77 research outputs found

    Concentration and localization of zinc during seed development and germination in wheat

    Get PDF
    In a field experiment, the effect of foliar Zn applications on the concentration of Zn in seeds of a bread wheat cultivar (Triticum aestivum L. cv. Balatilla) was studied during different stages of seed development. In addition, a staining method using dithizone (DTZ: diphenyl thiocarbazone) was applied to (1) study the localization of Zn in seeds, (2) follow the remobilization of Zn during germination, and (3) develop a rapid visual Zn screening method for seed and flour samples. In all seed development stages, foliar Zn treatments were effective in increasing seed Zn concentration. The highest Zn concentration in the seeds was found in the first stage of seed development (around the early milk stage); after this, seed Zn concentration gradually decreased until maturity. When reacting with Zn, DTZ forms a redcolored complex. The DTZ staining of seed samples revealed that Zn is predominantly located in the embryo and aleurone parts of the seeds. After 36 h of germination, the coleoptile and roots that emerged from seeds showed very intensive red color formation and had Zn concentrations up to 200 mg kg1, indicating a substantial remobilization of Zn from seed pools into the developing roots (radicle) and coleoptile. The DTZ staining method seems to be useful in ranking flour samples for their Zn concentrations. There was a close relationship between the seed Zn concentrations and spectral absorbance of the methanol extracts of the flour samples stained with DTZ. The results suggest that (1) accumulation of Zn in seeds is particularly high during early seed development, (2) Zn is concentrated in the embryo and aleurone parts, and (3) the DTZ staining method can be used as a rapid, semiquantitative method to estimate Zn concentrations of flour and seed samples and to screen genotypes for their Zn concentrations in seeds

    Comparison of phase structures and surface free energy values for the coatings synthesised from linear polyurethanes and from waterborne polyurethane cationomers

    Get PDF
    WAXS, DSC and AFM methods were employed to compare phase structures of the coatings obtained from waterborne polyurethane cationomers which had been synthesised in the reaction of some diisocyanates (MDI, IPDI, TDI and HDI) with polyoxyethylene glycols (M = 600 and 2,000) and butane1,4-diol or N-methyl- or N-butyldiethanolamine and 2,2,3,3-tetrafluoro-1,4-butanediol. The structures were also analysed of the coatings derived from linear polyurethanes which had been synthesised on the basis of similar raw materials. Better rigidity was found for generally amorphous cationomer coats. Changes were discussed in the surface free energy (SFE) values and in their components, as calculated independently with the use of the van Oss–Good and Owens–Wendt methods. Polyurethane coats turned out more hydrophobic as compared to cationomer ones. In both coat types, fluorine incorporated into cationomers contributed to lower SFE values: from 50 down to about 30 mJ/m2

    Inspiracja rynkowa transferu technologii w badaniach nad uprawą ziemniaka

    No full text
    Zintegrowany system zarządzania jest podstawowym narzędziem informatycznym wspierającym i koordynującym różne dyscypliny naukowe. Systemy informatyczne zbliżają rynek producentów do konsumenta. Transfer technologii w zakresie pierwiastków śladowych wspomagany zintegrowanym systemem informatycznym może zapewnić oczekiwania rynku z zakresu bezpiecznego produktu. Kapitał ludzki w połączeniu z wiedzą interdyscyplinarną wzbogaca kulturę organizacyjną przedsiębiorstwa. Kapitał strukturalny w postaci sprzętu komputerowego, oprogramowania, bazy danych, struktur organizacyjnych patentów wzbogaca relacje z klientami.The management information systems are the basic informatic tools which support and co-ordinate different kinds of knowledge. These systems enable a better contact of the enterprises with the customers. Technology transfer in a range of trace elements aided by information systems can enssure the marketing of safety products. Human capital together with different kinds of knowledge enriches the organizational culture of the enterprise. Structural capital such as, for example, computers, software, data bases, organizational structure, patents enriches the relations with customers

    Synthesis and characterization of polyurethane-based biomaterials modified with chitosan and hydroxyapatite

    No full text

    Alginate-based hydrogels modified with graphene oxide and hydroxyapatite for cartilage tissue regeneration

    No full text

    Modification of PLGA microspheres’ microstructure for application as cell carriers in modular tissue engineering

    No full text
    Microspheres (MS) made of resorbable polymer have been proposed as a cell growth support. They may be assembled to form cell constructs or be suspended in hydrogels allowing injection into injury location. High relative surface area of MS provides more efficient cell culture environment than traditional culture on flat substrates (multiwell plates, Petri dishes). In addition, MS structure, topography and surface chemistry can be modified to promote cell adhesion and proliferation. The aim of this study was to obtain resorbable poly(L-lactide-co-glycolide) (PLGA) MS and to modify their properties by changing manufacturing conditions of the oil-in-water emulsification to better control structural and microstructural properties of MS and their biological performance. To this end, water phase was modified by addition of NaCl to change ionic strength, while oil phase by addition of polyethylene glycol (PEG). Microstructural and thermal properties were assessed. Cytocompatibility tests and cell cultures with MG-63 cells were conducted to verify potential relevance of MS as cell carriers. The results showed that it is possible to obtain cytocompatible MS by oil-in-water emulsification method and to control diameter, porosity and crystallinity of MS with the use of additives to oil and/or water phases without negative changes in MS cytocompatibility. The results prove that modification of both phases make it possible to produce MS with desired/controllable properties like surface topography, porosity and crystallinity

    The effect of functionalized HAp addition on the selected properties of polyacetal-based composites

    No full text

    Modification of microspheres’ microstructure for application as cell carriers in modular tissue engineering

    No full text
    Microspheres (MS) made of resorbable polymer have been proposed as a cell growth support. They may be assembled to form cell constructs or be suspended in hydrogels allowing injection into injury location. High relative surface area of MS provides more efficient cell culture environment than traditional culture on flat substrates (multiwell plates, Petri dishes). In addition, MS structure, topography and surface chemistry can be modified to promote cell adhesion and proliferation. The aim of this study was to obtain resorbable poly(L-lactide-co-glycolide) (PLGA) MS and to modify their properties by changing manufacturing conditions of the oil-in-water emulsification to better control structural and microstructural properties of MS and their biological performance. To this end, water phase was modified by addition of NaCl to change ionic strength, while oil phase by addition of polyethylene glycol (PEG). Microstructural and thermal properties were assessed. Cytocompatibility tests and cell cultures with MG-63 cells were conducted to verify potential relevance of MS as cell carriers. The results showed that it is possible to obtain cytocompatible MS by oil-in-water emulsification method and to control diameter, porosity and crystallinity of MS with the use of additives to oil and/or water phases without negative changes in MS cytocompatibility. The results prove that modification of both phases make it possible to produce MS with desired/controllable properties like surface topography, porosity and crystallinity
    corecore