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A photo of Dr. Steven Jonas, Jason Belling and Paul Weiss of UCLA .

A step toward a more efficient way to make gene therapies to attack cancer, genetic disorders

A photo of Dr. Steven Jonas, Jason Belling and Paul Weiss of UCLA .

(From left) Dr. Steven Jonas, Jason Belling and Paul Weiss of UCLA (Photo Credit: Reed Hutchinson)

A UCLA-led research team today reports that it has developed a new method for delivering DNA into stem cells and immune cells safely, rapidly and economically. The method, described in the journal Proceedings of the National Academy of Sciences, could give scientists a new tool for manufacturing gene therapies for people with cancer, genetic disorders and blood diseases.

The study’s co-senior author is Paul Weiss, a UCLA distinguished professor of chemistry and biochemistry, of bioengineering and of materials science and engineering. “We are figuring out how to get gene-editing tools into cells efficiently, safely and economically,” he said. “We want to get them into enormous numbers of cells without using viruses, electroshock treatments or chemicals that will rip open the membrane and kill many of the cells, and our results so far are promising.”

In current practice, cells used for genetic therapies are sent to specialized labs, which can take up to two months to produce an individualized treatment. And those treatments are expensive: A single regimen for one patient can cost hundreds of thousands of dollars.

“We hope our method could be used in the future to prepare treatments that can be performed at the patient’s bedside,” Weiss said.

The method could be used with CRISPR, the genetic engineering technique that enables DNA to be edited with remarkable precision. However, using CRISPR efficiently, safely and economically in medical therapies has proven to be a challenge — one this new method may be able to solve.

The technique uses high-frequency acoustic waves coupled with millions of cells that flow through an “acoustofluidic device” in a cell culture liquid. The device was invented by the research team as part of the study; inside of it are tiny speakers that convert electrical signals to mechanical vibrations that are used to manipulate the cells.

That procedure opens up pores along the cells’ membranes that allow DNA and other biological cargo to enter the cells, and it enables the researchers to insert the cargo without the risk of damaging the cells by contacting them directly.

Dr. Steven Jonas, the study’s co-senior author and a UCLA clinical instructor in pediatrics, likened the soundwaves’ ability to move cells to the experience when audience members actually feel the sound at a concert.

“At a concert hall, you can feel the bass — and if you can feel the sound, the cell can feel the acoustic wave,” said Jonas, a member of the California NanoSystems Institute at UCLA, the UCLA Jonsson Comprehensive Cancer Center and Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research at UCLA. “We can engineer the acoustic waves to direct the cells as needed.”

The researchers delivered short strands of DNA called plasmids into human blood cells and blood-forming stem cells that were intended specifically for laboratory research, and pumped millions of such cells through the acoustofluidic device. Once inside a cell, a plasmid can be made into a protein that may be missing or damaged, or it can give the cell new capabilities.

“When combined with new gene-editing approaches, the method enables us to correct a DNA sequence that is miscoded in a disease,” said Weiss, who also is a member of CNSI.

Plasmids used as templates for gene editing can make the correction because they have the right coded sequence for the desired protein, he explained.

Lead author Jason Belling, a UCLA graduate student in chemistry and biochemistry, was able to insert plasmids into the model cells used for testing about 60% of the time, without using any chemical and physical treatments.

“The viability is very high compared with other techniques,” Weiss said, “but we still want higher efficiencies and are working toward that.”

Jonas — whose expertise is in treating childhood cancer and blood disorders — said the research has the potential to benefit adults and children with cancer, immune system disorders and genetic diseases.

“If the delivery works, and it seems to, this research is an important step toward bringing new therapies more broadly to the patients who need them,” Jonas said. “Traditionally, we have treated cancers with chemotherapy, surgery, radiation and bone marrow transplantations. Now, we’re at an amazing era of medicine, where we can use different types of gene therapies that can train the immune system to fight cancer.”

A photo of a prototype of the acoustofluidic device developed by UCLA researchers.

A prototype of the acoustofluidic device developed by UCLA researchers. (Photo Credit: Reed Hutchinson)

Jonas said some existing treatments can take a patient’s T cells and adapt them with a gene that encodes for a receptor that allows it to target the cancer.

“We want to be the delivery service that gets these therapeutic packages to the cells,” he said. “I want to treat my patients with cells that are engineered in this way.”

For the technique to lead to viable treatments for disease, it would need to allow doctors  to process at least a couple hundred million cells — and in some cases, billions of cells — safely, rapidly and cost-effectively for each patient.

The new approach is still the subject of research and is not available to treat human patients.

The study’s other co-authors include Duke University professor Tony Huang, a pioneer of acoustofluidics and a UCLA alumnus; Dr. Stephen Young, distinguished professor of medicine and human genetics at the David Geffen School of Medicine at UCLA; and Dr. Satiro De Oliveira, a UCLA assistant professor of pediatrics.

The study was funded in part through a National Institutes of Health Director’s Early Independence Award for Jonas; the University of California Center for Accelerated Innovation; and Belling’s predoctoral fellowship through the National Heart, Lung, and Blood Institute. Jonas also has received young investigator awards from the Alex’s Lemonade Stand Foundation for Childhood Cancer Research, Hyundai Hope on Wheels Foundation for Pediatric Cancer Research, and the Tower Cancer Research Foundation. UCLA’s Technology Development Group Innovation Fund also provided funding.

Weiss’ research group has applied for patents on the acoustofluidic device and related devices, working with the Technology Development Group.

This article originally appeared in the UCLA Newsroom.

Keeping Our First Responders in LA County Hospitals Safe

A photo of a first responder receives safety glasses and goggles.

A first responder receives safety glasses and goggles. (Photo Courtesy of UCLA Department of Chemistry and Biochemistry)

The Department of Chemistry and Biochemistry, spurred on by Professor Neil Garg, donated hundreds of safety glasses and goggles to help keep first responders in Los Angeles County hospitals safe. The distribution, orchestrated in a single weekend, was a way to express thanks to the selfless medical personnel in Los Angeles.

This post originally appeared on the Department of Chemistry and Biochemistry’s Facebook.

A photo of Lynn Vavreck and Miguel García-Garibay.

Two elected to American Academy of Arts and Sciences

A photo of Lynn Vavreck and Miguel García-Garibay.

From left: Lynn Vavreck, Miguel García-Garibay

Six exceptional UCLA professors and leaders — including the UCLA College’s Physical Sciences Dean Miguel García-Garibay and Political Science Professor Lynn Vavreck — were elected April 23 to the American Academy of Arts and Sciences, one of the nation’s most prestigious honorary societies. The other honorees include School of Law Dean Jennifer Mnookin, Education Professor Pedro Noguera, environmental champion Mary Nichols and Hammer Museum Director Ann Philbin.

“I am delighted to congratulate each of this year’s UCLA inductees, who are all deserving of this wonderful honor,” UCLA Chancellor Gene Block said. “Election to the American Academy of Arts and Sciences is a testament to the exceptional work of our scholars and leaders. The entire campus community can take pride in this news and their many accomplishments.”

A total of 276 artists, scholars, scientists and leaders in the public, nonprofit and private sectors who were elected to the Academy today. More about UCLA’s honorees:

Miguel García-Garibay, dean of the UCLA Division of Physical Sciences and professor of chemistry and biochemistry, has earned worldwide recognition in the fields of artificial molecular machines, organic photochemistry, solid-state organic chemistry and physical organic chemistry. He studies the interaction of light and molecules in crystals. Light can have enough energy to break and make bonds in molecules, and García-Garibay’s research team has shown that crystals offer an opportunity to control the outcome of these chemical reactions.

His research has applications for green chemistry — the design of chemical products and processes that reduce or eliminate the generation of hazardous substances — and it could lead to the production of specialty chemicals that would be very difficult to produce using traditional methods. Among his many honors, he was elected a fellow of the American Chemical Society in 2019.

Lynn Vavreck is UCLA’s Marvin Hoffenberg Professor of American Politics and Public Policy, a contributing columnist to the Upshot at the New York Times, and a recipient of many awards and honors, including the Andrew F. Carnegie Prize in the Humanities and Social Sciences. She is the author of five books, including “Identity Crisis: The 2016 Presidential Campaign and the Battle for the Meaning of America” and “The Gamble: Choice and Chance in the 2012 Presidential Election,” which has been described as the “definitive account” of that election.

Consultants in both political parties refer to her work on political messaging in “The Message Matters” as required reading for presidential candidates. “Identity Crisis” was awarded the 2019 Richard E. Neustadt Prize for the Best Book on Executive Politics by the Presidents and Executive Politics Section of the American Political Science Association.

Vavreck’s 2020 election project, Nationscape, is the largest study of presidential elections ever conducted in the United States. Interviewing more than 6,000 people a week, Nationscape will complete 500,000 interviews before next January’s inauguration.

► Read more about the Nationscape election project.

“The members of the class of 2020 have excelled in laboratories and lecture halls, they have amazed on concert stages and in surgical suites, and they have led in board rooms and courtrooms,” said David Oxtoby, president of the Academy. “With [the] election announcement, these new members are united by a place in history and by an opportunity to shape the future through the Academy’s work to advance the public good.”

The American Academy of Arts and Sciences was founded in 1780 by John Adams, John Hancock and others who believed the new republic should honor exceptionally accomplished individuals. Previous fellows have included George Washington, Benjamin Franklin, Alexander Hamilton, Ralph Waldo Emerson, Albert Einstein, Charles Darwin, Winston Churchill, Martin Luther King Jr. and Nelson Mandela.

It also is an independent policy research center that undertakes studies of complex and emerging problems. Current academy members represent today’s innovative thinkers in many fields and professions, including more than 250 Nobel and Pulitzer Prize winners.

This article originally appeared in the UCLA Newsroom.

An image of dust over the Sahara Desert.

Earth’s atmosphere far dustier than previously believed

An image of dust over the Sahara Desert.

Dust over the Sahara Desert (Photo Credit: NASA GSFC)

Dust is a key component of Earth’s climate system. When it interacts with clouds, oceans and the sun’s radiation, it has an overall impact on our planet’s living systems, affecting everything from weather and rainfall to global warming.

There are two types of dust in the atmosphere, both kicked up by high-velocity winds in dry areas. Fine dust tends to cool because it scatters sunlight, much like clouds do. Coarse dust, which is larger in size and originates in places like the Sahara Desert, tends to warm the atmosphere, much like greenhouse gases.

Knowing precisely how much coarse dust is in the atmosphere is essential for understanding not only the atmospheric phenomena that dust influences but also the degree to which dust may be warming the planet.

Now, UCLA scientists report that there is four times the amount of coarse dust in Earth’s atmosphere than is currently simulated by climate models. Their findings appear in the journal Science Advances.

The researchers found that Earth’s atmosphere contains 17 million metric tons of coarse dust — equivalent to 17 million elephants or the mass of every person in America put together.

“To properly represent the impact of dust as a whole on the Earth system, climate models must include an accurate treatment of coarse dust in the atmosphere,” said the study’s first author, Adeyemi Adebiyi, a postdoctoral researcher in UCLA’s Department of Atmospheric and Oceanic Sciences and a recipient of the University of California President’s Postdoctoral Fellowship.

By plugging this amount of missing coarse dust into models, Adebiyi said, it increases the likelihood that the net amount of dust overall — both fine and coarse — is warming rather than cooling the Earth’s climate system, from air to oceans.

Coarse dust particles warm the Earth’s entire climate system by absorbing both incoming radiation from the sun and outgoing radiation from the Earth’s surface. These particles can impact stability and circulation within our atmosphere, which may affect atmospheric phenomena like hurricanes.

Adebiyi worked with Jasper Kok, a UCLA associate professor of atmospheric and oceanic sciences, to determine the actual amount of coarse dust in the atmosphere by analyzing dozens of published aircraft-based observations, including recent measurements taken over the Sahara Desert, and comparing those with half a dozen widely used global atmospheric model simulations.

“When we compared our results with what is predicted by current climate models, we found a drastic difference,” Kok said. “State-of-the-art climate models account for only 4 million metric tons, but our results showed more than four times that amount.”

In addition, Adebiyi and Kok found that coarse dust leaves the atmosphere less quickly than current climate models predict. Air has a tendency to mix more turbulently when dust is present. In the case of the Sahara, air and dust mix in ways that push the dust upward, which can work against gravity and keep the dust in the air much longer, they said.

The scientists’ findings also show that because dust particles stay in the atmosphere longer, they are ultimately deposited further from their source than has been predicted by these models or explained by current theory. Dust particles blown from the Sahara, for example, can travel thousands of miles in the atmosphere, reaching as far as the Caribbean and the United States.

When desert dust ends up in oceans, it may stimulate the productivity of ocean ecosystems and increase the amount of carbon dioxide absorbed by the oceans.

Due to the way coarse dust interacts with the sun’s energy and clouds, it can also have a major impact on the timing of precipitation, as well as how much, or how little, rain falls.

“Models have been an invaluable tool for scientists,” said Adebiyi, “but when they miss most of the coarse dust in the atmosphere, it underestimates the impact that this type of dust has on critical aspects of life on Earth, from precipitation to cloud cover to ocean ecosystems to global temperature.”

This article originally appeared in the UCLA Newsroom.

A photo of a valley oak tree.

UCLA College Celebrates Earth Day

A photo of a Griffith Park vista; the view of the Los Angeles skyline from Griffith Park.

Los Angeles County is home to more than 4,000 distinct species of plants and animals, and the sustainability plan aims for “no loss of native biodiversity.” (Photo Credit: Jake Dobkin)

Not only does this mark its 50th anniversary, this Earth Day is unlike any other we have seen as the global pandemic continues to impact the way we live our lives. Yes, it has disrupted our daily routines but it has also benefited the environment in myriad ways. For example, freeways once clogged with traffic have opened up, clearing the air and making way for bright blue skies and views for miles. Even before COVID-19, UCLA College faculty members and teams were out in the field and in their labs, working on groundbreaking research and advising on county and statewide plans. In honor of Earth Day, we are highlighting stories about conservation, sustainability, global warming, solar geoengineering and protecting our precious ecosystems.

 

A photo of vegetation and mountains in California's Anza-Borrego State Park.

Vegetation and mountains in California’s Anza-Borrego State Park. (Photo Credit: Sean Brenner/UCLA)

UCLA to lead $10 million California conservation project

UCLA scientists are leading a $10 million project to help California officials make ecologically wise decisions as the state continues to confront the effects of climate change. The initiative will give California officials scientific data they can use to make decisions about conserving the state’s ecosystems.

A photo of a valley oak tree.

The valley oak, the largest oak in California, grows to over 100 feet tall and provides habitat and food for a variety of animals. (Photo Credit: Victoria Sork/UCLA)

One of California’s iconic tree species offers lessons for conservation

New research led by UCLA evolutionary biologist Victoria Sork examines whether the trees being replanted in the wake of California’s fires will be able to survive a climate that is continuing to warm. The study, which is published in the Proceedings of the Natural Academy of Sciences, focuses on California’s iconic valley oak.

A photo of a Griffith Park vista; the view of the Los Angeles skyline from Griffith Park.

Los Angeles County is home to more than 4,000 distinct species of plants and animals, and the sustainability plan aims for “no loss of native biodiversity.” (Photo Credit: Jake Dobkin)

L.A. County taps UCLA to help create first-ever sustainability plan

The Los Angeles County Board of Supervisors unanimously approved an ambitious sustainability plan that calls for phasing out fossil fuels to address climate change and improve quality of life in the region. Sixteen UCLA researchers contributed to the OurCounty plan, which was created by the county’s Chief Sustainability Office.

A photo of the Santa Monica Pier at night.

The Santa Monica Pier at night. Artificial light can cause problems for a range of species that live and breed in coastal environments. (Photo Credit: William Chen/Pexels)

Study draws Southern California coastal light pollution into focus

Artificial light is known to disrupt mating cycles in species along the Southern California coast. A team of UCLA and University of Southern California researchers led by Travis Longcore, UCLA adjunct professor of urban conservation biology, has mapped light pollution conditions that will be used to inform decisions about future infrastructure and construction plans.

A photo of members of the UCLA Center for Diverse Leadership in Science, which was founded by Aradhna Tripati, associate professor in the UCLA Institute of the Environment and Sustainability.

Members of the Center for Diverse Leadership in Science, which was founded by Professor Aradhna Tripati, third row, far right, and their colleagues. (Photo: Courtesy of Aradhna Tripati)

Professor pays it forward by promoting diversity and environmental justice

When she was appointed in 2009, Aradhna Tripati was the first woman of color out of 50 faculty in UCLA’s Institute of the Environment and Sustainability. Along with colleagues in UCLA’s Anthropology department and American Indian Studies Center, she conducts community engaged research on water in the context of global warming in the southwestern United States. She also formed the first university-based center for diversity in environmental science, with the goal of inspiring a generation of leaders that matches the demographics of the U.S. population.

Andrea Bertozzi (Photo Credit: Courtesy of Andrea Bertozzi)

Mathematics professors earn NSF grant to calculate COVID-19 transmission rates

A photo of Andrea Bertozzi

Andrea Bertozzi (Photo Credit: Courtesy of Andrea Bertozzi)

Uncertainty about COVID-19 transmission rates has been one of the major challenges for health care systems in the United States and around the world.

UCLA mathematics professors Andrea Bertozzi and Mason Porter will use mathematical modeling, incorporating the specific features of COVID-19, to provide insights to those who are developing strategies to mitigate the spread of the disease.

Bertozzi and Porter have been awarded a $200,000 rapid-response research grant from the National Science Foundation, which has called for proposals with the potential to address the spread of COVID-19.

Many public health and infectious disease experts believe the actual transmission of COVID-19 is likely much higher than what has been publicly reported. The UCLA project will extend prior research on contagions, factoring in multiple transmission methods, human behavior patterns, current data and more. It also will provide training for a postdoctoral scholar, a doctoral student and two undergraduates.

Bertozzi and her research team have already published a preprint of a research paper on the challenges of modeling and forecasting the spread of COVID-19, and she and Porter are conducting research on another related paper as part of the project.

Bertozzi holds UCLA’s Betsy Wood Knapp Chair for Innovation and Creativity.

The award is co-funded by NSF programs in applied mathematics and computational mathematics and its office of multidisciplinary activities.

This article originally appeared in the UCLA Newsroom.

 

A photo of Professor Neil Garg

How did organic chemistry become so beloved at UCLA? Professor Neil Garg is glad you asked

People who don’t know Neil Garg may be shocked to learn he has made organic chemistry — the chemistry of molecules made of carbon — one of UCLA’s most beloved and popular undergraduate courses. Students wait for years to get into his class and do celebratory dances when they learn they’re enrolled.

Garg, the Kenneth N. Trueblood Professor of Chemistry and Biochemistry, recently explained how he made the subject so popular and shared some of his teaching techniques in an article published in the Journal of Biological Chemistry. In 2018, Garg became the recipient of the country’s premier university teaching award, the Robert Foster Cherry Award for Great Teaching, given once every two years by Baylor University.

His undergraduate course Chemistry 14D, “Organic Reactions and Pharmaceuticals,” is very demanding. On exams, he asks students — mostly second-year, non-chemistry majors — to solve difficult problems he did not learn to solve until his first year of graduate school at Caltech. Students, for example, are asked to create a reasonable chemical synthesis of molecules they have never seen before. By the end of his course, more than two-thirds of the class can solve these problems.

A photo of Professor Neil Garg

Neil Garg reveals the teaching techniques that helped him to win the country’s premier university teaching award. (Photo Credit: Coral von Zumwalt)

“What is also striking,” Garg writes, “is that the students show impeccable creativity in their solutions, often providing reasonable responses that bear no resemblance to what is shown on the answer key, earning full credit. … My goal is always for students to do extraordinary things and learn to solve the hardest problems I can offer.”

In student surveys about Chemistry 14D more than two-thirds of the students rate their interest in organic chemistry as high, and fewer than 4% rate their interest in the subject as low. This is a dramatic shift from the start of the course when fewer than 10% reported a high rating, and more than 60% reported their interest as low.

In the article, Garg, who is also chair of UCLA’s department of chemistry and biochemistry, but not currently teaching organic chemistry, offers more than a dozen tips for teaching complex science. Among his practices:

-It’s essential to explain the relevance of organic chemistry to students and focus the class on problem-solving, critical thinking and creativity, rather than memorization. He teaches students that for each chemical reaction, there is a logic associated with how and why the reaction takes place. One of his students said she feels “like Sherlock Holmes when solving retrosynthesis problems.”

-He and his teaching assistants continually show students how much they care. Former student Elizabeth Matusov said, “He feels like a friend who happens to be teaching a really difficult class. He’s easily the best professor I’ve ever had. I would take any class with him. We all would.”

-He learns students’ names and calls on them by name, even in a class with 400 students. He stays in touch with hundreds of his former students, including some from 20 years ago.

-He teaches the fundamental vocabulary of organic chemistry and the rules of chemical reactivity, and performs in-class demonstrations with students.

-He poses questions that students answer with clickers, so he can immediately learn what they understand and what concepts require further explanation.

-More than 1,300 of his students have teamed up to make hundreds of music videos that have been viewed around the world hundreds of thousands of times. Many of the best are in Garg’s Chemistry 14D Music Video Hall of Fame, which features such student classics as “I Will Survive,” “Alkenes Are Used for These,” “Chem 14 Dreams Mashup” and “Say Alkane.” While teaching a semester at Baylor University last year, his undergraduate students teamed up to create 37 videos, including a chemistry adaptation of ABBA’s “Dancing Queen.”

-He has created educational resources for students, including BACON (Biology And Chemistry Online Notes), a set of fun and engaging online tutorials that make connections between organic chemistry and sports, health, genetics and popular television shows, among other topics. Other chemistry resources that are free and being used worldwide are a smartphone app called “Backside Attack” that teaches organic chemistry concepts; qrchem.net; and rschemistry.com. QR Chem, a molecule visualization app created by Garg and some of his UCLA students, is being used in more than 160 countries.

Summing up his teaching philosophy, Garg asks, “How did organic chemistry become one of UCLA’s most popular classes? Teaching is all about the students. We must challenge them, support them, make them feel connected to the class and give them opportunities to do amazing things.”

In an acknowledgment at the end of the article, Garg thanks, among others, his “thousands of inspiring students.”

Garg and his family live in a campus residence hall as part of UCLA’s faculty-in-residence program, which allows him to dine with students, advise them, go on trips with them and inspire them daily with his passion for chemistry.

This article originally appeared in the UCLA Newsroom.

A photo of a 3D atomic structure information of a 2D material that was previously inaccessible due to the limitations of 2D images. A 2D image is shown beneath the 3D atomic coordinates of molybdenum in blue, sulfur in yellow and rhenium dopants in orange.

UCLA-led research team produces most accurate 3D images of ‘2D materials’

A photo of a 3D atomic structure information of a 2D material that was previously inaccessible due to the limitations of 2D images. A 2D image is shown beneath the 3D atomic coordinates of molybdenum in blue, sulfur in yellow and rhenium dopants in orange.

Image showing the 3D atomic coordinates of molybdenum (blue), sulfur (yellow) and added rhenium (orange). A 2D image is shown beneath the 3D model. (Photo Credit: Dennis Kim/UCLA)

A UCLA-led research team has produced in unprecedented detail experimental three-dimensional maps of the atoms in a so-called 2D material — matter that isn’t truly two-dimensional but is nearly flat because it’s arranged in extremely thin layers, no more than a few atoms thick.

Although 2D-materials–based technologies have not yet been widely used in commercial applications, the materials have been the subject of considerable research interest. In the future, they could be the basis for semiconductors in ever smaller electronics, quantum computer components, more-efficient batteries, or filters capable of extracting freshwater from saltwater.

The promise of 2D materials comes from certain properties that differ from how the same elements or compounds behave when they appear in greater quantities. Those unique characteristics are influenced by quantum effects — phenomena occurring at extremely small scales that are fundamentally different from the classical physics seen at larger scales. For instance, when carbon is arranged in an atomically thin layer to form 2D graphene, it is stronger than steel, conducts heat better than any other known material, and has almost zero electrical resistance.

But using 2D materials in real-world applications would require a greater understanding of their properties, and the ability to control those properties. The new study, which was published in Nature Materials, could be a step forward in that effort.

The researchers showed that their 3D maps of the material’s atomic structure are precise to the picometer scale — measured in one-trillionths of a meter. They used their measurements to quantify defects in the 2D material, which can affect their electronic properties, as well as to accurately assess those electronic properties.

“What’s unique about this research is that we determine the coordinates of individual atoms in three dimensions without using any pre-existing models,” said corresponding author Jianwei “John” Miao, a UCLA professor of physics and astronomy. “And our method can be used for all kinds of 2D materials.”

Miao is the deputy director of the STROBE National Science Foundation Science and Technology Center and a member of the California NanoSystems Institute at UCLA. His UCLA lab collaborated on the study with researchers from Harvard University, Oak Ridge National Laboratory and Rice University.

The researchers examined a single layer of molybdenum disulfide, a frequently studied 2D material. In bulk, this compound is used as a lubricant. As a 2D material, it has electronic properties that suggest it could be employed in next-generation semiconductor electronics. The samples being studied were “doped” with traces of rhenium, a metal that adds spare electrons when replacing molybdenum. That kind of doping is often used to produce components for computers and electronics because it helps facilitate the flow of electrons in semiconductor devices.

To analyze the 2D material, the researchers used a new technology they developed based on scanning transmission electron microscopy, which produces images by measuring scattered electrons beamed through thin samples. Miao’s team devised a technique called scanning atomic electron tomography, which produces 3D images by capturing a sample at multiple angles as it rotates.

The scientists had to avoid one major challenge to produce the images: 2D materials can be damaged by too much exposure to electrons. So for each sample, the researchers reconstructed images section by section and then stitched them together to form a single 3D image — allowing them to use fewer scans and thus a lower dose of electrons than if they had imaged the entire sample at once.

The two samples each measured 6 nanometers by 6 nanometers, and each of the smaller sections measured about 1 nanometer by 1 nanometer. (A nanometer is one-billionth of a meter.)

The resulting images enabled the researchers to inspect the samples’ 3D structure to a precision of 4 picometers in the case of molybdenum atoms — 26 times smaller than the diameter of a hydrogen atom. That level of precision enabled them to measure ripples, strain distorting the shape of the material, and variations in the size of chemical bonds, all changes caused by the added rhenium — marking the most accurate measurement ever of those characteristics in a 2D material.

“If we just assume that introducing the dopant is a simple substitution, we wouldn’t expect large strains,” said Xuezeng Tian, the paper’s co-first author and a UCLA postdoctoral scholar. “But what we have observed is more complicated than previous experiments have shown.”

The scientists found that the largest changes occurred in the smallest dimension of the 2D material, its three-atom-tall height. It took as little as a single rhenium atom to introduce such local distortion.

► Read a Nature analysis of the UCLA-led study

Armed with information about the material’s 3D coordinates, scientists at Harvard led by Professor Prineha Narang performed quantum mechanical calculations of the material’s electronic properties.

“These atomic-scale experiments have given us a new lens into how 2D materials behave and how they should be treated in calculations, and they could be a game changer for new quantum technologies,” Narang said.

Without access to the sort of measurements generated in the study, such quantum mechanical calculations conventionally have been based on a theoretical model system that is expected at a temperature of absolute zero.

The study indicated that the measured 3D coordinates led to more accurate calculations of the 2D material’s electronic properties.

“Our work could transform quantum mechanical calculations by using experimental 3D atomic coordinates as direct input,” said UCLA postdoctoral scholar Dennis Kim, a co-first author of the study. “This approach should enable material engineers to better predict and discover new physical, chemical and electronic properties of 2D materials at the single-atom level.”

Other authors were Yongsoo Yang, Yao Yang and Yakun Yuan of UCLA; Shize Yang and Juan-Carlos Idrobo of Oak Ridge National Laboratory; Christopher Ciccarino and Blake Duschatko of Harvard; and Yongji Gong and Pulickel Ajayan of Rice.

The research was supported by the U.S. Department of Energy, the U.S. Army Research Office, and STROBE National Science Foundation Science and Technology Center. The scanning transmission electron microscopy experiments were conducted at the Center for Nanophase Materials Sciences, a DOE user facility at Oak Ridge National Laboratory.

This article originally appeared in the UCLA Newsroom.

A photo of the Owens Valley lakebed.

Effort to limit dust pollution in Owens Valley is advancing, but still room to improve

A photo of the Owens Valley lakebed.

The Owens Valley lakebed with currently approved dust mitigation measures. (Photo Credit: David Colgan/UCLA)

The century-long battle over water between California’s Owens Valley and Los Angeles is nothing short of epic.

In 1974, the conflict was immortalized in the film “Chinatown.” The latest chapter comes in a more stoic but important form: a 157-page report from the National Academies of Sciences, Engineering and Medicine. The publication was created by a panel of experts that includes UCLA atmospheric dust specialist Gregory Okin.

Beginning in the late 1800s, William Mulholland quietly bought up land and water rights in Owens Valley, and in 1913, he started delivering the water from Owens Lake 233 miles south via aqueduct to a fast-growing Los Angeles.

The population of Los Angeles was 102,000 in 1910, but it had reached 319,000 in 1920 and then soared to 2 million by the middle of the century. Owens Valley, its lake drained of water, had become the largest source of dust in North America.

That dust included particulate matter measuring 10 micrometers or less in diameter, pollution that gets deep into people’s lungs and causes respiratory problems, particularly for sensitive groups. Ranchers, indigenous people and other residents of the valley were incensed, having lost their water and gained unhealthy air in its place.

The National Academies’ peer-reviewed report comes following decades of litigation that required the Los Angeles Department of Water and Power to take actions to mitigate the dust problem. Over the past two decades, the department has spent $2 billion on the effort.

And researchers found good news: Efforts between the department and Great Basin Unified Air Pollution Control District to control the issue have gone well. The work includes using gravel, managed vegetation and shallow flooding to mitigate dust. The air pollution district is a government agency responsible for protecting air quality in the east-central part of the state, near the Nevada border. It battled the Department of Water and Power in court for decades, but outside the courtroom the relationship is less contentious.

“The teams of people working on the ground together have been very successful,” said Okin, who is also a member of the UCLA Institute of the Environment and Sustainability. “There are still air quality exceedances that occur, but they are drastically smaller in magnitude and frequency than they were prior to 2000.”

That doesn’t mean there isn’t room for improvement. The report also recommended that processes for minimizing dust established 20 years ago should be updated with new technology and processes that would also help save water and power and preserve cultural and aesthetic values.

“Despite the fact that they’ve done a great job, they’ve done it in an ad hoc manner,” Okin said, referring to the two agencies. “There’s not a lot of logic as to what is being done and where.”

A photo of a crowd of 30,000 people who watched the first water cascade through the aqueduct in the San Fernando Valley.

A crowd of 30,000 watched the first water cascade through the aqueduct in the San Fernando Valley. (Photo Credit: Courtesy of waterandpower.org)

The methods workers can use to mitigate dust are strictly controlled by a series of legal agreements. And testing new methods poses a challenge, because testing is prohibited in the areas of the valley in which dust pollution has been substantially controlled.

“The only place you can test new measures is in areas that don’t need to be controlled, which is crazy,” Okin said.

The report suggests that the air pollution control district and the Department of Water and Power work together to redesign the entire system of dust control in the lakebed.

“The current work is probably using more water, power and heavy machinery than it needs to,” Okin said.

Better managing the area could also be a boon for wildlife. Currently, one of the main approaches to mitigating dust in the area is to plant grass, which requires a lot of irrigation. Okin suggested other native species could replace grass in some areas, which would save water and create new living spaces for birds, rare aquatic life and other species wildlife.

The report also notes that planning for future efforts must account for also climate change, which is projected to increase temperatures and make precipitation patterns and dry spells more extreme. The 2017 rainy season, for example, flooded the valley with more water than the Los Angeles Aqueduct could take, causing water levels in the mostly-dry lake to rise substantially.

The competing interests of the two main players could make it difficult to improve the situation further, Okin said. While the air pollution control district is primarily interested in dust mitigation, the Department of Water and Power cares mostly about conserving water as a resource. Bringing new efficiency and sustainability to the process would likely require further involvement of third parties such as the academies that created the report.

It’s been more than a century since Mulholland said, “There it is, take it,” as the first Owens Valley water flowed through the aqueduct into Los Angeles. Now, the question is how the next century of this drama, which affects the lives of millions, will unfold.

This article originally appeared in the UCLA Newsroom.