819 research outputs found

    Sylkirauhasen tÀhystys sylkirauhassairauksissa

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    TiivistelmĂ€. TĂ€ssĂ€ tutkielmassa tarkastellaan retrospektiivisesti Oulun yliopistollisessa sairaalassa (OYS) 2016–2017 tehtyjĂ€ sylkirauhasten tĂ€hystystoimenpiteitĂ€ (sialendoskopia) eri sylkirauhassairauksissa. Tutkielman tavoitteena on selvittÀÀ, hyötyivĂ€tkö potilaat sylkirauhasten tĂ€hystyksistĂ€. Erityisesti tarkastellaan sitĂ€, vĂ€hensikö leuanalussylkirauhasen tĂ€hystys kyseisen rauhasen poiston tarvetta. Tuloksia vertaillaan OYS:ssa vuonna 2003–2004 tehtyihin sylkikivien poistotoimenpiteisiin ja leuanalussylkirauhasten poistoihin. IhmisellĂ€ on kolme parillista, suurta sylkirauhasta: korvasylkirauhaset, leuanalussylkirauhaset sekĂ€ kielenalussylkirauhaset. Tavallisimmat sylkirauhassairaudet ovat sylkirauhasen tiehyen tukoksesta tai ahtaudesta johtuvia. Tukos tai ahtauma oireilee yleensĂ€ kivuliaana sylkirauhasen turpoamisena ja voi pahimmillaan johtaa bakteerin aiheuttamaan akuuttiin sylkirauhasen tulehdukseen. Yleisin tukoksen aiheuttaja on sylkikivi, joita esiintyy tavallisimmin leuanalussylkirauhasten tiehyissĂ€. Kroonisia, ei-bakteerin aiheuttamia tulehduksia esiintyy yleisimmin korvasylkirauhasissa. Tulehduksen syyt ovat moninaiset, mutta tarkkaa sairauden syntymekanismia ei tunneta. Sylkirauhasen tĂ€hystys on verrattain uusi toimenpide ja OYS:iin se on otettu osaksi toimenpiteiden valikoimaa 2010-luvulla. Toimenpide voi olla sekĂ€ diagnostinen ettĂ€ hoidollinen. TĂ€hystys tehdÀÀn tavallisesti paikallispuudutuksessa. TĂ€hystimen kautta voidaan poistaa sylkikiviĂ€ esimerkiksi pienten korien avulla, laajentaa tiehyttĂ€ sekĂ€ huuhdella tiehyttĂ€ kortisonilla. LisĂ€ksi tĂ€hystyksen yhteydessĂ€ voidaan tehdĂ€ muita toimenpiteitĂ€, kuten sylkikivien poistoja limakalvolle tehdyistĂ€ viilloista. Toimenpiteeseen liittyy harvemmin hĂ€iriöitĂ€, mutta yleisin tĂ€hystyksen jĂ€lkeen ilmaantuva komplikaatio on akuutti bakteerin aiheuttama tulehdus. TĂ€ssĂ€ tutkimuksessa todettiin suurimman osan potilaista hyötyvĂ€n ensimmĂ€isestĂ€ tĂ€hystyskerrasta. Suurin osa tĂ€hystyksistĂ€ ja tĂ€hystysavusteisista toimenpiteistĂ€ tehtiin paikallispuudutuksessa. Sylkikivitaudin hoidossa leuanalussylkirauhasen tĂ€hystys vĂ€hensi rauhasen poiston tarvetta vertailuryhmÀÀn nĂ€hden. Kaiken kaikkiaan leuanalussylkirauhasen tĂ€hystys vĂ€hensi rauhasen poiston tarvetta 60 % jos kaikki potilaat olisi hoidettu leuanalussylkirauhasen poistolla. Korvasylkirauhasen tĂ€hystyksestĂ€ oli yleensĂ€ hyötyĂ€ viimeistÀÀn toisen tĂ€hystyskerran jĂ€lkeen. Lapset hyötyivĂ€t korvasylkirauhasten tĂ€hystyksestĂ€ ensimmĂ€isen kerran jĂ€lkeen. Sylkirauhasten tĂ€hystysten mÀÀrĂ€ OYS:ssa on nousussa. TĂ€llĂ€ hetkellĂ€ tĂ€hystys tehdÀÀn vielĂ€ leikkaussaliolosuhteissa, mutta tutkielman tulosten perusteella voitaisiin harkita myös poliklinikalla tehtĂ€vĂ€n tĂ€hystyksen kĂ€yttöönottamista. NĂ€in voitaisiin mahdollisesti tehdĂ€ taloudellisia sÀÀstöjĂ€ toimenpidekustannuksissa. Kuitenkin lisĂ€tutkimusta tĂ€mĂ€n muutoksen kustannusvaikutuksista tulee vielĂ€ tehdĂ€

    Experimental and numerical investigations of flow structure and momentum transport in a turbulent buoyancy-driven flow inside a tilted tube.

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    Buoyancy-driven turbulent mixing of fluids of slightly different densities [At = Δρ/(2ă€ˆÏă€‰) = 1.15×10−2] in a long circular tube tilted at an angle Ξ = 15° from the vertical is studied at the local scale, both experimentally from particle image velocimetry and laser induced fluorescence measurements in the vertical diametrical plane and numerically throughout the tube using direct numerical simulation. In a given cross section of the tube, the axial mean velocity and the mean concentration both vary linearly with the crosswise distance z from the tube axis in the central 70% of the diameter. A small crosswise velocity component is detected in the measurement plane and is found to result from a four-cell mean secondary flow associated with a nonzero streamwise component of the vorticity. In the central region of the tube cross section, the intensities of the three turbulent velocity fluctuations are found to be strongly different, that of the streamwise fluctuation being more than twice larger than that of the spanwise fluctuation which itself is about 50% larger than that of the crosswise fluctuation. This marked anisotropy indicates that the turbulent structure is close to that observed in homogeneous turbulent shear flows. Still in the central region, the turbulent shear stress dominates over the viscous stress and reaches a maximum on the tube axis. Its crosswise variation is approximately accounted for by a mixing length whose value is about one-tenth of the tube diameter. The momentum exchange in the core of the cross section takes place between its lower and higher density parts and there is no net momentum exchange between the core and the near-wall regions. A sizable part of this transfer is due both to the mean secondary flow and to the spanwise turbulent shear stress. Near-wall regions located beyond the location of the extrema of the axial velocity (|z|≳0.36 d) are dominated by viscous stresses which transfer momentum toward (from) the wall near the top (bottom) of the tube

    Yukawa potentials in systems with partial periodic boundary conditions I : Ewald sums for quasi-two dimensional systems

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    Yukawa potentials are often used as effective potentials for systems as colloids, plasmas, etc. When the Debye screening length is large, the Yukawa potential tends to the non-screened Coulomb potential ; in this small screening limit, or Coulomb limit, the potential is long ranged. As it is well known in computer simulation, a simple truncation of the long ranged potential and the minimum image convention are insufficient to obtain accurate numerical data on systems. The Ewald method for bulk systems, i.e. with periodic boundary conditions in all three directions of the space, has already been derived for Yukawa potential [cf. Y., Rosenfeld, {\it Mol. Phys.}, \bm{88}, 1357, (1996) and G., Salin and J.-M., Caillol, {\it J. Chem. Phys.}, \bm{113}, 10459, (2000)], but for systems with partial periodic boundary conditions, the Ewald sums have only recently been obtained [M., Mazars, {\it J. Chem. Phys.}, {\bf 126}, 056101 (2007)]. In this paper, we provide a closed derivation of the Ewald sums for Yukawa potentials in systems with periodic boundary conditions in only two directions and for any value of the Debye length. A special attention is paid to the Coulomb limit and its relation with the electroneutrality of systems.Comment: 40 pages, 5 figures and 4 table

    OSALLISTUMISESTA TOIMINTAAN : MENETELMÄLLISIÄ RATKAISUJA KAUPUNKIKEHITTÄMISEEN

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    Kunnan viranomaisilla on yhteiskehittÀmisessÀ kaksoisrooli, kun he toimivat sekÀ palvelujen kehittÀjinÀ ettÀ lÀhidemokratian edistÀjinÀ. Arkitodellisuudessa asukkailla ei ole tasavertaista mahdollisuutta ja keinoja vaikuttaa pÀÀtöksentekoon ja palvelujen kehittÀmiseen. Osallistuvassa toimintatutkimuksessa asukkaat ja kunnan toimijat kasvavat yhteisen prosessin myötÀ muutosagenteiksi, jotka analysoivat yhdessÀ alueen ongelmia ja kehittÀvÀt sosiaalisia innovaatioita. Laurea on toteuttanut kaksi osallistavan toimintatutkimuksen hanketta (VÀlittÀvÀt Valittavat Verkostot, Sun Idea) yhteistyössÀ Espoon kaupungin kanssa, joissa on kehitetty ruohonjuuritason menetelmiÀ asukkaiden osallisuuden edistÀmiseksi. Kokeiluihin on osallistunut sadoittain asukkaita erilaisissa rooleissa ja osa niistÀ on vakiinnutettu pysyviksi toimintatavoiksi. TÀssÀ artikkelissa kuvataan kolmea erilaista yhteiskehittÀmisen kokeilua Espoon keskuksen alueella. Tuloksellinen yhteiskehittÀminen edellyttÀÀ pitkÀkestoista kanssakÀymistÀ eri toimijoiden kanssa ja sitkeÀÀ jalkatyötÀ asukkaiden keskuudessa. Avainsanat: yhteiskehittÀminen, sosiaalinen innovaatio, osallistuva toimintatutkimu

    Processing of the papain precursor. Purification of the zymogen and characterization of its mechanism of processing.

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    The precursor of the cysteine protease papain has been expressed and secreted as propapain from insect cells infected with a recombinant baculovirus expressing a synthetic gene coding for prepropapain. This 39-kDa secreted propapain zymogen molecule is glycosylated and can be processed in vitro into an enzymatically active authentic papain molecule of 24.5 kDa (Vernet, T., Tessier, D.C., Richardson, C., Laliberte, F., Khouri, H. E., Bell, A. W., Storer, A. C., and Thomas, D. Y. (1990) J. Biol. Chem. 265, 16661-16666). Recombinant propapain was stabilized with Hg2+ and purified to homogeneity using affinity chromatography, gel filtration, and ion-exchange chromatographic procedures. The maximum rate of processing in vitro was achieved at approximately pH 4.0, at a temperature of 65 degrees C and under reducing conditions. Precursor processing is inhibited by a variety of reversible and irreversible cysteine protease inhibitors but not by specific inhibitors of serine, metallo or acid proteases. Replacement by site-directed mutagenesis of the active site cysteine with a serine at position 25 also prevents processing. The inhibitor 125I-N-(2S,3S)-3-trans-hydroxycarbonyloxiran-2-carbonyl-L-tyrosine benzyl ester covalently labeled the wild type papain precursor, but not the C25S mutant, indicating that the active site is accessible to the inhibitor and is in a native conformation within the precursor. Based on biochemical and kinetic analyses of the activation and processing of propapain we have shown that the papain precursor is capable of autoproteolytic cleavage (intramolecular). Once free papain is released processing can then occur in trans (intermolecular)

    Age and geochemistry of granitoids in the Precambrian basement of Öland, SE Sweden – implications for the extension of the Transscandinavian Igneous Belt in the Baltic Sea region

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    The Precambrian crust in the Baltic Sea region is mostly covered by Phanerozoic sedimentary rocks but can be studied in drill cores. Two granitoids from the crystalline basement below Öland were collected from the archives of the Geological Survey of Sweden and analyzed for geochemistry and dated with the U-Pb method on zircons. The Böda Hamn granitoid (northern Öland) has a monzodioritic composition and an age of 1799.8±3 Ma while the ValsnĂ€s granitoid (central Öland) has a quartz monzonitic composition and an age of 1784.9±5.7 Ma. These geochemical-isotopic characteristics are compatible with those of generation 1 of the Transscandinavian Igneous Belt (TIB) in the Fennoscandian Shield, ≄30 km west of Öland.A more detailed review of the TIB-1 generation shows that two sub-generations (1a and 1b) can be distinguished on each respective side of the Oskarshamn-Jönköping Belt (OJB). Sub-generation 1a (north of OJB) has an age span of 1794-1808 Ma while sub-generation 1b (south of OJB) has an age span of 1769-1793 Ma. According to this subdivision, the Böda Hamn monzodiorite belongs to sub-generation 1a, which also can be followed to southernmost Gotland (Sundblad et al. 2003) and the ValsnĂ€s quartz monzonite belongs to sub-generation 1b, which can be followed to the Latvian/Lithuanian border, where a marginally younger granitoid was reported from off shore drill core E-7 (Salin et al. 2016). Taken together, these data suggest that the Transscandinavian Igneous Belt can be traced across the Baltic Sea from the exposed parts within the Fennoscandian Shield to the Latvian/Lithuanian border.Salin, E., Sundblad, K., Woodard, J. and Lahaye, Y. 2016: The Precambrian crust in the Baltic Sea region. Bulletin of the Geological Society of Finland, 32nd Nordic Geological Winter Meeting, Helsinki. Abstract volume, p. 162.Sundblad, K., Claesson, S. & Gyllencreutz, R. 2003: The Precambrian of Gotland – a key to the understanding of the geologic environment for granitoids in the Baltic Sea region. Granitic systems – State of the art and future avenues. An international symposium in honor of professor Ilmari Haapala. Abstract volume, Helsinki, 102­–106. </p

    Wave Number of Maximal Growth in Viscous Magnetic Fluids of Arbitrary Depth

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    An analytical method within the frame of linear stability theory is presented for the normal field instability in magnetic fluids. It allows to calculate the maximal growth rate and the corresponding wave number for any combination of thickness and viscosity of the fluid. Applying this method to magnetic fluids of finite depth, these results are quantitatively compared to the wave number of the transient pattern observed experimentally after a jump--like increase of the field. The wave number grows linearly with increasing induction where the theoretical and the experimental data agree well. Thereby a long-standing controversy about the behaviour of the wave number above the critical magnetic field is tackled.Comment: 19 pages, 15 figures, RevTex; revised version with a new figure and references added. submitted to Phys Rev

    Nonlinear interaction of charged particles with a free electron gas beyond the random-phase approximation

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    A nonlinear description of the interaction of charged particles penetrating a solid has become of basic importance in the interpretation of a variety of physical phenomena. Here we develop a many-body theoretical approach to the quadratic decay rate, energy loss, and wake potential of charged particles moving in an interacting free electron gas. Explicit expressions for these quantities are obtained either within the random-phase approximation (RPA) or with full inclusion of short-range exchange and correlation effects. The Z^3 correction to the energy loss of ions is evaluated beyond RPA, in the limit of low velocities.Comment: 5 pages, 2 figures To appear in Phys. Rev.
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