New class of antibiotics discovered in soil gives hope in battle against drug-resistant pathogens

Finding new drugs to treat life-threatening antibiotic-resistant infections is critical to human health, but only one new class – teixobactin – has been discovered in the last 33 years. The World Health Organization has labeled development of such drugs a high priority and in 2015, the Obama administration released an action plan to combat antibiotic-resistant bacteria.

Scientists trawling through thousands of soil samples have discovered a whole new class of antibiotics capable of killing drug-resistant bacteria. The chemical, which has been named malacidin, appears to be non-toxic in humans and is effective in tackling several multidrug-resistant bacteria such as Meticillin-resistant Staphylococcus aureus (MRSA), raising hopes that it could be used to develop new lines of  treatment in the never-ending war against antibiotic-resistant pathogens.

Petridish with hospital superbug MRSA. SISIRAT/Shuttershock

The most effective antibiotic drugs so far have come from organisms in the environment that produce antibiotics naturally to defend against bacteria. For instance, penicillin was discovered from a fungus and vancomycin was found in bacteria that lives in dirt. Soil is a good place to look for antibiotics as it is an environment where multiple types of bacteria naturally compete for resources and use a range of exotic chemical compounds to kill each other.

“Environmental microbes are in a continuous antibiotic arms race that is likely to select for antibiotic variants capable of circumventing existing resistance mechanisms,” the authors wrote.

The malacidin chemical, identified by Dr Sean Brady and his laboratory at Rockefeller University, New York, works by attacking a fundamental step in bacterial growth, essentially interfering with a major building block that the bacteria use to build and repair their outer membrane. Initial tests showed that malacidin was not toxic to human cells, and did not induce resistance in S. aureus bacteria, even after 20 days. By comparison, bacteria in the lab have developed antibiotic resistance to the drug rifamycin in a single day.

In their study, published in the journal Nature Microbiology, the authors cautioned that it is only effective against gram-positive bacteria, species that have a very thick cell wall, and therefore, would not be effective against gram-negative bacteria. Nonetheless, the breakthrough suggests there may be more similar compounds  like malacidin yet to be discovered in our natural environment.

Research on malacidin has just begun and bringing them to pharmacies will require years of additional research and clinical trials. “The ability to tap into the world’s microbiome in a systematic way could lead to the discovery of new natural products, which historically have been the most productive source of antibiotics so far,” said Brady.

It is also a promising sign that this new class follows closely after the 2015 discovery of teixobactin. Prior to that there had been a 30-year drought, prompting dire warnings of a post-antibiotic apocalypse if bacteria continued to adapt and develop resistance to antibiotics.

 

 

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Origami-inspired artificial robot muscles can lift 1,000 times their own weight

Research into soft robotics has progressed immensely over the last decade as researchers around the world have experimented with different materials and designs, with the aim of allowing once rigid machines with limited robotic range of motion to bend, flex, and move more like living organisms than industrial hardware. However, till date, increased flexibility and dexterity had a trade-off of reduced strength, as softer materials are generally not as strong or resilient as inflexible ones, which limits their use.

All this is set to change now that researchers at the Wyss Institute at Harvard University and MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) have created origami-inspired artificial muscles that add strength to soft robots, allowing them to lift objects that are up to 1,000 times their own weight using only air or water pressure. The study is published in Proceedings of the National Academy of Sciences (PNAS).

The study suggests that the muscles could be used to provide extraordinary strength to robots, yet allowing them to operate with precision and dexterity.

“We were very surprised by how strong the actuators [aka, “muscles”] were. We expected they’d lift a higher maximum functional weight than ordinary soft robots, but we didn’t expect a thousand-fold increase. It’s like giving these robots superpowers,” says Daniela Rus, Ph.D., Professor of Electrical Engineering and Computer Science at MIT and one of the senior authors of the paper.

“Artificial muscle-like actuators are one of the most important grand challenges in all of engineering,” adds Rob Wood, Ph.D., corresponding author of the paper and founding core faculty member of the Wyss Institute. “Now that we have created actuators with properties similar to natural muscle, we can imagine building almost any robot for almost any task.”

Each artificial muscle consists of an inner “skeleton” that can be made of various materials, such as a metal coil or a sheet of plastic folded into a certain pattern, surrounded by air or fluid and sealed inside a plastic or textile bag that serves as the “skin.” A vacuum applied to the inside of the bag initiates the muscle’s movement by causing the skin to collapse onto the skeleton, creating tension that drives the motion. Incredibly, no other power source or human input is required to direct the muscle’s movement; it is determined entirely by the shape and composition of the skeleton.

Origami-inspired artificial muscles are capable of lifting up to 1,000 times their own weight, simply by applying air or water pressure. Credit: Shuguang Li / Wyss Institute at Harvard University

“One of the key aspects of these muscles is that they’re programmable, in the sense that designing how the skeleton folds defines how the whole structure moves. You essentially get that motion for free, without the need for a control system,” says first author Shuguang Li, Ph.D., a Postdoctoral Fellow at the Wyss Institute and MIT CSAIL. This approach allows the muscles to be very compact and simple, and thus more appropriate for mobile or body-mounted systems that cannot accommodate large or heavy machinery.

“When creating robots, one always has to ask, ‘Where is the intelligence – is it in the body, or in the brain?’” says Rus. “Incorporating intelligence into the body (via specific folding patterns, in the case of our actuators) has the potential to simplify the algorithms needed to direct the robot to achieve its goal. All these actuators have the same simple on/off switch, which their bodies then translate into a broad range of motions.”

Not only can the artificial muscles move in many ways, they do so with impressive resilience. They can generate about six times more force per unit area than mammalian skeletal muscle can, and are also incredibly lightweight; a 2.6-gram muscle can lift a 3-kilogram object, which is the equivalent of a mallard duck lifting a car. Additionally, a single muscle can be constructed within ten minutes using materials that cost less than $1, making them cheap and easy to test and iterate.

These muscles can be powered by a vacuum, a feature that makes them safer than most of the other artificial muscles currently being tested. “A lot of the applications of soft robots are human-centric, so of course it’s important to think about safety,” says Daniel Vogt, M.S., co-author of the paper and Research Engineer at the Wyss Institute. “Vacuum-based muscles have a lower risk of rupture, failure, and damage, and they don’t expand when they’re operating, so you can integrate them into closer-fitting robots on the human body.”

“In addition to their muscle-like properties, these soft actuators are highly scalable. We have built them at sizes ranging from a few millimeters up to a meter, and their performance holds up across the board,” Wood says. This feature means that the muscles can be used in numerous applications at multiple scales, such as miniature surgical devices, wearable robotic exoskeletons, transformable architecture, deep-sea manipulators for research or construction, and large deployable structures for space exploration.

It seems like the robots of the future are going to be much more life-like in their appearance and range of movement than even the T-800s of Terminator fame.

Could an old wives’ tonic prove the cure for asthma?

Asthma is a common inflammatory disease of the airways of the lungs, which varies largely in its severity and duration from person to person.

When exposed to certain asthma triggers (such as cold air, exercise, pollen and viruses), the sensitive airways of asthmatic individuals react. They can become red and inflamed, which causes the muscles to tighten and produce excess mucus. This causes the airways to get constricted and thereby severely reduce breath flow, thus triggering asthma.

Asthma is thought to be caused by a combination of genetic and environmental factors. Environmental factors include exposure to air pollution and allergens.

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A child using an asthma inhaler. 358 million people worldwide are reported to be suffering from asthma in 2015.

Common asthma symptoms include shortness of breath, wheezing, coughing, and a feeling of tightness in the chest. These episodes may occur a few times a day or a few times per week.

On one end, sufferers experience what is euphemistically termed as’ wheezing’, a milder cousin of asthma which can often be relieved by prescription  beta-2 agonists such as salbutamol and corticosteroids taken via inhalation.

On the other extreme, full-blown asthma attacks can be life-threatening as severe shortness of breath restricts oxygen supply to the brain and other vital organs. Treatment in this case invariably involves hospitalization and intravenous administration of corticosteroids, in addition to nebulization until symptoms subside, and the patient is able to breathe well enough on his own.

Currently, there is no cure for asthma, and medical research into asthma has been largely focused on treatment rather than discovering means to cure or prevent it from occurring in the first place. Asthma was always known as a disease that can be largely controlled, but never cured.

New research led by Dr Pawan Sharma from the UTS School of Life Sciences and The Woolcock Institute of Medical Research, Australia seems set to create a precedent  in the hitherto poorly researched field of asthma prevention.

Dr Sharma and a team of American researchers investigated whether the activation of bitter taste receptors could thwart the symptoms of asthma in mice.

They found that bitter substances not only reduced common symptoms of the disease in mice, but also prevented allergic inflammation and structural changes to the airways. This could be a game-changer for the 300 million people worldwide that live with asthma.

The research team induced mice with allergic asthma and tested the effects of chloroquine and quinine on various features of the disease. Chloroquine and quinine are substances that stimulate bitter taste receptors owing to their bitter taste. Both are used as anti-malaria drugs and as ingredients for tonic water, lending the latter its characteristic bitter taste.

Tonic water has been ubiquitous since its creation in British India in the 1800s to combat endemic malaria. (Img)

When inhaled, these two compounds activated the taste-2 receptor protein (TAS2R). In doing so, they also block the allergic reaction in the lungs, thereby preventing asthma from occurring in the first place.

Past research has already shown that TAS2R agonists, compounds that activate the receptors, lead to relaxation in the airway of the lungs. But researchers hadn’t been able to test whether it was able to prevent the airway inflammation associated with asthma.

Excitingly, the spray didn’t just stop airway inflammation in the mice- it was also able to limit other characteristics of asthma, including mucus accumulation and associated structural changes to the airway.

The researchers confirmed these findings on human lung cells, finding that both chloroquine and quinine blocked the immune cells from reaching the airway, thereby limiting inflammation that could lead to an asthma attack.

“We used both in vitro and in vivo approaches using human airway cells and mouse models of asthma to study the effectiveness of novel bitter compounds. We do not have an effective anti-asthma therapy that targets disease progression. Our current research on taste receptors is crucial in identifying new classes of drugs that can be an effective asthma treatment option in future,” Dr Sharma said.

Dr Sharma is now preparing to collaborate with US researchers to synthesize new bitter compounds that may be developed as inhaled therapy for humans.

New Perovskite mineral can generate electricity from sunlight, heat, and movement- all at once

The holy grail in the quest for utilizing renewable energy, it may be argued, lies in harnessing it in a sustainable manner.

Solar energy faces the limitation of being able to provide us with usable energy only when there is sunlight. A device that can convert heat into electricity is useless in the absence of heat. And piezoelectric devices which can convert movement to electricity are useless when they are still.

It is in light of this that the discovery of a new type of mineral has created a storm in the fast-paced field of renewable energy. The mineral, a type of perovskite, has the right properties to extract energy from multiple sources at the same time- turning solar, heat, and kinetic energy into electricity. The clincher being that all this can be done at room temperature.

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Non-distorted cubic structure of a perovskite with chemical formula ABX3.

Since the first perovskite solar cell was invented back in 2009, these minerals have been positioned as the ‘next big thing’ in renewable energy technology.

Perovskite solar cells have proven to be cheaper and more efficient than traditional silicon solar cells, and their efficiency levels have increased from 3.8 percent in 2009 to 22.1 percent in 2016, making them the fastest-advancing solar technology to date.

In order to try and create a mineral that could harness energy from multiple sources, a team from the University of Oulu in Finland researched different types of perovskite minerals, and they’ve identified the perfect candidate – KBNNO (or Ba, Ni co-modified KNbO3 nanocrystals).

While the mineral at present is not efficient enough to power something as large as your home the way perovskite solar cells could, the researchers say it could be used in electronic devices like phones and laptops, and the various ‘smart’ gadgets that will soon be filling our homes and city streets.

“This will push the development of the Internet of Things and smart cities, where power-consuming sensors and devices can be energy sustainable,” says one of the team, Yang Bai.

Like all perovskites, KBNNO is a ferroelectric material, which means it’s filled with tiny electric dipoles that work analogous to tiny compass needles.

When a compass is exposed to a magnet, the needles move in a certain direction. Similarly, when ferroelectric materials experience changes in temperature, their dipoles misalign, and this triggers an electric current. This property is known as pyroelectricity.

KBNNO is also photovoltaic, which means it can generate an electric current when exposed to sunlight, as well as piezoelectric, which means that it can convert changes in pressure caused by motion into electricity.

Researchers in the past have identified KBNNO’s photovoltaic capabilities, and have even seen hints of its other properties, but only at extremely low, impractical temperatures – a couple of hundred degrees Celsius below freezing, the University of Oulu team points out.

When they tested its properties at room temperature, they found that, while it was outclassed by other perovskites when it came to generating electricity from single sources of energy, the fact that it could generate electricity from three different sources at once could make it valuable in certain situations. After all, in the game of harnessing energy that would be lost to entropy otherwise, every little joule counts.

The researchers also report that they have found a way to modify the composition of KBNNO to improve its heat and pressure-sensitive properties, so they predict its efficiency levels will increase with further tweaks.

“It is possible that all these properties can be tuned to a maximum point,” says Bai.

Different types of so-called hybrid energy harvesters have been developed in the past, but the researchers say what makes this mineral special is that all three properties are right there in the crystal structure – you don’t need to keep adding layers of different materials to capture multiple sources of energy.

As the team reports in their paper, “This type of perovskite ferroelectric solid-solution could show a strong piezoelectric and/or pyroelectric response, together with a considerable photovoltaic effect, thus providing a unique opportunity to develop a novel multi-source energy harvester or multi-functional sensor based on a single material.”

As might be expected, it will take a long time before enough research and refinement is done on this wonder material before it is commercially viable enough for large-scale deployment. It is hoped that KBNNO, or one of its derivatives, might prove itself to be a potent antidote that could end our addictive dependence on fossil fuels to sustain our energy needs.

 

Internal Combustion engine 2.0?

The quest to replace the internal combustion engine as the primary driver of road transportation has been making some serious headway since the turn of the century, driven by an industry wide push led by visionary automakers such as Tesla, and sustained efforts on the parts of governments and environmental activists  to counter the deleterious effects of climate change on our planet.

Today, electric cars having largely made the crucial cultural transition from nerd oddity to mainstream acceptance, aided by the many inherent advantages of electric motors such as over 90% energy efficiency, and instantaneous torque delivery even at 0 RPM, and the cool factor that Tesla has brought into the mix. However, the limitations of portable energy storage technology has been holding it back from completely ridding the field of internal combustion engines.

To add to what might prove to be a complete resurgence of fossil-fuel based transportation technology, an Israeli start-up firm, Aquarius Engines, claims that it has completely reinvented the internal combustion engine.

The company claims that their new engine will completely rewrite the classic design of the internal combustion engine with its multiple thrusting pistons, replacing them with a single piston that moves from side-to-side. It has fewer than 20 parts and powers the vehicle through this single side-to-side action of the solitary piston, the company said.

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Gal Fridman, co-founder of Aquarius Engines, believes the firm’s single-piston car engine had “the highest efficiency you will probably meet”.

The fewer number of moving parts and reduced engine complexity makes production much easier and less expensive. It also reduces the power demands on the engine.

Fewer parts also means less wear and tear, less chances of breakdowns, and overall improvement in the life of the engine, thereby drastically reducing cost-of-ownership.

In tests by the German engineering company FEV, the Aquarius engine’s efficiency was more than double that of traditional engines.

Such efficiency is vital as countries seek to reduce their dependence on fossil fuels for their transportation needs, the burning of which is a main cause of climate change.

“It is the highest efficiency you will probably meet,” co-founder Gal Fridman told AFP at the company’s offices near the Israeli commercial capital of Tel Aviv.

Aquarius also states that its engine has an, “exceptionally high power-to-weight/size ratio.

According to a report by AFP, Aquarius Engines is already in talks with the French auto manufacturer Peugeot to sell it their engines which are being priced at only $100 per unit.”It has the lowest emissions and the highest power-to-weight ratio.” A Peugeot spokesman said: “We are discussing with them, as with many other start-ups, without obligation or a specific project.”

For Peugeot and others, the engine could help them compete with the growing popularity of electric cars, John German, senior fellow at the International Council on Clean Transportation, said.

He said the engine would work best as part of a plug-in hybrid system, with manufacturers looking at “the idea of putting a smaller, inexpensive, range extender” alongside a battery and motor.

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Shaul Yakobi, inventor and co-founder of Aquarius Engines, poses next to the single piston Aquarius combustion engine.

The radical new design of the Aquarius engine would necessitate a stark divergence in conventional engine manufacturing techniques. It remains to be seen whether the company would be able to bring it to the market in a cost-effective manner in time to keep pace with the rapid innovations being done to eliminate the one major Achilles heel of electric car technology: limited battery capacity.

A full 120 years after internal combustion engines replaced the humble horse as the driving force for automotive transportation, the race is on. Once again.

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