| 1. |
- Boge, Lukas, 1987, et al.
(författare)
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Cubosomes for topical delivery of the antimicrobial peptide LL-37
- 2019
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Ingår i: European Journal of Pharmaceutics and Biopharmaceutics. - : Elsevier BV. - 1873-3441 .- 0939-6411. ; 134, s. 60-67
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Tidskriftsartikel (refereegranskat)abstract
- In this study, the use of cubosomes for topical delivery of the antimicrobial peptide (AMP) LL-37 was investigated. Topical delivery of AMPs is of great interest for treatment of skin infections caused by bacteria, such as Staphylococcus aureus. AMP containing cubosomes were produced by three different preparation protocols and compared: (i) pre-loading, where LL-37 was incorporated into a liquid crystalline gel, which thereafter was dispersed into nanoparticles, (ii) post-loading, where LL-37 was let to adsorb onto pre-formed cubosomes, and (iii) hydrotrope-loading, where LL-37 was incorporated during the spontaneously formed cubosomes in an ethanol/glycerol monooleate mixture. Particle size and size distribution were analyzed using dynamic light scattering (DLS), liquid crystalline structure by small angle x-ray scattering (SAXS) and release of LL-37 by a fluorescamine assay. Proteolytic protection of LL-37 as well as bactericidal effect after enzyme exposure was investigated. The skin irritation potential of cubosomes was examined by an in vitro epidermis model. Finally, the bacterial killing property of the cubosomes was examined by an ex vivo pig skin wound infection model with Staphylococcus aureus. Data showed that a high loading of LL-37 induced formation of vesicles in case of cubosomes prepared by sonication (pre-loading). No release of LL-37 was observed from the cubosomes, indicating strong association of the peptide to the particles. Proteolysis studies showed that LL-37 was fully protected against enzymatic attacks while associated with the cubosomes, also denoting strong association of the peptide to the particles. As a consequence, bactericidal effect after enzyme exposure remained, compared to pure LL-37 which was subjected to proteolysis. No skin irritation potential of the cubosomes was found, thus enabling for topical administration. The ex vivo wound infection model showed that LL-37 in pre-loaded cubosomes killed bacteria most efficient.
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| 2. |
- Boge, Lukas, et al.
(författare)
-
Cubosomes for topical delivery of the antimicrobial peptide LL-37
- 2019
-
Ingår i: European journal of pharmaceutics and biopharmaceutics. - : Elsevier BV. - 0939-6411 .- 1873-3441. ; 134, s. 60-67
-
Tidskriftsartikel (refereegranskat)abstract
- In this study, the use of cubosomes for topical delivery of the antimicrobial peptide (AMP) LL-37 was investigated. Topical delivery of AMPs is of great interest for treatment of skin infections caused by bacteria, such as Staphylococcus aureus. AMP containing cubosomes were produced by three different preparation protocols and compared: (i) pre-loading, where LL-37 was incorporated into a liquid crystalline gel, which thereafter was dispersed into nanoparticles, (ii) post-loading, where LL-37 was let to adsorb onto pre-formed cubosomes, and (iii) hydrotrope-loading, where LL-37 was incorporated during the spontaneously formed cubosomes in an ethanol/glycerol monooleate mixture. Particle size and size distribution were analyzed using dynamic light scattering (DLS), liquid crystalline structure by small angle x-ray scattering (SAXS) and release of LL-37 by a fluorescamine assay. Proteolytic protection of LL-37 as well as bactericidal effect after enzyme exposure was investigated. The skin irritation potential of cubosomes was examined by an in vitro epidermis model. Finally, the bacterial killing property of the cubosomes was examined by an ex vivo pig skin wound infection model with Staphylococcus aureus. Data showed that a high loading of LL-37 induced formation of vesicles in case of cubosomes prepared by sonication (pre-loading). No release of LL-37 was observed from the cubosomes, indicating strong association of the peptide to the particles. Proteolysis studies showed that LL-37 was fully protected against enzymatic attacks while associated with the cubosomes, also denoting strong association of the peptide to the particles. As a consequence, bactericidal effect after enzyme exposure remained, compared to pure LL-37 which was subjected to proteolysis. No skin irritation potential of the cubosomes was found, thus enabling for topical administration. The ex vivo wound infection model showed that LL-37 in pre-loaded cubosomes killed bacteria most efficient.
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| 3. |
- Alt Murphy, Margit, 1970, et al.
(författare)
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Acceleration based Activity Levels during Subacute Inpatient Stroke Rehabilitation
- 2017
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Ingår i: Procedia Technology. - : Elsevier BV. - 2212-0173. ; 27, s. 120-121
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Tidskriftsartikel (refereegranskat)abstract
- People after stroke have difficulties to reach sufficient physical activity level during their rehabilitation and particularly outside the therapy time. We aim to quantify activity levels and investigate differences in motor activity in weekdays and weekends in a subacute stage after stroke. Data from multiple three-axis accelerometers was collected during two 48h sessions in 11 patients. The activity level and symmetry indices were sensitive to variations in weekend and weekdays. This information is valuable in rehabilitation planning and management and enables identification of those in risk of low physical activity and inactivity. (C) 2017 The Authors. Published by Elsevier
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| 4. |
- Alt Murphy, Margit, 1970, et al.
(författare)
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Acceleration based activity metrics during subacute inpatient stroke rehabilitation
- 2016
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Ingår i: Procedia Technology, Biosensors 2016, 25-27 May, Göteborg, Sweden..
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- People after stroke have difficulties to reach sufficient physical activity level during their rehabilitation and particularly outside the therapy time. We aim to quantify activity levels and investigate differences in motor activity in weekdays and weekends in a subacute stage after stroke. Data from multiple three-axis accelerometers was collected during two 48h sessions in 11 patients. The activity level and symmetry indices were sensitive to variations in weekend and weekdays. This information is valuable in rehabilitation planning and management and enables identification of those in risk of low physical activity and inactivity.
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| 5. |
- Alt Murphy, Margit, 1970, et al.
(författare)
-
Comparison of Accelerometer-Based Arm, Leg and Trunk Activity at Weekdays and Weekends During Subacute Inpatient Rehabilitation After Stroke
- 2019
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Ingår i: Journal of Rehabilitation Medicine. - : Medical Journals Sweden AB. - 1650-1977 .- 1651-2081. ; 51:6, s. 426-433
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To determine whether there are differences in arm, leg and trunk activity measured by acceleration between weekdays and weekends in people undergoing rehabilitation in the subacute stage after stroke. Patients: Twenty-eight individuals with stroke (mean age 55.4 years; severe to mild impairment) and 10 healthy controls. Methods: A set of 5 3-axial accelerometers were used on the trunk, wrists and ankles during 2 48-h sessions at weekdays and over a weekend. Day-time acceleration raw data were expressed as the signal magnitude area. Asymmetry between the affected and less-affected limb was calculated as a ratio. Results: Participants with stroke used their both arms and legs less at weekends than on weekdays (p<0.05, effect size 0.3 2-0.5 7). Asymmetry between the affected and less-affected arm was greater at weekends (p < 0.05, effect size 0.32). All activity measures, apart from the less-affected arm on weekdays, were lower in stroke compared with controls (p<0.05, effect size 0.4-0.8). No statistically significant differences were detected between weekday and weekend activity for the control group. One-third of participants perceived the trunk sensor as inconvenient to wear. Conclusion: Increased focus needs to be applied on activities carried out during weekends at rehabilitation wards.
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| 6. |
- Andersson, Johanna K., et al.
(författare)
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Inter-Rater Agreement for Diagnosing Adenomyosis Using Magnetic Resonance Imaging and Transvaginal Ultrasonography
- 2023
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Ingår i: Diagnostics. - 2075-4418. ; 13:13
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Tidskriftsartikel (refereegranskat)abstract
- Our aim was to compare the inter-rater agreement about transvaginal ultrasonography (TVS) with magnetic resonance imaging (MRI) with regard to diagnosing adenomyosis and for assessing various predefined imaging features of adenomyosis, in the same set of women. The study cohort included 51 women, prospectively, consecutively recruited based on a clinical suspicion of adenomyosis. MRIs and TVS videoclips and 3D volumes were retrospectively assessed by four experienced radiologists and five experienced sonographers, respectively. Each rater subjectively evaluated the presence or absence of adenomyosis, as well as imaging features suggestive of adenomyosis. Fleiss kappa (κ) was used to reflect inter-rater agreement for categorical data, and the intraclass correlation coefficient (ICC) was used to reflect the reliability of quantitative data. Agreement between raters for diagnosing adenomyosis was higher for TVS than for MRI (κ = 0.42 vs. 0.28). MRI had a higher inter-rater agreement in assessing wall asymmetry, irregular junctional zone (JZ), and the presence of myometrial cysts, while TVU had a better agreement for assessing globular shape. MRI showed a moderate to good reliability for measuring the JZ (ICC = 0.57–0.82). For TVS, the JZ was unmeasurable in >50% of cases, and the remaining cases had low reliability (ICC = −0.31–0.08). We found that inter-rater agreement for diagnosing adenomyosis was higher for TVS than for MRI, despite the fact that MRI showed a higher inter-rater agreement in most specific features. Measurements of JZ in the coronal plane with 3D TVS were unreliable and thus unlikely to be useful for diagnosing adenomyosis.
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| 7. |
- Andersson, Sofi A., 1970, et al.
(författare)
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Arm impairment and walking speed explain real-life activity of the affected Arm and leg after stroke
- 2021
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Ingår i: Journal of Rehabilitation Medicine. - : Foundation for Rehabilitation Information. - 1650-1977 .- 1651-2081. ; 53:6
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To determine to what extent accelerometer-based arm, leg and trunk activity is associated with sensorimotor impairments, walking capacity and other factors in subacute stroke. Design: Cross-sectional study. Patients: Twenty-six individuals with stroke (mean age 55.4 years, severe to mild motor impairment). Methods: Data on daytime activity were collected over a period of 4 days from accelerometers placed on the wrists, ankles and trunk. A forward stepwise linear regression was used to determine associations between free-living activity, clinical and demographic variables. Results: Arm motor impairment (Fugl-Meyer Assessment) and walking speed explained more than 60% of the variance in daytime activity of the more-affected arm, while walking speed alone explained 60% of the more-affected leg activity. Activity of the less-affected arm and leg was associated with arm motor impairment (R2=0.40) and independence in walking (R2=0.59). Arm activity ratio was associated with arm impairment (R2=0.63) and leg activity ratio with leg impairment (R2=0.38) and walking speed (R2=0.27). Walking-related variables explained approximately 30% of the variance in trunk activity. Conclusion: Accelerometer-based free-living activity is dependent on motor impairment and walking capacity. The most relevant activity data were obtained from more-affected limbs. Motor impairment and walking speed can provide some information about real-life daytime activity levels.
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| 8. |
- Barnes, Brian R, et al.
(författare)
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The 5'-AMP-activated protein kinase gamma3 isoform has a key role in carbohydrate and lipid metabolism in glycolytic skeletal muscle
- 2004
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Ingår i: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 279:37, s. 38441-38447
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Tidskriftsartikel (refereegranskat)abstract
- 5'-AMP-activated protein kinase (AMPK) is a metabolic stress sensor present in all eukaryotes. A dominant missense mutation (R225Q) in pig PRKAG3, encoding the muscle-specific gamma3 isoform, causes a marked increase in glycogen content. To determine the functional role of the AMPK gamma3 isoform, we generated transgenic mice with skeletal muscle-specific expression of wild type or mutant (225Q) mouse gamma3 as well as Prkag3 knockout mice. Glycogen resynthesis after exercise was impaired in AMPK gamma3 knock-out mice and markedly enhanced in transgenic mutant mice. An AMPK activator failed to increase skeletal muscle glucose uptake in AMPK gamma3 knock-out mice, whereas contraction effects were preserved. When placed on a high fat diet, transgenic mutant mice but not knock-out mice were protected against excessive triglyceride accumulation and insulin resistance in skeletal muscle. Transfection experiments reveal the R225Q mutation is associated with higher basal AMPK activity and diminished AMP dependence. Our results validate the muscle-specific AMPK gamma3 isoform as a therapeutic target for prevention and treatment of insulin resistance.
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| 9. |
- Caputo, Mara, et al.
(författare)
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Genetic Ablation of STE20-Type Kinase MST4 Does Not Alleviate Diet-Induced MASLD Susceptibility in Mice
- 2024
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Ingår i: INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES. - 1661-6596 .- 1422-0067. ; 25:4
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Tidskriftsartikel (refereegranskat)abstract
- Metabolic dysfunction-associated steatotic liver disease (MASLD) and its advanced subtype, metabolic dysfunction-associated steatohepatitis (MASH), have emerged as the most common chronic liver disease worldwide, yet there is no targeted pharmacotherapy presently available. This study aimed to investigate the possible in vivo function of STE20-type protein kinase MST4, which was earlier implicated in the regulation of hepatocellular lipotoxic milieu in vitro, in the control of the diet-induced impairment of systemic glucose and insulin homeostasis as well as MASLD susceptibility. Whole-body and liver-specific Mst4 knockout mice were generated by crossbreeding conditional Mst4fl/fl mice with mice expressing Cre recombinase under the Sox2 or Alb promoters, respectively. To replicate the environment in high-risk subjects, Mst4-/- mice and their wild-type littermates were fed a high-fat or a methionine-choline-deficient (MCD) diet. Different in vivo tests were conducted in obese mice to describe the whole-body metabolism. MASLD progression in the liver and lipotoxic damage to adipose tissue, kidney, and skeletal muscle were analyzed by histological and immunofluorescence analysis, biochemical assays, and protein and gene expression profiling. In parallel, intracellular fat storage and oxidative stress were assessed in primary mouse hepatocytes, where MST4 was silenced by small interfering RNA. We found that global MST4 depletion had no effect on body weight or composition, locomotor activity, whole-body glucose tolerance or insulin sensitivity in obese mice. Furthermore, we observed no alterations in lipotoxic injuries to the liver, adipose, kidney, or skeletal muscle tissue in high-fat diet-fed whole-body Mst4-/- vs. wild-type mice. Liver-specific Mst4-/- mice and wild-type littermates displayed a similar severity of MASLD when subjected to an MCD diet, as evidenced by equal levels of steatosis, inflammation, hepatic stellate cell activation, fibrosis, oxidative/ER stress, and apoptosis in the liver. In contrast, the in vitro silencing of MST4 effectively protected primary mouse hepatocytes against ectopic lipid accumulation and oxidative cell injury triggered by exposure to fatty acids. In summary, these results suggest that the genetic ablation of MST4 in mice does not mitigate the initiation or progression of MASLD and has no effect on systemic glucose or insulin homeostasis in the context of nutritional stress. The functional compensation for the genetic loss of MST4 by yet undefined mechanisms may contribute to the apparent discrepancy between in vivo and in vitro phenotypic consequences of MST4 silencing.
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| 10. |
- Caputo, Mara, et al.
(författare)
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STE20-type kinases MST3 and MST4 promote the progression of hepatocellular carcinoma: Evidence from human cell culture and expression profiling of liver biopsies
- 2023
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Ingår i: Faseb Journal. - 0892-6638. ; 37:8
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Tidskriftsartikel (refereegranskat)abstract
- Hepatocellular carcinoma (HCC) is one of the most fatal and fastest growing malignancies. Recently, nonalcoholic steatohepatitis (NASH), characterized by liver steatosis, inflammation, cell injury (hepatocyte ballooning), and different stages of fibrosis, has emerged as a major catalyst for HCC. Because the STE20-type kinases, MST3 and MST4, have been described as critical molecular regulators of NASH pathophysiology, we here focused on determining the relevance of these proteins in human HCC. By analyzing public datasets and in-house cohorts, we found that hepatic MST3 and MST4 expression was positively correlated with the incidence and severity of HCC. We also found that the silencing of both MST3 and MST4, but also either of them individually, markedly suppressed the tumorigenesis of human HCC cells including attenuated proliferation, migration, invasion, and epithelial-mesenchymal transition. Mechanistic investigations revealed lower activation of STAT3 signaling in MST3/MST4-deficient hepatocytes and identified GOLGA2 and STRIPAK complex as the binding partners of both MST3 and MST4. These findings reveal that MST3 and MST4 play a critical role in promoting the progression of HCC and suggest that targeting these kinases may provide a novel strategy for the treatment of liver cancer.
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| 11. |
- Chen, Heyin, et al.
(författare)
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Investigating Surface Reactivity of a Ni-Rich Cathode Material toward CO2, H2O, and O2 Using Ambient Pressure X-ray Photoelectron Spectroscopy
- 2023
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Ingår i: ACS Applied Energy Materials. - : American Chemical Society (ACS). - 2574-0962. ; 6:22, s. 11458-11467
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Tidskriftsartikel (refereegranskat)abstract
- Layered Ni-rich transition metal oxide materials are considered the most promising cathodes for use in commercial Li-ion batteries. Due to their instability in air, an impurity layer forms during storage under ambient conditions, and this layer increases electrochemical polarization during charging and discharging, which ultimately leads to a lower cycling capacity. In this work, we found that storage of the LiNi0.8Mn0.1Co0.1O2 (NMC 811) material in ultrahigh vacuum (UHV) can restore the surface by reducing the amount of native carbonate species in the impurity layer. In this work, in situ soft X-ray ambient pressure photoelectron spectroscopy is used to directly follow the interaction between common gases found in air and the NMC 811 surface. During gas exposure of the NMC 811 surface to pure CO2, O2, and a mixture of both pure gases, surface-adsorbed CO2 or/and O2 were detected; however, permanent changes could not be identified under UHV after the gas exposure. In contrast, a permanent increase in metal hydroxide species was observed on the sample surface following H2O vapor exposure, and an increased intensity in the carboxylate peak was observed after exposure to a mixture of CO2/O2/H2O. Thus, the irreversible degradation reaction with CO2 is triggered in the presence of H2O (on relevant time scales defined by the experiment). Additional measurements revealed that X-ray irradiation induces the formation of metal carbonate species on the NMC 811 surface under CO2 and H2O vapor pressure.
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| 12. |
- Håkansson, Joakim, et al.
(författare)
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Characterization of the in vitro, ex vivo, and in vivo Efficacy of the Antimicrobial Peptide DPK-060 Used for Topical Treatment
- 2019
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Ingår i: Frontiers in Cellular and Infection Microbiology. - : Frontiers Media SA. - 2235-2988. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Antimicrobial peptides, also known as host defense peptides, have recently emerged as a promising new category of therapeutic agents for the treatment of infectious diseases. This study evaluated the preclinical in vitro, ex vivo, and in vivo antimicrobial activity, as well as the potential to cause skin irritation, of human kininogen-derived antimicrobial peptide DPK-060 in different formulations designed for topical delivery. We found that DPK-060 formulated in acetate buffer or poloxamer gel caused a marked reduction of bacterial counts of Staphylococcus aureus in vitro (minimum microbicidal concentration <5 μg/ml). We also found that DPK-060 in poloxamer gel significantly suppressed microbial survival in an ex vivo wound infection model using pig skin and in an in vivo mouse model of surgical site infection (≥99 or ≥94% reduction in bacterial counts was achieved with 1% DPK-060 at 4 h post-treatment, respectively). Encapsulation of DPK-060 in different types of lipid nanocapsules or cubosomes did not improve the bactericidal potential of the peptide under the applied test conditions. No reduction in cell viability was observed in response to administration of DPK-060 in any of the formulations tested. In conclusion, the present study confirms that DPK-060 has the potential to be an effective and safe drug candidate for the topical treatment of microbial infections; however, adsorption of the peptide to nanocarriers failed to show any additional benefits.
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| 13. |
- Kokkonen, Esko, et al.
(författare)
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Upgrade of the SPECIES beamline at the MAX IV Laboratory
- 2021
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Ingår i: Journal of Synchrotron Radiation. - 1600-5775. ; 28, s. 588-601
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Tidskriftsartikel (refereegranskat)abstract
- The SPECIES beamline has been transferred to the new 1.5 GeV storage ring at the MAX IV Laboratory. Several improvements have been made to the beamline and its endstations during the transfer. Together the Ambient Pressure X-ray Photoelectron Spectroscopy and Resonant Inelastic X-ray Scattering endstations are capable of conducting photoelectron spectroscopy in elevated pressure regimes with enhanced time-resolution and flux and X-ray scattering experiments with improved resolution and flux. Both endstations offer a unique capability for experiments at low photon energies in the vacuum ultraviolet and soft X-ray range. In this paper, the upgrades on the endstations and current performance of the beamline are reported.
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| 14. |
- Kumar Anand, Sumit, et al.
(författare)
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Inhibition of MAP4K4 signaling initiates metabolic reprogramming to protect hepatocytes from lipotoxic damage
- 2022
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Ingår i: Journal of Lipid Research. - : Elsevier BV. - 0022-2275. ; 63:7
-
Tidskriftsartikel (refereegranskat)abstract
- The primary hepatic consequence of obesity is non-alcoholic fatty liver disease (NAFLD), affecting about 25% of the global adult population. Non-alcoholic steatohepatitis (NASH) is a severe form of NAFLD characterized by liver lipid accumulation, inflammation, and hepatocyte ballooning, with a different degree of hepatic fibrosis. In the light of rapidly increasing prevalence of NAFLD and NASH, there is an urgent need for improved understanding of the molecular pathogenesis of these diseases. The aim of this study was to decipher the possible role of STE20-type kinase MAP4K4 in the regulation of he-patocellular lipotoxicity and susceptibility to NAFLD. We found that MAP4K4 mRNA expression in human liver biopsies was positively correlated with key hallmarks of NAFLD (i.e., liver steatosis, lobular inflammation, hepatocellular ballooning, and fibrosis). We also found that the silencing of MAP4K4 suppressed lipid deposition in human he-patocytes by stimulating beta-oxidation and tri-acylglycerol secretion, while attenuating fatty acid influx and lipid synthesis. Furthermore, down -regulation of MAP4K4 markedly reduced the glycolysis rate and lowered incidences of oxidative/ endoplasmic reticulum stress. In parallel, we observed suppressed JNK and ERK and increased AKT phosphorylation in MAP4K4-deficient hep-atocytes. Together, these results provide the first experimental evidence supporting the potential involvement of STE20-type kinase MAP4K4 as a component of the hepatocellular lipotoxic milieu promoting NAFLD susceptibility.
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| 15. |
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| 16. |
- Maibach, Julia, et al.
(författare)
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Probing a battery electrolyte drop with ambient pressure photoelectron spectroscopy
- 2019
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Ingår i: Nature Communications. - : NATURE PUBLISHING GROUP. - 2041-1723. ; 10
-
Tidskriftsartikel (refereegranskat)abstract
- Operando ambient pressure photoelectron spectroscopy in realistic battery environments is a key development towards probing the functionality of the electrode/electrolyte interface in lithium-ion batteries that is not possible with conventional photoelectron spectroscopy. Here, we present the ambient pressure photoelectron spectroscopy characterization of a model electrolyte based on 1M bis(trifluoromethane)sulfonimide lithium salt in propylene carbonate. For the first time, we show ambient pressure photoelectron spectroscopy data of propylene carbonate in the liquid phase by using solvent vapor as the stabilizing environment. This enables us to separate effects from salt and solvent, and to characterize changes in electrolyte composition as a function of probing depth. While the bulk electrolyte meets the expected composition, clear accumulation of ionic species is found at the electrolyte surface. Our results show that it is possible to measure directly complex liquids such as battery electrolytes, which is an important accomplishment towards true operando studies.
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| 17. |
- Nerstedt, Annika, 1960, et al.
(författare)
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AMP-activated protein kinase inhibits IL-6-stimulated inflammatory response in human liver cells by suppressing phosphorylation of signal transducer and activator of transcription 3 (STAT3)
- 2010
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Ingår i: Diabetologia. - 0012-186X. ; 53:11, s. 2406-2416
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Tidskriftsartikel (refereegranskat)abstract
- AIM/HYPOTHESIS: The aim of the study was to examine the possible role of AMP-activated protein kinase (AMPK) in the regulation of the inflammatory response induced by cytokine action in human liver cells. METHODS: IL-6-stimulated expression of the genes for acute-phase response markers serum amyloid A (SAA1, SAA2) and haptoglobin (HP) in the human hepatocarcinoma cell line HepG2 were quantified after modulation of AMPK activity by pharmacological agonists (5-amino-4-imidazole-carboxamideriboside [AICAR], metformin) or by using small interfering (si) RNA transfection. The intracellular signalling pathway mediating the effect of AMPK on IL-6-stimulated acute-phase marker expression was characterised by assessing the phosphorylation levels of the candidate protein signal transducer and activator of transcription 3 (STAT3) in response to AMPK agonists. RESULTS: AICAR and metformin markedly blunt the IL-6-stimulated expression of SAA cluster genes as well as of haptoglobin in a dose-dependent manner. Moreover, the repression of AMPK activity by siRNA significantly reversed the inhibition of SAA expression by both AICAR and metformin, indicating that the effect of the agonists is dependent on AMPK. For the first time we show that AMPK appears to regulate IL-6 signalling by directly inhibiting the activation of the main downstream target of IL-6, STAT3. CONCLUSIONS/INTERPRETATION: We provide evidence for a key function of AMPK in suppression of the acute-phase response caused by the action of IL-6 in liver, suggesting that AMPK may act as an intracellular link between chronic low-grade inflammation and metabolic regulation in peripheral metabolic tissues.
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| 18. |
- Nerstedt, Annika, 1960, et al.
(författare)
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Serine/threonine protein kinase 25 (STK25): a novel negative regulator of lipid and glucose metabolism in rodent and human skeletal muscle
- 2012
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Ingår i: Diabetologia. - : Springer Science and Business Media LLC. - 0012-186X .- 1432-0428. ; 55:6, s. 1797-1807
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Tidskriftsartikel (refereegranskat)abstract
- This study investigates the role of serine/threonine protein kinase 25 (STK25), a member of the sterile 20 (STE20) superfamily of kinases, in the regulation of skeletal muscle metabolism. The effect of depleting STK25 in muscle cells was studied by reducing the mRNA and protein content of this target in the rat myoblast cell line L6 by small interfering (si)RNA. The changes in the mRNA and protein levels of several members of the fatty acid oxidative and glucose metabolic pathways were measured by quantitative real-time (qRT)-PCR and western blot. The rate of palmitate oxidation and glucose uptake was measured after transfection with siRNA for . Expression of was also evaluated in skeletal muscle biopsies from 41 white Europid men and women with normal and impaired glucose tolerance and type 2 diabetes using qRT-PCR. We demonstrate that partial depletion of STK25 increases the expression of uncoupling protein 3 (, accompanied by increased lipid oxidation, in myoblasts. In addition, a reduced level of STK25 enhances the expression of (also known as ), (also known as ) and hexokinase 2, and correspondingly, improves insulin-stimulated glucose uptake in muscle cells. Consistent with these results, significantly higher levels were observed in the skeletal muscle of type 2 diabetic patients, compared with individuals with normal glucose tolerance. This is the first study indicating a possible role for STK25 in the regulation of glucose and lipid metabolism in L6 myoblasts. This kinase appears to be an interesting new mediator to be evaluated for therapeutic intervention in type 2 diabetes and related complications, as controlled increase in lipid oxidation and insulin-stimulated glucose uptake in skeletal muscle is favourable and can restore energy balance in metabolically compromised states.
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| 19. |
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| 20. |
- Schnadt, Joachim, et al.
(författare)
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Experimental evidence for sub-3-fs charge transfer from an aromatic adsorbate to a semiconductor
- 2002
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 418:6898, s. 620-623
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Tidskriftsartikel (refereegranskat)abstract
- The ultrafast timescale of electron transfer processes is crucial to their role in many biological systems and technological devices. In dye-sensitized solar cells(1-4), the electron transfer from photoexcited dye molecules to nanostructured semiconductor substrates needs to be sufficiently fast to compete effectively against loss processes and thus achieve high solar energy conversion efficiencies(4). Time-resolved laser techniques indicate an upper limit of 20 to 100 femtoseconds(5-9) for the time needed to inject an electron from a dye into a semiconductor, which corresponds to the timescale on which competing processes such as charge redistribution(10,11) and intramolecular thermalization of excited states(12-14) occur. Here we use resonant photoemission spectroscopy, which has previously been used to monitor electron transfer in simple systems with an order-of-magnitude improvement in time resolution(15,16), to show that electron transfer from an aromatic adsorbate to a TiO2 semiconductor surface can occur in less than 3 fs. These results directly confirm that electronic coupling of the aromatic molecule to its substrate is sufficiently strong to suppress competing processes(17).
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| 21. |
- Urpelainen, Samuli, et al.
(författare)
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The SPECIES beamline at the MAX IV Laboratory : A facility for soft X-ray RIXS and APXPS
- 2017
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Ingår i: Journal of Synchrotron Radiation. - 1600-5775 .- 0909-0495. ; 24:1, s. 344-353
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Tidskriftsartikel (refereegranskat)abstract
- SPECIES is an undulator-based soft X-ray beamline that replaced the old I511 beamline at the MAX II storage ring. SPECIES is aimed at high-resolution ambient-pressure X-ray photoelectron spectroscopy (APXPS), near-edge X-ray absorption fine-structure (NEXAFS), X-ray emission spectroscopy (XES) and resonant inelastic X-ray scattering (RIXS) experiments. The beamline has two branches that use a common elliptically polarizing undulator and monochromator. The beam is switched between the two branches by changing the focusing optics after the monochromator. Both branches have separate exit slits, refocusing optics and dedicated permanent endstations. This allows very fast switching between two types of experiments and offers a unique combination of the surface-sensitive XPS and bulk-sensitive RIXS techniques both in UHV and at elevated ambient-pressure conditions on a single beamline. Another unique property of the beamline is that it reaches energies down to approximately 27 eV, which is not obtainable on other current APXPS beamlines. This allows, for instance, valence band studies under ambient-pressure conditions. In this article the main properties and performance of the beamline are presented, together with selected showcase experiments performed on the new setup.
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| 22. |
- Westas, Mats, et al.
(författare)
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The experience of participating in an internet-based cognitive behavioral therapy program among patients with cardiovascular disease and depression : a qualitative interview study
- 2022
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Ingår i: BMC Psychiatry. - London, United Kingdom : BioMed Central (BMC). - 1471-244X. ; 22:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Depression in conjunction with cardiovascular disease (CVD) is associated with worsening in CVD, higher mortality, and poorer quality of life. Despite the poor outcomes there is a treatment gap of depression in CVD patients. Recently we found that an Internet-based cognitive behavioral therapy (iCBT) tailored for CVD patients led to reduced symptoms of depression. However, we still have little knowledge about CVD patients’ experiences of working with iCBT. The aim of this study was therefore to explore CVD patients’ experiences of engaging in a tailored iCBT program. Methods: A qualitative interview study using inductive thematic analysis. Data was obtained from 20 patients with CVD and depressive symptoms who had participated in a randomized controlled trial (RCT) evaluating the impact of a nine-week iCBT program on depression. Results: Three main themes emerged: (1) Taking control of the disease, (2) Not just a walk in the park, and (3) Feeling a personal engagement with the iCBT program. The first theme included comments that the tailored program gave the patients a feeling of being active in the treatment process and helped them achieve changes in thoughts and behaviors necessary to take control of their CVD. The second theme showed that patients also experienced the program as demanding and emotionally challenging. However, it was viewed as helpful to challenge negative thinking about living with CVD and to change depressive thoughts. In the third theme patients reported that the structure inherent in the program, in the form of organizing their own health and the scheduled feedback from the therapist created a feeling of being seen as an individual. The feeling of being acknowledged as a person also made it easier to continuously work with the changes necessary to improve their health. Conclusions: Engaging in an iCBT program tailored for patients with CVD and depression was by the patients perceived as helpful in the treatment of depression. They experienced positive changes in emotions, thoughts, and behaviors which a result of learning to take control of their CVD, being confirmed and getting support. The patients considered working with the iCBT program as demanding and emotionally challenging, but necessary to achieve changes in emotions, thoughts, and behaviors.
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- Xia, Ying, et al.
(författare)
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Knockout of STE20-type kinase TAOK3 does not attenuate diet-induced NAFLD development in mice
- 2023
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Ingår i: Molecular Medicine. - 1076-1551. ; 29:1
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Tidskriftsartikel (refereegranskat)abstract
- ObjectiveNon-alcoholic fatty liver disease (NAFLD), the primary hepatic consequence of obesity, is affecting about 25% of the global adult population. The aim of this study was to examine the in vivo role of STE20-type protein kinase TAOK3, which has been previously reported to regulate hepatocellular lipotoxicity in vitro, in the development of NAFLD and systemic insulin resistance in the context of obesity.MethodsTaok3 knockout mice and wild-type littermates were challenged with a high-fat diet. Various in vivo tests were performed to characterize the whole-body metabolism. NAFLD progression in the liver, and lipotoxic damage in adipose tissue, kidney, and skeletal muscle were compared between the genotypes by histological assessment, immunofluorescence microscopy, protein and gene expression profiling, and biochemical assays. Intracellular lipid accumulation and oxidative/ER stress were analyzed in cultured human and mouse hepatocytes where TAOK3 was knocked down by small interfering RNA. The expression of TAOK3-related STE20-type kinases was quantified in different organs from high-fat diet-fed Taok3-/- and wild-type mice.ResultsTAOK3 deficiency had no impact on body weight or composition, food consumption, locomotor activity, or systemic glucose or insulin homeostasis in obese mice. Consistently, Taok3-/- mice and wild-type littermates developed a similar degree of high-fat diet-induced liver steatosis, inflammation, and fibrosis, and we detected no difference in lipotoxic damage of adipose tissue, kidney, or skeletal muscle when comparing the two genotypes. In contrast, the silencing of TAOK3 in vitro markedly suppressed ectopic lipid accumulation and metabolic stress in mouse and human hepatocytes. Interestingly, the hepatic mRNA abundance of several TAOK3-related kinases, which have been previously implicated to increase the risk of NAFLD susceptibility, was significantly elevated in Taok3-/-vs. wild-type mice.ConclusionsIn contrast to the in vitro observations, genetic deficiency of TAOK3 in mice failed to mitigate the detrimental metabolic consequences of chronic exposure to dietary lipids, which may be partly attributable to the activation of liver-specific compensation response for the genetic loss of TAOK3 by related STE20-type kinases.
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| 25. |
- Xia, Ying, et al.
(författare)
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Silencing of STE20-type kinase TAOK1 confers protection against hepatocellular lipotoxicity through metabolic rewiring
- 2023
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Ingår i: Hepatology communications.. - : Ovid Technologies (Wolters Kluwer Health). - 2471-254X. ; 7:4
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Tidskriftsartikel (refereegranskat)abstract
- Background: NAFLD has become the leading cause of chronic liver disease worldwide afflicting about one quarter of the adult population. NASH is a severe subtype of NAFLD, which in addition to hepatic steatosis connotes liver inflammation and hepatocyte ballooning. In light of the exponentially increasing prevalence of NAFLD, it is imperative to gain a better understanding of its molecular pathogenesis. The aim of this study was to examine the potential role of STE20-type kinase TAOK1 -a hepatocellular lipid droplet-associated protein-in the regulation of liver lipotoxicity and NAFLD etiology. Methods: The correlation between TAOK1 mRNA expression in liver biopsies and the severity of NAFLD was evaluated in a cohort of 62 participants. Immunofluorescence microscopy was applied to describe the subcellular localization of TAOK1 in human and mouse hepatocytes. Metabolic reprogramming and oxidative/endoplasmic reticulum stress were investigated in immortalized human hepatocytes, where TAOK1 was overexpressed or silenced by small interfering RNA, using functional assays, immunofluorescence microscopy, and colorimetric analysis. Migration, invasion, and epithelial-mesenchymal transition were examined in TAOK1-deficient human hepatoma-derived cells. Alterations in hepatocellular metabolic and pro-oncogenic signaling pathways were assessed by immunoblotting. Results: We observed a positive correlation between the TAOK1 mRNA abundance in human liver biopsies and key hallmarks of NAFLD (i.e., hepatic steatosis, inflammation, and ballooning). Furthermore, we found that TAOK1 protein fully colocalized with intracellular lipid droplets in human and mouse hepatocytes. The silencing of TAOK1 alleviated lipotoxicity in cultured human hepatocytes by accelerating lipid catabolism (mitochondrial beta-oxidation and triacylglycerol secretion), suppressing lipid anabolism (fatty acid influx and lipogenesis), and mitigating oxidative/endoplasmic reticulum stress, and the opposite changes were detected in TAOK1-overexpressing cells. We also found decreased proliferative, migratory, and invasive capacity, as well as lower epithelial-mesenchymal transition in TAOK1-deficient human hepatoma-derived cells. Mechanistic studies revealed that TAOK1 knockdown inhibited ERK and JNK activation and repressed acetyl-CoA carboxylase (ACC) protein abundance in human hepatocytes. Conclusions: Together, we provide the first experimental evidence supporting the role of hepatic lipid droplet-decorating kinase TAOK1 in NAFLD development through mediating fatty acid partitioning between anabolic and catabolic pathways, regulating oxidative/endoplasmic reticulum stress, and modulating metabolic and pro-oncogenic signaling.
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