A new device that combines two microimaging technologies can reveal both the detailed anatomy of arterial linings and biological activities that, in coronary arteries, could indicate the risk of heart attacks or the formation of clots in arterial stents. In their report receiving early online release in Nature Medicine, Massachusetts General Hospital (MGH) investigators describe using an intra-arterial catheter combining both optical frequency-domain imaging (OFDI) and near-infrared fluorescence (NIRF) imaging to obtain simultaneous structural and molecular images of internal arterial surfaces in rabbits.
"The ability to measure both microstructural and molecular information from the same location in the artery wall could provide a much better diagnostic tool for assessing vascular pathology, information that is highly relevant for diagnosingcoronary artery disease, vulnerable plaque and evaluating stent healing," says Gary Tearney, MD, PhD, of the Wellman Center for Photomedicine and the MGH Pathology Department, co-senior author of the article.
Developed at the Wellman Center, OFDI utilizes a fiberoptic probe with a constantly rotating laser tip to create detailed molecular images of interior surfaces such as arterial walls. While OFDI can be used to guide procedures like coronary artery angioplasty and to confirm the correct positioning of metal stents inserted to keep cleared arteries open, its ability to determine important details of stent healing is limited. Properly healed stents become covered with endothelium, the same tissue that normally coats the arterial surface; but stents can become coated with the clot-inducing protein fibrin, which may put patients at risk for stent thrombosis – a clot that blocks bloodflow through the stent – and OFDI cannot determine the molecular composition of tissue covering a stent.
Intravascular NIRF technology was developed in the MGH Cardiovascular Research Center (CVRC), in collaboration with colleagues at the TechnicalUniversity of Munich, and uses special imaging agents to detect cells and molecules involved in vascular processes like clotting and inflammation. Recognizing the potential advantage of combining both technologies, the Wellman researchers worked with the MGH-CVRC team, led by Farouc Jaffer, MD, PhD, of the MGH Heart Center to develop an integrated OFDI-NIRF imaging system incorporated in the same intravascular probe used for OFDI alone.
The team first confirmed that the system could provide detailed structural images of a stent implanted in a cadaveric human coronary artery and could accurately identify the presence of fibrin on the stent. In a series of experiments in living rabbits, the OFDI-NIRF system was able to detect fibrin on implanted stents – including areas where it was not detected by OFDI alone – and to identify the presence of both atherosclerotic plaques and enzymatic activity associated with inflammation and plaque rupture. The enzyme signal detected by NIRF was not uniform throughout the imaged plaques, indicating biological differences that could be relevant to prognosis and treatment planning.
"At present we are not able to predict which patients may develop stent thrombosis, but integrated OFDI-NIRF can assess many key factors linked to the risk of clot formation," says Jaffer, co-senior author of the Nature Medicinereport. "If OFDI-NIRF is validated in clinical studies, patients at risk for stent thrombosis could undergo a 'stent checkup' to determine how well the stent is healing. Patients with unhealed stents could be advised to take or continue taking specific anti-clotting medications. Patients with well-healed stents, on the other hand, could potentially discontinue anti-clotting medications, which can cause excess bleeding." Clinical adoption of the integrated technology will require FDA approval of the molecular contrast agents used in NIRF.
Lighting has today announced the launch of a new, complete and innovative water disinfection solution, Philips InstantTrust. This solution is based on cutting-edge disinfection technology optimized for point-of-use applications. For the first time water can be disinfected instantly, efficiently and independent of water temperature.
Many consumers are concerned about the quality of drinking water, because the microorganisms present in water can make them ill. In emerging countries these concerns may be due to the water infrastructure, but also in western countries incidents can cause contamination with microorganisms. In North America alone 85% of child sickness and 65% of adult diseases are a result of water borne viruses and bacteria.
The new Philips InstantTrust solution can be integrated into any point-of use application including taps, water pitchers, under-the-sink water filters and portable counter-top systems. It solves many of the limitations of current UV disinfection technology and enables equipment manufacturers to provide consumers with access to safe drinking water: anytime, anywhere.
Philips InstantTrust is so compact in its size that it allows manufacturers to integrate the solution into smaller equipment than ever before and gives them stylistic freedom to design sleek products ideal for the small and modern home. Furthermore, the revolutionary solution works instantly to produce safe water from the first second onwards, eliminating waiting time. It is unique due to its ability to work independently of water temperature and because it can be used for integration into both hot and cold water systems. Philips InstantTrust is ideal for instant disinfection of small quantities of cold water (up to flows of approximately 4 liters/minute).
Frank Kauffmann, General Manager Special Lighting said: “We are very proud to be launching this unique, state-of-the-art UV disinfection technology today: It is a testament to our continued commitment to developing innovative technologies that help enhance the health and quality of people’s lives.”
Ernest Sanderse, Marketing Manager UV Purification: “Thanks to this innovation safe water is now always within reach: anytime, anywhere. We are dedicated to working with leading equipment manufacturers of end-use products to make this technology available for people around the world.”
Philips Lighting has been at the forefront of UV technology for many years and has helped equipment manufacturers across different sectors including residential water, municipal drinking and waste water, industrial water, swimming pools and fish ponds to design effective water purification equipment by developing innovative and reliable UV solutions.
Anyone who uses multithreaded computer programs -- and that's all of us, as these are the programs that power nearly all software applications including Office, Windows, MacOS, and Google Chrome Browser, and web services like Google Search, Microsoft Bing, and iCloud, -- knows well the frustration of computer crashes, bugs, and other aggravating problems. The most widely used method to harness the power we require from multicore processors, multithreaded programs can be difficult for programmers to get right and they often contain elusive bugs called races. Data races can cause very serious problems, like the software bug that set off the 2003 power blackout in the Northeast. Now there is a new system that will combat this problem.
Peregrine, a new software system developed by a team of researchers at Columbia Engineering School, led by Assistant Professor of Computer Science Junfeng Yang, will improve the reliability and security of multithreaded programs, benefiting virtually every computer user across the globe. Peregrine can be used by software vendors like Microsoft and Apple and web service providers like Google and Facebook, to provide reliable services to computer users. This new research was published in the 23rd ACM Symposium on Operating Systems Principles, considered to be the most prestigious systems conference held each year, and presented by Yang's graduate student Heming Cui at Cascais, Portugal, on Oct. 26. The paper can be found online.
"Multithreaded programs are becoming more and more critical and pervasive," says Professor Yang."But these programs are nondeterministic, so running them is like tossing a coin or rolling dice -- sometimes we get correct results, and sometimes we get wrong results or the program crashes. Our main finding in developing Peregrine is that we can make threads deterministic in an efficient and stable way: Peregrine can compute a plan for allowing when and where a thread can "change lanes" and can then place barriers between the lanes, allowing threads to change lanes only at fixed locations, following a fixed order. This prevents the random collisions that can occur in a nondeterministic system.
"Once Peregrine computes a good plan without collisions for one group of threads," adds Yang, "it can reuse the plan on subsequent groups to avoid the cost of computing a new plan for each new group. This approach matches our natural tendency to follow familiar routes so we can avoid both potential hazards in unknown routes and efforts to find a new route."
Yang notes that in contrast to many earlier systems that address only resultant problems but not the root cause, Peregrine addresses nondeterminism -- a system that is unpredictable as each input has multiple potential outcomes -- and thus simultaneously addresses all the problems that are caused by nondeterminism.
Peregrine also deals with data races or bugs, unlike most previous efforts that do not provide such fine-grained control over the execution of a program. And it's very fast -- many earlier systems may slow down the execution of a program by up to ten times. Peregrine is also a practical system that works with current hardware and programming languages -- it does not require new hardware or new languages, all of which can take years to develop. It reuses execution plans, whereas some previous work makes a different plan for each group of threads: as Yang points out, "The more plans one makes, the more likely some plans have errors and will lead to collisions."
"Today's software systems are large, complex, and plagued with errors, some of which have caused critical system failures and exploits," adds Yang. "My research is focused on creating effective tools to improve the reliability and security of real software systems. I'm excited about this area because it has the potential to make the cyberspace a better place and benefit every government, business, and individual who uses computers."
Researchers working out of the National Institute of Advanced Industrial Science and Technology (AIST) in Tsukuba, Japan have developed a means for printing thin film transistors using InkJet technology. The team describes the process in their paper published in Nature.
To get around the problem of self-crystallization, inherent in other InkJet/transistor making processes, which result in spreading effects that make it difficult to print uniformly, the team instead chose to use a two step process, whereby one type of ink is sprayed first onto a substrate and is then followed by another immediately afterwards, directly on top of the first; the two then mix, creating an environment whereby one single crisp and sharp crystal grows and adheres to the material it is printed on.
The first ink applied is a liquid (anhydrous dimethylformamide) that holds a semiconductor but is not soluble. The second is comprised of an organic semiconductor in a solvent. After the first is sprayed onto the substrate, followed by a shot of the second, the two then mix naturally, and then, from a single point in the mixture a tiny crystal begins to grow, and keeps on growing until the entire pool of ink is consumed, resulting in a thin film (30-200nm thick) of C8BTBT affixed to the substrate. After printing a complete pattern with their new process onto a substrate, other components were added to complete the transistor.
Researchers are looking at InkJet sprayed transistor technologies in the hope that it could lead to a whole host of products that are based on bendable substrates, such as flexible displays, solar cells, large sheets of sensors, or true ePaper, and because it would offer a lowered cost of production compared to traditional silicon based products.
The authors say their new method offers exceptionally uniform creation of the crystals, a development that could lead InkJet sprayed technology out of the lab and into real world products. The team next plans to look into whether their new technique could also be used to create metal wires which would allow for a transistor to be made entirely from InkJet spraying technology.
“We’ve discovered a way to change the three-dimensional structure of a well-established semiconductor material to enable new optical properties while maintaining its very attractive electrical properties,” said Paul Braun, a professor of materials science and engineering and of chemistry who led the research effort.
The team published its advance in the journal Nature Materials.
Photonic crystals are materials that can control or manipulate light in unexpected ways thanks to their unique physical structures. Photonic crystals can induce unusual phenomena and affect photon behavior in ways that traditional optical materials and devices can’t. They are popular materials of study for applications in lasers, solar energy, LEDs, metamaterials and more.
Using an epitaxial approach, researchers developed a 3-D photonic crystal LED, the first such optoelectronic device. | Graphic by Eric Nelson
However, previous attempts at making 3-D photonic crystals have resulted in devices that are only optically active – that is, they can direct light – but not electronically active, so they can’t turn electricity to light or vice versa.
To create a 3-D photonic crystal that is both electronically and optically active, the researchers started with a template of tiny spheres packed together. Then, they deposit gallium arsenide (GaAs), a widely used semiconductor, through the template, filling in the gaps between the spheres.
The GaAs grows as a single crystal from the bottom up, a process called epitaxy. Epitaxy is common in industry to create flat, two-dimensional films of single-crystal semiconductors, but Braun’s group developed a way to apply it to an intricate three-dimensional structure.
“The key discovery here was that we grew single-crystal semiconductor through this complex template,” said Braun, who also is affiliated with the Beckman Institute for Advanced Science and Technology and with the Frederick Seitz Materials Research Laboratory at Illinois. “Gallium arsenide wants to grow as a film on the substrate from the bottom up, but it runs into the template and goes around it. It’s almost as though the template is filling up with water. As long as you keep growing GaAs, it keeps filling the template from the bottom up until you reach the top surface.”
The Illinois team’s photonic crystal has both properties.
“With our approach to fabricating photonic crystals, there’s a lot of potential to optimize electronic and optical properties simultaneously,” said Erik Nelson, a former graduate student in Braun’s lab who now is a postdoctoral researcher at Harvard University. “It gives you the opportunity to control light in ways that are very unique –to control the way it’s emitted and absorbed or how it propagates.”
To create a 3-D photonic crystal that is both electronically and optically active, the researchers started with a template of tiny spheres packed together. Then, they deposit gallium arsenide (GaAs), a widely used semiconductor, through the template, filling in the gaps between the spheres.
The GaAs grows as a single crystal from the bottom up, a process called epitaxy. Epitaxy is common in industry to create flat, two-dimensional films of single-crystal semiconductors, but Braun’s group developed a way to apply it to an intricate three-dimensional structure.
“The key discovery here was that we grew single-crystal semiconductor through this complex template,” said Braun, who also is affiliated with the Beckman Institute for Advanced Science and Technology and with the Frederick Seitz Materials Research Laboratory at Illinois. “Gallium arsenide wants to grow as a film on the substrate from the bottom up, but it runs into the template and goes around it. It’s almost as though the template is filling up with water. As long as you keep growing GaAs, it keeps filling the template from the bottom up until you reach the top surface.”
The epitaxial approach eliminates many of the defects introduced by top-down fabrication methods, a popular pathway for creating 3-D photonic structures. Another advantage is the ease of creating layered heterostructures. For example, a quantum well layer could be introduced into the photonic crystal by partially filling the template with GaAs and then briefly switching the vapor stream to another material.
Once the template is full, the researchers remove the spheres, leaving a complex, porous 3-D structure of single-crystal semiconductor. Then they coat the entire structure with a very thin layer of a semiconductor with a wider bandgap to improve performance and prevent surface recombination.
To test their technique, the group built a 3-D photonic crystal LED – the first such working device.
Now, Braun’s group is working to optimize the structure for specific applications. The LED demonstrates that the concept produces functional devices, but by tweaking the structure or using other semiconductor materials, researchers can improve solar collection or target specific wavelengths for metamaterials applications or low-threshold lasers.
“From this point on, it’s a matter of changing the device geometry to achieve whatever properties you want,” Nelson said. “It really opens up a whole new area of research into extremely efficient or novel energy devices.”
The U.S. Department of Energy and the Army Research Office supported this work. Other Illinois faculty involved in the project are electrical and computer engineering professors James Coleman and Xiuling Li, and materials science and engineering professor John Rogers.
Penn Fraser Jillette (born March 5, 1955) is an American magician, comedian, illusionist, juggler, bassist and a best-selling author known for his work with fellow illusionist Teller in the team Penn & Teller, and advocacy of atheism, libertarian philosophy, free-market economics, and scientific skepticism.
Jillette was born in Greenfield, Massachusetts. His mother, Valda R. Jillette (née Parks) (November 8, 1909—January 1, 2000), was a secretary, and his father, Samuel H. Jillette (March 14, 1912—February 14, 1999), worked at Greenfield's Franklin County Jail. Jillette became disenchanted with traditional illusionist acts that presented the craft as authentic magic, such as The Amazing Kreskin on The Tonight Show Starring Johnny Carson. At age eighteen, he saw a show by illusionist James Randi, and became enamored of his approach to magic that openly acknowledged deception as entertainment rather than a mysterious supernatural power. Jillette regularly acknowledges Randi as the one person on the planet he loves the most besides members of his family.
Jillette worked with high school classmate Michael Moschen in developing and performing a juggling act during the years immediately following their 1973 graduation. In 1974, Jillette graduated from Ringling Brothers and Barnum & Bailey Clown College. That same year, he was introduced to Teller by Weir Chrisimer, a mutual friend. The three then formed a three-person act called Asparagus Valley Cultural Society which played in Amherst, Massachusetts and San Francisco, California. In 1981, he and Teller teamed up as Penn & Teller, and went on to do a successful on- and Off Broadway show called "Penn & Teller" that toured nationally.
They are a daily essential for millions of Britons hoping to ward off ill-health. But despite the millions of pounds spent on vitamin pills, they do nothing for our health, according to a major study.
Researchers spent more than six years following 8,000 people and found that those taking supplements were just as likely to have developed cancer or heart disease as those who took an identical-looking dummy pill.
And when they were questioned on how healthy they felt, there was hardly any difference between the two groups.
Experts said the study – one of the most extensive carried out into vitamin pills – suggested that millions of consumers may be wasting their money on supplements. Many users fall into the category of the ‘worried well’ – healthy adults who believe the pills will insure them against deadly illnesses – according to Catherine Collins, chief dietician at St George’s Hospital in London.
She said: ‘It’s the worried well who are taking these pills to try and protect themselves against Alzheimer’s disease, heart attacks and strokes.
‘But they are wasting their money. This was a large study following people up for a long period of time assessing everything from their mobility and blood pressure to whether they were happy or felt pain.’
Multi-vitamin supplements have become increasingly popular as a quick and easy way of topping up the body’s nutrient levels. But a series of studies have indicated that, for some people, they could actually be harmful.
Two studies published last year suggested supplements could raise the risk of cancer.
One found pills containing vitamin E, ascorbic acid, beta-carotene, selenium and zinc increased the risk of malignant melanoma, the deadliest form of skin cancer, four-fold.
The other discovered women on a daily multi-vitamin pill increased their risk of breast cancer by up to 20 per cent.
While the evidence that vitamins can do harm is still limited, the latest study seems to confirm that many people are at the very least taking them unnecessarily.
A team of French researchers, led by experts at Nancy University, tracked 8,112 volunteers who took either a placebo capsule, or one containing vitamin C, vitamin E, beta-carotene, selenium and zinc, every day for just over six years.
They assessed the state of their health at the beginning and end of the trial, taking a quality of life survey designed to measure everything from mobility and pain to vitality and mental health.
When researchers analysed how many in each group had gone on to develop serious illnesses over the years, they found little difference.
In the supplement group, 30.5 per cent of patients had suffered a major health ‘event’, such as cancer or heart disease.
In the placebo group, the rate was 30.4 per cent.
There were 120 cases of cancer in those taking vitamins, compared to 139 in the placebo group, and 65 heart disease cases, against 57 among the dummy pill users.
In a report on their findings, published in the International Journal of Epidemiology, the researchers said: ‘The perception that supplementation improves general well-being is not supported by this trial.’
Miss Collins said the results of the study ‘reinforce the idea that if you’re worried about your health and start taking multi-vitamins, you will still be worried about it six years later’.
But the Health Supplements Information Service, which is funded by supplements manufacturers, said the finding that vitamins had no impact on how people perceived their health was ‘to be expected’.
Spokeswoman Dr Carrie Ruxton said: ‘The role of vitamin supplements is to prevent deficiencies and make sure people are receiving their recommended levels.
‘They won’t have a measurable impact on how you feel on a day-to-day basis but what they are doing is topping up your recommended levels to the right amount. They are not meant to be a magic bullet.’
The team just unveiled a new photovoltaic energy conversion system that can be powered by heat, the sun’s rays, a hydrocarbon fuel, or a decaying radioisotope. The button-sized power generator that can also run three times longer than a lithium-ion battery of the same weight.
The science behind the device is not necessarily groundbreaking, as engineers have long used the surface of a material to convert heat into precisely tuned wavelengths of light. However MIT’s method to convert light and heat into electricity is much more efficient than previous versions.
Described in the journal Physical Review A, MIT’s breakthrough was enabled by a material with billions of nanoscale pits etched on its surface. When this pitted material absorbs heat, it radiates energy at precisely chosen wavelengths depending on the size of the pits. It is hoped that the technology may one day be used to generate power for spacecraft on long term missions where sunlight may not be available.
“Being able to convert heat from various sources into electricity without moving parts would bring huge benefits,” says Ivan Celanovic, research engineer in MIT’s Institute for Soldier Nanotechnologies (ISN), “especially if we could do it efficiently, relatively inexpensively and on a small scale.” Celanovic went on to say that he believes his team could triple the efficiency of their prototype, adding that “It’s a neat example of how fundamental research in materials can result in new performance that enables a whole spectrum of applications for efficient energy conversion.”
Considering that space firms are looking for new ways to power spacecraft efficiently now that the shuttle fleet has been retired, we imagine NASA will be among the many companies interested in this technology.
"At the heart of this technology is a new generation of high-brightness light-emitting diodes," says Harald Haas from the University of Edinburgh, UK. "Very simply, if the LED is on, you transmit a digital 1, if it's off you transmit a 0," Haas says. "They can be switched on and off very quickly, which gives nice opportunities for transmitting data."
It is possible to encode data in the light by varying the rate at which the LEDs flicker on and off to give different strings of 1s and 0s. The LED intensity is modulated so rapidly that human eyes cannot notice, so the output appears constant.
More sophisticated techniques could dramatically increase VLC data rates. Teams at the University of Oxford and the University of Edinburgh are focusing on parallel data transmission using arrays of LEDs, where each LED transmits a different data stream. Other groups are using mixtures of red, green and blue LEDs to alter the light's frequency, with each frequency encoding a different data channel.
Li-Fi, as it has been dubbed, has already achieved blisteringly high speeds in the lab. Researchers at the Heinrich Hertz Institute in Berlin, Germany, have reached data rates of over 500 megabytes per second using a standard white-light LED. Haas has set up a spin-off firm to sell a consumer VLC transmitter that is due for launch next year. It is capable of transmitting data at 100 MB/s - faster than most UK broadband connections.
Once established, VLC could solve some major communication problems. In 2009, the US Federal Communications Commission warned of a looming spectrum crisis: because our mobile devices are so data-hungry we will soon run out of radio-frequency bandwidth. Li-Fi could free up bandwidth, especially as much of the infrastructure is already in place.
"There are around 14 billion light bulbs worldwide, they just need to be replaced with LED ones that transmit data," says Haas. "We reckon VLC is a factor of ten cheaper than Wi-Fi." Because it uses light rather than radio-frequency signals, VLC could be used safely in aircraft, integrated into medical devices and hospitals where Wi-Fi is banned, or even underwater, where Wi-Fi doesn't work at all.
"The time is right for VLC, I strongly believe that," says Haas, who presented his work at TED Global in Edinburgh last week.
But some sound a cautious note about VLC's prospects. It only works in direct line of sight, for example, although this also makes it harder to intercept than Wi-Fi. "There has been a lot of early hype, and there are some very good applications," says Mark Leeson from the University of Warwick, UK. "But I'm doubtful it's a panacea. This isn't technology without a point, but I don't think it sweeps all before it, either."
The way things currently stand in the field of medicine, doctors often have to try out a number of treatments on any one patient, before (hopefully) finding one that works. This wastes both time and medications, and potentially endangers the patients, as they could have negative reactions to some drugs. In the future, however, all that experimenting may not be necessary. The pan-European IT Future of Medicine (ITFoM) project, a consortium of over 25 member organizations, is currently developing a system in which every person would have a computer model of themselves, that incorporated their own genome. Doctors could then run simulations with that model, to see how various courses of treatment would work on the actual person.
Needless to say, technology needs to advance before it becomes relatively easy to map individuals' genomes. That's why ITFoM is currently vying for EUR 1 billion (US$1.5 billion) in funding, from the European Future and Emerging Technologies flagship scheme. It has already received EUR 1.5 million (US$2.2 million) in preliminary funding. Once the 10-year project builds momentum and more organizations join, ITFoM's organizers are predicting that it could become one of the largest collaborative endeavors since the Apollo space program.
Besides genetic data, each person's computer model would incorporate physiological information such as allergies, past and current health issues, and congenital defects - some of the same things that are currently part of their health records. Not only would this allow physicians to virtually test different drugs on specific patients, but they could also asses how changes in things such as diet and exercise might affect them.
Great strides will have to be made in areas such as high-speed data acquisition and evaluation, dynamic storage and processing of that data into mathematical models, and the development of systems that can learn, predict and inform. The implications, however, could be huge.
"The greatest opportunities to improve outcomes in medicine seem likely to come from personalized medicine, the biological sciences are providing the insights required to support informed personalization, and advanced computational techniques are essential for making sense of the data that informs decision making," said Professor Norman Paton, of ITFoM member the University of Manchester. "This is a fantastic opportunity to bring together advances from these three rapidly developing areas to bring about a paradigm shift in medical practice."
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