Sediment–water interactions of natural oestrogens under estuarine conditions

The natural human female hormones oestrone and 17β-oestradiol have been implicated in the disruption of endocrine systems in some wildlife adjacent to sewage effluents. The sorption behaviour of these two compounds under estuarine conditions was studied by spiking either 2.55 μg of oestrone or 2.65 μg of 17β-oestradiol in kinetic experiments. In equilibrium experiments, 3 ng of oestrone or 3.2 ng of 17β-oestradiol was added in each of the centrifuge tubes. Sorption onto sediment particles was relatively slow, with sorption equilibrium being reached in about 70 and 170 h for oestrone and 17β-oestradiol, respectively. The effects of a variety of environmental parameters on sorption were studied including salinity, sediment concentration (SC), the presence of a third phase, particle size and, also, surfactant concentrations. Results show that although salinity did not induce any statistically significant effect on the sorption of 17β-oestradiol, it did statistically enhance the sorption of oestrone, and a salting constant of 0.3 l mol⁻¹ was derived. The partition coefficient for both compounds decreased with increasing sediment concentration, a phenomenon that has been widely reported and attributed to the presence of colloids (which could enhance dissolved concentrations). In this paper, the true partition coefficients for sediment particles (K_p^true) and colloidal particles (K_c^true) have been calculated, and a K_p^true value of 141 and 102 ml g⁻¹ was obtained for oestrone and 17β-oestradiol, respectively. In addition, K_c^true values for oestrone (222×10² ml g⁻¹) and 17β-oestradiol (135×10² ml g⁻¹) were two orders of magnitude higher than their respective K_p^true values, suggesting that the colloidal particles are significantly stronger sorbents for natural oestrogens than sediment particles. Particles of different sizes were found to have different partition coefficients due to the strong relationships between partition coefficients for the two compounds and particulate organic carbon (POC) contents and specific surface areas (SSAs). The presence of a surfactant was shown to reduce the partition coefficients for the two compounds, although its concentrations being used were higher than those normally found in the natural environment.     

胃肠酸度下中药及补铁制剂中铁活性的影响研究

在人体胃肠液的酸度条件下,采用正辛醇-水分配体系模拟药物在人体肠胃中的分配情况,研究了中药和补铁制剂中铁的形态及其在人体内的吸收情况,并探讨了中药不同比例的配伍、胃肠酸度及还原性物质的存在对水溶态铁和醇溶态铁的影响。结果表明,药物溶液中的铁形态与药物本身特性和配伍情况有关,酸度及配伍对药物中铁的溶出率和溶液中铁的形态有较大影响,人体对铁的吸收与胃肠酸度和还原性物质的存在有关。     

碲的泡塑预分离M17树脂富集原子荧光测定法

采用王水溶样，泡沫塑料预分离金等干扰组分，以Ｍ１７树脂富集Ｔｅ并使之与大部分共存的干扰元素分离，建立了原子荧光含金地质样品中碲的方法，用地矿部标准参考样品和含金地质试样分析考察，结果满意。方法检测下限为０．００９×１０＾－６。     

大黄鱼白细胞介素17受体E-like的分子特征及进化分析

白细胞介素17受体(Interleukin 17 receptor,IL-17R)家族与IL-17细胞因子家族介导的各类反应有着密切联系.IL-17RE-like(IL-17REL)是一类最新发现的IL-17受体,其结构与IL-17RE相似,但尚未发现其配体.本研究克隆得到大黄鱼(Larimichthys crocea)IL-17REL(Lyc IL-17REL)的全长c DNA,其开放阅读框全长1 659个核苷酸,推断可编码一个由552个氨基酸组成的蛋白,含有信号肽、胞外段、跨膜区和胞内段.与其他物种的IL-17REL相似,Lyc IL-17REL蛋白的胞外段具有一个保守的FN I-like结构域,而胞内段缺少IL-17受体家族保守的SEFIR(SEF and IL-17R)结构域.多序列比对分析表明Lyc IL-17REL与日本河豚(Takifugu rubripes)IL-17REL的氨基酸序列同源性最高,序列一致性可达57.0%.系统进化分析表明,脊椎动物的IL-17受体家族可分为2类,IL-17RA/RB/RD为一类,IL-17RC/RE/REL为一类.其中鱼类及高等脊椎动物的IL-17REL与IL-17RE亲缘关系最近,并且推测二者可能是由同一基因从硬骨鱼类之前的物种中分化而来.组织分布表明Lyc IL-17REL在所有被检测的组织中为组成型表达,在黏膜相关组织如小肠和鳃中的表达量最高.大黄鱼受嗜水气单胞菌(Aeromonas hydrophila)诱导刺激后,Lyc IL-17REL在其头肾及鳃中的基因转录水平均显著上调.这表明Lyc IL-17REL可能在细菌感染引起的免疫反应中起着重要作用.     

M17树脂对岩石中痕量硒碲的分离富集研究及应用

M_(17)树脂在>6mol/L的HCl介质中能同时吸附Se和Te,Se和Te可用水和丙酮分别洗脱,也可用丙酮同时洗脱。从而建立了两个新的Se、Te分离富集体系,使原子荧光测定达到纳克量级。     

M17树脂分离富集原子荧光测定岩矿中痕量碲

本文研究了不同种类树脂对Te的吸附能力,提出了在3mol/L HCl介质中,用M_(17)二甲胺树脂吸附,然后用水洗脱的新途径,使Te有效且无污染地得到分离和富集,实现了原子荧光测定地质试样中ppb级痕量Te。经地矿部标准参考样GSR7-12考察,分析结果与推荐值相符。     

Preparation and After-Treatment of BaMgAl10 O17 ：Mn^2＋

INTRODUCTION The properties of phosphor usedin a plasma dis-play panel (PDP) affect the performance of the PDP(Okazaki et al .,2000 ; Rao and Devine ,2000) . Theluminescent properties of the phosphor are decided bythe morphology ,particle size and size distribution ofthe powder ,sothe requirements for the powder mor-phology are high in a color PDP which belongs to ahigh resolution display apparatus (I m et al .,2005 ;Yang et al ., 2005) . Studies have shown that withsmall particle si…     

双棘黄姑鱼血清性类固醇激素的周年变化

采用放射免疫法(RIA)测定双棘黄姑鱼(Nibea diacanthus)血清性类固醇激素的周年变化。结果表明:雌鱼血清雌二醇(Estadiol-17β)浓度一年出现两次峰值,均在成熟产卵前一个月,即4月[(338±59)pg/mL]和9月[(296±48)pg/mL];血清睾酮(T)浓度在卵黄发生期急剧上升,并在卵巢成熟期达到最高值,分别是5月(2.506±0.262 ng/mL)和10月份(2.268±0.243 ng/mL),分别在血清雌二醇浓度两次峰值出现1个月之后,因此,雌鱼的血清雌二醇浓度和血清睾酮浓度均与性腺发育相关。雄鱼血清睾酮浓度的两次峰值均出现在性腺已发育成熟的5月份(2.307±0.792 ng/mL)和10月份(2.286±0.607 ng/mL),与性腺发育有明显的相关性;而血清雌二醇浓度全年维持在一个相对稳定的水平,与雄性性腺发育相关性不明显。     

基于Clementine热红外数据的Apollo17登月点区域氧化钙含量反演

为了研究利用Clementine热红外数据反演月球表面岩石的氧化钙(Ca O)含量,论文选取了两景覆盖Apollo17登月点的Clementine热红外影像,将其覆盖的区域选为研究区。利用月球表面温度物理模型模拟月表温度,结合普朗克函数,完成发射率反演。在此基础上,对LPI中35个除Apollo17登月计划外所采集的样品Ca O含量与其热红外发射率特征做回归统计分析,发现存在很好的线性关系(R2=0.661)。由此,基于Clementine热红外发射率实现了研究区Ca O含量反演。通过利用LPI Apollo17月岩(壤)样品实际Ca O含量分析数据对反演结果进行精度评价,发现8组反演值与实际值的相对误差最小为1.77%,最大为9.29%,均方根误差为0.767。研究结果表明,使用发射率进行Ca O含量反演方法可行,为利用Clementine热红外数据对月表矿物成分含量定量反演提供一种新的思路。     

The material conditions for research in France from 1600 to 1850: Physics,chemistry and astronomy

The income of the scientists in France during the 17th to the middle of the 19th century is reviewed and compared to the cost of their instruments. Only a small number of scientists received enough public money to be able to do full-time research; this number increased substantially after the Revolution. Most scientists had to have other sources of income, in particular to be able to purchase their instruments. Large research projects, generally decided and financed by the Academy of Sciences, took place during this period, requiring collaborative interdisciplinary efforts and a considerable logistics: they anticipate our present cooperative programs and giant research facilities.