Human hair-inspired body armour in the offing

January 18, 2017

Los Angeles, Jan 18: Scientists have found why human hair is incredibly strong and resistant to breaking, a finding that may lead to new generation of materials for body armours and even help create better hair care products.

hairHair has a strength to weight ratio comparable to steel. It can be stretched up to one and a half times its original length before breaking, researchers said.

"We wanted to understand the mechanism behind this extraordinary property," said Yang Yu, a PhD student at the University of California San Diego.

"We're interested in understanding the correlation between the structure and the properties of biological materials to develop synthetic materials and designs - based on nature - that have better performance than existing ones," said Marc Meyers, a professor at UC San Diego.

Researchers examined at the nanoscale level how a strand of human hair behaves when it is deformed, or stretched. The team found that hair behaves differently depending on how fast or slow it is stretched. The faster hair is stretched, the stronger it is.

"Think of a highly viscous substance like honey. If you deform it fast it becomes stiff, but if you deform it slowly it readily pours," said Meyers.

Hair consists of two main parts - the cortex, which is made up of parallel fibrils, and the matrix, which has an amorphous (random) structure.

The matrix is sensitive to the speed at which hair is deformed, while the cortex is not. The combination of these two components, Yu explained, is what gives hair the ability to withstand high stress and strain.

As hair is stretched, its structure changes in a particular way. At the nanoscale, the cortex fibrils in hair are each made up of thousands of coiled spiral-shaped chains of molecules called alpha helix chains.

As hair is deformed, the alpha helix chains uncoil and become pleated sheet structures known as beta sheets. This structural change allows hair to handle up a large amount deformation without breaking.

This structural transformation is partially reversible. When hair is stretched under a small amount of strain, it can recover its original shape. Stretch it further, the structural transformation becomes irreversible.

"This is the first time evidence for this transformation has been discovered," Yu said.

"Hair is such a common material with many fascinating properties," said Bin Wang, a UC San Diego PhD alumna.

The team also conducted stretching tests on hair at different humidity levels and temperatures. At higher humidity levels, hair can withstand up to 70 to 80 per cent deformation before breaking. Water essentially "softens" hair - it enters the matrix and breaks the sulphur bonds connecting the filaments inside a strand of hair.

Researchers also found that hair starts to undergo permanent damage at 60 degrees Celsius. Beyond this temperature, hair breaks faster at lower stress and strain.

Comments

Add new comment

  • Coastaldigest.com reserves the right to delete or block any comments.
  • Coastaldigset.com is not responsible for its readers’ comments.
  • Comments that are abusive, incendiary or irrelevant are strictly prohibited.
  • Please use a genuine email ID and provide your name to avoid reject.
Agencies
May 8,2020

As Europe and the US loosen their lockdowns against the coronavirus, health experts are expressing growing dread over what they say is an all-but-certain second wave of deaths and infections that could force governments to clamp back down.

"We are risking a backslide that will be intolerable," said Dr Ian Lipkin of Columbia University's Center for Infection and Immunity.

Around the world, German authorities began drawing up plans in case of a resurgence of the virus. Experts in Italy urged intensified efforts to identify new victims and trace their contacts. And France, which has not yet eased its lockdown, has already worked up a "reconfinement plan" in the event of a new wave.

"There will be a second wave, but the problem is to which extent. Is it a small wave or a big wave? It is too early to say," said Olivier Schwartz, head of the virus unit at France's Pasteur Institute.

In the US, with about half of the states easing their shutdowns to get their economies restarted and cellphone data showing that people are becoming restless and increasingly leaving home, public health authorities are worried.

Many states have not put in place the robust testing that experts believe is necessary to detect and contain new outbreaks. And many governors have pressed ahead before their states met one of the key benchmarks in the Trump administration's guidelines for reopening -- a 14-day downward trajectory in new illnesses and infections.

"If we relax these measures without having the proper public health safeguards in place, we can expect many more cases and, unfortunately, more deaths," said Josh Michaud, associate director of global health policy with the Kaiser Family Foundation in Washington.

Cases have continued to rise steadily in places such as Iowa and Missouri since the governors began reopening, while new infections have yo-yoed in Georgia, Tennessee and Texas.

Lipkin said he is most worried about two things: the reopening of bars, where people crowd together and lose their inhibitions, and large gatherings such as sporting events, concerts and plays. Preventing outbreaks will require aggressive contact tracing powered by armies of public health workers hundreds of thousands of people strong, which the US does not yet have, Lipkin said.

Worldwide the virus has infected more than 36 lakh people and killed over a quarter-million, according to a tally by Johns Hopkins University that experts agree understates the dimensions of the disaster because of limited testing, differences in counting the dead and concealment by some governments.

The US has recorded over 70,000 deaths and 12 lakh confirmed infections, while Europe has reported over 140,000 dead.

This week, the researchers behind a widely cited model from the University of Washington nearly doubled their projection of deaths in the US to around 134,000 through early August, in large part because of the easing of state stay-at-home restrictions. Newly confirmed infections per day in the US exceed 20,000 and deaths per day are running well over 1,000.

In hard-hit New York City, which has managed to bring down deaths dramatically even as confirmed infections continue to rise around the rest of the country, Mayor Bill de Blasio warned that some states may be reopening too quickly.

"My message to the rest of the country is learn from how much effort, how much discipline it took to finally bring these numbers down and follow the same path until you are sure that it is being beaten back," he said on CNN, "or else, if this thing boomerangs, you are putting off any kind of restart or recovery a hell of a lot longer."

A century ago, the Spanish flu epidemic's second wave was far deadlier than its first, in part because authorities allowed mass gatherings from Philadelphia to San Francisco.

"It is clear to me that we are in a critical moment of this fight. We risk complacency and accepting the preventable deaths of 2,000 Americans each day," epidemiologist Caitlin Rivers, a professor at Johns Hopkins, told a House subcommittee in Washington.

President Donald Trump, who has pressed hard to ease the restrictions that have throttled the economy and thrown more than three crore Americans out of work, pulled back Wednesday on White House plans revealed a day earlier to wind down the coronavirus task force.

He tweeted that the task force will continue meeting indefinitely with a "focus on SAFETY & OPENING UP OUR COUNTRY AGAIN".

Underscoring those economic concerns, the European Union predicted the worst recession in its quarter-century history. And the US unemployment rate for April, which comes out on Friday, is expected to hit a staggering 16 per cent, a level last seen during the Great Depression of the 1930s.

Governors continue to face demands, even lawsuits, to reopen. In Michigan, where armed demonstrators entered the Capitol last week, the Republican-led Legislature sued Democratic Governor Gretchen Whitmer, asking a judge to declare invalid her stay-at-home order, which runs at least through May 15.

In hard-hit Italy, which has begun easing restrictions, Dr Silvio Brusaferro, president of the Superior Institute of Health, urged "a huge investment" of resources to train medical personnel to monitor possible new cases of the virus, which has killed about 30,000 people nationwide.

He said that contact-tracing apps which are being built by dozens of countries and companies are not enough to manage future waves of infection.

German Chancellor Angela Merkel said after meeting with the country's 16 governors that restaurants and other businesses will be allowed to reopen in the coming weeks but that regional authorities will have to draw up a "restriction concept" for any county that reports 50 new cases for every 100,000 inhabitants within a week.

Lothar Wieler, head of Germany's national disease control centre, said scientists "know with great certainty that there will be a second wave" of infections.

Britain, with over 30,000 dead, the second-highest death toll in the world behind the US, plans to extend its lockdown but has begun recruiting 18,000 people to trace contacts of those infected.

In other developments, the US Centers for Disease Control and Prevention said nearly 5,000 coronavirus illnesses and at least 88 deaths have been reported among inmates in American jails and prisons. An additional 2,800 cases and 15 deaths were reported among guards and other staff members.

Comments

Add new comment

  • Coastaldigest.com reserves the right to delete or block any comments.
  • Coastaldigset.com is not responsible for its readers’ comments.
  • Comments that are abusive, incendiary or irrelevant are strictly prohibited.
  • Please use a genuine email ID and provide your name to avoid reject.
Agencies
April 17,2020

Washington DC, Apr 17: In recent research, scientists have linked the emotional, social and psychiatric problems in children and adolescents with higher levels of genetic vulnerability for adult depression. The study implies that the genetics passed from parents may be linked with psychiatric problems in children and adolescents and may also leading to depression in adults.

University of Queensland scientists made the finding while analysing the genetic data of more than 42,000 children and adolescents from seven cohorts across Finland, the Netherlands, Norway, Sweden and the UK.

Professor Christel Middeldorp said that researchers have also found a link with a higher genetic vulnerability for insomnia, neuroticism and body mass index.

"By contrast, study participants with higher genetic scores for educational attainment and emotional well-being were found to have reduced childhood problems," Professor Middeldorp said.

"We calculated a person's level of genetic vulnerability by adding up the number of risk genes they had for a specific disorder or trait and then made adjustments based on the level of importance of each gene We found the relationship was mostly similar across ages," Middeldorp added.

The results indicate there are shared genetic factors that affect a range of psychiatric and related traits across a person's lifespan.

Middeldorp said that around 50 per cent of children and adolescents with psychiatric problems, such as attention deficit hyperactivity disorder (ADHD), continue to experience mental disorders as adults, and are at risk of disengaging with their school community among other social and emotional problems.

"Our findings are important as they suggest this continuity between childhood and adult traits is partly explained by genetic risk," the Professor said.

"Individuals at risk of being affected should be the focus of attention and targeted treatment," Middeldorp continued.

"Although the genetic vulnerability is not accurate enough at this stage to make individual predictions about how a person's symptoms will develop over time, it may become so in the future, in combination with other risk factors. And, this may support precision medicine by providing targeted treatments to children at the highest risk of persistent emotional and social problems," Middeldorp added.

Comments

Add new comment

  • Coastaldigest.com reserves the right to delete or block any comments.
  • Coastaldigset.com is not responsible for its readers’ comments.
  • Comments that are abusive, incendiary or irrelevant are strictly prohibited.
  • Please use a genuine email ID and provide your name to avoid reject.
Agencies
June 30,2020

Between 30-40 per cent of deaths from studies in intensive care units from different countries are people with diabetes, said Paul Zimmet, Professor of Diabetes, Monash University, Australia.

Zimmet, who is President International Diabetes Federation, added that the actual mechanism as to why COVID-19 may cause diabetes is as yet unknown, however, several possibilities exist. "COVID-19 is a very destructive and cunning virus and causes terrible damage to tissues including the lungs and pancreas," said Zimmet. Below are excerpts from an exclusive chat with IANS.

Why do you say Diabetes is dynamite if a person has been infected with COVID-19?

There have been many deaths in many countries, e.g. Italy, China, the UK and US among people with diabetes after infection with COVID-19 (SARS-Cov-2).

The mortality tends to be mainly in older Type 2 diabetics. Between 30-40 per cent of deaths from studies in intensive care units from different countries are people with diabetes. This outcome and other complications from the virus, particularly pneumonia, are more likely in people with diabetes which is poorly controlled with high blood sugars (poor metabolic control).

Diabetes is often associated with other chronic conditions, including obesity, hypertension and heart disease compounding the risk. These latter conditions all convey higher risk to COVID-19 infections.

ACE-2, which binds to SARS-Cov-2 and allows the virus to enter human cells is also located in organs and tissues involved in glucose metabolism. Is there solid evidence that virus after entering tissues may cause multiple and complex impairment of glucose metabolism?

The actual mechanism as to why COVID-19 may cause diabetes is as yet unknown.

However, several possibilities exist. Firstly, COVID-19 is a very destructive and cunning virus and causes terrible damage to tissues, including the lungs and pancreas.

A new study just published showed that in miniature lab-grown pancreas, and other cells such as liver, made using human stem cells, COVID-19 caused destruction of the pancreas beta cells that produce insulin.

It is possible that the virus causes disruption of the cells by disrupting cellular metabolism. This is possibly the way it brings about new-onset diabetes. ACE-2 exists in high concentration in the lung as this also explains the terrible lung side effects of COVID-19 infections.

Can COVID-19 lead to a new mechanism of diabetes? Probably a new form of diabetes or a new form of disease?

The COVID-19 virus has only been with us for about 5 months and there is a huge amount that we still must learn about its cunning and devastating ways. The purpose of the Global COVIDIAB Diabetes Registry, a joint initiative of Monash University in Australia, and King’s College London is to gain a much better understanding of how common is the appearance of COVID-19 related diabetes, what form does it take be it type 1 or type 2 or a new form, and how common are the complications that we already know e.g. diabetic keto-acidosis, hyperosmolar coma and high insulin requirements are causing high rates of ill health and mortality worldwide. The knowledge gained will aid our understanding for developing strategies to prevent and treat this terrible virus that has caused destruction globally.

Diabetes is one of the most prevalent chronic diseases in India. According to a recent study, sugar levels of diabetic persons increased by 20 per cent during nationwide lockdown in India to contain COVID-19 outbreak. Even after lockdown was lifted, many people are confined within their home. Do you think lack of physical activity will create more problems for diabetics?

My own major research has been on studying populations with high rates of diabetes, including ethnic Indian communities including India, Mauritius, and Fiji so I am very well aware of this. It is now well established that along with diabetes, that associated poor metabolic control of their diabetes places these people at the highest risk for COVID infection and its devastating complications and the associated morbidity and mortality. And these communities have high prevalence of heart disease as well.

Lockdown not only has deleterious effects on metabolic control of the diabetes through reduced opportunities for exercise to be protective serious consequences of SARS-CoV-2 infection, lockdown usually results in disruption of the regular medical care and the regular monitoring of metabolic control. This may also be partly due to the stress and poor compliance, or inability to afford their medications such as insulin. It may also be compounded by inability to access the care during the pandemic. Nevertheless, we now know that poor metabolic control heightens their risk as described above.

You have said diabetes is itself a pandemic just like Covid-19, and the two pandemics could be clashing. How could governments address this problem?

These are “The Times of COVID-19”. Most nations of the world were totally unprepared for a pandemic of this magnitude. They underestimated its potential impact and the destructive nature of the viral infection. This should prompt all countries to upgrade their guidelines to take into account the lessons learnt on infection control including training of staff specialising in infectious diseases and improved public education and taking their communities into their confidence about the terrible nature of COVID-19. The risks of COVID-19 infection need a much higher priority in the general community, particularly for people with chronic conditions such as diabetes, obesity, and cardiac conditions.

Governments are faced with chronic diseases (NCDs) like diabetes and communicable diseases (CDs) like viral and enteric diseases and TB. In general WHO gives the highest priority to communicable diseases and much less attention and funding to chronic diseases like diabetes (I was an adviser to WHO for many years (about 30) on diabetes and obesity and it was very frustrating to deal with this situation).

This attitude to diabetes, for example, has a flow down effect so that diabetes funding in countries by governments, rich and poor, suffered and was insufficient.

So now we have a COVID-19 pandemic and who are those at highest risk, yes people with diabetes and other NCDs, it is very important that now the two, Diabetes and COVID-19 are clashing face-to-face. This is a major issue that WHO and national governments have to face with equal priority’

Stressed people suffering from diabetes run a greater risk of poor blood glucose levels, what do you suggest to these people?

As mentioned in the answer above, stress is an important factor in upsetting the blood sugar (metabolic) control of diabetes. Additive to this is poor compliance with medications and diet. These and potential associated comorbidities due to other chronic conditions are part of the dynamic dynamite mixture.

Comments

Add new comment

  • Coastaldigest.com reserves the right to delete or block any comments.
  • Coastaldigset.com is not responsible for its readers’ comments.
  • Comments that are abusive, incendiary or irrelevant are strictly prohibited.
  • Please use a genuine email ID and provide your name to avoid reject.