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Sökning: WFRF:(Kreis M)

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1.
  • Aad, G, et al. (författare)
  • 2015
  • swepub:Mat__t
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2.
  • Faatz, B., et al. (författare)
  • Simultaneous operation of two soft x-ray free-electron lasers driven by one linear accelerator
  • 2016
  • Ingår i: New Journal of Physics. - : IOP Publishing. - 1367-2630. ; 18
  • Tidskriftsartikel (refereegranskat)abstract
    • Extreme-ultraviolet to x-ray free-electron lasers (FELs) in operation for scientific applications are up to now single-user facilities. While most FELs generate around 100 photon pulses per second, FLASH at DESY can deliver almost two orders of magnitude more pulses in this time span due to its superconducting accelerator technology. This makes the facility a prime candidate to realize the next step in FELs-dividing the electron pulse trains into several FEL lines and delivering photon pulses to several users at the same time. Hence, FLASH has been extended with a second undulator line and self-amplified spontaneous emission (SASE) is demonstrated in both FELs simultaneously. FLASH can now deliver MHz pulse trains to two user experiments in parallel with individually selected photon beam characteristics. First results of the capabilities of this extension are shown with emphasis on independent variation of wavelength, repetition rate, and photon pulse length.
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3.
  • Buunen, M, et al. (författare)
  • COLOR II. A randomized clinical trial comparing laparoscopic and open surgery for rectal cancer.
  • 2009
  • Ingår i: Danish medical bulletin. - 1603-9629 .- 0907-8916. ; 56:2, s. 89-91
  • Tidskriftsartikel (refereegranskat)abstract
    • INTRODUCTION: Laparoscopic resection of rectal cancer has been proven efficacious but morbidity and oncological outcome need to be investigated in a randomized clinical trial. Trial design: Non-inferiority randomized clinical trial. METHODS: The COLOR II trial is an ongoing international randomized clinical trial. Currently 27 hospitals from Europe, South Korea and Canada are including patients. The primary endpoint is loco-regional recurrence rate three years post-operatively. Secondary endpoints cover quality of life, overall and disease free survival, post-operative morbidity and health economy analysis. RESULTS: By July 2008, 27 hospitals from the Netherlands, Belgium, Germany, Sweden, Spain, Denmark, South Korea and Canada had included 739 patients. The intra-operative conversion rate in the laparoscopic group was 17%. Distribution of age, location of the tumor and radiotherapy were equal in both treatment groups. Most tumors are located in the mid-rectum (41%). CONCLUSION: Laparoscopic surgery in the treatment of rectal cancer is feasible. The results and safety of laparoscopic surgery in the treatment of rectal cancer remain unknown, but are subject of interim analysis within the COLOR II trial. Completion of inclusion is expected by the end of 2009. Trial registration: Clinicaltrials.gov, identifier: NCT00297791 (www.clinicaltrials.gov).
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5.
  • Elsasser, M., et al. (författare)
  • Organic molecular markers and signature from wood combustion particles in winter ambient aerosols: aerosol mass spectrometer (AMS) and high time-resolved GC-MS measurements in Augsburg, Germany
  • 2012
  • Ingår i: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 12:14, s. 6113-6128
  • Tidskriftsartikel (refereegranskat)abstract
    • The impact of wood combustion on ambient aerosols was investigated in Augsburg, Germany during a winter measurement campaign of a six-week period. Special attention was paid to the high time resolution observations of wood combustion with different mass spectrometric methods. Here we present and compare the results from an Aerodyne aerosol mass spectrometer (AMS) and gas chromatographic - mass spectrometric (GC-MS) analysed PM1 filters on an hourly basis. This includes source apportionment of the AMS derived organic matter (OM) using positive matrix factorisation (PMF) and analysis of levoglucosan as wood combustion marker, respectively. During the measurement period nitrate and OM mass are the main contributors to the defined submicron particle mass of AMS and Aethalometer with 28% and 35%, respectively. Wood combustion organic aerosol (WCOA) contributes to OM with 23% on average and 27% in the evening and night time. Conclusively, wood combustion has a strong influence on the organic matter and overall aerosol composition. Levoglucosan accounts for 14% of WCOA mass with a higher percentage in comparison to other studies. The ratio between the mass of levoglucosan and organic carbon amounts to 0.06. This study is unique in that it provides a one-hour time resolution comparison between the wood combustion results of the AMS and the GC-MS analysed filter method at a PM1 particle size range. The comparison of the concentration variation with time of the PMF WCOA factor, levoglucosan estimated by the AMS data and the levoglucosan measured by GC-MS is highly correlated (R-2 = 0.84), and a detailed discussion on the contributors to the wood combustion marker ion at mass-to-charge ratio 60 is given. At the end, both estimations, the WCOA factor and the levoglucosan concentration estimated by AMS data, allow to observe the variation with time of wood combustion emissions (gradient correlation with GC-MS levoglucosan of R-2 = 0.84). In the case of WCOA, it provides the estimated magnitude of wood combustion emission. Quantitative estimation of the levoglucosan concentration from the AMS data is problematic due to its overestimation in comparison to the levoglucosan measured by the GC-MS.
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6.
  • Ruppel, M. M., et al. (författare)
  • Organic Compounds, Radiocarbon, Trace Elements and Atmospheric Transport Illuminating Sources of Elemental Carbon in a 300-Year Svalbard Ice Core
  • 2023
  • Ingår i: Journal of Geophysical Research - Atmospheres. - 2169-897X .- 2169-8996. ; 128:16
  • Tidskriftsartikel (refereegranskat)abstract
    • Black carbon (BC) particles produced by incomplete combustion of biomass and fossil fuels warm the atmosphere and decrease the reflectivity of snow and ice, hastening their melt. Although the significance of BC in Arctic climate change is widely acknowledged, observations on its deposition and sources are few. We present BC source types in a 300-year (1700-2005) Svalbard ice core by analysis of particle-bound organic compounds, radiocarbon, and trace elements. According to the radiocarbon results, 58% of the deposited elemental carbon (EC, thermal-optical proxy of BC) is of non-fossil origin throughout the record, while the organic compounds suggest a higher percentage (68%). The contribution of fossil fuels to EC is suggested to have been elevated between 1860 and 1920, particularly based on the organics and trace element data. A second increase in fossil fuel sources seems to have occurred near the end of the record: according to radiocarbon measurements between 1960 and 1990, while the organics and trace element data suggest that the contribution of fossil fuels has increased since the 1970s to the end of the record, along with observed increasing EC deposition. Modeled atmospheric transport between 1948 and 2004 shows that increasing EC deposition observed at the glacier during that period can be associated with increased atmospheric transport from Far East Asia. Further observational BC source data are essential to help target climate change mitigation efforts. The combination of robust radiocarbon with organic compound analyses requiring low sample amounts seems a promising approach for comprehensive Arctic BC source apportionment.
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8.
  • Campistol, Josep M., et al. (författare)
  • Sirolimus therapy after early cyclosporine withdrawal reduces the risk for cancer in adult renal transplantation
  • 2006
  • Ingår i: Journal of the American Society of Nephrology. - 1046-6673 .- 1533-3450. ; 17:2, s. 581-589
  • Tidskriftsartikel (refereegranskat)abstract
    • Sirolimus (SRL) is a mammalian target of rapamycin inhibitor that, in contrast to cyclosporine (CsA), has been shown to inhibit rather than promote cancers in experimental models. At 3 mo +/- 2 wk after renal transplantation, 430 of 525 enrolled patients were randomly assigned to remain on SRL-CsA-steroids (ST) or to have CsA withdrawn and SRL troughs increased two-fold (SRL-ST). Median times to first skin and nonskin malignancies were compared between treatments using a survival analysis. Mean annualized rates of skin malignancy were calculated, and the relative risk was determined using a Poisson model. Malignancy-free survival rates for nonskin malignancies were compared using Kaplan-Meier estimates and the log-rank test. At 5 yr, the median time to a first skin carcinoma was delayed (491 versus 1126 d; log-rank test, P = 0.007), and the risk for an event was significantly lower with SRL-ST therapy (relative risk SRL-ST to SRL-CsA-ST 0.346; 95% confidence interval 0.227 to 0.526; P < 0.001, intention-to-treat analysis). The relative risks for both basal and squamous cell carcinomas were significantly reduced. Kaplan-Meier estimates of nonskin cancer were 9.6 versus 4.0% (SRL-CsA-ST versus SRL-ST; P = 0.032, intention-to-treat analysis). Nonskin cancers included those of the lung, larynx, oropharynx, kidney, gastrointestinal tract, prostate, breast, thyroid, and cervix as well as glioma, liposarcoma, astrocytoma, leukemia, lymphoma, and Kaposi's sarcoma. Patients who received SRL-based, calcineurin inhibitor-free therapy after CsA withdrawal at month 3 had a reduced incidence of both skin and nonskin malignancies at 5 yr after renal transplantation compared with those who received SRL therapy combined with CsA. Longer follow-up and additional trials are needed to confirm these promising results.
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9.
  • Kasiske, Bertram L., et al. (författare)
  • KDIGO clinical practice guideline for the care of kidney transplant recipients: a summary
  • 2010
  • Ingår i: Kidney International. - : Elsevier BV. - 1523-1755 .- 0085-2538. ; 77:4, s. 299-311
  • Tidskriftsartikel (refereegranskat)abstract
    • The 2009 Kidney Disease: Improving Global Outcomes (KDIGO) clinical practice guideline on the monitoring, management, and treatment of kidney transplant recipients is intended to assist the practitioner caring for adults and children after kidney transplantation. The guideline development process followed an evidence-based approach, and management recommendations are based on systematic reviews of relevant treatment trials. Critical appraisal of the quality of the evidence and the strength of recommendations followed the Grades of Recommendation Assessment, Development, and Evaluation (GRADE) approach. The guideline makes recommendations for immunosuppression and graft monitoring, as well as prevention and treatment of infection, cardiovascular disease, malignancy, and other complications that are common in kidney transplant recipients, including hematological and bone disorders. Limitations of the evidence, especially the lack of definitive clinical outcome trials, are discussed and suggestions are provided for future research. This summary includes a brief description of methodology and the complete guideline recommendations but does not include the rationale and references for each recommendation, which are published elsewhere. Kidney International (2010) 77, 299-311; doi: 10.1038/ki.2009.377; published online 21 October 2009
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10.
  • Yttri, K. E., et al. (författare)
  • An intercomparison study of analytical methods used for quantification of levoglucosan in ambient aerosol filter samples
  • 2015
  • Ingår i: Atmospheric Measurement Techniques. - : Copernicus GmbH. - 1867-1381 .- 1867-8548. ; 8:1, s. 125-147
  • Tidskriftsartikel (refereegranskat)abstract
    • The monosaccharide anhydrides (MAs) levoglucosan, galactosan and mannosan are products of incomplete combustion and pyrolysis of cellulose and hemicelluloses, and are found to be major constituents of biomass burning (BB) aerosol particles. Hence, ambient aerosol particle concentrations of levoglucosan are commonly used to study the influence of residential wood burning, agricultural waste burning and wildfire emissions on ambient air quality. A European-wide intercomparison on the analysis of the three monosaccharide anhydrides was conducted based on ambient aerosol quartz fiber filter samples collected at a Norwegian urban background site during winter. Thus, the samples' content of MAs is representative for BB particles originating from residential wood burning. The purpose of the intercomparison was to examine the comparability of the great diversity of analytical methods used for analysis of levoglucosan, mannosan and galactosan in ambient aerosol filter samples. Thirteen laboratories participated, of which three applied high-performance anion-exchange chromatography (HPAEC), four used high-performance liquid chromatography (HPLC) or ultra-performance liquid chromatography (UPLC) and six resorted to gas chromatography (GC). The analytical methods used were of such diversity that they should be considered as thirteen different analytical methods. All of the thirteen laboratories reported levels of levoglucosan, whereas nine reported data for mannosan and/or galactosan. Eight of the thirteen laboratories reported levels for all three isomers. The accuracy for levoglucosan, presented as the mean percentage error (PE) for each participating laboratory, varied from -63 to 20 %; however, for 62% of the laboratories the mean PE was within +/- 10 %, and for 85% the mean PE was within +/- 20 %. For mannosan, the corresponding range was 60 to 69 %, but as for levoglucosan, the range was substantially smaller for a subselection of the laboratories; i.e. for 33% of the laboratories the mean PE was within +/- 10 %. For galactosan, the mean PE for the participating laboratories ranged from 84 to 593 %, and as for mannosan 33% of the laboratories reported a mean PE within +/- 10 %. The variability of the various analytical methods, as defined by their minimum and maximum PE value, was typically better for levoglucosan than for mannosan and galactosan, ranging from 3.2 to 41% for levoglucosan, from 10 to 67% for mannosan and from 6 to 364% for galactosan. For the levoglucosan to mannosan ratio, which may be used to assess the relative importance of softwood versus hardwood burning, the variability only ranged from 3.5 to 24 %. To our knowledge, this is the first major intercomparison on analytical methods used to quantify monosaccharide anhydrides in ambient aerosol filter samples conducted and reported in the scientific literature. The results show that for levoglucosan the accuracy is only slightly lower than that reported for analysis of SO42- (sulfate) on filter samples, a constituent that has been analysed by numerous laboratories for several decades, typically by ion chromatography and which is considered a fairly easy constituent to measure. Hence, the results obtained for levoglucosan with respect to accuracy are encouraging and suggest that levels of levoglucosan, and to a lesser extent mannosan and galactosan, obtained by most of the analytical methods currently used to quantify monosaccharide anhydrides in ambient aerosol filter samples, are comparable. Finally, the various analytical methods used in the current study should be tested for other aerosol matrices and concentrations as well, the most obvious being summertime aerosol samples affected by wildfires and/or agricultural fires.
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