386 research outputs found

    Bis(nitrato-κO)(3-oxapentane-1,5-diamine-κ3 N,O,N′)zinc(II)

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    In the title compound, [Zn(NO3)2(C4H12N2O)], the ZnII atom is N,O,N′-chelated by a 3-oxapentane-1,5-diamine ligand and is further coordinated by two nitrate anions in a distorted trigonal–bipyramidal geometry. Inter­molecular N—H⋯O hydrogen bonding is present in the crystal structure. A short O⋯O contact of 2.816 (8) Å is observed between the nitrate anions of adjacent mol­ecules

    Mushroom polysaccharides from Grifola frondosa (Dicks.) Gray and Inonotus obliquus (Fr.) Pilat ameliorated dextran sulfate sodium-induced colitis in mice by global modulation of systemic metabolism and the gut microbiota

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    Introduction: Polysaccharides from Grifola frondosa (Dicks.) Gray (HSH) and Inonotus obliquus (Fr.) Pilat (BHR) showed noticeable effects on dextran sulfate sodium (DSS)-induced colitis, but their systemic modulation effects have not been fully revealed. This study aimed to investigate the regulation of the gut microbiota and systemic metabolism by HSH and BHR in DSS-induced colitis.Methods: C57BL/6J mice were given DSS (2.5%) in water and were treated with HSH and BHR (200 mg/kg/day) by gavage. Body weight and colon length were recorded, and H&E and AB-PAS staining of the colon were conducted to evaluate the model and the protective effect of the polysaccharides. Additionally, an LC-QTOF/MS-based untargeted metabolomic platform was used to identify the metabolites in the serum, colon tissue, gut contents, and faeces and investigate differential metabolites and metabolic pathways. 16S rDNA gene sequencing was used to measure the composition of bacterial communities.Results: The results showed that the mouse colitis model was established successfully, as evidenced by an increased disease activity index score [2.83 ± 0.62 vs. 0.06 ± 0.14 (p < 0.001)] and shortened colon length [5.43 ± 0.64 cm vs. 7.04 ± 0.29 cm (p < 0.001)], and HSH and BHR ameliorated DSS-induced colitis by improving the disease activity index (2.17 ± 0.28 and 1.83 ± 0.29, respectively) and restoring the colon length (6.12 ± 0.30 cm and 6.62 ± 0.35 cm, respectively). HSH and BHR significantly modulated metabolites involved in aromatic amino acid metabolism, the citrate cycle, purine metabolism, pyrimidine metabolism, etc. HSH and BHR increased the Chao1 index by 64.25% and 60.25%, respectively, and they increased the Shannon index by 13.02% and 10.23%, respectively. They both reversed the increase in the abundances of g_Odoribacter, g_Clostridium, g_AF12, g_Parabacteroides and g_Turicibacter and reversed the decrease in the abundance of g_unclassified_Bacteria induced by DSS. Specifically, HSH reversed the reductions in g_unclassified_Lactobacillales and g_Ruminococcus, and BHR reversed the decreases in g_unidentified_Coriobacteriaceae and g_unclassified_Firmicutes.Discussion: These results suggested that HSH and BHR may ameliorate DSS-induced colitis by global modulation of systemic metabolism and the gut microbiota. Targeting the gut microbiota may be a potentially effective strategy to modulate systemic metabolism and treat colitis

    Application comparison of improved endotracheal tube and ordinary endotracheal tube among critically ill patients

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    目的  探讨改良气管导管与传统气管导管优越性比较。方法  对25例需要长期呼吸机支持治疗患者随机分为A、B两组,A组(n=12)使用改良气管导管,B组(n=13)使用传统的气管导管,两组患者分别在留管时间、ICU住院时间、憋气缓解率以及更换气管导管费用方面进行比较。结果  两组患者在GCS评分及留管时间方面无统计学意义,P>0.05,但在更换导管费用、ICU入住时间以及憋气缓解率方面,改良气管导管明显优于传统气管导管,P<0.05。结论  改良气管导管可以大大减少头端贴壁的几率,从而减少重症患者憋气发生,同时可以减少患者入住ICU的时间,大大减少住院费用。Objective: To explore the advantages of improved endotracheal tube and to compare it with traditional endotracheal tube. Methods: 25 patients requiring long-term mechanical ventilation patients were randomly divided into two groups: group A and group B. Group A (n=12) use improved endotracheal tube, and traditional endotracheal tube was used for Group B (n=13). The indwelling time, ICU hospitalization time, suffocation remission rate and replacement cost of the endotracheal tube were respectively compared between two groups. Results: GCS score and indwelling catheter time between two groups have no statistical significance, P > 0.05. Improved tracheal catheter is much better than traditional tracheal catheter with regards to catheter replacement cost, time of ICU stay and remission rate of suffocation, P<0.05. Conclusion: The improvement of the endotracheal tube can greatly reduce the rate of head end to stick wall, thus decreasing occurrence of severe shortness of breath, shortening the stay time of the patients in ICU at the same time, and greatly reducing the cost of hospitalization.

    Tris(1,10-phenanthroline-κ2 N,N′)zinc(II) chloride 2-phenyl-4-selenazole-5-car­box­yl­ate decahydrate

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    The asymmetric unit of the title salt, [Zn(C12H8N2)3](C10H6NO2Se)Cl·10H2O, contains a [Zn(phen)3]2+ cation (phen is 1,10-phenanthroline), uncoordinated chloride and 2-phenyl-4-selenazole-5-carboxyl­ate anions and ten uncoord­in­ated water mol­ecules. The central ZnII ion is six-coordinated by six N atoms from three phen ligands in a distorted octa­hedral geometry. An extensive O—H⋯O, O—H⋯N and O—H⋯Cl hydrogen-bonding network stabilizes the crystal structure

    Secure Mobile Agent from Leakage-Resilient Proxy Signatures

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    A mobile agent can sign a message in a remote server on behalf of a customer without exposing its secret key; it can be used not only to search for special products or services, but also to make a contract with a remote server. Hence a mobile agent system can be used for electronic commerce as an important key technology. In order to realize such a system, Lee et al. showed that a secure mobile agent can be constructed using proxy signatures. Intuitively, a proxy signature permits an entity (delegator) to delegate its signing right to another entity (proxy) to sign some specified messages on behalf of the delegator. However, the proxy signatures are often used in scenarios where the signing is done in an insecure environment, for example, the remote server of a mobile agent system. In such setting, an adversary could launch side-channel attacks to exploit some leakage information about the proxy key or even other secret states. The proxy signatures which are secure in the traditional security models obviously cannot provide such security. Based on this consideration, in this paper, we design a leakage-resilient proxy signature scheme for the secure mobile agent systems

    Randomized Entity-wise Factorization for Multi-Agent Reinforcement Learning

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    Multi-agent settings in the real world often involve tasks with varying types and quantities of agents and non-agent entities; however, common patterns of behavior often emerge among these agents/entities. Our method aims to leverage these commonalities by asking the question: ``What is the expected utility of each agent when only considering a randomly selected sub-group of its observed entities?'' By posing this counterfactual question, we can recognize state-action trajectories within sub-groups of entities that we may have encountered in another task and use what we learned in that task to inform our prediction in the current one. We then reconstruct a prediction of the full returns as a combination of factors considering these disjoint groups of entities and train this ``randomly factorized" value function as an auxiliary objective for value-based multi-agent reinforcement learning. By doing so, our model can recognize and leverage similarities across tasks to improve learning efficiency in a multi-task setting. Our approach, Randomized Entity-wise Factorization for Imagined Learning (REFIL), outperforms all strong baselines by a significant margin in challenging multi-task StarCraft micromanagement settings.Comment: ICML 2021 Camera Read
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