The experimental orchard on calcareous soils in the Tikves region has been established in 1999, in order to investigate the influence of the rootstocks on the behaviour of the peach trees. In the experiment we evaluat...The experimental orchard on calcareous soils in the Tikves region has been established in 1999, in order to investigate the influence of the rootstocks on the behaviour of the peach trees. In the experiment we evaluated next rootstocks： Nemaguard （Prunus persica × Prunus davidiana）, seedlings of GF 677 （Prunus persica ×Prunus amygdalus）, hybrids BMVA 1, BMVA 2, VAF 215 and Autochthones type and GF 677 （Prunus persica × Prunus amygdalus） clonal. As control rootstocks in our experiment was used seedlings from vineyard peach （Prunus persica）. The experiment was established with one year old trees from Redhaven variety. Agronomical characteristics （vegetative growth, occurrence of leaf chlorosis, tree mortality, yield, productivity and fruit quality） of the trees on different rootstocks have been measured over a twelve-year period （1999-2010）. Significant differences on the level of P 〈 0.05 have been observed on vigour of the trees. The most vigorous trees were those on GF 677 clonal, GF 677 seedling and BMVA 2. The trees on Vineyard peach and Nemaguard was the weakest ones. The highest cumulative yield was recorded on GF-677 clonal rootstock, and the lowest on Nemaguard. Occurrence of chlorosis was the highest at Vineyard peach, Nemaguard and Autochthones hybrid, GF 677 clonal was the only rootstock without iron chlorosis. The percent of tree mortality to twelfth year was the highest at Autochthones hybrid （33.3）, and at GF 677 clonal and BMVA 1 had not tree mortality.展开更多
To explore the preparative method an d study the degradation characteristics of bone repair composite of DL polylac tic acid (PDLLA)/hydroxyapatite(HA)/decalcifying bone matrix (DBM) in vitro. Methods: An emulsion ble...To explore the preparative method an d study the degradation characteristics of bone repair composite of DL polylac tic acid (PDLLA)/hydroxyapatite(HA)/decalcifying bone matrix (DBM) in vitro. Methods: An emulsion blend method was developed to prepare the composite of PDLLA/HA/DBM in weight ratio of PDLLA:HA:DBM= 1.5 2 : 1 1.5 : 1. The dynamic changes of weight, biomechanical property and pH value of PDLLA/ HA/DBM and PDLLA in phosphate buffered saline (PBS, pH 7.4 ) were studied re spectively through degradation tests in vitro. Results: Without being heated, PDLLA, HA and DBM could be synt hesized with the emulsion blend method as bone composite of PDLLA/HA/DBM, which had both osteoconductive and osteoinductive effects. The diameter of the apertu re was 100 400 μm and the gap rate was 71.3 %. During degradation, the pH v alue of PDLLA solution decreased lightly within 2 weeks, but decreased obviously at the end of 4 weeks and the value was 4.0 . While the pH value of PDLLA/H A/DBM kept quite steady and was 6.4 at the end of 12 weeks. The weight of PDLLA changed little within 4 weeks, then changed obviously and was 50% of its initia l weight at the end of 12 weeks. While the weight of PDLLA/HA/DBM changed little within 5 weeks, then changed obviously and was 60% of the initial weight at the end of 12 weeks. The initial biomechanical strength of PDLLA was 1.33 MPa, decreased little within 3 weeks, then changed obviously and kept at 0.11 MP a at the end of 12 weeks. The initial biomechanical strength of PDLLA/HA/DBM was 1.7 MPa, decreased little within 4 weeks, then changed obviously and kept at 0.21 MPa at the end of 12 weeks. Conclusions: The emulsion blend method is a new method to prepa re bone repair materials. As a new bone repair material, PDLLA/HA/DBM is more su itable for regeneration and cell implantation, and the environment during its de gradation is advantageous to the growth of bone cells.展开更多
文摘The experimental orchard on calcareous soils in the Tikves region has been established in 1999, in order to investigate the influence of the rootstocks on the behaviour of the peach trees. In the experiment we evaluated next rootstocks： Nemaguard （Prunus persica × Prunus davidiana）, seedlings of GF 677 （Prunus persica ×Prunus amygdalus）, hybrids BMVA 1, BMVA 2, VAF 215 and Autochthones type and GF 677 （Prunus persica × Prunus amygdalus） clonal. As control rootstocks in our experiment was used seedlings from vineyard peach （Prunus persica）. The experiment was established with one year old trees from Redhaven variety. Agronomical characteristics （vegetative growth, occurrence of leaf chlorosis, tree mortality, yield, productivity and fruit quality） of the trees on different rootstocks have been measured over a twelve-year period （1999-2010）. Significant differences on the level of P 〈 0.05 have been observed on vigour of the trees. The most vigorous trees were those on GF 677 clonal, GF 677 seedling and BMVA 2. The trees on Vineyard peach and Nemaguard was the weakest ones. The highest cumulative yield was recorded on GF-677 clonal rootstock, and the lowest on Nemaguard. Occurrence of chlorosis was the highest at Vineyard peach, Nemaguard and Autochthones hybrid, GF 677 clonal was the only rootstock without iron chlorosis. The percent of tree mortality to twelfth year was the highest at Autochthones hybrid （33.3）, and at GF 677 clonal and BMVA 1 had not tree mortality.
文摘To explore the preparative method an d study the degradation characteristics of bone repair composite of DL polylac tic acid (PDLLA)/hydroxyapatite(HA)/decalcifying bone matrix (DBM) in vitro. Methods: An emulsion blend method was developed to prepare the composite of PDLLA/HA/DBM in weight ratio of PDLLA:HA:DBM= 1.5 2 : 1 1.5 : 1. The dynamic changes of weight, biomechanical property and pH value of PDLLA/ HA/DBM and PDLLA in phosphate buffered saline (PBS, pH 7.4 ) were studied re spectively through degradation tests in vitro. Results: Without being heated, PDLLA, HA and DBM could be synt hesized with the emulsion blend method as bone composite of PDLLA/HA/DBM, which had both osteoconductive and osteoinductive effects. The diameter of the apertu re was 100 400 μm and the gap rate was 71.3 %. During degradation, the pH v alue of PDLLA solution decreased lightly within 2 weeks, but decreased obviously at the end of 4 weeks and the value was 4.0 . While the pH value of PDLLA/H A/DBM kept quite steady and was 6.4 at the end of 12 weeks. The weight of PDLLA changed little within 4 weeks, then changed obviously and was 50% of its initia l weight at the end of 12 weeks. While the weight of PDLLA/HA/DBM changed little within 5 weeks, then changed obviously and was 60% of the initial weight at the end of 12 weeks. The initial biomechanical strength of PDLLA was 1.33 MPa, decreased little within 3 weeks, then changed obviously and kept at 0.11 MP a at the end of 12 weeks. The initial biomechanical strength of PDLLA/HA/DBM was 1.7 MPa, decreased little within 4 weeks, then changed obviously and kept at 0.21 MPa at the end of 12 weeks. Conclusions: The emulsion blend method is a new method to prepa re bone repair materials. As a new bone repair material, PDLLA/HA/DBM is more su itable for regeneration and cell implantation, and the environment during its de gradation is advantageous to the growth of bone cells.
