The proteins that drive DNA replication are some of the most complex machines on Earth and the process involves hundreds of atomic-scale moving parts that rapidly interact and transform. Now, scientists have pinpointed crucial steps in the beginning of the replication process, including surprising structural details about the enzyme that "unzips" and splits the DNA double helix so the two halves can serve as templates for DNA duplication.
Mazhar Ali, a fifth-year graduate student in the laboratory of Bob Cava, the Russell Wellman Moore Professor of Chemistry at Princeton Univ., has spent his academic career discovering new superconductors, materials 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.
Hepatitis C, an infectious disease of the liver caused by the hepatitis C virus (HCV), affects 160 million people worldwide. There’s no vaccine for HCV and the few treatments that are available do not work on all variants of the virus. Before scientists can develop potential vaccines and additional therapies they must first thoroughly understand the molecular-level activity that takes place when the virus infects a host cell.
Increasing the oil content of plant biomass could help fulfill the nation's increasing demand for renewable energy feedstocks. But many of the details of how plant leaves make and break down oils have remained a mystery. Now a series of detailed genetic studies conducted at Brookhaven National Laboratory reveals previously unknown biochemical details about those metabolic pathways.
Heat drives classical phase transitions, but much stranger things can happen when the temperature drops. If phase transitions occur at the coldest temperatures imaginable, where quantum mechanics reigns, subtle fluctuations can dramatically transform a material. Scientists have explored this frigid landscape of absolute zero to isolate and probe these quantum phase transitions with unprecedented precision.
Using a calculation originally proposed seven years ago to be performed on a petaflop computer, Lawrence Livermore National Laboratory researchers computed conditions that simulate the birth of the universe. When the universe was less than one microsecond old and more than one trillion degrees, it transformed from a plasma of quarks and gluons into bound states of quarks.
Cadmium zinc telluride (CZT) gamma-ray detectors are important new components in spectroscopic imaging systems because they are the first detectors capable of distinguishing natural gamma-ray background and radioactive isotopes without the need for bulky cooling equipment. The technological difficulties of producing perfect crystals, however, have hindered widespread usage. Brookhaven National Laboratory has successfully addressed these challenges with the introduction of the GammaScout.
New supercomputing calculations provide the first evidence that particles predicted by the theory of quark-gluon interactions but never before observed are being produced in heavy-ion collisions at the Relativistic Heavy Ion Collider, a facility that is dedicated to studying nuclear physics. These heavy strange baryons, containing at least one strange quark, still cannot be observed directly.
Electronic devices with unprecedented efficiency and data storage may someday run on ferroelectrics—remarkable materials that use built-in electric polarizations to read and write digital information, outperforming the magnets inside most popular data-driven technology. But ferroelectrics must first overcome a few key stumbling blocks, including a curious habit of "forgetting" stored data.
Using a new method to track the electrochemical reactions in a common electric vehicle battery material under operating conditions, scientists at Brookhaven National Laboratory have revealed new insight into why fast charging inhibits this material's performance. The study also provides the first direct experimental evidence to support a particular model of the electrochemical reaction.
Lithium (Li)-ion batteries power almost all of the portable electronic devices that we use every day, including smartphones, cameras, toys and even electric cars. Researchers across the globe are working to find materials that will lead to safe, cheap, long-lasting and powerful Li-ion batteries.
Scientists running the ATLAS experiment at the Large Hadron Collider report the first evidence of a process that can be used to test the mechanism by which the recently discovered Higgs particle imparts mass to other fundamental particles. More rare than the production of the Higgs itself, this process also provides a new stringent test of the Standard Model of particle physics.
Researchers at The Johns Hopkins Univ. report they have deciphered the inner workings of a protein called YiiP that prevents the lethal buildup of zinc inside bacteria. They say understanding YiiP's movements will help in the design of drugs aimed at modifying the behavior of ZnT proteins, eight human proteins that are similar to YiiP, which play important roles in hormone secretion and in signaling between neurons.
Scientists seeking ways to engineer the assembly of tiny particles measuring just billionths of a meter have achieved a new first: the formation of a single layer of nanoparticles on a liquid surface where the properties of the layer can be easily switched. Understanding the assembly of such nanostructured thin films could lead to the design of new kinds of membranes with a variable mechanical response for a wide range of applications.
Sometimes a cell has to die—when it's done with its job or inflicted with injury that could otherwise harm an organism. Conversely, cells that refuse to die when expected can lead to cancer. So scientists interested in fighting cancer have been keenly interested in learning the details of "programmed cell death." They want to understand what happens when this process goes awry and identify new targets for anticancer drugs.
Wouldn’t it be nice to use solar- or wind-generated electricity to turn excess carbon dioxide into fuels and other useful chemicals? The process would store up the intermittent solar or wind energy in a form that could be used when and where it was needed, including in transportation applications, all while getting rid of some greenhouse gas.
Batteries don’t age gracefully. The lithium ions that power portable electronics cause lingering structural damage with each cycle of charge and discharge, making devices from smartphones to tablets tick toward zero faster and faster over time. To stop or slow this steady degradation, scientists must track and tweak the imperfect chemistry of lithium-ion batteries with nanoscale precision.
In recent work at Brookhaven National Laboratory, semiconductor quantum dots (QDs) have been combined with graphene to develop nanoscale photonic devices that can dramatically improve our ability to detect light. The research has demonstrated that the thickness of the organic molecule layer that typically surrounds the QDs is crucial in attaining sufficiently high efficiency of light/energy transfer into the graphene.
Plant scientists at Brookhaven National Laboratory have found that certain enzymes responsible for desaturating fatty acids, the building blocks of oils, can link up to efficiently pass intermediate products from one enzyme to another. The research lead to the development of plants that can accumulate high levels of more healthful polyunsaturated fatty acids, or fatty acids that could be used as raw materials in place of petroleum.
Scientists at Brookhaven National Laboratory are seeking ways to synchronize the magnetic spins in nanoscale devices to build tiny yet more powerful signal-generating or receiving antennas and other electronics. Their latest work shows that stacked nanoscale magnetic vortices separated by a thin layer of copper can be driven to operate in unison, potentially producing a powerful signal that could be put to work in new electronics.
Using principles of energy transfer more commonly applied to designing solar cells, scientists at Brookhaven National Laboratory have developed a new highly sensitive way to detect specific sequences of DNA, the genetic material unique to every living thing. The method is considerably less costly than other DNA assays and has widespread potential for applications in forensics, medical diagnostics and the detection of bioterror agents.
Ever-shrinking electronic devices could get down to atomic dimensions with the help of transition metal oxides. Researchers from Cornell Univ. and Brookhaven National Laboratory have shown how to switch a particular transition metal oxide, a lanthanum nickelate (LaNiO3), from a metal to an insulator by making the material less than a nanometer thick.
Carefully timed pairs of laser pulses at the Linac Coherent Light Source have been used to trigger superconductivity in a promising copper-oxide material and immediately take x-ray snapshots of its atomic and electronic structure as superconductivity emerged. The results of this effort have pinned down a major factor behind the appearance of superconductivity, and it hinges around “stripes” of increase electrical charge.
Scientists at Brookhaven National Laboratory have made the first 3-D observations of how the structure of a lithium-ion battery anode evolves at the nanoscale in a real battery cell as it discharges and recharges. The details of this research, described in a paper published in Angewandte Chemie, could point to new ways to engineer battery materials to increase the capacity and lifetime of rechargeable batteries.
From steel beams to plastic Lego bricks, building blocks come in many materials and all sizes. Today, science has opened the way to manufacturing at the nanoscale with biological materials. Potential applications range from medicine to optoelectronic devices. In a paper published in Soft Matter, scientists announced their discovery of a 2-D crystalline structure assembled from the outer shells of a virus.