In the developing brain, special proteins that act like molecular tugboats push or pull on growing nerve cells, or neurons, helping them navigate to their assigned places amidst the brain’s wiring. How a single protein can exert both a push and a pull force to nudge a neuron in the desired direction is a longstanding mystery that has now been solved by scientists from Dana-Farber Cancer Institute.
Neurons communicate with each other through...
Biological physicists at Rice Univ. have succeeded...
Prothrombin is an inactive precursor for thrombin...
The term “crowdsourcing” was coined in 2006 and since then has seen its definition broadened to a wide range of activities involving a network of people. A challenging problem that might benefit from crowdsourcing, according to recently published research, is the phase problem in x-ray crystallography. Retrieving the phase information has plagued many scientists for decades when trying to determine the crystal structure of a sample.
Researchers in Australia have discovered how algae that survive in very low levels of light are able to switch on and off a weird quantum phenomenon that occurs during photosynthesis. The function in the algae of this quantum effect, known as coherence, remains a mystery, but it is thought it could help them harvest energy from the sun much more efficiently.
Using synchrotron light, scientists have pioneered a new way to analyze delicate biomolecules. The new approach, called protein serial crystallography, is made possible by a new class of high-intensity x-ray sources called free-electron lasers and could reveal the atomic structure of proteins that were previously inaccessible to synchrotrons.
Using a doped-graphene matrix to slow down and then trap atoms of the precious metal osmium, researchers in the U.K. have shown the ability to control and quantify the growth of metal-crystals. When the trapped atoms come into contact with further osmium atoms they bind together, eventually growing into 3-D metal-crystals. They have called this new technique nanocrystallometry.
Melanin—and specifically, the form called eumelanin—is the primary pigment that gives humans the coloring of their skin, hair and eyes. It protects the body from the hazards of ultraviolet and other radiation that can damage cells and lead to skin cancer, but the exact reason why the compound is so effective at blocking such a broad spectrum of sunlight has remained something of a mystery.
The ability to control crystals with light and chemistry could lead to chameleon-style color-changing camouflage for vehicle bodies and other surfaces. Univ. of Michigan researchers discovered a template-free method for growing shaped crystals that allows for changeable structures that could appear as different colors and patterns.
Researchers from the NIST Center for Nanoscale Science and Technology have observed electromagnetically induced transparency at room temperature and atmospheric pressure in a silicon nitride optomechanical system. This work highlights the potential of silicon nitride as a material for producing integrated devices in which mechanical vibrations can be used to manipulate and modify optical signals.
An unwanted byproduct from a bygone method of glass production, the crystal devitrite could find a new use as an optical diffuser in medical laser treatments, communications systems and household lighting. For years, the properties of this material were not studied because it was considered as just a troublemaker in the glass-making process and needed to be eliminated.
A new tool for analyzing mountains of data from SLAC National Accelerator Laboratory’s Linac Coherent Lightsource x-ray laser can produce high-quality images of important proteins using fewer samples. Scientists hope to use it to reveal the structures and functions of proteins that have proven elusive, as well as mine data from past experiments for new information.
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.
Computational biologists in Austria have recently shown that the common practice of averaging is not always a good thing when it comes to analyzing protein crystal structures. A study shows that protein structures could be more dynamic and heterogeneous than current methods of x-ray analysis suggest.
Lawrence Berkeley National Laboratory researchers have produced the first detailed look at the 3-D structure of the Cas9 enzyme and how it partners with guide RNA to interact with target DNA. The results should enhance Cas9’s value and versatility as a genome-editing tool.
The sponges of the future will do more than clean house. Picture this, for example: Doctors use a tiny sponge to soak up a drug and deliver it directly to a tumor. Chemists at a manufacturing plant use another to trap and store unwanted gases. These technologies are what a Univ. at Buffalo team had in mind when they led the design of a new material called UBMOF-1.
A research group based in Japan has succeeded for the first time in fabricating a 3-D structure of a quasicrystal composed of a single element. Discovered in 1984, quasicrystals have been found in more than 100 kinds of alloy, polymer and nanoparticle systems. However, a quasicrystal composed of a single element has not yet been found.
Researchers have combined cutting-edge experimental techniques and computer simulations to find a new way of predicting how water dissolves crystalline structures like those found in natural stone and cement. The research could have wide-ranging impacts in diverse areas, including water quality and planning, environmental sustainability, corrosion resistance and cement construction.
Scientists from NIST and Sandia National Laboratories have added something new to a family of engineered, high-technology materials called metal-organic frameworks (MOFs): the ability to conduct electricity. This breakthrough—conductive MOFs—has the potential to make these already remarkable materials even more useful, particularly for detecting gases and toxic substances.
An interdisciplinary team of University of Pennsylvania researchers has already developed a technique for controlling liquid crystals by means of physical templates and elastic energy, rather than the electromagnetic fields that manipulate them in televisions and computer monitors. They envision using this technique to direct the assembly of other materials, such as nanoparticles.
New York Univ. chemists have discovered crystal growth complexities, which at first glance appeared to confound 50 years of theory and deepened the mystery of how organic crystals form. But, appearances can be deceiving. The researchers focused on L-cystine crystals, the chief component of a particularly nefarious kind of kidney stone.
Researchers at the Virginia Tech Carilion Research Institute have reported the first experimental evidence that supports the theory that a soccer ball-shaped nanoparticle, commonly called a buckyball, is the result of a breakdown of larger structures rather than being built atom-by-atom from the ground up.
Computer simulations conducted at Lawrence Berkeley National Laboratory could help scientists make sense of a recently observed and puzzling wrinkle in one of nature’s most important chemical processes. It turns out that calcium carbonate may momentarily exist in liquid form as it crystallizes from solution.
By determining the 3-D structure of proteins at the atomic level, researchers at the National Institutes of Health have discovered how some commonly used flame retardants, called brominated flame retardants (BFRs), can mimic estrogen hormones and possibly disrupt the body’s endocrine system. BFRs are chemicals added or applied to materials to slow or prevent the start or growth of fire.
A new study from an international team led by Oak Ridge National Laboratory is guiding drug designers toward improved pharmaceuticals to treat HIV. The scientists used neutrons and x-rays to study the interactions between HIV protease, a protein produced by the HIV virus, and an antiviral drug commonly used to block virus replication.
Researchers have been investigating the formation of defects occurring when a Coulomb crystal of ions is driven through a second-order phase transition. This process effectively models the universal Kibble-Zurek mechanism which describes the formation of such defects and is the basis of one theory of how matter was created 10-30 seconds after the Big Bang.
Nanocrystals can grab specific molecules and particles out the air, hold on to them and then release them. But progress in utilizing adsorption and desorption has been hindered by limitations in existing methods for measuring the physical and chemical changes that take place in individual nanocrystals. A newly developed system may solve this by directly measuring the manner in which nanocrystals adsorb and release hydrogen and other gases.
In some ways, granular material can behave much like a crystal, with its close-packed grains mimicking the precise, orderly arrangement of crystalline atoms. Now researchers at Massachusetts Institute of Technology have pushed that similarity to a new limit, creating 2-D arrays of micrograins that can funnel acoustic waves, much as specially designed crystals can control the passage of light or other waves.
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