Change search
Refine search result
2345678 201 - 250 of 1085
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 201. Eissler, N.
    et al.
    Mao, Y.
    Brodin, D.
    Reuterswärd, Philippa
    KTH, School of Biotechnology (BIO), Proteomics and Nanobiotechnology.
    Svahn Andersson, Helene
    KTH, School of Biotechnology (BIO), Proteomics and Nanobiotechnology.
    Johnsen, J. I.
    Kiessling, R.
    Kogner, P.
    Combination Therapy of Anti-PD-1 Antibody and CSF-1R Inhibitor Reverses Induction of Suppressive Myeloid Cells and Controls Spontaneous Neuroblastoma Progression2016In: Pediatric Blood & Cancer, ISSN 1545-5009, E-ISSN 1545-5017, Vol. 63, p. S28-S28Article in journal (Refereed)
  • 202. Ekstrand, E. E.
    et al.
    Gustafsson, A. G.
    Norhammar, A. N.
    Näsman, Per N.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport Planning, Economics and Engineering.
    Ryden, L. R.
    Kjellstrom, B. K.
    Periodontal disease: A potential risk factor for myocardial infarction in younger women2016In: EUROPEAN HEART JOURNAL, ISSN 0195-668X, Vol. 37, p. 350-350Article in journal (Refereed)
  • 203. Ekstrand, E
    et al.
    Gustafsson, A
    Norhammar, A
    Näsman, Per
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Transport Studies, CTS.
    Ryden, L
    Kjellström, B
    Periodontal disease - a potential risk factor for myocardial infarction in younger women.2016In: Svenska Hjärtförbundet, no 128Article in journal (Other academic)
  • 204.
    Elmstedt, Nina
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering.
    Lind, Britta
    KTH, School of Technology and Health (STH), Medical Engineering.
    Ferm-Widlund, K.
    Westgren, M.
    Brodin, Lars-Åke
    KTH, School of Technology and Health (STH), Medical Engineering.
    Fetal heart contractile function and gestational age2012In: Cardiovascular Research, ISSN 0008-6363, E-ISSN 1755-3245, Vol. 93, p. S108-S108Article in journal (Other academic)
  • 205. Emri, M.
    et al.
    Opposits, G.
    Kis, S. A.
    Trón, L.
    Veres, P.
    Pányik, Á.
    Valastyán, I.
    Imrek, J.
    Moinar, J.
    Novák, D.
    Kerek, Andras
    KTH, School of Technology and Health (STH), Medical Engineering.
    Balkay, L.
    Software development framework supporting multimodal tomographic imaging2007In: 2006 IEEE Nuclear Science Symposium Conference Record, IEEE , 2007, p. 1857-1859Conference paper (Refereed)
    Abstract [en]

    Engineers specialized in multimodal tomography regularly face a wide scale of programming tasks requiring an integrated software system to ensure cost efficiency. Accordingly, a software development framework has been worked out comprising libraries for cluster-based data acquisition, image reconstruction, management of data files and complex multimodal volumetric visualization. This framework enabled us to develop complex software for our miniPET project [1]. This software contains a graphical application integrating data acquisition, cluster monitoring, event sorting, image reconstruction, interactive image processing tools for advanced multimodal visualization. It also contains utilities to solve these tasks without graphical user interface. The components of our acquisition program can run on embedded Linux systems making new ways to develop any other types of data acquisition software that uses embedded Linux systems. A versatile development framework is developed containing specific libraries and special file formats that support multimodal tomography. This framework was successfully used to elaborate our complex miniPET software.

  • 206.
    Enflo, Laura
    et al.
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH.
    Sundberg, Johan
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH.
    McAllister, Anita
    Collision and Phonation Threshold Pressures Before and After Loud, Prolonged Vocalization in Trained and Untrained Voices2013In: Journal of Voice, ISSN 0892-1997, E-ISSN 1873-4588, Vol. 27, no 5, p. 527-530Article in journal (Refereed)
    Abstract [en]

    The phonation threshold pressure (PTP) is defined as the lowest subglottal pressure needed for obtaining and sustaining vocal fold oscillation. It has been found to increase during vocal fatigue. In the present study, PTP is measured together with the threshold pressure needed for vocal fold collision; henceforth, the collision threshold pressure (CTP). PTP and CTP are compared before and after loud, prolonged vocalization in singer and nonsinger voices. Ten subjects repeated the vowel sequence /a, e, i, o, u/ at a Sound Pressure Level of at least 80 dB at 0.3 m for 20 minutes. Audio and electroglottography signals were recorded before and after this exercise. At the same time, oral pressure was registered while the subjects produced a diminuendo repeating the syllable /pa:/, thus acquiring an approximate of the subglottal pressure. CTP and PTP increased significantly after the vocal loading in the nonsinger subjects. On the other hand, singers reported no substantial effect of the exercise, and most singers had a mean after-to-before ratio close to 1 for both CTP and PTP.

  • 207.
    Engberg, L.
    et al.
    Raysearch Labs AB, Res Dept, Stockholm, Sweden..
    Eriksson, K.
    Raysearch Labs AB, Res Dept, Stockholm, Sweden..
    Forsgren, Anders
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.).
    Automated planning through explicit optimization of plan quality2018In: Radiotherapy and Oncology, ISSN 0167-8140, E-ISSN 1879-0887, Vol. 127, p. S1025-S1026Article in journal (Other academic)
  • 208.
    Engberg, Lovisa
    et al.
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.), Optimization and Systems Theory.
    Forsgren, Anders
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.), Optimization and Systems Theory.
    Eriksson, Kjell
    Hardemark, Bjorn
    Explicit optimization of plan quality measures in intensity-modulated radiation therapy treatment planning2017In: Medical physics (Lancaster), ISSN 0094-2405, Vol. 44, no 6, p. 2045-2053Article in journal (Refereed)
    Abstract [en]

    Purpose: To formulate convex planning objectives of treatment plan multicriteria optimization with explicit relationships to the dose-volume histogram (DVH) statistics used in plan quality evaluation. Methods: Conventional planning objectives are designed to minimize the violation of DVH statistics thresholds using penalty functions. Although successful in guiding the DVH curve towards these thresholds, conventional planning objectives offer limited control of the individual points on the DVH curve (doses-at-volume) used to evaluate plan quality. In this study, we abandon the usual penalty-function framework and propose planning objectives that more closely relate to DVH statistics. The proposed planning objectives are based on mean-tail-dose, resulting in convex optimization. We also demonstrate how to adapt a standard optimization method to the proposed formulation in order to obtain a substantial reduction in computational cost. Results: We investigated the potential of the proposed planning objectives as tools for optimizing DVH statistics through juxtaposition with the conventional planning objectives on two patient cases. Sets of treatment plans with differently balanced planning objectives were generated using either the proposed or the conventional approach. Dominance in the sense of better distributed doses-at-volume was observed in plans optimized within the proposed framework. Conclusion: The initial computational study indicates that the DVH statistics are better optimized and more efficiently balanced using the proposed planning objectives than using the conventional approach.

  • 209.
    Engfeldt, Torun
    et al.
    KTH, School of Biotechnology (BIO), Molecular Biotechnology.
    Orlova, Anna
    Biomedical Radiation Sciences, Rudbeck Laboratory, Uppsala University.
    Tran, Thuy
    Biomedical Radiation Sciences, Rudbeck Laboratory, Uppsala University.
    Bruskin, Alexander
    Biomedical Radiation Sciences, Rudbeck Laboratory, Uppsala University.
    Widström, Charles
    Department of Hospital Physics, Uppsala University Hospital.
    Eriksson Karlström, Amelie
    KTH, School of Biotechnology (BIO), Molecular Biotechnology.
    Tolmachev, Vladimir
    Biomedical Radiation Sciences, Rudbeck Laboratory, Uppsala University.
    Imaging of HER2-expressing tumours using a synthetic Affibody molecule containing the 99mTc-chelating mercaptoacetyl-glycyl-glycyl-glycyl (MAG3) sequence2007In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 34, no 5, p. 722-733Article in journal (Refereed)
    Abstract [en]

    Purpose  Expression of human epidermal growth factor receptor type 2 (HER2) in malignant tumours possesses well-documented prognostic and predictive value. Non-invasive imaging of expression can provide valuable diagnostic information, thereby influencing patient management. Previously, we reported a phage display selection of a small (about 7 kDa) protein, the Affibody molecule ZHER2:342, which binds HER2 with subnanomolar affinity, and demonstrated the feasibility of targeting of HER2-expressing xenografts using radioiodinated ZHER2:342. The goal of this study was to develop a method for 99mTc labelling of ZHER2:342 using the MAG3 chelator, which was incorporated into ZHER2:342 using peptide synthesis, and evaluate the targeting properties of the labelled conjugate. Methods  MAG3-ZHER2:342 was assembled using Fmoc/tBu solid phase peptide synthesis. Biochemical characterisation of the agent was performed using RP-HPLC, ESI-MS, biosensor studies and circular dichroism. A procedure for 99mTc labelling in the presence of sodium/potassium tartrate was established. Tumour targeting was evaluated by biodistribution study and gamma camera imaging in xenograft-bearing mice. Biodistribution of 99mTc-MAG3-ZHER2:342 and 125I-para-iodobenzoate -ZHER2:342 was compared 6 h p.i. Results  Synthetic MAG3-ZHER2:342 possessed an affinity of 0.2 nM for HER2 receptors. The peptide was labelled with 99mTc with an efficiency of about 75–80%. Labelled 99mTc-MAG3-ZHER2:342 retained capacity to bind specifically HER2-expressing SKOV-3 cells in vitro. 99mTc-MAG3-ZHER2:342 showed specific tumour targeting with a contrast similar to a radioiodinated analogue in mice bearing LS174T xenografts. Gamma camera imaging demonstrated clear and specific visualisation of HER2 expression. Conclusion  Incorporation of a mercaptoacetyl-containing chelating sequence during chemical synthesis enabled site-specific 99mTc labelling of the ZHER2:342 Affibody molecule with preserved targeting capacity.

  • 210.
    Engfeldt, Torun
    et al.
    KTH, School of Biotechnology (BIO).
    Tran, Thuy
    Unit of Biomedical Radiation Sciences, Rudbeck Laboratory, Uppsala University.
    Orlova, Anna
    Unit of Biomedical Radiation Sciences, Rudbeck Laboratory, Uppsala University.
    Widström, Charles
    Section of Hospital Physics, Department of Oncology, Uppsala University Hospital.
    Feldwisch, Joachim
    Unit of Biomedical Radiation Sciences, Rudbeck Laboratory, Uppsala University.
    Abrahmsén, Lars
    Affibody AB, Bromma.
    Wennborg, Anders
    Affibody AB, Bromma.
    Eriksson Karlström, Amelie
    KTH, School of Biotechnology (BIO).
    Tolmachev, Vladimir
    Unit of Biomedical Radiation Sciences, Rudbeck Laboratory, Uppsala University.
    99mTc-chelator engineering to improve tumour targeting properties of a HER2-specific Affibody molecule2007In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 34, no 11, p. 1843-1853Article in journal (Refereed)
    Abstract [en]

    Purpose  Monitoring HER2 expression is crucial for selection of breast cancer patients amenable to HER2-targeting therapy. The Affibody molecule ZHER2:342 binds to HER2 with picomolar affinity and enables specific imaging of HER2 expression. Previously, ZHER2:342 with the additional N-terminal mercaptoacetyl-glycyl-glycyl-glycyl (maGGG) sequence was labelled with 99mTc and demonstrated specific targeting of HER2-expressing xenografts. However, hepatobiliary excretion caused high radioactivity accumulation in the abdomen. We investigated whether the biodistribution of ZHER2:342 can be improved by substituting glycyl residues in the chelating sequence with more hydrophilic seryl residues.

    Methods  The Affibody molecule ZHER2:342, carrying the chelators mercaptoacetyl-glycyl-seryl-glycyl (maGSG), mercaptoacetyl-glycyl-D-seryl-glycyl [maG(D-S)G] and mercaptoacetyl-seryl-seryl-seryl (maSSS), were prepared by peptide synthesis and labelled with 99mTc. The differences in the excretion pathways were evaluated in normal mice. The tumour targeting capacity of 99mTc-maSSS-ZHER2:342 was studied in nude mice bearing SKOV-3 xenografts and compared with the capacity of radioiodinated ZHER2:342.

    Results  A shift towards renal excretion was obtained when glycine was substituted with serine in the chelating sequence. The radioactivity in the gastrointestinal tract was reduced threefold for the maSSS conjugate in comparison with the maGGG conjugate 4 h post injection (p.i.). The tumour uptake of 99mTc-maSSS-ZHER2:342 was 11.5 ± 0.5% IA/g 4 h p.i., and the tumour-to-blood ratio was 76. The pharmacokinetics and uptake characteristics of technetium-labelled ZHER2:342 were better than those of radioiodinated ZHER2:342.

    Conclusion  The introduction of serine residues in the chelator results in better tumour imaging properties of the Affibody molecule ZHER2:342 compared with glycyl-containing chelators and is favourable for imaging of tumours and metastases in the abdominal area.

  • 211.
    Engkvist, Inga-Lill
    et al.
    KTH, School of Technology and Health (STH), Ergonomics.
    Svensson, R.
    Eklund, Jörgen
    KTH, School of Technology and Health (STH), Ergonomics.
    Reported occupational injuries at Swedish recycling centres - based on official statistics2011In: Ergonomics, ISSN 0014-0139, E-ISSN 1366-5847, Vol. 54, no 4, p. 357-366Article in journal (Refereed)
    Abstract [en]

    Swedish recycling centres are manned facilities for waste collection. There is no special category in the official injury statistics for employees at recycling centres, which precludes a straightforward analysis of reported occupational injuries. This study aimed at identifying the frequency of reported accidents and diseases and the type of events that contribute to such injuries at recycling centres, based on official injury statistics. The employees were identified as being affected by more than three to five times as many accidents compared with the total workforce in Sweden. The reported accidents had occurred during a wide range of situations, but most frequently during manual handling of waste. Reported work-related diseases were mostly associated with musculoskeletal disorders, mainly due to heavy lifting. A more detailed classification of sanitation professions and workplaces in the official injury statistics would facilitate future studies of injuries in a specific professional category, e.g. employees at recycling centres. Suggestions for prevention are given. Statement of Relevance: The present article describes all reported work accidents and diseases among employees at recycling centres from 1992 to February 2005. It also highlights the problem of identifying new working groups in the official statistics and gives advice for a detailed classification to facilitate such future studies of injuries.

  • 212.
    Engström, Emma
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering, Environmental Management and Assessment.
    Comparison of power spectra for tomosynthesis projections and reconstructed images2009In: Medical physics (Lancaster), ISSN 0094-2405, Vol. 36, no 5, p. 1753-1758Article in journal (Refereed)
    Abstract [en]

    Burgess [Med. Phys. 28, 419-437 (2001)] showed that the power spectrum of mammographic breast background follows a power law and that lesion detectability is affected by the power-law exponent beta which measures the amount of structure in the background. Following the study of Burgess , the authors measured and compared the power-law exponent of mammographic backgrounds in tomosynthesis projections and reconstructed slices to investigate the effect of tomosynthesis imaging on background structure. Our data set consisted of 55 patient cases. For each case, regions of interest (ROIs) were extracted from both projection images and reconstructed slices. The periodogram of each ROI was computed by taking the squared modulus of the Fourier transform of the ROI. The power-law exponent was determined for each periodogram and averaged across all ROIs extracted from all projections or reconstructed slices for each patient data set. For the projections, the mean beta averaged across the 55 cases was 3.06 (standard deviation of 0.21), while it was 2.87 (0.24) for the corresponding reconstructions. The difference in beta for a given patient between the projection ROIs and the reconstructed ROIs averaged across the 55 cases was 0.194, which was statistically significant (p < 0.001). The 95% CI for the difference between the mean value of beta for the projections and reconstructions was [0.170, 0.218]. The results are consistent with the observation that the amount of breast structure in the tomosynthesis slice is reduced compared to projection mammography and that this may lead to improved lesion detectability.

  • 213.
    Engström, Pähr
    et al.
    Karolinska Institutet, Dept. of Women's and Children's Health.
    Bartonek, Åsa
    Karolinska Institutet, Dept. of Women's and Child's Health.
    Tedroff, Kristina
    Karolinska Institutet, Dept. of Women's and Children's Health.
    Orefelt, Christina
    Karolinska Institutet, Dept. of Women's and Children's Health.
    Haglund-Åkerlind, Yvonne
    Karolinska Institutet, Dept. of Women's and Children's Health.
    Gutierrez-Farewik, Elena
    Department of Women’s and Children’s Health. Karolinska University Hospital, Sweden.
    Botulinum toxin A does not improve cast treatment for idiopathic toe-walking - a randomized controlled trial2013In: Journal of Bone and Joint Surgery. American volume, ISSN 0021-9355, E-ISSN 1535-1386, Vol. 95, no 5, p. 400-407Article in journal (Refereed)
    Abstract [en]

    Background: There are many treatments for idiopathic toe-walking, including casts with or without injection of botulinum toxin A. Combined treatment with casts and botulinum toxin A has become more common even though there have been few studies of its efficacy and safety problems. Our aims were to conduct a randomized controlled trial to test the hypotheses that combined treatment with casts and botulinum toxin A is more effective than casts alone in reducing toewalking by patients five to fifteen years of age, and that the treatment effect correlates with the extent of coexisting neuropsychiatric problems. Methods: All patients who had been consecutively admitted to the pediatric orthopaedics department of our institution because of idiopathic toe-walking between November 2005 and April 2010 were considered for inclusion in the study. Forty-seven children constituted the study population. The children were randomized to undergo four weeks of treatment with below-the-knee casts either as the sole intervention or to undergo the cast treatment one to two weeks after receiving injections of botulinum toxin A into the calves. Before treatment and three and twelve months after cast removal, all children underwent three-dimensional (3-D) gait analysis. The severity of the idiopathic toe-walking was classified on the basis of the gait analysis, and the parents rated the time that their child spent on his/her toes during barefoot walking. Passive hip, knee, and ankle motion as well as ankle dorsiflexor strength were measured. Before treatment, all children were evaluated with a screening questionnaire for neuropsychiatric problems. Results: No differences were found in any outcome parameter between the groups before treatment or at three or twelve months after cast removal. Several gait-analysis parameters, passive ankle motion, and ankle dorsiflexor strength were improved at both three and twelve months in both groups, even though many children still demonstrated some degree of toe-walking. The treatment outcomes were not correlated with coexisting neuropsychiatric problems. Conclusion: Adding botulinum toxin-A injections prior to cast treatment for idiopathic toe-walking does not improve the outcome of cast-only treatment. Level of Evidence: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

  • 214.
    Engström, Pähr
    et al.
    Karolinska Institutet, Dept. of Women's and Children's Health.
    Gutierrez-Farewik, Elena
    KTH, School of Engineering Sciences (SCI), Mechanics, Biomechanics. KTH, School of Engineering Sciences (SCI), Mechanics, Structural Mechanics.
    Bartonek, Åsa
    Karolinska Institutet, Dept. of Women's and Child's Health.
    Tedroff, Kristina
    Karolinska Institutet, Dept. of Women's and Children's Health.
    Orefelt, Christina
    Karolinska Institutet, Dept. of Women's and Children's Health.
    Haglund-Åkerlind, Yvonne
    Karolinska Institutet, Dept. of Women's and Children's Health.
    Does Botulinum toxin A improve the walking pattern in children with idiopathic toe-walking?2010In: Journal of Children's Orthopaedics, ISSN 1863-2521, Vol. 4, no 4, p. 301-308Article in journal (Refereed)
    Abstract [en]

    Background: Numerous recommendations have been made for treating idiopathic toe-walking (ITW), but the treatment results have been questioned. The purpose of this study was to investigate whether botulinum toxin A (BTX) improves the walking pattern in ITW as examined with 3-D gait analysis. Participants and methods: A consecutive series of 15 children (aged 5-13 years) were enrolled in the study. The children underwent a 3-D gait analysis prior to treatment with a total of 6 units/kg bodyweight Botox® in the calf muscles and an exercise program. The gait analysis was repeated 3 weeks and 3, 6, and 12 months after treatment. A classification of toe-walking severity was made before treatment and after 12 months. The parents rated the perceived amount of toe-walking prior to treatment and 6 and 12 months after treatment. Results: Eleven children completed the 12-month follow-up. The gait analysis results displayed a significant improvement, indicating decreased plantarflexion angle at initial contact and during swing phase and increased dorsiflexion angle during midstance at all post-treatment testing instances. According to the parents' perception of toe-walking, 3/11 children followed for 12 months had ceased toe-walking completely, 4/11 decreased toe-walking, and 4/11 continued toe-walking. After 6-12 months, the toe-walking severity classification improved in 9 of the 14 children for whom data could be assessed. Conclusions: A single injection of BTX in combination with an exercise program can improve the walking pattern in children with ITW seen at gait analysis, but the obvious goal of ceasing toe-walking is only occasionally reached.

  • 215. Ercole, A.
    et al.
    Thelin, E. P.
    Holst, Anders
    KTH, School of Computer Science and Communication (CSC), Computational Science and Technology (CST).
    Bellander, B. M.
    Nelson, D. W.
    Kinetic modelling of serum S100b after traumatic brain injury2016In: BMC Neurology, ISSN 1471-2377, E-ISSN 1471-2377, Vol. 16, article id 93Article in journal (Refereed)
    Abstract [en]

    Background: An understanding of the kinetics of a biomarker is essential to its interpretation. Despite this, little kinetic modelling of blood biomarkers can be found in the literature. S100b is an astrocyte related marker of brain injury used primarily in traumatic brain injury (TBI). Serum levels are expected to be the net result of a multi-compartmental process. The optimal sample times for TBI prognostication, and to follow injury development, are unclear. The purpose of this study was to develop a kinetic model to characterise the temporal course of serum S100b concentration after primary traumatic brain injury. Methods: Data of serial serum S100b samples from 154 traumatic brain injury patients in a neurointensive care unit were retrospectively analysed, including only patients without secondary peaks of this biomarker. Additionally, extra-cranial S100b can confound samples earlier than 12 h after trauma and were therefore excluded. A hierarchical, Bayesian gamma variate kinetic model was constructed and the parameters estimated by Markov chain Monte Carlo sampling. Results: We demonstrated that S100b concentration changes dramatically over timescales that are clinically important for early prognostication with a peak at 27.2 h (95 % credible interval [25.6, 28.8]). Baseline S100b levels was found to be 0.11 mu g/L (95 % credible interval [0.10, 0.12]). Conclusions: Even small differences in injury to sample time may lead to marked changes in S100b during the first days after injury. This must be taken into account in interpretation. The model offers a way to predict the peak and trajectory of S100b from 12 h post trauma in TBI patients, and to identify deviations from this, possibly indicating a secondary event. Kinetic modelling, providing an equation for the peak and projection, may offer a way to reduce the ambiguity in interpretation of, in time, randomly sampled acute biomarkers and may be generally applicable to biomarkers with, in time, well defined hits.

  • 216.
    Erdman, William A.
    et al.
    MIDDLESEX GEN UNIV HOSP,RUTGERS MED SCH,NEW BRUNSWICK,NJ 08901 .
    Maguire Jr., Gerald Q.
    Columbia University, Department of Computer Science.
    Noz, Marilyn E.
    New York University.
    Stahl, T. J.
    MIDDLESEX GEN UNIV HOSP,RUTGERS MED SCH,NEW BRUNSWICK,NJ 08901 .
    A Picture Archiving and Communication System - Modus Operandi for a Filmless Nuclear Medicine Department1986In: Administrative Radiology, ISSN 0738-6974, Vol. 5, no 1, p. 34-38Article in journal (Refereed)
  • 217.
    Erdman, William A.
    et al.
    MIDDLESEX GEN UNIV HOSP,RUTGERS MED SCH,NEW BRUNSWICK,NJ 08901 .
    Stahl, T. J.
    MIDDLESEX GEN UNIV HOSP,RUTGERS MED SCH,NEW BRUNSWICK,NJ 08901 .
    Tokarz, R. J.
    MIDDLESEX GEN UNIV HOSP,RUTGERS MED SCH,NEW BRUNSWICK,NJ 08901 .
    Maguire Jr., Gerald Q.
    Columbia University, Department of Computer Science.
    Noz, Marilyn E.
    New York University.
    Development of a Digital Nuclear-Medicine System1983In: Proceedings of the Society of Photo-Optical Instrumentation Engineers, ISSN 0361-0748, Vol. 418, p. 100-102Article in journal (Refereed)
  • 218. Erhart, P.
    et al.
    Hyhlik-Dürr, A.
    Geisbüsch, P.
    Kotelis, D.
    Müller-Eschner, M.
    Gasser, Thomas Christian
    KTH, School of Engineering Sciences (SCI), Solid Mechanics (Dept.).
    von Tengg-Kobligk, H.
    Böckler, D.
    Finite Element Analysis in Asymptomatic, Symptomatic, and Ruptured Abdominal Aortic Aneurysms: In Search of New Rupture Risk Predictors2015In: European Journal of Vascular and Endovascular Surgery, ISSN 1078-5884, E-ISSN 1532-2165, Vol. 49, no 3, p. 239-245Article in journal (Refereed)
    Abstract [en]

    Objectives: To compare biomechanical rupture risk parameters of asymptomatic, symptomatic and ruptured abdominal aortic aneurysms (AAA) using finite element analysis (FEA). Study design: Retrospective biomechanical single center analysis of asymptomatic, symptomatic, and ruptured AAAs. Comparison of biomechanical parameters from FEA. Materials and methods: From 2011 to 2013 computed tomography angiography (CTA) data from 30 asymptomatic, 15 symptomatic, and 15 ruptured AAAs were collected consecutively. FEA was performed according to the successive steps of AAA vessel reconstruction, segmentation and finite element computation. Biomechanical parameters Peak Wall Rupture Risk Index (PWRI), Peak Wall Stress (PWS), and Rupture Risk Equivalent Diameter (RRED) were compared among the three subgroups. Results: PWRI differentiated between asymptomatic and symptomatic AAAs (p < .0004) better than PWS (p < .1453). PWRI-dependent RRED was higher in the symptomatic subgroup compared with the asymptomatic subgroup (p < .0004). Maximum AAA external diameters were comparable between the two groups (p < .1355). Ruptured AAAs showed the highest values for external diameter, total intraluminal thrombus volume, PWS, RRED, and PWRI compared with asymptomatic and symptomatic AAAs. In contrast with symptomatic and ruptured AAAs, none of the asymptomatic patients had a PWRI value >1.0. This threshold value might identify patients at imminent risk of rupture: Conclusions: From different FEA derived parameter, PWRI distinguishes most precisely between asymptomatic and symptomatic AAAs. If elevated, this value may represent a negative prognostic factor for asymptomatic AAAs.

  • 219.
    Ericson, Anne
    et al.
    Karolinska Institute, Department of Molecular Medicine and Surgery, Section of Orthopaedics and Sports Medicine.
    Arndt, Anton
    Karolinska Institut, Department of Clinical Science, Intervention and Technology, Section of Orthopaedics.
    Stark, Andreas
    Karolinska Institute, Department of Molecular Medicine and Surgery.
    Noz, Marilyn E.
    New York University, Department of Radiology.
    Maguire Jr., Gerald Q.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Zeleznik, Michael P.
    Saya Systems Inc., Salt Lake City, UT, USA.
    Olivecrona, Henrik
    Karolinska Institute, Department of Molecular Medicine and Surgery.
    Fusion of radio stereometric analysis data into computed tomography space: Application to the elbow joint2007In: Journal of Biomechanics, ISSN 0021-9290, E-ISSN 1873-2380, Vol. 40, no 2, p. 296-304Article in journal (Refereed)
    Abstract [en]

    Improvement of joint prostheses is dependent upon information concerning the biomechanical properties of the joint. Radiostereometric analysis (RSA) and electromagnetic techniques have been applied in previous cadaver and in vivo studies on the elbow joint to provide valuable information concerning joint motion axes. However, such information is limited to mathematically calculated positions of the axes according to an orthogonal coordinate system and is difficult to relate to individual skeletal anatomy. The aim of this study was to evaluate the in vivo application of a new fusion method to provide three-dimensional (31)) visualization of flexion axes according to bony landmarks. In vivo RSA data of the elbow joint's flexion axes was combined with data obtained by 3D computed tomography (CT). Results were obtained from five healthy subjects after one was excluded due to an instable RSA marker. The median error between imported and transformed RSA marker coordinates and those obtained in the CT volume was 0.22mm. Median maximal rotation error after transformation of the rigid RSA body to the CT volume was 0.003 degrees. Points of interception with a plane calculated in the RSA orthogonal coordinate system were imported into the CT volume, facilitating the 3D visualization of the flexion axes. This study demonstrates a successful fusion of RSA and CT data, without significant loss of RSA accuracy. The method could be used for relating individual motion axes to a 3D representation of relevant joint anatomy, thus providing important information for clinical applications such as the development of joint prostheses.

  • 220.
    Eriksson, Bjorn
    et al.
    Karolinska Inst, Div Family Med & Primary Care, Dept Neurobiol Care Sci & Soc NVS, Huddinge, Sweden..
    Wandell, Per
    Karolinska Inst, Div Family Med & Primary Care, Dept Neurobiol Care Sci & Soc NVS, Huddinge, Sweden..
    Dahlstrom, Ulf
    Linkoping Univ, Dept Cardiol, Linkoping, Sweden.;Linkoping Univ, Dept Med & Hlth Sci, Linkoping, Sweden..
    Näsman, Per
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management, Building and Real Estate Economics.
    Lund, Lars H.
    Karolinska Inst, Karolinska Univ Hosp, Dept Cardiol, Div Med, Stockholm, Sweden..
    Edner, Magnus
    Karolinska Inst, Div Family Med & Primary Care, Dept Neurobiol Care Sci & Soc NVS, Huddinge, Sweden..
    Limited value of NT-proBNP as a prognostic marker of all-cause mortality in patients with heart failure with preserved and mid-range ejection fraction in primary care: A report from the swedish heart failure register2019In: Scandinavian Journal of Primary Health Care, ISSN 0281-3432, E-ISSN 1502-7724, Vol. 37, no 4, p. 434-443Article in journal (Refereed)
    Abstract [en]

    Aim: The prognostic value of natriuretic peptides in the management of heart failure (HF) patients with ejection fraction (EF) <40% is well established, but is less known for those with EF >= 40% managed in primary care (PC). Therefore, the aim of this study is to describe the prognostic significance of plasma NT-proBNP in such patients managed in PC. Subjects: We included 924 HF patients (48% women) with EF >= 40% and NT-proBNP registered in the Swedish Heart Failure Registry. Follow-up was 1100 +/- 687 days. Results: One-, three- and five-year mortality rates were 8.1%, 23.9% and 44.7% in patients with EF 40-50% (HFmrEF) and 7.3%, 23.6% and 37.2% in patients with EF >= 50% (HFpEF) (p = 0.26). Patients with the highest mean values of NT-proBNP had the highest all-cause mortality but wide standard deviations (SDs). In univariate regression analysis, there was an association only between NT-proBNP quartiles and all-cause mortality. In HFmrEF patients, hazard ratio (HR) was 1.96 (95% CI 1.60-2.39) p < 0.0001) and in HFpEF patients, HR was 1.72 (95% CI 1.49-1.98) p < 0.0001). In a multivariate Cox proportional hazard regression analysis, adjusted for age, NYHA class, atrial fibrillation and GFR class, this association remained regarding NT-proBNP quartiles [HR 1.83 (95% CI 1.38-2.44), p < 0.0001] and [HR 1.48 (95% CI 1.16-1.90), p = 0.0001], HFmrEF and HFpEF, respectively. Conclusion: NT-proBNP has a prognostic value in patients with HF and EF >= 40% managed in PC. However, its clinical utility is limited due to high SDs and the fact that it is not independent in this population which is characterized by high age and much comorbidity.

  • 221. Eriksson, Hanna
    et al.
    Thrane, Kim
    Maaskola, Jonas
    Hansson, Johan
    Lundeberg, Joakim
    KTH, School of Biotechnology (BIO), Gene Technology.
    Dissecting genetic heterogeneity in stage III cutaneous malignant melanoma with spatially resolved transcriptomics.2018In: Journal of Clinical Oncology, ISSN 0732-183X, E-ISSN 1527-7755, Vol. 36, no 15Article in journal (Other academic)
  • 222.
    Eriksson, Marie
    et al.
    Karolinska Institutet, Dept. of Women's and Children's Health.
    Gutierrez-Farewik, Elena
    KTH, School of Engineering Sciences (SCI), Mechanics, Structural Mechanics. Karolinska Institutet.
    Broström, Eva
    Karolinska Institutet, Dept. of Women's and Children's Health.
    Bartonek, Åsa
    Karolinska Institutet, Dept. of Women's and Child's Health.
    Gait pattern in children with arthrogryposis multiplex congenita2010In: Journal of Children's Orthopaedics, ISSN 1863-2521, E-ISSN 1863-2548, Vol. 4, no 1, p. 21-31Article in journal (Refereed)
    Abstract [en]

    Purpose: Lower limb contractures and muscle weakness are common in children with arthrogryposis multiplex congenita (AMC). To enhance or facilitate ambulation, orthoses may be used. The aim of this study was to describe gait pattern among individuals wearing their habitual orthotic devices. Methods: Fifteen children with AMC, mean age 12. 4 (4. 3) years, with some lower limb involvement underwent 3-D gait analysis. Three groups were defined based on orthosis use; Group 1 used knee-ankle-foot orthoses with locked knee joints, Group 2 used ankle-foot orthoses or knee-ankle-foot orthoses with open knee joints and Group 3 used no orthoses. Results: The greatest trunk and pelvis movements in all planes and the greatest hip abduction were observed in Group 1, compared to Groups 2 and 3, as well as to the gait laboratory control group. Maximum hip extension was similar in Groups 1 and 2, but in Group 3, there was less hip extension and large deviations from the control data. Lower cadence and walking speed were observed in Group 1 than in Groups 2 and 3. The step length was similar in all groups and also with respect to the gait laboratory reference values. Conclusions: Children with AMC were subdivided according to orthoses use. Kinematic data as recorded with 3-D gait analysis showed differences among the groups in trunk, pelvis and knee kinematics, and in cadence and walking speed. The step length was similar in all groups and to the gait laboratory reference values, which may be attributable to good hip extension strength in all participants.

  • 223.
    Eriksson, Thomas
    et al.
    Department of Radiology, Centre for Medical Imaging, Uppsala University Hospital, Uppsala, Sweden.
    Maguire Jr., Gerald Q.
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Noz, Marilyn E.
    New York University, Department of Radiology.
    Zeleznik, Michael P.
    University of Utah.
    Olivecrona, Henrik
    Karolinska Institutet, Sweden.
    Shalabi, Adel
    Department of Radiology, Centre for Medical Imaging, Uppsala University Hospital, Uppsala, Sweden.
    Hänni, Mari
    Department of Radiology, Centre for Medical Imaging, Uppsala University Hospital, Uppsala, Sweden.
    Are low-dose CT scans a satisfactory substitute for stereoradiographs for migration studies? A preclinical test of low-dose CT scanning protocols and their application in a pilot patient.2019In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, article id 284185119844166Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Computed tomography (CT) has the potential to acquire the data needed for migration studies of orthopedic joint implants of patients who have had tantalum beads implanted at the time of joint replacement surgery. This can be accomplished with the same precision as radiostereometric analysis (RSA). Switching to CT would increase availability without the need for the specific facilities required for RSA. However, higher effective dose is a concern.

    PURPOSE: To investigate if migration measurements can be done with CT with an accuracy and effective dose comparable to that of conventional RSA.

    MATERIAL AND METHODS: Fourteen scanning protocols were tested in a hip phantom that incorporated tantalum beads and an uncemented femoral stem. The protocols were graded for clinical practice according to the three parameters of image quality, effective dose, and robustness of numerical data. After grading, the two protocols that graded best overall were applied to a pilot patient.

    RESULTS: All protocols produced scans in which the numerical data were sufficient for a migration analysis at least as precise as would be expected using RSA. A protocol with an effective dose of 0.70 mSv was shown to be applicable in a pilot patient.

    CONCLUSION: Low-dose CT scans with an effective dose comparable to a set of routine plain radiographs can be used for precise migration measurements.

  • 224. Eriksson, Y.
    et al.
    Gärdenfors, Dan
    KTH, School of Industrial Engineering and Management (ITM), Centres, Stockholm International Toy Research Center, SITREC.
    Computer games for children with visual impairments2005In: Journal of Endocrine Genetics, ISSN 1565-012X, Vol. 4, no 3, p. 161-167Article in journal (Refereed)
    Abstract [en]

    The Swedish Library of Talking Books and Braille (TPB) published web-based computer games for children with different kinds of visual impairments. As the target groups have very different needs, when it comes to the use of graphics and sound, TPB have developed two kinds of games. Image-based games aim to encourage children with partial sight to practice recognizing visual objects, whereas sound-based games also intend to be accessible without relying on vision. Based on the results of two pilot studies, this paper discusses central design issues of the graphical and sound-based interfaces for this type of application.

  • 225.
    Etcheverry, Sebastian
    et al.
    KTH, School of Engineering Sciences (SCI), Applied Physics, Laser Physics.
    Faridi, Asim
    KTH, School of Biotechnology (BIO), Proteomics and Nanobiotechnology.
    Ramachandraiah, Harisha
    KTH, School of Biotechnology (BIO), Proteomics and Nanobiotechnology.
    Kumar, Tharagan
    KTH, School of Biotechnology (BIO), Proteomics and Nanobiotechnology.
    Margulis, Walter
    KTH, School of Engineering Sciences (SCI), Applied Physics, Laser Physics.
    Laurell, Fredrik
    KTH, School of Engineering Sciences (SCI), Applied Physics, Laser Physics.
    Russom, Aman
    KTH, School of Biotechnology (BIO), Proteomics and Nanobiotechnology.
    All silica fibre microflow cytometerManuscript (preprint) (Other academic)
    Abstract [en]

    Flow cytometry is currently the gold standard for analysis of cells in the medical laboratory and biomedical research. Fuelled by the need of point-of-care diagnosis, a significant effort has been made to miniaturize and reduce cost of flow cytometers. However, despite recent advances, current microsystems remain less versatile and much slower than their large-scale counterparts. In this work, an all-silica fibre microflow cytometer is presented that measures fluorescence and scattering from particles and cells. It integrates cell transport in circular capillaries and light delivery by optical fibres   Single-stream cell focusing is performed by Elasto-inertial microfluidics to guarantee optical accuracy and sensitivity.  The capability of this technique is extended to high flow rates (up to 800 µl/min), enabling throughput of 2500 particles/s. The robust, portable and low-cost system described here could be the basis for a point-of-care flow cytometer with a performance comparable to commercial systems. 

    Download full text (pdf)
    fulltext
  • 226.
    Etcheverry, Sebastian
    et al.
    KTH, School of Engineering Sciences (SCI), Applied Physics. Acreo Swedish ICT AB, Sweden.
    Sudirman, Aziza
    KTH, School of Engineering Sciences (SCI), Applied Physics. Acreo Swedish ICT AB, Sweden.
    Margulis, Walter
    KTH, School of Engineering Sciences (SCI), Applied Physics. Acreo Swedish ICT AB, Sweden.
    Laurell, Fredrik
    KTH, School of Engineering Sciences (SCI), Applied Physics, Laser Physics.
    Identification and collection of particles with optical fibers2015In: NOVEL BIOPHOTONICS TECHNIQUES AND APPLICATIONS III, 2015, Vol. 9540, article id 95400NConference paper (Refereed)
    Abstract [en]

    A micro-structured fiber-based system for identification and collection of fluorescent particles is demonstrated. An optical fiber probe with longitudinal holes in the cladding is used to retrieve fluorescent particles by exerting microfluidics forces. Laser induced fluorescent (LIF) is carried out by the fiber probe and an optical setup. When a particle with a previously chosen fluorescence wavelength is identified, a vacuum pump is activated collecting the particle into a hole. Green and red fluorescent polystyrene particles were detected and selectively retrieved.

  • 227. Falk, Ingrid Jakobsen
    et al.
    Fyrberg, Anna
    Paul, Esbjörn
    Nahi, Hareth
    Hermanson, Monica
    Rosenquist, Richard
    Höglund, Martin
    Palmqvist, Lars
    Stockelberg, Dick
    Wei, Yuan
    Gréen, Henrik
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Lotfi, Kourosh
    Decreased survival in normal karyotype AML with single-nucleotide polymorphisms in genes encoding the AraC metabolizing enzymes cytidine deaminase and 5 '-nucleotidase2013In: American Journal of Hematology, ISSN 0361-8609, E-ISSN 1096-8652, Vol. 88, no 12, p. 1001-1006Article in journal (Refereed)
    Abstract [en]

    De novo acute myeloid leukemia with normal karyotype (NK-AML) comprises a large group of patients with no common cytogenetic alterations and with a large variation in treatment response. Single-nucleotide polymorphisms (SNPs) in genes related to the metabolism of the nucleoside analogue AraC, the backbone in AML treatment, might affect drug sensitivity and treatment outcome. Therefore, SNPs may serve as prognostic biomarkers aiding clinicians in individualized treatment decisions, with the aim of improving patient outcomes. We analyzed polymorphisms in genes encoding cytidine deaminase (CDA 79A> C rs2072671 and 2451C> T rs532545), 50-nucleotidase (cN-II 7A> G rs10883841), and deoxycytidine kinase (DCK 30UTR 948T> C rs4643786) in 205 de novo NK-AML patients. In FLT3-internal tandem duplication (ITD)-positive patients, the CDA 79C/C and 2451T/T genotypes were associated with shorter overall survival compared to other genotypes (5 vs. 24 months, P< 0.001 and 5 vs. 23 months, P50.015, respectively), and this was most pronounced in FLT3-ITD-positive/NPM1-positive patients. We observed altered in vitro sensitivity to topoisomerase inhibitory drugs, but not to nucleoside analogues, and a decrease in global DNA methylation in cells carrying both CDA variant alleles. A shorter survival was also observed for the cN-II variant allele, but only in FLT3-ITD-negative patients (25 vs. 31 months, P50.075). Our results indicate that polymorphisms in genes related to nucleoside analog drug metabolism may serve as prognostic markers in de novo NK-AML.

  • 228. Falkenius, J
    et al.
    Lindberg, J
    Johansson, H.
    Frostvik-Stolt, M.
    Lundeberg, Joakim
    KTH, School of Biotechnology (BIO), Gene Technology.
    Hansson, J.
    Egyhazi, S.
    A gene expression profile associated with clinical outcome in stage III melanoma2011In: Journal of Clinical Oncology, ISSN 0732-183X, E-ISSN 1527-7755, Vol. 29, no 15Article in journal (Other academic)
  • 229.
    Fang, Yuan
    et al.
    US FDA, Div Radiol Hlth, Off In Vitro Diagnost & Radiol Hlth, Ctr Devices & Radiol Hlth, 10903 New Hampshire Ave, Silver Spring, MD 20993 USA..
    Xu, Cheng
    KTH, School of Engineering Sciences (SCI), Physics, Physics of Medical Imaging.
    Yao, Yuan
    Stanford Univ, Dept Bioengn, Stanford, CA 94305 USA.;Stanford Univ, Dept Radiol, Stanford, CA 94305 USA..
    Pelc, Norbert
    Stanford Univ, Dept Bioengn, Stanford, CA 94305 USA.;Stanford Univ, Dept Radiol, Stanford, CA 94305 USA.;Stanford Univ, Dept Elect Engn, Stanford, CA 94305 USA..
    Danielsson, Mats
    KTH, School of Engineering Sciences (SCI), Physics, Physics of Medical Imaging.
    Badano, Aldo
    US FDA, Div Imaging Diagnost & Software Reliabil, Off Sci & Engn Labs, Ctr Devices & Radiol Hlth, 10903 New Hampshire Ave, Silver Spring, MD 20993 USA..
    Modeling charge transport in photon-counting detectors2018In: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, ISSN 0168-9002, E-ISSN 1872-9576, Vol. 899, p. 115-121Article in journal (Refereed)
    Abstract [en]

    The purpose of this study is to review and compare simulation methods for describing the transport of charge clouds in silicon based semiconductor detectors and investigate the effects on energy spectrum for silicon based photon-counting strip detectors. Charge clouds and detailed carrier transport are simulated and compared using two different approaches including analytical and Monte Carlo schema. The results of the simulations are evaluated using pulse-height spectra (PHS) for a silicon strip detector with edge on geometry at two energies (25 and 75 keV) at various X-ray absorption locations relative to the pixel boundary and detector depth. The findings confirm carrier diffusion plays a large role in the charge sharing effect in photon counting detectors, in particular when the photon is absorbed near the pixel boundary far away from the pixel electrode. The results are further compared in terms of the double-counting probability for X-ray photons absorbed near the pixel boundary as a function of the threshold energy. Monte Carlo and analytical models show reasonable agreement (2% relative error in swank factor) for charge sharing effects for a silicon strip detector with edge-on geometry. For 25 keV mono-energetic photons absorbed at 5 mu m from the pixel boundary, the theoretical threshold energy at 10% double-counting probability based on charge sharing is 5.5, 8.5 and 9.2 keV for absorption depths of 50, 250 and 450 mu m from the electrode, respectively. The transport of charge clouds affects the spectral characteristics of photon counting detectors and the double-counting probability results show the theoretical threshold energy to avoid double-counting as a function of X-ray energy and X-ray interaction locations for silicon and can be considered for future studies of charge sharing effects.

  • 230.
    Farewik, Lanie
    KTH, School of Engineering Sciences (SCI), Mechanics, Biomechanics. University of Michigan, Department of Mechanical Engineering, Division of Biomechanics.
    Mild diabetic neuropathy affects ankle motor function2001In: Clinical Biomechanics, ISSN 0268-0033, E-ISSN 1879-1271, Vol. 16, no 6, p. 522-528Article in journal (Refereed)
    Abstract [en]

    Objective. To evaluate the effect of age and diabetic neuropathy on ankle motor function in the frontal plane in terms of rate of torque development and capability for balance recovery.

    Design. Case control study. Six older women with diabetic neuropathy compared to six women without neuropathy, matched for age and presence of diabetes mellitus; and nine healthy young women.

    Background. Neuropathy causes a distal impairment in lower extremity sensory function which increases fall risk. Impairments in ankle inversion/eversion proprioceptive thresholds have been identified, but the effect of neuropathy on ankle motor strength in the frontal plane is unknown.

    Methods. Subjects' abilities to recover from a lateral lean (with center of gravity offset as percentage of foot width) while standing on one foot, and to rapidly generate inversion torque about the ankle, were quantified.

    Results. All nine of the young, but only one of six older, control subjects recovered from a 10% lean (P=0.0052). Three of six older controls, but no neuropathy subject, recovered from a 5% lean (P=0.083). Neuropathy subjects demonstrated half the ankle rate of torque development [78.2 (50.8) N m/s; P=0.016] of the young and older controls [162.0 (54.6) and 152.7 (22.2) N m/s, respectively].

    Conclusions. Diabetic neuropathy leads to a decrease in rapidly available ankle strength which impairs balance recovery among older women. Younger women demonstrate similar ankle strength but superior balance recovery compared to older women without neuropathy.Relevance

    Older women with diabetic neuropathy and normal ankle strength, as judged by clinical muscle testing, demonstrate a sub-clinical impairment in ankle motor function suggesting a target for intervention.

  • 231.
    Farrell, Edward J.
    et al.
    IBM Research.
    Gorniak, Richard J.
    New York University.
    Kramer, Elissa L.
    New York University.
    Noz, Marilyn E.
    New York University.
    Maguire Jr., Gerald Q.
    KTH, Superseded Departments, Teleinformatics.
    Reddy, David P.
    Graphical 3D medical image registration and quantification1997In: Journal of medical systems, ISSN 0148-5598, E-ISSN 1573-689X, Vol. 21, no 3, p. 155-172Article in journal (Refereed)
    Abstract [en]

    We present a graphical three-dimensional method that facilitates image registration and fusion, and provides quantitative geometric and volume information. In particular it enhances the use of functional (radiopharmaceutical) imaging {(SPECT}, {PET)} which, though a powerful clinical tool, has the disadvantage of low spatial resolution and ill-defined boundaries. Registration between functional images and structural images {(MRI}, {CT)} can augment the anatomical context of these functional images.

  • 232.
    Farrell, Edward J.
    et al.
    IBM Thomas J. Watson Research Center.
    Kramer, Elissa L.
    New York University.
    Noz, Marilyn E.
    New York University.
    Maguire Jr., Gerald Q.
    KTH, Superseded Departments, Teleinformatics.
    Quantitative 3D visualization in nuclear medicine1995In: Proceedings of the SPIE Medical Imaging 1995, SPIE - International Society for Optical Engineering, 1995, Vol. 2431, p. 54-64Conference paper (Refereed)
    Abstract [en]

    SPECT is a powerful clinical tool. However, the low spatial resolution and ill-defined boundaries associated with SPECT require special consideration in visualization. Quantitative geometric and magnitude information are areas of particular usefulness in evaluating disease states. In this paper, we describe a set of practical 3D visualization tools to display and analyze SPECT data, and present interactive methods to measure (1) the relative position, size and shape of regions of interest and (2) the magnitude and distribution of radioactive count information. Interactive pick tools allow users to extract values at selected points, distance between points, or value profiles along selected line segments. In the three-dimensional reconstruction, transparent and opaque isosurfaces are formed simultaneously at specified activity levels, and the volume enclosed by the opaque surface is displayed. The utility of these tools is demonstrated with two types of patient studies: those using tumor-avid agents to identify active tumor in the chest and abdomen, and those used for evaluating the volume of perfused myocardium.

  • 233.
    Fatemi, Alimohammad
    et al.
    Isfahan Univ Med Sci, Sch Med, Dept Internal Med, Rheumatol Sect, Esfahan, Iran..
    Erlandsson, Björn-Erik
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems.
    Emrani, Zahra
    Isfahan Univ Med Sci, Sch Med, Dept Med Phys, Esfahan, Iran..
    Etehadtavakol, Mahnaz
    Isfahan Univ Med Sci, Sch Med, Dept Med Phys, Esfahan, Iran..
    Smiley, Abbas
    Indiana Univ, Sch Publ Hlth, Dept Epidemiol & Biostat, Bloomington, IN USA..
    Karbalaie, Abdolamir
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems.
    Nailfold microvascular changes in patients with systemic lupus erythematosus and their associative factors2019In: Microvascular Research, ISSN 0026-2862, E-ISSN 1095-9319, Vol. 126, article id UNSP 103910Article in journal (Refereed)
    Abstract [en]

    Objectives: The aim of this study was to determine capillaroscopic changes in patients with systemic lupus erythematosus (SLE) and their predictors. Methods: Fifty-nine SLE patients and 31 controls were enrolled in a cross-sectional study. Nailfold capillaroscopy examinations were performed, and qualitative semi-quantitative and quantitative parameters were evaluated in all fingers. Demographic features and lupus characteristics, such as renal involvement, medications, laboratory data, disease activity (SLEDAI) and damage, were recorded. The predictors of capillaroscopic abnormalities were obtained by backward stepwise regression analysis. Results: Capillary numbers of right hands were significantly lower in patients than in controls [8.74 (1.66) vs. 9.63 (1.80), P = 0.0001]. Capillaries were wider in patients than in controls in right [56.32 pm (16.76) vs. 50.43 mu m (10.16), P = 0.002] and left hands [54.40 (15.02) vs. 49.71 (9.77), P = 0.005]. Capillaries were shorter in SLE patients than in controls. Multivariate analysis revealed that the main associative factors of microvascular abnormalities were gender, drinking tea and hydroxychloroquine use for giant capillaries, SLEDAI and low C3 for avascularity and age, lupus nephritis and corticosteroid use for ramification. Conclusion: Most nailfold capillaroscopic abnormalities were more common in SLE patients than in controls. Hydroxychloroquine, corticosteroids, SLEDAI, low complement and lupus nephritis may be the major prognostic factors for microvascular changes in SLE patients.

  • 234.
    Felices, Martin
    et al.
    Univ Minnesota, Dept Med, Div Hematol Oncol & Transplantat, Box 736 UMHC, Minneapolis, MN 55455 USA..
    Sarhan, Dhifaf
    Univ Minnesota, Dept Med, Div Hematol Oncol & Transplantat, Box 736 UMHC, Minneapolis, MN 55455 USA.;Karolinska Inst, Dept Oncol Pathol, Stockholm, Sweden..
    Brandt, Ludwig
    KTH, School of Engineering Sciences (SCI), Applied Physics. KTH, Centres, Science for Life Laboratory, SciLifeLab. KTH Royal Inst Technol, Dept Appl Phys, Sci Life Lab, Stockholm, Sweden..
    Guldevall, Karolin
    KTH, School of Engineering Sciences (SCI), Applied Physics. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    McElmurry, Ron
    Univ Minnesota, Dept Med, Div Hematol Oncol & Transplantat, Box 736 UMHC, Minneapolis, MN 55455 USA..
    Lenvik, Alexander
    Univ Minnesota, Dept Med, Div Hematol Oncol & Transplantat, Box 736 UMHC, Minneapolis, MN 55455 USA..
    Chu, Sami
    Univ Minnesota, Dept Med, Div Hematol Oncol & Transplantat, Box 736 UMHC, Minneapolis, MN 55455 USA..
    Tolar, Jakub
    Univ Minnesota, Dept Pediat, Div Blood & Marrow Transplantat, Minneapolis, MN 55455 USA.;Univ Minnesota, Stem Cell Inst, Minneapolis, MN USA..
    Taras, Elizabeth
    Univ Minnesota, Dept Therapeut Radiol Radiat Oncol, Lab Mol Canc Therapeut, Masonic Canc Ctr, Minneapolis, MN USA..
    Spellman, Stephen R.
    Natl Marrow Donor Program, Minneapolis, MN USA..
    Warlick, Erica D.
    Univ Minnesota, Hematol Oncol & Transplantat, Minneapolis, MN USA..
    Verneris, Michael R.
    Univ Minnesota, Dept Pediat, Div Pediat Hematol Oncol Bone & Marrow Transplant, Minneapolis, MN 55455 USA..
    Cooley, Sarah
    Univ Minnesota, Dept Med, Div Hematol Oncol & Transplantat, Box 736 UMHC, Minneapolis, MN 55455 USA..
    Weisdorf, Daniel
    Univ Minnesota, Hematol Oncol & Transplantat, Minneapolis, MN USA..
    Blazar, Bruce R.
    Univ Minnesota, Dept Pediat, Blood & Marrow Transplantat, Minneapolis, MN 55455 USA..
    Önfelt, Björn
    KTH, School of Engineering Sciences (SCI), Applied Physics. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Vallera, Dan
    Univ Minnesota, Dept Therapeut Radiol Radiat Oncol, Masonic Canc Ctr, Minneapolis, MN USA..
    Miller, Jeffrey S.
    Univ Minnesota, Hematol Oncol & Transplantat, Minneapolis, MN USA..
    CD16-IL15-CD33 Trispecific Killer Engager (TriKE) Overcomes Cancer-Induced Immune Suppression and Induces Natural Killer Cell-Mediated Control of MDS and AML Via Enhanced Killing Kinetics2016In: Blood, ISSN 0006-4971, E-ISSN 1528-0020, Vol. 128, no 22Article in journal (Other academic)
  • 235.
    Ferrannini, Giulia
    et al.
    Karolinska Inst, Dept Med, Cardiol Unit, Stockholm, Sweden.;Univ Turin, Postgrad Sch Internal Med, Dept Med Sci, Turin, Italy..
    Svenungsson, Elisabet
    Karolinska Inst, Karolinska Univ Hosp, Dept Med Solna, Rheumatol Unit, Stockholm, Sweden..
    Kjellstrom, Barbro
    Karolinska Inst, Dept Med, Cardiol Unit, Stockholm, Sweden..
    Elvin, Kerstin
    Karolinska Inst, Dept Clin Immunol & Transfus Med, Unit Clin Immunol, Stockholm, Sweden..
    Grosso, Giorgia
    Karolinska Inst, Karolinska Univ Hosp, Dept Med Solna, Rheumatol Unit, Stockholm, Sweden..
    Näsman, Per
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management, Building and Real Estate Economics.
    Ryden, Lars
    Karolinska Inst, Dept Med, Cardiol Unit, Stockholm, Sweden..
    Norhammar, Anna
    Karolinska Inst, Dept Med, Cardiol Unit, Stockholm, Sweden.;Capio St Gorans Hosp, Stockholm, Sweden..
    Dysglycaemic patients with antiphospholipid antibodies IgG: a neglected group at high cardiovascular risk?2019In: Lupus, ISSN 0961-2033, E-ISSN 1477-0962, Vol. 28, p. 42-42Article in journal (Other academic)
  • 236. Ferrari, A.
    et al.
    Fiorino, E.
    Longo, R.
    Barilla, S.
    Mitro, N.
    Cermenati, G.
    Giudici, Marco
    KTH, School of Biotechnology (BIO), Proteomics and Nanobiotechnology.
    Caruso, D.
    Mai, A.
    Guerrini, U.
    De Fabiani, E.
    Crestani, M.
    Attenuation of diet-induced obesity and induction of white fat browning with a chemical inhibitor of histone deacetylases2017In: International Journal of Obesity, ISSN 0307-0565, E-ISSN 1476-5497, Vol. 41, no 2, p. 289-298Article in journal (Refereed)
    Abstract [en]

    BACKGROUND/OBJECTIVES: In the last decade, a strict link between epigenetics and metabolism has been demonstrated. Histone deacetylases (HDACs) have emerged as key epigenetic regulators involved in metabolic homeostasis in normal and pathologic conditions. Here we investigated the effect of the class I HDAC inhibitor MS-275 in a model of obesity induced by a high-fat diet (HFD). METHODS: C57BL6/J male mice were fed HFD for 17 weeks and then randomized in two groups, treated intraperitoneally with vehicle dimethylsulfoxide (DMSO) or with the class I selective HDAC inhibitor MS-275 every other day for 22 days. Glucose tolerance test and measurement of body temperature during cold exposure were performed. Adipose tissues and liver were phenotypically characterized through histological analysis. Gene and protein expression analysis of brown and white adipose tissues (WATs) were performed. RESULTS: MS-275 treated mice showed 10% reduction of body weight, lower adipocyte size and improved glucose tolerance. Inhibition of class I HDAC determined reduction of adipocyte size and of fat mass, paralleled by higher expression of adipose functionality markers and by increased rate of lipolysis and fatty acid beta-oxidation. MS-275 also promoted thermogenic capacity, related to `browning' of visceral and subcutaneous WAT, showing increased expression of uncoupling protein 1. In brown adipose tissue, we observed limited effects on gene expression and only reduction of brown adipocyte size. CONCLUSIONS: This study provides evidence that class I HDAC inhibition stimulated functionality and oxidative potential of adipose tissue, improving glucose tolerance and ameliorating the metabolic profile in diet-induced obese mice.

  • 237.
    Fiebig, Florian
    et al.
    KTH, School of Computer Science and Communication (CSC), Computational Biology, CB.
    Lansner, Anders
    KTH, School of Computer Science and Communication (CSC), Computational Biology, CB.
    Memory consolidation from seconds to weeks: a three-stage neural network model with autonomous reinstatement dynamics2014In: Frontiers in Computational Neuroscience, ISSN 1662-5188, E-ISSN 1662-5188, Vol. 8, p. 64-Article in journal (Refereed)
    Abstract [en]

    Declarative long-term memories are not created in an instant. Gradual stabilization and temporally shifting dependence of acquired declarative memories in different brain regions called systems consolidation- can be tracked in time by lesion experiments. The observation of temporally graded retrograde amnesia(RA) following hippocampal lesions points to a gradual transfer of memory from hippocampus to neocortical long-term memory. Spontaneous reactivations of hippocampal memories, asobserved in place cell reactivations during slow wave- sleep, are supposed to driven eocortical reinstatements and facilitate this process. We proposea functional neural network implementation of these ideas and further more suggest anextended three-state framework that includes the prefrontal cortex( PFC). It bridges the temporal chasm between working memory percepts on the scale of seconds and consolidated long-term memory on the scale of weeks or months. Wes how that our three-stage model can autonomously produce the necessary stochastic reactivation dynamics for successful episodic memory consolidation. There sulting learning system is shown to exhibit classical memory effects seen in experimental studies, such as retrograde and anterograde amnesia(AA) after simulated hippocampal lesioning; further more the model reproduces peculiar biological findings on memory modulation, such as retrograde facilitation of memory after suppressed acquisition of new longterm memories- similar to the effects of benzodiazepines on memory.

  • 238. Figueiredo, I. N.
    et al.
    Dodangeh, M.
    Pinto, L.
    Figueiredo, P. N.
    Tsai, R.
    KTH.
    Colonic Polyp Identification Using Pareto Depth Anomaly Detection Algorithm2019In: Lecture Notes in Computational Vision and Biomechanics, Springer Netherlands , 2019, p. 3-11Conference paper (Refereed)
    Abstract [en]

    Colon cancer prevention, diagnosis, and prognosis are directly related to the identification of colonic polyps, in colonoscopy video sequences. In addition, diagnosing colon cancer in the early stages improves significantly the chance of surviving and effective treatment. Due to the large number of images that come from colonoscopy, the identification of polyps needs to be automated for effciency. In this paper, we propose a strategy for automatic polyp recognition, based on a recent multi-objective anomaly detection concept, which itself is based on Pareto Depth Analysis (PDA). Clinically, in medical images, polyps are diagnosed based on a few criteria, such as texture, shape and color. Few works use multi-criteria classification in a systematic way for polyp detection. In the present paper we use a PDA approach, to act as a binary classifier for the identification of colonic polyps. The results obtained in a medical dataset, of conventional colonoscopy images, consisting of short videos from 34 different patients, and 34 different polyps, with a total of 1360 different polyp frames, confirm that the proposed method clearly outperforms the single performance of each criterion.

  • 239. Filippov, Andrey
    et al.
    Dvinskikh, Sergey V.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Khakimov, Aidar
    Grahn, Mattias
    Zhou, Han
    Furo, Istvan
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Antzutkin, Oleg N.
    Hedlund, Jonas
    Dynamic properties of water in silicalite-1 powder2012In: Magnetic Resonance Imaging, ISSN 0730-725X, E-ISSN 1873-5894, Vol. 30, no 7, p. 1022-1031Article in journal (Refereed)
    Abstract [en]

    Self-diffusion of D2O in partially filled silicalite-1 crystals was studied at 25 degrees C by H-2 nuclear magnetic resonance (NMR) with bipolar field gradient pulses and longitudinal Eddy-current-delay. For the first time, reliable experimental diffusion data for this system were obtained. Analysis of NMR diffusion decays revealed the presence of a continuous distribution of apparent self-diffusion coefficients (SDCs) of water, ranging from 10(-7) to similar to 10(-10) m(2)/s, which include values much higher and lower than that of bulk water (similar to 10(-9) m(2)/s) in liquid phase. The observed distribution of SDC changes with variation of the diffusion time in the range of 10-200 ms. A two-site Karger exchange model was successfully fitted to the data. Finally, the water distribution and exchange in silicalite-1 pores were described by taking into account (a) a gas-like phase in the zeolite pores, a gas-like phase in mesopores and an intercrystalline gas-like phase and (b) intercrystalline liquid droplets with intermediate exchange rate with the other phases. The other phases experience fast exchange on the NMR diffusion time scale. Diffusion coefficients and mean residence times of water in some of these states were estimated.

  • 240. Flinck, M.
    et al.
    von Heideken, J.
    Janarv, P. -M
    Wåtz, Veronica
    KTH, School of Engineering Sciences (SCI), Solid Mechanics (Dept.).
    Riad, J.
    Biomechanical comparison of semi-rigid pediatric locking nail versus titanium elastic nails in a femur fracture model2015In: Journal of Children's Orthopaedics, ISSN 1863-2521, E-ISSN 1863-2548, Vol. 9, no 1, p. 77-84Article in journal (Refereed)
    Abstract [en]

    Methods: Twenty-four femur models with an intramedullary canal diameter of 10.0 mm were used. Three groups with various combinations of titanium elastic nails (TEN) with end caps and one group with a PLN were tested. An oblique midshaft fracture was created, and the models underwent compression, rotation, flexion/extension, and a varus/valgus test, with 50 and 100 % of the forces generated during walking in corresponding planes. Results: We present the results [median (range)] from 100 % loading during walking. In axial compression, the PLN was less shortened than the combination with two 4.0-mm TEN [by 4.4 (3.4–5.4) mm vs. 5.2 (4.8–6.6) mm, respectively; p = 0.030]. No difference was found in shortening between the PLN and the four 3.0-mm TEN [by 7.0 (3.3–8.4) mm; p = 0.065]. The two 3.0-mm TEN did not withstand the maximum shortening of 10.0 mm. In external rotation, the PLN rotated 12.0° (7.0–16.4°) while the TEN models displaced more than the maximum of 20.0°. No model withstood a maximal rotation of 20.0° internal rotation. In the four-point bending test, in the coronal and the sagittal plane, all combinations except the two 3.0-mm TEN in extension withstood the maximum angulation of 20.0°. Conclusions: PLN provides the greatest stability in all planes compared to TEN models with end caps, even though the difference from the two 4.0-mm or four 3.0-mm TEN models was small. Background: The treatment for length-unstable diaphyseal femur fractures among school-age children is commonly intramedullary elastic nails, with or without end caps. Another possible treatment is the semi-rigid pediatric locking nail (PLN). The purpose of this biomechanical study was to assess the stability of a length-unstable oblique midshaft fracture in a synthetic femur model stabilized with different combinations of intramedullary elastic nails and with a PLN.

  • 241.
    Flisberg, A.
    et al.
    Department of Pediatrics, Queen Silvia Children's Hospital, Sahlgrenska University Hospital, Sweden.
    Kjellmer, I.
    Department of Pediatrics, Queen Silvia Children's Hospital, Sahlgrenska University Hospital, Sweden.
    Löfhede, J.
    School of Engineering, University of Borås, Sweden.
    Lindecrantz, Kaj
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS) (Closed 20130701).
    Thordstein, M.
    Department of Clinical Neurophysiology, Institute of Neuroscience and Physiology, Sahlgrenska University Hospital, Göteborg, Sweden.
    Prognostic capacity of automated quantification of suppression time in the EEG of post-asphyctic full-term neonates2011In: Acta Paediatrica, ISSN 0803-5253, E-ISSN 1651-2227, Vol. 100, no 10, p. 1338-1343Article in journal (Refereed)
    Abstract [en]

    Aim: To evaluate the prognostic capacity of a new method for automatic quantification of the length of suppression time in the electroencephalogram (EEG) of a group of asphyxiated newborn infants. Methods: Twenty-one full-term newborn infants who had been resuscitated for severe birth asphyxia were studied. Eight channel continuous EEG was recorded for prolonged time periods during the first days of life. Artefact detection or rejection was not applied to the signals. The signals were fed through a pretrained classifier and then segmented into burst and suppression periods. Total suppression length per hour was calculated. All surviving patients were followed with structured neurodevelopmental assessments to at least 18 months of age. Results: The patients who developed neurodevelopmental disability or died had significant suppression periods in their EEG during the first days of life while the patients who had a normal follow-up had no or negligible amount of suppression. Conclusions: This new method for automatic quantification of suppression periods in the raw, neonatal EEG discriminates infants with good from those with poor outcome.

  • 242.
    Flisberg, A.
    et al.
    Department of Pediatrics, Queen Silvia Children's Hospital, Sahlgrenska University Hospital-Östra.
    Kjellmer, I.
    Department of Pediatrics, Queen Silvia Children's Hospital, Sahlgrenska University Hospital-Östra.
    Löfhede, J.
    School of Engineering, University of Borås.
    Löfgren, N.
    Neoventa Medical AB, Göteborg.
    Rosa-Zurera, M.
    Department of Signal Theory and Communications, University of Alcalá.
    Lindecrantz, Kaj
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS) (Closed 20130701).
    Thordstein, M.
    Department of Clinical Neurophysiology, Institute of Neuroscience and Physiology, Sahlgrenska University Hospital, Göteborg, Sweden.
    Does indomethacin for closure of patent ductus arteriosus affect cerebral function?2010In: Acta Paediatrica, ISSN 0803-5253, E-ISSN 1651-2227, Vol. 99, no 10, p. 1493-1497Article in journal (Refereed)
    Abstract [en]

    Objective: To study whether indomethacin used in conventional dose for closure of patent ductus arteriosus affects cerebral function measured by Electroencephalograms (EEG) evaluated by quantitative measures. Study design: Seven premature neonates with haemodynamically significant persistent ductus arteriosus were recruited. EEG were recorded before, during and after an intravenous infusion of 0.2 mg/kg indomethacin over 10 min. The EEG was analysed by two methods with different degrees of complexity for the amount of low-activity periods (LAP, "suppressions") as an indicator of affection of cerebral function. Results: Neither of the two methods identified any change in the amount of LAPs in the EEG as compared to before the indomethacin infusion. Conclusion: Indomethacin in conventional dose for closure of patent ductus arteriosus does not affect cerebral function as evaluated by quantitative EEG.

  • 243.
    Fornara, Andrea
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Multifunctional nanomaterials for diagnostic and therapeutic applications2010Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In the past few years, the use of nanostructured materials in medical applications hasdramatically increased, both in the research phase and for clinical purposes, due to thepeculiar properties and the ability of such materials to interact at a similar scale withbiological entities. In this thesis, we developed tailored magnetic multifunctionalnanoparticles for diagnostic and therapeutic applications, such as detection ofbiomolecules, simultaneous enhanced magnetic resonance imaging (MRI), fluorescentvisualization and controlled drug release.For sensitive and selective detection of specific biomolecules, thermally blocked ironoxide nanoparticles with tailored magnetic properties were developed. The formation ofsuch nanoparticles has been studied both in terms of size and magnetic behavior in liquidsuspension or in polymer matrixes. These particles with narrow size distribution (averagediameter of 19 nm) were surface functionalized by antigen molecules and were used forthe detection of Brucella antibodies in biological samples. The binding of biomoleculesresults in an increase in the particle’s hydrodynamic diameter, affecting the relaxationbehavior that was monitored by magnetic measurements. This sensing system is a fastand sensitive biosensor with very low detection limits (0.05 μg/mL).Superparamagnetic iron oxide nanoparticles (SPION) have been synthesized withaverage diameter of 10-12 nm, narrow size distribution, high crystallinity and superiormagnetic properties as liquid suspensions or embedded in a bulk transparent magneticnanocomposite. These nanoparticles were synthesized in organic solvents and, after phasetransfer with Pluronic F127 amphiphilic copolymer, show excellent relaxivity properties(high r2/r1 ratio) and great contrast enhancement in T2 weighted MRI, confirmed by invivostudies of rat inner ear.SPION have been used as a component for different multifunctional nanostructures. Thefirst system based on poly (L,L lactide)-methoxy polyethylene glycol (PLLA-mPEG)copolymer has been prepared by an emulsion/evaporation process that lead to polymericnanoparticles containing several imaging agents, such as SPION, quantum dots (QDs)and gold nanorods as well as indomethacin (IMC) as therapeutic payload. With a similarprocedure, but using poly (lactide-co-glycolide) (PLGA-PEG-NH2) copolymer, a secondtype of multifunctional nanoparticles has been obtained. Their size can be tailored from70 to 150 nm varying synthesis parameters, such as the surfactant concentration or waterto oil ratio. Both these polymer-based multifunctional nanoparticles can be visualized byfluorescence microscopy (QDs photoemission) and MRI (SPION magnetization) and theycan be used for photothermal therapy (gold nanorods) and drug delivery. The last systemconsists of SPION nanoparticles coated with PLLA directly on the surface by an in-situpolymerization process. A hydrophobic drug was loaded before the phase transfer withPluronic F127 and these nanoparticles show simultaneous MRI T2 contrast enhancementas well as high drug loading and sustained delivery.Controlling the drug release rate is also a critical parameter for tailored therapeutictreatments, and for this reason we developed a novel drug delivery system based on theintegration of SPION and Pluronic F127 gels. IMC was loaded in the ferrogel (with atailored gelation temperature) and its release rate was triggered by applying an externalmagnetic field owing to the SPION magnetic properties.

    Download full text (pdf)
    FULLTEXT01
  • 244.
    Fornara, Andrea
    et al.
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Chiavarino, Annalisa
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Qin, Jian
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Toprak, Muhammet
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Muhammed, Mamoun
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    PLGA-PEG multifunctional nanoparticles for simultaneous drug delivery and visualizationIn: Journal of nanoparticle research, ISSN 1388-0764, E-ISSN 1572-896XArticle in journal (Other academic)
  • 245.
    Forsell, Caroline
    et al.
    KTH, School of Engineering Sciences (SCI), Mechanics, Biomechanics.
    Björck, Hanna M.
    Eriksson, Per
    Franco-Cereceda, Anders
    Gasser, T. Christian
    KTH, School of Engineering Sciences (SCI), Mechanics, Biomechanics.
    Biomechanical Properties of the Thoracic Aneurysmal Wall: Differences Between Bicuspid Aortic Valve and Tricuspid Aortic Valve Patients2014In: Annals of Thoracic Surgery, ISSN 0003-4975, E-ISSN 1552-6259, Vol. 98, no 1, p. 65-71Article in journal (Refereed)
    Abstract [en]

    Background. The prevalence for thoracic aortic aneurysms (TAAs) is significantly increased in patients with a bicuspid aortic valve (BAV) compared with patients who have a normal tricuspid aortic valve (TAV). TAA rupture is a life-threatening event, and biomechanics-based simulations of the aorta may help to disentangle the molecular mechanism behind its development and progression. The present study used polarized microscopy and macroscopic in vitro tensile testing to explore collagen organization and mechanical properties of TAA wall specimens from BAV and TAV patients. Methods. Circumferential sections of aneurysmal aortic tissue from BAV and TAV patients were obtained during elective operations. The distribution of collagen orientation was captured by a Bingham distribution, and finite element models were used to estimate constitutive model parameters from experimental load-displacement curves. Results. Collagen orientation was almost identical in BAV and TAV patients, with a highest probability of alignment along the circumferential direction. The strength was almost two times higher in BAV samples (0.834 MPa) than in TAV samples (0.443 MPa; p < 0.001). The collagen-related stiffness (C-f) was significantly increased in BAV compared with TAV patients (C-f = 7.45 MPa vs 3.40 MPa; p = 0.003), whereas the elastin-related stiffness was similar in both groups. A trend toward a decreased wall thickness was seen in BAV patients (p = 0.058). Conclusions. The aneurysmal aortas of BAV patients show a higher macroscopic strength, mainly due to an increased collagen-related stiffness, compared with TAV patients. The increased wall stiffness in BAV patients may contribute to the higher prevalence for TAAs in this group.

  • 246.
    Fransén, Erik
    KTH, School of Computer Science and Communication (CSC), Computational Biology, CB.
    Ionic Mechanisms in Peripheral Pain2014In: Computational Neuroscience / [ed] Blackwell, K.T., Elsevier, 2014, p. 23-51Chapter in book (Refereed)
    Abstract [en]

    Chronic pain constitutes an important and growing problem in society with large unmet needs with respect to treatment and clear implications for quality of life. Computational modeling is used to complement experimental studies to elucidate mechanisms involved in pain states. Models representing the peripheral nerve ending often address questions related to sensitization or reduction in pain detection threshold. In models of the axon or the cell body of the unmyelinated C-fiber, a large body of work concerns the role of particular sodium channels and mutations of these. Furthermore, in central structures: spinal cord or higher structures, sensitization often refers not only to enhanced synaptic efficacy but also to elevated intrinsic neuronal excitability. One of the recent developments in computational neuroscience is the emergence of computational neuropharmacology. In this area, computational modeling is used to study mechanisms of pathology with the objective of finding the means of restoring healthy function. This research has received increased attention from the pharmaceutical industry as ion channels have gained increased interest as drug targets. Computational modeling has several advantages, notably the ability to provide mechanistic links between molecular and cellular levels on the one hand and functions at the systems level on the other hand. These characteristics make computational modeling an additional tool to be used in the process of selecting pharmaceutical targets. Furthermore, large-scale simulations can provide a framework to systematically study the effects of several interacting disease parameters or effects from combinations of drugs.

  • 247.
    Fransén, Erik A.
    KTH, School of Computer Science and Communication (CSC), Computational Biology, CB.
    Mechanisms of Graded Persistent Activity: Implications for Epilepsy2008In: Computational Neuroscience in Epilepsy, Elsevier, 2008, p. 215-231Chapter in book (Other academic)
    Abstract [en]

    One major topic in epilepsy is factors contributing to neuronal excitability. This chapter considers depolarizing sources from cationic currents. These ion channels of the TRP-type are permeable to Na, K and sometimes Ca, and show a slow time dynamics. They can therefore provide the dendrites with integrative properties over seconds and perhaps even minutes. This makes them powerful as integrators of synaptic input. Further, their activation depends to a large degree on intracellular calcium. They may therefore during seizures become strongly activated and thereby further contribute to epileptogenic activity directly by depolarization and indirectly by their calcium permeability. Cationic currents are widely distributed throughout the nervous system, including cortical, cerebellar and subcortical neurons. This chapter describes the work in entorhinal cortex and, specifically, the plateau firing characteristics found in pyramidal cells of layer V. These cells show persistent action potential firing at plateaus, which may last over ten minutes. Intriguingly, these plateaus are graded in that input, synaptic or by current injection, can shift them up and down in frequency. After the original finding, graded plateaus have been found also in perirhinal cortex and amygdala. Functionally, cationic neuronal integrator capacity has been shown to be involved in sensory-motor integration. Finally, anticonvulsants like lamotrigine and phenytoin have been found to reduce depolarizations involving cationic currents. Cation currents may therefore be targets in treatments of epilepsy.

  • 248. Fraser, A G
    et al.
    Payne, N
    Mädler, C F
    Janerot-Sjoberg, B
    Hälsouniversitetet Linköping.
    Lind, B
    Grocott-Mason, R M
    Ionescu, A A
    Florescu, N
    Wilkenshoff, U
    Lancellotti, P
    Wütte, M
    Brodin, L A
    Feasibility and reproducibility of off-line tissue Doppler measurement of regional myocardial function during dobutamine stress echocardiography.2003In: European Journal of Echocardiography, ISSN 1525-2167, E-ISSN 1532-2114, Vol. 4, no 1, p. 43-53Article in journal (Refereed)
    Abstract [en]

    AIMS: Off-line post-processing of colour tissue Doppler from digital loops may allow objective quantification of dobutamine stress echocardiography. We assessed the reproducibility of off-line measurements of regional myocardial velocities.

    METHODS AND RESULTS: Nine observers analysed 10 studies, each making 2400 observations. Coefficients of variation in basal segments from apical windows, at rest and maximal stress, were 9-14% and 11-18% for peak systolic velocity, 16-18% and 17-19% for time-to-peak systolic velocity, 9-17% and 18-24% for systolic velocity time integral, and 18-23% and 21-27% for systolic acceleration. Coefficients of variation for diastolic velocities in basal segments at rest were 11-40%. Coefficients of variation for peak systolic velocity were 10-24% at rest and 14-28% at peak in mid segments, and 19-53% and 29-69% in apical segments. From parasternal windows coefficients of variation for peak systolic velocity were 14-16% in basal posterior, and 19-29% in mid-anterior segments. High variability makes measurement unreliable in apical and basal anterior septal segments. The feasibility of obtaining traces was tested in 92 subjects, and >90% in all basal and mid segments apart from the anterior septum.

    CONCLUSION: Quantification of myocardial functional reserve by off-line analysis of colour tissue Doppler acquired during dobutamine stress is feasible and reproducible in 11 segments of the left ventricle. The most reliable measurements are systolic velocities of longitudinal motion in basal segments.

  • 249.
    Fredenberg, Erik
    KTH, School of Engineering Sciences (SCI), Physics, Medical Imaging.
    Spectral Mammography with X-Ray Optics and a Photon-Counting Detector2009Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Early detection is vital to successfully treating breast cancer, and mammography screening is the most efficient and wide-spread method to reach this goal. Imaging low-contrast targets, while minimizing the radiation exposure to a large population is, however, a major challenge. Optimizing the image quality per unit radiation dose is therefore essential. In this thesis, two optimization schemes with respect to x-ray photon energy have been investigated: filtering the incident spectrum with refractive x-ray optics (spectral shaping), and utilizing the transmitted spectrum with energy-resolved photon-counting detectors (spectral imaging).

    Two types of x-ray lenses were experimentally characterized, and modeled using ray tracing, field propagation, and geometrical optics. Spectral shaping reduced dose approximately 20% compared to an absorption-filtered reference system with the same signal-to-noise ratio, scan time, and spatial resolution. In addition, a focusing pre-object collimator based on the same type of optics reduced divergence of the radiation and improved photon economy by about 50%.

    A photon-counting silicon detector was investigated in terms of energy resolution and its feasibility for spectral imaging. Contrast-enhanced tumor imaging with a system based on the detector was characterized and optimized with a model that took anatomical noise into account. Improvement in an ideal-observer detectability index by a factor of 2 to 8 over that obtained by conventional absorption imaging was found for different levels of anatomical noise and breast density. Increased conspicuity was confirmed by experiment. Further, the model was extended to include imaging of unenhanced lesions. Detectability of microcalcifications increased no more than a few percent, whereas the ability to detect large tumors might improve on the order of 50% despite the low attenuation difference between glandular and cancerous tissue. It is clear that inclusion of anatomical noise and imaging task in spectral optimization may yield completely different results than an analysis based solely on quantum noise.

    Download full text (pdf)
    FULLTEXT01
  • 250. Fredenberg, Erik
    et al.
    Berggren, Karl
    KTH, School of Engineering Sciences (SCI), Physics, Physics of Medical Imaging. Philips Health Systems, Sweden.
    Bartels, Matthias
    Erhard, Klaus
    Volumetric Breast-Density Measurement Using Spectral Photon-Counting Tomosynthesis: First Clinical Results2016In: Breast Imaging, IWDM 2016, Springer, 2016, p. 576-584Conference paper (Refereed)
    Abstract [en]

    Measurements of breast density have the potential to improve the efficiency and reduce the cost of screening mammography through personalized screening. Breast density has traditionally been evaluated from the dense area in a mammogram, but volumetric assessment methods, which measure the volumetric fraction of fibro-glandular tissue in the breast, are potentially more consistent and physically sound. The purpose of the present study is to evaluate a method for measuring the volumetric breast density using photon-counting spectral tomo-synthesis. The performance of the method was evaluated using phantom measurements and clinical data from a small population (n = 18). The precision was determined to be 2.4 percentage points (pp) of volumetric breast density. Strong correlations were observed between contralateral (R-2 = 0.95) and ipsilateral (R-2 = 0.96) breast-density measurements. The measured breast density was anti-correlated to breast thickness, as expected, and exhibited a skewed distribution in the range [3.7 %, 55 %] and with a median of 18 %. We conclude that the method yields promising results that are consistent with expectations. The relatively high precision of the method may enable novel applications such as treatment monitoring.

2345678 201 - 250 of 1085
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf