Ivy vs UV, could plant nanoparticles be the new sunscreen?

// July 21st, 2010 // No Comments » // How Things Work, Recent Research

Image by Tamara Horová

Research published in June shows that nanoparticles from the English Ivy might make superior sunscreen to current brands, offering high broad spectrum protection and lasting for longer than current creams.

The trend towards organics has influenced industries like food, coffee and shampoo as well as pretty much everything you can conceivably imagine. Over the past few years, some people have become worried about sunscreen containing nanosized titanium dioxide and zinc oxide. While these absorb light in the UV spectrum and protect the skin, perhaps the tiny particles could be absorbed through the skin and unleash toxic hell on the body! These could be unfounded fears, and damage from the sun is far more likely than damage from the sunscreen.

Personally, I’m all for synthetic chemicals. I think dear old Mother N has some freaky chemical concoctions of her own, many of which did not evolve to help humans but people inject it into their face anyway. Natural does not mean safe in my book.

All the same, ivy nanoparticles make a strong case. They absorbed or scattered light in the UV spectrum over five times better than titanium dioxide. The absorption dropped quickly when reaching the visible spectrum, so like current sunscreens it would look near invisible on your face.

Just like ivy can stick to brick walls and trees, the ivy nanoparticles have adhesive qualities. They could lead to sunscreens which last longer and are more water resistant. Hey, maybe that’s why Adam and Eve seem to always have ivy covering their-

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Xia, L., Lenaghan, S., Zhang, M., Zhang, Z., & Li, Q. (2010). Naturally occurring nanoparticles from English ivy: an alternative to metal-based nanoparticles for UV protection Journal of Nanobiotechnology, 8 (1) DOI: 10.1186/1477-3155-8-12

The Japanese bullet train, designed by kingfishers

// July 18th, 2010 // 1 Comment » // How Things Work

Images by heavenlyvacation and MJTR (´･ω･) on flickr

It’s a beautiful example of biomimicry, nature informing technology. The shinkansen bullet trains of Japan are airplanes on rails, traveling at over 300 km per hour in comfort and style.

Traveling at this speed, tunnels present a problem. When the train enters the tunnel it compresses a cushion of air ahead of it. The compressed air waves become a small shock wave when they exit the tunnel, moving through the air faster than the speed of sound. The tunnel boom sounds like a clap of thunder, and residents complained.

Engineers looked for examples in nature to solve the problem, and they fixed on the kingfisher. When the bird dives into the water for fish it makes hardly any splash. They generated computer models and found that modifying the nose of the train to mimic the kingfisher bill would reduce tunnel boom. The new generations of bullet trains now sport the kingfisher look and are quieter, faster and use 15% less electricity.

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Why moths circle lamps, and darkness is our friend

// July 16th, 2010 // 2 Comments » // How Things Work

Sydney Opera House. Image by Froge

I wear my sunglasses at night. It’s for the light pollution. New Scientist today sent out a plea to bring back the night for wildlife’s sake, particularly birds, bats and turtles.

Moths are also at risk to death by light. In Australia, the Bogong moths cause October plagues around Sydney and Canberra. They swarm houses, government buildings, and sometimes land on bosoms of opera singers during the Sydney Olympics (or was that the Hawk moth?)

The reason for the plague is simple, we stupidly built cities near their migratory paths. Every spring the Bogong moth travels from the plains to the mountains, to get away from the heat. They spend the summer lying dormant in caves, aestivating (hibernating in the summer.)

Aboriginal groups would sometimes collect them, cooked they taste nutty and are an excellent source of protein. Unfortunately it’s not an option anymore because they eat stacks of pesticide as caterpillars on the plains.

It’s a common thing to see a moth circling a lightbulb. Why do they do it? They aren’t actually attracted to the bright lights, it’s a mistake in navigation. At least, according to one theory, though there are others I like this one best.

Bogong Moths, Image by Pbpanther

When moths make the migration, they need to know how the hell to get to the mountains. I sail by the stars, but moths fly by the moon. By keeping the moon at a certain angle to the side, they can fly in a particular direction. For example, if you know the moon is in the north and you want to go west, you would keep the moon on your right hand side. I think a similar method was used in Apollo 11, when their navigation systems were down (I’m going by a vague recollection of Tom Hanks following the Earth out the window of the ship.)

It works because the moon is so far away the angle doesn’t change as you move. But imagine you tried the same thing with a street light. If you kept the light on your right, you’d end up going around in circles. Just like moths do.

Some moths don’t fly in circles around light, they just WAP into them. They might be using the same method, but aiming directly for the moon instead of keeping it to one side.

In Adelaide we have trees with lights mounted to shine up on them all night. I would like to know if it damages tree growth or the native wildlife around it. What are your thoughts, and when was the last time you really saw the stars?

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

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

You’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.

Kwakman, 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

Ten years since the Human Genome Project

// June 26th, 2010 // 2 Comments » // How Things Work

Image credit: Russ London

This picture is a printout of the human genome in a series of books in London. The 3.4 billion units of DNA code are in more than a hundred volumes, each a thousand pages, in type so small it’s hardly legible. That’s some good reading.

The human genome project was pretty exciting science, hell it still is. A few years ago they thought it would revolutionise medicine, cure cancer, save the world.

It hasn’t been that simple. After all, the amount of DNA we have in common with apes and fruit flies is pretty astounding, knowing the code is not enough. The way the code is read is also crucial, and we don’t understand that very well.

One thing that always interested me was epigenetics, which are non-DNA-coded inherited traits which are passed on through generations. For example how DNA is packaged in the cell determines which parts of the code are read and which are ignored. A heart cell has the same DNA as a hair follicle, but because of epigenetics we don’t have hairy hearts, or hearty heads.

Part of what the human genome project revealed was how little we know about DNA, and how many mysteries are still wrapped up inside us. Nonetheless it was one of the most important projects in human scientific history, and to that let us drink rum!

The strangeness and charm of subatomic particles

// June 7th, 2010 // 4 Comments » // How Things Work, Jibber Jabber, The Realm of Bizzare

In early high school I was told an atom was the smallest piece of matter in the universe. If you divided matter into pieces as small as they could be, the smallest piece would be one atom. Utter BS, according to later high school years. An atom is made up of protons, neutrons and electrons. Protons and neutrons can be further divided into quarks.

When I get to reading about subatomic physics and chem I quickly get confused and frustrated. My love is for the elegant simplicity of chemical reactions, effervescence, fluorescence, quenching and conjugation. Quarks are not so simple.

There are six flavours of quarks, and yes, “flavour” really is the technical word for it. They are called up, down, top, bottom, strange and charm. A proton is made of two up quarks and one down quark. A neutron has two down quarks and an up quark.

The quarks were discovered by particle accelerators. Strange quarks are found in cosmic ray particles with a strangely long lifespan. Charm quarks are charmed because they complete the symmetry of the quark set. Top and bottom quarks are similar to up and down, and were originally called truth and beauty. The top quark has a mass almost as much as an atom of gold, which is pretty dang heavy!

Pictured above, UK band Florence and the Machine has written a new song about love and quarks. It’s called Strangeness and Charm and has only been played live. Here is the best quality audio I’ve been able to find of it, I’d love to see it live. There are rumours that her new album is science-inspired, can’t wait to hear it.

What is the synthetic cell?

// May 22nd, 2010 // 1 Comment » // How Things Work, Recent Research

Two days ago scientists at J. Craig Venter announced the creation of the first self-replicating synthetic cell, a bacteria with DNA made in a lab. How did they do it, and what does it mean for us in the future?

First up, the scientists didn’t make life out of nothing, and they didn’t make a new species. They recreated a bacteria that already existed, and developed the techniques to do it.

The bacteria is Mycoplasma mycoides. It’s a parasite which lives in cows, and some subspecies cause cow lung disease. It has a circular chromosome made of just under 600,000 base pairs, making it a small genome.

The scientists had the genome sequence of M. mycoides and split it into bite-size portions and then synthesised. Synthesising DNA is nothing new, scientists have been able to write DNA code for quite a while, and can write whatever code they want to.

These little chunks were put into yeast, which can be forced to absorb little bits of DNA. Inside the yeast, the chunks can be sewn together. It’s called recombination. The resulting medium chunks were taken out and put into more yeast to be sewn together making large chunks. There were 11 large chunks were put into more yeast, and sewn together into one complete genome.

Along the way and at the end they checked the code was right by doing PCR tests, genetic fingerprinting made famous by CSI.

Result: A synthetic genome, written by a computer and put together in yeast sweatshops.

Now they had to get it into a bacterial cell. At first they tried to put the DNA into bacterial cells of a similar species, M. capricolum. They ran into trouble at first, because the DNA they had was unmethylated (lacking methyl groups) and the bacteria destroys DNA which is unmethylated. It’s a clever defense mechanism, and they got around it by methylating the DNA before putting it in.

Finally success. The synthetic genome was put into an M. capricolum bacteria where it replaced the normal genome. The bacteria were controlled by the new, synthetic chromosome and were able to replicate billions of times.

What does it mean for us in the future? The technology these guys have developed could be used to alter the DNA of bacteria and make them do new things. From medicine to clean water, the benefits could be huge. We already have this ability to some extent, but it opens up some new doors.

Some organisations have raised concerns about the work. Could a new bacteria be unleashed and take over the world? Probably not. It’s hard to predict how new genes will work in cells, and everything is linked together in a way we don’t understand now. Too much tinkering to the genome will probably not be tolerated by the cell. And if it did get outside, it would probably be extinct pretty quickly because it doesn’t have thousands of years of evolution to prepare it for the world.

If it did get out, we could track it back to the company in charge. These guys watermarked their genome by adding some quotes into the DNA/protein code. Now that’s just epically geeky!

Gibson, D., & et al (2010). Creation of a Bacterial Cell Controlled by a Chemically Synthesized Genome Science DOI: 10.1126/science.1190719

Some (bacteria) like it hot

// May 13th, 2010 // No Comments » // How Things Work, Science in the Movies, The Realm of Bizzare

New video up!

I started this video back in January and 95% finished it before I moved to Canberra and bought a laptop. I haven’t had a chance to complete it and upload it… until now.

The montage part is my favourite.

Miracle fruit makes life a little sweeter

// May 5th, 2010 // 9 Comments » // Drugs, How Things Work, Just for Fun, The Realm of Bizzare

A mouthful changes your perception of taste, making everything you eat for an hour afterward taste sweet. Lemons taste like oranges, oranges taste delightful, strawberries are to die for. Sounds like something illicit, a taste trip.

It was about a year ago I first heard of miracle fruit. It’s a berry from West Africa. There’s a chemical inside aptly called miraculin which is responsible for the flavour changing fun. Miraculin is a protein with some carbohydrate chains attached. It might work by changing the structure of taste buds, causing the sweet receptors to be activated by normally sour tasting acids. So if you have some lemon juice, your sweet receptors go “ooh, that’s sweet!” and your brain buys it. It’s a tad dodgy, as large amounts of lemon juice make you feel disgusting. May help with the treatment of scurvy though.

Miraculin and miracle fruit do not taste sweet themselves unlike curculin, a protein which comes from a plant in Malaysia that has similar taste-changing properties. There’s another plant derived class of chemical called gymnemic acids, which has the opposite effect. It’s an anti-sweetener that lasts for 10 minutes, and makes sugar water taste like regular water.

According to the Wiki Gods, a company planned to bring it to the USA as a food sweetener in the 1970′s. The FDA tentatively approved it as “generally regarded as safe” because people had been eating it for so long with no ill effects. But at the last minute, they changed their mind and said it was considered a food additive which needed more stringent testing. The company didn’t have the cashola to fund it, so that was the end of the mass market plan. For now anyway.

Want to go on your own taste trip? You can buy tablets containing dried miracle fruit from the internets. They ship all over the world. Some people like to have miracle fruit parties, where they serve a range of foodstuffs and provide the magic tablet.

It sounds like a drug to me. And drugs are bad, mmkay. A Schooner of Science is not responsible for your crazy shenanigans. But if you’ve tried it, tell me about it and post a comment below.

The needle free vaccine, how Nanopatch works

// April 22nd, 2010 // 3 Comments » // How Things Work, Recent Research

Nanopatches

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.

Crichton, 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