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Enhanced tunnel magnetoresistance of Fe/MgGa2O4/Fe(001) magnetic tunnel junctions by interface-tuning with atomic-scale MgO insertion layers

We demonstrate a significant effect of atomic-scale MgO insertion layers on the tunnel magnetoresistance (TMR) in epitaxial magnetic tunnel junctions (MTJs) using a small bandgap oxide MgGa2O4. An enhanced TMR ratio of 151% at room temperature (resistance area product, RA: 23 kΩ ⋅ μm2) and 291% at 5 K (RA: 26 kΩ ⋅ μm2) were observed using 0.3 nm MgO insertion layers at the bottom and top barrier interfaces in Fe/MgGa2O4/Fe(001) MTJs with a total barrier thickness of 2.3 nm. The TMR showed a strong MgO thickness dependence. Microstructure analyses revealed that after MgO insertion, a homogeneous rock-salt structured Mg0.55Ga0.45O(001) barrier is formed, which differs from the nominal spinel crystal MgGa2O4. Elemental mapping of the MTJ showed that Ga diffusion into the adjacent Fe can be effectively suppressed while maintaining perfect lattice-matching at the Fe/barrier interfaces, thereby improving effective tunneling spin polarization through the barrier. The RA of the Mg0.55Ga0.45O (2.3 nm) MTJ is smaller than that of a comparable MgAl2O4 barrier (2.3 nm), thanks to the lower barrier height of the Mg0.55Ga0.45O as confirmed by the current–voltage characteristics.

Selective fluoride ion sensing using novel quinoline chemosensor insights into kinetics and molecular logic gate functions

Segregation-induced co-passivation effect of S and Cl on CdTe grain boundaries

The efficiency of polycrystalline CdTe solar cells can be significantly enhanced through CdCl2 treatment. However, while this treatment promotes the diffusion of sulfur (S) into CdTe, the improvement cannot be solely attributed to chlorine (Cl); S may also play a crucial role. In this study, using first-principles calculations, we investigated the effects of S and Cl co-doping on the electronic properties of CdTe Σ3 (112) Te-core GBs. The Σ3 (112) Te-core GBs present challenges due to deep gap states caused by Te-Te and Cd-Cd wrong bonds. Notably, the segregation behavior of S dopants within the GBs suggests their potential to significantly influence the electronic properties. When co-doped with Cl, it is evident that S is more likely to occupy interstitial sites rather than substituting for Te atoms under Te-rich conditions. The co-passivation of S and Cl at the GBs can eliminate all gap states, thereby enhancing electrical performance. These findings provide insights into the synergistic effects of dopants on GBs and propose a promising strategy to improve the performance of CdTe solar cells through doping.

Efficacy of melatonin treatment in a cystic fibrosis mouse model of airway infection

Strong out-of-plane piezoelectric properties in Janus PdXY (X, Y = O, S, Se, Te; X ≠ Y) monolayers: A first-principles study

The development of piezoelectric materials is limited by incomplete internal mechanisms and a lack of vertical piezoelectricity. This study introduces Janus PdXY (X, Y= O, S, Se, Te; X ≠ Y) monolayers as innovative candidates for superior piezoelectric performance, as predicted by density functional theory. Our study reveals that these materials possess exceptional in-plane and out-of-plane piezoelectric properties, with the out-of-plane coefficient d33 being up to two orders of magnitude greater than that of conventional Janus materials. This enhancement is attributed to the electron contributions and correlates with the Bader charge difference and electronegativity difference ratio, which conforms to the P-R mechanism. Additionally, the impact of layer thickness on piezoelectric coefficients is evaluated. These findings highlight the potential of Janus PdXY monolayers for advanced nanoscale flexible piezoelectric devices and offer valuable insights for the design of transition metal dichalcogenide-based Janus materials with robust out-of-plane piezoelectricity.

Experimental study on the influence of lapping plate materials on the quality of both sides cylindrical rollers machining

Direct laser writing of planar and stretchable supercapacitors based on a graphene oxide and manganese dioxide nanoparticle composite on a paper substrate

Paper-based supercapacitors (P-SCs) exhibit superior electrochemical performance owing to the flexibility and unique surface properties of paper substrates. Currently, most P-SCs adopt a sandwich structure that is limited by electrode fabrication methods. However, the development of planar paper-based devices is crucial to satisfy the tremendous demand for wearable electronics. Herein, based on the mechanism of interaction between the laser and material, we used direct laser writing (DLW) techniques to fabricate in-plane P-SCs based on graphene oxide (GO) and manganese dioxide (MnO2) composite-covered paper substrates. Owing to the in-plane device structure and pseudocapacitive MnO2, the acquired rGO-MnO2-based planar P-SCs possessed a much higher specific capacitance value (17.7 mF/cm2) than that based on sandwich-structured reduced GO (rGO) (1.71 mF/cm2). In addition, three in-series integrated devices can be easily achieved via the DLW fabrication method, which shows potential for practical applications such as powering a light emitting diode. In addition, by carefully designing the paper substrate structure, the paper-based device exhibited excellent stretching stability. A specific capacitance retention of 86.8% remained after 5000 stretch cycles. Therefore, this study provides valuable insights into the design and fabrication of wearable paper-based electronics.

Development of immune-derived molecular markers for preeclampsia based on multiple machine learning algorithms

Origin of oxygen partial pressure-dependent conductivity in SrTiO3

SrTiO3 (STO) displays a broad spectrum of physical properties, including superconductivity, ferroelectricity, and photoconductivity, making it a standout semiconductor material. Despite extensive research, the oxygen partial pressure-dependent conductivity in STO has remained elusive. This study leverages first-principles calculations and systematically investigates the intrinsic defect properties of STO. The results reveal that VO, VSr, and TiSr are the dominant intrinsic defects, influencing STO's conductivity under varying O chemical potentials (oxygen partial pressures). Under O-poor condition, VO is the predominant donor, while VSr is the main acceptor. As the oxygen pressure increases, TiSr emerges as a critical donor defect under O-rich conditions, significantly affecting the conductivity. Additionally, the study elucidates the abnormal phenomenon where VTi, typically an acceptor, exhibits donor-like behavior due to the formation of O-trimer. This work offers a comprehensive understanding of how intrinsic defects tune the Fermi level, thereby altering STO's conductivity from metallic to n-type and eventually to p-type across different O chemical potentials. These insights resolve the long-standing issue of oxygen partial pressure-dependent conductivity and explain the observed metallic conductivity in oxygen-deficient STO.

Study of blood flow patterns in a stenosed artery through the combined effect of body acceleration and generalized womersley solution

Abstract Stenosis causes the narrowing of arteries due to plaque buildup, which impedes blood flow and affects flow dynamics. This work numerically analyzes flow fluctuations in stenosed arteries under realistic physiological conditions (resting and exercise) and external body acceleration. The artery is inclined at angle $$\Theta$$ Θ , and blood rheology is modeled using a generalized power-law fluid. A modified two-dimensional SIMPLE pressure-correction-based numerical solver with orthogonal coordinate transformation simulates blood flow. A generalized Womersley solution is imposed at the inlet. We validate the solver and perform simulations to assess the influence of geometric and flow parameters, analyzing time-averaged and phase-averaged data. We investigate the correlation between hyperviscosity and physiological conditions, finding that exercise increases recirculation downstream of the stenosis. We also study the impact of transitioning between resting and exercise conditions, noting that the transition rate correlates with stenosis development, indicating potential complications.

Heat-powered IoT node: A synergistic fusion of thermoacoustic engine and triboelectric nanogenerator

This study presents the design and analysis of a thermal energy harvester that integrates a thermoacoustic engine (TAE) with a honeycomb-structured triboelectric nanogenerator (H-TENG), referred to as TAEH-TENG. This design is specifically developed to demonstrate the potential of thermal energy harvesting for low-power Internet of Things (IoT) applications. By leveraging the high energy conversion efficiency of TAEs and the exceptional robustness of H-TENGs, this harvester overcomes the limitations of traditional designs, which often involve complex or costly components. The experimental results revealed the oscillation characteristics of the TAEH-TENG: by utilizing a hot heat exchanger (HHE) with a length of 10 cm, the system can sustain oscillation over 150–350 °C. Furthermore, the harvester is capable of generating an open-circuit voltage of 25 V, an RMS current of 0.98 μA, and a peak power output of 0.48 mW, representing the highest power output achieved to date in comparison to previous studies. To further showcase the harvester's capability, an ultra-low-power IoT node was developed. Solely powered by the TAEH-TENG, the IoT node achieved cold-start, conducted in situ temperature measurement five times, and transmitted the data via Bluetooth within 120 s. This study not only showcases a fully self-powered IoT application but, more importantly, significantly advances the technology beyond the previous limitations faced by thermoacoustic and triboelectric integrations. By demonstrating the capability to power an ultra-low-power IoT node, this research highlights the TAEH-TENG's potential for practical, real-world energy solutions, marking a significant milestone in the deployment of heat-powered IoT applications.

Author Correction: Yindanxinnaotong, a Chinese compound medicine, synergistically attenuates atherosclerosis progress

Publisher's Note: “Extremely weak sub-kelvin electron–phonon coupling in InAs on Insulator” [Appl. Phys. Lett. <b>125</b> , 202601 (2024)]

Integrated intraoperative predictive model for malignancy risk assessment of thyroid nodules with atypia of undetermined significance cytology

Indium alloying in <b> <i>ε</i> </b>-Ga2O3 for polarization and interfacial charge tuning

Density functional theory was utilized to assess the influence of In alloying on the spontaneous (Psp) and piezoelectric (Ppe) polarization of ε-Ga2O3 heterostructures with In concentrations ranging from 0% to 50%. The analysis demonstrated a decrease in both Psp and Ppe with an increase in In concentration, described by the equations Psp = −9.5947x + 24.81 and Ppe = −0.6217x (where x represents the In concentration, with units in μC/cm2). Additionally, the polarization-induced two-dimensional electron gas (2DEG) density within ε-InGaO/ε-Ga2O3 heterostructures was examined using a one-dimensional Schrödinger–Poisson solver. An inverse correlation was observed between 2DEG density and epitaxial thickness across all undoped In-alloyed samples. Furthermore, achieving high 2DEG densities (exceeding 1013 cm−2) is significantly facilitated by n-type doping concentrations above 1017 cm−3 in ε-InGaO. These insights not only augment the understanding of polarization effects in ε-Ga2O3 heterostructures but also provide a strategic framework for enhancing 2DEG density in ε-Ga2O3-based devices, which offers significant potential for advancing ε-Ga2O3-based high electron mobility transistors for power and RF applications.

Spermine driven water deficit tolerance in early growth phases of sweet corn genotypes under hydroponic cultivation

Abstract Sweet corn is highly susceptible to water deprivation, making it crucial to identify effective strategies for enhancing its tolerance to water deficit conditions. This study investigates the novel application of Spermine as a bio-stimulant to improve sweet corn (Zea mays L. var. saccharata) resilience under hydroponic water deficit conditions. Four genotypes (Dessert, Messenger, Tyson, and Royalty) were treated with Spermine (0.2 mM foliar application), polyethylene glycol 6000 (8% and 12%), and their combinations. The impacts on growth parameters, photosynthetic performance, and oxidative stress markers were evaluated. Spermine significantly enhanced biomass parameters, counteracting the severe reductions caused by PEG-induced water deprivation. In the Dessert and Tyson genotypes, total biomass increased by 145%, while it increased by 118% in Messenger and 110% in Royalty when treated with Spermine under severe water deprivation. However, Spermine treatment application did not recorded higher differences compared to control under non water deficit conditions. In the Dessert genotype, root length increased by 36.6% under combined treatment compared to 12% PEG alone. Spermine also mitigated reductions in shoot length, improved by 90.6% and specific leaf area, with a notable 272.6% increase in Tyson under severe water deficit. Photosynthetic performance, including chlorophyll and carotenoid levels, was enhanced, with a 103.1% increase in relative chlorophyll content in Dessert under severe water deprivation. Spermine also reduced oxidative damage, as indicated by a 48.7% decrease in malondialdehyde levels in Tyson, and increased peroxidase activity, enhancing antioxidant defense in Messenger under severe water deprivation. The quantum efficiency of Photosystem II, which was significantly reduced by water deficit, showed substantial improvement with Spermine treatment, with increases of 107.2% in Tyson and 99.4% in Royalty under moderate water deprivation. These results highlight the potential of Spermine as an effective strategy to improve sweet corn resilience under water-limited conditions, offering a novel approach for sustainable crop management.

Doping-induced enhancement of Curie temperature in Zn2Ru1−<i>x</i>A<i>x</i>Mn (A = Ti, Mn, Co, Zr, and Rh) Heusler alloys: An <i>ab initio</i> investigation

This study examines the structural stability, electronic, and magnetic properties of off-stoichiometric Zn2Ru1−xAxMn Heusler alloys (with, A = Ti, Mn, Co, Zr, and Rh) using first-principles calculations. We find that the L21 phase is more stable than the XA phase across both ordered and disordered configurations. The variations in lattice parameters with off-stoichiometry are attributed to the atomic radii of the dopants. Our results indicate that Zn2Ru1−xAxMn alloys exhibit ferromagnetic metallic behavior, driven primarily by Mn-Mn, Ru-Mn, and A-Mn exchange interactions. These interactions are further analyzed to calculate the Curie temperature using the mean-field approximation. The Curie temperature for Zn2RuMn is found to be approximately 300 K, which increases to 428 K upon Co doping. Our findings suggest that doping provides a means to control the Curie temperature, offering substantial potential for applications in room-temperature magnetocaloric materials and shape memory alloys. This tunability enhances the functional versatility of these alloys, making them promising candidates for future technological applications.

Hybrid stochastic and robust optimization of a hybrid system with fuel cell for building electrification using an improved arithmetic optimization algorithm

Low voltage and high bandwidth surface-illuminated three-terminal Ge-on-Si APD with multiple biasing configurations

In this work, a regulated-voltage biasing configuration is proposed for the Ge-on-Si avalanche photodiode (APD) structure. This design incorporates an extended n-charge layer to decrease the breakdown voltage and optimizes the absorption region thickness to reduce the electron transit time. By applying three electrodes to individually modulate the electric fields in the absorption and avalanche region, respectively, both of low avalanche breakdown voltage (−8.1 V) and high bandwidth (20.4 GHz) of the surface-illuminated detector can be achieved. Meanwhile, the sensitivity of weak light detection is improved to −45 dBm. The responsivity of the APD is 60.76 A/W at 1550 nm when the voltage is biased at −13.5 V. The low voltage and improved bandwidth can meet the requirements for weak light detection and other applications demanding such sensitivity.

Serum assisted PD-L1 aptamer screening for improving its stability