目的研究定量骨断层标准摄取值(standardized uptake value,SUV)与骨矿物质密度(bone mineral density,BMD)的相关性。方法回顾性分析了84例于2019年6月1日—2020年2月1日接受骨密度测量及骨断层显像患者的数据,依照BMD结果分为骨质疏...目的研究定量骨断层标准摄取值(standardized uptake value,SUV)与骨矿物质密度(bone mineral density,BMD)的相关性。方法回顾性分析了84例于2019年6月1日—2020年2月1日接受骨密度测量及骨断层显像患者的数据,依照BMD结果分为骨质疏松、低骨量和骨量正常共3组,分析不同性别及诊断组间腰椎、股骨颈及全髋T值、BMD、平均SUV(mean SUV,SUVmean)及最大SUV(maximum SUV,SUVmax)差异,并比较SUV与各组数据的相关性。结果男性腰椎BMD、SUVmean及SUVmax均显著高于女性[(1.075±0.191)g/cm^(2) vs(0.950±0.200)g/cm^(2),P=0.004;4.72±0.84 vs 4.23±0.63,P=0.003;9.65±2.10 vs 8.58±1.47,P=0.008]。骨质疏松组腰椎BMD、SUVmean及SUVmax[(0.818±0.080)g/cm^(2),4.26±0.56,8.49±1.52]均显著低于低骨量组[(1.013±0.105)g/cm^(2),4.38±0.70,9.02±1.68]及骨量正常组[(1.264±0.147)g/cm^(2),4.87±1.00,10.03±2.25,P<0.01],腰椎SUVmean及SUVmax与BMD值呈正相关(r=0.451,0.409,P<0.01),而股骨颈和全髋的SUVmean及SUVmax与BMD之间无相关性(P>0.05)。结论骨质疏松症患者腰椎SUV显著降低,且与BMD呈正相关。提示SUV能够在一定程度上反映BMD,为临床提供更多诊断信息。展开更多
A multi-inclusion cell model is used to investigate the effect of deformation temperature and whisker rotation on the hot compressive behavior of metal matrix composites with misaligned whiskers. Numerical results sho...A multi-inclusion cell model is used to investigate the effect of deformation temperature and whisker rotation on the hot compressive behavior of metal matrix composites with misaligned whiskers. Numerical results show that deformation temperature influences the work-hardening behavior of the matrix and the rotation behavior of the whiskers. With increasing temperature, the work hardening rate of the matrix decreases, but the whisker rotation angle increases. Both whisker rotation and the increase of deformation temperature can induce reductions in the load supported by whisker and the load transferred from matrix to whisker. Additionally, it is found that during large strain deformation at higher temperatures, the enhancing of deformation temperature can reduce the effect of whisker rotation. Meanwhile, the stress-strain behavior of the composite is rather sensitive to deformation temperature. At a relatively lower temperature （150℃）, the composite exhibits work hardening due to the matrix work hardening, but at relatively higher temperatures （300℃ and above）, the composite shows strain softening due to whisker rotation. It is also found that during hot compression at higher temperatures, the softening rate of the composite decreases with increasing temperature. The predicted stress-strain behavior of the composite is approximately in agreement with the experimental results.展开更多
文摘目的研究定量骨断层标准摄取值(standardized uptake value,SUV)与骨矿物质密度(bone mineral density,BMD)的相关性。方法回顾性分析了84例于2019年6月1日—2020年2月1日接受骨密度测量及骨断层显像患者的数据,依照BMD结果分为骨质疏松、低骨量和骨量正常共3组,分析不同性别及诊断组间腰椎、股骨颈及全髋T值、BMD、平均SUV(mean SUV,SUVmean)及最大SUV(maximum SUV,SUVmax)差异,并比较SUV与各组数据的相关性。结果男性腰椎BMD、SUVmean及SUVmax均显著高于女性[(1.075±0.191)g/cm^(2) vs(0.950±0.200)g/cm^(2),P=0.004;4.72±0.84 vs 4.23±0.63,P=0.003;9.65±2.10 vs 8.58±1.47,P=0.008]。骨质疏松组腰椎BMD、SUVmean及SUVmax[(0.818±0.080)g/cm^(2),4.26±0.56,8.49±1.52]均显著低于低骨量组[(1.013±0.105)g/cm^(2),4.38±0.70,9.02±1.68]及骨量正常组[(1.264±0.147)g/cm^(2),4.87±1.00,10.03±2.25,P<0.01],腰椎SUVmean及SUVmax与BMD值呈正相关(r=0.451,0.409,P<0.01),而股骨颈和全髋的SUVmean及SUVmax与BMD之间无相关性(P>0.05)。结论骨质疏松症患者腰椎SUV显著降低,且与BMD呈正相关。提示SUV能够在一定程度上反映BMD,为临床提供更多诊断信息。
基金This study was financially supported by the National Natural Science Foundation of China (No. 50071008).
文摘A multi-inclusion cell model is used to investigate the effect of deformation temperature and whisker rotation on the hot compressive behavior of metal matrix composites with misaligned whiskers. Numerical results show that deformation temperature influences the work-hardening behavior of the matrix and the rotation behavior of the whiskers. With increasing temperature, the work hardening rate of the matrix decreases, but the whisker rotation angle increases. Both whisker rotation and the increase of deformation temperature can induce reductions in the load supported by whisker and the load transferred from matrix to whisker. Additionally, it is found that during large strain deformation at higher temperatures, the enhancing of deformation temperature can reduce the effect of whisker rotation. Meanwhile, the stress-strain behavior of the composite is rather sensitive to deformation temperature. At a relatively lower temperature （150℃）, the composite exhibits work hardening due to the matrix work hardening, but at relatively higher temperatures （300℃ and above）, the composite shows strain softening due to whisker rotation. It is also found that during hot compression at higher temperatures, the softening rate of the composite decreases with increasing temperature. The predicted stress-strain behavior of the composite is approximately in agreement with the experimental results.
