Posts Tagged ‘how’

Science of electronic cigarettes, as seen on the Tourist

// January 2nd, 2011 // 1 Comment » // How Things Work, Science in the Movies

Happy New Year! On the first of January, I went to see The Tourist. It promised to be an excessively attractive movie starring Angelina Jolie and Johnny Depp, the two best heartthrobs on screen. I won’t spoil the plot, but I will say that one cool gadget graces the scene. The electronic cigarette.

As described in the movie, the electronic cigarette does not emit smoke, just vapour. The one in the move was shaped like a cigarette, complete with a red LED light on the end for a burning ember. He tapped the end to put it out, but I don’t think that’s necessary. The automatic versions just turn on when you breathe in, a sensor recognizes the airflow, and I’d say it turns off afterward.

Electronic cigarettes, designed by Chinese company Ruyan “to resemble smoking”, come in a variety of designs. From classic cigarettes to cigars to pipes. Even a ballpoint pen, so you can look like you’re intelligently thinking witty thoughts while taking a sneaky huff.

All the designs have the same basic features. A cylindrical battery, a heating element, and a mouthpiece. When the sensor picks up air flow, it switches on the battery which heats up the element, vapourising the nicotine mixture absorbed on material in the mouthpiece. Manual versions lack a sensor, and you have to press a button to get them started. The nicotine can be replenished by dripping fluid refills onto the absorbant material, or buying a new prefilled mouthpiece.

An electonic cigarette

An electonic cigarette

But it’s the mixture itself that’s really cool. It comes in a variety of nicotine levels and a variety of FLAVOURS. Some are designed to taste like certain brands (such as Malboro), some taste like regular ciggies, some are menthol, and others come in tastes of caramel, coffee or vanilla. One recipe listed on Wikipedia contains hardly any nicotine, but 8% alcohol. That’s a 16 proof cigarette delivered straight to your lungs! Wow. Seems dangerous.

What I wanted to know was how do electronic ciggies compare to the real thing when it comes to health. It seems like we’re still unsure. Electronic cigarettes only hit the market in 2004, so they’re pretty new still. Most countries are taking a conservative stance. In England they can be bought in pubs and smoked indoors. In New Zealand they are only available in pharmacies. In Australia it is illegal to sell them, but they can be purchased over the internet for personal use, and I believe there are no laws against it. Please correct me if I’m wrong.

The debate seems to center around the fact that these electronic cigarettes are KIND OF tobacco products and KIND OF smoking cessation aids… but kind of not. No studies have been done to show that they could help people quit smoking and become nicotine free. To me it seems more like you would quit smoking cigarettes, and start smoking the electronic version instead.

And what’s the harm in that? Most of the damage caused by smoking is not due to nicotine itself. It’s all the other crazy chemicals that come with it which cause the cancer and lung damage and so forth. Nicotine is just the stuff that keeps people coming back. It’s highly addictive, working on the reward system of the brain and our favourite neurotransmitter, dopamine. Smokeless cigarettes are a way to enjoy nicotine without getting a hefty dose of dangerous chemical cocktails. Plus the secondhand smoke is safer. So it’s an example of harm reduction. Plus your teeth would get whiter.

Of course, nicotine is not exactly a friendly chemical. It might not cause cancer, but it IS highly toxic. 60 mg can be toxic to an adult. Nicotine is made by the tobacco plant as an insecticide, need I say more? In fact, it’s also made by other members of the Solanaceae (nightshade) family, such as tomatoes. That explains why my basil plant is getting torn to pieces by insects while the tomato plant right next to it is still intact. So maybe we don’t want to encourage people to smoke anything.

But gun to my head, I think the electronic cigarette is a good thing. I don’t think young kids are going to be swayed by sexy marketing into becoming the next generation of smokers. I don’t think we’d allow such sexy marketing in the first place. I don’t even know why the government allows cigarettes to be sold at all; the health problems must cost the economy millions every year. But what do you think? Do you think electronic cigarettes would be the lesser of two evils, or a new evil all on its own, ready to pounce on hapless youths and struggling smokers and catch them forever with nicotine claws.

Physics of lapping lets cats drink without mess

// November 24th, 2010 // 2 Comments » // How Things Work, Recent Research, Science at Home

First up, apologies on the lateness of my post. A whole week has gone past! Oh me! I humbly do beseech you to forgive this old salt and do throw myself upon the deck in penance. Me only defense is that I have just moved from Canberra to Adelaide, and me Schooner does need an awful lot of bubble wrap. To distract you from me own slackness, I have scoured the nets for the cutest science story evah. I ply you with kittens thusly:

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Cats are a more delicate and refined animal than messy, smelly and drooly dogs. I’ve always been a cat person. I think they have higher standards. Turns out they also drink better than dogs.

Both dogs and cats lack the complete cheeks that humans have, which means they can’t drink water by suction like we can. Dogs get around this by using their tongues as a ladle, cupping the water from bowl to throat.

Cat’s do it differently. They lap water briskly, but not like a ladle. Instead, they DEFY GRAVITY and make the water lift up into the air like a glorious floating blob of refreshment.

Sounds crazy, but it’s true. When they dip into the dish, water adheres to the dorsal (top) side of their tongue. The surface tension (sweet, sweet hydrogen bondage) of the water drags a column of water into the air. The cat can thus pull water into its mouth using inertia.

The competition between inertia moving water up and gravity pulling it down sets the lapping frequency of the cat. Smaller cats with smaller tongues lap faster to drink, large cats lap slower. Observation of lapping frequency in big cats like lions shows the same kind of trend, suggesting they use the same physics as the household feline.

Cats might do this because it’s a neater, cleaner way to drink and it keeps their whiskers nice and dry. Whiskers have an important sensory function, so it’s worth the effort to keep them tidy.

The research was published in Science, and began when a researcher was watching his own cat drink. A video of the researcher and cat is below, and shows in super slow mo exactly how water defies gravity when a cat enters the equation.

Did you hear that? Did you? Not only is it physics, hydrogen bonding and gravity defying, plus, PLUS, the tongue could have implications for robotics of the future. Yeah. Robot cat tongues. It’s going to happen.

Actually tongues are very interesting. They obviously have no bones for support, so instead they have a muscular hydrostat system where support comes from muscles. The same thing happens in octopus tentacles, where muscles stretch in one of three directions: Along the tentacle (longitudinal), across the tentacle (transverse) or wrapping around the tentacle (helical.) When an octopus moves, one muscle contracts to become shorter which forces the muscles around to stretch, supporting the movement like a skeleton.

Cats and octopus. You know this post was worth the wait.

ResearchBlogging.orgReis, P., Jung, S., Aristoff, J., & Stocker, R. (2010). How Cats Lap: Water Uptake by Felis catus Science DOI: 10.1126/science.1195421

Noble Prize in Chemistry – Palladium catalysed reactions

// October 6th, 2010 // 1 Comment » // How Things Work, Science Communication

Image adapted from Jurii

The winners of this years Nobel Prize in Chemistry goes to Richard F. Heck, Ei-ichi Negishi and Akira Suzuki, for their work in palladium catalysed reactions.

Ah, a subject close to my own heart! As a student of Molecular and Drug Design, we studied this shizz in lectures. Hell, I think I even did a Suzuki reaction! That pretty well makes me famous IMHO.

SO – palladium catalysed reactions. What are they, I hear you say? Oh, dear gentle reader, how long do you have for me to BLOW YOUR MIND WITH CHEMISTRY AWESOME? Three minutes? K.

Carbon to carbon bonds are super important in the human body, which is pretty much made of carbon. Nitrogen, hydrogen and oxygen get a look in, but carbon is where it’s at.

There’s a big trend at the moment, has been for years, in designing small molecules as drugs. Some small molecules mimic the molecules naturally inside the body. Basically it’s telling the body what you to do in a language it can understand.

To make a carbon-based small molecule, you need to make some carbon to carbon bonds. The sad part is that carbon is a chiller, and isn’t keen on making friends with other carbons. Put a carbon and another carbon in a test-tube and they just won’t get it on. They don’t care to so much as hold hands.

HOWEVER, chuck some palladium catalyst into the mix and ba-zing! You’ve got yourself a sweet, sweet reaction that’s controllable and would otherwise have taken a zillion years to happen. Now we can create new molecules and drugs to benefit peeps everywhere!

Words cannot describe how nerdy and happy I am right now to write about palladium catalysed reactions. Maybe I’ve missed my calling as a chemist after all.

World’s sweetest antibiotic? The five ways honey kills bacteria.

// July 13th, 2010 // 5 Comments » // Drugs, How Things Work, Recent Research, Science at Home

HoneyYou’re at the doctors with a suspected infection, but instead of offering penicillin or erythromycin, they prescribe honey. Would you switch toast toppings? Take a honey pill? How about letting the doctor smear medical grade honey over the infected area?

People have been using honey (not mad honey) as medicine since ancient times, but until now we have never fully understood how it works. Research lead by Dr. Paulus Kwakman from the University of Amsterdam and his team have finally identified the key elements which give honey its antibacterial activity.

Bacteria are becoming resistant to drugs faster than we’re developing them. Honey might help because it works when other drugs don’t. Studies show it has good activity in vitro against antibiotic-resistant bacteria. An older study reports successful treatment of a chronic wound infections not responding to normal medicine.

So how does it work? It’s a combination of five factors.

1. Hydrogen peroxide, a kind of bleach. The honey enzyme called glucose oxidase makes hydrogen peroxide when honey is diluted with water. We clean toilets with bleach, and it’s pretty good at killing bacteria.

2. Sugar. Honey has so much sugar there’s hardly any water for bacteria to grow in.

3. Methylglyoxal (MGO), an antibacterial compound found in New Zealand Manuka honey a couple of years ago. It’s also found in medical grade honey which is made in controlled greenhouses, albeit in smaller amounts.

4. Bee defensin 1, a protein found in royal jelly (special food for queen bee larva.) This report is the first time bee defensin 1 has been identified in honey, and it works as an antibiotic.

5. Acid. Diluted honey has a pH of around 3.5, the acidic environment slows down bacterial growth.

These five things work together to provide a broad spectrum activity against bacteria. For example, S. aureus is vulnerable hydrogen peroxide, while B. subtillis is challenged only if MGO and bee defensin 1 are working simultaneously. Honey has the right mix for maximum destruction.

So that’s how bees keep their honey fresh and unspoiled by bacterial growth. Perhaps with this information we’ll create enhanced honey to guard against infection, improving on nature like we did with penicillin. Until then, I know what I’m having on my toast.

A Schooner of Science could be named Australia’s best science blog. If you enjoyed reading, please vote for me.

ResearchBlogging.orgKwakman, P., te Velde, A., de Boer, L., Speijer, D., Vandenbroucke-Grauls, C., & Zaat, S. (2010). How honey kills bacteria The FASEB Journal, 24 (7), 2576-2582 DOI: 10.1096/fj.09-150789

The needle free vaccine, how Nanopatch works

// April 22nd, 2010 // 4 Comments » // How Things Work, Recent Research

Nanopatches

Researchers from Queensland University have discovered a new way to administer vaccines, a Nanopatch. Smaller than a postage stamp, the patch puts the vaccine through your skin. No need for an injection.

So how does it work?

The Nanopatch is full of micro-nanoprojections containing antigen – part of the bacteria or virus you are immunising against. These nanoprojections puncture the skin and deliver the antigen into your epidermis. The puncture is a breadth of a hair deep.

In your epidermis are Langerhans cells, members of the immune system. Their role is to pick up antigens from infecting nasties, or in this case the Nanopatch. Once they have collected something, they physically move from the skin to your lymph nodes. Lymph nodes are the hub of the immune system. Once there, the Langerhans cells mature and display the antigen to passing naïve T-cells.

T-cells are specialised cells which specifically recognise one type of antigen. It’s like a policeman with a picture of just one criminal. A naïve T-cell doesn’t have a picture yet. It collects one from a Langerhans cell and other cells in the lymph nodes. With that the T-cell matures, looking out for the antigen. Next time it sees it, it will be armed and ready.

T-cells, along with B-cells, protect you from getting the same disease twice. T-cells in particular are needed to clear infections like HIV and malaria, and needle vaccines don’t stimulate them enough. The nanopatch focuses on T-cells specifically. It gives them their first look at the disease, without the pesky side-effect of getting traumatically ill.

According to Queensland University, the latest research shows that the Nanopatch can provide a similar level of protection to a needle delivery, but uses 100 times less vaccine. The Nanopatch is still being trialed on mice.

No more screaming kids on injection day isn’t the only benefit. The Nanopatch will be cheaper to produce than normal vaccines and doesn’t need to be refrigerated or administered by a trained nurse. Lead researcher Mark Kendall said “it is easy to imagine a situation in which a government might provide vaccinations for a pandemic such as swine flu to be collected from a chemist or sent in the mail.” It would be perfect for developing countries, where administering needle vaccines can be difficult and expensive.

ResearchBlogging.orgCrichton, M., Ansaldo, A., Chen, X., Prow, T., Fernando, G., & Kendall, M. (2010). The effect of strain rate on the precision of penetration of short densely-packed microprojection array patches coated with vaccine Biomaterials, 31 (16), 4562-4572 DOI: 10.1016/j.biomaterials.2010.02.022






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