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- Balmer, Marianne E, et al.
(författare)
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Occurrence of Methyl Triclosan, a Transformation Product of the Bactericide Triclosan, in Fish from Various Lakes in Switzerland
- 2004
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Ingår i: Environmental Science & Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 38:2, s. 390-5
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Tidskriftsartikel (refereegranskat)abstract
- The bactericide triclosan and methyl triclosan, an environmental transformation product thereof, have been previously detected in lakes and a river in Switzerland. Both compounds are emitted via wastewater treatment plants (WWTPs), with methyl triclosan probably being formed by biological methylation. Passive sampling with semipermeable membrane devices (SPMDs) showed the presence of methyl triclosan in some lakes, suggesting some potential for bioaccumulation of the compound. In this study, we report the presence of methyl triclosan in fish (white fish, coregonus sp.; roach, rutilus rutilus) from various lakes in Switzerland receiving inputs from WWTPs. Identification of the compound was based on mass spectral (MS) evidence including MS/MS data. The concentrations of methyl triclosan in the fish were up to 35 ng g-1 on a wet weight basis and up to 365 ng g-1 on a lipid basis with concentrations in a relatively narrow range for fish from the same lake (Thunersee, 4-6 ng g-1; Zürichsee, 32-62 ng g-1; Pfäffikersee, 43-56 ng g-1; Greifensee, 165-365 ng g-1, lipid basis). No methyl triclosan (<1 ng g-1, lipid basis) was detected in fish (lake trout, salmo trutta) from a remote lake in Sweden (Häbberstjärnen) and in fish (roach) from a small lake in Switzerland with no input from WWTPs (Hüttnersee, <2-<5 ng g-1, lipid basis). The concentrations of methyl triclosan in fish correlated (r2 = 0.85) with the ratio of population in the watershed to water throughflow of the lakes (P/Q ratio), which is considered to be a measure for the domestic burden from WWTPs to a lake. Passive sampling with SPMDs confirmed the presence of methyl triclosan in lakes and a river (Zürichsee and Greifensee; Limmat) but not in a remote mountain lake (Jörisee) and in Hüttnersee. The bioconcentration factor (BCF) of methyl triclosan estimated from the fish data and SPMD-derived water concentrations was in the order of 1-2.6 × 105 (lipid basis) and thus in the range of other persistent organic pollutants. SPMDs were found to be reliable for monitoring low concentrations of methyl triclosan in surface water. Methyl triclosan appears to be a suitable marker for WWTP-derived lipophilic contaminants in the aquatic environment and fish.
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| 5. |
- Henriksson, Anders E., et al.
(författare)
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Steal syndrome after brachiocephalic fistula for vascular access : correction with a new simple surgical technique.
- 2004
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Ingår i: Journal of Vascular Access. - 1129-7298 .- 1724-6032. ; 5:1, s. 13-5
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: Steal syndrome is the condition of arterial insufficiency distal to a permanent haemodialysis fistula. Three treatment options have been recommended: ligation of the fistula, banding of the fistula, and distal revascularization. We report an alternative simple surgical technique for correction of steal syndrome.METHODS: Two patients were treated for steal syndrome after brachiocephalic fistula operation. The treatment of the steal syndrome was done by interponating an ePTFE graft loop tunnelated subcutaneously in the upper arm.RESULTS: At follow-up one year later both fistula were patent without any reoperation and with normal flow at haemodialysis. There were no symptoms of steal.CONCLUSION: This new method for correction of steal syndrome seems to be an attractive alternative.
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| 6. |
- Henriksson, Anders E., et al.
(författare)
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Steal syndrome of the hemodialysis vascular access : diagnosis and treatment.
- 2004
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Ingår i: Journal of Vascular Access. - 1129-7298 .- 1724-6032. ; 5:2, s. 62-8
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Forskningsöversikt (refereegranskat)abstract
- PURPOSE: Steal syndrome is an uncommon but serious condition of arterial insufficiency distal to a permanent hemodialysis fistula. The management of the condition is a great challenge to the surgeon because of the conflicting goals of preserving the fistula and treat the ischemia. In this review the purpose was to analyze the clinical problem and treatment possibilities.METHODS: Medline and Embase databases were searched for studies relevant to diagnosis and management of steal syndrome of the hemodialysis vascular access.RESULTS: The diagnosis of steal syndrome is largely based on clinical features and non-invasive studies. In same cases angiography may be necessary to find out the real causes of the steal syndrome. The cause is usually high fistula flow but other causes as steal phenomenon, inflow, outflow or anastomotic stenosis have to be considered and even combination of causes. The main treatment options are some form of flow reducing procedure or the distal revascularization interval ligation method. In some cases simple distal arterial ligation is the method of choice. Furthermore, in some patients a stenosis has to be treated as the first treatment option.CONCLUSIONS: For an appropriate treatment of a steal syndrome a careful analysis of the cause is important.
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| 8. |
- Lizzaraga, R., et al.
(författare)
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Conditions for Noncollinear Instabilities of Ferromagnetic Materials
- 2004
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Ingår i: Physical Review Letters. - : American Physical Society (APS). - 0031-9007 .- 1079-7114. ; 93:10, s. 107205-
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Tidskriftsartikel (refereegranskat)abstract
- Two criteria have been identified here which determine whether a magnetic metal orders in a collinear (e.g., ferromagnet) or noncollinear (e.g., spin-spiral) arrangement. These criteria involve the ratio between the strength of the exchange interaction and the width of the electron bands, as well as Fermi-surface nesting between spin-up and spin-down sheets of the Fermi surface. Based on our analysis we predict that even typical ferromagnetic materials (e.g., Fe, Co, and Ni) should be possible to stabilize in a noncollinear magnetic order in, e.g., high pressure experiments.
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| 10. |
- Poiger, Thomas, et al.
(författare)
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Occurrence of UV filter compounds from sunscreens in surface waters: regional mass balance in two Swiss lakes
- 2004
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535. ; 55:7, s. 951-63
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Tidskriftsartikel (refereegranskat)abstract
- Consumer care products often contain UV filters, organic compounds which absorb ultraviolet light. These compounds may enter surface waters directly (when released from the skin during swimming and bathing) or indirectly via wastewater treatment plants (when released during showering or washed from textiles). Predicted and measured UV filter concentrations were compared in a regional mass balance study for two Swiss lakes: Lake Zurich, a typical midland lake which is also an important drinking water resource, and Hüttnersee, a small bathing lake. Both lakes are extensively used for recreational activities and considerable direct input of UV filters is thus expected. This input was estimated from the number of visitors at swimming areas around the lakes and a survey of the usage of sunscreen products among these visitors. Possible additional indirect input via wastewater treatment plants was not considered in this study. The quantitatively most important UV filters, as indicated by the survey data, ethylhexyl methoxycinnamate, octocrylene, 4-methylbenzylidene camphor, butyl methoxydibenzoylmethane, and benzophenone-3, all lipophilic compounds, were selected for analysis by gas chromatography–mass spectrometry. Concentrations of individual UV filters in water from Lake Zurich were low, ranging from <2 ng l−1 (detection limit) to 29 ng l−1, and somewhat higher at Hüttnersee, ranging from <2 to 125 ng l−1, with the highest concentrations found in summer, consistent with direct inputs to the lakes during this time. The concentrations were clearly lower than predicted from input estimates based on the surveys. This may be in part due to (i) an overestimation of these inputs (e.g. less than the 50% wash-off of UV filters assumed to occur during swimming), and (ii) some removal of these compounds from the lakes by degradation and/or sorption/sedimentation. UV filters were also detected in semipermeable membrane devices (SPMDs) deployed at Lake Zurich and Greifensee, another midland lake, at concentrations of 80–950 ng SPMD−1, confirming the presence of the compounds in surface waters and indicating a certain potential for bioaccumulation. SPMD-derived water concentrations were in the range of 1–10 ng l−1 and thus corresponded well with those determined in water directly. No UV filters were detected above blank levels in SPMDs deployed at a remote mountain lake used for background measurements.
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