Tag Archives: University of Tokyo

Replace plastic with Choetsu which waterproofs paper and degrades safely

It’s good to see research into practical ways of replacing plastic. From a May 13, 2022 news item on ScienceDaily,

For our sake and the environment, there is a considerable amount of research into the reduction of plastic for many and various applications. For the first time, researchers have found a way to imbue relatively sustainable paper materials with some of the useful properties of plastic. This can be done easily, cost effectively, and efficiently. A coating called Choetsu not only waterproofs paper, but also maintains its flexibility and degrades safely as well.

Caption: A classic origami crane made from paper and coated with Choetsu (left) and uncoated (right). When submerged in water, the coated paper crane keeps its shape while the uncoated one quickly saturates with water and starts to disintegrate. Credit: ©2022 Hiroi et al.

A May 13, 2022 University of Tokyo press release (also on EurekAlert), which originated the news item, describes the work in more detail,

It’s hard to escape the fact that plastic materials are by and large detrimental to the environment. You’ve probably seen images of plastic pollution washing up on beaches, spoiling rivers and killing countless animals. Yet the problem often seems completely out of our hands given the ubiquity of plastic materials in everyday life. Professor Zenji Hiroi from the Institute for Solid State Physics at the University of Tokyo and his team explore ways materials science can help, and their recent discovery aims to replace some uses of plastic with something more sustainable: Paper.

“The main problem with plastic materials as I see it is their inability to degrade quickly and safely,” said Hiroi. “There are materials that can degrade safely, such as paper, but obviously paper cannot fulfill the vast range of uses plastic can. However, we’ve found a way to give paper some of the nice properties of plastic, but with none of the detriments. We call it Choetsu, a low-cost biodegradable coating that adds waterproofing and strength to simple paper.”

Choetsu is a combination of materials which, when applied to paper, spontaneously generate a strong and waterproof film when it makes contact with moisture in the air. The coating consists of safe and low-cost chemicals, mostly methyltrimethoxysilane, some isopropyl alcohol, and a small amount of tetraisopropyl titanate. Paper structures, for example food containers, are sprayed with or dipped into this liquid mixture and are dried at room temperature. Once dry, a thin layer of silica containing methyl, a type of alcohol, forms on the cellulose making up the paper, providing the strong and waterproof properties.

Furthermore, reactions that take place during the coating procedure automatically creates a layer of titanium dioxide nanoparticles. These give rise to a dirt- and bacterial-repellent property known as photocatalytic activity, which protects the coated item for an extended period of time. All of the chemicals involved in the coating break down over time into harmless things such as carbon, water and sandlike silicon.

“The technical challenge is complete, and some applications could be realized soon, such as items for consuming, packaging or storing food,” said Hiroi. “We now hope to use this approach on other kinds of materials as well. The liquid composition can be tuned for other materials, and we can create a dirt- and mold-resistant coating that could form onto glass, ceramics and even other plastics to extend their usefulness. Alongside researcher Yoko Iwamiya, who has been working in this field for some time now, and the rest of my team, I hope we can do something truly beneficial for the world.”

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

Photocatalytic Silica–Resin Coating for Environmental Protection of Paper as a Plastic Substitute by Yoko Iwamiya, Daisuke Nishio-Hamane, Kazuhiro Akutsu-Suyama, Hiroshi Arima-Osonoi, Mitsuhiro Shibayama, and Zenji Hiroi. Ind. Eng. Chem. Res. 2022, XXXX, XXX, XXX-XXX DOI: https://doi.org/10.1021/acs.iecr.2c00784 Publication Date: May 13, 2022 © 2022 American Chemical Society

This paper is behind a paywall.

Fluorine-based nanostructures for desalination

A May 16, 2022 article by Qamariya Nasrullah for cosmosmagazine.com describes research from Japan on desalination (Note: A link has been removed),

Water supply is a growing global issue, especially with climate change bringing on more droughts. Seawater desalination is used worldwide to filter up to 97.4 million cubic metres per day. Two methods – thermal and reverse osmosis – predominate; both have huge energy costs.

In a pioneering study published in Science, researchers have used a fluorine-based nanostructure to successfully filter salt from water faster and more efficiently than other current technologies. But how does it work?

A May 12, 2022 University of Tokyo press release (also on EurekAlert), which originated the news item, provides the answer to Nasrullah’s question,

If you’ve ever cooked with a nonstick Teflon-coated frying pan, then you’ve probably seen the way that wet ingredients slide around it easily. This happens because the key component of Teflon is fluorine, a lightweight element that is naturally water repelling, or hydrophobic. Teflon can also be used to line pipes to improve the flow of water. Such behavior caught the attention of Associate Professor Yoshimitsu Itoh from the Department of Chemistry and Biotechnology at the University of Tokyo and his team. It inspired them to explore how pipes or channels made from fluorine might operate on a very different scale, the nanoscale.

“We were curious to see how effective a fluorous nanochannel might be at selectively filtering different compounds, in particular, water and salt. And, after running some complex computer simulations, we decided it was worth the time and effort to create a working sample,” said Itoh. “There are two main ways to desalinate water currently: thermally, using heat to evaporate seawater so it condenses as pure water, or by reverse osmosis, which uses pressure to force water through a membrane that blocks salt. Both methods require a lot of energy, but our tests suggest fluorous nanochannels require little energy, and have other benefits too.”

The team created test filtration membranes by chemically synthesizing nanoscopic fluorine rings, which were stacked and embedded in an otherwise impermeable lipid layer, similar to the organic molecules that make up cell walls. They created several test samples with nanorings between about 1 and 2 nanometers. For reference, a human hair is almost 100,000 nanometers wide. To test the effectiveness of their membranes, Itoh and the team measured the presence of chlorine ions, one of the major components of salt — the other being sodium — on either side of the test membrane.

“It was very exciting to see the results firsthand. The smaller of our test channels perfectly rejected incoming salt molecules, and the larger channels too were still an improvement over other desalination techniques and even cutting-edge carbon nanotube filters,” said Itoh. “The real surprise to me was how fast the process occurred. Our sample worked around several thousand times faster than typical industrial devices, and around 2,400 times faster than experimental carbon nanotube-based desalination devices.”

As fluorine is electrically negative, it repels negative ions such as the chlorine found in salt. But an added bonus of this negativity is that it also breaks down what are known as water clusters, essentially loosely bound groups of water molecules, so that they pass through the channels quicker. The team’s fluorine-based water desalination membranes are more effective, faster, require less energy to operate and are made to be very simple to use as well, so what’s the catch?

“At present, the way we synthesize our materials is relatively energy-intensive itself; however, this is something we hope to improve upon in upcoming research. And, given the longevity of the membranes and their low operational costs, the overall energy costs will be much lower than with current methods,” said Itoh. “Other steps we wish to take are of course scaling this up. Our test samples were single nanochannels, but with the help of other specialists, we hope to create a membrane around 1 meter across in several years. In parallel with these manufacturing concerns, we’re also exploring whether similar membranes could be used to reduce carbon dioxide or other undesirable waste products released by industry.”

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

Ultrafast water permeation through nanochannels with a densely fluorous interior surface by Yoshimitsu Itoh, Shuo Chen, Jyota Hirahara, Takeshi Konda, Tsubasa Aoki, Takumi Ueda, Ichio Shimada, James J. Cannon, Cheng Shao, Junichiro Shiomi, Kazuhito V. Tabata, Hiroyuki Noji, Kohei Sato, and Takuzo Aida. Science • 12 May 2022 • Vol 376, Issue 6594 • pp. 738-743 • DOI: 10.1126/science.abd0966

This paper is behind a paywall.

Philosophy and science in Tokyo, Japan from Dec. 1-2, 2022

I have not seen a more timely and à propos overview for a meeting/conference/congress that this one for Tokyo Forum 2022 (hosted by the University of Tokyo and South Korea’s Chey Institute for Advanced Studies),

Dialogue between Philosophy and Science: In a World Facing War, Pandemic, and Climate Change

In the face of war, a pandemic, and climate change, we cannot repeat the history of the last century, in which our ancestors headed down the road to division, global conflict, and environmental destruction.

How can we live more fully and how do we find a new common understanding about what our society should be? Tokyo Forum 2022 will tackle these questions through a series of in-depth dialogues between philosophy and science. The dialogues will weave together the latest findings and deep contemplation, and explore paths that could lead us to viable answers and solutions.

Philosophy of the 21st century must contribute to the construction of a new universality based on locality and diversity. It should be a universality that is open to co-existing with other non-human elements, such as ecosystems and nature, while severely criticizing the understanding of history that unreflectively identifies anthropocentrism with universality.

Science in the 21st century also needs to dispense with its overarching aura of supremacy and lack of self-criticism. There is a need for scientists to make efforts to demarcate their own limits. This also means reexamining what ethics means for science.

Tokyo Forum 2022 will offer multifaceted dialogues between philosophers, scientists, and scholars from various fields of study on the state and humanity in the 21st century, with a view to imagining and proposing a vision of the society we need.

Here are some details about the hybrid event from a November 4, 2022 University of Tokyo press release on EurekAlert,

The University of Tokyo and South Korea’s Chey Institute for Advanced Studies will host Tokyo Forum 2022 from Dec. 1-2, 2022. Under this year’s theme “Dialogue between Philosophy and Science,” the annual symposium will bring together philosophers, scientists and scholars in various fields from around the world for multifaceted dialogues on humanity and the state in the 21st century, while envisioning the society we need.

The event is free and open to the public, and will be held both on site at Yasuda Auditorium of the University of Tokyo and online via livestream. [emphases mine]

Keynote speakers lined up for the first day of the two-day symposium are former U.N. Secretary-General Ban Ki-moon, University of Chicago President Paul Alivisatos and Mariko Hasegawa, president of the Graduate University for Advanced Studies in Japan.

Other featured speakers on the event’s opening day include renowned modern thinker and author Professor Markus Gabriel of the University of Bonn, and physicist Hirosi Ooguri, director of the Kavli Institute for the Physics and Mathematics of the Universe at the University of Tokyo and professor at the California Institute of Technology, who are scheduled to participate in the high-level discussion on the dialogue between philosophy and science.

Columbia University Professor Jeffrey Sachs will take part in a panel discussion, also on Day 1, on tackling global environmental issues with stewardship of the global commons — the stable and resilient Earth system that sustains our lives — as a global common value.

The four panel discussions slated for Day 2 will cover the role of world philosophy in addressing the problems of a globalized world; transformative change for a sustainable future by understanding the diverse values of nature and its contributions to people; the current and future impacts of autonomous robots on society; and finding collective solutions and universal values to pursue equitable and sustainable futures for humanity by looking at interconnections among various fields of inquiry.

Opening remarks will be delivered by University of Tokyo President Teruo Fujii and South Korea’s SK Group Chairman Chey Tae-won, on Day 1. Fujii and Chey Institute President Park In-kook will make closing remarks following the wrap-up session on the second and final day.

Tokyo Forum with its overarching theme “Shaping the Future” is held annually since 2019 to stimulate discussions on finding the best ideas for shaping the world and humanity in the face of complex situations where the conventional wisdom can no longer provide answers.

For more information about the program and speakers of Tokyo Forum 2022, visit the event website and social media accounts:

Website: https://www.tokyoforum.tc.u-tokyo.ac.jp/en/index.html

Twitter: https://twitter.com/UTokyo_forum

Facebook: https://www.facebook.com/UTokyo.tokyo.forum/

To register, fill out the registration form on the Tokyo Forum 2022 website (registration is free but required [emphasis mine] to attend the event): https://www.tokyo-forum-form.com/apply/audiences/en

I’m not sure how they are handling languages. I’m guessing that people are speaking in the language they choose and translations (subtitles or dubbing) are available. For anyone who may have difficulty attending due to timezone issues, there are archives for previous Tokyo Forums. Presumably 2022 will be added at some point in the future.

Growing electronics on trees

An April 26, 2022 news item on phys.org caught my eye with its mention of nanocellulose, trees, and electronics,

Electronics can grow on trees thanks to nanocellulose paper semiconductors

Semiconducting nanomaterials with 3D network structures have high surface areas and a lot of pores that make them excellent for applications involving adsorbing, separating, and sensing. However, simultaneously controlling the electrical properties and creating useful micro- and macro-scale structures, while achieving excellent functionality and end-use versatility, remains challenging. Now, Osaka University researchers, in collaboration with The University of Tokyo, Kyushu University, and Okayama University, have developed a nanocellulose paper semiconductor that provides both nano−micro−macro trans-scale designability of the 3D structures and wide tunability of the electrical properties. Their findings are published in ACS Nano.

Cellulose is a natural and easy to source material derived from wood. Cellulose nanofibers (nanocellulose) can be made into sheets of flexible nanocellulose paper (nanopaper) with dimensions like those of standard A4. Nanopaper does not conduct an electric current; however, heating can introduce conducting properties. Unfortunately, this exposure to heat can also disrupt the nanostructure.

The researchers have therefore devised a treatment process that allows them to heat the nanopaper without damaging the structures of the paper from the nanoscale up to the macroscale.

Caption: Schematic diagram of the preparation of the wood nanocellulose-derived nano-semiconductor with customizable electrical properties and 3D structures Credit: 2022 Koga et al. Nanocellulose paper semiconductor with a 3D network structure and its nano−micro−macro trans-scale design. ACS Nano

An April 28, 2022 Osaka University news release (also on EurekAlert), which originated the news item, provides more detail about the work

“An important property for the nanopaper semiconductor is tunability because this allows devices to be designed for specific applications,” explains study author Hirotaka Koga. “We applied an iodine treatment that was very effective for protecting the nanostructure of the nanopaper. Combining this with spatially controlled drying meant that the pyrolysis treatment did not substantially alter the designed structures and the selected temperature could be used to control the electrical properties.”

The researchers used origami (paper folding) and kirigami (paper cutting) techniques to provide playful examples of the flexibility of the nanopaper at the macrolevel. A bird and box were folded, shapes including an apple and snowflake were punched out, and more intricate structures were produced by laser cutting. This demonstrated the level of detail possible, as well as the lack of damage caused by the heat treatment.

Examples of successful applications showed nanopaper semiconductor sensors incorporated into wearable devices to detect exhaled moisture breaking through facemasks and moisture on the skin. The nanopaper semiconductor was also used as an electrode in a glucose biofuel cell and the energy generated lit a small bulb.

“The structure maintenance and tunability that we have been able to show is very encouraging for the translation of nanomaterials into practical devices,” says Associate Professor Koga. “We believe that our approach will underpin the next steps in sustainable electronics made entirely from plant materials.”

About Osaka University

Osaka University was founded in 1931 as one of the seven imperial universities of Japan and is now one of Japan’s leading comprehensive universities with a broad disciplinary spectrum. This strength is coupled with a singular drive for innovation that extends throughout the scientific process, from fundamental research to the creation of applied technology with positive economic impacts. Its commitment to innovation has been recognized in Japan and around the world, being named Japan’s most innovative university in 2015 (Reuters 2015 Top 100) and one of the most innovative institutions in the world in 2017 (Innovative Universities and the Nature Index Innovation 2017). Now, Osaka University is leveraging its role as a Designated National University Corporation selected by the Ministry of Education, Culture, Sports, Science and Technology to contribute to innovation for human welfare, sustainable development of society, and social transformation.

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

Nanocellulose Paper Semiconductor with a 3D Network Structure and Its Nano–Micro–Macro Trans-Scale Design by Hirotaka Koga, Kazuki Nagashima, Koichi Suematsu, Tsunaki Takahashi, Luting Zhu, Daiki Fukushima, Yintong Huang, Ryo Nakagawa, Jiangyang Liu, Kojiro Uetani, Masaya Nogi, Takeshi Yanagida, and Yuta Nishina. ACS Nano 2022, XXXX, XXX, XXX-XXX DOI: https://doi.org/10.1021/acsnano.1c10728 Publication Date:April 26, 2022 © 2022 The Authors. Published by American Chemical Society

The paper appears to be open access.

Put a ring on it: preventing clumps of gold nanoparticles

Caption: A comparison of how linear PEG (left) and cyclic PEG (right) attach to a gold nanoparticle Credit: Yubo Wang, Takuya Yamamoto

A January 20, 2021 news item on phys.org focuses on work designed to stop gold nanoparticles from clumping together (Note: A link has been removed),

Hokkaido University scientists have found a way to prevent gold nanoparticles from clumping, which could help towards their use as an anti-cancer therapy.

Attaching ring-shaped synthetic compounds to gold nanoparticles helps them retain their essential light-absorbing properties, Hokkaido University researchers report in the journal Nature Communications.

A January 20, 2021 Hokkaido University press release (also on EurekAlert but published Jan. 21, 2020), which originated the news item, elaborates on the work,

Metal nanoparticles have unique light-absorbing properties, making them interesting for a wide range of optical, electronic and biomedical applications. For example, if delivered to a tumour, they could react with applied light to kill cancerous tissue. A problem with this approach, though, is that they easily clump together in solution, losing their ability to absorb light. This clumping happens in response to a variety of factors, including temperature, salt concentration and acidity.

Scientists have been trying to find ways to ensure nanoparticles stay dispersed in their target environments. Covering them with polyethylene glycol, otherwise known as PEG, has been relatively successful at this in the case of gold nanoparticles. PEG is biocompatible and can prevent gold surfaces from clumping together in the laboratory and in living organisms, but improvements are still needed.

Applied chemist Takuya Yamamoto and colleagues at Hokkaido University, The University of Tokyo, and Tokyo Institute of Technology found that mixing gold nanoparticles with ring-shaped PEG, rather than the normally linear PEG, significantly improved dispersion. The ‘cyclic-PEG’ (c-PEG) attaches to the surfaces of the nanoparticles without forming chemical bonds with them, a process called physisorption. The coated nanoparticles remained dispersed when frozen, freeze-dried and heated.

The team tested the c-PEG-covered gold nanoparticles in mice and found that they cleared slowly from the blood and accumulated better in tumours compared to gold nanoparticles coated with linear PEG. However, accumulation was lower than desired levels, so the researchers recommend further investigations to fine-tune the nanoparticles for this purpose.

Associate Professor Takuya Yamamoto is part of the Laboratory of Chemistry of Molecular Assemblies at Hokkaido University, where he studies the properties and applications of various cyclic chemical compounds.

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

Enhanced dispersion stability of gold nanoparticles by the physisorption of cyclic poly(ethylene glycol) by Yubo Wang, Jose Enrico Q. Quinsaat, Tomoko Ono, Masatoshi Maeki, Manabu Tokeshi, Takuya Isono, Kenji Tajima, Toshifumi Satoh, Shin-ichiro Sato, Yutaka Miura & Takuya Yamamoto. Nature Communications volume 11, Article number: 6089 (2020) DOI: https://doi.org/10.1038/s41467-020-19947-8 Published: 30 November 2020

This paper is open access.

A quantum phenomenon (Kondo effect) and nanomaterials

This is a little outside my comfort zone but here goes anyway. From a December 23, 2020 news item on phys.org (Note: Links have been removed),

Osaka City University scientists have developed mathematical formulas to describe the current and fluctuations of strongly correlated electrons in quantum dots. Their theoretical predictions could soon be tested experimentally.

Theoretical physicists Yoshimichi Teratani and Akira Oguri of Osaka City University, and Rui Sakano of the University of Tokyo have developed mathematical formulas that describe a physical phenomenon happening within quantum dots and other nanosized materials. The formulas, published in the journal Physical Review Letters, could be applied to further theoretical research about the physics of quantum dots, ultra-cold atomic gasses, and quarks.

At issue is the Kondo effect. This effect was first described in 1964 by Japanese theoretical physicist Jun Kondo in some magnetic materials, but now appears to happen in many other systems, including quantum dots and other nanoscale materials.

A December 23, 2020 Osaka City University press release (also on EurekAlert), which originated the news item, provides more detail,

Normally, electrical resistance drops in metals as the temperature drops. But in metals containing magnetic impurities, this only happens down to a critical temperature, beyond which resistance rises with dropping temperatures.

Scientists were eventually able to show that, at very low temperatures near absolute zero, electron spins become entangled with the magnetic impurities, forming a cloud that screens their magnetism. The cloud’s shape changes with further temperature drops, leading to a rise in resistance. This same effect happens when other external ‘perturbations’, such as a voltage or magnetic field, are applied to the metal. 

Teratani, Sakano and Oguri wanted to develop mathematical formulas to describe the evolution of this cloud in quantum dots and other nanoscale materials, which is not an easy task. 

To describe such a complex quantum system, they started with a system at absolute zero where a well-established theoretical model, namely Fermi liquid theory, for interacting electrons is applicable. They then added a ‘correction’ that describes another aspect of the system against external perturbations. Using this technique, they wrote formulas describing electrical current and its fluctuation through quantum dots. 

Their formulas indicate electrons interact within these systems in two different ways that contribute to the Kondo effect. First, two electrons collide with each other, forming well-defined quasiparticles that propagate within the Kondo cloud. More significantly, an interaction called a three-body contribution occurs. This is when two electrons combine in the presence of a third electron, causing an energy shift of quasiparticles. 

“The formulas’ predictions could soon be investigated experimentally”, Oguri says. “Studies along the lines of this research have only just begun,” he adds. 

The formulas could also be extended to understand other quantum phenomena, such as quantum particle movement through quantum dots connected to superconductors. Quantum dots could be a key for realizing quantum information technologies, such as quantum computers and quantum communication.

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

Fermi Liquid Theory for Nonlinear Transport through a Multilevel Anderson Impurity by Yoshimichi Teratani, Rui Sakano, and Akira Oguri. Phys. Rev. Lett. 125, 216801 (Issue Vol. 125, Iss. 21 — 20 November 2020) DOI: https://doi.org/10.1103/PhysRevLett.125.216801 Published Online: 17 November 2020

This paper is behind a paywall.

Quantum processor woven from light

Weaving a quantum processor from light is a jaw-dropping event (as far as I’m concerned). An October 17, 2019 news item on phys.org makes the announcement,

An international team of scientists from Australia, Japan and the United States has produced a prototype of a large-scale quantum processor made of laser light.

Based on a design ten years in the making, the processor has built-in scalability that allows the number of quantum components—made out of light—to scale to extreme numbers. The research was published in Science today [October 18, 2019; Note: I cannot explain the discrepancy between the dates]].

Quantum computers promise fast solutions to hard problems, but to do this they require a large number of quantum components and must be relatively error free. Current quantum processors are still small and prone to errors. This new design provides an alternative solution, using light, to reach the scale required to eventually outperform classical computers on important problems.

Caption: The entanglement structure of a large-scale quantum processor made of light. Credit: Shota Yokoyama 2019

An October 18, 2019 RMIT University (Australia) press release (also on EurekAlert but published October 17, 2019), which originated the news time, expands on the theme,

“While today’s quantum processors are impressive, it isn’t clear if the current designs can be scaled up to extremely large sizes,” notes Dr Nicolas Menicucci, Chief Investigator at the Centre for Quantum Computation and Communication Technology (CQC2T) at RMIT University in Melbourne, Australia.

“Our approach starts with extreme scalability – built in from the very beginning – because the processor, called a cluster state, is made out of light.”

Using light as a quantum processor

A cluster state is a large collection of entangled quantum components that performs quantum computations when measured in a particular way.

“To be useful for real-world problems, a cluster state must be both large enough and have the right entanglement structure. In the two decades since they were proposed, all previous demonstrations of cluster states have failed on one or both of these counts,” says Dr Menicucci. “Ours is the first ever to succeed at both.”

To make the cluster state, specially designed crystals convert ordinary laser light into a type of quantum light called squeezed light, which is then weaved into a cluster state by a network of mirrors, beamsplitters and optical fibres.

The team’s design allows for a relatively small experiment to generate an immense two-dimensional cluster state with scalability built in. Although the levels of squeezing – a measure of quality – are currently too low for solving practical problems, the design is compatible with approaches to achieve state-of-the-art squeezing levels.

The team says their achievement opens up new possibilities for quantum computing with light.

“In this work, for the first time in any system, we have made a large-scale cluster state whose structure enables universal quantum computation.” Says Dr Hidehiro Yonezawa, Chief Investigator, CQC2T at UNSW Canberra. “Our experiment demonstrates that this design is feasible – and scalable.”

###

The experiment was an international effort, with the design developed through collaboration by Dr Menicucci at RMIT, Dr Rafael Alexander from the University of New Mexico and UNSW Canberra researchers Dr Hidehiro Yonezawa and Dr Shota Yokoyama. A team of experimentalists at the University of Tokyo, led by Professor Akira Furusawa, performed the ground-breaking experiment.

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

Generation of time-domain-multiplexed two-dimensional cluster state by Warit Asavanant, Yu Shiozawa, Shota Yokoyama, Baramee Charoensombutamon, Hiroki Emura, Rafael N. Alexander, Shuntaro Takeda, Jun-ichi Yoshikawa, Nicolas C. Menicucci, Hidehiro Yonezawa, Akira Furusawa. Science 18 Oct 2019: Vol. 366, Issue 6463, pp. 373-376 DOI: 10.1126/science.aay2645

This paper is behind a paywall.

AI (artificial intelligence) for Good Global Summit from May 15 – 17, 2018 in Geneva, Switzerland: details and an interview with Frederic Werner

With all the talk about artificial intelligence (AI), a lot more attention seems to be paid to apocalyptic scenarios: loss of jobs, financial hardship, loss of personal agency and privacy, and more with all of these impacts being described as global. Still, there are some folks who are considering and working on ‘AI for good’.

If you’d asked me, the International Telecommunications Union (ITU) would not have been my first guess (my choice would have been United Nations Educational, Scientific and Cultural Organization [UNESCO]) as an agency likely to host the 2018 AI for Good Global Summit. But, it turns out the ITU is a UN (United Nations agency) and, according to its Wikipedia entry, it’s an intergovernmental public-private partnership, which may explain the nature of the participants in the upcoming summit.

The news

First, there’s a May 4, 2018 ITU media advisory (received via email or you can find the full media advisory here) about the upcoming summit,

Artificial Intelligence (AI) is now widely identified as being able to address the greatest challenges facing humanity – supporting innovation in fields ranging from crisis management and healthcare to smart cities and communications networking.

The second annual ‘AI for Good Global Summit’ will take place 15-17 May [2018] in Geneva, and seeks to leverage AI to accelerate progress towards the United Nations’ Sustainable Development Goals and ultimately benefit humanity.

WHAT: Global event to advance ‘AI for Good’ with the participation of internationally recognized AI experts. The programme will include interactive high-level panels, while ‘AI Breakthrough Teams’ will propose AI strategies able to create impact in the near term, guided by an expert audience of mentors representing government, industry, academia and civil society – through interactive sessions. The summit will connect AI innovators with public and private-sector decision-makers, building collaboration to take promising strategies forward.

A special demo & exhibit track will feature innovative applications of AI designed to: protect women from sexual violence, avoid infant crib deaths, end child abuse, predict oral cancer, and improve mental health treatments for depression – as well as interactive robots including: Alice, a Dutch invention designed to support the aged; iCub, an open-source robot; and Sophia, the humanoid AI robot.

WHEN: 15-17 May 2018, beginning daily at 9 AM

WHERE: ITU Headquarters, 2 Rue de Varembé, Geneva, Switzerland (Please note: entrance to ITU is now limited for all visitors to the Montbrillant building entrance only on rue Varembé).

WHO: Confirmed participants to date include expert representatives from: Association for Computing Machinery, Bill and Melinda Gates Foundation, Cambridge University, Carnegie Mellon, Chan Zuckerberg Initiative, Consumer Trade Association, Facebook, Fraunhofer, Google, Harvard University, IBM Watson, IEEE, Intellectual Ventures, ITU, Microsoft, Massachusetts Institute of Technology (MIT), Partnership on AI, Planet Labs, Shenzhen Open Innovation Lab, University of California at Berkeley, University of Tokyo, XPRIZE Foundation, Yale University – and the participation of “Sophia” the humanoid robot and “iCub” the EU open source robotcub.

The interview

Frederic Werner, Senior Communications Officer at the International Telecommunication Union and** one of the organizers of the AI for Good Global Summit 2018 kindly took the time to speak to me and provide a few more details about the upcoming event.

Werner noted that the 2018 event grew out of a much smaller 2017 ‘workshop’ and first of its kind, about beneficial AI which this year has ballooned in size to 91 countries (about 15 participants are expected from Canada), 32 UN agencies, and substantive representation from the private sector. The 2017 event featured Dr. Yoshua Bengio of the University of Montreal  (Université de Montréal) was a featured speaker.

“This year, we’re focused on action-oriented projects that will help us reach our Sustainable Development Goals (SDGs) by 2030. We’re looking at near-term practical AI applications,” says Werner. “We’re matchmaking problem-owners and solution-owners.”

Academics, industry professionals, government officials, and representatives from UN agencies are gathering  to work on four tracks/themes:

In advance of this meeting, the group launched an AI repository (an action item from the 2017 meeting) on April 25, 2018 inviting people to list their AI projects (from the ITU’s April 25, 2018? AI repository news announcement),

ITU has just launched an AI Repository where anyone working in the field of artificial intelligence (AI) can contribute key information about how to leverage AI to help solve humanity’s greatest challenges.

This is the only global repository that identifies AI-related projects, research initiatives, think-tanks and organizations that aim to accelerate progress on the 17 United Nations’ Sustainable Development Goals (SDGs).

To submit a project, just press ‘Submit’ on the AI Repository site and fill in the online questionnaire, providing all relevant details of your project. You will also be asked to map your project to the relevant World Summit on the Information Society (WSIS) action lines and the SDGs. Approved projects will be officially registered in the repository database.

Benefits of participation on the AI Repository include:

WSIS Prizes recognize individuals, governments, civil society, local, regional and international agencies, research institutions and private-sector companies for outstanding success in implementing development oriented strategies that leverage the power of AI and ICTs.

Creating the AI Repository was one of the action items of last year’s AI for Good Global Summit.

We are looking forward to your submissions.

If you have any questions, please send an email to: ai@itu.int

“Your project won’t be visible immediately as we have to vet the submissions to weed out spam-type material and projects that are not in line with our goals,” says Werner. That said, there are already 29 projects in the repository. As you might expect, the UK, China, and US are in the repository but also represented are Egypt, Uganda, Belarus, Serbia, Peru, Italy, and other countries not commonly cited when discussing AI research.

Werner also pointed out in response to my surprise over the ITU’s role with regard to this AI initiative that the ITU is the only UN agency which has 192* member states (countries), 150 universities, and over 700 industry members as well as other member entities, which gives them tremendous breadth of reach. As well, the organization, founded originally in 1865 as the International Telegraph Convention, has extensive experience with global standardization in the information technology and telecommunications industries. (See more in their Wikipedia entry.)

Finally

There is a bit more about the summit on the ITU’s AI for Good Global Summit 2018 webpage,

The 2nd edition of the AI for Good Global Summit will be organized by ITU in Geneva on 15-17 May 2018, in partnership with XPRIZE Foundation, the global leader in incentivized prize competitions, the Association for Computing Machinery (ACM) and sister United Nations agencies including UNESCO, UNICEF, UNCTAD, UNIDO, Global Pulse, UNICRI, UNODA, UNIDIR, UNODC, WFP, IFAD, UNAIDS, WIPO, ILO, UNITAR, UNOPS, OHCHR, UN UniversityWHO, UNEP, ICAO, UNDP, The World Bank, UN DESA, CTBTOUNISDRUNOG, UNOOSAUNFPAUNECE, UNDPA, and UNHCR.

The AI for Good series is the leading United Nations platform for dialogue on AI. The action​​-oriented 2018 summit will identify practical applications of AI and supporting strategies to improve the quality and sustainability of life on our planet. The summit will continue to formulate strategies to ensure trusted, safe and inclusive development of AI technologies and equitable access to their benefits.

While the 2017 summit sparked the first ever inclusive global dialogue on beneficial AI, the action-oriented 2018 summit will focus on impactful AI solutions able to yield long-term benefits and help achieve the Sustainable Development Goals. ‘Breakthrough teams’ will demonstrate the potential of AI to map poverty and aid with natural disasters using satellite imagery, how AI could assist the delivery of citizen-centric services in smart cities, and new opportunities for AI to help achieve Universal Health Coverage, and finally to help achieve transparency and explainability in AI algorithms.

Teams will propose impactful AI strategies able to be enacted in the near term, guided by an expert audience of mentors representing government, industry, academia and civil society. Strategies will be evaluated by the mentors according to their feasibility and scalability, potential to address truly global challenges, degree of supporting advocacy, and applicability to market failures beyond the scope of government and industry. The exercise will connect AI innovators with public and private-sector decision-makers, building collaboration to take promising strategies forward.

“As the UN specialized agency for information and communication technologies, ITU is well placed to guide AI innovation towards the achievement of the UN Sustainable Development ​Goals. We are providing a neutral close quotation markplatform for international dialogue aimed at ​building a ​common understanding of the capabilities of emerging AI technologies.​​” Houlin Zhao, Secretary General ​of ITU​

Should you be close to Geneva, it seems that registration is still open. Just go to the ITU’s AI for Good Global Summit 2018 webpage, scroll the page down to ‘Documentation’ and you will find a link to the invitation and a link to online registration. Participation is free but I expect that you are responsible for your travel and accommodation costs.

For anyone unable to attend in person, the summit will be livestreamed (webcast in real time) and you can watch the sessions by following the link below,

https://www.itu.int/en/ITU-T/AI/2018/Pages/webcast.aspx

For those of us on the West Coast of Canada and other parts distant to Geneva, you will want to take the nine hour difference between Geneva (Switzerland) and here into account when viewing the proceedings. If you can’t manage the time difference, the sessions are being recorded and will be posted at a later date.

*’132 member states’ corrected to ‘192 member states’ on May 11, 2018 at 1500 hours PDT.

*Redundant ‘and’ removed on July 19, 2018.

CRISPR-CAS9 and gold

As so often happens in the sciences, now that the initial euphoria has expended itself problems (and solutions) with CRISPR ((clustered regularly interspaced short palindromic repeats))-CAAS9 are being disclosed to those of us who are not experts. From an Oct. 3, 2017 article by Bob Yirka for phys.org,

A team of researchers from the University of California and the University of Tokyo has found a way to use the CRISPR gene editing technique that does not rely on a virus for delivery. In their paper published in the journal Nature Biomedical Engineering, the group describes the new technique, how well it works and improvements that need to be made to make it a viable gene editing tool.

CRISPR-Cas9 has been in the news a lot lately because it allows researchers to directly edit genes—either disabling unwanted parts or replacing them altogether. But despite many success stories, the technique still suffers from a major deficit that prevents it from being used as a true medical tool—it sometimes makes mistakes. Those mistakes can cause small or big problems for a host depending on what goes wrong. Prior research has suggested that the majority of mistakes are due to delivery problems, which means that a replacement for the virus part of the technique is required. In this new effort, the researchers report that they have discovered just a such a replacement, and it worked so well that it was able to repair a gene mutation in a Duchenne muscular dystrophy mouse model. The team has named the new technique CRISPR-Gold, because a gold nanoparticle was used to deliver the gene editing molecules instead of a virus.

An Oct. 2, 2017 article by Abby Olena for The Scientist lays out the CRISPR-CAS9 problems the scientists are trying to solve (Note: Links have been removed),

While promising, applications of CRISPR-Cas9 gene editing have so far been limited by the challenges of delivery—namely, how to get all the CRISPR parts to every cell that needs them. In a study published today (October 2) in Nature Biomedical Engineering, researchers have successfully repaired a mutation in the gene for dystrophin in a mouse model of Duchenne muscular dystrophy by injecting a vehicle they call CRISPR-Gold, which contains the Cas9 protein, guide RNA, and donor DNA, all wrapped around a tiny gold ball.

The authors have made “great progress in the gene editing area,” says Tufts University biomedical engineer Qiaobing Xu, who did not participate in the work but penned an accompanying commentary. Because their approach is nonviral, Xu explains, it will minimize the potential off-target effects that result from constant Cas9 activity, which occurs when users deliver the Cas9 template with a viral vector.

Duchenne muscular dystrophy is a degenerative disease of the muscles caused by a lack of the protein dystrophin. In about a third of patients, the gene for dystrophin has small deletions or single base mutations that render it nonfunctional, which makes this gene an excellent candidate for gene editing. Researchers have previously used viral delivery of CRISPR-Cas9 components to delete the mutated exon and achieve clinical improvements in mouse models of the disease.

“In this paper, we were actually able to correct [the gene for] dystrophin back to the wild-type sequence” via homology-directed repair (HDR), coauthor Niren Murthy, a drug delivery researcher at the University of California, Berkeley, tells The Scientist. “The other way of treating this is to do something called exon skipping, which is where you delete some of the exons and you can get dystrophin to be produced, but it’s not [as functional as] the wild-type protein.”

The research team created CRISPR-Gold by covering a central gold nanoparticle with DNA that they modified so it would stick to the particle. This gold-conjugated DNA bound the donor DNA needed for HDR, which the Cas9 protein and guide RNA bound to in turn. They coated the entire complex with a polymer that seems to trigger endocytosis and then facilitate escape of the Cas9 protein, guide RNA, and template DNA from endosomes within cells.

In order to do HDR, “you have to provide the cell [with] the Cas9 enzyme, guide RNA by which you target Cas9 to a particular part of the genome, and a big chunk of DNA, which will be used as a template to edit the mutant sequence to wild-type,” explains coauthor Irina Conboy, who studies tissue repair at the University of California, Berkeley. “They all have to be present at the same time and at the same place, so in our system you have a nanoparticle which simultaneously delivers all of those three key components in their active state.”

Olena’s article carries on to describe how the team created CRISPR-Gold and more.

Additional technical details are available in an Oct. 3, 2017 University of California at Berkeley news release by Brett Israel (also on EurekAlert), which originated the news item (Note: A link has been removed) ,

Scientists at the University of California, Berkeley, have engineered a new way to deliver CRISPR-Cas9 gene-editing technology inside cells and have demonstrated in mice that the technology can repair the mutation that causes Duchenne muscular dystrophy, a severe muscle-wasting disease. A new study shows that a single injection of CRISPR-Gold, as the new delivery system is called, into mice with Duchenne muscular dystrophy led to an 18-times-higher correction rate and a two-fold increase in a strength and agility test compared to control groups.

Diagram of CRISPR-Gold

CRISPR–Gold is composed of 15 nanometer gold nanoparticles that are conjugated to thiol-modified oligonucleotides (DNA-Thiol), which are hybridized with single-stranded donor DNA and subsequently complexed with Cas9 and encapsulated by a polymer that disrupts the endosome of the cell.

Since 2012, when study co-author Jennifer Doudna, a professor of molecular and cell biology and of chemistry at UC Berkeley, and colleague Emmanuelle Charpentier, of the Max Planck Institute for Infection Biology, repurposed the Cas9 protein to create a cheap, precise and easy-to-use gene editor, researchers have hoped that therapies based on CRISPR-Cas9 would one day revolutionize the treatment of genetic diseases. Yet developing treatments for genetic diseases remains a big challenge in medicine. This is because most genetic diseases can be cured only if the disease-causing gene mutation is corrected back to the normal sequence, and this is impossible to do with conventional therapeutics.

CRISPR/Cas9, however, can correct gene mutations by cutting the mutated DNA and triggering homology-directed DNA repair. However, strategies for safely delivering the necessary components (Cas9, guide RNA that directs Cas9 to a specific gene, and donor DNA) into cells need to be developed before the potential of CRISPR-Cas9-based therapeutics can be realized. A common technique to deliver CRISPR-Cas9 into cells employs viruses, but that technique has a number of complications. CRISPR-Gold does not need viruses.

In the new study, research lead by the laboratories of Berkeley bioengineering professors Niren Murthy and Irina Conboy demonstrated that their novel approach, called CRISPR-Gold because gold nanoparticles are a key component, can deliver Cas9 – the protein that binds and cuts DNA – along with guide RNA and donor DNA into the cells of a living organism to fix a gene mutation.

“CRISPR-Gold is the first example of a delivery vehicle that can deliver all of the CRISPR components needed to correct gene mutations, without the use of viruses,” Murthy said.

The study was published October 2 [2017] in the journal Nature Biomedical Engineering.

CRISPR-Gold repairs DNA mutations through a process called homology-directed repair. Scientists have struggled to develop homology-directed repair-based therapeutics because they require activity at the same place and time as Cas9 protein, an RNA guide that recognizes the mutation and donor DNA to correct the mutation.

To overcome these challenges, the Berkeley scientists invented a delivery vessel that binds all of these components together, and then releases them when the vessel is inside a wide variety of cell types, triggering homology directed repair. CRISPR-Gold’s gold nanoparticles coat the donor DNA and also bind Cas9. When injected into mice, their cells recognize a marker in CRISPR-Gold and then import the delivery vessel. Then, through a series of cellular mechanisms, CRISPR-Gold is released into the cells’ cytoplasm and breaks apart, rapidly releasing Cas9 and donor DNA.

Schematic of CRISPR-Gold's method of action

CRISPR-Gold’s method of action (Click to enlarge).

A single injection of CRISPR-Gold into muscle tissue of mice that model Duchenne muscular dystrophy restored 5.4 percent of the dystrophin gene, which causes the disease, to the wild- type, or normal, sequence. This correction rate was approximately 18 times higher than in mice treated with Cas9 and donor DNA by themselves, which experienced only a 0.3 percent correction rate.

Importantly, the study authors note, CRISPR-Gold faithfully restored the normal sequence of dystrophin, which is a significant improvement over previously published approaches that only removed the faulty part of the gene, making it shorter and converting one disease into another, milder disease.

CRISPR-Gold was also able to reduce tissue fibrosis – the hallmark of diseases where muscles do not function properly – and enhanced strength and agility in mice with Duchenne muscular dystrophy. CRISPR-Gold-treated mice showed a two-fold increase in hanging time in a common test for mouse strength and agility, compared to mice injected with a control.

“These experiments suggest that it will be possible to develop non-viral CRISPR therapeutics that can safely correct gene mutations, via the process of homology-directed repair, by simply developing nanoparticles that can simultaneously encapsulate all of the CRISPR components,” Murthy said.

CRISPR-Cas9

CRISPR in action: A model of the Cas9 protein cutting a double-stranded piece of DNA

The study found that CRISPR-Gold’s approach to Cas9 protein delivery is safer than viral delivery of CRISPR, which, in addition to toxicity, amplifies the side effects of Cas9 through continuous expression of this DNA-cutting enzyme. When the research team tested CRISPR-Gold’s gene-editing capability in mice, they found that CRISPR-Gold efficiently corrected the DNA mutation that causes Duchenne muscular dystrophy, with minimal collateral DNA damage.

The researchers quantified CRISPR-Gold’s off-target DNA damage and found damage levels similar to the that of a typical DNA sequencing error in a typical cell that was not exposed to CRISPR (0.005 – 0.2 percent). To test for possible immunogenicity, the blood stream cytokine profiles of mice were analyzed at 24 hours and two weeks after the CRISPR-Gold injection. CRISPR-Gold did not cause an acute up-regulation of inflammatory cytokines in plasma, after multiple injections, or weight loss, suggesting that CRISPR-Gold can be used multiple times safely, and that it has a high therapeutic window for gene editing in muscle tissue.

“CRISPR-Gold and, more broadly, CRISPR-nanoparticles open a new way for safer, accurately controlled delivery of gene-editing tools,” Conboy said. “Ultimately, these techniques could be developed into a new medicine for Duchenne muscular dystrophy and a number of other genetic diseases.”

A clinical trial will be needed to discern whether CRISPR-Gold is an effective treatment for genetic diseases in humans. Study co-authors Kunwoo Lee and Hyo Min Park have formed a start-up company, GenEdit (Murthy has an ownership stake in GenEdit), which is focused on translating the CRISPR-Gold technology into humans. The labs of Murthy and Conboy are also working on the next generation of particles that can deliver CRISPR into tissues from the blood stream and would preferentially target adult stem cells, which are considered the best targets for gene correction because stem and progenitor cells are capable of gene editing, self-renewal and differentiation.

“Genetic diseases cause devastating levels of mortality and morbidity, and new strategies for treating them are greatly needed,” Murthy said. “CRISPR-Gold was able to correct disease-causing gene mutations in vivo, via the non-viral delivery of Cas9 protein, guide RNA and donor DNA, and therefore has the potential to develop into a therapeutic for treating genetic diseases.”

The study was funded by the National Institutes of Health, the W.M. Keck Foundation, the Moore Foundation, the Li Ka Shing Foundation, Calico, Packer, Roger’s and SENS, and the Center of Innovation (COI) Program of the Japan Science and Technology Agency.

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

Nanoparticle delivery of Cas9 ribonucleoprotein and donor DNA in vivo induces homology-directed DNA repair by Kunwoo Lee, Michael Conboy, Hyo Min Park, Fuguo Jiang, Hyun Jin Kim, Mark A. Dewitt, Vanessa A. Mackley, Kevin Chang, Anirudh Rao, Colin Skinner, Tamanna Shobha, Melod Mehdipour, Hui Liu, Wen-chin Huang, Freeman Lan, Nicolas L. Bray, Song Li, Jacob E. Corn, Kazunori Kataoka, Jennifer A. Doudna, Irina Conboy, & Niren Murthy. Nature Biomedical Engineering (2017) doi:10.1038/s41551-017-0137-2 Published online: 02 October 2017

This paper is behind a paywall.

Cleaning up disasters with Hokusai’s blue and cellulose nanofibers to clean up contaminated soil and water in Fukushima

The Great Wave off Kanagawa (Under a wave off Kanagawa”), also known as The Great Wave or simply The Wave, by Katsushika Hokusai – Metropolitan Museum of Art, online database: entry 45434, Public Domain, https://commons.wikimedia.org/w/index.php?curid=2798407

I thought it might be a good idea to embed a copy of Hokusai’s Great Wave and the blue these scientists in Japan have used as their inspiration. (By the way, it seems these scientists collaborated with Mildred Dresselhaus who died at the age of 86, a few months after their paper was published. In honour of he and before the latest, here’s my Feb. 23, 2017 posting about the ‘Queen of Carbon’.)

Now onto more current news, from an Oct. 13, 2017 news item on Nanowerk (Note: A link has been removed),

By combining the same Prussian blue pigment used in the works of popular Edo-period artist Hokusai and cellulose nanofiber, a raw material of paper, a University of Tokyo research team succeeded in synthesizing compound nanoparticles, comprising organic and inorganic substances (Scientific Reports, “Cellulose nanofiber backboned Prussian blue nanoparticles as powerful adsorbents for the selective elimination of radioactive cesium”). This new class of organic/inorganic composite nanoparticles is able to selectively adsorb, or collect on the surface, radioactive cesium.

The team subsequently developed sponges from these nanoparticles that proved highly effective in decontaminating the water and soil in Fukushima Prefecture exposed to radioactivity following the nuclear accident there in March 2011.

I think these are the actual sponges not an artist’s impression,

Decontamination sponge spawned from current study
Cellulose nanofiber-Prussian blue compounds are permanently anchored in spongiform chambers (cells) in this decontamination sponge. It can thus be used as a powerful adsorbent for selectively eliminating radioactive cesium. © 2017 Sakata & Mori Laboratory.

An Oct. 13, 2017 University of Tokyo press release, which originated the news item, provides more detail about the sponges and the difficulties of remediating radioactive air and soil,

Removing radioactive materials such as cesium-134 and -137 from contaminated seawater or soil is not an easy job. First of all, a huge amount of similar substances with competing functions has to be removed from the area, an extremely difficult task. Prussian blue (ferric hexacyanoferrate) has a jungle gym-like colloidal structure, and the size of its single cubic orifice, or opening, is a near-perfect match to the size of cesium ions; therefore, it is prescribed as medication for patients exposed to radiation for selectively adsorbing cesium. However, as Prussian blue is highly attracted to water, recovering it becomes highly difficult once it is dissolved into the environment; for this reason, its use in the field for decontamination has been limited.

Taking a hint from the Prussian blue in Hokusai’s woodblock prints not losing their color even when getting wet from rain, the team led by Professor Ichiro Sakata and Project Professor Bunshi Fugetsu at the University of Tokyo’s Nanotechnology Innovation Research Unit at the Policy Alternatives Research Institute, and Project Researcher Adavan Kiliyankil Vipin at the Graduate School of Engineering developed an insoluble nanoparticle obtained from combining cellulose and Prussian blue—Hokusai had in fact formed a chemical bond in his handling of Prussian blue and paper (cellulose).

The scientists created this cellulose-Prussian blue combined nanoparticle by first preparing cellulose nanofibers using a process called TEMPO oxidization and securing ferric ions (III) onto them, then introduced a certain amount of hexacyanoferrate, which adhered to Prussian blue nanoparticles with a diameter ranging from 5–10 nanometers. The nanoparticles obtained in this way were highly resistant to water, and moreover, were capable of adsorbing 139 mg of radioactive cesium ion per gram.

Field studies on soil decontamination in Fukushima have been underway since last year. A highly effective approach has been to sow and allow plant seeds to germinate inside the sponge made from the nanoparticles, then getting the plants’ roots to take up cesium ions from the soil to the sponge. Water can significantly shorten decontamination times compared to soil, which usually requires extracting cesium from it with a solvent.

It has been more than six years since the radioactive fallout from a series of accidents at the Fukushima Daiichi nuclear power plant following the giant earthquake and tsunami in northeastern Japan. Decontamination with the cellulose nanofiber-Prussian blue compound can lead to new solutions for contamination in disaster-stricken areas.

“I was pondering about how Prussian blue immediately gets dissolved in water when I happened upon a Hokusai woodblock print, and how the indigo color remained firmly set in the paper, without bleeding, even after all these years,” reflects Fugetsu. He continues, “That revelation provided a clue for a solution.”

“The amount of research on cesium decontamination increased after the Chernobyl nuclear power plant accident, but a lot of the studies were limited to being academic and insufficient for practical application in Fukushima,” says Vipin. He adds, “Our research offers practical applications and has high potential for decontamination on an industrial scale not only in Fukushima but also in other cesium-contaminated areas.”

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

Cellulose nanofiber backboned Prussian blue nanoparticles as powerful adsorbents for the selective elimination of radioactive cesium by Adavan Kiliyankil Vipin, Bunshi Fugetsu, Ichiro Sakata, Akira Isogai, Morinobu Endo, Mingda Li, & Mildred S. Dresselhaus. Scientific Reports 6, Article number: 37009 (2016) doi:10.1038/srep37009 Published online: 15 November 2016

This is open access.