Dominant Mechanism Research Articles

Mice lacking acid-sensing ion channel 2 in the medial prefrontal cortex exhibit social dominance.

Social dominance is essential for maintaining a stable society and has both positive and negative impacts on social animals, including humans. However, the regulatory mechanisms governing social dominance, as well as the crucial regulators and biomarkers involved, remain poorly understood. We discover that mice lacking acid-sensing ion channel 2 (ASIC2) exhibit persistently higher social dominance than their wild-type cagemates. Conversely, overexpression of ASIC2 in the medial prefrontal cortex reverses the dominance hierarchy observed in ASIC2 knockout (Asic2-/-) mice. Asic2-/- neurons exhibit increased synaptic transmission and plasticity, potentially mediated by protein kinase A signaling pathway. Furthermore, ASIC2 plays distinct functional roles in excitatory and inhibitory neurons, thereby modulating the balance of neuronal activities underlying social dominance behaviors-a phenomenon suggestive of a cell subtype-specific mechanism. This research lays the groundwork for understanding the mechanisms of social dominance, offering potential insights for managing social disorders, such as depression and anxiety.

Language and power: linguistic imperialism

Linguistic imperialism refers to the dominance of one language over others, often resulting in the marginalization of local languages and cultures. This phenomenon has significant implications for power dynamics in global communication, education, and identity formation. The paper explores the historical context of linguistic imperialism, examining how colonialism and globalization have contributed to the prevalence of languages such as English in international discourse. The object of research is the impact of linguistic hegemony on non-dominant languages and their speakers. The subject of this study focuses on the social, political, and cultural ramifications of linguistic imperialism, particularly in post-colonial societies. Through a comprehensive literature analysis, the article identifies key theories and frameworks that explain the mechanisms of language dominance. The research employs qualitative methods, including discourse analysis and case studies, to illustrate the lived experiences of individuals affected by linguistic oppression. The findings reveal a correlation between language use and power relations, underscoring the need for inclusive language policies that promote linguistic diversity. The prospects for further research development include investigating strategies for revitalizing endangered languages and fostering multilingualism in educational contexts. In conclusion, addressing linguistic imperialism is crucial in promoting social justice and preserving cultural heritage in an increasingly interconnected world.

Toxic work climates: An integrative review and development of a new construct and theoretical framework.

Research and the media demonstrate the profound impact hostile work environments have on organizations and their members. Often, the term "toxic work climate" is used to describe patterns of aggressive behaviors that harm individuals and manifest in the broader workplace. However, despite these common references, scholars still know relatively little about what a toxic work climate actually entails, the processes by which they emerge, and their influence on organizational outcomes. The research domain is complex. Within the organizational literature alone, toxic work climates have been described as those that harbor abusive bosses, aggressive employees, and those that show signs of bullying or incivility. Our aim in this integrative conceptual review is to add precision and focus to this multidisciplinary and fragmented literature. Grounding our efforts in multilevel theories, we first introduce an overarching definition of the toxic work climate construct and review research on existing hostile climate types that can appropriately be consolidated under this new heading. We then develop a new theoretical model that outlines the dominant causes and mechanisms by which toxic work climates form, and the main pathways by which they influence employees, teams, and organizations. Finally, we provide a unified path forward for advancing theory, research, and practice, including advice on how toxic climates might be combated in years to come. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Enhanced creep resistance and microstructure in 7055 Al alloy by in-situ (Al2O3 + ZrB2) nanoparticles and Al3(Er, Zr)

This work put forward a novel approach to enhancing high-temperature creep resistance of 7055 Al alloy via inducing reinforcements including in-situ (Al2O3 + ZrB2) nanoparticles and Al3(Er, Zr). Creep steady-state rates of the (Al2O3 + ZrB2)/7055 Al composites enhanced by synergistic Er, Zr were lower than the (Al2O3 + ZrB2)/7055 Al composites, indicating the values of stress component (n) and apparent activation energy (Q) were 1.05–1.15 and 1.06–1.08 times of (Al2O3 + ZrB2)/7055 Al composites. The dislocation climb mechanism was considered as the dominative creep mechanism because the suitable true stress exponent was 5. The uniform distribution of Al2O3 and Al3(Er, Zr) and their influence on improving the distribution of ZrB2 aggregates gave rise to relative uniform deformation during creep process. The built interface models that induce Al3(Er, Zr) between the nanoparticle/Al interface could lead to a more thermodynamically stable and well-bonded interface. The coupling effect of attachments containing Al2O3, ZrB2 and Al3(Er, Zr) played an enhanced role in terms of vacancy-trapping, precipitate-nucleation, dislocation motion during creep process. The nanoparticles and Al3(Er, Zr) together with nuclear sites containing solute atoms, vacancies and misfits nearby, caused an expansion-inhibiting effect on the helical dislocations. The in-grain misorientation axes (IGMA) concentration of some deformed grains associated with Schmid factor (SF) analysis were related to 〈001〉, 〈111〉 and 〈101〉 direction. The calculation of creep resistance mechanisms was quantified. Additionally, typical intergranular fracture appeared within the composites due to the relatively uniform reinforcements, resulting in the complex crack path.

Self‐help or self‐sabotage? A common invader's soil legacy does not impede, and may facilitate, potential competitors

AbstractIntroduced plants create lasting abiotic and biotic changes to soil that are increasingly implicated as major drivers of invasion success, yet models for investigating patterns in the impacts of these soil legacies are lacking. Here, we used Bohemian knotweed (Reynoutria × bohemica) to present a novel approach for testing whether accounting for diverse evolutionary drivers can clarify how an invader's soil legacy mediates its success. For most tested species, R. × bohemica's soil legacy did not influence seedling performance irrespective of its evolutionary history or the evolutionary novelty of species that share its soil. However, we found the relative importance of legacy effects versus other mechanisms of invader dominance depends on the life stage of the plants growing in soil conditioned by the invader. While the effects of R. × bohemica's soil legacy on seedling performance were context dependent, emergence was, on average, higher in R. × bohemica‐conditioned soils than in unconditioned soils. Thus, contrary to theory, R. × bohemica's soil legacy not only fails to impede potential competitors but may also facilitate them. Our results are particularly powerful: we detected novel insights in the face of biological complexity, even for R. × bohemica, which likely does not depend on heterospecific plant–soil feedbacks for its competitive dominance in its introduced range. Designing rigorous investigations that explore how plant species' evolutionary histories mediate an invader's soil legacy across diverse abiotic environments, as shown here, is key for producing insights in other systems.

Superplastic deformation behavior of low Al–added medium Mn steels with and without Ti and Mo elements

Fe-Mn-Al-C medium Mn steels were found to reveal extraordinary superplasticity and have significant potential for forming the complex structural parts due to high strength, excellent ductility and material cost. In present study, the effect of tensile deformation temperature on the superplastic deformation behavior of a cold-rolled low Al-added medium Mn steel was studied. A maximum tensile elongation of approximately 1170% was obtained at 745 °C and 10−2 s−1, which is to our best knowledge the highest low-temperature-high-strain-rate superplasticity in medium Mn steels. Also, the role mechanism of microalloying elements such as Ti and Mo was revealed to further enhance the strength level of superplastic medium Mn steels. In view of the representative microstructural features, such as equiaxed grains, random texture, and sluggish grain growth, grain boundary sliding is thought to be the dominative mechanism during the high-strain-rate superplastic deformation.

Abstract SY07-01: p53-mediated stem cell competition: Insights into mechanisms of clonal dominance

Abstract TP53 Mutations confer clonal advantage in several tissues contributing to tumorigenesis. It has traditionally been proposed that heightened resistance to apoptosis/cell cycle arrest can account for clonal advantage. P53 mediated clonal dominance has also been observed in cultured embryonic stem (ES) cells, though it is not clear how this is established. Using live cell imaging we show that human ES cells (hESCs) mutant for TP53 induce death of hES-WT cells and outcompete them. Competition is mediated by apoptosis induction and requires direct cell contact, as in co-cultures of hES-P53KO and hES-WT cells where contact is prevented competition is not observed. To ask if hES-P53KO competition is mediated by mechanical interactions, we cultured cells on deformable membranes to measure their resistance to cell compaction. Interestingly, while hES-WT cells displayed apoptosis induction upon cell compaction, hES-P53KO cells were resistant to compaction-induced apoptosis. We suggest that differential sensitivity to compaction in crowded cultures/tissues can drive p53-induced competitive cell elimination. Identifying the mechanisms by which p53 confers resistance to cell compaction could lead to novel actionable targets to prevent the expansion of p53 mutant stem cells in cancerous and pre-cancerous lesions. Citation Format: Eugenia Piddini. p53-mediated stem cell competition: Insights into mechanisms of clonal dominance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr SY07-01.

Interannual Lightning Variability within the TRMM LIS Dataset Using an ENSO Perspective

Abstract The Tropical Rainfall Measuring Mission (TRMM) Lightning Imaging Sensor (LIS) was used to investigate interannual variability of lightning from 1998 to 2014 within the 38°S–38°N range. Previous studies have indicated that the El Niño–Southern Oscillation (ENSO) phenomenon is one significant contributor to interannual lightning variability, potentially the dominant mechanism on the global scale. This period of 16 years contained four warm- (El Niño), eight cold- (La Niña), and four neutral-phase ENSO years based on the oceanic Niño index. Large magnitude lightning anomalies were found during the warm phase of ENSO, with mean warm-phase anomalies of >10 flashes (1000 km)−2 min−1 in north-central Africa and Argentina. This includes a +35 flashes (1000 km)−2 min−1 anomaly in Argentina during the 2009 El Niño. In general, large-scale anomalies of thermodynamic properties and upper-atmospheric vertical motion coincided with the lightning anomalies observed in both Africa and South America. The anomaly over north-central Africa, however, was characterized by a 6-week shift in the annual lightning maximum with the warm phase, a result of the more complex environmental response to ENSO over the Sahel. The most consistent ENSO anomalies with appreciable lightning were found in southeastern Africa, northwestern Brazil, central Mexico, and the southern Red Sea. Of these, all but the Mexico region had enhanced lightning with the cold phase and suppressed lightning with the warm phase.

AGNs in massive galaxy clusters: Role of galaxy merging, infalling groups, cluster mass, and dynamical state

Context. There is compelling evidence that active galactic nuclei (AGNs) in high-density regions have undergone a different evolution than their counterparts in the field, indicating that they are strongly affected by their environment. However, we still lack a comprehensive understanding of the dominant mechanisms that trigger the nucleus and the processes that drive the evolution of AGNs in clusters. Aims. To investigate (and possibly disentangle) the various factors that may affect the prevalence of AGNs in cluster galaxies, we selected a sample of 19 thoroughly studied X-ray-selected galaxy clusters from the LoCuSS survey. All these clusters are considered massive, with M500 ≳ 2 × 1014 M⊙, and span a narrow redshift range between z ∼ 0.16 and 0.28. Methods. We divided the cluster surroundings into two concentric annuli with a width of R500 radius. We considered the first annulus as the central cluster region and the second as the outskirts. We further divided the cluster sample based on the presence of infalling X-ray-detected groups, cluster mass, or dynamical state. We determined the AGN fraction in cluster galaxies of the various sub-samples by correlating the X-ray point-like sources selected from the 4XMM DR10 catalogue with the highly complete spectroscopic catalogue of cluster members obtained with Hectospec. We subsequently used the optical spectra to determine the type of nuclear activity and we visually inspected the host morphology for indications of galaxy mergers or other interactions. Results. We found that the X-ray AGN fraction in the outskirts is consistent with the field, but it is significantly lower in cluster centres, in agreement with previous results for massive clusters. We show that these results do not depend on cluster mass, at least within our cluster mass range, nor on the presence of X-ray-detected infalling groups. Furthermore, we did not find any evidence of a spatial correlation between infalling groups and AGNs. Nevertheless, a significant excess of X-ray AGNs is found in the outskirts of relaxed clusters at the 2σ confidence level, compared both to non-relaxed clusters and to the field. Finally, according to the literature, the fraction of broad- to narrow-line AGNs in clusters is roughly consistent with the field. However, broad-line AGNs may be preferably located in cluster centres. In the outskirts, the optical spectra of X-ray AGNs present narrow emission lines or they are dominated by stellar emission. Conclusions. Our results suggest that the mechanisms that trigger AGN activity may vary between cluster centres and the outskirts. Ram pressure can efficiently remove the gas from infalling galaxies, thereby triggering AGN activity in some cases. However, the reduced availability of gas globally diminishes the fraction of AGNs in cluster centers. The surplus of X-ray AGNs identified in the outskirts of relaxed clusters may be attributed to an increased frequency of galaxy mergers, a notion that is further supported by the disturbed morphology observed in several galaxies.

Moiré Pattern Controlled Phonon Polarizer Based on Twisted Graphene.

Twisted van der Waals materials featuring Moiré patterns present new design possibilities and demonstrate unconventional behaviors in electrical, optical, spintronic, and superconducting properties. However, experimental exploration of thermal transport across Moiré patterns has not been as extensive, despite its critical role in nanoelectronics, thermal management, and energy technologies. Here, thefirst experimental study is conducted on thermal transport across twisted graphene, demonstrating a phonon polarizer concept from the rotational misalignment between stacked layers. The direct thermal and acoustic measurements,structural characterizations, and atomistic modeling, reveal a modulation up to 631% in thermal conductance with various Moiré angles, while maintaining a high acoustic transmission. By comparing experiments with density functional theory and molecular dynamics simulations, mode-dependent phonon transmissions are quantified based on the angle alignment of graphene band structures and attributed to the coupling among flexural phonon modes. The agreement confirms the dominant tuning mechanisms in adjusting phonon transmission from high-frequency thermal modes while having negligible effects on low-frequency acoustic modes near Brillouin zone center. This study offers crucial insights into the fundamental thermal transport in Moiré structures, opening avenues for the invention of quantum thermal devices and new design methodologies based on manipulations of vibrational band structures and phonon spectra.

Sublithospheric diamonds extend Paleoproterozoic record of cold deep subduction into the lower mantle

Cold deep subduction – a hallmark of modern-style plate tectonics – is the dominant mechanism for recycling crustal materials into Earth's deep mantle, potentially changing its composition, heat budget and dynamics. The onset of cold deep subduction remains contentious and is largely constrained by crustal rocks, despite subduction being driven by mantle processes. Here we use the chemical and chronological information from sublithospheric mantle-derived minerals entrapped in diamonds from the DO-27 kimberlite, Slave Craton, Canada, to better constrain the timing and products of cold deep subduction reaching Earth's lower mantle. DO-27 sublithospheric diamonds preserve a complete lower mantle mineral assemblage: Ca-silicates (retrogressed CaSi-perovskite) ± enstatite (retrogressed bridgmanite) ± ferropericlase. The high Mg#s (molar Mg/(Mg+Fe)) of retrogressed bridgmanite (median Mg#=95) and ferropericlase (median Mg#=86) implicate a harzburgitic host rock for the diamonds. This strongly melt-depleted signature contrasts with the high abundance of Ca-silicate inclusions, some of which are variably enriched in incompatible elements and have enriched Sr-Nd-Pb isotopic signatures that collectively indicate the host rock was metasomatized by carbonatitic melts released from a relatively cold subducting slab in the lower mantle. The U-Pb systematics of the Ca-silicates define two ages of diamond crystallisation: 998 ± 18 Ma and 1679 ± 13 Ma. This is the first direct evidence of cold deep subduction in Earth's lower mantle at ∼1.7 Ga (Paleoproterozoic), in agreement with the oldest crustal low-temperature, high-pressure eclogites and is much earlier than previous Neoproterozoic estimates.

Emission of Parasitic X Rays of Vacuum-electron Tubes with Glass Housings: Implications for the Evaluation of Occupational Doses.

Despite the large variety of high-voltage semiconductor components for medium and high voltage switching and pulse-forming applications as well as for high-power high-frequency generation, the use of vacuum electron tubes still prevails to a considerable degree. Due to the common design incorporating a high energy electron beam which finally is dumped into an anode or a resonator cavity, these tubes are also considered as sources of X rays produced as bremsstrahlung and characteristic radiation, which are referred to as parasitic X rays. Here three types of vacuum-electron tubes, diode, tetrode, and thyratron, with glass housings are investigated. They are predominantly operated in the high voltage range below 30 kV and are not subject to licensing laws. The measurements of the dose rate and X-ray-spectra were performed in the laboratory without complex electrical circuitry usually used in making practical measurements for occupational radiation protection. For the diode tube, where a parasitic X-ray emission is observed only in the reverse operation as a blocking diode, a broad distribution of dose rates of electrically equivalent specimens was observed. This is attributed to field emission from the electrodes. For the tetrode and the thyratron tubes, field emission from the electrodes is identified as the dominant mechanism for the generation of parasitic X rays. Thus, technical radiation protection must focus on shielding of the glass tube rather than optimization of the electrical circuitry.

Stability analysis of WEST L-mode discharges with improved confinement from boron powder injection

WEST L-mode plasmas with dominant electron heating and no core torque source have observed improvements in confinement during boron (B) powder injection. These results are reminiscent of previous powder injection experiments on other devices and gaseous impurity seeding experiments on WEST. During powder injection, the stored energy increased up to 25% due to enhanced ion and electron heat and particle confinement. The improvements in confinement were not indicative of an L-H transition. To identify the dominant mechanisms and the causality chain behind these improvements in confinement, we employ interpretative modeling using METIS, predictive integrated modeling using a high-fidelity plasma simulator (HFPS), and stand-alone gyrokinetic simulations using quasi-linear gyrokinetic code. Interpretative modeling with METIS allowed for the estimation of missing data while maintaining good overall consistency with experiment. These results provided the initial conditions for fully predictive flux driven simulations using the HFPS. From these simulations, quasi-linear gyrokinetic analysis was performed at ρ=0.5 and ρ=0.65 . Collisionality was found to be a strong candidate for the turbulence suppression mechanism at ρ=0.5 , while a combination of collisionality and the Te/Ti ratio was found to be the likely mechanism at ρ=0.65 . The results additionally suggested that increased Zeff (through main ion dilution) could play a role in the improved confinement, but this could not be confirmed due to a lack of experimental measurements. The modeling framework established here can now be used to evaluate and exploit a variety of future powder injection experiments.

Neoproterozoic Lysan Alkaline–Ultramafic Complex in the Eastern Sayan, Southern Siberia, Russia: Mineralogical Constraints of Carbonate Rocks and Albitite for Petrogenesis

The Lysan alkaline–ultramafic complex is located in the Sisim shear zone at the contact of the two largest tectonic structures of the accretion–collisional belt in the southwestern frame of the Siberian craton. Intrusions of the complex consist of ore-bearing olivinites, kaersutite clinopyroxenites, and banded kaersutite gabbro, which have been «cut» by albitite dykes and veins. The veins and veinlets of the carbonate rocks are mainly associated with the albitites. The present paper represents the first detailed mineralogical study of carbonate rocks and albitites in the Podlysansky Massif of the Neoproterozoic Lysan alkaline–ultramafic complex. The mineral composition was determined in situ in a polished section by scanning electron microscopy, energy dispersive spectrometry, and electron probe microanalysis. The carbonate rocks of the Podlysan Massif have been found to contain minerals that are typical of siderite–carbonatites (senso stricto), including calcite, siderite, phengitic muscovite, apatite, monazite, REE fluorocarbonates, pyrite, and sphalerite. These rocks are enriched in light rare earth elements due to the presence of monazite-(Ce), bastnäsite-(Ce), parisite-(Ce), and synchysite-(Ce). The albitites were formed as a result of the fenitization of leucocratic gabbro by alkali-rich carbo-hydrothermal fluids in zones of intense development of tectonic fractures. Infiltration was the dominant mechanism of fenitization. The obtained data significantly enhance the current understanding of the geochemical and ore specialization of rocks in the Lysan Complex.

Model construction and dominant mechanism analysis of li-ion batteries under periodic excitation

Model construction and dominant mechanism analysis of li-ion batteries under periodic excitation

Dynamic Reconstruction of Two-Dimensional Defective Bi Nanosheets for Efficient Electrocatalytic Urea Synthesis.

Catalyst surface dynamics drive the generation of active species for electrocatalytic reactions. Yet, the understanding of dominant site formation and reaction mechanisms is limited. In this study, we thoroughly investigate the dynamic reconstruction of two-dimensional defective Bi nanosheets from exfoliated Bi2Se3 nanosheets under electrochemical CO2 and nitrate (NO3 -) reduction conditions. The ultrathin Bi2Se3 nanosheets obtained by NaBH4-assisted cryo-mediated liquid-phase exfoliation are more easily reduced and reconstructed to Bi nanosheets with high-density grain boundaries (GBs; GB-rich Bi). The reconstructed GB-rich Bi catalyst affords a remarkable yield rate of 4.6 mmol h-1 mgcat. -1 and Faradaic efficiency of 32 % for urea production at -0.40 V vs. RHE. Notably, this yield rate is 2 and 8.2 times higher than those of the low-GB Bi and bulk Bi catalysts, respectively. Theoretical analysis demonstrates that the GB sites significantly reduce the *CO and *NH2 intermediate formation energy and C-N coupling energy barrier, enabling selective urea electrosynthesis on the GB-rich Bi catalyst. This work will trigger further research into the structure-activity interplay in dynamic processes using in situ techniques.

Study the Efficiency of the XGBoost Algorithm for Squat RC Wall Shear Strength Prediction and Parametric Analysis

Squat-reinforced concrete (RC) shear walls with an aspect ratio of less than two are considered effective structural members, where shear is the dominant failure mechanism. Squat shear walls are widely used in nuclear power plants and building construction and feature optimal cost and outstanding performance, due to their lateral strength and high rigidity to resist lateral loads. However, since the accurate evaluation of the shear strength of squat shear walls must meet the design specifications, its calculation may be very complex, challenging, and inaccurate using experimental and theoretical equations due to many influential and overlapping design factors, so it takes more time and higher cost to determine it. This study uses machine learning (ML) methods to build a shear strength prediction efficient model for squat RC walls to address these issues. First, a huge dataset of 1424 RC squat wall test specimens gathered from the literature is utilized for developing an ML model, by employing XGBoost, to predict the shear strength. Results verified that the XGBoost model had the best accuracy and least error while assessing the squat walls' strength at shear. Moreover, an XGBoost optimum algorithm fared better than the empirical models based on mechanics, with a 99.2% accuracy. Finally, to prove that the model can identify the most important variables that significantly affect the shear strength, parameter and sensitivity analyses were performed and the results showed that the wall length is the factor that contributes most to the ultimate shear strength of the squat shear wall as a percentage (7.62%), followed by the yield strength. For the web as a ratio. (6.88%), concrete strength (6.75%), reinforcement ratio information (6.56%), and geometric properties (6.01%), while the axial load represents the smallest contribution, reaching (4.16%).

Trap-Mediated Sensitization Governs Near-Infrared Emission from Yb3+-Doped Mixed-Halide CsPbClxBr3-x Perovskite Nanocrystals.

Understanding the photosensitization mechanisms in Yb3+-doped perovskite nanocrystals is crucial for developing their anticipated photonic applications. Here, we address this question by investigating near-infrared photoluminescence of Yb3+-doped mixed-halide CsPbClxBr3-x nanocrystals as a function of temperature and revealing its strong dependence on the stoichiometry of the host perovskite matrix. To explain the observed experimental trends, we developed a theoretical model in which energy transfer from the perovskite matrix to Yb3+ ions occurs through intermediate trap states situated beneath the conduction band of the host. The developed model provides an excellent agreement with experimental results and is further validated through the measurements of emission saturation at high excitation powers and near-infrared photoluminescence quantum yield as a function of the anion composition. Our findings establish trap-mediated energy transfer as a dominant photosensitization mechanism in Yb3+-doped CsPbClxBr3-x nanocrystals and open up new ways of engineering their optical properties for light-emitting and light-harvesting applications.

Dynamic Reconstruction of Two‐Dimensional Defective Bi Nanosheets for Efficient Electrocatalytic Urea Synthesis

AbstractAbstract:Catalyst surface dynamics drive the generation of active species for electrocatalytic reactions. Yet, the understanding of dominant site formation and reaction mechanisms is limited. In this study, we thoroughly investigate the dynamic reconstruction of two‐dimensional defective Bi nanosheets from exfoliated Bi2Se3 nanosheets under electrochemical CO2 and nitrate (NO3−) reduction conditions. The ultrathin Bi2Se3 nanosheets obtained by NaBH4‐assisted cryo‐mediated liquid‐phase exfoliation are more easily reduced and reconstructed to Bi nanosheets with high‐density grain boundaries (GBs; GB‐rich Bi). The reconstructed GB‐rich Bi catalyst affords a remarkable yield rate of 4.6 mmol h−1 mgcat.−1 and Faradaic efficiency of 32 % for urea production at −0.40 V vs. RHE. Notably, this yield rate is 2 and 8.2 times higher than those of the low‐GB Bi and bulk Bi catalysts, respectively. Theoretical analysis demonstrates that the GB sites significantly reduce the *CO and *NH2 intermediate formation energy and C−N coupling energy barrier, enabling selective urea electrosynthesis on the GB‐rich Bi catalyst. This work will trigger further research into the structure‐activity interplay in dynamic processes using in situ techniques.

Passive Biotelemetric Detection of Tibial Debonding in Wireless Battery-Free Smart Knee Implants.

Aseptic loosening is the dominant failure mechanism in contemporary knee replacement surgery, but diagnostic techniques are poorly sensitive to the early stages of loosening and poorly specific in delineating aseptic cases from infections. Smart implants have been proposed as a solution, but incorporating components for sensing, powering, processing, and communication increases device cost, size, and risk; hence, minimising onboard instrumentation is desirable. In this study, two wireless, battery-free smart implants were developed that used passive biotelemetry to measure fixation at the implant-cement interface of the tibial components. The sensing system comprised of a piezoelectric transducer and coil, with the transducer affixed to the superior surface of the tibial trays of both partial (PKR) and total knee replacement (TKR) systems. Fixation was measured via pulse-echo responses elicited via a three-coil inductive link. The instrumented systems could detect loss of fixation when the implants were partially debonded (+7.1% PKA, +32.6% TKA, both p < 0.001) and fully debonded in situ (+6.3% PKA, +32.5% TKA, both p < 0.001). Measurements were robust to variations in positioning of the external reader, soft tissue, and the femoral component. With low cost and small form factor, the smart implant concept could be adopted for clinical use, particularly for generating an understanding of uncertain aseptic loosening mechanisms.