Tech

With the aging of the world's population, there is a growing interest in elucidating the factors that support wellbeing in old age. Longitudinal life course epidemiological research is required to provide a continuous view from birth to old age and clarify what factors in the early life stages (e.g., adolescence) enhance wellbeing in old age.

Dr. Syudo Yamasaki, Chief Researcher, Atsushi Nishida, Director of the Centre for Social Science and Medicine at Tokyo Metropolitan Institute of Medical Science and their colleagues have conducted joint research with the MRC Unit for Lifelong Health and Aging at University College London to analyze data from a large-scale cohort study that started immediately after World War II. It has continued for more than 60 years across the United Kingdom in order to answer the question of what factors in adolescence contribute to wellbeing in older age.

We found that adolescent values of prioritizing their interests and curiosity predicted higher wellbeing in old age. Dr. Yamasaki said, "This result suggests that it is important to create an environment that fosters intrinsic motivations of adolescents and young adults to promote wellbeing in old age."

In jargon, they are called "bad metals", but they are not really so bad. As a matter of fact, they are the best superconductors because they are able to conduct current with the highest efficiency and without resistance up to high temperatures. This has been seen experimentally. Yet their behaviour remains a mystery. The repulsive forces between the electrons in these materials are much stronger than in low-temperature superconductors: so how do particles with the same charge overcome these forces and manage to pair-up and to transport current as it happens in "traditional" superconductors? A team of researchers of SISSA in Trieste in collaboration with the Vienna University of Technology have found a possible, surprising answer. According to the study published in Physical Review Letters, in these materials the electrons would transform into new "objects", with an unprecedented character that would allow them to pair up and thereby superconduct the current. In their research, the researchers also demonstrated the peculiarity of a new type of "Bad metals", called "Hund's metals", important for a class of iron-based materials. Scientists believe that these materials are particularly interesting because they are superconductive and rather malleable, which makes them highly suited to technological applications.

Low-temperature superconductors

"Superconductors are interesting materials because they hide many mysteries that remain unsolved and, at the same time, they offer an incredible application potential," explain Laura Fanfarillo, Angelo Valli and Massimo Capone, authors of the research. They are chemical compounds which, below a critical temperature, conduct electricity without any resistance, so without heat dissipation. It is easy to imagine their potential in the technological field. Were it not that for many of them, so-called "low-temperature superconductors", superconductivity appears at temperatures very close to the absolute zero, making their use complicated and very costly. However, there are also high-temperature superconductors, such as bad metals, whose critical temperature, although well below zero, require a much less complicated and expensive cooling. For this reason, these materials are considered to be the most interesting superconductors to explore in order to shed light on the physical characteristics that make them so special.

"And yet they move (together)"

The researchers explain "In low-temperature superconductors we know that superconductivity is the result of the pairing of electrons that overcome the repulsion due to their negative charge thanks to a "mediator". Once organised into pairs the electrons begin to move coherently and transport electric current without encountering any resistance. In bad metals, the Coulomb repulsion, which the electrons are subject to, is much stronger than in traditional metals. This repulsion, in theory, should prevent even more decisively the formation of these pairs and the transport of the supercurrent." This is where the question arises: "Since we know that the pairing between electrons is the mechanism at the base of superconduction and that, at least in this case, there is a mediator, it remains to be understood how bad metals are such good superconductors. With our calculations, we have tried to shed light on this intriguing mystery".

Quasiparticles to conduct electricity

What the scientists discovered is that it is precisely the characteristics that, at a superficial glance, would make them the worst possible candidates, that turn these materials into such powerful superconductors. In these materials, the electrons transform into peculiar "quasiparticles" whose characteristics are actually much more compatible with pairing, thereby justifying their experimental behaviour. However, it does not end here: "In this work we also demonstrated that a new type of bad metal characterised by a peculiar type of repulsion, called "Hund's metal", opens up interesting prospects in the field of superconductivity". "Our results" conclude the scientists "accurately and elegantly explain a quantity of experimental evidence in the class of ferrous superconductors, a relatively new type of material discovered in 2008, but whose unprecedented properties are still a field of investigation full of questions for scientists".

Oxygen evolution reaction (OER) is a key process for many energy devices such as electrolyzers and rechargeable metal-air batteries. Tremendous studies have been devoted to obtaining cost-effective, efficient and durable OER catalysts. Among them, nickel-based materials are considered to be promising candidates for OER in alkaline media. However, their performances are still below the expectation and the active sites are often controversial.

Recently, Associate Professor Yuqin Zou from Hunan University and Professor Xia Lu from Sun Yat-sen University proposed an interlayer ligand engineering strategy on β-Ni(OH)2 for OER.

The alkoxyl substituted β-Ni(OH)2 are facilely prepared by an one-step solvothermal reaction. Assisted by subsequent powder X-ray diffraction (PXRD) and crystalline structure computational simulation, the corresponding chemical formula can be described as Ni[(OH)1-y(L)y]2 (0?y?1), in which L represents alkoxyl ligands. The selected alkoxyl could be methoxyl, ethoxyl, propoxyl and isopropoxyl, or even the combination of methoxyl and ethoxyl. Owing to the chain length, electronegativity and hydrophilicity differences of these alkoxyl, the alteration of electron configuration and three-phase interfaces of Ni[(OH)1-y(L)y]2 are achieved, and the ethoxyl substituted one (NiEt) shows great potential to be efficient OER catalysts (Figure 1).

Combining with X-ray absorption spectroscopy (XAS) and other ex situ physical analysis, the critical active species of NiEt is formed via hydroxylation and subsequent de-protonation, existing as high valent Niδ+ (3

The Japanese research team elucidated the microscopic mechanism in which amorphous silica(1) becomes negatively charged as a vibrational energy harvester(2), which is anticipated to achieve self-power generation without charging, as it is needed for IoT that is garnering attention in recent years with its "trillion sensors" that create a large-scale network of sensors. Unlike wind power and solar power generation, vibrational power generation, which utilizes natural vibration for power generation, is not affected by weather.

Vibrational energy harvester that uses potassium ion electret, which the research group had previously developed, is of interest since it can operate semi-permanently. The potassium ion electret(3) is a vibrational energy harvester that uses introduction of potassium atoms in amorphous silica to create a negative charge on the amorphous silica. However, its microscopic mechanism was unknown, making it difficult to improve its performance.

Through quantum mechanics calculations, the research group discovered that when potassium atoms are inserted in amorphous silica, electrons are provided from the potassium atom to the silicon atom. This causes the silicon atom to behave like a phosphorus atom. Silicon atoms form 5 covalent bonds with oxygen atoms instead of the usual 4, creating a SiO5 structure. We discovered that this structure is what accumulates negative charge.

This result provides a design guidance toward improving reliability and longevity of vibrational energy harvesters. This would allow sensors that do not require charging, to become widely available, and contribute toward actualization of the internet of things (IoT)(4).

This study was jointly conducted by the research groups of professor Gen Hashiguchi of Faculty of Engineering, Shizuoka University and professor Hiroshi Toshiyoshi of Institute of Industrial Science, The University of Tokyo, along with professor Kenji Shiraishi, graduate student Toru Nakanishi, researcher Kenta Chokawa, and assistant professor Masaaki Araidai of Institute of Materials and Systems for Sustainability, Nagoya University, as part of JST Strategic Basic Research Programs. JST aims to create innovative basic technologies that convert unused microscopic energy in the environment into electric energy (energy harvesting). This result will be presented at the 37th Sensor Symposium "On Sensors, Micromachines and Applied Systems" (held online), titled "Investigation of negative charge storage mechanism in the potassium ion electret by first-principle calculation."

The water electrolysis is an electrochemical way for production of hydrogen, which is considered as one of the future energy carrier molecules. Therefore, looking at numerous advantages of proton exchange membrane electrolysis compared to the classical alkaline variant, it's efficiency and applicability on the large scale is of huge importance nowadays. However, the slow kinetics of the anode oxygen evolution reaction (OER) limits the overall electrolysis process and requires an active and stable electrocatalyst. Such need inspired the scientists of Chemical Metal Science and Physics of Correlated Matter departments at MPI CPfS together with the Fritz-Haber-Institut in Berlin to employ their longstanding expertise in chemistry of intermetallic compounds, electronic features of solid matter and electrocatalysis to make a step forward in this challenging direction. As a result of fruitful teamwork, the concept of cooperative phases with different stabilities under OER conditions was successfully demonstrated with the intermetallic compound Hf2B2Ir5 as a self-optimizing electrocatalyst for OER.

Based on chemical bonding analysis, the intermetallic compound Hf2B2Ir5 has a cage-like type of the crystal structure: the two-dimensional layers of B2Ir8 units are interconnected by two- and three-center Ir-Ir interactions to polyanionic framework and hafnium atoms are guesting in such anionic cages. The atomic interactions features are reflected in the electronic structure of Hf2B2Ir5 and its chemical behaviour under OER conditions. The initial electrochemical OER activity of Hf2B2Ir5 sustains during the continuous operation at elaborated current densities of 100 mA cm-2 for at least 240 h (Figure 1) and positions this material among Ir-based state-of-the-art electrocatalysts. The harsh oxidative conditions of OER activate the surface-limited changes of the pristine material and as a result the electrochemical performance is related to the cooperative work of Ir-terminated surface of the ternary compound itself and agglomerates of IrOx(OH)y(SO4)z particles (inset of Figure 1). The latter are formed mainly due to the oxidation of HfB4Ir3 secondary phase and near-surface oxidation of the investigated compound. The presence of at least two OER-active states of Ir, originated from the Hf2B2Ir5 under OER conditions, was confirmed by the XPS analysis (Figure 2). The experimental data (electrochemical results, material characterization using bulk-and surface-sensitive methods, elemental analysis of the used electrolyte) are consistent with the chemical bonding analysis. The illustrated concept of cooperative phases with different chemical stabilities under OER conditions can be explored to other systems and offers a perspective knowledge-based way for discovery of new effective OER-electrocatalysts.

Nanographene is a material that is anticipated to radically improve solar cells, fuel cells, LEDs and more. Typically the synthesis of this material has been imprecise and difficult to control. For the first time, researchers have discovered a simple way to gain precise control over the fabrication of nanographene. In doing so, they have shed light on the previously unclear chemical processes involved in nanographene production.

You have probably heard of graphene, one-atom-thick sheets of carbon molecules, that are supposed to revolutionize technology. Units of graphene are known as nanographene; these are tailored to specific functions and as such their fabrication process is more complicated than that of generic graphene. Nanographene is made by selectively removing hydrogen atoms from organic molecules of carbon and hydrogen, a process called dehydrogenation.

"Dehydrogenation takes place on a metal surface such as that of silver, gold or copper, which acts as a catalyst, a material that enables or speeds up a reaction," said Assistant Professor Akitoshi Shiotari from the Department of Advanced Materials Science. "However, this surface is large relative to the target organic molecules. This contributes to the difficulty in crafting specific nanographene formations. We needed a better understanding of the catalytic process and a more precise way to control it."

Shiotari and his team, through exploring various ways to perform nanographene synthesis, came up with a method that offers the precise control necessary and is also very efficient. They used a specialized kind of microscope called an atomic force microscope (AFM), which measures details of molecules with a nanoscopic needlelike probe. This probe can be used not only to detect certain characteristics of individual atoms, but also to manipulate them.

"We discovered that the metal probe of the AFM could break carbon-hydrogen bonds in organic molecules," said Shiotari. "It could do so very precisely given its tip is so minute, and it could break bonds without the need for thermal energy. This means we can now fabricate nanographene components in a more controlled way than ever before."

To verify what they were seeing, the team repeated the process with a variety of organic compounds, in particular two molecules with very different structures called benzonoids and nonbenzonoids. This demonstrates the AFM probe in question is able to pull hydrogen atoms from different kinds of materials. Such a detail is important if this method is to be scaled up into a commercial means of production.

"I envisage this technique could be the ultimate way to create functional nanomolecules from the bottom up," said Shiotari. "We can use an AFM to apply other stimuli to target molecules, such as injecting electrons, electronic fields or repulsive forces. It is thrilling to be able to see, control and manipulate structures on such an incredibly miniscule scale."

Electron microscopes provide deep insight into the smallest details of matter and can reveal, for example, the atomic configuration of materials, the structure of proteins or the shape of virus particles. However, most materials in nature are not static and rather interact, move and reshape all the time. One of the most common phenomena is the interaction between light and matter, which is ubiquitous in plants as well as in optical components, solar cells, displays or lasers. These interactions - which are defined by electrons being moved around by the field cycles of a light wave - happen at ultrafast time scales of femtoseconds (10-15 seconds) or even attoseconds (10-18 seconds, a billionth of a billionth of a second). While ultrafast electron microscopy can provide some insight into femtosecond processes, it has not been possible, until now, to visualize the reaction dynamics of light and matter occurring at attosecond speeds.

Now, a team of physicists from the University of Konstanz and Ludwig-Maximilians-Universität München have succeeded in combining a transmission electron microscope with a continuous-wave laser to create a prototypical attosecond electron microscope (A-TEM). The results are reported in the latest issue of Science Advances.

Modulating the electron beam

"Basic phenomena in optics, nanophotonics or metamaterials happen at attosecond times, shorter than a cycle of light", explains Professor Peter Baum, lead author on the study and head of the Light and Matter research group at University of Konstanz's Department of Physics. "To be able to visualize ultrafast interactions between light and matter requires a time resolution below the oscillation period of light". Conventional transmission electron microscopes use a continuous electron beam to illuminate a specimen and create an image. To achieve attosecond time resolution, the team led by Baum uses the rapid oscillations of a continuous-wave laser to modulate the electron beam inside the microscope in time.

Ultra-short electron pulses

Key to their experimental approach is a thin membrane which the researchers use to break the symmetry of the optical cycles of the laser wave. This causes the electrons to accelerate and decelerate in rapid succession. "As a result, the electron beam inside the electron microscope is transformed into a series of ultrashort electron pulses, shorter than half an optical cycle of the laser light", says first author Andrey Ryabov, a postdoctoral researcher on the study. Another laser wave, which is split from the first one, is used to excite an optical phenomenon in a specimen of interest. The ultrashort electron pulses then probe the sample and its reaction to the laser light. By scanning the optical delay between the two laser waves, the researchers are then able to obtain attosecond resolution footage of the electromagnetic dynamics inside the specimen.

Simple modifications, large impact

"The main advantage of our method is that we are able to use the available continuous electron beam inside the electron microscope rather than having to modify the electron source. This means that we have a million times more electrons per second, basically the full brightness of the source, which is key to any practical applications", continues Ryabov. Another advantage is that the necessary technical modifications are rather simple and do not require electron gun modifications.

As a result, it is now possible to achieve attosecond resolution in a whole range of space-time imaging techniques such as time-resolved holography, waveform electron microscopy or laser-assisted electron spectroscopy, amongst others. In the long term, attosecond electron microscopy may help to uncover the atomistic origins of light-matter interactions in complex materials and biological substances.

Human brain can process a massive number of light/spectral signals at high speed, partly because it perceives lights as a combination of colors and intensities. However, the existing photodetectors can only indicate light intensities. It was recently reported that integrating dozens of photodetectors with semiconductors presenting different bandgaps can reconstruct spectral curves of incident lights. Nevertheless, such approach requires chip-level device assembly and signal-processing system, and can generate redundant signals for applications that do not need detailed spectral information.

In a new paper published in Light Science & Application, a team of scientists, led by Professor Shi-Jin Ding from State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, China, have developed a low cost, flexible optoelectronic cell that can detect light intensity and perceive colour, inspired by human visual and psychological light perceptions (Figure 1). Bandgap-gradient perovskites, prepared by a halide-exchanging method via dipping in a solution, are developed as the photoactive layer of the cell. Since photon absorption can only occur at energies above the bandgap of semiconductors, the devices can sense the spectral content of light signals with high resolution. The fabricated device produces two output signals: one shows linear responses to both photon energy and flux, while the other depends on only photon flux. Thus, by combining the two signals, the single device can project the monochromatic and broadband spectra into the total photon fluxes and average photon energies (i.e., intensities and hues). which are in good agreement with those obtained from a commercial photodetector and spectrometer (Figure 2). Under changing illumination in real time, the prepared device can instantaneously provide intensity and hue results.

Chemical/bio-sensing by applying the colour-perception device is demonstrated. The colorimetric chemical/bio-assay setup is shown in Figure 3: chemical/bio-analytes will modify the colour of the sensing material, and the bandgap-gradient device will convert the colour change to an electrical signal. For this simple proof of concept, a pH testing paper that turns from red to green for pH values from 1 to 9, is used. When using a single silicon photodiode output current, such colour differences are not detectable. Spectral curves of the pH testing papers under the same illumination measured by a spectrometer can distinguish the different colours by presenting different peak positions. However, this method not only requires bulky equipment but also generates spectral information that is redundant for sensing applications. The response of the bandgap-gradient device can clearly distinguish between the various pH values. Therefore, the colour-perception device effectively achieves colorimetric chemical/bio-sensing with only a single device and by generating only one or two current signals.

"We think that bandgap-gradient structures with high degrees of control can be achieved by other fabrication technologies with processing parameters that can produce a gradient. Colour-perception devices with excellent performance, small size and integratable structure would be achieved by further optimizing the selection of the optoelectronic material and the design of the bandgap-gradient structure. This device can be used in colour-sensing pixels, which may be more simplified than existing devices containing several photodetectors and optical filters. Multifunctional sensors can be produced by combining devices with stimuli-responsive materials to detect physical/chemical/bio-stimuli through a comparison of colours/spectra. Therefore, this work provides a new category of optoelectronic devices that are capable of spectrum projection and hue perception, thereby opening up a range of colourful applications." the scientists forecast.

The understanding of unconventional superconductivity is one of the most challenging and fascinating tasks of solid-state physics. Different classes of unconventional superconductors share that superconductivity emerges near a magnetic phase despite the underlying physics is different. Two of these unconventional materials are the heavy-fermion and the iron-based superconductors.

Researcher from the Max Planck Institute for Chemical Physics of Solids applied large hydrostatic pressures to tiny single crystals of CeFeAsO, a non-superconducting parent compound to iron-based superconductors, using diamond anvil pressure cells. By electrical, magnetic and structural measurements they showed that upon increasing the applied pressure, the material characteristics change from that of an iron-pnictide material to that of a heavy-fermion metal. Surprisingly, a narrow superconducting phase emerges in the boundary region between the typical iron-pnictide spin-density-wave magnetism and a Ce-based Kondo-regime. This suggests that the two major phenomena characterizing iron-pnictides and heavy-fermions, spin-density-wave magnetism and the Kondo-effect, work together to produce superconductivity in CeFeAsO.

Cataclysmic astrophysical events such as black hole mergers could release energy in unexpected forms. Exotic low-mass fields (ELFs), for example, could propagate through space and cause feeble signals detectable with quantum sensor networks such as the atomic clocks of the GPS network or the magnetometers of the GNOME network. These are the results of theoretical calculations undertaken by a research group including Dr. Arne Wickenbrock of the PRISMA+ Cluster of Excellence at Johannes Gutenberg University Mainz (JGU) and the Helmholtz Institute Mainz (HIM). They are particularly interesting in the context of the search for dark matter, as low-mass fields are regarded as promising candidates for this exotic form of matter.

From multi-messenger astronomy to the search for dark matter

Multi-messenger astronomy involves the coordinated observation of disparate signals that stem from the same astrophysical event. Since the first detection of gravitational waves with the LIGO interferometer several years ago, the interest in this field has expanded enormously and it has yielded a tremendous amount of new information originating from the depths of the universe. "When gravitational waves are generated somewhere in space and detected on Earth, numerous telescopes now focus on the event to record various signals, such as those in the form of electromagnetic radiation, for instance," explains Arne Wickenbrock. "We asked ourselves what would happen if part of the observed energy released by such events was also radiated in the form of exotic low-mass fields or ELFs. Would we be able to detect them with our existing networks of quantum sensors?"

The scientists' calculations have confirmed that this could be the case for certain parameters. "We also reasoned that such fields, when radiated, would cause a characteristic frequency signature in the networks," adds Arne Wickenbrock. "The signal would be similar to the sound of a passing siren, sweeping from high to low frequencies." The researchers have two particular networks in mind: the worldwide GPS network of atomic clocks and the GNOME network, which is comprised of a multitude of magnetometers distributed around the globe. On the basis of the expected strength of the signal, the GPS system should currently be sensitive enough to detect ELFs. The work group of JGU Professor Dmitry Budker at HIM, together with other teams, is currently upgrading the GNOME network, and on completion this should also be sensitive enough to observe such events.

Potential ELFs are of particular significance in the search for dark matter. Although we know this strange form of matter must exist, nobody yet knows what it is made of. Specialists are considering and researching a whole range of possible particles that might theoretically qualify as candidates. Among the most promising current candidates are extremely light bosonic particles, which can also be seen in terms of a classic field oscillating at a particular frequency. "Thus, in the depths of the universe, dark matter in the form of ELFs may be created during the merger of two black holes," concludes Arne Wickenbrock. "Precision quantum sensor networks, in turn, could function as ELF telescopes, adding another important element to the toolbox of multi-messenger astronomy."

Announcing a new article publication for BIO Integration journal. In this review article the authors Yun Chen, Gongfa Jiang, Yue Li, Yutao Tang, Yanfang Xu, Siqi Ding, Yanqi Xin and Yao Lu from Xiangtan University, Xiangtan, China and Sun Yat-sen University, Guangzhou, China consider the application of artificial intelligence imaging analysis methods for COVID-19 clinical diagnosis.

The world is facing a key health threat because of the outbreak of COVID-19. Intelligent medical imaging analysis is urgently needed to make full use of chest images in COVID- 19 diagnosis and its management due to the important role of typical imaging findings in this disease. The authors review artificial intelligence (AI) assisted chest imaging analysis methods for COVID-19 which provide accurate, fast, and safe imaging solutions.

In particular, medical images from X-ray and CT scans are used to demonstrate that AI techniques based on deep learning can be applied to COVID-19 diagnosis. In order to improve the performance of AI techniques, it is important to establish a database for public researches and to find a way to extract lesions accurately. Moreover, efficient deep learning models should be explored for COVID-19 applications.

It is important that multisource data can be applied to the diagnosis, monitoring, and prediction of COVID-19 as images from different imaging modalities can only show anatomical or functional information of patients with this disease. For such cases, the multisource data should include imaging findings, clinical symptoms, pathological features, blood tests, etc. In order to build analysis models purposefully and improve them, researchers can study the correlation among these datasets from different sources. This may help to maximize the value of AI in COVID-19 clinical diagnosis.

Thermoelectric materials can turn a temperature difference into electricity. Organic thermoelectric materials could be used to power wearable electronics or sensors; however, the power output is still very low. An international team led by Jan Anton Koster, Professor of Semiconductor Physics at the University of Groningen, has now produced an n-type organic semiconductor with superior properties that brings these applications a big step closer. Their results were published in the journal Nature Communications on 10 November.

The thermoelectric generator is the only human-made power source outside our solar system: both Voyager space probes, which were launched in 1977 and are now in interstellar space, are powered by generators that convert heat (in this case, provided by a radioactive source) into an electric current. 'The great thing about such generators is that they are solid-state devices, without any moving parts,' explains Koster.

Conductivity

However, the inorganic thermoelectric material used in the Voyager's generators is not suitable for more mundane applications. These inorganic materials contain toxic or very rare elements. Furthermore, they are usually rigid and brittle. 'That is why interest in organic thermoelectric materials is increasing,' says Koster. Yet, these materials have their own problems. The optimal thermoelectric material is a phonon glass, which has a very low thermal conductivity (so that it can maintain a temperature difference) and also an electron crystal with high electrical conductivity (to transport the generated current). Koster: 'The problem with organic semiconductors is that they usually have a low electrical conductivity.'

Nevertheless, over a decade of experience in developing organic photovoltaic materials at the University of Groningen has led the team on a path to a better organic thermoelectric material. They focused their attention on an n-type semiconductor, which carries a negative charge. For a thermoelectric generator, both n-type and p-type (carrying positive charge) semiconductors are needed, although the efficiency of organic p-type semiconductors is already quite good.

Buckyballs

The team used fullerenes (buckyballs, made up of sixty carbon atoms) with a double-triethylene glycol-type side-chain added to them. To increase the electrical conductivity, an n-dopant was added. 'The fullerenes already have a low thermal conductivity, but adding the side chains makes it even lower, so the material is a very good phonon glass,' says Koster. 'Furthermore, these chains also incorporate the dopant and create a very ordered structure during annealing.' The latter makes the material an electric crystal, with an electrical conductivity similar to that of pure fullerenes.

'We have now made the first organic phonon glass electric crystal,' Koster says. 'But the most exciting part for me is its thermoelectric properties.' These are expressed by the ZT value. The T refers to the temperature at which the material operates, while Z incorporates the other material properties. The new material increases the highest ZT value in its class from 0.2 to over 0.3, a sizeable improvement.

Sensors

'A ZT value of 1 is considered a commercially viable efficiency, but we believe that our material could already be used in applications that require a low output,' says Koster. To power sensors, for example, a few microwatts of power are required and these could be produced by a couple of square centimetres of the new material. 'Our collaborators in Milan are already creating thermoelectric generators using fullerenes with a single side chain, which have a lower ZT value than we now have.'

The fullerenes, side chain and dopant are all readily available and the production of the new material can likely be scaled up without too many problems, according to Koster. He is extremely happy with the results of this study. 'The paper has twenty authors from nine different research groups. We used our combined knowledge of synthetic organic chemistry, organic semiconductors, molecular dynamics, thermal conductivity and X-ray structural studies to get this result. And we already have some ideas on how to further increase the efficiency.'

Solar power is an eco-friendly alternative to conventional, non-renewable sources of energy. However, current solar panels require the use of toxic materials as buffers, which is not sustainable. To this end, a team of scientists in Korea developed a new eco-friendly alternative, called the ZTO buffer, which can overcome this limitation. This new development to make solar panels even more sustainable is indeed a cherry on top.

The imminent threat of the climate change crisis is unequivocal, and given the urgency, there is a need to accelerate the renewable energy transition. In recent years, solar power has emerged as one of the most promising candidates for this task. Now, scientists from Incheon National University, Korea, explain their latest contribution to this field. Their findings were published in a new study in Nano Energy and made available online on August 10, 2020 (ahead of the final publication of the issue in December 2020).

Solar panels are composed of photovoltaic cells, whereby materials exposed to light generate excited electrons, in other words: an electric current. Modern thin-film solar cells are made up of micrometer- or submicrometer-thick layers of a photovoltaic material, allowing them to be integrated into flexible, lightweight panels for use in a variety of substrates. However, this process has some limitations. Prof JunHo Kim, who led the study, explains, "Most thin-film solar cells include toxic and expensive elements, which may hinder the expansion of solar cell applications." Prof Kim and his team are working on the production of a solar cell using naturally abundant, eco-friendly materials, which are easy to extract and inexpensive to manufacture.

The scientists looked at eco-friendly cells made up of kesterite, a natural mineral that acts as a photon absorber. Most kesterite cells use a buffer layer made of cadmium sulfide (CdS) to optimize their performance. Despite their efficiency, the pollution associated with making these buffers and the toxicity of cadmium are not desirable traits in an eco-friendly solar cell. To deal with this issue, the researchers examined a promising alternative, called the "ZTO buffer." To further improve the efficiency of the solar cell, the team aligned the energy levels of the electrons between the absorber layer (kesterite) and the buffer layer (ZTO). This allowed for a better circulation of electrons between the two layers, increasing the cell's voltage and overall performance, with a power conversion efficiency of 11.22%. To put things into perspective, current kesterite cells using CdS buffers have a maximum efficiency of 12.6%, meaning that the proposed cell showed high efficiency. This technique is the first to yield such a high performance using solely eco-friendly, abundant, and inexpensive materials.

The importance of this research will only grow with the expected increase in the share of renewable energy in the next few decades. As the demand for solar panels grows, it is especially important to source its components in the most environmentally friendly and cheapest way possible. The technology described by Dr Kim and his team brings us a step closer to this goal. The research team's vision for their invention is that of a renewable future. Prof Kim concludes by talking about the potential applications of their findings, "Eco-friendly thin-film solar cells could be installed on the roofs and walls of buildings and houses to produce electricity near us. They could also be employed in ground vehicles (cars, buses, and trucks) and marine transportations (boats and long-range ships) to partially support electric power."

A new study from researchers in the Perelman School of Medicine at the University of Pennsylvania and Independence Blue Cross shows that when patients' primary care doctors were able to photograph areas of concern and share them with dermatologists, the response time for a consultation dropped from almost 84 days to under five hours. In addition, the study did not show any undue increases in utilization or cost that might be prohibitive to making the practice widespread. The findings were published today in Telemedicine and e-Health.

"Telemedicine offers the opportunity to accelerate health care access by getting around infrastructure barriers: namely, heavily booked dermatology practices," said the study's senior author, Jules Lipoff, MD, an assistant professor of Clinical Dermatology. "Our study provides evidence that more patients can be cared for with the same amount of resources we're using now."

Although this study's data comes from before the emergence of COVID-19, telemedicine measures like these have taken on a particular importance since the outbreak because of its ability to accommodate social distancing.

"The COVID-19 pandemic has illustrated just how important it is to ensure patients have the ability to access the care, education and support they need virtually," said co-author Aaron Smith-McLallen, director of Health Informatics and Advanced Analytics at Independence Blue Cross. "We see a future where more and more of our members will be using digital tools to complement in-person care, and we are working with our provider partners to make that a reality."

Lipoff, Smith-McLallen, and their fellow researchers, including lead author Neha Jariwala, MD, a resident in Dermatology, designed the study to implement a shared digital photography service (also known as "Store-and-Forward") between providers. Previously, similar models had been tested in smaller patient groups - including in the inpatient setting as part of the Penn Medicine Center for Health Care Innovation's accelerator program in 2013. In this larger study, five primary care practices trained their clinicians to take the photos received over a secure application to a rotation of eight dermatologists for consults. This workflow was used instead of the usual process of referring patients to the next available in-person dermatology appointment.

In the study's process, once the dermatologists reviewed the pictures of the concerning areas, they then responded to the primary care physician with clinical recommendations, which included a triage determination of whether an in-person visit with a dermatologist was needed. The study's dermatologists also did these consultations within the course of their regular clinical duties without needing additional dedicated time to the effort.

Overall, 167 patients took part in the study, with a retrospective control group of 1,962 patients for comparison who had followed the traditional consultation system of seeing their primary care doctor, receiving a referral, and then scheduling an in-person appointment with a dermatologist.

In addition to the dramatic reduction in time to consultation, the study also suggested that the difference in total medical costs did not significantly differ between the telemedicine patients and those in the non-telemedicine arm of the study. Moreover, there was not a significant increase in consults when telemedicine was used compared to the previous process.

The study was conducted from June 2016 until May 2017, well before the COVID-19-related expansion of telemedicine, which was due, in large part, to the relaxation of rules for care reimbursement, traditionally the highest barrier for widespread telemedicine use. However, those changes have been mostly related to video calls with health care providers.

"Video-based telemedicine has been extremely helpful amid the social distancing precautions brought about by the COVID-19 outbreak," Lipoff explained. "But we also need to look toward how we can expand other forms that may be more efficient in delivering care, such as 'Store-and-Forward' and hybrid models, since we've shown how effective they can be."

It is unclear whether many of the changes in telemedicine brought about from the COVID-19 expansion will become permanent. But the researchers hope their study can serve as proof of the viability of photo-based telemedicine for dermatology ¬- and other specialties, too.

WILMINGTON, Del. (November 11, 2020) - Interventional radiologists with Nemours Children's Health System have identified a new source of abnormal lymphatic flow between the liver and the lungs that may be responsible for some cases of plastic bronchitis. Plastic bronchitis is a rare but serious late complication in patients with congenital heart disease who had Fontan surgery. A report detailing the discovery of this fluid leak, and successful treatment of two cases was published in European Heart Journal.

In plastic bronchitis, lymph fluid drains into the lungs, blocking patients' airways and causing difficulty breathing. Recent advances in the use of dynamic contrast-enhanced magnetic resonance lymphangiogram have identified that in 94% of patients, the cause is identified as lymph fluid draining from the thoracic duct that can be successfully treated by blocking or embolizing this duct. However, in a subset of patients, the leak cannot be identified and treated.

"Through sophisticated lymphatic imaging techniques, we have identified a new source of lymph fluid leak from the liver to the chest in patients with plastic bronchitis, opening up treatment options where there previously were none," said Deborah A. Rabinowitz, MD, an interventional radiologist with Nemours Children's Health System in Wilmington, Del. "This discovery signals a connection between the liver's lymph system and chest structures that could explain pulmonary symptoms in patients with other conditions, such as congestive heart failure and liver cirrhosis."

The case report details the care of two teen boys who had previously undergone Fontan surgery, an open heart surgery which directs blood flow to the lungs. The first patient was transferred to Nemours/Alfred I. duPont Hospital for Children after unsuccessful identification of lymph fluid leak. Further lymphatic imaging identified the leaking duct from the liver. Despite the complexity of the liver's lymphatic anatomy, the abnormal pathway was identified and embolized to treat this patient's condition.

The second patient was transferred to Nemours for emergent care for a persistent cough and fatigue. Once diagnosed with plastic bronchitis, the team did not identify the more common leaks in the thoracic ducts. But based on the experience with the first patient, the second patient underwent liver lymphangiogram, which identified a similar leak from the liver to the airway. This discovery enabled the team to embolize the leaking duct with immediate relief of his symptoms.

This discovery improves our understanding of the role of the liver as a source of plastic bronchitis in select patients, and advances an innovative and effective treatment approach.