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Suitably modified sesbania gum as a biodegradable functional biomaterials was very attractive in many applications. Therefore, a combination of cross‐linking, carboxymethylation, and oxidation was chosen to modify sesbania gum (SG) to expand its use. The experimental results indicated that cross‐linking could be completed not only on SG particles, but also between different SG particles. The cross‐linking decreased the number of surface hydroxyl groups on SG. The sedimentation volume decreased with the increase of phosphorus content of cross‐linked sesbania gum (CLSG). The structure of SG particles was severely disrupted by carboxymethylation and oxidation, while the structure was less affected by cross‐linking. The viscosities of SG and modified SG paste in acidic medium were less than those in neutral medium, while their viscosities in alkaline medium were more than those in neutral medium. Cross‐linking, carboxymethylation, and oxidation could ameliorate the retrogradation of SG, but decrease its swelling power, freeze–thaw stability, acid, and alkaline resistance. The aldehyde groups had good antibacterial activity against Trichoderma harzianum, whereas the carboxymethyl groups and phosphate ester groups showed poor antimicrobial activity against T. harzianum.

This study explores the kinetic behavior of droplets impacting microtextured surfaces under a Leidenfrost temperature, employing high-speed photography and picosecond laser micromachining techniques. The investigation focuses on two types of microtextured surfaces with totally different surface peak–valley features: a negatively skewed surface with micropit arrays (Ssk< 0) and a positively skewed surface with micropillar arrays (Ssk> 0). The results indicate that both microtextured surfaces contribute to a higher Leidenfrost temperature compared with the original smooth surface, which is consistent with previous studies. However, it is worth noting that the Leidenfrost points of the micropit and micropillar surfaces showed opposite trends with the microtexture area occupancy. Specifically, the Leidenfrost temperature on micropit surfaces increases with greater micropit area occupancy, while it decreases on micropillar surfaces under similar conditions, which is mainly attributed to the differential impact of area occupancy on droplet heat transfer efficiency. When the microtexture area occupancy is 50%, it is worth noting that the micropit and micropillar surfaces have nearly same roughness (Sa), but the Leidenfrost temperature was notably higher on the micropit surface with negative skewness (Ssk< 0), which was related to differences in vapor flow dynamics. We further find that the Weber number (We) significantly influences the Leidenfrost point, with the droplet impact wall behavior going through the states of film bounce back, ejecting tiny droplets and bounce back, and ultimately droplet breakup as the Weincreases. The dynamic Leidenfrost point was found to be generally higher than the static point and increases with the We. Finally, we compare the cooling efficiency of these surfaces, and it is found that the micropit surfaces with a negative skewness exhibit superior heat dissipation performance under the same conditions, which proved that the negatively skewed surface may have great potential in high-density heat dissipation technology.

Cardiac signaling pathways functionally important in the heart’s response to exercise often protect the heart against pathological stress, potentially providing novel therapeutic targets. However, it is important to determine which of these pathways can be feasibly targeted in vivo. Transgenic overexpression of exercise-induced CITED4 has been shown to protect against adverse remodeling after ischemia/reperfusion injury (IRI). Here we investigated whether somatic gene transfer of CITED4 in a clinically relevant time frame could promote recovery after IRI. Cardiac CITED4 gene delivery via intravenous AAV9 injections in wild type mice led to an approximately 3-fold increase in cardiac CITED4 expression. After 4 weeks, CITED4-treated animals developed physiological cardiac hypertrophy without adverse remodeling. In IRI, delivery of AAV9-CITED4 after reperfusion resulted in a 6-fold increase in CITED4 expression 1 week after surgery, as well as decreased apoptosis, fibrosis, and inflammatory markers, culminating in a smaller scar and improved cardiac function 8 weeks after IRI, compared with control mice receiving AAV9-GFP. Somatic gene transfer of CITED4 induced a phenotype suggestive of physiological cardiac growth and mitigated adverse remodeling after ischemic injury. These studies support the feasibility of CITED4 gene therapy delivered in a clinically relevant time frame to mitigate adverse ventricular remodeling after ischemic injury.

In this paper, a new four-dimensional (4D) memristive system is presented by introducing a memristor equation to a 3D chaotic system. Firstly, the basic characteristics including existence and stability of equilibrium points, and Kaplan–Yoke dimension for the memristive system are analyzed from a theoretical perspective. The description of the 4D memristive system in the integer-order and the fractional-order cases is given. In both cases, the dynamics with the variation of a system parameter or a derivative order is studied by the numerical simulations. The results show that the integer-order and the fractional-order memristive systems have rich dynamics. Secondly, in order to realize the synchronization for the memristive system, two adaptive synchronization schemes are designed, namely, the identical structure and the different structure synchronization. Numerical simulation results show that the designed synchronization controllers are effective. Finally, a novel image encryption algorithm is expanded to the image encryption for color images based on the memristive system. The simulation results demonstrate the image encryption method based on the memristive system has a perfect encryption effect for the color images.

Intracellular pathogens can survive inside the macrophages to protect themselves from eradication by the innate immune system and conventional antibiotics, resulting in severe bacterial infections. In this work, an antibiotic-free nanocomplex (HA/GA-Fe@NO-DON), exhibiting macrophage-targeted synergistic gas therapy (nitric oxide, NO)/chemodynamic therapy/immunotherapy, was reported. HA/GA-Fe nanoparticles were synthesized by the strong coordination interactions among carboxyl groups of hyaluronic acid (HA), polyphenol groups of gallic acid (GA), and Fe(II) ions. The hydrophobic glutathione (GSH)-responsive NO donor (NO–DON) was encapsulated in HA/GA-Fe nanoparticles to form the final nanocomplexes (HA/GA-Fe@NO-DON). HA on the nanocomplexes guides the macrophage-specific uptake and intracellular accumulation. After the uptake, HA/GA-Fe@NO-DON nanocomplexes could not only generate highly toxic hydroxyl radicals (•OH) by the Fenton reaction and GSH depletion but also release NO when stimulated by intracellular GSH. Meanwhile, the nanocomplexes could trigger an efficient proinflammation immune response to reinforce the antibacterial activity. This work presents the development of antibiotic-free macrophage-targeted HA/GA-Fe@NO-DON nanocomplexes as an effective adjuvant nanomedicine with synergistic gas therapy/chemodynamic therapy/immunotherapy for eliminating intracellular bacterial infection.

Based on multiple-input-multiple-output (MIMO) arc array, this contribution resolves the azimuth aliasing limitations of Fourier-based imaging applied to optimized subsampled arrays. In terahertz (THz) azimuth imaging application, we aim to design a Fourier-based anti-aliasing imaging method for sparsely optimized MIMO arc array to reconstruct the unaliasing THz azimuth image with high azimuth resolution. The implicit array weighting effect of the sparsely optimized MIMO arc array topology on azimuth point spread function (PSF) reconstruction is analyzed by the performance comparison between the sparsely optimized MIMO arc array and the normal case. The effective processing flow path with good performances of anti-aliasing and narrow main lobe on imaging reconstruction is proposed, the idea of which is to introduce the operations of zero padding, aliasing remove, and resample. Therefore, based on this sparsely optimized MIMO arc array topology and the proposed processing flow path, the better azimuth resolution with the limited aperture length and number of transmitters and receivers can be achieved. Finally, a simulation-based THz hair-level target imaging application is presented for validation purpose. Both simulation and experimental results validate the azimuth image capability of 100– $200~\mu $ m.

In recent years, multiple-input-multiple-output synthetic aperture radar (MIMO-SAR) has been an effective scheme for millimeter-wave (MMW) 3-D imaging. Due to the extremely large amount of data in MIMO-SAR, fast imaging algorithms for it have been extensively studied. However, current imaging algorithms for such scheme are unsatisfactory, either being slow with high accuracy or introducing a large number of approximations that compromise imaging accuracy. In this article, we propose an efficient range scaling algorithm (RSA) to fetch up these shortages. We derive the theoretical formulation of RSA applied to MIMO-SAR, which can realize 3-D reconstruction without interpolation and accumulation operations, only by matrix multiplication and fast Fourier transform (FFT). Meanwhile, we analyze the computational complexity and computational error of the algorithm, and compared with the current advanced imaging algorithms (RMA, FSA, etc.), the proposed algorithm has higher imaging speed and is easier to realize real-time imaging. We also propose a new matrix rearrangement method which makes the algorithm more concise and faster. Based on the MIMO-SAR prototype system, experimental validation is carried out in the 75–110 GHz band. Experimental results show that the proposed algorithm has excellent efficiency and accuracy.

In this study, we examined how surface topography and particle medium interact to affect the tribological performance of rubber sliding interfaces, uncovering the mechanisms of particle lubrication under various conditions. We found that microtextured surfaces, created using a mold transfer method, modestly reduced the friction coefficient of rubber under both dry and lubricated states, primarily by altering the real contact area. Additionally, the presence of different microconvex textures on the surface topography significantly influenced rubber’s tribological properties. Our three-dimensional morphological analysis revealed that microtextured rubber surfaces with higher Sa, Sku, and Saland lower Strvalues consistently showed lower friction coefficients during sliding. The friction mechanism was attributed to the combined effects of the material properties, surface topography, and contact area. With the addition of a particle medium, the dry friction coefficient of the rubber interface decreased but exhibited an initial increase, followed by a decrease with increasing particle diameter. When particles were mixed with a water-based cutting fluid, the concentration, diameter, and wettability of the particles significantly impacted the tribological properties due to the synergistic effects of surface topography and particle lubrication. This work enhances our understanding of tribological control for viscoelastic materials through surface design, providing a theoretical basis for the tribological optimization of rubber surfaces.

This paper investigates the moderating role of the macroeconomic environment in the crash risk-policy uncertainty sensitivity. We find that managers have lower risk perception and crash risk is less sensitive to policy uncertainty during periods of economic expansion. Managers’ risk perception is the critical channel through which the macroeconomic environment affects the relationship between crash risk and policy uncertainty. Consequently, when firms’ managers have an accurate understanding of the future economic environment, the moderating effect of economic growth is lower. This manifests in the weaker moderating effect of economic growth for SOEs and firms with stronger managerial ability, lower managerial ownership, and high media attention, which further supports the risk perception channel.

Lithium–sulfur batteries are considered the next generation of energy storage devices, boasting high theoretical capacity, low cost, and environmental friendliness. However, the weak conductivity of sulfur and the shuttle effect of lithium polysulfides (LiPSs) are major challenges hindering lithium–sulfur battery development. Herein, a functional interlayer composite of Fe–Co sulfide/graphene/CNTs (FCS@GC) was prepared. The composite, which benefits from the 3D cross-linked network formed by CNTs and graphene, could avoid the agglomeration effect of the carbon material and enhance the physical adsorption capacity of LiPSs, effectively improving the transfer of Li+/e–. Additionally, the loaded FeCoS4provides the composite with efficient chemical adsorption and conversion capacity of LiPSs, inhibits the shuttle effect at multiple levels, and greatly improves the kinetics. The lithium–sulfur battery, with FCS@GC as its functional interlayer, exhibits a stable specific capacity of 787.5 mA h g–1after 200 charge/discharge cycles at 0.5 C. Furthermore, it showcases an initial cycling capacity of 885.5 mA h g–1at 1 C. In addition, the capacity decay rate per cycle is only 0.036% after 800 cycles. After 110 cycles at a high sulfur loading of 5 mg cm–2, lithium–sulfur batteries with an FCS@GC functional interlayer can still maintain a capacity of 750.5 mA h g–1. The structure of this innovative compound will offer viable solutions for the issue of commercializing lithium–sulfur batteries.

Intracellular bacteria in dormant states can escape the immune response and tolerate high-dose antibiotic treatment, leading to severe infections. To overcome this challenge, cascade-targeted nanoplatforms that can target macrophages and intracellular bacteria, exhibiting synergetic antibiotic/reactive oxygen species (ROS)/nitric oxide (NO)/immunotherapy, were developed. These nanoplatforms were fabricated by encapsulating trehalose (Tr) and vancomycin (Van) into phosphatidylserine (PS)-coated poly[(4-allylcarbamoylphenylboric acid)-ran-(arginine-methacrylamide)-ran-(N,N′-bisacryloylcystamine)] nanoparticles (PABS), denoted as PTVP. PS on PTVP simulates a signal of “eat me” to macrophages to promote cell uptake (the first-step targeting). After the uptake, the nanoplatform in the acidic phagolysosomes could release Tr, and the exposed phenylboronic acid on the nanoplatform could target bacteria (the second-step targeting). Nanoplatforms can release Van in response to infected intracellular overexpressed glutathione (GSH) and weak acid microenvironment. l-arginine (Arg) on the nanoplatforms could be catalyzed by upregulated inducible nitric oxide synthase (iNOS) in the infected macrophages to generate nitric oxide (NO). N,N′-Bisacryloylcystamine (BAC) on nanoplatforms could deplete GSH, allow the generation of ROS in macrophages, and then upregulate proinflammatory activity, leading to the reinforced antibacterial capacity. This nanoplatform possesses macrophage and bacteria-targeting antibiotic delivery, intracellular ROS, and NO generation, and pro-inflammatory activities (immunotherapy) provides a new strategy for eradicating intracellular bacterial infections.

A two-year field experiment was conducted to measure the effects of densification methods on photosynthesis and yield of densely planted wheat. Inter-plant and inter-row distances were used to define rate-fixed pattern (RR) and row-fixed pattern (RS) density treatments. Meanwhile, four nitrogen (N) rates (0, 144, 192, and 240 kg N ha−1, termed N0, N144, N192, and N240) were applied with three densities (225, 292.5, and 360 × 104plants ha−1, termed D225, D292.5, and D360). The wheat canopy was clipped into three equal vertical layers (top, middle, and bottom layers), and their chlorophyll density (ChD) and photosynthetically active radiation interception (FIPAR) were measured. Results showed that the response of ChD and FIPAR to N rate, density, and pattern varied with different layers. N rate, density, and pattern had significant interaction effects on ChD. The maximum values of whole-canopy ChD in the two seasons appeared in N240 combined with D292.5 and D360 under RR, respectively. Across two growing seasons, FIPAR values of RR were higher than those of RS by 29.37% for the top layer and 5.68% for the middle layer, while lower than those of RS by 20.62% for the bottom layer on average. With a low N supply (N0), grain yield was not significantly affected by density for both patterns. At N240, increasing density significantly increased yield under RR, but D360 of RS significantly decreased yield by 3.72% and 9.00% versus D225 in two seasons, respectively. With an appropriate and sufficient N application, RR increased the yield of densely planted wheat more than RS. Additionally, the maximum yield in two seasons appeared in the combination of D360 with N144 or N192 rather than of D225 with N240 under both patterns, suggesting that dense planting combined with an appropriate N-reduction application is feasible to increase photosynthesis capacity and yield.

This paper aims to explore the impact of donors’ trust in project-related information on the dynamic process of charitable crowdfunding propagation in social networks. Firstly, a theoretical model employing the discrete Markov chain and mean field theory is proposed to describe the underlying dynamics of the crowdfunding propagation mechanism, utilizing trust to reveal the corresponding donation behaviors of crowdfunding audiences. Then, a leveraging simulation experiment is conducted to validate the accuracy of the proposed model. The numerical experiments’ results indicate that improving the donors’ trust in project-related information has a more significant impact on crowdfunding propagation than the choice of the social network platform for fund raising. Moreover, achieving success is more feasible through accumulating a substantial amount of social capital than by lengthening the duration of the campaign. Finally, the validity of the model is verified using actual datasets from the Qingsongchou web platform, with relative errors for two projects being only 3% and 7%, respectively. This paper provided novel insights into the internal mechanisms and the dynamic process of crowdfunding, providing initial evidence for what appears to be a crucial and fruitful phenomenon in crowdfunding research.

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Abstract: A combination of cross-linking of glutaraldehyde and its carboxymethylation was selected to functionalize konjac glucomannan (KGM) in a non-homogeneous system to enlarge its utilization. The results showed that the cross-linking and carboxymethylation resulted in the swelling of KGM particles and produced an uneven destruction on KGM particles according to SEM. Besides, the carboxymethylation was more destructive to KGM than the cross-linking. Cross-linking and carboxymethylation were mainly done on larger particles during the functionalization of KGM. Carboxymethylation significantly reduced the thermal stability of KGM, while cross-linking had little effect on it. Cross-linking and carboxymethylation increased the peak temperature and conclusion temperature of KGM. However, the melting enthalpy of carboxymethyl cross-linked konjac glucomannan (CCLKGM) was between cross-linked konjac glucomannan (CLKGM) and KGM. The cross-linking could decrease the onset decomposition temperature of KGM, while the carboxymethylation could enhance this temperature. The acetyl groups in KGM molecular chains were not influenced by cross-linking of the glutaraldehyde according to FTIR. The weak stretching vibration peak of C=O bonds in the FTIR spectra of KGM and CLKGM appeared at the wavenumber of 1740 cm−1. The influence of adding CCLKGM on gelatinization behavior of potato starch was different from that of adding CLKGM. The addition of CCLKGM obviously lowered the setback and breakdown of potato starch, while the addition of CLKGM clearly increased them. Graphical abstract:

The WUSCHEL-related homeobox (WOX) gene family is essential for plant growth and development. However, the identification and evolutionary analysis of WOXgenes in the Cucurbitaceae have not been well investigated. In the present work, we performed a genome-wide analysis to identify WOXgenes in eleven cucurbit crops. In total, 127 WOXgenes were identified in eleven cucurbit crops, and classified into three different clades: the ancient clade, the intermediate clade and the WUS clade. The same clade has comparable gene organization and conserved motif patterns. The cis-acting element analysis revealed that WOXgenes were involved in light, hormone and stress in cucurbit crops. Gene duplication analysis indicated that dispersed duplication and whole genome duplication were the two primary causes of WOXgenes expansion. There were 24 and 129 gene pairs found within cucurbit crops, and between Cucumis sativusand other cucurbit crops, respectively. After gene duplication, all WOXgenes were subjected to substantial purifying selection pressure according to the selective pressure analysis. Functional divergence analysis revealed that ancient and intermediate clades may have descended from some essential amino acid sites rather than different evolution rate. Our research provides a comprehensive analysis of WOXgenes which will be helpful for further research into their function study in Cucurbitaceae plants.

Time difference of arrival (TDOA) is an essential technology in localization, communication, and navigation. However, it remains a significant challenge to increase the precision of TDOA in a low signal-to-noise ratio (SNR) situation. Therefore, this paper proposed a phase difference-reassigned synchro-squeezing transform (PDTR) algorithm to offer a precise TDOA estimator. Firstly, the partial derivative of the frequency variable of the short-term cross-power spectrum technique is employed to obtain two-dimensional delay information. Secondly, this spectrum can be reordered, utilizing the delay, and time–frequency points across the frequency axis can be accumulated to generate one-dimensional delay information. Finally, the delay associated with the most robust energy is selected to obtain the TDOA. Simulations and experiments are conducted to validate the efficacy and robustness of the algorithm comprehensively. Initially, simulation validation is executed, which confirms the algorithm's effectiveness. Subsequently, the algorithm's robustness in low-SNR environments is experimentally tested. The results demonstrate that the stability of the PDRT algorithm changes slowly as the SNR decreases from 0 to − 20 dB, but the stability of the comparable algorithm decreases sharply.

Among the inversion methods for airborne transient electromagnetic (ATEM) data, the hybrid inversion method integrates the iterative optimization framework with artificial neural networks (ANNs), ensuring inversion accuracy while enhancing the generalization capability of neural networks. However, this method faces challenges in terms of slow computation speeds due to its lower updated step length and the lack of consideration for electromagnetic response laws. Our method adopts a supervised descent method (SDM) framework to supervise the ANNs, obtaining a longer updated step length. On the basis of the SDM framework, we have considered the electromagnetic response laws and designed RNN-ResNet and 1-D-UNet networks to update the conductivity model, improving the computing speed. Through numerical ablation experiments, we validated the effectiveness of our proposed method and compared the inversion results with those obtained using the traditional hybrid method. Additionally, we conducted tests on bundle fringe distribution, inversion fitting loss, noise sensitivity, and inversion speed for both methods using measured data to evaluate their performance in practical applications. The experimental findings demonstrate that our method achieves the same level of inversion accuracy and generalization ability as the traditional hybrid method while enhancing inversion speed by up to 68.5%.

Armature-rail instantaneous current-carrying friction in electromagnetic launchers refers to a sliding electric-mechanical impact friction and transition-induced arc erosion on a millisecond time scale. To reveal the electric current (50 to 300 A) effects on friction behavior and wear mechanism, the instantaneous current-carrying friction tests were performed with Al 1060 and Brass H62. Given the short nonlinear friction-induced signals, the friction behavior, including the time-domain information and system state, was comprehensively analyzed via frictional sound pressure (FSP), recurrence plot (RP), and recurrence quantification analysis (RQA). The wear topography was observed, and characterized by the multifractal spectrum. Recurrence analyses demonstrate that as the current increases, the nonstationarity of the system state weakens, and the complexity and unpredictability enhance. Higher currents reduce the FSP amplitude, i.e., enhance the interfacial lubrication effect, but intensify electrical wear and surface roughness. This signifies a wear mechanism transition from abrasive wear and slight adhesive wear to arc ablation, fatigue wear, and severe adhesive wear. The widening spectrum width implies that the irregularity and fluctuation of the topography are enhanced with the current. RP patterns and RQA quantifiers correlate with the wear damage state. The results provide a reference for anti-wear design and online degradation tracking of the rail.

Tribological applications of polytetrafluoroethylene (PTFE) are often limited by technological complexity to overcome its poor wear resistance. Here, a PTFE/polyetheretherketone (PEEK) heterolayer (HL) was proposed and evaluated as a new solid lubrication solution. Pin-on-disk tribometry found the lowest friction coefficient (μ) of 0.031 and ultralow wear for the PEEK/HL under typical conditions. The friction coefficient of the HL surpasses those of the state-of-the-art polymeric coatings/composites by at least 200%, and approaches that of highly lubricated interfaces. Mechanistic investigations revealed multi-length physical and chemical heterogeneity of the HL that best facilitates a tribofilm with high subsurface stability and surface instability. The technological simplicity and robustness of the HL’s high lubricity make it a promising new type of solid lubrication toward greater reliability and longevity.

Distributed photovoltaic (PV) systems have constantly been the key to achieve a low-carbon economy in China. However, the development of Chinese distributed PV systems has failed to meet expectations because of their irrational profit and cost allocations. In this study, the methodology for calculating the levelized cost of energy (LCOE) for PV is thoroughly discussed to address this issue. A mixed-integer linear programming model is built to determine the optimal system operation strategy with a benefit analysis. An externality-corrected mathematical model based on Shapley value is established to allocate the cost of distributed PV systems in 15 Chinese cities between the government, utility grid and residents. Results show that (i) an inverse relationship exists between the LCOEs and solar radiation levels; (ii) the government and residents gain extra benefits from the utility grid through net metering policies, and the utility grid should be the highly subsidized participant; (iii) the percentage of cost assigned to the utility grid and government should increase with the expansion of battery bank to weaken the impact of demand response on increasing theoretical subsidies; and (iv) apart from the LCOE, the local residential electricity prices remarkably impact the subsidy calculation results.

For compensating the primary field coupling from the transmitting coil and the sensing coil, the bucking coil is often used to achieve pure secondary field for the helicopter transient electromagnetic (HTEM) system. Traditionally, the distributed capacitance of the bucking coil and the transmitting coil is ignored and pay few attentions to study it. In fact, it has very important influence on the turn-off current of the transmitter and the transient electromagnetic (TEM) field of the system. In this article, a novel distributed capacitance model of the HTEM coils is theoretically established at the first time, its effects on the turn-off current and the TEM field are analyzed in detail. It finds that the turn-off current in the transmitting coil and the bucking coil are not equal caused by the distributed capacitance although they are connected in series. The field experiments are completed and proved that the measured TEM fields agree very well with the simulated results based on the distributed capacitance model. This is very helpful to optimize the early-time TEM field and promote the shallow TEM data interpretation capability for the HTEM surveying.

The downsampling scheme of the Rayleigh backscattered (RBS) signal in heterodyne phase-sensitive optical time domain reflectometry ( $\Phi $ -OTDR) has been proven valid to reduce computational resource consumption, which is a critical issue in areas such as real-time monitoring applications. However, the influence of downsampling on the system’s sensing performances has not been explored. In this work, we established a model for the deterioration of noise caused by downsampling. The model reveals that the degradation of the power spectrum density (PSD) of the demodulated phase noise is attributed to the out-of-band noise aliasing into the beat frequency signal. Moreover, the model provides the PSD degradation at different downsampling frequencies. The upper bound of the PSD degradation has been verified in the experiment, without any antialiasing operations, which demonstrates good consistency with the theoretical and simulation predictions (the PSD deviation values are less than 0.5 dB). Additionally, we optimized the downsampling process using an antialiasing filter with a more matched filter characteristic, resulting in reduced noise PSD which still falls within the PSD degradation range. To the best of our knowledge, this is the first detailed analysis of the downsampling influence on $\Phi $ -OTDR sensing performance. It provides theoretical guidance for practical engineering applications of downsampling.

Understanding flow characteristics of fluid near rough contact is important for the design of fluid-based lubrication and basic of tribology physics. In this study, the spreading and seepage processes of anhydrous ethanol in the interface between glass and rough PDMS are observed by a homemade optical in-situtester. Digital image processing technology and numerical simulation software are adapted to identify and extract the topological properties of interface and thin fluid flow characteristics. Particular attention is paid to the dynamic evolution of the contact interface morphology under different stresses, the distribution of microchannels in the interface, the spreading characteristics of the fluid in contact interface, as well as the mechanical driving mechanism. Original surface morphology and the contact stress have a significant impact on the interface topography and the distribution of interfacial microchannels, which shows that the feature lengths of the microchannels, the spreading area and the spreading rate of the fluid are inversely proportional to the load. And the flow path of the fluid in the interface is mainly divided into three stages: along the wall of the island, generating liquid bridges, and moving from the tip side to the root side in the wedge-shaped channel. The main mechanical mechanism of liquid flow in the interface is the equilibrium between the capillary force that drives the liquid spreading and viscous resistance of solid wall to liquid. In addition, the phenomenon of “trapped air” occurs during the flow process due to the irregular characteristics of the microchannel. This study lays a certain theoretical foundation for the research of microscopic flow behavior of the liquid in the rough contact interface, the friction and lubrication of the mechanical system, and the sealing mechanism.

Realizing sensitive and efficient detection of biomolecules and drug molecules is of great significance. Among the detection methods that have been proposed, electrochemical sensing is favored for its outstanding advantages such as simple operation, low cost, fast response and high sensitivity. The unique structure and properties of surfactants have led to a wide range of applications in the field of electrochemical sensors and biosensors for biomolecules and drug molecules. Through the comparative analysis of reported works, this paper summarizes the application modes of surfactants in electrochemical sensors and biosensors for biomolecules and drug molecules, explores the possible electrocatalytic mechanism of their action, and looks forward to the development trend of their applications. This review is expected to provide some new ideas for subsequent related research work.

Digital twin is currently undergoing a significant transformation from the conceptual and theoretical research phase to the implementation and application phase. However, a universally adaptable research and development platform for digital twin is critically needed to meet the development requirements. Specifically, a publicly accessible simulation, testing, and validation platform which can support digital twin model building, data processing, algorithm design, configuration, etc., is urgently required for researchers. Furthermore, for developers from the industry, a low-code development platform that can offer a customizable suite of functions such as model creation, data management, protocol configuration, and visualization is urgently needed. Meanwhile, for enterprise users, there is a lack of an application management platform that can be configured and migrated for various application scenarios, functions, and modes. Therefore, based on the system research of digital twin theories and key technologies by the authors (such as the five-dimension digital twin model, digital twin modeling and digital twin data theory, digital twin standards, and so on), a digital twin software platform reference architecture, namely makeTwin, is proposed and designed, as well as its ten core functions. The workflow of the makeTwin and the interaction mechanisms among its core functions are described. Finally, a digital twin application system for a chemical fiber textile shop floor (CFTS) which was developed according to makeTwin, is introduced, which validates the proposed reference architecture.

Compensated pulse alternators (CPAs) are widely used as a kind of high-power pulse power supply, in which the compensating components can reduce the transient impedance of armature winding, to obtain current pulses with high peak values. In this article, a differential brushless doubly-fed pulsed alternator (BDPA) is proposed, and two sets of windings in the stator of BDPA are decoupled from each other, and each of them is coupled to the self-closing rotor winding. So, when the armature winding is discharged, a compensating current is generated in the rotor and excitation windings, which can increase the discharging current of the armature winding. Due to the absence of brushes, the brushless doubly-fed motor has higher reliability, but the heat generation of an iron core pulse alternator is higher than that of an air core pulse alternator, which may damage the windings in motor, especially brushless doubly-fed motors with three sets of windings. For this reason, the operation mode of periodic intermittent excitation was chosen. The excitation power supply is switched on only when continuous pulse discharges are performed and is switched off for the rest of the time. In this article, a lumped parameter thermal network (LPTN) model is established for a brushless doubly-fed pulse generator, steady-state and transient temperature rises of BDPA are analyzed using this model and compared with the calculation results of finite elements to verify the validity of LPTN model.

The rural energy reform, which is caused by the rapid development of renewable energy, will significantly impact rural residents’ energy use behaviors. The willingness of rural residents to adjust energy use is critical for realizing the rural energy reform. In this study, a questionnaire survey was implemented to ask residents to consider three virtual electricity pricing scenarios and investigate residents’ willingness to adjust energy use behaviors. Scenario PVR (Peak–valley rate) involved applying the peak–valley rate electricity price. Scenario PVS (Photovoltaic systems) involved building photovoltaic systems. Scenario OFR (Original flat-rate) involved maintaining the original flat-rate electricity price. The extended theory of planned behavior was then used to conduct a multi-group analysis to assess the factors influencing rural residents’ willingness to adjust energy use. The field research results for 533 rural households in the Guanzhong Plain in China indicated that (1) The proportions of rural residents choosing Scenario PVR, Scenario PVS, and Scenario OFR were 45.22%, 22.89%, and 31.89%, respectively. (2) The rural residents choosing Scenario PVS and Scenario OFR showed the strongest and the weakest willingness to adjust energy use, respectively. (3) Social capital significantly affected residents’ attitude and perceived behavioral control about their willingness to adjust energy use; however, there is a discrepancy in the impact mechanism for different residents. (4) For rural residents choosing Scenario PVS, their willingness to adjust energy use was significantly affected by policies and regulations; the impact was less significant for residents choosing the other scenarios.

Lithium–sulfur (Li–S) batteries reveal unequaled theoretical capacity and higher energy density compared to commercial Li-ion batteries. Still, the commercialized application process of Li–S battery is impeded by low utilization of sulfur and capacity fading from the “shuttle effect” and sluggish lithium polysulfides (LiPSs) redox conversion kinetics, especially for the battery with high areal sulfur loading and lean electrolyte. Herein, nitrogen-doped carbon nanoplates embedded with ultrafine TiO2–TiN heterojunctions (TiON@CNPs) are prepared by copyrolysis of NH2-MIL-125 nanoplates with melamine, serving as the multifunctional interlayer for LiPSs blocking, efficient conversion and fast Li2S nucleation. In this design, the LiPSs could be physically blocked by the N-doped carbon nanoplates and ultrafine TiO2–TiN heterostructures via chemical interaction and then subsequently converted to Li2S with enhanced kinetics and electrochemical efficiency and nucleation on the surface of ultrafine TiO2–TiN heterostructures. Meanwhile, the porous nanoplate structure of the carbon skeleton could also shorten the Li+diffusion path and afford more electrochemical active sites for Li2S/S uniform deposition. As a consequence, the cell with TiON@CNPs modified separator achieves a high capacity retention of 83.2% (1147 mAh·g–1at 0.2 C) after 300 cycles, a preferred rate performance of 908 mAh·g–1at 4.0 C, and a low capacity decaying of 0.026% per cycle at 1 C over 1200 cycles. Remarkably, the cathode with sulfur loading of 4.5 mg·cm–2achieves a reversible capacity of 4.28 mAh·cm–2after 200 cycles, demonstrating a potential for future application in Li–S batteries.

For the 3-D terahertz (THz) holographic imaging, this work proposes an extended phase-shift migration (PSM) reconstruction algorithm based on multiple-input-multiple-output (MIMO) array with an orthogonal synthetic aperture (SA). For this MIMO-SA-based imaging mechanism, the accurate expression of the signal spatial spectrum can also be obtained by utilizing the method of stationary phase (MSP). Meanwhile, the analytical expression of the reconstructed 3-D point-spread function (PSF) for target under the illumination of MIMO-SA-based THz Gaussian beam is derived to provide the theoretical spatial resolutions quantitatively. A serial of simulation results with fairly good agreement were given to verify the accuracy of the proposed MIMO-SA-based PSM reconstruction algorithm. Meanwhile, due to the PSM’s characteristic of phase shift compensation along the range direction, the image reconstruction process can also be implemented and accelerated by a GPU solution. Finally, two types of MIMO-SA-based prototype imagers are applied for the proof-of-principle experiments. The first prototype imager is configured with one transmitter and two receivers in 0.3-THz band. The MIMO linear array including arbitrary number of transmitters/receivers can be realized by controlling their positions in a low-cost way with the help of the $x$ -axis of a 2-D scanner. The second prototype imager is configured with eight transmitters and eight receivers in 0.2-THz band. The experimental results from the two prototype imagers can validate the effectiveness on image reconstruction quality.

The impact of droplets on particles involves a wide range of complex phenomena and mechanisms, including bubble nucleation, crater formation, fluidization, and more intricate changes in the boiling regime when impacting superheated particles. In this study, we focus on droplet impact behavior on superheated laminar particles at various temperatures and define six typical characteristic patterns of a single droplet impact on superheated laminar particles, including film evaporation, bubbly boiling, immersion boiling, sputter boiling, transition boiling, and film boiling. It is worth noting that the variations of inertial force FIcaused by gravity, the capillary force FCgenerated by the pores of the droplets, and the dewetting force by the vapor phase FVare the main contributors to different evaporation regimes. Interestingly, we find that the Leidenfrost point (LFP) of droplets on the laminar superheated particles decreases with particle size, which is related to the effect of the pore space generated between the laminar particles. Finally, the effect of temperature, particle size, and Weber number (We) on the dynamic behavior of droplet impact is revealed. Experimental results show that the instantaneous diameter of droplets is inversely proportional to the change of height, with different patterns of maximum spreading diameter and maximum bounce height at different particle sizes, while the maximum spreading velocity and maximum bounce velocity are independent of particle size. We believe the present work would provide a broader knowledge and comprehension of the droplet impact on heated particles and promote the development of the safety and productivity of industrial processes such as fluid catalytic cracking, spray drying, and spray cooling.

With the continuous development of the logistics industry, it is difficult to ensure the safety of the goods by traditional means of transportation. “Blockchain + ” has gradually become a wave of financial technology sweeping the world. However, the application of any technology is not automatically realized. It needs to provide portrait guidance technology in related fields. Its application research in supply chain finance is not only in line with national policies. With the support of the government, the practical problems in the development of the industry can be solved more effectively. The thoughts and suggestions made from the perspective of industry organizers have direct guiding significance for this article, especially the industry. The application of Internet of things technology in logistics can better meet the customer’s supervision of logistics process. The purpose of this study is to build a supply chain financial logistics supervision system based on Internet of things technology, and analyze its role. In this study, intelligent sensor is used as an important means in logistics supervision. Firstly, goods are classified effectively in the dynamic resource allocation algorithm under limited bandwidth, and then the goods are scanned by RFID technology, and then tracked and supervised in real time. This research is simulated on the MATLAB software of stado distributed database server. The results show that the static algorithm with 5.2 Hz is far less than the 14 Hz of the dynamic allocation algorithm in this study. The total es value of the operational risk based on the Internet of things technology is 303.3446 million yuan, which is 6962.65 less than that of the traditional mode operation This shows that the logistics supervision system based on the Internet of things technology effectively reduces the operational risk of the supply chain fund, and the distribution detection accuracy of the supervision system is high. The conclusion is that the supply chain logistics monitoring system based on Internet of things technology is more effective than traditional logistics mode, the goods are safer and the risk is smaller. This research contributes to the intelligent development of logistics supervision system.

Regulation over the generation of the Leidenfrost phenomenon in liquids is vitally important in a cutting fluid/tool system, with benefits ranging from optimizing the heat transfer efficiency to improving the machining performance. However, realizing the influence mechanism of liquid boiling at various temperatures still faces enormous challenges. Herein, we report a kind of microgrooved tool surface by laser ablation, which could obviously increase both the static and dynamic Leidenfrost point of cutting fluid by adjusting the surface roughness (Sa). The physical mechanism that delays the Leidenfrost effect is primarily due to the ability of the designed microgroove surface to store and release vapor during droplet boiling so that the heated surface requires higher temperatures to generate sufficient vapor to suspend the droplet. We also find six typical impact regimes of cutting fluid under various contact temperatures; it is worth noting that Sahas a great influence on the transform threshold among six impact regimes, and the likelihood that a droplet will enter the Leidenfrost regime decreases with increasing Sa. In addition, the synergistic effect of Saand tool temperature on the droplet kinetics of cutting droplets is investigated, and the relationship between the maximum rebound height and the dynamic Leidenfrost point is correlated for the first time. Significantly, cooling experiments on the heated microgrooved surface are performed and demonstrate that it is effective to improve the heat dissipation ability of cutting fluid by delaying the Leidenfrost effect on the microgrooved heated surface.

ABSTRACTIn this paper, an advanced signal processing algorithm based on low-rank sparse representation is proposed to enhance the vital signal in life detection radar applications. The pre-processed echo signal can be decomposed into low-rank, sparse, and noisy parts, where the sparse part is the vital signal. A non-convex regularization method is adopted to obtain the required components, and the approximate solution method is used to accelerate the calculation to meet real-time requirements. Simulated and experimental results show that the proposed algorithm outperforms existing methods in terms of output signal-to-noise ratio (SNR).

Understanding the impacts of atmospheric nutrient deposition is very important for forest soil greenhouse gas (GHG) emissions and predicting future trends. While nutrient deposition is known to affect soil properties and GHG emissions, the roles of soil aggregate sizes and their distributions in affecting GHG emissions remain largely unknown. Here, the effects of N (0, 50, or 100 kg N ha−1year−1), P (0 or 50 kg N ha−1year−1), and soil aggregate size (< 0.25 mm, 0.25–0.5 mm, 0.5–1 mm, 1–2 mm) on soil CO2and N2O emissions were studied through a 7-year continuous N and P addition experiment in a 12-year-old Chinese fir plantation. Soil CO2emission rates, N2O emission rates, net N mineralization rate, net nitrification rate, and soil properties were measured in the laboratory soil incubation experiments. Soil chemical properties varied with different aggregate size, and net soil N mineralization rate increased significantly with aggregate size (F= 16.7, P< 0.0001). Smaller aggregates had higher peak (F= 74.9, P< 0.0001) and cumulative CO2emissions. Soil N2O emissions increased with N addition (F= 18.5, P< 0.0001) but not with aggregate size (F= 0.1, P= 0.9843). Compared with control treatment, higher N addition treatment increased both peak and cumulative N2O emissions, while soil N2O emissions from soil with lower N addition treatment did not differ from control treatment. Our results show that soil aggregate size interacts with N and P addition to alter GHG emissions. N2O and CO2responded differently to N, P, and aggregate size. Higher N addition alone caused the largest cumulative emissions of N2O (8.90 ± 2.67 ng g−1), while cumulative CO2emissions were only affected by particle size (peak of 81.66 ± 3.02 μg g−1with < 0.25 mm particle size). The effects of N, P, and related changes in aggregate size on GHG emissions should be considered in future studies on soil GHG budgets and mitigation.

The characteristics of surface morphology markedly affect the tribological properties of contact interface such as lubrication and seal performance. In present work, the synergetic effect of surface connectivity and some three-dimensional topography parameters (ISO 25178) on the friction characteristics of a sliding contact interface, based on mathematical morphology and reciprocating linear tribotesting, is explored. The results indicate that the friction properties of sliding contact interface was significantly affected by the variation of surface connectivity. The increase in connectivity index would improve the relative contact area on the isotropic surfaces and affect the distribution and storage characteristics of the fluid, while this enhancement would be blocked on the anisotropic surface and the variation of connectivity index is obviously nonlinear with a shocking feature. The friction tests confirm that the friction coefficient of sliding contact interface decreases with the increasing surface connectivity index, which is mainly related to the enhancement of lubricant storage and flow in each void region and improving the lubrication behavior.Furthermore, the same variation law is applicable to the relationship between the functional morphology parameters and the friction property. The increasing Vvvand Sku, would contribute to a lower friction coefficient at the interface. Our work provides deep insights into regulating the tribological property of contact interfaces through surface topography control.

The transient electromagnetic (TEM) method utilizes artificial transmitters and measures electromagnetic (EM) responses to reveal the resistivity information of the subsurface. The current waveform of transmitters has nonnegligible effects on induced fields. Therefore, 3-D TEM forward modeling algorithms need the capability of simulating arbitrary waveforms to obtain accurate responses. In time-stepping-based 3-D TEM forward modeling, the source term (ST) approach is frequently used, which employs the source current density to model the waveform variation during time-stepping. The ST approach, however, requires fine-time discretization to describe complex waveforms, which could significantly raise the computational cost. We present a robust convolution (Conv) approach that computes the convolution between the time derivative of the waveform and the step-off response to incorporate the waveform effects in 3-D TEM modeling. The Conv approach does not discretize the waveform using time steps. Hence, it is advantageous when modeling full-waveform cases. The developed algorithm is based on the finite-element (FE) method using unstructured grids and the implicit backward Euler approach. Both galvanic and inductive transmitters are incorporated. Ground and airborne TEM surveys are tested using an actual airborne TEM waveform, a full waveform of the $2^{(n)}$ -sequence pseudorandom signal, and various synthetic waveforms. Accuracy is validated against the 1-D and 3-D solutions of published studies. The ST and Conv approaches are compared. Synthetic examples show that the latter approach simplifies the waveform incorporation in TEM modeling and substantially improves time-stepping efficiency without sacrificing accuracy.

The 3-D object detector usually uses a framework similar to 2-D detection and benefits from the advancements of 2-D detection tasks. In these frameworks, it is necessary to make the unstructured, sparse point cloud features into dense grids to be compatible with popular 2-D operators, such as convolution and transformers, which also causes extra computational costs. In this article, we propose a simple and efficient Fully Sparse TRansformer (FSTR) for light detection and ranging (LiDAR)-based 3-D object detection, which is able to combine with state-of-the-art (SOTA) sparse backbones to form a fully sparse, end-to-end, simple, and efficient detection framework. FSTR uses the sparse voxel feature from the sparse backbone as the input token without any custom operators. Furthermore, we introduce the dynamic queries (DQs) to provide a priori location and context of the foreground for the decoder and drop the high-confidence background tokens to further reduce redundant computations. We propose Gaussian denoising queries to speed up the decoder training and make it more adaptable to the distribution of sparse voxel features. Extensive experiments on the nuScenes benchmark and the Argoverse2 (AV2) benchmark validate the effectiveness of the proposed method. FSTR outperforms all LiDAR real-time methods by 69.5 mean average precision (mAP) and 72.9 nuScenes detection score (NDS) on the official benchmark of nuScenes dataset. On the long-range detection benchmark AV2, the proposed method achieves a new SOTA performance of 39.9 mAP, which outperforms the existing LiDAR detectors, even the LiDAR–camera detectors by a large margin (+9.4 and +7.5 mAP), showing the great advantage of the proposed method for long-range detection.

Submanifold convolution is widely used in 3-D detection. However, it brings different receptive fields to voxels due to the nonuniform distribution in Light Detection and Ranging (LiDAR) point clouds, resulting in degradation of the feature extraction ability for distant voxels and the performance of detectors. We propose a solution, adaptive receptive field aggregation (ARFA) network, an end-to-end two-stage LiDAR 3-D object detection architecture. ARFA searches the top- ${K}$ nearest neighbors (KNNs) to adaptively adjust the receptive field of sparse voxels, followed by a self-attention aggregation (SA) module with density feature embedding (DE) to aggregate the semantic information in the receptive field. In order to further strengthen the detection performance for small objects, we also propose an upsampling bird’s eyes view (U-BEV) backbone and a Intersection over Union (IoU)-aware head to enhance the quality of the proposals and rectify the confidence of the predicted bounding boxes. ARFA outperforms the state-of-the-art methods on the Waymo Open dataset and achieves competitive results on the popular KITTI dataset.

This work proposes a novel terahertz (THz) 3-D imaging system that combines the Gaussian-fan-beam scanning and multiple-input–multiple-output (MIMO) array to create a high frame rate, large field of view (FoV), and high-resolution radar images for continuously noncooperative on-the-move personnel security screening. The main novelty of the present system is that the 3-D THz focused images of the noncooperative on-the-move whole body can be created in real time when the persons are illuminated by scanning the MIMO-array-based Gaussian fan beam. In this article, the 3-D image is composed of a serial of 2-D slice images that are reconstructed by the proposed MIMO-array-based phase shift migration algorithm under the illumination of the THz Gaussian fan beam. Meanwhile, an analytical expression of the reconstructed point-spread function is derived to provide the theoretical spatial resolutions quantitatively. One prototype imager was designed for the proof-of-principle experiments in the 0.2 THz band, and the image reconstruction process is implemented in real time by the proposed hybrid central processing unit (CPU)–graphics processing unit (GPU) solution. At this stage, an FoV of 500 cm $\times200$ cm at a 10 m distance costs less than 0.1 s for 3-D imaging during 10 Hz mechanical Gaussian-fan-beam scanning. Finally, both simulation and experimental results validate the effectiveness of the proposed imaging algorithm on image reconstruction quality, including resolution, frame rate, and FoV.

We report a cathodic reduction-dominated electrochemical approach for the hydrogenation of azobenzenes in dichloromethane. With cheap and readily available N,N-diisopropylethylamine as a catalytic mediator, the reaction proceeded smoothly in a simple undivided cell under constant-current electrolysis. A series of azobenzenes were successfully reduced to the corresponding hydrazobenzenes in moderate to high yields at room temperature. Preliminarily mechanistic studies indicate that solvent dichloromethane acts as a hydrogen source. The use of a common solvent as a hydrogen source, no need for stoichiometric mediators or metallic reductants, and mild conditions make this work a more straightforward and sustainable protocol for hydrogenation of azobenzenes.

Adiponectin (AdipoQ), an adipokine secreted by adipocytes, has been reported to exist widely in various cell types and tissues, including the adenohypophysis of chickens. However, the molecular mechanism by which AdipoQ regulates the function of chicken adenohypophysis remains elusive. In this study, we investigated the effects of AdipoQ on proliferation, apoptosis, secretion of related hormones (FSH, LH, TSH, GH, PRL and ACTH) and expression of related genes (FSHβ, LHβ, GnRHR, TSHβ, GH, PRLand ACTH) in primary adenohypophysis cells of chickens by using real-time fluorescent quantitative PCR (RT-qPCR), cell counting kit-8 (CCK-8), flow cytometry, enzyme-linked immunosorbent assay (ELISA) and Western blot (WB) assays. Our results showed that AdipoQ promoted the proliferation of chicken primary adenohypophysis cells, up-regulated the mRNA expression of proliferation-related genes CDK1, PCNA, CCND1and P21(P< 0.05), as well as the increased protein expression of CDK1 and PCNA (P< 0.05). Furthermore, AdipoQ inhibited apoptosis of chicken primary adenohypophysis cells, resulting in down-regulation of pro-apoptotic genes Caspase3, Fas, and FasLmRNA expression, and decreased Caspase3 protein expression (P< 0.05). Moreover, there was an up-regulation of anti-apoptotic gene Bcl2 mRNA and protein expression (P< 0.05). Additionally, AdipoQ suppressed the secretion of FSH, LH, TSH, GH, PRL, and ACTH (P< 0.05), as well as the mRNA expression levels of related genes (P< 0.05). Treatment with AdipoRon (a synthetic substitute for AdipoQ) and co-treatment with RNA interference targeting AdipoQ receptors 1/2 (AdipoR1/2)had no effect on the secretion of FSH, LH, TSH, GH, PRL, and ACTH, as well as the mRNA expression levels of the related genes. This suggests that AdipoQ's regulation of hormone secretion and related gene expression is mediated by the AdipoR1/2 signaling axis. Importantly, we further demonstrated that the mechanism of AdipoQ on FSH, LH, TSH and GH secretion is realized through AMPK signaling pathway. In conclusion, we have revealed, for the first time the molecular mechanism by which AdipoQ regulates hormone secretion in chicken primary adenohypophysis cells.

Utilizing the self-collimation effect in two-dimensional (2D) sonic crystals (SCs), we have proposed an acoustic notch filter which is composed of two perfect mirrors and a beam splitter. Numerical simulation shows that by properly designing the inside structure of the 2D SC, the self-collimated acoustic waves with a desired frequency can be trapped between the two mirrors, realizing the notch filtering function. Moreover, the frequency and bandwidth of the notch filter can be arbitrarily adjusted by changing the parameters of the internel structure, in a considerably broad band. Potential applications include acoustic communication and acoustic signal processing, especially for underwater circumstances.

Nodular fasciitis (NF) has a low incidence, many classification subtypes and large histological variations. We describe a 17-month-old child who presented with a mass in the right cavity of auricular concha that was successfully cured by 2 procedures. In pediatric patients with fibroproliferative lesions, the possibility of NF should be excluded to avoid misdiagnosis and overtreatment.

Intracellular bacterial infections pose a serious threat to public health. Macrophages are a heterogeneous population of immune cells that play a vital role in intracellular bacterial infection. However, bacteria that survive inside macrophages could subvert the cell signaling and eventually reduce the antimicrobial activity of macrophages. Herein, dual pH-responsive polymer (poly[(3-phenylprop-2-ene-1,1-diyl)bis(oxy)bis(enthane-2,1-diyl)diacrylate-co-N-aminoethylpiperazine] (PCA)) nanoparticles were developed to clear intracellular bacteria by activating macrophages and destructing bacterial walls. The presence of acid-labile acetal linkages and tertiary amine groups in the polymer’s backbone endow hyperbranched PCA dual pH-response activity that shows acid-induced positive charge increase and cinnamaldehyde release properties. The biodegraded PCA nanoparticles could significantly inhibit the growth of bacteria by damaging the bacterial walls. Meanwhile, PCA nanoparticles could uptake by macrophages, generate reactive oxygen species (ROS), and remodel the immune response by upregulating M1 polarization, leading to the reinforced antimicrobial capacity. Furthermore, PCA nanoparticles could promote bacteria-infected wound healing in vivo. Therefore, these dual pH-responsive PCA nanoparticles enabling bacteria-killing and macrophage activation provide a novel outlook for treating intracellular infection.

Several leukocyte to high-density lipoprotein cholesterol (HDL-C) ratios, including monocyte to HDL-C ratio (MHR), neutrophil to HDL-C ratio (NHR) and lymphocyte to HDL-C ratio (LHR), have been proposed as novel inflammatory indicators. We performed a cross-sectional study to investigate the relationships between these leukocyte to HDL-C ratios and coronary artery disease (CAD) in patients with chest pain with controlled low-density lipoprotein cholesterol (LDL-C). A total of 3482 patients with chest pain with LDL-C <1.8?mmol/L were enrolled. We evaluated the relationships between MHR, NHR, LHR and HDL-C and the occurrence of CAD as well as severe stenosis. We found that in patients with chest pain, higher MHR (adjusted OR=2.83, 95%?CI 1.61 to 4.99, p<0.001) and NHR (adjusted OR=1.08, 95%?CI 1.04 to 1.13, p<0.001), as well as lower HDL-C (adjusted OR=0.53, 95%?CI 0.36 to 0.78, p=0.001), but not higher LHR (adjusted OR=1.06, 95%?CI 0.94 to 1.20, p=0.341), had a stronger association with the occurrence of CAD. Moreover, unlike LHR (adjusted OR=1.02, 95%?CI 0.93 to 1.13, p=0.654), higher MHR (adjusted OR=2.10, 95%?CI 1.43 to 3.07, p<0.001) and NHR (adjusted OR=1.06, 95%?CI 1.04 to 1.09, p<0.001) and lower HDL-C (adjusted OR=0.38, 95%?CI 0.26 to 0.56, p<0.001) were risk factors for severe stenosis. A receiver operating characteristic curve analysis exhibited comparable abilities between MHR and NHR in predicting the presence and severity of CAD. In conclusion, even though patients with chest pain have achieved LDL-C <1.8?mmol/L, the inflammatory indicators MHR and NHR maintained their predictive abilities and remained associated with the occurrence and severity of CAD.