The concept of tourism economic resilience emphasizes the sustainable development level of tourism economy under uncertainty and risk. Focusing on urban agglomerations, this study aims to describe ...how the tourism economic resilience is developing, explore whether the resilience level is enhanced with urban agglomerations and whether spatial elements affect resilience levels. With the combination of the aggregation and diffusion effects and crowding effects of regional development, the study uses a combination of dynamic evaluation method, spatial kernel density, and mathematical models of urban agglomeration development to quantitatively analyze the spatiotemporal dynamic evolution of tourism economic resilience from 2006 to 2019, simulates and verifies its development patterns. The conclusions show that: (1) The tourism economic resilience in urban agglomerations is closely related to regional development and prosperity; (2) The development of tourism economic resilience also follows the spatial economic development pattern which moves towards equilibrium in aggregation process; (3) The tourism economic resilience of urban agglomerations has a fluctuation climbing node, generally presents as a wave-like upward trend with fluctuations and stages; (4) The evolutionary trend of tourism economic resilience in urban agglomerations presents as a slight wave-like upward curve that changes with time and co-opetition.
Diarrhea-predominant irritable bowel syndrome (IBS-D) is one of the most common chronic functional gastrointestinal diseases with limited treatments. Gut microbiota play an important role in chronic ...gastrointestinal diseases. In traditional Chinese medicine (TCM), Spleen-Yang deficiency (SYD) is one of the root causes of IBS-D. Fuzi-Lizhong pill (FLZP) is well known for its powerful capacity for treating SYD and has a good clinical effect on IBS-D. However, the mechanism of FLZP on the gut microbiota of IBS-D has not been fully clarified. Our present study aimed to reveal the mechanism of FLZP regulating gut microbiota of IBS-D. The body mass, CCK, MTL, and Bristol fecal character score were used to verify the establishment of the IBS-D model. IL-6, TNF, IL-1β, and IFN-γ were crucial targets screened by network pharmacology and preliminarily verified by ELISA. Eighteen gut microbiota were important for the treatment of IBS-D with FLZP. Bacteroidetes,
,
, and
were the crucial gut microbiota that FLZP inhibits persistent systemic inflammation in the IBS-D model
is the crucial gut microbiota that FLZP renovates intestinal immune barrier in the IBS-D model. In summary, FLZP can affect bacterial diversity and community structures in the host and regulate inflammation and immune system to treat IBS-D.
In this study, hot deformation behavior of in-situ nanosized TiB2/AZ91 composite is investigated by analyzing the constitutive equation, hot processing maps and microstructure evolutions. Hot ...compression tests are conducted in different temperatures and strain rates range of 523–673 K and 0.001–1 s−1 with a constant strain of 0.69. The results show that deformation temperatures and strain rates have a strong influence on the flow behavior of the composite, exhibiting typical work hardening, softening and steady stages. The constitutive equation is established through determining material constants, which can predict the flow stress precisely. In the meanwhile, the stress exponent (n) is calculated as 5.4, suggesting the hot deformation mechanism of TiB2/AZ91 composite is dominated by the dislocation climb. And the calculated apparent activation energy (Q) is 168.8 kJ/mol, which is higher than that of unreinforced AZ91 alloy due to the addition of nanosized TiB2 particles. Furthermore, the hot processing maps of TiB2/AZ91 composite are developed based on dynamic materials model, presenting three domains: one instability region in the range of 523–623 K & 0.01–1 s−1, and two safe regions in the range of 548–600 K & 0.001–0.005 s−1 and 648–673 K & 0.1–1.0 s−1 with the peak efficiency value of 0.36, respectively. By observing microstructures, full dynamic recrystallization (DRX) occurs in the safe regions, while the mechanism of instability region is dominated by mechanical twining and high density dislocation.
•The deformation mechanism of in-situ nanosized TiB2/AZ91 is clarified.•Constitutive equation of the composite is established.•Hot processing maps of TiB2/AZ91 composite at different strains are developed.•Two optimum processing windows of the composite are identified.
•Yeast β-glucan reduced DSS-induced alterations to architecture of colon mucosa in mice.•Yeast β-glucan aided in the recovery of epithelial barrier function in mice.•Yeast β-glucan diminished the ...DSS-induced expression of inflammatory mediators.•Tight junction proteins involved the protective effect of yeast β-glucan on acute ulcerative colitis in mice.
Ulcerative colitis is a chronic inflammatory disease that is characterized by relapsing inflammation and dysfunction within the gastrointestinal tract. The purpose of this study was to investigate the protective effects of yeast β-glucan on regulating inflammation and disruption of the epithelial barrier in colitis caused by dextran sulfate sodium (DSS). Oral administration of yeast β-glucan reduced clinical symptoms, inflammatory infiltrates and cell apoptosis in the colon epithelium, ameliorated intestinal permeability and the structural integrity of tight junctions. Moreover, treatment with yeast β-glucan not only decreased myeloperoxidase, eosinophil peroxidase and N-acetyl-β-d-glucosaminidase levels, but also modified the immune status characterized by the change in immunoglobulin levels in DSS-treated mice. These results suggest that yeast β-glucan improves DSS-induced changes in mucosal inflammatory lesions and the intestinal barrier by inhibiting the expression of inflammatory mediators and enhancing the expression of tight junction proteins associated with intestinal permeability.
The development of three-photon microscopy (3PM) has greatly expanded the capability of imaging deep within biological tissues, enabling neuroscientists to visualize the structure and activity of ...neuronal populations with greater depth than two-photon imaging. In this review, we outline the history and physical principles of 3PM technology. We cover the current techniques for improving the performance of 3PM. Furthermore, we summarize the imaging applications of 3PM for various brain regions and species. Finally, we discuss the future of 3PM applications for neuroscience.
This paper presents a novel adaptive dynamic programming (ADP) method to solve the optimal consensus problem for a class of discrete‐time multi‐agent systems with completely unknown dynamics. ...Different from the classical RL‐based optimal control algorithms based on one‐step temporal difference method, a multi‐step‐based (also call n‐step) policy gradient ADP (MS‐PGADP) algorithm, which have been proved to be more efficient owing to its faster propagation of the reward, is proposed to obtain the iterative control policies. Moreover, a novel Q‐function is defined, which estimates the performance of performing an action in the current state. Then, through the Lyapunov stability theorem and functional analysis, the proof of optimality of the performance index function is given and the stability of the error system is also proved. Furthermore, the actor‐critic neural networks are used to implement the proposed method. Inspired by deep Q network, the target network is also introduced to guarantee the stability of NNs in the process of training. Finally, two simulations are conducted to verify the effectiveness of the proposed algorithm.
This paper presents a novel adaptive dynamic programming (ADP) method to solve the optimal consensus problem for a class of discrete‐time multi‐agent systems with completely unknown dynamics. Different from the classical RL‐based optimal control algorithms based on one‐step temporal difference method, a multi‐step‐based (also call n‐step) policy gradient ADP (MS‐PGADP) algorithm, which have been proved to be more efficient owing to its faster propagation of the reward, is proposed to obtain the iterative control policies.
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•PSB could release VFAs inhibition and recover biogas production effectively.•PSB bioaugmentation could maintain the microbial diversity of the system.•Light could accelerate the ...consuming speed of VFAs with or without PSB addition.•Adding PSB to release VFAs inhibition might be a cost-effective choice.
The accumulation of volatile fatty acids (VFAs) can decrease reactor pH and inhibit methane-producing process. For the first time, photosynthetic bacteria (PSB) were used to recover from VFAs inhibition (pH 6.0) of an anaerobic digestion system. After adding PSB for 12 days with and without light condition, the methane content recovered from 33.3% to 60.5% and from 32.1% to 59.3%, respectively; the pH increased to 7.1 and 6.8, respectively, the system alkalinity rapidly increased to 2238 and 1921 mg/L, respectively; the sCOD decreased from 5600 to 995 mg/L and from 5575 to 2025 mg/L, respectively; and the contents of formic acid, acetic acid, propionic acid and total VFA were greatly reduced. Microbial analysis found that PSB bioaugmentation could maintain microbial diversity of the system. PSB bioaugmentation could effectively relieve acids accumulation and stimulate methane production especially under light condition. It is also found that light could accelerate recovery with or without bioaugmentation.
In the competitive landscape of online learning, developing robust and effective learning resource recommendation systems is paramount, yet the field faces challenges due to high-dimensional, sparse ...matrices and intricate user–resource interactions. Our study focuses on geometric matrix completion (GMC) and introduces a novel approach, graph-based truncated norm regularization (GBTNR) for problem solving. GBTNR innovatively incorporates truncated Dirichlet norms for both user and item graphs, enhancing the model’s ability to handle complex data structures. This method synergistically combines the benefits of truncated norm regularization with the insightful analysis of user–user and resource–resource graph relationships, leading to a significant improvement in recommendation performance. Our model’s unique application of truncated Dirichlet norms distinctively positions it to address the inherent complexities in user and item data structures more effectively than existing methods. By bridging the gap between theoretical robustness and practical applicability, the GBTNR approach offers a substantial leap forward in the field of learning resource recommendations. This advancement is particularly critical in the realm of online education, where understanding and adapting to diverse and intricate user–resource interactions is key to developing truly personalized learning experiences. Moreover, our work includes a thorough theoretical analysis, complete with proofs, to establish the convergence property of the GMC-GBTNR model, thus reinforcing its reliability and effectiveness in practical applications. Empirical validation through extensive experiments on diverse real-world datasets affirms the model’s superior performance over existing methods, marking a groundbreaking advancement in personalized education and deepening our understanding of the dynamics in learner–resource interactions.
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