| 1. |
- Abrahamsson, Christoffer, et al.
(författare)
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Time and wavelength resolved spectroscopy of turbid media using light continuum generated in a crystal fiber
- 2004
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Ingår i: Optics Express. - 1094-4087. ; 12:17, s. 4103-4112
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Tidskriftsartikel (refereegranskat)abstract
- We report a novel system for time-resolved diffuse remission spectral measurements, based on short light continuum pulses generated in an index-guided crystal fiber, and a spectrometer-equipped streak camera. The system enables spectral recordings of absorption and reduced scattering coefficients of turbid media in the wavelength range 500 - 1200 nm with a spectral resolution of 5 nm and a temporal resolution of 30 ps. The optical properties are calculated by fitting the solution of the diffusion equation to the time-dispersion curve at each wavelength. Example measurements are presented from an apple, a finger and a pharmaceutical tablet. (C) 2004 Optical Society of America.
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| 2. |
- Adolphi, Florian, et al.
(författare)
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Connecting the Greenland ice-core and U/Th timescales via cosmogenic radionuclides : Testing the synchroneity of Dansgaard-Oeschger events
- 2018
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Ingår i: Climate of the Past. - : Copernicus GmbH. - 1814-9324 .- 1814-9332. ; 14:11, s. 1755-1781
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Tidskriftsartikel (refereegranskat)abstract
- During the last glacial period Northern Hemisphere climate was characterized by extreme and abrupt climate changes, so-called Dansgaard-Oeschger (DO) events. Most clearly observed as temperature changes in Greenland ice-core records, their climatic imprint was geographically widespread. However, the temporal relation between DO events in Greenland and other regions is uncertain due to the chronological uncertainties of each archive, limiting our ability to test hypotheses of synchronous change. In contrast, the assumption of direct synchrony of climate changes forms the basis of many timescales. Here, we use cosmogenic radionuclides (10Be, 36Cl, 14C) to link Greenland ice-core records to U=Th-dated speleothems, quantify offsets between the two timescales, and improve their absolute dating back to 45 000 years ago. This approach allows us to test the assumption that DO events occurred synchronously between Greenland ice-core and tropical speleothem records with unprecedented precision. We find that the onset of DO events occurs within synchronization uncertainties in all investigated records. Importantly, we demonstrate that local discrepancies remain in the temporal development of rapid climate change for specific events and speleothems. These may either be related to the location of proxy records relative to the shifting atmospheric fronts or to underestimated U=Th dating uncertainties. Our study thus highlights the potential for misleading interpretations of the Earth system when applying the common practice of climate wiggle matching.
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| 3. |
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| 4. |
- Andersson, Gunnar, et al.
(författare)
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Minnesord: Thomas Brante 1947–2016
- 2016
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Ingår i: Sociologisk forskning. - : Sveriges Sociologförbund. - 0038-0342 .- 2002-066X. ; 53:4, s. 437-442
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 5. |
- Andersson, Mats, et al.
(författare)
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Flexible lock-in detection system based on synchronized computer plug-in boards applied in sensitive gas spectroscopy
- 2007
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Ingår i: Review of Scientific Instruments. - : AIP Publishing. - 1089-7623 .- 0034-6748. ; 78:11
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Tidskriftsartikel (refereegranskat)abstract
- We present a flexible and compact, digital, lock-in detection system and its use in high-resolution tunable diode laser spectroscopy. The system involves coherent sampling, and is based on the synchronization of two data acquisition cards running on a single standard computer. A software-controlled arbitrary waveform generator is used for laser modulation, and a four-channel analog/digital board records detector signals. Gas spectroscopy is performed in the wavelength modulation regime. The coherently detected signal is averaged a selected number of times before it is stored or analyzed by software-based, lock-in techniques. Multiple harmonics of the modulation signal 1f, 2f, 3f, 4f, etc. are available in each single data set. The sensitivity is of the order of 10−5, being limited by interference fringes in the measurement setup. The capabilities of the system are demonstrated by measurements of molecular oxygen in ambient air, as well as dispersed gas in scattering materials, such as plants and human tissue.
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| 6. |
- Awad, Akil, et al.
(författare)
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Transnasal Evaporative Cooling in Out-of-Hospital Cardiac Arrest Patients to Initiate Hypothermia—A Substudy of the Target Temperature Management 2 (TTM2) Randomized Trial
- 2023
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Ingår i: Journal of Clinical Medicine. - 2077-0383. ; 12:23
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Tidskriftsartikel (refereegranskat)abstract
- Background: In animal models, early initiation of therapeutic cooling, intra-arrest, or restored circulation has been shown to be neuroprotective shortly after cardiac arrest. We aimed to assess the feasibility and cooling efficacy of transnasal evaporative cooling, initiated as early as possible after hospital arrival in patients randomized to cooling in the TTM2 trial. Methods: This study took the form of a single-center (Södersjukhuset, Stockholm) substudy of the TTM2 trial (NCT02908308) comparing target temperature management (TTM) to 33 °C versus normothermia in OHCA. In patients randomized to TTM33 °C, transnasal evaporative cooling was applied as fast as possible. The primary objectives were the feasibility aspects of initiating cooling in different hospital locations (i.e., in the emergency department, coronary cathlab, intensive care unit (ICU), and during intrahospital transport) and its effectiveness (i.e., time to reach target temperature). Transnasal cooling was continued for two hours or until patients reached a core temperature of <34 °C. Cooling intervals were compared to participants at the same site who were randomized to hypothermia and treated at 33 °C but who for different reasons did not receive transnasal evaporative cooling. Results: From October 2018 to January 2020, 32 patients were recruited, of which 17 were randomized to the TTM33. Among them, 10 patients (8 men, median age 69 years) received transnasal evaporative cooling prior to surface systemic cooling in the ICU. In three patients, cooling was started in the emergency department; in two patients, it was started in the coronary cathlab, and in five patients, it was started in the ICU, of which three patients were subsequently transported to the coronary cathlab or to perform a CT scan. The median time to initiate transnasal cooling from randomization was 9 min (range: 5 to 39 min). The median time from randomization to a core body temperature of 34 °C was 120 min (range 60 to 334) compared to 178 min among those in the TTM33 group that did not receive TNEC and to 33 °C 230 min (range: 152 to 351) vs. 276 min (range: 150 to 546). No feasibility or technical issues were reported. No adverse events occurred besides minor nosebleeds. Conclusions: The early induction of transnasal cooling in out-of-hospital cardiac arrest patients was feasible to initiate in the emergency department, coronary cathlab, ICU, and during intrahospital transport. Time to target temperature was shortened compared to standard cooling.
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| 7. |
- Barup, Kerstin, et al.
(författare)
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Multi-disciplinary lidar applications
- 2010
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Ingår i: Laser Applications to Chemical, Security and Environmental Analysis, LACSEA 2010. - 2162-2701. - 9781557528803
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Konferensbidrag (refereegranskat)abstract
- Lidar is a powerful technique normally associated with atmospheric monitoring. However, lidar techniques, also of the laser-induced fluorescence and laser-induced breakdown spectroscopy varieties, provide many new possibilities in unconventional fields including cultural heritage and ecological applications.
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| 8. |
- Bendsoe, Niels, et al.
(författare)
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Fluorescence monitoring of a topically applied liposomal temoporfin formulation and photodynamic therapy of nonpigmented skin malignancies.
- 2007
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Ingår i: Journal of Environmental Pathology and Toxicology. - 2162-6537. ; 26:2, s. 117-126
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Tidskriftsartikel (refereegranskat)abstract
- Meso-tetra(hydroxyphenyl)chlorin (mTHPC) (INN: Temoporfin) is a potent photodynamically active substance in clinical use today. Usually, the substance is given systemically and a known drawback with this administration route is a prolonged skin light sensitization. For the first time to our knowledge, a liposomal Temoporfin gel formulation for topical application was studied in connection with photodynamic therapy (PDT) of nonpigmented skin malignancies in humans. Intervals of 4 hr between drug administration and light irradiation were used. Sensitizer distribution within tumor and surrounding normal skin was investigated by means of point monitoring and imaging fluorescence spectroscopy before, during, and after PDT, showing high tumor selectivity. Furthermore, the bleaching of Temoporfin was studied during the PDT procedure by monitoring the fluorescence following excitation by using a therapeutic light. A 30−35% light-induced photometabolization was shown. No pain occurred during or after treatment. It was also observed that the treated area did not show any swollen tissue or reddening, as is often seen in PDT using topical δ-aminolevulinic acid. On controlling the patients one week after treatment, healing progress was observed in several patients and no complications were registered.
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| 9. |
- Berglund, Ellinor, et al.
(författare)
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Effect of Smartphone Dispatch of Volunteer Responders on Automated External Defibrillators and Out-of-Hospital Cardiac Arrests : The SAMBA Randomized Clinical Trial
- 2023
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Ingår i: JAMA cardiology. - : American Medical Association (AMA). - 2380-6583 .- 2380-6591. ; 8:1, s. 81-88
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Tidskriftsartikel (refereegranskat)abstract
- Importance Smartphone dispatch of volunteer responders to nearby out-of-hospital cardiac arrests (OHCAs) has emerged in several emergency medical services, but no randomized clinical trials have evaluated the effect on bystander use of automated external defibrillators (AEDs).Objective To evaluate if bystander AED use could be increased by smartphone-aided dispatch of lay volunteer responders with instructions to collect nearby AEDs compared with instructions to go directly to patients with OHCAs to start cardiopulmonary resuscitation (CPR).Design, Setting, and Participants This randomized clinical trial assessed a system for smartphone dispatch of volunteer responders to individuals experiencing OHCAs that was triggered at emergency dispatch centers in response to suspected OHCAs and randomized 1:1. The study was conducted in 2 main Swedish regions: Stockholm and Västra Götaland between December 2018 and January 2020. At study start, there were 3123 AEDs in Stockholm and 3195 in Västra Götaland and 24 493 volunteer responders in Stockholm and 19 117 in Västra Götaland. All OHCAs in which the volunteer responder system was activated by dispatchers were included. Excluded were patients with no OHCAs, those with OHCAs not treated by the emergency medical services, and those with OHCAs witnessed by the emergency medical services.Interventions Volunteer responders were alerted through the volunteer responder system smartphone application and received map-aided instructions to retrieve nearest available public AEDs on their way to the OHCAs. The control arm included volunteer responders who were instructed to go directly to the OHCAs to perform CPR.Main Outcomes and Measures Overall bystander AED attachment, including those attached by volunteer responders and lay volunteers who did not use the smartphone application.Results Volunteer responders were activated for 947 patients with OHCAs. Of those, 461 were randomized to the intervention group (median [IQR] age of patients, 73 [61-81] years; 295 male patients [65.3%]) and 486 were randomized to the control group (median [IQR] age of patients, 73 [63-82] years; 312 male patients [65.3%]). Primary outcome of AED attachment occurred in 61 patients (13.2%) in the intervention arm vs 46 patients (9.5%) in the control arm (difference, 3.8% [95% CI, −0.3% to 7.9%]; P = .08). The majority of AEDs were attached by lay volunteers who were not using the smartphone application (37 in intervention arm, 28 in control). There were no significant differences in secondary outcomes. Among the volunteer responders using the application, crossover was 11% and compliance to instructions was 31%. Volunteer responders attached 38% (41 of 107) of all AEDs and provided 45% (16 of 36) of all defibrillations and 43% (293 of 666) of all CPR.Conclusions and Relevance In this study, smartphone dispatch of volunteer responders to OHCAs to retrieve nearby AEDs vs instructions to directly perform CPR did not significantly increase volunteer AED use. High baseline AED attachement rate and crossover may explain why the difference was not significant.Trial Registration ClinicalTrials.gov Identifier: NCT02992873
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| 10. |
- Börjesson, Sara, et al.
(författare)
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A software tool for increased efficiency in observer performance studies in radiology.
- 2005
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Ingår i: Radiation protection dosimetry. - : Oxford University Press (OUP). - 0144-8420 .- 1742-3406. ; 114:1-3, s. 45-52
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Tidskriftsartikel (refereegranskat)abstract
- Observer performance studies are time-consuming tasks, both for the participating observers and for the scientists collecting and analysing the data. A possible way to optimise such studies is to perform them in a completely digital environment. A software tool-ViewDEX (Viewer for Digital Evaluation of X-ray images)-has been developed in Java, enabling it to function on almost any computer. ViewDEX is designed to handle several types of studies, such as visual grading analysis (VGA), image criteria scoring (ICS) and receiver operating characteristics (ROC). The results from each observer are saved in a log file, which can be exported for further analysis in, for example, a special software for analysing ROC results. By using ViewDEX for an ROC experiment, an evaluation rate of approximately 200 images per hour can be achieved, compared to approximately 25 images per hour using hard copy evaluation. The results are obtained within minutes of completion of the viewing. The risk of human errors in the process of data collection and analysis is also minimised. The viewer has been used in a major trial containing approximately 2700 images.
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| 11. |
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| 12. |
- Chauchard, F, et al.
(författare)
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Least-squares support vector machines modelization for time-resolved spectroscopy
- 2005
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Ingår i: Applied Optics. - 2155-3165. ; 44:33, s. 7091-7097
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Tidskriftsartikel (refereegranskat)abstract
- By use of time-resolved spectroscopy it is possible to separate light scattering effects from chemical absorption effects in samples. In the study of propagation of short light pulses in turbid samples the reduced scattering coefficient and the absorption coefficient are usually obtained by fitting diffusion or Monte Carlo models to the measured data by use of numerical optimization techniques. In this study we propose a prediction model obtained with a semiparametric modeling technique: the least-squares support vector machines. The main advantage of this technique is that it uses theoretical time dispersion curves during the calibration step. Predictions can then be performed by use of data measured on different kinds of sample, such as apples.
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| 13. |
- Claesson, Andreas, et al.
(författare)
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Simulation and education Outline and validation of a new dispatcher-assisted cardiopulmonary resuscitation educational bundle using the Delphi method
- 2024
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Ingår i: Resuscitation Plus. - : ELSEVIER. - 2666-5204. ; 17
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Tidskriftsartikel (refereegranskat)abstract
- Aim: Dispatcher-assisted cardiopulmonary resuscitation (DA-CPR) is time-dependent. To date, evidence-based training programmes for dispatchers are lacking. This study aimed to reach expert consensus on an educational bundle content for dispatchers to provide DA-CPR using the Delphi Method: An educational bundle was created by the Swedish Resuscitation Council consisting of three parts: e-learning on DA-CPR, basic life support training and audit of emergency out-of-hospital cardiac arrest calls. Thereafter, a two-round modified Delphi study was conducted between November 2022 and March 2023; 37 experts with broad clinical and/or scientific knowledge of DA-CPR were invited. In the first round, the experts participated in the e-learning module and answered a questionnaire with 13 closed and open questions, whereafter the e-learning part of the bundle was revised. In the second round, the revised e-learning part was evaluated using Likert scores (20 items). The predefined consensus level was set Results: Delphi rounds one and two were assessed by 20 and 18 of the invited experts, respectively. In round one, 18 experts (18 of 20, 90%) stated that they did not miss any content in the programme. In round two, the scale-level content validity index based on the average method (S-CVI/AVE, 0.99) and scale-level content validity index based on universal agreement (S-CVI/UA, 0.85) exceeded the threshold level of 80%. Conclusion: Expert consensus on the educational bundle content was reached using the Delphi method. Further work is required to evaluate its effect in real-world out-of-hospital cardiac arrest calls.
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| 14. |
- Dillenbeck, Emelie, et al.
(författare)
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The design of the PRINCESS 2 trial: A randomized trial to study the impact of ultrafast hypothermia on complete neurologic recovery after out-of-hospital cardiac arrest with initial shockable
- 2024
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Ingår i: American Heart Journal. - : MOSBY-ELSEVIER. - 0002-8703 .- 1097-6744. ; 271, s. 97-108
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Tidskriftsartikel (refereegranskat)abstract
- Background Delayed hypothermia, initiated after hospital arrival, several hours after cardiac arrest with 8-10 hours to reach the target temperature, is likely to have limited impact on overall survival. However, the effect of ultrafast hypothermia, i.e., delivered intra-arrest or immediately after return of spontaneous circulation (ROSC), on functional neurologic outcome after out -of -hospital cardiac arrest (OHCA) is unclear. In two prior trials, prehospital trans -nasal evaporative intra-arrest cooling was safe, feasible and reduced time to target temperature compared to delayed cooling. Both studies showed trends towards improved neurologic recovery in patients with shockable rhythms. The aim of the PRINCESS2-study is to assess whether cooling, initiated either intra-arrest or immediately after ROSC, followed by in -hospital hypothermia, significantly increases survival with complete neurologic recovery as compared to standard normothermia care, in OHCA patients with shockable rhythms. Methods/design In this investigator -initiated, randomized, controlled trial, the emergency medical services (EMS) will randomize patients at the scene of cardiac arrest to either trans -nasal cooling within 20 minutes from EMS arrival with subsequent hypothermia at 33 degrees C for 24 hours after hospital admission (intervention), or to standard of care with no prehospital or in -hospital cooling (control). Fever ( > 37,7 degrees C) will be avoided for the first 72 hours in both groups. All patients will receive post resuscitation care and withdrawal of life support procedures according to current guidelines. Primary outcome is survival with complete neurologic recovery at 90 days, defined as modified Rankin scale (mRS) 0-1. Key secondary outcomes include survival to hospital discharge, survival at 90 days and mRS 0-3 at 90 days. In total, 1022 patients are required to detect an absolute difference of 9% (from 45 to 54%) in survival with neurologic recovery (80% power and one-sided alpha= 0,025, beta = 0,2) and assuming 2,5% lost to follow-up. Recruitment starts in Q1 2024 and we expect maximum enrolment to be achieved during Q4 2024 at 20-25 European and US sites. Discussion This trial will assess the impact of ultrafast hypothermia applied on the scene of cardiac arrest, as compared to normothermia, on 90 -day survival with complete neurologic recover y in OHCA patients with initial shockable rhythm. Trial registration NCT06025123. (Am Heart J 2024;271:97-108.)
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| 15. |
- Guan, Zuguang, et al.
(författare)
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Insect monitoring with fluorescence lidar techniques: field experiments.
- 2010
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Ingår i: Applied Optics. - 2155-3165. ; 49:27, s. 5133-5142
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Tidskriftsartikel (refereegranskat)abstract
- Results from field experiments using a fluorescence lidar system to monitor movements of insects are reported. Measurements over a river surface were made at distances between 100 and 300 m, detecting, in particular, damselflies entering the 355 nm pulsed laser beam. The lidar system recorded the depolarized elastic backscattering and two broad bands of laser-induced fluorescence, with the separation wavelength at 500 nm. Captured species, dusted with characteristic fluorescent dye powders, could be followed spatially and temporally after release. Implications for ecological research are discussed.
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| 16. |
- Hulsart Billström, Gry, 1982-
(författare)
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Bone Regeneration with Cell-free Injectable Scaffolds
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Bone is a remarkable multifunctional tissue with the ability to regenerate and remodel without generating any scar tissue. However, bone loss due to injury or diseases can be a great challenge and affect the patient significantly. Autologous bone grafting is commonly used throughout the world. Autograft both fills the void and is bone inductive, housing the particular cells that are needed for bone regeneration. However, a regenerative complement to autograft is of great interest as the use of biomaterials loaded with bioactive molecules can avoid donor site morbidity and the problem of a limited volume of material. Two such regenerative products that utilise bone morphogenetic protein (BMP)-7 and -2 have been used for more than a decade clinically. Unfortunately, several side effects have been reported, such as severe swelling due to inflammation and ectopic bone formation. Additionally, the products require open surgery and use of supra physiological doses of the BMPs due to poor localisation and retention of the growth factor. The purpose of this thesis was to harness the strong inductive capacity of the BMP-2 by optimising the carrier of this bioactive protein, thereby minimising the side effects that are associated with the clinical products and facilitating safe and localised bone regeneration. We focused on an injectable hyaluronan-based carrier developed through polymer chemistry at the University of Uppsala. The strategy was to use the body’s own regenerative pathway to stimulate and enhance bone healing in a manner similar to the natural bone-healing process. The hyaluronan-based carrier has a similar composition to the natural extracellular matrix and is degraded by resident enzymes. Earlier studies have shown improved properties when adding hydroxyapatite, a calcium phosphate that constitutes the inorganic part of the bone matrix. In Paper I, the aim was to improve the carrier by adding other forms of calcium phosphate. The results indicated that bone formation was enhanced when using nano-sized hydroxyapatite. In Paper II, we discovered the importance of crushing the material, thus enhancing permeability and enlarging the surface area. We wished to further develop the carrier system, but were lacking an animal model with relatively high throughput, facilitated access, paired data, and we were also committed to the 3Rs of refinement, reduction, and replacement. To meet these challenges, we developed and refined an animal model, and this is described in Paper III. In Paper IV, we sought to further optimise the biomaterial properties of the hydrogel through covalent bonding of bisphosphonates to the hyaluronan hydrogel. This resulted in exceptional retention of the growth factor BMP-2. In Paper V, SPECT/PET/µCT was combined as a tri-modal imaging method to allow visualisation of the biomaterial’s in situ action, in terms of drug retention, osteoblast activity and mineralisation. Finally, in Paper VI the correlation between existing in vitro results with in vivo outcomes was observed for an array of biomaterials. The study identified a surprisingly poor correlation between in vitro and in vivo assessment of biomaterials for osteogenesis.
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| 17. |
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| 18. |
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| 19. |
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| 20. |
- Håkansson, Markus, et al.
(författare)
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ViewDEX: an efficient and easy-to-use software for observer performance studies
- 2010
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Ingår i: Radiation protection dosimetry. - : Oxford University Press (OUP). - 1742-3406 .- 0144-8420. ; 139:1-3, s. 42-51
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Tidskriftsartikel (refereegranskat)abstract
- The development of investigation techniques, image processing, workstation monitors, analysing tools etc. within the field of radiology is vast, and the need for efficient tools in the evaluation and optimisation process of image and investigation quality is important. ViewDEX (Viewer for Digital Evaluation of X-ray images) is an image viewer and task manager suitable for research and optimisation tasks in medical imaging. ViewDEX is DICOM compatible and the features of the interface (tasks, image handling and functionality) are general and flexible. The configuration of a study and output (for example, answers given) can be edited in any text editor. ViewDEX is developed in Java and can run from any disc area connected to a computer. It is free to use for non-commercial purposes and can be downloaded from http://www.vgregion.se/sas/viewdex. In the present work, an evaluation of the efficiency of ViewDEX for receiver operating characteristic (ROC) studies, free-response ROC (FROC) studies and visual grading (VG) studies was conducted. For VG studies, the total scoring rate was dependent on the number of criteria per case. A scoring rate of approximately 150 cases h(-1) can be expected for a typical VG study using single images and five anatomical criteria. For ROC and FROC studies using clinical images, the scoring rate was approximately 100 cases h(-1) using single images and approximately 25 cases h(-1) using image stacks ( approximately 50 images case(-1)). In conclusion, ViewDEX is an efficient and easy-to-use software for observer performance studies.
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| 21. |
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| 24. |
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| 25. |
- Laanemets, Leili, et al.
(författare)
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Socialtjänstens arbete med missbrukare
- 2006
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Ingår i: Att forska om och i praktiken. - 0282-6143. ; :6, s. 61-88
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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