#Pushing the limits of lensless imaging Using ultrafast beams of extreme ultraviolet light streaming at a 100,000 times a second, researchers from the Friedrich Schiller University Jena,
Germany, have pushed the boundaries of a well-established imaging technique. Not only did they make the highest resolution images ever achieved with this method at a given wavelength,
they also created images fast enough to be used in real time. Their new approach could be used to study everything from semiconductor chips to cancer cells.
The team will present their work at the Frontiers in Optics, The Optical Society's annual meeting and conference in San jose
California, USA, on 22 october 2015. The researchers'wanted to improve on a lensless imaging technique called coherent diffraction imaging,
which has been around since the 1980s. To take a picture with this method, scientists fire an X-ray or extreme ultraviolet laser at a target.
and find their way onto a detector, creating a diffraction pattern. By analyzing that pattern,
a computer then reconstructs the path those photons must have taken, which generates an image of the target material--all without the lens that's required in conventional microscopy."
"The computer does the imaging part--forget about the lens, "explained Michael Zürch, Friedrich Schiller University Jena, Germany and lead researcher."
"The computer emulates the lens.""Without a lens, the quality of the images primarily depends on the radiation source.
Traditionally, researchers use big, powerful X-ray beams like the one at the SLAC National Accelerator Laboratory in Menlo Park, California, USA.
the detector must be placed close to the target material--similar to placing a specimen close to a microscope to boost the magnification.
hardly any photons will bounce off the target at large enough angles to reach the detector.
Zürch and a team of researchers from Jena University used a special, custom-built ultrafast laser that fires extreme ultraviolet photons a hundred times faster than conventional table-top machines.
With more photons, at a wavelength of 33 nanometers, the researchers were able to make an image with a resolution of 26 nanometers--almost the theoretical limit."
When taking snapshots every second, the researchers reached a resolution below 80 nanometers. The prospect of high-resolution and real-time imaging using such a relatively small setup could lead to all kinds of applications,
Engineers can use this to hunt for tiny defects in semiconductor chips. Biologists can zoom in on the organelles that make up a cell.
Eventually he said, the researchers might be able to cut down on the exposure times even more
and cancer drugs Longing to find a cure for cancer, HIV and other yet incurable diseases,
each requiring preclinical and clinical testing with live subjects. How many chemical agents more to try? Moving at such rate, will we find the cure during our lifetime?
This approach will eventually provide more effective preclinical selection of drug candidates for the subsequent long-term and expensive clinical trial.
and vaccines against many dangerous diseases including HIV, hepatitis and cancer. The research, led by Yury Stebunov,
a scientist at the MIPT, was published in the ACS Applied materials & Interfaces("Highly sensitive and Selective Sensor Chips with Graphene oxide Linking Layer").
"Valentyn Volkov is the co-lead author, a visiting professor from the University of Southern Denmark.
Other co-authors are Olga Aftenieva and Aleksey Arsenin. New GO based biosensor chips exploit the phenomenon of surface plasmon resonance (SPR.
This is a photo of the state-of-art biosensor. Photo: Victor Anaskin) Surface plasmons are electromagnetic waves propagating along a metal-dielectric interface (e g.,
, gold/air) and having the amplitudes exponentially decaying in the neighbor media. Adsorption of molecules from solution onto a sensing surface alters the refractive index of the medium near this surface and,
therefore, changes the conditions of SPR. These sensors can detect biomolecule adsorption even at a few trillionth of a gram per millimeter square.
Owing to the above-mentioned merits, SPR biosensing is an outstanding platform to boost technological progress in the areas of medicine and biotechnology.
Nevertheless, the most distinctive feature of such sensors is an ability to"visualize"molecular interactions in real time."
"SPR biosensing is a valuable tool to investigate a wide range of biochemical reactions, estimate their chemical kinetics and other characteristics.
All this can be used efficiently for new drug discovery and validation. Widespread introduction of this method into preclinical trials will completely change the pharmaceutical industry.
With SPR sensors we just need to estimate the interaction between the drug and targets on the sensing surface,
"Stebunov said. Most commercial SPR sensor chips comprise a thin glass plate covered by gold layer with thiol
or polymer layers on it. The biosensing sensitivity depends on the properties of chip surface. Higher binding capacity for biomolecules increases the signal levels and accuracy of analysis. The last several years
novel carbon materials like graphene have attracted much attention due to their large surface area, low-cost fabrication, and interaction with a wide range of biomolecules.
Stebunov and the team from the Laboratory of Nanooptics and Plasmonics at MIPT created and patented a novel type of SPR sensor chips with the linking layer,
made of GO, a material with more attractive optical and chemical properties than pristine graphene. The GO"flakes"were deposited on the 35 nm gold layer.
Thereafter a layer of streptavidin protein was developed on GO FOR selective immobilization of biomolecules. Scientists conducted a series of experiments with the GO chip
the commercially available chip with carboxymethylated dextran (CMD) layer and the chip covered by monolayer graphene.
Experiments showed that the proposed GO chip has three times higher sensitivity than the CMD chip and 3. 7 times than the chip with pristine graphene.
These results mean, that the new chip needs much less molecules for detecting a compound
and can be used for analysis of chemical reactions with small drug molecules. An important advantage of the new GO based sensor chips is their simplicity
and low-cost fabrication compared to sensor chips that are already commercially available.""Our invention will help in drug development against viral and cancer diseases.
We are expecting that pharmaceutical industry will express a strong demand for our technology, "Stebunov said."
"The sensor can also find applications in food quality control, toxin screening, the sensor can significantly shorten a time for a clinical diagnostic,"researcher added.
However, the developed chip should go through a clinical trial for medical applications s
#Pioneering research develops new way to capture light-for the computers of tomorrow The key breakthrough will allow large quantities of data to be stored directly on an integrated optical chip,
rather than being processed and stored electronically, as happens today. Light is suited ideally to ultra-fast high-bandwidth data transfer,
and optical communications form an indispensable part of the IT world of today and tomorrow. However, a stumbling block so far has been the storage of large quantities of data directly on integrated chips in the optical domain.
While optical fibre cables and with them data transfer by means of light have long since become part of our everyday life,
data on a computer are processed still and stored electronically. The team of scientists from Germany and England have made a key breakthrough by capturing light on an integrated chip,
so developing the first permanent, all-optical on-chip memory. The research is published in leading scientific journal, Nature Photonics("On-chip integratable all-photonic nonvolatile multilevel memory".
"Professor David Wright, from the University of Exeters Engineering department said: With our prototype we have, for the first time,
a nanoscale integrated optical memory that could open up the route towards ultra-fast data processing and storage.
Our technology might also eventually be used to reproduce in computers the neural-type processing that is carried out by the human brain.
Professor Wolfram Pernice, from the Institute of Physics at Mnster University and who led the work said:
The all-optical memory devices we have developed provide opportunities that go far beyond any of the approaches to optical data processing available today.
Optical bits can be written in our system at frequencies of up to a gigahertz or more, adds Professor Harish Bhaskaran from Oxford university in England,
one of the lead co-authors, and our approach can define a new speed limit for future processors,
by delivering extremely fast on-chip optical data storage In addition, he says, the written state is preserved
when the power is removed, unlike most current on-chip memories. The scientists from Oxford Exeter, Karlsruhe and Mnster used so-called phase change materials at heart of their all-optical memory.
The distinguishing feature of these materials is that they radically change their optical properties depending their phase state,
i e. depending on the arrangement of the atoms in the material. This changeability between crystalline (regular) and amorphous (irregular) states allowed the team to store many bits in a single integrated nanoscale optical phase-change cell l
#3d printed scaffolds could enable the release biomolecules into the body with exceptional control (w/video) Tissue development is guided by gradients of biomolecules that direct the growth, migration,
and differentiation of cells. Biomedical engineers are interested in recreating these developmental gradients in adults to aid the growth of new tissue in areas that have sustained damage.
Now, researchers are one step closer to this goal thanks to the creation of new 3d printed scaffolds that enable researchers to release biomolecules into the body with exceptional control.
The scaffolds are the creation of NIBIB grantee Michael Mcalpine Ph d.,the Benjamin Mayhugh Associate professor of Mechanical engineering at the University of Minnesota.
The work is described in the August 12, 2015 issue of Nano Letters("3d printed Programmable Release Capsules".
"Above is a movie that shows an example of how the novel scaffolds are created. First, several layers of a gel that can be implanted into the body are printed onto a solid surface.
Next, tiny capsules containing red food dyen easy-to-visualize substitute for biomoleculesre printed on top of the gel.
This is followed by additional layers of gel and another layer of capsules, this time filled with blue food dye to represent a different type of biomolecule.
The layering pattern continues until the gel achieves a predetermined height. A critical component of each embedded capsule is the unique shell that surrounds it.
These shellshich are invisible to the naked eyeontain tiny gold rods that heat up when a laser is directed at them,
causing the capsule to burst and release its contents. How hot the gold rods become depends on matching their size with the color of the laser light used.
Thus, researchers can control when different types of biomolecules are released from the gel by varying the shell coatings of the capsules
and by employing different colored lasers. Because the capsules are 3d printed, they can be arranged within the gel in practically any design that can be created on a computer.
They can also be filled with a wide variety of biomolecules. ne can imagine filling the capsules with molecules such as medications
nucleic acids, enzymes, growth factors, cell markers and other functional proteins, says Mcalpine. Given the nonspecific nature of the gel, Mcalpine says it could be used to facilitate regeneration in a wide variety of tissues,
including blood vessels and even the heart. particularly far-reaching example would be the ability to guide the vascularization of artificial tissue by 3d printing capsules alongside stem cells,
IBIB goal is to help develop enabling technologies that could have big impacts on important medical problems,
#Ultrathin graphene oxide lens could revolutionise next-gen devices Researchers at Swinburne University of Technology, collaborating with Monash University,
have developed an ultrathin, flat, ultra-lightweight graphene oxide optical lens with unprecedented flexibility. The ultrathin lens enables potential applications in on-chip nanophotonics
and improves the conversion process of solar cells. It also opens up new avenues in: noninvasive 3d biomedical imaging photonic chips aerospace photonics micromachines laser tweezing the process of using lasers to trap tiny particles.
Optical lenses are indispensable components in almost all aspects of technology including imaging, sensing, communications, and medical diagnosis and treatment.
The rapid development in nano-optics and on-chip photonic systems has increased the demand for ultrathin flat lenses with three-dimensional subwavelength focusing capability the ability to see details of an object smaller than 200 nanometres.
narrow operational bandwidth and time consuming manufacturing processes. ur lens concept has a 3d subwavelength capability that is 30 times more efficient, able to tightly focus broadband light
Associate professor Baohua Jia, said. The researchers produced a film that is 300 times thinner than a sheet of paper by converting graphene oxide film to reduced graphene oxide through a photoreduction process. hese flexible graphene oxide lenses are mechanically robust
and maintain excellent focusing properties under high stress, lead author of the research, Phd candidate Xiaorui Zheng said. hey have the potential to revolutionise the next-generation integrated optical systems by making miniaturised and fully flexible photonics devices.
CMP Director, Professor Min Gu, said: he newly demonstrated laser nano-patterning method in graphene oxides holds the key to fast processing and programming of high capacity information for big data sectors.
Professor Dan Li, Co-director of the Monash Centre for Atomically Thin Material, which provided the graphene oxide film for this research said this work opens up a new high-tech application for graphene oxide
and demonstrates how nanotechnology can add significant value to natural graphite. The research is published in Nature Communications("Highly efficient and ultra-broadband graphene oxide ultrathin lenses with three-dimensional subwavelength focusing)
"and has been funded by the Australian Research Council under its Discovery Early Career Researcher Award, Discovery Project and Laureate Fellowship scheme
#Molecular diagnostics at home: Chemists design rapid, simple, inexpensive tests using DNA Chemists at the University of Montreal used DNA molecules to developed rapid,
inexpensive medical diagnostic tests that take only a few minutes to perform. Their findings, which will officially be published tomorrow in the Journal of the American Chemical Society("A highly selective electrochemical DNA-based sensor that employs steric hindrance effects to detect proteins directly in whole blood),
"may aid efforts to build point-of-care devices for quick medical diagnosis of various diseases ranging from cancer, allergies, autoimmune diseases, sexually transmitted diseases (STDS),
and many others. The new technology may also drastically impact global health due to its low cost and easiness of use, according to the research team.
when atoms are brought too close together-to detect a wide array of protein markers that are linked to various diseases.
The design was created by the research group of Alexis Vallée-Bélisle, a professor in the Department of chemistry at University of Montreal."
and the results sent back to the doctor's office. If we can move testing to the point of care,
which would enhance the effectiveness of medical interventions.""The key breakthrough underlying this new technology came by chance."
(or traffic) at the surface of a sensor, which drastically reduced the signal of our tests,
"said Sahar Mashid, postdoctoral scholar at the University of Montreal and first author of the study."
and limits the ability of this DNA to hybridize to its complementary strand located on the surface of a gold electrode.
Francesco Ricci, a professor at University of Rome Tor Vergata who also participated in this study,
explains that this novel signaling mechanism produces sufficient change in current to be measured using inexpensive electronics similar to those in the home glucose test meter used by diabetics to check their blood sugar.
allowing us to build inexpensive devices that could detect dozens of disease markers in less than five minutes in the doctor's office
including pathogen detection in food or water and therapeutic drug monitoring at home, a feature which could drastically improve the efficient of various class of drugs and treatments a
#Quantum dots light up under strain Semiconductor nanocrystals, or quantum dots, are sized tiny, nanometer particles with the ability to absorb light
and re-emit it with well-defined colors. With low-cost fabrication, long-term stability and a wide palette of colors, they have become a building blocks of the display technology,
improving the image quality of TV-SETS, tablets, and mobile phones. Exciting quantum dot applications are also emerging in the fields of green energy, optical sensing,
and bio-imaging. Prospects have become even more appealing after a publication was published in the journal Nature Communications last July("Band structure engineering via piezoelectric fields in strained anisotropic Cdse/Cds nanocrystals".
"An international team, formed by scientists at the Italian Institute of technology (Italy), the University Jaume I (Spain),
the IBM research lab Zurich (Switzerland) and the University of Milano-Bicocca (Italy) demonstrated a radically new approach to manipulate the light emission of quantum dots.
The traditional operating principle of quantum dots is based on the so-called quantum confinement effect, where the particle size determines the color of the emitted light.
The new strategy relies on a completely different physical mechanism; a strain induced electrical field inside the quantum dots.
It is created by growing a thick shell around the dots. This way, researchers were able to compress the inner core,
creating the intense internal electric field. This field now becomes the dominating factor in determining the emission properties.
The result is a new generation of quantum dots whose properties are enabled beyond those by quantum confinement alone.
This not only broadens the application scope of the well-known Cdse/Cds material set but also of other materials."
"Our findings add an important new degree of freedom to the development of quantum dot-based technological devices,
"the researchers say.""For example, the elapsed time between light absorption and emission can be extended to be more than 100 times longer compared to conventional quantum dots,
which opens the way towards optical memories and smart pixel new devices. The new material could also lead to optical sensors that are highly sensitive to the electrical field in the environment on the nanometer scale e
#Flexible microfluidic tactile sensor for robotics, electronics and healthcare applications A team of scientists from the National University of Singapore (NUS) Faculty of engineering has developed a wearable liquid-based microfluidic tactile
sensor that is small, thin, highly flexible and durable. Simple and cost-effective to produce, this novel device is very suitable for applications such as soft robotics, wearable consumer electronics, smart medical prosthetic devices,
as well as real-time healthcare monitoring. Tactile sensors are data acquisition devices that detect and measure a diversity of properties arising from physical interaction
and translate the information acquired to be analysed by an interconnected intelligent system. Conventional tactile sensors that are available today are typically rigid and in solid-state form
restricting various natural body movements when used and may also be subjected to plastic deformation and failure when pressure is exerted,
resulting in compromises in conformability, durability and overall robustness. Addressing the limitations of existing tactile sensors,
a team of researchers led by Professor Lim Chwee Teck from NUS Department of Biomedical engineering achieves a significant technological breakthrough by adopting a liquid-based pressure sensing method in the design of such sensors.
The team and their flexible sensor. Novel liquid-based pressure sensing element The newly developed microfluidic tactile sensor is fabricated on a flexible substrate like silicone rubber
and uses non-corrosive, nontoxic 2d nanomaterial suspension in liquid form, such as graphene oxide, as the pressure sensing element to recognise force-induced changes.
The NUS team has put the device through rigorous tests and also subjected it to various strenuous deformations, such as pressing, bending or stretching,
to validate the robustness and versatility of its invention. In fact, despite having placed the device under extreme abusive mechanical force,
such as running a car tyre over it, the electrical output was uniformed highly and there was no damage to the functionality of the device.
From idea to market The teams invention will further advance the applications of tactile sensors
which are utilised already increasingly for monitoring critical parameters in biomedical applications, especially for those that may come in contact with human skin
or where human movement is highly versatile. This liquid-based microfluidic tactile sensor, which is the first of its kind, addresses an existing gap in the market.
Being thin and flexible, the sensor gives a better fit when monitoring natural body movements.
Its small size, durability and ease of production further differentiate this novel device from conventional tactile sensors.
With the rapid advancement of healthcare and biomedical technologies as well as consumer electronics we are optimistic about new possibilities to commercialise our invention,
said Prof Lim. The NUS team has filed already a patent for its creation and is also keen to explore licensing partnerships in commercial development.
Earlier this year, it participated in Innovfest unbound, Asias premier technology transfer event organised by NUS Enterprise aimed at showcasing Asian innovation to a global audience and taking technology out to the market t
#Nanoparticles could boost effectiveness and reduce side effects of allergy shots Whether triggered by cats, bees, pollen or mites,
allergies are on the rise. And the bad news doesn stop there. The only current therapy that treats their causes is allergen-specific immunotherapy or allergy shots
which can cause severe side effects. Now, researchers report in Biomacromolecules("Biodegradable ph-Sensitive Poly (ethylene glycol) Nanocarriers for Allergen Encapsulation and Controlled Release")the development of a potentially better allergy shot that uses nanocarriers to address these unwanted issues.
For many people, allergies are a seasonal annoyance. But for others exposure to a particular allergen can cause adverse reactions such as itching, breathing problems or even death.
Allergy shots can reduce sensitivity by slowly ramping up exposure to the offending substance. But because these shots expose the body to the very thing people are allergic to,
the treatment itself can sometimes trigger reactions. In order to develop a safer, more direct, cause-based therapy,
researchers have developed nanoparticles that envelop an allergen and deliver it to specific cells. But these carriers degrade too slowly,
hampering the effectiveness of the treatment. Holger Frey and colleagues set out to overcome these limitations.
The researchers designed a new type of nanocarrier based on the biocompatible molecule poly (ethylene glycol or PEG, that releases its cargo only in targeted immune cells.
The nanocarrier degrades when it encounters the acidic part of these cells, simultaneously releasing the allergen
and getting rid of the packaging. The researchers say this approach also could be used for vaccines or immunotherapies for other conditions such as cancer or AIDS o
#Ultrafast lasers offer 3-D micropatterning of biocompatible hydrogels Tufts University biomedical engineers are using low energy,
ultrafast laser technology to make high-resolution, 3-D structures in silk protein hydrogels. The laser-based micropatterning represents a new approach to customized engineering of tissue and biomedical implants.
The work is reported in a paper in PNAS Early Edition published September 15 online before print.
Artificial tissue growth requires pores, or voids, to bring oxygen and nutrients to rapidly proliferating cells in the tissue scaffold.
Current patterning techniques allow for the production of random, micron-scale pores and the creation of channels that are hundreds of microns in diameter,
but there is little in between. The Tufts researchers used an ultrafast, femtosecond laser to generate scalable, high-resolution 3-D voids within silk protein hydrogel, a soft,
The laser treatment can be done while keeping the cell culture sealed and sterile. Unlike most 3-D printing, this technique does not require photoinitiators,
compounds that promote photoreactivity but are typically bio-incompatible.""Because the femtosecond laser pulses allow us to target specific regions without any damage to the immediate surroundings,
Ph d. Omenetto is associate dean for research, professor of biomedical engineering and Frank C. Doble professor at Tufts School of engineering and also holds an appointment in physics in the School of arts and Sciences.
The research team reported similar results in vitro and in a preliminary in vivo study in mice e
#Chip-based technology enables reliable direct detection of Ebola virus A team led by researchers at UC Santa cruz has developed chip-based technology for reliable detection of Ebola virus and other viral pathogens.
accurate detection of Ebola infections is needed to control outbreaks. Laboratory tests using preparations of Ebola virus
The current gold standard for Ebola virus detection relies on a method called polymerase chain reaction (PCR) to amplify the virus's genetic material for detection.
Because PCR works on DNA molecules and Ebola is an RNA VIRUS, the reverse transcriptase enzyme is used to make DNA copies of the VIRAL RNA prior to PCR amplification and detection."
"said senior author Holger Schmidt, the Kapany Professor of Optoelectronics at UC Santa cruz.""We're detecting the nucleic acids directly,
Adding a"preconcentration"step during sample processing on the microfluidic chip extended the limit of detection well beyond that achieved by other chip-based approaches,
Schmidt's lab at UC Santa cruz worked with researchers at Brigham Young University and UC Berkeley to develop the system.
Virologists at Texas Biomedical Research Institute in San antonio prepared the viral samples for testing. The system combines two small chips, a microfluidic chip for sample preparation and an optofluidic chip for optical detection.
For over a decade, Schmidt and his collaborators have been developing optofluidic chip technology for optical analysis of single molecules as they pass through a tiny fluid-filled channel on the chip.
The microfluidic chip for sample processing can be integrated as a second layer next to or on top of the optofluidic chip.
Schmidt's lab designed and built the microfluidic chip in collaboration with coauthor Richard Mathies at UC Berkeley who pioneered this technology.
It is made of a silicon-based polymer, polydimethylsiloxane (PDMS), and has microvalves and fluidic channels to transport the sample between nodes for various sample preparation steps.
nontarget biomolecules are washed off, and the bound targets are released then by heating, labeled with fluorescent markers,
and transferred to the optofluidic chip for optical detection. Schmidt noted that the team has not yet been able to test the system starting with raw blood samples.
"We are also working to use the same system for detecting less dangerous pathogens and do the complete analysis here at UC Santa cruz
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