Batteries that get better with use
One thing you can be sure of seeing with great frequency in science journals is improved battery architectures. Because this falls under the category of A Very Big Deal That Is Going To Make Someone Very Rich. Most AVBDTIGTMSVRs aren’t so obvious before they’re discovered. Scientists work up some new trick, and it turns out to be just the piece that was wanting to fill in a gap for practical editing of genes, or creating a new class of drugs, or making the next generation of computer chips. But with batteries, the need for something better is always out there.
Better means of energy storage is an issue that hits at every level — from the tiny batteries in medical devices that go inside the body, to massive blocks of electrical storage like the one that Elon Musk just completed in Australia. In every case, being able to store more energy in a smaller space would be a tremendous advance.
The batteries that are in almost everything these days are lithium-ion based. They meet the standard for most things you want in a battery — they’re rechargeable a high number of times, they don’t demonstrate much of a “memory effect” (that business where a battery that’s stopped from charging when less than fully charged refuses to fully charge again), their manufacture is relatively simple, and they have a high energy density. But it’s that last thing that’s the issue. Lithium ion batteries have a high energy density relative to other common consumer batteries, but this is a case where more would definitely be better. Higher density batteries would enable everything from electric vehicles that go further, to electrical storage that makes it safer to use renewables for base load.
So … this week’s bid to improve batteries comes from a team of University of California Riverside who turn to pairing lithium with two elements that are common in better battery proposals: sulfur and silicon. Though these two look like a winning combination on paper, they’ve proved to be less tractable in practice. Sulfur cathodes tend to degrade rapidly once lithium is involved. Silicon anodes have a bad habit of simply shattering — because they swell. A lot. So lots of test systems have been made that successully show off one end of the battery or the other, but not both.
What the Riverside team achieves is a complete cell that gradually integrates lithium into the silicon and sulfur components with each power cycle. After 250 charge / discharge cycles, the system reaches an energy density of 350 Wh/kg — which is a significant advance over the 130 Wh/kg in high-end lithium ion cells on the market.
Only, as with almost every other battery proposal that comes through the journals, don’t expect to see this one sitting under a copper-colored cap anytime soon. A better battery doesn’t just have to store more energy, it has to do so safely, and it has to be something that can be manufactured in quantity at a reasonable cost. This week’s research suggests some ways that such problems could be addressed … but it’s not there yet.
So come on in. Let’s read some more research.
You have to love it when something’s official name includes the word “anomalous”
Every week there seems to be at least one article that starts along a path of “oh, I think I understand that well enough to explain it” only to find that the course leads to a small door, makes an abrupt left turn, then drops down a rabbit hole of inexplicable physics.
The only thing that can redeem such a moment is the somehow reassuring discovery that no one else understands it either.
This week’s moment comes with an examination of the Anomalous Hall Effect. The Hall Effect has to do with how an electrical current behaves in the presence of a magnetic field — and really, I’m not going to try and get any closer than that. The anomalous Hall Effect is kind of an extra effect that comes from … from … anomalies. It has to do with the paramagnetic properties of the material involved (see how I tossed the word “paramagnetic” in there without bothering to explain it? That’s because that would also launch several hundred words that would include at least one or two other terms that also needed explanation — it’s that kind of thing). This effect can actually be bigger than the ordinary Hall effect. It’s weird, it’s poorly understood, and it has pieces.
But wait. Just let me toss in part of the abstract for this article.
We propose a new theory of the topological Hall effect (THE) in systems with non-collinear magnetization textures such as magnetic skyrmions. We solve the problem of electron scattering on a magnetic skyrmion exactly, for an arbitrary strength of exchange interaction and the skyrmion size. We report the existence of different regimes of THE and resolve the apparent contradiction between the adiabatic Berry phase theoretical approach and the perturbation theory for THE.
That, my friends, is language that someone from Star Trek should be copying right now. “Captain, I believe we can solve the problem of electron scatttering using magnetic skyrmions.”
No. I am absolutely no closer to understanding what that means. I have this kind of brain-failure every week. I usually just don’t trot it out here where you can see it.
Why one particular kind of pesticide may be good for bees
I keep bees. I haven’t so far gotten a single ounce of honey from the bees. In fact, our deal works the other way around — I bring them gallons of sickly-sweet bee food and pollen blocks because I worry that they need to store up more honey for the winter. I just like having them around. In fact, I’m setting up another hive for the spring (Don’t tell my son, because I’m giving him the new hive — which I will set up, maintain, and stare at frequently — for Christmas).
Like everyone else on the planet, I’m deeply concerned about why so many bee colonies have failed in recent years. There are a lot of theories going around, from bee diseases to classes of pesticides that have become all too common in their use. One of those classes of pesticides is called pyrethroids. Pyrethroids are very widely used. If you’ve called for termite control lately, the treatment was probably a pyrethroids. If you grabbed for a can of stuff to chase off wasps — pyrethroids. Most of the stuff sold to spray for your garden pests either is, or contains, pyrethroids.
And pyrethroids kill the hell out of bees. But there is one particular version of these pesticides — tau-fluvalinate — that doesn’t kill bees, and a group primarily from the University of Michigan set out to figure out why.
The mechanism underlying bumblebee resistance to tau-fluvalinate remains elusive. Using mutagenesis, computer modeling of pyrethroid-receptor sites, and phylogenetic clues of sodium channel sequences, we uncovered bee-specific sodium channel residues that underlie species-specific pyrethroid selectivity. This finding could spur future development of a new generation of safer pyrethroids that selectively target pests, but not beneficial species.
That “sodium channel” thing in there is the key. Voltage-gated sodium channels open cell membranes to allow ions to pass through. They are critical to every-frickin’-thing that life does. Failures of specific sodium gates in humans can cause seizures, more seizures, pain, lots of pain, and also seizures. And pain. Often followed real quickly by death.
Which suggests that a chemical like a pyrethroid, which hits voltage-gated sodium channels in insects, probably hurts like hell before it kills them. Which may even make you think twice about blasting the stuff toward that hornet’s nest you accidentally knocked from a tree. Or maybe not.
In any case, the team here has an improved model for why this particular pyrethroid doesn’t harm bees, which could help develop other classes of pesticides that are also bee-friendly. Which would be great, because pyrethroids that are bee safe still kill varroa mites — which are a disaster in bee hives.
Unless you’re an amoeba, that quest for immortality may be futile.
The idea that we might one day, even one day soon, come to terms with aging in a way that allows us to pop a live forever pill is tantalizing. Not only are there plenty of pseudo-science pills already lining the shelves at your local “health food” store that promise something just short of reverse aging, the media constantly seems to promote something that’s going to refresh your muscles, tighten up your telomeres, and keep you ticking forever.
But a pair of authors from the University of Arizona want you to know that if you want to live forever, your best bet is … be a bacteria. Or one of those elegant little Parameciums. Because having more than one cell, is a ticket to Deathsville.
Our model shows that aging is a fundamental feature of multicellular life. Current understanding of the evolution of aging holds that aging is due to the weakness of selection to remove alleles that increase mortality only late in life. Our model, while fully compatible with current theory, makes a stronger statement: Multicellular organisms would age even if selection were perfect. These results inform how we think about the evolution of aging and the role of intercellular competition in senescence and cancer.
Here’s how this works. Don’t think of you as you. Think of yourself as … an environment. You … are the Serengeti Plain. On that plain graze millions — billions — of muscle cells and nerve cells and so on. Each one of those cells contains its own little genetic packet, putting it in competition with other cells out to occupy it’s ecological niche in your colon or retina. Some of what benefits these cells may help the community as a whole, but ultimately some members of these wandering herds develop a means of reproducing better than their neighbors (hey look, cancer) or come up with resource strategies that otherwise damage the whole organism.
Congratualtions. You’re not getting older. It’s just that your cells are becoming more highly evolved.
Stone Age women could beat the #$%@ out of you.
This one you’ve probably seen in the popular press. An international team from Canada, the UK, and Austria looked at the arm bones of women back to about 5300 BCE and compared them to the arms of modern women, including modern athletes.
Humeral rigidity exceeded that of living athletes for the first ~5500 years of farming, with loading intensity biased heavily toward the upper limb. Interlimb strength proportions among Neolithic, Bronze Age, and Iron Age women were most similar to those of living semi-elite rowers.
What the evidence suggests is that men across these periods were doing some pretty varied work — the thickness of their bones ranges widely. They were obviously covering a lot of ground very regularly, as their leg bones have a similar thickness to those of modern cross-country runners. But their arms aren’t always a lot bigger than today’s keyboard jockey.
But women were working. Hard. For thousands of years. At the sort of difficult, repetitive tasks that were really tough on the arms. If you’ve ever visited a prehistoric site in either the Americas or Europe and seen how much of the space was dedicated to some version of “crushing grain into flour by hand,” you probably have a good idea what much of that work entailed.
Upper limb bone mechanical properties were initially variable and right-lateralized in the Neolithic period among these Central European women and became highly symmetrical and homogeneous in the Bronze Age, a change that was attributed to the increasing predominance of bimanual cereal processing using saddle querns in the region
For prehistoric women in Europe, life was really a grind. (Thanks, I’m here all week. Literally.)
Canola oil may be a poor replacement for other oils.
This comes with all the same warnings that any basic research on food stuffs do — primary research, mouse-model is a long way from perfect, all that jazz. But with that said …
In recent years consumption of canola oil has increased due to lower cost compared with olive oil and the perception that it shares its health benefits. …
At this time point we found that chronic exposure to the canola-rich diet resulted in a significant increase in body weight and impairments in their working memory together with decrease levels of post-synaptic density protein-95, a marker of synaptic integrity, and an increase in the ratio of insoluble Aβ 42/40.
If you read that as “canola oil makes you fat and stupid” … that’s not quite right. Based on this study, canola oil makes mice fat and stupid. It’s a long way from definitive proof on people.
But spring for the olive oil, dammit.
Narwhals don’t have a flight or fight response — they have a freeze and flee response.
They may be the unicorns of the sea, but their screwed up response to threats is getting them killed.
When confronted with a human threat, most animals either freeze or flee — but the narwhal does a mixture of both, say the authors of a study in Science. This paradoxical response could make the toothed whales particularly vulnerable to the expansion of human activity in their Arctic habitat.
Some of the same systems that help narwhals survive in extreme environments around, and even under, Arctic ice, makes them uniquely easy to pick off by humans and also subject to simply exhausting themselves in attempts to get away from ships and other human activity now invading the less-frozen North.
Just another reason to not send fleets of ships across the North Pole, and there were already plenty of those.
Glue to stop eye leaks
Suppose something punctures your eyeball. … Okay, now that you’ve stopped screaming, you’ll be happy to know that a team from the University of Southern California has whipped up a glue that can seal eyeball openings before all that … stuff inside your eyeball … squirts … Aaargh!
Traumatic eye injuries require rapid treatment to prevent deterioration of vision. As an alternative to suturing or adhesives, Bayat and colleagues developed a temperature-responsive synthetic hydrogel that acts as a temporary sealant. Testing the hydrogel in a model of open globe injury in rabbits showed that the sealant was easily deployed from a custom-designed temperature-controlled syringe device and preserved intraocular pressure without evidence of chronic inflammation or toxicity. After gelation, the sealant could be removed by exposure to cold water. In combat or low-resource settings, this hydrogel could close wounds temporarily to prevent further tissue damage or vision loss before surgery.
Good. That’s good.
The heartland of super staph
Not so long ago, the word Staphylococcus wasn’t greeted by thoughts of a leg, face, and life-eating infection that was immune to even the latest arsenal of antibiotics. But while “killer staph” has only been circulating US hospitals for about two decades, a large international team tracked the beast to its home and found that this variant has been around a lot longer than you might think.
We show that USA300 evolved from a less virulent and less resistant ancestor circulating in Central Europe around 160 years ago. Constant surveillance of pathogen transmission routes is vital to prevent and control potential outbreaks. Whole genome sequencing proved to be a useful tool for epidemiological surveillance.
Unfortunately, quite small changes in the genome can alter both the virulence of a disease and how it responds to drugs. USA300 picked up the worst possible combo — a change that not only makes it immune to most treatments, but also a genuine flesh-consuming monster.
Want a larger version of this week’s infographic? Get it here.