Phase separation of intracellular biological macromolecules plays a crucial role in physiology and disease pathogenesis. In this study, we developed a dynamic phase-separation theory for RNA and RNA-binding proteins (RBPs) within cells based on diffusion dynamics and Hill kinetics. Using a diffusion dynamics model, we characterized the multiphase separation between RNA and RBPs, encompassing multiple phases and multi-component phases. Our findings reveal that the dynamic multiphase separation mechanism of RNA and RBPs within cells is primarily governed by biochemical interactions between them and their specific diffusivity properties. In these biochemical interactions, RNA and RBP bind to each other through binding domains, causing RNA and RBP with rapid diffusion to aggregate and form RNA-RBD complexes with slower diffusion. The diffusion correlation is a result of the biochemical reactions to the formation of multiple condensed phases of RNA and RBP. Additionally, our investigation uncovered periodic oscillations in the biochemical reactions involving RNA-RNA complexes as well as RBP-condensed phase formation and phase separation phenomena. Furthermore, through integration with the mean-field theory, we established a correspondence between the diffusion coefficients and Flory interaction parameters, providing profound insights into the relationship be-tween various interactions and diffusivity in the system, while comprehensively elucidating the physical essence of multiphase separation between RNA and RBPs. These findings highlight the dissipative structural characteristics associated with condensates formed by periodic oscillations in biochemical reactions involving RNA-RBP complexes. Importantly, it can be predicted that, apart from diffusion effects or changes in solubility, phase separation between RNA and RBPs may also occur owing to periodic changes in their biochemical reactions. These results are consistent with the experimental results of important factors contributing to intracellular phase separation, and provide a valuable reference for subsequent research endeavors.

Microfluidic technology is effective for constructing artificial microvascular tissues in vitro. A three-layer microfluidic chip was reported to use a polycarbonate (PC) porous membrane to separate culture fluid channels from tissue chambers. The micro-porous structure of the PC porous membrane formed a capillary bursting valve in the vertical direction to allow the hydrogel to fill the tissue chambers under the surface tension of the fluid and keep it from leaking into the culture fluid channels to ensure that the three-dimensional fluid microenvironment was effectively constructed. A COMSOL finite element model was established to simulate the three-dimensional fluidic microenvironment of a sin-gle rectangular chamber, and it was used to demonstrate that the three-layer microfluidic chip could provide a flow environment to stimulate blood vessel formation. The vascular differentiation abilities of endothelial progenitor cells and human umbilical vein endothelial cells were tested using the proposed three-layer microfluidic chip, and multiple shapes of microvessel networks cultured for up to approximately eight days were constructed on top of the multi-tissue chamber array chip. This three-layer microfluidic chip had the design flexibility to change the shape of the tissue chambers to provide different fluidic conditions at high throughput and provided a potential engineering tool to study the effects of fluidic factors on microvascular growth.

 Stress analysis for the correction of scoliosis with Harrington rod and Luque rod involved calculation of the changes in stress in various thoracolumbar spine segments based on strength theory. After correction with the Harrington rod, the Cobb angle reduced to (49.57±2.79)^◦ and after correction with the Luque rod, the Cobb angle reduced to (39.43±1.94)^◦. The bending and shear stresses of the spine increased significantly with an increase in the Cobb angle (r=0.26, p <0.05). The mean bending stress in the thoracic spine segments (106.62±9.57) MPa was greater than the mean bending stress in the lumbar spine segments (103.19±8.05) MPa. The mean shear stress in the thoracic spine segments (32.80±2.60) MPa was greater than the mean shear stress in the lumbar spine segments (30.95±2.26) MPa. The mean composite stress in the thoracic spine segments and the lumbar spine segments were (123.79±7.52) and (120.78±7.00) MPa, respectively. When the Cobb angle was 62^◦, the composite stress in each segment was higher than the normal human body stress value, with the maximum composite stress occurring in the T7 ∼ T12 segments. These data provide a theoretical basis for the future correction of scoliosis.

Intramedullary nail fixation of the fracture surface is the primary method of hip fracture treatment, and its mechanical reliability is key to ensuring treatment success. In this study, a finite element model of an intramedullary fixation system (IFS) for intertrochanteric fractures was constructed. This model considers the layered structure of the femur and muscle forces. The mechanical response of the IFS was simulated under slow walking conditions. The concept of a safety factor was proposed to quantitatively evaluate the mechanical reliability of the IFS. Based on this concept, the influence of the positioning parameters of a lag screw on the reliability of the IFS was systematically investigated. Severe stress concentrations are found at the contact regions between the femur and the lag screw, between the trochanteric nail and the lag screw, and between the trochanteric nail and the locking screw. These stress concentration regions play an important role in determining the mechanical reliability of the IFS. This study also showed that the IFS has good mechanical reliability. Reducing the lag screw height improves the mechanical reliability of the system, whereas the effect of the proximal nail angle on the reliability is negligible.

Fecal coliform serves as an indicator of microbial contamination in water and, consequently, water quality. Chlorine disinfection is required to meet effluent standards for conventional sewage treatment; however, it incurs high costs and poses stability risks. This study purified waste effluent from a biological laboratory using an enhanced mobile biofilm reactor (EMBR) filled with biofilm carriers and investigated the removal efficiency of fecal coliforms. Results showed that the biocarrier flask, without ultraviolet (UV) treatment, achieved a 95% removal rate. Notably, removal rates exceeded 99.9% for both fecal coliforms and E.coli phages in the EMBR effluent, with an average phage titer of only 22.2±38.5 PFU/mL. The total bacterial concentration decreased from an average of 10⁷ to 10³ CFU/mL. Effluent quality met Class 1 A discharge limits. Furthermore, the biological safety test indicated a 100% survival rate of zebrafish after 24 h. These findings demonstrate that the EMBR process enables biosafe discharge treatment for biological laboratory wastewater and holds significant application potential.

Advanced oxidation processes (AOPs) are widely used to degrade organic pollutants in aqueous solutions due to their ability to generate highly reactive radicals. However, the traditional Fenton reaction is limited by its required pH range of 2.8∼3.5 and the formation of Fe sludge. This study presents a hydroxyl radical filtrate containing highly active aluminum ions, prepared by filtering the reaction suspension of an Al+acid+H₂O₂ system. The filtrate effectively degraded oxytetracycline (OTC) in aqueous solution. The effects of Al dosage, reaction time, H₂O₂ concentration, and pH of filtrate preparation on oxytetracycline degradation efficiency were systematically investigated. Additionally, the mechanism underlying hydroxyl radical generation in the filtrate was analyzed.

Dust particles adsorb a large amount of gaseous pollutant during their transport in air, and the gaseous components adsorbed on the surface of particulate matter could directly contribute to O₃ generation via heterogeneous atmospheric chemical reactions. The mechanisms through which dust aerosols affect the generation of urban atmospheric O₃ are complex as the physical and chemical properties such as absorption capacity and oxidative potential (OP) of the mineral compositions widely differ. In this work, the mechanisms were summarized and analyzed based on field observation data, research conclusions, and reports in the literature. It was found that the heavy metals and main mineral components (e.g. quartz) in dust stored OP and played important roles in the atmospheric chemical reactions involving gaseous pollutants. Suggestions for future researches were also proposed.

Domain adaptation methods aim to assist tasks in a given target domain by using labeling information from a source domain. Domain-wise and class-wise alignments are commonly used as prerequisites for domain adaptation. However, sample-wise information is not fully utilized, which leads to unsatisfactory alignment results. In this study, we fully use sample-wise information from a geometric perspective to obtain a finer structure-preserving alignment. First, we use the smooth triplet loss to obtain a sample-wise alignment based on distribution adaptation. Then, we introduce a structure regularization term to perform domain adaptation to maintain the geometric structure of data, and use the intrinsic steepest descent algorithm to solve the optimization problem to ensure the structure of the solution space. Finally, we compare our approach with state-of-the-art metric learning and domain adaptation algorithms on datasets comprising natural images and medical information. Experimental results are presented to demonstrate the effectiveness of our proposed algorithm.

智能交通; 行人流建模仿真; BP (back propagation) 神经网络; 行人流实验; 迁移学习

: To satisfy the increasing demand for environmental vibration isolation in high-precision equipment, this study proposes a four-parameter vibration isolator based on eddy current damping. The isolator exhibits wideband and high-performance isolation effects. First, the normalized vibration transmissibility of the isolator was established, and the magnetic field distribution and characteristics of the eddy current damping mechanism were analytically derived using Ampere’s circuit current model and superposition theorem of magnetic fields. Subsequently, finite element analysis was employed to simulate and validate the accuracy of the analytical model of the eddy current damping mechanism, thereby providing a basis for the optimization design and performance verification of the four-parameter vibration isolator. Numerical analysis of the isolation performance indicated that compared with two-parameter isolators, the four-parameter isolator exhibits optimal damping in the frequency domain, effectively suppressing the resonance peak while main-taining high-frequency attenuation performance. Although there was a slight loss in the midfrequency range, the overall wideband isolation performance of the system improved. In the time domain, the steady-state response of the four-parameter isolator aligned with the frequency-domain analysis and achieved stability more rapidly, exhibiting superior transient performance. The four-parameter isolator reduced the random excitation from 1.03 mm to 0.22 mm, achieving an isolation rate of 78.6%, which indicates significant isolation effectiveness.

The aim of this study was to simplify the driving system of pneumatic soft robots by developing a lightweight, small, and highly integrated multiple-output logic control valve. In addition, it could be embedded into the robot body as a component, thereby replacing the traditional large and heavy control valves and reducing the number of driving pipes as well as the volume and weight of external driving systems. The relationship be-tween the pre-tightening force of the elastic band and the critical conduction air pressure of the valve was derived, and the model was verified experimentally. Through an application experiment on a typical pneumatic software pipeline robot, the performance advantages of the proposed lightweight multi-output logic control valve for simplifying the driving system of the robot were demonstrated.

Three-dimensional transition metal intercalated dichalcogenides have garnered significant attention owing to their tunable magnetic and electrical transport properties. This study investigated the impact of Fe doping on the magnetic and transport properties of MnNb₃S₆. Iron (Fe) and manganese (Mn) were intercalated into NbS₂ layers in equal proportions via chemical vapor transport (CVT), yielding Fe_0.5Mn_0.5Nb₃S₆ single crystals. Subsequently, the structural, magnetic, and transport properties were characterized. Mag-netic studies indicated a tilt in the easy magnetization axis from the ab-plane to the c-axis compared with that of MnNb₃S₆. Below the critical temperature (TC), an exchange bias was observed along the c-axis, attributed to the disorder introduced by Fe doping. Ad-ditionally, investigations of transport property indicated negative magnetoresistance and an anomalous Hall effect below TC. Further analysis indicated a close correlation between these phenomena and the nontrivial topological magnetic structures.

Under China’s railway-based coal transport system, railway-sea intermodal transport and land-sea complementary transport modes have gradually been developed. However, problems such as imperfect articulation mechanisms and poor information continue to affect the port’s operational efficiency. Through an in-depth analysis of the coordinated operation of trains and ships under the scenario of rail-sea intermodal transport, this study integrates key port operations such as unloading-coal distribution-loading with the goal of minimizing the cost of ship delays, establishing a mixed-integer planning model to study the co-optimization problem of train scheduling and ship coal distribution schemes in coal ports, and designing a heuristic method based on a variable neighborhood search to solve the model. Finally, this study uses a coal port in northern China as an example, conducting computational experiments using data of different sizes to verify the model’s effectiveness and provide management insights for future coal port operations.