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•Snow chrysanthemum polysaccharides (JHP) could be partially digested during in vitro digestion.•The indigestible JHP could be further degraded and consumed by gut microbiota.•Changes ...of physicochemical properties of JHP during digestion and fermentation were revealed.•Beneficial bacteria, such as Bifidobacterium and Lactobacillus, significantly increased.•The SCFAs, such as acetic, propionic, and n-butyric acids, significantly increased.
The in vitro simulated saliva-gastrointestinal digestion and human fecal fermentation of snow chrysanthemum polysaccharides (JHP) were investigated. Results showed that reducing sugar contents of JHP increased during the gastrointestinal digestion, and glucose released with the decrease of its molecular weight, suggesting that JHP could be partially degraded under the gastrointestinal digestion. Furthermore, after in vitro fecal fermentation, the molecular weight and molar ratio of constituent monosaccharides (galactose and galacturonic acid) of the indigestible JHP (JHP-I) significantly decreased, and both monosaccharides and oligosaccharides released, suggesting that JHP-I could be further degraded and consumed by gut microbiota. Some beneficial bacteria, such as genera Bifidobacterium, Lactobacillus, Megamonas, and Megasphaera, significantly increased, suggesting that JHP-I could change the composition and abundance of gut microbiota. These results suggest that JHP is a potential source of prebiotics, and can be helpful for better understanding of the potential digestion and fermentation mechanism of JHP.
The purpose of this study was to better understand the chemical characteristics and chain conformation of okra polysaccharides extracted by ultrasonic-assisted extraction. A pectic-polysaccharide, ...named OPP-D, was obtained, which was mainly composed of rhamnose, galacturonic acid, and galactose with a molar ratio of 1.01:1.00:2.31. Combined with NMR analysis, -4)-α-d-GalA
-(1,2,4)-α-l-Rha
-(1- were identified as the backbone with galactan side chains substituted partly at O-4 of Rha
. Molecular weight and radius of gyration of OPP-D were determined as 2.19 × 10
Da and 27.0 nm, respectively. OPP-D was determined as an air-core sphere with branching chains in 0.9% NaCl solution by high-performance size-exclusion chromatography coupled with multi-angle laser light scattering and dynamic light scattering for the first time. Moreover, OPP-D exhibited typical shear-thinning behavior. In addition, OPP-D exhibited remarkable in vitro antioxidant activities and prebiotic activities, while the relatively high molecular weight, high degree of esterification, high content of uronic acids, and highly branched globular conformation of OPP-D might contribute to its in vitro anti-diabetic activities and binding capacities. Results can contribute to a better understanding of the structure-bioactivity relationship of OPPs, and OPP-D has great potential applications in the functional food and pharmaceutical industries.
The impacts of three extraction techniques, including hot water extraction (HWE), pressurized water extraction (PWE), and microwave assisted extraction (MAE), on the physicochemical characteristics, ...antioxidant activities, in vitro binding properties, and in vitro inhibitory activities on α-amylase and α-glucosidase of okra polysaccharides (OPPs) were investigated and compared. The extraction yields, constituent monosaccharides, and FT-IR spectra of OPP-W, OPP-P, and OPP-M extracted by HWE, PWE, and MAE, respectively, were similar. However, their molecular weights, intrinsic viscosities, uronic acids, and degree of esterification were different. Furthermore, results showed that OPP-W, OPP-P, and OPP-M exhibited remarkable antioxidant activities, binding capacities, and inhibitory activities on α-amylase and α-glucosidase. Indeed, the antioxidant activities of OPP-W were significantly lower than those of OPP-M and OPP-P, which might be attributed to the low molecular weights and high contents of unmethylated galacturonic acid of OPP-P and OPP-M. However, the binding capacities and inhibitory activities on α-amylase and α-glucosidase of OPP-W and OPP-P were similar, but significantly higher than those of OPP-M, which might be attributed to the low molecular weights of OPP-M. Results suggested that the PWE method could be a good potential technique for the extraction of OPPs with high bioactivities for industrial applications.
•Three techniques (HWE, PWE, and MAE) were used to extract okra polysaccharides (OPPs).•Different extraction techniques affected the chemical structures of OPPs.•Bioactivities of OPPs were closely correlated to their molecular weights.•OPP-P extracted by the PWE method exerted better bioactivities.•PWE could be a good potential technique for OPPs extraction.
Ultrathin Bi2S3 nanosheets with thicknesses down to 2.2 nm are fabricated. The resultant ultrathin Bi2S3‐based photoconductor shows high sensitivity to visible–near infrared light from 405 to 780 nm ...with a high external photoresponsivity up to 4.4 A W−1, high detectivity of ≈1011 Jones, relatively fast response time of ≈10 μs, and high flexibility and durability.
This paper proposes a bi-level branch-and-bound ((B&B) method to solve the economic dispatch problem with prohibited zones and network losses. The approach employs binary variables for each ...prohibited zone and utilizes the B-coefficient for network losses, which can be transformed into a mixed-integer quadratically constrained quadratic programming (MIQCQP), where linear relaxation technique is applied on each bilinear term. Due to the complexity in solving the MIQCQP problem, this paper proposes a bi-level B&B method to achieve global optimum. A spatial B&B method is utilized in the higher level to solve the quadratically constrained quadratic programming (QCQP) problem, whereas a simple B&B method is employed in the lower level to solve a mixed-integer quadratic programming (MIQP) problem. The bi-level B&B algorithm that combines spatial and simple B&B methods is actually a deterministic optimization method and can produce global optimal solutions. Numerical results on 6-unit, 15-unit, and 40-unit test systems show that the bi-level B&B method can solve the MIQCQP problem with superior solution quality and convergence characteristics.
In this study, the microbial fermentation characteristics of okra pectic-polysaccharide (OPP) and its degraded products (DOPP-1 and DOPP-3) with different molecular weights (Mw) and degrees of ...branching (DB) were investigated, and related impacts on gut microbial composition were also revealed. Results indicated that microbial fermentation characteristics of OPP were obviously affected by its different structural features. The fermentabilities of OPP (high Mw and DB), DOPP-1 (middle Mw and DB), and DOPP-3 (low Mw and DB) were measured to be 49.49%, 58.34%, and 48.16%, indicating that the utilization of total carbohydrates of DOPP-1 was relatively higher compared to OPP and DOPP-3. The ways in which gut bacteria metabolized OPP, DOPP-1 and DOPP-3 were quite different, and a lower Mw and a higher DB were more beneficial to the fermentation by intestinal bacteria. Additionally, selective modulations of gut microbial composition by different types of okra pectic-polysaccharides were observed. Both OPP and DOPP-1 could increase relative abundances of several beneficial bacteria, such as Bacteroides and Phascolarctobacterium. While DOPP-3 could notably improve relative abundances of Megasphaera and Megamonas. Results suggested that the modulation of gut microbiota by okra pectic-polysaccharide was structure-dependent, and both DB and Mw played critical roles in the selective modulation of gut microbial composition. Collectively, our findings are beneficial to revealing the potential relationship between chemical structures of OPP and its gut microbial fermentation characteristics, which are also helpful for the design of potential OPP for selective modulation of beneficial bacteria in the gut.
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•Microbial fermentation characteristics of okra pectic-polysaccharide (OPP) were studied.•Molecular weight (Mw) and branched chain notably affected its fermentation characteristics.•A lower Mw and a higher degree of branching are more beneficial to the fermentation.•OPP and its degraded products could selectively modulate the microbial composition.•The modulation of gut microbial composition by OPP is structure-dependent.
Gastric cancer is the fifth most common cancer, and the third most prevalent cause of cancer-related deaths in the world. Voluminous evidence has demonstrated that phytochemicals play a critical role ...in the prevention and management of gastric cancer. Most epidemiological investigations indicate that the increased intake of phytochemicals could reduce the risk of gastric cancer. Experimental studies have elucidated the mechanisms of action, including inhibiting cancer cell proliferation, inducing apoptosis and autophagy, and suppressing angiogenesis as well as cancer cell metastasis. These mechanisms have also been related to the inhibition of
and the modulation of gut microbiota. In addition, the intake of phytochemicals could enhance the efficacy of anticancer chemotherapeutics. Moreover, clinical studies have illustrated that phytochemicals have the potential for the prevention and the management of gastric cancer in humans. To provide an updated understanding of relationships between phytochemicals and gastric cancer, this review summarizes the effects of phytochemicals on gastric cancer, highlighting the underlying mechanisms. This review could be helpful for guiding the public in preventing gastric cancer through phytochemicals, as well as in developing functional food and drugs for the prevention and treatment of gastric cancer.
Fluid-solid coupling is a common phenomenon in the studies of granular materials, geotechnical engineering and so on. Based on a multiphase fluid model in the framework of lattice Boltzmann method ...(LBM) and the discrete element method (DEM), a multiphase fluid-solid coupling algorithm of LBM-DEM is proposed, where the coupling module is developed on the basis of two open-source codes, Palabos and Yade. The feasibility and accuracy of the algorithm are validated through three classical fluid-solid coupling examples: a single sphere settling in a fluid, a sphere falling into a fluid from the air and two spheres colliding with each other in fluid. Then two complex phenomena in geotechnical engineering, transient-state flow and debris flow, are simulated. The results indicate that the LBM-DEM coupled method has strong advantages in the numerical simulation of complex fluid-solid coupling problems. It can accurately reveal the fluid-solid interaction mechanisms, physical & mechanical behaviors and failure process at both macroscopic and mesoscopic scales. Furthermore, from the numerical simulation results, the process of debris flow can be divided into three stages: steady seepage stage, startup stage and flow stage of the fluid-solid mixture.
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•A multiphase fluid-solid coupling algorithm of LBM-DEM is proposed.•The feasibility and accuracy of the algorithm are validated through two classical fluid-solid coupling examples.•As complex applications, two complex phenomena in geotechnical engineering are simulated.•The analysis results provide evidences and insights into the mechanism of fluid-solid coupling.•Based on the numerical results, the process of debris flow can be divided into three stages.
Distribution service restoration (DSR) is critical for improving the resilience and reliability of modern distribution systems by strategically and sequentially energizing the system components and ...customer loads. Restoring electricity service to affected customers also requires multiple crews with different skill sets to perform multiple tasks that are procedurally interdependent with safety guaranteed. However, in existing DSR practices, switch operations and crew dispatch are scheduled separately, and their interdependence is not fully considered. As advanced technologies are enabling remote communication, control, and dispatch, utilities now desire an integrated DSR framework to achieve seamless coordination among multiple DSR tasks such as switch operation, crew dispatch, and component repair. In this paper, we introduce a synthetic model that integrates the service restoration model and the crew dispatch model based on a universal routing model. The proposed model can provide the estimated time of restoration for each load, the switching sequence for safely operating remotely/manually operated switches, and dispatch solutions for crews with different skill sets. The proposed synthetic model is formulated as a mixed-integer linear programming model, and its effectiveness is evaluated via the IEEE 123 bus test feeder and several large-scale test feeders (EPRI Ckt5, Ckt7, Ckt24, and IEEE 8500 node test feeder.
In this study, based on Smoothed Particle Hydrodynamics (SPH) and Discrete Element Method (DEM), a multiphase fluid-solid coupling algorithm of SPH-DEM is provided, and a high performance coupling ...module is developed based on two open-source software platforms, namely: DualSphysics for SPH and Blaze-DEM for DEM. With a comparative analysis of three typical tests, it is systematically proved that the developed coupling module can feasibly and precisely tackle the complex coupling between solid particles and fluid. Moreover, based on the test results of single particle sedimentation and water-entry of spinning spheres, three water-entry stages of the spheres are characterized: contact and shockwave generation, cavity formation and water splashing, and cavity closure and collapse. As a complex problem, the submerged granular collapse is simulated, and according to the numerical results the process of granular collapse can be divided into four stages: beginning, collapsing, decelerated sliding and stable sedimentation. The granular aggregation can be partitioned into the zones of flowing, sliding, shearing, and relatively standstill particles by the motion characteristics of different parts of particles on different stages. In addition, the macro- and meso-characteristics of the process of granular collapse are also discussed. According to the research results of this study, the developed SPH-DEM module can better simulate the complex coupling process between fluid and granular materials. Furthermore, with more information obtainable, numerical simulation is important to get insight into this process.
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•The SPH and DEM coupling routines are presented.•A 3D SPH-DEM coupling engine is developed based on two open source codes.•Three typical tests have been used to validate the coupling engine of SPH-DEM.•The water-entry of a single sphere can be divided into three water-entry stages.•The submerged granular collapse is simulated and the process of the collapse are discussed at macro- and meso-scale.
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