| 11. |
- Andreasson, Björn Pererik, 1979-, et al.
(författare)
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Spatial distribution of oxygen vacancies in Cr-doped SrTiO3 during an electric-field-driven insulator-to-metal transition
- 2009
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Ingår i: Applied Physics Letters. - College Park, MD : American Institute of Physics (AIP). - 0003-6951 .- 1077-3118. ; 94:1, s. Article number: 013513-
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Tidskriftsartikel (refereegranskat)abstract
- Spatially resolved x-ray fluorescence maps are presented that show the introduction and the evolution of oxygen vacancies in chromium-doped strontium titanate during an electric-field-driven insulator-to-metal transition. The vacancies are introduced at the anode and diffuse through the crystal toward the cathode. The spatial distribution of vacancies is explained by a model describing the electrical breakdown as a percolation process. Strong differences in the vacancy distribution were found when the transition took place in air and in a hydrogen-enriched atmosphere. In air, the vacancies disappeared from the surface, whereas in the reducing hydrogen atmosphere, they remained at the surface. © 2009 American Institute of Physics.
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| 12. |
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| 13. |
- Andreasson, Joakim, 1973, et al.
(författare)
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A simplicity-guided approach toward molecular set-reset memories
- 2010
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Ingår i: New Journal of Chemistry. - : Royal Society of Chemistry (RSC). - 1369-9261 .- 1144-0546. ; 34:12, s. 2701-2703
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Tidskriftsartikel (refereegranskat)abstract
- Photochromic switches fulfill the general molecular design criteria for the surprisingly straightforward small-scale integration of seemingly complex set-reset latches. The implications of this re-interpretation are discussed with the example of a dithienylethene photochrome. The concept is shown to be valid for a multitude of well-introduced bistable switches with clearly differentiated output signals, e.g., optical signals for the presented example.
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| 14. |
- Andreasson, Joakim, 1973, et al.
(författare)
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All-Photonic Multifunctional Molecular Logic Device
- 2011
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Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 1520-5126 .- 0002-7863. ; 133:30, s. 11641-11648
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Tidskriftsartikel (refereegranskat)abstract
- Photochromes are photoswitchable, bistable chromophores which, like transistors, can implement binary logic operations. When several photochromes are combined in one molecule, interactions between them such as energy and electron transfer allow design of simple Boolean logic gates and more complex logic devices with all-photonic inputs and outputs. Selective isomerization of individual photochromes can be achieved using light of different wavelengths, and logic outputs can employ absorption and emission properties at different wavelengths, thus allowing a single molecular species to perform several different functions, even simultaneously. Here, we report a molecule consisting of three linked photochromes that can be configured as AND, XOR, INH, half-adder, half-subtractor, multiplexer, demultiplexer, encoder, decoder, keypad lock, and logically reversible transfer gate logic devices, all with a common initial state. The system demonstrates the advantages of light-responsive molecules as multifunctional, reconfigurable nanoscale logic devices that represent an approach to true molecular information processing units.
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| 15. |
- Andreasson, Joakim, 1973, et al.
(författare)
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Molecules for security measures: From keypad locks to advanced communication protocols
- 2018
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Ingår i: Chemical Society Reviews. - : Royal Society of Chemistry (RSC). - 1460-4744 .- 0306-0012. ; 47:7, s. 2266-2279
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Forskningsöversikt (refereegranskat)abstract
- The idea of using molecules in the context of information security has sparked the interest of researchers from many scientific disciplines. This is clearly manifested in the diversity of the molecular platforms and the analytical techniques used for this purpose, some of which we highlight in this Tutorial Review. Moreover, those molecular systems can be used to emulate a broad spectrum of security measures. For a long time, molecular keypad locks enjoyed a clear preference and the review starts off with a description of how these devices developed. In the last few years, however, the field has evolved into something larger. Examples include more complex authentication protocols (multi-factor authentication and one-time passwords), the recognition of erroneous procedures in data transmission (parity devices), as well as steganographic and cryptographic protection.
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| 16. |
- Andreasson, Joakim, 1973, et al.
(författare)
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Molecules with a sense of logic: a progress report
- 2015
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Ingår i: Chemical Society Reviews. - 1460-4744 .- 0306-0012. ; 44:5, s. 1053-1069
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Forskningsöversikt (refereegranskat)abstract
- In this tutorial review, the most recent developments in the field of molecular logic and information processing are discussed. Special emphasis is given to the report of progress in the concatenation of molecular logic devices and switches, the design of memory systems working according to the principles of sequential logic, the mimicking of transistors, and the research on photochromic platforms with an unprecedented degree of functional integration. Furthermore, a series of achievements that add up to the conceptual diversity of molecular logic is introduced, such as the realization of highly complex and logically reversible Toffoli and Fredkin gates by the action of DNAzymes or the use of a multifluorophoric platform as a viable approach towards keypad lock functions.
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| 17. |
- Andreasson, Joakim, 1973, et al.
(författare)
-
Smart molecules at work-mimicking advanced logic operations
- 2010
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Ingår i: Chemical Society Reviews. - : Royal Society of Chemistry (RSC). - 1460-4744 .- 0306-0012. ; 39:1, s. 174-188
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Tidskriftsartikel (refereegranskat)abstract
- Molecular logic is an interdisciplinary research field, which has captured worldwide interest. This tutorial review gives a brief introduction into molecular logic and Boolean algebra. This serves as the basis for a discussion of the state-of-the-art and future challenges in the field. Representative examples from the most recent literature including adders/subtractors, multiplexers/demultiplexers, encoders/decoders, and sequential logic devices (keypad locks) are highlighted. Other horizons, such as the utility of molecular logic in bio-related applications, are discussed as well.
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| 18. |
- Andreasson, Joakim, 1973, et al.
(författare)
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Storage and Processing of Information Using Molecules: The All-Photonic Approach with Simple and Multi-Photochromic Switches
- 2013
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Ingår i: Israel Journal of Chemistry. - : Wiley. - 0021-2148. ; 53:5, s. 236-246
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Forskningsöversikt (refereegranskat)abstract
- The use of photochromes for the implementation of molecular logic operations is a very promising approach toward molecular computing. This statement is based on a) the possibility of operating such molecular devices exclusively with photonic signals and b) spatiotemporally and remotely controlled switching, which is characteristic for photochromes. Herein, a brief overview of the application of simple photochromes and multi-photochromic conjugates for the small-scale functional integration of complicated logic circuits is given. This complements and extends efforts to design molecular photochromic memories for data storage described by many research groups worldwide.
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| 19. |
- Andréasson, Måns, 1994-, et al.
(författare)
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Exploring the dispersion and electrostatic components in arene-arene interactions between ligands and G4 DNA to develop G4-ligands
- 2024
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Ingår i: Journal of Medicinal Chemistry. - : American Chemical Society (ACS). - 0022-2623 .- 1520-4804. ; 67:3, s. 2202-2219
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Tidskriftsartikel (refereegranskat)abstract
- G-Quadruplex (G4) DNA structures are important regulatory elements in central biological processes. Small molecules that selectively bind and stabilize G4 structures have therapeutic potential, and there are currently >1000 known G4 ligands. Despite this, only two G4 ligands ever made it to clinical trials. In this work, we synthesized several heterocyclic G4 ligands and studied their interactions with G4s (e.g., G4s from the c-MYC, c-KIT, and BCL-2 promoters) using biochemical assays. We further studied the effect of selected compounds on cell viability, the effect on the number of G4s in cells, and their pharmacokinetic properties. This identified potent G4 ligands with suitable properties and further revealed that the dispersion component in arene-arene interactions in combination with electron-deficient electrostatics is central for the ligand to bind with the G4 efficiently. The presented design strategy can be applied in the further development of G4-ligands with suitable properties to explore G4s as therapeutic targets.
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| 20. |
- Andreasson, M, et al.
(författare)
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MCEE Mutations in an Adult Patient with Parkinson's Disease, Dementia, Stroke and Elevated Levels of Methylmalonic Acid
- 2019
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Ingår i: International journal of molecular sciences. - : MDPI AG. - 1422-0067. ; 20:11
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Methylmalonic aciduria (MMA-uria) is seen in several inborn errors of metabolism (IEM) affecting intracellular cobalamin pathways. Methylmalonyl-CoA epimerase (MCE) is an enzyme involved in the mitochondrial cobalamin-dependent pathway generating succinyl-CoA. Homozygous mutations in the corresponding MCEE gene have been shown in children to cause MCE deficiency with isolated MMA-uria and a variable clinical phenotype. We describe a 78-year-old man with Parkinson’s disease, dementia and stroke in whom elevated serum levels of methylmalonic acid had been evident for many years. Metabolic work-up revealed intermittent MMA-uria and increased plasma levels of propionyl-carnitine not responsive to treatment with high-dose hydroxycobalamin. Whole genome sequencing was performed, with data analysis targeted towards genes known to cause IEM. Compound heterozygous mutations were identified in the MCEE gene, c.139C>T (p.Arg47X) and c.419delA (p.Lys140fs), of which the latter is novel. To our knowledge, this is the first report of an adult patient with MCEE mutations and MMA-uria, thus adding novel data to the possible phenotypical spectrum of MCE deficiency. Although clinical implications are uncertain, it can be speculated whether intermittent hyperammonemia during episodes of metabolic stress could have precipitated the patient’s ongoing neurodegeneration attributed to Parkinson’s disease.
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