In an article published in the April 8 issue of Nature, the National Institutes of Health’s Somatic Cell Gene Editing Consortium provided a detailed update on the progress of their nationwide effort to develop safer and more effective methods to edit the genomes of disease-relevant somatic cells and reduce the burden of disease caused by genetic changes.
Gene editing allows scientists to modify sections of an organism’s DNA and is considered a promising treatment for a number of genetic diseases. There have been numerous advances in the laboratory over the last few decades, but there are still many challenges to overcome before gene editing can be widely used in the patient population. Launched in 2018, the Somatic Cell Gene Editing Consortium (SCGE) has brought together some of the leading researchers in the field to advance discovery and accelerate the translation of somatic gene editing advances in the lab to the clinical setting.
Over six years, the NIH will allocate approximately $190 million to SCGE to realize gene editing’s potential. The end result will be a freely available toolkit that will provide the biomedical research community with rigorously evaluated information about genome editors and methods for delivering and tracking gene editing molecules.
“NIH realized it was important for all of us who are investigating gene editing to work together toward a common goal,” said Carnegie Mellon University Professor of Chemistry Danith Ly who joined the consortium in 2019. “We’re designing molecules that can go into the cell and we’re cataloging each and every one. What we’ll end up with is a very valuable, rigorously evaluated resource for those who want to bring gene editing to patients.”
While much of the consortium’s work focuses on CRISPER-Cas related systems, the SCGE points out that it’s important to continue to develop other systems. They specifically single out the peptide nucleic acid-based gene editing technique developed by Carnegie Mellon’s Ly and Yale University’s Peter Glazer.
“Although there is a significant focus on CRISPR-Cas related systems within the SCGE, it is crucial to continue to explore alternate systems, in part because they may differ in both their potential for delivery and their biological or immunological responses,” the consortium wrote in Nature.
While CRISPR-Cas edits genes in cells that have been removed from the body, Ly and Glazer’s peptide nucleic acid (PNA) system is administered intravenously and edits cells in vivo. Using nanoparticles, a PNA molecule paired with a donor strand of DNA is delivered directly to a malfunctioning gene. Ly, a leading researcher in synthetic nucleic acid technology, has programmed PNA molecules to open double stranded DNA at the site of a targeted mutation. The donor DNA from the complex binds to the cell’s faulty DNA and triggers the DNA’s innate repair mechanisms to edit the gene. The team has used the technique to cure beta thalassemia in adult mice and in fetal mice in utero.
The PNA gene editing system doesn’t have the high-yield of CRISPER-Cas systems, but it does have the advantage of being less likely to make off-target modifications. According to Ly, that means their technique might be better for genetic diseases that only need to have a small percentage of cells corrected to make a therapeutic difference. For example, in the beta thalassemia studies, Ly and Glazer found that editing only six to seven percent of cells was curative.
Ly and Glazer plan to further refine and improve their technique through their participation in SCGE, and they look forward to sharing their results with the consortium and the greater biomedical community.
Story Source:
Materials provided by Carnegie Mellon University. Original written by Jocelyn Duffy. Note: Content may be edited for style and length.

The B.1.1.7 variant, first identified in Britain, is now the source of most new coronavirus infections in the United States, the director of the Centers for Disease Control and Prevention said.WASHINGTON — A highly infectious variant of the coronavirus that was first identified in Britain has become the most common source of new infections in the United States, the director of the Centers for Disease Control and Prevention said on Wednesday. The worrisome development comes as officials and scientists warn of a possible fourth surge of infections.Federal health officials said in January that the B.1.1.7 variant, which began surging in Britain in December and has since slammed Europe, could become the dominant source of coronavirus infections in the United States, leading to a huge increase in cases and deaths.At that point, new cases, hospitalizations and deaths were at an all-time high. From that peak, the numbers all declined until late February, according to a New York Times database. After several weeks at a plateau, new cases and hospitalizations are increasing again. The average number of new cases in the country has reached nearly 65,000 a day as of Tuesday, concentrated mostly in metro areas in Michigan as well as in the New York City region. That is an increase of 19 percent compared with the figure two weeks ago.Dr. Rochelle Walensky, the C.D.C. director, who warned last week that she felt a recurring sense of “impending doom,” said on Wednesday that 52 of the agency’s 64 jurisdictions — which include states, some major cities and territories — are now reporting cases of these so-called “variants of concern,” including B.1.1.7.The number of deaths, however, continue to decline — potentially a sign that mass vaccinations are beginning to protect older Americans and other highly vulnerable populations.“These trends are pointing to two clear truths,” Dr. Walensky said. “One, the virus still has hold on us, infecting people and putting them in harm’s way, and we need to remain vigilant. And two, we need to continue to accelerate our vaccination efforts and to take the individual responsibility to get vaccinated when we can.”B.1.1.7, the first variant to come to widespread attention, is about 60 percent more contagious and 67 percent more deadly than the original form of the coronavirus, according to the most recent estimates. The C.D.C. has also been tracking the spread of other variants, such as B.1.351, first found in South Africa, and P.1, which was first identified in Brazil.The percentage of cases caused by variants is clearly increasing. Helix, a lab testing company, has tracked the relentless increase of B.1.1.7 since the beginning of the year. As of April 3, it estimated that the variant made up 58.9 percent of all new tests.That variant has been found to be most prevalent in Michigan, Florida, Colorado, California, Minnesota and Massachusetts, according to the C.D.C. Until recently, the variant’s rise was somewhat camouflaged by falling infection rates over all, leading some political leaders to relax restrictions on indoor dining, social distancing and other measures.As cases fell, restive Americans headed back to school and work, against the warnings of some scientists.Federal health officials are tracking reports of increasing cases associated with day care centers and youth sports, and hospitals are seeing more younger adults — people in their 30s and 40s who are admitted with “severe disease,” Dr. Walensky said.It is difficult for scientists to say exactly how much of the current patterns of infection are because of the growing frequency of B.1.1.7.“It’s muddled by the reopening that’s going on and changes in behavior,” said Dr. Adam Lauring, a virologist at the University of Michigan.But he noted that people were becoming less cautious at a time when they should be raising their guard against a more contagious variant. “It’s worrisome,” he said.At the same time, the United States is currently vaccinating an average of about three million people a day, and states have rushed to make all adults eligible. The C.D.C. reported on Wednesday that almost 110 million people had received at least one dose of a Covid-19 vaccine, including about 64.4 million people who have been fully vaccinated. New Mexico, South Dakota, Rhode Island and Alaska are leading the states, with about 25 percent of their total populations fully vaccinated.Scientists hope that vaccination will blunt any potential fourth surge.On Tuesday, President Biden moved up his vaccination timetable by two weeks, calling states to make every American adult eligible by April 19. All states have already met or expect to beat this goal after he initially asked that they do so by May 1.The B.1.1.7 variant first arrived in the United States last year. In February, a study that analyzed half a million coronavirus tests and hundreds of genomes predicted that this variant could become predominant in the country in a month. At that time, the C.D.C. was struggling to sequence the new variants, which made it difficult to track them.But those efforts have substantially improved in recent weeks and will continue to grow, in large part because of $1.75 billion in funds for genomic sequencing in the stimulus package that Mr. Biden signed into law last month. By contrast, Britain, which has a more centralized health care system, began a highly promoted sequencing program last year that allowed it to track the spread of the B.1.1.7 variant.“We knew this was going to happen: This variant is a lot more transmissible, much more infectious than the parent strain, and that obviously has implications,” said Dr. Carlos del Rio, a professor of medicine and an infectious disease expert at Emory University. In addition to spreading more efficiently, he said, the B.1.1.7 strain appears to cause more severe disease, “so that gives you a double whammy.”Perhaps even more troubling is the emergence of the virulent P.1 variant in North America. First identified in Brazil, it has become the dominant variant in that country, helping to drive its hospitals to the breaking point. In Canada, the P.1 variant emerged as a cluster in Ontario, then shut down the Whistler ski resort in British Columbia. On Wednesday, the National Hockey League’s Vancouver Canucks said at least 21 players and four staff members had been infected with the coronavirus.“This is a stark reminder of how quickly the virus can spread and its serious impact, even among healthy, young athletes,” the team’s doctor, Jim Bovard, said in a statement.

The B.1.1.7 variant, first identified in Britain, is now the source of most new coronavirus infections in the United States, the director of the Centers for Disease Control and Prevention said.WASHINGTON — A highly infectious variant of the coronavirus that was first identified in Britain has become the most common source of new infections in the United States, the director of the Centers for Disease Control and Prevention said on Wednesday. The worrisome development comes as officials and scientists warn of a possible fourth surge of infections.Federal health officials said in January that the B.1.1.7 variant, which began surging in Britain in December and has since slammed Europe, could become the dominant source of coronavirus infections in the United States, leading to a huge increase in cases and deaths.At that point, new cases, hospitalizations and deaths were at an all-time high. From that peak, the numbers all declined until late February, according to a New York Times database. After several weeks at a plateau, new cases and hospitalizations are increasing again. The average number of new cases in the country has reached more than 62,000 a day as of Tuesday, concentrated mostly in metro areas in Michigan as well as in the New York City region. That is an increase of 19 percent compared with the figure two weeks ago.Dr. Rochelle Walensky, the C.D.C. director, who warned last week that she felt a recurring sense of “impending doom,” said on Wednesday that 52 of the agency’s 64 jurisdictions — which include states, some major cities and territories — are now reporting cases of these so-called “variants of concern,” including B.1.1.7.The number of deaths, however, continue to decline — potentially a sign that mass vaccinations are beginning to protect older Americans and other highly vulnerable populations.“These trends are pointing to two clear truths,” Dr. Walensky said. “One, the virus still has hold on us, infecting people and putting them in harm’s way, and we need to remain vigilant. And two, we need to continue to accelerate our vaccination efforts and to take the individual responsibility to get vaccinated when we can.”B.1.1.7, the first variant to come to widespread attention, is about 60 percent more contagious and 67 percent more deadly than the original form of the coronavirus, according to the most recent estimates. The C.D.C. has also been tracking the spread of other variants, such as B.1.351, first found in South Africa, and P.1, which was first identified in Brazil.The percentage of cases caused by variants is clearly increasing. Helix, a lab testing company, has tracked the relentless increase of B.1.1.7 since the beginning of the year. As of April 3, it estimated that the variant made up 58.9 percent of all new tests.That variant has been found to be most prevalent in Michigan, Florida, Colorado, California, Minnesota and Massachusetts, according to the C.D.C. Until recently, the variant’s rise was somewhat camouflaged by falling infection rates over all, leading some political leaders to relax restrictions on indoor dining, social distancing and other measures.As cases fell, restive Americans headed back to school and work, against the warnings of some scientists.Federal health officials are tracking reports of increasing cases associated with day care centers and youth sports, and hospitals are seeing more younger adults — people in their 30s and 40s who are admitted with “severe disease,” Dr. Walensky said.It is difficult for scientists to say exactly how much of the current patterns of infection are because of the growing frequency of B.1.1.7.“It’s muddled by the reopening that’s going on and changes in behavior,” said Dr. Adam Lauring, a virologist at the University of Michigan.But he noted that people were becoming less cautious at a time when they should be raising their guard against a more contagious variant. “It’s worrisome,” he said.At the same time, the United States is currently vaccinating an average of about three million people a day, and states have rushed to make all adults eligible. The C.D.C. reported on Tuesday that about 108.3 million people had received at least one dose of a Covid-19 vaccine, including about 63 million people who have been fully vaccinated. New Mexico, South Dakota, Rhode Island and Alaska are leading the states, with about 25 percent of their total populations fully vaccinated.Scientists hope that vaccination will blunt any potential fourth surge.On Tuesday, President Biden moved up his vaccination timetable by two weeks, calling states to make every American adult eligible by April 19. Nearly all states have already met or expect to beat this goal after he initially asked that they do so by May 1.The B.1.1.7 variant first arrived in the United States last year. In February, a study that analyzed half a million coronavirus tests and hundreds of genomes predicted that this variant could become predominant in the country in a month. At that time, the C.D.C. was struggling to sequence the new variants, which made it difficult to track them.But those efforts have substantially improved in recent weeks and will continue to grow, in large part because of $1.75 billion in funds for genomic sequencing in the stimulus package that Mr. Biden signed into law last month. By contrast, Britain, which has a more centralized health care system, began a highly promoted sequencing program last year that allowed it to track the spread of the B.1.1.7 variant.“We knew this was going to happen: This variant is a lot more transmissible, much more infectious than the parent strain, and that obviously has implications,” said Dr. Carlos del Rio, a professor of medicine and an infectious disease expert at Emory University. In addition to spreading more efficiently, he said, the B.1.1.7 strain appears to cause more severe disease, “so that gives you a double whammy.”Perhaps even more troubling is the emergence of the virulent P.1 variant in North America. First identified in Brazil, it has become the dominant variant in that country, helping to drive its hospitals to the breaking point. In Canada, the P.1 variant emerged as a cluster in Ontario, then shut down the Whistler ski resort in British Columbia. On Wednesday, the National Hockey League’s Vancouver Canucks said at least 21 players and four staff members had been infected with the coronavirus.“This is a stark reminder of how quickly the virus can spread and its serious impact, even among healthy, young athletes,” the team’s doctor, Jim Bovard, said in a statement.

Eight months after mild COVID-19, one in ten people still has at least one moderate to severe symptom that is perceived as having a negative impact on their work, social or home life. The most common long-term symptoms are a loss of smell and taste and fatigue. This is according to a study published in the journal JAMA, conducted by researchers at Danderyd Hospital and Karolinska Institutet in Sweden.
Since spring 2020, researchers at Danderyd Hospital and Karolinska Institutet have conducted the so-called COMMUNITY study, with the main purpose of examining immunity after COVID-19. In the first phase of the study in spring 2020, blood samples were collected from 2,149 employees at Danderyd Hospital, of whom about 19 percent had antibodies against SARS-CoV-2. Blood samples have since then been collected every four months, and study participants have responded to questionnaires regarding long-term symptoms and their impact on the quality of life.
In the third follow-up in January 2021, the research team examined self-reported presence of long-term symptoms and their impact on work, social and home life for participants who had had mild COVID-19 at least eight months earlier. This group consisted of 323 healthcare workers (83 percent women, median age 43 years) and was compared with 1,072 healthcare workers (86 percent women, median age 47 years) who did not have COVID-19 throughout the study period.
The results show that 26 percent of those who had COVID-19 previously, compared to 9 percent in the control group, had at least one moderate to severe symptom that lasted more than two months and that 11 percent, compared to 2 percent in the control group, had a minimum of one symptom with negative impact on work, social or home life that lasted at least eight months. The most common long-term symptoms were loss of smell and taste, fatigue, and respiratory problems.
“We investigated the presence of long-term symptoms after mild COVID-19 in a relatively young and healthy group of working individuals, and we found that the predominant long-term symptoms are loss of smell and taste. Fatigue and respiratory problems are also more common among participants who have had COVID-19 but do not occur to the same extent,” says Charlotte Thålin, specialist physician, Ph.D. and lead researcher for the COMMUNITY study at Danderyd Hospital and Karolinska Institutet. “However, we do not see an increased prevalence of cognitive symptoms such as brain fatigue, memory and concentration problems or physical disorders such as muscle and joint pain, heart palpitations or long-term fever.”
“Despite the fact that the study participants had a mild COVID-19 infection, a relatively large proportion report long-term symptoms with an impact on quality of life. In light of this, we believe that young and healthy individuals, as well as other groups in society, should have great respect for the virus that seems to be able to significantly impair quality of life, even for a long time after the infection,” says Sebastian Havervall, deputy chief physician at Danderyd Hospital and PhD student in the project at Karolinska Institutet.
The COMMUNITY study will now continue, with the next follow-up taking place in May when a large proportion of study participants are expected to be vaccinated. In addition to monitoring immunity and the occurrence of re-infection, several projects regarding post- COVID are planned.
“We will, among other things, be studying COVID-19-associated loss of smell and taste more closely, and investigate whether the immune system, including autoimmunity, plays a role in post-COVID,” says Charlotte Thålin.
Story Source:
Materials provided by Karolinska Institutet. Note: Content may be edited for style and length.

Sutures are used to close wounds and speed up the natural healing process, but they can also complicate matters by causing damage to soft tissues with their stiff fibers. To remedy the problem, researchers from Montreal have developed innovative tough gel sheathed (TGS) sutures inspired by the human tendon.
These next-generation sutures contain a slippery, yet tough gel envelop, imitating the structure of soft connective tissues. In putting the TGS sutures to the test, the researchers found that the nearly frictionless gel surface mitigated the damage typically caused by traditional sutures.
Conventional sutures have been around for centuries and are used to hold wounds together until the healing process is complete. But they are far from ideal for tissue repair. The rough fibers can slice and damage already fragile tissues, leading to discomfort and post-surgery complications.
Part of the problem lies in the mismatch between our soft tissues and the rigid sutures that rub against contacting tissue, say the researchers from McGill University and the INRS Énergie Matériaux Télécommunications Research Centre.
Inspired by the tendon
To tackle the problem, the team developed a new technology that mimics the mechanics of tendons. “Our design is inspired by the human body, the endotenon sheath, which is both tough and strong due to its double-network structure. It binds collagen fibers together while its elastin network strengthens it,” says lead author Zhenwei Ma, a PhD student under the supervision of Assistant Professor Jianyu Li at McGill University.
The endotenon sheath not only forms a slippery surface to reduce friction with surrounding tissues in joints, but it also delivers necessary materials for tissue repair in a tendon injury. In the same way, TGS sutures can be engineered to provide personalized medicine based on a patient’s needs, say the researchers.
Personalized wound treatment
“This technology provides a versatile tool for advanced wound management. We believe it could be used to deliver drugs, prevent infections, or even monitor wounds with near-infrared imaging,” says Li of the Department of Mechanical Engineering.
“The ability to monitor wounds locally and adjust the treatment strategy for better healing is an exciting direction to explore,” says Li, who is also a Canada Research Chair in Biomaterials and Musculoskeletal Health.
Story Source:
Materials provided by McGill University. Note: Content may be edited for style and length.

Social distancing and lockdowns may have reduced the spread of COVID-19, but researchers from Penn State College of Medicine also report those actions may have affected clinical researchers’ ability to finish trials. Study completion rates dropped worldwide between 13% and 23%, depending on the type of research sponsor and geographic location, between April and October 2020.
Researchers previously reported that more than 80% of clinical trials suspended between March 1 and April 26, 2020, noted the pandemic as their chief reason for halting activity. Patient enrollment in studies was lower in April 2020, compared to April 2019. Arthur Berg, associate professor of public health sciences, and Nour Hawila, a biostatistics doctoral candidate, investigated how these trends may have affected the completion of clinical trials.
The researchers examined more than 117,000 trials in the United States, Europe, Asia and other regions to study whether the pandemic affected clinical research. Their goal was to assess how the pandemic’s mitigation efforts and financial setbacks may have contributed to decreased clinical trial enrollment and completion.
“The pandemic has made it more difficult for researchers to recruit and follow up on patients in clinical trials,” said Hawila, a research assistant from the Department of Public Health Sciences. “This analysis revealed that the impact was substantial — particularly for trials funded by government, academic or medical entities.”
Hawila and Berg analyzed data from ClinicalTrials.gov, a website that contains information on the status of thousands of clinical trials in the U.S. Pre-COVID-19 enrollment and completion data was pulled from March 2017 to February 2020. The post-COVID-19 period was defined as April through October 2020.
According to researchers, the pandemic reduced the number of new interventional clinical trial submissions to ClinicalTrials.gov by about 10%. Completed trials were down 13% to 23%, depending on the sector and location of the trial source. Clinical trials sponsored by pharmaceutical, biotechnology and therapeutic companies were more likely to complete enrollment.
However, some regions fared better than others during the pandemic. Egypt experienced an increase in both submitted (69%) and completed (73%) clinical trials. Berg explained that the rise is likely in response to the country’s recent parliamentary bill governing medical research.
Berg and Hawila also noted that the pandemic caused a shift in research priorities — 472 (11%) of trials submitted during the post-COVID period were pandemic-related. The results were published in the journal Clinical and Translational Science.
“Clinical research response to the pandemic has been robust,” said Berg, a Penn State Cancer Institute researcher and biostatistics doctoral program director. “But the impact of the pandemic on other types of clinical trials will be felt for decades to come. However, as demonstrated in Egypt, timely governmental action may be able to make a difference in reversing the pandemic’s impact on research.”
Story Source:
Materials provided by Penn State. Original written by Zachary Sweger. Note: Content may be edited for style and length.

Cancer doctors may soon have a new tool for treating melanoma and other types of cancer, thanks to work being done by researchers at the University of Colorado Cancer Center.
In a paper published in the journal PNAS last month, CU Cancer Center members Mayumi Fujita, MD, PhD, Angelo D’Alessandro, PhD, Morkos Henen, PhD, MS, Beat Vogeli, PhD, Eric Pietras, PhD, James DeGregori, PhD, Carlo Marchetti, PhD, and Charles Dinarello, MD, along with Isak Tengesdal, MS, a graduate student in the Division of Infectious Diseases at the University of Colorado School of Medicine, detail their work on NLRP3, an intracellular complex that has been found to participate in melanoma-mediated inflammation, leading to tumor growth and progression. By inhibiting NLRP3, the researchers found, they can reduce inflammation and the resultant tumor expansion.
Specifically, NLRP3 promotes inflammation by inducing the maturation and release of interleukin-1-beta, a cytokine that causes inflammation as part of the normal immune response to infection. In cancer, however, inflammation can cause tumors to grow and spread.
“NLRP3 is a member of a larger family that is involved in sensing danger signals,” Marchetti says. “It is a receptor that surveils the intercellular compartment of a cell, looking for danger molecules or pathogens. When NLRP3 recognizes these signals, it leads to the activation of caspase-1, a protein involved in the processing and maturation of interleukin-1-beta into its biological active form, causing an intense inflammatory response. We found that in melanoma, this process is dysregulated, resulting in tumor growth.”
The oral NLRP3 inhibitor used in their study (Dapansutrile) has already shown to be effective in clinical trials to treat gout and heart disease, and it is currently being tested in COVID-19 as well. The CU cancer researchers are now trying to find out if this NLRP3 inhibitor can be successfully used in melanoma patients who are resistant to checkpoint inhibitors.
“Checkpoint inhibitors increase the efficacy of the immune system to kill tumors, but sometimes tumors become resistant to this treatment,” Marchetti says. “A big part of cancer research now is to find therapies that can be combined with checkpoint inhibitors to improve their efficacy.”
With the hypothesis that an NLRP3 inhibitor is one of those therapies, CU Cancer Center researchers are studying the drug’s effects on melanoma, as well as breast cancer and pancreatic cancer. In addition to improving the immune response, the NLRP3 inhibitor can also help reduce the side effects of checkpoint inhibitors. Marchetti says this research can make a big difference for melanoma patients who don’t respond to checkpoint inhibitors alone.
“This was a very collaborative project that involved a lot of members of the university, and we are very excited about it,” he says. This project is important because it further shows that NLRP3-mediated inflammation plays a critical role in the progression of melanoma, and it opens new strategies to improve patient care.”
Story Source:
Materials provided by University of Colorado Anschutz Medical Campus. Original written by Greg Glasgow. Note: Content may be edited for style and length.

Around the world, a huge amount of research and development work is currently being done on carbon-containing, or organic, molecules that emit coloured light after appropriate excitation. This research field is driven by the display industry and the development of biomedical imaging techniques. While precise colour tuning in organic fluorescent dyes has so far usually been achieved by mixing different molecules, ETH researchers have now developed an approach that can generate a broad palette of colours by way of chemical adjustments within the molecules themselves.
Yinyin Bao, a group leader in the group of ETH professor Jean-Christophe Leroux, and his team of scientists turned to fluorescent organic polymers for this work. These polymers can best be thought of as moving chains of varying lengths. “The chains have a symmetrical structure, and two components within them contribute to the fluorescence,” Bao explains. “One component, called the fluorophore, sits in the middle of the chain, while the other component occurs once at each of the chain’s two ends.” Joining the fluorophore in the middle of the chain with each end of the chain are links whose number and structure scientists can adjust. If the polymer chain is bent so that one of its ends comes to lie near the fluorophore and the chain is simultaneously irradiated with UV light, it fluoresces.
Distance affects the interaction
The scientists have now been able to show that the fluorescence colour depends not only on the structure of the chain links and ends, but also on the number of chain links. “It’s the interaction of the chain end and the fluorophore that’s responsible for the fluorescence of these polymers,” Bao says: “The distance between the two components affects how they interact and thus the colour that’s emitted.”
Using a method called living polymerisation, the researchers can regulate the number of chain links. First, they gradually grow the chain by a slow process of attaching building blocks to the fluorophore. Once the desired length is reached, the scientists can terminate the process and simultaneously generate the chain end molecule. This is how the researchers produced polymers with different colours: with fewer than 18 building blocks, the molecules fluoresce yellow; with 25 chain links, green; and with 44 or more links, blue. “What’s special about this is that these differently luminescent polymers are all composed of the exact same components. The only difference is the chain length,” Bao says.
Wide colour range OLEDs
The research team, including scientists from the group of ETH Professor Chih-Jen Shih and from the Royal Melbourne Institute of Technology in Australia, published their work in the journal Science Advances. Currently, the researchers can produce fluorescent polymers in yellow, green and blue, but they are working on extending the principle to include other colours, including red.
These new fluorescent polymers can’t be used directly as OLEDs (organic LEDs) in displays because their electrical conductivity is not sufficiently high, Bao explains. However, it ought to be possible to combine the polymers with semiconducting molecules in order to produce wide colour range OLEDs in a simple way. Used in concentrated solar power plants, they could also collect sunlight more efficiently and thus increase the plants’ efficiency. Bao sees their main areas of application in laboratory diagnostic procedures that use fluorescence, for example in PCR, as well as in microscopy and imaging procedures in cell biology and medicine. Other potential uses would be as security features on banknotes and certificates or in passports.
Story Source:
Materials provided by ETH Zurich. Original written by Fabio Bergamin. Note: Content may be edited for style and length.

Tracking carbon dioxide levels indoors is an inexpensive and powerful way to monitor the risk of people getting COVID-19, according to new research from the Cooperative Institute for Research in Environmental Sciences (CIRES) and the University of Colorado Boulder. In any given indoor environment, when excess CO2 levels double, the risk of transmission also roughly doubles, two scientists reported this week in Environmental Science & Technology Letters.
The chemists relied on a simple fact already put to use by other researchers more than a decade ago: Infectious people exhale airborne viruses at the same time as they exhale carbon dioxide. That means CO2 can serve as a “proxy” for the number of viruses in the air.
“You’re never safe indoors sharing air with others, but you can reduce the risk,” said Jose-Luis Jimenez, co-author of the new assessment, a CIRES Fellow and professor of chemistry at the University of Colorado Boulder.
“And CO2 monitoring is really the only low-cost and practical option we have for monitoring,” said Zhe Peng, a CIRES and chemistry researcher, and lead author of the new paper. “There is nothing else.”
For many months, researchers around the world have been searching for a way to continually monitor COVID-19 infection risk indoors, whether in churches or bars, buses or hospitals. Some are developing instruments that can detect viruses in the air continually, to warn of a spike or to indicate relative safety. Others tested existing laboratory-grade equipment that costs tens of thousands of dollars.
Jimenez and colleagues turned to commercially available carbon dioxide monitors, which can cost just a few hundred dollars. First, they confirmed in the laboratory that the detectors were accurate. Then, they created a mathematical “box model” of how an infected person exhales viruses and CO2, how others in the room inhaled and exhaled, and how the viruses and gas accumulate in the air of a room or are removed by ventilation. The model takes into consideration infection numbers in the local community, but it does not detail air flow through rooms — that kind of modeling requires expensive, custom analysis for each room.
It’s important to understand that there is no single CO2 level at which a person can assume a shared indoor space is “safe,” Peng emphasized. That’s partly because activity matters: Are people in the room singing and talking loudly or exercising, or are they sitting quietly and reading or resting? A CO2 level of 1,000 ppm, which is well above outside levels of about 400 ppm, could be relatively safe in a quiet library with masks but not in an active gym without masks.
But in each indoor space, the model can illuminate “relative” risk: If CO2 levels in a gym drop from 2,800 to 1,000 ppm (~2,400 above background levels to 600), the risk of COVID-19 transmission drops, too, to one-quarter of the original risk. In the library, if an influx of people makes CO2 jump from 800 to 1,600 (400 to 1,200 above background), COVID transmission risk triples.
In the new paper, Peng and Jimenez also shared a set of mathematical formulae and tools that experts in building systems and public health can use to pin down actual, not just relative, risk. But the most important conclusion is that to minimize risk, keep the CO2 levels in all the spaces where we share air as low as practically possible.
“Wherever you are sharing air, the lower the CO2, the lower risk of infection,” Jimenez said.

A recent study finds that unhealthy eating behaviors at night can make people less helpful and more withdrawn the next day at work.
“For the first time, we have shown that healthy eating immediately affects our workplace behaviors and performance,” says Seonghee “Sophia” Cho, corresponding author of the study and an assistant professor of psychology at North Carolina State University. “It is relatively well established that other health-related behaviors, such as sleep and exercise, affect our work. But nobody had looked at the short-term effects of unhealthy eating.”
Fundamentally, the researchers had two questions: Does unhealthy eating behavior affect you at work the next day? And, if so, why?
For the study, researchers had 97 full-time employees in the United States answer a series of questions three times a day for 10 consecutive workdays. Before work on each day, study participants answered questions related to their physical and emotional well-being. At the end of each workday, participants answered questions about what they did at work. In the evening, before bed, participants answered questions about their eating and drinking behaviors after work.
In the context of the study, researchers defined “unhealthy eating” as instances when study participants felt they’d eaten too much junk food; when participants felt they’d had too much to eat or drink; or when participants reporting having too many late-night snacks.
The researchers found that, when people engaged in unhealthy eating behaviors, they were more likely to report having physical problems the next morning. Problems included headaches, stomachaches and diarrhea. In addition, when people reported unhealthy eating behaviors, they were also more likely to report emotional strains the next morning — such as feeling guilty or ashamed about their diet choices. Those physical and emotional strains associated with unhealthy eating were, in turn, related to changes in how people behaved at work throughout the day.