Chemistry

By Ian Musgrave, Senior lecturer in Pharmacology at University of Adelaide.

A paper has just been released that will raise health concerns about Bisphenol A again. The paper, “Low-dose exposure to bisphenol A and replacement bisphenol S induces precocious hypothalamic neurogenesis in embryonic zebrafish” was published in the Proceedings of the National Academy of Sciences. This is a very interesting paper, but in terms of implications for human health everything hinges on what “low dose” means.

Bisphenol A, known as BPA, is in the middle of an environmental culture war and a hurriedly-rushed replacement, Bisphenol S (BPS), is just as big a concern.

We need plastic, food items are covered in plastic to make them last longer and protect them from microbes, but we know that plastic bottles and films take between 100 and 400 years to degrade, so the quest for alternative materials to plastics has been ongoing. That means we should not rush to embrace things just because they are 'not BPA', which still has no evidence of harm (unless hyperactive zebrafish count).



Image: Jeff Kubina via flickr, CC BY 

BY Jyoti Madhusoodanan, Inside Science 

(Inside Science) -- Showers fall to Earth’s surface as rain, snow, sleet or hail. But high in the clouds, water molecules often begin to come together as tiny ice crystals that form around miniscule particles of dust. The microscopic crystals are big players in creating rain and lightning, and also heat and cool the planet by bouncing sunlight off clouds.

A new study finds that fructose is bad.  Biologists who fed mice sugar in doses proportional to what many people eat found that the ratio of fructose and glucose in high-fructose corn syrup was more toxic than than random variations found in sucrose (table sugar). They conclude that the precisely-determined fructose reduced both the reproduction and lifespan of female rodents. 


Current carbon capture schemes are not really ready for prime time, plagued by toxicity, corrosiveness and inefficiency, but a team of chemists have invented low-toxicity, highly effective carbon-trapping "sponges" that could lead to increased use of the technology.

Used in natural gas and coal-burning plants, the most common carbon capture method today is called amine scrubbing, in which post-combustion, carbon dioxide-containing flue gas passes through liquid vats of amino compounds, or amines, which absorb most of the carbon dioxide. The carbon-rich gas is then pumped away - sequestered - or reused. The amine solution is extremely corrosive and requires capital-intensive containment.



When looked at the right way, even cement can be beautiful. This is the crystal structure of tricalcium aluminate, a vital mineral in cement.

By Helen Maynard-Casely, Australian Nuclear Science and Technology Organisation

Dietary masochists say you should endure the most difficult brown bread imaginable because 1,000 years ago people had no choice. It's vaguely healthier, we are all told, though if you read more than a few epidemiology studies and saw the lack of methodology you know it casts on doubt almost every health claim made by matching populations to specific foods, not to mention the bizarre beliefs promoted by prominent nutrition 'experts'.

Researchers using a new chemical process have converted the cellulose in sawdust into hydrocarbon chains, building blocks for gasoline.

 Cellulose is the main substance in plant matter and is present in all non-edible plant parts of wood, straw, grass, cotton and old paper.  These hydrocarbons can be used as an additive in gasoline or as a component in plastics. 

"At the molecular level, cellulose contains strong carbon chains. We sought to conserve these chains, but drop the oxygen bonded to them, which is undesirable in high-grade gasoline. Our researcher Beau Op de Beeck developed a new method to derive these hydrocarbon chains from cellulose," explains Professor Bert Sels.