| 1. |
- Bellman, Jakob, et al.
(författare)
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Loading enhances glucose uptake in muscles, bones, and bone marrow of lower extremities in humans.
- 2024
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Ingår i: The Journal of clinical endocrinology and metabolism. - 1945-7197.
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Tidskriftsartikel (refereegranskat)abstract
- Increased standing time has been associated with improved health, but the underlying mechanism is unclear.We herein investigate if increased weight loading increases energy demand and thereby glucose uptake (GU) locally in bone and/or muscle in the lower extremities.In this single-center clinical trial with randomized crossover design (ClinicalTrials.gov ID, NCT05443620), we enrolled 10 men with body mass index (BMI) between 30 and 35kg/m2. Participants were treated with both high load (standing with weight vest weighing 11% of body weight) and no load (sitting) on the lower extremities. GU was measured using whole-body quantitative positron emission tomography/computed tomography (PET/CT) imaging. The primary endpoint was the change in GU ratio between loaded bones (i.e. femur and tibia) and non-loaded bones (i.e. humerus).High load increased the GU ratio between lower and upper extremities in cortical diaphyseal bone (e.g. femur/humerus ratio increased by 19%, p=0.029), muscles (e.g. m. quadriceps femoris/m. triceps brachii ratio increased by 28%, p=0.014) and in certain bone marrow regions (femur/humerus diaphyseal bone marrow region ratio increased by 17%, p=0.041). Unexpectedly, we observed the highest GU in the bone marrow region of vertebral bodies, but its GU was not affected by high load.Increased weight-bearing loading enhances GU in muscles, cortical bone, and bone marrow of the exposed lower extremities. This could be interpreted as increased local energy demand in bone and muscle caused by increased loading. The physiological importance of the increased local GU by static loading remains to be determined.
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| 2. |
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| 3. |
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| 4. |
- Berg Jansson, Anna, et al.
(författare)
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Professional Position Positioned: The Interwoven Experience of Being a Young Adult and New at Work Analysed from a Relational Perspective of Age
- 2024
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Ingår i: Young - Nordic Journal of Youth Research. - : Sage Publications. - 1103-3088 .- 1741-3222. ; 32:2, s. 142-159
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Tidskriftsartikel (refereegranskat)abstract
- To gain an in-depth understanding of the position of being a young adult and new at work simultaneously, this study examines the doing of age in relation to others in the lives of young adults, rather than focusing on age as a category and/or developmental phase. The study focuses on being a young adult from a critical and relational perspective of age. Based on focus group interviews with young adults, mostly women, working in retail, the aim is to analyse the position of being a young adult while new at work through age-marked relationships. The results reveal how this position can be understood both in terms of security and insecurity. Security arises in the sense of opportunities for learning and leaving responsibilities to older and more experienced colleagues. Insecurity arises in the sense of being exposed to insecure employment, the risk of being allocated less challenging tasks and being judged for failures.
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| 5. |
- Blom, Tobias, et al.
(författare)
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An In-Situ Prepared Nano-Manipulator Tip for Electrical Characterization of Free Standing Graphene Like Sheets Inside a Focused Ion Beam/Scanning Electron Microscope
- 2011
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Ingår i: Journal of Nanoelectronics and Optoelectronics. - : American Scientific. - 1555-130X .- 1555-1318. ; 6:2, s. 162-168
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Tidskriftsartikel (refereegranskat)abstract
- Although contacting and moving atoms has been demonstrated using probe techniques, for many nano-objects, a fast and reproducible nano-probe technique is needed to acquire a large number of electrical measurements on nano-objects that are often similar but not the identical. Nano-manipulators have become a common tool in many scanning electron microscopes (SEM) and focussed ion beam devices (FIB). They can be rapidly and reproducibly moved from one nano-object to another. In this work we present a procedure to obtain reproducible electrical measurements of nano- to micron-sized objects by using a sharp, tungsten tip with well defined surface properties. The tip is a part of a manipulator and is sharpened in-situ by using the gallium ion beam inside a focused ion beam/scanning electron microscope (FIB/SEM). The contact resistance between a Au surface and the tip is 70 kΩ before the sharpening procedure and 10 Ω after sharpening. The leakage current of the total set-up of 10pA makes it possible to measure currents through a variety of nano-objects. This measurement technique is applied to measure the resistance of as grown, water treated and two HCl treated carbon nanosheets (CNS). These CNS vary in size and morphology. Using this nano-contacting set-up, we could obtain measurements of more than 400 different CNS. The obtained histograms allow us to observe a clear decrease of the resistance between original and 3 hour acid treated CNSs. We observe that longer periods of exposure of the CNS to the HCl do not further modify the resistance.
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| 6. |
- Bollati, Michela, et al.
(författare)
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Structure and functionality in flavivirus NS-proteins : perspectives for drug design
- 2010
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Ingår i: Antiviral Research. - : Elsevier BV. - 0166-3542 .- 1872-9096. ; 87:2, s. 125-148
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Forskningsöversikt (refereegranskat)abstract
- Flaviviridae are small enveloped viruses hosting a positive-sense single-stranded RNA genome. Besides yellow fever virus, a landmark case in the history of virology, members of the Flavivirus genus, such as West Nile virus and dengue virus, are increasingly gaining attention due to their re-emergence and incidence in different areas of the world. Additional environmental and demographic considerations suggest that novel or known flaviviruses will continue to emerge in the future. Nevertheless, up to few years ago flaviviruses were considered low interest candidates for drug design. At the start of the European Union VIZIER Project, in 2004, just two crystal structures of protein domains from the flaviviral replication machinery were known. Such pioneering studies, however, indicated the flaviviral replication complex as a promising target for the development of antiviral compounds. Here we review structural and functional aspects emerging from the characterization of two main components (NS3 and NS5 proteins) of the flavivirus replication complex. Most of the reviewed results were achieved within the European Union VIZIER Project, and cover topics that span from viral genomics to structural biology and inhibition mechanisms. The ultimate aim of the reported approaches is to shed light on the design and development of antiviral drug leads.
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| 7. |
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| 8. |
- Erikshammar, Jarkko, et al.
(författare)
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Industriellt träbyggande förenar ekonomi och byggbarhet
- 2010
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Ingår i: Samhällsbyggaren. - 2000-2408. ; :2, s. 32-35
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Industrialized Timber Housing is based on repetition of the predefined building processes compared with traditional building where the business transaction and the customer are arranged into unique projects. Since the construction process consists of recurring activities, the industrial methods do not only improve the design and production phase, but the positive impact stretches well into the management phase. The market today can be offered cost-effective housing, with higher flexibility and better quality if the client, contractor and supplier takes control of the construction process.
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| 9. |
- Fredin, Maria Fritsch, 1970, et al.
(författare)
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Predicting and monitoring colitis development in mice by micro-computed tomography
- 2008
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Ingår i: Inflammatory Bowel Diseases. - : Oxford University Press (OUP). - 1078-0998 .- 1536-4844. ; 14:4, s. 491-499
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Computed tomography (CT) has been developed as a tool for monitoring human inflammatory bowel disease (IBD). The aim of this study was to evaluate colon wall thickness as a noninvasive marker in the dextran sodium sulfate (DSS) mouse model of colitis using micro-CT. METHODS: Mice were examined by micro-CT 1, 2, or 4 times between day 0 (d0) and d26 after induction of colitis to document the kinetics of changes in colon wall thickness and its relation to colitis development. RESULTS: DSS-treated mice displayed a significantly thicker colon wall at all timepoints (days 5, 8, 12, 19, and 26) investigated compared to healthy controls. Colon wall thickness showed a good correlation to the macroscopic grading of colitis (r = 0.81). The increase in colon wall thickness occurred mainly during the acute phase of colitis (between days 5 and 12) and did not progress much further in the chronic phase of colitis (d26). Colon wall thickness at d26 was thereby predicted by measurements at d12. All mice did not respond equally to DSS and this difference was manifest during the first 2 weeks of colitis, providing an important tool in stratifying responders from nonresponders. CONCLUSIONS: While the potential impact of handling and anesthesia should be considered on repeated micro-CT, irradiation exposure during repeated micro-CT did not affect the development of colitis. Thus, the results suggest that micro-CT can be used for monitoring and prediction of the inflammatory response in mouse colitis in future therapeutic studies.
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| 10. |
- Grennberg, Helena, et al.
(författare)
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Functionalization and Area-Selective Deposition of Magnetic Carbon-Coated Iron Nanoparticles from Solution
- 2011
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Ingår i: Journal of Nanotechnology. - : Hindawi publishing. - 1687-9503 .- 1687-9511. ; , s. 342368-
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Tidskriftsartikel (refereegranskat)abstract
- A route to area-selective deposition of carbon-coated iron nanoparticles, involving chemical modification of the surface of the particles, is described. Partial oxidative etching of the coating introduces carboxylic groups, which then are esterified. The functionalized particles can be selectively deposited on the Si areas of Si/SiO2 substrates by a simple dipping procedure. Nanoparticles and nanoassemblies have been analyzed using SEM, TEM, and XPS.
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| 11. |
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| 12. |
- Jafri, Hassan, et al.
(författare)
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Control of Conductivity in Graphene by Formation of Defects
- 2008
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Ingår i: AVS 55th International Symposium & Exhibition 2008, October 19-24, Boston, USA.
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Konferensbidrag (refereegranskat)abstract
- Due to their large surface areas, the conductivity of graphene and carbonnano-sheets depends strongly on their chemical environment. This is thebase for future environmental sensors containing graphene sheets. Here, abinitiocalculations propose a possibility of conductivity increase. In theexperiment, a 1-2 orders of magnitude increase of the conductivity isobserved experimentally on sub-nanometTe carbon nano-sheets by using anin-situ nano-manipulation set-up. The conductivity of the graphene sheetswas assessed from first-principle simulations. Insertion of defects in thegraphene sheets can lead to a strong increase of the conductivity of singlegraphene sheets. To study this result experimentally, we carried outconductivity measurements on sub-nanometre graphene nano-sheets that aredeposited on W -substrates by radio-frequency plasma-enhanced chemicalvapour deposition. This deposition process creates free-standingmicrometer-sized carbon nano-sheets with sub-nanometre thickness. Thesenano-sheets were exposed to an acid treatment. It has been shown recentlythat such acid treatment creates defects in these sheets. Using a nanomanipulatorinside a scanning electron microscope, we individuallycontacted the nano-sheets and measured their resistance as a function oftheir functionalization. From more than 1000 measurements we obtain a 1-2order of magnitude increase of conductivity in the functionalised carbonnano-sheets as compared to just water treated or untreated carbon nanosheets.This result corresponds well to the conductivity change obtainedfrom theory. This study makes it possible to create environmental sensorsbased on graphene like carbon nano-sheets.
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| 13. |
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| 14. |
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| 15. |
- Jafri, Syed Hassan Mujtaba, et al.
(författare)
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Conductivity engineering of graphene by defect formation
- 2010
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Ingår i: Journal of Physics D. - : IOP Publishing. - 0022-3727 .- 1361-6463. ; 43:4, s. 045404-
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Tidskriftsartikel (refereegranskat)abstract
- Transport measurements have revealed several exotic electronic properties of graphene. The possibility to influence the electronic structure and hence control the conductivity by adsorption or doping with adatoms is crucial in view of electronics applications. Here, we show that in contrast to expectation, the conductivity of graphene increases with increasing concentration of vacancy defects, by more than one order of magnitude. We obtain a pronounced enhancement of the conductivity after insertion of defects by both quantum mechanical transport calculations as well as experimental studies of carbon nano-sheets. Our finding is attributed to the defect induced mid-gap states, which create a region exhibiting metallic behaviour around the vacancy defects. The modification of the conductivity of graphene by the implementation of stable defects is crucial for the creation of electronic junctions in graphene-based electronics devices.
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| 16. |
- Jansson, Erika
(författare)
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Ontogenetic Characterization of Müllerian Duct Development and Expression of anti-Müllerian hormone and Other Genes : New Endpoints in the Frog Xenopus tropicalis Test System
- 2015
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The amphibian model-species Xenopus tropicalis is used in reproductive toxicology studies. Lifecycle studies are requested but they are time consuming and susceptible to several of the risks attributed to long-term studies. Herein, the ontogenetic expression of genes associated to gonads and Müllerian ducts and the early Müllerian duct development were characterized as well as explored as suitable early juvenile endpoints after developmental levonorgestrel (LNG) exposure. The urogenital mRNA expression of the anti-Müllerian hormone (amh) was male-biased while the cytochrome P450 19a1 (cyp19a1) mRNA expression was female-biased from the Nieuwkoop and Faber developmental stage (NF) 50, to 4 weeks post-metamorphosis. amh expression in combination with cyp19a1 expression is proposed to constitute a robust marker of phenotypic sex during gonadal differentiation in amphibians. The expression of the amh receptor 2 (amhr2) was characterized for the first time in amphibians. amhr2 was expressed higher in putative females than in males from NF 56, suggesting a role in ovarian development. The mRNA levels of intracellular and membrane progesterone receptors (ipgr and mpgr beta) respectively increased and decreased as the tadpole developed into a juvenile frog, indicating different roles for these genes during development. Exposure to LNG modulated the mRNA expression of the amh and pgrs in a sex and developmental stage dependent manner, suggesting the involvement of these genes in the LNG mode of action. The Müllerian ducts were first observed at NF 64 in both sexes and grew into distinct tubules, larger in females than in males at 4 weeks post-metamorphosis. Therefore, 4 weeks post-metamorphosis is suggested as a suitable early juvenile stage for investigation into disruptions of female reproductive organ development. In conclusion, the protein Amh is suggested to be involved in testicular differentiation and to be a reliable testicular marker during gonadal differentiation, even after developmental LNG exposure, in amphibians.
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| 17. |
- Jansson, Erika, et al.
(författare)
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Presence of alkylresorcinols, potential whole grain biomarkers, in human adipose tissue
- 2010
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Ingår i: British Journal of Nutrition. - 0007-1145 .- 1475-2662. ; 104:5, s. 633-636
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Tidskriftsartikel (refereegranskat)abstract
- Alkylresorcinols (AR) in plasma samples have been suggested to be short- to medium-term biomarkers of whole grain wheat and rye intake. In the present study, we investigated whether AR are present in human adipose tissues, and if content correlated with long-term whole grain bread intake. Furthermore, we investigated if the relative AR homologue composition reflected what has been found previously in the habitual diet of Swedes. Biopsy samples (10-25 mg) from free-living Swedish women (n 20) were analysed by GC-MS. The mean total AR concentration in the samples was 0.54 (SD 0.35) microg/g, ranging from below limit of quantification ( < 0.08 microg/g) to 1.50 microg/g. Whole grain bread intake was significantly correlated with plasma total AR content (r 0.48, P < 0.05), and the C17 : 0/C21 : 0 ratio was 0.35 (sd 0.24), which is similar to what is found in plasma among free-living subjects consuming a mixed whole grain wheat and rye diet. These results suggest that AR in the adipose tissue should be evaluated as a long-term biomarker of whole grain wheat and rye intake.
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| 18. |
- Jansson, Erika, et al.
(författare)
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Sex-dependent expression of anti-Müllerian hormone (amh) and amh receptor 2 during sex organ differentiation and characterization of the Müllerian duct development in Xenopus tropicalis
- 2016
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Ingår i: General and Comparative Endocrinology. - : Elsevier BV. - 0016-6480 .- 1095-6840. ; 229, s. 132-144
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Tidskriftsartikel (refereegranskat)abstract
- Amphibian gonadal differentiation involves the action of sex steroids. Recent research indicates that the anti-Müllerian hormone (AMH) is involved in testicular development in some lower vertebrate species. For amphibians there is a lack of data on ontogenetic expression of the AMH receptor AMHR2/amhr2 and of progesterone receptors (PGRS/pgrs). Here we expand the knowledge on amphibian sex differentiation by characterizing ontogenetic mRNA levels of amh, amhr2, intracellular and membrane pgrs (ipgr and mpgr beta) and cytochrome P450 19a1 (cyp19a1) (ovarian marker) in the urogenital complex of the model species Xenopus (Silurana) tropicalis. Furthermore, we characterized the ontogenetic development of the Müllerian ducts (precursors of the female reproductive tract) histologically. The developmental period investigated spanned from beginning of gonadal differentiation, Nieuwkoop and Faber (NF) stage 51, to 4weeks post-metamorphosis. The Müllerian ducts were first observed at NF 64 in both sexes. Male-enhanced amh mRNA levels from NF 53/54 to 6days post-metamorphosis and female-enhanced cyp19a1 levels from NF 53 to 4weeks post-metamorphosis were noted. The sexually dimorphic mRNA level profile was more distinct for amh than for cyp19a1. The pgrs mRNA levels increased over the studied period and showed no sex differences. At later developmental stages, the amhr2 mRNA level was increased in putative females compared with males. Our findings suggest that AMH has a role in gonadal differentiation in X. tropicalis. We propose relative gonadal amh mRNA level as a testicular marker during early gonadal development in amphibians.
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| 19. |
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| 20. |
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| 21. |
- Johansson, Anders, et al.
(författare)
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Fabrication of High-Aspect-Ratio Prussian Blue Nanotubes Using a Porous Alumina Template
- 2005
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Ingår i: Nano Letters. - : American Chemical Society (ACS). - 1530-6984 .- 1530-6992. ; 5:8, s. 1603-1606
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Tidskriftsartikel (refereegranskat)abstract
- Prussian blue nanotubes were fabricated by using a sequential deposition technique inside the 60-nm well-ordered pores of anodic alumina. By varying the deposition parameters and the dimensions of the template, we could tailor the length and the outer as well as the inner diameter of the tubes. The nanotubes were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD).
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| 22. |
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| 23. |
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| 24. |
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| 25. |
- Orton, Frances, et al.
(författare)
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A laboratory investigation into features of morphology and physiology for their potential to predict reproductive success in male frogs
- 2020
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 15:11
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Tidskriftsartikel (refereegranskat)abstract
- Amphibian populations are declining globally, however, the contribution of reduced reproduction to declines is unknown. We investigated associations between morphological (weight/snout-vent length, nuptial pad colour/size, forelimb width/size) and physiological (nuptial pad/testis histomorphology, plasma hormones, gene expression) features with reproductive success in males as measured by amplexus success and fertility rate (% eggs fertilised) in laboratory maintained Silurana/Xenopus tropicalis. We explored the robustness of these features to predict amplexus success/fertility rate by investigating these associations within a sub-set of frogs exposed to anti-androgens (flutamide (50 μg/L)/linuron (9 or 45 μg/L)). In unexposed males, nuptial pad features (size/colour/number of hooks/androgen receptor mRNA) were positively associated with amplexus success, but not with fertility rate. In exposed males, many of the associations with amplexus success differed from untreated animals (they were either reversed or absent). In the exposed males forelimb width/nuptial pad morphology were also associated with fertility rate. However, a more darkly coloured nuptial pad was positively associated with amplexus success across all groups and was indicative of androgen status. Our findings demonstrate the central role for nuptial pad morphology in reproductive success in S. tropicalis, however, the lack of concordance between unexposed/exposed frogs complicates understanding of the utility of features of nuptial pad morphology as biomarkers in wild populations. In conclusion, our work has indicated that nuptial pad and forelimb morphology have potential for development as biomarkers of reproductive health in wild anurans, however, further research is needed to establish this.
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| 26. |
- Orton, F., et al.
(författare)
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Exposure to an anti-androgenic herbicide negatively impacts reproductive physiology and fertility in Xenopustropicalis
- 2018
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Amphibians are threatened on a global scale and pollutants may be contributing to population declines, but how chemicals impact on their reproduction is poorly understood. We conducted a life cycle analysis to investigate the impacts of early life exposure to two anti-androgens (exposure until completion of metamorphosis;stage 66): flutamide, (50 µg/L)/linuron (9 and 45 µg/L)) on sexual development and breeding competence in Xenopus tropicalis. Our analyses included: mRNA levels of dmrt1, cyp17, amh, cyp19, foxl2 and ar (tadpoles/metamorphs), gonadal histomorphology (metamorphs/adults), mRNA levels of ar/gr (adult male brain/gonad/forelimb), testosterone/corticosterone levels (adult males), secondary sexual characteristics (forelimb width/nuptial pad: adult males) and breeding competence (amplexus/fertility: adult males). Compared to controls, feminised sex ratios and increased number of spermatogonia (adults) were observed after exposure to flutamide and the lower linuron concentration. Exposure to the lower linuron concentration also resulted in demasculinisation of secondary sexual characteristics and reduced male fertility. Flutamide exposure resulted in masculinisation of the nuptial pad and elevated mRNA levels of dmrt1, cyp17, amh and foxl2 in brains (metamorphs). Testosterone levels were higher in all treatment groups, however, overall few effects were observed in response to the higher linuron concentration. Our findings advance understanding of reproductive biology of X. tropicalis and illustrate negative effects of linuron on reproductive processes at a concentration measured in freshwater environments.
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| 27. |
- Quinlan, Ronald A., et al.
(författare)
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Transfer of carbon nanosheet films to nongrowth, zero thermal budget substrates
- 2011
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Ingår i: Journal of Vacuum Science & Technology B. - : American Vacuum Society. - 1071-1023 .- 1520-8567. ; 29:3, s. 030602-
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Tidskriftsartikel (refereegranskat)abstract
- Carbon-based nanostructures and materials have become a popular subject of research due to their unique thermal, mechanical, electrical, and optical properties. For example, the strong C-C bonds of graphene-based systems allow for excellent thermal conduction at room temperature and the conjugation of the sp(2) lattice enables extremely high electron mobility. However, the use of carbon nanostructures as a component in polymer composites, sensors, mirco-electro-mechanical systems, and both rigid and flexible electronics has been limited by several factors, including the incompatibility with standard photolithography techniques, the high temperatures required for the nanostructure growth, and the presence of-or complication-of removing noncarbon species. Here, the authors report on a novel method for the transfer of carbon nanosheets to a low or zero thermal budget substrate while maintaining their original morphology and electrical properties. Four-point probe measurements' post-transfer shows the retention of in-plane conductivity and scanning electron microscopy reveals the preservation of the original vertical morphology. Raman spectroscopy measurements confirm the retention of the graphitic structure of the post-transfer nanosheet film. This new transfer technique builds on the ability to conformally coat nanosheets while maintaining the original ultrahigh surface area morphology and the ability to fully incorporate nanosheets into several polymers while maintaining the original nanostructure separation. For a demonstration of the usefulness of polymer filling, carbon nanosheets were used as an ultrahigh surface area electrode for the photoactive polymer poly[2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene] in proof of principle experiments of a nanosheet-based organic photovoltaic device.
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| 28. |
- Rooth, Mårten, et al.
(författare)
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Atomic layer deposition of titanium dioxide nanostructures using carbon nanosheets as a template
- 2009
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Ingår i: Journal of Crystal Growth. - : Elsevier BV. - 0022-0248 .- 1873-5002. ; 311:2, s. 373-377
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Tidskriftsartikel (refereegranskat)abstract
- Nanostructured films of anatase TiO2 is deposited on carbon nanosheet (CNS) templates using atomic layer deposition (ALD). The high-surface area of the CNS together with the unique step coverage of the ALD process makes it possible to obtain sheet-like TiO2 nanostructures, for use in potential applications, e.g. photocatalysis and photovoltaics. A problem with ALD on CNS was the low nucleation rate giving TiO2 films with pinholes. It is shown that introduction of defects by an acid-treatment process can be used to control initial nucleation and growth of the films. The TiO2 on the defect-rich CNS nucleates faster and results in a film with no observable pinholes consisting of crystalline grains in an amorphous matrix.
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| 29. |
- Rubino, Stefano, 1978-, et al.
(författare)
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In-situ contacting of nanosheets and remote EMCD
- 2009
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Ingår i: 2nd International Workshop on Remote Electron Microscopy and In Situ Studies, Gothenburg, Sweden 16-18 November 2009.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 30. |
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| 31. |
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| 32. |
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| 33. |
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| 34. |
- Säfholm, Moa, et al.
(författare)
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Mixture effects of levonorgestrel and ethinylestradiol : Estrogenic biomarkers and hormone receptor mRNA expression during sexual programming
- 2015
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Ingår i: Aquatic Toxicology. - : Elsevier BV. - 0166-445X .- 1879-1514. ; 161, s. 146-153
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Tidskriftsartikel (refereegranskat)abstract
- Synthetic progesterone (progestins) and estrogens are widely used pharmaceuticals. Given that their simultaneous unintentional exposure occurs in wildlife and also in human infants, data on mixture effects of combined exposures to these hormones during development is needed. Using the Xenopus (Silurana) tropicalis test system we investigated mixture effects of levonorgestrel (LNG) and ethinylestradiol (EE2) on hormone sensitive endpoints. After larval exposure to LNG (0.1 nM), or EE2 (0.1 nM) singly, or in combination with LNG (0.01, 0.1, 1.0 nM), the gonadal sex ratio was determined histologically and hepatic mRNA levels of genes encoding vitellogenin (vtg beta1) and the estrogen (esr1, esr2), progesterone (ipgr) and androgen (or) receptors were quantified using quantitative PCR. All EE2-exposed groups showed female-biased sex ratios and increased vtgbeta1 mRNA levels compared with the controls. Compared with the EE2-alone group (positive control) there were no significant alterations in vtg betal levels or in sex ratios in the co-exposure groups. Exposure to LNG-alone caused an increase in ar mRNA levels in females, but not in males, compared to the controls and the co-exposed groups, indicating that co-exposure to EE2 counteracted the LNG-induced or levels. No treatment related impacts on the mRNA expression of esr1, esr2, and ipgr in female tadpoles were found, suggesting that these endpoints are insensitive to long-term exposure to estrogen or progestin. Due to the EE2-induced female-biased sex ratios, the mRNA expression data for the low number of males in the EE2-exposed groups were not statistically analyzed. In conclusion, our results suggest that induced vtg expression is a robust biomarker for estrogenic activity in exposure scenarios involving both estrogens and progestins. Developmental exposure to LNG caused an induction of hepatic or mRNA expression that was antagonized by combined exposure to EE2 and LNG. To our knowledge this is the first study to report effects of combined exposures to EE2 and LNG during the period of sexual programming. (C) 2015 Elsevier B.V. All rights reserved.
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| 35. |
- Säfholm, Moa, et al.
(författare)
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Molecular and histological endpoints for developmental reproductive toxicity in Xenopus tropicalis : Levonorgestrel perturbs anti-Mullerian hormone and progesterone receptor expression
- 2016
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Ingår i: Comparative Biochemistry and Physiology - Part C. - : Elsevier BV. - 1532-0456 .- 1878-1659. ; 181, s. 9-18
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Tidskriftsartikel (refereegranskat)abstract
- There is an increasing concern regarding the risks associated with developmental exposure to endocrine disrupting chemicals and the consequences for reproductive capability. The present study aimed to refine the Xenopus (Silurana) tropicalis test system for developmental reproductive toxicity by characterising molecular and histological features of sexual development, and to explore effects of exposure to the progestagen levonorgestrel (LNG). Larvae were exposed to LNG (0, 3, 30, 300 ng/L) over the first three weeks of development, encompassing the beginning of gonadal differentiation. mRNA levels of amh (anti-Mullerian hormone), amhr2 (amh receptor 2), ipgr (intracellular progesterone receptor), mpgr beta (membrane progesterone receptor beta), and cyp19a1 (cytochrome p450 19a1) were quantified in larvae and juveniles (4 weeks post-metamorphosis). Relative cyp19a1 and amh expression was used as a molecular marker for phenotypic sex of larvae. Gonadal and Mullerian duct development were characterised histologically in juveniles. Compared to controls, LNG exposure increased the expression of amh and ipgr in male larvae. In juveniles, mpgr beta expression was increased in both sexes and amhr2 expression was decreased in males, implying persistent effects of developmental progestagen exposure on amh and pgr expression signalling. No effects of LNG on the gonadal or Mullerian duct development were found, implying that the exposure window was not critical with regard to these endpoints. In juveniles, folliculogenesis had initiated and the Mullerian ducts were larger in females than in males. This new knowledge on sexual development in X. tropicalis is useful in the development of early life-stage endpoints for developmental reproductive toxicity.
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| 36. |
- Todisco, Gabriele, et al.
(författare)
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Integrated Genomic and Transcriptomic Analysis Improves Disease Classification and Risk Stratification of MDS with Ring Sideroblasts
- 2023
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Ingår i: Clinical Cancer Research. - 1078-0432 .- 1557-3265. ; 29:20, s. 4256-4267
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Ring sideroblasts (RS) define the low-risk myelodysplastic neoplasm (MDS) subgroup with RS but may also reflect erythroid dysplasia in higher risk myeloid neoplasm. The benign behavior of MDS with RS (MDSRSþ) is limited to SF3B1-mutated cases without additional high-risk genetic events, but one third of MDSRSþ carry no SF3B1 mutation, suggesting that different molecular mechanisms may underlie RS formation. We integrated genomic and transcriptomic analyses to evaluate whether transcriptome profiles may improve current risk stratification. Experimental Design: We studied a prospective cohort of MDSRSþ patients irrespective of World Health Organization (WHO) class with regard to somatic mutations, copy-number alterations, and bone marrow CD34þ cell transcriptomes to assess whether transcriptome profiles add to prognostication and provide input on disease classification. Results: SF3B1, SRSF2, or TP53 multihit mutations were found in 89% of MDSRSþ cases, and each mutation category was associated with distinct clinical outcome, gene expression, and alternative splicing profiles. Unsupervised clustering analysis identified three clusters with distinct hemopoietic stem and progenitor (HSPC) composition, which only partially overlapped with mutation groups. IPSS-M and the transcriptome-defined proportion of megakaryocyte/erythroid progenitors (MEP) independently predicted survival in multivariable analysis. Conclusions: These results provide essential input on the molecular basis of SF3B1-unmutated MDSRSþ and propose HSPC quantification as a prognostic marker in myeloid neoplasms with RS.
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| 37. |
- Vossen, L. E., et al.
(författare)
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Fasting increases shelter use in house crickets (Acheta domesticus)
- 2022
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Ingår i: JOURNAL OF INSECTS AS FOOD AND FEED. - : Wageningen Academic Publishers. - 2352-4588. ; 8:1, s. 5-8
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Tidskriftsartikel (refereegranskat)abstract
- Fasting, i.e. depriving the animals of food prior to harvesting, has been practised in the production of house crickets (Acheta domesticus). However, the effectiveness of this method in reducing microbial loads is still unclear. In addition, there may be costs of fasting to the organism, which could compromise product quality and animal welfare. Here, we analysed spontaneous behaviour displayed after 0, 24 or 48 hours of fasting. We show that after 48 hours of fasting, shelter use was increased and the duration spent on the exposed area of the floor was decreased. The same trend was seen after 24 hours fasting. Moreover, in both fasting treatments, a strong reduction in grooming was seen. We conclude that, in the absence of a microbial lowering effect of fasting and considering the current finding that fasting induces behavioural responses in crickets, there is currently no scientific support for using fasting in cricket production.
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| 38. |
- Vossen, L. E., et al.
(författare)
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Open field behavior in the house cricket (Acheta domesticus) : effect of illumination, sex differences and individual consistency
- 2023
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Ingår i: JOURNAL OF INSECTS AS FOOD AND FEED. - : Wageningen Academic Publishers. - 2352-4588. ; 9:3, s. 317-324
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Tidskriftsartikel (refereegranskat)abstract
- Edible insects are worldwide promoted as an alternative protein, trace mineral and lipid source in animal feed and human food. The house cricket (Acheta domesticus) is already being reared at an industrial scale, yet current massrearing practices and facility design may still leave room for improvement. Behavioral tests have been suggested as an important assessment tool at the whole-organism level that can be used to find optimal housing conditions (e.g. density, diet, temperature). Here, we adapt the widely used open field test to the house cricket. We tested 16 male and 16 female house crickets four times under two different light intensities. Videos were analysed with EthovisionT tracking software and variables distance moved, velocity, and duration and frequency in zone were extracted. Results showed that house crickets, like vertebrate model species, spent most time close to the walls of the arena, and crossed the center zone with high velocity. Brighter illumination was associated with increased velocity, in particular in the center zone during the first test occasion, suggesting avoidance of this zone. Male crickets had higher locomotory activity than females. Consistency repeatabilities and intraclass correlation coefficients (ICCs) were moderate to high, and the correlation between subsequent occasions became stronger over the four occasions at day 1, 2, 3 and 7. The first test occasion differed from subsequent occasions, therefore repeated testing may be necessary when analysing experimental manipulations of small effect size. Overall, the results are promising for use of the open field test as a precise phenotyping tool.
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| 39. |
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| 40. |
- Wall, Erika, Docent, 1978-, et al.
(författare)
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Capturing Stories of How Young Adults Experience Entry Into the Workforce : A Qualitative Research Protocol on Data Collection During the Ongoing Coronavirus Pandemic
- 2021
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Ingår i: International Journal of Qualitative Methods. - : Sage Publications. - 1609-4069. ; 20
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Tidskriftsartikel (refereegranskat)abstract
- Background:In present research protocol, the project entitled “A sustainable working life for young adults—leadership, learning, and insecurity” is presented and discussed. The study which aims to describe and analyze the expectations of young adults in the retail workforce in terms of leadership, learning and development and how these aspects can be understood from a health promotion perspective. The project is limited to young adults (18–28 years) employed in a retail setting.Methods:The project is based on qualitative data collected through focus group interviews and individual interviews made during the ongoing coronavirus pandemic (COVID-19) in year 2020 what here will be reflected upon.Discussion:It is concluded data collection carried out during the ongoing spread of the coronavirus, may be significant to what interviewees highlighted in the interviews, but also to what was not discussed in the interviews. It may be the case that the increased focus on the coronavirus meant that other issues that are important to young adults as they establish themselves in the labor market were overshadowed.
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| 41. |
- Wall, Erika, Docent, 1978-, et al.
(författare)
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Sense of security when new at work : a thematic analysis of interviews with young adult retail workers in Sweden
- 2021
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Ingår i: International Journal of Workplace Health Management. - : Emerald Group Publishing Limited. - 1753-8351 .- 1753-836X. ; 14:6, s. 620-633
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Tidskriftsartikel (refereegranskat)abstract
- Purpose - Positive examples of situations in which young adults new at work experience feeling secure in the role as novice in the work force are here focused. The aim is to analyze how young adults who are new to the labor market express having a sense of security in the workplace. The long-term goal is to strengthen the conditions for the health and wellbeing of workers entering the retail labor market.Design/methodology/approach - Thirteen individual in-depth telephone/video-interviews were conducted with young adults (aged 18–28) working within the retail sector in Sweden. Using a thematic interview schedule, the interviews focused how the interviewees contextualizing stories on being novice at the labor market. The study is based on those parts of the material in which stories on feeling secure was expressed.Findings - The analysis resulted in two themes: A sense of security is related to carrying out work safely and a sense of security is related to receiving support. The first theme illuminates how work is structured and safety training respectively contributes to a sense of security and the latter reveal how social support from a variety of sources (managers, colleagues and others outside the work environment) contributes to a sense of security when new at work.Originality/value - Using a health promoting perspective, the study complements the existing perspectives of challenges faced by novices as they enter working life. Also, the study highlights the importance of including relations outside the workplace when searching for the understanding of the experiences of being new at work. The study indicates that focusing on the sense of security by well-structured work, safety training and social support might contribute to the strive for a sustainable working life for young adults.
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| 42. |
- Widenkvist, Erika
(författare)
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Fabrication and Functionalization of Graphene and Other Carbon Nanomaterials in Solution
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In the last decades several new nanostructures of carbon have been discovered, including carbon nanotubes (CNTs), and the recently discovered 2-dimensional graphene. These new materials exhibit extraordinary and unique properties—making them extremely interesting both for fundamental science and for future applications. It is, however, of crucial importance to develop new and improved fabrication and processing methods for these carbon nanomaterials. In this thesis the concept of applying solution chemistry and solution-based techniques to fabricate and to deposit graphene and other carbon nanomaterials is explored. An area-selective deposition method was developed for CNT and carbon-coated iron nanoparticles. By utilizing organic functionalization the properties of the nanomaterials were tuned, with the purpose to make them soluble in a liquid solvent and also enable them to selectively adsorb to non-polar surfaces. The first step of the functionalization process was an acid treatment, to introduce defects in the materials. This method was also used to create defects in so-called carbon nanosheets (CNS). The effect of the defect formation on the electric properties of the graphene-like CNS was studied; it was found that the resistance of the CNS could be reduced to 1/50 by acid treating of the sample. Also, the effect of the created defects on gas adsorption to the surface of the CNS has been investigated. This was done using atomic layer deposition (ALD) of TiO2 on the CNS, and a clear change in nucleation be-havior was seen due to the acid-treatment. Furthermore, a solution-based new method for fabrication of graphene was developed; this method combines intercalation of bromine into graphite with ultrasonic treatment to exfoliate flakes into a solvent. From the solvent the flakes can be deposited onto an arbitrary substrate. Several important parameters in the method were investigated in order to optimize the process. One important parameter proved to be the choice of solvent in all steps of the procedure; it was shown to influence sonication yield, flake size, and deposition results. Toluene was identified as a suitable solvent. A mild heat-treatment of the starting material was also identified as a way to increase the exfoliation yield. Using this method, fabrication of few-layer graphene sheets was achieved and areas down to 3 layers in thickness were identified—this is in the very forefront of current solution-based graphene fabrication techniques.
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| 43. |
- Widenkvist, Erika, et al.
(författare)
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Fabrication of graphene by bromine-intercalation and sonochemical exfoliation
- 2009
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Konferensbidrag (refereegranskat)abstract
- We present a method of producing suspensions of graphene sheets by combining intercalation and mild sonication. Ultrasonic treatment of graphite leads to the formation of small graphene-like flakes in solution. The delamination of the graphite is dramatically increased by intercalation of bromine. After ultrasonic treatment, large amounts of graphene-like flakes with varying thickness are observed in SEM and TEM. They can be adsorbed onto a surface of a suitable substrate by a simple dipping technique. The effect of polar and non-polar solvents as well as adsorption of the graphene on hydrophobic and hydrophilic substrates will be demonstrated and compared. Finally, the general approach of using ultrasonic treatment and intercalation as a facile route to graphene synthesis compared to other methods will be discussed.
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| 44. |
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| 45. |
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| 46. |
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| 47. |
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| 48. |
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| 49. |
- Widenkvist, Erika, et al.
(författare)
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Intercalation and Ultrasonic Treatment of Graphite : a New Synthetic Route to Graphene
- 2008
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Konferensbidrag (refereegranskat)abstract
- We will demonstrate that ultrasonic treatment of a graphite crystal in water can lead to the formation of small graphene-like flakes in solution. The delamination of the graphite can be increased dramatically by intercalation of bromine from a Br2-saturated water solution. After ultrasonic treatment, large amounts of graphene-like flakes with varying thickness are observed in SEM and TEM. They can be adsorbed onto a surface of a suitable substrate by a simple dipping technique. The effect of polar and non-polar solvents as well as adsorption of the graphene on hydrophobic and hydrophilic substrates will be demonstrated and compared. DFT calculations of the intercalation process have been carried out using the SIESTA package and the effect of bromine intercalation on cohesive energy and electronic structure will be discussed and compared with experimental data. Finally, the general approach of using ultrasonic treatment and intercalation as a facile route to graphene synthesis compared to other methods will be discussed.
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| 50. |
- Widenkvist, Erika, et al.
(författare)
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Mild sonochemical exfoliation of bromine-intercalated graphite a new route towards graphene
- 2009
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Ingår i: Journal of Physics D. - : IOP Publishing Ltd. - 0022-3727 .- 1361-6463. ; 42:11, s. 112003-
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Tidskriftsartikel (refereegranskat)abstract
- A method to produce suspensions of graphene sheets by combining solution-based bromine intercalation and mild sonochemical exfoliation is presented. Ultrasonic treatment of graphite in water leads to the formation of suspensions of graphite flakes. The delamination is dramatically improved by intercalation of bromine into the graphite before sonication. The bromine intercalation was verified by Raman spectroscopy as well as by x-ray photoelectron spectroscopy (XPS), and density functional theory (DFT) calculations show an almost ten times lower interlayer binding energy after introducing Br2 into the graphite. Analysis of the suspended material by transmission and scanning electron microscopy (TEM and SEM) revealed a significant content of few-layer graphene with sizes up to 30 µm, corresponding to the grain size of the starting material
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