Tag Archives: coronavirus pandemic
Under a winter’s snow cover on the outskirts of Quebec City in Canada, a high-tech greenhouse, set at a balmy 23 C, is growing row after row of a weed that could help end the coronavirus pandemic. It’s called Nicotiana benthamiana, a relative of the tobacco plant, native to Australia, and it is a key to biopharmaceutical company Medicago’s COVID-19 vaccine. Medicago is the leading Canadian-based contender to produce a vaccine, with an agreement to provide the federal government with 76 million doses if approved for use.
Medicago’s vaulting onto the mainstage could provide a breakthrough for vaccine science. It involves a new technology that’s rapid and nimble, and a vaccine that can be stored at normal fridge temperatures, of 2 C to 8 C, unlike the two other vaccines currently in circulation, which each require frozen or ultra-cold frozen storage. While it’s possible the company may emerge as the new wunderkind of the Canadian biotech sector, it wasn’t without adversity. For years, Medicago warned that Canada needed to prepare itself for a pandemic and lobbied government officials for funding to build a domestic manufacturing site for a vaccine. But Medicago didn’t get what it needed from the federal government until after the COVID-19 crisis struck. On top of that, in the middle of a pandemic, Medicago is restructuring. In July, it announced plans to distance itself from a significant shareholder, Philip Morris International, which owns about one-third of the company — a controversial association with Big Tobacco that has been the source of roadblocks and criticism. Then in December, the company replaced its president and CEO. But despite this, Medicago hasn’t lost sight of its goal: a vaccine.
In phase one of its clinical trials, 100 per cent of people who received its COVID-19 vaccine developed significant antibody responses with no severe adverse effects. Phase two clinical trials are currently wrapping up and phase three is expected to begin later this month. It will involve 30,000 people in 11 countries — including Canada — and will ultimately determine if the vaccine protects people from COVID-19. The vaccine requires two doses, 21 days apart, and if approved by Health Canada, could be in the arms of Canadians by the second half of this year.
Amid the coronavirus pandemic, people in developed countries are assured of ample supplies of clean water to wash their hands as often as needed to protect themselves from the virus. And yet, nearly a third of the world’s population is not even assured of clean water for drinking. University of Rochester researchers have now found a way to address this problem by using sunlight—a resource that everyone can access—to evaporate and purify contaminated water with greater than 100 percent efficiency.
How is this possible? In a paper in Nature Sustainability, researchers in the laboratory of Chunlei Guo, professor of optics, demonstrate how a burst of femtosecond laser pulses etch the surface of a normal sheet of aluminum into a superwicking (water-attracting), super energy–absorbing material. Using sunlight to boil has long been recognized as a way to eliminate microbial pathogens and reduce deaths from diarrheal infections. But boiling water does not eliminate heavy metals and other contaminants. Experiments by the lab show that their new method reduces the presence of all common contaminants, such as detergent, dyes, urine, heavy metals, and glycerin, to safe levels for drinking.
Solar-based water purification can greatly reduce contaminants because nearly all the impurities are left behind when the evaporating water becomes gaseous and then condenses and gets collected. The most common method of solar-based water evaporation is volume heating, in which a large volume of water is heated but only the top layer can evaporate. This is obviously inefficient, Guo says, because only a small fraction of the heating energy gets used. A more efficient approach, called interfacial heating, places floating, multilayered absorbing and wicking materials on top of the water, so that only water near the surface needs to be heated. But the available materials all have to float horizontally on top of the water and cannot face the sun directly. Furthermore, the available wicking materials become quickly clogged with contaminants left behind after evaporation, requiring frequent replacement of the materials.
The panel developed by the Guo lab avoids these inefficiencies by pulling a thin layer of water out of the reservoir and directly onto the solar absorber surface for heating and evaporation. “Moreover, because we use an open-grooved surface, it is very easy to clean by simply spraying it,” Guo says.
“The biggest advantage,” he adds, “is that the angle of the panels can be continuously adjusted to directly face the sun as it rises and then moves across the sky before setting” —maximizing energy absorption. “There was simply nothing else resembling what we can do here,” Guo says.