New Molecule Kills The Flu Virus

Influenza is one of the most widespread viral diseases and constitutes a major public health problem. For some, it means spending a week in bed; for others, it could lead to hospitalization or, in the most severe cases, death. Scientists at the Ecole Polytechnique Fédérale de Lausanne (EPFL)’s Supramolecular Nano-Materials and Interfaces Laboratory (SuNMIL) within the School of Engineering, working in association with the team headed by Caroline Tapparel, a professor at the University of Geneva’s Department of Microbiology and Molecular Medicine, have synthesized a compound that can kill the virus that causes influenza. Their discovery paves the way to effective drug therapies against the seasonal disease.

With the flu virus, the risk of a pandemic is high,” says Francesco Stellacci, the EPFL professor who heads SuNMIL. “Scientists have to update the vaccine every year because the strain mutates, and sometimes the vaccine turns out to be less effective. So it would be good to also have antivirals that could limit the effects of large-scale infection.

“Antiviral drugs already exist, and Tamiflu is the most well-known. But it has one major drawback – it has to be taken within 36 hours of infection or it loses its efficacy completely. And with influenza, symptoms generally start appearing 24 hours after infection. “By the time patients seek medical treatment, it’s often too late for Tamiflu,” explained Stellacci. “In addition, for antivirals to really work, they have to be virucidal – that is, they have to irreversibly inhibit viral infectivity. But today that’s not the case.

The research has been published in Advanced Science.

Source: https://actu.epfl.ch/

How To Protect Cells From Premature Aging

Molecules that accumulate at the tip of chromosomes are known to play a key role in preventing damage to our DNA. Now, researchers at EPFL (Ecole Polytechnique Fédérale de Lausanne in Switzerland) have unraveled how these molecules home in on specific sections of chromosomes—a finding that could help to better understand the processes that regulate cell survival in aging and cancer.

Much like an aglet of a shoelace prevents the end of the lace from fraying, stretches of DNA called telomeres form protective caps at the ends of chromosomes. But as cells divide, telomeres become shorter, making the protective cap less effective. Once telomeres get too short, the cell stops dividing. Telomere shortening and malfunction have been linked to cell aging and age-related diseases, including cancer.

A new study by EPFL researchers shows how RNA species called TERRA muster at the tip of chromosomes, where they help to prevent telomere shortening and premature cell aging

Scientists have known that RNA species called TERRA help to regulate the length and function of telomeres. Discovered in 2007 by postdoc Claus Azzalin in the team of EPFL Professor Joachim Lingner, TERRA belongs to a class of molecules called noncoding RNAs, which are not translated into proteins but function as structural components of chromosomes. TERRA accumulates at chromosome ends, signaling that telomeres should be elongated or repaired.

However, it was unclear how TERRA got to the tip of chromosomes and remained there. “The telomere makes up only a tiny bit of the total chromosomal DNA, so the question is ‘how does this RNA find its home?’”, Lingner says. To address this question, postdoc Marianna Feretzaki and others in the teams of Joachim Lingner at EPFL and Lumir Krejci at Masaryk University set out to analyze the mechanism through which TERRA accumulates at telomeres, as well as the proteins involved in this process. The findings are published in Nature.

By visualizing TERRA molecules under a microscope, the researchers found that a short stretch of the RNA is crucial to bring it to telomeres. Further experiments showed that once TERRA reaches the tip of chromosomes, several proteins regulate its association with telomeres. Among these proteins, one called RAD51 plays a particularly important role, Lingner says.

RAD51 is a well-known enzyme that is involved in the repair of broken DNA molecules. The protein also seems to help TERRA stick to telomeric DNA to form a so-called “RNA-DNA hybrid molecule”. Scientists thought this type of reaction, which leads to the formation of a three-stranded nucleic acid structure, mainly happened during DNA repair. The new study shows that it can also happen at chromosome ends when TERRA binds to telomeres. “This is paradigm-shifting,” Lingner says.

The researchers also found that short telomeres recruit TERRA much more efficiently than long telomeres. Although the mechanism behind this phenomenon is unclear, the researchers hypothesize that when telomeres get too short, either due to DNA damage or because the cell has divided too many times, they recruit TERRA molecules. This recruitment is mediated by RAD51, which also promotes the elongation and repair of telomeres. “TERRA and RAD51 help to prevent accidental loss or shortening of telomeres,” Lingner says. “That’s an important function.”

Source: https://actu.epfl.ch/

Nanodevice 100 Times Faster Than The Usual Transistor

Researchers at Ecole Polytechnique Fédérale de Lausanne (EPFL) in Switzerland have developed a nanodevice that operates more than 10 times faster than today’s fastest transistors, and about 100 times faster than the transistors you have on your computers. This new device enables the generation of high-power terahertz waves. These waves, which are notoriously difficult to produce, are useful in a rich variety of applications ranging from imaging and sensing to high-speed wireless communications. The high-power picosecond operation of these device also hold immense promise to some advanced medical treatment techniques such as cancer therapy. The team’s pioneering compact source, described today in Nature, paves the way for untold new applications.

Terahertz (THz) waves fall between microwave and infrared radiation in the electromagnetic spectrum, oscillating at frequencies of between 100 billion and 30 trillion cycles per second. These waves are prized for their distinctive properties: they can penetrate paper, clothing, wood and walls, as well as detect air pollution. THz sources could revolutionize security and medical imaging systems.

What’s more, their ability to carry vast quantities of data could hold the key to faster wireless communications.

THz waves are a type of non-ionizing radiation, meaning they pose no risk to human health. The technology is already used in some airports to scan passengers and detect dangerous objects and substances.

Despite holding great promise, THz waves are not widely used because they are costly and cumbersome to generate. But new technology developed by researchers at EPFL could change all that. The team at the Power and Wide-band-gap Electronics Research Laboratory (POWERlab), led by Prof. Elison Matioli, built a nanodevice (1 nanometer = 1 millionth of a millimeter) that can generate extremely high-power signals in just a few picoseconds, or one trillionth of a second, – which produces high-power THz waves.

The technology, which can be mounted on a chip or a flexible medium, could one day be installed in smartphones and other hand-held devices. The work first-authored by Mohammad Samizadeh Nikoo, a PhD student at the POWERlab, has been published in the journal Nature.

Source: https://actu.epfl.ch/

Amputee Feels In Real-Time With Bionic Hand

Nine years after an accident caused the loss of his left hand, Dennis Aabo Sørensen from Denmark became the first amputee in the world to feel – in real-time – with a sensory-enhanced prosthetic hand that was surgically wired to nerves in his upper arm. Silvestro Micera and his team at EPFL Center for Neuroprosthetics (Ecole Polytechnique Fédérale de Lausanne in Switzerland) and SSSA (Italy) developed the revolutionary sensory feedback that allowed Sørensen to feel again while handling objects. A prototype of this bionic technology was tested in February 2013 during a clinical trial in Rome under the supervision of Paolo Maria Rossini at Gemelli Hospital (Italy). The study is published in the February 5, 2014 edition of Science Translational Medicine, and represents a collaboration called Lifehand 2 between several European universities and hospitals.
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The sensory feedback was incredible,” reports the 36 year-old amputee from Denmark. “I could feel things that I hadn’t been able to feel in over nine years.” In a laboratory setting wearing a blindfold and earplugs, Sørensen was able to detect how strongly he was grasping, as well as the shape and consistency of different objects he picked up with his prosthetic. “When I held an object, I could feel if it was soft or hard, round or square.

Micera and his team enhanced the artificial hand with sensors that detect information about touch. This was done by measuring the tension in artificial tendons that control finger movement and turning this measurement into an electrical current. But this electrical signal is too coarse to be understood by the nervous system. Using computer algorithms, the scientists transformed the electrical signal into an impulse that sensory nerves can interpret. The sense of touch was achieved by sending the digitally refined signal through wires into four electrodes that were surgically implanted into what remains of Sørensen’s upper arm nerves.

This is the first time in neuroprosthetics that sensory feedback has been restored and used by an amputee in real-time to control an artificial limb,” says Micera. “We were worried about reduced sensitivity in Dennis’ nerves since they hadn’t been used in over nine years,” says Stanisa Raspopovic, first author and scientist at EPFL and SSSA. These concerns faded away as the scientists successfully reactivated Sørensen’s sense of touch.

Source: https://actu.epfl.ch/

How To Offer Commercially Attractive Carbon-Capturing

Chemical engineers from the Ecole Polytechnique Fédérale de Lausanne  (EPFL ) in Switzerland have designed an easy method to achieve commercially attractive carbon-capturing with metal-organic frameworksMetal-organic frameworks (MOFs) are versatile compounds hosting nano-sized pores in their crystal structure. Because of their nanopores, MOFs are now used in a wide range of applications, including separating petrochemicalsmimicking DNA, and removing heavy metals, fluoride anions, hydrogen, and even gold from waterGas separation in particular is of great interest to a number of industries, such as biogas production, enriching air in metal working, purifying natural gas, and recovering hydrogen from ammonia plants and oil refineries.

The flexible ‘lattice’ structure of metal-organic frameworks soaks up gas molecules that are even larger than its pore window making it difficult to carry out efficient membrane-based separation,” says Kumar Varoon Agrawal, who holds the GAZNAT Chair for Advanced Separations at EPFL Valais Wallis.

Now, scientists from Agrawal’s lab have greatly improved the gas separation by making the MOF lattice structure rigid. They did this by using a novel “post-synthetic rapid heat treatment” method, which basically involved baking a popular MOF called ZIF-8 (zeolitic imidazolate framework 8) at 360°C for a few seconds. The method drastically improved ZIF-8’s gas-separation performance – specifically in ‘carbon capture’, a process that captures carbon dioxide emissions produced from the use of fossil fuels, preventing it from entering the atmosphere. “For the first time, we have achieved commercially attractive dioxide sieving performance a MOF membrane,” says Agrawal.

Source: https://actu.epfl.ch/

Nanorobots Deliver Drugs Directly To Diseased Tissue

Scientists at EPFL and ETH Zurich in Switzerland have developed tiny elastic robots that can change shape depending on their surroundings. Modeled after bacteria and fully biocompatible, these robots optimize their movements so as to get to hard-to-reach areas of the human body. They stand to revolutionize targeted drug delivery.

One day we may be able to ingest tiny robots that deliver drugs directly to diseased tissue, thanks to research being carried out at EPFL and ETH Zurich.

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The robots are modeled after bacteria and fully biocompatible© 2019 EPFL/ ETHZ

The group of scientists – led by Selman Sakar at EPFL and Bradley Nelson at ETH Zurich – drew inspiration from bacteria to design smart, biocompatible microrobots that are highly flexible. Because these devices are able to swim through fluids and modify their shape when needed, they can pass through narrow blood vessels and intricate systems without compromising on speed or maneuverability. They are made of hydrogel nanocomposites that contain magnetic nanoparticles allowing them to be controlled via an electromagnetic field.

In an article appearing in Science Advances, the scientists describe the method they have developed for “programming the robot’s shape so that it can easily travel through fluids that are dense, viscous or moving at rapid speeds. When we think of robots, we generally think of bulky machines equipped with complex systems of electronics, sensors, batteries and actuators. But on a microscopic scale, robots are entirely different.

Fabricating miniaturized robots presents a host of challenges, which the scientists addressed using an origami-based folding method. Their novel locomotion strategy employs embodied intelligence, which is an alternative to the classical computation paradigm that is performed by embedded electronic systems.Our robots have a special composition and structure that allow them to adapt to the characteristics of the fluid they are moving through. For instance, if they encounter a change in viscosity or osmotic concentration, they modify their shape to maintain their speed and maneuverability without losing control of the direction of motion,” says Sakar.

These deformations can be “programmed” in advance so as to maximize performance without the use of cumbersome sensors or actuators. The robots can be either controlled using an electromagnetic field or left to navigate on their own through cavities by utilizing fluid flow. Either way, they will automatically morph into the most efficient shape.

Source: https://actu.epfl.ch/

Paraplegics Walk Again With Electrical Stimulation

Three paraplegics who sustained cervical spinal cord injuries many years ago are now able to walk with the aid of crutches or a walker thanks to new rehabilitation protocols that combine targeted electrical stimulation of the lumbar spinal cord and weight-assisted therapy.

This latest study, called STIMO (STImulation Movement Overground), establishes a new therapeutic framework to improve recovery from spinal cord injury. All patients involved in the study recovered voluntary control of leg muscles that had been paralyzed for many years. Unlike the findings of two independent studies published recently in the United States on a similar concept, neurological function was shown to persist beyond training sessions even when the electrical stimulation was turned off.

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Our findings are based on a deep understanding of the underlying mechanisms which we gained through years of research on animal models. We were thus able to mimic in real time how the brain naturally activates the spinal cord,” says EPFL neuroscientist Grégoire Courtine.

All the patients could walk using body weight support within one week. I knew immediately that we were on the right path,” adds CHUV neurosurgeon Jocelyne Bloch, who surgically placed the implants in the patients.

The exact timing and location of the electrical stimulation are crucial to a patient’s ability to produce an intended movement. It is also this spatiotemporal coincidence that triggers the growth of new nerve connections,” says Courtine.

The STIMO study, led by the Ecole Polytechnique Fédérale de Lausanne (EPFL) and the Lausanne University Hospital (CHUV ) in Switzerland, is published in  Nature and Nature Neuroscience.

Source: https://actu.epfl.ch/

How To Pilot A Drone Using Virtual Reality

Imagine piloting a drone using the movements of your torso only and leaving your head free to look around, much like a bird. The Ecole Polytechnique Fédérale de Lausanne  (EPFL) research, in Switzerland,  has just shown that using your torso to pilot flying machines is indeed more immersive – and more effective – than using the long-established joystick.

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Our aim was to design a control method which would be easy to learn and therefore require less mental focus from the users so that they can focus on more important issues, like search and rescue,” says lead author Jenifer Miehlbradt of EPFL’s Translational Neuroengineering Laboratory led by Bertarelli Foundation Chair Silvestro Micera. “Using your torso really gives you the feeling that you are actually flying. Joysticks, on the other hand, are of simple design but mastering their use to precisely control distant objects can be challenging.

The scientists wanted to observe how people use their bodies to pilot a flying object, in this case a drone, and determine which movements are most intuitive and natural – approaching the pilot problem from a completely new perspective.

They started by monitoring the body movements of 17 individuals thanks to 19 infrared markers placed all over the upper body as well as their muscular activity. Each participant followed the actions of a virtual drone through simulated landscapes that passed-by as viewed through virtual reality goggles.

The results are published in the journal PNAS.

Source: https://actu.epfl.ch/