Infrared-reflective ultrathin-metal-film-based transparent electrode with ultralow optical loss for high efficiency in solar cells

Advanced Materials

High‐performance perovskite solar cells (PSCs) typically require interfacial passivation, yet this is challenging for the buried interface, owing to the dissolution of passivation agents during the deposition of perovskites. Here, this limitation is overcome with in situ buried‐interface passivation—achieved via directly adding a cyanoacrylic‐acid‐based molecular additive, namely BT‐T, into the perovskite precursor solution. Classical and ab initio molecular dynamics simulations reveal that BT‐T spontaneously may self‐assemble at the buried interface during the formation of the perovskite layer on a nickel oxide hole‐transporting layer. The preferential buried‐interface passivation results in facilitated hole transfer and suppressed charge recombination. In addition, residual BT‐T molecules in the perovskite layer enhance its stability and homogeneity. A power‐conversion efficiency (PCE) of 23.48% for 1.0 cm2 inverted …

Nature

Solar fuels offer a promising approach to provide sustainable fuels by harnessing sunlight,. Following a decade of advancement, Cu2O photocathodes are capable of delivering a performance comparable to that of photoelectrodes with established photovoltaic materials, –. However, considerable bulk charge carrier recombination that is poorly understood still limits further advances in performance. Here we demonstrate performance of Cu2O photocathodes beyond the state-of-the-art by exploiting a new conceptual understanding of carrier recombination and transport in single-crystal Cu2O thin films. Using ambient liquid-phase epitaxy, we present a new method to grow single-crystal Cu2O samples with three crystal orientations. Broadband femtosecond transient reflection spectroscopy measurements were used to quantify anisotropic optoelectronic properties, through which the carrier mobility along the [111 …

arXiv preprint arXiv:2404.15763

We demonstrate a simple, low-cost and ultracompact chiral resonant metasurface design, which, by strong local coupling to a quantum gain medium (quantum emitters), allows to implement an ultra-thin metasurface laser, capable of generating tunable circularly polarized coherent lasing output. According to our detailed numerical investigations the lasing emission can be transformed from linear to circular and switch from right- to left-handed circularly polarized (CP) not only by changing the metasurface chiral response but also by changing the polarization of a linearly polarized pump wave, providing thus dynamic lasing-polarization control. Given the increasing interest for CP laser emission, our chiral metasurface laser design proves to be a versatile yet straightforward strategy to generate strong and tailored CP emission laser, promising great potential for future applications in both photonics and materials science.

Advanced Functional Materials

Perovskite solar cells have led the new surge of solar energy research. However, their instability is a pressing issue mostly attributed to the perovskite interface with charge‐selective transport layers. In this work, diethylammonium iodide (DEAI) surface treatment is used to mitigate interfacial non‐radiative recombination losses by forming a mixed phase of layered perovskite on the surface. This results in enhanced device performance with the power conversion efficiency of 23.3% and improved operational stability under thermal stress. Moreover, the DEAI treatment facilitates interfacial hole transfer, enabling a carbon‐based hole transport layer‐free perovskite solar cell with a power conversion efficiency of 15.6%.

Advanced Materials

Efficient and robust n‐i‐p perovskite solar cells necessitate superior organic hole‐transport materials with both mechanical and electronic prowess. Deciphering the structure−property relationship of these materials is crucial for practical perovskite solar cell applications. Through direct arylation, we synthesized two high glass transition temperature molecular semiconductors, DBC‐ETPA (202 °C) and TPE‐ETPA (180 °C), using dibenzo[g,p]chrysene (DBC) and 1,1,2,2‐tetraphenylethene (TPE) tetrabromides with triphenylene–ethylenedioxythiophene‐dimethoxytriphenylamine (ETPA). In comparison to spiro‐OMeTAD, both semiconductors exhibit shallower HOMO energy levels, resulting in increased hole densities (generated by air oxidation doping) and accelerated hole extraction from photoexcited perovskite. Experimental and theoretical studies highlight the more rigid DBC core, enhancing hole mobility due to …

A novel 3D electromagnetic metamaterial design for Electromagnetically Induced Transparency in THz frequencies is reported. Simulations were done using finite elements method in order to optimize the geometry of the metamaterial. The structure was fabricated using Multiphoton Lithography on high resistivity Silicon substrate and further processed with Electroless Silver Plating to get the highly conductive metallic metamaterial.

Joule

A widely used component of high-efficiency perovskite solar cells (PSCs) is the molecular hole-transport material (HTM) spiro-OMeTAD. This organic solid needs to be p-doped to acquire sufficient hole conductivity. However, the conventional doping method using LiTFSI in the air is slow, sensitive to the environment, and may lead to the deterioration of the PSCs by unintended oxidation or dopant migration. It is thus highly desirable to develop fast doping approaches that avoid exposing the PSC to ambient air and easy-to-move dopant ions. We report here that light absorption by spiro-OMeTAD itself triggers redox photochemistry that has so far been ignored. Strikingly, we found that Y(III) or La(III)-tBP complexes catalyze the symmetry-breaking charge separation of photo-excited spiro-OMeTAD, resulting in the efficient p-doping of the HTM. Using this photo-redox process, we realize PSCs with superior stability over …

Energy & Environmental Materials

The systematic advances in the power conversion efficiency (PCE) and stability of perovskite solar cells (PSCs) have been driven by the developments of perovskite materials, electron transport layer (ETL) materials, and interfacial passivation between the relevant layers. While zinc oxide (ZnO) is a promising ETL in thin film photovoltaics, it is still highly desirable to develop novel synthetic methods that allow both fine‐tuning the versatility of ZnO nanomaterials and improving the ZnO/perovskite interface. Among various inorganic and organic additives, zwitterions have been effectively utilized to passivate the perovskite films. In this vein, we develop novel, well‐characterized betaine‐coated ZnO QDs and use them as an ETL in the planar n‐i‐p PSC architecture, combining the ZnO QDs‐based ETL with the ZnO/perovskite interface passivation by a series of ammonium halides (NH4X, where X = F, Cl, Br). The …

Scientific Reports

We propose an integrated methodology for the design and fabrication of 3D micromodels that are suitable for the pore-scale study of transport processes in macroporous materials. The micromodels, that bear the pore-scale characteristics of sandstone, such as porosity, mean pore size, etc, are designed following a stochastic reconstruction algorithm that allows for fine-tuning the porosity and the correlation length of the spatial distribution of the solid material. We then construct a series of 3D micromodels at very fine resolution (i.e. m) using a state-of-the-art 3D printing infrastructure, specifically a ProJet MJP3600 3D printer, that utilizes the Material Jetting technology. Within the technical constraints of the 3D printer resolution, the fabricated micromodels represent scaled-up replicas of natural sandstones, that are suitable for the study of the scaling between the permeability, the porosity and the mean pore size. The REV- and …

Advanced Materials Interfaces

Interfacial space charges significantly influence transport and recombination of charge carriers in optoelectronic devices. Due to the mixed ionic‐electronic conducting properties of halide perovskites, not only electronic effects, but also ionic interactions at their interfaces need to be considered in the analysis of space charges. Understanding of these interactions and their control is currently missing. This study elucidates the ionic effects on space charge formation at the interface between methylammonium lead iodide (MAPI) and alumina, and its modulation through surface modification using organic molecules. Embedding insulating alumina nanoparticles within MAPI films leads to enhancement of the electronic conductivity. This effect is consistent with the formation of an interfacial inversion layer in MAPI and can only be explained on the basis of ionic interactions. Such an effect is attenuated by surface …

Solar fuels offer a promising approach to provide sustainable fuels by harnessing sunlight. Following a decade of advancement, Cu2O photocathodes are capable of delivering a performance comparable to that of photoelectrodes with established photovoltaic materials. However, considerable bulk charge carrier recombination that is poorly understood still limits further advances in performance. Here we demonstrate performance of Cu2O photocathodes beyond the state-of-the-art by exploiting a new conceptual understanding of carrier recombination and transport in single-crystal Cu2O thin films. Using ambient liquid-phase epitaxy, we present a new method to grow single-crystal Cu2O samples with three crystal orientations. Broadband femtosecond transient reflection spectroscopy measurements were used to quantify anisotropic optoelectronic properties, through which the carrier mobility along the [111] orientation was found to be an order of magnitude higher than those along other orientations. Driven by these findings, we developed a polycrystalline Cu2O photocathode with an extraordinarily pure (111) orientation and (111) terminating facets using a simple and low-cost method, which delivers 7 mA cm− 2 current density (more than 70% improvement compared to that of state-of-the-art electrodeposited devices) at 0.5 V versus a reversible hydrogen electrode under air mass 1.5 G illumination, and stable operation over at least 120 h.

2D Materials

Layered material heterostructures (LMHs) can be used to fabricate electroluminescent devices operating in the visible spectral region. A major advantage of LMH-light emitting diodes (LEDs) is that electroluminescence (EL) emission can be tuned across that of different exciton complexes (e.g. biexcitons, trions, quintons) by controlling the charge density. However, these devices have an EL quantum efficiency as low as~10−4%. Here, we show that the superacid bis-(triuoromethane)sulfonimide (TFSI) treatment of monolayer WS2-LEDs boosts EL quantum efficiency by over one order of magnitude at room temperature. Non-treated devices emit light mainly from negatively charged excitons, while the emission in treated ones predominantly involves radiative recombination of neutral excitons. This paves the way to tunable and efficient LMH-LEDs.

EPJ Applied Metamaterials

A dispersion diagram reconstruction technique is proposed for arbitrarily bianisotropic composite periodic media, which utilizes a previously introduced parameter retrieval technique based on eigenvalue analysis and field averaging. We initially retrieve the effective electromagnetic parameters of a composite periodic medium consisting of Edge-Coupled Split-Ring Resonators (EC-SRRs) via this homogenization technique using alternative integration approaches for the averaging of the field components. Subsequently, we derive the analytical framework for the wave propagation in a homogeneous medium of arbitrary bianisotropy and extract the appropriate equations which solve for the complex propagation constants. We then involve the retrieved effective parameters in these equations and reconstruct the dispersion diagrams for all three orthogonal directions, thereby spanning the whole irreducible Brillouin …

Energy & Environmental Science

Light-induced degradation in metal halide perovskites is a major concern that can potentially hamper the commercialization of perovskite optoelectronic devices. The phenomena viz. ion migration, phase segregation, and defect intolerance are believed to be the factors behind the degradation. However, a detailed mechanistic understanding of how and why light reduces the long-term stability of perovskites is still lacking. Here, by combining multiscale characterization techniques and computational studies, we uncover the role of white light in the surface degradation of state-of-the-art FAPbI3-rich perovskite absorbers (reaching up to 22% PCE in solar cells). We unravel the degradation kinetics and found that white light triggers the chemical degradation of perovskite into secondary phases with higher work function and metallic I–V characteristics. Furthermore, we demonstrate that perovskite degradation is triggered …

Energy & Environmental Materials

The systematic advances in the power conversion efficiency (PCE) and stability of perovskite solar cells (PSCs) have been driven by the developments of perovskite materials, electron transport layer (ETL) materials, and interfacial passivation between the relevant layers. While zinc oxide (ZnO) is a promising ETL in thin film photovoltaics, it is still highly desirable to develop novel synthetic methods that allow both fine‐tuning the versatility of ZnO nanomaterials and improving the ZnO/perovskite interface. Among various inorganic and organic additives, zwitterions have been effectively utilized to passivate the perovskite films. In this vein, we develop novel, well‐characterized betaine‐coated ZnO QDs and use them as an ETL in the planar n‐i‐p PSC architecture, combining the ZnO QDs‐based ETL with the ZnO/perovskite interface passivation by a series of ammonium halides (NH4X, where X = F, Cl, Br). The …

Experimental and theoretical works covering a wide range of photosynthetic and biohydrogen topics, from the primary processes of electron transfer and energy bioconversion to the physiological aspects of photosynthesis and applied aspects of hydrogen production are discussed at the conference. Considerable attention is paid to discussion of structural organization of photosynthetic reaction centers, structure and function of photosystems, artificial photosynthesis, mechanisms of hydrogen production etc. The book will be of interest to researchers and students involved in the study of photosynthesis and bio-hydrogen production

Scientific Reports

A worldwide increase in the prevalence of coral diseases and mortality has been linked to ocean warming due to changes in coral-associated bacterial communities, pathogen virulence, and immune system function. In the Mediterranean basin, the worrying upward temperature trend has already caused recurrent mass mortality events in recent decades. To evaluate how elevated seawater temperatures affect the immune response of a thermophilic coral species, colonies of Astroides calycularis were exposed to environmental (23 °C) or elevated (28 °C) temperatures, and subsequently challenged with bacterial lipopolysaccharides (LPS). Using immunolabeling with specific antibodies, we detected the production of Toll-like receptor 4 (TLR4) and nuclear factor kappa B (NF-kB), molecules involved in coral immune responses, and heat shock protein 70 (HSP70) activity, involved in general responses to thermal …

Scientific Reports

Many nocturnally active fireflies use precisely timed bioluminescent patterns to identify mates, making them especially vulnerable to light pollution. As urbanization continues to brighten the night sky, firefly populations are under constant stress, and close to half of the species are now threatened. Ensuring the survival of firefly biodiversity depends on a large-scale conservation effort to monitor and protect thousands of populations. While species can be identified by their flash patterns, current methods require expert measurement and manual classification and are infeasible given the number and geographic distribution of fireflies. Here we present the application of a recurrent neural network (RNN) for accurate automated firefly flash pattern classification. Using recordings from commodity cameras, we can extract flash trajectories of individuals within a swarm and classify their species with an accuracy of …

Scientific Reports

Publisher Correction: Long‑term application of agronomic management strategies effects on soil organic carbon, energy budgeting, and carbon footprint under rice–wheat cropping system - PMC Back to Top Skip to main content NIH NLM Logo Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation Preview improvements coming to the PMC website in October 2024. Learn More or Try it out now. Search PMC Full-Text Archive Search in PMC Advanced Search User Guide Journal List Scientific Reports PMC10942967 Other Formats PDF (661K) Actions Cite Collections Share Permalink Copy RESOURCES Similar articles Cited by other articles Links to NCBI Databases Journal List Scientific Reports PMC10942967 As a library, NLM provides access to scientific literature. Inclusion in an NLM database does not imply endorsement of, or agreement with, the contents by NLM or the National …

Scientific Reports

In the plains of western North India, traditional rice and wheat cropping systems (RWCS) consume a significant amount of energy and carbon. In order to assess the long-term energy budgets, ecological footprint, and greenhouse gas (GHG) pollutants from RWCS with residual management techniques, field research was conducted which consisted of fourteen treatments that combined various tillage techniques, fertilization methods, and whether or not straw return was present in randomized block design. By altering the formation of aggregates and the distribution of carbon within them, tillage techniques can affect the dynamics of organic carbon in soil and soil microbial activity. The stability of large macro-aggregates (> 2 mm), small macro-aggregates (2.0–2.25 mm), and micro-aggregates in the topsoil were improved by 35.18%, 33.52%, and 25.10%, respectively, over conventional tillage (0–20 cm) using tillage …

Scientific Reports

Honey bees are social insects, and each colony member has unique morphological and physiological traits associated with their social tasks. Previously, we identified a long non-coding RNA from honey bees, termed Nb-1, whose expression in the brain decreases associated with the age-polyethism of workers and is detected in some neurosecretory cells and octopaminergic neurons, suggesting its role in the regulation of worker labor transition. Herein, we investigated its spatially and temporary-regulated/sex-specific expression. Nb-1 was expressed as an abundant maternal RNA during oogenesis and embryogenesis in both sexes. In addition, Nb-1 was expressed preferentially in the proliferating neuroblasts of the mushroom bodies (a higher-order center of the insect brain) in the pupal brains, suggesting its role in embryogenesis and mushroom body development. On the contrary, Nb-1 was expressed in a …

Scientific Reports

The use of hydrogels helpsthe production of plants in drought-stress environments. Thus, this work evaluated using different hydrogels to minimize drought stress in soybean cultivation. The treatments employed two different hydrogels, one already commercialized and the other produced with cashew gum (Anacardium occidentale), five levels (0, 30, 60, 120, and 240 mg pot−1) of the hydrogels, and two levels of drought stress in sandy soil. The growth and yield of soybeans and the levels of macro- and micronutrients in soybeans were evaluated.growth. The use of CG hydrogel promoted 12% increase in protein content in the seeds in the when soybean plants were subjected to drought stress. The levels of 30 mg pot-1, corresponding to 7.5 kg ha−1, improved the ’morphological and productive parametersof the soybeans. The increasing levels of hydrogel promoted the increase in P, K, Ca, Mg, and Fe and reduced …

Scientific Reports

The objective of this study was to evaluate the association of maternal cardiometabolic markers trajectories (glucose, triglycerides (TG), total cholesterol, systolic blood pressure (SBP) and diastolic blood pressure (DBP)) with estimated fetal weight trajectories and birth weight in Mexican pregnant women without medical complications. Cardiometabolic marker trajectories were characterized using group-based trajectory models. Mixed-effect and linear regression models were estimated to assess the association of maternal trajectories with estimated fetal weight and birth weight. The final sample comprised 606 mother–child dyads. Two trajectory groups of maternal cardiometabolic risk indicators during pregnancy were identified (high and low). Fetuses from women with higher values of TG had higher weight gain during pregnancy ( = 24.00 g; 95%CI: 12.9, 35.3), were heavier at the sixth month (=48.24 g; 95%CI: 7.2, 89.7 …

Scientific Reports

In pulmonary inflammation diseases, like COVID-19, lung involvement and inflammation determine the treatment regime. Respiratory inflammation is typically arisen due to the cytokine storm and the leakage of the vessels for immune cells recruitment. Currently, such a situation is detected by the clinical judgment of a specialist or precisely by a chest CT scan. However, the lack of accessibility to the CT machines in many poor medical centers as well as its expensive service, demands more accessible methods for fast and cheap detection of lung inflammation. Here, we have introduced a novel method for tracing the inflammation and lung involvement in patients with pulmonary inflammation, such as COVID-19, by a simple electrolyte detection in their sputum samples. The presence of the electrolyte in the sputum sample results in the fern-like structures after air-drying. These fern patterns are different in the CT …

Scientific Reports

In this paper, a novel wideband antenna with a simple structure and low profile based on spoof surface plasmon polaritons (SSPPs) is proposed. The structure consists of periodically modulated corrugated metal strips as transmission lines, a CPW feed, and a ground metal plate as an antenna reflector. The SSPP transmission line is used to convert quasi-TEM to SSPP mode and achieve optimal impedance matching. The prototype of the end-fire antenna has been designed and fabricated. The simulation results show that this antenna can achieve a gain of 10.19 dB, a bandwidth of 146%, and an efficiency of 90% in a wide operating band from 7 to 45 GHz. The proposed design illustrates great potential that includes high efficiency, good directivity, high gain, wide bandwidth, and easy manufacturing.

Scientific Reports

This study addresses the escalating risk of high-speed railway (HSR) infrastructure in China, amplified by climate warming, increased rainfall, frequent extreme weather, and geohazard events. Leveraging a georeferenced dataset of recent HSR defects obtained through an extensive literature review, we employ machine learning techniques for a quantitative multi-defect risk assessment. Climatic, geomorphological, geohydrological, and anthropogenic variables influencing HSR subgrade safety are identified and ranked. Climatic factors significantly impact frost damage and mud pumping, while geomorphological variables exhibit greater influence on settlement and uplift deformation defects. Notably, frost damage is prevalent in the northeast and northwest, mud pumping along the southeast coast, and settlement and uplift deformation in the northwest and central areas. The generated comprehensive risk map …

Scientific Reports

Although some studies have shown neuroimaging and neuropsychological alterations in post-COVID-19 patients, fewer combined neuroimaging and neuropsychology evaluations of individuals who presented a mild acute infection. Here we investigated cognitive dysfunction and brain changes in a group of mildly infected individuals. We conducted a cross-sectional study of 97 consecutive subjects (median age of 41 years) without current or history of psychiatric symptoms (including anxiety and depression) after a mild infection, with a median of 79 days (and mean of 97 days) after diagnosis of COVID-19. We performed semi-structured interviews, neurological examinations, 3T-MRI scans, and neuropsychological assessments. For MRI analyses, we included a group of non-infected 77 controls. The MRI study included white matter (WM) investigation with diffusion tensor images (DTI) and functional connectivity …

Scientific reports

Three-dimensional facial stereophotogrammetry provides a detailed representation of craniofacial soft tissue without the use of ionizing radiation. While manual annotation of landmarks serves as the current gold standard for cephalometric analysis, it is a time-consuming process and is prone to human error. The aim in this study was to develop and evaluate an automated cephalometric annotation method using a deep learning-based approach. Ten landmarks were manually annotated on 2897 3D facial photographs. The automated landmarking workflow involved two successive DiffusionNet models. The dataset was randomly divided into a training and test dataset. The precision of the workflow was evaluated by calculating the Euclidean distances between the automated and manual landmarks and compared to the intra-observer and inter-observer variability of manual annotation and a semi-automated …

Scientific Reports

Sociopolitical crises causing uncertainty have accumulated in recent years, providing fertile ground for the emergence of conspiracy ideations. Computational models constitute valuable tools for understanding the mechanisms at play in the formation and rigidification of these unshakeable beliefs. Here, the Circular Inference model was used to capture associations between changes in perceptual inference and the dynamics of conspiracy ideations in times of uncertainty. A bistable perception task and conspiracy belief assessment focused on major sociopolitical events were administered to large populations from three polarized countries. We show that when uncertainty peaks, an overweighting of sensory information is associated with conspiracy ideations. Progressively, this exploration strategy gives way to an exploitation strategy in which increased adherence to conspiracy theories is associated with the …

Scientific Reports

Sociopolitical crises causing uncertainty have accumulated in recent years, providing fertile ground for the emergence of conspiracy ideations. Computational models constitute valuable tools for understanding the mechanisms at play in the formation and rigidification of these unshakeable beliefs. Here, the Circular Inference model was used to capture associations between changes in perceptual inference and the dynamics of conspiracy ideations in times of uncertainty. A bistable perception task and conspiracy belief assessment focused on major sociopolitical events were administered to large populations from three polarized countries. We show that when uncertainty peaks, an overweighting of sensory information is associated with conspiracy ideations. Progressively, this exploration strategy gives way to an exploitation strategy in which increased adherence to conspiracy theories is associated with the …

Scientific Reports

This article presents the design of a 2-bit dual-band switchable terahertz absorber using a stacked combination of graphene and vanadium dioxide (VO2) metamaterials. For the first time, the proposed absorber design offers four switchable states by controlling the conductivity of graphene and VO2 metamaterial layers. The lower absorption band is produced by the graphene metamaterial, whereas the upper band is implemented by the VO2 metamaterial pattern. The structure shows two absorption bands (State 11) at 0.745–0.775 THz and 2.3–5.63 THz, when the Fermi graphene level of graphene is 0.2 eV and the VO2 is in the metallic phase. The lower absorption band is turned off, while keeping the upper band (State 01), when the graphene Fermi level is 0 eV and the VO2 layer is in the metallic phase. The upper absorption band is turned off, while preserving the lower absorption band (State 10) by switching …

Scientific Reports

A simple and inexpensive microwave measurement setup based on measurements of magnitudes of transmission properties () is proposed for industrial-based microwave aquametry (moisture or water content) applications. An easy-to-apply calibration procedure based on normalization is implemented to eliminate systematic errors in the measurement system. As a case study, we applied this setup for the quantification of water-adulteration in flower honey. After validating this system by distilled water and pure flower honey measurements, measurements of the pure flower honey with various adulteration percentages () up to 9% are conducted to examine the performance of the measurement setup for quantification of water adulteration. A multi-dimensional fitting procedure is implemented to predict using the proposed inexpensive microwave measurement setup. It is shown that it is possible to quantify …

Scientific Reports

Lida Ajer and Ngalau Gupin are karstic caves situated in the Padang Highlands, western Sumatra, Indonesia. Lida Ajer is best known for yielding fossil evidence that places the arrival of Homo sapiens in Southeast Asia during Marine Isotope Stage 4, one of the earliest records for the region. Ngalau Gupin recently produced the first record of hippopotamid Hexaprotodon on the island, representing the only globally extinct taxon in Pleistocene deposits from Sumatra. Microstratigraphic (micromorphological) analyses were applied to unconsolidated fossil-bearing cave sediments from these two sites. We use micromorphology as part of a micro-contextualised taphonomic approach to identify the diagenetic processes affecting fossils and sediments within these caves, through phases of their depositional history. The fossil-bearing sediments in Lida Ajer have been subjected to a suite of natural sedimentation processes …

Scientific Reports

Multiple sclerosis is a debilitating autoimmune disease, characterized by chronic inflammation of the central nervous system. While the significance of the gut microbiome on multiple sclerosis pathogenesis is established, the underlining mechanisms are unknown. We found that serum levels of the microbial postbiotic tryptophan metabolite indole-3-carboxaldehyde (3-IAld) inversely correlated with disease duration in multiple sclerosis patients. Much like the host-derived tryptophan derivative l-Kynurenine, 3-IAld would bind and activate the Aryl hydrocarbon Receptor (AhR), which, in turn, controls endogenous tryptophan catabolic pathways. As a result, in peripheral lymph nodes, microbial 3-IAld, affected mast-cell tryptophan metabolism, forcing mast cells to produce serotonin via Tph1. We thus propose a protective role for AhR–mast-cell activation driven by the microbiome, whereby natural metabolites or …

Scientific Reports

Placing the origin of an undeciphered script in time is crucial to understanding the invention of writing in human history. Rapa Nui, also known as Easter Island, developed a script, now engraved on fewer than 30 wooden objects, which is still undeciphered. Its origins are also obscure. Central to this issue is whether the script was invented before European travelers reached the island in the eighteenth century AD. Hence direct radiocarbon dating of the wood plays a fundamental role. Until now, only two tablets were directly dated, placing them in the nineteenth c. AD, which does not solve the question of independent invention. Here we radiocarbon-dated four Rongorongo tablets preserved in Rome, Italy. One specimen yielded a unique and secure mid-fifteenth c. date, while the others fall within the nineteenth c. AD. Our results suggest that the use of the script could be placed to a horizon that predates the arrival of …

Scientific Reports

Although oxytocin (OT) plays a role in bonding between heterospecifics and conspecifics, the effects of OT on the formation of such interspecific social behavior have only been investigated between humans and dogs (Canis familiaris). In this study, for comparative evaluation of the effects of OT between dog–human and cat–human social interaction, we investigated the effects of exogenous OT on the behavior of domestic cats (Felis silvestris catus) toward humans. We intranasally administered OT or saline to 30 cats using a nebulizer and recorded their behavior (gaze, touch, vocalization, and proximity). The results showed an interaction between the administration condition and sex for gaze duration. Post hoc analyses revealed a significant increase in gaze in the OT condition in male cats but not in females. There were no significant differences in gaze toward owners and strangers in any condition or sex. The …