Researchers at Brigham and Women's Hospital (BWH) have successfully tested a controllable endoscopic capsule, inspired by science fiction, that has the ability to "swim" through the body and could provide clinicians with unprecedented control when photographing the inside of the human body.
The capsule is designed to be swallowed like a pill and can be equipped with a camera. Once inside the patient's digestive track, a doctor can "steer" the capsule through the body using an MRI machine, photograph specific areas of interest, and view those pictures wirelessly.
With current endoscopic capsule technology, the capsule tumbles randomly through the digestive track and clinicians have no control over what areas of the body are being photographed. The ability to steer a capsule, aim a camera, and take pictures of specific areas of concern is a major leap forward with the potential for broad medical implications.
"Our goal is to develop this capsule so that it could be used to deliver images in real time, and allow clinicians to make a diagnosis during a single procedure with little discomfort or risk to the patient," said Noby Hata, a researcher in the Department of Radiology at BWH and leader of the development team for the endoscopic capsule. "Ideally, in the future we would be able to utilize this technology deliver drugs or other treatments, such as laser surgery, directly to tumors or injuries within the digestive track."
BWH researchers Hata and his colleague, Peter Jakab, have successfully tested a prototype of their capsule in an MRI machine and proved that the capsule can be manipulated to "swim" through a tank of water. The next step in their research is to successfully test the capsule inside a human body. There is no reason to believe the capsule would move differently in a human than it does in a tank of water.
Announced on January in Yangon, Myanmar, a joint team from Fauna & Flora International (FFI), Biodiversity And Nature Conservation Association (BANCA) and People Resources and Conservation Foundation (PRCF), caught pictures of the monkey on camera traps placed in the high, forested mountains of Kachin state, bordering China.
World's first images of Mynamar snub-nosed monkey caught on film. Credit: FFI/BANCA/PRCF
“The Myanmar snub-nosed monkey was described scientifically in 2010 from a dead specimen collected from a local hunter,” said Frank Momberg of FFI, who organised the initial expeditions that led to the monkey’s discovery. “As yet, no scientist has seen a live individual,” he added.
“These images are the first record of the animal in its natural habitat,” said Ngwe Lwin, the Burmese national who first recognized the monkey as a possible new species. “It is great to finally have photographs because they show us something about how and where it actually lives,” he added.
Myanmar snub-nosed monkey with infants. Credit: FFI/BANCA/PRCF
Heavy snows in January and constant rain in April made expeditions to set the camera traps difficult. “We were dealing with very tough conditions in a remote and rugged area that contained perhaps fewer than 200 monkeys,” said Jeremy Holden, who led the camera trapping team. “We didn’t know exactly where they lived, and I didn’t hold out much hope of short term success with this work.” But in May a small group of snub-nosed monkeys walked past one of the cameras and into history. “We were very surprised to get these pictures,” said Saw Soe Aung, a field biologist who set the cameras. “It was exciting to see that some of the females were carrying babies – a new generation of our rarest primate.”
As with most of Asia’s rare mammals, the snub-nosed monkey is threatened by habitat loss and hunting. The team is now working together with the Ministry of Environmental Conservation and Forest (MOECAF), local authorities and communities to help safeguard the future of the species. In February this year, FFI and MOECAF will hold an international workshop in Yangon aiming to create a conservation action plan for the Myanmar snub-nosed monkey.
In addition to the world’s first images of the snub-nosed monkey, the camera trapping also caught photos of other globally threatened species including red panda, takin, marbled cat, Malayan sun bear and rare pheasants such as Temminick’s tragopan, documenting the importance of this area for biodiversity conservation.
However, there is an increased risk of individuals who have experienced previous traumatic brain injury going on to commit violent crime according to a large Swedish study led by Seena Fazel from the University of Oxford, UK, and colleagues at the Karolinska Institutet, Sweden, and Swedish Prison and Probation Service, and published in this week's PLoS Medicine.
The authors say: "The implications of these findings will vary for clinical services, the criminal justice system, and patient charities."
In their study, the authors identified all people with epilepsy and traumatic brain injury recorded in Sweden between 1973 and 2009 and matched each case with ten people without these brain conditions from the general population. The investigators linked these records to subsequent data on all convictions for violent crime using the personal identification numbers that identify Swedish residents in national registries.
Using these methods, the authors found that 4.2% of people with epilepsy had at least one conviction for violence after their diagnosis compared to 2.5% of the general population. However, after controlling for the family situation (in which individuals with epilepsy were compared with their unaffected siblings), the association between being diagnosed with epilepsy and being convicted for violent crime disappeared. In contrast, the authors found that after controlling for substance abuse or comparing individuals with brain injury to their unaffected siblings, there remained an association between experiencing a traumatic brain injury and committing a violent crime.
The authors say: "With over 22,000 individuals each for the epilepsy and traumatic brain injury groups, the sample was, to our knowledge, more than 50 times larger than those used in previous related studies on epilepsy, and more than seven times larger than previous studies on brain injury."
They continue: "In conclusion, by using Swedish population-based registers over 35 years, we reported risks for violent crime in individuals with epilepsy and traumatic brain injury that contrasted with each other, and appeared to differ within each diagnosis by subtype, severity, and age at diagnosis."
The authors suggest that the lack of a causal association with epilepsy and violent crime may be valuable for patient charities and other stakeholders in tackling one of the causes of stigma associated with this condition. In contrast, improved screening and management of some patients and prisoners with traumatic brain injury may reduce offending rates,
The study relied on conviction data and the authors explain their rationale: "Although we relied on conviction data, other work has shown that the degree of underestimation of violence is similar in psychiatric patients and controls compared with self-report measures, and hence the risk estimates were unlikely to be affected…We have no reason to think that this would be different for these two neurological conditions. Overall rates of violent crime and their resolution are mostly similar across western Europe, suggesting some generalisability of our findings."
In an accompanying Perspective, psychiatrist Jan Volavka, professor emeritus from the New York University School of Medicine (uninvolved in the research) says: "Comparing the conviction rates before and after the diagnosis would provide another perspective on the effect of the illness on violent crime." However, he says: "Among the major strengths of the study are the very large sample size, comprising the entire population of Sweden, and the follow-up of 35 years. The findings are of major public health importance and provide inspiration for further research".
A new method described in BioMed Central's open access journal BMC Medicine uses stem cells from cord blood to re-educate a diabetic's own T cells and consequently restart pancreatic function reducing the need for insulin.
Stem Cell Educator therapy slowly passes lymphocytes separated from a patient's blood over immobilized cord blood stem cells (CBSC) from healthy donors. After two to three hours in the device the re-educated lymphocytes are returned to the patient. The progress of the patients was checked at 4, 12, 24 and 40 weeks after therapy.
C-peptide is a protein fragment made as a by-product of insulin manufacture and can be used to determine how well beta cells are working. By 12 weeks after treatment all the patients who received the therapy had improved levels of C –peptide. This continued to improve at 24 weeks and was maintained to the end of the study. This meant that the daily dose of insulin required to maintain their blood glucose levels could be reduced. In accordance with these results the glycated hemoglobin (HbA1C) indicator of long term glucose control also dropped for people receiving the treatment, but not the control group.
Dr Yong Zhao, from University of Illinois at Chicago, who led the multi-centre research, explained, "We also saw an improved autoimmune control in these patients. Stem Cell Educator therapy increased the percentage of regulatory T lymphocytes in the blood of people in the treatment group. Other markers of immune function, such as TGF-beta1 also improved. Our results suggest that it is this improvement in autoimmune control, mediated by the autoimmune regulator AIRE in the CBSC, which allows the pancreatic islet beta cells to recover."
No one has yet made a superlens, also known as a perfect lens, though people are trying. Optical lenses are limited by the nature of light, the so-called diffraction limit, so even the best won't usually let us see objects smaller than 200 nanometers across, about the size of the smallest bacterium. Scanning electron microscopes can capture objects that are much smaller, about a nanometer wide, but they are expensive, heavy, and, at the size of a large desk, not very portable.
To build a superlens, you need metamaterials: artificial materials with properties not seen in nature. Scientists are beginning to fabricate metamaterials in their quest to make real seemingly magical phenomena like invisibility cloaks, quantum levitation—and superlenses.
Now Guney, an assistant professor of electrical and computer engineering at Michigan Technological University, has taken a major step toward creating superlens that could use visible light to see objects as small as 100 nanometers across.
This is an illustration of Durdu Guney's theoretical negative-index metamaterial, which would be the heart of a perfect lens. The colors show magnetic fields generated by plasmons. The black arrows show the direction of electrical current in metallic layers, and the numbers indicate current loops that contribute to negative refraction. Credit: Durdu Guney
The secret lies in plasmons, charge oscillations near the surface of thin metal films that combine with special nanostructures. When excited by an electromagnetic field, they gather light waves from an object and refract it in a way not seen in nature called negative refraction. This lets the lens overcomes the diffraction limit. And, in the case of Guney's model, it could allow us to see objects smaller than 1/1,000th the width of a human hair.
Other researchers have also been able to sidestep the diffraction limit, but not throughout the entire spectrum of visible light. Guney's model showed how metamaterials might be "stretched" to refract light waves from the infrared all the way past visible light and into the ultraviolet spectrum.
Making these superlenses would be relatively inexpensive, which is why they might find their way into cell phones. But there would be other uses as well, says Guney.
"It could also be applied to lithography," the microfabrication process used in electronics manufacturing. "The lens determines the feature size you can make, and by replacing an old lens with this superlens, you could make smaller features at a lower cost. You could make devices as small as you like."
Computer chips are made using UV lasers, which are expensive and difficult to build. "With this superlens, you could use a red laser, like the pointers everyone uses, and have simple, cheap machines, just by changing the lens."
What excites Guney the most, however, is that a cheap, accessible superlens could open our collective eyes to worlds previously known only to a very few.
"The public's access to high-powered microscopes is negligible," he says. "With superlenses, everybody could be a scientist. People could put their cells on Facebook. It might just inspire society's scientific soul."
Guney and graduate student Muhammad Aslam published an article on their work, "Surface Plasmon Diven Scalable Low-Loss Negative-Index Metamaterial in the visible spectrum," in Physical Review B, volume 84, issue 19.
Creative sound-making is as fluid and changing as it implies, incorporating everything from troupes that bang on every hard surface imaginable to creators of electronic music, to musicians who craft their notes to reflect real conversation, to the new phenomenon, the Mogees.
The Mogees is a project that stems from the department of computing at Goldsmiths, University of London, where researcher Bruno Zamborlin collaborates with a team at IRCAM in Paris to experiment with new methods for “gestural interaction” in coming up with novel ways of making sounds. The project has released a video that, besides delighting every four year old on the planet, opens the minds of researchers. The video shows the use of a contact microphone and audio processing software to construct a gesture-recognizing touch interface from assorted surfaces—a tree trunk, a balloon, a glass panel at a bus stage, and an inflated balloon. Also, different gestures control different sounds.
Wooden panels sound like a bicycle bell; playing on a balloon makes sounds like a crystal hanging ornament in the wind. Other surfaces reveal sounds, by slapping or brushing, hitting, or finger tapping, that include tribal string pianos in the heat of a musical narrative.
The Mogees project turns any surface into a gestural musical interface, using the button-like silver microphone and audio processing software. But just how does it work? ExtremeTech carries the more lucid of attempted explanations: The contact microphone has multiple microphones, creating a stereo image of a sound that’s made. A PC cable connection picks up the finger vibrations for analysis and converts them into gestures. A visual programming language (MaxMSP) turns the gestures into sounds.
“Mogees is an interactive gestural-based surface for realtime audio mosaicing,” is the somewhat intimidating definition appearing on the Department of Computing site at Goldsmiths. A helpful explanation, however, also contributes toward understanding what is going on.
“When the performer touches the surface, Mogees analyses the incoming audio signal and continuously looks for its closest segment within the sound database. These segments are played one after the other over time: this technique is called concatenative synthesis.”
A surface, for example, can be played with any tool such as hands and Mogees will always try to find a correspondent sound to it. It can also be applied to other sound sources such as voice or acoustic/electric instruments.
Zamborlin began the project because he liked the idea of being able to touch a real surface when creating electronic music. “Touching real surfaces allows users to experience haptic feedback on what they do and enhancing their relationship with the device."
Researcher and developer Norbert Schnell is named as part of the Mogees effort, and the project also makes reference to its use of the “MuBu environment for MaxMSP.”
Max is a visual programming language for music and multimedia; electronic musicians use it for unique sound-making tools. The program is highly modular with most routines in the form of shared libraries. MuBu is a sound description buffer for real-time interactive audio processing.
Viruses can enter the body via a number of pathways and while scientists have known how to block the main one used by viruses such as HIV, Hepatitis C, Dengue Fever and West Nile virus for some time, these viruses are able to bypass this main pathway to replicate and cause disease via a second pathway by hijacking an enzyme known as endomannosidase. Now an international team of researchers has determined the three-dimensional structure of the enzyme endomannosidase, opening the door for new treatments to a variety of deadly viruses through the development of inhibitors that block this bypass route.
The international team, led by Associate Professor Spencer Williams from the University of Melbourne's Bio21 Institute and Professor Gideon Davies from the University of York in the UK, studied bacterial endomannosidase as a model for the same human enzyme.
"If we understand how the viruses use our enzymes, we can develop inhibitors that block the pathway they require, opening the door to drug developments," said Professor Davies, of the Department of Chemistry at York. "It was already known how to block the main pathway for these viruses but until now, this endomannosidase bypass pathway has proved a considerable challenge to study."
Using synchrotron technology, the team successfully determined the three-dimensional structure of the enzyme, thus revealing details on how viruses essentially play biological "piggy-back" to turn our own cellular machinery to their own nefarious purposes.
Associate Professor Williams also told Australia's ABC News that, because the findings relate to our own pathways, which aren't prone to mutation, rather than on viral pathways, which are, the risk of creating drug-resistant viral strains is also reduced. The team also hopes that their work will have applications beyond viruses and will lead to similar treatments for other diseases including cancer.
While the research will provide hope for the development of drugs to combat these deadly viruses that infect more than 180 million people worldwide each year, Associate Professor Williams expects it will take at least 10 years to develop such virus-fighting drugs based on the research.
Scientists are now trying to use plasmonic nanoparticles in cancer therapy whereby light energy is converted into heat in order to kill cancer cells. The advantage of such treatment is that it does not cause side effects that are common to chemotherapy. Mingyong Han at the A*STAR Institute of Materials Research and Engineering and co-workers have now developed gold plasmonic nanocrosses that are particularly suited to eliminating cancer cells in cancer therapy. The team demonstrated the usefulness of these nanocrosses by using them to kill human lung cancer cells.
In general, metallic nanostructures have a particular frequency at which light excites electrons close to their surface. The collective movement of electrons, or resonance, in the metal is what converts the light energy into heat. The wavelength at which the resonance occurs is strongly dependent on the size and shape of the nanostructures.
For biomedical applications, the nanostructures should be effective no matter which direction they are illuminated from. Furthermore, the nanostructures should be efficient in absorbing near- to mid-infrared wavelengths because tissue is transparent to the light of these wavelengths.
Based on these requirements, the researchers decided to make gold nanocrosses (see image). In normal synthesis, however, gold would usually grow into the shape of the nanorods. To fabricate nanocrosses, the researchers added copper ions to the growth solution. The incorporation of small amounts of copper caused a twinning of the gold’s crystal structure, which in turn led to the growth of side arms from the crystal facets. “The unique cross-shaped gold structure enables multi-directional excitation to achieve a strong plasmonic resonance in the near- and mid-infrared region. This greatly lowers the laser power required for photothermal cancer therapy compared to nanorods,” says Han.
The researchers tested the performance of their gold nanocrosses by modifying their surfaces and binding them to human lung cancer cells. When irradiated with near-infrared laser light of relatively modest powers of 4.2 W/cm2 for 30 seconds, all cancer cells were killed. The researchers are now planning to test the effectiveness of the gold nanocrosses on animal models in future experiments.
Other applications of the gold nanocrosses are also possible, including photothermal imaging, in which small amounts of light are converted into local heat, or the sterilization of surfaces. “In our current research, we are studying gold nanocrosses for the photothermal destruction of superbugs on biofilms,” says Han.
Now Tel Aviv University researchers say that glia cells are central to the brain's plasticity — how the brain adapts, learns, and stores information.
According to Ph.D. student Maurizio De Pittà of TAU's Schools of Physics and Astronomy and Electrical Engineering, glia cells do much more than hold the brain together. A mechanism within the glia cells also sorts information for learning purposes, De Pittà says. "Glia cells are like the brain's supervisors. By regulating the synapses, they control the transfer of information between neurons, affecting how the brain processes information and learns."
This is a network of neurons (in red) and glia cells (in green) grown in a petri dish. Blue dots are the cells' nuclei. Credit: Pablo Blinder/American Friends of Tel Aviv University (AFTAU)
De Pittà's research, led by his TAU supervisor Prof. Eshel Ben-Jacob, along with Vladislav Volman of The Salk Institute and the University of California at San Diego and Hugues Berry of the Université de Lyon in France, has developed the first computer model that incorporates the influence of glia cells on synaptic information transfer. Detailed in the journal PLoS Computational Biology, the model can also be implemented in technologies based on brain networks such as microchips and computer software, Prof. Ben-Jacob says, and aid in research on brain disorders such as Alzheimer's disease and epilepsy.
Regulating the brain's "social network"
The brain is constituted of two main types of cells: neurons and glia. Neurons fire off signals that dictate how we think and behave, using synapses to pass along the message from one neuron to another, explains De Pittà. Scientists theorize that memory and learning are dictated by synaptic activity because they are "plastic," with the ability to adapt to different stimuli.
But Ben-Jacob and colleagues suspected that glia cells were even more central to how the brain works. Glia cells are abundant in the brain's hippocampus and the cortex, the two parts of the brain that have the most control over the brain's ability to process information, learn and memorize. In fact, for every neuron cell, there are two to five glia cells. Taking into account previous experimental data, the researchers were able to build a model that could resolve the puzzle.
The brain is like a social network, says Prof. Ben-Jacob. Messages may originate with the neurons, which use the synapses as their delivery system, but the glia serve as an overall moderator, regulating which messages are sent on and when. These cells can either prompt the transfer of information, or slow activity if the synapses are becoming overactive. This makes the glia cells the guardians of our learning and memory processes, he notes, orchestrating the transmission of information for optimal brain function.
New brain-inspired technologies and therapies
The team's findings could have important implications for a number of brain disorders. Almost all neurodegenerative diseases are glia-related pathologies, Prof. Ben-Jacob notes. In epileptic seizures, for example, the neurons' activity at one brain location propagates and overtakes the normal activity at other locations. This can happen when the glia cells fail to properly regulate synaptic transmission. Alternatively, when brain activity is low, glia cells boost transmissions of information, keeping the connections between neurons "alive."
The model provides a "new view" of how the brain functions. While the study was in press, two experimental works appeared that supported the model's predictions. "A growing number of scientists are starting to recognize the fact that you need the glia to perform tasks that neurons alone can't accomplish in an efficient way," says De Pittà. The model will provide a new tool to begin revising the theories of computational neuroscience and lead to more realistic brain-inspired algorithms and microchips, which are designed to mimic neuronal networks.
However, producing these networks, which are only one atom thick, in high quality and with the greatest possible stability currently still poses a great challenge. Scientists from the Excellence Cluster Nanosystems Initiative Munich have now successfully created just such networks made of boron acid molecules. The current issue of the scientific journal ACS Nano reports on their results.
Even the costliest oriental carpets have small mistakes. It is said that pious carpet-weavers deliberately include tiny mistakes in their fine carpets, because only God has the right to be immaculate. Molecular carpets, as the nanotechnology industry would like to have them are as yet in no danger of offending the gods. A team of physicists headed by Dr. Markus Lackinger from the Technische Universität München (TUM) und Professor Thomas Bein from the Ludwig-Maximilians-Universität München (LMU) has now developed a process by which they can build up high-quality polymer networks using boron acid components.
The "carpets" that the physicists are working on in their laboratory in the Deutsches Museum München consist of ordered two-dimensional structures created by self-organized boron acid molecules on a graphite surface. By eliminating water, the molecules bond together in a one-atom thick network held together solely by chemical bonds – a fact that makes this network very stable. The regular honey-comb-like arrangement of the molecules results in a nano-structured surface whose pores can be used, for instance, as stable forms for the production of metal nano-particles.
The molecular carpets also come in nearly perfect models; however, these are not very stable, unfortunately. In these models the bonds between the molecules are very weak – for instance hydrogen bridge bonds or van der Waals forces. The advantage of this variant is that faults in the regular structure are repaired during the self-organization process – bad bonds are dissolved so that proper bonds can form.
However, many applications call for molecular networks that are mechanically, thermally and/or chemically stable. Linking the molecules by means of strong chemical bonds can create such durable molecule carpets. The down side is that the unavoidable weaving mistakes can no longer be corrected due to the great bonding strength.
Markus Lackinger and his colleagues have now found a way to create a molecular carpet with stable covalent bonds without significant weaving mistakes. The method is based on a bonding reaction that creates a molecular carpet out of individual boron acid molecules. It is a condensation reaction in which water molecules are released. If bonding takes place at temperatures of a little over 100°C with only a small amount of water present, mistakes can be corrected during weaving. The result is the sought after magic carpet: molecules in a stable and well-ordered one-layer structure.
Markus Lackinger's laboratory is located in the Deutsches Museum München. There he is doing research at the Chair of Prof. Wolfgang Heckl (TUM School of Education, TU München). Prof. Bein holds a Chair at the Department of Chemistry at the LMU. The research was conducted in collaboration with Prof. Paul Knochel's work group (LMU) and Physical Electronics GmbH, with funding by the Excellence Cluster Nanosystems Initiative Munich (NIM) and the Bavarian Research Foundation (BFS).
More information: Synthesis of well-ordered COF monolayers: Surface growth of nanocrystalline precursors versus direct on-surface polycondensation, Jürgen F. Dienstmaier, Alexander M. Gigler, Andreas J. Goetz, Paul Knochel, Thomas Bein, Andrey Lyapin, Stefan Reichlmaier, Wolfgang M. Heckl, and Markus Lackinger, ACS Nano Vol. 5, 12, 9737-9745
(p)Link
Commenti
Storico
Stampa
Feed RSS 0.91
Feed Atom 0.3
