目的探讨行腰椎后路融合内固定术病人围手术期输注悬浮红细胞的危险因素。方法回顾性分析2016年1月至2018年6月在广州市番禺区中医院骨伤科施行腰椎后路融合手术的468例病人的临床资料,选取性别、年龄、身体质量指数(body mass index,B...目的探讨行腰椎后路融合内固定术病人围手术期输注悬浮红细胞的危险因素。方法回顾性分析2016年1月至2018年6月在广州市番禺区中医院骨伤科施行腰椎后路融合手术的468例病人的临床资料,选取性别、年龄、身体质量指数(body mass index,BMI)、吸烟史、饮酒史、糖尿病、高血压、肺部疾病、心脏疾病、肾脏疾病、骨质疏松症、低蛋白血症、美国麻醉师协会(American Society of Anesthe-siologists,ASA)评分、术前血红蛋白(hemoglobin,Hb)、抗凝药物使用史、手术时间、融合节段、椎管减压方式等可能影响围手术期输血的危险因素,先后应用单因素分析和多元Logistic回归分析围手术期输血的独立危险因素。结果 468例病人中有61例(13%)发生输注红细胞事件。单因素分析显示年龄、性别、BMI、术前Hb水平、术前合并心脏疾病、低蛋白血症、骨质疏松症、术前使用抗凝药、ASA评分、融合节段、手术时间、术中出血量、术后引流量及术后并发症是输血事件发生的危险因素。多元Logistic回归分析结果提示,年龄≥66岁(OR=2.3,95%CI为1.2～4.7)、术前Hb≤125 g/L(OR=2.6,95%CI为1.3～5.1)、融合节段≥3个(OR=3.0,95%CI为1.4～6.3)、手术时间≥215 min(OR=4.0,95%CI为2.1～7.6)是增加围手术期输血事件发生的独立危险因素。结论高龄、术前Hb偏低、多节段融合、手术时间过长的病人行腰椎后路融合内固定术围手术期输血风险较高,故在术前准备中应考虑上述预期输血的因素。展开更多
Comprehensive experimental and numerical studies have been undertaken to investigate wave energy dissipation performance and main influencing factors of a lower arc-plate breakwater. The numerical model, which conside...Comprehensive experimental and numerical studies have been undertaken to investigate wave energy dissipation performance and main influencing factors of a lower arc-plate breakwater. The numerical model, which considers nonlinear interactions between waves and the arc-plate breakwater, has been constructed by using the velocity wave- generating method, the volume of fluid (VOF) method and the finite volume method. The results show that the relative width, relative height and relative submergence of the breakwater are three main influencing factors and have significant influence on wave energy dissipation of the lower arc-plate open breakwater. The transmission coefficient is found to decrease with the increasing relative width, and the minimum transmission coefficient is 0.15 when the relative width is 0.45. The reflection coefficient is found to vary slightly with the relative width, and the maximum reflection coefficient is 0.53 when the relative width is 0.45. The transmission and reflection coefficients are shown to increase with the relative wave height for approximately 85% of the experimental tests when the relative width is 0.19 0.45. The transmission coefficients at relative submergences of 0.04, 0.02 and 0 are clearly shown to be greater than those at relative submergences of 0.02 and 0.04, while the reflection coefficient exhibits the opposite relationship. After the wave interacts with the lower arc-plate breakwater, the wave energy is mainly converted into transmission, reflection and dissipation energies. The wave attenuation performance is clearly weakened for waves with greater heights and longer periods.展开更多
A process-based 3D numerical model for surfzone hydrodynamics and beach evolution was established. Comparisons between the experimental data and model results proved that the model could effectively describe the hydro...A process-based 3D numerical model for surfzone hydrodynamics and beach evolution was established. Comparisons between the experimental data and model results proved that the model could effectively describe the hydrodynamics, sediment transport feature and sandbar migration process in the surfzone with satisfactory precision. A series of numerical simulations on the wave breaking and shoaling up to a barred beach were carried out based on the model system. Analyzed from the model results, the wave-induced current system in the surfzone consists of two major processes, which are the phase-averaged undertow caused by wave breaking and the net drift caused by both of the nonlinear wave motion and surface roller effect. When storm waves come to the barred beach, the strong offshore undertow along the beach suppresses the onshore net drift, making the initial sandbar migrate to the seaside. Under the condition of calm wave environment, both the undertow and net drift flow to the shoreline at the offshore side of the sandbar, and then push the initial sandbar to the shoreline. The consideration of surface roller has significant impact on the modeling results of the sandbar migration. As the roller transfer rate increases, the sandbar moves onshore especially under the storm wave condition.展开更多
目的探讨椎体CT值、腰椎MRI椎体骨质量评分(VBQ评分)对绝经后女性骨量异常的诊断价值。方法回顾性分析2018年1月~2022年8月在广州中医药大学附属番禺区中医院骨科收治的210例绝经后女性患者临床资料,根据双能X线骨密度仪的股骨颈T值,将...目的探讨椎体CT值、腰椎MRI椎体骨质量评分(VBQ评分)对绝经后女性骨量异常的诊断价值。方法回顾性分析2018年1月~2022年8月在广州中医药大学附属番禺区中医院骨科收治的210例绝经后女性患者临床资料,根据双能X线骨密度仪的股骨颈T值,将研究对象分为骨量异常组(骨量减少、骨质疏松,n=166)及骨量正常组(n=44),并测量出各组的CT值以及VBQ评分。采用受试者工作特征曲线(receiver operating curve,ROC)计算曲线下面积(area under the curve,AUC),分析筛查方法的诊断价值,确定诊断截断值,同时计算出不同联合方式筛查方法相应的灵敏度、特异度及约登指数。结果单独运用CT值、VBQ评分作为筛查标准时,AUC分别是0.79、0.777,cut-off值分别是116.75 HU、3.24,其约登指数分别是0.520、0.45,具有一定的诊断价值。CT值联合VBQ评分作为筛查标准时,AUC是0.822,灵敏度是75.9%,特异度为75%,约登指数为0.509;CT值与VBQ评分并联(CT值≤116.75 HU或VBQ评分≥3.24)诊断骨量异常时,其灵敏度为95.26%,特异性为49.16%,约登指数为0.444;串联(CT值≤116.75 HU且VBQ评分≥3.24)诊断骨量异常时,其灵敏度为60.73%,特异性为91.73%,约登指数为0.524,具有较高的诊断价值。结论单独或联合运用CT值、VBQ评分对筛查绝经后女性骨量异常均具有一定的诊断价值,可作为筛查绝经后女性骨量异常的补充方法。展开更多
文摘目的探讨行腰椎后路融合内固定术病人围手术期输注悬浮红细胞的危险因素。方法回顾性分析2016年1月至2018年6月在广州市番禺区中医院骨伤科施行腰椎后路融合手术的468例病人的临床资料,选取性别、年龄、身体质量指数(body mass index,BMI)、吸烟史、饮酒史、糖尿病、高血压、肺部疾病、心脏疾病、肾脏疾病、骨质疏松症、低蛋白血症、美国麻醉师协会(American Society of Anesthe-siologists,ASA)评分、术前血红蛋白(hemoglobin,Hb)、抗凝药物使用史、手术时间、融合节段、椎管减压方式等可能影响围手术期输血的危险因素,先后应用单因素分析和多元Logistic回归分析围手术期输血的独立危险因素。结果 468例病人中有61例(13%)发生输注红细胞事件。单因素分析显示年龄、性别、BMI、术前Hb水平、术前合并心脏疾病、低蛋白血症、骨质疏松症、术前使用抗凝药、ASA评分、融合节段、手术时间、术中出血量、术后引流量及术后并发症是输血事件发生的危险因素。多元Logistic回归分析结果提示,年龄≥66岁(OR=2.3,95%CI为1.2～4.7)、术前Hb≤125 g/L(OR=2.6,95%CI为1.3～5.1)、融合节段≥3个(OR=3.0,95%CI为1.4～6.3)、手术时间≥215 min(OR=4.0,95%CI为2.1～7.6)是增加围手术期输血事件发生的独立危险因素。结论高龄、术前Hb偏低、多节段融合、手术时间过长的病人行腰椎后路融合内固定术围手术期输血风险较高,故在术前准备中应考虑上述预期输血的因素。
基金supported by the NSFC-Shandong Joint Fund(Grant Nos.U1706220 and U1806227)the National Natural Science Foundation of China(Grant Nos.51709140 and 51879019)the Key Laboratory of Coastal Disasters and Defence of Ministry of Education(Grant No.201703)
文摘Comprehensive experimental and numerical studies have been undertaken to investigate wave energy dissipation performance and main influencing factors of a lower arc-plate breakwater. The numerical model, which considers nonlinear interactions between waves and the arc-plate breakwater, has been constructed by using the velocity wave- generating method, the volume of fluid (VOF) method and the finite volume method. The results show that the relative width, relative height and relative submergence of the breakwater are three main influencing factors and have significant influence on wave energy dissipation of the lower arc-plate open breakwater. The transmission coefficient is found to decrease with the increasing relative width, and the minimum transmission coefficient is 0.15 when the relative width is 0.45. The reflection coefficient is found to vary slightly with the relative width, and the maximum reflection coefficient is 0.53 when the relative width is 0.45. The transmission and reflection coefficients are shown to increase with the relative wave height for approximately 85% of the experimental tests when the relative width is 0.19 0.45. The transmission coefficients at relative submergences of 0.04, 0.02 and 0 are clearly shown to be greater than those at relative submergences of 0.02 and 0.04, while the reflection coefficient exhibits the opposite relationship. After the wave interacts with the lower arc-plate breakwater, the wave energy is mainly converted into transmission, reflection and dissipation energies. The wave attenuation performance is clearly weakened for waves with greater heights and longer periods.
基金financially supported by the National Key Research and Development Program of China(Grant No.2016YFC0402603)the National Natural Science Foundation of China(Grant Nos.51779112,51509119,and 51609029)+2 种基金the Project of Tianjin Natural Science Foundation(Grant No.16JCQNJC06900)the Open Project of State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering(Grant No.2014492211)the Fundamental Research Funds for the Central Public Welfare Research Institutes(Grant Nos.TKS170101and TKS170202)
文摘A process-based 3D numerical model for surfzone hydrodynamics and beach evolution was established. Comparisons between the experimental data and model results proved that the model could effectively describe the hydrodynamics, sediment transport feature and sandbar migration process in the surfzone with satisfactory precision. A series of numerical simulations on the wave breaking and shoaling up to a barred beach were carried out based on the model system. Analyzed from the model results, the wave-induced current system in the surfzone consists of two major processes, which are the phase-averaged undertow caused by wave breaking and the net drift caused by both of the nonlinear wave motion and surface roller effect. When storm waves come to the barred beach, the strong offshore undertow along the beach suppresses the onshore net drift, making the initial sandbar migrate to the seaside. Under the condition of calm wave environment, both the undertow and net drift flow to the shoreline at the offshore side of the sandbar, and then push the initial sandbar to the shoreline. The consideration of surface roller has significant impact on the modeling results of the sandbar migration. As the roller transfer rate increases, the sandbar moves onshore especially under the storm wave condition.
文摘目的探讨椎体CT值、腰椎MRI椎体骨质量评分(VBQ评分)对绝经后女性骨量异常的诊断价值。方法回顾性分析2018年1月~2022年8月在广州中医药大学附属番禺区中医院骨科收治的210例绝经后女性患者临床资料,根据双能X线骨密度仪的股骨颈T值,将研究对象分为骨量异常组(骨量减少、骨质疏松,n=166)及骨量正常组(n=44),并测量出各组的CT值以及VBQ评分。采用受试者工作特征曲线(receiver operating curve,ROC)计算曲线下面积(area under the curve,AUC),分析筛查方法的诊断价值,确定诊断截断值,同时计算出不同联合方式筛查方法相应的灵敏度、特异度及约登指数。结果单独运用CT值、VBQ评分作为筛查标准时,AUC分别是0.79、0.777,cut-off值分别是116.75 HU、3.24,其约登指数分别是0.520、0.45,具有一定的诊断价值。CT值联合VBQ评分作为筛查标准时,AUC是0.822,灵敏度是75.9%,特异度为75%,约登指数为0.509;CT值与VBQ评分并联(CT值≤116.75 HU或VBQ评分≥3.24)诊断骨量异常时,其灵敏度为95.26%,特异性为49.16%,约登指数为0.444;串联(CT值≤116.75 HU且VBQ评分≥3.24)诊断骨量异常时,其灵敏度为60.73%,特异性为91.73%,约登指数为0.524,具有较高的诊断价值。结论单独或联合运用CT值、VBQ评分对筛查绝经后女性骨量异常均具有一定的诊断价值,可作为筛查绝经后女性骨量异常的补充方法。
