Monthly Archives: May 2020
Both viruses remove marker molecules on the surface of an infected cell that are used by the immune system to identify invaders, the researchers said in a non-peer reviewed paper posted on preprint website bioRxiv.org on Sunday. They warned that this commonality could mean Sars-CoV-2, the clinical name for the virus, could be around for some time, like HIV.
Virologist Zhang Hui and a team from Sun Yat-sen University in Guangzhou also said their discovery added weight to clinical observations that the coronavirus was showing “some characteristics of viruses causing chronic infection”.
Their research involved collecting killer T cells from five patients who had recently recovered from Covid-19, the disease caused by the virus. Those immune cells are generated by people after they are infected with Sars-CoV-2 – their job is to find and destroy the virus.
The molecule is an identification tag usually present in the membrane of a healthy cell, or in sick cells infected by other coronaviruses such as severe acute respiratory syndrome, or Sars. It changes with infections, alerting the immune system whether a cell is healthy or infected by a virus. HIV uses the same strategy – MHC molecules are also absent in cells infected with that virus. “In contrast, Sars does not make use of this function,” Zhang said.
The coronavirus removes these markers by producing a protein known as ORF8, which binds with MHC molecules, then pulls them inside the infected cell and destroys them, the researchers said. ORF8 is known to play an important role in viral replication, and most commercial test kits target this gene to detect viral loads in nose or oral swabs.
While drugs being used to treat Covid-19 patients mainly targeted enzymes or structural proteins needed for viral replication, Zhang and his team suggested compounds be developed “specifically targeting the impairment of MHC by ORF8, and therefore enhancing immune surveillance for Sars-CoV-2 infection”.
Early detection of tumors is extremely important in treating cancer. A new technique developed by researchers at the University of California, Davis, (UC Davis) offers a significant advance in using magnetic resonance imaging (MRI) to pick out even very small tumors from normal tissue.
Chemical probes that produce a signal on magnetic resonance imaging, or MRI, can be used to target and image tumors. The new research is based on a phenomenon called magnetic resonance tuning that occurs between two nanoscale magnetic elements. One acts to enhance the signal, and the other quenches it. Previous studies have shown that quenching depends on the distance between the magnetic elements. This opens new possibilities for noninvasive and sensitive investigation of a variety of biological processes by MRI.
The UC Davis team created a probe that generates two magnetic resonance signals that suppress each other until they reach the target, at which point they both increase contrast between the tumor and surrounding tissue. They call this two-way magnetic resonance tuning, or TMRET. Combined with specially developed imaging analysis software, the double signal enabled researchers to pick out brain tumors in a mouse model with greatly increased sensitivity.
“It’s a significant advance,” said senior author Yuanpei Li, associate professor of biochemistry and molecular medicine at the UC Davis School of Medicine and Comprehensive Cancer Center. “This could help detect very small early-stage tumors.”
The probe developed by the UC Davis team contains two components: nanoparticles of superparamagnetic iron oxide, or SPIO, and pheophorbide a–paramagnetic manganese, or P-Mn, packaged together in a lipid envelope. SPIO and P-Mn both give strong, separate signals on MRI, but as long as they are physically close together those signals tend to cancel each other out, or quench. When the particles enter tumor tissue, the fatty envelope breaks down, SPIO and P-Mn separate, and both signals appear.
Li’s laboratory focuses on the chemistry of MRI probes and developed a method to process the data and reconstruct images, which they call double-contrast enhanced subtraction imaging, or DESI. But for expertise in the physical mechanisms, they reached out to professors Kai Liu and Nicholas Curro at the UC Davis Department of Physics (Liu is now at Georgetown University). The physicists helped elucidate the mechanism of the TMRET method and refine the technique.
The researchers tested the method in cultures of brain and prostate cancer cells and in mice. For most MRI probes, the signal from the tumor is up to twice as strong as from normal tissue – a “tumor to normal ratio” of 2 or less. Using the new dual-contrast nanoprobe, Li and colleagues could get a tumor-to-normal ratio as high as 10.
The findings are published in the journal Nature Nanotechnology.
The world’s first 3D artificial eyeball — capable of outperforming the human eye in some ways — may help droves of people who are partially or fully blind in as little as five years, according to experts.
Researchers from Hong Kong University of Science and Technology have devised an electrochemical eye whose structure and performance mimic those of the ones humans are born with.
“The device design has a high degree of structural similarity to a human eye with the potential to achieve high imaging resolution when individual nanowires are electrically addressed,” researchers of Hong Kong University of Science and Technology wrote in a paper published in the journal Nature.
The device converts images through tiny sensors that mirror the light–detecting photoreceptor cells in a human eye, The Sun reported. Those sensors reside within a membrane made of aluminum and tungsten which is shaped into a half sphere for the purpose of mimicking a human retina.
Electric car maker Tesla Inc (TSLA.O) plans to introduce a new low-cost, long-life battery in its Model 3 sedan in China later this year or early next that it expects will bring the cost of electric vehicles in line with gasoline models, and allow EV batteries to have second and third lives in the electric power grid.
For months, Tesla Chief Executive Elon Musk has been teasing investors, and rivals, with promises to reveal significant advances in battery technology during a “Battery Day” in late May.
New, low-cost batteries designed to last for a million miles of use and enable electric Teslas to sell profitably for the same price or less than a gasoline vehicle are just part of Musk’s agenda, people familiar with the plans said.
With a global fleet of more than 1 million electric vehicles that are capable of connecting to and sharing power with the grid, Tesla’s goal is to achieve the status of a power company, competing with such traditional energy providers as Pacific Gas & Electric (PCG_pa.A) and Tokyo Electric Power (9501.T), those sources said. The new “million mile” battery at the center of Tesla’s strategy was jointly developed with China’s Contemporary Amperex Technology Ltd (CATL) (300750.SZ) and deploys technology developed by Tesla in collaboration with a team of academic battery experts recruited by Musk, three people familiar with the effort said.
Morgan Stanley, which recently named Moderna Inc (NASDAQ: MRNA) as one of the likeliest candidates to succeed in the coronavirus vaccine race, reviewed the interim Phase 1 data released by the company Monday. The Moderna Analyst Matthew Harrison maintained an Overweight rating on Moderna shares and increased the price target from $37 to $90.
Moderna’s ability to scale coupled with promising early results positions it well to compete in the market, Harrison said in a Wednesday note. The analyst expects Moderna to sell about 1.5 billion doses of the vaccine during the pandemic period and 150 million annual doses during the endemic period.
“Given the promising early results, we risk-adjust our estimates assuming a 65% probability of success, slightly higher than the ~56% of typical PhII vaccine candidates.”
Breaking down Morgan Stanley’s valuation model, Harrison said $23 of the firm’s price target increase is attributable to the coronavirus vaccine. $12 per share is assigned to year-end 2021 cash and lower dilution; $11 per share is attributed to the higher chance of success across the vaccine platform and $7 is for the increase in platform value, the analyst said. Morgan Stanley expects full Phase 1 data to be available by the time the Phase 3 study starts in July, and projects the Phase 2 data will be released in the fall of 2020.
Interim Phase 3 data is likely to be available as early as the end of the year, Harrison said.
One of the largest NHS trusts in England is using Microsoft HoloLens on its Covid-19 wards to keep doctors safe as they help patients with the virus. Staff at Imperial College Healthcare NHS Trust are wearing the mixed-reality headset as they work on the frontline in the most high-risk area of some of London’s busiest hospitals. HoloLens with Dynamics 365 Remote Assist uses Microsoft Teams to send a secure live video-feed to a computer screen in a nearby room, allowing healthcare teams to see everything the doctor treating Covid-19 patients can see, while remaining at a safe distance.
Imperial College Healthcare NHS Trust, which includes Charing Cross Hospital, Hammersmith Hospital and St Mary’s Hospital, says using HoloLens has led to a fall in the amount of time staff are spending in high-risk areas of up to 83%. It is also significantly reducing the amount of personal protective equipment (PPE) being used, as only the doctor wearing the headset has to dress in PPE. Early estimates that using HoloLens is saving up to 700 items of PPE per ward, per week.
“In March, we had a hospital full of Covid-19 patients. Doctors, nurses and allied healthcare professionals providing ward care had a high risk of exposure to the virus and many became ill. Protecting staff was a major motivating factor for this work, but so was protecting patients. If our staff are ill they can transmit disease and they are unable to provide expert medical care to those who needed it most, said James Kinross, a consultant surgeon at Imperial College Healthcare? Kinross has been using HoloLens for many years at the hospital. “In one week our hospital trust switched from being a place that delivered acute, elective care and planned treatment into a giant intensive care unit. We weren’t just trying to restructure an entire building, we were trying to redeploy and retrain our staff, while at the same time we had to cope with an ever-growing number of very sick people. “We needed an innovative solution. I’ve used HoloLens before in surgery and we quickly realised it had a unique role to play because we could take advantage of its hands-free telemedicine capabilities. Most importantly, it could be used while wearing PPE. It solved a major problem for us during a crisis, by allowing us to keep treating very ill patients while limiting our exposure to a deadly virus. Not only that, it reduced our PPE consumption and significantly improved the efficiency of our ward rounds.”
Rather than put users in a fully computer-generated world, as virtual reality does, HoloLens allows users to place 3D digital models in the room alongside them and interact with them using gestures, gaze and voice.
Coronavirus could “burn out naturally” so a vaccine is no longer needed, a former World Health Organisation director has claimed, as the British Government announces it is dedicating more than £90m to a dedicated inoculation development centre.
Professor Karol Sikora, an oncologist and chief medical officer at Rutherford Health, said it is likely the British public has more immunity than previously thought and Covid-19 could end up “petering out by itself”.
“There is a real chance that the virus will burn out naturally before any vaccine is developed,” he wrote on his social media profile yesterday. “We are seeing a roughly similar pattern everywhere – I suspect we have more immunity than estimated. We need to keep slowing the virus, but it could be petering out by itself.”
Allowing users to create objects from simple toys to custom prosthetic parts, plastics are a popular 3D printing material. But these printed parts are mechanically weak — a flaw caused by the imperfect bonding between the individual printed layers that make up the 3D part. Researchers at Texas A&M University, in collaboration with scientists in the company Essentium, Inc. have now developed the technology needed to overcome 3D printing’s “weak spot.” By integrating plasma science and carbon nanotube technology into standard 3D printing, the researchers welded adjacent printed layers more effectively, increasing the overall reliability of the final part.
Texas A&M and Essentium researchers have developed the technology to weld adjacent 3D printed layers more effectively, increasing the reliability of the final product
“Finding a way to remedy the inadequate bonding between printed layers has been an ongoing quest in the 3D printing field,” said Micah Green, associate professor in the Artie McFerrin Department of Chemical Engineering. “We have now developed a sophisticated technology that can bolster welding between these layers all while printing the 3D part.”
Plastics are commonly used for extrusion 3D printing, known technically as fused-deposition modeling. In this technique, molten plastic is squeezed out of a nozzle that prints parts layer by layer. As the printed layers cool, they fuse to one another to create the final 3D part. However, studies show that these layers join imperfectly; printed parts are weaker than identical parts made by injection molding where melted plastics simply assume the shape of a preset mold upon cooling. To join these interfaces more thoroughly, additional heating is required, but heating printed parts using something akin to an oven has a major drawback. “If you put something in an oven, it’s going to heat everything, so a 3D-printed part can warp and melt, losing its shape,” Green said. “What we really needed was some way to heat only the interfaces between printed layers and not the whole part.”
To promote inter-layer bonding, the team turned to carbon nanotubes. Since these carbon particles heat in response to electrical currents, the researchers coated the surface of each printed layer with these nanomaterials. Similar to the heating effect of microwaves on food, the team found that these carbon nanotube coatings can be heated using electric currents, allowing the printed layers to bond together.
To apply electricity as the object is being printed, the currents must overcome a tiny space of air between the printhead and the 3D part. One option to bridge this air gap is to use metal electrodes that directly touch the printed part, but Green said this contact can introduce inadvertent damage to the part.
The team collaborated with David Staack, associate professor in the J. Mike Walker ‘66 Department of Mechanical Engineering, to generate a beam of charged air particles, or plasma, that could carry an electrical charge to the surface of the printed part. This technique allowed electric currents to pass through the printed part, heating the nanotubes and welding the layers together.
With the plasma technology and the carbon nanotube-coated thermoplastic material in place, Texas A&M and Essentium researchers added both these components to conventional 3D printers. When the researchers tested the strength of 3D printed parts using their new technology, they found that their strength was comparable to injection-molded parts.
“The holy grail of 3D printing has been to get the strength of the 3D-printed part to match that of a molded part,” Green said. “In this study, we have successfully used localized heating to strengthen 3D-printed parts so that their mechanical properties now rival those of molded parts. With our technology, users can now print a custom part, like an individually tailored prosthetic, and this heat-treated part will be much stronger than before.”
The findings have been published in the journal Nano Letters.