| 1. |
- Andreasson, Håkan, 1966, et al.
(författare)
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On the rotation curves for axially symmetric disk solutions of the Vlasov-Poisson system
- 2015
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Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 446:4, s. 3932-3942
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Tidskriftsartikel (refereegranskat)abstract
- A large class of flat axially symmetric solutions to the Vlasov–Poisson system is constructed with the property that the corresponding rotation curves are approximately flat, slightly decreasing or slightly increasing. The rotation curves are compared with measurements from real galaxies and satisfactory agreement is obtained. These facts raise the question whether the observed rotation curves for disc galaxies may be explained without introducing dark matter. Furthermore, it is shown that for the ansatz we consider stars on circular orbits do not exist in the neighbourhood of the boundary of the steady state.
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| 2. |
- Andreasson, Håkan, 1966, et al.
(författare)
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Static solutions to the Einstein-Vlasov system with a nonvanishing cosmological constant
- 2015
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Ingår i: SIAM Journal on Mathematical Analysis. - : Society for Industrial & Applied Mathematics (SIAM). - 0036-1410 .- 1095-7111 .- 1095-7154. ; 47:4, s. 2657-2688
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Tidskriftsartikel (refereegranskat)abstract
- We construct spherically symmetric static solutions to the Einstein-Vlasov system with nonvanishing cosmological constant Λ. The results are divided as follows. For small Λ > 0 we show the existence of globally regular solutions which coincide with the Schwarzschild-deSitter solution in the exterior of the matter regions. For Λ < 0 we show via an energy estimate the existence of globally regular solutions which coincide with the Schwarzschild-anti-deSitter solution in the exterior vacuum region. We also construct solutions with a Schwarzschild singularity at the center regardless of the sign of Λ. For all solutions considered, the energy density and the pressure components have bounded support. Finally, we point out a straightforward method for obtaining a large class of global, nonvacuum spacetimes with topologies ℝ × S3 and ℝ × S2 × ℝ which arise from our solutions as a result of using the periodicity of the Schwarzschild-deSitter solution. A subclass of these solutions contains black holes of different masses.
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| 3. |
- Bjersand, Kathrine, et al.
(författare)
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Drug Sensitivity Testing in Cytoreductive Surgery and Intraperitoneal Chemotherapy of Pseudomyxoma Peritonei
- 2015
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Ingår i: Annals of Surgical Oncology. - : Springer Science and Business Media LLC. - 1068-9265 .- 1534-4681. ; 22, s. S810-S816
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Cytoreductive surgery (CRS) and intraperitoneal chemotherapy (IPC) is an established therapy for pseudomyxoma peritonei (PMP). However, the role of IPC is unclear. By ex vivo assessment of PMP tumor cell sensitivity to cytotoxic drugs, we investigated the basis for IPC drug selection and the role of IPC in the management of PMP.METHODS: Tumor cells were prepared by collagenase digestion of tumor tissue from 133 PMP patients planned for CRS and IPC. Tumor cell sensitivity to oxaliplatin, 5FU, mitomycin C, doxorubicin, irinotecan, and cisplatin was assessed in a 72-h cell-viability assay. Drug sensitivity was correlated to progression-free survival (PFS) and overall survival (OS).RESULTS: Samples from 92 patients were analyzed successfully. Drug sensitivity varied considerably between samples. Peritoneal mucinous carcinomatosis (PMCA), compared with PMCA intermediate or disseminated peritoneal adenomucinosis, was slightly more resistant to platinum and 5FU and tumor cells from patients previously treated with chemotherapy were generally less sensitive than those from untreated patients. Multivariate analysis showed patient performance status and completeness of CRS to be prognostic for OS. Among patients with complete CRS (n = 61), PFS tended to be associated with sensitivity to mitomycin C and cisplatin (p ≈ 0.06). At the highest drug concentration tested, the hazard ratio for disease relapse increased stepwise with drug resistance for all drugs.CONCLUSIONS: Ex vivo assessment of drug sensitivity in PMP provides prognostic information. The results suggest a role for IPC as therapeutic adjunct to CRS and for individualization of IPC by pretreatment assessment of drug sensitivity.
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