| 1. |
- Niemi, MEK, et al.
(författare)
-
- 2021
-
swepub:Mat__t
|
|
| 2. |
- Kanai, M, et al.
(författare)
-
- 2023
-
swepub:Mat__t
|
|
| 3. |
- Chatzikonstantinou, T, et al.
(författare)
-
COVID-19 severity and mortality in patients with CLL: an update of the international ERIC and Campus CLL study
- 2021
-
Ingår i: Leukemia. - : Springer Science and Business Media LLC. - 1476-5551 .- 0887-6924. ; 35:12, s. 3444-3454
-
Tidskriftsartikel (refereegranskat)abstract
- Patients with chronic lymphocytic leukemia (CLL) may be more susceptible to Coronavirus disease 2019 (COVID-19) due to age, disease, and treatment-related immunosuppression. We aimed to assess risk factors of outcome and elucidate the impact of CLL-directed treatments on the course of COVID-19. We conducted a retrospective, international study, collectively including 941 patients with CLL and confirmed COVID-19. Data from the beginning of the pandemic until March 16, 2021, were collected from 91 centers. The risk factors of case fatality rate (CFR), disease severity, and overall survival (OS) were investigated. OS analysis was restricted to patients with severe COVID-19 (definition: hospitalization with need of oxygen or admission into an intensive care unit). CFR in patients with severe COVID-19 was 38.4%. OS was inferior for patients in all treatment categories compared to untreated (p < 0.001). Untreated patients had a lower risk of death (HR = 0.54, 95% CI:0.41–0.72). The risk of death was higher for older patients and those suffering from cardiac failure (HR = 1.03, 95% CI:1.02–1.04; HR = 1.79, 95% CI:1.04–3.07, respectively). Age, CLL-directed treatment, and cardiac failure were significant risk factors of OS. Untreated patients had a better chance of survival than those on treatment or recently treated.
|
|
| 4. |
- Andrearczyk, T., et al.
(författare)
-
Bistability of (Ga,Mn)As Ferromagnetic Nanostructures Due to the Domain Walls Switching
- 2009
-
Ingår i: Acta Physica Polonica A. - 0587-4246. ; 116:5, s. 901-903
-
Konferensbidrag (refereegranskat)abstract
- We designed and investigated four-arm nanostructures, composed of two perpendicularly crossed stripes, fabricated from ferromagnetic (Ga,Mn)As layer by means of electron-beam lithography patterning and chemical etching. The nanostructures exhibit a bistable resistance behavior resulting from two configurations of magnetic domain walls in the central part of the structures. We demonstrate a possibility of switching between two stable resistance states in zero magnetic field by applying a pulse of either weak magnetic field or electric current through the structure.
|
|
| 5. |
- Andrearczyk, T., et al.
(författare)
-
Magneto-Transport Characterization of Four-Arm Nanostructure Based on Ferromagnetic (Ga,Mn)As
- 2008
-
Ingår i: ACTA PHYSICA POLONICA A. - 0587-4246. ; 114:5, s. 1049-1054
-
Konferensbidrag (refereegranskat)abstract
- We report on results of magneto-transport measurements performed on four-arm nanostructure fabricated from p-type ferromagnetic Ga0.92Mn0.08As layer. The results reveal hysteresis-like behaviors of low field magneto resistance. We interpret the magnetoresistance in terms of domain walls, which are expected to be trapped inside the nanostructure at some particular positions and which contribute to the total resistance.
|
|
| 6. |
- Wróbel, P., et al.
(författare)
-
Fabrication of corrugated Ge-doped silica fibers
- 2012
-
Ingår i: Optics Express. - 1094-4087 .- 1094-4087. ; 20:13, s. 14508-14513
-
Tidskriftsartikel (refereegranskat)abstract
- We present a method of fabricating Ge-doped SiO2 fibers with corrugations around their full circumference for a desired length in the longitudinal direction. The procedure comprises three steps: hydrogenation of Ge-doped SiO2 fibers to increase photosensitivity, recording of Bragg gratings with ultraviolet light to achieve modulation of refractive index, and chemical etching. Finite-length, radially corrugated fibers may be used as couplers. Corrugated tapered fibers are used as high energy throughput probes in scanning near-field optical microscopy.
|
|
| 7. |
- Wróbel, P., et al.
(författare)
-
Fabrication of corrugated probes for scanning near-field optical microscopy
- 2011
-
Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. - 9780819486608 ; 8070
-
Konferensbidrag (refereegranskat)abstract
- We present a method of fabricating aperture tapered-fiber metal-coated SNOM probes with a corrugated core surface which assures efficient photon-to-plasmon conversion and thus high energy throughput. High energy throughput allows for a small apex aperture and high resolution. The procedure consists of recording of Bragg grating in the to-be-tapered part of a Ge-doped silica fiber and chemical etching with the Turner method. Bragg gratings are recorded with UV light through nearly sinusoidal phase masks of chosen lattice constants. The refractive index contrast in the Bragg grating differentiates the etch rate of the Ge-doped hydrogenated fiber core in exposed and unexposed parts by about 100 nm/min at room temperature.
|
|
| 8. |
- Wróbel, P., et al.
(författare)
-
Preparation of high energy throughput SNOM probes
- 2011
-
Ingår i: 13th International Conference on Transparent Optical Networks, ICTON 2011, Stockholm, 26-30 June 2011. - 2162-7339. - 9781457708800
-
Konferensbidrag (refereegranskat)abstract
- In this technical note we present technological steps of fabrication of high energy throughput SNOM probes. The core-metal coating interface of probes is corrugated what enhances photon-to-plasmon coupling. A strong evanescent field allows for reduction of aperture diameter, which together with skin depth of metal used for coating decide upon resolution. Probes are made of Ge-doped silica glass fibre, which is hydrogenated to increase its photosensitivity. A Bragg grating is recorded in the cores with UV light diffracted into +1 st/1st diffraction orders on a sinusoidal phase mask. Modulation of the refractive index is connected with different etch rates. Etching with the Turner method is made in aqueous solution of HF acid. A corrugated tapered fibre is then coated with aluminium in a special rotating holder. We present results of this novel multi step technology.
|
|
| 9. |
- Figielski, T, et al.
(författare)
-
Magnetotransport through nanoconstriction in ferromagnetic semiconductor (Ga,Mn)As
- 2003
-
Ingår i: Acta Physica Polonica A ( Proceedings of the XXXII International School on Physics of Semiconducting Compounds, Part 1). - 0587-4246. ; 103:6, s. 525-531
-
Konferensbidrag (refereegranskat)abstract
- We studied narrow (submicron) constrictions in the layers of ferromagnetic semiconductor (Ga, Mn)As. We have demonstrated a contribution of the quantum localization effects to the magnetoresistance of the constricted samples. We have also found a negative contribution of a domain wall trapped in the constriction to the resistance, due presumably to the erasing of the localization effects by the domain wall.
|
|
| 10. |
- Figielski, T., et al.
(författare)
-
Remnant magnetoresistance in ferromagnetic (Ga,Mn)As nanostructures
- 2007
-
Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 90:5
-
Tidskriftsartikel (refereegranskat)abstract
- The authors show a magnetoresistive effect that appears in a lithographically shaped, three-arm nanostructure fabricated from ferromagnetic (Ga,Mn)As layers. The effect, related to a rearrangement of magnetic domain walls between different pairs of arms in the structure, is revealed as a dependence of zero-field resistance on the direction of the previously applied magnetic field. This effect could allow designing devices with unique switching and memory properties.
|
|
| 11. |
- Janik, E., et al.
(författare)
-
ZnTe nanowires grown on GaAs(100) substrates by molecular beam epitaxy
- 2006
-
Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 89:13
-
Tidskriftsartikel (refereegranskat)abstract
- ZnTe nanowires with an average diameter of about 30 nm and lengths above 1 mu m were grown on GaAs(100) substrate by molecular beam epitaxy. The growth process was based on the Au-catalyzed vapor-liquid-solid mechanism. A thin gold layer (3-20 angstrom thick) annealed in high vacuum prior to the nanowire growth was used as a source of catalytic nanoparticles. The nanowires are inclined about 55 degrees to the (100) substrate surface normal. They have a zinc-blende crystal structure and their growth axis is < 111 >.
|
|
| 12. |
|
|
| 13. |
- Stefaniuk, T., et al.
(författare)
-
Plasmonic lenses with long focal lengths
- 2012
-
Ingår i: International Conference on Transparent Optical Networks. - 2162-7339. - 9781467322270
-
Konferensbidrag (refereegranskat)abstract
- We report on recent progress made in the development of plasmonic nanolenses. These lenses exhibit intensity transmittance close to 80%, focal lengths equal to one or more wavelengths, and foci with full-widths at halfmaximum close to the diffraction limit. We consider lenses in the form of (i) a silver layer with no hole on the optical axis and double-sided concentric corrugations, (ii) a silver layer with no hole on the axis and single-sided corrugations, and (iii) a lens composed of several concentric metallic rings and on-axis stop with external layer of transparent dielectric that integrates all elements. Investigations are carried out using the Finite-Difference Time-Domain method and the Transfer Matrix Method. The nanolenses are diffractive optical elements that concentrate radially polarized Laguerre-Gauss illumination as tightly as high-NA refractive optical systems.
|
|
| 14. |
- Wosinski, T., et al.
(författare)
-
Domain-wall contribution to magnetoresistance of a ferromagnetic (Ga,Mn)As layer
- 2007
-
Ingår i: Physica Status Solidi. A, Applied Research. - : Wiley. - 0031-8965. ; 204:2, s. 472-476
-
Tidskriftsartikel (refereegranskat)abstract
- Low-temperature charge-carrier transport in simple magnetoresistive nanodevices, consisted of narrow constrictions of submicron width in the epitaxial layer of a ferromagnetic (Ga,Mn)As semiconductor, has been investigated and correlated with magnetic properties of the layer. The devices containing constrictions; revealed abrupt jumps of a reduced resistance that appeared when the sweeping magnetic field crossed the regions of the coercive field of the layer magnetization. In contrast, the non-constricted reference device displayed abrupt jumps of an enhanced resistance at the same values of magnetic field. We interpret the both features, whose positions on the magnetic-field scale reflect the hysteresis loop of magnetization, as manifestation of domain wall contribution to the (Ga,Mn)As layer resistance. The negative contribution of a domain wall to the resistance in the constricted device results most likely from the suppression of the weak localization effects by a domain wall located at the constriction.
|
|
| 15. |
- Wosinski, T., et al.
(författare)
-
Magnetoresistive memory in ferromagnetic (Ga,Mn)As nanostructures
- 2008
-
Ingår i: Materials Sceince - Poland. - 0137-1339 .- 2083-134X. ; 26:4, s. 1097-1104
-
Konferensbidrag (refereegranskat)abstract
- Magneto-resistive nanostructures have been investigated. The structures were fabricated by electron beam lithography patterning and chemical etching from thin epitaxial layers of the ferromagnetic semiconductor (Ga,Mn)As, in shape of three nanowires joined in one point and forming three-terminal devices, in which an electric current can be driven through any of the three pairs of nanowires. In these devices, a novel magneto-resistive memory effect has been demonstrated, related to a rearrangement of magnetic domain walls between different pairs of nanowires in the device consisting in that its zero-field resistance depends on the direction of previously applied magnetic field. The nanostructures can thus work as two-state devices providing basic elements of nonvolatile memory cells.
|
|
| 16. |
- Wróbel, P., et al.
(författare)
-
Concentrator of magnetic field of light
- 2012
-
Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. - 9780819491152 ; 8423
-
Konferensbidrag (refereegranskat)abstract
- In the recent decade metamaterials with magnetic permeability different than unity and unusual response to the magnetic field of incident light have been intensively explored. Existence of magnetic artificial materials created an interest in a scanning near-field magnetic microscope for studies of magnetic responses of subwavelength elementary cells of those metamaterials. We present a method of measuring magnetic responses of such elementary cells within a wide range of optical frequencies with single probes of two types. The first type probe is made of a tapered silica fiber with radial metal stripes separated by equidistant slits of constant angular width. The second type probe is similar to metal coated, corrugated, tapered fiber apertured SNOM probe, but in this case corrugations are radially oriented. Both types of probes have internal illumination with azimuthally polarized light. In the near-field they concentrate into a subwavelength spot the longitudinal magnetic field component which is much stronger than the perpendicular electric one.
|
|
| 17. |
- Wróbel, P., et al.
(författare)
-
Plasmonic concentrator of magnetic field of light
- 2012
-
Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 112:7
-
Tidskriftsartikel (refereegranskat)abstract
- We propose an efficient concentrator of the magnetic component of evanescent field of light for measuring magnetic responses of nanostructures. It is in the form of a tapered fiber probe, which in its final part has corrugations along the angular dimension and is coated with metal except for the aperture at the tip. Internal, azimuthally polarized illumination is concentrated into a subwavelength spot with a strong longitudinal magnetic component H-z. Within the visual range of wavelengths 400-700 nm, the energy density of H-z is up to 50 times larger than that of the azimuthal electric E-phi one. This dominant H-z contribution may be used for magnetic excitation of elementary cells of metamaterials with a single probe guiding a wide spectrum of generated plasmons.
|
|
| 18. |
- Antosiewicz, Tomasz, 1981, et al.
(författare)
-
Bi-metal coated aperture SNOM probes
- 2011
-
Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. - 9780819486608 ; 8070
-
Konferensbidrag (refereegranskat)abstract
- Aperture probes of scanning near-field optical microscopes (SNOM) offer resolution which is limited by a sum of the aperture diameter at the tip of a tapered waveguide probe and twice the skin depth in metal used for coating. An increase of resolution requires a decrease of the aperture diameter. However, due to low energy throughput of such probes aperture diameters usually are larger than 50 nm. A groove structure at fiber core-metal coating interface for photon-to-plasmon conversion enhances the energy throughput 5-fold for Al coated probes and 30-fold for Au coated probes due to lower losses in the metal. However, gold coated probes have lower resolution, first due to light coupling from the core to plasmons at the outside of the metal coating, and second due to the skin depth being larger than for Al. Here we report on the impact of a metal bilayer of constant thickness for coating aperture SNOM probes. The purpose of the bilayer of two metals of which the outer one is aluminum and the inner is a noble metal is to assure low losses, hence larger transmission. Using body-of-revolution finite-difference time-domain simulations we analyze properties of probes without corrugations to measure the impact of using a metal bilayer and choose an optimum bi-metal configuration. Additionally we investigate how this type of metalization works in the case of grooved probes.
|
|
| 19. |
- Antosiewicz, Tomasz, 1981, et al.
(författare)
-
Magnetic probe for material characterization at optical frequencies
- 2011
-
Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. - 9780819486608 ; 8070
-
Konferensbidrag (refereegranskat)abstract
- Rapid development of novel, functional metamaterials made of purely dielectric, plasmonic, or composite structures which exhibit tunable optical frequency magnetic responses creates a need for new measurement techniques. We propose a method of actively measuring magnetic responses, i.e. magnetic dispersion, of such metamaterials within a wide range of optical frequencies with a single probe by exciting individual elementary cells within a larger matrix. The probe is made of a tapered optical fiber with a radially corrugated metal coating. It concentrates azimuthally polarized light in the near-field below the apex into a subwavelength size focus of the longitudinal magnetic field component. An incident azimuthally polarized beam propagates in the core until it reaches the metal stripes of constant angular width running parallel to the axis. For a broad frequency range light-to-plasmon coupling is assured as the lattice constant changes with the radius due to constant angular width. Bound plasmonic modes in slits between the metal stripes propagate toward the apex where circular currents in stripes and displacement currents in slits generate a strong longitudinal magnetic field. The energy density of the longitudinal magnetic component in the vicinity of the axis is much stronger than that of all the other components combined, what allows for pure magnetic excitation of magnetic resonances rather than by the electric field. The scattered signal is then measured in the far-field and analyzed.
|
|
| 20. |
- Biurrun, Idoia, et al.
(författare)
-
Benchmarking plant diversity of Palaearctic grasslands and other open habitats
- 2021
-
Ingår i: Journal of Vegetation Science. - Oxford : John Wiley & Sons. - 1100-9233 .- 1654-1103. ; 32:4
-
Tidskriftsartikel (refereegranskat)abstract
- Journal of Vegetation Science published by John Wiley & Sons Ltd on behalf of International Association for Vegetation Science.Aims: Understanding fine-grain diversity patterns across large spatial extents is fundamental for macroecological research and biodiversity conservation. Using the GrassPlot database, we provide benchmarks of fine-grain richness values of Palaearctic open habitats for vascular plants, bryophytes, lichens and complete vegetation (i.e., the sum of the former three groups). Location: Palaearctic biogeographic realm. Methods: We used 126,524 plots of eight standard grain sizes from the GrassPlot database: 0.0001, 0.001, 0.01, 0.1, 1, 10, 100 and 1,000 m2 and calculated the mean richness and standard deviations, as well as maximum, minimum, median, and first and third quartiles for each combination of grain size, taxonomic group, biome, region, vegetation type and phytosociological class. Results: Patterns of plant diversity in vegetation types and biomes differ across grain sizes and taxonomic groups. Overall, secondary (mostly semi-natural) grasslands and natural grasslands are the richest vegetation type. The open-access file ”GrassPlot Diversity Benchmarks” and the web tool “GrassPlot Diversity Explorer” are now available online (https://edgg.org/databases/GrasslandDiversityExplorer) and provide more insights into species richness patterns in the Palaearctic open habitats. Conclusions: The GrassPlot Diversity Benchmarks provide high-quality data on species richness in open habitat types across the Palaearctic. These benchmark data can be used in vegetation ecology, macroecology, biodiversity conservation and data quality checking. While the amount of data in the underlying GrassPlot database and their spatial coverage are smaller than in other extensive vegetation-plot databases, species recordings in GrassPlot are on average more complete, making it a valuable complementary data source in macroecology. © 2021 The Authors.
|
|
| 21. |
|
|
| 22. |
|
|
| 23. |
|
|
| 24. |
|
|
| 25. |
- Reed, R. A., et al.
(författare)
-
Anthology of the Development of Radiation Transport Tools as Applied to Single Event Effects
- 2013
-
Ingår i: IEEE Transactions on Nuclear Science. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9499 .- 1558-1578. ; 60:3, s. 1876-1911
-
Tidskriftsartikel (refereegranskat)abstract
- This anthology contains contributions from eleven different groups, each developing and/or applying Monte Carlo-based radiation transport tools to simulate a variety of effects that result from energy transferred to a semiconductor material by a single particle event. The topics span from basic mechanisms for single-particle induced failures to applied tasks like developing websites to predict on-orbit single event failure rates using Monte Carlo radiation transport tools.
|
|
| 26. |
- Wrobel, L., et al.
(författare)
-
Compounds activating VCP D1 ATPase enhance both autophagic and proteasomal neurotoxic protein clearance
- 2022
-
Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 13:1
-
Tidskriftsartikel (refereegranskat)abstract
- Enhancing the removal of aggregate-prone toxic proteins is a rational therapeutic strategy for a number of neurodegenerative diseases, especially Huntington's disease and various spinocerebellar ataxias. Ideally, such approaches should preferentially clear the mutant/misfolded species, while having minimal impact on the stability of wild-type/normally-folded proteins. Furthermore, activation of both ubiquitin-proteasome and autophagy-lysosome routes may be advantageous, as this would allow effective clearance of both monomeric and oligomeric species, the latter which are inaccessible to the proteasome. Here we find that compounds that activate the D1 ATPase activity of VCP/p97 fulfill these requirements. Such effects are seen with small molecule VCP activators like SMER28, which activate autophagosome biogenesis by enhancing interactions of PI3K complex components to increase PI(3)P production, and also accelerate VCP-dependent proteasomal clearance of such substrates. Thus, this mode of VCP activation may be a very attractive target for many neurodegenerative diseases. Several neurodegenerative diseases are characterized by the aggregation of cytoplasmic proteins. Here, the authors demonstrate that the small molecule SMER28 activates VCP, which enhances both autophagic and proteasomal clearance of aggregate-prone proteins.
|
|
| 27. |
- Wróbel, P., et al.
(författare)
-
Optimization of transmission and focusing properties of plasmonic nanolenses
- 2011
-
Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. - 9780819486608 ; 8070
-
Konferensbidrag (refereegranskat)abstract
- We consider two kinds of plasmonic nanolenses which focus radially polarized Laguerre-Gauss beam into subwavelength spot. The first one is free-standing opaque metal layer with concentric grooves on both sides [Phys. Rev. Lett. 102, 183902 (2009)]. The second has slits instead of grooves thus concentric rings have to be integrated with dielectric matrix. Constructive interference of far-field radiation of SPPs scattered on the back side of the lenses gives subwavelength size foci approaching the Rayleigh resolution limit. We investigate transmission and focusing properties of considered metal structures. Choice of appropriate metal such as silver, gold, copper or aluminum strongly affects transmission. Parameters of surface structure determine efficient photon-plasmon coupling and plasmon scattering phenomenon thus influence both transmission and focusing effect. Finally, the choice of dielectric function of surrounding medium gives another degree of freedom to fulfill momentum matching condition for resonant photon-plasmon interaction. In this paper, taking into account the above parameters, we show an optimization procedure, which leads to high transmission, tight focal spot and large focal length of the considered plasmonic nanolenses.
|
|
| 28. |
|
|
