Effect of juglone on immunity response and oxidative stress in mice

To research juglone's immunology regulation, several perspectives including immunology regulation, lymphocyte proliferation, and cytokines were presented.The index of thymus and spleen, total supperoxide dismutase activity (T-SOD), serum malondialdehyde (MDA), content of nitrogen oxide (NO), the anti-superoxide anion ability, the suppressing hydroxy radical ability, contents of reduced glutathione (GSH) in thymus, total antioxidationability (T-AOC) and the level of mouse lysozyme (LZM) in plasma were measured. LPS-induced B thymocytes proliferation was measured by MTT assay.In the low-immunity model group, MDA and NO levels were decreased (p<0.001). Juglone improved lysozyme (LZM), GSH contents in thymus, T-AOC, T-SOD activity, the anti-superoxide anion ability (anti- O2-) (p<0.001).In the stimulation immunity model group, MDA and NO levels (p<0.05), anti- O2- and T-SOD activity (p<0.05) were up-regulated, whereas LZM, T-AOC contents were down-regulated.juglone has a significant effect, which promotes cell regeneration and function recovery, also may alleviate oxidative damage; juglone possesses a dual regulating effect on humoral immunity in mice.     

改性超细炭黑诱发氧化应激的毒性效应与机理

为研究改性超细炭黑(modified ultrafine carbon black, MCB)诱发氧化应激的毒性效应与机理,将小鼠肝细胞和过氧化氢酶(catalase, CAT)暴露于不同质量浓度的MCB溶液中。采用CCK-8、丙二醛(malondialdehyde, MDA)含量和CAT活力检测等方法评价MCB的细胞毒性;利用荧光光谱,紫外-可见吸收光谱,圆二色谱等方法探究MCB对CAT构象的影响。结果表明:细胞活力随MCB质量浓度的升高而降低,低质量浓度的MCB(< 30 mg/L)刺激细胞提高CAT的活力来保护自身免受氧化损伤,高质量浓度的MCB(>30 mg/L)使MDA在细胞内累积并造成氧化还原失衡,造成肝脏的氧化损伤;光谱学研究发现, MCB会改变CAT的二、三级结构和氨基酸微环境,使肽链紧缩极性增强,骨架结构的变化降低了CAT的活性。阐明MCB造成氧化应激效应的毒性机理,同时为纳米材料的毒理研究提供了参考。     

Experimental study on the mechanical and failure behaviors of deep rock subjected to true triaxial stress: A reviewOA

It has become an inevitable trend of human development to seek resources from the deep underground.However, rock encountered in deep underground engineering is usually in an anisotropic stress state(σ₁>σ>σ₃) due to the influences of geological structures and engineering disturbances. It is therefore essential to study the mechanical, seepage, and dynamic disaster behaviors of deep rock under true triaxial stress to ensure the safe operation of deep rock engineering an...     

A causation mechanism for coal bursts during roadway development based on the major horizontal stress in coal: Very specific structural geology causing a localised loss of effective coal confinement and Newton's second law

In 2017, one of the international authorities on coal bursts, Mark Christopher, published a paper entitled‘‘Coal bursts that occur during development: A rock mechanics enigma, in which several relevant technical issues were identified. This paper outlines what is considered to be a credible, first-principles,mechanistic explanation for these three current development coal burst conundrums by reference to early published coal testing work examining the significance of a lack of ‘‘constraint to coal stability and an understanding of how very specific structural geology and other geological features can logically cause this to occur in situ, albeit on a statistically very rare basis. This basic model is examined by reference to published information pertaining to the development coal-burst that occurred at the Austar Coal Mine in New South Wales, Australia, in 2014 and from the Sunnyside District in Utah, the United States.The ‘‘cause and effect model for development of coal bursts presented also offers a meaningful explanation for the statistical improbability for what are nonetheless potentially highly-destructive events, being able to explain the statistical rarity being just as important to the credibility of the model as explaining the local conditions associated with burst events. The model could also form the basis for a robust, riskbased approach utilising a ‘‘hierarchy of controls, to the operational management of the development coal burst threat. Specifically, the use of pre-mining predictions for likely burst-prone and non-burstprone areas, the use of the mine layout to avoid or at least minimise mining within burst-prone areas if appropriate, and finally the development of an operational Trigger Action Response Plan(TARP) that reduces the likelihood of inadvertent roadway development into a burst-prone area without suitable safety controls already being in place.