| 1. |
- Anthony, Niklas
(författare)
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Laser Interaction with Minerals Common on Asteroids
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Asteroids are worth studying for three reasons: planetary protection, industrial applications, and scientific knowledge. It is critical we develop technologies capable of diverting objects on collision courses with our planet. We can use the same technology to move or process asteroids and comets for materials to build structures or refuel in Low-Earth Orbit. Asteroids are also windows into the past; they were formed in the early Solar System, and could potentially have been the source of water and/or life on Earth. There are unique challenges to manipulating an asteroid or asteroid materials, which means that much of what we know about material processing needs to be revamped to fit the situation. One of the motivating drives of this research was that a laser would be an excellent tool to perform many tasks at an asteroid.One process of interest is laser drilling. The surface composition of asteroids is altered by aeons of space weathering; by studying the subsurface composition we can ascertain just how much it is altered and possibly by which processes. It is possible that hydrated minerals or ices exist below the surface as well, which are of great economic interest in asteroid mining. One of the greatest challenges to get under the surface of an asteroid is the low gravity: any forces or torques generated by a sampling mechanism may tip the spacecraft or launch it into deep space. A laser does not generate any significant forces, and can even be used without having to land; lasers do use a lot of electric power so the laser parameters need to be optimized to minimize the size and power requirements of the spacecraft. We found that nearly 1-cm deep holes can be made with as little as 18~J of energy using a 300-W laser.Laser ablation has been studied as a mechanism to redirect asteroids, but it is not particularly energy efficient at material removal. If the idea is to create a momentum exchange by removing surface material beyond an object's gravitational pull, then there could perhaps be more energy efficient mechanisms. One mechanism we investigated was spallation, where the shock wave of a laser pulse breaks off a relatively large chunk of material without having to melt and vaporize it. We found that spallation may be many times more energy efficient than ablation.Laser welding of metals has been of industrial interest for decades, though the welding of two different materials is still a challenge. We sought to develop a laser-based wire-attachment mechanism that can be used to anchor spacecraft to the surface of a small body or to maneuver boulders or small asteroids. When attempting to follow a traditional welding process, it was found that the two melt pools would not mix, and if it did, it was very weak. Instead, we used the laser to drill a hole and melt a wire while inserting it into the hole. This produced a solid anchor with a hold strength of up to 120~N.
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| 2. |
- Barabash, Stas, et al.
(författare)
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Towards low-cost Swedish planetary missions
- 2004
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- As a continuation of the Swedish tradition of designing small and high-quality spacecrafts such as Freja, Astrid, Munin, and SMART-1, Swedish scientists and engineers have proposed aggressive but feasible missions as the next national-level target: (1) an interplanetary plasma module (or subsatellite) Saga, and (2) a technology mission Prisma. The Saga micro-satellite contains a separation mechanism, technologically-challenging communication package, and plasma payload with an estimated total mass of 37kg to make the mission possible with a piggy-back launch or by attaching to another planetary mission. The Prisma mission consists of a semi-coordinated dual micro- and nano-satellites flying together in Earth orbit with state-of-art instruments to test. Both projects aim to develop and test new key spacecraft technologies.
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| 3. |
- Becanovic, Vlatko, et al.
(författare)
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HUGIN: a small satellite trying to be intelligent
- 1999
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Ingår i: Proc. SPIE. ; 3728, s. 98-
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Konferensbidrag (refereegranskat)abstract
- Micro and nano-satellites are important tools to explore and test new ideas and various new devices for space missions without spending extreme amounts of money. The actual launch cost per kilogram payload on a micro or nano-satellite can be as high or even higher than ordinary satellites but the turn around time and quick responses are extremely important. The HUGIN project is a nano-satellite (less than 10 kg) explicitly designed to test magnetic coils and adaptive artificial neural network (ANN) algorithms for attitude control purposes. A small PC video camera is also included and if the control function is successful then also tests of adaptive image processing using other ANN and biologically inspired methods will be performed.
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| 4. |
- Ekman, Inger, 1952, et al.
(författare)
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The person-centred approach to an ageing society
- 2013
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Ingår i: European Journal for Person Centered Healthcare. - : University of Buckingham Press. - 2052-5656 .- 2052-5648. ; 1:1, s. 132-137
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Tidskriftsartikel (refereegranskat)abstract
- Modern care is often based on investigations such as laboratory markers and imaging - for example, x-ray or ultrasound. The results contribute to a diagnosis and, if judged necessary, treatment is initiated. This diseased-oriented approach is the prevailing mode of management in modern medicine. In contrast, person-centered care (PCC) takes the point of departure from each person´s subjective experience of illness and its impact on daily life. A patient is considered as a person with emotions and feelings. PCC is considered present within clinical care according to a definition articulated by the Centre for Person Centred Care at the University of Gothenburg (GPCC) when three core components are present: elicitation of a detailed patient narrative; formulated partnership between caregiver and patient and documentation of the partnership in the patient record. Accordingly, when there is an illness requiring care and the person is attended using these components, PCC is being applied. In most situations today, PCC is not applied as the narrative is not fully elicited or the partnership and/or the documentation are not included. It is proposed that the challenge to Society arising from changing demographics can be addressed by implementing PCC and creating an alternative to existing healthcare. The importance and benefits of such an approach on a wider scale is not yet clear as research has been limited to date. Studies in selected patient populations (heart failure and hip fractures), however, have shown promising results. As the population ages, there will be a dramatic increase in healthcare consumption. Even with technological developments, there will be a need for tremendous resources to be dedicated to care. A new organization and attitude from healthcare policymakers and providers above and beyond the present model appears required in order to respond to this demand. As part of such change, person-centred care, with the interaction between healthcare providers and the person of the patient, can facilitate, compensate and develop more effective healthcare services for the future.
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| 5. |
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| 6. |
- Green, Henrik, et al.
(författare)
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Pegylated liposomal doxorubicin as first-line monotherapy in elderly women with locally advanced or metastatic breast cancer : Novel treatment predictive factors identified
- 2011
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Ingår i: Cancer Letters. - : Elsevier BV. - 0304-3835 .- 1872-7980. ; 313:2, s. 145-153
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Tidskriftsartikel (refereegranskat)abstract
- We investigated the efficacy and safety of single-agent pegylated liposomal doxorubicin (PLD) as first-line treatment for elderly women with advanced breast cancer and evaluated predictive markers for response and toxicity. Twenty-five women >= 65 years received 40 mg/m(2) PLD every 28 days. Time to treatment failure (TTF), response rate, time to progression (TTP) and overall survival (OS) was calculated. The ABCB1 single nucleotide polymorphisms (SNP), tumor MRN complex, and TOPOII alpha were analyzed. A mean of 7.4 cycles PLD were administered and TIT was 5.5 months and OS 20.6 months. ABCB1 SNPs were found to correlate to both efficacy and toxicity, while tumor expression of the MRN complex and TOPOII alpha correlated to TTP. PLD is a safe and effective treatment for elderly breast cancer patients. Also potential predictive markers were identified.
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| 7. |
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| 8. |
- Lassale, Camille, et al.
(författare)
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Separate and combined associations of obesity and metabolic health with coronary heart disease : a pan-European case-cohort analysis
- 2018
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Ingår i: European Heart Journal. - : Oxford University Press. - 0195-668X .- 1522-9645. ; 39:5, s. 397-406
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Tidskriftsartikel (refereegranskat)abstract
- Aims: The hypothesis of 'metabolically healthy obesity' implies that, in the absence of metabolic dysfunction, individuals with excess adiposity are not at greater cardiovascular risk. We tested this hypothesis in a large pan-European prospective study.Methods and results: We conducted a case-cohort analysis in the 520 000-person European Prospective Investigation into Cancer and Nutrition study ('EPIC-CVD'). During a median follow-up of 12.2 years, we recorded 7637 incident coronary heart disease (CHD) cases. Using cut-offs recommended by guidelines, we defined obesity and overweight using body mass index (BMI), and metabolic dysfunction ('unhealthy') as ≥ 3 of elevated blood pressure, hypertriglyceridaemia, low HDL-cholesterol, hyperglycaemia, and elevated waist circumference. We calculated hazard ratios (HRs) and 95% confidence intervals (95% CI) within each country using Prentice-weighted Cox proportional hazard regressions, accounting for age, sex, centre, education, smoking, diet, and physical activity. Compared with metabolically healthy normal weight people (reference), HRs were 2.15 (95% CI: 1.79; 2.57) for unhealthy normal weight, 2.33 (1.97; 2.76) for unhealthy overweight, and 2.54 (2.21; 2.92) for unhealthy obese people. Compared with the reference group, HRs were 1.26 (1.14; 1.40) and 1.28 (1.03; 1.58) for metabolically healthy overweight and obese people, respectively. These results were robust to various sensitivity analyses.Conclusion: Irrespective of BMI, metabolically unhealthy individuals had higher CHD risk than their healthy counterparts. Conversely, irrespective of metabolic health, overweight and obese people had higher CHD risk than lean people. These findings challenge the concept of 'metabolically healthy obesity', encouraging population-wide strategies to tackle obesity.
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| 9. |
- Lökk, Johan, et al.
(författare)
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Controversies around vitamin B12 in Sweden. : Attitudes and values behind clinical decision-making in primary health care 1996
- 1997
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Ingår i: Hematology. - 1024-5332 .- 1607-8454. ; 2:4, s. 341-350
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Tidskriftsartikel (refereegranskat)abstract
- Over a five-year period, 1991-1995, the vitamin B12 market in Sweden increased three-fold, from approximatelyy 2 million U.S. dollars to approximately 6 million U.S. dollars. Most prescriptions, approximately 60%, originated from primary health care. The attitudes, values and knowledge of the family physicians/general practitioners were elucidated by a questionnaire study with visuo-analogue opinion scales, evaluating 24 basic statements on problems associated with the management of vitamin B12 deficiency. The questionnaire was sent to a representative sample of 506 family physicians/general practitioners. Response rate was 74%. Dropout analysis supported the view that responders provided a representative sample of Swedish FP/GPs. Analysis of the answers was compatible with the hypothesis that the mentioned increase in Swedish B12 market reflected increased awareness in primary health care about the biochemical, pathophysiological and social problems associated with vitamin B12 deficiency.
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