Biocatalytic biobots brew beer better (Chemistry World)

1 minute read

Beer-brewing ‘biobots’ could boost the drinks industry by speeding up fermentation. Researchers in Czechia encapsulated yeast and iron oxide nanoparticles in a biocompatible polymer to create self-propelling biobots, which can be retrieved from beer samples magnetically – eliminating the need for filtration steps.

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Orange climbers make fluorescent blue molecules (Chemistry World)

1 minute read

Two coumarin compounds with nearly identical structures but contrary fluorescent properties have been isolated from the orange climber plant. One may find use in biomedical imaging due to its unconventional behaviour when aggregated in solutions.

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NMR reveals sialic acid biosynthesis in real time (Chemistry World)

3 minute read

A new analytical method has enabled continuous real-time monitoring of the biosynthesis of sialic acid, an important component of cell surfaces, via NMR. Described as a magnifying glass by lead researcher Christian Hackenberger from the Leibniz Research Institute for Molecular Pharmacology in Germany, the NMR technique allowed them to observe individual enzymatic steps and, for the first time, directly measure their conversion velocities in situ.

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Ancient microbial natural products reconstructed from Neanderthal dental plaques (Chemistry World)

2 minute read

Using dental calculus from Neanderthals and Palaeolithic humans, researchers have reconstructed ancient microbial genes and engineered modern bacteria to produce their previously unknown metabolites. The approach will allow natural product researchers to ‘add a new dimension and go back in time’ according to bioorganic chemist Pierre Stallforth from the Hans Knöll Institute in Jena, Germany, who led the project.

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Generic Drugs and Ambivalent Attitudes (McGill OSS)

4 minute read

Generic drugs offer low-cost alternatives to brand-name drugs and account for over ¾ of the prescriptions filled in Canada. Despite this, many people have lingering doubts, fears or negative perceptions of generic equivalents. Why?

According to Health Canada, a “generic drug is pharmaceutically equivalent to the brand name drug: it contains the identical medicinal ingredients, in the same amounts and in a similar dosage form. Generic medications may have different non-medicinal ingredients than the brand name drug, but the company must show that these do not affect the safety, efficacy, or quality of the drug compared to the brand name drug.”

Simply put, in all the ways that count, generic drugs are the same as name-brand options but cost significantly less. Assuming a generic version of their medication is available, why would a consumer choose the pricier option?

According to various surveys and studies, there are a few reasons. A big one is brand trust. Just as some people favour Ford vehicles or Apple computers, pharmaceutical companies have brand recognition and inspire brand loyalty. Whether conscious or unconscious, warranted or not, due to branding, experience or something ephemeral, patients often express a preference for specific brand names.

This ties in with another fairly major factor, how long a drug has been around. Several studies have shown that consumers prefer older drugs, even when newer drugs are equally safe and efficacious. In most countries, generic versions of a pharmaceutical aren’t approved by regulatory authorities until the original manufacturer’s patent protection has worn off. Typically, this amounts to somewhere between 8 and 15 years. In Canada, the US and the UK, drug patents are 20 years in length. However, the time taken to test drugs and get them approved for sale eats into this monopoly period, meaning that by the time a new drug gets to market, a generic version is typically about a decade away.

Even though generic drugs are pharmaceutically equivalent to their name-brand counterparts, they still undergo rigorous safety testing. Nonetheless, the perceived age of the name-brand option can influence how patients feel about the generic choice. A 2020 study found that “although there is a small segment of the population that chooses the newer option, believing it to be of greater efficacy, most consumers believe that an older drug is both safer and more efficacious.” Even when participants were given a “no preference” option, more than half still opted for the older medication. The researchers found a “consistent pattern in which, on average, participants thought that older products were both more effective and safer, even when they were clearly informed (and they know they were informed) otherwise.” Essentially, consumers’ goodwill and trust in a drug seem to grow with age.

Another element of this situation is revealed by a 2020 study that found patients more willing to choose generic drugs for conditions perceived to be less serious, like the flu, compared to those considered more serious, like a cardiac disease. This only further implicated the perception of efficacy and safety in why people choose name brands over generic ones.

This apparent trust of age is echoed in the findings of a 2022 study that found COVID-19 mRNA vaccines judged as safer and more effective when perceived to be older. By changing the events and discoveries shown on a timeline, researchers were able to influence how old participants perceived mRNA vaccines to be. They found that “accounting for participants’ vaccination status, Covid-19 mRNA vaccines received more support – they were judged as better, safer, and more as something people ought to take – when the technology undergirding their development was perceived as having longer existence.”

(a) Old timeline – manipulation stimuli, (b) new timeline – manipulation stimuli.

Image source:

Perhaps the most changeable factor in consumers choosing brand name is also one of the most predictable: education. When patients are sufficiently informed on the realities of generic drugs, the reasons not to pick them mostly evaporate. For the vast majority of people in the vast majority of situations, generic drugs offer a cheaper choice with no drawbacks. A 2016 survey found that roughly 1/3 of participants did not fully understand why both generic and name-brand drugs existed, and this comprehension was not affected by education level.

While the landscape is generally shifting towards a positive attitude towards generic drugs, work remains to be done to get the message across fully. If in doubt, ask your doctor if generic versions of your drugs are right for you. You could get a positive surprise on your next pharmacy bill!

This article was written for the McGill Office of Science and Society. View the original here:

Should you add milk to tea, or tea to milk? (McGill OSS)

2 minute read

Everyone seems to have an opinion on making the best cup of tea. People who have weighed in on this topic range from royal butlers to George Orwell, but despite many claims of it being definitively settled—often by science—the debate rages on.

From the ideal water temperature to the source of the tea leaves, the best material for a pot (china, earthenware, or pewter, according to Orwell, never silver!), the best shape of a cup, or whether it is sacrilege to add sugar, there are a lot of variables in brewing tea. However, one of the most hotly contested ones is not whether to add milk or not, but in what order.

Adding milk to tea has a few benefits, according to the experts. It can help counteract the tannin’s astringent or bitter aspects and adds a few calories and nutrients to an otherwise nutritionally bereft beverage. Modern research also shows that adding milk can decrease the staining effects of tea on teeth and, presumably, mugs and pots as well.

A commonly circulated theory posits that first pouring milk into a china teacup helps avoid the heat shock of directly filling it with hot fresh tea and stops low-quality china from cracking. Some sources claim that the practice of pouring tea into a cup before milk, therefore, became a subtle way to brag about the quality of your china. While it’s hard to validate this theory, tea before milk is the preferred pouring order of the British Royal Family, who are likely to take an opportunity to boast their riches.

Regardless of its origins, almost all guides and sources now agree that tea should be poured into a cup first and milk (if desired) second. As for the claims that science has somehow settled this debate, besides a few industry-funded “studies” (really more like PR stunts) and a press release from the Royal Society of Chemistry based on research that was either never done or never published, I can’t find any actual scientific discussion of whether it’s better to add your milk or tea to your mug first.

Although, if a research group wants to study this in the future, they’ll likely benefit from ISO 3103, a publication from the International Organization for Standardization (ISO) that details standardized steps with which to brew a cup of tea for the purposes of comparison. The ISO is a non-governmental organization that exists for the express purpose of developing standards that are applicable across all 167 member countries for technical and manufacturing purposes. ISO 3103 was approved by all member countries, with the exception of Ireland, which objected on technical grounds due to the omission of a teapot warming step.

As I said, almost everyone seems to have strong opinions on this topic. I think I’ll be keeping my tea-brewing method to myself.

This article was written for the McGill Office of Science and Society. View the original here:

The Two Types of Erasable Ink and Why One Is Much Cooler Than the Other (McGill OSS)

3 minute read

Introduced in 1979, the Papermate Erasermate offered something that, up until then, had been science fiction: an erasable pen. While correction fluids and tape were a well-established solution to inky mistakes, covering up errors was not the ideal way to correct them. Erasermate offered a simple alternative—just remove them.

Nearly three decades later, in 2007, Pilot debuted their own erasable pen by the name of FriXion. You’d be forgiven for missing this product launch. Erasable ink seemed like yesterday’s news at that point—literally a decades-old technology. But FriXion pens are a lot more revolutionary than they may seem.

The older Erasermate type of erasable pens are made with ink contained in rubber cement during production. The rubber cement keeps the ink particles from absorbing into the paper but doesn’t prevent them from adsorbing onto it. What results is a mark on paper that is pretty similar to a graphite one made from a pencil. Since it hasn’t soaked into the paper but is just sitting on top of it, it can be rubbed off of the surface.

FriXion pens, meanwhile, rely on an entirely different phenomenon for their erasability. In fact, depending on how you think about it, they’re not really erasable at all.

The ink in FriXion pens is made of a three-component system. Contained in microcapsule particles with a diameter of 2-3 µm (For reference, that’s around 25 times smaller than the width of a human hair) are a leuco dye, a colour developer, and a colour temperature adjusting agent. The specific chemicals aren’t known—they’re proprietary trade secrets—but the general process works like this: At normal room temperatures the leuco dye and colour developer are in contact, and the ink is colourful. As the temperature rises the colour temperature adjusting agent starts to work, and the leuco dye and colour developer separate, rendering the ink colourless!

For FriXion pens, this colour change happens at roughly 60 ˚C. This can be achieved by heating the paper with a hairdryer or some other heat source or by rubbing it with a rubber eraser. Friction can make a surprising amount of heat surprisingly quickly—think about how you can start a fire by rubbing two sticks together.

A compound that changes colour with temperature is called thermochromic, and they have a few very important applications. Notably, receipts are printed on paper coated in such a compound. Cash registers don’t actually contain any ink. Instead, they are called thermal printers and work by selectively heating parts of their printer heads to produce the shape of a letter or number on the thermal receipt paper. Other technologies that use thermochromic dyes include mugs that reveal a design when heated and cold indicators on beer cans, like Coors Light.

The really neat part, in my opinion, is that this colour change reaction is reversible. Hence why one can debate whether FriXion pens truly are “erasable” or not. Lowered to about -10 ˚C (most freezers are around -18 ˚C) the “erased” ink will reappear as if by magic, but we know it’s actually just chemistry.

I am a big fan of erasable FriXion pens and recently experienced their reversible colour-changing phenomenon firsthand. Unfortunately, I left my notebook in the hot summer sun and returned to find it totally blank. Luckily, having researched this topic, I knew a couple of hours in the freezer were all I needed to recover my precious notes.

This article was written for the McGill Office of Science and Society. View the original here:

Why is Pepto-Bismol pink? (McGill OSS)

3 minute read

It’s minty, chalky, unpleasantly viscous, and useful for a wide range of stomach ailments, but why is Pepto-Bismol so vibrantly pink?

The active ingredient in Pepto is bismuth subsalicylate. Once in the stomach, bismuth subsalicylate breaks down into two products—bismuth and salicylic acid—the latter of which is rapidly absorbed into the bloodstream. Salicylic acid is the active ingredient in many anti-acne and wart products and is closely related to acetylsalicylic acid, better known as Aspirin. Bismuth is a metal with somewhat unique properties, including notably its low melting point of just 271.5 ˚C. As such, it finds use as a lead replacement in various contexts. One important one is in lead bullets, the use of which has been highly discouraged, or even outlawed in some places, due to its toxicity. If you have a free day, a bottle of bismuth subsalicylate and some laboratory equipment, you can even extract the bismuth from Pepto-Bismol—it’s iridescent and quite pretty!

Bismuth in the stomach is very poorly absorbed and combines with other compounds present to form various bismuth salts. These salts have antimicrobial activity and prevent bacteria from binding and growing on the mucosal cells of the stomach, as well as increasing fluid reabsorption and decreasing intestinal secretions and inflammation. In these ways, bismuth subsalicylate can help with a wide range of digestive issues, including nausea, diarrhea, stomach ulcers, heartburn, and even cholera.

Contrary to what you may be thinking, it is not bismuth subsalicylate that gives Pepto-Bismol its carnation colouring. That compound is beige. It turns out that Pepto is pink simply because Procter and Gamble dye it pink!

According to Pepto-Bismol, the doctor who developed their pink medicine in the early 20th century chose pink, but no one really knows why. They keep it pink because you don’t mess with success, and who can blame them? The practically neon hue of their product is instantly recognizable, even when their products are in chewable tablet or pill form. Even generic preparations of bismuth subsalicylate tend to stick to the pink colour palette.

In 1992, a Procter and Gamble spokesperson told the LA Times that the doctor chose pink to appeal to children, but as Pepto-Bismol is not recommended for kids under 12, that seems questionable. This recommendation is due to concerns that bismuth subsalicylate could contribute to a rare condition called Reyes syndrome in children. It’s for this exact reason that Aspirin (acetylsalicylic acid) is not approved for children under 12.

You shouldn’t worry about Pepto-Bismol turning you pink, but there is a slight chance it could turn your tongue, or your poop, dark black. This happens due to a reaction between the bismuth metal and sulfur in your mouth or digestive tract, producing bismuth sulfide. This might happen if you’ve recently eaten a lot of sulfur-rich foods—like cruciferous vegetables (broccoli, cabbage, kale etc.) or alliums (onions, garlic, leeks, etc.)—taken a high dose of a sulfur-containing medication (like sulfonamide antibiotics) or live somewhere with high sulfur concentrations in the water. Don’t panic; it’s only temporary and totally benign.

While the doctor who developed Pepto-Bismol and chose its hot pink shade probably didn’t know, the colour of a medication may have surprising impacts on how patients perceive its effects or rate its effectiveness. A couple of studies have found that patients are more likely to perceive warmly coloured medications (red/orange/pink/etc.) as stimulants or antidepressant drugs versus an association with tranquillizers or depressants for cool-coloured (blue/purple/green) meds.

When studied, the marketing of medications echoes this colour coding, implying a feedback loop between buying medications of a particular colour and associating that colour with that type of medication. Interestingly, studies have also shown that the colour of a drug can influence how bitter patients think it will taste and how strong they believe it is. Specifically for children, there’s a belief that red or pink medications make them look sweeter or more palatable to kids. So maybe the inventor of Pepto-Bismol was trying to invoke the idea of a strawberry milkshake!

This article was written for the McGill Office of Science and Society. View the original here:

You can’t hear this music, but it could still make you dance (McGill OSS)

1 minute read

Provided by bass instruments, the low-frequency parts of music tend to contribute the beat we actually dance to. Songs with lower-frequency baselines tend to have higher perceived “groove” ratings, but what if the frequency is so low that it falls outside humans’ audible range?

Researchers from McMaster University, Fitchburg State University and the Rotman Research Institute set out to test just that. Utilizing so-called very-low frequency (VLF) sound, researchers fitted participants with motion capture headbands at a live concert for electronic music duo Orphx and had them fill in pre- and post-concert questionnaires. VLF speakers were turned on and off every 2.5 minutes throughout the 55-minute performance, and the recorded mo-cap data was used to calculate participants’ head movement speeds in the presence or absence of VLF.

The resulting data showed that audience participants moved an average of 11.8% more when the VLF sound was on versus off. The researchers also performed additional experiments to confirm that the VLF was inaudible.

If it can’t be heard, how can VLF sounds contribute to a sense of groove or make people dance more? The researchers suggest that VLF sounds lead to changes in behaviour through subconscious processes involving our brains’ vestibular, vibrotactile, motor and reward systems. Sounds are mainly processed through our auditory pathways; however, low-frequency sounds are additionally processed via the vibrotactile and vestibular pathways.

While known for controlling our balance and proprioception (sense of where our bodies are), the vestibular system has previously been implicated in perceptions of rhythm. In addition, both the vestibular and vibrotactile pathways have close links to our motor systems. The researchers believe that one, or more, of these pathways, are responsible for the dance-inducing effects of VLF sound.

This article was written for the McGill Office of Science and Society. View the original here:

What Does Snake Venom Do to the Human Body? (McGill OSS)

2 minute read

There are more than 3000 species of snakes on Earth, ranging from the Barbados threadsnake at roughly 10 cm long (about the same as a deck of cards) to the reticulated python at around 6 m in length (almost as tall as an adult male giraffe!). Luckily, only about 600 are venomous, and only around 200 are venomous enough to seriously harm or kill a human.

Despite the existence of hundreds of venoms, nearly all snake venoms fall into one of three categories, depending on how they affect us: neurotoxins, cytotoxins or myotoxins.

Neurotoxins are common to the Elapidae family of snakes, which include cobras, mambas, coral snakes, and copperheads. They work on the nervous system by disrupting the electrical impulses that our nerves and muscles use to function.

Neurotoxins can mess with our neurons in a few different ways. Imagine your neurons like a lamp plugged into an electrical socket. For the lamp to function normally, it should be able to turn on and off at different times. With α-neurotoxins, it’s as if someone put a babyproof cover on the socket, preventing us from plugging our lamp in at all. The result? No light. On the other hand, with dendrotoxins, the lamp is plugged in, but no electricity flows from the socket to our lamp. Again, no light. But with fasciculins, it’s like the lamp’s plug is stuck in the wall. Constantly activated with no off switch, even though we want to go to bed.

Vipers favour the use of cytotoxins—venoms that directly damage cells. Some common types include phospholipases, which disrupt cell walls, and hemotoxins, which affect the circulatory system. Some hemotoxins trigger the destruction of red blood cells, while others affect the clotting factor of blood—either by making blood too clotted and thick to flow or too thin to ever clot and stop external bleeding.

Myotoxins are less common in serpent physiology but are found in certain species of rattlesnakes. They contain basic peptides (chains of amino acids too short to be considered proteins) that directly disrupt the flow of charged molecules our muscles rely on to contract.

With such a wide range of venom types and mechanisms of action, it’s no surprise that nearly every snake species needs a tailor-made antivenom. Luckily, Canada only has four native species of venomous snakes.

Nonetheless, it can be pretty tricky to identify snakes reliably in the wild. So, if you’re ever on the receiving end of a snake bite, seek medical attention immediately! Do not try to catch the snake to bring with you—some help for your doctors in identifying your attacker is not worth a second (or third, or fourth) bite.

This article was written for the McGill Office of Science and Society. View the original here: