#New, Ultrathin Optical devices Shape Light in Exotic Ways Researchers have developed innovative flat, optical lenses as part of a collaboration between NASA Jet propulsion laboratory and the California Institute of technology, both in Pasadena, California.
Instead, silicon nanopillars are arranged precisely into a honeycomb pattern to create a etasurfacethat can control the paths and properties of passing light waves.
Applications of these devices include advanced microscopes, displays, sensors, and cameras that can be mass-produced using the same techniques used to manufacture computer microchips. hese flat lenses will help us to make more compact and robust imaging assemblies,
said Mahmood Bagheri, a microdevices engineer at JPL and co-author of a new Nature Nanotechnology study describing the devices. urrently,
optical systems are made one component at a time, and the components are assembled often manually, said Andrei Faraon, an assistant professor of applied physics and materials science at Caltech,
and the study principal investigator. ut this new technology is very similar to the one used to print semiconductor chips onto silicon wafers,
so you could conceivably manufacture millions of systems such as microscopes or cameras at a time. een under a scanning electron microscope,
the new metasurfaces that the researchers created resemble a cut forest where only the stumps remain.
Each silicon stump, or pillar has an elliptical cross section, and by carefully varying the diameters of each pillar
Manipulating the polarization of light is essential for the operation of advanced microscopes, cameras and displays;
the control of polarization also enables simple gadgets such as 3-D glasses and polarized sunglasses. f you think of a modern microscope,
Semiconductor lasers typically emit into elliptical beams that are really hard to work with and the new metasurface optical components could replace expensive optical systems used to circularize the beams.
UQ researchers Mr Paul Miller and Associate professor Derek Arnold say most people don even know they have a blind spot in their vision,
though you can shrink your blind spot by up to 10 per cent with training, even though there will always be a hole in your visual field. he neuroscientists at UQ School of Psychology may have opened the way to new treatments for the developed world leading cause of blindness,
age-related macular degeneration. ou can only enhance sensitivity at the blind spot periphery, but this has proved sufficient to bring about a 10 per cent reduction in functional blindness,
Mr Miller said. The research involved training 10 people for 20 consecutive days on a direction-discrimination task.
Participants were presented with a drifting waveform in a ring centred around the blind spot in one of their eyes. t the end of the training
there were improvements in the ability to correctly judge both the direction and the colour of the waveform,
suggesting that the improvement wasn simply a matter of practising the task. e did not confidently expect to see much reduction in functional blindness,
as you can never develop photosensitivity within the blind spot itself. f training can reduce the physiological blind spot,
it might prove similarly effective in other cases of blindness or be used to assist developing technologies,
such as the bionic eye or retinal stem cell therapy. c
#DNA-Guided 3-D Printing of Human Tissue Is unveiled A UCSF-led team has developed a technique to build tiny models of human tissues, called organoids,
more precisely than ever before using a process that turns human cells into a biological equivalent of LEGO bricks.
These mini-tissues in a dish can be used to study how particular structural features of tissue affect normal growth
or go awry in cancer. They could be used for therapeutic drug screening and to help teach researchers how to grow whole human organs.
The new technique called DNA Programmed Assembly of Cells (DPAC) and reported in the journal Nature Methods on Aug 31 allows researchers to create arrays of thousands of custom-designed organoids,
the paper senior author and an associate professor of pharmaceutical chemistry at UCSF. e can take any cell type we want
we could be taking samples of different components of a cancer patient mammary gland and building a model of their tissue to use as a personalized drug screening platform.
Another is to use the rules of tissue growth we learn with these models to one day grow complete organs. ur bodies are made of more than 10 trillion cells of hundreds of different kinds, each
keeping the whole biological machine running smoothly. But in diseases such as breast cancer, the breakdown of this order has been associated with the rapid growth
and spread of tumors. ells aren lonely little automatons, Gartner said. hey communicate through networks to make group decisions.
As in any complex organization, you really need to get the group structure right to be failed successful,
it sets the stage for cancer. ut studying how the cells of complex tissues like the mammary gland self-organize,
and break down in disease has been a challenge to researchers. The living organism is often too complex to identify the specific causes of a particular cellular behavior.
and manipulate, said Michael Todhunter, Phd, who led the new study with Noel Jee, Phd,
when both were graduate students in the Gartner research group. t lets us ask questions about complex human tissues without needing to do experiments on humans. o specify the 3-D structure of their organoids,
but also to experiment with specifically adding in a single cell with a known cancer mutation to different parts of the organoid to observe its effects.
or more cells expressing low levels of the cancer gene Rasg12v affected the cells around them.
or structural changes in mammary glands can lead to the breakdown of tissue architecture associated with tumors that metastasize,
and kidney and neural circuits using larger-scale techniques. uilding functional models of the complex cellular networks such as those found in the brain is probably one of the highest challenges you could aspire to,
#Mouth Guard Monitors Health Markers, Transmits Information Wirelessly to Smart Phone Engineers at the University of California,
San diego, have developed a mouth guard that can monitor health markers, such as lactate, cortisol and uric acid,
in saliva and transmit the information wirelessly to a smart phone, laptop or tablet. The technology,
or stress levels in soldiers and pilots. In this study, engineers focused on uric acid, which is a marker related to diabetes and to gout.
Currently the only way to monitor the levels of uric acid in a patient is to draw blood.
The team, led by nanoengineering professor Joseph Wang and electrical engineering professor Patrick Mercier, both from the University of California,
and non-invasively saliva biomarkers holds considerable promise for many biomedical and fitness applications, said Wang.
Testing the sensors In this study, researchers showed that the mouth guard sensor could offer an easy and reliable way to monitor uric acid levels.
The mouth guard has been tested with human saliva but hasn been tested in a person mouth. Researchers collected saliva samples from healthy volunteers and spread them on the sensor,
which produced readings in a normal range. Next, they collected saliva from a patient who suffers from hyperuricemia,
a condition characterized by an excess of uric acid in the blood. The sensor detected more than four times as much uric acid in the patient saliva than in the healthy volunteers.
The patient also took Allopurinol, which had been prescribed by a physician to treat their condition. Researchers were able to document a drop in the levels of uric acid over four
In the past, the patient would have needed blood draws to monitor levels and relied instead on symptoms to start
Fabrication and design Wang team created a screen-printed sensor using silver, Prussian blue ink and uricase,
and contains many different biomarkers, researchers needed to make sure that the sensors only reacted with the uric acid.
Nanoengineers set up the chemical equivalent of a two-step authentication system. The first step is a series of chemical keyholes,
which ensures that only the smallest biochemicals get inside the sensor. The second step is a layer of uricase trapped in polymers,
which reacts selectively with uric acid. The reaction between acid and enzyme generates hydrogen peroxide which is detected by the Prussian blue ink.
That information is transmitted then to an electronic board as electrical signals via metallic strips that are part of the sensor.
The electronic board, developed by Mercier team, uses small chips that sense the output of the sensors, digitizes this output
and then wirelessly transmits data to a smart phone, tablet or laptop. The entire electronic board occupies an area slightly larger than a U s. penny.
Next steps The next step is embed to all the electronics inside the mouth guard so that it can actually be worn.
Researchers also will have to test the materials used for the sensors and electronics to make sure that they are indeed completely biocompatible.
The next iteration of the mouth guard is about a year out, Mercier estimates. ll the components are said there,
he. t just a matter of refining the device and working on its stability. Wang and Mercier lead the Center for Wearable Sensors at UC San diego,
which has made a series of breakthroughs in the field, including temporary tattoos that monitor glucose, ultra-miniaturized energy-processing chips
and pens filled with high-tech inks for Do it yourself chemical sensors. C San diego has become a leader in the field of wearable sensors,
said Mercier e
#Study finds dramatic increase in concurrent droughts, heat waves Droughts and heat waves are happening simultaneously with much greater frequency than in the past, according to research by climate experts at the University of California, Irvine.
Their findings appear in Proceedings of the National Academy of Sciences. A team from UCI Center for Hydrometeorology & Remote Sensing examined data gathered from ground sensors and gauges during a 50-year period beginning in 1960.
Applying a statistical analysis to the half-century data set, the researchers observed a significant increase in concurrent droughts
and heat waves. eat waves can kill people and crops while worsening air quality, and droughts exacerbate those serious impacts,
said senior author Amir Aghakouchak, assistant professor of civil & environmental engineering. ith these two extremes happening at the same time,
the threat is far more significant. For the purposes of the study, heat waves were defined as three to seven consecutive hot days, with temperatures in the 90th percentile of the historical record.
Droughts were described as extended periods during which precipitation was 20 percent or less of the norm,
as measured by the Standardized Precipitation Index. While the researchers did not look into human-caused global climate change in this study
Agha Kouchak said, an overall increase in the mean temperature worldwide is raising the probability of heat waves.
He cited the recent record-breaking high in Iran: NASA SATELLITES and National Oceanic & Atmospheric Administration data sets documented a 115-Degree fahrenheit surface temperature with a omfort indexof 165 degrees on July 31 in the city of Bandar-e Mahshahr.
The standard approach to squeezing light involves firing an intense laser beam at a material, usually a nonlinear crystal,
or photons, using an artificially constructed atom, known as a semiconductor quantum dot. Thanks to the enhanced optical properties of this system and the technique used to make the measurements,
Professor Mete Atature, from the Cavendish Laboratory, Department of physics, and a Fellow of St john College at the University of Cambridge,
led the research. He said: t one of those cases of a fundamental question that theorists came up with,
it seems smooth and flat, but we know that if you really zoom in to a superfine level,
In the Cambridge experiment, the researchers achieved this by shining a faint laser beam on to their artificial atom, the quantum dot.
This excited the quantum dot and led to the emission of a stream of individual photons.
At its core, however, is a rule known as Heisenberg uncertainty principle. This states that in any situation in which a particle has linked two properties,
By scattering faint laser light from the quantum dot, the noise of part of the electromagnetic field was reduced to an extremely precise and low level
This was done at the expense of making other parts of the electromagnetic field less measurable, meaning that it became possible to create a level of noise that was lower-than-nothing, in keeping with Heisenberg uncertainty principle,
which fluctuations in the electromagnetic field could be measured on a graph creates a shape where the uncertainty of one part has been reduced,
#An engineered surface unsticks sticky water droplets The leaves of the lotus flower, and other natural surfaces that repel water
assistant professor of mechanical engineering and a faculty member in the Penn State Materials Research Institute. ur surfaces combine the unique surface architectures of lotus leaves
We have demonstrated for the first time experimentally that liquid droplets can be highly mobile when in the Wenzel state.
said Birgitt Boschitsch Stogin, graduate student in Wong group and coauthor of lippery Wenzel State, published in the online edition of ACS Nano. roplets on conventional rough surfaces are mobile in the Cassie state
Our idea is to solve these problems by enabling Wenzel state droplets to be said mobile
postdoctoral scholar in Wong group and the lead author on the paper. In the last decade, tremendous efforts have been devoted to designing rough surfaces that prevent the Cassie-to-Wenzel wetting transition.
In order to make Wenzel state droplets mobile, the researchers etched micrometer scale pillars into a silicon surface using photolithography and deep reactive-ion etching,
and then created nanoscale textures on the pillars by wet etching. They then infused the nanotextures with a layer of lubricant that completely coated the nanostructures,
resulting in greatly reduced pinning of the droplets. The nanostructures also greatly enhanced lubricant retention compared to the microstructured surface alone.
The same design principle can be extended easily to other materials beyond silicon, such as metals glass ceramics and plastics.
The authors believe this work will open the search for a new, unified model of wetting physics that explains wetting phenomena on rough surfaces e
#Team develops quick way to determine bacteria antibiotic resistance Bacteria ability to become resistant to antibiotics is a growing issue in health care:
Resistant strains result in prolonged illnesses and higher mortality rates. One way to combat this is to determine bacteria antibiotic resistance in a given patient,
but that often takes days and time is crucial in treatment. ASU scientists have developed a technique that can sort antibiotic-resistant from usceptiblebacteria,
Staphylococcus epidermis is increasingly emerging as a cause of multi-resistant hospital-acquired infections. The ability to quickly judge whether a bacteria is resistant to antibiotics could make a major difference in a patient's treatment.
Shannon Hilton and Paul Jones Staphylococcus epidermis is increasingly emerging as a cause of multi-resistant hospital-acquired infections.
Shannon Hilton and Paul Jones The microfluidic technology, developed in the lab of professor Mark Hayes in the Department of chemistry and Biochemistry at Arizona State university, uses microscale electric field gradients, acting on extremely small samples,
Armies of bacteria sneak into our bodies the moment we are born, uninvited but necessary guests.
Two members of Hayesteam graduate students Paul V. Jones and Shannon (Huey) Hilton work in the lab. They have separated extremely similar bacteria:
Mark Hayes Two members of Hayesteam graduate students Paul V. Jones and Shannon (Huey) Hilton work in the lab. They have separated extremely similar bacteria:
Mark Hayes National summary data from the Centers for Disease Control and Prevention indicate that each year in the United states,
at least 2 million people acquire serious infections with antibiotic-resistant strains of bacteria. At least 23,000 people die as a direct result of these infections,
and many more die from related complications. It is not just humans that are threatened by this growing adaptation.
Some of the most notorious antibiotic-resistant strains and species belong to the genus Staphylococcus. They are classified typically as pathogenic or non-pathogenic based on production of the enzyme coagulase.
however, Staphylococcus epidermidis has emerged increasingly as a cause of multi-resistant hospital-acquired infections. Immunocompromised patients
indwelling medical devices, and surgically implanted prostheses provide suitable environments for Staphylococcus epidermidis to propagate and form biofilms.
This is where the project began, as a collaboration with orthopedic surgeon Dr. Alex Mclaren and his team member and bioengineer Dr. Ryan Mclemore of Banner Good samaritan Medical center, Phoenix,
along with Dr. Mark Spangehl of the Mayo Clinic College of Medicine, Arizona. By most metrics the antibiotic-resistant and susceptible strains of Staphylococcus epidermidis are phenotypically identical,
and thus present a major challenge to traditional analytical separation techniques. This is where the ASU technology is finding its place.
Current clinical approaches to determination of antibiotic resistance often require two or more days to obtain results.
Scientists in the Hayes group at ASU Department of chemistry and Biochemistry soon to become the School of Molecular Sciences are enabling a handheld,
battery-operated device that might deliver answers in minutes, instead of days. Identification takes place within a microscopically small channel in a chip made from glass and silicone polymer.
The microchannel features sawtooth shapes that allow researchers to sort and concentrate microbes based on their unique electrical properties.
The phenomenon that makes this work is called dielectrophoresis, which involves an applied voltage that exerts force upon the bacteria.
Hayesteam, including graduate students Paul V. Jones and Shannon (Huey) Hilton, has separated extremely similar bacteria Gentamicin (antibiotic) resistant and susceptible bacteria.
and the doctor is getting the right answer right away. By advancing a fundamental area of science,
Hayes said. nd it turns out that we have a core mechanism that could be integrated with smartphones
The geometric features of the channel shape the electric field creating regions of different intensity. This field creates the dielectrophoretic force that allows some cells to pass,
This separation has significant potential implications for health care, as rapid and early detection will significantly improve therapeutic outcomes.
The current results establish a foundation for biophysical separations as a direct diagnostic tool, potentially improving nearly every figure of merit for diagnostics and antibiotic stewardship o
#acterial Litmus Testprovides Inexpensive Measurement of Micronutrients A bacterium engineered to produce different pigments in response to varying levels of a micronutrient in blood samples could give health officials an inexpensive way to detect nutritional
an assistant professor in the School of Chemical & Biomolecular engineering at the Georgia Institute of technology. he information we can provide could one day help nutritional epidemiologists
The research was supported by the Bill and Melinda Gates Foundation the National Science Foundation and the National institutes of health.
a bacterium that is frequently used in genetic engineering. E coli has a transcriptional system that responds to the level of zinc in its environment,
and the researchers have tuned it to trigger the production of purple, red and orange pigments.
Genetic machinery for the production of those pigments was taken from other biological sources and introduced into the E coli.
In practice, health professionals in the field would obtain blood samples from persons suspected of having a zinc deficiency.
The blood samples would be spun on a simple mechanical device resembling an eggbeater to separate the plasma from the blood cells.
The plasma would then be placed into a test tube or other container with a pellet containing the modified E coli.
Once mixed with the plasma, the E coli would multiply, producing the color corresponding to the level of zinc in the blood plasma.
Purple would correspond to dangerously low levels, while red would indicate borderline levels, and orange normal levels.
or other electronic equipment. he process for the color change would take about 24 hours from
when the plasma sample is added, though we are hoping to accelerate that, said Styczynski. The testing wouldn be done to identify individuals in need of treatment,
or perhaps locations suffering natural disasters, Styczynski explained. hese deficiencies aren treated on an individual level, but are considered on a population level
and pigment-producing genetic machinery can be introduced. ltimately, we hope to be able to test for a whole suite of nutrients in a reasonably short period of time
As part of their research, Styczynski and graduate research assistants Daniel Watstein and Monica Mcnerney engineered pigment producing machinery into the E coli.
lycopene and beta-carotene, are produced by genes taken from Pantoea anantis, a plant pathogen. The purple color, violacein, came from a soil bacterium.
Genes for producing the pigments were placed onto a plasmid and introduced into the bacterium. The researchers used two zinc-sensing proteins within the E coli
which those proteins could turn the pigment producing genes on and off. This approach made the zinc-sensing proteins responsive to levels of zinc close to that expected to be found in blood plasma,
One of the challenges was to avoid producing amounts of pigment that might be toxic to the bacterium
while producing pigment quickly enough to be visible to the naked eye. And because the orange and red pigments are generated in the same metabolic pathway,
the researchers needed to establish ways to produce only one or the other at a time a challenge that their work shows can be addressed feasibly,
though they are still working to fine-tune the implementation. Styczynski believes this system is designed the first to measure blood micronutrients using bacteria without requiring diagnostic equipment.
Revealed by a brand new lectron camera, one of the world speediest, this unprecedented level of detail could guide researchers in the development of efficient solar cells, fast and flexible electronics and high-performance chemical catalysts.
The electrons of the probe pulse scatter off the monolayer atoms (blue and yellow spheres)
and form a scattering pattern on the detector a signal the team used to determine the monolayer structure.
could take materials science to a whole new level. It was made possible with SLAC instrument for ultrafast electron diffraction (UED),
SLAC Director Chi-Chang Kao said, ogether with complementary data from SLAC X-ray laser Linac Coherent light Source,
UED creates unprecedented opportunities for ultrafast science in a broad range of disciplines, from materials science to chemistry to the biosciences.
LCLS is a DOE Office of Science User Facility. This animation explains how researchers use high-energy electrons at SLAC to study faster-than-ever motions of atoms and molecules relevant to important materials properties and chemical processes.
Extraordinary Material Properties in Two Dimensions Monolayers or 2-D materials, contain just a single layer of molecules.
In this form they can take on new and exciting properties such as superior mechanical strength and an extraordinary ability to conduct electricity and heat.
But how do these monolayers acquire their unique characteristics? Until now, researchers only had limited a view of the underlying mechanisms. he functionality of 2-D materials critically depends on how their atoms move,
said SLAC and Stanford researcher Aaron Lindenberg, who led the research team. owever, no one has ever been able to study these motions on the atomic level and in real time before.
Understanding these dynamic ripples could provide crucial clues for the development of next-generation solar cells, electronics and catalysts.
For example, the monolayer form is normally an insulator, but when stretched, it can become electrically conductive.
flexible electronics and to encode information in data storage devices. Thin films of Mos2 are also under study as possible catalysts that facilitate chemical reactions.
In addition they capture light very efficiently and could be used in future solar cells. Because of this strong interaction with light, researchers also think they may be able to manipulate the material properties with light pulses. o engineer future devices,
control them with light and create new properties through systematic modifications, we first need to understand the structural transformations of monolayers on the atomic level,
said Stanford researcher Ehren Mannebach, the study lead author. Previous analyses showed that single layers of molybdenum disulfide have wrinkled a surface.
Researchers at SLAC placed their monolayer samples which were prepared by Linyou Cao group at North carolina State university, into a beam of very energetic electrons.
and produce a signal on a detector that scientists use to determine where atoms are located in the monolayer.
In reality, the monolayer is wrinkled as shown in this room-temperature simulation. Bottom: If a laser pulse heats the monolayer up,
it sends ripples through the layer. These wrinkles, which researchers have observed now for the first time, have large amplitudes
these data show how the light pulses generate wrinkles that have large amplitudes more than 15 percent of the layer thickness
Once scientists better understand monolayers of different materials, they could begin putting them together and engineer mixed materials with completely new optical, mechanical, electronic and chemical properties t
#Brain cells get tweaked n the goresearchers from the MRC Centre for Developmental Neurobiology (MRC CDN) at the Institute of Psychiatry, Psychology & Neuroscience (Ioppn),
King College London, have discovered a new molecular witchthat controls the properties of neurons in response to changes in the activity of their neural network. The findings,
and could have implications that go far beyond basic neuroscience from informing education policy to developing new therapies for neurological disorders such as epilepsy.
Computers are used often as a metaphor for the brain with logic boards and microprocessors representing neural circuits and neurons, respectively.
While this analogy has served neuroscience well in the past, it is far from correct, according to the researchers from King.
and in a way not achieved by computers. Researchers from the MRC CDN, led by Professor Oscar Marín,
have shed light on this problem by discovering that some neurons in the cerebral cortex can adapt their properties in response to changes in network activity such as those observed during learning of a motor task.
a transcription factor a protein able to influence gene expression known as Er81. Fast-spiking interneurons are part of a general class of neurons
and the constraints that disease and ageing impose to this multi-modal plasticity has important implications that go beyond fundamental neuroscience, from education policies to brain repair.
Professor Oscar Marín last author from the MRC CDN, said: ur study demonstrates the tremendous plasticity of the brain,
and how this relates to fundamental processes such as learning. Understanding the mechanisms that regulate this plasticity,
when we age, has enormous implications that go beyond fundamental neuroscience, from informing education policies to developing new therapies for neurological disorders such as epilepsy
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