| 1. |
- Ail, Ujwala, et al.
(författare)
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Room temperature synthesis of transition metal silicide-conducting polymer micro-composites for thermoelectric applications
- 2017
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Ingår i: Synthetic metals. - : Elsevier BV. - 0379-6779 .- 1879-3290. ; 225, s. 55-63
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Tidskriftsartikel (refereegranskat)abstract
- Organic polymer thermoelectrics (TE) as well as transition metal (TM) silicides are two thermoelectric class of materials of interest because they are composed of atomic elements of high abundance; which is a prerequisite for mass implementation of thermoelectric (TE) solutions for solar and waste heat recovery. But both materials have drawbacks when it comes to finding low-cost manufacturing. The metal silicide needs high temperature (>1000 °C) for creating TE legs in a device from solid powder, but it is easy to achieve long TE legs in this case. On the contrary, organic TEs are synthesized at low temperature from solution. However, it is difficult to form long legs or thick films because of their low solubility. In this work, we propose a novel method for the room temperature synthesis of TE composite containing the microparticles of chromium disilicide; CrSi2 (inorganic filler) in an organic matrix of nanofibrillated cellulose- poly(3,4-ethyelenedioxythiophene)-polystyrene sulfonate (NFC-PEDOT:PSS). With this method, it is easy to create long TE legs in a room temperature process. The originality of the approach is the use of conducting polymer aerogel microparticles mixed with CrSi2 microparticles to obtain a composite solid at room temperature under pressure. We foresee that the method can be scaled up to fabricate and pattern TE modules. The composite has an electrical conductivity (σ) of 5.4 ± 0.5 S/cm and the Seebeck coefficient (α) of 88 ± 9 ΌV/K, power factor (α2σ) of 4 ± 1 ΌWm−1K−2 at room temperature. At a temperature difference of 32 °C, the output power/unit area drawn across the load, with the resistance same as the internal resistance of the device is 0.6 ± 0.1 ΌW/cm2.
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| 2. |
- Andersson, Henrik, et al.
(författare)
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Using optimization to provide decision support for strategic emergency medical service planning - Three case studies
- 2020
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Ingår i: International Journal of Medical Informatics. - : ELSEVIER IRELAND LTD. - 1386-5056 .- 1872-8243. ; 133
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Tidskriftsartikel (refereegranskat)abstract
- To achieve high performing emergency medical services (EMS), planning is of vital importance. EMS planners face several challenges when managing ambulance stations and the fleet of ambulances. In this paper, three strategic cases for EMS planners are presented together with potential solutions. In the first case, the effects of closing down a local emergency room (ER) are analyzed together with how adding an ambulance station and an ambulance to the area affected by the closing of the ER can be used to mitigate the negative consequences from the closing. The second case investigates a change in the organization of EMS. Currently, many non-urgent transport assignments are performed by ambulances which make them unavailable for more urgent calls. The potential for a more effective utilization of the ambulances is explored through transferring these assignments to designated transport vehicles. The third case is more technical and challenges the common practice regarding how time dependent demand is handled. Looking at the busiest hour or the average daily demand, is compared with taking time varying demand into account. The cases and solutions are studied using a recently developed strategic ambulance station location and ambulance allocation model for the Maximum Expected Performance Location Problem with Heterogeneous Regions (MEPLP-HR). The model has been extended to also include multiple time periods. This article demonstrates an innovative use of the model and how it can be applied to find and evaluate solutions to real cases within the field of strategic planning of EMS. The model is found to be a useful decision support tool when analyzing the cases and the expected performance of potential solutions.
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| 3. |
- Barth, Maren S., et al.
(författare)
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Emergency exit layout planning using optimization and agent-based simulation
- 2024
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Ingår i: Computational Management Science. - : SPRINGER HEIDELBERG. - 1619-697X .- 1619-6988. ; 21:1
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Tidskriftsartikel (refereegranskat)abstract
- Evacuation preparedness includes ensuring proper infrastructure, resources and planning for moving people from a dangerous area to safety. This is especially important and challenging during mass gatherings, such as large concerts. In this paper, we present the Emergency Exit Layout Problem (EELP) which is the problem of locating a given number of emergency exits and deciding their width such that the time it takes to evacuate the crowd from an arena is minimized. The EELP takes into account the geography of the arena and its surroundings, as well as the number of pedestrians in the crowd and the distribution of these within the arena. The EELP is formulated as a two-stage stochastic mixed integer linear program to handle the uncertainty related to the location of the possible incidents and the distribution of the pedestrians. Two cases are studied, a large concert planned at the Leangen trotting track in Trondheim and a smaller indoor arena. For each case, the EELP is solved for different scenarios, and the suggested layouts are evaluated using an agent-based simulation model. In particular, the potential of incorporating detailed assessment regarding the location and probability of specific incidents and the distribution of pedestrians are investigated. The computational study shows that making a more detailed risk assessment has little effect on the large concert, but a significant impact on the location of the emergency exits for the smaller indoor case. The results also indicate that it is more important to consider the location and probability of specific incidents rather than the pedestrian distribution.
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| 4. |
- Böhlenius, Henrik, et al.
(författare)
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Biomass production and fuel characteristics from long rotation poplar plantations
- 2023
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Ingår i: Biomass and Bioenergy. - : Elsevier Ltd. - 0961-9534 .- 1873-2909. ; 178
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Tidskriftsartikel (refereegranskat)abstract
- One of the key elements in this transition is the securing of a large supply of sustainable biomass. In this study, the feedstock potential of long rotation poplar plantations (12–30 years with diameter of 15 of 30 cm) was determined and the properties of poplar biomass fuel were analyzed with the aim of using thermochemical conversion methods to produce biofuel. Our results demonstrate that Sweden has great potential for producing biofuels from long rotation poplar plantations, with a total of 1.8 million hectares (ha) consisting of arable (0.5 million ha) and forested arable land (1.3 million ha). Based on available land and biomass production potential, our results indicate that 10 million Mg DW could be produced annually. Regions in mid/southern Sweden have the largest potential (larger areas and higher biomass production. Our results further suggest that poplar biomass from these plantations has fuel characteristics similar to forest fuels from other conifer tree species, making the biomass suitable as feedstock for biofuel production based on thermochemical conversion methods. If 25% of the available land were used, 7.6 TWh methanol biofuels could be produced annually from 16 biofuel plants, using 160,000 Mg DW yr−1, primarily located in the southern part of Sweden. Two counties (Skåne and Västra Götaland) would be able to support their biofuel plants using poplar plantations as feedstock. Stable biofuel production in the other counties would depend on collaborating with neighboring counties.
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| 5. |
- Dahlblom, Victor, et al.
(författare)
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Malmö Breast ImaginG database: objectives and development
- 2023
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Ingår i: Journal of Medical Imaging. - 2329-4302. ; 10:6
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Tidskriftsartikel (refereegranskat)abstract
- PurposeWe describe the design and implementation of the Malmö Breast ImaginG (M-BIG) database, which will support research projects investigating various aspects of current and future breast cancer screening programs. Specifically, M-BIG will provide clinical data to: 1. investigate the effect of breast cancer screening on breast cancer prognosis and mortality; 2. develop and validate the use of artificial intelligence and machine learning in breast image interpretation; and 3. develop and validate image-based radiological breast cancer risk profiles.ApproachThe M-BIG database is intended to include a wide range of digital mammography (DM) and digital breast tomosynthesis (DBT) examinations performed on women at the Mammography Clinic in Malmö, Sweden, from the introduction of DM in 2004 through 2020. Subjects may be included multiple times and for diverse reasons. The image data are linked to extensive clinical, diagnostic, and demographic data from several registries.ResultsTo date, the database contains a total of 451,054 examinations from 104,791 women. During the inclusion period, 95,258 unique women were screened. A total of 19,968 examinations were performed using DBT, whereas the rest used DM.ConclusionsWe describe the design and implementation of the M-BIG database as a representative and accessible medical image database linked to various types of medical data. Work is ongoing to add features and curate the existing data.
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| 6. |
- Ekeblad, Sara, et al.
(författare)
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Temozolomide as monotherapy is effective in treatment of advanced malignant neuroendocrine tumors
- 2007
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Ingår i: Clinical Cancer Research. - 1078-0432 .- 1557-3265. ; 13:10, s. 2986-2991
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: A retrospective analysis of the toxicity and efficacy of temozolomide in advanced neuroendocrine tumors. Experimental Design: Thirty-six patients with advanced stages of neuroendocrine tumor (1 gastric, 7 thymic and 13 bronchial carcinoids, 12 pancreatic endocrine tumors, 1 paraganglioma, 1 neuroendocrine foregut, and 1 neuroendocrine cecal cancer) were treated with temozolomide (200 mg/m2) for 5 days every 4 weeks. Patients had previously received a mean of 2.4 antitumoral medical regimens. Tumor response was evaluated radiologically according to the Response Evaluation Criteria in Solid Tumors every 3 months on an intent-to-treat basis. The circulating tumor marker plasma chromogranin A was also assessed. The expression of 06-methylguanine DNA methyltransferase, an enzyme implicated in chemotherapy resistance, was studied by immunohistochemistry (n = 23) and compared with response to temozolomide. Results: Median overall time to progression was 7 months (95% confidence interval, 3-10). Radiologic response was seen in 14% of patients and stable disease in 53%. Side effects were mainly hematologic; 14% experienced grade 3 or 4 thrombocytopenia (National Cancer Institute toxicity criteria). Ten patients had tumors with 06-methylguanine DNA methyltransferase immunoreactivity in <10% of nuclei, whereas four patients showed radiologic responses. Conclusions: Temozolomide as monotherapy had acceptable toxicity and antitumoral effects in a small series of patients with advanced malignant neuroendocrine tumors and four of these showed radiologic responses.
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| 7. |
- Falhammar, Henrik, et al.
(författare)
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Fertility, Sexuality and Testicular Adrenal Rest Tumors in Adult Males with Congenital Adrenal Hyperplasia.
- 2012
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Ingår i: European journal of endocrinology. - 1479-683X. ; 166, s. 441-449
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Fertility in males with congenital adrenal hyperplasia (CAH) is reported from normal to severely impaired. We therefore investigated fertility/fecundity, social/sexual situation, and pituitary- gonadal function in CAH males.Subjects and methods: The patient cohort comprised 30 males with 21-hydroxylase deficiency, 19-67 yr. Their fertility was compared with age-matched national population data. For the evaluation of social/sexual factors and hormone status, age-matched controls were recruited (n=32). Subgroups of different ages (<30 years and older) and CYP21A2 genotypes: null (severe salt wasting), I2splice (milder salt wasting), and I172N (simple virilizing) were also studied. Patients underwent testicular ultrasound examination (n=21), and semen analysis (n=14).Results: Fertility was impaired in CAH males compared to national data (0.9±1.3 vs. 1.8±0.5 children/father, P<0.001). There were no major differences in social and sexual factors between patients and controls apart from more fecundity problems, particularly in the I172N group. The patients had lower testosterone/estradiol ratio and inhibin B, and higher FSH. The semen samples were pathological in 43% (6/14) of patients and sperm concentration correlated with inhibin B and FSH. Testicular adrenal rest tumours (TARTs) were found in 86% (18/21). Functional testicular volume correlated positively with the testosterone/estradiol ratio, sperm concentration and inhibin B. Patients with pathological semen had increased fat mass and indications of increased cardiometabolic risk.Conclusions: Fertility/fecundity was impaired in CAH males. The frequent occurrence of TARTs resulting in testicular insufficiency appears to be the major cause, but other factors such as elevated fat mass may contribute to a low semen quality.
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| 8. |
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| 9. |
- Frigstad, Lasse, et al.
(författare)
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Joint planning of drones and volunteers in emergency response to out-of-hospital cardiac arrest
- 2023
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Ingår i: Computers & industrial engineering. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0360-8352 .- 1879-0550. ; 185
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Tidskriftsartikel (refereegranskat)abstract
- Various initiatives are in place worldwide to reduce the time from the occurrence of an out-of-hospital cardiac arrest to the start of cardiopulmonary resuscitation (CPR) and defibrillation using an Automated External Defibrillator (AED). In addition to optimizing the management of emergency medical services and other professional emergency response resources, these include utilizing close-by volunteers using mobile phone dispatching, and delivering AEDs using Unmanned Aerial Vehicles (UAVs), commonly known as drones. The latter two examples have previously been studied separately, and it has been proved that the time to administer CPR and AED delivery can be reduced. In this paper, the potential of joint planning and dispatching of volunteers and AED delivering drones is investigated. Optimization models are used to determine good locations for drones. These are then evaluated, together with new, adapted dispatch strategies for the volunteers, using a simulation model. Results of a case study, with data for the county of Vastra Gotaland in Sweden, show that drones can indeed help reduce the time to defibrillation, and, by adaptive dispatching, the time to CPR can be reduced as well. Thus, it is shown that by joint planning of drones and volunteers, it may be possible to improve the survival probability from out-of-hospital cardiac arrest.
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| 10. |
- Granberg, Dan, et al.
(författare)
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Liver embolization with trisacryl gelatin microspheres (embosphere) in patients with neuroendocrine tumors
- 2007
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Ingår i: Acta Radiologica. - : SAGE Publications. - 0284-1851 .- 1600-0455. ; 48:2, s. 180-185
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To report our experience of liver embolization with trisacryl gelatin microspheres (Embospheretrade mark) in patients with metastatic neuroendocrine tumors. MATERIAL AND METHODS: Fifteen patients underwent selective embolization of the right or left hepatic artery with Embosphere. One lobe was embolized in seven patients and both lobes, on separate occasions, in eight patients. Seven patients had midgut carcinoids, two had lung carcinoids, one suffered from a thymic carcinoid, and five had endocrine pancreatic tumors. Eight patients suffered from endocrine symptoms, seven of whom had carcinoid syndrome and one WDHA (watery diarrhea, hypokalemia, achlorhydria) syndrome. RESULTS: Partial radiological response was seen after eight embolizations (in six different patients), stable disease was observed after 13 embolizations (after three of these, necroses occurred), while radiological progression was noted after only two embolizations. Only two patients experienced a biochemical response. Clinical improvement of carcinoid syndrome was observed after five embolizations. There were no major complications. Fever >38 degrees C was seen after all but four embolizations, and urinary tract infections were diagnosed after eight embolizations. CONCLUSION: Selective hepatic artery embolization with Embosphere particles is a safe treatment for patients with metastatic neuroendocrine tumors and may lead to partial radiological response as well as symptomatic improvement of disabling endocrine symptoms.
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