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  • richardmitnick 11:06 am on May 17, 2019 Permalink | Reply
    Tags: , , Chemistry, Cholesterol is an essential component of the membranes that enclose all of our cells., Squalene monooxygenase has a “destruction code” that acts to bind ubiquitin when unlocked initiating its own destruction., Squalene monooxygenase has also been linked to high cholesterol in human cancers including liver; breast; and prostate cancers., , Why biology has introduced such an unusual chemical modification is still not well-understood.   

    From University of New South Wales: “Scientists find ‘molecular destruction code’ for enzyme involved in cholesterol production” 

    U NSW bloc

    From University of New South Wales

    17 May 2019
    Isabelle Dubach

    A newly identified mechanism that regulates a particular enzyme could lead to the development of new, cholesterol-lowering drugs.

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    UNSW PhD Candidate Jake Chua is the lead author on a paper that shows how a key enzyme that contributes to cholesterol production can be regulated – and destroyed – using a particular molecule.

    A team of UNSW scientists at the School of Biotechnology and Biomolecular Sciences led by Professor Andrew Brown have shown how a key enzyme that contributes to cholesterol production can be regulated – and destroyed – using a particular molecule.

    The findings have implications for the development of cholesterol-lowering drugs: knowing how to regulate this enzyme – squalene monooxygenase – may offer a new way to control its abundance in a bid to lower cholesterol levels.

    In the paper – published today in the Journal of Biological Chemistry – the scientists demonstrated how squalene monooxygenase, when linked to a particular molecule called ubiquitin, gets destroyed and inhibits the synthesis of cholesterol.

    The scientists showed that squalene monooxygenase has a “destruction code” that acts to bind ubiquitin when unlocked, initiating its own destruction.

    “Knowing the molecular mechanisms of how this enzyme – which plays a key role in cholesterol production – is regulated will allow us to understand how drugs can help maintain healthy levels of cholesterol in the cells of our body,” says UNSW PhD candidate Ngee Kiat (Jake) Chua, the paper’s lead author.

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    Squalene monooxygenase is depicted in blue (top and bottom). Under certain conditions, a helix in squalene monooxygenase (coiled structure, top right) is unravelled to reveal the destruction code (bottom blue squalene monooxygenase). The ubiquitin molecules are shown as purple spheres, linked to squalene monooxygenase in grey rods. Cholesterol is shown as ringed structures (yellow).

    For nearly twenty years, squalene monooxygenase has been proposed to be an enzyme in the pathway which should be investigated as another drug target to lower cholesterol.

    More recently, squalene monooxygenase has also been linked to high cholesterol in human cancers, including liver, breast and prostate cancers.

    Cholesterol is an essential component of the membranes that enclose all of our cells. Cholesterol is also the starting material for bile acids that allow us to digest fat as well as for steroid hormones like estrogen and testosterone. But high levels of cholesterol are still a major health concern, given their connection to heart disease.

    “What a lot of people don’t realise is that our body produces the bulk of cholesterol to meet our metabolic requirements – dietary cholesterol contributes a smaller proportion,” Mr Chua says.

    The body produces cholesterol through a pipeline called the cholesterol synthesis pathway. That’s the pipeline that statins – the most common cholesterol-lowering drugs – target. Statins limit cholesterol production by blocking one of the enzymes that is responsible for one early chemical reaction in this pathway.

    “Statins are not without their shortcomings – for example, they have been linked to muscle pain in some people who take them and some patients experience statins intolerance.

    “That’s why researchers are investigating other enzymes in the pathway, with hopes of finding alternative druggable targets to help lower cholesterol.

    “Enzymes are proteins that are made up of combinations of about 20 different building blocks called amino acids. In this paper, we reported that joining ubiquitin to a serine amino acid in squalene monooxygenase triggers its destruction. New knowledge of this initial chemical linkage raises new prospects to control cholesterol production. For instance, enhancing the formation of this chemical linkage speeds up the destruction of squalene monooxygenase,” Mr Chua says.

    The formation of the chemical linkage between ubiquitin and the serine amino acid on squalene monooxygenase is still not well-represented in the scientific literature

    “Why biology has introduced such an unusual chemical modification is still not well-understood,” Mr Chua says.

    “In the entire cholesterol synthesis pathway, which has about 20 steps each carried out by separate enzymes, squalene monooxygenase is the first-known enzyme to possess this unusual chemical linkage with ubiquitin.”

    With the emergence of newer techniques in modulating enzymes, including gene-editing and chemical molecules to trigger enzyme destruction, researchers are trying new approaches, rather than conventional drugs that simply block enzyme activity.

    “While our study has identified the molecular destruction code, future research should focus on identifying ways to unlock it for initiating the destruction of squalene monooxygenase as a strategy to lower cholesterol levels,” Mr Chua says.

    See the full article here .


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    Welcome to UNSW Australia (The University of New South Wales), one of Australia’s leading research and teaching universities. At UNSW, we take pride in the broad range and high quality of our teaching programs. Our teaching gains strength and currency from our research activities, strong industry links and our international nature; UNSW has a strong regional and global engagement.

    In developing new ideas and promoting lasting knowledge we are creating an academic environment where outstanding students and scholars from around the world can be inspired to excel in their programs of study and research. Partnerships with both local and global communities allow UNSW to share knowledge, debate and research outcomes. UNSW’s public events include concert performances, open days and public forums on issues such as the environment, healthcare and global politics. We encourage you to explore the UNSW website so you can find out more about what we do.

     
  • richardmitnick 11:55 am on May 13, 2019 Permalink | Reply
    Tags: , , Buildings of the future may be lit by collections of glowing plants and designed around an infrastructure of sunlight harvesting water transport and soil collecting and composting systems., Chemistry, Collaboration between MIT architect and chemical engineer could be at the center of new sustainable infrastructure for buildings., , Nanobionic plant technology,   

    From MIT News: “Ambient plant illumination could light the way for greener buildings” 

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    MIT Widget

    From MIT News

    May 9, 2019
    Becky Ham

    Collaboration between MIT architect and chemical engineer could be at the center of new sustainable infrastructure for buildings.

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    Glowing nanobionic watercress plants illuminate the Plant Properties Reading Room. Image: KVA Matx and Strano Research Group

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    Glowing nanobionic watercress illuminates the book “Paradise Lost.” Image: Strano Research Group

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    Pollinator Port – A Plant Properties room featuring an access port for light and pollinators to reach interior plants. Image: KVA Matx and Strano Research Group

    Buildings of the future may be lit by collections of glowing plants and designed around an infrastructure of sunlight harvesting, water transport, and soil collecting and composting systems. That’s the vision behind an interdisciplinary collaboration between an MIT architecture professor and a professor of chemical engineering.

    The light-emitting plants, which debuted in 2017, are not genetically modified to produce light. Instead, they are infused with nanoparticles that turn the plant’s stored energy into light, similar to how fireflies glow. “The transformation makes virtually any plant a sustainable, potentially revolutionary technology,” says Michael Strano, the Carbon P. Dubbs Professor of Chemical Engineering at MIT. “It promises lighting independent of an electrical grid, with ‘batteries’ you never need to charge, and power lines that you never need to lay.”

    But Strano and his colleagues soon realized that they needed partners who could expand the concept and understand its challenges and potential as part of a future of sustainable energy. He reached out to Sheila Kennedy, professor of architecture at MIT and principal at Kennedy and Violich Architecture, who is known for her work in clean energy infrastructure.

    “The science was so new and emergent that it seemed like an interesting design challenge,” says Kennedy. “The work of this design needed to move to a different register, which went beyond the problem of how the plant nanobionics could be demonstrated in architecture. As a design team, we considered some fundamental questions, such as how to understand and express the idea of plant lighting as a living, biological technology and how to invite the public to imagine this new future with plants.”

    “If we treat the development of the plant as we would just another light bulb, that’s the wrong way to go,” Strano adds.

    In 2017, Kennedy and Strano received a Professor Amar G. Bose Research Grant to build on their collaboration. The MIT faculty grants support unconventional, ahead-of-the-curve, and often interdisciplinary research endeavors that are unlikely to be funded through traditional avenues, yet have the potential to lead to big breakthroughs.

    Their first year of the Bose grant yielded several generations of the light-emitting watercress plants, which shine longer and brighter than the first experimental versions. The team is evaluating a new component to the nanobiotic plants that they call light capacitor particles. The capacitor, in the form of infused nanoparticles in the plant, stores spikes in light generation and “bleeds them out over time,” Strano explains. “Normally the light created in the biochemical reaction can be bright but fades quickly over time. Capacitive particles extend the duration of the generated plant light from hours to potentially days and weeks.”

    The researchers have added to their original patent on the light-emitting plant concept, filing a new patent on the capacitor and other components as well, Strano says.

    Designing for display

    As the nanobionic plant technology has advanced, the team is also envisioning how people might interact with the plants as part of everyday life. The architectural possibilities of their light-emitting plant will be on display within a new installation, “Plant Properties, a Future Urban Development,” at the Cooper Hewitt, Smithsonian Design Museum in New York opening May 10.

    Visitors to the installation, part of the 2019 “Nature—Cooper Hewitt Design Triennial” exhibition, can peek into a scaled architectural model of a New York City tenement building — which also serves as a plant incubator — to see the plants at work. The installation also demonstrates a roadmap for how an existing residential building could be adapted and transformed by design to support the natural growth of plants in a future when available energy could be very limited.

    “In Plant Properties, the nanobionic plant-based infrastructure is designed to use nature’s own resources,” says Kennedy. “The building harvests and transports sunlight, collects and recycles water, and enriches soil with compost.”

    The invitation to contribute to the Cooper Hewitt exhibition offered an unexpected way to demonstrate the plants’ possibilities, but designing an exhibit brought about a whole new set of challenges, Kennedy explains. “In the world of design museums, you’re usually asked to show something that’s already been exhibited, but this is new work and a new milestone in this project.”

    “We learned a lot about the care of plants,” Strano adds. “It’s one thing to make a laboratory demonstration, but it’s another entirely to make 33 continuous weeks of a public demonstration.”

    The researchers had to come up with a way to showcase the plants in a low-light museum environment where dirt and insects attracted by living plants are usually banished. “But rather than seeing this as a sort of insurmountable obstacle,” says Kennedy, “we realized that this kind of situation — how do you enable living plants to thrive in the enclosed setting of a museum — exactly paralleled the architectural problem of how to support significant quantities of plants growing inside buildings.”

    In the installation, multiple peepholes into the building model offer glimpses into the ways people in the building are living with the plants. Museum visitors are encouraged to join the experiment and crowdsource information on plant growth and brightness, by uploading their own photos of the plants to Instagram and tagging the MIT Plant Nanobiotics lab, using @plantproperties.

    The team is also collecting data on how the plants respond to the nanoparticles and other potential stresses. “The plants are actually under more stress from being in the museum environment than from the modifications that we introduce, but these effects need to be studied and mitigated if we are to use plants for indoor lighting,” Strano notes.

    Bright and nurturing futures

    Kennedy and Strano say the plants could be at the center of a new — but also “pre-eclectic” — idea in architecture.

    For most of human history, Kennedy explains, natural processes from sunlight to waste composting were part of the essential infrastructure of buildings. But these processes have been excluded in modern thinking or hidden away, preventing people from coming face to face with the environmental costs of energy infrastructure made from toxic materials and powered by fossil fuels.

    “People don’t question the impacts of our own mainstream electrical grid today. It’s very vulnerable, it’s very brittle, it’s so very wasteful and it’s also full of toxic material,” she says. “We don’t question this, but we need to.”

    “Lighting right now consumes a vast portion of our energy demand, approaching close to 20 percent of our global energy consumption, generating two gigatons of carbon dioxide per year,” Strano adds. “Consider that the plants replace more than just the lamp on your desk. There’s an enormous energy footprint that could potentially be replaced by the light-emitting plant.”

    The team is continuing to work on new ways to infuse the nanoparticles in the plants, so that they work over the lifetime of the plant, as well as experimenting on larger plants such as trees. But for the plants to thrive, architects will have to develop building infrastructure that integrates the plants into a new internal ecosystem of sunlight, water and waste disposal, Kennedy says.

    “If plants are to provide people with light, we need to keep plants healthy to benefit from everything they provide for us,” she says. “We think this is going to trigger a much more caring or nurturing relationship of people and their plants, or plants and the people that they illuminate.”

    See the full article here .


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    Please help promote STEM in your local schools.


    Stem Education Coalition

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    The mission of MIT is to advance knowledge and educate students in science, technology, and other areas of scholarship that will best serve the nation and the world in the twenty-first century. We seek to develop in each member of the MIT community the ability and passion to work wisely, creatively, and effectively for the betterment of humankind.

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  • richardmitnick 11:29 am on May 13, 2019 Permalink | Reply
    Tags: , Chemical Engineering/Energy/Biological Engineering Projects Laboratory, Chemistry,   

    From MIT News: “Making it real” 

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    MIT Widget

    From MIT News

    May 13, 2019
    Emily Makowski | School of Engineering

    Students in a cross-disciplinary projects course are working on real-world engineering problems posed by companies and MIT research labs.

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    Left to right: Sebastian Esquivel, Jenna Ahn, and Crystal Chen break down whey, normally a byproduct, into components for use in animal feed. Image: Lillie Paquette / School of Engineering.

    2
    Professor Gregory Rutledge advises two students in 10.26/27/29 (Chemical Engineering/Energy/Biological Engineering Projects Laboratory). Image: Lillie Paquette / School of Engineering.

    3
    Left to right: David Silverstein, Gianna Garza, and Connor Chung are researching how the enzyme PETase could be used to break down plastic. Image: Lillie Paquette / School of Engineering.

    Cloudy beige liquid swirls inside a large bioreactor resembling a French press as Jenna Ahn examines small flasks nearby. The lab where Ahn is working, in the subbasement of Building 66, has the feel of a beehive. She’s part of one of nine teams of undergraduates huddling in groups at their benches. Every now and then, someone darts off to use a larger piece of equipment among the shakers, spectrometers, flasks, scales, incubators, and bioreactors lining the walls.

    These students aren’t practicing routine distillations or titrations set up by an instructor. Each team of three or four is trying to solve a problem that doesn’t yet have an answer. In 10.26/27/29 (Chemical Engineering/Energy/Biological Engineering Projects Laboratory), students are focused on data-driven, applied research projects. They work on engineering problems posed by companies and by research labs from across the Institute, with the goal of finding solutions that can be applied to the real world.

    Ahn, a junior majoring in chemical and biological engineering, and her teammates are studying acid whey, a byproduct of cheese and yogurt. Although whey has nutritional value, it is often treated as a waste product, and its disposal can remove oxygen from waterways and kill aquatic life. While it can be purified and treated like wastewater, the process is expensive.

    Ahn’s team is using genetically engineered yeast to break down whey into nutritious components like sugars and omega-3 fatty acids, which could then be introduced back into the food chain. After combining the yeast with the whey, the team regularly checks dissolved oxygen and pH levels and monitors whether the yeast is breaking down the whey into its components. “This could be turned into a component of animal feed for cows and other animals,” says Ahn, gesturing to the swirling the mixture in her flask.

    Fundamentals in action

    Gregory Rutledge, the Lammot du Pont Professor of Chemical Engineering, has been the instructor in charge of 10.26/27/29 (Chemical Engineering/Energy/Biological Engineering Projects Laboratory) for about five years. The excitement among the course’s students stems from the knowledge that they are directly contributing to advancing technology, he says. “It’s a great motivator. They may have gotten fundamentals in their classes, but they may not have seen them in action.”

    The course has existed in its current form for about 30 years, Rutledge estimates. Its chemical engineering, biological engineering, and energy-related projects appeal to a wide variety of interests. Students are given project descriptions at the beginning of the semester and have flexibility in their choices.

    In the current format, students give presentations on their research progress throughout the semester and are evaluated by the 10.26/27/29 professors and their peers. At the end of the term, final presentations are judged by faculty from the entire Department of Chemical Engineering during a project showcase.

    The competitive element, Rutledge says, is just one part of how the course has changed over time. “It has evolved toward this organically, as we figure out what students need to know and how to best get that to them.”

    Each year, the focuses of the students’ projects change. Two of this year’s teams are working in collaboration with Somerville, Massachusetts, startup C16 Biosciences, trying to use yeast to produce a sustainable alternative to palm oil. The production of palm oil, which is primarily used for culinary and cosmetic purposes, is a leading cause of deforestation.

    “We’re trying to increase production of saturated fat sustainably,” explains Kaitlyn Hennacy, a junior majoring in chemical engineering. “This doesn’t require cutting down rainforests and could be a substitute in many applications.” Hennacy is examining a cuvette of yellow liquid in which there is a collection of bright orange blobs. The blobs’ color is a carotenoid pigment produced as a byproduct during the process. Her team is using seven different solvents, such as hexane and pentane, to extract a palm oil alternative from the yeast.

    “It’s the intersection of an energy-related project and a consumer project,” says Carlos Sendao, one of Hennacy’s teammates and a fellow chemical engineering major. “This is a challenge I knew to take.” Sendao is going to continue research on this project over the summer through the Undergraduate Research Opportunities Program (UROP) and the MIT Energy Initiative.

    Another team is looking into recycling plastics with an enzyme called PETase, which breaks down polyethylene terephthalate (PET), the type of plastic found in single-use water bottles. “One of the biggest constraints is time,” says Connor Chung, a junior majoring in chemical engineering. “We only have three to four months to learn as much as we can about this enzyme.”

    Life lessons

    Every year Rutledge is impressed with how much students learn and grow over the course of the semester. The problems they’re tackling aren’t easy, and working in teams presents challenges as students navigate the dynamics of group work.

    “They’re also learning a lot about life. They’re probably going to run into something in the future — whether it’s a boss, a team member, or a piece of lab equipment — that doesn’t work in the way they expect,” he says. “We try to give the students the tools if or when they come across this. And when they give those final presentations, you can see they really have evolved as engineers,” he adds.

    The approach seems to be effective, says Rutledge. “People will come back one, two, three years later when they’re working,” he says. “They say, ‘I learned so much. This is what I actually do.’”

    See the full article here .


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    Please help promote STEM in your local schools.


    Stem Education Coalition

    MIT Seal

    The mission of MIT is to advance knowledge and educate students in science, technology, and other areas of scholarship that will best serve the nation and the world in the twenty-first century. We seek to develop in each member of the MIT community the ability and passion to work wisely, creatively, and effectively for the betterment of humankind.

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  • richardmitnick 11:56 am on May 12, 2019 Permalink | Reply
    Tags: "A Bizarre Form of Water May Exist All Over the Universe", , Chemistry, Creating a shock wave that raised the water’s pressure to millions of atmospheres and its temperature to thousands of degrees., Experts say the discovery of superionic ice vindicates computer predictions which could help material physicists craft future substances with bespoke properties., Laboratory for Laser Energetics, , Superionic ice, Superionic ice can now claim the mantle of Ice XVIII., Superionic ice is black and hot. A cube of it would weigh four times as much as a normal one., Superionic ice is either another addition to water’s already cluttered array of avatars or something even stranger., Superionic ice would conduct electricity like a metal with the hydrogens playing the usual role of electrons., The discovery of superionic ice potentially solves decades-old puzzles about the composition of “ice giant” worlds., The fields around the solar system’s other planets seem to be made up of strongly defined north and south poles without much other structure., The magnetic fields emanating from Uranus and Neptune looked lumpier and more complex with more than two poles., The probe Voyager 2 had sailed into the outer solar system uncovering something strange about the magnetic fields of the ice giants Uranus and Neptune., , What giant icy planets like Uranus and Neptune might be made of,   

    From University of Rochester Laboratory for Laser Energetics via WIRED: “A Bizarre Form of Water May Exist All Over the Universe” 

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    From University of Rochester

    U Rochester’s Laboratory for Laser Energetics

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    WIRED

    1
    The discovery of superionic ice potentially solves the puzzle of what giant icy planets like Uranus and Neptune are made of. They’re now thought to have gaseous, mixed-chemical outer shells, a liquid layer of ionized water below that, a solid layer of superionic ice comprising the bulk of their interiors, and rocky centers. Credit: @iammoteh/Quanta Magazine.

    Recently at the Laboratory for Laser Energetics in Brighton, New York, one of the world’s most powerful lasers blasted a droplet of water, creating a shock wave that raised the water’s pressure to millions of atmospheres and its temperature to thousands of degrees. X-rays that beamed through the droplet in the same fraction of a second offered humanity’s first glimpse of water under those extreme conditions.

    The X-rays revealed that the water inside the shock wave didn’t become a superheated liquid or gas. Paradoxically—but just as physicists squinting at screens in an adjacent room had expected—the atoms froze solid, forming crystalline ice.

    “You hear the shot,” said Marius Millot of Lawrence Livermore National Laboratory in California, and “right away you see that something interesting was happening.” Millot co-led the experiment with Federica Coppari, also of Livermore.

    The findings, published this week in Nature, confirm the existence of “superionic ice,” a new phase of water with bizarre properties. Unlike the familiar ice found in your freezer or at the north pole, superionic ice is black and hot. A cube of it would weigh four times as much as a normal one. It was first theoretically predicted more than 30 years ago, and although it has never been seen until now, scientists think it might be among the most abundant forms of water in the universe.

    Across the solar system, at least, more water probably exists as superionic ice—filling the interiors of Uranus and Neptune—than in any other phase, including the liquid form sloshing in oceans on Earth, Europa and Enceladus. The discovery of superionic ice potentially solves decades-old puzzles about the composition of these “ice giant” worlds.

    Including the hexagonal arrangement of water molecules found in common ice, known as “ice Ih,” scientists had already discovered a bewildering 18 architectures of ice crystal. After ice I, which comes in two forms, Ih and Ic, the rest are numbered II through XVII in order of their discovery. (Yes, there is an Ice IX, but it exists only under contrived conditions, unlike the fictional doomsday substance in Kurt Vonnegut’s novel Cat’s Cradle.)

    Superionic ice can now claim the mantle of Ice XVIII. It’s a new crystal, but with a twist. All the previously known water ices are made of intact water molecules, each with one oxygen atom linked to two hydrogens. But superionic ice, the new measurements confirm, isn’t like that. It exists in a sort of surrealist limbo, part solid, part liquid. Individual water molecules break apart. The oxygen atoms form a cubic lattice, but the hydrogen atoms spill free, flowing like a liquid through the rigid cage of oxygens.

    3
    A time-integrated photograph of the X-ray diffraction experiment at the University of Rochester’s Laboratory for Laser Energetics. Giant lasers focus on a water sample to compress it into the superionic phase. Additional laser beams generate an X-ray flash off an iron foil, allowing the researchers to take a snapshot of the compressed water layer. Credit: Millot, Coppari, Kowaluk (LLNL)

    Experts say the discovery of superionic ice vindicates computer predictions, which could help material physicists craft future substances with bespoke properties. And finding the ice required ultrafast measurements and fine control of temperature and pressure, advancing experimental techniques. “All of this would not have been possible, say, five years ago,” said Christoph Salzmann at University College London, who discovered ices XIII, XIV and XV. “It will have a huge impact, for sure.”

    Depending on whom you ask, superionic ice is either another addition to water’s already cluttered array of avatars or something even stranger. Because its water molecules break apart, said the physicist Livia Bove of France’s National Center for Scientific Research and Pierre and Marie Curie University, it’s not quite a new phase of water. “It’s really a new state of matter,” she said, “which is rather spectacular.”

    Puzzles Put on Ice

    Physicists have been after superionic ice for years—ever since a primitive computer simulation led by Pierfranco Demontis in 1988 predicted [Physical Review Letters] water would take on this strange, almost metal-like form if you pushed it beyond the map of known ice phases.

    Under extreme pressure and heat, the simulations suggested, water molecules break. With the oxygen atoms locked in a cubic lattice, “the hydrogens now start to jump from one position in the crystal to another, and jump again, and jump again,” said Millot. The jumps between lattice sites are so fast that the hydrogen atoms—which are ionized, making them essentially positively charged protons—appear to move like a liquid.

    This suggested superionic ice would conduct electricity, like a metal, with the hydrogens playing the usual role of electrons. Having these loose hydrogen atoms gushing around would also boost the ice’s disorder, or entropy. In turn, that increase in entropy would make this ice much more stable than other kinds of ice crystals, causing its melting point to soar upward.

    But all this was easy to imagine and hard to trust. The first models used simplified physics, hand-waving their way through the quantum nature of real molecules. Later simulations folded in more quantum effects but still sidestepped the actual equations required to describe multiple quantum bodies interacting, which are too computationally difficult to solve. Instead, they relied on approximations, raising the possibility that the whole scenario could be just a mirage in a simulation. Experiments, meanwhile, couldn’t make the requisite pressures without also generating enough heat to melt even this hardy substance.

    As the problem simmered, though, planetary scientists developed their own sneaking suspicions that water might have a superionic ice phase. Right around the time when the phase was first predicted, the probe Voyager 2 had sailed into the outer solar system, uncovering something strange about the magnetic fields of the ice giants Uranus and Neptune.

    The fields around the solar system’s other planets seem to be made up of strongly defined north and south poles, without much other structure. It’s almost as if they have just bar magnets in their centers, aligned with their rotation axes. Planetary scientists chalk this up to “dynamos”: interior regions where conductive fluids rise and swirl as the planet rotates, sprouting massive magnetic fields.

    By contrast, the magnetic fields emanating from Uranus and Neptune looked lumpier and more complex, with more than two poles. They also don’t align as closely to their planets’ rotation. One way to produce this would be to somehow confine the conducting fluid responsible for the dynamo into just a thin outer shell of the planet, instead of letting it reach down into the core.

    But the idea that these planets might have solid cores, which are incapable of generating dynamos, didn’t seem realistic. If you drilled into these ice giants, you would expect to first encounter a layer of ionic water, which would flow, conduct currents and participate in a dynamo. Naively, it seems like even deeper material, at even hotter temperatures, would also be a fluid. “I used to always make jokes that there’s no way the interiors of Uranus and Neptune are actually solid,” said Sabine Stanley at Johns Hopkins University. “But now it turns out they might actually be.”

    Ice on Blast

    Now, finally, Coppari, Millot and their team have brought the puzzle pieces together.

    In an earlier experiment, published last February [Nature Physics], the physicists built indirect evidence for superionic ice. They squeezed a droplet of room-temperature water between the pointy ends of two cut diamonds. By the time the pressure raised to about a gigapascal, roughly 10 times that at the bottom of the Marianas Trench, the water had transformed into a tetragonal crystal called ice VI. By about 2 gigapascals, it had switched into ice VII, a denser, cubic form transparent to the naked eye that scientists recently discovered also exists in tiny pockets inside natural diamonds.

    Then, using the OMEGA laser at the Laboratory for Laser Energetics, Millot and colleagues targeted the ice VII, still between diamond anvils. As the laser hit the surface of the diamond, it vaporized material upward, effectively rocketing the diamond away in the opposite direction and sending a shock wave through the ice. Millot’s team found their super-pressurized ice melted at around 4,700 degrees Celsius, about as expected for superionic ice, and that it did conduct electricity thanks to the movement of charged protons.

    4
    Federica Coppari, a physicist at Lawrence Livermore National Laboratory, with an x-ray diffraction image plate that she and her colleagues used to discover ice XVIII, also known as superionic ice. Credit: Eugene Kowaluk/Laboratory for Laser Energetics

    With those predictions about superionic ice’s bulk properties settled, the new study led by Coppari and Millot took the next step of confirming its structure. “If you really want to prove that something is crystalline, then you need X-ray diffraction,” Salzmann said.

    Their new experiment skipped ices VI and VII altogether. Instead, the team simply smashed water with laser blasts between diamond anvils. Billionths of a second later, as shock waves rippled through and the water began crystallizing into nanometer-size ice cubes, the scientists used 16 more laser beams to vaporize a thin sliver of iron next to the sample. The resulting hot plasma flooded the crystallizing water with X-rays, which then diffracted from the ice crystals, allowing the team to discern their structure.

    Atoms in the water had rearranged into the long-predicted but never-before-seen architecture, Ice XVIII: a cubic lattice with oxygen atoms at every corner and the center of each face. “It’s quite a breakthrough,” Coppari said.

    “The fact that the existence of this phase is not an artifact of quantum molecular dynamic simulations, but is real—­that’s very comforting,” Bove said.

    And this kind of successful cross-check behind simulations and real superionic ice suggests the ultimate “dream” of material physics researchers might be soon within reach. “You tell me what properties you want in a material, and we’ll go to the computer and figure out theoretically what material and what kind of crystal structure you would need,” said Raymond Jeanloz, a member of the discovery team based at University of California, Berkeley. “The community at large is getting close.”

    The new analyses also hint that although superionic ice does conduct some electricity, it’s a mushy solid. It would flow over time, but not truly churn. Inside Uranus and Neptune, then, fluid layers might stop about 8,000 kilometers down into the planet, where an enormous mantle of sluggish, superionic ice like Millot’s team produced begins. That would limit most dynamo action to shallower depths, accounting for the planets’ unusual fields.

    Other planets and moons in the solar system likely don’t host the right interior sweet spots of temperature and pressure to allow for superionic ice. But many ice giant-sized exoplanets might, suggesting the substance could be common inside icy worlds throughout the galaxy.

    Of course, though, no real planet contains just water. The ice giants in our solar system also mix in chemical species like methane and ammonia. The extent to which superionic behavior actually occurs in nature is “going to depend on whether these phases still exist when we mix water with other materials,” Stanley said. So far, that isn’t clear, although other researchers have argued [Science] superionic ammonia should also exist.

    Aside from extending their research to other materials, the team also hopes to keep zeroing in on the strange, almost paradoxical duality of their superionic crystals. Just capturing the lattice of oxygen atoms “is clearly the most challenging experiment I have ever done,” said Millot. They haven’t yet seen the ghostly, interstitial flow of protons through the lattice. “Technologically, we are not there yet,” Coppari said, “but the field is growing very fast.”

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    University of Rochester Laboratory for Laser Energetics

    The Laboratory for Laser Energetics (LLE) is a scientific research facility which is part of the University of Rochester’s south campus, located in Brighton, New York. The lab was established in 1970 and its operations since then have been funded jointly; mainly by the United States Department of Energy, the University of Rochester and the New York State government. The Laser Lab was commissioned to serve as a center for investigations of high-energy physics, specifically those involving the interaction of extremely intense laser radiation with matter. Many types of scientific experiments are performed at the facility with a strong emphasis on inertial confinement, direct drive, laser-induced fusion, fundamental plasma physics and astrophysics using OMEGA. In June of 1995, OMEGA became the world’s highest-energy ultraviolet laser. The lab shares its building with the Center for Optoelectronics and Imaging and the Center for Optics Manufacturing. The Robert L. Sproull Center for Ultra High Intensity Laser Research was opened in 2005 and houses the OMEGA EP laser, which was completed in May 2008.

    The laboratory is unique in conducting big science on a university campus.[not verified in body] More than 180 Ph.D.s have been awarded for research done at the LLE.[2][3] During summer months the lab sponsors a program for high school students which involves local-area high school juniors in the research being done at the laboratory. Most of the projects are done on current research that is led by senior scientists at the lab.

    U Rochester Campus

    The University of Rochester is one of the country’s top-tier research universities. Our 158 buildings house more than 200 academic majors, more than 2,000 faculty and instructional staff, and some 10,500 students—approximately half of whom are women.

    Learning at the University of Rochester is also on a very personal scale. Rochester remains one of the smallest and most collegiate among top research universities, with smaller classes, a low 10:1 student to teacher ratio, and increased interactions with faculty.

     
  • richardmitnick 10:37 am on May 12, 2019 Permalink | Reply
    Tags: , By 2025 as much as half of the demand for lithium will be from the electric vehicle industry., Chemistry, Global demand for the metal is expected to rise at least 300 percent in the next 10 to 15 years., Lithium in its elemental form is soft and silvery and light with a density about half that of water., Lithium is useful for a lot more than batteries: a mood stabilizer for bipolar disorder; cosmetics; Military industrial automotive aircraft and marine applications; shock-resistant cookware and alumin, Lithium prices in global markets have been on a roller coaster in the last few years with a sharp spike in 2018 due to fears that there just might not be enough of the metal to go around., Lithium-the lightest metal on the periodic table-Period 2 Group 1, , Prospecting for new sources of lithium is booming., , The basic recipe for any kind of lithium-rich deposit includes volcanic rocks plus a lot of water and heat., The future of lithium is electrifying., The hunt to find and extract this “white gold” is also spurring new basic geology geochemistry and hydrology research., Worldwide there are three main sources of lithium: pegmatites; brines and clays.   

    From Science News- “Looking for Lithium: The lightest metal on the periodic table is key to clean energy’s future” 

    From Science News

    Carolyn Gramling
    May 7, 2019

    There’s a lot to learn about where and how to mine the lightest metal on the periodic table.

    Periodic Table 2014 NIST


    Lithium:Period 2 Group 1

    1
    LOOKING FOR LITHIUM Flamingos feast on tiny shrimp in the saline lagoons of Chile’s Salar de Atacama. Lithium and copper mining operations compete with the protected birds for the region’s scant water resources. Credit: saxlerb/iStock/Getty Images Plus

    The future of lithium is electrifying. Cars and trucks powered by lithium batteries rather than fossil fuels are, to many people, the future of transportation. Rechargeable lithium batteries are also crucial for storing energy produced by solar and wind power, clean energy sources that are a beacon of hope for a world worried about the rapidly changing global climate.

    Prospecting for new sources of lithium is booming [MDPI], fueled by expectations that demand for lightweight, rechargeable lithium batteries — to power electric vehicles, cell phones, laptops and renewable energy storage facilities — is about to skyrocket.

    Even before electric cars, lithium was a hot commodity [USGS], mined for decades for reasons that had nothing to do with batteries. Thanks to lithium’s physical properties, it is bizarrely useful, popping up in all sorts of products, from shock-resistant glass to medications. In 2018, those products accounted for nearly half of the global lithium demand, according to analyses by the Frankfurt-based Deutsche Bank. Batteries for consumer electronics, such as cell phones or laptops, accounted for another 25 percent or so of the demand. Electric vehicles accounted for most of the rest.

    That breakdown will soon be turned on its head: By 2025, as much as half of the demand for lithium will be from the electric vehicle industry, some projections suggest. Global demand for the metal is expected to rise at least 300 percent in the next 10 to 15 years, in large part because sales of electric vehicles are expected to increase dramatically. Right now, there are about 2 million electric vehicles on the road worldwide; by 2030, that number is projected to grow to over 24 million, according to the industry research firm Bloomberg New Energy Finance. Electric vehicle giant Tesla has been on a worldwide quest for lithium, inking deals to obtain lithium supplies from mining operations in the United States, Mexico, Canada and Australia.

    As a result, lithium prices in global markets have been on a roller coaster in the last few years, with a sharp spike in 2018 due to fears that there just might not be enough of the metal to go around. But those doomsday scenarios are probably a bit overwrought, says geologist Lisa Stillings of the U.S. Geological Survey in Reno, Nev. Lithium makes up about 0.002 percent of Earth’s crust, but in geologic terms, it isn’t particularly rare, Stillings says. The key, she adds, is knowing where it is concentrated enough to mine economically.

    2
    Demand for lightweight, rechargeable lithium batteries to power electric vehicles and other modern electronics is expected to climb. Credit:Tramino/iStock/Getty Images Plus

    To answer that question, researchers are studying how and where the forces of wind, water, heat and time combine to create rich deposits of the metal. Such places include the flat desert basins of the “lithium triangle” of Chile, Argentina and Bolivia; volcanic rocks called pegmatites in Australia, the United States and Canada; and lithium-bearing clays in the United States.

    The hunt to find and extract this “white gold” is also spurring new basic geology, geochemistry and hydrology research. Stillings and other scientists are examining how clays and brines form, how lithium might move between the two deposits when both occur in the same basin and how lithium atoms tend to position themselves within the chemical structure of the clay.

    Seeking simpler sources

    Lithium, in its elemental form, is soft and silvery and light, with a density about half that of water. It’s the lightest metal on the periodic table. The element was discovered in 1817 by Swedish chemist Johan August Arfwedson, who was analyzing a grayish mineral called petalite. Arfwedson identified aluminum, silicon and oxygen in the mineral, which together made up 96 percent of the mineral’s mass.

    The rest of the petalite, he determined, was made up of some sort of element that had chemical properties similar to potassium and sodium. All three elements are highly reactive with other charged particles, or ions, to form salts, are solid but soft at room temperature, have low melting points and tend to dissolve readily in water. Thanks to their similarities, these elements, along with rubidium, cesium and francium, were later grouped together as “alkali metals,” forming most of the periodic table’s Group 1 (SN: 1/19/19, p. 18). Lithium’s affinity for water helps explain how it moves through Earth’s crust and how it can become concentrated enough to mine.

    The basic recipe for any kind of lithium-rich deposit includes volcanic rocks plus a lot of water and heat, mixed well by active tectonics. Worldwide, there are three main sources of lithium: pegmatites, brines and clays.

    3
    Pegmatite rocks have large crystals and often contain minerals not found elsewhere, such as lithium-bearing spodumene or petalite. Credit:Géry Parent/Wikimedia Commons (CC BY 3.0)

    Most pegmatites are a type of granite formed out of molten magma. What makes pegmatites interesting is that they tend to contain a lot of incompatible elements, which resist forming solid crystals for as long as possible. The rocks form as the magma beneath a volcano cools very slowly. The magma’s chemical composition evolves over time. As elements drop out of the liquid to form solid crystals, other elements, like lithium, tend to linger in the liquid, becoming more and more concentrated. But eventually, even that magma cools and crystallizes, and the incompatibles are locked into the pegmatite.

    Before the 1990s, pegmatites in the United States were the primary source of mined lithium. But extracting lithium ore, primarily a mineral called spodumene, from the rock is costly. On top of the cost of actual mining, the rock has to be crushed and treated with acid and heat to extract the lithium in a commercially useful form.

    In the 1990s, a much cheaper source of lithium became an option. Just beneath the arid salt flats spanning large swaths of Chile, Argentina and Bolivia circulates salty, lithium-enriched groundwater. Miners pump the salty water to the surface, sequestering it into ponds and letting it evaporate in the sun. “Mother Nature does most of the work, so it’s really cheap,” Stillings says.

    What’s left behind after the evaporation is a sludgy, yellowish brine. To extract battery-grade lithium in commercially useful forms, particularly lithium carbonate and lithium hydroxide, the miners add different minerals to the brine, such as sodium carbonate and calcium hydroxide. Reactions with those minerals cause different types of salts to precipitate out of the solution, ultimately producing lithium minerals.

    4
    Pieces of a sediment core drilled at one potential future mining site in Clayton Valley, Nev., revealed a promising lithium-rich clay. Credit: Cypress Development Corp

    Compared with pegmatite extraction, the process for extracting lithium from the brine is extremely cheap; as a result, brine mining currently dominates the lithium market. But in the hunt for more lithium, the next generation of prospectors are looking to a third type of deposit: clay.

    Clays are the hardened remnants of ancient mud, produced by the slow settling of tiny grains of sediment, such as within a lake bed. To get lithium-enriched clay requires the right starting ingredients, particularly lithium-bearing rocks such as pegmatite and circulating groundwater. The groundwater leaches the lithium from the rocks and transports it to a lake where it becomes concentrated in the sediments.

    The western United States, it turns out, has all the right ingredients to make lithium-rich clay. In fact, in 2017 in Nature Communications, researchers suggested that some ancient supervolcano craters that became lakes, such as the Yellowstone caldera, would be excellent sources of lithium [Nature Communication].

    ______________________________________________________
    White gold

    Most of the world’s lithium sources (orange) are pegmatite mines in Australia and China and brine mines in Chile and Argentina. But planned mining ventures (blue) mean that the lithium rush will soon spread to the United States, Canada and Mexico.

    Known sources of lithium around the world

    5

    Source: USGS
    ______________________________________________________

    Several other types of lithium extraction may be on the horizon, Stillings says. Lithium-rich brines can also form in tectonically active geothermal regions, where there is a lot of heat in the subsurface. Geothermal power plants already pump up the superheated water to generate energy, then inject it back into the subsurface. Some facilities are experimenting with extracting other commercially valuable elements from the brine, including lithium, manganese and zinc. Hydraulic fracturing, or fracking, also involves pumping up brines from the subsurface that may contain high levels of dissolved metals, possibly including lithium. Although the lithium may not be present in very high concentrations, the extraction could still be economically worthwhile, if it’s a by-product of mining already going on.

    Revitalized research

    In December 2017, the White House issued an executive order directing the U.S. Department of the Interior to ramp up research on new sources of certain “critical minerals,” including ores bearing lithium. Citing the economy and national security, the order instructed government scientists to analyze each link in the minerals’ supply chains, from exploration to mining to production, in hopes that new sources could be found within U.S. borders.

    The United States isn’t alone in the rush to find lithium. China, the European Union and others are on the hunt for new sources. In January, a consortium of EU researchers launched a two-year initiative called the European Lithium Institute to become competitive in the lithium market.

    To kick off this new phase in lithium research, Stillings helped convene a symposium at the American Geophysical Union’s annual meeting in Washington, D.C., last December. “We would like to understand how lithium cycles through Earth’s crust,” Stillings says. “Lithium is very soluble; it likes to be in solution. However, we’ve learned that as it moves through the crust, it does interact with clays.”

    ______________________________________________________
    A multipurpose element

    Lithium is useful for a lot more than batteries. Below are some common products and the lithium compounds they contain.

    Mood stabilizer for bipolar disorder: Lithium has been used as a medication for conditions ranging from gout to mental disorders since the mid-19th century. Taken as lithium carbonate or lithium citrate, lithium has been in widespread use to treat acute mania, an aspect of bipolar disorder, since the 1970s.

    However, scientists still aren’t sure why the treatment works. Due to their smaller size, charged particles, or ions, of lithium may substitute for potassium, sodium or calcium ions in certain enzymes and chemicals in the brain. Substituting lithium may reduce the sensitivity of certain receptors, making them less likely to connect to brain chemicals such as norepinephrine, which is known to be overabundant during mania.

    Cosmetics: Lithium stearate acts as an emulsifier, keeping oils and liquids from separating in foundations, face powders, eye shadows and lipsticks. When added to face creams, a soft, greasy, lithium-bearing mineral called hectorite keeps the product smooth and spreadable.

    Military, industrial, automotive, aircraft and marine applications: When added to petroleum, lithium stearate creates a thick lubricating grease that is waterproof and tolerant of high and low temperatures.

    Shock-resistant cookware and aluminum foil: Compared with the other alkali metals, lithium atoms are small, particularly in their charged state. Lithium ions expand relatively little as they get hotter, so adding some lithium carbonate to glass or ceramics can make those products stronger and less likely to shatter when hot.
    ______________________________________________________

    Lithium isotopes — it has two, lithium-6 and lithium-7 — are one way to track this exchange. “They are like a fingerprint,” says Romain Millot, a geologist with the French Geological Survey and the University of Orléans in France. The different masses of the two isotopes influence how they move between water and solid rock: Lithium-6 prefers to leave the water and bind into clay grains, compared with lithium-7. The isotopes are also proving useful at revealing the influences of weathering, water flow and heat on concentrating lithium, Millot says.

    Because water is so important for concentrating lithium, researchers are shifting away from a classic “find the ore” framework, says Scott Hynek, a USGS geologist based in Salt Lake City. Instead, “we’re taking a more petroleum-like perspective,” he says. Scientists are tracking not just where deposits are, but how they might move: where the water flows, where the lithium-rich fluid could become trapped beneath a layer of hard, impermeable rock.

    Lithium prospecting is also taking a page from the hydrology playbook, using some classic tools of that trade to track the circulation of groundwater through the subsurface to suss out where lithium-rich deposits might end up. Isotopes of hydrogen, oxygen and helium are used to track how long the groundwater has been traveling through the subsurface as well as the types of rocks that the water has been in contact with.

    Faults, for example, can channel subsurface water, and therefore may play a big role in shaping where lithium deposits might form. “It’s an unresolved question,” Hynek says. “These are big-scale geologic controls on where high-lithium water goes.” He presented data at the AGU symposium suggesting that the highest lithium concentrations in a Chilean salt flat known as the Salar de Atacama occur near certain fault lines. That, he says, suggests the faults are helping to channel the groundwater and thereby concentrating the deposits.

    Do no harm

    One looming problem for lithium mining is that even “clean” energy isn’t completely clean. Extracting lithium from its ore and converting it into a commercially usable form such as lithium carbonate or lithium hydroxide can produce toxic waste, which can leak into the environment. Chemical leaks from a lithium mine in China’s Tibetan Plateau have repeatedly wreaked havoc on the environment since 2009, killing fish and livestock that drank from a nearby river.

    Even when Mother Nature is doing much of the work, such as in evaporation ponds, there can be negative effects on the environment. In South America, for example, the problem is water supply. The lithium triangle, which includes Salar de Atacama, is one of the driest places on Earth — and mining consumes a lot of water. And that’s producing a worrisome confluence of events. Just at the edges of the Salar de Atacama salt flats is a flamingo nesting habitat: brackish lagoons filled with brine shrimp. “One of the major oppositions to this mining activity is the impact it has potentially on flamingo populations,” Hynek says. The same water source in the Andes that feeds the subsurface lithium brine reservoir also, ultimately, fills the lagoons.

    5
    Brine mining in the Salar de Atacama consists of pumping salty, lithium-rich water into evaporation ponds (shown). The post-evaporation sludge is treated with minerals such as sodium carbonate to extract the lithium. Credit: Hemis/Alamy Stock Photo

    In fact, the water table is already dropping in some places in the region, and indigenous communities, as well as both Chilean and Argentinian authorities, are on high alert, Hynek says. “Chilean authorities are worried that [miners] will pump so much that the lagoon water levels will also drop.” In February, Chile announced new restrictions on water rights for miners operating in Salar de Atacama.

    Who’s to blame is the subject of a lot of debate. In addition to the lithium brine mining, copper mines high up in the Andes — where the groundwater originates — are extracting a substantial amount of water from the system. “The flamingos and the indigenous communities are literally stuck in the middle,” Hynek adds.

    Such big environmental concerns could hamper future prospects for mining in the region. “You’re making the brine in the same area where you’re sustaining these important biodiversity habitats,” says David Boutt, a hydrologist at the University of Massachusetts Amherst.

    There is so far little research on how water moves through the subsurface in dry areas with very low precipitation rates, such as South America’s lithium triangle, Boutt adds. “There are a lot of questions about where the water is coming from,” such as how variable the water flow rate is through the ground. “It can take a very long time for these systems to respond” to perturbations such as groundwater pumping.

    The effects of withdrawing the briny waters now might not be felt for perhaps decades. “A concern,” Boutt says, “is whether we are going to be waiting 100 years before something bad happens.”

    See the full article here .


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  • richardmitnick 8:18 am on May 11, 2019 Permalink | Reply
    Tags: , Beta-lactam; gamma-lactam: and delta-lactam molecules, , , Chemistry, In the ongoing arms race with humans and their antibiotics on one side and bacteria with their ability to evolve defenses to antibiotics on the other humans have enlisted a new ally: other bacteria.   

    From Caltech: “Directed Evolution Opens Door to New Antibiotics” 

    Caltech Logo

    From Caltech

    May 09, 2019
    Emily Velasco
    626‑395‑6487
    evelasco@caltech.edu

    1
    Caltech

    In the ongoing arms race with humans and their antibiotics on one side, and bacteria with their ability to evolve defenses to antibiotics on the other, humans have enlisted a new ally—other bacteria.

    Many common antibiotics, including the most famous antibiotic, penicillin, are based around a molecular structure known as a beta-lactam ring. These drugs, aptly named beta-lactam antibiotics, interfere with a bacterium’s ability to build its cell wall.

    2
    Penicillin. Credit: Caltech

    As bacteria develop resistance to existing antibiotics, researchers and pharmaceutical companies work to create new ones. That means a lot of work is done creating new kinds of beta-lactams, and that is where Frances Arnold’s lab enters the picture.

    6
    Frances H. Arnold

    The paramount challenge is to control precisely where along the molecule the reaction takes place. With traditional synthetic chemistry, chemists have to tack extra pieces onto molecules that they want to turn into beta-lactams. Without those extra pieces, the knots will end up tied in inconsistent spots, resulting in some loops that are large and some that are small. That’s undesirable for someone trying to manufacture a consistent batch of antibiotics. But the addition of those extra pieces makes the synthesis more complicated because additional steps are required to add them and still more steps to remove them after the looping is complete.

    3
    Caltech
    Beta-lactams are made by taking a chainlike molecule and looping it, kind of like taking one end of a string and tying it in a knot to the middle of the string.

    Graduate student Inha Cho and postdoctoral scholar Zhi-Jun Jia, both from Arnold’s lab, have developed something simpler by using directed evolution, a technique developed by Arnold, the Linus Pauling Professor of Chemical Engineering, Bioengineering and Biochemistry, and director of the Donna and Benjamin M. Rosen Bioengineering Center. In directed evolution, which Arnold developed in the 1990s and for which she received the 2018 Nobel Prize in Chemistry, enzymes are evolved in a lab until they behave in a desired way. The genetic code of a useful enzyme is transferred into bacteria like Escherichia coli. As the bacteria grow, divide, and go about their lives, they churn out the enzyme.

    In this case, Cho and Jia took an enzyme known as cytochrome P450, which has been a versatile workhorse in the Arnold lab, and evolved it to produce beta-lactams. Two other versions of enzymes were also created to construct other ring sizes of lactams. One version creates a gamma-lactam, a loop of four carbon atoms and one nitrogen atom. And the other version creates a delta-lactam, a loop of five carbon atoms and one nitrogen atom.

    6
    The enzyme developed in Arnold’s lab can create beta-lactam, gamma-lactam, and delta-lactam molecules. Credit: Caltech

    “We’re developing new enzymes with activity that cannot be found in nature,” says Cho. “Lactams can be found in many different drugs, but especially in antibiotics, and we’re always needing new ones.”

    Jia points out that the enzymes they have created are also incredibly efficient, with each molecule of enzyme capable of producing up to one million beta-lactam molecules. “They represent the most efficient enzymes created in our lab, and are ready for industrial applications,” Jia says.

    The paper, titled “Site-selective enzymatic C-H amidation for synthesis of diverse lactams” and co-authored by Arnold, appears in the May 10 issue of Science.

    Support for the research was provided by the National Science Foundation, the Joseph J. Jacobs Institute for Molecular Engineering for Medicine, and Deutsche Forschungsgemeinschaft.

    See the full article here .


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    Please help promote STEM in your local schools.


    Stem Education Coalition

    The California Institute of Technology (commonly referred to as Caltech) is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. “The mission of the California Institute of Technology is to expand human knowledge and benefit society through research integrated with education. We investigate the most challenging, fundamental problems in science and technology in a singularly collegial, interdisciplinary atmosphere, while educating outstanding students to become creative members of society.”

    Caltech campus

     
  • richardmitnick 7:32 am on May 8, 2019 Permalink | Reply
    Tags: "Arsenic-breathing life discovered in the tropical Pacific Ocean", , , Chemistry, ,   

    From University of Washington: “Arsenic-breathing life discovered in the tropical Pacific Ocean” 

    U Washington

    From University of Washington

    May 1, 2019
    Hannah Hickey

    Arsenic is a deadly poison for most living things, but new research shows that microorganisms are breathing arsenic in a large area of the Pacific Ocean. A University of Washington team has discovered that an ancient survival strategy is still being used in low-oxygen parts of the marine environment.

    “Thinking of arsenic as not just a bad guy, but also as beneficial, has reshaped the way that I view the element,” said first author Jaclyn Saunders, who did the research for her doctoral thesis at the UW and is now a postdoctoral fellow at the Woods Hole Oceanographic Institution and the Massachusetts Institute of Technology.

    The study was published this week in the Proceedings of the National Academy of Sciences.

    1
    Jaclyn Saunders (far right) fixes the line on a McLane instrument that pumps large volumes of seawater in order to extract the DNA. The instrument on the left measures properties such as temperature, salinity and depth and collects smaller samples of seawater. Noelle Held/Woods Hole Oceanographic Institution

    “We’ve known for a long time that there are very low levels of arsenic in the ocean,” said co-author Gabrielle Rocap, a UW professor of oceanography. “But the idea that organisms could be using arsenic to make a living — it’s a whole new metabolism for the open ocean.”

    The researchers analyzed seawater samples from a region below the surface where oxygen is almost absent, forcing life to seek other strategies. These regions may expand under climate change.

    “In some parts of the ocean there’s a sandwich of water where there’s no measurable oxygen,” Rocap said. “The microbes in these regions have to use other elements that act as an ‘electron acceptor’ to extract energy from food.”

    The most common alternatives to oxygen are nitrogen or sulfur. But Saunders’ early investigations suggested arsenic could also work, spurring her to look for the evidence.

    The team analyzed samples collected during a 2012 research cruise to the tropical Pacific, off the coast of Mexico. Genetic analyses on DNA extracted from the seawater found two genetic pathways known to convert arsenic-based molecules as a way to gain energy. The genetic material was targeting two different forms of arsenic, and authors believe that the pathways occur in two organisms that cycle arsenic back and forth between different forms.

    2
    A purple arsenic atom surrounded by four oxygen atoms is arsenate (left). An arsenic atom surrounded by three oxygen atoms is arsenite (right). The study found evidence of marine organisms that can convert one to the other to get energy in oxygen-deficient environments.Wikimedia

    Results suggest that arsenic-breathing microbes make up less than 1% of the microbe population in these waters. The microbes discovered in the water are probably distantly related to the arsenic-breathing microbes found in hot springs or contaminated sites on land.

    “What I think is the coolest thing about these arsenic-respiring microbes existing today in the ocean is that they are expressing the genes for it in an environment that is fairly low in arsenic,” Saunders said. “It opens up the boundaries for where we could look for organisms that are respiring arsenic, in other arsenic-poor environments.”

    3
    California’s Mono Lake is naturally high in arsenic and is known to host microbes that survive by breathing arsenic. The organisms that live in the marine environment are likely related to the ones on land. Pixabay

    Biologists believe the strategy is a holdover from Earth’s early history. During the period when life arose on Earth, oxygen was scarce in both the air and in the ocean. Oxygen became abundant in Earth’s atmosphere only after photosynthesis became widespread and converted carbon dioxide gas into oxygen.

    Early lifeforms had to gain energy using other elements, such as arsenic, which was likely more common in the oceans at that time.

    “We found the genetic signatures of pathways that are still there, remnants of the past ocean that have been maintained until today,” Saunders said.

    Arsenic-breathing populations may grow again under climate change. Low-oxygen regions are projected to expand, and dissolved oxygen is predicted to drop throughout the marine environment.

    “For me, it just shows how much is still out there in the ocean that we don’t know,” Rocap said.

    Saunders recently collected more water samples from the same region and is now trying to grow the arsenic-breathing marine microbes in a lab in order to study them more closely.

    “Right now we’ve got bits and pieces of their genomes, just enough to say that yes, they’re doing this arsenic transformation,” Rocap said. “The next step would be to put together a whole genome and find out what else they can do, and how that organism fits into the environment.”

    Co-author Clara Fuchsman collected the samples and led the DNA sequencing effort as a UW postdoctoral research scientist and now holds a faculty position at the University of Maryland. The other co-author is Cedar McKay, a research scientist in the UW School of Oceanography. The study was funded by a graduate fellowship from NASA and a research grant from the National Science Foundation.

    See the full article here .


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    Please help promote STEM in your local schools.

    Stem Education Coalition

    u-washington-campus
    The University of Washington is one of the world’s preeminent public universities. Our impact on individuals, on our region, and on the world is profound — whether we are launching young people into a boundless future or confronting the grand challenges of our time through undaunted research and scholarship. Ranked number 10 in the world in Shanghai Jiao Tong University rankings and educating more than 54,000 students annually, our students and faculty work together to turn ideas into impact and in the process transform lives and our world. For more about our impact on the world, every day.
    So what defines us —the students, faculty and community members at the University of Washington? Above all, it’s our belief in possibility and our unshakable optimism. It’s a connection to others, both near and far. It’s a hunger that pushes us to tackle challenges and pursue progress. It’s the conviction that together we can create a world of good. Join us on the journey.

     
  • richardmitnick 10:15 am on May 4, 2019 Permalink | Reply
    Tags: "U of T research looks at how to take the ‘petro’ out of the petrochemicals industry", , Chemistry, , , Phil De Luna, Renewable electrosynthesis,   

    From University of Toronto: “U of T research looks at how to take the ‘petro’ out of the petrochemicals industry” Phil De Luna 

    U Toronto Bloc

    From University of Toronto

    1
    Phil De Luna is the lead author of an article in Science that analyzes how green electricity and carbon capture could displace fossil fuels in the production of everything from fertilizer to textiles (photo by Tyler Irving)

    April 30, 2019
    Tyler Irving

    Fossil fuels are the backbone of the global petrochemicals industry, which provides the world’s growing population with fuels, plastics, clothing, fertilizers and more. A new research paper, published last week in Science, charts a course for how an alternative technology – renewable electrosynthesis – could usher in a more sustainable chemical industry and ultimately enable us to leave much more oil and gas in the ground.

    Phil De Luna, a PhD candidate in the Faculty of Applied Science & Engineering, is the paper’s lead author. His research involved designing and testing catalysts for electrosynthesis, and last November he was named to the Forbes 30 under 30 list of innovators in the category of Energy. He and his supervisor, Professor Ted Sargent, collaborated on the paper with an international team of researchers from Stanford University and TOTAL American Services, Inc.

    Writer Tyler Irving sat down with De Luna to learn more about how renewable electrosynthesis could take the “petro” out of petrochemicals.

    Can you describe the challenge you’re trying to solve?

    Our society is addicted to fossil fuels – they’re in everything from the plastics in your phone to the synthetic fibres in your clothes. A growing world population and rising standards of living are driving demand higher every year.

    Changing the system requires a massive global transformation. In some areas, we have alternatives – for example, electric vehicles can replace internal combustion engines. Renewable electrosynthesis could do something similar for the petrochemical industry.

    What is renewable electrosynthesis?

    Think about what the petrochemical industry does: It takes heavy, long-chain carbon molecules and uses high heat and pressure to break them down into basic chemical building blocks. Then, those building blocks get reassembled into plastics, fertilizers, fibres, etc.

    Imagine that instead of using fossil fuels, you could use CO2 from the air. And instead of doing the reactions at high temperatures and pressures, you could make the chemical building blocks at room temperature using innovative catalysts and electricity from renewable sources, such as solar or hydro power. That’s renewable electrosynthesis.

    Once we do that initial transformation, the chemical building blocks fit into our existing infrastructure, so there is no change in the quality of the products. If you do it right, the overall process is carbon neutral or even carbon negative if powered completely by renewable energy.

    Plants also take CO2 from the air and make it into materials such as wood, paper and cotton. What is the advantage of electrosynthesis?

    The advantages are speed and throughput. Plants are great at turning CO2 into materials, but they also use their energy for things like metabolism and reproduction, so they aren’t very efficient. It can take 10 to 15 years to grow a tonne of usable wood. Electrosynthesis would be like putting the CO2 capture and conversion power of 50,000 trees into a box the size of a refrigerator.

    Why don’t we do this today?

    It comes down to cost. You need to prove that the cost to make a chemical building block via electrosynthesis is on par with the cost of producing it the conventional way.

    Right now there are some limited applications. For example, most of the hydrogen used to upgrade heavy oil comes from natural gas, but about four per cent is now produced by electrolysis – that is, using electricity to split water into hydrogen and oxygen. In the future, we could do something similar for carbon-based building blocks.

    What did your analysis find?

    We determined that there are two main factors: The first is the cost of electricity itself, and the second is the electrical-to-chemical conversion efficiency.

    In order to be competitive with conventional methods, electricity needs to cost less than four cents per kilowatt-hour, and the electrical-to-chemical conversion efficiency needs to be 60 per cent or greater.

    How close are we?

    There are some places in the world where renewable energy from solar can cost as little as two or three cents per kilowatt-hour. Even in a place like Quebec, which has abundant hydro power, there are times of the year where electricity is sold at negative prices, because there is no way to store it. So, from an economic potential perspective, I think we’re getting close in a number of important jurisdictions.

    Designing catalysts that can raise the electrical-to-chemical conversion efficiency is harder, and it’s what I spent my thesis doing. For ethylene, the best I’ve seen is about 35 per cent efficiency, but for some other building blocks, such as carbon monoxide, we’re approaching 50 per cent.

    Of course, all this has been done in labs – it’s a lot harder to scale that up to a plant that can make kilotonnes per day. But I think there are some applications out there that show promise.

    Can you give an example of what renewable electrosynthesis would look like?

    Let’s take ethylene, which is by volume the world’s most-produced petrochemical. You could in theory make ethylene using CO2 from the air – or from an exhaust pipe – using renewable electricity and the right catalyst. You could sell the ethylene to a plastic manufacturer, who would make it into plastic bags or lawn chairs or whatever.

    At the end of its life, you could incinerate this plastic – or any other carbon-intensive form of waste – capture the CO2, and start the process all over again. In other words, you’ve closed the carbon loop and eliminated the need for fossil fuels.

    What do you think the focus of future research should be?

    I’ve actually just taken a position as the program director of the clean energy materials challenge program at the National Research Council of Canada. I am building a $21 million collaborative research program, so this is something I think about a lot.

    We’re currently targeting parts of the existing petrochemical supply chain that could easily be converted to electrosynthesis. There is the example I mentioned above, which is the production of hydrogen for oil and gas upgrading using electrolysis.

    Another good building block to target would be carbon monoxide, which today is primarily produced from burning coal. We know how to make it via electrosynthesis, so if we could get the efficiency up, that would be a drop-in solution.

    How does renewable electrosynthesis fit into the large landscape of strategies to reduce emissions and combat climate change?

    I’ve always said that there’s no silver bullet. Instead, I think what we need is what I call a “silver buckshot” approach. We need recycled building materials, we need more efficient LEDs for lighting, we need better solar cells and better batteries.

    But even if emissions from the electricity grid and the transportation network dropped to zero tomorrow, it wouldn’t do anything to help the petrochemical industry that supplies so many of the products we use every day. If we can start by electrifying portions of the supply chain, that’s the first step to building an alternative system.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Founded in 1827, the University of Toronto has evolved into Canada’s leading institution of learning, discovery and knowledge creation. We are proud to be one of the world’s top research-intensive universities, driven to invent and innovate.

    Our students have the opportunity to learn from and work with preeminent thought leaders through our multidisciplinary network of teaching and research faculty, alumni and partners.

    The ideas, innovations and actions of more than 560,000 graduates continue to have a positive impact on the world.

     
  • richardmitnick 4:12 pm on April 29, 2019 Permalink | Reply
    Tags: , “Accidentally dropping electronics such as a laptop or cellphone is a common scenario that may lead to the failure of the device” said Julio D’Arcy, Chemistry, In some cases energy storage devices catch on fire due to impact-caused failure., It produces an interwoven mat of polymer nanofibers with a textile-like structure that is flexible and ideal for storing energy in a supercapacitor., , The chance of impact damage will only increase as electronics become more flexible and worn on the human body., , We have carefully designed the nanostructure orientation so that a polymer film assembles parallel to a rusted surface.   

    From Washington University in St.Louis: “Takes a licking and keeps on storing” 

    Wash U Bloc

    From Washington University in St.Louis

    April 23, 2019
    Talia Ogliore
    talia.ogliore@wustl.edu

    1
    By controlling the formation of rust in solution, researchers in Arts & Sciences grew a micrometer-thick porous mat of conducting fibers affixed to a soft, pliable layer of organic plastic. This new energy storage device can withstand a hammer striking it more than 40 times. (Image: D’Arcy laboratory / Washington University)

    Researchers at Washington University in St. Louis made an energy storage device that can withstand a hammer striking it more than 40 times. The shatterproof supercapacitor is also nonflammable, unlike lithium-ion batteries. The new work is the cover story of the April 23 issue of the journal Sustainable Energy and Fuels.

    2
    Julio D’Arcy,

    “Accidentally dropping electronics, such as a laptop or cellphone, is a common scenario that may lead to the failure of the device,” said Julio D’Arcy, assistant professor of chemistry in Arts & Sciences. “In some cases, energy storage devices catch on fire due to impact-caused failure. The chance of impact damage will only increase as electronics become more flexible and worn on the human body.”

    Hongmin Wang, a PhD candidate in chemistry who works in D’Arcy’s lab, led the effort to create the new material.

    By controlling the formation of rust in solution, researchers grew a micrometer-thick porous mat of conducting fibers affixed to a soft, pliable layer of organic plastic. The result is somewhat similar to an open-faced sandwich.

    “This is the same mechanism that is responsible for the formation of rust on the surface of a wet piece of steel,” D’Arcy said. “Here, we have carefully designed the nanostructure orientation so that a polymer film assembles parallel to a rusted surface. It produces an interwoven mat of polymer nanofibers with a textile-like structure that is flexible and ideal for storing energy in a supercapacitor.”

    The researchers bent their new material to different angles over and over again. They hammered it repeatedly, and they also tested it against an impact equivalent to a car collision at 30 mph. The same amount of impact would fracture other materials such as metal and carbon.

    The device held up well against these extreme tests: after the first hammer strike, it retained 80 percent of its ability to store energy at peak efficiencies; after 40 repeated strikes, it was still at 74 percent.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Wash U campus

    Washington University’s mission is to discover and disseminate knowledge, and protect the freedom of inquiry through research, teaching, and learning.

    Washington University creates an environment to encourage and support an ethos of wide-ranging exploration. Washington University’s faculty and staff strive to enhance the lives and livelihoods of students, the people of the greater St. Louis community, the country, and the world.

     
  • richardmitnick 11:29 am on April 29, 2019 Permalink | Reply
    Tags: , , , Buckminsterfullerene molecule with 60 carbon atoms, Chemistry, ,   

    From AAS NOVA: “Hubble Confirms Interstellar Buckyballs” 

    AASNOVA

    From AAS NOVA

    24 April 2019
    Susanna Kohler

    1
    Buckminsterfullerene, a molecule that consists of 60 carbon atoms. Recent research has discovered evidence of this molecule in the diffuse interstellar medium. [NASA/JPL-Caltech]

    From a jumble of confusing clues in Hubble observations of interstellar space, scientists have picked out evidence of a celebrity molecule: ionized Buckminsterfullerene, or buckyballs.

    Sorting Out Diffuse Signals

    What makes up the tenuous gas and dust that pervades our galaxy, filling the space between stars? What kinds of complex molecules can form naturally in our universe, outside of the potentially contrived conditions of Earth-side laboratories? Where might these molecules form, and how are they distributed throughout space?

    2
    Hubble spectra of seven heavily-reddened interstellar sightlines (top seven black lines) and four unreddened standard stars (bottom four lines). The red line at the top indicates a laboratory spectrum for C60+. Positions of the four absorption features associated with C60+ are marked with vertical dashed lines. Click to enlarge. [Cordiner et al. 2019]

    These are among the many open questions regarding the chemistry of our universe. One particular, longstanding puzzle for astronomers is the cause of what’s known as “diffuse interstellar bands”: hundreds of broad absorption features that appear in optical to near-infrared spectra of reddened stars.

    These features are not caused by the stars themselves, so they must be due to absorption of light by the diffuse interstellar medium (ISM) between us and the stars. But the jumble of hundreds of features — and the unknown conditions under which they are produced — has made it incredibly challenging to identify the individual molecules present in the diffuse ISM.

    A new study led by Martin Cordiner (NASA Goddard SFC; Catholic University of America) presents observations from the Hubble Space Telescope — thus avoiding the additional complication of absorption features from the Earth’s atmosphere — that explore these diffuse interstellar bands further. Hubble’s sightlines toward 11 stars provide confirmation of one special molecule within this jumble: Buckminsterfullerene.

    A Celebrity Molecule

    The C60+ ion, formally known as Buckminsterfullerene and informally known as a “buckyball”, is an enormous molecule consisting of 60 carbon atoms arranged in a soccer-ball shape. Previously, the largest known molecules definitively detected in the diffuse interstellar medium contained no more than three atoms heavier than hydrogen — so the detection of buckyballs represents a dramatic increase in the known size limit!

    Cordiner and collaborators use a novel scanning technique to obtain ultra-high signal-to-noise spectra of seven stars that are significantly reddened by obscuring ISM and four stars that are not. They then search for absorption signals at four wavelengths — 9348, 9365, 9428, and 9577 Å — predicted by laboratory experiments to be associated with C60+.

    3
    Mean spectra for the observed sightlines for reddened (black, top) and unreddened (gray, bottom) stars, around four predicted absorption features for C60+. The laboratory comparison spectra for C60+ are overlaid as red lines. [Cordiner et al. 2019]

    The authors find obtain reliable detections of the three strongest of these absorption lines in the spectra toward the seven reddened stars, and find no sign of this absorption in the four unobscured stars. The 9348 Å absorption was not detected, but as this is predicted to be a very weak feature, this result is not surprising. The relative strengths of the three detected lines also fit with laboratory predictions.

    The consistency of Cordiner and collaborators’ results with prediction provides the strongest confirmation yet of the presence of buckyballs in the diffuse ISM. This detection may help us to characterize other components of the diffuse ISM and better understand the conditions under which complex molecules exist in the extreme, low-density environment of interstellar space.

    Citation

    “Confirming Interstellar C60+ Using the Hubble Space Telescope,” M. A. Cordiner et al 2019 ApJL 875 L28.
    https://iopscience.iop.org/article/10.3847/2041-8213/ab14e5/meta

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    1

    AAS Mission and Vision Statement

    The mission of the American Astronomical Society is to enhance and share humanity’s scientific understanding of the Universe.

    The Society, through its publications, disseminates and archives the results of astronomical research. The Society also communicates and explains our understanding of the universe to the public.
    The Society facilitates and strengthens the interactions among members through professional meetings and other means. The Society supports member divisions representing specialized research and astronomical interests.
    The Society represents the goals of its community of members to the nation and the world. The Society also works with other scientific and educational societies to promote the advancement of science.
    The Society, through its members, trains, mentors and supports the next generation of astronomers. The Society supports and promotes increased participation of historically underrepresented groups in astronomy.
    The Society assists its members to develop their skills in the fields of education and public outreach at all levels. The Society promotes broad interest in astronomy, which enhances science literacy and leads many to careers in science and engineering.

    Adopted June 7, 2009

     
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