Monthly Archives: April 2015

Wound healing is nature’s way of zipping up your skin

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Scientists have been able to observe the healing process at the molecular scale—in fruit flies. From an April 21, 2015 news item on ScienceDaily,

Scientists from the Goethe University (GU) Frankfurt, the European Molecular Biology Laboratory (EMBL) Heidelberg and the University of Zurich explain skin fusion at a molecular level and pinpoint the specific molecules that do the job in their latest publication in the journal Nature Cell Biology.

An April 21, 2015 Goethe University Frankfurt press release on EurekAlert, which originated the news item, describes similarities between humans and fruit flies allowing scientists to infer the wound healing process for human skin,

In order to prevent death by bleeding or infection, every wound (skin opening) must close at some point. The events leading to skin closure had been unclear for many years. Mikhail Eltsov (GU) and colleagues used fruit fly embryos as a model system to understand this process. Similarly to humans, fruit fly embryos at some point in their development have a large opening in the skin on their back that must fuse. This process is called zipping, because two sides of the skin are fastened in a way that resembles a zipper that joins two sides of a jacket.

The scientists have used a top-of-the-range electron microscope to study exactly how this zipping of the skin works. “Our electron microscope allows us to distinguish the molecular components in the cell that act like small machines to fuse the skin. When we look at it from a distance, it appears as if skin cells simply fuse to each other, but if we zoom in, it becomes clear that membranes, molecular machines, and other cellular components are involved”, explains Eltsov.

“In order to visualize this orchestra of healing, a very high-resolution picture of the process is needed. For this purpose we have recorded an enormous amount of data that surpasses all previous studies of this kind”, says Mikhail Eltsov.

As a first step, as the scientists discovered, cells find their opposing partner by “sniffing” each other out. As a next step, they develop adherens junctions which act like a molecular Velcro. This way they become strongly attached to their opposing partner cell. The biggest revelation of this study was that small tubes in the cell, called microtubules, attach to this molecular Velcro and then deploy a self-catastrophe, which results in the skin being pulled towards the opening, as if one pulls a blanket over.

Damian Brunner who led the team at the University of Zurich has performed many genetic manipulations to identify the correct components. The scientists were astonished to find that microtubules involved in cell-division are the primary scaffold used for zipping, indicating a mechanism conserved during evolution.

“What was also amazing was the tremendous plasticity of the membranes in this process which managed to close the skin opening in a very short space of time. When five to ten cells have found their respective neighbors, the skin already appears normal”, says Achilleas Frangakis from the Goethe University Frankfurt, who led the study.

The scientists hope that their results will open new avenues into the understanding of epithelial plasticity and wound healing. They are also investigating the detailed structural organization of the adherens junctions, work for which they were awarded a starting grant from European Research Council (ERC).

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

Quantitative analysis of cytoskeletal reorganization during epithelial tissue sealing by large-volume electron tomography by Mikhail Eltsov, Nadia Dubé, Zhou Yu, Laurynas Pasakarnis, Uta Haselmann-Weiss, Damian Brunner, & Achilleas S. Frangakis. Nature Cell Biology (2015) doi:10.1038/ncb3159 Published online 20 April 2015

This paper is behind a paywall but there is a free preview available via ReadCube Access.

The researchers have provided an image illustrating ‘wound zipping’.

Caption: This is a perspective view of the zipping area with 17 skin cells. Credit: GU

Caption: This is a perspective view of the zipping area with 17 skin cells.
Credit: GU

Café Scientifique (Vancouver, Canada) makes a ‘happy’ change: new speaker for April 28, 2015

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For the first time since I’ve started posting about Vancouver’s Café Scientifique there’s been a last minute change of speakers. It’s due to an addition to Dr. Kramer’s family. Congratulations!

So, Tuesday, April 28, 2015’s  Café Scientifique, held in the back room of The Railway Club (2nd floor of 579 Dunsmuir St. [at Seymour St.], will be hosting a talk from a different speaker and on a different topic,

Ph.D candidate and Vanier Scholar, Kostadin Kushlev from the Department of Psychology at UBC presenting his exciting research. Details are as follows:

Always Connected: How Smartphones May be Disconnecting Us From the People Around Us.

Smartphones have transformed where and how we access information and connect with our family and friends. But how might these powerful pocket computers be affecting how and when we interact with others in person? In this talk, I will present recent data from our lab suggesting that smartphones can compromise how connected we feel to close others, peers, and strangers. Parents spending time with their children felt more distracted and less socially connected when they used their phones a lot. Peers waiting together for an appointment connected with each other less and felt less happy when they had access to their phones as compared to when they did not. And, people looking for directions trusted members of their community less when they relied on their phones for directions rather than on the kindness of strangers. These findings highlight some of the perils of being constantly connected for our nonvirtual social lives and for the social fabric of society more generally.

On looking up the speaker online, I found that the main focus of his research is happiness, from the University of British Columbia’s (UBC) Graduate and PostGraduate webpage for Kostadin Kushlev,

 Research topic: Happiness and well-being
Research group: Social Cognition and Emotion Lab
Research location: UBC Vancouver, Kenny Building, 2136 West Mall
Research supervisor: Elizabeth Dunn

Research description
My research focuses on the emotional experience of people. The topics that I am currently investigating range from what gives (or takes away from) people’s experience of meaning in life to how people react to shame and guilt, and to what extent new technologies introduce stress and anxiety in our lives.

Home town: Madan
Country: Bulgaria

Given that the United Nations’ 2015 World Happiness Report (co-authored by UBC professor emeritus John Helliwell) was released on April 23, 2015,  the same day that the Museum of Vancouver’s The Happy Show (Stefan Sagmeister: The Happy Show) opened, Kostadin Kushlev seems like a ‘happy’ choice for a substitute speaker just days later on April 28, 2015, especially since the original topic was ‘pain’.

Steep (1) at International Symposium on Electronic Arts (ISEA) 2015 in Vancouver, Canada

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Our paper (Raewyn Turner, an artist from New Zealand,  and mine, Maryse de la Giroday), Steep (I): a digital poetry of gold nanoparticles, has been accepted for the 2015 International Symposium on Electronic Arts (ISEA) to be held in Vancouver, Canada from Aug. 14 – 18, 2015. I last wrote about ISEA 2015 in a Dec. 19, 2014 post where I indicated more information about our project would be forthcoming—the next week. Ah well, better late than never, eh?

Before getting to our project, here’s a little information on the symposium’s theme (from the Theme page),

ISEA2015’s theme of DISRUPTION invites a conversation about the aesthetics of change, renewal, and game-changing paradigms. We look to raw bursts of energy, reconciliation, error, and the destructive and creative forces of the new. Disruption contains both blue sky and black smoke. When we speak of radical emergence we must also address things left behind. Disruption is both incremental and monumental.

In practices ranging from hacking and detournement to inversions of place, time, and intention, creative work across disciplines constantly finds ways to rethink or reconsider form, function, context, body, network, and culture. Artists push, shape, break; designers reinvent and overturn; scientists challenge, disprove and re-state; technologists hack and subvert to rebuild.

Disruption and rupture are fundamental to digital aesthetics. Instantiations of the digital realm continue to proliferate in contemporary culture, allowing us to observe ever-broader consequences of these effects and the aesthetic, functional, social and political possibilities that arise from them.

Within this theme, we want to investigate trends in digital and internet aesthetics and revive exchange across disciplines. We hope to broaden the spheres in which disruptive aesthetics can be explored, crossing into the worlds of science, technology, design, visual art, contemporary and media art, innovation, performance, and sound.

At least two of the speakers are going to be very well aligned with the disruption theme (from the Keynote Speakers page),

TheYesMen Yes Men

Session Title: Tactical and Creative Resistance

The Yes Men, Andy Bichlbaum and Mike Bonanno, have been called “the Jonathan Swift of the Jackass generation” by author Naomi Klein. The Yes Men have impersonated World Trade Organization, Dow Chemical Corporation, and Bush administration spokesmen on TV and at business conferences around the world. They do this (a) in order to demonstrate some of the mechanisms that keep bad people and ideas in power, and (b) because it’s absurdly fun. As the Yes Men, they use humor, truth and lunacy to bring media attention to the crimes of their unwilling employers. Their second film, The Yes Men Fix the World, won the audience award at this year’s Berlin Film Festival, the Grierson Award for Most Entertaining Documentary, and went on to become a smash box-office sensation, only just barely surpassed by Avatar. Their main goal is to focus attention on the dangers of economic policies that place the rights of capital before the needs of people and the environment.

connorMichael Connor

Sessions Title: TBD

Michael Connor is the Editor and Curator of Rhizome at the New Museum. Connor’s work focuses on artists’ responses to cinema and new technologies. His past solo and collaborative projects as curator include: ‘Liquid Crystal Palace,’ Honor Fraser, Los Angeles; ‘Street Digital’ (works by artist duo JODI); ‘Wild Sky,’ Edith-Russ Haus, Oldenburg, Germany; ‘Screen Worlds’, ACMI in Melbourne; ‘Essential Cinema’ at the Toronto Film Festival, and ‘The New Normal’ touring exhibition. Connor previously worked as Curator at FACT, Liverpool and Head of Exhibitions at BFI Southbank, London.

Brian Massumi

Session Title: No One Without Another: Creativity and Decision in the Transindividual Fold

Brian Massumi is professor of communication at the University of Montreal. He specializes in the philosophy of experience, art and media theory, and political philosophy. His most recent books include Politics of Affect (Polity, 2015), The Power at the End of the Economy (Duke UP, 2015), and What Animals Teach Us about Politics (Duke UP, 2014). He is co-author with Erin Manning of Thought in the Act: Passages in the Ecology of Experience (co-written with Erin Manning; University of Minnesota Press, 2014). Also with Erin Manning and the SenseLab collective, he participates in the collective exploration of new ways of bringing philosophical and artistic practices into collaborative interaction, most recently in the frame of the “Immediations: Art, Media, Event” international partnership project.

DMoulon

Dominique Moulon

Sessions Title: TBD

Dominique Moulon studied visual art at the Fine Art School (ENSA) of Bourges and holds a Master’s Degree in aesthetics, science and technology from the University of Paris 8. Member of the Observatory of Digital Worlds in Humanities (OMNSH), of the International Association of Art Critics (AICA), of the Opline Prize for online contemporary art and founder of MediaArtDesign.net ; he also writes articles for Art Press, Digital MCD, The Seen and Neural. He is the Artistic Director of the media art fair Variation Paris and currently curator in residence at the art center of the Maison Populaire in Montreuil. Dominique Moulon teaches new media at Parsons (The New School for Design), ECV (Ecole de Communication Visuelle) and EPSAA (Ecole Professionnelle Supérieure d’Arts Graphiques) in Paris. He has also been a regular guest professor at the School of the Art Institute of Chicago (SAIC), the National School of Fine Arts (ENSBA) in Paris, The Fresnoy (Studio national des arts contemporains) and the University of Paris 8. His book Contemporary New Media Art was published in French by Nouvelles Editions Scala in 2011 and in English as an e-book in 2013. He is doing research at the laboratory Art & Flux (CNRS) of the University of Paris 1 Panthéon-Sorbonne while preparing his next book on the relationships between art, technology and society. As an expert in digital cultures, he has also been sollicited for his input by some companies like Axa, Accenture, Google, Landor or Renault.

Hildegard Westerkamp

Westerkamp_2012

Sessions Title: TBD

Hildegard Westerkamp has lectured on topics of listening, environmental sound and acoustic ecology and has conducted soundscape workshops internationally. By focusing the ears’ attention to details in the acoustic environment, her compositional work draws attention to the act of listening itself and to the inner, hidden spaces of the environment we inhabit. For details check her website: http://www.sfu.ca/~westerka

Her music has been commissioned by CBC Radio, Canada Pavilion at Expo ’86, Ars Electronica (Linz), Österreichischer Rundfunk, Zentrum für Kunst und Medien in Germany…. She received Honorable Mentions in competitions such as Prix Ars Electronica in Austria, Prix Italia, and the International Competition for Electroacoustic Music in Bourges, as well as a Recommendation for Broadcast from the International Music Council’s 4th International Rostrum of Electroacoustic Music. Her articles have been published in Radio Rethink, Kunstforum, Musicworks, MusikTexte and a variety of books… For an extensive exploration into her compositional work see Andra McCartney’s Sounding Places: Situated Conversations through the Soundscape Work of Hildegard Westerkamp, York University, Toronto, 1999, and in the internet at: http://beatrouteproductions.com/Andradiss.pdf

As part of Vancouver New Music’s yearly season she has coordinated and led  Soundwalks for some years since 2003, which in turn inspired the creation of The Vancouver Soundwalk Collective.

A founding member of the World Forum for Acoustic Ecology (WFAE, see: www.wfae.net), and long-time co-editor of its journal Soundscape, Westerkamp was a researcher for R. Murray Schafer’s World Soundscape Project in the Seventies, and has taught acoustic communication at Simon Fraser University with colleague Barry Truax.

Sara Diamond

Biography coming soon

As for the last speaker on the list, Sara Diamond is the president of the Ontario College of Art and Design University (OCAD University). Her professional focus is digital media and prior to heading OCAD University she was the Artistic Director of Media and Visual Art and Director of Research at the Banff Centre. You can find out more about Sara Diamond here.

Back to Steep, this is a project concerning gold nanoparticles. Here’s what Raewyn wrote about it on the homepage of the Steep website,

The general atmosphere is saturated and awash with particles and vibrations that are transpired by living beings and everything on earth. Emerging  into the troposphere, sounds and fragrances arise from cultural, social and political systems that have engineered the landscapes and thus mindscapes into settlements, habitations, fields, factories, front lawns and streets.

In the absence of a visceral sensing of the atmospheric ocean of particles and cues which are in dynamic flux with perception., Steep combines art+ science+ technology to explore sensing gold nanotechnology, where it accumulates, changes over time, and how it may affect living beings and the environment

Raewyn, a visual artist (video, painting, sculpture, interactive installations) and concept and design theatre artist and lighting designer located in Auckland, New Zealand, contacted me, located in Vancouver, Canada, a few years ago after reading some of the material I have on gold nanoparticles. She wanted to make contact with a scientist who was examining gold nanoparticles as they circulate from products into the air, the water, and the soil. Eventually I remembered the Duke University mesocosm project, located in Durham, North Carolina, at the Center for the Environmental Implication of Nano Technology (CEINT) led by Mark Wiesner (first mentioned here in an Aug. 15, 2011 post) and so Raewyn found her scientist and, although she wasn’t looking for one, a writer too. Her longtime collaborator, Brian Harris (located in Auckland, New Zealand), has an electronics background and is an independent designer and inventor who “invents and creates large scale finely tuned adaptive mechatronics and bespoke equipment. His inventions for motion control, stabilising camera mounts for aerial photography and robotic trajectories have been used in local and international tv, commercial and film productions.” (from the Steep About Us page).

For our first Steep project, Raewyn and I are working on a digital poetry installation. Here’s more about the project from the paper,

Steep is an international art/science research project examining the impact gold and gold nanoparticles have had in the past and could have in the future. Designed as a multi-year, multidisciplinary project with a rotating cast of collaborators, Steep is based on the current state of scientific research and its flexibility as a project reflects the uncertain and disruptive state of nanoscience and nanotechnology (as they are sometimes referred to).

    Steep (I) a digital poetry of gold nanoparticles, our first piece, is largely concerned with the elements of air and earth or more fancifully, gold in all its forms: myth, metaphor, and reality as it transitions visibly and invisibly throughout our environment.

The following poetry excerpt and video sample accompanying this submission [the video sample is not included in this posting] are works in progress and a research project within themselves.

Yearning
(excerpt)

shards of sun
hidden in the river’s silted bed
buried beneath the earth’s skin

a beautiful killing
in the cold, cold river
in the darkness underground

opportunities made of gold
wealth beyond Croesus’ and Midas’ imaginings
shining brighter than the sun

The other two parts of the trilogy are titled: Light/Shadow and Discovery respectively. I may have to change that last three lines to:

opportunities of gold
beyond Midas’ and Croesus’ imaginings
brighter than the sun

Raewyn and I are quite excited but there’s still work to do (our reviewers had comments).

Partners wanted to commercialize new production technique for metallic nanoparticles

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An April 20, 2015 news item on Azonano announces a new technique for producing metallic nanoparticles (Note: A link has been removed),

Researchers at VTT Technical Research Centre of Finland Ltd have devised a new, inexpensive metallic nanoparticle manufacturing technique.

The aerosol technology reactor employed for nanoparticle synthesis is capable of producing carbon-coated particles, particles of various alloys and a number of pure metal particles. It can even produce several grams and kilograms of nanoparticles every day.

Nanoparticles are suitable for applications including energy technology, tailoring the electrical and magnetic properties of polymers, drug dosing and medical diagnostics, and conductive and magnetic inks. VTT is looking forward to commercialize the technique.

An April 20, 2015 VTT press release (also on EurekAlert), which originated the news item,  describes the project’s achievements in more detail and makes a plea (of sorts) for partners to commercialize this work,

“Demand has outstripped supply in the nanoparticle markets. This has been an obstacle to the development of product applications; nano-metal composites are scarce and often available in small quantities only. We wanted to demonstrate that it was possible to produce nanomaterials in considerable quantities cost-effectively,” comments Ari Auvinen of VTT, head of the research team.

When developing the reactor, the aim was to achieve a production figure of 200-3,000 grammes per day. This has already been clearly exceeded. Due to the extremely small material wastage incurred when using this equipment, remote-control production can be maintained for several days. In most cases, industrial production of metallic nanoparticles involves chemical reduction in liquid solutions, which requires the design of product-specific solutions. Plasma synthesis, which consumes large amounts of energy and involves significant material wastage, is another generally used method.

In the design of the reactor developed by VTT, the scalability and cost-effectiveness of the synthesis process were key criteria. For this reason, synthesis is performed under air pressure at a comparatively low temperature. This means that the equipment can be built from materials commonly used in industry and energy consumption is low. The process generates an extremely high particle concentration, enabling a high production speed but with low gas consumption. In addition, even impure metallic salts can be used as a raw material, which keeps the price low.

VTT has demonstrated the practical functionality of its reactor by testing the production of various nanometals, metallic compounds and carbon-coated materials. Materials such as carbon-coated magnets, which can be used as catalysts in biorefineries – say, in the production of biofuels – have been produced in the reactor. Following synthesis, magnets used as catalysts can be efficiently gathered in and recycled back into the process.

Nanoparticles have also been tested in the manufacture of magnetic inks and inks that conduct electricity in printed electronics. For example, VTT succeeded in using a permalloy ink to print a magnetically anisotropic material, which can be used in the manufacture of magnetic field sensors.

VTT’s third application trial involved the prevention of microwave reflection. The tests showed that reflection can be reduced by even 10,000 times in polymers, by adding particles which increase radar wave attenuation.

VTT’s researchers believe that the reactor has many applications in addition to those already mentioned. The silicon nanoparticles it produces may even enable lithium battery capacity to be boosted by a factor of 10. Other possible applications, all of which require further investigation, include high permeability polymers, nanomagnets for medical diagnostics applications, materials for the 3D printing of metal articles, and silicon-based materials for thermoelectric and solar power components.

VTT is currently seeking a party interested in commercialising the technique.

For interested parties, here is the contact information listed in the press release,

For more information, please contact:

Raimo Korhonen, Head of Research Area
tel. +358 40 7030052, raimo.korhonen@vtt.fi

Good luck!

Maple syrup as an antibiotic helper?

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This maple syrup research is from McGill University in Montréal, Québec (from an April 16, 2015 McGill University news release; also on EurekAlert),

A concentrated extract of maple syrup makes disease-causing bacteria more susceptible to antibiotics, according to laboratory experiments by researchers at McGill University.

The findings, which will be published in the journal Applied and Environmental Microbiology, suggest that combining maple syrup extract with common antibiotics could increase the microbes’ susceptibility, leading to lower antibiotic usage. Overuse of antibiotics fuels the emergence of drug-resistant bacteria, which has become a major public-health concern worldwide.

Prof. Nathalie Tufenkji’s research team in McGill’s Department of Chemical Engineering prepared a concentrated extract of maple syrup that consists mainly of phenolic compounds. Maple syrup, made by concentrating the sap from North American maple trees, is a rich source of phenolic compounds.

The researchers tested the extract’s effect in the laboratory on infection-causing strains of certain bacteria, including E. coli and Proteus mirabilis (a common cause of urinary tract infection). By itself, the extract was mildly effective in combating bacteria. But the maple syrup extract was particularly effective when applied in combination with antibiotics. The extract also acted synergistically with antibiotics in destroying resistant communities of bacteria known as biofilms, which are common in difficult-to-treat infections, such as catheter-associated urinary tract infections.

“We would have to do in vivo tests, and eventually clinical trials, before we can say what the effect would be in humans,” Tufenkji says. “But the findings suggest a potentially simple and effective approach for reducing antibiotic usage. I could see maple syrup extract being incorporated eventually, for example, into the capsules of antibiotics.”

The scientists also found that the extract affects the gene expression of the bacteria, by repressing a number of genes linked with antibiotic resistance and virulence.

All maple syrup samples used in the study were purchased at local markets in Montreal, then frozen until the beginning of each experiment, which involved a series of steps to produce the phenolic-rich extract.

Tufenkji, who holds the Canada Research Chair in Biocolloids and Surfaces, has also studied the potential for cranberry derivatives to fight infection-causing bacteria. The new study is co-authored by postdoctoral fellows Vimal Maisuria and Zeinab Hosseinidoust.

Here’s a link to and a citation for the paper which at this time (April 24, 2014) is not yet published,,

Polyphenolic Extract from Maple Syrup Potentiates Antibiotic Susceptibility and Reduces Biofilm Formation of Pathogenic Bacteria by Vimal B. Maisuria, Zeinab Hosseinidoust, and Nathalie Tufenkji. doi: 10.1128/AEM.00239-15 AEM [Applied and Environmental Microbiology].00239-15

My guess is that this paper will be behind a paywall. Fear not! There is a very informative 3 mins. or so video,

I particularly appreciated the maple leaf-shaped glass container (still full) which is shown prominently when the researcher mentions purchasing the syrup from local markets.

What colour is your diagnosis?

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Mark Lorch has written an April 16, 2015 piece for The Conversation (h/t the Guardian’s April 17, 2015 posting) about a very appealing approach to diagnostics (Note: A link has been removed),

If you’ve ever sat opposite a doctor and wondered what she was scribbling on her notepad, the answer may soon not only be medical notes on your condition, but real-time chemical preparations for an instant diagnostic test.

Thanks to the work of a team of researchers from California Polytechnic State University, recently published in the journal Lab on a Chip, chemicals formed into pencils can be made to react with one another by simply drawing with them on paper. The team may have taken inspiration from colouring books for their take on a chemical toolkit, but their approach could make carrying out simple but common diagnostic tests based on chemical reactions – for example diabetes, HIV, or tests for environmental pollutants – much easier.

Here’s a picture of the pens,

ReagentPencilsDiagnostics

Courtesy: Lab on a Chip

Lorch provides a good description of the technology giving descriptions of reagents and paper-based microfluidics, as well as, describing how the researchers turned the concept of colouring pencils into a diagnostic tool.

Lorch also provides a description of a specific test (Note: Links have been removed),

The team demonstrated a potential use of the reagent pencil technique by using it in place of a common test used by diabetics to check their blood glucose levels, which involves reacting a pinprick blood sample with a chemical solution and examining the result.

One pencil was constructed with a mixture of enzymes, one called horseradish peroxidase (HRP) and the other glucose oxidase (GOx). A second pencil contained a reagent called ABTS. When combined in the presence of glucose these react together to give a blue-coloured product. Comparing the results from their pencils on the pad with the more traditional dropper method used by diabetics the team found the results were identical.

This new ‘pencil kit’ diagnostic technology is easy to use and features a big improvement over the current diagnostic tests,

This is of course extremely easy to set up. Traditional diagnostic tests require training, while this pad and pencil system requires no more than skill than required to colour within the lines. The reagents are extremely stable once made into pencils – usually they would degrade in a matter of days as liquids, limiting how and where the tests can be made. However the reagent pencils showed no sign of degrading after two months.

Being able to use the pencils for two months as opposed to liquids that remain viable for a few days? That’s a huge jump and it makes me wonder about using these kits in harsh conditions such as desert climates and/or emergency situations. Materials that don’t need to be refrigerated and could be used for up to two months and don’t require intensive training could be very helpful. Lorch suggests some other possibilities as well,

… There’s scope to monitor environmental pollutants, carry out diagnostic tests in remote locations – not to mention teach chemistry in primary schools.

Here’s a link to and a citation for the study on the ‘colouring pencil kit’,

Reagent pencils: a new technique for solvent-free deposition of reagents onto paper-based microfluidic devices by Haydn T. Mitchell, Isabelle C. Noxon, Cory A. Chaplan, Samantha J. Carlton, Cheyenne H. Liu, Kirsten A. Ganaja, Nathaniel W. Martinez, Chad E. Immoos, Philip J. Costanzo, and Andres W. Martinez. Lab Chip, 2015, Advance Article DOI: 10.1039/C5LC00297D First published online 08 Apr 2015

This paper is open access but you do have to register on the site unless you have another means of access.

Water’s liquid-vapour interface

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The UK’s National Physical Laboratory (NPL), along with IBM and the University of Edinburgh, has developed a new quantum model for understanding water’s liquid-vapour interface according to an April 20, 2015 news item on Nanowerk,

The National Physical Laboratory (NPL), the UK’s National Measurement Institute in collaboration with IBM and the University of Edinburgh, has used a new quantum model to reveal the molecular structure of water’s liquid surface.

The liquid-vapour interface of water is one of the most common of all heterogeneous (or non-uniform) environments. Understanding its molecular structure will provide insight into complex biochemical interactions underpinning many biological processes. But experimental measurements of the molecular structure of water’s surface are challenging, and currently competing models predict various different arrangements.

An April 20, 2015 NPL press release on EurekAlert, which originated the news item, describes the model and research in more detail,

The model is based on a single charged particle, the quantum Drude oscillator (QDO), which mimics the way the electrons of a real water molecule fluctuate and respond to their environment. This simplified representation retains interactions not normally accessible in classical models and accurately captures the properties of liquid water.

In new research, published in a featured article in the journal Physical Chemistry Chemical Physics, the team used the QDO model to determine the molecular structure of water’s liquid surface. The results provide new insight into the hydrogen-bonding topology at the interface, which is responsible for the unusually high surface tension of water.

This is the first time the QDO model of water has been applied to the liquid-vapour interface. The results enabled the researchers to identify the intrinsic asymmetry of hydrogen bonds as the mechanism responsible for the surface’s molecular orientation. The model was also capable of predicting the temperature dependence of the surface tension with remarkable accuracy – to within 1 % of experimental values.

Coupled with earlier work on bulk water, this result demonstrates the exceptional transferability of the QDO approach and offers a promising new platform for molecular exploration of condensed matter.

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

Hydrogen bonding and molecular orientation at the liquid–vapour interface of water by Flaviu S. Cipcigan, Vlad P. Sokhan, Andrew P. Jones, Jason Crain and Glenn J. Martyna.  Phys. Chem. Chem. Phys., 2015,17, 8660-8669 DOI: 10.1039/C4CP05506C First published online 17 Feb 2015

The paper is open access although you do need to register on the site provided you don’t have some other means of accessing the paper.

Carbon nanotubes sense spoiled food

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CNT_FoodSpolage

Courtesy: MIT (Massachusetts Institute of Technology)

I love this .gif; it says a lot without a word. However for details, you need words and here’s what an April 15, 2015 news item on Nanowerk has to say about the research illustrated by the .gif,

MIT [Massachusetts Institute of Technology] chemists have devised an inexpensive, portable sensor that can detect gases emitted by rotting meat, allowing consumers to determine whether the meat in their grocery store or refrigerator is safe to eat.

The sensor, which consists of chemically modified carbon nanotubes, could be deployed in “smart packaging” that would offer much more accurate safety information than the expiration date on the package, says Timothy Swager, the John D. MacArthur Professor of Chemistry at MIT.

An April 14, 2015 MIT news release (also on EurekAlert), which originated the news item, offers more from Dr. Swager,

It could also cut down on food waste, he adds. “People are constantly throwing things out that probably aren’t bad,” says Swager, who is the senior author of a paper describing the new sensor this week in the journal Angewandte Chemie.

This latest study is builds on previous work at Swager’s lab (Note: Links have been removed),

The sensor is similar to other carbon nanotube devices that Swager’s lab has developed in recent years, including one that detects the ripeness of fruit. All of these devices work on the same principle: Carbon nanotubes can be chemically modified so that their ability to carry an electric current changes in the presence of a particular gas.

In this case, the researchers modified the carbon nanotubes with metal-containing compounds called metalloporphyrins, which contain a central metal atom bound to several nitrogen-containing rings. Hemoglobin, which carries oxygen in the blood, is a metalloporphyrin with iron as the central atom.

For this sensor, the researchers used a metalloporphyrin with cobalt at its center. Metalloporphyrins are very good at binding to nitrogen-containing compounds called amines. Of particular interest to the researchers were the so-called biogenic amines, such as putrescine and cadaverine, which are produced by decaying meat.

When the cobalt-containing porphyrin binds to any of these amines, it increases the electrical resistance of the carbon nanotube, which can be easily measured.

“We use these porphyrins to fabricate a very simple device where we apply a potential across the device and then monitor the current. When the device encounters amines, which are markers of decaying meat, the current of the device will become lower,” Liu says.

In this study, the researchers tested the sensor on four types of meat: pork, chicken, cod, and salmon. They found that when refrigerated, all four types stayed fresh over four days. Left unrefrigerated, the samples all decayed, but at varying rates.

There are other sensors that can detect the signs of decaying meat, but they are usually large and expensive instruments that require expertise to operate. “The advantage we have is these are the cheapest, smallest, easiest-to-manufacture sensors,” Swager says.

“There are several potential advantages in having an inexpensive sensor for measuring, in real time, the freshness of meat and fish products, including preventing foodborne illness, increasing overall customer satisfaction, and reducing food waste at grocery stores and in consumers’ homes,” says Roberto Forloni, a senior science fellow at Sealed Air, a major supplier of food packaging, who was not part of the research team.

The new device also requires very little power and could be incorporated into a wireless platform Swager’s lab recently developed that allows a regular smartphone to read output from carbon nanotube sensors such as this one.

The funding sources are interesting, as I am appreciating with increasing frequency these days (from the news release),

The researchers have filed for a patent on the technology and hope to license it for commercial development. The research was funded by the National Science Foundation and the Army Research Office through MIT’s Institute for Soldier Nanotechnologies.

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

Single-Walled Carbon Nanotube/Metalloporphyrin Composites for the Chemiresistive Detection of Amines and Meat Spoilage by Sophie F. Liu, Alexander R. Petty, Dr. Graham T. Sazama, and Timothy M. Swager. Angewandte Chemie International Edition DOI: 10.1002/anie.201501434 Article first published online: 13 APR 2015

© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This article is behind a paywall.

There are other posts here about the quest to create food sensors including this Sept. 26, 2013 piece which features a critique (by another blogger) about trying to create food sensors that may be more expensive than the item they are protecting, a problem Swager claims to have overcome in an April 17, 2015 article by Ben Schiller for Fast Company (Note: Links have been removed),

Swager has set up a company to commercialize the technology and he expects to do the first demonstrations to interested clients this summer. The first applications are likely to be for food workers working with meat and fish, but there’s no reason why consumers shouldn’t get their own devices in due time.

There are efforts to create visual clues for food status. But Swager says his method is better because it doesn’t rely on perception: it produces hard data that can be logged and tracked. And it also has potential to be very cheap.

“The resistance method is a game-changer because it’s two to three orders of magnitude cheaper than other technology. It’s hard to imagine doing this cheaper,” he says.

Glasswing butterflies teach us about reflection

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Contrary to other transparent surfaces, the wings of the glasswing butterfly (Greta Oto) hardly reflect any light. Lenses or displays of mobiles might profit from the investigation of this phenomenon. (Photo: Radwanul Hasan Siddique, KIT)

Contrary to other transparent surfaces, the wings of the glasswing butterfly (Greta Oto) hardly reflect any light. Lenses or displays of mobiles might profit from the investigation of this phenomenon. (Photo: Radwanul Hasan Siddique, KIT)

I wouldn’t have really believed. Other than glass, I’ve never seen anything in nature that’s as transparent and distortion-free as this butterfly’s wings.

An April 22, 2015 news item on ScienceDaily provides more information about the butterfly,

The effect is known from the smart phone: Sun is reflected by the display and hardly anything can be seen. In contrast to this, the glasswing butterfly hardly reflects any light in spite of its transparent wings. As a result, it is difficult for predatory birds to track the butterfly during the flight. Researchers of KIT under the direction of Hendrik Hölscher found that irregular nanostructures on the surface of the butterfly wing cause the low reflection. In theoretical experiments, they succeeded in reproducing the effect that opens up fascinating application options, e.g. for displays of mobile phones or laptops.

An April 22, 2015 Karlsruhe Institute of Technology (KIT) press release (also on EurekAlert), which originated the news item, explains the scientific interest,

Transparent materials such as glass, always reflect part of the incident light. Some animals with transparent surfaces, such as the moth with its eyes, succeed in keeping the reflections small, but only when the view angle is vertical to the surface. The wings of the glasswing butterfly that lives mainly in Central America, however, also have a very low reflection when looking onto them under higher angles. Depending on the view angle, specular reflection varies between two and five percent. For comparison: As a function of the view angle, a flat glass plane reflects between eight and 100 percent, i.e. reflection exceeds that of the butterfly wing by several factors. Interestingly, the butterfly wing does not only exhibit a low reflection of the light spectrum visible to humans, but also suppresses the infrared and ultraviolet radiation that can be perceived by animals. This is important to the survival of the butterfly.

For research into this so far unstudied phenomenon, the scientists examined glasswings by scanning electron microscopy. Earlier studies revealed that regular pillar-like nanostructures are responsible for the low reflections of other animals. The scientists now also found nanopillars on the butterfly wings. In contrast to previous findings, however, they are arranged irregularly and feature a random height. Typical height of the pillars varies between 400 and 600 nanometers, the distance of the pillars ranges between 100 and 140 nanometers. This corresponds to about one thousandth of a human hair.

In simulations, the researchers mathematically modeled this irregularity of the nanopillars in height and arrangement. They found that the calculated reflected amount of light exactly corresponds to the observed amount at variable view angles. In this way, they proved that the low reflection at variable view angles is caused by this irregularity of the nanopillars. Hölscher’s doctoral student Radwanul Hasan Siddique, who discovered this effect, considers the glasswing butterfly a fascinating animal: “Not only optically with its transparent wings, but also scientifically. In contrast to other natural phenomena, where regularity is of top priority, the glasswing butterfly uses an apparent chaos to reach effects that are also fascinating for us humans.”

The findings open up a range of applications wherever low-reflection surfaces are needed, for lenses or displays of mobile phones, for instance. Apart from theoretical studies of the phenomenon, the infrastructure of the Institute of Microstructure Technology also allows for practical implementation. First application tests are in the conception phase at the moment. Prototype experiments, however, already revealed that this type of surface coating also has a water-repellent and self-cleaning effect.

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

The role of random nanostructures for the omnidirectional anti-reflection properties of the glasswing butterfly by Radwanul Hasan Siddique, Guillaume Gomard, & Hendrik Hölscher. Nature Communications 6, Article number: 6909 doi:10.1038/ncomms7909 Published 22 April 2015

The paper is behind a paywall but there is a free preview via ReadCube Access.

Reversing Parkinson’s type symptoms in rats

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Indian scientists have developed a technique for delivering drugs that could reverse Parkinson-like symptoms according to an April 22, 2015 news item on Nanowerk (Note: A link has been removed),

As baby boomers age, the number of people diagnosed with Parkinson’s disease is expected to increase. Patients who develop this disease usually start experiencing symptoms around age 60 or older. Currently, there’s no cure, but scientists are reporting a novel approach that reversed Parkinson’s-like symptoms in rats.

Their results, published in the journal ACS Nano (“Trans-Blood Brain Barrier Delivery of Dopamine-Loaded Nanoparticles Reverses Functional Deficits in Parkinsonian Rats”), could one day lead to a new therapy for human patients.

An April 22, 2015 American Chemical Society press pac news release (also on EurekAlert), which originated the news item, describes the problem the researchers were solving (Note: Links have been removed),

Rajnish Kumar Chaturvedi, Kavita Seth, Kailash Chand Gupta and colleagues from the CSIR-Indian Institute of Toxicology Research note that among other issues, people with Parkinson’s lack dopamine in the brain. Dopamine is a chemical messenger that helps nerve cells communicate with each other and is involved in normal body movements. Reduced levels cause the shaking and mobility problems associated with Parkinson’s. Symptoms can be relieved in animal models of the disease by infusing the compound into their brains. But researchers haven’t yet figured out how to safely deliver dopamine directly to the human brain, which is protected by something called the blood-brain barrier that keeps out pathogens, as well as many medicines. Chaturvedi and Gupta’s team wanted to find a way to overcome this challenge.

The researchers packaged dopamine in biodegradable nanoparticles that have been used to deliver other therapeutic drugs to the brain. The resulting nanoparticles successfully crossed the blood-brain barrier in rats, released its dopamine payload over several days and reversed the rodents’ movement problems without causing side effects.

The authors acknowledge funding from the Indian Department of Science and Technology as Woman Scientist and Ramanna Fellow Grant, and the Council of Scientific and Industrial Research (India).

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

Trans-Blood Brain Barrier Delivery of Dopamine-Loaded Nanoparticles Reverses Functional Deficits in Parkinsonian Rats by Richa Pahuja, Kavita Seth, Anshi Shukla, Rajendra Kumar Shukla, Priyanka Bhatnagar, Lalit Kumar Singh Chauhan, Prem Narain Saxena, Jharna Arun, Bhushan Pradosh Chaudhari, Devendra Kumar Patel, Sheelendra Pratap Singh, Rakesh Shukla, Vinay Kumar Khanna, Pradeep Kumar, Rajnish Kumar Chaturvedi, and Kailash Chand Gupta. ACS Nano, Article ASAP DOI: 10.1021/nn506408v Publication Date (Web): March 31, 2015
Copyright © 2015 American Chemical Society

This paper is open access.

Another recent example of breaching the blood-brain barrier, coincidentally, in rats, can be found in my Dec. 24, 2014 titled: Gelatin nanoparticles for drug delivery after a stroke. Scientists are also trying to figure out the the blood-brain barrier operates in the first place as per this April 22, 2015 University of Pennsylvania news release on EurekAlert titled, Penn Vet, Montreal and McGill researchers show how blood-brain barrier is maintained (University of Pennsylvania School of Veterinary Medicine, University of Montreal or Université de Montréal, and McGill University). You can find out more about CSIR-Indian Institute of Toxicology Research here.