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991.
992.
Zengqing Sun Qingyu Tang Xiaohui Fan Min Gan Xuling Chen Zhiyun Ji Xiaoxian Huang 《Molecules (Basel, Switzerland)》2022,27(1)
Alkali-activated materials (AAMs) are considered to be alternative cementitious materials for civil infrastructures. Nowadays, efforts have been made in developing AAMs with self-compacting ability. The obtained self-compacting AAMs (SCAAMs) accomplish superior passing and filling properties as well as excellent mechanical and environmental advantages. This work critically revisits recent progresses in SCAAMs including mixture proportions, fresh properties, mechanical strength, microstructure, acid and sulfate resistance, high temperature behaviors, impact resistance and interface shear strength. To facilitate direct comparison and interpretation of data from different publications, mixture proportions were normalized in terms of the content of key reactive components from precursors and activators, and correlation with mechanical behaviors was made. Moreover, special attention was paid to current research challenges and perspectives to promote further investigation and field application of SCAAMs as advanced construction material. 相似文献
993.
Ya Wang Sinan Zhao Tao Guo Li Li Tantan Li Anqi Wang Dandan Zhang Yanlei Wang Yi Sun 《Molecules (Basel, Switzerland)》2022,27(1)
A novel hybrid PKS–NRPS alkaloid, xylarialoid A (1), containing a 13-membered macrocyclic moiety and [5,5,6] fused tricarbocyclic rings, together with ten known cytochalasins (2–11), was isolated from a plant-derived endophytic fungus, Xylaria arbuscula. The chemical structures of all compounds were elucidated using 1D and 2D NMR, HR ESIMS spectroscopic analyses, and electronic circular dichroism (ECD) calculation. Compounds 1–3 and 10 exhibited significant antitumor activities against A549 and Hep G2 cell lines, with IC50 values of 3.6–19.6 μM. In addition, compound 1 showed potent anti-inflammatory activity against LPS-induced nitric oxide (NO) production in macrophage RAW 264.7 cells (IC50, 6.6 μM). 相似文献
994.
Mengdie Gong Mingyan Tu Hongxia Sun Lu Li Lili Zhu Honglin Li Zhenjiang Zhao Shiliang Li 《Molecules (Basel, Switzerland)》2022,27(1)
Huntington’s disease (HD) is a rare single-gene neurodegenerative disease, which can only be treated symptomatically. Currently, there are no approved drugs for HD on the market. Studies have found that MAPK11 can serve as a potential therapeutic target for HD. Regrettably, no MAPK11 small molecule inhibitors have been approved at present. This paper presents three series of compounds that were designed and synthesized based on the structure of skepinone-L, a known MAPK14 inhibitor. Among the synthesized compounds, 13a and 13b, with IC50 values of 6.40 nM and 4.20 nM, respectively, displayed the best inhibitory activities against MAPK11. Furthermore, the structure–activity relationship (SAR) is discussed in detail, which is constructive in optimizing the MAPK11 inhibitors for better activity and effect against HD. 相似文献
995.
The most effective methodologies for the construction of polynuclear complexes usually take advantage of preorganized building blocks.Herein,we successfully developed a new versatile heterometallic{BiNb4}moiety,which can be applied for the assembly of less explored organic-inorganic hybrid polyoxoniobates.Through controlled condensation reactions,three{BiNb4}moieties can be assembled into a pair of isomeric Bi3Nb18clusters at different temperatures;whilst four{BiNb4}moieties can be combined into two unique Bi4Nb16and Bi4Nb18tetramers in different solvents.Interestingly,we have used mass spectrometry to probe the above condensation reactions,which clearly confirmed a stepwise bottom-up assembly process by capturing the presence of bismuth subsalicylate precursors,salicylate coordinated intermediates,Nb incorporated{BiNb4}moieties and the final BixNby-oxo clusters,respectively.Moreover,the packing modes of the{BiNb4}units induce different solution behaviors,and the{BiNb4}units in Bi4Nb16can be recombined by post-synthetic recrystallization in acetonitrile to produce a new tetramer Bi4Nb18-R.Therefore,this work provides not only a useful{BiNb4}building unit but also the mechanism for their condensation,both of which will promote the future development of metal-oxo clusters. 相似文献
996.
Polyamides reinforced with glass fibres are characterised by high values for modulus of elasticity and notched impact strength but also have the negative properties of rough surfaces and anisotropy - particularly anisotropic shrinkage. Mineral-filled polyamides have good surface properties, are isotropic and have high impact strength, however, the elasticity modulus is only slightly better than for normal polyamides and notched impact strength values are relatively low. Through a combination of glass fibres and mineral filler, surface properties can be improved and anisotropy reduced. In order to achieve the optimum mechanical properties a range of 0 - 50 wt.-% glass fibre content and 0 - 40 wt.-% mineral content was systematically examined using statistically designed experiments. This investigation showed the relationship between the “Responses”, surface appearance, shrinkage, modulus of elasticity, impact strength and tensile properties and the “variables”, glass fibre and mineral content. Optimal products, based on the model functions, can be chosen in this way. 相似文献
997.
无水AlCl3催化氯苯胺与丙烯腈的加成反应 总被引:6,自引:0,他引:6
报道了无水AlCl3催化邻、间、对氯苯胺三种异构体与丙烯腈发生催化加成反应生成相应的N_氰乙基邻氯苯胺、N_氰乙基间氯苯胺、N_氰乙基对氯苯胺和N,N_二氰乙基邻氯苯胺、N,N_二氰乙基间氯苯胺、N,N_二氰乙基对氯苯胺。结果表明,AlCl3是一种对该类反应具有高催化活性的催化剂。在较低的温度下,用3%~10%(占氯代苯胺的摩尔百分数,以下同)的AlCl3,主要获得单氰乙基产物,最高收率为88%~92%;在较高的温度下,用30%~100%的AlCl,主要获得二氰乙基产物,最高收率为76%~89%。 相似文献
998.
999.
Runming Wang Jasper Fuk-Woo Chan Suyu Wang Hongyan Li Jiajia Zhao Tiffany Ka-Yan Ip Zhong Zuo Kwok-Yung Yuen Shuofeng Yuan Hongzhe Sun 《Chemical science》2022,13(8):2238
The emergence of SARS-CoV-2 variants of concern compromises vaccine efficacy and emphasizes the need for further development of anti-SARS-CoV-2 therapeutics, in particular orally administered take-home therapies. Cocktail therapy has shown great promise in the treatment of viral infection. Herein, we reported the potent preclinical anti-SARS-CoV-2 efficacy of a cocktail therapy consisting of clinically used drugs, e.g. colloidal bismuth subcitrate (CBS) or bismuth subsalicylate (BSS), and N-acetyl-l-cysteine (NAC). Oral administration of the cocktail reduced viral loads in the lung and ameliorated virus-induced pneumonia in a hamster infection model. The mechanistic studies showed that NAC prevented the hydrolysis of bismuth drugs at gastric pH via the formation of the stable component [Bi(NAC)3], and optimized the pharmacokinetics profile of CBS in vivo. Combination of bismuth drugs with NAC suppressed the replication of a panel of medically important coronaviruses including Middle East respiratory syndrome-related coronavirus (MERS-CoV), Human coronavirus 229E (HCoV-229E) and SARS-CoV-2 Alpha variant (B.1.1.7) with broad-spectrum inhibitory activities towards key viral cysteine enzymes/proteases including papain-like protease (PLpro), main protease (Mpro), helicase (Hel) and angiotensin-converting enzyme 2 (ACE2). Importantly, our study offered a potential at-home treatment for combating SARS-CoV-2 and future coronavirus infections.A cocktail therapy comprising bismuth drugs and N-acetyl-l-cysteine is reported to suppress the replication of SARS-CoV-2 via the oral route. The broad-spectrum inhibitory activities of the combination upon key viral cysteine enzymes are verified. 相似文献
1000.
Paracyclophene based monomers can be polymerized in a living fashion using the alkylidene initiator Mo(NAr)(CHCMe2Ph)(OCMe(CF3)2)2. The cis-specific nature of the polymerization is critical, since small amounts of trans olefin in the backbone renders the material insoluble. These polymers have complex photophysical behavior, probably a consequence of the close proximity of chromophores along the polymer backbone. Polymerization of 9-(tert-butyldimethylsilyloxy)-[2.2]-paracyclophan-1-ene produces a new precursor material which furnishes PPV under remarkably mild conditions. 相似文献