Posts belonging to Category Universities



AI Improves Heart Disease Diagnosis

Researchers from the University of Oxford are using artificial intelligence (AI) to improve diagnostic accuracy for heart disease. The team hope to roll out the system across the NHS later this year, helping to improve patient outcomes and saving millions is misdiagnoses. The research, led by Prof Paul Leeson and RDM DPhil student Ross Upton (Cardiovascular Clinical Research Facility), took place in the Oxford University Hospitals Foundation Trust and is the basis of spin-out company Ultromics.

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Thousands of people every year have an echocardiogram – a type of heart scan – after visiting hospital suffering with chest pain. Clinicians currently assess these scans by eye, taking into account many features that could indicate whether someone has heart disease and if they are likely to go on to have a heart attack. But even the most well trained cardiologist can misdiagnose patients. Currently, 1 in 5 scans are misdiagnosed each year – the equivalent to 12,000 patients. This means that people are either not being treated to prevent a heart attack, or they are undergoing unnecessary operations to stave off a heart attack they won’t have.

The new system uses machine learning – a form of artificial intelligence – to tap into the rich information provided in an echocardiogram. Using the new system, AI can detect 80,000 subtle changes inviable to the naked eye, improving the accuracy of diagnosis to 90%. The machine learning system was trained using scans from previous patients, alongside data about whether they went on to have a heart attack. The team hope that the improved diagnostic accuracy will not only improve patient care and outcomes, but save the NHS £300million a year in avoidable operations and treatment.  So far the system has been trialled in six cardiology units in the UK. Further implementation of the technology is now being led by Ultromics – a spin-out company co-founded by Ross Upton and Paul Leeson (Cardiovascular Clinical Research Facility). The software will be made available for free throughout the NHS later this year.

Source: https://www.rdm.ox.ac.uk/

Making Fuel Cells for a Fraction of the Cost

It is the third announcement in less than one week for a major improvment in the making of fuel cells.

In the competition between Lithium-Ion batteries (e.g. Tesla cars), and hydrogen fuel cells (see picture of Nexo from Hyundai) that power electric cars, it is difficult to predict which one will be the winner at the end.

Fuel cells have the potential to be a clean and efficient way to run cars, computers, and power stations, but the cost of producing them is limiting their use. That’s because a key component of the most common fuel cells is a catalyst made from the precious metal platinum.

In a paper published in Small, researchers at the University of California, Riverside (UCR), describe the development of an inexpensive, efficient catalyst material for a type of fuel cell called a polymer electrolyte membrane fuel cell (PEMFC), which turns the chemical energy of hydrogen into electricity and is among the most promising fuel cell types to power cars and electronics.

The catalyst developed at UCR is made of porous carbon nanofibers embedded with a compound made from a relatively abundant metal such as cobalt, which is more than 100 times less expensive than platinum. The research was led by David Kisailus, the Winston Chung Endowed Professor in Energy Innovation in UCR’s Marlan and Rosemary Bourns College of Engineering.

Fuel cells, which are already being used by some carmakers, offer advantages over conventional combustion technologies, including higher efficiency, quieter operation and lower emissions. Hydrogen fuel cells emit only water.

Like batteries, fuel cells are electrochemical devices that comprise a positive and negative electrode sandwiching an electrolyte. When a hydrogen fuel is injected onto the anode, a catalyst separates the hydrogen molecules into positively charged particles called protons and negatively charged particles called electrons. The electrons are directed through an external circuit, where they do useful work, such as powering an electric motor, before rejoining the positively charged hydrogen ions and oxygen to form water.

A critical barrier to fuel cell adoption is the cost of platinum, making the development of alternative catalyst materials a key driver for their mass implementation.

Using a technique called electrospinning, the UCR researchers made paper-thin sheets of carbon nanofibers that contained metal ions — either cobalt, iron or nickel. Kisailus and his team, collaborating with scientists at Stanford University, determined that the new materials performed as good as the industry standard platinum-carbon systems, but at a fraction of the cost. “The key to the high performance of the materials we created is the combination of the chemistry and fiber processing conditions,” Kisailus said

Source: https://ucrtoday.ucr.edu/

Solar-driven Hydrogen Economy

Hydrogen as a fuel source, rather than hydrocarbons like oil and coal, offers many benefits. Burning hydrogen produces harmless water with the potential to eliminate carbon dioxide emissions and their environmental burden. In pursuit of technologies that could lead to a breakthrough in achieving a hydrogen economy, a key issue is making hydrogen cheaply. Using catalysts to split water is the ideal way to generate hydrogen, but doing so usually requires an energy input from other chemicals, electricity, or a portion of sunlight which has high enough energy.

Now researchers at Osaka University have developed a new catalytic system for efficiently splitting water and making hydrogen with energy from normal sunlight. Their study was recently reported in Angewandte Chemie International Edition.

It has not been possible to use visible light for photocatalysis, but our approach of combining nanostructured black phosphorus for water reduction to hydrogen and bismuth vanadate for water oxidation to oxygen lets us make use of a wide range of the solar spectrum to make hydrogen and oxygen with unprecedented efficiency,” lead author Mingshan Zhu says.

Black phosphorus has a flat, two-dimensional structure similar to that of graphene and strongly absorbs light across the whole of the visible spectrum. The researchers combined the black phosphorus with bismuth vanadate, which is a well-known water oxidation catalyst.

In the same way that plants shuttle electrons between different structures in natural photosynthesis to split water and make oxygen, the two components of this new catalyst could rapidly transfer electrons excited by sunlight. The amounts of the two components was also optimized in the catalyst, leading to production of hydrogen and oxygen gases in an ideal 2:1 ratio.

Source: http://resou.osaka-u.ac.jp/

Europe: 17 Organizations United To Produce Li-Ion Batteries

Energy storage has emerged as a central building block of the EU’s objectives in low emission electric transport and replacing electricity generated by fossil fuels with renewables. The realisation that batteries are of such strategic importance has come as a wake-up call, with Europe finding itself lagging in commercialising research in the field, and for now, completely dependent on manufacturers outside the EU for battery supplies. Public and private funders in Europe that have put €555 million into developing new energy storage technologies since 2008 have little to show for it in terms of commercial outputs.

While a number of start-ups, such as France’s NAWA Technology are working on various approaches to increasing energy density and speeding up recharging of electric vehicle batteries, none are in production. As yet, Europe has no factories producing electric vehicle batteries, though LG Chem of South Korea is currently constructing a manufacturing plant in Poland, which is due to open later this year. Another Korean manufacturer, SK Innovation, whose major customer is Mercedes-Benz, has announced it will invest $777 million to build a battery plant with capacity of 7.5 GW/year in Hungary

A European company, Northvolt is planning to build a plant in Skelleftea, northern Sweden, with construction due to start in the second half of 2018. Meanwhile, Frankfurt-based TerraE announced earlier in January that it has formed a consortium of 17 companies and research institutions to handle the planning for two large-scale lithium-ion battery cell manufacturing facilities in Germany. TerraE will build and operate the factories, where customers can have batteries produced to their own specifications.

Source: https://sciencebusiness.net/

Efficient, Low-Cost Catalyst To Produce Hydrogen

A nanostructured composite material developed at UC Santa Cruz has shown impressive performance as a catalyst for the electrochemical splitting of water to produce hydrogen. An efficient, low-cost catalyst is essential for realizing the promise of hydrogen as a clean, environmentally friendly fuel.

Researchers led by Shaowei Chen, professor of chemistry and biochemistry at UC Santa Cruz, have been investigating the use of carbon-based nanostructured materials as catalysts for the reaction that generates hydrogen from water. In one recent study, they obtained good results by incorporating ruthenium ions into a sheet-like nanostructure composed of carbon nitride. Performance was further improved by combining the ruthenium-doped carbon nitride with graphene, a sheet-like form of carbon, to form a layered composite.

The bonding chemistry of ruthenium with nitrogen in these nanostructured materials plays a key role in the high catalytic performance,” Chen said. “We also showed that the stability of the catalyst is very good.”

Currently, the most efficient catalysts for the electrochemical reaction that generates hydrogen from water are based on platinum, which is scarce and expensive. Carbon-based materials have shown promise, but their performance has not come close to that of platinum-based catalysts.

In the new composite material developed by Chen’s lab, the ruthenium ions embedded in the carbon nitride nanosheets change the distribution of electrons in the matrix, creating more active sites for the binding of protons to generate hydrogen. Adding graphene to the structure further enhances the redistribution of electrons.

The new findings were published in ChemSusChem.

Source: https://news.ucsc.edu/

Thin And Highly Insulating Walls Lower Heating Costs

Better thermal insulation means lower heating costs – but this should not be at the expense of exciting architecture. A new type of brick filled with aerogel could make thin and highly insulating walls possible in the future – without any additional insulation layer.

The calculation is simple: the better a building is insulated, the less heat is lost in winter – and the less energy is needed to achieve a comfortable room temperature. No wonder, then, that the Swiss Federal Office of Energy (SFOE) regularly raises the requirements for building insulation.

In order to achieve the same insulation values as a 165 mm thick wall of aerobricks, a wall of perlite bricks must be 263 mm thick – and a wall of non-insulating bricks even more than one meter!

Traditionally, the insulating layers are applied to the finished walls. Increasingly, however, self-insulating bricks are being used – saving both work steps and costs and opening up new architectural possibilities. Insulating bricks offer a workable compromise between mechanical and thermal properties and are also suited for multi-storey buildings. They are already available on the market in numerous models: some have multiple air-filled chambers, others have larger cavities filled with insulating materials such as pearlite, mineral wool or polystyrene. Their thermal conductivity values differ depending on the structure and filling material. In order to reach the insulation values of walls with seperate insulating layers, the insulating bricks are usually considerably thicker than normal bricks.

Empa researchers have now replaced Perlite in insulating bricks with Aerogel: a highly porous solid with very high thermal insulation properties that can withstand temperatures of up to 300°C (see box). It is not a novel material for the researchers: they have already used it to develop a high-performance insulating plaster which, among other things, allows historical buildings to be renovated energetically without affecting their appearance.

Together with his colleagues, Empa researcher Jannis Wernery from the research department «Building Energy Materials and Components» has developed a paste-like mixture of aerogel particles to be used as filler material for the brick. «The material can easily be filled into the cavities and then joins with the clay of the bricks», says Wernery. «The aerogel stays in the bricks – you can work with them as usual.» The «Aerobrick» was born.

Source: https://www.empa.ch/

Memristors Retain Data 10 Years Without Power

The internet of things ( IoT) is coming, that much we know. But still it won’t; not until we have components and chips that can handle the explosion of data that comes with IoT. In 2020, there will already be 50 billion industrial internet sensors in place all around us. A single autonomous device – a smart watch, a cleaning robot, or a driverless car – can produce gigabytes of data each day, whereas an airbus may have over 10 000 sensors in one wing alone.

Two hurdles need to be overcome. First, current transistors in computer chips must be miniaturized to the size of only few nanometres; the problem is they won’t work anymore then. Second, analysing and storing unprecedented amounts of data will require equally huge amounts of energy. Sayani Majumdar, Academy Fellow at Aalto University (Finland), along with her colleagues, is designing technology to tackle both issues.

Majumdar has with her colleagues designed and fabricated the basic building blocks of future components in what are called “neuromorphiccomputers inspired by the human brain. It’s a field of research on which the largest ICT companies in the world and also the EU are investing heavily. Still, no one has yet come up with a nano-scale hardware architecture that could be scaled to industrial manufacture and use.

The probe-station device (the full instrument, left, and a closer view of the device connection, right) which measures the electrical responses of the basic components for computers mimicking the human brain. The tunnel junctions are on a thin film on the substrate plate.

The technology and design of neuromorphic computing is advancing more rapidly than its rival revolution, quantum computing. There is already wide speculation both in academia and company R&D about ways to inscribe heavy computing capabilities in the hardware of smart phones, tablets and laptops. The key is to achieve the extreme energy-efficiency of a biological brain and mimic the way neural networks process information through electric impulses,” explains Majumdar.

In their recent article in Advanced Functional Materials, Majumdar and her team show how they have fabricated a new breed of “ferroelectric tunnel junctions”, that is, few-nanometre-thick ferroelectric thin films sandwiched between two electrodes. They have abilities beyond existing technologies and bode well for energy-efficient and stable neuromorphic computing.

The junctions work in low voltages of less than five volts and with a variety of electrode materials – including silicon used in chips in most of our electronics. They also can retain data for more than 10 years without power and be manufactured in normal conditions.

Tunnel junctions have up to this point mostly been made of metal oxides and require 700 degree Celsius temperatures and high vacuums to manufacture. Ferroelectric materials also contain lead which makes them – and all our computers – a serious environmental hazard.

Our junctions are made out of organic hydro-carbon materials and they would reduce the amount of toxic heavy metal waste in electronics. We can also make thousands of junctions a day in room temperature without them suffering from the water or oxygen in the air”, explains Majumdar.

What makes ferroelectric thin film components great for neuromorphic computers is their ability to switch between not only binary states – 0 and 1 – but a large number of intermediate states as well. This allows them to ‘memoriseinformation not unlike the brain: to store it for a long time with minute amounts of energy and to retain the information they have once received – even after being switched off and on again.

We are no longer talking of transistors, but ‘memristors’. They are ideal for computation similar to that in biological brains.  Take for example the Mars 2020 Rover about to go chart the composition of another planet. For the Rover to work and process data on its own using only a single solar panel as an energy source, the unsupervised algorithms in it will need to use an artificial brain in the hardware.

What we are striving for now, is to integrate millions of our tunnel junction memristors into a network on a one square centimetre area. We can expect to pack so many in such a small space because we have now achieved a record-high difference in the current between on and off-states in the junctions and that provides functional stability. The memristors could then perform complex tasks like image and pattern recognition and make decisions autonomously,” says Majumdar.

Source: http://www.aalto.fi/

Flat Lens Boost Virtual Reality

Metalensesflat surfaces that use nanostructures to focus light — promise to revolutionize optics by replacing the bulky, curved lenses currently used in optical devices with a simple, flat surface.  But, these metalenses have remained limited in the spectrum of light they can focus well Now a team of researchers at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) has developed the first single lens that can focus the entire visible spectrum of light — including white light — in the same spot and in high resolution. This has only ever been achieved in conventional lenses by stacking multiple lenses.

Focusing the entire visible spectrum and white light – combination of all the colors of the spectrum — is so challenging because each wavelength moves through materials at different speeds. Red wavelengths, for example, will move through glass faster than the blue, so the two colors will reach the same location at different times resulting in different foci. This creates image distortions known as chromatic aberrations.

Cameras and optical instruments use multiple curved lenses of different thicknesses and materials to correct these aberrations, which, of course, adds to the bulk of the device.

Metalenses have advantages over traditional lenses,” says Federico Capasso, Professor of Applied Physics at SEAS and senior author of the research. “Metalenses are thin, easy to fabricate and cost effective. This breakthrough extends those advantages across the whole visible range of light. This is the next big step. Using our achromatic lens, we are able to perform high quality, white light imaging. This brings us one step closer to the goal of incorporating them into common optical devices such as cameras“.

The research is published in Nature Nanotechnology.

Source: https://www.seas.harvard.edu/

Fabric Made Of Nanofibers With Embedded OLED

In South Korea, Professor Kyung Cheol Choi from the School of Electrical Engineering (KAIST)  and his team succeeded in fabricating highly efficient Organic Light-Emitting Diodes (OLEDs) on an ultra-thin fiber. The team expects the technology, which produces high-efficiency, long-lasting OLEDs, can be widely utilized in wearable displays. Existing fiber-based wearable displays’ OLEDs show much lower performance compared to those fabricated on planar substrates. This low performance caused a limitation for applying it to actual wearable displays.

In order to solve this problem, the team designed a structure of OLEDs compatible to fiber and used a dip-coating method in a three-dimensional structure of fibers. Through this method, the team successfully developed efficient OLEDs that are designed to last a lifetime and are still equivalent to those on planar substrates.
The team identified that solution process planar OLEDs can be applied to fibers without any reduction in performance through the technology. This fiber OLEDs exhibited luminance and current efficiency values of over 10,000 cd/m^2(candela/square meter) and 11 cd/A (candela/ampere).
The team also verified that the fiber OLEDs withstood tensile strains of up to 4.3% while retaining more than 90% of their current efficiency. In addition, they could be woven into textiles and knitted clothes without causing any problems.Moreover, the technology allows for fabricating OLEDs on fibers with diameters ranging from 300㎛ down to 90㎛, thinner than a human hair, which attests to the scalability of the proposed fabrication scheme.
Noting that every process is carried out at a low temperature (~105℃), fibers vulnerable to high temperatures can also employ this fabrication scheme.
Professor Choi said, “Existing fiber-based wearable displays had limitations for applicability due to their low performance. However, this technology can fabricate OLEDs with high performance on fibers. This simple, low-cost process opens a way to commercialize fiber-based wearable displays.”
Source: http://www.kaist.edu/

New Robust Oilseed Crop Resists Drought

University of Copenhagen (Denmark) and the global player Bayer CropScience have successfully developed a new oilseed crop that is much more resistant to heat, drought and diseases than oilseed rape. The breakthrough is big and it will feature as cover story of the April issue of Nature Biotechnology.

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Oilseed rape does not grow very well in warm and dry areas. We are very happy that we have succeeded in using a groundbreaking technology on a mustard plant, which is a close relative to rape. The result is an oilseed crop with improved agronomic traits that is tolerant to global warming. The new crop will enable cultivation in areas that today is not suitable for oilseed crops, such as the Western part of Canada, parts of Eastern Europe, Australia and India”, explains Professor Barbara Ann Halkier, Head of DynaMo Center of Excellence, University of Copenhagen, is one of the scientists who has worked on developing a new oilseed crop with better properties.

The mustard plant is similar to oilseed rape in many ways. It looks like a rape plant and its oil has the same attractive features with high content of mono– and polyunsaturated fatty acids e.g. omega-3 and -6 plus antioxidants and vitamins. However, it is also a lot more robust when grown under arid conditions and upon exposure to diseases. Mustard is therefore an obvious candidate to replace oilseed rape.

Until now it has been an undefeatable challenge that mustard seeds are full of the bitter defense compounds that give mustard its characteristic flavor. Consequently, the protein-rich seed meal that remains after the oil is pressed out of the seeds is useless as animal feed,” adds Barbara Ann Halkier.

In close collaboration with Bayer CropScience – one of the major global players within plant biotechnology and breeding – she and other scientists from the DynaMo Center have found an original solution to this problem.

Source: http://news.ku.dk/

Alcohol Damages DNA In Stem Cells

Scientists have shown how alcohol damages DNA in stem cells, which may help to explain how drinking alcohol is linked to an increased risk of cancer, according to research led by scientists from the MRC Laboratory of Molecular Biology (UK)  and part-funded by Cancer Research UK. Much previous research looking at the precise ways in which alcohol causes cancer has been done in cell cultures. But in this study, published in Nature, researchers used mice to show how alcohol exposure leads to permanent genetic damage.

The scientists gave diluted alcohol, chemically known as ethanol, to mice. They then used chromosome analysis and DNA sequencing to examine the genetic damage caused by acetaldehyde, a harmful chemical produced when the body processes alcohol. They found that acetaldehyde can break and damage DNA within blood stem cells leading to rearranged chromosomes and permanently altering the DNA sequences within these cells. It is important to understand how the DNA blueprint within stem cells is damaged, because when healthy stem cells become faulty they can give rise to cancer.

Some cancers develop due to DNA damage in stem cells. While some damage occurs by chance, our findings suggest that drinking alcohol can increase the risk of this damage,” said Professor Ketan Patelopens in new window, lead author of the study and scientist, part-funded by Cancer Research UK, at the MRC Laboratory of Molecular Biology.

The study also examined how the body tries to protect itself against damage caused by alcohol. The first line of defence is a family of enzymes called aldehyde dehydrogenases (ALDH). These enzymes break down harmful acetaldehyde into acetate, which our cells can use as a source of energy.

Worldwide, millions of people, particularly those from South East Asia, either lack these enzymes or carry faulty versions of them. So, when they drink, acetaldehyde builds up which causes a flushed complexion, and also leads to them feeling unwell.

In the study, when mice lacking the critical ALDH enzyme ALDH2 – were given alcohol, it resulted in four times as much DNA damage in their cells compared to mice with the fully functioning ALDH2 enzyme.

Source: https://www.mrc.ac.uk/

Nano-based Chip Detects Explosives

Technical University of Denmark (DTU) is ready with a prototype for a chemical “sniffer system” for the detection of criminal substances like narcotics and explosivesDogs have an eminent sense of smell. Their snouts use a specific sniffing technique which almost grabs hold of scents. Elephants’ snouts are even better than those of dogs, but obviously these are attached to elephants which are difficult to carry around. Consequently, today dogs are employed to track narcotics, money and explosives. Sometimes dogs are able to sense explosives in very small doses, however, they are not always 100 percent reliable as they are also sensitive to changes in their surroundings. A technological solution is therefore to be preferred in the tracking of stocks of narcotics or explosive materials.

Researchers at DTU have developed the prototype of a chip able to sniff molecular structures from a number of known substances. A special camera visualises the results from the chip (with 24 megapixels per 15 second) and newly developed software interprets these images according to changes in colour (i.e. the difference between two pictures), caused by the impact of the scents in the air.

We have conducted experiments by sucking air from smaller containers like e.g. handbags or pieces of luggage and from large industrial sized containers typically used for smuggling. In both cases, we arrived at promising results”, says Mogens Havsteen Jakobsen, Senior Researcher at DTU Nanotech.

By using the so-called colorimetric sensing technique, the artificial nose is able to detect different substances like explosives, narcotics, the ripeness of cheese, rotten meat and fish, the quality of wine and coffee or bad indoor climate of a room.

The project has specifically targeted explosives which are a growing safety risk in our society. The Chemical Division of the Danish Emergency Management Agency has been an important collaborator because they are authorised to produce and handle explosives. “We have test laboratories which have been made available during the course of the project”, says Jesper Mogensen, civil engineer and analysis chemist at the Chemical Division and therefore used to handling explosives.

There will be some evident advantages in using a technology such as CRIM-TRACK, compared to the instruments available today,” Jesper Mogensen says. “Firstly, the preparation time is short in that what you largely need to do is switch on the tracker and use it. This is valuable time saved. Secondly and perhaps the most important advantage is the fact that the EOD (the Explosive Ordnance Disposal) does not need to collect a sample. Today when we are called to a ransacking if e.g. a kilo of white powder has been found and we have to analyse its chemistry by way of GC-MS (i.e. gas chromatography-mass spectrometry), a sample of the substance must be collected on a fibre. In other words, it is necessary to collect physically a sample with all the risks this entails. With DTU’s sniffer system, it is possible to collect samples in the air. It sniffs for the drug much like a dog and indicates whether there are any explosives or not. This will increase the safety of our EOD”.

Source: http://www.nanotech.dtu.dk/