| 1. |
- Auvray, Xavier, 1986, et al.
(författare)
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The effect gas composition during thermal aging on the dispersion and NO oxidation activity over Pt/Al2O3 catalysts
- 2013
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Ingår i: Applied Catalysis B: Environmental. - : Elsevier BV. - 0926-3373 .- 1873-3883. ; 129, s. 517-527
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Tidskriftsartikel (refereegranskat)abstract
- The aging of a model 1 wt.% Pt/Al2O3 catalyst was performed stepwise under different reactive atmosphere to study the evolution of metal dispersion and NO oxidation activity. After each aging step the dispersion was evaluated by CO chemisorptions and the activity of the catalyst for NO oxidation was measured using 500 ppm NO and 8%O-2 diluted in Ar. After a degreening step at 500 degrees C, aging was performed at 600, 700,800 and 900 degrees C. Five wash-coated cordierite monoliths were aged in Ar, 10% O-2, 1% H-2 30 ppm SO2 and 30 ppm SO2 + 10% O-2, respectively. The general trend showed a linear decrease in dispersion when increasing the aging temperature for the lower aging temperatures and for the highest ones the dispersion levels off. When the platinum dispersion decreased the NO oxidation activity increased, due to that the reaction is structure sensitive. H-2 seemed to hinder sintering at low aging temperature. Interestingly, after aging in 10% oxygen at 600 degrees C the NO oxidation activity was significantly higher compared to the Ar aged sample, although the dispersions were similar. Aging in oxygen at higher temperatures resulted in a decrease of dispersion and a slightly decreasing NO oxidation activity. Moreover lower dispersion limit was reached with oxygen aging. Aging in SO2 provoked a severe dispersion drop at low aging temperature meanwhile the activity increased only moderately. However, activity kept increasing with further treatments at higher temperature. The combination of O-2 and SO2 enabled to decrease rapidly the dispersion and to greatly enhance the catalytic NO oxidation activity after the first aging step at only 600 degrees C. The best overall conversion was obtained for the catalyst treated with this mixture after aging at 800 degrees C. A 22-h aging at 250 degrees C in a mixture containing 500 ppm NO, 10% O-2 and 30 ppm SO2 led to a significant decrease of Pt dispersion, which shows the ability of SO2 to promote platinum sintering already 250 degrees C. The low temperature sintering was confirmed with STEM measurements. Several larger particles were observed, but also many small particles remained. Thus the SO2 + O-2 induced low temperature sintering results in a large variation of particle sizes. This treatment resulted in an increase of the maximum NO conversion (after reduction of the sample) from 45% to 76%. The different aging experiments show that it is beneficial to add SO2 during aging and the reason is the increased particle size, but also a clear chemical effect was observed.
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| 2. |
- Jonsson, Rasmus, 1989, et al.
(författare)
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Chemical poisoning by zinc and phosphorous of Pt/Ba/Al2O3 NOx storage catalysts
- 2019
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Ingår i: Applied Catalysis A: General. - : Elsevier BV. - 1873-3875 .- 0926-860X. ; 571, s. 158-169
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Tidskriftsartikel (refereegranskat)abstract
- The effects of phosphorous and zinc on the performance of Pt/Ba/Al2O3 catalysts were investigated through wet impregnation of ammonium phosphate and zinc acetate aqueous solutions. Six different sample combinations were studied; 1 wt-% P, 1 wt-% Zn, 1 wt-% P with 1 wt-% Zn, 2 wt-% P, 2 wt-% Zn, 2 wt-% P with 2 wt-% Zn. NOx storage and reduction (NSR) activity and NO2 temperature programmed desorption (TPD) profiles were measured before and after impregnation of P and Zn. Samples containing P performed significantly worse than samples only containing Zn in both NSR activity and TPD measurements. The increased NOx slip during lean phase in activity measurements for P-poisoned samples is mainly related to an increased slip of NO2. This was found for both NO and NO2 in the gas feed during lean phase and suggests that it is mainly the storage component that is poisoned and not the noble metal. Furthermore, the combination (1 wt-% P and 1 wt-% Zn) proved to result in slightly worse performance than only 1 wt-% P, however this was not the case for samples containing 2 wt-%, where the addition of zinc reduced the negative effect of phosphorous. Measurements from NO2-TPD experiments showed that NOx release at low temperature was not affected by the addition of P, while desorption in the temperature range 425–475 °C was significantly reduced. It can therefore be concluded that the poisoning mainly is related to barium NOx storage sites and not to alumina sites. Moreover, X-ray diffraction measurements indicate that some of the barium species are affected by phosphorous. Images from scanning transmission electron microscopy (STEM) and energy-dispersive X-ray spectroscopy (EDX) mapping were in line with the results seen in both the activity tests and NO2-TPD experiments. Phosphorous was concentrated at the same position as barium in the observed images, whereas zinc was more evenly distributed over the surface. For the sample with both 2 wt-% P and 2 wt-% Zn, X-ray photoelectron spectroscopy measurements indicate that Zn and P have a low interaction and this suggests that most of the zinc and phosphorous are separated. However, STEM-EDX showed agglomerates of some zinc and phosphorous, which could be zinc phosphates. This is a plausible explanation of the decreased deactivation observed after introducing 2 wt-% Zn compared to the sample only containing 2 wt-% P.
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| 3. |
- Jonsson, Rasmus, 1989, et al.
(författare)
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Gas-phase phosphorous poisoning of a Pt/Ba/Al2O3 NOx storage catalyst
- 2018
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Ingår i: Catalysts. - : MDPI AG. - 2073-4344. ; 8:4
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Tidskriftsartikel (refereegranskat)abstract
- The effect of phosphorous exposure on the NO x storage capacity of a Pt/Ba/Al 2 O 3 catalyst coated on a ceramic monolith substrate has been studied. The catalyst was exposed to phosphorous by evaporating phosphoric acid in presence of H 2 O and O 2 . The NOx storage capacity was measured before and after the phosphorus exposure and a significant loss of the NO x storage capacity was detected after phosphorous exposure. The phosphorous poisoned samples were characterized by X-ray photoelectron spectroscopy (XPS), environmental scanning electron microscopy (ESEM), N 2 -physisorption and inductive coupled plasma atomic emission spectroscopy (ICP-AES). All characterization methods showed an axial distribution of phosphorous ranging from the inlet to the outlet of the coated monolith samples with a higher concentration at the inlet of the samples. Elemental analysis, using ICP-AES, confirmed this distribution of phosphorous on the catalyst surface. The specific surface area and pore volume were significantly lower at the inlet section of the monolith where the phosphorous concentration was higher, and higher at the outlet where the phosphorous concentration was lower. The results from the XPS and scanning electron microscopy (SEM)-energy dispersive X-ray (EDX) analyses showed higher accumulation of phosphorus towards the surface of the catalyst at the inlet of the monolith and the phosphorus was to a large extent present in the form of P 4 O 10 . However, in the middle section of the monolith, the XPS analysis revealed the presence of more metaphosphate (PO 3 – ). Moreover, the SEM-EDX analysis showed that the phosphorous to higher extent had diffused into the washcoat and was less accumulated at the surface close to the outlet of the sample
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| 4. |
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| 5. |
- Breimer, Lars H., et al.
(författare)
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Immune checkpoint inhibitors of the PD-1/PD-L1-axis in non-small cell lung cancer : promise, controversies and ambiguities in the novel treatment paradigm
- 2020
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Ingår i: Scandinavian Journal of Clinical and Laboratory Investigation. - : Taylor & Francis. - 0036-5513 .- 1502-7686. ; 80:5, s. 360-369
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Forskningsöversikt (refereegranskat)abstract
- Immune checkpoint inhibitors (ICIs) have received much attention not least for melanoma since the award of the Nobel prize in 2018. Here, we review the current state of knowledge about the use of these monoclonal antibodies (mAbs) in non-small cell lung cancer (NSCLC). These drugs have generally been conditionally approved on limited early data and there are few long-term follow-up data from randomized clinical trials. The effect observed for NSCLC thus far is, on average, moderately better than that obtained with chemotherapy. Severe side-effects are more common than might have been expected. The drugs themselves are expensive and are associated with time-consuming histopathologic testing even though the predictive value of these tests can be discussed. In addition, monitoring for side-effects involves increased workload and budgetary expense for clinical chemistry laboratories. Here, we review and summarize the current knowledge, controversies and ambiguities of ICIs for the treatment of NSCLC.
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| 6. |
- Czajkowski, Marek, 1989-, et al.
(författare)
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Intressekonflikter påverkar den medicinska forskningen i alla led : [Conflicts of interest are ever present in medical research]
- 2023
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Ingår i: Läkartidningen. - : Läkartidningen Förlag AB. - 0023-7205 .- 1652-7518. ; 120:20/21
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Tidskriftsartikel (refereegranskat)abstract
- Evidensbaserad vård förutsätter opartiska underlag.Intressekonflikter är ständigt närvarande i medicinsk forskning, och mycket har gjorts för att de ska redovisas på ett transparent sätt.Enbart transparens löser dock inte problemet.Studier tyder på att finansiella intressekonflikter i kliniska prövningar påverkar både forskningsfråga, metod, resultat och tolkning.Icke-finansiella intressekonflikter kan också finnas, men är mindre studerade.Det behövs mer forskning om intressekonflikter, deras konsekvenser och hur de ska hanteras.
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| 7. |
- Grönqvist, Helena, 1975-, et al.
(författare)
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Fifteen Challenges in Establishing a Multidisciplinary Research Program on eHealth Research in a University Setting : A Case Study
- 2017
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Ingår i: Journal of Medical Internet Research. - : JMIR Publications Inc.. - 1438-8871. ; 19:5
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND:U-CARE is a multidisciplinary eHealth research program that involves the disciplines of caring science, clinical psychology, health economics, information systems, and medical science. It was set up from scratch in a university setting in 2010, funded by a governmental initiative. While establishing the research program, many challenges were faced. Systematic documentation of experiences from establishing new research environments is scarce.OBJECTIVE:The aim of this paper was to describe the challenges of establishing a publicly funded multidisciplinary eHealth research environment.METHODS:Researchers involved in developing the research program U-CARE identified challenges in the formal documentation and by reflecting on their experience of developing the program. The authors discussed the content and organization of challenges into themes until consensus was reached.RESULTS:The authors identified 15 major challenges, some general to establishing a new research environment and some specific for multidisciplinary eHealth programs. The challenges were organized into 6 themes: Organization, Communication, Implementation, Legislation, Software development, and Multidisciplinarity.CONCLUSIONS:Several challenges were faced during the development of the program and several accomplishments were made. By sharing our experience, we hope to help other research groups embarking on a similar journey to be prepared for some of the challenges they are likely to face on their way.
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| 8. |
- Klingstedt, Marie-Louise, 1960-
(författare)
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Mönster av anpassningsproblem hos flickor och unga kvinnor på särskilda ungdomshem : En fyraårig uppföljningsstudie
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Den här avhandlingen handlar om flickor och unga kvinnor mellan 12 och 20 år som har vårdats på särskilda ungdomshem på grund av eget beteende. Avhandling består av två tvärsnittsstudier och en uppföljningsstudie. Huvudsyftet var att utforska flickornas och de unga kvinnornas mönster av externaliserande och internaliserande problem vid inskrivningstillfället på särskilda ungdomshem samt att undersöka om olika mönster av anpassningsproblem vid intagningen var relaterade till olika återanpassning fyra år senare. Det holistisk interaktionistiska perspektivet, livsloppteori och utvecklingspsykopatologi användes som övergripande teorier. För att utforska anpassningsproblemen vid inskrivningstillfället användes befintliga ADAD-intervjuer som utförs vid inskrivning. Uppföljningen utfördes med hjälp av telefonintervju och intervjuguiden anpassades till intervjuformen genom att använda igenkännande ADAD-frågor och ”positiva” frågor. I linje med det holistisk interaktionistiska perspektivet användes personorienterade metoder för att utforska mönster av anpassningsproblem. I uppföljningsstudien kombinerades en personorienterad och en variabel-orienterade metod. I Studie 1 identifierades psykometriskt lämpliga skalor utifrån dimensionsanalyser av de ungdomsrapporterade svaren i ADAD. Totalt identifierades 11 index med god konstruktvaliditet och god intern konsistens för fem olika problemområden. I Studie 2 utforskades mönster av externaliserande och internaliserande problem var för sig utifrån de index som utformades i studie 1. Den valda externaliserande klusterlösning bestod av nio kluster varav två inkluderade multiproblem. För de internaliserande problem valdes sjuklusterlösningen, två multiproblemkluster återfanns även i denna klusterlösning. Externaliserande och internaliserande syndrom tenderade att förekomma tillsammans hos samma individer i klustren med Låga problem enbart. Men också bland flickor och unga kvinnor med aggressivt beteende, då de tenderade att ha internaliserande problem som ångest, depression, somatiska problem och parasuiciadal problem. Detta skulle kunna tyda på "komorbiditet", d.v.s "samsjuklighet", mellan aggressiva externaliserande syndrom och internaliserande syndrom.I studie 3 undersöktes om olika mönster av anpassningsproblem vid intagning till särskilda ungdomshem var relaterade till social återanpassning fyra år senare. Resultatet visade att unga kvinnor i Missbrukssyndromet och Multipla-problemsyndrom 1 (Droger och egendom/drogbrott) rapporterade allvarliga fortsatta problem med narkotikamissbruk fyra år efter intagning. Allvarligast problem hade Multipla problemsyndrom 1 som injicerade droger samt också i hög utsträckning blivit återintagna i tvångsvård. Sammanfattningsvis har denna avhandling både teoretisk och praktisk betydelse dels då resultaten ger information om flickornas och de unga kvinnornas hela problembild utifrån ADAD, något som bör beaktas vid val av behandlingshem, vård och planering. Av vikt är också studie 3, där resultaten definieras utifrån viktiga livsomständigheter, t.ex. familje- och sociala relationer samt brottslighet, alkohol- och drogmissbruk och återfall i tvångsvård fyra år efter intagning till särskilda ungdomshem. Denna studie indikerar vilka syndrom som har de största utvecklingspotentialen gällande vård och resurser. Slutligen skulle studie 1 kunna vägleda framtida bedömningsmetoder, d.v.s. användning av de ungdomsrapporterade svaren i ADAD som visade sig vara vetenskapligt användbara.
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| 9. |
- Li, Mei, 1970-, et al.
(författare)
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A population-based study on time trends of hemoglobin in primary care comparing prediagnostic colorectal cancer patients vs age- and sex-matched controls
- 2021
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Ingår i: Scandinavian Journal of Gastroenterology. - : Taylor & Francis. - 0036-5521 .- 1502-7708. ; 56:3, s. 266-273
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Some 40% of colorectal cancer (CRC) patients present with anemia. Temporal trends of gradually decreasing Hb are suggested as a supplementary diagnostic tool for CRC. We set out to explore this concept in a strictly defined population.METHODS: A laboratory database identified patients ≥40 years that had ≥1 Hb test reported from primary care, Örebro county in 2000-17. Linkage to the Swedish Colorectal Cancer Registry identified patients diagnosed with CRC. Other primary care patients served as controls (1:10), matched by age and sex. Prediagnostic Hb in cases and controls were compared and temporal trajectories of Hb modelled using a nonlinear three-parameter logistic function.RESULTS: primary care was surprisingly low, and was ≥50% annually only in octogenarians.CONCLUSION: The findings indicate a potential for Hb trends to inform the diagnostic process of CRC but whether it will translate into any clinical advantage is yet uncertain.
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| 10. |
- Lööv, Anna, 1990-, et al.
(författare)
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Diagnostic accuracy for colorectal cancer of a quantitative faecal immunochemical test in symptomatic primary care patients : a study protocol
- 2022
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Ingår i: Diagnostic and prognostic research. - : BioMed Central (BMC). - 2397-7523. ; 6:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: There is increasing evidence supporting the use of faecal immunochemical tests (FIT) in patients reporting symptoms associated with colorectal cancer (CRC), but most studies until now have focused on selected subjects already referred for investigation. We therefore set out to determine the accuracy and predictive values of FIT in a primary care population.METHOD: A prospective, multicentre, single-gated comparative diagnostic study on quantitative FIT in patients aged 40 years and above presenting in primary care with symptoms associated with CRC will be conducted. Patients representing the whole spectrum of severity of such symptoms met with in primary care will be eligible and identified by GPs. Participants will answer a short form on symptoms during the last month. They will provide two faecal samples from two separate days. Analyses will be performed within 5 days (QuikRead go®, Aidian Oy). The analytical working range is 10-200 μg Hb/g faeces. Reference test will be linked to the Swedish Colorectal Cancer Registry up to 2 years after inclusion. Accuracy, area under ROC curves, and predictive values will be calculated for one FIT compared to the highest value of two FIT and at cutoff < 10, 10-14.9, 15-19.9 and ≥ 20 μg Hb/g faeces. Subgroup analyses will be conducted for patients with anaemia and those reporting rectal bleeding. A model-based cost-effectiveness analysis based on the clinical accuracy study will be performed. Based on previous literature, we hypothesized that the sensitivity of the highest value of two FIT at cutoff 10 μg Hb/g faeces will be 95% (95% CI + / - 15%). The prevalence of CRC in the study population was estimated to be 2%, and the rate of non-responders to be 1/6. In all, 3000 patients will be invited at 30 primary care centres.DISCUSSION: This study will generate important clinical real-life structured data on accuracy and predictive values of FIT in the most critical population for work-up of CRC, i.e. patients presenting with at times ambiguous symptoms in primary care. It will help establish the role of FIT in this large group.
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