#Scientists develop atomic force microscopy for imaging nanoscale dynamics of neurons While progress has been made over the past decades in the pursuit to optimize atomic force microscopy (AFM) for imaging living cells,
there were still a number of limitations and technological issues that needed to be addressed before fundamental questions in cell biology could be address in living cells.
In their March publication in Scientific Reports("Long-tip high-speed atomic force microscopy for nanometer scale imaging in live cells),
"Researchers would like to find molecules to reduce or replace ZDDP altogether, because, although it reduces wear,
In this case, it helps break down the ZDDP molecules and also helps them react to form the tribofilm on the surface.
which use photons instead of electrons to transport and manipulate information, offer many advantages compared to traditional electronic links found in today computers.
#Nanospheres cooled with light to explore the limits of quantum physics A team of scientists at UCL led by Peter Barker
The team successfully suspended glass particles 400 nanometres across in a vacuum using an electric field,
"Nanospheres were cooled with light to explore the limits of quantum physics. Image: James Millen et al. Quantum phenomena are strange and unfamiliar.
where the position or energy of a particle exists in two or more states at the same time and entanglement,
where two particles share the same state (and change in tandem with each other) despite not touching.
But quantum phenomena are only observable in the smallest of objects, such as atoms or molecules,
"Tiny objects like atoms behave according to the laws of quantum physics, "says James Millen (UCL Physics
The largest objects that have been made to behave in a quantum manner are large molecules of about 800 atoms.
We are trying to do the same with glass particles made up of billions of atoms,
when atoms stop vibrating. Widely-used technologies, such as laser cooling, that work for atoms won't work for such large objects,
and a related technique called cavity cooling must be used. During cavity cooling, a particle is suspended by a laser light field contained between two mirrors,
which has a very carefully calibrated wavelength. The laser light can hold the particle steady (a phenomenon known as optical tweezing)
and draw motional energy out of it at the same time. However since the laser light can sometimes actually heat the objects up this method has not been shown to work before."
"Our solution was to combine the laser beam that cools the glass particle with an electric field
"The electric field also gently moves the glass particle around inside the laser beam, helping it lose temperature more effectively."
Since the particles currently used in quantum experiments are tiny, they have negligible mass and so barely interact with gravity.
Observing quantum effects in large and heavy objects like these nanoparticles would also shed light on the role of gravity in quantum physics s
two-dimensional particles embedded within a gel, stimulates bone growth through a complex signaling mechanism without the use of proteins known as growth factors,
Nanosilicate particles are embedded in a collagen-based hydrogel, forming a material that helps trigger bone formation within the body.
magnesium and lithium combined in tiny nanosilicate particles that are 100,000 times thinner than a sheet of paper.
Based on our strong preliminary studies, we predict that these highly biofunctional particles have immense potential to be used in biomedical applications
which strongly effects the propagation of light, in the same way that semiconductors control the flow of electrons.
Using this stage inside a state-of-the-art aberration-corrected transmission electron microscope they can take nanoscale-resolution pictures of lithium ions as they are deposited on or dissolve off of an electrode while the battery runs("Observation and Quantification of Nanoscale Processes in Lithium batteries
Methodsmoving beyond the current industry-standard lithium-ion battery has been difficult. In lithium-air and other designs, interactions at the electrode-electrolyte interfaces affect the battery's performance and safety.
and chemical materials are caused by wavelength selective light absorption in organic molecules. Currently, colors on computer and iphone screens come from dye materials pre-placed on the pixels.
A lot of colors you see in nature are due to wavelength selective light absorption in organic molecules which cannot withstand high temperatures,
Ultraviolet light destroys organic dye molecules over time, leading to color change and fading. The new technology may hold promise for many applications such as for jewelry, automotive interior trim, aviation, signage, colored keypads, electronics and wearable displays s
Sabine van Rijt, CPC/ilbd, Helmholtz Zentrum Mnchen) Nanoparticles are extremely small particles that can be modified for a variety of uses in the medical field.
And these wires have the highest energy density of all known drive mechanisms, which enables them to perform powerful movements in restricted spaces,
Now, a team of experimentalists led by the Department of energy's Oak ridge National Laboratory has demonstrated an energy-efficient desalination technology that uses a porous membrane made of strong, slim graphene--a carbon honeycomb one atom thick.
The water molecules are simply too big to fit through graphene's fine mesh. But poke holes in the mesh that are just the right size
and water molecules can penetrate. Salt ions, in contrast, are larger than water molecules and cannot cross the membrane.
The porous membrane allows osmosis, or passage of a fluid through a semipermeable membrane into a solution in which the solvent is concentrated more."
"Graphene to the rescue Graphene is only one-atom thick, yet flexible and strong. Its mechanical and chemical stabilities make it promising in membranes for separations.
The chemical vapor deposited carbon atoms that self-assembled into adjoining hexagons to form a sheet one atom thick.
The membrane allowed rapid transport of water through the membrane and rejected nearly 100 percent of the salt ions, e g.,
, positively charged sodium atoms and negatively charged chloride atoms. To figure out the best pore size for desalination,
allowed for atom-resolution imaging of graphene, which the scientists used to correlate the porosity of the graphene membrane with transport properties.
including irradiation with electrons and ions, but none of them worked. So far, the oxygen plasma approach worked the best,
#New study shows bacteria can use magnetic nanoparticles to create a'natural battery'(Nanowerk News) New research shows bacteria can use tiny magnetic particles to effectively create a'natural battery.'
"the bacteria can load electrons onto and discharge electrons from microscopic particles of magnetite. This discovery holds out the potential of using this mechanism to help clean up environmental pollution,
The flow of electrons is critical to the existence of all life and the fact that magnetite can be considered to be redox active opens up the possibility of bacteria being able to exist
phototrophic iron-oxidizing bacteria removed electrons from the magnetite, thereby discharging it. During the nighttime conditions, the iron-reducing bacteria took over
and were able to dump electrons back onto the magnetite and recharge it for the following cycle.
molecules of silencing RNA (sirnas) specific for FL2. The sirnas act to silence genes. They do so by binding to a gene MESSENGER RNA (mrna),
and study co-leader Adam Friedman, M d.,director of dermatologic research at Einstein and Montefiore, who together had developed nanoparticles that protect molecules such as sirna from being degraded as they ferry the molecules to their intended targets.
#Next important step toward quantum computer with quantum dots Physicists at the Universities of Bonn and Cambridge have succeeded in linking two completely different quantum systems to one another.
The results have now been published in Physical Review Letters("Direct Photonic Coupling of a Semiconductor Quantum dot and a Trapped Ion".
In contrast, charged atoms, called ions, have an excellent memory: They can store quantum information for many minutes.
therefore both of these components, qdots and ions, to work together as a team. Experts speak of a hybrid system,
because it combines two completely different quantum systems with one another. Absentminded qdots qdots are considered the great hopes in the development of quantum computers.
In principle, they are miniaturized extremely electron storage units. qdots can be produced using the same techniques as normal computer chips.
it is only necessary to miniaturize the structures on the chips until they hold just one single electron (in a conventional PC it is 10 to 100 electrons.
The electron stored in a qdot can take on states that are predicted by quantum theory. However, they are very short-lived:
This decay produces a small flash of light: a photon. Photons are wave packets that vibrate in a specific plane the direction of polarization.
The state of the qdots determines the direction of polarization of the photon.""We used the photon to excite an ion,
"explains Prof. Dr. Michael Khl from the Institute of Physics at the University of Bonn."
"Then we stored the direction of polarization of the photon"."Conscientious ions To do so, the researchers connected a thin glass fiber to the qdot.
They transported the photon via the fiber to the ion many meters away. The fiberoptic networks used in telecommunications operate very similarly.
To make the transfer of information as efficient as possible, they had trapped the ion between two mirrors.
The mirrors bounced the photon back and forth like a ping pong ball, until it was absorbed by the ion."
"By shooting it with a laser beam, we were able to read out the ion that was excited in this way,
"explains Prof. Khl.""In the process, we were able to measure the direction of polarization of the previously absorbed photon".
"In a sense then, the state of the qdot can be preserved in the ion theoretically this can be done for many minutes.
This success is an important step on the still long and rocky road to a quantum computer.
In the long term, researchers around the world are hoping for true marvels from this new type of computer:
Certain tasks, such as the factoring of large numbers, should be child's play for such a computer.
In contrast, conventional computers find this a really tough nut to crack. However, a quantum computer displays its talents only for such special tasks:
and more than 500 times faster than phosphorescence-lifetime-based two-photon microscopy (TPM. The results are published March 30 in Nature Methods advanced online publication("High-speed label-free functional photoacoustic microscopy of mouse brain in action".
#A quantum sensor for nanoscale electron transport The word defect doesnt usually have a good connotation--often indicating failure.
In an experiment, recently published in Science("Probing Johnson noise and ballistic transport in normal metals with a single-spin qubit),
Graphic depiction of NV center sensors (red glowing spheres) used to probe electron motion in a conductor.
when a nitrogen atom substitutes for a carbon atom and is adjacent to a vacancy, or missing carbon atom, in the lattice.
In this experiment, physicists harness the sensitivity of these isolated quantum systems to characterize electron motion. A conductive silver sample is deposited onto a diamond substrate that contains NV centers.
At temperatures above absolute zero, the electrons inside of the silver layer (or any conductor) bounce around
Since electrons are charged particles, their motion results in fluctuating magnetic fields, which extend outside of the conductor.
for stronger fluctuations, it will decay much faster from 1 to 0. By detecting different decay times,
which tells them about the electron behavior at a very small length scale. Like any good sensor, the NV centers are almost completely non-invasivetheir read-out with laser light does not disturb the sample they are sensing.
In polycrystalline samples, atoms are arranged not in a regular repeating lattice over long distances, thus electrons travel dont travel very far--roughly 10 nanometers or less--before scattering off an obstacle.
These frequent collisions are the main source of field noise in polycrystalline materials. In contrast, a single crystal is uniform at these length scales
and electrons can travel over 100 times farther. The electron movement, and corresponding magnetic field noise from the single silver crystal is a departure from so-called Ohmic predictions of the polycrystalline case,
and the team was able to explore both of these extremes non-invasively. These results demonstrate that single NV centers can be used to directly study electron behavior inside of a conductive material on the nanometer length scale.
Notably, this technique does not require electrical leads, applied voltages, or even physical contact with the sample of interest,
and charged atoms (ions) play a key role in the temperature sensitivity of both living plant cells and the dry cyberwood.
Pectins are sugar molecules found in plant cell walls that can be cross-linked depending on temperature, to form a gel.
Calcium and magnesium ions are both present in this gel.""As the temperature rises, the links of the pectin break apart,
and the ions can move about more freely, "explains Di Giacomo. As a result, the material conducts electricity better when temperature increases.
In ongoing work, they are now further developing it such that it functions without plant cells, essentially with only pectin and ions.
which would be more efficient than bird wings based on electrical motors due to the higher energy conversion efficiency (60 to 90 percent) of the dielectric elastomer.
Also, since dielectric elastomers feature high energy density (seventy times higher than conventional electromagnetic actuators) and high-energy conversion efficiency (60 to 90 percent), they could be good candidates for making energy-efficient devices,
Phonons typically move in straight lines in nanowires threads barely a few atoms wide. Previous calculations suggested that if parts of a nanowire contained random arrangements of two different types of atoms,
phonons would be stopped in their tracks. In actual alloy nanowires though, atoms of the same element might cluster together to form short sections composed of the same elements.
Now, Zhun-Yong Ong and Gang Zhang of the A*STAR Institute Of high Performance Computing in Singapore have calculated the effects of such short-range order on the behavior of phonons("Enhancement and reduction of one-dimensional
"Their results suggest that heat conduction in a nanowire does not just depend on the relative concentrations of the alloy atoms and the difference in their masses;
it also depends on how the atoms are distributed. Their model simulated an 88-micrometer-long nanowire containing 160,000 atoms of two different elements.
They found that when the nanowire was ordered more containing clusters of the same elements low-frequency phonons struggled to Move in contrast,
The researchers used their model to study the thermal resistance of a nanowire containing an equal mix of silicon and germanium atoms.
Short-range ordering of the atoms allowed high-frequency phonons to travel freely through the wire giving it a relatively low thermal resistance.
In contrast, a random distribution of alloy atoms resulted in a higher resistance over triple that of the ordered case for a 2. 5-micrometer-long wire.
In nature, molecules called aquaporins, discovered in the 1990s, move water from one side of a biological membrane to another,
but the molecules are fragile and bulky. Now, researchers from the A*STAR Institute of Bioengineering and Nanotechnology have synthesized a much smaller molecule,
which behaves like a olecular drinking strawand which may have applications in water purification and elsewhere. For some years, Huaqiang Zeng of the Institute of Bioengineering and Nanotechnology has led a team aiming to produce tubular molecules that could pipe water across membranes.
In 2012 they created molecules that stacked into a helical tube; unfortunately, this tube was not particularly good at holding water in its central tunnel.
Undeterred, Zeng team set out to modify that molecule. Substituting a carboxyphenyl group for a carboxybenzyl group was just
what was needed once again the molecules stacked into a helix, but this time it comfortably held a tringof water molecules. he continuous one-dimensional ater chaintrapped by the molecules is indispensable for mediating water transport across a lipid membrane,
says Zeng. But early experiments attempting to use osmotic pressure to drive water through the trawinto a membrane-bound compartment (vesicle) drew a blank. e repeatedly failed to demonstrate the water-transporting ability of the molecule
when using a sodium chloride concentration gradient, he says. espite my skepticism, we proceeded to investigate
whether a proton gradient could induce water transport. We were surprised very to find that it could.
The system is known the first example of roton gradient inducedwater transport. am not aware of any other man-made
and derivative molecules, may become ext-generation nanofiltration membranes for water purification applications, including seawater desalination and wastewater reclamation.
He says that osmotic agents often have to be at concentrations exceeding 100 millimolar to drive water movement in forward osmosis nanofiltration. f a proton gradient is used as the driving force instead,
growing axons rely on molecules known as guidance cues, which instruct them on which direction to take by repelling
the researchers created a spherical mass of particles, referred to as a nanoparticle carrier. They constructed the outer layer out of cationicor positively chargedsegments of the polymers.
But not only did the particles stay in place, they were also able to bind with the polymeric matrix
and facilitates the formation of dislocation arrays embedded in low energy grain boundaries. Illustration: Institute for Basic Science) By creating the alloy this way, the joints between the fused grains,
but getting anything more complex than a soap molecule to stay there and behave predictably remains a challenge.
and potentially lead to applications in fields like nanomanufacturing and catalysis. We understand how particles work in 3-D,
the particles will bounce off each other and make a nice suspension, meaning you can do work with them.
Even when particles are able to stay at the interface they tend to clump together and form a skin that cant be pulled back apart into its constituent particles.
The teams technique for surmounting this problem hinged on decorating their gold nanoparticles with surfactant, or soap-like, ligands.
and the way they are attached to the central particle allows them to contort themselves so both sides are happy
when the particle is at an interface. This arrangement produces a flying saucer shape, with the ligands stretching out more at the interface than above or below.
These ligand bumpers keep the particles from clumping together. To get a picture of how the particles packed in their 2-D layer
the researchers dripped a particle-containing an oil droplet out of a pipette into water.
Over time, particles attached to the oil-water interface, at which point the researchers could change their packing density by sucking some of the oil back into the pipette.
By measuring the optical properties of the particles when overcrowding pushed some out, they could work backwards to the number of particles on the interface.
From there, they could determine some universal rules that govern the physics of such systems. This is a very beautiful system,
Stebe says. The ability to tune their packing means that we can now take everything we know about the equilibrium thermodynamics in two dimensions
and start to pose questions about particle layers. Do these particles behave like we think they should?
How can we manipulate them in the future e
#PI's New Motion Simulator'Shaker'Hexapod Based on Fast Linear Motors (Nanowerk News) PI (Physik Instrumente) LP, a leading manufacturer of precision motion
As the focused electron beam passed through the object it excited the crescent energetically, causing it to emit photons, a process known as cathodoluminescence.
Both the intensity and the wavelength of the emitted photons depended on which part of the object the electron beam excited,
Atre said. For instance, the gold shell at the base of the object emitted photons of shorter wavelengths than
when the beam passed near the gap at the tips of the crescent. By scanning the beam back and forth over the object,
the engineers created a 2-D image of these optical properties. Each pixel in this image also contained information about the wavelength of emitted photons across visible and near-infrared wavelengths.
This 2-D cathodoluminescence spectral imaging technique pioneered by the AMOLF team, revealed the characteristic ways in
The technique can be used to probe many systems in which light is emitted upon electron excitation."
"This novel material significantly enhanced catalytic activity for the oxygen reduction reaction--the splitting of an O2 molecule into two oxygen ions--that is critical to fuel cells and potentially other electrochemical applications.
The step forward follows research by the Universities of Warwick and Cambridge and the unexpected discovery of a previously unknown arrangement of molecules in plant cell walls.
Professor Paul Dupree of the University of Cambridge (son of Professor Ray Dupree) says"For the first time we have been able to study the arrangement of molecules in woody plant materials.
It is a powerful technique that can provide detailed information on the three-dimensional structure and dynamics of molecules in solution and the solid state e
The findings were published today in the open-access journal Science Advances("Electrically controlling single-spin qubits in a continuous microwave field".
"This is an electron wave in a phosphorus atom, distorted by a local electric field. Unlike conventional computers that store data on transistors and hard drives, quantum computers encode data in the quantum states of microscopic objects called qubits.
& Communication Technology, was first in the world to demonstrate single-atom spin qubits in silicon,
like the spin of a single phosphorus atom in isotopically enriched silicon, can be controlled using electric fields,
Associate professor Morello said the method works by distorting the shape of the electron cloud attached to the atom,
which the electron responds.""Therefore, we can selectively choose which qubit to operate. It's a bit like selecting which radio station we tune to,
Here, the'knob'is applied the voltage to a small electrode placed above the atom.""The findings suggest that it would be possible to locally control individual qubits with electric fields in a large-scale quantum computer using only inexpensive voltage generators, rather than the expensive high-frequency microwave sources.
containing only the silicon-28 isotope.""This isotope is perfectly nonmagnetic and, unlike those in naturally occurring silicon,
does not disturb the quantum bit, "Associate professor Morello said. The purified silicon was provided through collaboration with Professor Kohei Itoh from Keio University in Japan n
Now researchers at Tokyo Institute of technology and the Japan Science and Technology Agency have designed a liquid crystal molecule that produces high-performance organic field effect transistors (FETS) with good temperature resilience and relatively low device
"Hiroaki Iino, Takayuki Usui and Jun-ichi Hanna designed a molecule that would incorporate a number of desirable liquid crystal qualities, in particular the smectic E phase.
They then fabricated organic FETS by spin coating a solution of their material at 110 C before allowing it to cool.
Using atomic force microscopy the researchers identified that at around 120 C in the crystal formed a bilayer crystal phase.
resulting from the phase transition from a monolayer to a bilayer crystal structure in mono-alkylated liquid crystalline molecules may lead to the possibility of designing new materials for the burgeoning field of printed electronics."
Background Small-molecule versus polymer FETS The main issues around organic semiconductor FETS with small molecules are the low thermal durability.
The same bonding that makes the molecules soluble for printing fabrication processes also leaves them prone to low melting points,
Attempts to use polymers with benzene-like delocalised electron bonding alleviated issues around the thermal durability to a certain extent.
The design of the molecule The researchers identified specific characteristics to enrol in the design of their molecule.
They used a fused ring system of molecules with benzene-like delocalised electron bonding so that the material would readily crystallise.
The molecule was designed also to have a single side chain so that crystallisation on cooling would be lower than that on heating.
Just like living organisms, organic electronics use carbon in complex molecules as their key functional component.
They did this by designing a small device based on organic molecules in which the built-in electric field creates a well
and steric properties of various organic molecules, including biologically active compounds such as pharmaceuticals and agrochemicals,
ITBM, Nagoya University) Metal-catalyzed C-H borylation of aromatic rings is considered an efficient way to introduce functional groups to make functional molecules via a boryl moiety.
and materials science for creating benzene-containing functional molecules, I figured that para-selective C-H functionalization would be an extremely useful technique for the late-stage diversification of core structures.
--but at much lower energy absorption efficiency levels,"said Ramahi.""We can also channel the absorbed energy into a load,
"Our research enables significantly higher energy absorption than classical antennas, "Ramahi said.""This results in a significant reduction of the energy harvesting surface footprint.
As Klaas-Jan Tielrooij comments,"the experiment uniquely combined the ultrafast pulse shaping expertise obtained from single molecule ultrafast photonics with the expertise in graphene electronics.
This interaction leads to a rapid creation of an electron distribution with an elevated electron temperature.
and rapidly converted into electron heat. Next, the electron heat is converted into a voltage at the interface of two graphene regions with different doping.
This photo-thermoelectric effect turns out to occur almost instantaneously, thus enabling the ultrafast conversion of absorbed light into electrical signals.
The temperature determination is usually based on the change of the luminescence intensity or decay times.
Bhushan and postdoctoral researcher Philip Brown chose to cover a bumpy surface with a polymer embedded with molecules of surfactant--the stuff that gives cleaning power to soap and detergent.
Such particles could be used to detect oil underground or aid removal in the case of oil spills.
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