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Identifying high-energy electronic states of NV− centers in diamond
The negatively charged nitrogen-vacancy center in diamond is a prototype photoluminescent point defect spin qubit with promising quantum technology applications, enabled by its efficient optical spin polarization and readout. Its low-lying electronic states and optical spin polarization cycle have been well characterized over decades, establishing it as a benchmark system for state-of-the-art computational methods in point defect research. While the optical cycle is well understood, a comprehensive energetic analysis of higher-lying states has received less attention until recently. In this joint experimental theoretical study, we identify and characterize five high-energy states beyond those involved in the optical cycle. Using transient absorption spectroscopy, we determine their transition energies and relative oscillator strengths. Additionally, we perform two independent numerical studies employing two state-of-the-art post-density functional theory methods to support the experimental findings and assign energy levels. These results enhance our understanding of the nitrogen-vacancy center's energy spectrum, providing a broader reference for benchmarking high-level first-principles methods.
The impact of physical exercise on university students’ life satisfaction: The chain mediation effects of general self-efficacy and health literacy
Objective This study aims to explore the impact of physical exercise on university students’ life satisfaction and analyses the chain mediation effect of general self-efficacy and health literacy, providing empirical reference and theoretical foundation for the comprehensive enhancement and optimization of students’ mental health. Method Based on data from the “China University Student Physical Activity and Health Tracking Survey” (CPAHLS-CS) 2024, the measurement scales used included the Physical Activity Rating Scale (PARS-3), the Satisfaction with Life Scale (SWLS), the General Self-Efficacy Scale (GSES), and the 9-item Short Form Health Literacy Scale (HLS-SF9). A total of 4575 valid samples were analyzed. Results A significant positive correlation was found between physical exercise and life satisfaction (r = 0.137, P < 0.01). The total effect of physical exercise on university students’ life satisfaction was significant, with an effect value of 0.045 (95%CI = [0.035, 0.054]). The chain mediation effect of general self-efficacy and health literacy in the relationship between physical exercise and life satisfaction was significant, with an effect value of 0.005 (95%CI = [0.004, 0.006]), accounting for 11.4% of the total effect. The direct effect of physical exercise on life satisfaction had a standardized regression coefficient of 0.001, which was not significant. Conclusion University students’ life satisfaction is closely related to physical exercise, general self-efficacy, and health literacy. General self-efficacy and health literacy play a full mediating role in the effect of physical exercise on life satisfaction.
Graphene enhanced resonant Raman spectroscopy of gallium nitride nanocrystals
The scattering of lattice excitations (phonons) with the photoexcited charge carriers is of a major concern in optoelectronic devices. Here, the resonant Raman scattering will be utilized to study an exciton–phonon interaction in GaN nanocrystals, further enhanced by the underlying graphene. Raman spectroscopy using various excitation energies shows how the exciton–phonon interaction behaves, unveiling the scattering strength. The origin of the interaction is in the condition of resonance, which is directly observed in the temperature resolved spectra. Most importantly, the underlying graphene strongly enhances the coupling of phonons and excitons. Consequently, an enhanced resonant Raman spectrum of GaN nanocrystals possessing clearly observable phonon overtones up to the fourth order has been obtained. It has been demonstrated that the responsible effect is the electron transfer between nanocrystals and the underlying graphene. The utilization of such an increased coupling effect can be beneficial for a study of the charge carrier scattering in semiconducting nanomaterials, analysis of their crystal quality, improvement of sensor sensitivity, and in the subsequent development of new-generation optoelectronic devices.
Development of an H&E on-block staining technique for collagen detection in cryo-fluorescence tomography imaging of frozen breast tissue samples
Hematoxylin and eosin (H&E) staining is widely considered to be the gold-standard diagnostic tool for histopathology evaluation. However, the fatty nature of some tissue types, such as breast tissue, presents challenges with cryo-sectioning, often resulting in artifacts that can make histopathologic interpretation and correlation with other imaging modalities virtually impossible. We present an optimized on-block H&E staining technique that improves contrast for identifying collagenous stroma during cryo-fluorescence tomography (CFT) sectioning. In this prospective study, we embedded four breast specimens with confirmed ligaments from a bilateral mastopexy in an optimal cutting temperature block. Two of the samples were processed on a CFT imager and stained with our on-block staining protocol. In this protocol, hematoxylin was applied to the block-face before being washed with deionized water. Eosin was then applied and washed with 95% ethanol. We then applied mounting medium and acquired images with a stereo-dissecting microscope and camera. Prior to staining, GFP fluorescence and white-light images were acquired with the CFT system to serve as a validation metric. The other two samples were sectioned on a standard cryostat and stained according to gold-standard H&E protocol. The resulting microscope slides were imaged with a digital slide scanner and viewed with Leica Imagescope software. An experienced pathologist evaluated both sets of images for qualitative comparisons. Pathologist evaluation confirmed that striations from on-block staining were qualitatively comparable with collagen tracks identified in gold-standard histology images. Furthermore, GFP images captured collagen autofluorescence, which aligned with the same structures identified by our on-block staining protocol. Our on-block staining technique shows comparable visualization of collagenous structures at the mesoscopic level for fresh breast tissue samples. This technique improves tissue contrast and region of interest selection for histology during CFT imaging for analysis of the stromal architecture of the breast.
Phase zonal reconstruction via differential metasurface
Phase reconstruction has a wide range of application in the field of optical measurement. A phase zonal reconstruction method using differential metasurface is proposed, where bias images in horizontal and vertical directions are captured to extract phase gradients for zonal reconstruction. This approach enables simultaneous edge detection and phase reconstruction while leveraging the unique advantages of metasurface, including their compactness, high customization potential, and ease of integration into miniaturized optical systems. Furthermore, the phase zonal reconstruction approach effectively enhances the resolution and quality of phase information measurement. Both theoretical and experimental results demonstrate that this method delivers exceptional performance, offering a promising solution for optical measurements that require efficient integration into existing systems. It also paves the way for advanced detection in manufacturing, quality control, and materials science.
Mitochondrial genomic alterations in cholangiocarcinoma cell lines
Cholangiocarcinoma (CCA) is a diverse collection of malignant tumors that originate in the bile ducts. Mitochondria, the energy converters in eukaryotic cells, contain circular mitochondrial DNA (mtDNA) which has a greater mutation rate than nuclear DNA. Heteroplasmic variations in mtDNA may suggest an increased risk of cancer-related mortality, serving as a potential prognostic marker. In this study, we investigated the mtDNA variations of five CCA cell lines, including KKU-023, KKU-055, KKU-100, KKU213A, and KKU-452 and compared them to the non-tumor cholangiocyte MMNK-1 cell line. We used Oxford Nanopore Technologies (ONT), a long-read sequencing technology capable of synthesizing the whole mitochondrial genome, which facilitates enhanced identification of complicated rearrangements in mitogenomics. The analysis revealed a high frequency of SNVs and INDELs, particularly in the D-loop, MT-RNR2 , MT-CO1 , MT-ND4 , and MT-ND5 genes. Significant mutations were detected in all CCA cell lines, with particularly notable non-synonymous SNVs such as m.8462T > C in KKU-023, m.9493G > A in KKU-055, m.9172C > A in KKU-100, m.15024G > C in KKU-213A, m.12994G > A in KKU-452, and m.13406G > A in MMNK-1, which demonstrated high pathogenicity scores. The presence of these mutations suggests the potential for mitochondrial dysfunction and CCA progression. Analysis of mtDNA structural variants (SV) revealed significant variability among the cell lines. We identified 208 SVs in KKU-023, 185 SVs in KKU-055, 231 SVs in KKU-100, 69 SVs in KKU-213A, 172 SVs in KKU-452, and 217 SVs in MMNK-1. These SVs included deletions, duplications, and inversions, with the highest variability observed in KKU-100 and the lowest in KKU-213A. Our results underscore the diverse mtDNA mutation landscape in CCA cell lines, highlighting the potential impact of these mutations on mitochondrial function and CCA cell line progression. Future research is required to investigate the functional impacts of these variants, their interactions with nuclear DNA in CCA, and their potential as targets for therapeutic intervention.
Thicker lubricant layer enhances the droplet mobility on lubricant-infused smooth surfaces
Droplets are highly mobile on lubricant-infused surfaces when droplet−lubricant phases are immiscible, and lubricant layer is stable. Recent studies have shown that the high droplet mobility is due to the absence of three-phase contact line friction by oleoplaning of the droplets on the lubricant layer. In this state, dynamic friction arises primarily from viscous dissipation in the lubricant around the droplet. Classical Landau–Levich–Derjaguin (LLD) law suggests that the friction force is proportional to the two-thirds power of the capillary number, and the lubricant thickness effect is not included. Here, we discovered that increased lubricant thickness enhances the droplet's mobility on lubricant-infused surfaces. This finding is unexpected, as a thicker lubricant layer would typically increase the potential volume for viscous dissipation. We formed stable lubricant layers of varying thicknesses ranging from tens to hundreds of micrometers on a “nanometrically smooth” base layer to remove the influence of surface texture. The droplet friction force on the different lubricant thickness surfaces is measured using the cantilever method. While all surfaces follow the LLD law, the friction force significantly decreases with increasing the lubricant thicknesses. The possible reason is the decrement of the energy dissipation at the lubricant ridge with the thickness. We propose a modified friction model incorporating the thickness dependence with the classical law, offering deeper insight into droplet friction dynamics on the lubricant-infused surfaces. In practical terms, reducing droplet friction enhances transport efficiency, contributing to advancements in fluidic systems and liquid-repellent applications.
Aggregating soft labels from crowd annotations improves uncertainty estimation under distribution shift
Selecting an effective training signal for machine learning tasks is difficult: expert annotations are expensive, and crowd-sourced annotations may not be reliable. Recent work has demonstrated that learning from a distribution over labels acquired from crowd annotations can be effective both for performance and uncertainty estimation. However, this has mainly been studied using a limited set of soft-labeling methods in an in-domain setting. Additionally, no one method has been shown to consistently perform well across tasks, making it difficult to know a priori which to choose. To fill these gaps, this paper provides the first large-scale empirical study on learning from crowd labels in the out-of-domain setting, systematically analyzing 8 soft-labeling methods on 4 language and vision tasks. Additionally, we propose to aggregate soft-labels via a simple average in order to achieve consistent performance across tasks. We demonstrate that this yields classifiers with improved predictive uncertainty estimation in most settings while maintaining consistent raw performance compared to learning from individual soft-labeling methods or taking a majority vote of the annotations. We additionally highlight that in regimes with abundant or minimal training data, the selection of soft labeling method is less important, while for highly subjective labels and moderate amounts of training data, aggregation yields significant improvements in uncertainty estimation over individual methods. Code can be found at https://github.com/copenlu/aggregating-crowd-annotations-ood
Enhanced electrocaloric effect in relaxor ferroelectric polymers through hot press processing
Electrocaloric relaxor ferroelectric polymers have been considered as dominant polymer materials for refrigeration applications. However, the magnitude of the electrocaloric effect remains relatively small, especially in the low electric field regime. Here, it is reported that using hot pressing at 40 MPa under a holding temperature of 100 °C and a holding time of 10 min as a postprocessing method, an improved electrocaloric temperature change of 4.7 K is achieved under a low electric field of 50 MV m−1, which exceeds pristine polymers by over 50%. The enhanced electrocaloric response is attributed to the stabilization of all-trans conformation caused by hot pressing, which facilitates the ease of electric field-induced disorder-to-order phase transition.
Prevalence and contributing factors of executive cognitive dysfunction symptoms in university students
The importance of executive cognition should not be overlooked in the private and academic lives of university students. It includes important constituents of the human mind, including but not limited to, organizing, directing, solving problems, and controlling oneself and these processes are central to surviving the rigors of higher education. Good executive function enables the students to perform complex tasks, such as fighting deadlines, understanding the course structure, and participating in many other activities. Further, it assists in arriving at resolutions and managing tensions as one transitions into adulthood, both of which are critical. In other words, executive cognitive deficits are correlated with problems in academic progression, time management, and overall adjustment to the possible social and emotional stressors of university experience. This cross-sectional study, involving 1,204 students, used the validated Arabic version of the Dysexecutive Questionnaire (DEX) to measure executive cognitive function, along with demographic and lifestyle data. The results showed significant associations between executive cognition dysfunction and certain lifestyle factors common among generation Z, such as hours spent on smartphones or electronic devices (p < 0.0001), social media platform use (p = 0.0484), weekly fast food consumption (p < 0.0001), and daily hours on social media (p < 0.0001). Additional factors included weak family relationships (p = 0.0018), gender (p = 0.029), family income (p = 0.0164), urban residence (p = 0.0176), prior mental health consultations (p < 0.0001), and parental separation (p < 0.0375). Conversely, regular sports participation and exercise were linked to lower dysfunction scores (p = 0.0327), suggesting a protective effect. These findings underscore the impact of lifestyle and personal circumstances on cognitive functioning, highlighting the need for balanced technology use, healthy diets, strong family and social networks, and physical activity. Early psychological support for at-risk students may further enhance cognitive resilience and overall well-being.
Unraveling weak interfacial coupling in NaCl/WSe2 heterostructures
Resolving and controlling interfacial coupling between transition metal dichalcogenides and dielectric layer in heterostructures are of great importance in various physical phenomena. Here, we established the monolayer sodium chloride (NaCl) epitaxially grown on the monolayer tungsten selenide (WSe2) underlayer and demonstrated weak covalent-like quasi-bonding in the heterostructure. By using scanning tunneling microscopy, we observed the template effect of WSe2 lattices on NaCl epitaxy, with the edge of NaCl islands extending along three highly symmetric orientations of WSe2. NaCl islands also exhibited lower apparent height compared to WSe2 monolayers at various biases, which could be attributed to the almost unaffected electrostatic screening of NaCl within the weak interfacial coupling regime. Thermal stability experiments showed that the coupling strength of the NaCl/WSe2 interface is stronger than that of NaCl on Au(111) due to the extra quasi-bonding. Density functional theory calculations further verified the experimental observations and unveiled that the fundamental nature of interfacial coupling could arise from weak covalent-like quasi-bonding between Na+ ions and Se atoms accompanied by electron accumulation.
What, when, and how food and beverage are advertised on Ghanian television
Food marketing has increased volume, precision, and reach to influence viewers’ food attitudes, beliefs, and eating behaviors. What and how much people eat has implications for health. While many countries regulate food advertising to protect consumers and encourage healthy eating, Ghana has none. Understanding the content and framing of food and beverage advertisements can inform the development of effective policies and practices that encourage healthier diets. This content analysis examines the foods and beverages advertised, their timing, and marketing techniques on Ghanaian television. From February to May 2020, 486 hours of advertisements were recorded. Advertisements with ≥1 actors were coded for food type, actor characteristics (i.e., body size, gender, age, race), and marketing techniques (i.e., promotional characters, premium offers, goal frames). A total of 607 advertisements with 2,043 actors were analyzed. Two-thirds (66.8%) promoted foods categorized as unhealthy. Sugar-sweetened beverages (22.6%) were most frequent, followed by grains high in sugar and low in fiber (13.2%), recipe additions (13.1%), and supplements (10.2%). Half (52.9%) of advertisements used persuasive marketing strategies. Most actors were classified as underweight (72.1% v. 20.5% normal weight, 7.4% overweight/obese) with a balanced gender distribution (49.1% female). Most advertisements aired during evenings (37.7%) and weekdays (69.5%). Morning advertisements promoted more healthy foods, whereas evening and night advertisements promoted more unhealthy foods. Gain goal frames were most common for healthy foods (p < 0.001), hedonic frames for unhealthy foods (p < 0.001), and normative frames showed no difference (p = 0.54). Underweight actors frequently appeared in unhealthy advertisements (68.3% v. 56.0% normal weight, 59.0% overweight/obese), whereas normal-weight (44.0%) and overweight/obese actors (41.0% v. 31.7% underweight) appeared in healthy advertisements. Persuasive marketing strategies were frequently advertised with unhealthy foods (59.9%) and overweight/obese (54.9%) and male actors (53.6%). This study highlights the need for effective policies to regulate food marketing, promoting healthier diets and realistic body expectations.
Microwave dynamics of gated Al/InAs superconducting nanowires
Several experiments have recently reported on gate-tunable superconducting properties in metallic devices, holding promise for the realization of cryogenic switches, tunable resonators, and superconducting logic. In particular, the suppression of the critical current as a function of the gate voltage has been widely investigated. However, time domain studies are discussed only in a few cases. In this paper, we present a microwave characterization of a gate-controlled Al-capped InAs nanowire embedded in a λ/4 coplanar waveguide resonator. We observe a shift in the resonator frequency and an increase in its internal losses as a function of the gate voltage, which we relate to a change in the imaginary and real components of the nanowire impedance, respectively. We demonstrate that these changes are described by the Mattis–Bardeen model with an effective temperature. We further study the resonator response to fast-varying gate signals and measure characteristic response times of the order of 40 ns, both in time domain and parametric modulation experiments. Our study elucidates the impact of the gate on the complex impedance of the nanowire in the superconducting state, as well as its dynamic performance, providing a foundation for the design of gate-controlled superconducting devices.
Where octagonal geometry meets chaos: A new S-Box for advanced cryptographic systems
Substitution Box (S-Box) has had been a cardinal component of various cryptographic systems. In this paper, we introduce a novel S-Box design that merges octagonal geometry with chaotic dynamics to enhance the security effects of the cryptographic systems. In particular, the proposed method leverages the geometric properties of octagons and the unpredictability of chaotic maps to construct a novel S-Box with improved security features. The mathematical construct octagon carries out the necessary operation of confusion in the proposed S-Box. The centres of these octagons are hypothetically created within the confines of the 16×16 matrix of numbers. Further, these octagons have different radii, locations, and the amounts with which the numbers lying on their boundaries have to be circularly shifted clockwise or anti-clockwise to create the confusion effects. In case, a portion of octagon goes past the edges of the matrix, the numbers lying on its boundary have been wrapped out. This process has been repeated numerous times to come up with a reliable and a secured S-Box. The comprehensive security analyses validate that the proposed S-Box is furnished with nice security effects and has the requisite resilience to defy the varied cryptanalytic threats. The results of non-linearity and differential probability are 105.625 and 0.0391 respectively which signals towards the inherent robustness of the suggested S-Box.
A unified approach for truncated and extended adsorbed liquid films in evaporating menisci
The morphology of evaporating menisci near the three-phase contact line region—whether characterized by a truncated adsorbed liquid film or an extended adsorbed liquid film—has been the subject of long-standing debate. In this Letter, we present a unified mesoscopic approach for predicting both the morphological evolution and heat transfer characteristics of evaporating menisci. This methodology provides a comprehensive framework capable of simultaneously characterizing the truncated-adsorbed liquid film regime, the extended-adsorbed liquid film regime, and their transitional behavior. We explain the stability mechanism and evaporation heat transfer characteristics of nanoscale liquid films, as well as the self-regulation mechanism governing the evaporating meniscus between the extended-adsorbed film regime and the truncated-adsorbed film regime. This unified framework provides a useful tool for investigating the nanoscale evaporation heat transfer characteristics and mechanisms in liquid–vapor phase change processes.
From eyes’ microtremors to critical flicker fusion
The critical flicker fusion threshold (CFFT) is the frequency at which a flickering light source becomes indistinguishable from continuous light. The CFFT is an important biomarker of health conditions, such as Alzheimer’s disease and epilepsy, and is affected by factors as diverse as fatigue, drug consumption, and oxygen pressure, which make CFFT individual- and context-specific. Other causal factors beyond such biophysical processes are still to be uncovered. We investigate the connection between CFFT and specific eye-movements, called microtremors, which are small oscillatory gaze movements during fixation periods. We present evidence that individual differences in CFFT can be accounted by microtremors, and design an experiment, using a high-frequency monitor and recording the participant’s eye-movements with an eye-tracker device, which enables to measure the range of frequencies of a specific individual’s CFFT. Additionally, we introduce a classifier that can predict if the CFFT of specific participant lies in the range of high or low frequencies, based on the corresponding range of frequencies of eyes’ microtremors. Our results show an accuracy of 85% for a frequency threshold of 60 Hz and 88% for a threshold of 120 Hz.
Hydrophilic direct bonding of (100) diamond and deposited SiO2 substrates
Diamond has emerged as a leading material for solid-state spin quantum systems and extreme environment electronics. However, a major limitation is that most diamond devices and structures are fabricated using bulk diamond plates. The absence of a suitable diamond-on-insulator (DOI) substrate hinders the advanced nanofabrication of diamond quantum and electronic devices, posing a significant roadblock to large-scale, on-chip diamond quantum photonics and electronics systems. In this work, we demonstrate the direct bonding of (100) single-crystal diamond plates to PECVD-grown SiO2/Si substrates at low temperatures and atmospheric conditions. The surfaces of the SiO2 and diamond plates are then activated using oxygen plasma and Piranha solution, respectively. Bonding occurs when the substrates are brought into contact with water in between and annealed at 200 °C under atmospheric conditions, resulting in a DOI substrate. We systematically studied the influence of Piranha solution treatment time and diamond surface roughness on the shear strength of the bonded substrate, devising an optimal bonding process that achieves a high yield rate of 90% and a maximum shear strength of 9.6 MPa. X-ray photoelectron spectroscopy was used for quantitative analysis of the surface chemicals at the bonding interface. It appears that the amount of –OH bindings increases with the initial roughness of the diamond, facilitating the strong bonding with SiO2. This direct bonding method will pave the way for scalable manufacturing of diamond nanophotonic devices and enable large-scale integration of diamond quantum and electronic systems.
Black soil layer thickness prediction and soil erosion risk assessment in a small watershed in Northeast China
Black soil has good properties and high fertility. Understanding the spatial distribution of black soil layer thickness is of great significance in promoting regional agricultural development, ecological environmental protection, and soil erosion control. However, traditional soil investigation methods often fail to provide detailed soil thickness information. This study focuses on a small watershed in Northeast China’s black soil region. By integrating topographical parameters and vegetation-climate indicators, random forest and kriging methods (classical bayesian, ordinary, and simple) were used to estimate the spatial distribution of thickness of black soil layer. An integrated evaluation framework was developed by combining RUSLE-derived erosion estimates with black soil layer thickness, systematically incorporating both external erosive forces and inherent soil erosion resistance attributes. The results show that the random forest model outperformed the kriging models, with smaller RMSE (34.05 cm) and larger R² (0.57), especially when handling nonlinear, high-dimensional data. The predicted thickness of the black soil layer ranged from 16.2 cm to 107 cm, with a mean of 48.31 cm, closely matching the measured value of 48 cm. Elevation (EL) was found to be the most significant factor affecting the thickness of black soil layer. Soil erosion risk assessment revealed that areas with no risk and low risk accounted for 21.91% and 62.21%, respectively, while medium and high-risk areas made up 15.87% and 0.01%. No-risk areas were soil accumulation zones, while low-risk areas were mainly sloped farmland, where measures like terracing, adjusting crop ridge directions, and planting pedunculated vegetation were recommended. Medium- and high-risk areas should be addressed by returning farmland to forests and implementing engineering practices. This study offers a reference for thickness of black soil layer estimation and provides valuable insights for soil erosion risk management.
Investigation on high-order planar Hall effect in trigonal PtBi2
The trigonal PtBi2 (t-PtBi2) as a Weyl semimetal possessing triply degenerate points in its electronic bands near the Fermi level endows it with rich electronic properties. Previous studies have already measured the planar Hall effect (PHE) and in-plane anisotropic magnetoresistance (AMR) of t-PtBi2. We noticed that their experimental results exhibited high-order features in both the PHE and AMR, yet these features were not systematically investigated. In our work, we conducted more systematic measurements and analyses of the PHE and AMR in t-PtBi2. Both PHE and AMR show high-order features under low temperatures and strong magnetic fields, and these features share a similar temperature and magnetic field dependence with the “turn-on” behavior of resistance and temperature curves, indicating a common physical origin for them. We further summarize the critical conditions for the emergence of high-order PHE in t-PtBi2, which will help to understand the origin of high-order features. In addition, we performed computational simulations on the AMR of t-PtBi2, and the results were consistent with the experiments, indicating the high-order features are the result of the combined contribution of the Fermi surface anisotropy and the scaling behavior of magnetoresistance. Our findings will contribute to a deeper understanding of the origins of high-order features in non-magnetic topological materials.