To investigate the relationship between the ATP content in human oocytes and the deve-lopmental potential of human oocytes, unfertilized oocytes from clinical IVF and immature oocytes unsuitable for ICSI were collecte...To investigate the relationship between the ATP content in human oocytes and the deve-lopmental potential of human oocytes, unfertilized oocytes from clinical IVF and immature oocytes unsuitable for ICSI were collected. The ATP content of these unfertilized and in vitro matured eggs were determined quantitatively by measuring the luminescence using an ATP-dependent bioluminescence assay. The result showed that the ATP content of unfertilized oocytes was higher than in vitro matured ones (2.20±0.67 pmol vs 1.72±0.49 pmol, P<0.05 ). In unfertilized oocytes, the ATP content of those whose fertilization rates (FR) was higher than 50 % was 2.43±0.60 pmol, which was significantly different from those whose FR was less than 50 % (1.72±0.56 pmol), while in in vitro matured oocytes, the ATP content of those whose FR more than 50 % was 1.8±0.44 pmol, slightly higher than those less than 50 % (1.55±0.40 pmol), without statistical significance. There was a tendency that the ATP content of oocytes of pregnant patients was higher than those of controls, but the sample number was too small to show any significance in statistics. Briefly, there was positive correlation between the ATP content in oocytes and developmental potential of oocytes.展开更多
In this study,newly developed low content PCBN was used to evaluate the cutting performance in high speed turning of hardened steel.Using new PCBN and commercially available PCBN tipped inserts under the same cutting ...In this study,newly developed low content PCBN was used to evaluate the cutting performance in high speed turning of hardened steel.Using new PCBN and commercially available PCBN tipped inserts under the same cutting condition,cutting performance with variable cutting speed,feed rate and depth of cuts on tools were measured by observation of flank and crater wear.Its microstructures were analyzed through SEM microscope,measurement of surface roughness on workpiece was also performed. According to cutting performance results,it is shown that new PCBN shows much longer tool life in high speed continuous turning than our conventional PCBN tools,with improved wear and chipping resistance.This result on the machinability of new PCBN for hardened steel will provide effective guidelines to manufacturing engineers,also provide useful economic machining solution for high speed continuous turning for hardened steel.展开更多
Genetic control of leucine content in indica-japonica hybrid rice (Oryza sativa L.) was studied in 35 crosses of F1 and F2 generations, which were derived from crossing 7 male sterile indica rice lines with 5 restorer...Genetic control of leucine content in indica-japonica hybrid rice (Oryza sativa L.) was studied in 35 crosses of F1 and F2 generations, which were derived from crossing 7 male sterile indica rice lines with 5 restorer japonica rice lines along with their parents. Two genetic models and their corresponding statistical methods for quantitative traits of triploid seeds in cereal crops were used for the analysis. The first was the unconditional genetic model, which refers to the analysis of cumulative measurements (from flowering to a specific time) along the developmental stages, while the second was the conditional genetic model, which relates to analysis from one developmental stage to another stage (t - 1→t). The results showed that leucine content of indica-japonica hybrid rice was controlled by the expression of triploid endosperm effect (endosperm additive effect and endosperm dominant effect), cytoplasm effect, diploid maternal plant effect (maternal additive effect and maternal dominant effect) and their environmental interaction effects. Of these effects, endosperm dominant effect and maternal dominant effect were more important at the earlier stages, while endosperm additive effect and maternal additive effect were more important at the later stages of rice grain development under both unconditional and conditional genetic analyses. Due to the high heritabilities, which came from endosperm, maternal and cytoplasm effects for leucine content at different developmental stages, selection for leucine content of indica-japonica hybrid rice would be more efficient at early generations in breeding programs.展开更多
文摘To investigate the relationship between the ATP content in human oocytes and the deve-lopmental potential of human oocytes, unfertilized oocytes from clinical IVF and immature oocytes unsuitable for ICSI were collected. The ATP content of these unfertilized and in vitro matured eggs were determined quantitatively by measuring the luminescence using an ATP-dependent bioluminescence assay. The result showed that the ATP content of unfertilized oocytes was higher than in vitro matured ones (2.20±0.67 pmol vs 1.72±0.49 pmol, P<0.05 ). In unfertilized oocytes, the ATP content of those whose fertilization rates (FR) was higher than 50 % was 2.43±0.60 pmol, which was significantly different from those whose FR was less than 50 % (1.72±0.56 pmol), while in in vitro matured oocytes, the ATP content of those whose FR more than 50 % was 1.8±0.44 pmol, slightly higher than those less than 50 % (1.55±0.40 pmol), without statistical significance. There was a tendency that the ATP content of oocytes of pregnant patients was higher than those of controls, but the sample number was too small to show any significance in statistics. Briefly, there was positive correlation between the ATP content in oocytes and developmental potential of oocytes.
基金Suported by Advanced Technolgy center prject(No.10020604)
文摘In this study,newly developed low content PCBN was used to evaluate the cutting performance in high speed turning of hardened steel.Using new PCBN and commercially available PCBN tipped inserts under the same cutting condition,cutting performance with variable cutting speed,feed rate and depth of cuts on tools were measured by observation of flank and crater wear.Its microstructures were analyzed through SEM microscope,measurement of surface roughness on workpiece was also performed. According to cutting performance results,it is shown that new PCBN shows much longer tool life in high speed continuous turning than our conventional PCBN tools,with improved wear and chipping resistance.This result on the machinability of new PCBN for hardened steel will provide effective guidelines to manufacturing engineers,also provide useful economic machining solution for high speed continuous turning for hardened steel.
文摘Genetic control of leucine content in indica-japonica hybrid rice (Oryza sativa L.) was studied in 35 crosses of F1 and F2 generations, which were derived from crossing 7 male sterile indica rice lines with 5 restorer japonica rice lines along with their parents. Two genetic models and their corresponding statistical methods for quantitative traits of triploid seeds in cereal crops were used for the analysis. The first was the unconditional genetic model, which refers to the analysis of cumulative measurements (from flowering to a specific time) along the developmental stages, while the second was the conditional genetic model, which relates to analysis from one developmental stage to another stage (t - 1→t). The results showed that leucine content of indica-japonica hybrid rice was controlled by the expression of triploid endosperm effect (endosperm additive effect and endosperm dominant effect), cytoplasm effect, diploid maternal plant effect (maternal additive effect and maternal dominant effect) and their environmental interaction effects. Of these effects, endosperm dominant effect and maternal dominant effect were more important at the earlier stages, while endosperm additive effect and maternal additive effect were more important at the later stages of rice grain development under both unconditional and conditional genetic analyses. Due to the high heritabilities, which came from endosperm, maternal and cytoplasm effects for leucine content at different developmental stages, selection for leucine content of indica-japonica hybrid rice would be more efficient at early generations in breeding programs.
