Archive for the ‘biological’ category: Page 91

Apr 13, 2021

Topological insulator metamaterial with giant circular photogalvanic effect

Posted by in categories: biological, chemistry, food, nanotechnology, physics, space

Topological insulators have notable manifestations of electronic properties. The helicity-dependent photocurrents in such devices are underpinned by spin momentum-locking of surface Dirac electrons that are weak and easily overshadowed by bulk contributions. In a new report now published on Science Advances, X. Sun and a research team in photonic technologies, physics and photonic metamaterials in Singapore and the U.K. showed how the chiral response of materials could be enhanced via nanostructuring. The tight confinement of electromagnetic fields in the resonant nanostructures enhanced the photoexcitation of spin-polarized surface states of a topological insulator to allow an 11-fold increase of the circular photogalvanic effect and a previously unobserved photocurrent dichroism at room temperature. Using this method, Sun et al. controlled the spin transport in topological materials via structural design, a hitherto unrecognized ability of metamaterials. The work bridges the gap between nanophotonics and spin electronics to provide opportunities to develop polarization-sensitive photodetectors.


Chirality is a ubiquitous and fascinating natural phenomenon in nature, describing the difference of an object from its mirror image. The process manifests in a variety of scales and forms from galaxies to nanotubes and from organic molecules to inorganic compounds. Chirality can be detected at the atomic and molecular level in fundamental sciences, including chemistry, biology and crystallography, as well as in practice, such as in the food and pharmaceutical industry. To detect chirality, scientists can use interactions with electromagnetic fields, although the process can be hindered by a large mismatch between the wavelength of light and the size of most molecules at nanoscale dimensions. Designer metamaterials with structural features comparable to the wavelength of light can provide an independent approach to devise optical properties on demand to enhance the light-matter interaction to create and enhance the optical chirality of metamaterials. In this work, Sun et al.

Apr 12, 2021

Xenobots: Living, Biological Robots that Work in Swarms

Posted by in categories: biological, robotics/AI, supercomputing

As the Tufts scientists were creating the physical xenobot organisms, researchers working in parallel at the University of Vermont used a supercomputer to run simulations to try and find ways of assembling these living robots in order to perform useful tasks.

Scientists at Tufts University have created a strange new hybrid biological/mechanical organism that’s made of living cells, but operates like a robot.

Apr 10, 2021

Dr. Suzan Murray, D.V.M., Smithsonian / SCBI — Wildlife Care And Combating Emerging Zoonotic Disease

Posted by in categories: biological, biotech/medical, health

Wildlife Care And Combating Emerging Zoonotic Diseases — Dr. Suzan Murray, D.V.M., D.A.C.Z.M. Smithsonian’s National Zoo and Conservation Biology Institute, Program Director, Global Health Program.

Dr. Suzan Murray, D.V.M., D.A.C.Z.M. is a board-certified zoo veterinarian at the Smithsonian Conservation Biology Institute (SCBI) and serves as both the Program Director of the Global Health Program and as SCBI’s chief wildlife veterinary medical officer.

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Apr 9, 2021

An Evolutionary Discovery That “Literally Changes the Textbook”

Posted by in categories: biological, genetics, health, neuroscience

MSU’s expertise in fish biology, genetics helping researchers rewrite evolutionary history and shape future health studies.

The network of nerves connecting our eyes to our brains is sophisticated and researchers have now shown that it evolved much earlier than previously thought, thanks to an unexpected source: the gar fish.

Michigan State University’s Ingo Braasch has helped an international research team show that this connection scheme was already present in ancient fish at least 450 million years ago. That makes it about 100 million years older than previously believed.

Apr 6, 2021

Research team discovers use of elasticity to position microplates on curved 2D fluids

Posted by in categories: bioengineering, biological

A team of polymer science and engineering researchers at the University of Massachusetts Amherst has demonstrated for the first time that the positions of tiny, flat, solid objects integrated in nanometrically thin membranes—resembling those of biological cells—can be controlled by mechanically varying the elastic forces in the membrane itself. This research milestone is a significant step toward the goal of creating ultrathin flexible materials that self-organize and respond immediately to mechanical force.

The team has discovered that rigid solid plates in biomimetic fluid membranes experience interactions that are qualitatively different from those of biological components in cell membranes. In cell membranes, fluid domains or adherent viruses experience either attractions or repulsions, but not both, says Weiyue Xin, lead author of the paper detailing the research, which recently appeared in Science Advances. But in order to precisely position solid objects in a membrane, both attractive and repulsive forces must be available, adds Maria Santore, a professor of polymer science and engineering at UMass. In the Santore Lab at UMass, Xin used giant unilamellar vesicles, or GUVs, which are cell-like membrane sacks, to probe the interactions between solid objects in a thin, sheet-like material. Like biological cells, GUVs have fluid membranes and form a nearly spherical shape. Xin modified the GUVs so that the membranes included tiny, solid, stiff plate-like masses.

Apr 5, 2021

Sneaky New Bacteria on the ISS Could Build a Future on Mars

Posted by in categories: biological, space

NASA tracks the microbes that live on the space station, and sometimes it discovers new ones. Those hardy bugs may offer clues about surviving long missions.

Apr 4, 2021

A cellular platform for the development of synthetic living machines

Posted by in categories: biological, robotics/AI

Robot swarms have, to date, been constructed from artificial materials. Motile biological constructs have been created from muscle cells grown on precisely shaped scaffolds. However, the exploitation of emergent self-organization and functional plasticity into a self-directed living machine has remained a major challenge. We report here a method for generation of in vitro biological robots from frog (Xenopus laevis) cells. These xenobots exhibit coordinated locomotion via cilia present on their surface. These cilia arise through normal tissue patterning and do not require complicated construction methods or genomic editing, making production amenable to high-throughput projects.

Apr 3, 2021

Artificial life can grow and divide normally

Posted by in categories: bioengineering, biological

A breakthrough in synthetic biology could shed new light on mechanisms controlling the most basic processes of life.

Apr 2, 2021

Dynamic model of SARS-CoV-2 spike protein reveals potential new vaccine targets

Posted by in categories: biological, biotech/medical, computing

A new, detailed model of the surface of the SARS-CoV-2 spike protein reveals previously unknown vulnerabilities that could inform development of vaccines. Mateusz Sikora of the Max Planck Institute of Biophysics in Frankfurt, Germany, and colleagues present these findings in the open-access journal PLOS Computational Biology.

SARS-CoV-2 is the virus responsible for the COVID-19 pandemic. A key feature of SARS-CoV-2 is its spike , which extends from its and enables it to target and infect human cells. Extensive research has resulted in detailed static models of the spike protein, but these models do not capture the flexibility of the spike protein itself nor the movements of protective glycans—chains of sugar molecules—that coat it.

To support vaccine development, Sikora and colleagues aimed to identify novel potential target sites on the surface of the spike protein. To do so, they developed that capture the complete structure of the spike protein and its motions in a realistic environment.

Mar 29, 2021

Bacteria Could Be The First Organisms Found to Use Quantum Effects to Survive

Posted by in categories: biological, chemistry, quantum physics

Bacteria have been found exploiting quantum physics to survive.

Oxygen is life to animals like us. But for many species of microbe, the smallest whiff of the highly reactive element puts their delicate chemical machinery at risk of rusting up.

The photosynthesizing bacterium Chlorobium tepidum has evolved a clever way to shield its light-harvesting processes from oxygen’s poisonous effects, using a quantum effect to shift its energy production line into low gear.

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