News:

Next-generation spinal implants help people with severe paralysis walk, cycle, and swim | Science.Org (01:40)

• When trauma severely damages the bundle of nerves that make up a person’s spinal cord, the brain’s electrical signals no longer reach the body’s muscles, resulting in paralysis.
• This epidural stimulation device, a thin sheet of electrodes implanted beneath the vertebra of the lower spine, can recreate electrical signals beyond the injury site and trigger leg movements.
• To trigger leg and torso movements, researchers need to stimulate the dorsal roots, pairs of thick sensory fibers extending from either side of the spinal cord.
  • Existing electrode strips are too short to reach the dorsal root
• Researchers at Swiss Federal Institute of Technology designed a longer and wider implant, roughly the size of a pointer finger.
  • Electrodes positioned to precisely stimulate the dorsal roots
  • Used computer models to predict the ideal position of the implant on each patient’s spinal cord.
• Finally, the team designed software to activate the electrodes in set patterns that produce movements such as standing up and stepping. 
  • Might help retrain damaged networks of nerves in the spinal cord to better receive and interpret signals
• With the new electrode design, 3 men paralyzed in motorcycle accidents have become the first success stories for a new spinal stimulation device that could enable faster and easier recoveries than its predecessors.
  • Able to take supported steps within 1 day of turning on the electrical stimulation
  • After 4 to 6 months, all three participants were able to walk across the ground using only a walker for stability.
• Megan Gill, a research physical therapist at the Mayo Clinic not involved in the study, mentioned that the results are “remarkable to see within 1 day with a severe injury like this.”
• Using different stimulation patterns, the participants in the new study could swim, cycle, and do leg presses and sitting forward bends. One patient was even able to climb a staircase. 
  • With the stimulation off, their abilities remain limited.
  • One regained some ability to activate leg muscles, but not to make functional movements.
  • Two participants in a previous study who had incomplete paralysis could eventually stand without stimulation.
• For now, sending commands to the device is cumbersome. 
  • Select their desired movement on a tablet
• The next generation of devices would allow users to activate the pulse generator by giving voice commands to a smartwatch.
• In 2024, the company plans to test this newer mobility system in a multisite clinical trial of 70 to 100 participants that the team hopes will lead to U.S. regulatory approval.

New Synthetic Tooth Enamel Is Harder and Stronger Than the Real Thing | SciTechDaily (09:05)

• In a new study in Science, researchers present an engineered analog of tooth enamel designed to closely mimic the composition and structure of biological teeth’s hard mineralized outer layer.
• Natural tooth enamel – the thin outer layer of our teeth
  • The hardest biological material in the human body despite being only several millimeters thick.
  • High stiffness, hardness, viscoelasticity, strength, and toughness and exhibits exceptional damage resistance.
• Tooth enamel’s architecture:
  •  A complex structure made up of mostly hydroxyapatite nanowires interconnected by an amorphous intergranular phase (AIP) consisting of magnesium-substituted amorphous calcium phosphate.
• Accurately replicating this type of hierarchical organization in a scalable abiotic composite has remained a challenge.
• But here come the scientists creating an artificial tooth enamel (ATE).
  • Produced using AIP-coated hydroxyapatite nanowires, which were aligned using dual-directional freezing in the presence of polyvinyl alcohol. 
  • Have an atomic, nanoscale, and microscale organization like natural enamel.
• The ATE exhibited high stiffness, hardness, strength, viscoelasticity, and toughness, exceeding both the properties of enamel and previously manufactured materials. 

We Just Got Closer to Finding a Link Between Alzheimer’s And Circadian Rhythms | Science Alert (14:16)

• Scientists have uncovered a possible mechanism linking disruptions in circadian rhythms and the build-up of proteins associated with Alzheimer’s disease.
  • Studying the rhythmic operation of immune cells and the timers that control them
• Circadian rhythms are the daily rhythms of bodily functions which are tied to our natural body clock, respond to light exposure, and govern our sleep-wake cycles.
  • Poor sleep habits can throw circadian rhythms out of whack, which results in less time for immune cells to cleanse the brain of waste products that build up throughout the day. 
• Sleep disturbances starting years before any symptoms emerge have been linked to a greater risk of developing Alzheimer’s disease.
  • But, making a direct connection between circadian rhythms and the activity of immune cells tasked with cleaning up amyloid proteins has eluded scientists thus far.
• Remember, over time, clumps of misfolded protein (i.e. amyloid proteins) accumulate in the brain, which is thought to cause Alzheimer’s disease.
• In this new study, researchers at Rensselaer Polytechnic Institute studied immune cells called macrophages. 
  • Macrophages are scavengers that gobble up waste products, faulty proteins, and defunct cells to prevent toxic damage.
• In lab-grown cell cultures observed under a microscope, immune cells – derived from genetically modified mice with altered circadian clocks – went about cleaning up fluorescently-tagged amyloid-beta proteins on a daily cycle.
  • Promptly lost their rhythm when their circadian clock was disturbed indicating that fall under circadian control
• The researchers write in their paper, “These data highlight that circadian regulation in immune cells may play a role in the intricate relationship between the circadian clock and Alzheimer’s disease.”
• Whether circadian clock disruptions are a causative factor or physiological consequence of Alzheimer’s disease is still unclear, though.
  • It’s worth remembering, too, that amyloid proteins are not the whole story in Alzheimer’s disease. Could be a latecomer to the disease rather than an early trigger.
• That said, pinpointing a possible mechanism that goes some way to explaining how disruptions in circadian rhythms may perturb the clearance of amyloid proteins in the brain is a good step.
• Understanding the circadian timing of immune cells may also have implications for other disorders that like Alzheimer’s disease are linked to inflammation, including depression.

Microsoft Mitigates 3.47Tbps DDoS Attack, a New Record | PCMag (21:29)

• Microsoft says it encountered the largest DDoS attack on record last November when a hacker tried to take down a customer’s online services.
  • Involved an unnamed customer in Asia, who uses Microsoft’s Azure cloud computing service. 
  • The hacker harnessed 10,000 computers across the globe, including in the US and China, to generate a massive 3.47Tbps DDoS attack, which lasted for 15 minutes. 
• This attack exceeds the 2.5Tbps assault Google fended off in 2017, which was the previous record holder for largest known DDoS attack. 
• In December, Microsoft also mitigated a series of other DDoS attacks targeting customers in Asia. 
  • The first peaked at 3.25Tbps, the second at 2.55Tbps.
• The company wrote in a report about Azure and DDos attacks:
  • “In these cases, our customers do not have to worry about how to protect their workloads in Azure … Azure’s DDoS protection platform, built on distributed DDoS detection and mitigation pipelines, can scale enormously to absorb the highest volume of DDoS attacks, providing our customers the level of protection they need.”
• The incident shows even the largest DDoS attacks can be foiled through protection services from the biggest cloud providers. 
  • Cloudflare and Amazon, have also touted fending off major DDoS assaults in recent years with relative ease. 

Major breakthrough on nuclear fusion energy | BBC News (25:24)

• The UK-based JET laboratory has smashed its own world record for the amount of energy it can extract by squeezing together two forms of hydrogen.
  • JET is a sort of proof-of-concept for ITER at a smaller scale, discussed in Episode 50.
  • For the past 10 years, it has been configured to replicate the anticipated ITER set-up.
• The experiments produced 59 megajoules of energy over five seconds (11 megawatts of power).
  • More than double what was achieved in similar tests back in 1997. 
  • It’s not a massive energy output – only enough to boil about 60 kettles’ worth of water. 
  • But it validates design choices that have been made for an even bigger fusion reactor now being constructed in France (ITER).
• Dr Joe Milnes, the head of operations at the reactor lab, stated:
  • “The JET experiments put us a step closer to fusion power … We’ve demonstrated that we can create a mini star inside of our machine and hold it there for five seconds and get high performance, which really takes us into a new realm.”
• Dr Arthur Turrell, the author of The Star Builders: Nuclear Fusion And The Race To Power The Planet, commented on the results as well:
  • “This is a stunning result because they managed to demonstrate the greatest amount of energy output from the fusion reactions of any device in history … It’s a landmark because they demonstrated stability of the plasma over five seconds. That doesn’t sound very long, but on a nuclear timescale, it’s a very, very long time indeed. And it’s very easy then to go from five seconds to five minutes, or five hours, or even longer.”
• JET can’t actually run any longer because its copper electromagnets get too hot. For ITER, internally cooled superconducting magnets will be used.
• The big drawback with fusion is the amount of energy needed to put in. For example, at JET it utilizes two 500 megawatt flywheels to run the experiments.
  • ITER’s doughnut-shaped vessel volume will be 10 times that of JET. It’s hoped the French lab will get to breakeven. 
• JET is likely to be decommissioned after 2023 with ITER beginning plasma experiments in 2025, or soon after.