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Novel biodegradable polyesters, such as poly(ethylene sebacate) (PESeb), poly(propylene sebacate) (PPSeb), and poly(butylene sebacate) (PBSeb), were synthesized and studied with respect to melting behavior, crystallization kinetics, and enzymatic hydrolysis. PESeb and PPSeb showed multiple melting behavior. Wide angle X‐ray diffractometry measurements at various temperatures, standard, step‐scan, and high‐rate differential scanning calorimetry methods were applied to elucidate the appearance of multiple endotherms in heating scans, which was interpreted in the context of partial melting‐recrystallization and final melting. PBSeb did not show any multiple melting behavior but only a weak tendency for recrystallization on heating. The melting temperatures of PESeb, PPSeb, and PBSeb were measured equal to 78, 57, and 71 °C, respectively. The equilibrium melting points were estimated to be Tm° = 90.2, 69.9, and 77.4 °C for PESeb, PPSeb, and PBSeb, while the corresponding enthalpy of fusion values were found to be ΔHf = 170 ± 10, 140 ± 10, and 155 ± 10 J/g, respectively. The polyesters showed fast crystallization rates under both isothermal and nonisothermal conditions. Crystallization kinetics was thoroughly investigated using macrokinetic models and isoconversional analysis. Enzymatic hydrolysis rate in the presence of lipases Rhizopus delemar and Pseudomonas cepacia was found to be fast for PPSeb, whereas PESeb and PBSeb showed slow rates and comparable with those of PCL. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 672–686, 2010

Variations in cytokinins, mineral nutrient elements of xylem exudates collected before bud burst, petiole and blade nutrient concentration at veraison, and shoot growth patterns were studied as affected by the rootstock. A two year experiment was conducted on field grown grapevines cv. Thompson seedless, grafted onto 420AMgt, 110Richter, 99Richter, 41BMgt, Kober 5BB, 8B Teleki, 1103 Paulsen, 31 Richter and 3309C rootstocks. Xylem exudate cytokinins were positively correlated with relative bud burst number, shoot elongation in the early season, and shoot elongation at veraison stage. A strong positive relationship between cytokinin content and total nitrogen was also found. The rootstocks 420AMgt, 110Richter, and 99Richter, which showed high levels in cytokinin content also had high nitrogen levels in xylem exudates and leaf blade. Multivariate Analysis allowed to show that rootstocks with similar levels in cytokinin concentrations in xylem exudates, also presented a closely similar behaviour in nutrient uptake. Grapevine / rootstock / xylem sap / cytokinin / mineral uptake Résumé-Étude de l'effet de différents porte-greffes sur la concentration en cytokinines dans les pleurs du bois, l'absorption minérale et les caractéristiques de croissance de la vigne Vitis vinifera cv. Sultanine. Les variations de la teneur en cytokinines et en éléments minéraux des exudats du xylème récoltés avant le débourrement, de la compositions minérale du limbe et du pétiole à la véraison, et de la croissance des rameaux ont été étudiées en fonction du porte-greffe. Les essais ont été réalisés au champ sur la variété Sultanine greffée sur les porte-greffes 420A Mgt, 110Richter, 41B Mgt, Kober 5BB, Teleki 8B, 1103 Paulsen, 31Richter, et 3309 Couderc. La concentration en cytokinines dans les exudats du xylème a été positivement corrélée avec le nombre relatif de bourgeons débourrés et avec l'allongement des rameaux au début de la période végétative et à la véraison. Une corrélation élevée entre la concentration en cytokinines et la teneur en azote totale a également été mise en évidence. Les porte-greffe 420A Mgt,