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Traditional model for disease spread may not work in COVID19 - مدل های مرسوم انتشار بیماریها درباره کرونا صادق نیست

A mathematical model that can help project the contagiousness and spread of infectious diseases like the seasonal flu may not be the best way to predict the continuing spread of the novel coronavirus, especially during lockdowns that alter the normal mix of the population, researchers report.

Called the R-naught, or basic reproductive number, the model predicts the average number of susceptible people who will be infected by one infectious person. It’s calculated using three main factors — the infectious period of the disease, how the disease spreads and how many people an infected individual will likely come into contact with.

Historically, if the R-naught is larger than one, infections can become rampant and an epidemic or more widespread pandemic is likely. The COVID-19 pandemic had an early R-naught between two and three.

In a letter published in Infection Control & Hospital Epidemiology.

Release date: 21 December 2020
Source: Medical College of Georgia at Augusta University

Sustained cellular immune dysregulation in individuals recovering from COVID 19 - بی نظمی ایمنی سلولی در بهبودیافتگان کرونا تا مدت ها باقی می ماند

COVID-19, which has killed 1.7 million people worldwide, does not follow a uniform path.

Many infected patients remain asymptomatic or have mild symptoms. Others, especially those with comorbidities, can develop severe clinical disease with atypical pneumonia and multiple system organ failure.

Since the first cases were reported in December 2019, the SARS-CoV-2 virus that causes COVID-19 has surged into a pandemic, with cases and deaths still mounting. Ongoing observational clinical research has become a priority to better understand how this previously unknown virus acts, and findings from this research can better inform treatment and vaccine design.

From the blood samples, researchers were able to separate specific immune cell subsets and analyze cell surface markers. From this complex information, immunologists can analyze how each individual’s immune system is responding during infection and during convalescence. Some of these results can reveal whether immune cells have become activated and exhausted by the infection. Exhausted immune cells may increase susceptibility to a secondary infection or hamper development of protective immunity to COVID-19.

In addition, the researchers were able to analyze changes over time, in two ways. The first was observing changes in surface markers over time, defined as days since the onset of symptoms for non-hospitalized samples. The second was directly comparing the frequencies of these markers between the first and second clinic visits for non-hospitalized patients who had blood samples collected at two sequential timepoints.

“Sustained cellular immune dysregulation in individuals recovering from COVID-19 infection,” published in the Journal of Clinical Investigation.

Release date: 29 December 2020
Source: University of Alabama at Birmingham

Disposable surgical masks best for being heard clearly when speaking - با ماسک های معمولی جراحی بهتر شنیده خواهید شد

The study found that disposable surgical masks offer the best acoustic performance among all tested, Corey said. Loosely woven 100% cotton masks also perform well but, as shown in a study by other Illinois researchers, they may not be as effective as surgical masks at blocking respiratory droplets. That study showed that tightly woven cotton and blended fabrics may block more droplets, but Corey’s team found that they also block more sound. Based on the droplet study, Corey suggested that multilayer masks made of loosely woven cotton may offer a reasonable compromise between droplet-blocking efficiency and acoustic performance.

The good news is that most masks do not completely block sound, they simply deflect it away from the mouth. This detail means that simple amplification devices can make masked speech more accessible to everyone. In particular, the lapel microphones that are already used in many classrooms and lecture halls are only mildly affected by face masks. Many hearing aids support remote microphone accessories that are also worn near the lapel.

The results of the team’s new study evaluating the acoustic effects of face masks on speech are published in The Journal of the Acoustical Society of America.

Release date: 23 December 2020
Source: University of Illinois

Concern about loved ones might motivate people to mask up, get vaccine - نگرانی نسبت به عزیزان باعث ایجاد انگیزه در زدن ماسک و انجام واکسیناسیون می شود

While many people have listened to messaging about wearing a mask and following social distancing guidelines to limit the spread of COVID-19, resistance remains.

A new study finds that appealing to people’s concerns for their loved ones could overcome this resistance. And it may have implications for encouraging people to mask up and get the new vaccine.

In a recent survey, people who said social distancing and COVID-safety guidelines violated their personal freedoms responded more positively to these ideas when they felt a loved one might be at risk of severe illness for COVID-19.

An and colleagues surveyed 1,074 people across the United States about their attitudes toward the coronavirus. They discovered two distinct sets of attitudes toward social distancing:

  • Positive beliefs that largely mirror public health messaging
  • Negative beliefs, including the idea that social distancing violates individual rights and freedoms

Concern about a loved one’s risk of severe COVID-19 infection was tied to both higher positive attitudes and lower negative attitudes toward social distancing. When people considered their own personal risk, they had higher positive attitudes but it did not impact their negative attitudes.

Release date: 18 December 2020
Source: Michigan Medicine – University of Michigan

Covering faces around kids wont mask emotions - کودکان از پشت ماسک هم می توانند احساسات دیگران را تشخیص دهند

The researchers showed more than 80 children, ages 7 to 13, photos of faces displaying sadness, anger or fear that were unobstructed, covered by a surgical mask, or wearing sunglasses. The kids were asked to assign an emotion to each face from a list of six labels. The faces were revealed slowly, with scrambled pixels of the original image falling into their proper place over 14 stages to better simulate the way real-world interactions may require piecing things together from odd angles or fleeting glimpses.

The kids were correct about the uncovered faces as often as 66 percent of the time, well above the odds (about 17 percent) of guessing one correct emotion from the six options. With a mask in the way, they correctly identified sadness about 28 percent of the time, anger 27 percent of the time, and fear 18 percent of the time.

Published results in the journal PLOS ONE.

Release date: 23 December 2020
Source: University of Wisconsin-Madison

Masks Not Enough to Stop COVID19 Spread Without Distancing - استفاده از ماسک بدون فاصله گذاری برای کنترل کرونا کافی نیست

Simply wearing a mask may not be enough to prevent the spread of COVID-19 without social distancing.

In Physics of Fluids, by AIP Publishing, researchers tested how five different types of mask materials impacted the spread of droplets that carry the coronavirus when we cough or sneeze.

Each of the masks captured the vast majority of droplets, ranging from the regular cloth mask, which allowed about 3.6% of the droplets to go through, to the N-95 mask, which statistically stopped 100% of the droplets. But at distances of less than 6 feet, even those small percentages of droplets can be enough to get someone sick, especially if a person with COVID-19 sneezes or coughs multiple times.

Release date: 22 December 2020
Source: American Institute of Physics

Community Spread of COVID-19 Survival Rates at Hospitals - مرگ و میر بیماران بیمارستان میزان شیوع ویروس کرونا در جامعه

Discovering wide variation in hospitals’ COVID-19 survival rates, researchers found that the levels of COVID-19 in the surrounding community was likely the driving factor.

High rates of COVID-19 in the county where a hospital is located appears to reduce survival rates among hospitalized patients with the virus, according to a new study from researchers in the Perelman School of Medicine at the University of Pennsylvania and at UnitedHealth Group. These findings were published in JAMA Internal Medicine.

The team analyzed nearly 40,000 patients with COVID-19 admitted to 955 hospitals across the nation between January 1 and June 30, 2020. They examined what proportion of those patients either died in the hospital within 30 days of being admitted or were discharged to hospice, which could also signal a likely death from the virus. They found that, on average, almost 12 percent of patients admitted with COVID-19 to hospitals nationwide died, but the mortality rates in the hospitals with the best outcomes was 9 percent compared to nearly 16 percent for the group of hospitals with the worst outcomes.

Release date: 22 December 2020
Source: University of Pennsylvania School of Medicine

COVID-19 spread increases when UV levels decrease - کاهش اشعه ماوراء بنفش در محیط باعث افزایش انتشار کرونا می گردد

Seasonal changes in UV may alter the spread of COVID-19 but not as much as social distancing.

Natural variations in ultraviolet radiation influence the spread of COVID-19, but the influence is modest compared to preventive measures such as physical distancing, mask wearing, and quarantine, according to new research from Harvard University.

Analyzing daily COVID-19 and weather data from over 3,000 administrative regions in more than 170 countries, Proctor, together with co-authors Peter Huybers, also at Harvard University, Tamma Carleton and Kyle Meng from the University of California Santa Barbara and Jules Cornetet at France’s École Normale Supérieure Paris-Saclay, found that the spread of COVID-19 through a population tended to be lower in the weeks following higher UV exposure. Findings were published in the Proceedings of the National Academy of Sciences.

Release date: 15 December 2020
Source: Harvard John A. Paulson School of Engineering and Applied Sciences

Genes could be key to new Covid-19 treatments - ژن ها میتوانند کلید درمان های جدید کرونا باشند

Genetic evidence is second only to clinical trials as a way to tell which treatments will be effective in a disease. Existing drugs that target the actions of the genes reveal which drugs should be repurposed to treat Covid-19 in clinical trials, experts say.

Genes involved in two molecular processes – antiviral immunity and lung inflammation – were pinpointed. The breakthrough will help doctors understand how Covid-19 damages lungs at a molecular level.

Researchers from the University of Edinburgh made the discovery by studying the DNA of 2,700 patients in 208 intensive care units (ICUs) in the UK.

Nature

Release date: 15 December 2020
Source: University of Edinburgh

Research strongly suggests COVID-19 virus enters the brain - شواهد قوی وجود دارد که نشان می دهد ویروس کرونا وارد مغز می شود

More and more evidence is coming out that people with COVID-19 are suffering from cognitive effects, such as brain fog and fatigue.

And researchers are discovering why. The SARS-CoV-2 virus, like many viruses before it, is bad news for the brain. In a study published Dec.16 in Nature Neuroscience, researchers found that the spike protein, often depicted as the red arms of the virus, can cross the blood-brain barrier in mice.

This strongly suggests that SARS-CoV-2, the cause of COVID-19, can enter the brain.

The spike protein, often called the S1 protein, dictates which cells the virus can enter. Usually, the virus does the same thing as its binding protein, said lead author William A. Banks, a professor of medicine at the University of Washington School of Medicine and a Puget Sound Veterans Affairs Healthcare System physician and researcher. Banks said binding proteins like S1 usually by themselves cause damage as they detach from the virus and cause inflammation.

Release date: 16 December 2020
Source: University of Washington Health Sciences/UW Medicine