The present work introduces a mathematical model for ionic fluid that flows under the effect of both pulsating pressure and axial electromagnetic field. The fluid is treated as a Newtonian fluid applying Navier-Stokes...The present work introduces a mathematical model for ionic fluid that flows under the effect of both pulsating pressure and axial electromagnetic field. The fluid is treated as a Newtonian fluid applying Navier-Stokes equation. The fluid is considered as a neutral mixture of positive and negative ions. The effect of axial electric field is investigated to determine velocity profiles. Hydroelectric equation of the flow is deduced under dc and ac external electric field. Hence the effect of applied frequency （0-1 GHz） and amplitude （10-350 V/m） is illustrated. The ultimate goal is to approach the problem of EMF field interaction with blood flow. The applied pressure waveform is represented as such to simulate the systolic-diastolic behavior. Simulation was carried out using Maple software using blood plasma parameters; hence velocity profiles under various conditions are reported.展开更多
目的探究超声血流参数[收缩期峰值血流速度(Vs)、舒张末期血流速度(Vd)、阻力指数(RI)]、D-二聚体手术前后变化及复合模型在创伤骨折患者下肢深静脉血栓形成(DVT)预警中的应用价值。方法选取2021年7月—2023年7月收治的创伤骨折200例,...目的探究超声血流参数[收缩期峰值血流速度(Vs)、舒张末期血流速度(Vd)、阻力指数(RI)]、D-二聚体手术前后变化及复合模型在创伤骨折患者下肢深静脉血栓形成(DVT)预警中的应用价值。方法选取2021年7月—2023年7月收治的创伤骨折200例,根据术后是否发生下肢DVT分为发生组25例与未发生组175例。收集2组基线资料及手术前后Vs、Vd、RI、D-二聚体数据,根据创伤骨折患者术后下肢DVT发生影响因素构建预测复合模型,评估Vs、Vd、RI、D-二聚体手术前后差值联合及复合模型对创伤骨折患者术后下肢DVT发生的预测价值。绘制决策曲线分析(DCA),分析超声血流参数、D-二聚体与复合模型预测创伤骨折患者术后下肢DVT发生的获益情况。结果发生组手术时间长于未发生组,术中使用止血带比例高于未发生组(P<0.01);发生组术后3 d Vs、Vd低于未发生组,RI、D-二聚体高于未发生组(P<0.01);发生组Vs、Vd、RI及D-二聚体手术前后差值均大于未发生组(P<0.01);多因素Logistic回归分析显示,手术时间、术中使用止血带及Vs、Vd、RI、D-二聚体手术前后差值为创伤骨折患者术后下肢DVT发生的独立危险因素(P<0.01);以Vs、Vd、RI、D-二聚体手术前后差值联合预测下肢DVT的曲线下面积(AUC)为0.882(95%CI:0.829,0.923),敏感度、特异度均为0.88。构建下肢DVT预测模型,其AUC为0.920(95%CI:0.873,0.954);DCA显示,复合模型在阈值概率为0.10~0.90时具有更高的临床价值。结论手术时间、术中使用止血带及Vs、Vd、RI、D-二聚体手术前后差值为创伤骨折患者术后下肢DVT发生的独立危险因素;与Vs、Vd、RI、D-二聚体手术前后差值相比,多指标联合建立的复合模型在创伤骨折术后下肢DVT早期预警中应用价值更高。展开更多
<strong>Objective:</strong> To evaluate the effect of physical methods on the prevention of venous thrombosis in patients with peripherally inserted central catheter (PICC). <strong>Methods:</stro...<strong>Objective:</strong> To evaluate the effect of physical methods on the prevention of venous thrombosis in patients with peripherally inserted central catheter (PICC). <strong>Methods:</strong> Randomized controlled trials meeting the inclusion and exclusion criteria were retrieved from the following databases: Cochrane library, Pubmed, EMbase, Web of science, Ovid, CBM, CNKI, Wanfang, VIP, then Review Manage (RevMan) 5.3 software was used for data analysis. <strong>Results:</strong> A total of 24 RCTs including 3496 patients were analyzed in the study. The results of meta-analysis showed that various forms of upper limb movements could effectively decrease the incidence of venous thrombosis in the patients with PICC [<em>RR</em> = 0.23, 95% <em>CI</em> (0.16, 0.33), <em>P</em> < 0.01], upper limb movements could effectively improve the mean blood flow velocity of basilic vein [<em>MD</em> = 1.65, 95% <em>CI</em> (1.19, 2.11), <em>P</em> < 0.01]. <strong>Conclusion:</strong> Upper limb movements can effectively decrease the incidence of phlebothrombosis and improve the mean flow velocity of basilic vein in the patients undergoing PICC. Other forms of physical prevention methods need to be further studied due to insufficient sample size.展开更多
文摘The present work introduces a mathematical model for ionic fluid that flows under the effect of both pulsating pressure and axial electromagnetic field. The fluid is treated as a Newtonian fluid applying Navier-Stokes equation. The fluid is considered as a neutral mixture of positive and negative ions. The effect of axial electric field is investigated to determine velocity profiles. Hydroelectric equation of the flow is deduced under dc and ac external electric field. Hence the effect of applied frequency （0-1 GHz） and amplitude （10-350 V/m） is illustrated. The ultimate goal is to approach the problem of EMF field interaction with blood flow. The applied pressure waveform is represented as such to simulate the systolic-diastolic behavior. Simulation was carried out using Maple software using blood plasma parameters; hence velocity profiles under various conditions are reported.
文摘目的探究超声血流参数[收缩期峰值血流速度(Vs)、舒张末期血流速度(Vd)、阻力指数(RI)]、D-二聚体手术前后变化及复合模型在创伤骨折患者下肢深静脉血栓形成(DVT)预警中的应用价值。方法选取2021年7月—2023年7月收治的创伤骨折200例,根据术后是否发生下肢DVT分为发生组25例与未发生组175例。收集2组基线资料及手术前后Vs、Vd、RI、D-二聚体数据,根据创伤骨折患者术后下肢DVT发生影响因素构建预测复合模型,评估Vs、Vd、RI、D-二聚体手术前后差值联合及复合模型对创伤骨折患者术后下肢DVT发生的预测价值。绘制决策曲线分析(DCA),分析超声血流参数、D-二聚体与复合模型预测创伤骨折患者术后下肢DVT发生的获益情况。结果发生组手术时间长于未发生组,术中使用止血带比例高于未发生组(P<0.01);发生组术后3 d Vs、Vd低于未发生组,RI、D-二聚体高于未发生组(P<0.01);发生组Vs、Vd、RI及D-二聚体手术前后差值均大于未发生组(P<0.01);多因素Logistic回归分析显示,手术时间、术中使用止血带及Vs、Vd、RI、D-二聚体手术前后差值为创伤骨折患者术后下肢DVT发生的独立危险因素(P<0.01);以Vs、Vd、RI、D-二聚体手术前后差值联合预测下肢DVT的曲线下面积(AUC)为0.882(95%CI:0.829,0.923),敏感度、特异度均为0.88。构建下肢DVT预测模型,其AUC为0.920(95%CI:0.873,0.954);DCA显示,复合模型在阈值概率为0.10~0.90时具有更高的临床价值。结论手术时间、术中使用止血带及Vs、Vd、RI、D-二聚体手术前后差值为创伤骨折患者术后下肢DVT发生的独立危险因素;与Vs、Vd、RI、D-二聚体手术前后差值相比,多指标联合建立的复合模型在创伤骨折术后下肢DVT早期预警中应用价值更高。
文摘<strong>Objective:</strong> To evaluate the effect of physical methods on the prevention of venous thrombosis in patients with peripherally inserted central catheter (PICC). <strong>Methods:</strong> Randomized controlled trials meeting the inclusion and exclusion criteria were retrieved from the following databases: Cochrane library, Pubmed, EMbase, Web of science, Ovid, CBM, CNKI, Wanfang, VIP, then Review Manage (RevMan) 5.3 software was used for data analysis. <strong>Results:</strong> A total of 24 RCTs including 3496 patients were analyzed in the study. The results of meta-analysis showed that various forms of upper limb movements could effectively decrease the incidence of venous thrombosis in the patients with PICC [<em>RR</em> = 0.23, 95% <em>CI</em> (0.16, 0.33), <em>P</em> < 0.01], upper limb movements could effectively improve the mean blood flow velocity of basilic vein [<em>MD</em> = 1.65, 95% <em>CI</em> (1.19, 2.11), <em>P</em> < 0.01]. <strong>Conclusion:</strong> Upper limb movements can effectively decrease the incidence of phlebothrombosis and improve the mean flow velocity of basilic vein in the patients undergoing PICC. Other forms of physical prevention methods need to be further studied due to insufficient sample size.
