Tech

A global campaign to help find a mate for a left-coiling snail called 'Jeremy' has enabled scientists to understand how mirror-image garden snails are formed.

The findings, published today in the journal Biology Letters, show that the rare left-spiralling shell of some garden snails is usually a development accident, rather than an inherited condition.

In October 2016, evolutionary geneticist Dr Angus Davison in the University of Nottingham's School of Life Sciences appealed to the public for their help in match-making for Jeremy, a garden snail with a rare left-coiling shell.

Dr Davison hoped to use the offspring from Jeremy to study the genetics of this condition, because his previous work on snails had given insight into understanding body asymmetry in other animals, including humans. But another left-coiling snail had to be found first. As well as a mirror-imaged shell, Jeremy had genitals on the opposite side making it very difficult for the snail to mate with normal snails.

The science to unravel this mystery was made possible by the involvement of the general public in finding a mate for Jeremy, initially via an appeal put out on BBC Radio Four's Today programme, and then the wider media using #snaillove.

Jeremy became a global sensation and internet 'shellebrity'. More than 1,000 news, radio, television and science articles, including the BBC and New York Times, highlighted the plight of the lovelorn snail. A graphic novel featuring the snail is now in development.

By bringing together a worldwide group of citizen scientists, and the snails that they had found, Dr Davison used the publicity to understand what makes an exceptional reversed-coiled snail such as Jeremy.

Altogether more than 40 lefty snails were found by citizen scientists, in the wild and from snail farms. Davison and the citizen scientists bred the lefty snails together to test whether their occurrence was due to an inherited condition. Over three years, nearly fifteen thousand eggs were hatched from four generations of snails, including Jeremy.

Initially, Jeremy had been left 'shell-shocked' after being given the cold shoulder by two suitors who seemed to prefer each other. Then, shortly before Jeremy's death, one mate produced a batch of 56 babies, about one-third of which were likely to be 'fathered' by Jeremy.

The new evidence shows that rare lefty garden snails are not usually produced due to an inherited condition. Instead, they are mainly produced by a developmental accident.

This finding has relevance to understanding the common factors that define animal asymmetry, including humans, and the origin of rare reversed individuals in other animal groups.

Dr Davison said: "After a long search for a mate, and several mishaps along the way, Jeremy finally produced offspring, which delighted me - and the rest of the world. We were then able to use Jeremy's offspring and the offspring from other lefties to discover how these mirror-imaged individuals are produced. Our findings showed that it is usually a developmental accident, rather than an inherited condition, that makes a lefty garden snail.

"We helped solve one of nature's puzzles, which was very satisfying. There was also a happy ending for Jeremy, the snail, in finding love and producing offspring, albeit just before dying. None of this would have been possible without the public's help.

"We have learned that two lefties usually make a right, at least if you are a garden snail. In other snails, being a lefty is an inherited condition, but we still don't really know how they do it. If we are able to find out, then this may help us understand how the right and left side of other animal bodies are defined, including ourselves.

"You could say that we tried to recreate what made Jeremy different, but this was not possible. Jeremy was special."

Working with computer models to predict the likely impact of climate change on invasive weed propagation, Dr Farzin Shabani from Flinders University's Global Ecology Lab found a likely increase in areas of habitat suitability for the majority of invasive weed species in European countries, parts of the US and Australia, posing a great potential danger to global biodiversity.

In predicting the impact of climate change on current and future global distributions of invasive weed species, Dr Shabani also found that existing attempts to eradicate invasive populations are inadequate.

Dr Shabani and an international team of researchers investigated 32 globally important Invasive Weed Species to assess whether climate alteration may lead to spatial changes in the overlapping of specific IWS globally.

"We aimed to evaluate the potential alterations - whether that be a gain, loss or static - in the number of potential ecoregion invasions by IWS, under climate change scenarios," says Dr Shabani. "We utilised all possible greenhouse gas concentration to examine a range of possible outcomes."

The paper - Invasive weed species' threats to global biodiversity: Future scenarios of changes in the number of invasive species in a changing climate, by Farzin Shabani, Mohsen Ahmadi, Lalit Kumar, Samaneh Solhjouy-fard, Mahyat Shafapour Tehrany, Fariborz Shabani, Bahareh Kalantar and Atefeh Esmaeili - has been published in the journal Ecological Indicators.

Initially, the researchers modelled the current climatic suitability of habitat for each of the weeds, identifying those with a common spatial range of suitability. They then modelled the suitability of all 32 species under the projected climate for 2050, incorporating different scenarios.

The final methodological step compared the extent of overlaps and alterations of weed habitats under the current and future projected climates.

"Under future climatic conditions, our results mainly predicted decrease on a global scale, with reduced areas of habitat suitable for most Invasive Weed Species - but significantly this excluded European countries, northern Brazil, eastern US, and south-eastern Australia, which are all highly productive agricultural regions," says Dr Shabani.

The study also revealed that Invasive Weed Species would most likely develop alterations in their habitat suitability in most parts of the world in the future.

"Even though our future projections indicate a decreasing rate in threats from invasive weeds in extensive areas across the world, the current distributions of many species still have a potential for expansion," says Dr Shabani.

"Many of these invasive weeds pose a threat in suitable habitats under both current and future climate conditions."

Dr Shabani is concerned that Invasive Weed Species are rarely mentioned in biodiversity policy documents, except to focus on a few high-profile species. "There are no comprehensive national invasive species statutory controls, which is our concern," he says. "We believe that a national framework is needed for prevention and early detection, along with a coherent policy framework, a robust monitoring framework, a fund for strategic research, and a national training and action program."

Overview

A joint research team of Hayato Kumagai in the latter half of the doctoral course and Kazuhiro Takahashi, Associate Professor in the Department of Electrical and Electronic Information Engineering of Toyohashi University of Technology, and Toshinori Fujie, Associate Professor (Lecturer) of the School of Life Science and Technology at the Tokyo Institute of Technology, have succeeded in developing a variable color sheet with a film thickness of 400 nanometers (less than one-hundredth of the thickness of a human hair) that changes color when stretched and shrunk. This variable color sheet utilizes the color generation by metal nanostructures formed in the elastomer sheet to achieve reversible wavelength control of transmitted light over a wavelength range of 495 to 660 nanometers through expansion and contraction. The developed stretchable color sheets are expected to be applied to adhesive-type display elements, as they can adhere to skin or be transferred to various electronic devices at room temperature utilizing the high adhesiveness of elastomers.

Details

Surfaces with periodic arrays of metal nanostructures can produce an effect called surface plasmon, which is the collective oscillation of electrons that respond to particular wavelengths of lights. Using this effect, color filters that allow light to transmit through a narrow nano-gap, through light could not originally pass without the effect, can be manufactured. This is known as the phenomenon of extraordinary optical transmission. Unlike conventional color filters that use pigments, color filters utilizing this principle of will not degrade over time and can be used as color filters for image sensors built into smartphones and other devices. Recently, dynamic color tuning, which forms metal nano periodic structures on elastic materials and displaces the period of the structures by expanding and contracting the sheet to change colors, has been studied as a method to control the wavelength of light that generates surface plasmons. This technology is expected to be applicable to flexible displays that are highly flexible in shape and form, as well as sensors that visualize structural strain, and the like.

However, in existing research reports, the thickness of the sheet supporting the nanostructures was in the order of millimeters, making it difficult to combine it with the drive mechanism using micromachine technology. In addition, the driving force required for the expansion and contraction of the support sheet is dependent on the thickness of the sheet. Therefore, thicker sheets pose the challenge of increasing the drive voltage of the micromachine device.

To solve the challenge, the research team developed stretchable color sheets using elastomer nanosheets made into thin film with a thickness of one micrometer or less, made of polystyrene-polybutadiene-polystyrene block copolymer (SBS), a type of rubber material used in automobile tires and other products. By embedding metallic nanostructures in elastomeric materials made into nano-thin film, extraordinary optical transmission using surface plasmons was confirmed. By applying strain to the nanosheets, we confirmed that the light transmitted through the sheets changed to blue, green, and red, and succeeded in dynamically controlling the extraordinary optical transmission with surface plasmon. Furthermore, we have demonstrated the wavelength of the transmission peak can continuously change in the range of 495 to 660 nanometers, and repeated expansion and contraction is possible. The driving force to expand and contract the color sheet which we developed is smaller by 2 to 3 orders of magnitude than conventional values and can be driven sufficiently by the force generated by ordinary microactuators. In addition, the adhesiveness of the elastomer makes it possible to attach the sheet to any place, enabling the detection and visualization of structural strain. By combining it with the micro-machine technology, we can expect to realize a variable color filter.

Future Outlook

The research team believes that the method could be applied to display elements that electronically change coloration by driving the stretchable color sheets with a micro-actuator. With the flexibility and adhesiveness of the sheet, it is expected to be used for electronic skin where it is pasted on human skin and displays images.

Recycling plastic faces several challenges, one of which is recycling different types of plastics together, because they have varying properties, each of which need to be addressed accordingly. Separating and treating each type of plastic adds to the cost of recycling plastic, which reduces the incentive to do so, despite the irreversible and detrimental biological cost of plastics in the environment.

Researchers Tingan LIN and Limin BAO of Shinshu University and their colleague examined the recyclability and sustainable development of thermoplastic materials. Material characteristics were also examined. A simple and fast treatment using a blending process would allow plastics to be useful again, rather than sitting in landfill. Plastics are the most used manmade material after steel and cement and they do not decompose like natural materials. This has lead to a lot of unwanted plastic in the environment. Melt or burn are the only ways to eliminate plastic waste, but cause other problems such as toxic fumes and add to global warming. Therefore, a method to melt different plastics together is urgently needed.

Polypropylene is a thermoplastics which means it is a plastic that can be heated and reshaped. It is used a lot in industry and household applications. The plastics examined in this study, thermoplastic polyurethane and polypropylene have significantly different melting points at 145 C° and 165 C°, so melting them together posed a challenge. To solve this issue, LIN et al. added an appropriate compatibilizer which acts as a go-between the plastics, which successfully enabled them to be processed together at the same time. The quality of the plastic was not undermined.

The researchers were able to efficiently produce thermoplastic blends using the melt extrusion process and injection molded process. Only a small amount of the compatibilizer, polypropylene grafted maleic anhydride was needed to do so. This finding would allow for unwanted plastic to be economically valued again and protect wildlife and the environment from further pollution. Professor Bao hopes to continue the study of thermal behaviors to see how they affect the reusability of thermoplastic-based materials.

For more information please read their paper: Polypropylene/thermoplastic polyurethane blends: mechanical characterizations, recyclability and sustainable development of thermoplastic materials.

Korea Brain Research Institute (KBRI, President Pann Ghill Suh) announced on May 26 that a joint research team, led by Prof. Joung-Hun Kim and Dr. Joo Han Lee at the Pohang University of Science and Technology (POSTECH), Dr. Ja Wook Koo at the KBRI, and Prof. Eric Nestler at the Icahn School of Medicine at Mount Sinai, discovered that dopamine D2 receptors (DRD2s) in cholinergic interneurons (ChINs) play a crucial role in cocaine addiction.

The findings were published in Biological Psychiatry, a leading academic journal in the field of psychiatry. The title and authors of the paper are as follows:

Title: Dopaminergic regulation of nucleus accumbens cholinergic interneurons demarcates susceptibility to cocaine addiction

Authors: Joo Han Lee (first author), Efrain A. Ribeiro, Jeongseop Kim, Bumjin Ko, Hope Kronman, Yun Ha Jeong, Jong Kyoung Kim, Patricia H. Janak, Eric J. Nestler, Ja Wook Koo, Joung-Hun Kim (corresponding author)

Drug addiction is a mental disorder, 'where' a person obsessively seeks out and uses drugs (narcotics) despite their harmful effects. It can lead to interpersonal conflict and physical health problems, thereby incurring significant social costs. Once consumed, drugs of abuse (e.g. cannabis and cocaine) increase the dopamine* concentration in the brain's reward system and activate dopamine receptors, which, in turn, causes intense craving for drugs.

Dopamine: A neurotransmitter released in the brain when a person is rewarded or exposed to addictive substances. It is commonly dubbed "the pleasure hormone."

Dopamine receptor: A receptor on a cell membrane that specifically binds and responds to dopamine

However, there are individual differences in drug addiction. Some people are more vulnerable to addiction when exposed to similar dose of addictive drug. Yet, the neurobiological mechanism underlying such phenomenon remains elusive.

By applying electrophysiological and optogenetic techniques to cocaine self-administration model, the research team identified DRD2* overexpression in cholinergic interneurons (ChINs) of the nucleus accumbens* (NAc) of mice susceptible to addiction.

Nucleus accumbens (NAc): a part of the brain's limbic system that plays a key role in processing rewarding and reinforcing stimuli

Cholinergic interneuron (ChIN): A nerve cell that releases the neurotransmitter acetylcholine (ACh) from the axon terminal. ChINs occupy 1-2 percents of the NAc neuronal poplulation.

DRD2 (dopamine D2 receptor): There are five subtypes of dopamine receptors (D1- D5), among which D1 and D5 belong to the D1-like family and D2, D3 and D4 to the D2-like family. DRD2 refers to a gene that expresses the D2 receptor.

Addiction-susceptible mice showed an increased level of DRD2 expression and a reduced level of cell activation, which is caused by dopamine D2 receptors expressed excessively in ChINs as the receptor activation reduces ChIN activity.

Through this mechanism, ChINs can affect the activation and synaptic plasticity of downstream medium spiny neurons (which comprise most of the NAc neurons) in diverse ways, thereby causing susceptibility to cocaine addiction.

"By exploring at the genome-wide level, the gene expressions within ChINs that occur in different individual entities, we have pioneered a new area in addiction research," the joint research team of KBRI and POSTECH said. "As a part of follow-up research, we will continue to study a detailed molecular mechanism underlying how addicted animals show elevated expressions of DRD2. Searching for any candidate drugs that can control such susceptibility by regulating activity of ACh receptors might be another feasible future plan."

This research was conducted as a KBRI in-house project supported by the Ministry of Science and ICT (MSIT), the Original Technology Research Program for Brain Science and the Research Leader Program.

With the continuous upgrading of electronic products, the development of high-energy power supplies has become a key link in the future development of science and technology. However, the shortage of lithium resources and the difficulty of recycling have become important factors in limiting their development.

Non-lithium based rechargeable batteries with inexhaustible supply of raw materials, such as sodium ion batteries (SIBs), have attracted widespread attention in recent years. As the critical determent for the energy output of SIBs, the development of cathodes has made exciting progress, such as layered materials, polyanions and Prussian blue analogs (PBAs), etc.

Among these cathodes, Mn-based Prussian blue analogues (Mn-Fe PBAs, Na2Mn[Fe(CN)6]) represent one of the most promising cathode materials for SIBs since of the higher theoretical capacity and adaptive volume variation. However, Mn-Fe PBAs suffer from poor cycling reversibility and capacity retention during phase transition from cubic to tetragonal phase, which is related to the large structural deformation of Mn-N6 octahedra caused by Jahn-Teller distortion.

Previous efforts on suppressing the large structural deformation mainly focused on optimized phase structure or partial atomic replacement, but these methods could not maintain a stable cycle while keep a high capacity, which is necessary for the practical application of batteries.

In the study that was published in Cell's Chem, the researchers have developed a controllable strategy to create unconventional cation Mn vacancies (VMn) on Mn-Fe PBAs by utilizing a strong chelating agent ethylenediaminet etraacetic acid disodium (Na2EDTA). The VMn in Mn-Fe PBAs could restrain the movement of Mn?N bonds and thereby mitigate the Jahn-Teller distortion of Mn-N6 octahedra, leading to highly reversible phase transitions of NMF as well as an outstanding long-term cycling stability and capacity retention (refer to image).

Due to the strong chelating effect of EDTA2-, Mn2+ and EDTA2- chelated to form highly stable six-coordinated octahedron that not only greatly slows down the release rate of Mn2+ as well as the formation rate of EDTA-NMF, but also removes the Mn atoms from the crystal lattice. With the reaction proceeds, the strong coordination of Na2EDTA would continue to etch the NMF and create more VMn on the surface.

The VMn in Mn-Fe PBAs could be acted as the first barrier to prevent the structural damage during battery cycling. As a result, the Mn-Fe PBAs exhibited an outstanding long-term cycling stability and capacity retention for both half-cell (72.3 % after 2700 cycles at 0.5 A g-1) and full-cell (75.5% after 550 cycles at 0.1 A g-1).

"Considering the facile synthesis and great diversity of PBAs, this work not only promotes creative synthetic methodologies for controllable defect or vacancy engineering, but also opens unlimited avenues to explore the relationship between structure, vacancies and electrochemical performances in materials beyond PBAs," said lead author Associate Professor Yang Hui Ying from SUTD.

The use of high-resolution peripheral quantitative computed tomography (HR-pQCT) to assess bone microarchitecture in clinical studies has continued to grow rapidly. Thus, there is an urgent need for guidance and consensus on the methods for and reporting of HR-pQCT imaging so that different studies can be compared to each other.

An important new position paper, published by a joint working group from the International Osteoporosis Foundation (IOF), the American Society for Bone and Mineral Research (ASBMR) and the European Calcified Tissue Society (ECTS), now addresses the need for standardization of techniques and terminology, provides guidance on interpretation and reporting of results, and discusses unresolved issues in the field.

Dr Nicholas Harvey, Professor of Rheumatology and Clinical Epidemiology at the University of Southampton, UK and Chair of the IOF Committee of Scientific Advisors, stated: "HR-pQCT is a powerful technology which provides novel insights into bone microarchitecture which are highly valuable to a broad range of bone-related research. These new guidelines, which are testament to the close collaboration between globally leading organizations in the bone field, provide direction on the technical aspects of HR-pQCT for use in the clinical setting, including best practices for acquisition and analysis of scans, as well as much needed guidance on the presentation and interpretation of results."

Specifically, the guidance provides:

standardized protocol for imaging distal radius and tibia sites using HRpQCT, with the importance of quality control and operator training discussed;

standardized terminology and recommendations on reporting results;

overview of factors influencing accuracy and precision error, with considerations for longitudinal and multicentre study designs;

a comparison of original and newer HR-QCT scanners with other high-resolution CT systems.

Senior author, Dr Mary Bouxsein, Director of the Center for Advanced Orthopaedic Studies, Beth Israel Deaconess Medical Center and Professor, Department of Orthopedic Surgery, Harvard Medical School added: "The implementation of these recommendations as best practices will help to facilitate the comparison of results across studies by minimizing technical variation in scan acquisition and analysis. We expect that this will be of enormous benefit to clinical research in the bone field and will support the further advancement of HR-pQCT for a variety of clinical applications."

Although the 2D semiconductor transistors keep the promise for future nanoelectronics, their applications are severely limited by the large contact resistance from the Schottky barrier between the deposited metal electrode and 2D semiconductor interface in the short-channel electronics for scaling integrated circuits. For now, to meet the requirements of ITRS (International Technology Roadmap for Semiconductors) 22-nm-node for the contact resistance, the heterophase engineering (such as 1T/2H-MoS2 and 1T'/2H-MoTe2) that substantially reduces the contact resistance seems to be the only solution. Therefore, in the past a few years, tremendous efforts have been made in the 2D phase engineering to achieve low-resistance contacts with 2D semiconductors for high-performance short-channel devices.

It is well known that the contact properties of such a metal-semiconductor TMDs phase boundaries are determined by their atomic structure, such as the nature of interface bonds and the relative orientation between metallic and semiconducting phases. In order to optimize the interfacial contact properties of 2D semiconductors, it is a prerequisite to understand the correlation between their characteristics and structures.

In a new research article published in the Beijing-based National Science Review, scientists at Peking University revealed the contact characteristics of the 1T'/2H-MoTe2 phase boundary using advanced scanning transmission electron microscopy and electron energy loss spectroscopy (EELS). They found that the contact characteristics of the phase boundary depend on the tilt angles between the metallic and semiconducting phases. For the phase boundary with a large tilt angle, the plasmon EELS clearly shifts to a lower energy loss, while there is no significant energy change at the phase boundary with a 0° tilt angle (a-b). Their findings indicate that the 0° tilted phase boundary has stronger atomic bonds and better contact performance. The scientists also unraveled the subtle influence of 1T' phase on 2H phase in the two unit cells near the phase boundary.

"The tilt-angle acts as a knob to tune the contact properties," the scientists stated. "Thus, future angle-controlled synthesis technologies may ultimately make short-channel transistors based on 2D heterostructures practical in nanoelectronics."

An international team with ties to UCF has cracked a challenge that could herald a new era of ultra-high-density computing.

For years engineers and scientists around the world have been trying to make smaller and faster electronics. But the power needed for today's design tends to overheat and fry the circuits. Circuits are generally built by connecting a diode switch in series with a memory element, called one diode-one resistor. But this approach requires large voltage drops across the device, which translates into high power, and hampers shrinking circuitry beyond a certain point as two separate circuit elements are required. Many teams are working on combining the diode and resistor into a single device.

These one-on-one molecular switches are great options, but they too have been limited to carrying out only one function and even then, they were often fraught with problems including unstable electrical voltage variances and limited lifespans.

The international team, led by Christian Nijhuis from the National University of Singapore and with co-authors Damien Thompson at the University of Limerick and Enrique del Barco the University of Central Florida, made the breakthrough detailed June 1 in the peer-reviewed journal Nature Materials.

The team created a new type of molecular switch that works as both a diode and a memory element. The device is 2 nanometers thick, the length of a single molecule (10,000 times smaller than the width of hair), and only requires a low drive voltage of less than 1 Volt.

"The community is quickly advancing in identifying novel electronic device applications at the molecular scale," says Del Barco, a professor who specializes in quantum physics. "This work may help speed-up development of new technologies involving artificial synapses and neural networks."

Nijhuis, who specializes in chemistry, led the team. Damien Thompson from the University of Limerick provided computational theory expertise and del Barco and his team of students and lab scientists provided the theoretical analysis.

How it works

The molecular switch operates in a two-step mechanism where the injected charge is stabilized by migration of charged ions between the molecules and the device surface. That's made possible by bonding the molecules in pairs. Using a combination of electrical measurements and atomic-scale measurements guided by quantum mechanics, the team found a sweet spot between stability and switch ability that yielded the dual diode+memory resistive RAM memory at a microscopic scale, according to the paper.

"There are still some challenges and more work in this area is needed, but this is a significant breakthrough," Nijhuis says.

Computer hard drives of the future could be made up of smart molecules.

Researchers have discovered a single molecule 'switch' that can act like a transistor and offers the potential to store binary information - such as the 1s and 0s used in classical computing.

The molecule is around five square nanometres in size. This means that more than one billion of them would fit onto the cross-section of a human hair.

The international team of scientists behind the breakthrough believe that molecules like the ones they have discovered could offer information density of around 250 terabits per square inch - which is around 100 times the storage density of current hard drives.

Although the researchers do not expect that the particular molecules they discovered will be used in real hard drives, the study is an important proof of concept that brings us closer to the brave new world of true molecular electronics.

In the study, molecules of an organic salt can be switched using a small electrical input to appear either bright or dark - providing binary information. Crucially, this information can be written, read and erased, at room temperature and in normal air pressures. These are important characteristics for practical application of the molecules in computing storage devices. Most previous research into molecular electronics for similar applications has been conducted in vacuum and at very low temperatures.

Dr Stijn Mertens, Senior Lecturer in Electrochemical Surface Science at Lancaster University and lead researcher on the study, said: "There is an entire list of properties that a molecule has to possess to be useful as a molecular memory. Apart from being switchable in both directions under ambient conditions, it has to be stable for a long time in the bright and dark state, and also spontaneously form highly ordered layers that are only one molecule thick, in a process called self-assembly. Ours is the first example that combines all these features in the same molecule."

In laboratory experiments, the research team used small electric pulses in a scanning tunnelling microscope to switch individual molecules from bright to dark. They were also able to read and erase the information afterwards, at the press of a button.

During the switching, the electric pulse changes the way the cation and the anion in the organic salt are stacked together, and this stacking causes the molecule to appear either bright or dark. Apart from the switching itself, also the spontaneous ordering of the molecules is crucial: through self-assembly, they find their way into a highly ordered structure (a two-dimensional crystal), without the need for expensive manufacturing tools as is the case in currently used electronics.

"Because chemistry allows us to make molecules with sophisticated functions in enormous numbers and with atomic precision, molecular electronics may have a very bright future," says Dr Mertens.

Researchers have developed a new easy-to-use smart optical film technology that allows smart window devices to autonomously switch between transparent and opaque states in response to the surrounding light conditions.

The proposed 3D hybrid nanocomposite film with a highly periodic network structure has empirically demonstrated its high speed and performance, enabling the smart window to quantify and self-regulate its high-contrast optical transmittance. As a proof of concept, a mobile-app-enabled smart window device for Internet of Things (IoT) applications has been realized using the proposed smart optical film with successful expansion to the 3-by-3-inch scale. This energy-efficient and cost-effective technology holds great promise for future use in various applications that require active optical transmission modulation.

Flexible optical transmission modulation technologies for smart applications including privacy-protection windows, zero-energy buildings, and beam projection screens have been in the spotlight in recent years. Conventional technologies that used external stimuli such as electricity, heat, or light to modulate optical transmission had only limited applications due to their slow response speeds, unnecessary color switching, and low durability, stability, and safety.

The optical transmission modulation contrast achieved by controlling the light scattering interfaces on non-periodic 2D surface structures that often have low optical density such as cracks, wrinkles, and pillars is also generally low. In addition, since the light scattering interfaces are exposed and not subject to any passivation, they can be vulnerable to external damage and may lose optical transmission modulation functions. Furthermore, in-plane scattering interfaces that randomly exist on the surface make large-area modulation with uniformity difficult.

Inspired by these limitations, a KAIST research team led by Professor Seokwoo Jeon from the Department of Materials Science and Engineering and Professor Jung-Wuk Hong of the Civil and Environmental Engineering Department used proximity-field nanopatterning (PnP) technology that effectively produces highly periodic 3D hybrid nanostructures, and an atomic layer deposition (ALD) technique that allows the precise control of oxide deposition and the high-quality fabrication of semiconductor devices.

The team then successfully produced a large-scale smart optical film with a size of 3 by 3 inches in which ultrathin alumina nanoshells are inserted between the elastomers in a periodic 3D nanonetwork.

This "mechano-responsive" 3D hybrid nanocomposite film with a highly periodic network structure is the largest smart optical transmission modulation film that exists. The film has been shown to have state-of-the-art optical transmission modulation of up to 74% at visible wavelengths from 90% initial transmission to 16% in the scattering state under strain. Its durability and stability were proved by more than 10,000 tests of harsh mechanical deformation including stretching, releasing, bending, and being placed under high temperatures of up to 70°C. When this film was used, the transmittance of the smart window device was adjusted promptly and automatically within one second in response to the surrounding light conditions. Through these experiments, the underlying physics of optical scattering phenomena occurring in the heterogeneous interfaces were identified. Their findings were reported in the online edition of Advanced Science on April 26. KAIST Professor Jong-Hwa Shin's group and Professor Young-Seok Shim at Silla University also collaborated on this project.

Donghwi Cho, a PhD candidate in materials science and engineering at KAIST and co-lead author of the study, said, "Our smart optical film technology can better control high-contrast optical transmittance by relatively simple operating principles and with low energy consumption and costs."

"When this technology is applied by simply attaching the film to a conventional smart window glass surface without replacing the existing window system, fast switching and uniform tinting are possible while also securing durability, stability, and safety. In addition, its wide range of applications for stretchable or rollable devices such as wall-type displays for a beam projection screen will also fulfill aesthetic needs," he added.

Washington, DC - June 2, 2020 - To protect medical laboratory personnel from infection when testing clinical samples for SARS-CoV-2, most laboratories inactivate the virus before testing. , The effect of inactivation on the detection of results had not been determined, but the rate of false negatives for one time testing of inactivated virus has been estimated to range from 30% to 50%.

A team of investigators led by Chaofeng Ma of Xi'an Center for Disease Control and Prevention hypothesized that viral inactivation may contribute to false negatives. They have now tested several inactivation methodologies to determine if and to what extent they reduce detectible virus in a clinical sample. The research appears in the Journal of Clinical Microbiology, a publication of the American Society for Microbiology.

The investigators took clinical samples from 63 patients who had been infected with SARS-CoV-2. They first used a technology called digital PCR to determine the total number of virus particles in each sample.

They then inactivated virus from the samples and determined how much less virus was detectible at 2 sites within the genome, a gene that codes for the "nucleocapsid" protein and a section of genome called ORF 1ab.

The first inactivating treatment used a reagent called TRIzol and destroyed 47.54% of nucleocapsid genes, and nearly 40% of ORF 1ab.

The second inactivation treatment heated the samples to 56°C for 30 minutes and reduced the quantities of the two sections of genome by 48.55% and 56.40%, respectively. Heating to 80°C for 20 minutes reduced viral copy numbers further, and boiling, or autoclaving at 121°C left virtually no detectible virus.

Future studies should include inactivation reagents besides TRIzol, the researchers wrote. But for now, "...TRIzol is recommended for sample inactivation... as TRIzol has the least effect on RNA copy number among the tested methods."

CHAMPAIGN, Ill. -- From March to December every year, Humboldt penguins nest in vast colonies on the Peruvian and Chilean coasts. The lucky ones find prime habitat for their nests in deep deposits of chalky guano where they can dig out sheltered burrows. The rest must look for rocky outcrops or other protected spaces that are more exposed to predators and environmental extremes.

In a new study, researchers looked at metabolic markers in the blood of 30 Humboldt penguins nesting in the Punta San Juan Marine Protected Area in Peru. The scientists wanted to know if there were metabolic differences between penguins nesting in the guano-rich burrows and in the exposed areas.

Nesting success is critical to the Humboldt penguins' long-term survival as a species. Decades of aggressive guano harvesting in the late 19th and early 20th centuries - a practice eventually replaced with more sustainable methods - depleted the Peruvian coastline and near-shore islands of their historical bird guano deposits that provided habitat for nesting penguins. Guano mining, climate change and other threats have led to a dramatic decline in Humboldt penguin populations across their range. Today, there are only about 32,000 of the birds - down from hundreds of thousands less than a century ago - and their numbers continue to fall.

"Punta San Juan and other protected marine areas and reserves along the coast of Peru still provide some protected sites with good guano deposits that the penguins are able to dig into to make their nests," said Dr. Michael Adkesson, the vice president of clinical medicine for the Chicago Zoological Society, which operates Brookfield Zoo.

Adkesson led the research with David Schaeffer, a professor emeritus of veterinary clinical medicine at the University of Illinois at Urbana-Champaign; and Jeff Levengood, a researcher with the Illinois Natural History Survey.

"We know from studies by Peruvian biologists that penguins produce more chicks with higher survival rates when they are able to dig burrow nests into guano deposits," Adkesson said. "So we wanted to see if we could detect - based on the blood of these birds - metabolic differences that would indicate the penguins nesting in less ideal nest sites were using more energy to deal with the fact that they're more exposed to the weather and predators."

The task was a challenge because few studies have analyzed blood metabolites in birds and the researchers did not have a hypothesis about what they would find, said Schaeffer, who, with Levengood, conducted the statistical analyses of 19 saccharide metabolites.

Their work revealed that penguins in sheltered and unsheltered locations had consistent - and distinct - patterns of several sugars in their blood. The blood sugars that best predicted the birds' nesting habitat included arabinose, maltose, glucose-6-phosphate and levoglucosenone.

That last sugar is a metabolic byproduct of exposure to a pollutant, levoglucosan, which is generated by the burning of cellulose. Setting fire to agricultural waste is common in regions near the nesting colony. Forest fires also generate levoglucosan. This metabolite was higher in the birds in exposed nests.

"This unexpected finding is one of the few indicators that we have that the unsheltered penguins are being exposed to more air pollution than their counterparts in burrows," Schaeffer said.

The differences in the other saccharides likely reflect the extra metabolic stresses the penguins in exposed nest sites experience, the researchers said. More research is needed to tease out the relationships between these metabolites and their health.

"This is another tool in the toolbox of understanding what's going on with the penguins in this region," Adkesson said. "We know the penguins can adapt to the lack of good nesting habitat to some extent, but it's not ideal for the long-term survival of the species. We hope that by looking at what's going on in their blood we can better predict how changes in the environment will affect their health and reproductive success, with the ultimate goal of shaping conservation strategies that protect the penguins and their habitat."

Neutrons - Deuterium shuffle

Scientists have found a new method to strategically add deuterium to benzene, an aromatic compound commonly found in crude oil. When applied to the active ingredient of drugs to incorporate deuterium, it could dramatically improve the drugs' efficacy and safety and even introduce new medicines.

To validate the method, which was published in Nature, a team led by W. Dean Harman of the University of Virginia worked with Xiaoping Wang at the Oak Ridge National Laboratory's Spallation Neutron Source. Wang successfully verified the exact position of deuterium atoms that resulted from the selective deuteration of benzene molecules using single crystal neutron diffraction.

"Because the high sensitivity of neutrons to hydrogen and its deuterium isotope, we were able to quantitatively assign not only the positions of the deuterium atoms at the atomic level, but also determine precisely how many were added on each side of the benzene molecule," Wang said. "This is important in designing new therapeutic drugs."

Ecology - Thinning forests

A multi-institutional research team found that changing environmental conditions are affecting forests around the globe, leading to increasing tree death and uncertainty about the ability of forests to recover.

Increases in atmospheric carbon dioxide, temperature, drought and extreme events such as wildfires are causing more frequent tree mortality and triggering intense competition among saplings for resources. This competition contributes to forest thinning, which limits the amount of carbon captured and held in tree trunks, branches and roots.

"There's a lot of nuance just in the carbon dioxide response," said Anthony Walker of Oak Ridge National Laboratory who contributed carbon dioxide analyses for the study published in Science. "We are examining the many tradeoffs and feedbacks. For instance, elevated carbon dioxide can spur tree growth while also increasing the risk of mortality associated with faster growth rates."

The study concluded that pervasive shifts in forest vegetation are likely to accelerate in the future.

Fusion - ITER assembly begins

ITER, the world's largest international scientific collaboration, is beginning assembly of the fusion reactor tokamak that will include 12 different essential hardware systems provided by US ITER, which is managed by Oak Ridge National Laboratory.

The systems include superconductors for the toroidal field magnet system and ORNL-developed pellet injection technology for plasma fueling and performance. These critical components will help ITER achieve its mission to demonstrate a self-heated, burning plasma and 500 megawatts of fusion power.

The 60-foot-tall central solenoid magnet, also fabricated under ORNL management, is considered the "heart of ITER" because it will initiate and drive plasma current inside the tokamak.

"The start of ITER tokamak assembly is a momentous milestone for the project and makes the fusion community -- at Oak Ridge and around the world -- excited for the future," Kathy McCarthy, US ITER project director, said.

The first shipment of central solenoid modules to ITER, located in southern France, will begin later this year.

Isotopes - Improved process for medicine

Oak Ridge National Laboratory researchers have discovered a better way to separate actinium-227, a rare isotope essential for an FDA-approved cancer treatment.

To produce Ac-227, researchers recover radium-226 from obsolete medical devices and fabricate it into targets that are irradiated in the High Flux Isotope Reactor. Ac-227 is then separated from the targets and purified.

Initially, researchers used caustic solution to dissolve targets, but recently they developed an approach using an acidic solution.

"From that one simple step, we increased actinium yield, minimized waste production, optimized our processing timeframe and made it easier to recycle radium," said ORNL's Roy Copping. "This is an important project for the lab, and it's of enormous benefit to mankind."

INDIANAPOLIS -- In a peer-reviewed commentary published in npj Digital Medicine, experts from Regenstrief Institute, Mayo Clinic and The Pew Charitable Trusts write that matching patient records from disparate sources is not only achievable, but fundamental to stem the tide of the current pandemic and allow for fast action for future highly contagious viruses.

Specifically, rapid identification of COVID-19 infected and at-risk individuals and the success of future large-scale vaccination efforts in the United States will depend, in part, on how effectively an individual's electronic health data is securely shared among healthcare providers, care settings including hospitals and pharmacies, and other systems used to track the illness and immunization.

For data sharing to be effective, electronic health records (EHRs) -- both those held within a single facility and those in different healthcare organizations -- must correctly refer to a specific individual. Is Billy Jones known at a different doctor's office as William Jones and are all his health records linked? To which Maria Garcia do lab test results belong? Which John Smith was referred to during contact tracing?

Unfortunately, the commentary notes, patient matching rates vary widely, with healthcare facilities failing to link records for the same patient as often as half the time. Authors Shaun Grannis, M.D., vice president for data and analytics at Regenstrief Institute and Regenstrief Professor of Medical Informatics at Indiana University School of Medicine; John D. Halamka, M.D., president of Mayo Clinic Platform and Ben Moscovitch, director of The Pew Charitable Trusts' health information technology initiative, call for stakeholders to urgently address the patient matching conundrum. Otherwise, the commentary says, efforts to curtail the current pandemic and future ones will be ill-advisedly delayed.

"...the sharing of more data and use of standards -- reflect near-term opportunities that government and health care organizations can implement to respond to the current pandemic and prepare for future ones. In the longer term, there may be other opportunities -- such as use of biometrics, unique identifiers, or multi-factor authentication -- that could further enhance patient identification and matching, including for routine care. However, those options -- and the associated standards that underlie their success -- while worthwhile to examine, cannot be designed, deployed, and implemented in a near-term manner that could help mitigate the effects of this pandemic," the commentary states.