| 1. |
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| 2. |
- Aaron, F. D., et al.
(författare)
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Multi-leptons with high transverse momentum at HERA
- 2009
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Ingår i: Journal of High Energy Physics. - : Springer Science and Business Media LLC. - 1029-8479. ; :10
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Tidskriftsartikel (refereegranskat)abstract
- Events with at least two high transverse momentum leptons (electrons or muons) are studied using the H1 and ZEUS detectors at HERA with an integrated luminosity of 0.94 fb(-1). The observed numbers of events are in general agreement with the Standard Model predictions. Seven di- and tri-lepton events are observed in e(+)p collision data with a scalar sum of the lepton transverse momenta above 100 GeV while 1.94 +/- 0.17 events are expected. Such events are not observed in e(-)p collisions for which 1.19 +/- 0.12 are predicted. Total visible and differential di-electron and di-muon photoproduction cross sections are extracted in a restricted phase space dominated by photon-photon collisions.
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| 3. |
- Jimenez, J. L., et al.
(författare)
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Evolution of Organic Aerosols in the Atmosphere
- 2009
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 326:5959, s. 1525-1529
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Tidskriftsartikel (refereegranskat)abstract
- Organic aerosol (OA) particles affect climate forcing and human health, but their sources and evolution remain poorly characterized. We present a unifying model framework describing the atmospheric evolution of OA that is constrained by high-time-resolution measurements of its composition, volatility, and oxidation state. OA and OA precursor gases evolve by becoming increasingly oxidized, less volatile, and more hygroscopic, leading to the formation of oxygenated organic aerosol (OOA), with concentrations comparable to those of sulfate aerosol throughout the Northern Hemisphere. Our model framework captures the dynamic aging behavior observed in both the atmosphere and laboratory: It can serve as a basis for improving parameterizations in regional and global models.
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| 4. |
- Liu, Kui, et al.
(författare)
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Kallikrein genes are associated with lupus and glomerular basement membrane-specific antibody-induced nephritis in mice and humans
- 2009
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Ingår i: Journal of Clinical Investigation. - 0021-9738 .- 1558-8238. ; 119:4, s. 911-923
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Tidskriftsartikel (refereegranskat)abstract
- Immune-mediated nephritis contributes to disease in systemic lupus erythematosus, Goodpasture syndrome (caused by antibodies specific for glomerular basement membrane [anti-GBM antibodies]), and spontaneous lupus nephritis. Inbred mouse strains differ in susceptibility to anti-GBM antibody-induced and spontaneous lupus nephritis. This study sought to clarify the genetic and molecular factors that maybe responsible for enhanced immune-mediated renal disease in these models. When the kidneys of 3 mouse strains sensitive to anti-GBM antibody-induced nephritis were compared with those of 2 control strains using microarray analysis, one-fifth of the underexpressed genes belonged to the kallikrein gene family,which encodes serine esterases. Mouse strains that upregulated renal and urinary kallikreins exhibited less evidence of disease. Antagonizing the kallikrein pathway augmented disease, while agonists dampened the severity of anti-GBM antibody-induced nephritis. In addition, nephritis-sensitive mouse strains had kallikrein haplotypes that were distinct from those of control strains, including several regulatory polymorphisms,some of which were associated with functional consequences. Indeed, increased susceptibility to anti-GBM antibody-induced nephritis and spontaneous lupus nephritis was achieved by breeding mice with a genetic interval harboring the kallikrein genes onto a disease-resistant background. Finally, both human SLE and spontaneous lupus nephritis were found to be associated with kallikrein genes, particularly KLK1 and the KLK3 promoter, when DNA SNPs from independent cohorts of SLE patients and controls were compared. Collectively, these studies suggest that kallikreins are protective disease-associated genes in anti-GBM antibody-induced nephritis and lupus.
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| 5. |
- Hallquist, Mattias, 1969, et al.
(författare)
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The formation, properties and impact of secondary organic aerosol: Current and emerging issues
- 2009
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Ingår i: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 9:14, s. 5155-5236
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Tidskriftsartikel (refereegranskat)abstract
- Secondary organic aerosol (SOA) accounts for a significant fraction of ambient tropospheric aerosol and a detailed knowledge of the formation, properties and transformation of SOA is therefore required to evaluate its impact on atmospheric processes, climate and human health. The chemical and physical processes associated with SOA formation are complex and varied, and, despite considerable progress in recent years, a quantitative and predictive understanding of SOA formation does not exist and therefore represents a major research challenge in atmospheric science. This review begins with an update on the current state of knowledge on the global SOA budget and is followed by an overview of the atmospheric degradation mechanisms for SOA precursors, gas-particle partitioning theory and the analytical techniques used to determine the chemical composition of SOA. A survey of recent laboratory, field and modeling studies is also presented. The following topical and emerging issues are highlighted and discussed in detail: molecular characterization of biogenic SOA constituents, condensed phase reactions and oligomerization, the interaction of atmospheric organic components with sulfuric acid, the chemical and photochemical processing of organics in the atmospheric aqueous phase, aerosol formation from real plant emissions, interaction of atmospheric organic components with water, thermodynamics and mixtures in atmospheric models. Finally, the major challenges ahead in laboratory, field and modeling studies of SOA are discussed and recommendations for future research directions are proposed.
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| 6. |
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| 7. |
- Kaput, J, et al.
(författare)
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The case for strategic international alliances to harness nutritional genomics for public and personal health
- 2005
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Ingår i: The British journal of nutrition. - : Cambridge University Press (CUP). - 0007-1145 .- 1475-2662. ; 94:5, s. 623-632
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Tidskriftsartikel (refereegranskat)abstract
- Nutrigenomics is the study of how constituents of the diet interact with genes, and their products, to alter phenotype and, conversely, how genes and their products metabolise these constituents into nutrients, antinutrients, and bioactive compounds. Results from molecular and genetic epidemiological studies indicate that dietary unbalance can alter gene–nutrient interactions in ways that increase the risk of developing chronic disease. The interplay of human genetic variation and environmental factors will make identifying causative genes and nutrients a formidable, but not intractable, challenge. We provide specific recommendations for how to best meet this challenge and discuss the need for new methodologies and the use of comprehensive analyses of nutrient–genotype interactions involving large and diverse populations. The objective of the present paper is to stimulate discourse and collaboration among nutrigenomic researchers and stakeholders, a process that will lead to an increase in global health and wellness by reducing health disparities in developed and developing countries.
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| 8. |
- Lambert, A., et al.
(författare)
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Validation of the Aura Microwave Limb Sounder middle atmosphere water vapor and nitrous oxide measurements
- 2007
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Ingår i: Journal of Geophysical Research. - 0148-0227 .- 2156-2202. ; 112:D24
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Tidskriftsartikel (refereegranskat)abstract
- The quality of the version 2.2 (v2.2) middle atmosphere water vapor and nitrous oxide measurements from the Microwave Limb Sounder (MLS) on the Earth Observing System (EOS) Aura satellite is assessed. The impacts of the various sources of systematic error are estimated by a comprehensive set of retrieval simulations. Comparisons with correlative data sets from ground-based, balloon and satellite platforms operating in the UV/ visible, infrared and microwave regions of the spectrum are performed. Precision estimates are also validated, and recommendations are given on the data usage. The v2.2 H 2 O data have been improved over v1.5 by providing higher vertical resolution in the lower stratosphere and better precision above the stratopause. The single-profile precision is ∼0.2-0.3 ppmv (4-9%), and the vertical resolution is ∼3-4 km in the stratosphere. The precision and vertical resolution become worse with increasing height above the stratopause. Over the pressure range 0.1-0.01 hPa the precision degrades from 0.4 to 1.1 ppmv (6-34%), and the vertical resolution degrades to ∼12-16 km. The accuracy is estimated to be 0.2-0.5 ppmv (4-11%) for the pressure range 68-0.01 hPa. The scientifically useful range of the H 2 O data is from 316 to 0.002 hPa, although only the 82-0.002 hPa pressure range is validated here. Substantial improvement has been achieved in the v2.2 N 2 O data over v1.5 by reducing a significant low bias in the stratosphere and eliminating unrealistically high biased mixing ratios in the polar regions. The single-profile precision is ∼13-25 ppbv (7-38%), the vertical resolution is ∼4-6 km and the accuracy is estimated to be 3-70 ppbv (9-25%) for the pressure range 100-4.6 hPa. The scientifically useful range of the N 2 O data is from 100 to 1 hPa. Copyright 2007 by the American Geophysical Union.
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| 9. |
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| 10. |
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| 11. |
- Lourdudoss, Sebastian, et al.
(författare)
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Heteroepitaxy and selective epitaxy for discrete and integrated devices
- 2006
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Ingår i: 2006 CONFERENCE ON OPTOELECTRONIC AND MICROELECTRONIC MATERIALS & DEVICES. - NEW YORK : IEEE. - 9781424405770 ; , s. 309-311
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Konferensbidrag (refereegranskat)abstract
- We present first results on heteroepitaxy of InP on silicon on insulator (SOI). We also demonstrate InP nanopillar fabrication by means of selective epitaxy. Selective epitaxy is also exploited to fabricate advanced photonic integrated devices for Optical Code Division Multiplex Access (OCDMA) networking applications.
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| 12. |
- Orozco, G., et al.
(författare)
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Study of the role of functional variants of SLC22A4, RUNX1 and SUMO4 in systemic lupus erythematosus
- 2006
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Ingår i: Annals of the Rheumatic Diseases. - : BMJ. - 0003-4967 .- 1468-2060. ; 65:6, s. 791-5
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Functional polymorphisms of the solute carrier family 22, member 4 (SLC22A4), runt related transcription factor 1 (RUNX1) and small ubiquitin-like modifier 4 (SUMO4) genes have been shown to be associated with several autoimmune diseases. OBJECTIVE: To test the possible role of these variants in susceptibility to or severity of systemic lupus erythematosus (SLE), on the basis that common genetic bases are shared by autoimmune disorders. METHODS: 597 SLE patients and 987 healthy controls of white Spanish origin were studied. Two additional cohorts of 228 SLE patients from Sweden and 122 SLE patients from Colombia were included. A case-control association study was carried out with six single nucleotide polymorphisms (SNP) spanning the SLC22A4 gene, one SNP in RUNX1 gene, and one additional SNP in SUM04 gene. RESULTS: No significant differences were observed between SLE patients and healthy controls when comparing the distribution of the genotypes or alleles of any of the SLC22A4, RUNX1, or SUMO4 polymorphisms tested. Significant differences were found in the distribution of the SUMO4 genotypes and alleles among SLE patients with and without nephritis, but after multiple testing correction, the significance of the association was lost. The association of SUMO4 with nephritis could not be verified in two independent SLE cohorts from Sweden and Colombia. CONCLUSIONS: These results suggest that the SLC22A4, RUNX1, and SUMO4 polymorphisms analysed do not play a role in the susceptibility to or severity of SLE.
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| 13. |
- De Oliveira Santos, F., et al.
(författare)
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Study of 19Na at SPIRAL
- 2005
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Ingår i: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-601X .- 1434-6001. ; 24:2, s. 237-247
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Tidskriftsartikel (refereegranskat)abstract
- The excitation function for the elastic-scattering reaction p( 18 Ne, p) 18 Ne was measured with the first radioactive beam from the SPIRAL facility at the GANIL laboratory and with a solid cryogenic hydrogen target. Several broad resonances have been observed, corresponding to new excited states in the unbound nucleus 19 Na. In addition, two-proton emission events have been identified and are discussed.
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| 14. |
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| 15. |
- Lenzen, M. J., et al.
(författare)
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Under-utilization of evidence-based drug treatment in patients with heart failure is only partially explained by dissimilarity to patients enrolled in landmark trials: a report from the Euro Heart Survey on Heart Failure
- 2005
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Ingår i: European heart journal. - : Oxford University Press (OUP). - 0195-668X .- 1522-9645. ; 26:24, s. 2706-13
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Tidskriftsartikel (refereegranskat)abstract
- AIMS: Surveys on heart failure management suggest under-utilization of life-saving evidence-based treatment. Evidence-based medicine and clinical guidelines are based on the results of randomized controlled trials. Therefore, we investigated how patients who fulfilled the enrolment criteria of randomized trials were treated in real life. METHODS AND RESULTS: We selected three large placebo-controlled trials of patients with chronic heart failure, in which ACE-inhibitors (ACE-Is), beta-blockers, and spironolactone proved to be safe and effective. The major enrolment criteria of trials were identified and applied to patients enrolled in the Euro Heart Survey on Heart Failure to identify the proportion of patients eligible for treatment and also treated appropriately. Of the 10 701 patients who were enrolled in the Euro Heart Survey on Heart Failure, only a small percentage (13%) would have qualified for participation in at least one of the selected trials. Patients who fulfilled enrolment criteria of the identified trials were more likely to be treated with ACE-Is (83% of SOLVD-eligible patients), beta-blockers (54% of MERIT-HF-eligible patients), and aldosterone antagonists (43% of RALES-eligible patients) than trial-ineligible patients. Almost half of SOLVD-eligible patients who were treated with ACE-Is received the target dose as recommended in the guidelines, but only <10% of MERIT-HF eligible patients who were treated with beta-blockers received the target dose. CONCLUSION: ACE-Is are widely utilized but given in lower doses than proven effective in clinical trials. beta-Blockers are underused and given in lower doses to patients who fulfil the enrolment criteria of relevant landmark trials.
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| 16. |
- Buehler, Stefan, et al.
(författare)
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A concept for a satellite mission to measure cloud ice water path, ice particle size, and cloud altitude
- 2007
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Ingår i: Quarterly Journal of the Royal Meteorological Society. - : Wiley. - 0035-9009 .- 1477-870X. ; 133:S2, s. 109-128
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Tidskriftsartikel (refereegranskat)abstract
- A passive satellite radiometer operating at submillimetre wavelengths can measure cloud ice water path (IWP), ice particle size, and cloud altitude. The paper first discusses the scientific background for such measurements. Formal scientific mission requirements are derived, based on this background and earlier assessments. The paper then presents a comprehensive prototype instrument and mission concept, and demonstrates that it meets the requirements. The instrument is a conically scanning 12-channel radiometer with channels between 183 and 664 GHz, proposed to fly in tandem with one of the Metop satellites. It can measure IWP with a relative accuracy of approximately 20% and a detection threshold of approximately 2 g m−2. The median mass equivalent sphere diameter of the ice particles can be measured with an accuracy of approximately 30 µm, and the median IWP cloud altitude can be measured with an accuracy of approximately 300 m. All the above accuracies are median absolute error values; root mean square error values are approximately twice as high, due to rare outliers.
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| 17. |
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| 18. |
- Delgado-Vega, Angelica M., et al.
(författare)
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Replication of the TNFSF4 (OX40L) promoter region association with systemic lupus erythematosus
- 2009
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Ingår i: Genes and Immunity. - : Springer Science and Business Media LLC. - 1466-4879 .- 1476-5470. ; 10:3, s. 248-253
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Tidskriftsartikel (refereegranskat)abstract
- The tumor necrosis factor ligand superfamily member 4 gene (TNFSF4) encodes the OX40 ligand (OX40L), a costimulatory molecule involved in T-cell activation. A recent study demonstrated the association of TNFSF4 haplotypes located in the upstream region with risk for or protection from systemic lupus erythematosus (SLE). To replicate this association, five single nucleotide polymorphisms (SNPs) tagging the previously associated haplotypes and passing the proper quality-control filters were tested in 1312 cases and 1801 controls from Germany, Italy, Spain and Argentina. The association of TNFSF4 with SLE was replicated in all the sets except Spain. There was a unique risk haplotype tagged by the minor alleles of the SNPs rs1234317 (pooled odds ratio (OR)=1.39, P=0.0009) and rs12039904 (pooled OR=1.38, P=0.0012). We did not observe association to a single protective marker (rs844644) or haplotype as the first study reported; instead, we observed different protective haplotypes, all carrying the major alleles of both SNPs rs1234317 and rs12039904. Association analysis conditioning on the haplotypic background confirmed that these two SNPs explain the entire haplotype effect. This first replication study confirms the association of genetic variation in the upstream region of TNFSF4 with susceptibility to SLE.
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| 19. |
- Gerlofs-Nijland, Miriam E, et al.
(författare)
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Toxicity of coarse and fine particulate matter from sites with contrasting traffic profiles.
- 2007
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Ingår i: Inhalation Toxicology. - : Taylor & Francis. - 0895-8378 .- 1091-7691. ; 19:13, s. 1055-69
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Tidskriftsartikel (refereegranskat)abstract
- Residence in urban areas with much traffic has been associated with various negative health effects. However, the contribution of traffic emissions to these adverse health effects has not been fully determined. Therefore, the objective of this in vivo study is to compare the pulmonary and systemic responses of rats exposed to particulate matter (PM) obtained from various locations with contrasting traffic profiles. Samples of coarse (2.5 mu m-10 mu m) and fine (0.1 mu m-2.5 mu m) PM were simultaneously collected at nine sites across Europe with a high-volume cascade impactor. Six PM samples from various locations were selected on the basis of contrast in in vitro analysis, chemical composition, and traffic profiles. We exposed spontaneously hypertensive (SH) rats to a single dose (3 mg PM/kg body weight or 10 mg PM/kg body weight) of either coarse or fine PM by intratracheal instillation. We assessed changes in biochemical markers, cell differentials, and histopathological changes in the lungs and blood 24 h postexposure. The dose-related adverse effects that both coarse and fine PM induced in the lungs and vascular system were mainly related to cytotoxicity, inflammation, and blood viscosity. We observed clear differences in the extent of these responses to PM from the various locations at equivalent dose levels. There was a trend that suggests that samples from high-traffic sites were the most toxic. It is likely that the toxicological responses of SH rats were associated with specific PM components derived from brake wear (copper and barium), tire wear (zinc), and wood smoke (potassium).
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| 20. |
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| 21. |
- Menoni, C. S., et al.
(författare)
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Advances in Nanoscale Resolution Soft X-Ray Laser Microscopy
- 2009
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Ingår i: X-RAY LASERS 2008, PROCEEDINGS. - : Springer Netherlands. - 9781402099236 ; , s. 341-347
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Konferensbidrag (refereegranskat)abstract
- We review our most recent results on table-top, nanometer-scale resolution, microscopy using compact soft x-ray lasers developed at Colorado State University. We have realized the first demonstration of wavelength-resolution microscopy in the soft x-ray spectral range. Images of carbon nanotubes, 50 nm in diameter, were obtained with a single similar to 1 ns duration laser pulse from a desk-top size capinary discharge 46.9 nm laser. We fully characterized the new microscope by measuring the modulation transfer function of the instrument for zone plate objectives with three different numerical apertures, demonstrating that 54 nm half-period structures can be resolved. The combination of near-wavelength spatial resolution with high temporal resolution imaging opens myriad opportunities for imaging nanoscale structures.
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| 22. |
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| 23. |
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| 24. |
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| 25. |
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| 26. |
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| 27. |
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| 28. |
- Urban, Joachim, 1964, et al.
(författare)
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Odin/SMR limb observations of stratospheric trace gases: Validation of N2O
- 2005
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Ingår i: Journal of Geophysical Research. - 0148-0227 .- 2156-2202. ; 110:9, s. D09301-20
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Tidskriftsartikel (refereegranskat)abstract
- The Sub-Millimetre Radiometer (Odin/SMR) on board the Odin satellite, launched on 20 February 2001, performs regular measurements of the global distribution of stratospheric nitrous oxide (N2O) using spectral observations of the J = 20&RARR; 19 rotational transition centered at 502.296 GHz. We present a quality assessment for the retrieved N2O profiles (level 2 product) by comparison with independent balloonborne and aircraftborne validation measurements as well as by cross-comparing with preliminary results from other satellite instruments. An agreement with the airborne validation experiments within 28 ppbv in terms of the root mean square (RMS) deviation is found for all SMR data versions (v222, v223, and v1.2) under investigation. More precisely, the agreement is within 19 ppbv for N2O volume mixing ratios (VMR) lower than 200 ppbv and within 10% for mixing ratios larger than 150 ppbv. Given the uncertainties due to atmospheric variability inherent to such comparisons, these values should be interpreted as upper limits for the systematic error of the Odin/SMR N2O measurements. Odin/SMR N2O mixing ratios are systematically slightly higher than nonvalidated data obtained from the Improved Limb Atmospheric Spectrometer-II (ILAS-II) on board the Advanced Earth Observing Satellite-II (ADEOS-II). Root mean square deviations are generally within 23 ppbv (or 20% for VMR-N2O > 100 ppbv) for versions 222 and 223. The comparison with data obtained from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) on the Envisat satellite yields a good agreement within 9-17 ppbv (or 10% for VMR-N2O > 100 ppbv) for the same data versions. Odin/SMR version 1.2 data show somewhat larger RMS deviations and a higher positive bias.
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| 29. |
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| 30. |
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| 31. |
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| 32. |
- del Rio, Jose C., et al.
(författare)
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Highly Acylated (Acetylated and/or p-Coumaroylated) Native Lignins from Diverse Herbaceous Plants
- 2008
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Ingår i: Journal of Agricultural and Food Chemistry. - : American Chemical Society (ACS). - 0021-8561 .- 1520-5118. ; 56:20, s. 9525-9534
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Tidskriftsartikel (refereegranskat)abstract
- The structure of lignins isolated from the herbaceous plants sisal (Agave sisalana), kenaf (Hibiscus cannabinus), abaca (Musa textilis) and curaua (Ananas erectifolius) has been studied upon spectroscopic (2D-NMR) and chemical degradative (derivatization followed by reductive cleavage) methods. The analyses demonstrate that the structure of the lignins from these plants is highly remarkable, being extensively acylated at the gamma-carbon of the lignin side chain (up to 80% acylation) with acetate and/or p-coumarate groups and preferentially over syringyl units. Whereas the lignins from sisal and kenaf are gamma-acylated exclusively with acetate groups, the lignins from abaca and curaua are esterified with acetate and p-coumnarate groups. The structures of all these highly acylated lignins are characterized by a very high syringyl/guaiacyl ratio, a large predominance of beta-O-4' linkages (up to 94% of all linkages), and a strikingly low proportion of traditional beta-beta' linkages, which indeed are completely absent in the lignins from abaca and curaua. The occurrence of beta-beta' homocoupling and cross-coupling products of sinapyl acetate in the lignins from sisal and kenaf indicates that sinapyl alcohol is acetylated at the monomer stage and that, therefore, sinapyl acetate should be considered as a real monolignol involved in the lignification reactions.
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| 33. |
- Engels, D., et al.
(författare)
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Variability of masers in circumstellar shells on timescales of decades
- 2007
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Ingår i: Proceedings of the International Astronomical Union. - 1743-9213 .- 1743-9221. ; 3:S242, s. 318-319
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Konferensbidrag (refereegranskat)abstract
- Based on a 15-20 year long monitoring program of H2O masers and new observations of OH masers discovered 35 years ago, we studied the variability of maser emission in AGB stars over timescales of decades. The H2O maser features in the semi-regular variable stars RX Boo and SV Peg, and of the Mira stars U Her and R Cas, showed strong fluctuations superposed in case of the Mira stars on regular variations due to the pulsation of the stars. The spatial distribution of the emission regions in RX Boo and U Her showed deviations from spherical symmetry, which remained unchanged over >10 years. We conclude that the spatial asymmetry is determined by the underlying asymmetry of the mass loss process. There is no evidence that mass loss rates or the wind geometry in these stars have varied over the last 20 years. In 2005 we re-detected at 1612 MHz the 114 OH/IR stars discovered before 1978, implying an OH maser lifetime of >2800 years (1). © 2008 International Astronomical Union.
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| 34. |
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| 35. |
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| 36. |
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| 37. |
- Gunthe, S. S., et al.
(författare)
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Cloud condensation nuclei in pristine tropical rainforest air of Amazonia: size-resolved measurements and modeling of atmospheric aerosol composition and CCN activity
- 2009
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Ingår i: Atmospheric Chemistry and Physics. - 1680-7324. ; 9:19, s. 7551-7575
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Tidskriftsartikel (refereegranskat)abstract
- Atmospheric aerosol particles serving as cloud condensation nuclei (CCN) are key elements of the hydrological cycle and climate. We have measured and characterized CCN at water vapor supersaturations in the range of S=0.10-0.82% in pristine tropical rainforest air during the AMAZE-08 campaign in central Amazonia. The effective hygroscopicity parameters describing the influence of chemical composition on the CCN activity of aerosol particles varied in the range of kappa approximate to 0.1-0.4 (0.16+/-0.06 arithmetic mean and standard deviation). The overall median value of kappa approximate to 0.15 was by a factor of two lower than the values typically observed for continental aerosols in other regions of the world. Aitken mode particles were less hygroscopic than accumulation mode particles (kappa approximate to 0.1 at D approximate to 50 nm; kappa approximate to 0.2 at D approximate to 200 nm), which is in agreement with earlier hygroscopicity tandem differential mobility analyzer (H-TDMA) studies. The CCN measurement results are consistent with aerosol mass spectrometry (AMS) data, showing that the organic mass fraction (f(org)) was on average as high as similar to 90% in the Aitken mode (D <= 100 nm) and decreased with increasing particle diameter in the accumulation mode (similar to 80% at D approximate to 200 nm). The kappa values exhibited a negative linear correlation with f(org) (R-2=0.81), and extrapolation yielded the following effective hygroscopicity parameters for organic and inorganic particle components: kappa(org)approximate to 0.1 which can be regarded as the effective hygroscopicity of biogenic secondary organic aerosol (SOA) and kappa(inorg)approximate to 0.6 which is characteristic for ammonium sulfate and related salts. Both the size dependence and the temporal variability of effective particle hygroscopicity could be parameterized as a function of AMS-based organic and inorganic mass fractions (kappa(p)=kappa(org) x f(org)+kappa(inorg) x f(inorg)). The CCN number concentrations predicted with kappa(p) were in fair agreement with the measurement results (similar to 20% average deviation). The median CCN number concentrations at S=0.1-0.82% ranged from N-CCN,N-0.10 approximate to 35 cm(-3) to N-CCN,N-0.82 approximate to 160 cm(-3), the median concentration of aerosol particles larger than 30 nm was N-CN,N-30 approximate to 200 cm(-3), and the corresponding integral CCN efficiencies were in the range of N-CCN,N-0.10/NCN,N-30 approximate to 0.1 to N-CCN,N-0.82/NCN,N-30 approximate to 0.8. Although the number concentrations and hygroscopicity parameters were much lower in pristine rainforest air, the integral CCN efficiencies observed were similar to those in highly polluted megacity air. Moreover, model calculations of N-CCN,N-S assuming an approximate global average value of kappa approximate to 0.3 for continental aerosols led to systematic overpredictions, but the average deviations exceeded similar to 50% only at low water vapor supersaturation (0.1%) and low particle number concentrations (<= 100 cm(-3)). Model calculations assuming aconstant aerosol size distribution led to higher average deviations at all investigated levels of supersaturation: similar to 60% for the campaign average distribution and similar to 1600% for a generic remote continental size distribution. These findings confirm earlier studies suggesting that aerosol particle number and size are the major predictors for the variability of the CCN concentration in continental boundary layer air, followed by particle composition and hygroscopicity as relatively minor modulators. Depending on the required and applicable level of detail, the information and parameterizations presented in this paper should enable efficient description of the CCN properties of pristine tropical rainforest aerosols of Amazonia in detailed process models as well as in large-scale atmospheric and climate models.
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| 38. |
- Hayes, Matthew, et al.
(författare)
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The escape of Lyman photons from a young starburst : The case of Haro 11
- 2007
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Ingår i: Monthly notices of the Royal Astronomical Society. - : Wiley-Blackwell. - 0035-8711 .- 1365-2966. ; 382:4, s. 1465-1480
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Tidskriftsartikel (refereegranskat)abstract
- Lyman α (Lyα) is one of the dominant tools used to probe the star-forming galaxy population at high redshift (z). However, astrophysical interpretations of data drawn from Lyα alone hinge on the Lyα escape fraction which, due to the complex radiative transport, may vary greatly. Here, we map the Lyα emission from the local luminous blue compact galaxy Haro 11, a known emitter of Lyα and the only known candidate for low-z Lyman continuum emission. To aid in the interpretation, we perform a detailed ultraviolet and optical multiwavelength analysis and model the stellar population, dust distribution, ionizing photon budget, and star-cluster population. We use archival X-ray observations to further constrain properties of the starburst and estimate the neutral hydrogen column density. The Lyα morphology is found to be largely symmetric around a single young star-forming knot and is strongly decoupled from other wavelengths. From general surface photometry, only very slight correlation is found between Lyα and Hα, E(B−V), and the age of the stellar population. Only around the central Lyα bright cluster do we find the Lyα/Hα ratio at values predicted by the recombination theory. The total Lyα escape fraction is found to be just 3 per cent. We compute that ∼90 per cent of the Lyα photons that escape do so after undergoing multiple resonance scattering events, masking their point of origin. This leads to a largely symmetric distribution and, by increasing the distance that photons must travel to escape, decreases the escape probability significantly. While dust must ultimately be responsible for the destruction of Lyα, it plays a little role in governing the observed morphology, which is regulated more by interstellar medium kinematics and geometry. We find tentative evidence for local Lyα equivalent width in the immediate vicinity of star clusters being a function of cluster age, consistent with hydrodynamic studies. We estimate the intrinsic production of ionizing photons and put further constraints of ∼9 per cent on the escaping fraction of photons at 900 Å.
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| 39. |
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| 40. |
- Lelliott, Christopher J., et al.
(författare)
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Ablation of PGC-1beta results in defective mitochondrial activity, thermogenesis, hepatic function, and cardiac performance
- 2006
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Ingår i: PLoS biology. - : Public Library of Science (PLoS). - 1544-9173 .- 1545-7885. ; 4:11
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Tidskriftsartikel (refereegranskat)abstract
- The transcriptional coactivator peroxisome proliferator-activated receptor-gamma coactivator-1beta (PGC-1beta) has been implicated in important metabolic processes. A mouse lacking PGC-1beta (PGC1betaKO) was generated and phenotyped using physiological, molecular, and bioinformatic approaches. PGC1betaKO mice are generally viable and metabolically healthy. Using systems biology, we identified a general defect in the expression of genes involved in mitochondrial function and, specifically, the electron transport chain. This defect correlated with reduced mitochondrial volume fraction in soleus muscle and heart, but not brown adipose tissue (BAT). Under ambient temperature conditions, PGC-1beta ablation was partially compensated by up-regulation of PGC-1alpha in BAT and white adipose tissue (WAT) that lead to increased thermogenesis, reduced body weight, and reduced fat mass. Despite their decreased fat mass, PGC1betaKO mice had hypertrophic adipocytes in WAT. The thermogenic role of PGC-1beta was identified in thermoneutral and cold-adapted conditions by inadequate responses to norepinephrine injection. Furthermore, PGC1betaKO hearts showed a blunted chronotropic response to dobutamine stimulation, and isolated soleus muscle fibres from PGC1betaKO mice have impaired mitochondrial function. Lack of PGC-1beta also impaired hepatic lipid metabolism in response to acute high fat dietary loads, resulting in hepatic steatosis and reduced lipoprotein-associated triglyceride and cholesterol content. Altogether, our data suggest that PGC-1beta plays a general role in controlling basal mitochondrial function and also participates in tissue-specific adaptive responses during metabolic stress.
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| 41. |
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| 42. |
- Olsson, Fredrik, et al.
(författare)
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Heteroepitaxy of InP on Silicon-on-Insulator for Optoelectronic Integration
- 2007
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Ingår i: ECS Transactions. - : The Electrochemical Society. - 1938-5862 .- 1938-6737. ; 3:39, s. 23-29
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Tidskriftsartikel (refereegranskat)abstract
- Epitaxial lateral overgrowth of InP was performed on patterned silicon-on-insulator (SOI) and compared with that on Si substrates in a low pressure hydride vapor phase epitaxy system. The InP was characterized by cathodoluminescence. No red shift of peak wavelength was detected for InP/SOI indicating a negligible thermal strain. Additional low energy peaks were found in some regions with a granular structure on the SOI template. A subsequent growth of an InGaAsP/InP MQW (multi quantum well) structure (λ∼1.5 μm) was grown on the SOI template and on a planar InP reference sample by metal-organic phase epitaxy. The MQW was characterized by room temperature photoluminescence. A red shift of 35 nm with respect to the reference sample was attributed to the selective-area effect causing thicker wells and/or an increased indium content. Although the PL intensity was weaker than that obtained for the reference, the FWHMs were comparable.
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| 43. |
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| 44. |
- Perez-Martinez, Pablo, et al.
(författare)
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Association between glucokinase regulatory protein (GCKR) and apolipoprotein A5 (APOA5) gene polymorphisms and triacylglycerol concentrations in fasting, postprandial, and fenofibrate-treated states
- 2009
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Ingår i: American Journal of Clinical Nutrition. - : Elsevier BV. - 1938-3207 .- 0002-9165. ; 89:1, s. 391-399
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Tidskriftsartikel (refereegranskat)abstract
- Background: Hypertriglyceridemia is a risk factor for cardiovascular disease. Variation in the apolipoprotein A5 (APOA5) and glucokinase regulatory protein (GCKR) genes has been associated with fasting plasma triacylglycerol. Objective: We investigated the combined effects of the GCKR rs780094C -> T, APOA5 -1131T -> C, and APOA5 56C -> G single nucleotide polymorphisms (SNPs) on fasting triacylglycerol in several independent populations and the response to a high-fat meal and fenofibrate interventions. Design: We used a cross-sectional design to investigate the association with fasting triacylglycerol in 8 populations from America, Asia, and Europe (n = 7730 men and women) and 2 intervention studies in US whites (n = `1061) to examine postprandial triacylglycerol after a high-fat meal and the response to fenofibrate. We defined 3 combined genotype groups: 1) protective (homozygous for the wild-type allele for all 3 SNPs); 2) intermediate (any mixed genotype not included in groups 1 and 3); and 3) risk (carriers of the variant alleles at both genes). Results: Subjects within the risk group had significantly higher fasting triacylglycerol and a higher prevalence of hypertriglyceridemia than did subjects in the protective group across all populations. Moreover, subjects in the risk group had a greater postprandial triacylglycerol response to a high-fat meal and greater fenofibrate-induced reduction of fasting triacylglycerol than did the other groups, especially among persons with hypertriglyceridemia. Subjects with the intermediate genotype had intermediate values (P for trend < 0.001). Conclusions: SNPs in GCKR and APOA5 have an additive effect on both fasting and postprandial triacylglycerol and contribute to the interindividual variability in response to fenofibrate treatment. Am J Clin Nutr 2009;89:391-9. Clin Nutr 2009; 89: 391-9.
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| 45. |
- Pusane, Ali Emre, et al.
(författare)
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Implementation Aspects of LDPC Convolutional Codes
- 2008
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Ingår i: IEEE Transactions on Communications. - 0090-6778. ; 56:7, s. 1060-1069
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Tidskriftsartikel (refereegranskat)abstract
- Potentially large storage requirements and long initial decoding delays are two practical issues related to the decoding of low-density parity-check (LDPC) convolutional codes using a continuous pipeline decoder architecture. In this paper, we propose several reduced complexity decoding strategies to lessen the storage requirements and the initial decoding delay without significant loss in performance. We also provide bit error rate comparisons of LDPC block and LDPC convolutional codes under equal processor (hardware) complexity and equal decoding delay assumptions. A partial syndrome encoder realization for LDPC convolutional codes is also proposed and analyzed. We construct terminated LDPC convolutional codes that are suitable for block transmission over a wide range of frame lengths. Simulation results show that, for terminated LDPC convolutional codes of sufficiently large memory, performance can be improved by increasing the density of the syndrome former matrix.
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| 46. |
- Rencoret, Jorge, et al.
(författare)
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Structural characterization of milled wood lignins from different eucalypt species
- 2008
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Ingår i: Holzforschung. - : Walter de Gruyter GmbH. - 0018-3830 .- 1437-434X. ; 62:5, s. 514-526
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Tidskriftsartikel (refereegranskat)abstract
- The chemical structure of milled-wood lignins from Eucalyptus globulus, E. nitens, E. maidenii, E. grandis, and E. dunnii was investigated. The lignins were characterized by analytical pyrolysis, thioacidolysis, and 2D-NMR that confirmed the predominance of syringyl over guaiacyl units and only showed traces of p-hydroxyphenyl units. E. globulus lignin had the highest syringyl content. The heteronuclear single quantum correlation (HSQC) NMR spectra yielded information about relative abundances of inter-unit linkages in the whole polymer. All the lignins showed a predominance of beta-O-4' ether linkages (66-72% of total side-chains), followed by beta-beta' resinol-type linkages (16-19%) and lower amounts of beta-5' phenylcoumarin-type (3-7%) and beta-1' spirodienone-type linkages (1-4%). The analysis of desulfurated thioacidolysis dimers provided additional information on the relative abundances of the various carbon-carbon and diaryl ether bonds, and the type of units ( syringyl or guaiacyl) involved in each of the above linkage types. Interestingly, 93-94% of the total beta-beta' dimers included two syringyl units indicating that most of the beta-beta' substructures identified in the HSQC spectra were of the syringaresinol type. Moreover, three isomers of a major trimeric compound were found which were tentatively identified as arising from a beta-beta' syringaresinol substructure attached to a guaiacyl unit through a 4-O-5' linkage.
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| 47. |
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| 48. |
- Salehi, S Albert, et al.
(författare)
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Free fatty acid receptor 1 (FFA(1)R/GPR40) and its involvement in fatty-acid-stimulated insulin secretion.
- 2005
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Ingår i: Cell and Tissue Research. - : Springer Science and Business Media LLC. - 1432-0878 .- 0302-766X. ; 322:2, s. 207-215
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Tidskriftsartikel (refereegranskat)abstract
- Free fatty acids (FFA) have generally been proposed to regulate pancreatic insulin release by an intracellular mechanism involving inhibition of CPT-1. The recently de-orphanized G-protein coupled receptor, FFA(1)R/GPR40, has been shown to be essential for fatty-acid-stimulated insulin release in MIN6 mouse insulinoma cells. The CPT-1 inhibitor, 2-bromo palmitate (2BrP), was investigated for its ability to interact with mouse FFA(1)R/GPR40. It was found to inhibit phosphatidyl inositol hydrolysis induced by linoleic acid (LA) (100 mu M in all experiments) in HEK293 cells transfected with FFA(1)R/GPR40 and in the MIN6 subclone, MIN6c4. 2BrP also inhibited LA-stimulated insulin release from mouse pancreatic islets. Mouse islets were subjected to antisense intervention by treatment with a FFA(1)R/GPR40-specific morpholino oligonucleotide for 48 h. Antisense treatment of islets suppressed LA-stimulated insulin release by 50% and by almost 100% when islets were pretreated with LA for 30 min before applying the antisense. Antisense treatment had no effect on tolbutamide-stimulated insulin release. Confocal microscopy using an FFA(1)R/GPR40-specific antibody revealed receptor expression largely localized to the plasma membrane of insulin-producing cells. Pretreating the islets with LA for 30 min followed by antisense oligonucleotide treatment for 48 h reduced the FFA(1)R/GPR40 immunoreactivity to background levels. The results demonstrate that FFA(1)R/GPR40 is inhibited by the CPT-1 inhibitor, 2BrP, and confirm that FFA(1)R/GPR40 is indeed necessary, at least in part, for fatty-acid-stimulated insulin release.
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| 49. |
- Sánchez, Elena, et al.
(författare)
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Identification of a new putative functional IL18 gene variant through an association study in systemic lupus erythematosus
- 2009
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Ingår i: Human Molecular Genetics. - : Oxford University Press (OUP). - 0964-6906 .- 1460-2083. ; 18:19, s. 3739-3748
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Tidskriftsartikel (refereegranskat)abstract
- Interleukin-18 (IL-18) is a proinflammatory cytokine that plays an important role in chronic inflammation and autoimmune disorders. In this study, we aimed to determine the potential role of the IL18 gene in SLE. To define the genetic association of the IL18 and SLE, we have genotyped nine SNPs in an independent set of Spanish cases and controls. The IL18 polymorphisms were genotyped by PCR, using a predeveloped TaqMan allele discrimination assay. Two SNPs were still significant after fine mapping of the IL18 gene. The SNP (rs360719) surviving correction for multiple tests was genotyped in two replication cohorts from Italy and Argentina. After the analysis, a significance with rs360719 C-allele remained across the sets and after the meta-analysis (Pooled OR = 1.37, 95% CI 1.21-1.54, combined P = 3.8E-07, Pc = 1.16E-06). Quantitative real-time PCR was performed to assess IL18 mRNA expression in PBMC from subjects with different IL18 rs360719 genotypes. We tested the effect of the IL18 rs360719 polymorphism on the transcription of IL18 by electrophoretic mobility shift assay and western blot. We found a significant increase in the relative expression of IL18 mRNA in individuals carrying the rs360719 C-risk allele; in addition we show that the polymorphism creates a binding site for the transcriptional factor OCT-1. These findings suggest that the novel IL18 rs360719 variant may play an important role in determining the susceptibility to SLE and it could be a key factor in the expression of the IL18 gene.
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| 50. |
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