Articles from August 2021

There’s no need to don uncomfortable smartwatches or chest straps to monitor your heart if your comfy shirt can do a better job. That’s the idea behind “smart clothing” developed by a Rice University lab, which employed its conductive nanotube thread to weave functionality into regular apparel.

The Brown School of Engineering lab of chemical and biomolecular engineer Matteo Pasquali reported in the American Chemical Society journal Nano Letters that it sewed nanotube fibers into athletic wear to monitor the heart rate and take a continual electrocardiogram (EKG) of the wearer. The fibers are just as conductive as metal wires, but washable, comfortable and far less likely to break when a body is in motion, according to the researchers. On the whole, the shirt they enhanced was better at gathering data than a standard chest-strap monitor taking live measurements during experiments. When matched with commercial medical electrode monitors, the carbon nanotube shirt gave slightly better EKGs.

Rice University graduate student Lauren Taylor shows a shirt with carbon nanotube thread that provides constant monitoring of the wearer’s heart

“The shirt has to be snug against the chest,” said Rice graduate student Lauren Taylor, lead author of the study. “In future studies, we will focus on using denser patches of carbon nanotube threads so there’s more surface area to contact the skin.”

Source: https://news.rice.edu/

Inspired by the sticky substance that barnacles use to cling to rocks, MIT engineers have designed a strong, biocompatible glue that can seal injured tissues and stop bleeding. The new paste can adhere to surfaces even when they are covered with blood, and can form a tight seal within about 15 seconds of application. Such a glue could offer a much more effective way to treat traumatic injuries and to help control bleeding during surgery, the researchers say.

“We are solving an adhesion problem in a challenging environment, which is this wet, dynamic environment of human tissues. At the same time, we are trying to translate this fundamental knowledge into real products that can save lives,” says Xuanhe Zhao, a professor of mechanical engineering and civil and environmental engineering at MIT and one of the senior authors of the study. Finding ways to stop bleeding is a longstanding problem that has not been adequately solved, Zhao says. Sutures are commonly used to seal wounds, but putting stitches in place is a time-consuming process that usually isn’t possible for first responders to perform during an emergency situation. Among members of the military, blood loss is the leading cause of death following a traumatic injury, and among the general population, it is the second leading cause of death following a traumatic injury.

In recent years, some materials that can halt bleeding, also called hemostatic agents, have become commercially available. Many of these consist of patches that contain clotting factors, which help blood to clot on its own. However, these require several minutes to form a seal and don’t always work on wounds that are bleeding profusely. Zhao’s lab has been working to address this problem for several years

For their new tissue glue, the researchers once again drew inspiration from the natural world. This time, they focused their attention on the barnacle, a small crustacean that attaches itself to rocks, ship hulls, and even other animals such as whales. These surfaces are wet and often dirty — conditions that make adhesion difficult. “This caught our eye,” Yuk says. “It’s very interesting because to seal bleeding tissues, you have to fight with not only wetness but also the contamination from this outcoming blood. We found that this creature living in a marine environment is doing exactly the same thing that we have to do to deal with complicated bleeding issues.” The researchers’ analysis of barnacle glue revealed that it has a unique composition. The sticky protein molecules that help barnacles attach to surfaces are suspended in an oil that repels water and any contaminants found on the surface, allowing the adhesive proteins to attach firmly to the surface.

The MIT team decided to try to mimic this glue by adapting an adhesive they had previously developed. This sticky material consists of a polymer called poly(acrylic acid) embedded with an organic compound called an NHS ester, which provides adhesion, and chitosan, a sugar that strengthens the material. The researchers froze sheets of this material, ground it into microparticles, and then suspended those particles in medical grade silicone oil.

Christoph Nabzdyk, a cardiac anesthesiologist and critical care physician at the Mayo Clinic in Rochester, Minnesota, is also a senior author of the paper, which appears today in Nature Biomedical Engineering. MIT Research Scientist Hyunwoo Yuk and postdoc Jingjing Wu are the lead authors of the study.

Source: https://news.mit.edu/

Protein deposits in retina and brain appear to parallel possible neurodegeneration, an insight that might lead to easier, quicker detection. Amyloid plaques are protein deposits that collect between brain cells, hindering function and eventually leading to neuronal death. They are considered a hallmark of Alzheimer’s disease (AD), and the focus of multiple investigations designed to reduce or prevent their formation, including the nationwide A4 study.

But amyloid deposits may also occur in the retina of the eye, often in patients clinically diagnosed with AD, suggesting similar pathologies in both organs. In a small, cross-sectional study, a team of researchers, led by scientists at University of California San Diego School of Medicine, compared tests of retinal and brain amyloids in patients from the A4 study and another study (Longitudinal Evaluation of Amyloid Risk and Neurodegeneration) assessing neurodegeneration risk in persons with low levels of amyloid.

Like the proverbial “windows to the soul,” the researchers observed that the presence of retinal spots in the eyes correlated with brain scans showing higher levels of cerebral amyloid. The finding suggests that non-invasive retinal imaging may be useful as a biomarker for detecting early-stage AD risk.

Amyloid deposits tagged by curcumin fluoresce in a retinal scan.

“This was a small initial dataset from the screening visit. It involved eight patients,” said senior author Robert Rissman, PhD, professor of neurosciences at UC San Diego School of Medicine. “But these findings are encouraging because they suggest it may be possible to determine the onset, spread and morphology of AD — a preclinical diagnosis — using retinal imaging, rather than more difficult and costly brain scans. We look forward to seeing the results of additional timepoint retinal scans and the impact of solanezumab (a monoclonal antibody) on retinal imaging. Unfortunately we will need to wait to see and analyze these data when the A4 trial is completed.”

The findings published in the journal Alzheimer’s & Dementia.

https://ucsdnews.ucsd.edu/

The miniaturization of microelectronic sensor technology, microelectronic robots or intravascular implants is progressing rapidly. However, it also poses major challenges for research. One of the biggest is the development of tiny but efficient energy storage devices that enable the operation of autonomously working microsystems – in more and more smaller areas of the human body for example. In addition, these energy storage devices must be bio-compatible if they are to be used in the body at all. Now there is a prototype that combines these essential properties. The breakthrough was achieved by an international research team led by Prof. Dr. Oliver G. Schmidt, Professorship of Materials Systems for Nanoelectronics at Chemnitz University of Technology (Germany), initiator of the Center for Materials, Architectures and Integration of Nanomembranes (MAIN) at Chemnitz University of Technology and director at the Leibniz Institute for Solid State and Materials Research (IFW) Dresden. The Leibniz Institute of Polymer Research Dresden (IPF) was also involved in the study as a cooperation partner.

In the current issue of Nature Communications, the researchers report on the smallest microsupercapacitors to date, which already functions in (artificial) blood vessels and can be used as an energy source for a tiny sensor system to measure pH.

This storage system opens up possibilities for intravascular implants and microrobotic systems for next-generation biomedicine that could operate in hard-to-reach small spaces deep inside the human body. For example, real-time detection of blood pH can help predict early tumor growing. “It is extremely encouraging to see how new, extremely flexible, and adaptive microelectronics is making it into the miniaturized world of biological systems“, says research group leader Prof. Dr. Oliver G. Schmidt, who is extremely pleased with this research success.

“The architecture of our nano-bio supercapacitors offers the first potential solution to one of the biggest challenges – tiny integrated energy storage devices that enable the self-sufficient operation of multifunctional microsystems,” says Dr. Vineeth Kumar, researcher in Prof. Schmidt’s team and a research associate at the MAIN research center.

Ever smaller energy storage devices in the submillimeter range – so-called “nano-supercapacitors” (nBSC) – for even smaller microelectronic components are not only a major technical challenge, however. This is because, as a rule, these supercapacitors do not use biocompatible materials but, for example, corrosive electrolytes and quickly discharge themselves in the event of defects and contamination. Both aspects make them unsuitable for biomedical applications in the body. So-called “biosupercapacitors (BSCs)” offer a solution. They have two outstanding properties: they are fully biocompatible, which means that they can be used in body fluids such as blood and can be used for further medical studies.

In addition, biosupercapacitors can compensate for self-discharge behavior through bio-electrochemical reactions. In doing so, they even benefit from the body’s own reactions. This is because, in addition to typical charge storage reactions of a supercapacitor, redox enzymatic reactions and living cells naturally present in the blood increase the performance of the device by 40%.

Source: https://www.tu-chemnitz.de/

When it comes to the neural networks that power today’s artificial intelligence, sometimes the bigger they are, the smarter they are too. Recent leaps in machine understanding of language, for example, have hinged on building some of the most enormous AI models ever and stuffing them with huge gobs of text. A new cluster of computer chips could now help these networks grow to almost unimaginable size—and show whether going ever larger may unlock further AI advances, not only in language understanding, but perhaps also in areas like robotics and computer vision.

Cerebras Systems, a startup that has already built the world’s largest computer chip, has now developed technology that lets a cluster of those chips run AI models that are more than a hundred times bigger than the most gargantuan ones around today.

Cerebras says it can now run a neural network with 120 trillion connections, mathematical simulations of the interplay between biological neurons and synapses. The largest AI models in existence today have about a trillion connections, and they cost many millions of dollars to build and train. But Cerebras says its hardware will run calculations in about a 50th of the time of existing hardware. Its chip cluster, along with power and cooling requirements, presumably still won’t come cheap, but Cerberas at least claims its tech will be substantially more efficient.

“We built it with synthetic parameters,” says Andrew Feldman, founder and CEO of Cerebras, who will present details of the tech at a chip conference this week. “So we know we can, but we haven’t trained a model, because we’re infrastructure builders, and, well, there is no model yet” of that size, he adds.

Today, most AI programs are trained using GPUs, a type of chip originally designed for generating computer graphics but also well suited for the parallel processing that neural networks require. Large AI models are essentially divided up across dozens or hundreds of GPUs, connected using high-speed wiring.

GPUs still make sense for AI, but as models get larger and companies look for an edge, more specialized designs may find their niches. Recent advances and commercial interest have sparked a Cambrian explosion in new chip designs specialized for AI. The Cerebras chip is an intriguing part of that evolution. While normal semiconductor designers split a wafer into pieces to make individual chips, Cerebras packs in much more computational power by using the entire thing, having its many computational units, or cores, talk to each other more efficiently. A GPU typically has a few hundred cores, but Cerebras’s latest chip, called the Wafer Scale Engine Two (WSE-2), has 850,000 of them.

Source: https://www.wired.com/

Elon Musk and his companies have a commitment to fearless innovation. The incredible accomplishments that his companies have achieved include cutting-edge electric vehicles with Tesla, next-generation space-flight capabilities with SpaceX, and the development of critical brain-machine interfaces with Neuralink, to name a few.

Musk’s most recent announcement was on behalf of Tesla, and was yet another ode to fearless innovation. Last week, during Tesla’s much anticipated “AI Day,” an event meant to showcase the company’s revolutionary strides in artificial intelligence technology, Musk announced the next frontier for the company: developing the Tesla Bot, a “general purpose, bi-pedal, humanoid robot capable of performing tasks that are unsafe, repetitive or boring.”

Elon Musk described the project in detail: “Basically, if you think about what we’re doing right now with the cars, Tesla is arguably the world’s biggest robotics company…because our cars are like semi-sentient robots on wheels. With the full self-driving computer, the inference engine on the car (which will keep evolving, obviously), Dojo, and all the neural nets recognizing the world, understanding how to navigate through the world, it kind of makes sense to put that onto a humanoid form.” Musk described the purpose behind this bot, atleast initially: “it’s intended to be friendly of course, and navigate through a world built for humans and eliminate dangerous repetitive and boring tasks.” Musk also explained that a useful humanoid robot should be able to navigate the world without being explicitly trained step-by-step, and instead, should be able to perform advanced tasks with cognitive understanding of simple commands, such as“pick up groceries.”

Source: https://www.forbes.com/

Source: https://www.ssab.com/

‘Growing’ electronic components directly onto a semiconductor block avoids messy, noisy oxidation scattering that slows and impedes electronic operation. A UNSW (Australia) study out this month shows that the resulting high-mobility components are ideal candidates for high-frequency, ultra-small electronic devices, quantum dots, and for qubit applications in quantum computing.

Making computers faster requires ever-smaller transistors, with these electronic components now only a handful of nanometres in size. (There are around 12 billion transistors in the postage-stamp sized central chip of modern smartphones.)

However, in even smaller devices, the channel that the electrons flow through has to be very close to the interface between the semiconductor and the metallic gate used to turn the transistor on and off.  Unavoidable surface oxidation and other surface contaminants cause unwanted scattering of electrons flowing through the channel, and also lead to instabilities and noise that are particularly problematic for quantum devices.

“In the new work we create transistors in which an ultra-thin metal gate is grown as part of the semiconductor crystal, preventing problems associated with oxidation of the semiconductor surface,” says lead author Yonatan Ashlea Alava.

“We have demonstrated that this new design dramatically reduces unwanted effects from surface imperfections, and show that nanoscale quantum point contacts exhibit significantly lower noise than devices fabricated using conventional approaches,” says Yonatan, who is a FLEET PhD student.

“This new all single-crystal design will be ideal for making ultra-small electronic devices, quantum dots, and for qubit applications,” comments group leader Prof Alex Hamilton at UNSW.

Collaborating with wafer growers at Cambridge University, the team at UNSW Sydney showed that the problem associated with surface charge can be eliminated by growing an epitaxial aluminium gate before removing the wafer from the growth chamber.

“We confirmed the performance improvement via characterisation measurements in the lab at UNSW,” says co-author Dr Daisy Wang.

The high conductivity in ultra-shallow wafers, and the compatibility of the structure with reproducible nano-device fabrication, suggests that MBE-grown aluminium gated wafers are ideal candidates for making ultra-small electronic devices, quantum dots, and for qubit applications.

Source: https://www.fleet.org.au/

Today, the biotech company Moderna will start human trials for its HIV vaccine. Its HIV vaccine will be the first of its kind to use messenger RNA (mRNA), an approach that Moderna used in its effective COVID-19 vaccine.

The clinical trials will end sometime around spring 2023, according to the National Institutes of Health’s trial registry. They will involve 56 HIV-negative participants aged 18 to 56. The participants will be given one or two forms of mRNA that cause the body to form defenses against HIV infection.

In the past, HIV vaccines used inactivated forms of the virus. However, previous trials showed that these forms didn’t produce any immune responses. In fact, researchers canceled one trial in Thailand during the 2000s after inactivated forms of the virus were found to actually increase people’s risk of catching HIV rather than preventing infections.

Instead, the Moderna trials will contain one of two different types of mRNA: mRNA-1644 and mRNA-1644v2. These get the body’s cells to develop a “protein spike” on their surfaces. These spikes are similar to those embedded by HIV on a cell’s surface when it begins to infect cells to reproduce. When the body recognizes the presence of the mRNA spike, it begins producing antibodies to protect against infection. The mRNA may also allow scientists to make tweaks to the vaccine more easily.

“The mRNA platform makes it easy to develop vaccines against variants because it just requires an update to the coding sequences in the mRNA that code for the variant,” Rajesh Gandhi, MD, an infectious diseases physician at Massachusetts General Hospital and chair of the HIV Medicine Association, told the medical site Verywell. This is especially helpful for HIV since the virus is known for having mutated into at least 16 known variants.

Source: https://www.lgbtqnation.com/

On Aug. 8, 2021, an experiment at Lawrence Livermore National Laboratory’s (LLNL’s) National Ignition Facility (NIF) made a significant step toward ignition, achieving a yield of more than 1.3 megajoules (MJ). This advancement puts researchers at the threshold of fusion ignition, an important goal of the NIF, and opens access to a new experimental regime. The experiment was enabled by focusing laser light from NIF — the size of three football fields — onto a target the size of a BB that produces a hot-spot the diameter of a human hair, generating more than 10 quadrillion watts of fusion power for 100 trillionths of a second.

“These extraordinary results from NIF advance the science that NNSA depends on to modernize our nuclear weapons and production as well as open new avenues of research,” said Jill Hruby, DOE under secretary for Nuclear Security and NNSA administrator.

The central mission of NIF is to provide experimental insight and data for NNSA’s science-based Stockpile Stewardship Program. Experiments in pursuit of fusion ignition are an important part of this effort. They provide data in an important experimental regime that is extremely difficult to access, furthering our understanding of the fundamental processes of fusion ignition and burn and enhancing our simulation tools to support stockpile stewardship. Fusion ignition is also an important gateway to enable access to high fusion yields in the future.

“This result is a historic step forward for inertial confinement fusion research, opening a fundamentally new regime for exploration and the advancement of our critical national security missions. It is also a testament to the innovation, ingenuity, commitment and grit of this team and the many researchers in this field over the decades who have steadfastly pursued this goal,” said LLNL Director Kim Budil. “For me it demonstrates one of the most important roles of the national labs – our relentless commitment to tackling the biggest and most important scientific grand challenges and finding solutions where others might be dissuaded by the obstacles.”

While a full scientific interpretation of these results will occur through the peer-reviewed journal/conference process, initial analysis shows an 8X improvement over experiments conducted in spring 2021 and a 25X increase over NIF’s 2018 record yield.

Source: https://www.llnl.gov/