Tag Archives: frozen

Why Natural Ovulation is the Optimal Choice Before IVF Frozen Embryo Transfer

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IVF Treatment Options

Exploring Diverse IVF Treatment Options: Insights and Effectiveness Research

Credit: Zephyr/Science Photo Library

Recent findings from a comprehensive randomized trial indicate that natural ovulation methods for preparing the uterus for frozen embryo transfer after in vitro fertilization (IVF) are equally effective and come with fewer risks compared to traditional hormone therapy.

Emerging data suggests that for women with strong responses to IVF treatment (which can yield multiple eggs), freezing embryos and transferring them in a later cycle can enhance success rates. Consequently, frozen embryos now represent the majority of embryo transfers conducted globally.

Post-IVF, the crucial timing for transferring frozen embryos into the uterus occurs during the menstrual cycle when the endometrium (the uterine lining) is adequately thick to facilitate implantation.

Women can opt for either a medicated cycle, which involves administering estrogen and progesterone for uterine preparation, or a natural cycle, where the body’s natural hormone production is monitored, assuming regular cycles.

Determining the optimal choice remains complex due to a lack of substantial trials evaluating the complications linked to these varying methods.

To address this uncertainty, Daimin Wei and a team from Shandong University in Jinan, China, conducted a large-scale clinical trial involving 4,376 women across 24 fertility treatment centers. All participants were aged 20 to 40 and were slated for a single frozen embryo transfer. Participants were divided equally between the medicated and natural cycle groups.

“This is the randomized controlled trial we’ve been waiting for,” remarks William Bucket from McGill University in Montreal, Canada, who was not involved in the study.

Live birth rates were comparable between both methods, with 41.6% in the natural cycle group and 40.6% in the medicated group. This suggests that natural ovulation is as effective as hormone therapy for preparing the uterus for embryo implantation.

However, an analysis of maternal complications during and after pregnancy revealed notable distinctions.

Women utilizing natural cycles exhibited a lower likelihood of preeclampsia, a severe condition marked by elevated blood pressure, along with fewer incidences of early pregnancy loss. They were also less prone to develop placenta accreta spectrum, a condition that makes the placenta difficult to detach following childbirth. Additionally, this group had reduced rates of cesarean sections and severe postnatal hemorrhage.

“These risks impact both maternal and fetal health during pregnancy and hold significance for long-term postpartum health,” states Wei.

“This research is vital,” notes Tim Child, Chair of the Scientific and Clinical Progress Advisory Committee of the UK Human Fertilization and Embryology Authority. The clinic now advises individuals with regular menstrual cycles that both natural and medicated methods yield similar success rates.

However, Child points out that there is evidence suggesting natural cycles may lower the risk of preeclampsia. This reduction may be attributed to the presence of the corpus luteum, which regulates hormones necessary for preparing the uterus for pregnancy.

“This extensive study corroborates and expands on previous findings, especially concerning significantly lower rates of preeclampsia, early miscarriage, placenta accreta, cesarean sections, and postpartum hemorrhage linked to the natural cycle approach,” Child asserts.

Wei’s team is set to analyze blood samples gathered during the trial to identify potential biomarkers that could shed light on the differences observed in pregnancy complications.

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Source: www.newscientist.com

Ancient Woolly Rhinoceros Genome Found in Frozen Wolf Pup’s Stomach Meat

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Woolly Rhinoceros - an ancient herbivore

Woolly Rhinoceros: Icon of the Last Ice Age

History Collection / Alamy

A recently reconstructed genome from a piece of flesh found in the stomach of a wolf pup, dated to 14,400 years ago, reveals that the woolly rhinoceros was genetically robust despite its close proximity to extinction.

While the exact cause of the young female wolf pup’s death, near present-day Tumato in northern Siberia, remains a mystery, it is believed she and her sister, referred to as Tumat puppies, had recently consumed woolly rhinoceros meat (Coelodonta antiquitatis). Their mother inadvertently caused their burial in permafrost when their burrow collapsed.

The first puppy was discovered on-site in 2011, with the second found in 2015. Examination of one puppy’s stomach contents revealed remnants of woolly rhino meat.

Edana Road, a member of the research team at Stockholm University, remarked that the preserved material resembled “fluffy jerky.”

“It was astonishing to see hair still intact,” Lord commented.

Lord stated that the preservation of the tissue was almost miraculous.

“It’s remarkable that, thousands of years later, we retrieved a beautifully preserved mummified wolf pup, analyzed its stomach contents, and uncovered this woolly rhinoceros tissue, shedding light on a previously different species,” Lord adds.

Tumat Wolf Pup: Evidence of Woolly Rhinoceros Diet

Mietje Germonpre

Lord’s team successfully reconstructed the woolly rhinoceros genome, identifying it as a female with no signs of inbreeding.

This groundbreaking finding is significant because it marks the first time DNA has been recovered from a woolly rhinoceros close to the time of its extinction.

The cause behind the woolly rhinoceros’ extinction remains a topic of debate, encompassing the impacts of human hunting, climate change, and inbreeding.

Another researcher on the team, Darren Love, noted that the sample’s hair was yellowish, leading to initial thoughts that it belonged to a cave lion carcass (Panthera spelaea) until DNA analysis was performed.

“As far as I know, sequencing an entire ancient genome from stomach contents has never been accomplished before,” Darren stated.

The research team compared the new genome with two others from the woolly rhinoceros, dating back 18,000 and 49,000 years, discovering no evolution in genetic diversity or inbreeding levels over time.

“Had populations dwindled, we would expect a drop in genetic diversity among woolly rhinoceroses, alongside an increase in inbreeding,” Darren explained.

The researchers concluded that the most probable driver behind the woolly rhinoceros extinction was a rapid climate shift between 14,700 and 12,900 years ago, during the Bølling-Allerød Interstadial, which drastically altered the species’ habitat.

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Source: www.newscientist.com

The Mystery of Earth’s Ancient Frozen Nuclei Unveiled: Discovering the Reasons Behind Their Existence

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We may finally understand what caused the inner core of the Earth to freeze.

The inner core is a sphere of iron approximately 2,400 km (1,500 miles) in diameter, enveloped by a molten outer core. Its growth is responsible for generating the Earth’s magnetic field, which shields the planet from harmful solar radiation. However, the precise process by which the core first crystallized has remained unclear.

Recent research published in Nature Communications suggests a mechanism that hinges on deep Earth chemistry. By utilizing advanced computer simulations, scientists examined how various factors influence the freezing of iron under extreme pressure and temperature at the planet’s center.

They found that incorporating carbon allows iron to solidify under realistic conditions, positioning it as a key component in understanding the ingredients that contributed to the formation of the inner core billions of years ago.

“By investigating how Earth’s inner core formed, we gain insights not only into the planet’s history,” said Dr. Alfred Wilson from the University of Leeds, who led the study.

“We get rare insights into the chemistry of a region that we can never physically reach, and we can only speculate on how it might change in the future.”

The inner core lies deep within the planet, beneath layers of rock and magma – Credit: Getty Images/EPS Vector

At the extreme pressures found 5,000 km beneath our feet, iron doesn’t simply freeze when it drops below its melting point; it requires “super-cooling” of the crystals before they form. Pure iron must be cooled to as low as 1,000°C (1832°F), resulting in a significantly larger core than the one we see today.

New computer modeling indicates that the presence of carbon alters this equation. With less than 4% carbon in the mix, iron can crystallize at much lower temperatures, producing a core that aligns with seismic observations.

Scientists believe that the Earth’s center likely continues to host a mixture of elements. However, this research firmly highlights the critical role of carbon in one of geology’s greatest mysteries.

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Source: www.sciencefocus.com

Frozen Evidence of Mars’ Turbulent Origins Found in Its Mantle, Study Indicates

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The mantle of Mars houses ancient fragments measuring up to 4 km in width from its formation, as revealed by an analysis of seismic data gathered by NASA’s InSight Mission.

The immense collisions during early Mars’ history resulted in a global ocean of magma. Image credit: Vadim Sadovski / Imperial College London.

The planet’s mantle serves as a significant layer, located between the crust and core, preserving vital evidence about its formation and evolution.

In contrast to Earth, where active plate tectonics constantly mix the mantle, Mars functions as a smaller planet with a single plate surface.

This results in considerably less mixing of the Martian mantle, which may retain records of early internal history, providing valuable insights into the formation and evolution of rocky worlds.

Utilizing data from NASA’s InSight Lander, Dr. Constantinos Charalambous from Imperial College London and his colleagues analyzed the seismic signatures of Marsquakes to better understand the composition of the Martian mantle.

They studied eight recorded quakes, including those triggered by the impact of meteorites, discovering that the arrival of high-frequency P-waves is consistently delayed as they traverse deeper regions of the mantle.

The authors suggest that these delays indicate variations in the composition of the mantle stretching over kilometers.

Given that Mars lacks plate tectonics and large-scale recycling processes, these minor irregularities are likely remnants of its formative history.

Investigating the heterogeneity of the Martian mantle implies that it results from an intense and destructive process, reflecting the significant events of the planet’s early history that caused extensive interior disruption and mixed both foreign and crustal materials at a planetary scale.

Furthermore, additional variations might have arisen from the vast ocean of crystallized magma formed during this aftermath.

Rather than being erased, these features were preserved as the Martian crust cooled and mantle convection ceased.

“The seismic signals displayed clear signs of interference while traveling deep within Mars,” Dr. Charalambous noted.

“This coincides with a mantle composed of structures originating from various compositions, representing Mars’ early remnants.”

“What occurred on Mars is that following these initial events, the surface hardened into a stagnant lid.”

“It became isolated from the mantle, entrapping ancient, chaotic features like planetary time capsules.”

“Our observations reveal the distribution of fractals, where energy from violent collisions exceeds an object’s strength.”

“This mirrors the effect seen when glass falls onto a tiled floor, akin to meteorite impacts with a planet. It results in the formation of both large and small fragments.”

“It’s astonishing that we can still detect this distribution today.”

“The Jet Propulsion Research Institute” stated Dr. Mark Panning, a researcher at NASA’s Jet Propulsion Laboratory.

“It’s exhilarating to witness scientists uncovering new findings through the earthquakes we observe!”

The team’s paper was published today in the journal Science.

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Constantinos Charalambous et al. 2025. Evidence of a highly uneven Mars mantle inferred from earthquake analysis. Science 389 (6763): 899-903; doi: 10.1126/science.adk4292

Source: www.sci.news

Discover How Frozen Microorganisms Survive for 100,000 Years

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Some archaea can endure extreme environments

Steve Gschmeissner/Science Photo Library

Microorganisms found in Siberian permafrost seem to have existed for more than 100,000 years as indicated by DNA analysis. The genetic similarities with other species imply that such long life spans might be common among the closest living relatives of complex cell organisms.

Additionally, microorganisms gathered from ancient marine sediments, some over 100 million years old, raise questions about the survival of individual organisms over such spans. “You can’t conduct experiments over that duration,” states Karen Lloyd from the University of Southern California. “[Time] Coexistence is an unpredictable variable.”

Lloyd and her team aimed to find microorganisms in areas that had been stable for extensive periods. Their exploration led them to the Chukchi Peninsula, the easternmost point of Siberia, where they extracted a 22-meter core of permafrost.

This core allowed them to extract DNA from layers of marine sediment that dates back between 100,000 and 120,000 years. These sediments contained pores filled with liquid water that might have trapped microorganisms, preventing any exchange of nutrients or organisms. “Being frozen means that ice structures encapsulate them,” Lloyd explains.

The subsequent question was how to differentiate between living and non-living cells. Researchers sequenced millions of DNA fragments from the permafrost, utilizing them to reconstruct the genomes of various microbial species present. The degraded DNA was repaired, and enzymes that facilitated genome reconstitution were introduced into the mix.

After incorporating DNA repair enzymes, most reconstructed genomes showed significant completeness, indicating they originated from dead cells that do not actively preserve DNA integrity, according to Lloyd. Conversely, the genomes of six species showed minimal alteration, suggesting that these DNA samples came from living cells actively maintaining their genome since being frozen at least 100,000 years ago.

All six species with intact DNA were from the gate forest, also known as Asgard Archaea. These organisms are recognized as the closest modern relatives to all eukaryotes, encompassing animals, plants, fungi, and other native forms of life.

“Discovering Asgard archaea thriving in ancient permafrost offers insight into their evolutionary path… and their role in the emergence of complex life,” remarks team member Rend Liang at the University of Earth Sciences in China, especially during an era when the Earth was fully frozen.

Even more remarkably, the long-lived species were similar to Asgard Archaea found in less extreme environments, sharing genes associated with protein and DNA repair. This may have facilitated gradual exchanges of cellular components in low-energy conditions without cell division. “They’re like the most uneventful Asgards ever,” Lloyd comments. “Their lack of excitement suggests they possess capabilities.”

Stephen de Hon from the University of Rhode Island considers the study a “significant advancement” in understanding exceptionally long life spans.

Nevertheless, he warns that these findings should not be generalized to environments beyond freezing conditions like permafrost. “Long periods of inactivity in frozen states are different from living extensively at minimal activity levels.”

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Source: www.newscientist.com

Can a surgeon successfully implant a kidney frozen for 10 days?

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On the last day of March, surgeons at Massachusetts General Hospital began surgery that they hoped would lead to lasting changes in the way the kidneys are implanted in people.

The patient that morning was not a human. It was a pig and was anesthetized on the table. The pig had one kidney missing and needed an implant.

Kidneys usually need to be transplanted within 24-36 hours, but the kidneys that enter the pig were removed 10 days before and frozen earlier that morning.

No one ever transplanted frozen organs into large animals. There were a lot of things that didn’t work out.

“I think there’s about a 50% chance that it will work,” said Kolkout Wygun, a surgical professor and team leader, before the surgery. Dr. Uygun is on the Scientific Advisory Committee of Sylvatica Biotech Inc., a company that develops freezing methods for organ maintenance.

But the promise from the organs of freezing and storage is fantastic.

There is a severe and continuous shortage of kidneys for transplants – That’s all 92,000 People are on the waiting list. One reason is that the 24-36 hour window is very short, so limit the number of recipients that are good matches.

How good is it to have a bank of stored frozen organs, as organ transplants can be like an elective surgery?

At least, it was a decades-long dream of a transplant surgeon.

However, the medical researchers’ attempts to freeze organs were thwarted at every turn. In many cases, ice crystals formed organs and destroyed them. The material was also intended to stop the crystals from forming, the anti-freeze agent was toxic and killed cells. Or the frozen organs became very brittle and cracked.

Source: www.nytimes.com

Just Dance Saves Christmas in the Face of Family Breakup and Frozen Wellington

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TAs my children grow up, it gets more challenging to involve them in Christmas and our old traditions. My youngest daughter, who was traveling, sent me a text from a nightclub in Bangkok with a photo and a comment about a spliff. My middle son went to be with his girlfriend on Boxing Day. My eldest daughter had to work a shift at the veterinary hospital on Christmas Day, so she was only available for a few hours. We had a small argument on the 23rd, which limited our communication.

Making Christmas memorable this year was tough. But I had a plan. And that plan was “Just Dance 2025.”

Initially hesitant to play arcade dance games, I was amazed to see someone showcasing their Dance Dance Revolution skills in London. This inspired me to set up Dancing Stage MegaMix on a PS2 at home. Despite neglecting my gym equipment, I focused on dancing on the mat daily and even perfected my moves on Cure’s The Love Cats in the mid-2000s.

For this year’s Christmas, I planned a leisurely breakfast, prepared Mushroom Wellington as a peace offering for my vegan daughter, woke up my son, exchanged gifts, surprised them with Just Dance, prepared dinner, and danced until late evening before taking my daughter home.

A snowstorm and multiple phone calls on Christmas Eve and Day added chaos to our plans. I had to make last-minute adjustments, like borrowing a truck to pick up my daughter, leading to a stressful situation akin to Nakatomi Plaza from Die Hard.

Despite the chaotic unwrapping of gifts, we managed to enjoy playing Just Dance as a family, even if dinner plans went awry. It was a tough decision to prioritize the game over dinner, but sometimes as a father, you have to make those tough calls.

However, technical difficulties arose with setting up the game, including the need for additional controllers and charging issues. Eventually, we managed to overcome these hurdles and have a memorable Christmas dance-off.

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Using our phones as controllers, we managed to play and enjoy Just Dance as a family. It brought us closer together and added a spark of joy to our Christmas celebration, despite the initial challenges.

By dancing to some classic tunes like Abba, we found a common ground and shared moments of laughter and fun. Just Dance truly saved our Christmas and created lasting memories for us to cherish.

Abba saved Christmas again. Photo: Alamy

Despite the challenges and chaos, we managed to find joy and connection through music and dance, reaffirming the true spirit of Christmas for our family.

Source: www.theguardian.com

First-ever examination of a frozen mummy of a Saber-toothed tiger dating back 35,000 years

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Attention all ‘Ice Age’ enthusiasts: New research has uncovered the preserved remains of a 35,000-year-old saber-toothed cat which have been analyzed for the very first time. Published on Thursday in Scientific Reports.

The mummified remains of the animal, including parts of the head, arms, and chest, were unearthed in Yakutia, Russia, in 2020 in remarkably good condition, and were determined to belong to a three-week-old baby, as per the study findings.

The most distinct features of the cub were its small ears, long neck and forearms, dark brown fur, and wide mouth, according to the researchers. Comparison with modern lion cubs of the same age suggests that these cat mummies are part of the Machairodontinae subfamily, specifically the Homotherium genus – a cat with sharply curved saber teeth that thrived in North America and Europe between 12 million and 10,000 years ago.

A. shows a frozen mummy and B. shows the remains of a modern lion cub, Panthera leo (Linnaeus, 1758).Lopatin, AV, Sotnikova, MV, Klimovsky, AI, and others

Based on the study, the Homotherium cat’s ears were positioned higher on the skull and its mouth opening was 11-19% larger compared to modern lion cubs. Additionally, the neck was described as “longer and more than twice as thick” than that of present-day felines.

For those who enjoy the Ice Age film series, the depiction of saber-toothed cats might seem familiar. The character Diego, a saber-toothed tiger, shares similarities with the 35,000-year-old baby tiger.

This study marks the first investigation of this kind of site.

“For the first time in paleontological history, the characteristics of an extinct mammal with no modern counterparts have been examined,” noted the study authors.

Attempts to reach the study’s corresponding author for comment were unsuccessful at the time of publication.

Source: www.nbcnews.com

Is it Necessary to Establish a Frozen Backup of Earth’s Life on the Moon?

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Shackleton Crater on the south pole of the moon is an area in permanent shadow

LROC/Shadowcam/NASA/KARI/ASU

A backup of Earth-based life could be safely stored in a permanently dark spot on the Moon’s surface, without the need for power or maintenance, and could potentially be restored if life becomes extinct.

Mary Hagedorn Researchers at the Smithsonian’s National Zoo and Conservation Biology Institute in Washington, DC, and their colleagues proposed building the lunar biorepository as a response to extinctions occurring on Earth.

The plan has three main goals: to protect the diversity of life on Earth, to preserve species that may be useful for space exploration, such as those that can provide food or biological materials for filtration, and to preserve microorganisms that may be needed in the future to terraform other planets.

Hagedorn said the team wanted to identify a place that wouldn’t require people or energy to store cryogenically frozen living cells at temperatures below minus 196 degrees Celsius, the temperature at which nitrogen becomes liquid and all biological processes stop.

“There’s no place on Earth cold enough to put passive storage, which has to be kept at minus 196 degrees Celsius, so we thought about space or the moon,” Hagedorn said.

She said the team chose the lunar south pole because of a deep crater with a cold area that’s permanently in shadow. Burying the samples about two meters below the surface would also protect them from radiation, she said.

Previous attempts to build safe biovaults have met with mixed success. The Svalbard Global Seed Vault in Norway is located in the Arctic and was built to be permanently kept at or below -18 degrees Celsius by the surrounding permafrost, but climate change and rising temperatures threaten its long-term safety.

Biorepository facilities in other parts of the world, especially those located close to cities, are human-power dependent and vulnerable to geopolitical upheaval.

Andrew Pask David B. Schneider, a researcher at the University of Melbourne in Australia who is building an Australian seed repository, is enthusiastic about the idea: “We want to look at the same samples in the same facility to ensure their safety, and at the moment the Moon seems like the safest place,” he says.

but Rachel Lapin A researcher from Monash University in Melbourne says there are many challenges and disadvantages to using the Moon, especially the difficulty of accessing it to add or remove samples. She says it might be better to store samples on Earth with lots of redundancy, so that if one repository fails, others are available.

“I want to see compelling evidence that storage will be available if needed,” she said.

Even if this moon vault is not used, Alice Gorman Researchers at Flinders University in Adelaide, Australia, see value in preserving human remains in space, and believe they might one day be accessible to extraterrestrial civilizations.

“Whether it’s cryogenically frozen biological tissue or DNA, or the full text of Wikipedia stored on a high-density nickel disk, the repository will be similar to the Voyager Golden Records,” Gorman says, referring to the metal disks containing humanity’s story attached to the spacecraft currently leaving the solar system.

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Source: www.newscientist.com