#Next-generation perovskite solar cells made stable by metal oxide andwichucla professor Yang Yang, member of the California Nanosystems Institute, is renowned a world innovator of solar cell technology
whose team in recent years has developed next-generation solar cells constructed of perovskite, which has remarkable efficiency converting sunlight to electricity.
Despite this success, the delicate nature of perovskite a very light, flexible, organic-inorganic hybrid material stalled further development toward its commercialized use.
When exposed to air, perovskite cells broke down and disintegrated within a few hours to few days.
The cells deteriorated even faster when also exposed to moisture, mainly due to the hydroscopic nature of the perovskite.
Now Yang team has conquered the primary difficulty of perovskite by protecting it between two layers of metal oxide.
This is a significant advance toward stabilizing perovskite solar cells. Their new cell construction extends the cell effective life in air by more than 10 times, with only a marginal loss of efficiency converting sunlight to electricity.
The study was published online in the journal Nature Nanotechnology. Postdoctoral scholar Jingbi You and graduate student Lei Meng from the Yang Lab were the lead authors on the paper. here has been much optimism about perovskite solar cell technology
Meng said. In less than two years, the Yang team has advanced perovskite solar cell efficiency from less than 1 percent to close to 20 percent. ut its short lifespan was a limiting factor we have been trying to improve on since developing perovskite cells with high efficiency.
Yang, who holds the Carol and Lawrence E. Tannas, Jr. Endowed Chair in Engineering at UCLA, said there are several factors that lead to quick deterioration in normally layered perovskite solar cells.
The most significant, Yang said, was that the widely used top organic buffer layer has poor stability
and can effectively protect the perovskite layer from moisture in the air, speeding cell degradation. The buffer layers are important to cell construction
because electricity generated by the cell is extracted through them. Meng said that in this study the team replaced those organic layers with metal oxide layers that sandwich the perovskite layer,
protecting it from moisture. The difference was dramatic. The metal oxide cells lasted 60 days in open-air storage at room temperature
retaining 90 percent of their original solar conversion efficiency. ith this technique perfected we have enhanced significantly the stability.
The next step for the Yang team is to make the metal oxide layers more condensed for better efficiency and seal the solar cell for even longer life with no loss of efficiency.
Yang expects that this process can be scaled up to large production now that the main perovskite problem has been solved p
#Team describes rapid, sensitive test for HIV mutations Tests that can distinguish whether HIV-positive people are infected with a drug-resistant strain
or a non-resistant strain allow patients to get the most effective treatment as quickly as possible.
In the edition of the Journal of Molecular Diagnostics, a team of Brown University researchers describes a new method that works faster and more sensitively in lab testing than the current standard technologies.
The main advance enabling that improved performance is that the system operates directly on the virusmore readily available RNA rather than requiring extra
if a mutation is present and then make many copies of those combined probes (amplification) for detection.
and quantitative PCR (polymerase chain reaction) amplification into a single system, said Anubhav Tripathi, professor of engineering at Brown and corresponding author on the paper. ach HIV contains about 10,000 nucleotides,
or building blocks, in its genetic material, and a drop of blood from a patient with resistant HIV can contain thousands to millions of copies of HIV.
To find that one virus out of thousands to millions, which is mutated at just a single nucleotide is like finding a needle in a haystack.
The experiments reported in the paper show that the LRA test was sensitive enough to find a commonly sought K103n mutation in concentrations as low as one mutant per 10,000 strands of ormalviral RNA.
LRA works by sending in many copies of a pair of short engineered probes of genetic material to complement the RNA in the HIV sample.
those pairs that perfectly match the target HIV RNA containing a mutation that causes drug resistance can rapidly become fused together,
Aiming for the clinic The development of LRA is the product of a collaboration led by Tripathi and Dr. Rami Kantor, associate professor of medicine in the Warren Alpert Medical school.
Kantor, who is also an HIV specialist at The Miriam Hospital and co-senior author of the paper, works in developing nations such as Kenya and India, monitoring HIV resistance.
One day when Tripathi was at the Lifespan/Tufts/Brown Center for AIDS Research Retrovirology Core Laboratory to discuss his work,
quick and accurate HIV drug resistance mutation detection system for use in developing nations. e met soon thereafter
assistant professor of medicine and a co-author on the paper. he next steps are to continue the development of LRA
and other methods on patient samples to detect additional mutations and address specific HIV challenges related to mutation detection,
such as enormous genomic diversity, Kantor said, nd work on incorporation of such methods onto a point-of-care device that would satisfy the infrastructure and low-cost needs of resource limited settings. s
#New graphene based inks for high-speed manufacturing of printed electronics A low-cost, high-speed method for printing graphene inks using a conventional roll-to-roll printing process,
including inexpensive printed electronics, intelligent packaging and disposable sensors. Developed by researchers at the University of Cambridge in collaboration with Cambridge-based technology company Novalia,
the method allows graphene and other electrically conducting materials to be added to conventional water-based inks
the first time that graphene has been used for printing on a large-scale commercial printing press at high speed.
Its flexibility, optical transparency and electrical conductivity make it suitable for a wide range of applications, including printed electronics.
Although numerous laboratory prototypes have been demonstrated around the world, widespread commercial use of graphene is yet to be realised. e are pleased to be the first to bring graphene inks close to real-world manufacturing.
who developed the method. eing able to produce conductive inks that could effortlessly be used for printing at a commercial scale at a very high speed will open up all kinds of different applications for graphene
and other similar materials. his method will allow us to put electronic systems into entirely unexpected shapes,
Hasan method, developed at the University Nanoscience Centre, works by suspending tiny particles of graphene in a arriersolvent mixture,
The same method works for materials other than graphene including metallic, semiconducting and insulating nanoparticles. Currently, printed conductive patterns use a combination of poorly conducting carbon with other materials, most commonly silver,
which is expensive. Silver-based inks cost £1000 or more per kilogram, whereas this new graphene ink formulation would be 25 times cheaper.
reducing energy costs for ink curing. Once dry, the lectric inkis also waterproof and adheres to its substrate extremely well.
which is in line with commercial production rates for graphics printing, and far faster than earlier prototypes.
Through the use of this new ink, more versatile devices on paper or plastic can be made at a rate of 300 per minute, at a very low cost.
Hasan and Phd students Guohua Hu Richard Howe and Zongyin Yang of the Hybrid Nanomaterials Engineering group at CGC, in collaboration with Novalia, tested the method on a typical commercial printing press,
which required no modifications in order to print with the graphene ink. In addition to the new applications the method will open up for graphene,
it could also initiate entirely new business opportunities for commercial graphics printers, who could diversify into the electronics sector. he UK,
and the Cambridge area in particular, has always been strong in the printing sector, but mostly for graphics printing and packaging, said Hasan,
a Royal Academy of Engineering Research Fellow and a University Lecturer in the Engineering Department. e hope to use this strong local expertise to expand our functional ink platform.
In addition to cheaper printable electronics, this technology opens up potential application areas such as smart packaging and disposable sensors,
which to date have largely been inaccessible due to cost. In the short to medium term, the researchers hope to use their method to make printed, disposable biosensors,
energy harvesters and RFID tags s
#Transplanting from Pig to Human Never before have scientists been able to make scores of simultaneous genetic edits to an organism genome.
But now, in a landmark study by George Church and his team at the Wyss Institute for Biologically Inspired Engineering at Harvard university and Harvard Medical school, the gene editing system known as CRISPRAS9 has been used to genetically engineer pig DNA
in 62 locationsn explosive leap forward in CRISPR capability when compared with its previous record maximum of just six simultaneous edits.
Artistic rendering shows pig chromosomes (background) which reside in the nucleus of pig cells and contain a single strand of RNA,
and the Cas9 protein targeting DNA (foreground. Image credit: Wyss Institute at Harvard Universitythe 62 edits were executed by the team to inactivate native retroviruses found in the pig genome that have inhibited so far pig organs from being suitable for transplant in human patients.
With the retroviruses safely removed via genetic engineering, however, the door is now open on the possibility that humans could one day receive lifesaving organ transplants from pigs.
Church is the Robert Winthrop Professor of Genetics at Harvard Medical school and a Wyss core faculty member.
The advance, reported by Church and his team, including the study lead author, Luhan Yang, a research fellow at HMS and the Wyss, was published in the October 11 issue of Science.
The concept of xenotransplantation, which is the transplant of an organ from one species to another,
is nothing new. Researchers and clinicians have hoped long that one of the major challenges facing patients suffering from organ failurehe lack of available organs in the United states
and worldwideould be alleviated through the availability of suitable animal organs for transplant. Pigs in particular have been especially promising candidates due to their similar size and physiology to humans.
In fact pig heart valves are sterilized already commonly and decellularized for use in repairing or replacing human heart valves.
But the transplant of whole, functional organs composed of living cells and tissue has presented a unique set of challenges for scientists.
One of the primary problems has been the fact that most mammals, including pigs, contain repetitive,
latent retrovirus fragments in their genomes, present in all their living cells, that are harmless to their native hosts
but can cause disease in other species. he presence of this type of virus found in pigsnown as porcine endogenous retroviruses,
or PERVSROUGHT more than a billion dollarsworth of pharmaceutical industry investments in developing xenotransplant methods to a standstill by the early 2000s, said Church.
ERVS and the lack of ability to remove them from pig DNA was a real showstopper on
what had been a promising stage set for xenotransplantation. ow, using CRISPRAS9 like a pair of molecular scissors, Church and his team have inactivated all 62 repetitive genes containing a PERV in pig DNA,
surpassing a significant obstacle on the path to bringing xenotransplantation to the clinic. With more than 120,000 patients currently in the United states awaiting transplants and fewer than 30
000 transplants on average occurring annually, xenotransplantation could give patients and clinicians an alternative in the future. ig kidneys can already function experimentally for months in baboons,
but concern about the potential risks of PERVS has posed a problem for the field of xenotransplantation for many years,
said David H. Sachs, director of the TBRC Laboratories at Massachusetts General Hospital, the Paul S. Russell Professor of Surgery Emeritus at HMS and professor of surgical sciences at Columbia
University Center for Translational Immunology. Sachs has been developing special pigs for xenotransplantation for more than 30 years
and is currently collaborating with Church on further genetic modifications of his pigs. f Church and his team are able to produce pigs from genetically engineered embryos lacking PERVS by the use of CRISPR-Cas9,
they would eliminate an important potential safety concern facing this field. ang says the team hopes eventually they can completely eliminate the risk that PERVS could cause disease in clinical xenotransplantation by using modified pig cells to clone a line of pigs that would have their PERV genes inactivated.
The remarkable and newly demonstrated capability for CRISPR to edit tens of repetitive genes such as PERVS will also unlock new ways for scientists to study
and understand repetitive regions in the genome, where an estimated more than two-thirds of our own human genome resides d
#Stressed dads affect offspring brain development through sperm microrna More and more, scientists have realized that DNA is not the only way that a parent can pass on traits to their offspring.
Events experienced by a parent over a lifetime can also have an impact. Now University of Pennsylvania researchers have shown at the molecular level how experiencing stress changes a male mouse sperm in such a way that it affects his offspring response to stress.
This change is imparted epigenetically, or through a means other than the DNA code, by molecules called micrornas, or mirs.
The work led by Tracy L. Bale, professor of neuroscience in Penn School of veterinary medicine and Perelman School of medicine, provides important clues for understanding how a father life experiences may affect his children brain development and mental health through a purely biological and not behavioral means. t remarkable to
me that seemingly mild stress to a male mouse would trigger this massive change in microrna response
and that that would get wired into the course of his offspring development, Bale said.
She collaborated on the work with graduate students Ali B. Rogers and Christopher P. Morgan and research specialist N. Adrian Leu of Penn Vet.
The paper will appear in Proceedings of the National Academy of Sciences. In earlier research
Bale lab had shown that male mice that were stressed, prior to being bred, by such means as changing cages or exposing them to a predator odor of fox urine,
had offspring with a dampened response to stress. When they compared sperm from the stressed fathers to their unstressed counterparts,
To find out, the team microinjected the nine mirs into mouse zygotes, which were implanted then into normal female mice who carried them as surrogates.
They also included control groups in which zygotes received either a sham injection or an injection of a single mir.
the researchers examined their response to stress, just as they had done in their 2013 study. he results mapped right onto
When subjected to a mild stress, in this case, being restrained briefly, the offspring that arose from the zygotes that received the multi-mir injections had lower cortisone levels compared to offspring in the control groups.
The mice in the multi-mir injection group also had significant changes in the expression of hundreds of genes in the paraventricular nucleus,
a brain region involved in directing stress regulation, suggesting widespread changes in early neurodevelopment. Finally the researchers aimed to determine how the mirs were carrying out this effect after fertilization.
Because mirs are known to target and degrade mrna, the team looked at the stored maternal mrna,
and exists for only a brief window of time to direct early zygotic development. eople used to think that
and performed control injections, but this time they incubated the zygotes for eight hours and then amplified the RNA in each single cell to look for gene expression levels.
They found that, indeed, the multi-mir injection appeared to be attacking the maternal mrna,
resulting in a reduction in those mrna levels compared to control injections. Specifically affected were involved genes in chromatin remodeling.
Bale suspects that when a male experiences stress it may trigger the release of mirs contained in exosomes from the epithelial cells that line the epididymis,
the storage and maturation site for sperm between the testes and the vas deferens. These mirs may be incorporated into the maturing sperm and influence development at fertilization.
Up next for the group, including Penn Vet graduate student Jen Chan, who is taking over the project,
such as providing stressed males with enrichment or a reward, might prevent them from passing on an abnormal stress response to the next generation.
The work was supported by the National Institute of Mental Health
#Researchers learn how to steer the heart with light We depend on electrical waves to regulate the rhythm of our heartbeat.
the result is a potentially fatal arrhythmia. Now, a team of researchers from Oxford and Stony Brook universities has found a way to precisely control these waves using light.
Their results are published in the journal Nature Photonics on 19 october. Both cardiac cells in the heart and neurons in the brain communicate by electrical signals,
electrical devices (pacemakers or defibrillators) or drugs (eg beta blockers. However, these methods are relatively crude: they can stop
borrowing tools from the developing field of optogenetics, which so far has been used mainly in brain science.
hen there is scar tissue in the heart or fibrosis, this can cause part of the wave to slow down.
we could prevent that. ptogenetics uses genetic modification to alter cells so that they can be activated by light.
A protein called channelrhodopsin was delivered to heart cells using gene therapy techniques so that they could be controlled by light.
Then, using a computer-controlled light projector, the team was able to control the speed of the cardiac waves,
In the short term, the ability to provide fine control means that researchers are able to carry out experiments at a level of detail previously only available using computer models.
potentially improving our understanding of how the heart works. The research can also be applied to the physics of such waves in other processes.
Dr Emilia Entcheva, from Stony Brook University, said: he level of precision is reminiscent of what one can do in a computer model,
except here it was done in real heart cells, in real time. recise control of the direction, speed and shape of such excitation waves would mean unprecedented direct control of organ-level function, in the heart or brain,
This ideal therapy has remained in the realm of science fiction until now. The team stresses that there are significant hurdles before this could offer new treatments a key issue is being able to alter the heart to be light-sensitised
as gene therapy moves into the clinic and with miniaturization of optical devices, use of this all-optical technology may become possible.
A supercomputer for the ong tailof science The San diego Supercomputer Center (SDSC) at the University of California, San diego this week formally launched omet,
a new petascale supercomputer designed to transform scientific research by expanding computational access among a larger number of researchers
said Jim Kurose, assistant director of the National Science Foundation for Computer and Information science and Engineering (CISE),
during remarks Oct 14 at the SDSC event. hrough this launch and the extraordinary computing capabilities of SDSC,
and engineering, allowing researchers to open new windows into phenomena as vast as the universe and as small as nanoparticles.
The result of an NSF award valued at roughly $24 million, including hardware and operating funds,
Comet joins SDSC Gordon supercomputer as another key resource within the NSF XSEDE (extreme Science and Engineering Discovery Environment) computer resource-sharing system
In his remarks, Kurose noted that cyberinfrastructureefined as a dynamic ecosystem consisting of advanced computing systems, data, software and, most importantly, people,
SDSC used the formal launch of Comet to also celebrate 30 years as a national resource for advanced computation.
as one of NSF original supercomputer centers, Kurose said. t has been a leader of the data science revolution as well.
The work done at SDSC has provided not only insights into fundamental science but it has included also a strong dedication to K-12 educational outreach.
and Society Comet is configured to help transform advanced computing by expanding access and capacity not only among research domains that typically rely on HPCUCH as chemistry
and biophysicsut among domains which are relatively new to supercomputers, such as genomics, finance and the social sciences.
Supercomputers can greatly accelerate timescales for researching the origins of the universe. Neurosciences, Brain Research:
SDSC Neuroscience Gateways project will contribute to the national BRAIN INITIATIVE announced by the Obama Administration to deepen our understanding of the human brain.
and the properties of social networks. Molecular Science: Studying the properties of lipids, proteins, nucleic acids, and small molecules can advance our understanding of biophysical processes at the atomic scale,
and reducing disease. DNA NANOSTRUCTURES: Conducting nanoscale biomolecular research could lead to low-cost DNA sequencing technologies,
and in turn create targeted drug delivery systems and help explain the molecular causes of disease.
Alternative energy Solutions/New Materials Research: Finding new and more efficient solutions to energy harvesting, nanoporous membranes for water desalinization, solar thermal fuels and more.
Fluid Turbulent Physics: Supercomputers can create highly detailed simulations to track ocean currents or improve industry methods related to the discharge of pollutants
or oil flow in pipelines. Climate change/Environmental sciences: Modeling atmospheric aerosols, identified as influencing the chemical composition
and radiative balance of the troposphere, has direct implications for our climate and public health. Seismic Research/Disaster Prevention:
Keys to hazard management for major earthquakes, hurricanes, and wildfires include the ability to predict a wide range of possibilities.
Supercomputer-generated simulations are used to inform decision-making strategies. The Tree of Life: Biologists construct phylogenetic trees to capture the evolutionary relationship between species,
and help us better understand the functions and interactions of genes, the origin and spread of diseases, the co-evolution of hosts and parasites and migration of human populations.
Key Features of Comet: 2 petaflops of overall peak performancene million billion operations or calculations per second.
Dell compute nodes using next-generation Intel Xeon processors, 27 racks of compute nodes totaling 1,
944 nodes or 46,656 cores. 128 gigabytes of dynamic RAM and 320 GB of flash memory per standard compute node. 72 nodes per rack with full bisection Infiniband
FDR interconnect in each rack, and a 4: 1 bisection cross-rack interconnect. Additional GPU and large-memory (1. 5 Terabytes) nodes for applications such as visualization, molecular dynamics simulations,
or de novo genome assembly. 7 petabytes of Lustre-based high-performance storage from Aeon, and 6 petabytes of durable storage for data reliability.
First XSEDE production system to support high-performance virtualization n
#Biomarker finder adjusts on the fly A Rice university laboratory has developed a continuously tunable method to find and quantify DNA and RNA biomarkers.
Rice bioengineer David Zhang and his colleagues have developed a unique way to adjust their nucleic acid probe reagents on the fly
and take a reliable count of target sequences. The work is detailed in an open-access paper this week in Nature Methods.
The ability to identify DNA or RNA sequences, especially mutations, has become critically important for the detection of diseases
and design of therapies to treat them. But finding a specific biomarker in a massive amount of genetic code is hard.
Zhang and his team at Rice Bioscience Research Collaborative have become specialists in finding such needles in haystacks.
In previous work, the lab designed probes that find single-nucleotide mutations in DNA while using ompetingprobes to bind to healthy sequences
and effectively get them out of the way. This time the lab is developing synthetic DNA rotectorsthat mimic the target sequence
and compete with the target in binding to the probes. By altering the stoichiometry, or the proportion of substances in chemical reactions, of these protectors, researchers can control the balance of the reactions so the fluorescent probesbrightness can be adjusted.
For example, Zhang said, there may be two biomarker sequences of interest, but the high expression of one would outshine the low expression of another.
Because the unit brightness of each biomarker can be adjusted, the researchersnew method allows the simultaneous and accurate observation of many biomarkers. n principle,
we should be able to tune indefinitely, he said. ut we be trading off time and labor and cost versus what people actually need.
If we can get 90 percent of the value in two steps, it probably doesn make sense to take five more steps for 95 percent.
Zhang, lead authors Lucia Wu and J. Sherry Wang and their colleagues have written software to help researchers design their own probes.
The Web-based program allows researchers to cut and paste gene sequences and highlight areas of interest to generate probe designs.
Probe design is complicated by the fact that researchers often look for many biomarkers at once, and that those biomarkers interact with each other,
Zhang said. n an age of advancing science and big data, we want to look at hundreds or thousands or millions of different DNA biomarker signatures. esearchers have to decide in advance
whether to measure how sensitive the target sequences are to their probes, or how specific they will be when binding,
he said. nfortunately, these two goals are mutually exclusive. If you improve the sensitivity, the specificity drops
and vice versa. hat wee done is alter the sensitivity and specificity of different probes in a way that independent and decoupled,
he said. e like to envision DNA as a plate of food, and our molecules as salt and pepper shakers:
We change the flavor of the DNA PROBE by salting it with a little more stoichiometry or peppering it with a little more of the protector. hat a reasonable analogy for
what wee doing: going in and changing the formulation, changing the stoichiometric ratios of things. That actually allows us to change the sensitivity and specificity of each individual probe.
In one of many successful tests, the lab designed molecules to detect mutation sequences in historic biopsy samples preserved in wax from cancer patients.
One of the researchersgoals is to design noninvasive cancer diagnostics that detect DNA biomarkers in blood samples for early screening and early recurrence detection.
faster and cheaper answers for researchers and clinicians who are looking at hundreds or thousands of different mutations,
and apply it to cancer detection a
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