Carbon black-benzo(a)pyrene complex-induced apoptosis and autophagy blockage in rat alveolar macrophages

Abstract

Cooking of foods and the burning of biomass and fossil fuels in stoves are the main sources of cooking fumes, with carbon black and polycyclic aromatic hydrocarbons as main components. The toxicity of carbon black and polycyclic aromatic hydrocarbons has been well studied individually, but the combined toxicity is much less understood. Carbon black can adsorb benzo(a)pyrene to form a complex which displays an altered physical form which in this study has been constructed to simulate particles in the cooking fumes and explore the combined toxic effect on rat alveolar macrophages. The complex-induced cell apoptosis and blocked cell autophagy flux compared with both individually. The mechanism of toxicity may be by intracellular reactive oxygen species generation, impairing the mitochondrial membrane potential and activating apoptosis signaling pathways.     

相变溶剂捕集CO2技术的研究进展

化学溶剂吸收法是目前应用最广泛的燃烧后CO₂捕集技术。介绍了化学溶剂吸收法的基本原理,综述了化学溶剂吸收法的研究现状,比较分析了几种常用CO₂吸收剂的优缺点。重点阐述了两类新型相变吸收剂（液-液相变溶剂和液-固相变溶剂）的研究进展。指出：新型相变溶剂是理想的CO₂吸收剂,用其捕集CO₂可有效降低吸收剂的再生能耗;相变溶剂吸收CO₂的传质反应动力学以及不同类型相变溶剂的挥发和降解特性应作为今后该领域的研究重点。     

Epigenetic effects of N-methyl-N′-nitro-N-nitrosoguanidine on Kazakh esophageal epithelial cells

Epigenetic change is a key factor for esophageal cancer progression. This study shows that upon exposure of primary cultures of human esophageal epithelial cells obtained from people of the Kazakh nationality in China to N-methyl-N′-nitro-N-nitrosoguanidine at concentrations of 0.75, 1.50, and 3.00 mg/L, (1) cell proliferation was inhibited, the percentages of cells in the G₀ and G₁ phases declined, and those in the S and G₂ + M phases increased at all concentrations, while apoptosis rates increased at medium and high concentrations; (2) the content of DNA-methyltransferases 3a and 3b and the activities of DNA-methyltransferase 1 and DNA-methyltransferase 3a increased at all concentrations while the content of DNA-methyltransferase 1 and the activity of DNA-methyltransferase 3b were increased only at the high concentration; (3) messenger RNA and protein levels of DNA-methyltransferases 1, 3a, and 3b were increased at all concentrations. Obviously, N-methyl-N′-nitro-N-nitrosoguanidine in the low mg/L range can inhibit the proliferation of normal Kazakh esophageal epithelial cells, can cause cell cycle arrest in the S and G₂ + M phases, promote apoptosis, and increase the activities of DNA-methyltransferases 1, 3a, and 3b.     

稻壳基活性炭的制备及其对亚甲基蓝吸附的研究

以稻壳为原料,采用K2CO3活化法和H3P04活化法制备了比表面积为1312m^2／g和682m^2／g的活性炭,通过扫描电子显微镜（SEM）、X-射线衍射仪（XRD）对样品进行了表征,并将孔隙发达的活性炭样品用于对亚甲基蓝的吸附,结果表明,K2CO3活化法制备的活性炭样品具有更多的微孔结构;随着亚甲基蓝溶液初始浓度的增加、活性炭吸附时间的延长,亚甲基蓝的去除率呈现逐渐降低和逐渐增大的变化规律,当pH值为6时,活性炭对亚甲基蓝的吸附效果最佳;稻壳基活性炭对亚甲基蓝的吸附等温线符合Langmuir模型,Qm最高可达476．2mg／g;热力学参数△G^0△H^0和△S^0均为负值,表明稻壳基活性炭对亚甲基蓝的吸附是一个自发的放热反应。     

黄河上游地区（陕甘宁青）“三生空间”功能的演变特征及耦合协调分析

生产-生活-生态功能协调发展是可持续发展研究的热点问题。通过构建“生产-生活-生态”评价指标体系，运用三角模型、耦合协调度模型分析黄河上游地区三生功能状态、趋势以及耦合协调性的演变规律。结果表明：在1998—2017年黄河上游地区三生功能均显著上升，其中生产、生活功能的增长速率略高于生态功能；其相互作用随着时间从极低水平缓慢发展，先后经历了低水平和中等水平，最终发展到高等水平；耦合协调水平由低水平向中等水平波浪式发展，其中陕西省耦合协调水平相对较高，但距离高度协调还存在一定差距。在黄河上游地区可持续发展问题中，应根据三生功能耦合特征及影响因素，制定差异化策略，从而解决生产、生态功能之间的矛盾。