Sunday, December 04, 2022

COVID-19 has had positive effect on astronomy research, but negative effect on new and female researchers

Peer-Reviewed Publication

KAVLI INSTITUTE FOR THE PHYSICS AND MATHEMATICS OF THE UNIVERSE

authors 

IMAGE: (FROM LEFT) UC BERKELEY POSTDOCTORAL FELLOW VANESSA BOHM (CREDIT:TRAVIS CLOSE) AND KAVLI IPMU PROJECT ASSOCIATE PROFESSOR JIA LIU (CREDIT: KAVLI IPMU). view more 

CREDIT: (FROM LEFT) UC BERKELEY POSTDOCTORAL FELLOW VANESSA BOHM (CREDIT:TRAVIS CLOSE) AND KAVLI IPMU PROJECT ASSOCIATE PROFESSOR JIA LIU (CREDIT: KAVLI IPMU).

The COVID-19 pandemic has had both positive and negative impacts on astronomy research, where overall the number of research papers being produced increased, but the number of new or junior researchers entering the field has dropped. The researchers who carried out the study also found that no single country's female astronomers were able to be more productive than their male colleagues on average, suggests a new study in Nature Astronomy.

In 2021, Project Associate Professor Jia Liu joined the Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU) in Tokyo and settled into a new country and job in amidst a global pandemic. 

”As a new mother and an early career scientist, my life has been heavily affected by the pandemic –– lost childcare, dropped productivity, disconnection from my colleagues, and a tough job market. While rebuilding my research and life routines, I couldn’t stop wondering: how are others in my field affected by the pandemic? Am I alone," said Liu.

Collaborating with University of California, Berkeley, Postdoctoral Fellow Vanessa Böhm, the researchers decided to find out themselves after not finding the answers in the limited studies available at the time.

The computational cosmologists used their data mining skills to download more than 1.2 million records of astronomical publications since 1950. They wanted to analyze publication patterns by gender and country, but such information is confidential. So, the researchers assigned a gender probability to each author based on their given name and assigned a country based on the paper author's affiliation or affiliations listed in their paper.

The results were surprising, said Liu.

Overall output in astronomy, measured by the annual paper count, had increased. 

"While one may assume that COVID has mostly negative impacts on the world, this positive phenomenon may not be hard to understand: COVID-induced changes such as increased flexibility in work arrangement, reduced commutes and business trips, as well as improved virtual technologies, among others, are potentially favorable for conducting scientific research," said Liu.

However, when the researchers looked into whether the positive outcome was result of more researchers entering the field, or an increase in individual productivity, they found the latter was mainly responsible for the trend.

"When we counted the average number of papers each researcher produced, we saw boosted individual productivity seen across most countries. Meanwhile, a decreasing number of incoming new researchers is seen in most of the countries we studied. This result indicates larger barriers for new researchers to enter the field, or for junior researchers to complete their very first project during COVID," said Liu.

Finally, the researchers found the productivity of female astronomers was worst affected. Fourteen out of 25 countries studied saw a smaller fraction of papers written by women, and fewer women researchers entering the astronomy field. During COVID-19 so far, no female researchers were able to be more productive than their male colleagues, even in countries including the Netherlands, Australia, and Switzerland, where female researchers had been as productive as male colleagues before the pandemic.

The researchers say their data only studies trends over a limited period of time as the pandemic still continues. While they were able to study quantitative outputs during the pandemic, the quality of these papers is yet to be studied. 

Details of this study were published in Nature Astronomy on 28 November.

IAU CPS Statement on BlueWalker 3

Global astronomy community troubled by unprecedented brightness and use of terrestrial frequencies from space of recently launched BlueWalker 3 satellite

Business Announcement

INTERNATIONAL ASTRONOMICAL UNION

Trail left by BlueWalker 3 over Kitt Peak National Observatory 

IMAGE: TRAILS IN THE NIGHT SKY LEFT BY BLUEWALKER 3 ARE JUXTAPOSED AGAINST THE NICHOLAS U. MAYALL 4-METER TELESCOPE AT KITT PEAK NATIONAL OBSERVATORY IN ARIZONA, A PROGRAM OF NSF'S NOIRLAB. THE BREAKS IN THE TRAIL ARE CAUSED BY BREAKS BETWEEN FOUR TWENTY SECOND EXPOSURES THAT WERE STACKED TO CREATE THIS IMAGE. view more 

CREDIT: KPNO/NOIRLAB/IAU/SKAO/NSF/AURA/R. SPARKS

The International Astronomical Union Center for the Protection of the Dark and Quiet Sky from Satellite Constellation Interference expresses concern about the recently launched prototype BlueWalker 3 satellite’s impact on astronomy. New measurements reveal that this low Earth orbiting satellite is now one of the brightest objects in the night sky, outshining all but the brightest stars. In addition, the satellite’s use of terrestrial radio frequencies poses a new challenge to radio astronomy.

On 10 September 2022 AST SpaceMobile (https://ast-science.com/) launched a prototype satellite called BlueWalker 3 into low Earth orbit. This satellite, which has a 64-square-meter (693-square-foot) antenna system (the largest commercial antenna system ever deployed into low Earth orbit), is the first of what is expected to be more than a hundred similar or even larger satellites.

New measurements by observers worldwide, coordinated by the International Astronomical Union’s CPS (http://cps.iau.org) (IAU Center for the Protection of the Dark and Quiet Sky from Satellite Constellation Interference), show that this satellite has become one of the brightest objects in the night sky — more so than other constellation satellites and at times as bright as some of the most recognizable stars [1].

Besides their visible brightness, these new satellites, which serve as “cell phone towers in space,” will transmit strong radio waves at frequencies currently reserved for terrestrial cell-phone communications. These orbiting transmitters, which are not subject to the same radio quiet zone (https://en.wikipedia.org/wiki/Radio_quiet_zone restrictions) [2] as ground-based cellular networks, have the potential to severely impact radio astronomy research as well as geodesy studies and space-physics experiments.

The IAU and its CPS co-hosts, NSF's NOIRLab (https://noirlab.edu/public/) and the SKA Observatory (https://www.skao.int/en) (SKAO), are concerned about the impact these satellites will have on fundamental research and humanity’s ability to experience the natural night sky.

“Astronomers build radio telescopes as far away as possible from human activity, looking for places on the planet where there is limited or no cell phone coverage. Frequencies allocated to cell phones are already challenging to observe even in radio quiet zones we have created for our facilities. New satellites such as BlueWalker 3 have the potential to worsen this situation and compromise our ability to do science if not properly mitigated,” said SKAO Director-General Philip Diamond. “This is a key reason why the SKAO is deeply involved in the IAU CPS and promoting the equitable and sustainable use of space.”

The night sky is a unique laboratory that allows scientists to conduct experiments that cannot be done in terrestrial laboratories. Astronomical observations have provided insights into fundamental physics and other research at the boundaries of our knowledge and changed humanity’s view of our place in the cosmos. The pristine night sky is also an important part of humanity’s shared cultural heritage and should be protected for society at large and for future generations.

“BlueWalker 3 is a big shift in the constellation satellite issue and should give us all reason to pause,” said Piero Benvenuti, Director of the IAU CPS.

The IAU and CPS partners recognize that the new satellite constellations have an important role in improving worldwide communications. However, their interference with astronomical observations could severely hamper progress in our understanding of the cosmos. Their deployment should therefore be conducted with due consideration of their side effects and with efforts made to minimize their impact on astronomy.

To better understand the effects of these new satellites, the IAU CPS invites further observations of BlueWalker 3. Visual and telescopic (https://trailblazer.dirac.dev/) observations of BlueWalker 3 can be submitted online (https://forms.gle/aEyrADs5CAR7WFUw8) to SatHub, a worldwide public observing initiative of the IAU CPS.

The IAU recently wrote a letter (https://www.iau.org/news/announcements/detail/ann22039/) on behalf of the global astronomy community to the U.S. Federal Communications Commission (FCC - https://www.fcc.gov/) urging them to seriously consider the potential impacts of satellite constellations on astronomy, the appearance of the night sky, and the environment. Earlier this month, the FCC announced its intention to create an office dedicated to space, to better deal with this rapidly emerging issue, an action that the IAU CPS applauds.

Conversations between the IAU CPS and AST SpaceMobile are being planned. The IAU CPS fosters dialogue and cooperation between satellite operators and scientists. Recent discussions with some operators have led to mitigation measures but much more work is needed.

Notes

[1] The measurements show that BlueWalker 3 is around apparent visual magnitude 1 at its brightest — almost as bright as Antares or Spica (the 15th and 16th brightest stars in the night sky). Apparent magnitude in astronomy is a measure of the brightness of a star or other astronomical object as observed from Earth. The scale is reverse logarithmic: the brighter an object is, the lower its magnitude number. The brightest astronomical objects have negative apparent magnitudes: for example, Venus at −4.2 or Sirius at −1.46. The faintest stars visible with the naked eye on the darkest night have apparent magnitudes of about +6.5.

[2] There are several areas around the globe that have special protections for radio astronomy that prescribe how fixed radio transmitters can be used so they do not interfere with astronomical observations. The United States National Radio Quiet Zone (https://info.nrao.edu/do/spectrum-management/national-radio-quiet-zone-nrqz-1) is a 13,000 square mile (34,000 square kilometer) region in which broadcast antennas must operate at reduced power and use highly directional antennas.

More information

The IAU is the international astronomical organization that brings together more than 12 000 active professional astronomers from more than 100 countries worldwide. Its mission is to promote and safeguard astronomy in all its aspects, including research, communication, education and development, through international cooperation. The IAU also serves as the internationally recognised authority for assigning designations to celestial bodies and the surface features on them. Founded in 1919, the IAU is the world's largest professional body for astronomers.

Links

* CPS website - https://cps.iau.org/

Contacts

Siegfried Eggl
Co-Lead, Sathub, University of Illinois
Email: eggl@illinois.edu

Mike Peel
Co-Lead, Sathub, Instituto de Astrofísica de Canarias
Email: mpeel@iac.es

Piero Benvenuti
Director of the IAU Centre for the Protection of the Dark and Quiet Sky from Satellite Constellation Interference
Email: piero.benvenuti@cps.iau.org

Constance E. Walker
NSF’s NOIRLab
Co-Director of the IAU Center for the Protection of Dark and Quiet Sky from Satellite Constellation Interference
Email: connie.walker@noirlab.edu

Federico Di Vruno
Co-Director of the IAU Centre for the Protection of the Dark and Quiet Sky from Satellite
Constellation Interference, SKAO
Email: federico.divruno@cps.iau.org

Lars Lindberg Christensen
IAU Director of Communications
Tel: +1 520 461 0433
Cell: +49 173 38 72 621
Email: lars.christensen@noirlab.edu


LIKE CHIPPED TOAST

Novel method automates the growth of brain tissue organoids on a chip

The new system can increase reproducibility in cerebral organoid research and shows promise for lowering levels of cellular stress

Peer-Reviewed Publication

UNIVERSITY OF CALIFORNIA - SANTA CRUZ

Organoids figure 

IMAGE: TWELVE INDIVIDUAL 12-DAY-OLD CEREBRAL CORTEX CULTURES AT DAY 1 OF AUTOMATED FEEDING. view more 

CREDIT: SPENCER SEILER

A team of engineers at UC Santa Cruz has developed a new method for remote automation of the growth of cerebral organoids – miniature, three-dimensional models of brain tissue grown from stem cells. Cerebral organoids allow researchers to study and engineer key functions of the human brain with a level of accuracy not possible with other models. This has implications for understanding brain development and the effects of pharmaceutical drugs for treating cancer or other diseases.

In a new study published in the journal Nature Scientific Reports, researchers from the UCSC Braingeneers group detail their automated, internet-connected microfluidics system, called “Autoculture.” The system precisely delivers feeding liquid to individual cerebral organoids in order to optimize their growth without the need for human interference with the tissue culture.

Cerebral organoids require a high level of expertise and consistency to maintain the precise conditions for cell growth over weeks or months. Using an automated system, as demonstrated in this study, can eliminate disturbance to cell culture growth caused by human interference or error, provide more robust results, and allow more scientists access to opportunities to conduct research with human brain models. 

Autoculture also addresses variation that arises in organoid growth due to “batch effect” issues, where organoids grown at different times or at different labs under similar conditions may vary just because of the complexity of their growth. Using this uniform, automated system can reduce variation and allow researchers to better compare and validate their results. 

“One of the big challenges is that these cultures are not very reproducible, and in part it's not surprising because these are months-long experiments. You have to change media every couple of days and try to treat these cultures uniformly, which is extremely challenging,” said Sofie Salama, an acting professor of molecular, cellular and developmental biology at UCSC and an author on the study. 

Unique design

Autoculture uses a microfluidic chip designed by the researchers, spearheaded by Associate Professor of Electrical and Computer Engineering Mircea Teodorescu and Biomolecular Engineering Ph.D. student Spencer Seiler. Their novel chips, created from a unique bi-layer mold, have tiny wells and channels for delivering minute amounts of liquid to the organoid, which allow the scientists to have a high level of control over nutrient concentrations and byproducts. Overall, the system uses mostly off-the-shelf, low-cost components, making it accessible and modular. 

“A novel and important feature of this machine is that on one hand, it streamlines the process and makes sure that everything is very consistent,” Teodorescu said. “On the other hand, it's very modular because the system is controlled by the computer, so there are different parts of the chip that are interchangeable and have their own advantages – it's very much a modern agent.”

Because the system delivers a non-stop flow of liquid to the organoids, it more closely resembles the real conditions of the brain, which is constantly fed nutrients through the blood.  

Unlike other methods for organoid growth which grow the cultures together in one dish, the Autoculture system contains a culture plate with 24 individual wells, so each well can be its own experiment in which cultures can be grown independently and fed liquids at varying, programmable concentrations and times. An in-incubator imaging system lets the researchers constantly remotely monitor organoid growth and morphology.  

“The prize of the system is that every organoid has its own, personal micro-environment for which fluid flows in and out of,” Seiler said. “Now we’ve separated them – this would be too laborious to do by hand, but it's fine for a machine.” 

Additionally, a unique feature of the system is that feeding media for each individual culture can be pulled out for analysis at any point during an experiment. This allows researchers to non-invasively measure data such as pH and glucose levels which can be important for monitoring cell growth.  

The microfluidics system is connected to the internet to allow scientists to remotely operate and retrieve real-time data from the system at any point, without disrupting the culture. Another paper from the Braingeneers group, published in the journal Internet of Things, shows how the Autoculture system is one example of the power of extending the internet-of-things to enable remote-controlled experiments – a need which the pandemic made more urgent.

When measuring their cerebral organoids, the researchers found that the stem cells grown using the Autoculture system not only differentiated into various cell types normally, but actually looked healthier than those grown using standard methods. RNA sequencing found lower levels of glycolytic and endoplasmic reticulum stress, showing a first promising set of data for addressing cellular stress identified in a Nature paper by collaborating researchers at UCSF, evidence that the group plans to expand on in ongoing research.

This research provides an important platform for the ongoing work within the UCSC Live Cell Genomics Center. It is aligned with the center’s mission to apply lessons from the computer revolution to life sciences and is part of a larger drive toward automation of wet labs to make experiments more robust and reproducible.

VAGINA ON A CHIP

A breakthrough in bacterial vaginosis treatment for women’s health

Human Organ Chip allows researchers to study effects of microbiome on vaginal health

Peer-Reviewed Publication

WYSS INSTITUTE FOR BIOLOGICALLY INSPIRED ENGINEERING AT HARVARD

The human microbiome has been a hot topic over the last decade, with research pointing to disrupted bacterial communities as culprits for a host of maladies including irritable bowel syndrome, eczema, and autoimmune diseases. Most studies have focused on the microbiome within the human gut, but there is growing recognition that another oft-ignored bacterial community deserves equal attention - that found in the vagina.

Vaginal microbiome disruptions cause bacterial vaginosis (BV), which afflicts nearly 30% of reproductive-aged women around the globe and costs an estimated $4.8 billion to treat annually. BV doubles the risk of many sexually transmitted infections including HIV and increases the risk of pre-term birth in pregnant women, which is the second-leading cause of death in newborns. BV is currently treated with antibiotics, but it often recurs and can lead to more severe complications including pelvic inflammatory disease and even infertility.

Just as probiotics are now being prescribed to treat gut issues, living biotherapeutics are being explored for the treatment of BV. However, it is difficult to conduct preclinical trials because the human vaginal microbiome is dramatically different from that of common animal models. Studies have found that Lactobacilli bacteria comprise more than 70% of the healthy human vaginal microbiome, but less than 1% of the vaginal microbiome in other mammals.

Researchers at the Wyss Institute at Harvard University have created a solution to that problem in the form of a new Organ Chip that replicates the human vaginal tissue microenvironment including its microbiome in vitro. Composed of human vaginal epithelium and underlying connective tissue cells, the Vagina Chip replicates many of the physiological features of the vagina and can be inoculated with different strains of bacteria to study their effects on the organ’s health. The chip is described in a new paper published in Microbiome.

Modeling the vaginal microbiome

The Vagina Chip was developed with funding from the Bill and Melinda Gates Foundation, which aimed to create a biotherapeutic treatment for BV and move it into human clinical trials to decrease infections of the reproductive tract, prenatal complications, and infant death rates. particularly in low-resource nations.

“A major stumbling block for that effort was that there were no good preclinical models that could be used to study which therapies can actually treat BV in human tissues. Our team’s project was to create a human Vagina Chip to aid in the development and testing of new therapies for BV,” said co-author Aakanksha Gulati, Ph.D., a Postdoctoral Researcher at the Wyss Institute

Using the microfluidic Organ Chip platform developed at the Wyss Institute and subsequently licensed to Emulate, the team seeded the top channel of a polymer chip with human vaginal epithelial cells. They then added human uterine fibroblast cells to the opposite side of the permeable membrane separating the top and bottom channels. This 3D arrangement replicated the structure of the human vaginal wall.

After five days, the Vagina Chip had developed multiple distinct layers of differentiated cells that matched those found in human vaginal tissue. When the scientists introduced the female sex hormone estradiol (a form of estrogen) into the Vagina Chip, the chips’ gene expression patterns changed in response, indicating that it was sensitive to hormones - another critical feature for replicating human reproductive organs in vitro.

Armed with a living model of the human vagina, the team then moved to study the vaginal microbiome. Recent research has shown that healthy human vaginal microbiomes typically contain multiple strains of Lactobacillus bacteria, so they worked with Dr. Jacques Ravel, Ph.D. and his team at University of Maryland School of Medicine, who had created three different consortia each containing several strains of L. crispatus. When they introduced these consortia into the Vagina Chip, all three successfully colonized the chips after three days. The consortia also began producing lactic acid, which helps to maintain the vagina’s low pH and inhibits the growth of other microbes.

Beyond helping to maintain an acidic environment, the presence of the L. crispatus bacteria also affected the Vagina Chip’s innate immune responses. Chips with bacterial consortia produced lower levels of several inflammation-causing cytokine molecules than chips without the bacteria, which is consistent with the current theory that these “good” microbes help keep inflammation in check in healthy human vaginas.

Bad bacterial tenants, on a chip

Having created a healthy Vagina Chip with optimal bacterial residents, the team then conducted a new experiment in which they inoculated chips with different species of bacteria that are associated with BV: Gardnerella vaginalisPrevotella bivia, and Atopobium vaginae. A consortium of those three “bad” microbes caused the chips’ pH to increase, damaging the vaginal epithelial cells and significantly increasing the production of multiple proinflammatory cytokines - all responses that were similar to what has been observed in human patients with BV.

“It was very striking that the different microbial species produced such opposite effects on the human vaginal cells, and we were able to observe and measure those effects quite easily using our Vagina Chip,” said co-author Abidemi Junaid, Ph.D., a Research Scientist at the Wyss Institute. “The success of these studies demonstrate that this model can be used to test different combinations of microbes to help identify the best probiotic treatments for BV and other conditions.”

The team is now using the Vagina Chip to test new and existing treatments for BV to identify effective therapies that can be advanced into clinical trials. They are also working on integrating immune cells into the chip to study how the vaginal microbiome might drive systemic immune system responses.

“There is growing recognition that taking care of women’s health is critical for the health of all humans, but the creation of tools to study human female physiology is lagging,” said senior author Don Ingber, M.D., Ph.D., who is the Wyss Institute’s Founding Director. “We’re hopeful that this new preclinical model will drive the development of new treatments for BV as well as new insight into female reproductive health.” Ingber is also the Judah Folkman Professor of Vascular Biology at Harvard Medical School and Boston Children’s Hospital and the Hansjörg Wyss Professor of Bioinspired Engineering at the Harvard John A. Paulson School of Engineering and Applied Sciences.

Additional authors of the paper include Tania To, Nina LoGrande, Zohreh Izadifar, Sanjay Timilsina, Viktor Horvath, and Girija Goyal from the Wyss Institute; former Wyss Institute members Erin Doherty, Arlene Sutherland, Jennifer Grant, Roberto Plebani, Rachelle Prantil-Baun, and first author Gautam Mahajan; Michael France and Jacques Ravel from the University of Maryland School of Medicine; Indriati Hood-Pishchany and Seth Rakoff-Nahoum from Boston Children’s Hospital and Harvard Medical School; and Douglas Kwon from Massachusetts General Hospital.

This work was supported by the Bill and Melinda Gates Foundation and the Wyss Institute for Biologically Inspired Engineering at Harvard University.

New programming tool turns sketches, handwriting into code

Reports and Proceedings

CORNELL UNIVERSITY

ITHACA, N.Y. – Cornell University researchers have created an interface that allows users to handwrite and sketch within computer code – a challenge to conventional coding, which typically relies on typing.

The pen-based interface, called Notate, lets users of computational, digital notebooks open drawing canvases and handwrite diagrams within lines of traditional, digitized computer code.

Powered by a deep learning model, the interface bridges handwritten and textual programming contexts: notation in the handwritten diagram can reference textual code and vice versa. For instance, Notate recognizes handwritten programming symbols, like “n”, and then links them up to their typewritten equivalents.

“A system like this would be great for data science, specifically with sketching plots and charts that then inter-operate with textual code,” said Ian Arawjo, lead author of the paper and doctoral student in the field of information science. “Our work shows that the current infrastructure of programming is actually holding us back. People are ready for this type of feature, but developers of interfaces for typing code need to take note of this and support images and graphical interfaces inside code.”

Arawjo also said the work demonstrates a new path forward by introducing artificial intelligence-powered, pen-based coding at a time when drawing tablets are becoming more widely used.

“Tools like Notate are important because they open us up to new ways to think about what programming is, and how different tools and representational practices can change that perspective,” said Tapan Parikh, associate professor of information science and paper co-author.

The tool was described in “Notational Programming for Notebook Environments: A Case Study with Quantum Circuits”.

For additional information, see this Cornell Chronicle story.

Cornell University has dedicated television and audio studios available for media interviews.

-30-

Physicist identifies how electron crystals melt

Peer-Reviewed Publication

CORNELL UNIVERSITY

ITHACA, N.Y. -- The mysterious changes in phases of matter – from solid to liquid and back again – have fascinated Eun-Ah Kim since she was in lower elementary school in South Korea. Without cold drinking water readily available, on hot days the children would bring bottles of frozen water to school.

Kim noticed that when the water melted, the volume changed.

“That revealed to me there is something in there that I cannot see with my eyes,” said Kim, professor of physics in the College of Arts and Sciences. “Matter around me is made up of invisible entities that interact and do something together to change their state.”

Kim’s fascination with melting continues, but she now studies transitions in more exotic materials than water: electron crystals. In a new paper, Kim and first author Michael Matty, M.S. ’19, Ph.D. ’22, have described a phase in between the liquid and the solid for these electron structures – a liquid crystal state.

Their paper, “Melting of Generalized Wigner Crystals in Transition Metal Dichalcogenide Heterobilayer Moiré Systems,” published Nov. 19 in Nature Communications.

Because electrons are all negatively charged, they repel each other; thus their preferred state is to be as far as possible from every other electron in the material that contains them. The regular arrangement of electrons that results from this equal repulsion in all directions is called a Wigner crystal.

Kim and Matty wanted to know how the electrons transition from one regular arrangement as a crystal to another regular arrangement as a crystal, or how they “melt.”

To find the answer, the researchers studied how electrons interact on an artificial grid, called a moiré lattice, formed by placing two distinct atomically thin materials on top of each other. Because they are on a grid rather than a smooth surface, the electrons can’t choose arbitrary locations away from each other, but must fill a point on the grid; the grid constrains how they are arranged.

“When the grid is partially filled, we get to see the impact of their repulsion and how strongly the electrons are interacting with each other,” Kim said. “As a result of their interaction, we see that they occupy a regular interval of sites on the lattice, not random intervals.”

The particular moiré lattice the researchers considered for their study was developed by Cornell experimentalists Kin Fai Mak, professor of physics (A&S) and associate professor of physics in Cornell Engineering, and Jie Shan, professor of physics (A&S) and applied and engineering physics (Engineering).

“Cornell experimentalists are at the frontier of artificial moiré material research,” Kim said, “doing these amazing experiments with an astonishing degree of control, offering opportunities for theoretical ideas to manifest in physical systems.”

Shan and Mak had experimentally detected particular rigid structures that the electrons formed in partially filled grids. Kim and Matty studied how one of these structures would transition to another. They found that when conditions were changed, that very regular, rigid array becomes more fluid.

The researchers identified an intermediate phase between solid and liquid in electrons that has some regularity but not as much as a solid, and not as much freedom as a liquid. They found that the electrons in this state arrange themselves into tiny strips that can move around and orient themselves in structures.

“Electronic liquid crystals had been discussed theoretically, but we’re providing a visual image of how they can form microscopically: four or five electrons forming a piece that can be arranged,” said Kim. “What we’ve accomplished is a microscopic understanding of what was only known in principle to be possible.”

The work was supported by the National Science Foundation.

-30-

Organizing nanoparticles into pinwheel shapes offers new twist on engineered materials

Peer-Reviewed Publication

UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN, NEWS BUREAU

Jiahui Li, left, Shan Zhou and professor Qian Chen show off an electron micrograph image of their new pinwheel lattice structure developed to help engineers build new materials with unique optical, magnetic, electronic and catalytic properties. 

IMAGE: JIAHUI LI, LEFT, SHAN ZHOU AND PROFESSOR QIAN CHEN SHOW OFF AN ELECTRON MICROGRAPH IMAGE OF THEIR NEW PINWHEEL LATTICE STRUCTURE DEVELOPED TO HELP ENGINEERS BUILD NEW MATERIALS WITH UNIQUE OPTICAL, MAGNETIC, ELECTRONIC AND CATALYTIC PROPERTIES. view more 

CREDIT: PHOTO BY FRED ZWICKY

CHAMPAIGN, Ill. —Researchers have developed a new strategy to help build materials with unique optical, magnetic, electronic and catalytic properties. These pinwheel-shaped structures self-assemble from nanoparticles and exhibit a characteristic called chirality – one of nature’s strategies to build complexity into structures at all scales, from molecules to galaxies.  

Nature is rich with examples of chirality – DNA, organic molecules and even human hands. In general, chirality can be seen in objects that can have more than one spatial arrangement. For example, chirality in molecules might present itself as two strings of atoms that have the same composition, but each having a “twist” to the left or right in their spatial orientations, the researchers said.

The new study, led by Qian Chen, a professor of materials science and engineering at the University of Illinois Urbana-Champaign, and Nicholas A. Kotov, a professor chemical engineering at the University of Michigan, extends chirality into lattices assembled from nanoparticle building blocks to create new metamaterials – materials designed to interact with their surroundings to perform specific functions.

The study is published in the journal Nature.

Efforts to make large-scale chiral lattices from spontaneous assembly of nanoparticles have been met with limited success. Chen said previous studies relied on templates that produced very small structures, limiting their usefulness in metamaterials design.

“In the new study, we were inspired by the symmetry-breaking characteristics of porous materials to assemble reconfigurable lattices from pyramid-shaped nanoparticles smaller than 100 nanometers,” said former Illinois postdoctoral researcher Shan Zhou, the lead author of the work and currently a professor at South Dakota School of Mines and Technology. “The resulting lattice is large enough to be seen with the naked eye.”

Chen said previous models had not predicted a pinwheel lattice with chirality.

In this study, predictions based on graph theory and calculations developed by Kotov and Michigan postdoctoral researchers Ju Lu and Ji-Young Kim predicted – to their surprise – that the pinwheel lattice structure, although achiral in nature, becomes chiral on a substrate.

“The new lattice structure is fascinating from a research perspective, as it invites many new multifaceted study opportunities of their properties,” Kotov said.

Chen’s liquid-phase electron microscopy technique – which she says is akin to a “tiny aquarium for observing nanoparticle self-assembly” – was instrumental to this study.

Making this structure did not come by luck, though, the researchers said.

“The quantitative models turned out to be well-matched with the dynamic assembly process observed in the nanoaquarium of the liquid-phase electron microscope,” said Jiahui Li, an Illinois graduate student and co-author of the study.

“The liquid-phase electron microscopy allowed us to take the superlattice assembly even further,” Chen said.

“Because we can observe and manipulate the nanoparticle interactions in real time, we can precisely tune their motions to form the very intricate design of the pinwheel,” Li said.

In addition to liquid-phase electron microscopic techniques, the ultrafast electron microscope at the U.S. Department of Energy’s Argonne National Laboratory provided a unique understanding of the self-assembled superlattices’ optical properties at the nanometer scale.

“No one has been able to directly see the chiral responses of objects at such a small length using other techniques,” said Haihua Liu, a researcher at Argonne’s Center for Nanoscale Materials.

The team foresees this imaging platform being used to characterize a wide range of nanoparticles and self-assembled structures.

“As a theorist working in all things nanoparticle, I have always been interested in how to assemble nanoparticle arrangements that are chiral,” said Alex Travesset, a professor at Iowa State University who performed the geometric calculations for the pinwheel lattice. “The interesting behaviors of pinwheel lattice can go beyond their chiroptical responses.”

Kai Sun, a Michigan professor and study co-author, said the pinwheel lattices can reconfigure their structures, a property that is potentially useful in the design of combat helmets and airplanes, for example.

The researchers also envision using this new strategy to make other chiral metacoatings based on the existing library of synthetically available nanoparticles, and that it will enable a rich design space of metastructured surfaces with chiroptical activity and mechanical properties.

“We feel that this substrate-supported chiral assembly method can benefit the whole nanomaterials research community,” Kotov said.

Chen also is affiliated with the Materials Research Laboratorychemistrychemical and biomolecular engineering, the Carl R. Woese Institute for Genomic Biology and the Beckman Institute for Advanced Science and Technology at the U. of I.

The Office of Naval Research support this research through a Multidisciplinary University Research Initiative.

Editor’s notes:

To reach Qian Chen, call 217-300-1137; email qchen20@illinois.edu

The paper “Chiral assemblies of pinwheel superlattices on substrates” is available online and from the U. of I. News Bureau. DOI: 10.1038/s41586-022-05384-8.

 

COVID lockdown did not lead to a rush on opioid prescriptions

Peer-Reviewed Publication

COLUMBIA UNIVERSITY'S MAILMAN SCHOOL OF PUBLIC HEALTH


While some feared that New Yorkers would re-fill prescriptions to stockpile opioid medications in the early weeks of the COVID-19 lockdown much in the way people hoarded toilet paper, in fact, New York State opioid prescriptions declined in the period around the March 20, 2020 “PAUSE” order, according to new research. Meanwhile, prescriptions for medications for opioid use disorder (MOUD) were steady, likely thanks to policies to ensure their availability during the same period.

The study was led by researchers at Columbia University Mailman School of Public Health and appears in the journal Addiction, the journal of the Society for the Study of Addiction.

The researchers used a database from the health information technology and clinical research company IQVIA to examine trends in the dispensing of opioid prescriptions as New York State implemented various emergency policies to prevent the spread of COVID-19. These orders included pharmacy guidance permitting early refills of controlled and non-controlled medications (March 7); a suspension of elective surgeries in New York City (March 16); and a “New York State on PAUSE” order that greatly reduced trips outside the home (March 20). A concern with the recommendation for patients to refill their prescriptions early was that it would increase the quantities of opioids in households and increase the risk of opioid misuse and overdose. During the same period, the Substance Abuse and Mental Health Services Administration initiated a series of policy responses to support access to MOUD, such as expanding telemedicine and allowing online prescribing of buprenorphine.

They found that prescriptions for non-MOUD opioids steadily declined between the weeks of March 21 and April 17 with only a small transient increase in early refills. The morphine milligram equivalents/day (MME/day) prescribed were 17 percent lower than in the four weeks before March 21—almost entirely due to a drop in opioids dispensed for prescriptions of a week or less, suggesting the driving cause was the suspension of elective surgeries. (Another possible explanation is reduced demand for opioids related to a decline in accidents and injuries during the lockdown period.) There was no discernable drop in MOUD dispensing associated with the period of the Emergency Orders with only a slight increase in the count of dispensed prescriptions in the week of March 14. These trends were evident statewide, with no disparities between ZIP codes with higher or lower poverty rates.

The findings are in line with an earlier study that found the lockdown Texas similarly did not lead to a spike in prescriptions for non-MOUD opioids.

“Our findings add to the evidence showing that the pandemic emergency orders did not cause a mass surge in dispensing of opioids and policy initiatives to ensure access to medications for opioid use disorder were likely effective,” says Andrew Rundle, DrPH, professor of epidemiology at Columbia University Mailman School of Public Health. “The research suggests that critical access to treatments for opioid use disorder can be maintained during future emergency ‘stay at home’ type orders and such orders are unlikely to cause mass early refills of opioid prescriptions and heightened risk of misuse.”

The study’s first author is Abhinav Suri, who conducted the research as an MPH student in epidemiology at Columbia Mailman School and is now a medical student at the David Geffen School of Medicine, UCLA. Additional authors include Daniel J. Feaster and Raymond R. Balise, University of Miami Miller School of Medicine; Edward V. Nunes, Columbia University Irving Medical Center; Louisa Gilbert and Nabila El-Bassel, Columbia University School of Social Work.

This research was supported by the National Institutes of Health through the NIH HEAL Initiative (UM1DA049412).  Access to IQVIA data was provided as part of the IQVIA Institute’s Human Data Science Research Collaborative in support of research activities related to important health system issues arising in the era of COVID-19.