Shape-shifting vesicles mimic living cells .


Microscopic vesicles that swirl with oscillating surface patterns and sprout appendages like living cells have been unveiled by an international team of scientists. The researchers say that the tiny objects could be an important step in the development of shape-changing soft materials and may even shed light on some biological processes.

The vesicles were created using lipid bilayers and other components found in living cells. The work was done by scientists at Technische Universität München (TUM) in Germany, Brandeis University and Syracuse University in the US, SISSA International School for Advanced Studies in Italy, and Leiden University in the Netherlands

The shape shifting is achieved by creating an artificial cytoskeleton, which is the dynamic structure of microtubules found within living cells. “Here, we managed for the first time to reconstitute a part of the cytoskeleton inside a vesicle – in an active state, which means forces are exerted continuously inside the vesicle, leading to deformations and shape transformations of the vesicle,” Andreas Bausch, a researcher at TUM and team leader, toldphysicsworld.com.

Motors and scaffolding

The team formed lipid-bilayer vesicles tens of microns in diameter, and gave them an inner lining of microtubules. The researchers also added kinesin molecular motors, bound together in clusters, which formed cross-links among the microtubules. The resulting bundles of microtubules attached themselves to the inner surface of each vesicle as a nematic film – a single layer of parallel molecules with the fluid and self-assembly properties of a liquid crystal.

As in previous studies of nematic fluids on spherical surfaces, the flat sheets of parallel-aligning molecules had to bend to conform to the round surface. As a result, defects similar to the loops seen in fingerprints formed among the parallel lines. As the attractive forces in the film achieved equilibrium, the defects migrated apart and became stable at equal distances from one another. A typical number of singularities for a sphere was four, which stopped in positions at the points of an imaginary tetrahedron within the vesicle.

However, the kinesin motors ensured that the defects did not stay in place for long. Clusters of molecular motors latched onto adjacent microtubules and pulled them in opposite directions, forcing the long molecules to slide lengthwise past each other. This continuous action maintained a steady outward push, forcing each bundle to keep lengthening.

Migrating singularities

Pushed out of their stable tetrahedral points, the singularities migrated to new positions, passing through an orientation with all four in the same plane before settling again into a new tetrahedron. The motion continues as the singularities are forced out of those positions and begin another oscillation.

By creating an osmotic gradient between the inside and outside of the vesicles, the researchers could create arm-like protrusions that resemble the filopodia that occur in some living cells. As osmotic pressure deflated a vesicle, a surplus of membrane became available. In the defects, microtubules quickly took up this extra membrane as they aligned in parallel and extended outward as new appendages. When the osmotic pressure was reversed, the swelling vesicle reclaimed the surplus membrane, retracting the appendages.

“To me, it’s very cool; it’s dynamism,” says David Nelson of Harvard University. Nelson explains that all previous studies of nematic films on round surfaces focused on films in equilibrium. Defects had formed but had not moved, and no one had engineered a vesicle that grew filopodia-like appendages. “They made these defects come alive,” he says.

Hand-drawn noodles

Randall Kamien of the University of Pennsylvania points out three areas of significance. “First of all, this demonstrates that topological constraints that control equilibrium behaviour react much, much differently out of equilibrium,” he says. “Secondly [citing a figure in the paper describing the work], the beautiful mode that looks like how hand-drawn noodles are made suggests that this mechanism could be used for mixing on the few-micron level. Finally, the oscillation frequency of these states is about once per hundred seconds. Cell cycles are typically much longer. What role could oscillators at this time scale do in vivo? Are they present in cells?”

Bausch and his colleagues are focusing on future insights into basic biology. “[We want to] rebuild biological complexity by a bottom-up approach,” he says. “The big goal – very, very long term – is to rebuild cellular functions like cell migration or cell division. This is only a first step.”

Vincenzo Vitelli of Leiden University also believes that the research could improve our understanding of biology. “These synthetic structures are close enough to living organisms to provide insights into the behaviour of early life forms that marked the cross-over from inanimate to living matter,” says Vitelli, who was not involved with the research.

Wearable clip tells parents, coach about head impact


According to the U.S. Centers for Disease Control and Prevention, a concussion is a type of injury caused by a bump, blow, or jolt to the head that can change the way your brain normally works. Concussions may occur from a blow that causes the head and brain to move quickly back and forth. Sport-related concussion has been a frequent topic in the media as professionals have expressed concern over incidents that may go underreported. While football has a high incidence, girls have higher concussion rates than boys do in similar sports. Concussions happen in collision sports, such as football, rugby, or ice hockey but also in contact sports such as soccer, basketball, wrestling, and lacrosse. On Friday, for example, in just one U.S. state, the Star Tribune reported that Minnesota’s high school athletes suffered about 3,000 sports-related concussions in the past school year, with nearly half of them involving football players and one in 20 resulting in severe symptoms that lingered for more than two weeks, based on a tally by the state Department of Health. Doctors in general would agree to never ignore a head injury, no matter how minor.

What if parents and coaches could track and evaluate their children’s head impact realtime? What started out as an engineering lab project at MIT has developed into a proposed solution seeking crowdfunding, called Jolt Sensor. This is a clip that can attach to head-worn athletic equipment. When an athlete’s head accelerates in a potentially dangerous way, the sensor vibrates to alert the athlete. It also connects wirelessly to parents’ and coaches’ smartphones, using Bluetooth Low Energy, to alert them on the sidelines. The range is over 100 yards. Next step: the athlete can be evaluated on the sideline with the app’s cognitive test and concussion symptom checklist. Results along with impact data are contextualized and presented in simple terms for parents and coaches. The sensor enclosure has a rounded silicone rubber exterior and is waterproofed with a multi-week battery life. It can be recharged via micro USB port.

The creators have turned to Kickstarter to help them move the Jolt Sensor forward. “Due to the small size of our final design, we can no longer manufacture our prototypes by hand,” said the team. With funding, they said they can use third-party manufacturers to produce production-quality boards for final testing and certification. Also, the alpha version of the iOS mobile app is built and has been used to test the current prototypes. With a successful campaign, they hope to create the Android version of the app.

They said they decided to work with domestic supplier and manufacturers, and to source local options wherever possible. In addition to supporting local businesses, this offers practical benefits, they said, “and will prove crucial as we solve problems that will no doubt arise and help us to meet our anticipated shipping dates for all . We put a lot of work into trying to account for everything and set a realistic timeline that we are confident we can meet.”

The founders also note that Jolt Sensor is not a diagnostic tool but it does provide a measure of the magnitude of head impact forces. They said Jolt Sensor is intended to direct athletes toward timely medical assessments. “Concussions can only be diagnosed by a trained medical professional,” they stated. For a $100 pledge, the supporter gets a Jolt Sensor with estimated delivery of May next year.

Wearing a bra ‘does not cause cancer’, study finds


  • Researchers wanted to test claims about an association between breast cancer and bra wearing patterns  
  • No aspect of wearing a bra was associated with an increased risk of breast cancer, study concluded

Wearing a bra does not increase the risk of breast cancer, according to new research.

A study of around 1,500 post-menopausal women found those who used the garment were no more likely to develop the disease than their braless counterparts.

For more than 20 years the debate has raged, after scientists pointed out breast cancer was unknown for thousands of years until women began wearing bras.

The theory suggests a constricting bra, especially one with underwire, can block the drainage of waste products through the lymphatic glands inhibit the disposal of toxins, leading to more exposure to carcinogenic chemicals.

Lead researcher Lu Chen, from the Public Health Sciences Division at Fred Hutchinson Cancer Research Centre in Seattle wanted to test claims around an association between bra wearing and breast cancer 

Lead researcher Lu Chen, from the Public Health Sciences Division at Fred Hutchinson Cancer Research Centre in Seattle wanted to test claims around an association between bra wearing and breast cancer

A previous study of 3,000 women found among bra users, larger cup size was associated with an increased risk of  breast cancer among post-menopausal women, but was partly accounted for by obesity.

A 2005 book entitled ‘Dressed To Kill: The Link Between Breast Cancer And Bras’ also struck fear into the hearts of bra wearers and lingerie manufacturers.

It supported the idea they cause poisons to accumulate in breast tissue.

 That prompted a team from the University of Washington to study 1,513 women in the area, aged between 55 to 74.

More than 1,000 had been diagnosed with either invasive ductal carcinoma (IDC) or invasive lobular carcinoma (ICL), while the rest were healthy and acted as a control.

A face-to-face interview gathered answers to questions addressing bra cup and band sizes, the age at which participants started regularly wearing a bra, whether they wore underwire bras and the number of hours per day, and the days per week they wore a bra at different times of their lives.

No evidence of a link between breast cancer risk and bra size, type, or frequency of wearing, was found, researchers said.

Doctoral student Lu Chen, who led the research, said: ‘There have been some concerns one of the reasons why breast cancer may be more common in developed countries compared with developing countries is differences in bra wearing patterns.

How to recognize and check for breast cancer symptoms

The study found no aspect of wearing a bra was associated with an increased risk of breast cancer

The study found no aspect of wearing a bra was associated with an increased risk of breast cancer

‘Given how common bra wearing is, we thought this was an important question to address.

‘Our study found no evidence wearing a bra increases a woman’s risk for breast cancer.

‘The risk was similar no matter how many hours per day women wore a bra, whether they wore a bra with an underwire, or at what age they first began wearing a bra.’

‘There has been some suggestion in the lay media bra wearing may be a risk factor for breast cancer.

‘Some have hypothesized drainage of waste products in and around the breast may be hampered by bra wearing.

‘Given very limited biological evidence supporting such a link between bra wearing and breast cancer risk, our results were not surprising.’

The researchers wrote: ‘The findings provide reassurance to women that wearing a bra does not appear to increase the risk for the most common histological types of post-menopausal breast cancer.’

The research was published in the journal of Cancer, Epidemiology, Biomarkers and Prevention.

Introducing the new Triumph Magic Wire bra

WHO calls for action to reduce global suicide rate of 800,000 a year


  • Poor and middle-income countries rank the worst in the study
  • But some developed nations are worse than others–rates in Britain and Germany worse than much of Europe, US and Australia
  • Guyana has the highest rate of suicide, at 44.2 out of every 100,000, with North and South Korea the second and third worst

More than 800,000 people each year worldwide commit suicide – around one person every 40 seconds – with many using poisoning, hanging or shooting to end their own lives, says the study released Thursday.

In its first global report on suicide prevention, the United Nations health agency said some 75 percent of suicides are among people from poor or middle-income countries and called for more to be done to reduce access to common means of suicide.

Global suicide rate: The report found that suicides take place all over the worldand at almost any age. Globally, suicide rates are highest inpeople aged 70 and over, but in some countries, the highest rates are found among the young.

Global suicide rate: The report found that suicides take place all over the worldand at almost any age. Globally, suicide rates are highest inpeople aged 70 and over, but in some countries, the highest rates are found among the young.

High suicide rates also persist in more developed nations. South Korea, for example, has the world’s third highest rate — 28.9 out of every 100,000 people.

The United States is grouped along with countries such as Australia, Spain and much of Europe whose rates are between 10 and 14.9 per 100,000.

The report found that suicides take place all over the world and at almost any age. Globally, suicide rates are highest in people aged 70 and over, but in some countries, the highest rates are found among the young.

In the 15 to 29-year age group, suicide is the second leading cause of death globally.

The WHO’s director general Margaret Chan said the report was a ‘call for action to address a large public health problem which has been shrouded in taboo for far too long.’

Pesticide poisoning, hanging and firearms are among the most common methods of suicide globally, the report said, and evidence from Australia, Canada, Japan, New Zealand, the United States and Europe shows that restricting access to these means can help to stop people from committing suicide.

In the 15 to 29-year age group, suicide is the secondleading cause of death globally. Suicide rates as a whole go up as the country's income rate goes down

In the 15 to 29-year age group, suicide is the secondleading cause of death globally. Suicide rates as a whole go up as the country’s income rate goes down

Governments should also set up national prevention plans, the report said, noting that currently only 28 countries are known to have such strategies.

The report found that in general, more men die by suicide than women. In richer countries, three times as many men kill themselves as women, and men aged 50 and over are particularly vulnerable.

In poor and middle-income countries, young people and elderly women have higher rates of suicide than their counterparts in wealthy nations, the report found. And women over 70 are more than twice as likely to commit suicide than women aged between 15 and 29.

‘No matter where a country currently stands in suicide prevention, effective measures can be taken, even just starting at local level and on a small scale,’ said Alexandra Fleischmann, a scientist at the WHO’s department of mental health and substance abuse.

Other preventative measures include encouraging responsible reporting of suicide in the media, such as avoiding language that sensationalizes suicide.

Early identification and management of people with mental illness and drug and other substance abusers is also important.

‘Follow-up care by health workers through regular contact, including by phone or home visits, for people who have attempted suicide, together with provision of community support, are essential, because people who have already attempted suicide are at the greatest risk of trying again,’ the report said.

The WHO report was published ahead of world suicide prevention day on September 10.

 

Use Ebola survivors’ blood .


 

Bag of blood
Blood from people who had Ebola could be used as a treatment

The blood of patients who recover from Ebola should be used to treat others, the World Health Organization has announced.

West Africa is facing the largest Ebola outbreak in history and more than 2,000 people have died.

A global group of experts have been meeting to assess the experimental therapies that could contain Ebola.

The WHO also announced that Ebola vaccines could be used on the frontline by November.

Blood medicine

People produce antibodies in the blood in an attempt to fight off an Ebola infection.

In theory, those antibodies can be transferred from a survivor into a sick patient to give their immune system a boost.

However, large scale data on the effectiveness of the therapy is lacking.

Studies on the 1995 outbreak of Ebola in Democratic Republic of Congo showed seven out of eight people survived after being given the therapy.

 

Ebola casualties

Up to 5 September

2,105

Ebola deaths – probable, confirmed and suspected

  • 1,089 Liberia
  • 517 Guinea
  • 491 Sierra Leone
  • 8 Nigeria
Getty

Dr Marie Paule Kieny, an assistant director general at WHO said: “We agreed that whole blood therapies may be used to treat Ebola virus and all efforts must be invested to help infected countries to use them.

“There is a real opportunity that a blood-derived product can be used now and this can be very effective in terms of treating patients.”

She said that it was the one positive aspect of so many people being infected.

“There are also many people now who have survived and are doing well. They can provide blood to treat the other people who are sick.”

Vaccines

There is no clinically proven drug or vaccine to treat Ebola, but many are in the experimental stage.

Around 150 experts have spent the last two days investigating how to fast-track promising experimental drugs to make them available in West Africa as soon as possible.

Ebola vaccine trials started in the US this week and will be extended to centres in the UK, Mali and Gambia in the coming weeks.

First patient
The first person to take part in a vaccine trial was a 39-year-old in the US

The WHO said safety data would be ready by November 2014 and, if it proved safe, would be used in West Africa immediately.

Healthcare workers and other frontline staff would be prioritised for vaccination, the WHO said.

Experimental drugs – such as ZMapp, which has been used in seven patients including a British volunteer nurse – were also assessed.

However, the supplies of all the experimental drugs are very limited, if not exhausted.

The WHO said efforts were underway to increase production, but it would take several months.

Dr Jesse Goodman, from Georgetown University Medical Center in the US, took part in the meeting.

He said: “This is a unique opportunity to identify what new treatments and vaccines can really help people and then potentially accelerate their use.

“We don’t want to end up after this outbreak not knowing how best to prevent or treat the next one.”

Yet the WHO warned that all the talk of experimental therapies must not detract from the proven methods of infection control which have defeated all previous outbreaks.

Meanwhile, officials in Nigeria have decided to reopen schools in the country from 22 September.

They were closed as a precaution to prevent the spread of the virus.

line

Ebola virus disease (EVD)

Ebola virus
  • Symptoms include high fever, bleeding and central nervous system damage
  • Spread by body fluids, such as blood and saliva
  • Fatality rate can reach 90% – but current outbreak has mortality rate of about 55%
  • Incubation period is two to 21 days
  • There is no proven vaccine or cure
  • Supportive care such as rehydrating patients who have diarrhoea and vomiting can help recovery
  • Fruit bats, a delicacy for some West Africans, are considered to be virus’s natural host

Limiting access to pesticides can prevent suicides.


Limiting access to pesticides and firearms, among the most common methods of suicide globally, can help reduce the number of people taking their own lives, according to a latest WHO report.

Farmers spray pesticides to their farm. Limiting access to pesticides and firearms, among the most common methods of suicide globally, can help reduce the number of people taking their own lives, according to a latest WHO report. File photo

More than 800,000 people die by suicide every year, according to WHO’s first global report on suicide prevention, which found that pesticide poisoning, hanging and firearms are among the most common methods of suicide globally.

Evidence from Australia, Canada, Japan, New Zealand, the U.S. and a number of European countries shows that limiting access to these means can help prevent people dying by suicide.

“There is no single explanation of why people die by suicide. However, many suicides happen impulsively and, in such circumstances, easy access to a means of suicide — such as pesticides or firearms — can make the difference as to whether a person lives or dies,” the report said.

Another key to reducing deaths by suicide, WHO said, is a commitment by national governments to the establishment and implementation of a coordinated plan of action.

Currently, only 28 countries are known to have national suicide prevention strategies.

Suicide occurs all over the world and can take place at almost any age. Globally, suicide rates are highest in people aged 70 years and over.

In some countries, however, the highest rates are found among the young. Notably, suicide is the second leading cause of death in 15-29 year-olds globally.

Some 75 per cent of suicides occur in low- and middle-income countries (LMICs).

“One of the key methods of suicide in LMICs, particularly in countries with a high proportion of rural residents engaged in small-scale agriculture, is pesticide self-poisoning. A systematic review of world data for 1990-2007 estimated that around 30 per cent (plausible range 27-37 per cent) of global suicides are due to pesticide self-poisoning, most of which occur in LMICs,” said WHO.

Other effective measures include responsible reporting of suicide in the media, such as avoiding language that sensationalises suicide and avoiding explicit description of methods used, and early identification and management of mental and substance use disorders in communities and by health workers in particular, the report said.

Follow-up care by health workers through regular contact, including by phone or home visits, for people who have attempted suicide, together with provision of community support, are essential, because people who have already attempted suicide are at the greatest risk of trying again.

 

 

%d bloggers like this: