林丹通过MAPK和UPR通路与干扰线粒体功能诱导黑腹果蝇(Drosophila melanogaster)肿瘤细胞迁移

环境污染物增加癌症死亡率的潜在机理研究尚需开展。选择与癌症致死显著相关的林丹作为目标物质,将黑腹果蝇作为受试生物进行暴露,对1 000μg·L~(-1)和对照组的果蝇样本进行实时聚合酶链式反应(RT-PCR),检测发现参与调控癌症细胞迁移的丝裂原活化蛋白激酶(MAPK)信号通路中的MEKK和p38α、未折叠蛋白反应(UPR)中的ATF4、Ire1、PERK和XBP1等基因的表达量呈现显著下调(P0.05)。通过肿瘤迁移品系果蝇统计林丹暴露下肿瘤细胞迁移率,结果显示肿瘤细胞迁移率随林丹浓度升高而增加,1 000μg·L~(-1)林丹暴露组与对照组的果蝇肿瘤细胞迁移率分别为69.2%和45.9%,具有显著性差异(P0.05)。进一步的RNA测序结果表明,高浓度暴露组与对照组之间存在380个基因具有显著性差异(P0.05),其中含169个上调基因和211个下调基因。差异基因主要涉及水解酶催化活性(42个基因)、神经系统(20)、对化学刺激的感知(6)和线粒体(5)。差异基因的富集分析表明林丹的暴露主要改变蛋白水解过程(83个基因)、胞外区域(84)和催化活性(311),其对应的平均富集因子分别为1.59、1.52和1.24(P0.001)。差异基因的表达解释了林丹的暴露不仅致使线粒体功能障碍,而且影响蛋白水解酶活性,加速胞外基质降解,为肿瘤细胞迁移供能并提供微环境。     

苯胺对小鼠成纤维细胞L929的体外毒性评价

探讨不同浓度的苯胺化合物对小鼠成纤维细胞L929的体外毒性作用,为满足危险化学品分类鉴定和风险评估需求、更好地预防环境化合物对人体健康的损害提供理论依据。体外培养L929细胞,分别将不同浓度的苯胺化合物(0、0.001、0.01、0.1、1、10μg·mL~(-1))加入培养基中处理细胞,在不同时间点分别取材,MTT检测细胞增殖率,AO/PI染色检测细胞存活率,Annexin V-PI染色后流式细胞仪检测细胞凋亡,相关检测试剂盒测定细胞内活性氧(ROS)的含量及总谷胱甘肽的含量。结果表明,高浓度(1、10μg·mL~(-1))的苯胺化合物对L929细胞的生长和增殖具有显著的抑制效应。即使浓度降低至0.1μg·mL~(-1),在处理48 h后,细胞的存活数量显著下降,说明其对细胞增殖具有浓度和时间的累积效应和依赖性。同时,对各组细胞采用流式细胞仪测定细胞凋亡,发现低浓度的苯胺对细胞凋亡影响并不明显,但高浓度的苯胺处理后,细胞凋亡和坏死数量显著增加。ROS含量和GSH含量检测结果显示,较低浓度的苯胺对细胞氧化应激反应并无显著影响,但浓度至0.1μg·mL~(-1)时,细胞较对照组出现明显的氧化应激反应,说明细胞已受损,再继续培养将会导致细胞死亡。上述研究结果提示,高浓度苯胺化合物可显著影响L929细胞存活率,且具有时间和浓度累积效应。其毒性机制可能与细胞内活性氧增加、谷胱甘肽耗竭有关。     

Microbial fuel cell with three-dimensional electrodes for domestic wastewater treatment and electricity generation北大核心CSCD

A single chamber microbial fuel cell (MFC) with three-dimensional electrodes packed bed carbon felts was developed to treat domestic wastewater while simultaneously generating electricity. The influence of batch and continuous operation mode on treatment effectiveness and electricity production of the MFC was investigated to provide a reference for the application of the MFC. The MFC with a total working volume of 1 440 mL was operated in the fed-batch mode for 5 d repeatedly three times, and then shifted to the continuous mode. During the testing of the continuous mode, wastewater was continuously pumped into the anode compartment at a flow rate of approximately 0.2 mL/min, resulting in a hydraulic retention time of 5 d. During the batch test, the MFC obtained 91.1% chemical oxygen demand (COD) and 98.2% NH4 +-N removal, which accorded with the first criteria specified in the discharge standard of pollutants for municipal wastewater treatment plants in China (GB18918-2002). A maximum power density of 27.88 mW/m3 was achieved at a 51 Ω external resistor. During the continuous test, the COD removal efficiencies ranged from 83.2% to 97.4%. The concentration of NH4 +-N gradually decreased within 5 d and was then maintained below 9.45 mg/L, thus an enhanced removal performance of NH4 +-N was acquired. However, a low removal efficiency of total nitrogen was observed owing to the accumulation of NO3 --N in the effluent since day 11. Additionally, the MFC continually generated electricity with a maximum power density of 582.5 mW/m3 and average output voltage of 0.087 7 V during the stable period in the continuous operation mode. Moreover, 16S rRNA gene high-throughput sequencing showed that Thauera sp., Saprospiraceae-UN sp., and OPB56-UN sp. were identified as dominant populations. The results suggested that the organic matter associated with power generation was constantly utilized by the microorganisms in the reactor, which caused an excellent electricity generation performance during the continuous test. Therefore, the continuous operation mode could improve the low output voltage phenomenon in the MFC. Thauera sp., as a type of nitrate-reducing bacteria, was enriched in the autotrophic denitrifying microbial communities; therefore, bio-enrichment with denitrifying bacteria such as Thauera sp. could decrease the concentration of NO3 --N in the effluent during the continuous operation mode, which is expected to be an innovation for improvement of wastewater treatment. © 2018 Science Press. All rights reserved.     

地面输油管道泄漏流散数值模拟

针对库区地面输油管道发生泄漏后油品流散行为的不确定性,建立了地面油品泄漏流散的三维CFD仿真模型,模拟了不同管道运行压力和不同泄漏孔径下油品在地面上的流散过程,得到了油品扩展速度关于泄漏流量的关系式和流散面积关于管道压力、泄漏孔径、流散时间的偏微分方程组。结果表明:流散面积随管道压力增大呈线性函数增大;流散面积随泄漏孔径呈三次函数变化,先减小后增大;在泄漏的开始阶段,流散面积随泄漏时间的变化随管道压力呈线性增长,在扩展达到稳定时,扩展速度随泄漏流量呈指数函数增大。     

RUNOFF AND EROSION RESPONSE OF SIMULATED WASTE BURIAL COVERS IN A SEMI-ARID ENVIRONMENT1

ABSTRACT: Control of runoff (reducing infiltration) and erosion at shallow land burials is necessary in order to assure environmentally safe disposal of low-level radioactive-waste and other waste products. This study evaluated the runoff and erosion response of two perennial grass species on simulated waste burial covers at Idaho National Engineering and Environmental Laboratory (INEEL). Rainfall simulations were applied to three plots covered by crested wheatgrass [Agropyron desertorum(Fischer ex Link) Shultes], three plots covered by streambank wheatgrass [Elymus lanceolatus(Scribner and Smith) Gould spp. lanceolaus], and one bare plot. Average total runoff for rainfall simulations in 1987, 1989, and 1990 was 42 percent greater on streambank wheatgrass plots than on crested wheatgrass plots. Average total soil loss for rainfall simulations in 1987 and 1990 was 105 percent greater on streambank wheatgrass plots than on crested wheatgrass plots. Total runoff and soil loss from natural rainfall and snowmelt events during 1987 were 25 and 105 percent greater, respectively, on streambank wheatgrass plots than on crested wheatgrass plots. Thus, crested wheatgrass appears to be better suited in revegetation of waste burial covers at INEEL than streambank wheatgrass due to its much lower erosion rate and only slightly higher infiltration rate (lower runoff rate).     

甘薯细胞悬浮培养的建立及其生长研究

由甘薯叶片诱导出愈伤组织,并由此建立起悬浮培养细胞系．分析其生长表明：南薯８８和８１２９４两种细胞系生长曲线均呈“Ｓ”型,其中南薯８８生长较快,是８１２９４的３倍以上,１０ｄ培养物的鲜重是初始鲜重的１０倍．培养条件研究结果表明：南薯８８细胞悬浮培养的最佳２,４Ｄ质量浓度为１．０ｍｇＬ－１,最佳蔗糖质量浓度为３０ｇＬ－１,椰乳和酵母汁能明显促进其生长;对于８１２９４,２,４Ｄ最佳质量浓度为２．５ｍｇＬ－１、蔗糖最佳质量浓度１５ｇＬ－１,酵母汁可促进其生长,但椰乳却无效;谷氨酰胺、色氨酸和脯氨酸不能促进甘薯悬浮细胞的生长,水解酪蛋白对其生长的促进作用亦不大;葡萄糖则抑制其生长     

生物强化技术处理2,6-二叔丁基酚的研究

利用从腈纶废水处理厂中分离出来的一株2,6二叔丁基酚高效降解菌F34菌株,进行生物强化处理技术研究。通过对照环境中的2,6二叔丁基酚降解效果的比较分析,发现包埋后的F34菌株降解底物的能力相比游离的略有提高;F34菌株在活性污泥存在时受到其抑制作用,通过包埋,菌株所受的抑制作用减弱;在含活性污泥的B.H.和实际废水的环境中,投加F34菌株包埋颗粒显著改善了原系统对底物的处理能力,其对底物的去除率分别提高了164%和71.4%。     

DNA damage of germ cell of rat induced by nitrotoluene chemicals

2,4-dinitrotoluene(2,4-DNT), 2,6-dinitrotoluene(2,6-DNT) and 4-nitrotoluene(4-NT) are typical pollutants in the Songhua River of Northeast China. Sertoli/germ call cocultures and single cell gel electrophoresis(SCGE) are applied to investigate whether they have genotoxicity on DNA damage of germ cell of Kunming male rat. The results showed that all three nitrotoluene compounds tested could induce DNA single-strand breaks of the germ call. A significant relationship is found between logarithm dose and the degree of DNA damage, which implies that 2,4-DNT, 2,6-DNT and 4-NT have genotoxicity and can induce the germ cell DNA strand to break in vitro.     

酵母菌在废水处理中的应用

酵母菌既具有细菌单细胞、生长快、能形成很好的絮体、适应于各种不同的反应器等特点,又具有真菌细胞大、代谢旺盛,耐酸、耐高渗透压、耐高浓度的有机底物等特性,因而可用于多类难处理有机废水的处理,并且具有处理效率高、污泥负荷高、占地面积小、剩余污泥可回收用作饲料蛋白等特殊的优越性。酵母菌废水处理技术有望成为常规好氧和厌氧处理技术的重要补充而在工业废水治理中发挥重要作用。     

硫化氢制氢电解槽设计的改进及实验研究

硫化氢间接电解制氢过程中,在电解槽内采用湍流网结构可以有效地改善传质,基本消除扩散传质的影响。当槽压为1．1V,阴阳极流速皆为200L／h,电解温度为40℃的情况下,电解槽可以长时间保持良好性能,电流密度约为160mA／cm^2。