Recent damages to the box-like structures caused by wave slamming have made it necessary to study the impact problems of this kind of structure. This paper showed findings from numerical simulations of the rigid/elast...Recent damages to the box-like structures caused by wave slamming have made it necessary to study the impact problems of this kind of structure. This paper showed findings from numerical simulations of the rigid/elastic structures, aiming to gain insights into the characteristics of the problem. The results of the rigid cases showed the significance of air compressibility during the impact process, while the slamming phenomena became quite different without the effect. In the elastic cases, the trapped air made the structure vibrate at frequencies much smaller than its eigenfrequencies. Besides, the structural deformation made it easy for the trapped air to escape outwards, which weakened the air cushioning effect, especially at high impact velocities. The above analysis gives the results when the structural symmetry axis was vertical to the water(vertical impacts). In addition, the results were given when the axis was oblique to the water(oblique impacts). Compared with the vertical cases, the impact phenomena and structural response showed asymmetry. This work used the computational fluid dynamics(CFD) method to describe fluid motion and the finite element method(FEM) for the deformable structure. A two-way coupling approach was used to deal with the fluid-structure interaction in the elastic cases.展开更多
An analytical model based on statistical energy analysis (SEA) is developed for the sound pressurelevels inside a box-like structure due to wide-band random excitation applied at a prescribed point on thestructure.So...An analytical model based on statistical energy analysis (SEA) is developed for the sound pressurelevels inside a box-like structure due to wide-band random excitation applied at a prescribed point on thestructure.Some conditions that the sound field inside cavity must adapts to SEA assumes are given. Thesound responses inside the box structure for four different input mobilities are predicted using the SEA modeland compared with expermental results On the basis of these results,possible ways of reducing the noise in-side the box structure are suggested.展开更多
目的探究血清叉头盒蛋白M1(forkhead box protein M1,FOXM1)和胰岛素样生长因子2(insulin-like growth factor 2,IGF2)表达对老年心力衰竭合并肺炎患者预后的预测价值。方法将邯郸市中心医院2021年3月~2022年6月收治的126例老年心力衰...目的探究血清叉头盒蛋白M1(forkhead box protein M1,FOXM1)和胰岛素样生长因子2(insulin-like growth factor 2,IGF2)表达对老年心力衰竭合并肺炎患者预后的预测价值。方法将邯郸市中心医院2021年3月~2022年6月收治的126例老年心力衰竭并发肺炎患者设为病例组,并根据随访情况将122例患者分为预后不良组(n=33)和预后良好组(n=89),另选取该院同期126例健康体检者为对照组。检测两组(病例组和对照组)血清FOXM1和IGF2水平,检测病例组用力肺活量(forced vital capacity,FVC)和第一秒用力呼容积(forced expiratory volume in one second,FEV1)。采用Spearman分析法分析老年心力衰竭并发肺炎患者血清FOXM1和IGF2水平与心功能分级的相关性;受试者工作特征(receiver operating characteristic,ROC)曲线分析血清FOXM1和IGF2水平对老年心力衰竭并发肺炎患者预后的预测价值。结果与对照组比较,病例组血清FOXM1(2.39±0.55 vs 1.06±0.21)和IGF2(71.33±7.96pg/ml vs 47.82±5.14pg/ml)水平明显较高,差异有统计学意义(t=25.358,27.581,均P<0.05);与预后良好组比较,预后不良组血清FOXM1(3.87±1.06 vs 1.95±0.51)和IGF2水平(85.88±9.54pg/ml vs 69.14±8.73pg/ml)明显较高,差异具有统计学意义(t=13.453,9.174,均P<0.05);预后良好组和预后不良组心功能分级比较差异有统计学意义(χ^(2)=7.120,P<0.05),且与预后不良组比较,预后良好组FEV1(1.24±0.32L vs 1.08±0.25L)和FEV1/FVC(55.46%±5.77%vs 52.30%±5.38%)明显较高,差异有统计学意义(t=2.592,2.735,均P<0.05);老年心力衰竭并发肺炎患者血清FOXM1水平和IGF2水平与心功能分级呈显著正相关(r=0.496,0.517,均P<0.05)。ROC曲线结果显示,血清FOXM1单独预测老年心力衰竭并发肺炎患者预后的曲线下面积(area under the curve,AUC)为0.854(95CI%:0.779~0.912),其敏感度、特异度分别为75.76%,86.52%,最佳截断值为2.75;IGF2单独预测老年心力衰竭并发肺炎患者预后的AUC为0.874(95CI%:0.802~0.927),其敏感度、特异度分别为72.73%,85.39%,最佳截断值为78.30 pg/ml;二者联合预测老年心力衰竭并发肺炎患者预后的AUC显著大于血清FOXM1和IGF2单独诊断的AUC(Z=2.413,2.737,P=0.006,0.016)。结论血清FOXM1和IGF2水平在老年心力衰竭并发肺炎患者中升高,且二者联合检测对患者预后具有较高的预测价值。展开更多
目的:探讨跑台运动训练对脊髓损伤(SCI)后大鼠肺损伤及HMGB1/TLR4/NF-κB信号通路表达的影响。方法:选取54只SD雌性大鼠,随机分成3组,包括假手术组、SCI制动组、SCI运动组。SCI运动组及SCI制动组分别于术后第3天开始跑台运动训练或制动...目的:探讨跑台运动训练对脊髓损伤(SCI)后大鼠肺损伤及HMGB1/TLR4/NF-κB信号通路表达的影响。方法:选取54只SD雌性大鼠,随机分成3组,包括假手术组、SCI制动组、SCI运动组。SCI运动组及SCI制动组分别于术后第3天开始跑台运动训练或制动干预,BBB评分评定大鼠脊髓损伤后后肢运动功能。分别在运动或制动后第3天、第7天取肺组织,HE染色检测大鼠肺组织病理结构变化;免疫组化检测肺组织HMGB1蛋白表达情况;qRT-PCR检测HMGB1、TLR4、NF-κB、IL-1β、IL-6、TNF-α m RNA表达情况;Western Blot检测HMGB1、TLR4、NF-κB蛋白表达情况。结果:BBB评分结果显示,与假手术组比较,SCI制动组、SCI运动组BBB评分均显著下降(P<0.05);SCI运动组与SCI制动组评分结果比较无显著性差异(P>0.05)。HE染色结果显示,SCI制动组及SCI运动组第3天、第7天肺组织中均出现水肿、出血、炎性细胞浸润,相较于SCI制动组,SCI运动组肺损伤评分显著降低(P<0.05)。qRT-PCR、免疫组化、Western Blot结果均显示,与假手术比较,SCI制动组、SCI运动组第3天、第7天肺组织中HMGB1、TLR4、NF-κB、IL-1β、IL-6、TNF-α等因子的表达均显著上调(P<0.05),且SCI运动组较SCI制动组显著降低(P<0.05)。结论:跑台运动训练可改善脊髓损伤后大鼠肺损伤,其机制可能与调节HMGB1/TLR4/NF-κB信号通路,抑制肺组织炎症反应相关。展开更多
基金financially supported by the National Key Research and Development Program of China (Grant No. 2019YFC1407700)。
文摘Recent damages to the box-like structures caused by wave slamming have made it necessary to study the impact problems of this kind of structure. This paper showed findings from numerical simulations of the rigid/elastic structures, aiming to gain insights into the characteristics of the problem. The results of the rigid cases showed the significance of air compressibility during the impact process, while the slamming phenomena became quite different without the effect. In the elastic cases, the trapped air made the structure vibrate at frequencies much smaller than its eigenfrequencies. Besides, the structural deformation made it easy for the trapped air to escape outwards, which weakened the air cushioning effect, especially at high impact velocities. The above analysis gives the results when the structural symmetry axis was vertical to the water(vertical impacts). In addition, the results were given when the axis was oblique to the water(oblique impacts). Compared with the vertical cases, the impact phenomena and structural response showed asymmetry. This work used the computational fluid dynamics(CFD) method to describe fluid motion and the finite element method(FEM) for the deformable structure. A two-way coupling approach was used to deal with the fluid-structure interaction in the elastic cases.
文摘An analytical model based on statistical energy analysis (SEA) is developed for the sound pressurelevels inside a box-like structure due to wide-band random excitation applied at a prescribed point on thestructure.Some conditions that the sound field inside cavity must adapts to SEA assumes are given. Thesound responses inside the box structure for four different input mobilities are predicted using the SEA modeland compared with expermental results On the basis of these results,possible ways of reducing the noise in-side the box structure are suggested.
文摘目的探究血清叉头盒蛋白M1(forkhead box protein M1,FOXM1)和胰岛素样生长因子2(insulin-like growth factor 2,IGF2)表达对老年心力衰竭合并肺炎患者预后的预测价值。方法将邯郸市中心医院2021年3月~2022年6月收治的126例老年心力衰竭并发肺炎患者设为病例组,并根据随访情况将122例患者分为预后不良组(n=33)和预后良好组(n=89),另选取该院同期126例健康体检者为对照组。检测两组(病例组和对照组)血清FOXM1和IGF2水平,检测病例组用力肺活量(forced vital capacity,FVC)和第一秒用力呼容积(forced expiratory volume in one second,FEV1)。采用Spearman分析法分析老年心力衰竭并发肺炎患者血清FOXM1和IGF2水平与心功能分级的相关性;受试者工作特征(receiver operating characteristic,ROC)曲线分析血清FOXM1和IGF2水平对老年心力衰竭并发肺炎患者预后的预测价值。结果与对照组比较,病例组血清FOXM1(2.39±0.55 vs 1.06±0.21)和IGF2(71.33±7.96pg/ml vs 47.82±5.14pg/ml)水平明显较高,差异有统计学意义(t=25.358,27.581,均P<0.05);与预后良好组比较,预后不良组血清FOXM1(3.87±1.06 vs 1.95±0.51)和IGF2水平(85.88±9.54pg/ml vs 69.14±8.73pg/ml)明显较高,差异具有统计学意义(t=13.453,9.174,均P<0.05);预后良好组和预后不良组心功能分级比较差异有统计学意义(χ^(2)=7.120,P<0.05),且与预后不良组比较,预后良好组FEV1(1.24±0.32L vs 1.08±0.25L)和FEV1/FVC(55.46%±5.77%vs 52.30%±5.38%)明显较高,差异有统计学意义(t=2.592,2.735,均P<0.05);老年心力衰竭并发肺炎患者血清FOXM1水平和IGF2水平与心功能分级呈显著正相关(r=0.496,0.517,均P<0.05)。ROC曲线结果显示,血清FOXM1单独预测老年心力衰竭并发肺炎患者预后的曲线下面积(area under the curve,AUC)为0.854(95CI%:0.779~0.912),其敏感度、特异度分别为75.76%,86.52%,最佳截断值为2.75;IGF2单独预测老年心力衰竭并发肺炎患者预后的AUC为0.874(95CI%:0.802~0.927),其敏感度、特异度分别为72.73%,85.39%,最佳截断值为78.30 pg/ml;二者联合预测老年心力衰竭并发肺炎患者预后的AUC显著大于血清FOXM1和IGF2单独诊断的AUC(Z=2.413,2.737,P=0.006,0.016)。结论血清FOXM1和IGF2水平在老年心力衰竭并发肺炎患者中升高,且二者联合检测对患者预后具有较高的预测价值。
文摘目的:探讨跑台运动训练对脊髓损伤(SCI)后大鼠肺损伤及HMGB1/TLR4/NF-κB信号通路表达的影响。方法:选取54只SD雌性大鼠,随机分成3组,包括假手术组、SCI制动组、SCI运动组。SCI运动组及SCI制动组分别于术后第3天开始跑台运动训练或制动干预,BBB评分评定大鼠脊髓损伤后后肢运动功能。分别在运动或制动后第3天、第7天取肺组织,HE染色检测大鼠肺组织病理结构变化;免疫组化检测肺组织HMGB1蛋白表达情况;qRT-PCR检测HMGB1、TLR4、NF-κB、IL-1β、IL-6、TNF-α m RNA表达情况;Western Blot检测HMGB1、TLR4、NF-κB蛋白表达情况。结果:BBB评分结果显示,与假手术组比较,SCI制动组、SCI运动组BBB评分均显著下降(P<0.05);SCI运动组与SCI制动组评分结果比较无显著性差异(P>0.05)。HE染色结果显示,SCI制动组及SCI运动组第3天、第7天肺组织中均出现水肿、出血、炎性细胞浸润,相较于SCI制动组,SCI运动组肺损伤评分显著降低(P<0.05)。qRT-PCR、免疫组化、Western Blot结果均显示,与假手术比较,SCI制动组、SCI运动组第3天、第7天肺组织中HMGB1、TLR4、NF-κB、IL-1β、IL-6、TNF-α等因子的表达均显著上调(P<0.05),且SCI运动组较SCI制动组显著降低(P<0.05)。结论:跑台运动训练可改善脊髓损伤后大鼠肺损伤,其机制可能与调节HMGB1/TLR4/NF-κB信号通路,抑制肺组织炎症反应相关。
