attach to the molecule you’re looking for, in this case a virus, they produce a signal, such as a color change. In order to find the virus, the particles need to be labelled with enzymes, which speed up detection and signalling.

With the new nanozyme test, the researchers applied magnetic nanoparticles as a nanozyme probe in place of gold nanoparticles. After labeling with an antibody that attaches to the Ebola virus, this novel probe is able to recognize and separate the virus in a sample. The nanoparticles are magnetic, so to concentrate the virus particles in a sample, all you need to do is hold the sample against a magnet; no expensive equipment is needed.

The nanozyme test is 100 times more sensitive than the gold strip test, detecting molecules called glycoproteins on the surface of the Ebola virus at concentrations as low as 1 nanogram per milliliter.

The researchers have applied for a patent for the new test, which is currently being taken to west Africa by the CDC to use in the field. The researchers are also collaborating with clinical teams to apply the technology to other diseases, and with a company that treats wastewater to see if it can help remove environmental contamination.

Here’s a link to and a citation for the paper,

Nanozyme-strip for rapid local diagnosis of Ebola by Demin Duan, Kelong Fan, Dexi Zhang, Shuguang Tan, Mifang Liang, Yang Liu, Jianlin Zhang, Panhe Zhang, Wei Liu, Xiangguo Qiu, Gary P. Kobinger, George Fu Gao, Xiyun Yan. Biosensors and Bioelectronics Volume 74, 15 December 2015, Pages 134–141 doi:10.1016/j.bios.2015.05.025

This paper appears to be open access.

Watching motor proteins at work

Leave a reply

Researchers in the UK and in Japan have described these motor proteins as ‘swinging on monkey bars’,

A Sept. 14, 2015 news item on Nanowerk provides more information about the motor protein observations,

These proteins are vital to complex life, forming the transport infrastructure that allows different parts of cells to specialise in particular functions. Until now, the way they move has never been directly observed.

Researchers at the University of Leeds and in Japan used electron microscopes to capture images of the largest type of motor protein, called dynein, during the act of stepping along its molecular track.

A Sept 14, 2015 Leeds University press release, (also on EurekAlert*) which originated the news item, expands on the theme with what amounts to a transcript of sorts for the video (Note: Links have been removed),

Dr Stan Burgess, at the University of Leeds’ School of Molecular and Cellular Biology, who led the research team, said: “Dynein has two identical motors tied together and it moves along a molecular track called a microtubule. It drives itself along the track by alternately grabbing hold of a binding site, executing a power stroke, then letting go, like a person swinging on monkey bars.

“Previously, dynein movement had only been tracked by attaching fluorescent molecules to the proteins and observing the fluorescence using very powerful light microscopes. It was a bit like tracking vehicles from space with GPS. It told us where they were, their speed and for how long they ran, stopped and so on, but we couldn’t see the molecules in action themselves. These are the first images of these vital processes.”

An understanding of motor proteins is important to medical research because of their fundamental role in complex cellular life. Many viruses hijack motor proteins to hitch a ride to the nucleus for replication. Cell division is driven by motor proteins and so insights into their mechanics could be relevant to cancer research. Some motor neurone diseases are also associated with disruption of motor protein traffic.

The team at Leeds, working within the world-leading Astbury Centre for Structural Molecular Biology, combined purified microtubules with purified dynein motors and added the chemical fuel ATP (adenosine triphosphate) to power the motor.

Dr Hiroshi Imai, now Assistant Professor in the Department of Biological Sciences at Chuo University, Japan, carried out the experiments while working at the University of Leeds.

He explained: “We set the dyneins running along their tracks and then we froze them in ‘mid-stride’ by cooling them at about a million degrees a second, fast enough to prevent the water from forming ice crystals as it solidified. Then using a cryo-electron microscope we took many thousands of images of the motors caught during the act of stepping. By combining many images of individual motors, we were able to sharpen up our picture of the dynein and build up a dynamic idea of how it moved. It is a bit like figuring out how to swing along monkey bars by studying photographs of many people swinging on them.”

Dr Burgess said: “Our most striking discovery was the existence of a hinge between the long, thin stalk and the ‘grappling hook’, like the wrist between a human arm and hand. This allows a lot of variation in the angle of attachment of the motor to its track.

“Each of the two arms of a dynein motor protein is about 25 nanometres (0.000025 millimetre) long, while the binding sites it attaches to are only 8 nanometres apart. That means dynein can reach not only the next rung but the one after that and the one after that and appears to give it flexibility in how it moves along the ‘track’.”

Dynein is not only the biggest but also the most versatile of the motor proteins in living cells and, like all motor proteins, is vital to life. Motor proteins transport cargoes and hold many cellular components in position within the cell. For instance, dynein is responsible for carrying messages from the tips of active nerve cells back to the nucleus and these messages keep the nerve cells alive.

Co-author Peter Knight, Professor of Molecular Contractility in the University of Leeds’ School of Molecular and Cellular Biology, said: “If a cell is like a city, these are like the truckers on its road and rail networks. If you didn’t have a transport system, you couldn’t have specialised regions. Every part of the cell would be doing the same thing and that would mean you could not have complex life.”

“Dynein is the multi-purpose vehicle of cellular transport. Other motor proteins, called kinesins and myosins, are much smaller and have specific functions, but dynein can turn its hand to a lot of different of functions,” Professor Knight said.

For instance, in the motor neurone connecting the central nervous system to the big toe—which is a single cell a metre long— dynein provides the transport from the toe back to the nucleus. Another vital role is in the movement of cells.

Dr Burgess said: “During brain development, neurones must crawl into their correct position and dynein molecules in this instance grab hold of the nucleus and pull it along with the moving mass of the cell. If they didn’t, the nucleus would be left behind and the cytoplasm would crawl away.”

The study involved researchers from the University of Leeds and Japan’s Waseda and Osaka universities, as well as the Quantitative Biology Center at Japan’s Riken research institute and the Japan Science and Technology Agency (JST). The research was funded by the Human Frontiers Science Program and the Biotechnology and Biological Sciences Research Council (BBSRC).

Here’s a link to and a citation for the paper,

Direct observation shows superposition and large scale flexibility within cytoplasmic dynein motors moving along microtubules by Hiroshi Imai, Tomohiro Shima, Kazuo Sutoh, Matthew L. Walker, Peter J. Knight, Takahide Kon, & Stan A. Burgess. Nature Communications 6, Article number: 8179  doi:10.1038/ncomms9179 Published 14 September 2015

This paper is open access.

*The EurekAlert link added Sept. 15, 2015 at 1200 hours PST.

Teeny, tiny bugs—microphone-type bugs, that is

Leave a reply

This is more a microscale story than anything else but the image is too good to pass up,

MEMmicrophone

Cirrus Logic MEM microphone Courtesy: ABIresearch

A Sept. 11, 2015 news item on Azonano makes the announcement about the world’s smallest MEM (usually it’s called MEMS for micro-electro-mechanical systems) microphone,

ABI Research’s teardown of a recently released high profile smartphone found that Cirrus Logic introduced the world’s smallest MEM microphone. It is 30% smaller than the smallest MEM microphone and less than half the size of MEM microphones typically found in mobile devices.

Miniature microphones are sometimes referred to as “bugs.” To put this in perspective, Cirrus Logic’s MEM microphone is one-sixth the size of a bed bug.

A Sept. 10, 2015 ABI Research news release, which originated the news item, expands on the theme,

Jim Mielke, VP of Engineering at ABI Research, comments, “Rather than simply shrinking the typical MEM microphone, Cirrus Logic’s WM1706 MEM microphone, which ABI Research named after its die markings, is the first to integrate an amplifier/interface IC and the MEM sensor.”

Along with the record-setting MEM microphone, the phone has a Cirrus Logic audio codec. This codec sits alongside a Qualcomm MSM8939 chipset, a Skyworks power amplifier, Qorvo RF switches and a Broadcom NFC solution.

…

ABI Research provides technology market research and technology intelligence for industry innovators. From offices in North America, Europe and Asia, ABI Research’s worldwide team of experts advises thousands of decision makers through 70+ research and advisory services. ABI Research was established in 1990. …

For anyone interested in Cirrus Logic, here’s their website.

Faster, cheaper, pseudo-organs (also known as organoids)

Leave a reply

There’ve been any number of ‘organoid’ stories recently, here and elsewhere. This one is special due to a quasi extra-cellular matrix (cells have a type of skeletal structure known as an extra-cellular matrix or ECM). From a Sept. 11, 2015 news item on Azonano,

Scientists have developed a new technique that produces a user friendly, low cost, tissue-engineered pseudo-organ. The chip-based model produces a faithful mimic of the in vivo liver inside a scalable fluid-handling device, demonstrating proof of principle for toxicology tests and opening up potential use in drug testing and personalised medicine.

…

The work was done by researchers based at the Wake Forest Institute for Regenerative Medicine and the Virginia Tech-Wake Forest University School of Biomedical Engineering and Sciences. They created a device architecture within which were a series of 3D liver cell constructs enclosed in a biopolymer that closely mimics the extra-cellular matrix (ECM). Surrounding the printed cells with this ECM – which the body uses to support cells in the liver – makes this model a more realistic model of the cells in vivo.

A Sept. 10, 2015 Institute of Physics (IOP) press release, which originated the news item, provides more details about the technology,

The technique uses photopatterning to produce defined 3D constructs in a microfluidic system to probe the construct quickly. “It’s basically scaled-down pluming” explains Adam Hall, an author on the paper. “This paper describes fairly hefty devices – a few mm – but we’re working to scale this down considerably.”

Collaboration proved to be the key to success; “The challenges were not too significant once Adam and I merged our areas of expertise.” adds Aleksander Skardal, another author on the paper. “With his background in devices and microfabrication, and my background in biomaterials and biofabrication, the two technologies integrated rather well.”

The 3D construct device offers a new tool in the development of drug treatments. At present, 2D testing in vitro doesn’t replicate the activity of the cells, and until now 3D systems have not provided adequate interactions of cells with the ECM, or offered particularly high-throughput testing.

This is where the combination of technologies has proven vital. “3D constructs are less effective if you can’t probe them quickly” continues Hall. “And without some important task, microfluidics are just a fun party trick.”

The researchers were also happy how quickly the techniques fell into place.

“The first time we attempted to perform the in situ photopatterning – it just worked” says Skardal. “Science isn’t always that easy, so we knew we might be onto something.”

“Yes – this was one of those rare occasions where things seemed to fall into place” adds Hall.

The researchers are now working to reduce the size of the system allowing for multiple constructs that could be tested individually. This would open potential usage in drug testing and personalised medicine.

“Imagine being able to put, for example, tumor cells from a patient on a chip and test different drug cocktails on them” they conclude. “You could determine the effectiveness and side effects of different treatments on an individual basis without endangering the patient.”

Here’s a link to and a citation for the paper,

In situ patterned micro 3D liver constructs for parallel toxicology testing in a fluidic device by Aleksander Skardal, Mahesh Devarasetty, Shay Soker, and Adam R Hall. Biofabrication, Volume 7, Number 3 DOI: 10.1088/1758-5090/7/3/032001 Published 11 September 2015

© 2015 IOP Publishing Ltd

This is an open access paper.

Science knowledge in the US circa 2014/15

Leave a reply

The Pew Research Center has released a new report on the state of science knowledge in the US general public. From a Sept. 10, 2015 news item on phys.org,

There are substantial differences among Americans when it comes to knowledge and understanding of science topics, especially by educational levels as well as by gender, age, race and ethnicity, according to a new Pew Research Center report.

The representative survey of more than 3,200 U.S. adults finds that, on the 12 multiple-choice questions asked, Americans gave more correct than incorrect answers. The median was eight correct answers out of 12 (mean 7.9). Some 27% answered eight or nine questions correctly, while another 26% answered 10 or 11 items correctly. Just 6% of respondents got a perfect score.

You can test yourself if you like by taking the Pew Research Center’s online Science Knowledge Quiz.

Getting back to the study, a Sept. 10, 2015 Pew Research Center news release on EurekAlert, which originated the news item, provides more detail including general results and demographic breakdowns by education, race and ethnicity, gender, and age.

  • Most Americans (86%) correctly identify the Earth’s inner layer, the core, as its hottest part, and nearly as many (82%) know uranium is needed to make nuclear energy and nuclear weapons.
  • Americans fare well as a whole when it comes to one aspect of science history: Fully 74% of Americans correctly identify Jonas Salk as the person who developed the polio vaccine from among a list of other scientists that included Marie Curie, Albert Einstein and Isaac Newton.
  • And most Americans can distinguish between astronomy and astrology. Seventy-three percent of adults recognize the definition of astrology as the study of how the position of the stars and planets can influence human behavior. By comparison, 22% of adults incorrectly associate this definition with astronomy, while another 5% give some other incorrect response.
  • But other science-related terms and applications are not as well understood. Far fewer are able to identify the property of a sound wave that determines loudness. Just 35% correctly answer amplitude, or height. Some 33% incorrectly say it is frequency and 23% say it is wavelength. And just 34% correctly state that water boils at a lower temperature in a high-altitude setting (Denver) compared with its boiling point near sea level (Los Angeles).

“As science issues become ever-more tied to policy questions, there are important insights that come from exploring how much Americans know about science,” said lead author Cary Funk, an associate director of research at Pew Research Center. “Science encompasses a vast array of fields and information. These data provide a fresh snapshot of what the public knows about some new and some older scientific developments – a mixture of textbook principles covered in K-12 education and topics discussed in the news.”

The data show that adults with higher education levels are more likely to answer questions about science correctly. In this survey, education proves to be a major factor distinguishing higher performers. While the questions asked relate to a small slice of science topics, there are sizeable differences by education on all 12 multiple-choice questions. This pattern is consistent with a 2013 Pew Research Center report on this topic and with analysis of the factual knowledge index in the National Science Board’s Science and Engineering Indicators.

  • Adults with a college or postgraduate degree are more than twice as likely to get at least eight out of 12 questions right, compared with adults with a high school diploma or less (82% vs. 40%). Those with a postgraduate degree score an average of 9.5 correct answers out of 12, while those with a high school education or less get an average of 6.8 correct.
  • Fully 57% of adults with a postgraduate degree get 10 to 12 correct answers, whereas this is true for 18% of those with a high school diploma or less.
  • On all 12 questions, there is at least a 13 percentage point difference in correct answers between the highest- and lowest-educated groups. The largest difference is found in a question about the loudness of a sound. A 62% majority of those with a postgraduate degree correctly identify the amplitude (height) of the sound wave as determining its loudness, as do 52% of those with a four-year college degree. By contrast, 20% of those with a high school education or less answer this question correctly.

In addition to educational differences, gender gaps are evident on these science topics. The survey also finds differences in science knowledge between men and women on these questions, most of which connect to physical sciences. Men, on average, are more likely to give correct answers, even when comparing men and women with similar levels of education.

  • Men score an average of 8.6 out of 12 correct answers, compared with women’s 7.3 correct answers. Some 24% of women answer 10 or more questions correctly, compared with 43% of men who did this.
  • The largest difference between men and women occurs on a question asking respondents to select from a set of four images that illustrate what happens to light when it passes through a magnifying glass. Some 55% of men and 37% of women identify the correct image showing the lines crossing after they pass through a magnifying glass, a difference of 18 percentage points.
  • Men (73%) and women (72%) are equally likely to identify the definition of astrology from a set of four options, however. And on the question about which layer of the Earth is hottest, there are only modest differences, with 89% of men and 84% of women selecting the correct response.
  • Past Pew Research Center studies found women were at least equally likely than men to answer several biomedical questions correctly such as that resistant bacteria is the major concern about overuse of antibiotics. And, women were slightly more likely than men to recognize a more effective way to test a drug treatment in one previous Pew Research Center survey.

The survey also found differences in science knowledge associated with race and ethnicity. Overall, whites know the correct answer to more of these questions than Hispanics or blacks. Whites score a mean of 8.4 items out of 12 correct, compared with 7.1 among Hispanics and 5.9 among blacks. The pattern across these groups and the size of the differences vary, however. These findings are consistent with prior Pew Research Center surveys on this topic. Racial and ethnic group differences are also found on the factual science knowledge index collected on the General Social Survey, even when controlling for education level.

  • One of the largest differences between blacks and whites occurs on a question about the ocean tides: 83% of whites compared with 46% of blacks correctly identify the gravitational pull of the moon as one factor in ocean tides. (Hispanics fall in between these two groups, with 70% answering this question correctly.)
  • On one of the more difficult questions, a roughly equal share of whites (36%) and blacks (33%) correctly identify a difference found in cooking at higher altitudes: that water boils at a lower temperature. A quarter (25%) of Hispanics answered this question correctly.

Generally, younger adults (ages 18 to 49) display slightly higher overall knowledge of science than adults ages 65 and older on the 12 questions in the survey. The oldest adults – ages 65 and up – score lower, on average 7.6 out of 12 items, compared with those under age 50. But adults under age 30 and those ages 30 to 49 tend to identify a similar mean number of items correctly.

  • Fully eight-in-ten (80%) adults ages 18 to 29 correctly identify radio waves as the technology underlying cell phone calls. By contrast, 57% of those ages 65 and older know this.
  • On some questions there are no differences in knowledge across age groups. And, when it comes to one aspect of science history, older adults (ages 65 and older) are more likely than younger adults to identify Jonas Salk as the person who developed the polio vaccine. Fully 86% of those ages 65 and older correctly identify Salk as the vaccine’s developer, compared with 68% of adults ages 18 to 29.

The findings are based on a nationally representative survey of 3,278 randomly-selected adults that participate in Pew Research Center’s American Trends Panel. The survey was conducted Aug. 11-Sept. 3, 2014 and included 12 questions, some of which included images as part of the questions or answer options. …

Cary Funk and Sara Kehaulani Goo wrote the report titled, “A Look at What the Public Knows and Does Not Know About Science.”

Kavli Foundation roundtable on artificial synthesis as a means to produce clean fuel

Leave a reply

A Sept. 9, 2015 news item on Azonano features a recent roundtable discussion about artificial photosynthesis and clean fuel held by the Kavli Foundation,

Imagine creating artificial plants that make gasoline and natural gas using only sunlight. And imagine using those fuels to heat our homes or run our cars without adding any greenhouse gases to the atmosphere. By combining nanoscience and biology, researchers led by scientists at University of California, Berkeley, have taken a big step in that direction.

Peidong Yang, a professor of chemistry at Berkeley and co-director of the school’s Kavli Energy NanoSciences Institute, leads a team that has created an artificial leaf that produces methane, the primary component of natural gas, using a combination of semiconducting nanowires and bacteria. The research, detailed in the online edition of Proceedings of the National Academy of Sciences in August, builds on a similar hybrid system, also recently devised by Yang and his colleagues, that yielded butanol, a component in gasoline, and a variety of biochemical building blocks.

The research is a major advance toward synthetic photosynthesis, a type of solar power based on the ability of plants to transform sunlight, carbon dioxide and water into sugars. Instead of sugars, however, synthetic photosynthesis seeks to produce liquid fuels that can be stored for months or years and distributed through existing energy infrastructure.

In a [Kavli Foundation] roundtable discussion on his recent breakthroughs and the future of synthetic photosynthesis, Yang said his hybrid inorganic/biological systems give researchers new tools to study photosynthesis — and learn its secrets.

There is a list of the participants and an edited transcript of the roundtable, which took place sometime during summer 2015, on the Kavli Foundation’s Fueling up: How nanoscience is creating a new type of solar power webpage (Note: Links have been removed),

The participants were:

PEIDONG YANG – is professor of chemistry and Chan Distinguished Professor of Energy at University of California, Berkeley, and co-director of the Kavli Energy NanoScience Institute at Berkeley National Laboratory and UC Berkeley. He serves as director of the California Research Alliance by BASF, and was a founding member of the U.S. Department of Energy (DOE) Joint Center for Artificial Photosynthesis (JCAP).
THOMAS MOORE – is Regents’ Professor of Chemistry and Biochemistry and past director of the Center for Bioenergy & Photosynthesis at Arizona State University. He is a past president of the American Society for Photobiology, and a team leader at the Center for Bio-Inspired Solar Fuel Production.
TED SARGENT – is a University Professor of Electrical and Computer Engineering at the University of Toronto where he is vice-dean for research for the Faculty of Applied Science and Engineering. He holds the Canada Research Chair in Nanotechnology and is a founder of two companies, InVisage Technologies and Xagenic.

…

THE KAVLI FOUNDATION (TKF): Solar cells do a good job of converting sunlight into electricity. Converting light into fuel seems far more complicated. Why go through the bother?

THOMAS MOORE: That’s a good question. In order to create sustainable, solar-driven societies, we need a way to store solar energy. With solar cells, we can make electricity efficiently, but we cannot conveniently store that electricity to use when it is cloudy or at night. If we want to stockpile large quantities of energy, we have to store it as chemical energy, the way it is locked up in coal, oil, natural gas, hydrogen and biomass.

PEIDONG YANG: I agree. Perhaps, one day, researchers will come up with an effective battery to store photoelectric energy produced by solar cells. But photosynthesis can solve the energy conversion and storage problem in one step. It converts and stores solar energy in the chemical bonds of organic molecules.

TED SARGENT: Much of the globe’s power infrastructure, from automobiles, trucks and planes to gas-fired electrical generators, is built upon carbon-based fossil fuels. So creating a new technology that can generate liquid fuels that can use this infrastructure is a very powerful competitive advantage for a renewable energy technology.

…

For someone who’s interested in solar energy and fuel issues, this discussion provide a good introduction to some of what’s driving the research and, happily, none of these scientists are proselytizing.

One final comment. Ted Sargent has been mentioned here several times in connection with his work on solar cells and/or quantum dots.

US National Institute of Standards and Technology and molecules made of light (lightsabres anyone?)

Leave a reply

As I recall, lightsabres are a Star Wars invention. I gather we’re a long way from running around with lightsabres  but there is hope, if that should be your dream, according to a Sept. 9, 2015 news item on Nanowerk,

… a team including theoretical physicists from JQI [Joint Quantum Institute] and NIST [US National Institute of Stnadards and Technology] has taken another step toward building objects out of photons, and the findings hint that weightless particles of light can be joined into a sort of “molecule” with its own peculiar force.

Here’s an artist’s conception of the light “molecule” provided by the researchers,

Researchers show that two photons, depicted in this artist’s conception as waves (left and right), can be locked together at a short distance. Under certain conditions, the photons can form a state resembling a two-atom molecule, represented as the blue dumbbell shape at center. Credit: E. Edwards/JQI

Researchers show that two photons, depicted in this artist’s conception as waves (left and right), can be locked together at a short distance. Under certain conditions, the photons can form a state resembling a two-atom molecule, represented as the blue dumbbell shape at center. Credit: E. Edwards/JQI

A Sept. 8, 2015 NIST news release (also available on EurekAlert*), which originated the news item, provides more information about the research (Note: Links have been removed),

The findings build on previous research that several team members contributed to before joining NIST. In 2013, collaborators from Harvard, Caltech and MIT found a way to bind two photons together so that one would sit right atop the other, superimposed as they travel. Their experimental demonstration was considered a breakthrough, because no one had ever constructed anything by combining individual photons—inspiring some to imagine that real-life lightsabers were just around the corner.

Now, in a paper forthcoming in Physical Review Letters, the NIST and University of Maryland-based team (with other collaborators) has showed theoretically that by tweaking a few parameters of the binding process, photons could travel side by side, a specific distance from each other. The arrangement is akin to the way that two hydrogen atoms sit next to each other in a hydrogen molecule.

“It’s not a molecule per se, but you can imagine it as having a similar kind of structure,” says NIST’s Alexey Gorshkov. “We’re learning how to build complex states of light that, in turn, can be built into more complex objects. This is the first time anyone has shown how to bind two photons a finite distance apart.”

While the new findings appear to be a step in the right direction—if we can build a molecule of light, why not a sword?—Gorshkov says he is not optimistic that Jedi Knights will be lining up at NIST’s gift shop anytime soon. The main reason is that binding photons requires extreme conditions difficult to produce with a roomful of lab equipment, let alone fit into a sword’s handle. Still, there are plenty of other reasons to make molecular light—humbler than lightsabers, but useful nonetheless.

“Lots of modern technologies are based on light, from communication technology to high-definition imaging,” Gorshkov says. “Many of them would be greatly improved if we could engineer interactions between photons.”

For example, engineers need a way to precisely calibrate light sensors, and Gorshkov says the findings could make it far easier to create a “standard candle” that shines a precise number of photons at a detector. Perhaps more significant to industry, binding and entangling photons could allow computers to use photons as information processors, a job that electronic switches in your computer do today.

Not only would this provide a new basis for creating computer technology, but it also could result in substantial energy savings. Phone messages and other data that currently travel as light beams through fiber optic cables has to be converted into electrons for processing—an inefficient step that wastes a great deal of electricity. If both the transport and the processing of the data could be done with photons directly, it could reduce these energy losses.

Gorshkov says it will be important to test the new theory in practice for these and other potential benefits.

“It’s a cool new way to study photons,” he says. “They’re massless and fly at the speed of light. Slowing them down and binding them may show us other things we didn’t know about them before.”

Here are links and citations for the paper. First, there’s an early version on arXiv.org and, then, there’s the peer-reviewed version, which is not yet available,

Coulomb bound states of strongly interacting photons by M. F. Maghrebi, M. J. Gullans, P. Bienias, S. Choi, I. Martin, O. Firstenberg, M. D. Lukin, H. P. Büchler, A. V. Gorshkov.      arXiv:1505.03859 [quant-ph] (or arXiv:1505.03859v1 [quant-ph] for this version)

Coulomb bound states of strongly interacting photons by M. F. Maghrebi, M. J. Gullans, P. Bienias, S. Choi, I. Martin, O. Firstenberg, M. D. Lukin, H. P. Büchler, and A. V. Gorshkov.
Phys. Rev. Lett. forthcoming in September 2015.

The first version (arXiv) is open access and I’m not sure whether or not the Physical review Letters study will be behind a paywall or be available as an open access paper.

*EurekAlert link added 10:34 am PST on Sept. 11, 2015.

Global overview of nano-enabled food and agriculture regulation

Leave a reply

First off, this post features an open access paper summarizing global regulation of nanotechnology in agriculture and food production. From a Sept. 11, 2015 news item on Nanowerk,

An overview of regulatory solutions worldwide on the use of nanotechnology in food and feed production shows a differing approach: only the EU and Switzerland have nano-specific provisions incorporated in existing legislation, whereas other countries count on non-legally binding guidance and standards for industry. Collaboration among countries across the globe is required to share information and ensure protection for people and the environment, according to the paper …

A Sept. 11, 2015 European Commission Joint Research Centre press release (also on EurekAlert*), which originated the news item, summarizes the paper in more detail (Note: Links have been removed),

The paper “Regulatory aspects of nanotechnology in the agri/feed/food sector in EU and non-EU countries” reviews how potential risks or the safety of nanotechnology are managed in different countries around the world and recognises that this may have implication on the international market of nano-enabled agricultural and food products.

Nanotechnology offers substantial prospects for the development of innovative products and applications in many industrial sectors, including agricultural production, animal feed and treatment, food processing and food contact materials. While some applications are already marketed, many other nano-enabled products are currently under research and development, and may enter the market in the near future. Expected benefits of such products include increased efficacy of agrochemicals through nano-encapsulation, enhanced bioavailability of nutrients or more secure packaging material through microbial nanoparticles.

As with any other regulated product, applicants applying for market approval have to demonstrate the safe use of such new products without posing undue safety risks to the consumer and the environment. Some countries have been more active than others in examining the appropriateness of their regulatory frameworks for dealing with the safety of nanotechnologies. As a consequence, different approaches have been adopted in regulating nano-based products in the agri/feed/food sector.

The analysis shows that the EU along with Switzerland are the only ones which have introduced binding nanomaterial definitions and/or specific provisions for some nanotechnology applications. An example would be the EU labelling requirements for food ingredients in the form of ‘engineered nanomaterials’. Other regions in the world regulate nanomaterials more implicitly mainly by building on non-legally binding guidance and standards for industry.

The overview of existing legislation and guidances published as an open access article in the Journal Regulatory Toxicology and Pharmacology is based on information gathered by the JRC, RIKILT-Wageningen and the European Food Safety Agency (EFSA) through literature research and a dedicated survey.

Here’s a link to and a citation for the paper,

Regulatory aspects of nanotechnology in the agri/feed/food sector in EU and non-EU countries by Valeria Amenta, Karin Aschberger, , Maria Arena, Hans Bouwmeester, Filipa Botelho Moniz, Puck Brandhoff, Stefania Gottardo, Hans J.P. Marvin, Agnieszka Mech, Laia Quiros Pesudo, Hubert Rauscher, Reinhilde Schoonjans, Maria Vittoria Vettori, Stefan Weigel, Ruud J. Peters. Regulatory Toxicology and Pharmacology Volume 73, Issue 1, October 2015, Pages 463–476 doi:10.1016/j.yrtph.2015.06.016

This is the most inclusive overview I’ve seen yet. The authors cover Asian countries, South America, Africa, and the MIddle East, as well as, the usual suspects in Europe and North America.

Given I’m a Canadian blogger I feel obliged to include their summary of the Canadian situation (Note: Links have been removed),

4.2. Canada

The Canadian Food Inspection Agency (CFIA) and Public Health Agency of Canada (PHAC), who have recently joined the Health Portfolio of Health Canada, are responsible for food regulation in Canada. No specific regulation for nanotechnology-based food products is available but such products are regulated under the existing legislative and regulatory frameworks.11 In October 2011 Health Canada published a “Policy Statement on Health Canada’s Working Definition for Nanomaterials” (Health Canada, 2011), the document provides a (working) definition of NM which is focused, similarly to the US definition, on the nanoscale dimensions, or on the nanoscale properties/phenomena of the material (see Annex I). For what concerns general chemicals regulation in Canada, the New Substances (NS) program must ensure that new substances, including substances that are at the nano-scale (i.e. NMs), are assessed in order to determine their toxicological profile ( Environment Canada, 2014). The approach applied involves a pre-manufacture and pre-import notification and assessment process. In 2014, the New Substances program published a guidance aimed at increasing clarity on which NMs are subject to assessment in Canada ( Environment Canada, 2014).

Canadian and US regulatory agencies are working towards harmonising the regulatory approaches for NMs under the US-Canada Regulatory Cooperation Council (RCC) Nanotechnology Initiative.12 Canada and the US recently published a Joint Forward Plan where findings and lessons learnt from the RCC Nanotechnology Initiative are discussed (Canada–United States Regulatory Cooperation Council (RCC) 2014).

Based on their summary of the Canadian situation, with which I am familiar, they’ve done a good job of summarizing. Here are a few of the countries whose regulatory instruments have not been mentioned here before (Note: Links have been removed),

In Turkey a national or regional policy for the responsible development of nanotechnology is under development (OECD, 2013b). Nanotechnology is considered as a strategic technological field and at present 32 nanotechnology research centres are working in this field. Turkey participates as an observer in the EFSA Nano Network (Section 3.6) along with other EU candidate countries Former Yugoslav Republic of Macedonia, and Montenegro (EFSA, 2012). The Inventory and Control of Chemicals Regulation entered into force in Turkey in 2008, which represents a scale-down version of the REACH Regulation (Bergeson et al. 2010). Moreover, the Ministry of Environment and Urban Planning published a Turkish version of CLP Regulation (known as SEA in Turkish) to enter into force as of 1st June 2016 (Intertek).

The Russian legislation on food safety is based on regulatory documents such as the Sanitary Rules and Regulations (“SanPiN”), but also on national standards (known as “GOST”) and technical regulations (Office of Agricultural Affairs of the USDA, 2009). The Russian policy on nanotechnology in the industrial sector has been defined in some national programmes (e.g. Nanotechnology Industry Development Program) and a Russian Corporation of Nanotechnologies was established in 2007.15 As reported by FAO/WHO (FAO/WHO, 2013), 17 documents which deal with the risk assessment of NMs in the food sector were released within such federal programs. Safe reference levels on nanoparticles impact on the human body were developed and implemented in the sanitary regulation for the nanoforms of silver and titanium dioxide and, single wall carbon nanotubes (FAO/WHO, 2013).

Other countries included in this overview are Brazil, India, Japan, China, Malaysia, Iran, Thailand, Taiwan, Australia, New Zealand, US, South Africa, South Korea, Switzerland, and the countries of the European Union.

*EurekAlert link added Sept. 14, 2015.

Natural nanoparticles and perfluorinated compounds in soil

Leave a reply

The claim in a Sept. 9, 2015 news item on Nanowerk is that ‘natural’ nanoparticles are being used to remove perfluorinated compounds (PFC) from soil,

Perfluorinated compounds (PFC) are a new type of pollutants found in contaminated soils from industrial sites, airports and other sites worldwide.

…

In Norway, The Environment Agency has published a plan to eliminate PFOS [perfluorooctanesulfonic acid or perfluorooctane sulfonate] from the environment by 2020. In other countries such as China and the United States, the levels are far higher, and several studies show accumulation of PFOS in fish and animals, however no concrete measures have been taken.

The Norwegian company, Fjordforsk AS, which specializes in nanosciences and environmental methods, has developed a method to remove PFOS from soil by binding them to natural minerals. This method can be used to extract PFOS from contaminated soil and prevent leakage of PFOS to the groundwater.

Electron microscopy images show that the minerals have the ability to bind PFOS on the surface of the natural nanoparticles. [emphasis mine] The proprietary method does not contaminate the treated grounds with chemicals or other parts from remediation process and uses only natural components.

Electron microscopy images and more detail can be found in the Nanowerk news item.

I can’t find the press release, which originated the news item but there is a little additional information about Fjoorkforsk’s remediation efforts on the company’s “Purification of perfluorinated compounds from soil samples” project page,

Project duration: 2014 –

Project leader: Manzetti S.

Collaborators: Prof Lutz Ahrens. Swedish Agricultural University. Prof David van der Spoel, Uppsala University.

Project description:

Perfluorinated compounds (PFCs) are emerging pollutants used in flame retardants on a large scale on airports and other sites of heavy industrial activity. Perfluroinated compounds are toxic and represent an ultra-persistent class of chemicals which can accumulate in animals and humans and have been found to remain in the body for over 5 years after uptake. Perfluorinated compounds can also affect the nerve-system and have recently been associated with high- priority pollutants to be discontinued and to be removed from the environment. Using non-toxic methods, this project develops an approach to sediment perfluorinated compounds from contaminated soil samples using nanoparticles, in order to remove the ecotoxic and ground-water contaminating potential of PFCs from afflicted sites and environments.

The only mineral that I know is used for soil remediation is nano zero-valent iron (nZVI). A very fast search for more information yielded a 2010 EMPA [Swiss Federal Laboratories for Materials Science and Technology] report titled “Nano zero valent iron – THE solution for water and soil remediation? ” (32 pp. pdf) published by ObservatoryNANO.

As for the claim that the company is using ‘natural’ nanoparticles for their remediation efforts, it’s not clear what they mean by that. I suspect they’re using the term ‘natural’ to mean that engineered nanoparticles are being derived from a naturally occurring material, e.g. iron.