| 1. |
- Falconer, D., et al.
(författare)
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New Air-interface Technologies and Deployment Concepts
- 2006
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Ingår i: Technologies for the Wireless Future: Wireless World Research Forum (WWRF). - Chichester, UK : John Wiley & Sons. - 0470029056 - 9780470029053 ; , s. 131-226
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 2. |
- Gharanjik, Ahmad, et al.
(författare)
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Precoding design and user selection for multibeam satellite channels
- 2015
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Ingår i: IEEE Workshop on Signal Processing Advances in Wireless Communications, SPAWC. - : IEEE conference proceedings. - 9781479919307 ; , s. 420-424
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Konferensbidrag (refereegranskat)abstract
- Precoding for the downlink of a multibeam satellite system has been recently shown, under ideal conditions, to be promising technique towards employing aggressive frequency reuse gainfully. However, time varying phase uncertainties imposed by the components and the channel, combined with delayed feedback perturbs the channel state information at the transmitter (CSIT). In this paper, we consider a power constrained robust formulation of the downlink precoding problem to counter the phase uncertainties. In particular it considers imposing conditions on the average signal to interference plus noise ratio (SINR), to deal with imperfect CSIT. In addition to the robust formulation, the primacy of user selection is highlighted and a new approach exploiting the satellite system design is proposed. Performance of the derived robust precoder in conjunction with the proposed location based user selection is then evaluated and the gains are tabulated.
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| 3. |
- Gharanjik, Ahmad, et al.
(författare)
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Robust precoding design for multibeam downlink satellite channel with phase uncertainty
- 2015
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Ingår i: ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings. - : IEEE conference proceedings. - 9781467369978 ; , s. 3083-3087
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Konferensbidrag (refereegranskat)abstract
- n this work, we study the design of a precoder on the user downlink of a multibeam satellite channel. The variations in channel due to phase noise introduced by on-board oscillators and the long round trip delay result in outdated channel information at the transmitter. The phase uncertainty is modelled and a robust design framework is formulated based on availability and power constraints. The optimization problem is cast into the convex paradigm after approximations and the benefits of the resulting precoder are highlighted.
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| 4. |
- Höglund, M., et al.
(författare)
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Dose-dependent mobilisation of haematopoietic progenitor cells in healthy volunteers receiving glycosylated rHuG-CSF
- 1996
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Ingår i: Bone Marrow Transplantation. - 0268-3369 .- 1476-5365. ; 18:1, s. 19-27
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Tidskriftsartikel (refereegranskat)abstract
- In an attempt to optimise the dose of G-CSF for mobilisation of PBPC in allogeneic donors, four groups of six healthy male volunteers received lenograstim (glycosylated rHuG-CSF) at a dose of 3, 5, 7.5 or 10 micrograms/kg/day, respectively, for 6 days (days 1-6). All subjects underwent a 10 I leukapheresis. Lenograstim was well tolerated. Maximal mobilisation was observed on days 5 or 6, with a clear dose-response for all progenitor cell types (CD34+, CFU-GM, BFU-E, CFU-mix). The peak numbers of CD34+ cells/microlitre (mean, s.e.m.) were 30 +/- 5, 49 +/- 8, 44 +/- 5 and 122 +/- 30 in the 3, 5, 7.5 and 10 micrograms/kg groups, respectively. A good correlation was observed between the number of CD34+ cells in blood and leukapheresis product (LP), respectively. Increasing the dose of lenograstim did not increase the number of T cells in the LP. A comparison of LP and steady state BM CD34+ cells in paired samples from each individual, showed a higher proportion of primitive immunophenotypes (CDw90+, HLA-DR-, CD45RA-, CD33-) among LP CD34+ cells. We conclude that increased doses of G-CSF improve the mobilisation of PBPC, and that G-CSF favours mobilisation of primitive CD34+ cell subsets. Lenograstim 10 micrograms/kg/day for 6 days should provide a sufficiently effective mobilisation of PBPC in most healthy PBPC donors.
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| 5. |
- Höglund, M., et al.
(författare)
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Mobilization of CD34+ cells by glycosylated and nonglycosylated G-CSF in healthy volunteers : a comparative study
- 1997
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Ingår i: European Journal of Haematology. - : Wiley. - 0902-4441 .- 1600-0609. ; 59:3, s. 177-183
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Tidskriftsartikel (refereegranskat)abstract
- In vitro studies indicate that lenograstim (glycosylated G-CSF) is more potent than filgrastim (nonglycosylated G-CSF) on a weight for weight basis. However, such a difference has not yet been shown in vivo. The primary objective of this trial was to compare the efficacy of equivalent doses (microgram) of lenograstim and filgrastim in mobilizing CD34+ cells. Thirty-two healthy male volunteers, median age 27 yr (19-44 yr), were randomized to receive either lenograstim 10 micrograms/kg followed by filgrastim 10 micrograms/kg or vice versa with a washout period of a minimum 4 wk. Both drugs were administered as s.c. injections once daily for 5 d (d 1-5). CD34+ cells were mobilized with a similar kinetics, peaking at median d 6 (5-6) for both drugs. A significant difference in favour of lenograstim was shown for peak number of CD34+ cells/microliter blood (104 +/- 38 vs. 82 +/- 35, mean +/- 1 SD, p < 0.0001, paired t-test, n = 30) and number of CFU-GM/microliter blood at d 6 (14.6 +/- 8.4 vs. 10.2 +/- 4.6, p < 0.0001), respectively. There was no difference in the d 6 number of CD3+ cells. Both drugs were generally well tolerated and did not differ with respect to number of adverse events. In conclusion, lenograstim 10 micrograms/kg/d mobilizes PBPC more efficiently than the identical dose of filgrastim, indicating a difference in in vivo potency between the two G-CSFs.
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| 6. |
- Jordan, Stanley C., et al.
(författare)
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Imlifidase desensitization in crossmatch-positive, highly-sensitized kidney transplant recipients : Results of an international phase 2 trial (Highdes)
- 2021
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Ingår i: Transplantation. - 0041-1337 .- 1534-6080. ; 105:8, s. 1808-1817
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Highly-HLA sensitized patients have limited access to life-saving kidney transplantation due to a paucity of immunologically suitable donors. Imlifidase is a cysteine protease that cleaves IgG leading to a rapid decrease in antibody level and inhibition of IgG-mediated injury. This study investigates the efficacy and safety of imlifidase in converting a positive crossmatch test to negative, allowing highly sensitized patients to be transplanted with a living or deceased donor kidney.METHODS: This open-label, single arm, phase 2 trial conducted at five transplant centers, evaluated the ability of imlifidase to create a negative crossmatch test within 24 hours. Secondary endpoints included post-imlifidase DSA levels compared to pre-dose levels, renal function, and pharmacokinetic/pharmacodynamic profiles. Safety endpoints included adverse events and immunogenicity profile.RESULTS: 89.5% of the transplanted patients demonstrated conversion of baseline positive crossmatch to negative within 24 hours after imlifidase treatment. DSA most often rebounded 3-14 days post-imlifidase dose, with substantial interpatient variability. Patient survival was 100% with graft survival of 88.9% at 6 months. 38.9% had early biopsy proven antibody mediated rejection with onset 2-19 days post-transplantation. Serum IgG levels began to normalize after ~3-7 days post-transplantation. Anti-drug antibody levels were consistent with previous studies. Seven adverse events in six patients were classified as possibly or probably related to treatment and were mild-moderate in severity.CONCLUSIONS: Imlifidase was well tolerated, converted positive crossmatches to negative, and enabled patients with a median cPRA of 99.83% to undergo kidney transplantation resulting in good kidney function and graft survival at 6 months.
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| 7. |
- Koefoed-Nielsen, P., et al.
(författare)
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Scandiatransplant acceptable mismatch program (STAMP) a bridge to transplanting highly immunized patients
- 2017
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Ingår i: HLA. - : Wiley. - 2059-2302 .- 2059-2310. ; 90:1, s. 17-24
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Tidskriftsartikel (refereegranskat)abstract
- Background: Highly immunized patients are a challenge for organ transplantation programs. One way of increasing the likelihood of transplantation in this group of patients is to expand the possible donations by defining acceptable HLA mismatches. In the Scandiatransplant Acceptable Mismatch Program (STAMP), a decentralized approach has been implemented in 2009. Aims: The program has been improved during the years from utilizing HLA-A, -B, -DR matching only to include typing of all deceased donors for HLA-A, -B, -C, -DRB1 and -DQB1. The calculation of a transplantability score (TS) has been introduced in order to take both HLA and AB0 into consideration resulting in a more realistic picture of the transplantability chance. Materials and Methods: Patients were selected for eligibility and results of immunisation status were prepared in each of the 9 tissue typing laboratories, while access to the program is finally governed by a common steering group of immunologists and clinicians. Results: In the period from March 2009 until February 2015, 96 patients were transplanted within this program. The mean recipient age was 49 years and 57% were females, 30% of the patients were first transplants and of these 93% were females. The majority of the patients had 2-5 HLA-A, -B. -DR mismatches. The allograft survival at 60 months was 79.1%. Applying the TS to the cohort confirmed that patients with a low TS score had longer waiting times. Conclusion: The program has matured during the years and now proves to be a valid approach for transplanting highly immunized patients.
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| 8. |
- Ortqvist, E., et al.
(författare)
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Temporary preservation of beta-cell function by diazoxide treatment in childhood type 1 diabetes
- 2004
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Ingår i: Diabetes Care. - : American Diabetes Association. - 0149-5992 .- 1935-5548. ; 27:9, s. 2191-7
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: We examined the effect of diazoxide, an ATP-sensitive K(+) channel opener and inhibitor of insulin secretion, on beta-cell function and remission in children at clinical onset of type 1 diabetes. RESEARCH DESIGN AND METHODS: A total of 56 subjects (21 girls and 35 boys, age 7-17 years) were randomized to 3 months of active treatment (diazoxide 5-7.5 mg/kg in divided doses) or placebo in addition to multiple daily insulin injections and were followed for 2 years. RESULTS: Diazoxide decreased circulating C-peptide concentrations by approximately 50%. After cessation of the treatment, basal and meal-stimulated C-peptide concentrations increased to a maximum at 6 months, followed by a decline. Meal-stimulated C-peptide concentration was significantly higher at 12 months (0.43 +/- 0.22 vs. 0.31 +/- 0.26 nmol/l, P = 0.018) and tended to fall less from clinical onset to 24 months in the diazoxide- vs. placebo-treated patients (-0.05 +/- 0.24 vs. -0.18 +/- 0.26 nmol/l, P = 0.064). At 24 months, the meal-stimulated C-peptide concentrations were 0.24 +/- 0.20 and 0.20 +/- 0.17 nmol/l, respectively. Side effects of diazoxide were prevalent. CONCLUSIONS: This study demonstrates that partial inhibition of insulin secretion for 3 months at onset of childhood type 1 diabetes suspends the period of remission and temporarily preserves residual insulin production. Further evaluation of the full potential of beta-cell rest will require compounds with less side effects as well as protocols optimized for sustained secretory arrest.
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| 9. |
- Shankar, M. R. Bhavani, et al.
(författare)
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Convergence of the Iterative Water-Filling Algorithm with Sequential Updates in Spectrum Sharing Scenarios
- 2011
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Ingår i: 2011 IEEE INTERNATIONAL CONFERENCE ON ACOUSTICS, SPEECH, AND SIGNAL PROCESSING. - 9781457705397 ; , s. 3216-3219
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Konferensbidrag (refereegranskat)abstract
- Spectrum sharing between two independent, co-existing transmit-receive pairs (TRPs) is formulated as a non-cooperative game with the TRPs as players, their individual link rates as payoffs and power allocation over the utilized spectral bands as the strategy. A Nash Equilibrium (NE) corresponds to the outcome of such a game and TRPs iteratively use the water-filling algorithm according to an agreed order for achieving the NE. Dynamics of this distributed algorithm is studied to determine the conditions for convergence and characterize the resulting NE. A sufficient condition on global convergence is derived and is shown to be tighter than existing ones. Further, a novel characterization of the globally achievable NE based on necessary conditions is presented. Some of these results are also extended to multiple NE scenarios where local convergence is exhibited.
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| 10. |
- von Wrycza, Peter, 1981-, et al.
(författare)
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A Game Theoretic Approach to Multi-User Spectrum Allocation
- 2009
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Ingår i: GLOBECOM 2009 - 2009 IEEE Global Telecommunications Conference. - : IEEE. - 9781424441471 ; , s. 5425963-
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Konferensbidrag (refereegranskat)abstract
- We consider the interaction of several transmit-receive pairs coexisting in the same area and communicating using the same portion of the spectrum. Using a game theoretic framework, each pair is regarded as a player whose payoff function is the individual link rate and power is allocated using the iterative water-filling algorithm. We find properties of the resulting Nash equilibria and derive conditions for when various operating points are achievable. The analysis presented herein extends previous work by characterizing the set of stable solutions for a multi-user system. Also, we show how the game can be modified to obtain better operating points in terms of sum rate compared to the iterative water-filling algorithm. The increase in performance corresponding to one such modification is evaluated and compared to the iterative water-filling algorithm by numerical simulations.
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