Browse Articles

Modeling and experimental study of low flow rate miniaturized electrodialysis for artificial kidney applications

In this study, the application of electrodialysis for ion recovery as an active transport mechanism is evaluated where a low flow rate of de-ionized water containing 100 mM NaCl concentration, close to that of total blood plasma concentration, enters an electrodialysis (ED) cell including two inert graphite electrodes to apply an electric field across an anion exchange membrane (AEM) and a cation exchange membrane (CEM) to separate the ions. A mathematical model of the cell is provided using extended Nernst–Planck equation, the resistance of the cell components are measured by a Luggin-capillary device, electrochemical impedance spectroscopy is used to study the ED cell behavior, and chronoamperometry is used to measure the clearance performance for various combinations of membranes. The results indicate that the electrodialysis cell with a single stack of AEM–CEM, effective area of 4 × 4 cm2, intermembrane spacing of 1 mm at a voltage of 4 V, and a volumetric flow rate of 30 ml/h can recover 40% of the ions with high current efficiency over 97%. A modular design using alternating AEM and CEM membranes in series and parallel will be able to process the desired volume of solution and achieve the required ion recovery rate. This study provides insights into the use of electrodialysis in the artificial kidney applications, where a miniaturized electrodialysis cell can reduce the device size significantly and allow for the emergence of long-awaited wearable devices to replace dialysis.

Parametrically amplified Josephson plasma waves in YBa ₂ Cu ₃ O _{6+ <i>x</i>} : Evidence for local superconducting fluctuations up to the pseudogap temperature <i>T</i> ^∗

Experiments that subject underdoped YBa 2 Cu 3 O 6+ x (YBCO) to intense terahertz pulses at temperatures between the transition temperature T c and the pseudogap scale T ∗ have revealed a reflectivity edge that resembles that of the superconducting state, together with second harmonic generation of a probe pulse modulated at a similar frequency. These have been interpreted in terms of parametric amplification of the lower Josephson plasmon mode. Since this mode is often associated with coherent oscillations between bilayers in the YBCO structure, these experiments have led to the suggestion that the intense pump has created (or revealed) in-plane pair coherence up to T ∗ ≈ 400 K. In this paper we propose an alternative explanation by assuming the existence of local pair amplitude and phase at equilibrium for T c &lt; T &lt; T ∗ . The phase correlation spans only a few lattice constants and we do not assume any pump-induced enhancement of this correlation, either in-plane or between bilayers. Instead, the coherent drive, via a parametric amplification process, induces coherence in the Josephson currents between members of bilayers. When combined with a Floquet framework, the reflectivity data can be explained. The key point is that in the lower Josephson plasmon, the coupling between bilayers is mainly capacitive; the Josephson current between bilayers can be set to zero without strongly affecting the parametric amplification process. Importantly, while superconducting coherence may not be created by the pump, the pseudogap phase must possess a local pairing amplitude at equilibrium. Consequently, these experiments have strong implications for the understanding of the pseudogap phase.

Editorial Note: Where octagonal geometry meets chaos: A new S-Box for advanced cryptographic systems

Airborne particle emissions from photocatalytic coatings and paints

First-principles dopant screening to suppress shallow traps in HfO2 charge-trap layers for 3D <scp>nand</scp> flash memory

As three-dimensional (3D) nand flash memory continues to scale toward higher integration, lateral and vertical thinning of the Si3N4 charge-trap layer (CTL) leads to memory window narrowing and accelerates lateral charge loss. Hafnium oxide (HfO2) has emerged as a promising alternative CTL material due to its high-dielectric-constant (high-k) permittivity, which enables effective-oxide-thickness scaling without excessive physical thinning. However, shallow traps caused by oxygen vacancies (VO) still induce critical lateral charge loss in HfO2-based CTLs. In this work, density functional theory calculations are employed to identify suitable dopants capable of mitigating these shallow traps in HfO2. Various dopant species are systematically evaluated at hafnium and oxygen substitutional sites as well as interstitial sites to assess how possible dopant site occupations influence trap level formation. Furthermore, the local coordination environments are analyzed to obtain structural insight into the observed trends in trap levels. In addition, VO-induced defect structures are characterized to establish correlations between vacancy configurations and trap state characteristics. The results indicate that, among the dopants considered, Al and Bi show robust trap level characteristics for suppressing VO-related shallow traps in HfO2, suggesting a route to mitigate lateral charge loss. Technology computer-aided design simulations further support the resulting reduction in lateral charge loss at the device level. These findings demonstrate dopant-based trap engineering as a viable strategy for mitigating lateral charge loss in HfO2, enabling scalable CTLs for next-generation 3D nand flash memory.

Alpha rhythms in the left auditory cortex set the speed limit for speech comprehension

Human cognition operates within distinct temporal windows spanning from very short to extremely long. Each cognitive function has its own processing speed range, beyond which performance deteriorates or even becomes impossible. Speech comprehension, as one of the most important cognitive functions in civilized societies, exemplifies this constraint: Performance declines markedly when speech rates exceed about 10 syllables per second. However, the neural mechanisms underlying this speed limit remain unclear. Here, by combining psychophysics, scalp-electroencephalography, transcranial alternating current stimulation (tACS), repetitive sensory stimulation, and stereo-electroencephalography (sEEG), we showed that the intrinsic alpha band activity determined the maximum rate of speech comprehension. In healthy participants, individual alpha frequency (IAF) precisely predicted the speech recognition rate threshold. Crucially, causally accelerating endogenous alpha rhythms via high-definition tACS and rhythmic auditory stimulation shifted this threshold, enhancing comprehension of ultrafast speech. Furthermore, sEEG recordings from the human auditory cortex revealed that this speed-limiting mechanism was locally determined: Faster alpha band activity in the left auditory cortex facilitated stronger neural entrainment to the speech envelope. These findings identify alpha band activity as a fundamental, malleable temporal bottleneck for linguistic processing, suggesting that the brain’s intrinsic sampling rate sets the physiological limit on human communication.

Establishment and characterization of three canine ameloblastoma cell lines with genomic and transcriptomic profiles

Establishment of canine acanthomatous ameloblastoma (CAA) cell lines has profound importance in pre-clinical in vitro testing. The goal of this study was to develop, authenticate, and characterize three CAA cell lines. Cell lines were developed with standard cell culture techniques from dogs with naturally occurring CAA. Each cell line was authenticated as canine with a validated PCR panel. Epithelial cell origin was confirmed with pan-CK flow cytometry. Next generation DNA and RNA sequencing characterized features of the cell lines and compared them to the parent tumor. We confirmed that all cell lines maintained mutations seen in the parent tumors including a missense HRAS mutation and RTK-RAS pathway upregulation across all samples. Other common mutations (2/3 cell lines and their parent tumors) included ADGRA3, DNAH7, F10, KIAA1671, OGFR, SLC6A17, SNX7, SPTBN5, TENM4 , and YEATS2 . We compared the transcriptional profiles from our parent tumors and established cell lines to historical transcriptomic analysis of CAA and healthy gingiva. We confirmed the same canonical CAA molecular features of primary tumors across studies with distinct clustering from healthy gingiva. Further, we documented that the cell lines maintained upregulated genes that are seen within in vivo CAA across both studies including upregulated GPC4 and ETV5 as well as gene sets associated with the presence of epithelial-mesenchymal transformation, KRAS, Pi3K-AKT signaling, and hedgehog signaling pathways. Thorough characterization of the mutational and transcriptional profiles of the established cell lines, especially in context to how they differ from the parent tumors, sets the platform for translational in vitro testing.

One Health dynamics: toxoplasmosis in free-roaming (semi-domiciled and stray) dogs and reported human cases over time

Orientation-dependent atomic diffusion and interfacial evolution in Au–Si eutectic bonding: A molecular dynamics study

This work systematically investigates the interfacial structure evolution, atomic diffusion behavior, strain distribution, and defect formation mechanisms of Au–Si bonding systems with different crystallographic orientation combinations. The results demonstrate that the interfacial properties, atomic mobility, and eutectic bonding performance of the bonding systems strongly depend on the crystal orientation of the Au–Si interfaces. Among the Au–Si (100) bonding systems, the Si (100)–Au (110) interface exhibits the strongest interfacial diffusion capability and atomic mixing behavior due to the relatively open atomic arrangement of the Au (110) surface, which effectively reduces the eutectic nucleation barrier and expands the effective eutectic reaction region. In the Au–Si (110) bonding systems, although the Si (110)–Au (100) and Si (110)–Au (110) interfaces exhibit relatively high mean squared displacement values, the actual number of diffused atoms and the diffusion depth along the z-direction remain limited because of the high vertical diffusion barrier of the Si (110) crystal plane. In addition, obvious stacking faults, localized hexagonal close packed phase transformation, and dislocation structures are observed in these systems, indicating that the interfacial strain could be released through defect-mediated structural evolution. Overall, the simulation results confirm that the Si (100)–Au (110) interface is the most favorable structure for Au–Si eutectic bonding.

Evidence of intertwined pair density and charge density wave orders in UTe ₂

The strongly correlated spin-triplet superconductor UTe 2 hosts an unusual magnetic-field-sensitive charge density wave (CDW) phase, positioning it as a compelling system for studying intertwined electronic orders. A central challenge is determining whether the observed charge modulations arise from a triplet pair density wave (PDW) order and, if so, how the anisotropic magnetic field response of triplet superconductivity is manifested in the CDW response. Here, using a scanning tunneling microscope equipped with a vector magnetic field, we systematically investigate the evolution and interrelation of distinct CDW orders. Complementing the previously identified incommensurate CDW peaks ( q i =1,2,3 ), we resolve an additional set of nondispersive modulations ( p i =1,2,3 and h 1,2 ) with distinct temperature and magnetic field dependencies. The p i CDW peaks vanish near T c , while the q i peaks survive well above T c but are progressively suppressed by magnetic field in an anisotropic manner. The critical fields of the q i peaks mirror the directional hierarchy of H c2 , which suggests a PDW is present above the bulk T c . This is consistent with a Landau free-energy picture where PDWs with wavevectors p i form above the bulk T c , leading to composite CDW orders with wavevector q i . Below T c , the coupling of PDWs and uniform superconductivity leads to the p i CDWs. Together, these findings establish UTe 2 as a rare platform where both the parent PDW and descendant orders are directly resolved, enabling access to both the fundamental and emergent manifestations of PDW physics.

Modelled climatic suitability contraction and high-altitude persistence: Projected mid-century distribution dynamics of Ophiocordyceps sinensis across the Tibetan Plateau under a selected climate scenario

Ophiocordyceps sinensis , a vulnerable fungal resource endemic to the Tibetan Plateau, faces climatically driven habitat degradation under ongoing climate change. Existing studies document its distribution but rarely address temporal dynamics under ongoing climate shifts. To fill this research gap, we implemented five-fold spatial block cross-validation (SBCV)-enhanced MaxEnt modelling and quantified extrapolation risks via Multivariate Environmental Similarity Surfaces (MESS; mean = 0.734 ± 0.135) using 201 spatially filtered occurrence points. Model performance was primarily evaluated via geographically independent spatial validation, yielding a mean test area under the receiver operating characteristic curve of 0.953 ± 0.002, confirming robust spatial transferability across the Tibetan Plateau. Integration of static topographic and dynamic bioclimatic variables across past–current–future timelines enabled validation against historical baselines (1970–2000), followed by Shared Socioeconomic Pathways 3–7.0 (SSP3–7.0) scenario projections. Elevation and warmest-quarter precipitation emerged as dominant predictors, collectively explaining 91.3% of habitat suitability. Under the BCC-CSM2-MR model and SSP3–7.0 scenario, conditional projections indicate severe near-term climatic suitability contraction (54% loss in modelled suitable habitat area relative to the 1970–2000 historical baseline, from 396,000 km 2 to 182,000 km 2 by 2021–2040), with over 82% of this total loss concentrated in marginal zones. Driven by localized expansion in the Tanggula Mountains that offsets low-elevation declines, the total modelled suitable habitat area stabilized at 198,000 km 2 , accounting for 3.78% of China’s land area, during the mid-century (2041–2060) under this model-scenario combination. This validated framework provides conditional insights for identifying potential climate refugia of O. sinensis and supporting evidence-based climatic suitability assessments.

Optimization and OGY-based chaos control of a bistable piezoelectric energy harvester for enhanced power generation

Atomic mechanism for elastic–plastic behaviors of uranium-6 wt. % niobium single crystal alloy under shock compressions

The absence of an elastic precursor (EP) in shock-loaded U-6 wt. % Nb alloys has long been attributed to the rapid shear stress relaxation due to phase transformation or twinning. As a first step toward uncovering such issues, we investigate the shock responses of uranium-6 wt. % niobium single-crystal alloys through large-scale non-equilibrium molecular dynamics simulations combined with first-principles calculations. Our results suggest that no clear EP is observed for shocks along the b and c axes, while an EP emerges along the a axis under certain conditions. The EP disappearance stems from a slower elastic-wave velocity compared to the plastic wave velocity—a direct consequence of enhanced compression modulus during shock compression. The modulus enhancement in the α″ phase is attributed to the first stage of a two-stage plastic mechanism: picosecond-scale stress decay via coordinated (001)-plane shuffling forms a transient intermediate phase, followed by a much longer timescale γ-phase transformation through [100]/[1¯00] shear on (010) planes, generating {112}〈111〉 twins. This mechanism underscores the critical role of transient intermediate phases under rapid compression, challenging prior interpretations and providing atomic-scale insights for the shock responses of uranium alloys.

Plants are a powerful proxy for global tidal marsh methane fluxes

Methane (CH 4 ) emissions can reduce the climate benefits of tidal marshes. Yet the drivers of tidal marsh CH 4 emissions remain poorly quantified, and salinity, the most well-established proxy for tidal marsh CH 4 fluxes, has low predictive performance. Here, we demonstrate that plant species out performs salinity as a single predictor of global tidal marsh CH 4 fluxes, providing a powerful and simple predictor on its own. A multiproxy approach combining plant species with other predictors (i.e., latitude, salinity, season) further improves predictions of global CH 4 fluxes. For our analysis, we compiled 87 studies with 2,094 mean measurements of CH 4 fluxes and used random forest and generalized additive modeling to investigate the relationship among CH 4 fluxes, salinity, and plants. We found that plant species was the most important predictor of CH 4 fluxes globally. Our model of plant species alone explained 62% of the variability in CH 4 fluxes and when including latitude, season, and soil salinity, explained 71%. We also developed a model with plant functional type for when plant species flux data are not available. We found that plant functional type alone explained 54% of the variability in CH 4 fluxes, underscoring the influential role of plants. Previously, polyhaline marshes were thought to have low CH 4 emissions. Here we show that CH 4 fluxes from these marshes offset between 1% and 39% of carbon sequestration, depending on the plant species present and selected global warming potential value. This plant species-based approach significantly improves global CH 4 flux estimates in tidal marshes and facilitates global carbon accounting.

Correction: A scoping review and thematic analysis of the landscape of spiritual health and spirituality in Canada

Machine learning-driven estimation of microplastic percentage yield for rapid and accurate quantification

Mechanical metamaterials

Mechanical metamaterials derive their extraordinary effective properties primarily from architecture rather than from constituent chemistry. This Special Topic in Journal of Applied Physics assembles eleven contributions that span the contemporary breadth of the field, ranging from terahertz phononic bandgaps in van der Waals heterostructures to ventilated low-frequency acoustic absorbers, transient flexural-wave control, bistable lattices with negative stiffness under multi-modal loading, hierarchically porous lattices manufactured by foaming fused deposition modeling, culturally inspired unit cells, oxide ceramics with negative permittivity, and tunable microgel suspensions. Together, the works document a field in which geometric programming is increasingly coupled with multi-physics integration, accessible manufacturing, and application-driven engineering.

Compensation and colonization offset the impacts of biodiversity loss over time in grasslands

The biodiversity–productivity relationship (BPR) is crucial for understanding the consequences of biodiversity loss; yet, how this relationship evolves over time in natural ecosystems remains unclear. Several long-term biodiversity experiments with artificially assembled communities suggest that the BPR escalates over time, however, whether this pattern applies to natural ecosystems has not been explored. Here, we present the results of a 15-y removal experiment in the Inner Mongolia grassland, where gradients of plant functional group (PFG) richness and species richness were created through targeted removals from 2006–2009, followed by natural recolonization from 2010 onward. We found that both the PFG richness-based and species richness-based BPRs diminished gradually during the removal period (years 2–4) and decoupled in 9 out of 12 y after the cessation of removal (years 5–16), suggesting that the negative impacts of biodiversity loss do not necessarily escalate over time; rather, they may decrease. We identified that the temporal shift in BPRs resulted first from compensatory growth of remaining species and subsequently from new colonization by external populations. These results highlight that the impacts of biodiversity loss in natural ecosystems are strongly modified by assembly processes such as compensation and colonization. Therefore, models predicting the ecosystem consequences of biodiversity loss should consider these mechanisms. Ignoring them may lead to an overestimation of the long-term impacts of biodiversity loss in natural communities, particularly where surrounding landscapes harbor species pools capable of recolonization.

The impact of mixed-anonymity on brainstorming performance: Evidence from field experiments

Generating innovative and valuable ideas is essential for organizational competitiveness, and structured ideation formats are widely used to support creativity and idea generation of individuals, teams, and organizations. One such format is nominal brainstorming, in which participants generate ideas independently rather than through group interactions. Previous research has produced mixed results regarding the impact of anonymity in such individual idea-generation settings. Anonymous formats may reduce evaluation apprehension but can also lead to free riding, while non-anonymous formats promote accountability yet might increase the fear of negative evaluation. To clarify these conflicting findings, this study examines a novel mixed-anonymity approach in which participants generate ideas independently and anonymously, but the identities of those with the highest-rated ideas are subsequently revealed. We investigate the effects of mixed-anonymity on individually generated brainstorming outputs in two field experiments. The first adopts a between-subject design (N = 216), randomly assigning participants to anonymous, non-anonymous, or mixed-anonymity conditions. The second follows a within-subject design (N = 192), exposing each participant to all three conditions. In both studies, participants engaged in nominal brainstorming tasks. Ideation outcomes were measured by quantity, novelty, and user value. Additionally, we assessed evaluation apprehension and free riding as potential mediators. Our between-subject experiment did not demonstrate significant differences in idea quantity, novelty, or user value among the three anonymity conditions. Conversely, the within-subject experiment revealed significantly higher idea novelty under mixed-anonymity conditions compared to anonymous and non-anonymous conditions, but no significant effects on idea quantity or user value. Contrary to initial hypotheses, the proposed mediators, evaluation apprehension and free riding, did not explain these results. These findings refine the current understanding of anonymity in nominal brainstorming by showing that mixed-anonymity does not yield consistent effects across experimental settings. Overall, this study indicates that the role of mixed-anonymity in individual idea generation is contingent, not as straightforward as existing theorizing based on evaluation apprehension and free riding would suggest.

Research on classification diagnosis of DC magnetic bias degree of power transformers based on probabilistic neural network by mirage search optimization