Spectroscopy – Page 16 – David Bradley

Nervous analysis

Chemical communication between nerve cells underlies brain functions, such as the control of sensory and motor processing, memory and learning. Monitoring neurotransmitter secretion is crucial to studying and understanding how the brain works. Various research teams have endeavoured to develop techniques for monitoring neurotransmitter release at the single-cell level, according to researchers in The Netherlands only invasive methods such as electrophysiological techniques and fluorescent probe labelling have provided adequate temporal and spatial sensitivity. These limits suffer from being limited to specific analytes.

Now, the researchers have turned to a specialist spectroscopic technique to develop a new approach to monitoring neurotransmitters that is non-invasive and side-steps the issue of analyte limitations.

Read the complete story in SpectroscopyNOW.com

High performance spectroscopy

High performance liquid chromatography (HPLC) is usually the technique of choice for separating and analysing complex mixtures of small molecules in laboratories around the globe. As such, a whole range of specialist materials for particular types of analyte have been developed. French researchers, however, have now developed a novel approach to separation and analysis based on NMR that uses a simple solid support, such as porous silica gels.

Guilhem PagÃ¨s, Corinne Delaurent, and Stefano Caldarelli of the University of Provence and Paul CÃ©zanne in Marseille, France, recently developed an alternative for identifying components in a mixture that avoids the complexities of chromatography and relies instead on solid-enhanced diffusion-based NMR.

“The determination of the components of assemblies of small molecules is an extremely common task in chemical labs,” the researchers say. A method that mimics part of the chromatography process can they explain achieve good separation for certain types of common mixture but using only very simple chromatographic materials, which not only simplifies the analytical process but is far less expensive than employing sophisticated materials.

More…

Photochemistry without light

Infrared and nuclear magnetic resonance spectroscopy are anything but child’s play, but now US chemists have used these techniques to follow the chemistry of “light sticks” and to develop a light-free version of photochemistry. This contradiction in terms could be exploited in a remote cure process for photopolymers, they say, allowing inaccessible cracks in pipes, joints or containers, to be sealed as well as having other practical applications in coatings, paints, varnishes, adhesives and sealants.

Light sticks hold children’s parties in awe with their eerie yellow-green glow as well as providing emergency lighting without electricity or a naked flame. The chemistry taking place when the stick is “snapped” and the materials mix involves oxalyl chloride and hydrogen peroxide reacting in the presence of a fluorophore, which emits light as the reaction proceeds.

Read the full story in the latest news round up from David Bradley on SpectroscopyNOW.com

An elephant task

The ivory trade was banned by CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora) in 1989. However, illegal trade continues and as such researchers in India suggest that there is a continued need to characterize Asian elephant ivory and to be able to compare it with African ivory so that national and international laws can be implemented more effectively.

Previously, Erich Raubenheimer and colleagues in the Department of Oral Pathology, Medical University of Southern Africa, established an ivory database that would allow law enforcers to trace the source of illegal ivory and so identify poorly managed game parks, particularly in Africa. However, the ivory of Asian elephants, of which half are found in India, is more prized than African ivory. It is only the males of the Asian elephant that has tusks and they are much smaller than those of its African counterpart. Despite the illegal price differential between continents, the ivory of African and Asian elephants is indistinguishable in superficial appearance, particularly once processed, so it is almost impossible to trace the origin of tusks or a piece of work.

Read the elephant’s tale on spectroscopynow.com

Brazilians wax lyrical on food testing

Brazilian researchers have developed a method to analyse the metal ion content of food products by combining X-ray spectroscopy (XRS) with a partial least-squares (PLS) data treatment. Their approach promises to be faster, more widely applicable to a range of food and agricultural products, and less expensive than other methods.

Food quality control is critical to consumer safety and satisfaction. Knowing levels of inorganic analytes, such as the toxic elements arsenic, cadmium, chromium, and lead, is important, as is information on macro-nutrients like calcium, potassium, magnesium, sodium, phosphorus, and sulfur and micronutrients (copper, iron, manganese, and zinc).

Read the complete story in the latest science news round-up from David Bradley in Spectroscopynow.com

20 year model relieves stress

No…not that kind of model!

“The formation and evolution of dislocation cell structures (patterning) is one of the most important aspects of the deformation process in ductile metals,” according to Lyle Levine and colleagues at the National Institute of Standards and Technology (NIST), Oak Ridge National Laboratory (ORNL), and the University of Southern California. Metallurgists already know that this patterning process arises as clusters of dislocations interact with each other while recent diffraction-resolved studies have shown that the process is initiated by crystal lattice breakup. However, predicting exactly how a metal will behave under stress remains an unresolved problem. Now, Levine and his colleagues have turned to a twenty-year old model to help them out.

Read on…

Brain protein unlocked

A key protein linked to neurodegenerative diseases, such as Huntington’s and Alzheimer’s diseases, has been characterised using NMR by US researchers.

John Cavanagh, Douglas Kojetin, David Kordys, and Richele Thompson of North Carolina State University teamed with colleagues Ronald Venters of Duke University and Rajiv Kumar of the Mayo Clinic and Foundation have obtained a structure for the protein, calbindin-D28K. This protein modulates calcium levels by sequestering calcium from areas that have too much or serves as an on/off switch for further chemical reactions. It is found in the kidneys, pancreas, ocular nerve and large amounts are present in the brain. It is its role in the brain as a “bodyguard” against the action of the enzyme caspase-3 that links it to neurodegenerative diseases. By binding to and inhibiting caspase-3, calbindin D28K prevents the formation of damaging plaque and tangle formation in the brain, which are hallmarks of neurodegenerative disease. The structure of this key protein has remained elusive, until now.

Read on…

Pyridine joins the supersonic set

The pyridine chemical group, basically a benzene ring in which one of the six carbons and its attendant hydrogen atom have been swapped for a nitrogen atom, is one of the building blocks of a vast number of biological molecules and is a crucial component in the functionality of an almost as expansive selection of pharmaceuticals. As such, understanding its chemistry and physical properties are important in a fundamental way to the chemical and life sciences.
Now, chemists Yoshinori Nibu, Ryosuke Marui, and Hiroko Shimada of Fukuoka University, in Japan, have used infra-red spectroscopy to sniff out important new clues as to this aromatic compound’s behaviour.

You can read the full story in the first August edition of my science news round-up for spectroscopyNOW.com

Light Harvest for the World

In order to trap the energy from sunlight antenna plants construct chlorophyll groups through chemical self-assembly in a highly ordered manner. Emulating this system would not only improve our understanding of how plants function so effectively but could also lead to new materials for harvesting solar energy as an alternative to silicon-based photovoltaic devices.

Researchers have exploited long-range chemical order to creating aggregate compounds that can either trap light or transfer energy. Now, Tsutomu Ishi-i and Shuntaro Mataka of the Kurume National College of Technology and their colleagues have synthesised a new type of light harvester and by incorporating different materials into the aggregate structure they can induce energy transfer too. UV-Vis spectroscopy and other techniques were used to reveal the details of this novel group of artificial self-assembling light-harvesting compounds that will help us understand plant photosynthesis and may eventually lead to an alternative to semiconductor-based solar panels.

I offer a light report via SpectroscopyNOW

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Recycling Plastics Sorted

recycling plastic Plastic waste is a mess. Disposal in landfill is the worst option but recycling post-consumer plastic waste presents a technological nightmare given the huge range of polymers used in packaging and products. A rapid, online method of identifying the different plastics in a recycling stream would provide a way to sort them and allow recycling plants to operate far more efficiently and perhaps make plastic recycling commercially viable.

A technique being investigated by Spanish researchers to this end is laser-induced plasma spectroscopy (LIPS). JesÃºs Anzano, MarÃa-Esther Casanova, MarÃa-Soledad BermÃºdez, and Roberto-JesÃºs Lasheras of the Laser Analytical Spectroscopy Lab at the University of Zaragoza, in Spain, have now demonstrated that LIPS used in conjunction with a simple statistical correlation method can indeed differentiate between plastics prior to recycling.

Recycle the full story here