| 21. |
- Brusini, Irene, et al.
(författare)
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Shape Information Improves the Cross-Cohort Performance of Deep Learning-Based Segmentation of the Hippocampus
- 2020
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Ingår i: Frontiers in Neuroscience. - : Frontiers Media S.A.. - 1662-4548 .- 1662-453X. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- Performing an accurate segmentation of the hippocampus from brain magnetic resonance images is a crucial task in neuroimaging research, since its structural integrity is strongly related to several neurodegenerative disorders, including Alzheimer's disease (AD). Some automatic segmentation tools are already being used, but, in recent years, new deep learning (DL)-based methods have been proven to be much more accurate in various medical image segmentation tasks. In this work, we propose a DL-based hippocampus segmentation framework that embeds statistical shape of the hippocampus as context information into the deep neural network (DNN). The inclusion of shape information is achieved with three main steps: (1) a U-Net-based segmentation, (2) a shape model estimation, and (3) a second U-Net-based segmentation which uses both the original input data and the fitted shape model. The trained DL architectures were tested on image data of three diagnostic groups [AD patients, subjects with mild cognitive impairment (MCI) and controls] from two cohorts (ADNI and AddNeuroMed). Both intra-cohort validation and cross-cohort validation were performed and compared with the conventional U-net architecture and some variations with other types of context information (i.e., autocontext and tissue-class context). Our results suggest that adding shape information can improve the segmentation accuracy in cross-cohort validation, i.e., when DNNs are trained on one cohort and applied to another. However, no significant benefit is observed in intra-cohort validation, i.e., training and testing DNNs on images from the same cohort. Moreover, compared to other types of context information, the use of shape context was shown to be the most successful in increasing the accuracy, while keeping the computational time in the order of a few minutes.
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| 22. |
- Caesar, C., et al.
(författare)
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Beyond the neutron drip line: The unbound oxygen isotopes O-25 and O-26
- 2013
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Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993 .- 0556-2813. ; 88:3
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Tidskriftsartikel (refereegranskat)abstract
- The very neutron-rich oxygen isotopes O-25 and O-26 are investigated experimentally and theoretically. The unbound states are populated in an experiment performed at the R3B-LAND setup at GSI via proton-knockout reactions from F-26 and F-27 at relativistic energies around 442 and 414 MeV/nucleon, respectively. From the kinematically complete measurement of the decay into O-24 plus one or two neutrons, the O-25 ground-state energy and width are determined, and upper limits for the O-26 ground-state energy and lifetime are extracted. In addition, the results provide indications for an excited state in O-26 at around 4 MeV. The experimental findings are compared to theoretical shell-model calculations based on chiral two- and three-nucleon (3N) forces, including for the first time residual 3N forces, which are shown to be amplified as valence neutrons are added.
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| 23. |
- Cervin, Anders, et al.
(författare)
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One-year low-dose erythromycin treatment of persistent chronic sinusitis after sinus surgery: clinical outcome and effects on mucociliary parameters and nasal nitric oxide.
- 2002
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Ingår i: Otolaryngology: Head and Neck Surgery. - : Wiley. - 0194-5998 .- 1097-6817. ; 126:5, s. 481-489
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: In 17 patients with chronic sinusitis persistent after sinus surgery, long-term, low-dose erythromycin therapy was tested. The aim of the investigation was to study the clinical outcome and effects on nasal nitric oxide (NO), ciliary beat frequency (CBF), and mucociliary transport (saccharine transit time). STUDY DESIGN AND SETTING: We conducted a prospective open study at a tertiary teaching hospital. Symptoms were assessed using visual analog scales. NO was measured using a chemiluminescence analyzer, and mucociliary transport was measured with the saccharine crystal technique. CBF was measured in nasal brush samples using a phase contrast microscope. All patients were treated with erythromycin succinate 250 mg 2x daily or clarithromycin 250 mg 1x daily and were assessed after 3 months. In cases where there was no response, treatment was abandoned. The remaining patients (responders) were reassessed after 12 months of treatment. RESULTS: Of 17 patients, 12 responded to treatment. The 12-month follow-up showed an improvement in saccharine transit time (P < 0.05) but no significant change in CBF. There was a trend toward an increase in NO (P = 0.12). Endoscopic nasal examination scoring improved significantly (P < 0.01). In the visual analog scale scoring, the most pronounced improvements were seen in nasal congestion, sticky secretion, and runny nose at 3 and 12 months (P < 0.01). Improvements were also seen in headache (P < 0.05). CONCLUSION: The present study suggests that long-term, low-dose treatment with erythromycin is effective in persistent chronic sinusitis that does not respond to sinus surgery or systemic steroid/antibiotic treatment. SIGNIFICANCE: Long-term, low-dose erythromycin therapy seems to be a promising alternative when more conventional therapy fails. However, placebo-controlled studies are needed to validate the potential of this treatment.
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| 24. |
- Freund-Levi, Yvonne, 1956-, et al.
(författare)
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Effects of omega-3 fatty acids on inflammatory markers in cerebrospinal fluid and plasma in Alzheimer's disease : the OmegAD study
- 2009
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Ingår i: Dementia and Geriatric Cognitive Disorders. - : S. Karger. - 1420-8008 .- 1421-9824. ; 27:5, s. 481-490
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: omega-3 fatty acids (omega-3 FAs) found in dietary fish or fish oils are anti-inflammatory agents that may influence Alzheimer's disease (AD).OBJECTIVE: To study the effects of dietary omega-3 FA supplementation on inflammatory markers in cerebrospinal fluid (CSF) and plasma from patients with mild to moderate AD.METHODS: Thirty-five patients (70.3 +/- 8.2 years) were randomized to a daily intake of 2.3 g omega-3 FAs or placebo for 6 months. The inflammatory markers interleukin (IL)-6, tumour necrosis factor-alpha and soluble interleukin-1 receptor type II (sIL-1RII) were analysed in CSF and plasma at baseline and at 6 months. The AD markers tau-protein, hyperphosphorylated tau-protein and beta-amyloid (Abeta(1-42)) were assessed in CSF. High-sensitivity C-reactive protein was assessed in plasma. A possible relation to the APOE genotype was investigated.RESULTS: There was no significant treatment effect of omega-3 FAs on inflammatory and AD biomarkers in CSF or on inflammatory markers in plasma, nor was there any relation with APOE. A significant correlation was observed at baseline between sIL-1RII and Abeta(1-42) levels in CSF.CONCLUSIONS: Treatment of AD patients with omega-3 FAs for 6 months did not influence inflammatory or biomarkers in CSF or plasma. The correlation between sIL-1RII and Abeta(1-42) may reflect the reciprocal interactions between IL-1 and Abeta peptides.
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| 25. |
- Gabrielsson, Jon, et al.
(författare)
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Multivariate methods in the development of a new tablet formulation : optimization and validation
- 2004
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Ingår i: Drug Development and Industrial Pharmacy. - New York : M. Dekker. - 0363-9045 .- 1520-5762. ; 30:10, s. 1037-1049
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Tidskriftsartikel (refereegranskat)abstract
- In a previous study of the development of a tablet formulation approximately 100 excipients were characterized in screening experiments using multivariate design. Acceptable values for important responses were obtained with some of the formulations. The relationships between the properties of the excipients and the responses were evaluated using PLS. In this study additional experiments were performed in order to validate models obtained from the screening study and to find a formulation of suitable composition with desired tablet properties. A formulation with the desired disintegration time was found with the additional experiments and the agreement between observed and predicted values was fair for the tablets that did disintegrate. A limitation of this study was that tablets from four experiments did not disintegrate within the set time limit. The lack of agreement between observed and predicted values of these four experiments was probably due to the nature of one of the factors in the design. Considering the reduced experimental design the results are still encouraging.
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| 26. |
- Gabrielsson, Jon, et al.
(författare)
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Multivariate Methods in the Development of a New Tablet Formulation : Excipient Mixtures and Principal Properties
- 2006
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Ingår i: Drug Development and Industrial Pharmacy. - New York : M. Dekker. - 0363-9045 .- 1520-5762. ; 32:1, s. 7-20
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Tidskriftsartikel (refereegranskat)abstract
- A tablet formulation for direct compression has previously been studied using multivariate design. An optimization study of one of the most important tablet properties, disintegration time, revealed that excipients with Principal Properties (PP's) that were predicted as suitable by the model were not represented within the studied material.The feasibility of using mixtures of excipients in the multivariate approach to tablet formulation to solve this problem has been investigated in the present study. By mixing different excipients of the same excipient class, it should be possible to obtain mixtures with the predicted PP's, which in turn should give a formulation with the desired properties. In order to investigate the utility of this approach, separate mixture designs were applied to both binders and fillers (diluents).As reported here, the Partial Least Squares Projections to Latent Structures (PLS) model developed in the previously published screening study has been validated in the sense that the interesting region of the PP space identified in it has been shown to contain excipients, pure or mixed, that give the formulation suitable properties. Formulations with suitable properties were found with the mixture experiments. The local models also offer several alternatives for the composition of the formulation that yield the desired disintegration time.
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| 27. |
- Gabrielsson, Jon, et al.
(författare)
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Multivariate Methods in the Development of a New Tablet Formulation
- 2003
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Ingår i: Drug Development and Industrial Pharmacy. - New York : Marcel Dekker. - 0363-9045 .- 1520-5762. ; 29:10, s. 1053-1075
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Tidskriftsartikel (refereegranskat)abstract
- The overall objective of this article is to use an efficient approach to find a suitable tablet formulation for direct compression. By using traditional approaches to statistical experimental design in tablet formulation, the number of experiments quickly grows when many descriptive variables or many excipients are included. To facilitate the screening process, a multivariate design, which allows a systematical evaluation of a large number of excipients with a limited number of experiments, was implemented. Formulations with acceptable values for disintegration time and crushing strength were obtained with some of the formulations in the present study. The multivariate experimental design strategy yielded PLS models that will be used to identify a region of interest for the optimization. The strategy is general and can be applied in many different areas of pharmaceutical research and development.
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| 28. |
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| 29. |
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| 30. |
- Ge, Yu, 1995, et al.
(författare)
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Experimental Validation of Single Base Station 5G mm Wave Positioning: Initial Findings
- 2022
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Ingår i: 2022 25th International Conference on Information Fusion, FUSION 2022. - Piscataway : IEEE.
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Konferensbidrag (refereegranskat)abstract
- 5G cellular networks can utilize millimeter wave signals, and support large bandwidths and large antenna arrays, which provide more geometric-based signals and higher delay and angle resolutions. These merits bring new opportunities in positioning the user with limited infrastructure through the use of combined angle and delay information. However, there are many practical challenges to overcome, in order to have a functioning single base station 5G mmWave positioning system. In this paper, we describe a deployed single base station mmWave positioning system, and provide an example of the measurement data. Furthermore, we perform measurement validation on a limited measurement data set by performing base station localization. Additional evaluations performed on simulation model data provide guidelines on the required size of the data set and receiver antenna configuration, which will be implemented in upcoming measurements.
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