Browse Articles

Growth of monolayer 1T′-WTe2 with a nearly complete coverage

Monolayer WTe2, known for its intriguing properties as a quantum spin Hall insulator, presents significant challenges for high-quality epitaxial film growth. These difficulties primarily arise from the low mobility of W on the substrate and the reduced reaction rate between W and Te. This study addresses these challenges by employing a low-temperature deposition technique combined with the introduction of a Te buffer layer to mitigate these limitations. High-quality monolayer 1T′-WTe2 with nearly complete coverage has been grown on the SrTiO3 (100) substrate. Furthermore, scanning tunneling microscopy/spectroscopy demonstrates the presence of random domain orientations and variations in gap size within the monolayer WTe2. This approach offers a solution to the primary obstacles in WTe2 epitaxial growth and may be extended to other transition metal dichalcogenides.

Hybrid-contact Schottky-barrier IGZO thin-film transistors with low barrier sensitivity and high stability

In this work, we investigated the electrical characteristics of Schottky-barrier indium–gallium–zinc oxide (IGZO) thin-film transistors (SBTFTs) by simulation and experiment. The effects of barrier height and channel layer thickness on the electrical properties of hybrid-contact vs single-contact SBTFTs were systematically explored via simulation. The results showed that devices utilizing hybrid-contact architectures exhibit higher output currents and are much less sensitive to variations in barrier height compared to single-contact devices, implying that these devices can more easily achieve consistent electrical properties. Experimentally, hybrid-contact IGZO SBTFTs were fabricated using chemically stable cobalt (Co) as the source/drain electrodes. The devices, utilizing an optimized two-step annealing process, exhibited ultra-small hysteresis and excellent electrical stability under both negative bias illumination temperature stress and positive bias temperature stress. The underlying mechanism responsible for the suppressed hysteresis was thoroughly analyzed. This work opens up a feasible way toward fabricating low-cost metal-oxide SBTFTs with minimized barrier sensitivity and high stability.

Tunable skyrmion–antiskyrmion dynamics in Co/Pt nanocontacts for spintronic applications

Magnetic skyrmions are topologically protected quasiparticles and have drawn much attention because of their potential applications in next-generation spintronics devices. Their inherent topological stability, nanoscale size, and efficient manipulation via spin currents make them promising candidates for high-density data storage and advanced computing paradigms. We micromagnetically investigate the nucleation dynamics of magnetic skyrmion pairs excited underneath two 30 nm nanocontacts with varying separations on top of an extended Co/Pt bilayer thin film. At close separation of 100 nm, the magnetization configurations strongly interact, giving rise to the formation of stable merged skyrmion states. As the separation increases beyond 200 nm, topologically distinct metastable configurations emerge, including the coexistence of tunable skyrmion–antiskyrmion pairs through Dzyaloshinskii–Moriya interaction strengths and current pulse amplitudes. These metastable states eventually relax into two stable skyrmions that can be independently toggled ON and OFF using a weak in-plane magnetic field, enabling complex logic operations and more flexible circuit designs. Beyond the fundamental interest in skyrmion interaction dynamics, the independent control of skyrmion–antiskyrmion states holds promise for next-generation spintronic devices, with potential applications in memory, logic, and computing.

Charge transfer in transition metal dichalcogenide alloy heterostructures

Two-dimensional (2D) transition metal dichalcogenides and their alloys provide a unique platform for exploring interlayer charge transfer in van der Waals heterostructures. These structures are crucial for advancing the next-generation electronic, optoelectronic, and quantum devices. In this study, interlayer charge transfer in heterostructures composed of MoSe2, MoS2, and their alloy, MoSSe, is investigated using transient absorption, Raman, and photoluminescence spectroscopy. The experimental results reveal that electron transfer in the alloy heterostructures, MoSSe/MoS2 and MoSe2/MoSSe, is faster than in the pure MoSe2/MoS2 heterostructure, despite the smaller conduction band offsets of the alloy systems. Raman spectroscopy confirms that alloy layers support phonon modes matching those of the pure layers, aligning with theoretical models of phonon-assisted interlayer charge transfer. Additionally, efficient hole transfer is observed in both alloy heterostructures. The findings suggest transition metal dichalcogenides alloys can be used for engineering heterostructures with desired charge transfer properties. By leveraging compositionally tunable band gaps and optical properties, alloy-based heterostructures offer opportunities for designing tailored materials suitable for diverse applications such as photodetectors, light-emitting devices, and flexible electronics. Moreover, the ultrafast charge transfer observed in these systems provides insights into the fundamental mechanisms governing interlayer interactions in 2D materials.

Quasi-homoepitaxy of hexagonal boron nitride on its own interfacial insertion monolayer

We present an approach to improve the quality of hexagonal boron nitride (hBN) epilayer with a quasi-homoepitaxy mode through the utilization of a hBN interfacial insertion monolayer by using metal-organic chemical vapor deposition. First-principles calculations demonstrate that the insertion of hBN monolayer can not only eliminate the interaction from hetero-substrate but also enhance the surface migration rate during epitaxy. As a result with epitaxial growth, the reduction of initial nucleation density of hBN domains is observed, and meanwhile, the release of misfit stress and higher crystal quality are obtained. Ultimately, this research provides a quasi-homoepitaxial strategy of hBN on arbitrary hetero-substrate.

Cell enlargement modulated by GATA4 and YAP instructs the senescence-associated secretory phenotype

A biodegradable and restorative peripheral neural interface for the interrogation of neuropathic injuries

SGK1 drives hippocampal demyelination and diabetes-associated cognitive dysfunction in mice

Biochemical analyses of cystatin-C dimers and cathepsin-B reveals a trypsin-driven feedback mechanism in acute pancreatitis

Abstract Acute pancreatitis (AP) is characterised by self-digestion of the pancreas by its own proteases. This pathophysiological initiating event in AP occurs inside pancreatic acinar cells where intrapancreatic trypsinogen becomes prematurely activated by cathepsin B (CTSB), and induces the digestive protease cascade, while cathepsin L (CTSL) degrades trypsin and trypsinogen and therefore prevents the development of AP. These proteases are located in the secretory compartment of acinar cells together with cystatin C (CST3), an endogenous inhibitor of CTSB and CTSL. The results are based on detailed biochemical analysis, site-directed mutagenesis and molecular dynamics simulations in combination with an experimental disease model of AP using CST3 deficient mice. This identifies that CST3 is a critical regulator of CTSB and CTSL activity during AP. CST3 deficient mice show a higher intracellular CTSB activity resulting in elevated trypsinogen activation accompanied by an increased disease severity. This reveals that CST3 can be cleaved by trypsin disabling the inhibition of CTSB, but not of CTSL. Furthermore, dimerised CST3 enhances the CTSB activity by binding to an allosteric pocket specific to the CTSB structure. CST3 shifts from an inhibitor to an activator of CTSB and therefore fuels the intrapancreatic protease cascade during the onset of AP.

Resolving discrepancies between chimeric and multiplicative measures of higher-order epistasis

Abstract Epistasis - the interaction between alleles at different genetic loci - plays a fundamental role in biology. However, several recent approaches quantify epistasis using a chimeric formula that measures deviations from a multiplicative fitness model on an additive scale, thus mixing two scales. Here, we show that for pairwise interactions, the chimeric formula yields a different magnitude but the same sign of epistasis compared to the multiplicative formula that measures both fitness and deviations on a multiplicative scale. However, for higher-order interactions, we show that the chimeric formula can have both different magnitude and sign compared to the multiplicative formula. We resolve these inconsistencies by deriving mathematical relationships between the different epistasis formulae and different parametrizations of the multivariate Bernoulli distribution. We argue that the chimeric formula does not appropriately model interactions between the Bernoulli random variables. In simulations, we show that the chimeric formula is less accurate than the classical multiplicative/additive epistasis formulae and may falsely detect higher-order epistasis. Analyzing multi-gene knockouts in yeast, multi-way drug interactions in E. coli, and deep mutational scanning of several proteins, we find that approximately 10% to 60% of inferred higher-order interactions change sign using the multiplicative/additive formula compared to the chimeric formula.

Author Correction: Hallmarks of a genomically distinct subclass of head and neck cancer

Effectiveness of strain and dopants on breaking the activity-stability trade-off of RuO2 acidic oxygen evolution electrocatalysts

A roadmap to precision medicine through post-genomic electronic medical records

Author Correction: Acute particulate matter exposure diminishes executive cognitive functioning after four hours regardless of inhalation pathway

Impact of household size and co-resident multimorbidity on unplanned hospitalisation and transition to care home

Abstract The ability to manage ill health and care needs might be affected by who a person lives with. This study examined how the risk of unplanned hospitalisation and transition to living in a care home varied according to household size and co-resident multimorbidity. Here we show results from a cohort study using  Welsh nationwide linked healthcare and census data, that employed multilevel multistate models to account for the competing risk of death and clustering within households. The highest rates of unplanned hospitalisation and care home transition were in those living alone. Event rates were lower in all shared households and lowest when co-residents did not have multimorbidity. These differences were more substantial for care home transition. Therefore, living alone or with co-residents with multimorbidity poses additional risk for unplanned hospitalisation and care home transition beyond an individual’s sociodemographic and health characteristics. Understanding the mechanisms behind these associations is necessary to inform targeted intervention strategies.

CHAMP1 complex directs heterochromatin assembly and promotes homology-directed DNA repair

BMP signaling promotes zebrafish heart regeneration via alleviation of replication stress

Abstract In contrast to mammals, adult zebrafish achieve complete heart regeneration via proliferation of cardiomyocytes. Surprisingly, we found that regenerating cardiomyocytes experience DNA replication stress, which represents one reason for declining tissue regeneration during aging in mammals. Pharmacological inhibition of ATM and ATR kinases revealed that DNA damage response signaling is essential for zebrafish heart regeneration. Manipulation of Bone Morphogenetic Protein (BMP)-Smad signaling using transgenics and mutants showed that BMP signaling alleviates cardiomyocyte replication stress. BMP signaling also rescues neonatal mouse cardiomyocytes, human fibroblasts and human hematopoietic stem and progenitor cells (HSPCs) from replication stress. DNA fiber spreading assays indicate that BMP signaling facilitates re-start of replication forks after replication stress-induced stalling. Our results identify the ability to overcome replication stress as key factor for the elevated zebrafish heart regeneration capacity and reveal a conserved role for BMP signaling in promotion of stress-free DNA replication.

Determining human resource management key indicators and their impact on organizational performance using deep reinforcement learning

Effectiveness of a hepatitis E vaccine against medically-attended symptomatic infection in HBsAg-positive adults from a test-negative design study

Impact of Covid-19 pandemic on trajectories of patients with severe alcohol use disorder treated with disulfiram

Abstract The manifestations and progression of alcohol use disorder (AUD) are influenced by a number of contextual factors, with the current coronavirus pandemic being a significant example. This pandemic has profoundly impacted nearly all aspects of human life and has, therefore, strongly influenced patients suffering from AUD. In some cases, the pandemic has led to a reduction in severity, while in others, it has had the opposite effect. In our own work we have been investigating the negative impact of the pandemic on 45 patients with AUD who were undergoing outpatient treatment, including supervised use of disulfiram (Antabuse), in a close-knit program. A linear trend analysis demonstrated significant alterations in the retention rate over a 3-year period, encompassing the pre-pandemic, pandemic, and post-pandemic periods. During the pandemic the number of treatment cancellations virtually increased. Following the pandemic, a tendency towards the normalization of patient numbers was observed. Our data indicate a high level of vulnerability among patients with severe AUD and highlight a need for the development of alternative, possibly telemedical, treatment methods.