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London, June 24 (IANS) Scientists from University of Bristol have found a new bio-ink for 3D printing with stem cells that allows printing of living tissue known as bio-printing.
The new bio-ink contains two different polymer components: a natural polymer extracted from seaweed and a sacrificial synthetic polymer used in the medical industry.
"Designing the new bio-ink was extremely challenging. You need a material that is printable, strong enough to maintain its shape when immersed in nutrients and that is not harmful to the cells. We managed to do this," said lead researcher Adam Perriman from school of cellular and molecular medicine.
The synthetic polymer causes the bio-ink to change from liquid to solid when the temperature is raised and the seaweed polymer provides structural support when the cell nutrients are introduced.
"The special bio-ink formulation was extruded from a retrofitted benchtop 3D printer, as a liquid that transformed to a gel at 37 degrees Celsius, which allowed construction of complex living 3D architectures," Perriman added.
The findings, published in the journal Advanced Healthcare Materials, could help printing complex tissues using the patient's own stem cells for surgical bone or cartilage implants, which could be used in knee and hip surgeries.
The team was able to differentiate the stem cells into osteoblasts -- a cell that secretes the substance of bone cells that have secreted the matrix of cartilage and become embedded in it -- to engineer 3D printed tissue structures over five weeks, including a full-size tracheal cartilage ring.
"What was really astonishing for us was when the cell nutrients were introduced, the synthetic polymer was completely expelled from the 3D structure, leaving only the stem cells and the natural seaweed polymer," Perriman noted.
This created microscopic pores in the structure which provided more effective nutrient access for the stem cells.
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New York, June 24 (IANS) A team of researchers has created a "virtual heart" that could help medical researchers study new drug therapies.
Researchers from the University of California - San Diego have created a detailed computer model of the electrophysiology of congestive heart failure -- a leading cause of death -- that can simulate subtle changes from the cellular and tissue levels of the heart then show the results of the associated electrocardiogram (ECG).
According to the results, published in the journal PLOS Computational Biology, the model can show what happens to the heart when the levels and flow of calcium, potassium and sodium ions are changed.
At the organ level, the researchers created an anatomically detailed model of the heart which shows the big picture of what happens when various critical chemicals and electrophysiologic components of a healthy working heart are tweaked.
The team also found that ventricular fibrillation, where the waves of excitation that pump blood out of the heart become fragmented and discoordinated, can be caused by a heart failure-related slowdown in cellular processes at the top (basal) region of heart.
The researchers also used their model to plan a new drug strategy against this heart failure form of fibrillation.
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London, June 22 (IANS) Children who focus more on physical activities, especially outdoor games, will have improved academic successes and reduced obesity level in an early age, new research says.
The findings showed that the physical activity levels of children are continuing to fall well short of recommended levels, which can harm their health as well as academic attainment.
They are spending far more time in front of the screens than the maximum recommendation of only two hours a day, which needs to be reduced, the study said.
"The amount of time children spend in front of screens has had an impact on their wellbeing for many years. The popularity of computer games and the emergence of the internet, smartphones and social media have contributed further to this problem,” said lead author John Reilly, Professor at University Of Strathclyde in Scotland.
Strategies to promote physical activity and reduce screen time should place a higher emphasis on playing actively outdoors, something children could potentially do 365 days a year, the researchers suggested.
"Playing benefits children in helping them to develop socially and emotionally, so promoting active outdoor play would have many benefits in addition to improving physical activity, improving academic attainment and reducing obesity," Reilly noted.
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Stockholm, June 23 (IANS) Sweden on Wednesday inaugurated a test stretch of an electric road, making it one of the first countries in the world to conduct tests with electric power for heavy transports on public roads.
The test will be conducted on parts of road E16, and involves a current collector on the roof of the truck cab feeding the current down to a hybrid electric motor in the truck, according to a press release from the country's transport administration Trafikverket, Xinhua reported.
"Electric roads will bring us one step closer to fossil fuel-free transports, and has the potential to achieve zero carbon dioxide emissions. This is one way of developing environmentally smart transports in the existing road network. It could be a good supplement to todays road and rail network," said Lena Erixon, director general of Trafikverket.
"Electric roads are one more piece of the puzzle in the transport system of the future, especially for making the heavy transport section fossil fuel-free over the long term. This project also shows the importance of all the actors in the field cooperating," said Erik Brandsma, director general of the Swedish Energy Agency.
The tests will continue up through 2018. They will provide knowledge of how electric roads work in practice, and whether the technology can be used in the future. The experiment is based on the governments goal of energy efficiency and a fossil fuel-free vehicle fleet by 2030, and will contribute to strengthening Swedens competitiveness.
Three government agencies, Swedish Transport Administration, Swedish Energy Agency, and the country's innovation agency Vinnova, are partially funding the project, while the participants are paying for the rest.
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Washington, June 22 (IANS) In a first, astronomers have discovered a vast cloud of high-energy particles called a wind nebula around a rare ultra-magnetic neutron star, or magnetar.
The find offers a unique window into the properties, environment and outburst history of magnetars, which are the strongest magnets in the universe.
A neutron star is the crushed core of a massive star that ran out of fuel, collapsed under its own weight, and exploded as a supernova.
Neutron stars are most commonly found as pulsars, which produce radio, visible light, X-rays and gamma rays at various locations in their surrounding magnetic fields.
Typical pulsar magnetic fields can be 100 billion to 10 trillion times stronger than Earth's. Magnetar fields reach strengths a thousand times stronger still, and scientists don't know the details of how they are created.
Of about 2,600 neutron stars known, to date only 29 are classified as magnetars.
The newfound nebula surrounds a magnetar known as Swift J1834.9-0846 -- J1834.9 for short -- which was discovered by NASA's Swift satellite in 2011, during a brief X-ray outburst.
"Right now, we don't know how J1834.9 developed and continues to maintain a wind nebula, which until now was a structure only seen around young pulsars," said lead researcher George Younes, postdoctoral researcher at George Washington University in Washington.
"If the process here is similar, then about 10 percent of the magnetar's rotational energy loss is powering the nebula's glow, which would be the highest efficiency ever measured in such a system," Younes said.
A month after the Swift discovery, a team led by Younes took another look at J1834.9 using the European Space Agency's (ESA) XMM-Newton X-ray observatory, which revealed an unusual lopsided glow about 15 light-years across centreed on the magnetar.
New XMM-Newton observations coupled with archival data from XMM-Newton and Swift, confirmed this extended glow as the first wind nebula ever identified around a magnetar.
A paper describing the analysis will be published in a forthcoming issue of The Astrophysical Journal.
"It represents a unique opportunity to study the magnetar's historical activity, opening a whole new playground for theorists like me," team member Jonathan Granot from Open University in Ra'anana, Israel, said.
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New York, June 22 (IANS) Older adults experience deficits in inhibition or the ability to do away with the distractions, which can affect how quickly they process information visually, say a study.
It is already known that staying on topic may be more difficult for older adults than it is for younger people because older adults begin to experience a decline in what is known as inhibition -- the ability to inhibit other thoughts in order to pursue the storyline.
The new research showed that decline in inhibition also can affect visual perception.
"There is going to be more or less competition in some of the scenes you look at over the course of the day, so the prediction is that when there is high competition, older adults will take longer to resolve -- to see -- the objects in that scene," said Mary Peterson, Professor of Psychology at University of Arizona in the US.
Inhibition is an important part of neural processing throughout the brain, and it plays a significant role in visual perception.
For example, evidence suggests that when we look at an object or a scene, our brain unconsciously considers alternative possibilities.
These competing alternatives inhibit one another, with the brain effectively weeding out the competition before perceiving what is there, Peterson explained.
With regard to vision, age-related declines in the efficiency of inhibitory processes have been demonstrated in research involving simple perception tasks, such as the ability to detect symmetry and discriminate between shapes.
Peterson and her collaborators set out to see if the same deficits are evident when it comes to more complicated visual tasks.
Their findings, published in the Journal of Vision, suggest that they are.
The findings support and further evidence that older adults experience age-related deficits in inhibition related to vision.
"This is particularly interesting as it suggests that distraction is being processed extremely rapidly, and without conscious awareness, but that older adults are less able to tolerate this ambiguity than younger adults," lead author John AE Anderson from York University in Toronto, Canada, said.
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Seoul, June 21 (IANS) Scientists have made ultra-thin photovoltaic cells flexible enough to wrap around the average pencil that could power wearable electronics like fitness trackers and smart glasses.
"Our photovoltaic is about 1 micrometre, thinner than an average human hair," said Jongho Lee, an engineer at the Gwangju Institute of Science and Technology in South Korea. Standard photovoltaics are usually hundreds of times thicker and even most other thin photovoltaics are two to four times thicker.
The researchers made the ultra-thin solar cells from the semiconductor gallium arsenide.
They stamped the cells directly onto a flexible substrate without using an adhesive that would add to the material's thickness. The cells were then "cold welded" to the electrode on the substrate.
The researchers tested the efficiency of the device at converting sunlight to electricity and found that it was comparable to similar thicker photovoltaics. They performed bending tests and found the cells could wrap around a radius as small as 1.4 millimetres.
The team also performed numerical analysis of the cells, finding that they experience one-fourth the amount of strain of similar cells that are 3.5 micrometres thick.
"The thinner cells are less fragile under bending, but perform similarly or even slightly better," Lee said in a paper published in the journal Applied Physics Letters.
These thin cells can be integrated onto glasses frames or fabric and might power the next wave of wearable electronics, Lee noted.
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New York, June 21 (IANS) Silencing a specific gene may affect human social behaviour, including a person's ability to form healthy relationships or to recognise the emotional states of others, says a study.
The scientists examined how a process known as methylation, which can reduce the expression of specific genes, affects a gene called OXT.
This gene is responsible for the production of a hormone called oxytocin, which is linked to a wide range of social behaviours in humans and other mammals.
"Methylation restricts how much a gene is expressed," said the study's lead author Brian Haas, Assistant Professor of Psychology at the University of Georgia in the US.
"An increase in methylation typically corresponds to a decrease in the expression of a gene, so it affects how much a particular gene is functioning,” Haas explained.
"When methylation increases on the OXT gene, this may correspond to a reduction in this gene's activity. Our study shows that this can have a profound impact on social behaviours," he added.
The study was published in the journal Proceedings of the National Academy of Sciences.
Haas and his collaborators collected saliva samples from more than 120 study participants to perform genetic tests that show the levels of methylation on the OXT gene.
The participants went through a battery of tests to evaluate their social skills as well as their brain structure and function.
What they found is that participants with greater methylation of the OXT gene - likely corresponding to lower levels of OXT expression - had more difficulty recognising emotional facial expressions, and they tended to have more anxiety about their relationships with loved ones.
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New York, June 21 (IANS) Children who often go hungry are more than twice as likely to develop impulse control problems and engage in violence later in life, new research has found.
Thirty-seven percent of the study's participants who had frequent hunger as children reported that they had been involved in interpersonal violence.
Of those who experienced little to no childhood hunger, 15 percent said they were involved in interpersonal violence.
Previous research has shown that childhood hunger contributes to a variety of other negative outcomes, including poor academic performance.
The current study is among the first to find a correlation between childhood hunger, low self-control and interpersonal violence.
"Good nutrition is not only critical for academic success, but now we're showing that it links to behavioral patterns. When kids start to fail in school, they start to fail in other domains of life," said Alex Piquero, Professor of Criminology at University of Texas at Dallas.
The study was published in the International Journal of Environmental Research and Public Health.
The researchers used data from the US National Epidemiologic Survey on Alcohol and Related Conditions to examine the relationship between childhood hunger, impulsivity and interpersonal violence.
Participants in that study responded to a variety of questions including how often they went hungry as a child, whether they have problems controlling their temper, and if they had physically injured another person on purpose.
The findings suggest that strategies aimed at alleviating hunger may also help reduce violence, Piquero said.
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Washington, June 21 (IANS) Using NASA's Kepler Space Telescope and its extended K2 mission, astronomers have discovered a newborn fully-formed exoplanet -- planets that orbit stars beyond our Sun -- ever detected around a young star.
The newfound planet named K2-33b is a bit larger than Neptune and whips tightly around its star every five days.
It is only five to 10 million years old, making it one of a very few newborn planets found to date.
"Our Earth is roughly 4.5 billion years old. By comparison, the planet K2-33b is very young. You might think of it as an infant," said led researcher Trevor David from California Institute of Technology (Caltech).
Astronomers have discovered and confirmed roughly 3,000 exoplanets so far. However, nearly all of them are hosted by middle-aged stars, with ages of a billion years or more.
"The newborn planet will help us better understand how planets form, which is important for understanding the processes that led to the formation of the Earth," added co-author Erik Petigura from Caltech.
The first signals of the planet's existence were measured by K2. The telescope's camera detected a periodic dimming of the light emitted by the planet's host star, a sign that an orbiting planet could be regularly passing in front of the star and blocking the light.
"Initially, this material may obscure any forming planets, but after a few million years, the dust starts to dissipate," said co-author Anne Marie Cody, a NASA postdoctoral programme fellow.
A surprising feature in the discovery of K2-33b is how close the newborn planet lies to its star. The planet is nearly 10 times closer to its star than Mercury is to our sun, making it hot.
While numerous older exoplanets were found orbiting very tightly to their stars, astronomers have long struggled to understand how more massive planets like this one wind up in such small orbits.
Some theories propose that it takes hundreds of millions of years to bring a planet from a more distant orbit into a close one and, therefore, cannot explain K2-33b which is quite a bit younger.
K2-33b could have migrated there in a process called disk migration that takes hundreds of thousands of years.
Or, the planet could have formed "in situ" -- right where it is.
The discovery of K2-33b, therefore, gives theorists a new data point to ponder.
"The question we are answering is: Did those planets take a long time to get into those hot orbits or could they have been there from a very early stage? We are saying, at least in this one case, that they can indeed be there at a very early stage," David noted in a paper appeared in the journal Nature.