#Carbon nanotube sensor detects spoiled meat MIT chemists have devised an inexpensive, portable sensor that can detect gases emitted by rotting meat,
allowing consumers to determine whether the meat in their grocery store or refrigerator is safe to eat.
The sensor, which consists of chemically modified carbon nanotubes, could be deployed in"smart packaging"that would offer much more accurate safety information than the expiration date on the package,
says Timothy Swager, the John D. Macarthur Professor of Chemistry at MIT. This MIT device, based on modified carbon nanotubes, can detect amines produced by decaying meat.
It could also cut down on food waste he adds.""People are constantly throwing things out that probably aren't bad,
"says Swager, who is the senior author of a paper describing the new sensor this week in the journal Angewandte Chemie("Single-Walled carbon nanotube/Metalloporphyrin Composites for the Chemiresistive Detection of Amines and Meat Spoilage").
"The paper's lead author is graduate student Sophie Liu. Other authors are former lab technician Alexander Petty and postdoc Graham Sazama.
The sensor is similar to other carbon nanotube devices that Swager's lab has developed in recent years,
including one that detects the ripeness of fruit. All of these devices work on the same principle:
Carbon nanotubes can be modified chemically so that their ability to carry an electric current changes in the presence of a particular gas.
In this case, the researchers modified the carbon nanotubes with metal-containing compounds called metalloporphyrins, which contain a central metal atom bound to several nitrogen-containing rings.
Hemoglobin, which carries oxygen in the blood, is a metalloporphyrin with iron as the central atom.
For this sensor, the researchers used a metalloporphyrin with cobalt at its center. Metalloporphyrins are very good at binding to nitrogen-containing compounds called amines.
Of particular interest to the researchers were the so-called biogenic amines such as putrescine and cadaverine, which are produced by decaying meat.
When the cobalt-containing porphyrin binds to any of these amines, it increases the electrical resistance of the carbon nanotube,
which can be measured easily.""We use these porphyrins to fabricate a very simple device where we apply a potential across the device
and then monitor the current. When the device encounters amines, which are markers of decaying meat,
the current of the device will become lower, "Liu says. In this study, the researchers tested the sensor on four types of meat:
pork, chicken, cod, and salmon. They found that when refrigerated, all four types stayed fresh over four days.
There are other sensors that can detect the signs of decaying meat, but they are usually large and expensive instruments that require expertise to operate."
easiest-to-manufacture sensors, "Swager says. The new device also requires very little power and could be incorporated into a wireless platform Swager's lab recently developed that allows a regular smartphone to read output from carbon nanotube sensors such as this one.
The researchers have filed for a patent on the technology and hope to license it for commercial development t
#Travel Inside 3d Cells In full Color on Your Laptop Nanolive SA announces the release of an off-line version of STEVE. Starting from today, scientists,
Medical Doctors and students all around the world will be enabled to travel inside 3d cells in full color by simply downloading STEVE on their laptop declares Dr. Yann Cotte, CEO and cofounder of Nanolive SA.
which is developing a revolutionary microscope (and a revolutionary software) able to image and digitally stain living cells in 3d without any sample preparation and in real-time.
which has received already more than 45 pre-orders (with partial up-front payments), is planning the market entry for this summer.
In contrast, Nanolives technology detects the physical refractive index of the different cell parts with resolution far beyond the diffraction limit (see Nobel prize 2014 for chemistry.
As the Nanolives microscope, the 3d Cell Explorer, can be handled with without special training, the company has developed unique software called STEVE. To mark
and label certain parts of the measured cells in 3d, the software allows the user to virtual brush
and digitally paint the part of a cell based on their physical properties (called refractive index). STEVE will automatically define all regions with same refractive index characteristics (different organelles have different optical properties)
and digitally stain them with the same color. This process is quantitative and can be applied for a limitless amount of colors.
Changes to digital stains are shown in real time in both 2d and 3d views. Stains panels can be modified constantly by the user,
saved and reused for other cells of the same line. click on image to enlarge) For additional support,
Just like a MRI for human bodies, Nanolives 3d Cell Explorer makes a complete tomography of the living cell and as distinct from Hell,
As a result, the user has the possibility to measure authentic cells physiological activity, and, with the help of STEVE, she/he can discover its interior components, such as nucleus and organelles, on any screen and in a limitless amount of colors.
It takes just seconds to get up and running with the 3d Cell Explorer: the user only needs to switch on the microscope,
position the sample and initiate the analysis. The microscope instantly self-adjusts and, instantly, a full 3d image of the cell is displayed on the computer screen.
Nanolives technology was published in Nature Photonics in 2013("Marker-free phase nanoscopy), "and has the potential to enable completely new fields of research,
Website: http://nanolive. ch h
#Quick, easy and early diagnosis with rare earth ions Lack of oxygen in cells is an indicator of diseases as serious as cerebral haemorrhages, stroke and cancer.
Regrettably measuring real-time oxygen concentration in living tissue is difficult with current technologies. Now a chemist from the University of Copenhagen in collaboration with chemists from Oxford university has invented a compound
which measures oxygen in cells and other biological material with high precision. The compound is based on rare earths emitting coloured light that vary in colour with the amount of oxygen present in the sample.
Because emissions are in the visible range of the spectrum it will be possible to measure oxygen using the optical microscopes already present in most hospitals.
Thomas Just Sørensen is Associate professor at the Department of chemistry, Nanoscience Centre, University of Copenhagen. Together with his English team and his Copenhagen partner, Tom Vosch, he has published the articles:"
"Bimetallic lanthanide complexes that display a ratiometric response to oxygen concentration"in the periodical Chemical sciences and"Spectrally resolved confocal microscopy using lanthanide centred near-IR emission"in Chemical Communications.
Both are Royal Society of Chemistry-publications. According to Sørensen, the two articles constitute proof-of-concept that he is capable of measuring oxygen concentrations in an easy,
quick and cheap manner but he is certain that development towards a useful technology will be speedy."
and we are getting pretty good at synthesizing the rare earth containing molecules. Before the year is out,
I am almost certain that we will see the first medical doctors using our method for measuring oxygen in cells,
The novel oxygen sensitive molecule is built with two rare earths, so called lanthanides. One lanthanide, europium, emits a constant red signal.
The other, terbium, emits a green signal that increases with diminishing oxygen concentrations. Most physicians should be able to read the oxygen concentration with the naked eye,
explains Thomas Just Sørensen.""You simply deduct the amount of red light from the amount of green to get a precise reading of the oxygen level.
Unfortunately I cannot see how well my system works, because I am red-green colour-blind.
which are suited poorly for biological samples, useless in a microscope and quite incapable of showing where the oxygen is located in a cell.
Because Sørensen's molecules work by way of a simple colour shift they give a very exact indication of quantity as well as location of oxygen in a tissue sample or inside a cell.
which is highly compatible with biological studies, because it penetrates deeply into tissue, explains Sørensen."
"The detector and light source was the same as on light microscopes found at any hospital, but my colleague Tom Vosch has optimized the microscope to the point where everything is almost beyond the possible.
but it works",says Thomas Just Sørensen. Source: University of Base s
#Bio-inspired eye stabilizes robot's flight without need for an accelerometer Biorobotics researchers at the Institut des Sciences du Mouvement-Etienne-Jules Marey (CNRS/Aix-Marseille
Universit) have developed the first aerial robot able to fly over uneven terrain that is stabilized visually without an accelerometer.
Called Beerotor, it adjusts its speed and avoids obstacles thanks to optic flow sensors inspired by insect vision.
It can fly along a tunnel with uneven, moving walls without measuring either speed or altitude.
The study was published on 26 february 2015 in the journal Bioinspiration & Biomimetics("Flying over uneven moving terrain based on optic-flow cues without any need for reference frames or accelerometers").
"The Beerotor robot, equipped with an eye inspired by that of insects. All aircraft, from drones to the Ariane launcher, are equipped currently with an inertial measurement unit,
including accelerometers. This allows these aircraft to stabilize their roll and pitch with respect to the horizon or rather with respect to its perpendicular:
the direction of the center of the Earth. An accelerometer measures all the accelerations of the aircraft including gravity,
which is directed always toward the center of the Earth. However, this essential tool has no equivalent in insects,
which fly quite happily without this information. Researchers Fabien Expert and Franck Ruffier therefore took inspiration from winged insects to create Beerotor,
a tethered flying robot1 able for the first time to adjust its speed and follow terrain with no accelerometer and without measuring speed or altitude.
With a weight of 80 grams and a length of 47 centimeters it can, all by itself, avoid vertical obstacles in a tunnel with moving walls.
To achieve this, the researchers mimicked the ability of insects to use the passing landscape as they fly.
the landscape passes by faster and faster, reaching a maximum at an angle of 90 degrees to the path of the vehicle.
(or pixels) distributed at the top and the bottom of its eye. This enables it to detect contrasts in the environment as well as their motion.
As in insects, the speed at which a feature in the scenery moves from one pixel to another provides the angular velocity of the flow.
When the flow increases this means that the robot's speed is also increasing or that the distance relative to obstacles is decreasing.
The first feedback loop makes it change its altitude so as to follow the floor or the roof..
in order to adapt it to the size of the tunnel through which it flies. The third loop stabilizes the eye in relation to the local slope,
Beerotor can thus avoid very steeply sloping obstacles (see video) with no accelerometer and without measuring speed or altitude.
biologically plausible hypothesis to explain how insects can fly without an accelerometer: winged insects may use cues from optic flow to remain stable,
Accelerometers, and therefore the inertial reference systems3 that contain them, are too heavy and bulky for very small robots.
Without necessarily replacing accelerometers optic flow sensors could be used as an ultra-light backup system in the event of failure on a space mission4.
Notes (1) The robot, which has 3 degrees of freedom (pitch, altitude, forward) flies around an axis to
to calculate the input, in this case the speed of each rotor. This is known as a negative feedback loop,
3) An inertial reference system is used an instrument in navigation that is able to process the measurements of a device's motion (acceleration and angular velocity) in order to estimate its orientation (angles of roll, pitch and heading.
Sub-optimal Lunar Landing GNC using Non-gimbaled Bio-inspired Optic Flow Sensors, G. Sabiron, T. Raharijaona, L. Burlion, E. Kervendal, E
#Nanoparticles could make big impact for patients in need of cornea transplant There are about 48,000 corneal transplants done each year in the U s,
. compared to approximately 16,000 kidney transplants, according to the National Kidney Foundation, and 2, 100 heart transplants, according to the U s. Department of health and human services'Organ Transplantation Network.
Out of the 48,000 corneal transplants done, 10 percent of them end up in rejection, largely due to poor medication compliance.
This costs the health care system and puts undue strain on clinicians, patients and their families. Johns Hopkins Medicine researchers may have discovered a way to prevent rejection by using biodegradable nanoparticles that release needed medication into the eye after surgery.
This discovery could solve the decades-old issue of medicine compliance and help patients achieve corneal transplant success. Medicine compliance is a major challenge in patient care,
says Walter Stark, M d.,chief of the Division of Cornea, Cataract and External Eye diseases at Johns Hopkins. About 60 to 80 percent of patients dont take medicine the way they are supposed to.
In an animal study being published in the March 10 issue of the Journal of Controlled Release("Corticosteroid-loaded biodegradable nanoparticles for prevention of corneal allograft rejection in rats),
"researchers looked into ways to alleviate the strain of adhering to a post-surgery treatment regimen that is sometimes hard to manage.
Rats that underwent a corneal graft surgery were divided randomly into four groups and were given various treatments.
One group was injected weekly for nine weeks with a safe, biodegradable nanoparticle loaded with corticosteroids for timed release of medicine.
The other three groups received weekly injections of saline, placebo nanoparticles and free dexamethasone sodium phosphate aqueous solution after surgery, respectively.
Treatments were given until the graft was deemed clinically as failed or until the nine-week test period concluded.
Researchers looked at corneal transparency, swelling and growth of new blood vessels to decide if a graft had failed.
For rats that received the nanoparticle loaded with corticosteroids, 65 percent of the treatment remained in the eye
and did not leak within one week of the surgery. The concentration of the treatment also remained stronger than in the other three treatment groups Additionally,
Two weeks after surgery, rats that received the placebo nanoparticle and saline injections had severe swelling, opaque corneas and unwanted growth of new blood vessels, all indicating graft failure.
After four weeks, rats that received free dexamethasone sodium phosphate aqueous solution all had graft failure as well.
The only group that showed successful corneal transplant was the group of rats that received the corticosteroid-loaded nanoparticle injections.
and a lot of testing and time goes into ensuring the safe use of a graft for cornea transplant,
. a research associate at the Center for Nanomedicine at the Wilmer Eye Institute at Johns Hopkins Medicine.
The steroid-loaded nanoparticle treatment group showed no signs of corneal transplant rejection. Thats 100 percent efficacy, a very promising finding, says Justin Hanes, Ph d.,director of the Center for Nanomedicine.
This type of treatment may also help prevent corneal transplant rejection in humans while making medicine adherence much easier on patients and their families The nanoparticle loaded with medication could eliminate the need for a patient to remember to take their medicine often multiple doses per hour after a surgery,
alleviating compliance risk. These types of drug delivery systems could be paired with other drugs and used in other conditions, such as glaucoma, macular degeneration and corneal ulcers, among others.
The research team intends to continue the collaboration between engineering and medicine to look further into better ways to treat eye diseases s
#Flexible sensors turn skin into a touch-sensitive interaction space for mobile devices (w/video) If a mobile phone rings during a meeting,
its owner often has to dig it out before it can be muted. A more discreet method would be to decline the incoming call by pressing on one of your fingers.
Computer scientists at Saarland University are studying the potential use of the human body as a touch sensitive surface for controlling mobile devices.
They have developed flexible silicone rubber stickers with pressure-sensitive sensors that fit snugly to the skin.
users can use their own body to control mobile devices. Because of the flexible material used, the sensors can be manufactured in a variety of shapes, sizes and personalized designs.
The research team will be presenting the Skinproject from March 16th to March 20th at the Cebit computer expo in Hanover (Stand E13, Hall 9). If a mobile phone rings during a meeting,
its owner often has to dig it out before it can be muted. A more discreet method would be to decline the incoming call by pressing on one of your fingers.
Computer scientists at Saarland University are studying the potential use of the human body as a touch sensitive surface for controlling mobile devices.
They have developed flexible silicone rubber stickers with pressure-sensitive sensors that fit snugly to the skin.
users can use their own body to control mobile devices. Because of the flexible material used, the sensors can be manufactured in a variety of shapes, sizes and personalized designs.
The research team will be presenting the Skinproject from March 16th to March 20th at the Cebit computer expo in Hanover (Stand E13,
Hall 9). Someone wearing a smartwatch can look at a calendar or receive e-mails without having to reach further than their wrist.
However, the interaction area offered by the watch face is fixed both and small making it difficult to actually hit individual buttons with adequate precision.
A method currently being developed by a team of computer scientists from Saarbrücken in collaboration with researchers from Carnegie mellon University in the USA may provide a solution to this problem.
They have developed touch-sensitive stickers made from flexible silicone and electrically conducting sensors that can be worn on the skin.
The stickers can act as an input space that receives and executes commands and thus controls mobile devices.
Depending on the type of skin sticker used, applying pressure to the sticker could, for example, answer an incoming call or adjust the volume of a music player. he stickers allow us to enlarge the input space accessible to the user as they can be attached practically anywhere on the body,
explains Martin Weigel, a Phd student in the team led by Jürgen Steimle at the Cluster of Excellence at Saarland University.
The Skinapproach enables the human body to become more closely connected to technology. Users can also design their iskin patches on a computer beforehand to suit their individual tastes. simple graphics program is need all you,
says Weigel. One sticker for instance, is based on musical notation, another is circular in shape like an LP.
The silicone used to fabricate the sensor patches makes them flexible and stretchable. his makes them easier to use in an everyday environment.
as they are attached to the skin with a biocompatible, medical-grade adhesive. Users can therefore decide where they want to position the sensor patch
and how long they want to wear it. In addition to controlling music or phone calls the iskin technology could be used for many other applications.
For example, a keyboard sticker could be used to type and send messages. Currently the sensor stickers are connected via cable to a computer system.
According to Steimle, inbuilt microchips may in future allow the skin-worn sensor patches to communicate wirelessly with other mobile devices.
The publication about Skinwon the est Paper Awardat the SIGCHI conference, which ranks among the most important conferences within the research area of human computer interaction.
The researchers will present their project at the SIGCHI conference in April in Seoul Korea, and beforehand at the computer expo Cebit,
which takes place from the 16th until the 20th of March in Hannover (hall 9, booth E13) 0
#A faster, more accurate and more flexible technique for creating artificial DNA A new technique for creating artificial DNA that is faster,
more accurate and more flexible than existing methods has been developed by scientists at Imperial College London("BASIC:
a new Biopart Assembly Standard for Idempotent Cloning provides accurate, single-tier DNA assembly for synthetic biology".
"The new system called BASIC is a major advance for the field of synthetic biology, which designs and builds organisms able to make useful products such as medicines, energy, food, materials and chemicals.
To engineer new organisms, scientists build artificial genes from individual molecules and then put these together to create larger genetic constructs which,
BASIC, created by researchers from Imperials Centre for Synthetic biology & Innovation combines the best features of the most popular methods while overcoming their limitations,
because it can draw on a large database of standardised parts, which can be produced in bulk and stored for use as required,
which is promoting the adoption of synthetic biology by industry. Two industrial partners Dr Reddys and Isogenica are also already making use of BASIC in their research laboratories.
Professor Paul Freemont, co-Director of the Centre for Synthetic biology & Innovation, says: This system is an exciting development for the field of synthetic biology.
If we are to make significant advances in this area of research, it is vital to be able to assemble DNA rapidly in multiple variations,
Professor Stephen Chambers, CEO of Synbicite, says: The way BASIC has been designed lends itself very well to automation and high throughput processes,
which is the future of synthetic biology. If innovations in the field are to be translated into the marketplace,
and will be one of the first protocols to be used in our new, fully automated platform for synthetic biology,
Images showing the development of a human tumour implanted into a mouse, produced using the new device,
have been published in Nature Photonics("Deep in vivo photoacoustic imaging of mammalian tissues using a tyrosinase-based genetic reporter").
developed by researchers at University college London with funding from the Biotechnology & Biological sciences Research Council (BBSRC),
combines a highly sensitive imaging system with a method of genetically engineering cells to produce a pigment
Professor Martin Pule, University college London, one of the lead researchers on the study said:""Anything you could possibly think of in terms of imaging complex activity within an organ,
Whether it's watching immune cells attack a tumour or an infection, or watching an organ develop embryonically,
function, or react to damage or stress, all of these things you could observe at an organ level,
This device, based on a technique called photoacoustic imaging, allows scientists to distinguish features as small as clusters of tens of cells at depths close to a centimetre below the skin.
the enzyme that produces the pigment melanin in skin. This turns the cells dark brown so they absorb light from the laser
The researchers are now developing other pigments to increase the palette of colours available to label different parts of an organ,
Professor Melanie Welham BBSRC Executive director, Science, said:""Fundamental bioscience research is vital to reveal the biological mechanisms underlying normal physiology across the lifespan.
Techniques such as this, which allow us to study the development and function of organs, have the potential to contribute to our understanding of human physiology
#An important step in artificial intelligence with metal-oxide memristors In what marks a significant step forward for artificial intelligence,
researchers at UC Santa barbara have demonstrated the functionality of a simple artificial neural circuit (Nature,"Training and operation of an integrated neuromorphic network based on metal-oxide memristors").
but important step, said Dmitri Strukov, a professor of electrical and computer engineering. With time and further progress, the circuitry may eventually be expanded
what computers would require far more time and energy to perform. What are these functions? Well, youe performing some of them right now.
As you read this, your brain is making countless split-second decisions about the letters and symbols you see,
Key to this technology is the memristor (a combination of emoryand esistor, an electronic component whose resistance changes depending on the direction of the flow of the electrical charge.
Unlike conventional transistors, which rely on the drift and diffusion of electrons and their holes through semiconducting material,
the resulting device would have to be loaded enormous with multitudes of transistors that would require far more energy. lassical computers will always find an ineluctable limit to efficient brain-like computation in their very architecture,
said lead researcher Prezioso. his memristor-based technology relies on a completely different way inspired by biological brain to carry on computation.
however, many more memristors would be required to build more complex neural networks to do the same kinds of things we can do with barely any effort and energy,
Potential applications already exist for this emerging technology, such as medical imaging, the improvement of navigation systems or even for searches based on images rather than on text.
The energy-efficient compact circuitry the researchers are striving to create would also go a long way toward creating the kind of high-performance computers
and memory storage devices users will continue to seek long after the proliferation of digital transistors predicted by Moore Law becomes too unwieldy for conventional electronics. he exciting thing is that,
and giving a serious boost to future computers, said Prezioso. In the meantime, the researchers will continue to improve the performance of the memristors,
The very next step would be to integrate a memristor neural network with conventional semiconductor technology,
and Technology (NIST) has developed a technique for creating nanoscale whispering galleries for electrons in graphene. The development opens the way to building devices that focus
and resonators (like the body of a guitar) amplify sound. They reported their findings in the May 8, 2015,
"An international research group led by scientists at NIST has developed a technique for creating nanoscale whispering galleries for electrons in graphene.
The researchers used the voltage from a scanning tunneling microscope (right) to push graphene electrons out of a nanoscale area to create the whispering gallery (represented by the protuberances on the left),
which is like a circular wall of mirrors to the electron. Image: Jon Wyrick, CNST/NIST) In some structures,
such as the dome in St pauls Cathedral in London, a person standing near a curved wall can hear the faintest sound made along any other part of that wall.
occurs because sound waves will travel along a curved surface much farther than they will along a flat one.
The cool thing is made that we a nanometer scale electronic analogue of a classical wave effect
Ever since graphene, a single layer of carbon atoms arranged in a honeycomb lattice, was created first in 2004,
ability to conduct electricity and heat and many interesting optical, magnetic and chemical properties. However, early studies of the behavior of electrons in graphene were hampered by defects in the material.
When moving electrons encounter a potential barrier in conventional semiconductors it takes an increase in energy for the electron to continue flowing.
As a result, they are reflected often, just as one would expect from a ball-like particle.
the research team used the voltage from a scanning tunneling microscope (STM) to push some of them out of a nanoscale-sized area.
which is like a circular wall of mirrors to the electron. An electron that hits the step head-on can tunnel straight through it,
and travel along the sides of the curved walls of the barrier until they began to interfere with one another,
creating a nanoscale electronic whispering gallery mode. The team can control the size and strength, i e.,
Graphene-based quantum electronic resonators and lenses have as yet untold potential but if conventional optics is any guide,
Fabrication and measurement of the device was performed at NISTS Center for Nanoscale Science and Technology (CNST), a national user facility available to researchers from industry, academia and government t
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