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•The dynamic constitutive model of shear thickening fluid (STF) was defined based on the rheological performance curve.•The fluid–structure interaction analysis was completed based on ...the Structure-Arbitrary Lagrange Euler algorithm in ANSYS/LS-DYNA.•The ballistic limits of STF-Kevlar in the experiment and simulation were 72.40 m/s and 70.40 m/s, with an error of −2.8%.•The prediction, design and optimization of the ballistic performance of STF-Kevlar can be achieved through this numerical simulation method.
Shear thickening fluids (STFs) can effectively enhance the ballistic performance of Kevlar. Considering that the unique shear thickening effect of STF is the key factor to enhance the impact resistance of fabrics, this study sought to reveal the impact resistance mechanism of STF-Kevlar and guide its further design by using a numerical simulation method of fluid–structure interaction. The ballistic limits of neat Kevlar and STF-Kevlar in the ballistic tests were 55.14 m/s and 72.40 m/s, respectively, and the simulation predictions were 55.58 m/s and 70.40 m/s, which indicated that the established finite element model has high accuracy for predicting the ballistic performance curve of the fabric. The results of numerical simulation showed that STF-Kevlar has smaller deformation during the impact process than neat Kevlar. Due to the strengthening effect of STF, the resistance of STF-Kevlar to the elastomer was greater than that of neat fabric. With the increase of the impact velocity, the STF-Kevlar increasingly relied on STF to absorb energy. In engineering practice, through the fluid–structure interaction numerical simulation method, the prediction of the ballistic performance of the composite fabric can be realized in the early stage of manufacture, and guide further design and optimization.
Pancreatic ductal adenocarcinoma (PDAC) is the most common type of pancreatic cancer featured with high intra-tumoral heterogeneity and poor prognosis. To comprehensively delineate the PDAC ...intra-tumoral heterogeneity and the underlying mechanism for PDAC progression, we employed single-cell RNA-seq (scRNA-seq) to acquire the transcriptomic atlas of 57,530 individual pancreatic cells from primary PDAC tumors and control pancreases, and identified diverse malignant and stromal cell types, including two ductal subtypes with abnormal and malignant gene expression profiles respectively, in PDAC. We found that the heterogenous malignant subtype was composed of several subpopulations with differential proliferative and migratory potentials. Cell trajectory analysis revealed that components of multiple tumor-related pathways and transcription factors (TFs) were differentially expressed along PDAC progression. Furthermore, we found a subset of ductal cells with unique proliferative features were associated with an inactivation state in tumor-infiltrating T cells, providing novel markers for the prediction of antitumor immune response. Together, our findings provide a valuable resource for deciphering the intra-tumoral heterogeneity in PDAC and uncover a connection between tumor intrinsic transcriptional state and T cell activation, suggesting potential biomarkers for anticancer treatment such as targeted therapy and immunotherapy.
Intracutaneous pyonex therapy (IPT), a novel acupuncture technique also known as intradermal thumbtack needle embedding therapy, has been reported to optimize postoperative pain management following ...perianal surgery. This meta-analysis aimed to analyze the efficacy of IPT for postoperative pain management following perianal surgery. The Cochrane Library, PubMed, EMBASE, Web of Science, CNKI, SinoMed, Wanfang, and VIP databases were systematically searched for randomized controlled trials (RCTs) on IPT as a treatment for postoperative pain management following perianal surgery from inception until June 15, 2022. The analyzed outcomes from the eleven RCTs included in this meta-analysis were as follows: postoperative visual analogue scale(VAS), analgesic duration, ineffective cases following treatment, and adverse events. Subgroup analyses were conducted according to different time points. Risk-of-bias assessment, publication bias analysis, sensitivity analysis, and trial sequential analysis were performed. Of the 895 patients, 450 and 445 were included in the IPT and control groups, respectively. The IPT group showed a better analgesic effectstandard mean difference (SMD) = -0.77, 95% CI: -1.00 to -0.53, P < 0.00001; P for heterogeneity = 0.009, I2 = 59% and longer analgesic duration SMD = 0.56, 95% CI: 0.31 to 0.82, P < 0.0001; P for heterogeneity = 0.6, I2 = 0%, fewer ineffective cases following treatment risk ratio(RR) = 0.23; 95% CI: 0.13 to 0.39, P < 0.00001; P for heterogeneity = 0.76, I2 = 0%, and lower overall occurrence of postoperative complications RR = 0.35; 95% CI: 0.17 to 0.70; P = 0.003; P for heterogeneity = 0.85, I2 = 0% than the control group. Thus, our findings indicated that IPT can provide better pain management following perianal surgery compared to controls. This novel approach complements a reasonable modality for postoperative multimodal analgesia and is worth promoting.
Frequent landslides have generated huge security threats and economic losses all over the world. As an important anti-slip retaining structure, anti-slide piles can maintain the slope stability. The ...distribution of soil resistance acting on piles is the critical factor influencing the design of anti-slide piles, and the method of calculating the internal force is directly related to the landslide treatment and construction cost. However, limitations in the method of calculating the internal force of anti-slide piles still exist. In this paper, the influence of the internal force of anti-slide piles both considering and ignoring the soil resistance acting on the piles was verified using ABAQUS software, revealing that the soil resistance indeed had a significant effect on the anti-slide piles, especially when the gradient of the soil before piles was less than 40°. Therefore, the formula for calculating the internal force of anti-slide piles was proposed considering the soil resistance. Based on this formula, the optimum quantity of steel reinforcement and the safety factor were compared in practical slope engineering. This proposed formula considering actual distribution of soil resistance can be used for approximate calculation for anti-slide piles, which can reduce the construction cost, especially in large and neutral landslide engineering.
With recent developments, the performance of automotive radar has improved significantly. The next generation of 4D radar can achieve imaging capability in the form of high-resolution point clouds. ...In this context, we believe that the era of deep learning for radar perception has arrived. However, studies on radar deep learning are spread across different tasks, and a holistic overview is lacking. This review paper attempts to provide a big picture of the deep radar perception stack, including signal processing, datasets, labelling, data augmentation, and downstream tasks such as depth and velocity estimation, object detection, and sensor fusion. For these tasks, we focus on explaining how the network structure is adapted to radar domain knowledge. In particular, we summarise three overlooked challenges in deep radar perception, including multi-path effects, uncertainty problems, and adverse weather effects, and present some attempts to solve them.
In order to obtain the effect of hygrothermal aging on the high speed impact resistance of carbon fiber reinforced composites (CFRP), ballistic impact tests using flat blades projectile were ...conducted on the T700/TDE-85 laminates subjected to artificial accelerated hygrothermal aging (70 °C, RH95%) for different durations. Short beam shear tests were conducted on the aged specimens to evaluate the interfacial properties degradation. The effect of hygrothermal aging on the energy absorption and ballistic limit of composites were discussed. It is shown that the moisture absorption rate of the composites is in agreement with Fick law, with an equilibrium moisture absorption rate of 0.74% at 1369 h. The interlaminar shear strength (ILSS) descends rapidly with aging time and the retention rate of interlaminar shear strength was 50.6% after 2000 h. The ballistic limit and the critical energy absorption of the composites declined notably with the increase of aging time. Due to the weakened fiber/matrix interface, the delamination failure area in rhombic shape is of increasing severity with aging time. The matrix cracking and fiber/matrix interface debond due to long-term exposure to hygrothermal environment reduce the high velocity impact resistance of the composites.
The development of economical and efficient roadbed silt reinforcement technology not only guides the proficient utilization of silt resources but also fosters the green development of geotechnical ...engineering construction. Ensuring the robust dynamic stability of the roadbed is pivotal for the safe operation of vehicular traffic. In this context, employing recycled polyester fibers and inorganic curing agents, this paper leverages dynamic triaxial testing and scanning electron microscopy (SEM) methods to scrutinize the dynamic characteristics and microscopic mechanisms of recycled fiber polymer modified roadbed silt. The findings indicate that: (1) with a fiber content of 0.2%, the fiber-modified soil sample exhibits minimal damage, maximal dynamic strength and dynamic elastic modulus, and optimum resilience to dynamic loads; (2) akin to fiber-reinforced sand, an elevation in confining pressure can induce the creation of a quasi-cohesive force in fiber-reinforced soil, equivalently enhancing the confining pressure and thereby amplifying its strength; and (3) the surfaces of microparticles in the enhanced soil structure are enveloped with cementitious substances, while smaller soil particles coalesce to form aggregates that fill inter-particle pores, cultivating a denser and more stable improved soil structure and augmenting the dynamic characteristics of the improvement investment.
Nitric oxide (NO) is an active and critical nitrogen oxide in the microbe-driven nitrogen biogeochemical cycle, and is of great interest to medicine and the biological sciences. As a gas molecule ...prior to oxygen, NO respiration represents an early form of energy generation via various reactions in prokaryotes. Major enzymes for endogenous NO formation known to date include two types of nitrite reductases in denitrification, hydroxylamine oxidoreductase in ammonia oxidation, and NO synthases (NOSs). While the former two play critical roles in shaping electron transport pathways in bacteria, NOSs are intracellular enzymes catalyzing metabolism of certain amino acids and have been extensively studied in mammals. NO interacts with numerous cellular targets, most of which are redox-active proteins. Doing so, NO plays harmful and beneficial roles by affecting diverse biological processes within bacterial physiology. Here, we discuss recent advances in the field, including NO-forming enzymes, the molecular mechanisms by which these enzymes function, physiological roles of bacterial NOSs, and regulation of NO homeostasis in bacteria.
The internally cured material known as superabsorbent polymer (SAP) is an important innovation in concrete engineering technology. This paper investigates the effect of adding a polymer with ...superabsorbent capabilities on the physical and mechanical performance of concrete. The microstructure of the new hybrid concrete was also studied, and the influence of the polymer particle size and volume on the mechanical durability was evaluated. The mechanical properties of the new hybrid concrete, such as compressive strength, flexural strength, elastic modulus, and splitting tensile strength, were measured through laboratory experiments. The microstructure characteristics of the concrete were also investigated by scanning electron microscopy (SEM). The results show that shrinkage was reduced, while the volume stability of the concrete improved. Moreover, we found that cracking was reduced, while issues such as chloride penetration and freeze-thaw resistance were also improved. In addition, the SAP could effectively improve the microstructure of the concrete and refine the pore structure, as seen in the microscopic test. This paper helps to promote the development of internally cured material and improve technology for the prevention of concrete construction cracks.
•The responses of the NDVI to climatic factors were spatiotemporal heterogeneous.•Karst NDVI in southwest China was predicted based on multiple factors.•The model performance regarding NDVI at the ...spatial scales was relatively good.•The 1 km resolution NDVI data were suitable for predicting karst vegetation.
Karst vegetation (KV) is one of the most important indicators for maintaining the surface energy balance in southwestern China. The spatial pattern of KV is mainly affected by climate, human activities, and environmental factors. The relationships between the KV and these factors are complex and nonlinear. Most previous studies on the nonlinear relationship characteristics and regional regularity were not comprehensive. In this study, the correlation and the time-lagged response of KV to climatic factors were investigated using Pearson correlation analysis, and a nonlinear model of the relationships between the karst normalized difference vegetation index (NDVI) and multiple factors was built based on a back propagation neural network optimized using the beetle antennae search algorithm (BAS-BP), and then, the karst NDVI was predicted. The results showed that (1) in most karst regions, the seasonal NDVI was mainly influenced by temperature, but the autumn NDVI was mainly affected by precipitation. The correlation between the interannual variation in the NDVI and the interannual variation in the precipitation was higher than the correlation between the interannual variation in the NDVI and the interannual variation in temperature. The NDVI and the other climatic factors were not strongly correlated. The NDVI responded to the climatic factors with different time-lagged intervals in different spatiotemporal scales. (2) At multiple spatial scales, the mean correlation coefficient (R) and means squared error (MSE) values of the vegetation prediction in the different geomorphic areas were 0.6565 and 0.0072, respectively. The maximum R was up to 0.9059. In different lithology areas, the mean values of R and MSE were 0.6898 and 0.0072, respectively. The maximum R value was 0.9142. (3) The prediction model of the interannual variation in the NDVI was trained, and it was then tested for the validation period. The R values ranged from 0.5299 to 0.7744, with an average of 0.6606. In contrast to the prediction results on different spatial scales, the model’s performance regarding the interannual variation in the NDVI was relatively poor. (4) The mean R values were 0.6708, 0.5575, and 0.5468 and the mean MSE values were 0.0067, 0.0084, and 0.0114 for the 1 km, 250 m, and 8 km NDVI resolution predictions, respectively. The obtained results showed that the model’s performance regarding the NDVI prediction was better at a spatial resolution of 1 km than at spatial resolutions of 250 m and 8 km.
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