Wednesday, June 1, 2011

YouTube chemistry sensations share formula for success

It started on an impulse, made unlikely YouTube stars of its scientific presenters and has grown to a global audience of more than 15 million.

Now the remarkable story of the meteoric rise of The University of Nottingham's of Videos has been hand-picked as a prize essay in this month's edition of the prestigious magazine Science.

The Periodic Table of Videos (PTOV) exploded on to the social media scene back in 2008 when scientists in the University's School of Chemistry and BBC–trained journalist Brady Haran embarked on their mission to document every single one of the 118 chemical elements in a fun, lively and often unconventional way.

Within a few short days the videos had become a YouTube sensation, attracting more than 100,000 hits and provoking a stream of enthusiastic comments and an online following dedicated to eccentric hairstyle and seemingly endless selection of chemistry-themed ties of 'the Professor', green chemistry expert Martyn Poliakoff.

Cut to almost three years later and the project has evolved into a chemical news channel covering topical events — themed videos on everything from the 2008 Olympic games, the chemistry of Christmas and the scientific creation of a perfume for Valentine's Day.

As of May 2011,the site boasts 320 videos with content covering molecules as well as elements which have been viewed a total of more than 15 million times. Its YouTube channel has attracted more than 44,700 subscribers in more than 200 countries and territories, with dedicated followers ranging from Nobel laureates to a six-year-old boy in Nova Scotia.

The most-viewed , in which a cheeseburger was plunged into hydrochloric acid, has attracted nearly 458,000 views and overall 26 of the individual PTOV videos have attracted more than 100,000 views.

The project's spin-off sister channel Sixty Symbols, in which physics and astronomy are presented by Nottingham scientists, already has 29,600 subscribers and 138 videos, all filmed and produced in a similar format to The Periodic Table of Videos.

The project was inspired by the year that Brady had spent as filmmaker-in-residence for Test-Tube, an online showcase for the University's scientific research, presented by scientists themselves in their own words.

In Science magazine this month, Brady and Professor Poliakoff reveal PTOV's formula for internet success after their essay was chosen as winner of this month's SPORE (Science Prize for Online Resources in Education) Series.

They muse on the popularity of the videos, putting the enthusiasm of the response from the audience down to the spontaneity of the 'live chemistry' approach and soap opera or reality TV feel and the audience's affinity with the scientists themselves. Professor Poliakoff is joined by a wider regular cast of characters including lanthanide and actinide chemist Stephen Liddle, Peter Licence or Deborah Kays who demonstrate many of the experiments and the 'long-suffering and usually silent' technician Neil Barnes.

"PTOV does not hesitate to show scientists as human, sharing their moments of happiness and grief with the viewers. When demonstrations fail, they still appear in the videos, especially if they are amusing. Shortcomings are never glossed over or edited out, which ensures the team is seen as honest — they are not 'selling' anything apart from a shared love of chemistry," they say.

The impact of PTOV and its success as a resource in daily use in classrooms and home worldwide is probably best judged by the many thousands of comments and unsolicited comments received from viewers, including those from school pupils who say the videos have inspired them to pursue a career in and teachers who use them to support the learning of their students.

The ability of the filmmakers and to work quickly, sometimes with a three-hour turnaround, has allowed them to react quickly and respond to breaking news, such as their explanation of the recent nuclear crisis in Japan. This has led to their material being featured in the UK national media and blogs worldwide.

More information: … riodicvideos

Provided by University of Nottingham (news : web)

Recycling of Alzheimer's proteins could be key to new treatments

The formation of abnormal strands of protein called amyloid fibrils -- associated with two dozen diseases ranging from Alzheimer's to type-2 diabetes -- may not be permanent and irreversible as previously thought, scientists are reporting in the Journal of the American Chemical Society. Rather, protein molecules are constantly attaching and detaching from the fibrils, in a recycling process that could be manipulated to yield new treatments for Alzheimer's and other diseases.

In a study that focused on the fibrils associated with Alzheimer's (AD), Natalia Carulla and colleagues explain that scientists once believed that the fibrils themselves caused the memory loss and other symptoms of AD. During the last 10 years, however, suspicion has fallen on some toxic intermediate of the process through which those fibrils form in the brain. This study suggests that fibrils could be a source of those toxic intermediates.

The new study used laboratory techniques to detail molecular recycling within fibrils formed by two proteins, Aß40 and Aß42, which is most associated with AD. After monitoring recycling for 40 days, they found that both Aß40 and Aß42 molecules recycle within the fibril population, although to different extents. After 40 days, 80 percent of the molecules making up Aß40 fibrils underwent recycling while only 30 percent did so in Aß42 fibrils. These observations imply that Aß42 recycles more slowly.

"In the context of AD, demonstrating that recycling occurs in the fibrils is a step forward but it is also crucial to identify the recycling species involved; whether they are individual Aß units or small aggregates made of several units," explains Carulla. "It will be important to address if differences in the recycling species within Aß40 and Aß42 fibrils are relevant in the development of Alzheimer's disease. We are now working towards this aim. Once we have this information, we will be in a position to devise new therapeutic strategies that can modulate recycling."

More information: Aß40 and Aß42 Amyloid Fibrils Exhibit Distinct Molecular Recycling Properties, J. Am. Chem. Soc., 2011, 133 (17), pp 6505–6508. DOI: 10.1021/ja1117123

A critical aspect to understanding the molecular basis of Alzheimer’s disease (AD) is the characterization of the kinetics of interconversion between the different species present during amyloid-ß protein (Aß) aggregation. By monitoring hydrogen/deuterium exchange in Aß fibrils using electrospray ionization mass spectrometry, we demonstrate that the Aß molecules comprising the fibril continuously dissociate and reassociate, resulting in molecular recycling within the fibril population. Investigations on Aß40 and Aß42 amyloid fibrils reveal that molecules making up Aß40 fibrils recycle to a much greater extent than those of Aß42. By examining factors that could influence molecular recycling and by running simulations, we show that the rate constant for dissociation of molecules from the fibril (koff) is much greater for Aß40 than that for Aß42. Importantly, the koff values obtained for Aß40 and Aß42 reveal that recycling occurs on biologically relevant time scales. These results have implications for understanding the role of Aß fibrils in neurotoxicity and for designing therapeutic strategies against AD.

Provided by American Chemical Society (news : web)

Simple method of dealing with harmful radioactive iodine discovered

A novel way to immobilise radioactive forms of iodine using a microwave, has been discovered by an expert at the University of Sheffield.

Iodine are produced by of uranium fuel in a . is of concern because it is highly mobile in the environment and selective uptake by the can pose a significant following long term exposure. Furthermore, iodine-129, which is a type of radioactive iodine, has an extremely long half life of 15.7 million years, so is one of the most significant long term hazards faced by the population due to its emission during the geological disposal of nuclear waste.

Professor Neil Hyatt, from the University's Department of Materials Science and Engineering, has now found a way of locking up iodine radioisotopes in a durable, solid material suitable for ultimate disposal, like lead iodovanadinite(Pb5(VO4)3I). The research, which was published in the Journal of , demonstrates how his simple, inexpensive and rapid method can be done at .

Professor Hyatt and his team created a solid material for immobilisation of iodine with the formula Pb5(VO4)3I, by heating a mixture of lead iodide, lead oxide and vanadium oxide.

Previously, this has only been achieved using high pressure and a sealed container, because iodine is volatilised at high temperature. However, using the knowledge that vanadium is a good absorber of microwaves at 2.45 GHz – the frequency used in domestic microwave ovens – the team were able to heat the mixture of chemicals in a microwave oven to produce Pb5(VO4)3I in about three minutes.

The key to the method's success is that Pb5(VO4)3I is a poor of 2.45 GHz microwaves, so once this is formed, the sample cannot absorb microwaves, so the temperature does not get high enough for the iodine to volatilise.

Iodine-131 was the harmful gas emitted from the Fukushima power plant in Japan following the earthquake and tsunami last month, and was a significant contributor to the health effects from open-air atomic bomb testing in the 1950s, and was also emitted during the Chernobyl disaster. It is hoped the new research will reduce the public health impact associated with the release of radioactive iodine to the environment by providing a simple and inexpensive method of immobilisation in a solid material, which could be rapidly deployed in an accident scenario.

Professor Neil Hyatt, said: "In spent nuclear fuel, the iodine is not immobilised, so once the containment is breached it simply gets dispersed. At present, iodine-129 released by nuclear fuel reprocessing is discharged direct to the Irish Sea off the coast of Sellafield. Substantial quantities of this radioisotope were also released into the sea off the coast of Japan in the Fukushima incident. Our new method offers a way of safely and rapidly containing this radionuclide, reducing the potential long term impact on human health from discharge to the environment."

More information: Rapid synthesis of Pb5(VO4)3I, for the immobilisation of iodine radioisotopes, by microwave dielectric heating, doi:10.1016/j.jnucmat.2011.04.041

Rapid synthesis of Pb5(VO4)3I, a potential immobilisation host for iodine radioisotopes, was achieved in an open container by microwave dielectric heating of a mixture of PbO, PbI2, and V2O5 at a power of 800 W for 180s (at 2.45 GHz). The resulting ceramic bodies exhibited a zoned microstructure, differentiated by inter-granular porosity and phase assemblage, as a consequence of the inverse temperature gradient characteristic of microwave dielectric heating. Liquid PbI2 within the interior of microwave processed ceramics assisted formation of Pb5(VO4)3I, and reduced inter-granular porosity. In contrast, the exterior of microwave processed ceramics comprised poorly sintered Pb5(VO4)3I with the presence of minor reagent relics. Quantitative microanalysis, electron diffraction and Rietveld analysis, confirmed the synthesis of stoichiometric Pb5(VO4)3I within precision. The crystal structure of Pb5(VO4)3I was found to adopt space group P63/m with a = 10.4429(3) A and c = 7.4865(2) A.

Provided by University of Sheffield

'Sweet wheat' for tastier and more healthful baking

"Sweet wheat" has the potential for joining that summertime delight among vegetables — sweet corn — as a tasty and healthful part of the diet, the scientific team that developed this mutant form of wheat concludes in a new study. The report appears in the ACS' Journal of Agricultural and Food Chemistry.

Just as sweet corn arose as a mutation in field corn — being discovered and grown by Native American tribes with the Iroquois introducing European settlers to it in 1779 — sweet wheat (SW) originated from mutations in field wheat. Toshiki Nakamura, Tomoya Shimbata and colleagues developed SW from two mutant types of wheat that each lack a different enzyme needed to make starch. Because the new wheat has much more sugar than regular wheat, they called it "sweet wheat." To see whether the flour from this new wheat could be used as an ingredient in foods, such as breads and cakes, the researchers analyzed its components.

They found that SW flour tasted sweeter, and SW seeds and flour contained higher levels of sugars, lipids and dietary fiber than seeds and flours of other wheat varieties. "The specific compositional changes that occurred in SW seed suggest that SW flour may provide health benefits when used as a food ingredient," say the researchers, noting its high levels of healthful carbohydrates termed fructans.

More information: High Levels of Sugars and Fructan in Mature Seed of Sweet Wheat Lacking GBSSI and SSIIa Enzymes, J. Agric. Food Chem., 2011, 59 (9), pp 4794–4800. DOI: 10.1021/jf200468c

Sweet wheat (SW), which lacks functional granule-bound starch synthase I (GBSSI) and starch synthase IIa (SSIIa), accumulates high levels of free sugars in immature seeds. Here, we examined the effects of the lack of these two enzymes on mature kernel composition. Whole grain flour of SW had higher levels of sugars, particularly maltose, slightly higher ash and protein content, approximately two to three times higher lipid levels, and about twice as much total dietary fiber as parental or wild-type lines. Considerably higher levels of low-molecular-weight soluble dietary fiber (LMW-SDF), largely consisting of fructan, were also detected in SW. Although there were no differences in total amino acid levels, the free amino acid content of SW was approximately 4-fold higher than that of wild type, and the levels of certain free amino acids such as proline were particularly high. Thus, we were able to clearly demonstrate that the lack of GBSSI and SSIIa caused dramatic changes in mature seed composition in SW. These compositional changes suggest that SW flour may provide health benefits when used as a food ingredient.

Provided by American Chemical Society (news : web)