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Improving cancer treatments – A discovery by François Légaré’s team could lead to a more effective use of radiation therapy in oncology.

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MONTRÉAL, Dec. 14, 2023 /CNW/ – Ultrafast laser technology continues to surprise. While research in this field may seem rather abstract at first glance, it very often leads to concrete applications. This is particularly true in healthcare, where the technology can be used to treat certain cancers.

This application was discovered by the research team at the Advanced Laser Light Source Laboratory (ALLS) of the Institut national de recherche scientifique (INRS), following recent work directed by the Professor and Director of the Énergie Matériaux Télécommunications Research Centre (EMT Centre), François Légaré. This work is the result of a collaboration with medical physicists at the McGill University Health Centre (MUHC). The study, published in the journal Laser & Photonics Reviews, presents astonishing results that call into question certain aspects of our knowledge about high-power laser pulses—knowledge that had become common in the scientific community.

“For the first time, we showed that, under certain conditions, a laser beam tightly focused in ambient air can accelerate electrons reaching energies in the MeV (megaelectronvolts) range, the same order of magnitude as some irradiators used in radiation therapy for cancer,” says François Légaré, Director of the EMT Centre, INRS.

It was well established that focusing a laser pulse of sufficiently high intensity in ambient air would generate plasma at the focal point. This plasma acts as a source of electrons that can be accelerated to energies up to a few keV (kiloelectronvolts), at most. Until recently, it was not possible to reach higher energies in ambient air, due to a physical limitation.

The research team was able to demonstrate that electrons accelerated in ambient air can reach energies in the MeV (megaelectronvolts) range, i.e. around 1,000 times greater than this previously insurmountable limit.

Better cancer treatment

The breakthrough achieved by the team at INRS’s EMT Centre opens the door to major advances in medical physics. A prime example is FLASH radiotherapy, a novel approach to treating tumours that are resistant to conventional radiation therapy. It is a technique that can be used to deliver high doses of radiation in an extremely short time (a few microseconds rather than a few minutes). This better protects the healthy tissue around the tumour. This FLASH effect is still poorly understood in research but seems to involve a rapid deoxygenation of healthy tissues, reducing their sensitivity to radiation.

“No study has been able to explain the nature of the FLASH effect. However, the electron sources used in FLASH radiotherapy have similar characteristics to the one we produced by focusing our laser strongly in ambient air. Once the radiation source is better controlled, further research will allow us to investigate what causes the FLASH effect and to, ultimately, offer better radiation treatments to cancer patients,” explains Simon Vallières, postdoctoral researcher and first author of the study

Safer handling

This discovery has concrete implications. Firstly, it requires extra caution when handling laser beams that are tightly focused in ambient air.

“The electron energies observed (MeV) allow them to travel more than three meters in air, or several millimeters under the skin. This poses a radiation exposure risk for users of the laser source,” explains Simon Vallières.

Moreover, by taking measurements near the source, the team observed a high radiation dose rate of electrons – three to four times greater than those used in conventional radiotherapy.

“Uncovering this radiation hazard is an opportunity to implement safer practices in laboratories,” says Simon Vallières. The young researcher notes that handling highly focused laser beams in ambient air must be done carefully, and that scientists need to avoid exposure to high doses of radiation as they are harmful to your health.

About ALLS 

Unique in Canada, the Advanced Laser Light Source (ALLS), is a world-class research infrastructure based at INRS and focused on developing new types of laser-based sources with revolutionary applications. A member of the LaserNetUS network, the ALLS infrastructure has received funding from the ministère de l’Économie, de l’Innovation et de l’Énergie (MEIE), and the Canada Foundation for Innovation (CFI) under the Major Scientific Initiative program.

About the paper

S. Vallières, J. Powell, T. Connell, M. Evans, M. Lytova, F. Fillion-Gourdeau, S. Fourmaux, S. Payeur, P. Lassonde, S. MacLean, F. Légaré. High Dose-Rate MeV Electron Beam from a Tightly-Focused Femtosecond IR Laser in Ambient Air. Laser Photonics Rev. 2023, 2300078. https://doi.org/10.1002/lpor.202300078.

This research was funded by the Natural Sciences and Engineering Research Council of Canada (NSERC), the Fonds de recherche du Québec – Nature and Technologies (FRQNT), and the Digital Research Alliance of Canada.

SOURCE Institut National de la recherche scientifique (INRS)

For further information: Source: Julie Robert, National Institute of Scientific Research, [email protected]

 

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The body of a Ugandan Olympic athlete who was set on fire by her partner is received by family

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NAIROBI, Kenya (AP) — The body of Ugandan Olympic athlete Rebecca Cheptegei — who died after being set on fire by her partner in Kenya — was received Friday by family and anti-femicide crusaders, ahead of her burial a day later.

Cheptegei’s family met with dozens of activists Friday who had marched to the Moi Teaching and Referral Hospital’s morgue in the western city of Eldoret while chanting anti-femicide slogans.

She is the fourth female athlete to have been killed by her partner in Kenya in yet another case of gender-based violence in recent years.

Viola Cheptoo, the founder of Tirop Angels – an organization that was formed in honor of athlete Agnes Tirop, who was stabbed to death in 2021, said stakeholders need to ensure this is the last death of an athlete due to gender-based violence.

“We are here to say that enough is enough, we are tired of burying our sisters due to GBV,” she said.

It was a somber mood at the morgue as athletes and family members viewed Cheptegei’s body which sustained 80% of burns after she was doused with gasoline by her partner Dickson Ndiema. Ndiema sustained 30% burns on his body and later succumbed.

Ndiema and Cheptegei were said to have quarreled over a piece of land that the athlete bought in Kenya, according to a report filed by the local chief.

Cheptegei competed in the women’s marathon at the Paris Olympics less than a month before the attack. She finished in 44th place.

Cheptegei’s father, Joseph, said that the body will make a brief stop at their home in the Endebess area before proceeding to Bukwo in eastern Uganda for a night vigil and burial on Saturday.

“We are in the final part of giving my daughter the last respect,” a visibly distraught Joseph said.

He told reporters last week that Ndiema was stalking and threatening Cheptegei and the family had informed police.

Kenya’s high rates of violence against women have prompted marches by ordinary citizens in towns and cities this year.

Four in 10 women or an estimated 41% of dating or married Kenyan women have experienced physical or sexual violence perpetrated by their current or most recent partner, according to the Kenya Demographic and Health Survey 2022.

The Canadian Press. All rights reserved.

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The ancient jar smashed by a 4-year-old is back on display at an Israeli museum after repair

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TEL AVIV, Israel (AP) — A rare Bronze-Era jar accidentally smashed by a 4-year-old visiting a museum was back on display Wednesday after restoration experts were able to carefully piece the artifact back together.

Last month, a family from northern Israel was visiting the museum when their youngest son tipped over the jar, which smashed into pieces.

Alex Geller, the boy’s father, said his son — the youngest of three — is exceptionally curious, and that the moment he heard the crash, “please let that not be my child” was the first thought that raced through his head.

The jar has been on display at the Hecht Museum in Haifa for 35 years. It was one of the only containers of its size and from that period still complete when it was discovered.

The Bronze Age jar is one of many artifacts exhibited out in the open, part of the Hecht Museum’s vision of letting visitors explore history without glass barriers, said Inbal Rivlin, the director of the museum, which is associated with Haifa University in northern Israel.

It was likely used to hold wine or oil, and dates back to between 2200 and 1500 B.C.

Rivlin and the museum decided to turn the moment, which captured international attention, into a teaching moment, inviting the Geller family back for a special visit and hands-on activity to illustrate the restoration process.

Rivlin added that the incident provided a welcome distraction from the ongoing war in Gaza. “Well, he’s just a kid. So I think that somehow it touches the heart of the people in Israel and around the world,“ said Rivlin.

Roee Shafir, a restoration expert at the museum, said the repairs would be fairly simple, as the pieces were from a single, complete jar. Archaeologists often face the more daunting task of sifting through piles of shards from multiple objects and trying to piece them together.

Experts used 3D technology, hi-resolution videos, and special glue to painstakingly reconstruct the large jar.

Less than two weeks after it broke, the jar went back on display at the museum. The gluing process left small hairline cracks, and a few pieces are missing, but the jar’s impressive size remains.

The only noticeable difference in the exhibit was a new sign reading “please don’t touch.”

The Canadian Press. All rights reserved.

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B.C. sets up a panel on bear deaths, will review conservation officer training

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VICTORIA – The British Columbia government is partnering with a bear welfare group to reduce the number of bears being euthanized in the province.

Nicholas Scapillati, executive director of Grizzly Bear Foundation, said Monday that it comes after months-long discussions with the province on how to protect bears, with the goal to give the animals a “better and second chance at life in the wild.”

Scapillati said what’s exciting about the project is that the government is open to working with outside experts and the public.

“So, they’ll be working through Indigenous knowledge and scientific understanding, bringing in the latest techniques and training expertise from leading experts,” he said in an interview.

B.C. government data show conservation officers destroyed 603 black bears and 23 grizzly bears in 2023, while 154 black bears were killed by officers in the first six months of this year.

Scapillati said the group will publish a report with recommendations by next spring, while an independent oversight committee will be set up to review all bear encounters with conservation officers to provide advice to the government.

Environment Minister George Heyman said in a statement that they are looking for new ways to ensure conservation officers “have the trust of the communities they serve,” and the panel will make recommendations to enhance officer training and improve policies.

Lesley Fox, with the wildlife protection group The Fur-Bearers, said they’ve been calling for such a committee for decades.

“This move demonstrates the government is listening,” said Fox. “I suspect, because of the impending election, their listening skills are potentially a little sharper than they normally are.”

Fox said the partnership came from “a place of long frustration” as provincial conservation officers kill more than 500 black bears every year on average, and the public is “no longer tolerating this kind of approach.”

“I think that the conservation officer service and the B.C. government are aware they need to change, and certainly the public has been asking for it,” said Fox.

Fox said there’s a lot of optimism about the new partnership, but, as with any government, there will likely be a lot of red tape to get through.

“I think speed is going to be important, whether or not the committee has the ability to make change and make change relatively quickly without having to study an issue to death, ” said Fox.

This report by The Canadian Press was first published Sept. 9, 2024.

The Canadian Press. All rights reserved.

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