Phosphorus (P) is necessary for growth and nitrogen fixation, and thus its deficiency is a major factor limiting legume production in most agricultural soils. The effect of phosphorus supply on nodule development and ...Phosphorus (P) is necessary for growth and nitrogen fixation, and thus its deficiency is a major factor limiting legume production in most agricultural soils. The effect of phosphorus supply on nodule development and its role in soybeans (Glycine max L.) was studied in a nutrient solution. Plants were inoculated with Bradyrhizobium japonicum and grown for 35 days in a glasshouse at a day and night temperature of 25℃and 15℃, respectively. Although increasing P supply increased the concentrations of P and N in the shoots and roots, the external P supply did not significantly affect the P concentration in the nodules, and the N fixed per unit nodule biomass decreased with increasing P supply. The nitrogen content in the shoots correlated well with the P content (r = 0.92**). At an inoculation level of 102 cells mL-1, the P supply did not affect the number of nodules; however, at inoculation levels of 103.5 and 105 cells mL-1, increasing P supply increased both the number and size of nodules. Irrespective of the inoculation level, increasing P supply increased the nodule biomass relative to the biomass of the host plant. It is suggested that the P deficiency specifically inhibited the nodule development and thereby the total N2 fixation.展开更多
目的 探讨后路经伤椎椎弓根短钉置钉短节段复位内固定治疗单节段压缩性胸腰椎骨折的有效性和安全性.方法 回顾性分析2010年1月至2012年1月间于我院手术的单节段压缩性胸腰椎骨折患者87例的临床资料.根据手术方法的不同将患者分为经伤椎...目的 探讨后路经伤椎椎弓根短钉置钉短节段复位内固定治疗单节段压缩性胸腰椎骨折的有效性和安全性.方法 回顾性分析2010年1月至2012年1月间于我院手术的单节段压缩性胸腰椎骨折患者87例的临床资料.根据手术方法的不同将患者分为经伤椎短钉置钉后路减压复位内固定术（伤椎置钉组）和常规后路减压复位短节段融合内固定术组（短节段固定组）.统计手术时间和术中出血量,评估患者术后疼痛;收集术前、术后即刻及术后1年随访数字射线摄影（DR）侧位片上的伤椎上、下椎体Cobb角、伤椎椎体前缘高度（前高）,计算伤椎前高压缩比.结果 共73例患者有完整的随访资料,其中伤椎置钉组38例,短节段固定组35例.术前两组年龄、伤椎前高压缩比和Cobb角比较差异无统计学意义.伤椎置钉组手术时间长于短节段固定组（121 min vs 92 min,P＜0.05）,术后即刻及术后1年椎体前高压缩比均高于短节段固定组[术后即刻91.3％（82％～93％） vs 77.2％（73％～86％）,P＜0.05;术后1年87.2％ （79％～93％） vs 73.1％（68％～80％）,P＜0.05],术后1年伤椎的上、下椎体Cobb角小于短节段固定组[7.8°（0°～15°）vs11°（2°～17°）,P＜0.05].手术出血量、疼痛评分两组比较差异无统计学意义.结论 后路经伤椎椎弓根短钉置钉短节段复位内固定治疗单节段压缩性胸腰椎骨折能安全、有效地重建椎体高度,矫正脊柱后凸畸形.展开更多
基金Project supported by the National Basic Research Program of China (Nos. 2005CB121101 and 2003CCB001)the Basic Research Program of Heilongjiang Province (Nos. GB05C201-01 and CC055303)the Field Station Foundation of the Chinese Academy of Sciences.
文摘Phosphorus (P) is necessary for growth and nitrogen fixation, and thus its deficiency is a major factor limiting legume production in most agricultural soils. The effect of phosphorus supply on nodule development and its role in soybeans (Glycine max L.) was studied in a nutrient solution. Plants were inoculated with Bradyrhizobium japonicum and grown for 35 days in a glasshouse at a day and night temperature of 25℃and 15℃, respectively. Although increasing P supply increased the concentrations of P and N in the shoots and roots, the external P supply did not significantly affect the P concentration in the nodules, and the N fixed per unit nodule biomass decreased with increasing P supply. The nitrogen content in the shoots correlated well with the P content (r = 0.92**). At an inoculation level of 102 cells mL-1, the P supply did not affect the number of nodules; however, at inoculation levels of 103.5 and 105 cells mL-1, increasing P supply increased both the number and size of nodules. Irrespective of the inoculation level, increasing P supply increased the nodule biomass relative to the biomass of the host plant. It is suggested that the P deficiency specifically inhibited the nodule development and thereby the total N2 fixation.
文摘目的 探讨后路经伤椎椎弓根短钉置钉短节段复位内固定治疗单节段压缩性胸腰椎骨折的有效性和安全性.方法 回顾性分析2010年1月至2012年1月间于我院手术的单节段压缩性胸腰椎骨折患者87例的临床资料.根据手术方法的不同将患者分为经伤椎短钉置钉后路减压复位内固定术（伤椎置钉组）和常规后路减压复位短节段融合内固定术组（短节段固定组）.统计手术时间和术中出血量,评估患者术后疼痛;收集术前、术后即刻及术后1年随访数字射线摄影（DR）侧位片上的伤椎上、下椎体Cobb角、伤椎椎体前缘高度（前高）,计算伤椎前高压缩比.结果 共73例患者有完整的随访资料,其中伤椎置钉组38例,短节段固定组35例.术前两组年龄、伤椎前高压缩比和Cobb角比较差异无统计学意义.伤椎置钉组手术时间长于短节段固定组（121 min vs 92 min,P＜0.05）,术后即刻及术后1年椎体前高压缩比均高于短节段固定组[术后即刻91.3％（82％～93％） vs 77.2％（73％～86％）,P＜0.05;术后1年87.2％ （79％～93％） vs 73.1％（68％～80％）,P＜0.05],术后1年伤椎的上、下椎体Cobb角小于短节段固定组[7.8°（0°～15°）vs11°（2°～17°）,P＜0.05].手术出血量、疼痛评分两组比较差异无统计学意义.结论 后路经伤椎椎弓根短钉置钉短节段复位内固定治疗单节段压缩性胸腰椎骨折能安全、有效地重建椎体高度,矫正脊柱后凸畸形.
