Spectroscopy – Page 15 – David Bradley

Parkinson symptoms

The common perception of Parkinson’s disease is of a disorder that leads to problems with movement, tremors, involuntary spasms, and a shuffling gait. However, functional MRI has now confirmed that the disease can also cause widespread abnormalities in the sense of touch and vision for sufferers. An international team from the US and China presented their findings at the Society for Neuroscience meeting in Atlanta on October 17.

Research into Parkinson’s disease has previously focused mainly on the brain’s motor and premotor cortex, sidestepping the somatosensory and the visual cortex because the most prominent symptoms are associated with movement and not the senses. However, neurologist Krish Sathian of Emory University and colleagues discovered through tests of tactile ability, that PD patients also have sensory problems with touch. The researchers recently designed a study using fMRI to investigate this earlier finding and to ascertain whether or not changes in the brain underly these sensory abnormalities.

Read on…

Moss side analysis

A bag of moss lying in an irrigation ditch in North East Italy does not conjure up a picturesque image nor the cutting edge of analytical science but nevertheless the special characteristics of the moss Rhynchostegium riparioides make it the ideal environmental monitor according to researchers at the University of Trieste and their colleagues at ARPAV.

Waterways are often intermittently polluted by metals from industrial outflows and other sources. Such waterways are often used in rural parts for agricultural irrigation. The phenomenon is frequent in the Veneto Region of Northeast Italy, according to biologists M. Cesa, F. Fumagalli, and Pier Nimis at Trieste and Alessandro Bizzotto and C. Ferraro of the Vicenza ARPAV Italy.

You can read the complete story in my SpectroscopyNOW news round-up this week.

Trapped particles and solar energy

Spanish researchers have trapped tiny clusters of titania in the pores of zeolite. They hope to develop a new class of photovoltaic material for solar energy conversion. Ultimately, zeolite-entrapped titania will be less expensive to manufacture, tougher, and more efficient than conventional silicon-based materials.

Titania-based photovoltaics are soon to enter the solar energy market but they suffer from several drawbacks. For instance, the small size of the particles used to make the light-sensitive layer means that they are not highly electrically conductive. Moreover, at less than a few nanometres, titania particles can only be activated by deep ultraviolet light and so don’t exploit the full spectrum of sunlight. Hermenegildo GarcÃa of the Polytechnic University of Valencia and colleagues hope to change all that, Although they need to improve the photo efficiency of their materials by at least an order of magnitude, the adaptability of zeolites means this should be possible.

Read on…

2, 4, 6, 8 – team oxygen

Nature described this finding as “surprising, elegant, and entirely useless”. Well, the journal is half right. Solid elemental oxygen is not thought to exist anywhere on earth or even elsewhere in the universe under the immense pressures created by Malcolm McMahon and Paul Loubeyre. They and their colleagues put the squeeze on solid oxygen, which forms deep red crystals at above a million atmospheres. They used various techniques to determine the structure of this new material and found that oxygen atoms team up to form clusters of eight in the solid. A seemingly esoteric discovery you might think.

However, the new understanding gained of materials under pressure could lead to new efficient rocket fuels or superhard materials formed from oxygen, nitrogen, or carbon that beat diamond for toughness.

Moreover, the results suggest that hydrogen might also form metallic crystals of a similar nature to solid oxygen at 450 gigapascals (4.5 million times terrestrial atmospheric pressure). Such pressures exist at Jupiter’s core astronomers think. Under these conditions metallic hydrogen may behave as an exotic superconductor or superfluid. That finding may be elegant, certainly no longer surprising, but too perhaps even more useless!

Read the full story in SpectroscopyNOW.com

Extra virgin solvents

Olive Oil Extracting oil from olives requires solvents and residues of halogenated solvent can sometimes leave a toxic taint in the product. European Union rules restricted the acceptable levels of these residues for the sake of public health but new sensitive and precise analytical procedures are needed to allow strict quality control and regulatory testing to be carried out.

Now, Spanish researchers have turned to chemical informatics to help them optimise the extraction-analysis process. Bromoform, chloroform, ethylene dichloride, trichloroethene, tetrachloroethene, dibromochloromethane, and bromodichloromethane are all employed to extract crude olive-pomace oils from the solid residue obtained in the pressing of olive oils. The EU limits the residues of these solvents to 0.1 milligram per kilogram for individual compounds and double than that for total content. “These solvents have a great negative influence on both the quality of oils and human health,” JosÃ© Luis GÃ³mez-Ariza of Huelva University told SpectroscopyNOW, “They are all considered to be possible carcinogens and, therefore, human exposure to such compounds should be minimized.”

Making light of spectroscopy

A radically different approach to detecting the way atoms resonate in a magnetic field could improve the sensitivity of NMR spectroscopy, according to US scientists.

Conventional liquid and solid relies on detecting the net dipolar magnetic field outside a spin-polarised sample, explain Michael Romalis and colleagues at Princeton University, New Jersey. However, this only offers the NMR spectroscopist limited structural and spatial information. As such NMR has been extended with elaborate techniques involving magnetic field gradients and spin correlations. Using a laser beam, which is by definition a polarised light source has provided a new avenue of research – optical NMR. However, until now, this has been limited to quantum dots and other specialists materials. Romalis and his colleagues hoped to extend optical NMR to a much wider field of research.

Find out more in the latest news round-up on spectroscopynow.com

Spanish heavy metal

Spanish scientists have used some tricky mathematics to help them work out where heavy metal comes from. Their findings, based on atomic analysis, will provide information useful in protecting us from these toxic elements.

Contamination of soils with heavy metal contaminants has become and increasingly important environmental issue, particularly in developed countries because of shifting land-use patterns. Such contaminants readily leach into water systems or are assimilated by certain crops with putatively detrimental effects on wildlife, livestock and human health. Understanding the role of soil type, organic content, clays and salts, such as carbonates, is essential to characterising the risks and developing a soil protection policy. Indeed, the European Thematic Strategy for Soil Protection requires the characterization of the content and source of heavy metals in soils so that quality standards can be established.

Read on…

Scanning vegetative patients

Last week, Cambridge and Belgian researchers reported that they could observe almost identical brain activity in healthy volunteers as a patient purportedly in the persistent vegetative state following emergence from a coma (the patient was originally in a car crash in July 2005). The implications of this functional MRI work are that some (but by no means all) PVS patients may have consciousness to some degree despite their outwardly appearing inanimate.

It is incredibly tragic to imagine that there might be PVS patients who do have some consciousness but cannot move or communicate with the outside world. Functional MRI may in the long-term lead to a way to communicate with such patients.

That said, there is a long way to go before fMRI or any other technique can provide us with a full understanding of the persistent vegetative state and some researchers are cautious of extrapolating the Cambridge findings too far. Indeed, if you read my report about the research in the latest issue of SpectroscopyNOW.com, you can see quite clearly that the fMRI scan of the control volunteer and the patient are superficially similar – activity is in the same region, after all – but the level of activity appears to be markedly less prominent in the patient. This could have important implications for what is meant by such a patient having consciousness as we know it.

Much more research is now needed to help us redefine the PVS. This is perhaps a matter of some urgency given the current definition of PVS states that these patients cannot experience pain and suffering as these are attributes of consciousness.

Branching out into optics

Dendrimeric molecules are multiply branched compounds that chemists have investigated keenly for their potential applications in medical diagnostics, molecular recognition, catalysis, and photoactive device engineering. Now Mark Humphrey of the Australian National University in Canberra and colleagues have developed organometallic versions of these compounds that are more stable than others. They investigated alkynylmetal complexes because of their potential to form materials with non-linear optical characteristics. Novel NLO materials will be crucial for the generation of opto-electronic computational and communications devices as well as in new types of sensor protection from laser threats.

Read on…

Crystallising thoughts on bird flu

UK researchers have determined the X-ray structure of a key protein of the avian influenza virus that reveals a peculiarity that might prove the Achilles’ heel of bird flu and allow new potent drugs against the disease that could stave off a flu pandemic.

H5N1 virus is named for the particular haemagglutinin (H) and neuraminidase (N) proteins that are found on the viral coat. Haemagglutinin allows the viral particles to bind to and infect host cells, while neuraminidase helps the virus to escape infected cells and attack new ones. There are 16 H’s and 9 N’s in known variants on the influenza type A virus.

It is the neuraminidases that are the target for drugs such as oseltamivir (Tamiflu) and zanamivir (Relenza). The trouble is, N1 is not the exact target for which they were designed. Rather the design of these drugs was based on neuraminidases N2 and N9 found in other influenza type A strains. H5N1 itself resides in a genetically distinct group. Structural information from this group could be critical to producing drugs that are resistant to emerging resistance in influenza.

Read the full story in my latest news round up at spectroscopynow.com