Essential (Mg,Fe, Zn and Cu) and Non-Essential (Cd and Pb) Elements in Predatory Insects (Vespa crabro and Vespa velutina): A Molecular Perspective

The recent introduction of the Asian yellow-legged hornet, Vespa velutina, into Europe has raised concern regarding the threat to honeybees and the competition with the European hornet, Vespa crabro. The aim of this study was to investigated essential (Mg, Fe, Zn, Cu) and non-essential (Cd and Pb) elements in these two species. Element concentrations were determined in the whole body and separately in the head, thorax and abdomen using atomic absorption spectrometry (AAS). The changes in essential element concentration and speciation during metamorphosis were also studied using size exclusion chromatography followed by AAS and proteomic analysis. In both species, the essential elements were more concentrated in the abdomen due to the presence of fat bodies. Magnesium, Fe and Zn concentrations were significantly higher in V. crabro than in V. velutina and could have been related to the higher aerobic energy demand of the former species required to sustain foraging flight. Low concentrations of Cd and Pb were indicative of low environmental exposure. The concentration and speciation of essential elements, particularly Fe, varied among the developmental stages, indicating a modification of ligand preferences during metamorphosis. Overall, the results in the present study provide a better understanding of the hornet metal metabolism and a foundation for additional studies.     

Temperature adaptability of the soluble lead flow battery using different solutions of fluoborate,perchlorate, methanesulfonate and trifluoromethanesulfonate

The evaluation of cell's weatherability is of practical interest. To further improve the soluble lead flow battery's weatherability, physiochemical properties of electrolytes containing fluoborate, perchlorate, methanesulfonate and trifluoromethanesulfonate are investigated from ?60 to 50 °C. Activities of CF₃SO₃H and HClO₄ are poor in trifluoromethanesulfonate and perchlorate solutions due to common anion effect. The solubility of lead salt can be improved by increasing temperature, but worsened by increasing acid's content. With the temperature increasing, the conductivity is enhanced, and the viscosity is lowered for four solutions. The same results have been found by increasing acid's content except for CF₃SO₃H. The high energy efficiency can be achieved for cells over ?40–0 °C using fluoborate and perchlorate solutions, 73.2% at ?40 °C and 78.1% at ?30 °C respectively. Over the temperature range of 20–50 °C, the cells with methanesulfonate and trifluoromethanesulfonate solutions have good performance, 77.4% and 73.7% at 50 °C respectively.     

烧结时间对含铅玻璃制备微晶玻璃析晶及性能的影响

以铅玻璃与粉煤灰为原料，通过协同熔炼制备了微晶玻璃。通过XRD和SEM等手段研究了不同烧结时间下微晶玻璃的物相组成及显微结构，测定了微晶玻璃的密度、吸水率、维氏硬度和化学抗性。结果表明: 延长烧结时间对含铅玻璃加入量为40%(FG40)、50%(FG50)样品的晶相类型和晶化程度有影响，而对含铅玻璃加入量为60%(FG60)、70%(FG70)和80%(FG80)样品的影响较小。随着烧结时间延长，样品晶化程度提高，晶体长大，玻璃相减少。适宜的含铅玻璃加入量为50%~70%，对应的FG50、FG60、FG70样品最佳烧结时间分别为4 h、3 h、3 h。     

Activity-Directed Synthesis: A Flexible Approach for Lead Generation

Activity-directed synthesis (ADS) is a structure-blind, functional-driven molecular discovery approach. In this Concept, four case studies highlight the general applicability of ADS and showcase its flexibility to support different medicinal chemistry strategies. ADS deliberately harnesses reactions with multiple possible outcomes, and allows many chemotypes to be evaluated in parallel. Resources are focused on bioactive molecules, which emerge in tandem with associated synthetic routes. Some of the future challenges for ADS are highlighted, including the realisation of an autonomous molecular discovery platform. The prospects for ADS to become a mainstream lead generation approach are discussed.     

郴州某复杂硫化铅锌矿阶段磨浮试验研究

针对郴州某复杂硫化铅锌矿资源的性质特点,采用铅快速浮选后尾矿再磨再选的阶磨阶选工艺,较好地实现了铅锌的高效浮选回收。研究了磨矿方式、捕收剂和调整剂种类及用量等因素对该矿石浮选的影响,确定了最佳浮选条件,通过小型闭路浮选试验,得到了铅品位60.05%、回收率89.63%的铅精矿和锌品位47.01%、回收率88.14%的锌精矿。     

氢化物原子荧光光谱法测定酱油中微量铅的方法研究

建立了一种快速、高效的QuEChERS-高效液相色谱-质谱联用法（QuEChERS-HPLC-MS/MS）测定谷类杂粮制品中脱氧雪腐镰刀菌烯醇（DON）、3-乙酰脱氧雪腐镰刀菌烯醇（3-ADON）、15-乙酰脱氧雪腐镰刀菌烯醇（15-ADON）和玉米赤霉烯酮（ZON）共4种真菌毒素。样品前处理采用乙腈-水溶剂提取，经Florisil+C18+无水硫酸镁净化后检测。以0.10%甲酸-乙腈作为流动相，在质谱检测器的多反应监测模式下进行分析。结果表明，4种真菌毒素在各自的线性范围内线性关系良好，相关系数R2均大于0.999，回收率在85.1%～102.0%，相对标准偏差（RSD）为2.11%～6.22%。该方法具有前处理简单、净化效果好、灵敏度高和检测速度快的优点，适用于谷类杂粮制品中DON、3-ADON、15-ADON 和ZON的分析和定量检测。     

Ca掺杂钨镁酸铅陶瓷材料的制备及其介电性能

研究了Ca掺杂钨镁酸铅(PMW)陶瓷材料的合成、结构、烧结以及介电性能。结果发现：在Ca^2 摩尔分数小于15％时，能形成单相的PCMW钙铁矿相，结构由原来的斜方相向立方相转变。用二步合成法制备的样品容易致密烧结，气孔率比一步法制备的样品小。Ca的加入降低了材料的介电损耗，在频率为1MHz时，介质损耗达到了10^-4。当Ca^2 摩尔分数大于10％时，材料的Curie峰宽化显著，介电常数温度系数降低。     

碱式苦味酸铅针刺药的应用研究

提出了以碱式苦味酸铅为主体的针刺药在组合点火管中的应用，并对其针刺药的点火性能及能量传递进行了讨论，阐明了此类针刺药良好性能和应用价值。     

Spare parts inventory management with demand lead times and rationing

We study an inventory system that consists of two demand classes. The orders in the first class need to be satisfied immediately, whereas the orders in the second class are to be filled in a given demand lead time. The two classes are also of different criticality. For this system, we propose a policy that rations the non-critical orders. Under a one-for-one replenishment policy with backordering and for Poisson demand arrivals for both classes, we first derive expressions for the service levels of both classes. The service level for the critical class is an approximation, whereas the service level for the non-critical class is exact. We then conduct a computational study to show that our approximation works reasonably, the benefits of rationing can be substantial, and the incorporation of demand lead time provides more value when the demand class with demand lead time is the critical class. The research is motivated by the spare parts service system of a major capital equipment manufacturer that faces two types of demand. For this company, the critical down orders need to be satisfied immediately, while the less critical maintenance orders can be satisfied after a fixed demand lead time. We conduct a case study with 64 representative parts and show that significant savings (as much as 14% on inventory on hand) are possible through incorporation of demand lead times and rationing.     

Variation de la plombemie en fonction de la contamination par le plomb de l'eau livree a la consommation: Variation of the blood lead level as a result of lead contamination of the subjects drinking water

The combination of the chemical aggressivity of water and lead piping, as is well known, can cause severe cases of lead poisoning in those who consume such water. After a great number of observations and epidemiological studies which have strongly incriminated this metal in a wide range of pathologic conditions, other materials have been gradually substituted for lead; however, the problem remains.In compliance with a European Directive to survey the risk of lead poisoning (Council Directive, 1977), a random sample of 321 residents was selected from the Vosgian Mountains of France. This region is noted for its high incidence of cases of lead poisoning: 150 reported during 8 months in 1983 (Barbier et al., 1983).During the course of a health evaluation, a blood sample was taken from each subject for lead analysis. At the same time, a sample of tap-water (after running for 5 s) was taken from each subject home. Both lead analyses (blood and water) were performed by electrothermal atomization-atomic absorption spectrophotometry. Because of the log-normality of the distributions of the blood lead levels and the concentrations of lead in the drinking water, a logarithmic transformation was performed so that the results are expressed as the geometric mean, which for the amount of lead in the drinking water of our sample was found to be 0.16 mg l^?1.Among the subjects of this study, 28% are served by water containing more than 0.10 mg l^?1 of lead (the standard for France) and 48% by water containing more than 0.05 mg l^?1 (the European and WHO standard). In concurrence with numerous authors, our study indicates that, among our subjects, the blood lead level is much higher in men than in women (geometric means 22.9 and 15.0 μg dl^?1 respectively); this difference is highly significant (t-test:P < 0.001). Table 1 summarizes the results, by sex, obtained in this region compared with those from a study (Huel, 1982) concerning an urban French population whose geometric mean blood lead levels were 15.9 μg dl^?1 for men and 11.4 μg dl^?1 for women. The irrespective of sex, is highly significant (P < 0.001). Table 2 shows the significance of the relation between these subjects, high blood lead levels and the concentration of lead in their drinking water, while Fig. 1 shows that for contamination levels up to 0.02 mg l^?1 of lead in water, the blood lead level remains relatively stable, while above this apparent “threshold” value, the blood lead level begins to increase finally reaching quite high values in response to high contamination levels, suggesting a direct translation of increases in the water above the 0.02 mg l^?1 level to increases in the blood.