Monthly Archives: August 2020
In 1959, former Cornell physicist Richard Feynman delivered his famous lecture “There’s Plenty of Room at the Bottom,” in which he described the opportunity for shrinking technology, from machines to computer chips, to incredibly small sizes. Well, the bottom just got more crowded. A Cornell-led collaboration has created the first microscopic robots that incorporate semiconductor components, allowing them to be controlled – and made to walk – with standard electronic signals. These robots, roughly the size of paramecium, provide a template for building even more complex versions that utilize silicon-based intelligence, can be mass produced, and may someday travel through human tissue and blood.
The collaboration is led by Itai Cohen, professor of physics, Paul McEuen, the John A. Newman Professor of Physical Science – both in the College of Arts and Sciences – and their former postdoctoral researcher Marc Miskin, who is now an assistant professor at the University of Pennsylvania.
The walking robots are the latest iteration, and in many ways an evolution, of Cohen and McEuen’s previous nanoscale creations, from microscopic sensors to graphene-based origami machines. The new robots are about 5 microns thick (a micron is one-millionth of a meter), 40 microns wide and range from 40 to 70 microns in length. Each bot consists of a simple circuit made from silicon photovoltaics – which essentially functions as the torso and brain – and four electrochemical actuators that function as legs. As basic as the tiny machines may seem, creating the legs was an enormous feat.
“In the context of the robot’s brains, there’s a sense in which we’re just taking existing semiconductor technology and making it small and releasable,” said McEuen, who co-chairs the Nanoscale Science and Microsystems Engineering (NEXT Nano) Task Force, part of the provost’s Radical Collaboration initiative, and directs the Kavli Institute at Cornell for Nanoscale Science.
“But the legs did not exist before,” McEuen said. “There were no small, electrically activatable actuators that you could use. So we had to invent those and then combine them with the electronics.”
The team’s paper, “Electronically Integrated, Mass-Manufactured, Microscopic Robots,” has been published in Nature.
A product found in insect repellent can kill the strain of coronavirus that causes COVID-19, research by Britain’s defence laboratory has shown. Britain’s armed forces were issued with an insect repellent that contains a product called Citriodiol because it was believed it might offer a new layer of protection against COVID-19.
Citriodiol is already known to kill other types of coronavirus. Defence scientists subsequently conducted research to see whether it would provide a protective layer against COVID-19, with those results being released on Wednesday. The company that produces Citriodiol also believed it could offer protection against the novel coronavirus.
Jacqueline Watson, managing director of Citrefine International Ltd, said in April she would like the government to support a formal testing programme.
“What we can say is that we do feel there is a very good chance it could work against this virus but it does of course need to be thoroughly tested,” she said at the time.
The mosquito spray is not a sufficient protection on its own and is used by the military as an added layer along with face masks, hand washing and other techniques to prevent the spread of coronavirus.
The never-ending saga of machines outperforming humans has a new chapter. An AI algorithm has again beaten a human fighter pilot in a virtual dogfight. The contest was the finale of the U.S. military’s AlphaDogfight challenge, an effort to “demonstrate the feasibility of developing effective, intelligent autonomous agents capable of defeating adversary aircraft in a dogfight.
Last August, Defense Advanced Research Project Agency, or DARPA, selected eight teams ranging from large, traditional defense contractors like Lockheed Martin to small groups like Heron Systems to compete in a series of trials in November and January. In the final, on Thursday, Heron Systems emerged as the victor against the seven other teams after two days of old school dogfights, going after each other using nose-aimed guns only. Heron then faced off against a human fighter pilot sitting in a simulator and wearing a virtual reality helmet, and won five rounds to zero.
The other winner in Thursday’s event was deep reinforcement learning,wherein artificial intelligence algorithms get to try out a task in a virtual environment over and over again, sometimes very quickly, until they develop something like understanding. Deep reinforcement played a key role in Heron System’s agent, as well as Lockheed Martin’s, the runner up.
The Nordic nations are continuing to hold out against face masks even as most of the world either orders or recommends their use. Masks are a rare sight in supermarkets, on buses and along the streets in Stockholm, Copenhagen, Oslo, Helsinki and Reykjavik, and most who do wear them are tourists.
According to a recent survey by YouGov, only five to 10 per cent of respondents in the Nordic countries said they used a mask in public settings, a figure that has remained stable since the start of the crisis in March. At the same time, the corresponding figures have risen to between 70 and 80 per cent for most of the other 20 countries polled, including India and the United States.
This graph from YouGov shows the percentage of people in each country who say they are wearing a face mask in public places. The countries along the bottom are all Scandinavian nations, while the graph also shows how mask usage has dramatically increased in the UK
China, ground zero of the novel coronavirus outbreak, confirmed its first COVID-19 vaccine patent Sunday, according to state-affiliated media. “China has approved its first COVID19 vaccine patent, which has been developed by PLA infectious disease expert Chen Wei’s team. Earlier, the phase 2 trial of the vaccine candidate found that the vaccine is safe and induces an immune response,“ China Global Television Network (CGTN) said on Twitter. Citing data from clinical trials published in the Journal of the American Medical Association (JAMA), China’s state-run Xinhua News Agency reported earlier in the day that the COVID-19 vaccine candidate is “safe and generates an immune response.”
“ The COVID-19 vaccine candidate is “safe and generates an immune response,” reported China’s state-run Xinhua News Agency.
The research involved 320 “healthy volunteers” aged between 18 and 59, of which 96 participated in phase-1 clinical trials and 224 in phase-2 trials, it said. Xinhua said the results indicated that the vaccine effectively induced neutralizing antibodies in the volunteers and demonstrated good ability of a substance to trigger an immune response. On Saturday, Russia’s Health Ministry announced that the country has started production of its first COVID-19 vaccine, noting initial batches will be earmarked for immunizing doctors and health workers before going to the general public. Russia officially registered the world’s first coronavirus vaccine, developed by the Gamaleya Research Institute of Epidemiology and Microbiology, on Tuesday.
Biogen’s aducanumab is inching closer to an FDA decision. The Big Biotech, along with partner Eisai, announced that the FDA accepted its regulatory submission for aducanumab, its once-failed Alzheimer’s drug—with priority review to boot. The agency expects to decide the fate of the treatment by March 7. Along the way, it will hold an advisory committee meeting. It has not set a date for the meeting, but Jefferies analyst Michael Yee expects it sometime in the first quarter of 2021.
“The FDA’s acceptance of the aducanumab BLA with Priority Review is an important step in the path to potentially having a treatment that meaningfully changes the course of Alzheimer’s disease,” said Michel Vounatsos, Chief Executive Officer at Biogen.
How the FDA rules on aducanumab will show how far the FDA and its commissioner, Stephen Hahn, M.D., are willing to diverge from its established approval standards. Under U.S. law, companies need to show “substantial” evidence of effectiveness to win approval.
The wings of cicadas and dragonflies are natural bacteria killers, a phenomenon that has spurred researchers searching for ways to defeat drug-resistant superbugs. New anti-bacterial surfaces are being developed, featuring different nanopatterns that mimic the deadly action of insect wings, but scientists are only beginning to unravel the mysteries of how they work.
In a post published in Nature Reviews Microbiology, researchers have detailed exactly how these patterns destroy bacteria – stretching, slicing or tearing them apart. Lead author, RMIT University’s Distinguished Professor Elena Ivanova, said finding non-chemical ways of killing bacteria was critical, with more than 700,000 people dying each year due to drug-resistant bacterial infection.
The nanopillars on the surface of a dragonfly wing (magnified 20,000 times)
“Bacterial resistance to antibiotics is one of the greatest threats to global health and routine treatment of infection is becoming increasingly difficult,” Ivanova said. “When we look to nature for ideas, we find insects have evolved highly effective anti-bacterial systems. “If we can understand exactly how insect-inspired nanopatterns kill bacteria, we can be more precise in engineering these shapes to improve their effectiveness against infections. “Our ultimate goal is to develop low-cost and scaleable anti-bacterial surfaces for use in implants and in hospitals, to deliver powerful new weapons in the fight against deadly superbugs.”
The wings of cicadas and dragonflies are covered in tiny nanopillars, which were the first nanopatterns developed by scientists aiming to imitate their bactericidal effects. Since then, they’ve also precisely engineered other nanoshapes like sheets and wires, all designed to physically damage bacteria cells. Bacteria that land on these nanostructures find themselves pulled, stretched or sliced apart, rupturing the bacterial cell membrane and eventually killing them.
The new review for the first time categorises the different ways these surface nanopatterns deliver the necessary mechanical forces to burst the cell membrane. “Our synthetic biomimetic nanostructures vary substantially in their anti-bacterial performance and it’s not always clear why,” Ivanova explained. “We have also struggled to work out the optimal shape and dimensions of a particular nanopattern, to maximise its lethal power. “While the synthetic surfaces we’ve been developing take nature to the next level, even looking at dragonflies, for example, we see that different species have wings that are better at killing some bacteria than others. “When we examine the wings at the nanoscale, we see differences in the density, height and diameter of the nanopillars that cover the surfaces of these wings, so we know that getting the nanostructures right is key.”
It was just a couple of months ago that we heard about an implantable material that electrically stimulates bone cells, causing them to reproduce. Now, scientists have created a similar substance that utilizes magnetism. There are already a number of experimental materials that have a three-dimensional scaffolding-like microstructure, which simulates the structure of natural bone. After a piece of such a material has been implanted at a bone wound site, cells from the body’s adjacent bone tissue gradually migrate into it. Those cells reproduce over time, while the scaffolding simultaneously dissolves. Eventually, all that’s left is newly-grown bone, in the shape and location of the implant.
One of the challenges of the technology involves getting the bone cells to migrate and reproduce quickly. Although growth-boosting chemicals are often added to the material, scientists at the University of Connecticut took another approach with a scaffolding that they announced this June – it generates a weak electrical field in response to externally applied ultrasound pulses, and that field in turn prompts the bone cells to reproduce.
More recently, though, a team at Spain’s University of the Basque Country developed a material that instead incorporates magnetic nanoparticles. These are dispersed within a 3D matrix of a biocompatible silk-derived protein known as fibroin.
“When we apply a magnetic field, we bring about a response by these nanoparticles, which vibrate and thus deform the structure, they stretch it and transmit the mechanical stress to the cells,” says the lead scientist, Dr. José Luis Vilas-Vilela. In in vitro lab tests, that stress stimulated bone cells to reproduce much more quickly than would have otherwise been the case. In fact, the technology could conceivably be used to regrow more than just bone.
“We are developing various types of materials, stimuli and processes so that we can have the means to achieve the regeneration of different tissue,” says Vilas-Vilela. “In addition, the idea would be to use the stem cells of the patients themselves and be capable of differentiating them towards the type of cell we want to form the tissue with, be it bone, muscle, heart or whatever might be needed.”
The research – which also involved scientists from Portugal’s University of Minho and biotech firm BCMaterials – is described in a paper that was recently published in the journal Materialia.