It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Tuesday, July 18, 2023
The future of recycling could one day mean dissolving plastic with electricity
Chemists at CU Boulder have developed a new way to recycle a common type of plastic found in soda bottles and other packaging. The team's method relies on electricity and some nifty chemical reactions, and it's simple enough that you can watch the plastic break apart in front of your eyes.
The researchers described their new approach to chemical recycling in the journal Chem Catalysis.
The study tackles the mounting problem of plastic trash around the world. According to the Environmental Protection Agency, the United States alone produced nearly 36 million tons of plastic products in 2018. A majority of the waste winds up in landfills, said study co-author Oana Luca.
"We pat ourselves on the back when we toss something into the recycling bin, but most of that recyclable plastic never winds up being recycled," said Luca, assistant professor in the Department of Chemistry. "We wanted to find out how we could recover molecular materials, the building blocks of plastics, so that we can use them again."
In the new research, she and her colleagues got one step closer to doing just that.
The group focused on a type of plastic called polyethylene terephthalate (PET), which consumers encounter every day in water bottles, blister packs and even some polyester fabrics. In small-scale lab experiments, the researchers mixed bits of that plastic with a special kind of molecule then applied a small electric voltage. Within minutes, the PET began to disintegrate.
The team has a lot more work to do before its recycling tool can take a realistic bite out of the world's plastic trash problem. But it was still fun to watch the waste, which can stick around in garbage piles for centuries, disappear in a matter of hours or days, said study lead author Phuc Pham.
"It was awesome to actually observe the reaction progress in real time," said Pham, a doctoral student in chemistry. "The solution first turns a deep pink color, then becomes clear as the polymer breaks apart."
One person's trash
Luca said it's a whole new way of thinking about the possibilities of trash. Recycling bins, she noted, may look like a good solution to the world's plastics problem. But most municipalities around the world have struggled to collect and sort the small mountain of rubbish that people produce every day. The result: Less than one-third of all PET plastic in the U.S. comes close to being recycled (other types of plastic lag even farther behind). Even then, methods like melting plastic waste or dissolving it in acid can alter the material properties in the process.
In a lab on campus, Phuc Pham applies electricity to a solution containing ground up PET plastic. The solution turns pink as the plastic begins to dissolve. The final step in the proccess is exposing the solution to oxygen, which turns it yellow and eventually back to clear as the plastic fully breaks down. Credit: University of Colorado at Boulder
"You end up changing the materials mechanically," Luca said. "Using current methods of recycling, if you melt a plastic bottle, you can produce, for example, one of those disposable plastic bags that we now have to pay money for at the grocery store."
She and her team, in contrast, want to find a way to use the basic ingredients from old plastic bottles to make new plastic bottles. It's like smashing your Lego castle so that you can retrieve the blocks to create a whole new building.
Another's treasure
To achieve that feat, the group turned to a process called electrolysis—or using electricity to break apart molecules. Chemists, for example, have long known that they can apply a voltage to beakers filled with water and salts to split those water molecules into hydrogen and oxygen gas.
But PET plastic is a lot harder to divide than water. In the new study, Pham ground up plastic bottles then mixed the powder into a solution. Next, he and his colleagues added an extra ingredient, a molecule known as [N-DMBI]+ salt, to the solution. Pham explained that in the presence of electricity, this molecule forms a "reactive mediator" that can donate its extra electron to the PET, causing the grains of plastic to come undone. Think of it like the chemistry equivalent of delivering a karate chop to a wooden board.
The researchers are still trying to understand how exactly these reactions take place, but they were able to break down the PET into its basic building blocks—which the group could then recover and, potentially, use to make something new.
Deploying only tabletop equipment in their lab, the researchers reported that they could break down about 40 milligrams (a small pinch) of PET over several hours.
"Although this is a great start, we believe that lots of work needs to be done to optimize the process as well as scale it up so it can eventually be applied on an industrial scale," Pham said.
Luca, at least, has some big-picture ideas for the technology.
"If I were to have my way as a mad scientist, I would use these electrochemical methods to break down many different kinds of plastic at once," Luca said. "That way, you could, for example, go to these massive garbage patches in the ocean, pull all of that waste into a reactor and get a lot of useful molecules back."
More information: Phuc H. Pham et al, Electricity-driven recycling of ester plastics using one-electron electro-organocatalysis, Chem Catalysis (2023). DOI: 10.1016/j.checat.2023.100675
A protester holds an altered Brittany flag during a demonstration in Rennes, western France, on March 22. (AFP via Getty Images)
Widespread protests in France are not uncommon. In fact, they are an ingrained part of the country's history dating back to the French Revolution. But the last few months have been especially rattling and have cast a shadow over the planning and execution of next summer's Olympic Games in Paris.
First the country was paralyzed in January by pension protests directed at French President Emmanuel Macron's decision to raise the legal retirement age by two years to 64.
The constant refrain of demonstrators was "No withdrawal, no Olympics."
Then this month, thousands of people took to the streets after the police shot and killed 17-year-old Nahel Merzouk, a French citizen of Moroccan and Algerian descent, as he attempted to flee a traffic stop in a Paris suburb.
In the wake of the killing, mass riots broke out in cities across the country, driven by a long-standing tension between French police and many of the country's racialized population. Thousands of cars and buildings were destroyed. Calm has only been restored in recent days and came only with the deployment of thousands of police.
Spectators hold a banner that reads 'Justice for Nahel' along the race route at the start of the first stage of the 110th edition of the Tour de France cycling race on July 1. Nahel was the teen killed by police during a traffic stop in a Paris suburb on June 27. (AFP via Getty Images)
'Politics through different means'
"Protests are more common in France than in many other democracies. So it seems more common in France that important political issues are resolved after big protests rather than in parliaments," says Johannes Lindval, a political science professor at the University of Gothenburg.
"The regular ways of expressing political opinions and being represented in politics are sort of closed off in France more than in other comparable countries in this region. Therefore people feel that they have to kind of participate in politics through a different means."
Both of these protests have already affected France's Olympic efforts.
During the pension riots, a French labour union cut power to numerous Olympic sites, including the main Olympic Stadium and the Olympic Village. Protesters even briefly occupied the Olympic organizing committee offices.
The widespread protests seen over the past few weeks left the Olympic Aquatic Training Centre, which was under construction, badly burned.
Organizers and Olympics officials are downplaying any impact these events could have on the Games.
"We have learnt with regret about the recent incidents in France," an IOC spokesperson told Reuters. "We have full confidence in the organizing committee and the French authorities to deliver successful Olympic and Paralympic Games and in the hospitality of the French people to welcome the world to these Games."
"We're still a year away from the Games," said Emmanuel Gregoire, First Deputy Mayor of Paris. "We shouldn't get our calendars mixed up."
But some experts say officials should pay close attention to what is happening.
Black says the racial and economic divisions in French society could easily be further inflamed by the Olympics, which he says are increasingly a microcosm of broader society.
"I think there's a degree to which people see the Olympic Games, which were originally in the spirit of being anti-commercial and in the spirit of amateurism, of brotherhood or sisterhood," Black says. "And now really reflecting the broader economy where you have the IOC, which many people see as a kind of antidemocratic rich elite who operate with little accountability."
Angela Schneider, director of Western University's International Centre for Olympic Studies, agrees the French population's propensity for demonstrations brings special considerations.
"I do think there is a special strength to the French people and their kind of demonstrations. So it is something that merits consideration and planning," Schneider says. "I do think having the big stage does motivate some people who don't feel they get the attention that they would have gotten without that, so I think [officials] will have to contend with that. These things can blow up and balloon out quite unexpectedly at times."
At the same time, Schneider says there are a number of factors that could insulate the Paris Games from wider unrest in the country.
There appears to be widespread support for the Olympics in France beyond the recent protests. Four million applicants signed up for the initial ticket draw and more than 200,000 candidates applied to fill the 45,000 volunteer positions needed for the Games.
Then there is France's deep connection to the Game, dating back to the founder of the modern Olympics, Frenchman Pierre de Coubertin.
"The history of the Games themselves and the role of France and de Coubertin, the French are extremely proud of that," Schneider says. "So that weighs heavily. It's worth thinking about when we think about the Olympics in the context of social demonstrations." Riots ahead of London 2012 Olympics
The Paris Olympics won't be the first or last to take place in the context of wider domestic or international conflict, strife or protest.
In London in 2011, a year before it hosted the Games, the city dealt with a similar set of circumstances that played out this summer in Paris. Riots broke out after British police shot Mark Duggan, a 29-year-old Black man, during a traffic stop. The resulting violence left five people dead and millions of dollars in damage.
British Olympic Association chairman Sir Hugh Robertson, who was Britain's Minister of Sport and Olympics, offered this advice to French officials.
"Stay calm and keep focused. The organizers have my sympathy and I am sure that they will sort this out," Robertson told AFP. "We are still over a year out from the opening ceremony, which is a very long time in the course of organizing something as big as the Olympic Games."
Innovative Supply Chain Model Marks A New Era For Hydrogen
Hydrogen has been touted as the clean fuel of the future; it can be extracted from water and produces zero carbon emissions. However, it is currently expensive to transport over long distances, and currently no infrastructure is in place to do so.
The new supply chain model, created by researchers in Australia, Singapore and Germany, successfully guides the development of international transport of hydrogen and its embodied energy.
Associate Professor Kaveh Khalilpour, from the University of Technology Sydney (UTS) and lead of the report, said supply chain design is critical for making hydrogen economic.
“We looked at the renewable hydrogen export from Australia to Singapore, Japan, and Germany. Surprisingly, the analysis revealed that it matters whether the goal is to export ‘hydrogen the atom’ or ‘hydrogen the energy’. Each choice leads to a different supply chain system. Therefore, a thorough understanding of the whole system is necessary for correct decision making,” said Associate Professor Khalilpour. “The abundance of renewable energy resources in Australia, as well as its stable economy, means the country can attract investments in building these green value chains in our region and even as far away as Europe.”
Hydrogen is expected to help diversify Australia’s renewable energy resource beyond solar and wind power. This is seen as critical to the country’s energy security, as well as necessary for climate change mitigation.
Professor Reinhard Madlener, co-lead of the project, from RWTH Aachen University, Germany said, “Hydrogen is just an energy carrier, i.e. not a primary energy source, and thus only a means to an end for transporting renewable energy from one place to another. The key business question around the emerging hydrogen economy is whether commodities such as green hydrogen, methanol or ammonia can be exported profitably and competitively also over long distances and across the oceans, thus bringing green energy to other places in the world. If this is so, this will also have major international energy and climate policy implications,”
Professor Iftekhar Karimi, from the National University of Singapore, and co-lead of the project said, “Our model suggests that methanol shows great promise as a chemical carrier for exporting renewable energy from Australia at low costs.”
***
It is very encouraging to see some good sense come into the discussion about hydrogen, its storage and transport.. While the press release is using the word “new”, the connection of hydrogen atoms to carbon and nitrogen has been done by nature for hundreds of millions if not billions of years. These examples are just two of thousands.
Another major plus is that fuel cell tech is already existent for methanol. The technology may have had to go to the back burner due media and political pressure about the carbon content in methanol, but its excellent technology, a liquid fuel, does not require pressurization nor has especially dangerous attributes.
The downside is that the mentioned carriers are low in energy content compared to some heavier fossil fuel products. But that probably wouldn’t be a market killer if the efficiency is high enough.
Lets hope that down to earth practical applications can muscle in over the way out there ideas about energy and fuel products.
By Brian Westenhaus via New Energy and Fuel
AI
Researchers develop AI model to better predict which drugs may cause birth defects
Data harnessed to identify previously unknown associations between genes, congenital disabilities, and drugs
THE MOUNT SINAI HOSPITAL / MOUNT SINAI SCHOOL OF MEDICINE
IMAGE: TO PROVIDE ACCESS TO THE DATA USED TO CREATE THE NEW AI MODEL, THE RESEARCHERS DEVELOPED A WEBSITE THAT ENABLES USERS TO EXPLORE RELATIONSHIPS BETWEEN GENES, DRUGS, AND BIRTH DEFECTS.view more
CREDIT: MA’AYAN ET AL., COMMUNICATIONS MEDICINE HTTPS://CREATIVECOMMONS.ORG/LICENSES/BY/4.0/.
New York, NY (July 17, 2023)—Data scientists at the Icahn School of Medicine at Mount Sinai in New York and colleagues have created an artificial intelligence model that may more accurately predict which existing medicines, not currently classified as harmful, may in fact lead to congenital disabilities.
The model, or “knowledge graph,” described in the July 17 issue of the Naturejournal Communications Medicine [DOI: 10.1038/s43856-023-00329-2], also has the potential to predict the involvement of pre-clinical compounds that may harm the developing fetus. The study is the first known of its kind to use knowledge graphs to integrate various data types to investigate the causes of congenital disabilities.
Birth defects are abnormalities that affect about 1 in 33 births in the United States. They can be functional or structural and are believed to result from various factors, including genetics. However, the causes of most of these disabilities remain unknown. Certain substances found in medicines, cosmetics, food, and environmental pollutants can potentially lead to birth defects if exposed during pregnancy.
“We wanted to improve our understanding of reproductive health and fetal development, and importantly, warn about the potential of new drugs to cause birth defects before these drugs are widely marketed and distributed,” says Avi Ma’ayan, PhD, Professor, Pharmacological Sciences, and Director of the Mount Sinai Center for Bioinformatics at Icahn Mount Sinai, and senior author of the paper. “Although identifying the underlying causes is a complicated task, we offer hope that through complex data analysis like this that integrates evidence from multiple sources, we will be able, in some cases, to better predict, regulate, and protect against the significant harm that congenital disabilities could cause.”
The researchers gathered knowledge across several datasets on birth-defect associations noted in published work, including those produced by NIH Common Fund programs, to demonstrate how integrating data from these resources can lead to synergistic discoveries. Particularly, the combined data is from the known genetics of reproductive health, classification of medicines based on their risk during pregnancy, and how drugs and pre-clinical compounds affect the biological mechanisms inside human cells.
Specifically, the data included studies on genetic associations, drug- and preclinical-compound-induced gene expression changes in cell lines, known drug targets, genetic burden scores for human genes, and placental crossing scores for small molecule drugs.
Importantly, using ReproTox-KG, with semi-supervised learning (SSL), the research team prioritized 30,000 preclinical small molecule drugs for their potential to cross the placenta and induce birth defects. SSL is a branch of machine learning that uses a small amount of labeled data to guide predictions for much larger unlabeled data. In addition, by analyzing the topology of the ReproTox-KG more than 500 birth-defect/gene/drug cliques were identified that could explain molecular mechanisms that underlie drug-induced birth defects. In graph theory terms, cliques are subsets of a graph where all the nodes in the clique are directly connected to all other nodes in the clique.
The investigators caution that the study's findings are preliminary and that further experiments are needed for validation.
Next, the investigators plan to use a similar graph-based approach for other projects focusing on the relationship between genes, drugs, and diseases. They also aim to use the processed dataset as training materials for courses and workshops on bioinformatics analysis. In addition, they plan to extend the study to consider more complex data, such as gene expression from specific tissues and cell types collected at multiple stages of development.
“We hope that our collaborative work will lead to a new global framework to assess potential toxicity for new drugs and explain the biological mechanisms by which some drugs, known to cause birth defects, may operate. It’s possible that at some point in the future, regulatory agencies such as the U.S. Food and Drug Administration and the U.S. Environmental Protection Agency may use this approach to evaluate the risk of new drugs or other chemical applications,” says Dr. Ma’ayan.
The paper is titled “Toxicology Knowledge Graph for Structural Birth Defects.”
Additional co-authors are John Erol Evangelista (Icahn Mount Sinai), Daniel J. B. Clarke (Icahn Mount Sinai), Zhuorui Xie (Icahn Mount Sinai), Giacomo B. Marino, (Icahn Mount Sinai), Vivian Utti (Icahn Mount Sinai), Sherry L. Jenkins (Icahn Mount Sinai), Taha Mohseni Ahooyi (Children’s Hospital of Philadelphia), Cristian G. Bologa (University of New Mexico), Jeremy J. Yang (University of New Mexico), Jessica L. Binder (University of New Mexico), Praveen Kumar (University of New Mexico), Christophe G. Lambert (University of New Mexico), Jeffrey S. Grethe (University of California San Diego), Eric Wenger (Children’s Hospital of Philadelphia), Deanne Taylor, (Children’s Hospital of Philadelphia), Tudor I. Oprea (Children’s Hospital of Philadelphia), and Bernard de Bono (University of Auckland, New Zealand).
The project was supported by National Institutes of Health grants OT2OD030160, OT2OD030546, OT2OD032619, and OT2OD030162.
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About the Icahn School of Medicine at Mount Sinai
The Icahn School of Medicine at Mount Sinai is internationally renowned for its outstanding research, educational, and clinical care programs. It is the sole academic partner for the eight- member hospitals* of the Mount Sinai Health System, one of the largest academic health systems in the United States, providing care to a large and diverse patient population.
Ranked 14th nationwide in National Institutes of Health (NIH) funding and among the 99th percentile in research dollars per investigator according to the Association of American Medical Colleges, Icahn Mount Sinai has a talented, productive, and successful faculty. More than 3,000 full-time scientists, educators, and clinicians work within and across 44 academic departments and 36 multidisciplinary institutes, a structure that facilitates tremendous collaboration and synergy. Our emphasis on translational research and therapeutics is evident in such diverse areas as genomics/big data, virology, neuroscience, cardiology, geriatrics, as well as gastrointestinal and liver diseases.
Icahn Mount Sinai offers highly competitive MD, PhD, and Master’s degree programs, with current enrollment of approximately 1,300 students. It has the largest graduate medical education program in the country, with more than 2,000 clinical residents and fellows training throughout the Health System. In addition, more than 550 postdoctoral research fellows are in training within the Health System.
A culture of innovation and discovery permeates every Icahn Mount Sinai program. Mount Sinai’s technology transfer office, one of the largest in the country, partners with faculty and trainees to pursue optimal commercialization of intellectual property to ensure that Mount Sinai discoveries and innovations translate into healthcare products and services that benefit the public.
Icahn Mount Sinai’s commitment to breakthrough science and clinical care is enhanced by academic affiliations that supplement and complement the School’s programs.
Through the Mount Sinai Innovation Partners (MSIP), the Health System facilitates the real-world application and commercialization of medical breakthroughs made at Mount Sinai. Additionally, MSIP develops research partnerships with industry leaders such as Merck & Co., AstraZeneca, Novo Nordisk, and others.
The Icahn School of Medicine at Mount Sinai is located in New York City on the border between the Upper East Side and East Harlem, and classroom teaching takes place on a campus facing Central Park. Icahn Mount Sinai’s location offers many opportunities to interact with and care for diverse communities. Learning extends well beyond the borders of our physical campus, to the eight hospitals of the Mount Sinai Health System, our academic affiliates, and globally.
* Mount Sinai Health System member hospitals: The Mount Sinai Hospital; Mount Sinai Beth Israel; Mount Sinai Brooklyn; Mount Sinai Morningside; Mount Sinai Queens; Mount Sinai South Nassau; Mount Sinai West; and New York Eye and Ear Infirmary of Mount Sinai.
JOURNAL
Communications Medicine
METHOD OF RESEARCH
Data/statistical analysis
SUBJECT OF RESEARCH
People
ARTICLE TITLE
Toxicology Knowledge Graph for Structural Birth Defects
ARTICLE PUBLICATION DATE
17-Jul-2023
ChatGPT’s responses to people’s healthcare-related queries are nearly indistinguishable from those provided by humans, new study reveals
ChatGPT’s responses to people’s healthcare-related queries are nearly indistinguishable from those provided by humans, a new study from NYU Tandon School of Engineering and Grossman School of Medicine reveals, suggesting the potential for chatbots to be effective allies to healthcare providers’ communications with patients.
An NYU research team presented 392 people aged 18 and above with ten patient questions and responses, with half of the responses generated by a human healthcare provider and the other half by ChatGPT.
Participants were asked to identify the source of each response and rate their trust in the ChatGPT responses using a 5-point scale from completely untrustworthy to completely trustworthy.
The study found people have limited ability to distinguish between chatbot and human-generated responses. On average, participants correctly identified chatbot responses 65.5% of the time and provider responses 65.1% of the time, with ranges of 49.0% to 85.7% for different questions. Results remained consistent no matter the demographic categories of the respondents.
The study found participants mildly trust chatbots’ responses overall (3.4 average score), with lower trust when the health-related complexity of the task in question was higher. Logistical questions (e.g. scheduling appointments, insurance questions) had the highest trust rating (3.94 average score), followed by preventative care (e.g. vaccines, cancer screenings, 3.52 average score). Diagnostic and treatment advice had the lowest trust ratings (scores 2.90 and 2.89, respectively).
According to the researchers, the study highlights the possibility that chatbots can assist in patient-provider communication particularly related to administrative tasks and common chronic disease management. Further research is needed, however, around chatbots' taking on more clinical roles. Providers should remain cautious and exercise critical judgment when curating chatbot-generated advice due to the limitations and potential biases of AI models.
About The Study: History of present illnesses generated by a chatbot or written by senior internal medicine residents were graded similarly by internal medicine attending physicians. These findings underscore the potential of chatbots to aid clinicians with medical documentation.
Authors: Ashwin Nayak, M.D., M.S., of Stanford University in Stanford, California, is the corresponding author.
Editor’s Note: Please see the article for additional information, including other authors, author contributions and affiliations, conflict of interest and financial disclosures, and funding and support.
IMAGE: THE HKUST RESEARCH TEAM DEVELOPED AN AI ESSAY EVALUATOR AESER WHO PARTICIPATES WITH OTHER HUMANS IN A GROUP DISCUSSION TO MARK ESSAYS.view more
CREDIT: HKUST
Artificial intelligence (AI) is all the rage lately in the public eye. How AI is being incorporated to the advantage of our everyday life despite its rapid development, however, remains an elusive topic that deserves the attention of many scientists. While in theory, AI can replace, or even displace, human beings from their positions, the challenge remains on how different industries and institutions can take advantage of this technological advancement and not drown in it.
Recently, a team of researchers at the Hong Kong University of Science and Technology (HKUST) conducted an ambitious study of AI applications on the education front, examining how AI could enhance grading while observing human participants’ behavior in the presence of a computerized companion. They found that teachers were generally receptive to AI’s input - until both sides came to an argument on who should reign supreme. This very much resembles how human beings interact with one another when a new member forays into existing territory.
The research was conducted by HKUST Department of Computer Science and Engineering Ph.D. candidate Chengbo Zheng and four of his teammates under the supervision of Associate Professor Prof. Xiaojuan MA. They developed an AI group member named AESER (Automated Essay ScorER) and separated twenty English teachers into ten groups to investigate the impact of AESER in a group discussion setting, where the AI would contribute in opinion deliberation, asking and answering questions and even voting for the final decision. In this study, designed akin to the controlled “Wizard of Oz” research method, a deep learning model and a human researcher would form joint input to AESER, which would then exchange views and conduct discussions with other participants in an online meeting room.
While the team expected AESER to promote objectivity and provide novel perspectives that would otherwise be overlooked, potential challenges were soon revealed. First, there was the risk of conformity, where the engagement of AI would soon create a majority to thwart discussions. Second, views provided by AESER were found to be rigid and even stubborn, which frustrated the participants when they found that an argument could never be “won”. Many also did not think AI’s input should be given equal weight and are more fit to play the role of an assistant to actual human work.
"At this stage, AI is deemed somewhat 'stubborn' by human collaborators, for good and bad,” noted Prof. Ma. “On the one hand, AI is stubborn so it does not fear to express its opinions frankly and openly. However, human collaborators feel disengaged when they could not meaningfully persuade AI to change its view. Humans varying attitudes towards AI. Some consider it to be a single intelligent entity while others regard AI as the voice of collective intelligence that emerges from big data. Discussions about issues such as authority and bias thus arise.”
The immediate next step for the team involves expanding its scope to gathermore quantitative data, which will provide more measurable and precise insights into how AI impacts group decision-making. They are also looking to explore large language models (LLMs) such as ChatGPT into the study, which could potentially bring new insights and perspectives to group discussions.
Their study was published at the ACM Conference on Human Factors in Computing Systems in April 2023.
The research conducted by HKUST found that AI could bring new perspectives to group discussions.
CREDIT
HKUST
Xiaojuan MA, Associate Professor of the Department of Computer Science and Engineering (CSE), HKUST.
IMAGE: AI IMPRESSION OF ORBITING PARTICLE SPUN BY A ROTATING LIGHT BEAM.view more
CREDIT: MATAN YAH BEN ZION
A team of scientists has devised a system that replicates the movement of naturally occurring phenomena, such as hurricanes and algae, using laser beams and the spinning of microscopic rotors.
The breakthrough, reported in the journal Nature Communications, reveals new ways that living matter can be reproduced on a cellular scale.
“Living organisms are made of materials that actively pump energy through their molecules, which produce a range of movements on a larger cellular scale,” explains Matan Yah Ben Zion, a doctoral student in New York University’s Department of Physics at the time of the work and one of the paper’s authors. “By engineering cellular-scale machines from the ground up, our work can offer new insights into the complexity of the natural world.”
The research centers on vortical flows, which appear in both biological and meteorological systems, such as algae or hurricanes. Specifically, particles move into orbital motion in the flow generated by their own rotation, resulting in a range of complex interactions.
To better understand these dynamics, the paper’s authors, who also included Alvin Modin, an NYU undergraduate at the time of the study and now a doctoral student at Johns Hopkins University, and Paul Chaikin, an NYU physics professor, sought to replicate them at their most basic level. To do so, they created tiny micro-rotors—about 1/10th the width of a strand of human hair—to move micro-particles using a laser beam (Chaikin and his colleagues devised this process in a previous work).
The researchers found that the rotating particles mutually affected each other into orbital motion, with striking similarities to dynamics observed by other scientists in “dancing” algae—algae groupings that move in concert with each other.
In addition, the NYU team found that the spins of the particles reciprocate as the particles orbit.
“The spins of the synthetic particles reciprocate in the same fashion as that observed in algae—in contrast to previous work with artificial micro-rotors,” explains Ben Zion, now a researcher at Tel Aviv University. “So we were able to reproduce synthetically—and on the micron scale—an effect that is seen in living systems.”
“Collectively, these findings suggest that the dance of algae can be reproduced in a synthetic system, better establishing our understanding of living matter,” he adds.
The research was supported by grants from the Department of Energy (DE-SC0007991, SC0020976).
