18 research outputs found

    Expression of genes for bone morphogenetic proteins BMP-2, BMP-4 and BMP-6 in various parts of the human skeleton

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    BACKGROUND: Differences in duration of bone healing in various parts of the human skeleton are common experience for orthopaedic surgeons. The reason for these differences is not obvious and not clear.METHODS: In this paper we decided to measure by the use of real-time RT-PCR technique the level of expression of genes for some isoforms of bone morphogenetic proteins (BMPs), whose role is proven in bone formation, bone induction and bone turnover. Seven bone samples recovered from various parts of skeletons from six cadavers of young healthy men who died in traffic accidents were collected. Activity of genes for BMP-2, -4 and -6 was measured by the use of fluorescent SYBR Green I.RESULTS: It was found that expression of m-RNA for BMP-2 and BMP-4 is higher in trabecular bone in epiphyses of long bones, cranial flat bones and corpus mandibulae then in the compact bone of diaphyses of long bones. In all samples examined the expression of m-RNA for BMP-4 was higher than for BMP-2.CONCLUSION: It was shown that m-RNA for BMP-6 is not expressed in the collected samples at all. It is postulated that differences in the level of activation of genes for BMPs is one of the important factors which determine the differences in duration of bone healing of various parts of the human skeleton.Author has checked copyrightDG 16/11/1

    On the modelling of aerodynamic force coefficients for over-shroud seals of turbine stages

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    This paper presents experimental investigations which made it possible to determine dynamic coefficients of labyrinth over-shroud seal of a model air turbine. The coefficients associate pressure forces with turbine rotor displacement, velocity and acceleration respective to turbine casing (linear model) and play important role in analyzing turbine-set dynamics. The obtained results indicated that involving serious errors can be expected in the case of application of the simplification consisting in neglecting inertia coefficients, proposed in the literature. It was simultaneously demonstrated that seals can be also met of weak damping qualities, for which to neglect damping coeffcients is allowable

    How much a geometrical model of a honeycomb seal can be simplied in the CFD calculation

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    This paper presents the influence of geometry simplification on the results obtained in the computational fluid dynamics simulation. The subject of simulation was part of the honeycomb seal located at the inlet to high pressure part of a steam turbine. There were three diferent geometrical models assumed in the calculations. First one was two-dimensional case and two others were three-dimensional, one with the radius of curvature and one without. Numerical simulations were performed for 15 sets of boundary conditions to compare flow characteristics for each geometrical case

    Macro-scale glacitectonic deformations of the Neogene deposits in the Konin lignite open-casts

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    Osady neogeńskie w odkrywkach KWB Konin S.A. są silnie zdeformowane glacitektonicznie. Analizie strukturalnej poddano fałdy i nsunięcia wykształcone w skali makro, których rozmiary dochodzą do kilkuset metrów, a wysokość do kilkudziesięciu metrów. Orientacja tych deformacji wskazuje, że powstały one w czasie kilku zlodowaceń, transgredujących z północy, a wyjątkowo z północnego zachodu.Neogene deposits in the Konin lignite open-casts are strongly deformed due to glaciotectonic processes. Some folds and thrusts were subjected to the structural analysis. Their sizes are reaching up to a few hundred meters and height up to several dozen meters. Orientation of these deformations shows that they came into existence during a few glaciations coming from the north, exceptionally from the north-west

    Design and investigations of the ethanol microturbine

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    The paper presents the results of the design analysis and experimental investigations of the microturbine set consisting of the microturbine with partial admission and permanent magnet generator. The microturbine was designed for operation with the vapour of ethanol as a working fluid. Microturbine unit was tested for different parameters of the working fluid and varying the electrical load. The examples and the comparison between experiment results and numerical simulations are shown and discussed in the paper

    The interplay between deformation and deposition in a Pleistocene push moraine : New insight from structural interpretation and area-depth-strain analysis of the growth strata

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    There are many examples suggesting that push moraine formation requires building up of the proglacial wedge and then post-depositional folding and/or faulting. Only a few studies have been carried out on syntectonic deposition and erosion within proglacial sediment wedges; however, the resulting growth strata were determined based on the high variability in thickness and occurrence of erosional unconformities across the deformed sequence. This study shows how structural interpretation and the area-depth-strain (ADS) balancing method of the growth strata can be applied to better understand the interplay between deformation and deposition within an evolving push moraine primarily composed of a folded sequence of a glaciofluvial fan. This approach, together with analysis of the onlap/overlap relationships, allowed us to determine the relative rate between deposition and deformation. Moreover it provides an insight into the topography of the push moraine that may be inherited not only from the geometry of deformation structures but also from depositional processes controlling the spatial distribution and thickness variation of the growth strata. This study also gives an opportunity to reconstruct the ranges of probable parameters to quantitatively describe the heavily eroded push moraine in terms of the primary topography, height and relative time frame within which it formed. In addition, the probable thermo-hydro-mechanical properties of the deformed strata are interpreted in terms of drained/undrained conditions of volume strain evidenced by structural data and possibilities of lateral flow from beneath synclines into anticlines indicated by ADS-based balancing

    Blue fluorescence of Ti3+ ions in Ti3+-doped, gamma-irradiated SrAl0.5Ta0.5O3:LaAlO3 crystals

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    Titanium-doped SrAl0.5Ta0.5O3: LaAlO3 (SAT:LA) perovskite solid solution single crystals were grown by the Czochralski method for two Ti concentrations: 1 wt.% (LSAT1) and 2 wt.% (LSAT2). It was stated that incorporation of Ti into SAT:LA crystal takes place in a non-uniform way. Ti3+ ions enter the crystal mainly in its conical part and mainly inside a thin (2-3 mm) layer within the crystal boundary. At room temperature, crystals from the conical part of the boule reveal strong absorption centered at about 529 nm for the case of LSAT1 single crystal while at about 451 and 651 nm for the case of LSAT2. Low temperature measurements have shown two absorption peaks centered at about 489 and 562 nm. Moreover, the 850 nm peak is clearly observed. The intensity of the above described absorption coefficient strongly depends on the dopant concentration and reaches even 80 cm-1. The above bands seem to be connected with non emitting Ti3+ centers. After g-irradiation, additional absorption is observed peaked at about 423 nm which gives two emission bands placed near 400 and 800 nm (375 nm excitation wavelength). They seem to be Ti3+ emissions coming from Ti3+ ions, occupying two different lattice octahedral positions one of which being octahedral (Al, Ta) site. Blue fluorescence is self-evident

    Fluvastatin increases tyrosinase synthesis induced by UVB irradiation of B16F10 melanoma cells.

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    Statins are widely used to lower plasma concentrations of lipids, e.g. cholesterol. One of the main effects of statin treatment is inhibition of hydroxymethyl glutaryl-coenzyme A reductase. The role of fluvastatin, a frequently used statin, was examined in potential modulation of tyrosinase (key enzyme of melanogenesis) synthesis. Levels of tyrosinase mRNA induced by UVB irradiation of B16F10 melanoma cell line were measured by real time PCR. Fluvastatin increases tyrosinase mRNA production induced by UVB irradiation in B16F10 melanoma cell line. Fluvastatin treatment may potentially influence melanin synthesis and protection against UV irradiation
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