Dynamic modeling of the outlet of a pulsatile pump incorporating a flow-dependent resistance

Outlet tube models incorporating a linearly flow-dependent resistance are widely used in pulsatile and rotary pump studies. The resistance is made up of a flow-proportional term and a constant term. Previous studies often focused on the steady state properties of the model. In this paper, a dynamic modeling procedure was presented. Model parameters were estimated by an unscented Kalman filter (UKF). The subspace model identification (SMI) algorithm was proposed to initialize the UKF. Model order and structure were also validated by SMI. A mock circulatory loop driven by a pneumatic pulsatile pump was developed to produce pulsatile pressure and flow. Hydraulic parameters of the outlet tube were adjusted manually by a clamp. Seven groups of steady state experiments were carried out to calibrate the flow-dependent resistance as reference values. Dynamic estimation results showed that the inertance estimates are insensitive to model structures. If the constant term was ignored, estimation errors for the flow-proportional term were limited within 16% of the reference values. Compared with the constant resistance, a time-varying one improves model accuracy in terms of root mean square error. The maximum improvement is up to 35%. However, including the constant term in the time-varying resistance will lead to serious estimation errors.     

Hierarchical polymer coating for optimizing the antifouling and bactericidal efficacies

The bacteria-repellent and bactericidal functionalities in a single system are generally need to be carefully optimized in order to obtain the highest antibacterial performance. In this study, the controlled SI-PIMP strategy was developed for creating hierarchical polymer brushes possessing the bacteria-repellent and bactericidal functionalities. To obtain a bactericidal surface with minimal interference to its nonfouling property, optimization studies were conducted by facilely tailoring the surface density of the quaternary ammonium compound moieties through control over the monomer concentration. An optimal hierarchical polymer coating showed potent protein and bacteria repellence as well as certain bactericidal property. The longlasting antibacterial performance was also achieved due to the good balance between the dual functionalities. The tenability of the hierarchical polymer coating is applicable to surface chemistries for biosensors, molecular imaging, and biomedical applications.     

利尿剂在抗心衰治疗中的地位

利尿药在治疗心力衰竭具有显著的疗效,是临床治疗心力衰竭的基础药物。目前临床上关于利尿药在抗心衰治疗中的制剂类型选择、剂量控制、给药方法等合理用药方法存在许多问题。本研究对近年来利尿剂在抗心衰治疗中的作用机制、剂型选择、剂量控制以及药物不良反应等研究状况进行综述,以期为利尿药在抗心衰治疗中更加安全有效提供参考。     

甘露醇对脑出血后脑水肿的影响

目的探讨甘露醇对脑出血后脑水肿的影响。方法对入选的51例脑出血患者进行回顾性分析,将其分为发病24小时内入院应用甘露醇组(35例)和24小时后入院应用甘露醇组(16例);48小时和2周后复查脑CT,通过对比脑水肿的变化,分析脑出血发病24小时内应用甘露醇对脑水肿的影响。结果发病24小时内使用甘露醇组48小时出现脑水肿加重者5例(14.3%),2周后21例(60.0%);24小时后使用甘露醇组48小时出现脑水肿加重者1例(6.3%),2周后3例(18.8%)。两者48小时CT比较差异无显著意义(P>0.05),2周后CT比较差异有非常显著意义(P<0.01);2周后疗效比较差异有显著意义(P<0.05)。结论脑出血患者发病24小时内不适当应用甘露醇可使脑水肿和病情加重。因此,脑出血患者早期使用甘露醇应慎重。     

围绝经期女性患者住院期间焦虑抑郁情绪调查研究

目的探讨围绝经期女性患者焦虑抑郁情绪的检出率和影响因素。方法采用自编问卷、抑郁自评量表（SDS）和焦虑自评量表（SAS）对2011年12月-2012年12月在浙江省金华市中心医院住院治疗的200例围绝经期女性患者进行测评,运用SPSS 18.0统计软件进行描述性统计和二分类Logistic回归分析,探讨围绝经期女性患者焦虑抑郁情绪检出率和影响因素,旨在为采取针对性的干预措施提供参考依据。结果 200例围绝经期女性患者中焦虑情绪检出率为20.50%（41/200）,抑郁情绪检出率为22.50%（45/200）。多因素Logistic回归分析显示,伴侣健康状况好是围绝经期女性患者住院期间焦虑情绪的保护因素（P〈0.05）,经济状况好是围绝经期女性患者住院期间抑郁情绪的保护因素（P〈0.05）,文化程度高和婚姻自我感觉好是围绝经期女性患者住院期间焦虑抑郁情绪的保护因素（P〈0.05）,患者年龄大和所患疾病为恶性是围绝经期女性患者住院期间焦虑、抑郁情绪的危险因素（P〈0.05）。结论围绝经期女性患者抑郁焦虑情绪检出率较高,其发生影响因素众多。在对患者进行干预的过程中,应对高危人群进行重点干预,减少患者焦虑抑郁情绪的出现。     

一种非血液接触式气动心室辅助装置的设计及体外测试

介绍了一种非血液接触式气动心室辅助装置．它包含一个双腔室心脏辅助杯．一个可与电脑连接的心脏辅助控制器及真空泵、空压机等装置。将其接人模拟人体循环系统进行测试,得到与人体正常血压相接近的输出。     

耳石复位法治疗良性阵发性位置性眩晕疗效观察

目的观察耳石复位法治疗良性阵发性位置性眩晕(BPPV)的疗效,并探讨其与颈性眩晕的鉴别要点。方法选择100例BPPV患者,其中后上半规管性患者60例采用Epley复位法治疗,复位法水平半规管性患者40例采用barbecue翻滚法治疗,观察治疗效果。结果治疗2周后复查,痊愈95例,改善3例,无效2例。近期治愈率为95%,有效率为98%。对于改善及无效的患者行颈椎X线检查,表现为不同程度的颈椎退行性改变及颈椎不稳。结论Epley法和barbecue翻滚法是一种快捷、简单、经济有效的治疗BPPV的方法。但对于中老年人,有颈部外伤史、长期伏案工作者、尤其伴有颈部疼痛和耳部症状者,应与颈性眩晕相鉴别。