| 1. |
- Bayrak Pehlivan, Ilknur, et al.
(författare)
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NiMoV and NiO-based catalysts for efficient solar-driven water splitting using thermally integrated photovoltaics in a scalable approach
- 2021
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Ingår i: iScience. - : Cell Press. - 2589-0042. ; 24:1
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Tidskriftsartikel (refereegranskat)abstract
- In this work, a trimetallic NiMoV catalyst is developed for the hydrogen evolution reaction and characterized with respect to structure, valence, and elemental distribution. The overpotential to drive a 10 mA cm−2 current density is lowered from 94 to 78 mV versus reversible hydrogen electrode by introducing V into NiMo. A scalable stand-alone system for solar-driven water splitting was examined for a laboratory-scale device with 1.6 cm2 photovoltaic (PV) module area to an up-scaled device with 100 cm2 area. The NiMoV cathodic catalyst is combined with a NiO anode in alkaline electrolyzer unit thermally connected to synthesized (Ag,Cu) (In,Ga)Se2 ((A)CIGS) PV modules. Performance of 3- and 4-cell interconnected PV modules, electrolyzer, and hydrogen production of the PV electrolyzer are examined between 25°C and 50°C. The PV-electrolysis device having a 4-cell (A)CIGS under 100 mW cm−2 illumination and NiMoV-NiO electrolyzer shows 9.1% maximum and 8.5% averaged efficiency for 100 h operation.
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| 2. |
- Calnan, Sonya, et al.
(författare)
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Development of Various Photovoltaic‐Driven Water Electrolysis Technologies for Green Solar Hydrogen Generation
- 2021
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Ingår i: Solar RRL. - : John Wiley & Sons. - 2367-198X. ; 6:5
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Tidskriftsartikel (refereegranskat)abstract
- Direct solar hydrogen generation via a combination of photovoltaics (PV) and water electrolysis can potentially ensure a sustainable energy supply while minimizing greenhouse emissions. The PECSYS project aims at demonstrating asolar-driven electrochemical hydrogen generation system with an area >10 m2 with high efficiency and at reasonable cost. Thermally integrated PV electrolyzers(ECs) using thin-film silicon, undoped, and silver-doped Cu(In,Ga)Se2 and silicon heterojunction PV combined with alkaline electrolysis to form one unit are developed on a prototype level with solar collection areas in the range from 64 to2600 cm2 with the solar-to-hydrogen (StH) efficiency ranging from 4 to 13%. Electrical direct coupling of PV modules to a proton exchange membrane EC test the effects of bifacially (730 cm2 solar collection area) and to study the long-term operation under outdoor conditions (10 m2 collection area) is also investigated. In both cases, StH efficiencies exceeding 10% can be maintained over the test periods used. All the StH efficiencies reported are based on measured gas outflow using mass flow meters.
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| 3. |
- Movérare-Skrtic, Sofia, et al.
(författare)
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Dihydrotestosterone treatment results in obesity and altered lipid metabolism in orchidectomized mice.
- 2006
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Ingår i: Obesity (Silver Spring, Md.). - : Wiley. - 1930-7381 .- 1930-739X. ; 14:4, s. 662-72
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To determine the role of androgen receptor (AR) activation for adipose tissue metabolism. Sex steroids are important regulators of adipose tissue metabolism in men. Androgens may regulate the adipose tissue metabolism in men either directly by stimulation of the AR or indirectly by aromatization of androgens into estrogens and, thereafter, by stimulation of the estrogen receptors. Previous studies have shown that estrogen receptor alpha stimulation results in reduced fat mass in men. RESEARCH METHODS AND PROCEDURES: Orchidectomized mice were treated with the non-aromatizable androgen 5alpha-dihydrotestosterone (DHT), 17beta-estradiol, or vehicle. Vo(2), Vco(2), resting metabolic rate, locomotor activity, and food consumption were measured. Furthermore, changes in hepatic gene expression were analyzed. RESULTS: DHT treatment resulted in obesity, associated with reduced energy expenditure and fat oxidation. In contrast, DHT did not affect food consumption or locomotor activity. Furthermore, DHT treatment resulted in increased high-density lipoprotein-cholesterol and triglyceride levels associated with markedly decreased 7alpha-hydroxylase gene expression, indicating decreased bile acid production. DISCUSSION: We showed that AR activation results in obesity and altered lipid metabolism in orchidectomized mice. One may speculate that AR antagonists might be useful in the treatment of obesity in men.
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| 4. |
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| 6. |
- Oscarsson, Johan, 1970
(författare)
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Dynamic Train-Track Interaction: Linear and Non-Linear Track Models with Property Scatter
- 2001
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- A numerical method was developed to investigate the vertical dynamic behaviour of a railway track subjected to the loading of a moving train. The numerical simulations are carried out in the time-domain with what is known as a moving mass model. This doctoral thesis emphasises especially the influence on the train-track dynamics of the ballast mass (giving rise to inertia forces when a train passes), the influence of the non-linear characteristics of the railpad and of the sleeper support, and the part played by scatter in some track structure properties, such as varying railpad stiffness, varying ballast stiffness and varying sleeper spacing. Full-scale measurements in the field sometimes reveal a track resonance at low frequency (somewhere in the region of 20 to 150 Hz). This resonant behaviour cannot be modelled unless the ballast-subgrade inertia is included in the track model, which is done here. Both laboratory and full-scale field measurements have shown that the load deflection behaviour of the railpad and the sleeper support are non-linear. In a realistic demonstration example, the influence of a state dependent railpad on railpad compression and rail wear was investigated. It was shown that, for a weakly state dependent railpad, the difference in results compared with those obtained for a linear model is negligible. Measurements have also shown that track parameter values are not constant along the track. In fact, very dissimilar properties have been observed even between neighbouring sleepers. It is concluded that, if one wants to investigate the mean values and variations of selected track parameters, a method that does not restrict the variation and distribution of the stochastic variables is, while not necessary, certainly preferable.
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| 7. |
- Oscarsson, Nicklas, 1974, et al.
(författare)
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Radiation-induced cystitis treated with hyperbaric oxygen therapy (RICH-ART): a randomised, controlled, phase 2–3 trial
- 2019
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Ingår i: The Lancet Oncology. - 1470-2045 .- 1474-5488. ; 20:11, s. 1602-1614
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Tidskriftsartikel (refereegranskat)abstract
- © 2019 Elsevier Ltd Background: Late radiation cystitis is an adverse effect of cancer treatment with radiotherapy in the pelvic region. Symptoms of late radiation cystitis can be assessed with the Expanded Prostate Index Composite Score (EPIC). Previous reports indicate that hyperbaric oxygen therapy reduces symptoms from late radiation cystitis, but the evidence is predominantly based on non-randomised and retrospective studies. We aimed to assess whether hyperbaric oxygen therapy would mitigate symptoms of late radiation cystitis. Methods: We did a randomised, controlled, phase 2–3 trial (RICH-ART [Radiation Induced Cystitis treated with Hyperbaric oxygen—A Randomised controlled Trial]) at five Nordic university hospitals. All patients aged 18–80 years, with pelvic radiotherapy completed at least 6 months previously, a score of less than 80 in the urinary domain of the Expanded Prostate Index Composite Score (EPIC), and referred to participating hyperbaric clinics due to symptoms of late radiation cystitis, were eligible for inclusion. Exclusion criteria were ongoing bleeding requiring blood transfusion exceeding 500 mL in the past 4 weeks, permanent urinary catheter, bladder capacity less than 100 mL, fistula in the urinary bladder, previous treatment with hyperbaric oxygen therapy for late radiation injuries, and contraindications to hyperbaric oxygen therapy. After computer-generated 1:1 randomisation with block sizes of four for each stratification group (sex, time from radiotherapy to inclusion, and previous invasive surgery in the pelvic area), patients received hyperbaric oxygen therapy (30–40 sessions, 100% oxygen, breathed at a pressure of 240–250 kPa, for 80–90 min daily) or standard care with no restrictions for other medications or interventions. No masking was applied. The primary outcome was change in patient-perceived urinary symptoms assessed with EPIC from inclusion to follow-up at visit 4 (6–8 months later), measured as absolute change in EPIC urinary total score. RICH-ART closed enrolment on Dec 31, 2017; the last follow-up data will be compiled in 2023. RICH-ART is registered with ClinicalTrials.gov, number NCT01659723, and with the European Medicines Agency, number EudraCT 2012-001381-15. Findings: Of 223 patients screened between May 9, 2012, and Dec 20, 2017, 87 patients were enrolled and randomly assigned to either hyperbaric oxygen therapy (n=42) or standard care (n=45). After excluding eight patients who withdrew consent directly after randomisation (one in the hyperbaric oxygen therapy group and seven in the standard care group), 79 were included in the intention-to-treat analyses (n=41 in the hyperbaric oxygen therapy group, n=38 in the standard care group). Median time from randomisation to visit 4 was 234 days (IQR 210–262) in the hyperbaric oxygen therapy group and 217 days (195–237) in the standard care group. The difference between change in group mean of EPIC urinary total score at visit 4 was 10·1 points (95% CI 2·2–18·1; p=0·013; 17·8 points [SD 18·4] in the hyperbaric oxygen therapy group vs 7·7 points [15·5] in the standard care group). 17 (41%) of 41 patients in the hyperbaric oxygen therapy group experienced transient grade 1–2 adverse events, related to sight and hearing, during the period of hyperbaric oxygen therapy. Interpretation: Our results suggest that hyperbaric oxygen therapy relieves symptoms of late radiation cystitis. We conclude that hyperbaric oxygen therapy is a safe and well tolerated treatment. Funding: The regional research fund of Region Västra Götaland, Sweden, the regional Health Technology Assessment Centre at Sahlgrenska University Hospital, Sweden, and Lions Cancer Research Fund of Western Sweden.
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| 8. |
- Walser, Marion, 1961, et al.
(författare)
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Different modes of GH administration influence gene expression in the male rat brain
- 2014
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Ingår i: Journal of Endocrinology. - 0022-0795 .- 1479-6805. ; 222:2, s. 181-190
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Tidskriftsartikel (refereegranskat)abstract
- The endogenous secretion pattern in males of GH is episodic in rats and in humans, whereas GH administration is usually even. Different types of GH administration have different effects on body mass, longitudinal bone growth, and liver metabolism in rodents, whereas possible effects on brain plasticity have not been investigated. In this study, GH was administered as a continuous infusion or as two daily injections in hypophysectomized male rats. Thirteen transcripts previously known to respond to GH in the hippocampus and parietal cortex (cortex) were assessed by RT-PCR. To investigate the effects of type of GH administration on several transcripts with different variations, and categories of transcripts (neuron-, glia-, and GH-related), a mixed model analysis was applied. Accordingly, GH injections increased overall transcript abundance more than GH infusions (21% in the hippocampus, P<0.001 and 10% in the cortex, PZ0.09). Specifically, GH infusions and injections robustly increased neuronal hemoglobin beta (Hbb) expression significantly (1.8- to 3.6-fold), and GH injections were more effective than GH infusions in increasing Hbb in the cortex (41%, PZ0.02), whereas a 23% difference in the hippocampus was not significant. Also cortical connexin 43 was higher in the group with GH injections than in those with GH infusions (26%, P<0.007). Also, there were differences between GH injections and infusions in GH-related transcripts of the cortex (23%, PZ0.04) and glia-related transcripts of the hippocampus (15%, PZ0.02). Thus, with the exception of Hbb there is a moderate difference in responsiveness to different modes of GH administration. © 2014 Society for Endocrinology.
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| 9. |
- Walser, Marion, 1961, et al.
(författare)
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Effects of peripheral administration of GH and IGF-I on gene expression in the hippocampus of hypophysectomised rats
- 2018
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Ingår i: Neuroendocrinology Letters. - 0172-780X. ; 39:7, s. 525-531
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Growth hormone (GH) increases insulin-like growth factor I (IGF-I) production and both hormones affect hippocampal plasticity. We have previously shown that Hbb and Alas2 in the rat hippocampus were robustly regulated by GH-infusions for six days, whereas other transcripts were weakly affected. Here, weexplored the effects of prolonged GH administration on transcripts linked to neuroprotection and investigated whether serum IGF-I administration may exert similar effects. DESIGN: Hypophysectomised female rats were infused with GH or IGF-I for 19 days. Hbb, Alas2 and seven additional GH- and IGF-I-related transcripts were quantified by Q-RT-PCR in rat hippocampus. RESULTS: Three transcripts, Hbb, Alas2, and Aloxl5 were increased by both GH and IGF-I administration. The other transcripts were marginally affected. CONCLUSION: The 19-day GH-infusion induced similar effects as those reported after 6-day GH treatment, with the addition of the regulation of transcript Aloxl5. IGF-I induced altered gene expression in relation to its effect on weight gain. This study underlines that there is an entity of transcripts involved in neuroprotection and vascular tone that is regulated by both systemic GH and IGF-I. For other transcripts, the longer duration of this study did not significantly enhance the marginal effects of GH administration seen previously. © 2018 Neuroendocrinology Letters
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| 10. |
- Walser, Marion, 1961, et al.
(författare)
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Mode of GH administration and gene expression in the female rat brain.
- 2017
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Ingår i: The Journal of endocrinology. - 1479-6805. ; 233:2, s. 187-196
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Tidskriftsartikel (refereegranskat)abstract
- The endogenous secretion of growth hormone (GH) is sexually dimorphic in rats with females having a more even and males a more pulsatile secretion and low trough levels. The mode of GH administration, mimicking the sexually dimorphic secretion, has different systemic effects. In the brains of male rats, we have previously found that the mode of GH administration differently affects neuron-haemoglobin beta (Hbb) expression whereas effects on other transcripts were moderate. The different modes of GH administration could have different effects on brain transcripts in female rats. Hypophysectomised female rats were given GH either as injections twice daily or as continuous infusion and GH-responsive transcripts were assessed by quantitative reverse transcription polymerase chain reaction in the hippocampus and parietal cortex (cortex). The different modes of GH-administration markedly increased Hbb and 5'-aminolevulinate synthase 2 (Alas2) in both brain regions. As other effects were relatively moderate, a mixed model analysis (MMA) was used to investigate general effects of the treatments. In the hippocampus, MMA showed that GH-infusion suppressed glia- and neuron-related transcript expression levels, whereas GH-injections increased expression levels. In the cortex, GH-infusion instead increased neuron-related transcripts, whereas GH-injections had no significant effect. Interestingly, this contrasts to previous results obtained from male rat cortex where GH-infusion generally decreased expression levels. In conclusion, the results indicate that there is a small but significant difference in response to mode of GH administration in the hippocampus as compared to the cortex. For both modes of GH administration, there was a robust effect on Hbb and Alas2.
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