| 31. |
- Nilsson, Ulrika
(författare)
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Kampen om Kvinnan : Professionalisering och konstruktioner av kön i svensk gynekologi 1860-1925
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis investigates how gynaecology was established as a medical speciality in Sweden in the 1860s and onwards. Gender, power, professionalisation and the production of scientific knowledge are central themes. While previous research has shown that gynaecology as a discipline depends upon notions of Woman as radically different from Man, I show how this was manifested within Swedish gynaecology, an initially all male environment. Of special interest is institutionalisation, early career-paths and the development of therapy methods and theory. I argue that gynaecology reproduced and contributed to notions of sex-difference and a gender complementary way of thinking.While gynaecology was formed as a surgically interventionist speciality with strong manly connotations, an education reform aiming at opening higher education to women was simultaneously discussed and eventually carried out during the 1860s and 70s. The advocates of this reform portrayed women as especially fit for becoming teachers and physicians, particularly treating women and children. Thus, two opposing gendered professional ideals operated. By focusing an elite group of early women physicians, I outline how the gynaecological construction of womanliness related to women physicians and how women physicians engaged with this notion: what strategies they used to enter a profession as manly as gynaecology had become; and how women gynaecologists engaged with their men colleagues’ therapeutic methods and views on patients and women.
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| 32. |
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| 33. |
- Nordqvist, Yvonne, et al.
(författare)
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Comparison of denuder and impinger sampling for determination of gaseous toluene diisocyanate (TDI)
- 2001
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Ingår i: Fresenius´ Journal of Analytical Chemistry. - Berlin : Springer. - 0937-0633 .- 1432-1130. ; 371:1, s. 39-43
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Tidskriftsartikel (refereegranskat)abstract
- An air-sampling method employing denuders coated inside with a chemisorptive stationary phase has been evaluated for analysis of the hazardous gaseous 2,4 and 2,6 isomers of toluene diisocyanate (TDI). The denuder stationary phase consisted of polydimethylsiloxane (SE-30) to which dibutylamine (DBA) was added as a reagent for derivatization of TDI. The accuracy and precision of sampling by means of denuders were shown to differ only slightly from those of the established impinger method. The denuder method was, however, also shown to be suitable for long-term measurements (up to 8 h). The limit of determination (LOD) of the method, including LC-APCI-MS-MS analysis, was found to be 1.9 µg m-3 and 1.2 µg m-3 for 2,4- and 2,6-TDI, respectively, for short-term measurements (15 min). Significant lower LOD was obtained for long-term measurements.This is well below the Occupational Safety and Health Administration (OSHA) 8-h TWA (time weighted average) exposure limit, which is 40 µg m-3 for the sum of the TDI isomers. The denuder method was also found to be robust and easy to handle. The samplers can be prepared several days before sampling with no loss in performance. The contents of denuders should, on the other hand, be extracted immediately after sampling to prevent degradation of the isocyanate derivatives formed.
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| 34. |
- Nordqvist, Yvonne, 1975-
(författare)
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Development and Evaluation of a Denuder-Filter System Designed for Sampling Diisocyanate Aerosols
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- There are many occupational environments in which isocyanates or PUR-products are used, produced or processed. During these operations there is always a risk of isocyanate exposure, which may lead to severe health problems. Isocyanates principally affect the respiratory system and they are the main cause of occupational asthma. The prevalence of asthma among exposed workers is generally 5-10%, according to most studies, but figures as high as 30% have been reported.The most commonly used isocyanates may occur in both vapour and particulate forms. Their physical state may affect both their deposition in the airways and their impact on health. Nevertheless, the occupational exposure limit for isocyanates applies to the total amount of isocyanates present, regardless of their physical state. Setting different exposure limits for vapour and particles would require the air sampling step to be capable of separating and independently measuring the phases. This is not straightforward, since every sampling method may be affected by a number of possible sampling artefacts. To minimize such biases, a profound knowledge of the sampling system and its behaviour is required.In this thesis a chemosorptive cylindrical denuder and filter, connected to a sampling pump, has been developed for personal exposure measurements of isocyanates. The model compounds for the investigation and evaluation were some of the most commonly used diisocyanates in industry: toluene diisocyanate (TDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI) and methylene diphenyl diisocyanate (MDI). Using a combination of dimethylpolysiloxane (SE-30) and dibutylamine (DBA) as a chemosorptive coating on both the inner wall of the denuder tube and the filter, the derivatisation was shown to be fast enough for efficient collection of the isocyanates. The repeatability of the air measurements was high, with variabilities generally between 5-10% in the measured concentration range. 15-min samplings were performed of both vapour and aerosols of nm-size, from below the OEL (5ppbv) up to 235 ppbv, without exceeding the coating capacity or causing breakthrough due to chromatographic movement. At the applied airflow rates, between 50 and 500 ml/min, the breakthrough, i.e. the percentage of the TDI vapour that passes through the denuder tube ending up on the filter, was shown to be consistent with amounts predicted by the Gormley-Kennedy equation. For isocyanate aerosols, extensive gas-stripping was shown to occur inside the denuder tube at the lower end of the investigated flow range. This phenomenon was minimized when a flow rate between 300 and 500 ml/min was applied (Papers III-IV).The great advantage of a denuder sampler compared to wet methods, such as the commonly used impinger method, is its suitability for personal exposure measurements. Due to its small size and absence of solvent it is more convenient to carry during a work shift. Furthermore, the results in Paper II indicate that 8-hour denuder measurements can be performed without detectable breakthrough of the vapour phase. The derivatives formed during the sampling of isocyanates were shown to be stable in the samplers for several days after the measurements were finished, provided both the denuder tubes and filters were stored in the freezer and in solvent containing excess reagent. Furthermore, filters and tubes could be prepared at least 4 d prior to sampling, without loss of performance. This is highly relevant to the applicability of the method for field measurements.Both LC-ESI-MS (Paper II-IV) and LC-APCI-MS (Paper I) were used to determine the analytes in the air samples. The former method exhibited the lowest detection limit for the isocyanate-DBA derivatives. Using selected reaction monitoring (SRM) the obtained method detection limit for the investigated compounds was below 10 ng/m3.
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| 35. |
- Nordqvist, Yvonne, et al.
(författare)
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Evaluation of denuder sampling for a mixture of three common gaseous diisocyanates
- 2003
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Ingår i: Analytical and bioanalytical chemistry. - Berlin : Springer. - 1618-2642. ; 375:6, s. 786-791
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Tidskriftsartikel (refereegranskat)abstract
- A denuder sampler has been evaluated for a mixture of three gaseous diisocyanates, i.e. toluene diisocyanate (TDI), hexamethylene diisocyanate (HDI) and isophorone diisocyanate (IPDI). Sampling was performed at a total concentration of diisocyanates close to the Swedish occupational exposure limit (OEL), which is 10 ppbv (69–92 µg m–3), for a 5-min period. The denuder tube was coated with a chemosorptive stationary phase consisting of SE-30 (polydimethylsiloxane) and the derivatising reagent dibutylamine (DBA). It was shown that the denuder has a collection efficiency for HDI and IPDI comparable to that of an impinger method, while sampling of TDI resulted in an 8% lower concentration. Both short-term (15 min) and long-term (8 h) sampling periods were shown to yield reproducible results. For 8-h measurements, a sampling flow rate of 5 mL min–1 was shown to be suitable for the investigated concentration range, i.e. 10–100 ppbv (69–921 µg m–3). A flow rate of 25 mL min–1 or higher resulted in breakthrough after 8 h due to chromatography of the compounds in the adsorbent. The limit of detection (LOD) for the air sampling method is nearly 500 times lower than the OEL. The denuder tubes can be prepared at least 10 days prior to sampling without degradation of performance. Furthermore, they can be stored up to 6 days in a freezer after sampling without significant loss of analytes.
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| 36. |
- Nygren, Ulrika, et al.
(författare)
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Separation of plutonium from soil and sediment prior to determination by inductively coupled plasma mass spectrometry
- 2003
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Ingår i: Journal of Analytical Atomic Spectrometry. - 0267-9477 .- 1364-5544. ; 18:12, s. 1426-1434
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this work was to develop an optimised sample-preparation procedure for the determination of Pu in soil/sediment with ICP-MS. To start with, several different procedures were screened for their ability to separate plutonium and remove uranium. After the screening, two methods were applied on one soil (IAEA Soil6) and two sediment reference materials (IAEA300 and IAEA135). These methods were based on separation of Pu using TEVA and a combination of UTEVA and TRU resins, followed by elution of Pu with 0.1% hydroxylethylidene diphosphonic acid (HEDPA). A comparison was also made between sample preparation based on acid-leaching and complete digestion using lithium borate fusion. The highest yield of Pu (80%) was found with the procedure consisting of fusion followed by TEVA, while the decontamination from U showed large variations (RSD varying from 16–52%) with all procedures. No difference in the recovery of Pu was found between the two sample preparation techniques. The results of the quantitative determination in low resolution of 239Pu and 240Pu from the UTEVA + TRU-separation were significantly higher than those obtained by the TEVA procedure. An analysis in higher mass resolution displayed interfering peaks in the mass-region of Pu, and lanthanide-containing polyatomic ions were found to be a likely cause for these interferences. The procedure based on lithium borate fusion and separation using the TEVA-resin avoided such interferences and was therefore tested for repeatability over time on IAEA300. The stability of the method was good (RSD = 2.49% (n = 8)), with the exception of one value being significantly higher than the others. This result was confirmed by analysis in higher mass-resolution, which indicates an inhomogeneous distribution of Pu in the reference material, despite a sample intake of about 1 g.
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| 37. |
- Postgård, Per, et al.
(författare)
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Stunning of iodide transport by (131)I irradiation in cultured thyroid epithelial cells.
- 2002
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Ingår i: Journal of nuclear medicine : official publication, Society of Nuclear Medicine. - 0161-5505. ; 43:6, s. 828-34
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Tidskriftsartikel (refereegranskat)abstract
- The existence of thyroid stunning (i.e., inhibited thyroidal iodide uptake after administration of diagnostic amounts of (131)I) is controversial and is currently a subject of debate. To our knowledge, the stunning phenomenon has not been investigated previously in vitro. METHODS: Growth-arrested porcine thyroid cells that formed a tight and polarized monolayer in a bicameral chamber were irradiated with 3-80 Gy (131)I present in the surrounding culture medium for 48 h. The iodide transport capacity after irradiation was evaluated 3 d later by measuring the transepithelial (basal to apical) flux of trace amounts of (125)I. RESULTS: The basal-to-apical (125)I transport decreased with increasing absorbed dose acquired from (131)I; a nearly 50% reduction was observed already at 3 Gy. Stable iodide at the same molarity as (131)I (10(-8) mol/L) had no effect on the (125)I transport. Cell number and epithelial integrity were not affected by irradiation. CONCLUSION: Stunning of iodide transport is detected after (131)I irradiation of cultured thyroid cells. The degree of inhibition of transport is dependent on the absorbed dose.
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| 38. |
- Wallander, Håkan, et al.
(författare)
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Direct estimates of C : N ratios of ectomycorrhizal mycelia collected from Norway spruce forest soils
- 2003
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Ingår i: Soil Biology & Biochemistry. - 0038-0717. ; 35:7, s. 997-999
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Tidskriftsartikel (refereegranskat)abstract
- Direct estimates of C:N ratios of ectomycorrhizal (EM) mycelia growing in situ in forest soils have been obtained for the first time. The mycelial samples were collected from sand-filled mesh bags that were buried in the soil and incubated for 12-18 months in two Norway spruce forests in southern Sweden. At harvest the mesh bags were heavily colonized and the mycelia were extracted from the sand with water. The collected mycelia had earlier been identified as belonging to EM fungi based on their C isotopic composition. The mean value of the C:N ratio for mycelia was 20.2 +/- 0.8 (n = 25). EM mycelia collected at different soil depths (5, 15 and 30 cm) had similar C:N ratios. C:N ratios of microbial biomass obtained by fumigation - extraction of similar soils have usually been lower (6-13) so possible differences in the extraction efficiency of C and N from bacteria and fungi are discussed.
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