| 1. |
- Karlberg, Maria, et al.
(författare)
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Mixed solutions of an associating polymer with a cleavable surfactant
- 2005
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Ingår i: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 21:21, s. 9756-9763
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Tidskriftsartikel (refereegranskat)abstract
- Mixtures of hydrophobically modified hydroxyethyl cellulose (HMHEC) and alkali-sensitive cleavable betaine ester surfactants have been studied by viscometry, H-1 NMR, absorbance measurements, and birefringence determinations. Before the hydrolysis, the surfactants behaved as conventional nondegradable surfactants in terms of the effect on the viscosity of increasing surfactant concentration. As the surfactants were hydrolyzed, systems with time-dependent viscosity were obtained. The viscosity either decreased monotonically or went through a maximum as a function of time, depending on the initial surfactant concentration. Different surfactant chain lengths gave rise to different viscosity profiles. The rate of hydrolysis, and thus the time-dependency of the surfactant concentration, could be controlled by changing the pH of the solution.
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| 2. |
- Karlsson, Richard, et al.
(författare)
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Phosphatidylinositol 3-kinase is essential for kit ligand-mediated survival, whereas interleukin-3 and flt3 ligand induce expression of antiapoptotic Bcl-2 family genes
- 2003
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Ingår i: Journal of Leukocyte Biology. - : Oxford University Press (OUP). - 1938-3673 .- 0741-5400. ; 74:5, s. 923-931
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Tidskriftsartikel (refereegranskat)abstract
- Cytokines such as interleukin 3 (IL-3), kit ligand (KL), and flt3 ligand (FL) promote survival of hematopoietic stem cells and myeloid progenitor cells. In many cell types, members of the Bcl-2 gene family are major regulators of survival, but the mediating mechanisms are not fully understood. Using two myeloid progenitor cell lines, FDCP-mix and FDC-P1, as well as primary mouse bone marrow progenitors, we demonstrate that KL-mediated survival is dependent on the activation of phosphatidylinositol-3 (PI-3) kinase. The inhibitor LY294002 was able to completely abolish survival mediated by KL, whereas IL-3 and FL were only partially affected. Although all three cytokines induced phosphorylation of protein kinase B (PKB), only KL required PI-3 kinase activity to elicit survival in hematopoietic progenitors. In contrast, pretreatment of cells with inhibitors to the MAP kinase pathway did not affect the survival. We next established if IL-3 and FL activated antiapoptotic Bcl-2 and the related genes Bcl-X-L and Mcl-1. By RNA protection assay and Western blot analysis, we show that all three genes are induced by IL-3, whereas FL induces Bcl-2 and to some extent Bcl-XL. Importantly, KL could not sustain their expression. Moreover, use of inhibitors implied that IL-3 was mainly exerting its effect on Bcl-2 at the level of transcription. The addition of LY294002 did not affect the expression of Bcl-2 and Bcl-XL, and thus, we conclude that expression of antiapoptotic Bcl-2 family member genes is not dependent on PI-3 kinase activity. Our results indicate that cytokines exert distinct survival effects and that FL and IL-3 are capable of sustaining progenitor survival by upregulating the expression of Bcl-2 and related genes.
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| 3. |
- Andersdotter, Amelia, et al.
(författare)
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Godtyckligt regelverk hotar friheten på nätet
- 2013
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Ingår i: Dagens Nyheter. - 1101-2447. ; :2013-09-03
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Reglerna som möjliggör stängning av hemsidor på internet präglas av godtycke och otydlighet. Men det behöver inte vara särskilt svårt att skapa ett nytt och rättssäkert regelverk. Här har Sveriges EU-kommissionär Cecilia Malmström en viktig roll. Frågan är om hon tar sitt ansvar, skriver politiker och nätdebattörer.
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| 4. |
- Andersdotter, Amelia, et al.
(författare)
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Utfästelser räcker inte
- 2013
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Ingår i: Dagens nyheter (DN debatt). - 1101-2447.
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Det är nedslående att Cecilia Malmström givit upp kampen när det gäller fri- och rättigheter på nätet, skriver politiker och nätdebattörer. Den rättssäkerhet vi efterfrågar är en sådan som skyddar yttrandefriheten.
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| 5. |
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| 6. |
- Björkman, Max Bekken, et al.
(författare)
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Förstudie om resurskartläggning i företag : Att förstå och förändra för en ökad fysisk resurseffektivitet
- 2023
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Denna förstudie har syftat till att undersöka potentialen med fysisk resurskartläggning (RKL) inom företag. RKL kan dels höja den interna kunskapen om företagets resursanvändning, dels stödja extern kommunikation av företagets materialeffektivitet, samt fungera som ett underlag för policymakers som vill utreda styrmedel kopplade till resursanvändning.Initiativet till förstudien är delvis sprungen ur tanken att delar av det som idag görs inom energikartläggning (EKL) också skulle kunna appliceras på kartläggning av fysiska resursströmmar. I förstudien har därför EKL summerats översiktligt tillsammans med tidigare utvärderingar av EKL. Rapporten lyfter även fram viktiga lärdomar från EKL som kan användas i resurskartläggningssammahang.En viktig del av förstudien har bestått i att utforska vad ett koncept som RKL kan inkludera för att uppnå ökad resurseffektivitet. Begreppet RKL kan delas in i två huvudsakliga delar: Förstå och Förändra. Generellt handlar det om att först kartlägga fysiska resursflöden, och därefter agera på resultaten för att nå konkret handling och förändring. Förstudien ger förslag på ett antal befintliga metoder som kan användas för inledande kartläggning, exempelvis materialflödesanalys (MFA) och livscykelanalys (LCA). Kopplat till detta har förstudien undersökt verktyg och indikatorer för att mäta cirkularitet som företag kan använda för att skapa sig en bild av hur cirkulär företagets verksamhet, produkter och tjänster är.För att få en bättre förståelse för hur företag och aktörer i Sverige ser på en mer detaljerad kartläggning av fysiska resursflöden i sina verksamheter, genomfördes femton intervjuer och en enkätstudie. Den enskilt största nyttan som de intervjuade personerna uttryckte med RKL var att kunna visualisera och synliggöra fysiska resurser och hur de flödar genom verksamheten. Via kommande lagkrav inom EU i form av CSRD (Corporate Sustainability Reporting Directive) och ESRS (European Sustainability Reporting Standards) skruvas kraven på företags hållbarhetsredovisning upp. Detta nya regelverk kräver bland annat redovisning av in- och utflöden av fysiska resurser, samt att företagen ska kunna visa på mål, strategier och planer för hur resursflödena kan effektiviseras.De nya EU-kraven kommer troligen vara en av de starkaste drivkrafterna för företag att utföra RKL, i tillägg till externa krav från kunder och samarbetsparter. I rapporten har översiktliga processer skisserats som stöd för genomförande av RKL med hjälp av befintliga metoder och verktyg. RKL i företag är ett brett begrepp och därför kan RKL utföras på olika sätt beroende på syftet med kartläggningen och typ av företag.En slutsats från projektet är att det inte är nödvändigt eller lämpligt med en RKL-lagstiftning på samma sätt som dagens lagstiftning för EKL. Detta beror på att RKL innebär en större komplexitet än EKL och är svår att generalisera för alla företag. Den generella metodiken kan dock utformas på liknande sätt för RKL som för EKL, och stöden gällande nätverkande och lathundar skulle kunna erbjudas på liknande sätt för RKL som för EKL för att stötta företag i att uppfylla kommande krav.I det fortsatta arbetet med resurskartläggningar i företag är det viktigt att beakta: (1) Fokusera på att använda redan existerande metoder, verktyg och indikatorer för att mäta resurser och cirkularitet; (2) Samarbeta med organisationer som tillhandahåller och utvecklar metoder, verktyg och indikatorer för en ökad cirkularitet för att tillsammans med dem öka kunskapen och förståelsen hos företag; (3) Utveckla den skisserade RKLprocessen, så att den bättre kan visa vilka typer av metoder och indikatorer som passar särskilt bra för olika syften; (4) Testa och utveckla processerna och guiderna tillsammans med ett antal pilotföretag; (5) Integrera RKL-processen och guiden med pågående utveckling av standarder för rapportering inom EU och ISO-samarbetet.
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| 7. |
- Egermayer, Monica, et al.
(författare)
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Gels of hydrophobically modified ethyl (hydroxyethyl) cellulose cross-linked by amylose: Effects of hydrophobe architecture
- 2004
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Ingår i: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 20:6, s. 2208-2214
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Tidskriftsartikel (refereegranskat)abstract
- Previous work has shown that amylose (AM) can cross-link hydrophobically modified polymers by inclusion complexation, whereby thermoreversible cold-setting gels are formed. Here we investigate the complexation of AM with different samples of hydrophobically modified ethyl(hydroxyethyl) cellulose (HMEHEC), distinguished by differences in the architecture of the hydrophobes (the hydrophobic side chains). All hydrophobes, except one, were based on linear alkyl chains, but with varying chain lengths (C-12-C-14). In addition, some samples contained short hydrophilic "spacers", consisting of 2-5 ethylene oxide units, between the alkyl chains and the EHEC backbone. Gels of varying strength were obtained for the different AM/HMEHEC samples. The alkyl chain length seemed to be the major factor affecting the gel strength, with longer alkyl chains giving stronger gels. For similar alkyl chain lengths, stronger gels were obtained when a spacer was present. Addition of AM caused a small increase of the cloud points of HMEHECs with C-14 hydrophobes in water. Time-dependent effects and effects of the sample preparation procedure were also investigated. The reversibility of the gelation with respect to shear was confirmed. A gel destroyed by added surfactant was shown to reform on removal of the surfactant by dialysis.
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| 8. |
- Fourie, Anika, et al.
(författare)
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Exploring the learning needs of clinicians in Belgium and Sweden regarding prone positioning and skin damage prevention : A qualitative study
- 2023
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Ingår i: Nurse Education Today. - : Elsevier. - 0260-6917 .- 1532-2793. ; 128
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: During the coronavirus pandemic (COVID -19), the use of prone positioning in critically ill patients with acute respiratory distress syndrome (ARDS) increased substantially. As a result, clinicians had to (re)learn how to treat the patient in the prone position while preventing adverse events such as pressure ulcers, skin tears and moisture-associated skin damage.Aim: The purpose of the study was to determine participants' learning needs related to patients in the prone position and the prevention of skin damage, such as pressure ulcers, and what they perceived as a positive or negative learning experience.Design: This study used a qualitative methodological framework and employed an exploratory design.Participants: A purposive sample of clinicians (n = 20) with direct or indirect work experience with prone ventilated patients was recruited in Belgium and Sweden.Methods: Individual semi-structured interviews were conducted in Belgium and Sweden between February and August 2022. Data were analysed thematically using an inductive approach. The COREQ guideline was utilised to comprehensively report on the study.Findings: Two themes were identified: 'Adapting to a crisis' and 'How to learn', with the latter having two subthemes: 'balancing theory and practice' and 'co-creating knowledge'. Unexpected circumstances necessitated a personal adaption, a change in learning methods and a pragmatic adaptation of protocols, equipment and working procedures. Participants recognised a multifaceted educational approach which would contribute to a positive learning experience regarding prone positioning and skin damage prevention. The importance of poising theoretical teaching with practical hands-on training was highlighted with an emphasis on interaction, discussion, and networking between peers. Conclusions: The study findings highlight learning approaches which may help inform the development of befitting educational resources for clinicians. Prone therapy for ARDS patients is not limited to the pandemic. Therefore, educational efforts should continue to ensure patient safety in this important area.
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| 9. |
- Galanti, Maria Rosaria, et al.
(författare)
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School environment and mental health in early adolescence - a longitudinal study in Sweden (KUPOL)
- 2016
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Ingår i: BMC Psychiatry. - : Springer Science and Business Media LLC. - 1471-244X. ; 16
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Tidskriftsartikel (refereegranskat)abstract
- Background: Longitudinal studies indicate strong associations between school proficiency and indicators of mental health throughout adulthood, but the mechanisms of such associations are not fully elucidated. The Kupol study is a prospective cohort study in Sweden set up in order to: (i) describe the association of school pedagogic and social environment and its specific dimensions with the risk of mental ill-health and psychiatric disorders in adolescence; (ii) evaluate the direct effects of school pedagogic and social environment on mental health and the effects mediated by the individual's academic achievements; and (iii) assess if school pedagogic and social environment are associated with mental ill-health through epigenetic mechanisms, in particular those involving genes regulating the response to stress.Methods: The Kupol cohort at baseline consists of 3959 children attending the 7th grade of compulsory school (13-14 years old) in 8 regions of central Sweden in the school years 2013-2014 or 2014-2015. Three follow-up surveys in subsequent years are planned. Teachers' and students' perceptions of the culture, climate and ethos of their schools, and students' mental ill-health are assessed at the whole school level by annual questionnaire surveys. In order to conduct epigenetic analyses saliva specimens are collected from a nested sample of students at inception and two years later. Further, class-, family-and child-level information is collected at baseline and during each year of follow-up. Self-reported information is being complemented with register data via record-linkages to national and regional health and administrative registers.Discussion: The topic being investigated is new, and the sample constitutes the largest adolescent cohort in Sweden involved in an ad hoc study. Epigenetic analyses centered on environmental cues to stress response are a thoroughly new approach. Finally a notable feature is the multi-informant and multi-method data collection, with surveys at the school, class, family, and student level. Collaboration and data access: interested investigators should contact the coordinating centre. Additional information is available on the study's website, http://kupolstudien.se/.
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| 10. |
- Gorcenco, Sorina, et al.
(författare)
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Ataxia-pancytopenia syndrome with SAMD9L mutations
- 2017
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Ingår i: Neurology: Genetics. - 2376-7839. ; 3:5
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: We describe the neurologic, neuroradiologic, and ophthalmologic phenotype of 1 Swedish and 1 Finnish family with autosomal dominant ataxia-pancytopenia (ATXPC) syndrome and SAMD9L mutations.METHODS: Members of these families with germline SAMD9L c.2956C>T, p.Arg986Cys, or c.2672T>C, p.Ile891Thr mutations underwent structured interviews and neurologic and ophthalmologic examinations. Neuroimaging was performed, and medical records were reviewed. Previous publications on SAMD9L-ATXPC were reviewed.RESULTS: Twelve individuals in both families were affected clinically. All mutation carriers examined had balance impairment, although severity was very variable. All but 1 had nystagmus, and all but 1 had pyramidal tract signs. Neurologic features were generally present from childhood on and progressed slowly. Two adult patients, who experienced increasing clumsiness, glare, and difficulties with gaze fixation, had paracentral retinal dysfunction verified by multifocal electroretinography. Brain MRI showed early, marked cerebellar atrophy in most carriers and variable cerebral periventricular white matter T2 hyperintensities. Two children were treated with hematopoietic stem cell transplantation for hematologic malignancies, and the neurologic symptoms of one of these worsened after treatment. Three affected individuals had attention deficit hyperactivity disorder or cognitive problems. Retinal dysfunction was not previously reported in individuals with ATXPC.CONCLUSIONS: The neurologic phenotype of this syndrome is defined by balance or gait impairment, nystagmus, hyperreflexia in the lower limbs and, frequently, marked cerebellar atrophy. Paracentral retinal dysfunction may contribute to glare, reading problems, and clumsiness. Timely diagnosis of ATXPC is important to address the risk for severe hemorrhage, infection, and hematologic malignancies inherent in this syndrome; regular hematologic follow-up might be beneficial.
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| 11. |
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| 12. |
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| 13. |
- Grafström, Maria, 1978-, et al.
(författare)
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Mediatization of civil society organizations : (De)legitimation of the Swedish Red Cross
- 2015
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Ingår i: Journal of Civil Society. - : Informa UK Limited. - 1744-8689 .- 1744-8697. ; 11:3, s. 227-241
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Tidskriftsartikel (refereegranskat)abstract
- The article explores how media representations influence ideas about legitimate behaviour within a civil society organization (CSO). We develop understanding of the mediatization of CSOs, and in particular of how media coverage influences internal practices and decision-making. The analysis is based on a case study of the Swedish Red Cross and illustrates how (negative) media exposure influences the conditions for, and behaviour of, a CSO. The findings demonstrate that media constructed a legitimacy crisis and that the organization over time adjusted to the media story to maintain its legitimacy. The findings also suggest that professional communicators play significant roles in carrying and reinforcing ideas within CSOs about the importance of controlling media attention.
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| 14. |
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| 15. |
- Groenheit, Ramona, et al.
(författare)
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High Prevalence of SARS-CoV-2 Omicron Infection Despite High Seroprevalence, Sweden, 2022
- 2023
-
Ingår i: Emerging Infectious Diseases. - : CENTERS DISEASE CONTROL & PREVENTION. - 1080-6040 .- 1080-6059. ; 29:6
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Tidskriftsartikel (refereegranskat)abstract
- We performed 2 surveys during 2022 to estimate point prevalences of SARS-CoV-2 infection compared with overall viral seroprevalence in Sweden. Point prevalence was 1.4% in March and 1.5% in September. Estimated seroprevalence was >80%, including among unvaccinated children. Continued SARS-CoV-2 surveillance is necessary for detecting emerging, possibly more pathogenic variants.
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| 16. |
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| 17. |
- Hagvall, Lina, 1978, et al.
(författare)
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Lavender oil lacks natural protection against autoxidation, forming strong contact allergens on air exposure
- 2008
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Ingår i: Contact Dermatitis. - : Wiley. - 0105-1873 .- 1600-0536. ; 59:3, s. 143-150
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Tidskriftsartikel (refereegranskat)abstract
- Lavender oil is an essential oil frequently used as a fragrance ingredient and in traditional herbal medicine. We have previously studied the effect of air oxidation on the skin sensitizing potency of the monoterpenes linalyl acetate, linalool and β-caryophyllene, the main constituents of lavender oil.
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| 18. |
- Hamalainen, Markku D., et al.
(författare)
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Real-time Monitoring Using a Breathalyzer-Based eHealth System Can Identify Lapse/Relapse Patterns in Alcohol Use Disorder Patients
- 2018
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Ingår i: Alcohol and Alcoholism. - : OXFORD UNIV PRESS. - 0735-0414 .- 1464-3502. ; 53:4, s. 368-375
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Tidskriftsartikel (refereegranskat)abstract
- Aim: We introduce a new remote real-time breathalyzer-based method for monitoring and early identification of lapse/relapse patterns for alcohol use disorder (AUD) patients using a composite measure of sobriety, the Addiction Monitoring Index (AMI). Methods: We constructed AMI from (a) obtained test results and (b) the pattern of ignored tests using data from the first 30 patients starting in the treatment arms of two on-going clinical trials. The patients performed 2-4 scheduled breath alcohol content (BrAC)-tests per day presented as blood alcohol content (BAC) data. In total, 10,973 tests were scheduled, 7743 were performed and 3230 were ignored during 3982 patient days. Results: AMI-time profiles could be used to monitor the daily trends of alcohol consumption and detect early signs of lapse and relapses. The pattern of ignored tests correlates with the onset of drinking. AMI correlated with phosphatidyl ethanol (n = 61, F-ratio = 34.6, P < 0.0001, R = -0.61). The recognition of secret drinking could further be improved using a low alcohol detection threshold (BrAC = 0.025 mg/l, BAC(Swe) = 0.05% or US = 0.0053 g/dl), in addition to the legal Swedish traffic limit (BrAC = 0.1 mg/l, BAC(Swe) = 0.2% or US = 0.021 g/dl). Nine out of 10 patients who dropped out from the study showed early risk signs as reflected in the level and pattern in AMI before the actual dropout. Conclusions: AMI-time profiles from an eHealth system are useful for monitoring the recovery process and for early identification of lapse/relapse patterns. High-resolution monitoring of sobriety enables new measurement-based treatment methods for proactive personalized long-term relapse prevention and treatment of AUD patients. Clinical Trial Registration: The data used for construction of AMI was from two clinical trials approved by the Regional Ethics Committee of Uppsala, Sweden and performed in accordance with the Declaration of Helsinki. Written informed consent was obtained from all participating subjects. The study was registered at ClinicalTrials.gov (NCT03195894).
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| 19. |
- Hammarin, Anna Lena, et al.
(författare)
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Ny subtyp av molluscipoxvirus påvisad : Modern teknik identifierar nya och ovanliga patogener snabbare
- 2016
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Ingår i: Läkartidningen. - 0023-7205. ; 113:48, s. 1-4
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Molluscum contagiosum is a viral infection of the epidermis characterized by skin-colored papules or nodules frequently with a central depression. Atypical variants may occur, primarily in immunosuppressed individuals. We here report a case of »giant Molluscum contagiosum« in an immunocompetent child. The patient was presented with a fairly smooth nodule of 2 cm in diameter on the ring finger. Molluscipoxvirus-like virus particles were detected by electron microscopy from the nodule, but since the clinical picture was not compatible with MC, next generation sequencing was performed in order to verify the diagnosis. Of the total number of obtained sequences, 25% belonged to molluscipoxvirus (MCV) and de novo assembly revealed three contigs corresponding to 95% of the MCV genome. The assembled genome was compared to previously published sequences of the »major envelope protein« used for genotyping of MCV genus. Several unique single nucleotide polymorphisms were identified, which led us to classify this virus as a new subtype of MCV.
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| 20. |
- Hultin, Hanna, et al.
(författare)
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Pedagogical and Social School Climate : Psychometric Evaluation and Validation of the Student Edition of PESOC
- 2019
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Ingår i: Scandinavian Journal of Educational Research. - : Routledge. - 0031-3831 .- 1470-1170. ; 63:4, s. 534-550
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Tidskriftsartikel (refereegranskat)abstract
- Previous studies indicate that school climate is important for student health and academic achievement. This study concerns the validity and reliability of the student edition a Swedish instrument for measuring pedagogical and social school climate (PESOC). Data were collected from 5,745 students at 97 Swedish secondary schools. Multilevel confirmatory factor analyses were conducted, and multilevel composite reliability estimates, as well as correlations with school-level achievement indicators, were calculated. The results supported an 8-factor structure at the student level and 1 general factor at the school level. Factor loadings and composite reliability estimates were acceptable at both levels. The school-level factor was moderately and positively correlated with school-level academic achievement. The student PESOC is a promising instrument for studying school climate.
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| 21. |
- Karlberg, Maria, et al.
(författare)
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Gels of hydrophobically modified hydroxyethyl cellulose cross-linked by amylose. Competition with cyclodextrin
- 2006
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Ingår i: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 22:5, s. 2241-2248
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Tidskriftsartikel (refereegranskat)abstract
- Previous work has shown that amylose (AM) can cross-link hydrophobically modified polymers by inclusion complexation, whereby thermoreversible cold-setting gels are formed. In this work, the competition between AM and cyclodextrin (CD) for the formation of inclusion complexes with hydrophobically modified hydroxyethyl cellulose (HMHEC) is investigated. A detailed study of viscosity, NMR self-diffusion, and chemical shifts of the two-component mixture, CD and HMHEC, was performed. The results imply that 2:1 (CD:polymer hydrophobe) complexes may be formed. The three-component mixtures, HMHEC/AM/CD, were investigated by rheology, NMR self-diffusion, and intensities of the NMR resonance peaks. The CD molecules competed efficiently with the AM molecules, as seen by a decreased storage modulus, an increased self-diffusion of AM and HMHEC, and increased NMR intensities of the HMHEC hydrophobes, as the concentration of CD increased in the solution. A high concentration of CD is needed in the mixtures to inhibit all interactions between HMHEC and AM, and it was shown that there still is an effect of AM at excess CD concentration in the mixtures.
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| 22. |
- Karlberg, Maria, et al.
(författare)
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Hydrophobically modified ethyl(hydroxyethyl)cellulose as stabilizer and emulsifying agent in macroemulsions
- 2005
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Ingår i: Colloids and Surfaces A: Physicochemical and Engineering Aspects. - : Elsevier BV. - 0927-7757. ; 262:1-3, s. 158-167
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Tidskriftsartikel (refereegranskat)abstract
- Stability, droplet diameter and viscosity of o/w macroemulsions of olive oil stabilized with lecithin from soybean and different types of polymers have been investigated. The stabilizing polymers were non-ionic cellulose ethers, both with and without hydrophobic groups grafted onto the polymer backbone. Emulsions without polymers showed essentially no stability against creaming. Unmodified polymers provided limited stability, while hydrophobically modified versions of the polymers improved the stability dramatically. The viscosity of emulsions stabilized by hydrophobically modified polymers was significantly increased compared with aqueous solutions of the polymers alone, suggesting network formation including both polymers and emulsion droplets. It was also found that dilution had virtually no effect on the droplet diameters of emulsions stabilized with hydrophobically modified cellulose ethers and that coalescence was effectively opposed. (c) 2005 Elsevier B.V. All rights reserved.
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| 23. |
- Karlberg, Maria, et al.
(författare)
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Impact of temperature and species interaction on filamentous cyanobacteria may be more important than salinity and increased pCO(2) levels
- 2013
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Ingår i: Marine Biology. - : Springer Science and Business Media LLC. - 0025-3162 .- 1432-1793. ; 160:8, s. 2063-2072
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Tidskriftsartikel (refereegranskat)abstract
- A future business-as-usual scenario (A1FI) was tested on two bloom-forming cyanobacteria of the Baltic Proper, Nodularia spumigena and Aphanizomenon sp., growing separately and together. The projected scenario was tested in two laboratory experiments where (a) interactive effects of increased temperature and decreased salinity and (b) interactive effects of increased temperature and elevated levels of pCO(2) were tested. Increased temperature, from 12 to 16 A degrees C, had a positive effect on the biovolume and photosynthetic activity (F (v)/F (m)) of both species. Compared when growing separately, the biovolume of each species was lower when grown together. Decreased salinity, from 7 to 4, and elevated levels of pCO(2), from 380 to 960 ppm, had no effect on the biovolume, but on F (v)/F (m) of N. spumigena with higher F (v)/F (m) in salinity 7. Our results suggest that the projected A1FI scenario might be beneficial for the two species dominating the extensive summer blooms in the Baltic Proper. However, our results further stress the importance of studying interactions between species.
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| 24. |
- Karlberg, Maria, et al.
(författare)
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Mixed solutions of hydrophobically modified graft and block copolymers
- 2004
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Ingår i: Colloids and Surfaces A: Physicochemical and Engineering Aspects. - : Elsevier BV. - 0927-7757. ; 236:1-3, s. 159-164
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Tidskriftsartikel (refereegranskat)abstract
- Phase separation temperatures and viscosities of dilute and semidilute aqueous mixtures of hydrophobically modified graft and block copolymers have been studied. The graft copolymer was hydrophobically modified ethyl(hydroxyethyl)cellulose (HM-EHEC), and the block copolymers were hydrophobically modified poly(ethylene glycol) (HM-PEG) with diblock (DB) or triblock (TB) structures, i.e., modified at one or both ends, respectively. For comparison, viscosity measurements were made also on mixtures of TB with HM-HEC, and on systems where one of the polymers was unmodified (i.e. HM-EHEC/PEG or TB/EHEC). All results indicate mixed hydrophobic associations between graft and block copolymers. Moderate viscosity enhancements were found on addition of HM-PEG to HM-EHEC, and the effects were larger for TB than for DB. The viscosity changes were quite sensitive to the concentration of HM-EHEC. (C) 2004 Elsevier B.V. All rights reserved.
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| 25. |
- Karlberg, Maria, et al.
(författare)
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Solubility of amylose/ionic surfactant complexes in dilute aqueous solutions: Dependence on surfactant concentration
- 2007
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Ingår i: Carbohydrate Polymers. - : Elsevier BV. - 0144-8617. ; 70:3, s. 350-354
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Tidskriftsartikel (refereegranskat)abstract
- The solubility in dilute aqueous solutions of amylose complexed with ionic surfactants has been investigated by turbidity measurements. The turbidity depended on both the amylose and the surfactant concentrations. Low and high surfactant concentrations resulted in macroscopic phase separation, while mixtures at intermediate surfactant concentrations remained monophasic for at least one month. The solubility of the complexes was sensitive to the addition of salt as well as to the surfactant charge and hydrophobic chain length. These results are interpreted in terms of an electrostatic stabilisation of soluble complexes. Complexes with a non-ionic surfactant were not soluble at any mixing ratio. (c) 2007 Elsevier Ltd. All rights reserved.
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| 26. |
- Karlberg, Maria
(författare)
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Synergistic interactions involving amphiphilic polymers in solution
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The properties of hydrophobically modified cellulose derivatives in aqueous mixtures with various other molecules have been investigated. Mixtures of a hydrophobically modified polymer and alkali-sensitive, degradable surfactants gave rise to time-dependent viscosities. With time, the viscosity decreased continuously or went through a maximum, depending on the initial surfactant concentration. The rate of change could be controlled by pH. The alcohol formed by degradation acted as a cosurfactant, and varying the hydrophobic chain length gave rise to different viscosity profiles. Phase separation temperatures and viscosities of aqueous mixtures of the hydrophobically modified cellulose derivatives and block copolymers have been investigated. The block copolymers were hydrophobically modified at one or both ends. The results were consistent with hydrophobic association between the cellulose derivatives and the block copolymers. Moderate viscosity enhancements were found on addition of the block copolymers to the cellulose derivatives and the effects were larger with the block copolymer that was modified at both ends. Amylose can cross-link hydrophobically modified polymers by inclusion complexation, whereby strong, thixotropic, thermoreversible, cold-setting, gels are formed. The gel strength as a function of the architecture of the polymer hydrophobes has been investigated. The hydrophobes were based on linear alkyl chains and longer alkyl chains gave stronger gels. For similar alkyl chain lengths, stronger gels were obtained when a spacer consisting of ethylene oxide units was inserted between the alkyl chain and the polymer backbone. The competition between amylose and cyclodextrin for the formation of inclusion complexes with hydrophobically modified polymers has also been studied. The cyclodextrin molecules competed efficiently with the amylose molecules as seen by rheology, self-diffusion and NMR intensities of the polymer hydrophobes. A detailed study of the hydrophobically modified polymers and cyclodextrin has been performed where it was seen that 2:1 (cyclodextrin:polymer hydrophobe) complexes were formed. Stability, droplet diameter and viscosity of o/w macroemulsions stabilized with lecithin and different types of polymers have been examined. Emulsions without polymers showed essentially no stability against creaming. Unmodified polymers provided limited stability, while hydrophobically modified polymers improved the stability dramatically. The viscosity of emulsions stabilized by hydrophobically modified polymers was significantly increased compared with aqueous solutions of the polymers alone, suggesting network formation including both polymers and emulsion droplets.
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| 27. |
- Karlberg, Martin, 1969-, et al.
(författare)
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The Importance of School Pedagogical and Social Climate to Students’ Unauthorized Absenteeism – a Multilevel Study of 101 Swedish Schools
- 2022
-
Ingår i: Scandinavian Journal of Educational Research. - : Taylor & Francis Group. - 0031-3831 .- 1470-1170. ; 66:1, s. 88-104
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Tidskriftsartikel (refereegranskat)abstract
- While individual and family factors behind students’ school absenteeism are well-researched, fewer studies have addressed school climate factors. This study investigated the association between school climate in Swedish schools and students’ absenteeism. A multi-informant survey of school climate was conducted in 101 schools and analysed in relation to the history of absenteeism of 2770 students attending those schools in the 7th grade at inception, with follow-up until completion of the compulsory school (9th grade). Data on absenteeism was extracted from schools’ registers. Student (but not teacher) positive ratings of school climate were associated with lower absenteeism between the age of 13 and the age of 16. The associations between student rated school climate and absenteeism appeared stronger among students with highly educated parents.
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| 28. |
- Klemedtsson, Leif, 1953, et al.
(författare)
-
Bayesian calibration method used to elucidate carbon turnover in forest on drained organic soil
- 2008
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Ingår i: Biogeochemistry. - : Springer Science and Business Media LLC. - 0168-2563 .- 1573-515X. ; 89:1, s. 61-79
-
Tidskriftsartikel (refereegranskat)abstract
- Depending on the balance between sink and source processes for C, drained organic forest soil ecosystems can be in balance or act as net sinks or sources of CO2 to the atmosphere. In order to study the effect of groundwater level and soil temperature on C-flux, the CoupModel was calibrated (climate data, groundwater levels, soil CO2 flux, net ecosystem fluxes of CO2-exchange, sensible heat flux and latent heat flux, forest production etc.) for a drained forest in Sweden. Bayesian calibration techniques were used to elucidate how different parameters and variables were interlinked in C-circulation. The calibrated model reproduced abiotic and biotic variables reasonably well except for root respiration, which was largely underestimated. Bayesian calibration reduced the uncertainties in the model and highlighted the fact that calibrations should be performed with a high number of parameters instead of specific parameter values.
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| 29. |
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| 30. |
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| 31. |
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| 32. |
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| 33. |
- Madrigal, Irene, et al.
(författare)
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A novel splicing mutation in the IQSEC2 gene that modulates the phenotype severity in a family with intellectual disability.
- 2016
-
Ingår i: European Journal of Human Genetics. - : Springer Science and Business Media LLC. - 1018-4813 .- 1476-5438. ; 24:8, s. 1117-1123
-
Tidskriftsartikel (refereegranskat)abstract
- The IQSEC2 gene is located on chromosome Xp11.22 and encodes a guanine nucleotide exchange factor for the ADP-ribosylation factor family of small GTPases. This gene is known to have a significant role in cytoskeletal organization, dendritic spine morphology and synaptic organization. Variants in IQSEC2 cause moderate to severe intellectual disability in males and a variable phenotype in females because this gene escapes from X-chromosome inactivation. Here we report on the first splicing variant in IQSEC2 (g.88032_88033del; NG_021296.1) that co-segregates in a family diagnosed with an X-linked form of ID. In a percentage of the cells, the variant activates an intraexonic splice acceptor site that abolishes 26 amino acids from the highly conserved PH domain of IQSEC2 and creates a premature stop codon 36 amino acids later in exon 13. Interestingly, the percentage of aberrant splicing seems to correlate with the severity of the disease in each patient. The impact of this variant in the target tissue is unknown, but we can hypothesize that these differences may be related to the amount of abnormal IQSEC2 transcript. To our knowledge, we are reporting a novel mechanism of IQSEC2 involvement in ID. Variants that affect splicing are related to many genetic diseases and the understanding of their role in disease expands potential opportunities for gene therapy. Modulation of aberrant splicing transcripts can become a potent therapeutic approach for many of these diseases.
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| 34. |
- Madrigal, Irene, et al.
(författare)
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Efficient application of next-generation sequencing for the diagnosis of rare genetic syndromes
- 2014
-
Ingår i: Journal of Clinical Pathology. - : BMJ. - 0021-9746 .- 1472-4146. ; 67:12, s. 1099-1103
-
Tidskriftsartikel (refereegranskat)abstract
- Aims The causes of intellectual disability, which affects 1%-3% of the general population, are highly heterogeneous and the genetic defect remains unknown in around 40% of patients. The application of next-generation sequencing is changing the nature of biomedical diagnosis. This technology has quickly become the method of choice for searching for pathogenic mutations in rare uncharacterised genetic diseases. Methods Whole-exome sequencing was applied to a series of families affected with intellectual disability in order to identify variants underlying disease phenotypes. Results We present data of three families in which we identified the disease-causing mutations and which benefited from receiving a clinical diagnosis: Cornelia de Lange, Cohen syndrome and Dent-2 disease. The genetic heterogeneity and the variability in clinical presentation of these disorders could explain why these patients are difficult to diagnose. Conclusions The accessibility to next-generation sequencing allows clinicians to save much time and cost in identifying the aetiology of rare diseases. The presented cases are excellent examples that demonstrate the efficacy of next-generation sequencing in rare disease diagnosis.
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| 35. |
- Matura, Mihaly, 1964, et al.
(författare)
-
Not only oxidized R-(+)- but also S-(-)-limonene is a common cause of contact allergy in dermatitis patients in Europe.
- 2006
-
Ingår i: Contact dermatitis. - : Wiley. - 0105-1873 .- 1600-0536. ; 55:5, s. 274-9
-
Tidskriftsartikel (refereegranskat)abstract
- Limonene, one of the most often used fragrance terpenes in any kind of scented products, is prone to air-oxidation. The oxidation products formed have a considerable sensitizing potential. In previous patch test studies on consecutively tested dermatitis patients, oxidized R-limonene has been proven to be a good and frequent indicator of fragrance-related contact allergy. The current study extends these investigations to 6 European clinics of dermatology, where the oxidation mixture of both enantiomers of limonene (R and S) have been tested in 2411 dermatitis patients. Altogether, 63 out of 2411 patients tested (2.6%) reacted to 1 or both the oxidized limonene preparations. Only 2.3% reacted to the oxidized R-limonene and 2.0% to the oxidized S-limonene. In 57% of the cases, simultaneous reactions were observed to both oxidation mixtures. Concomitant reactions to the fragrance mix, colophonium, Myroxylon pereirae, and fragrance-related contact allergy were common in patients reacting to 1 or both the oxidized limonene enantiomers. Our study provides clinical evidence for the importance of oxidation products of limonene in contact allergy. It seems advisable to screen consecutive dermatitis patients with oxidized limonene 3% petrolatum, although this patch test material is not yet commercially available.
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| 36. |
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| 37. |
- Metzendorf, Christoph, 1977-
(författare)
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Mitochondrial Iron Metabolism : Study of mitoferrin in Drosophila melanogaster
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Iron has a dualistic character. On the one hand it is essential for the life of most organisms, on the other hand it is involved in the generation of reactive oxygen species that are implicated in diseases and aging. During evolution efficient mechanisms for uptake, handling and storage of iron in a safe way have developed to keep the balance between iron availability and minimizing the hazards. In eukaryotes, mitochondria are the central organelle for “metabolizing” iron and consequently play an important role in cellular iron homeostasis. Mitoferrins are mitochondrial carrier proteins, which are involved in iron transport into mitochondria. In vertebrates two mitoferrins exist, one (mitoferrin1) of which is essential for heme synthesis during erythropoiesis, while the function of the other (mitoferrin2) is not well defined. In the fruit fly we found only one mitoferrin gene (dmfrn), which codes most likely for a functional homologueof vertebrate mitoferrin2. In Drosophila cell culture, dmfrn overexpression resulted in an overestimation of cell sensed iron levels. The signal responsible for this, is most likely a yet unidentified compound of ISC synthesis. In the cell culture system we also showed that iron chelation blocks the progression of the cell cycle in a reversible and therefore most likely controlled way. Study of different dmfrn mutants indicates a role of dmfrn during spermatogenesis and development to adulthood. As dmfrn deletion mutants are not lethal, it is likely that other lower affinity iron transporters exist. A similar conclusion has been drawn by others from the study of yeast mitoferrin homologuemutants. Rim2p/Mrs12p has recently been implicated in mitochondrial iron transport, and might be an alternative metal carrier. We identified a putative homologuein the fruit fly and found a possible link between mutants in this gene and iron. Our results emphasize the importance of the mitochondrial iron metabolism in cellular iron homeostasis. We also show for the first time, a direct connection between the mitochondrial iron metabolism and spermatogenesis. Mutants characterized and developed by us will help to study these processes in further detail and reveal the underlying mechanisms.
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| 38. |
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| 39. |
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| 40. |
- Nyström, Fredrik H., et al.
(författare)
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Population-based reference values for IGF-I and IGF-binding protein-1 : Relations with metabolic and anthropometric variables
- 1997
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Ingår i: European Journal of Endocrinology. - : Oxford University Press (OUP). - 0804-4643 .- 1479-683X. ; 136:2, s. 165-172
-
Tidskriftsartikel (refereegranskat)abstract
- Population-based reference values for IGF-I and IGF-binding protein-1 (IGFBP-1) have been established. One hundred and one women and the same number of men, 20–70 years old, were randomly selected from the population registry in the community of Linköping. Participation rate was 67%. Venous blood was drawn in the fasting state. Serum IGF-I was measured by RIA after acid-ethanol extraction and IGFBP-1 was determined by ELISA. IGF-I levels did not differ between genders and the decline with age was similar in men and women (men: Y=366–3·28×age (years), r =−0·61, P<0·0001; women: Y=386–3·49×age, r =−0·57, P<0·0001, P=0·4 for difference in slope). There were negative correlations between IGF-I and plasma lipids and blood pressure in both genders, but none was independent of age. Serum angiotensin-converting enzyme activity correlated positively with IGF-I in men independently from age (r =0·21, P=0·01). The distribution of IGFBP-1 was positively skewed and it was higher in women than in men (5·9±4·8 μg/l and 4·0±3·3 μg/l respectively; Mann–Whitney, P=0·002). In men and in the women not taking oestrogen, IGFBP-1 correlated positively with age (Spearman rank correlation (Spearman): men: r=0·32, P=0·002; women: r=0·24, P=0·03). C-peptide correlated negatively (Spearman: men: r =−0·38, P=0·002; women: r =−0·49, P<0·000) and sex hormone binding globulin positively with IGFBP-1 (Spearman: men: r=0·50, P<0·0001; women: r =0·55, P<0·0001).
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| 41. |
- Olofsson, Malin, et al.
(författare)
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Limited response of a spring bloom community inoculated with filamentous cyanobacteria to elevated temperature and pCO2
- 2019
-
Ingår i: Botanica Marina. - : Walter de Gruyter GmbH. - 0006-8055 .- 1437-4323. ; 62:1
-
Tidskriftsartikel (refereegranskat)abstract
- Temperature and CO2 levels are projected to increase in the future, with consequences for carbon and nutrient cycling in brackish environments, such as the Baltic Sea. Moreover, filamentous cyanobacteria are predicted to be favored over other phytoplankton groups under these conditions. Under a 12-day outdoor experiment, we examined the effect on a natural phytoplankton spring bloom community of elevated temperature (from 1°C to 4°C) and elevated pCO2 (from 390 to 970 μatm). No effects of elevated pCO2 or temperature were observed on phytoplankton biovolumes, but a significantly higher photosystem II activity was observed at elevated temperature after 9 days. In addition, three species of diazotrophic filamentous cyanobacteria were inoculated to test their competitive capacity under spring bloom conditions. The toxic cyanobacterium Nodularia spumigena exhibited an average specific growth rate of 0.10 d−1 by the end of the experiment, indicating potential prevalence even during wintertime in the Baltic Sea. Generally, none of the inoculated cyanobacteria species were able to outcompete the natural phytoplankton species at temperatures ≤4°C. No direct effects were found on heterotrophic bacteria. This study demonstrates the highly efficient resistance towards short-term (12 days) changes in abiotic factors by the natural Baltic Sea spring bloom community.
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| 42. |
- Olofsson, Malin, et al.
(författare)
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Phytoplankton community composition and primary production in the tropical tidal ecosystem, Maputo Bay (the Indian Ocean)
- 2017
-
Ingår i: Journal of Sea Research. - : Elsevier BV. - 1385-1101 .- 1873-1414. ; 125, s. 18-25
-
Tidskriftsartikel (refereegranskat)abstract
- © 2017 Elsevier B.V.Maputo Bay is highly affected by large tidal changes and riverine freshwater input with a phytoplankton biomass peak during March each year. Microscopy analysis was used to describe how the phytoplankton community composition was affected by tidal changes, during four in situ incubation experiments. Using stable isotope tracers, new and total primary production, based on nitrate (15NO3−)- and carbon (13C–bicarbonate)-assimilation were estimated. The highest biovolume of phytoplankton (> 2 μm) and also the highest C– and NO3−-assimilation rates (nM h−1) were found at spring-high tide. The C:N (mol:mol) ratio of particulate organic matter (POM) varied between 6.0 and 8.2. The proportion of diatoms in the phytoplankton community was higher at spring-high tide as compared to neap-low tide, whereas dinoflagellates were found in a reverse pattern. New production ranged between 6.3% and 10.4% of total primary production and was thus within the range previously reported for tropical regions. The largest proportion of NO3−-based new production relative to total production was estimated during calm conditions and spring-high tide. Concordantly, a large fraction of the microplanktonic community covered their N-demand by other sources of N than NO3−.
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| 43. |
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| 44. |
- Petrelius Karlberg, Pernilla, et al.
(författare)
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The Creation of a Crisis of Confidence : A Study of the Mediatization of the Red Cross
- 2013
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Ingår i: Trust and Organizations. - New York : Palgrave Macmillan. - 9781349475377 - 9781137368812 ; , s. 127-146
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- These were some of the Swedish newspaper headlines on articles concerning the Swedish Red Cross and its crisis in the spring of 2010. Breathless headers followed hot on each other’s heels as the organization and its representatives were criticized in a sea of news articles, letters to editors, and editorials. In the media, the loss of confidence in the Red Cross, and especially in the chairman of its board, Bengt Westerberg, was discussed heatedly. Within the Red Cross itself, however, these reports were perceived as being unfair. The Red Cross believed that its organization was open, fair, and democratic. While the media maintained that the Red Cross was suffering from a crisis of confidence, the employees in the organization could neither understand how such a crisis could arise, nor why the media attention was so drawn out and persistent.
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| 45. |
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| 46. |
- Sköld, Maria, 1976, et al.
(författare)
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Autoxidation of linalyl acetate, the main component of lavender oil, creates potent contact allergens
- 2008
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Ingår i: Contact Dermatitis. - : Wiley. - 0105-1873. ; 58:1, s. 9-14
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Fragrances are among the most common causes of allergic contact dermatitis. We have in previous studies shown that linalool, present in lavender oil, autoxidizes on air exposure, forming allergenic oxidation products. Oxidized linalool was found to be a frequent cause of contact allergy in a patch test study on consecutive dermatitis patients. Linalyl acetate, the main component of lavender oil is commonly used as a fragrance chemical in scented products. Because of structural similarities, linalyl acetate should also be susceptible to oxidation on air exposure, forming similar oxidation products as linalool.
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| 47. |
- Sköld, Maria, 1976, et al.
(författare)
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Contact allergens formed on air exposure of linalool. Identification and quantification of primary and secondary oxidation products and the effect on skin sensitization.
- 2004
-
Ingår i: Chemical research in toxicology. - : American Chemical Society (ACS). - 0893-228X .- 1520-5010. ; 17:12, s. 1697-705
-
Tidskriftsartikel (refereegranskat)abstract
- Linalool (3,7-dimethyl-1,6-octadien-3-ol) is an important fragrance chemical, frequently used in scented products because of its fresh, flowery odor. Linalool is an unsaturated hydrocarbon and is therefore susceptible to oxidation in the presence of air. The primary oxidation products, that is, hydroperoxides, formed in the autoxidation process, are reactive compounds that can be suspected to act as sensitizers. In the present investigation, we studied the autoxidation of linalool with emphasis on the formation of hydroperoxides. The oxidation products were isolated using flash chromatography and preparative HPLC and were identified with NMR and GC/MS, using synthesized reference compounds. Two hydroperoxides and several different secondary oxidation products were identified, among which some contain structural features that make them potential allergens. The amounts of linalool and the major oxidation products were quantified over time, using GC and an HPLC-method, suitable for the analysis of thermolabile primary oxidation products. The hydroperoxide 7-hydroperoxy-3,7-dimethylocta-1,5-diene-3-ol was found to be present in 15% in an oxidized sample. The local lymph node assay (LLNA) was used to investigate the sensitizing potential of pure linalool, two samples of air-exposed linalool, and oxidation products of linalool (an alpha,beta-unsaturated aldehyde, a mixture of two hydroperoxides, and an alcohol). Pure linalool showed no sensitizing potential. The air-exposed samples of linalool produced clearly positive responses, and the hydroperoxides were the strongest allergens of the tested oxidation products. The study demonstrates the importance of autoxidation on the sensitizing potential of linalool. We also conclude that the sensitizing potential differs with the composition of the oxidation mixture and thus with the air exposure time.
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| 48. |
- Sköld, Maria, 1976, et al.
(författare)
-
Studies on the autoxidation and sensitizing capacity of the fragrance chemical linalool, identifying a linalool hydroperoxide.
- 2002
-
Ingår i: Contact dermatitis. - 0105-1873. ; 46:5, s. 267-72
-
Tidskriftsartikel (refereegranskat)abstract
- Fragrances are among the most common causes of allergic contact dermatitis. The two monoterpenes linalool and d-limonene are the most frequently incorporated fragrance chemicals in scented products. Previous studies on d-limonene show that this monoterpene oxidizes on air exposure (autoxidation) and that allergenic oxidation products are formed. Due to structural similarities, linalool might also form allergenic oxidation products on air exposure. The aim of the present study was to study the autoxidation of linalool and to investigate the sensitizing potential of linalool before and after air exposure. Linalool was oxidized for 10 weeks and gas chromatographic analyses showed that the content of linalool decreased to about 80%. The chromatograms revealed the formation of other compounds during oxidation. One of the major oxidation products was isolated and identified as 7-hydroperoxy-3,7-dimethyl-octa-1,5-diene-3-ol. This substance is, to the best of our knowledge, described for the first time. In sensitization studies in guinea pigs, linalool of high purity gave no reactions, while linalool that had been oxidized for 10 weeks sensitized the animals. It is concluded that autoxidation of linalool is essential for its sensitizing potential.
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| 49. |
- Sköld, Maria, 1976, et al.
(författare)
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The fragrance chemical beta-caryophyllene-air oxidation and skin sensitization.
- 2006
-
Ingår i: Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association. - : Elsevier BV. - 0278-6915. ; 44:4, s. 538-45
-
Tidskriftsartikel (refereegranskat)abstract
- Fragrances are common causes of allergic contact dermatitis. beta-Caryophyllene is a sesquiterpene that is used as a fragrance chemical. Analogous to the monoterpenes R-limonene and linalool, it can be expected to autoxidize when air exposed. The aim of the present study was to investigate the autoxidation of beta-caryophyllene and to evaluate the effect on the contact allergenic activity. beta-Caryophyllene started to oxidize immediately when air exposed and after 5 weeks almost 50% of the original compound was consumed. Caryophyllene oxide was found to be the major oxidation product. Hydroperoxides of beta-caryophyllene could not be detected in the oxidation mixture. Caryophyllene oxide was shown to be an allergen of moderate strength and beta-caryophyllene air exposed for 10 weeks showed a weak sensitizing capacity in the local lymph node assay. The study reveals that the allergenic activity of beta-caryophyllene is affected by autoxidation, but to a lesser extent when compared to R-limonene and linalool. The present findings support our results in clinical studies showing oxidized beta-caryophyllene to be a rather rare sensitizer compared to oxidized R-limonene and linalool.
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| 50. |
- Steinhoff, Franciska S., et al.
(författare)
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Cyanobacteria in Scandinavian coastal waters - A potential source for biofuels and fatty acids?
- 2014
-
Ingår i: Algal Research. - : Elsevier BV. - 2211-9264. ; 5, s. 42-51
-
Tidskriftsartikel (refereegranskat)abstract
- Since land-based biofuel production competes with conventional food production, a water-based biomass and biofuel production from cyanobacteria offers large potential. This study investigates the application potential of cyanobacteria for fuel production and by-products by mimicking nutrient depleted environmental conditions. Three Baltic cyanobacteria strains (Aphanizomenon flos-aquae, Dolichospermum lemmermannii and Nodularia spumigena) were inoculated in full nutrient levels, as well as phosphorus and nitrogen depleted medium, before being monitored for 14 days. For screening reasons, multiple parameters such as fatty acids, photosynthetic pigments including phycobilins, biovolume, photosynthetic activity, inorganic nutrients, particulate organic carbon, nitrogen and phosphorous were investigated every seven days. We observed a strong negative relationship between lipid content, growth and nutrient availability, resulting in high lipid and pigment production in combination with a limited growth rate in nutrient depleted treatments. Our results suggest that cultivation and harvest of bloom-forming cyanobacteria for fuel and by-product production are feasible in Scandinavia, but strongly depends on the desired compounds and biomass. Each cyanobacteria species originally has a species-specific chemical fingerprint that may be modified by rearing conditions and harvesting period to meet the needs of the consumer. This leads to important conclusions regarding future culturing conditions and biomass production of the desired compounds.
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