Sugarcane leaves-derived polyphenols alleviate metabolic syndrome and modulate gut microbiota of ob/ob mice

Sugarcane leaves-derived polyphenols(SLP)have been demonstrated to have diverse health-promoting benefits,but the mechanism of action has not been fully elucidated.This study aimed to investigate the anti-metabolic disease effects of SLP and the underlying mechanisms in mice.In the current study,we prepared the SLP mainly consisting of three flavonoid glycosides,three phenol derivatives,and two lignans including one new compound,and further demonstrated that SLP reduced body weight gain and fat accumulation,improved glucose and lipid metabolism disorders,ameliorated hepatic steatosis,and regulated short-chain fatty acids(SCFAs)production and secondary bile acids metabolism in ob/ob mice.Notably,SLP largely altered the gut microbiota composition,especially enriching the commensal bacteria Akkermansia muciniphila and Bacteroides acidifaciens.Oral gavage with the above two strains ameliorated metabolic syndrome(MetS),regulated secondary bile acid metabolism,and increased the production of SCFAs in high-fat diet(HFD)-induced obese mice.These results demonstrated that SLP could be used as a prebiotic to attenuate MetS via regulating gut microbiota composition and further activating the secondary bile acids-mediated gut-adipose axis.

Targeting oxidative stress with natural products: A novel strategy for esophageal cancer therapy

Esophageal cancer(ESC)is a malignant tumor that originates from the mucosal epithelium of the esophagus and is part of the digestive tract.Although the exact pathogenesis of ESC has not been fully elucidated,excessive oxidative stress is an important characteristic that leads to the development of many cancers.Abnormal expression of several proteins and transcription factors contributes to oxidative stress in ESCs,which alters the growth and proliferation of ESCs and promotes their metastasis.Natural compounds,including alkaloids,terpenes,polyphenols,and xanthine compounds,can inhibit reactive oxygen species production in ESCs.These compounds reduce oxidative stress levels and subsequently inhibit the oc-currence and progression of ESC through the regulation of targets and pathways such as the cytokine interleukins 6 and 10,superoxide dismutase,the NF-+ACY-kappa+ADs-B/MAPK pathway,and the mammalian Nrf2/ARE target pathway.Thus,targeting tumor oxidative stress has become a key focus in anti-ESC therapy.This review discusses the potential of Natural products(NPs)for treating ESCs and summarizes the application prospects of oxidative stress as a new target for ESC treatment.The findings of this review provide a reference for drug development targeting ESCs.Nonetheless,further high-quality studies will be necessary to determine the clinical efficacy of these various NPs.

纳米粒子和钢纤维增强混凝土抗冲击性能研究

通过落锤冲击试验,得到了纳米粒子和钢纤维增强混凝土的初裂冲击次数、破坏冲击次数和冲击能差,并以这3个参数作为评价指标,研究纳米SiO_(2)粒子和钢纤维对混凝土抗冲击性能的影响。结果表明,在一定掺量范围内,随着纳米SiO_(2)掺量的增加,混凝土的初裂冲击次数、破坏冲击次数和冲击能差呈现先增大后减小的趋势,当纳米SiO_(2)掺量为2%时,混凝土的抗冲击性能表现最好。在本文试验钢纤维掺量范围内,随着钢纤维掺量的增加,混凝土的初裂冲击次数、破坏冲击次数和冲击能差先增大后减小,当钢纤维掺量为2%时,混凝土的抗冲击性能表现最为优越。掺纳米SiO_(2)的混凝土在冲击破坏时仍表现为脆性破坏,而钢纤维的掺加使混凝土在破坏时表现出了一定的韧性。本文试验所得到的混凝土抗冲击性能规律为纳米SiO_(2)粒子和钢纤维增强混凝土的应用提供了参考。

城市更新规划中的社区能力构成研究--以英格兰新地方主义邻里规划为例

城市更新于规划中越来越强调自下而上的多元主体参与模式,当前城市更新逐渐由公私合营(PPP)模式向“公-私-社区及三方”(PPCt)合作模式转变。社区成为第三方,拥有了更高的话语权。但落实这一模式,不仅依靠规划权力的下放和对公众参与的强调,社区能否有自己足够的能力承接放权之后所得到的话语权,将成为是否能够有效实现多元主体参与的另一决定因素。英国在规划权力下放的地方主义背景下,邻里规划制度作为多元主体参与的具体执行方式在运行十年后已经相对成熟,但依旧存在城市地区社区发展差异问题。本文对英格兰大都市地区邻里论坛领导的邻里规划项目的各项社区能力在规划中的具体情况进行分析。同时参照Beckley等人提出的社区能力在时间维度上的反馈模式,增加了对社区在邻里规划过程中的能力的动态变化情况的讨论。研究发现,在新一轮城市治理的创新中,社区的社会历史经济情况以及社区能力是社区能够真正形成PPCt模式中“社区方”的基础。同时资金支持、各政府规划部门的协作能促进社区的内生能力的建设和发展。通过总结英国邻里规划中社区的构成特点,本文弥补中国城市更新模式转型中对社区这一利益方讨论的不足,并为国内明确社区角色、能力构成,进而提高居民社区规划参与度提供参考。

互联网时代下城市空间品质提升与特色保护

在本次对谈中,三位学者针对当今互联网时代及存量更新背景下中国城市更新中存在的现象和问题进行了深入探讨。首先,三位学者对影响城市空间品质的要素进行了剖析,强调城市更新实践应注重城市空间的社会性、文化性、艺术性、历史性及生态性,并指出了未来城市更新的研究与实践重点,尤其强调了审美启智的重要性。随后,三位学者认为,在"眼球经济"的影响下,时下出现的空间改造"网红化"、城市特色"符号化"等现象可能会引发新一轮的城市同化,以致多元化特色逐渐消失;但城市规划师与设计师也可以对这些网络传播渠道和力量进行正向利用,以实现空间特色保护,甚或引导产生新的城市空间发展范式。此外,他们一致认为,在城市更新过程中民众应享有更大的话语权,这不仅要依靠"共同缔造"的规划模式,更需要设计师承担起深入研究与科普启蒙的重任。最后,三位学者结合具体案例,阐述了城市历史地段改造所面临的诸多挑战,例如城市治理方法落后、城市开发制度存在缺陷、经济发展放缓导致资金受限等,并同时呼吁设计师从中发掘机遇,在满足居民日常生活需求、完善城市治理体系、优化城市更新机制、推动地方经济增长等核心话题层面上持续进行积极探索与创新。

Reconstitution of biosynthetic pathway for mushroom-derived cyathane diterpenes in yeast and generation of new“non-natural”analogues

Mushroom-derived cyathane-type diterpenes possess unusual chemical skeleton and diverse bioactivities.To efficiently supply bioactive cyathanes for deep studies and explore their structural diversity,de novo synthesis of cyathane diterpenes in a geranylgeranyl pyrophosphate engineered Saccharomyces cerevisiae is investigated.Aided by homologous analyses,one new unclustered FAD-dependent oxidase EriM accounting for the formation of allyl aldehyde and three new NADP(H)-dependent reductases in the biosynthesis of cyathanes are identified and elucidated.By combinatorial biosynthetic strategy,S.cerevisiae strains generating twenty-two cyathane-type diterpenes,including seven"unnatural"cyathane xylosides(12,13,14a,14b,19,20,and 22)are established.Compounds 12-14,19,and 20 show significant neurotrophic effects on PC 12 cells in the dose of 6.3-25.0μmol/L.These studies provide new insights into the divergent biosynthesis of mushroom-originated cyathanes and a straightforward approach to produce bioactive cyathane-type diterpenes.

Organosilicon-group-derived silica-ionogel electrolyte for lithium ion batteries

In order to avoid leakage problem caused by liquid electrolyte, a new ionogel electrolyte was developed by in situ immobilizing organosilicon-functionalized ionic liquid within a nanoporous silica matrix. The ionic liquid evenly coats on the surface of porous silica and fills in the silica framework pores with no strong chemical interaction. The ionogel electrolyte has the dual advantages of a silica solid support and a wide electrochemical stability window of ionic liquid （4.87 V vs. Li^＋/Li）. The half-cells assembled with this electrolyte and LiFePO4 electrode have excellent performance at room temperature and 60 ℃. The Li/SiO2-IGE/LiFePO4 cell displays a discharge capacity of 129.1 mAh·g^-1 after 200 charge/discharge cycles at room temperature.

Making comparable measurements of bacterial respiration and production in the subtropical coastal waters

Accurate estimates of bacterial carbon metabolic rates are indispensable for understanding the regulation of carbon fluxes in aquatic environments.Here,changes in bacterial growth,production,and cell volume in both pre-filtered and unfiltered seawater during 24 h incubation were monitored.The methodological artifacts during Winkler bacterial respiration(BR)measurements in subtropical Hong Kong coastal waters were assessed.Bacterial abundance increased by 3-and 1.8-fold in the pre-filtered and unfiltered seawater after incubation,respectively.Bacterial production(BP)and cell volume also showed significant enhancement.Compared with the BR measurements obtained by the Winkler method,the instantaneous free-living BR measurements,after correction,decreased by~70%.The time-integrated free-living BR and BP during 24 h incubation in the pre-filtered sample provided an improved estimate of bacterial growth efficiency,which increased by~52%compared to the common estimations using the noncomparable measurements of integrated free-living BR and instantaneous total BP.The overestimation of BR also exaggerated the contribution of bacteria to community respiration,affecting the understanding on the metabolic state of the marine ecosystems.Furthermore,the BR estimates by the Winkler method may be more biased in environments with a higher bacterial growth rate and tightly coupled grazing mortality,as well as in those with higher nutrient concentrations.These results reveal obvious problems associated with the BR methodology and raise a warning for caution when comparing BP and BR,as well as when making estimations of carbon flow through the complex microbial networks in aquatic ecosystems.