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| 3. |
- Bengtsson, Erik L, et al.
(författare)
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A Case Study on the Influence of Multiple Users on the Effective Channel in a Massive MIMO System
- 2019
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Ingår i: IEEE Wireless Communications Letters. - 2162-2337. ; , s. 1-6
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Tidskriftsartikel (refereegranskat)abstract
- We investigate the importance of weak clusters when modeling a wireless massive MIMO channel. We do this by studying the influence of densely spaced terminals and the number of base-station antennas for a zero-forcing precoded massive MIMO system. In particular, we focus on the influence on the correlation and imbalance between the signals at the terminal antennas, the effective channel-gain, the eigenvalue distributions and the number of clusters.The study is based on measured radio-channels from terminal prototypes with integrated antennas connected to a massive MIMO testbed.We further evaluate the advantage of using block-diagonalized zero-forcing compared to conventional zero-forcing in a massive MIMO system. Unexpectedly, terminals with low antenna envelope correlation coefficient may benefit significantly from block-diagonal zero-forcing in a massive MIMO system.The main conclusion is that weaker clusters are important when modeling multi-user scenarios.
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| 4. |
- Bengtsson, Erik L., et al.
(författare)
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A Simulation Framework for Multiple-Antenna Terminals in 5G Massive MIMO Systems
- 2017
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Ingår i: IEEE Access. - 2169-3536. ; 5, s. 26819-26831
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Tidskriftsartikel (refereegranskat)abstract
- The recent interest in massive MIMO has spurred intensive work on massive MIMO channel modeling in contemporary literature. However, current models fail to take the characteristics of terminal antennas into account. There is no massive MIMO channel model available that can be used for evaluation of the influence of different antenna characteristics at the terminal side. In this paper, we provide a simulation framework that fills this gap. We evaluate the framework with antennas integrated into Sony Xperia handsets operating at 3.7 GHz as this spectrum is identified for the 5G new radio standard by 3GPP. The simulation results are compared with measured terminal performance when communicating with the Lund University’s massive MIMO testbed under the same loading conditions. Expressions are derived for comparison of the gain obtained from different diversity schemes computed from measured far-field antenna patterns. We conclude that the simulation framework yields results close to the measured ones and that the framework can be used for antenna evaluation for terminals in a practical precoded massive MIMO system.
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| 5. |
- Bengtsson, Erik L., et al.
(författare)
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Analysis of Transmission Schemes for Dual-Antenna Terminals in Massive MIMO Systems
- 2018
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Ingår i: 2018 25th International Conference on Telecommunications, ICT 2018. - 9781538623213 ; , s. 76-82
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Konferensbidrag (refereegranskat)abstract
- The overall system performance of massive MIMO is improved by equipping user terminals with multiple antennas. In this paper, we investigate transceiver designs for the case of a single downlink stream and in particular, we study the uplink pilot design. Moreover, we study the consequences of channel estimation errors at the base-station, and to what extent a dual-antenna terminal can get access to relevant channel statistics for optimization of the pilot signal. Gain expressions for comparison of different designs are derived. We verify the analytic results based on antennas integrated into Sony-Xperia handsets measured with the Lund University massive MIMO testbed. The measurements are performed at frequencies <6GHz since this part of the spectrum is a candidate for NR standard according to 3GPP.
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| 6. |
- Bengtsson, Erik L, et al.
(författare)
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Transmission schemes for Multiple Antenna Terminals in Real Massive MIMO systems
- 2016
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Ingår i: 2016 IEEE Global Communications Conference (GLOBECOM). - 9781509013289 - 9781509013296
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Konferensbidrag (refereegranskat)abstract
- In massive MIMO performance evaluations it is often assumed that the terminal has a single antenna. The combination of multiple antennas in a terminal and massive MIMO precoding at the base station side can further improve overall system performance. We present measurement results for multi antenna terminals operating in different transmission schemes and how they perform under varying loading conditions. Gain expressions are derived that enable easy comparison between the transmission schemes. The evaluation is performed on realistic antennas integrated into Sony Xperia handsets tuned to 3.7~GHz and operated together with the Lund University massive MIMO (LuMaMi) test bed. It is concluded that the approach used in today's mobile systems, where up link and down link are addressed independently, will not provide the best performance. The performance can be improved by the selection of transmission schemes optimized for massive MIMO.
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| 8. |
- Bratt, Ola, et al.
(författare)
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Satsa på MRT för diagnostik av prostatacancer.
- 2015
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Ingår i: Läkartidningen. - : Läkartidningen Förlag. - 1652-7518 .- 0023-7205. ; 112:Apr 20, s. DFZ3-
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 11. |
- Davidsson, Sabina, 1972-, et al.
(författare)
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Frequency and typing of Propionibacterium acnes in prostate tissue obtained from men with and without prostate cancer
- 2016
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Ingår i: Infectious Agents and Cancer. - London, United Kingdom : BioMed Central (BMC). - 1750-9378. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Background: Prostate cancer is the most common cancer among men in Western countries but the exact pathogenic mechanism of the disease is still largely unknown. An infectious etiology and infection-induced inflammation has been suggested to play a role in prostate carcinogenesis and Propionibacterium acnes has been reported as the most prevalent microorganism in prostatic tissue. We investigated the frequency and types of P. acnes isolated from prostate tissue samples from men with prostate cancer and from control patients without the disease.Methods: We included 100 cases and 50 controls in this study. Cases were men diagnosed with prostate cancer undergoing radical prostatectomy and controls were men undergoing surgery for bladder cancer without any histological findings of prostate cancer. Six biopsies taken from each patient's prostate gland at the time of surgery were used for cultivation and further characterization of P. acnes.Results: The results revealed that P. acnes was more common in men with prostate carcinoma than in controls, with the bacteria cultured in 60 % of the cases vs. 26 % of the controls (p = 0.001). In multivariable analyses, men with P. acnes had a 4-fold increase in odds of a prostate cancer diagnosis after adjustment for age, calendar year of surgery and smoking status (OR: 4.46; 95 % CI: 1.93-11.26). To further support the biologic plausibility for a P. acnes infection as a contributing factor in prostate cancer development, we subsequently conducted cell-based experiments. P. acnes- isolates were co-cultured with the prostate cell line PNT1A. An increased cell proliferation and cytokine/chemokine secretion in infected cells was observed.Conclusion: The present study provides further evidence for a role of P. acnes in prostate cancer development.
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| 12. |
- Edvardsson Björnberg, Karin, et al.
(författare)
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Climate and environmental science denial : A review of the scientific literature published in 1990-2015
- 2017
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Ingår i: Journal of Cleaner Production. - : Elsevier. - 0959-6526 .- 1879-1786. ; 167, s. 229-241
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Forskningsöversikt (refereegranskat)abstract
- Denial of scientific findings is neither a new nor an unexplored phenomenon. In the area of environmental science and policy though, the research on denial has not been systematically summarized and analyzed. This article reviews 161 scientific articles on environmental and climate science denial published in peer reviewed international journals in the last 25 years and aims to both identify research gaps and enable learning on the phenomenon. Such knowledge is needed for the increasingly important task to provide effective response to science denial, in order to put an end to its influence on environmental policy making. The review, which is based on articles found in the databases Web of Science, Scopus and Philosopher's Index, shows that denial by far is most studied in relation to climate change, with a focus on Anglo-American countries, where this form of denial is most common. Other environmental issues and other geographical areas have received much less scientific attention. While the actors behind climate science denial, their various motives and the characteristics of their operations have been thoroughly described, more comparative research between issues and countries is needed in order to draw reliable conclusions about the factors explaining the peculiarities of denial. This may in turn lay the ground for developing and actually testing the effectiveness and efficiency of strategies to counter environmental science denial. Irrespective of the ambitions of environmental goals, science-based policies are always preferable. The scientific community therefore needs to increase its efforts to dismantle false claims and to disclose the schemes of denialists.
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| 15. |
- Glimelius, Bengt, et al.
(författare)
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U-CAN : a prospective longitudinal collection of biomaterials and clinical information from adult cancer patients in Sweden.
- 2018
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Ingår i: Acta Oncologica. - : Taylor & Francis. - 0284-186X .- 1651-226X. ; 57:2, s. 187-194
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Tidskriftsartikel (refereegranskat)abstract
- Background: Progress in cancer biomarker discovery is dependent on access to high-quality biological materials and high-resolution clinical data from the same cases. To overcome current limitations, a systematic prospective longitudinal sampling of multidisciplinary clinical data, blood and tissue from cancer patients was therefore initiated in 2010 by Uppsala and Umeå Universities and involving their corresponding University Hospitals, which are referral centers for one third of the Swedish population.Material and Methods: Patients with cancer of selected types who are treated at one of the participating hospitals are eligible for inclusion. The healthcare-integrated sampling scheme encompasses clinical data, questionnaires, blood, fresh frozen and formalin-fixed paraffin-embedded tissue specimens, diagnostic slides and radiology bioimaging data.Results: In this ongoing effort, 12,265 patients with brain tumors, breast cancers, colorectal cancers, gynecological cancers, hematological malignancies, lung cancers, neuroendocrine tumors or prostate cancers have been included until the end of 2016. From the 6914 patients included during the first five years, 98% were sampled for blood at diagnosis, 83% had paraffin-embedded and 58% had fresh frozen tissues collected. For Uppsala County, 55% of all cancer patients were included in the cohort.Conclusions: Close collaboration between participating hospitals and universities enabled prospective, longitudinal biobanking of blood and tissues and collection of multidisciplinary clinical data from cancer patients in the U-CAN cohort. Here, we summarize the first five years of operations, present U-CAN as a highly valuable cohort that will contribute to enhanced cancer research and describe the procedures to access samples and data.
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| 16. |
- Hayden, Jane M., et al.
(författare)
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Post-operative pain relief using local infiltration analgesia during open abdominal hysterectomy: a randomized, double-blind study
- 2017
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Ingår i: Acta Anaesthesiologica Scandinavica. - : Wiley. - 0001-5172 .- 1399-6576. ; 61:5, s. 539-548
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Tidskriftsartikel (refereegranskat)abstract
- © 2017 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd Background: Post-operative pain is common and often severe after open abdominal hysterectomy, and analgesic consumption high. This study assessed the efficacy of local infiltration analgesia (LIA) injected systematically into different tissues during surgery compared with saline on post-operative pain and analgesia. Methods: Fifty-nine patients were randomized to Group LIA (n=29) consisting of 156ml of a mixture of 0.2% ropivacaine + 30mg ketorolac + 0.5mg (5 ml) adrenaline, where the drugs were injected systematically in the operating site, around the proximal vagina, the ligaments, in the fascia and subcutaneously, or to saline and intravenous ketorolac, Group C (Control, n=28), in a double-blind study. Post-operative pain, analgesic consumption, side-effects, and home discharge were analysed. Results: Median dose of rescue morphine given 0–24h after surgery was significantly lower in group LIA (18mg, IQR 5–25mg) compared with group C (27mg, IQR 15–43mg, P=0.028). Median time to first analgesic injection was significantly longer in group LIA (40min, IQR 20–60min) compared with group C (20min, IQR 12–30min, P=0.009). NRS score was lower in the group LIA compared with group C in the direct post-operative period (0–2h). No differences were found in post-operative side-effects or home discharge between the groups. Discussion: Systematically injected local infiltration analgesia for pain management was superior to saline in the primary endpoint, resulting in significantly lower rescue morphine requirements during 0–24h, longer time to first analgesic request and lower early post-operative pain intensity.
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| 17. |
- Karlsson, Mikael, et al.
(författare)
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Farligt när vetenskapen förnekas
- 2017
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Ingår i: Svenska dagbladet. - 1101-2412. ; :6 september
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Tidskriftsartikel (populärvet., debatt m.m.)
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| 18. |
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| 19. |
- Karlsson, Ove
(författare)
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Experience of Point-of-Care Devices in Obstetrical Care
- 2017
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Ingår i: Seminars in Thrombosis and Hemostasis. - 0094-6176 .- 1098-9064. ; 43:4, s. 397-406
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Forskningsöversikt (refereegranskat)abstract
- Copyright © 2017 by Thieme Medical Publishers, Inc. During pregnancy and puerperium, there are pronounced hemostatic changes characterized by increased coagulability and decreased fibrinolysis. In addition, hemostasis can change dramatically during obstetric complications. Several reports have described substandard management of hemostatic defects in this setting and state the need for guidelines and better care. Point-of-care devices can assess hemostatic status and are especially suitable in perioperative settings. Using point-of-care devices, no time is required for transportation, allowing faster availability of results and providing potential for better care of the patient. This article will demonstrate the use of a viscoelastic method in six different patients; five with impaired hemostasis, and where the use of viscoelastic method contributes or should have contributed to better care. The cases represent patients with normal delivery; postpartum hemorrhage (PPH); PPH with low fibrinogen; placental abruption; preeclampsia with hemolysis, elevated liver enzymes, low platelet count syndrome; and finally, one patient with sepsis. This article also shows the need for good practices and good supervision to implement the devices in patient care.
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| 20. |
- Karlsson, Ove, et al.
(författare)
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Fibrinogen plasma concentration before delivery is not associated with postpartum haemorrhage: a prospective observational study.
- 2015
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Ingår i: British journal of anaesthesia. - : Elsevier BV. - 1471-6771 .- 0007-0912. ; 115:1, s. 99-104
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Tidskriftsartikel (refereegranskat)abstract
- Low plasma fibrinogen concentration has been linked to postpartum haemorrhage. The primary aim of this study was to assess whether fibrinogen concentration at admission before labour is associated with severe postpartum haemorrhage. Secondary aims were to describe fibrinogen concentration before and after labour and to identify predictors for severe postpartum haemorrhage.
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| 21. |
- Lekic, Zeljka, et al.
(författare)
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Striking decrease in blood loss with a urologist-assisted standardized multidisciplinary approach in the management of abnormally invasive placenta
- 2017
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Ingår i: Scandinavian Journal of Urology. - 2168-1805 .- 2168-1813. ; 51:6, s. 491-495
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The aim of this study was to investigate the outcome of a standardized multidisciplinary approach using a modified surgical technique in the management of abnormally invasive placenta (AIP), with special reference to blood loss and the need for transfusion. Materials and methods: Data were collected retrospectively in women managed with a recently adopted multidisciplinary strategy using a modified surgical approach, involving a urologist (study group: 10 patients). Women managed before the introduction of this standardized management served as a control group (nine patients). Comparisons were made between the study group and the control group. The main outcome measures were blood loss and the need for transfusion in the two groups. Results: Standardized multidisciplinary management, involving a modified surgical technique performed by a urologist, decreased blood loss in the study group compared with the control group [median 1400 ml (range 400–3000 ml) vs median 8000 ml (2300–40000 ml); p <.001]. It also decreased postoperative complications and the need for transfusion of blood products. Conclusions: Standardized multidisciplinary management of patients with AIP, using a modified surgical technique, reduces the risks of massive obstetric hemorrhage, the need for massive transfusion and the risk of postoperative complications. Involving an experienced urologist appears to be of paramount importance in the management of AIP.
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| 22. |
- Palsdottir, Anna Maria, et al.
(författare)
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ALM-MODELLEN : En 5-stegs modell för företagsutveckling av Attraktiva Landsbygdsplatser baserade på Miljökvalitéer
- 2015
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Ingår i: LTV-fakultetens faktablad.
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Annan publikation (populärvet., debatt m.m.)abstract
- Den svenska landsbygden är rik på möjligheter inom trädgårdsnäringen, men företagandet behöver professionaliseras för att outnyttjade landskaps- och trädgårdskvaliteter ska bli synliga och utvecklingsbara. Inom projektet Tre Modellträdgårdar har SLU i samarbete med tre landsbygdsföretag testat och utvärderat olika modeller från analys- till implementeringsstadiet. Resultaten visar att det med relativt enkla medel går att systematiskt analysera miljökvaliteter och utifrån strikt företagsekonomiska utgångspunkter, i dialog mellan universitet, myndigheter och företag, finna kreativa och företagsekonomiskt hållbara lösningar ur ett trädgårds- och landskapsperspektiv. Ett konkret resultat är introduktionen av ett årligt återkommande konvent inom området. Här presenteras en ny modell för att främja företagsutveckling av Attraktiva Landsbygdsplatser baserade på Miljökvalitéer (ALM). ALM-modellen ska ge företagaren möjlighet att utveckla aktiviteter, som i sin tur kan öka attraktionskraften på ett markant, varaktigt och inkomstbringande sätt.
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