Experimental Demonstration of Spectral Intensity Optical Coherence Tomography

We demonstrate experimentally quantum-inspired, spectral-domain intensity optical coherence tomography. We show that the technique allows for both axial resolution improvement and dispersion cancellation compared to conventional optical coherence tomography. The method does not involve scanning and it works with classical light sources and standard photodetectors. The measurements are in excellent agreement with the theoretical predictions. We also propose an approach that enables the elimination of potential artifacts arising from multiple interfaces

Photolithographic fabrication method of computer-generated holographic interferograms

We consider the fabrication of high-quality interferogram-type diffractive optical elements with conventional photolithographic techniques and compare the results with those achievable with electron-beam lithography. The fringes associated with the phase transfer function of the binary phase holographic interferogram are approximated with rectangles, which can be realized at submicron accuracy using a pattern generator and step-and-repeat camera. The effects of the rectangle quantization are analyzed both numerically and experimentally with the aid of diffraction patterns produced by simple focusing elements. Both resolution and diffraction efficiency of the best holograms approach their theoretical values

Titanium complexes of phosphinimide ligands with pendant hemilabile donars.

Originally published in Optics Express on 23 March 2015 (oe-23-6-7879

On the inclusion of forest exposure pathways into a stylized lake-farm scenario in a geological repository safety analysis

Geological disposal of radioactive waste has been recognized as the ‘reference solution’ to ensure the safety required for the present and future society and environment. To study the possible exposure pathways from groundwater to humans, radioactive transport modelling is used. One of the ecosystems that may play a significant role when assessing the dose conversion factor (i.e. the dose resulting from a nominal release of 1 Bq/year of each radionuclide) for humans is forest. In this paper we have developed a model of a lake-farm system with a forest component. The biosphere system used in this study represents a typical agricultural scenario in Finland, amended with a typical forest. A lake is assumed to form due to post-glacial land uplift. The main features of this future lake have been obtained from our probabilistic shoreline displacement model. Both deterministic calculations and sensitivity analysis were carried out to simulate the model. The deterministic simulation demonstrates the behaviour of the studied radionuclides (36Cl, 135Cs, 129I, 237Np, 90Sr, 99Tc and 238U) and the proportions of different exposure pathways to humans. Particularly for 135Cs and 129I, forest pathways make a notable contribution to the dose conversion factor. The sensitivity analysis was done using two methods: EFAST and Sobol’. With both methods, the parameters related to the farm contribute the most to the variance of the dose conversion factor for humans. The study demonstrates that the exposure pathways related to forest products may make a considerable contribution to the dose conversion factor in a lake–farm–forest system. It is also confirmed that an advanced sensitivity analysis for a radionuclide transport and dose assessment model on such a landscape scale is feasible even with moderate computational efforts.publishedVersionPeer reviewe

High-Q guided-mode resonance of a crossed grating with near-flat dispersion

Guided-mode resonances in diffraction gratings are manifested as peaks (dips) in reflection (transmission) spectra. Smaller resonance line widths (higher Q-factors) ensure stronger light-matter interactions and are beneficial for field-dependent physical processes. However, strong angular and spectral dispersion are inherent to such high-Q resonances. We demonstrate that a class of high-Q resonant modes (Q-factor >1000) exhibiting extraordinarily weak dispersion can be excited in crossed gratings simultaneously with the modes with well-known nearly linear dispersion. Furthermore, we show that the polarization of the incoming light can be adjusted to engineer the dispersion of these modes, and strong to near-flat dispersion or vice-versa can be achieved by switching between two mutually orthogonal linear polarization states. We introduce a semi-analytical model to explain the underlying physics behind these observations and perform full-wave numerical simulations and experiments to support our theoretical conjecture. The results presented here will benefit all applications that rely on resonances in free-space-coupled geometries

Rytmiä ja rakennetta arkeen : Sosiaalista ja ammatillista kuntoutusta yhdistävä nuorten kuntoutuksen kehittämishanke Saku

Saku-kehittämishankkeessa (2018–2020) kehitettiin työ- ja opiskeluelämän ulkopuolella olevien 16–29-vuotiaiden nuorten kuntoutusmallia. Sosiaalista ja ammatillista kuntoutusta joustavasti yhdistämään pyrkivässä ja laajasti muuhun palvelujärjestelmään verkostoituvassa Saku-hankkeessa tavoitteeksi asetettiin yksilö- ja ryhmämuotoisen kuntoutuksen sekä niihin kytkeytyvän etäkuntoutuksen (eSaku) kehittäminen syrjäytyneille ja syrjäytymisvaarassa oleville nuorille. Kohderyhmän nuoret eivät olleet peruskoulun tai toisen asteen opintojen jälkeen kiinnittyneet työelämään tai jatko-opintoihin tai heidän opiskelunsa olivat keskeytyneet. Nuoret ohjautuivat Saku-hankkeeseen etsivän nuorisotyön ja muiden nuorten kanssa toimivien tahojen ohjaamina. Nuoret pääsivät hankkeeseen joustavasti ilman erillisiä diagnostisia selvittelyä ja hakuprosesseja. Hankkeeseen ohjautuvilla nuorilla oletettiin olevan vaikeuksia löytää omia tarpeita, taitoja tai kykyjä vastaava ammatillinen polku. Kaikki halukkaat ikäkriteerit täyttävät nuoret otettiin hankkeeseen mukaan. Hankkeessa oli tavoitteena kehittää lisäksi nuorten kanssa toimivien tahojen paikallinen (Turku ja Oulu) yhteistyömalli hankkeen ajalle ja jatkokäyttöön nuorten tavoittamiseksi ja auttamiseksi. Ennen mahdollisia Kelan ammatillisen kuntoutuksen toimia osa nuorista tarvitsee tavoitteellista tukea elämänhallintansa kohentamiseen, arjen taitojen opetteluun sekä uskalluksensa ja osaamisensa vahvistamiseen. Näitä taitoja tarvitaan, jotta päästään asteittain kohti ammatillisia päämääriä. Tämän takia ammattiin ja työelämään tähtääviä toimenpiteitä ei voida toteuttaa irrallaan sosiaalisen toimintakyvyn kehittämisestä vaan tarvitaan joustavia nuoren ammatillisia päämääriä vahvistavia polkuja, jotka ovat yksilöllisestä tarpeesta käsin modulaarisesti rakentuvia ja vaiheittain eteneviä. Saku-hankkeessa yhdistettiin sosiaalinen- ja ammatillinen kuntoutus yksilöllisesti kunkin nuoren kohdalla. Saku-hankkeessa nuorilla oli myös mahdollisuus osallistua työhön tutustumisjaksoille.nonPeerReviewedVertaisarvioimato

Partially coherent beam generation with metasurfaces

An optical system for the generation of partially coherent beams with genuine cross-spectral density functions from spatially modulated globally incoherent sources is presented. The spatial intensity modulation of the incoherent source is achieved by quasi-planar metasurfaces based on spatial-frequency modulation of binary Bragg surface-relief diffraction gratings. Two types of beams are demonstrated experimentally: (i) azimuthally periodic, radially quasi-periodic beams and (ii) rotationally symmetric Bessel-correlated beams with annular far-zone radiation patterns.Peer reviewe

Immunization with gingipain A hemagglutinin domain of Porphyromonas gingivalis induces IgM antibodies binding to malondialdehyde-acetaldehyde modified low-density lipoprotein

Publisher Copyright: © 2018 Kyrklund et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Treatment of periodontitis has beneficial effects on systemic inflammation markers that relate to progression of atherosclerosis. We aimed to investigate whether immunization with A hemagglutinin domain (Rgp44) of Porphyromonas gingivalis (Pg), a major etiologic agent of periodontitis, would lead to an antibody response cross-reacting with oxidized low-density lipoprotein (OxLDL) and how it would affect the progression of atherosclerosis in low-density lipoprotein receptor-deficient (LDLR-/-) mice. The data revealed a prominent IgM but not IgG response to malondialdehyde-acetaldehyde modified LDL (MAA-LDL) after Rgp44 and Pg immunizations, implying that Rgp44/Pgand MAA adducts may share cross-reactive epitopes that prompt IgM antibody production and consequently confer atheroprotection. A significant negative association was observed between atherosclerotic lesion and plasma IgA to Rgp44 in Rgp44 immunized mice, supporting further the anti-atherogenic effect of Rgp44 immunization. Plasma IgA levels to Rgp44 and to Pg in both Rgp44-and Pg-immunized mice were significantly higher than those in saline control, suggesting that IgA to Rgp44 could be a surrogate marker of immunization in Pg-immunized mice. Distinct antibody responses in plasma IgA levels to MAA-LDL, to Pg lipopolysaccharides (Pg-LPS), and to phosphocholine (PCho) were observed after Rgp44 and Pg immunizations, indicating that different immunogenic components between Rpg44 and Pg may behave differently in regard of their roles in the development of atherosclerosis. Immunization with Rgp44 also displayed atheroprotective features in modulation of plaque size through association with plasma levels of IL-1 alpha whereas whole Pg bacteria achieved through regulation of antiinflammatory cytokine levels of IL-5 and IL-10. The present study may contribute to refining therapeutic approaches aiming to modulate immune responses and inflammatory/antiinflammatory processes in atherosclerosis.Peer reviewe

Effects of Different Blade Angle Distributions on Centrifugal Compressor Performance

A centrifugal compressor with three different shrouded 2D impellers is studied numerically. All impellers have the same dimensions, and they only differ in channel length and geometry. Noticeable differences in efficiency are observed. Two different turbulence models, Chien's k-ε and k-ω SST, are compared. For this case, k-ω SST was found more realistic. The hypothesis that pressure losses in a curved duct and in an impeller passage behave similarly is suggested and found inadequate