By attaching short sequences of single-stranded DNA to nanoscale building blocks, researchers can design structures that can effectively build themselves. The building blocks that are meant to connect have complementary DNA sequences on their surfaces, ensuring only the correct pieces bind together as they jostle into one another while suspended in a test tube.
Combatting the tissue degrading enzymes that cause...
Scientists have modified genes in the blood cells of HIV patients to help them resist the AIDS...
When deciding what materials to use in building something, determining how those materials...
For centuries, geologists have recognized that the rocks that line riverbeds tend to be smaller and rounder further downstream. But these experts have not agreed on the reason these patterns exist. Does abrasion reduce the size of rocks significantly, or is it that smaller rocks are simply more easily transported downstream? A new study has arrived at a resolution to this puzzle.
Optogenetics allows scientists to control neurons’ electrical activity with light by engineering them to express light-sensitive proteins, called opsins. Most opsins respond to light in the blue-green range. Now, a team has discovered an opsin that is sensitive to red light, which allows researchers to independently control the activity of two populations of neurons at once, enabling much more complex studies of brain function.
A new MRI method to map creatine at higher resolutions in the heart may help clinicians and scientists find abnormalities and disorders earlier than traditional diagnostic methods, researchers at the Univ. of Pennsylvania suggest in a recent study. The preclinical findings show an advantage over less sensitive tests and point to a safer and more cost-effective approach than those with radioactive or contrasting agents.
The field of metamaterials has produced structures with unprecedented abilities, including flat lenses, invisibility cloaks and even optical metatronic devices that can manipulate light in the way electronic circuitry manipulates the flow of electrons. Now, the birthplace of the digital computer, ENIAC, is using this technology in the rebirth of analog computing.
In earlier studies, a team from the Univ. of Pennsylvania produced nanoscale grids and rings of “defects,” or useful disruptions in the repeating patterns found in liquid crystals. Their latest study adds a more complex pattern out of an even simpler template: A 3-D array in the shape of a flower. This advances the use of liquid crystals as a medium for assembling structures.
Cancer involves a breakdown of normal cell behavior. Cell reproduction and movement go haywire, causing tumors to grow and spread through the body. A new finding by Univ. of Pennsylvania scientists has identified key steps that trigger this disintegration of cellular regulation. Their discovery—that a protein called Exo70 has a split personality—points to new possibilities for diagnosing cancer metastasis.
A unique solar panel design made with a new ceramic material points the way to potentially providing sustainable power cheaper, more efficiently, and requiring less manufacturing time. It also reaches a four-decade-old goal of discovering a bulk photovoltaic material that can harness energy from visible and infrared light, not just ultraviolet light.
The blood stem cells that live in bone marrow are at the top of a complex family tree. Such stem cells split and divide down various pathways that ultimately produce red cells, white cells and platelets. These “daughter” cells must be produced at a rate of about one million per second to constantly replenish the body’s blood supply. Researchers have long wondered what allows these stem cells to persist for decades, until now.
Researchers from the Univ. of Pennsylvania and Drexel Univ. have experimentally demonstrated a new method for solar cell construction which may ultimately make them less expensive, easier to manufacture and more efficient at harvesting energy from the sun. The breakthrough, which is the result of five years of focused research, relies on specifically designed perovskite crystals that deliver a “bulk” photovoltaic effect.
Researchers from the Univ. of Pennsylvania have demonstrated a new mechanism for extracting energy from light, a finding that could improve technologies for generating electricity from solar energy and lead to more efficient optoelectronic devices used in communications.
Electronic devices with touchscreens rely on transparent conductors made of indium tin oxide, or ITO. But cost and the physical limitations of this material are limiting progress in developing flexible touchscreens. A research collaboration between the Univ. of Pennsylvania and Duke Univ. is exploring the use of nanowires to replace ITO, and are using simulation tools to determine how they might work.
Nanoscientists who recently created beautiful, tiled patterns with flat nanocrystals faced a mystery: Why did crystals arrange themselves in an alternating, herringbone style, even though it wasn’t the simplest pattern? Help from computer simulations have given them a new tool for controlling how objects one-millionth the size of a grain of sand arrange themselves into useful materials.
Catalysts are everywhere. They make chemical reactions that normally occur at extremely high temperatures and pressures possible within factories, cars and the comparatively balmy conditions within the human body. Developing better catalysts, however, is mainly a hit-or-miss process. Now, researchers have shown a way to precisely design the active elements of a certain class of catalysts.
Catalysts are everywhere, but developing better catalysts is mainly a hit-or-miss process. Now, a study by researchers at the University of Pennsylvania, the University of Trieste, Italy, and Brookhaven National Laboratory has shown a way to precisely design the active elements of a certain class of catalysts, showing which parameters are most critical for improving performance.
Opioids are still the most effective class of painkillers, but they come with unwanted side effects. Designing new drugs of this type involves testing them on their corresponding receptors, but access to meaningful quantities of these receptors that work in experimental conditions has been a limiting factor. Now, researchers have developed a variant of the mu opioid receptor that has several advantages when it comes to experimentation.
Cartilage injuries have ended many athletes’ career, and the general wear-and-tear of the joint-cushioning tissue is something that almost everyone will endure as they age. Unfortunately, repairing cartilage remains difficult. Bioengineers are interested in finding innovative ways to grow new cartilage from a patient’s own stem cells. A new study from the Univ. of Pennsylvania brings such a treatment one step closer to reality.
The quintessential piece of origami might be a decorative paper crane, but in the hands of an interdisciplinary Univ. of Pennsylvania research team, it could lead to a drug-delivery device, an emergency shelter or even a space station. Collaborating with researchers at Cornell Univ., the Penn team will share in a $2 million, four-year grant from the NSF’s Div. of Emerging Frontiers in Research and Innovation.
A team of University of Pennsylvania engineers has used a pattern of nanoantennas to develop a new way of turning infrared light into mechanical action, opening the door to more sensitive infrared cameras and more compact chemical analysis techniques.
Leading nanoscientists created beautiful, tiled patterns with flat nanocrystals, but they were left with a mystery: Why did some sets of crystals arrange themselves in an alternating, herringbone style? To find out, they turned to experts in computer simulation at the University of Michigan and the Massachusetts Institute of Technology.
The allure of personalized medicine has made new, more efficient ways of sequencing genes a top research priority. One promising technique involves reading DNA bases using changes in electrical current as they are threaded through a nanoscopic hole. Now, a team led by University of Pennsylvania physicists has used solid-state nanopores to differentiate single-stranded DNA molecules containing sequences of a single repeating base.
A dye-based imaging technique known as two-photon microscopy can produce pictures of active neural structures in much finer detail than functional magnetic resonance imaging, but it requires expensive femtosecond lasers to fluoresce existing dyes. A research team at the University of Pennsylvania has developed a new kind dye that fluoresces easily and produces quality images with far less powerful lasers.
A new study by a team of scientists defines previously unknown properties of transmitted HIV-1, the virus that causes AIDS. The viruses that successfully pass from a chronically infected person to a new individual are both remarkably resistant to a powerful initial human immune-response mechanism, and they are blanketed in a greater amount of envelope protein that helps them access and enter host cells.
Certain semiconductors, when imparted with energy, in turn emit light; they directly produce photons, instead of producing heat. This phenomenon is commonplace and used in light-emitting diodes, or LEDs. Research from the University of Pennsylvania has enabled "bulk" silicon to emit broad-spectrum, visible light for the first time, opening the possibility of using the element in devices that have both electronic and photonic components.
Beyond serving as the backbone of modern biology, DNA has come to be a molecule of great interest to engineers. That a DNA sequence will naturally bind only with a complementary sequence could make it part of a configurable, and potentially programmable, building material. Researchers at the University of Pennsylvania have now used DNA to make a crystal that can switch into a more stable configuration under the right temperature conditions, much like heat-treated steel.
Wear is a fact of life. As surfaces rub against one another, they break down and lose their original shape. With less material to start with and functionality that often depends critically on shape and surface structure, wear affects nanoscale objects more strongly than it does their macroscale counterparts. Worse, the mechanisms behind wear processes aren't well understood for nanotech devices. Until now.
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