"The researchers resorted to the computational approach because of the difficulty of capturing the structure via X-ray crystallography or single-particle transmission electron microscopy, two of the most common imaging methods at the atomic scale.
Virus concentrations ranged from 13 to 2350 particles per cubic meter of air. A dose of 20 norovirus particles is usually enough to cause gastroenteritis.
According to Professor Duchaine this previously unknown mode of norovirus propagation could explain why gastroenteritis outbreaks are so hard to contain:"
#Bringing high-energy particle detection in from the cold Now researchers from Oak ridge National Laboratory in Tennessee think they have a good candidate material.
"From the theoretical study, we have identified the most detrimental defects that hinder the electron transport in thallium sulfide iodide
researchers can use synchrotrons--dedicated facilities where electrons run laps in football-stadium-sized storage rings to produce the desired radiation
Conversely, the CLS is a miniature version of a synchrotron that produces suitable X-rays by colliding laser light with electrons circulating in a desk-sized storage ring.
For the first time, the researchers were able to show that this mechanical system can be used to coherently manipulate an electron spin embedded in the resonator--without external antennas or complex microelectronic structures.
the research team led by Georg H. Endress Professor Patrick Maletinsky described how resonators made from single-crystalline diamonds with individually embedded electrons are suited highly to addressing the spin of these electrons.
In these"nitrogen-vacancy centers,"individual electrons are trapped. Their"spin"or intrinsic angular momentum is examined in this research.
in turn, influences the spin of the electrons, which can indicate two possible directions("up"or"down")when measured.
This means that the spin of the electrons switches from up to down and vice versa in a controlled and rapid rhythm and that the scientists can control the spin status at any time.
"This expansion and contraction of aluminum particles generates great mechanical stress, which can cause electrical contacts to disconnect.
which would be ok if not for the repeated large volume expansion and shrinkage that cause SEI particles to shed.
but yolk-shell particles feature a void between the two--equivalent to where the white of an egg would be.
The aluminum particles they used, which are about 50 nanometers in diameter, naturally have oxidized an layer of alumina (Al2o3)."
a better conductor of electrons and lithium ions when it is very thin. Aluminum powders were placed in sulfuric acid saturated with titanium oxysulfate.
if the particles stay in the acid for a few more hours, the aluminum core continuously shrinks to become a 30-nm-across"yolk,,
The particles are treated then to get the final aluminum-titania (ATO) yolk-shell particles. After being tested through 500 charging-discharging cycles,
and electrons to get in and out. The result is an electrode that gives more than three times the capacity of graphite (1. 2 Ah/g) at a normal charging rate
#Ultra-fast electron camera A new scientific instrument promises to capture some of nature's speediest processes.
It uses a method known as ultrafast electron diffraction (UED) and can reveal motions of electrons
and atomic nuclei within molecules that take place in less than a tenth of a trillionth of a second--information that will benefit groundbreaking research in materials science, chemistry and biology.
The technique complements ultrafast studies with SLAC's X-ray free-electron laser. Similar to X-ray light, highly energetic electrons can take snapshots of the interior of materials as they pass through them.
Yet electrons interact differently with materials and"see"different things. Both methods combined draw a more complete picture that will help researchers better understand
and possibly control important ultrafast processes in complex systems ranging from magnetic data storage devices to chemical reactions.
The superior performance of the new UED system is due to a very stable"electron gun"originally developed for SLAC's X-ray laser Linac Coherent Light source (LCLS), a DOE Office of Science User Facility.
This electron source produces highly energetic electrons, packed into extremely short bunches. It spits out 120 of these bunches every second
generating a powerful electron beam that the researchers use to probe objects on the inside.
But how can scientists actually catch a glimpse of the interior of materials with particles like electrons?
The method works because particles have a second nature: They also behave like waves. When electron waves pass through a sample,
they scatter off the sample's atomic nuclei and electrons. The scattered waves then combine to form a so-called diffraction pattern picked up by a detector.
The whole apparatus works like a high-speed camera, capturing differences in diffraction patterns over time that scientists use to reconstruct the sample's inner structure and how it changes.
Since electron bunches in SLAC's UED instrument are extremely short, they reveal changes that occur in less than 100 quadrillionths of a second, or 100 femtoseconds,
but the repulsive forces between electrons in the electron beam limited the time resolution of previous experiments,
"Electrons behave similarly to X-rays in the way they explore speedy phenomena in nature. Electrons scatter off both electrons and atomic nuclei in materials.
X-rays, on the other hand, interact only with electrons. Therefore, electron and X-ray studies of very fast structural changes complement each other.
The SLAC-led team has begun already to combine both approaches to better understand the link between the magnetic behavior of certain materials
and their structural properties in studies that could help develop next-generation data storage devices. Electrons also provide a path to studies that are very challenging to perform with X-rays."
"Electrons interact with materials much more strongly than X-rays do, "says SLAC's Renkai Li, the paper's lead author."
"We were able to analyze samples such as very thin films whose X-ray signals would be very weak."
"Due to the almost 1, 000-fold shorter wavelength of electrons compared to X-rays, UED can see much finer structural details.
--and will eventually reduce the size of the electron beam from its current 100 microns--the diameter of an average human hair--to below one micron.
"This will generate unforeseen possibilities for ultrafast science with electrons, similar to the great things we saw happening a few years ago at LCLS,
#New research may enhance display, LED lighting technology Recently, quantum dots (QDS)--nano-sized semiconductor particles that produce bright, sharp,
In addition, as an actual needle application, we demonstrated fluorescenctce particle depth injection into the brain in vivo,
Raman spectroscopy and transport measurements on the graphene/boron nitride heterostructures reveals high electron mobilities comparable with those observed in similar assemblies based on exfoliated graphene.
"Even though we're not sending a huge amount of photons, at short time scales, we're sending a lot more energy to that spot than the energy sent by the sun,
which the two quantum logic gates were applied to single photons in both orders. The results of their experiment confirm that it is impossible to determine which gate acted first
From a single measurement on the photon, they probed a specific property of the two quantum gates thereby confirming that the gates were applied in both orders at once.
Scientists unveil new technique for spotting quantum dots to make high performance nanophotonic devices A quantum dot should produce one and only one photon--the smallest constituent of light--each time it is energized,
which will enable control of the photons that the quantum dot generates. However finding the quantum dots--they're just about 10 nanometers across--is no small feat.
and used it to create high-performance single photon sources. Array"This is a first step towards providing accurate location information for the manufacture of high performance quantum dot devices,
Their coordinates in hand, scientists can then tell the computer-controlled electron beam lithography tool to place any structure the application calls for in its proper relation to the quantum dots,
the researchers demonstrated grating-based single photon sources in which they were able to collect 50 per cent of the quantum dot's emitted photons, the theoretical limit for this type of structure.
They also demonstrated that more than 99 per cent of the light produced from their source came out as single photons.
Such high purity is partly due to the fact that the location technique helps the researchers to quickly survey the wafer (10,000 square micrometers at a time) to find regions where the quantum dot density is especially low-only about one per 1
Now, researchers from the University of Bristol in the UK and Nippon Telegraph and Telephone (NTT) in Japan, have pulled off the same feat for light in the quantum world by developing an optical chip that can process photons in an infinite number
This result shows a step change for experiments with photons and what the future looks like for quantum technologies.
Now anybody can run their own experiments with photons, much like they operate any other piece of software on a computer.
The method consists in converting the natural pomegranate juice in small dust particles that can be dissolved in water.
"The study was supported also by X-ray experiments at SSRL and at Argonne National Laboratory's Advanced Photon Source."
#Scientists uncover nuclear process in the brain that may affect disease Every brain cell has a nucleus,
Scientists have shown that the passage of molecules through the nucleus of a star-shaped brain cell, called an astrocyte,
The cell nucleus is a ball of chromosomes wrapped in a protective fatty membrane. In this study, the researchers discovered that treating astrocytes with TGF-beta freed a small piece of the p75ntr protein to bind to nucleoporins,
and out of the nucleus. Their results suggest that binding enhances the flow of certain critical molecules into the nucleus
The scientists used high-resolution microscopes to watch the astrocyte nucleus in action. Nuclear pores that did not have the p75ntr gene were slightly larger than normal.
This allowed transport into the nucleus of a protein called Smad2, which is essential for TGF-beta to exert its effects on astrocytes.
In other experiments, the scientists showed that eliminating p75ntr from astrocytes blocked the transport of Smad2 into the nucleus."Nuclear pores are gatekeepers
so called because they use plasmons--collective excitations of electrons in a conductor--rather than electrons to transfer
electrons that tunnel across the gap can excite plasmons, although inefficiently.""Yang likens the excitation of plasmons in gratings to dropping pebbles in a swimming pool with swimming lanes demarcated by floats."
generating protons and electrons as well as oxygen gas. The photocathode recombines the protons and electrons to form hydrogen gas.
A key part of the JCAP design is the plastic membrane, which keeps the oxygen and hydrogen gases separate.
and electrons to pass through. The new complete solar fuel generation system developed by Lewis and colleagues uses such a 62.5-nanometer-thick Tio2 layer to effectively prevent corrosion
protons, and electrons and is a key to the high efficiency displayed by the device.
and Ministry of Science and Technology of China (2009cb918500) and the National Natural science Foundation of China (21173013,11021463) to L. L. This research used the Advanced Photon Source for protein crystallography data collection
#Scientists'squeeze'light one particle at a time A team of scientists has measured successfully particles of light being squeezed,
In the journal Nature, a team of physicists report that they have demonstrated successfully the squeezing of individual light particles,
or photons, using an artificially constructed atom, known as a semiconductor quantum dot. Thanks to the enhanced optical properties of this system and the technique used to make the measurements,
That meant we were able to reach the necessary conditions to observe this fundamental property of photons
and prove that this odd phenomenon of squeezing really exists at the level of a single photon.
what photons should do.""Like a lot of quantum physics, the principles behind squeezing light involve some mind-boggling concepts.
It begins with the fact that wherever there are light particles, there are also associated electromagnetic fluctuations. This is a sort of static
It looks like there are zero photons present, but actually there is just a tiny bit more than nothing."
This excited the quantum dot and led to the emission of a stream of individual photons.
This states that in any situation in which a particle has linked two properties, only one can be measured
Atature added that the main point of the study was simply to attempt to see this property of single photons,
#Ideal single-photon source developed With the help of a semiconductor quantum dot, physicists have developed a new type of light source that emits single photons.
For the first time, the researchers have managed to create a stream of identical photons. They have reported their findings in the scientific journal Nature Communications together with colleagues from the University of Bochum.
A single-photon source never emits two or more photons at the same time. Single photons are important in the field of quantum information technology where, for example,
they are used in quantum computers. Alongside the brightness and robustness of the light source the indistinguishability of the photons is especially crucial.
In particular, this means that all photons must be the same color. Creating such a source of identical single photons has proven very difficult in the past.
However, quantum dots made of semiconductor materials are offering new hope. A quantum dot is a collection of a few hundred thousand atoms that can form itself into a semiconductor under certain conditions.
Single electrons can be captured in these quantum dots and locked into a very small area. An individual photon is emitted
when an engineered quantum state collapses. Noise in the semiconductor A team of scientists led by Dr. Andreas Kuhlmann and Prof.
Richard J. Warburton from the University of Basel have shown already in past publications that the indistinguishability of the photons is reduced by the fluctuating nuclear spin of the quantum dot atoms.
For the first time ever, the scientists have managed to control the nuclear spin to such an extent that even photons sent out at very large intervals are the same color.
Quantum cryptography and quantum communication are two potential areas of application for single-photon sources.
These technologies could make it possible to perform calculations that are far beyond the capabilities of today's computers.
The study was supported by the QSIT-Quantum Science and Technology National Center of Competence in Research
"Decorating monolayer graphene with a layer of lithium atoms enhances the graphene's electron-phonon coupling to the point where superconductivity can be induced,
"Decorating monolayer graphene with a layer of lithium atoms enhances the graphene's electron-phonon coupling to the point where superconductivity can be stabilized."
"Decorating monolayer graphene with a layer of lithium atoms enhances the graphene's electron-phonon coupling to the point where superconductivity can be induced,
"Decorating monolayer graphene with a layer of lithium atoms enhances the graphene's electron-phonon coupling to the point where superconductivity can be stabilized."
"We're good at generating electrons from light efficiently, but chemical synthesis always limited our systems in the past.
"We're good at generating electrons from light efficiently, but chemical synthesis always limited our systems in the past.
In our current electronic equipment, information is transported via the motion of electrons. In this scheme, the charge of the electron is used to transmit a signal.
In a magnetic insulator, a spin wave is used instead. Spin is a magnetic property of an electron.
A spin wave is caused by a perturbation of the local magnetisation direction in a magnetic material.
Such a perturbation is caused by an electron with an opposite spin, relative to the magnetisation.
An electron can flow through the platinum, but not in the YIG since it is an insulator.
However, if the electron collides on the interface between YIG and platinum this influences the magnetisation at the YIG surface and the electron spin is transferred.
This causes a local magnetisation direction, generating a spin wave in the YIG. Spin wave detection The spin waves that the researchers send into the YIG are detected by the platinum strip on the other side of the YIG.
and transfers its spin to an electron in the platinum. This influences the motion of the electron, resulting in an electric current that the researchers can measure.
The researchers already studied the combination of platinum and YIG in previous research. From this research it was found that
or cooling of the platinum-YIG interface, depending on the relative orientation of the electron spins in the platinum and the magnetisation in the YIG I
#Building the electron superhighway TV screens that roll up. Roofing tiles that double as solar panels. Sun powered cell phone chargers woven into the fabric of backpacks.
But the basic science of how to get electrons to move quickly and easily in these organic materials remains murky.
what they are calling"an electron superhighway"in one of these materials--a low-cost blue dye called phthalocyanine--that promises to allow electrons to flow faster and farther in organic semiconductors Their discovery,
"Roughly speaking, an exciton is displaced a electron bound together with the hole it left behind.
the UVM team was able to observe nanoscale defects and boundaries in the crystal grains in the thin films of phthalocyanine--roadblocks in the electron highway."
"We have discovered that we have hills that electrons have to go over and potholes that they need to avoid,
"these stacked molecules--this dish rack--is the electron superhighway.""Though excitons are charged neutrally --and can't be pushed by voltage like the electrons flowing in a light bulb--they can, in a sense, bounce from one of these tightly stacked molecules to the next.
This allows organic thin films to carry energy along this molecular highway with relative ease,
Wave-particle dualism with large molecules The virtual laboratories provide an insight into the fundamental understanding and into the applications of quantum mechanics with macromolecules and nanoparticles.
In recent years, the real-life versions of the experiments verified the wave-particle dualism with the most complex molecules to date.
#Tiny silica particles could be used to repair damaged teeth, research shows Researchers at the University of Birmingham have shown how the development of coated silica nanoparticles could be used in restorative treatment of sensitive teeth
The study, published in the Journal of Dentistry, shows how sub-micron silica particles can be prepared to deliver important compounds into damaged teeth through tubules in the dentine.
The tiny particles can be bound to compounds ranging from calcium tooth building materials to antimicrobials that prevent infection.
with the particles acting like seeds for further growth that would close the tubules. Previous attempts have used compounds of calcium fluoride, combinations of carbonate-hydroxypatite nanocrystals and bioactive glass,
However, the Birmingham team turned to sub-micron silica particles that had been prepared with a surface coating to reduce the chance of aggregation.
When observed using high definition SEM (Scanning Electron Microsopy the researchers saw promising signs that suggested that the aggregation obstacle had been overcome.
"These silica particles are available in a range of sizes, from nanometre to sub-micron,
""We tested a number of different options to see which would allow for the highest level particle penetration into the tubules,
and then see how effective the particles are blocking the communication with the inside of the tooth.
Deleon and her UD team have identified particles in the secretions from the fallopian tube that help the sperm get ready for its all-important drive into the end zone.
supplies beams from exotic elementary particles called muons, which can be used to study nanomagnetic properties. The project took place in collaboration with a research group headed by Stephen Lee from the University of St andrews, Scotland n
which a beam of electrons smaller than the size of a hydrogen atom is scanned over a sample
and measures how many electrons interact with the atoms at each scan position. The method reveals the atomic structure of materials
because different arrangements of atoms cause electrons to interact in different ways. However, scanning transmission electron microscopes only produce two-dimensional images.
The downside of this technique is repeated that the electron beam radiation can progressively damage the sample.
thanks to the electron beam energy being kept below the radiation damage threshold of tungsten. Miao and his team showed that the atoms in the tip of the tungsten sample were arranged in nine layers, the sixth
and cools it in a way that allows it to convert more photons into electricity. The work by Shanhui Fan, a professor of electrical engineering at Stanford, research associate Aaswath P. Raman and doctoral candidate Linxiao Zhu is described in the current issue of Proceedings of the National Academy
the less efficient they become at converting the photons in light into useful electricity. The Stanford solution is based on a thin,
"We call this a smart particle, "said James Swartz, the professor of chemical engineering and of bioengineering at Stanford who led the study."
"Using the smart particle for immunotherapy would involve tagging its outer surface with molecules designed to teach the body's disease-fighting cells to recognize
It will require much more effort to accomplish the second goal--packing tiny quantities of medicines into the smart particles,
delivering the particles to and into diseased cells, and engineering them to release their payloads.'
"But I believe we can use this smart particle to deliver cancer-fighting immunotherapies that will have minimal side effects."
"Dr. Swartz and colleagues have done a remarkable job of stabilizing viruslike particles and re-engineering their surface."
The new paper describes how the Stanford team designed a viruslike particle that is only a delivery vehicle with no infectious payload.
Swartz said the next step is to attach cancer tags to the outside of this smart particle,
"or transferred quantum information carried in light particles over 100 kilometers (km) of optical fiber, four times farther than the previous record.
The achievement was made possible by advanced single-photon detectors designed and made at NIST.""Only about 1 percent of photons make it all the way through 100 km of fiber,
"NIST's Marty Stevens says.""We never could have done this experiment without these new detectors,
when in a sequence of time slots a single photon arrives. The teleportation method is novel in that four of NIST's photon detectors were positioned to filter out specific quantum states.
The detectors rely on superconducting nanowires made of molybdenum silicide. They can record more than 80 percent of arriving photons,
revealing whether they are in the same or different time slots each just 1 nanosecond long.
which harness the science of the very small--the strange behaviour of subatomic particles--to solve computing challenges that are beyond the reach of even today's fastest supercomputers.
"We've morphed those silicon transistors into quantum bits by ensuring that each has only one electron associated with it.
We then store the binary code of 0 or 1 on the'spin'of the electron,
which is associated with the electron's tiny magnetic field, "he added. Dzurak noted that that the team had patented recently a design for a full-scale quantum computer chip that would allow for millions of our qubits,
'Electrons have a spin, and thus they interact with magnetic structures, 'says Prof. Stefan Heinze from the University of Kiel.
When the electrons are travelling through a magnetic whirl, they feel the canting between the atomic magnets,
as the scientists surrounding DESY's Franz Kärtner from the Center For free-Electron Laser Science (CFEL) point out.
The physicists fired fast electrons into the miniature accelerator module using a type of electron gun provided by the group of CFEL Professor Dwayne Miller, Director at the Max Planck Institute for the Structure and Dynamics
The electrons were accelerated then further by the terahertz radiation fed into the module. This first prototype of a terahertz accelerator was able to increase the energy of the particles by seven kiloelectronvolts (kev."
"This is not a particularly large acceleration, but the experiment demonstrates that the principle does work in practice,
and as a means of building compact X-ray lasers and electron sources for use in materials research,
experimental free-electron X-ray laser (XFEL) on a laboratory scale using terahertz technology. This project is supported by a Synergy Grant of the European Research Council.
So-called free-electron lasers (FELS) generate flashes of laser light by sending high-speed electrons from a particle accelerator down an undulating path,
"Hasan's method, developed at the University's Nanoscience Centre, works by suspending tiny particles of graphene in a'carrier'solvent mixture,
Light goes infinitely fast with new on-chip material Electrons are so 20th century. In the 21st century, photonic devices,
or waveguide to emit photons which are always in phase with one another, "said Philip Munoz,
and infinitely long, enabling even distant particles to be entangled.""""This on-chip metamaterial opens the door to exploring the physics of zero index
a change in electrical resistance, also known as magnetoresistance, occurs as the electrons are deflected. The discovery of magnetoresistance paved the way for magnetic field sensors used in hard disk drives and other devices,
The particles, described in Nature Communications, are enhanced an version of a naturally occurring, weakly magnetic protein called ferritin."
This eliminates the need to tag cells with synthetic particles and allows the particles to sense other molecules inside cells.
The paper's lead author is former MIT graduate student Yuri Matsumoto. Other authors are graduate student Ritchie Chen and Polina Anikeeva, an assistant professor of materials science and engineering.
Magnetic pull Previous research has yielded synthetic magnetic particles for imaging or tracking cells, but it can be difficult to deliver these particles into the target cells.
In the new study Jasanoff and colleagues set out to create magnetic particles that are encoded genetically.
With this approach, the researchers deliver a gene for a magnetic protein into the target cells,
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