ChemWeb Newsletter

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what's new on ChemWeb

ChemWeb is pleased to welcome Bentham Science Publishers as our newest contributor to the ChemWeb Journal Abstracts Index, a free, full-text searchable database of chemistry journal abstracts. An international STM publisher of 79 titles, Bentham Science answers the information needs of the pharmaceutical, bio and medical research communities. Leading journals include Current Pharmaceutical Design, Current Medicinal Chemistry, Current Drug Targets, and Current Topics in Medicinal Chemistry. ChemWeb users can perform free full text search of abstracts from year 2006 to the present, with prior years to be added to the index soon. A complete list of Bentham journals can be found on the ChemWeb site here. With this new addition, ChemWeb now provides free full text abstract search of almost 300 chemistry related journals.



overview

This week geochemical biomarkers are rewarded for pioneering our historical understanding of climate change, while a seemingly paradoxical polymer emerges from mathematics to help compute future optical chips. Also in news this week, a Titanic effort reveals the chemical nature of the smog that shrouds one of Saturn's moons and the stickiest of sticky materials could bond disparate materials such as copper and silica tighter than ever before. At least one dyed in the wool media health scare story has been cut short this month with the discovery that chemical relaxers, used by African-American women to straighten their hair, do not cause breast cancer. Finally, new forensic information can now be dabbed from fingerprints thanks to research carried out in the UK. Antibody assays carried out on fingerprints can now be used to tell if an unidentified suspect smokes, whether they use drugs, or even if they have an illness.




The use of biomarkers to detect climate change is revolutionizing the emerging field of biogeochemistry and led to the award of the Vernadsky Medal to Dutch scientist Jaap Sinninghe Damsté for his pioneering work. "It's an honor to win this prize because it is recognition of my science and that it has a certain impact," said Sinninghe Damsté. Biomarkers are organic compounds found in sediments. "Biomarkers open new perspectives on all kinds of things," says Sinninghe Damsté, "they not only give the information that a certain organism was present but also tell us about past climatic conditions," he adds.





Quasicrystals are "not quite" regular. They have repeats, sure, but no infinitely repeating pattern emerges. Researchers have spotted them in metals and other materials, and whole books have been written to explain their mathematical properties and reputations rest on so-called Penrose tiling, the non-periodic crystalline structures observed in such materials and elsewhere in nature. Now, Tomonari Dotera of Kyoto University and Yushu Matsushita of Nagoya University in Japan and their colleagues have added polymers to the list of organic compounds that dissolve to form liquid quasicrystalline structures. According to Dotera, their QC polymers are of a size that could lead to new types of photonic crystals, structures that will manipulate light in future devices, such as optical logic gates.





UK scientists have identified the molecules in the atmosphere of Saturn's largest moon, Titan, that give rise to its hazy smog-like atmosphere. Data collected using the Cassini plasma spectrometer and a UK-run onboard electron spectrometer have picked out a surprising cloud of very heavy organic ions 1000 km above Titan's surface, some of which have masses of up to 8000 Daltons. Ions of 80-350 Daltons are thought to form from photochemically from atmospheric methane and nitrogen and include polycyclic aromatic hydrocarbons (PAHs) and related compounds containing nitrogen. The much larger 8000 Dalton compounds have been identified as heteropolymers called tholins.





An inexpensive adhesive material can bond together almost any two materials according to researchers at Rensselaer Polytechnic Institute. Ganapathiraman Ramanath and colleagues investigate self-assembled molecular nanolayers (MNLs) composed of short organic chains and terminated with desired functional groups. They point out that MNLs are attractive for modifying surfaces in lubricant applications, nanolithography, corrosion protection, and in the crystallization of biominerals. Their particular aim is to create stronger bonds between copper components and a silicon dioxide substrate for improved chip technology. Normally, attempting to anneal such an adhesive at 400 Celsius would lead to its break down, but Ramanath and his colleagues found that because the nanoglue was tightly sandwiched between the copper and silica vaporization was not possible and the bond between the layers simply tightened with rising temperature.





Scare stories in the media linking hair-straightening chemicals known as "relaxers" have been found not to be associated with an increased risk of developing breast cancer among African-American women. A study that followed almost 50000 participants in the Black Women's Health Study is reported in the May issue of Cancer Epidemiology, Biomarkers & Prevention and shows no correlation between relaxer use or frequency. Lynn Rosenberg of Boston University and colleagues showed that women using relaxers seven or more times a year over a twenty-year span or longer had the same risk as women who used the chemicals for less than a year, researchers say. Hair relaxers are not fully monitored by the Food and Drug Administration, according to Rosenberg, proprietary ingredients are often excluded from the packaging. Different products and brands may contain ammonium thioglycate, calcium hydroxide, or other alkalis as the active ingredients.





David Russell and colleagues at the University of East Anglia, Norwich and King's College London, England, have developed an analytical antibody assay that can differentiate between the fingerprints of smokers and non-smokers. Their approach is proof of principle that investigators might soon be able to use fingerprints not only to match suspects to their forensic database, but also home in on a person's lifestyle on the basis of the chemical fingerprint of their fingerprints. This could be especially useful in narrowing a pool of suspects if no fingerprint matches are found in the database. The researchers say fingerprint might now be used to identify drug use, medications, food handle, or even whether or not the individual in question has a particular disease. The latter could be equally as useful to forensics as medical diagnostics.