Healthy sleep habits help lower risk of heart failure

 

Adults with the healthiest sleep patterns had a 42% lower risk of heart failure regardless of other risk factors compared to adults with unhealthy sleep patterns, according to new research published today in the American Heart Association's flagship journal Circulation. Healthy sleep patterns are rising in the morning, sleeping 7-8 hours a day and having no frequent insomnia, snoring or excessive daytime sleepiness.

Heart failure affects more than 26 million people, and emerging evidence indicates sleep problems may play a role in the development of heart failure.

This observational study examined the relationship between healthy sleep patterns and heart failure and included data on 408,802 UK Biobank participants, ages 37 to 73 at the time of recruitment (2006-2010). Incidence of heart failure was collected until April 1, 2019. Researchers recorded 5,221 cases of heart failure during a median follow-up of 10 years.

Researchers analyzed sleep quality as well as overall sleep patterns. The measures of sleep quality included sleep duration, insomnia and snoring and other sleep-related features, such as whether the participant was an early bird or night owl and if they had any daytime sleepiness (likely to unintentionally doze off or fall asleep during the daytime).

"The healthy sleep score we created was based on the scoring of these five sleep behaviors," said Lu Qi, M.D., Ph.D., corresponding author and professor of epidemiology and director of the Obesity Research Center at Tulane University in New Orleans. "Our findings highlight the importance of improving overall sleep patterns to help prevent heart failure."

Sleep behaviors were collected through touchscreen questionnaires. Sleep duration was defined into three groups: short, or less than 7 hours a day; recommended, or 7 to 8 hours a day; and prolonged, or 9 hours or more a day.

After adjusting for diabetes, hypertension, medication use, genetic variations and other covariates, participants with the healthiest sleep pattern had a 42% reduction in the risk of heart failure compared to people with an unhealthy sleep pattern.

They also found the risk of heart failure was independently associated and:

• 8% lower in early risers;
• 12% lower in those who slept 7 to 8 hours daily;
• 17% lower in those who did not have frequent insomnia; and
• 34% lower in those reporting no daytime sleepiness.

Participant sleep behaviors were self-reported, and the information on changes in sleep behaviors during follow-up were not available. The researchers noted other unmeasured or unknown adjustments may have also influenced the findings.

Qi also noted that the study's strengths include its novelty, prospective study design and large sample size.

First-author is Xiang Li, Ph.D.; other co-authors are Qiaochu Xue, M.P.H.; Mengying Wang, M.P.H.; Tao Zhou, Ph.D.; Hao Ma, Ph.D.; and Yoriko Heianza, Ph.D. Author disclosures are detailed in the manuscript.

 

Journal Reference:

1. Xiang Li, Qiaochu Xue, Mengying Wang, Tao Zhou, Hao Ma, Yoriko Heianza, Lu Qi. Adherence to a Healthy Sleep Pattern and Incident Heart Failure: A Prospective Study of 408802 UK Biobank Participants. Circulation, 2020; DOI: 10.1161/CIRCULATIONAHA.120.050792

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Courtesy:

American Heart Association. "Healthy sleep habits help lower risk of heart failure." ScienceDaily. ScienceDaily, 16 November 2020. <www.sciencedaily.com/releases/2020/11/201116075728.htm>.

 

Researchers examine which approaches are most effective at reducing COVID-19 spread

 

Simon Fraser University professors Paul Tupper and Caroline Colijn have found that physical distancing is universally effective at reducing the spread of COVID-19, while social bubbles and masks are more situation-dependent.

The researchers developed a model to test the effectiveness of measures such as physical distancing, masks or social bubbles when used in various settings.

Their paper was published Nov. 19 in the journal Proceedings of the National Academy of Sciences of the United States of America (PNAS).

They introduce the concept of "event R," which is the expected number of people who become infected with COVID-19 from one individual at an event.

Tupper and Colijn look at factors such as transmission intensity, duration of exposure, the proximity of individuals and degree of mixing -- then examine what methods are most effective at preventing transmission in each circumstance.

The researchers incorporated data from reports of outbreaks at a range of events, such as parties, meals, nightclubs, public transit and restaurants. The researchers say that an individual's chances of becoming infected with COVID-19 depend heavily on the transmission rate and the duration -- the amount of time spent in a particular setting.

Events were categorized as saturating (high transmission probability) or linear (low transmission probability). Examples of high transmission settings include bars, nightclubs and overcrowded workplaces while low transmission settings include public transit with masks, distancing in restaurants and outdoor activities.

The model suggests that physical distancing was effective at reducing COVID-19 transmission in all settings but the effectiveness of social bubbles depends on whether chances of transmission are high or low.

In settings where there is mixing and the probability of transmission is high, such as crowded indoor workplaces, bars and nightclubs and high schools, having strict social bubbles can help reduce the spread of COVID-19.

The researchers found that social bubbles are less effective in low transmission settings or activities where there is mixing, such as engaging in outdoor activities, working in spaced offices or travelling on public transportation wearing masks.

They note that masks and other physical barriers may be less effective in saturating, high transmission settings (parties, choirs, restaurant kitchens, crowded offices, nightclubs and bars) because even if masks halve the transmission rates that may not have much impact on the transmission probability (and so on the number of infections).

The novel coronavirus is relatively new but the science continues to evolve and increase our knowledge of how to effectively treat and prevent this highly contagious virus. There is still much that we do not know and many areas requiring further study.

"It would be great to start collecting information from exposures and outbreaks: the number of attendees, the amount of mixing, the levels of crowding, the noise level and the duration of the event," says Colijn, who holds a Canada Research Chair in Mathematics for Evolution, Infection and Public Health.

 

Journal Reference:

1. Paul Tupper, Himani Boury, Madi Yerlanov, Caroline Colijn. Event-specific interventions to minimize COVID-19 transmission. Proceedings of the National Academy of Sciences, 2020; 202019324 DOI: 10.1073/pnas.2019324117 

Courtesy:

Simon Fraser University. "Researchers examine which approaches are most effective at reducing COVID-19 spread: Social bubbles and masks more situation-dependent in terms of effectiveness." ScienceDaily. ScienceDaily, 20 November 2020. <www.sciencedaily.com/releases/2020/11/201120150726.htm>.

 

Researchers examine the decline in average body temperature among healthy adults over the past two decades

In the nearly two centuries since German physician Carl Wunderlich established 98.6°F as the standard "normal" body temperature, it has been used by parents and doctors alike as the measure by which fevers -- and often the severity of illness -- have been assessed.

Over time, however, and in more recent years, lower body temperatures have been widely reported in healthy adults. A 2017 study among 35,000 adults in the United Kingdom found average body temperature to be lower (97.9°F), and a 2019 study showed that the normal body temperature in Americans (those in Palo Alto, California, anyway) is about 97.5°F.

A multinational team of physicians, anthropologists and local researchers led by Michael Gurven, UC Santa Barbara professor of anthropology and chair of the campus's Integrative Anthropological Sciences Unit, and Thomas Kraft, a postdoctoral researcher in the same department, have found a similar decrease among the Tsimane, an indigenous population of forager-horticulturists in the Bolivian Amazon. In the 16 years since Gurven, co-director of the Tsimane Health and Life History Project, and fellow researchers have been studying the population, they have observed a rapid decline in average body temperature -- 0.09°F per year, such that today Tsimane body temperatures are roughly 97.7°F.

"In less than two decades we're seeing about the same level of decline as that observed in the U.S. over approximately two centuries," said Gurven. Their analysis is based on a large sample of 18,000 observations of almost 5,500 adults, and adjust for multiple other factors that might affect body temperature, such as ambient temperature and body mass.

The anthropologists' research appears in the journal Sciences Advances.

"The provocative study showing declines in normal body temperature in the U.S. since the time of the Civil War was conducted in a single population and couldn't explain why the decline happened," said Gurven. "But it was clear that something about human physiology could have changed. One leading hypothesis is that we've experienced fewer infections over time due to improved hygiene, clean water, vaccinations and medical treatment. In our study, we were able to test that idea directly. We have information on clinical diagnoses and biomarkers of infection and inflammation at the time each patient was seen.

While some infections were associated with higher body temperature, adjusting for these did not account for the steep decline in body temperature over time, Gurven noted. "And we used the same type of thermometer for most of the study, so it's not due to changes in instrumentation," he said.

Added Kraft, "No matter how we did the analysis, the decline was still there. Even when we restricted analysis to the <10% of adults who were diagnosed by physicians as completely healthy, we still observed the same decline in body temperature over time."

A key question, then, is why body temperatures have declined over time both for Americans and Tsimane. Extensive data available from the team's long-term research in Bolivia addresses some possibilities. "Declines might be due to the rise of modern health care and lower rates of lingering mild infections now as compared to the past," Gurven explained. "But while health has generally improved over the past two decades, infections are still widespread in rural Bolivia. Our results suggest that reduced infection alone can't explain the observed body temperature declines."

It could be that people are in better condition, so their bodies might be working less to fight infection, he continued. Or greater access to antibiotics and other treatments means the duration of infection is shorter now than in the past. Consistent with that argument, Gurven said, "We found that having a respiratory infection in the early period of the study led to having a higher body temperature than having the same respiratory infection more recently."

It's also possible that greater use of anti-inflammatory drugs like ibuprofen may reduce inflammation, though the researchers found that the temporal decline in body temperature remained even after their analyses accounted for biomarkers of inflammation.

"Another possibility is that our bodies don't have to work as hard to regulate internal temperature because of air conditioning in the summer and heating in the winter," Kraft said. "While Tsimane body temperatures do change with time of year and weather patterns, the Tsimane still do not use any advanced technology for helping to regulate their body temperature. They do, however, have more access to clothes and blankets."

The researchers were initially surprised to find no single "magic bullet" that could explain the decline in body temperature. "It's likely a combination of factors -- all pointing to improved conditions," Gurven said.

According to Gurven, the finding of lower-than-expected body temperatures in the U.S., and the decline over time, had a lot of people scratching their heads. Was it a fluke? In this study, Gurven and his team confirm that body temperatures below 98.6°F are found in places outside the U.S. and the U.K. "The area of Bolivia where the Tsimane live is rural and tropical with minimal public health infrastructure," he noted. "Our study also gives the first indication that body temperatures have declined even in this tropical environment, where infections still account for much morbidity and mortality."

As a vital sign, temperature is an indicator of what's occurring physiologically in the body, much like a metabolic thermostat. "One thing we've known for a while is that there is no universal 'normal' body temperature for everyone at all times, so I doubt our findings will affect how clinicians use body temperature readings in practice" said Gurven. Despite the fixation on 98.6°F, most clinicians recognize that 'normal' temperatures have a range. Throughout the day, body temperature can vary by as much as 1°F, from its lowest in the early morning, to its highest in the late afternoon. It also varies across the menstrual cycle and following physical activity and tends to decrease as we age.

But by linking improvements in the broader epidemiological and socioeconomic landscape to changes in body temperature, the study suggests that information on body temperature might provide clues to a population's overall health, as do other common indicators such as life expectancy. "Body temperature is simple to measure, and so could easily be added to routine large-scale surveys that monitor population health," Gurven said.

 

Journal Reference:

1. Michael Gurven, Thomas S. Kraft, Sarah Alami, Juan Copajira Adrian, Edhitt Cortez Linares, Daniel Cummings, Daniel Eid Rodriguez, Paul L. Hooper, Adrian V. Jaeggi, Raul Quispe Gutierrez, Ivan Maldonado Suarez, Edmond Seabright, Hillard Kaplan, Jonathan Stieglitz, Benjamin Trumble. Rapidly declining body temperature in a tropical human population. Science Advances, 2020; 6 (44): eabc6599 DOI: 10.1126/sciadv.abc6599 

Courtesy: University of California - Santa Barbara. "A drop in temperature: Researchers examine the decline in average body temperature among healthy adults over the past two decades." ScienceDaily. ScienceDaily, 28 October 2020. <www.sciencedaily.com/releases/2020/10/201028171432.htm>.

 

Artificial pancreas effectively controls type 1 diabetes in children age 6 and up

 A clinical trial at four pediatric diabetes centers in the United States has found that a new artificial pancreas system -- which automatically monitors and regulates blood glucose levels -- is safe and effective at managing blood glucose levels in children as young as age six with type 1 diabetes. The trial was funded by the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), part of the National Institutes of Health. Results from the trial were published August 26 in the New England Journal of Medicine.

"Fewer than 1 in 5 children with type 1 diabetes are able to successfully keep their blood glucose in a healthy range with current treatment, which may have serious consequences on their long-term health and quality of life," said Guillermo Arreaza-Rubín, M.D., director of NIDDK's Diabetes Technology Program and project scientist for the study. "Earlier research showed that the system tested in this study was safe and effective for people ages 14 and older. This trial now shows us this system works in a real-world setting with younger children."

The artificial pancreas, also known as closed-loop control, is an "all-in-one" diabetes management system that tracks blood glucose levels using a continuous glucose monitor (CGM) and automatically delivers the insulin when needed using an insulin pump. The system replaces reliance on testing by fingerstick or CGM with delivery of insulin by multiple daily injections or a pump controlled by the patient or caregiver.

The study enrolled 101 children between ages 6 and 13 and assigned them to either the experimental group, which used the new artificial pancreas system or to the control group which used a standard CGM and separate insulin pump. Check-ins and data collection were conducted every other week for four months.

Study participants were instructed to continue about their daily lives so that the researchers could best understand how the system works in the typical routines of the children.

The study found that youth using the artificial pancreas system had 7% improvement in keeping blood glucose in range during the daytime, and a 26% improvement in nighttime control compared to the control group. Nighttime control is of particular importance for people with type 1 diabetes, as severe, unchecked hypoglycemia can lead to seizure, coma or even death. The overall time-in-range goal for the artificial pancreas reflected a nearly 11% improvement, which translated to 2.6 more hours per day in range.

"The improvement in blood glucose control in this study was impressive, especially during the overnight hours, letting parents and caregivers sleep better at night knowing their kids are safer," said protocol chair R. Paul Wadwa, M.D., professor of pediatrics at the Barbara Davis Center for Childhood Diabetes at the University of Colorado, Aurora (CU). "Artificial pancreas technology can mean fewer times children and their families have to stop everything to take care of their diabetes. Instead, kids can focus on being kids."

Sixteen adverse events, all classified as minor, occurred in the artificial pancreas group during the study, with most due to problems with the insulin pump equipment. Three events occurred in the control group. No cases of severe hypoglycemia or diabetic ketoacidosis occurred during the study.

"For decades, NIDDK has funded research and technology development to create a user-friendly automated device that could ease the constant burden of type 1 diabetes, from the finger sticks and insulin injections, to the insulin dose calculations and constant monitoring while improving diabetes control outcomes and preventing both short- and long-term complications of the disease," said Arreaza-Rubín.

"The artificial pancreas is a culmination of these years of effort, and it's exciting to see how this technology may benefit children with type 1 diabetes and their families, and hopefully benefit everyone with diabetes in the future."

The artificial pancreas technology used in this study, the Control-IQ system, has an insulin pump that is programmed with advanced control algorithms based on a mathematical model using the person's glucose monitoring information to automatically adjust the insulin dose. This technology was derived from a system originally developed at the University of Virginia (UVA), Charlottesville, with funding support from NIDDK.

This four-month study was part of a series of trials conducted in the International Diabetes Closed-Loop (iDCL) Study. In addition to CU and UVA, study sites included Stanford University School of Medicine, Palo Alto, California; and Yale University School of Medicine, New Haven, Connecticut. Jaeb Center for Health Research served as the data coordinating center.

Based on data from the iDCL trials, Tandem Diabetes Care has received clearance from the U.S. Food and Drug Administration for use of the Control-IQ system in children as young as age six years.

"As we continue to search for a cure for type 1 diabetes, making artificial pancreas technology that is safe and effective, such as the technology used in this study, available to children with type 1 diabetes is a major step in improving the quality of life and disease management in these youth," said NIDDK Director Dr. Griffin P. Rodgers.

The iDCL Study is one of four major research efforts funded by NIDDK through the Special Statutory Funding Program for Type 1 Diabetes to test and refine advanced artificial pancreas systems. The studies, with additional results forthcoming, are looking at factors including safety, efficacy, user-friendliness, physical and emotional health of participants, and cost.

This study was funded by NIDDK and Tandem Diabetes, Inc. Tandem provided the experimental closed-loop systems used in the trial, system-related supplies including the Dexcom CGM and Roche glucometer, and technical expertise.

 

Journal Reference:

1. Marc D. Breton, Lauren G. Kanapka, Roy W. Beck, Laya Ekhlaspour, Gregory P. Forlenza, Eda Cengiz, Melissa Schoelwer, Katrina J. Ruedy, Emily Jost, Lori Carria, Emma Emory, Liana J. Hsu, Mary Oliveri, Craig C. Kollman, Betsy B. Dokken, Stuart A. Weinzimer, Mark D. DeBoer, Bruce A. Buckingham, Daniel Cherñavvsky, R. Paul Wadwa. A Randomized Trial of Closed-Loop Control in Children with Type 1 Diabetes. New England Journal of Medicine, 2020; 383 (9): 836 DOI: 10.1056/NEJMoa2004736 

 

 Courtesy: ScienceDaily

NIH/National Institute of Diabetes and Digestive and Kidney Diseases. "Artificial pancreas effectively controls type 1 diabetes in children age 6 and up." ScienceDaily. ScienceDaily, 26 August 2020. <www.sciencedaily.com/releases/2020/08/200826175653.htm>.

Plastic-eating enzyme 'cocktail' heralds new hope for plastic waste

 

Plastic bottles and other waste (stock image).

Credit: © vladimirzuev / stock.adobe.com

 The scientists who re-engineered the plastic-eating enzyme PETase have now created an enzyme 'cocktail' which can digest plastic up to six times faster.

A second enzyme, found in the same rubbish dwelling bacterium that lives on a diet of plastic bottles, has been combined with PETase to speed up the breakdown of plastic.

PETase breaks down polyethylene terephthalate (PET) back into its building blocks, creating an opportunity to recycle plastic infinitely and reduce plastic pollution and the greenhouse gases driving climate change.

PET is the most common thermoplastic, used to make single-use drinks bottles, clothing and carpets and it takes hundreds of years to break down in the environment, but PETase can shorten this time to days.

 

The initial discovery set up the prospect of a revolution in plastic recycling, creating a potential low-energy solution to tackle plastic waste. The team engineered the natural PETase enzyme in the laboratory to be around 20 percent faster at breaking down PET.

Now, the same trans-Atlantic team have combined PETase and its 'partner', a second enzyme called MHETase, to generate much bigger improvements: simply mixing PETase with MHETase doubled the speed of PET breakdown, and engineering a connection between the two enzymes to create a 'super-enzyme', increased this activity by a further three times.

The study is published in the journal Proceedings of the National Academy of Sciences.

The team was co-led by the scientists who engineered PETase, Professor John McGeehan, Director of the Centre for Enzyme Innovation (CEI) at the University of Portsmouth, and Dr Gregg Beckham, Senior Research Fellow at the National Renewable Energy Laboratory (NREL) in the US.

Professor McGeehan said: "Gregg and I were chatting about how PETase attacks the surface of the plastics and MHETase chops things up further, so it seemed natural to see if we could use them together, mimicking what happens in nature.

"Our first experiments showed that they did indeed work better together, so we decided to try to physically link them, like two Pac-men joined by a piece of string.

"It took a great deal of work on both sides of the Atlantic, but it was worth the effort -- we were delighted to see that our new chimeric enzyme is up to three times faster than the naturally evolved separate enzymes, opening new avenues for further improvements."

The original PETase enzyme discovery heralded the first hope that a solution to the global plastic pollution problem might be within grasp, though PETase alone is not yet fast enough to make the process commercially viable to handle the tons of discarded PET bottles littering the planet.

Combining it with a second enzyme, and finding together they work even faster, means another leap forward has been taken towards finding a solution to plastic waste.

PETase and the new combined MHETase-PETase both work by digesting PET plastic, returning it to its original building blocks. This allows for plastics to be made and reused endlessly, reducing our reliance on fossil resources such as oil and gas.

Professor McGeehan used the Diamond Light Source, in Oxfordshire, a synchrotron that uses intense beams of X-rays 10 billion times brighter than the Sun to act as a microscope powerful enough to see individual atoms. This allowed the team to solve the 3D structure of the MHETase enzyme, giving them the molecular blueprints to begin engineering a faster enzyme system.

The new research combined structural, computational, biochemical and bioinformatics approaches to reveal molecular insights into its structure and how it functions. The study was a huge team effort involving scientists at all levels of their careers.

One of the most junior authors, Rosie Graham, a joint Portsmouth CEI-NREL PhD student said: "My favourite part of research is how the ideas start, whether it's over coffee, on a train commute or when passing in the university corridors it can really be at any moment.

"It's a really great opportunity to learn and grow as part of this UK-USA collaboration and even more so to contribute another piece of the story on using enzymes to tackle some of our most polluting plastics."

The Centre for Enzyme Innovation takes enzymes from the natural environment and, using synthetic biology, adapts them to create new enzymes for industry.

 

Journal Reference:

1. Brandon C. Knott, Erika Erickson, Mark D. Allen, Japheth E. Gado, Rosie Graham, Fiona L. Kearns, Isabel Pardo, Ece Topuzlu, Jared J. Anderson, Harry P. Austin, Graham Dominick, Christopher W. Johnson, Nicholas A. Rorrer, Caralyn J. Szostkiewicz, Valérie Copié, Christina M. Payne, H. Lee Woodcock, Bryon S. Donohoe, Gregg T. Beckham, John E. McGeehan. Characterization and engineering of a two-enzyme system for plastics depolymerization. Proceedings of the National Academy of Sciences, 2020; 202006753 DOI: 10.1073/pnas.2006753117 

 

 Courtesy: ScienceDaily

University of Portsmouth. "Plastic-eating enzyme 'cocktail' heralds new hope for plastic waste." ScienceDaily. ScienceDaily, 28 September 2020. <www.sciencedaily.com/releases/2020/09/200928152913.htm>.

New clues about the link between stress and depression

 

Researchers at Karolinska Institutet in Sweden have identified a protein in the brain that is important both for the function of the mood-regulating substance serotonin and for the release of stress hormones, at least in mice. The findings, which are published in the journal Molecular Psychiatry, may have implications for the development of new drugs for depression and anxiety.

After experiencing trauma or severe stress, some people develop an abnormal stress response or chronic stress. This increases the risk of developing other diseases such as depression and anxiety, but it remains unknown what mechanisms are behind it or how the stress response is regulated.

The research group at Karolinska Institutet has previously shown that a protein called p11 plays an important role in the function of serotonin, a neurotransmitter in the brain that regulates mood. Depressed patients and suicide victims have lower levels of the p11 protein in their brain, and laboratory mice with reduced p11 levels show depression- and anxiety-like behaviour. The p11 levels in mice can also be raised by some antidepressants.

The new study shows that p11 affects the initial release of the stress hormone cortisol in mice by modulating the activity of specific neurons in the brain area hypothalamus. Through a completely different signalling pathway originating in the brainstem, p11 also affects the release of two other stress hormones, adrenaline and noradrenaline. In addition, the tests showed that mice with p11 deficiency react more strongly to stress, with a higher heart rate and more signs of anxiety, compared to mice with normal p11 levels.

"We know that an abnormal stress response can precipitate or worsen a depression and cause anxiety disorder and cardiovascular disease," says first author Vasco Sousa, researcher at the Department of Clinical Neuroscience, Karolinska Institutet. "Therefore, it is important to find out whether the link between p11 deficiency and stress response that we see in mice can also be seen in patients."

The researchers believe that the findings may have implications for the development of new, more effective drugs. There is a great need for new treatments because current antidepressants are not effective enough in many patients.

"One promising approach involves administration of agents that enhance localised p11 expression, and several experiments are already being conducted in animal models of depression," says Per Svenningsson, professor at the Department of Clinical Neuroscience, Karolinska Institutet, who led the study. "Another interesting approach which needs further investigation involves developing drugs that block the initiation of the stress hormone response in the brain."

 

Journal Reference:

1. Vasco C. Sousa, Ioannis Mantas, Nikolas Stroth, Torben Hager, Marcela Pereira, Haitang Jiang, Sandra Jabre, Wojciech Paslawski, Oliver Stiedl, Per Svenningsson. P11 deficiency increases stress reactivity along with HPA axis and autonomic hyperresponsiveness. Molecular Psychiatry, 2020; DOI: 10.1038/s41380-020-00887-0

 

Courtesy: Science daily

Karolinska Institutet. "New clues about the link between stress and depression." ScienceDaily. ScienceDaily, 2 October 2020. <www.sciencedaily.com/releases/2020/10/201002105749.htm>.

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