| 1. |
- Axelsson, Lena, et al.
(författare)
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Clustering of β2-integrins on human neutrophils activates dual signaling pathways to Ptdlns 3-kinase
- 2000
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Ingår i: Experimental Cell Research. - : Elsevier BV. - 0014-4827. ; 256:1, s. 257-263
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Tidskriftsartikel (refereegranskat)abstract
- The β2-integrins on leukocytes can serve as a signaling unit during cell adhesion and locomotion, and to further clarify this important property we investigated the possible mechanisms of β2-integrin-induced activation of PtdIns 3-kinase. It has previously been demonstrated that clustering of β2-integrins activates p21(ras) by a tyrosine kinase-dependent pathway, and here we show that active p21(ras) interacts with its downstream target, PtdIns 3-kinase. Engagement of β2-integrins also activates the tyrosine kinases p58(c-fgr) and p59/61(hck) and causes them to associate with the p85 subunit of PtdIns 3-kinase. These findings suggest a mechanism whereby p58(c- fgr) and p59/61(hck) are directly involved in the activation of PtdIns 3- kinase. No coupling between p58(c-fgr) and p59/61(hck) could be detected; hence these kinases probably trigger independent but parallel signals to PtdIns 3-kinase. The effect of β2-integrin clustering on PtdIns 3-kinase activity was monitored as the activation of protein kinase B (PKB). Stimulation of PKB by β2-integrins was abolished by genistein and wortmannin but not by using methyl transferase inhibitors to abrogate the influence of p21(ras)-related proteins. Thus, even if PtdIns 3-kinase is not activated by p21(ras), it can maintain full enzyme activity due to the mentioned interaction with p58(c-fgr) or p59/61(hck). These tyrosine kinases apparently activate similar pathways that operate in parallel and therefore have the potential to substitute for each other in mediating adhesion and regulating cell locomotion. (C) 2000 Academic Press.
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| 2. |
- Borge, M. J. G., et al.
(författare)
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Proton dripline studies at ISOLDE: Ar-31 and C-9
- 2002
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Ingår i: Nuclear Physics A. - 0375-9474. ; 701, s. 373C-377C
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Konferensbidrag (refereegranskat)abstract
- In this contribution examples of the application of new technologies to disentangle the mechanism of beta-delayed multiparticle emission are given. In particular the mechanism of beta-delayed two-proton emission from Ar-31 has been resolved and proved to be sequential, a preview of C-9-decay data is discussed. (C) 2002 Elsevier Science B.V. All rights reserved.
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| 3. |
- Dib, Karim, et al.
(författare)
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Down-regulation of Rac activity during beta 2 integrin-mediated adhesion of human neutrophils
- 2003
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Ingår i: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 278:26, s. 24181-24188
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Tidskriftsartikel (refereegranskat)abstract
- In human neutrophils, beta2 integrin engagement mediated a decrease in GTP-bound Rac1 and Rac2. Pretreatment of neutrophils with LY294002 or PP1 (inhibiting phosphatidylinositol 3-kinase (PI 3-kinase) and Src kinases, respectively) partly reversed the beta2 integrin-induced down-regulation of Rac activities. In contrast, beta2 integrins induced stimulation of Cdc42 that was independent of Src family members. The PI 3-kinase dependence of the beta2 integrin-mediated decrease in GTP-bound Rac could be explained by an enhanced Rac-GAP activity, since this activity was blocked by LY204002, whereas PP1 only had a minor effect. The fact that only Rac1 but not Rac2 (the dominating Rac) redistributed to the detergent-insoluble fraction and that it was independent of GTP loading excludes the possibility that down-regulation of Rac activities was due to depletion of GTP-bound Rac from the detergent-soluble fraction. The beta2 integrin-triggered relocalization of Rac1 to the cytoskeleton was enabled by a PI 3-kinase-induced dissociation of Rac1 from LyGDI. The dissociations of Rac1 and Rac2 from LyGDI also explained the PI 3-kinase-dependent translocations of Rac GTPases to the plasma membrane. However, these accumulations of Rac in the membrane, as well as that of p47phox and p67phox, were also regulated by Src tyrosine kinases. Inasmuch as Rac GTPases are part of the NADPH oxidase and the respiratory burst is elicited in neutrophils adherent by beta2 integrins, our results indicate that activation of the NADPH oxidase does not depend on the levels of Rac-GTP but instead requires a beta2 integrin-induced targeting of the Rac GTPases as well as p47phox and p67phox to the plasma membrane.
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| 4. |
- Ek, Fredrik, et al.
(författare)
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Aromatic allylation via diazotization: Metal-free C-C bond formation
- 2002
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Ingår i: Journal of Organic Chemistry. - : American Chemical Society (ACS). - 1520-6904 .- 0022-3263. ; 67:18, s. 6376-6381
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Tidskriftsartikel (refereegranskat)abstract
- A new method for the synthesis of allyl aromatic compounds not involving any metal-containing reagent or catalyst has been developed. Arylamines substituted with a large number of different substituents were converted via diazotizative deamination with tert-butyl nitrite in allyl bromide and acetonitrile to the corresponding allyl aromatic compounds. The allylation reaction was found to be suitable for larger scale synthesis due to short reaction times, a nonextractive workup, and robustness toward moisture, air, and type of solvent.
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| 5. |
- Fynbo, H. O. U., et al.
(författare)
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The beta 2p decay mechanism of Ar-31
- 2000
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Ingår i: Nuclear Physics A. - 0375-9474. ; 677, s. 38-60
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Tidskriftsartikel (refereegranskat)abstract
- We have measured the beta-decay of Ar-31 with a high granularity setup sensitive to multiparticle decay branches. Two-proton emission is observed from the isobaric analog state in Cl-31 to the four lowest states in P-29 and furthermore from a large number of states fed in Gamow-Teller transitions. The mechanism of two-proton emission is studied via energy and angular correlations between the two protons. In all cases the mechanism is found to be sequential yielding information about states in S-30 up to 8 MeV excitation energy. Improved data on the beta-delayed one-proton branches together with the two-proton data provide precise information about the beta-strength distribution up to 15 MeV excitation energy.
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| 6. |
- Markenroth, Karin, 1973, et al.
(författare)
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Crossing the dripline to N-11 using elastic resonance scattering
- 2000
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Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993. ; 6203:3
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Tidskriftsartikel (refereegranskat)abstract
- The level structure of the unbound nucleus N-11 has been studied by C-10+p elastic resonance scattering in inverse geometry with the LISE3 spectrometer at GANIL, using a C-10 beam with an energy of 9.0 MeV/ nucleon. An additional measurement was done at the A1200 spectrometer at MSU. The excitation function above the C-10+p threshold has been determined up to 5 MeV. A potential-model analysis revealed three resonance states at energies 1.27(-0.05)(+0.18) MeV (Gamma = 1.44 +/- 0.2 MeV), 2.01(-0.05)(+0.15) MeV (Gamma = 0.84 +/- 0.2 MeV), and 3.75 +/- 0.05 MeV (Gamma = 0.60 +/- 0.05 MeV) with the spin-parity assignments I-pi=1/2+,1/2,-,5/2+, respectively. Hence, N-11 is shown to have a ground state parity inversion completely analogous to its mirror partner Be-11. A narrow resonance in the excitation function at 4.33 +/- 0.05 MeV was also observed and assigned spin parity 3/2-.
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| 7. |
- Nyberg Oskarsson, Gunilla, 1948-
(författare)
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Le mouvement pentecôtiste - une communauté alternative au sud du Burundi 1935-1960
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis is a contribution to a hitherto neglected area of research: The African Pentecostal Churches, that do not belong to those called African Indigenous Churches (AICs). It is a case study from the perspective of southern Burundi, the periphery of the ancient kingdom.The Pentecostal Movement in Burundi was born in the encounter between Swedish Pentecostal missionaries and the population in the southern part of the country. This study highlights what happened in that encounter.The thesis consists of six parts. The first is a survey of the Pentecostal Movement in Sweden. The diachronic structure of parts two to five focuses on the development within the Burundian Pentecostal Churches and their relationship to the Burundian society 1935-1960. In the sixth part the diachronic approach is augmented by structural analyses, showing how aspects in the Pentecostal Movement developed.The Pentecostal missionaries accepted in part the traditional world view, the belief in a spiritual world and non-rational explanations to misfortunes in life. They encouraged the Burundians to do spiritual experiences, and especially the baptism in the Holy Ghost. The Burundian evangelists and church elders played a decisive role. It was their task to reformulate the Pentecostal message in Kirundi, which was not spoken by the missionaries. They moulded the message into a Burundian Pentecostal message, at the same time respecting the teaching of the early missionaries.They succeeded in doing that so well that the Pentecostal Movement became a popular movement, in certain places the dominating Christian denomination, in spite of the parallel work done by the Catholic Church, encouraged and supported by the Belgian state.This thesis builds on material taken mainly from unpublished sources from archives in Burundi, Sweden, Rome, Great Britain and Denmark. These are supplemented by interviews, most of them made by the author.
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| 8. |
- Rodushkin, Ilya, et al.
(författare)
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Determination of 60 elements in whole blood by sector field inductively coupled plasma mass spectrometry
- 2000
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Ingår i: Journal of Analytical Atomic Spectrometry. - : Royal Society of Chemistry (RSC). - 0267-9477 .- 1364-5544. ; 15:8, s. 937-944
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Tidskriftsartikel (refereegranskat)abstract
- A method is described for the determination of 60 elements in whole blood, using a double-focusing ICP-MS instrument. Microwave-assisted digestion in low-volume PFA vessels resulted in 10-fold sample dilution. External calibration with matrix-matched standards was used for quantification. Different factors affecting detection limits are discussed. The performance of the method for the determination of environmentally relevant concentrations was evaluated using a whole blood reference material and intercomparison samples. Owing to high instrumental detection power and low preparation blanks, 57 elements could be detected in the bovine whole blood reference material (IAEA A-13). Trace element leaching from commercially available blood sampling tubes made of glass was shown to be a serious contamination factor. Concentrations obtained for three calf blood samples taken under `metal-free' conditions are presented.
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| 9. |
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