| 1. |
- Antelmi, Annarita, et al.
(författare)
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4,4′-Thiobis(2-tert-butyl-5-methylphenol), an antioxidant in medical devices that may cause allergic contact dermatitis
- 2023
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Ingår i: Contact Dermatitis. - 0105-1873. ; 89:2, s. 103-106
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Tidskriftsartikel (refereegranskat)abstract
- Background: Antioxidants in medical devices, added to protect polymers or adhesives, may also cause contact dermatitis in some individuals. Objectives: To present data on sensitization to 4,4′-thiobis(2-tert-butyl-5-methylphenol), an antioxidant detected in some types of medical devices, for six patients that experienced eczematous reactions to different medical devices. Methods: Patch testing with 4,4′-thiobis(2-tert-butyl-5-methylphenol), 1% pet was performed. Gas chromatography-mass spectrometry (GC-MS) was used for identification of 4,4′-thiobis(2-tert-butyl-5-methylphenol) in different medical device products. Results: Six patients with contact allergy to 4,4′-thiobis(2-tert-butyl-5-methylphenol) also had relevant contact allergic reactions to medical devices containing the antioxidant. The presence of the antioxidant in products was detected using GC-MS analysis. Conclusions: The antioxidant 4,4′-thiobis(2-tert-butyl-5-methylphenol) may cause allergic contact dermatitis after exposure to different medical devices.
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| 2. |
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| 3. |
- Bergman, Susanna L., et al.
(författare)
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In-situ studies of oxidation/reduction of copper in Cu-CHA SCR catalysts: Comparison of fresh and SO2-poisoned catalysts
- 2020
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Ingår i: Applied Catalysis B: Environmental. - : Elsevier BV. - 0926-3373 .- 1873-3883. ; 269
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Tidskriftsartikel (refereegranskat)abstract
- SO2-poisoning results in deactivation of Cu-CHA SCR under standard SCR conditions; however regeneration at 700 °C completely restores the SCR performance. To understand the nature of these effects, Cu-species in the fresh and poisoned catalysts were characterized by in-situ temperature-dependent time-resolved Cu K-edge X-ray absorption spectroscopy using the multivariate curve resolution alternating least squares (MCR-ALS) approach and continuous Cauchy wavelet transforms. The extracted chemically-meaningful reference spectra of Cu-species were analyzed by DFT-assisted XANES calculations. Cu-bisulfates were found as the most energetically favorable poisoned Cu-species. The response of Cu-species to a reducing environment differs in the fresh and SO2-poisoned catalysts. Differences in reducibility are related to the formation of quasi-linear Cu-complexes in the SO2-poisoned catalyst formed during heating in H2/He. Heating in H2/He leads to partial desulfurization of the poisoned catalyst. Cooling in H2/He after heating results in more facile formation of Cu-metal clusters in fresh catalyst than in SO2-poisoned.
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| 4. |
- Blake, Jolie, 1986, et al.
(författare)
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Scalable Reflective Plasmonic Structural Colors from Nanoparticles and Cavity Resonances – the Cyan-Magenta-Yellow Approach
- 2022
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Ingår i: Advanced Optical Materials. - : Wiley. - 2195-1071 .- 2162-7568. ; 10:13
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Tidskriftsartikel (refereegranskat)abstract
- Plasmonic metasurfaces for color generation are emerging as important components for next generation display devices. Fabricating bright plasmonic colors economically and via easily scalable methods, however, remains difficult. Here, the authors demonstrate an efficient and scalable strategy based on colloidal lithography to fabricate silver-based reflective metal–insulator–nanodisk plasmonic cavities that provide a cyan-magenta-yellow (CMY) color palette with high relative luminance. With the same basic structure, they exploit different mechanisms to efficiently produce a complete subtractive color palette. Finite-difference time-domain simulations reveal that these mechanisms include gap surface plasmon modes for thin insulators and hybridized modes between disk plasmons and Fabry–Pérot modes for thicker systems. To produce yellow hues, they take advantage of higher-energy gap surface plasmon modes to allow resonance dips in the blue spectral region for comparably large nanodisks, thereby circumventing difficult fabrication of nanodisks less than 80 nm. It is anticipated that incorporation of these strategies can reduce fabrication constraints, produce bright saturated colors, and expedite large-scale production.
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| 5. |
- Bruze, Magnus, et al.
(författare)
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Increased rates of fragrance allergy in fibromyalgia individuals tested with the Swedish baseline patch test series
- 2023
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Ingår i: Journal of the European Academy of Dermatology and Venereology. - : Wiley. - 0926-9959 .- 1468-3083. ; 37:1, s. 104-113
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Tidskriftsartikel (refereegranskat)abstract
- Background: Contact allergy can manifest in a variety of ways clinically. Systemic contact allergy may occasionally present with pain in muscles and joints. Fibromyalgia is a chronic rheumatic disease characterized by pain and with virtually unknown aetiology. Objectives: The aim of this study was to investigate the contact allergy rates to the sensitizers in a baseline series and compare with corresponding rates in dermatitis patients and the general population. Methods: Patch testing with the Swedish baseline series was performed in 120 individuals with fibromyalgia. Fisher's exact test was used for pair-wise comparisons of contact allergy rates between the fibromyalgia group and two control groups, dermatitis patients and individuals in the general population. Results: Contact allergy was significantly more common in the fibromyalgia group compared to the general population concerning nickel and the fragrance markers Myroxolon pereirae and fragrance mix I. There were fewer allergic reactions to preservatives in the fibromyalgia group compared with the dermatitis group. Conclusions: Myroxolon pereirae and fragrance mix I represent besides fragrance allergy also allergy to flavouring substances which indicate that oral exposure to flavouring substances and hygiene products might be important for sensitization and possibly elicitation of systemic contact allergy symptoms in fibromyalgia individuals.
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| 6. |
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| 7. |
- Comstedt, Lisbeth Rosholm, et al.
(författare)
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Effects of aluminium chloride added to common patch test substances
- 2023
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Ingår i: Contact Dermatitis. - : Wiley. - 0105-1873 .- 1600-0536. ; 88:6, s. 456-462
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Tidskriftsartikel (refereegranskat)abstract
- Background: A modulating effect of aluminium regarding type IV reactions might exist but has not been further investigated. Objectives: The aim of this study was to investigate the effect on patch test reactions when adding aluminium chloride hexahydrate (Al-Cl) to common test preparations. Materials and methods: Al-Cl in different concentrations was added to nickel sulphate 15.0% aqua (Ni), methylisothiazolinone 0.2% aqua (MI) and fragrance mix I 10.0% aqua/ethanol (FM I). The Ni preparations were tested in 120 consecutive patients. MI and FM I were tested in participants known to have contact allergy to the respective allergen. McNemar's test was used to decide which Ni preparation had the highest sensitivity. Wilcoxon signed-rank test was used to calculate pairwise comparison in summarized test score for the preparations with MI and FM I. Results: Adding Al-Cl 20.0%/30.0% to Ni identified twice as many patients with contact allergy to nickel compared to Ni without Al-Cl. Adding Al-Cl 20.0%/10.0% to MI, decreased the patch test reactivity compared to MI without Al-Cl. No differences in patch reactivity were noticed when adding Al-Cl to FM I. Conclusion: Al-Cl 20.0% or 30.0% seems to enhance the patch test reactivity to Ni 15.0% aqua.
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| 8. |
- Dahlin, Jakob, et al.
(författare)
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Chemical Methods for Detection of Allergens and Skin Exposure
- 2020
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Ingår i: Contact Dermatitis : Sixth Edition - Sixth Edition. - Cham : Springer International Publishing. - 9783030363352 - 9783030363345 ; , s. 631-652
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Bokkapitel (refereegranskat)abstract
- Many allergens are widely used in both consumer and occupational products. In many cases, it is difficult to know all the ingredients of a product since most products are not sufficiently labelled. To diagnose and prevent allergic contact dermatitis, the demonstration of allergens in the products from the patient’s environment is important. Chemical analysis of a product can make it possible to demonstrate the presence or absence of known allergens. Simple spot tests or documented analytical methods such as thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC), gas chromatography (GC), atomic absorption spectrophotometry (AAS), and inductively coupled plasma-mass spectrometry (ICP-MS) can be used. Moreover, with chemical methods, the purity of a substance can be checked and new allergens can be isolated and identified. Advanced methods such as mass spectrometry (MS), nuclear magnetic resonance spectroscopy (NMR), and infrared spectrophotometry (IR) are often required to identify isolated allergens.
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| 9. |
- Dahlin, Lars B., et al.
(författare)
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Improved metabolic control using glucose monitoring systems leads to improvement in vibration perception thresholds in type 1 diabetes patients
- 2020
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Ingår i: Acta Diabetologica. - : Springer Science and Business Media LLC. - 0940-5429 .- 1432-5233. ; 57:4, s. 433-438
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Tidskriftsartikel (refereegranskat)abstract
- Aims: Few studies have examined how improved metabolic control might influence vibration perception thresholds (VPTs). The aim of this study was to evaluate if improved HbA1c can influence vibration thresholds in adults with type 1 diabetes (T1DM). Methods: VPTs were investigated at six frequencies (4–125 Hz) using VibroSense Meter in the sole of the foot at two occasions in 159 T1DM patients, at the heads of the first and fifth metatarsal bones, i.e. MTH1 and MTH5, respectively. The participants were divided into three groups: group A: HbA1c improved by more than 1 mmol/mol (n = 95), group B: HbA1c deteriorated by more than 1 mmol/mol (n = 48) and group C: HbA1c unchanged (± 1 mmol/mol) (n = 16) compared to baseline. Results: In group A, the mean z-score, reflecting the combined effect of all VPTs, improved being lower at the follow-up than at the baseline [0.2 (− 0.3 to 1.2) vs. −0.1 (− 0.7 to 0.8), p = 0.00002]. VPTs improved at 4 and 64 Hz at both MTH1 (metatarsal head 1) and MTH5. The VPTs at 125 Hz frequency improved at MTH5, but not at MTH1. No significant differences were seen in group B or group C. Conclusions: Lower HbA1c and lower VPTs in T1DM patients were associated with improved VPT, suggesting a reversible effect on nerve function by improved metabolic control.
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| 10. |
- Dahlin, Sandra, et al.
(författare)
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Effect of biofuel- and lube oil-originated sulfur and phosphorus on the performance of Cu-SSZ-13 and V2O5-WO3/TiO2 SCR catalysts
- 2021
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Ingår i: Catalysis Today. - : Elsevier B.V.. - 0920-5861 .- 1873-4308. ; 360, s. 326-339
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Tidskriftsartikel (refereegranskat)abstract
- Two different SCR catalysts, V2O5-WO3/TiO2 and Cu-SSZ-13, were exposed to biodiesel exhausts generated by a diesel burner. The effect of phosphorus and sulfur on the SCR performance of these catalysts was investigated by doping the fuel with P-, S-, or P + S-containing compounds. Elemental analyses showed that both catalysts captured phosphorus while only Cu-SSZ-13 captured sulfur. High molar P/V ratios, up to almost 3, were observed for V2O5-WO3/TiO2, while the highest P/Cu ratios observed were slightly above 1 for the Cu-SSZ-13 catalyst. Although the V2O5-WO3/TiO2 catalyst captured more P than did the Cu-SSZ-13 catalyst, a higher degree of deactivation was observed for the latter, especially at low temperatures. For both catalysts, phosphorus exposure resulted in suppression of the SCR performance over the entire temperature range. Sulfur exposure, on the other hand, resulted in deactivation of the Cu-SSZ-13 catalyst mainly at temperatures below 300-350 °C. The use of an oxidation catalyst upstream of the SCR catalyst during the exhaust-exposure protects the SCR catalyst from phosphorus poisoning by capturing phosphorus. The results in this work will improve the understanding of chemical deactivation of SCR catalysts and aid in developing durable aftertreatment systems.
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