48 research outputs found
Prebiotic Structural Diversity Shapes Gut Microbial Diversity, Community Composition, and Metabolic Activity In Vitro
No full textPrebiotics are selectively utilized substrates that modulate gut microbiota and host health, yet different prebiotic structures may elicit distinct ecological and metabolic responses. In this study, we investigated the effects of five structurally diverse prebiotics—isomaltooligosaccharides (IMO), arabinogalactans (AG), pectin, inulin, and stachyose—on human gut microbiota via a 24 h in vitro anaerobic culture with healthy donors’ gut microbiota. Microbial community dynamics were profiled by 16S rRNA gene sequencing, and short-chain fatty acids (SCFAs) production was analyzed. All treatments resulted in decreased α-diversity compared with baseline, with pectin most effectively preserving microbial richness and evenness, whereas stachyose led to the greatest reduction. Community composition and functional profiles shifted in a substrate-specific manner, with AG promoting Bacteroidaceae, IMO stimulating Lachnospiraceae and Faecalibacterium, and pectin supporting balanced microbial structures and SCFA production. Pectin, IMO, and inulin enhanced butyrate levels, whereas AG and pectin promoted propionate formation. These findings demonstrate that prebiotic structural differences strongly shape gut microbial ecology and metabolism, providing a mechanistic basis for rationally selecting and combining prebiotics to beneficially modulate the gut microbiota
In Silico Screening and Identification of Functional Peptides from Yak Bone Collagen Hydrolysates: Antioxidant and Osteoblastic Activities
No full textCollagen peptides are recognized for their diverse bioactivities; however, efficiently screening potent peptides from hydrolysates remains challenging. This study employed an integrated strategy that combined in silico antioxidant activity prediction and molecular docking to myeloperoxidase (MPO) to screen active peptides derived from yak bone collagen hydrolysates. Focusing on low molecular weight peptides, containing motifs such as GVM, GLP, GPM, and GPQ, we identified nine antioxidant peptides (KC1–KC9). Their activities were validated through in vitro free radical scavenging assays, with peptide KC7 demonstrating superior performance. Furthermore, peptide KC7 promoted proliferation, differentiation, and mineralization in MC3T3-E1 cells by upregulating osteogenic markers such as Runx2 and osteocalcin, modulating the Wnt/β-catenin and PI3K/Akt pathways, and reducing the Bax/Bcl-2 ratio. These results highlight KC7’s dual capacity to mitigate oxidative stress and potentially reduce apoptotic susceptibility, thereby stimulating osteogenesis. This positions peptide KC7 as a promising candidate for bone regeneration and oxidative stress-related disorders. Moreover, this study underscores the effectiveness of integrating computational and experimental approaches for the discovery of multifunctional natural peptides
Unraveling the Osteogenic Activity and Molecular Mechanism of an Antioxidant Collagen Peptide in MC3T3-E1 Cells
No full textBackground: Osteoporosis has become an inevitable health issue with global aging, and the current drug treatments often have adverse side effects, highlighting the need for safer and more effective therapies. Collagen-derived peptides are promising alternatives due to their favorable safety profile and biological activity. This study aimed to investigate the osteogenic and anti-apoptotic properties of collagen peptide UU1 (GASGPMGPR) in addition to its antioxidant activity. Methods: The effects of UU1 were evaluated in MC3T3-E1 cells by assessing osteogenic markers, including alkaline phosphatase (ALP), Cyclin D1, runt-related transcription factor 2 (Runx2), and Akt/β-catenin signaling. Western blot analysis quantified collagen I, osteocalcin, and phosphorylated Akt levels. Anti-apoptotic effects were measured via p-Akt levels and the Bax/Bcl-2 ratio. Computational molecular docking was performed to explore the molecular mechanism of UU1 via its interaction with epidermal growth factor receptor (EGFR) and collagen-binding integrin. Results: UU1 treatment promoted cell differentiation, with elevated ALP, Cyclin D1, Runx2, and Akt/β-catenin signaling. Notably, at 0.025 mg/mL, UU1 upregulated the levels of collagen I, osteocalcin, and phosphorylated Akt by 2.14, 3.37, and 1.95 times, respectively, compared to the control. Additionally, UU1 exhibited anti-apoptotic effects, indicated by increased p-Akt levels and a reduced Bax/Bcl-2 ratio. Molecular docking analysis suggested that UU1 could assist the dimerization of EGFR, facilitating downstream signaling transductions and activating collagen-binding integrin. Conclusions: These findings highlight UU1 as a multifunctional peptide with antioxidant, osteogenic, and anti-apoptotic properties, positioning it as a promising candidate for anti-osteoporosis applications in the food and pharmaceutical industries
Enthronement Etiquette of Abdication in the Wei-Jin and Northern and Southern Dynasties and Sui-Tang Dynasties: Considering Enthronement Place and gaodai jitian as Clues
No full textDuring the abdication rite of the Wei-Jin and Northern and Southern Dynasties, the founding monarchs of the new dynasty usually acceded to the emperor’s throne in the altar place (tanchang 壇場) or the southern suburban altar (nanjiao 南郊) and offered sacrifices to heaven in person. In contrast, the founders of the Sui-Tang Dynasties acceded to the emperor’s throne in the main hall (zhengdian 正殿), and no longer offered sacrifices to heaven in person, but sent an agent whose role was to worship heaven. Although in certain cases researchers have mentioned this change, it is mainly investigated from the aspect of etiquette, especially the change of enthronement etiquette and the normalization of vicarious conduct (yousi sheshi 有司攝事). Therefore, it is necessary to discuss this topic from different perspectives.
This study explores the reasons for the changes in enthronement etiquette of abdication in the Wei-Jin and Northern and Southern Dynasties and Sui-Tang Dynasties. Consequently, it analyzes the location of the Chancellor of State’s residence (xiangguo fu 相國府), those who received abdication (shoushan zhe 受禪者) in Wei-Jin and Northern and Southern Dynasties and Sui-Tang Dynasties, as well as the relevant political situation in the Sui-Tang Dynasties at the time of abdication, further clarifying the influence of factors, other than the ritual system, on the formation and change of the enthronement ceremony. Therefore, this study investigates the effects of two aspects, namely, the location of enthronement and the executor of the proclamation to heaven, on dynastic change (gaodai jitian 吿代祭天) at that time.
We find that the changes in the enthronement etiquette of the Sui-Tang Dynasties’ founding monarch are not caused primarily by the internal ceremony system, but by an expedient measure based on the location of the Chancellor of State’s residence and the political situation at the time. Therefore, this directly reflects the difference in abdication between the Wei-Jin and Northern and Southern Dynasties and Sui-Tang Dynasties. Moreover, even though the executor of gaodai jitian changed from emperor to agent during the Sui-Tang Dynasties, Yang Jian 楊堅 and Li Yuan 李淵 took an extremely cautious attitude about the selection of the agent on the day of the ceremony.journal articl
The bioenergetics response of the coral Pocillopora damicornis to temperature changes during its reproduction stage
No full textSexual reproduction of reef–building corals is vital for coral reef ecosystem recovery. Corals allocate limited energy to growth and reproduction, when being under environmental disturbance, which ultimately shapes the community population dynamics. In the present study, energetic and physiological parameters of both parental colonies and larvae of the coral Pocillopora damicornis were measured during their reproduction stage under four temperatures; 28 °C (low–temperature acclimation, LA), 29 °C (control temperature, CT), 31 °C (high–temperature acclimation, HA), and 32 °C (heat stress, HS). The results showed temperature changes altered the larvae release timing and fecundity in P. damicornis. Parental colonies exposed to the LA treatment exhibited reduced investment in reproduction and released fewer larvae, while retaining more energy for their development. However, each larva acquired higher energy and symbiont densities enabling survival through longer planktonic periods before settlement. In contrast, parental colonies exposed to the HA treatment had increased investment for reproduction and larvae output, while per larva gained less energy to mitigate the threat of higher temperature. Furthermore, the energy allocation processes restructured fatty acids concentration and composition in both parental colonies and larvae as indicated by shifts in membrane fluidity under adaptable temperature changes. Notably, parental colonies from the HS treatment expended more energy in response to heat stress, resulting in adverse effects, especially after larval release. Our study expands the current knowledge on the energy allocation strategies of P. damicornis and how it is impacted by temperature. Parental colonies employed different energy allocation strategies under distinct temperature regimes to optimize their development and offspring success, but under heat stress, both were compromised. Lipid metabolism is essential for the success of coral reproduction and further understanding their response to heat stress can improve intervention strategies for coral reef conservation in warmer future oceans.</p
Second-harmonic generation within a random fiber laser
No full textOptical fibers offer convenient access to a variety of nonlinear phenomena. However, due to their inversion symmetry, second-order nonlinear effects, such as second-harmonic generation (SHG), are challenging to achieve. Here, all-fiber in-core SHG with high beam quality is achieved in a random fiber laser (RFL). The fundamental wave (FW) is generated in the same RFL. The phase-matching condition is mainly achieved through an induced periodic electric field and the gain is enhanced through the passive spatiotemporal gain modulation and the extended fiber. The conversion needs no pretreatment and the average second-harmonic (SH) power reaches up to 10.06 mW, with a corresponding conversion efficiency greater than 0.04%. Moreover, a theoretical model is constructed to explain the mechanism and simulate the evolution of the SH and FW. Our work offers a simple method to generate higher brightness for in-fiber SHs, and may further provide new directions for research on all-fiber χ
(2)-based nonlinear fiber optics and RFLs
A New Strategy to Improve the Toughness of Epoxy Thermosets—By Introducing Poly(ether nitrile ketone)s Containing Phthalazinone Structures
No full textAs high brittleness limits the application of all epoxy resins (EP), here, it can be modified by high-performance thermoplastic poly(ether nitrile ketone) containing phthalazinone structures (PPENK). Therefore, the influence of different PPENK contents on the mechanical, thermal, and low-temperature properties of EP was comprehensively investigated in this paper. The binary blend of PPENK/EP exhibited excellent properties due to homogeneous mixing and good interaction. The presence of PPENK significantly improved the mechanical properties of EP, showing 131.0%, 14.2%, and 10.0% increases in impact, tensile, and flexural strength, respectively. Morphological studies revealed that the crack deflection and bridging in PPENK were the main toughening mechanism in the blend systems. In addition, the PPENK/EP blends showed excellent thermal and low-temperature properties (−183 °C). The glass transition temperatures of the PPENK/EP blends were enhanced by approximately 50 °C. The 15 phr of the PPENK/EP blends had a low-temperature flexural strength of up to 230 MPa, which was 46.5% higher than EP. Furthermore, all blends exhibited better thermal stability
Bile salt hydrolase acyltransferase activity shapes bile acid diversity and biochemistry
No full textSupplemental figures from "Bile salt hydrolase acyltransferase activity expands bile acid diversity" by Guzior et al
