ALU

Chemistry

For the best dough, add white wine and lemon juice

Bakers and home cooks despair when their dough turns brown. Now scientists have found a cheap and easy way to prevent it. Samantha Page reports. Original Link

Science history: The merchant of death who commemorated peace

Alfred Nobel made explosives and armaments. His will revealed a desire to reward human goodness. Jeff Glorfeld reports. Original Link

Chemical compound moves from herbicide to hospital

Early research suggests a weed-killer could help fight fungal infections. Nick Carne reports. Original Link

Science history: The man who made better beer and better vaccines

Louis Pasteur’s name passed into common usage, where it remains today. Jeff Glorfeld reports. Original Link

Nobel Chemistry prize award for “harnessing the power of evolution”

Joint award recognises the creation of tools to make powerful new proteins.Marco Alcocer reports. Original Link

Linus Pauling: The man who won two Nobel Prizes

Linus Pauling was a towering figure in chemistry, quantum mechanics, peace activism – and, um, vitamin therapy. Original Link

This week in science history: A pioneering biochemist and feminist dies

Ruth Hubbard was the first female biologist appointed to Harvard. It changed her life. Jeff Glorfeld reports. Original Link

Chemists say watering down whisky improves the taste

Science has confirmed that the whisky purists are right. Nick Lucas explains. Original Link

22 questions for a less toxic planet

Unchecked chemical-based environmental pollution threatens our supplies of food, water and energy, damages human health, leads to biodiversity loss, and heightens the advance of climate change and associated extreme weather, according to an international consortium of experts working under the auspices of the Society of Environmental Toxicology and Chemistry (SETAC). What’s more, research and regulatory bodies around the world fail to understand the magnitude of the problem.

The SETAC team has called for urgent action in establishing a fundamental change to the way we study and communicate the impacts and control of chemicals in the natural environment.

Their report, published in the journal Environmental Toxicology and Chemistry, has identified 22 research questions that matter the most to the broad community so that research and regulatory efforts can be applied to the most pressing problems.

The report centres on the United Nations’ 2030 Agenda for Sustainable Development, and its 17 sustainable development goals, which came into force in 2016 and aims to end poverty, protect the planet and ensure prosperity for all, and which depends for its success on a healthy and productive environment.

Although the report is European-based, its authors took input from SETAC members in Africa, the Asia Pacific region, Europe, Latin America and North America.

The report says many questions need to be addressed about the risks of chemicals in the environment, “and it will be impossible to tackle them all”.

“There is therefore an urgent need to identify the research questions that matter most to the broad community across sectors and multiple disciplines so that research and regulatory efforts can be focused on the most pressing ones.”

Our understanding of how chemicals affect the environment and human health is still poorly developed, the report says. For example, most research and regulation considers the impacts of individual substances, yet in the real environment chemicals are present with hundreds or thousands of other substances and influencing agents.

Studies to support research and regulation tend to focus on single species rather than populations and communities. Variations in the nature of the environment in time and space, which will affect chemical influence, are hardly accounted for in research and risk assessments.

“Considering chemicals in isolation can result in a simplistic assessment that doesn’t account for the complexity of the real world,” says one of the study’s lead authors, Alistair Boxall, from the University of York, in Britain.

“A fish won’t be exposed to a single chemical but to hundreds if not thousands of chemicals,” he says. “Other pressures, such as temperature stress, will also be at play, and it is likely that these components work together to adversely affect ecosystem health.”

The report says Europe faces significant challenges regarding the risk assessment and management of chemicals and other factors, which constrains the region’s ability to achieve sustainable development.

“This study is the first attempt to set a research agenda for the European research community for the assessment and management of stressor impacts on environmental quality,” it says. “The questions arising from this exercise are complex. To answer them, it will be necessary to adopt a systems approach for environmental risk assessment and management. In particular, it is important that we establish novel partnerships across sectors, disciplines, and policy areas, which requires new and effective collaboration, communication, and co-ordination.”

Boxall says studies similar to this one are being performed in North America, Latin America, Africa, Asia and Australasia. “Taken together, these exercises should help to focus global research into the impacts of chemicals in the environment.”

The researchers say they hope their study is a first step in a longer process. “The results of this project now need to be disseminated to the policy, business, and scientific communities. The output should be used for setting of research agendas and to inform the organisation of scientific networking activities to discuss these questions in more detail and identify pathways for future work.”

The 22 questions

  1. How can interactions among different stress factors operating at different levels of biological organisation be accounted for in environmental risk assessment?
  2. How do we improve risk assessment of environmental stressors to be more predictive across increasing environmental complexity and spatiotemporal scales?
  3. How can we define, distinguish, and quantify the effects of multiple stressors on ecosystems?
  4. How can we develop mechanistic modelling to extrapolate adverse effects across levels of biological organisation?
  5. How can we properly characterise the chemical use, emissions, fate, and exposure at different spatial and temporal scales?
  6. Which chemicals are the main drivers of mixture toxicity in the environment?
  7. What are the key ecological challenges arising from global megatrends?
  8. How can we develop, assess, and select the most effective mitigation measures for chemicals in the environment?
  9. How do sublethal effects alter individual fitness and propagate to the population and community levels?
  10. Biodiversity and ecosystem services: What are we trying to protect, where, when, why, and how?
  11. What approaches should be used to prioritise compounds for environmental risk assessment and management?
  12. How can monitoring data be used to determine whether current regulatory risk‐assessment schemes are effective for emerging contaminants?
  13. How can we improve in silico methods for environmental fate and effects estimation?
  14. How can we integrate evolutionary and ecological knowledge to better determine vulnerability of populations and communities to stressors?
  15. How do we create high‐throughput strategies for predicting environmentally relevant effects and processes?
  16. How can we better manage, use, and share data to develop more sustainable and safer products?
  17. Which interactions are not captured by currently accepted mixture toxicity models?
  18. How can we assess the environmental risk of emerging and future stressors?
  19. How can we integrate comparative risk assessment, life cycle analysis, and risk–benefit analysis to identify and design more sustainable alternatives?
  20. How can we improve the communication of risk to different stakeholders?
  21. How do we detect and characterise difficult‐to‐measure substances in the environment?
  22. Where are the hotspots of key contaminants around the globe?

Original Link

Making molecules stand up

It’s a longstanding dream of chemists to be able to manipulate individual molecules, orientating them in three dimensions and bringing them together in specific ways. In a new study published in the journal Nature, a German team reveals it has done just that: lifting a single flat molecule up onto its edge.

Synthesising complex molecules is sometimes likened to building structures using Lego. Chemists take smaller molecules and “click” them together to make larger ones with particular properties.

In reality, though, the process is more like building with Lego blocks that you can’t hold. All you can do is mix together bags of different pieces, relying on their natural preference to join together in specific ways. In many ways, it’s a wonder that chemists are able to make the complex molecules that form our drugs and materials as efficiently as they do.

Since the 1980s, it has been possible to image and even manipulate individual atoms and molecules on a surface, using scanning probe microscopy. Unlike light microscopy and even electron microscopy, scanning probe microscopy is not limited by diffraction, and can achieve much higher resolutions. This is because the microscope uses a tiny physical probe, often with a single-molecule tip, to scan the surface of an object.

In a landmark 1990 study, IBM scientists were able to spell out their company logo using individual xenon atoms. But xenon atoms are large and spherical, so the task was easy compared to the daunting task of controlling organic molecules, which often have complex three-dimensional shapes.

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In recent years, scientists have made great progress in manipulating individual molecules on a surface, but controlling their 3D orientation remains elusive.

Now, a group from the Jülich Research Centre in Germany, led by Ruslan Temirov, has managed to flip a single, flat organic molecule on to its edge using the tip of a scanning probe microscope.

The small organic molecule, essentially a tiny fragment of graphene, normally lies flat on a silver surface. But by anchoring one end of it to the surface, and manipulating the other end with the microscope probe, the molecule was moved into an upright position.

“Until now, it was assumed that the molecule would revert back to its favoured position and lie flat on the surface,” says first author Taner Esat.

“But that is not the case. The molecule is surprisingly stable in the upright orientation. Even when we push it with the tip of the microscope, it does not fall over; it simply swings back up again. We can only speculate as to the reason for this.”

The team was able to show that the molecule displayed different electronic properties when upright, compared to its flat orientation. This could have applications in nano-scale electronics or in the generation of holograms.

The field of single-molecule fabrication still has a long way to go before we see complex nanostructures being assembled one atom at a time. But as this work shows, scientists, and molecules, are rising to the task.

Original Link

New from Lego: build your own nerve gas detector

One of mankind’s most simple and playful creations could help sniff out one of its most complex and deadly, a new study shows. A team of researchers from the University of Texas in the US and Xi’an Jiaotong University in China has successfully detected and differentiated nerve agent mimics using an imaging device built of humble pieces of Lego.

Geographically and chronologically, little separates colourful plastic bricks from deadly chemicals formulated to asphyxiate. In 1934, in Denmark, a carpenter named Ole Kirk Kristiansen was established a toy workshop, naming it Lego (from leg godt, the Danish for ‘play well’). The company’s initial trade was in wooden ducks and blocks, but by 1958, the trademark binding bricks were patented, soon to take over the world of children’s play.

While Kristiansen was building his business, across the border in Germany a chemist named Gerhard Schrader was setting out to develop cheaper insecticides. Instead, however, he stumbled upon a formula so toxic he was hospitalised for weeks by exposure to trace amounts. An alarmed Schrader passed on his formula to the Wehrmacht, the German armed forces.

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The military brass saw great death-dealing potential in the lethal substance, named ‘tabun’, and set about constructing a plant for its manufacture.

Soon, however, Schrader arrived at a poison deadlier still, an agent that would come to be known as sarin. Schrader’s discovery was never deployed in World War II, but has since been used to devastating effect in various attacks in the Middle East, and famously in the 1995 Tokyo Metro attack.

Tabun and sarin were later classified as the first two agents of the G-series of nerve agent, so named for their German origins. The second family is the V-series – the ‘V’ variously stands for ‘venomous’, or ‘viscous’ – and has been developed by, among others, the British, Russian and Chinese. V-series substances are particularly deadly because, unlike the G-series, they do not degrade easily and are difficult to wash away.

Both classes of nerve agent target enzymes that control the nervous system and can cause death in minutes or even seconds. Complicating matters, each requires different decontamination protocols and, as such, differentiating between them is as crucial as detecting their very presence. Failure to do so can have profound consequences, particularly given the ever-present loomng threat of terrorist attacks.

Unfortunately, the latest study, published in the journal ACS Central Science, found “few strategies have been reported for the detection of nerve agents demonstrating high sensitivity and quantitative accuracy, and with the ability to discriminate between the V- and G-agents, as well as an ease of operation that makes the entire analysis field deployable”.

The researchers, led by Texans Edward Marcotte and Eric, thus identified the need for a simple, compact device which can be cheaply assembled from common household items and speedily deployed. To meet this brief, they turned to Lego and a smartphone, constructing a dark-box from the former and using the latter as a camera.

“Admittedly, we could have used a 3D-printer to generate the box,” Marcotte explains, “however, Lego is a far easier medium from which to construct such a device.

“First, one does not need to generate a CAD file each time a new design is needed, and Lego can be reconfigured rapidly and on-the-go to suit the design needs of the user. Lastly, Lego can be disassembled into pieces easily housed in a portable bag.”

With the dark-box constructed, the researchers treated the nerve agent mimics – one, a fluorophosphate mimic of a G-series agent and the other a thiophosphate mimic of a V-series agent – to release fluoride and thiols respectively.

The resulting chemicals were then used to trigger a self-propagating cascade of reactions that amplify an optical signal resulting from a by-product of the decomposition of the agents.

The colour and intensity of emissions from the mixtures change relative to the amount of chemical weapon present, and these changes can be easily captured with simple technology and co-operative lighting.

The samples were then transferred to a standard 96-well test plate and moved into the Lego dark-box, where the changes were illuminated with an ultra-violet lamp, captured with the smartphone camera and analysed with free software.

Besides the blocks and phone, the lamp and test plate are the only other essential components in the system.

In addition to being quick, simple and cheap to use, the new method proved capable of quantifying amounts and distinguishing between different classes of agent present at contaminated sites. To encourage wide adoption of their technology, the researchers uploaded their analytic code, image guides, and a demonstration video to the source code hosting service, GitHub.

Further study, however, will be required to address the growing threat of third class of nerve agent. Known as the N-series, it comprises the agents dubbed in Russian as ‘novichok’ (‘newbie’) that were developed by the Soviet Union in the 1970s. One of these was deployed in the recent assassination attempt on ex-Russian spy Sergei Skripal and his daughter in Salisbury, UK in March 2018.

Original Link

This week in science history: Margarine inventor’s fame spreads

French scientist Hippolyte Mège-Mouriès died on May 31, 1880. And yes, he is recognised as the inventor of margarine, but he was also a resourceful chemist with a range of useful discoveries to his name.

An article published in the Journal of the American Oil Chemists’ Society says Mouriès, who born October 24, 1817, in southern France, had early success improving upon Copahin, a common remedy at the time for syphilis. He refined the drug using nitric acid, which eliminated side effects, and was awarded a prize for this achievement.

Around 1850, he added his mother’s maiden name to his own, and became known as Hippolyte Mège-Mouriès, except in official documents.

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Other early patents granted to him included the invention of effervescent tablets, refinements in paper- and sugar-making, and the use of egg yolks for the tanning of leather.

In the early 1850s he began researching foods. He found that some species of animals have more calcium phosphate in their blood, and from this he developed and marketed a “health food” chocolate with added calcium phosphate and protein.

His next big project was to study bread-making, coming up with a technique that yielded 14% more product from the same amount of raw materials. He lectured on his process in Berlin, Brussels and Paris, and was awarded two gold medals for it. Napoleon III gave him the Legion of Honour.

By 1867, Mouriès had turned to dairy products. France had a butter shortage, and there was also a desire to produce a table fat for the French navy that would not quickly turn rancid.

Napoleon III offered a prize for anyone who could produce a butter substitute. In 1869, Mouriès developed and patented a process for churning beef tallow with milk to create an acceptable alternative, thereby winning the Emperor’s prize.

Mouriès called it oleomargarine – from the Latin oleum, meaning beef fat, and the Greek margarites, meaning pearl, because of the animal fat that formed pearly drops.

In her 1930 book Margarine as a Butter Substitute, Katherine Snodgrass details the Mouriès process, as described in his British patent from 1869.

“A fatty body identical in chemical composition with butter is obtained from fresh suet by crushing it between rollers under a stream of water, further washing it and then digesting it with agricultural gastric juice,” she writes.

“The fat is extracted, melted, passed through a sieve and poured into boxes to set, after which it is cut into pieces, which are wrapped in cloths and pressed between hot plates. A fatty body is expressed and may be agitated in a closed vessel, cooled, cut up, bleached with acid and washed with water.

“This purified fat is mixed at animal heat (104°F) with water containing small quantities of bicarbonate of soda, casein of cold milk and mammary tissues along with yellow colouring matter. This is digested, allowed to settle, decanted and cooled and yields a preserved butter.”

Mouriès eventually died of liver failure. Only his hometown newspaper recorded his passing.

Original Link

A choice of waters: still, sparkling, para or ortho?

We all know water is H2O. Now researchers have discovered if you stick one H from the pair on upside down, it changes how water behaves – a surprising new insight into the chemistry of one of the most important substances on our planet.

Hydrogen atoms have a magnetic orientation, called spin. When two hydrogens form water by attaching to either side of an oxygen atom, like ears on a Mickey Mouse cap, they can end up in one of two configurations: with their two spins opposite ways up, a form called para-water; or with spins symmetrical, called ortho-water.

Although researchers knew all the water on our planet is a mixture of both, they have only recently found a way to separate the two forms because they behave almost identically at room temperature.

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But new experiments reported in the journal Nature Communications show there are differences in the behaviour when the molecules are cooled to freezing. These temperatures are similar to those found in outer space, suggesting the discovery could provide insights into reactions that might form the building blocks of life in interstellar regions.

Stefan Willitsch from the University of Basel in Switzerland used a technique pioneered at Germany’s Hamburg Centre for Free-Electron Laser Science to separate out streams of para- and ortho-water molecules.

Willitsch and his team then shot the results at nitrogen molecules to which hydrogen ions had been added – creating a species known as a diazenylium ion, which occurs in interstellar space.

The team was looking for a reaction that occurs in space, in which a water molecule collides with a diazenylium ion and steals its hydrogen, forming hydronium (H3O+).

The surprise was that the para-water was 25% more likely to make a successful theft than ortho-water.

“That we can really show they have different chemical reactivities is a pretty fundamental insight,” said Willitsch.

“It’s one of the most fundamental molecules on this planet – in the entire universe, so this is quite an important piece in the whole puzzle.”

Willitsch doesn’t believe the finding will have a big impact on most chemistry, however. While water molecules in isolation stay in their ortho or para form, in water’s liquid, room-temperature state, there are constant molecular collisions between molecules that quickly mix the two forms up.

A disappointment perhaps – it seems that for we humans at terrestrial temperatures, there will never be a chance to compare the tastes of pure para-water and ortho-water.

Original Link

The shape of water

While liquids seem to be formless masses that flow without structure, the illustration above shows some of the complex patterning present inside liquid water.

In particular, it reveals how water molecules are arranged in the liquid around a central reference molecule. The H2O molecule is shown with a large central oxygen atom in red flanked by a pair of smaller white hydrogen atoms.

The white areas show the highly directional organisation of water density in the first and second structural ‘shells’ arising from the hydrogen bonds, while the orange areas show the depletion regions where no water molecules can reside.

The image was obtained using the quantum Drude oscillator model, which describes how atoms and molecules can be polarised in the presence of an electric field.

It was created during a detailed modelling exercise of the behaviour of liquid water, which exhibits dramatic and unusual changes to its physical properties with changing temperature, particularly near the freezing point.

Original Link

The chemistry of indulgence

File 20180314 113452 cmk3qq.jpg?ixlib=rb 1.1
It’s not just our taste buds thanking us when we give ourselves a sweet treat. Rakicevic Nenad/Unsplash

Every day we make a range of choices in the pursuit of pleasure: we do things that make us feel good or work in a specific job because it’s rewarding or pays well. These experiences help shape our perspectives on life and define our personality.

Consequently, problems with our ability to manage or maintain our pursuit of pleasure often lie at the root of many neuropsychiatric disorders such as addiction and depression.

What’s going on in the brain when we experience pleasure?

Pleasure itself – that good feeling you get in response to food, sex and drugs – is driven by the release of a range of neurotransmitters (chemical messengers) in many parts of the brain. But dopamine release in the brain’s reward system is particularly important. Dopamine release tells the brain when to expect something rewarding, modulates how rewarding it will be and drives us to seek rewarding things.


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Dopamine is also important for a range of other functions such as voluntary movement and cognition. Disorders such as schizophrenia have too much dopamine release, which causes psychotic symptoms. In neurodegenerative disorders such as Parkinson’s disease, the dopamine cells responsible for motor coordination die prematurely.

All drugs of abuse, no matter their primary mode of action, release dopamine in this system. Other rewarding experiences – sex, food, and gambling – are also associated with increases in dopamine release. Conversely, decreases in dopamine within reward systems are associated with depression, a lack of pleasure or motivation, and withdrawal.

We all experience pleasure differently as a result of individual differences in biology or neurochemistry, but also as a result of past experiences (no longer liking a food that previously made you sick), and differing social and cultural factors.

For example, musical preferences seem to be shaped more by upbringing than by biological factors. So while some may get a greater hit of dopamine from buying a new handbag, others may get it from placing a bet on a sports match.

Poker machines are designed to tap into our reward centres. krissia cruz unsplash

Decisions, decisions, decisions…

When we make decisions, some are habitual and less reliant on pleasure, and some are more goal-directed. Most of us would probably love to eat ice cream for lunch every day because it tastes good, and sugar releases dopamine in reward systems. But we know if we ate ice cream every day we would put on weight, become less healthy and feel worse because of it. This knowledge takes some of the pleasure out of it and makes us less likely to want ice cream all of the time.

The cognitive processes behind goal-directed behaviour involve determining the value of the potential outcomes and forming a strategy that maximises our ability to achieve the most valuable outcome. And if we make the same decision enough times and the outcomes stay the same, our decisions become less goal-directed and more habitual in nature.


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But certain choices do not always lead to a positive outcome. In these cases, over time we learn which outcome provides the best overall reward. We then guide our decisions towards this outcome, even if occasionally it does not result in a positive outcome.

Gambling is a good example of how this process can become problematic. Poker machines provide a positive outcome just often enough to keep you playing, even though they are programmed so that you lose money in the long run.

When decision-making goes wrong

Having issues at any point in the decision-making process can lead to pathological behaviour. Addiction is categorised by a single-minded focus on obtaining the next exposure or “hit” (be it drugs, a pokies win, sex). So much so the individual makes bad decisions in order to attain this particular outcome, even if they no longer find it that pleasurable.

We still know little of how addictive behaviours start and persist, but genetic and environmental factors can put someone at a greater risk. For example, finding a certain drug more pleasurable (due to differing drug metabolism or an increased dopamine response) places a greater value on its use, which can lead to continued consumption. This may become addictive if the behaviour becomes more habitual and less sensitive to bad outcomes and experiences.

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Dopamine release is essential for the rewarding response we feel toward a particular outcome and inflating the “wanting” of that experience. Because this drives continued use, dopamine release in reward systems is important for the development of addictive behaviours.

However, by placing a much greater level of value on the outcome (so it appears the best option in nearly any comparison), and accelerating habit formation (so the negative consequences of this decision are ignored), the brain warps its own decision-making capabilities. At this point, attaining the outcome in question becomes less about dopamine release and more of a subconscious drive. Therefore, statements like “just stop using drugs or doing x” are of little use.

This is why multiple approaches are required to treat addictive behaviours. There is a quest to develop medications that adjust the neurochemical balance to weaken these habitual behaviours. Inevitably, these will require other interventions such as cognitive behavioural therapy and social support networks to help retrain the brain and improve decision-making capabilities.

James Kesby, Advance Queensland Research Fellow, The University of Queensland

This article was originally published on The Conversation and republished here with permission. Read the original article.

Original Link

This week in science history: The man who melded science and photography is born

In science, one person’s discovery can open the door to a rush of advancements, supplemental developments and ancillary activities. Such was the case when word came out of France about the discoveries of Louis Daguerre and the fledgling science of photography.

In his article Into the Light: John William Draper and the Earliest American Photographic Portraits, historian Howard R. McManus writes of the many people in the early nineteenth century who were experimenting with light and chemistry in an effort to capture photographic images, and how they were galvanised when details of French artist Daguerre’s processes were made public. Among them were such luminaries as Samuel Morse, Henry Fox Talbot, and John William Draper.

Draper, born in Lancashire, England, on May 5, 1811, has been credited with producing the first clear photograph of a female face, in about 1839, and the first detailed photograph of the moon, in 1840.

Draper’s work in photography was an outgrowth of his research in photochemistry, and McManus writes that he “made portrait photography possible by his improvements on Daguerre’s process”, which was the first practical method of making permanent images with a camera. The daguerreotype process produced direct positive images on a silver-coated copper plate.

McManus says Draper was among the first practitioners of photography to immediately use his scientific knowledge of the important difference between the visual and chemical focus. He understood that light rays towards the violet end of the spectrum had the most intense photographic effect. This allowed him to speed up the process and build more effective lenses.

One of Draper's photographs, capturing the solar spectrum.

One of Draper’s photographs, capturing the solar spectrum.

SSPL/Getty Images

He immigrated to the US in 1832 and wrote several books on a range of topics, including the successful 1874 work History of the Conflict between Religion and Science, in which he proposed the theory of intrinsic hostility in the relationship between the two fields.

As a chemist, Draper in 1841 came up with what is known as the Grotthuss–Draper law (also called the principle of photochemical activation), which states that only light that is absorbed by a system can bring about a photochemical change.

In 1843 Draper constructed a “tithonometer”, a device for measuring the intensity of light, based on an earlier discovery that light causes hydrogen and chlorine to combine progressively.

In 1847 he proved that all solid substances become incandescent at the same temperature, that thereafter with rising temperature they emit rays with increasing sensitivities to refraction, a quality known as refrangibility, and (a fundamental proposition of astrophysics) that incandescent solids produce a continuous spectrum.

For his researches on radiant energy, Draper received the Rumford Medal of the American Academy of Arts and Sciences in 1875. He died on January 4, 1882.

Original Link

This week in science history: The dark lady of DNA dies

The Nobel Committee does not make posthumous prize nominations, but if it did, British chemist and researcher Rosalind Franklin, who died on April 16, 1958, is widely regarded as a deserving recipient.

Franklin’s work on X-ray diffraction images of deoxyribonucleic acid (DNA) contributed to the discovery of the DNA double helix, for which James Watson, Francis Crick and Maurice Wilkins shared the Nobel in Physiology or Medicine in 1962.

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Watson later suggested Franklin deserved a Nobel for chemistry, along with Wilkins, if it were not for the prohibition on posthumous nominations.

Noberprize.org says of the double-helix discovery: “The sentence ‘This structure has novel features which are of considerable biological interest’ may be one of science’s most famous understatements. It appeared in April 1953 in the scientific paper where James Watson and Francis Crick presented the structure of the DNA-helix.”

The organisation says the discovery “solved one of the most important of all biological riddles”.

Franklin’s biographer, Brenda Maddox, called her “the Dark Lady of DNA”, based on a disparaging reference to Franklin by one of her coworkers, and also because although her work on DNA was crucial to the discovery of its structure, her contribution to that discovery is little known.

Franklin studied physics and chemistry at Newnham Women’s College at Cambridge University in the UK, and then went to work for the British Coal Utilisation Research Association, where she studied carbon and graphite microstructures, forming the basis of her doctorate in physical chemistry, which she earned from Cambridge in 1945.

Her studies took her into the field of X-ray crystallography, which would become her life’s work.

Rosalind Franklin's famous "photograph 51", revealing the double helix structure of DNA.

Rosalind Franklin’s famous “photograph 51”, revealing the double helix structure of DNA.

R. Franklin

X-ray crystallography uses X-rays to determine the precise arrangements of atoms in a crystal. The beams strike a crystal – and some biological molecules, such as DNA, can form crystals if treated in certain ways – and diffract in specific directions, revealing the arrangement of atoms, generating information that can be used in a range of studies.

Nobelprize.org says it was Franklin’s crystallographic “photograph 51” that revealed the helical structure of DNA to Watson and Crick in 1953. This picture of DNA that had been crystallised under moist conditions shows a fuzzy “X” in the middle of the molecule, a pattern indicating a helical structure.

Franklin moved on to make important discoveries about ribonucleic acid (RNA) and virus particles, including the tobacco mosaic virus and polio. Her work was cut short, however, when she died of ovarian cancer at age 37.

Original Link

Scientists build custom molecules with optical tweezers

In a first-of-a-kind chemical reaction, US researchers have combined individual atoms to form a molecule that may be used in quantum computing. Phil Dooley reports. Original Link

Forgotten women in science: Tapputi-Belatekallim

The history of women in science doesn’t just go back to tales of female scientists and philosophers such as Hypatia of Alexandria; it also extends some 6,000 years back to ancient empires in Mesopotamia, the cradle of civilisation.

Many of these women’s names have since been lost in time and all that remains of them are depictions of their likenesses in stone carvings. But one of the first women whose name we do know belongs to that of a Babylonian chemist: Tapputi-Belatekallim (c.1200 BCE).

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Archaeologists found a record of her work in clay cuneiform texts dating back to 1200 BCE. In ancient Babylon, perfumes were not just cosmetic scents for beauty purposes: they were fragranced substances that were required for medicinal purposes and religious rituals alike.

As a royal perfume-maker, Tapputi wasn’t just the head of her own household (which is what “Belatekallim” means); she is spoken of as being an authority in her field and the official overseer of perfumery in the royal palace.

As any modern-day perfumer will tell you, the creation of perfumes – even for cosmetic reasons alone – doesn’t just entail mixing up scents to see what smells nicest. It requires an intimate knowledge of chemistry and an understanding of technical processes such as extraction and sublimation. Tapputi wielded these skills well over a millennia ago.

We know little of Tapputi’s background or personal life, but history has left us with one of her recipes: a fragrant salve for the Babylonian king. In this fascinating relic, Tapputi takes the reader through the step-by-step routine necessary to produce a royal ointment containing water, flowers, oil and calamus, which may either refer to lemongrass or a reedlike plant that is still used in perfumes today.

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She describes the process of refining the ingredients in her ‘still’: a chemical apparatus for distilling and filtering liquids. Advanced versions of such equipment remain in use in labs today, but Tapputi’s reference to a still is the oldest in human history. That makes her one of the earliest chemical engineers that we know of.

Tapputi is not the only woman mentioned in the cuneiform tablets about perfumery. Another female chemist is noted in these records, though the first half of her name has been lost. We only know her as “[–]ninu”, though she is described as the author of a text on perfume manufacturing.

It’s not surprising that women were so intimately involved with chemistry. The list of equipment used seems to be co-opted straight from a Babylonian kitchen or adapted and modified from everyday utensils and cookware. This appears to suggest that women were chemistry’s earliest adopters and innovators, and that there is a lot less separating the art of cuisine from the science of chemistry than many people may think.


This is an extract from Forgotten Women: The Scientists by Zing Tsjeng. Published by Hachette Australia, RRP $27.99.

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Chemtrails? Hardly. The science behind aeroplane contrails

Everyone has seen the cloudy white trails across the sky that sometimes follow jet aircraft. It’s easy to imagine that they are sign of chemicals raining down from above. Among certain conspiracy-minded folks they have been dubbed ‘chemtrails’ and are believed to be evidence of secret government projects with various nefarious purposes, most often involving weather modification or climate engineering.

What’s the real reason? These condensation trails, or contrails, are simply what happens when the chemistry of burning jet fuel meets the chemistry of air. The video above from the American Chemical Society sets the record straight.

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In science today: Remembering a man who used his noodle

Monday March 5 marks the one-hundred-and-eighth years since the birth of one of the most successful technologists of the twentieth century – a man who transformed much of modern life, yet remains virtually unknown outside his home country of Japan.

His name was Momofuku Ando and he was the inventor of instant noodles.

That may sound trite, but it’s not. Ando came up with a way to preserve and extend the life of a centrally important foodstuff and in doing so completely revolutionised food production, food storage, food retailing, and diet.

According to the World Instant Noodle Association (yes, there is such a thing) in 2016 there were 97.4 billion servings of Ando’s invention sold in more than 54 countries.

While China consumes 44% of the global instant noodle total, South Koreans show the most dedication to the dish, eating on average 69 packets a year. According to a survey taken in 2000 by the Fuji Research Institute, the Japanese consider instant noodles their nation’s best invention ever – better than robots, karaoke, Hondas, personal stereos and Pokemon.

Do you want to know what’s better than sliced bread? Instant noodles, by a very long chalk.

Ando himself was born in Taiwan, but took Japanese citizenship after World War II.

He invented instant noodles – more specifically, an efficient way of flash-frying freshly made, highly elastic, noodles in order to reduce their moisture content to around 2%, dramatically extending their shelf life – by experimenting in a wooden shack in his backyard in Ikeda-Shi, Osaka.

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In 1958, once he had perfected the process, he formed a company called Nissin Food Products and put his invention on sale, calling it Chikin Ramen. In 1971, he further refined his processes and introduced the world’s first cup noodles, which he called, imaginatively enough, Cup Noodles.

While his invention has become a staple food worldwide, Ando himself is little remembered outside Osaka – where he is regarded as a hero. He is the eponymous subject of the Momofuku Ando Instant Ramen Museum, a large and extremely popular attraction in the Osaka suburb of Ikeda, not far from where his shack used to stand.

Ando died in 2007, but not before extending the application of technology to noodles one more time. In 2005, he invented “Space Ram”, the first instant noodles specifically designed to be prepared and eaten in micro-gravity.

That same year, Japanese astronaut Soichi Noguchi carried a packet onboard the space shuttle Discovery.

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Video: How to make your cocoa divine

Every night around the world, especially in the colder bits of it, millions of people relax with a nice mug of hot cocoa.

The problem, though, is not everyone can afford to buy high-end powdered beverages. Many, therefore, have to make do with budget brands that, all too often, produce a drink that is watery, lumpy, and just plain yuck.

Thankfully, however, it doesn’t have to be this way. The good folk at the American Chemical Society – who, like most scientists, like a nice hot drink and don’t have much money – have worked out a number of kitchen hacks to render even the most miserable cut-price cocoa rich and delicious.

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Edible electronics are on the way

Graphene patterns can be written onto everyday materials such as food, paper, cloth and cardboard, say US scientists, potentially producing a new class of edible electronics.

Graphene is a revolutionary material made up of a single layer of carbon atoms arranged in a honeycomb lattice. It is almost completely transparent, extremely light and strong, and an efficient conductor of heat and electricity. Ongoing research is working to exploit its properties in diverse applications such as tissue engineering, water filtration, solar cells and glass-based electronics.

As described in a study published in the American Chemical Society journal ACS Nano, a team of scientists led by Yieu Chyan and Ruquan Ye of Rice University in Texas, US, used a commercial laser to create graphene patterns on a variety of materials, including paper, cardboard, cloth, coal, potatoes, coconuts, and toast.

“This is not ink,” says James Tour, Rice University chemist and co-author of the study. “This is taking the material itself and converting it into graphene.”

The materials used in the study have a common factor: lignin, a complex organic polymer that binds the cells, fibres and vessels of many plants and algae. Crucially, it is largely composed of carbon.

The team claim that any material with a high enough carbon content can be turned into graphene. In 2011 they made graphene out of insects, waste and even Girl Scout cookies, using a different technique involving carbon deposition on copper foil.

The team recently developed the new technique of laser-induced graphene (LIG), which uses a computer-controlled laser to transform a variety of materials into porous graphene foam. Instead of a conventional lattice, the foam consists of a jumble of microscopic, cross-linked graphene flakes about 20 microns thick.

To create the foam, a laser is passed over the target surface multiple times, first converting the lignin-rich surface into amorphous carbon and then into graphene. Defocusing the laser makes the beam of light wider, allowing for more speed and finer control.

Using this technique, the team made an LIG micro super-capacitor in the shape of an “R” (for Rice University) on a coconut, and etched a graphene owl on cloth.

This is a step up from the previous state-of-the-art method of making patterned graphene, which involved transferring a sheet of it onto the desired surface and then etching away the excess.

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Tour is enthusiastic about the potential applications. “Perhaps all food will have a tiny RFID tag that gives you information about where it’s been, how long it’s been stored, its country and city of origin and the path it took to get to your table,” he says.

LIG tags could also be used as sensors with the ability to detect E. coli or other microorganisms in food. “They could light up and give you a signal that you don’t want to eat this,” says Tour.

Shaun Hendy, a physicist at the University of Auckland who was not involved in the study, comments: “Modern electronics relies on materials that are not sourced sustainably, so this technique could help put the industry on a more environmentally-friendly footing.”

The technique may also have applications in biodegradable, edible and wearable electronics. But it is not quite ready for widespread use yet.

“The graphene produced still has many defects and is unlikely to have the properties required for transistors,” says Cameron Shearer, nanoscience researcher at the University of Adelaide who was also not in the research team. “A method to make perfect graphene, with a metal catalyst and in a patterned form, is a research goal in this area.”

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Making skis strong enough for Olympians to race on

Olympians expect top-notch performance from their minds and bodies, but they get crucial advantages from the very best equipment for their sports and the weather conditions they’re competing in. Skis, for example, must stand up to near-constant changes in stress during races.

The ideal ski provides a stiff and rigid platform for skiers’ boots to attach to, flexes to carve through turns, doesn’t break under the pressure of jumps and landings and is light enough not to slow the athlete down. But that’s not all: Skis must resist damage from collisions, absorb vibrations from icy conditions and withstand the temperature extremes and intense sunlight common in mountain environments.

That’s a lot to ask of a single item. The first skis were made of strong, flexible ash wood, but technology has found ways to do much better. Today’s materials design and construction processes are closely guarded industrial secrets, specific to individual ski companies. But I and other materials experts know that the essential components and methods are very similar: All skis are like sandwiches, stacking separate layers of different materials with all those separate properties into a single item, a competition-class ski.

Ski technicians and technology help athletes do their best.

Advanced materials for extreme conditions

Ultra-high molecular weight polyethylene is a highly engineered plastic often used in high-strength ropes as well as in artificial hip and knee implants. It’s tough, bends and flexes a lot without breaking, resists scratches, retains its properties across a range of temperatures and has tiny microscopic pores across its surface. When it’s used as the base layer of a ski, those microscopic pores act like a sponge into which racing wax is melted to fine-tune the ski’s contact with whatever the snow conditions are.

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The sides of the ski base are made of high-strength steel alloys that are heated and processed to meet the demanding conditions of skiing. These processes make the steel resistant to rust and able to be sharpened like a knife. The steel needs to hold its edge to carve through snow and ice while flexing with the rest of the ski without cracking or breaking.

Inside the ski

On top of the base is a complex layer in the ski sandwich, an element itself called a “sandwich panel,” made of similar materials and with the same techniques as those used to build spacecraft, aircraft and performance race cars. The center of the sandwich is a core material surrounded by fiber-reinforced composites.

The cores of ski sandwich panels can be lightweight titanium alloys, polymer foams similar to Styrofoam coffee cups or different kinds of woods – such as maple, oak, aspen or poplar. These different plastic, wood and metal materials are layered and combined to tune the ski to the desired levels of strength, stiffness, ability to twist and vibration-damping, all with as little weight as possible.

The outer layers of the sandwich panel are made from epoxy resins – high-performance glues – into and onto which are laid engineered fabrics like carbon fibers, fiberglass and Kevlar. These resin-fiber layers hold the sandwich core structure together and make all of the different material types work as one.

Like the core, these composite layers vary in thickness and makeup along the ski. They’re even applied at different angles to the ski itself to improve ski stiffness and strength.

The sandwich panel ski makes turning quicker and helps the ski ride smoothly over bumps and ruts in the terrain. It’s more responsive to the skier and more stable at high speeds than less advanced designs because it can take advantage of the best aspects of all its ingredients. Overall, the sandwich panel is built to be stiffest under the binding area where the boot attaches, and more flexible near the ski tips, to glide more easily over uneven terrain. Each ski’s sandwich panel is designed and built to optimize performance in a specific skiing event – such as downhill racing, snowcross or jumping – or even a particular skier’s preferences.

Rapid improvement

The ski industry, and particularly its competitive elements, are willing to take risks and push limits, exploring the most advanced materials concepts to achieve optimum performance. As a result, decades of research have improved Olympic skiers’ times significantly over the years.

That work has also spread benefits well beyond the Olympic medal podium and into the recreational market. Amateur skiers can explore more advanced terrain and more challenging slopes with help from the tuned spring response, vibration damping and light weight of their skis. Recreational skiers can also go faster in changing snow conditions and steer more easily through turns because their skis are adaptable and responsive to individual skiers’ strengths, as well as slope conditions. The materials advancements help recreational skiers ski well on terrain previously accessible only by superior athletes.

All these advances happen very quickly. Before the next Winter Olympic Games, consumers will likely be able to easily purchase the same kinds of skis and snowboards that the 2018 Olympians competed on – and the 2022 Olympians will be using even better materials that help them go faster, higher and stronger than ever before.

This article was originally published on The Conversation. Read the original article.

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The many ways your house is killing you

We may not think of our living rooms and offices as chemical factories, but reactions occurring within them can produce a dangerous array of toxic air pollutants, scientists say.

In some cases, these chemicals are formed by the same reactions that produce urban smog, says Sasho Gligorovski, a physicist and atmospheric chemist at the Chinese Academy of Sciences in Guangzhou, China, and coauthor of a review article on the subject in the journal Science.

For example, he says, indoor environments can contain highly reactive hydroxyl (OH) radicals at levels comparable to those in outdoor air. That’s a surprise because in urban smog, hydroxyl radicals are produced by photochemical reactions involving ultraviolet radiation from the sun and nitrogen-containing pollutants from such sources as car exhaust. Finding similar levels of hydroxyls in indoor air, he says, means that enough ultraviolet is penetrating windows to produce the same reactions indoors.

And while this doesn’t mean indoor air is turning into smog, it does mean that a lot of chemical reactions are possible within it.

“The high concentration of OH radicals indoors makes the indoor environment [into] a reaction chamber,” Gligorovski says.

In addition, while we may think of our air-conditioned indoor air as cleared of pollutants, we are constantly adding materials into it, ranging from household cleaners to hairspray, cooking fumes, and scented candles. Some, like cigarette smoke, have long been known to be toxic. Others might be surprising. For example, Gligorovski says, burning incense is associated with increased risk of lung, throat, and mouth cancer, especially among people who are frequently exposed to it, as in Buddhist temples.

Even our own bodies can be sources of such chemicals. A paper in the journal Proceedings of the National Academy of Sciences, Gligorovski says, found that oils on our skins will react with ozone in indoor air, producing a host of potentially dangerous byproducts.

“The chemistry is sufficiently fast that many of the chemically reactive oils on our skin are transformed into more oxidised molecules on timescales of tens of minutes,” he says.

Other scientists note that such reactions aren’t the only processes at work in indoor air — and may not be the most dangerous ones. It’s long been known that in some geological settings, buildings can collect enough radioactive radon gas seeping up from the ground to significantly increase the risk of lung cancer.

Also, dampness and mould are clearly associated with respiratory health effects, such as asthma, says William Fisk, a mechanical engineer who heads up the Indoor Environment Group at Lawrence Berkeley National Laboratory, Berkeley, California.

“Indoor allergens from dust mites, cockroaches, rodents, and pets [also] contribute to allergy and asthma symptoms,” he says.

How the new findings about indoor air chemistry fit into this context isn’t yet known, but “clearly, there are many chemical reactions occurring indoors,” Fisk says. “The significance of these for human health is not well understood and should be investigated.”

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Hugo Destaillats, an environmental chemist in the same research group as Fisk, adds that chemical reactions of the type discussed by Gligorovski don’t occur only in the air. They also occur on surfaces — important because indoor environments have a much higher surface to volume ratio than the great outdoors.

Not to mention that many of our indoor materials have complex three-dimensional structures through which air can percolate.

“Think about the thick layer of gypsum compressed in the wallboard commonly used in the USA,” he says. “Or about the fibres in carpet, or the polyurethane foam in upholstery and bedding.”

Not only do these materials have large surface areas exposed to the air, but they may accumulate pollutants today, only to release them in the future.

Meanwhile, Gligorovski says, it’s important to learn more about indoor air chemistry. Partly that’s because we spend a lot of time indoors, but it’s also because energy-efficient homes and offices have reduced ventilation, increasing the degree to which indoor air pollutants can build up.

“Considering that people spend on average 80 to 90% of their life indoors, indoor air quality is of major importance,” Gligorovski says.

But that doesn’t mean the situation is hopeless. “Understanding indoor chemistry can help us design materials that effectively sequester and eliminate pollutants from indoor air,” Destaillats says. “There are already some products on the market with these advanced functionalities. I anticipate that we will see more in the near future as we learn more about how to control indoor chemistry to our benefit.”

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Soon, skyscrapers could be made of wood

Wood has been employed as a building material for thousands of years, but in today’s world of office towers and massive industrial complexes its usefulness is distinctly limited. Now, however, US scientists have demonstrated a treatment method that could see it being used instead of steel girders in major building projects.

Abundant and cheap, wood has long been a favoured choice as framework for houses. Beyond a certain size, however, it breaks or warps under pressure, limiting its use. It is also porous, and can expand and therefore weaken in humid conditions.

On the plus side, wood is a renewable resource that costs comparatively little and requires much less energy input than stronger materials – such as steel and alloys – routinely used in the making of big structures.

Recognising this, scientists and engineers have explored several avenues for strengthening wood. These include treating it with steam, heat, ammonia or mechanical processes such as putting under pressure through a roller.

All these methods, however, fall short of producing a sturdy construction material. Compressing it, for instance, reported a team led by Swedish architectural engineer Kristiina Laine in 2016, increased surface hardness but also left it prone to deformation.

The US team, led by Jianwei Song from the University of Maryland and reporting in the journal Nature, has created a two-step process that produces dense wood with “a specific strength higher than that of most structural metals and alloys”, making it a lightweight and low-cost alternative for building projects.

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The first part of the process involves boiling it in a mixture of sodium hydroxide (NaOH) and sodium sulphite (Na2SO3) in order to partially remove two substances that play important structural roles in the formation of plant cells: lignin and hemicellulose.

After this, the wood is put through a hot-rolling process, which causes what’s left of the cell walls to collapse. The result, the scientists say, is a very dense form, characterised by tightly aligned cellulose nanofibres.

The process works with any species of tree.

As well as uses in the building industry, the scientists flag another potential application for their super-dense material – in the military.

Layered sheets of the material, they report, show promise “for low-cost armour and ballistic energy absorption”.

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Some species of bacteria produce methane

Nitrogen-fixing bacteria contain a previously unrecognised pathway for producing methane, researchers have discovered. The ability appears to be a by-product of an enzyme reaction that brings about another gas transformation.

Nitrogen-fixing bacteria are critically important for life on Earth, because they convert atmospheric nitrogen into a form that can be exploited by plants and animals.

However, microbiologists Caroline Harwood and Yanning Zheng of the University of Washington School of Medicine, and published in the journal Nature Microbiology, have uncovered other, more complex chemical feats performed by some of the microbes.

About 10% of nitrogen-fixing species manufacture an enzyme called “iron-only nitrogenase”. The primary function of the enzyme is to convert nitrogen gas into ammonia. Harwood and Zheng, however, discovered that the same enzyme also converts carbon dioxide into methane.

Although iron-only nitrogenase was identified in the mid-Twentieth Century, until now its methane-producing capacity had gone unnoticed.

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“It’s been a neglected enzyme,” Zheng says.

Microbes, primarily archaea, are responsible for producing and consuming around a billion tonnes of methane at all. However, nitrogen-fixing bacteria have until now not been seen as involved in the cycle.

“Methane is potent greenhouse gas,” says Harwood. “That is why it is important to account for all of its sources.”

The scientists made their discovery while working with a bacterial species known as Rhodopseudomonas palustris.

To make sure it was not a property unique to the species, they then tested three other nitrogen-fixing varieties and found the same result. They then checked DNA data and found the genes that produce iron-only nitrogenase in several – indicating that they too are unacknowledged sources of methane.

“There is now recent evidence that iron-only nitrogenase is active in microbes more often and in more conditions than we had previously thought,” Zheng says.

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Young artists show it’s all a matter of chemistry

While the latest issue of Cosmos magazine features the works and words of some of the world’s best science-inspired artists, we’re also inspired by the educational possibilities of the intersection of science and art. At one high school in the Australian city of Melbourne a unit called “Chemists as Artists” has students produce a piece of art representing their personal experience of science.

In doing so students at Mac.Robertson Girls’ High School are expected to both understand chemical concepts and to view the world through a ‘chemistry lens’. “Chemistry is not something that occurs only in a laboratory,” says program coordinator Fiona Donohue. “We wanted our students to develop the skills to think creatively about our world and our place in it and be able to engage others with that way of thinking by expressing their ideas about science through art.

The above featured artwork – The Leaf, ceramic, by Year 9 student Ji Soo Lee – is a fine demonstration of what can result: “Many different chemical processes were required into making this art piece, including oxidation and bisque firing clay,” Lee explains. “Oxidation was needed to turn chromite into chromium(III) oxide, a green pigment used for making paint. Polar molecules were a part of this piece as water is a polar molecule and the pigment needed to be dissolved in it. Because polar molecules only mix with other polar molecules and ionic compounds, the ionic compound chromium (III) oxide was able to dissolve in it. Bisque firing, meanwhile, must allow for a slow build-up of heat, which is why it may take days to complete.”

Here are a few other outcomes from the class of 2017, explained in the words of their creators.

The Robin.

The Robin.

Sara Ahmad, Mac.Robertson High Girls School

The Robin, watercolour, by Sara Ahmad

It is quite amazing when you dive deeper into the chemistry behind watercolour painting.The water and the paint react together, mingling with weak bonds. Water is a polar substance, meaning it has both a partial positive and a partial negative charge. Water colour paint is also polar, therefore it interacts with water. Oil-based paint does not react with water because it is not polar.

Juxtaposition.

Juxtaposition.

Julia Mari Licup, Mac.Robertson High Girls School

Juxtaposition, papier-mâché by Julia Mari Licup

This papier-mâché balloon with oceanic motifs (including sea creatures) was created to show contrast and harmony in both piece and theme. The two subjects in the theme and the contrasting figures in the piece is reflected in the name Juxtaposition. I came across the idea of papier-mâché as I researched sculptures, the technique piquing my interest since it was both affordable and interesting to make. The hot-air balloon, to me, was not only an end agenda but also an exploration of both techniques and self, making the quite simple mesh of art and chemistry something to personally treasure.

The Rose.

The Rose.

Manveen Kaur, Mac.Robertson High Girls School

The Rose, watercolour, by Manveen Kaur

Watercolours aren’t just simple paint; they are a pigment mixture dispersed in a vehicle consisting of six ingredients. The compound glycerine, used to inhibit the hardening of the paint, is ‘hygroscopic’ – able to absorb moisture – due to the three hydroxyl groups in its structure. Water, the ‘universal solvent’, dissolves the chemical components by forming hydration shells around them, once they dissociate into ions. The ‘fisheye’ effect on the leaves can be attributed to ethanol’s high electronegativity and ability to dissolve polar/non-polar substances. The alcohol acts like a magnet for the paint by withdrawing it from the influence of water and, due to capillary action, the paint and alcohol travel in an outward direction faster than water.

The Tile Triptych.

The Tile Triptych.

Chenxin Tu AND Areeba Masood, Mac.Robertson High Girls School

The Tile Triptych, ceramic, by Chenxin Tu and Areeba Masood

Freedom and space for creativity in a seemingly rigid and structured environment is represented by the sturdy foundation of tile covered in two-chemical colour experiments left to flow and spread with minimal control. Incomplete combustion was used to make the cloudy shades of grey on the centre tile, then locked in with a clear nail-polish topcoat. The three images on the tile demonstrate different densities of oil and water, and the action of food colouring, which is generally a polar solvent that dissolves in water but not in oil. The riot of colours on the two side tiles were from tie-dye effects created with permanent markers and concentrated isopropyl alcohol. Miscibility was used to ‘salt-out’ isopropyl alcohol from store-bought rubbing alcohol solution. The concentrated alcohol was then sprayed onto a tile coloured with permanent markers. The isopropyl alcohol is able to dissolve the non-polar ink solvents in permanent markers, leaving behind pigments. The dissolving inks mix at different rates due to the different polarities in differently-coloured dyes.

The Hand You’re Dealt.

The Hand You’re Dealt.

Mandy Ho, Mac.Robertson High Girls School

The Hand You’re Dealt, mixed media, by Mandy Ho

My art piece incorporates the processes of copper etching, marbling paper and crystallising Epsom salt. Throughout the ‘Chemistry as Artists’ unit I learned to view creativity and scientific endeavour in much the same way — a way to express the observed, and to communicate this succinctly yet viscerally. This piece focuses on how science constantly affects me and my way of thinking, from my hands and how I learn my environment, to my blood and how I am connected to the world, to the etched symbols.

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Is this the solution to a major origin-of-life mystery?

Understanding the origin of life on earth is a daunting prospect. Piecing together events which took place around 3.8 billion years ago is extremely challenging, when scientists have to work backwards from complex and highly evolved modern life forms.

A new study by a group from the Scripps Research Institute in California may have provided a key piece to the puzzle, proposing a new chemical cycle which may have been at the core of early life.

All aerobic life-forms generate energy from stored sugars, fats or proteins via a chemical process called the citric acid (or TCA) cycle. This metabolic pathway takes two-carbon molecules (in the form of acetyl-CoA) and oxidises them to form two molecules of carbon dioxide. The energy released from this chemical process is harnessed to produce ATP, the energy source that is used to power cellular processes.

What puzzles scientists is that the citric acid cycle is highly complex, requiring at least 10 different enzymes to function. How could these enzymes have evolved, if a functioning citric acid cycle is fundamental to life? It’s the ultimate chicken-and-egg argument that has stumped scientists for years.

The eminent chemist and origin of life expert Leslie Orgel once said, “If complex cycles analogous to metabolic cycles could have operated on the primitive Earth before the appearance of enzymes or other informational polymers, many of the obstacles to the construction of a plausible scenario for the origin of life would disappear.”

Attempts to demonstrate a simplified citric acid cycle, which might have operated using the simple molecules available on prebiotic earth have been largely unsuccessful.

Now, the team at Scripps, led by Ramanarayanan Krishnamurthy, has identified a chemical pathway which performs a similar function to the citric acid cycle, but uses only simple molecules known to have been available on early earth.

The research is reported in the journal Nature Communications.

The team has linked together two chemical cycles, called the HKG cycle and the malonate cycle, which are able to take a simple two-carbon molecule (in the form of glyoxylate) and convert it into two molecules of CO2.

In the presence of ammonia, this process was also shown to produce aspartate, a simple amino acid which serves as a building block for proteins.

The authors propose that a metabolic process based on the HKG and malonate cycles may have served as an early template for what has now become the citric acid cycle. They also demonstrated that the chemical reactions proceed faster in the presence of iron sulfate, which fits with the theory that iron clusters served enzyme-like roles in early metabolism.

“The chemistry could have stayed the same over time, it was just the nature of the molecules that changed,” says Krishnamurthy. “The molecules evolved to be more complicated over time based on what biology needed.”

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Carbon dioxide fuel plan vanishes into thin air

Oops, that was awkward. A research paper describing the extraction of fuel-friendly hydrocarbons from atmospheric carbon dioxide has been retracted by its authors after they discovered that their method in fact didn’t work.

The 2016 paper, published in the journal PNAS, initially excited attention because it demonstrated a proof-of-concept wherein traces of commercially useful hydrocarbons were recovered from carbon dioxide after the gas was exposed to a titanium dioxide catalyst in a process known as “reverse combustion”.

Scaled up, the method, wrote lead author Frederick McDonnell from the University of Texas and his team, might “solve the world’s energy problems”.

Yet, as academic transparency site RetractionWatch reports, it was the business of scaling up, during additional research in 2017, that hipped McDonnell and his colleagues to the fact that something, somewhere, had gone very wrong.

Running the experiment using bigger quantities of everything resulted only in the same tiny quantity of hydrocarbons. Curious – and by this time worried – the team ran two additional experiments.

First, they repeated the process using lab-generated “pure” carbon dioxide that contained only carbon isotopes. It produced bupkiss.

Then they ran the job again, but this time using helium gas without any carbon dioxide at all. This – impossibly, it would seem – yielded traces of hydrocarbons.

It was at this point that the researchers concluded, sadly, and perhaps accompanied by the sound of hands slapping foreheads, that the hydrocarbons were the result of impurities contained within the titanium oxide catalyst.

Their proof-of-concept, initially so exciting, turned out to be proof of nothing at all.

McDonnell and his team – being diligent and responsible scientists – contacted the PNAS editors and requested the paper be formally withdrawn. Their wish was granted in January 2018.

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Major journal sounds alarm over global mass poisoning

Almost every human being is now contaminated in a worldwide flood of industrial chemicals and pollutants – most of which have never been tested for safety – a leading scientific journal has warned.

Regulation and legal protection for today’s citizens from chemical poisons can no longer assure our health and safety, according to a hard-hitting report in the journal PLOS Biology, titled “Challenges in Environmental Health: Closing the Gap between Evidence and Regulations”.

The report describes a chemical oversight system corrupted from its outset in the 1970s when 60,000 chemicals were registered for use in the US, mostly without being safety tested. Many of these chemicals were subsequently adopted as ‘safe’ around the world.

Over the years, public health protection has stagnated – despite mounting scientific evidence that many chemicals are damaging whole classes of organisms, say report editors Liza Gross and Linda Birnbaum.

“We still have safety data on just a fraction of the 85,000-plus chemicals now approved for use in commerce. We know from field, wildlife, and epidemiology studies that exposures to environmental chemicals are ubiquitous,” the researchers say. (European estimates put the number of proposed new chemicals worldwide at over 145,000.)

“Hazardous chemicals enter the environment from the factories where they’re made and added to a dizzying array of consumer products – including mattresses, computers, cookware, and plastic baby cups to name a few – and from landfills overflowing with our cast-offs,” Gross and Birnbaum say.

“They drift into homes from nearby agricultural fields and taint our drinking water and food. Today, hundreds of industrial chemicals contaminate the blood and urine of nearly every person tested, in the US and beyond.

“Evidence has emerged that chemicals in widespread use can cause cancer and other chronic diseases, damage reproductive systems, and harm developing brains at low levels of exposure once believed to be harmless. Such exposures pose unique risks to children at critical windows of development – risks that existing regulations fail to consider.”

The report underlines a recent finding by The Lancet Commission on Pollution and Health which concluded nine million deaths (or 16% of the total) every year worldwide are due to diseases caused by the human chemical environment – 15 times the number killed in wars.

The PLOS report explores eight dimensions of the emerging chemical crisis. Key points include:

  • “Countless chemicals were entered into commercial use without toxicological information. Few chemicals of the many identified as potential public health threats were regulated or banned,” Sheldon Krimsky of Tufts University states in a strong critique of policy failures.
  • Contrary to what some chemists claim, many substances become more poisonous at low doses than at high ones. For some toxins there is no safe dose level and “we will need to achieve near-zero exposures to protect public health,” says Bruce Lanphear of Canada’s Simon Fraser University.
  • Children face the highest risks from chemical poisons, while scientists are still working are working to determine the full range of chemicals we carry in our bodies and their effects on our health, say Joseph Braun and Kimberley Grey.
  • Several articles document the failure of government to keep hazardous chemicals from polluting our food, air, and drinking water. Maricel Maffini and colleagues describe the failure of regulators to account for health risks associated with the thousands of chemicals introduced into the food system by the US Congress and other governments since 1958.

The PLOS report concludes there is a need for more research and a much tougher approach to regulation – but these will not be enough. Citizens themselves will have to force governments to take stronger action to protect human health, it finds.

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