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A long gas cell, filled with noble gas, is typically positioned between the undulator and the first mirror in the free-electron laser (FEL) beamline to attenuate the laser power as required by the end-stations. In addition to attenuation, the gas cell also serves important functions in various applications, such as spectrometer calibration, resolving power evaluation during beamline commissioning, and filtering of third harmonic in FEL operations. These functions of the gas cell have been successfully tested and implemented at the Dalian Coherent Light Source, a vacuum ultraviolet FEL facility located in Dalian, China. The resolving power of higher than 5000 has been obtained, and accurate calibration has been completed using the gas cell. During operation, the third harmonic of the FEL was attenuated by approximately one order of magnitude with almost the same power of the fundamental. This greatly improved the signal-to-noise ratio at the end-stations. [ABSTRACT FROM AUTHOR]

An underwater shooting method with a novel barrel structure featuring spiral grooves is designed by opening multiple spiral grooves on the gun barrel's tail inner wall, and the combustion-gas flows are guided to create multiple gas jets that are sprayed into the barrel to form a gas curtain for water drainage. A three-dimensional unsteady multiphase mathematical model was created, and the correctness of the numerical model established was verified by comparing it with the experimental results of underwater gun gas curtain drainage visualization. On this basis, the influence of different spiral grooves on the evolution process of gas jet and liquid and the drainage effects were simulated. The results indicate that the phase change happens in close proximity to the gas–liquid boundary; nonetheless, the volume percentage of vapor generated by phase change during gas–liquid interaction is less than 1%. The more grooves there are, the greater the maximum pressure at each moment inside the fully filled circular tube; the temperature at the front end of the circular tube becomes higher. When the number of grooves is increased from 4 to 6, the drainage completion time is shortened by 29.7%, the amount of gas in the circular barrel increased by 5.2%, and the drainage rate is significantly increased. However, as the amount of grooves increased from 6 to 8, the gas volume fraction and drainage rate in the tube only increased slightly. On the contrary, it takes a little more time to complete the drainage. [ABSTRACT FROM AUTHOR]

Marriage of convenience is a unique phenomenon in China where a gay man and a lesbian get married to fulfill social expectations while retaining their homosexual identities. Men who have sex with men (MSM) are at increased risk of HIV infection and intimate partner violence (IPV) following HIV disclosure. A sample of 232 HIV‐infected MSM in the marriage of convenience was recruited online and completed questionnaires about experiences of IPV, HIV disclosure, and their sociodemographic, clinical, and psychosocial characteristics. Our results showed that over half (57.3%) of HIV‐infected MSM had disclosed their HIV status to their lesbian spouses. Bisexual men, having children with their lesbian spouse, HIV diagnosis time >24 months, having a current fixed gay partner, having disclosed HIV to their current fixed gay partners, higher levels of social support, lower levels of self‐stigma related to HIV infection, no depression, and no suicidal ideation were all independently associated with an increased likelihood of disclosing to lesbian spouses. Approximately 61.6% of participants experienced at least one type of IPV from either a gay partner, a lesbian spouse, or both in the past 12 months. HIV disclosure to lesbian spouses was associated with an increased risk of IPV. Our findings reveal the high prevalence of IPV among HIV‐infected MSM in the marriage of convenience and its association with HIV disclosure, which warrants policy, clinical, and research efforts to design targeted and comprehensive interventions to improve HIV disclosure while preventing IPV among this population. [ABSTRACT FROM AUTHOR]

BACKGROUND: As a critical m6A RNA methylation regulator, HNRNPC has been revealed to serve as potential biomarkers in various human cancers. The specific expression and significance of HNRNPC in colorectal cancer remain unknown. OBJECTIVE: This study aimed to confirm HNRNPC expression level and evaluate its function in colorectal cancer progression. METHODS: 101 paired tissue samples were collected from colorectal cancer patients. HNRNPC levels in colorectal cancer were detected using PCR. CCK8 and transwell assays were conducted to estimate the effect of HNRNPC on cell growth and metastasis with the regulation of HNRNPC by cell transfection. RESULTS: Upregulated HNRNPC was observed in colorectal cancer compared with normal tissues and cells. The higher HNRNPC levels in tumor tissues were associated with the advanced TNM stage and positive lymph node metastasis. Meanwhile, HNRNPC upregulation could indicate adverse outcomes of colorectal cancer patients. In vitro, the knockdown of HNRNPC significantly suppressed the proliferation, migration, and invasion of colorectal cancer cells. CONCLUSIONS: Upregulated HNRNPC served as a biomarker for the prognosis and development of colorectal cancer, which provides a novel therapeutic target for colorectal cancer. [ABSTRACT FROM AUTHOR]

Background: We previously demonstrated the validity of a regression model that included ethnicity as a novel predictor for predicting normative brain volumes in old age. The model was optimized using brain volumes measured with a standard tool FreeSurfer. Objective: Here we further verified the prediction model using newly estimated brain volumes from Neuro I, a quantitative brain analysis system developed for Korean populations. Methods: Lobar and subcortical volumes were estimated from MRI images of 1,629 normal Korean and 786 Caucasian subjects (age range 59–89) and were predicted in linear regression from ethnicity, age, sex, intracranial volume, magnetic field strength, and scanner manufacturers. Results: In the regression model predicting the new volumes, ethnicity was again a substantial predictor in most regions. Additionally, the model-based z-scores of regions were calculated for 428 AD patients and the matched controls, and then employed for diagnostic classification. When the AD classifier adopted the z-scores adjusted for ethnicity, the diagnostic accuracy has noticeably improved (AUC = 0.85, ΔAUC = + 0.04, D = 4.10, p < 0.001). Conclusions: Our results suggest that the prediction model remains robust across different measurement tool, and ethnicity significantly contributes to the establishment of norms for brain volumes and the development of a diagnostic system for neurodegenerative diseases. [ABSTRACT FROM AUTHOR]

The in-plant use of recycled aggregate concrete derived from precast rejects (termed PRAC herein) can promote a circular economy in the precast industry. However, the environmental implications associated with this practice remain poorly understood. A refined life cycle assessment (LCA) model was therefore developed to highlight the environmental benefits of using PRAC compared to natural aggregate concrete and conventional recycled aggregate concrete. Some key factors influencing PRAC's environmental performance were also examined. The results indicate that PRAC exhibits around 15% lower energy consumption and carbon dioxide emissions compared to other recycled materials. This reduction is attributed to the favourable quality of PRAC and the elimination of long-distance transport. However, emissions allocation and raw material prices play significant roles in determining the overall environmental impact of PRAC. The equivalent mortar volume mixing method is best suited for PRAC production, as it saves energy, reduces emissions, and maintains similar mechanical properties. Nevertheless, the high-temperature curing, which is often necessary in a precast factory setting, can be energy-intensive and thus diminishes the eco-friendliness of PRAC. Overall, the findings support the use of precast rework as recycled aggregate for cleaner production in the precast industry. [ABSTRACT FROM AUTHOR]

This paper presents a computational study on the flexural fracture behaviors of steel fiber reinforced concrete (SFRC). The focus is on investigating the impacts of various factors on SFRC, utilizing a discrete-continuum coupled finite element method. This method explicitly models each material phase, including coarse aggregates, mortar paste, steel fibers and interfacial transition zones (ITZs), allowing precise tracking of mesoscale cracking during bending. The simulation method is developed, calibrated and validated before conducting a parametric investigation. Critical factors considered include the spatial positioning of coarse aggregates and steel fibers, fiber content, length and diameter, and the bonding property of fiber-mortar ITZs. Results indicate that steel fibers modify crack development in notched beams, causing greater distortion in the primary crack. Increasing fiber content from 0 to 2% enhances flexural tensile strength but introduces more variability. Longer fibers initially increase strength, then decrease, while thicker fibers consistently reduce strength. Improving the bond between fibers and mortar does not substantially increase the load-bearing capacity of the beam. In conclusion, this study shows how the established approach enhances understanding of the mechanical responses of SFRC under flexural-fracture loading. [ABSTRACT FROM AUTHOR]

The 13C isotope composition (δ13C) of leaf dry matter is a useful tool for physiological and ecological studies. However, how post-photosynthetic fractionation associated with respiration and carbon export influences δ13C remains uncertain. We investigated the effects of post-photosynthetic fractionation on δ13C of mature leaves of Cleistogenes squarrosa , a perennial C4 grass, in controlled experiments with different levels of vapour pressure deficit and nitrogen supply. With increasing leaf age class, the 12C/13C fractionation of leaf organic matter relative to the δ13C of atmosphere CO2 (ΔDM) increased while that of cellulose (Δcel) was almost constant. The divergence between ΔDM and Δcel increased with leaf age class, with a maximum value of 1.6‰, indicating the accumulation of post-photosynthetic fractionation. Applying a new mass balance model that accounts for respiration and export of photosynthates, we found an apparent 12C/13C fractionation associated with carbon export of –0.5‰ to –1.0‰. Different ΔDM among leaves, pseudostems, daughter tillers, and roots indicate that post-photosynthetic fractionation happens at the whole-plant level. Compared with ΔDM of old leaves, ΔDM of young leaves and Δcel are more reliable proxies for predicting physiological parameters due to the lower sensitivity to post-photosynthetic fractionation and the similar sensitivity in responses to environmental changes. [ABSTRACT FROM AUTHOR]

Background: Intimate Partner Violence (IPV) is prevalent among HIV-infected men who have sex with men (MSM), with well-established risk factors and adverse outcomes. However, there is a lack of comprehensive investigation of both upstream risk factors and downstream adverse outcomes among HIV-infected MSM in a Chinese context. This study aimed to examine IPV and its associations among a Chinese sample of HIV-infected MSM. Methods: A cross-sectional study was conducted among 294 HIV-infected MSM in Jinan City from June to December 2020. All data were collected through an online questionnaire, which included IPV, sexual risk behavior, antiretroviral therapy (ART) adherence, depression, anxiety, and suicidal ideation. Chi-square tests and multivariate logistic regressions were performed to examine risk factors and adverse outcomes of IPV. Results: Of the 294 HIV-infected MSM, 71.1% experienced any IPV, including control (37.1%), threat of public identity (30.6%), emotional violence (25.2%), security threat (18.4%), and physical violence (13.9%). The prevalence of sexual risk behavior, good ART adherence, depression, anxiety, and suicidal ideation was 55.1%, 53.4%, 48.3%, 32.3%, and 65.0%, respectively. Abuse of methamphetamine (METH) (aOR:2.79; 95%CI:1.43 ~ 5.45), capsule 0 or stimulating liquid (aOR:2.68; 95%CI:1.31 ~ 5.47), Magu (aOR:3.16; 95%CI:1.51 ~ 6.60), and other new drugs (aOR:2.87; 95%CI:1.52 ~ 5.43), disclosing HIV infection to partners (aOR:2.03; 95%CI:1.10 ~ 3.78), and gay sexual orientation (aOR = 3.32; 95%CI: 1.82 ~ 6.05) were significantly correlated with the experience of IPV. In addition, IPV was significantly associated with sexual risk behavior (aOR = 2.02; 95%CI:1.16 ~ 3.53), ART adherence (aOR = 2.63; 95%CI:1.46 ~ 4.74), depression (aOR = 3.83; 95%CI:2.09 ~ 7.02), anxiety (aOR = 2.27; 95%CI:1.19 ~ 4.35), and suicidal ideation (aOR = 3.78; 95%CI:2.11 ~ 6.80). Conclusions: IPV is prevalent among HIV-infected MSM and is associated with poor behavioral and mental health, highlighting more efforts are needed to address this issue. The finding that new drug abuse, HIV disclosure, and gay sexual orientation are associated with increased risk of IPV provides essential insights for the development of comprehensive and targeted IPV prevention and intervention programs in the future. [ABSTRACT FROM AUTHOR]

Proton-conducting electrolyte materials are essential for the development of high-performance protonic ceramic fuel cells (PCFCs). This work investigates the proton conduction property of a γ-MnO 2 based heterostructure electrolyte composing with gadolinium-doped ceria (GDC). The electrochemical proton injection into the γ-MnO 2 -GDC composite electrolyte is thoroughly studied using various characterization techniques, including infrared (IR) and Raman spectroscopy, and EIS with distribution of relaxation times (DRT) analysis. The optimized γ-MnO 2 -GDC heterostructure composite exhibits an ionic conductivity of 0.2 S cm−1 at 520 °C during fuel cell operation and proton conduction dominating the ion conduction is confirmed by proton filtering cell. Excellent fuel cell performance with a maximum power density of 896 mW cm−2 at 520 °C has been demonstrated. The work highlights the potential of the γ-MnO 2 based heterostructure composite as a proton-conducting electrolyte material for advanced PCFCs, offering new prospects for the development of cost-effective and efficient energy conversion technologies. • γ-MnO 2 was first utilized in fuel cell electrolyte. • The proton conduction mechanism in γ-MnO 2 has been verified. • γ-MnO 2 -GDC heterostructure electrolyte demonstrated good fuel cell performance. • Bulk and interface in heterostructure electrolyte improved ion transport. [ABSTRACT FROM AUTHOR]

With the implementation of the rural revitalization strategy, the scale of entrepreneurial groups returning home in China has gradually grown and has become the main force to promote the development of rural industries. In this wave of returning home to start businesses, facing six different modes of rural industrial integration, the development of rural industrial integration in China is facing the imbalance between supply and demand of talents. In terms of supply, labor skills, educational background and entrepreneurial employment motivation of returning entrepreneurs are obviously different. In terms of demand, there are also differences in the quantity, scale and skill structure of industrial talents in different rural industrial integration modes. Analyzing the gap between supply and demand of industrial talents and their differences, and introducing and cultivating all kinds of urgently needed talents in a targeted manner can put forward relevant policy suggestions for the integrated development of rural industries in China. [ABSTRACT FROM AUTHOR]

Introduction: Laparoscopic radical prostatectomy (LRP) has become a common option for the treatment of prostate cancer. The aim of our study was to examine whether LRP performed within 12 weeks of transurethral resection of the prostate (TURP) is associated with surgical difficulty or outcomes. Material and methods: A single-institutional retrospective analysis was performed on patients who underwent LRP for incidental prostate cancer after TURP between July 2009 and December 2017. The interval between TURP and LRP was determined and patients with intervals of = 12 weeks were compared to those with intervals of > 12 weeks. Patient characteristics, perioperative, pathological, and postoperative functional outcomes were analyzed to determine statistically significant differences between the 2 groups. Multivariable analyses were performed to determine whether the interval between TURP and LRP was a significant independent predictor of these outcomes. Results: A total of 56 incidental prostate cancer patients detected by TURP were included in this study. No significant differences were detected in estimated blood loss, operative duration, postoperative length of stay, and rate of positive margin, Gleason score upgrading, major complications, incontinence and prostate-specific antigen (PSA) recurrence in patients with a TURP to LRP interval above and below 12 weeks. The TURP to LRP interval was not an independent predictor of outcomes during or after LRP. Conclusions: Our results showed that performing LRP within 12 weeks after TURP does not adversely influence surgical difficulty or outcomes. [ABSTRACT FROM AUTHOR]

Background: Intimate Partner Violence (IPV) is prevalent among HIV-infected men who have sex with men (MSM), with well-established risk factors and adverse outcomes. However, there is a lack of comprehensive investigation of both upstream risk factors and downstream adverse outcomes among HIV-infected MSM in a Chinese context. This study aimed to examine IPV and its associations among a Chinese sample of HIV-infected MSM. Methods: A cross-sectional study was conducted among 294 HIV-infected MSM in Jinan City from June to December 2020. All data were collected through an online questionnaire, which included IPV, sexual risk behavior, antiretroviral therapy (ART) adherence, depression, anxiety, and suicidal ideation. Chi-square tests and multivariate logistic regressions were performed to examine risk factors and adverse outcomes of IPV. Results: Of the 294 HIV-infected MSM, 71.1% experienced any IPV, including control (37.1%), threat of public identity (30.6%), emotional violence (25.2%), security threat (18.4%), and physical violence (13.9%). The prevalence of sexual risk behavior, good ART adherence, depression, anxiety, and suicidal ideation was 55.1%, 53.4%, 48.3%, 32.3%, and 65.0%, respectively. Abuse of methamphetamine (METH) (aOR:2.79; 95%CI:1.43 ~ 5.45), capsule 0 or stimulating liquid (aOR:2.68; 95%CI:1.31 ~ 5.47), Magu (aOR:3.16; 95%CI:1.51 ~ 6.60), and other new drugs (aOR:2.87; 95%CI:1.52 ~ 5.43), disclosing HIV infection to partners (aOR:2.03; 95%CI:1.10 ~ 3.78), and gay sexual orientation (aOR = 3.32; 95%CI: 1.82 ~ 6.05) were significantly correlated with the experience of IPV. In addition, IPV was significantly associated with sexual risk behavior (aOR = 2.02; 95%CI:1.16 ~ 3.53), ART adherence (aOR = 2.63; 95%CI:1.46 ~ 4.74), depression (aOR = 3.83; 95%CI:2.09 ~ 7.02), anxiety (aOR = 2.27; 95%CI:1.19 ~ 4.35), and suicidal ideation (aOR = 3.78; 95%CI:2.11 ~ 6.80). Conclusions: IPV is prevalent among HIV-infected MSM and is associated with poor behavioral and mental health, highlighting more efforts are needed to address this issue. The finding that new drug abuse, HIV disclosure, and gay sexual orientation are associated with increased risk of IPV provides essential insights for the development of comprehensive and targeted IPV prevention and intervention programs in the future. [ABSTRACT FROM AUTHOR]

Incorporating T-shaped steel and square steel tubes into a cross shaped concrete column can significantly improve the seismic performance of the cross shaped column. However, the experimental samples are limited, so ABAQUS finite element (FE) analysis method was adopted in this paper to study the seismic performance of this cross shaped column, calculate and verify three specimens in the existing reference. Based on the reliable model, parameter analysis was carried out (25 specimens in total). The results show that the established model has a high degree of coincidence in the hysteretic curve, skeleton curve and failure mode, and the error of ultimate bearing capacity and ductility is within 10%. The configuration of T-shaped steel and square steel tubes inside the cross column can meet the ductility requirements specified in the standard under high axial compression ratio. The ultimate bearing capacity of the cross shaped column increases with the increase of the thickness of the square steel tube, but the ductility deteriorates. The increase in steel tube size increases the strength of the concrete in the core area, and the seismic performance of the cross shaped column was improved. Increasing the thickness of the T-shaped steel flange can better improve the seismic performance of the cross shaped column compared to increasing the thickness of the T-shaped steel web plate. Increasing the height of the specimen will significantly reduce its seismic performance. When the shear span ratio is not greater than 4.1, the ductility can meet the standard requirements. The error of the formula for calculating the compression-bending bearing capacity proposed based on existing calculation methods is less than 5%. [ABSTRACT FROM AUTHOR]

Offshore wind farms have emerged as an effective method for responding to the energy crisis. However, offshore wind power generation has been indiscriminately planned at sea, leading to interference with the traffic routes of merchant ships. Many countries and organisations have set buffer zone standards to ensure the safe navigation of passing vessels, but these standards differ widely. As a typical example, the standards of the International Maritime Organization (IMO) and those of the Confederation of European Shipmasters' Associations (CESMA) are used to decide the route widths of vessels; however, they both have limitations, preventing their application to all sea areas. This study proposes a novel methodology to calculate the width of a route using distribution and line density analyses of 90% and 50% maritime traffic. First, four categorised maritime routes and gate lines are established to comparatively analyse the width of maritime traffic routes. Next, to ensure reliability-based route safety, the compliance of extracted maritime traffic route widths with the criteria established by the IMO and CESMA is verified. The selection of optimised widths for vessel traffic routes will ensure the safe navigation of maritime traffic and encourage the sustainable development of maritime spaces. [ABSTRACT FROM AUTHOR]

The concept that classic waves reflected from a rotating absorbing cylinder will be amplified is analogously linked to the Penrose superradiance that may extract energy from a rotating black hole. The superradiance of acoustic waves carrying orbital angular momentum (OAM) from a sound absorber has been demonstrated in a recently published experiment using two rotating microphones. The experiment showed that the waves were amplified by up to 30% when the rotation rate of the absorber satisfied the Zel'dovich condition. Here, we proposed an experimental method to detect acoustic superradiance by static microphones. We demonstrated that the acoustic waves transmitted through a perforated absorber were amplified (by up to 1000%) even when the Zel'dovich condition was not satisfied. The experiment also showed that when the Doppler-shifted frequency of an observer was 0 Hz, the acoustic amplitude was very weak regardless of the rotation rate of the absorber. Our work was worthwhile not only in the proposed experimental method that was well-suited for observing the acoustic OAM wave but also in the high amplification achieved at a low rotation rate of the perforated absorber, showing a great prospect in practical applications such as amplifying the information-carrying OAM waves for high-speed acoustic communication. [ABSTRACT FROM AUTHOR]

The underwater muzzle transient flow field is an unsteady, multiphase complex flow field interacting with projectiles and containing various shock wave structures. The turbulent mixing of gunpowder gas and water has a significant impact on the development of the muzzle gas flow field. Moreover, the muzzle gas flow field disturbs the motion of the projectile, thereby affecting shooting accuracy. As part of this research, an unsteady multiphase flow model of the underwater muzzle transient flow field is established by combining the theories of multiphase flow and turbulent mixing. The volume of fluid model is employed to trace the two-phase interface, while the gas–liquid turbulent mixing is described by the standard k–ε turbulence model. Furthermore, the cavitation model is used to describe the cavitation phenomenon caused by the motion of the projectile. The established numerical model is validated by comparing underwater launching experimental results. Accordingly, the muzzle flow field of a 30 mm underwater gun under different water depth conditions is numerically calculated. The results demonstrate that, as the water depth increased, the gunpowder gas is exposed to relatively high water pressure during the expansion process, resulting in a continuous decrease in the core area of the gas, and the Mach disk is also increasingly closer to the muzzle. At different water depths, the diameter of the Mach disk conforms to the binomial law with time, while the displacement of the Mach disk from the muzzle increases exponentially with time. [ABSTRACT FROM AUTHOR]

The digital economy is gradually becoming a powerful engine for high-quality economic development in China and plays an important role in the construction of digital villages and the integrated development of rural industries. Starting from the mechanism of reducing transaction costs in the digital economy, it is a feasible perspective to analyze the role of the digital economy in promoting the integration and development of rural industries in China. This paper evaluates the impact of the digital economy on the development of rural industries in China, analyzes the current situation and problems in the construction of digital villages in China, and uses transaction cost theory to analyze the role of digital technology applications in reducing transaction costs in agricultural production, sales, and financial services. It finds out various rural industrial integration modes formed in the process of digital rural construction, and proposes policy suggestions to promote the integrated development of digital economy and rural industries in China. [ABSTRACT FROM AUTHOR]

Seismic data coverage in ocean regions is sparse, and it is highly challenging to build long-term continuous seismic networks in the oceans due to the restrictions related to the shortage of instruments and great costs. The lack of data coverage limits effective seismic imaging of deep mantle structures beneath the oceans, which cover 70% of the Earth's surface. The newly developed Mobile Earthquake Recorder in Marine Areas by Independent Drivers (MERMAID) can drift with ocean currents at a specified depth while recording seismic signals. The Southern University of Science and Technology (SUSTech) launched 10 MERMAIDs in the South China Sea (SCS) in May 2021 that formed the South China Sea Floating Seismic Network (SCS-FSN). We analyzed the one-year-long records of the SCS-FSN, identifying 372 cataloged earthquakes and acquiring 1,015 high-quality travel time data. By analyzing the records of earthquakes with magnitudes above 7.0 and conducting synthetic waveform calculation, we found that, in addition to the epicentral distance and earthquake magnitude, the earthquake identification ability of the network is also affected by the focal mechanism, sea condition, seafloor relief, and MERMAID working state. Although the recognition rate of the SCS-FSN is only 16% for earthquakes with magnitudes above 5.5 and epicentral distances less than 90°, this network is expected to collect more than 5,000 high-quality travel time data during its five-year battery life. These new data will significantly improve the seismic data coverage, compensating for the lack of long-term continuous seismic network observations in the SCS. Most importantly, with this experiment, we are confident that setting up well-designed floating seismic networks in the world's three oceans could solve the world-class problem of the lack of effective seismic data coverage beneath ocean regions. [ABSTRACT FROM AUTHOR]

A simplified rectangular thin-wing model with a spanwise rib is proposed to investigate the influence of the front limb and fingers embedded in the bat membrane wing on aerodynamics. The leading edge rib-enhanced wing (LRW) and the middle rib-enhanced wing (MRW) have been studied numerically in two-dimensional plunging and three-dimensional flapping motions. It is found that the aerodynamic features of the plunging and flapping wings are similar, i.e., the spanwise cylindrical rib only affects the chordwise forces on the model wings and almost does not change the normal forces. In particular, the leading edge rib-supporting structure increases the thrust due to the large region of low pressure on the rib's head when the wing moves in moderate or large amplitudes. When the rib is placed far away from the leading edge, the influence decreases rapidly. Furthermore, the effects of spanwise rib-enhanced wing are independent of Reynolds number when it is greater than 1000. The present study can assist in the design of rib-enhanced wings for bionic flapping-wing air vehicles. [ABSTRACT FROM AUTHOR]

In the construction industry, collision accidents between excavators and workers can result in a significant number of fatalities. Hence, low-cost supervision systems are necessary to monitor the motion status of excavators and extract the dynamic hazardous proximity zones around these excavators. Recent computer vision–based methods are convenient and economical, and they also do not require the installation of additional sensors on excavators; however, most of these methods only focus on two-dimensional (2D) or static hazardous proximity zones, which are excessively rough for the fine management required at construction sites. Therefore, a framework for the three-dimensional (3D) dynamic hazardous proximity zone design of excavators based on real-time 3D pose estimation is proposed herein. For this purpose, a set of excavator 3D pose estimation algorithms containing the 2D keypoint detection module and 2D-to-3D lifting module were trained based on two corresponding data sets, one of which was collected on the Internet and the other was generated via Cinema4D software. The real-time motion status was calculated based on the 3D poses estimated from the video after postprocessing and coordinate transformation. Moreover, trajectories could be predicted to form the 3D dynamic hazardous proximity zone for an excavator. Notably, this study developed a computer vision–based pipeline for sensor-free excavator 3D pose estimation and applied the 3D pose estimation algorithm to a specific management issue, thus providing a reference for excavator–worker collision prevention and transforming the conventional static and general onsite construction safety management to a dynamic and specific one. [ABSTRACT FROM AUTHOR]

Ultra-weak fiber Bragg grating (UWFBG) array-based phase-sensitive optical time-domain reflectometry (Φ-OTDR) utilizes the interference interaction between the reference light and the reflected light from the broadband gratings for sensing. It significantly improves the performance of the distributed acoustic sensing system (DAS) because the intensity of the reflected signal is much higher than that of the Rayleigh backscattering. This paper shows that Rayleigh backscattering (RBS) has become one of the primary noise sources in the UWFBG array-based Φ-OTDR system. We reveal the impact of the Rayleigh backscattering signal on the intensity of the reflective signal and the precision of the demodulated signal, and we suggest reducing the pulse duration to improve the demodulation accuracy. Experimental results demonstrate that using light with a 100 ns pulse duration can improve the measurement precision by three times compared with the use of a 300 ns pulse duration. [ABSTRACT FROM AUTHOR]

Since people spend most of their time inside buildings, indoor air quality (IAQ) remains a highlighted topic to ensure in the built environment to improve public health, especially for vulnerable users. To achieve a better indoor environment quality (IEQ), some countries' governments or regional institutions have developed and published reference guideline values of various air pollutants to prevent the IAQ from becoming adverse to occupants. Beyond guidelines by World Health Organization (WHO), in some countries, there are specific institutional requirements on the IAQ, and others integrated it into the building regulation for the built environment. This paper is based on the literature research, summarized from previously conducted works by the authors, on the chemical reference values of IAQ-related regulations and guidelines published by several Governments or related institutions from various regions around the World. Despite these efforts at standardization and legislation, many indoor air quality monitoring activities conducted in several countries still fall short of the main indications produced. By comparing the reference values of 35 pollutants, both physical and chemical ones, which are proposed in documents from 23 regions included so far, the IAQ research and prevention actions on progress in different regions should be included in monitoring plans with guidelines/reference values in their current state. The outcome of the paper is to define the current trends and suggest some perspectives on the field of interest for improving the indoor air quality of generic spaces at an international level. It becomes evident that, at the global level, IAQ represents a complex political, social, and health challenge, which still suffers from the absence of a systematic and harmonized approach. This is not a new situation; the issue was raised more than 40 years ago, and despite efforts and a pandemic, the situation has not changed. [ABSTRACT FROM AUTHOR]

An oxalate-assisted strategy was first developed for creating new polyoxotantalates (POTas). With this strategy, two brand-new POTa supramolecular frameworks based on uncommon dimeric POTa secondary building units (SBUs) were constructed and characterized. Interestingly, the oxalate ligand can not only serve as a coordination ligand to form unique POTa SBUs but also act as a key hydrogen bond acceptor to construct supramolecular architectures. Besides, the architectures show outstanding proton conductivity. The strategy opens up new opportunities for developing new POTa materials. [ABSTRACT FROM AUTHOR]

Previous studies have reported that E2F transcription factor 1 (E2F1) and DNA topoisomerase II alpha (TOP2A) are up-regulated in gastric cancer (GC), the corresponding unexplored regulatory mechanisms and the interactions of which in GC are worth figuring out. In this study, the expressions of E2F1 and TOP2A in GC tissues were assessed by real-time PCR (RT-PCR), and E2F1 binding sites in the TOP2A promoter region were predicted via bioinformatics analyses and confirmed using dual-luciferase reporter and ChIP assays. The viability, apoptosis, migration, and invasion of GC cells after transfection with sh-E2F1 or TOP2A plasmid were measured using methyl thiazolyl tetrazolium (MTT) assay, Hoechst 33258 staining/Annexin V/PI staining, and transwell assay. The expressions of E2F1, TOP2A, Cleaved caspase-3, Proliferating cell nuclear antigen (PCNA), E-cadherin, N-cadherin, and Vimentin in transfected cells were assessed by reverse transcription quantitative PCR (RT-qPCR) and western blot. Concretely, E2F1, as a transcription factor, has binding sites in the TOP2A promoter region. E2F1 and TOP2A levels were up-regulated and positively correlated with each other in GC tissues, i.e., overexpressed E2F1 increased TOP2A levels and E2F1 silencing decreased TOP2A levels in GC cells. Moreover, E2F1 silencing hindered GC cell viability, migration, and invasion, enhanced apoptosis, diminished the levels of PCNA, N-cadherin and Vimentin, and elevated those of Cleaved caspase-3 and E-cadherin in GC cells. However, overexpressed TOP2A reversed the above effects of E2F1 silencing. To sum up, E2F1-mediated up-regulation of TOP2A promotes the viability, migration, and invasion, and inhibits the apoptosis of GC cells. [ABSTRACT FROM AUTHOR]

Among the various kinds of adjustment methods to improve the material properties of recycled aggregate concrete (RAC), equivalent mortar volume (EMV) method is widely considered as economic and effective. This is mainly because that only an extra content of natural aggregates (NAs) is needed to be added in the mixture during fabricating RAC. To objectively evaluate the method, this study conducted a series of discrete element mesoscale simulations to illustrate and compare the mechanical behaviors and failure mechanisms for conventional and EMV methods designed RAC samples under uniaxial loadings. Particularly, the influences of the replacement ratio of RAs, the mixture's water-to-cement ratio and the spatial location of coarse aggregates on the two RACs' strength and deformation characteristics were analyzed. Additionally, generic expressions used for estimating the mechanical properties of conventional and EMV methods cast RAC samples were also tried to be established in the article. It was found by this study that: (a) As the replacement ratio grows, both the conventional RAC's compressive strength and elastic modulus reduce monotonously, however, the tensile strength's variation trend is highly dependent on the relative strength of new-to-old mortar; (b) Regardless of the RAC's water-to-cement ratio, an EMV design method can always improve the elastic modulus of RAC effectively; (c) When the new mortar strength is lower than that of old mortar, adopting an EMV mix-design method notably improves the RAC's tensile and compressive strengths, however, if the old mortar strength is obviously smaller, the EMV method's enhancement to the concrete's strength is limited; (d) Variabilities for compressive and tensile strengths of EMV method designed RAC samples are commonly higher than those of conventional RAC samples; and (e) Uniaxial mechanical property of RAC sample cast either using a conventional or EMV method can both be predicted with a same formulas. [ABSTRACT FROM AUTHOR]

Background. Hepatocellular carcinoma (HCC) is a very common malignant tumor. Long noncoding RNAs (lncRNAs) enable discoveries of new therapeutic tumor targets. We aimed to study the role and potential regulatory mechanisms of the lncRNA KIF9-AS1 in HCC. Methods. CCK-8, scratch assay, and flow cytometry were used to detect cell proliferation, migration, and apoptosis, respectively. Bax, Bcl-2, ERK, and pERK expression were measured by western blotting. StarBase predicted KIF9-AS1 expression in HCC and paracancerous tissues. RPISeq predicted the interaction score of KIF9-AS1 and DNMT1, and MethyPrimer revealed the CpG island distribution in the RAI2 promoter. MSP was performed to measure RAI2 methylation. RIP and ChIP were performed to examine lncRNA KIF9-AS1, DNMT1, and RAI2 interactions. Finally, the effect of KIF9-AS1 knockdown on HCC was verified with nude mice. Results. We found that KIF9-AS1 expression was increased in HCC tissues. KIF9-AS1 knockdown inhibited the proliferation and migration, and facilitated the apoptosis of HCC cells. lncRNA KIF9-AS1-mediated RAI2 expression led to DNMT1 recruitment and regulated RAI2 DNA methylation. RAI2 overexpression inhibited the proliferation and migration and promoted the apoptosis of HCC cells. KIF9-AS1 knockdown inhibited subcutaneous tumor formation in vivo. Conclusion. This study shows that KIF9-AS1 accelerates HCC growth by inducing DNMT1 promotion of RAI2 DNA methylation. [ABSTRACT FROM AUTHOR]

Combining isolated atomic active sites with those in nanoparticles for synergizing complex multistep catalysis is being actively pursued in the design of new electrocatalyst systems. However, these novel systems have been rarely studied due to the challenges with synthesis and analysis. Herein, a synergistically catalytic performance is demonstrated with a 0.89 V (vs reversible hydrogen electrode) onset potential in the four‐step oxygen reduction reaction (ORR) by localizing tungsten single atoms around tungsten nitride nanoparticles confined into nitrogen‐doped carbon (W SAs/WNNC). Through density functional theory calculations, it is shown that each of the active centers in the synergistic entity feature a specific potential‐determining step in their respective reaction pathway that can be merged to optimize the intermediate steps involving scaling relations on individual active centers. Impressively, the W SAs/WNNC as the air cathode in all‐solid‐state Zn‐air and Al‐air batteries demonstrate competitive durability and reversibility, despite the acknowledged low activity of W‐based catalyst toward the ORR. [ABSTRACT FROM AUTHOR]

Objective: Viscoelastic hemostatic assay (VHA) provides a graphical representation of a clot's lifespan and reflects the real time of coagulation. It has been used to guide trauma resuscitation; however, evidence of the effectiveness of VHAs is still limited. This systematic review aims to summarize the published evidence to evaluate the VHA-guided strategy in resuscitating trauma patients. Methods: The PubMed, Embase, and Web of Science databases were searched from their inception to December 13, 2021. Randomized controlled trials (RCTs) or observational studies comparing VHA-guided transfusion to controls in resuscitating trauma patients were included in this systematic review. Results: Of the 7743 records screened, ten studies, including two RCTs and eight observational studies, met the inclusion criteria. There was great heterogeneity concerning study design, enrollment criterion, VHA device, VHA-guided strategy, and control strategy. Thrombelastography (TEG) was used as a guiding tool for transfusion in eight studies, and rotational thromboelastometry (ROTEM), and TEG or ROTEM were used in the other two studies. The overall risk of bias assessment was severe or mild in RCTs and was severe or moderate in observational studies. The main outcomes reported from the included studies were blood transfusion (n = 10), mortality (n = 10), hospital length of stay (LOS) (n = 7), intensive care unit LOS (n = 7), and cost (n = 4). The effect of the VHA-guided strategy was not always superior to the control. Most of the studies did not find significant differences in the transfusion amount of red blood cells (n = 7), plasma (n = 5), platelet (n = 7), cryoprecipitate/fibrinogen (n = 7), and mortality (n = 8) between the VHA-guided group and control group. Notable, two RCTs showed that the VHA-guided strategy was superior or equal to the conventional coagulation test-guided strategy in reducing mortality, respectively. Conclusion: Although some studies demonstrated VHA-guided strategy probable benefit in reducing the need for blood transfusion and mortality when resuscitating trauma patients, the evidence is still not robust. The quality of evidence was primarily downgraded by the limited number of included studies and great heterogeneity and severe risk of bias in these. Further studies are strongly recommended. [ABSTRACT FROM AUTHOR]

A convenient and sensitive liquid chromatography–tandem mass spectrometry method was established to simultaneously quantify voriconazole (VRZ) and its metabolite, voriconazole N -oxide (VNO), in human urine. Voriconazole-d3 and voriconazole-d3 N -oxide were used as isotopic internal standards. Samples were processed by protein precipitation and separated using a ZORBAX SB-Aq column (1.8 μm, 2.1 × 50 mm). Mass spectrometry was performed using an API 4000 mass spectrometry by positive electrospray ionization. The flow rate was 0.6 mL/min. Gradient elution was performed with methanol and 0.1% formic acid as the organic and water phase, respectively. The VRZ and VNO calibration curves ranged from 20.0 to 7200 ng/mL in human urine. The specificity, matrix effect, extraction recovery, intra/inter-run precision, accuracy and stability were validated for both VRZ and VNO in human urine. The developed method was used to study urinary excretion after intravenous injection of 4 mg/kg VRZ in healthy Chinese subjects. [ABSTRACT FROM AUTHOR]

Anti‐counterfeiting has become a serious issue around the global world; fluorescence‐based tags are praised for the low‐cost and facile decryption process. However, the high‐level anti‐counterfeiting application requires incorporating multifunctional luminescent materials with response to different excitation sources. Herein, a dimeric Cu(I)‐halide‐clusters‐assembled single‐crystal (AEP)2Cu2I6·2I·2H2O (AEP = N‐aminoethylpiperazinium) concerning a high down‐conversion photoluminescence quantum yield (PLQY) value of near unity is reported (λex = 305 nm), which can also be activated by the near‐infrared light and X‐ray. The ultrafast spectroscopy and density functional theory calculations reveal that the broad‐band emission originates from the recombination of self‐trapped excitons. Remarkably, the high PLQY and excellent attenuation capability for X‐ray confers an outstanding light yield of 55 650 photons MeV−1 to (AEP)2Cu2I6·2I·2H2O, which is 5.25 times higher than the standard bismuth germaniumoxide scintillator. Such multi‐light‐stimulus response endows (AEP)2Cu2I6·2I·2H2O with great application potential in anti‐counterfeiting, solid‐state lighting devices, and digital radiography. [ABSTRACT FROM AUTHOR]

Atlantoaxial instability (AAI) in dogs refers to abnormal motion at the C1–C2 articulation due to congenital or developmental anomalies. Surgical treatment options for AAI include dorsal and ventral stabilization techniques. Ventral stabilization techniques commonly utilize transarticular and vertebral body screws or pins. However, accurate screw insertion into the vertebrae of C1 and C2 is difficult because of the narrow safety corridors. This study included 10 mixed dogs, 1 Pomeranian, and 1 Shih-Tzu cadaver. All dogs weighed <10 kg. Each specimen was scanned using computed tomography (CT) from the head to the 7th cervical vertebrae. This study used 12 bone models and 6 patient-specific drill guides. Bone models were made using CT images and drill guides were created through a CAD (computer-aided design) program. A total of six cortical screws were used for each specimen. Two screws were placed at each of the C1, C2 cranial, and C2 caudal positions. Postoperative CT images of the cervical region were obtained. The degree of cortex breaching and angle and bicortical status of each screw was evaluated. The number of screws that did not penetrate the vertebral canal was higher in the guided group (33/36, 92%) than in the control group (20/36, 56%) (P = 0.003). The screw angles were more similar to the reference angle compared to the control group. The number of bicortically applied screws in the control group was 28/36 (78%) compared to 34/36 (94%) in the guided group. Differences between the preoperative plan and the length of the applied screw at the C1 and C2 caudal positions were determined by comparing the screw lengths in the guide group. The study results demonstrated that the use of a patient-specific 3D-printed drill guide for AAI ventral stabilization can improve the accuracy of the surgery. The use of rehearsal using bone models and a drilling guide may improve screw insertion accuracy. [ABSTRACT FROM AUTHOR]

Understanding the variations in activity of enzymes involved in the immune response of insects is important for developing effective microbial insecticides against pest species, the determination of bacteria dosage that caused variation of enzyme activities would assist us to prepare effective concentrations of microbial insecticides. In this study, we measured the activities of acid phosphatase (ACP), phenoloxidase (PO), peroxidase (POD), glutathione peroxidase (GSH-px), glutathione reductase (GR), and glutathione S-transferase (GST) in haemocytes and serum of larvae of the pest Heterolocha jinyinhuaphaga Chu (Lepidoptera: Geometridae) infected with Escherichia coli at different time points post-infection. Infection of fifth-instar larvae with different dosages of E. coli led to significant increases in the activities of these enzymes in haemocytes and serum at 3, 6, 12, and 24 h post-infection. Enzyme activities in haemocytes peaked at 6 h post-infection, but their activities began to decrease at 12 h post-infection. Enzyme activities in serum peaked at 12 h post-infection, and they began to decrease at 24 h post-infection. Additionally, enzyme activities increased with increasing dosages of E. coli. The activities of ACP, PO, POD, and GSH-px peaked at 1 × 107 indiv/mL, and the activities of GR and GST peaked at 1 × 106 indiv/mL, activities decreased thereafter. Two - way analysis of variance showed that the interaction of infection time and dosages of E. coli had no significant effect on the enzyme activities in haemocytes and serum of H. jinyinhuaphaga larvae (P > 0.05). [ABSTRACT FROM AUTHOR]

With the advances of the fifth generation (5G) mobile communication technology, smart applications enhance the quality of daily life, the urban management by the government and the effective allocation of resources. Smart applications collect data through the Internet of Things, store massive data in the cloud server, and use cloud computing and deep learning to analyze the data, according to the data analysis results to guide human production and life. However, with the breakthrough of 6G technology, the amount of data applied is increasing, and the demand for privacy protection is becoming more prominent. Encrypting data using traditional cryptographic algorithms can solve the problem of privacy leakage, but it hampers the availability of the data. Searchable encryption is a special encryption structure with keyword search, which balances the availability and privacy of massive data. In this article, we analyze some typical security and privacy issues in 6G-based applications, discuss the solutions to these problems, and present a framework of 6G-based smart cities with searchable encryption, which provides a guarantee for the privacy and availability of smart city data (including ciphertext search, access control, etc.). We also propose a searchable encryption solution based on ciphertext-policy attribute-based encryption to solve the conflict between security and data availability of the smart cities as a specific scenario in order to demonstrate the contribution of cryptographic technologies such as public-key searchable encryption to the 6th generation mobile communication technology. [ABSTRACT FROM AUTHOR]

Understanding the types of haemocytes involved in the immune response in insects, and the mechanism involved in determining that response, can provide a scientific reference for developing effective microbial insecticides. Therefore, the current study examined haemocytes from Agrotis ipsilon (Hufnagel) larvae infected with Escherichia coli in terms of their morphology, total counts, and relative proportions at different time points post-infection by optical microscopy technology. The results revealed six types of haemocytes (prohemocytes, plasmatocytes, granulocytes, spherule cells, oenocytoids, and cystocytes) in the haemolymph of sixth-instar larvae. Haemocyte deformation, disruption, nuclear changes, and vacuoles were recorded after infection with different dosages of E. coli. At each time period post-infection, the total haemocyte count was significantly higher than in the controls, peaking at 24 h post-infection and then decreasing by 48 h post-infection. The proportion of prohemocytes decreased significantly until 24 h post-infection, and then began to increase. By contrast, the proportions of plasmatocytes, granulocytes, spherule cells, oenocytoids, and cystocytes relatively increased, and peaked by 24 h post-infection, and then decreased. This revealed that strong immune response was stimulated in larva of A. ipsilon in a short time after infection with E.coli, and the results shed addition light on the cellular immune response of insects to pathogens. [ABSTRACT FROM AUTHOR]

In order to improve the effect of financial risk aversion, this paper studies the financial risk aversion system combined with the edge computing method of the sensor network and proposes a sensor data anomaly detection algorithm based on the offset distance. Moreover, this paper divides the sensor data into several sliding windows according to the time series, analyzes the offset between the data object and other data in the sliding window by calculating the offset distance, and uses the abnormal level to indicate the possibility of data abnormality. In addition, this paper analyzes the single-layer linear network model for the data with high abnormal level and constructs a financial risk aversion model based on the edge computing of the sensor network. The simulation test results show that the financial risk aversion model based on sensor network and edge computing proposed in this paper meets the actual needs of financial risk analysis. [ABSTRACT FROM AUTHOR]

Using the photosensitized Ru(N∧N∧N)2-metalloligand, a series of Ce frameworks were synthesized. The incorporation of the visible-light-responsive Ru(N∧N∧N)2-unit endows the Ce frameworks with photocatalytic activities in both sulfide oxidation and hydrogen production. The doping of Zr and particularly the oxidation state of Ce has great influence on the photocatalytic properties of the Ce frameworks. [ABSTRACT FROM AUTHOR]

Prostate cancer (PCa) is one of the most common malignancies in men with high death rate worldwide. Paclitaxel (Taxol) is a widely used anticancer agent. Despite recent improvements in clinical application and research, development of drug resistance limits the efficacy of the Taxol-based chemotherapy. Previous studies revealed that the long noncoding RNA DANCR positively regulated progression of prostate cancer. However, the precise roles of DANCR in the Taxol sensitivity of PCa and the underlying molecular mechanisms remain largely unknown. Here, we report that the expressions of DANCR were significantly upregulated and miR-33b-5p were downregulated in prostate tumor specimens and cells as well as the Taxol-resistant prostate cancer cell line (PC3-TXR). Silencing DANCR or overexpressing miR-33b-5p effectively enhanced the Taxol sensitivity of PCa cells. Bioinformatics analysis, RNA pull-down assay, and luciferase assay consistently illustrated that DANCR was associated with miR-33b-5p, leading to downregulation of miR-33b-5p in PCa. Interestingly, glucose metabolism of PC3-TXR cells was remarkedly elevated. The glucose uptake, extracellular acidification rate (ECAR), and glycolysis speed-limiting enzyme expressions were significantly promoted in PC3-TXR cells. We further identified the glucose metabolism enzyme; LDHA was a direct target of miR-33b-5p in PCa cells. LDHA restoration attenuated miR-33b-5p-mediated PTX sensitization. Finally, the rescue of miR-33b-5p in DANCR-overexpressing PC3-TXR cells successfully overrode the DANCR-promoted Taxol resistance. In summary, this study uncovered biological roles and molecular mechanisms of the DANCR-promoted chemoresistance, contributing to the development of noncoding RNA-based therapeutic strategies against drug-resistant prostate cancer. [ABSTRACT FROM AUTHOR]

Biliary tract tumor is a common malignant disease in clinical practice. Its incidence rate and mortality rate are high, which seriously endangers the health of the people. At present, gastrointestinal surgery is mainly used to treat patients at home and abroad. This paper discusses the main risk factors of biliary tract cancer transformation, analyzes its prognostic characteristics and clinical efficacy, and compares them by comprehensive evaluation methods such as observation group control method, blood routine examination and treatment. The results are as follows: the postoperative adverse reactions in the control group are more obvious than those in the experimental group. There were no obvious clinical manifestations or adverse reactions in the experimental group. The therapeutic effect of biliary tumor transformation can effectively help patients improve their quality of life. Through the prognosis recovery of biliary tract tumor transformation treatment, the health level of patients in the experimental group was higher than that in the control group. [ABSTRACT FROM AUTHOR]

We consider an attraction-repulsion chemotaxis model in two dimensions. When the chemoattractant is dominant, it is known that the solutions to the system exist globally, provided that the total mass is less than or equal to some critical value. In this article, we prove the boundedness of solutions with subcritical mass. [ABSTRACT FROM AUTHOR]

The shear transfer mechanism of steel fiber reinforced concrete (SFRC) beams without stirrups is still not well understood. This is demonstrated herein by examining the accuracy of typical empirical formulas for 488 SFRC beam test records compiled from the literature. To steer clear of these cognitive limitations, this study turned to artificial intelligence (AI) models. A gray relational analysis (GRA) was first conducted to evaluate the importance of different parameters for the problem at hand. The outcomes indicate that the shear capacity depends heavily on the material properties of concrete, the amount of longitudinal reinforcement, the attributes of steel fibers, and the geometrical and loading characteristics of SFRC beams. After this, AI models, including back-propagation artificial neural network, random forest and multi-gene genetic programming, were developed to capture the shear strength of SFRC beams without stirrups. The findings unequivocally show that the AI models predict the shear strength more accurately than do the empirical formulas. A parametric analysis was performed using the established AI model to investigate the effects of the main influential factors (determined by GRA) on the shear capacity. Overall, this paper provides an accurate, instantaneous and meaningful approach for evaluating the shear capacity of SFRC beams containing no stirrups. [ABSTRACT FROM AUTHOR]

Outdoor images are significantly degraded by bad weather conditions, such as fog and dust, which seriously limits efficient information extraction by computer vision applications. Most existing weather-degraded hazy image enhancement methods ignore the wavelength dependence of the scattering coefficient and therefore cannot well handle the colorized haze in which the medium transmission varies in different color channels. In this work, we propose a fish retina-inspired method to solve this problem. Fish have special retinal mechanisms for extracting useful information from underwater environments where photons are scattered and absorbed spatially introducing wavelength-dependent degradation of visibility. Due to the similarity between suspensions in water and aerosols in the air, these mechanisms should also be suitable for processing hazy scenes. The proposed method imitates bipolar cells with scene-dependent center-surround receptive fields to eliminate redundant information, ganglion cells with nonlinear processing to boost contrast, and the centrifugal pathway from amacrine cells to the horizontal cells to adaptively protect visual information from excessive lateral suppression. Compared with state-of-the-art methods on various images degraded by fog, haze, or dust, the proposed method shows quite competitive performance both qualitatively and quantitatively. [ABSTRACT FROM AUTHOR]

Bio-inspired long-based undulating fin propulsion is commonly employed in biological autonomous underwater vehicles (BAUVs), while the hydrodynamic characteristics of various undulating patterns are different. To investigate what kind of undulating pattern has outstanding propulsion or braking performance for BAUVs in directional maneuvers, undulations with four basic undulating patterns are numerically examined under the Open-source Field Operation And Manipulation environment at the Reynolds number of 5 × 102, 5 × 103, and 5 × 104, corresponding to viscous, transitional, and inertial flow regimes, respectively. The study is conducted at various non-dimensional phase speeds c (0.5–2.0, normalized by incoming flow speed) at a constant maximum amplitude of 0.08 and a wavelength of 0.5 (both are normalized by the fin cord length) to imitate the long-based fin. The numerical results indicate that the undulating fin motion with the amplitude envelope gradually increasing from the anterior part to the posterior (conical sinusoidal wave) part may be preferable for thrust generation; undulating with the amplitude envelope increasing from the anterior part to the mid part and decreasing toward the posterior (fusiform sinusoidal wave) presents the superior braking performance when the phase speed is low enough. Moreover, the influence of undulating patterns on the wake structure is analyzed. Through further comparative analysis for propulsion and braking performances, the results obtained here may have instructional significance to the propulsion mechanism in bionic design. [ABSTRACT FROM AUTHOR]

To decrease the launching resistance of underwater guns, a new gas-curtain formation method is proposed based on the gas-curtain launching principle, which is setting up several rectangular grooves on the internal wall of the barrel to guide the gas flow to the front of the projectile and form a gas curtain. A three-dimensional unsteady two-phase flow model of the drainage is established. The formation and drainage characteristics of the gas curtain are studied under the different number of grooves with a constant injection area and 10 MPa injection pressure. The results indicate that the circumferential and radial converging effects of multi-gas jets are enhanced, but the axial expansion is enhanced first and then weakened when the number of grooves increases from 4 to 12. The vortex scale in the Taylor cavity increases with the increase in the number of grooves, but the distance moving downstream is shortened. The gas volume fraction in the tube increases with the increase in the number of grooves. However, the drainage efficiency of the gas curtain on the warhead increases first and then decreases with the increase in the number of grooves, while the change of the gas efficiency–cost ratio is just the opposite. [ABSTRACT FROM AUTHOR]

Let M = (a i j) be a n × n matrix. Let S n be the symmetric group on n elements. The second immanant of M is defined as d 2 (M) = ∑ σ ∈ S n χ (σ) ∏ t = 1 n a t σ (t) , where χ is the irreducible character of S n corresponding to the partition (2 , 1 ,... , 1). Let G be a graph with n vertices, and let I and L (G) denote unit matrix and the Laplacian matrix of G , respectively. The second immanantal polynomial of G is defined as d 2 (G , x) = d 2 (x I − L (G)) = ∑ k = 0 n (− 1) k c k (G) x n − k , where c k (G) is the k -th coefficient of d 2 (G , x). The second immanantal polynomials of graphs was first considered by Merris. And he introduced some open problems on the second immanantal polynomials. In this paper, we mainly focus on Merris' problems. We show that the multiplicity of the root p of d 2 (G , x) = 0 is greater than or equal to the p -star degree of G. In particular, if p = 1 , then the result as above answers one open problem proposed by Merris. We also characterize the distribution of the real roots of d 2 (G , x) = 0. Furthermore, we give the recursive formulas of the second immanantal polynomials of graphs. And we characterize the calculating formulas of the coefficients c n − 2 (T) and c n − 3 (T) of trees which they partially answer another problem proposed by Merris. [ABSTRACT FROM AUTHOR]

• Self-galloping of a thin liquid crystal elastomer catenary cable in a steady temperature field is first observed. • The mechanism of self-galloping is elucidated by proposing a thermomechanical model. • The effects of system parameters on the amplitude, frequency and equilibrium position are obtained. • The results are helpful for the design and control of self-galloping LCE catenary systems. Thermally-driven self-sustained motion allows for direct absorption of heat from a steady temperature field to maintain its own continuous motion, making it a valuable technology for thermal sensors, harvesters, and soft robotics. Exploring a straightforward and durable system that operates with self-sustained motion driven by heat is a formidable challenge. Based on a thin liquid crystal elastomer (LCE) fiber, we propose a thermally-driven self-galloping catenary cable system in this paper. Experiments show that the LCE catenary cable can engage in continuous periodic self-galloping in a steady temperature field with gradient. Combining the well-established dynamic LCE model and catenary theory, the governing equations of the self-galloping LCE catenary cable are established and its dynamics are theoretically investigated. The LCE catenary cable always develops into two motion modes, i.e., static and self-galloping modes, according to numerical calculations. The theoretical predictions are in general agreement with the experimental results. The LCE catenary cable maintains the self-galloping by absorbing thermal energy to offset the damping dissipation. The effects of system parameters on the amplitude, frequency and equilibrium position of the self-galloping are also obtained. This LCE catenary cable has advantages in terms of simple structure, customizable size, minimal requirement for movement space, and flexible adjustment, and it is anticipated to satisfy the demands of actual complex scenarios such as thermal sensors, energy harvesters, and autonomous robots. [Display omitted] [ABSTRACT FROM AUTHOR]

In comparison to natural aggregate concrete (NAC), recycled aggregate concrete (RAC) typically exhibits a more diverse composition of materials, heightened variability and greater inherent weaknesses. These characteristics may result in varying effects of specimen size and shape on compressive responses. Within this framework, the present study endeavors to comprehensively investigate these influences on RAC's compressive properties and their underlying mechanisms utilizing discrete element simulation technology. At the mesoscale, RAC is depicted by several components, encompassing both new and old aggregates, mortar and interfacial transition zones. Through integrating contacts for each phase, elucidating mesoscale mechanical responses with a parallel bond model and introducing Weibull random fields to delineate variations in phase properties, this study effectively simulates these mechanical responses. Subsequent extensive calculations scrutinize the repercussions of specimen size and shape on the compressive strength, elastic modulus, peak strain and failure modes of RAC across varying water-to-binder ratios. The study concludes that RAC manifests a size effect, albeit less pronounced than in NAC with an equivalent water-to-cement ratio, yet more significant than in mortar. Moreover, owing to end plate constraints, the reduction in RAC's cubic compressive strength is notably less than its prismatic compressive strength. Based on these findings, it is recommended to establish the strength size reduction coefficient and cube-to-cylinder shape coefficient for RAC at 0.86 and 0.72, respectively. Notably, these values diverge significantly from the respective 0.81 and 0.78 coefficients for NAC. • A mesoscale stochastic discrete element model is developed to study size and shape effects on RAC's compressive behavior. • Size and shape effects of mortar, NAC and RAC under compression are compared. • Size effect on RAC's compressive strength is less pronounced than that of NAC, but more substantial than that of mortar. • Compressive strength conversion coefficient from cube to cylinder for RAC has changed. [ABSTRACT FROM AUTHOR]

Nickel oxide nanoparticles (NiO-NPs) are common nanomaterials that may be released into the environment, affecting the toxicity of other contaminants. Atrazine (ATZ) is a commonly used herbicide that can harm organisms due to its persistence and bioaccumulation in the environment. Although the toxicity of ATZ to earthworms is well-documented, the risk of co-exposure with NiO-NPs increases as more nanoparticles accumulate in the soil. In this study, we investigated the effects and mechanisms of NiO-NPs on the accumulation of ATZ in earthworms. The results showed that after day 21, the antioxidant system of the cells under ATZ treatment alone was adversely affected, with ROS content 36.05 % higher than that of the control (CK) group. However, the addition of NiO-NPs reduced the ROS contents in the earthworms by 0.6 %− 32.3 %. Moreover, analysis of earthworm intestinal sections indicates that NiO-NPs mitigated cellular and tissue damage caused by ATZ. High-throughput sequencing revealed that NiO-NPs in earthworm intestines increased the abundance of Pseudomonas aeruginosa and Aeromonas aeruginosa. Additionally, the enhanced function of the ABC transport system in the gut resulted in lower accumulation of ATZ in earthworms. In summary, NiO-NPs can reduce the accumulation and thus the toxicity of ATZ in earthworms. Our study contributes to a deeper understanding of the effects of NiO-NPs on co-existing pollutants. [Display omitted] • Suitable concentrations NiO-NPs inhibited the uptake of ATZ in earthworms. • NiO-NPs reduces oxidative stress of ATZ in earthworms. • NiO-NPs reduces intestine damage by ATZ in earthworms. • NiO-NPs increases the abundance of Aeromonas aeruginosa in the intestine. [ABSTRACT FROM AUTHOR]