#Scientists grow organic semiconductor crystals vertically for first time Our smartphones, tablets, computers and biosensors all have improved because of the rapidly increasing efficiency of semiconductors.
Since the turn of the 21st century, organic, or carbon-based, semiconductors have emerged as a major area of interest for scientists
because they are inexpensive, plentiful and lightweight, and they can conduct current in ways comparable to inorganic semiconductors,
which are made from metal-oxides or silicon. Now, materials scientists from the California Nanosystems Institute at UCLA have discovered a way to make organic semiconductors more powerful and more efficient.
Their breakthrough was in creating an improved structure for one type of organic semiconductor a building block of a conductive polymer called tetraaniline.
The scientists showed for the first time that tetraaniline crystals could be grown vertically. The advance could eventually lead to vastly improved technology for capturing solar energy.
In fact, it could literally reshape solar cells. Scientists could potentially create ight antennasthin, pole-like devices that could absorb light from all directions,
which would be an improvement over today wide, flat panels that can only absorb light from one surface.
The study, led by Richard Kaner, distinguished professor of chemistry and biochemistry and materials science and engineering, was published recently by the journal ACS Nano.
The UCLA team grew the tetraaniline crystals vertically from a substrate so the crystals stood up like spikes instead of lying flat as they do produced
when using current techniques. They produced the crystals in a solution using a substrate made of graphene,
a nanomaterial consisting of graphite that is extremely thin measuring the thickness of a single atom.
Scientists had grown previously crystals vertically in inorganic semiconducting materials, including silicon, but doing it in organic materials has been more difficult.
Tetraaniline is a desirable material for semiconductors because of its particular electrical and chemical properties, which are determined by the orientation of very small crystals it contains.
Devices such as solar cells and photosensors work better if the crystals grow vertically because vertical crystals can be packed more densely in the semiconductor,
making it more powerful and more efficient at controlling electrical current. hese crystals are analogous to organizing a table covered with scattered pencils into a pencil cup,
said Yue essicawang, a former UCLA doctoral student who now is a postdoctoral scholar at Stanford university
and was the study first author. he vertical orientation can save a great deal of space, and that can mean smaller, more efficient personal electronics in the near future.
Once Kaner and his colleagues found they could guide the tetraaniline solution to grow vertical crystals,
they developed a one-step method for growing highly ordered, vertically aligned crystals for a variety of organic semiconductors using the same graphene substrate. he key was deciphering the interactions between organic semiconductors and graphene in various solvent environments,
Wang said. nce we understood this complex mechanism, growing vertical organic crystals became simple. Kaner said the researchers also discovered another advantage of the graphene substrate. his technique enables us to pattern crystals wherever we want,
he said. ou could make electronic devices from these semiconductor crystals and grow them precisely in intricate patterns required for the device you want, such as thin-film transistors or light-emitting diodes. a
#Medical device Breakthrough: UV LIGHT enabled catheter fixes holes in the heart without invasive surgery Researchers from Boston Children Hospital, the Wyss Institute for Biologically Inspired Engineering at Harvard university,
Harvard John A. Paulson School of engineering and Applied sciences (SEAS) and the Karp Lab at Brigham and Women Hospital have designed jointly a specialized catheter for fixing holes in the heart using a biodegradable adhesive and patch.
As the team reports in Science Translational Medicine, the catheter has been used successfully in animal studies to facilitate hole closure without the need for open heart surgery.
Pedro delnido, MD Chief of Cardiac Surgery at Boston Children and contributing author on the study, says the device represents a radical change in the way these kinds of cardiac defects are repaired. n addition to avoiding open heart surgery,
this method avoids suturing into the heart tissue, because wee just gluing something to it. atheterizations are preferable to open heart surgery
because they don require stopping the heart, putting the patient on bypass, and cutting into the heart.
The Heart Center at Boston Children is committed to pursuing the least invasive methods possible to correct heart defects,
which are among the most common congenital defects. Last winter the unique adhesive patch was published in Science Translational Medicine.
This represented a large step forward in the quest to reduce complications associated with heart defect repair.
While medical devices that remain in the body may be jostled out of place or fail to cover the hole as the body grows,
the patch allows for heart tissue to create its own closure and then dissolves. To truly realize the patch potential,
however, the Boston Children/Wyss/SEAS/Brigham and Women research team sought a way to deliver the patch without open heart surgery.
Their newly designed catheter device utilizes UV LIGHT technology and can be used to place the patch in a beating heart.
The catheter is inserted through a vein in the neck or groin and directed to the defect within the heart.
Once the catheter is in place, the clinician opens two positioning balloons: one around the front end of the catheter, passing through the hole,
and one on the other side of the heart wall. The clinician then deploys the patch and turns on the catheter UV LIGHT.
The light reflects off of the balloon shiny interior and activates the patch adhesive coating.
As the glue cures, pressure from the positioning balloons on either side of the patch help secure it in place.
Finally, both balloons are deflated and the catheter is withdrawn. Over time, normal tissue growth resumes and heart tissue grows over the patch.
The patch itself dissolves when it is needed no longer. his really is a completely new platform for closing wounds or holes anywhere in the body,
says Conor Walsh, Ph d.,Wyss Institute Core Faculty member, Assistant professor of Mechanical and Biomedical engineering AT SEAS, founder of the Harvard Biodesign Lab AT SEAS,
and author on the paper. he device is a minimally invasive way to deliver a patch
and then activate it using UV LIGHT, all within a matter of five minutes and in an atraumatic way that doesn require a separate incision.
EAS/Wyss Institute Ellen Roche, Ph d.,co-first author on the paper along with Boston Children Assunta Fabozzo, M d.,adds that the device is designed to be customizable.
For instance the rate at which the patch biodegrades can be slowed or accelerated depending on how quickly the surrounding tissue grows over it.
Further studies will reveal the appropriate lengths of time for different circumstances. Jeff Karp, Ph d.,a bioengineer at Brigham and Women Hospital and a cofounder of Gecko Biomedical, developed the glue product in his lab at Brigham and Women Hospital.
Gecko Biomedical will be testing the glue product in humans later this year. ur collaboration across hospitals
and institutions to find new and minimally invasive applications for this glue in clinical settings is a great multi-disciplinary example,
Karp said. e are translating our discoveries in the lab into solutions for patients.?The way the glue works in the face of blood is revolutionary.
We don have to stop the heart, says delnido. his will enable a wide range of cardiac procedures in the future. l
#Physicists turn toward heat to study electron spin The quest to control and understand the intrinsic spin of electrons to advance nanoscale electronics is hampered by how hard it is to measure tiny, fast magnetic devices.
Applied physicists at Cornell offer a solution: using heat, instead of light, to measure magnetic systems at short length and time scales.
Researchers led by Greg Fuchs, assistant professor of applied and engineering physics, detail this new way to directly measure magnetic moments and how it may be used to break fundamental limits of spatial resolution that are imposed in purely optical magnetic measurements.
Such a breakthrough, if perfected, could lead to a novel tabletop magnetic measurement technique and new, nanoscale electronic devices based on electrical spin, rather than charge.
Their technique, which they call TRANE (Time-Resolved Anomalous Nernst Effect) microscopy, is detailed in the journal Nature Communications (Sept. 30.)
Why the interest in electron spin? In physics, electron spin is established the well phenomenon of electrons behaving like a quantum version of a spinning top,
and the angular momentum of these little tops pointing por own. An emerging field called spintronics explores the idea of using electron spin to control
and store information using very low power. Technologies like nonvolatile magnetic memory could result with the broad understanding and application of electron spin.
Spintronics, the subject of the 2007 Nobel prize in Physics, is already impacting traditional electronics, which is based on the control of electron charge rather than spin. irect imaging is really hard to do,
Fuchs said. evices are tiny, and moving really fast, at gigahertz frequencies. Wee talking about nanometers and picoseconds.
Scientists have been unable to directly image magnetic motion in nanoscale spintronic devices without hugely expensive X-ray sources at national facilities.
In their own labs, the best they could do was infer magnetic properties from electrical measurements.
graduate student in the field of applied physics. t an exciting area to start looking at
such as fabricating gold antennae to excite thermal excitations confined to nanoscale dimensions o
#Restoring vision with stem cells Researchers have succeed in producing photoreceptors from human embryonic stem cells Age-related macular degeneration (AMRD) could be treated by transplanting photoreceptors produced by the directed differentiation of stem cells,
thanks to findings published today by Professor Gilbert Bernier of the University of Montreal and its affiliated Maisonneuve-Rosemont Hospital.
Professor Gilbert explained. ithin 45 days, the cones that we allowed to grow towards confluence spontaneously formed organised retinal tissue that was 150 microns thick.
The transplanted photoreceptors migrated naturally within the retina of their host. one transplant represents a therapeutic solution for retinal pathologies caused by the degeneration of photoreceptor cells,
offering hope that treatments may be developed for currently non-curable degenerative diseases, like Stargardt disease and ARMD. esearchers have been trying to achieve this kind of trial for years,
he said. hanks to our simple and effective approach, any laboratory in the world will now be able to create masses of photoreceptors.
ARMD is in fact the greatest cause of blindness amongst people over the age of 50
this accelerated aging of the retina affects nearly one in four. People with ARMD gradually lose their perception of colours
write, watch television or even recognize a face. ARMD is due to the degeneration of the macula,
This degeneration is caused by the destruction of the cones and cells in the retinal pigment epithelium (RPE),
and less effective waste accumulates, forming deposits. ifferentiating RPE cells is quite easy. But in order to undertake a complete therapy,
we need neuronal tissue that links all RPE cells to the cones. That is much more complex to develop,
Indeed, bioinformatic analysis led him to predict the existence of a mysterious protein: COCO, a ecombinationalhuman molecule that is normally expressed within photoreceptors during their development.
In 2001, he launched his laboratory at Maisonneuve-Rosemont Hospital and immediately isolated the molecule.
Beyond the clinical applications, Professor Bernier findings could enable the modelling of human retinal degenerative diseases through the use of induced pluripotent stem cells,
offering the possibility of directly testing potential avenues for therapy on the patient own tissues e
lack of link to autism New research finds no evidence that thimerosal-containing vaccines cause negative behaviors or result in neuropathology in infant primates,
according to a study (PDF) published in PNAS, the Proceedings of the National Academy of Sciences.
In the study, infant rhesus macaques received several pediatric vaccines containing thimerosal, a mercury-based preservative,
Other animals received just the measles-mumps-rubella (MMR) vaccine, which does not contain thimerosal,
or an expanded vaccine schedule similar to that recommended for U s. infants today. Control animals received a saline injection.
Regardless of vaccination status all animals developed normal social behaviors; the administration of vaccines to rhesus macaques did not result in neuropathological abnormalities or aberrant behaviors such as those often observed in autism.
Cellular analysis of the cerebellum, amygdala and hippocampus three brain regions known to be altered in autism was vaccinated similar in
and unvaccinated animals. his comprehensive study included many physiological measures and behavioral measures. Fundamentally the vaccines had no ill effects,
said Gene Sackett, UW professor emeritus of psychology and director of the lab work at the Washington National Primate Research center. o the extent that macaques mirror human physiology,
I think this bears out what most people have known: These vaccines are safe. n
#New technology enables people to take own blood samples at home A world-first prototype for taking accurate blood samples at home has been developed by a Tasmanian-led research partnership.
The hemapen is a prototype blood collection and storage device which enables users to take blood samples at home in a safe and portable application.
It allows people to collect an uncontaminated and precise volume of their own blood from their fingertips with the click of a button,
as the device design is based on a retractable pen. The technology also aims to address the limitations of dried blood sampling
a procedure which is used often in newborn screening and requires correct amount and placement of blood samples usually undertaken by health professionals.
The hemapen was developed by ASTECH; the $5. 2 million Australian Research Council Training Centre for Portable Analytical Separation Technologies based at the University of Tasmania,
and in partnership with Trajan Scientific and Medical and the Federal government. ASTECH Training Centre Researcher Professor Michael Breadmore said the design
and development of the hemapen is a world-first and promises to save time and money for the millions of people having to undertake blood sampling. p until now,
people who regularly require blood tests have to access the services of health professionals, Professor Breadmore said. his is often time-consuming and costly for both the individual and health care systems.
The device is designed by ASTECH Postdoctoral Research Fellow Dr Florian Lapierre who has undertaken industry placement at Trajan where he researched
and developed the prototype. he idea behind the device design is literally based on integrating microfluidic technology into a retractable pen,
Dr Lapierre said. t functional, intuitive and stores a precise volume of a sample safely and securely, providing greater user-experience and superior sample in a ready-to-use analytical format.
Professor Breadmore said the Centre was aiming to bridge the gap between research and product development through the partnership with Trajan. he hemapen is an example of ASTECH core foundations;
developing new portable technology for point-of-sample analysis by putting research into action through research and industry partnerships,
he said. Trajan Chief executive officer Stephen Tomisich said Trajan is driven by a passion to develop technologies that will impact human wellbeing. hilst this first iteration of the hemapen provides a DBS format ready for Liquid Chromatography-Mass Spectrometry (LC-MS) analysis,
we are now working on future versions with various interfaces, potentially with inbuilt sensing technology, he said s
#New Test Predicts Teensfuture Risk of Heart disease Risk for cardiovascular disease, currently running rampant in the United states,
can now be predicted for adolescents, thanks to a new diagnostic test developed by a University of Virginia Children Hospital pediatrician and his collaborators.
The test accounts for many risk factors for the deadly disease and has the potential to be adapted by physicians nationwide to assess teenagersfuture risk
and encourage the healthy behaviors that could save their lives. Approximately 610,000 people die from heart disease every year in the United states oughly one of every four deaths
according to the Centers for Disease Control. Cardiovascular disease has predominantly modifiable risk factors, meaning that the disease is entirely preventable.
These risk factors include high blood pressure, high cholesterol, obesity, physical inactivity, diabetes, unhealthy diets and smoking.
The only risk factor unable to be changed is genetic predisposition. A team led by Dr. Mark Deboer of the U. Va. Department of Pediatrics
and Matthew Gurka of West virginia University School of Public health developed the new diagnostic test. The test relies on an evaluation of metabolic syndrome,
a conglomeration of conditions including increased blood pressure, high levels of blood sugar, excessive body fat around the abdomen and waist,
and abnormal cholesterol levels that together increase the risk of cardiovascular disease. It takes into account variables specific both to race
and gender. he way that we normally diagnose metabolic syndrome appears to have some racial discrepancies,
where African-american individuals are diagnosed not with metabolic syndrome at a very high rate and yet they are at very high risk for developing type 2 diabetes and cardiovascular disease,
so Dr. Gurka and I formulated a metabolic syndrome severity score that is specific to sex and ethnicity,
Deboer said. In creating the test, Deboer and Gurka examined metabolic severity scores from children in the 1970s that assessed body mass index, systolic blood pressure, fasting triglycerides, HDL cholesterol (the so-called oodcholesterol) and fasting glucose.
The children were followed up as recently as 2014, at an average age of 49.6 years. he current study was targeted at using that metabolic syndrome severity score on data from individuals who were children in the 0s to see
if it correlated with their risk on developing cardiovascular disease and type 2 diabetes later in life,
and we found that there was a high correlation between the metabolic severity score for those children and for their later development of cardiovascular disease and diabetes,
Deboer explained. The test is innovative in that it is able to assess changes in metabolic syndrome severity in a person over time
and creates a specific number predicting risk. Previous diagnostic tests have been merely positive or negative, stating that a person either has
or does not have metabolic syndrome, but the new test is able to create a scale,
delineating the precise degree to which a youth is at risk. e are hopeful that this score can be used to assess the baseline risk for adolescents regarding metabolic syndrome
and their risk for future disease and use it as a motivator for individuals to try to change their risk
so that they may have a healthier diet, engage in more physical activity or get medication to reduce their metabolic syndrome severity and their future risk for disease,
Deboer said. The research has been described in articles in the Journal of the American College of Cardiology and the journal Diabetologia.
The research team included U. Va. Deboer, West virginia Gurka and Jessica Woo and John A. Morrison, both of Cincinnati Children Hospital.
There is also a website available for calculating a child metabolic syndrome severity score using clinical measures e
#New microscopy technology augments surgeon view for greater accuracy Researchers at the University of Arizona (UA) have developed a prototype of a new microscope technology that could help surgeons work with a greater degree
of accuracy. The new technology, call augmented microscopy, overlays images depicting diagnostic information such as blood flow and cancerous tissue over real images of blood vessels and other tissues
and structures being viewed in the microscope. A report on the work by Jeffrey Watson and co-authors from the UA departments of Biomedical engineering
and Surgery was published today in the Journal of Biomedical Optics, published by SPIE, the international society for optics and photonics.
Surgical microscopes are specialized highly stereomicroscopes installed on articulated mounts and provide a long working distance and functional enhancements,
and are used widely in certain delicate operations, notably neurosurgery. Within the last decade, surgical microscopes have been combined with near-infrared (NIR) fluorescence imaging, in
which contrast agents are injected into tissue and their fluorescence detected in NIR scans. The scans may reveal patterns of blood flow,
or differentiate cancerous from normal tissue. But there are limitations. For example, some microscopes used in complex vascular surgeries switch between two different views:
the fully optical bright-field (real) view and the computer-processed projection of NIR fluorescence.
The NIR image is two-dimensional, and on its own lacks the spatial cues that would help the surgeon identify anatomical points of reference.
So the surgeon must visualize how the fluorescence in the NIR image lines up with the respective anatomical structures shown in the bright-field view.
The UA researchersarticle, ugmented microscopy: Real-time overlay of bright-field and near-infrared fluorescence imagesdescribes their prototype of an augmented stereomicroscope that presents a simultaneous view of real objects in the surgical field and computer-processed images
superimposed in real time. urgeons want to see the molecular signals with their eyes, so that they can feel confident about
what is there said journal associate editor Brian Pogue of Dartmouth College. oo often, what they see is a report of the signals depicted in false color on a monitor.
By displaying information through the surgical scope itself, the surgeon then sees the information with his or her own eyes.
Pogue said he sees the work being important in advancing the translation of research into clinical practice. here are very few papers on this idea of augmenting the surgical field of view that the surgeon sees,
yet this is a high-interest topic, he said. his article presents a very practical idea and innovative implementation
which is well done technically. The prototype offers advantages over earlier versions of augmented microscopes. By utilizing the optical path of the stereomicroscope,
it maintains full three-dimensional stereoscopic vision, which is lost in fully digital display systems. It also retains the imaging environment familiar to surgeons,
including key features of surgical microscopes such as real-time magnification and focus adjustments, camera mounting, and multiuser access.
One possible application for this augmented microscope is laser surgery. In the past, surgeons could not see the laser beam through the standard stereomicroscope, nor anatomical details in the NIR images.
The researchers also suggest that this technology will be useful in the surgical treatment of brain tumors.
Surgeons aggressively removing a tumor run the risk of damaging normal brain tissue and impairing the patient brain functions;
on the other hand, incomplete removal of a tumor results in immediate relapse in 90%of patients. Being able to simultaneously see the surgical field
and the contrast agent identifying cancerous tissue within the augmented microscope may allow surgeons to remove these challenging tumors more accurately
#Medical diagnosis: Will brain palpation soon be possible? If there is one technique used by the physician to explore the human body during every medical examination
in order to make a diagnosis or prescribe further tests, it is palpation. By its nature, however, the brain cannot be palpated without using a highly invasive procedure (craniotomy,
or opening the skull), which is limited to rare cases. By drawing on seismology, Inserm researchers led by Stéfan Catheline (Inserm Unit 1032,
herapeutic Applications of Ultrasound have developed just a noninvasive brain imaging method using MRI that provides the same information as physical palpation.
Ultimately, it could be used in the early diagnosis of brain tumours or Alzheimer disease. This work is published in PNAS.
Many diseases involve structural changes in tissues which are reflected in a change in their mechanical properties, such as elasticity.
Using the sensitivity of their hands, and their detailed knowledge of the body, physicians, through an examination known as palpation, can assess the size and stiffness of a tumour, the presence of inflamed lymph nodes,
or the size and position of the foetus in a pregnant woman, to mention a few examples.
This palpation has been supplemented or replaced by modern techniques that give the physician an indication of the elasticity of a biological tissue.
They are based on the generation and detection of waves that propagate through the body at varying speeds depending on the stiffness of the organs (the stiffer the tissue,
the slower the wave propagation, and vice versa. However, this method cannot be applied to the brain,
something that greatly complicates the work of neurosurgeons. On the other hand, the brain is the seat of natural vibrations created by the blood pulsating in the arteries and the circulating cerebrospinal fluid.
There remained a significant unprecedented challenge: how to capture this complex field of natural shear waves,
and represent it on a computer screen. In this article, Inserm researchers, using MRI, have succeeded in detecting natural shear waves in the brain using computational techniques borrowed from seismologists
says Stéfan Catheline, Inserm Research director and main author of this work. lzheimer disease, epilepsy, multiple sclerosis and hydrocephalus involve changes in the stiffness of the brain tissues.
This new technique allows their detection, and could be used to avoid brain biopsies. This method for palpating the brain could have other areas of application,
such as for analysing the development of neurodegenerative processes, the impact of a lesion from a trauma or tumour, response to treatment, etc e
#Discovery about new battery overturns decades of false assumptions New findings at Oregon State university have overturned a scientific dogma that stood for decades,
by showing that potassium can work with graphite in a potassium-ion battery a discovery that could pose a challenge and sustainable alternative to the widely-used lithium-ion battery.
Lithium-ion batteries are ubiquitous in devices all over the world, ranging from cell phones to laptop computers and electric cars.
But there may soon be a new type of battery based on materials that are far more abundant and less costly.
A potassium-ion battery has been shown to be possible. And the last time this possibility was explored was
when Herbert hoover was president, the Great depression was in full swing and the Charles Lindbergh baby kidnapping was the big news story of the year 1932. or decades,
people have assumed that potassium couldn work with graphite or other bulk carbon anodes in a battery, said Xiulei (David) Ji,
the lead author of the study and an assistant professor of chemistry in the College of Science at Oregon State university. hat assumption is said incorrect,
Ji. t really shocking that no one ever reported on this issue for 83 years. he Journal of the American Chemical Society published the findings from this discovery,
which was supported by the U s. Department of energy and done in collaboration with OSU researchers Zelang Jian and Wei Luo.
because they open some new alternatives to batteries that can work with well-established and inexpensive graphite as the anode,
or high-energy reservoir of electrons. Lithium can do that, as the charge carrier whose ions migrate into the graphite
and create an electrical current. Aside from its ability to work well with a carbon anode, however
lithium is quite rare, found in only 0. 0017 percent, by weight, of the Earth crust.
The new findings show that it can work effectively with graphite or soft carbon in the anode of an electrochemical battery.
Right now, batteries based on this approach don have performance that equals those of lithium-ion batteries,
he said. t safe to say that the energy density of a potassium-ion battery may never exceed that of lithium-ion batteries,
and be ready to take the advantage of the existing manufacturing processes of carbon anode materials. lectrical energy storage in batteries is essential not only for consumer products such as cell phones and computers,
but also in transportation industry power backup, micro grid storage, and for the wider use of renewable energy. OSU officials say they are seeking support for further research
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