An iron artifact recovered by archaeologists may be the oldest of its kind ever found in Japan, according to new research.
Recovered during excavations at the Hayashi-Fujishima archaeological site in Fukui, the capital city of Fukui Prefecture, the artifact measures slightly more than an inch and a half across, just under an inch in width, and just a millimeter in thickness.
The presence of tiny, triangular teeth measuring up to 3 millimeters deep indicates the artifact’s use as an early saw, according to investigations by the Fukui Prefectural Archaeological Research Center, which recently announced the discovery.
While similar discoveries have been made in Japan, none are believed to be as old as this saw, which archaeologists have tentatively dated to the late Yayoi Pottery Culture Period, which thrived between the second and third centuries, making it the oldest known in the country.
Tomokatsu Uozu, Deputy Director at the Center, said the age of the discovery indicates the advancement of early iron technologies along the region’s coastal communities during the period.
“The artifact could be an important piece of evidence supporting the advancement of ironware culture along the Sea of Japan coast during the Yayoi period,” Uozu recently toldThe Asahi Shimbun.
Similar Discoveries in the Ancient East
The saw uncovered at the Hayashi-Fujishima archaeological site bears some similarities to saws from the same period that have been unearthed during past excavations in China.
Such similarities are important, since it is believed that the same iron processing techniques used in the creation of the saw from the Hayashi-Fujishima site originated in China, having been carried across the Korean Peninsula and eventually reaching northern Kyushu, where ancient traders carried it along the Sea of Japan to its eventual arrival at Fukui.
The saw recently showcased by the Fukui Prefectural Archaeological Research Center is only one example of the many artifacts recovered from the Hayashi-Fujishima site.
Identified Decades After Its Discovery
Past work at the site has uncovered additional iron artifacts, as well as stone tools, pottery, distinctive “magatama” and “kudatama” bead varieties, and a range of items during primary excavations, which were conducted during the late 1990s and early 2000s.
The site is believed to also host what remains of an ancient settlement dating to the Yayoi period, a period that was significant for the emergence of organized food production, as well as a unique element associated with the culture: the creation of distinctive, keyhole-shaped burial mounds.
However, it wasn’t until 2021, during restoration work with many of the artifacts retrieved from the site, that researchers first noticed something significant that had gone unnoticed decades earlier at the time of the artifact’s discovery: tiny serrations were present on one of its edges.
Further examination with the help of X-ray CT scan imaging confirmed the artifact’s identity as a triangular or “beak-shaped” saw, similar to other discoveries from later periods. At the time of its use, the complete saw would likely have measured up to five times the length of the remaining fragmentary portion.
Another notable feature of the saw is that the tip of the blade is bent, which archaeologists think may indicate that the saw was used for work involving fine crafting of wooden or stone items.
Breaking Earlier Records for Japan’s Oldest Saw
The discovery now overturns the previous oldest artifact of its kind known from the region, which was uncovered from a third-century burial mound in Hyogo Prefecture. That saw’s association with the Kofun Period, which thrived near the end of the third century, made it the oldest known at the time of its discovery.
Although additional studies are required, the team says that confirmation of the age of the Hayashi-Fujishima site’s saw would extend the timescales once again on the earliest use of such technologies by as much as a century.
A meteorite discovered in Africa could be evidence of a lost protoplanet that once orbited our Sun, according to researchers at the University of Colorado at Boulder.
In a recent paper published in Earth and Planetary Science Letters, the team revealed evidence of an ancient protoplanet that may have been as large as Mars based on simulations of how the meteorite sample may have formed.
The four-and-a-half-billion-year-old world carried an unexpected geological makeup, which the researchers say casts doubt on common assumptions regarding planetary evolution.
Protoplanetary Demise
According to the UC Boulder team, the massive protoplanetary body collided with another object four and a half billion years ago, shattering it completely. This is the first definitive evidence of a lost protoplanet in our solar system, based on analysis of the angrite meteorite NWA 12774, a shard of that planetary embryo recovered from the Sahara Desert.
“It’s incredible to think there was once a world this large,” said lead author Aaron Bell, an assistant research professor in the Department of Earth Science at CU Boulder. “We only know it existed because a few fragments of it happened to land on Earth. These meteorites preserved evidence of a completely different pathway through which early planets developed.”
A Rare Meteorite Sample
Angrites, a rare type of volcanic rock, serve as a record of our solar system’s distant past. These rocks began forming only a few million years after the solar system’s birth, making them valuable evidence of this early era. However, they are extremely rare and difficult to find.
NWA 12774 is one of only 68 angrite samples identified among more than 80,000 meteorites cataloged by scientists. Given its rarity, the discovery could potentially reshape how researchers understand these ancient rocks.
Until now, scientists had assumed that angrites originated from relatively small asteroids less than 124 miles (200 kilometers) wide, based largely on their chemical composition. Large rocky planets such as Earth and Mars contain significant amounts of silicon dioxide, while angrites contain very little of the compound.
Unexpected Meteorite Discovery
Researchers began to reconsider those assumptions when they identified clinopyroxene in the meteorite sample. This mineral, commonly found in Earth’s crust and mantle, appeared unusually rich in aluminum, suggesting that it formed under significant pressure deep within a planetary body.
To investigate this unusual characteristic of NWA 12774, the University of Colorado Boulder team recreated the conditions under which the sample could have formed. Their analysis revealed that pressures of at least 17.5 kilobars were required to produce the aluminum-rich clinopyroxene found in the meteorite. For comparison, one kilobar is roughly equivalent to the pressure at the deepest part of Earth’s oceans, near the bottom of the Mariana Trench.
Rethinking Meteorite Origins
The researchers’ discovery proved that at least this particular angrite sample could not have formed inside a small meteorite, as a body with a radius of at least 621 miles would be required to generate the pressure needed to produce the crystals.
Additional evidence suggested the parent body may have been even larger. The crystals’ sharp edges and delicate internal structures indicate they likely formed at relatively shallow depths beneath the surface. Reconciling both the high-pressure conditions and the shallow formation depth suggests that the parent body may have ranged in size from the Moon to Mars.
“There are many meteorites sitting in drawers that haven’t been thoroughly studied, so there were likely more of these protoplanets we don’t know about,” Bell said.
Exactly what happened to this ancient world remains uncertain, but researchers believe it was likely destroyed in a massive collision early in the solar system’s history. Fragments of that lost protoplanet may have later contributed material to other bodies, potentially including Earth itself.
“The materials that formed the angrite parent body are fundamentally different from the ingredients of Earth and Mars,” Bell concluded. “It points to a distinct and separate evolutionary path in planetary formation in the early history of our solar system.”
Ryan Whalen covers science and technology for The Debrief. He holds an MA in History and a Master of Library and Information Science with a certificate in Data Science. He can be contacted at ryan@thedebrief.org, and follow him on Twitter @mdntwvlf.
Scientists from ETH Zurich in Switzerland have announced a series of successful experiments involving the repair of injured spinal cords in zebrafish and mice after being injected with magnetically controlled microrobots containing pluripotent stem cells.
According to a statement announcing the ETH team’s work, both the zebrafish and mice injected with the microrobots showed improved movement and normalized exploratory behavior within just a few days after treatment.
Although the initial studies were confined to lab animals, the team hopes their magnetically controlled microrobot approach to the precision delivery of pluripotent stem cells could eventually be adapted for humans with spinal cord injuries.
Spinal Cord Repair Microrobots Treat Nerve Cells That Resist Regeneration
Unlike some cells in the human body, nerve cells within the spinal cord rarely regenerate on their own. If the spinal cord is injured, scarring can further reduce the ability of the nerve fibers within the cord to regrow. For people living with spinal cord injuries, this scenario can offer a bleak prognosis for recovery.
In recent decades, scientists have turned to the natural regenerative properties of pluripotent stem cells. Although the use of stem cells was initially controversial due to the need to extract neonatal stem cells, scientists ultimately learned to convert ordinary stem cells into pluripotent stem cells capable of becoming any cell type in the human body.
The most promising approach involves implanting stem cells at the site of the injury and then using electrical stimulation to promote the growth of new cells. However, according to the ETH team behind the new approach, the current method has several drawbacks.
First, stimulating the cells requires the use of implanted electrodes. Second, the team notes that after transplantation, many of the stem cells “do not always survive or integrate properly into the existing tissue.”
To improve healing and increase the chance of restoring spinal cord nerve cell function, they said their new approach combines therapeutic stem cells with magnetoelectric nanoparticles and uses magnetic fields to guide them to the “precise site of an injury” and “stimulate the stem cells to accelerate repair.”
NPCbots Combine Stem Cells and Magnetically Controlled Nanoparticles
To construct their magnetically guided spinal cord repairing robot, the team built what they termed a “biohybrid microrobot.”
First, the team creates pluripotent stem cells from adult cells by genetically manipulating them in the lab. The result is what researchers call an “induced” pluripotent stem cell (iPS). According to the study authors, these newly pluripotent iPS cells are used to derive living neural progenitor cells (NPCs), meaning “they have the potential to differentiate into various types of nervous system cells.”
Next, the team creates customized magnetic nanoparticles consisting of two layers. The inner layer responds to the “commands” from the magnetic fields used to control them, and an outer layer that converts this response into an electrical signal.
According to Professor Salvador Pané i Vidal of the Multi-Scale Robotics Lab at ETH Zurich, each tiny robot has a reservoir near the center “where we trap the cells.” The professor said the best way to accomplish this is to inject the nanoparticles into a solution with the NPC, “and wait for the two components to bind.”
After 30 minutes, the process is complete, and the team is left with a batch of nanobots, each around 6 micrometers in size. Since the new robots combine a magnetic bot and a reservoir of NPCs, the team named them ‘NPCbots.’
In preparatory cellular experiments, the researchers used hundreds of thousands of NPCbots. However, several million were required for animal trials.
Zebrafish and Mice Regain Movement After Injections
To test the efficacy of their new NPCbots, the ETH team injected millions of them into the spinal cord of zebrafish larvae with spinal cord injuries. To improve the chances of nerve regeneration, the NPCbots were injected directly into the site of the injury.
After injecting the microrobots, the injury site was subjected to electromagnetic fields. Although the repair was not immediately evident, the team noted that after three days, the zebrafish with the injured spinal cords “exhibited nearly normal swimming and exploratory behaviour.”
At the start and after three days: the top images show the uninjured spinal cord of a zebrafish; those in the middle show the injured spinal cord; and those at the bottom illustrate how the nerve cells grow thanks to the microrobots. Image Credit: ETH Zurich.
Next, the team injected millions of NPCbots into mice with completely separated spinal cords. According to the team, the results were “very promising.”
“After 28 days, the animals’ nerve cells had reconnected at the site of the injury,” they explained.
The team said further observation of the treated mice revealed “increasingly normal movement patterns,” including improvements in gait, stride length, and coordination. The ETH team also noted that the mice’s exploratory behavior “improved significantly.”
Schematic illustration of nerve cell recovery in zebrafish and mice. Image Credit: ETH Zurich.
When discussing the mouse experiments, the team described the result as “particularly significant” because zebrafish spinal cords regenerate, whereas mouse spinal cords do not. They also noted that the treatment was “well tolerated by the animals,” with no reported immune reactions or adverse effects.
Minimally Invasive and More Precise Treatments with Microbots
Unlike science fiction movies, where tiny robots repair tissue mechanically, the research team said that the stem cells carried by the NPCbots are exposed to electrical stimulation, “greatly enhancing their differentiation after transplantation.” This means the nanoparticles convert the electric signals from the EM field into electrical impulses, stimulating healing.
Unlike more complicated stem cell procedures that use implanted electrodes and cables, the team said they only needed to apply external magnetic fields around the spinal cord injury site. The team said this simplification was “crucial,” since the spinal cord is considered extremely sensitive. They also note that the ability to manipulate the frequency and field strength of magnetic fields, combined with their ability to penetrate deeply into tissue, makes the entire process safe and easy to control.
“Microrobotic guidance makes the treatment more precise and minimally invasive,” Hao explained.
After the NPC bots have delivered and stimulated the stem cells, the team said they “essentially dissolve” within the tissue. Because the bots contain a barium titanate coating, the researchers also believe that they will be “stable and minimally reactive” with surrounding tissue. Still, they concede that “further studies will determine whether and how the particles are degraded or excreted over the long term.”
Expanding NPCbot Therapies to Increase the Effectiveness of Other Targeted Therapies
Although the team described the animal trials of their NPCbots as “promising,” they noted that further research is needed before the process can be attempted on human patients with spinal cord injuries. For example, Hao noted that in addition to ‘clinical aspects’ that require more exploration, the team needs to start by determining which magnetic fields “work best in humans” and determining the “optimal stimulation duration” for human NPCs. Nevertheless, the team noted, they are “already considering further applications.”
“The reproducible and scalable production of microrobots using our lab-on-a-chip system demonstrates that the platform’s application potential extends beyond basic research,” Professor Vidal explained.
Some potential biomedical applications mentioned by the RETH team include cardiology, oncology, wound healing, “and other targeted therapies,” adding that their process could make such treatments “safer, more controllable and more effective.”
Christopher Plain is a Science Fiction and Fantasy novelist and Head Science Writer at The Debrief. Follow and connect with him on X, learn about his books at plainfiction.com, or email him directly at christopher@thedebrief.org.
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