Assessment of chlorinated pesticides and polychlorinated biphenyls in adipose breast tissue using a supercritical fluid extraction method

A precise and highly reproducible analytical method was developed for the assessment of organochlorinated pesticide and polychlorinated biphenyl residues in adipose tissue (> or = 50 mg). The method can be utilized for epidemiological studies on the significance of these environmental pollutants in the etiology of breast cancer. Supercritical fluid extraction (SFE) with CO2 and modified CO2 (addition of 5% dichloromethane) is employed to remove incurred pesticide residues from adipose tissues that have been surgically removed from breast cancer patients and controls. An alumina sorbent, placed in the extracting vessel together with a specimen, removes the bulk of co-extracted lipids; a subsequent purification of the SFE extracts by column chromatography on alumina removes the remaining traces of lipids that would interfere with the gas chromatographic analysis with electron capture detection. The method was tested by analyzing a Certified Reference Material 430 pork fat with known amounts of pesticide residues that are commonly found in fat or in foods with a high fat content. The recoveries of analytes ranged from 73.4% for endrin to 115% for alpha-, beta- and gamma-hexachlorocyclohexane, hexachlorobenzene and dieldrin, with standard deviations of 4-12% for individual analytes. The analysis of adipose tissue for organochlorinated compounds on the basis of this new method suggested that the pesticide levels were higher in breast cancer patients than in controls. However, the small number of samples analyzed in this study (n = 5, both groups) precludes definitive conclusions. The most abundant compounds in both cases and controls were p, p-DDE (379 +/- 286 and 160 +/- 149 p.p.b.) and PCB (223 +/- 145 and 124 +/- 65.7 p.p.b.), followed by the termiticide chlordane residues oxychlordane and transnonachlor

DEVELOPMENT OF A MULTI-DOSE FORMULATION FOR PREVNAR 13™

Streptococcus pneumoniae causes up to a million cases per year of invasive disease in young children and infants, most occurring in developing countries. Pfizer is partnering with WHO and the GAVI alliance to support the developing world on immunization against pneumococcal disease. Prevnar 13™ is currently approved for the prevention of invasive pneumococcal disease in twenty seven countries. If used widely, this pneumococcal conjugate vaccine could prevent hundreds of thousands of additional cases of child mortality each year. Use of single-dose preservative-free vaccine formulations will raise the overall cost of vaccination programs and may jeopardize the effectiveness of immunization programs in developing countries. Multi-dose vials lower the cost for each vaccination but typically need to include a preservative to prevent contamination that might be introduced during the withdrawal of vaccine doses from such vials. To develop a multi-dose formulation of Prevnar 13™ for the developing world, a preservative effective in meeting antimicrobial efficacy test requirements, that would maintain vaccine stability, and have an established safety record in infants was required. Multiple preservatives which include phenol, 2-phenoxyethanol (2-PE), meta-cresol, methylparaben and propyl paraben and thimerosal (as a control) were evaluated as potential candidates for a multi-dose formulation of Prevenar 13 based on preservative effectiveness and product stability. 2-PE showed superior antimicrobial effectiveness in Prevnar 13 formulations as per European Pharmacopoeia (EP) requirements and in multiple challenge studies with various organisms, as per WHO Open Vial Policy, to mimic worst case inadvertent microbial contamination that might occur during immunization of subjects when the formulation is presented in multi-dose vials. Prevnar 13 in the presence of 5mg dose of 2-PE is stable for over two years and meets the preservative effectiveness standards based on the EP 5.1.3 as well as WHO multi-organism challenge test. The data support the use of 2-PE as a more effective preservative with the potential to replace thimerosal, the most commonly used preservative in multi-dose vaccine formulations

Orco mediates olfactory behaviors and winged morph differentiation induced by alarm pheromone in the grain aphid, Sitobion avenae

Olfaction is crucial for short distance host location and pheromone detection by insects. Complexes of olfactory receptors (ORs) are composed of odor-specific ORs and OR co-receptors (Orco). Orcos are widely co-expressed with odor-specific ORs and are conserved across insect taxa. A number of Orco orthologs have been studied to date, although none has been identified in cereal aphids. In this study, an Orco gene ortholog was cloned from the grain aphid, Sitobion avenae, and named “SaveOrco”; RNA interference (RNAi) reduced the expression of SaveOrco to 34.11% in aphids, resulting in weaker EAG (electroantennogram) responses to plant volatiles (Z-3-hexene-1-ol; methyl salicylate, MeSA) and aphid alarm pheromone (E-b-farnesene, EBF). Aphid wing differentiation induced by EBF was investigated in both RNAi treated and untreated aphids. EBF induced production of winged aphids in both pre-natal and postnatal periods in untreated aphids, but no such induction was observed in the RNAi-treated aphids. We conclude that SaveOrco is crucial for the aphid's response to pheromones and other volatiles, and is involved in wing differentiation triggered by EB

Detection of urban hidden faults using group-velocity ambient noise tomography beneath Zhenjiang area, China

Abstract The Mufushan-Jiaoshan fault (MJF) is a hidden active fault located on the north side of the Ningzhen Mountain Range and developed along the Yangtze River in Zhenjiang area, China. In this paper, the structure of MJF is detected and studied using group-velocity ambient noise tomography. In the study area (18 km × 25 km), 47 short-period seismic stations were deployed with the average station spacing of about 3 km and 24 days (from 27 February to 22 March 2019) of continuous ambient-noise recordings were collected. And 510 group velocity dispersion curves in the period band 0.5–5 s were extracted using the vertical component data. And then the three-dimensional shear-wave velocity structure was inverted using group dispersion data by the direct surface-wave tomographic method. Our results are consistent with the geological background of the study area, showing that in the depth range of 0.6–1.5 km, the north side of MJF presents a relatively high velocity, and the south side presents a distribution pattern of high and low velocity. While in the depth range of 1.5–2.0 km, the shear-wave velocity (Vs) model is relatively simple with relatively low velocity on the north side and relatively high velocity on the south side. And the gradient zone of Vs may be the location of the main fracture surface of MJF. The good correspondence between the Vs model and the fault structure indicates that the ambient noise tomography method can be used as an effective method for detecting hidden faults in urban environments

synthesisofsapo35molecularsieveanditscatalyticpropertiesinthemethanoltoolefinsreaction

以六亚甲基亚胺为模板剂,采用水热法合成了不同硅含量的磷酸硅铝分子筛SAPO-35,并利用X射线衍射、X射线荧光光谱、扫描电镜、固体核磁、X射线光电子能谱和N2吸附-脱附等方法对样品进行了表征.研究了不同硅含量的SAPO-35分子筛在甲醇转化制烯烃反应中的催化行为,同时对比分析了具有相近硅含量的SAPO-35和SAPO-34分子筛在甲醇转化反应过程中积炭物种随反应时间的演变特征,尝试将分子筛结构和其积炭失活行为进行了关联

Synthesis of mesoporous ZSM-5 catalysts using different mesogenous templates and their application in methanol conversion for enhanced catalyst lifespan

In this work, two kinds of mesoporous ZSM-5 were synthesized successfully using a hydrothermal methodology by utilizing different soft templates, namely, dimethyl octadecyl [3-(trimethoxysilyl) propyl] ammonium chloride ([(CH3O)(3)SiC3H6N(CH3)(2)C18H37]Cl, TPOAC) and hexadecyl trimethyl ammonium bromide (C16H33(CH3)(3)NBr, CTAB). The obtained mesoporous ZSM-5 samples were compared with conventional ZSM-5, and the effects of different surfactant usages during the synthesis of mesoporous ZSM-5 on the physicochemical and catalytic properties were systematically investigated. Multiple techniques, such as XRD, SEM, N-2 adsorption techniques, HP Xe-129 NMR, Al-27 MAS NMR, Si-29 MAS NMR, and H-1 MAS NMR, were employed for the characterization. Although the synthesized mesoporous ZSM-5 samples had equal surface areas, they presented different relative crystallinities, morphologies, pore-size distributions, micropore-mesopore interconnectivity, framework atom coordination states and acidities. When using these synthesized ZSM-5 samples as catalysts for methanol conversion, the mesoporous ZSM-5 templated with TPOAC exhibited an extremely long catalyst lifespan compared to conventional ZSM-5, while mesoporous ZSM-5 templated with CTAB showed no advantage in prolonging the catalyst lifetime during the reaction. The differences in the catalytic lifespan and the reduction of coke deposition were correlated to the variation of acidity and porosity with the mesopore generation in the ZSM-5 catalysts by the usage of different structure-directing agents. Compared to the mesopore structure-directing agent, CTAB, with the use of TPOAC as the template and part of the Si source, mesoporous ZSM-5 could be synthesized with good mesopore-micropore interconnectivity, which accounted for the improved catalytic performance in the reaction of methanol conversion

Synthesis of mesoporous ZSM-5 using a new gemini surfactant as a mesoporous directing agent: A crystallization transformation process

A new gemini surfactant, [C18H37(CH3)(2)-N+-(CH2)(3)-N+-(CH3)(2)C18H37]Cl-2 (C18-3-18), has been successfully used as the mesopore directing agent in the hydrothermal synthesis of mesoporous ZSM-5 (MZSM-5). The synthesis of MZSM-5 was realized with a low temperature crystallization process at 130 degrees C. The amount of C18-3-18 used in the synthesis affected the relative crystallinity and the textural properties of the obtained MZSM-5. Detailed investigation showed that the formation of MZSM-5 followed a crystallization transformation process. The use of C18-3-18 resulted in the formation of mesoporous material during the early stage of the synthesis, which was converted into MZSM-5 crystals templated by tetrapropylammonium bromide to form the MFI phase. As the synthesis proceeded, the MZSM-5 crystals aggregated into particles by weak interactions. This work shows that C18-3-18 can be used as a mesopore directing agent, which could provide a route for the synthesis of other mesoporous zeolites. (C) 2014, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved