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The health menace of tobacco   总被引:2,自引:0,他引:2  
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Environmental tobacco smoke and other pollutants present in both smoking and nonsmoking cabin sections during commercial passenger flights on DC-10 aircraft were determined on four, 5-h smoking flights. The average concentrations of nicotine, 3-ethenylpyridine, CO2, CO, NOx, NO2, O3, PM2.5 and environmental tobacco smoke particles during a flight were determined with a briefcase sampling system. Concentrations of nicotine, 3-ethenylpyridine and CO as well as temperature, humidity and pressure were determined as a function of time during the flight. A model to predict penetration of environmental tobacco smoke from the smoking to the nonsmoking section of the passenger cabin under a variety of flight conditions is derived from the data.  相似文献   

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Effects of auxin as plant hormones are widespread; in fact in almost all aspects of plant growth and development auxin plays a pivotal role. Although auxin is required for propagating cell division in plant cells, its effect upon cell division is least understood. If auxin is depleted from the culture medium, cultured cells cease to divide. It has been demonstrated in this context that the addition of auxin to auxin-starved nondividing tobacco BY-2 cells induced semisynchronous cell division. On the other hand, there are some cell lines, named habituated cells, that can grow without auxin. The cause and reason for the habituated cells have not been clarified. A habituated cell line named 2B-13 is derived from the tobacco BY-2 cell line, which has been most intensively studied among plant cell lines. When we tried to find the difference between two cell lines of BY-2 and 2B-13 cells, we found that the addition of culture filtrated from the auxin-habituated 2B-13 cells induced semisynchronous cell division in auxin-starved BY-2 cells. The cell division factor (CDF) that is responsible for inducing cell division in auxin-starved BY-2 cells was purified to near-homogeneity by sequential passage through a hydroxyapatite column, a ConA Sepharose column and a Sephadex gel filtration column. The resulting purified fraction appeared as a single band of high molecular weight on sodium dodecyl sulfate-polyacrylamide gel electrophoresis gels by silver staining and was able to induce cell division in auxin-starved BY-2 cells. Identification of the protein by MALD-TOF-MS/MS revealed that it is structurally related to P-glycoprotein from Gossypioides kirkii, which belongs to ATP-binding cassette (ABC)-transporters. The significance of CDF as a possible ABC-transporter is discussed in relationship to auxin–autotrophic growth and auxin-signaling pathway.  相似文献   

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几种农药在烟草上的消解动态与复合效应   总被引:9,自引:0,他引:9  
采用室外盆栽试验方法,研究了吡虫啉、高效氯氰菊酯在烟草上的消解动态,同时研究了多菌灵、高效氯氰菊酯对吡虫啉及吡虫啉对高效氯氰菊酯降解速度的影响.结果表明,吡虫啉在烟叶中的消解半衰期为3.98d,喷药后15d,降解了94.60%;高效氯氰菊酯对吡虫啉降解表现出延缓作用,而多菌灵对吡虫啉降解表现出加速作用.高效氯氰菊酯在烟草中消解半衰期为4.82d,喷药后15d,消解了88.32%;吡虫啉对高效氯氰菊酯的消解表现出延缓作用.  相似文献   

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Despite decades of messages warning about the dangers of tobacco use in pregnancy, 10% to 15% of pregnant women continue to smoke. Furthermore, an increased popularity of electronic nicotine delivery systems (ENDS) over the past decade in women of childbearing age raises parallel concerns regarding the effects of vaporized nicotine use in pregnancy. While research using animal models which mimic tobacco smoke and nicotine exposure in pregnancy have largely replicated findings in humans, few studies focus directly on the effects of these exposures on the placenta. Because the placenta is a fetal derived tissue, and nicotine and other components of tobacco smoke are either processed by or transported directly through the placenta, such studies help us understand the risks of these exposures on the developing fetus. In this review, we summarize research on the placenta and placental-derived cells examining either tobacco smoke or nicotine exposure, including both histologic and subcellular (ie, epigenetic and molecular) modifications. Collectively, these studies reveal that tobacco and nicotine exposure are accompanied by some common and several unique molecular and epigenomic placental modifications. Consideration of the nature and sequelae of these molecular mediators of risk may help to better inform the public and more effectively curtail modifiable behavior.  相似文献   

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烟草制品加工过程中会产生大量的废水,且含有尼古丁等多种复杂的有毒难降解污染物,如不合理处置,将对环境造成严重的污染并危害人类健康,因而有效处理该类废水是烟草行业中一个亟待解决的技术难题.利用梯度筛选驯化法从环境中获得3组高效处理烟草加工废水的菌群,其中高效菌群C对化学需氧量(COD)的去除率达83.1%,且其他各项指标如色度、氨氮(NH_4~+-N)及磷酸盐(PO_4~(3-)-P)等均明显降低.微生物群落结构分析结果显示,菌群的香农-威纳指数(Shannon-Wiener Index)、辛普森多样性指数(Simpson Index)和菌群丰富度指数(ACE)分别为3.645、0.978、106,表明菌群多样性高,物种构成复杂,分布均匀.菌群C中变形菌门占有最大比例为48.7%,其次为放线菌门,比例为11.5%,并在菌群中检测出多种具有降解杂环芳香化合物、芳烃及酚类等物质的菌种.污染物检测结果证明,菌群处理后污染物整体去除率近90%,其中尼古丁被完全降解,去除率为100%.本研究获得的菌群不仅可以针对性的降解主要污染物尼古丁,且能够全面去除其他污染物,在烟草废水处理领域具有广阔的应用前景.  相似文献   

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本研究选用不同热解温度(300,500和700℃)制备的烟梗生物炭,与有机污染物对硝基苯酚(PNP)进行吸附降解反应,探究反应前后烟梗生物炭上持久性自由基(EPFRs)信号强度与其降解有机污染物活性的关系.结果显示:生物炭中EPFRs信号强度随热解温度的升高而从6.155×104升高至1.343×105后降低至5.458×104,而PNP的液相降解率则表现为随热解温度的升高先保持为31%左右不变后下降至14.64%,表明生物炭的EPFRs信号强度与活性并不成正比.300℃热解制备的生物炭中以氧为中心的自由基可以将电子转移给水中的氧分子生成活性氧并促进PNP的降解.而500与700℃热解制备的生物炭中碳为中心的自由基与污染物进行降解反应后生成了新的自由基并被稳定于生物炭表面,导致其自由基信号增强降解活性却大幅下降.  相似文献   

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对间歇及连续运行废水活性污泥处理过程去除人为污染高浓度烟草花叶病毒(tobaccomosaicvirus,TMV)的效率及其影响因素进行了研究.结果显示活性污泥去除TMV的效果受工艺参数的影响,其中污泥浓度直接影响所加入TMV的去除效率.同时,曝气强度也影响病毒的去除效率.在2个具不同运行工艺参数的活性污泥系统中连续加入枯斑数达(2 5~6 7)×104·L-1的TMV,连续运行一周其去除率仍均大于98%.当污泥BOD负荷率在0 534~0 899kg·(kg·d)-1,水力停留时间在4 8~10 2h,平均MLVSS在1780~3250mg·L-1范围内,TMV的去除效率同这些参数关系不大,说明活性污泥系统可有效地去除植物病毒而不过分地依赖于工艺条件,这为活性污泥法去除植物病毒的稳定性提供了保证.然而病毒的去除不等于灭活,很大程度上病毒仅是从液相转移到了固相,污泥中的病毒浓度往往比游离高出许多倍.因此在污泥农用、处置时要充分考虑到污泥的病毒学安全性问题.同时,在评价废水处理的有效性时也要考虑到这种现象.  相似文献   

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以剩余污泥和烟草废弃物为研究对象,探究了针铁矿对有机物厌氧消化产甲烷的影响.针铁矿投加能提高消化产气率至359.4mL/g,显著高于空白对照组.针铁矿有助于混合气体中甲烷含量的升高并减少CO2的体积分数.针铁矿利于剩余污泥和烟草废弃物共消化过程有机物溶出,纤维素减量,从而为产甲烷古菌提供充足的消化底物.针铁矿利于酸化代谢过程,在针铁矿投加组中挥发性脂肪酸的最大产量仅为56.2mg/g,显著低于空白组,此外针铁矿促进丙酸的合成.针铁矿促进乙酸降解,在消化第1d,针铁矿投加实验组中乙酸降解率高达65.5%,较高于空白组中的56.6%.酶活性分析表明针铁矿促进水解,酸化及产甲烷过程关键酶.Methanothrix和Methanobacterium是产甲烷阶段重要微生物,454高通量测序表明针铁矿提高Methanothrix和Methanobacterium的相对丰度至59.6%和23.5%,显著高于空白对照组.  相似文献   

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