A New Method to Make a Massive Number of Anti-cancer Cells (Medicine)

The Shin Kaneko laboratory reports a new method that produces T cells at massive scale and clinical grade.

Cancer immunotherapies have quickly become the most potent medical attack against cancer. The patient’s own cells, namely T cells, are removed, manipulated and transplanted back. Building on this effort are scientists like CiRA Professor Shin Kaneko, who is using iPS cell technologies to prepare T cells for an “off-the-shelf” cancer immunotherapy.

In its latest study, his lab reports a new method to prepare clinical-grade T cells at mass scale. The method was shown to work using the iPS cell stock manufactured at CiRA, which has been the source for many other cell products that have been transplanted into patients in clinical trials.

In cancer immunotherapies, T cells are harvested from the patient’s blood and manipulated to enhance their antagonistic effects against cancer cells. Part of the manipulation includes proliferating the cells, akin to increasing the number of soldiers to a battle.

However, current methods can only proliferate T cells to a degree. Stem cells, iPS cells especially, on the other hand, can be proliferated almost without limit. Further, iPS cells can be then differentiated into just about any cell type including T cells. It is for this reason that the Kaneko lab is researching the use of iPS cells to prepare new cancer immunotherapies.

“The iPS cell stock provides us a clinical-grade starting source to produce T cells. However, there has been no effective method that differentiates the iPS cells under clinical standards,” said Kaneko.

Many cell types including blood cells have been manufactured from iPS cells without animal materials. CiRA Professor Koji Eto‘s platelet products are one example. However, Kaneko’s team claims its paper is the first to produce T cells from iPS cells in this condition at mass scale.

“Feeder-free and serum-free systems for pluripotent stem cell proliferation and hematopoietic differentiation are well established, but none are for T cells,” said Dr. Shoichi Iriguchi, who managed the project.

Key to their new differentiation system was the effects of two molecules known to have a role in T cell development: the chemokine SDF1α, or stromal cell defined factor 1 alpha, and the p38 inhibitor SB203580.

“We found SDF1α and SB203580 upregulated BCL11B gene, a master regulator of T cell commitment, while suppressing genes for myeloid commitment,” said Iriguchi.

With this new method, the researchers prepared T cells from the iPS cell stock.

“The stock is designed to serve as many patients as possible. Therefore, we anticipate that a successful immunotherapy using T cells generated from the iPS cell stock will be widely available,” said Kaneko.

The iPS cells were modified to express a T-cell receptor that would cause the resulting T cells to react to a gene commonly expressed in many cancer cells, Wilms tumor 1 (WT1). Transplanting the resulting T cells into mice suffering from cancer extended the lifespans by about 50%. The same cells were also compatible with chimeric antigen receptor (CAR) technology, which allows scientists to modify T cells to target a specific type of cancer.

“The advantage of combining CAR T therapy and iPS cells is that we can make many T cells from the iPS cell stock to attack the any type of cancer,” explained Kaneko.

Both CAR T and iPS cell therapies have made the news in recent years, but for different diseases. Iriguchi is optimistic that the combinatorial approach by the lab will make cancer immunotherapies available readily for anyone.

“The stock removes the need to take cells from the patient, which requires time. Instead, our goal is to make an ‘off-the-shelf’ T cell product from iPS cells that is no different than getting a blood transfusion in the hospital,” he said.

Featured image credit: Kyoto University


Reference: Iriguchi, S., Yasui, Y., Kawai, Y. et al. A clinically applicable and scalable method to regenerate T-cells from iPSCs for off-the-shelf T-cell immunotherapy. Nat Commun 12, 430 (2021). https://www.nature.com/articles/s41467-020-20658-3 https://doi.org/10.1038/s41467-020-20658-3


Provided by Kyoto University

Climate Change, Bats Linked to COVID-19 Pandemic (Biology)

Global greenhouse gas emissions over the last century have made southern China a hotspot for bat-borne coronaviruses, by driving growth of forest habitat favored by bats. That’s the finding of a new study published in Science of the Total Environment by a team of researchers, including Camilo Mora from the University of Hawaiʻi at Mānoa. It provides the first evidence that climate change could have played a direct role in the emergence of SARS-CoV-2, the virus that caused the COVID-19 pandemic.

The study revealed large-scale changes in the type of vegetation in the southern Chinese Yunnan province, and adjacent regions in Myanmar and Laos, over the last century. Fueled by climatic changes including increases in temperature, sunlight and atmospheric carbon dioxide—which affect the growth of plants and trees—these habitats have changed from tropical shrubland to tropical savannah and deciduous (trees and shrubs that seasonally shed leaves) woodland. This created a suitable environment for many bat species that predominantly live in forests.

The study found that the number of coronaviruses in an area is closely linked to the number of different bat species present. An additional 40 bat species have moved into the southern Chinese Yunnan province in the past century, harboring around 100 more types of bat-borne coronavirus. This “global hotspot” is the region where genetic data suggests SARS-CoV-2 may have arisen.

The study suggests that as climate change altered habitats, species left some areas and moved into others—taking their viruses with them. This not only altered the regions where viruses are present, but most likely allowed for new interactions between animals and viruses, causing more harmful viruses to be transmitted or evolve.

“The fact that climate change can accelerate the transmission of wildlife pathogens to humans should be an urgent wake-up call to reduce global emissions,” said Mora, an associate professor of geography in the College of Social Sciences.

“Understanding how the global distribution of bat species has shifted as a result of climate change may be an important step in reconstructing the origin of the COVID-19 outbreak,” said lead author Robert Beyer, a researcher in the University of Cambridge’s Department of Zoology and research fellow at the Potsdam Institute for Climate Impact Research, Germany.

Estimated increase in the local number of bat species due to shifts in their geographical ranges driven by climate change between the 1901-1930 and 1990-2019 period. The zoomed-in area represents the likely spatial origin of the bat-borne ancestors of SARS-CoV-1 and 2. © UHM

The researchers echo calls from previous studies that urge policymakers to acknowledge the role of climate change in outbreaks of viral diseases, and to address climate change as part of COVID-19 economic recovery programs.

This research was supported by the European Research Council. It is an example of UH Mānoa’s goal of Excellence in Research: Advancing the Research and Creative Work Enterprise (PDF), one of four goals identified in the 2015–25 Strategic Plan (PDF), updated in December 2020.

Featured image: Microscopic image of SARS-CoV-2, the virus that causes COVID-19. Photo credit: NIAID-RML


Reference: Robert M. Beyer, Andrea Manica, Camilo Mora, Shifts in global bat diversity suggest a possible role of climate change in the emergence of SARS-CoV-1 and SARS-CoV-2, Science of The Total Environment, 2021, 145413, ISSN 0048-9697, https://doi.org/10.1016/j.scitotenv.2021.145413. (https://www.sciencedirect.com/science/article/pii/S0048969721004812)


Provided by University of Hawaii at Manoa

800-year-old Taro Farming Techniques Revealed (Archeology)

Ancient Hawaiian farmers may have used sophisticated engineering techniques to grow taro as far back as 800 years ago, according to research conducted by a University of Hawaiʻi at Mānoa team.

In July and August 2020, Department of Anthropology Professor Patrick Kirch, graduate students and Molokaʻi community volunteers spent five weeks on the Friendly Isle conducting an archaeological mission in Hālawa Valley. Archaeological surveys and excavations took place in two of the valley’s ʻili or traditional land sections.

“Some of the most interesting finds were made at two sets of stone-faced terraces that appear to have been irrigated from side-valley streams in Pualaulau and Kapana,” Kirch said. “These smaller field systems were not like typical loʻi (taro patches) found on the main valley floor, but rather were constructed in and around boulder fields, a remarkable kind of engineering.”

Kirch added, “From our excavations, it appears that the farmers who constructed these fields used a form of ‘hydraulic engineering’ to move sediments from the stream bed into the terraces, to build up soil that could then be planted in taro.”

The mapping revealed extensive sets of ancient agricultural terraces along with house sites and several agricultural heiau. Excavations yielded charcoal samples that are now being analyzed and radiocarbon dated, which will provide a chronology for the development of the valley’s agricultural system. Other samples are being analyzed for microscopic pollen, plant silica “skeletons” and starch grains to determine which crops were being grown.

Educational opportunity

Agricultural terraces in Hālawa Valley on Molokaʻi © University of Hawaii at Manoa

The magnitude of the discovery was not lost on anthropology graduate student Kylie Tuitavuki, who is benefiting from the STEM training opportunity for Native Hawaiians and other underrepresented stakeholders in field settings.

“I am a big proponent of community-based archaeology, and strongly believe that research should be done with and for the people,” Tuitavuki said. “The archaeology part was great, but the stories, histories and connections we made with community members was the best part of the field season. I was excited to be able to work in the region where my family is from.”

Kirch’s team will continue its research in Hālawa Valley this year, with the goal of understanding how the ancient “hydraulic engineers” of Hawaiʻi created sustainable and productive agricultural systems that endured for centuries.

This research is an example of UH Mānoa’s goal to promote Excellence in Research: Advancing the Research and Creative Work Enterprise (PDF), one of four goals identified in the 2015–25 Strategic Plan (PDF), updated in December 2020.

Supporting Kirch’s work

Arlen and Debra Prentice © University of Hawaii at Manoa

Kirch’s work is supported by his longtime friend Debra Prentice. A UH Mānoa graduate student with research focused on Polynesian societies in the late 1970s when she met Kirch, Prentice said giving back to UH Mānoa during one of the most challenging years is testament to her lifelong interest in anthropology, her commitment to academic research and a friendship standing the test of time.

She and her husband recently established the Debra and Arlen Prentice Research Fund for Pacific Island Archaeology and Anthropology. Housed in the Foundation, their gift will support a graduate research assistant and discretionary expenses.

“Pat’s work is important,” Prentice said. “I firmly believe that in order to move forward and solve some of our challenges in today’s complex world, we need to understand our history, to know where we came from and how we got here. Prehistory can teach us so much.”

Featured image: Patrick V. Kirch © University of Hawaii at Manoa


This science news is confirmed by us from Department of Anthropology at University of Manoa


Provided by University of Hawaii at Manoa

Artificial Aorta Can Reduce Patients’ Blood Pressure (Medicine)

Engineers at EPFL’s Center for Artificial Muscles have developed a silicone aorta that can reduce how hard patients’ hearts have to pump. Their breakthrough could offer a promising alternative to heart transplants.

“Over 23 million people around the world suffer from heart failure. The disease is usually treated with a transplant, but because donated hearts are hard to come by, there is an ongoing need for alternative therapies. With new developments in cardiac assistance systems, we can delay the need for a transplant – or even eliminate it altogether,” says Professor Yves Perriard, head of EPFL’s Center for Artificial Muscles within the School of Engineering. He and a team of around ten other engineers from EPFL’s Integrated Actuators Laboratory (LAI) have been working on new cardiac assistance technology over the past four years. Their discovery, which employs flexible actuators, has been published in Advanced Science.

Electrodes and a silicon aorta 

Our aortas are naturally elastic. They expand as blood is pumped into them from the heart’s left ventricle, and then contract to distribute the blood to the rest of the body. But in patients suffering from diseases such as heart failure, the heart has to work harder to accomplish this cycle. To ease the burden on the heart, EPFL engineers have designed an artificial aorta made of silicon and a series of electrodes. Their device is implanted just behind the aortic valve and amplifies the aorta’s efforts, working like an “augmented aorta.” When an electric voltage is applied to the device, the artificial aorta expands to a diameter that’s larger than the natural aorta. “The advantage of our system is that it reduces the pressure on a patient’s heart. The idea isn’t to replace the heart, but to assist it,” says Yoan Civet, a Scientist at the LAI. 

© 2021 EPFL

Helping the heart expend less energy 

To validate their system, the engineers built a simulator consisting of pumps and chambers that replicate the blood-flow and pressure conditions within a human heart. “By testing our device on the simulator, we were able to reduce the amount of cardiac energy required by 5.5%,” says Civet. The research team now plans to conduct further tests of their artificial aorta, and are already working on a new design that delivers better performance. 

© Félix Wey, Werner Siemens Stiftung / 2021 EPFL

However, the real challenge lies in the manufacturing step. “We started from scratch and had to develop a new production process that would allow us to increase the volume of the silicone tube. We also had to overcome a problem of electric breakdown. Due to our multi-layer design, only half as affordable electric field was reached as compared to a single-membrane system. We had to troubleshoot the problem and then come up with a solution,” says Civet. The research team has filed a patent for their technology. The hope is that their discovery can be used to treat other medical conditions, such as urological disorders, that require a similar approach.

Funding

This research was carried out under a joint initiative by ETH Zurich, the University of Bern and EPFL. The consortium has received a 12-year, CHF 12 million grant from the Werner Siemens Foundation to develop a cardiac assistance system, a urology system and a facial reconstruction system all based on flexible actuators.

Featured image: © Félix Wey, Werner Siemens Stiftung / 2021 EPFL


References: M. Almanza, F. Clavica, J. Chavanne, D. Moser, D. Obrist, T. Carrel, Y. Civet and Y. Perriard, “Feasibility of A Dielectric Elastomer Augmented Aorta.” Adv. Sci. 2020, 2001974.


Provided by EPFL

EPFL Moves Boldly Into Space With Its CHESS Satellites (Astronomy)

The EPFL Spacecraft Team has set itself the ambitious goal of launching two satellites by 2023. With this bold initiative, this student team hopes to gain further insight into the chemical composition of the outermost layers of our atmosphere.

Designing a satellite and launching it into space is no run-of-the-mill project. Rather, it’s one that forever marks the early careers of the students who take part – just ask the EPFL students who designed the SwissCube, a 1U CubeSat (a small standardized unit measuring 10 cm x 10 cm) launched in 2009. Today, a new group of students, the EPFL Spacecraft Team, is taking on a new challenge. With the support of the EPFL Space Center (eSpace), they are developing a constellation of two satellites, called CHESS, that will be launched in two years. The team is currently seeking additional members and sponsors.

This ambitious project has already signed on six universities, three companies, 15 professors and 53 students.* The two satellites will work in concert; each one will be a 3U CubeSat bearing primary and secondary payloads. They will orbit at different altitudes – one will travel in a circular orbit at the low altitude of around 550 km, and the other will travel in an elliptic orbit at an altitude oscillating between 400 km and 1,000 km. The constellation will be launched in March 2023 and remain in flight for at least two years.

This project will give the students who participate each year a chance to learn about complicated space technology and gain experience working on a cross-disciplinary team. “It’s a way to learn the real-world skills required in our industry, like team management, coordination, communication and fundraising,” says Emmanuelle David, the deputy director of eSpace. “These are skills you can’t learn only from a book. And they will let the students become operational as soon as they start their first job or when and if they decide to start their own business.”

One satellite will be placed in a circular orbit at around 550 km, while the other will travel in an elliptic orbit between 400 km and 1,000 km. © EPFL

Understanding the exosphere’s chemistry

In addition to giving students valuable experience, the CHESS mission will have several other objectives. The first is scientific. As the two satellites orbit around the Earth, they will collect detailed information about the exosphere – the outermost layer of the atmosphere, starting at 400 km above the planet’s surface. Since the satellites will follow separate orbits, they will collect complementary spatial and temporal datasets.

“The last time this layer of the atmosphere was analyzed in detail was nearly 40 years ago,” says Dr. Rico Fausch, a physicist at the University of Bern’s Space Research & Planetary Sciences Department. “So these updated data will be very useful in helping us better understand the exosphere’s chemistry and how it has changed over time, especially in light of global warming. They will also let us check whether the upper layers of the atmosphere are indeed cooling as recent studies have suggested – which would be another direct consequence of the accumulation of greenhouse gases around our planet.”

© EPFL

The satellites will collect detailed data on the various gases in the exosphere – nitrogen, oxygen, ozone, carbon dioxide, hydrogen, helium, etc. – and their isotopes. The overall goal is to study temperature fluctuations, the processes and mechanisms by which atmospheric gases escape into space, and how many free-floating electrons and ions there are in the exosphere. Molecules are much harder to find at high altitudes than low ones, since individual particles collide and bind together much more slowly.

Technological advancements

The CHESS mission also aims to spur technological innovation. The satellites will be equipped with state-of-the-art instruments, such as the new mass spectrometers being developed jointly by the University of Bern and the company Spacetek – two pioneers in this field. The spectrometers will be used to identify specific compounds and their chemical structures by taking mass measurements, and will be lighter and more efficient than the ones used back in the 1980s.

New technologies will be tested thanks to the CHESS mission © EPFL

The satellites will also feature next-generation Global Navigation Satellite System (GNSS) receivers that are lighter, less expensive, and more accurate than existing models. These receivers are being developed jointly by ETH Zurich and u-blox. They will not only record extremely precise data on the satellites’ positions (on the order of ±1 cm), but also measure air density and the number of free-floating electrons. In addition, the CHESS mission will perform in situ tests of a new kind of solar panel designed specifically for spacecraft, based on technology developed at RUAG. And because the two satellites will send radio communications to ground stations, they will help create a Swiss-wide X-band network – a communications network using an ultra-high-frequency radio band.

Switzerland’s growing space industry

“I was lucky enough to work with the team that designed, built and launched SwissCube – which is still operational today, some 11 years later,” says Muriel Richard, an aerospace engineer and the co-founder & CTO of ClearSpace. “I’ve been following the CHESS project closely for the past two years, and I see that these students are just as skilled, smart and motivated – and are worth believing in and investing in. They’ll send these satellites into orbit, that’s for sure!”

CHESS forms part of a broader trend of growing interest in space-industry R&D, both at EPFL and in Switzerland as a whole. The project will help train the next generation of aerospace engineers, pull together skills from a wide range of fields, expand the existing space-industry network and forge ties among the scientific community.

*Partner organizations: University of Bern, Hochschule Luzern, HES-SO Valais-Wallis, ETH Zurich, Haute École ARC, Spacetek, u-blox and RUAG

Presskithttps://go.epfl.ch/CHESS_satellites

Illustrations: One out of two CHESS Satellites ©E.Nardini /EPFL Spacecraft Team


Provided by EPFL

Meet Molecular Biologist Jonatan Matalonga-Borrel (Biology)

Matalonga-Borrel is on the hunt for a treatment that could help children born with a rare, life-threatening condition

Thanks to the sequencing of the human genome, scientists have helped parents get answers to the cause of mysterious conditions that have affected their children. Now, researchers are tackling a new challenge: translating this knowledge into life-altering medicines.

Molecular biologist Jonatan Matalonga-Borrel, Ph.D., a postdoctoral researcher in the Dong lab at Sanford Burnham Prebys, is at the forefront of this effort. We caught up with Matalonga-Borrel as he prepares to take the virtual stage at DASL (the Diversity and Science Lecture Series at UC San Diego) to learn more about his work and his interests outside of the lab.

When not in the lab, Matalonga-Borrel can often be found at Torrey Pines Golf Course, which is located across the street from Sanford Burnham Prebys. © SBP

Did you always know you wanted to be a scientist?

I actually wanted to be an airplane pilot until my senior year of high school. But during the application process, I learned that I have very mild color-blindness, so I had to quickly decide what I wanted to do next. I pivoted to biology, a topic where I had some interest, thinking I would become a teacher. Then, when I was in college, I got the opportunity to complete a lab internship, which is where I discovered my passion for research. I would have never guessed that I would be where I am today, leading a project that might directly help families and children.

What do you study, and what is your greatest hope for your research?

I study Alagille syndrome, a rare disease that affects kids from the day they are born. Many organs are affected, especially the heart and the liver, and almost half of these children die before the age of 19.

Luckily, Alagille syndrome is associated with mutations in only two genes, both belonging to the same pathway, called Notch. This makes our goal easier to achieve: identify drugs that target Notch, which currently don’t exist. I’m excited that we’ve identified a promising option. My greatest hope is to create a medicine that truly helps these children and their families, who currently live without any treatment.

Matalonga-Borrel poses with his son. He is grateful for Skype, which allowed his parents to “meet” their first grandchild despite the pandemic. © SBP

When you aren’t working in the lab, where can you be found?

You will likely find me playing golf at Torrey Pines! There is nothing like playing a twilight round, feeling a slight breeze and looking at the immensity of the Pacific Ocean. With that said, since I became a father, my golfing time has been severely impaired. Now it’s most likely that you’ll find me at home, entertained by the early stages of development of my son…and changing a lot of diapers!

What do you wish people knew about science?

How patient one has to be to move science forward. It can take weeks—or months—of trial and error until a big breakthrough happens.

We live in a world that seems to spin faster and faster. It is critical for our society to understand that proper science is not about rushing experiments. It is about setting the right ones.

How do you think your lab colleagues would describe you?

Upbeat, reliable and organized (hopefully!).

How has the pandemic affected your life?

I had my first baby last June, and the pandemic prevented any relatives to come from our home country, Spain, and meet their first grandchild. Thankfully, we had Skype to get in touch. Looking on the bright side, daycares have never been so clean, and the rate of sickness around kids has dropped significantly!

What is the best career advice you have ever received?

“Have fun and make friends,” from Dr. Eduardo Chini of the Mayo Clinic. It is possible to do great science and have fun—don’t feel guilty about it. My best collaborations came from my greatest friendships among colleagues.

What do you wish people knew about Sanford Burnham Prebys?

It’s an amazing community. Science moves forward thanks to communication and collaboration and it wouldn’t happen without a strong sense of community. This includes wise faculty members who train graduate students and postdocs, an Office of Education and International Services that offers year-round seminars and workshops, and a group I am part of, called SBP-Social Network (SBP-SN), which organizes fun social and scientific events. All of this creates a place where scientific excellence thrives.


Provided by SBP Discovery

Noise and Light Pollution Alter Bird Mating Behavior (Ornithology / Biology)

It’s not only climate change impacting bird reproduction.

Some bird species change their reproductive behaviours in response to noise and light pollution, according to a study published in the journal Nature. The findings raise new questions about how responses to sensory stimuli, like noise and light, interact with other global changes, like a warming climate. 

An international team of researchers, including Hokkaido University ecologist Masayuki Senzaki, wanted to develop a better understanding of the effects of human-made noise and light pollution on reproductive success in birds. Scientific understanding in this area is currently limited to a few species at the local scale. The team used citizen-gathered records between 2000 and 2014 on more than 58,500 nests belonging to 142 bird species across the United States and assessed how this information was associated with high-resolution noise and light data from the nesting areas.

The scientists found that reproductive behaviours in bird species living in more closed woodland habitats were more significantly impacted by noise and light pollution compared to bird species living in more open grasslands and wetlands.

Specifically, light pollution was associated with earlier egg laying in both open and closed habitat species. Also, closed habitat species living in well-lit areas produced 16% larger egg clutches than those living in darker areas. The scientists think this is due to longer foraging times available to birds in well-lit areas.

Distribution map of artificial noise in the United States. The shade of color indicates the magnitude of noise. The points in the figure are the positions of the bird nests used in the analysis. Red indicates a nest that failed to breed, and black indicates a nest that succeeded in breeding (Masayuki Senzaki, et al. Nature. November 11, 2020).

Closed habitat species were negatively impacted by noise pollution, with evidence of reduced clutch sizes, increased hatching failure and fewer offspring capable of flight.

Further analyses at the species level showed that birds with low frequency birdsong were more negatively affected by noise pollution than those with higher frequency vocals. Notably, many closed habitat species chirp in low frequencies. The scientists believe that noise pollution masks these lower frequencies, interfering with male stimulation of females and thus their receptivity to breeding.

Also, species that see well in low-lit conditions laid eggs earlier in response to light pollution. The scientists expected they would have less nesting success compared to birds who do not see as well in low-lit conditions, due to a mismatch between peak food availability and food need. Instead, they found the birds had better nesting success. The scientists think this is due to their ability to successfully track available resources as climate temperatures rise. 

“There is widespread consensus that climate change is causing temperate birds to reproduce earlier,” says Senzaki. “But our data is showing that the impacts usually attributed to temperature could be overestimated, due to being confounded by the impacts of light pollution. Similarly, delays in the onset of bird breeding due to exposure to noise pollution could be leading to the underestimation of the impacts of climate change.” The team recommends data re-evaluations to understand how the different elements of global change interact to impact bird reproduction behaviours worldwide.

Funding: This work was supported by the US National Science Foundation (NSF; 1414171, 1556177, 1556192, 1812280), the NASA Ecological Forecasting Grant (NNX17AG36G), and the Japan Society for the Promotion of Science (JSPS) KAKENHI (17J00646).

Featured image: Fledgling chicks of the Pacific-slope flycatcher, whose breeding success rate was reduced due to noise (Photo: Masayuki Senzaki).


Reference: Masayuki Senzaki, et al. Sensory pollutants alter bird phenology and fitness across a continent. Nature. November 11, 2020. DOI: 10.1038/s41586-020-2903-7


Provided by Hokkaido University

Extreme UV Laser Shows Generation of Atmospheric Pollutant (Chemistry)

Hokkaido University scientists show that under laboratory conditions, ultraviolet light reacts with nitrophenol to produce smog-generating nitrous acid.

An advanced laser technique has allowed researchers to observe, in real-time, the decomposition of a pollutant into atmospheric nitrous acid, which plays a key role in the formation of ozone and photochemical smog. The technique, described by Hokkaido University researchers in The Journal of Physical Chemistry Letters, could be used in a wide range of applications.

Nitrophenols are a type of fine particulate matter found in the atmosphere that form as a result of fossil fuel combustion and from forest fires. It is hypothesised that light interacts with nitrophenols and breaks them down into nitrous acid; atmospheric nitrous acid is known to generate the hydroxyl radicals responsible for ozone formation. Too much ozone and nitrogen oxides lead to the formation of an atmospheric haze called photochemical smog, which can cause respiratory illnesses. Until now, there has been no evidence for the decomposition of nitrophenol into nitrous acid by sunlight.

Hokkaido University applied physicist Taro Sekikawa and colleagues developed a new probing technique to observe the process in real-time. They then compared their measurements with theoretical quantum chemistry calculations.

“Our study showed that irradiation of o-nitrophenol with sunlight is one of the direct causes of nitrous acid production in the atmosphere,” says Sekikawa.

The team developed an advanced laser technique that involves exciting nitrophenol with a 400 nanometer-wavelength laser light and then shining very short, very fast pulses of ultraviolet light on it to see what happens. Specifically, they used extreme UV light, which has very short wavelengths, shone in femtoseconds, which last a millionth of a billionth of a second. The whole process measures the energy states and molecular changes that occur as the nitrophenol compound decomposes over time.

In the atmosphere, sunlight breaks down nitrophenol to form nitrous acid (HONO), which leads to photochemical smog (Taro Sekikawa).

The scientists found that nitrous acid begins to form 374 femtoseconds after the nitrophenol is first excited by light. The decomposition process involves distortion of the shape of the nitrophenol molecule by light irradiation and changes in its energy states, ultimately leading to the formation of nitrous acid.

“Photoelectron spectroscopy with extreme ultraviolet light is expected to have a wide range of applications as a method for measuring chemical reactions,” says Sekikawa. “It could be used, for example, to understand the mechanism by which ultraviolet rays inactivate viruses at the molecular level, and to understand other chemical reactions that take place in the atmosphere.

Associate Professor Taro Sekikawa (Photo: Taro Sekikawa).

Funding:

The work was financially supported by Ministry of Education, Culture, Sports, Science and Technology (MEXT) Quantum Leap Flagship Program (Q-LEAP; JPMXS0118068681), Japan Science and Technology Agency (JST) Core Research for Evolutional Science and Technology (CREST; JPMJCR15N1, JPMJCR1902) and KAKENHI (19H01814), and the Photoexcitonix Project in Hokkaido University.

Featured image: Extreme ultraviolet femtosecond pulse light source and photoelectron spectrometer, key instruments used in the experiment (Photo: Taro Sekikawa).


Reference: Yuki Nitta, et al. Real-Time Probing of an Atmospheric Photochemical Reaction by Ultrashort Extreme Ultraviolet Pulses: Nitrous Acid Release from o‑Nitrophenol. The Journal of Physical Chemistry Letters. January 4, 2021. DOI: 10.1021/acs.jpclett.0c03297


Provided by Hokkaido University

Desexing Cats Before 4 Months Can Reduce the Number of Unwanted Kittens (Biology)

Big-data research led by Professor Julia Beatty, Head of the Department of Veterinary Clinical Sciences; Chair Professor of Veterinary Medicine and Infectious Diseases; and Director of the Centre for Companion Animal Health at City University of Hong Kong (CityU), has found that although more than 80% of cats in Australia were desexed, only a fraction have had surgery before reaching puberty, thus creating a “pregnancy gap”. To close this gap and prevent unwanted litters, it is recommended that the age of desexing is before four months.

This recommendation is made by global organisations including the Royal Society for the Prevention of Cruelty to Animals and the International Society for Feline Medicine as unowned domestic cats are fast becoming a global problem, driven by the cats’ phenomenal reproductive success which carries significant economic, animal welfare and biodiversity costs.

Researchers at CityU and the University of Sydney studied anonymous medical records of over 52,000 cats brought into vet clinics, including pet cats, breeding cats, cats owned by shelters, and semi-owned cats in Australia. The research has been published in Scientific Reports.

Despite a clear move towards earlier desexing, the study has found that desexing at four months or younger was carried out in only 21.5% of female cats, while 59.8% of female cats had been desexed by six months of age.

Female cats were less likely than males to be desexed (at all) or to have undergone early-age desexing, which is suboptimal for preventing unwanted litters. A female can give birth to up to three litters of up to six kittens each year.

“This creates a potential pregnancy gap between the time the female cat reaches puberty and the age at surgery,” Professor Beatty said.

Early-age desexing is important to prevent unwanted kittens heading into overburdened and under-resourced shelters or into the stray cat population, which is detrimental to their well-being and puts additional stress on wildlife already impacted by other predators, habitat loss and global warming.

“The benefits of earlier desexing for cats, aside from birth control, include shorter surgery time, a smaller incision and a quicker recovery, and reduced cancer risk,” Professor Beatty added.

Desexing cats before 4 months can close the “pregnancy gap” and reduce the number of unwanted kittens. © CityU

The Jockey Club College of Veterinary Medicine and Life Sciences at CityU works closely with The Society for the Prevention of Cruelty to Animals (Hong Kong) (SPCA) which runs the Cat Colony Care Programme and other animal birth control programmes for local cat-owners.

According to a recent analysis at SPCA clinics, 93% of cats in Hong Kong have been desexed. Although the situation in Hong Kong is a little different to Australia where more cats roam outdoors with more opportunities to breed, important comparisons can be made.

“The SPCA has been very successful in educating owners to have their pets desexed, but there is still work to do in Hong Kong. It is very important for well-meaning carers who feed ‘community cats’ to ensure that those cats are desexed early,” said Dr Jane Gray, Chief Veterinary Surgeon of SPCA.

“Ironically, providing additional food to homeless cats without desexing them can actually make the stray cat problem worse,” said Dr Fiona Woodhouse, Deputy Director of Welfare at SPCA.

“We really hope the research encourages anyone caring for a free-roaming cat in Hong Kong to arrange for that cat to be desexed, preferably before they reach four months of age. This would be a win for cat welfare and would help to reduce the number of unwanted kittens,” said Professor Beatty.

Featured image: Big-data research led by Professor Beatty finds that only a fraction of cats in Australia have had surgery before reaching puberty.


Reference: Mazeau, L., Wylie, C., Boland, L. et al. A shift towards early-age desexing of cats under veterinary care in Australia. Sci Rep 11, 811 (2021). https://www.nature.com/articles/s41598-020-79513-6 https://doi.org/10.1038/s41598-020-79513-6


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