AI-based Method Could Speed Development Of Specialized Nanoparticles

Researchers Find New DNA Structure in Living Human Cells

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According to Breaking Science News

A team of scientists from the Garvan Institute of Medical Research and the Universities of New South Wales and Sydney has identified a new DNA structure — called the intercalated motif (i-motif) — inside living human cells.

Deep inside the cells in our body lies our DNA. The information in the DNA code — all 6 billion A, C, G and T letters — provides precise instructions for how our bodies are built, and how they work.

The iconic ‘double helix’ shape of DNA has captured the public imagination since 1953, when James Watson and Francis Crick famously uncovered the structure of DNA.

However, it’s now known that short stretches of DNA can exist in other shapes, in the laboratory at least — and scientists suspect that these different shapes might play an important role in how and when the DNA code is ‘read.’

“When most of us think of DNA, we think of the double helix. This research reminds us that totally different DNA structures exist — and could well be important for our cells,” said co-lead author Dr. Daniel Christ, from the Kinghorn Centre for Clinical Genomics at the Garvan Institute of Medical Research and St Vincent’s Clinical School at the University of New South Wales.

“The i-motif is a four-stranded ‘knot’ of DNA,” added co-lead author Dr. Marcel Dinger, also from the Garvan Institute of Medical Research and the University of New South Wales.

“In the knot structure, C letters on the same strand of DNA bind to each other — so this is very different from a double helix, where ‘letters’ on opposite strands recognize each other, and where Cs bind to Gs [guanines].”

Although researchers have seen the i-motif before and have studied it in detail, it has only been witnessed in vitro — that is, under artificial conditions in the laboratory, and not inside cells. In fact, they have debated whether i-motif DNA structures would exist at all inside living things — a question that is resolved by the new findings.

To detect the i-motifs inside cells, Dr. Christ, Dr. Dinger and their colleagues developed a precise new tool — a fragment of an antibody molecule — that could specifically recognize and attach to i-motifs with a very high affinity.

Until now, the lack of an antibody that is specific for i-motifs has severely hampered the understanding of their role.

Crucially, the antibody fragment didn’t detect DNA in helical form, nor did it recognize ‘G-quadruplex structures’ (a structurally similar four-stranded DNA arrangement).

With the new tool, the team uncovered the location of ‘i-motifs’ in a range of human cell lines.

Using fluorescence techniques to pinpoint where the i-motifs were located, the study authors identified numerous spots of green within the nucleus, which indicate the position of i-motifs.

The scientists showed that i-motifs mostly form at a particular point in the cell’s ‘life cycle’ — the late G1 phase, when DNA is being actively ‘read.’

They also showed that i-motifs appear in some promoter regions — areas of DNA that control whether genes are switched on or off — and in telomeres, ‘end sections’ of chromosomes that are important in the aging process.

“We think the coming and going of the i-motifs is a clue to what they do. It seems likely that they are there to help switch genes on or off, and to affect whether a gene is actively read or not,” said study first author Dr. Mahdi Zeraati, also from the Garvan Institute of Medical Research and the University of New South Wales.

“We also think the transient nature of the i-motifs explains why they have been so very difficult to track down in cells until now,” Dr. Christ added.

“It’s exciting to uncover a whole new form of DNA in cells — and these findings will set the stage for a whole new push to understand what this new DNA shape is really for, and whether it will impact on health and disease,” Dr. Dinger said.

The team’s results appear in the journal Nature Chemistry.

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This article and images were originally posted on [Breaking Science News] April 24, 2018 at 03:11PM. Credit to Author and Breaking Science News | ESIST.T>G>S Recommended Articles Of The Day

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But now, researchers at Virginia Tech have synthesized a biodegradable alternative to polyolefins using a new catalyst and the polyester polymer, and this breakthrough could eventually have a profound impact on sustainability efforts.

Rong Tong, assistant professor in the Department of Chemical Engineering and affiliated faculty member of Macromolecules Innovation Institute (MII), led the team of researchers, whose findings were recently published in the journal Nature Communications.

One of the largest challenges in polymer chemistry is controlling the tacticity or the stereochemistry of the polymer. When multiplying monomer subunits into the macromolecular chain, it’s difficult for scientists to replicate a consistent arrangement of side-chain functional groups stemming off the main polymer chain. These side-chain functional groups greatly affect a polymer’s physical and chemical properties, such as melting temperature or glass-transition temperature, and regular stereochemistry leads to better properties.

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Researchers develop ‘self-healing’ robotics material

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Traditional electronics are made from rigid and brittle materials. However, a new ‘self-healing’ electronic material allows a soft robot to recover its circuits after it is punctured, torn or even slashed with a razor blade.

Made from liquid metal droplets suspended in a flexible silicone elastomer, it is softer than skin and can stretch about twice its length before springing back to its original size.

Soft Robotics & Biologically Inspired Robotics at Carnegie Mellon University. Video: Mouser Electronics 

‘The material around the damaged area automatically creates new conductive pathways, which bypass the damage and restore connectivity in the circuit,’ explains first author Carmel Majidi at Carnegie Mellon University in Pittsburgh, Pennsylvania. The rubbery material could be used for wearable computing, electronic textiles, soft field robots or inflatable extra-terrestrial housing.

‘There is a sweet spot for the size of the droplets,’ says Majidi. ‘We had to get the size not so small that they never rupture and form electronic connections, but not so big they would rupture even under light pressure.’

To read the full article, by Anthony King, in C&I, the members’ magazine for SCI, click here. 

A battery that eats CO2

By Khai Trung Le

A new type of battery developed by researchers at MIT could be made partly from carbon dioxide captured from power plants. Rather than attempting to convert carbon dioxide to specialized chemicals using metal catalysts, which is currently highly challenging, this battery could continuously convert carbon dioxide into a solid mineral carbonate as it discharges.

The battery is made from lithium metal, carbon, and an electrolyte that the researchers designed. While still based on early-stage research and far from commercial deployment, the new battery formulation could open up new avenues for tailoring electrochemical carbon dioxide conversion reactions, which may ultimately help reduce the emission of the greenhouse gas to the atmosphere.

Currently, power plants equipped with carbon capture systems generally use up to 30 percent of the electricity they generate just to power the capture, release, and storage of carbon dioxide. Anything that can reduce the cost of that capture process, or that can result in an end product that has value, could significantly change the economics of such systems, the researchers say.

Betar Gallant, Assistant Professor of Mechanical Engineering at MIT, said, ‘Carbon dioxide is not very reactive. Trying to find new reaction pathways is important.’Ideally, the gas would undergo reactions that produce something worthwhile, such as a useful chemical or a fuel. However, efforts at electrochemical conversion, usually conducted in water, remain hindered by high energy inputs and poor selectivity of the chemicals produced.

The team looked into whether carbon-dioxide-capture chemistry could be put to use to make carbon-dioxide-loaded electrolytes — one of the three essential parts of a battery — where the captured gas could then be used during the discharge of the battery to provide a power output.

The team developed a new approach that could potentially be used right in the power plant waste stream to make material for one of the main components of a battery. By incorporating the gas in a liquid state, however, Gallant and her co-workers found a way to achieve electrochemical carbon dioxide conversion using only a carbon electrode. The key is to preactivate the carbon dioxide by incorporating it into an amine solution.

‘What we’ve shown for the first time is that this technique activates the carbon dioxide for more facile electrochemistry,’ Gallant says. ‘These two chemistries — aqueous amines and nonaqueous battery electrolytes — are not normally used together, but we found that their combination imparts new and interesting behaviors that can increase the discharge voltage and allow for sustained conversion of carbon dioxide.’

The battery is made from lithium metal, carbon, and an electrolyte that the researchers designed. While still based on early-stage research and far from commercial deployment, the new battery formulation could open up new avenues for tailoring electrochemical carbon dioxide conversion reactions, which may ultimately help reduce the emission of the greenhouse gas to the atmosphere.

PINning down future problems

Study finds hackers could use brainwaves to steal passwords

Researchers at the University of Alabama at Birmingham suggest that brainwave-sensing headsets, also known as EEG or electroencephalograph headsets, need better security after a study reveals hackers could guess a user’s passwords by monitoring their brainwaves.

EEG headsets are advertised as allowing users to use only their brains to control robotic toys and video games specifically developed to be played with an EEG headset. There are only a handful on the market, and they range in price from $150 to $800.

Nitesh Saxena, Ph.D., associate professor in the UAB College of Arts and Sciences Department of Computer and Information Sciences, and Ph.D. student Ajaya Neupane and former master’s student Md Lutfor Rahman, found that a person who paused a video game and logged into a bank account while wearing an EEG headset was at risk for having their passwords or other sensitive data stolen by a malicious software program.

“These emerging devices open immense opportunities for everyday users,” Saxena said. “However, they could also raise significant security and privacy threats as companies work to develop even more advanced brain-computer interface technology.”

Saxena and his team used one EEG headset currently available to consumers online and one clinical-grade headset used for scientific research to demonstrate how easily a malicious software program could passively eavesdrop on a user’s brainwaves. While typing, a user’s inputs correspond with their visual processing, as well as hand, eye and head muscle movements. All these movements are captured by EEG headsets. The team asked 12 people to type a series of randomly generated PINs and passwords into a text box as if they were logging into an online account while wearing an EEG headset, in order for the software to train itself on the user’s typing and the corresponding brainwave.

“In a real-world attack, a hacker could facilitate the training step required for the malicious program to be most accurate, by requesting that the user enter a predefined set of numbers in order to restart the game after pausing it to take a break, similar to the way CAPTCHA is used to verify users when logging onto websites,” Saxena said.

The team found that, after a user entered 200 characters, algorithms within the malicious software program could make educated guesses about new characters the user entered by monitoring the EEG data recorded. The algorithm was able to shorten the odds of a hacker’s guessing a four-digit numerical PIN from one in 10,000 to one in 20 and increased the chance of guessing a six-letter password from about 500,000 to roughly one in 500.

EEG has been used in the medical field for more than half a century as a noninvasive method for recording electrical activity in the brain. Electrodes are placed on the surface of the scalp to detect brain waves. An EEG machine then amplifies the signals and records them in a wave pattern on graph paper or a computer. EEG can be combined with a brain-computer interface to allow a person to control external devices. This technology was once highly expensive and used mostly for scientific research, like the production of neuroprosthetic applications to help disabled patients control prosthetic limbs by thinking about the movements. However, it is now being marketed to consumers in the form of a wireless headset and is becoming popular in the gaming and entertainment industries.

“Given the growing popularity of EEG headsets and the variety of ways in which they could be used, it is inevitable that they will become part of our daily lives, including while using other devices,” Saxena said. “It is important to analyze the potential security and privacy risks associated with this emerging technology to raise users’ awareness of the risks and develop viable solutions to malicious attacks.”

One potential solution proposed by Saxena and his team is the insertion of noise anytime a user types a password or PIN while wearing an EEG headset.

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NASA blasts off Mars lander, InSight

Vandenberg AFB CA (AFP) May 05, 2018 NASA on Saturday blasted off its latest Mars lander, InSight, designed to perch on the surface and listen for “Marsquakes” ahead of eventual human missions to explore the Red Planet. “Three, two, one, liftoff!” said a NASA commentator as the spacecraft launched on a dark, foggy morning atop an Atlas V rocket at 4:05 am Pacific time (1105 GMT) from Vandenberg Air Force Base in California, m Full article

Solar powered sea slugs shed light on search for perpetual green energy

The sea slug, Elysia chlorotica, steals millions of green-colored plastids, which are like tiny solar panels, from algae. Credit: Karen N. Pelletreau/University of Maine

A Northeast sea slug sucks raw materials from algae to provide its lifetime supply of solar-powered energy, according to a study by Rutgers University-New Brunswick, USA.

‘It’s a remarkable feat because it’s highly unusual for an animal to behave like a plant and survive solely on photosynthesis,’ said Debashish Bhattacharya, senior author of the study and professor in the Department of Biochemistry and Microbiology at Rutgers-New Brunswick. ‘The broader implication is in the field of artificial photosynthesis. That is, if we can figure out how the slug maintains stolen, isolated plastids to fix carbon without the plant nucleus, then maybe we can also harness isolated plastids for eternity as green machines to create bioproducts or energy. The existing paradigm is that to make green energy, we need the plant or alga to run the photosynthetic organelle, but the slug shows us that this does not have to be the case.’

The sea slug Elysia chlorotica, a mollusk that can grow to more than 2 inches long, has been found in the intertidal zone between Nova Scotia, Canada, and Martha’s Vineyard, Massachusetts, as well as in Florida. Juvenile sea slugs eat the nontoxic brown alga Vaucheria litorea and become photosynthetic – or solar-powered – after stealing millions of algal plastids, which are like tiny solar panels, and storing them in their gut lining, according to the study published online in the journal Molecular Biology and Evolution.

This particular alga is an ideal food source because it does not have walls between adjoining cells in its body and is essentially a long tube loaded with nuclei and plastids, Bhattacharya said. ‘When the sea slug makes a hole in the outer cell wall, it can suck out the cell contents and gather all of the algal plastids at once,’ he said.

Read the full study here: Cheong Xin Chan, Pavel Vaysberg, Dana C Price, Karen N Pelletreau, Mary E Rumpho, Debashish Bhattacharya. Active Host Response to Algal Symbionts in the Sea Slug Elysia chlorotica. Molecular Biology and Evolution, 2018; DOI: 10.1093/molbev/msy061