Scientists in New York are reporting development of a new biodegradable nanohybrid plastic that can be engineered to decompose much faster than existing plastics used in everything from soft drink bottles to medical implants.
The plastic is a modified form of polyhydroxybutyrate (PHB), a promising biodegradable plastic produced from bacteria that has been widely hailed as a green alternative to petroleum-based plastic for use in packaging, agricultural and biomedical applications, ScienceDaily said.
Although commercially available since the 1980s, PHB has seen only limited use because of its brittleness and unpredictable biodegradation rates.
In the new study, Emmanuel P. Giannelis and colleagues compared the strength and biodegradation rates of raw PHB to a modified form of PHB that contains nanoparticles of clay or nanoclays.
The scientists found that the modified PHB was stronger and decomposed faster than regular PHB. The nanohybrid PHB decomposed almost completely after seven weeks, while its traditional counterpart showed almost no decomposition.
Researchers also showed that degradation could be fine-tuned by adjusting the amount of nanoparticles added.
The study is the “first report of the biodegradation of PHB nanocomposites“ and could lead to wider use of PHB plastics, the scientists say.

Danish researchers are reporting what appears to be a cure for a rare type of lymphoma that has been regarded as incurable until now.
A complex regimen that included immunochemotherapy produced a five-year, event-free survival rate of better than 60 percent in 159 people with mantle cell lymphoma, physicians at the Rigshospitalet in Copenhagen reported Sunday at the American Society of Hematology annual meeting, in Atlanta, according to HealthDay.
The cancer was treated with six cycles of immunochemotherapy, aimed at arousing the immune system, followed by high-dose chemotherapy with stem cell support. Of the 114 people who completed treatment, 72 percent were disease-free at five years.
The report is an outstanding example of the better long-term survival rates for various kinds of blood cancers such as lymphomas being reported at the meeting, said Dr. Ruth Winter, a professor of hematology and oncology at Northwestern University in Chicago.
“All kinds of things are happening,“ Winter said. “These are exciting times for us all.“
The advances being made “really represent a variety of different kind of approaches,“ Winter said, with no one thread running through the variety of trials being
reported.
One piece of research represents something of a challenge to standard chemotherapy by successfully using high doses of steroids for multiple myeloma, said study author Dr. S. Vincent Rajkumar, a professor of medicine at the Mayo Clinic in Rochester, Minn.
“There is a different philosophy in this trial,“ Rajkumar explained.
“Less can be more. For years, we have used the highest possible dose of steroids for multiple myeloma, but they have been a source of major morbidity for patients. This is the first trial in which the intensity of steroids that are used has been studied in a randomized way.“
Rajkumar and his colleagues used varying doses of the steroid dexamethasone along with lenalidomide, an agent that can modify and regulate action of the immune system, to treat 445 people with multiple myeloma.
One-year survival was higher in the group getting lower doses of the steroid, “96 percent survival at one year, the highest reported in any study,“ he said. A reduction in damaging side effects was one reason for the improvement, he added.
The approach is potentially applicable to other cancers, Rajkumar said. “As more and more drugs enter the picture, that kind of examination has to go on,“ he said.

First series of electric cars could arrive within five to 10 years.

German cars are known for strength, speed and high fuel consumption, but a firm in eastern Saxony has designed a lithium-ion battery membrane that could finally make electric cars common.
For years, battery-powered cars have been hampered by technological hurdles, with researchers seeking to resolve problems of weight, autonomy and ways of recharging vehicles quickly and easily, Physorg.com reported.
Recent progress towards lighter and more powerful batteries has been made however, in particular by groups like the Japanese car maker Toyota with its hybrid vehicles, and high-tech firms in France.
Germans were said to be plodding along behind, but batteries made by the a firm called Li-Tec “take up 30 percent less volume than those from Toyota“ and “allow you to go three times further for the same weight than French models,“ said Tim Schaefer, a director of the company in eastern Kamenz.
“The foundations have now been laid“ for the building of electric cars that also deliver performance, he added.
A spokesman for the German tool and auto parts company Bosch said: “It’s a step towards totally electric cars.“
Housed in a stylish rectangular silver pouch, the “Separion“ consists of two lithium electrodes in an electrolyte, or liquid conductor.
What differentiates it from similar batteries is that the electrodes are separated by a flexible ceramic membrane that provides greater thermal stability, according to the German group.
A drawback of lithium-ion batteries is a risk of explosion if they overheat.
According to Felix von Borck, director of the Akasol research center in western Darmstadt, the Separion goes a long way towards resolving that problem.
“It’s a true technological break,“ Borck said. “It is a crucial boost for the success of lithium-ion batteries.“
Li-Tec has joined a consortium that includes Bosch, chemical giant BASF and German car maker Volkswagen to develop the product, which has existed for two years.
“This is just the technology,“ von Borck said in reference to current models.
“Now someone must be found to produce them“ on an industrial scale.
Given past problems, many industrialists remain sceptical, while others are developing competing energy sources of their own like hydrogen fuel cells.
“BMW developed projects in the 1990s,“ a spokesman for the Bavarian car maker said, but concluded they were too complex to bring to the market.
“We think the first series of electric cars could arrive within five to 10 years. But its a niche market for small city cars. At any rate not ’the’ solution for questions of mobility.“

The earthÕs center is a fiery core of melted heavy metals, mostly iron.

Observations about the early formation of Earth may answer an age-old question about why the planet’s mantle is missing some of the matter that should be present, according to UBC geophysicist John Hernlund.
Earth is made from chondrite, very primitive rocks of meteorites that date from the earliest time of the solar system before the Earth was formed. However, scientists have been puzzled why the composition of Earth’s mantle and core differed from that of chondrite, ScienceDaily reported.
Hernlund’s findings suggest that an ancient magma ocean swirled beneath the Earth’s surface and would account for the discrepancy.
“As the thick melted rock cooled and crystallized, the solids that resulted had a different composition than the melt,“ explains Hernlund, a post-doctoral fellow at UBC Earth and Ocean Sciences.
“The melt held onto some of the elements. This would be where the missing elements of chondrite are stored.“
He says this layer of molten rock would have been around 1,000 km thick and 2,900 km beneath the surface.“
Published in the journal Nature, Hernlund’s study explores the melting and crystallization processes that have controlled the composition of the Earth’s interior over geological time. Co-authors are Stephane Labrosse, Ecole Normale Superieure de Lyon and Nicolas Coltice, Universite de Lyon.
The center of Earth is a fiery core of melted heavy metals, mostly iron. This represents 30 per cent while the remaining 70 per cent is the outer mantle of solid rock.
Traditional views hold that a shallow ocean of melted rock (magma) existed 1,000 km below the Earth’s surface, but it was short lived and gone by 10 million years after the formation of Earth.
In contrast, Hernlund’s evolutionary model predicts that during Earth’s hotter past shortly after its formation 4.5 billion years ago, at least one-third of the mantle closest to the core was also melted. The partially molten patches now observed at the base of the Earth’s mantle could be the remnants of such a deep magma ocean, says Hernlund.

Scientists believe they have located a new brain area essential for good memory--the “irrelevance filter“.
According to BBC, people who are good at remembering things, even with distractions, have more activity in the basal ganglia on brain scans, the Swedish team found.
The work in Nature Neuroscience could help explain why some people are better at remembering things than others.
Clinically, it could also aid the understanding of attention deficit hyperactivity disorder (ADHD).
The ability to hold information in the mind so that it is immediately accessible is known as working memory.
We use working memory all of the time--for example, when doing a simple maths calculation in our head or recalling a telephone number.
Working memory is important because it gives a mental workspace in which we can hold information whilst mentally engaged in other relevant tasks, which is crucial for learning.
Its capacity is limited and seems to vary from person to person.
These variations are not just due to having a larger or smaller memory store, but also due to differences in how effectively irrelevant items are kept out of memory, the Karolinksa Institute researchers believe.
Dr Torkel Klingberg and colleague Fiona McNab used a special brain scan called functional magnetic resonance imaging (fMRI) to track what was happening in the brains of 25 healthy volunteers.
The volunteers were asked to perform a computer-based task that required them to respond to target visual images, with or without distractions.
A noise informed subjects when an upcoming visual display would contain irrelevant distracters along with the targets.
When this cue occurred, neural activity increased in the basal ganglia and the prefrontal cortex before the visual display appeared, suggesting the brain was preparing to “filter out“ the upcoming distracters.
Also, greater activity in a specific part of the basal ganglia--the globus pallidus--correlated with less unnecessary storage in another part of the brain, the posterior parietal cortex, which is sensitive to the amount of information held in memory.
The team is currently investigating methods of improving attention and working memory in children with ADHD and monitoring any changes with fMRI.
Medical Research Council scientist John Duncan said, “This is very interesting work and gives a window on important parts of the brain.
“The basal ganglia are very strong candidates for involvement in brain disorders where people have difficulty with attentional control.
“But there will be many brain regions that filter irrelevant information, so it is too early to tell if these findings will have a bearing on conditions such as ADHD.“

Rhodiola rosea

The herbal extract of a yellow-flowered mountain plant indigenous to the Arctic regions of Europe and Asia increased the lifespan of fruit fly populations, according to a University of California, Irvine study.
Flies that ate a diet rich with Rhodiola rosea, a herbal supplement long used for its purported stress-relief effects, lived on an average of 10 percent longer than fly groups that didn’t eat the herb, Physorg.com said.
“Although this study does not present clinical evidence that Rhodiola can extend human life, the finding that it does extend the lifespan of a model organism, combined with its known health benefits in humans, make this herb a promising candidate for further anti-aging research,“ said Mahtab Jafari, a professor of pharmaceutical sciences and study leader.
“Our results reveal that Rhodiola is worthy of continued study, and we are now investigating why this herb works to increase lifespan.“
In their study, the UC Irvine researchers fed adult fruit fly populations diets supplemented at different dose levels with four herbs known for their anti-aging properties.
The herbs were mixed into a yeast paste, which adult flies ate for the duration of their lives.
Three of the herbs--known by their Chinese names as Lu Duo Wei, Bu Zhong Yi Qi Tang and San Zhi Pian--had no effect on fruit fly longevity, while Rhodiola was found to significantly reduce mortality. On average, Rhodiola increased survival 3.5 days in males and 3.2 days in females.
Rhodiola rosea, also known as the golden root, grows in cold climates at high altitudes and has been used by Scandinavians and Russians for centuries for its anti-stress qualities. The herb is thought to have anti-oxidative properties and has been widely studied.
Soviet researchers have been studying Rhodiola since the 1940s on athletes and cosmonauts, finding that the herb boosts the body’s response to stress.
And earlier this year, a Nordic Journal of Psychiatry study on people with mild-to-moderate depression showed that patients taking a Rhodiola extract called SHR-5 reported fewer symptoms of depression than did those who took a placebo.
Jafari said she is evaluating the molecular mechanism of Rhodiola by measuring its impact on energy metabolism, oxidative stress and anti-oxidant defenses in fruit flies. She is also beginning studies in mice and in mouse and human cell cultures. These latter studies should help understand the benefits of Rhodiola seen in human trials.

Confused about the right planting depth for flower bulbs? Trust the bulbs! Researchers have discovered that some flower bulbs are actually ’smart’ enough to adjust themselves to the right planting depth.
A recent study proved that bulbs can adjust their planting position by moving deeper into the ground, apparently in search of moister, more conducive growing conditions, Eurekalert reported.
According to Dr. A. Carl Leopold, William H. Crocker Scientist Emeritus at The Boyce Thompson Institute for Plant Research at Cornell University, when gardeners plant tulips or lilies too shallowly in their gardens, the bulbs will respond to the shallow conditions by literally pulling themselves down into deeper ground.
Leopold and the late Dr. Modecai Jaffe had studied plants for decades, but had never focused on bulb movement in soil. The duo was interested in working on the physiology of “contractile roots“, or those roots that are responsible for bulbs’ movement.
Explained Leopold, “Negative growth is very rare in plants, and the sort of contractile proteins that are so well known to drive contraction in animal muscles do not occur in plants. We selected this work as a divergence from the usual studies of growth, and introduced the idea of contraction.“
The study focused on the “Nelly White“ variety of Easter lily. Contractile roots were found to respond to light signals perceived by the bulb.
Exposure to certain types of blue light forced new contractile roots to be formed on the bulbs and helped initiate the remarkable bulb movement.
Further explaining the study, Leopold noted that “contraction is evidenced by a formation of epidermal wrinkles, starting at the base of the root and advancing toward the root tip.
The movement function occurs in shallowly planted materials, is lessened at deeper locations, and ceases at a vermiculite depth of 15 centimeters.
Movement of the bulb in the soil is achieved by a hydraulic shift in cortical cells. Root contraction is stimulated by light.“
The research team documented that perception of the light stimulus occurred in the bulblet or the subtending leaf. They also found that responsiveness to light faded as the roots aged.