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- Yeung, Leo W. Y., 1981-, et al.
(författare)
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Biochemical Responses and Accumulation Properties of Long-Chain Perfluorinated Compounds (PFOS/PFDA/PFOA) in Juvenile Chickens (Gallus gallus)
- 2009
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Ingår i: Archives of Environmental Contamination and Toxicology. - : Springer. - 0090-4341 .- 1432-0703. ; 57:2, s. 377-386
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Tidskriftsartikel (refereegranskat)abstract
- One-day-old male chickens were exposed via oral gavage to mixtures of perfluorooctane sulfonate (PFOS), perfluorooctanoate (PFOA), and perfluorodecanoate (PFDA) at either a low dose (0.1 mg/kg body weight [b.w.]) or a high dose (1.0 mg/kg b.w.), or a saline/ethanol vehicle control, three times a week for 3 weeks. After 3 weeks of exposure, half of the chicks were sacrificed and the other half were allowed to depurate for a further 3 weeks. No dose-dependent statistically significant differences in body/organ weights were observed among treatment and control groups after 3 weeks of exposure or after three 3 of depuration. Neither 15 histological nor 14 measured plasma biochemical parameters were significantly different in chicks from the exposed groups and vehicle controls. PFOS, PFDA, and PFOA concentrations in blood/liver/kidney samples were measured throughout the exposure and depuration periods at different time intervals. PFOS and PFDA accumulated at much higher concentrations than PFOA during the experimental periods. Interestingly, PFOS and PFDA accumulation patterns in the blood were similar during the exposure and depuration periods. The half-lives for each PFC at the 0.1 and 1.0 mg/kg doses were, respectively, approximately 15 and 17 days for PFOS, 11 and 16 days for PFDA, and 3.9 and 3.9 days for PFOA. PFDA accumulation in organs was greater than or similar to that of PFOS: the liver was the main target during exposure and the blood was the main reservoir during depuration. These results indicate that exposure to a 1.0-mg mixture of PFOS/PFDA/PFOA/kg b.w. has no adverse effect on juvenile chickens.
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| 4. |
- Genuneit, J., et al.
(författare)
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A multi-centre study of candidate genes for wheeze and allergy : the International Study of Asthma and Allergies in Childhood Phase 2
- 2009
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Ingår i: Clinical and Experimental Allergy. - : John Wiley & Sons. - 0954-7894 .- 1365-2222. ; 39:12, s. 1875-1888
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Common polymorphisms have been identified in genes suspected to play a role in asthma. We investigated their associations with wheeze and allergy in a case-control sample from Phase 2 of the International Study of Asthma and Allergies in Childhood.METHODS: We compared 1105 wheezing and 3137 non-wheezing children aged 8-12 years from 17 study centres in 13 countries. Genotyping of 55 candidate single nucleotide polymorphisms (SNPs) in 14 genes was performed using the Sequenom System. Logistic regression models were fitted separately for each centre and each SNP. A combined per allele odds ratio and measures of heterogeneity between centres were derived by random effects meta-analysis.RESULTS: Significant associations with wheeze in the past year were detected in only four genes (IL4R, TLR4, MS4A2, TLR9, P<0.05), with per allele odds ratios generally <1.3. Variants in IL4R and TLR4 were also related to allergen-specific IgE, while polymorphisms in FCER1B (MS4A2) and TLR9 were not. There were also highly significant associations (P<0.001) between SPINK5 variants and visible eczema (but not IgE levels) and between IL13 variants and total IgE. Heterogeneity of effects across centres was rare, despite differences in allele frequencies.CONCLUSIONS: Despite the biological plausibility of IgE-related mechanisms in asthma, very few of the tested candidates showed evidence of association with both wheeze and increased IgE levels. We were unable to confirm associations of the positional candidates DPP10 and PHF11 with wheeze, although our study had ample power to detect the expected associations of IL13 variants with IgE and SPINK5 variants with eczema.
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| 6. |
- Hong, Seung-Sun, et al.
(författare)
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TCPtransform : Property-Oriented TCP Traffic Transformation
- 2005
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Konferensbidrag (refereegranskat)abstract
- A TCPdump file captures not only packets but also various "properties" related to the live TCP sessions on the Internet. It is still an open problem to identify all the possible properties, if ever possible, and more importantly, which properties really matter for the consumers of this particular TCPdump file and how they are related to each other. However, it is quite clear that existing traffic replay tools, for the purpose of system evaluation, such as TCPreplay destroyed at least some of critical properties such as "ghost acknowledgment" (while the origin packet has never been delivered), which is a critical issue in conducting experimental evaluations for intrusion detection systems. In this paper, we present a software tool to transform an existing TCPdump file into another traffic file with different "properties". For instance, if the original traffic is being captured in a laboratory environment, the new file might "appear" to be captured in between US and Sweden. The transformation we have done here is "heuristically consistent" as there might be some hidden properties still being destroyed in the transformation process. One interesting application of our tool is to build long-term profiles to detect anomalous TCP attacks without really running the target application over the Internet. While, in this paper, we only focus on property-oriented traffic transformation, we have built and evaluated an interactive version of this tool, called TCPopera, to evaluate commercial intrusion prevention systems.
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| 7. |
- Hsieh, Yves S-Y, et al.
(författare)
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Structure and bioactivity of the polysaccharides in medicinal plant Dendrobium huoshanense
- 2008
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Ingår i: Bioorganic & Medicinal Chemistry. - : Elsevier. - 0968-0896 .- 1464-3391. ; 16:11, s. 6054-68
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Tidskriftsartikel (refereegranskat)abstract
- Detailed structures of the active polysaccharides extracted from the leaf and stem cell walls and mucilage of Dendrobium huoshanense are determined by using various techniques, including chromatographic, spectroscopic, chemical, and enzymatic methods. The mucilage polysaccharide exhibits specific functions in activating murine splenocytes to produce several cytokines including IFN-gamma, IL-10, IL-6, and IL-1alpha, as well as hematopoietic growth factors GM-CSF and G-CSF. However, the deacetylated mucilage obtained from an alkaline treatment fails to induce cytokine production. The structure and bioactivity of mucilage components are validated by further fractionation. This is the first study that provides clear evidence for the structure and activity relationship of the polysaccharide in D. huoshanense.
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| 8. |
- Leyser, Thomas B., et al.
(författare)
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Powerful electromagnetic waves for active environmental research in geospace
- 2009
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Ingår i: Reviews of geophysics. - 8755-1209 .- 1944-9208. ; 47, s. RG1001-
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Forskningsöversikt (refereegranskat)abstract
- Powerful electromagnetic (EM) waves can exert well-defined influence on the atmosphere, ionosphere, and magnetosphere. These active EM interactions can provide spatiotemporal information on the near-Earth space environment (geospace). Objectives include remote monitoring and controlling of a wide range of parameters of geospace, controlling properties of the ionosphere and magnetosphere, as well as interaction with large-scale natural energy sources. In addition, applications such as mitigation of atmospheric pollutants and solar power satellites are discussed. Studies of EM wave interactions also contribute to the knowledge of anthropogenic effects in the geospace environment, such as the increasing use of EM radiation.
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| 10. |
- Slotte, J., et al.
(författare)
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Fluence, flux, and implantation temperature dependence of ion-implantation-induced defect production in 4H-SiC
- 2005
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 97:3
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Tidskriftsartikel (refereegranskat)abstract
- Vacancy-type defect production in Al- and Si-implanted 4H-SiC has been studied as a function of ion fluence, ion flux, and implantation temperature in the projected ion range region by positron annihilation spectroscopy and Rutherford backscattering techniques. Ion channeling measurements show that the concentration of displaced silicon atoms increases rapidly with increasing ion fluence. In the ion fluence interval of 10(13)-10(14) cm(-2) the positron annihilation parameters are roughly constant at a defect level tentatively associated with the divacancy VCVSi. Above the ion fluence of 10(14) cm(-2) larger vacancy clusters are formed. For implantations as a function of ion flux (cm(-2) s(-1)), ion channeling and positron annihilation measurements behave similarly, i.e., indicating increasing damage in the projected range region with increasing ion flux. However, for samples implanted at different temperatures the positron annihilation parameter S shows a clear minimum at approximately 100 degreesC, whereas the normalized backscattering yield decrease continuously with increasing implantation temperature. This is explained by the formation of larger vacancy clusters when the implantation temperature is increased.
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