and are composed of 10-20 atoms that are segregated to the surface. The unique environment around the Pd-islands give rise to special effects that all together turn the islands into highly efficient catalytic hot-spots for oxygen reduction.
Although it was known that developing egg cells go through a bottleneck period that decreases the number of mtdna molecules scientists didn't know how small
--if there is a severe decrease in mitochondrial molecules during the egg-cell development--then the genetic makeup of the child might differ dramatically from that of the mother.
For many mitochondrial diseases 70 to 80 percent of molecules need to have the disease-causing variant for the disease to manifest itself.
But for others only 10 percent of the mtdna molecules with the variant are needed to cause disease.
Knowing the size of the bottleneck allows us to predict within a range the percentage of disease-carrying molecules that will be passed on to the child.
The key to the advance is a new invention called the Suntag a series of molecular hooks for hanging multiple copies of biologically active molecules onto a single protein scaffold used to target genes or other molecules.
Compared to molecules assembled without these hooks those incorporating the Suntag can greatly amplify biological activity.
The Vale team used the Suntag to greatly amplify the light-emitting signal from the green fluorescent protein commonly used by researchers to label molecules within cells.
Viewed through a microscope the signal that can be obtained with the Suntag is so strong it can be used to track a single molecule within the molecular motors that Vale studies.
which researchers can insert any specific RNA partner molecule. The selected RNA serves as an adaptor that determines the target anywhere within the genome.
The Weissman team led experiments demonstrating that CRISPR molecules incorporating the Suntag can be used to precisely control gene expression of many genes within the genome.
Searching for a safe way to target the NF-kb pathway they screened over 20000 molecules
This is the first time that anyone has imaged directly single dopant atoms moving around inside a material said Rohan Mishra of Vanderbilt University who is also a visiting scientist in ORNL's Materials science and Technology Division.
Semiconductors which form the basis of modern electronics are doped by adding a small number of impure atoms to tune their properties for specific applications.
The study of the dopant atoms and how they move or diffuse inside a host lattice is a fundamental issue in materials research.
Traditionally diffusion of atoms has been studied through indirect macroscopic methods or through theoretical calculations. Diffusion of single atoms has previously been observed directly only on the surface of materials.
The experiment also allowed the researchers to test a surprising prediction: Theory-based calculations for dopant motion in aluminum nitride predicted faster diffusion for cerium atoms than for manganese atoms.
This prediction is surprising as cerium atoms are larger than manganese atoms. It's completely counterintuitive that a bigger heavier atom would move faster than a smaller lighter atom said the Material Science and Technology Division's Andrew Lupini a coauthor of the paper.
In the study the researchers used a scanning transmission electron microscope to observe the diffusion processes of cerium and manganese dopant atoms.
The images they captured showed that the larger cerium atoms readily diffused through the material
while the smaller manganese atoms remained fixed in place. The team's work could be applied directly in basic material design
and technologies such as energy saving LED LIGHTS where dopants can affect color and atom movement can determine the failure modes.
Diffusion governs how dopants get inside a material and how they move said Lupini. Our study gives a strategy for choosing
which dopants will lead to a longer device lifetime. The study was funded by the DOE Office of Science the Australian Research Council Vanderbilt University and the Japan Society for the Promotion of Science Postdoctoral Fellowship for research abroad.
and self protection in Strain 115 are clustered conveniently on a compact DNA molecule a plasmid that replicates itself as a small circle within the cells of Strain 115 says Griffitts.
because the parallel alignment of adjacent electron spins in the iron atoms generates a strong internal magnetic field.
Almost all known superconductors on the other hand form pairs of anti-aligned electrons and exclude magnetic field lines from their interiors.
At somewhat lower temperatures the iron atoms in the (Life) OH layer become ferromagnetic but superconductivity persists nevertheless.
#Body position in breast cancer radiation treatment matters, experts say A new treatment board which allows patients to lie on their stomach in the prone position during radiation treatment is proving more effective for breast cancer patients
while the breast tissue falls away from the chest wall allowing the radiation to target the cancer.
While that approach can be effective there is a slight chance of radiation damage to healthy heart and lung tissue.
and create a more uniform shape that we can distribute the dose of radiation through evenly said White director of Breast Radiation Oncology at the Stefanie Spielman Comprehensive Breast Center.
With this board we can keep the radiation in front of the ribs so we don't need even to go into the thoracic cavity and skim the lung and heart.
Additionally the modified board is able to extend off the treatment table giving the radiation beam space to make a full rotation around the patient.
So having that history of heart disease my main concern was the radiation affecting my heart said Doran It made
#Smart lithium-ion battery warns of fire hazard Stanford university scientists have developed a smart lithium-ion battery that gives ample warning before it overheats
The new technology is designed for conventional lithium-ion batteries now used in billions of cellphones laptops and other electronic devices as well as a growing number of cars and airplanes.
Lowering the oddsa series of well-publicized incidents in recent years has raised concern over the safety of lithium-ion batteries.
In 2006 the Sony Corporation recalled millions of lithium-ion batteries after reports of more than a dozen consumer-laptop fires.
A typical lithium-ion battery consists of two tightly packed electrodes--a carbon anode and a lithium metal-oxide cathode--with an ultrathin polymer separator in between.
and ignite the flammable electrolyte solution that shuttles lithium ions back and forth. The separator is made of the same material used in plastic bottles said graduate student Denys Zhuo co-lead author of the study.
so that lithium ions can flow between the electrodes as the battery charges and discharges. Manufacturing defects such as particles of metal and dust can pierce the separator
and trigger shorting as Sony discovered in 2006. Shorting can also occur if the battery is charged too fast
Overcharging causes lithium ions to get stuck on the anode and pile up forming chains of lithium metal called dendrites Cui explained.
Smart separatorin the last couple of years we've been thinking about building a smart separator that can detect shorting before the dendrites reach the cathode said Cui a member of the photon science faculty at the SLAC National Accelerator Laboratory
so it has negligible effect on the flow of lithium ions between the cathode and the anode.
Most lithium-ion batteries are used in small electronic devices. But as the electric vehicle market expands
Some electric cars today are equipped with thousands of lithium-ion battery cells. If one battery explodes the whole pack can potentially explode.
This next generation of lithium-ion batteries will enable electric vehicles to charge 20 times faster than the current technology.
NTU Singapore's scientists replaced the traditional graphite used for the anode (negative pole) in lithium-ion batteries with a new gel material made from titanium dioxide an abundant cheap and safe material found in soil.
Naturally found in a spherical shape NTU Singapore developed a simple method to turn titanium dioxide particles into tiny nanotubes that are a thousand times thinner than the diameter of a human hair.
NTU professor Rachid Yazami who was the co-inventor of the lithium-graphite anode 34 years ago that is used in most lithium-ion batteries today said Prof Chen's invention is the next
While the cost of lithium-ion batteries has been reduced significantly and its performance improved since Sony commercialised it in 1991 the market is fast expanding towards new applications in electric mobility
since our batteries last ten times longer than the current generation of lithium-ion batteries The long-life of the new battery also means drivers save on the cost of a battery replacement
Easy to manufactureaccording to Frost & Sullivan a leading growth-consulting firm the global market of rechargeable lithium-ion batteries is projected to be worth US$23. 4 billion in 2016.
Lithium-ion batteries usually use additives to bind the electrodes to the anode which affects the speed in
which electrons and ions can transfer in and out of the batteries. However Prof Chen's new cross-linked titanium dioxide nanotube-based electrodes eliminate the need for these additives
Last year Prof Yazami was awarded the Draper Prize by the National Academy of Engineering for his ground-breaking work in developing the lithium-ion battery with three other scientists.
For this purpose the KIT scientists established a pilot plant at the hospital of Wonosari There bacteria in the water are reduced among others by UV radiation
The experiments were conducted at room temperature with particles of pure silver less than 10 nanometers across--less than one-thousandth of the width of a human hair.
or two atoms thick--actually move at any given time. As these outer layers of atoms move across the surface and redeposit elsewhere they give the impression of much greater movement
--but inside each particle the atoms stay perfectly lined up like bricks in a wall.
The interior is crystalline so the only mobile atoms are the first one or two monolayers Li says.
Everywhere except the first two layers is crystalline. By contrast if the droplets were to melt to a liquid state the orderliness of the crystal structure would be eliminated entirely--like a wall tumbling into a heap of bricks.
Technically the particles'deformation is pseudoelastic meaning that the material returns to its original shape after the stresses are removed--like a squeezed rubber ball--as opposed to plasticity as in a deformable lump of clay that retains a new shape.
For example in circuits where electrical contacts need to withstand rotational reconfiguration particles designed to maximize this effect might prove useful using noble metals
The findings could also help explain a number of anomalous results seen in other research on small particles Li says.
#Revving up fluorescence for superfast LEDS Duke university researchers have made fluorescent molecules emit photons of light 1000 times faster than normal--setting a speed record
In an LED atoms can be forced to emit roughly 10 million photons in the blink of an eye.
To make future light-based communications using LEDS practical researchers must get photon-emitting materials up to speed.
In a new study engineers from Duke increased the photon emission rate of fluorescent molecules to record levels by sandwiching them between metal nanocubes and a gold film.
which studies the interaction between electromagnetic fields and free electrons in metal. In the experiment her group manufactured 75-nanometer silver nanocubes
When fluorescent molecules are placed near intensified light the molecules emit photons at a faster rate through an effect called Purcell enhancement.
The researchers found they could achieve a significant speed improvement by placing fluorescent molecules in a gap between the nanocubes and a thin film of gold.
To attain the greatest effect Mikkelsen's team needed to tune the gap's resonant frequency to match the color of light that the molecules respond to.
That gap turned out to be just 20 atoms wide. But that wasn't a problem for the researchers.
and gap perfectly calibrated to the molecule that's when we see the record 1000-fold increase in fluorescence speed.
Because the experiment used many randomly aligned molecules the researchers believe they can do even better.
They plan to design a system with individual fluorescent molecule placed precisely underneath a single nanocube.
According to Akselrod they can achieve even higher fluorescence rates by standing the molecules up on edge at the corners of the cube.
If we can precisely place molecules like this it could be used in many more applications than just fast LEDS said Akselrod.
We could also make fast sources of single photons that could be used for quantum cryptography.
Many of his experiments depend on observing light in the form of photons--the particle complement of light waves
--and sometimes only one photon at a time, using"smart"detectors that can count the number of individual photons in a pulse.
when counting the number of photons in a light pulse, can really only count up to zero,
which sub-wavelength interference (to be defined below) has been pushed using thermal light and small-photon-number light detection.
by considering light as consisting of particles and using the correlations between those particles The JQI experiment starts out with a laser beam,
but it purposely degrades the coherence of the light by sending it through a moving disk of ground glass.
those for which each"click"denoting an arrival tells us only that more than zero photons have arrived?
we can arrange that the probability of more than one photon is very low, so a click tells us that with good accuracy that indeed just one photon has arrived.
But then if we design the light so that its limited coherence time is larger than the recovery time of our stupid detectors,
it is possible for the detector to tell us that a specific number of photons were recorded, perhaps 3 or 10,
This improved counting the number of photons, or equivalently the intensity of the light at various places at the measuring screen, ensures that the set of correlations between the two detectors does result in an interference-like pattern in those correlations.
Simple as it may seem her lab discovered that creating a pyramid-shaped layer of rubber instead of a flat mat gave the individual rubber molecules more freedom to flatten out and then spring back into shape.
and electron clouds to create a pressure gauge. Bao foresees many potential applications for this pressure-sensing technology.
stroke Scientists at The Scripps Research Institute (TSRI) have created a synthetic molecule that mimics oodcholesterol
The molecule, taken orally, improved cholesterol in just two weeks. This research, published in the October issue of Journal of Lipid Research, points scientists toward a new method for treating atherosclerosis,
In addition to Ghadiri, Leman, Zhao, Curtiss and Maryanoff, other contributors to the study, n vivo efficacy of HDL-like nanolipid particles containing multivalent peptide mimetics of apolipoprotein A-1,
For the very first time a general strategy to manufacture inorganic nanoparticles with user-specified 3d shapes has been achieved to produce particles as small as 25 nanometers or less with remarkable precision (less than 5 nanometers.
Just as any expanding material can be shaped inside a mold to take on a defined 3d form the Wyss team set out to grow inorganic particles within the confined hollow spaces of stiff DNA NANOSTRUCTURES.
and height of the particle able to be controlled independently. Next researchers fabricated varied 3d polygonal shapes spheres and more ambitious structures such as a 3d Y-shaped nanoparticle and another structure comprising a cuboid shape sandwiched between two spheres proving that structurally-diverse
For particles that would better serve their purpose by being as electrically conducive as possible such as in very small nanocomputers
The researchers showed that contact allergy brings inflammatory cells and molecules to the site of the allergic reaction.
and molecules become active at the site of the reaction. The new mix of cells and molecules promotes the development of skin tumors.
This model supported cancer development so strongly that some mice developed invasive squamous cell skin cancers similar to the patient's tumor said lead author Shadmehr Demehri MD Phd a dermatologist
and molecules involved in chronic contact allergy in mice they identified several that already had been linked to tumor development.
Some of these cells and molecules also were present in biopsy samples from the patient's ankle.
and molecules are most supportive of cancer formation. If you're allergic to something the first thing to do is to avoid it
"for detecting and characterizing even trace amounts of chemicals and biologically important molecules-from explosives, chemical warfare agents and environmental pollutants to disease markers.
or ripples, of electrons that exist on the surfaces of materials, and in particular metals such as gold.
"For example, Tian noted, the plasmonic paper can be used to detect target molecules that serve as indicators for diseases such as kidney cancer."
coveted for their ability to let electrons flow without resistance. While testing his latest candidate the semimetal tungsten ditelluride (WTE2) he noticed a peculiar result.
Electron microscopy experiments revealed the presence of tungsten dimers paired tungsten atoms arranged in chains responsible for the key distortion from the classic octahedral structure type.
The research team proposed that WTE2 owes its lack of saturation to the nearly perfect balance of electrons and electron holes
which are empty docks for traveling electrons. Because of its structure WTE2 only exhibits magnetoresistance when the magnetic field is applied in a certain direction This could be very useful in scanners where multiple WTE2 devices could be used to detect the position of magnetic fields Ali said.
#Discovery of new subatomic particle, type of meson, to transform understanding of fundamental force of nature The discovery of a new particle will transform our understanding of the fundamental force of nature that binds the nuclei of atoms researchers argue.
Led by scientists from the University of Warwick the discovery of the new particle will help provide greater understanding of the strong interaction the fundamental force of nature found within the protons of an atom's nucleus. Named Ds3*(2860) the particle
a new type of meson 1 was discovered by analysing data collected with the LHCB detector at CERN's Large hadron collider (LHC) 2. The new particle is bound together in a similar way to protons.
Due to this similarity the Warwick researchers argue that scientists will now be able to study the particle to further understand strong interactions.
Along with gravity the electromagnetic interaction and weak nuclear force strong-interactions are one of four fundamental forces. Lead scientist Professor Tim Gershon from The University of Warwick's Department of physics explains:
whilst the electromagnetic interaction is responsible for binding molecules together and also for holding electrons in orbit around an atom's nucleus. The strong interaction is the force that binds quarks the subatomic particles that form protons within atoms together.
It is so strong that the binding energy of the proton gives a much larger contribution to the mass through Einstein's equation E=mc2 than the quarks themselves. 3 Due in part to the forces'relative simplicity scientists have previously been able to solve the equations behind gravity
and electromagnetic interactions but the strength of the strong interaction makes it impossible to solve the equations in the same way Calculations of strong interactions are done with a computationally intensive technique called Lattice QCD says Professor Gershon.
In order to validate these calculations it is essential to be able to compare predictions to experiments.
The new particle is ideal for this purpose because it is known the first that both contains a charm quark
and has spin 3. There are six quarks known to physicists; Up Down Strange Charm Beauty and Top.
Protons and neutrons are composed of up and down quarks but particles produced in accelerators such as the LHC can contain the unstable heavier quarks.
In addition some of these particles have higher spin values than the naturally occurring stable particles.
Because the Ds3*(2860) particle contains a heavy charm quark it is easier for theorists to calculate its properties.
And because it has spin 3 there can be no ambiguity about what the particle is adds Professor Gershon.
Therefore it provides a benchmark for future theoretical calculations. Improvements in these calculations will transform our understanding of how nuclei are bound together.
Spin is one of the labels used by physicists to distinguish between particles. It is a concept that arises in quantum mechanics that can be thought of as being similar to angular momentum:
in this sense higher spin corresponds to the quarks orbiting each other faster than those with a lower spin.
Warwick Ph d. student Daniel Craik who worked on the study adds Perhaps the most exciting part of this new result is that it could be the first of many similar discoveries with LHC data.
Whether we can use the same technique as employed with our research into Ds3*(2860) to also improve our understanding of the weak interaction is a key question raised by this discovery.
If so this could help to answer one of the biggest mysteries in physics: why there is more matter than antimatter in the Universe.
Notes 1 The Ds3*(2860) particle is a meson that contains a charm antiquark and a strange quark.
The subscript 3 denotes that it has spin 3 while the number 2860 in parentheses is the mass of the particle in the units of Mev/c2 that are favoured by particle physicists.
The value of 2860 Mev/c2 corresponds to approximately 3 times the mass of the proton. 2 The particle was discovered in the decay chain Bs0#D0k-p+where the Bs0 D0 K
-and p+mesons contain respectively a bottom antiquark and a strange quark a charm antiquark and an up quark an up antiquark and a strange quark and a down antiquark and an up quark.
The Ds3*(2860) particle is observed as a peak in the mass of combinations of the D0 and K-mesons.
The distributions of the angles between the D0 K-and p+particles allow the spin of the Ds3*(2860) meson to be determined unambiguously. 3 Quarks are bound by the strong interaction into one of two types of particles:
baryons such as the proton are composed of three quarks; mesons are composed of one quark and one antiquark where an antiquark is the antimatter version of a quark.
Story Source: The above story is provided based on materials by University of Warwick. Note: Materials may be edited for content and length.
Journal References l
#Discovery may lead to lower doses of chemotherapy No matter what type of chemotherapy you attack a tumor with,
many cancer cells resort to the same survival tactic: They start eating themselves. Scientists at Brigham Young University discovered the two proteins that pair up
precisely Optical emission spectrometers are used widely in the steel industry but the instruments currently employed are relatively large and bulky.
Jewelers in India are required by law to test the purity of gold using an optical emission spectrometer that analyzes the composition of the metal on the basis of the emitted light spectrum.
Researchers at the Fraunhofer Institute for Microelectronic Circuits and Systems IMS in Duisburg have developed a sensor that shrinks the size of the spectrometer optics.
Whereas earlier high-resolution spectrometers were the size of a washing machine those built using our sensor will be no bigger than a microwave oven says IMS department head Werner Brockherde.
These sparks knock atoms out of the material resulting in a plasma that emits multicolored light.
This reveals the nature and concentration of particles suspended in the plasma from which it is possible to derive information on the composition of the steel sample.
The new photodetector multiplies the dynamic range by 100 resulting in a much faster spectrometer.
#RNA molecules found in urine, tissue that detect prostate cancer Researchers at Sanford-Burnham Medical Research Institute have identified a set of RNA molecules that are detectable in tissue samples and urine of prostate cancer patients,
but not in normal healthy individuals. The study sets the stage for the development of more-sensitive and specific noninvasive tests for prostate cancer than those currently available,
"The researchers believe that they have identified a group of RNA molecules--known as long noncoding RNAS (lncrnas)--that hold the potential for serving as better prognostic markers for prostate cancer. lncrnas are non-coding RNA
molecules that until recently were dismissed by scientists as nonfunctional noise in the genome. Now, lncrnas are thought to regulate normal cellular development
One advantage of lncrnas is that the molecules can be detected in urine samples, which are more easily available than blood tests.
"We have used osseointegration to create a long-term stable fusion between man and machine, where we have integrated them at different levels.
how surface proteins on the virus behave will hopefully tell us what we need to know to prevent fusion with human cells
"What we have shown in the Science study is that we now have the means to obtain real-time images of processes happening on the surface of intact HIV particles,
Dr. Blanchard adapted an imaging technique that uses fluorescence to measure distance on molecular scale--single-molecule fluorescence resonance energy transfer (smfret) imaging--to study viral particles.
His group developed fluorescent molecules (fluorophores) --which he dubs"beacons "--and the team inserted them into the virus's outer covering, known as the envelope.
With two of these special beacons in place, smfret imaging can be used to visualize how the molecules move over time,
"There are 10-20 such envelope trimers on the surface of each HIV particle, and they mutate rapidly,
which contained beacons that did not alter the biology of the particles. Then they watched.
They saw that the gp120 proteins'virus particles changed shape constantly and that the timing and nature of their movements were both similar and distinct."
"Many scientists believe that the particles remain in one conformation until they come across a CD4-positive cell.
when they introduced a small molecule now under development to prevent HIV infection.""The practical outcome from this technology is that we can begin to understand how the biological system moves.
what the pre-fusion machinery looks like and where these antibodies bind provides an important step forward to understanding HIV's biology,
and X-ray crystallography--can work hand in hand to help scientists describe the functions of molecules from the perspective motion,
because most research is done in a test tube where billions of molecules are present, all behaving independently.
"The single-molecule approach allows practical, interpretable, real-time information to be obtained about molecular processes in complex biological systems
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