Brain

Skoltech researchers and their colleagues have shown that LATP, a solid electrolytes considered for use in next-generation energy storage, is highly sensitive to water, which has direct implications for potential battery performance and lifetime. The paper was published in the journal Chemistry of Materials.

Although renewable energy sources attract much interest all over the world due to green technologies and high conversion efficiency, their integration remains a challenge as renewables are inherently cyclic and inconsistent. As night follows day and calm follows wind, the idle mode follows power generation. Evidently, such an unpredictably intermittent power supply will hardly meet consumers' expectations, but there is a solution that can overcome this obstacle, namely energy storage grids. These systems are expected to collect spontaneously generated energy and then distribute it on-demand, providing stable and flexible power delivery.

Among the wide range of energy storage systems, redox-flow batteries seem to be the most appropriate due to easy scalability, operation, and controllable output power. A redox flow battery is, in a way, a conventional battery turned inside out: electrodes become liquids (anolyte and catholyte) while the ion-conductive electrolyte becomes a solid membrane. The properties of this membrane determine final performance and lifetime of the battery, so scientists are considering various materials, both inorganic and polymeric, that would be suitable for this purpose.

One of these compounds is Li1.3Al0.3Ti1.7(PO4)3, or LATP. It is a well-known lithium conductive material belonging to the NASICON-family (named after the first well-described sodium-conductive representatives -- Na Super Ionic CONductor). This family is defined by a similar crystal structure that determines its high ionic conductivity.

LATP conductivity and structural features are described quite thoroughly, yet its stability towards ordinary environmental factors, such as air and water, remains poorly understood. So Mariam Pogosova of the Skoltech Center for Energy Science and Technology and her colleagues decided to find out whether pure water influences LATP properties.

"LATP triggered our scientific curiosity. A well-known superionic conductor, LATP has a high potential for further chemical and technological improvement. We knew its limitations, such as poor mechanical properties (brittleness) and instability towards metallic lithium. However, these limitations were quite acceptable as we planned to compensate them through the creation of composite material. So, we started our experiments," Pogosova explains.

Earlier studies by the group showed that LATP ceramics were losing conductivity rather drastically when stored for several days in both ambient air and argon. The researchers hypothesized that humidity might play a key role in this degradation and set out to explore LATP exposure to water.

First, the scientists synthesized LATP through the original two-stage solid-state reaction. They then put their samples in deionized water and left for different periods of time up to 12 hours and conducted subsequent electrochemical, structural, chemical, morphological analyses supported by theoretical modeling.

The experiments showed that LATP ceramics degrade significantly in contact with the water, losing up to 64% in total ionic conductivity after approximately two hours of exposure. The scientists also observed a bunch of other evidence of degradation: microcracking, grain's shape distortion, formation of nanoparticles, chemical composition shifts, unit cell shrinkage, and intrastructural polyhedra and strain changes. All of this led them to conclude that LATP ceramics are highly sensitive to water and probably unsuitable for use in aqueous redox flow batteries.

"Evidently, the impact of water is a concern for pure LATPs and their suitability for redox-flow systems, especially aqueous ones. I want to stress that the deionized water/LATP system analyzed in this study doesn't represent the real redox-flow battery conditions, as the anolyte/catholyte solutions are more complex. Therefore, at this point, I wouldn't try to predict the future of LATP. Nevertheless, I believe the fundamental knowledge obtained is already valuable and applicable: any kind of water is now clearly a reason to be on the alert. For example, now we can preserve the initial performance of LATP ceramics through a simple drying-and-vacuum treatment," Mariam Pogosova says.

She also notes that, surprisingly, their research is the first thorough and versatile study of water impact on LATP. "So we are surely planning more studies in order to refine LATP behavior in other media, to reveal whether it is going to perform well under redox-flow conditions", Pogosova adds.

The challenge of diversifying STEM fields may get a boost from the results of a new study that show field courses help build self-confidence among students--especially those from underrepresented groups.

Field courses build the self-confidence and "scientific competence" of all students, but the benefits are particularly noteworthy for students from groups that are underrepresented in STEM fields, who are more likely to switch majors or drop out of college, according to researchers at UC Santa Cruz who have published the results of the study in the journal Ecology and Evolution.

The article, "Field Courses Narrow Demographic Achievement Gaps in Ecology and Evolutionary Biology," sheds light on the benefits field courses offer students and the role they could play in boosting the retention and success of underrepresented students.

The study compared UCSC undergraduates admitted from 2008 to 2019 who participated in a field course to those who did not. Demographic data for race/ethnicity, socioeconomic status, first-generation college student, and gender were collected. In addition to greater self-confidence, the findings reveal that students who take field courses are more likely to graduate from college, have higher GPAs at graduation, and are more likely to stay in the ecology and evolutionary biology major. Even a modest, two-unit field course produces benefits for students: at UCSC, Biology 82: Introduction to Field Research meets once a week with two overnight weekend field trips.

"Field courses offer some potentially high-impact services that aren't available in traditional lecture courses," said postdoctoral researcher and first author Roxanne Beltran. "Students in field courses work as a team and collaborate rather than compete for the best grade. They get to sit around a campfire and feel like part of a community. And they are interacting with faculty who aren't standing behind a lectern, which can be intimidating."

As participants build confidence in field courses, the experience creates "a self-fulfilling prophecy of success," she said. "It's a feedback loop. Students see that they can be successful, which builds their confidence, which leads to further success."

Beltran, who is completing a two-year fellowship funded by the National Science Foundation and the UC President's Postdoctoral Fellowship Program, says field courses are one of the best investment colleges and universities can make in "saving dreams" of aspiring scientists.

"Diversity in STEM fields is critical," said Beltran. "Scientists can help solve global challenges like disease outbreaks and climate change. But we can't do that without the diversity of ideas that comes from diverse experiences. Our success is tied unequivocally to the diversity of the scientists doing the work."

Saving dreams and closing demographic gaps

For aspiring biology majors, the first two years of college courses are dominated by what some call the "math-science death march": a series of required courses in math, chemistry, physics, and biology that are a far cry from the vision that propels most undergraduates.

"Students who want to do biology in college have a vision of studying trees, or birds, or soils, or marine invertebrates in the intertidal zone," said senior author Erika Zavaleta, a professor of ecology and evolutionary biology at UCSC. "They have a vision of discovery, of being outside, of doing data collection."

Field courses give students hands-on experience doing science in collaboration with their peers: identifying species, designing and conducting experiments, analyzing data, and doing oral presentations of results. "Field courses have a big positive impact on students' sense of their scientific capacity," said Zavaleta. "It's true for all students, but it's bigger for underrepresented groups than any other."

In the study, which focused on the self-efficacy benefits of field courses, underrepresented students ranked their own sense of ability lower before they participated in the field course, but they emerged from the course with their sense of self-efficacy on par or ahead of their non-underrepresented peers, she noted.

"The course closed a demographic gap," said Zavaleta. "That's so exciting."

Field courses may be more expensive than large lecture courses, which Zavaleta said are "very efficient." "But you get what you pay for," she said. "The impact on students is greater. We need to rethink how much we invest in these experiences."

"If students have an early opportunity that validates what being a scientist is, that can carry them and keep them going until they get upper-division opportunities to do an internship, or a research project, or a senior thesis," said Zavaleta. "Let's give these students the opportunity to do what they came here to do before they get to year three of their college experience."

Retaining diversity in STEM

Undergraduates from diverse demographic backgrounds arrive at college equally interested in studying biology, but students from groups that are underrepresented in STEM fields are significantly less likely to earn a biology degree, either because they switch majors or leave campus entirely, said Zavaleta. That phenomenon, which takes place at colleges and universities across the country, has put the focus on retaining STEM students.

"They're coming to us across the board wanting to do biology, and it's on us to keep them and help them succeed," said Zavaleta, noting that most students leave the Ecology and Evolutionary Biology major during their first year or two.

Boosting self-efficacy is one part of a retention strategy, but efforts must also address building a sense of belonging and a sense of community for underrepresented students, noted Zavaleta, a veteran field-course instructor. "Field courses are such an important tool because they tackle both," she said. "There's nothing like making a meal together on a camping trip, or identifying a grass, or sloshing in a stream, or sitting around a campfire to build a sense of community."

Beltran, a UCSC alumna, recalled struggling to find her place in 400-student lecture courses before she enrolled in a quarter-long field course with Zavaleta. "I'm studying these students, because I was one of them," said Beltran. "I was questioning whether I deserved to be in college, and whether I could have a career in science." The field course rekindled the desire she'd had in high school, and in July, she will join the UCSC faculty as an assistant professor of ecology and evolutionary biology (EEB).

"The emphasis was really different when I was an undergraduate student," she said. "We've learned a lot since then about the importance of teaching in nontraditional ways."

Encouraging all students to feel welcome

In the study, the researchers found that underrepresented students are less likely to enroll in field courses. That problem, however, is not insurmountable.

"We've spent five years flipping that," said Zavaleta, a dedicated advocate of STEM diversity who received a $1 million grant in 2017 from the Howard Hughes Medical Institute to fund a five-year effort to support students in ecology and conservation biology all the way through to graduation. Her program provides increased access to research-based field courses and internships, as well as mentoring and a supportive community, with the goal of launching a diverse new generation of conservation leaders.

"We think of field courses as gated and maybe elitist, because they can be expensive, or we think they're only for students who already have camping equipment and experience," said Zavaleta. But those barriers can be overcome, she said. When Biology 82 was introduced, instructors Don Croll and Gage Dayton made a concerted effort to get the word out to all students through UCSC's ten colleges, student groups and organizations, and academic advisers. Scholarships remove cost barriers, and the relatively small weekend time commitment helps make the course available to students who work, she noted.

"Over time, the word gets out, and now we have students across campus participating--not just white students, not just wealthy students, not just biology students, and most haven't camped before," said Zavaleta, noting that Biology 82 is offered six times per year but still can't meet student demand. "If you tackle the relatively easy barriers, field courses become an engine for inclusion and equity."

Zavaleta is excited by the results of the study "because they show us that it's true."

"Why can't every student in the major have a field experience?" she asked. "Why can't every student in the division? Every student on campus? This is how UCSC started: It was all about inquiry in peer groups. We know how to do this, and we are doing it. We just need to do it for everybody."

An international multicentre study describes a rare disease characterized by a series of recognizable facial features, cardiac defects and intellectual disability, which they propose to name as TRAF7 syndrome -according to the name of the gen that causes this pathology.

The study, published in the journal Genetics in Medicine, is led by a team of the Faculty of Biology of the University of Barcelona and the Institute of Biomedicine of the University of Barcelona (IBUB), the Rare Diseases Networking Biomedical Research Centre (CIBERER) and the Research Institute Sant Joan de Déu (IRSJD), in collaboration with experts from the French Institute of Health and Medical Research (INSERM).

In this research, the experts identified forty-five patients -who were not diagnosed before- with whom they could gain knowledge on this new syndrome, so far defined with an only previous article based on the study of seven people.

With the analysis of new patients, the authors described the clinical picture associated with the TRAF7 syndrome, featured by intellectual disability, motor delay, specific facial features, hearing loss, a heart congenital malformation -patent ductus arteriosus- and skeletal defects in fingers, neck and chest.

Apart from defining the TRAF7 syndrome-associated phenotype spectrum, the authors of the new study analysed the transcriptome -global expression analysis of all gens in a cell- of fibroblasts -the most common type of cell in the connective tissue- in several patients and controls. Therefore, it is possible to offer an explanation on the altered pathways in case the gen mutates and the disease originates.

Among other features that can contribute to identify the affected patients are also the blepharophimosis (eyelids are horizontally shortened), short neck with back deviations, pectus carinatum (malformation in the chest where the chest wall is held in outward position), and macrocephaly.

Last, the team used a computer application -based on photographs of several patients- to get a robot portrait of the syndrome which could be of interest for the paediatricians who have to work with cases of this disease.

A team of researchers at UCLA has set a new record for preparing and measuring the quantum bits, or qubits, inside of a quantum computer without error. The techniques they have developed make it easier to build quantum computers that outperform classical computers for important tasks, including the design of new materials and pharmaceuticals. The research is published in the peer-reviewed, online open-access journal, npj Quantum Information, published by Nature and including the exceptional research on quantum information and quantum computing.

Currently, the most powerful quantum computers are "noisy intermediate-scale quantum" (NISQ) devices and are very sensitive to errors. Error in preparation and measurement of qubits is particularly onerous: for 100 qubits, a 1% measurement error means a NISQ device will produce an incorrect answer about 63% of the time, said senior author Eric Hudson, a UCLA professor of physics and astronomy.

To address this major challenge, Hudson and UCLA colleagues recently developed a new qubit hosted in a laser-cooled, radioactive barium ion. This "goldilocks ion" has nearly ideal properties for realizing ultra-low error rate quantum devices, allowing the UCLA group to achieve a preparation and measurement error rate of about 0.03%, lower than any other quantum technology to date, said co-senior author Wesley Campbell, also a UCLA professor of physics and astronomy.

The development of this exciting new qubit at UCLA should impact almost every area of quantum information science, Hudson said. This radioactive ion has been identified as a promising system in quantum networking, sensing, timing, simulation and computation, and the researchers' paper paves the way for large-scale NISQ devices.

Increased frequency and severity of droughts threatens California's endangered salmon population--but pools that serve as drought refuges could make the difference between life and death for these vulnerable fish, according to a study by researchers from UC Berkeley and California Sea Grant, a partnership between NOAA and Scripps Institution of Oceanography at the University of California San Diego. The research could help resource managers strategically protect and restore salmon habitat.

The new study, published in the journal Global Change Biology, tracked nearly 20,000 tagged fish in Sonoma County streams over a seven-year period from 2011 to 2017. The Russian River watershed is home to a highly endangered population of coho salmon, which nearly collapsed in the early 2000's, but has been recovering since then through a conservation hatchery program and other efforts.

"We were able to measure survival during this historic drought, which will help us understand how future droughts will impact this population of salmon," says University of Wisconsin- La Crosse Assistant Professor Ross Vander Vorste, who conducted the analysis for the study as a UC Berkeley postdoctoral researcher in collaboration with California Sea Grant's Russian River Salmon and Steelhead Monitoring Program.

Climate change is projected to lead to more frequent and severe droughts in California. In the Russian River watershed, and elsewhere in coastal California, salmon spend much of their lives in small streams. These streams often dry up in places during hot, dry conditions, leaving pools of water that become disconnected or completely dry.

A major question has been to what extent habitat fragmentation caused by more severe drought threatens salmon survival, and just how much water is needed to support the salmon population through the dry summer months. Previous research by the team has shown that even a trickle of water through salmon rearing pools can keep salmon alive. With a larger dataset spanning an extreme drought, the new study provides insight into what habitats can serve as refuges during extreme conditions, and what physical and environmental conditions may influence survival of juvenile salmon.

Even during the most extreme drought years, the study found, summer survival in certain reaches was similar to survival in non-drought years, indicating that many stream pools act as drought refuges. In other reaches, lack of flowing water led to salmon being trapped in drying pools where they experienced high mortality.

"For the most part, as long as water persisted in pools throughout the summer, salmon were able to survive," says Vander Vorste. "So even though we saw decreased survival in many pools, there were some places that emerged as refuges."

"With the trend towards increasing drought, it's going to be harder and harder for these salmon to hang on," says California Sea Grant Extension Specialist Mariska Obedzinski, a Scripps researcher who heads the salmon monitoring program. "So it's really important that some of these pools did maintain conditions that supported survival. That gives us hope that there is at least some habitat out there that can support these fish during drought."

California Sea Grant's Russian River Salmon and Steelhead Monitoring Program works closely with resource managers in the Russian River watershed, providing current data on salmon survival and monitoring stream conditions throughout the year, informing streamflow augmentation projects as well as emergency fish rescue operations. The new study, which emerged from a partnership with the Russian River Coho Water Resources Partnership Program, provides new information that could help resource managers strategize as to what measures are most effective and feasible to protect salmon during a drought.

"There are limited resources to address streamflow issues, so this study helps focus our attention in certain areas," says Obedzinski. "There are different strategies for different conditions." Knowing which areas are likely to serve as refuges could lead managers to prioritize those areas for protection, while knowing what areas are most impaired in a drought can help prioritize areas for streamflow enhancement.

In addition to answering important questions for local salmon recovery, the study also informs broader ecological questions about the role of habitat fragmentation for endangered species.

"Drought is not only going to affect the Russian River, but will also affect streams and rivers up and down the West Coast and around the world. Identifying environmental factors that are limiting salmon survival during those periods is an important finding that could have broader implications," says Vander Vorste.

As computers get more powerful and connected, the amount of data that we send and receive is in a constant race with the technologies that we use to transmit it. Electrons are now proving insufficiently fast and are being replaced by photons as the demand for fiber optic internet cabling and data centers grow.

Though light is much faster than electricity, in modern optical systems, more information is transmitted by layering data into multiple aspects of a light wave, such as its amplitude, wavelength and polarization. Increasingly sophisticated "multiplexing" techniques like these are the only way to stay ahead of the increasing demand for data, but those too are approaching a bottleneck. We are simply running out of room to store more data in the conventional properties of light.

To break through this barrier, engineers are exploring some of light's harder-to-control properties. Now, two studies from the University of Pennsylvania's School of Engineering and Applied Science have shown a system that can manipulate and detect one such property known as the orbital angular momentum, or OAM, of light. Critically, they are the first to do so on small semiconductor chips and with enough precision that it can be used as a medium for transmitting information.

The matched pair of studies, published in the journal Science, was done in collaboration with researchers at Duke University, Northeastern University, the Polytechnic University of Milan, Hunan University and the U.S. National Institute of Standards and Technology.

One study, led by Liang Feng, assistant professor in the departments of Materials Science and Engineering and Electrical and Systems Engineering, demonstrates a microlaser which can be dynamically tuned to multiple distinct OAM modes. The other, led by Ritesh Agarwal, professor in the Department of Materials Science and Engineering, shows how a laser's OAM mode can be measured by a chip-based detector. Both studies involve collaborations between the Agarwal and Feng groups at Penn.

Such "vortex" lasers, named for the way their light spirals around their axis of travel, were first demonstrated by Feng with quantum symmetry-driven designs in 2016. However, Feng and other researchers in the field have thus far been limited to transmitting a single, pre-set OAM mode, making them impractical for encoding more information. On the receiving end, existing detectors have relied on complex filtering techniques using bulky components that have prevented them from being integrated directly onto a chip, and are thus incompatible with most practical optical communications approaches.

Together, this new tunable vortex micro-transceiver and receiver represents the two most critical components of a system that can enable a way of multiplying the information density of optical communication, potentially shattering that looming bandwidth bottleneck.

The ability to dynamically tune OAM values would also enable a photonic update to a classic encryption technique: frequency hopping. By rapidly switching between OAM modes in a pre-defined sequence known only to the sender and receiver, optical communications could be made impossible to intercept.

"Our findings mark a large step towards launching large-capacity optical communication networks and confronting the upcoming information crunch," says Feng.

In the most basic form of optical communication, transmitting a binary message is as simple as representing 1s and 0s by whether the light is on or off. This is effectively a measure of the light's amplitude -- how high the peak of the wave is -- which we experience as brightness. As lasers and detectors become more precise, they can consistently emit and distinguish between different levels of amplitude, allowing for more bits of information to be contained in the same signal.

Even more sophisticated lasers and detectors can alter other properties of light, such as its wavelength, which corresponds to color, and its polarization, which is the orientation of the wave's oscillations relative to its direction of travel. Many of these properties can be set independently of each other, allowing for increasingly dense multiplexing.

Orbital angular momentum is yet another property of light, though it is considerably harder to manipulate, given the complexity of the nanoscale features necessary to generate it from computer-chip-sized lasers. Circularly polarized light carries an electric field that rotates around its axis of travel, meaning its photons have a quality known as spin angular momentum, or SAM. Under highly controlled spin-orbit interactions, SAM can be locked or converted into another property, orbital angular momentum, or OAM.

The research on a dynamically tunable OAM laser based on this concept was led by Feng and graduate student Zhifeng Zhang.

In this new study, Feng, Zhang and their colleagues began with a "microring" laser, which consists of a ring of semiconductor, only a few microns wide, through which light can circulate indefinitely as long as power is supplied. When additional light is "pumped" into the ring from control arms on either side of the ring, the delicately designed ring emits circularly polarized laser light. Critically, asymmetry between the two control arms allows for the SAM of the resulting laser to be coupled with OAM in a particular direction.

This means that rather than merely rotating around the axis of the beam, as circularly polarized light does, the wavefront of such a laser orbits that axis and thus travels in a helical pattern. A laser's OAM "mode" corresponds to its chirality, the direction those helices twist, and how close together its twists are.

"We demonstrated a microring laser that is capable of emitting five distinct OAM modes," Feng says. "That may increase the data channel of such lasers by up to five times."

Being able to multiplex the OAM, SAM and wavelength of laser light is itself unprecedented, but not particularly useful without a detector that can differentiate between those states and read them out.

In concert with Feng's work on the tunable vortex microlaser, the research on the OAM detector was led by Agarwal and Zhurun Ji, a graduate student in his lab.

"OAM modes are currently detected through bulk approaches such as mode sorters, or by filtering techniques such as modal decomposition," Agarwal says, "but none of these methods are likely to work on a chip, or interface seamlessly with electronic signals."

Agarwal and Ji built upon their previous work with Weyl semimetals, a class of quantum materials that have bulk quantum states whose electrical properties can be controlled using light. Their experiments showed that they could control the direction of electrons in those materials by shining light with different SAM onto it.

Along with their collaborators, Agarwal and Ji drew on this phenomenon by designing a photodetector that is similarly responsive to different OAM modes. In their new detector, the photocurrent generated by light with different OAM modes produced unique current patterns, which allowed the researchers determine the OAM of light impinging on their device.

"These results not only demonstrate a novel quantum phenomenon in the light-matter interaction," Agarwal says, "but for the first time enable the direct read-out of the phase information of light using an on-chip photodetector. These studies hold great promise for designing highly compact systems for future optical communication systems."

Next, Agarwal and Feng plan to collaborate on such systems. By combining their unique expertise to fabricate on-chip vortex microlasers and detectors that can uniquely detect light's OAM, they will design integrated systems to demonstrate new concepts in optical communications with enhanced data transmission capabilities for classical light and upon increasing the sensitivity to single photons, for quantum applications. This demonstration of a new dimension for storing information based on OAM modes can help create richer superposition quantum states to increase information capacity by a few orders of magnitude.

Prior to European settlement, wetlands, lakes and streams were the major landscape features of the Chicago region.

Much of this has been altered or lost in the past 150 years, most notably by the reversal of the Chicago River in 1900 with the construction of the Sanitary and Ship Canal. Many animal species that lived in these habitats also disappeared.

Now, a group of graduate students at the University of Illinois at Chicago have quantified over a century of these changes in detail.

In a paper published in the journal Urban Ecosystems, students from the departments of earth and environmental sciences and biological sciences have measured both the extent of wetland loss in Cook County since the time of the river reversal and the alterations in the animal populations. The paper, which is the result of a class project for the course "Extinctions: Modern and Ancient," compares the changes in aquatic environments and fauna in Cook County during two intervals: 1890-1910 and 1997-2017.

"The areas of aquatic features from historical topographic maps were imported into a GIS database and compared with the modern United States Geological Survey's National Hydrography Dataset," said Joey Pasterski, UIC Ph.D. student in earth and environmental sciences and first author of the paper. "It demonstrates the utility of digitized museum collections for long term studies, and it provides further evidence of the uneven impact of urban development on native faunal communities, here specifically in Cook County."

Digitized maps of the region circa 1900 were used to estimate the area and distribution of wetlands and lakes for comparison with current patterns.

According to the researchers, the area of wetlands has decreased by more than 80%, with many of these being drained or converted into small and relatively isolated lakes and ponds. The remaining wetlands are also small and fragmented.

Museum records and natural history surveys from sources such as the Field Museum and the Chicago Academy of Sciences allowed them to reconstruct the historic existence of species in the wetlands and lakes for comparison with modern data.

The researchers found that 23 species of fish, 54 species of clams and snails, and three species of reptiles have disappeared locally. There also are many new invasive species.

All 25 aquatic birds reported from the 1890-1910 period still exist and an additional 13 have been reported in recent times. Increased observations by birders are cited as the potential factor for the number of new bird species recorded.

The students hope the study can help inform the direction of future research aimed at restoring the health of aquatic ecosystems within Cook County and elsewhere.

"This could spawn a series of similar studies to help improve the accuracy of our understanding of the long-term effects of urbanization on native communities across the world in varying climates, environments, and urban systems, with the expressed goal of improving the health of urban ecosystems," Pasterski said.

The Chicago region provides a case study of the impact of human landscape change on regional animal and plant life, notes Roy Plotnick, UIC professor of earth and environmental sciences.

"We err in thinking global change is just global warming. On all scales, humans have profoundly changed their environment," said Plotnick, who supervised the study and is senior author of the paper.

Acute postoperative pain control after Total Knee Arthroplasty (TKA) is important as the poorly controlled, persistent pain can cause delay in rehabilitation. The researchers define the purpose of this study to be the comparison of pain intensity during the early postoperative period (following the first and second surgeries) in patients who underwent bilateral, scheduled, staged TKAs.

The researchers enrolled 32 patients (64 knees) in this study and evaluated the number of requests for analgesic agents during the first 3 days after TKA, time to walking, and the Wong-Baker FACES pain assessment score (WBS).

Comparing the postoperative period post the first and second TKA, there were no significant differences in WBS 24, 48, and 72 hours postoperatively. The frequency of requests, and the total number of requests for analgesics did not differ when comparing the first and second TKA, at any interval. The total number of analgesic requests exhibited a moderately strong, positive correlation between the first and second TKA (p

Patients undergoing staged bilateral TKA experienced equivalent early postoperative pain when comparing their experience following their first and second TKAs. Therefore, regarding pain control following the second TKA, we recommend considering the analgesic administration schedule and requirements of the first TKA.

This article is open access and can be obtained from the following link: https://benthamopen.com/FULLTEXT/TOORTHJ-14-26

Quantum Hall effect (QHE) plays an important role in materials science and precision measurement. Due to the dissipationless edge states, QHE exhibits exotic transport properties with quantized Hall resistance of h/νe2 and vanishing longitudinal resistance. Here, h is Planck's constant, ν is Landau filling factor and e is electron charge. QHE usually originates from the formation of remarkable energy gap and the broken time-reversal-symmetry, which requires materials with high mobility, high magnetic field and ultralow temperature. These rigorous conditions greatly limit deep exploration and wide applications of QHE. Therefore, seeking QHE at weak or zero magnetic field and higher temperatures has become an important topic in physics and materials science. In 1988, Haldane theoretically proposed that QHE can be realized without applying external magnetic field, i.e. Chern insulator state or quantum anomalous Hall effect (QAHE). In 2013, QAHE with C=1 was experimentally observed in thin films of chromium-doped (Bi,Sb)2Te3 at temperature down to 30 mK. QAHE is also contributed by dissipationless chiral edge states while the realization of QAHE does not require external magnetic field. Thus, QAHE is more suitable for application in low-consumption electronics compared with QHE. However, only one dissipationless edge state can be realized at ultralow temperatures in the previous studies. Therefore, realizing multiple dissipationless edge states and increasing the working temperature of QAHE are not only the most important research topics in physical sciences, but also expected to promote the development of low-consumption electronics and integrated circuits.

Recently, a research collaboration led by Professor Jian Wang at Peking University, Professor Yong Xu and Professor Yang Wu at Tsinghua University has discovered high-Chern-number and high-temperature Chern insulator state in MnBi2Te4 devices, representing a great breakthrough in Chern insulators and topological quantum states. The paper entitled "High-Chern-Number and High-Temperature Quantum Hall Effect without Landau Levels" was published online in National Science Review. Professor Jian Wang at Peking University and Professor Yong Xu at Tsinghua University are corresponding authors of this paper. Jun Ge, Yanzhao Liu at Peking University and Jiaheng Li, Hao Li at Tsinghua University contributed equally to this work. The research team discovered Chern insulators with two dissipationless edge states (high-Chern-number Chern insulator) above 10 K in intrinsic magnetic topological material MnBi2Te4 devices. Furthermore, by reducing the thickness of MnBi2Te4 devices, they also discovered Chern insulator state with one dissipationless edge state at the temperature as high as 45 K (high-temperature Chern insulator state), much higher than the antiferromagnetic transition temperature (Néel temperature) of MnBi2Te4 devices. These discoveries indicate the exciting possibility that the Chern insulator state or QAHE may be possibly realized at room temperature if appropriate materials and parameters are selected, consequently leading to a new generation of low-consumption or dissipationless information highway and bringing about the information technology revolution.

MnBi2Te4 is a layered magnetic topological material. As shown in subfigure (a), monolayer MnBi2Te4 includes seven atomic layers in a unit cell, forming a Te-Bi-Te-Mn-Te-Bi-Te septuple layer (SL), which can be viewed as intercalating a Mn-Te bilayer into the center of a Bi2Te3 quintuple layer. The researchers fabricated several MnBi2Te4 devices with different thickness. In 9-SL and 10-SL MnBi2Te4 devices, a Hall resistance plateau with height of h/2e2 accompanied by nearly vanishing longitudinal resistance is observed under applying an external magnetic field of 5 T, which is characteristic of the Chern insulator with two dissipationless edge states (C=2) (subfigures (b), (c)). More interestingly, the C=2 Chern insulator state in 10-SL MnBi2Te4 device can sustain above 10 K. The researchers further studied the influence of thickness of MnBi2Te4 devices on Chern number. In 7-SL and 8-SL MnBi2Te4 devices, a quantized Hall resistance plateau h/e2 accompanying with nearly vanishing longitudinal resistance, i.e. Chern insulator state with C=1 is observed. More importantly, the Hall plateau shows nearly quantized resistance even at 45 K in 7-SL MnBi2Te4 device (subfigures (d), (e), (f)) and above 30 K in 8-SL MnBi2Te4 device, which are obviously higher than the Néel temperature (about 22 K) of MnBi2Te4 devices.

The observed high-Chern-number and high-temperature Chern insulator states require weak magnetic field due to the antiferromagnetic nature of MnBi2Te4 at zero magnetic field. As the ordinary QHE can also give rise to quantized Hall resistance plateau and vanishing longitudinal resistance, it is necessary to exclude the influence of Landau levels (LLs) induced by external magnetic field on the findings. The researchers firstly estimated the mobility of MnBi2Te4 devices, which is found to be ranging from 100-300 cm2 V-1 s-1. Such low mobility require an external magnetic field higher than 30 T for QHE with LLs to be observed, which is much higher than the quantization magnetic field in all MnBi2Te4 devices. The researchers further demonstrated that the sign of Chern number remains unchanged with the carrier type when applying back gate voltages, unambiguously excluding the possibility of the ordinary QHE with LLs.

The origin of the observed Chern insulator states is revealed by theoretical calculations. Ferromagnetic MnBi2Te4 is predicted to be the simplest magnetic Weyl semimetal, which possesses only one pair of Weyl points (WPs) near the Fermi level. Quantum confinement leads to the Chern insulator state and layer-dependent Chern number in few-layer MnBi2Te4, permitting the existence of multiple dissipationless edge states in the bulk band gap, which is consistent with the experimental findings. The discovery of high-Chern-number Chern insulator state also provides experimental evidences for the magnetic Weyl semimetal state in MnBi2Te4.

The high-Chern-number and high-temperature Chern insulator states discovered in the intrinsic magnetic topological materials will stimulate the exploration on room-temperature QAHE, and pave the way for great breakthroughs in physics, materials science and information technology.

Marine life off the West Coast, from Mexico up through Canada, inhabit the California Current. The cool, nutrient-rich water supports life from invisible phytoplankton to the economically important salmon, rockfish and Dungeness crab to the majestic orcas.

A new study led by the University of Washington finds that the animals' ability to breathe in that water may be key to where and when they thrive. The study, published May 15 in Science Advances, uses recent understanding of water breathability and historical data to explain population cycles of the northern anchovy. The results for this key species could apply to other species in the current.

"If you're worried about marine life off the west coast of North America, you're worried about anchovies and other forage fish in the California Current. Ultimately it's what underpins the food web," said lead author Evan Howard, a UW postdoctoral researcher in oceanography.

The study shows that species respond to how breathable the water is -- a combination of the oxygen levels in the water and the species' oxygen needs, which are affected by water temperature. The anchovy historical data matches this pattern, and it suggests that the southern part of their range could be uninhabitable by 2100.

"Climate change isn't just warming the oceans -- it is causing oxygen to decrease, which could force fish and other ocean animals to move away from their normal range to find higher-oxygen waters," Howard said.

Anchovy populations are known to cycle through time, but the reasons have been mysterious. Other explanations -- that drew on food supplies, predator-prey interactions, competition with other species, and temperature preferences -- failed to fully explain the anchovy populations cycles from the1950s to today, which have been carefully recorded.

Since the late 1940s, the California Cooperative Oceanic Fisheries Investigations, or CalCOFI, a partnership between California state and federal agencies, has monitored marine life and conditions offshore. It was established after the economically devastating crash of the sardine fishery in the 1940s with the goal of avoid another fisheries collapse and better understanding marine populations.

"They weren't just measuring anchovies, they were measuring everything they could get their hands on," Howard said. Because the anchovies are numerous and their populations soared after the sardine collapse, these fish provide a good record over time and space for the past half-century.

Previous research by the UW group showed that water "breathability," the combined effects of temperature and oxygen levels, are key for marine animals' survival. The 2015 research used models to combine the effects of warmer seawater that can hold less oxygen with marine animals' increased metabolic needs in a warmer environment.

The new study also drew on a 2018 paper that analyzed the oxygen needs for various types of marine animals at different water temperatures. The two previous studies focused on the future, under climate change, and the distant past, for a major extinction event.

Researchers combined observations with ocean models to fill gaps in the data and showed that the breathability index changes over time and corresponds with when anchovy populations rise and fall, and when they move deeper or closer to shore.

"This study is the first one that demonstrates on a timescale of decades that a species is responding in really close alignment with this metabolic index - how breathable the ocean in its habitat has become," said senior author Curtis Deutsch, a UW associate professor of oceanography. "It adds a new, independent line of verification that species in the ocean are arranged in accordance with how breathable their habitats are."

The authors then looked at the extent of anchovy habitat in the future under climate change. Projected changes in the water conditions will likely make the southern part of the anchovies' range, off the coasts of Mexico and Southern California, uninhabitable by 2100.

"We expect habitats to shift for all species that depend on oxygen for survival," Howard said. "If we understand how these animals are responding to their environment, we can better predict how these populations will be affected as the conditions change."

The largest collection of footprints from the human fossil record in Africa is described in Scientific Reports this week. The findings, which further our understanding of human life during the Late Pleistocene period (126,000 to 11,700 years ago), suggest a division of labour in ancient human communities.

Kevin Hatala and colleagues uncovered 408 human footprints in Engare Sero, Tanzania after the site was discovered by members of a nearby Maasai community. The researchers dated the footprints to between 19,100 and 5,760 years ago. Based on their size, the distances between them and their orientations, the authors suggest that 17 tracks of footprints were created by a group of individuals moving together at walking speed in a southwesterly direction. The group was likely made up of 14 adult females, two adult males and one young male. The authors speculate that the females who made the tracks were foraging together and were visited or accompanied by the males, as this behaviour is observed in modern hunter-gatherers such as the Ache and Hadza. The findings may indicate a division of labour based on sex in ancient human communities.

For an additional six tracks of footprints oriented to the northeast, the authors estimate a broader range of variation in speed, which may suggest that they were not created by a single group travelling together, but by various individuals running and walking at different speeds.

The findings provide a snapshot of the movements and group behaviour of modern humans living in east Africa during the Late Pleistocene period.

An off-label experiment in mice using disulfiram, which has been used to treat alcohol use disorder for more than 50 years, consistently normalized body weight and reversed metabolic damage in obese middle-aged mice of both sexes. The international study was led by researchers at the National Institute on Aging (NIA), part of the National Institutes of Health . The results were published online in the journal Cell Metabolism on May 14.

The scientific team studied groups of 9-month-old lab mice who had been fed a high-fat diet for 12 weeks. As expected, this diet made the mice overweight and they started to show signs of pre-diabetes-like metabolic problems, such as insulin resistance and elevated fasting blood sugar levels. Next, the scientists divided these mice into four groups to be fed four different diets for an additional 12 weeks: a standard diet alone, a high-fat diet alone, a high-fat diet with a low amount of disulfiram, or a high-fat diet with a higher amount of disulfiram. As expected, the mice who stayed on the high-fat diet alone continued to gain weight and show metabolic problems. Mice who switched to standard diet alone gradually saw their body weight, fat composition and blood sugar levels return to normal.

The mice in the remaining two groups, with either a low or high dose of disulfiram added to their still-fatty food, showed a dramatic decrease in their weight and related metabolic damage. Mice on the high disulfiram dose lost as much as 40% of their body weight in just four weeks, effectively normalizing their weight to that of obese mice who were switched back to standard diet. Mice in either disulfiram dose diet group became leaner and showed significant improvement in blood glucose levels on par with the mice who were returned to standard diet. Disulfiram treatment, which has few harmful side effects in humans, also appeared to protect the pancreas and liver from damage caused by pre-diabetic type metabolic changes and fat build up usually caused by eating a high-fat diet.

The NIA scientists, Michel Bernier, Ph.D., and Rafael de Cabo, Ph.D., collaborate frequently with researchers at NIH and beyond on studies into how changes in dietary patterns like intermittent fasting could lead to cognitive and physical health benefits. They first became interested in disulfiram after reading about the benefits this class of drug has shown in treating type 2 diabetes in rats, coupled with the growing interest in repurposing drugs that may also improve healthy aging.

"When we first went down this path, we did not know what to expect, but once we started to see data showing dramatic weight loss and leaner body mass in the mice, we turned to each other and couldn't quite believe our eyes," Bernier said.

According to study's research team, the key to the positive results seem to stem from disulfiram's anti-inflammatory properties, which helped the mice avoid imbalances in fasting glucose and protected them from the damage of fatty diet and weight gain while improving metabolic efficiency. Both groups of obese mice (control and disulfiram) were not subjected to any form of exercise, nor did they demonstrate noticeable spontaneous behavioral changes. Based on the evidence they observed, the researchers believe the beneficial results of disulfiram stem solely from the drug. They did not observe any negative side effects from disulfiram in the mice.

The research team stresses that these results are based on animal studies, and they cannot be extrapolated to any potential benefits for human at this point. It is recommended that disulfiram not be used off-label for weight management outside of the context of clinical trials. Still, given the findings, they are planning future steps for studying disulfiram's potential, including a controlled clinical study to test if it could help individuals with morbid obesity lose weight, as well as deeper investigation into the drug's molecular mechanisms and potential for combining with other therapeutic interventions.

The research was supported by NIA through its intramural research program, NIA grants AG031782 and AG038072, in collaboration with colleagues from the National Institute of Alcohol Abuse and Alcoholism, Yale University, Albert Einstein College of Medicine, Korea Research Institute of Bioscience and Biotechnology, and University of Sydney, Australia.

This press release describes a basic research finding. Basic research increases our understanding of human behavior and biology, which is foundational to advancing new and better ways to prevent, diagnose and treat disease. Science is an unpredictable and incremental process-- each research advance builds on past discoveries, often in unexpected ways. Most clinical advances would not be possible without the knowledge of fundamental basic research.

A group of patients with diabetes were surveyed on their understanding of the consent process to have their medical data shared with digital platforms offering innovations to the management of their condition.

The current ability to share patient data between different practices, who each specialise in different aspects of the patients care, is a long process

However, the Dovetail digital consent application uses a mobile application and blockchain infrastructure to offer an IT technology, which facilitate sharing patient data and offer them the right to revoke consent

Patients found the Dovetail digital consent favourable, as they were empowered to manage their condition within an integrated care setting, whilst maintaining control over sharing of their data

Patients with diabetes often have to see many different stakeholders who each specialise in different aspects of their treatment. Researchers from WMG, University of Warwick surveyed patients on their understanding of how their data was shared, and found they would prefer to have it shared digitally using the Dovetail Digital consent application.

There are 4.7 million people in the UK live with diabetes, and will spend a lot of time visiting different specialist in different practices, who each specialise in some aspect of their treatment. Furthermore advances in digital technologies have resulted in innovative applications, which supported by healthcare professionals enable self-management, empowering patients to take control over aspects of their care. This requires a lot of data sharing, which is currently done by one practice requesting the medical records off another practice; with the need for doctors consent to share, this can be a long process to sign off. Furthermore, the process tends to be obscure with the patients forgetting the transfers for which they have given consent, as well not being very easy to revoke consent should the want so. The ability of patients to have control is one of the fundamental ethical and legal rights of the patient, and in many cases is difficult to balance against beneficial but data sharing intensive applications.

However, researchers from the Institute of Digital Healthcare (IDH) at WMG, University of Warwick propose that a new system called the Dovetail Digital consent application is favourable, and have analysed it in the paper; 'Evaluation of patient perception towards dynamic health data sharing using blockchain based digital consent with the Dovetail digital consent application: A cross sectional exploratory study', published in the journal Digital Health, SAGE Publications.

The Dovetail digital consent application is a robust, trusted and flexible mechanism for patients to offer their consent for their data to be shared between GP practices; they can also revoke consent at any point, therefore empowering them to manage their condition within an integrated care setting.

Dovetail sees a mobile application and blockchain-based infrastructure, meaning they can trace where their data has been shared. Blockchain is a state-of-the art technology originating in the financial industry, which has allowed implementing healthcare applications with the confidence and robustness found in the financial sector.

To survey whether it would work, IDH researchers asked 23 patients and 13 staff with diabetes, at a GP practice, to complete a series of questionnaires, followed by a focus group discussion, to determine their understanding of current methods to share data in a medical setting, and to see if they recall giving consent.

IDH Researchers then conducted a thematic analysis of the focus group transcripts and descriptive statistics of the questionnaires were performed.

Professor Theo Arvanitis, Director of the Institute of Digital Healthcare at WMG, University of Warwick explains what they found:

"We discovered there was a lack of understanding of existing consent processes in place, in fact many patients did not have any recollection of having previously given consent to their data being shared. When we asked them what they thought about the digital consent application patients overwhelmingly favoured the digital consent application over existing practice, as they recognised the value of the capability offered by the application."

Dr George Despotou, Associate Professor at the Institute of Digital Healthcare and lead in the study comments:

"The study participants welcomed an application that would ultimately contribute to improving their quality of case, whilst maintaining control over their data. In particular the study participants acknowledged the clarity of the consent application, and the ease with which they could review, as well as revoke existing consents. This was a very promising study on a technology that may be opening the way for highly innovative applications improving quality and efficiency of healthcare services, which patients would welcome, assured that ultimately they are in charge of their data."

IDH Researchers were able to conclude that the digital consent was received favourably as patients were able to recognise that it addresses the main limitations of the current process, but also acknowledged the traceability and transparency of the Dovetail app. Further research can now be conducted to see if patients across a wider demographic prefer the Dovetail Digital consent application, and if successful could revolutionise the way that patient data is stored and shared.

MINNEAPOLIS, MN- May 14, 2020 - In a vertical climb to avoid collision with a towering mountain, a plane ejects cargo to gain altitude. Investigators at the University of Minnesota showed that cancer cells perform similar feats in escaping the killing effects of radiation. Their work was published in the May issue of the journal, EBiomedicine.

Radiation is a key component of the standard-of-care treatment for the deadly brain cancer, glioblastoma; however, the treatment is rarely curative. While the growth of glioblastoma cells is often stalled by radiation, tumor growth inevitably resumes in nearly all treated patients.

"Understanding how cancer cells acquire resistance to radiation defines a pathway forward for how we can defeat this cancer," noted Clark C. Chen, MD, PhD, Lyle French Chair in Neurosurgery and head of the Department of Neurosurgery at the University of Minnesota Medical School.

To understand how glioblastomas become resistant to radiation, the research team led by Chen collected clinical glioblastoma samples from patients prior to and after radiation treatment and compared the levels of microRNAs. MicroRNA is a class of small RNA cells that control how much protein a cell makes, which ultimately determines how the cell functions.

"MicroRNA plays such a key role in cell fate that its discovery was awarded the Nobel Prize in Physiology or Medicine in 2006," said Beibei Xu, PhD, Department of Neurosurgery, who is first author of the paper.

While levels of most microRNAs remain unchanged in response to radiation treatment, Chen's team identified a small subset, most notably a microRNA named miR-603, that decreased after radiation. Using a number of experimental models, the team subsequently showed that glioblastoma cells, like a plane dumping cargo in a vertical ascent, jettison miR-603 in response to radiation treatment. As a result, glioblastoma cells increase the production of proteins that render them insensitive to radiation.

"The cancer cells package miR-603 into vesicles called exosomes or extracellular vesicles. These vesicles facilitate communication between cells," Xu explained. "We have long appreciated that these vesicles have profound effects on recipient cells. Our study is one of the first to demonstrate that secretion of microRNAs, through these vesicles, influences the behavior of the secreting cell."

The findings of this study suggest a new therapeutic strategy that may move researchers one step closer to a cure for glioblastoma. "If we introduce a large amount of miR-603 to overwhelm the ability of the cancer cells to export them, we increase the tumor-killing effects of radiation," Chen said. "Such delivery can be achieved through gene therapy or nanoparticle platforms. We are working quickly to develop these agents for use during a clinical trial in the near future."

BIRMINGHAM, Ala. - Many heart diseases are linked to oxidative stress, an overabundance of reactive oxygen species. The body reacts to reduce oxidative stress -- where the redox teeter-totter has gone too far up -- through production of endogenous antioxidants that reduce the reactive oxygen species. This balancing act is called redox homeostasis.

But what happens if the redox teeter-totter goes too far down, creating antioxidative stress, also known as reductive stress? Rajasekaran Namakkal-Soorappan, Ph.D., associate professor in the University of Alabama at Birmingham Department of Pathology, and colleagues have found that reductive stress, or RS/AS, is also pathological. This discovery, they say, may have clinical importance in management of heart failure.

They report that RS causes pathological heart enlargement and diastolic dysfunction in a mouse model. This study, published in the journal Antioxidants and Redox Signaling, was led by Namakkal-Soorappan and Pei Ping, Ph.D., David Geffen School of Medicine at the University of California-Los Angeles.

"Antioxidant-based therapeutic approaches for human heart failure should consider a thorough evaluation of antioxidant levels before the treatment," they said. "Our findings demonstrate that chronic RS is intolerable and adequate to induce heart failure."

The study used transgenic mice that had upregulated genes for antioxidants in the heart, which increased the amounts of antioxidant proteins and reduced glutathione, creating RS. One mouse line had low upregulation, and one had high upregulation, creating chronic low RS and chronic high RS, respectively, in the hearts of the mice.

The mice with high RS showed pathological heart changes called hypertrophic cardiomyopathy, and had an abnormally high heart ejection fraction and diastolic dysfunction at 6 months of age. Sixty percent of the high-RS mice died by 18 months of age.

The mice with low RS had normal survival rates, but they developed the heart changes at about 15 months of age, suggesting that even moderate RS can lead to irreversible damage in the heart over time.

Giving high-RS mice a chemical that blocked biosynthesis of glutathione, beginning at about 6 weeks of age, prevented RS and rescued the mice from pathological heart changes.

Gobinath Shanmugam, Ph.D., postdoctoral fellow in the UAB Department of Pathology, and Namakkal-Soorappan point out that a 2019 survey found about 77 percent of Americans are consuming dietary supplements every day, and within this group, about 58 percent are consuming antioxidants as multivitamins. Thus, a chronic consumption of antioxidant drugs by any individual without knowing their redox state might result in RS, which can induce pathology and slowly damage the heart.

Effect of RS on skeletal muscle

In a related study, published in the journal Redox Biology, Namakkal-Soorappan looked at the impact of RS on myosatellite cells, which are also known as muscle stem cells. These cells, located near skeletal muscle fibers, are able to regenerate and differentiate into skeletal muscle after acute or chronic muscle injury. The regulation of myosatellite cells is of interest given the loss of skeletal muscle mass during aging or in chronic conditions like diabetes and AIDS.

Recently, Namakkal-Soorappan reported that tilting the redox teeter-totter to oxidative stress impaired regeneration of skeletal muscle. Now, in the Redox Biology paper, he has shown that tilting the redox to RS also causes significant inhibition of muscle satellite cell differentiation.

Rather than genetic manipulation to induce RS, as was done in the heart study, the researchers used the chemical sulforaphane or direct augmentation of intracellular glutathione to induce RS in cultured mouse myoblast cells. Both treatments inhibited myoblast differentiation. Finally, authors attempted to withdraw antioxidative stress by growing cells in medium without sulforaphane, which removes the RS and accelerates the differentiation. Namakkal-Soorappan and colleagues found that a pro-oxidative milieu, through a mild generation of reactive oxygen species, was required for myoblast differentiation.

The researchers also showed that genetic silencing of a negative regulator of the antioxidant genes also inhibited myoblast differentiation.