| 1. |
- Attié, David, et al.
(författare)
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A time projection chamber with GEM-based readout
- 2017
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Ingår i: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. - : Elsevier BV. - 0168-9002. ; 856, s. 109-118
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Tidskriftsartikel (refereegranskat)abstract
- For the International Large Detector concept at the planned International Linear Collider, the use of time projection chambers (TPC) with micro-pattern gas detector readout as the main tracking detector is investigated. In this paper, results from a prototype TPC, placed in a 1. T solenoidal field and read out with three independent Gas Electron Multiplier (GEM) based readout modules, are reported. The TPC was exposed to a 6. GeV electron beam at the DESY II synchrotron. The efficiency for reconstructing hits, the measurement of the drift velocity, the space point resolution and the control of field inhomogeneities are presented.
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| 2. |
- Babic, Vedad, 1990, et al.
(författare)
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Fates of Hydrogen During Alumina Growth Below Yttria Nodules in FeCrAl(RE) at Low Partial Pressures of Water
- 2017
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Ingår i: Electrocatalysis. - : Springer Science and Business Media LLC. - 1868-5994 .- 1868-2529. ; 8:6, s. 565-576
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Tidskriftsartikel (refereegranskat)abstract
- Oxidation of FeCrAl(Re), when exposed to similar to 35 ppm of water as sole supply of oxygen in predominantly nitrogen atmosphere, has two characteristic signatures. One is the internal nitridation owing to chromia nodules acting windows toward nitrogen permeation locally short-circuiting the protective alpha-Al2O3 scale. The second remarkable feature is the growth of thick, apparently defect-rich alumina scale under yttria-rich nodules. Hence, one part of the present study comprises exploratory DFT calculations to discriminate between the impacts of chromia and yttria viz. nitrogen permeation. The second part concerns boundary conditions for apparent rapid growth of alumina under yttria nodules. Yttria-associated surface energy stabilization of defect-rich alumina in presence of water was argued to involve hydrolysis-driven hydroxylation of said interface. Subsequent inward growth of the alumina scale was associated with outward diffusion of oxygen vacancies to be accommodated by the remaining proton producing a hydride ion upon surfacing at yttria-decorated alumina interfaces. The latter comprises the cathode process in a quasi-Wagnerian context. Two fates were discussed for this surface ion. One has H--H+ recombination to form H-2 at the interface in conjunction with OH- accommodation upon hydration, while the second allows hydrogen to be incorporated at V-O sites in hydroxylated grain boundaries of the growing alumina scale. The latter was taken to explain the experimentally observed rapid oxide growth under yttria-rich nodules. Space charge due to proton reduction was proposed to cause transient inward cationic drag.
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| 3. |
- Berge, T. L L, et al.
(författare)
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Bisphenol A concentration in human saliva related to dental polymer-based fillings
- 2017
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Ingår i: Clinical Oral Investigations. - : Springer Science and Business Media LLC. - 1432-6981 .- 1436-3771. ; 21:8, s. 2561-2568
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: The aims of this study were to quantify salivary concentrations of bisphenol A (BPA) and to assess if presence of dental composite fillings is associated with higher BPA levels in saliva. Materials and methods: Twenty individuals with six or more tooth surfaces filled with polymer-based dental materials (composite group) and 20 individuals without any polymer-based materials (control group) were included in the study. Saliva was collected in polypropylene tubes and stored at −80 °C before analysis. Concentration of free (unconjugated) and total bisphenol A was determined by liquid chromatography/mass spectrometry (LC/MS). Values below limit of detection (0.1 ng/mL) were set to one-half of the limit of detection. Mann-Whitney U test (one sided; the Exact Tests Option in IBM-SPSS version 21) was used for the statistical analyses. Results: The concentration of BPA in saliva was very low. In the composite group, 8 of 20 samples had detectable concentrations of BPA. In the control group, 3 of 20 samples had detectable concentrations of BPA. Statistical analysis indicated that the concentration of unconjugated BPA was slightly higher in the composite group (p = 0.044) than in the control group. Conclusions: Presence of dental composites may be associated with slightly higher concentration of unconjugated BPA in saliva. However, additional studies using sensitive analytical methods are needed before firm conclusions can be drawn. Influence from other factors, like food intake and time of the day for saliva sampling, must be considered. Clinical relevance: The relative contribution of existing polymer-based dental fillings to total BPA exposure seems to be low.
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| 4. |
- Blanton, Michael R., et al.
(författare)
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Sloan Digital Sky Survey IV : Mapping the Milky Way, Nearby Galaxies, and the Distant Universe
- 2017
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Ingår i: Astronomical Journal. - : IOP Publishing Ltd. - 0004-6256 .- 1538-3881. ; 154:1
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Tidskriftsartikel (refereegranskat)abstract
- We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing three major spectroscopic programs. The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky Way stars at high resolution and. high signal-to-noise ratios in the near-infrared. The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey is obtaining spatially resolved spectroscopy for thousands of nearby galaxies (median z similar to 0.03). The extended Baryon Oscillation Spectroscopic Survey (eBOSS) is mapping the galaxy, quasar, and neutral gas distributions between z similar to 0.6 and 3.5 to constrain cosmology using baryon acoustic oscillations, redshift space distortions, and the shape of the power spectrum. Within eBOSS, we are conducting two major subprograms: the SPectroscopic IDentification of eROSITA Sources (SPIDERS), investigating X-ray AGNs. and galaxies in X-ray clusters, and the Time Domain Spectroscopic Survey (TDSS), obtaining spectra of variable sources. All programs use the 2.5 m Sloan Foundation Telescope at the. Apache Point Observatory; observations there began in Summer 2014. APOGEE-2 also operates a second near-infrared spectrograph at the 2.5 m du Pont Telescope at Las Campanas Observatory, with observations beginning in early 2017. Observations at both facilities are scheduled to continue through 2020. In keeping with previous SDSS policy, SDSS-IV provides regularly scheduled public data releases; the first one, Data Release 13, was made available in 2016 July.
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| 5. |
- Chatziioannou, Aristotelis, et al.
(författare)
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Blood-based omic profiling supports female susceptibility to tobacco smoke-induced cardiovascular diseases
- 2017
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- We recently reported that differential gene expression and DNA methylation profiles in blood leukocytes of apparently healthy smokers predicts with remarkable efficiency diseases and conditions known to be causally associated with smoking, suggesting that blood-based omic profiling of human populations may be useful for linking environmental exposures to potential health effects. Here we report on the sex-specific effects of tobacco smoking on transcriptomic and epigenetic features derived from genome-wide profiling in white blood cells, identifying 26 expression probes and 92 CpG sites, almost all of which are affected only in female smokers. Strikingly, these features relate to numerous genes with a key role in the pathogenesis of cardiovascular disease, especially thrombin signaling, including the thrombin receptors on platelets F2R (coagulation factor II (thrombin) receptor; PAR1) and GP5 (glycoprotein 5), as well as HMOX1 (haem oxygenase 1) and BCL2L1 (BCL2-like 1) which are involved in protection against oxidative stress and apoptosis, respectively. These results are in concordance with epidemiological evidence of higher female susceptibility to tobacco-induced cardiovascular disease and underline the potential of blood-based omic profiling in hazard and risk assessment.
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| 6. |
- Ekedahl, Harald, et al.
(författare)
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The 1-Year Results of Lumbar Transforaminal Epidural Steroid Injection in Patients with Chronic Unilateral Radicular Pain : The Relation to MRI Findings and Clinical Features
- 2017
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Ingår i: American Journal of Physical Medicine and Rehabilitation. - 0894-9115. ; 96:9, s. 654-662
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: In patients with chronic radicular pain, we aimed to evaluate subgroup differences in 1-yr response to transforaminal epidural steroid injection. DESIGN: In this longitudinal cohort study of 100 subjects, 170 transforaminal epidural steroid injections were performed for 1 yr. The sample was stratified by type of disc herniation (protrusion n = 57, extrusion n = 27), by location of disc herniation (central/subarticular n = 60, foraminal n = 24), by grade of nerve root compression (low-grade compression n = 61, high-grade subarticular nerve compression n = 14, high-grade foraminal nerve compression n = 25), and by positive Slump test (n = 67). Treatment response was evaluated by visual analogue scale leg pain and self-reported disability (Oswestry Disability Index). Logistic regression was used to analyze the predictive value of baseline characteristics including the stratified subgroups. RESULTS: High-grade subarticular nerve compression predicted the 1-yr improvement in both visual analogue scale leg pain (P = 0.046) and Oswestry Disability Index (P = 0.027). Low age (P < 0.001), short duration of leg pain (P = 0.015), and central/subarticular disc herniation (P = 0.017) predicted improvement in Oswestry Disability Index. CONCLUSIONS: In patients treated with one or several transforaminal epidural steroid injections due to chronic lumbar radicular pain, clinical findings failed to predict the 1-yr treatment response. Low age, short duration of leg pain, central/subarticular disc herniation, and high-grade subarticular nerve compression predicted a favorable 1-yr response to transforaminal epidural steroid injection.
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| 7. |
- Geers, Christine, 1982, et al.
(författare)
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Properties of Alumina/Chromia Scales in N2-Containing Low Oxygen Activity Environment Investigated by Experiment and Theory
- 2017
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Ingår i: Oxidation of Metals. - : Springer Science and Business Media LLC. - 1573-4889 .- 0030-770X. ; 87:3-4, s. 321-332
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Tidskriftsartikel (refereegranskat)abstract
- The FeCrAl alloy Kanthal APMT™ was exposed to N2–5%H2 at 900 °C. Trace oxygen in the gases supplied an oxygen activity which was sufficient to render alumina and chromia thermodynamically stable. The exposures revealed that the oxide scale was penetrated by nitrogen exclusively at chromia domains. Microscopic analyses of the oxide scale did not reveal micro-cracks that could serve as points-of-entry for nitrogen. Instead it is suggested that nitrogen is transported through a dense chromia layer. Density functional theory was employed to investigate decisive nitrogen surface chemistry and transport properties in chromia and alumina. The study was used to validate that the complex redox chemistry of Cr3+ as opposed to Al3+ is a sufficient discriminating factor between alumina and chromia, facilitating N2 dissociation and mobility of N in chromia.
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| 8. |
- Gyllenhammar, Irina, et al.
(författare)
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Diverging temporal trends of human exposure to bisphenols and plastizisers, such as phthalates, caused by substitution of legacy EDCs?
- 2017
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Ingår i: Environmental Research. - : Elsevier BV. - 0013-9351. ; 153, s. 48-54
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Tidskriftsartikel (refereegranskat)abstract
- Phthalates and phenolic substances were investigated in urine samples from first-time mothers in Uppsala, Sweden, collected between 2009 and 2014. These substances have a comparably fast metabolism and urinary metabolites are predominantly analysed. The main aim was to investigate if measures to decrease production and use of certain phthalates and bisphenol A (BPA) have resulted in decreased human exposure, and to determine if exposures to replacement chemicals have increased. Temporal trends were evaluated for metabolites (n=13) of seven phthalates, a phthalate replacer, four different bisphenols, triclosan, one organophosphate-based flame retardant, and for two pesticides. The results showed downward trends of several phthalates which are in the process of being regulated and phased out. Concomitantly, an increasing trend was seen for a metabolite of the phthalate replacer Di-iso-nonylcyclohexane 1,2-dicarboxylate (DiNCH). Bisphenol A (BPA) showed a downward trend, whereas bisphenol F, identified as one of the substitutes for BPA, showed an increasing trend. The decreasing trend of triclosan is likely due to declining use within the EU. Temporal trend studies of urine samples make it possible to investigate human exposure to rapidly metabolised substances and study how measures taken to regulate and replace problematic chemicals affect human exposure.
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| 9. |
- Holmberg, Sara, et al.
(författare)
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High levels of vitamin D associated with less ischemic heart disease - a nested case-control study among rural men in Sweden
- 2017
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Ingår i: AAEM. - : Institute of Rural Health. - 1232-1966 .- 1898-2263. ; 24:2, s. 288-293
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Tidskriftsartikel (refereegranskat)abstract
- Introduction and objective. Low levels of serum vitamin D have been associated with increased occurrence of ischemic heart disease (IHD), but findings are inconsistent, e.g. seasonal variation is not always considered in the analyses. The aim of this study was to investigate whether vitamin D is associated with IHD among rural middle-aged men in Sweden when seasonal variation is taken into account. Materials and method. A nested case-control study was performed within a population-based cohort of Swedish farmers and rural residents followed for 20 years. Outcomes were from national health registers. For 276 cases (IHD at any time during follow-up), and for 276 aged-matched controls free of cardiovascular diseases or diabetes, serum levels of vitamin D (25-hydroxyvitamin D-3) were analyzed with liquid chromatography/tandem mass spectrometry (LC/MS/MS), in stored blood samples drawn at the baseline survey in 1990-91. The odds ratio (OR) with 95% confidence intervals (CI) of IHD for vitamin D-quartiles (based on measured as well as adjusted for month of sampling) was evaluated in logistic regression models; potential confounders were taken into account. Results. The measured mean vitamin D levels were 27.6 ng/ml(standard deviation (sd) 8.2 ng/ml) and 28.8 ng/ml (sd 9.0) among cases and controls, respectively. Compared to the quartile with the lowest month-adjusted vitamin D levels, the risk of IHD was significantly lower in the highest quartile (OR=0.46, 95% CI 0.25-0.84, p=0.012) in the fully-adjusted model. Conclusion. Rural Swedish men in the highest quartile of serum vitamin D had halved relative risk of IHD, compared to those in the lowest quartile.
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| 10. |
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