Tag: science

DIY electrophoresis

Well, what’s a narrow rigid tube that’s easy for anyone to acquire? A clear drinking straw! Paper clips make for appropriately sized electrodes, and since a drinking straw is rigid, it can be used in either the horizontal or the vertical orientation. For extra bonus points, when you’re ready to cut a band out of the gel, no need for mucking around with razor blades — just take a (sterile) pair of scissors, snip snip, and you’re done! Plus, disposal is extra simple, even with polyacrylamide — just dispose of the entire straw, gel and all, properly. Tito Jankowski tried this out, using a single 9V battery as a power supply, and after some debugging, it worked beautifully. (He also used alligator clips as electrodes, and they worked just fine.) We’re calling these “keiki gels” because they’re so small and cute — and so simple, even a little kid can do them. This is crowdsourced science at its very finest. Behold the power of collaboration!

DIY bioscience is real.

Henrietta Lacks

Every single one of the cell lines Gartler was investigating, and countless others being used around the world, had been contaminated by HeLa cells. They had taken over every Petri dish of cells they had come near.

2014-06-10: A bit more on HeLa contamination

As we have more cell lines to work with and as we’re able to learn more about the molecular specifics that identify those cell lines, people are starting to go back and re-evaluate old research.

Not only is it becoming clear that results have been skewed by the use of less-than-ideal cell lines, in many cases, the scientists weren’t even using the cell lines they thought they were using. Instead, mistakes in the laboratory meant that cell lines got mixed up with one another. A common problem: Tough, fast-growing cells finding their way into a dish of weaker-growing cells, where they quickly take over. The dish is labeled as being one thing, but the cells now growing there are totally different. HeLa, the line of cells derived from the cervical cancer tumor of an African American woman named Henrietta Lacks, are infamous for invading test tubes all over the world. “You don’t even need sloppy lab technique. All it takes is for a droplet of HeLa to fall into another culture. Then it’s survival of the fittest and HeLa is very fit.”

Graphene

Researchers have produced a ground-breaking new material, graphane, which has been derived from graphene. What is huge: 1. Graphene has already has a lot of great properties. Strongest material. Very conductive. 2. Now graphene can be chemically modified to tune the properties even more. Making something highly conductive and highly insulating means all kinds of electrical devices are possible 3. This is opening the door to even more chemical modification. 4. Graphene has already been turned into proof of concept liquid crystal display devices (single pixel) and quantum dots and transistors

Materials science rarely gets the respect it deserves. We really should all bow before these people. They make modern civilization.
2013-03-25: Graphene is nearly here.

A 10000 Farad Supercapacitor is powerful enough to power a Semi Truck while being the size of a paperback novel. Tesla promised to get the price of lithium batteries down to $150 / kWh by 2020, our current cost estimated for this type of graphene based supercapacitor is about $100 / kWh today and we should be able to cut this pricing in half by the end of 2015

2013-07-16: Graphene is one of my bets for most impactful technology of the 21th century.

A new form of Carbon : Grossly warped ‘nanographene’ : The new material consists of multiple identical pieces of “grossly warped graphene,” each containing exactly 80 carbon atoms joined together in a network of 26 rings, with 30 hydrogen atoms decorating the rim. Because they measure slightly more than a nanometer across, these individual molecules are referred to generically as “nanocarbons.”

Odd-membered-ring defects such as these not only distort the sheets of atoms away from planarity, they also alter the physical, optical, and electronic properties of the material.


2015-02-27: A kind of moore’s law for graphene. If you can convince enough of the industry that the roadmap is real, it becomes real due to all the investment it triggers

In an open-access paper published today in the Royal Society of Chemistry journal Nanoscale, more than 60 academics and industrialists lay out a science and technology roadmap for graphene, related 2-dimensional crystals, other 2d materials, and hybrid systems based on a combination of different 2d crystals and other nanomaterials.

The roadmap covers the next 10 years and beyond, intended to guide the research community and industry toward the development of products based on graphene and related materials.

2015-05-21:

The new roll-to-roll manufacturing process described by his team addresses the fact that for many proposed applications of graphene and other 2-D materials to be practical, “you’re going to need to make km2 of it, repeatedly and in a cost-effective manner.”

50cm / min is starting to get interesting.
2016-01-07:

Researchers found a way to incorporate carbon nanotubes and graphene into spider silk. “We measure a fracture strength up to 5.4 GPa, a Young’s modulus up to 47.8 GPa and a toughness modulus up to 2.1 GPa. This is the highest toughness modulus for a fiber, surpassing synthetic polymeric high performance fibres (e.g. Kelvar49) and even the current toughest knotted fibers.”

2017-06-10:

The use of graphene as an additive can give mechanical and electrical benefits to composite materials, making them multifunctional. In a novel fermentation method, Graphene Flagship researchers have developed graphene-containing rubber foams with unusual mechanical and electrical behaviors: when stretched, the composite foams expand and become more conductive. These unexpected properties could be promising for use in smart filters and medical devices.

Alliance Rubber intends to help determine exactly how this super-material could be used in its products. The partnership will explore potential uses for graphene-infused rubber bands for many other characteristics.

  • Graphene-rubber bands could act as bar codes for produce in grocery stores
  • Heat-sensitive bands which change color depending on the temperature.

2022-04-15:

Graphene and carbon nanotubes are undoubtedly the materials of the future. In their perfect form they are the strongest materials that are known to exist, with thermal conductivity among the highest of known materials, and even superconducting electrical properties. However, defects in the lattice structure cause significant decreases in these physical properties; and so quality and purity are of paramount importance. On top of this it is very difficult to make continuous sheets more than a couple of millimeters long, and even harder to wrangle this atomically thin layer into real-world applications. We recommend paying attention to companies that are developing methods to produce graphene and CNTs in larger sizes and for lower costs. And we will be tracking companies that show themselves to be successful at leveraging today’s low-quality graphene flakes to improve existing products, or to develop new capabilities for applying this material in novel ways.

2023-01-17: More C allotropes.

An allotrope is a substance with a defined structure that’s made up of only one element, but differs from another form of the same pure element. Graphite (familiar as pencil “lead”) is a famous allotrope of carbon, and it has the same infinite-stacked-sheets-of-atoms structure. Single isolated sheets, known as graphene, were (famously) isolated a few years ago, and these single-atom-thick are different enough that most people consider them a different allotrope than even graphite, which name is used for the bulk material. So what if you took a structure like graphene, the flat sheet of 6-membered rings, and made a flat sheet of buckyballs instead? That has now been prepared and named “graphullerene”.

Brain waves

“neuronal noise” may not be a nuisance at all, but instead the brain’s way of providing as comprehensive a statistical representation of the observable world as possible.

2018-11-15: Meditation’s effect in brain waves

What’s going on in the brains of people who meditate? Anecdotal evidence suggests that meditation does something to people’s minds and bodies…quiets and calms them. Davidson brought a number of “Olympic level meditators” into his lab and hooked them up to a brain scanner. He found that the brains of these expert meditators have different brain wave patterns than the rest of us.

2019-08-06: Ripples for memory

researchers have offered up proof that sharp wave ripples play a part in memory: Artificially prolonging the ripples in rats improved their performance

2019-08-12: Keeping the Brain’s Cells in Sync with Gamma Rhythm Synchronization

“It may make a lot of sense that gamma rhythms matter in the brain”. But rather than measuring that rhythm’s aggregate signal across the entire brain, neuroscientists might need to look at several signals, each one accounting for some smaller section of the brain. “You have to go down to the level of local groups of neurons to really see what they’re doing.”

2021-02-23: 1/f noise

The amplitudes for power spectra are usually plotted in logarithmic coordinates because of the wide range in their values. For purely random white noise, the power spectrum curve is relatively flat and horizontal, with a slope of zero, because it’s about the same at all frequencies. But neural data produces curves with a negative slope such that lower frequencies have higher amplitudes, and the intensity drops off exponentially for higher frequencies. This shape is called 1/f, referring to that inverse relationship between the frequency and the amplitude. Neuroscientists are interested in what the flatness or steepness of the slope might indicate about the brain’s inner workings.

2021-05-27: Brain synchronization sociality

Mr. Wu zapped the 2 mice at the same time and at the same rapid frequency — putting that portion of their brains quite literally in sync. Within 1 minute, any animus between the 2 creatures seemed to disappear, and they clung to each other like long-lost friends. “Those animals actually stayed together, and 1 animal was grooming the other”. If brain-to-brain synchrony does turn out to be a real driver of social interaction, it could have some meaningful applications for people who struggle with social anxiety disorders, for example. Several noninvasive techniques, like transcranial magnetic stimulation, can stimulate people’s brain activity and are being tested as treatments for a range of psychiatric disorders. “The human sociality spectrum is very broad, and there’s probably a subset of people who wouldn’t mind if it was possible to influence their level of sociality.”

2021-07-09: Phase precession

Along with rate, there’s also timing: As the rat passes through a place field, the associated place cell fires earlier and earlier with respect to the cycle of the background theta wave. As the rat crosses from 1 place field into another, the very early firing of the first place cell occurs close in time with the late firing of the next place cell. Their near-coincident firings cause the synapse, or connection, between them to strengthen, and this coupling of the place cells ingrains the rat’s trajectory into the brain. (Information seems to be encoded through the strengthening of synapses only when 2 neurons fire within 10s of milliseconds of each other.)

“It’s so prominent and prevalent in the rodent brain that it makes you want to assume it’s a generalizable mechanism”. Scientists had also identified phase precession in the spatial processing of bats and marmosets, but the pattern was elusive in humans until now. Studies suggest that phase precession allows the brain to link sequences of times, images and events in the same way as it does spatial positions. Phase Precession might facilitate very rapid learning of sequences, explaining why artificial neural networks train on 100s or 100s of examples of a pattern before the synapse strengths adjust enough for the network to learn, while humans can typically learn from just 1 or a handful of examples.

2023-02-04: Critical brain hypothesis

The brain is always teetering between 2 phases of activity: a random phase, where it is mostly inactive, and an ordered phase, where it is overactive and on the verge of a seizure. The hypothesis predicts that between these phases, at a sweet spot known as the critical point, the brain has a perfect balance of variety and structure and can produce the most complex and information-rich activity patterns. This state allows the brain to optimize multiple information processing tasks, from carrying out computations to transmitting and storing information, all at the same time.

Early critiques pointed out that proving a network was near the critical point required improved statistical tests. The field responded constructively, and this type of objection is rarely heard these days. More recently, some work has shown that what was previously considered a signature of criticality might also be the result of random processes. Researchers are still investigating that possibility, but many of them have already proposed new criteria for distinguishing between the apparent criticality of random noise and the true criticality of collective interactions among neurons.

Research in this area has steadily become more visible. The breadth of methods being used to assess it has also grown. The biggest questions now focus on how operating near the critical point affects cognition, and how external inputs can drive a network to move around the critical point. Ideas about criticality have also begun to spread beyond neuroscience. Citing some of the original papers on criticality in living neural networks, engineers have shown that self-organized networks of atomic switches can be made to operate near the critical point so that they compute many functions optimally. The deep learning community has also begun to study whether operating near the critical point improves artificial neural networks.