Browse Articles

Utilizing the transverse thermoelectric effect of 4H-SiC for infrared laser detectors across a power range spanning from milliwatts to hundreds of watts

In this work, infrared (IR) laser detectors have been designed and fabricated based on the transverse thermoelectric effect of c axis tilted n-type 4H-SiC homoepitaxial materials. The power measurement range of such detectors has been checked by a 940 nm laser with low power (31–186 mW) and a 1080 nm laser with high power (25–150 W). It is shown that the detectors can operate in a wide range of laser powers, with a minimum power threshold of 31 mW and a maximum detection capability of 150 W. The sensitivity in such a wide power range is almost a constant of around 7.53 μV/W, within the consideration of the absorption coefficient difference between 940 and 1080 nm. This also indicates that such detectors can work in a wide range of IR wavelengths by normalizing the absorption coefficient. In addition, these 4H-SiC detectors demonstrate remarkable stability under thermal cycling tests between cryogenic (−197 °C) and extreme high-temperature (1000 °C) conditions. These findings may provide an effective solution for fabricating IR laser detectors capable of operating across 5 orders of magnitude (milliwatts to hundreds of watts) while withstanding harsh environments.

Hyperpolarized [1-13C]pyruvate NMR spectroscopy reveals transition of tumor energy metabolism in microscale multicellular spheroids

Research on two-stage dynamic optimization model and algorithm for agricultural products joint distribution network based on vehicles and customers sharing under data-driven

Urban road traffic congestion and new customers and customer demands change in the distribution process have brought great challenges to the distribution of agricultural products. Meanwhile, the development of smart logistics makes it possible to share distribution resources, which can provide good help for the efficient distribution of agricultural products. Compared with the static optimization of the distribution network when traditional single enterprise distributes agricultural products, how to dynamically optimize the distribution network of agricultural products under resource sharing has become an urgent problem to be solved. Based on this, this paper takes the joint distribution network of agricultural products as the research object. Firstly, from the perspective of data-driven, it crawls the historical data of driving speed through Baidu map big data platform, and uses a BP neural network optimized by genetic algorithm to predict the driving speed of vehicles in different periods. Secondly, based on the idea of pre-optimization and dynamic adjustment, a two-stage dynamic optimization model of agricultural products joint distribution network under vehicles and customers sharing is established. On this basis, considering the changes of customer demands and the speed of distribution network, a partheno-genetic hybrid simulated annealing algorithm is designed to solve the model by using the idea of disruption event processing combining immediate processing and scheduled batch processing. Finally, the correctness of the model is analyzed through numerical experiments, and the effectiveness of the proposed algorithm, the joint distribution strategy, and the disruption event processing idea of combining immediate processing and scheduled batch processing is analyzed. The research results provide a theoretical basis for agricultural products distribution enterprises to formulate efficient and scientific joint distribution scheme.

Coexistence of the composition and temperature-induced anomalies in enhancing the dielectric and energy storage properties of (Na0.5Bi0.5)TiO3-based piezoceramics

In high-performance piezoelectric ferroelectric materials like Pb(Zr,Ti)O3, significant properties are linked to composition-induced ferroelectric phase boundary, commonly referred to as the morphotropic phase boundary (MPB). Our investigation into (Na0.5Bi0.5)TiO3-Ba(Ti0.98Zr0.02)O3 revealed not only a typical MPB anomaly at a critical composition but also an additional temperature-induced dielectric anomaly associated with the ferroelectric–relaxor transition (TF-R, Td), which occurs near room temperature for the same composition. Consequently, the enhanced properties have been attributed to the presence of both anomalies. High-resolution transmission electron microscopy imaging has demonstrated that the coexistence of these two anomalies leads to the miniaturization of nanodomains, resulting in a high density of interfaces or domain walls.

Association between attention-deficit/hyperactivity disorders and intestinal disorders: A systematic review and Meta-analysis

Abstract Patients with attention-deficit hyperactivity disorder (ADHD) reported significantly more constipation and flatulence than healthy controls. An altered gut microbiome can be associated with gastrointestinal symptoms. However, comprehensive information about associated risk of intestinal disorders and ADHD remains limited. A systematic review of the literature was therefore conducted to investigate the association between ADHD and different types of intestinal disorders. A total of 11 studies with 3,851,163 unique individuals, including 175 806 individuals with ADHD and 3 675 357 individuals without ADHD were included. The pooled OR of intestinal disorders for individuals with ADHD was 1.25 (95%CI, 0.75–2.07). A significant positive association was found between ADHD and irritable bowel syndrome (IBS) (OR 1.63 [95% CI 1.45–1.83]). Studies conducted in Eastern Mediterranean Region yielded a summary OR estimate that was higher than summary OR estimates in studies conducted in Region of the Americas, European Region and Western Pacific Region (3.03 [1.53–5.99] vs. 2.20 [1.05–4.63], 1.04 [0.44–2.41], 0.68 [0.25–1.87]), with p value 0.053, indicating a trend towards significance. High heterogeneity was observed. Our study supports association between ADHD and increased risk of IBS. Our study suggests an altered gut microbiome is the potential link that bridges gap between ADHD and intestinal disorder.

Prevalence and determinants of allergic rhinitis among high school students exposed to industry allergens in Eastern Ethiopia

Introduction Allergic rhinitis (AR), a common chronic disease triggered by allergens, often leads to school absenteeism in students. Investigating its magnitude and risk factors may play an important role in preventing the disease. Hence, this study aimed to assess the prevalence of allergic rhinitis and associated factors among high school students living in industrial areas in Eastern Ethiopia. Methods A school-based cross-sectional study design was conducted in September 2023 among 442 randomly selected high school students. Data was collected using a structured self-administered questionnaire. Questions on allergic disease symptoms were based on the International Study of Asthma and Allergies in Children (ISAAC) core allergy and environmental questionnaire. Binary logistic regression analysis was done to identify the factors associated with allergic rhinitis. Finally, Adjusted Odds Ratio (AOR), 95% Confidence interval and P-value less than 0.05 was used to judge the statistical significance. Results This study found that the magnitude of allergic rhinitis was 20.7% (95% CI: 17.0%, 24.8%). Similarly, this study identified that a family history of allergic rhinitis (AOR: 2.99, 95% CI: 1.42–6.29) and living with a smoker in the household (AOR: 3.63, 95% CI: 1.22–10.78) were significant risk factors. Conversely, living in a house far from traffic roads (AOR: 0.32, 95% CI: 0.15–0.67) and far from factories (AOR: 0.10, 95% CI: 0.03–0.31) were protective factors against allergic rhinitis. Conclusions The current study found a lower magnitude of allergic rhinitis compared to the previous studies conducted in African countries. Having a smoker family member, distance between the house and nearest traffic road, distance between the house and nearest factory, and family history of allergy rhinitis were factors associated with allergy rhinitis. Hence, provision of health education to encourage people to stop smoking is strongly recommended. Similarly, persons with a family history of allergic rhinitis should minimize exposure to polluted environment and other trigger factors.

Strain-enhanced trion emission in monolayer WS2 modulated by an ion-gel electrochemical gate

The abundant light–matter interactions in monolayer WS2 make the manipulation of exciton states a fascinating endeavor. Utilizing photoluminescence spectroscopy, we investigated strain-induced red shifts and trion enhancement in a WS2 monolayer on a PET/PVA substrate with a Li+ ion-gel electrolyte gate. A notable red shift of the exciton emission peak was observed, increasing by ∼41 meV/%, up to a maximum strain of 2.5%. The combination of ion-gel and strain effectively modulated the radiative recombination, leading to a significant enhancement of the trion peak, with IXT/IX0 rising from 0.95 to 13.12 under 1.21% strain and 6.8 × 1012 cm−2 electron concentration. This enhancement is attributed to strain-induced changes in scattering channels between valleys and indirect bandgap excitation processes. Our study underscores the potential of coupling strain and ion-gate-induced doping for tuning excitonic behaviors in flexible quantum devices.

AI-driven mangrove mapping on Farasan Islands, Saudi Arabia: enhancing the detection of dispersed patches with ML classifiers

Development of a novel and viable knock-in factor V deficiency murine model: Utility for an ultra-rare disease

Factor V deficiency is a congenital coagulation disorder characterized by the absence or malfunction of factor V (FV). The purpose of this study was to develop a viable FV-deficient mouse model using CRISPR/Cas9 technology. A viable pathological model of the disease was not available to develop new therapies. A previous in silico study was performed to select a mutation causing a mild disease phenotype in humans (Thr1898Met missense). Such mutation was replicated in mice by CRISPR-mediated homology directed repair. Following crossing, homozygous individuals were subjected to coagulometry assays, including FV levels, prothrombin time (PT), and activated partial thromboplastin time (aPTT). The in silico study suggested that the mutation destabilizes FV structure of both mouse and human variants, putatively producing a mild phenotype of the disease in mice. Mendelian inheritance was observed in the offspring. No spontaneous signs of blood clotting disturbances, premature deaths or gestational dysfunctions were observed. FV levels in homozygous animals were 24.5% ± 5.1; 39.7 sec ± 2.8; PT was 61.8% ± 6.3; 23.4 sec ± 1.6 (INR = 1.47 ± 0.12); and aPTT was 46.9 sec ± 3.2. A viable FV-deficient mouse model was generated by introducing a missense mutation in FV. The model exhibits a mild phenotype of the disease, akin to that observed in humans.

Phase-driven complex-valued network for quantitative microwave-induced thermoacoustic tomography

Deep learning has demonstrated significant strides in the field of microwave-induced thermoacoustic imaging, achieving superior imaging accuracy compared to conventional methods. However, the current end-to-end reconstruction networks predominantly process time-domain signals while overlooking the critical influence of sensor–tissue spatial relationships on feature extraction, which may degrade imaging fidelity. To address this, we propose a complex-valued neural network architecture for quantitative reconstruction of microwave thermoacoustic conductivity. The proposed framework incorporates two essential components: a 2D Fourier transform operator that converts sensor signals into spatial-frequency representations and complex-valued matrix operations that synergistically optimize amplitude-phase feature learning. Comprehensive numerical simulations and experiments validate that our method achieves higher indicators compared to conventional algorithms and real-valued networks, establishing a state-of-the-art framework in conductivity map reconstruction.

Regeneration and rooting of the endangered Juniperus excelsa as affected by different culture media

Perspectives of healthcare providers in family planning centers on increasing pre-exposure prophylaxis uptake among women who have migrated from sub-Saharan Africa to France

Pre-exposure prophylaxis (PrEP) for HIV remains largely underused among women who have migrated from sub-Saharan Africa (WMSSA), despite their accounting for a significant proportion of new HIV diagnoses in France and Western European countries. To expand PrEP reach, we explored healthcare providers’ perspectives on PrEP implementation within family planning centers (FPCs) in the Paris region through focus groups. The focus group discussion guide and rapid content analysis were informed by the Consolidated Framework for Implementation Research (CFIR) 2.0, which uses five domains to capture implementation determinants (Innovation, Outer Setting, Inner Setting, Individuals, and Implementation Process). Twenty providers participated across five focus groups and one key informant interview (median age 45; 80% women, 70% physicians). Oral PrEP was seen as easy to prescribe, but providers advocated for choices beyond the daily pill for better acceptability. While providers recognized increased HIV prevention needs among WMSSA, they found low PrEP demand among women stemming from a lack of knowledge. Although providers acknowledged that PrEP aligned with FPC missions, they cited significant implementation barriers, including limited resources, staff shortages, insufficient on-site capacity, competing priorities, and physicians being the sole prescribers. Provider-level implementation challenges included insufficient training and discomfort in discussing HIV risk and PrEP with WMSSA. Recommendations for implementing PrEP within FPCs included provider training and mentorship, tailored information campaigns for WMSSA, flexible delivery processes, support groups for women, and authorizing midwives and nurses to prescribe PrEP. These results support the need for tailored and multi-level implementation strategies to increase PrEP uptake among WMSSA attending FPCs in France.

Huge high-temperature superelasticity and complete strains recovery above 773 K in Ni–Mn–Ga-based microwire

There is an urgent need to develop high-performance high-temperature shape memory alloys (HTSMAs) that can be used as smart components in the fast-developing aerospace, robotics, manufacturing, electricity plant, and energy exploration industries. Here, a high-performance (Ni55.5Mn23.5Ga21)99.65B0.3Ce0.05 HTSMA microwire has been developed. Owing to the oligocrystalline structure and favorable orientation, the microwire shows huge superelasticity from 623 to 783 K, with a maximum recoverable strain up to 16.2% and recoverable strains above 14.0% in the whole temperature range. Meanwhile, the irrecoverable strains of the microwire were less than 0.24% during unloading in the temperature range from 673 to 783 K. These properties are in sharp contrast to the typical HTSMAs that display rapid increase in the irrecoverable strains and fast degradation of the recoverable strains above 673 K. Noticeably, all the irrecoverable strains reduced to zero, and complete strains recovery were achieved, after heating to higher temperature. Combined with the advantages of high-temperature superelasticity and complete strains recovery above 773 K, small size, low cost, and easy fabrication, the microwire shows a great potential in small-scale high-temperature intelligent devices.

The effect of intelligent reflecting surfaces on spectral efficiency in 6G wireless systems

Abstract Intelligent Reflecting Surfaces (IRSs), comprised of numerous reflecting elements, offer a promising solution for enhancing wireless communication. By manipulating the wireless propagation environment, IRSs can mitigate the effects of non-line-of-sight propagation and extend signal coverage. This paper focuses on the performance of an IRS-aided wireless communication system when the direct link between the Base Station (BS) and receiver is obstructed, relying solely on the IRS for signal transmission, by using the pilot transmission and channel least square method in calculation of the received signal. We investigate the impact of IRS element components (effective capacitance $$C$$ , bottom layer inductance $${L}_{1}$$ , top layer inductance $${L}_{2}$$ , and effective resistance R) and the frequency of the incident signal on system performance. These components significantly have an influence on reflection coefficients, where higher values of them leads to an increase in the amplitude response of reflection coefficient and hence, stronger reflected signals. The variation of those components can adjust the phase response of the reflected signal. In this paper, assessment of performance of IRS-aided 6G wireless communication system for single user is studied. The received power, SNR, and the spectral efficiency were estimated and used as metrics for the system performance. It has been cleared that the received power, SNR and the spectral efficiency are increased with increasing the size of IRS and transmitted power for both of the strongest and weakest configuration. Also, it has been shown that the received power, SNR and the spectral efficiency are decreased with increasing the AP-IRS horizontal distance. Higher degree of bandwidth improves the received power and the spectral efficiency whereas it reduces the SNR. The performance comparison between the spectral efficiency of system with IRS and without IRS at different values of transmitted power and bandwidth is introduced. It is shown that, at bandwidth = 5 MHz, the system with IRS achieves nearly 3 times the spectral efficiency of the system without IRS and at bandwidth = 25 MHz, the system with IRS achieves nearly 14 times the spectral efficiency of the system without IRS. Also, at transmitted power = 0.5 Watt, the system with IRS achieves nearly 5 times the spectral efficiency of the system without IRS and at transmitted power = 2.5 Watt, the system with IRS achieves nearly 5.7 times the spectral efficiency of the system without IRS. So, The IRS can be used and aided in improvement of the spectral efficiency in 6G wireless communication. The evaluation of performance of IRS-aided wireless communication system in a multi-user scenario is discussed. The data rate, spectral and energy efficiency were evaluated by using four different methods (power method, uniform metal surface method, IRS with best pilot method and with the case of no IRS). It has been shown that the received power method and the best pilot method give the best data rate, spectral and energy efficiency at any value for each of the transmitted power, the bandwidth, the size of IRS and AP-IRS horizontal distance and consequently, enhance the performance of IRS- aided 6G wireless communication system.

A statistical analysis of causal factors influencing college student’s willingness to consume digital music

Determining the causal factors influencing college students’ willingness to consume digital music in China is crucial given the rapid integration of digital technology with the traditional music industry. Chengdu, as a rapidly developing city in China with a thriving youth culture and a significant presence of higher education institutions, provides an ideal setting to explore the factors influencing college students’ willingness to consume digital music. Using a mixed-method approach and a sample of 431 college students from various universities in Chengdu, this research examines the impact of perceived value, behavioral attitude, subjective norms, user participation, user stickiness, and psychological needs on digital music consumption intention. The empirical results show that these factors jointly affect consumption intention, with user stickiness and psychological needs serving as mediators. Specifically, perceived value, behavioral attitude, subjective norms, and user participation have a significant positive impact on consumption intention. These findings provide valuable insights for digital music platforms and the music industry to develop targeted marketing strategies and services tailored to the demands and behaviors of college students in Chengdu.

Fast recovery dynamics of GaSbBi-based SESAMs for high-fluence operation

Modelocked lasers operating in the 2–3 μm wavelength region are interesting for various spectroscopic applications. To this end, GaSb-based semiconductor saturable absorber mirrors (SESAMs) are developing fast as a practical technology for passive modelocking. Yet, such SESAMs suffer from either too high two-photon absorption or slow absorption recovery dynamics. This study introduces GaSbBi quantum wells (QWs) as a platform to ensure a larger material selection for engineering GaSb-based SESAMs with decreased two-photon absorption and ultrafast absorption recovery time. Three GaSbBi QW SESAM designs were fabricated to compare their performance against conventional GaInSb QW SESAMs. The first structure makes use of typical GaSb barriers and exhibits comparable characteristics to the conventional design, including a saturation fluence of 1.09 μJ cm−2, a modulation depth of 1.41%, and a fast interband recovery time of 6.03 ps. The second design incorporated AlAs0.08Sb0.92 barriers, achieving a reduced two-photon absorption, though at the cost of higher nonsaturable losses due to unintended Bi droplet formation during the growth of the AlAs0.08Sb0.92/GaSbBi QW heterostructure. Importantly, it maintained a fast interband recovery time (30 ps), overcoming the slow recovery dynamics exhibited by standard GaInSb QW SESAMs with AlAs0.08Sb0.92 barriers. The third design explored GaSbBi QWs with higher Bi content targeted for longer wavelength operation at 2.3 μm, which exhibited fast recovery times and good nonlinear reflectivity characteristics. However, the higher Bi content resulted in elevated nonsaturable losses. These results highlight the potential of GaSbBi QWs for short-wave infrared (SWIR) SESAMs, opening the path for further epitaxial optimization to enhance their performance.

Estimated ultimate recovery prediction of shale gas wells based on stacked integrated learning algorithm

Single‐Step Synthesis of a Heterometallic [Cu ₂ PdL ₄ ] ²⁺ Hybrid Metal–Organic Coordination Cage

Abstract Traditional methods of assembling low‐symmetry heterometallic cage architectures are limited to stepwise construction and combinations of inert and labile metal ions, affording complex, anisotropic cage structures by sacrificing synthetic ease. Herein, a heterometallic [Cu 2 PdL 4 ] 2+ lantern‐type cage has been assembled in a single self‐assembly step through the use of a heteroditopic ligand with two different metal‐binding groups. The resultant cage complex is a fusion of two common lantern‐type cage motifs—carboxylate‐based metal‐organic Cu 4 L 4 cages and pyridyl‐based Pd 2 L 4 coordination cages. Evidence for heterometallic cage formation in solution was provided by 1 H and diffusion‐ordered NMR spectroscopy and electrospray ionization mass spectrometry (ESIMS) data, whereas circular dichroism (CD) spectra confirmed the helical nature of the assembly. The heterometallic cage was then exploited in binding heterotopic guests. It is envisioned that the simple design strategy presented herein will ease the assembly of other structurally complex, low‐symmetry cage architectures.

Effects of jockey position and surfaces on horse movement asymmetry and horse-jockey synchronisation during trotting exercise

Racehorses and jockeys can incur injuries, not only during gallops, but also during routine trotting exercise to access gallop tracks or warm-up. Understanding how jockey position affects racehorse movement may influence safety, and this may vary across different surface conditions. This study used inertial sensing technology (XSens MTw sensors) and linear mixed models to quantify and determine the significance (p ≤ 0.05) of jockey riding position (‘rising’ versus ‘two-point seat’) and surface type (artificial, grass and tarmac) on: 1) time offsets between stance and flight phases; 2) horses’ vertical upper body movement asymmetry and 3) time lags (in % of stride time) between horse and jockey maximum and minimum vertical displacements. Six ex-racehorses were recruited on a convenience basis from the British Racing School and were ridden by one jockey. Surface type did not significantly influence timings between the stance and flight phases or horse asymmetry. Jockey riding position was linked to a 1.8% difference in stance phase offsets (p < 0.001) and 0.9% difference in flight phases (p = 0.015) for two-point seat versus rising trot. Jockey riding position also affected horse movement asymmetry at the poll across stance phases (weight bearing asymmetry, p = 0.005) and symmetry at the withers and sacrum across flight phases (push-off asymmetry, p < 0.001). In rising trot, the jockey reduced poll asymmetry around the seated stance phase, but increased withers and sacrum push-off asymmetries after the seated stance phase. Time-offsets between the horse and jockey minimum and maximum displacements around stance and flight phases, respectively, were also significantly affected by jockey riding position (all p < 0.001). As the jockey stood up in their stirrups at stance, in either the rising component of rising trot or in the two-point seat, their delay in following the horse’s movements increased by 2.8–4.5%, compared to when they were seated (p < 0.001). There was also an increased delay of the jockey by 0.6–0.8% around stance on tarmac compared to on the artificial surface (p ≤ 0.019). During flight phases, jockey displacement maximums were reached 5.5–7.0% and 9.3–11% after the horse following the seated stance in rising trot and during two-point seat, respectively, but jockey movements preceded horse movements around the post-standing flight phases by 4.9–7.3% in rising trot. In summary, jockey position had a greater impact on horse movement asymmetry and horse-jockey synchronisation than surface type. However, further work is required to relate study outcomes to injury risk.

Multifunctional altermagnet with large out-of-plane piezoelectric response in Janus V2AsBrO monolayer

Altermagnetism has emerged as a third fundamental category of collinear magnetism, characterized by spin splitting in symmetry-compensated collinear antiferromagnets, offering a promising platform for advances in spintronics and condensed matter physics. Here, based on first-principles calculations, we propose an altermagnetic semiconductor, the asymmetric Janus V2AsBrO monolayer, which exhibits a magnetic easy axis favoring the out-of-plane direction and a Néel temperature (TN) significantly exceeding room temperature. The system exhibits a strain-tunable piezovalley effect, generating valley polarization under uniaxial strain. Notably, hole doping under uniaxial strain generates a net magnetization (M) through a piezomagnetic mechanism. Additionally, the broken inversion symmetry endows the monolayer with a substantial out-of-plane piezoelectric coefficient d31 (2.19 pm/V), presenting broad prospects for the development and design of advanced piezoelectric devices. Our findings provide a promising candidate material for the advancement of 2D multifunctional devices in nanoelectronics, spintronics, valleytronics, and piezoelectrics.