The absorption spectrum and photoluminescence spectrum of multiwalled carbon nanotubes(MWNTs) and the peaks related with Van Hove singularities(VHS) were obtained experimentally.Both the VHS formation and the change o...The absorption spectrum and photoluminescence spectrum of multiwalled carbon nanotubes(MWNTs) and the peaks related with Van Hove singularities(VHS) were obtained experimentally.Both the VHS formation and the change of band gaps in MWNTs depend on the intershell interaction.The VHS makes the probability of optical transitions enhanced,but the intershell interaction suppresses such radiative transitions.The excitation in the experiment involves a two-photon absorption process and the emission light has the effect of the optical frequency up-conversion.展开更多
目的分析骨质疏松性椎体压缩骨折(osteoporotic vertebral compression fractures,OVCF)患者经皮椎体成形术(percutaneous vertebroplasty,PVP)术后疼痛缓解不佳的危险因素并构建列线图。方法选取2019年7月至2022年6月,我院PVP治疗的136...目的分析骨质疏松性椎体压缩骨折(osteoporotic vertebral compression fractures,OVCF)患者经皮椎体成形术(percutaneous vertebroplasty,PVP)术后疼痛缓解不佳的危险因素并构建列线图。方法选取2019年7月至2022年6月,我院PVP治疗的136例OVCF患者。根据术前1天和术后1个月的疼痛视觉模拟评分(visual analogue scales,VAS)差值定义疼痛缓解不佳和疼痛缓解良好。通过多因素Logistic回归分析OVCF患者术后疼痛缓解不佳的独立危险因素。通过接收者操作特征曲线(receiver operating characteristic curve,ROC)评估独立危险因素的诊断能力。基于独立危险因素列线图并通过校正曲线和决策曲线分析评估列线图预测准确性和临床净收益。结果PVP术后疼痛缓解不佳患者58例(42.6%),疼痛缓解良好患者78例(57.4%)。多因素Logistic回归分析结果显示,年龄、美国麻醉医师协会(American Society of Anesthesiologists,ASA)分级(Ⅲ~Ⅳ级)、吸烟、胸腰筋膜损伤、骨密度(bone mineral density,BMD)、骨水泥注入量和骨水泥渗漏是PVP术后疼痛缓解不佳的独立危险因素(P<0.05)。年龄、ASA分级、吸烟、胸腰筋膜损伤、BMD、骨水泥注入量和骨水泥渗漏曲线下面积(area under the curve,AUC)分别为0.782、0.604、0.601、0.622、0.743、0.840和0.651。PVP术后疼痛缓解不佳风险的列线图校正曲线与原始曲线及理想曲线接近,C-index为0.814(95%CI:0.704~0.913),模型拟合度高。当列线图预测风险阈值在0.08~1.00时,能提供显著意义的临床净收益。结论基于年龄、ASA分级、吸烟、胸腰筋膜损伤、BMD、骨水泥注入量和骨水泥渗漏构建的列线图能有效定量OVCF患者PVP术后疼痛缓解不佳风险。展开更多
文摘The absorption spectrum and photoluminescence spectrum of multiwalled carbon nanotubes(MWNTs) and the peaks related with Van Hove singularities(VHS) were obtained experimentally.Both the VHS formation and the change of band gaps in MWNTs depend on the intershell interaction.The VHS makes the probability of optical transitions enhanced,but the intershell interaction suppresses such radiative transitions.The excitation in the experiment involves a two-photon absorption process and the emission light has the effect of the optical frequency up-conversion.
文摘目的分析骨质疏松性椎体压缩骨折(osteoporotic vertebral compression fractures,OVCF)患者经皮椎体成形术(percutaneous vertebroplasty,PVP)术后疼痛缓解不佳的危险因素并构建列线图。方法选取2019年7月至2022年6月,我院PVP治疗的136例OVCF患者。根据术前1天和术后1个月的疼痛视觉模拟评分(visual analogue scales,VAS)差值定义疼痛缓解不佳和疼痛缓解良好。通过多因素Logistic回归分析OVCF患者术后疼痛缓解不佳的独立危险因素。通过接收者操作特征曲线(receiver operating characteristic curve,ROC)评估独立危险因素的诊断能力。基于独立危险因素列线图并通过校正曲线和决策曲线分析评估列线图预测准确性和临床净收益。结果PVP术后疼痛缓解不佳患者58例(42.6%),疼痛缓解良好患者78例(57.4%)。多因素Logistic回归分析结果显示,年龄、美国麻醉医师协会(American Society of Anesthesiologists,ASA)分级(Ⅲ~Ⅳ级)、吸烟、胸腰筋膜损伤、骨密度(bone mineral density,BMD)、骨水泥注入量和骨水泥渗漏是PVP术后疼痛缓解不佳的独立危险因素(P<0.05)。年龄、ASA分级、吸烟、胸腰筋膜损伤、BMD、骨水泥注入量和骨水泥渗漏曲线下面积(area under the curve,AUC)分别为0.782、0.604、0.601、0.622、0.743、0.840和0.651。PVP术后疼痛缓解不佳风险的列线图校正曲线与原始曲线及理想曲线接近,C-index为0.814(95%CI:0.704~0.913),模型拟合度高。当列线图预测风险阈值在0.08~1.00时,能提供显著意义的临床净收益。结论基于年龄、ASA分级、吸烟、胸腰筋膜损伤、BMD、骨水泥注入量和骨水泥渗漏构建的列线图能有效定量OVCF患者PVP术后疼痛缓解不佳风险。
