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A bstract We present the first application of color-kinematics (CK) duality at the three-loop level in non-supersymmetric pure Yang-Mills (YM) theory. Building on the minimal deformation approach introduced in [ 1 ], we extend its use to the three-loop Sudakov form factor. Although three classes of unitarity cuts fail under the globally off-shell CK-dual ansatz, a compact and elegant solution is achieved by deforming a single master numerator. The final numerators exhibit Lorentz invariance in d dimensions and take a local form. This method harnesses CK duality’s full potential by enforcing a subset of off-shell dual Jacobi identities for the deformation, offering a promising path toward constructing three-loop amplitudes in non-supersymmetric YM theory and gravity through CK duality and double copy.

Paper-based microfluidic analytical devices (μPADs) have shown great potential in the field of analysis due to their advantages of rapid analysis, environmental friendliness and the ability to realize the flow of fluid without external power. Saliva is an emerging biofluid which is used in diseases diagnostic and screening for the easy collection and the reflection of the physiological state. This review focuses on the fabrication methods for two-dimensional (2D) and three-dimensional (3D) μPADs and their applications on the saliva analysis. In the first part, the flow mechanism in μPADs is discussed. The second part mainly introduces the fabrication methods for the μPADs and compares the different methods. The third part presents the application of μPADs in the detection of biomarkers such as nitrite, glucose, and thiocyanate in saliva. Finally, the research directions of saliva analysis are discussed in the conclusion. There have been a lot of researches on μPADs, but the fabrication methods and applications need to be further studied to meet the commercial needs.

A microfluidic device with a sandwich structure is proposed to achieve label-free and size-selective separation of tumor cells from pleural effusion. The sandwich structure is a co-flow system incorporating an initial sample layer, an isolation layer and the target sample layer. The isolation layer is used to provide a size-selective interface between the initial sample layer and the isolation layer. The relative magnitude of the inertial lift force and the interfacial lift force at the interface only allows exfoliated tumor cells to migrate out of the sample layer. The high interfacial elastic lift force of the isolation layer also enables the device to be used for pleural effusion samples, whose properties usually vary across a wide range. The target sample layer is used for large migration distances of exfoliated tumor cells in the contraction−expansion array (CEA) channel and high separation efficiency. Cell washing is also achieved with the target sample layer, demonstrating the integration of our device. Experimentally, an optimal flow rate ratio of 1:1:6 was obtained to ensure the stability of the sandwich structure, and the collected fluid was all from the target sample layer. A critical polyethylene oxide (PEO) concentration of the isolation layer (500 ppm, η0 = 1.37 mPa·s) was then obtained by particle tests. Twenty-micrometer particles were efficiently separated from different viscoelastic samples (PEO concentration changes from 0 to 400 ppm) at this concentration. For the cell test, exfoliated tumor cells from different pleural effusion samples were successfully separated and washed. The separation efficiency of exfoliated tumor cells and blood cells was about 100% and over 90%, respectively. Compared with a conventional co-flow system of two fluids, this device has great advantages in 1) wide applicability for pleural effusion samples of various viscoelasticity and 2) focusing performance. It shows potential for use in medical research and clinical diagnosis of cancer.

The transition of particle equilibrium pattern was investigated in contraction–expansion array (CEA) microchannel. The experimental results showed that, in addition to ordinary trajectory 1 (a focusing band near the center of the channel), another novel trajectory 2 could appear on the side near cavity sidewall. The effects of cavity dimension, Reynolds number, and particle diameter on the inertial focusing pattern of the particles were explored in detail. The equilibrium position of trajectory 1 will shift from the geometric center of the channel to the wall with cavity due to the influence of secondary flow generated by CEA units. The particles of 20 μm and 15 μm showed ideal focusing, while the particles of 10 μm focused in a wild band. It showed that the asymmetric CEA units can be used to regulate the focusing position of particles. Because of the squeezing action of two vortexes at the entrance of the contraction section, the trajectory 2 can be stable once it appears. In addition, the location of trajectory 2 is less affected by particle diameters and Re. In the same structure, trajectory 2 is more likely to appear with small particle diameter and large Re. Finally, we summarized the critical Re of focusing pattern transition. When it is greater than this critical value, trajectory 1 and trajectory 2 will exist in the channels simultaneously. It could be used to guide the design of the CEA channels. This basic research could provide a guidance to the application of microfluidic particle manipulation technique.

This study proposes an equivalent furniture fire model based on standard combustible assembly and verifies its feasibility as a substitute for real furniture through full-scale experiments and numerical simulations. Experiments show that the peak heat release rate and total heat release of the standard combustible assembly are highly consistent with those of the single-seat sofa. The numerical model has been verified by experimental data. The dynamic characteristics of the heat release rate (HRR) curve are consistent with the temperature evolution process, confirming its reliability for the numerical model. The research on optimizing fire extinguishing parameters is carried out based on this numerical simulation. The results show that the response time of the horizontal sprinkler is 22 s shorter than that of the vertical sprinkler, and the fire extinguishing efficiency is improved. Reducing the sprinkler height to 3 m can accelerate activation and reduce CO2 release. A flow rate of 91.4 L/min can effectively control the fire, but when it exceeds 150 L/min, the fire extinguishing efficiency is significantly reduced. The low response time index sprinkler starts up 88 s faster than the standard type, significantly enhancing the initial fire suppression capability. This scheme provides a safe, economical, and repeatable standardized combustible assembly for fire training and offers theoretical support for the parameter design of intelligent fire extinguishing systems.

Impact-sliding caused by random vibrations between tubes and supports can affect the operation of heat exchangers. In addition, a corrosive environment can cause damage, accelerating the synergism of corrosion and wear. Therefore, the focus of this work was the impact-sliding fretting tribocorrosion behavior of 316L heat exchanger tubes at different halide concentrations. A device system incorporating the in situ electrochemical measurements of impact-sliding fretting corrosion wear was constructed, and experiments on 316L heat exchanger tubes in sodium chloride (NaCl) solution with different concentrations (0.0, 0.1, 0.5, 1.0, 3.5, and 5.0 wt%) were carried out. The synergism between wear and corrosion was also calculated and analyzed. The wear and damage mechanisms were elucidated by correlating the corrosion-wear synergism, morphologies, and material loss rates. The results indicated that the stable wear stage occurred at approximately 9–12 h, after which the corrosion current increased with the expansion of the wear area. As the halide concentration increased, the scale of damage on the wear scars gradually decreased, changing from being dominated by cracks, delaminations, and grooves to being dominated by scratches, microgrooves, and holes. There was an obvious positive synergism between wear and corrosion. The material loss was dominated by pure mechanical wear and wear enhanced by corrosion, but corrosion enhanced by wear contributed more than tangential sliding fretting corrosion. The total mass loss increased gradually in the range of 0.0–0.5 wt% and decreased in the range of 0.5–5.0 wt%. Large-scale damage enhanced by corrosivity and small-scale damage reduced by lubricity dominated the material loss at low and high concentrations, respectively.

Particle/cell washing is an essential technique in biological and clinical manipulations. Herein, we propose a novel circular contraction–expansion array (CCEA) microdevice. It can be directly connected to a needle tip without connection tubes. Its small size and centrosymmetric structure are beneficial to low sample consumption, high connection stability, and a wide application range. Computational fluid dynamics (CFD) simulation results show that the CCEA structure can produce a stronger Dean flow and lead to faster particle/cell focusing than the circle structure and CEA structure with the same length. Experimentally, an optimal flow rate ratio of 1:3 and an optimal total flow rate of 120 μL/min were found to ensure a stable fluid distribution. Under these conditions, rapid focusing of 10–20 μm particles with high efficiencies was achieved. Compared with a normal CEA device using tubes, the particle loss rate could be reduced from 64 to 7% when washing 500 μL of a rare sample. Cell suspensions with concentrations from 3 × 105/mL to 1 × 103/mL were tested. The high cell collection efficiency (>85% for three cell lines) and stable waste removal efficiency (>80%) reflected the universality of the CCEA microfluidic device. After the washing, the cell activities of H1299 cells and MCF-7 cells were calculated to be 93.8 and 97.5%, respectively. This needle-tip CCEA microfluidic device showed potential in basic medical research and clinical diagnosis.

One of the major challenges of guided bone regeneration (GBR) is infections caused by pathogen colonization at wound sites. In this paper, an asymmetric microfluidic/chitosan device was developed to release drugs to inhibit infections and to ensure that guided bone regeneration can be realized. The microfluidic technique was introduced into the GBR membrane for the first time, which demonstrated more controllable drug release, more flexible clinical use and had a lower cost compared with surface treatments and embedded nanoparticles. Based on the theory of diffusion and Fick’s first law, the contact area and concentration gradient were adjusted to realize sustained drug release. The standard deviation of minocycline release over 5 days was only 12.7%, which was lower than the joint effect of porous chitosan discs and nanospheres. The in vitro experiments against E. coli and Streptococcus mutans showed the excellent antibacterial performance of the device (>95%). The in vitro experiments for fibroblasts at the microfluidic side and osteoblasts at the chitosan side showed the satisfactory biocompatibility and the ability of the device to enhance bone regeneration. Therefore, this microfluidic/chitosan device is a promising therapeutic approach to prevent infection and guide bone regeneration.

A bstract We apply the positivity bootstrap approach to SU(3) lattice Yang-Mills (YM) theory, extending previous studies of large N and SU(2) theories by incorporating multiple-trace Wilson loop operators. By utilizing Hermitian and reflection positivity conditions, alongside Schwinger-Dyson (SD) loop equations, we compute rigorous bounds for the expectation values of plaquette Wilson loops in 2D, 3D, and 4D YM theories. Our results exhibit clear convergence and are consistent with known analytic or numerical results. To enhance the approach, we introduce a novel twist-reflection positivity condition, which we prove to be exact in 2D YM theory. Additionally, we propose a dimensional-reduction truncation, where Wilson loop operators are effectively restricted to a lower-dimensional subplane, significantly simplifying computations. SD equations for double-trace Wilson loops are also derived in detail. Our findings suggest that the positivity bootstrap method is broadly applicable to higher-rank gauge theories beyond single-trace cases, providing a solid foundation for further non-perturbative investigations of gauge theories using positivity-based methods.

Current research on wind energy piezoelectric energy harvesters (PEHs) mainly focuses on tandem smooth cylinder energy harvesters; however, the traditional tandem smooth cylinder energy harvester has low voltage output and narrow energy harvest bandwidth. In this study, a D-type bionic fin is designed and installed on a smooth cylindrical surface to improve its performance. The influence of the spacing ratio on the amplitude and voltage of PEHs with D-type bionic fins added under elastic interference was investigated through wind tunnel tests. Three installation positions were designed: only installed upstream, only installed downstream, and not installed upstream and downstream (BARE). It was found that the maximum displacement of the upstream PEH (UPEH) was not apparently affected by the D-type bionic fin. Contrastingly, the fin changed the maximum amplitude from a small to a large spacing ratio for the downstream PEH (DPEH). D-type bionic fin can enhance energy harvest performance by coupling “coupled vortex-induced vibration” and wake induced galloping, increasing the surface velocity of PEHs and expanding the bandwidth of the voltage harvested by the PEHs. Analysis of the power under the experimental wind speed showed that installing D-type fins in the PEHs can increase the output power of the upstream and downstream PEHs by 392.28% and 13%, respectively, compared with that of the BARE-PEH. Additionally, computational fluid dynamics was used to analyze the flow pattern, wake structure, and lift coefficient of the PEHs, and to explain why the upstream D-type bionic fin installation has an impact on the harvest performance of the upstream and downstream PEHs at a spacing ratio of 1.5. This study provides an efficient and simple scheme for designing wind PEHs.