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Artificial membranes form bio-silicon interfaces

Artificial membranes form bio-silicon interfaces | naif | Scoop.it

A group of scientists in Chile has created* artificial biomembranes, mimicking those found in living organisms on silicon surfaces, a step toward creating bio-silicon interfaces, where biological “sensor” molecules can be printed onto a cheap silicon chip with integrated electronic circuits.

 

Described in The Journal of Chemical Physics from AIP Publishing, the artificial membranes have potential applications such as detecting bacterial contaminants in food, toxic pollution in the environment, and dangerous diseases .

 

The idea is to create a “biosensor that can transmit electrical signals through the membrane,” said María José Retamal, a Ph.D. student at Pontificia Universidad Católica de Chile and first author of the paper.

 

Lipid membranes separate distinct spaces within cells and define walls between neighboring cells — a functional compartmentalization that serves many physiological processes, protecting genetic material, regulating what comes in and out of cells, and maintaining the function of separate organs.

 

Synthetic membranes that mimic nature offer the possibility of containing membrane proteins — biological molecules that could be used for detecting toxins, diseases and many other biosensing applications.

 

More work is needed to standardize the process by which proteins are to be inserted in the membranes, to define the mechanism by which an electrical signal would be transmitted when a protein binds its target, and to calibrate how that signal is detected by the underlying circuitry, Retamal said.

 

* Retamal and her colleagues created the first artificial membrane without using solvents on a silicon support base. They chose silicon because of its low cost, wide availability and because its “hydrophobicity” (how much it repels water) can be controlled chemically, allowing them to build membranes on top.

Next they evaporated a chemical known as chitosan onto the silicon. Chitosan is derived from chitin, a sugar found in the shells of certain crustaceans, like lobsters or shrimp. Whole bags of the powder can be bought from chemical companies worldwide. They chose this ingredient for its ability to form a moisturizing matrix. It is insoluble in water, but chitosan is porous, so it is capable of retaining water.

Finally they evaporated a phospholipid molecule known as dipalmitoylphosphatidylcholine (DPPC) onto the chitosan-covered silicon substrate and showed that it formed a stable “bilayer,” the classic form of a membrane. Spectroscopy showed that these artificial membranes were stable over a wide range of temperatures.


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Artificial spleen cleans up blood: Device improves survival in rats after severe infections

Artificial spleen cleans up blood: Device improves survival in rats after severe infections | naif | Scoop.it
Researchers have developed a high-tech method to rid the body of infections — even those caused by unknown pathogens. A device inspired by the spleen can quickly clean blood of everything from Escherichia coli to Ebola, researchers report on 14 September in Nature Medicine1.The device uses a modified version of mannose-binding lectin (MBL), a protein found in humans that binds to sugar molecules on the surfaces of more than 90 different bacteria, viruses and fungi, as well as to the toxins released by dead bacteria that trigger the immune overreaction in sepsis.The researchers coated magnetic nanobeads with MBL. As blood enters the biospleen device, passes by the MBL-equipped nanobeads, which bind to most pathogens. A magnet on the biospleen device then pulls the beads and their quarry out of the blood, which can then be routed back into the patient.To test the device, Ingber and his team infected rats with either E. coli or Staphylococcus aureus and filtered blood from some of the animals through the biospleen. Five hours after infection, 89% of the rats whose blood had been filtered were still alive, compared with only 14% of those that were infected but not treated. The researchers found that the device had removed more than 90% of the bacteria from the rats' blood. The rats whose blood had been filtered also had less inflammation in their lungs and other organs, suggesting they would be less prone to sepsis.The researchers then tested whether the biospleen could handle the volume of blood in an average adult human — about 5 liters. They ran human blood containing a mixture of bacteria and fungi through the biospleen at a rate of 1 litre per hour, and found that the device removed most of the pathogens within five hours.
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Anne Pascucci, MPA, CRA's curator insight, September 15, 10:54 AM

"Inspired by the spleen" Gotta be the first time in history those words were put together!

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Woman of 24 found to have no cerebellum in her brain

Woman of 24 found to have no cerebellum in her brain | naif | Scoop.it
A 24-year-old woman has discovered that her cerebellum is completely missing, explaining some of the unusual problems she has had with movement and speech. The case highlights just how adaptable the organ is.The discovery was made when the woman was admitted to the Chinese PLA General Hospital of Jinan Military Area Command in Shandong Province complaining of dizziness and nausea. She told doctors she'd had problems walking steadily for most of her life, and her mother reported that she hadn't walked until she was 7 and that her speech only became intelligible at the age of 6.Doctors did a CAT scan and immediately identified the source of the problem – her entire cerebellum was missing (see scan, below left). The space where it should be was empty of tissue. Instead it was filled with cerebrospinal fluid, which cushions the brain and provides defence against disease.The cerebellum – sometimes known as the "little brain" – is located underneath the two hemispheres. It looks different from the rest of the brain because it consists of much smaller and more compact folds of tissue. It represents about 10 per cent of the brain's total volume but contains 50 per cent of its neurons.Although it is not unheard of to have part of your brain missing, either congenitally or from surgery, the woman joins an elite club of just nine people who are known to have lived without their entire cerebellum. A detailed description of how the disorder affects a living adult is almost non-existent, say doctors from the Chinese hospital, because most people with the condition die at a young age and the problem is only discovered on autopsy (Brain,doi.org/vh7).The cerebellum's main job is to control voluntary movements and balance, and it is also thought to be involved in our ability to learn specific motor actions and speak. Problems in the cerebellum can lead to severe mental impairment, movement disorders, epilepsy or a potentially fatal build-up of fluid in the brain. However, in this woman, the missing cerebellum resulted in only mild to moderate motor deficiency, and mild speech problems such as slightly slurred pronunciation. Her doctors describe these effects as "less than would be expected", and say her case highlights the remarkable plasticity of the brain.
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Lactic acid bacteria from the honey bees could be the source for efficient treatment of MRSA

Lactic acid bacteria from the honey bees could be the source for efficient treatment of MRSA | naif | Scoop.it
Could honeybees' most valuable contribution to mankind besides pollination services be alternative tools against infections? Today, due to the emerging antibiotic-resistant pathogens, we are facing a new era of searching for alternative tools against infections. Natural products such as honey have been applied against human's infections for millennia without sufficient scientific evidence. A unique lactic acid bacterial (LAB) microbiota was discovered by us, which is in symbiosis with honeybees and present in large amounts in fresh honey across the world. This work investigates if the LAB symbionts are the source to the unknown factors contributing to honey's properties.Hence, a group of researchers at Lund University have tested the LAB against severe wound pathogens such as methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa and vancomycin-resistant Enterococcus (VRE) among others. They were able to demonstrate a strong antimicrobial activity from each symbiont and a synergistic effect, which counteracted all the tested pathogens. The mechanisms of action are partly shown by elucidating the production of active compounds such as proteins, fatty acids, anaesthetics, organic acids, volatiles and hydrogen peroxide. The team showed that the symbionts produce a myriad of active compounds that remain in variable amounts in mature honey. Further studies are now required to investigate if these symbionts have a potential in clinical applications as alternative tools against topical human and animal infections."Antibiotics are mostly one active substance, effective against only a narrow spectrum of bacteria. When used alive, these 13 lactic acid bacteria produce the right kind of antimicrobial compounds as needed, depending on the threat. It seems to have worked well for millions of years of protecting bees' health and honey against other harmful microorganisms. However, since store-bought honey doesn't contain the living lactic acid bacteria, many of its unique properties have been lost in recent times", explains Tobias Olofsson.The next step is further studies to investigate wider clinical use against topical human infections as well as on animals. The findings have implications for developing countries, where fresh honey is easily available, but also for Western countries where antibiotic resistance is seriously increasing.Reference: Lactic acid bacterial symbionts in honeybees – an unknown key to honey's antimicrobial and therapeutic activities
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New invisible ink: Stretchy plastics hide secret pictures

New invisible ink: Stretchy plastics hide secret pictures | naif | Scoop.it
A new invisible ink that reveals secret messages when squeezed could be useful in preventing fraud.It could be the ultimate stress ball for spies. An invisible ink creates secret messages on bendy plastic that are only revealed when you give it a squeeze.Previously, Jianping Ge of the East China Normal University in Shanghai, China, and his colleagues created invisible inks that appear when submerged underwater or exposed to a magnetic field. Now they've made an ink you can reveal just by squeezing with your hand. The team first embedded an array of silica crystals in a plastic gel. The crystals reflect light at a certain wavelength depending on their spacing and the angle of viewing, so the relaxed gel appears green, but squeezing or stretching it turns it red or blue.Next, the team coated the surface with another clear plastic gel, and put a cut-out template of a secret image on top. They shone ultraviolet light on the set-up, which linked the two gels around the cut-out, but left them separate in the parts covered by the template. The linked gels are firmer, so they don't change colours when squeezed. After the cut-out was removed, its silhouette only appeared when the gels were squeezed.Ge says he is talking to companies about using the technique to protect against counterfeit goods. "These invisible photonic patterns can be potential anti-fake labels," he says. Jon Kellar, a materials engineer at the South Dakota School of Mines and Technology in Rapid City, South Dakota, agrees that the hidden images could help combat fraud, but he thinks that the fabrication process will need to be simplified for commercial use.
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How lizards regenerate their tails: researchers discover genetic 'recipe'

How lizards regenerate their tails: researchers discover genetic 'recipe' | naif | Scoop.it
By understanding the secret of how lizards regenerate their tails, researchers may be able to develop ways to stimulate the regeneration of limbs in humans. Now, a team of researchers from Arizona State University is one step closer to solving that mystery. The scientists have discovered the genetic “recipe” for lizard tail regeneration, which may come down to using genetic ingredients in just the right mixture and amounts.Other animals, such as salamanders, frog tadpoles and fish, can also regenerate their tails, with growth mostly at the tip. During tail regeneration, they all turn on genes in what is called the 'Wnt pathway’ – a process that is required to control stem cells in many organs, such as the brain, hair follicles and blood vessels. However, lizards have a unique pattern of tissue growth that is distributed throughout the tail."Regeneration is not an instant process," said Elizabeth Hutchins, a graduate student in ASU's molecular and cellular biology program and co-author of the paper. "In fact, it takes lizards more than 60 days to regenerate a functional tail. Lizards form a complex regenerating structure with cells growing into tissues at a number of sites along the tail.”"We have identified one type of cell that is important for tissue regeneration," said Jeanne Wilson-Rawls, co-author and associate professor with ASU’s School of Life Sciences. "Just like in mice and humans, lizards have satellite cells that can grow and develop into skeletal muscle and other tissues.""Using next-generation technologies to sequence all the genes expressed during regeneration, we have unlocked the mystery of what genes are needed to regrow the lizard tail," said Kusumi. "By following the genetic recipe for regeneration that is found in lizards, and then harnessing those same genes in human cells, it may be possible to regrow new cartilage, muscle or even spinal cord in the future."The findings are published today in the journal PLOS ONE.
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Plants may use RNA language to communicate with each other, Virginia Tech researcher finds

Plants may use RNA language to communicate with each other, Virginia Tech researcher finds | naif | Scoop.it
A Virginia Tech scientist has discovered a potentially new form of plant communication, one that allows them to share an extraordinary amount of genetic information with one another. The finding by Jim Westwood, a professor of plant pathology, physiology, and weed science in the College of Agriculture and Life Sciences, throws open the door to a new arena of science that explores how plants communicate with each other on a molecular level. It also gives scientists new insight into ways to fight parasitic weeds that wreak havoc on food crops in some of the poorest parts of the world. His findings were published on Aug. 15 in the journal Science.“The discovery of this novel form of inter-organism communication shows that this is happening a lot more than any one has previously realized,” said Westwood, who is an affiliated researcher with the Fralin Life Science Institute. “Now that we have found that they are sharing all this information, the next question is, ‘What exactly are they telling each other?’.” Westwood examined the relationship between a parasitic plant, dodder, and two host plants, Arabidopsis and tomatoes. In order to suck the moisture and nutrients out the host plants, dodder uses an appendage called a haustorium to penetrate the plant. Westwood previously broke new ground when he found that during this parasitic interaction, there is a transport of RNA between the two species. RNA translates information passed down from DNA, which is an organism’s blueprint. His new work expands this scope of this exchange and examines the mRNA, or messenger RNA, which sends messages within cells telling them which actions to take, such as which proteins to code. It was thought that mRNA was very fragile and short-lived, so transferring it between species was unimaginable. But Westwood found that during this parasitic relationship, thousands upon thousands of mRNA molecules were being exchanged between both plants, creating this open dialogue between the species that allows them to freely communicate. Through this exchange, the parasitic plants may be dictating what the host plant should do, such as lowering its defenses so that the parasitic plant can more easily attack it. Westwood’s next project is aimed at finding out exactly what the mRNA are saying.“Parasitic plants such as witchweed and broomrape are serious problems for legumes and other crops that help feed some of the poorest regions in Africa and elsewhere,” said Julie Scholes, a professor at the University of Sheffield, U.K., who is familiar with Westwood’s work but was not part of this project. “In addition to shedding new light on host-parasite communication, Westwood’s findings have exciting implications for the design of novel control strategies based on disrupting the mRNA information that the parasite uses to reprogram the host."
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NASA: Jupiter's Great Red Spot is Rapidly Shrinking

NASA: Jupiter's Great Red Spot is Rapidly Shrinking | naif | Scoop.it
New observations from the Hubble Space Telescope confirm that Jupiter's Great Red Spot is rapidly shrinking. The behemoth storm is now at its smallest size ever measured. According to Amy Simon of NASA's Goddard Space Flight Center in Greenbelt, Maryland, recent NASA Hubble Space Telescope observations confirm the Great Red Spot now is approximately 10,250 miles across, less than half the size of some historical measurements. Astronomers have followed this downsizing since the 1930s.Historic observations as far back as the late 1800s gauged the storm to be as large as 25,500 miles on its long axis. NASA Voyager 1 and Voyager 2 flybys of Jupiter in 1979 measured it to be 14,500 miles across. In 1995, a Hubble photo showed the long axis of the spot at an estimated 13,020 miles across. And in a 2009 photo, it was measured at 11,130 miles across. Beginning in 2012, amateur observations revealed a noticeable increase in the rate at which the spot is shrinking -- by 580 miles per year -- changing its shape from an oval to a circle."In our new observations it is apparent very small eddies are feeding into the storm," said Simon. "We hypothesized these may be responsible for the accelerated change by altering the internal dynamics and energy of the Great Red Spot."Simon's team plans to study the motions of the small eddies and the internal dynamics of the storm to determine whether these eddies can feed or sap momentum entering the upwelling vortex, resulting in this yet unexplained shrinkage.NASA's Juno spacecraft is hurtling toward Jupiter now, due to reach the giant planet in July 2016. Point-blank examination by Juno's instruments will undoubtedly help unravel the mystery.
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TESS: The First-Ever Spaceborne All-Sky Transiting Exoplanet Survey Satellite Will Be Launched 2017

TESS: The First-Ever Spaceborne All-Sky Transiting Exoplanet Survey Satellite Will Be Launched 2017 | naif | Scoop.it
The Transiting Exoplanet Survey Satellite (TESS) is an Explorer-class planet finder. In the first-ever spaceborne all-sky transit survey, TESS will identify planets ranging from Earth-sized to gas giants, orbiting a wide range of stellar types and orbital distances. The principal goal of the TESS mission is to detect small planets with bright host stars in the solar neighborhood, so that detailed characterizations of the planets and their atmospheres can be performed.TESS will monitor the brightness of more than 500,000 stars during a two year mission, searching for temporary drops in brightness caused by planetary transits. Transits occur when a planet’s orbit carries it directly in front of its parent star as viewed from Earth. TESS is expected to catalog more than 3000 transiting exoplanet candidates, including a sample of ~500 Earth-sized and ‘Super Earth’ planets, with radii less than twice that of the Earth. TESS will detect small rock-and-ice planets orbiting a diverse range of stellar types and covering a wide span of orbital periods, including rocky worlds in the habitable zones of their host stars.TESS stars will be 30-100 times brighter than those surveyed by the Kepler satellite; thus,TESS planets should be far easier to characterize with follow-up observations. These follow-up observations will provide refined measurements of the planet masses, sizes, densities, and atmospheric properties.TESS will provide prime targets for further, more detailed characterization with the James Webb Space Telescope (JWST), as well as other large ground-based and space-based telescopes of the future. TESS's legacy will be a catalog of the nearest and brightest stars hosting transiting exoplanets, which will comprise the most favorable targets for detailed investigations in the coming decades.TESS team partners include the MIT Kavli Institute for Astrophysics and Space Research (MKI) and MIT Lincoln Laboratory; NASA’s Goddard Spaceflight Center; Orbital Sciences Corporation; NASA’s Ames Research Center; the Harvard-Smithsonian Center for Astrophysics; the Aerospace Corporation; and the Space Telescope Science Institute. TESS has been selected by NASA for launch in 2017 as an Astrophysics Explorer mission.
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Driverless cars to hit UK roads next year

Driverless cars to hit UK roads next year | naif | Scoop.it
Driverless cars are an exciting glimpse of the future, with great potential to improve road safety. It seems the UK has caught on to this, announcing a £10 million (US$17 million) scheme to test driverless cars on public roads from January 2015.The UK Government is calling on all major cities to join together with businesses and research organizations to put forward a proposal for the country to become a test location for autonomous cars. Trials are expected to last between 18 and 36 months, and the £10 million funding pot will serve as a competition prize for up to three UK cities, with London being confirmed as a hopeful bid.Currently, self-driving cars are only allowed on private roads in the UK, but the new scheme will allow for the testing of fully autonomous vehicles on public roads, as well as cars with self-driving features."Driverless cars have huge potential to transform the UK’s transport network – they could improve safety, reduce congestion and lower emissions, particularly CO2," said the UK’s Transport Minister, Claire Perry.Driverless cars have been coming for some time, with manufacturers including Audi, BMW, Mercedes, Toyota, Ford and Volvo all working on the technology. Jaguar also recently previewed its self-learning smart car which can mimic a driver's behavior.Nissan recently carried out the first public road test of a driverless car on a Japanese highway, and has said it plans to be manufacturing driverless carsby 2020. Meanwhile, several states in the US have already passed legislation which will allow driverless cars, including California, Nevada and Florida.Much of the limelight has centered on Google thus far; its driverless car has completed 804,000 km (500,000 miles) of road tests. The technology giant has set 2017 as the date its cars will hit the roads."Britain is brilliantly placed to lead the world in driverless technology. It combines our strengths in cars, satellites, big data and urban design; with huge potential benefits for future jobs and for the consumer," said Science Minister Greg Clark.

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Marco Bertolini's curator insight, August 7, 11:09 AM

Des voitures sans chauffeur au Royaume Uni dès l'an prochain !


Eric Chan Wei Chiang's curator insight, August 8, 7:01 PM

Google isn't the only one working on a driverless car. However, they would be the most ambitious and perhaps the only company which could imagine digitizing all the surface streets of the United States as a key part of the solution of self-driving cars. Read more about it here: http://sco.lt/5XGlH7

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New material combines two semiconductor sheets three atomic layers thick to create ultra-thin solar cells

New material combines two semiconductor sheets three atomic layers thick to create ultra-thin solar cells | naif | Scoop.it

Semiconductor heterostructures form the cornerstone of many electronic and optoelectronic devices and are traditionally fabricated using epitaxial growth techniques. More recently, heterostructures have also been obtained by vertical stacking of two-dimensional crystals, such as graphene and related two-dimensional materials. These layered designer materials are held together by van der Waals forces and contain atomically sharp interfaces. Here, we report on a type-II van der Waals heterojunction made of molybdenum disulfide and tungsten diselenide monolayers. The junction is electrically tunable, and under appropriate gate bias an atomically thin diode is realized. Upon optical illumination, charge transfer occurs across the planar interface and the device exhibits a photovoltaic effect. Advances in large-scale production of two-dimensional crystals could thus lead to a new photovoltaic solar technology.


Tungsten diselenide is a semiconductor which consists of three atomic layers. One layer of tungsten is sandwiched between two layers of selenium atoms. “We had already been able to show that tungsten diselenide can be used to turn light into electric energy and vice versa”, says Thomas Mueller. But a solar cell made only of tungsten diselenide would require countless tiny metal electrodes tightly spaced only a few micrometers apart. If the material is combined with molybdenium disulphide, which also consists of three atomic layers, this problem is elegantly circumvented. The heterostructure can now be used to build large-area solar cells. 

When light shines on a photoactive material single electrons are removed from their original position. A positively charged hole remains, where the electron used to be. Both the electron and the hole can move freely in the material, but they only contribute to the electrical current when they are kept apart so that they cannot recombine. 

To prevent recombination of electrons and holes, metallic electrodes can be used, through which the charge is sucked away - or a second material is added. “The holes move inside the tungsten diselenide layer, the electrons, on the other hand, migrate into the molybednium disulphide”, says Thomas Mueller. Thus, recombination is suppressed.

This is only possible if the energies of the electrons in both layers are tuned exactly the right way. In the experiment, this can be done using electrostatic fields. Florian Libisch and Professor Joachim Burgdörfer (TU Vienna) provided computer simulations to calculate how the energy of the electrons changes in both materials and which voltage leads to an optimum yield of electrical power.


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Companion planets and large moons can increase an exoplanet's chance harbouring life

Companion planets and large moons can increase an exoplanet's chance harbouring life | naif | Scoop.it
Having a companion in old age is good for people — and, it turns out, might extend the chance for life on certain Earth-sized planets in the cosmos as well. Planets cool as they age. Over time their molten cores solidify and inner heat-generating activity dwindles, becoming less able to keep the world habitable by regulating carbon dioxide to prevent runaway heating or cooling.But astronomers at the University of Washington and the University of Arizona have found that for certain planets about the size of our own, the gravitational pull of an outer companion planet could generate enough heat — through a process called tidal heating — to effectively prevent that internal cooling, and extend the inner world’s chance at hosting life.UW astronomer Rory Barnes is second author of a paper published in the July issue of the Monthly Notices of the Royal Astronomical Society. The lead authors are graduate student Christa Van Laerhoven and planetary scientist Richard Greenberg at the University of Arizona.Tidal heating results from the gravitational push and pull of the outer companion planet on its closer-in neighbor, Barnes said. The effect happens locally, so to speak, on Jupiter’s moons Io and Europa. The researchers showed that this phenomenon can take place on exoplanets — those outside the solar system — as well.Using computer models, the researchers found the effect can occur on older Earth-sized planets in noncircular orbits in the habitable zone of low-mass stars, or those less than one-quarter the mass of the Sun. The habitable zone is that swath of space around a star just right to allow an orbiting rocky planet to sustain liquid water on its surface, thus giving life a chance.“When the planet is closer to the star, the gravitational field is stronger and the planet is deformed into an American football shape. When farther from the star, the field is weaker and the planet relaxes into a more spherical shape,” Barnes said. “This constant flexing causes layers inside the planet to rub against each other, producing frictional heating.”The outer planet is necessary, Barnes added, to keep the potentially habitable planet’s orbit noncircular. When a planet’s orbit is circular, the gravitational pull from its host star is constant, so its shape never changes, and there is no tidal heating.And so, the researchers conclude, any discoveries of Earth-sized planets in the habitable zone of old, small stars should be followed by searches for outer companion planets that might improve the inner world’s chance at hosting life.
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Weighing the Milky Way: Researchers devise precise method for calculating the mass of galaxies

Weighing the Milky Way: Researchers devise precise method for calculating the mass of galaxies | naif | Scoop.it
Does the Milky Way look fat in this picture? Has Andromeda been taking skinny selfies? Using a new, more accurate method for measuring the mass of galaxies, and international group of researchers has shown that the Milky Way has only half the Mass of the Andromeda Galaxy.In previous studies, researchers were only able to estimate the mass of the Milky Way and Andromeda based on observations made using their smaller satellite dwarf galaxies. In the new study, researchers culled previously published data that contained information about the distances between the Milky Way, Andromeda and other close-by galaxies -- including those that weren't satellites -- that reside in and right outside an area referred to as the Local Group.Galaxies in the Local Group are bound together by their collective gravity. As a result, while most galaxies, including those on the outskirts of the Local Group, are moving farther apart due to expansion, the galaxies in the Local Group are moving closer together because of gravity. For the first time, researchers were able to combine the available information about gravity and expansion to complete precise calculations of the masses of both the Milky Way and Andromeda."Historically, estimations of the Milky Way's mass have been all over the map," said Walker, an assistant professor of physics at Carnegie Mellon. "By studying two massive galaxies that are close to each other and the galaxies that surround them, we can take what we know about gravity and pair that with what we know about expansion to get an accurate account of the mass contained in each galaxy. This is the first time we've been able to measure these two things simultaneously."By studying both the galaxies in and immediately outside the Local Group, Walker was able to pinpoint the group's center. The researchers then calculated the mass of both the ordinary, visible matter and the invisible dark matter throughout both galaxies based on each galaxy's present location within the Local Group. Andromeda had twice as much mass as the Milky Way, and in both galaxies 90 percent of the mass was made up of dark matter.The study was supported by the UK's Science and Technology Facilities Council and led by Jorge Peñarrubia of the University of Edinburgh's School of Physics and Astronomy. Co-authors include Yin-Zhe Ma of the University of British Columbia and Alan McConnachie of the NRC Herzberg Institute of Astrophysics.Carnegie Mellon University. "Weighing the Milky Way: Researchers devise precise method for calculating the mass of galaxies."
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Artificial membranes form bio-silicon interfaces

Artificial membranes form bio-silicon interfaces | naif | Scoop.it

A group of scientists in Chile has created* artificial biomembranes, mimicking those found in living organisms on silicon surfaces, a step toward creating bio-silicon interfaces, where biological “sensor” molecules can be printed onto a cheap silicon chip with integrated electronic circuits.

 

Described in The Journal of Chemical Physics from AIP Publishing, the artificial membranes have potential applications such as detecting bacterial contaminants in food, toxic pollution in the environment, and dangerous diseases .

 

The idea is to create a “biosensor that can transmit electrical signals through the membrane,” said María José Retamal, a Ph.D. student at Pontificia Universidad Católica de Chile and first author of the paper.

 

Lipid membranes separate distinct spaces within cells and define walls between neighboring cells — a functional compartmentalization that serves many physiological processes, protecting genetic material, regulating what comes in and out of cells, and maintaining the function of separate organs.

 

Synthetic membranes that mimic nature offer the possibility of containing membrane proteins — biological molecules that could be used for detecting toxins, diseases and many other biosensing applications.

 

More work is needed to standardize the process by which proteins are to be inserted in the membranes, to define the mechanism by which an electrical signal would be transmitted when a protein binds its target, and to calibrate how that signal is detected by the underlying circuitry, Retamal said.

 

* Retamal and her colleagues created the first artificial membrane without using solvents on a silicon support base. They chose silicon because of its low cost, wide availability and because its “hydrophobicity” (how much it repels water) can be controlled chemically, allowing them to build membranes on top.

Next they evaporated a chemical known as chitosan onto the silicon. Chitosan is derived from chitin, a sugar found in the shells of certain crustaceans, like lobsters or shrimp. Whole bags of the powder can be bought from chemical companies worldwide. They chose this ingredient for its ability to form a moisturizing matrix. It is insoluble in water, but chitosan is porous, so it is capable of retaining water.

Finally they evaporated a phospholipid molecule known as dipalmitoylphosphatidylcholine (DPPC) onto the chitosan-covered silicon substrate and showed that it formed a stable “bilayer,” the classic form of a membrane. Spectroscopy showed that these artificial membranes were stable over a wide range of temperatures.


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Microscopic Diamonds Suggest Cosmic Impact Responsible for Younger Dryas Climate Change 12,800 Years Ago

Microscopic Diamonds Suggest Cosmic Impact Responsible for Younger Dryas Climate Change 12,800 Years Ago | naif | Scoop.it
A new study published in The Journal of Geology provides support for the theory that a cosmic impact event over North America some 13,000 years ago caused a major period of climate change known as the Younger Dryas stadial, or “Big Freeze.” Around 12,800 years ago, a sudden, catastrophic event plunged much of the Earth into a period of cold climatic conditions and drought. This drastic climate change—the Younger Dryas—coincided with the extinction of Pleistocene megafauna, such as the saber-tooth cats and the mastodon, and resulted in major declines in prehistoric human populations, including the termination of the Clovis culture. With limited evidence, several rival theories have been proposed about the event that sparked this period, such as a collapse of the North American ice sheets, a major volcanic eruption, or a solar flare. However, in a study published in The Journal of Geology, an international group of scientists analyzing existing and new evidence have determined a cosmic impact event, such as a comet or meteorite, to be the only plausible hypothesis to explain all the unusual occurrences at the onset of the Younger Dryas period. Researchers from 21 universities in 6 countries believe the key to the mystery of the Big Freeze lies in nanodiamonds scattered across Europe, North America, and portions of South America, in a 50-million-square-kilometer area known as the Younger Dryas Boundary (YDB) field. Microscopic nanodiamonds, melt-glass, carbon spherules, and other high-temperature materials are found in abundance throughout the YDB field, in a thin layer located only meters from the Earth’s surface. Because these materials formed at temperatures in excess of 2200 degrees Celsius, the fact they are present together so near to the surface suggests they were likely created by a major extraterrestrial impact event. In addition to providing support for the cosmic impact event hypothesis, the study also offers evidence to reject alternate hypotheses for the formation of the YDB nanodiamonds, such as by wildfires, volcanism, or meteoric flux. The team’s findings serve to settle the debate about the presence of nanodiamonds in the YDB field and challenge existing paradigms across multiple disciplines, including impact dynamics, archaeology, paleontology, limnology, and palynology.
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Bernhard H. Schmitz's curator insight, September 16, 3:33 AM

And where is the center of the YDB field?

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Flies live 30 percent longer when AMPK is activated

Flies live 30 percent longer when AMPK is activated | naif | Scoop.it
Activating a specific gene in the intestines of a fruit fly made it live 30 percent longer, a team of biologists has reported.The gene in question, AMPK, detects and reacts to fluctuations in the body to help modulate energy levels. The gene is also found in humans in low levels, leading the UCLA team to postulate in the open source journal Cell Reports that we could use it to learn about potentially delaying the ageing process.Key to this statement is the fact that in the experiment on the Drosophila melanogaster fruit fly, the ageing process slowed throughout the insect's organs -- not just in the intestine where AMPK was activated.The team behind the study is taking an approach similar to that ofbiogerontologist and SENS Foundation co-founder Aubrey de Grey, who argues that instead of attempting to modify our cells to combat disease, we must repair the molecular damage that happens as cells degrade. Among the cell death, cell divisions and mitochondria mutations that he cites as being cellular problems to combat, is "molecular garbage", a problem also flagged up by the UCLA team. In the body, we naturally discard of this molecular garbage through a process known as autophagy.Autophagy allows any cells that are old or degrading to be shed, and AMPK is known to help activate that system. "However, the tissue-specific mechanisms involved are poorly understood," writes the UCLA team in Cell Reports. If we could better understand and harness its capabilities, they argue, we could go some way in slowing the aging process by tackling the molecular garbage problem prevalent in old age. It is molecular garbage and protein buildups that contribute to some of the biggest killer diseases in later years.
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Proprane-producing E. coli provide biosynthetic alternative to fossil fuels

Proprane-producing E. coli provide biosynthetic alternative to fossil fuels | naif | Scoop.it

Propane is an appealing fuel, easily stored and already used worldwide, but it’s extracted from the finite supply of fossil fuels – or is it? Researchers at Imperial College London and the University of Turku have engineered E. coli bacteria that create engine-ready propane out of fatty acids, and in the future, maybe even sunlight.

 

When considering the bioproduction of fuels, the researchers looked at the alternatives. Propane is cheaper and easier to condense into liquid than other available gaseous fuels, such as hydrogen. And it’s arguably a better synthetic candidate than liquid fuels which can be detrimental to their living bacterial factories and require purification from the host once produced.

 

With the premise of producing a fuel that’s more sustainable in a biological host and easier to bring to market, the research team engineered a pathway in E. coli that interrupts the conversion of fatty acids into cell membranes and instead couples naturally unlinked enzymatic processes to manufacture propane.

 

The recently discovered enzyme aldehyde-deformylating oxygenase (ADO) excited scientists because it provided a catalytic step for the production of hydrocarbons, such as propane, but until now hadn’t been successfully manipulated into a synthetic pathway. In this experiment, researchers amped up the catalyzing power of the enzyme by providing extra electrons to the reaction in the form of reducing agents normally present in photosynthetic organisms (E. coli is not photosynthetic; however, cyanobacteria are).


The bacteria were housed in crimped glass tubes to be able to measure the end products for analysis, and as such, there wasn’t a lot of room for storing the propane end product or controlling the concentration of oxygen. Indeed, the researchers observed that with larger vessels and an increased volume of liquid, the propane production continued for up to six times as long, with a two orders of magnitude increase in propane production.


"Although this research is at a very early stage, our proof of concept study provides a method for renewable production of a fuel that previously was only accessible from fossil reserves," said Dr Patrik Jones, from the Department of Life Sciences at Imperial College London. "Although we have only produced tiny amounts so far, the fuel we have produced is ready to be used in an engine straight away. This opens up possibilities for future sustainable production of renewable fuels that at first could complement, and thereafter replace fossil fuels like diesel, petrol, natural gas and jet fuel."


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Deb Nystrom, REVELN's curator insight, September 4, 2:42 PM

The tiniest amount of a new discovery can end up fueling, literally, a whole new world.  A new industry was started by Andrew Carnegie based on what was then extraordinarily expensive steel to build the 1874  Eads Bridge, the longest arch bridge in the world.  ~  D

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Mystery solved: 'Sailing stones' of death valley seen in action for the first time

Mystery solved: 'Sailing stones' of death valley seen in action for the first time | naif | Scoop.it
Racetrack Playa is home to an enduring Death Valley mystery. Littered across the surface of this dry lake, also called a "playa," are hundreds of rocks – some weighing as much as 320 kilograms (700 pounds) – that seem to have been dragged across the ground, leaving synchronized trails that can stretch for hundreds of meters.What powerful force could be moving them? Researchers have investigated this question since the 1940s, but no one has seen the process in action – until now. In a paper published in the journal PLOS ONE on Aug. 27, a team led by Scripps Institution of Oceanography, UC San Diego, paleobiologist Richard Norris reports on first-hand observations of the phenomenon.Because the stones can sit for a decade or more without moving, the researchers did not originally expect to see motion in person. Instead, they decided to monitor the rocks remotely by installing a high-resolution weather station capable of measuring gusts to one-second intervals and fitting 15 rocks with custom-built, motion-activated GPS units. The National Park Service would not let them use native rocks, so they brought in similar rocks from an outside source.The experiment was set up in winter 2011 with permission of the Park Service. Then – in what Ralph Lorenz of the Applied Physics Laboratory at the Johns Hopkins University, one of the paper's authors, suspected would be "the most boring experiment ever" – they waited for something to happen.But in December 2013, Norris and co-author and cousin Jim Norris arrived in Death Valley to discover that the playa was covered with a pond of water seven centimeters (three inches) deep. Shortly after, the rocks began moving."Science sometimes has an element of luck," Richard Norris said. "We expected to wait five or ten years without anything moving, but only two years into the project, we just happened to be there at the right time to see it happen in person."Their observations show that moving the rocks requires a rare combination of events. First, the playa fills with water, which must be deep enough to form floating ice during cold winter nights but shallow enough to expose the rocks. As nighttime temperatures plummet, the pond freezes to form thin sheets of "windowpane" ice, which must be thin enough to move freely but thick enough to maintain strength. On sunny days, the ice begins to melt and break up into large floating panels, which light winds drive across the playa, pushing rocks in front of them and leaving trails in the soft mud below the surface."On Dec. 21, 2013, ice breakup happened just around noon, with popping and cracking sounds coming from all over the frozen pond surface," said Richard Norris. "I said to Jim, 'This is it!'"
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More than just X and Y: miRNAs are responsible for sexual differences in fruit flies

More than just X and Y: miRNAs are responsible for sexual differences in fruit flies | naif | Scoop.it
Men and women differ in plenty of obvious ways, and scientists have long known that genetic differences buried deep within our DNA underlie these distinctions. In the past, most research has focused on understanding how the genes that encode proteins act as sex determinants. But Cold Spring Harbor Laboratory (CSHL) scientists have found that a subset of very small genes encoding short RNA molecules, called microRNAs (miRNAs), also play a key role in differentiating male and female tissues in the fruit fly.A miRNA is a short segment of RNA that fine-tunes the activation of one or several protein-coding genes. miRNAs are able to silence the genes they target and, in doing so, orchestrate complex genetic programs that are the basis of development.In work published in Genetics, a team of CSHL researchers and colleagues describe how miRNAs contribute to sexual differences in fruit flies. You've probably never noticed, but male and female flies differ visibly, just like other animals. For example, females are 25% larger than males with lighter pigmentation and more abdominal segments.The team of researchers, including Delphine Fagegaltier, PhD, lead author on the study, and CSHL Professor and Howard Hughes Medical Institute Investigator Greg Hannon, identified distinct miRNA populations in male and female flies. "We found that the differences in miRNAs are important in shaping the structures that distinguish the two sexes," says Fagegaltier. "In fact, miRNAs regulate the very proteins that act as sex determinants during development."The team found that miRNAs are essential for sex determination even after an animal has grown to adulthood. "They send signals that allow germ cells, i.e., eggs and sperm, to develop, ensuring fertility," Fagegaltier explains. "Removing one miRNA from mature, adult flies causes infertility." More than that, these flies begin to produce both male and female sex-determinants. "In a sense, once they have lost this miRNA, the flies become male and female at the same time," according to Fagegaltier. "It is amazing that the very smallest genes can have such a big effect on sexual identity."Some miRNAs examined in the study, such as let-7, have been preserved by evolution because of their utility; humans and many other animals carry versions of them. "This is probably just the tip of the iceberg," says Fagegaltier. "There are likely many more miRNAs regulating sexual identity at the cellular and tissue level, but we still have a lot to learn about these differences in humans, and how they could contribute to developmental defects and disease."
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STAMP: Japanese universities develop new world's fastest camera

STAMP: Japanese universities develop new world's fastest camera | naif | Scoop.it
Researchers working at two universities in Japan have jointly developed what is being described as the world's fastest camera. A photo-device with a frame interval of 4.4 trillion frames per second. In their paper published in the journal Nature Photonics, the team describes how their camera works, its capabilities and the extensive work that went into its creation.High speed cameras allow researchers and everyday people alike the ability to see things that they wouldn't be able to otherwise, from slowdown of sports play to mechanical processes. Prior to the announcement in Japan, the fastest cameras relied on what's known as a pump-probe process—where light is "pumped" at an object to be photographed, and then "probed" for absorption. The main drawback to such an approach is that it requires repetitive measurements to construct an image. The new camera is motion-based femtophotography, performing single-shot bursts for image acquisition, which means it has no need for repetitive measurements. It works via optical mapping of an object's spatial profile which varies over time. Its abilities make it 1000 times as fast as cameras it supersedes. In addition to the extremely high frame rate, the camera also has a high pixel resolution (450 × 450).Developed by a joint team of researchers from Keio University and the University of Tokyo, the camera is set to capture images of things and events that until now have not been impossible. With technology the team has named Sequentially Timed All-optical Mapping Photography, or STAMP for short, the camera is poised to be used to capture chemical reactions, lattice vibrational waves, plasma dynamics, even heat conduction, which the researchers note occurs at approximately a sixth the speed that light travels.The joint team has been working on development of the camera over the course of three years—plans call for continued development—the team would like to make the camera smaller (currently it's about a square meter) to allow for use in more applications. They also believe the camera could be used in a wide variety of fields, in both the public and private sectors. Some examples would be laser processes used for making big items like car parts, or in tiny applications such as the creation of semiconductors.A high-speed camera would allow researchers to actually see what is going on as the laser does its work. They also expect the camera to be useful in the medical field.
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Calcium-Rich Supernovae Could Be The Main Source Of Calcium In The Universe

Calcium-Rich Supernovae Could Be The Main Source Of Calcium In The Universe | naif | Scoop.it
Calcium-rich explosions involve ejected binary stars. Astronomers in the UK and Sweden looked at "calcium-rich supernovae", which are relatively weak and short-lived stellar explosions that appear to occur inexplicably far from the centres of galaxies. Its study suggests that such supernovae probably involve a white dwarf and neutron star that are ejected from a galaxy in an initial supernova and then merge sometime later to create the second explosion.Supernovae are exploding stars that can outshine entire galaxies before fading after a few weeks or months. They occur either when a star no longer produces enough energy to prevent gravitational collapse, or when a star suddenly acquires large amounts of matter from a disintegrating neighbor. These explosions are an important source of elements in the universe that are heavier than oxygen. In 2003 astronomers discovered a new type of supernova that produces vast amounts of calcium. Observations suggest that about half of the material produced by these explosions is calcium and this could explain the large quantities of the element seen in galaxies like the Milky Way – and here on Earth where calcium is essential for life.A puzzling aspect of the 12 known calcium-rich supernovae is that they appear to occur at large distances – tens of thousands of light-years – from any possible host galaxies. This is unlike other types of supernova, which tend to occur in regions that are populated by lots of other stars.Now, Joseph Lyman and colleagues at the University of Warwick, Lund Observatory and the University of Leicester have used the Very Large Telescope in Chile and the Hubble Space Telescope to study the regions surrounding these supernovae and have confirmed that they exist far from the nearest possible host galaxy."We present observations, going just about as faint as you can go, to show there is in fact nothing at the location of these transients – so the question becomes, how did they get there?" he ponders. Furthermore, the observations revealed no remnant stars in the vicinity of the supernovae, which means that they are unlikely to be formed by the explosion of a very massive star that has been ejected from a galaxy.What the team did notice, however, is that the light given off by the supernovae is similar to that seen during short-duration gamma-ray bursts (SGRBs). These also occur in isolated regions of space and are thought to involve the collision of two neutron stars or a neutron star with a black hole. While SGRBs are much dimmer than calcium-rich supernova – and do not appear to produce much calcium – this coincidence suggested to Lyman and colleagues that a neutron star might be at the heart of the mystery.
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How to synthesize structurally pure carbon nanotubes using molecular seeds

How to synthesize structurally pure carbon nanotubes using molecular seeds | naif | Scoop.it
By smoothing nanotube irregularities, a new process could lead to smaller, faster-switching next-generation electronic and electro-optical components. Researchers at Empa and the Max Planck Institute for Solid State Research have succeeded in “growing” single-wall carbon nanotubes (SWCNTs) with a single predefined structure, with identical electronic properties.The CNTs self-assembled out of tailor-made organic precursor molecules on a platinum surface, as reported by the researchers in the journal Nature.With a diameter of roughly one nanometer, SWCNTs should be considered as quantum structures; the slightest structural changes, such as differences in diameter or in the alignment of the atomic lattice, may result in dramatic changes in electronic properties.One SWCNT may be metallic, while another one with a slightly different structure is a semiconductor. So there is a great deal of interest in reliable methods of making SWCNTs as structurally uniform as possible. Such CNTs could help create next-generation electronic and electro-optical components that are smaller than ever before, allowing for faster switching times.Here’s how the researchers did it: - - Transform the flat (2D) starting molecule into a three-dimensional object, the “germling.” This takes place on a hot platinum surface using a catalytic reaction in which hydrogen atoms are split off and new carbon-carbon bonds are formed at very specific locations. The “germ” — a small, dome-like entity with an open edge that sits on the platinum surface — is “folded” out of the flat molecule. This “end cap” forms the “lid” of the growing SWCNT. - Attach more carbon atoms, which originate from the catalytic decomposition of ethylene (C2H4) on the platinum surface. They position themselves on the open edge between the platinum surface and the end cap, and raise the cap higher and higher, causing the nanotube to grow slowly upwards.Only the germ defines the nanotube’s atomic structure, as the researchers were able to demonstrate through the analysis of the vibration modes of the SWCNTs and scanning tunnel microscope (STM) measurements. Further investigations using the new scanning helium ion microscope (SHIM) at Empa show that the resulting SWCNTs reach lengths greater than 300 nanometers.The SWCNTs synthesized in this study are mirror-image symmetrical entities. However, depending on the manner in which the honeycombed atomic lattice is derived from the starting molecule (“straight” or “oblique” in relation to the CNT axis), it would also possible be possible to produce helically wound nanotubes, i.e., nanotubes twisting to the right or left, which are not mirror-image symmetrical.This structure also determines the electronic, thermoelectric, and optical properties of the material. So in principle, the researchers could produce materials with different properties in a targeted manner by selecting the starting molecule.The project was supported by the Swiss National Science Foundation (FNSNF).
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Fossils could be discovered on the moon: Signs of ancient life may be littered across the moon

Fossils could be discovered on the moon: Signs of ancient life may be littered across the moon | naif | Scoop.it
“Physicists have tested what would happen if a piece of rock containing microscopic fossils from Earth was launched into space and hit the surface of the moon. The team turned fossil-filled rock into powder which was mixed with water and frozen to replicate a meteoroid.”Kent physicists have tested what would happen if a piece of rock containing microscopic fossils from Earth was launched into space and hit the surface of the moon.In order to do this, Professor Mark Burchell and researchers from the University's Centre for Astrophysics simulated the condition that fossilised diatoms -- microscopic algae with detailed shells -- might have faced if travelling from earth to the moon.The team turned fossil-filled rock into powder which was mixed with water and frozen to replicate a meteoroid. The replica meteoroid was then fired into a bag of water using a large gas-powered gun to allow it experience the impact of being launched into orbit, whilst the rapid deceleration and high pressure as it hit the water simulated how it might have smashed into the moon at high speed.This suggests that if earth meteorites are ever found on the moon -- in the same way that we find lunar meteorites on earth -- then they may contain fossils from Earth's past.Reference: - - M. J. Burchell, K. H. McDermott, M. C. Price, L. J. Yolland. Survival of fossils under extreme shocks induced by hypervelocity impacts. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 2014; 372 (2023): 20130190 DOI: 10.1098/rsta.2013.0190
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Implanted Neurons made from Skin Cells become Part of the Brain

Implanted Neurons made from Skin Cells become Part of the Brain | naif | Scoop.it

Scientists at the Luxembourg Centre for Systems Biomedicine (LCSB) of the University of Luxembourg have grafted neurons reprogrammed from skin cells into the brains of mice for the first time with long-term stability. Six months after implantation, the neurons had become fully functionally integrated into the brain. This successful, because lastingly stable, implantation of neurons raises hope for future therapies that will replace sick neurons with healthy ones in the brains of Parkinson’s disease patients, for example. The Luxembourg researchers published their results in the current issue of ‘Stem Cell Reports’.

 

The LCSB research group around Prof. Dr. Jens Schwamborn and Kathrin Hemmer is working continuously to bring cell replacement therapy to maturity as a treatment for neurodegenerative diseases. Sick and dead neurons in the brain can be replaced with new cells. This could one day cure disorders such as Parkinson’s disease. The path towards successful therapy in humans, however, is long. “Successes in human therapy are still a long way off, but I am sure successful cell replacement therapies will exist in future. Our research results have taken us a step further in this direction,” declares stem cell researcher Prof. Schwamborn, who heads a group of 15 scientists at LCSB.

 

In their latest tests, the research group and colleagues from the Max Planck Institute and the University Hospital Münster and the University of Bielefeld succeeded in creating stable nerve tissue in the brain from neurons that had been reprogrammed from skin cells. The stem cell researchers’ technique of producing neurons, or more specifically induced neuronal stem cells (iNSC), in a petri dish from the host’s own skin cells considerably improves the compatibility of the implanted cells. The treated mice showed no adverse side effects even six months after implantation into the hippocampus and cortex regions of the brain. In fact it was quite the opposite – the implanted neurons were fully integrated into the complex network of the brain. The neurons exhibited normal activity and were connected to the original brain cells via newly formed synapses, the contact points between nerve cells.

 

Reference:

Hemmer K., Zhang M., van Wüllen, T., Sakalem M., Tapia N., Baumuratov A., Kaltschmidt C., KaltschmidtB, Schöler H. R., Zhang W., Schwamborn J. C. (2014) Induced neural stem cells achieve long-term survival and functional integration in the adult mouse brain. Stem Cell Reports, accepted, DOI: http://dx.doi.org/10.1016/j.stemcr.2014.06.017


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Scientists develop a 'nanovesicle' that delivers complementary molecules inside cells

Scientists develop a 'nanovesicle' that delivers complementary molecules inside cells | naif | Scoop.it
Researchers at the University of Miami and the University of Ulster have created self-assembling nanoparticles that can transport drugs and other molecules into target living cells.The new nanocarriers are just 15 nanometers in diameter, based on building blocks called amphiphilic polymers: they have both hydrophilic (water-loving, polar) and lipophilic (fat-loving) properties). That allows the nanocarriers to hold the guest molecules within their water-insoluble interior and use their water-soluble exterior to travel through an aqueous environment. And that makes the nanocarriers ideal for transferring molecules that would otherwise be insoluble in water.They also emit a fluorescent signal that can be observed with a microscope, allowing for tracking and photographing the nanoparticles in the body.“The size of these nanoparticles, their dynamic character and the fact that the reactions take place under normal biological conditions (at ambient temperature and neutral environment) makes these nanoparticles an ideal vehicle for the controlled activation of therapeutics, directly inside the cells,” says lead investigator Francisco Raymo, professor of chemistry in the University of Miami College of Arts and Sciences and UM laboratory for molecular photonics.The next phase of this investigation involves demonstrating that this method can be used to achieve chemical reactions inside cells, instead of energy transfers.
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