Chemistry

Scientists have inventoried and categorized all of Earth's rare mineral species described to date, each sampled from five or fewer sites around the globe. Individually, several of the species have a known supply worldwide smaller than a sugar cube.

These 2,550 minerals are far more rare than pricey diamonds and gems usually presented as tokens of love. But while their rarity would logically make them the most precious of minerals, many would not work in a Valentine's Day ring setting. Several are prone to melt, evaporate or dehydrate. And a few, vampire-like, gradually decompose on exposure to sunlight.


Fibres from the Australian native spinifex grass are being used to improve latex that could be used to make condoms as thin as a human hair without any loss in strength.

Working in partnership with Aboriginal traditional owners of the Camooweal region in north-west Queensland, the Indjalandji-Dhidhanu People, researchers from The University of Queensland have developed a method of extracting nanocellulose -- which can be used as an additive in latex production -- from the grass.

Professor Darren Martin from UQ's Australian Institute for Bioengineering and Nanotechnology (AIBN) said the spinifex nanocellulose significantly improved the physical properties of latex.


It may be time to embrace DDT again. New findings from the National Institute of Allergy and Infectious Diseases (NIAID) confirm dihydroartemisinin-piperaquine, the first-line treatment for Plasmodium falciparum malaria infection in Cambodia, has failed in certain provinces due to parasite resistance to artemisinin and piperaquine.


Diabetes is one of the leading causes of death. Patients with type 1 diabetes have their insulin secreting cells destroyed by the immune system and require daily insulin injections. Pancreatic islet transplantation is an effective treatment that can dramatically reduce daily doses or even eliminate dependence on external insulin. Insulin producing cells are injected into a recipient liver and after an adaptation period they start to produce sufficient hormone needed by diabetic patients.

Groundwater in Bangladesh, Cambodia, India, Myanmar, Vietnam and China commonly contains concentrations of arsenic 20 to 100 times greater than the World Health Organization's recommended limit, resulting in more than 100 million people being poisoned by drinking arsenic-laced water. Now scientists have found where the microbes responsible for releasing dangerous arsenic into groundwater in Southeast Asia get their food. 


Chemical triggers that make plants defend themselves against insects could replace pesticides, according to a new paper in Bioorganic&Medicinal Chemistry Letters which identifies five chemicals that trigger rice plants to fend off a common pest - the white-backed planthopper, Sogatella furcifera


A team of Belgian researchers has shown that the yeasts used to ferment cocoa during chocolate production can modify the aroma of the resulting chocolate. "This makes it possible to create a whole range of boutique chocolates to match everyone's favorite flavor, similar to wines, tea, and coffee," says Jan Steensels, a postdoctoral researcher at the University of Leuven, and the Flanders Institute for Biotechnology, Belgium.  


There is some good news for consumers with a sweet tooth. Cornell food scientists have reduced the sweetener stevia's bitter aftertaste by physical - rather than chemical - means.

Cornell professor of food process engineering, Syed Rizvi, co-authored the research "Controlling the Taste Receptor Accessible Structure of Rebaudioside A via Binding to Bovine Serum Albumin," with Samriddh Mudgal, the lead author and former graduate student in Rizvi's lab at Cornell; Ivan Keresztes, director of Cornell's NMR facility in the Department of Chemistry and Chemical Biology, and Gerald W. Feigenson, professor of biochemistry, molecular and cell biology.


Researchers have set out to solve the mystery of a degenerative sign of aging in concrete: the alkali-aggregate reaction (AAR), where a material forms that takes up more space than the original concrete and thus gradually cracks the concrete from within as the decades go by.

The researchers have now explored the exact structure of this material. They managed to demonstrate that its atoms are arranged extremely regularly, making it a crystal. They also showed that the structure of this crystal is a so-called sheet-silicate structure. This specific structure had never been observed before. 


A global problem




In what might be a new breakthrough for the spider-control field, researchers have found that oil-based pesticides are more effective than water-based pesticides at killing the contents of brown widow spider egg sacs.

This finding is important because trying to control adult spiders without controlling their eggs is like plucking dandelions without taking out their roots.


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This image shows a brown widow spider. Credit: Rick Vetter