Tech

Two-dimensional solar materials may offer a way to extract more energy from sunlight. By tuning the structure of a 2D perovskite solar material, researchers from KAUST and the Georgia Institute of Technology have shown they can prolong the lifetime of highly energetic hot carriers generated by light striking the material. The approach could offer a way to capture solar energy more efficiently.

Hybrid organic-inorganic perovskites are attractive solar materials because they are potentially much less expensive to produce than silicon. However, there remain questions over perovskites' long-term stability.

"As an alternative to 3D hybrid perovskites, 2D hybrid perovskites have improved stability and moisture resistance," says Jun Yin, a member of Omar Mohammed's and Osman Bakr's research groups. However, hot carrier cooling in these materials has not been extensively studied, adds Partha Maity, a postdoctoral fellow on the KAUST team.

Hot carriers form due to the wide range of energies of sunlight, which ranges from low-energy infrared and red light at one end of the spectrum, to violet and ultraviolet at the high-energy end. Solar panels capture energy when incoming light bumps an electron into an excited state, but even red light can excite an electron into a conductive band. Higher energy light can generate super-excited hot carriers, but they shed their extra energy much faster than conventional solar materials can capture them.

Mohammed and the team examined whether changing the organic component of hybrid 2D perovskites could slow hot carrier cooling, enabling all their energy to be captured.

Using ultrafast laser spectroscopy, they examined lead iodide perovskite materials with three different organic components: ethanolamine (EA), aminopropanol (AP) and phenylethylamine (PEA). "Ultrafast spectroscopy is a very powerful and convenient approach to directly track hot carrier relaxation," Mohammed says. "We can follow their ultrafast dynamics in real time."

The team saw a significant difference between the three different materials. "We found that the (EA)2PbI4 single crystal underwent a much slower hot carrier cooling process," Yin says. Aided by molecular dynamics simulations, the team showed that the EA-based structure suppressed a range of mechanisms by which hot carriers usually lose energy to the surrounding perovskite structure.

"Since we learned from this study how to slow the hot carrier dynamics in 2D perovskites, we will now focus on the extraction of these carriers in a real solar cell architecture and on their possible contribution to overall conversion efficiency," Mohammed says. The team will also examine hot carrier dynamics and extraction in 2D perovskites with different compositions, he adds.

PITTSBURGH, December 27, 2019 - Teenage boys who witness their peers abusing women and girls are much more likely to bully and fight with others, as well as behave abusively toward their dates, compared to teenage boys who don't witness such behaviors, according to an analysis led by the University of Pittsburgh School of Medicine and UPMC Children's Hospital of Pittsburgh.

Conversely, the study found that adolescents with more equitable gender attitudes - those who felt boys and girls deserve equal opportunities and respect - had lower odds of reporting violent behaviors. The results are published today in the American Journal of Preventive Medicine.

"The Me Too Movement brought to light how pervasive sexual violence and derogatory behavior toward women is in our society," said lead author Elizabeth Miller, M.D., Ph.D., professor of pediatrics, public health and clinical and translational science at Pitt. "Our findings highlight the wide-ranging impact that witnessing sexual harassment and dating violence has on our teenage boys, and present an opportunity to teach adolescents to challenge negative gender and social norms, and interrupt their peer's disrespectful and harmful behaviors."

This study is the first to gather information from U.S. male adolescents in community-based settings, rather than schools or clinics, about multiple types of violence, including bullying and sexual harassment, and the role of gender norms and peer behaviors.

Miller and her team surveyed 866 13- to 19-year-old boys at after-school programs, libraries, churches and other youth-serving organizations in 20 lower-resource Pittsburgh neighborhoods. The teens completed the surveys anonymously between August 2015 and June 2017 as part of a larger study evaluating the effect of a prevention program to reduce sexual violence. Seventy percent of the teens identified as African American and 21% as Hispanic, multiracial or 'other.'

Of the 619 boys who had ever dated, 1 in 3 reported using abusive behavior toward someone they were dating in the previous 9 months. Sexual harassment, whether dating or not, was also common, with 485, or 56%, saying they'd engaged in such behavior. And 587, or 68% of the respondents, said they'd been in physical fights, or threatened or injured someone with a weapon.

Boys who said they'd witnessed their peers engaging in two or more of nine different harmful verbal, physical or sexual behaviors toward women and girls - such as making rude or disrespectful comments about a girl's body - had 2 to 5 times higher odds of engaging in a variety of violent behaviors, some having nothing to do with women or dating.

"This reinforces that pressure to conform to stereotypes about masculinity that perpetuate harmful behaviors toward women and girls is also associated with getting in a fight with another guy," said Miller, who is also director of the Division of Adolescent and Young Adult Medicine at UPMC Children's. "These behaviors aren't happening in silos - if we're going to stop one, we need to also be addressing the other."

Interestingly, the research team did not find that teens who reported having more gender equitable attitudes were any less likely to engage in homophobic teasing, something three-quarters of the survey respondents endorsed.

"It's a puzzling and troubling finding. We believe it may be because these teens have normalized homophobic teasing - it is so commonplace, they may see it as a form of acceptable, possibly even pro-social, interaction with their peers," said Alison Culyba, M.D., Ph.D., M.P.H., assistant professor of pediatrics in the Division of Adolescent and Young Adult Medicine at UPMC Children's. "This study illustrates the need for cross-cutting prevention strategies that address multiple aspects of youth violence."

As part of their study, this team of researchers are evaluating a sexual violence prevention program called Manhood 2.0. Miller has also conducted research on a program called Coaching Boys into Men that guides middle and high school coaches in talking with their male athletes about stopping violence against women and girls. Both Manhood 2.0 and Coaching Boys into Men involve reinforcing more equitable gender attitudes and increasing the number of youth who intervene when witnessing peers' disrespectful behavior.

During the past years, artificial intelligence (AI) -- the capability of a machine to mimic human behavior -- has become a key player in high-techs like drug development projects. AI tools help scientists to uncover the secret behind the big biological data using optimized computational algorithms. AI methods such as deep neural network improves decision making in biological and chemical applications i.e., prediction of disease-associated proteins, discovery of novel biomarkers and de novo design of small molecule drug leads. These state-of-the-art approaches help scientists to develop a potential drug more efficiently and economically.

A research team led by Professor Hongzhe Sun from the Department of Chemistry at the University of Hong Kong (HKU), in collaboration with Professor Junwen Wang from Mayo Clinic, Arizona in the United States (a former HKU colleague), implemented a robust deep learning approach to predict disease-associated mutations of the metal-binding sites in a protein. This is the first deep learning approach for the prediction of disease-associated metal-relevant site mutations in metalloproteins, providing a new platform to tackle human diseases. The research findings were recently published in a top scientific journal Nature Machine Intelligence.

Metal ions play pivotal roles either structurally or functionally in the (patho)physiology of human biological systems. Metals such as zinc, iron and copper are essential for all lives and their concentration in cells must be strictly regulated. A deficiency or an excess of these physiological metal ions can cause severe disease in humans. It was discovered that a mutation in human genome are strongly associated with different diseases. If these mutations happen in the coding region of DNA, it might disrupt metal-binding sites of the proteins and consequently initiate severe diseases in humans. Understanding of disease-associated mutations at the metal-binding sites of proteins will facilitate discovery of new drugs.

The team first integrated omics data from different databases to build a comprehensive training dataset. By looking at the statistics from the collected data, the team found that different metals have different disease associations. A mutation in zinc-binding sites has a major role in breast, liver, kidney, immune system and prostate diseases. By contrast, the mutations in calcium- and magnesium-binding sites are associated with muscular and immune system diseases, respectively. For iron-binding sites, mutations are more associated with metabolic diseases. Furthermore, mutations of manganese- and copper-binding sites are associated with cardiovascular diseases with the latter being associated with nervous system disease as well. They used a novel approach to extract spatial features from the metal binding sites using an energy-based affinity grid map. These spatial features have been merged with physicochemical sequential features to train the model. The final results show using the spatial features enhanced the performance of the prediction with an area under the curve (AUC) of 0.90 and an accuracy of 0.82. Given the limited advanced techniques and platforms in the field of metallomics and metalloproteins, the proposed deep learning approach offers a method to integrate the experimental data with bioinformatics analysis. The approach will help scientist to predict DNA mutations which are associated with disease like cancer, cardiovascular diseases and genetic disorders.

Professor Sun said: "Machine learning and AI play important roles in the current biological and chemical science. In my group we worked on metals in biology and medicine using integrative omics approach including metallomics and metalloproteomics, and we already produced a large amount of valuable data using in vivo/vitro experiments. We now develop an artificial intelligence approach based on deep learning to turn these raw data to valuable knowledge, leading to uncover secrets behind the diseases and to fight with them. I believe this novel deep learning approach can be used in other projects, which is undergoing in our laboratory."

A group of researchers from the Skoltech Center for Computational and Data-Intensive Science and Engineering (CDISE) took 4th place in the international MRI-based adolescent intelligence prediction competition. For the first time ever, the Skoltech scientists used ensemble methods based on deep learning 3D networks to deal with this challenging prediction task. The results of their study were published in the journal Adolescent Brain Cognitive Development Neurocognitive Prediction.

In 2013, the US National Institutes of Health (NIH) launched the first grand-scale study of its kind in adolescent brain research, Adolescent Brain Cognitive Development (ABCD, https://abcdstudy.org/), to see if and how teenagers' hobbies and habits affect their further brain development.

Magnetic Resonance Imaging (MRI) is a common technique used to obtain images of human internal organs and tissues. Scientists wondered whether the intelligence level can be predicted from an MRI brain image. The NIH database contains a total of over 11,000 structural and functional MRI images of children aged 9-10.

NIH scientists launched an international competition, making the enormous NIH database available to a broad community for the first time ever. The participants were given a task of building a predictive model based on brain images. As part of the competition, the Skoltech team applied neural networks for MRI image processing. To do this, they built a network architecture enabling several mathematical models to be applied to the same data in order to increase the prediction accuracy, and used a novel ensemble method to analyze the MRI data.

In their recent study, Skoltech researchers focused on predicting the intelligence level, or the so called "fluid intelligence", which characterizes the biological abilities of the nervous system and has little to do with acquired knowledge or skills. Importantly, they made predictions for both the fluid intelligence level and the target variable independent from age, gender, brain size or MRI scanner used.

"Our team develops deep learning methods for computer vision tasks in MRI data analysis, amongst other things. In this study, we applied ensembles of classifiers to 3D of super precision neural networks: with this approach, one can classify an image as it is, without first reducing its dimension and, therefore, without losing valuable information," explains CDISE PhD student, Ekaterina Kondratyeva.

The results of the study helped find the correlation between the child's "fluid intelligence" and brain anatomy. Although the prediction accuracy is less than perfect, the models produced during this competition will help shed light on various aspects of cognitive, social, emotional and physical development of adolescents. This line of research will definitely continue to expand.

The Skoltech team was invited to present their new method at one of the world's most prestigious medical imaging conferences, MICCAI 2019, in Shenzhen, China.

NASA-NOAA's Suomi NPP satellite provided a visible image of Phanfone as it continues moving through the South China Sea. Visible imagery showed that the storm is less organized and elongated as the storm weakened from a typhoon to a tropical storm.

Satellite imagery gives forecasters a look at the structure and strength of tropical cyclones. Visible imagery helps forecasters understand if a storm is organizing or weakening. If a storm appears more circular in nature it is an indication the storm is consolidating and strengthening. If a storm appears more elongated or asymmetrical, it is a sign that the storm is weakening.
In the visible image captured by Suomi NPP's Visible Infrared Imaging Radiometer Suite (VIIRS) instrument, Phanfone appeared more asymmetrical.

Forecasters at the Joint Typhoon Warning Center in Pearl Harbor, Hawaii noted that Phanfone is being affected by vertical wind shear, which is a factor in elongating the storm. Wind shear are winds around the storm that blow against it at different levels in the atmosphere. The storm is also being weakened by dry air moving into it from the west. Dry air saps the ability for thunderstorms to form, and thunderstorms make up a tropical cyclone.

At 10 a.m. EST (1500 UTC) on Dec. 27, Phanfone's maximum sustained winds had dropped to 50 knots. It was located in the South China Sea, near 15.0 degrees north latitude and 115.9 degrees east longitude. That is approximately 461 nautical miles east of Da Nang, Vietnam.

Phanfone is moving across the South China Sea in a westerly direction and is continuing to weaken. The forecasters at the Joint Typhoon Warning Center expect the storm to dissipate by Dec. 29, just off the coast of Vietnam.

Tropical cyclones are the most powerful weather event on Earth. NASA's expertise in space and scientific exploration contributes to essential services provided to the American people by other federal agencies, such as hurricane weather forecasting.

NASA analyzed the cloud top temperatures in Tropical Storm Sarai using infrared light to determine the strength of the storm. Sarai has triggered warnings for Fiji and Tonga in the Southern Pacific Ocean,

On Dec. 27, there are regional warnings in effect for Fiji and Tonga. In Fiji, there is a storm warning is in force for Vatulele and Kadavu. A gale warning is in force for Vanua Levu, Taveuni, Yasawa and the Mamanuca Group, Kadavu, Lomaiviti Group, Viti Levu and nearby smaller islands. Tonga is on tropical cyclone alert

One of the ways NASA researches tropical cyclones is using infrared data that provides temperature information. Cloud top temperatures identify where the strongest storms are located. The stronger the storms, the higher they extend into the troposphere, and they have the colder cloud temperatures.

On Dec. 27 at 0135 UTC (Dec. 26 at 8:35 p.m. EST) NASA's Aqua satellite analyzed the storm using the Atmospheric Infrared Sounder or AIRS instrument. The AIRS imagery showed the strongest storms circling the center of circulation, just west of Fiji and in a thick band of thunderstorms northeast of Fiji. In those areas, AIRS found coldest cloud top temperatures as cold as or colder 210 Kelvin minus 81 degrees Fahrenheit (minus 63.1 degrees Celsius). NASA research has shown that cloud top temperatures that cold indicate strong storms that have the capability to create heavy rain.

Tropical cyclones do not always have uniform strength, and some sides have stronger sides than others, so knowing where the strongest sides of the storms are located helps forecasters. NASA then provides data to tropical cyclone meteorologists so they can incorporate it in their forecasts.

At 10 a.m. EST (1500 UTC) on Dec.27 the Joint Typhoon Warning Center or JTWC noted that the center of Tropical cyclone Sarai was located near 18.7 degrees south latitude and 176.1 degrees east longitude. That is about 136 nautical miles west-southwest of Suva, Fiji. Maximum sustained winds were near 55 knots (63 mph/102 kph) and the storm was strengthening. It was moving to the south and expected to turn east.

Sarai is forecast to move toward the east. The storm is expected to strengthen briefly to 65 knots on closest approach to the main Fijian islands, but weaken as it nears Tonga.

Typhoons and hurricanes are the most powerful weather event on Earth. NASA's expertise in space and scientific exploration contributes to essential services provided to the American people by other federal agencies, such as hurricane weather forecasting.

The AIRS instrument is one of six instruments flying on board NASA's Aqua satellite, launched on May 4, 2002.

Macular degeneration (AMD) causes blindness in millions of people in the Western world. It is the most common cause of severe vision loss in the Western world among those aged 50 and over, and its prevalence increases with age. Though there is no cure for AMD, significant recent advancements in artificial retina implants may lead to effective treatment.

Located inside the eye the retina contains light receptors (photoreceptors) which absorb light. Information is then processed and transmitted to the brain. The macula, the central area of the retina, processes most of the information that reaches the brain from the eye, enabling one to see while reading and driving, facial recognition, and any other activity that requires accurate vision. In the peripheral retina, the area of the retina outside the macula that assists mainly with spatial judgment, vision is 10-20 times less precise. In AMD precise vision is impaired due to damage to the center of the retina, while peripheral vision remains normal.

When there is damage to the photoreceptor layers in the retina, an artificial retina -- a device built from tiny electrodes smaller in width than a hair -- may be implanted. Activating these electrodes results in electrical stimulation of the remaining retinal cells and results in visual restoration, albeit partially. AMD patients implanted with an artificial retina possess a combination of artificial central vision and normal peripheral vision. This combination of artificial and natural vision is important to study in order to understand how to help the blind. One of the critical questions in this regard is whether the brain can integrate artificial and natural vision properly.

In a new study published in the journal Current Biology, researchers from Bar-Ilan University and Stanford University report for the first time the discovery of evidence indicating that the brain knows how to integrate natural and artificial vision, while maintaining processing information that is important for vision. "We used a unique projection system which stimulated either natural vision, artificial vision or a combination of natural and artificial vision, while simultaneously recording the cortical responses in rodents implanted with a subretinal implant," said Tamar Arens-Arad, who conducted the experiments as part of her doctoral studies. The implant is composed of dozens of tiny solar cells and electrodes, developed by Prof. Daniel Palanker at Stanford University.

"These pioneering results have implications for better restoration of sight in AMD patients implanted with retinal prosthetic devices and support our hypothesis that prosthetic and natural vision can be integrated in the brain. The results could also have implications for future brain-machine interface applications where artificial and natural processes co-exist," said Prof. Yossi Mandel, Head of Bar-Ilan University's Ophthalmic Science and Engineering Lab and the study's lead author.

The research was carried out in Prof. Mandel's lab at the School of Optometry and Vision Science, Mina and Everard Goodman Faculty of Life Sciences and the Institute of Nanotechnology and Advanced Materials (BINA) at Bar-Ilan University's, in collaboration with Prof. Palanker of Stanford University. The study was conducted by Tamar Arens-Arad in collaboration with Dr. Nairouz Farah, Rivkah Lender, Avital Moshkovitz and Thomas Flores.

Scientists from Far Eastern Federal University (FEFU) teamed up with colleagues from Institute of Chemistry (FEB RAS), Institute for Single Crystals (Ukraine), and Shanghai Institute of Ceramics (Chinese Academy of Sciences) to develop Y2O3?MgO nanocomposite ceramics with uniform distribution of two phases, microhardness over 11 GPa, and average grain size of 250 nm. It capable of transmitting over 70% of IR-range with wavelength up to 6,000 nm. A related article was published in Ceramics International.

Due to the submicron size of the grains and their even distribution in the whole volume of the material, the yttrium oxide and magnesium oxide (Y2O3?MgO) ceramics possesses advanced optical, thermophysical, and mechanical properties (thermal stability, thermal conductivity, hardness, etc.) and surpasses its single-phase commercial analogs Y2O3 and MgO by these parameters. The team managed to achieve such advanced characteristics thanks to an innovative method - spark plasma sintering of yttrium and magnesium oxide nanopowders. This method is being actively developed at FEFU and the Institute of Chemistry (FEB RAS).

The new material can be used in modern high tech production processes, for example, to manufacture shielding windows for IR systems in aerospace engineering.

"To develop the Y2O3?MgO nanoceramics with uniform distribution of two phases, our colleagues had to solve a complex problem of even distribution of particle contact points in Y2O3 and MgO nanopowders. To do so, they used the method of self-propagating glycine-nitrate synthesis with the excess of glycine and nitric acid. Due to the use of reaction systems with the excess of glycine, a large quantity of nucleation centers was generated within a short time in the course of composite nanopowders synthesis, and the uniformity of Y2O3 and MgO nanoparticle sizes was reached. Large volumes of gases emitted in the course of the reaction secured the isolation of the particles and prevented aggregation. Under these conditions the consolidation of the powders took place mainly because of plastic deformation without grain boundary sliding, turning, and further coalescence of the grains. Temperature differences in the whole volume of the compact were reduced to the minimum in the course of sintering," said Denis Kosyanov, the head of the research team at FEFU, and a senior researcher at the Center for the National Technological Initiative, FEFU.

According to the scientist, Y2O3?MgO ceramic nanocomposites have been actively studied all over the world for only a couple of years. They are considered promising materials for operations in the IR range and are known for increased mechanical and thermal stability.

The new material has staggered structure with 1:1 phase volume ratio. Its average grain size is 250 nm, and microhardness is over 11 GPa. The ceramics transmits over 70% of light in the IR range with wavelength up to 6,000 nm.

The material was manufactured from Y2O3 and MgO nanopowders with controlled particle sizes. The powders were compacted using a fast consolidation method called spark plasma sintering. The procedure took 8 minutes and was carried out at the temperature of 1,300°? and under the pressure of 60 MPa. This method helped the scientists suppress diffusion mass transfer and prevent the growth of the grains beyond the critical size (~400 nm).

"The IR transparency of Y2O3-MgO nanocomposites increases with the increasing of sintering temperatures, and top values are reached at 1,300-1,350°?. This is due to the increase of sample density, grain growth, and the reduction of grain boundary length. At higher sintering temperatures the balance of the system shifts, the staggered structure of the Y2O3 and MgO grains is broken, and the so-called abnormal grain growth takes place," concluded Denis Kosyanov.

FEFU runs a Materials priority project and a Center for National Technological Initiatives in Neurotechnologies, VR, and AR Technologies (grant No. 1/1251/2018 dated October 16, 2018). The researchers working in these areas develop scientific and technical bases for multifunctional ceramic materials to be used in microelectronics, lighting technologies, and radiochemistry.

Scientists at Tokyo Institute of Technology(Tokyo Tech) explore a new material combination that sets the stage for magnetic random access memories, which rely on spin--an intrinsic property of electrons-- and could outperform current storage devices. Their breakthrough published in a new study describes a novel strategy to exploit spin-related phenomena in topological materials, which could spur several advances in the field of spin electronics. Moreover, this study provides additional insight into the underlying mechanism of spin-related phenomena.

Spintronics is a modern technological field where the "spin" or the angular momentum of electrons takes a primary role in the functioning of electronic devices. In fact, collective spin arrangements are the reason for the curious properties of magnetic materials, which are popularly used in modern electronics. Researchers globally have been trying to manipulate spin-related properties in certain materials, owing to a myriad of applications in devices that work on this phenomenon, especially in non-volatile memories. These magnetic non-volatile memories, called MRAM, have the potential to outperform current semiconductor memories in terms of power consumption and speed.

A team of researchers from Tokyo Tech, led by Assoc. Prof. Pham Nam Hai, recently published a study in Journal of Applied Physics on unidirectional spin Hall magnetoresistance (USMR), a spin-related phenomenon that could be used to develop MRAM cells with an extremely simple structure. The spin Hall effect leads to the accumulation of electrons with a certain spin on the lateral sides of a material. The motivation behind this study was that the spin Hall effect, which is particularly strong in materials known as "topological insulators", can results in a giant USMR by combining a topological insulator with a ferromagnetic semiconductor.

Basically, when electrons with the same spin accumulate on the interface between the two materials, (Fig. 1) due to the spin Hall effect, the spins can be injected to the ferromagnetic layer and flip its magnetization, allowing for "memory write operations", which means the data in storage devices can be "re-written". At the same time, the resistance of the composite structure changes with the direction of the magnetization owing to the USMR effect. Because resistance can be measured using an external circuit, this allows for "memory read operations", in which data can be read using the same current path with the write operation. In existing material combination using conventional heavy metals for the spin Hall effect, however, the changes in resistance caused by the USMR effect are extremely low--well below 1%--which hinders the development of MRAMs utilizing this effect. In addition, the mechanism of the USMR effect seems to vary according to the combination of material used, and it is not clear which mechanism can be exploited for enhancing the USMR to over 1%.

To understand how material combinations can influence the USMR effect, the researchers designed a composite structure comprising a layer of gallium manganese arsenide (GaMnAs, a ferromagnetic semiconductor) and bismuth antimonide (BiSb, a topological insulator). Interestingly, with this combination, they were successful in obtaining a giant USMR ratio of 1.1%. In particular, the results showed that utilizing phenomena called "magnon scattering" and "spin-disorder scattering" in ferromagnetic semiconductors can lead to a giant USMR ratio, making it possible to use this phenomenon in real-world applications. Dr. Hai elaborates, "Our study is the first to demonstrate that it is possible to obtain an USMR ratio larger than 1%. This is several orders of magnitude higher than those using heavy metals for USMR. In addition, our results provide a new strategy to maximize the USMR ratio for practical device applications".

This study could play a key role in the development of spintronics. Conventional MRAM structure requires about 30 ultrathin layers, which is very challenging to make. By utilizing USMR for read-out operation, only two layers are needed for the memory cells. "Further material engineering may further improve the USMR ratio, which is essential for USMR-based MRAMs with an extremely simple structure and fast reading. Our demonstration of an USMR ratio over 1% is an important step toward this goal," concludes Dr. Hai.

Researchers led by Professor MATSUYAMA Hideto and Professor YOSHIOKA Tomohisa at Kobe University's Research Center for Membrane and Film Technology have succeeded in developing an ultrathin membrane with a fouling-resistant silica surface treatment for high performance separation of oil from water.

Furthermore, this membrane was shown to be versatile; it was able to separate water from a wide variety of different oily substances.

These results were published online in the Journal of Materials Chemistry A on October 3 2019.

Introduction

The development of technology to separate oil from water is crucial for dealing with oil spills and water pollution generated by various industries. By 2025, it is predicted that two thirds of the world's population won't have sufficient access to clean water. Therefore the development of technologies to filter oily emulsions and thus increase the amount of available clean water is gaining increasing attention.

Compared with traditional purification methods including centrifugation and chemical coagulation, membrane separation has been proposed as a low cost, energy efficient alternative. Although this technology has been greatly developed, most membranes suffer from fouling issues whereby droplets of oil get irreversibly absorbed onto the surface. This leads to membrane pore blocking, subsequently reducing its lifespan and efficiency.

One method of mitigating the fouling issues is to add surface treatments to the membrane. However, many experiments with this method have encountered problems such as changes in the original surface structure and the deterioration of the treated surface layer by strong acid, alkaline and salt solutions. These issues limit the practical applications of such membranes in the harsh conditions during wastewater treatment.

Research Methodology

In this study, researchers succeeded in developing a membrane consisting of a porous polyketone (PK) support with a 10 nano-meter thick silica layer applied on the top surface (Figure 1). This silica layer was formed onto the PK fibrils using electrostatic attraction- the negatively charged silica was attracted to the positively charged PK.

The PK membrane has a high water permeance due to its large pores and high porosity. The silicification process- the addition of silica on the PK fibrils- provides a strong oil-repellant coating to protect the surface modified membrane from fouling issues.

Another advantage of this membrane is that it requires no large pressure application to achieve high water penetration. The membrane exhibited water permeation by gravity- even when a water level as low as 10cm (with a pressure of approx. 0.01atm) was utilized. In addition, the developed membrane was able to reject 99.9% of oil droplets- including those with a size of 10 nanometers. By using this membrane with an area of 1m2, 6000 liters of wastewater can be treated in one hour under an applied pressure of 1atm. It was also shown to be effective at separating water from various different oily emulsions (Figure 2).

As mentioned, the silification provided a strong oil repellant coating. Through the experiments carried out on the membrane to test its durability against fouling, it was discovered that oil did not become adsorbed onto the surface and that the oil droplets could be easily cleaned off (Figure 3). This membrane showed great tolerance against a variety of acidic, alkaline, solvent and salt solutions.

Conclusion

The ultrathin membrane developed by this research group has demonstrated efficient separation of water from oily emulsions, in addition to anti-fouling resistance. Technology to separate emulsions is indispensable in the fight against water pollution and clean water shortages. It is hoped that this development could be utilized in the treatment of industry waste water.

For many people, the New Year is a time to adopt new habits as a renewed commitment to personal health. Newly enthusiastic fitness buffs pack into gyms and grocery stores are filled with shoppers eager to try out new diets.

But, does scientific evidence support the claims made for these diets? In a review article published in the Dec. 26 issue of The New England Journal of Medicine, Johns Hopkins Medicine neuroscientist Mark Mattson, Ph.D., concludes that intermittent fasting does.

Mattson, who has studied the health impact of intermittent fasting for 25 years, and adopted it himself about 20 years ago, writes that "intermittent fasting could be part of a healthy lifestyle." A professor of neuroscience at the Johns Hopkins University School of Medicine, Mattson says his new article is intended to help clarify the science and clinical applications of intermittent fasting in ways that may help physicians guide patients who want to try it.

Intermittent fasting diets, he says, fall generally into two categories: daily time-restricted feeding, which narrows eating times to 6-8 hours per day, and so-called 5:2 intermittent fasting, in which people limit themselves to one moderate-sized meal two days each week.

An array of animal and some human studies have shown that alternating between times of fasting and eating supports cellular health, probably by triggering an age-old adaptation to periods of food scarcity called metabolic switching. Such a switch occurs when cells use up their stores of rapidly accessible, sugar-based fuel, and begin converting fat into energy in a slower metabolic process.

Mattson says studies have shown that this switch improves blood sugar regulation, increases resistance to stress and suppresses inflammation. Because most Americans eat three meals plus snacks each day, they do not experience the switch, or the suggested benefits.

In the article, Mattson notes that four studies in both animals and people found intermittent fasting also decreased blood pressure, blood lipid levels and resting heart rates.

Evidence is also mounting that intermittent fasting can modify risk factors associated with obesity and diabetes, says Mattson. Two studies at the University Hospital of South Manchester NHS Foundation Trust of 100 overweight women showed that those on the 5:2 intermittent fasting diet lost the same amount of weight as women who restricted calories, but did better on measures of insulin sensitivity and reduced belly fat than those in the calorie-reduction group.

More recently, Mattson says, preliminary studies suggest that intermittent fasting could benefit brain health too. A multicenter clinical trial at the University of Toronto in April found that 220 healthy, nonobese adults who maintained a calorie restricted diet for two years showed signs of improved memory in a battery of cognitive tests. While far more research needs to be done to prove any effects of intermittent fasting on learning and memory, Mattson says if that proof is found, the fasting -- or a pharmaceutical equivalent that mimics it -- may offer interventions that can stave off neurodegeneration and dementia.

"We are at a transition point where we could soon consider adding information about intermittent fasting to medical school curricula alongside standard advice about healthy diets and exercise," he says.

Mattson acknowledges that researchers do "not fully understand the specific mechanisms of metabolic switching and that "some people are unable or unwilling to adhere" to the fasting regimens. But he argues that with guidance and some patience, most people can incorporate them into their lives. It takes some time for the body to adjust to intermittent fasting, and to get beyond initial hunger pangs and irritability that accompany it. "Patients should be advised that feeling hungry and irritable is common initially and usually passes after two weeks to a month as the body and brain become accustomed to the new habit," Mattson says.

To manage this hurdle, Mattson suggests that physicians advise patients to gradually increase the duration and frequency of the fasting periods over the course of several months, instead of "going cold turkey." As with all lifestyle changes, says Mattson, it's important for physicians to know the science so they can communicate potential benefits, harms and challenges, and offer support.

Imagine a world where people could only talk to their next-door neighbor, and messages must be passed house to house to reach far destinations.

Until now, this has been the situation for the bits of hardware that make up a silicon quantum computer, a type of quantum computer with the potential to be cheaper and more versatile than today's versions.

Now a team based at Princeton University has overcome this limitation and demonstrated that two quantum-computing components, known as silicon "spin" qubits, can interact even when spaced relatively far apart on a computer chip. The study was published in the journal Nature.

"The ability to transmit messages across this distance on a silicon chip unlocks new capabilities for our quantum hardware," said Jason Petta, the Eugene Higgins Professor of Physics at Princeton and leader of the study. "The eventual goal is to have multiple quantum bits arranged in a two-dimensional grid that can perform even more complex calculations. The study should help in the long term to improve communication of qubits on a chip as well as from one chip to another."

Quantum computers have the potential to tackle challenges beyond the capabilities of everyday computers, such as factoring large numbers. A quantum bit, or qubit, can process far more information than an everyday computer bit because, whereas each classical computer bit can have a value of 0 or 1, a quantum bit can represent a range of values between 0 and 1 simultaneously.

To realize quantum computing's promise, these futuristic computers will require tens of thousands of qubits that can communicate with each other. Today's prototype quantum computers from Google, IBM and other companies contain tens of qubits made from a technology involving superconducting circuits, but many technologists view silicon-based qubits as more promising in the long run.

Silicon spin qubits have several advantages over superconducting qubits. The silicon spin qubits retain their quantum state longer than competing qubit technologies. The widespread use of silicon for everyday computers means that silicon-based qubits could be manufactured at low cost.

The challenge stems in part from the fact that silicon spin qubits are made from single electrons and are extremely small.

"The wiring or 'interconnects' between multiple qubits is the biggest challenge towards a large scale quantum computer," said James Clarke, director of quantum hardware at Intel, whose team is building silicon qubits using using Intel's advanced manufacturing line, and who was not involved in the study. "Jason Petta's team has done great work toward proving that spin qubits can be coupled at long distances."

To accomplish this, the Princeton team connected the qubits via a "wire" that carries light in a manner analogous to the fiber optic wires that deliver internet signals to homes. In this case, however, the wire is actually a narrow cavity containing a single particle of light, or photon, that picks up the message from one qubit and transmits it to the next qubit.

The two qubits were located about half a centimeter, or about the length of a grain of rice, apart. To put that in perspective, if each qubit were the size of a house, the qubit would be able to send a message to another qubit located 750 miles away.

The key step forward was finding a way to get the qubits and the photon to speak the same language by tuning all three to vibrate at the same frequency. The team succeeded in tuning both qubits independently of each other while still coupling them to the photon. Previously the device's architecture permitted coupling of only one qubit to the photon at a time.

"You have to balance the qubit energies on both sides of the chip with the photon energy to make all three elements talk to each other," said Felix Borjans, a graduate student and first author on the study. "This was the really challenging part of the work."

Each qubit is composed of a single electron trapped in a tiny chamber called a double quantum dot. Electrons possess a property known as spin, which can point up or down in a manner analogous to a compass needle that points north or south. By zapping the electron with a microwave field, the researchers can flip the spin up or down to assign the qubit a quantum state of 1 or 0.

"This is the first demonstration of entangling electron spins in silicon separated by distances much larger than the devices housing those spins," said Thaddeus Ladd, senior scientist at HRL Laboratories and a collaborator on the project. "Not too long ago, there was doubt as to whether this was possible, due to the conflicting requirements of coupling spins to microwaves and avoiding the effects of noisy charges moving in silicon-based devices. This is an important proof-of-possibility for silicon qubits because it adds substantial flexibility in how to wire those qubits and how to lay them out geometrically in future silicon-based 'quantum microchips.'"

The communication between two distant silicon-based qubits devices builds on previous work by the Petta research team. In a 2010 paper in the journal Science, the team showed it is possible to trap single electrons in quantum wells. In the journal Nature in 2012, the team reported the transfer of quantum information from electron spins in nanowires to microwave-frequency photons, and in 2016 in Science they demonstrated the ability to transmit information from a silicon-based charge qubit to a photon. They demonstrated nearest-neighbor trading of information in qubits in 2017 in Science. And the team showed in 2018 in Nature that a silicon spin qubit could exchange information with a photon.

Jelena Vuckovic, professor of electrical engineering and the Jensen Huang Professor in Global Leadership at Stanford University, who was not involved in the study, commented: "Demonstration of long-range interactions between qubits is crucial for further development of quantum technologies such as modular quantum computers and quantum networks. This exciting result from Jason Petta's team is an important milestone towards this goal, as it demonstrates non-local interaction between two electron spins separated by more than 4 millimeters, mediated by a microwave photon. Moreover, to build this quantum circuit, the team employed silicon and germanium - materials heavily used in the semiconductor industry."

Researchers at LSTM have identified a completely new mechanism by which mosquitoes that carry malaria are becoming resistant to insecticide.

After studying both Anopheles gambiae and Anopheles coluzzii, two major malaria vectors in West Africa, they found that a particular family of binding proteins situated in the insect's legs were highly expressed in resistant populations.

First author on a paper published today in the journal Nature, Dr Victoria Ingham, explains: "We have found a completely new insecticide resistance mechanism that we think is contributing to the lower than expected efficacy of bed nets. The protein, which is based in the legs, comes into direct contact with the insecticide as the insect lands on the net, making it an excellent potential target for future additives to nets to overcome this potent resistance mechanism."

Examining the Anopheline mosquitoes, the team demonstrated that the binding protein, SAP2, was found elevated in resistant populations and further elevated following contact with pyrethroids, the insecticide class used on all bed nets. They found that when levels of this protein were reduced, by partial silencing of the gene, susceptibility to pyrethroids were restored; conversely when the protein was expressed at elevated levels, previously susceptible mosquitoes became resistant to pyrethroids.

The increase in insecticide resistance across mosquito populations has led to the introduction of new insecticide treated bed nets containing the synergist piperonyl butoxide (PBO) as well as pyrethroid insecticides. The synergist targets one of the most widespread and previously most potent resistance mechanisms caused by the cytochrome P450s. However, mosquitoes are continually evolving new resistance mechanisms and the discovery of this new resistance mechanism provides an excellent opportunity to identify additional synergists that could be used to restore susceptibility

Professor Hilary Ranson is senior author on the paper. She said: "Long-lasting insecticide treated bed nets remain one of the key interventions in malaria control. It is vital that we understand and mitigate for resistance within mosquito populations in order to ensure that the dramatic reductions in disease rates in previous decades are not reversed. This newly discovered resistance mechanism could provide us with an important target for both the monitoring of insecticide resistance and the development of novel compounds able to block pyrethroid resistance and prevent the spread of malaria."

Malaria parasites transform healthy red blood cells into rigid versions of themselves that clump together, hindering the transportation of oxygen. The infectious disease affects more than 200 million people across the world and causes nearly half a million deaths every year, according to the World Health Organization's 2018 report on malaria. Until now, however, researchers did not have a strong understanding of how the parasite so effectively infiltrated a system's red blood cells.

Now, researchers have detailed a comprehensive interaction network map of how malaria traffics between human host cells. They published their results on Sept. 27 in iScience, a Cell Press journal.

The researchers focused on Plasmodium falciparum, the parasite that causes the most severe form of malaria. This parasite infects a host red blood cell, triggering the production of several proteins into the host cell's cytoplasm--the bulk of the cell's mechanics and the liquid in which they're held, ultimately transforming the cell's physical form. Not only does this transformation make the cells stick in place, out of the body's immune response, it also helps the parasite travel to the surface of the cell and infect others. Together, the proteins work to proliferate the parasite, leading to the propagation of the malaria parasite.

"Our study sheds light on the highly complicated interplay between parasite and host proteins in the host cytoplasm," said Kentaro Kato, professor in the Laboratory of Sustainable Animal Environment in Tohoku University Graduate School of Agricultural Science and paper authors. "The work provides a reliable dataset of the interactions connecting dozens of proteins the parasite exports to continue infecting the host cells."

Previously, it was difficult to understand how the parasite works with the triggered proteins because the parasite was predicted to export about 400 proteins, yet another study found that proteins without the specific genetic sequence could also be exported to the cell's cytoplasm. In this study, the researchers opted to focus on one of these proteins without the parasitic mark--skeleton-binding protein 1 (SBP1), which is known to be highly important for malaria to propagate. By studying a protein known to be related to malaria virulence, but that isn't specifically triggered by the parasitic proteins, the researchers could narrow in on specific protein interactions to understand how the infection traffics within and beyond the host cells.

They used highly sensitive mass spectrometry to image the proteins interacting with SBP1 throughout the proliferation process, leading to the identification of several proteins specifically connected to transforming the host cell.

"In this study, we developed an alternative approach to identify exported proteins involved in the trafficking complex and in the parasite protein exports," Kato said. "The SBP1 interactions established in our study represent a powerful and invaluable platform to identify exported proteins related to severe malaria caused by Plasmodium falciparum."

The research provided a comprehensive map of SBP1 interactions which shed light on the complex relationships and interplay between host and parasite proteins. The findings also pave the way for further study and discussion on the molecular mechanism of the infections that affect human red blood cells. 

1. Preoperative levels of heart proteins may help predict death or cardiac complications in patients undergoing noncardiac surgery
Abstract: http://annals.org/aim/article/doi/10.7326/M19-2501
Editorial: http://annals.org/aim/article/doi/10.7326/M19-3718
URLs go live when the embargo lifts

Assessing preoperative levels of N-terminal pro-B-type natriuretic peptide (NT-proBNP), a biomarker of heart stress and structural changes, may improve risk prediction beyond the clinical risk score in patients having noncardiac surgery. Findings from a cohort study are published in Annals of Internal Medicine.

Globally, more than 200 million adults have major noncardiac surgery annually and more than 10 percent have major cardiac complications within the first 30 days, resulting in death, disability, prolonged hospitalization, or increased health care expenditure. Several guidelines recommend using the Revised Cardiac Risk Index (RCRI) to predict perioperative cardiac risk. Although the RCRI is easy to use, its accuracy in predicting major perioperative cardiovascular complications is limited. Preliminary evidence suggests that NT-proBNP measurement may improve perioperative cardiovascular risk prediction.

Researchers from McMaster University, Hamilton General Hospital planned a substudy of the VISION (Vascular Events in Noncardiac Surgery Patients Cohort Evaluation) study to determine whether preoperative NT-proBNP had additional predictive value beyond the RCRI for the composite of vascular death and myocardial injury within 30 days after noncardiac surgery. The substudy included 10,402 patents at 16 hospitals in 9 countries and all patients had NT-pro-BNP levels measured before surgery and troponin T levels measured daily for up to 3 days after surgery. The researchers found that preoperative NT-proBNP concentrations were independently associated with the occurrence of vascular death or myocardial injury at 30 days after surgery. Preoperative NT-proBNP thresholds in addition to the RCRI substantially improved discrimination of patients and perioperative risk stratification and also predicted the risk for secondary outcomes.

Media contacts: For embargoed PDFs please contact Lauren Evans at Laevans@acponline.org. To speak with the lead author, P.J. Devereaux, MD, PhD, please email PJ.Devereaux@phri.ca.

2. Majority of internal medicine residency program directors misinterpret ABIM leave policies
Misunderstandings about leave may lead to unnecessary extensions of resident training
Abstract: http://annals.org/aim/article/doi/10.7326/M19-2490
URLs go live when the embargo lifts

A recent nationwide survey of 279 internal medicine residency program directors showed that the vast majority did not correctly interpret the American Board of Internal Medicine (ABIM) leave policies. While 51 percent of those surveyed said they understood ABIM's Leave of Absence and Vacation policy, most could not answer specific questions about the rules. These misunderstandings could lead to unnecessary extensions in residents' training programs. Findings from a brief research study are published in Annals of Internal Medicine.

When managing parental leave, program directors must balance resident needs with adherence to ABIM policies (as they understand them), and must minimize extensions of training that are required when residents take more leave than is permitted. As such, the Association of Program Directors and the Internal Medicine (APDIM) Survey Committee of the ABIM collaborated in an effort to assess internal medicine program directors' understanding of ABIM leave policies and their application to common scenarios, including parental leave. The survey showed that about half of the program directors thought that they understood the policies, but their answers showed that they misinterpreted leave times as being shorter than they actually are. When presented with various scenarios for leave, the program directors rarely answered questions about them correctly. For example, when asked about a scenario where a resident asks for 8 weeks of maternity leave, only 6.5 percent of program directors correctly chose not to extend training; 82.7 percent said they would extend training to follow ABIM policy.

According to the authors, misunderstandings are of concern because many residents requesting leave worry about program extensions. Given the lack of clarity surrounding ABIM policies, the authors suggest that parental leave policies should be clarified.

Media contacts: For an embargoed PDF, please contact Lauren Evans at laevans@acponline.org.
To reach the lead author, Kathleen Finn, MD, M.Phil, please contact Michael Morrison at mdmorrison@partners.org.

Also new in this issue:

It's Time to Revise the Uniform Determination of Death Act
Ariane Lewis, MD; Richard J. Bonnie, LLB; and Thaddeus Pope, JD, PhD
Ideas & Opinions
Abstract: http://annals.org/aim/article/doi/10.7326/M19-2731