Browse Articles

Reduction of absorption of Ta2O5 monolayers through the suppression of structural defects by employing an appropriate ionic oxygen concentration

Enhancing contact triboelectrification by coupling interfacial spontaneous polarization and permittivity manipulation

The electricity generation of triboelectric nanogenerators (TENGs) originates from charge transfer enabled by contact electrification. However, the inherent barrier between two contacting surfaces hampers the triboelectric charge transfer. There are mainly four ways to promote the triboelectrification of TENGs. While synergy among them has never been achieved. Herein, we reported an effective strategy to boost the triboelectric charge transfer efficiency by synergizing the strong ferroelectric polarization and high permittivity of embedded lead zirconate titanate fillers. The influence of interfacial polarization intensity and the dielectric permittivity, as well as corona poling, on the triboelectrification of composite film was systematically investigated. Notably, the switching of interfacial polarization direction renders an increase (207%) or a decrease (71%) in the triboelectric output in comparison with the non-poled counterpart. Theoretical modeling was established by combining Kelvin probe force microscopy characterization with the electron cloud overlap energy band derivation. This work not only offers unprecedented insight into the fundamental mechanism of triboelectrification but also opens up a possibility in the development of next-generation wearable electronics.

AI language model rivals expert ethicist in perceived moral expertise

Green, efficient, and controllable preparation of In2O3 uniformly modified MoS2 nanoflowers for methanol detection

In2O3 uniformly modified MoS2 (In2O3/MoS2) nanoflowers were synthesized via a green, efficient, and controllable normal-pressure microwave-assisted route and a subsequent calcination process, using MoS2 nanoflowers as substrates. The In2O3/MoS2 nanoflower is composed of extremely thin MoS2 nanosheets, among which In2O3 nanoparticles are uniformly attached to the MoS2 nanosheets. Numerous p–n heterojunctions and oxygen vacancies are present on the surfaces of the In2O3/MoS2 nanoflowers. The In2O3/MoS2 composites exhibited high sensitivity and selectivity, along with rapid response and recovery to methanol vapor at 240 °C. The In2O3/MoS2 nanoflower sensors exhibit rapid response and recovery rates toward methanol, particularly notable with a recovery time of only 15 s for 100 ppm methanol. The In2O3/MoS2 sensors also demonstrate excellent stability and reproducibility, with a remarkable selectivity toward methanol. This research presents a promising approach for the future design and preparation of In2O3/MoS2 composite for methanol detection.

Hydroacoustic sensing of seismic events during the Tajogaite volcanic eruption (La Palma, Spain)

Abstract Volcanic processes generate a variety of seismic events that can be detected by both on-land and underwater sensors. During the 2021 subaerial eruption of the Tajogaite volcano on La Palma Island (Canary Islands, NW Africa), an underwater acoustic sensor was strategically deployed to monitor seismic activity. This study presents marine passive acoustic monitoring data from a moored hydrophone deployed offshore at a depth of 77 m and 7 km from the volcanic vent, both during and after the eruption. We compare hydrophone recordings with island’s seismic network and earthquake database from the Instituto Geográfico Nacional (IGN). By calculating acoustic metrics and analyzing low-frequency bands (< 100 Hz), we identified 712 impulsive acoustic signals consistent with seismic events recorded in the seismic catalogue. These acoustic signals were double-pulsed, low-frequency (≤ 50 Hz with peak frequencies ≤ 15 Hz) and exhibited sound levels that well correlated with earthquake magnitudes. Our findings demonstrate that shallow-water hydro-acoustics can detect and estimate the magnitude of volcano-tectonic earthquakes in the studied scenario. These results encourage for the integration of hydro-acoustic monitoring in conjunction with on-land seismic stations to enhance the overall monitoring of the investigated volcanic area seismic activity.

High-efficient spin injection in Co/GeSn with ferromagnetic resonance driven spin pumping

Germanium tin (GeSn) is one of the candidates for spintronic materials owing to its tunable spin–orbit interaction and barrier height with increasing the Sn content. However, as a potential spintronic material, its spin related properties have not been fully understood yet. We investigate the efficiency of spin current detection in GeSn by using the technique of ferromagnetic resonance drive spin pumping. Some fundamental spintronic parameters can be extracted from our experimental results to measure the change of spin injection/conversion efficiency. A Co layer is deposited on the top GeSn thin films to serve as the spin current generator. Here, the effective spin mixing conductance (geff↑↓) and the product of spin diffusion length and spin Hall angle [λsθISHE(%)] represent the spin injection efficiency and the spin-charge conversion efficiency, respectively. geff↑↓ and λsθISHE(%) are 9.3 × 1019 m−2 and 1.39 nm for p-type GeSn; and 7.4 × 1019 m−2 and 2.09 nm for n-type GeSn. The high-efficient spin injection in both p-type and n-type Co/GeSn systems is attributed to a low barrier height at the Co/GeSn interface because the spin current at the interface is proportional to the square root of barrier height. Our experimental results show that GeSn is effective as a spin current sink.

Exploring novel and potent glycogen synthase kinase-3β inhibitors through systematic drug designing approach

Direction tunable singly polarized excitons in wurtzite monolayer

The optical response with tunable direction and carrier transport are highly desirable for optoelectronic devices. Here, we find a switchable direction dependent singly polarized exciton with E∥x or E∥y mode in the wurtzite (wz) monolayer by the ferroelastic phase transition or external strain. This reversible singly polarized switching is facilitated by valence band inversion, which arises from the reordering of heavy-hole and light-hole states around the valence band maximum in the wz monolayer. Our results facilitate precise modulation of polarized optical transition in two-dimensional materials and paves the way for designing optoelectronic devices with fully controllable polarization transition.

General public takes up counterintuitive expert advice on effective climate action

Abstract Individual voluntary climate action could contribute to closing the gap between global emission targets and the instruments in place. However, complex regulatory frameworks make it difficult for individuals to understand which actions align with their goals. Expert advice might provide guidance, but it is not trivial how detailed the advice should be. In a large consequential choice experiment with five informational load conditions, this paper uses the voluntary cancellation of European Union Allowances as an application to narrow down a minimum amount of information required to induce effective actions. We find a clear pattern of advice being processed and followed, even if it includes a demanding level of detail and counters prior convictions. Moreover, a mere assertion is highly effective already. These results are good news for efforts to increase the effectiveness of voluntary climate action.

Crystal structure manipulation to achieve better thermoelectric performance in Te-substituted GeSe

GeSe has recently gained attention for its structural similarity to SnSe, an excellent thermoelectric material. However, for the orthorhombic GeSe, the maximum zT is limited to ∼0.2 at 700 K. A significant improvement in the thermoelectric performance is observed when GeSe is stabilized in a rhombohedral or cubic structure; thus, the crystal structure plays an important role in GeSe for improved zT. In this study, we investigated the structural transitions and thermoelectric properties of Te-substituted GeSe. Increasing Te substitution in GeSe1-xTex (x = 0.00–0.50) induces a transition from orthorhombic to rhombohedral crystal structure at ambient conditions with the maximum zT ∼ 0.58 observed in rhombohedral GeSe0.6Te0.4 at 573 K. The improved thermoelectric performance in the rhombohedral phase is due to a concurrent increase in the power factor and a decrease in lattice thermal conductivity. The phonon dispersion calculation tells that the high-frequency optical phonon modes significantly increase the phonon–phonon scattering for the rhombohedral phase, enhancing the lattice anharmonicity and reducing the lattice thermal conductivity. This behavior aligns with the presence of metavalent bonding in rhombohedral GeSe. Additionally, peak broadening observed in the Raman spectra of the rhombohedral phase indicates pronounced lattice anharmonicity and phonon modes softening due to the metavalent bond character.

Maximizing temperature sensitivity in a one-dimensional photonic crystal thermal sensor

Abstract This paper focuses on a defective one-dimensional photonic crystal thermal sensor with fabricated layers of gallium nitride, glycerin, and air. The transmission features of this sensor have been presented based on the transfer matrix approach using MATLAB software. Interest in the sensor’s sensitivity to temperature variation is for the sake of the photonic bandgap behavior of the 1D photonic crystal and the thermo-optic effect of glycerin must be preserved over a long time in protecting archaeological artifacts. In this direction, theoretical modeling together with numerical simulation studies are conducted to optimize the refractive index of GaN to enhance sensitivity. This work is going to evaluate the performance of the sensor in terms of the shift in the transmission spectrum of the sensor with the imposition of changes in temperature. The effect of the thickness of the defect layer together with the incident angle on the performance of the sensor will be discussed further. Sensor sensitivities are about 10 nm/°C, with a quality factor reaching a high value of 35,443 at an incident angle of 30°, while sensitivities at an incident angle of 65° have 20 nm/°C and a quality factor of 14,723.

Thermal emission modulation of fabrication-friendly, free-form metasurfaces via explainable deep-learning Bayesian optimization

Free-form metasurfaces with superimposed transformative meta-atoms provide a versatile platform to realize cross-band thermal emission control. However, design and manufacturing of free-form metasurfaces is extremely challenging, owing to the complex and fractal sub-wavelength topology. Here, we address these two issues by proposing an explainable deep-learning Bayesian optimization (DeepBO) framework to realize a library of fabrication-friendly, free-form metasurfaces with different light–matter interaction bandwidths. The DeepBO requires only 50 training data and is capable of screening high-dimensional design space of 1043 thermal photonic structure candidates with bandwidths from 0.3 to 3.2 eV. We unfold the black-box of deep-learning process by pattern recognition and identify the sub-space key features in the high-dimensional design space, which provides insights for thermal photonic metasurface design. We showcase the design and manufacturing of the broadband solar absorber and the narrowband thermophotovoltaic emitter with record-high spectral efficiency. The spectral selectivity of the fabricated free-form metasurface matches well with the design. The fabrication-friendly, free-form metasurfaces realized in this work can be generalized to thermal emitters for broad-ranges applications in energy and sensing.

Exploring Echinacea angustifolia for anti-viral compounds against Zika virus RNA-dependent RNA polymerase: a computational study

Abstract The Zika virus (ZIKV), a member of the Flaviviridae family, has caused multiple widespread outbreaks, posing significant challenges to global health. This study explores the potential of compounds from Echinacea angustifolia (E. angustifolia) to inhibit the activity of ZIKV’s RNA-dependent RNA polymerase (RDRP), a key enzyme in the viral replication process and an ideal candidate for antiviral therapy. Utilizing computational techniques, we conducted a thorough virtual examination using the MTi-OpenScreen tool to identify potential RDRP inhibitors among E. angustifolia compounds. The top four compounds were further examined through re-docking procedures. To assess the robustness and effectiveness of these interactions, we performed molecular dynamics simulations along with calculations of the binding free energy and PCA analysis. This investigation highlighted four naturally occurring compounds, viz., Echinacoside, Rutin, Echinacin, and Cynaroside, demonstrating a notable affinity for binding to the allosteric site of ZIKV RDRP. These compounds showed strong hydrogen bond formation with crucial residues of the RDRP and presented favorable binding free energies. Our research sheds light on the viability of these E. angustifolia compounds as ZIKV RDRP inhibitors, laying a foundation for further experimental research in developing novel antiviral treatments against ZIKV infections.

I spent a year studying campus sexual violence. Here’s what I found out

Asymmetric contact structure enables fast response of Bi2O2Se photodetectors

The near-infrared (NIR) photodetector is an important component in the realm of photodetectors. Bi2O2Se, with its narrow bandgap of 0.8 eV, has emerged as a promising candidate for NIR detection. However, it exhibits a slower response in this spectral region. An asymmetric electrode structure can effectively separate photogenerated electron–hole pairs by introducing an internal electric field, thereby facilitating faster carrier transport and significantly reducing the response time. In this study, we utilized PdSe2, a semi-metal, as an electrode to construct an asymmetric electrode structure in conjunction with Ti–Au electrode, aiming to enhance the performance of Bi2O2Se NIR photodetectors. The response time of the PdSe2/Bi2O2Se/Ti–Au photodetector was 21 and 16 μs under 1064 and 1550 nm light sources, respectively, with a responsivity of 121 mA/W at 1064 nm. These findings underscore the potential of this design in advancing infrared detection technology.

Fault analysis and fault degree evaluation via an improved ResNet method for aircraft hydraulic system

Robust adaptive optimization for sustainable water demand prediction in water distribution systems

MiR-25-3p regulates pulmonary arteriovenous malformation after Glenn procedure in patients with univentricular heart via the PHLPP2-HIF-1α axis

Exploring biomarkers and molecular mechanisms of Type 2 diabetes mellitus promotes colorectal cancer progression based on transcriptomics

Abstract Type 2 diabetes mellitus (T2DM) has been confirmed as an independent risk factor for colorectal cancer (CRC) in many studies. However, the mechanisms behind T2DM’s role in the progression of CRC remain unclear. This study aims to explore the potential biomarkers and molecular mechanisms involved in T2DM-promoted CRC progression. The limma package was used to identify differentially expressed genes in tumor tissue from CRC patients with or without T2DM. The key biological processes were screened by gene ontology and gene set enrichment analysis. A diagnostic model for co-morbidities was constructed by logistic regression model with least absolute shrinkage and selection operator (Lasso) regularization method. The diagnostic performance was assessed by supplementing external datasets to draw ROC curves on the diagnostic model. The diagnostic model was further screened for key genes by prognostic analysis. The relationship of key genes with immune cells and other cells was evaluated by immune infiltration algorithm and single-cell transcription analysis. Drug prediction was performed by cMAP and the obtained drugs were molecularly docked with the key genes. The differentially expressed genes of T2DM-promoted CRC progression were mainly enriched to O-linked glycosylation-related processes. The diagnostic model constructed based on Lasso logistic regression had good diagnostic performance (AUC > 0.8). COX11 was the key gene for co-morbidities: in tumor tissues, COX11 expression was significantly higher than that in normal colon tissues. However, COX11 gene expression was significantly lower in patients with comorbidities than in patients without T2DM in tumor tissue. External datasets confirmed from both mRNA and protein expression levels that low COX11 expression was significantly associated with poor CRC prognosis. Immune infiltration analysis suggested that its expression related to the proportion of M2 macrophages. Single-cell transcriptome analysis revealed a close association of COX11 expression with endothelial cells and macrophages. The top4 drugs predicted bound well to COX11. Our study revealed that the pathogenesis of T2DM-promoted CRC progression related to O-linked glycosylation. We constructed a diagnostic model for T2DM-CRC co-morbidity. Meanwhile, we identified COX11 as a potential immune-related molecular marker closely associated with T2DM-promoted CRC progression. These mechanisms and molecular markers may provide new ideas for further studies of T2DM-promoted CRC progression and contribute to drug discovery for the treatment of co-morbidities.

Microtubule inhibition as a proposed mechanism for the anthelmintic effect of phytochemicals isolated from Cicerbita alpina

Abstract The alpine plant Cicerbita alpina (L.) Wallr., when grown as a sprout, is known as a bitter-tasting culinary delicacy. Recently it has also been reported to have anthelmintic activity, prompting further investigation into its mechanism of action. Liquid–liquid fractions were prepared from a methanolic extract of the aerial parts and were submitted in parallel to embryo development (ED), worm motility (WMT), and cytotoxicity assays for anthelmintic and toxicity evaluations. The anthelminthic assays revealed the more polar fractions to be most active against Ascaridia galli embryos (BuOH | 68% ED | c = 500 µg/ml and EtOAc | 65% ED | c = 500 µg/ml) and Caenorhabditis elegans adult worms (BuOH | 49% WMT | c = 150 µg/ml and EtOAc | 74% WMT | c = 150 µg/ml) suggesting the fraction’s constituents possess dual anthelmintic activity against multiple life-cycle stages (i.e., eggs, worms) of helminths. Additionally, the BuOH fraction was non-cytotoxic to human cell-lines. Subsequent FCC and SEC derived subfractions were submitted to the anthelmintic assay workflow and the enriched subfractions B1 and E3.8, phytochemically assigned as 11-β,13-dihydrolactucin and luteolin, demonstrated bioactivity against the embryo phenotype (B1 | 58% ED | c = 1.8 µM and E3.8 | 46% ED | c = 1.7 µM) within range of the flubendazole control. Furthermore, luteolin was found to inhibit C. elegans egg hatching (luteolin | 65% EH | c = 10 µM | t = 10 h) within the range of the control albendazole. Both identified anthelmintic phytochemicals were found to affect tubulin polymerisation at a concentration of c = 50 µM. Together with in silico virtual screening studies, these results suggest microtubule stabilisation as a possible anthelmintic target and mechanism of action. This work effectively advocates the consideration of C. alpina extracts and fractions for the development of herbal therapeutics against parasitic helminths.