Wide-range continuous tuning of the thermal conductivity of La0.5Sr0.5CoO3-δ films via room-temperature ion-gel gating

Bulletin of the American Physical Society

D21. 00005: Dilute Magnetic Moments and their Influence on Electronic Transport in Single-Crystal PdCo 1-x Cr x O 2*

Bulletin of the American Physical Society

W21. 00004: Spin Signal Optimization in Metallic Non-Local Spin Valves via Tuned Interface Resistance*

Nature Communications

Despite their highly anisotropic complex-oxidic nature, certain delafossite compounds (e.g., PdCoO2, PtCoO2) are the most conductive oxides known, for reasons that remain poorly understood. Their room-temperature conductivity can exceed that of Au, while their low-temperature electronic mean-free-paths reach an astonishing 20 μm. It is widely accepted that these materials must be ultrapure to achieve this, although the methods for their growth (which produce only small crystals) are not typically capable of such. Here, we report a different approach to PdCoO2 crystal growth, using chemical vapor transport methods to achieve order-of-magnitude gains in size, the highest structural qualities yet reported, and record residual resistivity ratios ( > 440). Nevertheless, detailed mass spectrometry measurements on these materials reveal that they are not ultrapure in a general sense, typically harboring 100s-of-parts …

Bulletin of the American Physical Society

Artificial spin ice, consisting of nanostructured magnetic elements, provides an excellent playground for exploring many-body phenomena. In our study, we focus on the influence of a complex geometrical transformation and the introduction of a topological defect within a small patch of the classical square ice lattice. By using magnetic imaging techniques, we unveil the existence of preferential magnetic flux channels. These channels persist due to the system's inherent topological nature that leads to a modification of the energy landscape. This topological transformation offers an exciting avenue for designing and fine-tuning controllable emergent flux channels, creating new opportunities for further research.* Work at Yale University was funded by the US Department of Energy (DOE), Office of Basic Energy Sciences, Materials Sciences and Engineering Division under Grant No. DE-SC0020162. Work at the …

Physical Review B

Pr-containing perovskite cobaltites exhibit unusual valence transitions, coupled to coincident structural, spin-state, and metal-insulator transitions. Heteroepitaxial strain was recently used to control these phenomena in the model (Pr 1− y Y y) 1− x Ca x Co O 3− δ system, stabilizing a nonmagnetic insulating phase under compression (with a room-temperature valence/spin-state/metal-insulator transition) and a ferromagnetic (FM) metallic phase under tension, thus exposing a potential spin-state quantum-critical point. The latter has been proposed in cobaltites and can be probed in this system as a function of a disorder-free variable (strain). We study this here via thickness-dependent strain relaxation in compressive SrLaAl O 4 (001)/(Pr 0.85 Y 0.15) 0.70 Ca 0.30 Co O 3− δ epitaxial thin films to quasicontinuously probe structural, electronic, and magnetic behaviors across the nonmagnetic-insulator/FM-metal …

Bulletin of the American Physical Society

K21. 00003: Decoupling the spin-state and insulator-metal transitions via heteroepitaxial strain in LaCoO 3-δ*

Bulletin of the American Physical Society

K21. 00004: Oral: Anomalous Transport and Interfacial Charge Transfer in Pr-based Cobaltite Heterostructures*

ACS Applied Materials & Interfaces

Perovskite cobaltites have emerged as archetypes for electrochemical control of materials properties in electrolyte-gate devices. Voltage-driven redox cycling can be performed between fully oxygenated perovskite and oxygen-vacancy-ordered brownmillerite phases, enabling exceptional modulation of the crystal structure, electronic transport, thermal transport, magnetism, and optical properties. The vast majority of studies, however, have focused heavily on the perovskite and brownmillerite end points. In contrast, here we focus on hysteresis and reversibility across the entire perovskite ↔ brownmillerite topotactic transformation, combining gate-voltage hysteresis loops, minor hysteresis loops, quantitative operando synchrotron X-ray diffraction, and temperature-dependent (magneto)transport, on ion-gel-gated ultrathin (10-unit-cell) epitaxial La0.5Sr0.5CoO3−δ films. Gate-voltage hysteresis loops combined with …

Bulletin of the American Physical Society

D21. 00007: Thermal and Magnetic Properties of the Metallic Delafossite Triangular-Lattice Antiferromagnet PdCrO 2*

APL Materials

Epitaxial cobaltites have emerged as exemplary materials for electrochemical gating, in large part due to their topotactic perovskite (P)↔ brownmillerite (BM) transformations. SrCoO3− δ, for example, can be cycled between metallic ferromagnetic P SrCoO3 and insulating BM SrCoO2. 5, realizing exceptional modulation of electronic, thermal, and optical properties. It is often presumed that such cycling also generates ferromagnetic–antiferromagnetic (F-AF) modulation due to the G-type AF order in bulk SrCoO2. 5. Little is understood about magnetism in thin-film BM SrCoO2. 5, however, meaning that the true magnetic property modulation is unclear. We address this here through a neutron diffraction study of BM La1− xSrxCoO2. 5 films at x= 0.5 and 1.0. Lightly compressively strained SrCoO2. 5 films are shown to retain G-type AF order, albeit with suppressed Néel temperature (∼ 340 K). Of high interest for AF …

Physical Review Materials

The pyrite-structure transition-metal disulfide Ni S 2 is in principle a model cubic antiferromagnetic Mott insulator that can be doped through insulator-metal transitions with both electrons and holes (in Ni 1–x Cu x S 2 and Ni 1–x Co x S 2), eventually inducing superconductivity and ferromagnetism, respectively. Magnetism and transport have proven challenging to understand in Ni S 2, however. The antiferromagnetic spin structure below∼ 39 K is complex due to frustration, while unexplained weak ferromagnetism emerges below∼ 30 K. Surface conduction is also now understood to dominate in Ni S 2 at low temperatures, raising questions about the interpretation of decades of prior data. Here, we present a complete study of the surface magnetotransport phenomena that emerge at low temperatures in high-quality single-crystal Ni S 2, which turn out to be strikingly rich. On cooling, isotropic magnetoresistance due …

Materials with tunable infrared refractive index changes have enabled active metasurfaces for novel control of optical circuits, thermal radiation, and more. Ion-gel-gated epitaxial films of the perovskite cobaltite La1− xSrxCoO3− ???? (LSCO) with 0.00≤ x≤ 0.70 offer a new route to significant, voltage-tuned, nonvolatile refractive index modulation for infrared active metasurfaces, shown here through Kramers–Kronig-consistent dispersion models, structural and electronic transport characterization, and electromagnetic simulations before and after electrochemical reduction. As-grown perovskite films are high-index insulators for x< 0.18 but lossy metals for x> 0.18, due to a percolation insulator-metal transition. Positive-voltage gating of LSCO transistors with x> 0.18 reveals a metal-insulator transition from the metallic perovskite phase to a high-index (n> 2.5), low-loss insulating phase, accompanied by a perovskite to oxygen-vacancy-ordered brownmillerite transformation at high x. At x< 0.18, despite nominally insulating character, the LSCO films undergo remarkable refractive index changes to another lower-index, lower-loss insulating perovskite state with ????n> 0.6. In simulations of plasmonic metasurfaces, these metal-insulator and insulator-insulator transitions support significant, varied mid-infrared reflectance modulation, thus framing electrochemically gated LSCO as a diverse library of room-temperature phase-change materials for applications including dynamic thermal imaging, camouflage, and optical memories.

APS March Meeting Abstracts

We have experimentally investigated and imaged how the topology of a frustrated artificial spin ice nanomagnet array can affect and constrain its kinetics. Studying vertex-frustrated Santa Fe artificial spin ice, in which magnetic excitations are correlated in thermally active one-dimensional emergent strings, we imaged the thermally-driven motion of these emergent string excitations in real time. At high temperatures, the string kinetics include topologically complex changes, which are highly constrained at lower temperatures. This system provides an unusually accessible venue in which to study the effects of topology on ergodicity through direct measurement of the thermal kinetics.

Nanoscale

The coexistence of different properties in the same material often results in exciting physical effects. At low temperatures, the pyrite transition-metal disulphide NiS2 hosts both antiferromagnetic and weak ferromagnetic orders, along with surface metallicity dominating its electronic transport. The interplay between such a complex magnetic structure and surface-dominated conduction in NiS2, however, is still not understood. A possible reason for this limited understanding is that NiS2 has been available primarily in bulk single-crystal form, which makes it difficult to perform studies combining magnetometry and transport measurements with high spatial resolution. Here, NiS2 nanoflakes are produced via mechanical cleaving and exfoliation of NiS2 single crystals and their properties are studied on a local (micron-size) scale. Strongly field-asymmetric magnetotransport features are found at low temperatures, which …

Physical review letters

We study the collective behavior of interacting arrays of nanomagnetic tripods. These objects have six discrete moment states, in contrast to the usual two states of an Ising-like moment. Our experimental data demonstrate that triangular lattice arrays form a “tripod ice” that exhibits charge ordering among the effective vertex magnetic charges, in direct analogy to artificial kagome spin ice. The results indicate that the interacting tripods have effective moments that act as emergent local variables, with strong connections to the well-studied Potts and clock models. In addition, the tripod moments display a tendency toward a nearest neighbor alignment in our thermalized samples that separates this system from kagome spin ice. Our results open a path toward the study of the collective behavior of nonbinary moments that is unavailable in other physical systems.

Science

Ergodic kinetics, which are critical to equilibrium thermodynamics, can be constrained by a system’s topology. We studied a model nanomagnetic array in which such constraints visibly affect the behavior of the magnetic moments. In this system, magnetic excitations connect into thermally active one-dimensional strings whose motion can be imaged in real time. At high temperatures, our data showed the merging, breaking, and reconnecting of strings, resulting in the system transitioning between topologically distinct configurations. Below a crossover temperature, the string motion is dominated by simple changes in length and shape. In this low-temperature regime, the system is energetically stable because of its inability to explore all possible topological configurations. This kinetic crossover suggests a generalizable conception of topologically broken ergodicity and limited equilibration.

APS March Meeting Abstracts

Artificial spin ice (ASI) systems composed of arrays of frustrated interacting nanomagnets offer a valuable platform for designing and exploring collective magnetic phenomena. However, most ASI geometries explored to date employ stadium-shaped magnetic islands with Ising-like character, ie, the island moments are binary. We report the study of an artificial spin system based on a new type of artificial moment: a three-fold symmetric Y-shape island. The resulting non-binary nanomagnetic building block effectively behaves as a multipolar magnetic element, giving rise to behavior akin to a Potts-like 6-state clock model. These new magnetic objects enable the exploration of a variety of novel magnetic phases, opening a path to new collective phenomena and kinetics beyond the traditional ASI binary moment systems.

Advanced Optical Materials

Materials with tunable infrared refractive index changes have enabled active metasurfaces for novel control of optical circuits, thermal radiation, and more. Ion-gel-gated epitaxial films of the perovskite cobaltite La 1− x Sr x CoO 3− δ (LSCO) with 0.00≤ x≤ 0.70 offer a new route to significant, voltage-tuned, nonvolatile refractive index modulation for infrared active metasurfaces, shown here through Kramers–Kronig-consistent dispersion models, structural and electronic transport characterization, and electromagnetic simulations before and after electrochemical reduction. As-grown perovskite films are high-index insulators for x< 0.18 but lossy metals for x> 0.18, due to a percolation insulator-metal transition. Positive-voltage gating of LSCO transistors with x> 0.18 reveals a metal-insulator transition from the metallic perovskite phase to a high-index (n> 2.5), low-loss insulating phase, accompanied by a perovskite to oxygen-vacancy-ordered brownmillerite transformation at high x. At x< 0.18, despite nominally insulating character, the LSCO films undergo remarkable refractive index changes to another lower-index, lower-loss insulating perovskite state with Δn> 0.6. In simulations of plasmonic metasurfaces, these metal-insulator and insulator-insulator transitions support significant, varied mid-infrared reflectance modulation, thus framing electrochemically gated LSCO as a diverse library of room-temperature phase-change materials for applications including dynamic thermal imaging, camouflage, and optical memories.

APL Materials

For applications such as spin accumulation sensors for next-generation hard disk drive read heads, and for fundamental research, it is desirable to increase the spin signal in metallic non-local spin valves, which are central devices in spintronics. To this end, here, we report on the integration of high-spin-polarization Co–Fe binary alloy ferromagnetic injectors and detectors in Al-based non-local spin valves. Room-temperature deposition on amorphous substrates from an alloy target is shown to generate smooth, polycrystalline (110-textured), solid-solution body-centered-cubic Co 75 Fe 25 films, which we characterize by energy dispersive x-ray spectroscopy, x-ray diffraction, x-ray reflectivity, atomic force microscopy, and electronic transport. Simple integration into transparent-interface Al non-local spin valves is then shown to realize up to a factor of∼ 5 enhancement of the spin signal relative to Co, with full …

Nature Communications

Increased de novo lipogenesis (DNL) in white adipose tissue is associated with insulin sensitivity. Under both Normal-Chow-Diet and High-Fat-Diet, mice expressing a kinase inactive Cyclin-dependent kinase 6 (Cdk6) allele (K43M) display an increase in DNL in visceral white adipose tissues (VAT) as compared to wild type mice (WT), accompanied by markedly increased lipogenic transcriptional factor Carbohydrate-responsive element-binding proteins (CHREBP) and lipogenic enzymes in VAT but not in the liver. Treatment of WT mice under HFD with a CDK6 inhibitor recapitulates the phenotypes observed in K43M mice. Mechanistically, CDK6 phosphorylates AMP-activated protein kinase, leading to phosphorylation and inactivation of acetyl-CoA carboxylase, a key enzyme in DNL. CDK6 also phosphorylates CHREBP thus preventing its entry into the nucleus. Ablation of runt related transcription factor 1 in …

Nature Communications

Surface defects in semiconducting materials, though they have been widely studied, remain a prominent source of loss in optoelectronic devices; here we sought a new angle of approach, looking into the dynamic roles played by surface defects under atmospheric stressors and their chemical passivants in the lifetime of optoelectronic materials. We find that surface defects possess properties distinct from those of bulk defects. ab initio molecular dynamics simulations reveal a previously overlooked reversible degradation mechanism mediated by hydrogen vacancies. We find that dynamic surface adsorption affinity (DAA) relative to surface treatment ligands is a surrogate for passivation efficacy, a more strongly-correlated feature than is the static binding strength emphasized in prior reports. This guides us to design targeted passivator ligands with high molecular polarity: for example, 4-aminobutylphosphonic acid …

Nature Communications

Kinks define boundaries between distinct configurations of a material. In the context of mechanical metamaterials, kinks have recently been shown to underpin logic, shape-changing and locomotion functionalities. So far such kinks propagate by virtue of inertia or of an external load. Here, we discover the emergence of propagating kinks in purely dissipative kirigami. To this end, we create kirigami that shape-change into different textures depending on how fast they are stretched. We find that if we stretch fast and wait, the viscoelastic kirigami can eventually snap from one texture to another. Crucially, such a snapping instability occurs in a sequence and a propagating diffusive kink emerges. As such, it mimics the slow sequential folding observed in biological systems, e.g., Mimosa Pudica. We finally demonstrate that diffusive kinks can be harnessed for basic machine-like functionalities, such as sensing, dynamic …

Nature Communications

Poly-γ-glutamate tails are a distinctive feature of archaeal, bacterial, and eukaryotic cofactors, including the folates and F420. Despite decades of research, key mechanistic questions remain as to how enzymes successively add glutamates to poly-γ-glutamate chains while maintaining cofactor specificity. Here, we show how poly-γ-glutamylation of folate and F420 by folylpolyglutamate synthases and γ-glutamyl ligases, non-homologous enzymes, occurs via processive addition of L-glutamate onto growing γ-glutamyl chain termini. We further reveal structural snapshots of the archaeal γ-glutamyl ligase (CofE) in action, crucially including a bulged-chain product that shows how the cofactor is retained while successive glutamates are added to the chain terminus. This bulging substrate model of processive poly-γ-glutamylation by terminal extension is arguably ubiquitous in such biopolymerisation reactions, including …

Nature Communications

Genome-wide association studies (GWAS) have identified more than 200 common genetic variants independently associated with colorectal cancer (CRC) risk, but the causal variants and target genes are mostly unknown. We sought to fine-map all known CRC risk loci using GWAS data from 100,204 cases and 154,587 controls of East Asian and European ancestry. Our stepwise conditional analyses revealed 238 independent association signals of CRC risk, each with a set of credible causal variants (CCVs), of which 28 signals had a single CCV. Our cis-eQTL/mQTL and colocalization analyses using colorectal tissue-specific transcriptome and methylome data separately from 1299 and 321 individuals, along with functional genomic investigation, uncovered 136 putative CRC susceptibility genes, including 56 genes not previously reported. Analyses of single-cell RNA-seq data from colorectal tissues revealed 17 …

Nature Communications

Designing complex synthetic materials for enzyme immobilization could unlock the utility of biocatalysis in extreme environments. Inspired by biology, we investigate the use of random copolymer brushes as dynamic immobilization supports that enable supra-biological catalytic performance of immobilized enzymes. This is demonstrated by immobilizing Bacillus subtilis Lipase A on brushes doped with aromatic moieties, which can interact with the lipase through multiple non-covalent interactions. Incorporation of aromatic groups leads to a 50 °C increase in the optimal temperature of lipase, as well as a 50-fold enhancement in enzyme activity. Single-molecule FRET studies reveal that these supports act as biomimetic chaperones by promoting enzyme refolding and stabilizing the enzyme’s folded and catalytically active state. This effect is diminished when aromatic residues are mutated out, suggesting the …

Nature Communications

We introduce a computational approach for the design of target-specific peptides. Our method integrates a Gated Recurrent Unit-based Variational Autoencoder with Rosetta FlexPepDock for peptide sequence generation and binding affinity assessment. Subsequently, molecular dynamics simulations are employed to narrow down the selection of peptides for experimental assays. We apply this computational strategy to design peptide inhibitors that specifically target β-catenin and NF-κB essential modulator. Among the twelve β-catenin inhibitors, six exhibit improved binding affinity compared to the parent peptide. Notably, the best C-terminal peptide binds β-catenin with an IC50 of 0.010 ± 0.06 μM, which is 15-fold better than the parent peptide. For NF-κB essential modulator, two of the four tested peptides display substantially enhanced binding compared to the parent peptide. Collectively, this study …

Nature Communications

Defect scattering is well known to suppress thermal transport. In this study, however, we perform both molecular dynamics and Boltzmann transport equation calculations, to demonstrate that introducing defect scattering in nanoscale heating zone could surprisingly enhance thermal conductance of the system by up to 75%. We further reveal that the heating zone without defects yields directional nonequilibrium with overpopulated oblique-propagating phonons which suppress thermal transport, while introducing defects redirect phonons randomly to restore directional equilibrium, thereby enhancing thermal conductance. We demonstrate that defect scattering can enable such thermal transport enhancement in a wide range of temperatures, materials, and sizes, and offer an unconventional strategy for enhancing thermal transport via the manipulation of phonon directional nonequilibrium.

Nature Communications

Hepatic encephalopathy is a neuropsychiatric complication of liver disease which is partly associated with elevated ammonemia. Urea hydrolysis by urease-producing bacteria in the colon is often mentioned as one of the main routes of ammonia production in the body, yet research on treatments targeting bacterial ureases in hepatic encephalopathy is limited. Herein we report a hydroxamate-based urease inhibitor, 2-octynohydroxamic acid, exhibiting improved in vitro potency compared to hydroxamic acids that were previously investigated for hepatic encephalopathy. 2-octynohydroxamic acid shows low cytotoxic and mutagenic potential within a micromolar concentration range as well as reduces ammonemia in rodent models of liver disease. Furthermore, 2-octynohydroxamic acid treatment decreases cerebellar glutamine, a product of ammonia metabolism, in male bile duct ligated rats. A prototype colonic …

Nature Communications

The Sabatier principle is widely explored in heterogeneous catalysis, graphically depicted in volcano plots. The most desirable activity is located at the peak of the volcano, and further advances in activity past this optimum are possible by designing a catalyst that circumvents the limitation entailed by the Sabatier principle. Herein, by density functional theory calculations, we discovered an unusual Sabatier principle on high entropy alloy (HEA) surface, distinguishing the “just right” (ΔGH* = 0 eV) in the Sabatier principle of hydrogen evolution reaction (HER). A new descriptor was proposed to design HEA catalysts for HER. As a proof-of-concept, the synthesized PtFeCoNiCu HEA catalyst endows a high catalytic performance for HER with an overpotential of 10.8 mV at −10 mA cm−2 and 4.6 times higher intrinsic activity over the state-of-the-art Pt/C. Moreover, the unusual Sabatier principle on HEA catalysts can …

Nature Communications

Heart failure with preserved ejection fraction (HFpEF) poses therapeutic challenges due to the limited treatment options. Building upon our previous research that demonstrates the efficacy of histone deacetylase 6 (HDAC6) inhibition in a genetic cardiomyopathy model, we investigate HDAC6’s role in HFpEF due to their shared mechanisms of inflammation and metabolism. Here, we show that inhibiting HDAC6 with TYA-018 effectively reverses established heart failure and its associated symptoms in male HFpEF mouse models. Additionally, in male mice lacking Hdac6 gene, HFpEF progression is delayed and they are resistant to TYA-018’s effects. The efficacy of TYA-018 is comparable to a sodium-glucose cotransporter 2 (SGLT2) inhibitor, and the combination shows enhanced effects. Mechanistically, TYA-018 restores gene expression related to hypertrophy, fibrosis, and mitochondrial energy production in …

Nature Communications

Bacteria have evolved diverse antiviral defence mechanisms to protect themselves against phage infection. Phages integrated into bacterial chromosomes, known as prophages, also encode defences that protect the bacterial hosts in which they reside. Here, we identify a type of anti-phage defence that interferes with the virion assembly pathway of invading phages. The protein that mediates this defence, which we call Tab (for ‘Tail assembly blocker’), is constitutively expressed from a Pseudomonas aeruginosa prophage. Tab allows the invading phage replication cycle to proceed, but blocks assembly of the phage tail, thus preventing formation of infectious virions. While the infected cell dies through the activity of the replicating phage lysis proteins, there is no release of infectious phage progeny, and the bacterial community is thereby protected from a phage epidemic. Prophages expressing Tab are not inhibited …

Nature Communications

In higher eukaryotes, a single DOT1 histone H3 lysine 79 (H3K79) methyltransferase processively produces H3K79me2/me3 through histone H2B mono-ubiquitin interaction, while the kinetoplastid Trypanosoma brucei di-methyltransferase DOT1A and tri-methyltransferase DOT1B efficiently methylate the homologous H3K76 without H2B mono-ubiquitination. Based on structural and biochemical analyses of DOT1A, we identify key residues in the methyltransferase motifs VI and X for efficient ubiquitin-independent H3K76 methylation in kinetoplastids. Substitution of a basic to an acidic residue within motif VI (Gx6K) is essential to stabilize the DOT1A enzyme-substrate complex, while substitution of the motif X sequence VYGE by CAKS renders a rigid active-site loop flexible, implying a distinct mechanism of substrate recognition. We further reveal distinct methylation kinetics and substrate preferences of DOT1A …

Nature communications

Hormones mediate long-range cell communication and play vital roles in physiology, metabolism, and health. Traditionally, endocrinologists have focused on one hormone or organ system at a time. Yet, hormone signaling by its very nature connects cells of different organs and involves crosstalk of different hormones. Here, we leverage the organism-wide single cell transcriptional atlas of a non-human primate, the mouse lemur (Microcebus murinus), to systematically map source and target cells for 84 classes of hormones. This work uncovers previously-uncharacterized sites of hormone regulation, and shows that the hormonal signaling network is densely connected, decentralized, and rich in feedback loops. Evolutionary comparisons of hormonal genes and their expression patterns show that mouse lemur better models human hormonal signaling than mouse, at both the genomic and transcriptomic levels, and …

Nature Communications

The lack of data democratization and information leakage from trained models hinder the development and acceptance of robust deep learning-based healthcare solutions. This paper argues that irreversible data encoding can provide an effective solution to achieve data democratization without violating the privacy constraints imposed on healthcare data and clinical models. An ideal encoding framework transforms the data into a new space where it is imperceptible to a manual or computational inspection. However, encoded data should preserve the semantics of the original data such that deep learning models can be trained effectively. This paper hypothesizes the characteristics of the desired encoding framework and then exploits random projections and random quantum encoding to realize this framework for dense and longitudinal or time-series data. Experimental evaluation highlights that models trained on …

Nature Communications

Cluster randomized trials are often used to study large-scale public health interventions. In large trials, even small improvements in statistical efficiency can have profound impacts on the required sample size and cost. Location integrates many socio-demographic and environmental characteristics into a single, readily available feature. Here we show that pair matching by geographic location leads to substantial gains in statistical efficiency for 14 child health outcomes that span growth, development, and infectious disease through a re-analysis of two large-scale trials of nutritional and environmental interventions in Bangladesh and Kenya. Relative efficiencies from pair matching are ≥1.1 for all outcomes and regularly exceed 2.0, meaning an unmatched trial would need to enroll at least twice as many clusters to achieve the same level of precision as the geographically pair matched design. We also show that …

Nature Communications

Many diarrhea-causing pathogens are climate-sensitive, and populations with the lowest socioeconomic position (SEP) are often most vulnerable to climate-related transmission. Household Water, Sanitation, and Handwashing (WASH) interventions constitute one potential effective strategy to reduce child diarrhea, especially among low-income households. Capitalizing on a cluster randomized trial population (360 clusters, 4941 children with 8440 measurements) in rural Bangladesh, one of the world’s most climate-sensitive regions, we show that improved WASH substantially reduces diarrhea risk with largest benefits among children with lowest SEP and during the monsoon season. We extrapolated trial results to rural Bangladesh regions using high-resolution geospatial layers to identify areas most likely to benefit. Scaling up a similar intervention could prevent an estimated 734 (95% CI 385, 1085) cases per …

Nature Communications

Dimethyl fumarate (DMF) inhibits inflammasome-mediated inflammation and has been proposed as a treatment for patients hospitalised with COVID-19. This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing multiple treatments in patients hospitalised for COVID-19 (NCT04381936, ISRCTN50189673). In this assessment of DMF performed at 27 UK hospitals, adults were randomly allocated (1:1) to either usual standard of care alone or usual standard of care plus DMF. The primary outcome was clinical status on day 5 measured on a seven-point ordinal scale. Secondary outcomes were time to sustained improvement in clinical status, time to discharge, day 5 peripheral blood oxygenation, day 5 C-reactive protein, and improvement in day 10 clinical status. Between 2 March 2021 and 18 November 2021, 713 patients were enroled in the …

Nature Communications

Traditional histochemical staining of post-mortem samples often confronts inferior staining quality due to autolysis caused by delayed fixation of cadaver tissue, and such chemical staining procedures covering large tissue areas demand substantial labor, cost and time. Here, we demonstrate virtual staining of autopsy tissue using a trained neural network to rapidly transform autofluorescence images of label-free autopsy tissue sections into brightfield equivalent images, matching hematoxylin and eosin (H&E) stained versions of the same samples. The trained model can effectively accentuate nuclear, cytoplasmic and extracellular features in new autopsy tissue samples that experienced severe autolysis, such as COVID-19 samples never seen before, where the traditional histochemical staining fails to provide consistent staining quality. This virtual autopsy staining technique provides a rapid and resource-efficient …

Nature Communications

Van der Waals semiconductors exemplified by two-dimensional transition-metal dichalcogenides have promised next-generation atomically thin optoelectronics. Boosting their interaction with light is vital for practical applications, especially in the quantum regime where ultrastrong coupling is highly demanded but not yet realized. Here we report ultrastrong exciton-plasmon coupling at room temperature in tungsten disulfide (WS2) layers loaded with a random multi-singular plasmonic metasurface deposited on a flexible polymer substrate. Different from seeking perfect metals or high-quality resonators, we create a unique type of metasurface with a dense array of singularities that can support nanometre-sized plasmonic hotspots to which several WS2 excitons coherently interact. The associated normalized coupling strength is 0.12 for monolayer WS2 and can be up to 0.164 for quadrilayers, showcasing the …