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261.
In this study, we investigated the timber harvesting effects on some soil properties (sand, silt, clay, pH, electrical conductivity, fine soil <2 mm, coarse soil >2 mm, root mass, organic carbon, moisture equivalent, total porosity, bulk density, moisture and compaction) at soil depths (0–5 and 5–10 cm), herbaceous cover and forest floor (unit mass, organic matter and moisture) on skid road of an oak (Quercus petrea L.) stand in Istanbul Belgrad Forest of Turkey. 相似文献
262.
263.
The electrochemical behaviors of 10 structurally different flavonoids (quercetin, galangin, chrysin, 3-hydroxyflavone, naringenin, luteolin, apigenin, flavone, kaempferol, and naringin) on a glassy carbon electrode were studied by cyclic voltammetry. In the current study, nitrophenyl diazonium salt has been synthesized from p-nitrophenylamine. One millimolar prepared nitrophenyl diazonium salt (in 100 mM tetrabutylammonium tetrafluoroborate) in acetonitrile was used to modify the glassy carbon electrode. Nitro groups have been reduced to amine groups in 100 mM HCl medium on the nitrophenyl-modified glassy carbon electrode surface. Although nitrophenyl-modified glassy carbon electrode surface was electro-inactive, it is activated by reducing the nitro group into amine group. And then, aminophenyl-modified glassy carbon electrode surface has been used for the determination of antioxidant activities of 10 flavonoid derivatives with cyclic voltammetry technique. The activity sequence of the investigated, structurally different, flavonoids follows the sequence: quercetin > galangin > chrysin > 3-hydroxyflavone > naringenin > luteolin > apigenin > flavone > kaempferol > naringin. 相似文献
264.
Gábor Koplányi Dr. Evelin Bell Dr. Zsófia Molnár Dr. Gábor Katona Dr. Péter Lajos Neumann Dr. Ferenc Ender Prof. Dr. György T. Balogh Prof. Dr. Polona Žnidaršič-Plazl Prof. Dr. László Poppe Dr. Diána Balogh-Weiser 《Chembiochem : a European journal of chemical biology》2023,24(7):e202200713
The increasing application of recombinant enzymes demands not only effective and sustainable fermentation, but also highly efficient downstream processing and further stabilization of the enzymes by immobilization. In this study, a novel approach for the isolation and immobilization of His-tagged transaminase from Chromobacterium violaceum (CvTA) has been developed. A recombinant of CvTA was simultaneously isolated and immobilized by binding on silica nanoparticles (SNPs) with metal affinity linkers and additionally within poly(lactic acid) (PLA) nanofibers. The linker length and the nature of the metal ion significantly affected the enzyme binding efficiency and biocatalytic activity of CvTA-SNPs. The formation of PLA nanofibers by electrospinning enabled rapid embedding of CvTA-SNPs biocatalysts and ensured enhanced stability and activity. The developed advanced immobilization method reduces the time required for enzyme isolation, purification and immobilization by more than fourfold compared to a classical stepwise technique. 相似文献