David Bradley – Page 333

Molecular Photos

Hexaferrocenylbenzene structure Will Davis emailed me from France to ask if the molecular structures on the site are photos:

“I have read a book written about five years ago by a research biologist who wrote that …no one has seen a molecule. Now I see on your website photos of molecules. Are these real photos or a representation. Is this biologist either wrong or out of date?”

Well, he’s right and he’s wrong. You cannot take a photograph of a molecule. For a photograph you need light and the wavelength of visible light is just toooo long to resolve the features of a molecule. So, no, those aren’t photos of molecules you see littered around Sciencebase, I draw them using software such as ACD/Labs’ ChemSketch and then render them in Diamond, which can produce photorealistic renditions of a chemical structure. An additional step to add shadowing and make them even more 3D realistic is possible using Pov-Ray.

However, that said, molecular imaging has moved on during the last few years and it is possible to detect the presence of a molecule using the tip of something like an atomic force microscope (AFM) and to then use the perturbations of the tip to generate a three-dimensional image of the surface of said molecule.

Copper Sulfate Swimming Pool

swimming pool Belgian scientists today reiterated a warning that certain cases of asthma could be linked to swimming in stuffy “chlorinated” indoor pools but chemistry may have the answer, according to charity Allergy UK, which has awarded its ‘Seal of Approval’ to a novel alternative of which hot-tubbing ancient Greek philosopher Archimedes would be proud.

The novel solution involves using copper sulfate at levels permitted for drinking water to temper bacterial blooms in a swimming pool rather than to attempt to destroy them completely. The idea was discovered by the Greeks way back when but is used today by NASA to keep drinking water clean in space.

The product, which goes by the name Pristine Blue, is approved for use in the US, and allows the 1 in 3 kids who suffer an allergic reaction to pool “chlorine” to get in the swim without having to worry about the reaction. It also means an end to stinging eyes, which are caused by pool “chlorine” reacting with nitrogen compounds in sweat and urea that mysteriously make their way into most pools.

The copper sulfate approach also avoids damage to hair, swimming costumes, and pool liners, which normally suffer from the bleaching effects of chlorine.

Allergy UK’s Business Development Director, Jules Payne, said Pristine Blue could transform the lives of millions of families across the UK. ‘We are very excited to present this award to such a groundbreaking and innovative product,” she said, “The benefits to allergy suffers are immense, and as families prepare for their summer holidays the demand for a chlorine alternative is at its highest.”

Red Red Wine

An ideal solution for accurately and rapidly monitoring red, red wine during the fermentation process without the need for direct sampling for chemical analysis has been developed by Australian researchers led by Daniel Cozzolino of the Australian Wine Research Institute, in Adelaide.
The team recognised the need of the modern wine industry for tools that can assist in process control and quality assessment during fermentation and bottling but that can be carried out without complex sampling, preparation by an external lab. they have used chemometrics and Visible-near infrared spectroscopy to monitor concentrations of sugars and phenolic compounds, in red wine and so offer the industry a new approach to quality control.

Uncork vintage news here.

Face to face with gold nanoparticles

Bling comes to the world of nanotechnology, as japanese scientists coat crystals with gold particles. The modification of specific crystal faces of organic single crystals using gold nanoparticles could open up new possibilities for crystal engineering of materials with novel optical, electronic, and catalytic properties, according to the researchers.

Kazuki Sada, Seiji Shinkai, and colleagues of Kyushu University, in Fukuoka, Japan, have demonstrated that gold nanoparticles can be made to adhere to only certain faces of crystals of the amino acid cystine, suggesting that such “building blocks” might be used for creating sophisticated nanostructures with designer facets.

Read about the ultimate nano bling here.

Cold sore virus blocks immune system

It’s no wonder that sufferers find cold sores so hard to get rid of. A newly identified method deployed by viruses to escape the immune system has been discovered by researchers at Yale University. Writing in the August issue of Nature Immunology, the team describes how many strategies devised by viruses to ‘hide’ or ‘escape’ are well known, but HSV-1 (herpes simplex virus 1) seems to employ an entirely new mechanism.

Immune cells called natural killer T cells are important in detecting and containing HSV-1 infections, which cause cold sores. HSV-1 particles are ‘displayed’ on the surface of infected cells, enabling the natural killer T cells to distinguish between infected and uninfected cells. The molecule CD1d, which presents HSV-1 particles, constantly moves in a loop from the cell surface to the interior of the cell to sample and display of the contents of infected cells to natural killer T cells.

Peter Cresswell and colleagues demonstrate that HSV-1 blocks this loop; specifically preventing CD1d molecules from returning back to the cell surface. As a result, HSV-1-infected cells appear to be uninfected and are therefore nearly ‘invisible’ to natural killer T cells. The researchers concede that they don’t know exactly how the virus blocks CD1d looping, but once they find out this activity could become the target for new drug discovery efforts for treating this nasty infection.

For more on HSV-1 check out Wikipedia

Dietary stress

“Diet is an important part of healthy living,” Jeremy Nicholson of Imperial College revealed to SpectroscopyNOW, “it is just some things that are supposed to relieve stress – and widely touted by healthfood companies as being good for you – do not metabolically ameliorate the effects of even very minor experimental stress.” He and his colleagues have used NMR spectroscopy to analyse marker compounds in blood samples from rats under stress that have had their food switched to included polyunsaturated fats. “No one has actually tested this particular health claim before and this one doesnt stand up well,” Nicholson says. Additionally, the research shows it is possible to accurately measure and quantify how changing diet impacts health. This could ultimately lead to the development of more targeted and more effective products.

You can read the full details in my news round-up on spectroscopynow.com

Needle free bird flu vaccine

A needle-free, DNA-based, vaccine against avian influenza strain H5N1 has been developed by UK company Powder Med Ltd and will soon enter clinical trials.

This new vaccine is based upon PowderMed’s proprietary system for delivering DNA
vaccines — it is a needle-free injection device that fires gold particles coated with DNA
(encoding genes specific to the flu strain) at supersonic speed into the immune cells of
the skin. This first-time-in-man clinical trial will examine the ability of a vaccine based
upon the Vietnam H5N1 avian influenza strain to protect against a potential pandemic
form of flu.

A previous study, conducted by PowderMed in the United States, demonstrated that this
vaccine technology was able to produce 100% protective immune responses in adult
volunteers to a vaccine which encoded an annual influenza strain

Of course, who’s to say H5N1 will be the cause of the imminent bird flu epidemic or indeed that any avian influenza strain will be the next big viral attack on the human race. There are also sorts of terrifying possibilities lying dormant in exotic hosts the world over…think SARS…think HIV…think ebola…

This is my report from the Royal Society on emerging viral infections

Windows admin protection

Here’s a neat little tip I picked up from Webmasterworld.com. If you’re worried about catching an infection from a contaminated website, then create a new user on your Windows XP machine that doesn’t have administrator rights.

Start-Control Panel-User Accounts
Create a new account (JaneDoes, frinstance)
Set as “Limited” user

Then, when you plan on visiting suspect sites, logoff from your admin account and logon as JaneDoe. Now, most rogue installers that the suspect site tries to set in motion will not be installable because JaneDoe’s account doesn’t have install rights.

Please don’t rely on this for full protection. Get Spybot S&D (the genuine one) and use its Immunize function to protect your browser. Or, join 15% of US net users who have adopted Firefox as their browser of choice and make sure you keep a tight rein on sites that you allow to install software.

Explosive sex, coral killers, room for shrooms and more

This week the Alchemist discovers that carbon dioxide could pose a serious threat to marine life and in particular corals and the marine ecosystems that depend on them. We also find out how publication of new rigorous research into the effects of ‘shrooms’ could represent a watershed moment in understanding hallucinogens. Solving the problem of soliton structure is set to lead to new types of actuators and fine control for artificial muscles and TEM stacks up carbon nanotubes for peak-time viewing. Finally this week, explosive sex in a tube. But, you’ll have to wait till at least 2008.

http://www.chemweb.com/alchemist-current

Multitasking drugs

An issue I have written about for the Nature drug discovery site is the re-marketing of pharmaceutical products for uses other than the original one for which a drug was developed. The latest example is the emergence of the so-called “morning after” pill RU486 as a rapid-acting antidepressant (it has already found use in treating certain cancers and psychotic depression).

RU486, mifepristone, is a steroidal hormone similar in chemical structure to progesterone. It inhibits the progesterone receptor and so is termed an ‘antiprogestin’, its effect is to induce abortion.

This week New Scientist reports on how RU486 might work as an antidepressant:

“The hormone treatment is based on earlier findings that stress plays a major part in triggering and prolonging depression. Stress hormones appear to damage a part of the brain called the hippocampus. The region is susceptible because it is particularly rich in hormone receptors, allowing it to regulate ongoing hormone release,” the magazine says.