262 research outputs found
Genetic Variability in Different Lucerne (\u3cem\u3eMedicago Sativa\u3c/em\u3e) Genotypes
One of the basic goals of modern lucerne breeding programmes is creation of new cultivars with a great potential for high quality and stable yields of both forage and hay (Riday & Brummer, 2002). Such cultivars meet increased needs of animal husbandry and must contribute to diverse farming systems (Luki , 2000). Our trial was aimed at determining genetic variability of yield components in 7 lucerne genotypes, as well as at evaluation of their breeding potential as gene donors to new lucerne cultivar
Optical properties of plastically deformed copper
Pure copper (99.99), prepared in the sample of square cross-section (10 x 10 mm2) and length about 50 mm, was extremely plastically deformed with the repeated application of Equal Channel Angular Pressing (ECAP). ECAP was applied as an effective technique for producing bulk nano-scaled structures. Optical properties of the sample were investigated using Raman spectroscopy. Two types of lines: narrow (with width of 7 cm¡1) and wide ( 40 cm¡1) are registered. Existence of two types of lines indicates that in the specimen exists nano-sized crystal structures of both Cu and CuO related with three dimensional amorphous boundary spaces, which indicates that plastic deformation of the sample did not lead to total amorphisation of the specimen
Raman spectroscopy of pharmacologically active compounds and biocatalysts
U ovoj disertaciji Ramanova spektroskopija korišćena je za sveobuhvatnu analizu primarnih mezenhimskih matičnih ćelija, poreklom iz periodoncijuma, mekog vezivnog tkiva koje spaja koren zuba za alveolarnu kost i ima ulogu u održavanju mineralizacije i ublažavaanja sila koje se javljaju žvakanjem...In this dissertation, the utilization of Raman spectroscopy for comprehensive
analysis of primary mesenchymal stem cells from periodontal ligament, a soft connective
tissue which anchors tooth root for the alveolar bone, was demonstrated.
Since every cell has the unique Raman spectrum, Raman spectroscopy was used
with the purpose to gain the insight in intrinsic biochemical prole on a single cell
level. Mesenchymal stem cells from periodontal ligament were stimulated to dierentiate
towards osteogenic, chondrogenic, and adipogenic lineages. These dierentiated
cells were investigated by means of Raman spectroscopy as well. Microscopic
glass cover-slips were used as substrates due to its cost-eectiveness and common
use in laboratories, which is important for its clinical application. On the other
hand, glass has strong Raman response, but it was demonstrated that the analysis
was possible by taking into account certain spectral region in which its inuence was
eliminated. In all sample groups, the same type of behavior was noticed, manifested
as the increase of relative intensity Raman band of proteins/lipids, and the decrease
of relative intensity of nucleic acids Raman bands. Further, the extensive statistical
analysis in the form of principal component analysis was performed, revealing signi-
cant groupings of cells with the same spectral features, which conrmed previously
obtained results. Despite the heterogeneity of primary mesenchymal stem cells and
their dierentiated lineages, it was proved that micro-Raman spectroscopy could
adequately distinguish cell status, which is important for its clinical and medical
use..
Study of barium bismuth titanate prepared by mechanochemical synthesis
Barium-bismuth titanate, BaBi4Ti4O15 (BBT), a member of Aurivillius bismuth-based layer-structure perovskites, was prepared from stoichiometric amounts of barium titanate and bismuth titanate obtained via mechanochemical synthesis. Mechanochemical synthesis was performed in air atmosphere in a planetary ball mill. The reaction mechanism of BaBi4Ti4O15 and the preparation and characteristics of BBT ceramic powders were studied using XRD, Raman spectroscopy, particle analysis and SEM. The Bi-layered perovskite structure of BaBi4Ti4O15 ceramic forms at 1100 °C for 4 h without a pre-calcination step. The microstructure of BaBi4Ti4O15 exhibits plate-like grains typical for the Bi-layered structured material and spherical and polygonal grains. The Ba2+ addition leads to changes in the microstructure development, particularly in the change of the average grain size
The Effect of Liquid-Phase Exfoliated Graphene Film on Neurodifferentiation of Stem Cells from Apical Papilla
Background: Dental stem cells, which originate from the neural crest, due to their easy accessibility might be good candidates in neuro-regenerative procedures, along with graphene-based nanomaterials shown to promote neurogenesis in vitro. We aimed to explore the potential of liquid-phase exfoliated graphene (LPEG) film to stimulate the neuro-differentiation of stem cells from apical papilla (SCAP). Methods: The experimental procedure was structured as follows: (1) fabrication of graphene film; (2) isolation, cultivation and SCAP stemness characterization by flowcytometry, multilineage differentiation (osteo, chondro and adipo) and quantitative PCR (qPCR); (3) SCAP neuro-induction by cultivation on polyethylene terephthalate (PET) coated with graphene film; (4) evaluation of neural differentiation by means of several microscopy techniques (light, confocal, atomic force and scanning electron microscopy), followed by neural marker gene expression analysis using qPCR. Results: SCAP demonstrated exceptional stemness, as judged by mesenchymal markers’ expression (CD73, CD90 and CD105), and by multilineage differentiation capacity (osteo, chondro and adipo-differentiation). Neuro-induction of SCAP grown on PET coated with graphene film resulted in neuron-like cellular phenotype observed under different microscopes. This was corroborated by the high gene expression of all examined key neuronal markers (Ngn2, NF-M, Nestin, MAP2, MASH1). Conclusions: The ability of SCAPs to differentiate toward neural lineages was markedly enhanced by graphene film
Quantification of aluminum-induced changes in wheat root architecture by X-ray microcomputed tomography
Root architectural traits are of fundamental importance for plant performance, especially under unfavorable soil conditions. This study examined the effect of aluminum (Al) toxicity in different growing media (nutrient solutions and soil) on root architecture of two wheat (Triticum aestivum L.) cultivars with different Al tolerances. Seedlings were grown in acidic and limed soil and in two contrasting nutrient solutions. Root systems of soil-grown plants were scanned using x-ray microcomputed tomography (µCT) while that of nutrient solution–grown plants were assesses using WinRhizo, 3 and 5 days after planting (DAP), respectively. Aluminum caused significant reduction of all examined root traits (number of seminal roots, root length, length of the longest seminal root, root surface area, and root volume). Growth in acidic soil caused significant reduction in root length, length of the longest seminal root, and root surface area at 5 DAP. Soil-grown plants produced a larger root system compared to plants grown in nutrient solutions. Aluminum toxicity–induced differences of root traits were also found between different nutrient solutions. Beside the well-known reduction of root length, Al toxicity had a profound effect on other root architectural traits. X-ray µCT has revealed root architectural changes under specific conditions of acidic, Al-toxic soil. Differences obtained in Al-induced effects on root architecture between different nutrient solutions as well as between different growing systems emphasize the need for further study of root architecture, especially under specific conditions of Al toxicity in acidic soils
Competition of disorder and electron-phonon coupling in 2H-TaSeS () as evidenced by Raman spectroscopy
The vibrational properties of 2H-TaSeS () single
crystals were probed using Raman spectroscopy and density functional theory
calculations. The end members revealed two out of four symmetry-predicted Raman
active modes, together with the pronounced two-phonon structure, attributable
to the enhanced electron-phonon coupling. Additional peaks become observable
due to crystallographic disorder for the doped samples. The evolution of the
E mode Fano parameter reveals that the disorder has weak impact on
electron-phonon coupling, which is also supported by the persistence of
two-phonon structure in doped samples. As such, this research provides thorough
insights into the lattice properties, the effects of crystallographic disorder
on Raman spectra, and the interplay of this disorder with the electron-phonon
coupling in 2H-TaSeS compounds
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