#Nanotechnology helps protect patients from bone infection Leading scientists at the University of Sheffield have discovered nanotechnology could hold the key to preventing deep bone infections,
after developing a treatment which prevents bacteria and other harmful microorganisms growing. The pioneering research,
led by the University of Sheffield School of Clinical Dentistry, showed applying small quantities of antibiotic to the surface of medical devices,
from small dental implants to hip replacements, could protect patients from serious infection. Scientists used revolutionary nanotechnology to work on small polymer layers inside implants
which measure between 1 and 100 nanometers. Lead researcher Paul Hatton Professor of Biomaterials Sciences at the University of Sheffield, said:
icroorganisms can attach themselves to implants or replacements during surgery and once they grab onto a nonliving surface they are notoriously difficult to treat
which causes a lot of problems and discomfort for the patient. y making the actual surface of the hip replacement or dental implant inhospitable to these harmful microorganisms,
the risk of deep bone infection is reduced substantially. ur research shows that applying small quantities of antibiotic to a surface between the polymer layers
which make up each device could prevent not only the initial infection but secondary infection it is like getting between the layers of an onion skin.
Bone infection affects thousands of patients every year and results in a substantial cost to the NHS.
Treating the surface of medical devices would have a greater impact on patients considered at high risk of infection such as trauma victims from road traffic collisions or combat operations,
and those who have had previous bone infections. Professor Hatton added: eep bone infections associated with medical devices are increasing in number,
especially among the elderly. s well as improving the quality of life, this new application for nanotechnology could save health providers such as the NHS millions of pounds every year.
The study, funded by the European commission and the UK Engineering and Physical sciences Research Council, is published in Acta Biomaterialia("Functionalised nanoscale coatings using layer-by-layer assembly for imparting antibacterial properties to polylactide
-co-glycolide surfaces")c
#Expanding the code of life with new'letters'he DNA encoding all life On earth is made of four building blocks called nucleotides, commonly known as"letters,
"that line up in pairs and twist into a double helix. Now, two groups of scientists are reporting for the first time that two new nucleotides can do the same thing--raising the possibility that entirely new proteins could be created for medical uses.
Their two studies appear in ACS'Journal of the American Chemical Society("Structural Basis for a Six Nucleotide Genetic Alphabet".
"Synthetic biologists have been attempting for years to expand on nature's genetic"alphabet, "consisting of the nucleotide bases cytosine, guanine,
adenine and thymine--also represented by the letters"C,""G,""A"and"T,"respectively. But so far, the potential additions they've tested have shown limited promise.
For example, one duo pairs up but doesn't form a nice helix, an important criterion given that the bases would have to incorporate fairly seamlessly with the original four to be useful.
Millie M. Georgiadis, Steven A. Benner and colleagues from Indiana and Florida wanted to see if another potential set of letters"
Z"(6-amino-5-nitro-2 (1h)- pyridone) and"P"(2-amino-imidazo 1, 2-a-1, 3, 5-triazin-4 (8h
) one), would form a helix --and evolve. The researchers found that multiple Z-P pairs can contribute to a double helix,
just as C-G and A-t pairs do, with the same combination of flexibility and rigidity required for natural DNA to function.
They also showed that the Z-P pairs integrate well with conventional pairs and that six-letter GACTZP DNA can evolve.
The evolution of DNA containing the new building blocks endows the structures with new properties that could be useful in protein recognition n
#New anotechnology promises to make surface-enhanced Raman spectroscopy simpler (Nanowerk News) From airport security detecting explosives to art historians authenticating paintings,
society's thirst for powerful sensors is growing. Given that, few sensing techniques can match the buzz created by surface-enhanced Raman spectroscopy (SERS.
Discovered in the 1970s, SERS is a sensing technique prized for its ability to identify chemical and biological molecules in a wide range of fields.
An international research team led by University at Buffalo engineers has developed nanotechnology that promises to make SERS simpler and more affordable.
A Universal Surface-Enhanced Raman Spectroscopy Substrate for All Excitation Wavelengths"),the photonics advancement aims to improve our ability to detect trace amounts of molecules in diseases, chemical warfare agents, fraudulent
and a dielectric layer of silica or alumina. The dielectric separates the mirror with tiny metal nanoparticles randomly spaced at the top of the substrate.
Image: Qiaoqiang Gan)" The technology we're developing-a universal substrate for SERS-is a unique and, potentially, revolutionary feature.
and measure chemical and biological molecules using a broadband nanostructure that traps wide range of light,
"said Qiaoqiang Gan, UB assistant professor of electrical engineering and the study's lead author. Additional authors of the study are:
UB Phd candidates in electrical engineering Nan Zhang, Kai Liu, Haomin Song, Xie Zeng, Dengxin Ji and Alec Cheney;
and Suhua Jiang, associate professor of materials science, and Zhejun Liu, Phd candidate, both at Fudan University in China.
When a powerful laser interacts chemical and biological molecules, the process can excite vibrational modes of these molecules and produce inelastic scattering, also called Raman scattering, of light.
As the beam hits these molecules, it can produce photons that have a different frequency from the laser light.
While rich in details, the signal from scattering is weak and difficult to read without a very powerful laser.
SERS addresses the problem by utilizing a nanopatterned substrate that significantly enhances the light field at the surface and
and a dielectric layer of silica or alumina. The dielectric separates the mirror with tiny metal nanoparticles randomly spaced at the top of the substrate."
"It acts similar to a skeleton key. Instead of needing all these different substrates to measure Raman signals excited by different wavelengths,
"The ability to detect even smaller amounts of chemical and biological molecules could be helpful with biosensors that are used to detect cancer, Malaria, HIV and other illnesses."
And it could aid in the detection of chemical weapons s
#Exciton, exciton on the wall Researchers have observed, in metals for the first time, transient excitons the primary response of free electrons to light.
Here, the researchers discovered that the surface electrons of silver crystals can maintain the excitonic state more than 100 times longer than for the bulk metal,
enabling the excitons to be visualized experimentally by a newly developed multidimensional coherent spectroscopic technique (Nature Physics,"Transient excitons at metal surfaces").
"An interferogram showing the photoelectron energy vs. delay time between identical femtosecond pump and probe pulses,
which excite coherent three-photon photoemission at a single crystal silver surface. The interferogram is taken from a movie of photoelectron energy vs. momentum with one frame corresponding to a 50-attosecond delay.
The oscillations in the intensity of photoelectron signal for emission normal to the surface show how long light is trapped in the form of excitonic polarization during the coherent nonlinear interaction with the silver surface.
Detecting excitons in metals could provide clues on how light is converted into electrical and chemical energy in solar cells and plants.
This research may also provide ways to alter the function of metals in order to develop active elements for technologies such as optical communications by controlling how light is reflected from a metal.
The act of looking in a mirror is an everyday experience, but the quantum mechanical description behind this familiar phenomenon is still unknown.
When light reflects from a mirror, the light shakes the metals free electrons and the resulting acceleration of electrons creates a nearly perfect replica of the incident light providing a reflection.
Excitons, or particles of the light-matter interaction where light photons become temporarily entangled with electrons in molecules
and semiconductors, are known to be important to this process and others such as photosynthesis and optical communications.
studying and proving how excitons function in metals is difficult because they are extremely short-lived,
For the first time researchers have observed excitons at metallic surfaces that maintain the excitonic state 100 times longer than in the bulk metal,
This discovery sheds light on the primary excitonic response of solids which could allow quantum control of electrons in metals, semiconductors,
It also potentially allows for the generation of intense femotosecond electron pulses that could increase resolution for time-resolved electron microscopes that follow the motion of individual atoms
but the algorithms that handle sound and image processing are inspired by biology, says Professor yvind Brandtsegg at NTNU.
The machine is called self..It analyses sound through a system based on the human ear, and learns to recognize images using a digital model of how nerve cells in the brain handle sensory impressions.
It is designed to learn entirely from sensory input with no predefined knowledge database, so that its learning process will resemble that of a human child in early life.
Weve given it almost no predefined knowledge on purpose, Brandtsegg says. Axel Tidemann, self. and yvind Brandtsegg.
The machine is so complex that cooperation between different research fields is an absolute necessity to get it to work.
while Tidemann is at the Department of Computer and Information science. But they have overlapping interests.
But he is accomplished also an programmer and uses this knowledge to make music. Conversely, Tidemann made a drumming robot for his doctoral project.
Learning The robot has already been on display in Trondheim and Arendal where visitors were able to affect its learning.
It was in Trondheim for a month before Christmas, and in Arendal for two weeks in January.
The day before it was put on display in Trondheim, we worked through the night until eight in the morning.
Between the two displays, they worked on improving the way the robot organizes its memories.
It doesnt resemble any living organisms on purpose youre supposed to concentrate on its learning and the process behind it.
Based on this definition, computers that play chess, like IBMS Deep Blue, can be defined as intelligent,
and industrial work have been better at certain tasks than humans for decades. But these robots are far from being able to learn.
Not to mention doing things like running up stairs or jumping rope. There is also no machine that is as good at analysing a football match
Not in a vacuum Many artificial intelligence (AI) researchers, myself included, believe that true intelligence cant occur in a vacuum it is a consequence of adapting
and living in a dynamic environment, Tidemann explains. You could see our intelligence as a byproduct of our adaptability.
What is artificial life? These are the big questions, Tidemann says. But we believe that the right way to reach for the holy grail of AI is to implement biologically inspired models in a machine,
let it operate in a physical environment and see if we can observe intelligent behaviour.
#Powerful tool to control living cells at will by light A research group at the University of Tokyo has developed small photoswitching proteins that enable the highly accurate control of the activity of various intracellular molecules at will by irradiation with light.
preventing highly accurate optogenetic control. Postdoctoral fellow Fuun Kawano, Associate professor Moritoshi Sato and their research group at the Graduate school of Arts
and Sciences focused on a small fungal photoreceptor, named Vivid, to which they applied a variety of modifications using genetic engineering techniques.
As a result, the research group succeeded in developing a small photoswitching protein controllable with a temporal resolution of seconds by irradiation with blue light.
This new photoswitching protein offers a powerful tool for a deeper understanding of molecular processes in biological systems
and to conduct gene therapy at any tissue in living organisms n
#Trees are source for high-capacity, soft and elastic batteries (Nanowerk News) A method for making elastic high-capacity batteries from wood pulp was unveiled by researchers in Sweden and the US.
Using nanocellulose broken down from tree fibres, a team from KTH Royal Institute of technology and Stanford university produced an elastic,
foam-like battery material that can withstand shock and stress (Nature Communications, "Self-assembled three-dimensional and compressible interdigitated thin-film supercapacitors and batteries").
"This is a closeup of the soft battery, created with wood pulp nanocellulose. Image: Max Hamedi and Wallenberg Wood Science Center)" It is possible to make incredible materials from trees
and cellulose,"says Max Hamedi, who is a researcher at KTH and Harvard university. One benefit of the new wood-based aerogel material is that it can be used for three-dimensional structures."
"There are limits to how thin a battery can be, but that becomes less relevant in 3d,
"Hamedi says.""We are restricted no longer to two dimensions. We can build in three dimensions, enabling us to fit more electronics in a smaller space."
"A 3d structure enables storage of significantly more power in less space than is possible with conventional batteries,
he says.""Three-dimensional, porous materials have been regarded as an obstacle to building electrodes. But we have proven that this is not a problem.
In fact, this type of structure and material architecture allows flexibility and freedom in the design of batteries,"Hamedi.
The process for creating the material begins with breaking down tree fibres, making them roughly one million times thinner.
The nanocellulose is dissolved, frozen and then freeze-dried so that the moisture evaporates without passing through a liquid state.
Then the material goes through a process in which the molecules are stabilised so that the material does not collapse."
"The result is a material that is both strong, light and soft, "Hamedi says.""The material resembles foam in a mattress,
"The finished aerogel can then be treated with electronic properties.""We use a very precise technique,
which adds ink that conducts electricity within the aerogel. You can coat the entire surface within."
Similarly, a single cubic decimeter of the battery material would cover most of a football pitch,
While flexible and stretchable electronics already exist, the insensitivity to shock and impact are somewhat new."
"Hamedi says the aerogel batteries could be used in electric car bodies, as well as in clothing, providing the garment has a lining.
KTH Professor Lars Wgberg also has been involved, and his work on aerogels is in the basis for the invention of soft electronics.
Another partner is leading battery researcher, Professor Yi Cui from Stanford university y
#Intelligent bacteria for detecting disease Another step forward has just been taken in the area of synthetic biology.
Research teams from Inserm and CNRS (French National Centre for Scientific research) Montpellier, in association with Montpellier Regional University Hospital and Stanford university, have transformed bacteria into"secret agents"that can give warning of a disease based solely on the presence of characteristic molecules in the urine or blood.
To perform this feat, the researchers inserted the equivalent of a computer programme into the DNA of the bacterial cells.
The bacteria thus programmed detect the abnormal presence of glucose in the urine of diabetic patients.
This work published in the journal Science Translational Medicine("Detection of pathological biomarkers in human clinical samples via amplifying genetic switches
and logic gates"),is the first step in the use of programmable cells for medical diagnosis. Bacteria have a bad reputation,
and are considered often to be our enemies, causing many diseases such as tuberculosis or cholera. However, they can also be witnessed allies,
as by the growing numbers of research studies on our bacterial flora, or microbiota, which plays a key role in the working of the body.
Since the advent of biotechnology, researchers have modified bacteria to produce therapeutic drugs or antibiotics. In this novel study
they have actually become a diagnostic tool. Medical diagnosis is a major challenge for the early detection and subsequent monitoring of diseases."
"In vitro"diagnosis is based on the presence in physiological fluids (blood and urine, for example) of molecules characteristic for a particular disease.
Because of its noninvasiveness and ease of use, in vitro diagnosis is of great interest. However, in vitro tests are sometimes complex,
and require sophisticated technologies that are often available only in hospitals. This is where biological systems come into play.
Living cells are real nanomachines that can detect and process many signals and respond to them.
They are therefore obvious candidates for the development of powerful new diagnostic tests. However, they have to be provided with the appropriate"programme"for them to successfully accomplish the required tasks.
To do this Jérôme Bonnet's team in Montpellier's Centre for Structural Biochemistry (CBS) had the idea of using concepts from synthetic biology derived from electronics to construct genetic systems making it possible to"programme"living cells like a computer.
The transcriptor: the cornerstone of genetic programming The transistor is the central component of modern electronic systems.
It acts both as a switch and as a signal amplifier. In informatics, by combining several transistors, it is possible to construct"logic gates,
"i e. systems that respond to different signal combinations according to a predetermined logic. For example, a dual input"AND"logic gate will produce a signal
only if two input signals are present. All calculations completed by the electronic instruments we use every day, such as smartphones, rely on the use of transistors and logic gates.
During his postdoctoral fellowship at Stanford university in the United states Jérôme Bonnet invented a genetic transistor, the transcriptor.
The insertion of one or more transcriptors into bacteria transforms them into microscopic calculators. The electrical signals used in electronics are replaced by molecular signals that control gene expression.
It is thus now possible to implant simple genetic"programmes"into living cells in response to different combinations of molecules.
In this new work, the teams led by Jérôme Bonnet (CBS, Inserm U1054, CNRS UMR5048, Montpellier University), Franck Molina (Sysdiag, CNRS FRE 3690),
in association with Professor Eric Renard (Montpellier Regional University Hospital) and Drew Endy (Stanford university), applied this new technology to the detection of disease signals in clinical samples.
Clinical samples are complex environments in which it is difficult to detect signals. The authors used the transcriptor's amplification abilities to detect disease markers,
even if present in very small amounts. They also succeeded in storing the results of the test in the BACTERIAL DNA for several months.
The cells thus acquire the ability to perform different functions based on the presence of several markers,
opening the way to more accurate diagnostic tests that rely on detection of molecular"signatures"using different markers."
"We have standardised our method, and confirmed the robustness of our synthetic bacterial systems in clinical samples.
"says Alexis Courbet, a postgraduate student and first author of the article. As a proof of concept, the authors connected the genetic transistor to a bacterial system that responds to glucose,
and detected the abnormal presence of glucose in the urine of diabetic patients.""We have deposited the genetic components used in this work in the public domain to allow their unrestricted reuse by other public
or private researchers,"says Jérôme Bonnet.""Our work is focused presently on the engineering of artificial genetic systems that can be modified on demand to detect different molecular disease markers,
"he adds. In future, this work might also be applied to engineering the microbial flora in order to treat various diseases, especially intestinal diseases
#Bad air day? Low-cost pollution detectors to tackle air quality (w/video) Rush hour can be maddening.
Roads congested with traffic, public transport overcrowded, pavements heaving with people. But as well as the frustration, there a sinister side to the commute to work:
every breath you take could be adding to your risk of dying prematurely. Air pollution is the world largest single environmental health risk,
causing one in every eight deaths according to figures released last year by the World health organization. In the UK, 30,000 people die prematurely every year as a result of poor air quality,
and it costs the NHS and wider economy many billions each year. Traffic is the main culprit;
however, industry, domestic heating, power generation and burning are all contributors to pollution. And although the effects of pollution might be noticeable on a particularly smoggy day in a large city,
decades of exposure to only slightly higher levels a level we wouldn even notice can increase the risk of heart and lung diseases,
stroke and cancer. o work out the factors we should be worried about, and how we can intervene,
we need to rethink how we measure what going on, explains atmospheric scientist Professor Rod Jones. In the UK,
the Automatic Urban and Rural Network provides valuable hour-by-hour assessments of air quality.
But with only 171 monitoring stations at fixed sites nationwide large areas of the country remain uncovered.
Cost is the main limitation to developing a higher density network. With this in mind, Jonesteam, together with industrial partners and other universities, has been developing low-cost pollution detectors that are small enough to fit in your pocket,
stable enough to be installed as long-term static detectors around a city, and sensitive enough to detect small changes in air quality on a street-by-street basis. Their findings are now informing research projects aimed at improving air quality in major cities across Europe and North america.
The detectors are based on electrochemical sensors developed by project partner Alphasense for industrial safety where detection of toxic gases is needed at the parts-per-million level.
Monitoring air quality, however, requires parts-per-billion sensitivity. od and I had the confidence to believe that we could push our sensors to lower concentration levels,
and yet keep sensor costs low, says Dr John Saffell, Technical Director at Alphasense. The electrochemical devices the team developed can measure a wide range of pollutants,
including carbon monoxide, nitrogen dioxide and ozone, and they contain laser technology (developed by the University of Hertfordshire) to detect particulates from cars and lorries.
The addition of a GPS aerial allows air quality data and location to be mapped simultaneously.
A series of proof-of-concept studies followed. Personal devices were strapped to bicycles carried in cars and on buses,
and static devices were attached to lampposts and stationed at roadsides and at critical pollutant sites.
Fifty static devices were deployed also around London Heathrow Airport to record 22 months in the life of one of the busiest airports in the world. his was the first time technology like this had been tested in real-world situations as a high-density network,
says Jones, whose research at Heathrow was funded by the Natural environment Research Council. e could see huge variability in the exposure to pollution that people encounter as they move around the urban environment,
including otspots At Heathrow, we could see the airport turning on and off during the day, individual aircraft taxing
and taking off, and the effects of wind direction and the perimeter and M25 motorway road traffic.
They also discovered that sensor performance can create new opportunities. Jones and colleagues had to develop new smart software methods capable of separating local pollution events from background signals (pollution transported from long range)
and then to calibrate sensors across networks. Plus, they needed to move from being able to process the data after it has been collected to doing so in real-time.
The team has been working with Cambridge Environmental Research Consultants developers of world-leading air quality modelling software combining the unprecedented level of data created by the pollution-monitoring studies with model output to enhance the understanding
of pollution dispersion. For instance, sensors can be used to ask whether pollution along bus routes is improved by upgrading the exhaust processing on a bus fleet;
whether people living at the top of high-rise buildings experience more or less pollution than people at street level;
and to what extent changing a route to work, even from one side of the road to another, can affect an individual exposure.
Last year, the first commercial product (AQMESH) was released by UK manufacturer Geotech, which specialises in environmental monitoring equipment.
AQMESH uses Alphasense sensors to sample every 10 seconds, and data processing is carried out in real-time using cloud computing software similar to that developed by the Cambridge team. hen the project started in 2006 there were lone voices calling for a different approach to air quality monitoring,
explains Geotech Commercial Manager Amanda Randle. he Cambridge team and Alphasense helped us to understand the sensor full potential,
and now we have a product that can be placed exactly where it needed and provides valuable information.
And now the approach pioneered in Cambridge is helping to inform two of the largest air quality research studies of their kind.
The Airsensa project, run by the nonprofit organisation Change London, aims to deploy large numbers of air quality sensors across the whole of Greater london.
Alphasense is providing the sensors and supporting the engineering; and Cambridge is helping with data interpretation in a project
whose ethos is ou can manage what you can measure. Meanwhile, the methodologies the researchers developed in the pilot study at Heathrow are contributing to CITI-SENSE,
an EU-funded#12.7 million project providing wireless networks to eight cities across Europe. CITI-SENSE involves 27 partner institutions from academia,
the healthcare sector and industry (including Alphasense and Geotech), as well as the general public. Citizens across Europe will be involved in data collection through personal monitors
and in community decision-making to choose monitoring solutions for spaces such as schools and urban public spaces. ven though the effects of poor air quality on health are well known,
irrefutable evidence of the scale of the air quality issue and the benefits of ameliorating strategies is needed urgently,
adds Jones. ITI-SENSE provides a test-bed for both rolling out the new technologies that are coming online
and for drawing on the ower of the Citizento guide how society responds
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