Współczesne środki dydaktyczne i ich zastosowanie w działalności dydaktyczno-muzycznej szkolnictwa ogólnokształcącego

Modern educational measures, such as a computer, a multimedia presentation, interactive boards or the Internet, are more and more popular, or at least they are mentioned more often when introducing the ‘modern school’. However, what is the reality like? Are new technologies every – day reality during music classes or the traditional teaching methods are still ‘number one’ in education? Is the today’s school ready for effacement new innovations? If yes, are the teachers ready for them? The attempt to answer above - mentioned questions has been undertaken. The influence of the modern teaching methods for didactic and musical education for secondary schools based on the latest investigations, which have been performed among 50 teachers who tutor music in the area of the Kuyavian-Pomeranian Voivodeship, has been discussed

MATERIAŁY KULTUR OKSYWSKIEJ I WIELBARSKIEJ POZYSKANE W 2010 ROKU NA STANOWISKU 20 W MIEJSCOWOŚCI MAŁE CZYSTE, POW. CHEŁMIŃSKI, WOJ. KUJAWSKO-POMORSKIE

Zarys treści. Artykuł przedstawia wstępne wyniki badań prowadzone w roku 2010 na cmentarzysku ludności kultur oksywskiej i wielbarskiej w miejscowości Małe Czyste (pow. chełmiński). Na odsłoniętej wówczas powierzchni 301,5 m2, natrafiono na 84 obiekty, w tym jeden szkieletowy grób neolityczny oraz 44 groby ciałopalne. Wśród tych ostatnich, na podstawie wydobytych z nich materiałów źródłowych, wyróżniono jeden należący do kultury łużyckiej, trzy(?) do kultury oksywskiej, 21 do kultury wielbarskiej, osiem można powiązać bądź z kulturą oksywską, bądź wielbarską. Ponadto odkryto jeden obiekt o możliwym charakterze osadowym

A Biometric Model for Mineralization of Type-I Collagen Fibrils

The bone and dentin mainly consist of type-I collagen fibrils mineralized by hydroxyapatite (HAP) nanocrystals. In vitro biomimetic models based on self-assembled collagen fibrils have been widely used in studying the mineralization mechanism of type-I collagen. In this chapter, the protocol we used to build a biomimetic model for the mechanistic study of type-I collagen mineralization is described. Type-I collagen extracted from rat tail tendon or horse tendon is self-assembled into fibrils and mineralized by HAP in vitro. The mineralization process is monitored by cryoTEM in combination with two-dimensional (2D) and three-dimensional (3D) stochastic optical reconstruction microscopy (STORM), which enables in situ and high-resolution visualization of the process

Functional Remineralization of Dentin Lesions Using Polymer-Induced Liquid-Precursor Process

It was hypothesized that applying the polymer-induced liquid-precursor (PILP) system to artificial lesions would result in time-dependent functional remineralization of carious dentin lesions that restores the mechanical properties of demineralized dentin matrix. 140 µm deep artificial caries lesions were remineralized via the PILP process for 7–28 days at 37°C to determine temporal remineralization characteristics. Poly-L-aspartic acid (27 KDa) was used as the polymeric process-directing agent and was added to the remineralization solution at a calcium-to-phosphate ratio of 2.14 (mol/mol). Nanomechanical properties of hydrated artificial lesions had a low reduced elastic modulus (ER = 0.2 GPa) region extending about 70 μm into the lesion, with a sloped region to about 140 μm where values reached normal dentin (18–20 GPa). After 7 days specimens recovered mechanical properties in the sloped region by 51% compared to the artificial lesion. Between 7–14 days, recovery of the outer portion of the lesion continued to a level of about 10 GPa with 74% improvement. 28 days of PILP mineralization resulted in 91% improvement of ER compared to the artificial lesion. These differences were statistically significant as determined from change-point diagrams. Mineral profiles determined by micro x-ray computed tomography were shallower than those determined by nanoindentation, and showed similar changes over time, but full mineral recovery occurred after 14 days in both the outer and sloped portions of the lesion. Scanning electron microscopy and energy dispersive x-ray analysis showed similar morphologies that were distinct from normal dentin with a clear line of demarcation between the outer and sloped portions of the lesion. Transmission electron microscopy and selected area electron diffraction showed that the starting lesions contained some residual mineral in the outer portions, which exhibited poor crystallinity. During remineralization, intrafibrillar mineral increased and crystallinity improved with intrafibrillar mineral exhibiting the orientation found in normal dentin or bone

Multiscale approach including microfibril scale to assess elastic constants of cortical bone based on neural network computation and homogenization method

The complexity and heterogeneity of bone tissue require a multiscale modelling to understand its mechanical behaviour and its remodelling mechanisms. In this paper, a novel multiscale hierarchical approach including microfibril scale based on hybrid neural network computation and homogenisation equations was developed to link nanoscopic and macroscopic scales to estimate the elastic properties of human cortical bone. The multiscale model is divided into three main phases: (i) in step 0, the elastic constants of collagen-water and mineral-water composites are calculated by averaging the upper and lower Hill bounds; (ii) in step 1, the elastic properties of the collagen microfibril are computed using a trained neural network simulation. Finite element (FE) calculation is performed at nanoscopic levels to provide a database to train an in-house neural network program; (iii) in steps 2 to 10 from fibril to continuum cortical bone tissue, homogenisation equations are used to perform the computation at the higher scales. The neural network outputs (elastic properties of the microfibril) are used as inputs for the homogenisation computation to determine the properties of mineralised collagen fibril. The mechanical and geometrical properties of bone constituents (mineral, collagen and cross-links) as well as the porosity were taken in consideration. This paper aims to predict analytically the effective elastic constants of cortical bone by modelling its elastic response at these different scales, ranging from the nanostructural to mesostructural levels. Our findings of the lowest scale's output were well integrated with the other higher levels and serve as inputs for the next higher scale modelling. Good agreement was obtained between our predicted results and literature data.Comment: 2

Mineralisation of soft and hard tissues and the stability of biofluids

Evidence is provided from studies on natural and artificial biofluids that the sequestration of amorphous calcium phosphate by peptides or proteins to form nanocluster complexes is of general importance in the control of physiological calcification. A naturally occurring mixture of osteopontin peptides was shown, by light and neutron scattering, to form calcium phosphate nanoclusters with a core–shell structure. In blood serum and stimulated saliva, an invariant calcium phosphate ion activity product was found which corresponds closely in form and magnitude to the ion activity product observed in solutions of these osteopontin nanoclusters. This suggests that types of nanocluster complexes are present in these biofluids as well as in milk. Precipitation of amorphous calcium phosphate from artificial blood serum, urine and saliva was determined as a function of pH and the concentration of osteopontin or casein phosphopeptides. The position of the boundary between stability and precipitation was found to agree quantitatively with the theory of nanocluster formation. Artificial biofluids were prepared that closely matched their natural counterparts in calcium and phosphate concentrations, pH, saturation, ionic strength and osmolality. Such fluids, stabilised by a low concentration of sequestering phosphopeptides, were found to be highly stable and may have a number of beneficial applications in medicine

Submicron-to-nanoscale structure characterization and organization of crystals in dentin bioapatites

The aim of this research was to ascertain the crystal morphology, and to assess the ultrastructure and texture changes of sound (SD) and caries-affected dentin (CAD) after being restored with Zn-free and Zn-containing amalgam. Dentin surfaces were studied by X-ray diffraction (XRD2), and Transmission Electron Microscopy (TEM) through selected area diffraction (SAED) and bright-field (BF) imaging. Crystals, at the dentin surface, were identified as hydroxyl-apatite with augmented crystallographic maturity, crystallite and grain sizes, and lower microstrain, in CAD dentin after Zn-containing amalgam removal, at 310 plane. This group, at this reflection, achieved lower microstrain than before amalgam placement. Opposed trend was followed at 002 reflection. Texture increased in CAD at both reflections, after the removal of Zn-containing amalgams. Crystallinity increased in SD after amalgam restorations at 002 and 310 reflections. In CAD, crystallinity decreased after amalgam restorations at 002 plane. Block-like and needle-like apatite crystals constituted the bulk of minerals in SD. Needle-like apatite crystals were observed, in CAD surfaces, before and after Zn-free amalgam restorations. Polyhedral and rounded drop-like shaped crystals characterized the CAD surfaces before Zn-containing amalgam placement. After the restoration removal, plate-like polygons and three-dimensional agglomerated crystals were determined. Crystallites, with improved crystallographic orientation, became shorter and thinner in CAD treated with Zn-containing amalgams, thus increasing mineralization and maturity.Project MAT2014-52036-P supported by the Ministry of Economy and Competitiveness (MINECO) and European Regional Development Fund (FEDER) and FIS2013-41821-R