Search Results (13,812)

As a form of urban experience tour, cultural visiting routes provide an innovative approach to addressing the fragmentation and isolation of cultural resources in historic districts. This method emphasizes the systematic continuity of cultural spatial patterns and is currently implemented at both regional and urban scales. However, methods for constructing cultural visiting routes at the block scale still require further investigation. And there is a notable lack of studies that consider the integration of multiple systems in cultural visiting routes. Consequently, this research proposes a novel approach for constructing cultural visiting routes based on the coupling and coordination of multiple systems. Using the Zhongshan Road Historical and Cultural Block in Xiamen, China, as a case study, this study develops cultural visiting routes by analyzing the degree of coupling coordination between cultural resource value and the street walking environment. The findings are as follows: (1) The cultural visiting routes within the Zhongshan Road Block can be categorized into three levels: the first-level routes, represented by Zhongshan Road; the second-level routes, represented by Datong Road; and the third-level routes, represented by Park South Road. (2) The first-level cultural visiting routes demonstrate a high degree of coupling coordination, with an optimization direction focused on refined updates. The second-level routes exhibit a medium degree of coupling coordination, indicating an urgent need to address issues across the entire road section. The third-level routes reveal a low degree of coupling coordination, necessitating attention to the enhancement of cultural visiting elements. This study emphasizes that the construction of block-scale cultural visiting routes must prioritize not only the extraction of value from cultural resources but also the influence of the street walking environment. Full article

The horizontal-transverse coherence of low-frequency (300 Hz) and long-range (10–40 km) acoustic fields near the bottom in deep water is investigated based on experimental data obtained from the South China Sea. The results indicate that the horizontal-transverse coherence length exhibits a strong dependence on the source-receiver distance, with fluctuations consistent with sound intensity trends. In high-intensity regions, the horizontal-transverse coherence is relatively high, with a coherence length exceeding 600 λ, where λ is the acoustic wavelength, whereas in low-intensity regions, the horizontal-transverse coherence decreases significantly, with the coherence length shortening to 10–30 λ. The physical mechanisms underlying the horizontal-transverse coherence are analyzed using the ray theory. In high-intensity regions, the energy of the dominant ray (the ray with the highest energy) accounts for over 70% of the total energy of the rays, exerting a decisive influence on the coherence coefficient and leading to stable horizontal-transverse coherence in the received acoustic field. In contrast, in low-intensity regions, the energy distribution is dispersed, and when amplitude and phase disturbances due to spatial inhomogeneity are introduced, the horizontal coherence deteriorates significantly. The numerical simulations are also performed, and the results are consistent with the experimental observations. Full article

Utilizing crushed spontaneous combustion coal gangue as a coarse aggregate in concrete preparation effectively reduces reliance on natural resources and mitigates environmental pollution; however, the suboptimal workability of spontaneous combustion coal gangue coarse aggregate concrete (SCG-CAC) limits its engineering applications. To address this issue, this study places SCGCAC at the center of a CFDST (Concrete-Filled Double-Skin Steel Tubular) stub column. Through finite element modeling validated for reliability, this study examines the structural mechanical response to axial loading, along with the effects of various parameters. The analysis encompasses parameters such as the strength of the core SCGCAC (f_c,i), the strength of the sandwiched concrete (f_c,o), the yield strength of the outer steel tube (f_y,o), the yield strength of the inner steel tube (f_y,i), the width-to-thickness ratio (B/t_o), the diameter-to-thickness ratio of the inner tube (D/t_i), and the diameter-to-width ratio of the outer tube (D/B). Results show that this structural configuration significantly enhances the core SCGCAC ultimate bearing capacity, and increases in D/t_i, f_c,i, f_c,o, f_y,i, and B/t_o all lead to an increase in the peak load. Particularly, when D/t_i increases from 28.57 to 80, the peak load increases by 42.72%. However, changes in f_y,o and D/B have no significant effect on the peak load. Full article

Fear overgeneralization is a prevalent clinical symptom of anxiety disorders. Various research studies have demonstrated that attention plays a crucial role in fear generalization. Moreover, fear is not only generalized to the stimulus, but individuals may also exhibit a certain degree of fear generalization to the context. This research investigates whether fear generalizes to stimuli and context simultaneously and the potential impact of attentional bias. The study involved two conditioned fear factors, a stimulus and context, with visual image materials combining both elements. Participants were instructed to focus on global attention in Study 1, while in Study 2, they were divided into groups based on their attention bias direction towards either stimuli or context during the fear acquisition phase. This study found that participants exhibited generalized conditioned fear to both stimuli and context, regardless of attentional bias. Additionally, participants showed a lower degree of generalization in the area to which they directed their attention during the acquisition phase. The results of this research reveal the differing expressions of fear generalization towards context and stimuli, highlighting the important role of attention in this process. Full article

The seismic safety evaluation of artificial reef islands is of great significance for ensuring their long-term stable operation and the safety of residents’ lives. However, due to an insufficient understanding of coral reefs’ basic characteristics, current research on coral reef seismic stability neglects the influence of pore water pressure and abnormal reef layers formed during geological evolution. To further study the impact of earthquakes on coral reefs in the South China Sea, this paper takes Meiji Reef as the research object, establishes a 3-D model containing a saturated coral reef–seawater–seabed coupling system, and considers the influence of abnormally high-porosity weathered layers to study the seismic response of the coupling system in the frequency domain. The results show that ignoring the influence of pore water pressure will underestimate the impact of earthquakes on coral reefs. The seismic waves with a frequency of 4.1 Hz in the horizontal direction have a significant impact on the reef, and the side parallel to the direction of wave propagation is more affected, while the side perpendicular to the direction of wave propagation is less affected. The reef flat near the seawater side is less affected by earthquakes, while that on the lagoon side is more affected. Highly porous, weathered layers increase the seismic impact on reef flats. Full article

Sexually propagated scleractinian corals are in high demand for coral reef restoration. However, for threatened reef-building corals, many of the molecular mechanisms related to their reproduction remain largely unknown, which forms a major bottleneck in the large-scale cultivation of sexually reproducing corals. In this study, we analyzed the proteomic signatures of red eggs and spermatozoa from the ecologically significant coral Galaxea fascicularis, using a data-independent acquisition mass spectrometry (DIA-MS) method. A total of 7741 and 7279 proteins from mature red eggs and spermatozoa were identified, respectively. Among these proteins, 596 proteins were spermatozoa-specific and 1056 were egg-specific. Additionally, a total of 4413 differentially abundant proteins (DAPs) were identified, among which 3121 proteins were up-regulated in red eggs and 1292 proteins were up-regulated in spermatozoa. Furthermore, anenrichment analyses showed that DAPs identified in red eggs were mainly involved in the progesterone-mediated oocyte maturation pathway and lectin pathway; and DAPs detected in spermatozoa were mainly involved in the insulin secretion pathway and metabolic pathways for the generation of energy. This result will contribute to the discovery of the intrinsic regulation pathway of gamete maturation and fertilization. Furthermore, at least 57 proteins associated with gamete maturation and reproduction were identified, including the red fluorescent protein (RFP), vitellogenin proteins (VG), the egg protein (EP), the testis-specific serine/threonine-protein kinase family (TSSKs), and the EF-hand Ca²⁺-binding protein family (EFHC1 and EFHC2). Particularly, the third yolk protein EUPHY was reported for the first time in G. fascicularis. In conclusion, this study unveiled groundbreaking molecular insights into coral sexual reproduction, paving the way for more effective conservation and sustainable development of coral reef ecosystems Full article

In the digital economy era, artificial intelligence implementation has accelerated the intellectualization of productive forces, emphasizing the critical relationship between higher education and this transformation. As the primary conduit for developing advanced human capital, the mechanisms through which higher education adapts to and promotes emerging productive forces require systematic examination. This research establishes a theoretical framework demonstrating the synchronous relationship between higher education development and productive force intellectualization, proposing that higher education development provides essential momentum for this transformation. The framework validation employed panel data analysis from 31 Chinese provinces (2012–2022) using fixed-effects (FE) and mediation effect models. The FE model reveals a positive effect coefficient of 1.561 for higher education development on intelligent productive force enhancement (p < 0.01), indicating substantial promotion of productive force intellectualization without saturation effects. Mediation effect analysis confirms the significance of three mediating factors—labor, capital, and technology (p < 0.05)—validating the influence pathways through human capital, material support, and research innovation mechanisms. The research innovation mechanism demonstrates premier efficacy, while material support mechanisms indicate optimization potential. The human capital mechanism, despite its promise, exhibits implementation time lags. These findings suggest prioritizing intelligent technology talent development, enhancing research investment, and strengthening innovation capabilities to advance higher education’s role in productive force intellectualization. Full article

The gut microbiota, a complex ecosystem, is vital to host health as it aids digestion, modulates the immune system, influences metabolism, and interacts with the brain-gut axis. Various factors influence the composition of this microbiota. Enzymes, as essential catalysts, actively participate in biochemical reactions that have an impact on the gut microbial community, affecting both the microorganisms and the gut environment. Enzymes play an important role in the regulation of the intestinal microbiota, but the interactions between enzymes and microbial communities, as well as the precise mechanisms of enzymes, remain a challenge in scientific research. Enzymes serve both traditional nutritional functions, such as the breakdown of complex substrates into absorbable small molecules, and non-nutritional roles, which encompass antibacterial function, immunomodulation, intestinal health maintenance, and stress reduction, among others. This study categorizes enzymes according to their source and explores the mechanistic principles by which enzymes drive gut microbial activity, including the promotion of microbial proliferation, the direct elimination of harmful microbes, the modulation of bacterial interaction networks, and the reduction in immune stress. A systematic understanding of enzymes in regulating the gut microbiota and the study of their associated molecular mechanisms will facilitate the application of enzymes to precisely regulate the gut microbiota in the future and suggest new therapeutic strategies and dietary recommendations. In conclusion, this review provides a comprehensive overview of the role of enzymes in modulating the gut microbiota. It explores the underlying molecular and cellular mechanisms and discusses the potential applications of enzyme-mediated microbiota regulation for host gut health. Full article

This paper presents a low power wideband dB-linear analog baseband (ABB) circuit for a millimeter-wave (mmW) wireless receiver in 40 nm CMOS technology. The proposed ABB system consists of a multi-stage variable gain amplifier (VGA) and a low-pass filter (LPF). The 5-stage VGA is composed of two variable gain units followed by three fixed gain units with DC offset cancellation (DCOC). The first variable gain unit with a self-compensated transistor pair and compact active inductor load is designed for dB-linear functionality and bandwidth extension, respectively. Moreover, a proposed error compensation method is applied to the second cascaded variable gain unit for further dB-linear gain error correction. A 4th-order Butterworth transconductance-capacitance (Gm-C) LPF with flipped source follower (FSF) as an input transconductance stage for linearity enhancement is designed after the VGA stage. The prototype chip is implemented, and measurement results show a dB-linear gain range from −18 to 26 dB with less than 0.5 dB-linear gain error with a bandwidth of 4 GHz. The VGA and LPF consume 8.3 mW and 3 mW, respectively, under a 1 V power supply, while the entire ABB occupies an area of 0.94 mm² with an active core area of only 0.045 mm². Full article

Recently, 7-diethylamino-4-methylcoumarin (DEAMC) has been identified as a potent antiandrogenic compound in the surface water; however, little is known about the antiandrogenic potentials of other synthetic coumarins and their occurrence in the aquatic ecosystem. In this study, for the first time, we observed that 7-dimethylamino-4-methylcoumarin (DAMC) elicited androgen receptor (AR) antagonistic activity with a 50% inhibitory concentration (IC₅₀) of 1.46 µM, which is 14.3 times more potent than that observed for DEAMC (IC₅₀ = 20.92 µM). We further collected abiotic (water and sediment) and biotic (plant, plankton, and fish) samples (n = 208) from a subtropical freshwater ecosystem, the Dongjiang River basin, in southern China, and determined the concentrations of the two coumarins in these samples. Overall, DAMC was the predominant compound found in the sediment, plant, algae, zooplankton, and fish muscle samples, with median concentrations at 0.189, 0.421, 0.832, 0.798, and 0.335 ng/g dry wt. (DW), respectively, although it was not detected in any surface water sample. For DEAMC, the median concentrations observed in the surface water, sediment, plant, algae, zooplankton, and fish muscle samples were 0.105 ng/L, 0.012, 0.051, 0.009, 0.008, and 0.181 ng/g DW, respectively. The bioaccumulation factor (BAF) values of DAMC and DEAMC in the algae, zooplankton, and fish muscle exceeded 5000 L/kg, suggesting that the two coumarins may have significant bioaccumulation potentials in aquatic biota. Additionally, the mean daily intake (EDI) of coumarins through fish consumption was estimated as 0.19 ng/kg BW/day for male toddlers. This is the first field study to illustrate the antiandrogenic potential of DAMC and document the widespread occurrence of the two synthetic coumarins in aquatic ecosystems. Full article

Diacylglycerol (DAG) is a functional oil but is rarely used in the cosmetic industry because low solubility, susceptibility to leakage and low viscosity to skin are still the main hurdles. A novel diacylglycerol nanostructured lipid carrier hydrogel (GTP-DAG-NLC-GEL) loaded with green tea polyphenol (GTP) was designed and successfully prepared to broaden DAG’s application in cosmetics, which significantly improved GTP stability and skin stickiness of DAG. The results showed that DAG-NLC-GEL had good viscosity, which was 980 Pa·s when the shear rate was 5 rpm, and its viscosity decreased quickly with the increase in shear rate, making it easily expand on skin. Meanwhile, the encapsulation rate and drug loading of GTP in GDP-DAG-NLC-GEL reached 86.7% and 2.6%, respectively, and the DPPH free radicals scavenging rate and inhibition rate of the advanced glycation end-products (AGEs) were 85.46% and 89.72%, respectively, which indicate that GTP-DAG-NLC-GEL has significant skin sunscreen, antioxidant and anti-glycation activities. The GTP-loaded nanostructured lipid carrier hydrogel can be deemed to have great prospects for skin protection in cosmetics. Full article

Diagnosing faults in wheelset bearings is critical for train safety. The main challenge is that only a limited amount of fault sample data can be obtained during high-speed train operations. This scarcity of samples impacts the training and accuracy of deep learning models for wheelset bearing fault diagnosis. Studies show that the Auxiliary Classifier Generative Adversarial Network (ACGAN) demonstrates promising performance in addressing this issue. However, existing ACGAN models have drawbacks such as complexity, high computational expenses, mode collapse, and vanishing gradients. Aiming to address these issues, this paper presents the Transformer and Auxiliary Classifier Generative Adversarial Network (TACGAN), which increases the diversity, complexity and entropy of generated samples, and maximizes the entropy of the generated samples. The transformer network replaces traditional convolutional neural networks (CNNs), avoiding iterative and convolutional structures, thereby reducing computational expenses. Moreover, an independent classifier is integrated to prevent the coupling problem, where the discriminator is simultaneously identified and classified in the ACGAN. Finally, the Wasserstein distance is employed in the loss function to mitigate mode collapse and vanishing gradients. Experimental results using the train wheelset bearing datasets demonstrate the accuracy and effectiveness of the TACGAN. Full article

In recent years, pigment rice has been the focus of much attention due to its high nutritional value and ornamental value. To gain a better understanding of pigmented rice, we studied the morphological, physiological, and yield characteristics of four varieties, i.e., light green (LG), deep purple (DP), black-purple (BP), and white rice (WR), as plant material. The field experiment was conducted using a randomized complete block design at Guangdong ocean university research farm during 2023 and 2024. The data of the pigmented rice varieties regarding their morphological, physiological, and antioxidant traits were compared with CK. Leaf area and dry matter accumulation were significantly higher in BP than in the other rice varieties, with BP being the best performer and WR being the worst. The internode length, leaf area, and dry matter accumulation of BP were markedly higher than the rest of the rice varieties. The chlorophyll content of BP was significantly higher. The antioxidant enzyme activities were significantly different among all the varieties. The antioxidant enzyme activities of BP were significantly higher than those of the other rice varieties. Seed yield varied significantly, with BP showing the highest yield. The morphophysiological characteristics of BP and DP suggest that these two varieties can alleviate the response to salinity stress, thereby increasing rice yield. Full article

The rational dietary ratio of docosahexaenoic acid (DHA) to eicosapentaenoic acid (EPA) can exert neurotrophic and cardiotrophic effects on the human body. The marine microalga Nannochloropsis oceanica produces EPA yet no DHA, and thus, it is considered an ideal EPA-only model to pursue a rational DHA/EPA ratio. In this study, synthetic biological strategy was applied to improve EPA production in N. oceanica. Firstly, to identify promoters and terminators, fifteen genes from N. oceanica were isolated using a transcriptomic approach. Compared to α-tubulin, NO08G03500, NO03G03480 and NO22G01450 exhibited 1.2~1.3-fold increases in transcription levels. Secondly, to identify EPA-synthesizing modules, putative desaturases (NoFADs) and elongases (NoFAEs) were overexpressed by the NO08G03500 and NO03G03480 promoters/terminators in N. oceanica. Compared to the wild type (WT), NoFAD1770 and NoFAE0510 overexpression resulted in 47.7% and 40.6% increases in EPA yields, respectively. Thirdly, to store EPA in triacylglycerol (TAG), NoDGAT2K was overexpressed using the NO22G01450 promoter/terminator, along with NoFAD1770–NoFAE0510 stacking, forming transgenic line XS521. Compared to WT, TAG-EPA content increased by 154.8% in XS521. Finally, to inhibit TAG-EPA degradation, a TAG lipase-encoding gene NoTGL1990 was knocked out in XS521, leading to a 49.2–65.3% increase in TAG-EPA content. Our work expands upon EPA-enhancing approaches through synthetic biology in microalgae and potentially crops. Full article

Due to the challenge that the behavior of traffic participants in the driving environment is highly stochastic and uncertain, it is difficult for self-driving vehicles to make accurate decisions based only on the current environmental state. In this paper, we propose a driving strategy learning method based on spatial-temporal feature prediction. Firstly, the spatial interaction between vehicles is implicitly modeled using a graph convolutional neural network and multi-head attention mechanism, and the gated loop unit is embedded to capture the sequential temporal relationship to establish a prediction model incorporating spatial-temporal features. Then, a reinforcement learning-based driving strategy method is constructed using some of the predictive features of the ego-vehicle and surrounding vehicles as predictive state inputs. Finally, based on the real dataset and CARLA simulation platform, the prediction ability of the prediction model and the effectiveness of the prediction-based decision-making model are verified. The simulation results prove that the prediction algorithm can achieve the minimum error compared with the baseline trajectory prediction algorithm, and effectively improves the accuracy and reliability of the autopilot decision-making in various dynamic scenarios. Full article