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Reducing the defect density and improving the performance of selective laser melting-forming parts are significant for the development of selective laser melting (a great potential powder additive manufacturing method). Therefore, many methods like layer-by-layer laser remelting have been applied in the selective laser melting process. To investigate the influence of the layer-by-layer laser remelting process on the selective laser melting 316 L SS specimens, a three-dimension mesoscale remelting numerical simulation model in the single powder layer is established, and the microstructure and performance (surface quality, mechanical properties) are measured and analyzed with the different number of layer-by-layer laser remelting. The numerical simulation results show that the remelting process can effectively inhibit the defect. Nerversless, when the number of remelting is large, the over-melting phenomenon occurs, which is harmful to surface quality on the remelting surface. The experimental results also show that surface roughness, microhardness, ultimate strength, and strain can be effectively improved by controlling remelting times. [ABSTRACT FROM AUTHOR]

Selective laser melting (SLM) is a popular additive manufacturing technique for metal material. Microstructure and defects of fabricated parts by SLM are closely associated with double scanning track. In this study, the single/double track formation simulation of 316L stainless steel was established to study the influence of process parameters on the forming and the defects during the SLM process. In addition, the impact of melt pool flow on single/double track forming and defects was analyzed. Experiments verified the numerical simulation. Results show that the volume energy density (VED) has significant influence on the formation and defects of SLM, and the optimized volume energy density (VED) range is obtained by numerical simulation and experiments. [ABSTRACT FROM AUTHOR]

The space distributed-order constitution relationship is firstly formulated to study the flow and heat transfer in the boundary layer. The distributed-order boundary layer equations are derived and approximated by a multi-space fractional order ones, which are then solved by the implicit difference schemes. By comparing the analytical solutions of special boundary conditions, the validity of the present numerical method is examined. Then, the stability and convergence of the implicit finite difference scheme are analysed systematically. Finally, we present two practical examples to illustrate the effectiveness of our numerical method. Furthermore, the numerical technique in this study can be extended to others distributed-order boundary layer models. [ABSTRACT FROM AUTHOR]

Background Intense stresses caused by high-altitude environments may result in noticeable genetic adaptions in native species. Studies of genetic adaptations to high elevations have been largely limited to terrestrial animals. How fish adapt to high-elevation environments is largely unknown. Triplophysa bleekeri , an endemic fish inhabiting high-altitude regions, is an excellent model to investigate the genetic mechanisms of adaptation to the local environment. Here, we assembled a chromosomal genome sequence of T. bleekeri , with a size of ∼628 Mb (contig and scaffold N50 of 3.1 and 22.9 Mb, respectively). We investigated the origin and environmental adaptation of T. bleekeri based on 21,198 protein-coding genes in the genome. Results Compared with fish species living at low altitudes, gene families associated with lipid metabolism and immune response were significantly expanded in the T. bleekeri genome. Genes involved in DNA repair exhibit positive selection for T. bleekeri, Triplophysa siluroides , and Triplophysa tibetana , indicating that adaptive convergence in Triplophysa species occurred at the positively selected genes. We also analyzed whole-genome variants among samples from 3 populations. The results showed that populations separated by geological and artificial barriers exhibited obvious differences in genetic structures, indicating that gene flow is restricted between populations. Conclusions These results will help us expand our understanding of environmental adaptation and genetic diversity of T. bleekeri and provide valuable genetic resources for future studies on the evolution and conservation of high-altitude fish species such as T. bleekeri. [ABSTRACT FROM AUTHOR]

• Double fractional Maxwell model and generalized Fourier's law are introduced to the constitutive relationships. • Reliability of numerical solutions is proved by constructing the exact solutions with the source items. • Convergence order of numerical schemes can achieve the expected first order. • Double fractional Maxwell model presents solid-like or fluid-like behavior. This paper presents research on the fractional boundary layer flow and heat transfer over a stretching sheet with variable thickness. Based on the Caputo operators, the double fractional Maxwell model and generalized Fourier's law are introduced to the constitutive relationships. The governing equations are solved numerically by utilizing the finite difference method. The effects of fractional parameters on the velocity and temperature field are analyzed. The results indicate that the larger is the fractional stress parameter, the stronger is the elastic characteristic. However, fluids show viscous fluid-like behavior for a larger value of fractional strain parameter. Moreover, the numerical solutions are in good agreement with the exact solution and the convergence order can achieve the expected first order. The numerical method in this study is reliable and can be extended to other fractional boundary layer problems over a variable thickness sheet. [ABSTRACT FROM AUTHOR]

A double fractional Maxwell model is developed to study the boundary layer flow of viscoelastic MHD fluid over a stretching sheet. Based on the Caputo operators, fractional boundary layer equations are solved numerically by the finite difference method. The effects of stress fractional parameter α and strain fractional parameter β on the flow characteristics are analyzed. It is worth mentioning that the viscoelastic MHD fluid described by the double fractional Maxwell model presents solid-like behavior or fluid-like behavior for different α and β , which agree well with the classical work of Friedrich. The results indicate that the greater the α is, the stronger the elastic characteristic and the oscillating phenomenon is. However, as the β decreasing, the fluid represents viscous fluid-like behavior. [ABSTRACT FROM AUTHOR]

Abstract Renal artery stenosis (RAS) hypertension is a common type of secondary hypertension. This paper aimed to explore how unilateral renal artery stenosis (Uni-RAS) and bilateral renal artery stenosis (Bi-RAS) caused renovascular hypertension with the fluid-structure interaction (FSI) method. Based on a real RAS model, 20 ideal models with different stenosis degrees were established by modifying the stenosis segment. The hemodynamic parameters at different degrees of stenosis, mass flow rate (MFR), pressure drop (PD), fractional flow reserve (FFR), oscillatory shear index (OSI), and relative residence time (RRT), were numerically calculated by the computational fluid dynamics (CFD) method. The numerical results showed that RAS caused the decrease of MFR, and the increase of PD and the proportion of high OSI and high RRT. In the case of RAS, it could not be regarded as a reference indicator for causing renovascular hypertension that the value of FFR was greater than 0.9. In addition, the results of the statistical analysis indicated that Uni-RAS and Bi-RAS were statistically different for MFR, PD and the proportion of high RRT. [ABSTRACT FROM AUTHOR]

Lie-group is introduced for studying boundary layer flow and heat transfer of fractional viscoelastic MHD fluid over a stretching sheet. Fractional boundary layer equations, based on Riemann–Liouville operators, are reduced and solved numerically by Grünwald scheme approximation. Results show that the skin friction and thermal conductivity are strongly affected by magnetic field parameter, fractional derivative and wall stretching exponent. The bigger of the fractional order derivative leads to the faster velocity of viscoelastic fluids near the plate but not to hold near the outer flow. Skin friction increases with increase of magnetic field parameter M , while the heat transfer decreases. For wall stretching exponent parameter β = 1 . 0 , the velocity profile decreases with the increase of similarity variable η . However, for β = − 1 . 5 , the velocity profile increases initially and then decreases afterwards with the biggest velocity at the interior of boundary layer. [ABSTRACT FROM AUTHOR]

Plant pectin methyl-esterase (PME) and PME inhibitor (PMEI) belong to large gene families whose members are proposed to be widely involved in growth, development, and stress responses; however, the biological functions of most PMEs and PMEIs have not been characterized. In this study, we studied the roles of CbPMEI1 , a cold-induced pectin methyl-esterase inhibitor (PMEI) gene from Chorispora bungeana , under freezing and salt stress. The putative CbPMEI1 peptide shares highest similarity (83%) with AT5G62360 (PMEI13) of Arabidopsis. Overexpression of either CbPMEI1 or PMEI13 in Arabidopsis decreased tissue PME activity and enhanced the degree of methoxylation of cell wall pectins, indicating that both genes encode functional PMEIs. CbPMEI1 and PMEI13 were induced by cold but repressed by salt stress and abscisic acid, suggesting distinct roles of the genes in freezing and salt stress tolerance. Interestingly, transgenic Arabidopsis plants overexpressing CbPMEI1 or PMEI13 showed decreased freezing tolerance, as indicated by survival and electrolyte leakage assays. On the other hand, the salt tolerance of transgenic plants was increased, showing higher rates of germination, root growth, and survival under salinity conditions as compared with non-transgenic wild-type plants. Although the transgenic plants were freezing-sensitive, they showed longer roots than wild-type plants under cold conditions, suggesting a role of PMEs in balancing the trade-off between freezing tolerance and growth. Thus, our study indicates that CbPMEI1 and PMEI13 are involved in root growth regulation under cold and salt stresses, and suggests that PMEIs may be potential targets for genetic engineering aimed to improve fitness of plants under stress conditions. [ABSTRACT FROM AUTHOR]

The distributed-order model is equivalent to weighting the fractional-order model on a given interval. In this paper, a double time-distributed order Maxwell model is developed and formulated to study the characteristics of a start-up pipe flow. The numerical solution of the distributed-order governing equation is obtained by the finite difference method. In order to test the convergence of numerical solutions, the truncation error of the proposed numerical method be calculated. The characteristics of the flow and the effects of fractional parameters and weight functions on the velocity distribution are discussed in detail. By comparing the velocity distribution diagrams, it can be inferred that the distributed-order model controlled by the weight function can describe the memory and elastic properties of fluid more flexibly. [ABSTRACT FROM AUTHOR]

The FIGARCH model has received wide attention due to its ability to capture the features of volatility long-memory persistence and clustering. The classical FIGARCH model is based on the difference scheme of Grünwald–Letnikov fractional operators. This paper introduces the new class of FIGARCH processes for improving time-varying volatility predictions. Firstly, a novel FIGARCH model based on the Caputo fractional operators (FIGARCH-C model for short) is proposed. Secondly, a quasi-maximum likelihood estimation (QMLE) is used to estimate the parameters of the FIGARCH-C(1, d, 1), the FIGARCH(1, d, 1) and GARCH(1, 1) models. Finally, we apply the three models to Brent crude oil and S&P 500 returns and provide the comparison results of the three models. The results show that the FIGARCH and FIGARCH-C models outperformed the GARCH model in capturing the long memory in volatility. It is also found that the FIGARCH-C model is more sensitive to capture the change in the volatile period. • A novel FIGARCH model based on the Caputo fractional operators is proposed. • A quasi-maximum likelihood estimation was used to estimate the parameters. • The FIGARCH-C model behaves most accurately in the estimation and forecasting. [ABSTRACT FROM AUTHOR]

Thioredoxin is a ubiquitous dithiol oxidoreductase found in many organisms and involved in numerous biochemical processes. Human thioredoxin-like protein (hTRXL) is differentially expressed at different development stages of human fetal cerebrum and belongs to an expanding family of thioredoxins. We have solved the crystal structure of the recombinant N-terminal catalytic domain (hTRXL-N) of hTRXL in its oxidized form at 2.2-Å resolution. Although this domain shares a similar three-dimensional structure with human thioredoxin (hTRX), a unique feature of hTRXL-N is the large number of positively charged residues distributed around the active site, which has been implicated in substrate specificity. Furthermore, the hTRXL-N crystal structure is monomeric while hTRX is dimeric in its four crystal structures (reduced, oxidized, C73S and C32S/C35S mutants) reported to date. As dimerization is the key regulatory factor in hTRX, the positive charge and lack of dimer formation of hTRXL-N suggest that it could interact with the acidic amino-acid rich C-terminal region, thereby suggesting a novel regulation mechanism. [ABSTRACT FROM AUTHOR]

The rheological properties of shear granular system under inertial flow regimes are investigated by fully considering both strong/weak and sliding/non-sliding contact features of four dual-partitioned subnetworks. Discrete element simulation results reveal that strong non-sliding subnetwork plays a dominant role in bearing external load. For strong sliding and weak non-sliding subnetworks, their anisotropy principal directions of normal contact forces undergo dynamic deflections during evolution, resulting in the lateral support of microstructures being primarily borne by unstable sliding contacts. Although the subnetworks display substantial variations in stability, their strong spatial correlation makes these variations complement each other, forming an intrinsic coupling relationship. [Display omitted] • The whole contact network is divided into four dual-partitioned subnetworks. • Flow evolution alters both the anisotropy and geometric relationships of dual-partitioned subnetworks. • The subnetworks complement each other in stability to achieve dynamic balance within microstructures. • Sliding subnetworks provide lateral support for granular system and contribute to flow evolution. [ABSTRACT FROM AUTHOR]

In this paper, we develop a new time-space fractional constitution relation to study the unsteady boundary layer flow over a stretching sheet. For the convenience of calculation, the boundary layer flow is simulated as a symmetrical rectangular area. The implicit difference method combined with an L1-algorithm and shift Grünwald scheme is used to obtain the numerical solutions of the fractional governing equation. The validity and solvability of the present numerical method are analyzed systematically. The numerical results show that the thickness of the velocity boundary layer increases with an increase in the space fractional parameter γ. For a different stress fractional parameter α , the viscoelastic fluid will exhibit viscous or elastic behavior, respectively. Furthermore, the numerical method in this study is validated and can be extended to other time-space fractional boundary layer models. [ABSTRACT FROM AUTHOR]

The 4-diphosphocytidyl-2- C-methyl- d-erythritol kinase (IspE) from Mycobacterium tuberculosis, an enzyme from the 2- C-methyl- d-erythritol 4-phosphate (MEP) pathway, is crucial and essential for the survival of this pathogenic bacterium. IspE catalyzes the conversion of 4-diphosphocytidyl-2- C-methyl- d-erythritol (CDP-ME) to 4-diphosphocytidyl-2- C-methyl- d-erythritol 2-phosphate (CDP-ME2P) in an ATP-dependent manner. Solving the crystal structure of M. tuberculosis IspE will shed light on its structural details and mechanism of action and may provide the basis for the future design of drugs for the treatment of multidrug-resistant and extremely drug-resistant M. tuberculosis strains. Recombinant M. tuberculosis IspE was crystallized at 291 K using NaCl or Li2SO4 as a precipitant. A 2.1 Å resolution native data set was collected from a single flash-cooled crystal (100 K) belonging to space group P212121, with unit-cell parameters a = 52.5, b = 72.3, c = 107.3 Å. One molecule was assumed per asymmetric unit, which gives a Matthews coefficient of 3.4 Å3 Da−1 with 63% solvent content. [ABSTRACT FROM AUTHOR]

This paper studies the compound effect of liquid medium and laser on the workpiece and analyses the law of material surface temperature change during the processing. Taking 7075-T6 aluminum alloy as the research object, the surface temperature field of aluminum alloy processed using water-jet-assisted laser machining under different process parameters was simulated using finite element software. In addition, the temperature field of the material surface was detected in real-time using the self-built water-jet-assisted laser machining temperature field detection system, and the processing results were observed and verified using an optical microscope, scanning electron microscope, and energy spectrum analyzer. The results show that when the water jet inflow angle is 45°, the heat-affected area of the material surface is the smallest, and the cooling effect of the temperature field of the material surface is better. Considering the liquidus melting point of 7075 aluminum alloys, it is concluded that the processing effect is better when the water jet velocity is 14 m·s−1, the laser power is 100 W, and the laser scanning speed is 1.2 mm·s−1. At this time, the quality of the tank is relatively good, there are no cracks in the bottom of the tank, and there is less slag accumulation. Compared with anhydrous laser etching, water-jet-assisted laser etching can reduce the problems of micro-cracks, molten slag, and the formation of a recast layer in laser etching and improve the quality of the workpiece, and the composition of the bottom slag does not change. This study provides theoretical guidance and application support for the selection and optimization of process parameters for water-jet-assisted laser etching of aluminum alloy and further enriches the heat transfer mechanism of multi-field coupling in the process of water-jet-assisted laser machining. [ABSTRACT FROM AUTHOR]

Laser micromachining has proven to be a useful tool for the precision processing of semiconductors. In the hybrid laser-water jet micromachining process investigated in this research, a laser is used for heating and softening the work material (polycrystalline silicon, in this case), while a water jet is employed for shearing the softened material and subsequently removing it due to the high-velocity of the liquid jet impingement, as well as for cooling the material. Specifically, the use of a low-pressure water jet to assist with the laser etching of polycrystalline silicon was investigated in this study. The energy efficiency of the processing as well as the width, depth, and surface microstructure of the groove etched in the polycrystalline silicon using the composite process were considered. With increasing jet velocity, the integrated energy initially decreased before increasing and the overall groove depth decreased, then increased, and finally decreased again. When the incidence angle was 30°, the groove width in the polypolycrystalline silicon increased as the jet velocity increased from 8 and 28 m s−1, and the use of a low-pressure jet to assist with the laser etching resulted in etched surfaces smoother than those obtained in air and hydrostatic conditions. The experimental results prove that the low-pressure water-jet-assisted laser etching technique can overcome the problems of micro-crack, slag, and recast layer formation that affect traditional laser etching and consequently improve the quality of machined parts. [ABSTRACT FROM AUTHOR]

In this article, we explore the heat transfer of non-Newtonian liquid food in the heating process in a channel connecting a tank. To achieve a rapid heat diffusion, several cylindrical agitators are inserted into the tank. We pay special attention to a Chinese traditional food, i.e. the black sesame paste, which is predicted by the power-law model. The fluid flow and heat transfer are investigated numerically, under the impacts of the angular velocity of cylinder, the stirrer size and the rotational direction. Three different settings are investigated: the two-stirrer, the three-stirrer, and the 2 × 2 stirrer settings. Several applicable strategies could be applied to improve the heat transfer in food engineering practices, including changing the size, the rotational velocity, the direction, and the number of stirrers in the heat exchanger. [ABSTRACT FROM AUTHOR]

The microstructure, surface quality, and thermal shielding properties of the coatings prepared by the methods of magnetron sputtering and electroplating are studied. The results show that the Cr–Ag coating prepared by means of magnetron sputtering is smoother, its porosity and emissivity are lower, and the hardness is higher than that of the coating prepared by means of electroplating. [ABSTRACT FROM AUTHOR]

The prevalence of type 2 diabetes mellitus has been increasing worldwide and more than two thirds of the patients may develop diabetic nephropathy (DN). However, the efficiency of existing approaches on DN progression is limited. 6-Shogaol (6-SG), a major dehydrated derivative of gingerols, possesses various biological properties. The present study was designed to evaluate the possible effects of 6-SG on DN in db/db mice and to investigate the mechanisms. We revealed that 6-SG reduced the levels of fasting blood glucose, serum insulin, C-peptide, glycosylated hemoglobin A1c, and systolic blood pressure. 6-SG decreased the levels of blood urea nitrogen (BUN), serum creatinine, urinary albumin content and albumin/creatinine ratio (ACR), ameliorated the pathological injuries of kidneys, reduced the surface area of Bowman’s capsule, Bowman’s space, glomerular tuft, and decreased the expression of collagen IV and fibronectin in kidneys of db/db mice. The high levels of systemic and renal triglyceride and cholesterol were decreased by 6-SG. Moreover, 6-SG exhibited anti-inflammatory effects, as reflected by reduction of tumor necrosis factor ɑ (TNFɑ), monocyte chemotactic protein-1 (MCP-1), and IL-6 levels in circulation and kidneys, and decrease of NF-κB expression. Furthermore, 6-SG also inhibited oxidative stress and restored the expression of NF-E2-related factor 2 (Nrf2) in kidneys of db/db mice. In conclusion, we have demonstrated that 6-SG exhibits anti-diabetic and renal protective effects against DN, in which effect the anti-inflammatory, hyperlipidemic, anti-oxidative activities may be involved. Overall, 6-SG could be a promising therapeutic treatment to ameliorate diabetes and the development of DN. [ABSTRACT FROM AUTHOR]

Fractional shear stress and Cattaneo heat flux models are introduced in characterizing unsteady Marangoni convection heat transfer of viscoelastic Maxwell fluid over a flat surface. Governing equations and boundary condition are formulated firstly via the balance between the surface tension and shear stress. Numerical solutions are obtained by new developed numerical technique and some novel phenomena are found. Results shown that the fractional derivative parameters, Marangoni number and power law exponent have significant influence on characteristics velocity and temperature fields. As fractional derivative parameters increase, the temperature profiles rise remarkably and the viscoelastic effects of the fluid enhance with delayed response to surface tension, however the temperature profiles decline significantly with a thinner thickness of thermal boundary layer with the increase of Marangoni number. The average skin friction coefficient increases with the augment of Marangoni number, while the average Nusselt number decreases for larger values of power law exponent. [ABSTRACT FROM AUTHOR]

In this paper, the mixed convective heat transfer mechanism of nanofluids is investigated. Based on the Buongiorno model, we develop a novel Cattaneo–Buongiorno model that reflects the non-local properties as well as Brownian motion and thermophoresis diffusion. Due to the highly non-linear character of the equations, the finite difference method is employed to numerically solve the governing equations. The effectiveness of the numerical method and the convergence order are presented. The results show that the rise in the fractional parameter δ enhances the energy transfer process of nanofluids, while the fractional parameter γ has the opposite effect. In addition, the effects of Brownian motion and thermophoresis diffusion parameters are also discussed. We infer that the flow and heat transfer mechanism of the viscoelastic nanofluids can be more clearly revealed by controlling the parameters in the Cattaneo–Buongiorno model. [ABSTRACT FROM AUTHOR]

The number of cars on roadways around the world continues to increase year over year. However, the imbalance between traffic supply and demand has not only brought traffic congestion but also caused serious safety problems. To reduce travel risk, this study proposes a driver route planning method based on accident risk cost prediction for connected and automated vehicles. According to the entropy weight method and an improved algorithm of K shortest paths, a route planning model with accident risk as the main optimization objective was established. Firstly, an accident risk evaluation system was built based on traffic accident data, and a quantitative prediction model of accident risk cost based on driver-, vehicle-, road-, and environment-related factors was constructed. Secondly, the entropy weight method was used to calculate the weights of each indicator to determine accident risk considering the aforementioned factors. Then, the route planning model was established, and the solution algorithm based on K shortest paths was designed to solve the optimal route by comprehensively considering accident risk cost and travel time. The accident risk index of each road section in the example road network was assigned, and the risk of the road section was quantified according to the accident risk cost model. Three candidate paths were calculated by using the path planning algorithm proposed in this study; the total risk cost is 6.19, 6.26, and 6.39, respectively; and the total travel time is 29, 29, and 31, respectively. After comparison, the optimal path and two alternative paths are obtained. The results show that the accident risk cost prediction model based on historical accident data can be used to quantify driving risk. The proposed method can help drivers in the connected and automated environment choose the optimal travel route with the lowest risk and shortest travel time and improve overall traffic safety and efficiency. [ABSTRACT FROM AUTHOR]

• Ozone microbubble treatment is a gentle and effective washing technology. • The hydroxyl radicals in water maintained about 9.3 μmol·L-1 by ozone microbubbles. • The hydrophobicity of apricot skin affects the pesticide residues removal adversely. • Ozone microbubble treatment does not significantly affect vitamin C in fruits. Developing a straightforward method to remove pesticide residues from fruits is essential for food safety. In this study, ozone microbubble treatment was performed on three fruits (strawberry, cherry, and apricot) to remove four pesticide residues (emamectin benzoate, azoxystrobin, boscalid, and difenoconazole) while comparing removal efficiency. The concentration of hydroxyl radicals in different washing orientations was homogeneous at a concentration ranging between 8.9 and 10.2 μmol·L-1. Under long washing time (18 min), strawberry, cherry, and apricot obtained higher removal rates of 51 %∼65 %, 51 %∼59 % and 24 %∼70 %, respectively. Moreover, scanning electron microscopy (SEM) and contact angle (CA) revealed that apricot has better hydrophobicity, leading to a higher pesticide removal of 45 ∼ 84 % with less water and more vigorous washing. Notably, vitamin C content in fruits remain largely unchanged following ozone microbubble treatment. This study demonstrated the effectiveness of ozone microbubble treatment as pollution-free method for enhancing food safety by removing pesticide residues on fruits. [ABSTRACT FROM AUTHOR]

The mechanism of obesity‐related metabolic dysfunction involves the development of systemic inflammation, largely mediated by macrophages. Switching of M1‐like adipose tissue macrophages (ATMs) to M2‐like ATMs, a population of macrophages associated with weight loss and insulin sensitivity, is considered a viable therapeutic strategy for obesity‐related metabolic syndrome. However, mechanisms for reestablishing the polarization of ATMs remain elusive. This study demonstrates that CD146+ ATMs accumulate in adipose tissue during diet‐induced obesity and are associated with increased body weight, systemic inflammation, and obesity‐induced insulin resistance. Inactivating the macrophage CD146 gene or antibody targeting of CD146 alleviates obesity‐related chronic inflammation and metabolic dysfunction. Macrophage CD146 interacts with Glycoprotein 130 (Gp130), the common subunit of the receptor signaling complex for the interleukin‐6 family of cytokines. CD146/Gp130 interaction promotes pro‐inflammatory polarization of ATMs by activating JNK signaling and inhibiting the activation of STAT3, a transcription factor for M2‐like polarization. Disruption of their interaction by anti‐CD146 antibody or interleukin‐6 steers ATMs toward anti‐inflammatory polarization, thus attenuating obesity‐induced chronic inflammation and metabolic dysfunction in mice. The results suggest that macrophage CD146 is an important determinant of pro‐inflammatory polarization and plays a pivotal role in obesity‐induced metabolic dysfunction. CD146 could constitute a novel therapeutic target for obesity complications. [ABSTRACT FROM AUTHOR]

Background: African swine fever virus (ASFV) is a highly lethal virus that can infect porcine alveolar macrophages (PAMs). Since ASFV, China has dealt with a heavy blow to the pig industry. However, the effect of infection of ASFV strains isolated from China on PAM transcription level is not yet clarified. Methods: In this study, RNA sequencing (RNA-seq) was used to detect the differential expression of genes in PAMs at different time points after ASFV-CN/GS/2018 infection. The fluorescent quantitative polymerase chain reaction (qPCR) method was used to confirm the altered expression of related genes in PAMs infected with ASFV. Results: A total of 1154 differentially expressed genes were identified after ASFV-CN/GS/2018 infection, of which 816 were upregulated, and 338 were downregulated. GO and KEGG analysis showed that these genes were dynamically enriched in various biological processes, including innate immune response, inflammatory response, chemokines, and apoptosis. Furthermore, qPCR verified that the DEAD box polypeptide 58 (DDX58), Interferon-induced helicase C domain-containing protein 1 (IFIH1), Toll-like receptor 3 (TLR3), and TLR7 of PAMs were upregulated after ASFV infection, while TLR4 and TLR6 had a significant downward trend during ASFV infection. The expression of some factors related to antiviral and inflammation was altered significantly after ASFV infection, among which interferon-induced protein with tetratricopeptide repeats 1 (IFIT1), IFIT2, Interleukin-6 (IL-6) were upregulated, and Ewing's tumor-associated antigen 1 homolog (ETAA1) and Prosaposin receptor GPR37 (GPR37) were downregulated. In addition, we discovered that ASFV infection is involved in the regulation of chemokine expression in PAMs, and the chemokines, such as C-X-C motif chemokine 8 (CXCL8) and CXCL10, were upregulated after infection. However, the expression of chemokine receptor C-X-C chemokine receptor type 2 (CXCR2) is downregulated. Also, that the transcriptional levels of pro-apoptotic and anti-apoptotic factors changed after infection. Conclusions: After ASFV-CN/GS/2018 infection, the expression of some antiviral and inflammatory factors in PAMs changed significantly. The ASFV infection may activates the RLR and TLR signaling pathways. In addition, ASFV infection is involved in regulating of chemokine expression in PAMs and host cell apoptosis. [ABSTRACT FROM AUTHOR]

Background: African swine fever virus (ASFV) is a highly lethal virus that can infect porcine alveolar macrophages (PAMs). Since ASFV, China has dealt with a heavy blow to the pig industry. However, the effect of infection of ASFV strains isolated from China on PAM transcription level is not yet clarified. Methods: In this study, RNA sequencing (RNA-seq) was used to detect the differential expression of genes in PAMs at different time points after ASFV-CN/GS/2018 infection. The fluorescent quantitative polymerase chain reaction (qPCR) method was used to confirm the altered expression of related genes in PAMs infected with ASFV. Results: A total of 1154 differentially expressed genes were identified after ASFV-CN/GS/2018 infection, of which 816 were upregulated, and 338 were downregulated. GO and KEGG analysis showed that these genes were dynamically enriched in various biological processes, including innate immune response, inflammatory response, chemokines, and apoptosis. Furthermore, qPCR verified that the DEAD box polypeptide 58 (DDX58), Interferon-induced helicase C domain-containing protein 1 (IFIH1), Toll-like receptor 3 (TLR3), and TLR7 of PAMs were upregulated after ASFV infection, while TLR4 and TLR6 had a significant downward trend during ASFV infection. The expression of some factors related to antiviral and inflammation was altered significantly after ASFV infection, among which interferon-induced protein with tetratricopeptide repeats 1 (IFIT1), IFIT2, Interleukin-6 (IL-6) were upregulated, and Ewing's tumor-associated antigen 1 homolog (ETAA1) and Prosaposin receptor GPR37 (GPR37) were downregulated. In addition, we discovered that ASFV infection is involved in the regulation of chemokine expression in PAMs, and the chemokines, such as C-X-C motif chemokine 8 (CXCL8) and CXCL10, were upregulated after infection. However, the expression of chemokine receptor C-X-C chemokine receptor type 2 (CXCR2) is downregulated. Also, that the transcriptional levels of pro-apoptotic and anti-apoptotic factors changed after infection. Conclusions: After ASFV-CN/GS/2018 infection, the expression of some antiviral and inflammatory factors in PAMs changed significantly. The ASFV infection may activates the RLR and TLR signaling pathways. In addition, ASFV infection is involved in regulating of chemokine expression in PAMs and host cell apoptosis. [ABSTRACT FROM AUTHOR]

A biocompatible and modifiable protein nanocarrier is a promising candidate for tumor targeted drug delivery. However, it is challenging to effectively load hydrophobic drugs, not to mention to upload both hydrophilic and hydrophobic drugs on one protein nanocarrier. Here, an amphiphilic multi‐drug loading protein nanocage (Am‐PNCage) is presented which is generated by replacing the fifth helix of human H‐ferritin (HFn) subunit with a functional motif composed of hydrophobic–hydrophilic‐RGD peptides. The Am‐PNCage possesses a dual targeting property resulting from the intrinsic CD71 targeting ability of HFn and the integrin α vβ3 targeting ability of displayed RGD peptides. Through the hydrophilic drug entry channel in the protein nanocage and hydrophobic peptides displayed on the outer surface, amphiphilic epirubicin (132)/camptothecin (50) are stereoscopically loaded into the inner cavity/outer protein shell, respectively, for one Am‐PNCage, exhibiting cascade drug release pattern. The dual‐targeted Am‐PNCage promotes the loaded drugs penetrating various 3D tumor models in vitro, as well as traversing the brain blood barrier and accumulating in brain tumors in vivo. Moreover, the drug loaded Am‐PNCage shows reduced side effects and significantly enhances synergistic efficacy against brain tumor, metastatic liver cancers, and drug resistant breast tumor. Thus, the Am‐PNCage represents a novel promising protein nanocarrier for targeted combination chemotherapy. [ABSTRACT FROM AUTHOR]

Obesity and its related complications pose an increasing threat to human health; however, targetable obesity‐related membrane receptors are not yet elucidated. Here, the membrane receptor CD146 is demonstrated to play an essential role in obesity. In particular, CD146 acts as a new adipose receptor for angiopoietin‐like protein 2 (ANGPTL2), which is thought to act on endothelial cells to activate adipose inflammation. ANGPTL2 binds to CD146 to activate cAMP response element‐binding protein (CREB), which then upregulates CD146 during adipogenesis and adipose inflammation. CD146 is present in preadipocytes and mature adipocytes, where it is mediated by its ligands ANGPTL2 and galectin‐1. In preadipocytes, CD146 ablation suppresses adipogenesis, whereas the loss of CD146 in mature adipocytes suppresses lipid accumulation and enhances energy expenditure. Moreover, anti‐CD146 antibodies inhibit obesity by disrupting the interactions between CD146 and its ligands. Together, these findings demonstrate that ANGPTL2 directly affects adipocytes via CD146 to promote obesity, suggesting that CD146 can be a potential target for treating obesity. [ABSTRACT FROM AUTHOR]

Obesity and its related complications pose an increasing threat to human health; however, targetable obesity‐related membrane receptors are not yet elucidated. Here, the membrane receptor CD146 is demonstrated to play an essential role in obesity. In particular, CD146 acts as a new adipose receptor for angiopoietin‐like protein 2 (ANGPTL2), which is thought to act on endothelial cells to activate adipose inflammation. ANGPTL2 binds to CD146 to activate cAMP response element‐binding protein (CREB), which then upregulates CD146 during adipogenesis and adipose inflammation. CD146 is present in preadipocytes and mature adipocytes, where it is mediated by its ligands ANGPTL2 and galectin‐1. In preadipocytes, CD146 ablation suppresses adipogenesis, whereas the loss of CD146 in mature adipocytes suppresses lipid accumulation and enhances energy expenditure. Moreover, anti‐CD146 antibodies inhibit obesity by disrupting the interactions between CD146 and its ligands. Together, these findings demonstrate that ANGPTL2 directly affects adipocytes via CD146 to promote obesity, suggesting that CD146 can be a potential target for treating obesity. [ABSTRACT FROM AUTHOR]

• Microalgae adhesion at the pH of 5.5, 6.8 and 8.1 was investigated. • Effect of pH on adhesion can be elucidated by identifying the dominant interaction. • Adhesion would be dominated by Acid-base (AB) or electrostatic (EL) interaction. • When EL interaction dominated, adhesion decreased with increasing pH. • When AB interaction dominated, adhesion increased with increasing pH. Microalgae adhesion plays a critical role in developing effective photobioreactors for large-scale production of microalgae biofuel. This study focused on elucidating the influencing mechanism of liquid medium pH on microalgae adhesion by identifying the dominant interactions between cell and substratum using a criterion. Herein, the adhesion of three microalgae onto two substrata at a series of pH was observed using a flow chamber. The results indicated that the adhesion of freshwater Chlorella sp. onto PVC and glass and marine Chlorella sp. and N. oculata onto glass decreased with increasing pH, because these adhesions were dominated by the EL interaction, and the pH would influence the adhesion primarily by affecting the ζ potential of the cell and substratum. Whereas, the adhesion of marine Chlorella sp. and N. oculata onto PVC increased with increasing pH, because these adhesions were dominated by Lewis acid-base (AB) interaction, and the pH would influence the adhesion primarily by affecting the components of surface free energy of cell. The study demonstrated that the influencing mechanism of pH on adhesion can be conclusively elucidated by identifying the dominant interaction between the cell and the surface, and may have significant implications for predicting cell adhesion in various applications. [ABSTRACT FROM AUTHOR]

• Temporal and spatial correlations, based on road attribute factors, are considered on tensor inputs to improve the imputation of missing speed data. • Robust speed data imputation based on BGCP for different missing modes. • Combining multi-source feature variables to develop accident detection models based on XGBoost. • The effectiveness of data attribution with different missing patterns in accident detection is explored. Facing the currently large quantity of intelligent transportation data, missing ones is often inevitable. Some previous works have shown the advantages of tensor decomposition-based approaches in solving multi-dimensional data imputation problems. However, a research gap still exists in examining the effect of applying these methods on imputation performance and their application to accident detection. Thus, referring to a two-month spatiotemporal traffic speed dataset, collected on the national trunk highway in Shandong, China, this paper employs the Bayesian Gaussian CANDECOMP/PARAFAC (BGCP) to impute missing speed data in different missing rates and missing scenarios. Moreover, the dataset is built while considering both the temporal and the road functions. Applying the generated results of data imputation in accident detection is also of the main targets of this work. Thus, while combining multiple sources of data, such as traffic operation status and weather, eXtreme Gradient Boosting (XGBoost) is deployed to build accident detection models. The generated results show that the BGCP model can produce accurate imputations even under temporally correlated data corruption. Added to that, it is also suggested that, when there are continuous periods of missing speed data (missing rate greater than 10%), pre-processing of data imputation is imperative to maintain the accuracy of accident detection. Thus, the objective of this work is to provide insights into traffic management and academics when performing spatiotemporal data imputation tasks. [ABSTRACT FROM AUTHOR]

In this paper, a spatial fractional-order thermal transport equation with the Caputo derivative is proposed to describe convective heat transfer of nanofluids within disordered porous media in boundary layer flow. This equation arises naturally when the effect of anomalous migration of nanoparticles on heat transfer is considered. The numerical results show that local Nusselt numbers of four different kinds of nanofluids are all inversely proportional to the fractional derivative exponent β . Based on this finding, it is concluded that the anomalous diffusion of nanoparticles improves the convective heat transfer of nanofluids and the space fractional thermal transport equation may serve as a candidate model for studying nanofluids. Additionally, the effects of other involved physical parameters on temperature distribution and Nusselt number are presented and analyzed. [ABSTRACT FROM AUTHOR]

The North Fuling area is located in the Eastern Sichuan Basin, China. Natural gas and condensates are commonly found in the Jurassic shales (including Lianggaoshan, Da'anzhai, and Dongyuemiao shales) in this area. Multiple geochemical approaches and tests including methane concentration, C 2+ concentration, and stable isotopes were employed to determine the geochemical characteristics and the origin of the gas samples from the Jurassic shales. The analyses reveal that: (1) natural gas in the Jurassic shales is predominantly wet gas with the methane concentration of 36.89% ∼ 94.27%; (2) δ 13 C values range between −49.4 ∼ −44.2‰/VPDB in methane, −33.0 ∼ −30.0‰/VPDB in ethane, and −28.7 ∼ −26.5‰/VPDB in propane; the crossplot of isotope data indicates the gas samples are oil-associated gas which probably originated from the cracking of crude oil; (3) thermal maturity in terms of vitrinite reflectance equivalence of the gas samples ranges from 0.8% to 1.2%; and (4) gas-source correlation suggests the gas in Jurassic shales is generated from Da'anzhai shale, of which organic matter is primarily Type II and R o ranges from 1.06% to 1.28%. [ABSTRACT FROM AUTHOR]

[Display omitted] • Amino acid ionic liquids with affinity to benzimidazoles were screened by COSMO-RS. • Amino acid ionic liquid-based magnetic nanoparticles with specific task were prepared. • Magnetic dispersive solid-phase extraction for benzimidazoles was optimized. • The adsorption mechanism was verified experimentally and theoretically. • The method was applied to the detection of benzimidazoles in juice and human serum. The theoretical screening and design of green solvents to reduce organic solvents and to develop green and efficient sample pretreatment methods have attracted extensive attention. Here, benzimidazoles (BZDs) with potential reproductive toxicity were used as target compounds, and amino acid ionic liquids (AAILs) were designed and selected via a theoretical calculation. With the functionalized AAIL as monomers, and POSS as the crosslinking agent, novel specific magnetic nanoparticles (Fe 3 O 4 @SiO 2 @MAPs@AAIL-POSS) were prepared and used to develop the magnetic dispersive solid-phase extraction (MDSPE) of trace BZDs from fruit juice and human serum. In the evaluation of the method, Fe 3 O 4 @SiO 2 @MAPs@AAIL-POSS showed specific adsorption, recyclable ability, high adsorption efficiency, a good recovery rate, and a low coefficient of variation. In addition, the adsorption behavior of Fe 3 O 4 @SiO 2 @MAPs@AAIL-POSS on BZDs was verified by investigating the kinetic and thermodynamic of the adsorption process. The study design provides ideas for green rapid detection methods of other food pollutants. [ABSTRACT FROM AUTHOR]

African swine fever (ASF) is an infectious disease caused by the African swine fever virus (ASFV), and has a high mortality rate. It has caused serious socioeconomic consequences worldwide. Currently, there are no available commercial vaccines or antiviral drug interventions. D1133L is one of the key genes for ASFV replication and antiviral drug screening. In this study, a virtual screening software program, PyRx, was used to screen libraries of compounds against the potential drug target D1133L. Twelve compounds with a high affinity for ASFV D1133L were screened, and cyproheptadine hydrochloride (periactin) was identified as a candidate drug. The periactin has little cytotoxicity, and which dose-dependently inhibited ASFV replication in vitro. Further research indicated that periactin could significantly down-regulate D1133L at the transcriptional and protein levels with RT-qPCR and western blot methods. This study has provided important candidate drugs for the prevention and treatment of ASF, as well as biological materials and new fields of view for the research and development of vaccines and drugs for ASFV. • This study predicted the tertiary structure of ASFV D1133L, docked with 3206 FDA approved small molecule drugs in ZINC database, counted the binding energy of them, and screened 12 small molecules with binding energy ≥11.0 kcal/mol for antiviral activity verification based on cell level. • It is proved that small molecule compound Periactin significantly inhibited the replication of ASFV in BMDMs. • It is proved that small molecule compound Periactin could significantly inhibit the transcription and expression of D1133L which are important for ASFV replication. • It is proved that the small molecule compound periactin has less cytotoxicity. [ABSTRACT FROM AUTHOR]

This paper investigates the flow and heat transfer of Ostwald-de Waele fluid over a variable thickness rotating disk with style of z = a ( r / R 0 + 1) − m . Boundary layer governing partial equations are reduced to a set of semi-similarity ordinary differential equations by modified local von Kármán’s transformation and then solved by Runge–Kutta method coupled with multi-shooting technique. The effects of involved parameters (Ostwald-de Waele fluid physical power law exponent, disk thickness index, Prandtl number) on velocity and temperature fields, local skin friction coefficient and Nusselt number are presented graphically. Some new phenomena are found. Results indicate that, unlike the flat rotating disk, the local radial skin friction coefficients and tangential decrease with the fluid physical power law exponent increases, the peak in the radial velocity rises which is significantly distinct from the results of a power-law fluid over a flat rotating disk. As disk thickness index m increases, the local radial skin friction coefficient increases while local tangential skin friction coefficient decreases, the local Nusselt number decrease, both the thickness of velocity and temperature boundary layer increase. [ABSTRACT FROM AUTHOR]

The aim of this work was to study the light/dark (L/D) cycle in raceway ponds (RWPs) by the computational fluid dynamics (CFD) method via determining the hydrodynamics of culture media and cell trajectories. The effects of paddlewheel rotational speed and flow-deflector baffles installation on the L/D cycle were analyzed. The results indicated that, the L/D cycles of microalgae cells decreased with the increase of the paddlewheel rotational speeds, when the paddlewheel rotational speeds ranged from 5 to 12 rpm. In addition, the installation of the flow-deflector baffles in RWPs can greatly increase the light time and the ratio of light time to L/D cycle for microalgae cells. The study provided an effective method to characterize the L/D cycles in RWPs, and may have important implications for designing the effective large-scale microalgae culture system. [ABSTRACT FROM AUTHOR]

In this study, the generalised velocity slip and the generalised temperature jump of nanofluid in the flow over a stretching sheet with variable thickness are investigated. Because of the non-adherence of the fluid to a solid boundary, the velocity slip and the temperature jump between fluid and moving sheet may happen in industrial process, so taking velocity slip and temperature jump into account is indispensable. It is worth mentioning that the analysis of the velocity v, which has not been seen in the previous references related to the variable thickness sheet, is presented. The thermophoresis and the Brownian motion, which are the two very important physical parameters, are fully studied. The governing equations are simplified into ordinary differential equations by the proper transformations. The homotopy analysis method (HAM) is applied to solve the reduced equations for general conditions. In addition, the effects of involved parameters such as velocity slip parameter, temperature jump parameter, Prandtl number, magnetic field parameter, permeable parameter, Lewis number, thermophoresis parameter, and Brownian motion parameter are investigated and analysed graphically. [ABSTRACT FROM AUTHOR]

Mechanism of interaction between virus and host is inferred from the changes of gene expression in macrophages infected with African swine fever virus CN/GS/2018 strain. Correction to: Virol J (2021) 18:170 https://doi.org/10.1186/s12985-021-01637-6 Following publication of the original article [[1]], the authors informed us that there is an inconsistency in Figure 1C, between the online version and the PDF version. [Extracted from the article]

African swine fever virus (ASFV) is prevalent in many countries and is a contagious and lethal virus that infects pigs, posing a threat to the global pig industry and public health. The interaction between the virus and the host is key to unlocking the mystery behind viral pathogenesis. A comprehensive understanding of the viral and host protein interaction may provide clues for developing new antiviral strategies. Here, we show a network of ASFV MGF360-9L protein interactions in porcine kidney (PK-15) cells. Overall, 268 proteins that interact with MGF360-9L are identified using immunoprecipitation and liquid chromatography–mass spectrometry (LC-MS). Accordingly, gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were conducted, and the protein–protein interaction (PPI) network was created. It was speculated that the cellular proteins interacting with MGF360-9L are involved in protein binding, metabolism, and the innate immune response. Proteasome subunit alpha type (PSMA3), 26S protease regulatory subunit 4 (PSMC1), autophagy and beclin 1 regulator 1 (AMBRA1), and DEAD-box helicase 20 (DDX20) could interact with MGF360-9L in vitro. PSMA3 and PSMC1 overexpression significantly promoted ASFV replication, and MGF360-9L maintained the transcriptional level of PSMA3 and PSMC1. Here, we show the interaction between ASFV MGF360-9L and cellular proteins and elucidate the virus–host interaction network, which effectively provides useful protein-related information that can enable further study of the potential mechanism and pathogenesis of ASFV infection. [ABSTRACT FROM AUTHOR]

Factor I (fI) is a major regulator of complement. As a protease it has very restricted specificity, cleaving only C3b or C4b in the presence of a cofactor such as factor H (fH). Cleavage of C3b by if yields iC3b, a major opsonin. The cleavage occurs through the formation of a ternary complex between the enzyme, the substrate, and the cofactor. The catalytic subunit of fi, the SP domain, accommodates substrate recognition and cleavage. The role of the if heavy chain within the catalysis complex is unknown. Using partial proteolysis and affinity chromatography an intact form of the SP domain was generated and isolated from fI in high yield. fI and the SP domain were found to have similar amidolytic activities but strikingly different proteolytic activities on C3(NH3). fI did not cleave C3(NH3) in the absence of fH, while in its presence it cleaved C3(NH3) rapidly at two sites. The SP domain, however, slowly cleaved C3(NH3) in the absence of fH, at more than two sites. Cleavage by the SP domain was inhibited, not stimulated, by fH. Pefabloc SC and antipain inhibited the proteolytic activity of both fI and the SP domain, but suramin inhibited only fI and not the SP domain. The contrast in the proteolytic activities suggests that the heavy chain domains and the cofactor must have roles in orienting the natural substrates and restricting cleavage to the two sites which yield iC3b through a highly specific catalysis. [ABSTRACT FROM AUTHOR]

We have determined the crystal structure of a 154residue intein derived from the dnaB gene of Synechocystis sp. strain PCC6803 and refined it to a 2.0-Å resolution. The x-ray structure suggests that this intein possesses two catalytic sites that appear to be separately responsible for splicing and cleavage of the Nand C-terminal scissile bonds. The conserved intein block F residues are the important components of a catalytic site for side chain cyclization of the last intein residue, Asn-154. The data suggest that the imidazole ring of His-143 is involved in the activation of the side chain Nδ atom of Asn-154, leading to a nucleophilic attack on the carbonyl carbon of Asn-154. Substitution of His-143 with Ala or Gin resulted in the inhibition of C-terminal cleavage. His-153, Asp-136, and a water molecule appear to constitute an oxyanion binding site by contacting the carbonyl oxygen of Asn-154 to stabilize the transition state. The structure and mutagenesis data also support that the close contact between the hydroxyl groups of Thr-138 and Ser-155, whose side chain participates in an S → O acyl shift, plays an important role in the nucleophile orientation. Our structural modeling suggests that this catalytic module is conserved in the C-terminal subdomains of inteins from diverse organisms. [ABSTRACT FROM AUTHOR]

Keywords: cascade drug release; dual-tumor targeting; hydrophilic/hydrophobic drugs; protein cage nanocarrier; synergistic chemotherapy EN cascade drug release dual-tumor targeting hydrophilic/hydrophobic drugs protein cage nanocarrier synergistic chemotherapy 1 1 1 07/19/21 20210701 NES 210701 In article number 2102004, Xiyun Yan, Kelong Fan, and co-workers present an amphiphilic multi-drug loading protein nanocage (Am-PNCage) with a dual-tumor targeting (CD71 and Integrin) property, which exhibits a spatiotemporally programmed cascade drug release pattern and kills drug-resistant tumor cells synergistically. Synergistic Chemotherapy: Bioengineered Dual-Targeting Protein Nanocage for Stereoscopical Loading of Synergistic Hydrophilic/Hydrophobic Drugs to Enhance Anticancer Efficacy (Adv. Funct. Cascade drug release, dual-tumor targeting, hydrophilic/hydrophobic drugs, protein cage nanocarrier, synergistic chemotherapy. [Extracted from the article]

COVID-19 has evolved into a global pandemic. Early and rapid detection is crucial to control of the SARS-CoV-2 transmission. While representing the gold standard for early diagnosis, nucleic acid tests for SARS-CoV-2 are often complicated and time-consuming. Serological rapid antibody tests are characterized by high rates of false-negative diagnoses, especially during early infection. Here, we developed a novel nanozyme-based chemiluminescence paper assay for rapid and sensitive detection of SARS-CoV-2 spike antigen, which integrates nanozyme and enzymatic chemiluminescence immunoassay with the lateral flow strip. The core of our paper test is a robust Co–Fe@hemin-peroxidase nanozyme that catalyzes chemiluminescence comparable with natural peroxidase HRP and thus amplifies immune reaction signal. The detection limit for recombinant spike antigen of SARS-CoV-2 was 0.1 ng/mL, with a linear range of 0.2-100 ng/mL. Moreover, the sensitivity of test for pseudovirus could reach 360 TCID 50 /mL, which was comparable with ELISA method. The strip recognized SARS-CoV-2 antigen specifically, and there was no cross reaction with other coronaviruses or influenza A subtypes. This testing can be completed within 16 min, much shorter compared to the usual 1-2 h required for currently used nucleic acid tests. Furthermore, signal detection is feasible using the camera of a standard smartphone. Ingredients for nanozyme synthesis are simple and readily available, considerably lowering the overall cost. In conclusion, our paper test provides a high-sensitive point-of-care testing (POCT) approach for SARS-CoV-2 antigen detection, which should greatly facilitate early screening of SARS-CoV-2 infections, and considerably lower the financial burden on national healthcare resources. • Point-of-care antigen tests for screening of SARS-CoV-2 infection were established. • Chemiluminescence improves sensitivity of paper test and benefits early screening. • Nanozyme with high peroxidase activity and stability catalyzes chemiluminescence. • Nanozyme chemiluminescence paper test brings high efficiency and low cost. [ABSTRACT FROM AUTHOR]