细胞色素P450酶系及其在毒理学上的应用

综述了细胞色素P450酶系在生物有机体中催化代谢外来化合物的 影响因素。作为生物体内的混合功能氧化酶系统的重要组成部分。P ytP450酶系（Cytochrome P450）在毒理学上的意义是作为早期预警系统来监测和预报环境污染状况的。在实际应用中，常以动物（多以鱼作为实验材料）肝脏中P450酶系的诱导作为评价多环芳烃、多氯联苯、二恶英、石油烃类环境污染状况的最灵敏的生物学反应之一。对P450作为生化指标的优点和局限性也进行了探讨。     

施加磷元素后对小麦抗重金属铜毒性的影响

将小麦幼苗放在含有不同浓度磷元素(1 mmol/L和10 mmol/L)和铜元素(0.16μmol/L、100μmol/L和1 mmol/L)的培养液中处理12 h后,观察植物体内铜元素的含量、叶绿素含量、抗坏血酸循环的变化.结果表明,当培养液中施加的铜元素浓度相同时,施加较高浓度的磷(10 mmol/L)能促进植物根部吸收和积累铜,并能促进铜元素从根部向地上部的运输.此外,实验结果还表明,当培养液中都含有较少量的铜(0.16μmol/L)元素时,比较磷浓度对植物体内生理反应的影响时,发现在含有高浓度磷的培养液中培养的小麦体内的受到较少的膜质过氧化损伤,光合色素的含量保持稳定.但是,当培养液中有较高浓度的铜元素(100μmol/L和1 mmol/L)时,施加高浓度的磷反而加剧了植物体内的膜质过氧化损伤和引起光合色素的分解,从而不利于植物正常的生长发育.     

水稻耐低磷特性研究

选取3个耐低磷水稻基因型99011、580、99112和1个磷敏感基因型99056为供试材料，采用营养液和石英砂培养的方法，研究了与磷效率相关的一些指标．结果表明，99011和580均具有较高的磷吸收效率和利用效率，其中根长是99011高效吸收的重要贡献因子，其次它对难溶性磷有一定的活化吸收能力；580不仅对难溶性磷的活化吸收能力最强，而且善于从低浓度的磷环境中吸收较多的磷；而99112主要靠被动适应生态环境来表现它的耐低磷特性，与磷吸收效率相关的次级因子表现不佳，是99056对低磷反应敏感的主要原因．图3表4参16     

四川盆地果梅生产的气候生态适宜性研究

根据果梅对环境条件的要求，通过对其分布地区的气侯特征和生态表现的调查分析，本文提出以年均温和１月均温为果梅生态适宜性划分的依据．根据四川盆地的气候特点．提出了果梅栽培的最适区、适宜区和次适宜区．本文对四川盆地发展果海生产．提高经济效益，改善生态环境具有一定的指导意义．     

Provisional drivers' perceptions of the impact of displaying P plates

Objective: P plates (or decals) identify a driver's license status to other road users. They are a compulsory part of the graduated driver licensing system in Queensland, Australia, for drivers on a P1 (provisional 1) or P2 (provisional 2) license. This study explored the perceptions of young drivers regarding the display of P plates (decals) in Queensland, Australia.

Methods: In this study, 226 young drivers with a provisional (intermediate/restricted) license completed a 30-min online survey between October 2013 and June 2014. t Tests were used to compare the opinions of people who displayed their plates nearly always with those who displayed them less frequently.

Results: Participants approved of the requirement to display P plates with 69% of those on a P1 license and 79% on a P2 license supporting the condition to display P1 (red) plates. Participants on a P1 license (62%) and a P2 license (68%) also approved the requirement to display P2 (green) plates. However, young drivers also perceived that the display of P plates (measured from 1 = never to 5 = nearly all the time) enabled newly licensed drivers to be targeted by police and other drivers (those who do not always display P plates: M = 3.72, SD = 0.94; those who nearly always display P plates: M = 3.43, SD = 1.09).

Conclusions: The study findings suggest that participants who nearly always display their P plates are more likely to report that having to display their plates resulted in them driving more carefully.     

Furanocoumarins and their detoxification in a tri-trophic interaction

The parsnip webworm, Depressaria pastinacella, specializes on wild parsnip, Pastinaca sativa, and several species of Heracleum, hostplants rich in toxic furanocoumarins. Rates of furanocoumarin metabolism in this species are among the highest known for any insect. Within its native range in Europe, webworms are heavily parasitized by the polyembryonic parasitoid wasp Copidosoma sosares. In this study, we determined whether these parasitoids are exposed to furanocoumarins in host hemolymph, whether they can metabolize furanocoumarins, and whether parasitism influences the ability of webworms to detoxify furanocoumarins. Hemolymph of webworms fed artificial diet containing 0.3 % fresh weight xanthotoxin, a furanocoumarin prevalent in wild parsnip hosts, contained trace amounts of this toxin; as well, hemolymph of webworms consuming P. sativa flowers and fruits contained trace amounts of six of seven furanocoumarins present in the hostplant. Thus, parasitoids likely encounter furanocoumarins in host hemolymph. Assays of xanthotoxin metabolism in C. sosares failed to show any ability to metabolize this compound. Parasitized webworms, collected from populations of Heracleum sphondylium in the Netherlands in 2004, were on average 55 % larger by weight than unparasitized individuals. This weight is inclusive of host and parasitoid masses. Absolute rates of detoxification (nmoles min⁻¹) of five different furanocoumarins were indistinguishable between parasitized and unparasitized ultimate instars, suggesting that the intrinsic rates of metabolism are fixed. Thus, although parasitized larvae are larger, detoxification rates are not commensurate with size; rates in parasitized larvae expressed per gram of larval mass were 25 % lower than in unparasitized larvae.     

1998年临猗5.0级地震前Q值的前兆异常

利用西安数字地震遥测台网记录的数字地震资料,采用P波初动半周期残差法求得了1998年7月临猗5.0级地震前后不同路径的Q值变化.发现在地震发生前Q在87(203之间,震后Q在67～164之间,震前震中区附近出现了明显的高Q值异常,表明地震前的高Q值异常可以作为地震预测的一种手段.     

人工湿地污水处理系统冬季植物的筛选与评价

选用25种冬季湿地植物进行了污水净化潜力筛选试验,并在综合应用原有湿地植物筛选与评价体系的基础上,增加植物逆境酶和基质酶指标,对试验植物进行了聚类分析.结果表明,测试植物的根系长度、活力、叶片丙二醛含量、生长量、氮磷浓度、氮磷的积累能力、根际基质脲酶活性与磷酸酶活性均存在显著差异.采用建立的净化潜力评价体系将测试植物聚类分为3大类,第1类净化力强,植物种类有水芹、油菜、灯芯草、虎耳草、德国鸢尾、桂花和花菖蒲,第2类净化力中等,植物种类有羽衣甘蓝、金盏菊、撒金珊瑚、女贞、红甜菜、杜鹃和大叶冬青,第3类净化力弱,植物种类有白菜、五月菊、月季、金鱼草、麦冬、葱兰、熊掌木、矮牵牛、小叶冬青、香石竹和红继木.     

Influence of the time factor on the availability of deposits of nonferrous metals

This study presents a probabilistic approach to the assessment of mineral deposits availability. This approach takes into account the joint influence of decision making involving deposits in development and the difficulty in formalizing socio-economic factors. Using this approach, we designed a model for estimating the availability of deposits with regard to the influence of the length of time elapsed prior to beginning development; values for copper deposits in Russia, the USA and Canada were calculated. The characteristics of mineral resources are determined by an experimental method for these countries. These characteristics are defined by periods when the time factor has a positive influence on deposit availability.     

Distribution of benzo[a]pyrene in discrete regions of rat brain tissue using light microscopic autoradiography and gamma counting

In order to study the distribution of benzo[a]pyrene (B[a]P) in rat brain, Sprague-Dawley male rats, 21-day-old, weighted 40–50 g were given a single intravenous (iv) injection of 3.7 × 10⁵ Bq kg^?1 of ¹⁴C-B[a]P. Rats were sacrificed at 1, 6, 12, 24, or 48 h after the administration of radiolabeled B[a]P. Light microscopic autoradiography and gamma counting were used. Gamma counting and light microscopic autoradiography showed that ¹⁴C-B[a]P localized in hippocampus at 1 h, in cerebral cortex at 6 h, and corpus striatum at 24 h after treatment. After B[a]P administration, silver grains rose with time reaching a peak at 24 h and sharp decrease at 48 h. The silver grains distribution was higher in neurons than in gliocytes. Thus, B[a]P penetrated the blood-brain barrier and distributed in various regions of rat brain.