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Archive for the ‘nanotechnology’ category: Page 217

May 10, 2019

Discrete energy levels without confinement – a new quantum trick

Posted by in categories: nanotechnology, particle physics, quantum physics

Nanostructures can be designed such a way that the quantum confinement allows only certain electron energy levels. Researchers from IMDEA Nanociencia, UAM and ICMM-CSIC have, for the first time, observed a discrete pattern of electron energies in an unconfined system, which could lead to new ways of modifying the surface properties of materials.

A research group from IMDEA Nanoscience and Universidad Autónoma de Madrid has found for the first time experimental evidence that one-dimensional lattices with nanoscale periodicity can interact with the electrons from a bidimensional gas by spatially separating their different wavelengths by means of a physical phenomenon known as Bragg diffraction. This phenomenon is well-known for wave propagation in general and is responsible for the iridescent color observed upon illumination of a CD surface. Due to the wave-particle duality proposed by De Broglie in 1924, electrons also present a wave-like behavior and, thus, diffraction phenomena. Actually, the observation that low-energy free electrons undergo diffraction processes upon interaction with well-ordered atomic lattices on solid surfaces was the first experimental confirmation of the wave-particle duality.

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May 10, 2019

28 years old and closer than ever to the solving of the mistery of the Majorana particles

Posted by in categories: computing, nanotechnology, particle physics, quantum physics

Gazibegović, Ph.D. candidate in the group of prof. Erik Bakkers at the department of Applied Physics, developed a device made of ultrathin networks of nanowires in the shape of “hashtags.” This device allows pairs of Majorana particles to exchange position and keep track of the changes occurred, in a phenomenon known as “braiding.” This event is considered as a striking proof of the existence of Majorana particles, and it represents a crucial step towards their use as building blocks for the development of quantum computers. With two Nature publications in her pocket, Gazibegović is ready to defend her Ph.D. thesis on May 10.

In 1937, the Italian theoretical physicist Ettore Majorana hypothesized the existence of a unique particle that is its own antiparticle. This particle, also referred to as a “Majorana fermion,” can also exist as a “quasiparticle,” a collective phenomenon that behaves like an individual particle, as in waves forming on the water. The water itself stays in the same place, but the wave can “travel” on the surface, as if it were a single particle in movement. For many years, physicists have been trying to find the Majorana particle without success. Yet, in the last decade, scientists from Eindhoven University of Technology have taken great leap forwards in proving the existence of Majorana particles, also thanks to the research of Gazibegović and her collaborations with the University of Delft, Philips Research and the University of California – Santa Barbara.

Continue reading “28 years old and closer than ever to the solving of the mistery of the Majorana particles” »

May 9, 2019

The power of randomization: Magnetic skyrmions for novel computer technology

Posted by in categories: computing, entertainment, nanotechnology

Researchers at Johannes Gutenberg University Mainz (JGU) have succeeded in developing a key constituent of a novel unconventional computing concept. This constituent employs the same magnetic structures that are being researched in connection with storing electronic data on shift registers known as racetracks. In this, researchers investigate so-called skyrmions, which are magnetic vortex-like structures, as potential bit units for data storage. However, the recently announced new approach has a particular relevance to probabilistic computing. This is an alternative concept for electronic data processing where information is transferred in the form of probabilities rather than in the conventional binary form of 1 and 0. The number 2/3, for instance, could be expressed as a long sequence of 1 and 0 digits, with 2/3 being ones and 1/3 being zeros. The key element lacking in this approach was a functioning bit reshuffler, i.e., a device that randomly rearranges a sequence of digits without changing the total number of 1s and 0s in the sequence. That is exactly what the skyrmions are intended to achieve. The results of this research have been published in the journal Nature Nanotechnology.

The researchers used thin magnetic metallic films for their investigations. These were examined in Mainz under a special microscope that made the magnetic alignments in the metallic films visible. The films have the special characteristic of being magnetized in vertical alignment to the film plane, which makes stabilization of the magnetic skyrmions possible in the first place. Skyrmions can basically be imagined as small magnetic vortices, similar to hair whorls. These structures exhibit a so-called topological stabilization that protects them from collapsing too easily – as a hair whorl resists being easily straightened. It is precisely this characteristic that makes skyrmions very promising when it comes to use in technical applications such as, in this particular case, information storage. The advantage is that the increased stability reduces the probability of unintentional data loss and ensures the overall quantity of bits is maintained.

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May 8, 2019

Quercetin conjugated with superparamagnetic iron oxide nanoparticles improves learning and memory better than free quercetin via interacting with proteins involved in LTP

Posted by in categories: biotech/medical, nanotechnology, neuroscience

Biomedical application of quercetin (QT) as an effective flavonoid has limitations due to its low bioavailability. Superparamagnetic iron oxide nanoparticle (SPION) is a novel drug delivery system that enhances the bioavailability of quercetin. The effect of short time usage of quercetin on learning and memory function and its signaling pathways in the healthy rat is not well understood. The aim of this study was to investigate the effect of free quercetin and in conjugation with SPION on learning and memory in healthy rats and to find quercetin target proteins involved in learning and memory using Morris water maze (MWM) and computational methods respectively. Results of MWM show an improvement in learning and memory of rats treated with either quercetin or QT-SPION. Better learning and memory functions using QT-SPION reveal increased bioavailability of quercetin. Comparative molecular docking studies show the better binding affinity of quercetin to RSK2, MSK1, CytC, Cdc42, Apaf1, FADD, CRK proteins. Quercetin in comparison to specific inhibitors of each protein also demonstrates a better QT binding affinity. This suggests that quercetin binds to proteins leading to prevent neural cell apoptosis and improves learning and memory. Therefore, SPIONs could increase the bioavailability of quercetin and by this way improve learning and memory.

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May 8, 2019

Researchers create ‘impossible’ nano-sized protein cages with the help of gold

Posted by in categories: biotech/medical, genetics, nanotechnology

Researchers from an international collaboration have succeeded in creating a “protein cage”—a nanoscale structure that could be used to deliver drugs to specific places of the body, and which can be readily assembled and disassembled, but also withstands boiling and other extreme conditions. They did this by exploring geometries not found in nature reminiscent of “paradoxical geometries” found in Islamic art.

Role-playing gamers—at least those who played before the digital age—are aware that there are restrictions governing the shape of dice; try to make a six-sided die by replacing the square faces with triangles, and you will be left with something horribly distorted and certainly not fair. This is because there are strict geometrical rules governing the assembly of these so-called isohedra. In nature, isohedral structures are found at the nano level. Usually made from many and having a hollow interior, these protein cages carry out many important tasks. The most famous examples are viruses that use protein cages as a carrier of viral genetic material into host cells.

Synthetic biologists, for their part, are interested in making artificial protein cages in the hope of imparting them with useful and novel properties. There are two challenges to achieving this goal. The first is the geometry problem—some candidate proteins may have great potential utility, but are automatically ruled out because they have the wrong shape to assemble into cages. The second problem is complexity—most are mediated via complex networks of weak chemical bonds that are very difficult to engineer from scratch.

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May 7, 2019

Bacterial toxin research could improve pesticides and help treat cancer

Posted by in categories: biotech/medical, nanotechnology

Research into an intricate toxin delivery system found in bacteria could overcome the problem of pesticide resistance in insects, and might even lead to new cancer treatments.

An international team led by Dr. Michael Landsberg at The University of Queensland has revealed the detailed inner workings of the newest member of a family of naturally occurring insecticidal toxins.

“This , known as YenTc, is a highly effective toxin-delivering nanomachine,” Dr. Landsberg said.

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May 7, 2019

Space experiment looks to slow the aging process using nanoparticles

Posted by in categories: life extension, nanotechnology, space travel

The latest SpaceX Dragon cargo mission to the International Space Station (ISS) included an experiment that could help to combat the ravages of time here on Earth. The European experiment will test how ceramic nanoparticles interact with cells to act as an anti-aging supplement that not only holds promise for alleviating the effects of growing old, but also for combatting chronic illness and space-related stresses for astronauts on prolonged space missions.

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May 6, 2019

Filming how our immune system kill bacteria

Posted by in categories: biotech/medical, nanotechnology

To kill bacteria in the blood, our immune system relies on nanomachines that can open deadly holes in their targets. UCL scientists have now filmed these nanomachines in action, discovering a key bottleneck in the process which helps to protect our own cells.

The research, published in Nature Communications, provides us with a better understanding of how the kills bacteria and why our own cells remain intact. This may guide the development of new therapies that harness the immune system against bacterial infections, and strategies that repurpose the immune system to act against other rogue cells in the body.

In earlier research, the scientists imaged the hallmarks of attack in live bacteria, showing that the immune system response results in ‘bullet holes’ spread across the cell envelopes of bacteria. The holes are incredibly small with a diameter of just 10 nanometres.

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May 4, 2019

A novel technique that uses quantum light to measure temperature at the nanoscale

Posted by in categories: biotech/medical, nanotechnology

Being able to measure, and monitor, temperatures and temperature changes at miniscule scales—inside a cell or in micro and nano-electronic components—has the potential to impact many areas of research from disease detection to a major challenge of modern computation and communication technologies, how to measure scalability and performance in electronic components.

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Apr 30, 2019

DNA folds into a smart nanocapsule for drug delivery

Posted by in categories: biotech/medical, nanotechnology

Researchers from University of Jyväskylä and Aalto University in Finland have developed a customized DNA nanostructure that can perform a predefined task in human body-like conditions. To do so, the team built a capsule-like carrier that opens and closes according to the pH level of the surrounding solution. The nanocapsule can be loaded—or packed—with a variety of cargo, closed for delivery and opened again through a subtle pH increase.

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