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- Bunk, Richard, et al.
(författare)
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Actomyosin motility on nanostructured surfaces
- 2003
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Ingår i: Biochemical and Biophysical Research Communications. - 1090-2104. ; 301:3, s. 783-788
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Tidskriftsartikel (refereegranskat)abstract
- We have here, for the first time, used nanofabrication techniques to reproduce aspects of the ordered actomyosin arrangement in a muscle cell. The adsorption of functional heavy meromyosin (HMM) to five different resist polymers was first assessed. One group of resists (MRL-6000.1XP and ZEP-520) consistently exhibited high quality motility of actin filaments after incubation with HMM. A second group (PMMA-200, PMMA-950, and MRI-9030) generally gave low quality of motility with only few smoothly moving filaments. Based on these findings electron beam lithography was applied to a bi-layer resist system with PMMA-950 on top of MRL-6000.1XP. Grooves (100-200 nm wide) in the PMMA layer were created to expose the MRL-6000.1XP surface for adsorption of HMM and guidance of actin filament motility. This guidance was quite efficient allowing no U-turns of the filaments and approximately 20 times higher density of moving filaments in the grooves than on the surrounding PMMA.
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| 4. |
- Bunk, Richard, et al.
(författare)
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Guiding molecular motors with nano-imprinted structures
- 2005
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Ingår i: Japanese Journal of Applied Physics. - 0021-4922. ; 44:5A, s. 3337-3340
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Tidskriftsartikel (refereegranskat)abstract
- This work, for the first time, demonstrates that nano-imprinted samples, with 100 nm wide polymer lines, can act as guides for molecular motors consisting of motor proteins actin and myosin. The motor protein function was characterized using fluorescence microscopy and compared to actomyosin motility on non-structured nitrocellulose surfaces. Our results open for further use of the nano-imprint technique in the production of disposable chips for bio-nanotechnological applications and miniaturized biological test systems. We discuss how the nano-imprinted motor protein assay system may be optimized and also how it compares to previously tested assay systems involving low-resolution UV-lithography and low throughput but high-resolution electron beam lithography.
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| 6. |
- Bunk, Richard, et al.
(författare)
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Guiding motor-propelled molecules with nanoscale precision through silanized bi-channel structures
- 2005
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Ingår i: Nanotechnology. - : IOP Publishing. - 0957-4484 .- 1361-6528. ; 16:6, s. 710-717
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Tidskriftsartikel (refereegranskat)abstract
- We report on the design and fabrication of a channel structure for high precision guidance and achieving excellent confinement properties for motor-propelled molecular shuttles. The techniques used to manufacture the channel structure are mainly e-beam lithography and selective monolayer functionalization. The structure consists of two lateral layers of concentric channels on a SiO2 surface made biocompatible with the molecular motors. The quality and advantages of the design are demonstrated by experiments using the motor proteins actin and myosin. The special channel geometry leads to stable biochemical conditions with full motor protein functionality. ATP is sufficiently supplied to all parts of the structure by dedicated service channels, as is the venting of ADP and P-i (inorganic phosphorus). Channels of different widths (100-700 nm) and shapes are fabricated and measurements made on them.
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| 7. |
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| 8. |
- Bunk, Richard, et al.
(författare)
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Towards a 'nano-traffic' system powered by molecular motors
- 2003
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Ingår i: Microelectronic Engineering. - 1873-5568. ; 67-8, s. 899-904
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Tidskriftsartikel (refereegranskat)abstract
- In this work, we reconstructed in vitro the behavior of two motor proteins-myosin and actin-responsible for the mechanical action of muscle cells. By transferring this in vivo system to an artificial environment, we were able to study the interaction between the proteins in more detail, as well as investigating the central mechanism of force production. Nm-patterning by e-beam lithography (EBL) could restore parts of the in vivo protein order, essential for potential nanotechnological applications. Much work was put into establishing the necessary compatibility between the biological and nano-lithographical processes. A range of EBL-resists were tested for protein compatibility. One particular kind (MRL-6000.1XP) supported good actin filament motility, while another (PMMA-950) behaved in the opposite way. Taking advantage of these findings, nm-sized lines were created in a double-layer structure of the two resists. The lines were found to act as binding sites for myosin, and as rectifying guides for the linearized motion of actin filaments. Velocities around 5 mum/s were measured. (C) 2003 Elsevier Science B.V. All rights reserved.
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| 9. |
- Goncalves, Dulce, 1968-, et al.
(författare)
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Cultural aspects of organizational agility affecting digital innovation
- 2020
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Ingår i: Journal of Entrepreneurship, Management, and Innovation. - Nowy Targ : Fundacja Cognitione. - 2299-7075 .- 2299-7326. ; 16:4, s. 13-46
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this study is to understand how the cultural aspects of organizational agility affect digital innovation capability. In the context of increasing demand for fast-paced digital innovation, organizational agility becomes strategically crucial for large incumbent companies to increase their competitiveness. The literature on organizational agility shows that incumbents, with their vast access to resources, still can have limited ability to innovate and respond to change. This is in sharp contrast to startups, who sometimes are impressively innovative despite their very limited resources. Sometimes the incumbents are even outcompeted and disrupted by startups because of their ability to embrace change, and rapidly seize new business opportunities. However, we know little about why some incumbents are not able to use their resources efficiently for digital innovation and why some smaller startups can transcend these resource limitations. In this context, we find that cultural aspects are especially crucial as enablers for organizational agility in digital innovation. We designed a comparative study to investigate the differences in the influence of culture on organizational agility; and how it hinders or enables digital innovation, at both incumbent firms and startups in the automotive industry. We applied a qualitative research approach and selected semi-structured interviews as our main research method. The Competing Values Framework was used as a tool to categorize different cultures that affect organizational agility, but also to identify how and when tensions between values supported or hampered the organizations’ ability to innovate. Our findings show that, while a blend of Hierarchy and Market cultures inhibited the innovation capability, Clan and Adhocracy cultures promoted innovation. In our sample, the incumbents predominantly adhered to the first two cultures, while the startups typically belonged to the second group. The most successful startups were even able to create a combination of Clan and Adhocracy cultures — a concept we here term ‘Agile culture.’ This culture allowed them to reach a beneficial state of digital innovation growth. When it comes to the implications for research and practice, we found the need to analyze the role of culture for organizational agility; and how to utilize culture as an asset to enable digital innovation growth. One contribution is the identification of ‘Agile culture’ that is an amalgamation of Clan and Adhocracy culture. The value agile culture creates when applied, enables organizational agility, which can enhance digital innovation capability.
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| 10. |
- Haghighi, Mona, et al.
(författare)
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A Comparison of Rule-based Analysis with Regression Methods in Understanding the Risk Factors for Study Withdrawal in a Pediatric Study
- 2016
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Regression models are extensively used in many epidemiological studies to understand the linkage between specific outcomes of interest and their risk factors. However, regression models in general examine the average effects of the risk factors and ignore subgroups with different risk profiles. As a result, interventions are often geared towards the average member of the population, without consideration of the special health needs of different subgroups within the population. This paper demonstrates the value of using rule-based analysis methods that can identify subgroups with heterogeneous risk profiles in a population without imposing assumptions on the subgroups or method. The rules define the risk pattern of subsets of individuals by not only considering the interactions between the risk factors but also their ranges. We compared the rule-based analysis results with the results from a logistic regression model in The Environmental Determinants of Diabetes in the Young (TEDDY) study. Both methods detected a similar suite of risk factors, but the rule-based analysis was superior at detecting multiple interactions between the risk factors that characterize the subgroups. A further investigation of the particular characteristics of each subgroup may detect the special health needs of the subgroup and lead to tailored interventions.
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