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.

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Dr G K Sudhakar Reddy
August 4,2020

Being overweight or obese is now recognised as a serious cause of ill health and disability. There is a significant positive association between orthopaedic disorders and the level of obesity causing pain, deformity and difficulty in walking.

Excess body weight accumulation increases pressure on joints, particularly the hips, knees and ankles.

Here are a few type of  arthritis:

Osteoarthritis

It is a condition of damage/ wear and tear of the joint lining or cartilage. Obesity triggers this by loading excessive weight on the weight bearing joints like the knee and the hip. 

Knee Osteoarthritis

This is the most common arthritis especially in the Indian subcontinent.

While walking, an individual exerts 3 to 6 times pressure that of the body weight on the weight-bearing knee joint, which means in an obese with excess body weight, larger forces are exerted, which lead to higher risk of deterioration of cartilage.

In addition, there are excessive fat tissues that produce hormones and other factors that affect the joint cartilage metabolism and cause inflammation of the joints giving rise to joint pathology.  Leptin is one of the hormones causing knee osteoarthritis. 

Hip osteoarthritis

The force exerted across the hip is 3 times that of body weight. Hip osteoarthritis is caused by factors such as joint injury, increasing age and being overweight.    

Hand osteoarthritis

The observation that obese individual has a higher risk in having hand osteoarthritis has led to a hypothesis that the metabolic effect produced by fat tissue is the underlying factor. 

Osteoporosis

It is a progressive bone condition of decrease in bone mass and density (Bone Mineral Density or BMD) which can lead to an increased risk of fracture. Recent research suggests that obesity may accelerate bone loss. It is the amount of muscle mass which is seen in an active person, which accounts for bone strengthening effects and not due to the fat seen in a heavy person.

Low back pain

Low back pain from degenerative disc disease of the lumbar spine is one of the most disabling conditions in the community and overweight and obesity have the strongest association with seeking care for low back pain.

Managing Hip and Knee Osteoarthritis

Life style changes

If one is overweight, try to lose weight by doing more physical activity and eating a healthier diet. Regular exercise keeps you active and mobile and builds up muscle, thereby strengthening the joints and can improve symptoms. 

Pain Killers

Painkillers help with pain and stiffness for short term. They don’t affect the arthritis itself and won’t repair the damage to your joint. Creams and gels can be applied directly onto painful joints.

Nutritional Supplements

Glucosamine and chondroitin are nutritional supplements. Animal studies have found that glucosamine can both delay the breakdown of and repair damaged cartilage. However, there is insufficient evidence to support the use of glucosamine in humans and one can expect only a mild-to-moderate reduction in pain

Joint injections

If pain from osteoarthritis is severe joint steroid injections are injected into the joints that can reduces swelling and pain. The injections can start working within a day or so and may improve pain for several weeks or months. 

Hyaluronic acid injections, which help to lubricate your knee joint also give short term relief. In early stages. Stem cell treatment or cartilage regeneration procedures are being tried in young people with small defects, however it is still experimental and lacks long term evidence.

Surgery

May be recommended if you have severe pain or mobility problems.

Arthroscopy

If one has frequent painful locking/stiffening episodes especially in the knee joint, an operation to wash out loose fragments of bone and other tissue as joint can be performed by a minimally invasive key hole procedure called Arthroscopy.

Arthrodesis

If hip or knee replacement is not suitable, especially in young people who do heavy manual work, one can consider an operation known as an arthrodesis, which fuses your joint in a permanent position. This means that your joint will be stronger and much less painful, although you will no longer be able to move it.

Osteotomy

In young, active people in whom a knee joint replacement would fail due to excessive use one can consider an operation called an osteotomy. This involves adding or removing a small section of bone either above or below your knee joint.  This helps realign your knee so your weight is no longer focused on the damaged part of your knee. An osteotomy can relieve your symptoms of osteoarthritis, although you may still need knee replacement surgery eventually as you grow old

Joint replacement surgery

Joint replacement therapy is most commonly carried out to replace hip and knee joints. It involves replacing a damaged, worn or diseased joint with an artificial joint made of special plastics and metal.

For most people, a replacement hip or knee will last for at least 20 years, especially if it is cared for properly and not put under too much strain.

Dr G K Sudhakar Reddy is a Sr Consultant Orthopaedic Surgeon at Citizens Speciality Hospitals, Hyderabad

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Agencies
June 12,2020

Global poverty could rise to over one billion people due to the COVID-19 pandemic and more than half of the 395 million additional extreme poor would be located in South Asia, which would be the hardest-hit region in the world, according to a new report.

Researchers from King's College London and Australian National University published the new paper with the United Nations University World Institute for Development Economics Research (UNU-WIDER) said that poverty is likely to increase dramatically in middle-income developing countries and there could be a significant change in the distribution of global poverty.

The location of global poverty could shift back towards developing countries in South Asia and East Asia, the report said.

The paper, 'Precarity and the Pandemic: COVID-19 and Poverty Incidence, Intensity and Severity in Developing Countries,' finds that extreme poverty could rise to over one billion people globally as a result of the crisis.

The cost of the crisis in lost income could reach USD 500 million per day for the world's poorest people, and the intensity and severity of poverty are likely to be exacerbated dramatically.

The report said that based on the USD 1.90 a day poverty line and a 20 per cent contraction, more than half of the 395 million additional extreme poor would be located in South Asia, which would become the hardest hit region in the world mainly driven by the weight of populous India followed by sub-Saharan Africa which would comprise 30 per cent, or 119 million, of the additional poor.

The report added that as the value of the poverty line increases, a larger share of the additional poor will be concentrated in regions where the corresponding poverty line is more relevant given the average income level.

For instance, the regional distribution of the world's poor changes drastically when looking at the USD 5.50 a day poverty line the median poverty line among upper-middle-income countries.

At this level, almost 41 per cent of the additional half a billion poor under a 20 per cent contraction scenario would live in East Asia and the Pacific, chiefly China; a fourth would still reside in South Asia; and a combined 18 per cent would live in the Middle East and North Africa (MENA) and in Latin America and the Caribbean (LAC), whose individual shares are close to that recorded for sub-Saharan Africa.

India plays a significant role in driving the potential increases in global extreme poverty documented previously, comprising almost half the estimated additional poor regardless of the contraction scenario, the report said.

Nonetheless, there are other populous, low and lower-middle- income countries in South Asia, sub-Saharan Africa, and East Asia and the Pacific accounting for a sizeable share of the estimates: Nigeria, Ethiopia, Bangladesh, and Indonesia come next, in that order, concentrating a total of 18 19 per cent of the new poor, whereas the Democratic Republic of Congo, Tanzania, Pakistan, Kenya, Uganda, and the Philippines could jointly add 11 12 per cent.

Taken together, these figures imply that three quarters of the additional extreme poor globally could be living in just ten populous countries.

The report added that this high concentration of the additional extreme poor is staggering , although not necessarily unexpected given the size of each country's population.

On one hand, data shows that three of these ten countries (Ethiopia, India, and Nigeria) were among the top ten by number of extreme poor people in 1990 and remained within the ranks of that group until 2018.

Despite this crude fact, two of these countries have managed to achieve a sustained reduction in their incidence of poverty since the early 1990s, namely Ethiopia and India, reaching their lowest poverty headcount ratio ever recorded at about 22 and 13 per cent, respectively. Nonetheless, the potential contraction in per capita income/consumption imposed by the pandemic's economic effects could erase some of this progress.

The researchers are now calling for urgent global leadership from the G7, G20, and the multilateral system, and propose a three-point plan to address the impact of the COVID-19 on global poverty quickly.

Professor of International Development at King's College London and a Senior Non-Resident Research Fellow at UNU-WIDER Andy Sumner said the COVID-19 crisis could take extreme poverty back over one billion people because millions of people live just above poverty.

Millions of people live in a precarious position one shock away from poverty. And the current crisis could be that shock that pushes them into poverty.

Professor Kunal Sen, Director of UNU-WIDER said the new estimates about the level of poverty in the world and the cost of the COVID-19 pandemic to the world's poor are sobering.

We cannot stand by and see the hard work and effort of so many be eradicated. We will know what the real impact is in time, but the necessary action to ensure we achieve the Sustainable Development Goals by 2030 needs to be planned now, Sen said.

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Agencies
February 23,2020

Los Angeles, Feb 23: According to researchers, if administered quickly, a common medication that reduces bleeding could be a treatment for bleeding stroke.

The Spot Sign and Tranexamic Acid on Preventing ICH Growth - Australasia Trial (STOP-AUST) was a multicenter, prospective, randomized, double-blind, placebo-controlled, phase 2 clinical trial using the antifibrinolytic agent tranexamic acid in people with intracerebral hemorrhage (ICH).

ICH is a severe form of acute stroke with few treatment options.

Tranexamic acid is currently used to treat or prevent excessive blood loss from trauma, surgery, tooth removal, nosebleeds and heavy menstruation. For this study, one hundred patients with active brain bleeding were given either intravenous tranexamic acid or placebo within 4.5 hours of symptom onset.

Researchers analyzed brain CT scans taken during the 24-hour period after treatment with tranexamic acid or placebo.

Researchers found a trend towards reduced hemorrhage expansion in the group treated with tranexamic acid, especially in those treated within 3 hours of the brain bleed. However, this trend was not statistically significant. The finding was consistent with previous research using the medication.

"Further trials using tranexamic acid are ongoing and focusing on ultra-early treatment - within 2 hours. 

This is where the greatest opportunity for intervention appears to be. Tranexamic acid is inexpensive, safe and widely available. Our results and others provide great impetus for further, focused research using this treatment," Nawaf Yassi said.

Larger trials focused on patient outcomes are required for this therapy to enter routine clinical practice.

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