| 1. |
- Nilsson Hammar, Anna, et al.
(author)
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Introduction
- 2022
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In: Gender, materiality, and Politics : Essays on the making of power - Essays on the making of power. - 9789189361379 ; , s. 7-21
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Book chapter (other academic/artistic)
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| 2. |
- Antoni, Per, et al.
(author)
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Europium confined cyclen dendrimers with photophysically active triazoles
- 2008
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In: Journal of Materials Chemistry. - : Royal Society of Chemistry (RSC). - 0959-9428 .- 1364-5501. ; 18:22, s. 2545-2554
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Journal article (peer-reviewed)abstract
- Dendrimers up to the fourth generation (G1-G4) were successfully synthesized via the efficient copper catalyzed 1,3-dipolar cycloaddition between primary alkynes and azides (CuAAC), also referred to as a click reaction. The synthetic protocol involved the preparation of presynthesized dendron wedges that subsequently were attached to a tetra-valent alkyne functional cyclen core. These constructed structures integrated stable triazole groups "intra-locked'' between the cyclen and dendron wedges. The incorporation of a lanthanide metal ion, europium, into the interior of all cyclen dendrimers was monitored by FT-IR. Interestingly, the photophysical results showed that the proximate triazole not only acts as a stable linker but also as a sensitizers, transferring its singlet-singlet excitation in the ultraviolet region (270-290 nm) to the partially filled luminescent lanthanide 4f shell. An increase of luminescence decay time from the lanthanide D-5(0) -> F-7(2) emission was observed with increasing dendrimer size, indicating that the shielding effect of the dendron wedges is important for the relaxation of the photo-excitation and energy transfer. To the best of our knowledge, this is the first time a set of dendron wedges have successfully been attached to a cyclen metal ion cage via the versatile click reaction. Furthermore, the produced triazoles intra-locked in close proximity to the macrocycle core elucidated an interesting photophysical function.
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| 4. |
- Nyström, Andreas, et al.
(author)
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Characterization of Poly(norbornene) Dendronized Polymers Prepared by Ring-Opening Metathesis Polymerization of Dendron Bearing Monomers
- 2006
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In: Macromolecules. - : American Chemical Society (ACS). - 0024-9297 .- 1520-5835. ; 39:21, s. 7241-7249
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Journal article (peer-reviewed)abstract
- The preparation and characterization of a series of first to fourth generation dendronized poly-(norbornene)s are presented. The monomers were synthesized in a divergent fashion from 5-norbornene-2-methanol, utilizing the acetonide protected anhydride of 2,2-bis(methylol)propionic acid. The norbornenyl bearing dendrons were polymerized by ring-opening metathesis polymerization, and it was found that the Grubbs' first generation catalyst resulted in polymers with lower polydispersity compared to the materials obtained when employing the second generation catalyst. Two series of first to fourth generation polymers were characterized by DSC, SEC, and dynamic rheological measurements. In addition, it was found that the fourth generation material could form regular, porous membranes and birefringent fibers. The membranes were characterized with atomic force and optical microscopy. The birefringent fibers were analyzed with X-ray diffraction, polarized FTIR, and polarized optical microscopy.
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| 6. |
- Sator, Lea, et al.
(author)
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Overdiagnosis of COPD in Subjects With Unobstructed Spirometry A BOLD Analysis
- 2019
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In: Chest. - : Elsevier BV. - 0012-3692 .- 1931-3543. ; 156:2, s. 277-288
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Journal article (peer-reviewed)abstract
- BACKGROUND: There are several reports on underdiagnosis of COPD, while little is known about COPD overdiagnosis and overtreatment. We describe the overdiagnosis and the prevalence of spirometrically defined false positive COPD, as well as their relationship with overtreatment across 23 population samples in 20 countries participating in the BOLD Study between 2003 and 2012.METHODS: A false positive diagnosis of COPD was considered when participants reported a doctor's diagnosis of COPD, but postbronchodilator spirometry was unobstructed (FEV1/FVC > LLN). Additional analyses were performed using the fixed ratio criterion (FEV1/FVC < 0.7).RESULTS: Among 16,177 participants, 919 (5.7%) reported a previous medical diagnosis of COPD. Postbronchodilator spirometry was unobstructed in 569 subjects (61.9%): false positive COPD. A similar rate of overdiagnosis was seen when using the fixed ratio criterion (55.3%). In a subgroup analysis excluding participants who reported a diagnosis of "chronic bronchitis" or "emphysema" (n = 220), 37.7% had no airflow limitation. The site-specific prevalence of false positive COPD varied greatly, from 1.9% in low- to middle-income countries to 4.9% in high-income countries. In multivariate analysis, overdiagnosis was more common among women, and was associated with higher education; former and current smoking; the presence of wheeze, cough, and phlegm; and concomitant medical diagnosis of asthma or heart disease. Among the subjects with false positive COPD, 45.7% reported current use of respiratory medication. Excluding patients with reported asthma, 34.4% of those with normal spirometry still used a respiratory medication.CONCLUSIONS: False positive COPD is frequent. This might expose nonobstructed subjects to possible adverse effects of respiratory medication.
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| 9. |
- Abedini, Fereshteh, 1989-
(author)
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2D and 3D Halftoning for Appearance Reproduction
- 2023
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Doctoral thesis (other academic/artistic)abstract
- The appearance of an object is determined by its chromatic and geometric qualities in its surrounding environment using four optical parameters: color, gloss, translucency, and surface texture. Reconstructing the appearance of objects is of great importance in many applications, including creative industries, packaging, fine-art reproduction, medical simulation, and prosthesis-making. Printers are reproduction devices capable of replicating objects’ appearance in 2D and 3D forms. With the introduction of new printing technologies, new inks and materials, and demands for innovative applications, creating accurate reproduction of the desired visual appearance has become challenging. Thus, the appearance reproduction workflow requires improvements and adaptations. Accurate color reproduction is a critical quality measure in reproducing the desired appearance in any printing process. However, printers are devices with a limited number of inks that can either print a dot or leave it blank at a specific position on a substrate; hence, to reproduce different colors, optimal placement of the available inks is needed. Halftoning is a technique that deals with this challenge by generating a spatial distribution of the available inks that creates an illusion of the target color when viewed from a sufficiently large distance. Halftoning is a fundamental part of the color reproduction task in any full-color printing pipeline, and it is an effective technique to increase the potential of printing realistic and complex appearances. Although halftoning has been used in 2D printing for many decades, it still requires improvements in reproducing fine details and structures of images. Moreover, the emergence of new technologies in 3D printing introduces a higher degree of freedom and more parameters to the field of appearance reproduction. Therefore, there is a critical need for extensive studies to revisit existing halftoning algorithms and develop novel approaches to produce high quality prints that match the target appearance faithfully. This thesis aims at developing halftoning algorithms to improve appearance reproduction in 2D and 3D printing. Contributions of this thesis in the 2D domain is a dynamic sharpness-enhancing halftoning approach, which adaptively varies the local sharpness of the halftone image based on different textures in the original image for realistic appearance printing. The results show improvements in halftone quality in terms of sharpness, preserving structural similarity, and decreasing color reproduction error. The main contribution of this thesis in 3D printing is extending a high quality 2D halftoning algorithm to the 3D domain. The proposed method is then integrated with a multi-layer printing approach, where ink is deposited at variable depths to improve the reproduction of tones and fine details. Results demonstrate that the proposed method accurately reproduces tones and details of the target appearance. Another contribution of this thesis is studying the effect of halftoning on the perceived appearance of 3D printed surfaces. According to the results, changing the dot placement based on the elevation variation of the underlying geometry can potentially control the perception of the 3D printed appearance. It implies that the choice of halftone may prove helpful in eliminating unwanted artifacts, enhancing the object’s geometric features, and producing a more accurate 3D appearance. The proposed methods in this thesis have been evaluated using different printing techniques.
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| 10. |
- Abedini, Fereshteh, et al.
(author)
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3D Halftoning based on Iterative Method Controlling Dot Placement
- 2020
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Conference paper (peer-reviewed)abstract
- Realistic appearance reproduction is of great importance in 3D printing’s applications. Halftoning as a necessary process in printing has a great impact on creating visually pleasant appearance. In this article, we study the aspects of adapting and applying Iterative Method Controlling Dot Placement (IMCDP) to halftone three-dimensional surfaces. Our main goal is to extend the 2D algorithm to a 3D halftoning approach with minor modifications. The results show high-quality reproduction for all gray tones. The 3D halftoning algorithm is not only free of undesirable artifacts, it also produces fully symmetric and wellformed halftone structures even in highlight and shadow regions.
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