ABA对米槠和格氏栲种子发育的影响

采用酶联免疫分析法（ＥＬＩＳＡ） 提取和测定米槠和格氏栲发育过程中果实内ＡＢＡ含量,并用不同浓度ＡＢＡ喂养,测定果实不同发育期对外源ＡＢＡ的敏感性．用放射性同位素法测定ＡＢＡ对贮藏蛋白质的积累作用,结果表明：在米槠和格氏栲种子发育过程中内源ＡＢＡ 含量逐渐上升,两者均在１０ 月５ 日达到峰值,米槠为１６４８ ｎｇｇ,格氏栲为１ ４６８ ｎｇｇ,随后ＡＢＡ含量均逐渐下降．果实成熟采收时,ｃ（ＡＢＡ） 仅为高峰时的１９．随着果实的发育对外加ＡＢＡ的敏感性逐渐变小,ｃ（ＡＢＡ）＝１０－４ ｍｏｌＬ－１ 可以完全抑制１０ 月２５ 日（ 米槠） 和１０ 月１５ 日（ 格氏栲） 前种子发芽,但对完全成熟的种子ｃ（ＡＢＡ）＝１０－２ ｍｏｌＬ－１ 亦不能抑制发芽．ＡＢＡ 对成熟前期胚的贮藏蛋白质合成无影响,但能促进成熟中后期胚的贮藏蛋白质的积累作用,ＡＢＡ维持米槠和格氏栲贮藏蛋白质合成和积累作用表现在转录水平上．     

A numerical model for transient-hysteretic flow and solute transport in unsaturated porous media

A two-dimensional flow and transport model was developed for simulating transient water flow and nonreactive solute transport in heterogeneous, unsaturated porous media containing air and water. The model is composed of a unique combination of robust and accurate numerical algorithms for solving the Richards', Darcy flux, and advection-dispersion equations. The mixed form of Richards' equation is solved using a finite-element formulation and a modified Picard iteration scheme. Mass lumping is employed to improve solution convergence and stability behavior. The flow algorithm accounts for hysteresis in the pressure head-water content relationship. Darcy fluxes are approximated with a Galerkin and Petrov-Galerkin finite-element method developed for random heterogeneous porous media. The transport equation is solved using an Eulerian-Lagrangian method. A multi-step, fourth-order Runge-Kutta, reverse particle tracking technique and a quadratic-linear interpolation scheme are shown to be superior for determining the advective concentration. A Galerkin finite-element method is used for approximating the dispersive flux. The unsaturated flow and transport model was applied to a variety of rigorous problems and was found to produce accurate, mass-conserving solutions when compared to analytical solutions and published numerical results.     

绿色荧光蛋白标记阿特拉津降解基因工程菌的特性

通过转化绿色荧光蛋白基因质粒,对阿特拉津降解基因工程菌进行标记.转化后,绿色荧光蛋白在细胞内表达情况良好.在含抗生素的LB培养基中,绿色荧光蛋白的表达水平高于LB培养基和基础培养基.在细胞生长的稳定期,绿色荧光蛋白表达水平高于停滞期和对数生长期.绿色荧光蛋白基因质粒转化和表达,不会对基因工程菌原有的降解能力产生影响,而且绿色荧光蛋白的表达水平和降解活性存在接近线形的正相关关系.荧光蛋白标记细胞投加到反应器活性污泥中,会以2种状态存在:游离态和附着态,而且初期游离态细胞的数量大于附着态细胞的数量.     

二氧化硫衍生物对小鼠心、肝、肺蛋白质的氧化损伤作用

研究了二氧化硫(SO2)衍生物--亚硫酸钠和亚硫酸氢钠混合物(分子比为3:1),对小鼠心、肝、肺中蛋白质的氧化损伤作用,探讨其分子作用机制.连续5 d对动物腹腔注射SO2衍生物,每天注射剂量为0、0.025、0.100、0.400 g·kg-1.用2,4-二硝基苯肼比色法测定不同器官组织中蛋白质羰基含量.结果表明,SO2衍生物染毒剂量为0.025、0.100 和0.400 g·kg-1时,小鼠心、肝、肺蛋白质羰基含量染毒组与对照组相比均呈现不同程度的增加,不同器官羰基含量增量大小的次序为:肝＞肺＞心;其染毒剂量与心、肝、肺蛋白质羰基含量之间存在明显的剂量效应关系(p＜0.05),线性拟合确定系数分别为0.894、0.893和0.903.由此认为,SO2衍生物可引起小鼠心、肝、肺组织蛋白质的氧化损伤,以及不同组织器官的蛋白质氧化损伤程度不同.     

大有开发价值的蛋白质新资源——植物叶蛋白

随着世界人口的剧增和人民生活水平的提高,对优质蛋白质的需求越来越大,开发新的蛋白资源势在必行。作者从原料,营养价值,食用效果及经济效益四方面论述了植物叶蛋白的开发价值。     

五氯酚对斜生栅藻的毒性效应研究

以斜生栅藻细胞的生长状况、色素(叶绿素a、叶绿素b、类胡萝卜素)及蛋白质含量的变化作为指标,研究了不同质量浓度的五氯酚(0,0.02,0.05,0.10,0.50,1.00 mg/L)对斜生栅藻(Scenedesmus obliquus)的毒性效应.24,48,72,96和120 h五氯酚对斜生栅藻的EC50分别为0.883,0.283,0.225,0.168和0.192 mg/L.斜生栅藻生长受抑制程度随五氯酚质量浓度增加而加强,当五氯酚的质量浓度超过0.50 mg/L时,斜生栅藻的生长几乎完全受到抑制.染毒96 h的斜生栅藻色素(叶绿素a、叶绿素b、类胡萝卜素)含量以及蛋白质含量随着五氯酚质量浓度的增加呈下降趋势,色素比例失调,色素对五氯酚的敏感程度为:类胡萝卜素＞叶绿素a＞叶绿素b;可溶性蛋白质含量与色素含量的减少呈明显线性相关(r=0.793,n=6).      

赤泥对电解锰渣中可溶性锰离子固化效果研究

为了探讨赤泥固化电解锰渣中可溶性锰离子的固化效果和可行性,本文采用X射线衍射(XRD)、电子扫描显微镜(SEM)和X射线荧光光谱(XRF)等分析手段,对比评估了新鲜赤泥、陈旧赤泥(堆放1年以上)、生石灰以及陈旧赤泥复合生石灰等固化剂在不同添加剂量下对电解锰渣中可溶性锰离子的固化效果,并初步阐释了赤泥固化电解锰渣中可溶性...     

Phylogenetic Comparative Methods Strengthen Evidence for Reduced Genetic Diversity among Endangered Tetrapods

Abstract: The fitness of species with little genetic diversity is expected to be affected by inbreeding and an inability to respond to environmental change. Conservation theory suggests that endangered species will generally demonstrate lower genetic diversity than taxa that are not threatened. This hypothesis has been challenged because the time frame of anthropogenic extinction may be too fast to expect genetic factors to significantly contribute. I conducted a meta‐analysis to examine how genetic diversity in 894 tetrapods correlates with extinction threat level. Because species are not evolutionarily independent, I used a phylogenetic regression framework to address this issue. Mean genetic diversity of tetrapods, as assessed by protein heterozygosity, was 29.7–31.5% lower on average in threatened species than in their nonthreatened relatives, a highly significant reduction. Within amphibians as diversity decreased extinction risk increased in phylogenetic models, but not in nonphylogenetic regressions. The effects of threatened status on diversity also remained significant after accounting for body size in mammals. These results support the hypothesis that genetic effects on population fitness are important in the extinction process.     

Chemical characteristics and source apportionment of PM2.5 between heavily polluted days and other days in Zhengzhou, China

PM_(2.5) samples were collected in Zhengzhou during 3 years of observation, and chemical characteristics and source contribution were analyzed. Approximately 96% of the daily PM_(2.5) concentrations and annual average values exceeded the Chinese National Ambient Air Quality Daily and Annual Standards, indicating serious PM_(2.5) pollution. The average concentration of water-soluble inorganic ions was 2.4 times higher in heavily polluted days(daily PM32.5 concentrations 250 μg/mand visibility 3 km) than that in other days, with sulfate, nitrate, and ammonium as major ions. According to the ratio of NO-3/SO2-4,stationary sources are still the dominant source of PM_(2.5) and vehicle emission could not be ignored. The ratio of secondary organic carbon to organic carbon indicated that photochemical reactivity in heavily polluted days was more intense than in other days.Crustal elements were the most abundant elements, accounting for more than 60% of 23 elements. Chemical Mass Balance results indicated that the contributions of major sources(i.e., nitrate, sulfate, biomass, carbon and refractory material, coal combustion, soil dust,vehicle, and industry) of PM_(2.5) were 13%, 16%, 12%, 2%, 14%, 8%, 7%, and 8% in heavily polluted days and 20%, 18%, 9%, 2%, 27%, 14%, 15%, and 9% in other days, respectively.Extensive combustion activities were the main sources of polycyclic aromatic hydrocarbons during the episode(Jan 1-9, 2015) and the total benzo[a]pyrene equivalency concentrations in heavily polluted days present significant health threat. Because of the effect of regional transport, the pollution level of PM_(2.5) in the study area was aggravated.     

Studies on relationships between air pollutants and allergenicity of Humulus Scandens pollen collected from different areas of Shanghai

Pollen pollution and allergy are becoming prominent issues in China. However, few studies on pollinosis have been reported. As an allergen in the atmosphere, allergenic Humulus scandens pollen was collected from four districts of Shanghai, including Wusong (WS), Jiading (JD), Xujiahui (XJH) and Songjiang (SJ). The mass concentrations of SO₂, NO₂, O₃, PM_10, and PM_2.5 (particulate matter with air dynamic diameter less than 10 and 2.5 µm, respectively) near the four sampling sites were also recorded during Humulus scandens pollen season. The allergenicity of the Humulus scandens pollen was assessed by using of a rat model and enzyme linked immunosorbent assay (ELISA). Relationships between the allergenicity and air pollutants were correlated. Our results demonstrated that the biological viability of the pollens collected from the four districts exhibited no significant differences. ELISA and dot blotting results further demonstrated that the serum of sensitized rats exhibited much higher immune-reactive response than that of control groups. Western blotting showed that the 15 KD (1KD = 1000 dalton) proteins of Humulus pollen led to the allergic response. The allergenic intensity of Humulus pollen protein from different samples followed the pattern: WS > JD > XJ > SJ. There was a negative relationship between the allergenicity of Humulus pollens and PM₁₀ (R = -0.99) / PM_2.5 (R = -0.73), and a positive relationship with O₃ (R = 0.92). These data clearly showed that PM₁₀ and PM_2.5 could enhance Humulus pollen protein release, and O₃ could aggravate the allergenicity of the Humulus pollen.