Author: David Bradley

What are molecular sieves

As the name might suggest these are molecules that can sieve out other molecules, acting like a filter but on the molecular scale. They are usually composed of a highly porous mineral or organometallic compound, the tiny pores of which are usually of uniform size and shape.

Clays, porous glasses, microporous charcoals, active carbons, aluminosilicate minerals, zeolites, and various synthetic compounds which we’ve discussed in Elemental Discoveries in the past allow much smaller molecules to enter and either pass through or be adsorbed on to the inside surface of the molecular sieve. As such. molecular sieves can be used to absorb liquids and gases. For instance, water molecules are often small enough to enter such porous materials while larger molecules are not, making molecular sieves useful as drying agents, or desiccants. A molecular sieve can absorb water up to 22% of its own weight. The petroleum industry makes wide use of molecular sieves for purifying gas streams. You can find out more here.

For more on molecular sieves research check out the Elemental Discoveries archive and the Reactive Reports website.

Brainy pictures

It always surprises me what visitors to the site are searching for when they hit these pages. A common search this month is for brain pictures. Now, from the search keywords it’s not possible to tell whether it’s a photo of the brain, an MRI scan, or a schematic that the searchers are looking for. So, to cover all bases, here are a few links that might help:

All these images are hosted under the US government domain (.gov) and so should be copyright free, but don’t take my word for it if you plan to use them in your science project or for anything other than personal use. Google Images, of course, would have been my first port of call for finding brain pictures.

Play real air guitar

Air guitar shirtBB King had his Lucille, old slowhand his well-worn Strat, and who could forget Jimmy Page with his Gibson SG twin-neck? You too could join the greats and learn how to play guitar, thanks to new technology from Australia’s science research centre – CSIRO. And, all you have to do is put on their new designer shirt and start strumming…the air.

Engineer Richard Helmer in the Textiles and Fibre Technology section in Geelong has created a ‘wearable instrument shirt’ (WIS) which enables users to play ‘air guitar’ and make real sounds simply by moving one arm to pick chords and the other to strum the imaginary instrument’s strings.

“Our air guitar consists of a wearable sensor interface embedded in a conventional ‘shirt’ which uses custom software to map gestures with audio samples. ‘It’s an easy-to-use, virtual instrument that allows real-time music making — even by players without significant musical or computing skills. It allows you to jump around and the sound generated.”

The WIS works by recognising and interpreting arm movements and relaying this wirelessly to a computer for audio generation. There are no trailing cables to get in the way and no risk of electrocution when you’re getting all hot and sweaty thrashing away in front of your bedroom mirror.

The real advantage of the wear-guitar is that when you reach the climax of the gig you can smash your guitar against the imaginary stack of Marshall 4x12s without wrecking thousands of dollars of equipment. Just remember, once you’re done, to ask your mom not to add it to the regular laundry.

Performance enhancing steroids

Most sports stars know that injecting steroids to boost performance is plain stupid. But, some do it anyway, because the potential gains, they reason, outweigh the risks to health and the chances of being stripped of glory are much smaller than their chances of winning the medal without them.

Not all steroids are purely about enhancement. Another group of steroids, known as corticosteroids, are used to reduce inflammation and pain following injury. Alarmingly high doses are often used to speed up the recovery process but with potentially serious side effects on the tissues into which they are injected. As such corticosteroids injections are also banned in sports.

However, there is a drug produect available to errant sports people that can stimulate the body’s own production of corticosteroids, it’s a protein known by the tradename of Synacthen. It was essentially undetectable as only tiny quantities are needed to cause the desired stimulation and such small concentrations are easily lost in the background noise of other more abundant proteins in a blood sample.

Now, researchers writing in the journal Rapid Communications in Mass Spectrometry have developed an analytical separation and detection technique, based on chromatography and mass spec, that can pin down this elusive drug and render the cheats visible even if the compound is present only in incredibly low concentrations in a blood sample; even at 10,000,000 times lower concentration than other proteins in the blood plasma.

‘If the drug testing authorities adopt this new test it will close a gap in the current drug testing system, and mean that athletes will no longer be able to get away with this form of cheating,’ says lead author Mario Thevis, who works in the Center for Preventive Doping Research — Institute of Biochemistry, at the German Sport University Cologne in Germany.

Looks like a few well known sports celebs will have to start using RICE for their injuries again…

Get research papers free

Wouldn’t it be great if you could get all those research papers you need for free without having to wait for the publishers to all convert to open access?

Well you can, kind of.

Most of the time when you scroll through the ToCs (table of contents) pages at a publisher’s site, you’ll see a little red “free” symbol next to the abstract. Click for “full paper” or “pdf” and you’re usually taken to a login page where you have to enter your subscriber username or password. That’s fine if you’re at an institution with a site-wide licence for the content, but what if you’re away from your lab and don’t have a remote login?

Well, not everyone has noticed but some of the major journals do make their content free after a set time period. Papers in PNAS, for instance, are free after six months, no login required. But, six months is a long time in research and may be too late if you’re after the most cutting edge info.

Physicists of all flavours are fairly well served with preprints courtesy of the LANL preprint server, just head on over type in your keywords and pull up papers that haven’t even been published by the journals (yet). You can read the most recent physics preprints here. Physicists after IOP journals are also well served, this publisher gives free access to papers for the first 30 days after publication, which is rather unusual.

Biological chemists are fairly well served too, at least when it comes to the Journal of Biological Chemistry, which offers pre-edited papers that have been accepted, so-called “pips” (papers in press) for free. Once the papers go live, they’re pay as you go, but until then you can grab them for nothing more than a few mouseclicks as long as you don’t mind that some t’s may not have been dotted and a few i’s may have been left uncrossed. Set yourself a Google Alert to tell you when that page changes, export it as a newsfeed or have it emailed and you’ll be able to grab the papers as soon as they appear at zero cost. Same goes for Biol Reprod and several other journals. Also in biomedical is PubMedCentral, but that’s one of those OA systems, rather than freebies by the back door. More OA journals can be found at DOAJ.

For scientists who publish in Springer journals they can make a one-off payment of $3000 at the time of writing to allow their paper to be made available to readers for free. It’s like paying for infinite digital reprints, which works out at a very small cost per reprint and is probably well within the reach of only the most prominent labs, or multi-author papers where everyone chips in a few bucks to get the word out as far and wide as possible.

Crystallographers are well served too – one source of OA crystallography material can be found here.

For chemists a quite comprehensive list of free chemistry journals can be found here and there is also Chemrefer, which we have mentioned previously which lets you search by keyword for freebie papers.

Pop-up University

Was I seeing things? I don’t know. It’s never happened before.

I just visited the site of a well-known professor at a US University, Firefox alerted me to a failed pop-up ad. Curious as to what pop-ups the University researchers might be serving I refreshed the page and this time allowed the pop-ups.

They were ads for Flirtomatic and an online gambling site.

Curious, I thought.

So, I ran Spybot S&D and Adaware Personal just to double check that I hadn’t gained some trojan or spyware along the way. Of course, these two programs may have let something slip through the net but working together they pretty much catch 99%.

Nothing, perfectly clean machine.

Opened the site again, this time in Internet Explorer 7. Same result. Pop-ups blocked. Tried it from another machine offsite and asked a couple of friends to double check. Same result.

I thought for a moment it might be University policy, but no other pages produced the pop-ups. I suspect therefore that it’s someone in the department, a student with an affiliate ad account, perhaps, hoping to cash in on site visitors. I asked the webmaster at the University to look into this and within 24h they’d replied to say the ads had been removed. So, it wasn’t just me. They didn’t say whether my hunch was right or whether it was a compromised server.

Of course, Sciencebase would never stoop so low. We carry editorially independent advertising to help subsidise the site, of course, who doesn’t? But, if you ever see a pop-up let me know and I’ll advise on how to clear your site of Spyware, because it won’t have been coded at this end of the service!

Rare cattle and human hybrids

Human cattle hybridIs it just me or is there a certain irony to be found in the timing of a rare cattle and other animal breeds conservation initiative being announced in the UK and stem cell researchers at Newcastle University requesting authorisation to hybridize nuclear-free eggs from cows with a human skin cell nucleus?

Ironic or not, both are issues that will inevitably attract great controversy over coming days.

The rare breeds initiative will build a database of livestock breeds across the UK to help. Announcing the launch of this genetic “Noah’s Ark”, the Department for Environment, Food and Rural Affairs sets out recommendations for how the industry and Government can improve and maintain the diversity of the UK’s livestock genetic material in the future. Among its detailed recommendations are the maintenance of an advisory body that better informs the public, industry and policymakers on the country’s farm animal breeds, the collection of high-quality information on genetic resources to provide effective ways for their future use, and support for the prioritisation, development and implementation of projects to conserve genetic diversity.

‘This plan is important economically, socially and culturally,’ says Food and Farming Minister Jeff Rooker, ‘We have a fine tradition in this country of breeding a diverse range of farm animals which in many cases can be found across the world.

‘However, there are growing concerns over genetic diversity as growing economic pressures have lead to a few specialised breeds spreading across the globe. The threat of exotic diseases is also a threat to diversity in some breeds.”

On the same day, scientists at the University of Newcastle upon Tyne sought regulatory approval to fuse an egg from a cow that has had its nucleus removed, with the nucleus of a human tissue cell, from skin for instance. The resulting hybrid, which would essentially be 99.9% human with only a tiny amount of mitochondrial DNA from the cow remaining. The egg could then be cultured and stem cells that are human to all intents and purposes, harvested from the growing chimera. The hybrid embryo would, the researchers say, be destroyed once the stem cells were collected.

They point out that human eggs are a precious and scarce a commodity, whereas there is a glut of cow eggs. Cow eggs are also a lot easier to handle than the eggs from the conventional source of laboratory test eggs, the mouse.

The UK’s Human Fertilisation and Embryology Authority (HFEA) is yet to grant permission although teams at Edinburgh University and King’s College London are also seeking approval for similar research.

The aim of creating such a human-cow hybrid is to develop the techniques that will eventually be used to create 100% human stem cells in the laboratory without having to expend years of human eggs honing the necessary skills that will ultimately make stem cell production routing.

Both strands of research, the genetic conservation program and the human-cow hybrid are already provoking a reaction from those who consider such efforts a violation of animal rights, another example of human exploitation of animals, and the lobbyists who want an outright ban on stem cell research.

Stephen Minger of King’s College London told journalists that, “We feel that the development of disease-specific human embryonic stem cell lines from individuals suffering from genetic forms of neurodegenerative disorders will stimulate both basic research and the development of new medicines to treat these horrific brain diseases.”

PS Before anyone says, yes, I know it’s a picture of a bullock not a cow and that, yes, you’d be hard pushed to extract cattle eggs from him, hybridised or not!

Irish chemistry thrives on spin

Irish chemistryPeace talks and an IRA ceasefire were only dreamed of the last time I visited the city of Belfast in Northern Ireland and the Queen’s University. Indeed, at the time there were still a few grey armoured vehicles on the streets and the city centre was still gated. There were British soldiers patrolling outlying villages and on the day I departed there was a major bomb scare at an unopened shopping centre, which meant a long-winded taxi diversion back to the airport. Times have changed.

Beyond the snazzy new university logos, truncated Qs, and mission statements lies a thriving department at Queen’s University Belfast that has attracted to its membership several high-performing researchers from some prestigious international laboratories. Among them are such rising stars as Frederic Meunier who has worked with pioneering catalytic chemist Marc Ledoux at Strasbourg, Raman spectroscopist and Innovative Molecular Materials scientist Steven Bell, and Joe Vyle an alumnus of the laboratory of Marv Caruthers in Boulder, Colorado, who invented the chemistry used during the past 20 years for synthesising DNA on machines. And, of course, AP de Silva whose pioneering work in molecular logic has already led to multimillion dollar sensor technologies and is making inroads into the world of combinatorial chemistry through the development of molecular computational identification (MCID)

Alternatives to animal testing

Despite the claims of extremist animal protesters, scientists do not in fact relish the use of animals in tests of new pharmaceutical and other chemical products and are continually searching for valid alternatives that might reduce the numbers of small mammals, for instance used in pesticide safety tests.

According to Jennifer Rohn writing in this week’s issue of Chemistry & Industry magazine, the thousands of test animals currently need for pesticide evaluation might be replaced by tricking ticks into setting up home on a faux cowhide. The hide, developed by Swiss researchers consists of a skin-like silicone membrane, complete with hair that rests over a layer of cow’s blood. The insects are so comfortable with the faux-cow that they set up home, mate and lay eggs.

Currently, some 10,000 animals are used annually to test new tick-fighting chemicals because pesticides to kill Lyme-disease carrying ticks and other insects are constantly being updated.

Thomas Kröber and Patrick Guerin at the University of Neuchâtel confirmed the effectiveness of their test bed using a standard tick pesticide, firponil, and observing central nervous system damage revealed by leg trembling in the ticks. They report details in the journal Pest Management Science.

Vicky Robinson, chief executive of the National Centre for the Replacement, Refinement and Reduction of Animals in Research, said: This research takes a simple idea and applies it to great effect, resulting in a potentially significant impact on animal use. Most importantly, it demonstrates that finding ways to reduce the use of animals in research and testing is as much about improving the science as it is about considering the welfare of animals.’

Obviously, the tick test avoids the need to test on rodents or other laboratory mammals, but it remains a devastating blow to tick lovers everywhere.