Archive for the ‘chemistry’ category

Oct 9, 2020

Nanoscale machines convert light into work

Posted by in categories: chemistry, nanotechnology, particle physics

“In previous work, the researchers discovered that when optical matter is exposed to circularly polarized light, it rotates as a rigid body in the direction opposite the polarization rotation. In other words, when the incident light rotates one way the optical matter array responds by spinning the other. This is a manifestation of “negative torque”. The researchers speculated that a machine could be developed based on this new phenomenon.

In the new work, the researchers created an optical matter machine that operates much like a mechanical machine based on interlocking gears. In such machines, when one gear is turned, a smaller interlocking gear will spin in the opposite direction. The optical matter machine uses circularly polarized light from a laser to create a nanoparticle array that acts like the larger gear by spinning in the optical field. This “optical matter gear” converts the circularly polarized light into orbital, or angular, momentum that influences a nearby probe particle to orbit the nanoparticle array (the gear) in the opposite direction.”

Researchers have developed a tiny new machine that converts laser light into work. These optically powered machines self-assemble and could be used for nanoscale manipulation of tiny cargo for applications such as nanofluidics and particle sorting.

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Oct 8, 2020

Engineers create nanoparticles that deliver gene-editing tools to specific tissues and organs

Posted by in categories: bioengineering, biotech/medical, chemistry, genetics, nanotechnology, neuroscience

One of the most remarkable recent advances in biomedical research has been the development of highly targeted gene-editing methods such as CRISPR that can add, remove, or change a gene within a cell with great precision. The method is already being tested or used for the treatment of patients with sickle cell anemia and cancers such as multiple myeloma and liposarcoma, and today, its creators Emmanuelle Charpentier and Jennifer Doudna received the Nobel Prize in chemistry.

While is remarkably precise in finding and altering genes, there is still no way to target treatment to specific locations in the body. The treatments tested so far involve removing or immune system T cells from the body to modify them, and then infusing them back into a patient to repopulate the bloodstream or reconstitute an immune response—an expensive and time-consuming process.

Building on the accomplishments of Charpentier and Doudna, Tufts researchers have for the first time devised a way to directly deliver gene-editing packages efficiently across the and into specific regions of the brain, into immune system cells, or to specific tissues and organs in mouse models. These applications could open up an entirely new line of strategy in the treatment of neurological conditions, as well as cancer, infectious disease, and autoimmune diseases.

Oct 7, 2020

‘Re-writing the code of life’: Nobel chemistry prize goes to genome editing pioneers

Posted by in categories: biotech/medical, chemistry, genetics

The genetic editing technique has contributed to new cancer therapies and has the potential to be used in curing inheritable diseases.

Two women were awarded the Nobel Prize in chemistry Wednesday for their pioneering work on genome editing, which has the life-saving potential to be used to cure genetic diseases.el Prize in chemistry Wednesday for their pioneering work on genome editing, which has the life-saving potential to be used to cure genetic diseases.el Prize in chemistry on Wednesday for developing a method for genome editing that could be used to cure many diseases.

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Oct 7, 2020

Nobel Prize in Chemistry Awarded to 2 Scientists for Work on Genome Editing

Posted by in categories: biotech/medical, chemistry

Emmanuelle Charpentier and Jennifer A. Doudna developed the Crispr tool, which can change the DNA of animals, plants and microorganisms with high precision.

Oct 7, 2020

French And U.S. Scientists Win Nobel In Chemistry For Work In Genome Editing

Posted by in categories: biotech/medical, chemistry

The Nobel Prize in Chemistry has been awarded to Emmanuelle Charpentier and Jennifer A. Doudna for the development of a method for genome editing.

Emmanuelle Charpentier (left), and Jennifer Doudna, are the sixth and seventh women to win the prestigious award.

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Oct 5, 2020

Inflight fiber printing toward array and 3D optoelectronic and sensing architectures

Posted by in categories: 3D printing, chemistry, nanotechnology, wearables

Scalability and device integration have been prevailing issues limiting our ability in harnessing the potential of small-diameter conducting fibers. We report inflight fiber printing (iFP), a one-step process that integrates conducting fiber production and fiber-to-circuit connection. Inorganic (silver) or organic {PEDOT: PSS [poly(3,4-ethylenedioxythiophene) polystyrene sulfonate]} fibers with 1- to 3-μm diameters are fabricated, with the fiber arrays exhibiting more than 95% transmittance (350 to 750 nm). The high surface area–to–volume ratio, permissiveness, and transparency of the fiber arrays were exploited to construct sensing and optoelectronic architectures. We show the PEDOT: PSS fibers as a cell-interfaced impedimetric sensor, a three-dimensional (3D) moisture flow sensor, and noncontact, wearable/portable respiratory sensors. The capability to design suspended fibers, networks of homo cross-junctions and hetero cross-junctions, and coupling iFP fibers with 3D-printed parts paves the way to additive manufacturing of fiber-based 3D devices with multilatitude functions and superior spatiotemporal resolution, beyond conventional film-based device architectures.

Small-diameter conducting fibers have unique morphological, mechanical, and optical properties such as high aspect ratio, low bending stiffness, directionality, and transparency that set them apart from other classes of conducting, film-based micro/nano structures (1–3). Orderly assembling of thin conducting fibers into an array or three-dimensional (3D) structures upscales their functional performance for device coupling. Developing new strategies to control rapid synthesis, patterning, and integration of these conducting elements into a device architecture could mark an important step in enabling new device functions and electronic designs (4, 5). To date, conducting micro/nanoscaled fibers have been produced and assembled in a number of ways, from transferring of chemically grown nanofibers/wires (6, 7), writing electrohydrodynamically deposited lines (8, 9), to drawing ultralong fibers (10, 11), wet spinning of fibers (12–14), and 2D/3D direct printing (15–18).

Oct 5, 2020

Giant electrochemical actuation in a nanoporous silicon-polypyrrole hybrid material

Posted by in categories: biological, chemistry, computing, cyborgs, sustainability

The absence of piezoelectricity in silicon makes direct electromechanical applications of this mainstream semiconductor impossible. Integrated electrical control of the silicon mechanics, however, would open up new perspectives for on-chip actuorics. Here, we combine wafer-scale nanoporosity in single-crystalline silicon with polymerization of an artificial muscle material inside pore space to synthesize a composite that shows macroscopic electrostrain in aqueous electrolyte. The voltage-strain coupling is three orders of magnitude larger than the best-performing ceramics in terms of piezoelectric actuation. We trace this huge electroactuation to the concerted action of 100 billions of nanopores per square centimeter cross section and to potential-dependent pressures of up to 150 atmospheres at the single-pore scale. The exceptionally small operation voltages (0.4 to 0.9 volts), along with the sustainable and biocompatible base materials, make this hybrid promising for bioactuator applications.

An electrochemical change in the oxidation state of polypyrrole (PPy) can increase or decrease the number of delocalized charges in its polymer backbone (1). Immersed in an electrolyte, this is also accompanied by a reversible counter-ion uptake or expulsion and thus with a marcroscopic contraction or swelling under electrical potential control, making PPy one of the most used artificial muscle materials (15).

Here, we combine this actuator polymer with the three-dimensional (3D) scaffold structure of nanoporous silicon (68) to design, similarly as found in many multiscale biological composites in nature (9), a material with embedded electrochemical actuation that consists of a few light and abundant elemental constituents (i.e., H, C, N, O, Si, and Cl).

Oct 4, 2020

A New Chemical ‘Tree of The Origins of Life’ Reveals Our Possible Molecular Evolution

Posted by in categories: biological, chemistry, evolution

One of the greatest mysteries in our Universe is right here on our own doorstep. No, closer — it’s in every fibre of our being.

At least 3.7 billion years ago, a few simple molecules worked together to create something new. Then a few more. And, somehow, these snowballing combinations eventually produced the first very basic living organisms that would evolve and branch out to become all life on Earth.

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Oct 4, 2020

DARPA’s SIGMA Program Transitions to Protect Major U.S. Metropolitan Region

Posted by in categories: biological, biotech/medical, chemistry, terrorism, transportation

On a blustery winter day last December, a car carrying radioactive material approached one of the Port Authority of New York and New Jersey’s major transportation hubs. As the car got closer, an alarm flashed and sounded on a large monitor in the police operations center, identifying on a digital map the exact location of the vehicle and the specific radioactive isotope radiating from the car – Cesium-137. Within minutes, officers in the Port Authority Police Department – equipped with vehicle-mounted and pocket-sized radiation sensors displaying the same real-time digital map – tracked the vehicle and apprehended the suspects in a parking lot. Thankfully, the potential terrorists and radiation-emitting isotope were not a threat, as the scenario was only a drill.

The December exercise marked the capstone for DARPA’s SIGMA program, culminating a five-year effort to develop and deploy an automated, high-performance, networked radiation detection capability for counterterrorism and continuous city-to-region scale radiological and nuclear threat monitoring. The transition of the radiation-detection system took place prior to the coronavirus disease (COVID-19) pandemic. In the eight months since the SIGMA transition, DARPA has been developing and testing additional sensors under its SIGMA+ effort to detect chemical, biological and explosive threats as well.

“We want to thank the Port Authority for their outstanding support throughout the SIGMA program and their continued support as we test SIGMA+ sensors,” said Mark Wrobel, DARPA program manager in the Defense Sciences Office. “Being able to test and refine the system in the country’s largest metropolitan region was invaluable in taking SIGMA from a research project to an operationally deployed system in just five years.”

Oct 3, 2020

The role of solid state chemistry in the development of metal-ion batteries

Posted by in categories: chemistry, particle physics, sustainability

Professors from the Skoltech Center for Energy Science and Technology (CEST), Lomonosov Moscow State University and College de France shared their vision on the importance of solid state chemistry in advancements currently awaited from contemporary and prospective metal-ion batteries. The opinion was contributed as an invited review to Nature Communications.

Metal-ion batteries are the main drivers enabling a smooth transfer to renewables and green energy for a sustainable planet. The artfully designed electrode materials have greatly contributed to the development of high-performance Li-ion batteries that was eventually hallmarked by the 2019 Nobel Prize, which had signified the role solid state chemistry. Targeted design of novel metal-ion battery materials to bring the technology to the next level clearly stands as a great challenge for today’s chemistry community.

The individual properties of atoms and ions encoded in the Periodic Table along with the fundamental trends and principles multiplied by further levels of complexity constitute multitude of possible combinations for scientists to find new battery electrodes. Obviously, the researchers need solid guidelines while searching through this huge parameter space for the best chemical combinations and structures.

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