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Now showing items 11-15 of 15
Aufsatz
Yeast gene KTI13 (alias DPH8) operates in the initiation step of diphthamide synthesis on elongation factor 2
(2023-08-08)
In yeast, Elongator-dependent tRNA modifications are regulated by the Kti11•Kti13 dimer and hijacked for cell killing by zymocin, a tRNase ribotoxin. Kti11 (alias Dph3) also controls modification of elongation factor 2 (EF2) with diphthamide, the target for lethal ADP-ribosylation by diphtheria toxin (DT). Diphthamide formation on EF2 involves four biosynthetic steps encoded by the DPH1-DPH7 network and an ill-defined KTI13 function. On further examining the latter gene in yeast, we found that kti13Δ null-mutants ...
Aufsatz
Characterization of films and film-forming solutions of chitosan/thermoplastic rice starch associations: Role of starch oxidation and plasticizer type in the molecular interactions
(2023-09-29)
Polysaccharide films are alternative sources to replace fossil-based compounds. This study aimed to use rice starch modified by gelatinization and oxidation processes. Different properties were observed after blending it with chitosan and polyols, as evaluated on the film-forming solutions by rheology. The interaction between chitosan and oxidized starch appeared higher, as the plasticizers exhibited a low effect on the rheological behavior. Polyols played an essential role in chitosan/gelatinized associations, driven ...
Aufsatz
A General Strategy for Increasing the Air Stability of Phosphines Including Primary Phosphines
(2023-08-31)
A general approach for increasing the air-stability of various primary phosphines in the absence of kinetic stabilization is presented that contrasts with previous interpretations, which were limited to specific phosphines. This contribution shows the synthesis of a series of air-stable primary phosphines Fc(CH₂)nPH₂, where n=0,1,2,3; and Fc=ferrocenyl, and their corresponding isolable primary phosphine oxides. It was demonstrated that the ferrocene moiety exerts an antioxidant effect on the primary phosphine group, ...
Aufsatz
Influence of Ethylene Oxide and Gamma Irradiation Sterilization Processes on the Properties of Poly-L-Lactic-Acid (PLLA) Materials
(2023-08-18)
In order to encourage the substitution of petrochemical polymers in medical technology with sustainable, bio-based materials, there is an urgent need for further investigations, especially data regarding their sterility performance. Within the scope of the investigations, selected material properties of poly-L-lactic-acid (PLLA), a specific type of poly(lactic-acid) (PLA), were analyzed before and after sterilization (using ethylene oxide or gamma irradiation) in order to investigate deviations in its chemical ...
Aufsatz
Influence of Chitosan and Grape Seed Extract on Thermal and Mechanical Properties of PLA Blends
(2023-03-22)
Blends based on polylactic acid (PLA), chitosan, and grape seed extract (GE) were prepared by extrusion and injection molding. The effect of chitosan (5% and 15% on PLA basis) and natural extract (1% on PLA basis) incorporated into the PLA host matrix was explored regarding the thermal and mechanical properties. GE showed antioxidant activity, as determined by the DPPH assay method. Chitosan and GE affect the degree of crystallinity up to 30% as the polysaccharide acts as a nucleating agent, while the extract reduces ...