| 1. |
- Sababi, Majid, et al.
(författare)
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Influence of polyaniline and ceria nanoparticle additives on corrosion protection of a UV-cure coating on carbon steel
- 2014
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Ingår i: Corrosion Science. - : Elsevier BV. - 0010-938X .- 1879-0496. ; 84, s. 189-197
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Tidskriftsartikel (refereegranskat)abstract
- Influence of a few percents additives of polyaniline doped with phosphoric acid (PAni-PA) and ceria nanoparticle on corrosion protection of a new ultraviolet (UV)-cure polyester acrylate coating have been studied for coil coating on carbon steel by electrochemical measurements during exposure to a NaCl solution. The results demonstrate that the presence of ceria nanoparticles improves the barrier property and stability of the coating. Adding the PAni-PA results in active corrosion protection for carbon steel due to passivation of the steel, and the combination of both additives greatly enhances the protection property over that of the coating matrix alone.
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| 2. |
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| 3. |
- Alsved, Julia, et al.
(författare)
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Label-free separation of peripheral blood mononuclear cells from whole blood by gradient acoustic focusing
- 2024
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Ingår i: Scientific Reports. - 2045-2322. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- Efficient techniques for separating target cells from undiluted blood are necessary for various diagnostic and research applications. This paper presents acoustic focusing in dense media containing iodixanol to purify peripheral blood mononuclear cells (PBMCs) from whole blood in a label-free and flow-through format. If the blood is laminated or mixed with iodixanol solutions while passing through the resonant microchannel, all the components (fluids and cells) rearrange according to their acoustic impedances. Red blood cells (RBCs) have higher effective acoustic impedance than PBMCs. Therefore, they relocate to the pressure node despite the dense medium, while PBMCs stay near the channel walls due to their negative contrast factor relative to their surrounding medium. By modifying the medium and thus tuning the contrast factor of the cells, we enriched PBMCs relative to RBCs by a factor of 3600 to 11,000 and with a separation efficiency of 85%. That level of RBC depletion is higher than most other microfluidic methods and similar to that of density gradient centrifugation. The current acoustophoretic chip runs up to 20 µl/min undiluted whole blood and can be integrated with downstream analysis.
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| 4. |
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| 5. |
- Antfolk, Maria, et al.
(författare)
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A single inlet two-stage acoustophoresis chip enabling tumor cell enrichment from white blood cells
- 2015
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Ingår i: Lab on a Chip. - 1473-0189. ; 15:9, s. 2102-2109
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Tidskriftsartikel (refereegranskat)abstract
- Metastatic disease is responsible for most cancer deaths, and hematogenous spread through circulating tumor cells (CTC) is a prerequisite for tumor dissemination. CTCs may undergo epithelial–mesenchymal transition where many epithelial cell characteristics are lost. Therefore, CTC isolation systems relying on epithelial cell markers are at risk of losing important subpopulations of cells. Here, a simple acoustophoresis-based cell separation instrument is presented. Cells are uniquely separated while maintained in their initial suspending medium, thus eliminating the need for a secondary cell-free medium to hydrodynamically pre-position them before the separation. When characterizing the system using polystyrene particles, 99.6 ± 0.2% of 7 μm diameter particles were collected through one outlet while 98.8 ± 0.5% of 5 μm particles were recovered through a second outlet. Prostate cancer cells (DU145) spiked into blood were enriched from white blood cells at a sample flow rate of 100 μL min−1 providing 86.5 ± 6.7% recovery of the cancer cells with 1.1 ± 0.2% contamination of white blood cells. By increasing the acoustic intensity a recovery of 94.8 ± 2.8% of cancer cells was achieved with 2.2 ± 0.6% contamination of white blood cells. The single inlet approach makes this instrument insensitive to acoustic impedance mismatch; a phenomenon reported to importantly affect accuracy in multi-laminar flow stream acoustophoresis. It also offers a possibility of concentrating the recovered cells in the chip, as opposed to systems relying on hydrodynamic pre-positioning which commonly dilute the target cells.
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| 6. |
- Antfolk, Maria, et al.
(författare)
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Acoustofluidic, label-free separation and simultaneous concentration of rare tumor cells from white blood cells
- 2015
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Ingår i: Analytical Chemistry. - : American Chemical Society (ACS). - 1520-6882 .- 0003-2700. ; 87:18, s. 9322-9328
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Tidskriftsartikel (refereegranskat)abstract
- Enrichment of rare cells from peripheral blood has emerged as a means to enable noninvasive diagnostics and development of personalized drugs, commonly associated with a prerequisite to concentrate the enriched rare cell population prior to molecular analysis or culture. However, common concentration by centrifugation has important limitations when processing low cell numbers. Here, we report on an integrated acoustophoresis-based rare cell enrichment system combined with integrated concentration. Polystyrene 7 μm microparticles could be separated from 5 μm particles with a recovery of 99.3 ± 0.3% at a contamination of 0.1 ± 0.03%, with an overall 25.7 ± 1.7-fold concentration of the recovered 7 μm particles. At a flow rate of 100 μL/min, breast cancer cells (MCF7) spiked into red blood cell-lysed human blood were separated with an efficiency of 91.8 ± 1.0% with a contamination of 0.6 ± 0.1% from white blood cells with a 23.8 ± 1.3-fold concentration of cancer cells. The recovery of prostate cancer cells (DU145) spiked into whole blood was 84.1 ± 2.1% with 0.2 ± 0.04% contamination of white blood cells with a 9.6 ± 0.4-fold concentration of cancer cells. This simultaneous on-chip separation and concentration shows feasibility of future acoustofluidic systems for rapid label-free enrichment and molecular characterization of circulating tumor cells using peripheral venous blood in clinical practice.
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| 7. |
- Antfolk, Maria, et al.
(författare)
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Focusing of sub-micrometer particles and bacteria enabled by two-dimensional acoustophoresis.
- 2014
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Ingår i: Lab on a Chip. - : Royal Society of Chemistry (RSC). - 1473-0189. ; 14:15, s. 2791-2799
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Tidskriftsartikel (refereegranskat)abstract
- Handling of sub-micrometer bioparticles such as bacteria are becoming increasingly important in the biomedical field and in environmental and food analysis. As a result, there is an increased need for less labor-intensive and time-consuming handling methods. Here, an acoustophoresis-based microfluidic chip that uses ultrasound to focus sub-micrometer particles and bacteria, is presented. The ability to focus sub-micrometer bioparticles in a standing one-dimensional acoustic wave is generally limited by the acoustic-streaming-induced drag force, which becomes increasingly significant the smaller the particles are. By using two-dimensional acoustic focusing, i.e. focusing of the sub-micrometer particles both horizontally and vertically in the cross section of a microchannel, the acoustic streaming velocity field can be altered to allow focusing. Here, the focusability of E. coli and polystyrene particles as small as 0.5 μm in diameter in microchannels of square or rectangular cross sections, is demonstrated. Numerical analysis was used to determine generic transverse particle trajectories in the channels, which revealed spiral-shaped trajectories of the sub-micrometer particles towards the center of the microchannel; this was also confirmed by experimental observations. The ability to focus and enrich bacteria and other sub-micrometer bioparticles using acoustophoresis opens the research field to new microbiological applications.
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| 8. |
- Augustsson, Hanna, et al.
(författare)
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Determinants for the use and de-implementation of low-value care in health care : a scoping review.
- 2021
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Ingår i: Implementation Science Communications. - : Springer Science and Business Media LLC. - 2662-2211. ; 2:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: A considerable proportion of interventions provided to patients lack evidence of their effectiveness. This implies that patients may receive ineffective, unnecessary or even harmful care. However, despite some empirical studies in the field, there has been no synthesis of determinants impacting the use of low-value care (LVC) and the process of de-implementing LVC.AIM: The aim was to identify determinants influencing the use of LVC, as well as determinants for de-implementation of LVC practices in health care.METHODS: A scoping review was performed based on the framework by Arksey and O'Malley. We searched four scientific databases, conducted snowball searches of relevant articles and hand searched the journal Implementation Science for peer-reviewed journal articles in English. Articles were included if they were empirical studies reporting on determinants for the use of LVC or de-implementation of LVC. The abstract review and the full-text review were conducted in duplicate and conflicting decisions were discussed until consensus was reached. Data were charted using a piloted data charting form and the determinants were inductively coded and categorised in an iterative process conducted by the project group.RESULTS: In total, 101 citations were included in the review. Of these, 92 reported on determinants for the use of LVC and nine on determinants for de-implementation. The studies were conducted in a range of health care settings and investigated a variety of LVC practices with LVC medication prescriptions, imaging and screening procedures being the most common. The identified determinants for the use of LVC as well as for de-implementation of LVC practices broadly concerned: patients, professionals, outer context, inner context, process and evidence and LVC practice. The results were discussed in relation to the Consolidated Framework for Implementation Research.CONCLUSION: The identified determinants largely overlap with existing implementation frameworks, although patient expectations and professionals' fear of malpractice appear to be more prominent determinants for the use and de-implementation of LVC. Thus, existing implementation determinant frameworks may require adaptation to be transferable to de-implementation. Strategies to reduce the use of LVC should specifically consider determinants for the use and de-implementation of LVC.REGISTRATION: The review has not been registered.
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| 9. |
- Augustsson, Hanna, et al.
(författare)
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National governance of de-implementation of low-value care : a qualitative study in Sweden
- 2022
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Ingår i: Health Research Policy and Systems. - : BMC. - 1478-4505. ; 20:1
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Tidskriftsartikel (refereegranskat)abstract
- Background The de-implementation of low-value care (LVC) is important to improving patient and population health, minimizing patient harm and reducing resource waste. However, there is limited knowledge about how the de-implementation of LVC is governed and what challenges might be involved. In this study, we aimed to (1) identify key stakeholders' activities in relation to de-implementing LVC in Sweden at the national governance level and (2) identify challenges involved in the national governance of the de-implementation of LVC. Methods We used a purposeful sampling strategy to identify stakeholders in Sweden having a potential role in governing the de-implementation of LVC at a national level. Twelve informants from nine stakeholder agencies/organizations were recruited using snowball sampling. Semi-structured interviews were conducted, transcribed and analysed using inductive thematic analysis. Results Four potential activities for governing the de-implementation of LVC at a national level were identified: recommendations, health technology assessment, control over pharmaceutical products and a national system for knowledge management. Challenges involved included various vested interests that result in the maintenance of LVC and a low overall priority of working with the de-implementation of LVC compared with the implementation of new evidence. Ambiguous evidence made it difficult to clearly determine whether a practice was LVC. Unclear roles, where none of the stakeholders perceived that they had a formal mandate to govern the de-implementation of LVC, further contributed to the challenges involved in governing that de-implementation. Conclusions Various activities were performed to govern the de-implementation of LVC at a national level in Sweden; however, these were limited and had a lower priority relative to the implementation of new methods. Challenges involved relate to unfavourable change incentives, ambiguous evidence, and unclear roles to govern the de-implementation of LVC. Addressing these challenges could make the national-level governance of de-implementation more systematic and thereby help create favourable conditions for reducing LVC in healthcare.
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| 10. |
- Augustsson, Per, et al.
(författare)
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Acoustofluidics 11: Affinity specific extraction and sample decomplexing using continuous flow acoustophoresis.
- 2012
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Ingår i: Lab on a Chip. - : Royal Society of Chemistry (RSC). - 1473-0189 .- 1473-0197. ; 12:10, s. 1742-1752
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Tidskriftsartikel (refereegranskat)abstract
- Acoustic standing wave technology combined with ligand complexed microbeads offers a means for affinity specific selection of target analytes from complex samples. When realized in a microfluidic format we can capitalize on laminar flow and acoustic forces that can drive cells or microbeads across fluid interfaces. Given this, we have the ability to perform carrier fluid (suspending medium) exchange operations in continuous flow in microfluidic chips based solely on acoustofluidic properties. A key issue here is to ensure that a minimum of the original carrier fluid follows the cells/particles across the fluid interface. Simple processing protocols can be achieved that may outperform macroscale magnetic bead-based sample extraction or centrifugation steps, which can also be straightforwardly integrated with downstream analytical instrumentation. This tutorial outlines some basic fluidic configurations for acoustophoresis based sample decomplexing and details the different system parameters that will impact the outcome of an acoustophoresis based affinity extraction experiment or a cell medium exchange step. Examples are given of both targeted extraction of microbes and selective elusion of molecular species.
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